Science.gov

Sample records for conditional mutualism limits

  1. A strong conditional mutualism limits and enhances seed dispersal and germination of a tropical palm

    USGS Publications Warehouse

    Klinger, R.; Rejmanek, M.

    2010-01-01

    Seed predation and seed dispersal can have strong effects on early life history stages of plants. These processes have often been studied as individual effects, but the degree to which their relative importance co-varies with seed predator abundance and how this influences seed germination rates is poorly understood. Therefore, we used a combination of observations and field experiments to determine the degree to which germination rates of the palm Astrocaryum mexicanum varied with abundance of a small mammal seed predator/disperser, Heteromysdesmarestianus, in a lowland tropical forest. Patterns of abundance of the two species were strongly related; density of H. desmarestianus was low in sites with low density of A. mexicanum and vice versa. Rates of predation and dispersal of A. mexicanum seeds depended on abundance of H. desmarestianus; sites with high densities of H. desmarestianus had the highest rates of seed predation and lowest rates of seed germination, but a greater total number of seeds were dispersed and there was greater density of seedlings, saplings, and adults of A. mexicanum in these sites. When abundance of H. desmarestianus was experimentally reduced, rates of seed predation decreased, but so did dispersal of A. mexicanum seeds. Critically, rates of germination of dispersed seeds were 5 times greater than undispersed seeds. The results suggest that the relationship between A. mexicanum and H. desmarestianus is a conditional mutualism that results in a strong local effect on the abundance of each species. However, the magnitude and direction of these effects are determined by the relative strength of opposing, but related, mechanisms. A. mexicanum nuts provide H. desmarestianus with a critical food resource, and while seed predation on A. mexicanum nuts by H. desmarestianus is very intense, A. mexicanum ultimately benefits because of the relatively high germination rates of its seeds that are dispersed by H. desmarestianus. ?? The Author(s) 2010.

  2. Rényi generalizations of the conditional quantum mutual information

    NASA Astrophysics Data System (ADS)

    Berta, Mario; Seshadreesan, Kaushik P.; Wilde, Mark M.

    2015-02-01

    The conditional quantum mutual information I(A; B|C) of a tripartite state ?ABC is an information quantity which lies at the center of many problems in quantum information theory. Three of its main properties are that it is non-negative for any tripartite state, that it decreases under local operations applied to systems A and B, and that it obeys the duality relation I(A; B|C) = I(A; B|D) for a four-party pure state on systems ABCD. The conditional mutual information also underlies the squashed entanglement, an entanglement measure that satisfies all of the axioms desired for an entanglement measure. As such, it has been an open question to find Rényi generalizations of the conditional mutual information, that would allow for a deeper understanding of the original quantity and find applications beyond the traditional memoryless setting of quantum information theory. The present paper addresses this question, by defining different ?-Rényi generalizations I?(A; B|C) of the conditional mutual information, some of which we can prove converge to the conditional mutual information in the limit ? ? 1. Furthermore, we prove that many of these generalizations satisfy non-negativity, duality, and monotonicity with respect to local operations on one of the systems A or B (with it being left as an open question to prove that monotonicity holds with respect to local operations on both systems). The quantities defined here should find applications in quantum information theory and perhaps even in other areas of physics, but we leave this for future work. We also state a conjecture regarding the monotonicity of the Rényi conditional mutual informations defined here with respect to the Rényi parameter ?. We prove that this conjecture is true in some special cases and when ? is in a neighborhood of one.

  3. Rényi generalizations of the conditional quantum mutual information

    SciTech Connect

    Berta, Mario; Seshadreesan, Kaushik P.; Wilde, Mark M.

    2015-02-15

    The conditional quantum mutual information I(A; B|C) of a tripartite state ?{sub ABC} is an information quantity which lies at the center of many problems in quantum information theory. Three of its main properties are that it is non-negative for any tripartite state, that it decreases under local operations applied to systems A and B, and that it obeys the duality relation I(A; B|C) = I(A; B|D) for a four-party pure state on systems ABCD. The conditional mutual information also underlies the squashed entanglement, an entanglement measure that satisfies all of the axioms desired for an entanglement measure. As such, it has been an open question to find Rényi generalizations of the conditional mutual information, that would allow for a deeper understanding of the original quantity and find applications beyond the traditional memoryless setting of quantum information theory. The present paper addresses this question, by defining different ?-Rényi generalizations I{sub ?}(A; B|C) of the conditional mutual information, some of which we can prove converge to the conditional mutual information in the limit ? ? 1. Furthermore, we prove that many of these generalizations satisfy non-negativity, duality, and monotonicity with respect to local operations on one of the systems A or B (with it being left as an open question to prove that monotonicity holds with respect to local operations on both systems). The quantities defined here should find applications in quantum information theory and perhaps even in other areas of physics, but we leave this for future work. We also state a conjecture regarding the monotonicity of the Rényi conditional mutual informations defined here with respect to the Rényi parameter ?. We prove that this conjecture is true in some special cases and when ? is in a neighborhood of one.

  4. Are linear prebuckling paths and linear stability problems mutually conditional?

    NASA Astrophysics Data System (ADS)

    Steinboeck, Andreas; Mang, Herbert A.

    2008-08-01

    Stability problems are termed linear if the tangent stiffness used for determining loss of stability has a specific, simple form. The term “linear prebuckling paths” refers to the shape of the load displacement diagrams before loss of stability. In this note, it will be shown that these two terms are not mutually conditional.

  5. Quantum Conditional Mutual Information and Approximate Markov Chains

    NASA Astrophysics Data System (ADS)

    Fawzi, Omar; Renner, Renato

    2015-12-01

    A state on a tripartite quantum system forms a Markov chain if it can be reconstructed from its marginal on by a quantum operation from B to . We show that the quantum conditional mutual information I( A : C| B) of an arbitrary state is an upper bound on its distance to the closest reconstructed state. It thus quantifies how well the Markov chain property is approximated.

  6. 26 CFR 1.809-8 - Limitation on deductions for certain mutualization distributions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Gain and Loss from Operations § 1.809-8... investment income. Section 809(g)(1) limits the deduction under section 809(d)(11) for certain mutualization... investment income for such year. (b) Deduction not to reduce tax below that imposed by 1957 law. Section...

  7. Oklahoma Retailers' Perspectives on Mutual Benefit Exchange to Limit Point-of-Sale Tobacco Advertisements.

    PubMed

    Chan, Andie; Douglas, Malinda Reddish; Ling, Pamela M

    2015-09-01

    Businesses changing their practices in ways that support tobacco control efforts recently have gained interest, as demonstrated by CVS Health's voluntary policy to end tobacco sales. Point-of-sale (POS) advertisements are associated with youth smoking initiation, increased tobacco consumption, and reduced quit attempts among smokers. There is interest in encouraging retailers to limit tobacco POS advertisements voluntarily. This qualitative exploratory study describes Oklahoma tobacco retailers' perspectives on a mutual benefit exchange approach, and preferred message and messenger qualities that would entice them to take voluntary action to limit tobacco POS advertisements. This study found that mutual benefit exchange could be a viable option along with education and law as strategies to create behavior change among tobacco retailers. Many retailers stated that they would be willing to remove noncontractual POS advertisements for a 6-month commitment period when presented with mutual exchange benefit, tailored message, and appropriate messenger. Mutual benefit exchange, as a behavior change strategy to encourage voluntary removal of POS tobacco advertisements, was acceptable to retailers, could enhance local tobacco control in states with preemption, and may contribute to setting the foundation for broader legislative efforts. PMID:25767197

  8. An Additive and Operational Entanglement Measure: Conditional Entanglement of Mutual Information

    NASA Astrophysics Data System (ADS)

    Yang, Dong; Horodecki, Micha?; Wang, Z. D.

    2008-10-01

    Based on the monogamy of entanglement, we develop the technique of quantum conditioning to build an additive entanglement measure: the conditional entanglement of mutual information. Its operational meaning is elaborated to be the minimal net “flow of qubits” in the process of partial state merging. The result and conclusion can also be generalized to multipartite entanglement cases.

  9. Information-Theoretic Limits on Broadband Multi-Antenna Systems in the Presence of Mutual Coupling

    NASA Astrophysics Data System (ADS)

    Taluja, Pawandeep Singh

    2011-12-01

    Multiple-input, multiple-output (MIMO) systems have received considerable attention over the last decade due to their ability to provide high throughputs and mitigate multipath fading effects. While most of these benefits are obtained for ideal arrays with large separation between the antennas, practical devices are often constrained in physical dimensions. With smaller inter-element spacings, signal correlation and mutual coupling between the antennas start to degrade the system performance, thereby limiting the deployment of a large number of antennas. Various studies have proposed transceiver designs based on optimal matching networks to compensate for this loss. However, such networks are considered impractical due to their multiport structure and sensitivity to the RF bandwidth of the system. In this dissertation, we investigate two aspects of compact transceiver design. First, we consider simpler architectures that exploit coupling between the antennas, and second, we establish information-theoretic limits of broadband communication systems with closely-spaced antennas. We begin with a receiver model of a diversity antenna selection system and propose novel strategies that make use of inactive elements by virtue of mutual coupling. We then examine the limits on the matching efficiency of a single antenna system using broadband matching theory. Next, we present an extension to this theory for coupled MIMO systems to elucidate the impact of coupling on the RF bandwidth of the system, and derive optimal transceiver designs. Lastly, we summarize the main findings of this dissertation and suggest open problems for future work.

  10. Conditional mutual inclusive information enables accurate quantification of associations in gene regulatory networks

    PubMed Central

    Zhang, Xiujun; Zhao, Juan; Hao, Jin-Kao; Zhao, Xing-Ming; Chen, Luonan

    2015-01-01

    Mutual information (MI), a quantity describing the nonlinear dependence between two random variables, has been widely used to construct gene regulatory networks (GRNs). Despite its good performance, MI cannot separate the direct regulations from indirect ones among genes. Although the conditional mutual information (CMI) is able to identify the direct regulations, it generally underestimates the regulation strength, i.e. it may result in false negatives when inferring gene regulations. In this work, to overcome the problems, we propose a novel concept, namely conditional mutual inclusive information (CMI2), to describe the regulations between genes. Furthermore, with CMI2, we develop a new approach, namely CMI2NI (CMI2-based network inference), for reverse-engineering GRNs. In CMI2NI, CMI2 is used to quantify the mutual information between two genes given a third one through calculating the Kullback–Leibler divergence between the postulated distributions of including and excluding the edge between the two genes. The benchmark results on the GRNs from DREAM challenge as well as the SOS DNA repair network in Escherichia coli demonstrate the superior performance of CMI2NI. Specifically, even for gene expression data with small sample size, CMI2NI can not only infer the correct topology of the regulation networks but also accurately quantify the regulation strength between genes. As a case study, CMI2NI was also used to reconstruct cancer-specific GRNs using gene expression data from The Cancer Genome Atlas (TCGA). CMI2NI is freely accessible at http://www.comp-sysbio.org/cmi2ni. PMID:25539927

  11. Anoxic Conditions Promote Species-Specific Mutualism between Gut Microbes In Silico

    PubMed Central

    Heinken, Almut

    2015-01-01

    The human gut is inhabited by thousands of microbial species, most of which are still uncharacterized. Gut microbes have adapted to each other's presence as well as to the host and engage in complex cross feeding. Constraint-based modeling has been successfully applied to predicting microbe-microbe interactions, such as commensalism, mutualism, and competition. Here, we apply a constraint-based approach to model pairwise interactions between 11 representative gut microbes. Microbe-microbe interactions were computationally modeled in conjunction with human small intestinal enterocytes, and the microbe pairs were subjected to three diets with various levels of carbohydrate, fat, and protein in normoxic or anoxic environments. Each microbe engaged in species-specific commensal, parasitic, mutualistic, or competitive interactions. For instance, Streptococcus thermophilus efficiently outcompeted microbes with which it was paired, in agreement with the domination of streptococci in the small intestinal microbiota. Under anoxic conditions, the probiotic organism Lactobacillus plantarum displayed mutualistic behavior toward six other species, which, surprisingly, were almost entirely abolished under normoxic conditions. This finding suggests that the anoxic conditions in the large intestine drive mutualistic cross feeding, leading to the evolvement of an ecosystem more complex than that of the small intestinal microbiota. Moreover, we predict that the presence of the small intestinal enterocyte induces competition over host-derived nutrients. The presented framework can readily be expanded to a larger gut microbial community. This modeling approach will be of great value for subsequent studies aiming to predict conditions favoring desirable microbes or suppressing pathogens. PMID:25841013

  12. The Curious Case of the Camelthorn: Competition, Coexistence, and Nest-Site Limitation in a Multispecies Mutualism.

    PubMed

    Campbell, Heather; Fellowes, Mark D E; Cook, James M

    2015-12-01

    Myrmecophyte plants house ants within domatia in exchange for protection against herbivores. Ant-myrmecophyte mutualisms exhibit two general patterns due to competition between ants for plant occupancy: (i) domatia nest sites are a limiting resource and (ii) each individual plant hosts one ant species at a time. However, individual camelthorn trees (Vachellia erioloba) typically host two to four ant species simultaneously, often coexisting in adjacent domatia on the same branch. Such fine-grain spatial coexistence brings into question the conventional wisdom on ant-myrmecophyte mutualisms. Camelthorn ants appear not to be nest-site limited, despite low abundance of suitable domatia, and have random distributions of nest sites within and across trees. These patterns suggest a lack of competition between ants for domatia and contrast strongly with other ant-myrmecophyte systems. Comparison of this unusual case with others suggests that spatial scale is crucial to coexistence or competitive exclusion involving multiple ant species. Furthermore, coexistence may be facilitated when co-occurring ant species diverge strongly on at least one niche axis. Our conclusions provide recommendations for future ant-myrmecophyte research, particularly in utilizing multispecies systems to further our understanding of mutualism biology. PMID:26655993

  13. Feasibility and benefits of methanogenesis under oxygen-limited conditions

    SciTech Connect

    Zitomer, D.H.; Shrout, J.D.

    1998-12-31

    Methanogenic and aerobic (or microaerophilic) biological processes are often considered mutually exclusive and separated as biological wastewater treatment options. However, under oxygen-limited conditions, both aerobic respiration and methanogenesis can be practically accomplished by a single mixed culture. This paper describes sustained batch culture, oxygen-limited methanogenic serum bottle and bench-scale systems. Serum bottle cultures exhibited methanogenic activity similar to or greater than that of a strictly anaerobic culture maintained in parallel. The COD removal efficiencies of anaerobic, oxygen-limited, and aerobic bench-scale reactors receiving 30,000 mg/l of sucrose were all greater than 93%, a system receiving 1 g O{sub 2}/L{sub R}-day achieved a lower final effluent COD than the strictly anaerobic reactor. After a shock-load of sucrose, the pH recovered in low-aeration batch reactors in 28--34 days, whereas anaerobic pH did not recover after 52 days of observation. In the future, methanogenesis under limited-aeration may be employed as an energy efficient treatment option to achieve low final COD concentrations, minimal biosolids generation, and mineralization of a broad range of specific organic chemicals.

  14. Limited Conditions of Operations Tracking Program

    Energy Science and Technology Software Center (ESTSC)

    1999-12-17

    The Lco tracking program is a computer based solution for tracking time limited action items for Limited Conditions of Operation (LCO) for nuclear and industrial processes. This use is not limited to any process except those not requiring specific action steps and times. The visual and audible assistance the LCO Tracking Program provides significantly reduces the chance of missing crucial actions required for safe operation of any facility in time of limited operations. The LCOmore » Tracking Program maintains all applicable action steps and times for each limited condition for the facility in its data base. The LCO Tracking Program is used to enter that condition by number, and the data base provides the applicble action steps and starts tracking their times based on the time the LCO was entered. The LCO display graphically displays, by colored bar charts, the time expired/time remaining of each specific action item. At 60% time expired, the bar chart turns yellow to caution personnel and then turns red at 90% time expired. Then an audible alarm is sounded at 95% as a warning, to finish or accomplish the required actions to satisfy the requirements. These warning and alarm limits are modifiable by the user and can be set at different values for each action. The display file is dynamic in function, checking every minute, and responds in real time to changes to the LCO Tracking Form file, providing the visual and audible warnings as to the status of the action steps chosen for display. The LCO Tracking Program efficiently tracks action times in minutes or days, up to 2 years. All current LCO''s are easily documentated using the LCO Tracking Form file with ease of printing and disposition. The Lco Tracking Program is designed as a user friendly program with navigational buttons to simplify use.« less

  15. CN: a consensus algorithm for inferring gene regulatory networks using the SORDER algorithm and conditional mutual information test.

    PubMed

    Aghdam, Rosa; Ganjali, Mojtaba; Zhang, Xiujun; Eslahchi, Changiz

    2015-03-01

    Inferring Gene Regulatory Networks (GRNs) from gene expression data is a major challenge in systems biology. The Path Consistency (PC) algorithm is one of the popular methods in this field. However, as an order dependent algorithm, PC algorithm is not robust because it achieves different network topologies if gene orders are permuted. In addition, the performance of this algorithm depends on the threshold value used for independence tests. Consequently, selecting suitable sequential ordering of nodes and an appropriate threshold value for the inputs of PC algorithm are challenges to infer a good GRN. In this work, we propose a heuristic algorithm, namely SORDER, to find a suitable sequential ordering of nodes. Based on the SORDER algorithm and a suitable interval threshold for Conditional Mutual Information (CMI) tests, a network inference method, namely the Consensus Network (CN), has been developed. In the proposed method, for each edge of the complete graph, a weighted value is defined. This value is considered as the reliability value of dependency between two nodes. The final inferred network, obtained using the CN algorithm, contains edges with a reliability value of dependency of more than a defined threshold. The effectiveness of this method is benchmarked through several networks from the DREAM challenge and the widely used SOS DNA repair network in Escherichia coli. The results indicate that the CN algorithm is suitable for learning GRNs and it considerably improves the precision of network inference. The source of data sets and codes are available at . PMID:25607659

  16. Limitations in Life Participation and Independence Due to Secondary Conditions

    ERIC Educational Resources Information Center

    Koritsas, Stella; Iacono, Teresa

    2009-01-01

    The effects of secondary conditions across adults with autism, Down syndrome, and cerebral palsy were explored in terms of overall limitation in life participation and independence, changes over time, and the degree and nature of limitation in specific secondary conditions. Information was obtained for 35 adults with autism, 49 with Down syndrome,…

  17. Limitations in Life Participation and Independence Due to Secondary Conditions

    ERIC Educational Resources Information Center

    Koritsas, Stella; Iacono, Teresa

    2009-01-01

    The effects of secondary conditions across adults with autism, Down syndrome, and cerebral palsy were explored in terms of overall limitation in life participation and independence, changes over time, and the degree and nature of limitation in specific secondary conditions. Information was obtained for 35 adults with autism, 49 with Down syndrome,…

  18. Temporal Limitations in the Effective Binding of Attended Target Attributes in the Mutual Masking of Visual Objects

    ERIC Educational Resources Information Center

    Hommuk, Karita; Bachmann, Talis

    2009-01-01

    The problem of feature binding has been examined under conditions of distributed attention or with spatially dispersed stimuli. We studied binding by asking whether selective attention to a feature of a masked object enables perceptual access to the other features of that object using conditions in which spatial attention was directed at a single…

  19. Temporal Limitations in the Effective Binding of Attended Target Attributes in the Mutual Masking of Visual Objects

    ERIC Educational Resources Information Center

    Hommuk, Karita; Bachmann, Talis

    2009-01-01

    The problem of feature binding has been examined under conditions of distributed attention or with spatially dispersed stimuli. We studied binding by asking whether selective attention to a feature of a masked object enables perceptual access to the other features of that object using conditions in which spatial attention was directed at a single…

  20. Frontier mutualism: coevolutionary patterns at the northern range limit of the leaf-cutter ant–fungus symbiosis

    PubMed Central

    Mueller, Ulrich G.; Mikheyev, Alexander S.; Solomon, Scott E.; Cooper, Michael

    2011-01-01

    Tropical leaf-cutter ants cultivate the fungus Attamyces bromatificus in a many-to-one, diffuse coevolutionary relationship where ant and fungal partners re-associate frequently over time. To evaluate whether ant–Attamyces coevolution is more specific (tighter) in peripheral populations, we characterized the host-specificities of Attamyces genotypes at their northern, subtropical range limits (southern USA, Mexico and Cuba). Population-genetic patterns of northern Attamyces reveal features that have so far not been observed in the diffusely coevolving, tropical ant–Attamyces associations. These unique features include (i) cases of one-to-one ant–Attamyces specialization that tighten coevolution at the northern frontier; (ii) distributions of genetically identical Attamyces clones over large areas (up to 81 000 km2, approx. the area of Ireland, Austria or Panama); (iii) admixture rates between Attamyces lineages that appear lower in northern than in tropical populations; and (iv) long-distance gene flow of Attamyces across a dispersal barrier for leaf-cutter ants (ocean between mainland North America and Cuba). The latter suggests that Attamyces fungi may occasionally disperse independently of the ants, contrary to the traditional assumption that Attamyces fungi depend entirely on leaf-cutter queens for dispersal. Peripheral populations in Argentina or at mid-elevation sites in the Andes may reveal additional regional variants in ant–Attamyces coevolution. Studies of such populations are most likely to inform models of coextinctions of obligate mutualistic partners that are doubly stressed by habitat marginality and by environmental change. PMID:21389026

  1. Trends in activity-limiting chronic conditions among children.

    PubMed Central

    Newacheck, P W; Budetti, P P; Halfon, N

    1986-01-01

    Data from the National Health Interview Survey indicate that the prevalence of activity-limiting chronic conditions among children under age 17 years doubled between 1960 and 1981, from 1.8 to 3.8 per cent. Approximately 40 per cent of the overall rise in prevalence occurred before 1970. Most of the increase in prevalence during this early period can be attributed to changes in questionnaire design and aging of the child population following the "baby boom" years. The factors responsible for increases in reported cases of activity limitation following 1970 are more difficult to specify and evaluate. During this later period, the increase in prevalence was restricted to less severe levels of limitations. While prevalence levels rose for a variety of conditions during this period, respiratory conditions and mental and nervous system disorders demonstrated the largest changes. It appears that much of the increase in reported cases of activity limitations during the 1970s can be attributed to shifting perceptions on the part of parents, educators, and physicians. PMID:2936257

  2. Flammability Limits of Gases Under Low Gravity Conditions

    NASA Technical Reports Server (NTRS)

    Strehlow, R. A.

    1985-01-01

    The purpose of this combustion science investigation is to determine the effect of zero, fractional, and super gravity on the flammability limits of a premixed methane air flame in a standard 51 mm diameter flammability tube and to determine, if possible, the fluid flow associated with flame passage under zero-g conditions and the density (and hence, temperature) profiles associated with the flame under conditions of incipient extinction. This is accomplished by constructing an appropriate apparatus for placement in NASA's Lewis Research Center Lear Jet facility and flying the prescribed g-trajectories while the experiment is being performed. Data is recorded photographically using the visible light of the flame. The data acquired is: (1) the shape and propagation velocity of the flame under various g-conditions for methane compositions that are inside the flammable limits, and (2) the effect of gravity on the limits. Real time accelerometer readings for the three orthogonal directions are displayed in full view of the cameras and the framing rate of the cameras is used to measure velocities.

  3. Biological conversion of synthesis gas. Limiting conditions/scale-up

    SciTech Connect

    Basu, R.; Klasson, K.T.; Takriff, M.; Clausen, E.C.; Gaddy, J.L.

    1993-09-01

    The purpose of this research is to develop a technically and economically feasible process for biologically producing H(sub 2) from synthesis gas while, at the same time, removing harmful sulfur gas compounds. Six major tasks are being studied: 1. Culture development, where the best cultures are selected and conditions optimized for simultaneous hydrogen production and sulfur gas removal; 2. Mass transfer and kinetic studies in which equations necessary for process design are developed; 3. Bioreactor design studies, where the cultures chosen in Task 1 are utilized in continuous reaction vessels to demonstrate process feasibility and define operating conditions; 4. Evaluation of biological synthetic gas conversion under limiting conditions in preparation for industrial demonstration studies; 5. Process scale-up where laboratory data are scaled to larger-size units in preparation for process demonstration in a pilot-scale unit; and 6. Economic evaluation, where process simulations are used to project process economics and identify high cost areas during sensitivity analyses.

  4. [Biological mutualism, concepts and models].

    PubMed

    Perru, Olivier

    2011-01-01

    Mutualism is a biological association for a mutual benefit between two different species. In this paper, firstly, we examine the history and signification of mutualism in relation to symbiosis. Then, we consider the link between concepts and models of mutualism. Models of mutualism depend on different concepts we use: If mutualism is situated at populations' level, it will be expressed by Lotka-Volterra models, concerning exclusively populations' size. If mutualism is considered as a resources' exchange or a biological market increasing the fitness of these organisms, it will be described at an individual level by a cost-benefit model. Our analysis will be limited to the history and epistemology of Lotka-Volterra models and we hypothesize that these models are adapted at first to translate dynamic evolutions of mutualism. They render stability or variations of size and assume that there are clear distinctions and a state of equilibrium between populations of different species. Italian mathematician Vito Volterra demonstrated that biological associations consist in a constant relation between some species. In 1931 and 1935, Volterra described the general form of antagonistic or mutualistic biological associations by the same differential equations. We recognize that these equations have been more used to model competition or prey-predator interactions, but a simple sign change allows describing mutualism. The epistemological problem is the following: Volterra's equations help us to conceptualize a global phenomenon. However, mutualistic interactions may have stronger effects away from equilibrium and these effects may be better understood at individual level. We conclude that, between 1985 and 2000, some researchers carried on working and converting Lotka-Volterra models but this description appeared as insufficient. So, other researchers adopted an economical viewpoint, considering mutualism as a biological market. PMID:22288336

  5. Oxygen Consumption Rates of Bacteria under Nutrient-Limited Conditions

    PubMed Central

    Riedel, Timothy E.; Nealson, Kenneth H.; Finkel, Steven E.

    2013-01-01

    Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures of Escherichia coli K-12, Shewanella oneidensis MR-1, and Marinobacter aquaeolei VT8 were tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than 2 orders of magnitude for all three strains as they transitioned from nutrient-abundant log-phase growth to the nutrient-limited early stationary phase. The large reduction in QO2 from growth to stationary phase suggests that nutrient availability is an important factor in considering environmental respiration rates. Following the death phase, during the long-term stationary phase (LTSP), QO2 values of the surviving population increased with time and more cells were respiring than formed colonies. Within the respiring population, a subpopulation of highly respiring cells increased in abundance with time. Apparently, as cells enter LTSP, there is a viable but not culturable population whose bulk community and per cell respiration rates are dynamic. This result has a bearing on how minimal energy requirements are met, especially in nutrient-limited environments. The minimal QO2 rates support the extension of Kleiber's law to the mass of a bacterium (100-fg range). PMID:23770901

  6. Amyloid Fibrillation of Insulin under Water-Limited Conditions

    PubMed Central

    Choi, Tae Su; Lee, Jong Wha; Jin, Kyeong Sik; Kim, Hugh I.

    2014-01-01

    Amyloid fibrillation in water-organic mixtures has been widely studied to understand the effect of protein-solvent interactions on the fibrillation process. In this study, we monitored insulin fibrillation in formamide and its methyl derivatives (formamide, N-methyl formamide, N,N-dimethyl formamide) in the presence and absence of water. These model solvent systems mimic the cellular environment by providing denaturing conditions and a hydrophobic environment with limited water content. Thioflavin T (ThT) assay revealed that binary mixtures of water with formamide and its methyl derivatives enhanced fibrillation rates and β-sheet abundance, whereas organic solvents suppressed insulin fibrillation. We utilized solution small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC) to investigate the correlation between protein-solvent interactions and insulin fibrillation. SAXS experiments combined with simulated annealing of the protein indicated that the degree of denaturation of the hydrophobic core region at residues B11–B17 determines the fibrillation rate. In addition, DSC experiments suggested a crucial role of hydrophobic interactions in the fibrillation process. These results imply that an environment with limited water, which imitates a lipid membrane system, accelerates protein denaturation and the formation of intermolecular hydrophobic interactions during amyloid fibrillation. PMID:25418175

  7. Bacteriophages Limit the Existence Conditions for Conjugative Plasmids

    PubMed Central

    Wood, A. Jamie; Dytham, Calvin; Pitchford, Jonathan W.; Truman, Julie; Spiers, Andrew; Paterson, Steve; Brockhurst, Michael A.

    2015-01-01

    ABSTRACT Bacteriophages are a major cause of bacterial mortality and impose strong selection on natural bacterial populations, yet their effects on the dynamics of conjugative plasmids have rarely been tested. We combined experimental evolution, mathematical modeling, and individual-based simulations to explain how the ecological and population genetics effects of bacteriophages upon bacteria interact to determine the dynamics of conjugative plasmids and their persistence. The ecological effects of bacteriophages on bacteria are predicted to limit the existence conditions for conjugative plasmids, preventing persistence under weak selection for plasmid accessory traits. Experiments showed that phages drove faster extinction of plasmids in environments where the plasmid conferred no benefit, but they also revealed more complex effects of phages on plasmid dynamics under these conditions, specifically, the temporary maintenance of plasmids at fixation followed by rapid loss. We hypothesized that the population genetic effects of bacteriophages, specifically, selection for phage resistance mutations, may have caused this. Further mathematical modeling and individual-based simulations supported our hypothesis, showing that conjugative plasmids may hitchhike with phage resistance mutations in the bacterial chromosome. PMID:26037122

  8. First-wall and limiter conditioning in TFTR

    SciTech Connect

    Dylla, H.F.; Blanchard, W.R.; Hawryluk, R.J.; Hill, K.W.; Krawchuk, R.B.; Mueller, D.; Owens, D.K.; Ramsey, A.T.; Sesnic, S.; Tenney, F.H.

    1984-10-01

    A progress report on the experimental studies of vacuum vessel conditioning during the first year of TFTR operation is presented. A previous paper described the efforts expended to condition the TFTR vessel prior to and during the initial plasma start-up experiments. During the start-up phase, discharge cleaning was performed with the vessel at room temperature. For the second phase of TFTR operations, which was directed towards the optimization of ohmically heated plasmas, the vacuum vessel could be heated to 150/sup 0/C. The internal configuration of the TFTR vessel was more complex during the second phase with the addition of a TiC/C moveable limiter array, Inconel bellows cover plates, and ZrAl getter pumps. A quantitative comparison is given on the effectiveness of vessel bakeout, glow discharge cleaning, and pulse discharge cleaning in terms of the total quantity of removed carbon and oxygen, residual gas base pressures and the resulting plasma impurity levels as measured by visible, uv, and soft x-ray spectroscopy. The initial experience with hydrogen isotope changeover in TFTR is presented including the results of the attempt to hasten the changeover time by using a glow discharge to precondition the vessel with the new isotope.

  9. The evolution of mutualism.

    PubMed

    Leigh, E G

    2010-12-01

    Like altruism, mutualism, cooperation between species, evolves only by enhancing all participants' inclusive fitness. Mutualism evolves most readily between members of different kingdoms, which pool complementary abilities for mutual benefit: some of these mutualisms represent major evolutionary innovations. Mutualism cannot persist if cheating annihilates its benefits. In long-term mutualisms, symbioses, at least one party associates with the other nearly all its life. Usually, a larger host harbours smaller symbionts. Cheating is restrained by vertical transmission, as in Buchnera; partner fidelity, as among bull-thorn acacias and protective ants; test-based choice of symbionts, as bobtail squid choose bioluminescent bacteria; or sanctioning nonperforming symbionts, as legumes punish nonperforming nitrogen-fixing bacteria. Mutualisms involving brief exchanges, as among plants and seed-dispersers, however, persist despite abundant cheating. Both symbioses and brief-exchange mutualisms have transformed whole ecosystems. These mutualisms may be steps towards ecosystems which, like Adam Smith's ideal economy, serve their members' common good. PMID:20942825

  10. Forecasting Urban Water Demand via Machine Learning Methods Coupled with a Bootstrap Rank-Ordered Conditional Mutual Information Input Variable Selection Method

    NASA Astrophysics Data System (ADS)

    Adamowski, J. F.; Quilty, J.; Khalil, B.; Rathinasamy, M.

    2014-12-01

    This paper explores forecasting short-term urban water demand (UWD) (using only historical records) through a variety of machine learning techniques coupled with a novel input variable selection (IVS) procedure. The proposed IVS technique termed, bootstrap rank-ordered conditional mutual information for real-valued signals (brCMIr), is multivariate, nonlinear, nonparametric, and probabilistic. The brCMIr method was tested in a case study using water demand time series for two urban water supply system pressure zones in Ottawa, Canada to select the most important historical records for use with each machine learning technique in order to generate forecasts of average and peak UWD for the respective pressure zones at lead times of 1, 3, and 7 days ahead. All lead time forecasts are computed using Artificial Neural Networks (ANN) as the base model, and are compared with Least Squares Support Vector Regression (LSSVR), as well as a novel machine learning method for UWD forecasting: the Extreme Learning Machine (ELM). Results from one-way analysis of variance (ANOVA) and Tukey Honesty Significance Difference (HSD) tests indicate that the LSSVR and ELM models are the best machine learning techniques to pair with brCMIr. However, ELM has significant computational advantages over LSSVR (and ANN) and provides a new and promising technique to explore in UWD forecasting.

  11. Plant invasions--the role of mutualisms.

    PubMed

    Richardson, D M; Allsopp, N; D'Antonio, C M; Milton, S J; Rejmánek, M

    2000-02-01

    Many introduced plant species rely on mutualisms in their new habitats to overcome barriers to establishment and to become naturalized and, in some cases, invasive. Mutualisms involving animal-mediated pollination and seed dispersal, and symbioses between plant roots and microbiota often facilitate invasions. The spread of many alien plants, particularly woody ones, depends on pollinator mutualisms. Most alien plants are well served by generalist pollinators (insects and birds), and pollinator limitation does not appear to be a major barrier for the spread of introduced plants (special conditions relating to Ficus and orchids are described). Seeds of many of the most notorious plant invaders are dispersed by animals, mainly birds and mammals. Our review supports the view that tightly coevolved, plant-vertebrate seed dispersal systems are extremely rare. Vertebrate-dispersed plants are generally not limited reproductively by the lack of dispersers. Most mycorrhizal plants form associations with arbuscular mycorrhizal fungi which, because of their low specificity, do not seem to play a major role in facilitating or hindering plant invasions (except possibly on remote islands such as the Galapagos which are poor in arbuscular mycorrhizal fungi). The lack of symbionts has, however, been a major barrier for many ectomycorrhizal plants, notably for Pinus spp. in parts of the southern hemisphere. The roles of nitrogen-fixing associations between legumes and rhizobia and between actinorhizal plants and Frankia spp. in promoting or hindering invasions have been virtually ignored in the invasions literature. Symbionts required to induce nitrogen fixation in many plants are extremely widespread, but intentional introductions of symbionts have altered the invasibility of many, if not most, systems. Some of the world's worst invasive alien species only invaded after the introduction of symbionts. Mutualisms in the new environment sometimes re-unite the same species that form partnerships in the native range of the plant. Very often, however, different species are involved, emphasizing the diffuse nature of many (most) mutualisms. Mutualisms in new habitats usually duplicate functions or strategies that exist in the natural range of the plant. Occasionally, mutualisms forge totally novel combinations, with profound implications for the behaviour of the introduced plant in the new environment (examples are seed dispersal mutualisms involving wind-dispersed pines and cockatoos in Australia; and mycorrhizal associations involving plant roots and fungi). Many ecosystems are becoming more susceptible to invasion by introduced plants because: (a) they contain an increasing array of potential mutualistic partners (e.g. generalist frugivores and pollinators, mycorrhizal fungi with wide host ranges, rhizobia strains with infectivity across genera); and (b) conditions conductive for the establishment of various alien/alien synergisms are becoming more abundant. Incorporating perspectives on mutualisms in screening protocols will improve (but not perfect) our ability to predict whether a given plant species could invade a particular habitat. PMID:10740893

  12. Conditions for diffusion-limited and reaction-limited recombination in nanostructured solar cells.

    PubMed

    Ansari-Rad, Mehdi; Anta, Juan A; Arzi, Ezatollah

    2014-04-01

    The performance of Dye-sensitized solar cells (DSC) and related devices made of nanostructured semiconductors relies on a good charge separation, which in turn is achieved by favoring charge transport against recombination. Although both processes occur at very different time scales, hence ensuring good charge separation, in certain cases the kinetics of transport and recombination can be connected, either in a direct or an indirect way. In this work, the connection between electron transport and recombination in nanostructured solar cells is studied both theoretically and by Monte Carlo simulation. Calculations using the Multiple-Trapping model and a realistic trap distribution for nanostructured TiO2 show that for attempt-to-jump frequencies higher than 10(11)-10(13) Hz, the system adopts a reaction limited (RL) regime, with a lifetime which is effectively independent from the speed of the electrons in the transport level. For frequencies lower than those, and depending on the concentration of recombination centers in the material, the system enters a diffusion-limited regime (DL), where the lifetime increases if the speed of free electrons decreases. In general, the conditions for RL or DL recombination depend critically on the time scale difference between recombination kinetics and free-electron transport. Hence, if the former is too rapid with respect to the latter, the system is in the DL regime and total thermalization of carriers is not possible. In the opposite situation, a RL regime arises. Numerical data available in the literature, and the behavior of the lifetime with respect to (1) density of recombination centers and (2) probability of recombination at a given center, suggest that a typical DSC in operation stays in the RL regime with complete thermalization, although a transition to the DL regime may occur for electrolytes or hole conductors where recombination is especially rapid or where there is a larger dispersion of energies of electron acceptors. PMID:24712803

  13. Conditions for diffusion-limited and reaction-limited recombination in nanostructured solar cells

    SciTech Connect

    Ansari-Rad, Mehdi; Department of Physics, University of Shahrood, Shahrood ; Anta, Juan A.; Arzi, Ezatollah

    2014-04-07

    The performance of Dye-sensitized solar cells (DSC) and related devices made of nanostructured semiconductors relies on a good charge separation, which in turn is achieved by favoring charge transport against recombination. Although both processes occur at very different time scales, hence ensuring good charge separation, in certain cases the kinetics of transport and recombination can be connected, either in a direct or an indirect way. In this work, the connection between electron transport and recombination in nanostructured solar cells is studied both theoretically and by Monte Carlo simulation. Calculations using the Multiple-Trapping model and a realistic trap distribution for nanostructured TiO{sub 2} show that for attempt-to-jump frequencies higher than 10{sup 11}–10{sup 13} Hz, the system adopts a reaction limited (RL) regime, with a lifetime which is effectively independent from the speed of the electrons in the transport level. For frequencies lower than those, and depending on the concentration of recombination centers in the material, the system enters a diffusion-limited regime (DL), where the lifetime increases if the speed of free electrons decreases. In general, the conditions for RL or DL recombination depend critically on the time scale difference between recombination kinetics and free-electron transport. Hence, if the former is too rapid with respect to the latter, the system is in the DL regime and total thermalization of carriers is not possible. In the opposite situation, a RL regime arises. Numerical data available in the literature, and the behavior of the lifetime with respect to (1) density of recombination centers and (2) probability of recombination at a given center, suggest that a typical DSC in operation stays in the RL regime with complete thermalization, although a transition to the DL regime may occur for electrolytes or hole conductors where recombination is especially rapid or where there is a larger dispersion of energies of electron acceptors.

  14. 43 CFR 2741.7 - Acreage limitations and general conditions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PURPOSES ACT Recreation and Public Purposes Act: Requirements § 2741.7 Acreage limitations and general... roadside parks and rest sites of 10 acres or less each. (2) Any State or agency or instrumentality of such... one calendar year to receive 6,400 acres (not counting public lands for small roadside parks and...

  15. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot has... are free of frost, ice, or snow. (2) The certificate holder has an approved alternative procedure...

  16. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot has... are free of frost, ice, or snow. (2) The certificate holder has an approved alternative procedure...

  17. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot has... are free of frost, ice, or snow. (2) The certificate holder has an approved alternative procedure...

  18. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot has... are free of frost, ice, or snow. (2) The certificate holder has an approved alternative procedure...

  19. Biological effects of extreme environmental conditions. [considering limits of biosphere

    NASA Technical Reports Server (NTRS)

    Imshenetskiy, A. A.

    1975-01-01

    Actions of extreme physical and chemical space factors on microorganisms and plants are elaborated in order to establish limits for the biosphere. Considered are effects of low and high temperatures; ionizing and ultraviolet radiation; various gases; and effects of vibration, desiccation and acceleration.

  20. Conditioning in Stuttering Therapy: Applications and Limitations. Publication No. 7.

    ERIC Educational Resources Information Center

    Starkweather, C. Woodruff, Ed.

    Presented are seven papers given at a conference on the application of behavior modification techniques to the treatment of stuttering. An introduction to the papers gives an overview of behavior modification. The two papers of Part I present two approaches to stuttering therapy, one of which is based on operant conditioning and the other on…

  1. The Limits of Knowledge Management in Contemporary Corporate Conditions

    ERIC Educational Resources Information Center

    Garrick, John

    2014-01-01

    This paper draws on Jean-François Lyotard's (1984) seminal study "The Postmodern Condition: A Report on Knowledge" to reflect on two macro-level catastrophes: the global financial crisis (GFC) of 2009 (and its continuing effects throughout the Eurozone and elsewhere) and Fukushima. These two case studies probe aspects of these grand…

  2. 33 CFR 330.4 - Conditions, limitations, and restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determined to be an historic property in accordance with 33 CFR part 325, appendix C, the DE will take into... district engineer may: (i) After complying with the requirements of 33 CFR part 325, appendix C, authorize... comply with the provisions of 33 CFR 325.4. In the latter case, the conditioned 401 water...

  3. The Limits of Knowledge Management in Contemporary Corporate Conditions

    ERIC Educational Resources Information Center

    Garrick, John

    2014-01-01

    This paper draws on Jean-François Lyotard's (1984) seminal study "The Postmodern Condition: A Report on Knowledge" to reflect on two macro-level catastrophes: the global financial crisis (GFC) of 2009 (and its continuing effects throughout the Eurozone and elsewhere) and Fukushima. These two case studies probe aspects of these grand…

  4. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... adhering to any propeller, windshield, wing, stabilizing or control surface, to a powerplant installation, or to an airspeed, altimeter, rate of climb, or flight attitude instrument system, except under the follow conditions: (1) Takeoffs may be made with frost adhering to the wings, or stabilizing or...

  5. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... or control surface, to a powerplant installation, or to an airspeed, altimeter, rate of climb, or flight attitude instrument system, except under the following conditions: (1) Takeoffs may be made with frost adhering to the wings, or stabilizing or control surfaces, if the frost has been polished to...

  6. 33 CFR 330.4 - Conditions, limitations, and restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... comply with the provisions of 33 CFR 325.4. In the latter case, the conditioned 401 water quality... event shall the period exceed one (1) year (see 33 CFR 325.2(b)(1)(ii)). Upon receipt of an individual... provisions of 33 CFR 325.4 or believes for some other specific reason it would be inappropriate to...

  7. 33 CFR 330.4 - Conditions, limitations, and restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... comply with the provisions of 33 CFR 325.4. In the latter case, the conditioned 401 water quality... event shall the period exceed one (1) year (see 33 CFR 325.2(b)(1)(ii)). Upon receipt of an individual... provisions of 33 CFR 325.4 or believes for some other specific reason it would be inappropriate to...

  8. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface... pilot may take off an airplane any time conditions are such that frost, ice, or snow may reasonably be... is a check to make sure the wings and control surfaces are free of frost, ice, or snow. (2)...

  9. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface... pilot may take off an airplane any time conditions are such that frost, ice, or snow may reasonably be... is a check to make sure the wings and control surfaces are free of frost, ice, or snow. (2)...

  10. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface... pilot may take off an airplane any time conditions are such that frost, ice, or snow may reasonably be... is a check to make sure the wings and control surfaces are free of frost, ice, or snow. (2)...

  11. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface... pilot may take off an airplane any time conditions are such that frost, ice, or snow may reasonably be... is a check to make sure the wings and control surfaces are free of frost, ice, or snow. (2)...

  12. Evolution of mutualism between species

    SciTech Connect

    Post, W.M.; Travis, C.C.; DeAngelis, D.L.

    1980-01-01

    Recent theoretical work on mutualism, the interaction between species populations that is mutually beneficial, is reviewed. Several ecological facts that should be addressed in the construction of dynamic models for mutualism are examined. Basic terminology is clarified. (PSB)

  13. Behavioral Ecology: Manipulative Mutualism.

    PubMed

    Hughes, David P

    2015-09-21

    A new study reveals that an apparent mutualism between lycaenid caterpillars and their attendant ants may not be all it seems, as the caterpillars produce secretions that modify the brains and behavior of their attendant ants. PMID:26394105

  14. Generalized mutual information and Tsirelson's bound

    SciTech Connect

    Wakakuwa, Eyuri; Murao, Mio

    2014-12-04

    We introduce a generalization of the quantum mutual information between a classical system and a quantum system into the mutual information between a classical system and a system described by general probabilistic theories. We apply this generalized mutual information (GMI) to a derivation of Tsirelson's bound from information causality, and prove that Tsirelson's bound can be derived from the chain rule of the GMI. By using the GMI, we formulate the 'no-supersignalling condition' (NSS), that the assistance of correlations does not enhance the capability of classical communication. We prove that NSS is never violated in any no-signalling theory.

  15. 29 CFR Appendix A to Subpart Y of... - Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions A Appendix A to Subpart Y of Part 1926 Labor Regulations Relating to Labor... REGULATIONS FOR CONSTRUCTION Diving Pt. 1926, Subpt. Y, App. A Appendix A to Subpart Y of Part...

  16. 29 CFR Appendix A to Subpart Y of... - Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions A Appendix A to Subpart Y of Part 1926 Labor Regulations Relating to Labor... REGULATIONS FOR CONSTRUCTION Diving Pt. 1926, Subpt. Y, App. A Appendix A to Subpart Y of Part...

  17. 77 FR 69785 - Public Use Limit on Commercial Dog Walking; Revised Disposal Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-21

    ... Part 1002 Public Use Limit on Commercial Dog Walking; Revised Disposal Conditions AGENCY: The Presidio... a public use limit on persons who are walking four or more dogs at one time in Area B of the Presidio of San Francisco (Presidio) for consideration (Commercial Dog Walkers). The limit will require...

  18. Phase stability limit of c-BN under hydrostatic and non-hydrostatic pressure conditions

    SciTech Connect

    Xiao, Jianwei; Du, Jinglian; Wen, Bin Zhang, Xiangyi; Melnik, Roderick; Kawazoe, Yoshiyuki

    2014-04-28

    Phase stability limit of cubic boron nitride (c-BN) has been investigated by the crystal structure search technique. It indicated that this limit is ?1000 GPa at hydrostatic pressure condition. Above this pressure, c-BN turns into a metastable phase with respect to rocksalt type boron nitride (rs-BN). However, rs-BN cannot be retained at 0 GPa owing to its instability at pressure below 250 GPa. For non-hydrostatic pressure conditions, the phase stability limit of c-BN is substantially lower than that under hydrostatic pressure conditions and it is also dramatically different for other pressure mode.

  19. Phenological shifts and the fate of mutualisms

    PubMed Central

    Rafferty, Nicole E.; CaraDonna, Paul J.; Bronstein, Judith L.

    2014-01-01

    Climate change is altering the timing of life history events in a wide array of species, many of which are involved in mutualistic interactions. Because many mutualisms can form only if partner species are able to locate each other in time, differential phenological shifts are likely to influence their strength, duration and outcome. At the extreme, climate change-driven shifts in phenology may result in phenological mismatch: the partial or complete loss of temporal overlap of mutualistic species. We have a growing understanding of how, when, and why phenological change can alter one type of mutualism–pollination. However, as we show here, there has been a surprising lack of attention to other types of mutualism. We generate a set of predictions about the characteristics that may predispose mutualisms in general to phenological mismatches. We focus not on the consequences of such mismatches but rather on the likelihood that mismatches will develop. We explore the influence of three key characteristics of mutualism: 1) intimacy, 2) seasonality and duration, and 3) obligacy and specificity. We predict that the following characteristics of mutualism may increase the likelihood of phenological mismatch: 1) a non-symbiotic life history in which co-dispersal is absent; 2) brief, seasonal interactions; and 3) facultative, generalized interactions. We then review the limited available data in light of our a priori predictions and point to mutualisms that are more and less likely to be at risk of becoming phenologically mismatched, emphasizing the need for research on mutualisms other than plant–pollinator interactions. Future studies should explicitly focus on mutualism characteristics to determine whether and how changing phenologies will affect mutualistic interactions. PMID:25883391

  20. 78 FR 6273 - Public Use Limit on Commercial Dog Walking; Revised Disposal Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... proposed rule published November 21, 2012 (77 FR 69785-69788) is extended. Comments are due February 25... Part 1002 Public Use Limit on Commercial Dog Walking; Revised Disposal Conditions AGENCY: The Presidio... requesting public comment on a proposed public use limit on persons who are walking four or more dogs at...

  1. Drug susceptibility and biofilm formation of Burkholderia pseudomallei in nutrient-limited condition.

    PubMed

    Anutrakunchai, C; Sermswan, R W; Wongratanacheewin, S; Puknun, A; Taweechaisupapong, S

    2015-06-01

    Burkholderia pseudomallei is the causative agent of melioidosis, which can form biofilms and microcolonies in vivo and in vitro. One of the hallmark characteristics of the biofilm-forming bacteria is that they can be up to 1,000 times more resistant to antibiotics than their free-living counterpart. Bacteria also become highly tolerant to antibiotics when nutrients are limited. One of the most important causes of starvation induced tolerance in vivo is biofilm growth. However, the effect of nutritional stress on biofilm formation and drug tolerance of B. pseudomallei has never been reported. Therefore, this study aims to determine the effect of nutrient-limited and enriched conditions on drug susceptibility of B. pseudomallei in both planktonic and biofilm forms in vitro using broth microdilution method and Calgary biofilm device, respectively. The biofilm formation of B. pseudomallei in nutrient-limited and enriched conditions was also evaluated by a modified microtiter-plate test. Six isolates of ceftazidime (CAZ)-susceptible and four isolates of CAZ-resistant B. pseudomallei were used. The results showed that the minimum bactericidal concentrations of CAZ against B. pseudomallei in nutrient-limited condition were higher than those in enriched condition. The drug susceptibilities of B. pseudomallei biofilm in both enriched and nutrient-limited conditions were more tolerant than those of planktonic cells. Moreover, the quantification of biofilm formation by B. pseudomallei in nutrient-limited condition was significantly higher than that in enriched condition. These data indicate that nutrient-limited condition could induce biofilm formation and drug tolerance of B. pseudomallei. PMID:26691259

  2. Biomass and cellulosic ethanol production of forage sorghum under limited water conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage sorghum is one of the suggested crops to provide feedstock for biofuel production under water-limited conditions due to its stress tolerance and efficient water use; however, research is needed under these conditions to better understand its energy yield potential. This study presents result...

  3. 42 CFR 410.23 - Screening for glaucoma: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Screening for glaucoma: Conditions for and... Medical and Other Health Services § 410.23 Screening for glaucoma: Conditions for and limitations on... mellitus. (ii) Individual with a family history of glaucoma. (iii) African-Americans age 50 and over....

  4. 42 CFR 410.23 - Screening for glaucoma: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Screening for glaucoma: Conditions for and... Medical and Other Health Services § 410.23 Screening for glaucoma: Conditions for and limitations on... mellitus. (ii) Individual with a family history of glaucoma. (iii) African-Americans age 50 and over....

  5. 42 CFR 410.39 - Prostate cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Prostate cancer screening tests: Conditions for and... Medical and Other Health Services § 410.39 Prostate cancer screening tests: Conditions for and limitations... of early detection of prostate cancer: (i) A screening digital rectal examination. (ii) A...

  6. 42 CFR 410.39 - Prostate cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Prostate cancer screening tests: Conditions for and... Medical and Other Health Services § 410.39 Prostate cancer screening tests: Conditions for and limitations... cancer screening tests means any of the following procedures furnished to an individual for the...

  7. 42 CFR 410.39 - Prostate cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Prostate cancer screening tests: Conditions for and... Medical and Other Health Services § 410.39 Prostate cancer screening tests: Conditions for and limitations... cancer screening tests means any of the following procedures furnished to an individual for the...

  8. 42 CFR 410.39 - Prostate cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Prostate cancer screening tests: Conditions for and... Medical and Other Health Services § 410.39 Prostate cancer screening tests: Conditions for and limitations... cancer screening tests means any of the following procedures furnished to an individual for the...

  9. 42 CFR 410.39 - Prostate cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Prostate cancer screening tests: Conditions for and... Medical and Other Health Services § 410.39 Prostate cancer screening tests: Conditions for and limitations... cancer screening tests means any of the following procedures furnished to an individual for the...

  10. Conditional cooling limit for a quantum channel going through an incoherent environment.

    PubMed

    Straka, Ivo; Miková, Martina; Mi?uda, Michal; Dušek, Miloslav; Ježek, Miroslav; Filip, Radim

    2015-01-01

    We propose and experimentally verify a cooling limit for a quantum channel going through an incoherent environment. The environment consists of a large number of independent non-interacting and non-interfering elementary quantum systems--qubits. The qubits travelling through the channel can only be randomly replaced by environmental qubits. We investigate a conditional cooling limit that exploits an additional probing output. The limit specifies when the single-qubit channel is quantum, i.e. it preserves entanglement. It is a fundamental condition for entanglement-based quantum technology. PMID:26568362

  11. Conditional cooling limit for a quantum channel going through an incoherent environment

    PubMed Central

    Straka, Ivo; Miková, Martina; Mi?uda, Michal; Dušek, Miloslav; Ježek, Miroslav; Filip, Radim

    2015-01-01

    We propose and experimentally verify a cooling limit for a quantum channel going through an incoherent environment. The environment consists of a large number of independent non-interacting and non-interfering elementary quantum systems – qubits. The qubits travelling through the channel can only be randomly replaced by environmental qubits. We investigate a conditional cooling limit that exploits an additional probing output. The limit specifies when the single-qubit channel is quantum, i.e. it preserves entanglement. It is a fundamental condition for entanglement-based quantum technology. PMID:26568362

  12. Conditional cooling limit for a quantum channel going through an incoherent environment

    NASA Astrophysics Data System (ADS)

    Straka, Ivo; Miková, Martina; Mi?uda, Michal; Dušek, Miloslav; Ježek, Miroslav; Filip, Radim

    2015-11-01

    We propose and experimentally verify a cooling limit for a quantum channel going through an incoherent environment. The environment consists of a large number of independent non-interacting and non-interfering elementary quantum systems – qubits. The qubits travelling through the channel can only be randomly replaced by environmental qubits. We investigate a conditional cooling limit that exploits an additional probing output. The limit specifies when the single-qubit channel is quantum, i.e. it preserves entanglement. It is a fundamental condition for entanglement-based quantum technology.

  13. Mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Chaturvedi, S.

    2002-08-01

    After a brief review of the notion of a full set of mutually unbiased bases in an N-dimensional Hilbert space, we summarize the work of Wootters and Fields (W K Wootters and B C Fields, Ann. Phys. 191, 363 (1989)) which gives an explicit construction for such bases for the case N=pr, where p is a prime. Further, we show how, by exploiting certain freedom in the Wootters-Fields construction, the task of explicitly writing down such bases can be simplified for the case when p is an odd prime. In particular, we express the results entirely in terms of the character vectors of the cyclic group G of order p. We also analyse the connection between mutually unbiased bases and the representations of G.

  14. Abortive initiation by bacteriophage T3 and T7 RNA polymerases under conditions of limiting substrate.

    PubMed Central

    Ling, M L; Risman, S S; Klement, J F; McGraw, N; McAllister, W T

    1989-01-01

    Initiation of RNA synthesis by the phage polymerases is abortive if the concentration of pyrimidine triphosphates is limiting. Under abortive initiation conditions the polymerases repeatedly initiate transcription but produce ribooligonucleotides that terminate just prior to the first occurrence of the limiting substrate. Abortive initiation is most severe if the limiting substrate occurs within the first 8-12 nucleotides of the nascent RNA chain and is particularly evident when UMP is limiting. The formation of stable elongation complexes (as determined by gel retardation experiments) occurs after the synthesis of an RNA product 8-12 nucleotides in length. Images PMID:2646596

  15. Conditioning of the graphite bumper limiter for enhanced confinement discharges in TFTR

    SciTech Connect

    Dylla, H.F.; LaMarche, P.H.; Ulrickson, M.; Goldston, R.J.; Heifetz, D.B.; Hill, K.W.; Ramsey, A.T.

    1987-05-01

    A strong pumping effect has been observed with plasma operation on the toroidal graphite bumper limiter on TFTR. The pumping effect was induced by conditioning the limiter with a short series (10 to 20) of low density deuterium- or helium-initiated discharges. The density decay constant (tau/sub p/*) for gas-fueled ohmic discharges was reduced from tau/sub p/* > 10 s before conditioning to a minimum value of tau/sub p/* = 0.15 s after conditioning, corresponding to a reduction in the global recycling coefficient from approx.100% to less than 50%. Coincident with the low recycling conditions, low current neutral-beam-fueled discharges show global energy confinement times which are enhanced by a factor of two over results with an unconditioned limiter. Two models are proposed for the observed pumping effects: (1) a depletion model based on pumping of hydrogenic species in the near-surface region of the limiter after depletion of the normally saturated surface layer by (carbon and helium) ion-induced desorption; and (2) a codeposition model based on pumping of hydrogenic species in carbon films sputtered from the limiter by the conditioning process.

  16. Reducing Conservatism in Aircraft Engine Response Using Conditionally Active Min-Max Limit Regulators

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Garg, Sanjay

    2012-01-01

    Current aircraft engine control logic uses a Min-Max control selection structure to prevent the engine from exceeding any safety or operational limits during transients due to throttle commands. This structure is inherently conservative and produces transient responses that are slower than necessary. In order to utilize the existing safety margins more effectively, a modification to this architecture is proposed, referred to as a Conditionally Active (CA) limit regulator. This concept uses the existing Min-Max architecture with the modification that limit regulators are active only when the operating point is close to a particular limit. This paper explores the use of CA limit regulators using a publicly available commercial aircraft engine simulation. The improvement in thrust response while maintaining all necessary safety limits is demonstrated in a number of cases.

  17. Learning curves for mutual information maximization

    NASA Astrophysics Data System (ADS)

    Urbanczik, R.

    2003-07-01

    An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed [S. Becker and G. Hinton, Nature (London) 355, 161 (1992)]. For a generic data model, I show that in the large sample limit the structure in the data is recognized by mutual information maximization. For a more restricted model, where the networks are similar to perceptrons, I calculate the learning curves for zero-temperature Gibbs learning. These show that convergence can be rather slow, and a way of regularizing the procedure is considered.

  18. [Mutual promotion, mutual assistance and mutual inhibition in the compatibility of acupoints].

    PubMed

    Yang, Fuming; Guo, Yi

    2015-10-01

    Mutual promotion, mutual assistance and mutual inhibition are commonly for the compatibility of Chinese herbs, but they are also existed among the acupoints. In the paper, the relevant literature on acupoint, compatibility was collected and the mutual promotion, mutual assistance and mutual inhibition relationships of acupoints were described. The laws of the above mentioned combinations, the theoretic evidences and modern researches were summarized briefly. The mutual promotion and mutual assistance refer to the coordination of acupoints, presenting the relationship of the primary and the secondary about the mutual assistance. Hereby, the acupoints could be divided into the simple assistant acupoints and the acupoints from the affected meridians. The mutual inhibition is used to describe the antagonism effect in acupoint combination. There are more researches on the mutual promotion of acupoint combination but less ones on the mutual inhibition and its mechanism is just hypothetic. It is very important to have the deep study on those compatibility relationships for the improvement of acupuncture efficacy and to elaborate the effect mechanism. PMID:26790211

  19. Mutual help in SETIs

    NASA Astrophysics Data System (ADS)

    Melia, F.; Frisch, D. H.

    1985-06-01

    Techniques to establish communication between earth and extraterrestrial intelligent beings are examined analytically, emphasizing that the success of searches for extraterrestrial intelligence (SETIs) depends on the selection by both sender and receiver of one of a few mutually helpful SETI strategies. An equation for estimating the probability that an SETI will result in the recognition of an ETI signal is developed, and numerical results for various SETI strategies are presented in tables. A minimum approach employing 10 40-m 20-kW dish antennas for a 30-yr SETI in a 2500-light-year disk is proposed.

  20. Modelling reference conditions for the upper limit of Posidonia oceanica meadows: a morphodynamic approach

    NASA Astrophysics Data System (ADS)

    Vacchi, Matteo; Misson, Gloria; Montefalcone, Monica; Archetti, Renata; Nike Bianchi, Carlo; Ferrari, Marco

    2014-05-01

    The upper portion of the meadows of the protected Mediterranean seagrass Posidonia oceanica occurs in the region of the seafloor mostly affected by surf-related effects. Evaluation of its status is part of monitoring programs, but proper conclusions are difficult to draw due to the lack of definite reference conditions. Comparing the position of the meadow upper limit with the beach morphodynamics (i.e. the distinctive type of beach produced by topography and wave climate) provided evidence that the natural landwards extension of meadows can be predicted. Here we present an innovative predictive cartographic approach able to identify the seafloor portion where the meadow upper limit should naturally lies (i.e. its reference conditions). The conceptual framework of this model is based on 3 essential components: i) Definition of the breaking depth geometry: the breaking limit represents the major constrain for the landward meadow development. We modelled the breaking limit (1 year return time) using the software Mike 21 sw. ii) Definition of the morphodynamic domain of the beach using the surf scaling index ?; iii) Definition of the P. oceanica upper limit geometry. We coupled detailed aerial photo with thematic bionomic cartography. In GIS environment, we modelled the seafloor extent where the meadow should naturally lies according to the breaking limit position and the morphodynamic domain of the beach. Then, we added the GIS layer with the meadow upper limit geometry. Therefore, the final output shows, on the same map, both the reference condition and the actual location of the upper limit. It make possible to assess the status of the landward extent of a given P. oceanica meadow and quantify any suspected or observed regression caused by anthropic factors. The model was elaborated and validated along the Ligurian coastline (NW Mediteraanean) and was positively tested in other Mediterranean areas.

  1. Integrating palliative care into primary care for patients with chronic, life-limiting conditions.

    PubMed

    Cleary, Ann Selena

    2016-03-15

    As longevity increases, individuals with chronic, life-limiting conditions will live longer with disease burden and functional decline. Nurse practitioners can integrate symptom management, early decision-making, and supportive care into the primary care setting to improve quality of life and decrease economic and emotional impact at the end of life. PMID:26886272

  2. 34 CFR 675.20 - Eligible employers and general conditions and limitation on employment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 3 2013-07-01 2013-07-01 false Eligible employers and general conditions and limitation on employment. 675.20 Section 675.20 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL WORK-STUDY PROGRAMS Federal Work-Study Program § 675.20...

  3. 34 CFR 675.20 - Eligible employers and general conditions and limitation on employment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 3 2012-07-01 2012-07-01 false Eligible employers and general conditions and limitation on employment. 675.20 Section 675.20 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL WORK-STUDY PROGRAMS Federal Work-Study Program § 675.20...

  4. Organisational Conditions to Boost or Limit Professional Development in the Cypriot Primary School

    ERIC Educational Resources Information Center

    Loizou, Florentia

    2014-01-01

    In this article, I examine which organisational conditions can promote or limit the professional development of teachers in the Cypriot primary school. The discussion builds on findings from a study I conducted about Cypriot primary school teachers' reflective practices (Loizou 2011). The study was qualitative and used semi-structured…

  5. 29 CFR 2590.701-3 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diabetes, generally not subject to any lifetime dollar limit. However, if an individual was diagnosed with diabetes before the effective date of coverage under the plan, diabetes coverage is subject to a lifetime... imposed by Employer U's plan, has diabetes, as well as retinal degeneration, a foot condition, and...

  6. 42 CFR 410.12 - Medical and other health services: Basic conditions and limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Medical and other health services: Basic conditions and limitations. 410.12 Section 410.12 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other Health Services § 410.12...

  7. 34 CFR 675.20 - Eligible employers and general conditions and limitation on employment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL WORK-STUDY PROGRAMS Federal Work-Study Program § 675.20 Eligible employers and general conditions and limitation on employment... nonprofit organization; or (4) A private for-profit organization. (b) Agreement between institution...

  8. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The aim of this study was to evaluate effects of PGPR (Plant Growth Promoting Rhizobacteria) isolated from rainforest on different plants under limited nitrogen conditions. Methods and Results: Bacterial isolates from a Peruvian rainforest soil were screened for plant growth promoting effects...

  9. 50 CFR 22.32 - Conditions and limitations on taking under depredation control order.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Conditions and limitations on taking under depredation control order. 22.32 Section 22.32 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION...

  10. 40 CFR 122.44 - Establishing limitations, standards, and other permit conditions (applicable to State NPDES...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7. (2) Attain or... 132.2), conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132. (s) Qualifying... limitations guidelines and standards in an NPDES permit to forego sampling of a pollutant found at 40...

  11. 40 CFR 122.44 - Establishing limitations, standards, and other permit conditions (applicable to State NPDES...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7. (2) Attain or... 132.2), conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132. (s) Qualifying... limitations guidelines and standards in an NPDES permit to forego sampling of a pollutant found at 40...

  12. 40 CFR 122.44 - Establishing limitations, standards, and other permit conditions (applicable to State NPDES...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7. (2) Attain or... 132.2), conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132. (s) Qualifying... limitations guidelines and standards in an NPDES permit to forego sampling of a pollutant found at 40...

  13. 40 CFR 122.44 - Establishing limitations, standards, and other permit conditions (applicable to State NPDES...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7. (2) Attain or... 132.2), conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132. (s) Qualifying... limitations guidelines and standards in an NPDES permit to forego sampling of a pollutant found at 40...

  14. Time-limited involvement of dorsal hippocampus in unimodal discriminative contextual conditioning.

    PubMed

    Parsons, Teresa Camille; Otto, Tim

    2010-11-01

    Converging evidence examining the effects of post-training manipulations of the hippocampus suggests that the hippocampus may play a time-limited role in the maintenance of a variety of forms of memory. In particular, either lesions or inactivation of the dorsal hippocampus results in many cases in a time-limited retrograde impairment in nondiscriminative contextual conditioning paradigms. However, the extent to which hippocampal manipulations result in a time-limited retrograde amnesia for a variety of forms of learning has recently been called into question (reviewed in Sutherland, Sparks, & Lehmann (2010)). The present study examined the effect of inactivation of the dorsal hippocampus either 7, 28, or 42 days following training in an explicitly nonspatial, discriminative contextual conditioning paradigm (Otto & Poon, 2006; Parsons & Otto, 2008). Inactivation of the dorsal hippocampus resulted in a significant deficit in the expression of contextual conditioning at 7 and 28 days, but not 42 days, following training. Importantly, inactivation of the hippocampus did not affect either baseline freezing levels or conditioning to an explicit CS. Together with previous data exploring hippocampal contributions to discriminative unimodal contextual conditioning, these data suggest that the hippocampus may play a particularly prominent role in the temporary maintenance of memory in discriminative contextual paradigms. PMID:20816992

  15. Altered CSMD1 Expression Alters Cocaine-Conditioned Place Preference: Mutual Support for a Complex Locus from Human and Mouse Models.

    PubMed

    Drgonova, Jana; Walther, Donna; Singhal, Sulabh; Johnson, Kennedy; Kessler, Brice; Troncoso, Juan; Uhl, George R

    2015-01-01

    The CUB and sushi multiple domains 1 (CSMD1) gene harbors signals provided by clusters of nearby SNPs with 10-2 > p > 10-8 associations in genome wide association (GWAS) studies of addiction-related phenotypes. A CSMD1 intron 3 SNP displays p < 10-8 association with schizophrenia and more modest associations with individual differences in performance on tests of cognitive abilities. CSDM1 encodes a cell adhesion molecule likely to influence development, connections and plasticity of brain circuits in which it is expressed. We tested association between CSMD1 genotypes and expression of its mRNA in postmortem human brains (n = 181). Expression of CSMD1 mRNA in human postmortem cerebral cortical samples differs 15-25%, in individuals with different alleles of simple sequence length and SNP polymorphisms located in the gene's third/fifth introns, providing nominal though not Bonferroni-corrected significance. These data support mice with altered CSMD1 expression as models for common human CSMD1 allelic variation. We tested baseline and/or cocaine-evoked addiction, emotion, motor and memory-related behaviors in +/- and -/- csmd1 knockout mice on mixed and on C57-backcrossed genetic backgrounds. Initial csmd1 knockout mice on mixed genetic backgrounds displayed a variety of coat colors and sizable individual differences in responses during behavioral testing. Backcrossed mice displayed uniform black coat colors. Cocaine conditioned place preference testing revealed significant influences of genotype (p = 0.02). Homozygote knockouts displayed poorer performance on aspects of the Morris water maze task. They displayed increased locomotion in some, though not all, environments. The combined data thus support roles for common level-of-expression CSMD1 variation in a drug reward phenotype relevant to addiction and in cognitive differences that might be relevant to schizophrenia. Mouse model results can complement data from human association findings of modest magnitude that identify likely polygenic influences. PMID:26171607

  16. Altered CSMD1 Expression Alters Cocaine-Conditioned Place Preference: Mutual Support for a Complex Locus from Human and Mouse Models

    PubMed Central

    Drgonova, Jana; Walther, Donna; Singhal, Sulabh; Johnson, Kennedy; Kessler, Brice; Troncoso, Juan; Uhl, George R.

    2015-01-01

    The CUB and sushi multiple domains 1 (CSMD1) gene harbors signals provided by clusters of nearby SNPs with 10-2 > p > 10-8 associations in genome wide association (GWAS) studies of addiction-related phenotypes. A CSMD1 intron 3 SNP displays p < 10-8 association with schizophrenia and more modest associations with individual differences in performance on tests of cognitive abilities. CSDM1 encodes a cell adhesion molecule likely to influence development, connections and plasticity of brain circuits in which it is expressed. We tested association between CSMD1 genotypes and expression of its mRNA in postmortem human brains (n = 181). Expression of CSMD1 mRNA in human postmortem cerebral cortical samples differs 15–25%, in individuals with different alleles of simple sequence length and SNP polymorphisms located in the gene’s third/fifth introns, providing nominal though not Bonferroni-corrected significance. These data support mice with altered CSMD1 expression as models for common human CSMD1 allelic variation. We tested baseline and/or cocaine-evoked addiction, emotion, motor and memory-related behaviors in +/- and -/- csmd1 knockout mice on mixed and on C57-backcrossed genetic backgrounds. Initial csmd1 knockout mice on mixed genetic backgrounds displayed a variety of coat colors and sizable individual differences in responses during behavioral testing. Backcrossed mice displayed uniform black coat colors. Cocaine conditioned place preference testing revealed significant influences of genotype (p = 0.02). Homozygote knockouts displayed poorer performance on aspects of the Morris water maze task. They displayed increased locomotion in some, though not all, environments. The combined data thus support roles for common level-of-expression CSMD1 variation in a drug reward phenotype relevant to addiction and in cognitive differences that might be relevant to schizophrenia. Mouse model results can complement data from human association findings of modest magnitude that identify likely polygenic influences. PMID:26171607

  17. Forming Limits in Sheet Metal Forming for Non-Proportional Loading Conditions - Experimental and Theoretical Approach

    SciTech Connect

    Ofenheimer, Aldo; Buchmayr, Bruno; Kolleck, Ralf

    2005-08-05

    The influence of strain paths (loading history) on material formability is well known in sheet forming processes. Sophisticated experimental methods are used to determine the entire shape of strain paths of forming limits for aluminum AA6016-T4 alloy. Forming limits for sheet metal in as-received condition as well as for different pre-deformation are presented. A theoretical approach based on Arrieux's intrinsic Forming Limit Stress Curve (FLSC) concept is employed to numerically predict the influence of loading history on forming severity. The detailed experimental strain paths are used in the theoretical study instead of any linear or bilinear simplified loading histories to demonstrate the predictive quality of forming limits in the state of stress.

  18. Limiter

    DOEpatents

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  19. Growth of Geobacter sulfurreducens under nutrient-limiting conditions in continuous culture.

    PubMed

    Esteve-Núñez, Abraham; Rothermich, Mary; Sharma, Manju; Lovley, Derek

    2005-05-01

    A system for growing Geobacter sulfurreducens under anaerobic conditions in chemostats was developed in order to study the physiology of this organism under conditions that might more closely approximate those found in the subsurface than batch cultures. Geobacter sulfurreducens could be cultured under acetate-limiting conditions with fumarate or Fe(III)-citrate as the electron acceptor at growth rates between 0.04 and 0.09 h(-1). The molar growth yield was threefold higher with fumarate as the electron acceptor than with Fe(III), despite the lower mid-point potential of the fumarate/succinate redox couple. When growth was limited by availability of fumarate, high steady-state concentrations were detected, suggesting that fumarate is unlikely to be an important electron acceptor in sedimentary environments. The half-saturation constant, Ks, for acetate in Fe(III)-grown cultures (10 microM) suggested that the growth of Geobacter species is likely to be acetate limited in most subsurface sediments, but that when millimolar quantities of acetate are added to the subsurface in order to promote the growth of Geobacter for bioremediation applications, this should be enough to overcome any acetate limitations. When the availability of electron acceptors, rather than acetate, limited growth, G. sulfurreducens was less efficient in incorporating acetate into biomass but had higher respiration rates, a desirable physiological characteristic when adding acetate to stimulate the activity of Geobacter species during in situ uranium bioremediation. These results demonstrate that the ability to study the growth of G. sulfurreducens under steady-state conditions can provide insights into its physiological characteristics that have relevance for its activity in a diversity of sedimentary environments. PMID:15819846

  20. Limiter

    DOEpatents

    Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  1. A water use and growth model for Eucalyptus plantation in water-limited conditions

    SciTech Connect

    Calder, I.R.

    1992-12-31

    To investigate the environmental impact of plantation forestry using fast-growing tree species in southern India, a program of field studies was initiated in 1987 specifically to measure the water use, nutrient uptake and growth rates of the plantations. A water use and growth (WAG) model is proposed for calculating transpiration and growth of Eucalyptus plantation in water-limited conditions. The model is based on the measured relationships between transpiration rate and basal cross-sectional area and soil moisture availability. The volume growth rate (in water-limited conditions) is assumed to be proportional to the volume of water transpired. The model is calibrated using (deuterium tracing) measurements of transpiration and measurements of growth recorded at the Puradal experimental plantation, Karnataka, southern India.

  2. Effect of Exogenous Siderophores on Iron Uptake Activity of Marine Bacteria under Iron-Limited Conditions

    PubMed Central

    Guan, Le Luo; Kanoh, Kaneo; Kamino, Kei

    2001-01-01

    More than 60% of species examined from a total of 421 strains of heterotrophic marine bacteria which were isolated from marine sponges and seawater were observed to have no detectable siderophore production even when Fe(III) was present in the culture medium at a concentration of 1.0 pM. The growth of one such non-siderophore-producing strain, alpha proteobacterium V0210, was stimulated under iron-limited conditions with the addition of an isolated exogenous siderophore, N,N?-bis (2,3-dihydroxybenzoyl)-O-serylserine from a Vibrio sp. Growth was also stimulated by the addition of three exogenous siderophore extracts from siderophore-producing bacteria. Radioisotope studies using 59Fe showed that the iron uptake ability of V0210 increased only with the addition of exogenous siderophores. Biosynthesis of a hydroxamate siderophore by V0210 was shown by paper electrophoresis and chemical assays for the detection of hydroxamates and catechols. An 85-kDa iron-regulated outer membrane protein was induced only under iron-limited conditions in the presence of exogenous siderophores. This is the first report of bacterial iron uptake through an induced siderophore in response to exogenous siderophores. Our results suggest that siderophores are necessary signaling compounds for growth and for iron uptake by some non-siderophore-producing marine bacteria under iron-limited conditions. PMID:11282625

  3. Role of microRNAs involved in plant response to nitrogen and phosphorous limiting conditions

    PubMed Central

    Nguyen, Giao N.; Rothstein, Steven J.; Spangenberg, German; Kant, Surya

    2015-01-01

    Plant microRNAs (miRNAs) are a class of small non-coding RNAs which target and regulate the expression of genes involved in several growth, development, and metabolism processes. Recent researches have shown involvement of miRNAs in the regulation of uptake and utilization of nitrogen (N) and phosphorus (P) and more importantly for plant adaptation to N and P limitation conditions by modifications in plant growth, phenology, and architecture and production of secondary metabolites. Developing strategies that allow for the higher efficiency of using both N and P fertilizers in crop production is important for economic and environmental benefits. Improved crop varieties with better adaptation to N and P limiting conditions could be a key approach to achieve this effectively. Furthermore, understanding on the interactions between N and P uptake and use and their regulation is important for the maintenance of nutrient homeostasis in plants. This review describes the possible functions of different miRNAs and their cross-talk relevant to the plant adaptive responses to N and P limiting conditions. In addition, a comprehensive understanding of these processes at molecular level and importance of biological adaptation for improved N and P use efficiency is discussed. PMID:26322069

  4. Postural stability limits in manifest and premanifest Huntington's disease under different sensory conditions.

    PubMed

    Blanchet, M; Prince, F; Chouinard, S; Messier, J

    2014-10-24

    Increasing evidence indicates that Huntington's disease (HD) produces postural control impairments even before the clinical diagnosis. It has been suggested that postural disorders of HD patients are explained by deficits in the processing and integration of sensory information, but this hypothesis has been under-explored. In the present study, we evaluated the amplitude of the center of pressure (COP) displacement during maximum leaning in four directions (forward, backward, rightward and leftward) and under three sensory conditions (eyes open, eyes closed and eyes closed standing on foam). We assessed the stability limits in 20 individuals with a positive HD genetic test (12 premanifests; eight manifests HD) and 15 healthy controls. The COP displacements were analyzed during the first and second phases of maintenance of the maximum leaning position. Manifest HD patients showed significantly greater COP ranges than healthy controls in both learning phases and all sensory conditions, but the greatest deterioration of their performance was found in the foam condition. In contrast, premanifest HD patients displayed larger COP ranges than controls only during the second phase of maximum learning, especially in the foam condition. Furthermore, both HD groups had significantly smaller limits of stability than healthy subjects during the second phase of maximum learning. However, their ability to maintain the maximum leaning position was degraded during both learning phases. Together, these findings demonstrate that HD reduces the limits of stability even before the clinical disease onset. Furthermore, our results indicate that dynamic postural tasks with high demand for sensorimotor integration and especially the use of proprioception are highly sensitive to early HD disease processes. This dynamic postural task may become a useful biomarker of HD progression. PMID:25168735

  5. Identification of siderophore biosynthesis genes essential for growth of Aeromonas salmonicida under iron limitation conditions.

    PubMed

    Najimi, Mohsen; Lemos, Manuel L; Osorio, Carlos R

    2008-04-01

    Aeromonas salmonicida subsp. salmonicida, the etiological agent of furunculosis in fish, produces a catechol-type siderophore under iron-limiting conditions. In this study, the Fur titration assay (FURTA) was used to identify a cluster of six genes, asbG, asbF, asbD, asbC, asbB, and asbI, encoding proteins similar to components of the siderophore biosynthetic machinery in other bacteria. Reverse transcriptase PCR analyses showed that this cluster consists of four iron-regulated transcriptional units. Mutants with deletions in either asbD (encoding a multidomain nonribosomal peptide synthetase), asbG (encoding a histidine decarboxylase), or asbC (encoding a predicted histamine monooxygenase) did not grow under iron-limiting conditions and did not produce siderophores. Growth of the DeltaasbG strain under iron starvation conditions was restored by addition of histamine, suggesting that the siderophore in this species could contain a histamine-derived moiety. None of the mutants could grow in the presence of transferrin, indicating that A. salmonicida uses the catechol-type siderophore for removal of iron from transferrin rather than relying on a receptor for this iron-binding protein. All 18 A. salmonicida strains analyzed by DNA probe hybridization were positive in tests for the presence of the asbD gene, and all of them promoted the growth of asbD, asbG, and asbC mutants, suggesting that this siderophore-mediated iron uptake system is conserved among A. salmonicida isolates. This study provides the first description of siderophore biosynthesis genes in this fish pathogen, and the results demonstrate that the asbD, asbG, and asbC genes are necessary for the production of a catecholate siderophore that is essential for the growth of A. salmonicida under iron limitation conditions. PMID:18296539

  6. Courant-like conditions limit reasonable mesh refinement to order h/sup 2/

    SciTech Connect

    Swartz, B.

    1987-11-01

    Under conditions (e.g., Courant-Friedrichs-Lewy conditions) on the size of all location time steps-namely, that they be proportional to the local spatial mesh size - a mesh refinement algorithm cannot be a ''reasonable'' algorithm if, near some space-time surface, the spatial mesh is refined to size o(h/sup 2/), i.e., smaller than order h/sup 2/. Here h typifies the mesh size over most of the spatial region; and an algorithm is called ''unreasonable'' if, asymptotically, it spends all of its computational work exercising at the space-time surface. The limitation is even more stringent for problems with more than one spatial dimension unless the refinement occurs only normal to the surface. As the local time step constraints may be imposed for reasons of accuracy or efficiency as well as for stability, they may differ, on the coarse or fine meshes, from Courant-like conditions. In that case, the limitations on the order of reasonable refinement will generally change. But there is an absolute limitation which depends on the time step restriction away from the surface and on the number of spatial dimensions. One consequence of all this appears to be that o(h/sup 4/) errors are unattainable in vast regions of space-time utilizing reasonable mesh refinement - at least when using more or less uniformly applied difference schemes, with Courant-like conditions, to approximate those solutions of hyperbolic systems whose first derivatives or values jump at some surface in space-time.

  7. Leisure Engagement: Medical Conditions, Mobility Difficulties, and Activity Limitations—A Later Life Perspective

    PubMed Central

    Nilsson, Ingeborg; Nyqvist, Fredrica; Gustafson, Yngve; Nygård, Mikael

    2015-01-01

    Objectives. This study aims to investigate the impact of medical conditions, mobility difficulties, and activity limitations on older people's engagement in leisure activities. Methods. The analyses are based on a cross regional survey carried out in 2010 in the Bothnia region (Northern Sweden and Western Finland). A posted questionnaire, which included questions on different aspects of leisure engagement, medical history, and health, was sent out to older persons in the region. The final sample consisted of 5435 persons aged 65, 70, 75, and 80 years. The data was analyzed by using ordinary least squares (OLS) multivariate regression. Results. The most important predictor of leisure engagement abstention among older people is the prevalence of activity limitations, whereas mobility difficulties and medical conditions play less important roles. The strong negative association between activity limitations and leisure engagement remains significant even after we control for individual, sociodemographic characteristics, and country. Discussion. This study provides a window into leisure engagement in later life and factors influencing the magnitude of engagement in leisure activities. PMID:26346706

  8. Leisure Engagement: Medical Conditions, Mobility Difficulties, and Activity Limitations-A Later Life Perspective.

    PubMed

    Nilsson, Ingeborg; Nyqvist, Fredrica; Gustafson, Yngve; Nygård, Mikael

    2015-01-01

    Objectives. This study aims to investigate the impact of medical conditions, mobility difficulties, and activity limitations on older people's engagement in leisure activities. Methods. The analyses are based on a cross regional survey carried out in 2010 in the Bothnia region (Northern Sweden and Western Finland). A posted questionnaire, which included questions on different aspects of leisure engagement, medical history, and health, was sent out to older persons in the region. The final sample consisted of 5435 persons aged 65, 70, 75, and 80 years. The data was analyzed by using ordinary least squares (OLS) multivariate regression. Results. The most important predictor of leisure engagement abstention among older people is the prevalence of activity limitations, whereas mobility difficulties and medical conditions play less important roles. The strong negative association between activity limitations and leisure engagement remains significant even after we control for individual, sociodemographic characteristics, and country. Discussion. This study provides a window into leisure engagement in later life and factors influencing the magnitude of engagement in leisure activities. PMID:26346706

  9. Can the evolution of plant defense lead to plant-herbivore mutualism?

    PubMed

    de Mazancourt, C; Loreau, M; Dieckmann, U

    2001-08-01

    Moderate rates of herbivory can enhance primary production. This hypothesis has led to a controversy as to whether such positive effects can result in mutualistic interactions between plants and herbivores. We present a model for the ecology and evolution of plant-herbivore systems to address this question. In this model, herbivores have a positive indirect effect on plants through recycling of a limiting nutrient. Plants can evolve but are constrained by a trade-off between growth and antiherbivore defense. Although evolution generally does not lead to optimal plant performance, our evolutionary analysis shows that, under certain conditions, the plant-herbivore interaction can be considered mutualistic. This requires in particular that herbivores efficiently recycle nutrients and that plant reproduction be positively correlated with primary production. We emphasize that two different definitions of mutualism need to be distinguished. A first ecological definition of mutualism is based on the short-term response of plants to herbivore removal, whereas a second evolutionary definition rests on the long-term response of plants to herbivore removal, allowing plants to adapt to the absence of herbivores. The conditions for an evolutionary mutualism are more stringent than those for an ecological mutualism. A particularly counterintuitive result is that higher herbivore recycling efficiency results both in increased plant benefits and in the evolution of increased plant defense. Thus, antagonistic evolution occurs within a mutualistic interaction. PMID:18707340

  10. Hyperbolic divergence cleaning, the electrostatic limit, and potential boundary conditions for particle-in-cell codes

    NASA Astrophysics Data System (ADS)

    Pfeiffer, M.; Munz, C.-D.; Fasoulas, S.

    2015-08-01

    In a numerical solution of the Maxwell-Vlasov system, the consistency with the charge conservation and divergence conditions has to be kept solving the hyperbolic evolution equations of the Maxwell system, since the vector identity ? ? (? × u ?) = 0 and/or the charge conservation of moving particles may be not satisfied completely due to discretization errors. One possible method to force the consistency is the hyperbolic divergence cleaning. This hyperbolic constraint formulation of Maxwell's equations has been proposed previously, coupling the divergence conditions to the hyperbolic evolution equations, which can then be treated with the same numerical method. We pick up this method again and show that electrostatic limit may be obtained by accentuating the divergence cleaning sub-system and converging to steady state. Hence, the electrostatic case can be treated by the electrodynamic code with reduced computational effort. In addition, potential boundary conditions as often given in practical applications can be coupled in a similar way to get appropriate boundary conditions for the field equations. Numerical results are shown for an electric dipole, a parallel-plate capacitor, and a Langmuir wave. The use of potential boundary conditions is demonstrated in an Einzel lens simulation.

  11. Limiting conditions of the horizontal transmission of the Drosophila C virus in its host ( D. melanogaster)

    NASA Astrophysics Data System (ADS)

    Gomariz-Zilber, Eliane; Jeune, Bernard; Thomas-Orillard, Michèle

    1998-04-01

    We carried out experiments with virus infected females on the horizontal transmission of Drosophila C virus on artificial culture medium and under controlled conditions. The numerical results made it possible to build up an empirical model. We tested the values of the rearing parameters under nearly natural conditions in boxes containing pieces of rotting apple. A good agreement between observed and estimated values led to the following conclusions: (i) The horizontal transmission of the Drosophila C virus is facilitated via the contamination of the nutritive medium by the cadavers or the feces of virus-infected females (ii) The contamination depends on the richness of viral particles of the contaminating flies. We also confirmed under 'natural' conditions the insufficient contamination of the male flies which justifies the use of females as 'reservoirs' of the virus. The estimation of the biological limiting conditions for horizontal transfer of the virus is the following: a minimum of two contaminating females have to stay for at least two days on an initially uninfected milieu so that a durable contamination of at least some females results. Under these conditions, the richness in viral particles in the contaminated flies is lower than that in the contaminating females and therefore the long term virus infection remains problematical.

  12. Liquid Lithium Limiter for Carbon Wall Conditioning on RFX-mod

    NASA Astrophysics Data System (ADS)

    Cavazzana, R.; Scarin, P.; Spizzo, G.; Agostini, M.; de Masi, G.; Marrelli, L.; Puiatti, M. E.; Mazzitelli, G.

    2012-10-01

    The Liquid Lithium Limiter (Li3) with capillary porous system originally developed for the FTU tokamak, has been tested for the first time on the Reversed Field Pinch RFX-mod, a machine equipped with a first wall completely covered by graphite tiles. The operation in limiter configuration was restricted by a defect on the limiter, which coupled with the plasma wall interaction with a relatively limited power (2-3 MW/m^2) caused a damage to the device. The Li3 has then been operated as an evaporator, being the Lithium depositions preceded by prolonged glow discharges in Helium to remove the Hydrogen trapped into the graphite. The enhanced retention capability and the lowered recycling factor of the first wall obtained with this treatments in respect to standard operational conditions, allowed a good degree of control on the density of the RFP discharges and to reach high density regimes at high current (n/nGreenwald ˜ 0.8 at plasma current ˜ 1.6 MA).

  13. Entropy rate estimates from mutual information

    NASA Astrophysics Data System (ADS)

    Wissman, B. D.; McKay-Jones, L. C.; Binder, P.-M.

    2011-10-01

    We show how to estimate the Kolmogorov-Sinai entropy rate for chaotic systems using the mutual information function, easily obtainable from experimental time series. We state the conditions under which the relationship is exact, and explore the usefulness of the approach for both maps and flows. We also explore refinements of the method, and study its convergence properties as a function of time series length.

  14. Exploring the limits and utility of operant conditioning in the treatment of drug addiction

    PubMed Central

    Silverman, Kenneth

    2004-01-01

    This article describes a research program to develop an operant treatment for cocaine addiction in low-income, treatment-resistant methadone patients. The treatment's central feature is an abstinence reinforcement contingency in which patients earn monetary reinforcement for providing cocaine-free urine samples. Success and failure of this contingency appear to be an orderly function of familiar parameters of operant conditioning. Increasing reinforcement magnitude and duration can increase effectiveness, and sustaining the contingency can prevent relapse. Initial development of a potentially practical application of this technology suggests that it may be possible to integrate abstinence reinforcement into employment settings using salary for work to reinforce drug abstinence. This research illustrates the potential utility and current limitations of an operant approach to the treatment of drug addiction. Similar research programs are needed to explore the limits of the operant approach and to develop practical applications that can be used widely in society for the treatment of drug addiction. PMID:22478430

  15. Universal limiting shape of worn profile under multiple-mode fretting conditions: theory and experimental evidence.

    PubMed

    Dmitriev, Andrey I; Voll, Lars B; Psakhie, Sergey G; Popov, Valentin L

    2016-01-01

    We consider multiple-mode fretting wear in a frictional contact of elastic bodies subjected to a small-amplitude oscillation, which may include in-plane and out-of-plane translation, torsion and tilting ("periodic rolling"). While the detailed kinetics of wear depends on the particular loading history and wear mechanism, the final worn shape, under some additional conditions, occurs to be universal for all types and loading and wear mechanisms. This universal form is determined solely by the radius of the permanent stick region and the maximum indentation depth during the loading cycle. We provide experimental evidence for the correctness of the theoretically predicted limiting shape. The existence of the universal limiting shape can be used for designing joints which are resistant to fretting wear. PMID:26979092

  16. Universal limiting shape of worn profile under multiple-mode fretting conditions: theory and experimental evidence

    PubMed Central

    Dmitriev, Andrey I.; Voll, Lars B.; Psakhie, Sergey G.; Popov, Valentin L.

    2016-01-01

    We consider multiple-mode fretting wear in a frictional contact of elastic bodies subjected to a small-amplitude oscillation, which may include in-plane and out-of-plane translation, torsion and tilting (“periodic rolling”). While the detailed kinetics of wear depends on the particular loading history and wear mechanism, the final worn shape, under some additional conditions, occurs to be universal for all types and loading and wear mechanisms. This universal form is determined solely by the radius of the permanent stick region and the maximum indentation depth during the loading cycle. We provide experimental evidence for the correctness of the theoretically predicted limiting shape. The existence of the universal limiting shape can be used for designing joints which are resistant to fretting wear. PMID:26979092

  17. The Agony of Choice: How Plants Balance Growth and Survival under Water-Limiting Conditions1

    PubMed Central

    Claeys, Hannes; Inzé, Dirk

    2013-01-01

    When confronted with water limitation, plants actively reprogram their metabolism and growth. Recently, it has become clear that growing tissues show specific and highly dynamic responses to drought, which differ from the well-studied responses in mature tissues. Here, we provide an overview of recent advances in understanding shoot growth regulation in water-limiting conditions. Of special interest is the balance between maintained growth and competitiveness on the one hand and ensured survival on the other hand. A number of master regulators controlling this balance have been identified, such as DELLAs and APETALA2/ETHYLENE RESPONSE FACTOR-type transcription factors. The possibilities of engineering or breeding crops that maintain growth in periods of mild drought, while still being able to activate protective tolerance mechanisms, are discussed. PMID:23766368

  18. Calcification and photosynthesis of the coral acropora cervicornis under calcium limited conditions

    NASA Technical Reports Server (NTRS)

    Rathfon, Megan; Brewer, Debbie

    1997-01-01

    Differing hypothesis about the function of calcification are based on an interesting dilemma. Is the purpose of calcification mainly a structural and protective one or does calcification serve other functions? Does photosynthesis increase carbonate ion activity and cause calcification or does calcification increase CO2 levels and stimulate photsynthesis? It is proposed that calcification in corals is not dependent upon photosynthesis but upon calcium levels in the water. Under normal ocean conditions, corals convert a certain percentage of energy to photosynthesis and respiration and another percentage to calcification. As corals become nutrient stressed, particularly calcium limited, the ratio of photosynthesis to calcification shifts towards calcification in order to generate protons. The protons generated during calcification may stimulate photosynthesis and aid in the uptake of nutrients and biocarbonates. The results of the calcification experiment show a trend towards increased calcification and decreased photosynthesis when the coral Acropora cervicornis is calcium limited, but the data are inconclusive and further research is needed.

  19. Grief and Palliative Care: Mutuality

    PubMed Central

    Moon, Paul J

    2013-01-01

    Grief and palliative care are interrelated and perhaps mutually inclusive. Conceptually and practically, grief intimately relates to palliative care, as both domains regard the phenomena of loss, suffering, and a desire for abatement of pain burden. Moreover, the notions of palliative care and grief may be construed as being mutually inclusive in terms of one cueing the other. As such, the discussions in this article will center on the conceptualizations of the mutuality between grief and palliative care related to end-of-life circumstances. Specifically, the complementarity of grief and palliative care, as well as a controvertible view thereof, will be considered. PMID:25278758

  20. A necessary condition for applying MUSIC algorithm in limited-view inverse scattering problem

    NASA Astrophysics Data System (ADS)

    Park, Taehoon; Park, Won-Kwang

    2015-09-01

    Throughout various results of numerical simulations, it is well-known that MUltiple SIgnal Classification (MUSIC) algorithm can be applied in the limited-view inverse scattering problems. However, the application is somehow heuristic. In this contribution, we identify a necessary condition of MUSIC for imaging of collection of small, perfectly conducting cracks. This is based on the fact that MUSIC imaging functional can be represented as an infinite series of Bessel function of integer order of the first kind. Numerical experiments from noisy synthetic data supports our investigation.

  1. On eddy accumulation with limited conditional sampling to measure air-surface exchange

    SciTech Connect

    Wesely, M.L.; Hart, R.L.

    1994-01-01

    An analysis of turbulence data collected at a height of 12.3 m above grasslands was carried out to illustrate some of the limitations and possible improvements in methods to compute vertical fluxes of trace substances by the eddy accumulation technique with conditional sampling. The empirical coefficient used in the technique has a slight dependence on atmospheric stability, which can be minimized by using a threshold vertical velocity equal to approximately 0.75{sigma}{sub w}, below which chemical sampling is suspended. This protocol results in a smaller chemical sample but increases the differences in concentrations by approximately 70%. For effective conditional sampling when mass is being accumulated in a trap or reservoir, the time of sampling during updrafts versus downdrafts should be measured and used to adjust estimates of the mean concentrations.

  2. A vegetation sensitivity approximation for gross primary production in water limited conditions.

    NASA Astrophysics Data System (ADS)

    Claesson, Jonas; Nycander, Jonas

    2013-04-01

    The most severe impact of climate change on vegetation growth and agriculture is likely to occur under water-limited conditions. Under such conditions the plants optimize the inward flux of CO2 and the outward flux of water vapor (the transpiration) by regulating the size of the stomata openings. Higher temperature increases water loss through transpiration, forcing the plants to diminish the stomata openings, which decreases photosynthesis. This is counteracted by higher CO2 concentration, which allows plants to maintain the inward flux of CO2 through the smaller openings. These two counteracting effects, combined with the change in precipitation, determine the net change of biological productivity in a changed climate. Here, a vegetation sensitivity approximation (VSA) is introduced, in order to understand and estimate the combined effect of changed temperature, CO2-concentration and precipitation on gross primary production (GPP) to first order. According to the VSA, we have: ( ) ?CO2atm ? GP P = ?0 P Here ?CO2atm is the atmospheric CO2 concentration, ?0 is the baseline for atmospheric CO2 concentration, P is precipitation and ? is defined by: -s- ? = 1 - 11°C where s is the climate sensitivity i.e. the increase in temperature when atmospheric CO2 is doubled. The VSA is based on the physical laws of gas flux through the stomata openings, and is only valid under water-limited conditions. It assumes that the temperature depends logarithmically on the CO2 concentration with a given climate sensitivity. Transpiration is assumed to be a constant fraction of precipitation, which is reasonable under water-limited conditions. The VSA is compared to simulations with the dynamic vegetation model LPJ. The agreement is reasonable, and the deviations can be understood by comparison with Köppen's definition of arid climate: in an arid climate growth increases more according to LPJ than according to the VSA, and in non-arid conditions the reverse is true. Both the VSA and the LPJ simulations generally show increased growth with increasing CO2 levels and the resulting temperature increase, assuming precipitation to be unchanged. Thus, for constant precipitation the negative temperature effect is more than compensated by the positive effect of CO2.

  3. PREDICTOL: a computer program to determine the thermophysiological duration limited exposures in various climatic conditions.

    PubMed

    Besnard, Yves; Launay, Jean-Claude; Guinet-Lebreton, Angélique; Savourey, Gustave

    2004-12-01

    PREDICTOL is a PC program used to determine the thermophysiological duration limited exposures (DLE) in humans, nude or clothed, submitted to various climatic conditions (hot and cold climates) at rest or during a physical exercise. DLE are determined following different standards of the International Standardization Organization (ISO), especially ISO 7933 for hot environment and ISO-TR 11079 for cold environment. The original aspect of this program is that it can be used whatever the climatic conditions. The program presents two modes: an educational interactive mode and a scenario mode. The educational interactive mode demonstrates the thermophysiological effects, expressed as DLE, of different parameter changes (temperature, humidity, wind speed, metabolic heat production by physical exercise, clothing insulation and water vapor permeability). The scenario mode determines DLE for given various linked sequences as encountered in occupational, military or even recreational activities, each sequence being characterized by its climatic conditions, physical activities performed and by physical clothing properties. DLE given by PREDICTOL are correlated to those obtained in various controlled climatic laboratory conditions (r = 0.86; P < 0.001). PREDICTOL is written in Visual Basic 6.0. A "help menu" is provided to explain the use of the program and give information concerning the equations used to calculate both the thermal balance and DLE. PMID:15501508

  4. Assessment of bacterial community structure in nitrifying biofilm under inorganic carbon-sufficient and -limited conditions.

    PubMed

    Bae, Hyokwan; Chung, Yun-Chul; Yang, Heejeong; Lee, Changsoo; Aryapratama, Rio; Yoo, Young J; Lee, Seockheon

    2015-01-01

    In this work, nitrification and changes in the composition of the total bacterial community under inorganic carbon (IC)-limited conditions, in a nitrifying moving bed biofilm reactor, was investigated. A culture-independent analysis of cloning and sequencing based on the 16S rRNA gene was applied to quantify the bacterial diversity and to determine bacterial taxonomic assignment. IC concentrations had significant effects on the stability of ammonia-oxidation as indicated by the reduction of the nitrogen conversion rate with high NH4(+)-N loadings. The predominance of Nitrosomonas europaea was maintained in spite of changes in the IC concentration. In contrast, heterotrophic bacterial species contributed to a high bacterial diversity, and to a dynamic shift in the bacterial community structure, under IC-limited conditions. In this study, individual functions of heterotrophic bacteria were estimated based on taxonomic information. Possible key roles of coexisting heterotrophic bacteria are the assimilation of organic compounds of extracellular polymeric substances produced by nitrifiers, and biofilm formation by providing a filamentous structure and aggregation properties. PMID:25560266

  5. Mutual Mentoring Makes Better Mentors

    NASA Astrophysics Data System (ADS)

    Blaha, Cindy; Bug, Amy; Cox, Anne; Fritz, Linda; Whitten, Barbara

    2011-03-01

    In this talk we discuss one of the impacts of an NSF ADVANCE sponsored horizontal, mutual mentoring alliance. Our cohort of five women physicists at liberal arts colleges has found that mutual mentoring has had a profound impact on many aspects of our professional lives. In this talk we will describe how our peer-to-peer mentoring has enabled us to become better mentors for our undergraduate students, for recent graduates beginning their careers and for colleagues at local and neighboring institutions.

  6. Different resource limitation by carbon, nitrogen and phosphorus between base flow and high flow conditions for estuarine bacteria and phytoplankton

    NASA Astrophysics Data System (ADS)

    Hitchcock, James N.; Mitrovic, Simon M.

    2013-12-01

    Freshwater inflows can deliver substantial inputs of allochthonous organic carbon to estuaries. The role that allochthonous DOC has on structuring bacterial and phytoplankton communities is still not well understood. We performed a series of 1.25 L bioassay limitation experiments on the Bega and Clyde River estuaries in NSW, Australia, examining what resources limit bacteria and phytoplankton growth. We hypothesized that during base flow conditions bacteria would be carbon limited, and after high flow conditions they would be nutrient limited. A full factorial design was used with additions of carbon (glucose), nitrogen (KNO3) and phosphorus (KH2PO4). During the experiments that took place during base flow conditions bacteria were always primarily C-limited. After high flow conditions, bacteria were P-limited on the Clyde River, and remained C-limited on the Bega River. Phytoplankton growth was limited at all times in each estuary, tending toward N-limitation on the Bega River and P-limitation on the Clyde river. During high flow conditions on the Clyde River, when bacteria and phytoplankton were both primarily P-limited, it appeared that bacteria was able to outcompete phytoplankton for nutrients. These results suggest that freshwater inflows and allochthonous DOC maybe important in structuring estuarine microbial ecosystems and individual estuaries may behave differently in terms of their limiting resources.

  7. Oceanographic Conditions Limit the Spread of a Marine Invader along Southern African Shores.

    PubMed

    Assis, Jorge; Zupan, Mirta; Nicastro, Katy R; Zardi, Gerardo I; McQuaid, Christopher D; Serrão, Ester A

    2015-01-01

    Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role. PMID:26114766

  8. Oceanographic Conditions Limit the Spread of a Marine Invader along Southern African Shores

    PubMed Central

    Nicastro, Katy R.; Zardi, Gerardo I.; McQuaid, Christopher D.; Serrão, Ester A.

    2015-01-01

    Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role. PMID:26114766

  9. Optimization of plant mineral nutrition under growth-limiting conditions in a lunar greenhouse

    NASA Astrophysics Data System (ADS)

    Zaets, I.; Voznyuk, T.; Kovalchuk, M.; Rogutskyy, I.; Lukashov, D.; Mytrokhyn, O.; Mashkovska, S.; Foing, B.; Kozyrovska, N.

    It may be assumed that the first plants in a lunar base will play a main role in forming a protosoil of acceptable fertility needed for purposively growing second generation plants like wheat, rice, tulips, etc. The residues of the first-generation plants could be composted and transformed by microorganisms into a soil-like substrate within a loop of regenerative life support system. The lunar regolith may be used as a substrate for plant growth at the very beginning of a mission to reduce its cost. The use of microbial communities for priming plants will allow one to facilitate adaption to stressful conditions and to support the plant development under growth limiting conditions. Well-defined plant-associated bacteria were used for growing three cultivars to colonize French marigold (Tagetes patula L.) in anorthosite, a substrate of low bioavailability, analogous to a lunar rock. The consortium was composed of plant growth promoting rhizobacteria and the bacterium Paenibacillus sp. IMBG156 which stimulated seed germination, better plant development, and finally, the flowering of inoculated tagetes. In contrast, control plants grew poorly in the anorthosite and practically did not survive until flowering. Analysis of bacterial community composition showed that all species colonized plant roots, however, the rate of colonization depended on the allelopatic characteristics of marigold varieties. Bacteria of consortium were able to liberate some elements (Ca, Fe, Mn, Si, Ni, Cu, Zn) from substrate anorthosite. Plant colonization by mixed culture of bacterial strains resulted in the increase of accumulation of K, Mg, Mn by the plant and in the lowering of the level of toxic metal accumulation. It was assumed that a rationally assembled consortium of bacterial strains promoted germination of marygold seeds and supported the plant development under growth limiting conditions by means of bioleaching plant essential nutritional elements and by protecting the plant against hyperaccumulation of some toxic metals.

  10. Floral resource limitation severely reduces butterfly survival, condition and flight activity in simplified agricultural landscapes.

    PubMed

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans

    2016-02-01

    Agricultural intensification has a strong negative impact on farmland biodiversity (including flower-visiting insects), but understanding the mechanisms involved in this requires experimental work. We document the impact of nectar limitation on the performance of a flower-visiting insect, the meadow brown butterfly Maniola jurtina. We conducted two types of experiments: a field experiment in agricultural landscapes with grasslands of different management intensity and an experiment in outdoor flight cages in which the nectar supply was simulated. For the field experiment, we introduced an array of nectar resources in intensively managed, nectar-poor meadows and in extensively managed, flower-rich grasslands and counted flower visitors. Despite higher butterfly abundance in the extensive meadows, our introduced nectar sources were more frequently visited in intensive meadows, indicating the lack of floral resources. The 48-h confinement under nectar-poor conditions in the flight cages had a strong negative effect on body condition, flight activity and lifetime survival compared to butterflies under nectar-rich conditions. Female lifespan was reduced by 22 % and male lifespan even by 43 %. Agricultural landscapes that provide limited amounts of floral nectar, and no high-quality, preferred nectar sources relative to the needs of the flower-visiting species, may create ecological sinks. Regards an insect's performance, the simple presence of nectar is not necessarily functionally adequate. The effectiveness of agri-environmental schemes for flower-visiting insects (e.g. flower strips) could be improved based on ecological and evolutionary insights on the effects of specific nectar quantities and qualities. PMID:26541442

  11. Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population

    PubMed Central

    Adams, Jennifer R.; Vucetich, Leah M.; Hedrick, Philip W.; Peterson, Rolf O.; Vucetich, John A.

    2011-01-01

    Genetic rescue, in which the introduction of one or more unrelated individuals into an inbred population results in the reduction of detrimental genetic effects and an increase in one or more vital rates, is a potentially important management tool for mitigating adverse effects of inbreeding. We used molecular techniques to document the consequences of a male wolf (Canis lupus) that immigrated, on its own, across Lake Superior ice to the small, inbred wolf population in Isle Royale National Park. The immigrant's fitness so exceeded that of native wolves that within 2.5 generations, he was related to every individual in the population and his ancestry constituted 56 per cent of the population, resulting in a selective sweep of the total genome. In other words, all the male ancestry (50% of the total ancestry) descended from this immigrant, plus 6 per cent owing to the success of some of his inbred offspring. The immigration event occurred in an environment where space was limiting (i.e. packs occupied all available territories) and during a time when environmental conditions had deteriorated (i.e. wolves' prey declined). These conditions probably explain why the immigration event did not obviously improve the population's demography (e.g. increased population numbers or growth rate). Our results show that the beneficial effects of gene flow may be substantial and quickly manifest, short-lived under some circumstances, and how the demographic benefits of genetic rescue might be masked by environmental conditions. PMID:21450731

  12. Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population.

    PubMed

    Adams, Jennifer R; Vucetich, Leah M; Hedrick, Philip W; Peterson, Rolf O; Vucetich, John A

    2011-11-22

    Genetic rescue, in which the introduction of one or more unrelated individuals into an inbred population results in the reduction of detrimental genetic effects and an increase in one or more vital rates, is a potentially important management tool for mitigating adverse effects of inbreeding. We used molecular techniques to document the consequences of a male wolf (Canis lupus) that immigrated, on its own, across Lake Superior ice to the small, inbred wolf population in Isle Royale National Park. The immigrant's fitness so exceeded that of native wolves that within 2.5 generations, he was related to every individual in the population and his ancestry constituted 56 per cent of the population, resulting in a selective sweep of the total genome. In other words, all the male ancestry (50% of the total ancestry) descended from this immigrant, plus 6 per cent owing to the success of some of his inbred offspring. The immigration event occurred in an environment where space was limiting (i.e. packs occupied all available territories) and during a time when environmental conditions had deteriorated (i.e. wolves' prey declined). These conditions probably explain why the immigration event did not obviously improve the population's demography (e.g. increased population numbers or growth rate). Our results show that the beneficial effects of gene flow may be substantial and quickly manifest, short-lived under some circumstances, and how the demographic benefits of genetic rescue might be masked by environmental conditions. PMID:21450731

  13. The Impact of Different Sources of Fluctuations on Mutual Information in Biochemical Networks

    PubMed Central

    Chevalier, Michael; Venturelli, Ophelia; El-Samad, Hana

    2015-01-01

    Stochastic fluctuations in signaling and gene expression limit the ability of cells to sense the state of their environment, transfer this information along cellular pathways, and respond to it with high precision. Mutual information is now often used to quantify the fidelity with which information is transmitted along a cellular pathway. Mutual information calculations from experimental data have mostly generated low values, suggesting that cells might have relatively low signal transmission fidelity. In this work, we demonstrate that mutual information calculations might be artificially lowered by cell-to-cell variability in both initial conditions and slowly fluctuating global factors across the population. We carry out our analysis computationally using a simple signaling pathway and demonstrate that in the presence of slow global fluctuations, every cell might have its own high information transmission capacity but that population averaging underestimates this value. We also construct a simple synthetic transcriptional network and demonstrate using experimental measurements coupled to computational modeling that its operation is dominated by slow global variability, and hence that its mutual information is underestimated by a population averaged calculation. PMID:26484538

  14. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual policies, and mutual fire or flood insurance companies operating on the basis of premium deposits; taxable years beginning after December 31, 1962....

  15. Soil texture and climatc conditions for biocrust growth limitation: a meta analysis

    NASA Astrophysics Data System (ADS)

    Fischer, Thomas; Subbotina, Mariia

    2015-04-01

    Along with afforestation, attempts have been made to combat desertification by managing soil crusts, and is has been reported that recovery rates of biocrusts are dependent on many factors, including the type, severity, and extent of disturbance; structure of the vascular plant community; conditions of adjoining substrates; availability of inoculation material; and climate during and after disturbance (Belnap & Eldridge 2001). Because biological soil crusts are known to be more stable on and to prefer fine substrates (Belnap 2001), the question arises as to how successful crust management practices can be applied to coarser soil. In previous studies we observed similar crust biomasses on finer soils under arid and on coarser soils under temperate conditions. We hypothesized that the higher water holding capacity of finer substrates would favor crust development, and that the amount of silt and clay in the substrate that is required for enhanced crust development would vary with changes in climatic conditions. In a global meta study, climatic and soil texture threshold values promoting BSC growth were derived. While examining literature sources, it became evident that the amount of studies to be incorporated into this meta analysis was reversely related to the amount of common environmental parameters they share. We selected annual mean precipitaion, mean temperature and the amount of silt and clay as driving variables for crust growth. Response variable was the "relative crust biomass", which was computed per literature source as the ratio between each individual crust biomass value of the given study to the study maximum value reported. We distinguished lichen, green algal, cyanobacterial and moss crusts. To quantify threshold conditions at which crust biomass responded to differences in texture and climate, we (I) determined correlations between bioclimatic variables, (II) calculated linear models to determine the effect of typical climatic variables with soil clay content and with study site as a random effect. (III) Threshold values of texture and climatc effects were identified using a regression tree. Three mean annual temperature classes for texture dependent BSC growth limitation were identified: (1) <9 °C with a threshold value of 25% silt and clay (limited growth on coarser soils), (2) 9-19 °C, where texture did have no influence on relative crust biomass, and (3) >19 °C at soils with <4 or >17% silt and clay. Because biocrust development is limited under certain climatic and soil texture conditions, it is suggested to consider soil texture for biocrust rehabilitation purposes and in biogeochemical modeling of cryptogamic ground covers. References Belnap, J. & Eldridge, D. 2001. Disturbance and Recovery of Biological Soil Crusts. In: Belnap, J. & Lange, O. (eds.) Biological Soil Crusts: Structure, Function, and Management, Springer, Berlin. Belnap, J. 2001. Biological Soil Crusts and Wind Erosion. In: Belnap, J. & Lange, O. (eds.) Fischer, T., Subbotina, M. 2014. Climatic and soil texture threshold values for cryptogamic cover development: a meta analysis. Biologia 69/11:1520-1530,

  16. Baclofen, raclopride, and naltrexone differentially affect intake of fat and sucrose under limited access conditions.

    PubMed

    Corwin, Rebecca L; Wojnicki, Francis H

    2009-09-01

    Gamma-aminobutyric acid (GABA), dopamine, and opioids are implicated in impulse control, addiction and binge eating. Recent evidence suggests that sucrose alters the effects of GABAergic, dopaminergic, and opioid receptor ligands on consumption of a fatty food in a rat limited-access binge protocol. This study determined the independent effects of fat and sucrose on the efficacy of these ligands under limited-access conditions. Nonfood-deprived male Sprague-Dawley rats had 1 h access to fat (vegetable shortening) or sucrose (3.2, 10, or 32% w/v). Half had intermittent access (Monday, Wednesday, Friday) and half had daily access. Effects of baclofen (GABAB agonist), SCH 23390 (D1 antagonist), raclopride (D2 antagonist), and naltrexone (opioid antagonist) were assessed. Baclofen and naltrexone reduced fat intake regardless of the access schedule. Baclofen had no effect on sucrose intake; naltrexone reduced sucrose intake at higher doses than were required to reduce fat intake. Raclopride stimulated fat intake in intermittent-access rats and had no effect in daily-access rats; raclopride reduced sucrose intake in all groups. SCH 23390 reduced intake in a nonspecific manner. The results indicate the involvement of GABAB receptors in fat but not sucrose intake, and of D2 receptor dysfunction in rats with a history of bingeing on fat. PMID:19724193

  17. Kitagawa-Takahashi diagrams define the limiting conditions for cyclic fatigue failure in human dentin.

    PubMed

    Kruzic, J J; Ritchie, R O

    2006-12-01

    As cyclic fatigue is considered to be a major cause of clinical tooth fractures, achieving a comprehensive understanding of the fatigue behavior of dentin is of importance. In this note, the fatigue behavior of human dentin is examined in the context of the Kitagawa-Takahashi diagram to define the limiting conditions for fatigue failure. Specifically, this approach incorporates two limiting threshold criteria for fatigue: (i) a threshold stress for fatigue failure, specifically the smooth-bar (unnotched) fatigue endurance strength, at small crack sizes and (ii) a threshold stress-intensity range for fatigue-crack growth at larger crack sizes. The approach provides a "bridge" between the traditional fatigue life and fracture mechanics based damage-tolerant approaches to fatigue-life estimation, and as such defines a "failure envelope" of applied stresses and flaw sizes where fatigue failure is likely in dentin This approach may also be applied to fatigue failure in human cortical bone (i.e. clinical "stress fractures"), which exhibits similar fatigue behavior characteristics, and in principle may aid clinicians in making quantitative evaluations of the risk of fractures in mineralized tissues. PMID:17013865

  18. Beneficial Effects of Nickel on Pseudomonas saccharophila under Nitrogen-Limited Chemolithotrophic Conditions

    PubMed Central

    Barraquio, Wilfredo L.; Knowles, Roger

    1989-01-01

    Addition of nickel stimulated growth and nitrogenase activity of Pseudomonas saccharophila under nitrogen-limited chemolithotrophic conditions, apparently because of a significant increase in expression of uptake hydrogenase activity. Inhibition of hydrogenase expression by 50 μM EDTA was relieved by nickel over a wide concentration range (1 to 200 μM). Co2+, Zn2+, Mn2+, and Cu2+ stimulated expression of hydrogenase activity, but to a much lesser degree than nickel, and Fe2+, Mg2+, SeO42−, and SeO32− did not increase expression. Nickel in individual combination with Mg2+, Fe2+, SeO32−, and SeO42− resulted in activities that were essentially the same as that with nickel alone. Hydrogenase synthesis required the presence of nickel, and repression by O2 was alleviated by increasing the concentration of added nickel. Cells placed under hydrogenase derepression conditions showed progressive incorporation of radioactive nickel to a much greater extent than did cells which were not derepressed. PMID:16348078

  19. Hierarchical clustering using mutual information

    NASA Astrophysics Data System (ADS)

    Kraskov, A.; Stögbauer, H.; Andrzejak, R. G.; Grassberger, P.

    2005-04-01

    We present a conceptually simple method for hierarchical clustering of data called mutual information clustering (MIC) algorithm. It uses mutual information (MI) as a similarity measure and exploits its grouping property: The MI between three objects X, Y, and Z is equal to the sum of the MI between X and Y, plus the MI between Z and the combined object (XY). We use this both in the Shannon (probabilistic) version of information theory and in the Kolmogorov (algorithmic) version. We apply our method to the construction of phylogenetic trees from mitochondrial DNA sequences and to the output of independent components analysis (ICA) as illustrated with the ECG of a pregnant woman.

  20. Parameter identification of the SWAT model on the BANI catchment (West Africa) under limited data condition

    NASA Astrophysics Data System (ADS)

    Chaibou Begou, Jamilatou; Jomaa, Seifeddine; Benabdallah, Sihem; Rode, Michael

    2015-04-01

    Due to the climate change, drier conditions have prevailed in West Africa, since the seventies, and the consequences are important on water resources. In order to identify and implement management strategies of adaptation to climate change in the sector of water, it is crucial to improve our physical understanding of water resources evolution in the region. To this end, hydrologic modelling is an appropriate tool for flow predictions under changing climate and land use conditions. In this study, the applicability and performance of the recent version of Soil and Water Assessment Tool (SWAT2012) model were tested on the Bani catchment in West Africa under limited data condition. Model parameters identification was also tested using one site and multisite calibration approaches. The Bani is located in the upper part of the Niger River and drains an area of about 101, 000 km2 at the outlet of Douna. The climate is tropical, humid to semi-arid from the South to the North with an average annual rainfall of 1050 mm (period 1981-2000). Global datasets were used for the model setup such as: USGS hydrosheds DEM, USGS LCI GlobCov2009 and the FAO Digital Soil Map of the World. Daily measured rainfall from nine rain gauges and maximum and minimum temperature from five weather stations covering the period 1981-1997 were used for model setup. Sensitivity analysis, calibration and validation are performed within SWATCUP using GLUE procedure at Douna station first (one site calibration), then at three additional internal stations, Bougouni, Pankourou and Kouoro1 (multi-site calibration). Model parameters were calibrated at daily time step for the period 1983-1992, then validated for the period 1993-1997. A period of two years (1981-1982) was used for model warming up. Results of one-site calibration showed that the model performance is evaluated by 0.76 and 0.79 for Nash-Sutcliffe (NS) and correlation coefficient (R2), respectively. While for the validation period the performance improved considerably with NS and R2 equal to 0.84 and 0.87, respectively. The degree of total uncertainties is quantified by a minimum P-factor of 0.61 and a maximum R-factor of 0.59. These statistics suggest that the model performance can be judged as very good, especially considering limited data condition and high climate, land use and soil variability in the studied basin. The most sensitive parameters (CN2, OVN and SLSUBBSN) are related to surface runoff reflecting the dominance of this process on the streamflow generation. In the next step, multisite calibration approach will be performed on the BANI basin to assess how much additional observations improve the model parameter identification.

  1. Phytoplankton copper requirement under iron limited condition in the coastal Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Biswas, H.; Bandyopadhyay, D.; Kumar, P. P.

    2012-04-01

    Copper, a redox reactive transition metal, plays a vital role in many cellular redox reactions. Recent investigations show that many eukaryotic microorganisms including marine and coastal diatom utilize copper to perform a high affinity iron acquisition mechanism and the requirement of copper increases with decreasing iron concentrations. However, very less information is available about the role of copper in diatom physiology. Here we report for the first time about the copper utilization by coastal diatom during iron limited condition in the Bay of Bengal coast. The diatom Chaetoceros gracilis was isolated from the Visakhapatnam coast and was grown in different copper concentrations (15nM -1000nM). The concentration of total chlorophyll, the growth rate, the concentration of biogenic silica, the ratio of biogenic silica to particulate organic carbon and the ratio of total chlorophyll to particulate organic carbon were found to be increased with increasing copper concentration up to 125nM and decreased thereafter reaching a minimum value at 1000nM. 13C of Particulate organic carbon varied inversely with increasing copper concentrations indicating the signature of enhanced carbon fixation which is in agreement with the enhanced biomass and growth rate. However, to get a better understanding about the role of copper behind the enhanced growth, we had incubated the cells simultaneously in iron replete, copper replete and in varying copper concentration in presence of 200nM of iron. Surprisingly, in all cases significant enhancement in growth and biomass production was observed. The cells grown in only iron and added with copper showed very similar increase whereas, in presence of iron increasing copper concentration did not show any enhancement effect. Increased growth and biomass production in response to iron addition shows that phytoplankton growth is limited by iron in the study area. Furthermore, this observation indicates that in case of iron limitation the coastal diatom perform a high affinity iron acquisition mechanism where copper plays a vital role. Down regulation of high affinity iron acquisition mechanism was indicated by unaltered growth when copper was added in presence of iron. Collectively, our present study shows that copper likely plays an important role in the physiology of coastal diatom apart from the toxicological studies conducted earlier. A detailed investigation is needed to understand the high affinity iron acquisition mechanism existing in coastal diatom from the study area.

  2. Performance of Airborne Precision Spacing Under Realistic Wind Conditions and Limited Surveillance Range

    NASA Technical Reports Server (NTRS)

    Wieland, Frederick; Santos, Michel; Krueger, William; Houston, Vincent E.

    2011-01-01

    With the expected worldwide increase of air traffic during the coming decade, both the Federal Aviation Administration's (FAA's) Next Generation Air Transportation System (NextGen), as well as Eurocontrol's Single European Sky ATM Research (SESAR) program have, as part of their plans, air traffic management (ATM) solutions that can increase performance without requiring time-consuming and expensive infrastructure changes. One such solution involves the ability of both controllers and flight crews to deliver aircraft to the runway with greater accuracy than they can today. Previous research has shown that time-based spacing techniques, wherein the controller assigns a time spacing to each pair of arriving aircraft, can achieve this goal by providing greater runway delivery accuracy and producing a concomitant increase in system-wide performance. The research described herein focuses on one specific application of time-based spacing, called Airborne Precision Spacing (APS), which has evolved over the past ten years. This research furthers APS understanding by studying its performance with realistic wind conditions obtained from atmospheric sounding data and with realistic wind forecasts obtained from the Rapid Update Cycle (RUC) short-range weather forecast. In addition, this study investigates APS performance with limited surveillance range, as provided by the Automatic Dependent Surveillance-Broadcast (ADS-B) system, and with an algorithm designed to improve APS performance when ADS-B surveillance data is unavailable. The results presented herein quantify the runway threshold delivery accuracy of APS under these conditions, and also quantify resulting workload metrics such as the number of speed changes required to maintain spacing.

  3. Do water-limiting conditions predispose Norway spruce to bark beetle attack?

    PubMed Central

    Netherer, Sigrid; Matthews, Bradley; Katzensteiner, Klaus; Blackwell, Emma; Henschke, Patrick; Hietz, Peter; Pennerstorfer, Josef; Rosner, Sabine; Kikuta, Silvia; Schume, Helmut; Schopf, Axel

    2015-01-01

    Drought is considered to enhance susceptibility of Norway spruce (Picea abies) to infestations by the Eurasian spruce bark beetle (Ips typographus, Coleoptera: Curculionidae), although empirical evidence is scarce. We studied the impact of experimentally induced drought on tree water status and constitutive resin flow, and how physiological stress affects host acceptance and resistance. We established rain-out shelters to induce both severe (two full-cover plots) and moderate (two semi-cover plots) drought stress. In total, 18 sample trees, which were divided equally between the above treatment plots and two control plots, were investigated. Infestation was controlled experimentally using a novel ‘attack box’ method. Treatments influenced the ratios of successful and defended attacks, but predisposition of trees to infestation appeared to be mainly driven by variations in stress status of the individual trees over time. With increasingly negative twig water potentials and decreasing resin exudation, the defence capability of the spruce trees decreased. We provide empirical evidence that water-limiting conditions impair Norway spruce resistance to bark beetle attack. Yet, at the same time our data point to reduced host acceptance byI. typographus with more extreme drought stress, indicated by strongly negative pre-dawn twig water potentials. PMID:25417785

  4. Bioconversion of crude glycerol to polyhydroxyalkanoate by Bacillus thuringiensis under non-limiting nitrogen conditions.

    PubMed

    Kumar, Prasun; Ray, Subhasree; Patel, Sanjay K S; Lee, Jung-Kul; Kalia, Vipin C

    2015-01-01

    Glycerol has emerged as a cheap waste material due to blooming biodiesel manufacturing units worldwide. The need is to exploit the crude glycerol (CG) to produce useful products such as polyhydroxyalkanoate (PHA). Bacillus thuringiensis EGU45 was found to produce 1.5-3.5 gP HA L(-1) from feed containing 1-10% CG (vv(-1)) and nutrient broth (NB, 125 mL) without any acclimatization. B. thuringiensis EGU45 could produce PHA at the rate of 1.54-1.83 g L(-1), from 1% CG (vv(-1)) on media having high nitrogen contents: (i) NB, (ii) NB+0.5% NH4Cl (wv(-1)), and (iii) peptone+yeast extract+0.5% NH4Cl (wv(-1)). B. thuringiensis EGU45 was able to produce co-polymer of P(3HB-co-3HV) with 13.4% 3HV content on high N containing feed supplemented with propionic acid. This is the first report demonstrating the abilities of B. thuringiensis to convert CG into PHA co-polymer under non-limiting N conditions. PMID:25840150

  5. Application of Forming Limit Criteria Based on Plastic Instability Condition to Metal Forming Process

    NASA Astrophysics Data System (ADS)

    Heo, Seong-Chan; Ku, Tae-Wan; Kim, Jeong; Kang, Beom-Soo; Song, Woo-Jin

    Metal forming processes such as hydroforming and sheet metal forming using tubular material and thin sheet metal have been widely used in lots of industrial fields for manufacturing of various parts that could be equipped with mechanical products. However, it is not easy to design sequential processes properly because there are various design variables that affect formability of the parts. Therefore preliminary evaluation of formability for the given process should be carried out to minimize time consumption and development cost. With the advances in finite element analysis technique over the decades, the formability evaluation using numerical simulation has been conducted in view of strain distribution and final shape. In this paper, the application of forming limit criteria is carried out for the tube hydroforming and sheet metal forming processes using theoretical background based on plastic instability conditions. Consequently, it is confirmed that the local necking and diffuse necking criteria of sheet are suitable for formability evaluation of both hydroforming and sheet metal forming processes.

  6. Do water-limiting conditions predispose Norway spruce to bark beetle attack?

    PubMed

    Netherer, Sigrid; Matthews, Bradley; Katzensteiner, Klaus; Blackwell, Emma; Henschke, Patrick; Hietz, Peter; Pennerstorfer, Josef; Rosner, Sabine; Kikuta, Silvia; Schume, Helmut; Schopf, Axel

    2015-02-01

    Drought is considered to enhance susceptibility of Norway spruce (Picea abies) to infestations by the Eurasian spruce bark beetle (Ips typographus, Coleoptera: Curculionidae), although empirical evidence is scarce. We studied the impact of experimentally induced drought on tree water status and constitutive resin flow, and how physiological stress affects host acceptance and resistance. We established rain-out shelters to induce both severe (two full-cover plots) and moderate (two semi-cover plots) drought stress. In total, 18 sample trees, which were divided equally between the above treatment plots and two control plots, were investigated. Infestation was controlled experimentally using a novel 'attack box' method. Treatments influenced the ratios of successful and defended attacks, but predisposition of trees to infestation appeared to be mainly driven by variations in stress status of the individual trees over time. With increasingly negative twig water potentials and decreasing resin exudation, the defence capability of the spruce trees decreased. We provide empirical evidence that water-limiting conditions impair Norway spruce resistance to bark beetle attack. Yet, at the same time our data point to reduced host acceptance by I. typographus with more extreme drought stress, indicated by strongly negative pre-dawn twig water potentials. PMID:25417785

  7. 29 CFR Appendix A to Subpart Y of... - Examples of Conditions Which May Restrict or Limit Exposure to Hyperbaric Conditions

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to Hyperbaric Conditions A Appendix A to Subpart Y of Part 1926 Labor Regulations Relating to Labor... REGULATIONS FOR CONSTRUCTION Diving Pt. 1926, Subpt. Y, App. A Appendix A to Subpart Y of Part 1926—Examples... applicable to construction work under this appendix A are identical to those set forth at appendix A...

  8. Mutual Respect and Civic Education

    ERIC Educational Resources Information Center

    Bird, Colin

    2010-01-01

    Contemporary theories of civic education frequently appeal to an ideal of mutual respect in the context of ethical, ethical and religious disagreement. This paper critically examines two recently popular criticisms of this ideal. The first, coming from a postmodern direction, charges that the ideal is hypocritical in its effort to be maximally…

  9. Multivariate probability distribution for sewer system vulnerability assessment under data-limited conditions.

    PubMed

    Del Giudice, G; Padulano, R; Siciliano, D

    2016-01-01

    The lack of geometrical and hydraulic information about sewer networks often excludes the adoption of in-deep modeling tools to obtain prioritization strategies for funds management. The present paper describes a novel statistical procedure for defining the prioritization scheme for preventive maintenance strategies based on a small sample of failure data collected by the Sewer Office of the Municipality of Naples (IT). Novelty issues involve, among others, considering sewer parameters as continuous statistical variables and accounting for their interdependences. After a statistical analysis of maintenance interventions, the most important available factors affecting the process are selected and their mutual correlations identified. Then, after a Box-Cox transformation of the original variables, a methodology is provided for the evaluation of a vulnerability map of the sewer network by adopting a joint multivariate normal distribution with different parameter sets. The goodness-of-fit is eventually tested for each distribution by means of a multivariate plotting position. The developed methodology is expected to assist municipal engineers in identifying critical sewers, prioritizing sewer inspections in order to fulfill rehabilitation requirements. PMID:26901717

  10. Striving toward Self-Sufficiency: A Qualitative Study of Mutual Aid in an Old Order Mennonite Community

    ERIC Educational Resources Information Center

    Gingrich, Luann Good; Lightman, Ernie

    2006-01-01

    Most contemporary groups limit attempts of mutuality to specific instances of need. This paper reports on a qualitative study of the structures and systems of mutual aid in a traditional, closed ethnoreligious Old Order Mennonite community in Ontario. We examine the structural characteristics, systems of mutuality, tensions, and conflicts that…

  11. Metabolomic Profiling of 13 Diatom Cultures and Their Adaptation to Nitrate-Limited Growth Conditions

    PubMed Central

    Bromke, Mariusz A.; Sabir, Jamal S.; Alfassi, Fahad A.; Hajarah, Nahid H.; Kabli, Saleh A.; Al-Malki, Abdulrahman L.; Ashworth, Matt P.; Méret, Michaël; Jansen, Robert K.; Willmitzer, Lothar

    2015-01-01

    Diatoms are very efficient in their use of available nutrients. Changes in nutrient availability influence the metabolism and the composition of the cell constituents. Since diatoms are valuable candidates to search for oil producing algae, measurements of diatom-produced compounds can be very useful for biotechnology. In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains. With the help of a lipidomics platform, which combines an UPLC separation with a high resolution/high mass accuracy mass spectrometer, we were able to measure and annotate 142 lipid species. Out of these, 32 were present in all 13 cultures. The annotated lipid features belong to six classes of glycerolipids. The data obtained from the measurements were used to create lipidomic profiles. The metabolomic overview of analysed cultures is amended by the measurement of 96 polar compounds. To further increase the lipid diversity and gain insight into metabolomic adaptation to nitrogen limitation, diatoms were cultured in media with high and low concentrations of nitrate. The growth in nitrogen-deplete or nitrogen-replete conditions affects metabolite accumulation but has no major influence on the species-specific metabolomic profile. Thus, the genetic component is stronger in determining metabolic patterns than nitrogen levels. Therefore, lipid profiling is powerful enough to be used as a molecular fingerprint for diatom cultures. Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains. Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock. PMID:26440112

  12. Secreted Pyomelanin of Legionella pneumophila Promotes Bacterial Iron Uptake and Growth under Iron-Limiting Conditions

    PubMed Central

    Zheng, Huaixin; Chatfield, Christa H.; Liles, Mark R.

    2013-01-01

    Iron acquisition is critical to the growth and virulence of Legionella pneumophila. Previously, we found that L. pneumophila uses both a ferrisiderophore pathway and ferrous iron transport to obtain iron. We now report that two molecules secreted by L. pneumophila, homogentisic acid (HGA) and its polymerized variant (HGA-melanin, a pyomelanin), are able to directly mediate the reduction of various ferric iron salts. Furthermore, HGA, synthetic HGA-melanin, and HGA-melanin derived from bacterial supernatants enhanced the ability of L. pneumophila and other species of Legionella to take up radiolabeled iron. Enhanced iron uptake was not observed with a ferrous iron transport mutant. Thus, HGA and HGA-melanin mediate ferric iron reduction, with the resulting ferrous iron being available to the bacterium for uptake. Upon further testing of L. pneumophila culture supernatants, we found that significant amounts of ferric and ferrous iron were associated with secreted HGA-melanin. Importantly, a pyomelanin-containing fraction obtained from a wild-type culture supernatant was able to stimulate the growth of iron-starved legionellae. That the corresponding supernatant fraction obtained from a nonpigmented mutant culture did not stimulate growth demonstrated that HGA-melanin is able to both promote iron uptake and enhance growth under iron-limiting conditions. Indicative of a complementary role in iron acquisition, HGA-melanin levels were inversely related to the levels of siderophore activity. Compatible with a role in the ecology and pathogenesis of L. pneumophila, HGA and HGA-melanin were effective at reducing and releasing iron from both insoluble ferric hydroxide and the mammalian iron chelates ferritin and transferrin. PMID:23980114

  13. Metabolomic Profiling of 13 Diatom Cultures and Their Adaptation to Nitrate-Limited Growth Conditions.

    PubMed

    Bromke, Mariusz A; Sabir, Jamal S; Alfassi, Fahad A; Hajarah, Nahid H; Kabli, Saleh A; Al-Malki, Abdulrahman L; Ashworth, Matt P; Méret, Michaël; Jansen, Robert K; Willmitzer, Lothar

    2015-01-01

    Diatoms are very efficient in their use of available nutrients. Changes in nutrient availability influence the metabolism and the composition of the cell constituents. Since diatoms are valuable candidates to search for oil producing algae, measurements of diatom-produced compounds can be very useful for biotechnology. In order to explore the diversity of lipophilic compounds produced by diatoms, we describe the results from an analysis of 13 diatom strains. With the help of a lipidomics platform, which combines an UPLC separation with a high resolution/high mass accuracy mass spectrometer, we were able to measure and annotate 142 lipid species. Out of these, 32 were present in all 13 cultures. The annotated lipid features belong to six classes of glycerolipids. The data obtained from the measurements were used to create lipidomic profiles. The metabolomic overview of analysed cultures is amended by the measurement of 96 polar compounds. To further increase the lipid diversity and gain insight into metabolomic adaptation to nitrogen limitation, diatoms were cultured in media with high and low concentrations of nitrate. The growth in nitrogen-deplete or nitrogen-replete conditions affects metabolite accumulation but has no major influence on the species-specific metabolomic profile. Thus, the genetic component is stronger in determining metabolic patterns than nitrogen levels. Therefore, lipid profiling is powerful enough to be used as a molecular fingerprint for diatom cultures. Furthermore, an increase of triacylglycerol (TAG) accumulation was observed in low nitrogen samples, although this trend was not consistent across all 13 diatom strains. Overall, our results expand the current understanding of metabolomics diversity in diatoms and confirm their potential value for producing lipids for either bioenergy or as feed stock. PMID:26440112

  14. Rethinking mutualism stability: cheaters and the evolution of sanctions.

    PubMed

    Frederickson, Megan E

    2013-12-01

    How cooperation originates and persists in diverse species, from bacteria to multicellular organisms to human societies, is a major question in evolutionary biology. A large literature asks: what prevents selection for cheating within cooperative lineages? In mutualisms, or cooperative interactions between species, feedback between partners often aligns their fitness interests, such that cooperative symbionts receive more benefits from their hosts than uncooperative symbionts. But how do these feedbacks evolve? Cheaters might invade symbiont populations and select for hosts that preferentially reward or associate with cooperators (often termed sanctions or partner choice); hosts might adapt to variation in symbiont quality that does not amount to cheating (e.g., environmental variation); or conditional host responses might exist before cheaters do, making mutualisms stable from the outset. I review evidence from yucca-yucca moth, fig-fig wasp, and legume-rhizobium mutualisms, which are commonly cited as mutualisms stabilized by sanctions. Based on the empirical evidence, it is doubtful that cheaters select for host sanctions in these systems; cheaters are too uncommon. Recognizing that sanctions likely evolved for functions other than retaliation against cheaters offers many insights about mutualism coevolution, and about why mutualism evolves in only some lineages of potential hosts. PMID:24552098

  15. Nematode-bacteria mutualism: Selection within the mutualism supersedes selection outside of the mutualism.

    PubMed

    Morran, Levi T; Penley, McKenna J; Byrd, Victoria S; Meyer, Andrew J; O'Sullivan, Timothy S; Bashey, Farrah; Goodrich-Blair, Heidi; Lively, Curtis M

    2016-03-01

    The coevolution of interacting species can lead to codependent mutualists. Little is known about the effect of selection on partners within verses apart from the association. Here, we determined the effect of selection on bacteria (Xenorhabdus nematophila) both within and apart from its mutualistic partner (a nematode, Steinernema carpocapsae). In nature, the two species cooperatively infect and kill arthropods. We passaged the bacteria either together with (M+), or isolated from (M-), nematodes under two different selection regimes: random selection (S-) and selection for increased virulence against arthropod hosts (S+). We found that the isolated bacteria evolved greater virulence under selection for greater virulence (M-S+) than under random selection (M-S-). In addition, the response to selection in the isolated bacteria (M-S+) caused a breakdown of the mutualism following reintroduction to the nematode. Finally, selection for greater virulence did not alter the evolutionary trajectories of bacteria passaged within the mutualism (M+S+ = M+S-), indicating that selection for the maintenance of the mutualism was stronger than selection for increased virulence. The results show that selection on isolated mutualists can rapidly breakdown beneficial interactions between species, but that selection within a mutualism can supersede external selection, potentially generating codependence over time. PMID:26867502

  16. 45 CFR 146.111 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... plan, has diabetes, as well as retinal degeneration, a foot condition, and poor circulation (all of... condition related to D's diabetes, retinal degeneration, foot condition, or poor circulation, even though... health plan provides coverage for the treatment of diabetes, generally not subject to any lifetime...

  17. 29 CFR 2590.701-3 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... provides coverage for the treatment of diabetes, generally not subject to any lifetime dollar limit. However, if an individual was diagnosed with diabetes before the effective date of coverage under the plan, diabetes coverage is subject to a lifetime limit of $10,000. (ii) Conclusion. In this Example 3, the...

  18. 45 CFR 146.111 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... health plan provides coverage for the treatment of diabetes, generally not subject to any lifetime dollar limit. However, if an individual was diagnosed with diabetes before the effective date of coverage under the plan, diabetes coverage is subject to a lifetime limit of $10,000. (ii) Conclusion. In...

  19. 29 CFR 2590.701-3 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... provides coverage for the treatment of diabetes, generally not subject to any lifetime dollar limit. However, if an individual was diagnosed with diabetes before the effective date of coverage under the plan, diabetes coverage is subject to a lifetime limit of $10,000. (ii) Conclusion. In this Example 3, the...

  20. 45 CFR 146.111 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... health plan provides coverage for the treatment of diabetes, generally not subject to any lifetime dollar limit. However, if an individual was diagnosed with diabetes before the effective date of coverage under the plan, diabetes coverage is subject to a lifetime limit of $10,000. (ii) Conclusion. In...

  1. Pluto-charon mutual events

    SciTech Connect

    Binzel, R.P. )

    1989-11-01

    Since 1985, planetary astronomers have been working to take advantage of a once-per-century apparent alignment between Pluto and its satellite, Charon, which has allowed mutual occultation and transit events to be observed. There events, which will cease in 1990, have permitted the first precise determinations of their individual radii, densities, and surface compositions. In addition, information on their surface albedo distributions can be obtained.

  2. Moisture rivals temperature in limiting photosynthesis by trees establishing beyond their cold-edge range limit under ambient and warmed conditions.

    PubMed

    Moyes, Andrew B; Germino, Matthew J; Kueppers, Lara M

    2015-09-01

    Climate change is altering plant species distributions globally, and warming is expected to promote uphill shifts in mountain trees. However, at many cold-edge range limits, such as alpine treelines in the western United States, tree establishment may be colimited by low temperature and low moisture, making recruitment patterns with warming difficult to predict. We measured response functions linking carbon (C) assimilation and temperature- and moisture-related microclimatic factors for limber pine (Pinus flexilis) seedlings growing in a heating × watering experiment within and above the alpine treeline. We then extrapolated these response functions using observed microclimate conditions to estimate the net effects of warming and associated soil drying on C assimilation across an entire growing season. Moisture and temperature limitations were each estimated to reduce potential growing season C gain from a theoretical upper limit by 15-30% (c. 50% combined). Warming above current treeline conditions provided relatively little benefit to modeled net assimilation, whereas assimilation was sensitive to either wetter or drier conditions. Summer precipitation may be at least as important as temperature in constraining C gain by establishing subalpine trees at and above current alpine treelines as seasonally dry subalpine and alpine ecosystems continue to warm. PMID:25902893

  3. 42 CFR 410.37 - Colorectal cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Colorectal cancer screening tests: Conditions for...) BENEFITS Medical and Other Health Services § 410.37 Colorectal cancer screening tests: Conditions for and...) Colorectal cancer screening tests means any of the following procedures furnished to an individual for...

  4. An Analysis of Sequential Variables in Pavlovian Conditioning Employing Extended and Limited Acquisition Training

    ERIC Educational Resources Information Center

    Miller, Ronald Mellado; Capaldi, E. John

    2006-01-01

    Sequential theory's memory model of learning has been successfully applied in response contingent instrumental conditioning experiments (Capaldi, 1966, 1967, 1994; Capaldi & Miller, 2003). However, it has not been systematically tested in nonresponse contingent Pavlovian conditioning experiments. The present experiments attempted to determine if…

  5. An Analysis of Sequential Variables in Pavlovian Conditioning Employing Extended and Limited Acquisition Training

    ERIC Educational Resources Information Center

    Miller, Ronald Mellado; Capaldi, E. John

    2006-01-01

    Sequential theory's memory model of learning has been successfully applied in response contingent instrumental conditioning experiments (Capaldi, 1966, 1967, 1994; Capaldi & Miller, 2003). However, it has not been systematically tested in nonresponse contingent Pavlovian conditioning experiments. The present experiments attempted to determine if…

  6. 42 CFR 410.37 - Colorectal cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Colorectal cancer screening tests: Conditions for...) BENEFITS Medical and Other Health Services § 410.37 Colorectal cancer screening tests: Conditions for and...) Colorectal cancer screening tests means any of the following procedures furnished to an individual for...

  7. 42 CFR 410.37 - Colorectal cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Colorectal cancer screening tests: Conditions for...) BENEFITS Medical and Other Health Services § 410.37 Colorectal cancer screening tests: Conditions for and...) Colorectal cancer screening tests means any of the following procedures furnished to an individual for...

  8. 42 CFR 410.37 - Colorectal cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Colorectal cancer screening tests: Conditions for...) BENEFITS Medical and Other Health Services § 410.37 Colorectal cancer screening tests: Conditions for and...) Colorectal cancer screening tests means any of the following procedures furnished to an individual for...

  9. 42 CFR 410.37 - Colorectal cancer screening tests: Conditions for and limitations on coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Colorectal cancer screening tests: Conditions for...) BENEFITS Medical and Other Health Services § 410.37 Colorectal cancer screening tests: Conditions for and...) Colorectal cancer screening tests means any of the following procedures furnished to an individual for...

  10. Limited condition dependence of male acoustic signals in the grasshopper Chorthippus biguttulus

    PubMed Central

    Franzke, Alexandra; Reinhold, Klaus

    2012-01-01

    In many animal species, male acoustic signals serve to attract a mate and therefore often play a major role for male mating success. Male body condition is likely to be correlated with male acoustic signal traits, which signal male quality and provide choosy females indirect benefits. Environmental factors such as food quantity or quality can influence male body condition and therefore possibly lead to condition-dependent changes in the attractiveness of acoustic signals. Here, we test whether stressing food plants influences acoustic signal traits of males via condition-dependent expression of these traits. We examined four male song characteristics, which are vital for mate choice in females of the grasshopper Chorthippus biguttulus. Only one of the examined acoustic traits, loudness, was significantly altered by changing body condition because of drought- and moisture-related stress of food plants. No condition dependence could be observed for syllable to pause ratio, gap duration within syllables, and onset accentuation. We suggest that food plant stress and therefore food plant quality led to shifts in loudness of male grasshopper songs via body condition changes. The other three examined acoustic traits of males do not reflect male body condition induced by food plant quality. PMID:22957192

  11. Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

    PubMed Central

    2011-01-01

    Background The oxygen transfer rate (OTR) and dissolved oxygen tension (DOT) play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type A. vinelandii strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTRmax) in cultures where the dissolved oxygen tension (DOT) was kept constant. Results The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm) caused a significant increase in the OTRmax (from 17 to 100 mmol L-1 h-1 for DOT of 5% and from 6 to 70 mmol L-1 h-1 for DOT of 0.5%). This increase in the OTRmax improved alginate production, as well as the specific alginate production rate (SAPR), reaching a maximal alginate concentration of 3.1 g L-1 and a SAPR of 0.031 g alg g biom-1 h-1 in the cultures at OTRmax of 100 mmol L-1 h-1. In contrast, the mean molecular mass (MMM) of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTRmax, reaching a maximal of 550 kDa at an OTRmax of 17 mmol L-1 h-1 . However, in the cultures developed under oxygen limitation (0.5% DOT), the MMM of the polymer was practically the same (around 200 kDa) at 300 and 700 rpm, and this remained constant throughout the cultivation. Conclusions Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTRmax, independently of the DOT of the culture. PMID:21352581

  12. Holographic mutual information in global Vaidya-BTZ spacetime

    NASA Astrophysics Data System (ADS)

    Ziogas, Vaios

    2015-09-01

    We investigate the evolution of the mutual information between two spatial subsystems in a compact 1+1 dimensional CFT after a quantum quench. To this end, we use the dual holographic process, given by the 2+1 dimensional Vaidya-BTZ spacetime in global coordinates, which describes the collapse of a spherically symmetric null shell. So, we first discuss the spacelike geodesic structure of this geometry and then we present the various behaviors of the holographic mutual information observed in this case. We also consider the analogous process in the adiabatic limit and compare these two cases from a geometrical point of view.

  13. Using Multiple Approaches, including ?18O Signatures of Phosphate to Investigate Potential Phosphorus Limitation and Cycling under Changing Climate Conditions

    NASA Astrophysics Data System (ADS)

    Roberts, K.; Paytan, A.; Field, C. B.; Honn, E.; Edwards, E.; Gottlieb, R.

    2012-12-01

    Phosphorus (P) is often a limiting or co-limiting nutrient in terrestrial systems. It has been proposed that it will play an even greater role in ecosystems experiencing some of the many predicted effects of climate change, in particular release from nitrogen limitation. Recent work in 2007 by Menge et al. suggests that this is indeed a possibility. To investigate the potential for P limitation, and P cycling under multiple controlled conditions we collected samples from the Jasper Ridge Global Change Experiment (JRGCE) in May 2011. For over a decade the JRGCE has been manipulating four key parameters predicted to change in the future in a native Californian grassland system. Elevated Nitrogen deposition, increased precipitation, increased pCO2, and increased temperature are applied and monitored in a split plot design at the Jasper Ridge Biological Preserve in the eastern foothills of the Santa Cruz Mountains, California. Work done previously at the site using a suite of indicators of the potential P limitation suggest P limitation in some of the manipulated plots in the JRGCE. In this study we replicate a subset of the prior analyses to compare inter-annual signals of P limitation, and further attempt to utilize the oxygen isotopes of phosphate to investigate P cycling in soils at JRGCE. A fractional soil extraction process for phosphate enables separation of several operationally defined P pools, and provides auxiliary information regarding the relative concentrations of bio-available P, and relevant minerals in this grassland system under the varied conditions.

  14. Assessment and treatment of nonpain conditions in life-limiting disease.

    PubMed

    Villalobos, Alice E

    2011-05-01

    The "Pawspice" philosophy, which the author introduced at the 2000 American Veterinary Medical Association meeting, focuses on symptom management along with a kinder, gentler, or modified approach to standard therapy. Many veterinarians have preconceived bias or ingrained beliefs about aging, serious illness, multiple comorbidities, and cancer, which may cause a negative or dismissive approach toward palliative treatment, especially in geriatric pets. Veterinarians and their v-teams must overcome this insensitive attitude about life-limiting disease. This article describes assessment, treatment, and home management of some nonpainful life-limiting diseases, including cancer and age-related decline of vital functions in the Pawspice setting. PMID:21601746

  15. Population dynamics and mutualism: Functional responses of benefits and costs

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.; Bronstein, Judith L.

    2002-01-01

    We develop an approach for studying population dynamics resulting from mutualism by employing functional responses based on density‐dependent benefits and costs. These functional responses express how the population growth rate of a mutualist is modified by the density of its partner. We present several possible dependencies of gross benefits and costs, and hence net effects, to a mutualist as functions of the density of its partner. Net effects to mutualists are likely a monotonically saturating or unimodal function of the density of their partner. We show that fundamental differences in the growth, limitation, and dynamics of a population can occur when net effects to that population change linearly, unimodally, or in a saturating fashion. We use the mutualism between senita cactus and its pollinating seed‐eating moth as an example to show the influence of different benefit and cost functional responses on population dynamics and stability of mutualisms. We investigated two mechanisms that may alter this mutualism's functional responses: distribution of eggs among flowers and fruit abortion. Differences in how benefits and costs vary with density can alter the stability of this mutualism. In particular, fruit abortion may allow for a stable equilibrium where none could otherwise exist.

  16. Mutuality: clinical and metapsychological potentials of a failed experiment.

    PubMed

    Castillo Mendoza, Carlos Alberto

    2012-03-01

    Ferenczi's experiments with mutual analysis are often dismissed, without acknowledging the results obtained from them and his own cautionary remarks about their limits. Though ultimately failed, Ferenczi's experiments with mutual analysis were a source of clinical and metapsychological knowledge, despite the fact that he was unable to elaborate them in his lifetime. In this paper I connect mutuality to the development of the psyche, especially to the constitutive core of the intrapsychic. To understand the latter, it is necessary to take into account, among others, issues such as the common attribute, the mutual flux between the unconsciouses, the dialogue of unconsciouses, the maternal profundity, the primal relationship with the mother, and, above all, the primal unity between mother and child, which are fundamental for the emergence and development of the primary psychic forces. Incidences of rupture, distortion of the core of mutuality in the psychic life, its loss and disadjustment, by means of external traumatizing forces, and some clinical implications are described. PMID:22398886

  17. 7 CFR 301.76-5 - General conditions governing the issuance of any certificate or limited permit; provisions for...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Greening and Asian Citrus Psyllid § 301.76-5 General conditions governing the issuance of any certificate or limited... Act (7 U.S.C. 7714) 2 /> to prevent the spread of Asian citrus psyllid; and 2 An inspector may...

  18. 7 CFR 301.76-5 - General conditions governing the issuance of any certificate or limited permit; provisions for...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Greening and Asian Citrus Psyllid § 301.76-5 General conditions governing the issuance of any certificate or limited... Act (7 U.S.C. 7714) 2 /> to prevent the spread of Asian citrus psyllid; and 2 An inspector may...

  19. 7 CFR 301.76-5 - General conditions governing the issuance of any certificate or limited permit; provisions for...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Greening and Asian Citrus Psyllid § 301.76-5 General conditions governing the issuance of any certificate or limited... Act (7 U.S.C. 7714) 2 /> to prevent the spread of Asian citrus psyllid; and 2 An inspector may...

  20. 7 CFR 301.76-5 - General conditions governing the issuance of any certificate or limited permit; provisions for...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Greening and Asian Citrus Psyllid § 301.76-5 General conditions governing the issuance of any certificate or limited... Act (7 U.S.C. 7714) 2 to prevent the spread of Asian citrus psyllid; and 2 An inspector may hold...

  1. 47 CFR 90.1432 - Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public safety spectrum. 90.1432 Section 90.1432 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES 700 MHz...

  2. GCM Simulations of Neoproterozoic "Snowball Earth" Conditions: Implications for the Environmental Limits on Terrestrial Metazoans and Their Extraterrestrial Analogues

    NASA Technical Reports Server (NTRS)

    Sohl, L. E.; Chandler, M. A.

    2001-01-01

    The Neoproterozoic Snowball Earth intervals provide excellent opportunities to examine the environmental limits on terrestrial metazoans. A series of GCM simulations was run in order to quantify climatic conditions during these intervals. Additional information is contained in the original extended abstract.

  3. 10 CFR Appendix I to Part 50 - Numerical Guides for Design Objectives and Limiting Conditions for Operation To Meet the...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... light-water-cooled nuclear power reactors licensed under 10 CFR part 50 or part 52 of this chapter. The... 10 CFR part 50 or part 52 of this chapter. The guides on limiting conditions for operation for light... annual total quantity of all radioactive iodine and radioactive material in particulate form...

  4. 10 CFR Appendix I to Part 50 - Numerical Guides for Design Objectives and Limiting Conditions for Operation To Meet the...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... light-water-cooled nuclear power reactors licensed under 10 CFR part 50 or part 52 of this chapter. The... 10 CFR part 50 or part 52 of this chapter. The guides on limiting conditions for operation for light... annual total quantity of all radioactive iodine and radioactive material in particulate form...

  5. 10 CFR Appendix I to Part 50 - Numerical Guides for Design Objectives and Limiting Conditions for Operation To Meet the...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... light-water-cooled nuclear power reactors licensed under 10 CFR part 50 or part 52 of this chapter. The... 10 CFR part 50 or part 52 of this chapter. The guides on limiting conditions for operation for light... annual total quantity of all radioactive iodine and radioactive material in particulate form...

  6. 10 CFR Appendix I to Part 50 - Numerical Guides for Design Objectives and Limiting Conditions for Operation To Meet the...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... light-water-cooled nuclear power reactors licensed under 10 CFR part 50 or part 52 of this chapter. The... 10 CFR part 50 or part 52 of this chapter. The guides on limiting conditions for operation for light... annual total quantity of all radioactive iodine and radioactive material in particulate form...

  7. 76 FR 10213 - Special Conditions: Embraer Model EMB-135BJ (Legacy 650) Airplanes, Limit Engine Torque Loads for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... 650) Airplanes, Limit Engine Torque Loads for Sudden Engine Stoppage AGENCY: Federal Aviation... engine size and the potential torque load imposed by sudden engine-stoppage conditions. The applicable... incorporate novel or unusual design features involving engine size and the potential torque load imposed...

  8. Binary phase oscillation of two mutually coupled semiconductor lasers.

    PubMed

    Utsunomiya, Shoko; Namekata, Naoto; Takata, Kenta; Akamatsu, Daisuke; Inoue, Shuichiro; Yamamoto, Yoshihisa

    2015-03-01

    A two-site Ising model is implemented as an injection-locked laser network consisting of a single master laser and two mutually coupled slave lasers. We observed ferromagnetic and antiferromagnetic orders in the in-phase and out-of-phase couplings between the two slave lasers. Their phase difference is locked to either 0 or ? even if the coupling path is continuously modulated. The system automatically selects the oscillation frequency to satisfy the in-phase or out-of-phase coupling condition, when the mutual coupling dominates over the injection-locking by the master laser. PMID:25836827

  9. Hydrogen isotope exchange and conditioning in graphite limiters used in TFTR

    SciTech Connect

    LaMarche, P.H.; Dylla, H.F.; McCarthy, P.J.; Ulrickson, M.

    1986-02-01

    Isotopic exchange experiments performed in TFTR are used to examine the outgassing and diffusive properties of graphite used as the plasma limiter. Changeover from hydrogen to deuterium for different periods ranges from approx.600 to 60 plasma discharges, which appears to be correlated to the limiter temperature. We present a simple analytical model that predicts a fast transient (approx.10 plasma discharges) changeover where the deuterium fueling dilutes the adsorbed and near-surface hydrogen, and a slowly changing term where bulk hydrogen diffuses to the surface. Using this model we can extract an activation energy for diffusion of 0.15 +- 0.02 eV. We hypothesize that interpore diffusion for this porous (approx.15%) material is consistent with our observations. 19 refs.

  10. Polyhydroxyalkanoates from Pseudomonas sp. using synthetic and olive mill wastewater under limiting conditions.

    PubMed

    Kourmentza, C; Ntaikou, I; Lyberatos, G; Kornaros, M

    2015-03-01

    The present study aimed at investigating the ability of bacteria isolated from an enriched mixed culture to produce polyhydroxyalkanoates (PHAs) and examining the effect of nitrogen and dual nitrogen-oxygen limitation on PHAs production, by using both synthetic and olive mill wastewater (OMW). PHAs production was performed through batch experiments using both the enriched culture and the isolated strains (belonging to the genus of Pseudomonas) aiming to compare PHAs accumulation capacity, yields and rates. The use of enriched culture and synthetic wastewater under nitrogen limitation resulted in the highest PHA accumulation, i.e. 64.4%gPHAs/g of cell dry mass (CDM). However, when OMW was used, PHAs accumulation significantly decreased, i.e. 8.8%gPHAs/g CDM. The same trend was followed by the isolated strains, nevertheless, their ability to synthesize PHAs was lower. Although, dual nitrogen-oxygen limitation generally slowed down PHAs biosynthesis, in certain strains PHAs production was positively affected. PMID:25542172

  11. Finding Mutual Exclusion Invariants in Temporal Planning Domains

    NASA Technical Reports Server (NTRS)

    Bernardini, Sara; Smith, David E.

    2011-01-01

    We present a technique for automatically extracting temporal mutual exclusion invariants from PDDL2.2 planning instances. We first identify a set of invariant candidates by inspecting the domain and then check these candidates against properties that assure invariance. If these properties are violated, we show that it is sometimes possible to refine a candidate by adding additional propositions and turn it into a real invariant. Our technique builds on other approaches to invariant synthesis presented in the literature, but departs from their limited focus on instantaneous discrete actions by addressing temporal and numeric domains. To deal with time, we formulate invariance conditions that account for both the entire structure of the operators (including the conditions, rather than just the effects) and the possible interactions between operators. As a result, we construct a technique that is not only capable of identifying invariants for temporal domains, but is also able to find a broader set of invariants for non-temporal domains than the previous techniques.

  12. Exercise restrictions for patients with inherited cardiac conditions: Current guidelines, challenges and limitations.

    PubMed

    Hammond-Haley, Matthew; Patel, Riyaz S; Providência, Rui; Lambiase, Pier D

    2016-04-15

    Inherited primary arrhythmia syndromes are a clinically heterogeneous group of relatively uncommon but important inherited cardiac conditions that are associated with an increased risk of sudden cardiac death (SCD) in the setting of a structurally normal heart. These include long-QT syndrome (LQTS), Short-QT syndrome (SQTS), Brugada syndrome (BrS) and Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). The cardiomyopathies represent the other major group of inherited cardiac conditions associated with SCD, of which hypertrophic cardiomyopathy (HCM) is the most common. Exercise is a known trigger of ventricular arrhythmias in many of these conditions, however marked genetic and clinical heterogeneity within individual diseases means that certain patients are at a much greater risk of lethal ventricular arrhythmias during exercise than others. For instance, LQTS type 1 (LQT1) and CPVT patients are at particular risk during exertion, whilst in patients with other genetic variants of LQTS, BrS and SQTS, alternative triggers are more significant precipitants. Many channelopathy (principally Brugada, CPVT) & cardiomyopathy (mainly HCM) patients receive primary or secondary prevention therapy with an implantable cardiac defibrillator (ICD). Exercising with an ICD in situ carries a range of additional risks including inappropriate shocks and lead complications. This review will focus on the risk of exercise-induced SCD in patients with inherited cardiac conditions, the current clinical guidelines in this area and the special consideration of patients with an ICD. PMID:26897076

  13. The effect of limiter conditioning on the Tokamak Fusion Test Reactor edge plasma

    SciTech Connect

    Kilpatrick, S.J.; Manos, D.M.; Nyberg, I.; Ramsey, A.T.; Stratton, B.C.; Timberlake, J.; Ulrickson, M.J.; Pitcher, C.S.; Dylla, H.F.

    1991-07-01

    Measurements by moveable Langmuir probes and edge spectroscopy diagnostics have documented the conditioning effect of low density helium-initiated discharge sequences on the Tokamak Fusion Test Reactor (TFTR) edge plasma. Langmuir probe measurements show in general that the edge electron density n{sub e} decreases by less than a factor of 2 while the edge electron temperature T{sub e} doubles. Radial profiles to the plasma boundary show that the density scrape-off length increases somewhat while the temperature scrape-off length decreases substantially. The particle flux density is unaffected. The spectral emission of C 2 decreases by a factor of 2, a much smaller change than that exhibited by the D{sub {alpha}} signal. These results complement previous accounts of the conditioning technique. Comparisons of these He conditioning measurements are made to edge measurements during a deuterium density scan experiment, showing many similarities, and to an existing edge model of the conditioning process, showing qualitative agreement. 20 refs., 5 figs.

  14. The effect of limiter conditioning on the Tokamak Fusion Test Reactor edge plasma

    SciTech Connect

    Kilpatrick, S.J.; Pitcher, C.S.; Dylla, H.F.; Manos, D.M.; Nyberg, I.; Ramsey, A.T.; Stratton, B.C.; Timberlake, J.; Ulrickson, M.J. )

    1991-05-01

    Measurements by moveable Langmuir probes and edge spectroscopy diagnostics have documented the conditioning effect of low-density helium-initiated discharge sequences on the Tokamak Fusion Test Reactor edge plasma. Langmuir probe measurements shown in general that the edge electron density {ital n}{sub {ital e}} decreases by less than a factor of 2 while the edge electron temperature {ital T}{sub {ital e}} doubles. Radial profiles to the plasma boundary show that the density scrape-off length increases somewhat while the temperature scrape-off length decreases substantially. The particle flux density is unaffected. The spectral emission of C II decreases by a factor of 2, a much smaller change than that exhibited by the {ital D}{sub {alpha}} signal. These results complement previous accounts of the conditioning technique. Comparisons of these He conditioning measurements are made to edge measurements during a deuterium density scan experiment, showing many similarities, and to an existing edge model of the conditioning process, showing qualitative agreement.

  15. Biomass and cellulosic ethanol production of forage sorghum under limited water conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two year field study was conducted to evaluate biofuel production potential of two forage sorghum cultivars differing in brown midrib trait under non-irrigated and deficit irrigation conditions in the semiarid Southern High Plains of the U.S. Cultivar SP1990 (non-bmr = conventional cell wall comp...

  16. 76 FR 44245 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... FR 25648). One supportive comment was received and the special conditions are adopted as proposed..., modern high bypass engines are subject to certain rare-but-severe engine seizure events. Service history... the airplane to be able to support such rare loads safely without failure, it is unrealistic to...

  17. 45 CFR 146.111 - Limitations on preexisting condition exclusion period.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... on genetic information, A has a predisposition towards breast cancer. A was not diagnosed with breast... plan, A is diagnosed with breast cancer. (ii) Conclusion. In this Example, the plan may not impose a preexisting condition exclusion with respect to A's breast cancer because, prior to A's enrollment date, A...

  18. Validity conditions for stochastic chemical kinetics in diffusion-limited systems

    PubMed Central

    Gillespie, Daniel T.; Petzold, Linda R.; Seitaridou, Effrosyni

    2014-01-01

    The chemical master equation (CME) and the mathematically equivalent stochastic simulation algorithm (SSA) assume that the reactant molecules in a chemically reacting system are “dilute” and “well-mixed” throughout the containing volume. Here we clarify what those two conditions mean, and we show why their satisfaction is necessary in order for bimolecular reactions to physically occur in the manner assumed by the CME and the SSA. We prove that these conditions are closely connected, in that a system will stay well-mixed if and only if it is dilute. We explore the implications of these validity conditions for the reaction-diffusion (or spatially inhomogeneous) extensions of the CME and the SSA to systems whose containing volumes are not necessarily well-mixed, but can be partitioned into cubical subvolumes (voxels) that are. We show that the validity conditions, together with an additional condition that is needed to ensure the physical validity of the diffusion-induced jump probability rates of molecules between voxels, require the voxel edge length to have a strictly positive lower bound. We prove that if the voxel edge length is steadily decreased in a way that respects that lower bound, the average rate at which bimolecular reactions occur in the reaction-diffusion CME and SSA will remain constant, while the average rate of diffusive transfer reactions will increase as the inverse square of the voxel edge length. We conclude that even though the reaction-diffusion CME and SSA are inherently approximate, and cannot be made exact by shrinking the voxel size to zero, they should nevertheless be useful in many practical situations. PMID:24511926

  19. Defense mutualisms enhance plant diversification

    PubMed Central

    Weber, Marjorie G.; Agrawal, Anurag A.

    2014-01-01

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  20. The limits of the adaptation of life to extreme conditions (in connection with problems of exobiology)

    NASA Technical Reports Server (NTRS)

    Aksenov, S. I.

    1973-01-01

    Accommodation is discussed as a universal evolutionary principle which essentially will apply to all life forms, regardless of chemical base (carbon, silicon, etc.). Life forms must either adapt to extreme conditions or perish, and for any life form an extremum factor is any significant deviation in environmental parameters. The possibility of life forms existing in specific extraterrestrial environments is discussed, and a conclusion is drawn which unequivocally states that through many forms of accommodation life is possible in many different environments.

  1. An Individual-Based Diploid Model Predicts Limited Conditions Under Which Stochastic Gene Expression Becomes Advantageous

    PubMed Central

    Matsumoto, Tomotaka; Mineta, Katsuhiko; Osada, Naoki; Araki, Hitoshi

    2015-01-01

    Recent studies suggest the existence of a stochasticity in gene expression (SGE) in many organisms, and its non-negligible effect on their phenotype and fitness. To date, however, how SGE affects the key parameters of population genetics are not well understood. SGE can increase the phenotypic variation and act as a load for individuals, if they are at the adaptive optimum in a stable environment. On the other hand, part of the phenotypic variation caused by SGE might become advantageous if individuals at the adaptive optimum become genetically less-adaptive, for example due to an environmental change. Furthermore, SGE of unimportant genes might have little or no fitness consequences. Thus, SGE can be advantageous, disadvantageous, or selectively neutral depending on its context. In addition, there might be a genetic basis that regulates magnitude of SGE, which is often referred to as “modifier genes,” but little is known about the conditions under which such an SGE-modifier gene evolves. In the present study, we conducted individual-based computer simulations to examine these conditions in a diploid model. In the simulations, we considered a single locus that determines organismal fitness for simplicity, and that SGE on the locus creates fitness variation in a stochastic manner. We also considered another locus that modifies the magnitude of SGE. Our results suggested that SGE was always deleterious in stable environments and increased the fixation probability of deleterious mutations in this model. Even under frequently changing environmental conditions, only very strong natural selection made SGE adaptive. These results suggest that the evolution of SGE-modifier genes requires strict balance among the strength of natural selection, magnitude of SGE, and frequency of environmental changes. However, the degree of dominance affected the condition under which SGE becomes advantageous, indicating a better opportunity for the evolution of SGE in different genetic models. PMID:26635872

  2. Utilizing Mutual Aid in Reducing Adolescent Substance Use and Developing Group Engagement

    ERIC Educational Resources Information Center

    Mogro-Wilson, Cristina; Letendre, Joan; Toi, Hiroki; Bryan, Janelle

    2015-01-01

    Objective: This study assessed the effectiveness of mutual aid groups for high school students. Methods: A quasi-experimental design was applied to 242 adolescents, where every other adolescent was assigned to the intervention or the control condition. The study evaluated the influence of implementing mutual aid groups in decreasing perceived risk…

  3. Utilizing Mutual Aid in Reducing Adolescent Substance Use and Developing Group Engagement

    ERIC Educational Resources Information Center

    Mogro-Wilson, Cristina; Letendre, Joan; Toi, Hiroki; Bryan, Janelle

    2015-01-01

    Objective: This study assessed the effectiveness of mutual aid groups for high school students. Methods: A quasi-experimental design was applied to 242 adolescents, where every other adolescent was assigned to the intervention or the control condition. The study evaluated the influence of implementing mutual aid groups in decreasing perceived risk…

  4. Scaling Hydrodynamic Boundary Conditions of Microstructured Surfaces in the Thin Channel Limit.

    PubMed

    Pilkington, Georgia A; Gupta, Rohini; Fréchette, Joëlle

    2016-03-15

    Despite its importance in many applications and processes, a complete and unified view on how nano- and microscale asperities influence hydrodynamic interactions has yet to be reached. In particular, the effects of surface structure can be expected to become more dominant when the length scale of the asperities or textures becomes comparable to that of the fluid flow. Here we analyze the hydrodynamic drainage of a viscous silicone oil squeezed between a smooth plane and a surface decorated with hexagonal arrays of lyophilic microsized cylindrical posts. For all micropost arrays studied, the periodicity of the structures was much larger than the separation range of our measurements. In this thin channel geometry, we find the hydrodynamic drainage and separation forces for the micropost arrays cannot be fully described by existing boundary condition models for interfacial slip or a no-slip shifted plane. Instead, our results show that the influence of the microposts on the hydrodynamic drag exhibits three distinct regimes as a function of separation. For large separations, a no slip boundary condition (Reynolds theory) is observed for all surfaces until a critical (intermediate) separation, below which the position of the no-slip plane scales with surface separation until reaching a maximum, just before contact. Below this separation, a sharp decrease in the no-slip plane position then suggests that a boundary condition of a smooth surface is recovered at contact. PMID:26901492

  5. Factors limiting endurance of armor, artillery, and infantry units under simulated NBC conditions

    SciTech Connect

    Rauch, T.M.; Tharion, W.J.; Banderet, L.E.; Lussier, A.R.

    1986-03-13

    The war of the future will require 72-hour operations in environments contaminated with nuclear/biological/chemical (NBC) agents. The 1985 P2NBC2 (Physiological and Psychological Effects of NBC and Extended Operations on Combined Arms Crews) Program assessed soldier endurance and performance under simulated NBC conditions. A total of 175 soldiers were observed during four tests differing in design, site, climatic conditions, and performance demands. In all but one of the iterations where the full chemical-protective ensemble (MOPP 4) was used without cooling, soldier endurance fell far short of the projected requirement. Psychological data were analyzed to determine which factors were associated with the incidence of casualties. The findings showed that perceived intensity of symptoms resembling the hyperventilation syndrome was significantly greater in soldiers classified as Casualties. Five of these symptoms (painful breathing, difficulty breathing, shortness of breath, headache, and nausea) showed Casualty-Survivor differences in all tests. Symptom intensity was attributed to two factors. (1) External conditions. Thermal stress exacerbated the five basic symptoms, induced others (tetany and paresthesia), and decreased endurance. Periodic relief from respirator use attenuated these symptoms and enhanced endurance. (2) Individual differences. Significant Casualty-Survivor differences in anxiety, depression, and cognitive strategy scores indicated that perception of hyperventilation symptoms and endurance were related to personality variables. Hyperventilation symptoms could incapacitate the soldier or induce removal of the protective mask under actual chemical attack.

  6. Mutually-antagonistic interactions in baseball networks

    NASA Astrophysics Data System (ADS)

    Saavedra, Serguei; Powers, Scott; McCotter, Trent; Porter, Mason A.; Mucha, Peter J.

    2010-03-01

    We formulate the head-to-head matchups between Major League Baseball pitchers and batters from 1954 to 2008 as a bipartite network of mutually-antagonistic interactions. We consider both the full network and single-season networks, which exhibit structural changes over time. We find interesting structure in the networks and examine their sensitivity to baseball’s rule changes. We then study a biased random walk on the matchup networks as a simple and transparent way to (1) compare the performance of players who competed under different conditions and (2) include information about which particular players a given player has faced. We find that a player’s position in the network does not correlate with his placement in the random walker ranking. However, network position does have a substantial effect on the robustness of ranking placement to changes in head-to-head matchups.

  7. Teleportation of qubit states through dissipative channels: Conditions for surpassing the no-cloning limit

    SciTech Connect

    Oezdemir, Sahin Kaya; Bartkiewicz, Karol; Liu, Yu-xi; Miranowicz, Adam

    2007-10-15

    We investigate quantum teleportation through dissipative channels and calculate teleportation fidelity as a function of damping rates. It is found that the average fidelity of teleportation and the range of states to be teleported depend on the type and rate of the damping in the channel. Using the fully entangled fraction, we derive two bounds on the damping rates of the channels: one is to beat the classical limit and the second is to guarantee the nonexistence of any other copy with better fidelity. The effect of the initially distributed maximally entangled state on the process is presented; the concurrence and the fully entangled fraction of the shared states are discussed. We intend to show that prior information on the dissipative channel and the range of qubit states to be teleported is helpful for the evaluation of the success of teleportation, where success is defined as surpassing the fidelity limit imposed by the fidelity of the 1-to-2 optimal cloning machine for the specific range of qubits.

  8. Respite care needs for families of children with life-limiting conditions.

    PubMed

    Bowman, Janet; Butcher, Ruth; Dolby, Sue

    2011-07-01

    The Framework for Respite in Partnership with Parents (FRiPP), developed by the Jessie May Trust is a tool to enable a standardised and equitable allocation of a limited resource. FRiPP reduces the opportunity for subjective allocation of respite-based care stemming from the professional-led model of telling families what they need. The tool is aimed at engaging families in identifying and articulating the support they require. After a successful pilot and evaluation, FRiPP is now used for all families on the Jessie May Trust's caseload. The authors reflect on the tool's development and implementation process in the context of promoting and protecting partnership working. PMID:21834420

  9. Explaining mutualism variation: a new evolutionary paradox?

    PubMed

    Heath, Katy D; Stinchcombe, John R

    2014-02-01

    The paradox of mutualism is typically framed as the persistence of interspecific cooperation, despite the potential advantages of cheating. Thus, mutualism research has tended to focus on stabilizing mechanisms that prevent the invasion of low-quality partners. These mechanisms alone cannot explain the persistence of variation for partner quality observed in nature, leaving a large gap in our understanding of how mutualisms evolve. Studying partner quality variation is necessary for applying genetically explicit models to predict evolution in natural populations, a necessary step for understanding the origins of mutualisms as well as their ongoing dynamics. An evolutionary genetic approach, which is focused on naturally occurring mutualist variation, can potentially synthesize the currently disconnected fields of mutualism evolution and coevolutionary genetics. We outline explanations for the maintenance of genetic variation for mutualism and suggest approaches necessary to address them. PMID:24303853

  10. Unravelling Carbon Fixation under Nutrient limited Conditions - a Water Column Perspective

    NASA Astrophysics Data System (ADS)

    Thomas, Helmuth; Craig, Susanne; Shadwick, Elizabeth H.; Li, William K.; Greenan, Blair J. W.

    2014-05-01

    Phytoplankton plays a critical role in the uptake of atmospheric carbon dioxide (CO2) by the ocean, and is comprised of a spectrum of cell sizes that are strongly regulated by oceanographic conditions. Elevated CO2 fixation relative to nutrient availability, also called carbon overconsumption, has been observed in various mid to high latitude systems, such as the Baltic and North Seas, the North Atlantic Ocean, the Canadian Arctic Archipelago or the Scotian Shelf. We shed light on this phenomenon relying on an extensive data set of water column observations of the CO2 system and phytoplankton cell counts from the Scotian Shelf, a temperate shelf sea. We show that in the summertime, the population of numerically abundant small cells, which favour warmer, nutrient poor conditions, accounts for approximately 20% of annual carbon uptake. At the broader scale, the neglection of this "non-Redfieldian" contribution typically leads to an underestimation of net community production by approximately 20% to 50%. These small cells are not well represented by chlorophyll a - the ubiquitously used proxy of phytoplankton biomass - but rather, are strongly correlated with surface water temperature. Given the persistent near-zero nutrient concentrations during the summer, it appears that small cells drive carbon overconsumption, and suggest that their role in carbon fixation will become increasingly important in a warming, increasingly stratified ocean.

  11. Water-Limiting Conditions Alter the Structure and Biofilm-Forming Ability of Bacterial Multispecies Communities in the Alfalfa Rhizosphere

    PubMed Central

    Bogino, Pablo; Abod, Ayelén; Nievas, Fiorela; Giordano, Walter

    2013-01-01

    Biofilms are microbial communities that adhere to biotic or abiotic surfaces and are enclosed in a protective matrix of extracellular compounds. An important advantage of the biofilm lifestyle for soil bacteria (rhizobacteria) is protection against water deprivation (desiccation or osmotic effect). The rhizosphere is a crucial microhabitat for ecological, interactive, and agricultural production processes. The composition and functions of bacterial biofilms in soil microniches are poorly understood. We studied multibacterial communities established as biofilm-like structures in the rhizosphere of Medicago sativa (alfalfa) exposed to 3 experimental conditions of water limitation. The whole biofilm-forming ability (WBFA) for rhizospheric communities exposed to desiccation was higher than that of communities exposed to saline or nonstressful conditions. A culture-dependent ribotyping analysis indicated that communities exposed to desiccation or saline conditions were more diverse than those under the nonstressful condition. 16S rRNA gene sequencing of selected strains showed that the rhizospheric communities consisted primarily of members of the Actinobacteria and α- and γ-Proteobacteria, regardless of the water-limiting condition. Our findings contribute to improved understanding of the effects of environmental stress factors on plant-bacteria interaction processes and have potential application to agricultural management practices. PMID:24223979

  12. Water-limiting conditions alter the structure and biofilm-forming ability of bacterial multispecies communities in the alfalfa rhizosphere.

    PubMed

    Bogino, Pablo; Abod, Ayelén; Nievas, Fiorela; Giordano, Walter

    2013-01-01

    Biofilms are microbial communities that adhere to biotic or abiotic surfaces and are enclosed in a protective matrix of extracellular compounds. An important advantage of the biofilm lifestyle for soil bacteria (rhizobacteria) is protection against water deprivation (desiccation or osmotic effect). The rhizosphere is a crucial microhabitat for ecological, interactive, and agricultural production processes. The composition and functions of bacterial biofilms in soil microniches are poorly understood. We studied multibacterial communities established as biofilm-like structures in the rhizosphere of Medicago sativa (alfalfa) exposed to 3 experimental conditions of water limitation. The whole biofilm-forming ability (WBFA) for rhizospheric communities exposed to desiccation was higher than that of communities exposed to saline or nonstressful conditions. A culture-dependent ribotyping analysis indicated that communities exposed to desiccation or saline conditions were more diverse than those under the nonstressful condition. 16S rRNA gene sequencing of selected strains showed that the rhizospheric communities consisted primarily of members of the Actinobacteria and ?- and ?-Proteobacteria, regardless of the water-limiting condition. Our findings contribute to improved understanding of the effects of environmental stress factors on plant-bacteria interaction processes and have potential application to agricultural management practices. PMID:24223979

  13. General boundary conditions for quasiclassical theory of superconductivity in the diffusive limit: application to strongly spin-polarized systems

    NASA Astrophysics Data System (ADS)

    Eschrig, M.; Cottet, A.; Belzig, W.; Linder, J.

    2015-08-01

    Boundary conditions in quasiclassical theory of superconductivity are of crucial importance for describing proximity effects in heterostructures between different materials. Although they have been derived for the ballistic case in full generality, corresponding boundary conditions for the diffusive limit, described by Usadel theory, have been lacking for interfaces involving strongly spin-polarized materials, e.g. half-metallic ferromagnets. Given the current intense research in the emerging field of superconducting spintronics, the formulation of appropriate boundary conditions for the Usadel theory of diffusive superconductors in contact with strongly spin-polarized ferromagnets for arbitrary transmission probability and arbitrary spin-dependent interface scattering phases has been a burning open question. Here we close this gap and derive the full boundary conditions for quasiclassical Green functions in the diffusive limit, valid for any value of spin polarization, transmission probability, and spin-mixing angles (spin-dependent scattering phase shifts). Our formulation allows also for complex spin textures across the interface and for channel off-diagonal scattering (a necessary ingredient when the numbers of channels on the two sides of the interface differ). As an example we derive expressions for the proximity effect in diffusive systems involving half-metallic ferromagnets. In a superconductor/half-metal/superconductor Josephson junction we find {? }0-junction behavior under certain interface conditions.

  14. [Unequal living conditions and health chances in preschool children: support protective factors - limit risk factors].

    PubMed

    Horstkotte, E; Zimmermann, E

    2008-11-01

    Manifestations of an aggravation of social antagonisms and increased reports about childhood poverty and child abuse have unleashed a broad debate about the situation of children in risk-laden circumstances. More and more children are affected by relative poverty and disadvantage. An increase in the number children under 15 who receive social assistance can also be registered in Bremen, this share even increased to 60% in especially burdened districts. Against this background, the Bremen Health Department used a socio-spatial analysis to determine whether the utilisation of health examinations and the social and cultural participation chances of preschool children differed according to their living conditions. To this end, selected data from the school entrance examinations from 1998 to 2005 were analysed in regard to their relevance for the participation chances in different child-related dimensions of the life situation. Contradictory developments could be found, both in the dimension of the utilisation of health examinations and in the dimension of social and cultural participation chances. Children from disadvantaged neighbourhoods exhibited a lower utilisation of health examinations and less chances for social and cultural participation than children from more well-to-do residential areas. Trend calculations for the years 1998 to 2005 show an increasing discrepancy between children from disadvantaged and those from well-to-do neighbourhoods. Disadvantaged life situations - with the danger of increasing exclusion - appear to be establishing themselves in Bremen. The resources of children and families for dealing with risk-laden life situations have to be strengthened. Effective and long-lasting prevention approaches have to be developed and implemented at the local level. Kindergartens and schools could serve as centres for community networking strategies. Integrated concepts for action in the respective social areas are necessary to protect children and guarantee them fair chances despite disadvantaged living conditions. PMID:19039725

  15. Mutual information and the F-theorem

    NASA Astrophysics Data System (ADS)

    Casini, Horacio; Huerta, Marina; Myers, Robert C.; Yale, Alexandre

    2015-10-01

    Mutual information is used as a purely geometrical regularization of entanglement entropy applicable to any QFT. A coefficient in the mutual information between concentric circular entangling surfaces gives a precise universal prescription for the monotonous quantity in the c-theorem for d = 3. This is in principle computable using any regularization for the entropy, and in particular is a definition suitable for lattice models. We rederive the proof of the c-theorem for d = 3 in terms of mutual information, and check our arguments with holographic entanglement entropy, a free scalar field, and an extensive mutual information model.

  16. Constructing mutually unbiased bases in dimension six

    SciTech Connect

    Brierley, Stephen; Weigert, Stefan

    2009-05-15

    The density matrix of a qudit may be reconstructed with optimal efficiency if the expectation values of a specific set of observables are known. In dimension six, the required observables only exist if it is possible to identify six mutually unbiased complex (6x6) Hadamard matrices. Prescribing a first Hadamard matrix, we construct all others mutually unbiased to it, using algebraic computations performed by a computer program. We repeat this calculation many times, sampling all known complex Hadamard matrices, and we never find more than two that are mutually unbiased. This result adds considerable support to the conjecture that no seven mutually unbiased bases exist in dimension six.

  17. Conditions and limitations on learning in the adaptive management of mallard harvests

    USGS Publications Warehouse

    Johnson, F.A.; Kendall, W.L.; Dubovsky, J.A.

    2002-01-01

    In 1995, the United States Fish and Wildlife Service adopted a protocol for the adaptive management of waterfowl hunting regulations (AHM) to help reduce uncertainty about the magnitude of sustainable harvests. To date, the AHM process has focused principally on the midcontinent population of mallards (Anas platyrhynchos), whose dynamics are described by 4 alternative models. Collectively, these models express uncertainty (or disagreement) about whether harvest is an additive or a compensatory form of mortality and whether the reproductive process is weakly or strongly density-dependent. Each model is associated with a probability or 'weight,' which describes its relative ability to predict changes in population size. These Bayesian probabilities are updated annually using a comparison of population size predicted under each model with that observed by a monitoring program. The current AHM process is passively adaptive, in the sense that there is no a priori consideration of how harvest decisions might affect discrimination among models. We contrast this approach with an actively adaptive approach, in which harvest decisions are used in part to produce the learning needed to increase long-term management performance. Our investigation suggests that the passive approach is expected to perform nearly as well as an optimal actively adaptive approach, particularly considering the nature of the model set, management objectives and constraints, and current regulatory alternatives. We offer some comments about the nature of the biological hypotheses being tested and describe some of the inherent limitations on learning in the AHM process.

  18. On the choice of limiters in a numerical approximation of a chemotaxis system with non-linear boundary conditions

    NASA Astrophysics Data System (ADS)

    Bencheva, G.

    2012-10-01

    A mathematical model for haematopoietic stem cells migration towards their niche in the bone marrow has been proposed in the literature. It consists of a chemotaxis system of partial differential equations with nonlinear boundary conditions and an additional ordinary differential equation on a part of the computational boundary. The aim in the current paper is first to answer some of the open questions of a recently introduced finite volume scheme for this chemotaxis system of differential equations and second to investigate the influence of the boundary conditions on the choice of flux limiters (the generalized minmod, Koren, van Leer limiters are investigated) used to ensure positivity and non-oscillating nature of the numerical solution.

  19. Small rodent winter survival: snow conditions limit access to food resources.

    PubMed

    Korslund, Lars; Steen, Harald

    2006-01-01

    1. In Fennoscandia during winter small rodents spend most of their time in the subnivean space, between the snow cover and the ground. The subnivean space is probably not a uniform habitat, but broken into accessible and inaccessible patches by ice covering the vegetation. This might reduce access to otherwise available food resources. 2. To test whether ice formations reduce access to food and thus limit winter survival of small rodents, we conducted an experiment where we increased subnivean space by adding corrugated aluminium sheets on the ground before onset of winter. The sheets prevented ice formation, thus mimicking natural occurring subnivean space, and providing more room for animals living in the subnivean space to forage. 3. During the experiment 142 Microtus oeconomus were passive induced transponder (PIT)-tagged, and a system consisting of fixed tube-shaped antennas and PIT-tag readers were used to provide data to analyse winter survival and individual subnivean space use. The extent of winter grazing was measured after snow melt by examining percentage area grazed. 4. The treatment resulted in increased survival which corresponded well with significantly higher space use and more grazing under the sheets. 5. Females showed a positive correlation between probability of survival and body mass while no such effect was observed in males. 6. The results suggest that the snow cover reduces survival in winter by physically enclosing the vegetation in ice and thus reducing access to otherwise available food resources. The amount of ice and its configuration might vary between years due to changing weather patterns. Our results offer a mechanistic explanation for variations in winter survival and suggest incorporating climate variables in future small rodent models. 7. Directional and long-term changes in climate might result in increased ice formation in the subnivean system. Such deterioration may lead to reduced winter survival and act by stabilizing population dynamics and dampening vole cyclicity. PMID:16903053

  20. Determination of Bacterial Weathering Ability in Nutrient Limited Conditions on Biotite

    NASA Astrophysics Data System (ADS)

    Grant, M. R.; Harsh, J. B.

    2011-12-01

    Bacterial and fungal communities facilitate the weathering of minerals in oligotrophic soils. The bacterial communities reside in biofilms, consisting of extracellular polymeric substances (EPS) such as lipids, carbohydrates, proteins, and nuclei acids. Biotite, a 2:1 aluminosilicate mica, is a common primary mineral found in these low nutrient soils and is a source of potassium, magnesium and iron for both microorganisms and plants. Studies show that bacteria, when incubated with biotite flakes, can remove iron, potassium, and magnesium at higher quantities and increased rates compared to abiotic controls (Balogh-Brunstad et al., 2008; Calvaruso et al., 2006; Hopf et al. 2008; Uroz et al., 2007 and 2009). How this happens mechanistically is still unclear and this study seeks to shed light on this issue. We hypothesize that weathering by bacteria is selective; i.e., that the mechanism will depend on the limiting nutrient. Using a drip flow biofilm reactor, biofilms are grown on biotite coupons under non-turbulent, low sheer flow, with four different nutrient treatments. The nutrient treatments include a complete nutrient solution and the same solution without K, Mg, or Fe. In each treatment, we determine the concentration and cumulative release of each cation in the effluent. Congruent dissolution of biotite indicates that weathering is nonselective whereas incongruent dissolution suggests that the bacteria alter the weathering mechanism for a specific nutrient. The bacteria are selected from a bacterial inoculum collected from the roots of young White Pine (Pinus strobus) trees in the Saint Joseph National Forest, Idaho. The bacteria are isolated on plates and the best weathering species are selected using a microplate bioassay technique to determine the concentrations of K, Ca, Mg, and protons colorimetrically.

  1. Profiling of spatial metabolite distributions in wheat leaves under normal and nitrate limiting conditions.

    PubMed

    Allwood, J William; Chandra, Surya; Xu, Yun; Dunn, Warwick B; Correa, Elon; Hopkins, Laura; Goodacre, Royston; Tobin, Alyson K; Bowsher, Caroline G

    2015-07-01

    The control and interaction between nitrogen and carbon assimilatory pathways is essential in both photosynthetic and non-photosynthetic tissue in order to support metabolic processes without compromising growth. Physiological differences between the basal and mature region of wheat (Triticum aestivum) primary leaves confirmed that there was a change from heterotrophic to autotrophic metabolism. Fourier Transform Infrared (FT-IR) spectroscopy confirmed the suitability and phenotypic reproducibility of the leaf growth conditions. Principal Component-Discriminant Function Analysis (PC-DFA) revealed distinct clustering between base, and tip sections of the developing wheat leaf, and from plants grown in the presence or absence of nitrate. Gas Chromatography-Time of Flight/Mass Spectrometry (GC-TOF/MS) combined with multivariate and univariate analyses, and Bayesian network (BN) analysis, distinguished different tissues and confirmed the physiological switch from high rates of respiration to photosynthesis along the leaf. The operation of nitrogen metabolism impacted on the levels and distribution of amino acids, organic acids and carbohydrates within the wheat leaf. In plants grown in the presence of nitrate there was reduced levels of a number of sugar metabolites in the leaf base and an increase in maltose levels, possibly reflecting an increase in starch turnover. The value of using this combined metabolomics analysis for further functional investigations in the future are discussed. PMID:25680480

  2. Profiling of spatial metabolite distributions in wheat leaves under normal and nitrate limiting conditions

    PubMed Central

    Allwood, J. William; Chandra, Surya; Xu, Yun; Dunn, Warwick B.; Correa, Elon; Hopkins, Laura; Goodacre, Royston; Tobin, Alyson K.; Bowsher, Caroline G.

    2015-01-01

    The control and interaction between nitrogen and carbon assimilatory pathways is essential in both photosynthetic and non-photosynthetic tissue in order to support metabolic processes without compromising growth. Physiological differences between the basal and mature region of wheat (Triticum aestivum) primary leaves confirmed that there was a change from heterotrophic to autotrophic metabolism. Fourier Transform Infrared (FT-IR) spectroscopy confirmed the suitability and phenotypic reproducibility of the leaf growth conditions. Principal Component–Discriminant Function Analysis (PC–DFA) revealed distinct clustering between base, and tip sections of the developing wheat leaf, and from plants grown in the presence or absence of nitrate. Gas Chromatography-Time of Flight/Mass Spectrometry (GC-TOF/MS) combined with multivariate and univariate analyses, and Bayesian network (BN) analysis, distinguished different tissues and confirmed the physiological switch from high rates of respiration to photosynthesis along the leaf. The operation of nitrogen metabolism impacted on the levels and distribution of amino acids, organic acids and carbohydrates within the wheat leaf. In plants grown in the presence of nitrate there was reduced levels of a number of sugar metabolites in the leaf base and an increase in maltose levels, possibly reflecting an increase in starch turnover. The value of using this combined metabolomics analysis for further functional investigations in the future are discussed. PMID:25680480

  3. Kadanoff-Baym equations with non-Gaussian initial conditions: The equilibrium limit

    SciTech Connect

    Garny, Mathias; Mueller, Markus Michael

    2009-10-15

    The nonequilibrium dynamics of quantum fields is an initial-value problem, which can be described by Kadanoff-Baym equations. Typically, and, in particular, when numerical solutions are demanded, these Kadanoff-Baym equations are restricted to Gaussian initial states. However, physical initial states are non-Gaussian correlated initial states. In particular, renormalizability requires the initial state to feature n-point correlations that asymptotically agree with the vacuum correlations at short distances. In order to identify physical nonequilibrium initial states, it is therefore a precondition to describe the vacuum correlations of the interacting theory within the nonequilibrium framework. In this paper, Kadanoff-Baym equations for non-Gaussian correlated initial states describing vacuum and thermal equilibrium are derived from the 2PI effective action. A diagrammatic method for the explicit construction of vacuum and thermal initial correlations from the 2PI effective action is provided. We present numerical solutions of Kadanoff-Baym equations for a real scalar {phi}{sup 4} quantum field theory, which take the thermal initial four-point correlation as the leading non-Gaussian correction into account. We find that this minimal non-Gaussian initial condition yields an approximation to the complete equilibrium initial state that is quantitatively and qualitatively significantly improved as compared to Gaussian initial states.

  4. Comparative studies of S-layer proteins from Bacillus stearothermophilus strains expressed during growth in continuous culture under oxygen-limited and non-oxygen-limited conditions.

    PubMed Central

    Sára, M; Sleytr, U B

    1994-01-01

    The specific properties of S-layer proteins from three different Bacillus stearothermophilus strains revealing oblique, square, or hexagonal lattice symmetry were preserved during growth in continuous culture on complex medium only under oxygen-limited conditions in which glucose was used as the sole carbon source. When oxygen limitation was relieved, amino acids became metabolized, cell density increased, and different S-layer proteins from wild-type strains became rapidly replaced by a new common type of S-layer protein with an apparent subunit molecular weight of 97,000 which assembled into an identical oblique (p2) lattice type. During switching from wild-type strains to variants, patches of the S-layer lattices characteristics for wild-type strains, granular regions, and areas with oblique lattice symmetry could be observed on the surface of individual cells from all organisms. The granular regions apparently consisted of mixtures of the S-layer proteins from the wild-type strains and the newly synthesized p2 S-layer proteins from the variants. S-layer proteins from wild-type strains possessed identical N-terminal regions but led to quite different cleavage products upon peptide mapping, indicating that they are encoded by different genes. Chemical analysis including N-terminal sequencing and peptide mapping showed that the oblique S-layer lattices synthesized under increased oxygen supply were composed of identical protein species. Images PMID:7961489

  5. Burkholderia spp. are the most competitive symbionts of Mimosa, particularly under N-limited conditions.

    PubMed

    Elliott, Geoffrey N; Chou, Jui-Hsing; Chen, Wen-Ming; Bloemberg, Guido V; Bontemps, Cyril; Martínez-Romero, Esperanza; Velázquez, Encarna; Young, J Peter W; Sprent, Janet I; James, Euan K

    2009-04-01

    Bacteria isolated from Mimosa nodules in Taiwan, Papua New Guinea, Mexico and Puerto Rico were identified as belonging to either the alpha- or beta-proteobacteria. The beta-proteobacterial Burkholderia and Cupriavidus strains formed effective symbioses with the common invasive species Mimosa diplotricha, M. pigra and M. pudica, but the alpha-proteobacterial Rhizobium etli and R. tropici strains produced a range of symbiotic phenotypes from no nodulation through ineffective to effective nodulation, depending on Mimosa species. Competition studies were performed between three of the alpha-proteobacteria (R. etli TJ167, R. tropici NGR181 and UPRM8021) and two of the beta-rhizobial symbionts (Burkholderia mimosarum PAS44 and Cupriavidus taiwanensis LMG19424) for nodulation of these invasive Mimosa species. Under flooded conditions, B. mimosarum PAS44 out-competed LMG19424 and all three alpha-proteobacteria to the point of exclusion. This advantage was not explained by initial inoculum levels, rates of bacterial growth, rhizobia-rhizobia growth inhibition or individual nodulation rate. However, the competitive domination of PAS44 over LMG19424 was reduced in the presence of nitrate for all three plant hosts. The largest significant effect was for M. pudica, in which LMG19424 formed 57% of the nodules in the presence of 0.5 mM potassium nitrate. In this host, ammonium also had a similar, but lesser, effect. Comparable results were also found using an N-containing soil mixture, and environmental N levels are therefore suggested as a factor in the competitive success of the bacterial symbiont in vivo. PMID:19040456

  6. Language and Traits of Autism Spectrum Conditions: Evidence of Limited Phenotypic and Etiological Overlap

    PubMed Central

    Taylor, Mark J.; Charman, Tony; Robinson, Elise B.; Hayiou-Thomas, Marianna E.; Happé, Francesca; Dale, Philip S.; Ronald, Angelica

    2015-01-01

    Language difficulties have historically been viewed as integral to autism spectrum conditions (ASC), leading molecular genetic studies to consider whether ASC and language difficulties have overlapping genetic bases. The extent of genetic, and also environmental, overlap between ASC and language is, however, unclear. We hence conducted a twin study of the concurrent association between autistic traits and receptive language abilities. Internet-based language tests were completed by ~3,000 pairs of twins, while autistic traits were assessed via parent ratings. Twin model fitting explored the association between these measures in the full sample, while DeFries-Fulker analysis tested these associations at the extremes of the sample. Phenotypic associations between language ability and autistic traits were modest and negative. The degree of genetic overlap was also negative, indicating that genetic influences on autistic traits lowered language scores in the full sample (mean genetic correlation = ?0.13). Genetic overlap was also low at the extremes of the sample (mean genetic correlation = 0.14), indicating that genetic influences on quantitatively defined language difficulties were largely distinct from those on extreme autistic traits. Variation in language ability and autistic traits were also associated with largely different nonshared environmental influences. Language and autistic traits are influenced by largely distinct etiological factors. This has implications for molecular genetic studies of ASC and understanding the etiology of ASC. Additionally, these findings lend support to forthcoming DSM-5 changes to ASC diagnostic criteria that will see language difficulties separated from the core ASC communication symptoms, and instead listed as a clinical specifier. PMID:25088445

  7. Language and traits of autism spectrum conditions: evidence of limited phenotypic and etiological overlap.

    PubMed

    Taylor, Mark J; Charman, Tony; Robinson, Elise B; Hayiou-Thomas, Marianna E; Happé, Francesca; Dale, Philip S; Ronald, Angelica

    2014-10-01

    Language difficulties have historically been viewed as integral to autism spectrum conditions (ASC), leading molecular genetic studies to consider whether ASC and language difficulties have overlapping genetic bases. The extent of genetic, and also environmental, overlap between ASC and language is, however, unclear. We hence conducted a twin study of the concurrent association between autistic traits and receptive language abilities. Internet-based language tests were completed by ~3,000 pairs of twins, while autistic traits were assessed via parent ratings. Twin model fitting explored the association between these measures in the full sample, while DeFries-Fulker analysis tested these associations at the extremes of the sample. Phenotypic associations between language ability and autistic traits were modest and negative. The degree of genetic overlap was also negative, indicating that genetic influences on autistic traits lowered language scores in the full sample (mean genetic correlation = -0.13). Genetic overlap was also low at the extremes of the sample (mean genetic correlation = 0.14), indicating that genetic influences on quantitatively defined language difficulties were largely distinct from those on extreme autistic traits. Variation in language ability and autistic traits were also associated with largely different nonshared environmental influences. Language and autistic traits are influenced by largely distinct etiological factors. This has implications for molecular genetic studies of ASC and understanding the etiology of ASC. Additionally, these findings lend support to forthcoming DSM-5 changes to ASC diagnostic criteria that will see language difficulties separated from the core ASC communication symptoms, and instead listed as a clinical specifier. PMID:25088445

  8. Arsenic-induced phosphate limitation under experimental Early Proterozoic oceanic conditions

    NASA Astrophysics Data System (ADS)

    Chi Fru, Ernest; Hemmingsson, Christoffer; Holm, Mikaela; Chiu, Beverly; Iñiguez, Enrique

    2016-01-01

    Comparison of phosphorus concentrations associated with modern hydrothermal Fe(III)(oxyhydr)oxides and ancient Fe(III) oxide-rich iron formations, is used to estimate bioavailable Precambrian marine phosphorus (P) concentrations. This led to the proposition of a low dissolved P budget of ˜10-25% of present-day levels, before ˜1.9 billion years ago. Estimates incorporating ancient marine Si levels ≥ 0.67 mM instead suggested global dissolved P levels greater than today. Here we unite current experimental models that have considered NaCl solutions containing elevated dissolved Fe(II), Si, Ca2+ and Mg2+ ions in the incorporation of P in Precambrian marine Fe(III)(oxyhydr)oxides, in addition to arsenic as a hydrothermal proxy. We show that the coprecipitation of dissolved P and Fe(III)(oxyhydr)oxides from arsenic-rich marine waters produces an average P distribution coefficient of ˜0.072 (± 0.01) μM-1. This is comparable to the ˜ 0.07 μM-1 predicted for Fe(III)(oxyhydr)oxides in modern arsenic-rich, submarine hydrothermal settings, from which the lower Early Proterozoic dissolved marine P concentrations were predicted. As/P molar ratios below modern seawater ratios removed the negative feedback effect high Si impose on P scavenging by Fe(III)(oxyhydr)oxides. The binding of As(III) to Fe(III)(oxyhydr)oxides exhibits a lower competitive influence on P fixation. As(V) that likely became prominent in the surficially oxidized Early Proterozoic oceans induced dissolved P limitation because of preferential P sequestration at the expense of dissolved As(V) enrichment. The control of As on P scavenging by the precipitating Fe(III)(oxyhydr)oxides is strong regardless of common seawater cations (Mg2+ and Ca2+). The data suggest that the application of Si and Fe(III)(oxyhydr)oxides as an ancient seawater P proxy should consider chemical variability between depositional basins, taking into account the rather strong role hydrothermal arsenic has on the distribution of P in Fe(III)(oxyhydr)oxides. We propose that the generalized lower dissolved P budgets estimated from Early Proterozoic iron formations are consistent with oceans thought to be at least 3-4 times more hydrothermally active than at present.

  9. Doppler-broadened NICE-OHMS beyond the cavity-limited weak absorption condition - II: Experimental verification

    NASA Astrophysics Data System (ADS)

    Hausmaninger, Thomas; Silander, Isak; Ma, Weiguang; Axner, Ove

    2016-01-01

    Doppler-broadened (Db) noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) is normally described by an expression, here termed the conventional (CONV) description, that is restricted to the conventional cavity-limited weak absorption condition (CCLWA), i.e. when the single pass absorbance is significantly smaller than the empty cavity losses, i.e. when α0 L < < π / F. To describe NICE-OHMS signals beyond this limit two simplified extended descriptions (termed the extended locking and extended transmission description, ELET, and the extended locking and full transmission description, ELFT), which are assumed to be valid under the relaxed cavity-limited weak absorption condition (RCLWA), i.e. when α0 L < π / F, and a full description (denoted FULL), presumed to be valid also when the α0 L < π / F condition does not hold, have recently been derived in an accompanying work (Ma W, et al. Doppler-broadened NICE-OHMS beyond the cavity-limited weak absorption condition - I. Theoretical Description. J Quant Spectrosc Radiat Transfer, 2015, http://dx.doi.org/10.1016/j.jqsrt.2015.09.007). The present work constitutes an experimental verification and assessment of the validity of these, performed in the Doppler limit for a set of Fα0 L / π values (up to 3.5); it is shown under which conditions the various descriptions are valid. It is concluded that for samples with Fα0 L / π up to 0.01, all descriptions replicate the data well. It is shown that the CONV description is adequate and provides accurate assessments of the signal strength (and thereby the analyte concentration) up to Fα0 L / π of around 0.1, while the ELET is accurate for Fα0 L / π up to around 0.3. The ELFT description mimics the Db NICE-OHMS signal well for Fα0 L / π up to around unity, while the FULL description is adequate for all Fα0 L / π values investigated. Access to these descriptions both increases considerably the dynamic range of the technique and facilitates calibration using certified reference gases, which thereby significantly broadens the applicability of the Db NICE-OHMS technique.

  10. Benefits and limitations of pig slurry to reclaim bare mine soils under Mediterranean semiarid conditions

    NASA Astrophysics Data System (ADS)

    Zornoza, Raúl; Faz, Ángel; Acosta, Jose A.; Kabas, Sebla; Martínez-Martínez, Silvia; Ángeles Muñoz, M.

    2013-04-01

    In this study, the effects of pig slurry application on reclamation of mine soils from Cartagena-La Unión Mining District (SE Spain) were investigated in a field experiment. Exchangeable metals (Cd, Cu, Pb and Zn), total organic carbon, total nitrogen, soluble carbon, microbial biomass and three enzyme activities were periodically monitored during 67 days. In addition, one year after the application of the pig slurry, soil and developed vegetation was sampled. Results showed that only exchangeable Cd and Zn significantly decreased in the amended plots, mainly for Cd, with decreases of 98%. The rest of metals and chemical properties did not change with time after application of amendments, showing values not significantly different than those present before pig slurry application. Soluble carbon, microbial biomass carbon and the enzyme activities increased after the application of pig slurry. However, after various days these parameters started a decreasing trend until reaching values similar to the control from approximately day 25. Thus, mainly precipitation as phosphate from the waste was very effective for Cd immobilization. No increments were observed in soil organic carbon because the organic carbon applied with the slurry was too low to be significantly detected. Nonetheless, pig slurry is a good fertilizer owing to the high quantity of nutrients provided, needed to promote the development of vegetation. One year after application, a native vegetation cover (25-30%) was reached by spontaneous colonization. Triggered plant growth by the effect of amendment improved soil conditions, particularly by the help of the medium created by their rhizosphere systems. Increments in soil organic carbon and total nitrogen, and decreases in the exchangeable metals fraction concentration were observed in rhizospheric soils when compared to the bare soils. This improvement in soil quality mediated by vegetation was more efficient than the direct effect of the amendment. In conclusion, the use of pig slurry to reclaim bare contaminated soils by heavy metals brings indirect positive effects by triggering a vegetation cover which can stabilize metals and increase soil quality (phytostabilization). Keywords: heavy metals, microbial biomass, enzyme activities, phytoremediation.

  11. 3D scalar model as a 4D perfect conductor limit: Dimensional reduction and variational boundary conditions

    SciTech Connect

    Edery, Ariel; Graham, Noah; MacDonald, Ilana

    2009-06-15

    Under dimensional reduction, a system in D spacetime dimensions will not necessarily yield its D-1-dimensional analog version. Among other things, this result will depend on the boundary conditions and the dimension D of the system. We investigate this question for scalar and Abelian gauge fields under boundary conditions that obey the symmetries of the action. We apply our findings to the Casimir piston, an ideal system for detecting boundary effects. Our investigation is not limited to extra dimensions and we show that the original piston scenario proposed in 2004, a toy model involving a scalar field in 3D (2+1) dimensions, can be obtained via dimensional reduction from a more realistic 4D electromagnetic (EM) system. We show that for perfect conductor conditions, a D-dimensional EM field reduces to a D-1 scalar field and not its lower-dimensional version. For Dirichlet boundary conditions, no theory is recovered under dimensional reduction and the Casimir pressure goes to zero in any dimension. This ''zero Dirichlet'' result is useful for understanding the EM case. We then identify two special systems where the lower-dimensional version is recovered in any dimension: systems with perfect magnetic conductor (PMC) and Neumann boundary conditions. We show that these two boundary conditions can be obtained from a variational procedure in which the action vanishes outside the bounded region. The fields are free to vary on the surface and have zero modes, which survive after dimensional reduction.

  12. Problem decomposition by mutual information and force-based clustering

    NASA Astrophysics Data System (ADS)

    Otero, Richard Edward

    The scale of engineering problems has sharply increased over the last twenty years. Larger coupled systems, increasing complexity, and limited resources create a need for methods that automatically decompose problems into manageable sub-problems by discovering and leveraging problem structure. The ability to learn the coupling (inter-dependence) structure and reorganize the original problem could lead to large reductions in the time to analyze complex problems. Such decomposition methods could also provide engineering insight on the fundamental physics driving problem solution. This work forwards the current state of the art in engineering decomposition through the application of techniques originally developed within computer science and information theory. The work describes the current state of automatic problem decomposition in engineering and utilizes several promising ideas to advance the state of the practice. Mutual information is a novel metric for data dependence and works on both continuous and discrete data. Mutual information can measure both the linear and non-linear dependence between variables without the limitations of linear dependence measured through covariance. Mutual information is also able to handle data that does not have derivative information, unlike other metrics that require it. The value of mutual information to engineering design work is demonstrated on a planetary entry problem. This study utilizes a novel tool developed in this work for planetary entry system synthesis. A graphical method, force-based clustering, is used to discover related sub-graph structure as a function of problem structure and links ranked by their mutual information. This method does not require the stochastic use of neural networks and could be used with any link ranking method currently utilized in the field. Application of this method is demonstrated on a large, coupled low-thrust trajectory problem. Mutual information also serves as the basis for an alternative global optimizer, called MIMIC, which is unrelated to Genetic Algorithms. Advancement to the current practice demonstrates the use of MIMIC as a global method that explicitly models problem structure with mutual information, providing an alternate method for globally searching multi-modal domains. By leveraging discovered problem inter- dependencies, MIMIC may be appropriate for highly coupled problems or those with large function evaluation cost. This work introduces a useful addition to the MIMIC algorithm that enables its use on continuous input variables. By leveraging automatic decision tree generation methods from Machine Learning and a set of randomly generated test problems, decision trees for which method to apply are also created, quantifying decomposition performance over a large region of the design space.

  13. Mutualisms and Population Regulation: Mechanism Matters

    PubMed Central

    Jha, Shalene; Allen, David; Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2012-01-01

    For both applied and theoretical ecological science, the mutualism between ants and their hemipteran partners is iconic. In this well-studied interaction, ants are assumed to provide hemipterans protection from natural enemies in exchange for nutritive honeydew. Despite decades of research and the potential importance in pest control, the precise mechanism producing this mutualism remains contested. By analyzing maximum likelihood parameter estimates of a hemipteran population model, we show that the mechanism of the mutualism is direct, via improved hemipteran growth rates, as opposed to the frequently assumed indirect mechanism, via harassment of the specialist parasites and predators of the hemipterans. Broadly, this study demonstrates that the management of mutualism-based ecosystem services requires a mechanistic understanding of mutualistic interactions. A consequence of this finding is the counter intuitive demonstration that preserving ant participation in the ant-hemipteran mutualism may be the best way of insuring pest control. PMID:22927978

  14. Mutual Orbits of Transneptunian Binaries

    NASA Astrophysics Data System (ADS)

    Grundy, William M.; Noll, K. S.; Roe, H. G.; Porter, S. B.; Trujillo, C. A.; Benecchi, S. D.; Buie, M. W.

    2012-10-01

    We report the latest results from a program of high spatial resolution imaging to resolve the individual components of binary transneptunian objects. These observations use Hubble Space Telescope and also laser guide star adaptive optics systems on Keck and Gemini telescopes on Mauna Kea. From relative astrometry over multiple epochs, we determine the mutual orbits of the components, and thus the total masses of the systems. Accurate masses anchor subsequent detailed investigations into the physical characteristics of these systems. For instance, dynamical masses enable computation of bulk densities for systems where the component sizes can be estimated from other measurements. Additionally, patterns in the ensemble characteristics of binary orbits offer clues to circumstances in the protoplanetary nebula when these systems formed, as well as carrying imprints of various subsequent dynamical evolution processes. The growing ensemble of known orbits shows intriguing patterns that can shed light on the evolution of this population of distant objects. This work has been supported by an NSF Planetary Astronomy grant and by several Hubble Space Telescope and NASA Keck data analysis grants. The research makes use of data from the Gemini Observatory obtained through NOAO survey program 11A-0017, from a large number of Hubble Space Telescope programs, and from several NASA Keck programs.

  15. The behavior of fuel-lean premixed flames in a standard flammability limit tube under controlled gravity conditions

    NASA Technical Reports Server (NTRS)

    Wherley, B. L.; Strehlow, R. A.

    1986-01-01

    Fuel-lean flames in methane-air mixtures from 4.90 to 6.20 volume percent fuel and propane-air mixtures from 1.90 to 3.00 volume percent fuel were studied in the vicinity of the limit for a variety of gravity conditions. The limits were determined and the behavior of the flames studied for one g upward, one g downward, and zero g propagation. Photographic records of all flammability tube firings were obtained. The structure and behavior of these flames were detailed including the variations of the curvature of the flame front, the skirt length, and the occurrence of cellular instabilities with varying gravity conditions. The effect of ignition was also discussed. A survey of flame speeds as a function of mixture strength was made over a range of lean mixture compositions for each of the fuels studied. The results were presented graphically with those obtained by other researchers. The flame speed for constant fractional gravity loadings were plotted as a function of gravity loadings from 0.0 up to 2.0 g's against flame speeds extracted from the transient gravity flame histories for corresponding gravity loadings. The effects of varying gravity conditions on the extinguishment process for upward and downward propagating flames were investigated.

  16. Towards lag phase of microbial populations at growth-limiting conditions: The role of the variability in the growth limits of individual cells.

    PubMed

    Aguirre, Juan S; Koutsoumanis, Konstantinos P

    2016-05-01

    The water activity (aw) growth limits of unheated and heat stressed Listeria monocytogenes individual cells were studied. The aw limits varied from 0.940 to 0.997 and 0.951 to 0.997 for unheated and heat stressed cells, respectively. Due to the above variability a decrease in aw results in the presence of a non-growing fraction in the population leading to an additional pseudo-lag in population growth. In this case the total apparent lag of the population is the sum of the physiological lag of the growing cells (time required to adjust to the new environment) and the pseudo-lag. To investigate the effect of aw on the above lag components, the growth kinetics of L. monocytogenes on tryptone soy agar with aw adjusted to values ranging from 0.997 to 0.940 was monitored. The model of B&R was fitted to the data for the estimation of the apparent lag. In order to estimate the physiological lag of the growing fraction of the inoculum, the model was refitted to the growth data using as initial population level the number of cells that were able to grow (estimated from the number of colonies formed on the agar at the end of storage) and excluding the rest data during the lag. The results showed that for the unheated cells the apparent lag was almost identical to the physiological lag for aw values ranging from 0.997 to 0.970, as the majority of the cells in the initial population was able to grow in these conditions. As the aw decreased from 0.970 to 0.940 however, the number of cells in the population which were able to grow, decreased resulting to an increase in the pseudo-lag. The maximum value of pseudo-lag was 13.1h and it was observed at aw=0.940 where 10% of the total inoculated cells were able to grow. For heat stressed populations a pseudo-lag started to increase at higher aw conditions (0.982) compared to unheated cells. In contrast to the apparent lag, a linear relation between physiological lag and aw was observed for both unheated and heat stressed cells. PMID:26900994

  17. Functional analysis of mutual behavior in laboratory rats (Rattus norvegicus).

    PubMed

    Tan, Lavinia; Hackenberg, Timothy D

    2016-02-01

    Three pairs of rats were trained to synchronize their lever pressing according to a mutual reinforcement contingency, in which alternating lever presses that fell within a 500-ms window were reinforced with food. In Experiment 1, rats worked in adjacent chambers separated by a transparent barrier, and the effects of the mutual reinforcement contingency were compared with those under yoked-control conditions that provided the same rate of food reinforcement but without the temporal coordination response requirement. In Experiment 2, coordinated behavior was compared with and without a barrier, and across different barrier types: transparent, opaque, wire mesh. In Experiment 3, the effects of social familiarity were assessed by switching partners, enabling a comparison of coordinated behavior with familiar and unfamiliar partners. The overall pattern of results shows that the coordinated behavior of 2 rats was (a) maintained by mutual reinforcement contingencies, (b) unrelated to the type or presence of a barrier separating the rats, and (c) sufficiently flexible to adjust to the presence and behavior of an unfamiliar partner. Taken as a whole, the study illustrates a promising approach to conceptualizing and analyzing behavioral mechanisms of mutual behavior, an important component of an integrated study of social behavior. (PsycINFO Database Record PMID:26479279

  18. Functional analysis of mutual behavior in laboratory rats (Rattus norvegicus)

    PubMed Central

    Tan, Lavinia; Hackenberg, Timothy D.

    2015-01-01

    Three pairs of rats were trained to synchronize their lever pressing according to a mutual reinforcement contingency, in which alternating lever presses that fell within a 500-ms window were reinforced with food. In Experiment 1, rats worked in adjacent chambers separated by a transparent barrier, and the effects of the mutual reinforcement contingency were compared to those under yoked-control conditions that provided the same rate of food reinforcement but without the temporal coordination response requirement. In Experiment 2, coordinated behavior was compared with and without a barrier, and across different barrier types: transparent, opaque, wire mesh. In Experiment 3, the effects of social familiarity were assessed by switching partners, enabling a comparison of coordinated behavior with familiar and unfamiliar partners. The overall pattern of results shows that the coordinated behavior of two rats was (a) maintained by mutual reinforcement contingencies, (b) unrelated to the type or presence of a barrier separating the rats, and (c) sufficiently flexible to adjust to the presence and behavior of an unfamiliar partner. Taken as a whole, the study illustrates a promising approach to conceptualizing and analyzing behavioral mechanisms of mutual behavior, an important component of an integrated study of social behavior. PMID:26479279

  19. Carbon isotopic fractionation by the marine diatom Phaeodactylum tricornutum under nutrient- and light-limited growth conditions

    NASA Astrophysics Data System (ADS)

    Cassar, Nicolas; Laws, Edward A.; Popp, Brian N.

    2006-11-01

    A theoretical model was developed to explain the characteristics of carbon isotopic fractionation ( ?P) by the marine diatom Phaeodactylum tricornutum under nutrient- and light-limited growth conditions. The model takes into consideration active transport and diffusion of inorganic carbon through the cell membrane and chloroplast membrane and the energetic tradeoff between production of Rubisco and operation of a carbon-concentrating mechanism to achieve a given growth rate. The model is able to explain 88% of the variance in experimental ?p data reported in this study and in previous work and is able to account for the observed pattern of Rubisco activity in nitrate-limited chemostats. Two important implications of the model include the fact that ?p is not a unique function of the ratio of growth rate to external CO 2 concentration (as opposed to the predictions of several previous models) and that changes in light-limited and nutrient-limited growth rates have opposite effects on the fraction of CO 2 taken up by the chloroplast that is lost to diffusion and hence on certain patterns of carbon isotopic fractionation.

  20. Conflicting selection in the course of adaptive diversification: the interplay between mutualism and intraspecific competition.

    PubMed

    Raimundo, Rafael L G; Gibert, Jean P; Hembry, David H; Guimarães, Paulo R

    2014-03-01

    Adaptive speciation can occur when a population undergoes assortative mating and disruptive selection caused by frequency-dependent intraspecific competition. However, other interactions, such as mutualisms based on trait matching, may generate conflicting selective pressures that constrain species diversification. We used individual-based simulations to explore how different types of mutualism affect adaptive diversification. A magic trait was assumed to simultaneously mediate mate choice, intraspecific competition, and mutualisms. In scenarios of intimate, specialized mutualisms, individuals interact with one or few individual mutualistic partners, and diversification is constrained only if the mutualism is obligate. In other scenarios, increasing numbers of different partners per individual limit diversification by generating stabilizing selection. Stabilizing selection emerges from the greater likelihood of trait mismatches for rare, extreme phenotypes than for common intermediate phenotypes. Constraints on diversification imposed by increased numbers of partners decrease if the trait matching degree has smaller positive effects on fitness. These results hold after the relaxation of various assumptions. When trait matching matters, mutualism-generated stabilizing selection would thus often constrain diversification in obligate mutualisms, such as ant-myrmecophyte associations, and in low-intimacy mutualisms, including plant-seed disperser systems. Hence, different processes, such as trait convergence favoring the incorporation of nonrelated species, are needed to explain the higher richness of low-intimacy assemblages--shown here to be up to 1 order of magnitude richer than high-intimacy systems. PMID:24561599

  1. Assessing the Influence of Lateral Boundary Conditions in Limited Area Numerical Weather Prediction Modelling for the Territory of Latvia

    NASA Astrophysics Data System (ADS)

    S?le, Tija; Se??ikovs, Juris; Bethers, Uldis

    2013-04-01

    Increase in available computing power has allowed even more research centres to begin work on atmospheric modelling and Numerical Weather Prediction (NWP). When Limited Area Models (LAM) are used, the possible influence of boundary conditions must be taken into account for sufficient analysis of the modelling results. However, there is no universally applicable approach and the analysis must be performed for each domain setup. The Weather Research and Forecast (WRF) model [1] is currently used in University of Latvia for research in NWP. The region of interest is the territory of Latvia that is situated in the North-Eastern part of Europe and on the Eastern shore of the Baltic Sea. The terrain is relatively flat (highest elevation ~ 300 m ASL). The climate of Latvia is hemiboreal (Dfb) according to the Köppen classification. In the winter the climate is strongly influenced by mid-latitude cyclones. The target computational domain covers the territory of Latvia with the resolution of 3 km (301x301 grid points) and is nested in a lower-resolution outer computational domain. The aim of this study is to assess the uncertainty that is caused by the choice of the computational domain and consequently the influence of the applied boundary conditions. Due to the limited computational resources selected events characteristic of different meteorological conditions are chosen for investigation. Several aspects are analysed such as: (1) domain sizes (2) positioning of the domains (with the aim of better cyclone description) and (3) boundary condition data sources (4) influence of the model spin-up times. The results are compared with the surface meteorological observations from the Latvian Environment, Geology and Meteorology Centre (LEGMC) observational network. References: [1] Skamarock, William C. and Klemp, Joseph B. A time-split nonhydrostatic atmospheric model for weather research and forecasting applications. Journal of Computational Physics. 227, 2008, pp. 3465-3485.

  2. Simulating Biodegradation Under Mixing-limited Conditions Using Michaelis-Menten (Monod) Kinetic Expressions in a Particle Tracking Model

    NASA Astrophysics Data System (ADS)

    Ding, D.; Benson, D. A.

    2014-12-01

    Recent studies have demonstrated that the typical method of adding mass-action reaction terms to the advection-dispersion equation overestimates the field-scale reaction rates. The mismatch is usually attributed to poor mixing. A recent method, based on a purely Langragian particle tracking (PT) theoretical development, successfully reproduces the results of mixing-limited bimolecular reaction (A+B ? C) from two benchmark experiments. In this numerical method, the reactants are represented by particles. The reactions are determined by a combination of two probabilities that govern whether: 1) reactant particles are collocated during a short time interval, and 2) two collocated particles favorably transform into a reaction. We extend the application of the PT method to biodegradation, which is commonly characterized by more complex Michaelis-Menten (Monod) chemical kinetics. The advantage of the PT method is that it explains the variation of reaction rate based on mixing-controlled particle collisions instead of using empirical parameters. The PT method is not only able to match the Michaelis-Menten (Monod) equation under ideal conditions, but also is able to capture the characteristics of non-ideal conditions such as imperfect mixing, disequilibrium, and limited availability of the active sites. Furthermore, for the ultimate goal of applying the Langragian PT method directly to the field scale problems, this method is implemented to the simulation of carbon tetrachloride (CT) biodegradation at the Schoolcraft, Michigan, site, where the hydraulic properties and reaction kinetics are well understood.

  3. Oxygen Response of the Wine Yeast Saccharomyces cerevisiae EC1118 Grown under Carbon-Sufficient, Nitrogen-Limited Enological Conditions

    PubMed Central

    Aceituno, Felipe F.; Orellana, Marcelo; Torres, Jorge; Mendoza, Sebastián; Slater, Alex W.; Melo, Francisco

    2012-01-01

    Discrete additions of oxygen play a critical role in alcoholic fermentation. However, few studies have quantitated the fate of dissolved oxygen and its impact on wine yeast cell physiology under enological conditions. We simulated the range of dissolved oxygen concentrations that occur after a pump-over during the winemaking process by sparging nitrogen-limited continuous cultures with oxygen-nitrogen gaseous mixtures. When the dissolved oxygen concentration increased from 1.2 to 2.7 μM, yeast cells changed from a fully fermentative to a mixed respirofermentative metabolism. This transition is characterized by a switch in the operation of the tricarboxylic acid cycle (TCA) and an activation of NADH shuttling from the cytosol to mitochondria. Nevertheless, fermentative ethanol production remained the major cytosolic NADH sink under all oxygen conditions, suggesting that the limitation of mitochondrial NADH reoxidation is the major cause of the Crabtree effect. This is reinforced by the induction of several key respiratory genes by oxygen, despite the high sugar concentration, indicating that oxygen overrides glucose repression. Genes associated with other processes, such as proline uptake, cell wall remodeling, and oxidative stress, were also significantly affected by oxygen. The results of this study indicate that respiration is responsible for a substantial part of the oxygen response in yeast cells during alcoholic fermentation. This information will facilitate the development of temporal oxygen addition strategies to optimize yeast performance in industrial fermentations. PMID:23001663

  4. A Comparison Between the Burn Condition of Deuterium-Tritium and Deuterium-Helium-3 Reaction and Stability Limits

    NASA Astrophysics Data System (ADS)

    Motevalli, Seyed Mohammad; Fadaei, Fereshteh

    2015-02-01

    The nuclear reaction of deuterium-tritium (D-T) fusion by the usual magnetic or inertial confinement suffers from a number of difficulties and problems caused by tritium handling, neutron damage to materials and neutron-induced radioactivity, etc. The study of the nuclear synthesis reaction of deuterium-helium-3 (D-3He) at low collision energies (below 1 keV) is of interest for its applications in nuclear physics and astrophysics. Spherical tokamak (ST) reactors have a low aspect ratio and can confine plasma with ??1. These capabilities of ST reactors are due to the use of the alternative D-3He reaction. In this work, the burn condition of D-3He reaction was calculated by using zero-dimensional particles and power equations, and, with the use of the parameters of the ST reactor, the stability limit of D-3He reaction was calculated and then the results were compared with those of D-T reaction. The obtained results show that the burn conditions of D-3He reaction required a higher temperature and had a much more limited temperature range in comparison to those of D-T reaction.

  5. Competition for cellobiose among three predominant ruminal cellulolytic bacteria under substrate-excess and substrate-limited conditions.

    PubMed Central

    Shi, Y; Weimer, P J

    1997-01-01

    The ruminal cellulolytic bacteria Ruminococcus flavefaciens FD-1 and Fibrobacter succinogenes S85 coexisted in substrate-excess coculture with about equal population size, but R. flavefaciens outcompeted F. succinogenes for cellobiose in the substrate-limited cocultures whether the two strains were coinoculated or a steady-state culture of F. succinogenes was challenged by R. flavefaciens. This outcome of competition between these two strains is due to a classical pure and simple competition mechanism based on affinity for cellobiose. Although the population size of F. succinogenes was much higher (> 70%) than that of another cellulolytic species, Ruminococcus albus 7 in substrate-excess coculture, F. succinogenes was replaced by a population of R. albus in the substrate-limited coculture in both coinoculation and challenge experiments. R albus outcompeted F. succinogenes, apparently due to selection in the chemostat of a population of R. albus with a higher affinity for cellobiose. R. albus also outcompeted R. flavefaciens under substrate-limited conditions. PMID:9023951

  6. Current Guidelines Have Limited Applicability to Patients with Comorbid Conditions: A Systematic Analysis of Evidence-Based Guidelines

    PubMed Central

    Lugtenberg, Marjolein; Burgers, Jako S.; Clancy, Carolyn; Westert, Gert P.; Schneider, Eric C.

    2011-01-01

    Background Guidelines traditionally focus on the diagnosis and treatment of single diseases. As almost half of the patients with a chronic disease have more than one disease, the applicability of guidelines may be limited. The aim of this study was to assess the extent that guidelines address comorbidity and to assess the supporting evidence of recommendations related to comorbidity. Methodology/Principal Findings We conducted a systematic analysis of evidence-based guidelines focusing on four highly prevalent chronic conditions with a high impact on quality of life: chronic obstructive pulmonary disease, depressive disorder, diabetes mellitus type 2, and osteoarthritis. Data were abstracted from each guideline on the extent that comorbidity was addressed (general comments, specific recommendations), the type of comorbidity discussed (concordant, discordant), and the supporting evidence of the comorbidity-related recommendations (level of evidence, translation of evidence). Of the 20 guidelines, 17 (85%) addressed the issue of comorbidity and 14 (70%) provided specific recommendations on comorbidity. In general, the guidelines included few recommendations on patients with comorbidity (mean 3 recommendations per guideline, range 0 to 26). Of the 59 comorbidity-related recommendations provided, 46 (78%) addressed concordant comorbidities, 8 (14%) discordant comorbidities, and for 5 (8%) the type of comorbidity was not specified. The strength of the supporting evidence was moderate for 25% (15/59) and low for 37% (22/59) of the recommendations. In addition, for 73% (43/59) of the recommendations the evidence was not adequately translated into the guidelines. Conclusions/Significance Our study showed that the applicability of current evidence-based guidelines to patients with comorbid conditions is limited. Most guidelines do not provide explicit guidance on treatment of patients with comorbidity, particularly for discordant combinations. Guidelines should be more explicit about the applicability of their recommendations to patients with comorbidity. Future clinical trials should also include patients with the most prevalent combinations of chronic conditions. PMID:22028802

  7. Potassium Transporter KUP7 Is Involved in K(+) Acquisition and Translocation in Arabidopsis Root under K(+)-Limited Conditions.

    PubMed

    Han, Min; Wu, Wei; Wu, Wei-Hua; Wang, Yi

    2016-03-01

    Potassium (K(+)) is one of the essential macronutrients for plant growth and development. K(+) uptake from environment and K(+) translocation in plants are conducted by K(+) channels and transporters. In this study, we demonstrated that KT/HAK/KUP transporter KUP7 plays crucial roles in K(+) uptake and translocation in Arabidopsis root. The kup7 mutant exhibited a sensitive phenotype on low-K(+) medium, whose leaves showed chlorosis symptoms compared with wild-type plants. Loss of function of KUP7 led to a reduction of K(+) uptake rate and K(+) content in xylem sap under K(+)-deficient conditions. Thus, the K(+) content in kup7 shoot was significantly reduced under low-K(+) conditions. Localization analysis revealed that KUP7 was predominantly targeted to the plasma membrane. The complementation assay in yeast suggested that KUP7 could mediate K(+) transport. In addition, phosphorylation on S80, S719, and S721 was important for KUP7 activity. KUP7 was ubiquitously expressed in many organs/tissues, and showed a higher expression level in Arabidopsis root. Together, our data demonstrated that KUP7 is crucial for K(+) uptake in Arabidopsis root and might be also involved in K(+) transport into xylem sap, affecting K(+) translocation from root toward shoot, especially under K(+)-limited conditions. PMID:26851373

  8. Static and adaptive feedback control for synchronization of different chaotic oscillators with mutually Lipschitz nonlinearities

    NASA Astrophysics Data System (ADS)

    Muhammad, Riaz; Muhammad, Rehan; Keum-Shik, Hong; Muhammad, Ashraf; Haroon, Ur Rasheed

    2014-11-01

    This paper addresses the control law design for synchronization of two different chaotic oscillators with mutually Lipschitz nonlinearities. For analysis of the properties of two different nonlinearities, an advanced mutually Lipschitz condition is proposed. This mutually Lipschitz condition is more general than the traditional Lipschitz condition. Unlike the latter, it can be used for the design of a feedback controller for synchronization of chaotic oscillators of different dynamics. It is shown that any two different Lipschitz nonlinearities always satisfy the mutually Lipschitz condition. Applying the mutually Lipschitz condition, a quadratic Lyapunov function and uniformly ultimately bounded stability, easily designable and implementable robust control strategies utilizing algebraic Riccati equation and linear matrix inequalities, are derived for synchronization of two distinct chaotic oscillators. Furthermore, a novel adaptive control scheme for mutually Lipschitz chaotic systems is established by addressing the issue of adaptive cancellation of unknown mismatch between the dynamics of different chaotic systems. The proposed control technique is numerically tested for synchronization of two different chaotic Chua's circuits and for obtaining identical behavior between the modified Chua's circuit and the Rössler system.

  9. 76 FR 36625 - Mutual Holding Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... collection. Title of Proposal: Mutual Holding Company. OMB Number: 1550-0072. Form Numbers: MHC-1 (OTS Form 1522) and MHC-2 (OTS Form 1523). Description: The OTS analyzes the submitted information to...

  10. 76 FR 20458 - Mutual Holding Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... collection. Title of Proposal: Mutual Holding Company. OMB Number: 1550-0072. Form Numbers: MHC-1 (OTS Form 1522) and MHC-2 (OTS Form 1523). Description: The OTS analyzes the submitted information to...

  11. The global stability of coexisting equilibria for three models of mutualism.

    PubMed

    Georgescu, Paul; Zhang, Hong; Maxin, Daniel

    2016-02-01

    We analyze the dynamics of three models of mutualism, establishing the global stability of coexisting equilibria by means of Lyapunov's second method. This further establishes the usefulness of certain Lyapunov functionals of an abstract nature introduced in an earlier paper. As a consequence, it is seen that the use of higher order self-limiting terms cures the shortcomings of Lotka-Volterra mutualisms, preventing unbounded growth and promoting global stability. PMID:26776263

  12. Certainty relations, mutual entanglement, and nondisplaceable manifolds

    NASA Astrophysics Data System (ADS)

    Pucha?a, Zbigniew; Rudnicki, ?ukasz; Chabuda, Krzysztof; Paraniak, Miko?aj; ?yczkowski, Karol

    2015-09-01

    We derive explicit bounds for the average entropy characterizing measurements of a pure quantum state of size N in L orthogonal bases. Lower bounds lead to novel entropic uncertainty relations, while upper bounds allow us to formulate universal certainty relations. For L =2 the maximal average entropy saturates at logN because there exists a mutually coherent state, but certainty relations are shown to be nontrivial for L ?3 measurements. In the case of a prime power dimension, N =pk , and the number of measurements L =N +1 , the upper bound for the average entropy becomes minimal for a collection of mutually unbiased bases. An analogous approach is used to study entanglement with respect to L different splittings of a composite system linked by bipartite quantum gates. We show that, for any two-qubit unitary gate U ?U(4 ) there exist states being mutually separable or mutually entangled with respect to both splittings (related by U ) of the composite system. The latter statement follows from the fact that the real projective space R P3?C P3 is nondisplaceable by a unitary transformation. For L =3 splittings the maximal sum of L entanglement entropies is conjectured to achieve its minimum for a collection of three mutually entangled bases, formed by two mutually entangling gates.

  13. Mutually unbiased bases with free parameters

    NASA Astrophysics Data System (ADS)

    Goyeneche, Dardo; Gómez, Santiago

    2015-12-01

    We present a systematic method to introduce free parameters in sets of mutually unbiased bases. In particular, we demonstrate that any set of m real mutually unbiased bases existing in dimension N >2 admits the introduction of (m -1 )N /2 free parameters that cannot be absorbed by a global unitary operation. As consequence, there are m =k +1 mutually unbiased bases in every dimension N =k2 with k3/2 free parameters, where k is even. We explicitly construct the maximal set of triplets of mutually unbiased bases for two-qubit systems and triplets, quadruplets, and quintuplets of mutually unbiased bases with free parameters for three-qubit systems. Furthermore, we study the richness of the entanglement structure of such bases and provide the quantum circuits required to implement all these bases with free parameters in the laboratory. We also show that the free parameters introduced can be controlled by a single party of the system. Finally, we find the upper bound for the maximal number of real and complex mutually unbiased bases existing in every dimension. This proof is simple, short, and considers basic matrix algebra.

  14. Prevalence of life-limiting conditions in children and young people in England: time trends by area type.

    PubMed

    Norman, Paul; Fraser, Lorna

    2014-03-01

    Palliative care services in England lack data on the number of children with 'life limiting conditions' (LLCs). Recent research determined that the prevalence of LLCs in children in England was double previous estimates. We build on this by analysing time-trends in the prevalence of LLCs by small area deprivation and geodemographic area types. Prevalence is highest for children aged less than one year but time trends show no increase for the youngest age group but significant increases for older children. These increases are mirrored by a decrease in all cause mortality for children suggesting improved survival. Rates are highest in more deprived areas and those typified by multicultural populations. Increasing prevalence and number of cases over time may require increased paediatric palliative care service provision in the future. PMID:24468834

  15. [Lower limb lymphography where there is no lymph circulatory disorder. Normal conditions and their limits (author's transl)].

    PubMed

    Bujar, H; Schioiu, L; Bratan, L

    1977-10-01

    Further lymphangiography for the lymphatic system dependent on the internal saphenous vein carried out on 70 patients to establish a lymphographical record of the pelvi-abdominal ganglia, simplified the counting of opacified vessels, and assessment of the development of the vascular system and the fragility of the walls and their calibre and pathway. The various aspects were assessed in relation to the anatomical situation (leg, thigh), age group and sex of the patients. Computerised analysis of the information lead to the conclusion that, even under normal conditions, there are statistical differences in the number of opacified vessels in the legs and in vascular fragility of the pre-inguinal region according to age group. The authors discuss the implications of the limits of the normal appearance of the lymphatic vessels. PMID:592239

  16. Doppler-broadened NICE-OHMS beyond the cavity-limited weak absorption condition - I. Theoretical description

    NASA Astrophysics Data System (ADS)

    Ma, Weiguang; Silander, Isak; Hausmaninger, Thomas; Axner, Ove

    2016-01-01

    Doppler-broadened (Db) noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) is conventionally described by an expression (here referred to as the CONV expression) that is restricted to the case when the single-pass absorbance, α0L, is much smaller than the empty cavity losses, π/F [here termed the conventional cavity-limited weak absorption (CCLWA) condition]. This limits the applicability of the technique, primarily its dynamic range and calibration capability. To remedy this, this work derives extended descriptions of Db NICE-OHMS that are not restricted to the CCLWA condition. First, the general principles of Db NICE-OHMS are scrutinized in some detail. Based solely upon a set of general assumptions, predominantly that it is appropriate to linearize the Beer-Lambert law, that the light is modulated to a triplet, and that the Pound-Drever-Hall sidebands are fully reflected, a general description of Db NICE-OHMS that is not limited to any specific restriction on α0L vs. π/F, here referred to as the FULL description, is derived. However, this description constitutes a set of equations to which no closed form solution has been found. Hence, it needs to be solved numerically (by iterations), which is inconvenient. To circumvent this, for the cases when α0L<π/F but without the requirement that the stronger CCLWA condition needs to be fulfilled, a couple of simplified extended expressions that are expressible in closed analytical form, referred to as the extended locking and extended transmission description, ELET, and the extended locking and full transmission description, ELFT, have been derived. An analysis based on simulations validates the various descriptions and assesses to which extent they agree. It is shown that in the CCLWA limit, all extended descriptions revert to the CONV expression. The latter one deviates though from the extended ones for α0L around and above 0.1π/F. The two simplified extended descriptions agree with the FULL description for a larger range of α0 L than the CONV expression, viz. for the ELET description for α0L up to 0.3π/F and for ELFT for α0L up to 0.6 or 1.0 π/F (depending on the mode of detection). It is then demonstrated that the conventional view of Db NICE-OHMS, which states that the out-of-phase and the in-phase signals can be referred to as a pure absorption and dispersion signal, respectively, breaks down when the CCLWA condition does not hold. In this case, the out-of-phase signal is additionally affected by the phase shifts of the laser components (i.e. dispersion) while the in-phase signal is also influenced by their attenuation. Access to new descriptions broadens considerably the dynamic range of Db NICE-OHMS and facilitates calibration using standard references samples, and thereby its applicability.

  17. Self-mixing interferometry with mutual independent orthogonal polarized light.

    PubMed

    Zhang, Shaohui; Zhang, Shulian; Tan, Yidong; Sun, Liqun

    2016-02-15

    A self-mixing interferometry with mutual independent orthogonal polarized light is introduced. Its most important feature is that two mutual independent orthogonal lights are used as measuring and reference light. Frequency shifting and polarization multiplexing technologies are used in the proposed optical system. Phase variation of the two orthogonal polarized beams is simultaneously measured through heterodyne demodulation with a lock-in amplifier. The phase difference of the orthogonal polarized light accurately reflects the target displacement. The target in this system is a non-cooperative object which is different from a traditional Michelson interferometer. The primary experimental results show that this kind of self-mixing interferometry is very feasible. Under typical room conditions, the system's short-term resolution is better than 2 nm. PMID:26872203

  18. Pyruvate and Lactate Metabolism by Shewanella oneidensis MR-1 under Fermentation, Oxygen Limitation, and Fumarate Respiration Conditions

    SciTech Connect

    Pinchuk, Grigoriy E.; Geydebrekht, Oleg V.; Hill, Eric A.; Reed, Jennifer L.; Konopka, Allan; Beliaev, Alex S.; Fredrickson, Jim K.

    2011-12-01

    Shewanella oneidensis MR-1 is a facultative anaerobe that derives energy by coupling organic matter oxidation to the reduction of wide range of electron acceptors. Here, we quantitatively assessed lactate and pyruvate metabolism of MR-1 under three distinct conditions: electron acceptor limited growth on lactate with O2; lactate with fumarate; and pyruvate fermentation. The latter does not support growth but provides energy for cell survival. Using physiological and genetic approaches combined with flux balance analysis, we showed that the proportion of ATP produced by substrate-level phosphorylation varied from 33% to 72.5% of that needed for growth depending on the electron acceptor nature and availability. While being indispensible for growth, respiration of fumarate does not contribute significantly to ATP generation and likely serves to remove formate, a product of pyruvate formate-lyase-catalyzed pyruvate disproportionation. Under both tested respiratory conditions S. oneidensis MR-1 carried out incomplete substrate oxidation, whereby the TCA cycle did not contribute significantly. Pyruvate dehydrogenase was not involved in lactate metabolism under O2 limitation but was required for anaerobic growth likely by supplying reducing equivalents for biosynthesis. The results suggest that pyruvate fermentation by S. oneidensis MR-1 cells represents a combination of substrate-level phosphorylation and respiration, where pyruvate serves as electron donor and electron acceptor. Pyruvate reduction to lactate at the expense of formate oxidation is catalyzed by recently described new type of oxidative NAD(P)H independent D-lactate dehydrogenase (Dld-II). The results further indicate that pyruvate reduction coupled to formate oxidation may be accompanied by proton motive force generation.

  19. Simulating biodegradation under mixing-limited conditions using Michaelis-Menten (Monod) kinetic expressions in a particle tracking model

    NASA Astrophysics Data System (ADS)

    Ding, Dong; Benson, David A.

    2015-02-01

    Recent studies have demonstrated that effective field-scale bioremediation reactions rates are significantly lower than batch- or lab-scale rates, when the same law of mass action is used to represent the reaction at both scales. The mismatch is usually attributed to poor mixing of reactants brought about by heterogeneity. A recent method, based on a purely Lagrangian particle tracking (PT) theoretical development, successfully reproduces the effects of mixing-limited bimolecular reaction (A + B ? C) from two benchmark experiments. In this numerical method, the reactants are represented by particles, and the small-scale physics are directly translated into a combination of two probabilities that govern whether: (1) reactant particles are collocated during a short time interval, and (2) two collocated particles favorably transform into a reaction. The latter is due to thermodynamics and is independent of scale of mixing. The former directly accounts for the degree of mixing in any system. We extend the application of the PT method to biodegradation, which is commonly characterized by more complex Michaelis-Menten (Monod) chemical kinetics. The advantage of the PT method is that it explains the variation of reaction rate based on mixing-controlled particle collisions instead of using empirical parameters. The PT method not only matches the Michaelis-Menten (Monod) equation under ideal conditions, but also captures the characteristics of non-ideal conditions such as imperfect mixing, disequilibrium, and limited availability of the active sites. We show these using hypothetical systems and also successfully apply the method to a column study of carbon tetrachloride biodegradation.

  20. Pyruvate and Lactate Metabolism by Shewanella oneidensis MR-1 under Fermentation, Oxygen Limitation, and Fumarate Respiration Conditions

    SciTech Connect

    Pinchuk, Grigoriy E.; Geydebrekht, Oleg V.; Hill, Eric A.; Reed, Jennifer L.; Konopka, Allan; Beliaev, Alex S.; Fredrickson, Jim K.

    2011-12-30

    Shewanella oneidensis MR-1 is a facultative anaerobe growing by coupling organic matter oxidation to reduction of wide range of electron acceptors. Here we quantitatively assessed lactate and pyruvate metabolism of these bacteria under three distinct conditions: electron acceptor limited growth on lactate with O2 and fumarate, and pyruvate fermentation, which does not sustain growth but allows cells to survive for prolonged period. Using physiological and genetic approaches combined with flux balance analysis, we showed that the proportion of ATP produced by substrate-level phosphorylation varied from 33% to 72.5% of all ATP needed for growth depending on the electron acceptor nature and availability. While being indispensible for growth, respiration of fumarate does not contribute much to ATP generation and likely serves to remove formate, a product of pyruvate formate-lyase-catalyzed pyruvate disproportionation. Under both tested respiratory conditions S. oneidensis MR-1 carried out incomplete substrate oxidation, and TCA cycle did not contribute significantly to substrate oxidation. Pyruvate dehydrogenase reaction was not involved in lactate metabolism under O2 limitation, however was important for anaerobic growth probably supplying reducing equivalents for biosynthesis. Unexpectedly, obtained results suggest that pyruvate fermentation by S. oneidensis MR-1 cells represents a combination between substrate-level phosphorylation and a respiratory process, where pyruvate serves as electron donor and electron acceptor. Pyruvate reduction to lactate at the expense of formate oxidation is catalyzed by recently described new type of oxidative NAD(P)H independent D-lactate dehydrogenase (Dld-II). Based on involved enzymes localization we hypothesize that pyruvate reduction coupled to formate oxidation may be accompanied by proton motive force generation.

  1. Use of the Priestley-Taylor evaporation equation for soil water limited conditions in a small forest clearcut

    USGS Publications Warehouse

    Flint, A.L.; Childs, S.W.

    1991-01-01

    The Priestley-Taylor equation, a simplification of the Penman equation, was used to allow calculations of evapotranspiration under conditions where soil water supply limits evapotranspiration. The Priestley-Taylor coefficient, ??, was calculated to incorporate an exponential decrease in evapotranspiration as soil water content decreases. The method is appropriate for use when detailed meteorological measurements are not available. The data required to determine the parameter for the ?? coefficient are net radiation, soil heat flux, average air temperature, and soil water content. These values can be obtained from measurements or models. The dataset used in this report pertains to a partially vegetated clearcut forest site in southwest Oregon with soil depths ranging from 0.48 to 0.70 m and weathered bedrock below that. Evapotranspiration was estimated using the Bowen ratio method, and the calculated Priestley-Taylor coefficient was fitted to these estimates by nonlinear regression. The calculated Priestley-Taylor coefficient (?????) was found to be approximately 0.9 when the soil was near field capacity (0.225 cm3 cm-3). It was not until soil water content was less than 0.14 cm3 cm-3 that soil water supply limited evapotranspiration. The soil reached a final residual water content near 0.05 cm3 cm-3 at the end of the growing season. ?? 1991.

  2. Performance limitation and the role of core temperature when wearing light-weight workwear under moderate thermal conditions.

    PubMed

    Kofler, Philipp; Burtscher, Martin; Heinrich, Dieter; Bottoni, Giuliamarta; Caven, Barnaby; Bechtold, Thomas; Teresa Herten, Anne; Hasler, Michael; Faulhaber, Martin; Nachbauer, Werner

    2015-01-01

    The objective of this investigation was to achieve an understanding about the relationship between heat stress and performance limitation when wearing a two-layerfire-resistant light-weight workwear (full-clothed ensemble) compared to an one-layer short sports gear (semi-clothed ensemble) in an exhaustive, stressful situation under moderate thermal condition (25°C). Ten well trained male subjects performed a strenuous walking protocol with both clothing ensembles until exhaustion occurred in a climatic chamber. Wearing workwear reduced the endurance performance by 10% (p=0.007) and the evaporation by 21% (p=0.003), caused a more pronounced rise in core temperature during submaximal walking (0.7±0.3 vs. 1.2±0.4°C; p?0.001) and from start till exhaustion (1.4±0.3 vs. 1.8±0.5°C; p=0.008), accelerated sweat loss (13±2 vs. 15±3gmin(-1); p=0.007), and led to a significant higher heart rate at the end of cool down (103±6 vs. 111±7bpm; p=0.004). Correlation analysis revealed that core temperature development during submaximal walking and evaporation may play important roles for endurance performance. However, a critical core temperature of 40°C, which is stated to be a crucial factor for central fatigue and performance limitation, was not reached either with the semi-clothed or the full-clothed ensemble (38.3±0.4 vs. 38.4±0.5°C). Additionally, perceived exertion did not increase to a higher extent parallel with the rising core temperature with workwear which would substantiate the critical core temperature theory. In conclusion, increased heat stress led to cardiovascular exercise limitation rather than central fatigue. PMID:25526658

  3. Species-Specific Seed Dispersal in an Obligate Ant-Plant Mutualism

    PubMed Central

    Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

    2009-01-01

    Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism. PMID:19194502

  4. Clinical update--the teeth and the maxillary sinus: the mutual impact of clinical procedures, disease conditions and their treatment implications. Part 2. Odontogenic sinus disease and elective clinical procedures involving the maxillary antrum: diagnosis and management.

    PubMed

    Sandler, H J

    1999-04-01

    Although odontogenic sinusitis is a rare entity when compared to sinus disease of rhinogenic origin, it is extremely important to identify a dental aetiology when it occurs. The offending tooth or teeth would thus require endodontic treatment or extraction, and the sinus disease carefully assessed and appropriately managed. Aetiology and presentation of oro-antral fistulae are also discussed and guidelines for the management of this complication are recommended. Certain lesions such as cysts and tumours may involve the jaws and hence the maxillary antrum; some of these, such as a radicular cyst are quite common, but the rarer ones are included for completeness. Surgical techniques are continuously evolving to optimise form and function of the jaws, and when applied to the maxilla there may be some impact on nasal and sinus function. The advent, and now proven success, of osseointegrated jaw implants have brought with them innovations and refinements of bone grafting techniques, and more recently distraction osteogenesis for augmentation. Maxillary osteotomies for surgical orthodontics, and to facilitate prosthodontic treatment are briefly mentioned, as most of these inevitably involve the antrum and/or nose. This paper discusses, in summary form, important aspects of clinical dental practice which may involve the maxillary antrum. It is thus a broad overview of certain pathologic conditions and elective surgical procedures which have relevance to both medical and dental practitioners. PMID:11411074

  5. Analysis of Vertical Turbulent Heat Flux Limit in Stable Conditions with a Local Equilibrium, Turbulence Closure Model

    NASA Astrophysics Data System (ADS)

    ?obocki, Lech

    2013-09-01

    Assuming that the vertical turbulent heat flux vanishes at extremely stable conditions, one should expect its maximal absolute value to occur somewhere at moderate stability, between a neutral and extremely stable equilibrium. Consequently, in some situations duality of solutions may be encountered (e.g. two different values of temperature difference associated with the same values of heat flux and wind speed). A quantitative analysis of this feature with a local equilibrium Reynolds-stress model is presented. The fixed-wind / fixed-shear maximum has been identified both in the bulk and in single-point flux-gradient relationships (that is, in the vertical temperature gradient and wind-shear parameter domain). The value of the Richardson number corresponding to this maximum is derived from the model equations. To study the possible feedback in strongly stable conditions, weak and intense cooling scenarios have been simulated with a one-dimensional numerical, high-resolution atmospheric boundary-layer model. Despite the rapid cooling, flow decoupling at the surface has not been observed; instead, a stability-limited heat flux is maintained, with a gradual increase of the Richardson number towards the top of the turbulent layer, with some signs of oscillatory behaviour at intermediate heights. Vertical changes of wind shear and the Brunt-Väisälä frequency display a remarkably non-monotonic character, with some signs of a gradually developing instability.

  6. The Activity of Nodules of the Supernodulating Mutant Mtsunn Is not Limited by Photosynthesis under Optimal Growth Conditions

    PubMed Central

    Cabeza, Ricardo A.; Lingner, Annika; Liese, Rebecca; Sulieman, Saad; Senbayram, Mehmet; Tränkner, Merle; Dittert, Klaus; Schulze, Joachim

    2014-01-01

    Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO2 assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO2 assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N2 fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants. PMID:24727372

  7. On the spatial distribution of the transpiration and soil moisture of a Mediterranean heterogeneous ecosystem in water-limited conditions.

    NASA Astrophysics Data System (ADS)

    Curreli, Matteo; Corona, Roberto; Montaldo, Nicola; Albertson, John D.; Oren, Ram

    2014-05-01

    Mediterranean ecosystems are characterized by a strong heterogeneity, and often by water-limited conditions. In these conditions contrasting plant functional types (PFT, e.g. grass and woody vegetation) compete for the water use. Both the vegetation cover spatial distribution and the soil properties impact the soil moisture (SM) spatial distribution. Indeed, vegetation cover density and type affects evapotranspiration (ET), which is the main lack of the soil water balance in these ecosystems. With the objective to carefully estimate SM and ET spatial distribution in a Mediterranean water-limited ecosystem and understanding SM and ET relationships, an extended field campaign is carried out. The study was performed in a heterogeneous ecosystem in Orroli, Sardinia (Italy). The experimental site is a typical Mediterranean ecosystem where the vegetation is distributed in patches of woody vegetation (wild olives mainly) and grass. Soil depth is low and spatially varies between 10 cm and 40 cm, without any correlation with the vegetation spatial distribution. ET, land-surface fluxes and CO2 fluxes are estimated by an eddy covariance technique based micrometeorological tower. But in heterogeneous ecosystems a key assumption of the eddy covariance theory, the homogeneity of the surface, is not preserved and the ET estimate may be not correct. Hence, we estimate ET of the woody vegetation using the thermal dissipation method (i.e. sap flow technique) for comparing the two methodologies. Due the high heterogeneity of the vegetation and soil properties of the field a total of 54 sap flux sensors were installed. 14 clumps of wild olives within the eddy covariance footprint were identified as the most representative source of flux and they were instrumented with the thermal dissipation probes. Measurements of diameter at the height of sensor installation (height of 0.4 m above ground) were recorded in all the clumps. Bark thickness and sapwood depth were measured on several trees to obtain a generalized estimates of sapwood depth. The known of allometric relationships between sapwood area, diameter and canopy cover area within the eddy covariance footprint helped for the application of a reliable scaling procedure of the local sap flow estimates which are in a good agreement with the estimates of ET eddy covariance based. Soil moisture were also extensively monitored through 25 probes installed in the eddy covariance footprint. Results show that comparing eddy covariance and sap flow ET estimates eddy covariance technique is still accurate in this heterogeneous field, whereas the key assumption, surface homogeneity, is not preserved. Furthermore, interestingly wild olives still transpire at higher rates for the driest soil moisture conditions, confirming the hydraulic redistribution from soil below the roots, and from roots penetrating deep cracks in the underlying basalt parent rock.

  8. Mutualism with sea anemones triggered the adaptive radiation of clownfishes

    PubMed Central

    2012-01-01

    Background Adaptive radiation is the process by which a single ancestral species diversifies into many descendants adapted to exploit a wide range of habitats. The appearance of ecological opportunities, or the colonisation or adaptation to novel ecological resources, has been documented to promote adaptive radiation in many classic examples. Mutualistic interactions allow species to access resources untapped by competitors, but evidence shows that the effect of mutualism on species diversification can greatly vary among mutualistic systems. Here, we test whether the development of obligate mutualism with sea anemones allowed the clownfishes to radiate adaptively across the Indian and western Pacific oceans reef habitats. Results We show that clownfishes morphological characters are linked with ecological niches associated with the sea anemones. This pattern is consistent with the ecological speciation hypothesis. Furthermore, the clownfishes show an increase in the rate of species diversification as well as rate of morphological evolution compared to their closest relatives without anemone mutualistic associations. Conclusions The effect of mutualism on species diversification has only been studied in a limited number of groups. We present a case of adaptive radiation where mutualistic interaction is the likely key innovation, providing new insights into the mechanisms involved in the buildup of biodiversity. Due to a lack of barriers to dispersal, ecological speciation is rare in marine environments. Particular life-history characteristics of clownfishes likely reinforced reproductive isolation between populations, allowing rapid species diversification. PMID:23122007

  9. A consumer-resource approach to the density-dependent population dynamics of mutualism

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2010-01-01

    Like predation and competition, mutualism is now recognized as a consumer resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant- mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

  10. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... shall be granted unless the proposed issuance of the mutual capital certificates and the form and manner...) Application form; supporting information. An application for approval of the issuance of mutual...

  11. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... shall be granted unless the proposed issuance of the mutual capital certificates and the form and manner...) Application form; supporting information. An application for approval of the issuance of mutual...

  12. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... shall be granted unless the proposed issuance of the mutual capital certificates and the form and manner...) Application form; supporting information. An application for approval of the issuance of mutual...

  13. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... shall be granted unless the proposed issuance of the mutual capital certificates and the form and manner...) Application form; supporting information. An application for approval of the issuance of mutual...

  14. 12 CFR 544.5 - Federal mutual savings association bylaws.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Federal mutual savings association bylaws. 544.5 Section 544.5 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Bylaws § 544.5 Federal mutual savings association bylaws. (a) General. A Federal mutual...

  15. 12 CFR 144.1 - Federal mutual charter.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Federal mutual charter. 144.1 Section 144.1 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 144.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  16. 12 CFR 544.1 - Federal mutual charter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Federal mutual charter. 544.1 Section 544.1 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 544.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  17. 12 CFR 144.1 - Federal mutual charter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Federal mutual charter. 144.1 Section 144.1 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 144.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  18. 12 CFR 544.1 - Federal mutual charter.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Federal mutual charter. 544.1 Section 544.1 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 544.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  19. Planning ahead with children with life-limiting conditions and their families: development, implementation and evaluation of ‘My Choices’

    PubMed Central

    2013-01-01

    Background The United Kingdom has led the world in the development of children’s palliative care. Over the past two decades, the illness trajectories of children with life-limiting conditions have extended with new treatments and better home-based care. Future planning is a critically under-researched aspect of children’s palliative care globally. This paper describes the development, implementation and evaluation of innovative child and parent-held palliative care planning resources. The resources were designed to facilitate parent and child thinking and engagement in future planning, and to determine care preferences and preferred locations of care for children with life-limiting conditions from diagnosis onwards. These resources fill a significant gap in palliative care planning before the end-of-life phase. Methods Drawing on contemporaneous research on producing evidence-based children’s health information, we collaborated with leading children’s not-for-profit organisations, parents, children, and professionals. A set of resources (My Choices booklets) were developed for parents and children and evaluated using interviews (parents, children, professionals) and questionnaires (professionals) and an open web-based consultation. Results Parents and children responded in three ways: Some used the booklets to produce detailed written plans with clear outcomes and ideas about how best to achieve desired outcomes. Others preferred to use the booklet to help them think about potential options. Remaining parents found it difficult to think about the future and felt there was no point because they perceived there to be no suitable local services. Professionals varied in confidence in their ability to engage with families to plan ahead and identified many challenges that prevented them from doing so. Few families shared their plans with professionals. Parents and children have far stronger preferences for home-care than professionals. Conclusion The My Choices booklets were revised in light of findings, have been endorsed by Together for Short Lives, and are free to download in English and Welsh for use by parents and young people globally. More work needs to be done to support families who are not yet receptive to planning ahead. Professionals would benefit from more training in person-centred approaches to future planning and additional communications skills to increase confidence and ability to engage with families to deliver sensitive palliative care planning. PMID:23384400

  20. Mutual information-based analysis of JPEG2000 contexts.

    PubMed

    Liu, Zhen; Karam, Lina J

    2005-04-01

    Context-based arithmetic coding has been widely adopted in image and video compression and is a key component of the new JPEG2000 image compression standard. In this paper, the contexts used in JPEG2000 are analyzed using the mutual information, which is closely related to the compression performance. We first show that, when combining the contexts, the mutual information between the contexts and the encoded data will decrease unless the conditional probability distributions of the combined contexts are the same. Given I, the initial number of contexts, and F, the final desired number of contexts, there are S(I, F) possible context classification schemes where S(I, F) is called the Stirling number of the second kind. The optimal classification scheme is the one that gives the maximum mutual information. Instead of using an exhaustive search, the optimal classification scheme can be obtained through a modified generalized Lloyd algorithm with the relative entropy as the distortion metric. For binary arithmetic coding, the search complexity can be reduced by using dynamic programming. Our experimental results show that the JPEG2000 contexts capture the correlations among the wavelet coefficients very well. At the same time, the number of contexts used as part of the standard can be reduced without loss in the coding performance. PMID:15825477

  1. An orb-weaver spider exploits an ant–acacia mutualism for enemy-free space

    PubMed Central

    Styrsky, John D

    2014-01-01

    Exploiters of protection mutualisms are assumed to represent an important threat for the stability of those mutualisms, but empirical evidence for the commonness or relevance of exploiters is limited. Here, I describe results from a manipulative study showing that an orb-weaver spider, Eustala oblonga, inhabits an ant-acacia for protection from predators. This spider is unique in the orb-weaver family in that it associates closely with both a specific host plant and ants. I tested the protective effect of acacia ants on E. oblonga by comparing spider abundance over time on acacias with ants and on acacias from which entire ant colonies were experimentally removed. Both juvenile and adult spider abundance significantly decreased over time on acacias without ants. Concomitantly, the combined abundance of potential spider predators increased over time on acacias without ants. These results suggest that ant protection of the ant-acacia Acacia melanocerus also protects the spiders, thus supporting the hypothesis that E. oblonga exploits the ant–acacia mutualism for enemy-free space. Although E. oblonga takes advantage of the protection services of ants, it likely exacts little to no cost and should not threaten the stability of the ant–acacia mutualism. Indeed, the potential threat of exploiter species to protection mutualisms in general may be limited to species that exploit the material rewards traded in such mutualisms rather than the protection services. PMID:24558583

  2. An orb-weaver spider exploits an ant-acacia mutualism for enemy-free space.

    PubMed

    Styrsky, John D

    2014-02-01

    Exploiters of protection mutualisms are assumed to represent an important threat for the stability of those mutualisms, but empirical evidence for the commonness or relevance of exploiters is limited. Here, I describe results from a manipulative study showing that an orb-weaver spider, Eustala oblonga, inhabits an ant-acacia for protection from predators. This spider is unique in the orb-weaver family in that it associates closely with both a specific host plant and ants. I tested the protective effect of acacia ants on E.?oblonga by comparing spider abundance over time on acacias with ants and on acacias from which entire ant colonies were experimentally removed. Both juvenile and adult spider abundance significantly decreased over time on acacias without ants. Concomitantly, the combined abundance of potential spider predators increased over time on acacias without ants. These results suggest that ant protection of the ant-acacia Acacia melanocerus also protects the spiders, thus supporting the hypothesis that E.?oblonga exploits the ant-acacia mutualism for enemy-free space. Although E.?oblonga takes advantage of the protection services of ants, it likely exacts little to no cost and should not threaten the stability of the ant-acacia mutualism. Indeed, the potential threat of exploiter species to protection mutualisms in general may be limited to species that exploit the material rewards traded in such mutualisms rather than the protection services. PMID:24558583

  3. Mutual information between SSH and SST fields

    NASA Astrophysics Data System (ADS)

    Le goff, Clément; Chapron, Bertrand; Fablet, Ronan; Tandeo, Pierre; Autret, Emmanuelle; Ailliot, Pierre

    2015-04-01

    Mutual information between SST and SSH Investigations to relate satellite SST and SSH measurements in the Agulhas return current region are presented. In this study, we focus on the use of SSH and SST maps obtained during the year 2004, corresponding to a particularly well-sampled period for altimetry. The SST and SSH anomalies are then obtained as high-pass filtered fields, to analyze scales smaller than approximately 300km. As revealed, we clearly distinguish different regimes. During the winter months, a marked strong correlation between fields of SSH and SST anomalies is clearly revealed. During the summer months, a much lower correlation is found. Further conditioning the analysis to separate the areas of positive and negative SSH anomalies, it is then obtained, for both summer and winter periods, that aeras of negative SSH anomalies always correspond with areas of negative SST anomalies. This high correspondance also applies in winter but only for areas of positive SSH anomalies, which indeed well match with areas of positive SST anomalies. In summer, this high correspondance is lost, and areas with positive SSH anomalies do not necessarily correspond to positive SST anomalies. Accordingly, such an effect affects and weakens the overall SST/SSH correlation during the summer months. Yet, the areas of positive SSH anomalies are not fully disconnected from the areas of positive SST anomalies. For these cases, observations and results demonstrate a systematic spatial shift between them. This suggests the influence of the mixed layer depth and wind speed to control the spatial correspondance between SST and SSH anomalies, especially below regions of positive SSH anomalies. In such cases, the upper layer SST anomalies are certainly advected by the interior flow to also provide means to relate surface observations and interior dynamics.

  4. Expected years of life free of chronic condition-induced activity limitations - United States, 1999-2008.

    PubMed

    Molla, Michael T

    2013-11-22

    Over the 20th century, the U.S. population has witnessed major changes in fatal and nonfatal health outcomes. Mortality has declined, and life expectancy has increased continuously; chronic conditions have replaced acute diseases as leading causes of both illness and death. During 1900-2008, average life expectancy at birth for the total U.S. population increased from 47.3 years in 1900 to 78.1 years in 2008, a gain of 30.8 years. In addition, an increasing proportion of the U.S. population is aged >65 years. According to the U.S. Census Bureau estimates, at the beginning of the 20th century, the U.S. population aged >65 years constituted only 4.1 percent of the total population; by 2008, the percentage of the total U.S. population aged >65 years was 12.8%. However, declines in mortality are not necessarily associated with declines in morbidity or the consequences of chronic conditions on life activities. The possibility that longer life might be accompanied by poor health makes it essential to develop measures that account for both mortality and morbidity at the same time. Hence, over the past 40 years, a new set of health measures (e.g., "healthy life expectancies") have been developed that account for both mortality and life spent free of the consequences of ill health. One of these newly developed set of measures (called "active life expectancy") is the average number of years expected to be lived without activity limitations. PMID:24264496

  5. The course of physical functional limitations and occupational conditions in a middle-aged working population in France

    PubMed Central

    2012-01-01

    Background Physical functional limitations (PFL) have mainly been studied in older populations. The aim of this study was to better understand the course of PFL and associations with occupational factors by gender in a middle-aged working population. Methods The data came from 16,950 workers in the ESTEV (Enquête Santé Travail et Vieillissement) cohort in France. PFL were assessed using the physical abilities section of the Nottingham Health Profile. Occupational conditions were measured with a self-administered questionnaire covering physical and psychosocial factors in 1990 and 1995. Multivariate analyses were used to assess the associations. Results The PFL appearance rate in 1995 was the same by gender (6.3%); the rate of PFL recovery was higher in men (23.9% versus 20.9%). Age was an independent factor of PFL at age 47?years or older in both genders after adjusting for confounding factors. The PFL appearance rate in 1995 was higher with physical occupational exposure in 1990, such as awkward work with a dose relation in both genders, while the PFL recovery rate decreased significantly only for men. Exposure to psychosocial occupational conditions, such as having the means to produce quality work in 1990, was significantly associated with a decreased PFL appearance rate in 1995 in both genders, and having high decision latitude in 1990 was associated with a decreased PFL appearance rate in 1995 only in men. Changes in exposure to occupational factors between 1990 and 1995 were associated with the PFL appearance and recovery rates in 1995 in both genders. Conclusions After five years, the course of PFL in this working population changed and was associated with physical and psychosocial occupational factors. Relationships were stronger for the PFL appearance rate in both genders and were weaker for recovery from PFL, mainly among women. PMID:22494385

  6. Integrating plant carbon dynamics with mutualism ecology.

    PubMed

    Pringle, Elizabeth G

    2016-04-01

    71 I. 71 II. 72 III. 73 IV. 74 V. 74 74 References 74 SUMMARY: Plants reward microbial and animal mutualists with carbohydrates to obtain nutrients, defense, pollination, and dispersal. Under a fixed carbon budget, plants must allocate carbon to their mutualists at the expense of allocation to growth, reproduction, or storage. Such carbon trade-offs are indirectly expressed when a plant exhibits reduced growth or fecundity in the presence of its mutualist. Because carbon regulates the costs of all plant mutualisms, carbon dynamics are a common platform for integrating these costs in the face of ecological complexity and context dependence. The ecophysiology of whole-plant carbon allocation could thus elucidate the ecology and evolution of plant mutualisms. If mutualisms are costly to plants, then they must be important but frequently underestimated sinks in the terrestrial carbon cycle. PMID:26414800

  7. Mutual information and spontaneous symmetry breaking

    NASA Astrophysics Data System (ADS)

    Hamma, A.; Giampaolo, S. M.; Illuminati, F.

    2016-01-01

    We show that the metastable, symmetry-breaking ground states of quantum many-body Hamiltonians have vanishing quantum mutual information between macroscopically separated regions and are thus the most classical ones among all possible quantum ground states. This statement is obvious only when the symmetry-breaking ground states are simple product states, e.g., at the factorization point. On the other hand, symmetry-breaking states are in general entangled along the entire ordered phase, and to show that they actually feature the least macroscopic correlations compared to their symmetric superpositions is highly nontrivial. We prove this result in general, by considering the quantum mutual information based on the two-Rényi entanglement entropy and using a locality result stemming from quasiadiabatic continuation. Moreover, in the paradigmatic case of the exactly solvable one-dimensional quantum X Y model, we further verify the general result by considering also the quantum mutual information based on the von Neumann entanglement entropy.

  8. Conditional knockdown of BCL2A1 reveals rate-limiting roles in BCR-dependent B-cell survival.

    PubMed

    Sochalska, M; Ottina, E; Tuzlak, S; Herzog, S; Herold, M; Villunger, A

    2016-04-01

    Bcl2 family proteins control mitochondrial apoptosis and its members exert critical cell type and differentiation stage-specific functions, acting as barriers against autoimmunity or transformation. Anti-apoptotic Bcl2a1/Bfl1/A1 is frequently deregulated in different types of blood cancers in humans but its physiological role is poorly understood as quadruplication of the Bcl2a1 gene locus in mice hampers conventional gene targeting strategies. Transgenic overexpression of A1, deletion of the A1-a paralogue or constitutive knockdown in the hematopoietic compartment of mice by RNAi suggested rate-limiting roles in lymphocyte development, granulopoiesis and mast cell activation. Here we report on the consequences of conditional knockdown of A1 protein expression using a reverse transactivator (rtTA)-driven approach that highlights a critical role for this Bcl2 family member in the maintenance of mature B-cell homeostasis. Furthermore, we define the A1/Bim (Bcl-2 interacting mediator of cell death) axis as a target of key kinases mediating B-cell receptor (BCR)-dependent survival signals, such as, spleen tyrosine kinase (Syk) and Brutons tyrosine kinase (Btk). As such, A1 represents a putative target for the treatment of B-cell-related pathologies depending on hyperactivation of BCR-emanating survival signals and loss of A1 expression accounts, in part, for the pro-apoptotic effects of Syk- or Btk inhibitors that rely on the 'BH3-only' protein Bim for cell killing. PMID:26450454

  9. Study of workability limits of porous materials under different upsetting conditions by compressible rigid plastic finite element method

    NASA Astrophysics Data System (ADS)

    Zhang, X. Q.; Peng, Y. H.; Ruan, X. Y.; Li, M. Q.; Wu, S. C.

    2000-04-01

    Workability limits must be considered when designing powder metallurgy (PM) forging processes. This research successfully applied the general upsetting experiment method to the deformation of porous materials. Based on the plastic theory of porous materials, the compressible rigid plastic finite element method is used to simulate the deformation processes of cold upsetting of disks and rings for porous metal materials with a full account of contact friction boundary conditions, the height-to-diameter ratio, the initial relative density, and the die and workpiece geometry. Furthermore, a successful analysis of the cold forging process results in the prediction of the stress, the strain, and the density field. By coupling with the ductile fracture criterion, which is a strain-based criterion obtained by Lee and Kuhn, possible defects leading to material failure have been checked. This research reveals that larger height to diameter and a lesser friction factor can delay the local strain locus to intersect with the Lee and Kuhn’s fracture line and restrain formation of the surface crack. Meanwhile, it reveals that the initial relative density has only a very small influence on the strain to fracture in compression, and it shows the forming behavior of the ring and disk with the curved die. According to Lee and Kuhn’s results, the calculated results agree well with the experimental results.

  10. Hierarchical classifier design using mutual information.

    PubMed

    Sethi, I K; Sarvarayudu, G P

    1982-04-01

    A nonparametric algorithm is presented for the hierarchical partitioning of the feature space. The algorithm is based on the concept of average mutual information, and is suitable for multifeature multicategory pattern recognition problems. The algorithm generates an efficient partitioning tree for specified probability of error by maximizing the amount of average mutual information gain at each partitioning step. A confidence bound expression is presented for the resulting classifier. Three examples, including one of handprinted numeral recognition, are presented to demonstrate the effectiveness of the algorithm. PMID:21869061

  11. Impact of Mutual Mentoring on Research

    NASA Astrophysics Data System (ADS)

    Whitten, Barbara; Blaha, Cynthia; Bug, Amy; Cox, Anne; Fritz, Linda

    2011-03-01

    In this talk we discuss one of the impacts of an NSF ADVANCE sponsored horizontal, mutual mentoring alliance. Our cohort of five women physicists at liberal arts colleges has found that mutual mentoring has had a profound impact on many aspects of our professional lives. In this talk we will give some specific ways that we have supported and helped to expand each other's research. For some new areas of research were opened, for others new focus was brought to existing areas, and still others found acceptance for where they were.

  12. Strain localization in brittle-ductile shear zones: fluid abundant vs fluid limited conditions (an example from Wyangala area, Australia)

    NASA Astrophysics Data System (ADS)

    Spruzeniece, L.; Piazolo, S.

    2015-04-01

    This study focuses on physiochemical processes occurring in a brittle-ductile shear zone at both fluid-present and fluid-limited conditions. In the studied shear zone (Wyangala, SE Australia), a coarse-grained two feldspar-quartz-biotite granite is transformed into a medium grained orthogneiss at the shear zone margins and a fine-grained quartz-muscovite phyllonite in the central parts. The orthogneiss displays cataclasis of feldspar and crystal-plastic deformation of quartz. Quartz accommodates most of the deformation and is extensively recrystallized showing distinct crystallographic preferred orientation (CPO). Feldspar-to-muscovite, biotite-to-muscovite and albitization reactions occur locally at porphyroclasts' fracture surfaces and margins. However, the bulk rock composition shows very little change in respect to the wall rock composition. In contrast, in the shear zone centre quartz occurs as large, weakly deformed porphyroclasts, in sizes similar to that in the wall rock, suggesting that it has undergone little deformation. Feldspars and biotite are almost completely reacted to muscovite, which is arranged in a fine-grained interconnected matrix. Muscovite-rich layers contain significant amounts of fine-grained intermixed quartz with random CPO. These domains are interpreted to have accommodated most of the strain. Bulk rock chemistry data shows a significant increase in SiO2 and depletion in NaO content compared to the wall rock composition. We suggest that the high and low strain fabrics represent markedly different scenarios and cannot be interpreted as a simple sequential development with respect to strain. We suggest that the fabrics and mineralogical changes in the shear zone centre have formed due to fluid influx probably along an initially brittle fracture. Here, hydration reactions dramatically changed the rheological properties of the rock. In the newly produced muscovite-quartz layers creep cavitation associated with grain boundary sliding and fluid pumping resulted in strain localization, further fluid influx and subsequent substantial changes in bulk chemistry. Strain partitioning between the "soft" muscovite-quartz layers and "hard" original igneous quartz grains allows preservation of the igneous quartz grains. In contrast, in the shear zone margins the amount of fluid and reactions was limited; here deformation was mainly accommodated by recrystallization of the igneous quartz grains. The studied shear zone exemplifies the role of syn-deformational fluids and fluid-induced reactions on the dominance of deformation processes and subsequent contrasting rheological behaviour at micron- to meter scale.

  13. Methods for automatized detection of rapid changes in lateral boundary condition fields for NWP limited area models

    NASA Astrophysics Data System (ADS)

    Tudor, M.

    2015-08-01

    Three-hourly temporal resolution of lateral boundary data for limited area models (LAMs) can be too infrequent to resolve rapidly moving storms. This problem is expected to be worse with increasing horizontal resolution. In order to detect intensive disturbances in surface pressure moving rapidly through the model domain, a filtered surface pressure field (MCUF) is computed operationally in the ARPEGE global model of Météo France. The field is distributed in the coupling files along with conventional meteorological fields used for lateral boundary conditions (LBCs) for the operational forecast using limited area model ALADIN (Aire Limitée Adaptation dynamique Développement InterNational) in the Meteorological and Hydrological Service of Croatia (DHMZ). Here an analysis is performed of the MCUF field for the LACE coupling domain for the period from 23 January 2006, when it became available, until 15 November 2014. The MCUF field is a good indicator of rapidly moving pressure disturbances (RMPDs). Its spatial and temporal distribution can be associated with the usual cyclone tracks and areas known to be supporting cyclogenesis. An alternative set of coupling files from the IFS operational run in the European Centre for Medium-Range Weather Forecasts (ECMWF) is also available operationally in DHMZ with 3-hourly temporal resolution, but the MCUF field is not available. Here, several methods are tested that detect RMPDs in surface pressure a posteriori from the IFS model fields provided in the coupling files. MCUF is computed by running ALADIN on the coupling files from IFS. The error function is computed using one-time-step integration of ALADIN on the coupling files without initialization, initialized with digital filter initialization (DFI) or scale-selective DFI (SSDFI). Finally, the amplitude of changes in the mean sea level pressure is computed from the fields in the coupling files. The results are compared to the MCUF field of ARPEGE and the results of same methods applied to the coupling files from ARPEGE. Most methods give a signal for the RMPDs, but DFI reduces the storms too much to be detected. The error functions without filtering and amplitude have more noise, but the signal of a RMPD is also stronger. The methods are tested for NWP LAM ALADIN, but could be applied to other LAMs and benefit the performance of climate LAMs.

  14. Limited area NWP and regional climate modeling: A test of the relaxation vs Eta lateral boundary condition schemes

    NASA Astrophysics Data System (ADS)

    Mesinger, F.; Veljovic, K.

    2012-04-01

    With very few exceptions, just about all limited area models (LAMs) used in operational NWP and regional climate modeling use the Davies relaxation lateral boundary conditions (LBCs), even though from the mathematical point of view they are not the best choice one can make. While in the early stages of the primitive equation LAM development in the seventies numerous schemes have been proposed and tested, LAM communities have eventually for the most part settled on the relaxation LBCs with few questions asked. An exception is the Eta model used extensively at NCEP and numerous other centers, in which the Mesinger (1977) LBCs are used. They prescribe variables along the outermost row of grid points only; all of them at the inflow points and one less at the outflow points where the tangential velocity components are extrapolated from inside of the model domain. Additional schemes are in place to suppress separation of gravity-wave solutions on C-subgrids of the model's E grid. A recent paper of Veljovic et al. (2010) included three 32-day forecasts done with both the Eta and the relaxation LBCs and the comparison of some of their verification results. This experiment was subsequently extended by three additional forecasts to arrive at an ensemble of six members run with both schemes, along with a more complete analysis of results. Results of two verification schemes used as well as the inspection of forecast wind fields strongly suggest an advantage of the Eta over the conventional and costlier relaxation scheme, thereby raising doubts as to the justification for its use.

  15. Paul Drude's Prediction of Nonreciprocal Mutual Inductance for Tesla Transformers

    PubMed Central

    McGuyer, Bart

    2014-01-01

    Inductors, transmission lines, and Tesla transformers have been modeled with lumped-element equivalent circuits for over a century. In a well-known paper from 1904, Paul Drude predicts that the mutual inductance for an unloaded Tesla transformer should be nonreciprocal. This historical curiosity is mostly forgotten today, perhaps because it appears incorrect. However, Drude's prediction is shown to be correct for the conditions treated, demonstrating the importance of constraints in deriving equivalent circuits for distributed systems. The predicted nonreciprocity is not fundamental, but instead is an artifact of the misrepresentation of energy by an equivalent circuit. The application to modern equivalent circuits is discussed. PMID:25542040

  16. The preset grating effect for mutually pumped phase conjugator

    NASA Astrophysics Data System (ADS)

    Ma, Lin; Kang, Zhihua; Zhang, Ninghua; Liu, Jifang; Shi, Shunxiang

    2014-11-01

    Based on the four-wave mixing mechanism and light fanning effect, a mutually pumped phase conjugator(MPPC) model is proposed to analyze the variation of MPPC output response with time for different scattering seed value. It shows that preset grating can enhance the fan light intensity when it satisfies Bragg condition and also can shorten MPPC response time. In experiment the bird-wings MPPC is done with or without the preset grating and the variation of MPPC reflectivity with time is obtained in two cases, and simulation conclusion is in agreement with the experimental result. These results have importance for applications of MPPC on optical heterodyne detection.

  17. Paul Drude's prediction of nonreciprocal mutual inductance for Tesla transformers.

    PubMed

    McGuyer, Bart

    2014-01-01

    Inductors, transmission lines, and Tesla transformers have been modeled with lumped-element equivalent circuits for over a century. In a well-known paper from 1904, Paul Drude predicts that the mutual inductance for an unloaded Tesla transformer should be nonreciprocal. This historical curiosity is mostly forgotten today, perhaps because it appears incorrect. However, Drude's prediction is shown to be correct for the conditions treated, demonstrating the importance of constraints in deriving equivalent circuits for distributed systems. The predicted nonreciprocity is not fundamental, but instead is an artifact of the misrepresentation of energy by an equivalent circuit. The application to modern equivalent circuits is discussed. PMID:25542040

  18. Mutual Group Hypnosis: A Social Interaction Analysis.

    ERIC Educational Resources Information Center

    Sanders, Shirley

    Mutual Group Hypnosis is discussed in terms of its similarity to group dynamics in general and in terms of its similarity to a social interaction program (Role Modeling) designed to foster the expression of warmth and acceptance among group members. Hypnosis also fosters a regression to prelogical thought processes in the service of the ego. Group…

  19. Mutual diffusion of interacting membrane proteins.

    PubMed Central

    Abney, J R; Scalettar, B A; Owicki, J C

    1989-01-01

    The generalized Stokes-Einstein equation is used, together with the two-dimensional pressure equation, to analyze mutual diffusion in concentrated membrane systems. These equations can be used to investigate the role that both direct and hydrodynamic interactions play in determining diffusive behavior. Here only direct interactions are explicitly incorporated into the theory at high densities; however, both direct and hydrodynamic interactions are analyzed for some dilute solutions. We look at diffusion in the presence of weak attractions, soft repulsions, and hard-core repulsions. It is found that, at low densities, attractions retard mutual diffusion while repulsions enhance it. Mechanistically, attractions tend to tether particles together and oppose the dissipation of gradients or fluctuations in concentration, while repulsions provide a driving force that pushes particles apart. At higher concentrations, changes in the structure of the fluid enhance mutual diffusion even in the presence of attractions. It is shown that the theoretical description of postelectrophoresis relaxation and fluorescence correlation spectroscopy experiments must be modified if interacting systems are studied. The effects of interactions on mutual diffusion coefficients have probably already been seen in postelectrophoresis relaxation experiments. PMID:2775829

  20. The Genogram: From Diagnostics to Mutual Collaboration.

    ERIC Educational Resources Information Center

    Dunn, Adriana Balaguer; Levitt, Mary Michael

    2000-01-01

    Presents the need for integration of mutual client-therapist collaboration into the process of genogram construction and demonstrates through case examples how such integration enhances the therapeutic power of the genogram. Suggests possible changes in the training of marriage and family therapists in order for such integration to become more…

  1. Phase locking of two limit cycle oscillators with delay coupling

    NASA Astrophysics Data System (ADS)

    Usacheva, S. A.; Ryskin, N. M.

    2014-06-01

    Mutual phase locking in the system of two limit cycle oscillators with delay coupling is studied. Conditions of phase locking are derived as a result of analysis of a generalized Adler equation. The analytical results are compared with numerical simulation. Depending on the phase shift of the coupling signal propagating between the two oscillators, either in-phase or anti-phase mode of synchronization may arise. The number of possible modes of synchronization increases with the delay time.

  2. Lithium diisopropylamide-mediated lithiation of 1,4-difluorobenzene under nonequilibrium conditions: role of monomer-, dimer-, and tetramer-based intermediates and lessons about rate limitation.

    PubMed

    Liang, Jun; Hoepker, Alexander C; Bruneau, Angela M; Ma, Yun; Gupta, Lekha; Collum, David B

    2014-12-19

    Lithiation of 1,4-difluorobenzene with lithium diisopropylamide (LDA) in THF at -78 °C joins the ranks of a growing number of metalations that occur under conditions in which the rates of aggregate exchanges are comparable to the rates of metalation. As such, a substantial number of barriers vie for rate limitation. Rate studies reveal that rate-limiting steps and even the choice of reaction coordinate depend on subtle variations in concentration. Deuteration shifts the rate-limiting step and markedly alters the concentration dependencies and overall rate law. This narrative is less about ortholithiation per se and more about rate limitation and the dynamics of LDA aggregate exchange. PMID:25000303

  3. Lithium Diisopropylamide-Mediated Lithiation of 1,4-Difluorobenzene under Nonequilibrium Conditions: Role of Monomer-, Dimer-, and Tetramer-Based Intermediates and Lessons about Rate Limitation

    PubMed Central

    2015-01-01

    Lithiation of 1,4-difluorobenzene with lithium diisopropylamide (LDA) in THF at ?78 °C joins the ranks of a growing number of metalations that occur under conditions in which the rates of aggregate exchanges are comparable to the rates of metalation. As such, a substantial number of barriers vie for rate limitation. Rate studies reveal that rate-limiting steps and even the choice of reaction coordinate depend on subtle variations in concentration. Deuteration shifts the rate-limiting step and markedly alters the concentration dependencies and overall rate law. This narrative is less about ortholithiation per se and more about rate limitation and the dynamics of LDA aggregate exchange. PMID:25000303

  4. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    PubMed Central

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  5. Methods for automatized detection of rapid changes in lateral boundary condition fields for NWP limited area models

    NASA Astrophysics Data System (ADS)

    Tudor, M.

    2015-03-01

    Three hourly temporal resolution of lateral boundary data can be too low to properly resolve rapidly moving storms. This problem is expected to be worse with increasing horizontal resolution. In order to detect intensive disturbances in surface pressure moving rapidly through the model domain, a filtered surface pressure field (MCUF) is computed operationally in the ARPEGE global model of Météo France. The field is distributed in the coupling files along with conventional meteorological fields used for lateral boundary conditions (LBCs) for the operational forecast using limited area model ALADIN in the Meteorological and hydrological service of Croatia (DHMZ). Here an analysis is performed of the MCUF field for the LACE coupling domain for the period since 23 January 2006, when it became available, until 15 November 2014. The MCUF field is a good indicator of rapidly moving pressure disturbances (RMPDs). Its spatial and temporal distribution can be associated to the usual cyclone tracks and areas known to be supporting cyclogenesis. Other global models do not compute such field. Alternative set of coupling files from IFS operational run in ECMWF is also available operationally in DHMZ with 3 hourly temporal resolution but the MCUF field is not available. Here, several methods are tested that detect RMPDs in surface pressure a posteriori from the IFS model fields provided in the coupling files. MCUF is computed by running ALADIN on the coupling files from IFS. The error function is computed using one time step integration of ALADIN on the coupling files without initialization, initialized with DFI or SSDFI. Finally, the amplitude of changes in the mean sea level pressure is computed from the fields in the coupling files. The results are compared to the MCUF field of ARPEGE and the results of same methods applied to the coupling files from ARPEGE. Most methods give a signal for the rapidly moving pressure disturbances (RMPDs), but DFI reduces the storms too much to be detected. Error function without filtering and amplitude have more noise, but the signal of a RMPD is also stronger. The methods are tested for NWP LAM, but could be applied to and benefit the performance of climate LAMs.

  6. Aerobactin Mediates Virulence and Accounts for Increased Siderophore Production under Iron-Limiting Conditions by Hypervirulent (Hypermucoviscous) Klebsiella pneumoniae

    PubMed Central

    Olson, Ruth; MacDonald, Ulrike; Metzger, Daniel; Maltese, Lauren M.; Drake, Eric J.; Gulick, Andrew M.

    2014-01-01

    Hypervirulent (hypermucoviscous) Klebsiella pneumoniae (hvKP) strains are an emerging variant of “classical” K. pneumoniae (cKP) that cause organ and life-threatening infection in healthy individuals. An understanding of hvKP-specific virulence mechanisms that enabled evolution from cKP is limited. Observations by our group and previously published molecular epidemiologic data led us to hypothesize that hvKP strains produced more siderophores than cKP strains and that this trait enhanced hvKP virulence. Quantitative analysis of 12 hvKP strains in iron-poor minimal medium or human ascites fluid showed a significant and distinguishing 6- to 10-fold increase in siderophore production compared to that for 14 cKP strains. Surprisingly, high-pressure liquid chromatography (HPLC)-mass spectrometry and characterization of the hvKP strains hvKP1, A1142, and A1365 and their isogenic aerobactin-deficient (?iucA) derivatives established that aerobactin accounted for the overwhelming majority of increased siderophore production and that this was not due to gene copy number. Further, aerobactin was the primary factor in conditioned medium that enhanced the growth/survival of hvKP1 in human ascites fluid. Importantly the ex vivo growth/survival of hvKP1 ?iucA was significantly less than that of hvKP1 in human ascites fluid, and the survival of outbred CD1 mice challenged subcutaneously or intraperitoneally with hvKP1 was significantly less than that of mice challenged with hvKP1 ?iucA. The lowest subcutaneous and intraperitoneal challenge inocula of 3 × 102 and 3.2 × 101 CFU, respectively, resulted in 100% mortality, demonstrating the virulence of hvKP1 and its ability to cause infection at a low dose. These data strongly support that aerobactin accounts for increased siderophore production in hvKP compared to cKP (a potential defining trait) and is an important virulence factor. PMID:24664504

  7. Synchronization properties of two self-oscillating semiconductor lasers subject to delayed optoelectronic mutual coupling

    NASA Astrophysics Data System (ADS)

    Vicente, Raúl; Tang, Shuo; Mulet, Josep; Mirasso, Claudio R.; Liu, Jia-Ming

    2006-04-01

    We theoretically investigate the nonlinear dynamics and synchronization properties between two mutually coupled semiconductor lasers units. Each unit can self-oscillate by means of delayed optoelectronic feedback loops. The mutual optoelectronic interactions between the laser units take into account the finite propagation time of the signals. Under perfectly symmetric conditions, we find different “death by delay” islands that persist for instantaneous coupling. The appearance of (zero lag) isochronous chaotic synchronization, under appropriate driving conditions, is another distinctive feature of the delayed feedback loops in the laser units. For slightly asymmetric operation, we obtain frequency locked bands (Arnold Tongue) whose width periodically changes with the coupling delay time.

  8. Hardware device binding and mutual authentication

    DOEpatents

    Hamlet, Jason R; Pierson, Lyndon G

    2014-03-04

    Detection and deterrence of device tampering and subversion by substitution may be achieved by including a cryptographic unit within a computing device for binding multiple hardware devices and mutually authenticating the devices. The cryptographic unit includes a physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a binding PUF value. The cryptographic unit uses the binding PUF value during an enrollment phase and subsequent authentication phases. During a subsequent authentication phase, the cryptographic unit uses the binding PUF values of the multiple hardware devices to generate a challenge to send to the other device, and to verify a challenge received from the other device to mutually authenticate the hardware devices.

  9. Statistical mechanics of mutual information maximization

    NASA Astrophysics Data System (ADS)

    Urbanczik, R.

    2000-03-01

    An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed (Becker S. and Hinton G., Nature, 355 (1992) 161). By exploiting a formal analogy to supervised learning in parity machines, the theory of zero-temperature Gibbs learning for the unsupervised procedure is presented for the case that the networks are perceptrons and for the case of fully connected committees.

  10. Combating isolation: Building mutual mentoring networks

    NASA Astrophysics Data System (ADS)

    Cox, Anne J.

    2015-12-01

    Women physicists can often feel isolated at work. Support from a grant through the ADVANCE program of the National Science Foundation (U.S. government funding) created mutual mentoring networks aimed at combating isolation specifically for women faculty at undergraduate-only institutions. This paper will discuss the organization of one such network, what contributed to its success, some of the outcomes, and how it might be implemented in other contexts.

  11. Observations of Pluto-Charon mutual events

    SciTech Connect

    Blanco, C.; Di Martino, M.; Ferreri, W.; Osservatorio Astronomico, Turin )

    1989-07-01

    As part of the planned 'Pluto-Charon Mutual Eclipse Season Campaign', one mutual event was observed at the ESO Observatory on July 10, 1986 and seven mutual events were observed at the Serra La Nave stellar station of Catania Astrophysical Observatory from April 29 to July 21, 1987. At ESO the measurements were performed at the 61-cm Bochum telescope equipped with a photon-counting system and U, B, V, filters; at Serra La Nave the Cassegrain focus of the 91-cm reflector was equipped with a photon-counting system and B and V filters. The observed light losses and contact times do not show relevant systematic deviations from the predicted ones. An examination of the behavior of the B and V light curves gives slight indications of a different slope of the B and V light loss of the same event for a superior or an inferior event, and shows that the superior events are shallower at wavelengths longer than B. 6 refs.

  12. Trading public goods stabilizes interspecific mutualism.

    PubMed

    Archetti, Marco; Scheuring, István

    2013-02-01

    The existence of cooperation between species raises a fundamental problem for evolutionary theory. Why provide costly services to another species if the feedback of this provision also happens to benefit intra-specific competitors that provide no service? Rewarding cooperators and punishing defectors can help maintain mutualism; this is not possible, however, when one can only respond to the collective action of one's partners, which is likely to be the case in many common symbioses. We show how the theory of public goods can explain the stability of mutualism when discrimination between cooperators and defectors is not possible: if two groups of individuals trade goods that are non-linear, increasing functions of the number of contributions, their mutualistic interaction is maintained by the exchange of these public goods, even when it is not possible to punish defectors, which can persist at relatively high frequencies. This provides a theoretical justification and testable predictions for the evolution of mutualism in the absence of discrimination mechanisms. PMID:23103772

  13. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  14. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 12 2010-04-01 2010-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in section 593(a)....

  15. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 12 2014-04-01 2014-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  16. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 12 2013-04-01 2013-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  17. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Mutual capital certificates. 563.74 Section 563.74 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SAVINGS ASSOCIATIONS-OPERATIONS Securities and Borrowings § 563.74 Mutual capital certificates. (a) General. No savings association that is in the mutual form shall...

  18. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... capital requirements under part 167 of this chapter if a Federal savings association or 12 CFR part 390... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... report stating the number of purchasers. (i) Requirements as to mutual capital certificates—(1) Form...

  19. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... capital requirements under part 167 of this chapter if a Federal savings association or 12 CFR part 390... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... report stating the number of purchasers. (i) Requirements as to mutual capital certificates—(1) Form...

  20. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... capital requirements under part 167 of this chapter if a Federal savings association or 12 CFR part 390... association that is in the mutual form shall issue mutual capital certificates pursuant to this section or... report stating the number of purchasers. (i) Requirements as to mutual capital certificates—(1) Form...

  1. Understanding of polyhydroxybutyrate production under carbon and phosphorus-limited growth conditions in non-axenic continuous culture.

    PubMed

    Cavaillé, Laëtitia; Albuquerque, Maria; Grousseau, Estelle; Lepeuple, Anne-Sophie; Uribelarrea, Jean-Louis; Hernandez-Raquet, Guillermina; Paul, Etienne

    2016-02-01

    In a waste into resource strategy, a selection of polyhydroxybutyrate (PHB)-accumulating organisms from activated sludge was achieved in an open continuous culture under acetic acid and phosphorus limitation. Once the microbial population was selected at a dilution rate (D), an increase in phosphorus limitation degree was applied in order to study the intracellular phosphorus plasticity of selected bacteria and the resulting capacity to produce PHB. Whatever D, all selected populations were able to produce PHB. At a D, the phosphorus availability determined the phosphorus-cell content which in turn fixed the amount of cell. All the remaining carbon was thus directed toward PHB. By decreasing D, microorganisms adapted more easily to higher phosphorus limitation leading to higher PHB content. A one-stage continuous reactor operated at D=0.023h(-)(1) gave reliable high PHB productivity with PHB content up to 80%. A two-stage reactor could ensure better productivity while allowing tuning product quality. PMID:26638135

  2. Competition for cellulose among three predominant ruminal cellulolytic bacteria under substrate-excess and substrate-limited conditions.

    PubMed Central

    Shi, Y; Odt, C L; Weimer, P J

    1997-01-01

    Three predominant ruminal cellulolytic bacteria (Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD-1, and Ruminococcus albus 7) were grown in different binary combinations to determine the outcome of competition in either cellulose-excess batch culture or in cellulose-limited continuous culture. Relative populations of each species were estimated by using signature membrane-associated fatty acids and/or 16S rRNA-targeted oligonucleotide probes. Both F. succinogenes and R. flavefaciens coexisted in cellulose-excess batch culture with similar population sizes (58 and 42%, respectively; standard error, 12%). By contrast, under cellulose limitation R. flavefaciens predominated (> 96% of total cell mass) in coculture with F. succinogenes, regardless of whether the two strains were inoculated simultaneously or whether R. flavefaciens was inoculated into an established culture of F. succinogenes. The predominance of R. flavefaciens over F. succinogenes under cellulose limitation is in accord with the former's more rapid adherence to cellulose and its higher affinity for cellodextrin products of cellulose hydrolysis. In batch cocultures of F. succinogenes and R. albus, the populations of the two species were similar. However, under cellulose limitation, F. succinogenes was the predominant strain (approximately 80% of cell mass) in cultures simultaneously coinoculated with R. albus. The results from batch cocultures of R. flavefaciens and R. albus were not consistent within or among trials: some experiments yielded monocultures of R. albus (suggesting production of an inhibitory agent by R. albus), while others contained substantial populations of both species. Under cellulose limitation, R. flavefaciens predominated over R. albus (85 and 15%, respectively), as would be expected by the former's greater adherence to cellulose. The retention of R. albus in the cellulose-limited coculture may result from a combination of its ability to utilize glucose (which is not utilizable by R. flavefaciens), its demonstrated ability to adapt under selective pressure in the chemostat to utilization of lower concentrations of cellobiose, a major product of cellulose hydrolysis, and its possible production of an inhibitory agent. PMID:9023950

  3. Aggressive mimicry coexists with mutualism in an aphid

    PubMed Central

    Salazar, Adrián; Fürstenau, Benjamin; Quero, Carmen; Pérez-Hidalgo, Nicolás; Carazo, Pau; Font, Enrique; Martínez-Torres, David

    2015-01-01

    Understanding the evolutionary transition from interspecific exploitation to cooperation is a major challenge in evolutionary biology. Ant–aphid relationships represent an ideal system to this end because they encompass a coevolutionary continuum of interactions ranging from mutualism to antagonism. In this study, we report an unprecedented interaction along this continuum: aggressive mimicry in aphids. We show that two morphs clonally produced by the aphid Paracletus cimiciformis during its root-dwelling phase establish relationships with ants at opposite sides of the mutualism–antagonism continuum. Although one of these morphs exhibits the conventional trophobiotic (mutualistic) relationship with ants of the genus Tetramorium, aphids of the alternative morph are transported by the ants to their brood chamber and cared for as if they were true ant larvae. Gas chromatography-mass spectrometry analyses reveal that the innate cuticular hydrocarbon profile of the mimic morph resembles the profile of ant larvae more than that of the alternative, genetically identical nonmimic morph. Furthermore, we show that, once in the brood chamber, mimic aphids suck on ant larva hemolymph. These results not only add aphids to the limited list of arthropods known to biosynthesize the cuticular chemicals of their deceived hosts to exploit their resources but describe a remarkable case of plastic aggressive mimicry. The present work adds a previously unidentified dimension to the classical textbook paradigm of aphid–ant relationships by showcasing a complex system at the evolutionary interface between cooperation and exploitation. PMID:25583474

  4. Classical mutual information in mean-field spin glass models

    NASA Astrophysics Data System (ADS)

    Alba, Vincenzo; Inglis, Stephen; Pollet, Lode

    2016-03-01

    We investigate the classical Rényi entropy Sn and the associated mutual information In in the Sherrington-Kirkpatrick (S-K) model, which is the paradigm model of mean-field spin glasses. Using classical Monte Carlo simulations and analytical tools we investigate the S-K model in the n -sheet booklet. This is achieved by gluing together n independent copies of the model, and it is the main ingredient for constructing the Rényi entanglement-related quantities. We find a glassy phase at low temperatures, whereas at high temperatures the model exhibits paramagnetic behavior, consistent with the regular S-K model. The temperature of the paramagnetic-glassy transition depends nontrivially on the geometry of the booklet. At high temperatures we provide the exact solution of the model by exploiting the replica symmetry. This is the permutation symmetry among the fictitious replicas that are used to perform disorder averages (via the replica trick). In the glassy phase the replica symmetry has to be broken. Using a generalization of the Parisi solution, we provide analytical results for Sn and In and for standard thermodynamic quantities. Both Sn and In exhibit a volume law in the whole phase diagram. We characterize the behavior of the corresponding densities, Sn/N and In/N , in the thermodynamic limit. Interestingly, at the critical point the mutual information does not exhibit any crossing for different system sizes, in contrast with local spin models.

  5. Housekeeping Mutualisms: Do More Symbionts Facilitate Host Performance?

    PubMed Central

    Lemer, Sarah; Leray, Matthieu; Mills, Suzanne C.; Osenberg, Craig W.

    2012-01-01

    Mutualisms often involve one host supporting multiple symbionts, whose identity, density and intraguild interactions can influence the nature of the mutualism and performance of the host. However, the implications of multiple co-occurring symbionts on services to a host have rarely been quantified. In this study, we quantified effects of decapod symbionts on removal of sediment from their coral host. Our field survey showed that all common symbionts typically occur as pairs and never at greater abundances. Two species, the crab Trapezia serenei and the shrimp Alpheus lottini, were most common and co-occurred more often than expected by chance. We conducted a mesocosm experiment to test for effects of decapod identity and density on sediment removal. Alone, corals removed 10% of sediment, but removal increased to 30% and 48% with the presence of two and four symbionts, respectively. Per-capita effects of symbionts were independent of density and identity. Our results suggest that symbiont density is restricted by intraspecific competition. Thus, increased sediment removal from a coral host can only be achieved by increasing the number of species of symbionts on that coral, even though these species are functionally equivalent. Symbiont diversity plays a key role, not through added functionality but by overcoming density limitation likely imposed by intraspecific mating systems. PMID:22523536

  6. Aggressive mimicry coexists with mutualism in an aphid.

    PubMed

    Salazar, Adrián; Fürstenau, Benjamin; Quero, Carmen; Pérez-Hidalgo, Nicolás; Carazo, Pau; Font, Enrique; Martínez-Torres, David

    2015-01-27

    Understanding the evolutionary transition from interspecific exploitation to cooperation is a major challenge in evolutionary biology. Ant-aphid relationships represent an ideal system to this end because they encompass a coevolutionary continuum of interactions ranging from mutualism to antagonism. In this study, we report an unprecedented interaction along this continuum: aggressive mimicry in aphids. We show that two morphs clonally produced by the aphid Paracletus cimiciformis during its root-dwelling phase establish relationships with ants at opposite sides of the mutualism-antagonism continuum. Although one of these morphs exhibits the conventional trophobiotic (mutualistic) relationship with ants of the genus Tetramorium, aphids of the alternative morph are transported by the ants to their brood chamber and cared for as if they were true ant larvae. Gas chromatography-mass spectrometry analyses reveal that the innate cuticular hydrocarbon profile of the mimic morph resembles the profile of ant larvae more than that of the alternative, genetically identical nonmimic morph. Furthermore, we show that, once in the brood chamber, mimic aphids suck on ant larva hemolymph. These results not only add aphids to the limited list of arthropods known to biosynthesize the cuticular chemicals of their deceived hosts to exploit their resources but describe a remarkable case of plastic aggressive mimicry. The present work adds a previously unidentified dimension to the classical textbook paradigm of aphid-ant relationships by showcasing a complex system at the evolutionary interface between cooperation and exploitation. PMID:25583474

  7. 31 CFR 1024.320 - Reports by mutual funds of suspicious transactions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for use in a private legal proceeding, including a request pursuant to 31 CFR 1.11. (e) Limitation on... SAR-SF. The mutual fund shall make all supporting documentation available to FinCEN or any Federal... any suspicious activity report filed with FinCEN pursuant to any regulation in this chapter....

  8. 31 CFR 1024.320 - Reports by mutual funds of suspicious transactions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for use in a private legal proceeding, including a request pursuant to 31 CFR 1.11. (e) Limitation on... SAR-SF. The mutual fund shall make all supporting documentation available to FinCEN or any Federal... any suspicious activity report filed with FinCEN pursuant to any regulation in this chapter....

  9. 31 CFR 1024.320 - Reports by mutual funds of suspicious transactions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for use in a private legal proceeding, including a request pursuant to 31 CFR 1.11. (e) Limitation on... SAR-SF. The mutual fund shall make all supporting documentation available to FinCEN or any Federal... any suspicious activity report filed with FinCEN pursuant to any regulation in this chapter....

  10. 7 CFR 301.76-7 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 301.76-6(b)(1), or with methyl bromide or irradiation, in accordance with 7 CFR part 305 of this... limited permits for regulated articles moved interstate from areas quarantined for citrus greening. 301.76... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus...

  11. 7 CFR 301.76-7 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CFR part 305 of this chapter. (2) The nursery stock is inspected by an inspector in accordance with... limited permits for regulated articles moved interstate from areas quarantined for citrus greening. 301.76... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus...

  12. 7 CFR 301.76-6 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... with methyl bromide in accordance with 7 CFR part 305 of this chapter. (2) The article is shipped in a... treated with irradiation in accordance with 7 CFR part 305 of this chapter at an irradiation facility that... were treated in accordance with 7 CFR part 305 of this chapter. (3) A copy of the limited permit...

  13. 7 CFR 301.76-7 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... accordance with 7 CFR part 305 of this chapter. (2) The nursery stock is inspected by an inspector in... limited permits for regulated articles moved interstate from areas quarantined for citrus greening. 301.76... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus...

  14. 7 CFR 301.76-6 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 3 in accordance with 7 CFR part 305 of this chapter. 3 EPA and State and local environmental... irradiation in accordance with 7 CFR part 305 of this chapter at an irradiation facility that is not located... accordance with 7 CFR part 305 of this chapter. (3) A copy of the limited permit is attached to the...

  15. 7 CFR 301.76-6 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in accordance with 7 CFR part 305 of this chapter. (2) The article is shipped in a container that has... irradiation in accordance with 7 CFR part 305 of this chapter at an irradiation facility that is not located... accordance with 7 CFR part 305 of this chapter. (3) A copy of the limited permit is attached to the...

  16. 7 CFR 301.76-7 - Additional conditions for issuance of certificates and limited permits for regulated articles...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CFR part 305 of this chapter. (2) The nursery stock is inspected by an inspector in accordance with... limited permits for regulated articles moved interstate from areas quarantined for citrus greening. 301.76... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus...

  17. Strategies for maintaining fruit quality in northern highbush blueberry under water limited conditions: deficit irrigation and reduced crop loads

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many commercial blueberry (Vaccinium sp.) fields are irrigated, but mandatory water restrictions may soon limit the availability of irrigation water in several important blueberry growing regions such as California and eastern Washington. New strategies are needed to maintain fruit quality with less...

  18. No evidence of carbon limitation with tree age and height in Nothofagus pumilio under Mediterranean and temperate climate conditions

    PubMed Central

    Piper, Frida I.; Fajardo, Alex

    2011-01-01

    Background and Aims Trees universally decrease their growth with age. Most explanations for this trend so far support the hypothesis that carbon (C) gain becomes limited with age; though very few studies have directly assessed the relative reductions of C gain and C demand with tree age. It has also been suggested that drought enhances the effect of C gain limitation in trees. Here tests were carried out to determine whether C gain limitation is causing the growth decay with tree age, and whether drought accentuates its effect. Methods The balance between C gain and C demand across tree age and height ranges was estimated. For this, the concentration of non-structural carbohydrates (NSCs) in stems and roots of trees of different ages and heights was measured in the deciduous temperate species Nothofagus pumilio. An ontogenetic decrease in NSCs indicates support for C limitation. Furthermore, the importance of drought in altering the C balance with ontogeny was assessed by sampling the same species in Mediterranean and humid climate locations in the southern Andes of Chile. Wood density (WD) and stable carbon isotope ratios (?13C) were also determined to examine drought constraints on C gain. Key Results At both locations, it was effectively found that tree growth ultimately decreased with tree age and height. It was found, however, that NSC concentrations did not decrease with tree age or height when WD was considered, suggesting that C limitation is not the ultimate mechanism causing the age/height-related declining tree growth. ?13C decreased with tree age/height at the Mediterranean site only; drought effect increased with tree age/height, but this pattern was not mirrored by the levels of NSCs. Conclusions The results indicate that concentrations of C storage in N. pumilio trees do not decrease with tree age or height, and that reduced C assimilation due to summer drought does not alter this pattern. PMID:21852277

  19. 40 CFR Appendix L to Subpart A of... - Approved Critical Uses and Limiting Critical Conditions for Those Uses for the 2010 Control Period

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Approved Critical Uses and Limiting Critical Conditions for Those Uses for the 2010 Control Period L Appendix L to Subpart A of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  20. 40 CFR Appendix L to Subpart A of... - Approved Critical Uses and Limiting Critical Conditions for Those Uses for the 2012 Control Period

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Approved Critical Uses and Limiting Critical Conditions for Those Uses for the 2012 Control Period L Appendix L to Subpart A of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  1. 30 CFR 203.42 - What conditions and limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... royalty relief for deep wells and phase 1 ultra-deep wells? 203.42 Section 203.42 Mineral Resources... ROYALTY RATES OCS Oil, Gas, and Sulfur General Royalty Relief for Drilling Deep Gas Wells on Leases Not... deep wells and phase 1 ultra-deep wells? The conditions and limitations in the following table apply...

  2. The Importance of Awareness and Communication for the Inclusion of Young People with Life-Limiting and Life-Threatening Conditions in Mainstream Schools and Colleges

    ERIC Educational Resources Information Center

    Asprey, Anthea; Nash, Tricia

    2006-01-01

    Anthea Asprey and Tricia Nash both belong to the Children's Hospice South West Research Group, based at the University of Exeter. In this article, they report one aspect of a research project designed to determine the adequacy of support for young people with life-limiting and life-threatening conditions in the education system. They describe here…

  3. GENERAL: Bifurcation of a Saddle-Node Limit Cycle with Homoclinic Orbits Satisfying the Small Lobe Condition in a Leech Neuron Model

    NASA Astrophysics Data System (ADS)

    Yooer, Chi-Feng; Xu, Jian-Xue; Zhang, Xin-Hua

    2009-08-01

    Mechanism of period-adding cascades with chaos in a reduced leech neuron model is suggested as the bifurcation of a saddle-node limit cycle with homoclinic orbits satisfying the “small lobe condition", instead of the blue-sky catastrophe. In every spiking adding, the new spike emerges at the end of the spiking phase of the bursters.

  4. The Importance of Awareness and Communication for the Inclusion of Young People with Life-Limiting and Life-Threatening Conditions in Mainstream Schools and Colleges

    ERIC Educational Resources Information Center

    Asprey, Anthea; Nash, Tricia

    2006-01-01

    Anthea Asprey and Tricia Nash both belong to the Children's Hospice South West Research Group, based at the University of Exeter. In this article, they report one aspect of a research project designed to determine the adequacy of support for young people with life-limiting and life-threatening conditions in the education system. They describe here…

  5. 30 CFR 203.42 - What conditions and limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... royalty relief for deep wells and phase 1 ultra-deep wells? 203.42 Section 203.42 Mineral Resources BUREAU... limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells? The conditions and... or deeper, your lease cannot earn an RSV under § 203.41 as a result of drilling any subsequent...

  6. 30 CFR 203.42 - What conditions and limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... royalty relief for deep wells and phase 1 ultra-deep wells? 203.42 Section 203.42 Mineral Resources BUREAU... limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells? The conditions and... or deeper, your lease cannot earn an RSV under § 203.41 as a result of drilling any subsequent...

  7. 30 CFR 203.42 - What conditions and limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... royalty relief for deep wells and phase 1 ultra-deep wells? 203.42 Section 203.42 Mineral Resources BUREAU... limitations apply to royalty relief for deep wells and phase 1 ultra-deep wells? The conditions and... or deeper, your lease cannot earn an RSV under § 203.41 as a result of drilling any subsequent...

  8. 20 CFR 661.310 - Under what limited conditions may a Local Board directly be a provider of core services...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Board directly be a provider of core services, intensive services, or training services, or act as a One... conditions may a Local Board directly be a provider of core services, intensive services, or training services, or act as a One-Stop Operator? (a) A Local Board may not directly provide core services,...

  9. 20 CFR 661.310 - Under what limited conditions may a Local Board directly be a provider of core services...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Board directly be a provider of core services, intensive services, or training services, or act as a One... conditions may a Local Board directly be a provider of core services, intensive services, or training services, or act as a One-Stop Operator? (a) A Local Board may not directly provide core services,...

  10. 20 CFR 661.310 - Under what limited conditions may a Local Board directly be a provider of core services...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Board directly be a provider of core services, intensive services, or training services, or act as a One... conditions may a Local Board directly be a provider of core services, intensive services, or training services, or act as a One-Stop Operator? (a) A Local Board may not directly provide core services,...

  11. 76 FR 12274 - Special Conditions: Bell Helicopter Textron Canada Limited Model 206B and 206L Series Helicopters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ..., teetering main rotor, a 2-blade anti-torque tail rotor, a skid landing gear, and a visual flight rule (VFR... possible failure conditions for this system, and their effect on the continued safe flight and landing of... Methods for Conducting the Safety Assessment Process on civil airborne Systems and Equipment)....

  12. 26 CFR 20.2056(b)-3 - Marital deduction; interest of spouse conditioned on survival for limited period.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate § 20.2056(b)-3 Marital deduction; interest of spouse... decedent to his surviving spouse subject to the condition that she does not die as a result of a common... passed to the spouse would be regarded as a nondeductible interest. If the surviving spouse in fact...

  13. 26 CFR 20.2056(b)-3 - Marital deduction; interest of spouse conditioned on survival for limited period.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate § 20.2056(b)-3 Marital deduction; interest of spouse... decedent to his surviving spouse subject to the condition that she does not die as a result of a common... passed to the spouse would be regarded as a nondeductible interest. If the surviving spouse in fact...

  14. 26 CFR 20.2056(b)-3 - Marital deduction; interest of spouse conditioned on survival for limited period.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate § 20.2056(b)-3 Marital deduction; interest of spouse... decedent to his surviving spouse subject to the condition that she does not die as a result of a common... passed to the spouse would be regarded as a nondeductible interest. If the surviving spouse in fact...

  15. 26 CFR 20.2056(b)-3 - Marital deduction; interest of spouse conditioned on survival for limited period.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate § 20.2056(b)-3 Marital deduction; interest of spouse... decedent to his surviving spouse subject to the condition that she does not die as a result of a common... passed to the spouse would be regarded as a nondeductible interest. If the surviving spouse in fact...

  16. 26 CFR 20.2056(b)-3 - Marital deduction; interest of spouse conditioned on survival for limited period.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate § 20.2056(b)-3 Marital deduction; interest of spouse... decedent to his surviving spouse subject to the condition that she does not die as a result of a common... passed to the spouse would be regarded as a nondeductible interest. If the surviving spouse in fact...

  17. Higher-dimensional orbital-angular-momentum-based quantum key distribution with mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Mafu, Mhlambululi; Dudley, Angela; Goyal, Sandeep; Giovannini, Daniel; McLaren, Melanie; Padgett, Miles J.; Konrad, Thomas; Petruccione, Francesco; Lütkenhaus, Norbert; Forbes, Andrew

    2013-09-01

    We present an experimental study of higher-dimensional quantum key distribution protocols based on mutually unbiased bases, implemented by means of photons carrying orbital angular momentum. We perform (d+1) mutually unbiased measurements in a classically simulated prepare-and-measure scheme and on a pair of entangled photons for dimensions ranging from d=2 to 5. In our analysis, we pay attention to the detection efficiency and photon pair creation probability. As security measures, we determine from experimental data the average error rate, the mutual information shared between the sender and receiver, and the secret key generation rate per photon. We demonstrate that increasing the dimension leads to an increased information capacity as well as higher key generation rates per photon. However, we find that the benefit of increasing the dimension is limited by practical implementation considerations, which in our case results in deleterious effects observed beyond a dimension of d=4.

  18. Metabolic regulation of Escherichia coli and its phoB and phoR genes knockout mutants under phosphate and nitrogen limitations as well as at acidic condition

    PubMed Central

    2011-01-01

    Background The phosphorus compounds serve as major building blocks of many biomolecules, and have important roles in signal transduction. The phosphate is involved in many biochemical reactions by the transfer of phosphoryl groups. All living cells sophisticatedly regulate the phosphate uptake, and survive even under phosphate-limiting condition, and thus phosphate metabolism is closely related to the diverse metabolism including energy and central carbon metabolism. In particular, phosphorylation may play important roles in the metabolic regulation at acidic condition and nitrogen limiting condition, which typically appears at the late growth phase in the batch culture. Moreover, phosphate starvation is a relatively inexpensive means of gene induction in practice, and the phoA promoter has been used for overexpression of heterologous genes. A better understanding of phosphate regulation would allow for optimization of such processes. Results The effect of phosphate (P) concentration on the metabolism in Escherichia coli was investigated in terms of fermentation characteristics and gene transcript levels for the aerobic continuous culture at the dilution rate of 0.2 h-1. The result indicates that the specific glucose consumption rate and the specific acetate production rate significantly increased, while the cell concentration decreased at low P concentration (10% of the M9 medium). The increase in the specific glucose uptake rate may be due to ATP demand caused by limited ATP production under P-limitation. The lower cell concentration was also caused by less ATP production. The less ATP production by H+-ATPase may have caused less cytochrome reaction affecting in quinone pool, and caused up-regulation of ArcA/B, which repressed TCA cycle genes and caused more acetate production. In the case of phoB mutant (and also phoR mutant), the fermentation characteristics were less affected by P-limitation as compared to the wild type where the PhoB regulated genes were down-regulated, while phoR and phoU changed little. The phoR gene knockout caused phoB gene to be down-regulated as well as PhoB regulated genes, while phoU and phoM changed little. The effect of pH together with lower P concentration on the metabolic regulation was also investigated. In accordance with up-regulation of arcA gene expression, the expressions of the TCA cycle genes such as sdhC and mdh were down-regulated at acidic condition. The gene expression of rpoS was up-regulated, and the expression of gadA was up-regulated at pH 6.0. In accordance with this, PhoB regulated genes were up-regulated in the wild type under P-rich and P-limited conditions at pH 6.0 as compared to those at pH 7.0. Moreover, the effect of nitrogen limitation on the metabolic regulation was investigated, where the result indicates that phoB gene was up-regulated, and PhoB regulated genes were also up-regulated under N-limitation, as well as nitrogen-regulated genes. Conclusion The present result shows the complicated nature of the metabolic regulation for the fermentation characteristics upon phosphate limitation, acidic condition, and nitrogen limitation based on the transcript levels of selected genes. The result implies that the regulations under phosphate limitation, acidic condition, and nitrogen limitation, which occur typically at the late growth phase of the batch culture, are interconnected through RpoS and RpoD together with Pho genes. PMID:21599905

  19. Quantum reconstruction of the mutual coherence function.

    PubMed

    Hradil, Z; Rehácek, J; Sánchez-Soto, L L

    2010-07-01

    Light is a major carrier of information about the world around us, from the microcosmos to the macrocosmos. The present methods of detection are sensitive both to robust features, such as intensity, or polarization, and to more subtle effects, such as correlations. Here we show how wave front detection, which allows for registering the direction of the incoming wave flux at a given position, can be used to reconstruct the mutual coherence function when combined with some techniques previously developed for quantum information processing. PMID:20867424

  20. [Revolving door patient in lymphology--possibilities and limits of therapy and patient motivation during inpatient and ambulatory conditions].

    PubMed

    Földi, E

    1999-01-01

    Patients suffering from chronic diseases necessitate a continuous treatment and self-care. Independent from its etiology the method of choice of the treatment of chronic lymphedemas of the limbs is "Complex Decongestive Physiotherapy" (CDP). CDP is carried out according to the requirements either as an outpatient- or an inpatient-treatment. In some cases CDP has to be applied not in its usual, regular form but in a modified manner. The lecture deals with problematic cases and with the limits of our therapeutic possibilities. PMID:10378338

  1. Dwarf and tiller-enhancing 1 regulates growth and development by influencing boron uptake in boron limited conditions in rice.

    PubMed

    Liu, Kai; Liu, Ling-Long; Ren, Yu-Long; Wang, Zhi-Quan; Zhou, Kun-Neng; Liu, Xi; Wang, Dan; Zheng, Ming; Cheng, Zhi-Jun; Lin, Qi-Bing; Wang, Jiu-Lin; Wu, Fu-Qing; Zhang, Xin; Guo, Xiu-Ping; Wang, Chun-Ming; Zhai, Hu-Qu; Jiang, Ling; Wan, Jian-Min

    2015-07-01

    Boron (B) is essential for plant growth, and B deficiency causes severe losses in crop yield. Here we isolated and characterized a rice (Oryza sativa L.) mutant named dwarf and tiller-enhancing 1 (dte1), which exhibits defects under low-B conditions, including retarded growth, increased number of tillers and impaired pollen fertility. Map-based cloning revealed that dte1 encodes a NOD26-LIKE INTRINSIC PROTEIN orthologous to known B channel proteins AtNIP5;1 in Arabidopsis and TASSEL-LESS1 in maize. Its identity was verified by transgenic complementation and RNA-interference. Subcellular localization showed DTE1 is mainly localized in the plasma membrane. The accumulation of DTE1 transcripts both in roots and shoots significantly increased within 3h of the onset of B starvation, but decreased within 1h of B replenishment. GUS staining indicated that DTE1s are expressed abundantly in exodermal cells in roots, as well as in nodal region of adult leaves. Although the dte1 mutation apparently reduces the total B content in plants, it does not affect in vivo B concentrations under B-deficient conditions. These data provide evidence that DTE1 is critical for vegetative growth and reproductive development in rice grown under B-deficient conditions. PMID:26025517

  2. Evolutionary dynamics with fluctuating population sizes and strong mutualism

    NASA Astrophysics Data System (ADS)

    Chotibut, Thiparat; Nelson, David R.

    2015-08-01

    Game theory ideas provide a useful framework for studying evolutionary dynamics in a well-mixed environment. This approach, however, typically enforces a strictly fixed overall population size, deemphasizing natural growth processes. We study a competitive Lotka-Volterra model, with number fluctuations, that accounts for natural population growth and encompasses interaction scenarios typical of evolutionary games. We show that, in an appropriate limit, the model describes standard evolutionary games with both genetic drift and overall population size fluctuations. However, there are also regimes where a varying population size can strongly influence the evolutionary dynamics. We focus on the strong mutualism scenario and demonstrate that standard evolutionary game theory fails to describe our simulation results. We then analytically and numerically determine fixation probabilities as well as mean fixation times using matched asymptotic expansions, taking into account the population size degree of freedom. These results elucidate the interplay between population dynamics and evolutionary dynamics in well-mixed systems.

  3. RF Pulses for In Vivo Spectroscopy at High Field Designed under Conditions of Limited Power Using Optimal Control

    PubMed Central

    Matson, Gerald B.; Young, Karl; Kaiser, Lana G.

    2009-01-01

    Localized in vivo spectroscopy at high magnetic field strength (> 3 T) is susceptible to localization artifacts such as the chemical shift artifact and the spatial interference artifact for J-coupled spins. This latter artifact results in regions of anomalous phase for J-coupled spins. These artifacts are exacerbated at high magnetic field due to the increased frequency dispersion, coupled with the limited RF pulse bandwidths used for localization. Approaches to minimize these artifacts include increasing the bandwidth of the frequency selective excitation pulses, and the use of frequency selective saturation pulses to suppress the signals in the regions with anomalous phase. The goal of this article is to demonstrate the efficacy of optimal control methods to provide broader bandwidth frequency selective pulses for in vivo spectroscopy in the presence of limited RF power. It is demonstrated by examples that the use of optimal control methods enable the generation of i) improved bandwidth selective excitation pulses, ii) more efficient selective inversion pulses to be used for generation of spin echoes, and iii) improved frequency selective saturation pulses. While optimal control also allows for the generation of frequency selective spin echo pulses, it is argued that it is more efficient to use dual inversion pulses for broadband generation of spin echoes. Finally, the optimal control routines and example RF pulses are made available for downloading. PMID:19398359

  4. Effects of tungsten and titanium oxide nanoparticles on the diazotrophic growth and metals acquisition by Azotobacter vinelandii under molybdenum limiting condition.

    PubMed

    Allard, Patrick; Darnajoux, Romain; Phalyvong, Karine; Bellenger, Jean-Philippe

    2013-02-19

    The acquisition of essential metals, such as the metal cofactors (molybdenum (Mo) and iron (Fe)) of the nitrogenase, the enzyme responsible for the reduction of dinitrogen (N(2)) to ammonium, is critical to N(2) fixing bacteria in soil. The release of metal nanoparticles (MNPs) to the environment could be detrimental to N(2) fixing bacteria by introducing a new source of toxic metals and by interfering with the acquisition of essential metals such as Mo. Since Mo has been reported to limit nonsymbiotic N(2) fixation in many ecosystems from tropical to cold temperate, this question is particularly acute in the context of Mo limitation. Using a combination of microbiology and analytical chemistry techniques, we have evaluated the effect of titanium (Ti) and tungsten (W) oxide nanoparticles on the diazotrophic growth and metals acquisition in pure culture of the ubiquitous N(2) fixing bacterium Azotobacter vinelandii under Mo replete and Mo limiting conditions. We report that under our conditions (?10 mg·L(-1)) TiO(2) NPs have no effects on the diazotrophic growth of A. vinelandii while WO(3) NPs are highly detrimental to the growth especially under Mo limiting conditions. Our results show that the toxicity of WO(3) NPs to A. vinelandii is due to an interference with the catechol-metalophores assisted uptake of Mo. PMID:23339336

  5. Collective Dynamics on a Two-Lane Asymmetrically Coupled TASEP with Mutually Interactive Langmuir Kinetics

    NASA Astrophysics Data System (ADS)

    Gupta, Arvind Kumar

    2016-03-01

    Motivated by the recent experimental observations on clustering of motor proteins on microtubule filament, we study an open system of two parallel totally asymmetric simple exclusion processes under asymmetric coupling conditions, which incorporates the mutual interaction with the surrounding environment through Langmuir Kinetics (LK) in both the lanes. In the modified LK, the attachment and detachment rates depends on the configuration of nearest neighboring sites. We analyse the model within the framework of continuum mean-field theory and the phase diagrams along with density profiles are obtained using boundary layer analysis. The effect of mutual interactions on the phase diagram for two different situations of attachment and detachment (LK) rates is discussed. Under the symmetric LK dynamics, the topological structure of the phase diagram remains similar to the one in without mutual interaction; while for the antisymmetric case, after a certain critical value of attractive/repulsive mutual attraction, significant changes are found in the qualitative nature of phase diagram. Moreover, it is shown that the type of mutual interaction affects the dynamic properties of motor proteins. The theoretical findings are examined by extensive Monte-Carlo simulations.

  6. A Method for Rapid Determination of the Icing Limit of a Body in Terms of the Stream Conditions

    NASA Technical Reports Server (NTRS)

    Callaghan, Edmund E.; Serafini, John S.

    1953-01-01

    The effects of existing frictional heating were analyzed to determine the conditions under which ice formations on aircraft surfaces can be prevented. A method is presented for rapidly determining by means of charts the combination of-Mach number, altitude, and stream temperature which will maintain an ice-free surface in an icing cloud. The method can be applied to both subsonic and supersonic flow. The charts presented are for Mach numbers up to 1.8 and pressure altitudes from sea level to 45,000 feet.

  7. Generalized mutual information of quantum critical chains

    NASA Astrophysics Data System (ADS)

    Alcaraz, F. C.; Rajabpour, M. A.

    2015-04-01

    We study the generalized mutual information I˜n of the ground state of different critical quantum chains. The generalized mutual information definition that we use is based on the well established concept of the Rényi divergence. We calculate this quantity numerically for several distinct quantum chains having either discrete Z (Q ) symmetries (Q -state Potts model with Q =2 ,3 ,4 and Z (Q ) parafermionic models with Q =5 ,6 ,7 ,8 and also Ashkin-Teller model with different anisotropies) or the U (1 ) continuous symmetries (Klein-Gordon field theory, X X Z and spin-1 Fateev-Zamolodchikov quantum chains with different anisotropies). For the spin chains these calculations were done by expressing the ground-state wave functions in two special bases. Our results indicate some general behavior for particular ranges of values of the parameter n that defines I˜n. For a system, with total size L and subsystem sizes ? and L -? , the I˜n has a logarithmic leading behavior given by c/˜n4 log[L/? sin(?/? L ) ] where the coefficient c˜n is linearly dependent on the central charge c of the underlying conformal field theory describing the system's critical properties.

  8. Tectonic drift versus climatic variations: rhodoliths as indicators of limits between tropical and nontropical sedimentary conditions: examples from Pacific Miocene

    SciTech Connect

    Bourrouilh-le Jan, F.G.

    1986-05-01

    Modern examples show that rhodoliths or red algal nodules are forming around the 18/sup 0/C winter isocline and that huge amounts of these red coralline algae are living and accumulating in the subtidal zones, from -60 m to sea level, of temperate seas, such as the English Channel and Rockall. In the Pacific Ocean, several high carbonate platforms, so-called uplifted atolls, show uniform, extended, and thick accumulation of rhodoliths. These accumulations have been recognized in the Solomon Islands (Rennell) and in the Loyalty Islands (Mare and Lifu, New Caledonia), but also in the Vanuatu (Vila), in the Austral Archipelago (Rurutu), where their age can be proved or estimated as middle Miocene. They are also mentioned in the literature on the Emperor Rise (northwest Pacific). On other high carbonate islands, such as Makatea (Tuamotu), red algae and rhodolith formations appear at the top of a sedimentary pile of lower Miocene coral accumulation. The same observations and perhaps the same age can be said for Nauru (central Pacific). Such a wide distribution, from the east to the west part of the Pacific Ocean and between the tropics, seems to be due to climate variations during the Miocene, more than tectonic drift due to oceanic spreading. Temperate conditions shown by this shallow platform sedimentation, just under the coral growth conditions, seem to be confirmed by isotopic studies on pelagic and benthic Foraminifera and could confirm the existence of climate variations affecting the surface water of the Pacific in an extensive area that does not consider the presence of trenches, arcs, and ridges.

  9. Tenax extraction for exploring rate-limiting factors in methyl-?-cyclodextrin enhanced anaerobic biodegradation of PAHs under denitrifying conditions in a red paddy soil.

    PubMed

    Sun, Mingming; Ye, Mao; Hu, Feng; Li, Huixin; Teng, Ying; Luo, Yongming; Jiang, Xin; Kengara, Fredrick Orori

    2014-01-15

    The effectiveness of anaerobic bioremediation systems for PAH-contaminated soil may be constrained by low contaminants bioaccessibility due to limited aqueous solubility and lack of suitable electron acceptors. Information on what is the rate-limiting factor in bioremediation process is of vital importance in the decision in what measures can be taken to assist the biodegradation efficacy. In the present study, four different microcosms were set to study the effect of methyl-?-cyclodextrin (MCD) and nitrate addition (N) on PAHs biodegradation under anaerobic conditions in a red paddy soil. Meanwhile, sequential Tenax extraction combined with a first-three-compartment model was employed to evaluate the rate-limiting factors in MCD enhanced anaerobic biodegradation of PAHs. Microcosms with both 1% (w/w) MCD and 20mM N addition produced maximum biodegradation of total PAHs of up to 61.7%. It appears rate-limiting factors vary with microcosms: low activity of degrading microorganisms is the vital rate-limiting factor for control and MCD addition treatments (CK and M treatments); and lack of bioaccessible PAHs is the main rate-limiting factor for nitrate addition treatments (N and MN treatments). These results have practical implications for site risk assessment and cleanup strategies. PMID:24239261

  10. Final Rules for Grandfathered Plans, Preexisting Condition Exclusions, Lifetime and Annual Limits, Rescissions, Dependent Coverage, Appeals, and Patient Protections Under the Affordable Care Act. Final rules.

    PubMed

    2015-11-18

    This document contains final regulations regarding grandfathered health plans, preexisting condition exclusions, lifetime and annual dollar limits on benefits, rescissions, coverage of dependent children to age 26, internal claims and appeal and external review processes, and patient protections under the Affordable Care Act. It finalizes changes to the proposed and interim final rules based on comments and incorporates subregulatory guidance issued since publication of the proposed and interim final rules. PMID:26595941

  11. The transcriptional activator NrpA is crucial for inducing nitrogen fixation in Methanosarcina mazei Gö1 under nitrogen-limited conditions.

    PubMed

    Weidenbach, Katrin; Ehlers, Claudia; Schmitz, Ruth A

    2014-08-01

    With the aim of unraveling their potential involvement in the regulation of nitrogen metabolism in Methanosarcina mazei strain Gö1, we characterized five genes that are differentially transcribed in response to changing nitrogen availability and encoding putative transcriptional regulators. Study of the respective mutant strains under nitrogen-limited conditions revealed a growth delay for M. mazei MM0444::pac and MM1708::pac, and strongly reduced diazotrophic growth for MM0872::pac, whereas the absence of MM2441 or MM2525 did not affect growth behaviour. Transcriptome analyses further demonstrated that only MM1708 - encoding a CxxCG zinc finger protein - plays a regulatory role in nitrogen metabolism, most likely by specifically enhancing transcription of the N2 fixation (nif) operon under nitrogen-limited conditions. In agreement with this, a palindromic binding motif was predicted in silico in the nifH promoter region, nine nucleotides upstream of the BRE box, and confirmed to bind purified maltose-binding protein-MM1708 by electromobility shift assays. As MM1708 itself is under the control of the global nitrogen repressor NrpR, this adds a secondary level to the transcriptional regulation of the nif genes, and is most likely crucial for maximal nif induction under nitrogen-limited conditions. This is in accordance with the finding that protein expression of NifH is highly reduced in the absence of MM1708 under nitrogen-limited conditions. On the basis of our findings, we hypothesize that, in M. mazei, nitrogen fixation is controlled by a hierarchical network of two transcriptional regulators, the global nitrogen repressor NrpR, and the newly identified activator NrpA (MM1708), thereby providing tight control of N2 fixation. PMID:24930989

  12. Nitrogen availability impacts oilseed rape (Brassica napus L.) plant water status and proline production efficiency under water-limited conditions.

    PubMed

    Albert, Benjamin; Le Cahérec, Françoise; Niogret, Marie-Françoise; Faes, Pascal; Avice, Jean-Christophe; Leport, Laurent; Bouchereau, Alain

    2012-08-01

    Large amounts of nitrogen (N) fertilizers are used in the production of oilseed rape. However, as low-input methods of crop management are introduced crops will need to withstand temporary N deficiency. In temperate areas, oilseed rape will also be affected by frequent drought periods. Here we evaluated the physiological and metabolic impact of nitrate limitation on the oilseed rape response to water deprivation. Different amounts of N fertilizer were applied to plants at the vegetative stage, which were then deprived of water and rehydrated. Both water and N depletion accelerated leaf senescence and reduced leaf development. N-deprived plants exhibited less pronounced symptoms of wilting during drought, probably because leaves were smaller and stomata were partially closed. Efficiency of proline production, a major stress-induced diversion of nitrogen metabolism, was assessed at different positions along the whole plant axis and related to leaf developmental stage and water status indices. Proline accumulation, preferentially in younger leaves, accounted for 25-85% of the free amino acid pool. This was mainly due to a better capacity for proline synthesis in fully N-supplied plants whether they were subjected to drought or not, as deduced from the expression patterns of the proline metabolism BnP5CS and BnPDH genes. Although less proline accumulated in the oldest leaves, a significant amount was transported from senescing to emerging leaves. Moreover, during rehydration proline was readily recycled. Our results therefore suggest that proline plays a significant role in leaf N remobilization and in N use efficiency in oilseed rape. PMID:22526495

  13. Analysis of influenza virus hemagglutinin receptor binding mutants with limited receptor recognition properties and conditional replication characteristics.

    PubMed

    Bradley, Konrad C; Galloway, Summer E; Lasanajak, Yi; Song, Xuezheng; Heimburg-Molinaro, Jamie; Yu, Hai; Chen, Xi; Talekar, Ganesh R; Smith, David F; Cummings, Richard D; Steinhauer, David A

    2011-12-01

    To examine the range of selective processes that potentially operate when poorly binding influenza viruses adapt to replicate more efficiently in alternative environments, we passaged a virus containing an attenuating mutation in the hemagglutinin (HA) receptor binding site in mice and characterized the resulting mutants with respect to the structural locations of mutations selected, the replication phenotypes of the viruses, and their binding properties on glycan microarrays. The initial attenuated virus had a tyrosine-to-phenylalanine mutation at HA1 position 98 (Y98F), located in the receptor binding pocket, but viruses that were selected contained second-site pseudoreversion mutations in various structural locations that revealed a range of molecular mechanisms for modulating receptor binding that go beyond the scope that is generally mapped using receptor specificity mutants. A comparison of virus titers in the mouse respiratory tract versus MDCK cells in culture showed that the mutants displayed distinctive replication properties depending on the system, but all were less attenuated in mice than the Y98F virus. An analysis of receptor binding properties confirmed that the initial Y98F virus bound poorly to several different species of erythrocytes, while all mutants reacquired various degrees of hemagglutination activity. Interestingly, both the Y98F virus and pseudoreversion mutants were shown to bind very inefficiently to standard glycan microarrays containing an abundance of binding substrates for most influenza viruses that have been characterized to date, provided by the Consortium for Functional Glycomics. The viruses were also examined on a recently developed microarray containing glycans terminating in sialic acid derivatives, and limited binding to a potentially interesting subset of glycans was revealed. The results are discussed with respect to mechanisms for HA-mediated receptor binding, as well as regarding the species of molecules that may act as receptors for influenza virus on host cell surfaces. PMID:21917953

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

    PubMed

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

    2016-01-01

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

  15. Traitement des conditions aux limites intérieures et extérieures pour la simulation numérique unidimensionnelle de l'écoulement de l'eau dans les canaux à surface libre

    NASA Astrophysics Data System (ADS)

    Abdallah, M.; Vazquez, J.; Mose, R.; Zoaeter, M.

    2005-05-01

    Dans ce papier, on décrit le traitement des conditions aux limites intérieures et extérieures couplé avec la méthode explicite aux différences finies de Roe pour le développement d'une modélisation unidimensionnelle qui sert à résoudre les équations de Saint-Venant décrivant l'écoulement de l'eau à surface libre. Les deux méthodes les plus utilisées pour trouver la solution aux nœuds intérieurs et extérieurs définissant les conditions aux limites intérieures et extérieures d'un schéma numérique sont décrites et comparées dans deux exemples: Le premier traite le problème du ressaut hydraulique et le second décrit l'écoulement de l'eau au dessus des seuils. Deux types de discrétisation du terme source, pointwise et upwind, sont considérés et comparés aussi. Les résultats obtenus et comparés avec la solution analytique dans le cas du ressaut, et avec les résultats numériques déjà publiés dans le cas des seuils, montrent l'avantage de la méthode des caractéristiques sur la méthode de l'extrapolation pour les conditions aux limites, et la discrétisation upwind du terme source sur la discrétisation pointwise.

  16. Hubble Space Telescope Observations of Haumea during a Predicted Mutual Event

    NASA Astrophysics Data System (ADS)

    Ragozzine, Darin; Brown, M. E.

    2010-10-01

    The dwarf planet Haumea is one of the most interesting objects in the solar system with a highly elliptical shape, two moons, and as the progenitor or the only known collisional family in the Kuiper belt. Despite being one of the most well-observed objects beyond Neptune, some of Haumea's basic properties (e.g., density) are poorly known or based on model assumptions. Through a fortuitous alignment of the inner satellite, Namaka, we can significantly improve our understanding of this important body with a detailed characterization of a Haumea-Namaka mutual event. Similarly to the information-rich Pluto-Charon mutual events, the Haumea-Namaka mutual events promise to reveal an accurate size, shape, albedo, density, and spin pole orientation of Haumea, along with a measurement of the size, albedo, and density of the inner satellite Namaka, and improved orbits of both Namaka and Hi'iaka (through measuring perturbations on Namaka's orbit). Although entirely fulfilling these goals requires observing several mutual events, the single well-characterized mutual event we attempted to observe will provide valuable first steps in this direction and will provide crucial timing information required for intrepretation of other events, past and future. So far, ground based observations have been limited by systematic errors (such as the unknown but significant light curve of Hi'iaka). We have obtained Hubble Space Telescope observations of Haumea during the June 28, 2010 mutual event, predicted to be a nearly central transit of Haumea by Namaka and a grazing shadow-transit. We have confirmed that HST has successfully observed Haumea and its satellites in 270 45-second exopsures spanning 10 orbits ( 15 hours). We will present photometric and astrometric analyses of these data and discuss their implications for Haumea. This work is based on NASA/ESA Hubble Space Telescope program 12243 and is supported by NASA with grants from the Space Telescope Science Institute.

  17. Limited BDNF contributes to the failure of injury to skin afferents to produce a neuropathic pain condition.

    PubMed

    Zhou, Li-Jun; Ren, Wen-Jie; Zhong, Yi; Yang, Tao; Wei, Xu-Hong; Xin, Wen-Jun; Liu, Cui-Cui; Zhou, Li-Hua; Li, Yong-Yong; Liu, Xian-Guo

    2010-01-01

    Although a large body of evidence has shown that peripheral nerve injury usually induces neuropathic pain, there are also clinical studies demonstrating that injury of the sural nerve, which almost only innervates skin, fails to do so. The underlying mechanism, however, is largely unknown. In the present work, we found that the transection of either the gastrocnemius-soleus (GS) nerve innervating skeletal muscle or tibial nerve supplying both muscle and skin, but not of the sural nerve produced a lasting mechanical allodynia and thermal hyperalgesia in adult rats. High-frequency stimulation (HFS) or injury of either the tibial nerve or the GS nerve induced late-phase long-term potentiation (L-LTP) of C-fiber-evoked field potentials in spinal dorsal horn, while HFS or injury of the sural nerve only induced early-phase LTP (E-LTP). Furthermore, HFS of the tibial nerve induced L-LTP of C-fiber responses evoked by the stimulation of the sural nerve and the heterotopic L-LTP was completely prevented by spinal application of TrkB-Fc (a BDNF scavenger). Spinal application of low dose BDNF (10pg/ml) enabled HFS of the sural nerve to produce homotopic L-LTP. Finally, we found that injury of the GS nerve but not that of the sural nerve up-regulated BDNF in DRG neurons, and that the up-regulation of BDNF occurred not only in injured neurons but also in many uninjured ones. Therefore, the sural nerve injury failing to produce neuropathic pain may be due to the nerve containing insufficient BDNF under both physiological and pathological conditions. PMID:19945222

  18. Mutual information-based facial expression recognition

    NASA Astrophysics Data System (ADS)

    Hazar, Mliki; Hammami, Mohamed; Hanêne, Ben-Abdallah

    2013-12-01

    This paper introduces a novel low-computation discriminative regions representation for expression analysis task. The proposed approach relies on interesting studies in psychology which show that most of the descriptive and responsible regions for facial expression are located around some face parts. The contributions of this work lie in the proposition of new approach which supports automatic facial expression recognition based on automatic regions selection. The regions selection step aims to select the descriptive regions responsible or facial expression and was performed using Mutual Information (MI) technique. For facial feature extraction, we have applied Local Binary Patterns Pattern (LBP) on Gradient image to encode salient micro-patterns of facial expressions. Experimental studies have shown that using discriminative regions provide better results than using the whole face regions whilst reducing features vector dimension.

  19. Mutual recognition between ewes and lambs.

    PubMed

    Walser, E S; Alexander, G

    1980-01-01

    Studies to investigate the relative value of sight, hearing and smell in mutual recognition between ewes and lambs are described. The method used was to alter clues that could aid in recognition, rather than interfering with the animal's sensory perception. When lambs were coloured with powdered dyes to change appearance, this produced marked avoidance by the dams of the treated lambs. When lambs were partially coloured, the ewes' greatest reaction was shown to lambs whose heads were coloured. Other experiments compared the role of vision and hearing by observing recognition when the ewes or lambs were hidden behind screening, or muted. The results indicate that while olfaction is important for recognition when the ewe and lamb are close together, visual clues are of major importance in maternal discrimination and auditory clues are important for the lambs as they get older. PMID:7349447

  20. Propagating Resource Constraints Using Mutual Exclusion Reasoning

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Sanchez, Romeo; Do, Minh B.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds for jobs using discrete multi-capacity resources. In this paper we show how mutual exclusion reasoning can be used to propagate time bounds for activities using discrete resources. We show that our technique based on critical path analysis and mutex reasoning is just as effective on unary resources, and also shows that it is more effective on multi-capacity resources, through both examples and empirical study.

  1. Improvement of seed yields under boron-limiting conditions through overexpression of BOR1, a boron transporter for xylem loading, in Arabidopsis thaliana.

    PubMed

    Miwa, Kyoko; Takano, Junpei; Fujiwara, Toru

    2006-06-01

    Soil fertilization is a common practice in modern agriculture, undertaken to prevent nutrient deficiency in crops. However, fertilization is costly and causes environmental pollution. The cultivation of plants that tolerate low nutrient supplies may circumvent this problem. Here, we report the generation of Arabidopsis thaliana plants that tolerate boron (B)-deficient conditions due to the overexpression of BOR1, an efflux B transporter that is required for efficient xylem loading of B. In several independently generated transgenic plants expressing BOR1 or BOR1-GFP under the control of the cauliflower mosaic virus 35S RNA promoter, root-to-shoot translocation of B was enhanced and shoot growth was greater under B-limiting conditions compared with wild-type plants. In addition, the transgenic plants showed increased translocation of B, especially to the shoot apex, and set seed normally under B-limiting conditions, under which wild-type plants failed to set seed. This study therefore reports plants that show improved seed yields compared with wild-type under nutrient-deficient conditions as a result of increased production of an essential mineral nutrient transporter. PMID:16805739

  2. On the Mutual Coupling Between Circular Resonant Slots

    NASA Technical Reports Server (NTRS)

    Abou-Khousa, M. A.; Kharkovsky, S.; Zoughi, R.

    2007-01-01

    For near- and far-field microwave imaging purposes, array of circular resonant slots can be utilized to sample the electric field at a given reference plane. In general, the sensitivity of such array probes is impaired by the mutual coupling present between the radiating elements. The mutual coupling problem poses a design tradeoff between the resolution of the array and its sensitivity. In this paper, we investigate the mutual coupling between circular resonant slots in conducting ground plane both numerically and experimentally. Based on the analysis of the dominant coupling mechanism, i.e., the surface currents, various remedies to reduce the slots' mutual coupling are proposed and verified.

  3. Mutual inactivation of Notch receptors and ligands facilitates developmental patterning.

    PubMed

    Sprinzak, David; Lakhanpal, Amit; LeBon, Lauren; Garcia-Ojalvo, Jordi; Elowitz, Michael B

    2011-06-01

    Developmental patterning requires juxtacrine signaling in order to tightly coordinate the fates of neighboring cells. Recent work has shown that Notch and Delta, the canonical metazoan juxtacrine signaling receptor and ligand, mutually inactivate each other in the same cell. This cis-interaction generates mutually exclusive sending and receiving states in individual cells. It generally remains unclear, however, how this mutual inactivation and the resulting switching behavior can impact developmental patterning circuits. Here we address this question using mathematical modeling in the context of two canonical pattern formation processes: boundary formation and lateral inhibition. For boundary formation, in a model motivated by Drosophila wing vein patterning, we find that mutual inactivation allows sharp boundary formation across a broader range of parameters than models lacking mutual inactivation. This model with mutual inactivation also exhibits robustness to correlated gene expression perturbations. For lateral inhibition, we find that mutual inactivation speeds up patterning dynamics, relieves the need for cooperative regulatory interactions, and expands the range of parameter values that permit pattern formation, compared to canonical models. Furthermore, mutual inactivation enables a simple lateral inhibition circuit architecture which requires only a single downstream regulatory step. Both model systems show how mutual inactivation can facilitate robust fine-grained patterning processes that would be difficult to implement without it, by encoding a difference-promoting feedback within the signaling system itself. Together, these results provide a framework for analysis of more complex Notch-dependent developmental systems. PMID:21695234

  4. On the Mutual Coupling between Circular Resonant Slots

    NASA Technical Reports Server (NTRS)

    Abou-Khousa, M. A.; Kharkovshy, S.; Zoughi, R.

    2007-01-01

    For near- and far-field microwave imaging purposes, array of circular resonant slots can be utilized to sample the electric field at a given reference plane. In general, the sensitivity of such an array is impaired by the existing mutual coupling between the radiating elements or in this case circular slots. The mutual coupling problem imposes a design tradeoff between the resolution of the array and the overall system sensitivity and dynamic range. In this paper, the mutual coupling between circular resonant slots in conducting ground plane is investigated both numerically and experimentally. In particular, the mutual coupling in the E- and H-plane configurations of two identical slots is studied.

  5. Mutualism fails when climate response differs between interacting species.

    TOXLINE Toxicology Bibliographic Information

    Warren RJ 2nd; Bradford MA

    2014-02-01

    Successful species interactions require that both partners share a similar cue. For many species, spring warming acts as a shared signal to synchronize mutualist behaviors. Spring flowering plants and the ants that disperse their seeds respond to warming temperatures so that ants forage when plants drop seeds. However, where warm-adapted ants replace cold-adapted ants, changes in this timing might leave early seeds stranded without a disperser. We investigate plant seed dispersal south and north of a distinct boundary between warm- and cold-adapted ants to determine if changes in the ant species influence local plant dispersal. The warm-adapted ants forage much later than the cold-adapted ants, and so we first assess natural populations of early and late blooming plants. We then transplant these plants south and north of the ant boundary to test whether distinct ant climate requirements disrupt the ant-plant mutualism. Whereas the early blooming plant's inability to synchronize with the warm-adapted ant leaves its populations clumped and patchy and its seedlings clustered around the parents in natural populations, when transplanted into the range of the cold-adapted ant, effective seed dispersal recovers. In contrast, the mutualism persists for the later blooming plant regardless of location because it sets seed later in spring when both warm- and cold-adapted ant species forage, resulting in effective seed dispersal. These results indicate that the climate response of species interactions, not just the species themselves, is integral in understanding ecological responses to a changing climate. Data linking phenological synchrony and dispersal are rare, and these results suggest a viable mechanism by which a species' range is limited more by biotic than abiotic interactions - despite the general assumption that biotic influences are buried within larger climate drivers. These results show that biotic partner can be as fundamental a niche requirement as abiotic resources.

  6. Mutualism fails when climate response differs between interacting species.

    PubMed

    Warren, Robert J; Bradford, Mark A

    2014-02-01

    Successful species interactions require that both partners share a similar cue. For many species, spring warming acts as a shared signal to synchronize mutualist behaviors. Spring flowering plants and the ants that disperse their seeds respond to warming temperatures so that ants forage when plants drop seeds. However, where warm-adapted ants replace cold-adapted ants, changes in this timing might leave early seeds stranded without a disperser. We investigate plant seed dispersal south and north of a distinct boundary between warm- and cold-adapted ants to determine if changes in the ant species influence local plant dispersal. The warm-adapted ants forage much later than the cold-adapted ants, and so we first assess natural populations of early and late blooming plants. We then transplant these plants south and north of the ant boundary to test whether distinct ant climate requirements disrupt the ant-plant mutualism. Whereas the early blooming plant's inability to synchronize with the warm-adapted ant leaves its populations clumped and patchy and its seedlings clustered around the parents in natural populations, when transplanted into the range of the cold-adapted ant, effective seed dispersal recovers. In contrast, the mutualism persists for the later blooming plant regardless of location because it sets seed later in spring when both warm- and cold-adapted ant species forage, resulting in effective seed dispersal. These results indicate that the climate response of species interactions, not just the species themselves, is integral in understanding ecological responses to a changing climate. Data linking phenological synchrony and dispersal are rare, and these results suggest a viable mechanism by which a species' range is limited more by biotic than abiotic interactions - despite the general assumption that biotic influences are buried within larger climate drivers. These results show that biotic partner can be as fundamental a niche requirement as abiotic resources. PMID:24399754

  7. Mutual Stabilization of Rhythmic Vocalization and Whole-Body Movement

    PubMed Central

    Miyata, Kohei; Kudo, Kazutoshi

    2014-01-01

    The current study investigated the rhythmic coordination between vocalization and whole-body movement. Previous studies have reported that spatiotemporal stability in rhythmic movement increases when coordinated with a rhythmic auditory stimulus or other effector in a stable coordination pattern. Therefore, the present study conducted two experiments to investigate (1) whether there is a stable coordination pattern between vocalization and whole-body movement and (2) whether a stable coordination pattern reduces variability in whole-body movement and vocalization. In Experiment 1, two coordination patterns between vocalizations and whole-body movement (hip, knee, and ankle joint flexion-on-the-voice vs. joint extension-on-the-voice) in a standing posture were explored at movement frequencies of 80, 130, and 180 beats per minute. At higher movement frequencies, the phase angle in the extension-on-the-voice condition deviated from the intended phase angle. However, the angle of the flexion-on-the-voice was maintained even when movement frequency increased. These results suggest that there was a stable coordination pattern in the flexion-on-the-voice condition. In Experiment 2, variability in whole-body movement and voice-onset intervals was compared between two conditions: one related to tasks performed in the flexion-on-the-voice coordination (coordination condition) that was a stable coordination pattern, and the other related to tasks performed independently (control condition). The results showed that variability in whole-body movement and voice-onset intervals was smaller in the coordination condition than in the control condition. Overall, the present study revealed mutual stabilization between rhythmic vocalization and whole-body movement via coordination within a stable pattern, suggesting that coupled action systems can act as a single functional unit or coordinative structure. PMID:25502730

  8. Practical image registration concerns overcome by the weighted and filtered mutual information metric

    NASA Astrophysics Data System (ADS)

    Keane, Tommy P.; Saber, Eli; Rhody, Harvey; Savakis, Andreas; Raj, Jeffrey

    2012-04-01

    Contemporary research in automated panorama creation utilizes camera calibration or extensive knowledge of camera locations and relations to each other to achieve successful results. Research in image registration attempts to restrict these same camera parameters or apply complex point-matching schemes to overcome the complications found in real-world scenarios. This paper presents a novel automated panorama creation algorithm by developing an affine transformation search based on maximized mutual information (MMI) for region-based registration. Standard MMI techniques have been limited to applications with airborne/satellite imagery or medical images. We show that a novel MMI algorithm can approximate an accurate registration between views of realistic scenes of varying depth distortion. The proposed algorithm has been developed using stationary, color, surveillance video data for a scenario with no a priori camera-to-camera parameters. This algorithm is robust for strict- and nearly-affine-related scenes, while providing a useful approximation for the overlap regions in scenes related by a projective homography or a more complex transformation, allowing for a set of efficient and accurate initial conditions for pixel-based registration.

  9. Online analysis of single cyanobacteria and algae cells under nitrogen-limited conditions using aerosol time-of-flight mass spectrometry.

    PubMed

    Cahill, John F; Darlington, Thomas K; Fitzgerald, Christine; Schoepp, Nathan G; Beld, Joris; Burkart, Michael D; Prather, Kimberly A

    2015-08-18

    Metabolomics studies typically perform measurements on populations of whole cells which provide the average representation of a collection of many cells. However, key mechanistic information can be lost using this approach. Investigating chemistry at the single cell level yields a more accurate representation of the diversity of populations within a cell sample; however, this approach has many analytical challenges. In this study, an aerosol time-of-flight mass spectrometer (ATOFMS) was used for rapid analysis of single algae and cyanobacteria cells with diameters ranging from 1 to 8 ?m. Cells were aerosolized by nebulization and directly transmitted into the ATOFMS. Whole cells were determined to remain intact inside the instrument through a combination of particle sizing and imaging measurements. Differences in cell populations were observed after perturbing Chlamydomonas reinhardtii cells via nitrogen deprivation. Thousands of single cells were measured over a period of 4 days for nitrogen-replete and nitrogen-limited conditions. A comparison of the single cell mass spectra of the cells sampled under the two conditions revealed an increase in the dipalmitic acid sulfolipid sulfoquinovosyldiacylglycerol (SQDG), a chloroplast membrane lipid, under nitrogen-limited conditions. Single cell peak intensity distributions demonstrate the ability of the ATOFMS to measure metabolic differences of single cells. The ATOFMS provides an unprecedented maximum throughput of 50 Hz, enabling the rapid online measurement of thousands of single cell mass spectra. PMID:26237223

  10. Multimodal Registration via Mutual Information Incorporating Geometric and Spatial Context

    PubMed Central

    Woo, Jonghye; Stone, Maureen; Prince, Jerry L.

    2015-01-01

    Multimodal image registration is a class of algorithms to find correspondence from different modalities. Since different modalities do not exhibit the same characteristics, finding accurate correspondence still remains a challenge. In order to deal with this, mutual information (MI) based registration has been a preferred choice as MI is based on the statistical relationship between both volumes to be registered. However, MI has some limitations. First, MI based registration often fails when there are local intensity variations in the volumes. Second, MI only considers the statistical intensity relationships between both volumes and ignores the spatial and geometric information about the voxel. In this work, we propose to address these limitations by incorporating spatial and geometric information via a 3D Harris operator. Specifically, we focus on the registration between a high-resolution image and a low-resolution image. The MI cost function is computed in the regions where there are large spatial variations such as corner or edge. In addition, the MI cost function is augmented with geometric information derived from the 3D Harris operator applied to the high-resolution image. The robustness and accuracy of the proposed method were demonstrated using experiments on synthetic and clinical data including the brain and the tongue. The proposed method provided accurate registration and yielded better performance over standard registration methods. PMID:25561595

  11. Ungulate saliva inhibits a grass–endophyte mutualism

    PubMed Central

    Tanentzap, Andrew J.; Vicari, Mark; Bazely, Dawn R.

    2014-01-01

    Fungal endophytes modify plant–herbivore interactions by producing toxic alkaloids that deter herbivory. However, studies have neglected the direct effects herbivores may have on endophytes. Antifungal properties and signalling effectors in herbivore saliva suggest that evolutionary pressures may select for animals that mitigate the effects of endophyte-produced alkaloids. Here, we tested whether saliva of moose (Alces alces) and European reindeer (Rangifer tarandus) reduced hyphal elongation and production of ergot alkaloids by the foliar endophyte Epichloë festucae associated with the globally distributed red fescue Festuca rubra. Both moose and reindeer saliva reduced the growth of isolated endophyte hyphae when compared with a treatment of distilled water. Induction of the highly toxic alkaloid ergovaline was also inhibited in plants from the core of F. rubra's distribution when treated with moose saliva following simulated grazing. In genotypes from the southern limit of the species' distribution, ergovaline was constitutively expressed, as predicted where growth is environmentally limited. Our results now present the first evidence, to our knowledge, that ungulate saliva can combat plant defences produced by a grass–endophyte mutualism. PMID:25055816

  12. Ungulate saliva inhibits a grass-endophyte mutualism.

    PubMed

    Tanentzap, Andrew J; Vicari, Mark; Bazely, Dawn R

    2014-07-01

    Fungal endophytes modify plant-herbivore interactions by producing toxic alkaloids that deter herbivory. However, studies have neglected the direct effects herbivores may have on endophytes. Antifungal properties and signalling effectors in herbivore saliva suggest that evolutionary pressures may select for animals that mitigate the effects of endophyte-produced alkaloids. Here, we tested whether saliva of moose (Alces alces) and European reindeer (Rangifer tarandus) reduced hyphal elongation and production of ergot alkaloids by the foliar endophyte Epichloë festucae associated with the globally distributed red fescue Festuca rubra. Both moose and reindeer saliva reduced the growth of isolated endophyte hyphae when compared with a treatment of distilled water. Induction of the highly toxic alkaloid ergovaline was also inhibited in plants from the core of F. rubra's distribution when treated with moose saliva following simulated grazing. In genotypes from the southern limit of the species' distribution, ergovaline was constitutively expressed, as predicted where growth is environmentally limited. Our results now present the first evidence, to our knowledge, that ungulate saliva can combat plant defences produced by a grass-endophyte mutualism. PMID:25055816

  13. A Comprehensive Approach to Assess Arabidopsis Survival Phenotype in Water-Limited Condition Using a Non-invasive High-Throughput Phenomics Platform.

    PubMed

    Vello, Emilio; Tomita, Akiko; Diallo, Amadou Oury; Bureau, Thomas E

    2015-01-01

    With the rapid rise in global population and the challenges caused by climate changes, the maximization of plant productivity and the development of sustainable agriculture strategies are vital for food security. One of the resources more affected in this new environment will be the limitation of water. In this study, we describe the use of non-invasive technologies exploiting sensors for visible, fluorescent, and near-infrared lights to accurately screen survival phenotypes in Arabidopsis thaliana exposed to water-limited conditions. We implemented two drought protocols and a robust analysis methodology that enabled us to clearly assess the wilting or dryness status of the plants at different time points using a phenomics platform. In conclusion, our approach has shown to be very accurate and suitable for experiments where hundred of samples have to be screened making a manual evaluation unthinkable. This approach can be used not only in functional genomics studies but also in agricultural applications. PMID:26697051

  14. A Comprehensive Approach to Assess Arabidopsis Survival Phenotype in Water-Limited Condition Using a Non-invasive High-Throughput Phenomics Platform

    PubMed Central

    Vello, Emilio; Tomita, Akiko; Diallo, Amadou Oury; Bureau, Thomas E.

    2015-01-01

    With the rapid rise in global population and the challenges caused by climate changes, the maximization of plant productivity and the development of sustainable agriculture strategies are vital for food security. One of the resources more affected in this new environment will be the limitation of water. In this study, we describe the use of non-invasive technologies exploiting sensors for visible, fluorescent, and near-infrared lights to accurately screen survival phenotypes in Arabidopsis thaliana exposed to water-limited conditions. We implemented two drought protocols and a robust analysis methodology that enabled us to clearly assess the wilting or dryness status of the plants at different time points using a phenomics platform. In conclusion, our approach has shown to be very accurate and suitable for experiments where hundred of samples have to be screened making a manual evaluation unthinkable. This approach can be used not only in functional genomics studies but also in agricultural applications. PMID:26697051

  15. Mutuality, Self-Silencing, and Disordered Eating in College Women

    ERIC Educational Resources Information Center

    Wechsler, Lisa S.; Riggs, Shelley A.; Stabb, Sally D.; Marshall, David M.

    2006-01-01

    The current study examined patterns of association among mutuality, self-silencing, and disordered eating in an ethnically diverse sample of college women (N = 149). Partner mutuality and overall self-silencing were negatively correlated and together were associated with six disordered eating indices. All four self-silencing subscales were…

  16. 76 FR 35084 - Mutual to Stock Conversion Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ... Office of Thrift Supervision Mutual to Stock Conversion Application AGENCY: Office of Thrift Supervision... following information collection. Title of Proposal: Mutual to Stock Conversion Application. OMB Number... of all information furnished in the application in order to determine the safety and soundness of...

  17. Social Climate Comparison of Mutual Help and Psychotherapy Groups.

    ERIC Educational Resources Information Center

    Toro, Paul A.; Rappaport, Julian

    In recent years, mutual help groups have been formed to address problems in substance abuse, chronic physical illness, mental illness, marital disruption, and child abuse. Despite the proliferation of these groups, little research has been conducted to assess their efficacy or what happens in them. The nature of mutual help groups (N=32) was…

  18. Mutuality, Self-Silencing, and Disordered Eating in College Women

    ERIC Educational Resources Information Center

    Wechsler, Lisa S.; Riggs, Shelley A.; Stabb, Sally D.; Marshall, David M.

    2006-01-01

    The current study examined patterns of association among mutuality, self-silencing, and disordered eating in an ethnically diverse sample of college women (N = 149). Partner mutuality and overall self-silencing were negatively correlated and together were associated with six disordered eating indices. All four self-silencing subscales were…

  19. 47 CFR 22.131 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Procedures for mutually exclusive applications...) (according to the filing dates) as acceptable for filing. (4) Window filing group. A window filing group comprises mutually exclusive applications whose filing date is within an announced filing window....

  20. Plant chemical defence: a partner control mechanism stabilising plant - seed-eating pollinator mutualisms

    PubMed Central

    Ibanez, Sébastien; Gallet, Christiane; Dommanget, Fanny; Després, Laurence

    2009-01-01

    Background Mutualisms are inherently conflictual as one partner always benefits from reducing the costs imposed by the other. Despite the widespread recognition that mutualisms are essentially reciprocal exploitation, there are few documented examples of traits that limit the costs of mutualism. In plant/seed-eating pollinator interactions the only mechanisms reported so far are those specific to one particular system, such as the selective abortion of over-exploited fruits. Results This study shows that plant chemical defence against developing larvae constitutes another partner sanction mechanism in nursery mutualisms. It documents the chemical defence used by globeflower Trollius europaeus L. (Ranunculaceae) against the seed-eating larvae of six pollinating species of the genus Chiastocheta Pokorny (Anthomyiidae). The correlative field study carried out shows that the severity of damage caused by Chiastocheta larvae to globeflower fruits is linked to the accumulation in the carpel walls of a C-glycosyl-flavone (adonivernith), which reduces the larval seed predation ability per damaged carpel. The different Chiastocheta species do not exploit the fruit in the same way and their interaction with the plant chemical defence is variable, both in terms of induction intensity and larval sensitivity to adonivernith. Conclusion Adonivernith accumulation and larval predation intensity appear to be both the reciprocal cause and effect. Adonivernith not only constitutes an effective chemical means of partner control, but may also play a key role in the sympatric diversification of the Chiastocheta genus. PMID:19887006

  1. Reducing Deviance Through Youths' Mutual Aid Group Dynamics.

    PubMed

    Cheung, Chau-Kiu; Ngai, Steven Sek-Yum

    2016-01-01

    The mutual aid group, as supported by the social worker, emerges to play a vital role in helping group members reduce their deviance or behavioral problem. However, how the collaboration of the group and social worker accomplishes the reduction has remained uncharted. Based on social capital theory, mutual aid and cohesion within the group and social workers' specific aid for the group are likely responsible for the reduction. The test of such hypotheses relies on a two-wave panel survey of the members of 60 mutual aid groups who had deviant behavioral problems, located in Hong Kong, China. These groups had 241 youths completing both initial and 1-year follow-up surveys. Results manifested the direct or unconditional contributions of mutual aid, group cohesion, and social workers' specific aid to reducing deviance. Hence, social workers can enhance the effectiveness of the mutual aid group in reducing youths' deviance. PMID:25169973

  2. Effect of Fuel Composition, Engine Operating Variables, and Spark-Plug Type and Condition on Preignition-Limited Performance of an R-2800 Cylinder

    NASA Technical Reports Server (NTRS)

    Pfender, John F.

    1946-01-01

    The preignition characteristics of the R-2800 cylinder, as effected by fuel consumption, engine operating variables, and spark plug type and condition, were evaluated. The effects on preignition-limited performance of various percentages of aromatics (benzene, toluene, cumene, xylene) in a base fuel of triptane were investigated. Two paraffins (triptane and S + 6.0 ml TEL/gal) and two refinery blends (28-R and 33-R) were preignition rated. The effect of changes in the following engine operating variables on preignition limit was determined: inlet-air temperature, rear spark plug gasket temperature, engine speed, spark advance, tappet clearance, and oil consumption. Preignition limits of the R-2800 cylinder using Champion C34S and C35S and AC-LS86, LS87, and LS88 spark plugs were established and the effect of spark plug deterioration was investigated. No definite trends in preignition-limited indicated mean effective pressure were indicated for aromatics as a class when increased percentages of different aromatics were added to a base fuel of triptane. Three types of fuel (aromatics, paraffins, and refinery blends) showed a preignition range for this cylinder from 65 to 104 percent when based on the performance of S plus 6.0 ml TEL per gallon as 100 percent. The R-2800 cylinder is therefore relatively insensitive to fuel composition when compared to a CFR F-4 engine, which had a pre-ignition range from 72 to 100 percent for the same fuels. Six engine operating variables were investigated with the following results: preignition-limited indicated mean effective pressure decreased, with increases in engine speed, rear spark plug gasket temperature, inlet-air temperature, and spark advance beyond 20 F B.T.C. and was unaffected by rate of oil consumption or by tappet clearance. Spark plugs were rated over a range of preignition-limited indicated mean effective pressure from 200 to 390 pounds per square inch at a fuel-air ratio of 0.07 in the following order of increased resistance to preignition: AC-LS97, AC-LS88, Champion C358, AC-LS86, and Champion C34S. Spark plug deterioration in the form of cracks in the porcelain had been broken away from the center electrode and were retained in the spark plug cavity, the preignition limit was decreased as much as 57 percent. When the broken pieces had been removed, the preignition limit increased from that of the undamaged porcelain as the weight of removed porcelain was increased.

  3. Calcium and ROS: A mutual interplay

    PubMed Central

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-01-01

    Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca2+ signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. PMID:26296072

  4. [Mutual inhibition between positive and negative emotions].

    PubMed

    Shimokawa, A

    1994-02-01

    The purpose of this study is to examine the relationship between positive and negative emotions. In study 1, 62 emotional items were selected in order to measure subjective emotional experiences. In study 2, comics, photos and poems were randomly presented to 1,220 college students to induce emotion. Subjects were asked to rate their momentary emotional intensity on two set of 5-point scales (general emotional intensity scale and 62 specific emotional intensity scale). In analysis 1, positive correlations were suggested between general emotional intensity scale and some of the specific emotional intensity scales which were activated by stimuli. In analysis 2, 10 positive and 10 negative emotional items were extracted from 62 items by factor analysis. In analysis 3, 4 and 5, it became clear that the distribution of frequency of correlations of 10 positive x 10 negative items changed according to the general emotional intensity scale. That is, from low to moderate levels of GEIS, the two kinds of emotion had no or slightly positive correlation, but at high level they became to be negatively correlated. From the facts described above, it is concluded that positive and negative emotions is not always independent, but show mutual inhibition in case of high intensity level of one of each emotions. PMID:8201808

  5. Calcium and ROS: A mutual interplay.

    PubMed

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-12-01

    Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca(2+) signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. PMID:26296072

  6. Quantum mutual information along unitary orbits

    NASA Astrophysics Data System (ADS)

    Jevtic, Sania; Jennings, David; Rudolph, Terry

    2012-05-01

    Motivated by thermodynamic considerations, we analyze the variation of the quantum mutual information on a unitary orbit of a bipartite system's state with and without global constraints such as energy conservation. We solve the full optimization problem for the smallest system of two qubits and explore thoroughly the effect of unitary operations on the space of reduced-state spectra. We then provide applications of these ideas to physical processes within closed quantum systems such as a generalized collision model approach to thermal equilibrium and a global Maxwell demon playing tricks on local observers. For higher dimensions, the maximization of correlations is relatively straightforward for equal-sized subsystems, however their minimization displays nontrivial structures. We characterize a set of separable states in which the minimally correlated state resides: a collection of classically correlated states admitting a particular “Young tableau” form. Furthermore, a partial order exists on this set with respect to individual marginal entropies, and the presence of a “see-saw effect” for these entropies forces a finer analysis to determine the optimal tableau.

  7. OD(X/sup 2/II) and SD(X/sup 2/II) from reactions of D atoms with OCS under bulk and precursor geometry limited conditions

    SciTech Connect

    Haeusler, D.; Rice, J.; Wittig, C.

    1987-10-08

    Reactions of D atoms with OCS were studied by 193-nm pulsed laser photolysis of DBr as a nearly monoenergetic D-atom source. Nascent OD(X/sup 2/II) and SD(X/sup 2/II) rotational, vibrational, spin-orbit, and ..lambda..-doublet populations were obtained under single-collision bulk conditions at 300 K. The SD channel is favored energetically (..delta.. H = -43 +/- 13 and 230 +/- 13 kJ mol/sup -1/ for the SD and OD channels, respectively) and is the dominant pathway ((SD)/(OD) = 5 +/- 2). Nascent OD(X/sup 2/II) products were also obtained from a precursor geometry limited (PGL) reaction by using the weakly bound van der Waals complex SCO-DBr. The OD(X/sup 2/II) rotational distributions are the same for both bulk and PGL conditions and can be reproduced by using a statistical model. Due to experimental difficulties, SD(X/sup 2/II) distributions could not be obtained under PGL conditions. The SD(X/sup 2/II) distribution obtained under bulk conditions is very nonstatistical, suggesting that this species is not formed via a long-lived DSCO intermediate complex in which vibrational energy is randomized.

  8. Controls on dissolved organic matter (DOM) degradation in a headwater stream: the influence of photochemical and hydrological conditions in determining light-limitation or substrate-limitation of photo-degradation

    NASA Astrophysics Data System (ADS)

    Cory, R. M.; Harrold, K. H.; Neilson, B. T.; Kling, G. W.

    2015-11-01

    We investigated how absorption of sunlight by chromophoric dissolved organic matter (CDOM) controls the degradation and export of DOM from Imnavait Creek, a beaded stream in the Alaskan Arctic. We measured concentrations of dissolved organic carbon (DOC), as well as concentrations and characteristics of CDOM and fluorescent dissolved organic matter (FDOM), during ice-free periods of 2011-2012 in the pools of Imnavait Creek and in soil waters draining to the creek. Spatial and temporal patterns in CDOM and FDOM in Imnavait Creek were analyzed in conjunction with measures of DOM degradation by sunlight and bacteria and assessments of hydrologic residence times and in situ UV exposure. CDOM was the dominant light attenuating constituent in the UV and visible portion of the solar spectrum, with high attenuation coefficients ranging from 86 ± 12 m-1 at 305 nm to 3 ± 1 m-1 in the photosynthetically active region (PAR). High rates of light absorption and thus light attenuation by CDOM contributed to thermal stratification in the majority of pools in Imnavait Creek under low-flow conditions. In turn, thermal stratification increased the residence time of water and DOM, and resulted in a separation of water masses distinguished by contrasting UV exposure (i.e., UV attenuation by CDOM with depth resulted in bottom waters receiving less UV than surface waters). When the pools in Imnavait Creek were stratified, DOM in the pool bottom water closely resembled soil water DOM in character, while the concentration and character of DOM in surface water was reproduced by experimental photo-degradation of bottom water. These results, in combination with water column rates of DOM degradation by sunlight and bacteria, suggest that photo-degradation is the dominant process controlling DOM fate and export in Imnavait Creek. A conceptual model is presented showing how CDOM amount and lability interact with incident UV light and water residence time to determine whether photo-degradation is "light-limited" or "substrate-limited". We suggest that degradation of DOM in CDOM-rich streams or ponds similar to Imnavait is typically light-limited under most flow conditions. Thus, export of DOM from this stream will be less under conditions that increase the light available for DOM photo-degradation (i.e., low flows, sunny days).

  9. Impact of spatial distribution on the development of mutualism in microbes

    PubMed Central

    Kovács, Ákos T.

    2014-01-01

    The evolution of mutualism is one of the long-standing puzzles in evolutionary biology. Why would an individual contribute to the group at the expense of its own fitness? Individual bacterial cells cooperate by secreting products that are beneficial for the community, but costly to produce. It has been shown that cooperation is critical for microbial communities, most notably in biofilms, however, the degree of cooperation strongly depends on the culturing conditions. Spatial community structure provides a solution how cooperation might develop and remain stable. This perspective paper discusses recent progresses on experiments that use microbes to understand the role of spatial distribution on the stability of intraspecific cooperation from an evolutionary point of view and also highlights the effect of mutualism on spatial segregation. Recent publications in this area will be highlighted, which suggest that while mechanisms that allow assortment help to maintain cooperative traits, strong mutualism actually promotes population intermixing. Microbes provide simple and suitable systems to examine the features that define population organization and mutualism. PMID:25505463

  10. Mechanism of Lithium Diisopropylamide-Mediated Ortholithiation of 1,4-Bis(trifluoromethyl)benzene under Nonequilibrium Conditions: Condition-Dependent Rate Limitation and Lithium Chloride-Catalyzed Inhibition.

    PubMed

    Liang, Jun; Hoepker, Alexander C; Algera, Russell F; Ma, Yun; Collum, David B

    2015-05-20

    Lithiation of 1,4-bis(trifluoromethyl)benzene with lithium diisopropylamide in tetrahydrofuran at -78 °C occurs under conditions at which the rates of aggregate exchanges are comparable to the rates of metalation. Under such nonequilibrium conditions, a substantial number of barriers compete to be rate limiting, making the reaction sensitive to trace impurities (LiCl), reactant concentrations, and isotopic substitution. Rate studies using the perdeuterated arene reveal odd effects of LiCl, including catalyzed rate acceleration at lower temperature and catalyzed rate inhibition at higher temperatures. The catalytic effects are accompanied by corresponding changes in the rate law. A kinetic model is presented that captures the critical features of the LiCl catalysis, focusing on the influence of LiCl-catalyzed re-aggregation of the fleeting monomer that can reside above, at, or below the equilibrium population without catalyst. PMID:25900574

  11. Flux Analysis of the Metabolism of Clostridium cellulolyticum Grown in Cellulose-Fed Continuous Culture on a Chemically Defined Medium under Ammonium-Limited Conditions

    PubMed Central

    Desvaux, Mickaël; Petitdemange, Henri

    2001-01-01

    An investigation of cellulose degradation by the nonruminal, cellulolytic, mesophilic bacterium Clostridium cellulolyticum was performed in cellulose-fed chemostat cultures with ammonium as the growth-limiting nutrient. At any dilution rate (D), acetate was always the main product of the catabolism, with a yield of product from substrate ranging between 37.7 and 51.5 g per mol of hexose equivalent fermented and an acetate/ethanol ratio always higher than 1. As D rose, the acetyl coenzyme A was rerouted in favor of ethanol pathways, and ethanol production could represent up to 17.7% of the carbon consumed. Lactate was significantly produced, but with increasing D, the specific lactate production rate declined, as did the specific rate of production of extracellular pyruvate. The proportion of the original carbon directed towards phosphoglucomutase remained constant, and the carbon surplus was balanced mainly by exopolysaccharide and glycogen biosyntheses at high D values, while cellodextrin excretion occurred mainly at lower ones. With increasing D, the specific rate of carbon flowing down catabolites increased as well, but when expressed as a percentage of carbon it declined, while the percentage of carbon directed through biosynthesis pathways was enhanced. The maximum growth and energetic yields were lower than those obtained in cellulose-limited chemostats and were related to an uncoupling between catabolism and anabolism leading to an excess of energy. Compared to growth on cellobiose in ammonium-limited chemostats (E. Guedon, M. Desvaux, and H. Petitdemange, J. Bacteriol. 182:2010–2017, 2000), (i) a specific consumption rate of carbon of as high as 26.72 mmol of hexose equivalent g of cells?1 h?1 could not be reached and (ii) the proportions of carbon directed towards cellodextrin, glycogen, and exopolysaccharide pathways were not as high as first determined on cellobiose. While the use of cellobiose allows highlighting of metabolic limitation and regulation of C. cellulolyticum under ammonium-limited conditions, some of these events should then rather be interpreted as distortions of the metabolism. Growth of cellulolytic bacteria on easily available carbon and nitrogen sources represents conditions far different from those of the natural lignocellulosic compounds. PMID:11525976

  12. Phycobilisome-Deficient Strains of Synechocystis sp. PCC 6803 Have Reduced Size and Require Carbon-Limiting Conditions to Exhibit Enhanced Productivity1[W][OPEN

    PubMed Central

    Lea-Smith, David J.; Bombelli, Paolo; Dennis, John S.; Scott, Stuart A.; Smith, Alison G.; Howe, Christopher J.

    2014-01-01

    Reducing excessive light harvesting in photosynthetic organisms may increase biomass yields by limiting photoinhibition and increasing light penetration in dense cultures. The cyanobacterium Synechocystis sp. PCC 6803 harvests light via the phycobilisome, which consists of an allophycocyanin core and six radiating rods, each with three phycocyanin (PC) discs. Via targeted gene disruption and alterations to the promoter region, three mutants with two (pcpcT?C) and one (?CpcC1C2:pcpcT?C) PC discs per rod or lacking PC (olive) were generated. Photoinhibition and chlorophyll levels decreased upon phycobilisome reduction, although greater penetration of white light was observed only in the PC-deficient mutant. In all strains cultured at high cell densities, most light was absorbed by the first 2 cm of the culture. Photosynthesis and respiration rates were also reduced in the ?CpcC1C2:pcpcT?C and olive mutants. Cell size was smaller in the pcpcT?C and olive strains. Growth and biomass accumulation were similar between the wild-type and pcpcT?C under a variety of conditions. Growth and biomass accumulation of the olive mutant were poorer in carbon-saturated cultures but improved in carbon-limited cultures at higher light intensities, as they did in the ?CpcC1C2:pcpcT?C mutant. This study shows that one PC disc per rod is sufficient for maximal light harvesting and biomass accumulation, except under conditions of high light and carbon limitation, and two or more are sufficient for maximal oxygen evolution. To our knowledge, this study is the first to measure light penetration in bulk cultures of cyanobacteria and offers important insights into photobioreactor design. PMID:24760817

  13. Phycobilisome-Deficient Strains of Synechocystis sp. PCC 6803 Have Reduced Size and Require Carbon-Limiting Conditions to Exhibit Enhanced Productivity.

    PubMed

    Lea-Smith, David J; Bombelli, Paolo; Dennis, John S; Scott, Stuart A; Smith, Alison G; Howe, Christopher J

    2014-04-23

    Reducing excessive light harvesting in photosynthetic organisms may increase biomass yields by limiting photoinhibition and increasing light penetration in dense cultures. The cyanobacterium Synechocystis sp. PCC 6803 harvests light via the phycobilisome, which consists of an allophycocyanin core and six radiating rods, each with three phycocyanin (PC) discs. Via targeted gene disruption and alterations to the promoter region, three mutants with two (pcpcT?C) and one (?CpcC1C2:pcpcT?C) PC discs per rod or lacking PC (olive) were generated. Photoinhibition and chlorophyll levels decreased upon phycobilisome reduction, although greater penetration of white light was observed only in the PC-deficient mutant. In all strains cultured at high cell densities, most light was absorbed by the first 2 cm of the culture. Photosynthesis and respiration rates were also reduced in the ?CpcC1C2:pcpcT?C and olive mutants. Cell size was smaller in the pcpcT?C and olive strains. Growth and biomass accumulation were similar between the wild-type and pcpcT?C under a variety of conditions. Growth and biomass accumulation of the olive mutant were poorer in carbon-saturated cultures but improved in carbon-limited cultures at higher light intensities, as they did in the ?CpcC1C2:pcpcT?C mutant. This study shows that one PC disc per rod is sufficient for maximal light harvesting and biomass accumulation, except under conditions of high light and carbon limitation, and two or more are sufficient for maximal oxygen evolution. To our knowledge, this study is the first to measure light penetration in bulk cultures of cyanobacteria and offers important insights into photobioreactor design. PMID:24760817

  14. Feature selection using mutual information based uncertainty measures for tumor classification.

    PubMed

    Sun, Lin; Xu, Jiucheng

    2014-01-01

    Feature selection is a key problem in tumor classification and related tasks. This paper presents a tumor classification approach with neighborhood rough set-based feature selection. First, some uncertainty measures such as neighborhood entropy, conditional neighborhood entropy, neighborhood mutual information and neighborhood conditional mutual information, are introduced to evaluate the relevance between genes and related decision in neighborhood rough set. Then some important properties and propositions of these measures are investigated, and the relationships among these measures are established as well. By using improved minimal-Redundancy-Maximal-Relevancy, combined with sequential forward greedy search strategy, a novel feature selection algorithm with low time complexity is proposed. Finally, several cancer classification tasks are demonstrated using the proposed approach. Experimental results show that the proposed algorithm is efficient and effective. PMID:24211962

  15. EXPERTS 1—experiences of long-term life-limiting conditions among patients and carers: protocol for a qualitative meta-synthesis and conceptual modelling study

    PubMed Central

    May, Carl R; Masters, Jayne; Welch, Lindsay; Hunt, Katherine; Pope, Catherine; Myall, Michelle; Griffiths, Peter; Roderick, Paul; Glanville, Julie; Richardson, Alison

    2015-01-01

    Introduction Increasing numbers of the population are living with long-term life-limiting conditions with a significant proportion characterised by multimorbidity. Patients with these conditions often experience high volumes of clinical interaction involving them, their caregivers and healthcare providers in complex patterns of organising, coordinating, negotiating and managing care. A better understanding of the sources of experienced complexity and multimorbidity, from the patient perspective is paramount to improve capacity and manage workload to promote improved experience of illness, more effective healthcare utilisation and improved healthcare outcomes. To better understand the sources of complexity we will undertake an evidence synthesis of qualitative studies of patient and informal carer experiences of three common long-term life-limiting conditions. We will investigate what is known about these diseases at different stages in disease progression, treatment regimens and places of care. Method and analysis We will include qualitative studies of patients’ and carers’ (aged >18) accounts of their experiences of healthcare provision in a range of settings and healthcare systems. We will conduct an extensive electronic database search of publications in English between 2000 and 2014. Results and discussions sections of the papers will be regarded as formal data using the constant comparison method of qualitative analysis. From the meta-synthesis results, we will build a conceptual model of mechanisms and processes that shape patients’ journeys towards end of life to suggest where in the patient journey new interventions to improve patient and carer experience can be developed and delivered. The study is being conducted between 1 December 2014 and 31 December 2015. Ethics and dissemination No human subjects or personal data are involved and no ethical issues are anticipated. An important element of dissemination is informing user communities about the practical implications of the work through workshops, meetings and social media. Scientific results will be published in peer reviewed journals and disseminated through conferences. Trial registration number PROSPERO CRD42014014547. PMID:25838511

  16. Population dynamics and the ecological stability of obligate pollination mutualisms

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2001-01-01

    Mutualistic interactions almost always produce both costs and benefits for each of the interacting species. It is the difference between gross benefits and costs that determines the net benefit and the per-capita effect on each of the interacting populations. For example, the net benefit of obligate pollinators, such as yucca and senita moths, to plants is determined by the difference between the number of ovules fertilized from moth pollination and the number of ovules eaten by the pollinator's larvae. It is clear that if pollinator populations are large, then, because many eggs are laid, costs to plants are large, whereas, if pollinator populations are small, gross benefits are low due to lack of pollination. Even though the size and dynamics of the pollinator population are likely to be crucial, their importance has been neglected in the investigation of mechanisms, such as selective fruit abortion, that can limit costs and increase net benefits. Here, we suggest that both the population size and dynamics of pollinators are important in determining the net benefits to plants, and that fruit abortion can significantly affect these. We develop a model of mutualism between populations of plants and their pollinating seed-predators to explore the ecological consequences of fruit abortion on pollinator population dynamics and the net effect on plants. We demonstrate that the benefit to a plant population is unimodal as a function of pollinator abundance, relative to the abundance of flowers. Both selective abortion of fruit with eggs and random abortion of fruit, without reference to whether they have eggs or not, can limit pollinator population size. This can increase the net benefits to the plant population by limiting the number of eggs laid, if the pollination rate remains high. However, fruit abortion can possibly destabilize the pollinator population, with negative consequences for the plant population.

  17. Controls on dissolved organic matter (DOM) degradation in a headwater stream: the influence of photochemical and hydrological conditions in determining light-limitation or substrate-limitation of photo-degradation

    NASA Astrophysics Data System (ADS)

    Cory, R. M.; Harrold, K. H.; Neilson, B. T.; Kling, G. W.

    2015-07-01

    We investigated how absorption of sunlight by chromophoric dissolved organic matter (CDOM) controls the degradation and export of DOM from Imnavait Creek, a beaded stream in the Alaskan Arctic. We measured concentrations of dissolved organic carbon (DOC), as well as concentrations and characteristics of CDOM and fluorescent dissolved organic matter (FDOM), during ice-free periods of 2011-2012 in the pools of Imnavait Creek and in soil waters draining to the creek. Spatial and temporal patterns in CDOM and FDOM in Imnavait Creek were analyzed in conjunction with measures of DOM degradation by sunlight and bacteria and assessments of hydrologic residence times and in situ UV exposure. CDOM was the dominant light attenuating constituent in the UV and visible portion of the solar spectrum, with high attenuation coefficients ranging from 86 ± 12 m-1 at 305 nm to 3 ± 1 m-1 in the photosynthetically active region (PAR). High rates of light absorption and thus light attenuation by CDOM contributed to thermal stratification in the majority of pools in Imnavait Creek under low-flow conditions. In turn, thermal stratification increased the residence time of water and DOM, and resulted in a separation of water masses distinguished by contrasting UV exposure (i.e., UV attenuation by CDOM with depth resulted in bottom waters receiving less UV than surface waters). When the pools in Imnavait Creek were stratified, DOM in the pool bottom water closely resembled soil water DOM in character, while the concentration and character of DOM in surface water was reproduced by experimental photo-degradation of bottom water. These results, in combination with water column rates of DOM degradation by sunlight and bacteria, suggest that photo-degradation is the dominant process controlling DOM fate and export in Imnavait Creek. A conceptual model is presented showing how CDOM amount and lability interact with incident UV light and water residence time to determine whether photo-degradation is "light-limited" or "substrate-limited". We suggest that degradation, and thus export, of DOM in CDOM-rich streams or ponds similar to Imnavait is typically light-limited under most flow conditions.

  18. Controlled mutual quantum entity authentication using entanglement swapping

    NASA Astrophysics Data System (ADS)

    Min-Sung, Kang; Chang-Ho, Hong; Jino, Heo; Jong-In, Lim; Hyung-Jin, Yang

    2015-09-01

    In this paper, we suggest a controlled mutual quantum entity authentication protocol by which two users mutually certify each other on a quantum network using a sequence of Greenberger-Horne-Zeilinger (GHZ)-like states. Unlike existing unidirectional quantum entity authentication, our protocol enables mutual quantum entity authentication utilizing entanglement swapping; moreover, it allows the managing trusted center (TC) or trusted third party (TTP) to effectively control the certification of two users using the nature of the GHZ-like state. We will also analyze the security of the protocol and quantum channel. Project supported by the Research Foundation of Korea University.

  19. Spatial Mutual Information Based Hyperspectral Band Selection for Classification

    PubMed Central

    2015-01-01

    The amount of information involved in hyperspectral imaging is large. Hyperspectral band selection is a popular method for reducing dimensionality. Several information based measures such as mutual information have been proposed to reduce information redundancy among spectral bands. Unfortunately, mutual information does not take into account the spatial dependency between adjacent pixels in images thus reducing its robustness as a similarity measure. In this paper, we propose a new band selection method based on spatial mutual information. As validation criteria, a supervised classification method using support vector machine (SVM) is used. Experimental results of the classification of hyperspectral datasets show that the proposed method can achieve more accurate results. PMID:25918742

  20. Mutual Coupling and Compensation in FMCW MIMO Radar Systems

    NASA Astrophysics Data System (ADS)

    Schmid, Christian M.; Feger, Reinhard; Wagner, Christoph; Stelzer, Andreas

    2011-09-01

    This paper deals with mutual coupling, its effects and the compensation thereof in frequency-modulated continuous-wave (FMCW) multiple-input multiple-output (MIMO) array radar systems. Starting with a signal model we introduce mutual coupling and its primary sources in FMCW MIMO systems. We also give a worst-case boundary of the effects that mutual coupling can have on the side lobe level of an array. A method of dealing with and compensating for these effects is covered in this paper and verified by measurements from a 77-GHz FMCW radar system.

  1. A syndrome of mutualism reinforces the lifestyle of a sloth

    PubMed Central

    Pauli, Jonathan N.; Mendoza, Jorge E.; Steffan, Shawn A.; Carey, Cayelan C.; Weimer, Paul J.; Peery, M. Zachariah

    2014-01-01

    Arboreal herbivory is rare among mammals. The few species with this lifestyle possess unique adaptions to overcome size-related constraints on nutritional energetics. Sloths are folivores that spend most of their time resting or eating in the forest canopy. A three-toed sloth will, however, descend its tree weekly to defecate, which is risky, energetically costly and, until now, inexplicable. We hypothesized that this behaviour sustains an ecosystem in the fur of sloths, which confers cryptic nutritional benefits to sloths. We found that the more specialized three-toed sloths harboured more phoretic moths, greater concentrations of inorganic nitrogen and higher algal biomass than the generalist two-toed sloths. Moth density was positively related to inorganic nitrogen concentration and algal biomass in the fur. We discovered that sloths consumed algae from their fur, which was highly digestible and lipid-rich. By descending a tree to defecate, sloths transport moths to their oviposition sites in sloth dung, which facilitates moth colonization of sloth fur. Moths are portals for nutrients, increasing nitrogen levels in sloth fur, which fuels algal growth. Sloths consume these algae-gardens, presumably to augment their limited diet. These linked mutualisms between moths, sloths and algae appear to aid the sloth in overcoming a highly constrained lifestyle. PMID:24452028

  2. A syndrome of mutualism reinforces the lifestyle of a sloth.

    PubMed

    Pauli, Jonathan N; Mendoza, Jorge E; Steffan, Shawn A; Carey, Cayelan C; Weimer, Paul J; Peery, M Zachariah

    2014-03-01

    Arboreal herbivory is rare among mammals. The few species with this lifestyle possess unique adaptions to overcome size-related constraints on nutritional energetics. Sloths are folivores that spend most of their time resting or eating in the forest canopy. A three-toed sloth will, however, descend its tree weekly to defecate, which is risky, energetically costly and, until now, inexplicable. We hypothesized that this behaviour sustains an ecosystem in the fur of sloths, which confers cryptic nutritional benefits to sloths. We found that the more specialized three-toed sloths harboured more phoretic moths, greater concentrations of inorganic nitrogen and higher algal biomass than the generalist two-toed sloths. Moth density was positively related to inorganic nitrogen concentration and algal biomass in the fur. We discovered that sloths consumed algae from their fur, which was highly digestible and lipid-rich. By descending a tree to defecate, sloths transport moths to their oviposition sites in sloth dung, which facilitates moth colonization of sloth fur. Moths are portals for nutrients, increasing nitrogen levels in sloth fur, which fuels algal growth. Sloths consume these algae-gardens, presumably to augment their limited diet. These linked mutualisms between moths, sloths and algae appear to aid the sloth in overcoming a highly constrained lifestyle. PMID:24452028

  3. Intercontinental differences in resource use reveal the importance of mutualisms in fire ant invasions.

    PubMed

    Wilder, Shawn M; Holway, David A; Suarez, Andrew V; LeBrun, Edward G; Eubanks, Micky D

    2011-12-20

    Mutualisms play key roles in the functioning of ecosystems. However, reciprocally beneficial interactions that involve introduced species also can enhance invasion success and in doing so compromise ecosystem integrity. For example, the growth and competitive ability of introduced plant species can increase when fungal or microbial associates provide limiting nutrients. Mutualisms also may aid animal invasions, but how such systems may promote invasion success has received relatively little attention. Here we examine how access to food-for-protection mutualisms involving the red imported fire ant (Solenopsis invicta) aids the success of this prominent invader. Intense interspecific competition in its native Argentina constrained the ability of S. invicta to benefit from honeydew-producing Hemiptera (and other accessible sources of carbohydrates), whereas S. invicta dominated these resources in its introduced range in the United States. Consistent with this strong pattern, nitrogen isotopic data revealed that fire ants from populations in the United States occupy a lower trophic position than fire ants from Argentina. Laboratory and field experiments demonstrated that honeydew elevated colony growth, a crucial determinant of competitive performance, even when insect prey were not limiting. Carbohydrates, obtained largely through mutualistic partnerships with other organisms, thus represent critical resources that may aid the success of this widespread invasive species. These results illustrate the potential for mutualistic interactions to play a fundamental role in the establishment and spread of animal invasions. PMID:22143788

  4. A novel mutualism between an ant-plant and its resident pollinator

    NASA Astrophysics Data System (ADS)

    Shenoy, Megha; Borges, Renee M.

    2008-01-01

    Pollination systems in which the host plant provides breeding sites for pollinators, invariably within flowers, are usually highly specialized mutualisms. We found that the pollinating bee Braunsapis puangensis breeds within the caulinary domatia of the semi-myrmecophyte Humboldtia brunonis (Fabaceae), an unusual ant-plant that is polymorphic for the presence of domatia and harbours a diverse invertebrate fauna including protective and non-protective ants in its domatia. B. puangensis is the most common flower visitor that carries the highest proportion of H. brunonis pollen. This myrmecophyte is pollen limited and cross-pollinated by bees in the daytime. Hence, the symbiotic pollinator could provide a benefit to trees bearing domatia by alleviating this limitation. We therefore report for the first time an unspecialised mutualism in which a pollinator is housed in a plant structure other than flowers. Here, the cost to the plant is lower than for conventional brood-site pollination mutualisms where the pollinator develops at the expense of plant reproductive structures. Myrmecophytes housing resident pollinators are unusual, as ants are known to be enemies of pollinators, and housing them together may decrease the benefits that these residents could individually provide to the host plant.

  5. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.) ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self-help programs). 8.29 Section...

  6. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.) ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self-help programs). 8.29 Section...

  7. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.) ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self-help programs). 8.29 Section...

  8. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.) ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self-help programs). 8.29 Section...

  9. 24 CFR 8.29 - Homeownership programs (sections 235(i) and 235(j), Turnkey III and Indian housing mutual self...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... homebuyer, subject to maximum sales price limitations (see 24 CFR 235.320.) ... 235(i) and 235(j), Turnkey III and Indian housing mutual self-help programs). 8.29 Section 8.29... URBAN DEVELOPMENT Program Accessibility § 8.29 Homeownership programs (sections 235(i) and...

  10. Impact of sea-level rise on cross-shore sediment transport on fetch-limited barrier reef island beaches under modal and cyclonic conditions.

    PubMed

    Baldock, T E; Golshani, A; Atkinson, A; Shimamoto, T; Wu, S; Callaghan, D P; Mumby, P J

    2015-08-15

    A one-dimensional wave model is combined with an analytical sediment transport model to investigate the likely influence of sea-level rise on net cross-shore sediment transport on fetch-limited barrier reef and lagoon island beaches. The modelling considers if changes in the nearshore wave height and wave period in the lagoon induced by different water levels over the reef flat are likely to lead to net offshore or onshore movement of sediment. The results indicate that the effects of SLR on net sediment movement are highly variable and controlled by the bathymetry of the reef and lagoon. A significant range of reef-lagoon bathymetry, and notably shallow and narrow reefs, appears to lead hydrodynamic conditions and beaches that are likely to be stable or even accrete under SLR. Loss of reef structural complexity, particularly on the reef flat, increases the chance of sediment transport away from beaches and offshore. PMID:26093817

  11. Microwave-Assisted Superheating and/or Microwave-Specific Superboiling (Nucleation-Limited Boiling) of Liquids Occurs under Certain Conditions but is Mitigated by Stirring.

    PubMed

    Ferrari, Anthony; Hunt, Jacob; Stiegman, Albert; Dudley, Gregory B

    2015-01-01

    Temporary superheating and sustained nucleation-limited "superboiling" of unstirred liquids above the normal atmospheric boiling point have been documented during microwave heating. These phenomena are reliably observed under prescribed conditions, although the duration (of superheating) and magnitude (of superheating and superboiling) vary according to system parameters such as volume of the liquid and the size and shape of the vessel. Both phenomena are mitigated by rapid stirring with an appropriate stir bar and/or with the addition of boiling chips, which provide nucleation sites to support the phase-change from liquid to gas. With proper experimental design and especially proper stirring, the measured temperature of typical organic reaction mixtures heated at reflux will be close to the normal boiling point temperature of the solvent, whether heated using microwave radiation or conventional convective heat transfer. These observations are important to take into consideration when comparing reaction rates under conventional and microwave heating. PMID:26690096

  12. The Chemolithoautotroph Acidithiobacillus ferrooxidans Can Survive under Phosphate-Limiting Conditions by Expressing a C-P Lyase Operon That Allows It To Grow on Phosphonates? †

    PubMed Central

    Vera, Mario; Pagliai, Fernando; Guiliani, Nicolas; Jerez, Carlos A.

    2008-01-01

    The chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans is of great importance in biomining operations. During the bioleaching of ores, microorganisms are subjected to a variety of environmental stresses and to the limitations of some nutrients, such as inorganic phosphate (Pi), which is an essential component for all living cells. Although the primary source of phosphorus for microorganisms is Pi, some bacteria are also able to metabolize Pi esters (with a C-O-P bond) and phosphonates (with a very inert C-P bond). By using bioinformatic analysis of genomic sequences of the type strain of A. ferrooxidans (ATCC 23270), we found that as part of a Pho regulon, this bacterium has a complete gene cluster encoding C-P lyase, which is the main bacterial enzyme involved in phosphonate (Pn) degradation in other microorganisms. A. ferrooxidans was able to grow in the presence of methyl-Pn or ethyl-Pn as an alternative phosphorus source. Under these growth conditions, a great reduction in inorganic polyphosphate (polyP) levels was seen compared with the level for cells grown in the presence of Pi. By means of reverse transcription-PCR (RT-PCR), DNA macroarrays, and real-time RT-PCR experiments, it was found that A. ferrooxidans phn genes were cotranscribed and their expression was induced when the microorganism was grown in methyl-Pn as the only phosphorus source. This is the first report of phosphonate utilization in a chemolithoautotrophic microorganism. The existence of a functional C-P lyase system is a clear advantage for the survival under Pi limitation, a condition that may greatly affect the bioleaching of ores. PMID:18203861

  13. Parasponia: a novel system for studying mutualism stability.

    PubMed

    Behm, Jocelyn E; Geurts, Rene; Kiers, E Toby

    2014-12-01

    Understanding how mutualistic interactions are stabilized in the presence of cheaters is a major question in evolutionary biology. The legume-rhizobia mutualism has become a model system for studying how plants control cheating partners. However, the generality and evolutionary origins of these control mechanisms are intensely debated. In this Opinion article, we argue that a novel system--the Parasponia-rhizobia mutualism--will significantly advance research in mutualism stability. Parasponia is the only non-legume lineage to have evolved a rhizobial symbiosis, which provides an evolutionary replicate to test how rhizobial exploitation is controlled. Evidence also suggests that this symbiosis is young. This allows studies at an earlier evolutionary stage in mutualisms, so the origin of control mechanisms can be better understood. PMID:25239777

  14. Complex degree of mutual anisotropy of biological liquid crystals nets

    NASA Astrophysics Data System (ADS)

    Ushenko, Yuriy O.; Tomka, Yuriy Ya.; Misevitch, Igor Z.; Istratiy, Vadim V.; Telenga, Olga I.

    2011-03-01

    This paper is aimed to investigate the potentiality of describing and differentiating optical-anisotropic properties of biological liquid crystal net by statistic analysis of coordinate distributions of a new analytical parameter, a complex degree of mutual anisotropy.

  15. 1. PHOTOCOPY OF ASSOCIATED MUTUAL FIRE INSURANCE MAP 1906: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PHOTOCOPY OF ASSOCIATED MUTUAL FIRE INSURANCE MAP - 1906: ROGERS LOCOMOTIVE WORKS, PATERSON, N.J. (4x5 NEGATIVE) - Rogers Locomotive & Machine Works, Spruce & Market Streets, Paterson, Passaic County, NJ

  16. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  17. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  18. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  19. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  20. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  1. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  2. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  3. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  4. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  5. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  6. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  7. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  8. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  9. Functional Characterization of the Rice UDP-glucose 4-epimerase 1, OsUGE1: A Potential Role in Cell Wall Carbohydrate Partitioning during Limiting Nitrogen Conditions

    PubMed Central

    Guevara, David R.; El-Kereamy, Ashraf; Yaish, Mahmoud W.; Mei-Bi, Yong; Rothstein, Steven J.

    2014-01-01

    Plants grown under inadequate mineralized nitrogen (N) levels undergo N and carbon (C) metabolic re-programming which leads to significant changes in both soluble and insoluble carbohydrate profiles. However, relatively little information is available on the genetic factors controlling carbohydrate partitioning during adaptation to N-limitation conditions in plants. A gene encoding a uridine-diphospho-(UDP)-glucose 4-epimerase (OsUGE-1) from rice (Oryza sativa) was found to be N-responsive. We developed transgenic rice plants to constitutively over-express the OsUGE-1 gene (OsUGE1-OX1–2). The transgenic rice lines were similar in size to wild-type plants at the vegetative stage and at maturity regardless of the N-level tested. However, OsUGE1-OX lines maintained 18–24% more sucrose and 12–22% less cellulose in shoots compared to wild-type when subjected to sub-optimal N-levels. Interestingly, OsUGE1-OX lines maintained proportionally more galactose and glucose in the hemicellulosic polysaccharide profile of plants compared to wild-type plants when grown under low N. The altered cell wall C-partitioning during N-limitation in the OsUGE1-OX lines appears to be mediated by OsUGE1 via the repression of the cellulose synthesis associated genes, OsSus1, OsCesA4, 7, and 9. This relationship may implicate a novel control point for the deposition of UDP-glucose to the complex polysaccharide profiles of rice cell walls. However, a direct relationship between OsUGE1 and cell wall C-partitioning during N-limitation requires further investigation. PMID:24788752

  10. Mutual impedance of nonplanar-skew sinusoidal dipoles

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.; Geary, N. H.

    1974-01-01

    The mutual impedance of nonplanar-skew sinusoidal dipoles is presented as a summation of several exponential integrals with complex arguments. Mathematical models are developed to show the near-zone field of the sinusoidal dipole. The mutual impedance of coupled dipoles is expressed as the sum of four monopole-mobopole impedances to simplify the analysis procedure. The subroutines for solving the parameters of the dipoles are discussed.

  11. Quantum process reconstruction based on mutually unbiased basis

    SciTech Connect

    Fernandez-Perez, A.; Saavedra, C.; Klimov, A. B.

    2011-05-15

    We study a quantum process reconstruction based on the use of mutually unbiased projectors (MUB projectors) as input states for a D-dimensional quantum system, with D being a power of a prime number. This approach connects the results of quantum-state tomography using mutually unbiased bases with the coefficients of a quantum process, expanded in terms of MUB projectors. We also study the performance of the reconstruction scheme against random errors when measuring probabilities at the MUB projectors.

  12. Mutual impedance of nonplanar-skew sinusoidal dipoles

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.; Geary, N. H.

    1975-01-01

    The mutual impedance expressions for parallel dipoles in terms of sine-integrals and cosine-integrals have been published by King (1957). The investigation reported provides analogous expressions for nonparallel dipoles. The expressions presented are most useful when the monopoles are close together. The theory of moment methods shows an approach for employing the mutual impedance of filamentary sinusoidal dipoles to calculate the impedance and scattering properties of straight and bent wires with small but finite diameter.

  13. On the effects of assembly compression on the performance of liquid-feed DMFCs under methanol-limiting conditions: A 2D numerical study

    NASA Astrophysics Data System (ADS)

    García-Salaberri, P. A.; Vera, M.

    2015-07-01

    The influence of assembly compression on the performance of liquid-feed DMFCs under methanol-limiting conditions is explored by means of a 2D/1D multiphysics across-the-channel model. The numerical formulation incorporates a comprehensive 2D description of the anode GDL, including two-phase phenomena, non-uniform anisotropic transport properties, and electrical contact resistances at the GDL/BPP interface. GDL effective properties are evaluated using empirical data corresponding to Toray® carbon paper. A simplified but physically sound 1D description, locally coupled to the 2D anode GDL model, is adopted to describe transport processes in the MPLs, membrane and cathode GDL, whereas the catalyst layers are treated as infinitely thin surfaces. Good agreement is found between the numerical results and previous experimental data. The interplay between assembly compression, bipolar plate material, and channel configuration is also investigated. The results show that there is an optimum GDL compression ratio in terms of overall power density, the optimal compression level being strongly dependent on bipolar plate material. Beyond the optimum, the detrimental effect of compression is larger in non-parallel flow fields due to the additional reduction of methanol transported by under-rib convection. The results suggest that, under certain conditions, this transport mechanism could be more important than diffusion in the anode of liquid-feed DMFCs.

  14. Bacterial Growth Stimulation with Exogenous Siderophore and Synthetic N-Acyl Homoserine Lactone Autoinducers under Iron-Limited and Low-Nutrient Conditions

    PubMed Central

    Guan, Le Luo; Onuki, Hiroyuki; Kamino, Kei

    2000-01-01

    The growth of marine bacteria under iron-limited conditions was investigated. Neither siderophore production nor bacterial growth was detected for Pelagiobacter sp. strain V0110 when Fe(III) was present in the culture medium at a concentration of <1.0 ?M. However, the growth of V0110 was strongly stimulated by the presence of trace amounts of exogenous siderophore from an alpha proteobacterium, V0902, and 1 nM N-acyl-octanoylhomoserine lactone (C8-HSL), which is known as a quorum-sensing chemical signal. Even though the iron-binding functionality of a hydroxamate siderophore was undetected in the supernatant of V0902, a hydroxamate siderophore was detected in the supernatant of V0110 under the above conditions. These results indicated that hydroxamate siderophore biosynthesis by V0110 began in response to the exogenous siderophore from V0902 when in the presence of C8-HSL; however, C8-HSL production by V0110 and V0902 was not detected. Direct interaction between V0902 and V0110 through siderophore from V0902 was observed in the dialyzing culture. Similar stimulated growth by exogenous siderophore and HSL was also observed in other non-siderophore-producing bacteria isolated from marine sponges and seawater. The requirement of an exogenous siderophore and an HSL for heterologous siderophore production indicated the possibility that cell-cell communication between different species was occurring. PMID:10877770

  15. Intracellular aspartic proteinase Apr1p of Candida albicans is required for morphological transition under nitrogen-limited conditions but not for macrophage killing.

    PubMed

    Bauerová, Václava; Hájek, Miroslav; Pichová, Iva; Hrušková-Heidingsfeldová, Olga

    2014-11-01

    Vacuolar hydrolases have been thoroughly characterized in Saccharomyces cerevisiae, but their homologues in the fungal pathogen Candida albicans have received less attention. The genes APR1 and CPY1 of C. albicans encode putative vacuolar aspartic proteinase and serine carboxypeptidase, respectively. We examined properties of apr1? and cpy1? mutants, showing that Cpy1p molecular species detected in cell lysates of apr1? and its parental strain did not differ in molar mass. Processing of Cpy1p precursor is apparently independent of Apr1p. This is in contrast to S. cerevisiae, where vacuolar aspartic proteinase Pep4p is known to participate in the activation of other vacuolar hydrolases including serine carboxypeptidase. We also found that both apr1? and cpy1? strains are able to form hyphae in nutrient-rich filamentation media. However, proline as a sole nitrogen source induced filamentation only in cpy1? and its parental strain, but not in apr1?. This indicates the importance of Apr1p for the morphological transition under nitrogen-limited conditions. Despite that, the ability of apr1? to kill murine macrophages was not reduced under the conditions tested. PMID:24880249

  16. Effects of mutual shading on the regulation of photosynthesis in field-grown sorghum.

    PubMed

    Li, Tao; Liu, Li-Na; Jiang, Chuang-Dao; Liu, Yu-Jun; Shi, Lei

    2014-08-01

    In the field, close planting inevitably causes mutual shading and depression of leaf photosynthesis. To clarify the regulative mechanisms of photosynthesis under these conditions, the effects of planting density on leaf structure, gas exchange and proteomics were carefully studied in field-grown sorghum. In the absence of mineral deficiency, (1) close planting induced a significant decrease in light intensity within populations, which further resulted in much lower stomatal density and other anatomical characteristics associated with shaded leaves; (2) sorghum grown at high planting density had a lower net photosynthetic rate and stomatal conductance than those grown at low planting density; (3) approximately 62 protein spots changed their expression levels under the high planting density conditions, and 22 proteins associated with photosynthesis were identified by mass spectrometry. Further analysis revealed the depression of photosynthesis caused by mutual shading involves the regulation of leaf structure, absorption and transportation of CO2, photosynthetic electron transport, production of assimilatory power, and levels of enzymes related to the Calvin cycle. Additionally, heat shock protein and oxygen-evolving enhancer protein play important roles in photoprotection in field-grown sorghum. A model for the regulation of photosynthesis under mutual shading was suggested based on our results. PMID:24935099

  17. Oxford House and Alcoholics Anonymous: The Impact of Two Mutual-help Models on Abstinence

    PubMed Central

    Groh, David R.; Jason, Leonard A.; Ferrari, Joseph R.; Davis, Margaret I.

    2010-01-01

    Two examples of mutual-help approaches for substance abuse recovery are 12-step groups (AA and NA) and Oxford House. The present study examined the combined effects of AA and Oxford House residence on abstinence over a 24-month period with 150 individuals randomly assigned to either an Oxford House or to usual after-care. Among individuals with high 12-step involvement, the addition of Oxford House residence significantly increased the odds of abstinence (87.5% vs. 52.9%). However, among participants with low 12-step involvement, rates of abstinence were fairly similar across conditions (31.4% vs. 21.2%). Results suggested that the joint effectiveness of these mutual-help programs may promote abstinence. PMID:20689661

  18. A new structure of torque sensors using thin pickup head—Use of mutual coupling modulation

    NASA Astrophysics Data System (ADS)

    Sasada, I.; Koga, F.

    1994-05-01

    A new structure is proposed for the magnetoelastic torque sensors using a pair of figure-eight coils as a pickup. Mutual coupling between two figure-eight coils is used as a measure of torque applied to a shaft. The mutual coupling is governed by torque-induced anisotropic permeability at the surface of the shaft. Basic characteristics of the torque sensor are examined using a tempered steel shaft of 25 mm in diameter and a pair of 25-turn figure-eight coils. Sensitivity was 16 ?V/N m and hysteresis was 1.3% at the coil excitation condition of 60 kHz, 0.8 A (RMS). Exciting power needed to reduce hysteresis is much smaller with this structure than with previous methods using self-inductance as a measure of torque.

  19. Niche Engineering Demonstrates a Latent Capacity for Fungal-Algal Mutualism

    PubMed Central

    Hom, Erik F. Y.; Murray, Andrew W.

    2015-01-01

    Mutualistic symbioses shape the evolution of species and ecosystems and catalyze the emergence of biological complexity, yet how such symbioses first form is unclear. We show that an obligate mutualism between the yeast Saccharomyces cerevisiae and the alga Chlamydomonas reinhardtii—two model eukaryotes with very different life histories—can arise spontaneously in an environment requiring reciprocal carbon and nitrogen exchange. This capacity for mutualism is phylogenetically broad, extending to other Chlamydomonas and fungal species. Furthermore, we witnessed the spontaneous association of Chlamydomonas algal cells physically interacting with filamentous fungi. These observations demonstrate that under specific conditions, environmental change induces free-living species to become obligate mutualists and establishes a set of experimentally tractable, phylogenetically related, synthetic systems for studying the evolution of symbiosis. PMID:24994654

  20. A mechanistic molecular test of the plant-sanction hypothesis in legume-rhizobia mutualism

    NASA Astrophysics Data System (ADS)

    Marco, Diana E.; Pérez-Arnedo, Rebeca; Hidalgo-Perea, Ángeles; Olivares, José; Ruiz-Sainz, José E.; Sanjuán, Juan

    2009-09-01

    The origin and persistence of mutualism is difficult to explain because of the widespread occurrence of exploitative, 'cheating' partners. As a policing strategy stabilising intraspecific cooperation, host sanctions against non-N 2 fixing, cheating symbionts have been proposed to stabilise mutualism in legume-rhizobium symbiosis. Mechanism of penalisations would include decreased nodular rhizobial viability and/or early nodule senescence. We tested these potential mechanisms of penalisations in split-root experiments using two soybean varieties and two rhizobial strains, a cooperative, normal N 2-fixing strain and an isogenic non-fixing derivative. We found no differences in the number of viable rhizobia recovered from nodules and no differential expression of a nodular senescence molecular marker. Thus, our results do not support the hypothesis of plant sanctions acting against cheating rhizobia in our experimental conditions.

  1. The PHESAT95 catalogue of observations of the mutual events of the Saturnian satellites

    NASA Astrophysics Data System (ADS)

    Thuillot, W.; Arlot, J.-E.; Ruatti, C.; Berthier, J.; Blanco, C.; Colas, F.; Czech, W.; Damani, M.; D'Ambrosio, V.; Descamps, P.; Dourneau, G.; Emelianov, N.; Foglia, S.; Helmer, G.; Irsmambetova, T. R.; James, N.; Laques, P.; Lecacheux, J.; Le Campion, J.-F.; Ledoux, C.; Le Floch, J.-C.; Oprescu, G.; Rapaport, M.; Riccioli, R.; Starosta, B.; Tejfel, V. G.; Trunkovsky, E. M.; Viateau, B.; Veiga, C. H.; Vu, D. T.

    2001-05-01

    In 1994-1996 the Sun and the Earth passed through the equatorial plane of Saturn and therefore through the orbital planes of its main satellites. During this period, phenomena involving seven of these satellites were observed. Light curves of eclipses by Saturn and of mutual eclipses and occultations were recorded by the observers of the international campaign PHESAT95 organized by the Institut de mécanique céleste, Paris, France. Herein, we report 66 observations of 43 mutual events from 16 sites. For each observation, information is given about the telescope, the receptor, the site and the observational conditions. This paper gathers together all these data and gives a first estimate of the precision providing accurate astrometric data useful for the development of dynamical models.

  2. Effects of mutual shading of tree crowns on prediction of photosynthetic light-use efficiency in a coastal Douglas-fir forest.

    PubMed

    Hilker, Thomas; Coops, Nicholas C; Schwalm, Christopher R; Jassal, Rachhpal S; Black, T Andrew; Krishnan, Praveena

    2008-06-01

    Gross primary production (GPP) is often expressed as the product of absorbed photosynthetically active radiation and the efficiency (epsilon) with which a plant community uses absorbed radiation in biomass production. Light-use efficiency is affected by environmental stresses, and varies diurnally and seasonally. Uncertainty about epsilon can be a serious limitation when modeling GPP. An important determinant of epsilon is the amount and type of solar radiation incident on a canopy, because an abundance of light can trigger a photo-protective reaction, diminishing GPP. The radiation regime in a forest canopy is determined by the predominant sky conditions and by mutual shading of tree crowns. Shading effects, producing shifts in the amount of incident direct and diffuse solar radiation, have been largely ignored, however, because they depend on forest structure and are difficult to measure. We describe a new approach for estimating changes in mutual canopy shading throughout the day and year based on a canopy structure model derived from light detection and ranging (LiDAR). Proportions of canopy shading were then combined with eddy covariance data to assess the explanatory power for variance in epsilon by regression tree analysis over half-hourly, daily and weekly time scales. The approach explained between 75 and 97% of variance in epsilon, representing an increase of between 5 and 16% compared with models driven solely by meteorological variables. PMID:18381263

  3. Protein expression and transcription profiles of three strains of Aeromonas salmonicida ssp. salmonicida under normal and iron-limited culture conditions

    PubMed Central

    2014-01-01

    Background Aeromonas salmonicida is an important fish pathogen that produces a wide and varied array of virulence factors. Here we used iron deprivation by addition of the chelator 2’2-dipyridyl to induce the expression of several such virulence factors in three isolates of Aeromonas salmonicida (one avirulent and two virulent). By using SDS-PAGE followed by mass spectrometry, we identified proteins that appeared differentially expressed under these conditions. The differential transcription of the identified gene products were subsequently measured by reverse transcription quantitative real-time PCR (RT-qPCR). Results Our initial screening using SDS-PAGE identified five proteins that appeared differentially expressed in virulent and avirulent isolates or, within the same isolates, between bacteria cultivated under iron-rich or iron-deprived conditions. The transcription of the genes coding for these proteins were subsequently quantified by RT-qPCR. Results of this analysis demonstrated that the gene coding for alkyl hydroperoxide reductase (AhpC), a protein involved in oxidative stress response, was transcribed at a higher rate in the virulent strain as compared to the avirulent strain. Additionally, it was observed that addition of an iron chelator to the culture medium lead to a reduction of the transcription levels of the regulatory histone-like nucleoid structuring protein (H-NS). This was consistent in all three isolates. On the other hand, the transcription levels of the virulence array protein (VapA) and the protein ATP-synthetase F (ATPF) displayed only limited changes, despite being the dominant component of a protein fraction that displayed changes during the preliminary SDS-PAGE screening. This was true regardless of the culture conditions and of the isolates considered. Finally, transcription of the enzyme enolase was upregulated in the iron-deprived broths in all isolates. Conclusions We identified several genes differentially expressed under culture conditions known to lead to the overexpression of virulence factors. In addition, we identified alkyl hydroperoxide as being overexpressed in the virulent isolates compared to the avirulent isolates. The results from this study will contribute to enhance our understanding of the virulence of A. salmonicida and may suggest new directions for further research. PMID:24872729

  4. Copper-catalyzed intermolecular trifluoromethylarylation of alkenes: mutual activation of arylboronic acid and CF3+ reagent.

    PubMed

    Wang, Fei; Wang, Dinghai; Mu, Xin; Chen, Pinhong; Liu, Guosheng

    2014-07-23

    A novel copper-catalyzed intermolecular trifluoromethylarylation of alkenes is developed using less active ether-type Togni's reagent under mild reaction conditions. Various alkenes and diverse arylboronic acids are compatible with these conditions. Preliminary mechanistic studies reveal that a mutual activation process between arylboronic acid and CF3(+) reagent is essential. In addition, the reaction might involve a rate-determining transmetalation, and the final aryl C-C bond is derived from reductive elimination of the aryl(alkyl)Cu(III) intermediate. PMID:24983408

  5. Effects of Mutual Transits by Extrasolar Planet-Companion Systems on Light Curves

    NASA Astrophysics Data System (ADS)

    Sato, Masanao; Asada, Hideki

    2009-08-01

    We consider the effects of mutual transits by extrasolar planet-companion systems (in a true binary or a planet-satellite system) on light curves. We show that induced changes in light curves depend strongly on a ratio between a planet-companion's orbital velocity around their host star and a planet-companion's spin speed around their common center of mass. In both the slow and fast-spin cases (corresponding to long and short distances between them, respectively), a certain asymmetry appears in light curves. We show that, especially in the case of short distances, occultation of one faint object by the other, while the transit of the planet-companion system occurs in front of its parent star, causes an apparent increase in light curves, and characteristic fluctuations appear as important evidence of mutual transits. We show also that extrasolar mutual transits provide a complementary method for measuring the radii of two transiting objects, their separation and masses, and consequently for identifying the system as a true binary, a planet-satellite system, or others. Monitoring 105 stars for 3yr with Kepler may lead to the discovery of a second Earth-Moon-like system if the fraction of such systems for an averaged star is larger than 0.05, or we may put an upper limit on the fraction as f < 0.05.

  6. Mutual information in time-varying biochemical systems.

    PubMed

    Tostevin, Filipe; ten Wolde, Pieter Rein

    2010-06-01

    Cells must continuously sense and respond to time-varying environmental stimuli. These signals are transmitted and processed by biochemical signaling networks. However, the biochemical reactions making up these networks are intrinsically noisy, which limits the reliability of intracellular signaling. Here we use information theory to characterize the reliability of transmission of time-varying signals through elementary biochemical reactions in the presence of noise. We calculate the mutual information for both instantaneous measurements and trajectories of biochemical systems for a Gaussian model. Our results indicate that the same network can have radically different characteristics for the transmission of instantaneous signals and trajectories. For trajectories, the ability of a network to respond to changes in the input signal is determined by the timing of reaction events, and is independent of the correlation time of the output of the network. We also study how reliably signals on different time scales can be transmitted by considering the frequency-dependent coherence and gain-to-noise ratio. We find that a detector that does not consume the ligand molecule upon detection can more reliably transmit slowly varying signals, while an absorbing detector can more reliably transmit rapidly varying signals. Furthermore, we find that while one reaction may more reliably transmit information than another when considered in isolation, when placed within a signaling cascade the relative performance of the two reactions can be reversed. This means that optimizing signal transmission at a single level of a signaling cascade can reduce signaling performance for the cascade as a whole. PMID:20866450

  7. Automatic registration of multispectral images through maximization of mutual information

    NASA Astrophysics Data System (ADS)

    Guccione, Pietro; Mascolo, Luigi; Cifarelli, Giuseppe; Abbattista, Cristoforo; Tragni, Mario

    2014-10-01

    In this paper we propose a method to get fine registration of high resolution multispectral images. The algorithm supposes that a coarse registration, based on ancillary information, has been already performed. It is known, in fact, that residual distortions remain, due to the combined effects of Earth rotation and curvature, view geometry, sensor operation, variations in platform velocity, atmospheric and terrain effects. The algorithm grounds its main idea on the information-theoretic approach to register volumetric medical images of different modalities. Registration is achieved by adjustment of the relative position and orientation until the mutual information between the images is maximized. The idea is that the join information is maximized when the two images are at their best registration. This approach works directly with image data but in principle it can be applied in any transformed domain. While the original algorithm has been thought to make registration in a limited search space (i.e. translation and orientation), in the remote sensing framework the class of transformations is extended allowing scaling, shearing or a general polynomial model. The maximization of the target function is performed using both the stochastic gradient descent algorithm and the simulated annealing, since the former is known to occasionally deadlock in local maxima. We have applied the algorithm on a SPOT-5 couple of images, achieving the registration of chips of size 256x256 pixels at time. Accuracy has been obtained comparing the results with the outcomes of a commercial software that adopts a sort of Normalized Cross-Correlation method. On 143 chips taken throughout the image, the final translation accuracy resulted well below 1 pixel and the rotation accuracy about 0.015deg.

  8. Metabolic and transcriptomic response of the wine yeast Saccharomyces cerevisiae strain EC1118 after an oxygen impulse under carbon-sufficient, nitrogen-limited fermentative conditions.

    PubMed

    Orellana, Marcelo; Aceituno, Felipe F; Slater, Alex W; Almonacid, Leonardo I; Melo, Francisco; Agosin, Eduardo

    2014-05-01

    During alcoholic fermentation, Saccharomyces cerevisiae is exposed to continuously changing environmental conditions, such as decreasing sugar and increasing ethanol concentrations. Oxygen, a critical nutrient to avoid stuck and sluggish fermentations, is only discretely available throughout the process after pump-over operation. In this work, we studied the physiological response of the wine yeast S. cerevisiae strain EC1118 to a sudden increase in dissolved oxygen, simulating pump-over operation. With this aim, an impulse of dissolved oxygen was added to carbon-sufficient, nitrogen-limited anaerobic continuous cultures. Results showed that genes related to mitochondrial respiration, ergosterol biosynthesis, and oxidative stress, among other metabolic pathways, were induced after the oxygen impulse. On the other hand, mannoprotein coding genes were repressed. The changes in the expression of these genes are coordinated responses that share common elements at the level of transcriptional regulation. Beneficial and detrimental effects of these physiological processes on wine quality highlight the dual role of oxygen in 'making or breaking wines'. These findings will facilitate the development of oxygen addition strategies to optimize yeast performance in industrial fermentations. PMID:24387769

  9. Quantitative proteomic view on secreted, cell surface-associated, and cytoplasmic proteins of the methicillin-resistant human pathogen Staphylococcus aureus under iron-limited conditions.

    PubMed

    Hempel, Kristina; Herbst, Florian-Alexander; Moche, Martin; Hecker, Michael; Becher, Dörte

    2011-04-01

    Staphylococcus aureus is capable of colonizing and infecting humans by its arsenal of surface-exposed and secreted proteins. Iron-limited conditions in mammalian body fluids serve as a major environmental signal to bacteria to express virulence determinants. Here we present a comprehensive, gel-free, and GeLC-MS/MS-based quantitative proteome profiling of S. aureus under this infection-relevant situation. (14)N(15)N metabolic labeling and three complementing approaches were combined for relative quantitative analyses of surface-associated proteins. The surface-exposed and secreted proteome profiling approaches comprise trypsin shaving, biotinylation, and precipitation of the supernatant. By analysis of the outer subproteomic and cytoplasmic protein fraction, 1210 proteins could be identified including 221 surface-associated proteins. Thus, access was enabled to 70% of the predicted cell wall-associated proteins, 80% of the predicted sortase substrates, two/thirds of lipoproteins and more than 50% of secreted and cytoplasmic proteins. For iron-deficiency, 158 surface-associated proteins were quantified. Twenty-nine proteins were found in altered amounts showing particularly surface-exposed proteins strongly induced, such as the iron-regulated surface determinant proteins IsdA, IsdB, IsdC and IsdD as well as lipid-anchored iron compound-binding proteins. The work presents a crucial subject for understanding S. aureus pathophysiology by the use of methods that allow quantitative surface proteome profiling. PMID:21323324

  10. Initial Piloted Simulation Evaluation of the Reference-H High-Speed Civil Transport Design During Takeoff and Recovery From Limit Flight Conditions

    NASA Technical Reports Server (NTRS)

    Glaab, Louis J.

    1999-01-01

    An initial assessment of a proposed High-Speed Civil Transport (HSCT) was conducted in the fall of 1995 at the NASA Langley Research Center. This configuration, known as the Industry Reference-H (Ref.-H), was designed by the Boeing Aircraft Company as part of their work in the High Speed Research program. It included a conventional tail, a cranked-arrow wing, four mixed-flow turbofan engines, and capacity for transporting approximately 300 passengers. The purpose of this assessment was to evaluate and quantify operational aspects of the Reference-H configuration from a pilot's perspective with the additional goal of identifying design strengths as well as any potential configuration deficiencies. This study was aimed at evaluating the Ref.-H configuration at many points of the aircraft's envelope to determine the suitability of the vehicle to accomplish typical mission profiles as well as emergency or envelope-limit conditions. Pilot-provided Cooper-Harper ratings and comments constituted the primary vehicle evaluation metric. The analysis included simulated real-time piloted evaluations, performed in a 6 degree of freedom motion base NASA Langley Visual-Motion Simulator, combined with extensive bath analysis. The assessment was performed using the third major release of the simulation data base (known as Ref.-H cycle 2B).

  11. 'Why does it happen like this?' Consulting with users and providers prior to an evaluation of services for children with life limiting conditions and their families.

    PubMed

    Hunt, Anne; Brown, Erica; Coad, Jane; Staniszewska, Sophie; Hacking, Suzanne; Chesworth, Brigit; Chambers, Lizzie

    2015-09-01

    Children with life limiting conditions and their families have complex needs. Evaluations must consider their views and perspectives to ensure care is relevant, appropriate and acceptable. We consulted with children, young people, their parents and local professionals to gain a more informed picture of issues affecting them prior to preparing a bid to evaluate services in the area. Multiple methods included focus groups, face-to-face and telephone interviews and participatory activities. Recordings and products from activities were analysed for content to identify areas of relevance and concern. An overarching theme from parents was 'Why does it happen like this?' Services did not seem designed to meet their needs. Whilst children and young people expressed ideas related to quality of environment, services and social life, professionals focused on ways of meeting the families' needs. The theme that linked families' concerns with those of professionals was 'assessing individual needs'. Two questions to be addressed by the evaluation are (1) to what extent are services designed to meet the needs of children and families and (2) to what extent are children, young people and their families consulted about what they need? Consultations with families and service providers encouraged us to continue their involvement as partners in the evaluation. PMID:24270996

  12. Mutualism Disruption Threatens Global Plant Biodiversity: A Systematic Review

    PubMed Central

    Aslan, Clare E.; Zavaleta, Erika S.; Tershy, Bernie; Croll, Donald

    2013-01-01

    Background As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create “widow” species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However, the scope of this problem – the magnitude of biodiversity that may lose mutualist partners and the consequences of these losses – remains unknown. Methodology/Principal Findings We conducted a systematic review and synthesis of data from a broad range of sources to estimate the threat posed by vertebrate extinctions to the global biodiversity of vertebrate-dispersed and -pollinated plants. Though enormous research gaps persist, our analysis identified Africa, Asia, the Caribbean, and global oceanic islands as geographic regions at particular risk of disruption of these mutualisms; within these regions, percentages of plant species likely affected range from 2.1–4.5%. Widowed plants are likely to experience reproductive declines of 40–58%, potentially threatening their persistence in the context of other global change stresses. Conclusions Our systematic approach demonstrates that thousands of species may be impacted by disruption in one class of mutualisms, but extinctions will likely disrupt other mutualisms, as well. Although uncertainty is high, there is evidence that mutualism disruption directly threatens significant biodiversity in some geographic regions. Conservation measures with explicit focus on mutualistic functions could be necessary to bolster populations of widowed species and maintain ecosystem functions. PMID:23840571

  13. 12 CFR Appendix C to Part 239 - Mutual Holding Company Model Bylaws

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Mutual Holding Company Model Bylaws C Appendix...—Mutual Holding Company Model Bylaws MODEL BYLAWS FOR MUTUAL HOLDING COMPANIES The term “trustees” may be... mutual holding company for the election of directors and for the transaction of any other business of...

  14. 12 CFR Appendix C to Part 239 - Mutual Holding Company Model Bylaws

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Mutual Holding Company Model Bylaws C Appendix...—Mutual Holding Company Model Bylaws MODEL BYLAWS FOR MUTUAL HOLDING COMPANIES The term “trustees” may be... mutual holding company for the election of directors and for the transaction of any other business of...

  15. 12 CFR Appendix C to Part 239 - Mutual Holding Company Model Bylaws

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Mutual Holding Company Model Bylaws C Appendix...—Mutual Holding Company Model Bylaws MODEL BYLAWS FOR MUTUAL HOLDING COMPANIES The term “trustees” may be... mutual holding company for the election of directors and for the transaction of any other business of...

  16. 77 FR 73700 - Mutual of America Life Insurance Company, et al;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... COMMISSION Mutual of America Life Insurance Company, et al; Notice of Application December 5, 2012. AGENCY... the Act from Section 17(a) of the Act. APPLICANTS: Mutual of America Life Insurance Company (``Mutual of America''), Wilton Reassurance Life Company of New York (``Wilton,'' and, together with Mutual...

  17. Mutual Information for the Detection of Crush

    PubMed Central

    Harding, Peter; Gwynne, Steve; Amos, Martyn

    2011-01-01

    Fatal crush conditions occur in crowds with tragic frequency. Event organizers and architects are often criticised for failing to consider the causes and implications of crush, but the reality is that both the prediction and prevention of such conditions offer a significant technical challenge. Full treatment of physical force within crowd simulations is precise but often computationally expensive; the more common method of human interpretation of results is computationally “cheap” but subjective and time-consuming. This paper describes an alternative method for the analysis of crowd behaviour, which uses information theory to measure crowd disorder. We show how this technique may be easily incorporated into an existing simulation framework, and validate it against an historical event. Our results show that this method offers an effective and efficient route towards automatic detection of the onset of crush. PMID:22229055

  18. Sets of Mutually Orthogonal Sudoku Latin Squares

    ERIC Educational Resources Information Center

    Vis, Timothy; Petersen, Ryan M.

    2009-01-01

    A Latin square of order "n" is an "n" x "n" array using n symbols, such that each symbol appears exactly once in each row and column. A set of Latin squares is c ordered pairs of symbols appearing in the cells of the array are distinct. The popular puzzle Sudoku involves Latin squares with n = 9, along with the added condition that each of the 9…

  19. Occurrence and characteristics of mutual interference between LIDAR scanners

    NASA Astrophysics Data System (ADS)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  20. Sparse Bayesian Learning for DOA Estimation with Mutual Coupling

    PubMed Central

    Dai, Jisheng; Hu, Nan; Xu, Weichao; Chang, Chunqi

    2015-01-01

    Sparse Bayesian learning (SBL) has given renewed interest to the problem of direction-of-arrival (DOA) estimation. It is generally assumed that the measurement matrix in SBL is precisely known. Unfortunately, this assumption may be invalid in practice due to the imperfect manifold caused by unknown or misspecified mutual coupling. This paper describes a modified SBL method for joint estimation of DOAs and mutual coupling coefficients with uniform linear arrays (ULAs). Unlike the existing method that only uses stationary priors, our new approach utilizes a hierarchical form of the Student t prior to enforce the sparsity of the unknown signal more heavily. We also provide a distinct Bayesian inference for the expectation-maximization (EM) algorithm, which can update the mutual coupling coefficients more efficiently. Another difference is that our method uses an additional singular value decomposition (SVD) to reduce the computational complexity of the signal reconstruction process and the sensitivity to the measurement noise. PMID:26501284

  1. Comprehensive analysis of mutually exclusive alternative splicing in C. elegans

    PubMed Central

    Kuroyanagi, Hidehito; Takei, Satomi; Suzuki, Yutaka

    2014-01-01

    Mutually exclusive selection of one exon in a cluster of exons is a rare form of alternative pre-mRNA splicing, yet suggests strict regulation. However, the repertoires of regulation mechanisms for the mutually exclusive (ME) splicing in vivo are still unknown. Here, we experimentally explore putative ME exons in C. elegans to demonstrate that 29 ME exon clusters in 27 genes are actually selected in a mutually exclusive manner. Twenty-two of the clusters consist of homologous ME exons. Five clusters have too short intervening introns to be excised between the ME exons. Fidelity of ME splicing relies at least in part on nonsense-mediated mRNA decay for 14 clusters. These results thus characterize all the repertoires of ME splicing in this organism. PMID:25254147

  2. Measuring causality by taking the directional symbolic mutual information approach

    NASA Astrophysics Data System (ADS)

    Chen, Gui; Xie, Lei; Chu, Jian

    2013-03-01

    We propose a novel measure to assess causality through the comparison of symbolic mutual information between the future of one random quantity and the past of the other. This provides a new perspective that is different from the conventional conceptions. Based on this point of view, a new causality index is derived that uses the definition of directional symbolic mutual information. This measure presents properties that are different from the time delayed mutual information since the symbolization captures the dynamic features of the analyzed time series. In addition to characterizing the direction and the amplitude of the information flow, it can also detect coupling delays. This method has the property of robustness, conceptual simplicity, and fast computational speed.

  3. Sparse Bayesian learning for DOA estimation with mutual coupling.

    PubMed

    Dai, Jisheng; Hu, Nan; Xu, Weichao; Chang, Chunqi

    2015-01-01

    Sparse Bayesian learning (SBL) has given renewed interest to the problem of direction-of-arrival (DOA) estimation. It is generally assumed that the measurement matrix in SBL is precisely known. Unfortunately, this assumption may be invalid in practice due to the imperfect manifold caused by unknown or misspecified mutual coupling. This paper describes a modified SBL method for joint estimation of DOAs and mutual coupling coefficients with uniform linear arrays (ULAs). Unlike the existing method that only uses stationary priors, our new approach utilizes a hierarchical form of the Student t prior to enforce the sparsity of the unknown signal more heavily. We also provide a distinct Bayesian inference for the expectation-maximization (EM) algorithm, which can update the mutual coupling coefficients more efficiently. Another difference is that our method uses an additional singular value decomposition (SVD) to reduce the computational complexity of the signal reconstruction process and the sensitivity to the measurement noise. PMID:26501284

  4. Empirical study of the tails of mutual fund size.

    PubMed

    Schwarzkopf, Yonathan; Farmer, J Doyne

    2010-06-01

    The mutual fund industry manages about a quarter of the assets in the U.S. stock market and thus plays an important role in the U.S. economy. The question of how much control is concentrated in the hands of the largest players is best quantitatively discussed in terms of the tail behavior of the mutual fund size distribution. We study the distribution empirically and show that the tail is much better described by a log-normal than a power law, indicating less concentration than, for example, personal income. The results are highly statistically significant and are consistent across fifteen years. This contradicts a recent theory concerning the origin of the power law tails of the trading volume distribution. Based on the analysis in a companion paper, the log-normality is to be expected, and indicates that the distribution of mutual funds remains perpetually out of equilibrium. PMID:20866484

  5. Mutual information after a local quench in conformal field theory

    NASA Astrophysics Data System (ADS)

    Asplund, Curtis T.; Bernamonti, Alice

    2014-03-01

    We compute the entanglement entropy and mutual information for two disjoint intervals in two-dimensional conformal field theories as a function of time after a local quench, using the replica trick and boundary conformal field theory. We obtain explicit formulas for the universal contributions, which are leading in the regimes of, for example, close or well-separated intervals of fixed length. The results are largely consistent with the quasiparticle picture, in which entanglement above that present in the ground state is carried by pairs of entangled freely propagating excitations. We also calculate the mutual information for two disjoint intervals in a proposed holographic local quench, whose holographic energy-momentum tensor matches the conformal field theory one. We find that the holographic mutual information shows qualitative differences from the conformal field theory results and we discuss possible interpretations of this.

  6. Algorithmic significance, mutual information, and DNA sequence comparisons

    SciTech Connect

    Milosavljevic, A.

    1993-12-31

    The newly proposed algorithmic significance method [6] enables recognition of patterns in DNA sequences at prespecified significance levels via minimal length encoding. We extend the method to provide a formal framework for DNA sequence comparisons via mutual information. While in this paper we restrict our discussion to DNA sequence analysis, the methods that are presented are potentially applicable in many other domains. Under a few simplifying assumptions, we show that significance of sequence similarity depends exponentially on mutual information. In addition to this estimate of significance, the concept of mutual information provides solutions to the following two problems in DNA sequence comparisons: Factoring out contribution of shared repetitive patterns and factoring out bias due to partial sequencing.

  7. Empirical study of the tails of mutual fund size

    NASA Astrophysics Data System (ADS)

    Schwarzkopf, Yonathan; Farmer, J. Doyne

    2010-06-01

    The mutual fund industry manages about a quarter of the assets in the U.S. stock market and thus plays an important role in the U.S. economy. The question of how much control is concentrated in the hands of the largest players is best quantitatively discussed in terms of the tail behavior of the mutual fund size distribution. We study the distribution empirically and show that the tail is much better described by a log-normal than a power law, indicating less concentration than, for example, personal income. The results are highly statistically significant and are consistent across fifteen years. This contradicts a recent theory concerning the origin of the power law tails of the trading volume distribution. Based on the analysis in a companion paper, the log-normality is to be expected, and indicates that the distribution of mutual funds remains perpetually out of equilibrium.

  8. Strain localization in brittle-ductile shear zones: fluid-abundant vs. fluid-limited conditions (an example from Wyangala area, Australia)

    NASA Astrophysics Data System (ADS)

    Spruzeniece, L.; Piazolo, S.

    2015-07-01

    This study focuses on physiochemical processes occurring in a brittle-ductile shear zone at both fluid-present and fluid-limited conditions. In the studied shear zone (Wyangala, SE Australia), a coarse-grained two-feldspar-quartz-biotite granite is transformed into a medium-grained orthogneiss at the shear zone margins and a fine-grained quartz-muscovite phyllonite in the central parts. The orthogneiss displays cataclasis of feldspar and crystal-plastic deformation of quartz. Quartz accommodates most of the deformation and is extensively recrystallized, showing distinct crystallographic preferred orientation (CPO). Feldspar-to-muscovite, biotite-to-muscovite and albitization reactions occur locally at porphyroclasts' fracture surfaces and margins. However, the bulk rock composition shows very little change in respect to the wall rock composition. In contrast, in the shear zone centre quartz occurs as large, weakly deformed porphyroclasts in sizes similar to that in the wall rock, suggesting that it has undergone little deformation. Feldspars and biotite are almost completely reacted to muscovite, which is arranged in a fine-grained interconnected matrix. Muscovite-rich layers contain significant amounts of fine-grained intermixed quartz with random CPO. These domains are interpreted to have accommodated most of the strain. Bulk rock chemistry data show a significant increase in SiO2 and depletion in NaO content compared to the wall rock composition. We suggest that the high- and low-strain microstructures in the shear zone represent markedly different scenarios and cannot be interpreted as a simple sequential development with respect to strain. Instead, we propose that the microstructural and mineralogical changes in the shear zone centre arise from a local metasomatic alteration around a brittle precursor. When the weaker fine-grained microstructure is established, the further flow is controlled by transient porosity created at (i) grain boundaries in fine-grained areas deforming by grain boundary sliding (GBS) and (ii) transient dilatancy sites at porphyroclast-matrix boundaries. Here a growth of secondary quartz occurs from incoming fluid, resulting in significant changes in bulk composition and eventually rheological hardening due to the precipitation-related increase in the mode and grain size of quartz. In contrast, within the shear zone margins the amount of fluid influx and associated reactions is limited; here deformation mainly proceeds by dynamic recrystallization of the igneous quartz grains. The studied shear zone exemplifies the role of syn-deformational fluids and fluid-induced reactions on the dominance of deformation processes and subsequent contrasting rheological behaviour at micron to metre scale.

  9. Increased belowground C release during initial plant development of Populus deltoides x nigra grown under light and C reserve limited conditions

    NASA Astrophysics Data System (ADS)

    Studer, Mirjam S.; Siegwolf, Rolf T. W.; Schmidt, Michael W. I.; Abiven, Samuel

    2014-05-01

    Plants might be a key factor for the long-term stabilisation of carbon (C) in the soil, e.g. through enhanced physical protection of root-derived C against microbial decomposition in soil aggregates. On the other hand C released by the plants into the soil might promote the decomposition of native soil organic matter (SOM) through the stimulation of microbial activity. We measured the C budget of developing plant-soil systems (Populus deltoides x nigra, Cambisol soil) in the laboratory under controlled environmental conditions. In order to distinguish plant-derived from native C in the SOM and the soil CO2 efflux, we labelled the poplar shoots continuously with 13C-CO2 from first emergence of leaves (sprouting from stem cuttings). Throughout the experiment the CO2 fluxes (photosynthetic assimilation, dark respiratory loss, soil CO2 efflux) were measured frequently (every 30 min) and the 13C was traced in the soil CO2 efflux (1-2 times a week). After 10 weeks the plant-soil systems were destructively harvested and the distribution of the 13C distribution was analysed. The plants developed slowly (compared to previous experiments), most likely due to limitation in C reserves (long term cutting storage) and C supply (low light intensities). The amount of 13C recovered in the roots, microbial biomass and soil CO2 efflux was directly correlated with the leaf area of the different plant individuals. After 3-4 weeks of plant development we observed a high peak in the total soil CO2 efflux. During this time the relative belowground C release was increased massively over the basal rate of 17 % of net C assimilated, whereby the variability between the plant individuals was large. The smallest plants, i.e. the plants that were most resource limited, obtained the highest belowground C release accounting at the peak time for up to 57 % of net assimilated C. We hypothesize that the plants released specific compounds, which either directly (enzymatically) or indirectly (priming) enhanced the decomposition of native SOM as a survival mechanisms (e.g. mine for nutrients). The results of this study confirm linear correlations between aboveground plant traits (leaf area) and belowground C allocation into roots, microbial biomass and plant-derived respiration. However it also highlights that plant-soil systems are not permanently in a steady state. C allocation patterns can change massively when the plant is under stress, which affects other fluxes within the terrestrial C cycle, such as the microbial decomposition of SOM.

  10. A New NOAO Survey Program: Mutual Orbits and Masses of Kuiper Belt Binaries

    NASA Astrophysics Data System (ADS)

    Grundy, W. M.; Benecchi, S. D.; Buie, M. W.; Noll, K. S.; Porter, S. B.; Roe, H. G.; Stansberry, J. A.; Trujillo, C. A.

    2011-10-01

    We will report progress from our multi-year campaign to determine the orbits and masses of transneptunian binaries (TNBs). Binary systems are abundant in the Kuiper belt, and especially among the "Cold Classical" disk of objects on low-eccentricity, lowinclination, non-resonant orbits about the Sun [1]. These binaries offer an opportunity to learn the masses and densities of an intriguing population of small, distant objects. Additionally, the statistics of their mutual orbital parameters offer clues to conditions where they formed in the protoplanetary nebula, as well as to subsequent dynamical evolution of the outer solar system. Historically, NASA/ESA's Hubble Space Telescope (HST) has been the premier facility for spatially resolving the components of TNBs, benefiting from its exceptionally stable optics and from diffraction- limited imaging unimpeded by the Earth's atmosphere. More recently, laser guide star adaptive optics (LGS AO) technology has enabled large groundbased telescopes to begin contributing valuable data as well [2]. LGS AO observations of faint TNBs (the components of which have typical V magnitudes ~24th) are only feasible when the target passes near an appulse star suitable for use as a tip-tilt correction reference. We have been using LGS AO data from Keck in combination with HST data to constrain TNB orbits [e.g., 3]. In 2011 we began a new 3-year NOAO Survey program to use LGS AO on the 8 m Gemini North telescope. We will discuss how Gemini and other telescopes complement one another, show examples of data from Gemini, Keck, and HST, and describe how we are using these facilities to improve orbital knowledge for as many of the tighter TNBs as we can. Optimal scheduling techniques enable us to make the most efficient possible use of the very limited availability of time on telescopes capable of resolving these objects [4]. Our progress is documented online at http://www.lowell.edu/~grundy/tnbs. We will discuss systems of particular interest such as those likely to undergo mutual events in the near future. These include 2003 QW111 (events probably beginning in a few years) and 79360 1997 CS29 (events probably happening right now). Also of interest are systems for which sizes can be independently determined from thermal or other observations. For these systems, the dynamical masses from binary orbits enable computation of bulk densities. We will also explore statistical patterns beginning to emerge from the growing ensemble of known TNB orbits. Observed distributions of orbital characteristics, including inclinations, eccentricities, and separations have important implications for formation scenarios as well as subsequent evolution [5], although accounting for observational biases remains an open issue. For instance, there appears to be a shortage of loose binaries among TNOs on excited heliocentric orbits. While there seems to be an excess of prograde systems among the tighter binaries, there is little evidence for preferentially low inclinations.

  11. Separability criteria via sets of mutually unbiased measurements.

    PubMed

    Liu, Lu; Gao, Ting; Yan, Fengli

    2015-01-01

    Mutually unbiased measurements (MUMs) are generalized from the concept of mutually unbiased bases (MUBs) and include the complete set of MUBs as a special case, but they are superior to MUBs as they do not need to be rank one projectors. We investigate entanglement detection using sets of MUMs and derive separability criteria for multipartite qudit systems, arbitrary high-dimensional bipartite systems of a d1-dimensional subsystem and a d2-dimensional subsystem, and multipartite systems of multi-level subsystems. These criteria are of the advantages of more effective and wider application range than previous criteria. They provide experimental implementation in detecting entanglement of unknown quantum states. PMID:26278628

  12. Computer modelling of electronegative plasma sheaths and their mutual interaction

    NASA Astrophysics Data System (ADS)

    Hromadka, Jakub; Ibehej, Tomas; Hrach, Rudolf

    2015-10-01

    Our paper focuses on investigation of sheath structures formed in the vicinity of biased solid objects immersed in electronegative plasma. In Particular, phenomena during mutual interaction of several plasma sheaths were investigated. Our results show the manner in which the sheath of a cylindrical probe is affected by the presence of another cylindrical probe with smaller radius in its surroundings. Number density of charged particles, electric field intensity and fluxes of charged particles on the probes were observed to quantify the mutual interaction of sheaths. The study was done by means of the 2D particle-in-cell model with Monte Carlo treatment of collisions.

  13. Separability criteria via sets of mutually unbiased measurements

    PubMed Central

    Liu, Lu; Gao, Ting; Yan, Fengli

    2015-01-01

    Mutually unbiased measurements (MUMs) are generalized from the concept of mutually unbiased bases (MUBs) and include the complete set of MUBs as a special case, but they are superior to MUBs as they do not need to be rank one projectors. We investigate entanglement detection using sets of MUMs and derive separability criteria for multipartite qudit systems, arbitrary high-dimensional bipartite systems of a d1-dimensional subsystem and a d2-dimensional subsystem, and multipartite systems of multi-level subsystems. These criteria are of the advantages of more effective and wider application range than previous criteria. They provide experimental implementation in detecting entanglement of unknown quantum states. PMID:26278628

  14. The ZmASR1 Protein Influences Branched-Chain Amino Acid Biosynthesis and Maintains Kernel Yield in Maize under Water-Limited Conditions1[W][OA

    PubMed Central

    Virlouvet, Laetitia; Jacquemot, Marie-Pierre; Gerentes, Denise; Corti, Hélène; Bouton, Sophie; Gilard, Françoise; Valot, Benoît; Trouverie, Jacques; Tcherkez, Guillaume; Falque, Matthieu; Damerval, Catherine; Rogowsky, Peter; Perez, Pascual; Noctor, Graham; Zivy, Michel; Coursol, Sylvie

    2011-01-01

    Abscisic acid-, stress-, and ripening-induced (ASR) proteins were first described about 15 years ago as accumulating to high levels during plant developmental processes and in response to diverse stresses. Currently, the effects of ASRs on water deficit tolerance and the ways in which their physiological and biochemical functions lead to this stress tolerance remain poorly understood. Here, we characterized the ASR gene family from maize (Zea mays), which contains nine paralogous genes, and showed that maize ASR1 (ZmASR1) was encoded by one of the most highly expressed paralogs. Ectopic expression of ZmASR1 had a large overall impact on maize yield that was maintained under water-limited stress conditions in the field. Comparative transcriptomic and proteomic analyses of wild-type and ZmASR1-overexpressing leaves led to the identification of three transcripts and 16 proteins up- or down-regulated by ZmASR1. The majority of them were involved in primary and/or cellular metabolic processes, including branched-chain amino acid (BCAA) biosynthesis. Metabolomic and transcript analyses further indicated that ZmASR1-overexpressing plants showed a decrease in BCAA compounds and changes in BCAA-related gene expression in comparison with wild-type plants. Interestingly, within-group correlation matrix analysis revealed a close link between 13 decreased metabolites in ZmASR1-overexpressing leaves, including two BCAAs. Among these 13 metabolites, six were previously shown to be negatively correlated to biomass, suggesting that ZmASR1-dependent regulation of these 13 metabolites might contribute to regulate leaf growth, resulting in improvement in kernel yield. PMID:21852416

  15. The contribution of self-help/mutual aid groups to mental well-being.

    PubMed

    Seebohm, Patience; Chaudhary, Sarah; Boyce, Melanie; Elkan, Ruth; Avis, Mark; Munn-Giddings, Carol

    2013-07-01

    This article explores the contribution of self-help/mutual aid groups to mental well-being. Self-help/mutual aid groups are self-organising groups where people come together to address a shared a health or social issue through mutual support. They are associated with a range of health and social benefits, but remain poorly understood. This article draws on data from stage one of ESTEEM, a project which runs from 2010 to 2013. Stage one ran from 2010 to 2011 and involved participatory, qualitative research carried out in two UK sites. Twenty-one groups were purposively selected to include a range of focal issues, longevity, structures and ethnic backgrounds. Researchers carried out 21 interviews with group coordinators and twenty group discussions with members to explore the groups' purpose, nature and development. Preliminary analysis of the data suggested that mental well-being was a common theme across the groups. Subsequently the data were re-analysed to explore the groups' contribution to mental well-being using a checklist of protective factors for mental well-being as a coding framework. The findings showed that groups made a strong contribution to members' mental well-being by enhancing a sense of control, increasing resilience and facilitating participation. Group members were uplifted by exchanging emotional and practical support; they gained self-esteem, knowledge and confidence, thereby increasing their control over their situation. For some groups, socio-economic factors limited their scope and threatened their future. The article provides an evidence-base which illustrates how self-help/mutual aid groups can enhance mental well-being. If supported within a strategy for social justice, these groups enable people with varied concerns to develop a tailored response to their specific needs. The authors suggest that policy-makers engage with local people, investing in support proportionate to the needs of different populations, enabling them to develop their own self-help/mutual aid groups to enhance their sense of mental well-being. PMID:23445336

  16. A computation using mutually exclusive processing is sufficient to identify specific Hedgehog signaling components

    PubMed Central

    Spratt, Spencer J.

    2013-01-01

    A system of more than one part can be deciphered by observing differences between the parts. A simple way to do this is by recording something absolute displaying a trait in one part and not in another: in other words, mutually exclusive computation. Conditional directed expression in vivo offers processing in more than one part of the system giving increased computation power for biological systems analysis. Here, I report the consideration of these aspects in the development of an in vivo screening assay that appears sufficient to identify components specific to a system. PMID:24391661

  17. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

    DOE PAGESBeta

    Tlustý, Josef; Škramlík, Ji?í; Švec, Jan; Valouch, Viktor

    2010-01-01

    The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loadsmore »in different parts of the power system.« less

  18. No effect of diffraction on Pluto-Charon mutual events

    NASA Technical Reports Server (NTRS)

    Tholen, D. J.; Hubbard, W. B.

    1988-01-01

    Mulholland and Gustafson (1987) made the interesting suggestion that observations of Pluto-Charon mutual events might show significant dependence on both wavelength and telescope aperture because of diffraction effects. In this letter, observations are presented that show the predicted effects to be absent and demonstrate that the parameters of the system are such that the events can be accurately analyzed with geometrical optics.

  19. Circumstances for Pluto-Charon mutual events in 1989

    NASA Technical Reports Server (NTRS)

    Tholen, David J.; Buie, Marc W.

    1988-01-01

    Circumstances for 90 Pluto-Charon mutual events occurring during the 1989 opposition are presented. It is found that the deepest and longest events will occur near postopposition quadrature in early August. Two new stars are selected as comparison stars for events occurring before opposition in 1989, and it is noted that the 1988 comparison stars should be used for events occurring after opposition.

  20. A Mutual Support Group for Young Problem Gamblers

    ERIC Educational Resources Information Center

    Binde, Per

    2012-01-01

    A Swedish mutual support group for young problem gamblers is described and discussed. During the study period, 116 weekly meetings occurred, usually involving six to ten participants; in total, 69 problem gamblers (66 male and three female), aged 17-25, and 23 partners and friends attended the meetings. Half the gamblers had problems with Internet…