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Sample records for aggregate production function

  1. 76 FR 56810 - Controlled Substances: 2011 Proposed Aggregate Production Quotas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... Enforcement Administration Controlled Substances: 2011 Proposed Aggregate Production Quotas AGENCY: Drug...: This notice proposes to adjust the 2011 aggregate production quotas for several controlled substances... aggregate production quotas for five synthetic cannabinoids temporarily controlled in Schedule I....

  2. A look at construction aggregates production

    USGS Publications Warehouse

    Willett, Jason Christopher

    2009-01-01

    Construction aggregates are defined as the combination of crushed stone and construction sand and gravel. Aggregates are one of the most accessible natural resources on Earth and one of the fundamental building blocks of our society. They have been used from the earliest times of our civilization for a variety of applications that have increased in number and complexity with time and technological progress. Despite the relatively low but increasing unit value of its basic products, the construction aggregates industry is a major contributor to and an indicator of the economic well-being of the nation.

  3. 21 CFR 1303.11 - Aggregate production quotas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Aggregate production quotas. 1303.11 Section 1303.11 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS Aggregate Production and Procurement Quotas § 1303.11 Aggregate production quotas. (a) The Administrator shall...

  4. Cellular strategies for regulating functional and nonfunctional protein aggregation.

    PubMed

    Gsponer, Jörg; Babu, M Madan

    2012-11-29

    Growing evidence suggests that aggregation-prone proteins are both harmful and functional for a cell. How do cellular systems balance the detrimental and beneficial effect of protein aggregation? We reveal that aggregation-prone proteins are subject to differential transcriptional, translational, and degradation control compared to nonaggregation-prone proteins, which leads to their decreased synthesis, low abundance, and high turnover. Genetic modulators that enhance the aggregation phenotype are enriched in genes that influence expression homeostasis. Moreover, genes encoding aggregation-prone proteins are more likely to be harmful when overexpressed. The trends are evolutionarily conserved and suggest a strategy whereby cellular mechanisms specifically modulate the availability of aggregation-prone proteins to (1) keep concentrations below the critical ones required for aggregation and (2) shift the equilibrium between the monomeric and oligomeric/aggregate form, as explained by Le Chatelier's principle. This strategy may prevent formation of undesirable aggregates and keep functional assemblies/aggregates under control.

  5. Biological framework for soil aggregation: Implications for ecological functions.

    NASA Astrophysics Data System (ADS)

    Ghezzehei, Teamrat; Or, Dani

    2016-04-01

    Soil aggregation is heuristically understood as agglomeration of primary particles bound together by biotic and abiotic cementing agents. The organization of aggregates is believed to be hierarchical in nature; whereby primary particles bond together to form secondary particles and subsequently merge to form larger aggregates. Soil aggregates are not permanent structures, they continuously change in response to internal and external forces and other drivers, including moisture, capillary pressure, temperature, biological activity, and human disturbances. Soil aggregation processes and the resulting functionality span multiple spatial and temporal scales. The intertwined biological and physical nature of soil aggregation, and the time scales involved precluded a universally applicable and quantifiable framework for characterizing the nature and function of soil aggregation. We introduce a biophysical framework of soil aggregation that considers the various modes and factors of the genesis, maturation and degradation of soil aggregates including wetting/drying cycles, soil mechanical processes, biological activity and the nature of primary soil particles. The framework attempts to disentangle mechanical (compaction and soil fragmentation) from in-situ biophysical aggregation and provides a consistent description of aggregate size, hierarchical organization, and life time. It also enables quantitative description of biotic and abiotic functions of soil aggregates including diffusion and storage of mass and energy as well as role of aggregates as hot spots of nutrient accumulation, biodiversity, and biogeochemical cycles.

  6. 21 CFR 1303.11 - Aggregate production quotas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Aggregate production quotas. 1303.11 Section 1303.11 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS Aggregate Production... are manufactured from it, the economic and physical availability of raw materials for use...

  7. 75 FR 35838 - Controlled Substances: Proposed Revised Aggregate Production Quotas for 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... Enforcement Administration Controlled Substances: Proposed Revised Aggregate Production Quotas for 2010 AGENCY... production quotas. SUMMARY: This notice proposes revised 2010 aggregate production quotas for controlled.... 826) requires that the Attorney General establish aggregate production quotas for each basic class...

  8. Cellular Strategies for Regulating Functional and Nonfunctional Protein Aggregation

    PubMed Central

    Gsponer, Jörg; Babu, M. Madan

    2012-01-01

    Summary Growing evidence suggests that aggregation-prone proteins are both harmful and functional for a cell. How do cellular systems balance the detrimental and beneficial effect of protein aggregation? We reveal that aggregation-prone proteins are subject to differential transcriptional, translational, and degradation control compared to nonaggregation-prone proteins, which leads to their decreased synthesis, low abundance, and high turnover. Genetic modulators that enhance the aggregation phenotype are enriched in genes that influence expression homeostasis. Moreover, genes encoding aggregation-prone proteins are more likely to be harmful when overexpressed. The trends are evolutionarily conserved and suggest a strategy whereby cellular mechanisms specifically modulate the availability of aggregation-prone proteins to (1) keep concentrations below the critical ones required for aggregation and (2) shift the equilibrium between the monomeric and oligomeric/aggregate form, as explained by Le Chatelier’s principle. This strategy may prevent formation of undesirable aggregates and keep functional assemblies/aggregates under control. PMID:23168257

  9. Protein Aggregation and Its Impact on Product Quality

    PubMed Central

    Roberts, Christopher J.

    2014-01-01

    Protein pharmaceutical products are typically active as folded monomers that are composed of one or more protein chains, such as the heavy and light chains in monoclonal antibodies that are a mainstay of current drug pipelines. There are numerous possible aggregated states for a given protein, some of which are potentially useful, while most of which are considered deleterious from the perspective of pharmaceutical product quality and performance. This review provides an overview of how and why different aggregated states of proteins occur, how this potentially impacts product quality and performance, fundamental approaches to control aggregate formation, and the practical approaches that are currently used in the pharmaceutical industry. PMID:25173826

  10. 75 FR 55828 - Controlled Substances: Final Revised Aggregate Production Quotas for 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ... Enforcement Administration Controlled Substances: Final Revised Aggregate Production Quotas for 2010 AGENCY: Drug Enforcement Administration (DEA), Justice. ACTION: Notice of final aggregate production quotas for 2010. SUMMARY: This notice establishes final 2010 aggregate production quotas for controlled...

  11. 75 FR 56137 - Controlled Substances: Proposed Aggregate Production Quotas for 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... Enforcement Administration Controlled Substances: Proposed Aggregate Production Quotas for 2011 AGENCY: Drug Enforcement Administration (DEA), Justice. ACTION: Notice of proposed year 2011 aggregate production quotas. SUMMARY: This notice proposes initial year 2011 aggregate production quotas for controlled substances...

  12. 76 FR 65537 - Controlled Substances: Proposed Aggregate Production Quotas for 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... Enforcement Administration Controlled Substances: Proposed Aggregate Production Quotas for 2012 AGENCY: Drug...: This notice proposes initial year 2012 aggregate production quotas for controlled substances in....S.C. 826) requires that the Attorney General establish aggregate production quotas for each...

  13. Exploring aggregate economic damage functions due to climate change

    SciTech Connect

    Dowlatabadi, H.; Kandlikar, M.; Patwardhan, A.

    1994-12-31

    A number of issues need to be considered when developing aggregated economic damage functions due to climate change. These include: (i) identification of production processes vulnerable to climate change, (ii) an understanding of the mechanism of vulnerability, (iii) the rate of technological advance and diffusion (iv) the issue of detection of damages and availability of response options. In this paper we will explore the implications of these considerations with the aid of an illustrative model. The findings suggest that there is a significant upward bias in damage functions calculated without consideration of these issues. Furthermore, this systematic bias is larger as climate change increases. We believe the approach explored here is a more suitable model for adoption in future integrated assessments of climate change.

  14. Soil Aggregate Stability and Grassland Productivity Associations in a Northern Mixed-Grass Prairie

    PubMed Central

    Reinhart, Kurt O.; Vermeire, Lance T.

    2016-01-01

    Soil aggregate stability data are often predicted to be positively associated with measures of plant productivity, rangeland health, and ecosystem functioning. Here we revisit the hypothesis that soil aggregate stability is positively associated with plant productivity. We measured local (plot-to-plot) variation in grassland community composition, plant (aboveground) biomass, root biomass, % water-stable soil aggregates, and topography. After accounting for spatial autocorrelation, we observed a negative association between % water-stable soil aggregates (0.25–1 and 1–2 mm size classes of macroaggregates) and dominant graminoid biomass, and negative associations between the % water-stable aggregates and the root biomass of a dominant sedge (Carex filifolia). However, variation in total root biomass (0–10 or 0–30 cm depths) was either negatively or not appreciably associated with soil aggregate stabilities. Overall, regression slope coefficients were consistently negative thereby indicating the general absence of a positive association between measures of plant productivity and soil aggregate stability for the study area. The predicted positive association between factors was likely confounded by variation in plant species composition. Specifically, sampling spanned a local gradient in plant community composition which was likely driven by niche partitioning along a subtle gradient in elevation. Our results suggest an apparent trade-off between some measures of plant biomass production and soil aggregate stability, both known to affect the land’s capacity to resist erosion. These findings further highlight the uncertainty of plant biomass-soil stability associations. PMID:27467598

  15. A deterministic aggregate production planning model considering quality of products

    NASA Astrophysics Data System (ADS)

    Madadi, Najmeh; Yew Wong, Kuan

    2013-06-01

    Aggregate Production Planning (APP) is a medium-term planning which is concerned with the lowest-cost method of production planning to meet customers' requirements and to satisfy fluctuating demand over a planning time horizon. APP problem has been studied widely since it was introduced and formulated in 1950s. However, in several conducted studies in the APP area, most of the researchers have concentrated on some common objectives such as minimization of cost, fluctuation in the number of workers, and inventory level. Specifically, maintaining quality at the desirable level as an objective while minimizing cost has not been considered in previous studies. In this study, an attempt has been made to develop a multi-objective mixed integer linear programming model that serves those companies aiming to incur the minimum level of operational cost while maintaining quality at an acceptable level. In order to obtain the solution to the multi-objective model, the Fuzzy Goal Programming approach and max-min operator of Bellman-Zadeh were applied to the model. At the final step, IBM ILOG CPLEX Optimization Studio software was used to obtain the experimental results based on the data collected from an automotive parts manufacturing company. The results show that incorporating quality in the model imposes some costs, however a trade-off should be done between the cost resulting from producing products with higher quality and the cost that the firm may incur due to customer dissatisfaction and sale losses.

  16. Ceramic ware waste as coarse aggregate for structural concrete production.

    PubMed

    García-González, Julia; Rodríguez-Robles, Desirée; Juan-Valdés, Andrés; Morán-Del Pozo, Julia M; Guerra-Romero, M Ignacio

    2015-01-01

    The manufacture of any kind of product inevitably entails the production of waste. The quantity of waste generated by the ceramic industry, a very important sector in Spain, is between 5% and 8% of the final output and it is therefore necessary to find an effective waste recovery method. The aim of the study reported in the present article was to seek a sustainable means of managing waste from the ceramic industry through the incorporation of this type of waste in the total replacement of conventional aggregate (gravel) used in structural concrete. Having verified that the recycled ceramic aggregates met all the technical requirements imposed by current Spanish legislation, established in the Code on Structural Concrete (EHE-08), then it is prepared a control concrete mix and the recycled concrete mix using 100% recycled ceramic aggregate instead of coarse natural aggregate. The concretes obtained were subjected to the appropriate tests in order to conduct a comparison of their mechanical properties. The results show that the concretes made using ceramic sanitary ware aggregate possessed the same mechanical properties as those made with conventional aggregate. It is therefore possible to conclude that the reuse of recycled ceramic aggregate to produce recycled concrete is a feasible alternative for the sustainable management of this waste.

  17. Production of manufactured aggregates from flue gas desulfurization by-products

    SciTech Connect

    Wu, M.M.; McCoy, D.C.; Fenger, M.L.; Scandrol, R.O.; Winschel, R.A.; Withum, J.A.; Statnick, R.M.

    1999-07-01

    CONSOL R and D has developed a disk pelletization process to produce manufactured aggregates from the by-products of various technologies designed to reduce sulfur emissions produced from coal utilization. Aggregates have been produced from the by-products of the Coolside and LIMB sorbent injection, the fluidized-bed combustion (FBC), spray dryer absorption (SDA), and lime and limestone wet flue gas desulfurization (FGD) processes. The aggregates produced meet the general specifications for use as road aggregate in road construction and for use as lightweight aggregate in concrete masonry units. Small field demonstrations with 1200 lb to 5000 lb of manufactured aggregates were conducted using aggregates produced from FBC ash and lime wet FGD sludge in road construction and using aggregates made from SDA ash and lime wet FGD sludge to manufacture concrete blocks. The aggregates for this work were produced with a bench-scale (200--400 lb batch) unit. In 1999, CONSOL R and D constructed and operated a 500 lb/hr integrated, continuous pilot plant. A variety of aggregate products were produced from lime wet FGD sludge. The pilot plant test successfully demonstrated the continuous, integrated operation of the process. The pilot plant demonstration was a major step toward commercialization of manufactured aggregate production from FGD by-products. In this paper, progress made in the production of aggregates from dry FGD (Coolside, LIMB, SDA) and FBC by-products, and lime wet FGD sludge is discussed. The discussion covers bench-scale and pilot plant aggregate production and aggregate field demonstrations.

  18. 21 CFR 1303.13 - Adjustments of aggregate production quotas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Adjustments of aggregate production quotas. 1303.13 Section 1303.13 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS... availability of raw materials for use in manufacturing and for inventory purposes, yield and stability...

  19. Production of lightweight aggregates from washing aggregate sludge and fly ash

    NASA Astrophysics Data System (ADS)

    González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Rodas, Magdalena

    2010-05-01

    Increasing generation of wastes is one of the main environmental problems in industrialised countries. Heat treatment at high temperatures can convert some types of wastes into ceramic products with a wide range of microstructural features and properties (Bethanis et al., 2004). A lightweight aggregate (LWA) is a granular material with a bulk density (bd) not exceeding 1.20 g/cm3 or with a particle density not exceeding 2.00 g/cm3 (UNE-EN-13055-1, 2003). They have become a focus of interest because the low particle density and the low bulk density entail a decrease in the load transmitted to the ground, and less work and effort are required to transport them (De' Gennaro et al., 2004). The benefits associated with these low densities, which are due to the formation of voids and pores, are very good thermal and acoustic insulation and materials with a good resistance to fire (Benbow, 1987; Fakhfakh et al., 2007). The objective was to recycle fly ash, used motor oil from cars and mineral wastes from washing aggregate sludge, in order to obtain a usable material such as lightweight aggregates, and also to ensure that they are of good quality for different applications. Raw materials have been physically, chemically and mineralogically characterized. On the basis of the results obtained, they were mixed, milled to a grain size of less than 200 μm (Yasuda, 1991), formed into pellets, pre-heated for 5 min and sintered in a rotary kiln at 1150°C, 1175°C, 1200°C and 1225°C for 10 and 15 min at each temperature (Theating). Effects of raw material characteristics, heating temperature and dwell time on the following LWAs properties were determined: loss on ignition (LOI), bloating index (BI), loose bulk density (bd), apparent and dry particle density (ad, dd), voids (H), water absorption (WA24h) and compressive strength (S). The products obtained were lightweight aggregates in accordance with norm UNE-EN-13055-1 (bd ≤1.20 g/cm3 or particle density ≤2.00 g/cm3). LWAs

  20. PRODUCTION OF CONSTRUCTION AGGREGATES FROM FLUE GAS DESULFURIZATION SLUDGE

    SciTech Connect

    M.M. Wu; D.C. McCoy; R.O. Scandrol; M.L. Fenger; J.A. Withum; R.M. Statnick

    2000-05-01

    The three main conclusions of this report are: (1) The pilot plant successfully demonstrated the continuous, fully-integrated, long-term process operation, including the mixing, pelletizing, and curing steps for aggregate production. The curing vessel, which was designed for the pilot plant test, was operated in a mass flow mode and performed well during pilot plant operation. (2) The pilot plant test demonstrated process flexibility. The same equipment was used to produce lightweight, medium-weight, and road aggregates. The only change was the mix formulation. Aggregates were produced from a variety of mix designs and from FGD sludge with solids concentrations between 45.0% and 56.7% and moisture contents between 55.0% and 43.3%. (3) The pilot plant provided operating data and experience to design and cost a commercial plant, which was not part of the cooperative agreement.

  1. Lightweight aggregate production from claystone and shale in Bangladesh

    USGS Publications Warehouse

    Parker, Norbert A.; Khan, M.A.

    1976-01-01

    Muffle furnace tests were made on samples of clay, claystone, and shale collected in the Chittagong and Dacca areas of East Pakistan to determine their amenability to bloating for the commercial production of light-weight aggregate. Several areas, sampled in some detail, were selected for investigation because of their proximity to market, and accessibility to fuel and electricity. Muffle furnace tests show that the clay, claystone, and shale are natural bloaters at temperatures in the 1700? to 2200? F range, and do not require additives. The most desirable deposit, insofar as producing a strong aggregate is concerned, can be determined only by pilot-kiln testing and by crushing-strength tests made on concrete test cylinders. Reserves of suitable raw material are large in both the Chittagong and Dacca areas.

  2. 77 FR 39737 - Controlled Substances: Proposed Adjustment to the Aggregate Production Quotas for 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ...] Controlled Substances: Proposed Adjustment to the Aggregate Production Quotas for 2012 AGENCY: Drug...: This notice proposes to adjust the 2012 aggregate production quotas for several controlled substances... establish aggregate production quotas for each basic class of controlled substance listed in schedules I...

  3. DURABILITY EVALUATION AND PRODUCTION OF MANUFACTURED AGGREGATES FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

    M. M. Wu

    2005-02-01

    Under the cooperative agreement with DOE, the Research and Development Department of CONSOL Energy (CONSOL R&D), teamed with Universal Aggregates, LLC, to conduct a systematic study of the durability of aggregates manufactured using a variety of flue gas desulfurization (FGD), fluidized-bed combustion (FBC) and fly ash specimens with different chemical and physical properties and under different freeze/thaw, wet/dry and long-term natural weathering conditions. The objectives of the study are to establish the relationships among the durability and characteristics of FGD material, FBC ash and fly ash, and to identify the causes of durability problems, and, ultimately, to increase the utilization of FGD material, FBC ash and fly ash as a construction material. Manufactured aggregates made from FGD material, FBC ash and fly ash, and products made from those manufactured aggregates were used in the study. The project is divided into the following activities: sample collection and characterization; characterization and preparation of manufactured aggregates; determination of durability characteristics of manufactured aggregates; preparation and determination of durability characteristics of manufactured aggregate products; and data evaluation and reporting.

  4. Preparation and functional evaluation of cell aggregates incorporating gelatin microspheres with different degradabilities.

    PubMed

    Tajima, Shuhei; Tabata, Yasuhiko

    2013-10-01

    The objective of this study was to investigate the viability and biological functions of cells in their aggregates incorporating gelatin microspheres with different degradabilities. After being prepared by a water-in-oil emulsion procedure, the gelatin microspheres were dehydrothermally crosslinked at 140°C for various time periods. In vitro degradation tests showed that the gelatin microspheres were slowly degraded slowly with an increase in the crosslinking time. When MC3T3-E1 cells were cultured with the gelatin hydrogel microspheres in the round U-bottom wells of 96-well microplates which had been coated with poly(vinyl alcohol), cell aggregates with homogeneously distributed gelatin microspheres were formed. A large amount of slowly degraded gelatin microspheres remained in the cell aggregates for long time periods, while a higher proliferation of MC3T3-E1 cells was observed. When evaluated as a measure of aerobic glycolysis, the ratio of l-lactic acid production:glucose consumption of MC3T3-E1 cells was lower for MC3T3-E1 cells in the cell aggregates incorporating slowly degraded gelatin microspheres than for aggregates incorporating rapidly degraded ones. The alkaline phosphatase activity and calcium content of MC3T3-E1 cells were higher for cell aggregates incorporating slowly degraded gelatin microspheres. It is possible that the incorporation of gelatin hydrogel microspheres with slow degradability enabled the permeation of oxygen and nutrients into the cell aggregates for longer time periods, resulting in better culture conditions for the survival, proliferation and differentiation of the cells.

  5. Mine-to-Mill Optimization of Aggregate Production

    SciTech Connect

    Greg Adel; Toni Kojovic; Darren Thornton

    2006-09-30

    Mine-to-Mill optimization is a total systems approach to the reduction of energy and cost in mining and processing. Developed at the Julius Krutschnitt Mineral Research Center in Queensland, Australia, the Mine-to-Mill approach attempts to minimize energy consumption through optimization of all steps in the size reduction process. The approach involves sampling and modeling of blasting and processing, followed by computer simulation to optimize the operation and develop alternatives. The most promising alternatives are implemented, and sampling is conducted to quantify benefits. In the current project, the primary objective was to adapt Mine-to-Mill technology to the aggregates industry. The first phase of this work was carried out at the Bealeton Quarry near Fredericksburg, Virginia. The second phase was carried out at the Pittsboro Quarry south of Chapel Hill, North Carolina. Both quarries are operated by Luck Stone Corporation of Richmond, Virginia. As a result of the work, several conclusions can be drawn from the project which should assist DOE in assessing the applicability of the Mine-to-Mill approach to the aggregates industry. 1. Implementation of MTM guidelines at Pittsboro has resulted in tangible improvements in productivity. It is clear that MTM guidelines represent an energy savings of around 5% (primary and secondary) and an overall energy savings of 1%. This 1-5% energy savings is also consistent with simulated results for Bealeton had side-by-side shots used to evaluate the technology been carried out in the same rockmass. 2. Luck Stone clearly runs their operations at a high standard. Hence the percentage improvement realized in this project may represent the lower end of what might be expected overall in the aggregates industry. 3. Variability in ore types across both Bealeton and Pittsboro suggests a 2:1 difference in hardness which contradicts the misconception that quarry rock is homogenous. Therefore, the idea of comparing side-by-side blasts

  6. Production of mineral aggregates in quartz tumbling experiments

    NASA Astrophysics Data System (ADS)

    Nørnberg, Per; Finster, Kai; Pall Gunnlaugsson, Haraldur; Knak Jensen, Svend; Merrison, Jonathan Peter

    2013-04-01

    Introduction Tumbling experiments with quartz sand with the purpose of tracing the effect of broken bonds in mineral surfaces resulted in an unexpected production of aggregates. These aggregates are a few microns in diameter, spherical and resembling tiny white "snowballs." Particle comminution by aeolian and other natural weathering processes are known in soil science and is often seen as an increase of fine particles towards the top of soil profiles (Nørnberg, P. 1987, 1988, 2002, J.S. Wright 2007). When mineral grains collide in aeolian processes they break up along weakness zones in the crystal lattice. This mechanism causes broken bonds between atoms in the crystal lattice and results in reactive groups in the mineral surface. This mechanism provides the background for experiments to investigate the oxidation processes of magnetite on the planet Mars. The primary magnetic iron oxide phase on Mars is to day known to be magnetite and the colour of the dust on Mars is most likely due to hematite. To investigate if the oxidation process could take place without going over dissolution and precipitation in water, experiments with tumbling of quartz grains in sealed glass containers along with magnetite were started. The idea was that activated bonds at the surface of quartz could oxidize magnetite and convert it to hematite over time. This proved to be the case (Merrison, J.P. et al. 2010). However, in these experiments we observed the formation of the white aggregates which has been the subject of the study that we present here. Results of tumbling experiments Commercially available quarts (Merck) was sieved to obtain the fraction between 125 and 1000 µm. This fraction was tumbled in glass containers for months and resulted in production of a significant amount of fine grained material (Merrison, J.P et al. 2010). A part of this fine fraction consists of the "snowball"-like aggregates which is a fragile element with relatively high specific surface. The physical

  7. VIIRS Product Aggregation and Packaging. [Visible/Infrared Imager Radiometer data products

    NASA Technical Reports Server (NTRS)

    Wolfe, Robert

    2006-01-01

    Areas where the end-users can help define the Visible/Infrared Imager Radiometer Suite (VIIRS) products distributed by NOAA include: temporal aggregation, band packaging, and gelolocation packaging. Proposals in these areas are presented along with background information, advantages and disadvantates of each proposal. The proposals are based on experience with NASA EOS missions and programs (MODIS and SeaWIFS).

  8. Production of lightweight aggregate from industrial waste and carbon dioxide.

    PubMed

    Gunning, Peter J; Hills, Colin D; Carey, Paula J

    2009-10-01

    The concomitant recycling of waste and carbon dioxide emissions is the subject of developing technology designed to close the industrial process loop and facilitate the bulk-re-use of waste in, for example, construction. The present work discusses a treatment step that employs accelerated carbonation to convert gaseous carbon dioxide into solid calcium carbonate through a reaction with industrial thermal residues. Treatment by accelerated carbonation enabled a synthetic aggregate to be made from thermal residues and waste quarry fines. The aggregates produced had a bulk density below 1000 kg/m(3) and a high water absorption capacity. Aggregate crushing strengths were between 30% and 90% stronger than the proprietary lightweight expanded clay aggregate available in the UK. Cast concrete blocks containing the carbonated aggregate achieve compressive strengths of 24 MPa, making them suitable for use with concrete exposed to non-aggressive service environments. The energy intensive firing and sintering processes traditionally required to produce lightweight aggregates can now be augmented by a cold-bonding, low energy method that contributes to the reduction of green house gases to the atmosphere.

  9. Defensive allomones function as aggregation pheromones in diapausing Ladybird Beetles, Hippodamia convergens.

    PubMed

    Wheeler, Christopher A; Cardé, Ring T

    2013-06-01

    Identification of the stimuli responsible for the formation of an aggregation can be used to distinguish between social and non-social aggregations and help in the process of identifying the adaptive benefits of the gregarious behavior. The convergent ladybird beetle, Hippodamia convergens, forms dense aggregations during winter diapause. The mechanisms of conspecific attraction and hibernacula site selection of H. convergens are not well understood. In laboratory and field bioassays, we evaluated the role of three defensive compounds in the formation of H. convergens aggregations. Diapausing H. convergens aggregated within the section of an arena exposed to alkylmethoxypyrazines. 2-Isobutyl-3-methoxypyrazine (IBMP) caused the strongest aggregative effect. Beetles also aggregated to some doses of 2-sec-butyl-3-methoxypyrazine, but appeared to be repelled at higher doses. A third constituent, 2-isopropyl-3-methoxypyrazine, generally had little effect on the distribution of beetles, although the highest dose tested was repellent. Beetles also aggregated to a blend of these alkylmethoxypyrazines at their natural ratio. During fall migration to overwintering sites, more beetles aggregated in artificial hibernacula baited with IBMP, confirming its function as an aggregation pheromone. These three pyrazines also function as warning odors that, in conjunction with other aposematic displays (contrasting red and black coloration, gregarious behavior, reflex bleeding), contribute to the multi-modal, anti-predatory defense of coccinellid beetles and some other arthropods. Confirmation of the role of some alkylmethoxypyrazines in coccinellid aggregations suggests that these defensive allomones have been co-opted for intraspecific communication.

  10. Delicate balance between functionally required flexibility and aggregation risk in a β-rich protein.

    PubMed

    Ferrolino, Mylene C; Zhuravleva, Anastasia; Budyak, Ivan L; Krishnan, Beena; Gierasch, Lila M

    2013-12-10

    Susceptibility to aggregation is general to proteins because of the potential for intermolecular interactions between hydrophobic stretches in their amino acid sequences. Protein aggregation has been implicated in several catastrophic diseases, yet we still lack in-depth understanding about how proteins are channeled to this state. Using a predominantly β-sheet protein whose folding has been explored in detail, cellular retinoic acid-binding protein 1 (CRABP1), as a model, we have tackled the challenge of understanding the links between a protein's natural tendency to fold, 'breathe', and function with its propensity to misfold and aggregate. We identified near-native dynamic species that lead to aggregation and found that inherent structural fluctuations in the native protein, resulting in opening of the ligand-entry portal, expose hydrophobic residues on the most vulnerable aggregation-prone sequences in CRABP1. CRABP1 and related intracellullar lipid-binding proteins have not been reported to aggregate inside cells, and we speculate that the cellular concentration of their open, aggregation-prone conformations is sufficient for ligand binding but below the critical concentration for aggregation. Our finding provides an example of how nature fine-tunes a delicate balance between protein function, conformational variability, and aggregation vulnerability and implies that with the evolutionary requirement for proteins to fold and function, aggregation becomes an unavoidable but controllable risk.

  11. In vitro effects of mercury on platelet aggregation, thromboxane and vascular prostacyclin production.

    PubMed

    Caprino, L; Togna, A R; Cebo, B; Dolci, N; Togna, G

    1983-01-01

    Mercuric chloride [25-50 micrograms/ml platelet-rich plasma (PRP)] lowers the threshold concentration of arachidonic acid (AA) required for triggering rabbit platelet aggregation and causes a marked increase of thromboxane production. The metal, added as HgCl2, does not modify (50 micrograms/ml PRP) or block (100 micrograms/ml PRP) the platelet aggregation wave induced by a normal aggregating dose of AA. Whether or not AA-induced platelet aggregation takes place, a large increase in thromboxane production is observed. Methyl mercury, assayed as reference drug, induces platelet aggregation and a significant increase of thromboxane levels. Finally, HgCl2 and methyl mercury, in a concentration range of 0.125-0.5 micrograms/microliters in the incubation liquid, induce an increased prostacyclin release from rat aortic tissue.

  12. Legal but lethal: functional protein aggregation at the verge of toxicity

    PubMed Central

    Falsone, Angelika; Falsone, S. Fabio

    2015-01-01

    Many neurodegenerative disorders are linked to irreversible protein aggregation, a process that usually comes along with toxicity and serious cellular damage. However, it is emerging that protein aggregation can also serve for physiological purposes, as impressively shown for prions. While the aggregation of this protein family was initially considered exclusively toxic in mammalians organisms, it is now almost clear that many other proteins adopt prion-like attributes to rationally polymerize into higher order complexes with organized physiologic roles. This implies that cells can tolerate at least in some measure the accumulation of inherently dangerous protein aggregates for functional profit. This review summarizes currently known strategies that living organisms adopt to preserve beneficial aggregation, and to prevent the catastrophic accumulation of toxic aggregates that frequently accompany neurodegeneration. PMID:25741240

  13. Aggregation-based detection of M. smegmatis using D-arabinose-functionalized fluorescent silica nanoparticles.

    PubMed

    Jayawardana, Kalana W; Wijesundera, Samurdhi A; Yan, Mingdi

    2015-11-14

    Fluorescein-doped silica nanoparticles (FSNPs) functionalized with D-arabinose (Ara) showed strong interactions with Mycobacterium smegmatis (M. smegmatis) and caused the bacteria to aggregate. This aggregate formation was used as a means to detect M. smegmatis at the concentration of 10(4) CFU per mL.

  14. Protein aggregation in bacteria: the thin boundary between functionality and toxicity.

    PubMed

    Bednarska, Natalia G; Schymkowitz, Joost; Rousseau, Frederic; Van Eldere, Johan

    2013-09-01

    Misfolding and aggregation of proteins have a negative impact on all living organisms. In recent years, aggregation has been studied in detail due to its involvement in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's diseases, and type II diabetes--all associated with accumulation of amyloid fibrils. This research highlighted the central importance of protein homeostasis, or proteostasis for short, defined as the cellular state in which the proteome is both stable and functional. It implicates an equilibrium between synthesis, folding, trafficking, aggregation, disaggregation and degradation. In accordance with the eukaryotic systems, it has been documented that protein aggregation also reduces fitness of bacterial cells, but although our understanding of the cellular protein quality control systems is perhaps most detailed in bacteria, the use of bacterial proteostasis as a drug target remains little explored. Here we describe protein aggregation as a normal physiological process and its role in bacterial virulence and we shed light on how bacteria defend themselves against the toxic threat of aggregates. We review the impact of aggregates on bacterial viability and look at the ways that bacteria use to maintain a balance between aggregation and functionality. The proteostasis in bacteria can be interrupted via overexpression of proteins, certain antibiotics such as aminoglycosides, as well as antimicrobial peptides--all leading to loss of cell viability. Therefore intracellular protein aggregation and disruption of proteostatic balance in bacteria open up another strategy that should be explored towards the discovery of new antimicrobials.

  15. Proteins in aggregates functionally impact multiple neurodegenerative disease models by forming proteasome-blocking complexes

    PubMed Central

    Ayyadevara, Srinivas; Balasubramaniam, Meenakshisundaram; Gao, Yuan; Yu, Li-Rong; Alla, Ramani; Shmookler Reis, Robert

    2015-01-01

    Age-dependent neurodegenerative diseases progressively form aggregates containing both shared components (e.g., TDP-43, phosphorylated tau) and proteins specific to each disease. We investigated whether diverse neuropathies might have additional aggregation-prone proteins in common, discoverable by proteomics. Caenorhabditis elegans expressing unc-54p/Q40::YFP, a model of polyglutamine array diseases such as Huntington's, accrues aggregates in muscle 2–6 days posthatch. These foci, isolated on antibody-coupled magnetic beads, were characterized by high-resolution mass spectrometry. Three Q40::YFP-associated proteins were inferred to promote aggregation and cytotoxicity, traits reduced or delayed by their RNA interference knockdown. These RNAi treatments also retarded aggregation/cytotoxicity in Alzheimer's disease models, nematodes with muscle or pan-neuronal Aβ1–42 expression and behavioral phenotypes. The most abundant aggregated proteins are glutamine/asparagine-rich, favoring hydrophobic interactions with other random-coil domains. A particularly potent modulator of aggregation, CRAM-1/HYPK, contributed < 1% of protein aggregate peptides, yet its knockdown reduced Q40::YFP aggregates 72–86% (P < 10−6). In worms expressing Aβ1–42, knockdown of cram-1 reduced β-amyloid 60% (P < 0.002) and slowed age-dependent paralysis > 30% (P < 10−6). In wild-type worms, cram-1 knockdown reduced aggregation and extended lifespan, but impaired early reproduction. Protection against seeded aggregates requires proteasome function, implying that normal CRAM-1 levels promote aggregation by interfering with proteasomal degradation of misfolded proteins. Molecular dynamic modeling predicts spontaneous and stable interactions of CRAM-1 (or human orthologs) with ubiquitin, and we verified that CRAM-1 reduces degradation of a tagged-ubiquitin reporter. We propose that CRAM-1 exemplifies a class of primitive chaperones that are initially protective and highly

  16. Lactose-Functionalized Dendrimers Arbitrate the Interaction of Galectin-3/MUC1 Mediated Cancer Cellular Aggregation

    PubMed Central

    Michel, Anna K.; Nangia-Makker, Pratima; Raz, Avraham

    2015-01-01

    By using lactose-functionalized poly(amidoamine) dendrimers as a tunable multivalent platform, we studied cancer cell aggregation in three different cell lines (A549, DU-145, and HT-1080) with galectin-3. We found that small lactose-functionalized G(2)-dendrimer 1 inhibited galectin-3-induced aggregation of the cancer cells. In contrast, dendrimer 4 (a larger, generation 6 dendrimer with 100 carbohydrate end groups) caused cancer cells to aggregate through a galectin-3 pathway. This study indicates that inhibition of cellular aggregation occurred because 1 provided competitive binding sites for galectin-3 (compared to its putative cancer cell ligand, TF-antigen on MUC1). Dendrimer 4, in contrast, provided an excess of ligands for galectin-3 binding; this caused crosslinking and aggregation of cells to be increased. PMID:25138772

  17. Enhanced in vitro formation and antibiotic resistance of nonattached Pseudomonas aeruginosa aggregates through incorporation of neutrophil products.

    PubMed

    Caceres, Silvia M; Malcolm, Kenneth C; Taylor-Cousar, Jennifer L; Nichols, David P; Saavedra, Milene T; Bratton, Donna L; Moskowitz, Samuel M; Burns, Jane L; Nick, Jerry A

    2014-11-01

    Pseudomonas aeruginosa is a major pathogen in cystic fibrosis (CF) lung disease. Children with CF are routinely exposed to P. aeruginosa from the natural environment, and by adulthood, 80% of patients are chronically infected. P. aeruginosa in the CF airway exhibits a unique biofilm-like structure, where it grows in small clusters or aggregates of bacteria in association with abundant polymers of neutrophil-derived components F-actin and DNA, among other components. These aggregates differ substantially in size and appearance compared to surface-attached in vitro biofilm models classically utilized for studies but are believed to share properties of surface-attached biofilms, including antibiotic resistance. However, little is known about the formation and function of surface-independent modes of biofilm growth, how they might be eradicated, and quorum sensing communication. To address these issues, we developed a novel in vitro model of P. aeruginosa aggregates incorporating human neutrophil-derived products. Aggregates grown in vitro and those found in CF patients' sputum samples were morphologically similar; viable bacteria were distributed in small pockets throughout the aggregate. The lasA quorum sensing gene was differentially expressed in the presence of neutrophil products. Importantly, aggregates formed in the presence of neutrophils acquired resistance to tobramycin, which was lost when the aggregates were dispersed with DNase, and antagonism of tobramycin and azithromycin was observed. This novel yet simple in vitro system advances our ability to model infection of the CF airway and will be an important tool to study virulence and test alternative eradication strategies against P. aeruginosa.

  18. FITPULS: a code for obtaining analytic fits to aggregate fission-product decay-energy spectra. [In FORTRAN

    SciTech Connect

    LaBauve, R.J.; George, D.C.; England, T.R.

    1980-03-01

    The operation and input to the FITPULS code, recently updated to utilize interactive graphics, are described. The code is designed to retrieve data from a library containing aggregate fine-group spectra (150 energy groups) from fission products, collapse the data to few groups (up to 25), and fit the resulting spectra along the cooling time axis with a linear combination of exponential functions. Also given in this report are useful results for aggregate gamma and beta spectra from the decay of fission products released from /sup 235/U irradiated with a pulse (10/sup -4/ s irradiation time) of thermal neutrons. These fits are given in 22 energy groups that are the first 22 groups of the LASL 25-group decay-energy group structure, and the data are expressed both as MeV per fission second and particles per fission second; these pulse functions are readily folded into finite fission histories. 65 figures, 11 tables.

  19. [Changes of platelet aggregation function of apheresis collected platelets and soluble P-selectin during storage].

    PubMed

    Xie, Zuo-Ting; Yang, Li-Hong; Tao, Zhi-Hua; Wang, Ming-Shan; Hong, Jun-Ying; Zhou, Wu; Chen, Zeng-Qiang; Dai, Mei-Jie

    2008-10-01

    The objective of this study was to explore the changes of aggregation function of apheresis platelets and soluble P-selectin (sP-selectin) during storage. 20 samples of apheresis platelets were collected, and the aggregation function were examined by function test and the level of sP-selectin every day in storage of 5 days. The results showed that the aggregation function of platelets declined obviously during storage, there were significant differences between the first-day group and any of the other groups (p < 0.01). The max platelet aggregation rate was < or = 3% in the fourth-day group; sP-selectin level in plasma increased with prolong of storage time; there were significant differences between the first-day group and any of the other groups (p < 0.05). In conclusion, platelets were activated continuously during storage, while its aggregation function declines significantly. The ability of platelet aggregation to response to ADP loses almost completely since the fourth day during platelet storage. It should be paid more attention to the damage of apheresis collected platelets during storage.

  20. Estimating equilibrium constants for aggregation from the product distribution of a dynamic combinatorial library.

    PubMed

    Hunt, Rosemary A R; Ludlow, R Frederick; Otto, Sijbren

    2009-11-19

    Multicomponent chemical systems that exhibit a network of covalent and intermolecular interactions may produce interesting and often unexpected chemical or physical behavior. The formation of aggregates is a well-recognized example and presents a particular analytical challenge. We now report the development of a numerical fitting method capable of estimating equilibrium constants for the formation of aggregates from the product distribution of a dynamic combinatorial library containing self-recognizing library members.

  1. A new multi-period linguistic aggregation operator and its application to financial product selection

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoli; Yang, Wei

    2013-03-01

    In this paper, we propose a new aggregation operator, dynamic 2-tuple linguistic weighted averaging (DTWA) operator, to aggregate linguistic information given in multiple periods. The properties of the new operator are studied and a new multiple attribute decision making method based on the new operator is proposed. Finally, financial product selection problem is provided to illustrate the the proposed method in financial decision making problem.

  2. 21 CFR 1303.13 - Adjustments of aggregate production quotas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... affecting medical, scientific, research, and industrial needs in the United States and lawful export..., potential disruptions to production (including possible labor strikes), and recent unforeseen...

  3. The Role of Aggregates of Therapeutic Protein Products in Immunogenicity: An Evaluation by Mathematical Modeling

    PubMed Central

    Yin, Liusong; Chen, Xiaoying; Tiwari, Abhinav; Vicini, Paolo; Hickling, Timothy P.

    2015-01-01

    Therapeutic protein products (TPP) have been widely used to treat a variety of human diseases, including cancer, hemophilia, and autoimmune diseases. However, TPP can induce unwanted immune responses that can impact both drug efficacy and patient safety. The presence of aggregates is of particular concern as they have been implicated in inducing both T cell-independent and T cell-dependent immune responses. We used mathematical modeling to evaluate several mechanisms through which aggregates of TPP could contribute to the development of immunogenicity. Modeling interactions between aggregates and B cell receptors demonstrated that aggregates are unlikely to induce T cell-independent immune responses by cross-linking B cell receptors because the amount of signal transducing complex that can form under physiologically relevant conditions is limited. We systematically evaluate the role of aggregates in inducing T cell-dependent immune responses using a recently developed multiscale mechanistic mathematical model. Our analysis indicates that aggregates could contribute to T cell-dependent immune response by inducing high affinity epitopes which may not be present in the nonaggregated TPP and/or by enhancing danger signals to break tolerance. In summary, our computational analysis is suggestive of novel insights into the mechanisms underlying aggregate-induced immunogenicity, which could be used to develop mitigation strategies. PMID:26682236

  4. Mine-to-Mill Optimization of Aggregate Production

    SciTech Connect

    Greg Adel; Toni Kojovic; Darren Thornton

    2006-06-01

    Mine-to-Mill optimization is a total systems approach to the reduction of energy and cost in mining and mineral processing operations. Developed at the Julius Krutschnitt Mineral Research Centre (JKMRC) in Queensland, Australia, the Mine-to-Mill approach attempts to minimize energy consumption through the optimization of all steps in the size reduction process. The approach involves sampling and modeling of blasting and processing, followed by computer simulation to optimize the operation and develop alternatives. The most promising alternatives are implemented, and sampling is conducted to quantify energy savings. In the current project, the primary objective is to adapt the JKMRC Mine-to-Mill technology to the aggregates industry. The second phase of this project is being carried out at the Pittsboro Quarry located south of Chapel Hill, North Carolina. This quarry is owned by 3M Corporation and operated by Luck Stone. Based on lessons learned from the first phase work, long-term monitoring ({approx} three months) of all quarry operations is being carried out to minimize the impact of geological changes during the mining process. To date, the blasting and processing operations have been audited and modeled, the long-term monitoring of current Luck Stone practice has been completed, and a modified blasting approach has been implemented based on the results of simulations using JKSimBlast and JKSimPlant. The modified blasting approach is expected to increase the primary throughput by 15% and the secondary throughput by approximately 6%, with an overall specific energy reduction of around 1%. Long-term monitoring is currently underway to evaluate the impact the modified blasting approach. This report summarizes the current status of work at the Pittsboro Quarry.

  5. Incremental state aggregation for value function estimation in reinforcement learning.

    PubMed

    Mori, Takeshi; Ishii, Shin

    2011-10-01

    In reinforcement learning, large state and action spaces make the estimation of value functions impractical, so a value function is often represented as a linear combination of basis functions whose linear coefficients constitute parameters to be estimated. However, preparing basis functions requires a certain amount of prior knowledge and is, in general, a difficult task. To overcome this difficulty, an adaptive basis function construction technique has been proposed by Keller recently, but it requires excessive computational cost. We propose an efficient approach to this difficulty, in which the problem of approximating the value function is decomposed into a number of subproblems, each of which can be solved with small computational cost. Computer experiments show that the CPU time needed by our method is much smaller than that by the existing method.

  6. Ubiquitin-independent function of optineurin in autophagic clearance of protein aggregates

    PubMed Central

    Korac, Jelena; Schaeffer, Veronique; Kovacevic, Igor; Clement, Albrecht M.; Jungblut, Benno; Behl, Christian; Terzic, Janos; Dikic, Ivan

    2013-01-01

    SUMMARY Aggregation of misfolded proteins and the associated loss of neurons are considered as a hallmark of numerous neurodegenerative diseases. Optineurin is present in protein inclusions observed in various neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), Huntington’s disease, Alzheimer’s disease, Parkinson’s disease, Creutzfeld-Jacob disease and Pick’s disease. Optineurin deletion mutations have also been described in ALS patients. However, the role of optineurin in mechanisms of protein aggregation remains unclear. In this report, we demonstrate that optineurin recognized various protein aggregates via its C-terminal coiled-coil domain in a ubiquitin-independent manner. We also show that optineurin depletion significantly increase protein aggregation in HeLa cells and morpholino-silencing of the optineurin ortholog in zebrafish causes the motor axonopathy phenotype similar to a zebrafish model of ALS. A more severe phenotype is observed when optineurin is depleted in zebrafish carrying ALS mutations. Furthermore, TANK1 binding kinase 1 (TBK1) is co-localized with optineurin on protein aggregates and is important in clearance of protein aggregates through the autophagy-lysosome pathway. TBK1 phosphorylates optineurin at position Ser-177 and regulates its ability to interact with autophagy modifiers. This study provides evidence for a ubiquitin-independent function of optineurin in autophagic clearance of protein aggregates as well as additional relevance for TBK1 as an upstream regulator of the autophagic pathway. PMID:23178947

  7. Photo-fermentative bacteria aggregation triggered by L-cysteine during hydrogen production

    PubMed Central

    2013-01-01

    Background Hydrogen recovered from organic wastes and solar energy by photo-fermentative bacteria (PFB) has been suggested as a promising bioenergy strategy. However, the use of PFB for hydrogen production generally suffers from a serious biomass washout from photobioreactor, due to poor flocculation of PFB. In the continuous operation, PFB cells cannot be efficiently separated from supernatant and rush out with effluent from reactor continuously, which increased the effluent turbidity, meanwhile led to increases in pollutants. Moreover, to replenish the biomass washout, substrate was continuously utilized for cell growth rather than hydrogen production. Consequently, the poor flocculability not only deteriorated the effluent quality, but also decreased the potential yield of hydrogen from substrate. Therefore, enhancing the flocculability of PFB is urgent necessary to further develop photo-fermentative process. Results Here, we demonstrated that L-cysteine could improve hydrogen production of Rhodopseudomonas faecalis RLD-53, and more importantly, simultaneously trigger remarkable aggregation of PFB. Experiments showed that L-cysteine greatly promoted the production of extracellular polymeric substances, especially secretion of protein containing more disulfide bonds, and help for enhancement stability of floc of PFB. Through formation of disulfide bonds, L-cysteine not only promoted production of EPS, in particular the secretion of protein, but also stabilized the final confirmation of protein in EPS. In addition, the cell surface elements and functional groups, especially surface charged groups, have also been changed by L-cysteine. Consequently, absolute zeta potential reached a minimum value at 1.0 g/l of L-cysteine, which obviously decreased electrostatic repulsion interaction energy based on DLVO theory. Total interaction energy barrier decreased from 389.77 KT at 0.0 g/l of L-cysteine to 127.21 kT at 1.0 g/l. Conclusions Thus, the strain RLD-53 overcame the

  8. COIN Project: Towards a zero-waste technology for concrete aggregate production in Norway

    NASA Astrophysics Data System (ADS)

    Cepuritis, Rolands; Willy Danielsen, Svein

    2014-05-01

    COIN Project: Towards a zero-waste technology for concrete aggregate production in Norway Rolands Cepuritis, Norcem/NTNU and Svein Willy Danielsen, SINTEF Aggregate production is a mining operation where no purification of the "ore" is necessary. Still it is extremely rare that an aggregate production plant is operating on the basis of zero-waste concept. This is since historically the fine crushed aggregate (particles with a size of less than 2, 4 or sometimes 8 mm) has been regarded as a by-product or waste of the more valuable coarse aggregate production. The reason is that the crushed coarse aggregates can easily replace coarse rounded natural stones in almost any concrete composition; while, the situation with the sand is different. The production of coarse aggregate normally yields fine fractions with rough surface texture, flaky or elongated particles an inadequate gradation. When such a material replaces smooth and rounded natural sand grains in a concrete mix, the result is usually poor and much more water and cement has to be used to achieve adequate concrete flow. The consequences are huge stockpiles of the crushed fine fractions that can't be sold (mass balance problems) for the aggregate producers, sustainability problems for the whole industry and environmental issues for society due to dumping and storing of the fine co-generated material. There have been attempts of utilising the material in concrete before; however, they have mostly ended up in failure. There have been attempts to adjust the crushed sand to the properties of the natural sand, which would still give a lot of waste, especially if the grading would have to be adjusted and the high amounts of fines abundantly present in the crushed sand would have to be removed. Another fundamental reason for failure has been that historically such attempts have mainly ended up in a research carried out by people (both industrial and academic) with aggregate background (= parties willing to find market

  9. Ecology and function of culturable microbes in soil aggregation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil structure plays a dominant role in the physical protection of soil organic matter by controlling microbial access to substrate, microbial turnover processes, and food web interactions. Good soil structure results in soil productivity, a cornerstone of agricultural sustainability. While there is...

  10. Relationship between functional properties and aggregation changes of whey protein induced by high pressure microfluidization.

    PubMed

    Liu, Cheng-Mei; Zhong, Jun-Zhen; Liu, Wei; Tu, Zong-Cai; Wan, Jie; Cai, Xiao-Fei; Song, Xin-Yun

    2011-05-01

    Aggregation changes of whey protein induced by high-pressure microfluidization (HPM) treatment have been investigated in relation with their functional properties. Whey protein was treated with HPM under pressure from 40 to 160 MPa. Functional properties (solubility, foaming, and emulsifying properties) of whey protein concentrate (WPC) ultrafiltered from fluid whey were evaluated. The results showed significant modifications in the solubility (30% to 59%) and foaming properties (20% to 65%) of WPC with increasing pressure. However, emulsifying property of WPC treated at different pressures was significantly worse than untreated sample. To better understand the mechanism of the modification by HPM, the HPM-induced aggregation changes were examined using particle size distribution, scanning electron microscopy, and hydrophobicity. It was indicated that HPM induced 2 kinds of aggregation changes on WPC: deaggregation and reaggregation of WPC, which resulted in the changes of functional properties of WPC modified by HPM.

  11. Postfragmentation density function for bacterial aggregates in laminar flow

    NASA Astrophysics Data System (ADS)

    Byrne, Erin; Bortz, David M.; Dzul, Steve; Solomon, Michael; Younger, John

    2011-04-01

    The postfragmentation probability density of daughter flocs is one of the least well-understood aspects of modeling flocculation. We use three-dimensional positional data of Klebsiella pneumoniae bacterial flocs in suspension and the knowledge of hydrodynamic properties of a laminar flow field to construct a probability density function of floc volumes after a fragmentation event. We provide computational results which predict that the primary fragmentation mechanism for large flocs is erosion. The postfragmentation probability density function has a strong dependence on the size of the original floc and indicates that most fragmentation events result in clumps of one to three bacteria eroding from the original floc. We also provide numerical evidence that exhaustive fragmentation yields a limiting density inconsistent with the log-normal density predicted in the literature, most likely due to the heterogeneous nature of K. pneumoniae flocs. To support our conclusions, artificial flocs were generated and display similar postfragmentation density and exhaustive fragmentation.

  12. Bat aggregation mediates the functional structure of ant assemblages.

    PubMed

    Dejean, Alain; Groc, Sarah; Hérault, Bruno; Rodriguez-Pérez, Héctor; Touchard, Axel; Céréghino, Régis; Delabie, Jacques H C; Corbara, Bruno

    2015-10-01

    In the Guianese rainforest, we examined the impact of the presence of guano in and around a bat roosting site (a cave). We used ant communities as an indicator to evaluate this impact because they occupy a central place in the functioning of tropical rainforest ecosystems and they play different roles in the food web as they can be herbivores, generalists, scavengers or predators. The ant species richness around the cave did not differ from a control sample situated 500m away. Yet, the comparison of functional groups resulted in significantly greater numbers of detritivorous fungus-growing and predatory ant colonies around the cave compared to the control, the contrary being true for nectar and honeydew feeders. The role of bats, through their guano, was shown using stable isotope analyses as we noted significantly greater δ(15)N values for the ant species captured in and around the cave compared to controls.

  13. Inhibition of IAPP Aggregation and Toxicity by Natural Products and Derivatives

    PubMed Central

    Pithadia, Amit; Brender, Jeffrey R.; Fierke, Carol A.; Ramamoorthy, Ayyalusamy

    2016-01-01

    Fibrillar aggregates of human islet amyloid polypeptide, hIAPP, a pathological feature seen in some diabetes patients, are a likely causative agent for pancreatic beta-cell toxicity, leading to a transition from a state of insulin resistance to type II diabetes through the loss of insulin producing beta-cells by hIAPP induced toxicity. Because of the probable link between hIAPP and the development of type II diabetes, there has been strong interest in developing reagents to study the aggregation of hIAPP and possible therapeutics to block its toxic effects. Natural products are a class of compounds with interesting pharmacological properties against amyloids which have made them interesting targets to study hIAPP. Specifically, the ability of polyphenolic natural products, EGCG, curcumin, and resveratrol, to modulate the aggregation of hIAPP is discussed. Furthermore, we have outlined possible mechanistic discoveries of the interaction of these small molecules with the peptide and how they may mitigate toxicity associated with peptide aggregation. These abundantly found agents have been long used to combat diseases for many years and may serve as useful templates toward developing therapeutics against hIAPP aggregation and toxicity. PMID:26649317

  14. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1995-01-01

    Part of the 1994 Industrial Minerals Review. The production, consumption, and applications of construction aggregates are reviewed. In 1994, the production of construction aggregates, which includes crushed stone and construction sand and gravel combined, increased 7.7 percent to 2.14 Gt compared with the previous year. These record production levels are mostly a result of funding for highway construction work provided by the Intermodal Surface Transportation Efficiency Act of 1991. Demand is expected to increase for construction aggregates in 1995.

  15. Regulation of synaptic Pumilio function by an aggregation-prone domain

    PubMed Central

    Salazar, Anna M.; Silverman, Edward J.; Menon, Kaushiki P.; Zinn, Kai

    2010-01-01

    We identified Pumilio (Pum), a Drosophila translational repressor, in a computational search for metazoan proteins whose activities might be regulated by assembly into ordered aggregates. The search algorithm was based on evolutionary sequence conservation patterns observed for yeast prion proteins, which contain aggregation-prone glutamine/asparagine (Q/N)-rich domains attached to functional domains of normal amino acid composition. We examined aggregation of Pum and its nematode ortholog PUF-9 by expression in yeast. A domain of Pum containing the Q/N-rich sequence, denoted as NQ1, the entire Pum N-terminus, and the complete PUF-9 protein localize to macroscopic aggregates (foci) in yeast. NQ1 and PUF-9 can generate the yeast Pin+ trait, which is transmitted by a heritable aggregate. NQ1 also assembles into amyloid fibrils in vitro. In Drosophila, Pum regulates postsynaptic translation at neuromuscular junctions (NMJs). To assess whether NQ1 affects synaptic Pum activity in vivo, we expressed it in muscles. We found that it negatively regulates endogenous Pum, producing gene dosage-dependent pum loss-of-function NMJ phenotypes. NQ1 coexpression also suppresses lethality and NMJ phenotypes caused by overexpression of Pum in muscles. The Q/N block of NQ1 is required for these phenotypic effects. Negative regulation of Pum by NQ1 might be explained by formation of inactive aggregates, but we have been unable to demonstrate that NQ1 aggregates in Drosophila. NQ1 could also regulate Pum by a “dominant-negative” effect, in which it would block Q/N-mediated interactions of Pum with itself or with cofactors required for translational repression. PMID:20071514

  16. Linking Microbial Community Structure to β-Glucosidic Function in Soil Aggregates

    SciTech Connect

    Bailey, Vanessa L.; Fansler, Sarah J.; Stegen, James C.; McCue, Lee Ann

    2013-10-01

    To link microbial community 16S structure to a measured function in a natural soil we have scaled both DNA and β-glucosidase assays down to a volume of soil that may approach a unique microbial community. β-glucosidase activity was assayed in 450 individual aggregates which were then sorted into classes of high or low activities, from which groups of 10 or 11 aggregates were identified and grouped for DNA extraction and pyrosequencing. Tandem assays of ATP were conducted for each aggregate in order to normalize these small groups of aggregates for biomass size. In spite of there being no significant differences in the richness or diversity of the microbial communities associated with high β-glucosidase activities compared with the communities associated with low β-glucosidase communities, several analyses of variance clearly show that the communities of these two groups differ. The separation of these groups is partially driven by the differential abundances of members of the Chitinophagaceae family. It may be that observed functional differences in otherwise similar soil aggregates can be largely attributed to differences in resource availability, rather than to presence or absence of particular taxonomic groups.

  17. Cost-Efficient and Multi-Functional Secure Aggregation in Large Scale Distributed Application

    PubMed Central

    Zhang, Ping; Li, Wenjun; Sun, Hua

    2016-01-01

    Secure aggregation is an essential component of modern distributed applications and data mining platforms. Aggregated statistical results are typically adopted in constructing a data cube for data analysis at multiple abstraction levels in data warehouse platforms. Generating different types of statistical results efficiently at the same time (or referred to as enabling multi-functional support) is a fundamental requirement in practice. However, most of the existing schemes support a very limited number of statistics. Securely obtaining typical statistical results simultaneously in the distribution system, without recovering the original data, is still an open problem. In this paper, we present SEDAR, which is a SEcure Data Aggregation scheme under the Range segmentation model. Range segmentation model is proposed to reduce the communication cost by capturing the data characteristics, and different range uses different aggregation strategy. For raw data in the dominant range, SEDAR encodes them into well defined vectors to provide value-preservation and order-preservation, and thus provides the basis for multi-functional aggregation. A homomorphic encryption scheme is used to achieve data privacy. We also present two enhanced versions. The first one is a Random based SEDAR (REDAR), and the second is a Compression based SEDAR (CEDAR). Both of them can significantly reduce communication cost with the trade-off lower security and lower accuracy, respectively. Experimental evaluations, based on six different scenes of real data, show that all of them have an excellent performance on cost and accuracy. PMID:27551747

  18. [Research advance in the function of quorum sensing in the biological aggregates].

    PubMed

    Dai, Xin; Zhou, Jia-Heng; Zhu, Liang; Xu, Xiang-Yang

    2014-04-01

    Quorum sensing is a microbial phenomenon that microorganisms use signal molecules to perceive environmental conditions and regulate specific gene expressions. As the communication function of quorum sensing is increasingly highlighted in the microbial field, researches on quorum sensing in the formation process of biological aggregates (biofilm and granules) attract wide attentions. The paper reviewed autoinducers (AI) classification and the corresponding regulation methods in quorum sensing, and provided an up-to-date account on research progress of AIs regulating biological aggregates formation and structural stability. New territories and future of quorum sensing were also outlined.

  19. Cyclodextrins 3-Functionalized with 8-Hydroxyquinolines: Copper-Binding Ability and Inhibition of Synuclein Aggregation.

    PubMed

    Oliveri, Valentina; Sgarlata, Carmelo; Vecchio, Graziella

    2016-09-06

    Neurodegenerative diseases such as Parkinson's and Alzheimer's diseases are multifactorial disorders related to protein aggregation, metal dyshomeostasis, and oxidative stress. To advance understanding in this area and to contribute to therapeutic development, many efforts have been directed at devising suitable agents that can target metal ions associated with relevant biomolecules such as α-synuclein. This paper presents a new cyclodextrin-8-hydroxyquinoline conjugate and discusses the properties of four cyclodextrins 3-functionalized with 8-hydroxyquinoline as copper(II) chelators and inhibitors of copper-induced synuclein aggregation. The encouraging results establish the potential of cyclodextrin-8-hydroxyquinoline conjugates as chelators for the control of copper toxicity.

  20. Production of chimeras by aggregation of embryonic stem cells with diploid or tetraploid mouse embryos.

    PubMed

    Eakin, Guy S; Hadjantonakis, Anna-Katerina

    2006-01-01

    The production of mouse chimeras is a common step in the establishment of genetically modified animal strains. Chimeras also provide a powerful experimental tool for following cell behavior during both prenatal and postnatal development. This protocol outlines a simple and economical technique for the production of large numbers of mouse chimeras using traditional diploid morula<-->diploid embryonic stem (ES) cell aggregations. Additional steps are included to describe the procedures necessary to produce specialized tetraploid chimeras using tetraploid morula<-->diploid ES cell aggregations. This increasingly popular form of chimera produces embryos of nearly complete ES cell derivation that can be used to speed transgenic production or ask developmental questions. Using this protocol, mouse chimeras can be generated and transferred to pseudopregnant surrogate mothers in a 5-d period.

  1. Process for producing an aggregate suitable for inclusion into a radiation shielding product

    DOEpatents

    Lessing, Paul A.; Kong, Peter C.

    2000-01-01

    The present invention is directed to methods for converting depleted uranium hexafluoride to a stable depleted uranium silicide in a one-step reaction. Uranium silicide provides a stable aggregate material that can be added to concrete to increase the density of the concrete and, consequently, shield gamma radiation. As used herein, the term "uranium silicide" is defined as a compound generically having the formula U.sub.x Si.sub.y, wherein the x represents the molecules of uranium and the y represent the molecules of silicon. In accordance with the present invention, uranium hexafluoride is converted to a uranium silicide by contacting the uranium hexafluoride with a silicon-containing material at a temperature in a range between about 1450.degree. C. and about 1750.degree. C. The stable depleted uranium silicide is included as an aggregate in a radiation shielding product, such as a concrete product.

  2. Differential inhibition of lipopolysaccharide-induced granulocyte aggregation and prostanoid production by emoxypin.

    PubMed

    Kubatiev, A; Turgiev, A; Smirnov, L; Pomoynetsky, V; Dumaev, K

    1990-01-01

    Emoxypin is known to be an effective membrane-stabilizing 3-oxy-pyridine derivative. We attempted to evaluate its influence on lipopolysaccharide (LPS)-induced granulocyte aggregation and prostanoid production. Granulocytes isolated from rabbit venous blood by dextran sedimentation and Pezcoll gradient centrifugation were stirred in the aggregometer cuvette with emoxypin (5mM), indomethacin (50 microM) or their solvents at 37 degrees C for 2 min. Then S. typhimurium LPS (200 micrograms/ml) was added and the aggregation was traced for 5 min. Thromboxane B2 (TxB2), prostaglandins (PG) E, F2 alpha and 13,14-dihydro-15-keto-PGF2 alpha were determined in supernatants radioimmunochemically. Indomethacin did not affect the pattern of aggregation, whereas emoxypin virtually precluded the response. Granulocytes incubated with LPS produced by the 15th sec and 5th min 1.3 and 2.5 times as much TxB2 respectively as did the intact cells (p less than 0.01). LPS had no effect on PGE production. Fifteen-sec contact of granulocytes with LPS had no significant influence on the formation of PGF2 alpha and its 13,14-dihydro-15-keto metabolite. The amount of PGF2 alpha released into the medium by the end of the 5th min of incubation with LPS was 1.5 times higher than in the control (p less than 0.05); the level of 13,14-dihydro-15-keto-PGF2 alpha was decreased 1.6 times (p less than 0.01). Emoxypin abolished totally LPS-induced TxB2 and PGF2 alpha production. We conclude that aggregation and eicosanoid production are independent manifestations of LPS-induced rabbit granulocyte activation.

  3. Recycling of quarry waste as part of sustainable aggregate production: Norwegian and Italian point of view

    NASA Astrophysics Data System (ADS)

    Antonella Dino, Giovanna; Willy Danielsen, Svein; Chiappino, Claudia; Primavori, Piero; Engelsen, Christian John

    2016-04-01

    Resource preservation is one of the main challenges in Europe, together with waste management and recycling; recently several researchers are interested in the recovering of critical raw materials and secondary raw materials from landfill. Aggregate supply, even if it is not "critical" sensus stricto (s.s.), is one of the European priorities (low value but high volume needs). On the other side, the management of quarry waste , mainly from dimension stones, but also as fines from aggregate crushing, is still a matter of concern. Such materials are managed in different ways both locally and nationwide, and often they are landfilled, because of an unclear legislation and a general lack of data. Most of time the local authorities adopt the maximum precaution principle or the enterprises find it little profitable to recover them, so that the sustainable recycling of such material is not valued. Several studies have shown, depending on the material specific characteristics, the viability of recycling quarry waste into new raw materials used in glass and ceramic industries, precast concrete production, infrastructures etc. (Loudes et al. 2012, Dino&Marian 2015, Bozzola et al 2012, Dino et al. 2012, etc.). Thus, aggregate production may be one of the profitable ways to use quarry waste and is falling under the priority of EU (aggregate supply). Positive economic and environmental effects are likely to be achieved by systematic recycling of quarry waste planned by industries (industrial planning) and public authorities (national and local planning of aggregate exploitation). Today, the recycling level varies to a great extent and systematic recovery is not common among European Countries. In Italy and Norway no significant incentives on recycling or systematic approaches for local aggregate exploitation exist. The environmental consequences can be overexploitation of the natural resources, land take for the landfills, environmental contamination and landscape alteration by

  4. Application of simulated annealing to solve multi-objectives for aggregate production planning

    NASA Astrophysics Data System (ADS)

    Atiya, Bayda; Bakheet, Abdul Jabbar Khudhur; Abbas, Iraq Tereq; Bakar, Mohd. Rizam Abu; Soon, Lee Lai; Monsi, Mansor Bin

    2016-06-01

    Aggregate production planning (APP) is one of the most significant and complicated problems in production planning and aim to set overall production levels for each product category to meet fluctuating or uncertain demand in future. and to set decision concerning hiring, firing, overtime, subcontract, carrying inventory level. In this paper, we present a simulated annealing (SA) for multi-objective linear programming to solve APP. SA is considered to be a good tool for imprecise optimization problems. The proposed model minimizes total production and workforce costs. In this study, the proposed SA is compared with particle swarm optimization (PSO). The results show that the proposed SA is effective in reducing total production costs and requires minimal time.

  5. Probability density function characterization for aggregated large-scale wind power based on Weibull mixtures

    DOE PAGES

    Gomez-Lazaro, Emilio; Bueso, Maria C.; Kessler, Mathieu; ...

    2016-02-02

    Here, the Weibull probability distribution has been widely applied to characterize wind speeds for wind energy resources. Wind power generation modeling is different, however, due in particular to power curve limitations, wind turbine control methods, and transmission system operation requirements. These differences are even greater for aggregated wind power generation in power systems with high wind penetration. Consequently, models based on one-Weibull component can provide poor characterizations for aggregated wind power generation. With this aim, the present paper focuses on discussing Weibull mixtures to characterize the probability density function (PDF) for aggregated wind power generation. PDFs of wind power datamore » are firstly classified attending to hourly and seasonal patterns. The selection of the number of components in the mixture is analyzed through two well-known different criteria: the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). Finally, the optimal number of Weibull components for maximum likelihood is explored for the defined patterns, including the estimated weight, scale, and shape parameters. Results show that multi-Weibull models are more suitable to characterize aggregated wind power data due to the impact of distributed generation, variety of wind speed values and wind power curtailment.« less

  6. Probability density function characterization for aggregated large-scale wind power based on Weibull mixtures

    SciTech Connect

    Gomez-Lazaro, Emilio; Bueso, Maria C.; Kessler, Mathieu; Martin-Martinez, Sergio; Zhang, Jie; Hodge, Bri -Mathias; Molina-Garcia, Angel

    2016-02-02

    Here, the Weibull probability distribution has been widely applied to characterize wind speeds for wind energy resources. Wind power generation modeling is different, however, due in particular to power curve limitations, wind turbine control methods, and transmission system operation requirements. These differences are even greater for aggregated wind power generation in power systems with high wind penetration. Consequently, models based on one-Weibull component can provide poor characterizations for aggregated wind power generation. With this aim, the present paper focuses on discussing Weibull mixtures to characterize the probability density function (PDF) for aggregated wind power generation. PDFs of wind power data are firstly classified attending to hourly and seasonal patterns. The selection of the number of components in the mixture is analyzed through two well-known different criteria: the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). Finally, the optimal number of Weibull components for maximum likelihood is explored for the defined patterns, including the estimated weight, scale, and shape parameters. Results show that multi-Weibull models are more suitable to characterize aggregated wind power data due to the impact of distributed generation, variety of wind speed values and wind power curtailment.

  7. SeqA protein aggregation is necessary for SeqA function.

    PubMed

    Lee, H; Kang, S; Bae, S H; Choi, B S; Hwang, D S

    2001-09-14

    The binding of SeqA protein to hemimethylated GATC sequences is important in the negative modulation of chromosomal initiation at oriC, and in the formation of SeqA foci necessary for Escherichia coli chromosome segregation. Using gel-filtration chromotography and glycerol gradient sedimentation, we demonstrate that SeqA exists as a homotetramer. SeqA tetramers are able to aggregate or multimerize in a reversible, concentration-dependent manner. Using a bacterial two-hybrid system, we demonstrate that the N-terminal region of SeqA, especifically the 9th amino acid residue, glutamic acid, is required for functional SeqA-SeqA interaction. Although the SeqA(E9K) mutant protein, containing lysine rather than glutamic acid at the 9th amino acid residue, exists as a tetramer, the mutant protein binds to hemimethylated DNA with altered binding patterns as compared with wild-type SeqA. Aggregates of SeqA(E9K) are defective in hemimethylated DNA binding. Here we demonstrate that proper interaction between SeqA tetramers is required for both hemimethylated DNA binding and formation of active aggregates. SeqA tetramers and aggregates might be involved in the formation of SeqA foci required for the segregation of chromosomal DNA as well as the regulation of chromosomal initiation.

  8. Cellular aggregate size as the critical factor for flavonoid production by suspension cultures of Saussurea medusa.

    PubMed

    Fu, Chun-xiang; Zhao, De-xiu; Huang, Yan; Ma, Feng-shan

    2005-01-01

    Three previously established cell lines (yellow, red and white) of Saussurea medusa were investigated for jaceosidin and hispidulin production. Maximum yields of the jaceosidin and hispidulin were obtained in the red cell line at 75+/-0.41 and 6.4+/-0.31 mg l-1. Production of jaceosidin and hispidulin correlated with the sizes of compact callus aggregates (CCA) and cellular viability. In the red cell line, the sizes of CCA were predominantly of 2-4 mm diameter and accounted for 64% biomass. This line had a sustained cell viability over 10 successive sub-cultures.

  9. Synthesis of the aggregation pheromone of the Colorado potato beetle from its degradation product.

    PubMed

    Wacławczyk-Biedroń, Weronika; Frąckowiak-Wojtasek, Bożena; Strub, Daniel; Rzechak, Magdalena; Wojtasek, Hubert

    2015-09-01

    Incubation of the Colorado potato beetle aggregation pheromone, (S)-1,3-dihydroxy-3,7-dimethyl-6-octen-2-one, with antennal or leg extracts from this beetle gave 6-methyl-5-hepten-2-one as the major product. This ketone was used as a substrate in a stereoselective synthesis of the pheromone. It was attached to the butanediacetal of glycolic acid with good stereoselectivity and the desired isomer was further enriched by purification of the product of this reaction on silica gel.

  10. Aggregate consumer exposure to UV filter ethylhexyl methoxycinnamate via personal care products.

    PubMed

    Manová, Eva; von Goetz, Natalie; Hungerbuehler, Konrad

    2015-01-01

    Ultraviolet (UV) filters are substances designed to protect our skin from UV-induced damage and can be found in many categories of personal care products (PCPs). The potential endocrine-disrupting effects attributed to UV filter ethylhexyl methoxycinnamate (EHMC) are being debated. We evaluated the aggregate exposure of the Swiss-German population (N=1196; ages ≤1-97years) to EHMC via the use of PCPs; thus we provide the first comprehensive information about the current EHMC exposure sources and aggregate exposure levels. In our probabilistic modeling method performed at an individual level, PCP use data obtained by a postal questionnaire were linked to concentration data on EHMC gained from chemical analyses of PCPs used by the questionnaire respondents. The modeled median and 99.9th percentile of the internal aggregate exposure for the general population were 0.012 and 0.873mgday(-1)kg(-1) and 0.008 and 0.122mgday(-1)kg(-1) for the summer/autumn and winter/spring period, respectively. The major contributors to internal aggregate exposure were sunscreen products in summer/autumn (females: 64%; males: 85%; children aged ≤12years 93%). In winter/spring, lip care dominated for females (30%) and sunscreen for males (38%) and children aged ≤12years (50%). Overall, the internal aggregate exposure estimates for the studied population are shown to be below the Derived No Effect Level (DNEL) for EHMC i.e., the level of exposure above which humans should not be exposed; however, when an intense short-term exposure via sunscreen is accounted for during a sunbathing day, at the high-end percentiles (99.9th) the predicted aggregate exposure exceeds the DNEL for thyroid-disrupting effects such as for children aged ≤4years, who might be particularly susceptible to endocrine disrupting events. It is nevertheless critical to acknowledge that quantitative data on transdermal penetration of EHMC from PCPs are currently insufficient. Since long-term effects of endocrine

  11. Microscopic analysis of alkali-aggregate reaction products in a 50-year-old concrete

    SciTech Connect

    Fernandes, Isabel . E-mail: ifernand@fc.up.pt; Noronha, Fernando . E-mail: fmnoronh@fc.up.pt; Teles, Madalena . E-mail: mteles@fe.up.pt

    2004-11-15

    Fifty-year-old concrete from a large dam was examined in the scope of an investigation program concerning the properties of granite as aggregate material for concrete. Site inspection, which was developed in order to detect possible signs of deterioration of the concrete, revealed the existence of efflorescence and exudations. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses were attempted to identify the composition of these materials and their morphology. From the analyses, it was concluded that some of the exudations were composed by alkali-silica gel. In these samples, an interesting behavior was observed in different moments after a 3-month interval. It was noticed that the initially noncrystalline alkali-silica gel transformed into sodium-rich needles and tablets after a few months kept in a desiccator in the laboratory. Therefore, it was concluded that the materials identified corresponded to different stages of evolution of an alkali-aggregate reaction product.

  12. Utilization of lignite power generation residues for the production of lightweight aggregates.

    PubMed

    Anagnostopoulos, Iason M; Stivanakis, Victor E

    2009-04-15

    A novel process is proposed for the utilization of lignite combustion solid residues in the production of inflammable lightweight aggregates (LWA). The process consists of two stages, pelletization and sintering, and carbon contained in BA was used as the process fuel. The main residues bottom ash (BA) and fly ash (FA) from Megalopolis power plant were characterized, mixed in different proportions and treated through pelletization and sintering process. Sintering benefits from combustion of BA carbon content and the product is a hardened porous cake. The energy required for achievement of high temperatures, in the range of 1250 degrees C, was offered by carbon combustion and CO(2) evolution is responsible for porous structure formation. Selected physical properties of sintered material relevant to use as lightweight aggregates were determined, including bulk density, porosity and water absorption. Bulk density varies from 0.83 to 0.91 g/cm(3), porosity varies from 60% to 64% and water absorption varies from 66% to 80%. LWA formed is used for the production of lightweight aggregate concrete (LWAC). Thermal conductivity coefficient varies from 0.25 to 0.37 W/mK (lower than maximum limit 0.43 W/mK) and compressive strength varies from 19 to 23 MPa (higher than minimum limit 17 MPa). The results indicate that sintering of lignite combustion residues is an efficient method of utilization of carbon containing BA and production of LWA for structural and insulating purposes. Carbon content of BA is a key factor in LWA production. Finally, this research work comprises the first proposed application for utilization of BA in Greece.

  13. Effects of heparin on platelet aggregation and release and thromboxane A2 production

    SciTech Connect

    Mohammad, S.F.; Anderson, W.H.; Smith, J.B.; Chuang, H.Y.; Mason, R.G.

    1981-08-01

    Heparin, when added to citrated platelet-rich plasma (PRP), caused potentiation of platelet aggregation and the release reaction induced by the aggregating agents adenosine diphosphate (ADP), arachidonic acid, collagen, and epinephrine. At low concentrations (4.7 x 10(-5) M) arachidonic acid failed to cause aggregation of platelets in citrated PRP. However, in the presence of heparin, the same concentration of arachidonic acid caused aggregation. Examination of PRP for the presence of thromboxane A2 (TxA2) by use of a bioassay revealed that heparin also stimulated release of TxA2. This finding indicated that platelets released more TxA2 when they were challenged by low concentrations of arachidonic acid in the presence of heparin than in its absence. Platelets were labeled with /sup 3/H-arachidonic acid and /sup 14/C-serotonin, and attempts were made to determine whether heparin stimulated the platelet release reaction first with subsequent increased production of TxA2, or alternatively, whether heparin stimulated TxA2 production first with subsequent enhancement of the release reaction. In view of the demonstrated simultaneous release of /sup 14/C-serotonin and /sup 3/H-arachidonic acid metabolites, it appeared that either release of /sup 14/C and /sup 3/H occurs concurrently or, even if one of these events is dependent on the other, both events take place in rapid succession. Timed sequential studies revealed that in the presence of arachidonic acid, the addition of heparin hastened the apparently simultaneous release of both /sup 14/C and /sup 3/H.

  14. TOPICAL REVIEW: Smart aggregates: multi-functional sensors for concrete structures—a tutorial and a review

    NASA Astrophysics Data System (ADS)

    Song, Gangbing; Gu, Haichang; Mo, Yi-Lung

    2008-06-01

    This paper summarizes the authors' recent pioneering research work in piezoceramic-based smart aggregates and their innovative applications in concrete civil structures. The basic operating principle of smart aggregates is first introduced. The proposed smart aggregate is formed by embedding a waterproof piezoelectric patch with lead wires into a small concrete block. The proposed smart aggregates are multi-functional and can perform three major tasks: early-age concrete strength monitoring, impact detection and structural health monitoring. The proposed smart aggregates are embedded into the desired location before the casting of the concrete structure. The concrete strength development is monitored by observing the high frequency harmonic wave response of the smart aggregate. Impact on the concrete structure is detected by observing the open-circuit voltage of the piezoceramic patch in the smart aggregate. For structural health monitoring purposes, a smart aggregate-based active sensing system is designed for the concrete structure. Wavelet packet analysis is used as a signal-processing tool to analyze the sensor signal. A damage index based on the wavelet packet analysis is used to determine the structural health status. To better describe the time-history and location information of damage, two types of damage index matrices are proposed: a sensor-history damage index matrix and an actuator-sensor damage index matrix. To demonstrate the multi-functionality of the proposed smart aggregates, different types of concrete structures have been used as test objects, including concrete bridge bent-caps, concrete cylinders and a concrete frame. Experimental results have verified the effectiveness and the multi-functionality of the proposed smart aggregates. The multi-functional smart aggregates have the potential to be applied to the comprehensive monitoring of concrete structures from their earliest stages and throughout their lifetime.

  15. A natural product inhibits the initiation of α-synuclein aggregation and suppresses its toxicity

    PubMed Central

    Perni, Michele; Maltsev, Alexander; Müller, Martin B. D.; Challa, Pavan K.; Kirkegaard, Julius B.; Cohen, Samuel I. A.; Cascella, Roberta; Chen, Serene W.; Limboker, Ryan; Sormanni, Pietro; Heller, Gabriella T.; Aprile, Francesco A.; Cremades, Nunilo; Cecchi, Cristina; Chiti, Fabrizio; Nollen, Ellen A. A.; Knowles, Tuomas P. J.; Vendruscolo, Michele; Bax, Adriaan; Zasloff, Michael; Dobson, Christopher M.

    2017-01-01

    The self-assembly of α-synuclein is closely associated with Parkinson’s disease and related syndromes. We show that squalamine, a natural product with known anticancer and antiviral activity, dramatically affects α-synuclein aggregation in vitro and in vivo. We elucidate the mechanism of action of squalamine by investigating its interaction with lipid vesicles, which are known to stimulate nucleation, and find that this compound displaces α-synuclein from the surfaces of such vesicles, thereby blocking the first steps in its aggregation process. We also show that squalamine almost completely suppresses the toxicity of α-synuclein oligomers in human neuroblastoma cells by inhibiting their interactions with lipid membranes. We further examine the effects of squalamine in a Caenorhabditis elegans strain overexpressing α-synuclein, observing a dramatic reduction of α-synuclein aggregation and an almost complete elimination of muscle paralysis. These findings suggest that squalamine could be a means of therapeutic intervention in Parkinson’s disease and related conditions. PMID:28096355

  16. Molten Globule of Hemoglobin Proceeds into Aggregates and Advanced Glycated End Products

    PubMed Central

    Iram, Afshin; Alam, Tauqeer; Khan, Javed M.; Khan, Taqi A.; Khan, Rizwan H.; Naeem, Aabgeena

    2013-01-01

    Conformational alterations of bovine hemoglobin (Hb) upon sequential addition of glyoxal over a range of 0–90% v/v were investigated. At 20% v/v glyoxal, molten globule (MG) state of Hb was observed by altered tryptophan fluorescence, high ANS binding, existence of intact heme, native-like secondary structure as depicted by far-UV circular dichroism (CD) and ATR-FTIR spectra as well as loss in tertiary structure as confirmed by near-UV CD spectra. In addition, size exclusion chromatography analysis depicted that MG state at 20% v/v glyoxal corresponded to expanded pre-dissociated dimers. Aggregates of Hb were detected at 70% v/v glyoxal. These aggregates of Hb had altered tryptophan environment, low ANS binding, exposed heme, increased β-sheet secondary structure, loss in tertiary structure, enhanced thioflavin T (ThT) fluorescence and red shifted Congo Red (CR) absorbance. On incubating Hb with 30% v/v glyoxal for 0–20 days, advanced glycation end products (AGEs) were detected on day 20. These AGEs were characterised by enhanced tryptophan fluorescence at 450 nm, exposure of heme, increase in intermolecular β-sheets, enhanced ThT fluorescence and red shift in CR absorbance. Comet assay revealed aggregates and AGEs to be genotoxic in nature. Scanning electron microscopy confirmed the amorphous structure of aggregates and branched fibrils of AGEs. The transformation of α-helix to β-sheet usually alters the normal protein to amyloidogenic resulting in a variety of protein conformational disorders such as diabetes, prion and Huntington's. PMID:23991043

  17. Strategies for the assessment of protein aggregates in pharmaceutical biotech product development.

    PubMed

    den Engelsman, John; Garidel, Patrick; Smulders, Ronald; Koll, Hans; Smith, Bryan; Bassarab, Stefan; Seidl, Andreas; Hainzl, Otmar; Jiskoot, Wim

    2011-04-01

    Within the European Immunogenicity Platform (EIP) ( http://www.e-i-p.eu ), the Protein Characterization Subcommittee (EIP-PCS) has been established to discuss and exchange experience of protein characterization in relation to unwanted immunogenicity. In this commentary, we, as representatives of EIP-PCS, review the current state of methods for analysis of protein aggregates. Moreover, we elaborate on why these methods should be used during product development and make recommendations to the biotech community with regard to strategies for their application during the development of protein therapeutics.

  18. Characterizing harmful advanced glycation end-products (AGEs) and ribosylated aggregates of yellow mustard seed phytocystatin: Effects of different monosaccharides

    NASA Astrophysics Data System (ADS)

    Ahmed, Azaj; Shamsi, Anas; Bano, Bilqees

    2017-01-01

    Advanced glycation end products (AGEs) are at the core of variety of diseases ranging from diabetes to renal failure and hence gaining wide consideration. This study was aimed at characterizing the AGEs of phytocystatin isolated from mustard seeds (YMP) when incubated with different monosaccharides (glucose, ribose and mannose) using fluorescence, ultraviolet, circular dichroism (CD) spectroscopy and microscopy. Ribose was found to be the most potent glycating agent as evident by AGEs specific fluorescence and absorbance. YMP exists as a molten globule like structure on day 24 as depicted by high ANS fluorescence and altered intrinsic fluorescence. Glycated YMP as AGEs and ribose induced aggregates were observed at day 28 and 32 respectively. In our study we have also examined the anti-aggregative potential of polyphenol, resveratrol. Our results suggested the anti-aggregative behavior of resveratrol as it prevented the in vitro aggregation of YMP, although further studies are required to decode the mechanism by which resveratrol prevents the aggregation.

  19. Measuring Social Returns to Higher Education Investments in Hong Kong: Production Function Approach.

    ERIC Educational Resources Information Center

    Voon, Jan P.

    2001-01-01

    Uses a growth model involving an aggregate production function to measure social benefits from human capital improvements due to investments in Hong Kong higher education. Returns calculated using the production-function approach are significantly higher than those derived from the wage-increment method. Returns declined during the past 10 years.…

  20. Bacteriochlorophyll aggregates self-assembled on functionalized gold nanorod cores as mimics of photosynthetic chlorosomal antennae: a single molecule study.

    PubMed

    Furumaki, Shu; Vacha, Frantisek; Hirata, Shuzo; Vacha, Martin

    2014-03-25

    We prepare artificial aggregates that mimic the structure and function of natural chlorosomal light harvesting complexes of green photosynthetic bacteria. Gold nanorods functionalized with hydroxyl groups and immobilized on a substrate serve as cores for the growth of bacteriochlorophyll (BChl) aggregates from a buffer solution. The BChl pigments form large self-assembled aggregate particles with sizes more than twice that of natural chlorosomes. The size is controllable by the aggregation time. The aggregates are characterized on a single-particle level by atomic force microscopy, electron microscopy, and single-molecule spectroscopy. The absorption and fluorescence spectral properties which reflect the molecular level arrangement of the BChl aggregates closely resemble those of the natural chlorosomes of the photosynthetic bacterium Chlorobaculum tepidum. On the other hand, the results of linear dichroism and circular dichroism are different from those of the chlorosomes and indicate a different mesoscopic structure for the artificial aggregates. These results emphasize the structural role played by the baseplate pigment-protein complex in natural chlorosomes.

  1. Extending Ripley’s K-Function to Quantify Aggregation in 2-D Grayscale Images

    PubMed Central

    Amgad, Mohamed; Itoh, Anri; Tsui, Marco Man Kin

    2015-01-01

    In this work, we describe the extension of Ripley’s K-function to allow for overlapping events at very high event densities. We show that problematic edge effects introduce significant bias to the function at very high densities and small radii, and propose a simple correction method that successfully restores the function’s centralization. Using simulations of homogeneous Poisson distributions of events, as well as simulations of event clustering under different conditions, we investigate various aspects of the function, including its shape-dependence and correspondence between true cluster radius and radius at which the K-function is maximized. Furthermore, we validate the utility of the function in quantifying clustering in 2-D grayscale images using three modalities: (i) Simulations of particle clustering; (ii) Experimental co-expression of soluble and diffuse protein at varying ratios; (iii) Quantifying chromatin clustering in the nuclei of wt and crwn1 crwn2 mutant Arabidopsis plant cells, using a previously-published image dataset. Overall, our work shows that Ripley’s K-function is a valid abstract statistical measure whose utility extends beyond the quantification of clustering of non-overlapping events. Potential benefits of this work include the quantification of protein and chromatin aggregation in fluorescent microscopic images. Furthermore, this function has the potential to become one of various abstract texture descriptors that are utilized in computer-assisted diagnostics in anatomic pathology and diagnostic radiology. PMID:26636680

  2. The application of sewage sludge as an expanding agent in the production of lightweight expanded clay aggregate mass.

    PubMed

    Latosińska, J; Zygadło, M

    2011-10-01

    Sewage sludge can be used as an expanding agent in the production of lightweight expanded clay aggregate (LECA) mass. The addition of sewage sludge increases the total porosity and decreases the bulk density of a sinter. The addition of sewage sludge to a raw material used in the production of LECA enabled a decrease in the burning temperature for the maintained operational parameters of a lightweight aggregate. The optimum content of sewage sludge added to a raw material used in LECA production was 5% to 15% of dry mass. The addition of sewage sludge in an amount of 5% and 10% caused an increase in closed porosity.

  3. The Optimum Production Method for Quality Improvement of Recycled Aggregates Using Sulfuric Acid and the Abrasion Method.

    PubMed

    Kim, Haseog; Park, Sangki; Kim, Hayong

    2016-07-29

    There has been increased deconstruction and demolition of reinforced concrete structures due to the aging of the structures and redevelopment of urban areas resulting in the generation of massive amounts of construction. The production volume of waste concrete is projected to increase rapidly over 100 million tons by 2020. However, due to the high cement paste content, recycled aggregates have low density and high absorption ratio. They are mostly used for land reclamation purposes with low added value instead of multiple approaches. This study was performed to determine an effective method to remove cement paste from recycled aggregates by using the abrasion and substituting the process water with acidic water. The aim of this study is to analyze the quality of the recycled fine aggregates produced by a complex method and investigate the optimum manufacturing conditions for recycled fine aggregates based on the design of experiment. The experimental parameters considered were water ratio, coarse aggregate ratio, and abrasion time and, as a result of the experiment, data concerning the properties of recycled sand were obtained. It was found that high-quality recycled fine aggregates can be obtained with 8.57 min of abrasion-crusher time and a recycled coarse aggregate ratio of over 1.5.

  4. The Optimum Production Method for Quality Improvement of Recycled Aggregates Using Sulfuric Acid and the Abrasion Method

    PubMed Central

    Kim, Haseog; Park, Sangki; Kim, Hayong

    2016-01-01

    There has been increased deconstruction and demolition of reinforced concrete structures due to the aging of the structures and redevelopment of urban areas resulting in the generation of massive amounts of construction. The production volume of waste concrete is projected to increase rapidly over 100 million tons by 2020. However, due to the high cement paste content, recycled aggregates have low density and high absorption ratio. They are mostly used for land reclamation purposes with low added value instead of multiple approaches. This study was performed to determine an effective method to remove cement paste from recycled aggregates by using the abrasion and substituting the process water with acidic water. The aim of this study is to analyze the quality of the recycled fine aggregates produced by a complex method and investigate the optimum manufacturing conditions for recycled fine aggregates based on the design of experiment. The experimental parameters considered were water ratio, coarse aggregate ratio, and abrasion time and, as a result of the experiment, data concerning the properties of recycled sand were obtained. It was found that high-quality recycled fine aggregates can be obtained with 8.57 min of abrasion-crusher time and a recycled coarse aggregate ratio of over 1.5. PMID:27483298

  5. Molecular mechanisms underlying the enhanced functions of three-dimensional hepatocyte aggregates

    PubMed Central

    Chang, Tammy T.; Hughes-Fulford, Millie

    2014-01-01

    Three-dimensional (3D) culture of hepatocytes leads to improved and prolonged synthetic and metabolic functions, but the underlying molecular mechanisms are unknown. In order to investigate the role of 3D cell-cell interactions in maintaining hepatocyte differentiated functions ex vivo, primary mouse hepatocytes were cultured either as monolayers on tissue culture dishes (TCD) or as 3D aggregates in rotating wall vessel (RWV) bioreactors. Global gene expression analyses revealed that genes upregulated in 3D culture were distinct from those upregulated during liver development and liver regeneration. Instead, they represented a diverse array of hepatocyte-specific functional genes with significant over-representation of hepatocyte nuclear factor 4α (Hnf4a) binding sites in their promoters. Expression of Hnf4a and many of its downstream target genes were significantly increased in RWV cultures as compared to TCD. Conversely, there was concomitant suppression of mesenchymal and cytoskeletal genes in RWV cultures that were induced in TCDs. These findings illustrate the importance of 3D cell-cell interactions in maintaining fundamental molecular pathways of hepatocyte function and serve as a basis for rational design of biomaterials that aim to optimize hepatocyte functions ex vivo for biomedical applications. PMID:24332390

  6. Production Function Geometry with "Knightian" Total Product

    ERIC Educational Resources Information Center

    Truett, Dale B.; Truett, Lila J.

    2007-01-01

    Authors of principles and price theory textbooks generally illustrate short-run production using a total product curve that displays first increasing and then diminishing marginal returns to employment of the variable input(s). Although it seems reasonable that a temporary range of increasing returns to variable inputs will likely occur as…

  7. Marine Data Management within the EMODNet Chemistry project: data aggregation, quality control and products preparation.

    NASA Astrophysics Data System (ADS)

    Iona, Athanasia Sissy; Karagevrekis, Pelopidas; Balopoulou, Stavroula; Giorgetti, Alessandra; Schaap, Dick

    2015-04-01

    The European Commission in response to the EU Green Paper for an integrated maritime policy has initiated the European Marine Observation and Data Network (EMODnet) to improve Europe's marine data infrastructure, increase the availability of high quality data and assemble them under a common framework. In 2009, six service contracts were launched by DG-MARE for creating the pilot components of the network and setting up thematic web portals covering selected marine basins. In 2012, a second call was opened by DG-MARE to continue the further expand the pilot portals in terms of geographical coverage and range of products and concluded in seven service contracts for: bathymetry, geology, physical habitats, chemistry, biology, physics and human activities. Supporting activities are also foreseen to examine how the portals meet the needs of users from industry, public authorities and scientists, to identify data gaps and arguments why these gaps should be filled in future monitoring. The second EMODNet Chemistry proposal has been prepared and submitted by the SeaDataNet consortium which is the leading data management network in Europe, covering all sea basins in European waters with data input from almost all coastal states. It is the same consortium that had been awarded the first call for the preparatory actions and has been extended with new partners. EMODnet Chemistry (www.emodnet-chemistry.eu/) is focusing on measurement data for groups of chemical variables in water, sediments and biota with relevance to the Marine Strategy Framework Directive. Five regional groups corresponding to the five MSFD regions are performing quality control and aggregation on the data gathered from many distributed data providers of the SeaDataNet infrastructure in order to generate regional harmonized, aggregated and validated data sets for selected groups of chemicals variables. Then these data sets are used to prepare interpolated maps of chemical variables per region over time and

  8. Effect of carbon sources on the aggregation of photo fermentative bacteria induced by L-cysteine for enhancing hydrogen production.

    PubMed

    Xie, Guo-Jun; Liu, Bing-Feng; Ding, Jie; Wang, Qilin; Ma, Chao; Zhou, Xu; Ren, Nan-Qi

    2016-12-01

    Poor flocculation of photo fermentative bacteria resulting in continuous biomass washout from photobioreactor is a critical challenge to achieve rapid and stable hydrogen production. In this work, the aggregation of Rhodopseudomonas faecalis RLD-53 was successfully developed in a photobioreactor and the effects of different carbon sources on hydrogen production and aggregation ability were investigated. Extracellular polymeric substances (EPS) production by R. faecalis RLD-53 cultivated using different carbon sources were stimulated by addition of L-cysteine. The absolute ζ potentials of R. faecalis RLD-53 were considerably decreased with addition of L-cysteine, and aggregation barriers based on DLVO dropped to 15-43 % of that in control groups. Thus, R. faecalis RLD-53 flocculated effectively, and aggregation abilities of strain RLD-53 cultivated with acetate, propionate, lactate and malate reached 29.35, 32.34, 26.07 and 24.86 %, respectively. In the continuous test, hydrogen-producing activity was also promoted and reached 2.45 mol H2/mol lactate, 3.87 mol H2/mol propionate and 5.10 mol H2/mol malate, respectively. Therefore, the aggregation of R. faecalis RLD-53 induced by L-cysteine is independent on the substrate types, which ensures the wide application of this technology to enhance hydrogen recovery from wastewater dominated by different organic substrates.

  9. The production of synthetic aggregate from a quarry waste using an innovative style rotary kiln.

    PubMed

    Wainwright, R J; Cresswell, D J F; van der Sloot, H A

    2002-06-01

    The large volumes of wastes generated by industrialised society has led to efforts to find practical uses for these wastes, whilst also offsetting the consumption of natural resources. This paper describes the use of an innovative rotary kiln to produce synthetic aggregates from a variety of waste streams. The main waste used was a quarry fines which was blended with either paper sludge, clay, or a dredged harbour sediment. The different combinations were extruded and fired in the kiln to produce a material suitable for natural aggregate replacement. Two of the synthetic aggregates produced were tested by incorporation in to concrete as coarse aggregate replacement. The concrete 28-day compressive strengths achieved were above 40 N mm(-2) and compared favourably with control concretes made with natural aggregates and a commercially available lightweight aggregate (Lytag). Leaching tests have also been carried out to assess the potential environmental impact of utilisation. Although not finalised, these tests have also given favourable results.

  10. Phosphorus content as a function of soil aggregate size and paddy cultivation in highly weathered soils.

    PubMed

    Li, Baozhen; Ge, Tida; Xiao, Heai; Zhu, Zhenke; Li, Yong; Shibistova, Olga; Liu, Shoulong; Wu, Jinshui; Inubushi, Kazuyuki; Guggenberger, Georg

    2016-04-01

    Red soils are the major land resource in subtropical and tropical areas and are characterized by low phosphorus (P) availability. To assess the availability of P for plants and the potential stability of P in soil, two pairs of subtropical red soil samples from a paddy field and an adjacent uncultivated upland were collected from Hunan Province, China. Analysis of total P and Olsen P and sequential extraction was used to determine the inorganic and organic P fractions in different aggregate size classes. Our results showed that the soil under paddy cultivation had lower proportions of small aggregates and higher proportions of large aggregates than those from the uncultivated upland soil. The portion of >2-mm-sized aggregates increased by 31 and 20 % at Taoyuan and Guiyang, respectively. The total P and Olsen P contents were 50-150 and 50-300 % higher, respectively, in the paddy soil than those in the upland soil. Higher inorganic and organic P fractions tended to be enriched in both the smallest and largest aggregate size classes compared to the middle size class (0.02-0.2 mm). Furthermore, the proportion of P fractions was higher in smaller aggregate sizes (<2 mm) than in the higher aggregate sizes (>2 mm). In conclusion, soils under paddy cultivation displayed improved soil aggregate structure, altered distribution patterns of P fractions in different aggregate size classes, and to some extent had enhanced labile P pools.

  11. Morphology, ultrastructure and functional role of antennal sensilla in off-host aggregation by the bed bug, Cimex lectularius.

    PubMed

    Olson, Joelle F; Moon, Roger D; Kells, Stephen A; Mesce, Karen A

    2014-03-01

    After blood feeding on a host, bed bugs, Cimex lectularius, assemble in aggregation sites away from the host. Off-host aggregation is mediated by a combination of mechanical and chemical stimuli associated with bug feces. Partial antennectomies indicated removal of flagellomeres did not affect aggregation, but removal of the whole pedicel or its distal half significantly reduced (P < 0.01) aggregation, suggesting that sensilla related to off-host aggregation occur on the distal half of the pedicel. Scanning electron microscopy (SEM) revealed that serrated hairs were distributed throughout the pedicel, but newly described smooth hairs were present mainly on the distal half, and a distinct patch of grooved pegs, smooth pegs and immersed cones was present on the posterior edge of the distal half of the pedicel in adults, but not in nymphs. Numbers of different types of sensilla increased significantly during metamorphosis from first instar to adult (P < 0.05), but were similar between genders (P = 0.11) and between females from a laboratory and field strain of bugs (P = 0.19). Transmission electron microscopy (TEM) revealed that cuticular pores were present in the two types of pegs, indicating that the pegs have an olfactory function. The smooth hairs resembled gustatory sensilla previously described in Cimex hemipterus F. The existence of both olfactory and gustatory sensilla on the distal half of the pedicel suggests those sensilla may be the sensory basis of off-host aggregation behavior.

  12. Use of an aggregate exposure model to estimate consumer exposure to fragrance ingredients in personal care and cosmetic products.

    PubMed

    Safford, B; Api, A M; Barratt, C; Comiskey, D; Daly, E J; Ellis, G; McNamara, C; O'Mahony, C; Robison, S; Smith, B; Thomas, R; Tozer, S

    2015-08-01

    Ensuring the toxicological safety of fragrance ingredients used in personal care and cosmetic products is essential in product development and design, as well as in the regulatory compliance of the products. This requires an accurate estimation of consumer exposure which, in turn, requires an understanding of consumer habits and use of products. Where ingredients are used in multiple product types, it is important to take account of aggregate exposure in consumers using these products. This publication investigates the use of a newly developed probabilistic model, the Creme RIFM model, to estimate aggregate exposure to fragrance ingredients using the example of 2-phenylethanol (PEA). The output shown demonstrates the utility of the model in determining systemic and dermal exposure to fragrances from individual products, and aggregate exposure. The model provides valuable information not only for risk assessment, but also for risk management. It should be noted that data on the concentrations of PEA in products used in this article were obtained from limited sources and not the standard, industry wide surveys typically employed by the fragrance industry and are thus presented here to illustrate the output and utility of the newly developed model. They should not be considered an accurate representation of actual exposure to PEA.

  13. Construction aggregates

    USGS Publications Warehouse

    Nelson, T.I.; Bolen, W.P.

    2007-01-01

    Construction aggregates, primarily stone, sand and gravel, are recovered from widespread naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size and sold loose or combined with portland cement or asphaltic cement to make concrete products to build roads, houses, buildings, and other structures. Much smaller quantities are used in agriculture, cement manufacture, chemical and metallurgical processes, glass production and many other products.

  14. Urban Scaling and the Production Function for Cities

    PubMed Central

    Lobo, José; Bettencourt, Luís M. A.; Strumsky, Deborah; West, Geoffrey B.

    2013-01-01

    The factors that account for the differences in the economic productivity of urban areas have remained difficult to measure and identify unambiguously. Here we show that a microscopic derivation of urban scaling relations for economic quantities vs. population, obtained from the consideration of social and infrastructural properties common to all cities, implies an effective model of economic output in the form of a Cobb-Douglas type production function. As a result we derive a new expression for the Total Factor Productivity (TFP) of urban areas, which is the standard measure of economic productivity per unit of aggregate production factors (labor and capital). Using these results we empirically demonstrate that there is a systematic dependence of urban productivity on city population size, resulting from the mismatch between the size dependence of wages and labor, so that in contemporary US cities productivity increases by about 11% with each doubling of their population. Moreover, deviations from the average scale dependence of economic output, capturing the effect of local factors, including history and other local contingencies, also manifest surprising regularities. Although, productivity is maximized by the combination of high wages and low labor input, high productivity cities show invariably high wages and high levels of employment relative to their size expectation. Conversely, low productivity cities show both low wages and employment. These results shed new light on the microscopic processes that underlie urban economic productivity, explain the emergence of effective aggregate urban economic output models in terms of labor and capital inputs and may inform the development of economic theory related to growth. PMID:23544042

  15. Evaluation of clay aggregate biotrickling filters for treatment of gaseous emissions from intensive pig production.

    PubMed

    Liu, Dezhao; Løkke, Mette Marie; Riis, Anders Leegaard; Mortensen, Knud; Feilberg, Anders

    2014-04-01

    Treatment of ventilation air from livestock production by biological airfiltration has emerged as a cost-effective technology for reduction of emissions of odorants and ammonia. Volatile sulfur compounds from livestock production include H2S and methanethiol, which have been identified as potentially important odorants that are not removed sufficiently by biological air filters. Light-expanded clay aggregates (Leca(®)) is a biotrickling filter material that contains iron oxides, which can oxidize H2S and methanethiol, and thus potentially may help to remove these two compounds in biological air filters. This study used on-line PTR-MS measurements to investigate the performances of two Leca(®) biotrickling filters (abraded Leca(®) filter and untreated Leca(®) filter) for removal of odorants and ammonia emitted from an experimental pig house. The results indicated that the abraded Leca(®) filter had a similar or slightly better capability for removing odorants than the untreated Leca(®) filter. This may be due to the enlargement of the surface area by the friction process. The volatile sulfur compounds, however, were not removed efficiently by either of the two Leca(®) filters. Kinetic analysis of a ventilation controlled experiment during the first period indicated that Grau second-order kinetics could be applied to analyze the removal of sulfur compounds and other odorants, whereas the Stover-Kincannon model could only be applied to analyze the removal of odorants other than sulfur compounds, partly due to the limitation of mass transfer of these compounds in the biotrickling filters. In the last measurement period, a production of dimethyl disulfide and dimethyltrisulfide coinciding with strongly enhanced removal of methanethiol was observed for the untreated filter. This was assumed to be enhanced by an incidence of low local air velocity in the filter and indicated involvement of iron-catalyzed reactions in the removal of sulfur compounds.

  16. Fractal aggregates in Titan's atmosphere

    NASA Astrophysics Data System (ADS)

    Cabane, M.; Rannou, P.; Chassefiere, E.; Israel, G.

    1993-04-01

    The cluster structure of Titan's atmosphere was modeled by using an Eulerian microphysical model with the specific formulation of microphysical laws applying to fractal particles. The growth of aggregates in the settling phase was treated by introducing the fractal dimension as a parameter of the model. The model was used to obtain a vertical distribution of size and number density of the aggregates for different production altitudes. Results confirm previous estimates of the formation altitude of photochemical aerosols. The vertical profile of the effective radius of aggregates was calculated as a function of the visible optical depth.

  17. The applicability of different waste materials for the production of lightweight aggregates.

    PubMed

    Ducman, V; Mirtic, B

    2009-08-01

    The applicability of different waste materials for the production of lightweight aggregates has been studied. The following waste materials were investigated: silica sludge, superfluous clay in the quarry, waste glass, and residue from the polishing process of different types of stone. SiC and MnO(2) were selected as foaming agents. Feldspar containing minerals and scrap glass were added in order to lower the softening point of the waste materials. The granules were prepared by mixing together finely ground waste with one or both of the selected foaming agents. The granules were then fired at different temperatures above the softening point of the glassy phase within the temperature range from 1150 to 1220 degrees C, where the foaming agent degasses, and the resulting gasses remain trapped in the glassy structure. The foaming process was observed by hot-stage microscopy. The properties of the so-obtained granules, such as their apparent density and compressive strength, were determined, and their microstructures were evaluating using SEM and polarizing microscopy. With the addition to clay of polishing residue from granite-like rocks, after firing at 1220 degrees C homogeneously porous granules with a density down to 0.42 g/cm(3) were obtained, whereas with the addition to waste silica sludge of polishing residue from granite-like rocks and waste glass with a foaming agent, after firing at 1220 degrees C densities from 0.57 to 0.82 g/cm(3) were obtained.

  18. Improving functional value of meat products.

    PubMed

    Zhang, Wangang; Xiao, Shan; Samaraweera, Himali; Lee, Eun Joo; Ahn, Dong U

    2010-09-01

    In recent years, much attention has been paid to develop meat and meat products with physiological functions to promote health conditions and prevent the risk of diseases. This review focuses on strategies to improve the functional value of meat and meat products. Value improvement can be realized by adding functional compounds including conjugated linoneleic acid, vitamin E, n3 fatty acids and selenium in animal diets to improve animal production, carcass composition and fresh meat quality. In addition, functional ingredients such as vegetable proteins, dietary fibers, herbs and spices, and lactic acid bacteria can be directly incorporated into meat products during processing to improve their functional value for consumers. Functional compounds, especially peptides, can also be generated from meat and meat products during processing such as fermentation, curing and aging, and enzymatic hydrolysis. This review further discusses the current status, consumer acceptance, and market for functional foods from the global viewpoints. Future prospects for functional meat and meat products are also discussed.

  19. Protein engineering to stabilize soluble amyloid β-protein aggregates for structural and functional studies.

    PubMed

    Härd, Torleif

    2011-10-01

    The molecular biology underlying protein aggregation and neuronal death in Alzheimer's disease is not yet completely understood, but small soluble nonamyloid aggregates of the amyloid β-protein (Aβ) have been shown to play a fundamental neurotoxic role. The composition and biological action of such aggregates, known as oligomers and protofibrils, are therefore areas of intense study. However, research is complicated by the multitude of different interconverting aggregates that Aβ can form in vitro and in vivo, and by the inhomogeneity and instability of in vitro preparations. Here we review recent studies in which protein engineering, and in particular disulfide engineering, has been applied to stabilize different Aβ aggregates. For example, several techniques now exist to obtain stable and neurotoxic protofibrillar forms of Aβ, and engineered Aβ dimers, or larger aggregates formed by these, have been shown to specifically induce neuronal damage in a way that mimics Alzheimer's disease pathology. Disulfide engineering has also revealed structural properties of neurotoxic aggregates, for instance that Aβ in protofibrils and globular oligomers adopts a β-hairpin conformation that is similar to, but topologically distinct from, the conformation of Aβ in mature amyloid fibrils. Protein engineering is therefore a workable strategy to address many of the outstanding questions relating to the structure, interconversion and biological effects of oligomers and protofibrils of Aβ.

  20. Surface functionalization for tailoring the aggregation and magnetic behaviour of silica-coated iron oxide nanostructures

    NASA Astrophysics Data System (ADS)

    Roca, A. G.; Carmona, D.; Miguel-Sancho, N.; Bomatí-Miguel, O.; Balas, F.; Piquer, C.; Santamaría, J.

    2012-04-01

    We report here a detailed structural and magnetic study of different silica nanocapsules containing uniform and highly crystalline maghemite nanoparticles. The magnetic phase consists of 5 nm triethylene glycol (TREG)- or dimercaptosuccinic acid (DMSA)-coated maghemite particles. TREG-coated nanoparticles were synthesized by thermal decomposition. In a second step, TREG ligands were exchanged by DMSA. After the ligand exchange, the ζ potential of the particles changed from - 10 to - 40 mV, whereas the hydrodynamic size remained constant at around 15 nm. Particles coated by TREG and DMSA were encapsulated in silica following a sol-gel procedure. The encapsulation of TREG-coated nanoparticles led to large magnetic aggregates, which were embedded in coalesced silica structures. However, DMSA-coated nanoparticles led to small magnetic clusters inserted in silica spheres of around 100 nm. The final nanostructures can be described as the result of several competing factors at play. Magnetic measurements indicate that in the TREG-coated nanoparticles the interparticle magnetic interaction scenario has not dramatically changed after the silica encapsulation, whereas in the DMSA-coated nanoparticles, the magnetic interactions were screened due to the function of the silica template. Moreover, the analysis of the AC susceptibility suggests that our systems essentially behave as cluster spin glass systems.

  1. Vanillin restrains non-enzymatic glycation and aggregation of albumin by chemical chaperone like function.

    PubMed

    Awasthi, Saurabh; Saraswathi, N T

    2016-06-01

    Vanillin a major component of vanilla bean extract is commonly used a natural flavoring agent. Glycation is known to induce aggregation and fibrillation of globular proteins such as albumin, hemoglobin. Here we report the inhibitory potential of vanillin toward early and advanced glycation modification and amyloid like aggregation of albumin based on the determination of both early and advanced glycation and conformational changes in albumin using circular dichroism. Inhibition of aggregation and fibrillation of albumin was determined based on amyloid specific dyes i.e., Congo red and Thioflavin T and microscopic imaging. It was evident that vanillin restrains glycation of albumin and exhibits protective effect toward its native conformation.

  2. Aggregation of hsp70 and hsc70 in vivo is distinct and temperature-dependent and their chaperone function is directly related to non-aggregated forms.

    PubMed

    Angelidis, C E; Lazaridis, I; Pagoulatos, G N

    1999-01-01

    We used non-denaturing gradient analysis of cell extracts before and after heat treatment of the cells and showed that hsp70 and hsc70 aggregate in vivo in a temperature-dependent fashion. Their aggregation profiles were found to be clearly distinguishable and sensitive to ATP depletion. Pore exclusion limit electrophoresis showed that these two proteins are mainly found in autoaggregated forms including dimers, trimers and oligomers. The addition of denatured luciferase to the cell extracts reversed the aggregation of both proteins towards their non-aggregated forms. Immunoprecipitation and Western-blot analysis showed that the non-aggregated form is the only one bound to denatured luciferase. Our results suggest that aggregated hsp70 and hsc70 represent predominantly self-associated molecules unable to exert chaperone activity. The cochaperone hsp40 was also found to be aggregated and, on addition of denatured luciferase, its aggregation was reversed to a non-aggregated state. Immunoprecipitation analysis indicated that hsp40 forms a complex with the non-aggregated form of hsc70 and denatured luciferase. These results confirm previous in vitro studies and support the suggestion that in vivo cytosolic hsp70 and hsc70 exist mainly in an oligomer-monomer equilibrium which is dependent on the environmental temperature, the levels of ATP and the presence of denatured proteins.

  3. Key attributes of ecological production functions

    EPA Science Inventory

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem service (ES) production. Though essential for improving environmental management, relatively little attention has been directed toward the characteristics of EPFs. EPFs may be d...

  4. Functional and Structural Effects of Amyloid-β Aggregate on Xenopus laevis Oocytes

    PubMed Central

    Parodi, Jorge; la Paz, Lenin Ochoa-de; Miledi, Ricardo; Martínez-Torres, Ataúlfo

    2012-01-01

    Xenopus laevis oocytes exposed to amyloid-β aggregate generated oscillatory electric activity (blips) that was recorded by two-microelectrode voltage-clamp. The cells exhibited a series of “spontaneous” blips ranging in amplitude from 3.8 ± 0.9 nA at the beginning of the recordings to 6.8 ± 1.7 nA after 15 min of exposure to 1 μM aggregate. These blips were similar in amplitude to those induced by the channel-forming antimicrobial agents amphotericin B (7.8 ± 1.2 nA) and gramicidin (6.3 ± 1.1 nA). The amyloid aggregate-induced currents were abolished when extracellular Ca2+ was removed from the bathing solution, suggesting a central role for this cation in generating the spontaneous electric activity. The amyloid aggregate also affected the Ca2+-dependent Cl− currents of oocytes, as shown by increased amplitude of the transient-outward chloride current (Tout) and the serum-activated, oscillatory Cl− currents. Electron microcopy revealed that amyloid aggregate induced the dissociation of the follicular cells that surround the oocyte, thus leading to a failure in the electro-chemical communication between these cells. This was also evidenced by the suppression of the oscillatory Ca2+-dependent ATP-currents, which require proper coupling between oocytes and the follicular cell layer. These observations, made using the X. laevis oocytes as a versatile experimental model, may help to understand the effects of amyloid aggregate on cellular communication. PMID:23104436

  5. A comparative study on carbon footprint of rice production between household and aggregated farms from Jiangxi, China.

    PubMed

    Yan, Ming; Luo, Ting; Bian, Rongjun; Cheng, Kun; Pan, Genxing; Rees, Robert

    2015-06-01

    Quantifying the carbon footprint (CF) for crop production can help identify key options to mitigate greenhouse gas (GHG) emissions in agriculture. In the present study, both household and aggregated farm scales were surveyed to obtain the data of rice production and farming management practices in a typical rice cultivation area of Northern Jiangxi, China. The CFs of the different rice systems including early rice, late rice, and single rice under household and aggregated farm scale were calculated. In general, early rice had the lower CF in terms of land use and grain production being 4.54 ± 0.44 t CO2-eq./ha and 0.62 ± 0.1 t CO2-eq./t grain than single rice (6.84 ± 0.79 t CO2-eq./ha and 0.80 ± 0.13 t CO2-eq./t grain) and late rice (8.72 ± 0.54 t CO2-eq./ha and 1.1 ± 0.17 t CO2-eq./t grain). The emissions from nitrogen fertilizer use accounted for 33 % of the total CF on average and the direct CH4 emissions for 57 %. The results indicated that the CF of double rice cropping under aggregated farm being 0.86 ± 0.11 t CO2-eq./t grain was lower by 25 % than that being 1.14 ± 0.25 t CO2-eq./t grain under household farm, mainly due to high nitrogen use efficiency and low methane emissions. Therefore, developing the aggregated farm scale with efficient use of agro-chemicals and farming operation for greater profitability could offer a strategy for reducing GHG emissions in China's agriculture.

  6. Uncertainty Product Scattering Function Estimation

    DTIC Science & Technology

    1994-01-01

    of the receiver may be written as I’(,,,•)1L- L//_+ " s(•S(-T, O4’),2-1 .(,, A4,) drd4 𔃻 (2.12) where •r =--r- ÷(2.13) and (2.14) In Equation (2.12...the ambiguity function is constant regardless of the normalized signal, i. e. I x (r,( ) 12 drd4 =I X(0 ,0 ) 12. (2.24) This property, which is known...functions where P,(÷L•) +J’C f+R0 .(r, 4)Tf,(L7T, AO) drd4 + [ L Lo 1?.(-, 4){,_x , A~,/4,)x.Z,(Ar,( )A(4( ) + + X,(AT•, A4’)x;,(AT, A4’) + Xgf(AT, A4’)X

  7. Effect of aggregate size in cell cultures of Saussurea medusa on cell growth and jaceosidin production.

    PubMed

    Zhao, D; Huang, Y; Jin, Z; Qu, W; Lu, D

    2003-07-01

    Cell suspension cultures of Saussurea medusa were grown in shake flasks and a 5-l stirred tank bioreactor. Biomass and jaceosidin distribution in cell aggregates of different sizes were investigated during the cultivation period. The results showed that on day 10, jaceosidin accumulation showed an increase with increasing size of the cell aggregate to 4 mm in diameter, with the highest jaceosidin accumulation being 12.2 mg/g. An inverse tendency was observed with cell aggregates larger than 4 mm in diameter, with the lowest accumulation being 3.1 mg/g. However, all of the cell aggregates, despite their size, synthesized almost the same amount of jaceosidin at day 12. Oxygen diffusion limitation and cell-cell contact may explain this behavior. In comparison with cells cultivated in shake flasks, decreased biomass and decreased jaceosidin concentration were observed when the cells were cultivated in a stirred tank bioreactor. The sublytic effects caused by the hydrodynamic stress in combination with insufficient nutrients in the bioreactor may cause cell damage.

  8. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1996-01-01

    Part of the Annual Commodities Review 1995. Production of construction aggregates such as crushed stone and construction sand and gravel showed a marginal increase in 1995. Most of the 1995 increases were due to funding for highway construction work. The major areas of concern to the industry included issues relating to wetlands classification and the classification of crystalline silica as a probable human carcinogen. Despite this, an increase in demand is anticipated for 1996.

  9. Measurement of platelet aggregation functions using whole blood migration ratio in a microfluidic chip.

    PubMed

    Seo, Hong Seog; Choi, Sung Hyuk; Han, Miran; Kim, Kyeong Ah; Cho, Chi Hyun; An, Seong Soo A; Lim, Chae Seung; Shin, Sehyun

    2016-01-01

    Platelets play a major role in maintaining endothelial integrity and hemostasis. Of the various soluble agonists, ADP is an important in vivo stimulus for inducing platelet aggregation. In this study, a simple, rapid, and affordable method was designed for testing bleeding time (BT) and platelet aggregation with a two-channel microfluidic chip. Whole blood migration ratio (MR) from a microchip system was evaluated in comparison to the closure time (CT) from PFA-100 assays (Siemens, Germany) and CD62P expression on platelets. To induce platelet aggregation, a combination of collagen (1.84 mg/ml) and ADP (37.5 mg/ml) were used as agonists. After adding the agonists to samples, whole blood MR from the microchip system was measured. The outcome of the assessment depended on reaction time and agonist concentration. MR of whole blood from the microchip system was significantly correlated with CT from PFA-100 (r = 0.61, p <  0.05, n = 60). In addition, MR was negatively correlated with CD62P expression (r =-0.95, p <  0.05, n = 60). These results suggest that the measurement of MR using agonists is an easy, simple and efficient method for monitoring platelet aggregation in normal and ADP-receptors defective samples, along with the BT test. Thus, usage of the current microfluidic method could expand to diverse applications, including efficacy assessments in platelet therapy.

  10. Challenges for simultaneous nitrification, denitrification, and phosphorus removal in microbial aggregates: mass transfer limitation and nitrous oxide production.

    PubMed

    Meyer, Rikke Louise; Zeng, Raymond Jianxiong; Giugliano, Valerio; Blackall, Linda Louise

    2005-05-01

    The microbial community composition and activity was investigated in aggregates from a lab-scale bioreactor, in which nitrification, denitrification and phosphorus removal occurred simultaneously. The biomass was highly enriched for polyphosphate accumulating organisms facilitating complete removal of phosphorus from the bulk liquid; however, some inorganic nitrogen still remained at the end of the reactor cycle. This was ascribed to incomplete coupling of nitrification and denitrification causing NO(3)(-) accumulation. After 2 h of aeration, denitrification was dependent on the activity of nitrifying bacteria facilitating the formation of anoxic zones in the aggregates; hence, denitrification could not occur without simultaneous nitrification towards the end of the reactor cycle. Nitrous oxide was identified as a product of denitrification, when based on stored PHA as carbon source. This observation is of critical importance to the outlook of applying PHA-driven denitrification in activated sludge processes.

  11. Nontronite Particle Aggregation Induced by Microbial Fe(III) Reduction and Exopolysaccharide Production

    DTIC Science & Technology

    2007-01-01

    R., Bressollier, P. and Urdaci, M.C. (2003) Isolation capsules of Shewanella spp. Applied and Environmental and characterization of two...clay-particle aggregation. Microbial Fe(l1I) reduction experiments were conducted with Shewanella putrefaciens CN32 in bicarbonate buffer with...reduction, and pure EPS isolated from CN32 cells was used to examine the effect of EPS. The data showed that both Fe(lII) reduction and EPS were

  12. Formation of nucleoplasmic protein aggregates impairs nuclear function in response to SiO{sub 2} nanoparticles

    SciTech Connect

    Chen Min; Mikecz, Anna von . E-mail: mikecz@uni-duesseldorf.de

    2005-04-15

    Despite of their exponentially growing use, little is known about cell biological effects of nanoparticles. Here, we report uptake of silica (SiO{sub 2}) nanoparticles to the cell nucleus where they induce aberrant clusters of topoisomerase I (topo I) in the nucleoplasm that additionally contain signature proteins of nuclear domains, and protein aggregation such as ubiquitin, proteasomes, cellular glutamine repeat (polyQ) proteins, and huntingtin. Formation of intranuclear protein aggregates (1) inhibits replication, transcription, and cell proliferation; (2) does not significantly alter proteasomal activity or cell viability; and (3) is reversible by Congo red and trehalose. Since SiO{sub 2} nanoparticles trigger a subnuclear pathology resembling the one occurring in expanded polyglutamine neurodegenerative disorders, we suggest that integrity of the functional architecture of the cell nucleus should be used as a read out for cytotoxicity and considered in the development of safe nanotechnology.

  13. Heat-shock protein dysregulation is associated with functional and pathological TDP-43 aggregation

    NASA Astrophysics Data System (ADS)

    Chang, Hsiang-Yu; Hou, Shin-Chen; Way, Tzong-Der; Wong, Chi-Huey; Wang, I.-Fan

    2013-11-01

    Conformational disorders are involved in various neurodegenerative diseases. Reactive oxygen species (ROS) are the major contributors to neurodegenerative disease; however, ROS that affect the structural changes in misfolded disease proteins have yet to be well characterized. Here we demonstrate that the intrinsic propensity of TDP-43 to aggregate drives the assembly of TDP-43-positive stress granules and soluble toxic TDP-43 oligomers in response to a ROS insult via a disulfide crosslinking-independent mechanism. Notably, ROS-induced TDP-43 protein assembly correlates with the dynamics of certain TDP-43-associated chaperones. The heat-shock protein (HSP)-90 inhibitor 17-AAG prevents ROS-induced TDP-43 aggregation, alters the type of TDP-43 multimers and reduces the severity of pathological TDP-43 inclusions. In summary, our study suggests that a common mechanism could be involved in the pathogenesis of conformational diseases that result from HSP dysregulation.

  14. Bletilla striata Micron Particles Function as a Hemostatic Agent by Promoting Rapid Blood Aggregation

    PubMed Central

    Zhang, Chen; Zeng, Rui; Liao, Zhencheng; Fu, Chaomei; Luo, Hui

    2017-01-01

    The human body cannot control blood loss without treatment. Available hemostatic agents are ineffective at treating cases of severe bleeding and are expensive or raise safety concerns. Bletilla striata serve as an inexpensive, natural, and promising alternative. However, no detailed studies on its hemostatic approach have been performed. The aim of this study was to examine the hemostatic effects of B. striata Micron Particles (BSMPs) and their hemostatic mechanisms. We prepared and characterized BSMPs of different size ranges and investigated their use as hemostatic agent. BSMPs of different size ranges were characterized by scanning electron microscope. In vitro coagulation studies revealed BSMP-blood aggregate formation via stereoscope and texture analyzers. In vivo studies based on rat injury model illustrated the BSMP capabilities under conditions of hemostasis. Compared to other BSMPs of different size ranges, BSMPs of 350–250 μm are most efficient in hemostasis. As powder sizes decrease, the degree of aggregation between particles and hemostatic BSMP effects declines. The BSMP in contact with a bleeding surface locally forms a visible particle/blood aggregate as a physical barrier that facilitates hemostasis. Considering the facile preparation, low cost, and long shelf life of B. striata, BSMPs offer great potential as mechanisms of trauma treatment. PMID:28386291

  15. Production efficiencies of U.S. electric generation plants: Effects of data aggregation and greenhouse gas and renewable energy policy

    NASA Astrophysics Data System (ADS)

    Lynes, Melissa Kate

    Over the last few decades there has been a shift in electricity production in the U.S. Renewable energy sources are becoming more widely used. In addition, electric generation plants that use coal inputs are more heavily regulated than a couple decades ago. This shift in electricity production was brought on by changes in federal policy -- a desire for electricity produced in the U.S. which led to policies being adopted that encourage the use of renewable energy. The change in production practices due to policies may have led to changes in the productivity of electric generation plants. Multiple studies have examined the most efficient electric generation plants using the data envelopment analysis (DEA) approach. This study builds on past research to answer three questions: 1) Does the level of aggregation of fuel input variables affect the plant efficiency scores and how does the efficiency of renewable energy input compare to nonrenewable energy inputs; 2) Are policies geared toward directly or indirectly reducing greenhouse gas emissions affecting the production efficiencies of greenhouse gas emitting electric generation plants; and 3) Do renewable energy policies and the use of intermittent energy sources (i.e. wind and solar) affect the productivity growth of electric generation plants. All three analysis, presented in three essays, use U.S. plant level data obtained from the Energy Information Administration to answer these questions. The first two essays use DEA to determine the pure technical, overall technical, and scale efficiencies of electric generation plants. The third essay uses DEA within the Malmquist index to assess the change in productivity over time. Results indicate that the level of aggregation does matter particularly for scale efficiency. This implies that valuable information is likely lost when fuel inputs are aggregated together. Policies directly focused on reducing greenhouse gas emissions may improve the production efficiencies of

  16. Functional chromatographic technique for natural product isolation†

    PubMed Central

    Lau, Eric C.; Mason, Damian J.; Eichhorst, Nicole; Engelder, Pearce; Mesa, Celestina; Kithsiri Wijeratne, E. M.; Gunaherath, G. M. Kamal B.; Leslie Gunatilaka, A. A.

    2015-01-01

    Natural product discovery arises through a unique interplay between chromatographic purification and biological assays. Currently, most techniques used for natural product purification deliver leads without a defined biological action. We now describe a technique, referred to herein as functional chromatography, that deploys biological affinity as the matrix for compound isolation. PMID:25588099

  17. Effect of Mineral Trioxide Aggregate, Calcium-Enriched Mixture Cement and Mineral Trioxide Aggregate with Disodium Hydrogen Phosphate on BMP-2 Production

    PubMed Central

    Ghasemi, Negin; Rahimi, Saeed; Lotfi, Mehrdad; Solaimanirad, Jafar; Shahi, Shahriar; Shafaie, Hajar; Salem Milani, Amin; Shakuie, Sahar; Zand, Vahid; Abdolrahimi, Majid

    2014-01-01

    Introduction: One of the hypotheses regarding the calcification induction by mineral trioxide aggregate (MTA) is the involvement of transforming growth factor-Beta (TGF-β) super family. Calcium-enriched mixture (CEM) cement is one of the endodontic biomaterials with clinical applications similar to MTA. The aim of the present in vitro study was to compare the induction of bone morphogenic protein-2 (BMP-2) by a combination of disodium hydrogen phosphate (DSHP) and tooth colored ProRoot MTA (WMTA), to that of CEM cement and WMTA. Methods and Materials: Human gingival fibroblasts (HGFs) were obtained from the attached gingiva of human premolars. HGFs were cultured in Dulbecco’s Modified Eagle’s medium, supplemented with 10% fetal calf serum, penicillin, and streptomycin. Cells in groups 1, 2 and 3 were exposed to WMTA, CEM and WMTA+DSHP discs, respectively. The fourth group served as the control. After 72 h of exposure, HGF viability was determined by Mosmann’s tetrazolium toxicity (MTT) assay. BMP-2 levels in cell-free culture media were determined by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using the one-way ANOVA, followed by the post hoc Games-Howell test for BMP-2 and post hoc Tukey’s test for the results of MTT assay. Results: Cellular viability was significantly higher in group 3 compared to the other groups (P<0.05); however, CEM and WMTA did not exhibit significant differences (P=0.08). The control group exhibited significantly higher cellular viability in comparison to the other groups of the study (P<0.05). The highest and lowest protein production rates were observed in the WMTA (3167±274.46 pg/mL) and WMTA+DSHP (1796±839.49 pg/mL) groups, respectively. There were no significant differences between the control, WMTA and CEM groups (P>0.05). Conclusion: WMTA and CEM did not exhibit any significant differences in terms of inducing BMP-2 production; however, incorporation of DSHP into WMTA resulted in a

  18. Development of Functional Nanomaterials with Aggregation-Induced Emission Characteristics and Exploration of Their Biological Applications

    NASA Astrophysics Data System (ADS)

    Hong, Yuning

    2011-12-01

    The development of fluorescent biosensors with high sensitivity, selectivity, and biocompatibility is of critical importance to bioscience and biotechnology because it offers a direct visualization tool for the detection of biological macromolecules and the monitoring of biological events under real and living conditions. Most of the conventional organic fluorophores exhibit remarkably bright emission in their dilute solutions but become weakly or even nonemissive when aggregated or in solid state, which has greatly limited the scope of their applications. An opposite phenomenon has recently been discovered: a group of nonluminescent molecules are induced to emit efficiently by aggregate formation. "Aggregation-induced emission" (AIE) is coined for this novel effect. Attracted by the intriguing phenomenon and its fascinating perspectives, we have launched a new program directed towards the development of new AIE materials and exploration of their biological applications. A new class of water-soluble AIE luminogens are designed and synthesized. Hydrophilic groups such as hydroxyl, sulfonate, and amino groups are introduced to make the AIE molecules readily soluble in water. Being practically non-emissive in water, these AIE dyes are lightened up when bound to biomacromolecules, such as proteins and DNA, thus enabling the quantitation and visualization of biomacromolecules in aqueous solutions and in electrophoretic gels. The AIE luminogens are sensitive to microenvironment inside the biomolecules and their fluorescent intensity can readily reflect the global stability of the biomolecules. In this work, we employ the AIE luminogens as fluorescent reporters for the monitoring of G-quadruplex DNA folding, protein unfolding by denaturant and protein misfolding into amyloid fibrils. Thanks to the AIE characteristics, the delicate information on the conformational transition of the biomolecules can be revealed. In addition, lipophilic AIE luminogens form highly emissive

  19. Supplemental Information: Phototransformation-Induced Aggregation of Functionalized Single-Walled Carbon Nanotubes: the Importance of Amorphous Carbon

    EPA Pesticide Factsheets

    Additional information about the carboxylated SWCNT calibration curve, AFM images, EDS results, solar simulator light and UVB lamp spectra, TEM image ofparent carboxylated SWCNTs, XPS spectra of the dark control P3 sample and the irradiated P3 sample, and a table summarizing the kinetic parameters (PDF)This dataset is associated with the following publication:Hou, W., C. He, Y. Wang, D. Wang, and R. Zepp. Phototransformation-Induced Aggregation of Functionalized Single-Walled Carbon Nanotubes: The Importance of Amorphous Carbon. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 50(7): 3494–3502, (2016).

  20. A motor neuron disease–associated mutation in p150Glued perturbs dynactin function and induces protein aggregation

    PubMed Central

    Levy, Jennifer R.; Sumner, Charlotte J.; Caviston, Juliane P.; Tokito, Mariko K.; Ranganathan, Srikanth; Ligon, Lee A.; Wallace, Karen E.; LaMonte, Bernadette H.; Harmison, George G.; Puls, Imke; Fischbeck, Kenneth H.; Holzbaur, Erika L.F.

    2006-01-01

    The microtubule motor cytoplasmic dynein and its activator dynactin drive vesicular transport and mitotic spindle organization. Dynactin is ubiquitously expressed in eukaryotes, but a G59S mutation in the p150Glued subunit of dynactin results in the specific degeneration of motor neurons. This mutation in the conserved cytoskeleton-associated protein, glycine-rich (CAP-Gly) domain lowers the affinity of p150Glued for microtubules and EB1. Cell lines from patients are morphologically normal but show delayed recovery after nocodazole treatment, consistent with a subtle disruption of dynein/dynactin function. The G59S mutation disrupts the folding of the CAP-Gly domain, resulting in aggregation of the p150Glued protein both in vitro and in vivo, which is accompanied by an increase in cell death in a motor neuron cell line. Overexpression of the chaperone Hsp70 inhibits aggregate formation and prevents cell death. These data support a model in which a point mutation in p150Glued causes both loss of dynein/dynactin function and gain of toxic function, which together lead to motor neuron cell death. PMID:16505168

  1. An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations.

    PubMed

    Hopkins, Zachary R; Blaney, Lee

    2016-01-01

    Over the past 3-4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th-75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species.

  2. Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths.

    PubMed

    Kunoh, Tatsuki; Nagaoka, Noriyuki; McFarlane, Ian R; Tamura, Katsunori; El-Naggar, Mohamed Y; Kunoh, Hitoshi; Takada, Jun

    2016-08-01

    Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales.

  3. Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths

    PubMed Central

    Kunoh, Tatsuki; Nagaoka, Noriyuki; McFarlane, Ian R.; Tamura, Katsunori; El-Naggar, Mohamed Y.; Kunoh, Hitoshi; Takada, Jun

    2016-01-01

    Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales. PMID:27490579

  4. Abiotic factors in colony formation: effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

    NASA Astrophysics Data System (ADS)

    Yang, Zhen; Kong, Fanxiang

    2013-07-01

    Colony morphology is important for Microcystis to sustain a competitive advantage in eutrophic lakes. The mechanism of colony formation in Microcystis is currently unclear. Extracellular polysaccharide (EPS) has been reported to play an important role in cell aggregate formation of some phytoplankton. Microcystis aeruginosa was cultivated under varied abiotic conditions, including different nutrient, light, and temperature conditions, to investigate their effects on EPS production and morphological change. The results show that nutrient concentration and light intensity have great effects on EPS productionin M. aeruginosa. There was a considerable increase in EPS production after M. aeruginosa was cultivated in adjusted culture conditions similar to those present in the field (28.9 mg C/L, 1.98 mg N/L, 0.65 mg P/L, light intensity: 100 μmol/(m2 · s)). These results indicate that abiotic factors might be one of the triggers for colony formation in Microcystis.

  5. Dispersion and Functionalization of Nanoparticles Synthesized by Gas Aggregation Source: Opening New Routes Toward the Fabrication of Nanoparticles for Biomedicine.

    PubMed

    Oprea, B; Martínez, L; Román, E; Vanea, E; Simon, S; Huttel, Y

    2015-12-29

    The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular, gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition, and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, which is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source using a Fe50B50 target and their further dispersion and functionalization with polyethyleneglycol (PEG). Characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles, creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivity measurements of these PEG-functionalized nanoparticles assessed their effectiveness as contrast agents for magnetic resonance imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine.

  6. Aggregate exposure approaches for parabens in personal care products: a case assessment for children between 0 and 3 years old.

    PubMed

    Gosens, Ilse; Delmaar, Christiaan J E; Ter Burg, Wouter; de Heer, Cees; Schuur, A Gerlienke

    2014-01-01

    In the risk assessment of chemical substances, aggregation of exposure to a substance from different sources via different pathways is not common practice. Focusing the exposure assessment on a substance from a single source can lead to a significant underestimation of the risk. To gain more insight on how to perform an aggregate exposure assessment, we applied a deterministic (tier 1) and a person-oriented probabilistic approach (tier 2) for exposure to the four most common parabens through personal care products in children between 0 and 3 years old. Following a deterministic approach, a worst-case exposure estimate is calculated for methyl-, ethyl-, propyl- and butylparaben. As an illustration for risk assessment, Margins of Exposure (MoE) are calculated. These are 991 and 4966 for methyl- and ethylparaben, and 8 and 10 for propyl- and butylparaben, respectively. In tier 2, more detailed information on product use has been obtained from a small survey on product use of consumers. A probabilistic exposure assessment is performed to estimate the variability and uncertainty of exposure in a population. Results show that the internal exposure for each paraben is below the level determined in tier 1. However, for propyl- and butylparaben, the percentile of the population with an exposure probability above the assumed "safe" MoE of 100, is 13% and 7%, respectively. In conclusion, a tier 1 approach can be performed using simple equations and default point estimates, and serves as a starting point for exposure and risk assessment. If refinement is warranted, the more data demanding person-oriented probabilistic approach should be used. This probabilistic approach results in a more realistic exposure estimate, including the uncertainty, and allows determining the main drivers of exposure. Furthermore, it allows to estimate the percentage of the population for which the exposure is likely to be above a specific value.

  7. Phototransformation-Induced Aggregation of Functionalized Single-Walled Carbon Nanotubes: The Importance of Amorphous Carbon

    EPA Science Inventory

    Single-walled carbon nanotubes (SWCNTs) with proper functionalization are desirable for applications that require dispersion in aqueous and biological environments, and functionalized SWCNTs also serve as building blocks for conjugation with specific molecules in these applicatio...

  8. Water Production Functions for High Plains Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water Production Functions for High Plains Crops Water consumptive use by a crop can be reduced through limited (deficit) irrigation. If the reduced consumptive use (CU) can be quantified, the saved water can be transferred to other users. If the value of the transferred water is greater than the fa...

  9. Amyloid-beta aggregation: selective inhibition of aggregation in mixtures of amyloid with different chain lengths.

    PubMed Central

    Snyder, S W; Ladror, U S; Wade, W S; Wang, G T; Barrett, L W; Matayoshi, E D; Huffaker, H J; Krafft, G A; Holzman, T F

    1994-01-01

    One of the clinical manifestations of Alzheimer's disease is the deposition of the 39-43 residue amyloid-beta (A beta) peptide in aggregated fibrils in senile plaques. Characterization of the aggregation behavior of A beta is one of the critical issues in understanding the role of A beta in the disease process. Using solution hydrodynamics, A beta was observed to form three types of species in phosphate-buffered saline: insoluble aggregates with sedimentation coefficients of approximately 50,000 S and molecular masses of approximately 10(9) Da, "soluble aggregates" with sedimentation coefficients of approximately 30 S and masses of approximately 10(6) Da, and monomer. When starting from monomer, the aggregation kinetics of A beta 1-40 (A beta 40) and A beta 1-42 (A beta 42), alone and in combination, reveal large differences in the tendency of these peptides to aggregate as a function of pH and other solution conditions. At pH 4.1 and 7.0-7.4, aggregation is significantly slower than at pH 5 and 6. Under all conditions, aggregation of the longer A beta 42 was more rapid than A beta 40. Oxidation of Met-35 to the sulfoxide in A beta 40 enhances the aggregation rate over that of the nonoxidized peptide. Aggregation was found to be dependent upon temperature and to be strongly dependent on peptide concentration and ionic strength, indicating that aggregation is driven by a hydrophobic effect. When A beta 40 and A beta 42 are mixed together, A beta 40 retards the aggregation of A beta 42 in a concentration-dependent manner. Shorter fragments have a decreasing ability to interfere with A beta 42 aggregation. Conversely, the rate of aggregation of A beta 40 can be significantly enhanced by seeding slow aggregating solutions with preformed aggregates of A beta 42. Taken together, the inhibition of A beta 42 aggregation by A beta 40, the seeding of A beta 40 aggregation by A beta 42 aggregates, and the chemical oxidation of A beta 40 suggest that the relative abundance and

  10. Proteins that accumulate with age in human skeletal-muscle aggregates contribute to declines in muscle mass and function in Caenorhabditis elegans

    PubMed Central

    Ayyadevara, Srinivas; Balasubramaniam, Meenakshisundaram; Suri, Pooja; Mackintosh, Samuel G.; Tackett, Alan J.; Sullivan, Dennis H.; Shmookler Reis, Robert J.; Dennis, Richard A.

    2016-01-01

    Protein aggregation increases with age in normal tissues, and with pathology and age in Alzheimer's hippocampus and mouse cardiac muscle. We now ask whether human skeletal muscle accumulates aggregates with age. Detergent-insoluble protein aggregates were isolated from vastus lateralis biopsies from 5 young (23–27 years of age) and 5 older (64–80 years) adults. Aggregates, quantified after gel electrophoresis, contain 2.1-fold more protein (P<0.0001) when isolated from older subjects relative to young. Of 515 proteins identified by liquid chromatography coupled to tandem mass spectrometry, 56 (11%) were significantly more abundant in older muscle, while 21 (4%) were depleted with age (each P<0.05). Orthologs to seven of these proteins were then targeted in C. elegans by RNA interference. Six of the seven knockdown treatments decreased protein aggregation (range 6–45%, P<0.01 to <0.0001) and increased muscle mass (range 1.5- to 1.85-fold, P<0.01 to <0.0001) in aged nematodes, and rescued mobility (range 1.4 to 1.65-fold, P≤0.0005 each) in a nematode amyloidopathy model. We conclude that specific aggregate proteins, discovered as differentially abundant in aging human muscle, have orthologs that contribute functionally to aggregation and age-associated muscle loss in nematodes, and thus can be considered potential drug targets for sarcopenia in humans. PMID:27992858

  11. Blood–brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate

    PubMed Central

    Shityakov, Sergey; Salvador, Ellaine; Pastorin, Giorgia; Förster, Carola

    2015-01-01

    In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT–FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood–brain barrier. The results indicated that the MWCNT–FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell® system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT–FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT–FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCNT–FITC rapid dissociation as an intermediate phase. PMID:25784800

  12. Blood-brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate.

    PubMed

    Shityakov, Sergey; Salvador, Ellaine; Pastorin, Giorgia; Förster, Carola

    2015-01-01

    In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell(®) system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCNT-FITC rapid dissociation as an intermediate phase.

  13. Clustered functional MRI of overt speech production.

    PubMed

    Sörös, Peter; Sokoloff, Lisa Guttman; Bose, Arpita; McIntosh, Anthony R; Graham, Simon J; Stuss, Donald T

    2006-08-01

    To investigate the neural network of overt speech production, event-related fMRI was performed in 9 young healthy adult volunteers. A clustered image acquisition technique was chosen to minimize speech-related movement artifacts. Functional images were acquired during the production of oral movements and of speech of increasing complexity (isolated vowel as well as monosyllabic and trisyllabic utterances). This imaging technique and behavioral task enabled depiction of the articulo-phonologic network of speech production from the supplementary motor area at the cranial end to the red nucleus at the caudal end. Speaking a single vowel and performing simple oral movements involved very similar activation of the cortical and subcortical motor systems. More complex, polysyllabic utterances were associated with additional activation in the bilateral cerebellum, reflecting increased demand on speech motor control, and additional activation in the bilateral temporal cortex, reflecting the stronger involvement of phonologic processing.

  14. Grid Integration of Aggregated Demand Response, Part 2: Modeling Demand Response in a Production Cost Model

    SciTech Connect

    Hummon, Marissa; Palchak, David; Denholm, Paul; Jorgenson, Jennie; Olsen, Daniel J.; Kiliccote, Sila; Matson, Nance; Sohn, Michael; Rose, Cody; Dudley, Junqiao; Goli, Sasank; Ma, Ookie

    2013-12-01

    This report is one of a series stemming from the U.S. Department of Energy (DOE) Demand Response and Energy Storage Integration Study. This study is a multi-national-laboratory effort to assess the potential value of demand response (DR) and energy storage to electricity systems with different penetration levels of variable renewable resources and to improve our understanding of associatedmarkets and institutions. This report implements DR resources in the commercial production cost model PLEXOS.

  15. Black tattoo inks induce reactive oxygen species production correlating with aggregation of pigment nanoparticles and product brand but not with the polycyclic aromatic hydrocarbon content.

    PubMed

    Høgsberg, Trine; Jacobsen, Nicklas Raun; Clausen, Per Axel; Serup, Jørgen

    2013-07-01

    Black tattoo inks are composed of carbon nanoparticles, additives and water and may contain polycyclic aromatic hydrocarbons (PAHs). We aimed to clarify whether reactive oxygen species (ROS) induced by black inks in vitro is related to pigment chemistry, physico-chemical properties of the ink particles and the content of chemical additives and contaminants including PAHs. The study included nine brands of tattoo inks of six colours each (black, red, yellow, blue, green and white) and two additional black inks of different brands (n = 56). The ROS formation potential was determined by the dichlorofluorescein (DCFH) assay. A semiquantitative method was developed for screening extractable organic compounds in tattoo ink based on gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Two black inks produced high amounts of ROS. Peroxyl radicals accounted for up to 72% of the free radicals generated, whereas hydroxyl radicals and H₂O₂ accounted for <14% and 16%, respectively. The same two inks aggregated strongly in water in contrast to the other black inks. They did not exhibit any shared pattern in PAHs and other organic substances. Aggregation was exclusively shared by all ink colours belonging to the same two brands. Ten of 11 black inks had PAH concentrations exceeding the European Council's recommended level, and all 11 exceeded the recommended level for benzo(a)pyrene. It is a new finding that aggregation of tattoo pigment particles correlates with ROS production and brand, independently of chemical composition including PAHs. ROS is hypothesized to be implicated in minor clinical symptoms.

  16. Thermal and Hydrodynamic Environments Mediate Individual and Aggregative Feeding of a Functionally Important Omnivore in Reef Communities

    PubMed Central

    Frey, Desta L.; Gagnon, Patrick

    2015-01-01

    In eastern Canada, the destruction of kelp beds by dense aggregations (fronts) of the omnivorous green sea urchin, Strongylocentrotus droebachiensis, is a key determinant of the structure and dynamics of shallow reef communities. Recent studies suggest that hydrodynamic forces, but not sea temperature, determine the strength of urchin-kelp interactions, which deviates from the tenets of the metabolic theory of ecology (MTE). We tested the hypothesis that water temperature can predict short-term kelp bed destruction by S. droebachiensis in calm hydrodynamic environments. Specifically, we experimentally determined relationships among water temperature, body size, and individual feeding in the absence of waves, as well as among wave velocity, season, and aggregative feeding. We quantified variation in kelp-bed boundary dynamics, sea temperature, and wave height over three months at one subtidal site in Newfoundland to test the validity of thermal tipping ranges and regression equations derived from laboratory results. Consistent with the MTE, individual feeding during early summer (June-July) obeyed a non-linear, size- and temperature-dependent relationship: feeding in large urchins was consistently highest and positively correlated with temperature <12°C and dropped within and above the 12–15°C tipping range. This relationship was more apparent in large than small urchins. Observed and expected rates of kelp loss based on sea temperature and urchin density and size structure at the front were highly correlated and differed by one order of magnitude. The present study speaks to the importance of considering body size and natural variation in sea temperature in studies of urchin-kelp interactions. It provides the first compelling evidence that sea temperature, and not only hydrodynamic forces, can predict kelp bed destruction by urchin fronts in shallow reef communities. Studying urchin-seaweed-predator interactions within the conceptual foundations of the MTE

  17. TMEM175 deficiency impairs lysosomal and mitochondrial function and increases α-synuclein aggregation

    PubMed Central

    Jinn, Sarah; Drolet, Robert E.; Cramer, Paige E.; Wong, Andus Hon-Kit; Toolan, Dawn M.; Gretzula, Cheryl A.; Voleti, Bhavya; Vassileva, Galya; Disa, Jyoti; Tadin-Strapps, Marija; Stone, David J.

    2017-01-01

    Parkinson disease (PD) is a neurodegenerative disorder pathologically characterized by nigrostriatal dopamine neuron loss and the postmortem presence of Lewy bodies, depositions of insoluble α-synuclein, and other proteins that likely contribute to cellular toxicity and death during the disease. Genetic and biochemical studies have implicated impaired lysosomal and mitochondrial function in the pathogenesis of PD. Transmembrane protein 175 (TMEM175), the lysosomal K+ channel, is centered under a major genome-wide association studies peak for PD, making it a potential candidate risk factor for the disease. To address the possibility that variation in TMEM175 could play a role in PD pathogenesis, TMEM175 function was investigated in a neuronal model system. Studies confirmed that TMEM175 deficiency results in unstable lysosomal pH, which led to decreased lysosomal catalytic activity, decreased glucocerebrosidase activity, impaired autophagosome clearance by the lysosome, and decreased mitochondrial respiration. Moreover, TMEM175 deficiency in rat primary neurons resulted in increased susceptibility to exogenous α-synuclein fibrils. Following α-synuclein fibril treatment, neurons deficient in TMEM175 were found to have increased phosphorylated and detergent-insoluble α-synuclein deposits. Taken together, data from these studies suggest that TMEM175 plays a direct and critical role in lysosomal and mitochondrial function and PD pathogenesis and highlight this ion channel as a potential therapeutic target for treating PD. PMID:28193887

  18. Using ecological production functions to link ecological ...

    EPA Pesticide Factsheets

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively little attention. Ecological production functions may be defined as usable expressions (i.e., models) of the processes by which ecosystems produce ES, often including external influences on those processes. We identify key attributes of EPFs and discuss both actual and idealized examples of their use to inform decision making. Whenever possible, EPFs should estimate final, rather than intermediate, ES. Although various types of EPFs have been developed, we suggest that EPFs are more useful for decision making if they quantify ES outcomes, respond to ecosystem condition, respond to stressor levels or management scenarios, reflect ecological complexity, rely on data with broad coverage, have performed well previously, are practical to use, and are open and transparent. In an example using pesticides, we illustrate how EPFs with these attributes could enable the inclusion of ES in ecological risk assessment. The biggest challenges to ES inclusion are limited data sets that are easily adapted for use in modeling EPFs and generally poor understanding of linkages among ecological components and the processes that ultimately deliver the ES. We conclude by advocating for the incorporation into E

  19. AggLb Is the Largest Cell-Aggregation Factor from Lactobacillus paracasei Subsp. paracasei BGNJ1-64, Functions in Collagen Adhesion, and Pathogen Exclusion In Vitro

    PubMed Central

    Miljkovic, Marija; Strahinic, Ivana; Tolinacki, Maja; Zivkovic, Milica; Kojic, Snezana; Golic, Natasa; Kojic, Milan

    2015-01-01

    Eleven Lactobacillus strains with strong aggregation abilities were selected from a laboratory collection. In two of the strains, genes associated with aggregation capability were plasmid located and found to strongly correlate with collagen binding. The gene encoding the auto-aggregation-promoting protein (AggLb) of Lactobacillus paracasei subsp. paracasei BGNJ1-64 was cloned using a novel, wide-range-host shuttle cloning vector, pAZILSJ. The clone pALb35, containing a 11377-bp DNA fragment, was selected from the SacI plasmid library for its ability to provide carriers with the aggregation phenotype. The complete fragment was sequenced and four potential ORFs were detected, including the aggLb gene and three surrounding transposase genes. AggLb is the largest known cell-surface protein in lactobacilli, consisting of 2998 aa (318,611 Da). AggLb belongs to the collagen-binding superfamily and its C-terminal region contains 20 successive repeats that are identical even at the nucleotide level. Deletion of aggLb causes a loss of the capacity to form cell aggregates, whereas overexpression increases cellular aggregation, hydrophobicity and collagen-binding potential. PCR screening performed with three sets of primers based on the aggLb gene of BGNJ1-64 enabled detection of the same type of aggLb gene in five of eleven selected aggregation-positive Lactobacillus strains. Heterologous expression of aggLb confirmed the crucial role of the AggLb protein in cell aggregation and specific collagen binding, indicating that AggLb has a useful probiotic function in effective colonization of host tissue and prevention of pathogen colonization. PMID:25955159

  20. Injury Profile SIMulator, a Qualitative Aggregative Modelling Framework to Predict Crop Injury Profile as a Function of Cropping Practices, and the Abiotic and Biotic Environment. I. Conceptual Bases

    PubMed Central

    Aubertot, Jean-Noël; Robin, Marie-Hélène

    2013-01-01

    The limitation of damage caused by pests (plant pathogens, weeds, and animal pests) in any agricultural crop requires integrated management strategies. Although significant efforts have been made to i) develop, and to a lesser extent ii) combine genetic, biological, cultural, physical and chemical control methods in Integrated Pest Management (IPM) strategies (vertical integration), there is a need for tools to help manage Injury Profiles (horizontal integration). Farmers design cropping systems according to their goals, knowledge, cognition and perception of socio-economic and technological drivers as well as their physical, biological, and chemical environment. In return, a given cropping system, in a given production situation will exhibit a unique injury profile, defined as a dynamic vector of the main injuries affecting the crop. This simple description of agroecosystems has been used to develop IPSIM (Injury Profile SIMulator), a modelling framework to predict injury profiles as a function of cropping practices, abiotic and biotic environment. Due to the tremendous complexity of agroecosystems, a simple holistic aggregative approach was chosen instead of attempting to couple detailed models. This paper describes the conceptual bases of IPSIM, an aggregative hierarchical framework and a method to help specify IPSIM for a given crop. A companion paper presents a proof of concept of the proposed approach for a single disease of a major crop (eyespot on wheat). In the future, IPSIM could be used as a tool to help design ex-ante IPM strategies at the field scale if coupled with a damage sub-model, and a multicriteria sub-model that assesses the social, environmental, and economic performances of simulated agroecosystems. In addition, IPSIM could also be used to help make diagnoses on commercial fields. It is important to point out that the presented concepts are not crop- or pest-specific and that IPSIM can be used on any crop. PMID:24019908

  1. Small angle x-ray scattering: Instrument development and studies of protein aggregation, cellulose hydrolysis, and the production of nanoporous metals using surfactact templates

    NASA Astrophysics Data System (ADS)

    Banuelos, Jose Leobardo

    Small angle x-ray scattering (SAXS) was used to obtain structural insights into protein aggregation, the enzymatic hydrolysis of cellulose, and the structural evolution of surfactant-templated nanoporous palladium and platinum systems during their synthesis. SAXS is bulk technique that allows probing the nanometer-scale morphology, interactions, density, and distribution of a variety of nonperiodic systems in the solid, liquid, or gaseous state. A 10-meter Small Angle Scattering camera, originally at ORNL, was assembled. During its re-commissioning, several upgrades were made including new data acquisition software built using National Instrument's Labview development environment, as well as portability to use analysis tools in wide use in scattering community. The Multiple Energy Diffractometer Using Small, medium and wide Angles (MEDUSA) was designed and built, its development will be discussed. The ability of proteins to change their conformation in response to changes in pressure, temperature, the presence of other molecular species, and ionic concentration in the solvents they are found, is a remarkable phenomenon that allows living cells to function properly. When proteins irreversibly unfold or mis-fold and aggregate this gives rise to severely debilitating diseases such as Alzheimer's and prion diseases. Protein aggregation was measured using SAXS on aqueous solutions of bovine serum albumin, myoglobin, and cellulase enzymes. Understanding how cellulose can be broken down into fermentable sugars is an important step in the development of strategies for producing alternative energy from biomass. The enzymatic hydrolysis of cellulose was studied using both small angle neutron scattering and SAXS. One result from these investigations was finding supporting evidence that nanopores within the cellulose fibril matrix allow biologically active enzymes access to digest parts of the fibers. The production of mesoporous materials for hydrogen storage applications was

  2. Functional characterization of toposomes from sea urchin blastula embryos by a morphogenetic cell aggregation assay.

    PubMed Central

    Matranga, V; Kuwasaki, B; Noll, H

    1986-01-01

    This paper documents the evidence that the large oligomeric glycoprotein complexes of unknown function first isolated as 22S particles from sea urchin embryos are the sole agents responsible for the adhesive integrity of sea urchin blastula embryos. The conclusion rests on the demonstration that polyclonal IgG (as serum or monovalent Fab) against whole membranes or butanol-solubilized components of membranes, as well as against the purified particle itself, completely blocks reaggregation of dissociated blastula cells and that this inhibition is reversed by neutralization of the inhibitory antibodies with purified 22S antigen. An essential aspect of the evidence is the combination of quantitative endpoint titrations in microtiter wells with the qualitative parameters of morphogenesis. The new data complement previous evidence that morphogenesis is mediated by a general class of particles, toposomes, responsible for mechanical linkage between cells and their positional guidance in embryogenesis. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:3816756

  3. The radio luminosity function of spiral galaxies - Correlations with aggregation and Hubble type

    NASA Astrophysics Data System (ADS)

    Gavazzi, G.; Trinchieri, G.

    1981-04-01

    The Radio Luminosity Function of spiral galaxies is derived from the Arecibo observations of UGC galaxies at 2380 MHz. It is found that the average radio power and the optical luminosity are linearly correlated (αL1) and that, at any given radio power, the probability for a spiral galaxy to become a radio source scales with the optical luminosity as L1.3. Both results confirm the analysis of Hummel (1980, b) who studied with the Westerbork radio telescope (WSRT) the 1415 MHz continuum emission from nearby spiral galaxies. It is also attempted to correlate the radio emission from spiral galaxies with their detailed Hubble type and cluster membership. A weak evidence is found that early type galaxies and cluster members are slightly deficient in radio emission with respect to late type or isolated galaxies, particularly among the optically brightest objects.

  4. Aggregating the benefits of environmental improvements: distance-decay functions for use and non-use values.

    PubMed

    Hanley, Nick; Schläpfer, Felix; Spurgeon, James

    2003-07-01

    One of the main problems in using environmental cost-benefit analysis is deciding on the relevant population: whose benefits should we count? This is important since aggregate benefits depend on both per-person benefit and the number of beneficiaries. Yet this latter term is often hard to evaluate. Distance-decay functions are one way of addressing this problem. In this paper, we present estimates of distance-decay functions for a particular environmental improvement, namely a reduction in low flow problems on the River Mimram in Southern England. We do this both for users and non-users, in the context of a contingent valuation study of the benefits of improving low flow conditions. We test whether distance-decay effects for mean Willingness to Pay are stronger for a single environmental good (the River Mimram, in this case) than for a more inclusive set (here, all rivers in Thames region which suffer from low flow problems). Finally, we explore the impact on part-whole bias, in terms of the relationship between WTP for an individual site and WTP for a more inclusive group of sites, of allowing for distance-decay effects.

  5. A nanoscale bio-inspired light-harvesting system developed from self-assembled alkyl-functionalized metallochlorin nano-aggregates.

    PubMed

    Ocakoglu, Kasim; Joya, Khurram S; Harputlu, Ersan; Tarnowska, Anna; Gryko, Daniel T

    2014-08-21

    Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The transparent Zn-chlorin nano-aggregates inside the alkyl-TiO2 modified AAO nano-channels have a diameter of ∼120 nm in a 60 μm length channel. UV-Vis studies and fluorescence emission spectra further confirm the formation of the supramolecular ZnChl aggregates from monomer molecules inside the alkyl-functionalized nano-channels. Our results prove that the novel and unique method can be used to produce efficient and stable light-harvesting assemblies for effective solar energy capture through transparent and stable nano-channel ceramic materials modified with bio-mimetic molecular self-assembled nano-aggregates.

  6. Assessing the recovery of functional diversity after sustained sediment screening at an aggregate dredging site in the North Sea

    NASA Astrophysics Data System (ADS)

    Barrio Froján, Christopher R. S.; Cooper, Keith M.; Bremner, Julie; Defew, Emma C.; Wan Hussin, Wan M. R.; Paterson, David M.

    2011-05-01

    The effects of dredging the seabed for aggregate on benthic functional diversity were assessed using a suite of suitable indices on a recovering macrofaunal assemblage. Recovery was assessed as the return of a dredged assemblage to a state found in neighbouring undisturbed (reference) sites. In situ sediment screening was permitted during dredging operations; a difference in the sedimentary profile of the seabed between dredged and undisturbed reference sites was also observed. At sites of relatively high and low dredging intensity the sediment appeared more homogenous than reference sites after the selective removal of the coarser component. Initial assessment of the macrofaunal assemblage using univariate analytical techniques suggested a recovery of functional diversity at the low dredging intensity site after two years (according to the Infaunal Trophic Index, Taxonomic Distinctness index and Rao's Quadratic Entropy coefficient). However, multivariate analyses of the same data and of all indices except Taxonomic Distinctness indicated that assemblages at both high and low dredging intensity sites remained statistically indistinguishable from each other yet markedly different to the assemblage present in the reference area during the four-year study. The study concluded that recovery of functional diversity to a level found in a neighbouring undredged habitat had not occurred at either dredged site five years after the cessation of dredging. It is thought that the damage by dredging to functional diversity and to the capacity of the macrofaunal assemblage to recover is immediate and not so dependent on dredging intensity. The cumulative and wider ranging effects of sediment screening cannot be ignored or dismissed as a contributing factor to the similarities observed. The wider significance of these findings on the regulation of dredging activities is discussed.

  7. Modeled diversity effects on microbial ecosystem functions of primary production, nutrient uptake, and remineralization.

    PubMed

    Goebel, Nicole L; Edwards, Christopher A; Follows, Michael J; Zehr, Jonathan P

    2014-01-01

    Ecosystem-wide primary productivity generally increases with primary producer diversity, emphasizing the importance of diversity for ecosystem function. However, most studies that demonstrate this positive relationship have focused on terrestrial and aquatic benthic systems, with little attention to the diverse marine pelagic primary producers that play an important role in regulating global climate. Here we show how phytoplankton biodiversity enhances overall marine ecosystem primary productivity and other ecosystem functions using a self-organizing ecosystem model. Diversity manipulation numerical experiments reveal positive, asymptotically saturating relationships between ecosystem-wide phytoplankton diversity and functions of productivity, nutrient uptake, remineralization, and diversity metrics used to identify mechanisms shaping these relationships. Increase in productivity with increasing diversity improves modeled ecosystem stability and model robustness and leads to productivity rates that exceed expected yields primarily through niche complementarity and facilitative interactions between coexisting phytoplankton types; the composition of traits in assemblages determines the magnitude of complementarity and selection effects. While findings based on these aggregate measures of diversity effects parallel those from the majority of experimental outcomes of terrestrial and benthic biodiversity-ecosystem function studies, we combine analyses of community diversity effects and investigations of the underlying interactions among phytoplankton types to demonstrate how an increase in recycled production of non-diatoms through an increase in new production of diatoms drives this diversity-cosystem function response. We demonstrate the important role that facilitation plays in the modeled marine plankton and how this facilitative interaction could amplify future climate-driven changes in ocean ecosystem productivity.

  8. Method for Producing Non-Neoplastic, Three Dimensional, Mammalian Tissue and Cell Aggregates Under Microgravity Culture Conditions and the Products Produced Therefrom

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas J. (Inventor); Wolf, David A. (Inventor); Spaulding, Glenn F. (Inventor); Prewett, Tracey L. (Inventor)

    1996-01-01

    Normal mammalian tissue and the culturing process has been developed for the three groups of organ, structural, and blood tissue. The cells are grown in vitro under microgravity culture conditions and form three dimensional cells aggregates with normal cell function. The microgravity culture conditions may be microgravity or simulated microgravity created in a horizontal rotating wall culture vessel.

  9. Sewage sludge sugarcane trash based compost and synthetic aggregates as peat substitutes in containerized media for crop production.

    PubMed

    Jayasinghe, G Y; Tokashiki, Yoshihiro; Arachchi, I D Liyana; Arakaki, Mika

    2010-02-15

    Effect of partial substitution of peat in growth media by sewage sludge sugarcane trash based compost (SSC) and synthetic aggregates (SA) on the physical and chemical characteristics of the growth media and on the growth and nutrition of lettuce (Lactuca sativa L.) grown in the substituted media was investigated under this study. SSC was produced from sugarcane trash and sewage sludge. Unconventional SA were produced by low productive acidic red soil with paper waste and starch waste. The treatments assayed were: SSC (40%)+Peat (60%), SA (40%)+Peat (60%), SSC (60%)+SA (40%), SSC (40%)+SA (20%)+Peat (40%) and SSC (40%)+SA (40%)+Peat (20%). Peat only was used as the control. The physical and chemical properties of all growing media were analyzed. SSC-SA based substrates showed adequate physical and chemical properties compared to peat for their use as growing media in horticulture. In relation to the plant growth in peat control, plants grown in the SSC-SA based substrates reached better growth and nutrition. The concentration of trace elements in plant tissues was far lower than the ranges considered phytotoxic for plants. Utilization of SSC and SA can be considered as an alternative media component to substitute the widely using expensive peat in horticulture.

  10. Quantitative risk assessment of the aggregate dermal exposure to the sensitizing fragrance geraniol in personal care products and household cleaning agents.

    PubMed

    Nijkamp, M M; Bokkers, B G H; Bakker, M I; Ezendam, J; Delmaar, J E

    2015-10-01

    A quantitative risk assessment was performed to establish if consumers are at risk for being dermally sensitized by the fragrance geraniol. Aggregate dermal exposure to geraniol was estimated using the Probabilistic Aggregate Consumer Exposure Model, containing data on the use of personal care products and household cleaning agents. Consumer exposure to geraniol via personal care products appeared to be higher than via household cleaning agents. The hands were the body parts receiving the highest exposure to geraniol. Dermal sensitization studies were assessed to derive the point of departure needed for the estimation of the Acceptable Exposure Level (AEL). Two concentrations were derived, one based on human studies and the other from dose-response analysis of the available murine local lymph node assay data. The aggregate dermal exposure assessment resulted in body part specific median exposures up to 0.041 μg/cm(2) (highest exposure 102 μg/cm(2)) for hands. Comparing the exposure to the lowest AEL (55 μg/cm(2)), shows that a range of 0.02-0.86% of the population may have an aggregated exposure which exceeds the AEL. Furthermore, it is demonstrated that personal care products contribute more to the consumer's geraniol exposure compared to household cleaning agents.

  11. Scalable Production of a Multifunctional Protein (TSG-6) That Aggregates with Itself and the CHO Cells That Synthesize It

    PubMed Central

    Kim, Dong-Ki; Choi, Hosoon; Nishida, Hidetaka; Oh, Joo Youn; Gregory, Carl; Lee, Ryang Hwa; Yu, Ji Min; Watanabe, Jun; An, Su Yeon; Bartosh, Thomas J.; Prockop, Darwin J.

    2016-01-01

    TNF-α stimulated gene/protein 6 (TNFAIP6/TSG-6) is a multifunctional protein that has a number of potential therapeutic applications. Experiments and clinical trials with TSG-6, however, have been limited by the technical difficulties of producing the recombinant protein. We prepared stable clones of CHO cells that expressed recombinant human TSG-6 (rhTSG-6) as a secreted glycoprotein. Paradoxically, both cell number and protein production decreased dramatically when the clones were expanded. The decreases occurred because the protein aggregated the synthesizing CHO cells by binding to the brush border of hyaluronan that is found around many cultured cells. In addition, the rhTSG-6 readily self-aggregated. To address these problems, we added to the medium an inhibitor of hyaluronan synthesis and heparin to compete with the binding of TSG-6 to hyaluronan. Also, we optimized the composition of the culture medium, and transferred the CHO cells from a spinner culture system to a bioreactor that controlled pH and thereby decreased pH-dependent binding properties of the protein. With these and other improvements in the culture conditions, we obtained 57.0 mg ± 9.16 S.D. of rhTSG-6 in 5 or 6 liter of medium. The rhTSG-6 accounted for 18.0% ± 3.76 S.D. of the total protein in the medium. We then purified the protein with a Ni-chelate column that bound the His tag engineered into the C-terminus of the protein followed by an anion exchange column. The yield of the purified monomeric rhTSG-6 was 4.1 mg to 5.6 mg per liter of culture medium. After intravenous injection into mice, the protein had a longer plasma half-life than commercially available rhTSG-6 isolated from a mammalian cell lysate, apparently because it was recovered as a secreted glycoprotein. The bioactivity of the rhTSG-6 in suppressing inflammation was demonstrated in a murine model. PMID:26793973

  12. Life's Impact on the Soil Production Function

    NASA Astrophysics Data System (ADS)

    Harrison, Emma; Willenbring, Jane; Brocard, Gilles

    2016-04-01

    Soil melds life and lithology, but the top-down production of soil by the incorporation of organic matter has typically been viewed through a lens of soil biogeochemistry and the bottom-up weathering of bedrock viewed from a geomorphologic perspective. We merge these perspectives by developing a variation on the classic geomorphological soil production function [1] that accounts for the influence of top-down soil production by additions of organic material. In the classic view [1], production rate of soil from bedrock weathering is a function of the thickness of the soil horizon. Under steady state conditions, this thickness is controlled by a constant coefficient of diffusion and by the hillslope curvature. Across the globe, equilibrium landscapes can be hard to find. We explore the many ways that biota influence the upper soil horizons and move the soil-hillslope system out of steady state using measurements of in situ 10Be at depth in soil profiles. Our empirical case study is in the Luquillo Critical Zone Observatory of northeastern Puerto Rico, where long term ecological monitoring suggests an average of 375 m My-1 of litter fall [2] and as much as 17.5 m My-1 of dust [3] is contributed to the forest floor. This substantial volume of material forms an active surficial layer, functionally increasing the residence time of grains deeper in the soil profile. Litter recycling influences the cosmogenic dose rate to be higher by increasing the residence time of grains and to be lower by increasing environmental shielding. In unconstrained systems, probabilistic modeling can determine a range of solutions for the ages of grains determined with 10Be depth profiles[4]. We compare the probabilistic outcomes to actual measurements of the in situ 10Be at depth in soil profiles from the Luquillo Mountains. Life living in the soil, rather than on it, is of equal importance in the Luquillo Mountains. On average, the soil is occupied by 200 individual earthworms per m2 [5

  13. Surface adsorption and bulk aggregation of cyclodextrins by computational molecular dynamics simulations as a function of temperature: α-CD vs β-CD.

    PubMed

    Mixcoha, Edgar; Campos-Terán, José; Piñeiro, Ángel

    2014-06-26

    The structural simplicity of native cyclodextrins (CDs) contrasts with their complex behavior in the bulk of aqueous solutions, mainly when they are combined with other cosolutes. Many scientific and industrial applications based on these molecules are supported only by empirical information. The lack of fundamental knowledge, which would allow one to rationally optimize many of these applications, is notable mainly at the solution/air interface. Basic information on phenomena such as the spontaneous adsorption of native CDs or on the structure of CD aggregates in the bulk solution is really scarce. In order to fill these gaps, a detailed computational study on the adsorption and aggregation of α- and β-CDs as a function of temperature is presented here. Our simulations reproduce, at atomic resolution, the experimentally observed much higher ability of β-CD to aggregate compared to that of α-CD at 298 K, as well as their dependence on temperature. The adsorption of both individual CDs and small CD aggregates (up to 20 molecules) to the solution/air interface is found to be negligible. 0.8 μs long trajectories of single CD molecules in aqueous solution reveal that the main differences in the behavior of both CDs are their flexibility, higher for β-CD, and the occupancy of individual intramolecular hydrogen bonds that is significantly longer for the same cyclodextrin. The aggregation pattern of α- and β-CDs is followed at the hundreds of ns time scale, allowing both the spontaneous self-assembly of cyclodextrins and their redistribution along the aggregates to be observed. This is the first attempt to study the adsorption and aggregation of native cyclodextrins by atomistic molecular dynamics simulations.

  14. Remarkable difference in catalytic performance of an organoamino-functionalized MCM-41-HPA composite with controlled site-isolation and site-aggregation

    NASA Astrophysics Data System (ADS)

    Chu, Xiaofeng; Le, Ying-Yi; Zhu, Quanjing; Fan, Kangnian; Dai, Wei-Lin

    2011-08-01

    The organoamino-functionalized mesoporous silicas with different distribution patterns—site-isolation or site-aggregation are prepared using post-grafting method. We have investigated the effects of the solvents and the catalytic reactivity of these catalysts. It is found that, using the polar ethanol as solvent, the catalytic center is site-isolated. Contrarily, the catalytic center is site-aggregated with the non-polar toluene. Characterization techniques, including transmission electron microscopy, nitrogen sorption experiments, thermogravimetric analysis, and ultraviolet-visible absorbance spectroscopy, demonstrate the most important dependencies of the distribution pattern on the polarity of solvent.

  15. Meta-analysis for aggregated survival data with competing risks: a parametric approach using cumulative incidence functions.

    PubMed

    Bonofiglio, Federico; Beyersmann, Jan; Schumacher, Martin; Koller, Michael; Schwarzer, Guido

    2016-09-01

    Meta-analysis of a survival endpoint is typically based on the pooling of hazard ratios (HRs). If competing risks occur, the HRs may lose translation into changes of survival probability. The cumulative incidence functions (CIFs), the expected proportion of cause-specific events over time, re-connect the cause-specific hazards (CSHs) to the probability of each event type. We use CIF ratios to measure treatment effect on each event type. To retrieve information on aggregated, typically poorly reported, competing risks data, we assume constant CSHs. Next, we develop methods to pool CIF ratios across studies. The procedure computes pooled HRs alongside and checks the influence of follow-up time on the analysis. We apply the method to a medical example, showing that follow-up duration is relevant both for pooled cause-specific HRs and CIF ratios. Moreover, if all-cause hazard and follow-up time are large enough, CIF ratios may reveal additional information about the effect of treatment on the cumulative probability of each event type. Finally, to improve the usefulness of such analysis, better reporting of competing risks data is needed. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Influence of denaturation and aggregation of β-lactoglobulin on its tryptic hydrolysis and the release of functional peptides.

    PubMed

    Leeb, Elena; Götz, Alexander; Letzel, Thomas; Cheison, Seronei Chelulei; Kulozik, Ulrich

    2015-11-15

    Whereas previous studies showed that thermal pre-treatment of whey proteins promote their enzymatic hydrolysis, to date no correlation between the conformation of denatured protein and the release of individual peptides has been considered. Hence, in this study total denaturation of β-lactoglobulin was performed at defined pH-values to enable the generation of different denatured particles. The denatured proteins were used as substrate for tryptic hydrolysis and the hydrolysis progress was characterised by the degree of hydrolysis (DH) and the release of functional peptides, detected using LC-ESI-TOF/MS. Denaturation and subsequent aggregation of β-lactoglobulin, induced by thermal treatment at pH 5.1, altered the DH slightly, whereas the release of investigated peptides was significantly decreased. Contrary, denaturation at pH 6.8 and 8.0 led to formation of non-native monomers and reduced the DH to 75%, but showed promoting as well as reducing effects on the release of peptides, depending on their location within the protein.

  17. In vitro canine platelet aggregation caused by Dirofilaria immitis extract

    PubMed Central

    TAKASHIMA, Yasuhiro; ONODA, Isako; CHIOU, Shin-Pin; KITOH, Katsuya

    2016-01-01

    Platelet function hyper-activity has been reported in Dirofilaria immitis (heartworm, HW)-infected dogs. Although the mechanism of increased platelet hyper-activity has not yet been elucidated, it is suggested to be mediated by unknown factors, which may be related to adult HW components. This study aims to determine whether adult male HW whole body extract induces canine platelet aggregation in vitro. The results indicate that HW extract caused an aggregation of canine platelets in a concentration-dependent manner. This aggregation ability of the HW extract was not mediated by the adenosine diphosphate receptor. In addition, the mechanisms of aggregation did not require cyclooxygenase-dependent pathways, and the aggregating activity of substances contained in the HW extract was heat stable; therefore, the active substances may be different from collagen. Furthermore, the platelet aggregating activity remained within the molecular weight (MW)≥100,000 fraction obtained by ultrafiltrating the HW extract. In contrast, the MW <100,000 fraction also had a platelet aggregation ability, but the aggregation pattern was reversible and the maximum extent decreased, compared with the MW≥100,000 fraction response. Our experiments have been conducted using a whole body extract from adult HWs to determine with certainty the aggregating activity of HW elements on canine platelets. More studies are necessary to evaluate the effects of the metabolic products released from live adult worms in pulmonary arteries and the symbiont bacterium Wolbachia-derived antigens on canine platelet aggregation. PMID:28049921

  18. In vitro canine platelet aggregation caused by Dirofilaria immitis extract.

    PubMed

    Takashima, Yasuhiro; Onoda, Isako; Chiou, Shin-Pin; Kitoh, Katsuya

    2017-02-28

    Platelet function hyper-activity has been reported in Dirofilaria immitis (heartworm, HW)-infected dogs. Although the mechanism of increased platelet hyper-activity has not yet been elucidated, it is suggested to be mediated by unknown factors, which may be related to adult HW components. This study aims to determine whether adult male HW whole body extract induces canine platelet aggregation in vitro. The results indicate that HW extract caused an aggregation of canine platelets in a concentration-dependent manner. This aggregation ability of the HW extract was not mediated by the adenosine diphosphate receptor. In addition, the mechanisms of aggregation did not require cyclooxygenase-dependent pathways, and the aggregating activity of substances contained in the HW extract was heat stable; therefore, the active substances may be different from collagen. Furthermore, the platelet aggregating activity remained within the molecular weight (MW)≥100,000 fraction obtained by ultrafiltrating the HW extract. In contrast, the MW <100,000 fraction also had a platelet aggregation ability, but the aggregation pattern was reversible and the maximum extent decreased, compared with the MW≥100,000 fraction response. Our experiments have been conducted using a whole body extract from adult HWs to determine with certainty the aggregating activity of HW elements on canine platelets. More studies are necessary to evaluate the effects of the metabolic products released from live adult worms in pulmonary arteries and the symbiont bacterium Wolbachia-derived antigens on canine platelet aggregation.

  19. Cephalopod ink: production, chemistry, functions and applications.

    PubMed

    Derby, Charles D

    2014-05-12

    One of the most distinctive and defining features of coleoid cephalopods-squid, cuttlefish and octopus-is their inking behavior. Their ink, which is blackened by melanin, but also contains other constituents, has been used by humans in various ways for millennia. This review summarizes our current knowledge of cephalopod ink. Topics include: (1) the production of ink, including the functional organization of the ink sac and funnel organ that produce it; (2) the chemical components of ink, with a focus on the best known of these-melanin and the biochemical pathways involved in its production; (3) the neuroecology of the use of ink in predator-prey interactions by cephalopods in their natural environment; and (4) the use of cephalopod ink by humans, including in the development of drugs for biomedical applications and other chemicals for industrial and other commercial applications. As is hopefully evident from this review, much is known about cephalopod ink and inking, yet more striking is how little we know. Towards closing that gap, future directions in research on cephalopod inking are suggested.

  20. Cephalopod Ink: Production, Chemistry, Functions and Applications

    PubMed Central

    Derby, Charles D.

    2014-01-01

    One of the most distinctive and defining features of coleoid cephalopods—squid, cuttlefish and octopus—is their inking behavior. Their ink, which is blackened by melanin, but also contains other constituents, has been used by humans in various ways for millennia. This review summarizes our current knowledge of cephalopod ink. Topics include: (1) the production of ink, including the functional organization of the ink sac and funnel organ that produce it; (2) the chemical components of ink, with a focus on the best known of these—melanin and the biochemical pathways involved in its production; (3) the neuroecology of the use of ink in predator-prey interactions by cephalopods in their natural environment; and (4) the use of cephalopod ink by humans, including in the development of drugs for biomedical applications and other chemicals for industrial and other commercial applications. As is hopefully evident from this review, much is known about cephalopod ink and inking, yet more striking is how little we know. Towards closing that gap, future directions in research on cephalopod inking are suggested. PMID:24824020

  1. Measuring ecosystem functioning of soil mega-aggregates produced by soil/litter mix-feeding animals

    NASA Astrophysics Data System (ADS)

    Kaneko, N.

    2009-04-01

    Some soil animals are soil/litter mix-feeders. They are known to produce long-lasting soil structures (e.g. casts and molting chamber), and these structures will modify resource availability and environmental conditions for plants and soil organisms. Good examples are epigeic Megascolecid earthworms (Uchida et al., 2004) and Xystodesmid millipeds (Toyota et al., 2006), both found in Japan. In this study we examined chemical, physical and biological properties of soil focusing on multi-functioning of aggregates made by these animals. Since 2003, we manipulated densities of epigeic earthworms in a field encloser (35 m2) (three replications) at a cool temperate forest in Japan. At a no-worm (NW) treatment, all the worms have been collected every year by hand. At the same place, we prepared a control treatment in an encloser (Closed control; CC) and outside the encloser (Open control; OC). We examined surface soil and plant growth after 5-years field manipulation of oak dominated forest. Growth of two Liliaceae forest floor herbs; Smilacina japonica and Polygonatum odoratum, and oak (Quercus crispula) seedlings and canopy oak trees were recorded. Reduction of aggregates after elimination of earthworms was observed in a field condition. The manipulation site showed decreased soil pH, Ca, Mg, and P concentration and total carbon storage was also reduced. There was a negative significant correlation between casts abundance and soil NH4-N, and a positive significance was observed between casts abundance and growth of S. japonica, and oak seedlings. Radial growth of canopy oak trees was decreased at NW treatment compared to CC and OC. Leaf N contents of oak seedling at NW were significantly lower in NW, but canopy oak trees did not show any difference in leaf-N. Although S. japonica and P. odoratum were both found in a same forest floor, S. japonica is known as nutrient limited plants in spring, whereas P. odoratum is light limited. Oak seedlings are depending early growth

  2. Inferring Aggregated Functional Traits from Metagenomic Data Using Constrained Non-negative Matrix Factorization: Application to Fiber Degradation in the Human Gut Microbiota

    PubMed Central

    Raguideau, Sébastien; Plancade, Sandra; Pons, Nicolas; Leclerc, Marion

    2016-01-01

    Whole Genome Shotgun (WGS) metagenomics is increasingly used to study the structure and functions of complex microbial ecosystems, both from the taxonomic and functional point of view. Gene inventories of otherwise uncultured microbial communities make the direct functional profiling of microbial communities possible. The concept of community aggregated trait has been adapted from environmental and plant functional ecology to the framework of microbial ecology. Community aggregated traits are quantified from WGS data by computing the abundance of relevant marker genes. They can be used to study key processes at the ecosystem level and correlate environmental factors and ecosystem functions. In this paper we propose a novel model based approach to infer combinations of aggregated traits characterizing specific ecosystemic metabolic processes. We formulate a model of these Combined Aggregated Functional Traits (CAFTs) accounting for a hierarchical structure of genes, which are associated on microbial genomes, further linked at the ecosystem level by complex co-occurrences or interactions. The model is completed with constraints specifically designed to exploit available genomic information, in order to favor biologically relevant CAFTs. The CAFTs structure, as well as their intensity in the ecosystem, is obtained by solving a constrained Non-negative Matrix Factorization (NMF) problem. We developed a multicriteria selection procedure for the number of CAFTs. We illustrated our method on the modelling of ecosystemic functional traits of fiber degradation by the human gut microbiota. We used 1408 samples of gene abundances from several high-throughput sequencing projects and found that four CAFTs only were needed to represent the fiber degradation potential. This data reduction highlighted biologically consistent functional patterns while providing a high quality preservation of the original data. Our method is generic and can be applied to other metabolic processes in

  3. Insights into the Structure and Metabolic Function of Microbes That Shape Pelagic Iron-Rich Aggregates (“Iron Snow”)

    PubMed Central

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B.; Neu, Thomas R.; Hettich, Robert L.

    2013-01-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates (“iron snow”) at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 108 copies g (dry weight)−1 in the acidic central lake basin (pH 3.3) to 4.0 × 1010 copies g (dry weight)−1 in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies. PMID:23645202

  4. Insights into the structure and metabolic function of microbes that shape pelagic iron-rich aggregates ("iron snow").

    PubMed

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B; Neu, Thomas R; Hettich, Robert L; Küsel, Kirsten

    2013-07-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates ("iron snow") at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 10(8) copies g (dry weight)(-1) in the acidic central lake basin (pH 3.3) to 4.0 × 10(10) copies g (dry weight)(-1) in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies.

  5. Insights into the Structure and Metabolic Function of Microbes That Shape Pelagic Iron-Rich Aggregates ( Iron Snow )

    SciTech Connect

    Lu, S; Chourey, Karuna; REICHE, M; Nietzsche, S; Shah, Manesh B; Hettich, Robert {Bob} L; Kusel, K

    2013-01-01

    Metaproteomics combined with total nucleic acid-based methods aided in deciphering the roles of microorganisms in the formation and transformation of iron-rich macroscopic aggregates (iron snow) formed in the redoxcline of an acidic lignite mine lake. Iron snow had high total bacterial 16S rRNA gene copies, with 2 x 109 copies g (dry wt)-1 in the acidic (pH 3.5) central lake basin and 4 x 1010 copies g (dry wt)-1 in the less acidic (pH 5.5) northern lake basin. Active microbial communities in the central basin were dominated by Alphaproteobacteria (36.6%) and Actinobacteria (21.4%), and by Betaproteobacteria (36.2%) in the northern basin. Microbial Fe-cycling appeared to be the dominant metabolism in the schwertmannite-rich iron snow, because cloning and qPCR assigned up to 61% of active bacteria as Fe-cycling bacteria (FeB). Metaproteomics revealed 70 unique proteins from central basin iron snow and 283 unique proteins from 43 genera from northern basin. Protein identification provided a glimpse into in situ processes, such as primary production, motility, metabolism of acidophilic FeB, and survival strategies of neutrophilic FeB. Expression of carboxysome shell proteins and RubisCO indicated active CO2 fixation by Fe(II) oxidizers. Flagellar proteins from heterotrophs indicated their activity to reach and attach surfaces. Gas vesicle proteins related to CO2-fixing Chlorobium suggested that microbes could influence iron snow sinking. We suggest that iron snow formed by autotrophs in the redoxcline acts as a microbial parachute, since it is colonized by motile heterotrophs during sinking which start to dissolve schwertmannite.

  6. Aggregation of polyglutamine-expanded ataxin-3 sequesters its specific interacting partners into inclusions: Implication in a loss-of-function pathology

    PubMed Central

    Yang, Hui; Li, Jing-Jing; Liu, Shuai; Zhao, Jian; Jiang, Ya-Jun; Song, Ai-Xin; Hu, Hong-Yu

    2014-01-01

    Expansion of polyglutamine (polyQ) tract may cause protein misfolding and aggregation that lead to cytotoxicity and neurodegeneration, but the underlying mechanism remains to be elucidated. We applied ataxin-3 (Atx3), a polyQ tract-containing protein, as a model to study sequestration of normal cellular proteins. We found that the aggregates formed by polyQ-expanded Atx3 sequester its interacting partners, such as P97/VCP and ubiquitin conjugates, into the protein inclusions through specific interactions both in vitro and in cells. Moreover, this specific sequestration impairs the normal cellular function of P97 in down-regulating neddylation. However, expansion of polyQ tract in Atx3 does not alter the conformation of its surrounding regions and the interaction affinities with the interacting partners, although it indeed facilitates misfolding and aggregation of the Atx3 protein. Thus, we propose a loss-of-function pathology for polyQ diseases that sequestration of the cellular essential proteins via specific interactions into inclusions by the polyQ aggregates causes dysfunction of the corresponding proteins, and consequently leads to neurodegeneration. PMID:25231079

  7. Functionality of probiotics - potential for product development.

    PubMed

    Dekker, James; Collett, Michael; Prasad, Jaya; Gopal, Pramod

    2007-01-01

    It is becoming increasingly accepted by consumers that live lactic acid bacteria do exert health benefits when eaten. In addition, it is also becoming recognised that not all probiotic bacteria are equal. It is now no longer just a question of providing sufficient numbers of viable bacteria in a product; industry must also provide proof of efficacy for each strain. In the early 1990s, Fonterra embarked on a programme to develop proprietary probiotic strains, and as a result, commercialised two strains, Bifidobacterium lactis HN019 and Lactobacillus rhamnosus HN001. Over the past decade, Fonterra has developed a significant body of peerreviewed published reports around these strains, including studies showing safety in animal and human trials, protection against pathogens such as Salmonella typhimurium and Escherichia coli O157:H7, modulation of human and animal immune markers at realistic dose rates, and efficacy in human clinical trials. Based on this work, HN019 and HN001 have been applied to several functional foods both by Fonterra (under the DR10 and DR20 brands, respectively) and by third parties (e.g. under the HOWARU brand by Danisco). While the 'gold standard' of proof of efficacy is a phase III clinical trial, ethical considerations as well as expense preclude the use of clinical trials as screening tools for probiotics. Therefore, biomarkers have to be employed to identify strains with probiotic utility, and to define the different positive health benefits of existing probiotic strains. However, as the mechanisms by which most probiotic bacteria exert their health benefits remain unclear, the question of which biomarkers accurately reflect efficacy in vivo remains unresolved. With recent technological advances, and the shift toward probiotics targeted to specific conditions, researchers are beginning to tease out how probiotic bacteria work, and it is this knowledge that will inform biomarker development and improve the ability to offer the market safe

  8. Functions of Carotenoid Metabolites and Breakdown Products

    NASA Astrophysics Data System (ADS)

    Britton, George

    It is not only intact carotenoids but also fragments of carotenoid molecules that have important natural functions and actions. The electron-rich polyene chain of the carotenoids is very susceptible to oxidative breakdown, which may be enzymic or non-enzymic. Central cleavage gives C20 compounds, retinoids, as described in Chapter 16. Cleavage at other positions gives smaller fragments, notably C10, C13 and C15 compounds that retain the carotenoid end group. The formation of these is described in Chapter 17 and in Volume 3, Chapter 4. Oxidative breakdown can also take place during storage, processing and curing of plant material, and the products contribute to the desired aroma/flavour properties of, for example, tea, wine and tobacco. The importance of vitamin A (C20) in animals is well known. Vitamin A deficiency is still a major concern in many parts of the world. It can lead to blindness and serious ill-health or death, especially in young children. Volatile smaller carotenoid fragments (`norisoprenoids') are widespread scent/flavour compounds in plants.

  9. Advanced-glycation-end-product-cholesterol-aggregated-protein accelerates the proliferation of mesangial cells mediated by transforming-growth-factor-beta 1 receptors and the ERK-MAPK pathway.

    PubMed

    Hirasawa, Yasushi; Sakai, Takayuki; Ito, Masanori; Yoshimura, Hiromitsu; Feng, Yibin; Nagamatsu, Tadashi

    2011-12-15

    Hyperglycemia and hyperlipidemia are considered critical to the development of diabetic nephropathy. The aim of this study is to clarify the effect of cholesterol on advanced-glycation-end-products and the mechanisms behind the advanced-glycation-end-product-cholesterol-aggregated bovine serum albumin (BSA)-induced proliferation of mesangial cells. Mesangial cells were treated with advanced-glycation-end-product-cholesterol-aggregated-BSA, and RNA and protein were isolated. Cholesterol caused a 1.5-fold increase in fluorescent intensity and 2-fold increase in advanced-glycation-end-products in vitro. Pyridoxamine, aminoguanidine, and N-acetyl-l-cycteine suppressed the production of advanced-glycation-end-product-cholesterol-aggregated-BSA. Advanced-glycation-end-product-cholesterol-BSA was analyzed by matrix-assisted-laser-desorption/ionization-time of flight mass spectrometry, and peaks were found to shift toward a higher mass. Advanced-glycation-end-product-cholesterol-aggregated-BSA induced overexpression of the mRNA of transforming growth factor-beta1, collagen type 1, collagen type 4 and receptor for advanced-glycation-end-products, and the proliferation of mesangial cells. The injection of advanced-glycation-end-product-cholesterol-aggregated-BSA caused glomerular changes and albuminuria in non-diabetic mice. A transforming-growth-factor-beta receptor 1 kinase inhibitor or Mitogen-activated-Protein-Kinase/Extracellular-Signal-regulated-Kinase kinase (ERK) inhibitor (U-0126) suppressed the proliferation of mesangial cells induced by advanced-glycation-end-product-cholesterol-aggregated-BSA dose-dependently. U-0126 inhibited the phosphorylation of ERK1/2 in advanced-glycation-end-product-cholesterol-aggregated-BSA treated mesangial cells. These findings suggested that cholesterol promotes the formation of advanced-glycation-end-products-protein and that advanced-glycation-end-product-cholesterol-aggregated protein stimulates mesangial cells to proliferate via

  10. Asymmetric Inheritance of Aggregated Proteins and Age Reset in Yeast Are Regulated by Vac17-Dependent Vacuolar Functions.

    PubMed

    Hill, Sandra Malmgren; Hao, Xinxin; Grönvall, Johan; Spikings-Nordby, Stephanie; Widlund, Per O; Amen, Triana; Jörhov, Anna; Josefson, Rebecca; Kaganovich, Daniel; Liu, Beidong; Nyström, Thomas

    2016-07-19

    Age can be reset during mitosis in both yeast and stem cells to generate a young daughter cell from an aged and deteriorated one. This phenomenon requires asymmetry-generating genes (AGGs) that govern the asymmetrical inheritance of aggregated proteins. Using a genome-wide imaging screen to identify AGGs in Saccharomyces cerevisiae, we discovered a previously unknown role for endocytosis, vacuole fusion, and the myosin-dependent adaptor protein Vac17 in asymmetrical inheritance of misfolded proteins. Overproduction of Vac17 increases deposition of aggregates into cytoprotective vacuole-associated sites, counteracts age-related breakdown of endocytosis and vacuole integrity, and extends replicative lifespan. The link between damage asymmetry and vesicle trafficking can be explained by a direct interaction between aggregates and vesicles. We also show that the protein disaggregase Hsp104 interacts physically with endocytic vesicle-associated proteins, such as the dynamin-like protein, Vps1, which was also shown to be required for Vac17-dependent sequestration of protein aggregates. These data demonstrate that two physiognomies of aging-reduced endocytosis and protein aggregation-are interconnected and regulated by Vac17.

  11. A nanoscale bio-inspired light-harvesting system developed from self-assembled alkyl-functionalized metallochlorin nano-aggregates

    NASA Astrophysics Data System (ADS)

    Ocakoglu, Kasim; Joya, Khurram S.; Harputlu, Ersan; Tarnowska, Anna; Gryko, Daniel T.

    2014-07-01

    Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The transparent Zn-chlorin nano-aggregates inside the alkyl-TiO2 modified AAO nano-channels have a diameter of ~120 nm in a 60 μm length channel. UV-Vis studies and fluorescence emission spectra further confirm the formation of the supramolecular ZnChl aggregates from monomer molecules inside the alkyl-functionalized nano-channels. Our results prove that the novel and unique method can be used to produce efficient and stable light-harvesting assemblies for effective solar energy capture through transparent and stable nano-channel ceramic materials modified with bio-mimetic molecular self-assembled nano-aggregates.Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The

  12. Proteins aggregation and human diseases

    NASA Astrophysics Data System (ADS)

    Hu, Chin-Kun

    2015-04-01

    Many human diseases and the death of most supercentenarians are related to protein aggregation. Neurodegenerative diseases include Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), frontotemporallobar degeneration, etc. Such diseases are due to progressive loss of structure or function of neurons caused by protein aggregation. For example, AD is considered to be related to aggregation of Aβ40 (peptide with 40 amino acids) and Aβ42 (peptide with 42 amino acids) and HD is considered to be related to aggregation of polyQ (polyglutamine) peptides. In this paper, we briefly review our recent discovery of key factors for protein aggregation. We used a lattice model to study the aggregation rates of proteins and found that the probability for a protein sequence to appear in the conformation of the aggregated state can be used to determine the temperature at which proteins can aggregate most quickly. We used molecular dynamics and simple models of polymer chains to study relaxation and aggregation of proteins under various conditions and found that when the bending-angle dependent and torsion-angle dependent interactions are zero or very small, then protein chains tend to aggregate at lower temperatures. All atom models were used to identify a key peptide chain for the aggregation of insulin chains and to find that two polyQ chains prefer anti-parallel conformation. It is pointed out that in many cases, protein aggregation does not result from protein mis-folding. A potential drug from Chinese medicine was found for Alzheimer's disease.

  13. Exposure to the Functional Bacterial Amyloid Protein Curli Enhances Alpha-Synuclein Aggregation in Aged Fischer 344 Rats and Caenorhabditis elegans

    PubMed Central

    Chen, Shu G.; Stribinskis, Vilius; Rane, Madhavi J.; Demuth, Donald R.; Gozal, Evelyne; Roberts, Andrew M.; Jagadapillai, Rekha; Liu, Ruolan; Choe, Kyonghwan; Shivakumar, Bhooma; Son, Francheska; Jin, Shunying; Kerber, Richard; Adame, Anthony; Masliah, Eliezer; Friedland, Robert P.

    2016-01-01

    Misfolded alpha-synuclein (AS) and other neurodegenerative disorder proteins display prion-like transmission of protein aggregation. Factors responsible for the initiation of AS aggregation are unknown. To evaluate the role of amyloid proteins made by the microbiota we exposed aged rats and transgenic C. elegans to E. coli producing the extracellular bacterial amyloid protein curli. Rats exposed to curli-producing bacteria displayed increased neuronal AS deposition in both gut and brain and enhanced microgliosis and astrogliosis compared to rats exposed to either mutant bacteria unable to synthesize curli, or to vehicle alone. Animals exposed to curli producing bacteria also had more expression of TLR2, IL-6 and TNF in the brain than the other two groups. There were no differences among the rat groups in survival, body weight, inflammation in the mouth, retina, kidneys or gut epithelia, and circulating cytokine levels. AS-expressing C. elegans fed on curli-producing bacteria also had enhanced AS aggregation. These results suggest that bacterial amyloid functions as a trigger to initiate AS aggregation through cross-seeding and also primes responses of the innate immune system. PMID:27708338

  14. Recombinant production of influenza hemagglutinin and HIV-1 GP120 antigenic peptides using a cleavable self-aggregating tag

    PubMed Central

    Xu, Wanghui; Zhao, Qing; Xing, Lei; Lin, Zhanglin

    2016-01-01

    The increasing demand for antigenic peptides in the development of novel serologic diagnostics and epitope-based vaccines requires rapid and reliable peptide synthesis techniques. Here we investigated a method for efficient recombinant expression and purification of medium- to large-sized antigenic peptides in E. coli. Previously we devised a streamlined protein expression and purification scheme based on a cleavable self-aggregating tag (cSAT), which comprised an intein molecule and a self-aggregating peptide ELK16. In this scheme, the target proteins were fused in the C-termini with cSAT and expressed as insoluble aggregates. After intein self-cleavage, target proteins were released into the soluble fraction with high yield and reasonable purity. We demonstrated the applicability of this scheme by preparing seven model viral peptides, with lengths ranging from 32 aa to 72 aa. By adding an N-terminal thioredoxin tag, we enhanced the yield of target peptides released from the aggregates. The purified viral peptides demonstrated high antigenic activities in ELISA and were successfully applied to dissecting the antigenic regions of influenza hemagglutinin. The cSAT scheme described here allows for the rapid and low-cost preparation of multiple antigenic peptides for immunological screening of a broad range of viral antigens. PMID:27808126

  15. Sensitive naked-eye detection of Hg2+ based on the aggregation and filtration of thymine functionalized vesicles caused by selective interaction between thymine and Hg2+.

    PubMed

    Ma, Xue; Sheng, Zhonghan; Jiang, Long

    2014-07-07

    We report a sensitive, selective and low-cost method for the naked-eye detection of Hg(2+). The principle is based on rapid interaction between functionalized PDA vesicles and Hg(2+), which leads to obvious aggregation of vesicles. Furthermore, using only a simple filtration process, without using any other color indicator or specialized equipment, a higher detection sensitivity for Hg(2+) (0.1 μM) than chromophoric colorimetric sensors (approximately 1-100 μM) was obtained.

  16. Aggregation and pH-temperature phase behavior for aggregates of an IgG2 antibody.

    PubMed

    Sahin, Erinc; Weiss, William F; Kroetsch, Andrew M; King, Kevin R; Kessler, R Kendall; Das, Tapan K; Roberts, Christopher J

    2012-05-01

    Monomer unfolding and thermally accelerated aggregation kinetics to produce soluble oligomers or insoluble macroscopic aggregates were characterized as a function of pH for an IgG2 antibody using differential scanning calorimetry (DSC) and size-exclusion chromatography (SEC). Aggregate size was quantified via laser light scattering, and aggregate solubility via turbidity and visual inspection. Interestingly, nonnative oligomers were soluble at pH 5.5 above approximately 15°C, but converted reversibly to visible/insoluble particles at lower temperatures. Lower pH values yielded only soluble aggregates, whereas higher pH resulted in insoluble aggregates, regardless of the solution temperature. Unlike the growing body of literature that supports the three-endotherm model of IgG1 unfolding in DSC, the results here also illustrate limitations of that model for other monoclonal antibodies. Comparison of DSC with monomer loss (via SEC) from samples during thermal scanning indicates that the least conformationally stable domain is not the most aggregation prone, and that a number of the domains remain intact within the constituent monomers of the resulting aggregates. This highlights continued challenges with predicting a priori which domain(s) or thermal transition(s) is(are) most relevant for product stability with respect to aggregation.

  17. Isolation and Characterisation of Bacteriocin
and Aggregation-Promoting Factor Production in
Lactococcus lactis ssp. lactis BGBM50 Strain

    PubMed Central

    Mirkovic, Nemanja; Radulovic, Zorica; Uzelac, Gordana; Lozo, Jelena; Obradovic, Dragojlo; Topisirovic, Ljubisa

    2015-01-01

    Summary Lactococcus lactis ssp. lactis BGBM50, a producer of lactococcin G and aggregation-promoting factor, was isolated from selected lactic acid bacteria taken from semi-hard cheese traditionally produced in the village Žanjic, Montenegro. Strain BGBM50 harbours a number of plasmids of different sizes. Plasmid curing experiments showed that genes for bacteriocin production are located on pBM140, a plasmid 140 kb in length. PCR analysis with primers specific for lactococcin Q and G genes gave fragment of the expected size. In addition, after plasmid curing of strain BGBM50, different derivatives with altered phenotypes were obtained, among them BGBM50-34 strain, which retained bacteriocin synthesis but had enhanced aggregation ability. PMID:27904354

  18. Attributing Effects of Aqueous C60 Nano-Aggregates to Tetrahydrofuran Decomposition Products in Larval Zebrafish by Assessment of Gene Expression

    PubMed Central

    Henry, Theodore B.; Menn, Fu-Min; Fleming, James T.; Wilgus, John; Compton, Robert N.; Sayler, Gary S.

    2007-01-01

    Background C60 is a highly insoluble nanoparticle that can form colloidal suspended aggregates in water, which may lead to environmental exposure in aquatic organisms. Previous research has indicated toxicity from C60 aggregate; however, effects could be because of tetrahydrofuran (THF) vehicle used to prepare aggregates. Objective Our goal was to investigate changes in survival and gene expression in larval zebrafish Danio rerio after exposure to aggregates of C60 prepared by two methods: a) stirring and sonication of C60 in water (C60–water); and b) suspension of C60 in THF followed by rotovaping, resuspension in water, and sparging with nitrogen gas (THF–C60). Results Survival of larval zebrafish was reduced in THF–C60 and THF–water but not in C60–water. The greatest differences in gene expression were observed in fish exposed to THF–C60 and most (182) of these genes were similarly expressed in fish exposed to THF–water. Significant up-regulation (3- to 7-fold) of genes involved in controlling oxidative damage was observed after exposure to THF–C60 and THF–water. Analyses of THF–C60 and THF–water by gas chromatography–mass spectrometry did not detect THF but found THF oxidation products γ-butyrolactone and tetrahydro-2-furanol. Toxicity of γ-butyrolactone (72-hr lethal concentration predicted to kill 50% was 47 ppm) indicated effects in THF treatments can result from γ-butyrolactone toxicity. Conclusion This research is the first to link toxic effects directly to a THF degradation product (γ-butyrolactone) rather than to C60 and may explain toxicity attributed to C60 in other investigations. The present work was first presented at the meeting “Overcoming Obstacles to Effective Research Design in Nanotoxicology” held 24–26 April 2006 in Cambridge, Massachusetts, USA. PMID:17637923

  19. Integrated Information Support System (IISS). Volume 5. Common Data Model Subsystem. Part 29. Data Aggregators Product Specification.

    DTIC Science & Technology

    1985-11-01

    Role Boeing Military Aircraft Reviewer. Company (EMAC) D. Appleton Company Responsible for IDEF support, (DACOM) state-of-the-art literature search...SRTCDR SORTING THE COMMON DATA RECORD TRMSRT TERMINATE THE SORTING 3-12 Milt X - PS 620141320 1 November 1985 DATA AGGREGATORS Module List Module Name...OF THE RECORD "INPUT-FILE". REVISED 15 APR 1985 MODIFIED 2 MAY 1985 MODIFIED 9 MAY 1985 ARGUMENTS: INPUT-FILE - RECRD TEMP-FILE-NAME - DSPLY [ X (30

  20. Heavy Flavour Production as Probe of Gluon Sivers Function

    NASA Astrophysics Data System (ADS)

    Godbole, Rohini M.; Kaushik, Abhiram; Misra, Anuradha; Rawoot, Vaibhav; Sonawane, Bipin

    2017-03-01

    Heavy flavour production like J/ψ and D-meson production in scattering of electrons/unpolarized protons off polarized proton target offer promising probes to investigate gluon Sivers function. In this talk, I will summarize our recent work on transverse single spin asymmetry in J/ψ -production and D-meson production in p p^\\uparrow scattering using a generalized parton model approach. We compare predictions obtained using different models of gluon Sivers function within this approach and then, taking into account the transverse momentum dependent evolution of the unpolarized parton distribution functions and gluon Sivers function, we study the effect of evolution on asymmetry.

  1. Variation is function: Are single cell differences functionally important?: Testing the hypothesis that single cell variation is required for aggregate function.

    PubMed

    Dueck, Hannah; Eberwine, James; Kim, Junhyong

    2016-02-01

    There is a growing appreciation of the extent of transcriptome variation across individual cells of the same cell type. While expression variation may be a byproduct of, for example, dynamic or homeostatic processes, here we consider whether single-cell molecular variation per se might be crucial for population-level function. Under this hypothesis, molecular variation indicates a diversity of hidden functional capacities within an ensemble of identical cells, and this functional diversity facilitates collective behavior that would be inaccessible to a homogenous population. In reviewing this topic, we explore possible functions that might be carried by a heterogeneous ensemble of cells; however, this question has proven difficult to test, both because methods to manipulate molecular variation are limited and because it is complicated to define, and measure, population-level function. We consider several possible methods to further pursue the hypothesis that variation is function through the use of comparative analysis and novel experimental techniques.

  2. Computational Interpretations of Analysis via Products of Selection Functions

    NASA Astrophysics Data System (ADS)

    Escardó, Martín; Oliva, Paulo

    We show that the computational interpretation of full comprehension via two well-known functional interpretations (dialectica and modified realizability) corresponds to two closely related infinite products of selection functions.

  3. [Melatonin production in thrombocytes and their functional activity in patients with aspirin asthma].

    PubMed

    Evsiukova, E V; Muraia, E V; Zubzhitskaia, L B; Kveshnoĭ, I M

    2007-01-01

    The aim of the investigation was to study melatonin production in thrombocytes and their functional activity in correlation with 6-sulfatoximelatonin (6-SOM) urinary excretion in patients with aspirin-induced bronchial asthma (AIBA). Forty-three patients with bronchial asthma (BA) were examined. The main group consisted of 26 AIBA patients; the comparison group consisted of 17 BA patients with no intolerance to aspirin or other non-steroidal anti-inflammatory drugs; 30 practically healthy individuals constituted the control group. The study found no melatonin production in thrombocytes of AIBA patients: only 13.0 +/- 1.3% of platelets expressed melatonin, while in healthy people 97.7 +/- 0.6% of the cells did. Besides, daytime urinary excretion of 6-SOM, the main melatonin metabolite, was lower in AIBA patients. Lower daytime and higher nighttime melatonin production in AIBA patients correlated with the acceleration of the 1st phase and increased intensity of thrombocyte aggregation, which evidences high thrombocyte reactivity to the inducing agent. The presence of a pathologic reaction of thrombocytes to exogenous melatonin, manifesting by changes in the 1st stage of aggregation, suggests the presence of pathology in thrombocyte membrane-receptor complex and the calcium homeostasis of the cell, which determines constant activation and the participation of thrombocytes in the development of asthmatic syndrome.

  4. Aggregate exposure modelling of zinc pyrithione in rinse-off personal cleansing products using a person-orientated approach with market share refinement.

    PubMed

    Tozer, Sarah A; Kelly, Seamus; O'Mahony, Cian; Daly, E J; Nash, J F

    2015-09-01

    Realistic estimates of chemical aggregate exposure are needed to ensure consumer safety. As exposure estimates are a critical part of the equation used to calculate acceptable "safe levels" and conduct quantitative risk assessments, methods are needed to produce realistic exposure estimations. To this end, a probabilistic aggregate exposure model was developed to estimate consumer exposure from several rinse off personal cleansing products containing the anti-dandruff preservative zinc pyrithione. The model incorporates large habits and practices surveys, containing data on frequency of use, amount applied, co-use along with market share, and combines these data at the level of the individual based on subject demographics to better estimate exposure. The daily-applied exposure (i.e., amount applied to the skin) was 3.79 mg/kg/day for the 95th percentile consumer. The estimated internal dose for the 95th percentile exposure ranged from 0.01-1.29 μg/kg/day after accounting for retention following rinsing and dermal penetration of ZnPt. This probabilistic aggregate exposure model can be used in the human safety assessment of ingredients in multiple rinse-off technologies (e.g., shampoo, bar soap, body wash, and liquid hand soap). In addition, this model may be used in other situations where refined exposure assessment is required to support a chemical risk assessment.

  5. Water Production Functions For High Plains Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining water supplies is the critical resource issue for irrigated agriculture in the High Plains and much of the western U.S. Farmers need to maximize production per unit water consumed to remain economically viable and sustain irrigated agriculture. The Agricultural Research Service (ARS) Wat...

  6. The influence of erythrocyte aggregation on induced platelet aggregation.

    PubMed

    Ott, C; Lardi, E; Schulzki, T; Reinhart, W H

    2010-01-01

    Red blood cells (RBCs) affect platelet aggregation in flowing blood (primary hemostasis). We tested the hypothesis that RBC aggregation could influence platelet aggregation. RBC aggregation was altered in vitro by: (i) changing plasma aggregatory properties with 3.7 g% dextran 40 (D40), 3.0 g% dextran 70 (D70) or 1.55 g% dextran 500 (D500); (ii) changing RBC aggregatory properties by incubating RBCs in 50 mU/ml neuraminidase for 60 min (reduction of the surface sialic acid content, thus reducing electrostatic repulsion) and subsequent RBC resuspension in platelet rich plasma (PRP) containing 1 g% dextran 70. RBC aggregation was assessed with the sedimentation rate (ESR). Platelet aggregation was measured: (i) in flowing whole blood with a platelet function analyzer PFA-100(R), which simulates in vivo conditions with RBCs flowing in the center and platelets along the wall, where they adhere to collagen and aggregate; and (ii) in a Chrono-log 700 Aggregometer, which measures changes of impedance by platelet aggregation in whole blood or changes in light transmission in PRP. We found that RBC aggregation increased with increasing molecular weight of dextran (ESR: 4 +/- 3 mm/h, 34 +/- 14 mm/h and 89 +/- 23 mm/hfor D40, D70 and D500, respectively, p < 0.0001) and with neuraminidase-treated RBCs (76 +/- 27 mm/h vs 27 +/- 8 mm/h, respectively, p < 0.0001). Platelet aggregation measured in whole blood under flow conditions (PFA-100) and without flow (Chronolog Aggregometer) was not affected by RBC aggregation. Our data suggest that RBC aggregation does not affect platelet aggregation in vitro and plays no role in primary hemostasis.

  7. Pareto-Optimality, Efficiency Analysis and Empirical Production Functions.

    DTIC Science & Technology

    1983-05-01

    General, 120, 3, 253-281 (1957). 15. Fenchel , W., Convex Sets , Cones and Functions , Princeton University Press, Princeton, N.J. (1953). 16. Fbrsund, F...concave, piecewise linear function on DE" Proof: A necessary and sufficient condition for fr(x) to be concave is that its hypograph is a convex set (cf...34 production function . The work of R. Shephard [18], [19] under severe restrictions on the mathematical structure of production possibility sets and cost

  8. Influence of soot aggregate size and internal multiple scattering on LII signal and the absorption function variation with wavelength determined by the TEW-LII method

    NASA Astrophysics Data System (ADS)

    Yon, J.; Therssen, E.; Liu, F.; Bejaoui, S.; Hebert, D.

    2015-05-01

    Laser-induced incandescence (LII) is a powerful and robust optical method for in situ determination of soot volume fraction and/or soot absorption/emission properties in flames and engine exhaust. The laser-induced signal is interpreted as thermal emission based on the Planck law. Up to now, the evaluation and interpretation of LII signal have been largely based on contributions from isolated primary particles that are assumed much smaller than wavelengths. In the present paper, the morphology, wavelength, and aggregate size-dependent effects of multiple scattering within fractal soot aggregates on their absorption and emission cross sections are taken into account in the evaluation of LII signal by proposing correction terms to the traditional model. The impact of accounting for the correction to soot aggregate emission due to multiple scattering on LII signal and on the two excitation wavelength-induced incandescence method for inferring the soot absorption function, E(m), is discussed. For wavelengths shorter than 532 nm, E(m, λ)/E(m, 1064 nm) increases more significantly with decreasing wavelength. For wavelengths longer than 532 nm, the wavelength dependence of E(m, λ)/E(m, 1064 nm) becomes very small and can be neglected. The proposed corrections, along with the soot morphology, are applied to re-analyze the experimental data of Bejaoui et al. (Appl Phys B Lasers Opt, 116:313, 2014) for deriving the relative soot absorption function variation with wavelength at different locations in a rich premixed methane flat flame at atmospheric pressure. The present analysis showed that the soot absorption function varies with the height above the burner exit and can be correlated with the degree of soot maturation.

  9. Warm-up exercise suppresses platelet-eosinophil/neutrophil aggregation and platelet-promoted release of eosinophil/neutrophil oxidant products enhanced by severe exercise in men.

    PubMed

    Wang, Jong-Shyan; Yen, Hsiang-Ling; Yang, Chuen-Mao

    2006-03-01

    Heterotypic platelet-eosinophil/neutrophil aggregation and subsequent release of eosinophil/neutrophil oxidant products contribute to pathogenesis of conditions such as asthma and inflammatory bowel diseases. This study investigates whether warmup exercise (WUE) affects platelet-eosinophil/neutrophil interaction mediated by high-intensity exercise (HIE). Twenty-three healthy sedentary men performed on three occasions light-intensity exercise (LIE, 40%VO(2 max) for 40 min) and HIE (80%VO(2 max) for 40 min) with and without WUE (40%VO(2 max) for 20 min). Before and immediately after exercise, platelet-eosinophil and platelet-neutrophil aggregation (PEA and PNA), reactive oxygen species production of eosinophils and neutrophils (EROS and NROS) enhanced by platelets, and adhesion molecule expression on platelets, eosinophils, and neutrophils were measured. The results of this study demonstrated that HIE enhanced PEA, PNA, and platelet-induced EROS and NROS, was accompanied by increased expressions of Mac-1 on eosinophils and neutrophils and P-selectin on platelets at 5 dyne/cm(2) of shear stress, 100 microg/ml lipopolysaccharide, and 1 microM N-formylmethionyl- leucyl-phenylalanine treatments, whereas the enhancement of HIE on platelet-eosinophil/neutrophil interaction was suppressed by WUE. Conversely, LIE significantly reduced PEA and PNA, suppressed platelet-induced EROS and NROS, and down-regulated eosinophil/neutrophil Mac-1 and platelet P-selectin expressions under various stimuli and shear flow conditions. Moreover, these effects were more pronounced in platelet interaction with eosinophils than with neutrophils. It is concluded that HIE enhances hetero-aggregation, adhesion molecules expressions, and subsequent oxidative bursts mediated by platelets and eosinophils/neutrophils, this effect diminishes after WUE. However, LIE minimizes the risk of thromboinflammation.

  10. Screening of biotechnical parameters for production of bovine inter-subspecies embryonic chimeras by the aggregation of tetraploid Bos indicus and diploid crossbred Bos taurus embryos.

    PubMed

    Razza, Eduardo M; Satrapa, Rafael A; Emanuelli, Isabele P; Barros, Ciro M; Nogueira, Marcelo F G

    2016-03-01

    The aggregation of a tetraploid zebu embryo (Bos indicus, a thermotolerant breed) with a diploid taurine embryo (Bos taurus, a thermosensitive breed) should create a complete taurine fetus, whose extra-embryonic components, e.g., the chorion, is derived mainly from the zebu embryo. These zebu-derived extra-embryonic components may interact positively with the taurine embryo/fetus during pregnancy in a tropical environment. We tested different parameters for the production of tetraploid Nelore (Bos indicus) embryos to be combined via aggregation with crossbred Bos taurus (diploid) embryos in order to produce viable chimeric blastocysts. Bovine (Bos indicus or crossbred Bos taurus) embryos were produced in vitro according to standard procedures. Two-cell Bos indicus embryos were submitted to electrofusion with varying numbers of pulses (1 or 2), voltages (0.4, 0.5, 0.75, 1.0, 1.4 and 5.0 kV/cm) and time (20, 25, 50 and 60 μs) to produce tetraploid embryos. Electrofused embryos were cultured with crossbred non-fused embryos to form chimeras that developed until the blastocyst stage. The best fusion parameter was 0.75 kV/cm for 60 μs. Four chimeric blastocysts (tetraploid Nelore with diploid crossbred Holstein) were formed after 31 attempts in 4 replicates (13%). We established an optimal procedure for the production of tetraploid Bos indicus (4n) embryos and embryonic chimeras by aggregation of crossbred Bos taurus (2n) with Bos indicus (4n) embryos. This technique would be valid in applied research, by producing exclusively taurine calves, but with placental elements from the Bos indicus breed, following transfer of these chimeras into recipient cows.

  11. Bioprocess development for mass production of size-controlled human pluripotent stem cell aggregates in stirred suspension bioreactor.

    PubMed

    Abbasalizadeh, Saeed; Larijani, Mehran Rezaei; Samadian, Azam; Baharvand, Hossein

    2012-11-01

    Current protocols for the scalable suspension culture of human pluripotent stem cells (hPSCs) are limited by multiple biological and technical challenges that need to be addressed before their use in clinical trials. To overcome these challenges, we have developed a novel bioprocess platform for large-scale expansion of human embryonic and induced pluripotent stem cell lines as three-dimensional size-controlled aggregates. This novel bioprocess utilizes the stepwise optimization of both static and dynamic suspension culture conditions. After screening eight xeno-free media in static suspension culture and optimizing single-cell passaging in dynamic conditions, the scale-up from a static to a dynamic suspension culture in the stirred bioreactor resulted in a two- to threefold improvement in expansion rates, as measured by cell counts and metabolic activity. We successfully produced size-specific aggregates through optimization of bioreactor hydrodynamic conditions by using combinations of different agitation rates and shear protectant concentrations. The expansion rates were further improved by controlling oxygen concentration at normoxic conditions, and reached a maximum eightfold increase for both types of hPSCs. Subsequently, we demonstrated a simple and rapid scale-up strategy that produced clinically relevant numbers of hPSCs (∼2×10(9) cells) over a 1-month period by the direct transfer of "suspension-adapted frozen cells" to a stirred suspension bioreactor. We omitted the required preadaptation passages in the static suspension culture. The cells underwent proliferation over multiple passages in the demonstrated xeno-free dynamic suspension culture while maintaining their self-renewal capabilities, as determined by marker expressions and in vitro spontaneous differentiation. In conclusion, suspension culture protocols of hPSCs could be used to mass produce homogenous and pluripotent undifferentiated cells by identification and optimization of key bioprocess

  12. Dispersion and functionalization of nanoparticles synthesized by gas aggregation source: Opening new routes towards the fabrication of nanoparticles for bio-medicine

    PubMed Central

    Oprea, B.; Martínez, L.; Román, E.; Vanea, E.; Simon, S.; Huttel, Y.

    2015-01-01

    The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, that is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source, using a Fe50B50 target, and their further dispersion and functionalization with polyethileneglycol (PEG). A characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivitiy measurements of these PEG functionalized nanoparticles assessed their effectiveness as contrast agents for Magnetic Resonance Imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine. PMID:26640032

  13. Systematic Product Development of Control and Diagnosis Functionalities

    NASA Astrophysics Data System (ADS)

    Stetter, R.; Simundsson, A.

    2017-01-01

    In the scientific field of systematic product development a wide range of helpful methods, guidelines and tools were generated and published in recent years. Until now little special attention was given to design guidelines aiming at supporting product development engineers to design products that allow and support control or diagnosis functions. The general trend to ubiquitous computing and the first development steps towards cognitive systems as well as a general trend toward higher product safety, reliability and reduced total cost of ownership (TCO) in many engineering fields lead to a higher importance of control and diagnosis. In this paper a first attempt is made to formulate general valid guidelines how products can be developed in order to allow and to achieve effective and efficient control and diagnosis. The guidelines are elucidated on the example of an automated guided vehicle. One main concern of this paper is the integration of control and diagnosis functionalities into the development of complete systems which include mechanical, electrical and electronic subsystems. For the development of such systems the strategies, methods and tools of systematic product development have attracted significant attention during the last decades. Today, the functionality and safety of most products is to a large degree dependent on control and diagnosis functionalities. Still, there is comparatively little research concentrating on the integration of the development of these functionalities into the overall product development processes. The paper starts with a background describing Systematic Product Development. The second section deals with the product development of the sample product. The third part clarifies the notions monitoring, control and diagnosis. The following parts summarize some insights and formulate first hypotheses concerning control and diagnosis in Systematic Product Development.

  14. Pathophysiological importance of aggregated damaged proteins.

    PubMed

    Höhn, Annika; Jung, Tobias; Grune, Tilman

    2014-06-01

    Reactive oxygen species (ROS) are formed continuously in the organism even under physiological conditions. If the level of ROS in cells exceeds the cellular defense capacity, components such as RNA/DNA, lipids, and proteins are damaged and modified, thus affecting the functionality of organelles as well. Proteins are especially prominent targets of various modifications such as oxidation, glycation, or conjugation with products of lipid peroxidation, leading to the alteration of their biological function, nonspecific interactions, and the production of high-molecular-weight protein aggregates. To ensure the maintenance of cellular functions, two proteolytic systems are responsible for the removal of oxidized and modified proteins, especially the proteasome and organelles, mainly the autophagy-lysosomal systems. Furthermore, increased protein oxidation and oxidation-dependent impairment of proteolytic systems lead to an accumulation of oxidized proteins and finally to the formation of nondegradable protein aggregates. Accordingly, the cellular homeostasis cannot be maintained and the cellular metabolism is negatively affected. Here we address the current knowledge of protein aggregation during oxidative stress, aging, and disease.

  15. Ecological Production Functions: A Theoretical and Practical Exploration

    EPA Science Inventory

    Ecological production functions characterize relationships between ecosystem condition, management practices, and the delivery of economically valuable ecosystem services. Many in the ecosystem service research community view ecological research directed toward developing ecolog...

  16. Defining the functional traits that drive bacterial decomposer community productivity.

    PubMed

    Evans, Rachael; Alessi, Anna M; Bird, Susannah; McQueen-Mason, Simon J; Bruce, Neil C; Brockhurst, Michael A

    2017-03-21

    Microbial communities are essential to a wide range of ecologically and industrially important processes. To control or predict how these communities function, we require a better understanding of the factors which influence microbial community productivity. Here, we combine functional resource use assays with a biodiversity-ecosystem functioning (BEF) experiment to determine whether the functional traits of constituent species can be used to predict community productivity. We quantified the abilities of 12 bacterial species to metabolise components of lignocellulose and then assembled these species into communities of varying diversity and composition to measure their productivity growing on lignocellulose, a complex natural substrate. A positive relationship between diversity and community productivity was caused by a selection effect whereby more diverse communities were more likely to contain two species that significantly improved community productivity. Analysis of functional traits revealed that the observed selection effect was primarily driven by the abilities of these species to degrade β-glucan. Our results indicate that by identifying the key functional traits underlying microbial community productivity we could improve industrial bioprocessing of complex natural substrates.The ISME Journal advance online publication, 21 March 2017; doi:10.1038/ismej.2017.22.

  17. Crop water production functions for grain sorghum and winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Productivity of water-limited cropping systems can be reduced by untimely distribution of water as well as cold and heat stress. The objective was to develop relationships among weather parameters, water use, and grain productivity to produce functions forecasting grain yields of grain sorghum and w...

  18. Arginine–glycine–aspartic acid–polyethylene glycol–polyamidoamine dendrimer conjugate improves liver-cell aggregation and function in 3-D spheroid culture

    PubMed Central

    Chen, Zhanfei; Lian, Fen; Wang, Xiaoqian; Chen, Yanling; Tang, Nanhong

    2016-01-01

    The polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine–glycine–aspartic acid (RGD) peptide. Our studies demonstrate that RGD–polyethylene glycol (PEG)–PAMAM conjugates can promote singly floating hepatic cells to aggregate together in a sphere-like growth with a weak reactive oxygen species. Moreover, RGD-PEG-PAMAM conjugates can activate the AKT–MAPK pathway in hepatic cells to promote cell proliferation and improve basic function and ammonia metabolism. Together, our data support the hepatocyte sphere treated by RGD-PEG-PAMAM conjugates as a potential source of hepatic cells for a biological artificial liver system. PMID:27621619

  19. Arginine-glycine-aspartic acid-polyethylene glycol-polyamidoamine dendrimer conjugate improves liver-cell aggregation and function in 3-D spheroid culture.

    PubMed

    Chen, Zhanfei; Lian, Fen; Wang, Xiaoqian; Chen, Yanling; Tang, Nanhong

    The polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine-glycine-aspartic acid (RGD) peptide. Our studies demonstrate that RGD-polyethylene glycol (PEG)-PAMAM conjugates can promote singly floating hepatic cells to aggregate together in a sphere-like growth with a weak reactive oxygen species. Moreover, RGD-PEG-PAMAM conjugates can activate the AKT-MAPK pathway in hepatic cells to promote cell proliferation and improve basic function and ammonia metabolism. Together, our data support the hepatocyte sphere treated by RGD-PEG-PAMAM conjugates as a potential source of hepatic cells for a biological artificial liver system.

  20. Guarana (Paullinia cupana Mart.) prevents β-amyloid aggregation, generation of advanced glycation-end products (AGEs), and acrolein-induced cytotoxicity on human neuronal-like cells.

    PubMed

    Bittencourt, Leonardo da Silva; Zeidán-Chuliá, Fares; Yatsu, Francini Kiyono Jorge; Schnorr, Carlos Eduardo; Moresco, Karla Suzana; Kolling, Eduardo Antônio; Gelain, Daniel Pens; Bassani, Valquiria Linck; Moreira, José Cláudio Fonseca

    2014-11-01

    Advanced glycation end-products (AGEs) are considered potent molecules capable of promoting neuronal cell death and participating in the development of neurodegenerative disorders such as Alzheimer's disease (AD). Previous studies have shown that AGEs exacerbate β-amyloid (Aβ) aggregation and AGE-related cross-links are also detected in senile plaques. Acrolein (ACR) is an α, β-unsaturated aldehyde found in the environment and thermally processed foods, which can additionally be generated through endogenous metabolism. The role of ACR in AD is widely accepted in the literature. Guarana (Paullinia cupana Mart.) is popularly consumed by the population in Brazil, mainly for its stimulant activity. In the present study, we showed that guarana (10, 100, and 1000 µg/mL) is able to prevent protein glycation, β-amyloid aggregation, in vitro methylglyoxal, glyoxal, and ACR (20 μM)-induced toxicity on neuronal-like cells (SH-SY5Y). Since these are considered typical AD pathological hallmarks, we propose that guarana may deserve further research as a potential therapeutic agent in such a neurodegenerative disease.

  1. Thioredoxin-80 is a product of alpha-secretase cleavage that inhibits amyloid-beta aggregation and is decreased in Alzheimer's disease brain

    PubMed Central

    Gil-Bea, Francisco; Akterin, Susanne; Persson, Torbjörn; Mateos, Laura; Sandebring, Anna; Avila-Cariño, Javier; Gutierrez-Rodriguez, Angel; Sundström, Erik; Holmgren, Arne; Winblad, Bengt; Cedazo-Minguez, Angel

    2012-01-01

    Thioredoxin-1 (Trx1) is an endogenous dithiol reductant and antioxidant that was shown to be decreased in Alzheimer's disease (AD) neurons. A truncated form of Trx1, thioredoxin 80 (Trx80), was reported to be secreted from monocytes having cytokine activity. Here, we show that Trx80 is present in human brain in an aggregated form. Trx80 localizes mainly to neurons and is dramatically decreased in AD brains. Trx80 levels in cerebrospinal fluid (CSF) correlate with those of the classical AD biomarkers amyloid-β (Aβ) 1–42 and total tau. Moreover, Trx80 measurements in CSF discriminate between patients with stable mild cognitive impairment, prodomal AD and mild AD. We report that ADAM10 and 17, two α-secretases processing the Aβ precursor protein, are responsible for Trx80 generation. In contrast to the periphery, Trx80 has no pro-inflammatory effects in glia, either by itself or in combination with Aβ or apolipoprotein E. Instead, Trx80 inhibits Aβ(1–42) aggregation and protects against its toxicity. Thus, a reduction in Trx80 production would result in increased Aβ polymerization and enhanced neuronal vulnerability. Our data suggest that a deficit in Trx80 could participate in AD pathogenesis. PMID:22933306

  2. Inhibition of Wnt signaling induces amyloidogenic processing of amyloid precursor protein and the production and aggregation of Amyloid-β (Aβ)42 peptides.

    PubMed

    Tapia-Rojas, Cheril; Burgos, Patricia V; Inestrosa, Nibaldo C

    2016-12-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder and the most frequent cause of dementia in the aged population. According to the amyloid hypothesis, the amyloid-β (Aβ) peptide plays a key role in the pathogenesis of AD. Aβ is generated from the amyloidogenic processing of amyloid precursor protein and can aggregate to form oligomers, which have been described as a major synaptotoxic agent in neurons. Dysfunction of Wnt signaling has been linked to increased Aβ formation; however, several other studies have argued against this possibility. Herein, we use multiple experimental approaches to confirm that the inhibition of Wnt signaling promoted the amyloidogenic proteolytic processing of amyloid precursor protein. We also demonstrate that inhibiting Wnt signaling increases the production of the Aβ42 peptide, the Aβ42 /Aβ40 ratio, and the levels of Aβ oligomers such as trimers and tetramers. Moreover, we show that activating Wnt signaling reduces the levels of Aβ42 and its aggregates, increases Aβ40 levels, and reduces the Aβ42 /Aβ40 ratio. Finally, we show that the protective effects observed in response to activation of the Wnt pathway rely on β-catenin-dependent transcription, which is demonstrated experimentally via the expression of various 'mutant forms of β-catenin'. Together, our findings indicate that loss of the Wnt signaling pathway may contribute to the pathogenesis of AD.

  3. Integral representations for products of Airy functions Part 2. Cubic products

    NASA Astrophysics Data System (ADS)

    Reid, W. H.

    Integral representations are obtained for some cubic products of the Airy functions Ai(z) and Bi(z). These integral representations are of the Laplace contour type but they involve the modified Bessel functions of order 16. From these results it is then possible to evaluate a number of definite integrals involving such cubic products.

  4. Study by XPS of the chlorination of proteins aggregated onto tin dioxide during electrochemical production of hypochlorous acid

    NASA Astrophysics Data System (ADS)

    Debiemme-Chouvy, Catherine; Haskouri, Sanae; Cachet, Hubert

    2007-04-01

    In solution, hypochlorous acid (HOCl) reacts with organic matter and notably with protein side-chains. In this study, HOCl was produced by an electrochemical way, by oxidation of chloride ions at a transparent tin dioxide electrode in the presence of a protein, the bovine serum albumin (BSA). A thick irregular layer is formed at the electrode when HOCl is produced at the SnO 2 surface. Indeed, SEM analyses show that an important deposit is formed during the anodic polarization of SnO 2 in the presence of chloride ions and proteins. Actually, two phenomena take place on the one hand the chlorination of the proteins due to the reaction of HOCl with some protein side-chains and on the other hand the aggregation of proteins onto the SnO 2 surface. The present X-ray photoelectron spectroscopy study points out the cross-linking of BSA molecules via formation of inter molecular sulfonamide groups. It also shows that the BSA chlorination is due on the one hand to the formation of sulfonyl chloride groups (-SO 2Cl) and on the other hand to formation of chloramine groups ( lbond2 N-Cl). The Cl2p and S2p photo-peak intensities allowed us to quantify the chloramines. It is found that, one BSA entity immobilized onto the SnO 2 surface contains about 50 chloramine groups.

  5. Virus-induced aggregates in infected cells.

    PubMed

    Moshe, Adi; Gorovits, Rena

    2012-10-17

    During infection, many viruses induce cellular remodeling, resulting in the formation of insoluble aggregates/inclusions, usually containing viral structural proteins. Identification of aggregates has become a useful diagnostic tool for certain viral infections. There is wide variety of viral aggregates, which differ by their location, size, content and putative function. The role of aggregation in the context of a specific virus is often poorly understood, especially in the case of plant viruses. The aggregates are utilized by viruses to house a large complex of proteins of both viral and host origin to promote virus replication, translation, intra- and intercellular transportation. Aggregated structures may protect viral functional complexes from the cellular degradation machinery. Alternatively, the activation of host defense mechanisms may involve sequestration of virus components in aggregates, followed by their neutralization as toxic for the host cell. The diversity of virus-induced aggregates in mammalian and plant cells is the subject of this review.

  6. Effect of curcumin-associated and lipid ligand-functionalized nanoliposomes on aggregation of the Alzheimer's Aβ peptide.

    PubMed

    Taylor, Mark; Moore, Susan; Mourtas, Spyridon; Niarakis, Anna; Re, Francesca; Zona, Cristiano; La Ferla, Barbara; Nicotra, Francesco; Masserini, Massimo; Antimisiaris, Sophia G; Gregori, Maria; Allsop, David

    2011-10-01

    The effect of various types of nanoliposomes (associated with curcumin, phosphatidic acid, cardiolipin, or GM1 ganglioside) on the aggregation of the amyloid-β(1-42) (Aβ(1-42)) peptide was investigated. Nanoliposomes incorporating curcumin (curcumin-liposomes) were prepared by adding curcumin in the lipid phase during liposome preparation, whereas curcumin surface-decorated liposomes were prepared by using a curcumin-lipid conjugate (lipid-S-curcumin liposomes) or by attaching a curcumin derivative on preformed liposomes by click chemistry (click-curcumin liposomes). The lipid ligands (phosphatidic acid, cardiolipin, or GM1) were also incorporated into nanoliposomes during their formation. All nanoliposomes with curcumin, or the curcumin derivative, were able to inhibit the formation of fibrillar and/or oligomeric Aβ in vitro. Of the three forms of curcumin liposomes tested, the click-curcumin type was by far the most effective. Liposomes with lipid ligands only inhibited Aβ fibril and oligomer formation at a very high ratio of liposome to peptide. Curcumin-based liposomes could be further developed as a novel treatment for Alzheimer's disease.

  7. Gadolinium-functionalized aggregation-induced emission dots as dual-modality probes for cancer metastasis study.

    PubMed

    Li, Kai; Ding, Dan; Prashant, Chandrasekharan; Qin, Wei; Yang, Chang-Tong; Tang, Ben Zhong; Liu, Bin

    2013-12-01

    Understanding the localization and engraftment of tumor cells at postintravasation stage of metastasis is of high importance in cancer diagnosis and treatment. Advanced fluorescent probes and facile methodologies for cell tracing play a key role in metastasis studies. In this work, we design and synthesize a dual-modality imaging dots with both optical and magnetic contrast through integration of a magnetic resonance imaging reagent, gadolinium(III), into a novel long-term cell tracing probe with aggregation-induced emission (AIE) in far-red/near-infrared region. The obtained fluorescent-magnetic AIE dots have both high fluorescence quantum yield (25%) and T1 relaxivity (7.91 mM(-1) s(-1) ) in aqueous suspension. After further conjugation with a cell membrane penetrating peptide, the dual-modality dots can be efficiently internalized into living cells. The gadolinium(III) allows accurate quantification of biodistribution of cancer cells via intraveneous injection, while the high fluorescence provides engraftment information of cells at single cellular level. The dual-modality AIE dots show obvious synergistic advantages over either single imaging modality and hold great promises in advanced biomedical studies.

  8. Identification of an educational production function for diverse technologies

    NASA Technical Reports Server (NTRS)

    Mcclung, R. L.

    1977-01-01

    Production function analysis used to estimate the cost effectiveness of three alternative technologies in higher education: traditional instruction, instructional television, and computer-assisted instruction is presented. Criteria and selection of a functional form are outlined and a general discussion of variable selection and measurement is presented.

  9. Liver tissue engineering based on aggregate assembly: efficient formation of endothelialized rat hepatocyte aggregates and their immobilization with biodegradable fibres.

    PubMed

    Pang, Y; Montagne, K; Shinohara, M; Komori, K; Sakai, Y

    2012-12-01

    To realize long-term in vitro culture of hepatocytes at a high density while maintaining a high hepatic function for aggregate-based liver tissue engineering, we report here a novel culture method whereby endothelialized rat hepatocyte aggregates were formed using a PDMS microwell device and cultured in a perfusion bioreactor by introducing spacers between aggregates to improve oxygen and nutrient supply. Primary rat hepatocyte aggregates around 100 µm in diameter coated with human umbilical vein endothelial cells were spontaneously and quickly formed after 12 h of incubation, thanks to the continuous supply of oxygen by diffusion through the PDMS honeycomb microwell device. Then, the recovered endothelialized rat hepatocyte aggregates were mixed with biodegradable poly-l-lactic acid fibres in suspension and packed into a PDMS-based bioreactor. Perfusion culture of 7 days was successfully achieved with more than 73.8% cells retained in the bioreactor. As expected, the fibres acted as spacers between aggregates, which was evidenced from the enhanced albumin production and more spherical morphology compared with fibre-free packing. In summary, this study shows the advantages of using PDMS-based microwells to form heterotypic aggregates and also demonstrates the feasibility of spacing tissue elements for improving oxygen and nutrient supply to tissue engineering based on modular assembly.

  10. Combatting Ionic Aggregation using Dielectric Forces Combining Modeling/Simulation and Experimental Results to Explain End-capping of Primary Amine Functionalized Polystyrene

    SciTech Connect

    Messman, Jamie M; Goswami, Monojoy; Pickel, Deanna L; Uhrig, David; Sumpter, Bobby G; Mays, Jimmy

    2011-01-01

    Chain-end functionalization of living poly(styryl)lithium using 1-(3-bromopropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilacyclo-pentane (BTDP) to generate primary amine end-functionalized polystyrene was investigated using high vacuum anionic polymerization techniques. 13C NMR spectroscopy and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) were used to evaluate polymer end-groups and demonstrated that quantitative amine functionalized polymer was attained under appropriate reaction conditions. In general, the polymerization of styrene was conducted in benzene and the end-capping reaction was performed by adding tetrahydrofuran (THF) to the reaction prior to the addition of BTDP in THF at room temperature. Results indicated that approximately 20% THF by volume is required to obtain 100% end-capping free from side reactions. When too little or no THF was present, side reactions such as lithium halogen exchange followed by Wurtz coupling resulted in unfunctionalized head-to-head dimer as well as other byproducts. Modeling and simulation of the solvent effects using hybrid methods (the so-called QM/MM method) suggest that THF effectively dissociated the anionic chain-end aggregation, thereby resulting in the desired primary amine functionalized polymer. Molecular dynamics (MD) simulations were conducted to develop an understanding of the physics of counterions involved in the end-functionalization process.

  11. The Effect of Florida's Bright Futures Program on College Enrollment and Degree Production: An Aggregated-Level Analysis

    ERIC Educational Resources Information Center

    Zhang, Liang; Hu, Shouping; Sensenig, Victor

    2013-01-01

    In this study, we investigate the impact of the Bright Futures Scholarship Program on college enrollment and degree production in Florida by using IPEDS enrollment, migration, and completion data. Results suggest large and significant enrollment effects at Florida's public 4- and 2-year institutions, for both full-time and part-time enrollment.…

  12. Oligomeric baroeffect and gas aggregation states

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1992-01-01

    The baroeffect is analyzed to include a gas that aggregates into higher-order polymers or oligomers. The resulting pressure change is found to vary independently of the molecular weight of the gas components and to depend only on the aggregation or oligomeric order of the gas. With increasing aggregation, diffusive slip velocities are found to increase. The calculations are extended to include general counterdiffusion of two distinct aggregation states (k-, j-mer) for the gas, and the pressure change is derived as a function that is independent of both molecular weight and the absolute aggregation. The only parameter that determines the baroeffect is the ratio of aggregated states, beta = k/j. For gases that reversibly aggregate, possible oscillatory behavior and complex dynamics for pressure are discussed. Gas aggregation may play a role for low-temperature crystal-growth conditions in which vapor concentrations of one (or more) species are high.

  13. The global landscape of cognition: hierarchical aggregation as an organizational principle of human cortical networks and functions

    PubMed Central

    Taylor, P.; Hobbs, J. N.; Burroni, J.; Siegelmann, H. T.

    2015-01-01

    Though widely hypothesized, limited evidence exists that human brain functions organize in global gradients of abstraction starting from sensory cortical inputs. Hierarchical representation is accepted in computational networks, and tentatively in visual neuroscience, yet no direct holistic demonstrations exist in vivo. Our methods developed network models enriched with tiered directionality, by including input locations, a critical feature for localizing representation in networks generally. Grouped primary sensory cortices defined network inputs, displaying global connectivity to fused inputs. Depth-oriented networks guided analyses of fMRI databases (~17,000 experiments;~1/4 of fMRI literature). Formally, we tested whether network depth predicted localization of abstract versus concrete behaviors over the whole set of studied brain regions. For our results, new cortical graph metrics, termed network-depth, ranked all databased cognitive function activations by network-depth. Thus, we objectively sorted stratified landscapes of cognition, starting from grouped sensory inputs in parallel, progressing deeper into cortex. This exposed escalating amalgamation of function or abstraction with increasing network-depth, globally. Nearly 500 new participants confirmed our results. In conclusion, data-driven analyses defined a hierarchically ordered connectome, revealing a related continuum of cognitive function. Progressive functional abstraction over network depth may be a fundamental feature of brains, and is observed in artificial networks. PMID:26669858

  14. Work function analysis of vegetarian entrée production.

    PubMed

    Maloney, S; Zolber, K; Burke, K; Connell, B; Shavlik, G

    1986-02-01

    Data on labor time for food production can be used as an effective management tool. It is essential for foodservice managers to know how labor time is being used (1). A continuous time study was conducted to determine total labor time for the production of eight vegetarian entrées in a hospital foodservice system. Two work areas were observed: the ingredient assembly area and the cooks' production area. Times were recorded by work function to identify how labor time was distributed. Results showed (a) observed frequency for each work function, (b) time expended in seconds per portion for each work function, (c) percentage distribution of labor time by work function, (d) total time for each employee involved in entrée production, and (e) percentage of total time in which each employee was involved in the production of each entrée. Total labor time varied by type of entrée, ranging from 39.97 to 19.33 seconds per portion. Entrées with the highest labor time required the largest amount of hand labor. A one-way analysis of variance indicated significant differences in mean labor time among the eight vegetarian entrées for direct labor time (p = .0009), and total labor time (p = .0018). No significant differences were found among entrées for indirect labor or delay time.

  15. Premature red blood cells have decreased aggregation and enhanced aggregability.

    PubMed

    Arbell, D; Orkin, B; Bar-Oz, B; Barshtein, G; Yedgar, S

    2008-06-01

    Preterm infants are highly susceptible to ischemic damage. This damage is most obvious in the brain, retina, and gastrointestinal tract. Studies focusing on the rheological properties of premature red blood cells (pRBCs) have consistently shown minimal or no RBC aggregation. Previously, measurements of pRBC aggregation kinetics indicated that specific plasma properties are responsible for the decreased RBC aggregation observed in the neonates, but that their specific RBC properties do not affect it. However, the strength of interaction in the pRBC aggregates as a function of medium composition has not been tested. In our previous research, we described clinically relevant parameters, that is, the aggregate resistance to disaggregation by flow. With the help of a cell flow property analyzer (CFA), we can monitor RBC aggregation by direct visualization of its dynamics during flow. We used the CFA to examine pRBC (from 9 premature babies) in the natural plasma and in PBS buffer supplemented with dextran (500 kDa) to distinguish between RBC intrinsic-cellular and plasma factors. pRBCs suspended in the native plasma showed minimal or no aggregation in comparison to normal adult RBC. When we transferred pRBCs from the same sample to the dextran solution, enhanced resistance to disaggregation by flow was apparent.

  16. Applications of aggregation theory to sustainability assessment

    DOE PAGES

    Pollesch, N.; Dale, V. H.

    2015-04-01

    In order to aid in transition towards operations that promote sustainability goals, researchers and stakeholders use sustainability assessments. Although assessments take various forms, many utilize diverse sets of indicators that can number anywhere from two to over 2000. Indices, composite indicators, or aggregate values are used to simplify high dimensional and complex data sets and to clarify assessment results. Although the choice of aggregation function is a key component in the development of the assessment, there are few examples to be found in literature to guide appropriate aggregation function selection. This paper develops a connection between the mathematical study ofmore » aggregation functions and sustainability assessment in order to aid in providing criteria for aggregation function selection. Relevant mathematical properties of aggregation functions are presented and interpreted. Lastly, we provide cases of these properties and their relation to previous sustainability assessment research. Examples show that mathematical aggregation properties can be used to address the topics of compensatory behavior and weak versus strong sustainability, aggregation of data under varying units of measurements, multiple site multiple indicator aggregation, and the determination of error bounds in aggregate output for normalized and non-normalized indicator measures.« less

  17. Applications of aggregation theory to sustainability assessment

    SciTech Connect

    Pollesch, N.; Dale, V. H.

    2015-04-01

    In order to aid in transition towards operations that promote sustainability goals, researchers and stakeholders use sustainability assessments. Although assessments take various forms, many utilize diverse sets of indicators that can number anywhere from two to over 2000. Indices, composite indicators, or aggregate values are used to simplify high dimensional and complex data sets and to clarify assessment results. Although the choice of aggregation function is a key component in the development of the assessment, there are few examples to be found in literature to guide appropriate aggregation function selection. This paper develops a connection between the mathematical study of aggregation functions and sustainability assessment in order to aid in providing criteria for aggregation function selection. Relevant mathematical properties of aggregation functions are presented and interpreted. Lastly, we provide cases of these properties and their relation to previous sustainability assessment research. Examples show that mathematical aggregation properties can be used to address the topics of compensatory behavior and weak versus strong sustainability, aggregation of data under varying units of measurements, multiple site multiple indicator aggregation, and the determination of error bounds in aggregate output for normalized and non-normalized indicator measures.

  18. Modeling of the Gross Regional Product on the Basis of Production Functions

    ERIC Educational Resources Information Center

    Sadovin, Nikolay S.; Kokotkina, Tatiana N.; Barkalova, Tatiana G.; Tsaregorodsev, Evgeny I.

    2016-01-01

    The article is devoted to elaboration and construction of a static model of macroeconomics in which economics is considered as an unstructured holistic unit, the input of which receives the resources, and the output is the result of the functioning of economics in the form of gross domestic product or gross regional product. Resources are…

  19. Lower-Extremity Functional Electrical Stimulation Decreases Platelet Aggregation and Blood Coagulation in Persons With Chronic Spinal Cord Injury: A Pilot Study

    PubMed Central

    Kahn, Nighat N; Feldman, Susan P; Bauman, William A

    2010-01-01

    Background: Individuals with spinal cord injury (SCI) develop premature cardiovascular disease. Regular exercise reduces the incidence and symptoms of cardiovascular disease in able-bodied individuals; these salutary effects of exercise have not been documented in persons with SCI. Objective: To evaluate the effects of functional electrical stimulation leg cycle ergometry (FES-LCE) exercise training on platelet aggregation and blood coagulation in persons with SCI. Participants: Subjects (n  =  14) with stable chronic (>1 year) paraplegia (T1–T10) or tetraplegia (C4–C8). Methods: Blood samples were collected before and after the first and eighth sessions (2 sessions per week for 4 weeks) of FES exercise. Results: Platelet aggregation was inhibited by 20% after the first session and by 40% (P < 0.001) after the eighth session. Thrombin activity was unchanged after the first session (10.7 ± 0.85 s to 10.43 ± 0.56 s) and decreased after the eighth session (12.5 ± 1.98 s to 11.1 ± 1.7 s; P < 0.0003). Antithrombin III activity increased after the first (103.8% ± 8.9% to 110% ± 6.9%; P < 0.0008) and eighth sessions (107.8% ± 12.1% to 120.4% ± 13.1%; P < 0.0001). Cyclic adenosine monophosphate increased after the first (9.9% ± 2.5% to 15.8% ± 3%; P < 0.001) and eighth sessions (17.8% ± 4.2% to 36.5% ± 7.6%; P < 0.0001). After the eighth session, factors V and X increased significantly (88% ± 27% to 103% ± 23%, P < 0.0001; 100% ± 40% to 105% ± 7%, P < 0.01, respectively); factors VII and VIII and fibrinogen did not change significantly. A significant reduction in platelet activation/aggregation was demonstrated in response to FES-LCE. The decrease in thrombin level was caused by the simultaneous increase in antithrombin activity. Conclusion: These findings provide new insight into the potential protective effects of FES-LCE against the risk of cardiovascular disease. PMID:20486534

  20. Employing bacterial microcompartment technology to engineer a shell-free enzyme-aggregate for enhanced 1,2-propanediol production in Escherichia coli.

    PubMed

    Lee, Matthew J; Brown, Ian R; Juodeikis, Rokas; Frank, Stefanie; Warren, Martin J

    2016-07-01

    Bacterial microcompartments (BMCs) enhance the breakdown of metabolites such as 1,2-propanediol (1,2-PD) to propionic acid. The encapsulation of proteins within the BMC is mediated by the presence of targeting sequences. In an attempt to redesign the Pdu BMC into a 1,2-PD synthesising factory using glycerol as the starting material we added N-terminal targeting peptides to glycerol dehydrogenase, dihydroxyacetone kinase, methylglyoxal synthase and 1,2-propanediol oxidoreductase to allow their inclusion into an empty BMC. 1,2-PD producing strains containing the fused enzymes exhibit a 245% increase in product formation in comparison to un-tagged enzymes, irrespective of the presence of BMCs. Tagging of enzymes with targeting peptides results in the formation of dense protein aggregates within the cell that are shown by immuno-labelling to contain the vast majority of tagged proteins. It can therefore be concluded that these protein inclusions are metabolically active and facilitate the significant increase in product formation.

  1. Identification of a response regulator involved in surface attachment, cell-cell aggregation, exopolysaccharide production and virulence in the plant pathogen Xylella fastidiosa.

    PubMed

    Voegel, Tanja M; Doddapaneni, Harshavardhan; Cheng, Davis W; Lin, Hong; Stenger, Drake C; Kirkpatrick, Bruce C; Roper, M Caroline

    2013-04-01

    Xylella fastidiosa, the causal agent of Pierce's disease of grapevine, possesses several two-component signal transduction systems that allow the bacterium to sense and respond to changes in its environment. Signals are perceived by sensor kinases that autophosphorylate and transfer the phosphate to response regulators (RRs), which direct an output response, usually by acting as transcriptional regulators. In the X. fastidiosa genome, 19 RRs were found. A site-directed knockout mutant in one unusual RR, designated XhpT, composed of a receiver domain and a histidine phosphotransferase output domain, was constructed. The resulting mutant strain was analysed for changes in phenotypic traits related to biofilm formation and gene expression using microarray analysis. We found that the xhpT mutant was altered in surface attachment, cell-cell aggregation, exopolysaccharide (EPS) production and virulence in grapevine. In addition, this mutant had an altered transcriptional profile when compared with wild-type X. fastidiosa in genes for several biofilm-related traits, such as EPS production and haemagglutinin adhesins.

  2. Cytosine beta-D-arabinofuranoside used as a paradigm modifier to increase production of tau aggregates in a cellular model of tauopathy.

    PubMed

    Ko, Li-Wen; Kulathingal, Jayanarayan G; Yen, Shu-Hui C

    2007-01-01

    Intraneuronal deposition of filamentous tau is a hallmark of Alzheimer's disease (AD) and related tauopathies. We developed previously a cellular model recapitulating such tau anomaly and demonstrated therein consistent production of 70-kD tau. Importantly, the 70-kD species appears to derive from tau fragments with carboxy-terminal truncation and is larger than intact tau in size, suggesting the oligomeric nature in its assembly from tau. To generate the 70-kD tau in sufficient quantity for its characterization at the molecular level, we explored and demonstrated herein that cytosine beta-D-arabinofuranoside is a useful paradigm modifier to increase production of the 70-kD tau. Such oligomeric tau was enriched thereafter by immunoprecipitation to remove tau species with intact carboxy-terminus. Two-dimensional gel electrophoresis revealed that the 70-kD tau has an isoelectric point of 5.8-6.0. Future elucidation of key aggregates will provide valuable insights into the natural history of neurofibrillary degeneration and identify novel targets to develop therapeutic interventions.

  3. Functionality of alternative protein in gluten-free product development.

    PubMed

    Deora, Navneet Singh; Deswal, Aastha; Mishra, Hari Niwas

    2015-07-01

    Celiac disease is an immune-mediated disease triggered in genetically susceptible individuals by ingested gluten from wheat, rye, barley, and other closely related cereal grains. The current treatment for celiac disease is life-long adherence to a strict gluten-exclusion diet. The replacement of gluten presents a significant technological challenge, as it is an essential structure-building protein, which is necessary for formulating high-quality baked goods. A major limitation in the production of gluten-free products is the lack of protein functionality in non-wheat cereals. Additionally, commercial gluten-free mixes usually contain only carbohydrates, which may significantly limit the amount of protein in the diet. In the recent past, various approaches are attempted to incorporate protein-based ingredients and to modify the functional properties for gluten-free product development. This review aims to the highlight functionality of the alternative protein-based ingredients, which can be utilized for gluten-free product development both functionally as well as nutritionally.

  4. Equality of Educational Opportunity Quantified: A Production Function Approach.

    ERIC Educational Resources Information Center

    Summers, Anita A.; Wolfe, Barbara L.

    This paper discusses a statistical analysis of the impact on student learning of socioeconomic characteristics, certain aspects of the school environment, and the amount of educational resources expanded on students. It is felt that the analysis is quite similar to what economists do when they estimate production functions for films; but that…

  5. Development of US EPA's Ecological Production Function Library

    EPA Science Inventory

    US EPA is developing a library of ecological production functions (EPFs) to help communities plan for sustainable access to ecosystem goods and services (EGS). Several databases already compile information about the value of EGS. However, they focus on static representations of...

  6. Functional and Behavioral Product Information Representation and Consistency Validation for Collaboration in Product Lifecycle Activities

    ERIC Educational Resources Information Center

    Baysal, Mehmet Murat

    2012-01-01

    Information models that represent the function, assembly and behavior of artifacts are critical in the conceptual development of a product and its evaluation. Much research has been conducted in this area; however, existing models do not relate function, behavior and structure in a comprehensive and consistent way. In this work, NIST's Core…

  7. Joint pricing and production management: a geometric programming approach with consideration of cubic production cost function

    NASA Astrophysics Data System (ADS)

    Sadjadi, Seyed Jafar; Hamidi Hesarsorkh, Aghil; Mohammadi, Mehdi; Bonyadi Naeini, Ali

    2014-08-01

    Coordination and harmony between different departments of a company can be an important factor in achieving competitive advantage if the company corrects alignment between strategies of different departments. This paper presents an integrated decision model based on recent advances of geometric programming technique. The demand of a product considers as a power function of factors such as product's price, marketing expenditures, and consumer service expenditures. Furthermore, production cost considers as a cubic power function of outputs. The model will be solved by recent advances in convex optimization tools. Finally, the solution procedure is illustrated by numerical example.

  8. Biosynthesis and Function of Polyacetylenes and Allied Natural Products

    PubMed Central

    Minto, Robert E.; Blacklock, Brenda J.

    2008-01-01

    Polyacetylenic natural products are a substantial class of often unstable compounds containing a unique carbon-carbon triple bond functionality, that are intriguing for their wide variety of biochemical and ecological functions, economic potential, and surprising mode of biosynthesis. Isotopic tracer experiments between 1960 and 1990 demonstrated that the majority of these compounds are derived from fatty acid and polyketide precursors. During the past decade, research into the metabolism of polyacetylenes has swiftly advanced, driven by the cloning of the first genes responsible for polyacetylene biosynthesis in plants, moss, fungi, and actinomycetes, and the initial characterization of the gene products. The current state of knowledge of the biochemistry and molecular genetics of polyacetylenic secondary metabolic pathways will be presented together with an up-to-date survey of new terrestrial and marine natural products, their known biological activities, and a discussion of their likely metabolic origins. PMID:18387369

  9. Functions of the gene products of Escherichia coli.

    PubMed Central

    Riley, M

    1993-01-01

    A list of currently identified gene products of Escherichia coli is given, together with a bibliography that provides pointers to the literature on each gene product. A scheme to categorize cellular functions is used to classify the gene products of E. coli so far identified. A count shows that the numbers of genes concerned with small-molecule metabolism are on the same order as the numbers concerned with macromolecule biosynthesis and degradation. One large category is the category of tRNAs and their synthetases. Another is the category of transport elements. The categories of cell structure and cellular processes other than metabolism are smaller. Other subjects discussed are the occurrence in the E. coli genome of redundant pairs and groups of genes of identical or closely similar function, as well as variation in the degree of density of genetic information in different parts of the genome. PMID:7508076

  10. Star product, discrete Wigner functions, and spin-system tomograms

    NASA Astrophysics Data System (ADS)

    Adam, P.; Andreev, V. A.; Isar, A.; Man'ko, V. I.; Man'ko, M. A.

    2016-03-01

    We develop the star-product formalism for spin states and consider different methods for constructing operator systems forming sets of dequantizers and quantizers, establishing a relation between them. We study the physical meaning of the operator symbols related to them. Quantum tomograms can also serve as operator symbols. We show that the possibility to express discrete Wigner functions in terms of measurable quantities follows because these functions can be related to quantum tomograms. We investigate the physical meaning of tomograms and spin-system tomogram symbols, which they acquire in the framework of the star-product formalism. We study the structure of the sum kernels, which can be used to express the operator symbols, calculated using different sets of dequantizers and also arising in calculating the star product of operator symbols, in terms of one another.

  11. Coherent and incoherent ultrasound backscatter from cell aggregates.

    PubMed

    de Monchy, Romain; Destrempes, François; Saha, Ratan K; Cloutier, Guy; Franceschini, Emilie

    2016-09-01

    The effective medium theory (EMT) was recently developed to model the ultrasound backscatter from aggregating red blood cells [Franceschini, Metzger, and Cloutier, IEEE Trans. Ultrason. Ferroelectr. Freq. Control 58, 2668-2679 (2011)]. The EMT assumes that aggregates can be treated as homogeneous effective scatterers, which have effective properties determined by the aggregate compactness and the acoustical characteristics of the cells and the surrounding medium. In this study, the EMT is further developed to decompose the differential backscattering cross section of a single cell aggregate into coherent and incoherent components. The coherent component corresponds to the squared norm of the average scattering amplitude from the effective scatterer, and the incoherent component considers the variance of the scattering amplitude (i.e., the mean squared norm of the fluctuation of the scattering amplitude around its mean) within the effective scatterer. A theoretical expression for the incoherent component based on the structure factor is proposed and compared with another formulation based on the Gaussian direct correlation function. This theoretical improvement is assessed using computer simulations of ultrasound backscatter from aggregating cells. The consideration of the incoherent component based on the structure factor allows us to approximate the simulations satisfactorily for a product of the wavenumber times the aggregate radius krag around 2.

  12. Injury profile SIMulator, a Qualitative aggregative modelling framework to predict injury profile as a function of cropping practices, and abiotic and biotic environment. II. Proof of concept: design of IPSIM-wheat-eyespot.

    PubMed

    Robin, Marie-Hélène; Colbach, Nathalie; Lucas, Philippe; Montfort, Françoise; Cholez, Célia; Debaeke, Philippe; Aubertot, Jean-Noël

    2013-01-01

    IPSIM (Injury Profile SIMulator) is a generic modelling framework presented in a companion paper. It aims at predicting a crop injury profile as a function of cropping practices and abiotic and biotic environment. IPSIM's modelling approach consists of designing a model with an aggregative hierarchical tree of attributes. In order to provide a proof of concept, a model, named IPSIM-Wheat-Eyespot, has been developed with the software DEXi according to the conceptual framework of IPSIM to represent final incidence of eyespot on wheat. This paper briefly presents the pathosystem, the method used to develop IPSIM-Wheat-Eyespot using IPSIM's modelling framework, simulation examples, an evaluation of the predictive quality of the model with a large dataset (526 observed site-years) and a discussion on the benefits and limitations of the approach. IPSIM-Wheat-Eyespot proved to successfully represent the annual variability of the disease, as well as the effects of cropping practices (Efficiency = 0.51, Root Mean Square Error of Prediction = 24%; bias = 5.0%). IPSIM-Wheat-Eyespot does not aim to precisely predict the incidence of eyespot on wheat. It rather aims to rank cropping systems with regard to the risk of eyespot on wheat in a given production situation through ex ante evaluations. IPSIM-Wheat-Eyespot can also help perform diagnoses of commercial fields. Its structure is simple and permits to combine available knowledge in the scientific literature (data, models) and expertise. IPSIM-Wheat-Eyespot is now available to help design cropping systems with a low risk of eyespot on wheat in a wide range of production situations, and can help perform diagnoses of commercial fields. In addition, it provides a proof of concept with regard to the modelling approach of IPSIM. IPSIM-Wheat-Eyespot will be a sub-model of IPSIM-Wheat, a model that will predict injury profile on wheat as a function of cropping practices and the production situation.

  13. Protein Aggregation Profile of the Bacterial Cytosol

    PubMed Central

    de Groot, Natalia S.; Ventura, Salvador

    2010-01-01

    Background Protein misfolding is usually deleterious for the cell, either as a consequence of the loss of protein function or the buildup of insoluble and toxic aggregates. The aggregation behavior of a given polypeptide is strongly influenced by the intrinsic properties encoded in its sequence. This has allowed the development of effective computational methods to predict protein aggregation propensity. Methodology/Principal Findings Here, we use the AGGRESCAN algorithm to approximate the aggregation profile of an experimental cytosolic Escherichia coli proteome. The analysis indicates that the aggregation propensity of bacterial proteins is associated with their length, conformation, location, function, and abundance. The data are consistent with the predictions of other algorithms on different theoretical proteomes. Conclusions/Significance Overall, the study suggests that the avoidance of protein aggregation in functional environments acts as a strong evolutionary constraint on polypeptide sequences in both prokaryotic and eukaryotic organisms. PMID:20195530

  14. The functionality of plum ingredients in meat products: a review.

    PubMed

    Jarvis, Nathan; O'Bryan, Corliss A; Ricke, Steven C; Crandall, Philip G

    2015-04-01

    Dried plums (prunes) have been marketed to consumers for consumption directly from the package as a convenient snack and have been reported to have broad health benefits. Only recently have fractionated, dried plum ingredients been investigated for their functionality in food and feed products. Dried plum puree, dried plum fiber, dried plum powder, dried plum concentrate, and fresh plum concentrate have been investigated to date. They have been evaluated as fat replacers in baked goods, antioxidants in meat formulations, phosphate replacers in chicken marinades, and antimicrobials in food systems. Overall, dried plum products have been shown to be effective at reducing lipid oxidation and show promise as antimicrobials.

  15. Simulation of J-aggregate microcavity photoluminescence

    NASA Astrophysics Data System (ADS)

    Michetti, Paolo; La Rocca, Giuseppe C.

    2008-05-01

    We have developed a model in order to account for the photoexcitation dynamics of J-aggregate films and strongly coupled J-aggregate microcavities. The J aggregates are described as a disordered Frenkel exciton system in which relaxation occurs due to the presence of a thermal bath of molecular vibrations. The correspondence between the photophysics in J-aggregate films and that in J-aggregate microcavities is obtained by introducing a model polariton wave function mixing cavity photon modes and J-aggregate super-radiant excitons. With the same description of the material properties, we have calculated both absorption and luminescence spectra for the J-aggregate film and the photoluminescence of strongly coupled organic microcavities. The model is able to account for the fast relaxation dynamics in organic microcavities following nonresonant pumping and explains the temperature dependence of the ratio between the upper polariton and the lower polariton luminescence.

  16. Polymicrobial Multi-functional Approach for Enhancement of Crop Productivity.

    PubMed

    Reddy, Chilekampalli A; Saravanan, Ramu S

    2013-01-01

    There is an increasing global need for enhancing the food production to meet the needs of the fast-growing human population. Traditional approach to increasing agricultural productivity through high inputs of chemical nitrogen and phosphate fertilizers and pesticides is not sustainable because of high costs and concerns about global warming, environmental pollution, and safety concerns. Therefore, the use of naturally occurring soil microbes for increasing productivity of food crops is an attractive eco-friendly, cost-effective, and sustainable alternative to the use of chemical fertilizers and pesticides. There is a vast body of published literature on microbial symbiotic and nonsymbiotic nitrogen fixation, multiple beneficial mechanisms used by plant growth-promoting rhizobacteria (PGPR), the nature and significance of mycorrhiza-plant symbiosis, and the growing technology on production of efficacious microbial inoculants. These areas are briefly reviewed here. The construction of an inoculant with a consortium of microbes with multiple beneficial functions such as N(2) fixation, biocontrol, phosphate solubilization, and other plant growth-promoting properties is a positive new development in this area in that a single inoculant can be used effectively for increasing the productivity of a broad spectrum of crops including legumes, cereals, vegetables, and grasses. Such a polymicrobial inoculant containing several microorganisms for each major function involved in promoting the plant growth and productivity gives it greater stability and wider applications for a range of major crops. Intensifying research in this area leading to further advances in our understanding of biochemical/molecular mechanisms involved in plant-microbe-soil interactions coupled with rapid advances in the genomics-proteomics of beneficial microbes should lead to the design and development of inoculants with greater efficacy for increasing the productivity of a wide range of crops.

  17. Aggregate breakdown of nanoparticulate titania

    NASA Astrophysics Data System (ADS)

    Venugopal, Navin

    Six nanosized titanium dioxide powders synthesized from a sulfate process were investigated. The targeted end-use of this powder was for a de-NOx catalyst honeycomb monolith. Alteration of synthesis parameters had resulted principally in differences in soluble ion level and specific surface area of the powders. The goal of this investigation was to understand the role of synthesis parameters in the aggregation behavior of these powders. Investigation via scanning electron microscopy of the powders revealed three different aggregation iterations at specific length scales. Secondary and higher order aggregate strength was investigated via oscillatory stress rheometry as a means of simulating shear conditions encountered during extrusion. G' and G'' were measured as a function of the applied oscillatory stress. Oscillatory rheometry indicated a strong variation as a function of the sulfate level of the particles in the viscoelastic yield strengths. Powder yield stresses ranged from 3.0 Pa to 24.0 Pa of oscillatory stress. Compaction curves to 750 MPa found strong similarities in extrapolated yield point of stage I and II compaction for each of the powders (at approximately 500 MPa) suggesting that the variation in sulfate was greatest above the primary aggregate level. Scanning electron microscopy of samples at different states of shear in oscillatory rheometry confirmed the variation in the linear elastic region and the viscous flow regime. A technique of this investigation was to approach aggregation via a novel perspective: aggregates are distinguished as being loose open structures that are highly disordered and stochastic in nature. The methodology used was to investigate the shear stresses required to rupture the various aggregation stages encountered and investigate the attempt to realign the now free-flowing constituents comprising the aggregate into a denser configuration. Mercury porosimetry was utilized to measure the pore size of the compact resulting from

  18. An approach to the production of soluble protein from a fungal gene encoding an aggregation-prone xylanase in Escherichia coli.

    PubMed

    Le, Yilin; Peng, Jingjing; Wu, Huawei; Sun, Jianzhong; Shao, Weilan

    2011-04-08

    The development of new procedures and protocols that allow researchers to obtain recombinant proteins is of fundamental importance in the biotechnology field. A strategy was explored to overcome inclusion-body formation observed when expressing an aggregation-prone fungal xylanase in Escherichia coli. pHsh is an expression plasmid that uses a synthetic heat-shock (Hsh) promoter, in which gene expression is regulated by an alternative sigma factor (σ(32)). A derivative of pHsh was constructed by fusing a signal peptide to xynA2 gene to facilitate export of the recombinant protein to the periplasm. The xylanase was produced in a soluble form. Three factors were essential to achieving such soluble expression of the xylanase: 1) the target gene was under the control of the Hsh promoter, 2) the gene product was exported into the periplasm, and 3) gene expression was induced by a temperature upshift. For the first time we report the expression of periplasmic proteins under the control of an Hsh promoter regulated by σ(32). One unique feature of this approach was that over 200 copies of the Hsh promoter in an E. coli cell significantly increased the concentration of σ(32). The growth inhibition of the recombinant cells corresponded to an increase in the levels of soluble periplasmic protein. Therefore, an alternative protocol was designed to induce gene expression from pHsh-ex to obtain high levels of active soluble enzymes.

  19. Thrombolytic therapy reduces red blood cell aggregation in plasma without affecting intrinsic aggregability.

    PubMed

    Ben-Ami, R; Sheinman, G; Yedgar, S; Eldor, A; Roth, A; Berliner, A S; Barshtein, G

    2002-03-15

    Red blood cell (RBC) aggregation may contribute to occlusion of the coronary microcirculation during myocardial infarction. We studied the effect of thrombolytic therapy on RBC aggregation in patients with acute myocardial infarction (AMI). Compared with patients with myocardial infarction who did not receive thrombolytic therapy, those treated with systemic thrombolysis exhibited significantly reduced RBC aggregation, reduced plasma fibrinogen levels and increased plasma D-dimer levels. Using measurement of RBC aggregation in a standardized dextran-500 solution, reduction in RBC aggregation after thrombolysis was shown to be plasma dependent. Thrombolytic therapy had no direct effect on intrinsic RBC aggregability in patients with AMI. We conclude that thrombolytic therapy has rheologic consequences that may contribute to its overall efficacy. Inhibition of RBC aggregation by thrombolytic therapy may result from the degradation of fibrinogen, a key factor in the formation of RBC aggregates, and from the generation of fibrinogen degradation products capable of disaggregating RBCs.

  20. A 3D sphere culture system containing functional polymers for large-scale human pluripotent stem cell production.

    PubMed

    Otsuji, Tomomi G; Bin, Jiang; Yoshimura, Azumi; Tomura, Misayo; Tateyama, Daiki; Minami, Itsunari; Yoshikawa, Yoshihiro; Aiba, Kazuhiro; Heuser, John E; Nishino, Taito; Hasegawa, Kouichi; Nakatsuji, Norio

    2014-05-06

    Utilizing human pluripotent stem cells (hPSCs) in cell-based therapy and drug discovery requires large-scale cell production. However, scaling up conventional adherent cultures presents challenges of maintaining a uniform high quality at low cost. In this regard, suspension cultures are a viable alternative, because they are scalable and do not require adhesion surfaces. 3D culture systems such as bioreactors can be exploited for large-scale production. However, the limitations of current suspension culture methods include spontaneous fusion between cell aggregates and suboptimal passaging methods by dissociation and reaggregation. 3D culture systems that dynamically stir carrier beads or cell aggregates should be refined to reduce shearing forces that damage hPSCs. Here, we report a simple 3D sphere culture system that incorporates mechanical passaging and functional polymers. This setup resolves major problems associated with suspension culture methods and dynamic stirring systems and may be optimal for applications involving large-scale hPSC production.

  1. Labile aggregation stimulating substance, free fatty acids, and platelet aggregation.

    PubMed

    Gerrard, J M; White, J G; Krivit, W

    1976-01-01

    Labile aggregation stimulating substance (LASS), an intermediate produced during platelet biosynthesis of PGE2 and PGF2alpha, acts as a physiologic intercellular messenger to promote platelet aggregation and the release reaction. The activity is formed by intact cells after physiologic stimulation or can be generated from platelet membrane fractions after combination with arachidonate. In the present investigation, small amounts of polyunsaturated fatty acids added to an incubation mixture of platelet microsomes and arachidonate were found to significantly inhibit subsequent platelet aggregation. Saturated and mono-unsaturated fatty acids in the same concentrations were without effect. However, in higher concentrations mono-unsaturated fatty acids were found to be inhibitory and stearic acid was found to enhance subsequent platelet aggregation. The inhibition caused by the polyunsaturated fatty acid, linoleate, was shown to be the result of an effect on the production of LASS through an interaction with the platelet enzyme responsible for conversion of arachidonate to LASS. In contrast, stearic acid was found to enhance platelet aggregation by acting on the platelets and not directly on LASS production. The results suggest that small changes in the fatty acid composition of platelet phospholipids could significantly influence platelet reactivity.

  2. Review: Production and functionality of active peptides from milk.

    PubMed

    Muro Urista, C; Álvarez Fernández, R; Riera Rodriguez, F; Arana Cuenca, A; Téllez Jurado, A

    2011-08-01

    In recent years, research on the production of active peptides obtained from milk and their potential functionality has grown, to a great extent. Bioactive peptides have been defined as specific protein fragments that have a positive impact on body functions or conditions, and they may ultimately have an influence on health. Individual proteins of casein or milk-derived products such as cheese and yogurt have been used as a protein source to study the isolation and activity of peptides with several applications. Currently, the milk whey waste obtained in the production of cheese also represents a protein source from which active peptides could be isolated with potential industrial applications. The active properties of milk peptides and the results found with regard to their physiological effects have led to the classification of peptides as belonging to the group of ingredients of protein nature, appropriate for use in functional foods or pharmaceutical formulations. In this study, the main peptides obtained from milk protein and the past research studies about its production and biological activities will be explained. Second, an analysis will be made on the methods to determinate the biological activities, the separation of bioactive peptides and its structure identification. All of these form the base required to obtain synthetic peptides. Finally, we explain the experimental animal and human trials done in the past years. Nevertheless, more research is required on the design and implementation of equipment for the industrial production and separation of peptides. In addition, different authors suggest that more emphasis should therefore be given to preclinical studies, proving that results are consistent and that effects are demonstrated repeatedly by several research human groups.

  3. Is lactate an undervalued functional component of fermented food products?

    PubMed Central

    Garrote, Graciela L.; Abraham, Analía G.; Rumbo, Martín

    2015-01-01

    Although it has been traditionally regarded as an intermediate of carbon metabolism and major component of fermented dairy products contributing to organoleptic and antimicrobial properties of food, there is evidence gathered in recent years that lactate has bioactive properties that may be responsible of broader properties of functional foods. Lactate can regulate critical functions of several key players of the immune system such as macrophages and dendritic cells, being able to modulate inflammatory activation of epithelial cells as well. Intraluminal levels of lactate derived from fermentative metabolism of lactobacilli have been shown to modulate inflammatory environment in intestinal mucosa. The molecular mechanisms responsible to these functions, including histone deacetylase dependent-modulation of gene expression and signaling through G-protein coupled receptors have started to be described. Since lactate is a major fermentation product of several bacterial families with probiotic properties, we here propose that it may contribute to some of the properties attributed to these microorganisms and in a larger view, to the properties of food products fermented by lactic acid bacteria. PMID:26150815

  4. Affected functional networks associated with sentence production in classic galactosemia.

    PubMed

    Timmers, Inge; van den Hurk, Job; Hofman, Paul Am; Zimmermann, Luc Ji; Uludağ, Kâmil; Jansma, Bernadette M; Rubio-Gozalbo, M Estela

    2015-08-07

    Patients with the inherited metabolic disorder classic galactosemia have language production impairments in several planning stages. Here, we assessed potential deviations in recruitment and connectivity across brain areas responsible for language production that may explain these deficits. We used functional magnetic resonance imaging (fMRI) to study neural activity and connectivity while participants carried out a language production task. This study included 13 adolescent patients and 13 age- and gender-matched healthy controls. Participants passively watched or actively described an animated visual scene using two conditions, varying in syntactic complexity (single words versus a sentence). Results showed that patients recruited additional and more extensive brain regions during sentence production. Both groups showed modulations with syntactic complexity in left inferior frontal gyrus (IFG), a region associated with syntactic planning, and in right insula. In addition, patients showed a modulation with syntax in left superior temporal gyrus (STG), whereas the controls did not. Further, patients showed increased activity in right STG and right supplementary motor area (SMA). The functional connectivity data showed similar patterns, with more extensive connectivity with frontal and motor regions, and restricted and weaker connectivity with superior temporal regions. Patients also showed higher baseline cerebral blood flow (CBF) in right IFG and trends towards higher CBF in bilateral STG, SMA and the insula. Taken together, the data demonstrate that language abnormalities in classic galactosemia are associated with specific changes within the language network. These changes point towards impairments related to both syntactic planning and speech motor planning in these patients.

  5. Erythrocyte aggregation: basic aspects and clinical importance.

    PubMed

    Baskurt, Oguz K; Meiselman, Herbert J

    2013-01-01

    Red blood cell (RBC) aggregate to form two- and three-dimensional structures when suspended in aqueous solutions containing large plasma proteins or polymers; this aggregation is reversible and shear dependent (i.e., dispersed at high shear and reformed at low or stasis). The extent of aggregation is the main determinant of low shear blood viscosity, thus predicting an inverse relationship between aggregation and in vivo blood flow. However, the effects of aggregation on hemodynamic mechanisms (e.g., plasma skimming, Fåhraeus Effect, microvascular hematocrit) may promote rather than impede vascular blood flow. The impact of enhanced RBC aggregation on endothelial function and hemostatic mechanisms adds further complexity, thereby requiring specific attention to the nature, extent and time course of aggregation when considering its overall influence on tissue perfusion. A detailed understanding of aggregation effects is important from a clinical point of view since it may be enhanced during a variety of pathophysiological processes, including infections, circulatory and metabolic disorders, hematological pathologies and several other disease states. Altered RBC aggregation may be an indicator of disease as well as a factor affecting the course of the clinical condition; the prognostic value of RBC aggregation indices has been demonstrated in various diseases. Currently, RBC aggregation is an easily and accurately measurable parameter, and therefore may be expected to have broader clinical usage in the future.

  6. Biocatalysis for the production of industrial products and functional foods from rice and other agricultural produce.

    PubMed

    Akoh, Casimir C; Chang, Shu-Wei; Lee, Guan-Chiun; Shaw, Jei-Fu

    2008-11-26

    Many industrial products and functional foods can be obtained from cheap and renewable raw agricultural materials. For example, starch can be converted to bioethanol as biofuel to reduce the current demand for petroleum or fossil fuel energy. On the other hand, starch can also be converted to useful functional ingredients, such as high fructose and high maltose syrups, wine, glucose, and trehalose. The conversion process involves fermentation by microorganisms and use of biocatalysts such as hydrolases of the amylase superfamily. Amylases catalyze the process of liquefaction and saccharification of starch. It is possible to perform complete hydrolysis of starch by using the fusion product of both linear and debranching thermostable enzymes. This will result in saving energy otherwise needed for cooling before the next enzyme can act on the substrate, if a sequential process is utilized. Recombinant enzyme technology, protein engineering, and enzyme immobilization are powerful tools available to enhance the activity of enzymes, lower the cost of enzyme through large scale production in a heterologous host, increase their thermostability, improve pH stability, enhance their productivity, and hence making it competitive with the chemical processes involved in starch hydrolysis and conversions. This review emphasizes the potential of using biocatalysis for the production of useful industrial products and functional foods from cheap agricultural produce and transgenic plants. Rice was selected as a typical example to illustrate many applications of biocatalysis in converting low-value agricultural produce to high-value commercial food and industrial products. The greatest advantages of using enzymes for food processing and for industrial production of biobased products are their environmental friendliness and consumer acceptance as being a natural process.

  7. Characterization of a multiresistant mosaic plasmid from a fish farm Sediment Exiguobacterium sp. isolate reveals aggregation of functional clinic-associated antibiotic resistance genes.

    PubMed

    Yang, Jing; Wang, Chao; Wu, Jinyu; Liu, Li; Zhang, Gang; Feng, Jie

    2014-02-01

    The genus Exiguobacterium can adapt readily to, and survive in, diverse environments. Our study demonstrated that Exiguobacterium sp. strain S3-2, isolated from marine sediment, is resistant to five antibiotics. The plasmid pMC1 in this strain carries seven putative resistance genes. We functionally characterized these resistance genes in Escherichia coli, and genes encoding dihydrofolate reductase and macrolide phosphotransferase were considered novel resistance genes based on their low similarities to known resistance genes. The plasmid G+C content distribution was highly heterogeneous. Only the G+C content of one block, which shared significant similarity with a plasmid from Exiguobacterium arabatum, fit well with the mean G+C content of the host. The remainder of the plasmid was composed of mobile elements with a markedly lower G+C ratio than the host. Interestingly, five mobile elements located on pMC1 showed significant similarities to sequences found in pathogens. Our data provided an example of the link between resistance genes in strains from the environment and the clinic and revealed the aggregation of antibiotic resistance genes in bacteria isolated from fish farms.

  8. "Oxidative etching-aggregation" of silver nanoparticles by melamine and electron acceptors: an innovative route toward ultrasensitive and versatile functional colorimetric sensors.

    PubMed

    Wang, Guang-Li; Zhu, Xiao-Ying; Jiao, Huan-Jun; Dong, Yu-Ming; Wu, Xiu-Ming; Li, Zai-Jun

    2012-10-17

    An innovative and versatile functional colorimetric sensor for melamine (MA) and H(2)O(2) was developed with simplicity, excellent selectivity and ultrasensitivity. The detection mechanism was based on the "oxidative etching-aggregation" of silver nanoparticles (AgNPs) by the cooperation effect of MA and electron acceptors such as H(2)O(2), ozone or Fe(NO(3))(3). The detection limits of this method for MA could reach as low as 0.08 nM, 0.16 nM and 3 nM when H(2)O(2), ozone or Fe(NO(3))(3) was used as an electron acceptor, respectively. When using H(2)O(2) as a typical electron acceptor, the method enabled the detection of H(2)O(2) with a detection limit of 0.2 nM. This proposed method offered a new way to design MA and H(2)O(2) sensors and might be easily extended to detect other nucleophilic reagents and electron acceptors based on colorimetric sensors.

  9. Ash Aggregates in Proximal Settings

    NASA Astrophysics Data System (ADS)

    Porritt, L. A.; Russell, K.

    2012-12-01

    early pyroclastic phase of the formation of Kima'Kho, a tuya in northern B.C., Canada produced a subaqueous pyroclastic cone which became emergent during the latter stages of formation. Armoured lapilli are pervasive within the emergent upper third of the sequence. No other types of ash aggregates have been observed. Petrographic and textural analysis of the armoured lapilli shows them to comprise a central 2-30 mm-sized, juvenile, vesiculated pyroclast, concentrically coated by mm-scale layers of 10-250 μm sized ash particles. At Kima'Kho, the armoured lapilli are shown to be a direct indicator of fallout from a sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured lapilli (no accretionary lapilli) at Kima'Kho and diverse ash aggregates but no armoured lapilli at A418. Here we investigate vent-proximal ash aggregation and the specific conditions which lead to the formation of coated ash pellets and armoured lapilli.

  10. Gut bacteria mediate aggregation in the German cockroach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aggregation of the German cockroach, Blattella germanica, is regulated by fecal aggregation agents (pheromones), including volatile carboxylic acids (VCAs). We hypothesized that the gut microbial community contributes to production of these semiochemicals. Chemical analysis of the fecal extract of B...

  11. Familial aggregation analysis of gene expressions

    PubMed Central

    Rao, Shao-Qi; Xu, Liang-De; Zhang, Guang-Mei; Li, Xia; Li, Lin; Shen, Gong-Qing; Jiang, Yang; Yang, Yue-Ying; Gong, Bin-Sheng; Jiang, Wei; Zhang, Fan; Xiao, Yun; Wang, Qing K

    2007-01-01

    Traditional studies of familial aggregation are aimed at defining the genetic (and non-genetic) causes of a disease from physiological or clinical traits. However, there has been little attempt to use genome-wide gene expressions, the direct phenotypic measures of genes, as the traits to investigate several extended issues regarding the distributions of familially aggregated genes on chromosomes or in functions. In this study we conducted a genome-wide familial aggregation analysis by using the in vitro cell gene expressions of 3300 human autosome genes (Problem 1 data provided to Genetic Analysis Workshop 15) in order to answer three basic genetics questions. First, we investigated how gene expressions aggregate among different types (degrees) of relative pairs. Second, we conducted a bioinformatics analysis of highly familially aggregated genes to see how they are distributed on chromosomes. Third, we performed a gene ontology enrichment test of familially aggregated genes to find evidence to support their functional consensus. The results indicated that 1) gene expressions did aggregate in families, especially between sibs. Of 3300 human genes analyzed, there were a total of 1105 genes with one or more significant (empirical p < 0.05) familial correlation; 2) there were several genomic hot spots where highly familially aggregated genes (e.g., the chromosome 6 HLA genes cluster) were clustered; 3) as we expected, gene ontology enrichment tests revealed that the 1105 genes were aggregating not only in families but also in functional categories. PMID:18466548

  12. Thermodynamics of Protein Aggregation

    NASA Astrophysics Data System (ADS)

    Osborne, Kenneth L.; Barz, Bogdan; Bachmann, Michael; Strodel, Birgit

    Amyloid protein aggregation characterizes many neurodegenerative disorders, including Alzheimer's, Parkinson's, and Creutz- feldt-Jakob disease. Evidence suggests that amyloid aggregates may share similar aggregation pathways, implying simulation of full-length amyloid proteins is not necessary for understanding amyloid formation. In this study we simulate GNNQQNY, the N-terminal prion-determining domain of the yeast protein Sup35 to investigate the thermodynamics of structural transitions during aggregation. We use a coarse-grained model with replica-exchange molecular dynamics to investigate the association of 3-, 6-, and 12-chain GNNQQNY systems and we determine the aggregation pathway by studying aggregation states of GN- NQQNY. We find that the aggregation of the hydrophilic GNNQQNY sequence is mainly driven by H-bond formation, leading to the formation of /3-sheets from the very beginning of the assembly process. Condensation (aggregation) and ordering take place simultaneously, which is underpinned by the occurrence of a single heat capacity peak only.

  13. Investigating the mechanisms leading to protein aggregation

    NASA Astrophysics Data System (ADS)

    McNamara, Ruth; McManus, Jennifer J.

    2014-03-01

    The formation of protein aggregates is a feature of several diseases and is a problem during the manufacture of biopharmaceutical and protein based food products. During processing, stability may become compromised leading to the condensation of proteins to form non-native aggregates. The aim of this work is to induce aggregation on model proteins by the imposition of a particular stress to evaluate the extent of aggregation and to assess the degree of structural change to the protein. Aggregation of two proteins, lysozyme and bovine serum albumin has been induced by several mechanisms. Using various techniques (electrophoresis, HPLC, spectroscopic analysis, and microscopic techniques) both the level of aggregation extent of protein unfolding has been investigated for a range of solution conditions. Our results show that the amount of aggregation depends strongly on the mechanism by which non-native aggregation proceeds, and within each mechanism, solution conditions are an important factor. With the exception of aggregation by self-association (which is concentration dependent), the appearance of aggregation is driven by structural changes induced by the applied stress (heat, chemical denaturant, oxidation or contact with a surface). Author would like to acknowledge support from Science Foundation Ireland (SFI), National University of Maynooth John and Pat Hume Scholarship.

  14. A 1,3-indandione-functionalized tetraphenylethene: aggregation-induced emission, solvatochromism, mechanochromism, and potential application as a multiresponsive fluorescent probe.

    PubMed

    Tong, Jiaqi; Wang, Yijia; Mei, Ju; Wang, Jian; Qin, Anjun; Sun, Jing Zhi; Tang, Ben Zhong

    2014-04-14

    A tetraphenylethene (TPE) derivative substituted with the electron-acceptor 1,3-indandione (IND) group was designed and prepared. The targeted IND-TPE reserves the intrinsic aggregation-induced emission (AIE) property of the TPE moiety. Meanwhile, owing to the decorated IND moiety, IND-TPE demonstrates intramolecular charge-transfer process and pronounced solvatochromic behavior. When the solvent is changed from apolar toluene to highly polar acetonitrile, the emission peak redshifts from 543 to 597 nm. IND-TPE solid samples show an evident mechanochromic process. Grinding of the as-prepared powder sample induces a redshift of emission from green (peak at 515 nm) to orange (peak at 570 nm). The mechanochromic process is reversible in multiple grinding-thermal annealing and grinding-solvent-fuming cycles, and the emission of the solid sample switches between orange (ground) and yellow (thermal/solvent-fuming-treated) colors. The mechanochromism is ascribed to the phase transition between amorphous and crystalline states. IND-TPE undergoes a hydrolysis reaction in basic aqueous solution, thus the red-orange emission can be quenched by OH(-) or other species that can induce the generation of sufficient OH(-). Accordingly, IND-TPE has been used to discriminatively detect arginine and lysine from other amino acids, due to their basic nature. The experimental data are satisfactory. Moreover, the hydrolyzation product of IND-TPE is weakly emissive in the resultant mixture but becomes highly blue-emissive after the illumination for a period by UV light. Thus IND-TPE can be used as a dual-responsive fluorescent probe, which may extend the application of TPE-based molecular probes in chemical and biological categories.

  15. Chiral dynamics of the polarizing fracture functions for baryon production

    NASA Astrophysics Data System (ADS)

    Sivers, Dennis

    2009-04-01

    The concept of spin-directed momentum provides a useful and restrictive framework for describing dynamical mechanisms that can lead to single-spin observables. The value of this framework can be demonstrated by consideration of the polarizing fracture functions, ΔNMB↑/pq(x,z,kTN;Q2), that characterize the production of polarized baryons in the target fragmentation region of semi-inclusive deep-inelastic scattering from an unpolarized target. When Bjorken x is chosen large enough to indicate a hard scattering from a valence quark, the fracture function formalism dynamically selects a quark-diquark basis for baryon structure. Attention to constituent orbital angular momentum in the formation process and its role in contributing to the transverse momentum of the produced baryon illustrates important aspects of the generation of polarization observables.

  16. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2007-01-01

    The present invention provides a method for production of functional proteins including hormones by renal cells in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-a-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  17. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2004-01-01

    The present invention provides a method for production of functional proteins including hormones by renal cells in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-a-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  18. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2011-01-01

    A method for the production of functional proteins including hormones by renal cells in a three dimensional culturing process responsive to shear stress uses a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-.alpha.-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D.sub.3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating an in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  19. Natural aggregates of the conterminous United States

    USGS Publications Warehouse

    Langer, William H.

    1988-01-01

    adversely when used as concrete aggregate. In areas where suitable natural aggregate is not available or accessible, it may become necessary to improve the quality of existing aggregate, to import aggregate from outside the area, or to substitute artificial aggregate for natural aggregate. In most cases, all of these alternatives add substantially to the cost of the final product. Even though an area may be blessed with an abundance of aggregate suitable for the intended purpose, existing land uses, zoning, or regulations may preclude commercial exploitation of the aggregate. This report also discusses the aggregate industry in general terms, including exploration, mining, and processing, as well as aggregate production rates. Proper long-range planning based on an understanding of the aggregate industry can help assure adequate supplies of aggregate.

  20. Leaching behaviour of synthetic aggregates.

    PubMed

    van der Sloot, H A; Hoede, D; Cresswell, D J; Barton, J R

    2001-01-01

    In the framework of EU project "Utilising innovative kiln technology to recycle waste into synthetic aggregate" (BRST-CT98-5234), the leaching behaviour of synthetic aggregates has been studied to assess its environmental compatibility in the various stages of its use. Since the conditions are very different for the different uses, the assessment calls for a variety of different leaching conditions. The pH dependence test is used to cover important differences in pH environment to which the materials are exposed to as well as for an assessment of the buffering capacity of the material. Synthetic aggregate features a low buffer capacity, which makes it sensitive to externally imposed pH conditions. Utilisation and storage exposed to acidic conditions needs to be avoided. The results of the pH dependence test and column leaching test are mutually consistent. The CEN TC 154 method appears to provide systematically low values due to the arbitrary selection of test conditions. Synthetic aggregate studied to date will not adversely affect the concrete in its service life. The main issue for aggregate use is the recycling and the "end of life" condition, when the material becomes construction debris. Not metals, but oxyanions, such as Cr VI and Mo are most relevant under these conditions. A concise test has been applied to assess crucial aspects of leaching for different production mixes.

  1. Hydrodynamic behavior of fractal aggregates

    NASA Astrophysics Data System (ADS)

    Wiltzius, Pierre

    1987-02-01

    Measurements of the radius of gyration RG and the hydrodynamic radius RH of colloidal silica aggregates are reported. These aggregates have fractal geometry and RH is proportional to RG for 500 Å<=RH<=7000 Å, with a ratio RH/RG=0.72+/-0.02. The results are compared with predictions for macromolecules of various shapes. The proportionality of the two radii can be understood with use of the pair correlation function of fractal objects and hydrodynamic interactions on the Oseen level. The value of the ratio remains to be explained.

  2. Scalable production of microbially mediated zinc sulfide nanoparticles and application to functional thin films.

    PubMed

    Moon, Ji-Won; Ivanov, Ilia N; Joshi, Pooran C; Armstrong, Beth L; Wang, Wei; Jung, Hyunsung; Rondinone, Adam J; Jellison, Gerald E; Meyer, Harry M; Jang, Gyoung Gug; Meisner, Roberta A; Duty, Chad E; Phelps, Tommy J

    2014-10-01

    A series of semiconducting zinc sulfide (ZnS) nanoparticles were scalably, reproducibly, controllably and economically synthesized with anaerobic metal-reducing Thermoanaerobacter species. These bacteria reduced partially oxidized sulfur sources to sulfides that extracellularly and thermodynamically incorporated with zinc ions to produce sparingly soluble ZnS nanoparticles with ∼5nm crystallites at yields of ∼5gl(-1)month(-1). A predominant sphalerite formation was facilitated by rapid precipitation kinetics, a low cation/anion ratio and a higher zinc concentration compared to background to produce a naturally occurring hexagonal form at the low temperature, and/or water adsorption in aqueous conditions. The sphalerite ZnS nanoparticles exhibited narrow size distribution, high emission intensity and few native defects. Scale-up and emission tunability using copper doping were confirmed spectroscopically. Surface characterization was determined using Fourier transform infrared and X-ray photoelectron spectroscopies, which confirmed amino acid as proteins and bacterial fermentation end products not only maintaining a nano-dimensional average crystallite size, but also increasing aggregation. The application of ZnS nanoparticle ink to a functional thin film was successfully tested for potential future applications.

  3. Design of smart functional apparel products for moxa moxibustion

    NASA Astrophysics Data System (ADS)

    Li, Li; Au, Wai-man; Ding, Feng; Wong, Kwok-shing

    2013-08-01

    Moxa Moxibustion is a common traditional Chinese therapy in which burning Moxa is applied to affected body areas. This method has been employed for thousands of years to achieve certain medical objectives, such as pain relief or antibacterial and anti-inflammatory effects. Its therapeutic effectiveness has been demonstrated successfully both in research and clinical studies. However, this traditional approach may cause undesirable side effects, for example: 1) burning of Moxa produces by-products such as smoke and ash; 2) patients are at risk of being burnt; 3) the active ingredients of the Moxa leaf oil are volatile, odorous, unstable in air and easy to dissipate, and difficult to store and transport; 4) it is inconvenient to operate. These side effects limit its further high-potential and high-value applications. This study is aimed at developing a multi-functional smart textile system that will adopt smart fabrics containing encapsulated Moxa oil integrated with thermally conductive materials to replace the conventional Moxa products. This will efficiently deliver the active ingredients of Moxa to a human body at optimum conditions, i.e., in a precise and controllable way, with maximum convenience and a high level of comfort. Doing so would solve the existing problems mentioned above. Both garment design skill and textile technology will be applied to Moxa Moxibustion textile to enhance the aesthetics and functionality. The smart garment performance will be assessed subjectively in a clinical trial and objectively by a number of instrumental methods.

  4. On mean type aggregation.

    PubMed

    Yager, R R

    1996-01-01

    We introduce and define the concept of mean aggregation of a collection of n numbers. We point out that the lack of associativity of this operation compounds the problem of the extending mean of n numbers to n+1 numbers. The closely related concepts of self identity and the centering property are introduced as one imperative for extending mean aggregation operators. The problem of weighted mean aggregation is studied. A new concept of prioritized mean aggregation is then introduced. We next show that the technique of selecting an element based upon the performance of a random experiment can be considered as a mean aggregation operation.

  5. Variable aggregation rates in colloidal gold: Kernel homogeneity dependence on aggregant concentration

    NASA Astrophysics Data System (ADS)

    Olivier, B. J.; Sorensen, C. M.

    1990-02-01

    Dynamic light scattering is used to study the dependence of the aggregation kernel homogeneity λ on the aggregant concentration [HCl] for aqueous gold sols. We find the cluster growth kinetics are well described by a powerlaw, Rapp~tz/D, where Rapp is the measured apparent radius, D the cluster fractal dimension, and z=1/(1-λ) for all aggregant concentrations. The values for the dynamic exponent z, and hence the homogeneity λ, are functions of HCl concentration. We find the larger HCl concentrations yield a fast-aggregation regime characterized by λ~=-0.6. Smaller HCl concentrations yield a continuum of aggregation regimes characterized by homogeneities evolving from λ~=-0.6 towards 1.0. Our results do not support the view that aggregation in gold colloids is based on two limiting regimes, diffusion-limited and reaction-limited aggregation.

  6. Environmentalism and natural aggregate mining

    USGS Publications Warehouse

    Drew, L.J.; Langer, W.H.; Sachs, J.S.

    2002-01-01

    living space has encroached on the sites of production; in other words, the act of production has engendered condemnation. Many other environmental problems that are associated with dust and noise and blasting from quarry and pit operations have been reduced through the efficient use of technology. Recycling concrete in buildings, bridges, and roads and asphaltic pavements will ultimately reduce the demand for virgin natural aggregate. The impact created by the large holes in the ground required for the mining of natural aggregate can be greatly reduced by planning their reclamation before mining begins. ?? 2002 International Association for Mathematical Geology.

  7. Injury Profile SIMulator, a Qualitative Aggregative Modelling Framework to Predict Injury Profile as a Function of Cropping Practices, and Abiotic and Biotic Environment. II. Proof of Concept: Design of IPSIM-Wheat-Eyespot

    PubMed Central

    Robin, Marie-Hélène; Colbach, Nathalie; Lucas, Philippe; Montfort, Françoise; Cholez, Célia; Debaeke, Philippe; Aubertot, Jean-Noël

    2013-01-01

    IPSIM (Injury Profile SIMulator) is a generic modelling framework presented in a companion paper. It aims at predicting a crop injury profile as a function of cropping practices and abiotic and biotic environment. IPSIM's modelling approach consists of designing a model with an aggregative hierarchical tree of attributes. In order to provide a proof of concept, a model, named IPSIM-Wheat-Eyespot, has been developed with the software DEXi according to the conceptual framework of IPSIM to represent final incidence of eyespot on wheat. This paper briefly presents the pathosystem, the method used to develop IPSIM-Wheat-Eyespot using IPSIM's modelling framework, simulation examples, an evaluation of the predictive quality of the model with a large dataset (526 observed site-years) and a discussion on the benefits and limitations of the approach. IPSIM-Wheat-Eyespot proved to successfully represent the annual variability of the disease, as well as the effects of cropping practices (Efficiency = 0.51, Root Mean Square Error of Prediction = 24%; bias = 5.0%). IPSIM-Wheat-Eyespot does not aim to precisely predict the incidence of eyespot on wheat. It rather aims to rank cropping systems with regard to the risk of eyespot on wheat in a given production situation through ex ante evaluations. IPSIM-Wheat-Eyespot can also help perform diagnoses of commercial fields. Its structure is simple and permits to combine available knowledge in the scientific literature (data, models) and expertise. IPSIM-Wheat-Eyespot is now available to help design cropping systems with a low risk of eyespot on wheat in a wide range of production situations, and can help perform diagnoses of commercial fields. In addition, it provides a proof of concept with regard to the modelling approach of IPSIM. IPSIM-Wheat-Eyespot will be a sub-model of IPSIM-Wheat, a model that will predict injury profile on wheat as a function of cropping practices and the production situation. PMID:24146783

  8. Directional sensing and streaming in Dictyostelium aggregation

    NASA Astrophysics Data System (ADS)

    Almeida, Sofia; Dilão, Rui

    2016-05-01

    We merge the Kessler-Levine simple discrete model for Dictyostelium cyclic adenosine monophosphate (cAMP) production and diffusion with the Dilão-Hauser directional sensing aggregation mechanism. The resulting compound model describes all the known transient patterns that emerge during Dictyostelium aggregation, which include the spontaneous formation of cAMP self-sustained target and spiral waves and streaming. We show that the streaming patterns depend on the speed of the amoebae, on the relaxation time for the production of cAMP, on the cAMP degradation rate, and on directional sensing. Moreover, we show that different signaling centers emerge during Dictyostelium aggregation.

  9. Mold-Ripened Soft Cheeses Fortified with Date Palm Fruit Product as Functional Dairy Products.

    PubMed

    Al-Otaibi, Mutlag M; Haddadin, Jamal S; Haddadin, Malik S Y

    2016-01-01

    Date fruit based products are gaining popularity among the consumers in almost all date growing countries due to its added nutritional value. Therefore, novel products were developed by combining two types of foods i.e., soft ripened cheeses and date fruit syrups or date powder. This study is the first to report the surface mold-ripened cheese production with date syrup and date powder. Model cheeses were prepared from pasteurized milk inoculated with Streptococcus thermophilus, Penicillium camemberti and Geotrichum candidum. Date syrup-1, date syrup-2, date powder or the date mixture were added at the stage of curdling. Based on the kinetic growth of the microbial groups in all the treatments, there was no change in the growth of these in various date palm product. On the contrary It may be said that addition of the date fruit product supports their growth. After 35 days, the amounts of total poly phenols were 128.3 ± 1.01, 81.8 ± 1.11, 33.5 ± 2.19, 156.23 ± 1.27 mg GAE/100 g in the cheeses support with date syrup-1, date syrup-2, date powder or the date mixture, respectively. Antioxidant activity of date fruits ranged from 80.13 IC50 (date syrup-2) to 82.23 IC50 (date syrup-1). Based on the chemical characteristics and sensory analysis, the study results showed the potential for innovative application of date products for developing new functional dairy products as an ideal medium for the delivery of biological active compounds with beneficial health effects over.

  10. A competitive aggregation model for flash nanoprecipitation.

    PubMed

    Cheng, Janine Chungyin; Vigil, R D; Fox, R O

    2010-11-15

    Flash NanoPrecipitation (FNP) is a novel approach for producing functional nanoparticles stabilized by amphiphilic block copolymers. FNP involves the rapid mixing of a hydrophobic active (organic) and an amphiphilic di-block copolymer with a non-solvent (water) and subsequent co-precipitation of nanoparticles composed of both the organic and copolymer. During this process, the particle size distribution (PSD) is frozen and stabilized by the hydrophilic portion of the amphiphilic di-block copolymer residing on the particle surface. That is, the particle growth is kinetically arrested and thus a narrow PSD can be attained. To model the co-precipitation process, a bivariate population balance equation (PBE) has been formulated to account for the competitive aggregation of the organic and copolymer versus pure organic-organic or copolymer-copolymer aggregation. Aggregation rate kernels have been derived to account for the major aggregation events: free coupling, unimer insertion, and aggregate fusion. The resulting PBE is solved both by direct integration and by using the conditional quadrature method of moments (CQMOM). By solving the competitive aggregation model under well-mixed conditions, it is demonstrated that the PSD is controlled primarily by the copolymer-copolymer aggregation process and that the energy barrier to aggregate fusion plays a key role in determining the PSD. It is also shown that the characteristic aggregation times are smaller than the turbulent mixing time so that the FNP process is always mixing limited.

  11. Thiophene functionalized silicon-containing aggregation-induced emission enhancement materials: applications as fluorescent probes for the detection of nitroaromatic explosives in aqueous-based solutions.

    PubMed

    Wang, Xuefeng; Bian, Jiangyan; Xu, Lichao; Wang, Hua; Feng, Shengyu

    2015-12-28

    Two novel aggregation-induced emission enhancement (AIEE) molecules, namely, 3,4-diphenyl-2,5-di(2-thienyl)phenyltrimethylsilane (DPTB-TMS) and bis[3,4-diphenyl- 2,5-di(2-thienyl)phenyl]methylphenylsilane (DPTB-TMS) were designed and synthesized. The optical properties of the two silanes were completely opposite to the traditional luminescent materials. Unlike the aggregation caused quenching, they all emit faint fluorescence in the dispersed state, while emission intensity increased sharply in aggregate states. Fluorescence spectra showed that the two compounds exhibited AIEE properties and that is due to the weak π-π stacking caused by the restriction of intramolecular rotations of dye segments, particularly the -SiMe3 and thienyl groups in the aggregate state. As fluorescent (FL) probes, the fluorescence quenching behavior was further investigated. Thanks to the richer-electron thiophene groups, both compounds showed good performance in detecting nitroaromatics, especially picric acid (PA). The two AIEE FL probes exhibited better quenching efficiency in aqueous-based than in organic-based solutions. For DPTB-MPS, the addition of 80 μM nitrobenzene, 60 μM m-nitrobenzene and 40 μM PA resulted in about 50% quenching in aqueous solutions. The quenching mechanism would be electron transfer from silanes to nitroaromatics. This work provides a basis for designing organic-silanes with "abnormal" but useful optical properties and FL probes with AIEE properties for the detection of nitroaromatics.

  12. Impact of bioenergy production on carbon storage and soil functions

    NASA Astrophysics Data System (ADS)

    Prays, Nadia; Franko, Uwe

    2016-04-01

    An important renewable energy source is methane produced in biogas plants (BGPs) that convert plant material and animal excrements to biogas and a residue (BGR). If the plant material stems from crops produced specifically for that purpose, a BGP have a 'footprint' that is defined by the area of arable land needed for the production of these energy crops and the area for distributing the BGRs. The BGR can be used to fertilize these lands (reducing the need for carbon and nitrogen fertilizers), and the crop land can be managed to serve as a carbon sink, capturing atmospheric CO2. We focus on the ecological impact of different BGPs in Central Germany, with a specific interest in the long-term effect of BGR-fertilization on carbon storage within the footprint of a BGP. We therefore studied nutrient fluxes using the CANDY (CArbon and Nitrogen Dynamics) model, which processes site-specific information on soils, crops, weather, and land management to compute stocks and fluxes of carbon and nitrogen for agricultural fields. We used CANDY to calculated matter fluxes within the footprints of BGPs of different sizes, and studied the effect of the substrate mix for the BGP on the carbon dynamics of the soil. This included the land requirement of the BGR recycling when used as a fertilizer: the footprint of a BGP required for the production of the energy crop generally differs from its footprint required to take up its BGR. We demonstrate how these findings can be used to find optimal cropping choices and land management for sustainable soil use, maintaining soil fertility and other soil functions. Furthermore, site specific potentials and limitations for agricultural biogas production can be identified and applied in land-use planning.

  13. Glycation of Lysozyme by Glycolaldehyde Provides New Mechanistic Insights in Diabetes-Related Protein Aggregation.

    PubMed

    Mariño, Laura; Maya-Aguirre, Carlos Andrés; Pauwels, Kris; Vilanova, Bartolomé; Ortega-Castro, Joaquin; Frau, Juan; Donoso, Josefa; Adrover, Miquel

    2017-03-14

    Glycation occurs in vivo as a result of the nonenzymatic reaction of carbohydrates (and/or their autoxidation products) with proteins, DNA, or lipids. Protein glycation causes loss-of-function and, consequently, the development of diabetic-related diseases. Glycation also boosts protein aggregation, which can be directly related with the higher prevalence of aggregating diseases in diabetic people. However, the molecular mechanism connecting glycation with aggregation still remains unclear. Previously we described mechanistically how glycation of hen egg-white lysozyme (HEWL) with ribose induced its aggregation. Here we address the question of whether the ribose-induced aggregation is a general process or it depends on the chemical nature of the glycating agent. Glycation of HEWL with glycolaldehyde occurs through two different scenarios depending on the HEWL concentration regime (both within the micromolar range). At low HEWL concentration, non-cross-linking fluorescent advanced glycation end-products (AGEs) are formed on Lys side chains, which do not change the protein structure but inhibit its enzymatic activity. These AGEs have little impact on HEWL surface hydrophobicity and, therefore, a negligible effect on its aggregation propensity. Upon increasing HEWL concentration, the glycation mechanism shifts toward the formation of intermolecular cross-links, which triggers a polymerization cascade involving the formation of insoluble spherical-like aggregates. These results notably differ with the aggregation-modulation mechanism of ribosylated HEWL directed by hydrophobic interactions. Additionally, their comparison constitutes the first experimental evidence showing that the mechanism underlying the aggregation of a glycated protein depends on the chemical nature of the glycating agent.

  14. The yin and yang of amyloid aggregation

    PubMed Central

    Falsone, S Fabio

    2015-01-01

    Intra- and extra-cellular amyloid protein fibers are traditionally coupled to a series of devastating and incurable neurodegenerative disorders. Since the discovery of physiologically useful amyloids, our attention has been shifting from pure pathology to function, as amyloid aggregation seems to constitute a basis for the functional and dynamic assembly of biological structures. The following article summarizes how the cell profits from such an unconventional high-risk aggregation at the rim of physiologic utility and pathologic catastrophe. PMID:28031869

  15. Oil-Price Shocks: Beyond Standard Aggregate Demand/Aggregate Supply Analysis.

    ERIC Educational Resources Information Center

    Elwood, S. Kirk

    2001-01-01

    Explores the problems of portraying oil-price shocks using the aggregate demand/aggregate supply model. Presents a simple modification of the model that differentiates between production and absorption of goods, which enables it to better reflect the effects of oil-price shocks on open economies. (RLH)

  16. Ion exchange chromatography of proteins and clearance of aggregates.

    PubMed

    Yigzaw, Y; Hinckley, P; Hewig, A; Vedantham, G

    2009-06-01

    Clearance of product related aggregates in therapeutic proteins is a major focus of purification process development. A typical purification process will have one or two chromatographic steps that remove these product related aggregates to an acceptable level. Both cation exchange and anion exchange chromatography can provide robust clearance of aggregates. The primary factors that are critical for aggregate clearance are: resin chemistry, binding and elution condition, peak collection and column load factor. This review covers how these factors can be optimized to increase the effectiveness of ion exchange chromatography in removing aggregates.

  17. Rapid Naked‐Eye Discrimination of Cytochrome P450 Genetic Polymorphism through Non‐Crosslinking Aggregation of DNA‐Functionalized Gold Nanoparticles

    PubMed Central

    Akiyama, Yoshitsugu; Wang, Guoqing; Shiraishi, Shota; Kanayama, Naoki; Maeda, Mizuo

    2016-01-01

    Abstract The front cover artwork is provided by the group of Tohru Takarada at RIKEN (Japan). The image shows a colorimetric single‐nucleotide polymorphism (SNP) genotyping method that uses spontaneous aggregation of DNA‐modified gold nanoparticles (DNA–AuNPs) for the simple and rapid SNP genotyping of the human cytochrome P450 2C19 monooxygenase gene. For more details, read the full text of the Full Paper at p. 508. PMID:28032015

  18. Structural and functional properties of hemp seed protein products.

    PubMed

    Malomo, Sunday A; He, Rong; Aluko, Rotimi E

    2014-08-01

    The effects of pH and protein concentration on some structural and functional properties of hemp seed protein isolate (HPI, 84.15% protein content) and defatted hemp seed protein meal (HPM, 44.32% protein content) were determined. The HPI had minimum protein solubility (PS) at pH 4.0, which increased as pH was decreased or increased. In contrast, the HPM had minimum PS at pH 3.0, which increased at higher pH values. Gel electrophoresis showed that some of the high molecular weight proteins (>45 kDa) present in HPM were not well extracted by the alkali and were absent or present in low ratio in the HPI polypeptide profile. The amino acid composition showed that the isolation process increased the Arg/Lys ratio of HPI (5.52%) when compared to HPM (3.35%). Intrinsic fluorescence and circular dichroism data indicate that the HPI proteins had a well-defined structure at pH 3.0, which was lost as pH value increased. The differences in structural conformation of HPI at different pH values were reflected as better foaming capacity at pH 3.0 when compared to pH 5.0, 7.0, and 9.0. At 10 and 25 mg/mL protein concentrations, emulsions formed by the HPM had smaller oil droplet sizes (higher quality), when compared to the HPI-formed emulsions. In contrast at 50 mg/mL protein concentration, the HPI-formed emulsions had smaller oil droplet sizes (except at pH 3.0). We conclude that the functional properties of hemp seed protein products are dependent on structural conformations as well as protein concentration and pH.

  19. Oxygen limitation within a bacterial aggregate.

    PubMed

    Wessel, Aimee K; Arshad, Talha A; Fitzpatrick, Mignon; Connell, Jodi L; Bonnecaze, Roger T; Shear, Jason B; Whiteley, Marvin

    2014-04-15

    ABSTRACT Cells within biofilms exhibit physiological heterogeneity, in part because of chemical gradients existing within these spatially structured communities. Previous work has examined how chemical gradients develop in large biofilms containing >10(8) cells. However, many bacterial communities in nature are composed of small, densely packed aggregates of cells (≤ 10(5) bacteria). Using a gelatin-based three-dimensional (3D) printing strategy, we confined the bacterium Pseudomonas aeruginosa within picoliter-sized 3D "microtraps" that are permeable to nutrients, waste products, and other bioactive small molecules. We show that as a single bacterium grows into a maximally dense (10(12) cells ml(-1)) clonal population, a localized depletion of oxygen develops when it reaches a critical aggregate size of ~55 pl. Collectively, these data demonstrate that chemical and phenotypic heterogeneity exists on the micrometer scale within small aggregate populations. IMPORTANCE Before developing into large, complex communities, microbes initially cluster into aggregates, and it is unclear if chemical heterogeneity exists in these ubiquitous micrometer-scale aggregates. We chose to examine oxygen availability within an aggregate since oxygen concentration impacts a number of important bacterial processes, including metabolism, social behaviors, virulence, and antibiotic resistance. By determining that oxygen availability can vary within aggregates containing ≤ 10(5) bacteria, we establish that physiological heterogeneity exists within P. aeruginosa aggregates, suggesting that such heterogeneity frequently exists in many naturally occurring small populations.

  20. A novel fusion protein domain III-capsid from dengue-2, in a highly aggregated form, induces a functional immune response and protection in mice

    SciTech Connect

    Valdes, Iris; Bernardo, Lidice; Pavon, Alekis; Guzman, Maria G.

    2009-11-25

    Based on the immunogenicity of domain III from the Envelope protein of dengue virus as well as the proven protective capacity of the capsid antigen, we have designed a novel domain III-capsid chimeric protein with the goal of obtaining a molecule potentially able to induce both humoral and cell-mediated immunity (CMI). After expression of the recombinant gene in Escherichia coli, the domain III moiety retained its antigenicity as evaluated with anti-dengue sera. In order to explore alternatives for modulating the immunogenicity of the protein, it was mixed with oligodeoxynucleotides in order to obtain particulated aggregates and then immunologically evaluated in mice in comparison with non-aggregated controls. Although the humoral immune response induced by both forms of the protein was equivalent, the aggregated variant resulted in a much stronger CMI as measured by in vitro IFN-gamma secretion and protection experiments, mediated by CD4{sup +} and CD8{sup +} cells. The present work provides additional evidence in support for a crucial role of CMI in protection against dengue virus and describes a novel vaccine candidate against the disease based on a recombinant protein that can stimulate both arms of the acquired immune system.

  1. A novel fusion protein domain III-capsid from dengue-2, in a highly aggregated form, induces a functional immune response and protection in mice.

    PubMed

    Valdés, Iris; Bernardo, Lidice; Gil, Lázaro; Pavón, Alekis; Lazo, Laura; López, Carlos; Romero, Yaremis; Menendez, Ivón; Falcón, Viviana; Betancourt, Lázaro; Martín, Jorge; Chinea, Glay; Silva, Ricardo; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

    2009-11-25

    Based on the immunogenicity of domain III from the Envelope protein of dengue virus as well as the proven protective capacity of the capsid antigen, we have designed a novel domain III-capsid chimeric protein with the goal of obtaining a molecule potentially able to induce both humoral and cell-mediated immunity (CMI). After expression of the recombinant gene in Escherichia coli, the domain III moiety retained its antigenicity as evaluated with anti-dengue sera. In order to explore alternatives for modulating the immunogenicity of the protein, it was mixed with oligodeoxynucleotides in order to obtain particulated aggregates and then immunologically evaluated in mice in comparison with non-aggregated controls. Although the humoral immune response induced by both forms of the protein was equivalent, the aggregated variant resulted in a much stronger CMI as measured by in vitro IFN-gamma secretion and protection experiments, mediated by CD4(+) and CD8(+) cells. The present work provides additional evidence in support for a crucial role of CMI in protection against dengue virus and describes a novel vaccine candidate against the disease based on a recombinant protein that can stimulate both arms of the acquired immune system.

  2. Aggregations in Flatworms.

    ERIC Educational Resources Information Center

    Liffen, C. L.; Hunter, M.

    1980-01-01

    Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

  3. Unbonded Aggregate Surface Roads

    DTIC Science & Technology

    2006-12-01

    are sufficiently angular and rough in texture, thus ensuring mixture stability. A popular asphalt mixture design method called Superpave Level 1...would not pass either of the Superpave aggregate requirements. Table 18 Additional Characteristics for the Fine Fraction Abbreviated Common Name...CBR values when compacted wet of optimum. This is likely attributable to their relatively high permeabilities . For soaked CBR tests, the aggregates

  4. Erosion of dust aggregates

    NASA Astrophysics Data System (ADS)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-12-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force, which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 ms-1 and above. Though fractal aggregates as formed during the first growth phase are most susceptible to erosion, we observe erosion of aggregates with rather compact surfaces as well. Conclusions: We find that bombarding a larger target aggregate with small projectiles results in erosion for impact velocities as low as a few ms-1. More compact aggregates suffer less from erosion. With increasing projectile size the transition from accretion to erosion is shifted to higher velocities. This allows larger bodies to grow through high velocity collisions with smaller aggregates.

  5. Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

    PubMed Central

    Römling, Ute; Galperin, Michael Y.

    2015-01-01

    Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

  6. [Sugar Chain Construction of Functional Natural Products Using Plant Glucosyltransferases].

    PubMed

    Mizukami, Hajime

    2015-01-01

      Plant secondary product glycosyltransferases belong to family 1 of the glycosyltransferase superfamily and mediate the transfer of a glycosyl residue from activated nucleotide sugars to lipophilic small molecules, thus affecting the solubility, stability and pharmacological activities of the sugar-accepting compounds. The biotechnological application of plant glycosyltransferases in glycoside synthesis has attracted attention because enzymatic glycosylation offers several advantages over chemical methods, including (1) avoiding the use of harsh conditions and toxic catalysts, (2) providing strict control of regio-and stereo-selectivity and (3) high efficiency. This review describes the in vivo and in vitro glycosylation of natural organic compounds using glycosyltransferases, focusing on our investigation of enzymatic synthesis of curcumin glycosides. Our current efforts toward functional characterization of some glycosyltransferases involved in the biosynthesis of iridoids and crocin, as well as in the sugar chain elongation of quercetin glucosides, are described. Finally, I describe the relationship of the structure of sugar chains and the intestinal absorption which was investigated using chemoenzymatically synthesized quercetin glycosides.

  7. Estimating economic value of agricultural water under changing conditions and the effects of spatial aggregation.

    PubMed

    Medellín-Azuara, Josué; Harou, Julien J; Howitt, Richard E

    2010-11-01

    Given the high proportion of water used for agriculture in certain regions, the economic value of agricultural water can be an important tool for water management and policy development. This value is quantified using economic demand curves for irrigation water. Such demand functions show the incremental contribution of water to agricultural production. Water demand curves are estimated using econometric or optimisation techniques. Calibrated agricultural optimisation models allow the derivation of demand curves using smaller datasets than econometric models. This paper introduces these subject areas then explores the effect of spatial aggregation (upscaling) on the valuation of water for irrigated agriculture. A case study from the Rio Grande-Rio Bravo Basin in North Mexico investigates differences in valuation at farm and regional aggregated levels under four scenarios: technological change, warm-dry climate change, changes in agricultural commodity prices, and water costs for agriculture. The scenarios consider changes due to external shocks or new policies. Positive mathematical programming (PMP), a calibrated optimisation method, is the deductive valuation method used. An exponential cost function is compared to the quadratic cost functions typically used in PMP. Results indicate that the economic value of water at the farm level and the regionally aggregated level are similar, but that the variability and distributional effects of each scenario are affected by aggregation. Moderately aggregated agricultural production models are effective at capturing average-farm adaptation to policy changes and external shocks. Farm-level models best reveal the distribution of scenario impacts.

  8. Marine particle aggregate breakup in turbulent flows

    NASA Astrophysics Data System (ADS)

    Rau, Matthew; Ackleson, Steven; Smith, Geoffrey

    2016-11-01

    The dynamics of marine particle aggregate formation and breakup due to turbulence is studied experimentally. Aggregates of clay particles, initially in a quiescent aggregation tank, are subjected to fully developed turbulent pipe flow at Reynolds numbers of up to 25,000. This flow arrangement simulates the exposure of marine aggregates in coastal waters to a sudden turbulent event. Particle size distributions are measured by in-situ sampling of the small-angle forward volume scattering function and the volume concentration of the suspended particulate matter is quantified through light attenuation measurements. Results are compared to measurements conducted under laminar and turbulent flow conditions. At low shear rates, larger sized particles indicate that aggregation initially governs the particle dynamics. Breakup is observed when large aggregates are exposed to the highest levels of shear in the experiment. Models describing the aggregation and breakup rates of marine particles due to turbulence are evaluated with the population balance equation and results from the simulation and experiment are compared. Additional model development will more accurately describe aggregation dynamics for remote sensing applications in turbulent marine environments.

  9. Molecular dynamics simulation of fractal aggregate diffusion

    NASA Astrophysics Data System (ADS)

    Pranami, Gaurav; Lamm, Monica H.; Vigil, R. Dennis

    2010-11-01

    The diffusion of fractal aggregates constructed with the method by Thouy and Jullien [J. Phys. A 27, 2953 (1994)10.1088/0305-4470/27/9/012] comprised of Np spherical primary particles was studied as a function of the aggregate mass and fractal dimension using molecular dynamics simulations. It is shown that finite-size effects have a strong impact on the apparent value of the diffusion coefficient (D) , but these can be corrected by carrying out simulations using different simulation box sizes. Specifically, the diffusion coefficient is inversely proportional to the length of a cubic simulation box, and the constant of proportionality appears to be independent of the aggregate mass and fractal dimension. Using this result, it is possible to compute infinite dilution diffusion coefficients (Do) for aggregates of arbitrary size and fractal dimension, and it was found that Do∝Np-1/df , as is often assumed by investigators simulating Brownian aggregation of fractal aggregates. The ratio of hydrodynamic radius to radius of gyration is computed and shown to be independent of mass for aggregates of fixed fractal dimension, thus enabling an estimate of the diffusion coefficient for a fractal aggregate based on its radius of gyration.

  10. Flow Partitioning in Fully Saturated Soil Aggregates

    SciTech Connect

    Yang, Xiaofan; Richmond, Marshall C.; Scheibe, Timothy D.; Perkins, William A.; Resat, Haluk

    2014-03-30

    Microbes play an important role in facilitating organic matter decomposition in soils, which is a major component of the global carbon cycle. Microbial dynamics are intimately coupled to environmental transport processes, which control access to labile organic matter and other nutrients that are needed for the growth and maintenance of microorganisms. Transport of soluble nutrients in the soil system is arguably most strongly impacted by preferential flow pathways in the soil. Since the physical structure of soils can be characterized as being formed from constituent micro aggregates which contain internal porosity, one pressing question is the partitioning of the flow among the “inter-aggregate” and “intra-aggregate” pores and how this may impact overall solute transport within heterogeneous soil structures. The answer to this question is particularly important in evaluating assumptions to be used in developing upscaled simulations based on highly-resolved mechanistic models. We constructed a number of diverse multi-aggregate structures with different packing ratios by stacking micro-aggregates containing internal pores and varying the size and shape of inter-aggregate pore spacing between them. We then performed pore-scale flow simulations using computational fluid dynamics methods to determine the flow patterns in these aggregate-of-aggregates structures and computed the partitioning of the flow through intra- and inter-aggregate pores as a function of the spacing between the aggregates. The results of these numerical experiments demonstrate that soluble nutrients are largely transported via flows through inter-aggregate pores. Although this result is consistent with intuition, we have also been able to quantify the relative flow capacity of the two domains under various conditions. For example, in our simulations, the flow capacity through the aggregates (intra-aggregate flow) was less than 2% of the total flow when the spacing between the aggregates

  11. Acetal phosphatidic acids: novel platelet aggregating agents.

    PubMed

    Brammer, J P; Maguire, M H; Walaszek, E J; Wiley, R A

    1983-05-01

    induce platelet aggregation per se by direct action at the platelet membrane, and that the acetal function is of primary importance in their potent platelet-stimulating activity. Moreover, as the acetal phosphatidic acids are the major components of the smooth muscle-contracting acidic phospholipid tissue extract ;Darmstoff' (Vogt, 1949), their potent platelet-aggregating properties may be of physiological or pathological significance.

  12. Study on Capturing Functional Requirements of the New Product Based on Evolution

    NASA Astrophysics Data System (ADS)

    Liu, Fang; Song, Liya; Bai, Zhonghang; Zhang, Peng

    In order to exist in an increasingly competitive global marketplace, it is important for corporations to forecast the evolutionary direction of new products rapidly and effectively. Most products in the world are developed based on the design of existing products. In the product design, capturing functional requirements is a key step. Function is continuously evolving, which is driven by the evolution of needs and technologies. So the functional requirements of new product can be forecasted based on the functions of existing product. Eight laws of function evolution are put forward in this paper. The process model of capturing the functional requirements of new product based on function evolution is proposed. An example illustrates the design process.

  13. Assessing the transferability of ecosystem service production estimates and functions

    EPA Science Inventory

    Estimates of ecosystem service (ES) production, and their responses to stressors or policy actions, may be obtained by direct measurement, other empirical studies, or modeling. Direct measurement is costly and often impractical, and thus many studies transfer ES production estim...

  14. Evaluation Strategies as a Function of Product Development Stages.

    ERIC Educational Resources Information Center

    Hess, Robert J.; Wright, William J.

    There are issues in evaluation and stages of product development that demand the use of experimental or quasi-experimental designs. To counteract criticism of evaluation efforts, an approach to the examination of the multiple issues involved in curriculum product evaluation across the usual developmental cycle of educational products was…

  15. Charged Dust Aggregate Interactions

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  16. Glycation in Demetalated Superoxide Dismutase 1 Prevents Amyloid Aggregation and Produces Cytotoxic Ages Adducts

    PubMed Central

    Sirangelo, Ivana; Vella, Filomena M.; Irace, Gaetano; Manco, Giuseppe; Iannuzzi, Clara

    2016-01-01

    Superoxide dismutase 1 (SOD1) has been implicated with familial amyotrophic lateral sclerosis (fALS) through accumulation of protein amyloid aggregates in motor neurons of patients. Amyloid aggregates and protein inclusions are a common pathological feature of many neurological disorders in which protein aggregation seems to be directly related to neurotoxicity. Although, extensive studies performed on the aggregation process of several amyloidogenic proteins in vitro allowed the identification of many physiological factors involved, the molecular mechanisms underlying the formation of amyloid aggregates in vivo and in pathological conditions are still poorly understood. Post-translational modifications are known to affect protein structure and function and, recently, much attention has been devoted to the role played by non-enzymatic glycation in stimulating amyloid aggregation and cellular toxicity. In particular, glycation seems to have a determining role both in sporadic and familial forms of ALS and SOD1 has been shown to be glycated in vivo The aim of this study was to investigate the role of glycation on the amyloid aggregation process of both wild-type SOD1 and its ALS-related mutant G93A. To this aim, the glycation kinetics of both native and demetalated SOD have been followed using two different glycating agents, i.e., D-ribose and methylglyoxal. The effect of glycation on the structure and the amyloid aggregation propensity of native and ApoSOD has been also investigated using a combination of biophysical and biochemical techniques. In addition, the effect of SOD glycated species on cellular toxicity and reactive oxygen species (ROS) production has been evaluated in different cellular models. The results provided by this study contribute to clarify the role of glycation in amyloid aggregation and suggest a direct implication of glycation in the pathology of fALS. PMID:27695694

  17. Oxidation of an Exposed Methionine Instigates the Aggregation of Glyceraldehyde-3-phosphate Dehydrogenase*

    PubMed Central

    Samson, Andre L.; Knaupp, Anja S.; Kass, Itamar; Kleifeld, Oded; Marijanovic, Emilia M.; Hughes, Victoria A.; Lupton, Chris J.; Buckle, Ashley M.; Bottomley, Stephen P.; Medcalf, Robert L.

    2014-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a ubiquitous and abundant protein that participates in cellular energy production. GAPDH normally exists in a soluble form; however, following necrosis, GAPDH and numerous other intracellular proteins convert into an insoluble disulfide-cross-linked state via the process of “nucleocytoplasmic coagulation.” Here, free radical-induced aggregation of GAPDH was studied as an in vitro model of nucleocytoplasmic coagulation. Despite the fact that disulfide cross-linking is a prominent feature of GAPDH aggregation, our data show that it is not a primary rate-determining step. To identify the true instigating event of GAPDH misfolding, we mapped the post-translational modifications that arise during its aggregation. Solvent accessibility and energy calculations of the mapped modifications within the context of the high resolution native GAPDH structure suggested that oxidation of methionine 46 may instigate aggregation. We confirmed this by mutating methionine 46 to leucine, which rendered GAPDH highly resistant to free radical-induced aggregation. Molecular dynamics simulations suggest that oxidation of methionine 46 triggers a local increase in the conformational plasticity of GAPDH that likely promotes further oxidation and eventual aggregation. Hence, methionine 46 represents a “linchpin” whereby its oxidation is a primary event permissive for the subsequent misfolding, aggregation, and disulfide cross-linking of GAPDH. A critical role for linchpin residues in nucleocytoplasmic coagulation and other forms of free radical-induced protein misfolding should now be investigated. Furthermore, because disulfide-cross-linked aggregates of GAPDH arise in many disorders and because methionine 46 is irrelevant to native GAPDH function, mutation of methionine 46 in models of disease should allow the unequivocal assessment of whether GAPDH aggregation influences disease progression. PMID:25086035

  18. Aggregate and the environment

    USGS Publications Warehouse

    Langer, William H.; Drew, Lawrence J.; Sachs, J.S.

    2004-01-01

    This book is designed to help you understand our aggregate resources-their importance, where they come from, how they are processed for our use, the environmental concerns related to their mining and processing, how those concerns are addressed, and the policies and regulations designed to safeguard workers, neighbors, and the environment from the negative impacts of aggregate mining. We hope this understanding will help prepare you to be involved in decisions that need to be made-individually and as a society-to be good stewards of our aggregate resources and our living planet.

  19. Bioactive peptides from meat muscle and by-products: generation, functionality and application as functional ingredients.

    PubMed

    Lafarga, Tomas; Hayes, Maria

    2014-10-01

    Bioactive peptides are sequences of between 2-30 amino acids in length that impart a positive health effect to the consumer when ingested. They have been identified from a range of foods, including milk and muscle sources including beef, chicken, pork and marine muscles. The myriad of peptides identified from these sources have known antihypertensive, opioid, antioxidant, antithrombotic and other bioactivities. Indeed, bioactive peptides could play a role in the prevention of diseases associated with the development of metabolic syndrome and mental health diseases. The aim of this work is to present an overview of the bioactive peptides identified in muscle proteins and by-products generated during the processing of meat. The paper looks at the isolation, enrichment and characterisation strategies that have been employed to date to generate bioactive peptides and the potential future applications of these peptides in functional foods for the prevention of heart and mental health problems and obesity.

  20. Recycling of MSWI fly ash by means of cementitious double step cold bonding pelletization: Technological assessment for the production of lightweight artificial aggregates.

    PubMed

    Colangelo, Francesco; Messina, Francesco; Cioffi, Raffaele

    2015-12-15

    In this work, an extensive study on the recycling of municipal solid waste incinerator fly ash by means of cold bonding pelletization is presented. The ash comes from an incineration plant equipped with rotary and stoker furnaces, in which municipal, hospital and industrial wastes are treated. Fly ash from waste incineration is classified as hazardous and cannot be utilized or even landfilled without prior treatment. The pelletization process uses cement, lime and coal fly ash as components of the binding systems. This process has been applied to several mixes in which the ash content has been varied from 50% (wt.%) up to a maximum of 70%. An innovative additional pelletization step with only cementitious binder has been performed in order to achieve satisfactory immobilization levels. The obtained lightweight porous aggregates are mostly suitable for recovery in the field of building materials with enhanced sustainability properties. Density, water absorption and crushing strength ranged from 1000 to 1600 kg/m(3), 7 to 16% and 1.3 to 6.2 MPa, respectively, and the second pelletization step increased stabilization efficiency. The feasibility of the process has been analyzed by testing also concrete specimens containing the artificial aggregates, resulting in lightweight concrete of average performance.

  1. Effects of tau domain-specific antibodies and intravenous immunoglobulin on tau aggregation and aggregate degradation.

    PubMed

    Esteves-Villanueva, Jose O; Trzeciakiewicz, Hanna; Loeffler, David A; Martić, Sanela

    2015-01-20

    Tau pathology, including neurofibrillary tangles, develops in Alzheimer's disease (AD). The aggregation and hyperphosphorylation of tau are potential therapeutic targets for AD. Administration of anti-tau antibodies reduces tau pathology in transgenic "tauopathy" mice; however, the optimal tau epitopes and conformations to target are unclear. Also unknown is whether intravenous immunoglobulin (IVIG) products, currently being evaluated in AD trials, exert effects on pathological tau. This study examined the effects of anti-tau antibodies targeting different tau epitopes and the IVIG Gammagard on tau aggregation and preformed tau aggregates. Tau aggregation was assessed by transmission electron microscopy and fluorescence spectroscopy, and the binding affinity of the anti-tau antibodies for tau was evaluated by enzyme-linked immunosorbent assays. Antibodies used were anti-tau 1-150 ("D-8"), anti-tau 259-266 ("Paired-262"), anti-tau 341-360 ("A-10"), and anti-tau 404-441 ("Tau-46"), which bind to tau's N-terminus, microtubule binding domain (MBD) repeat sequences R1 and R4, and the C-terminus, respectively. The antibodies Paired-262 and A-10, but not D-8 and Tau-46, reduced tau fibrillization and degraded preformed tau aggregates, whereas the IVIG reduced tau aggregation but did not alter preformed aggregates. The binding affinities of the antibodies for the epitope for which they were specific did not appear to be related to their effects on tau aggregation. These results confirm that antibody binding to tau's MBD repeat sequences may inhibit tau aggregation and indicate that such antibodies may also degrade preformed tau aggregates. In the presence of anti-tau antibodies, the resulting tau morphologies were antigen-dependent. The results also suggested the possibility of different pathways regulating antibody-mediated inhibition of tau aggregation and antibody-mediated degradation of preformed tau aggregates.

  2. Reengineering the Product Assurance Function in DoD.

    DTIC Science & Technology

    1997-02-01

    preventing the loss of skills from not having a home base, as observed at one of the Army installations. 6 2. Functions Become Schools In the lean...IV-2 2. Functions Become Schools ................................................... IV-3 3. Form a New...performed in IPTs in an IPPD environment and the separate functions themselves become schools and policymakers that provide training for the workers

  3. Impact of Particle Aggregation on Nanoparticle Reactivity

    NASA Astrophysics Data System (ADS)

    Jassby, David

    2011-12-01

    nanoparticle that photoluminesces after exposure to UV; TiO2 and ZnO nanoparticles---photocatalytic nanoparticles that generate reactive oxygen species upon UV irradition; and, fullerene nanoparticles used in the filtration experiments, selected for their potential use, small size, and surface chemistry. Our primary methods used to characterize particle and aggregate characteristics include dynamic light scattering used to describe particle size, static light scattering used to characterize aggregate structure (fractal dimension), transmission electron microscopy used to verify primary particle sizes, and electrophoretic mobility measurements to evaluate suspension stability. The reactive property of ZnS that was measured as a function of aggregation was photoluminescence, which was measured using a spectrofluorometer. The reactive property of TiO2 and ZnO that was studied was their ability to generate hydroxyl radicals; these were measured by employing a fluorescent probe that becomes luminescent upon interaction with the hydroxyl radical. To detect the presence of fullerene nanoparticles and calculate removal efficiencies, we used total organic carbon measurements. Additionally, we used UV-vis spectroscopy to approximate the impact of particle shadowing in TiO2 and ZnO aggregates, and Fourier transformed infrared spectroscopy to determine how different electrolytes interact with fullerene surface groups. Our findings indicate that the impact of aggregation on nanoparticle reactivity is material specific. ZnS nanoparticles exhibit a 2-fold increase in band-edge photoluminescence alongside a significant decrease in defect-site photoluminescence. This is attributed to aggregate size-dependent surface tension. Additionally, we used photoluminescence measurements to develop a new method for calculating the critical coagulation concentration of a nanoparticle suspension. The ability of both TiO2 and ZnO to generate hydroxyl radicals was significantly hampered by aggregation. The

  4. Protein aggregation in salt solutions

    PubMed Central

    Kastelic, Miha; Kalyuzhnyi, Yurij V.; Hribar-Lee, Barbara; Dill, Ken A.; Vlachy, Vojko

    2015-01-01

    Protein aggregation is broadly important in diseases and in formulations of biological drugs. Here, we develop a theoretical model for reversible protein–protein aggregation in salt solutions. We treat proteins as hard spheres having square-well-energy binding sites, using Wertheim’s thermodynamic perturbation theory. The necessary condition required for such modeling to be realistic is that proteins in solution during the experiment remain in their compact form. Within this limitation our model gives accurate liquid–liquid coexistence curves for lysozyme and γ IIIa-crystallin solutions in respective buffers. It provides good fits to the cloud-point curves of lysozyme in buffer–salt mixtures as a function of the type and concentration of salt. It than predicts full coexistence curves, osmotic compressibilities, and second virial coefficients under such conditions. This treatment may also be relevant to protein crystallization. PMID:25964322

  5. Refining aggregate exposure: example using parabens.

    PubMed

    Cowan-Ellsberry, Christina E; Robison, Steven H

    2009-12-01

    The need to understand and estimate quantitatively the aggregate exposure to ingredients used broadly in a variety of product types continues to grow. Currently aggregate exposure is most commonly estimated by using a very simplistic approach of adding or summing the exposures from all the individual product types in which the chemical is used. However, the more broadly the ingredient is used in related consumer products, the more likely this summation will result in an unrealistic estimate of exposure because individuals in the population vary in their patterns of product use including co-use and non-use. Furthermore the ingredient may not be used in all products of a given type. An approach is described for refining this aggregate exposure using data on (1) co-use and non-use patterns of product use, (2) extent of products in which the ingredient is used and (3) dermal penetration and metabolism. This approach and the relative refinement in the aggregate exposure from incorporating these data is illustrated using methyl, n-propyl, n-butyl and ethyl parabens, the most widely used preservative system in personal care and cosmetic products. When these refining factors were used, the aggregate exposure compared to the simple addition approach was reduced by 51%, 58%, 90% and 92% for methyl, n-propyl, n-butyl and ethyl parabens, respectively. Since biomonitoring integrates all sources and routes of exposure, the estimates using this approach were compared to available paraben biomonitoring data. Comparison to the 95th percentile of these data showed that these refined estimates were still conservative by factors of 2-92. All of our refined estimates of aggregate exposure are less than the ADI of 10mg/kg/day for parabens.

  6. The Historical Role of the Production Function in Economics and Business

    ERIC Educational Resources Information Center

    Gordon, David; Vaughan, Richard

    2011-01-01

    The production function explains a basic technological relationship between scarce resources, or inputs, and output. This paper offers a brief overview of the historical significance and operational role of the production function in business and economics. The origin and development of this function over time is initially explored. Several…

  7. Marine aggregate dynamics

    NASA Astrophysics Data System (ADS)

    The direction and scope of the Office of Naval Research's Marine Aggregate Dynamics Accelerated Research Initiative will be the topic of an open-house style meeting February 14, 7:30-10:00 P.M. in Ballroom D of the Hyatt Regency New Orleans at the Louisiana Superdome. This meeting is scheduled during the AGU/American Society of Limnology and Oceanography Ocean Sciences Meeting February 12-16 in New Orleans.The critical focus of the ARI is the measurement and modeling of the dynamics of the biological, physical, chemical and molecular processes that drive aggregation and produce aggregates. This new ARI will provide funding in Fiscal Years 1991-1995 to identify and quantify mechanisms that determine the distribution, abundance and size spectrum of aggregated particulate matter in the ocean.

  8. Protein Colloidal Aggregation Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    To investigate the pathways and kinetics of protein aggregation to allow accurate predictive modeling of the process and evaluation of potential inhibitors to prevalent diseases including cataract formation, chronic traumatic encephalopathy, Alzheimer's Disease, Parkinson's Disease and others.

  9. Aggregation and Averaging.

    ERIC Educational Resources Information Center

    Siegel, Irving H.

    The arithmetic processes of aggregation and averaging are basic to quantitative investigations of employment, unemployment, and related concepts. In explaining these concepts, this report stresses need for accuracy and consistency in measurements, and describes tools for analyzing alternative measures. (BH)

  10. Motivation and Productivity as a Function of Corporate Climate.

    ERIC Educational Resources Information Center

    Hellweg, Susan A.

    The current status of productivity and motivation research, particularly as they relate to communication studies and climate studies, is delineated in this paper, largely by a review of literature in these areas. In the section following the introduction, the problems of defining productivity and its relation to performance and communication are…

  11. Investigation of the excitation functions for some medical radioisotopes production

    NASA Astrophysics Data System (ADS)

    Kılınç, Fatma; Karpuz, Nurdan; Çetin, Betül

    2016-11-01

    One of the main application fields of nuclear technology is medicine and radioisotopes are used in medicine. Production of those radioisotopes is important and in the production processes the cross section must be known. All the production of radioisotope used in medicine is based on the nuclear reactions means they are not natural. The decay time of produced radioisotopes is important as from production to hospital can take time and thus generally generator is used to produce some radioisotopes. Radioisotopes are widely produced in reactors or cyclotron type accelerator. Type of radioisotopes direct way to be used in production processes. Thus obtaining of cross section becomes crucial. For this purposes the theoretical calculation cross section of some radioisotopes used in medicine will be calculated in this study. The calculations will be done using Monte Carlo code of TALYS 1.6

  12. Using ecological production functions to link ecological processes to ecosystem services.

    EPA Science Inventory

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively ...

  13. Research of the degradation products of chitosan's angiogenic function

    NASA Astrophysics Data System (ADS)

    Wang, Jianyun; Chen, Yuanwei; Ding, Yulong; Shi, Guoqi; Wan, Changxiu

    2008-11-01

    Angiogenesis is of great importance in tissue engineering and has gained large attention in the past decade. But how it will be influenced by the biodegradable materials, especially their degradation products, remains unknown. Chitosan (CS) is a kind of naturally occurred polysaccharide which can be degraded in physiological environment. In order to gain some knowledge of the influences of CS degradation products on angiogenesis, the interaction of vascular endothelial cells with the degradation products was investigated in the present study. The CS degradation products were prepared by keeping CS sample in physiological saline aseptically at 37 °C for 120 days. Endothelial cells were co-cultured with the degradation products and the angiogenic cell behaviors, including cell proliferation, migration and tube-like structure (TLS) formation, were tested by MTT assay, cell migration quantification method (CMQM), and tube-like structure quantification method (TLSQM) respectively. Furthermore, mRNA expressions of vascular endothelial growth factor (VEGF) and matrix metallo proteinase (MMP-2) were determined by real-time reverse transcriptional polymerase chain reaction (RT-PCR). Physiological saline served as a negative control. As the results showed, the degradation products obtained from 20th to 60th day significantly inhibited the proliferation, migration, and TLS formation of endothelial cells. However, degradation products of the first 14 days and the last 30 days were found to be proangiogenic. At the molecular level, the initial results indicated that the mRNA expressions of VEGF and MMP-2 were increased by the degradation products of 7th day, but were decreased by the ones of 60th day. According to all the results, it could be concluded that the angiogenic behaviors of endothelial cells at both cellular and molecular level could be significantly stimulated or suppressed by the degradation products of CS and the influences are quite time-dependent.

  14. Aggregate breakup in a contracting nozzle.

    PubMed

    Soos, Miroslav; Ehrl, Lyonel; Bäbler, Matthäus U; Morbidelli, Massimo

    2010-01-05

    The breakup of dense aggregates in an extensional flow was investigated experimentally. The flow was realized by pumping the suspension containing the aggregates through a contracting nozzle. Variation of the cluster mass distribution during the breakage process was measured by small-angle light scattering. Because of the large size of primary particles and the dense aggregate structure image analysis was used to determine the shape and structure of the produced fragments. It was found, that neither aggregate structure, characterized by a fractal dimension d(f) = 2.7, nor shape, characterized by an average aspect ratio equal to 1.5, was affected by breakage. Several passes through the nozzle were required to reach the steady state. This is explained by the radial variation of the hydrodynamic stresses at the nozzle entrance, characterized through computational fluid dynamics, which implies that only the fraction of aggregates whose strength is smaller than the local hydrodynamic stress is broken during one pass through the nozzle. Scaling of the steady-state aggregate size as a function of the hydrodynamic stress was used to determine the aggregate strength.

  15. Temperature regulates methane production through the function centralization of microbial community in anaerobic digestion.

    PubMed

    Lin, Qiang; De Vrieze, Jo; He, Guihua; Li, Xiangzhen; Li, Jiabao

    2016-09-01

    Temperature is crucial for the performance of anaerobic digestion process. In this study of anaerobic digestion of swine manure, the relationship between the microbial gene expression and methane production at different temperatures (25-55°C) was revealed through metatranscriptomic analysis. Daily methane production and total biogas production increased with temperature up to 50°C, but decreased at 55°C. The functional gene expression showed great variation at different temperatures. The function centralization (opposite to alpha-diversity), assessed by the least proportions of functional pathways contributing for at least 50% of total reads positively correlated to methane production. Temperature regulated methane production probably through reducing the diversity of functional pathways, but enhancing central functional pathways, so that most of cellular activities and resource were invested in methanogenesis and related pathways, enhancing the efficiency of conversion of substrates to methane. This research demonstrated the importance of function centralization for efficient system functioning.

  16. Dispersion of ferrofluid aggregates in steady flows

    NASA Astrophysics Data System (ADS)

    Williams, Alicia M.; Vlachos, Pavlos P.

    2011-12-01

    Using focused shadowgraphs, we investigate steady flows of a magnetically non-susceptible fluid interacting with ferrofluid aggregates comprised of superparamagnetic nanoparticles. The ferrofluid aggregate is retained at a specific site within the flow channel using two different applied magnetic fields. The bulk flow induces shear stresses on the aggregate, which give rise to the development of interfacial disturbances, leading to Kelvin-Helmholtz (K-H) instabilities and shedding of ferrofluid structures. Herein, the effects of bulk Reynolds number, ranging from 100 to 1000, and maximum applied magnetic fields of 1.2 × 105 and 2.4 × 105 A/m are investigated in the context of their impact on dispersion or removal of material from the core aggregate. The aggregate interaction with steady bulk flow reveals three regimes of aggregate dynamics over the span of Reynolds numbers studied: stable, transitional, and shedding. The first regime is characterized by slight aggregate stretching for low Reynolds numbers, with full aggregate retention. As the Reynolds number increases, the aggregate is in-transition between stable and shedding states. This second regime is characterized by significant initial stretching that gives way to small amplitude Kelvin-Helmholtz waves. Higher Reynolds numbers result in ferrofluid shedding, with Strouhal numbers initially between 0.2 and 0.3, wherein large vortical structures are shed from the main aggregate accompanied by precipitous decay of the accumulated ferrofluid aggregate. These behaviors are apparent for both magnetic field strengths, although the transitional Reynolds numbers are different between the cases, as are the characteristic shedding frequencies relative to the same Reynolds number. In the final step of this study, relevant parameters were extracted from the time series dispersion data to comprehensively quantify aggregate mechanics. The aggregate half-life is found to decrease as a function of the Reynolds number

  17. Rapid Naked‐Eye Discrimination of Cytochrome P450 Genetic Polymorphism through Non‐Crosslinking Aggregation of DNA‐Functionalized Gold Nanoparticles

    PubMed Central

    Akiyama, Yoshitsugu; Wang, Guoqing; Shiraishi, Shota; Kanayama, Naoki; Maeda, Mizuo

    2016-01-01

    Abstract Involvement of single‐nucleotide polymorphism (SNP) genotyping in healthcare should allow for more effective use of pharmacogenomics. However, user‐friendly assays without the requirement of a special instrument still remain unavailable. This study describes naked‐eye SNP discrimination in exon 5 of the human cytochrome P450 2C19 monooxygenase gene, CYP2C19*1 (the wild‐type allele) and CYP2C19*2 (the variant allele with G681A point mutation). The present assay is composed of allele‐specific single‐base primer extension and salt‐induced aggregation of DNA‐modified gold nanoparticles (DNA–AuNPs). Genetic samples extracted from human hair roots are subjected to this assay. The results are verified by direct sequencing. This study should promise the prospective use of DNA–AuNPs in gene diagnosis. PMID:28032016

  18. [Relationship between the spike responses of crayfish mechanoreceptor neurons and the initial functional state and degree of aggregation of their Nissl substance].

    PubMed

    Zaguskin, S L; Kaminskiĭ, I I

    1978-01-01

    The discharges of a single neuron in the crayfish isolated stretch receptor to square standard adequate stimuli were studied. The following parameters were analyzed: response duration, number of impulses per burst, inhibitory pause duration, amplitude and shape of the frequencygram. Preliminary desaggregation of Nissl substance correlated with increase in discharges. When initial frequency of the discharge was low or when the stretch receptor was in resting state, especially in winter time, and the Nissl substance showed high degree of aggregation, discharges to the same stimuli were weaker, and their range diminished. It is suggested that intensified discharges are determined by intracellular redistribution and uptake of calcium which take place during desaggregation of the Nissl substance.

  19. A Novel Method to Quantify Soil Aggregate Stability by Measuring Aggregate Bond Energies

    NASA Astrophysics Data System (ADS)

    Efrat, Rachel; Rawlins, Barry G.; Quinton, John N.; Watts, Chris W.; Whitmore, Andy P.

    2016-04-01

    Soil aggregate stability is a key indicator of soil quality because it controls physical, biological and chemical functions important in cultivated soils. Micro-aggregates are responsible for the long term sequestration of carbon in soil, therefore determine soils role in the carbon cycle. It is thus vital that techniques to measure aggregate stability are accurate, consistent and reliable, in order to appropriately manage and monitor soil quality, and to develop our understanding and estimates of soil as a carbon store to appropriately incorporate in carbon cycle models. Practices used to assess the stability of aggregates vary in sample preparation, operational technique and unit of results. They use proxies and lack quantification. Conflicting results are therefore drawn between projects that do not provide methodological or resultant comparability. Typical modern stability tests suspend aggregates in water and monitor fragmentation upon exposure to an un-quantified amount of ultrasonic energy, utilising a laser granulometer to measure the change in mean weight diameter. In this project a novel approach has been developed based on that of Zhu et al., (2009), to accurately quantify the stability of aggregates by specifically measuring their bond energies. The bond energies are measured operating a combination of calorimetry and a high powered ultrasonic probe, with computable output function. Temperature change during sonication is monitored by an array of probes which enables calculation of the energy spent heating the system (Ph). Our novel technique suspends aggregates in heavy liquid lithium heteropolytungstate, as opposed to water, to avoid exposing aggregates to an immeasurable disruptive energy source, due to cavitation, collisions and clay swelling. Mean weight diameter is measured by a laser granulometer to monitor aggregate breakdown after successive periods of calculated ultrasonic energy input (Pi), until complete dispersion is achieved and bond

  20. Propagation of spectral functions and dilepton production at SIS energies

    SciTech Connect

    Wolf, Gy.; Kaempfer, B.; Zetenyi, M.

    2012-06-15

    The time evolution of vector meson spectral functions is studied within a BUU-type transport model. Applications focus on {rho} and {omega} mesons being important pieces for the interpretation of the dielectron invariant mass spectrum. Since the evolution of the spectral functions is driven by the local density, the inmedium modifications turn out to compete, in this approach, with the known vacuum contributions.

  1. Does Dietary Mitigation of Enteric Methane Production Affect Rumen Function and Animal Productivity in Dairy Cows?

    PubMed Central

    Veneman, Jolien B.; Muetzel, Stefan; Hart, Kenton J.; Faulkner, Catherine L.; Moorby, Jon M.; Perdok, Hink B.; Newbold, Charles J.

    2015-01-01

    It has been suggested that the rumen microbiome and rumen function might be disrupted if methane production in the rumen is decreased. Furthermore concerns have been voiced that geography and management might influence the underlying microbial population and hence the response of the rumen to mitigation strategies. Here we report the effect of the dietary additives: linseed oil and nitrate on methane emissions, rumen fermentation, and the rumen microbiome in two experiments from New Zealand (Dairy 1) and the UK (Dairy 2). Dairy 1 was a randomized block design with 18 multiparous lactating cows. Dairy 2 was a complete replicated 3 x 3 Latin Square using 6 rumen cannulated, lactating dairy cows. Treatments consisted of a control total mixed ration (TMR), supplementation with linseed oil (4% of feed DM) and supplementation with nitrate (2% of feed DM) in both experiments. Methane emissions were measured in open circuit respiration chambers and rumen samples were analyzed for rumen fermentation parameters and microbial population structure using qPCR and next generation sequencing (NGS). Supplementation with nitrate, but not linseed oil, decreased methane yield (g/kg DMI; P<0.02) and increased hydrogen (P<0.03) emissions in both experiments. Furthermore, the effect of nitrate on gaseous emissions was accompanied by an increased rumen acetate to propionate ratio and consistent changes in the rumen microbial populations including a decreased abundance of the main genus Prevotella and a decrease in archaeal mcrA (log10 copies/ g rumen DM content). These results demonstrate that methane emissions can be significantly decreased with nitrate supplementation with only minor, but consistent, effects on the rumen microbial population and its function, with no evidence that the response to dietary additives differed due to geography and different underlying microbial populations. PMID:26509835

  2. Prefoldin prevents aggregation of α-synuclein.

    PubMed

    Takano, Mariko; Tashiro, Erika; Kitamura, Akira; Maita, Hiroshi; Iguchi-Ariga, Sanae M M; Kinjo, Masataka; Ariga, Hiroyoshi

    2013-10-25

    Protein aggregation is observed in various neurodegeneration diseases, including Parkinson's disease (PD). Alpha-synuclein, a causative gene product of familial PD, is a major component of large aggregates (inclusion bodies) in PD. Prefoldin, a molecular chaperone comprised of six subunits, PFD1~6, prevents misfolding of newly synthesized nascent polypeptides and also prevents aggregation of protein such as a pathogenic form of Huntingtin, a causative gene product of Huntington disease. In this study, we first found that aggregation of TagRFP-tagged wild-type α-synuclein and its pathogenic mutants, but not that of GFP-tagged α-synuclein, occurred in transfected Neuro-2a cells. The fluorescence of GFP is weakened under the condition of pH 4.5-5.0, and TagRFP is a stable red fluorescence protein under an acidic condition. Aggregated TagRFP-wild-type α-synuclein and its pathogenic mutants in Neuro-2a cells were ubiquitinated and were colocalized with the prefoldin complex in the lysosome under this condition. Furthermore, knockdown of PFD2 and PFD5 disrupted prefoldin formation in α-synuclein-expressing cells, resulting in accumulation of aggregates of wild-type and pathogenic α-synuclein and in induction of cell death. The levels of aggregation and cell death in pathogenic α-synuclein-transfected cells tended to be higher than those in wild-type α-synuclein-transfected cells. These results suggest that prefoldin works as a protective factor in aggregated α-synuclein-induced cell death.

  3. Fibronectin Aggregation and Assembly

    PubMed Central

    Ohashi, Tomoo; Erickson, Harold P.

    2011-01-01

    The mechanism of fibronectin (FN) assembly and the self-association sites are still unclear and contradictory, although the N-terminal 70-kDa region (I1–9) is commonly accepted as one of the assembly sites. We previously found that I1–9 binds to superfibronectin, which is an artificial FN aggregate induced by anastellin. In the present study, we found that I1–9 bound to the aggregate formed by anastellin and a small FN fragment, III1–2. An engineered disulfide bond in III2, which stabilizes folding, inhibited aggregation, but a disulfide bond in III1 did not. A gelatin precipitation assay showed that I1–9 did not interact with anastellin, III1, III2, III1–2, or several III1–2 mutants including III1–2KADA. (In contrast to previous studies, we found that the III1–2KADA mutant was identical in conformation to wild-type III1–2.) Because I1–9 only bound to the aggregate and the unfolding of III2 played a role in aggregation, we generated a III2 domain that was destabilized by deletion of the G strand. This mutant bound I1–9 as shown by the gelatin precipitation assay and fluorescence resonance energy transfer analysis, and it inhibited FN matrix assembly when added to cell culture. Next, we introduced disulfide mutations into full-length FN. Three disulfide locks in III2, III3, and III11 were required to dramatically reduce anastellin-induced aggregation. When we tested the disulfide mutants in cell culture, only the disulfide bond in III2 reduced the FN matrix. These results suggest that the unfolding of III2 is one of the key factors for FN aggregation and assembly. PMID:21949131

  4. Generation of Soluble Advanced Glycation End Products Receptor (sRAGE)-Binding Ligands during Extensive Heat Treatment of Whey Protein/Lactose Mixtures Is Dependent on Glycation and Aggregation.

    PubMed

    Liu, Fahui; Teodorowicz, Małgorzata; Wichers, Harry J; van Boekel, Martinus A J S; Hettinga, Kasper A

    2016-08-24

    Heating of protein- and sugar-containing materials is considered the primary factor affecting the formation of advanced glycation end products (AGEs). This study aimed to investigate the influence of heating conditions, digestion, and aggregation on the binding capacity of AGEs to the soluble AGE receptor (sRAGE). Samples consisting of mixtures of whey protein and lactose were heated at 130 °C. An in vitro infant digestion model was used to study the influence of heat treatment on the digestibility of whey proteins. The amount of sRAGE-binding ligands before and after digestion was measured by an ELISA-based sRAGE-binding assay. Water activity did not significantly affect the extent of digestibility of whey proteins dry heated at pH 5 (ranging from 3.3 ± 0.2 to 3.6 ± 0.1% for gastric digestion and from 53.5 ± 1.5 to 64.7 ± 1.1% for duodenal digestion), but there were differences in cleavage patterns of peptides among the samples heated at different pH values. Formation of sRAGE-binding ligands depended on the formation of aggregates and was limited in the samples heated at pH 5. Moreover, the sRAGE-binding activity of digested sample was changed by protease degradation and correlated with the digestibility of samples. In conclusion, generation of sRAGE-binding ligands during extensive heat treatment of whey protein/lactose mixtures is limited in acidic heating condition and dependent on glycation and aggregation.

  5. Recent advances in the elucidation of enzymatic function in natural product biosynthesis

    PubMed Central

    Tan, Gao-Yi; Deng, Zixin; Liu, Tiangang

    2016-01-01

    With the successful production of artemisinic acid in yeast, the promising potential of synthetic biology for natural product biosynthesis is now being realized. The recent total biosynthesis of opioids in microbes is considered to be another landmark in this field. The importance and significance of enzymes in natural product biosynthetic pathways have been re-emphasized by these advancements. Therefore, the characterization and elucidation of enzymatic function in natural product biosynthesis are undoubtedly fundamental for the development of new drugs and the heterologous biosynthesis of active natural products. Here, discoveries regarding enzymatic function in natural product biosynthesis over the past year are briefly reviewed. PMID:26989472

  6. Recent advances in the elucidation of enzymatic function in natural product biosynthesis.

    PubMed

    Tan, Gao-Yi; Deng, Zixin; Liu, Tiangang

    2015-01-01

    With the successful production of artemisinic acid in yeast, the promising potential of synthetic biology for natural product biosynthesis is now being realized. The recent total biosynthesis of opioids in microbes is considered to be another landmark in this field. The importance and significance of enzymes in natural product biosynthetic pathways have been re-emphasized by these advancements. Therefore, the characterization and elucidation of enzymatic function in natural product biosynthesis are undoubtedly fundamental for the development of new drugs and the heterologous biosynthesis of active natural products. Here, discoveries regarding enzymatic function in natural product biosynthesis over the past year are briefly reviewed.

  7. Direct Imaging of Carboxymethyl Cellulose-mediated Aggregation of Lactic Acid Bacteria Using Dark-field Microscopy.

    PubMed

    Nakao, Hidenobu; Saito, Katsuichi; Tomita, Satoru; Magariyama, Yukio; Kaizuka, Yoshihisa; Takeda, Yoshihiko

    2016-01-01

    The ecological functions of lactic acid bacteria (LAB) have been utilized in human life for food processing and probiotic therapy. Understanding the interaction mechanisms between LAB and food ingredients may help to clarify the fermentation process and physiological functions of LAB in the production of fermented foods made from plant materials and dairy products. However, the interaction mechanisms have yet to be fully clarified. Although laser diffraction was used for measuring the size changes of aggregates caused by the interaction between LAB and food ingredients, aggregate sizes could not be determined because of the precipitation of aggregates and its disruption from stirring. Therefore, a microscopy-based method for directly visualizing their interactions is required. We directly observed aggregation processes of LAB cells mediated by water-soluble polysaccharides, carboxymethyl cellulose (CMC), by dark-filed microscopy (DFM). DFM could visualize CMC-mediated cell aggregation with high contrast in real time, and revealed that the aggregates were formed by repeated collisions of LAB cells in a suspension. This suggests that our method can be used as a useful assay to directly visualize grain formation caused by interactions between LAB cells and various polysaccharides in food ingredients.

  8. Nanoscale Ionic Aggregate Morphology in Zwitterionic Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Huyck, Rebecca; Salas-de La Cruz, David; Long, Timothy E.; Winey, Karen I.

    2009-03-01

    The morphology of two different zwitterionic copolymers, poly(sulfobetaine methacrylate-ran-butyl acrylate), and poly(sulfobetaine methacrylamide-ran-butyl acrylate) are investigated as a function of the mol % content of SBMA (7 and 9 mol %) and SBMAm (6, 10 and 13 mol %), respectively. In both copolymers, X-ray scattering results show a new structure in the material arising from ionic aggregates. The sizes of the ionic aggregates are obtained through the scattering model. The sizes of the ionic aggregates increase as the ion content increases. The application of scanning transmission electron microscopy to the study of ionomer morphology has enabled direct, model-independent visualization of the ionic aggregates. The correlation between X-ray scattering results and the real space imaging for morphology of these zwitterionic copolymers will be presented.

  9. Aggregated Gas Molecules: Toxic to Protein?

    PubMed Central

    Zhang, Meng; Zuo, Guanghong; Chen, Jixiu; Gao, Yi; Fang, Haiping

    2013-01-01

    The biological toxicity of high levels of breathing gases has been known for centuries, but the mechanism remains elusive. Earlier work mainly focused on the influences of dispersed gas molecules dissolved in water on biomolecules. However, recent studies confirmed the existence of aggregated gas molecules at the water-solid interface. In this paper, we have investigated the binding preference of aggregated gas molecules on proteins with molecular dynamics simulations, using nitrogen (N2) gas and the Src-homology 3 (SH3) domain as the model system. Aggregated N2 molecules were strongly bound by the active sites of the SH3 domain, which could impair the activity of the protein. In contrast, dispersed N2 molecules did not specifically interact with the SH3 domain. These observations extend our understanding of the possible toxicity of aggregates of gas molecules in the function of proteins. PMID:23588597

  10. Silt-clay aggregates on Mars

    NASA Technical Reports Server (NTRS)

    Greeley, R.

    1979-01-01

    Viking observations suggest abundant silt and clay particles on Mars. It is proposed that some of these particles agglomerate to form sand size aggregates that are redeposited as sandlike features such as drifts and dunes. Although the binding for the aggregates could include salt cementation or other mechanisms, electrostatic bonding is considered to be a primary force holding the aggregates together. Various laboratory experiments conducted since the 19th century, and as reported here for simulated Martian conditions, show that both the magnitude and sign of electrical charges on windblown particles are functions of particle velocity, shape and composition, atmospheric pressure, atmospheric composition and other factors. Electrical charges have been measured for saltating particles in the wind tunnel and in the field, on the surfaces of sand dunes, and within dust clouds on earth. Similar, and perhaps even greater, charges are proposed to occur on Mars, which could form aggregates of silt and clay size particles

  11. From static micrographs to particle aggregation dynamics in three dimensions.

    PubMed

    Häbel, H; Särkkä, A; Rudemo, M; Hamngren Blomqvist, C; Olsson, E; Abrahamsson, C; Nordin, M

    2016-04-01

    Studies on colloidal aggregation have brought forth theories on stability of colloidal gels and models for aggregation dynamics. Still, a complete link between developed frameworks and obtained laboratory observations has to be found. In this work, aggregates of silica nanoparticles (20 nm) are studied using diffusion limited cluster aggregation (DLCA) and reaction limited cluster aggregation (RLCA) models. These processes are driven by the probability of particles to aggregate upon collision. This probability of aggregation is one in the DLCA and close to zero in the RLCA process. We show how to study the probability of aggregation from static micrographs on the example of a silica nanoparticle gel at 9 wt%. The analysis includes common summary functions from spatial statistics, namely the empty space function and Ripley's K-function, as well as two newly developed summary functions for cluster analysis based on graph theory. One of the new cluster analysis functions is related to the clustering coefficient in communication networks and the other to the size of a cluster. All four topological summary statistics are used to quantitatively compare in plots and in a least-square approach experimental data to cluster aggregation simulations with decreasing probabilities of aggregation. We study scanning transmission electron micrographs and utilize the intensity-mass thickness relation present in such images to create comparable micrographs from three-dimensional simulations. Finally, a characterization of colloidal silica aggregates and simulated structures is obtained, which allows for an evaluation of the cluster aggregation process for different aggregation scenarios. As a result, we find that the RLCA process fits the experimental data better than the DLCA process.

  12. Consumers' acceptance and preferences for nutrition-modified and functional dairy products: A systematic review.

    PubMed

    Bimbo, Francesco; Bonanno, Alessandro; Nocella, Giuseppe; Viscecchia, Rosaria; Nardone, Gianluca; De Devitiis, Biagia; Carlucci, Domenico

    2017-06-01

    This systematic literature review collects and summarizes research on consumer acceptance and preferences for nutrition-modified and functional dairy products, to reconcile, and expand upon, the findings of previous studies. We find that female consumers show high acceptance for some functional dairy products, such as yogurt enriched with calcium, fiber and probiotics. Acceptance for functional dairy products increases among consumers with higher diet/health related knowledge, as well as with aging. General interest in health, food-neophobia and perceived self-efficacy seem also to contribute shaping the acceptance for functional dairy products. Furthermore, products with "natural" matches between carriers and ingredients have the highest level of acceptance among consumers. Last, we find that brand familiarity drives consumers with low interest in health to increase their acceptance and preference for health-enhanced dairy products, such as probiotic yogurts, or those with a general function claim.

  13. Prediction and reduction of the aggregation of monoclonal antibodies.

    PubMed

    van der Kant, Rob; Karow-Zwick, Anne R; Van Durme, Joost; Blech, Michaela; Gallardo, Rodrigo; Seeliger, Daniel; Aßfalg, Kerstin; Baatsen, Pieter; Compernolle, Griet; Gils, Ann; Studts, Joey M; Schulz, Patrick; Garidel, Patrick; Schymkowitz, Joost; Rousseau, Frederic

    2017-03-17

    Protein aggregation remains a major area of focus in the production of monoclonal antibodies. Improving the intrinsic properties of antibodies can improve manufacturability, attrition rates, safety, formulation, titers, immunogenicity and solubility. Here, we explore the potential of predicting and reducing the aggregation propensity of monoclonal antibodies, based on the identification of aggregation-prone regions (APRs) and their contribution to the thermodynamic stability of the protein. Although APRs are thought to occur in the antigen binding region to drive hydrophobic binding with antigen, we were able to rationally design variants that display a marked decrease in aggregation propensity while retaining antigen binding through the introduction of artificial aggregation gatekeeper residues. The reduction in aggregation propensity was accompanied by an increase in expression titer, showing that reducing protein aggregation is beneficial throughout the development process. The data presented show that this approach can significantly reduce liabilities in novel therapeutic antibodies and proteins, leading to a more efficient path to clinical studies.

  14. Strength of masonry blocks made with recycled concrete aggregates

    NASA Astrophysics Data System (ADS)

    Matar, Pierre; Dalati, Rouba El

    The idea of recycling concrete of demolished buildings aims at preserving the environment. Indeed, the reuse of concrete as aggregate in new concrete mixes helped to reduce the expenses related to construction and demolition (C&D) waste management and, especially, to protect the environment by reducing the development rate of new quarries. This paper presents the results of an experimental study conducted on masonry blocks containing aggregates resulting from concrete recycling. The purpose of this study is to investigate the effect of recycled aggregates on compressive strength of concrete blocks. Tests were performed on series of concrete blocks: five series each made of different proportions of recycled aggregates, and one series of reference blocks exclusively composed of natural aggregates. Tests showed that using recycled aggregates with addition of cement allows the production of concrete blocks with compressive strengths comparable to those obtained on concrete blocks made exclusively of natural aggregates.

  15. Study of production functions for modeling forest biomass: An area for research

    SciTech Connect

    Nautiyal, J.C. ); Belli, K.L. )

    1989-09-01

    The usefulness of production functions, mathematical descriptions of production processes, has long been recognized by economists in manufacturing industries, and more recently by agricultural scientists in the field of biological production. As increasing emphasis in forestry is placed on short-rotation, intensive crop management it would seem that foresters would also require production functions for rational timber management planning. These functions could be useful in a number of areas such as: crop tree growth prediction, control of stand development, economic analysis for decision-making purposes, and for determining the so-called elasticities of inputs and outputs. A very general functional form that may be appropriate for the development of forestry models is the transcendental logarithmic, or translog, function. Unfortunately, at this time, sufficiently detailed data do not seem to be available for any tree species to estimate a production function that could make sophisticated intensive forest management possible.

  16. Fungal Laccases: Production, Function, and Applications in Food Processing

    PubMed Central

    Brijwani, Khushal; Rigdon, Anne; Vadlani, Praveen V.

    2010-01-01

    Laccases are increasingly being used in food industry for production of cost-effective and healthy foods. To sustain this trend widespread availability of laccase and efficient production systems have to be developed. The present paper delineate the recent developments that have taken place in understanding the role of laccase action, efforts in overexpression of laccase in heterologous systems, and various cultivation techniques that have been developed to efficiently produce laccase at the industrial scale. The role of laccase in different food industries, particularly the recent developments in laccase application for food processing, is discussed. PMID:21048859

  17. Reusing recycled aggregates in structural concrete

    NASA Astrophysics Data System (ADS)

    Kou, Shicong

    results, a number of recommendations were made on how to optimize the use of recycled aggregates for structural concrete production. The results demonstrate that one of the practical ways to utilize a higher percentage of recycled aggregates in concrete is "precasting" with the use of fly ash and an initial steam curing stage immediately after casting.

  18. Properties of amaranth flour with functional oat products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amaranth flour containing the essential amino acid, lysine, was composited with oat products that contain ß-glucan known for lowering blood cholesterol and preventing heart disease. The pasting and rheological properties of amaranth-oat composites were evaluated. The amaranth-Nutrim composites showe...

  19. Cell Viability and Functionality of Probiotic Bacteria in Dairy Products

    PubMed Central

    Vinderola, Gabriel; Binetti, Ana; Burns, Patricia; Reinheimer, Jorge

    2011-01-01

    Probiotic bacteria, according to the definition adopted by the World Health Organization in 2002, are live microorganisms, which when administered in adequate amounts confer a health benefit to the host. Recent studies show that the same probiotic strain produced and/or preserved under different storage conditions, may present different responses regarding their susceptibility to the adverse conditions of the gastrointestinal tract, its capacity to adhere to the intestinal epithelium, or its immunomodulating capacity, the functionality being affected without changes in cell viability. This could imply that the control of cell viability is not always enough to guarantee the functionality (probiotic capacity) of a strain. Therefore, a new challenge arises for food technologists and microbiologists when it comes to designing and monitoring probiotic food: to be able to monitor the functionality of a probiotic microorganism throughout all the stages the strain goes through from the moment it is produced and included in the food vehicle, until the moment of consumption. Conventional methodological tools or others still to be developed must be used. The application of cell membrane functionality markers, the use of tests of resistance to intestinal barriers, the study of surface properties and the application of in vivo models come together as complementary tools to assess the actual capacity of a probiotic organism in a specific food, to exert functional effects regardless of the number of viable cells present at the moment of consumption. PMID:21833320

  20. Cell viability and functionality of probiotic bacteria in dairy products.

    PubMed

    Vinderola, Gabriel; Binetti, Ana; Burns, Patricia; Reinheimer, Jorge

    2011-01-01

    Probiotic bacteria, according to the definition adopted by the World Health Organization in 2002, are live microorganisms, which when administered in adequate amounts confer a health benefit to the host. Recent studies show that the same probiotic strain produced and/or preserved under different storage conditions, may present different responses regarding their susceptibility to the adverse conditions of the gastrointestinal tract, its capacity to adhere to the intestinal epithelium, or its immunomodulating capacity, the functionality being affected without changes in cell viability. This could imply that the control of cell viability is not always enough to guarantee the functionality (probiotic capacity) of a strain. Therefore, a new challenge arises for food technologists and microbiologists when it comes to designing and monitoring probiotic food: to be able to monitor the functionality of a probiotic microorganism throughout all the stages the strain goes through from the moment it is produced and included in the food vehicle, until the moment of consumption. Conventional methodological tools or others still to be developed must be used. The application of cell membrane functionality markers, the use of tests of resistance to intestinal barriers, the study of surface properties and the application of in vivo models come together as complementary tools to assess the actual capacity of a probiotic organism in a specific food, to exert functional effects regardless of the number of viable cells present at the moment of consumption.

  1. Generation of urban road dust from anti-skid and asphalt concrete aggregates.

    PubMed

    Tervahattu, Heikki; Kupiainen, Kaarle J; Räisänen, Mika; Mäkelä, Timo; Hillamo, Risto

    2006-04-30

    Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust.

  2. Aggregating Political Dimensions: Of the Feasibility of Political Indicators

    ERIC Educational Resources Information Center

    Sanin, Francisco Gutierrez; Buitrago, Diana; Gonzalez, Andrea

    2013-01-01

    Political indicators are widely used in academic writing and decision making, but remain controversial. This paper discusses the problems related to the aggregation functions they use. Almost always, political indicators are aggregated by weighted averages or summations. The use of such functions is based on untenable assumptions (existence of…

  3. A Critical Analysis of the Use of Production Functions in School Finance.

    ERIC Educational Resources Information Center

    Gilman, David A.

    1988-01-01

    This article discusses the uses of production function models and describes the role of inferential statistics for making predictions in school finance. Specifically, the analysis evaluates types, suggests uses, explains the advantages and disadvantages, and lists the statistical complexities of production functions. (JAM)

  4. Technology meets aggregate

    SciTech Connect

    Wilson, C.; Swan, C.

    2007-07-01

    New technology carried out at Tufts University and the University of Massachusetts on synthetic lightweight aggregate has created material from various qualities of fly ash from coal-fired power plants for use in different engineered applications. In pilot scale manufacturing tests an 'SLA' containing 80% fly ash and 20% mixed plastic waste from packaging was produced by 'dry blending' mixed plastic with high carbon fly ash. A trial run was completed to produce concrete masonry unit (CMU) blocks at a full-scale facility. It has been shown that SLA can be used as a partial substitution of a traditional stone aggregate in hot asphalt mix. 1 fig., 2 photos.

  5. A novel tetravalent formulation combining the four aggregated domain III-capsid proteins from dengue viruses induces a functional immune response in mice and monkeys.

    PubMed

    Suzarte, Edith; Gil, Lázaro; Valdés, Iris; Marcos, Ernesto; Lazo, Laura; Izquierdo, Alienys; García, Angélica; López, Lázaro; Álvarez, Maylin; Pérez, Yusleydis; Castro, Jorge; Romero, Yaremis; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

    2015-08-01

    Our group developed a subunit vaccine candidate against dengue virus based on two different viral regions: the domain III of the envelope protein and the capsid protein. The novel chimeric protein from dengue-2 virus [domain III-capsid (DIIIC-2)], when presented as aggregated incorporating oligodeoxynucleotides, induced anti-viral and neutralizing antibodies, a cellular immune response and conferred significant protection to mice and monkeys. The remaining constructs were already obtained and properly characterized. Based on this evidence, this work was aimed at assessing the immune response in mice of the chimeric proteins DIIIC of each serotype, as monovalent and tetravalent formulations. Here, we demonstrated the immunogenicity of each protein in terms of humoral and cell-mediated immunity, without antigen competition on the mixture forming the formulation tetra DIIIC. Accordingly, significant protection was afforded as measured by the limited viral load in the mouse encephalitis model. The assessment of the tetravalent formulation in non-human primates was also conducted. In this animal model, it was demonstrated that the formulation induced neutralizing antibodies and memory cell-mediated immune response with IFN-γ-secreting and cytotoxic capacity, regardless the route of immunization used. Taken together, we can assert that the tetravalent formulation of DIIIC proteins constitutes a promising vaccine candidate against dengue virus, and propose it for further efficacy experiments in monkeys or in the dengue human infection model, as it has been recently proposed.

  6. Interference between Coulombic and CT-mediated couplings in molecular aggregates: H- to J-aggregate transformation in perylene-based π-stacks

    NASA Astrophysics Data System (ADS)

    Hestand, Nicholas J.; Spano, Frank C.

    2015-12-01

    The spectroscopic differences between J and H-aggregates are traditionally attributed to the spatial dependence of the Coulombic coupling, as originally proposed by Kasha. However, in tightly packed molecular aggregates wave functions on neighboring molecules overlap, leading to an additional charge transfer (CT) mediated exciton coupling with a vastly different spatial dependence. The latter is governed by the nodal patterns of the molecular LUMOs and HOMOs from which the electron (te) and hole (th) transfer integrals derive. The sign of the CT-mediated coupling depends on the sign of the product teth and is therefore highly sensitive to small (sub-Angstrom) transverse displacements or slips. Given that Coulombic and CT-mediated couplings exist simultaneously in tightly packed molecular systems, the interference between the two must be considered when defining J and H-aggregates. Generally, such π-stacked aggregates do not abide by the traditional classification scheme of Kasha: for example, even when the Coulomb coupling is strong the presence of a similarly strong but destructively interfering CT-mediated coupling results in "null-aggregates" which spectroscopically resemble uncoupled molecules. Based on a Frenkel/CT Holstein Hamiltonian that takes into account both sources of electronic coupling as well as intramolecular vibrations, vibronic spectral signatures are developed for integrated Frenkel/CT systems in both the perturbative and resonance regimes. In the perturbative regime, the sign of the lowest exciton band curvature, which rigorously defines J and H-aggregation, is directly tracked by the ratio of the first two vibronic peak intensities. Even in the resonance regime, the vibronic ratio remains a useful tool to evaluate the J or H nature of the system. The theory developed is applied to the reversible H to J-aggregate transformations recently observed in several perylene bisimide systems.

  7. Antibiotic production by soil bacteria: diversity, activity and natural functions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The living components of soils, the micro- and macrobiota, play an essential role in several life support functions as they enable soils to recycle nutrients, inactive contaminants, suppress plant pathogens and serve as a suitable substrate for plant growth. Beneficial bacteria occur naturally in s...

  8. Microstructural characterization of concrete prepared with recycled aggregates.

    PubMed

    Guedes, Mafalda; Evangelista, Luís; de Brito, Jorge; Ferro, Alberto C

    2013-10-01

    Several authors have reported the workability, mechanical properties, and durability of concrete produced with construction waste replacing the natural aggregate. However, a systematic microstructural characterization of recycled aggregate concrete has not been reported. This work studies the use of fine recycled aggregate to replace fine natural aggregate in the production of concrete and reports the resulting microstructures. The used raw materials were natural aggregate, recycled aggregate obtained from a standard concrete, and Portland cement. The substitution extent was 0, 10, 50, and 100 vol%; hydration was stopped at 9, 24, and 96 h and 28 days. Microscopy was focused on the cement/aggregate interfacial transition zone, enlightening the effect of incorporating recycled aggregate on the formation and morphology of the different concrete hydration products. The results show that concretes with recycled aggregates exhibit typical microstructural features of the transition zone in normal strength concrete. Although overall porosity increases with increasing replacement, the interfacial bond is apparently stronger when recycled aggregates are used. An addition of 10 vol% results in a decrease in porosity at the interface with a corresponding increase of the material hardness. This provides an opportunity for development of increased strength Portland cement concretes using controlled amounts of concrete waste.

  9. Discrimination among spawning aggregations of lake herring from Lake Superior using whole-body morphometric characters

    USGS Publications Warehouse

    Hoff, Michael H.

    2004-01-01

    The lake herring (Coregonus artedi) was one of the most commercially and ecologically valuable Lake Superior fishes, but declined in the second half of the 20th century as the result of overharvest of putatively discrete stocks. No tools were previously available that described lake herring stock structure and accurately classified lake herring to their spawning stocks. The accuracy of discriminating among spawning aggregations was evaluated using whole-body morphometrics based on a truss network. Lake herring were collected from 11 spawning aggregations in Lake Superior and two inland Wisconsin lakes to evaluate morphometrics as a stock discrimination tool. Discriminant function analysis correctly classified 53% of all fish from all spawning aggregations, and fish from all but one aggregation were classified at greater rates than were possible by chance. Discriminant analysis also correctly classified 66% of fish to nearest neighbor groups, which were groups that accounted for the possibility of mixing among the aggregations. Stepwise discriminant analysis showed that posterior body length and depth measurements were among the best discriminators of spawning aggregations. These findings support other evidence that discrete stocks of lake herring exist in Lake Superior, and fishery managers should consider all but one of the spawning aggregations as discrete stocks. Abundance, annual harvest, total annual mortality rate, and exploitation data should be collected from each stock, and surplus production of each stock should be estimated. Prudent management of stock surplus production and exploitation rates will aid in restoration of stocks and will prevent a repeat of the stock collapses that occurred in the middle of the 20th century, when the species was nearly extirpated from the lake.

  10. Access to photon fragmentation functions in hadronic jet production

    NASA Astrophysics Data System (ADS)

    Kaufmann, Tom; Mukherjee, Asmita; Vogelsang, Werner

    2016-06-01

    We argue that the process p p →(jet γ )X , for which a photon is observed inside a fully reconstructed jet and is treated as part of the jet, offers new probes of the so far little-known fragmentation functions for photons. We present a next-to-leading-order QCD calculation of the cross section for this process in the limit that the jet is relatively narrow. We also investigate the background resulting from the two-photon decay of neutral pions. We present numerical results relevant for possible measurements at the LHC and at RHIC. These suggest that p p →(jet γ )X should provide clean access to the photon fragmentation functions, provided an efficient suppression of the background is available in experiment.

  11. Concrete Waste Recycling Process for High Quality Aggregate

    SciTech Connect

    Ishikura, Takeshi; Fujii, Shin-ichi

    2008-01-15

    Large amount of concrete waste generates during nuclear power plant (NPP) dismantling. Non-contaminated concrete waste is assumed to be disposed in a landfill site, but that will not be the solution especially in the future, because of decreasing tendency of the site availability and natural resources. Concerning concrete recycling, demand for roadbeds and backfill tends to be less than the amount of dismantled concrete generated in a single rural site, and conventional recycled aggregate is limited of its use to non-structural concrete, because of its inferior quality to ordinary natural aggregate. Therefore, it is vital to develop high quality recycled aggregate for general uses of dismantled concrete. If recycled aggregate is available for high structural concrete, the dismantling concrete is recyclable as aggregate for industry including nuclear field. Authors developed techniques on high quality aggregate reclamation for large amount of concrete generated during NPP decommissioning. Concrete of NPP buildings has good features for recycling aggregate; large quantity of high quality aggregate from same origin, record keeping of the aggregate origin, and little impurities in dismantled concrete such as wood and plastics. The target of recycled aggregate in this development is to meet the quality criteria for NPP concrete as prescribed in JASS 5N 'Specification for Nuclear Power Facility Reinforced Concrete' and JASS 5 'Specification for Reinforced Concrete Work'. The target of recycled aggregate concrete is to be comparable performance with ordinary aggregate concrete. The high quality recycled aggregate production techniques are assumed to apply for recycling for large amount of non-contaminated concrete. These techniques can also be applied for slightly contaminated concrete dismantled from radiological control area (RCA), together with free release survey. In conclusion: a technology on dismantled concrete recycling for high quality aggregate was developed

  12. Growth hormone aggregates in the rat adenohypophysis

    NASA Technical Reports Server (NTRS)

    Farrington, M.; Hymer, W. C.

    1990-01-01

    Although it has been known for some time that GH aggregates are contained within the rat anterior pituitary gland, the role that they might play in pituitary function is unknown. The present study examines this issue using the technique of Western blotting, which permitted visualization of 11 GH variants with apparent mol wt ranging from 14-88K. Electroelution of the higher mol wt variants from gels followed by their chemical reduction with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. With the blot procedure we found 1) that GH aggregates greater than 44K were associated with a 40,000 x g sedimentable fraction; 2) that GH aggregates were not present in glands from thyroidectomized rats, but were in glands from the thyroidectomized rats injected with T4; 3) that GH aggregates were uniquely associated with a heavily granulated somatotroph subpopulation isolated by density gradient centrifugation; and 4) that high mol wt GH forms were released from the dense somatotrophs in culture, since treatment of the culture medium with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. Taken together, the results show that high mol wt GH aggregates are contained in secretory granules of certain somatotrophs and are also released in aggregate form from these cells in vitro.

  13. Simulations of kinetically irreversible protein aggregate structure.

    PubMed Central

    Patro, S Y; Przybycien, T M

    1994-01-01

    We have simulated the structure of kinetically irreversible protein aggregates in two-dimensional space using a lattice-based Monte-Carlo routine. Our model specifically accounts for the intermolecular interactions between hydrophobic and hydrophilic protein surfaces and a polar solvent. The simulations provide information about the aggregate density, the types of inter-monomer contacts and solvent content within the aggregates, the type and extent of solvent exposed perimeter, and the short- and long-range order all as a function of (i) the extent of monomer hydrophobic surface area and its distribution on the model protein surface and (ii) the magnitude of the hydrophobic-hydrophobic contact energy. An increase in the extent of monomer hydrophobic surface area resulted in increased aggregate densities with concomitant decreased system free energies. These effects are accompanied by increases in the number of hydrophobic-hydrophobic contacts and decreases in the solvent-exposed hydrophobic surface area of the aggregates. Grouping monomer hydrophobic surfaces in a single contiguous stretch resulted in lower aggregate densities and lower short range order. More favorable hydrophobic-hydrophobic contact energies produced structures with higher densities but the number of unfavorable protein-protein contacts was also observed to increase; greater configurational entropy produced the opposite effect. Properties predicted by our model are in good qualitative agreement with available experimental observations. Images FIGURE 6 FIGURE 13 PMID:8061184

  14. Modeling transport and aggregation of volcanic ash particles

    NASA Astrophysics Data System (ADS)

    Costa, Antonio; Folch, Arnau; Macedonio, Giovanni; Durant, Adam

    2010-05-01

    A complete description of ash aggregation processes in volcanic clouds is an very arduous task and the full coupling of ash transport and ash aggregation models is still computationally prohibitive. A large fraction of fine ash injected in the atmosphere during explosive eruptions aggregate because of complex interactions of surface liquid layers, electrostatic forces, and differences in settling velocities. The formation of aggregates of size and density different from those of the primary particles dramatically changes the sedimentation dynamics and results in lower atmospheric residence times of ash particles and in the formation of secondary maxima of tephra deposit. Volcanic ash transport models should include a full aggregation model accounting for all particle class interaction. However this approach would require prohibitive computational times. Here we present a simplified model for wet aggregation that accounts for both atmospheric and volcanic water transport. The aggregation model assumes a fractal relationship for the number of primary particles in aggregates, average efficiencies factors, and collision frequency functions accounting for Brownian motion, laminar and turbulent fluid shear, and differential settling velocity. We implemented the aggregation model in the WRF+FALL3D coupled modelling system and applied it to different eruptions where aggregation has been recognized to play an important role, such as the August and September 1992 Crater Peak eruptions and the 1980 Mt St Helens eruption. Moreover, understanding aggregation processes in volcanic clouds will contribute to mitigate the risks related with volcanic ash transport and sedimentation.

  15. Aggregates, broccoli and cauliflower

    NASA Astrophysics Data System (ADS)

    Grey, Francois; Kjems, Jørgen K.

    1989-09-01

    Naturally grown structures with fractal characters like broccoli and cauliflower are discussed and compared with DLA-type aggregates. It is suggested that the branching density can be used to characterize the growth process and an experimental method to determine this parameter is proposed.

  16. Nanostructuring with chirality: binaphthyl-based synthons for the production of functional oriented nanomaterials

    NASA Astrophysics Data System (ADS)

    Caricato, Marco; Sharma, Arvind K.; Coluccini, Carmine; Pasini, Dario

    2014-06-01

    Chirality is a powerful tool for the generation of order, directionality, and, as such, of function, in assembled nanoscale chemical devices. Axially chiral binaphthyls have been widely used in organic synthesis; the stability of the enantiomers enables their use as robust chirality inducers and catalysts in asymmetric reactions, and they are nowadays industrially applied in a variety of organic transformations. Applications of these compounds in the field of nanosciences are more recent, and not yet fully explored. The integration of such a robust class of chiral compounds, capable of efficient transfer of stereochemical information, into functional aggregates and nanoarchitectures is of great current interest. We will discuss preeminent examples of applications of these synthons in several fields of nanoscience, such as reticular chemistry, non-linear optical materials and imaging, and liquid crystals.

  17. Aggregation of AcMNPV LEF-10 and Its Impact on Viral Late Gene Expression

    PubMed Central

    Xu, Xiaodong; Zhou, Xinyu; Nan, Hao; Zhao, Yu; Bai, Yu; Ou, Yanmei; Chen, Hongying

    2016-01-01

    The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) late expression factor gene lef-10 has been identified to be required for viral late gene expression by transient expression assay. Our previous work has shown that the gene product LEF-10 can form very stable high-molecular-weight complexes, but the structure and function of the protein remain unknown. In this study, we demonstrated that LEF-10 was essential for the replication of AcMNPV, and its truncated fragment containing amino acid residues 1 to 48 were sufficient to support the virus survival. Our data also suggested that the LEF-10 could spontaneously aggregate to form punctate spots in virus infected Sf9 cells at low frequency, and the aggregation of the protein could be induced by LEF-10 over-expression. When the protein aggregated to form punctate spots, soluble LEF-10 proteins were depleted and this could result in the down-regulation of viral late gene expression. PMID:27152613

  18. The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

    USGS Publications Warehouse

    Langer, W.H.

    2011-01-01

    An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

  19. Bacterial cinnamoyl esterase activity screening for the production of a novel functional food product.

    PubMed

    Guglielmetti, Simone; De Noni, Ivano; Caracciolo, Federica; Molinari, Francesco; Parini, Carlo; Mora, Diego

    2008-02-01

    Lactobacillus helveticus MIMLh5 was selected for its strong cinnamoyl esterase activity on chlorogenic acid and employed for the preparation of a food product containing a high concentration of free caffeic acid. The novel food product was demonstrated to display high total antioxidant power and potential probiotic properties.

  20. Functional muscle synergies constrain force production during postural tasks.

    PubMed

    McKay, J Lucas; Ting, Lena H

    2008-01-01

    We recently demonstrated that a set of five functional muscle synergies were sufficient to characterize both hindlimb muscle activity and active forces during automatic postural responses in cats standing at multiple postural configurations. This characterization depended critically upon the assumption that the endpoint force vector (synergy force vector) produced by the activation of each muscle synergy rotated with the limb axis as the hindlimb posture varied in the sagittal plane. Here, we used a detailed, 3D static model of the hindlimb to confirm that this assumption is biomechanically plausible: as we varied the model posture, simulated synergy force vectors rotated monotonically with the limb axis in the parasagittal plane (r2=0.94+/-0.08). We then tested whether a neural strategy of using these five functional muscle synergies provides the same force-generating capability as controlling each of the 31 muscles individually. We compared feasible force sets (FFSs) from the model with and without a muscle synergy organization. FFS volumes were significantly reduced with the muscle synergy organization (F=1556.01, p<0.01), and as posture varied, the synergy-limited FFSs changed in shape, consistent with changes in experimentally measured active forces. In contrast, nominal FFS shapes were invariant with posture, reinforcing prior findings that postural forces cannot be predicted by hindlimb biomechanics alone. We propose that an internal model for postural force generation may coordinate functional muscle synergies that are invariant in intrinsic limb coordinates, and this reduced-dimension control scheme reduces the set of forces available for postural control.

  1. An improvement of a beam search method for warehouse storage allocation planning problems minimizing the number of operations and the aggregated number of products for each customer

    NASA Astrophysics Data System (ADS)

    Nishi, Tatsushi; Yamamoto, Shinichiro; Konishi, Masami

    The storage allocation planning problem in warehouse management is to determine the allocation of products to the storage space and intermediate operations for retrieving products so as to minimize the number of operations, and maximize the collected number of products for each customer when the sequence of requests for inlet and retrieval operations are given. In this paper, we propose an efficient beam search method for generating a near optimal solution with a reasonable computation time. A heuristic procedure is also proposed in order to reduce a search space in the beam search method by using the information of subsequent inlet and retrieving requests. The validity of the proposed method is confirmed by comparing the results with the optimal solution derived by solving an MILP problem. The effectiveness of the proposed method is demonstrated by solving an actual large-sized problem consisting of more than 3000 operations.

  2. Production, isolation, purification, and functional characterization of methanobactins.

    PubMed

    Graham, David W; Kim, Hyung J

    2011-01-01

    Aerobic methane-oxidizing bacteria (methanotrophs) have a high conditional need for copper because almost all known species express a copper-containing particulate methane monooxygenase for catalyzing the conversion of methane to methanol. This demands a copper homeostatic system that must both supply and satisfy adequate copper for elevated needs while also shielding the cells from copper toxicity. After considerable effort, it was discovered that some methanotrophs produce small peptidic molecules, called methanobactins, which bind copper, mediate copper transport into the cell, and reduce copper toxicity. Unfortunately, isolating, purifying, and proving the functionality of these molecules has been challenging. In fact, until very recently, only one complete structure had been reported for methanobactins. As such, there is a desperate need for more studies seeking such molecules. The purpose of this chapter is to describe methods used to isolate and purify the original methanobactin with a published complete structure, which is made by Methylosinus trichosporium OB3b. Methods are also included for assessing the function of such molecules under pseudonatural conditions such as growth on mineral copper sources. Special emphasis is placed on verifying that isolated molecules are "true" methanobactins, because recent work has shown that methanotrophs produce other small molecules that also bind metals in solution.

  3. Performance of the dot product function in radiative transfer code SORD

    NASA Astrophysics Data System (ADS)

    Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Aliaksandr; Holben, Brent

    2016-10-01

    The successive orders of scattering radiative transfer (RT) codes frequently call the scalar (dot) product function. In this paper, we study performance of some implementations of the dot product in the RT code SORD using 50 scenarios for light scattering in the atmosphere-surface system. In the dot product function, we use the unrolled loops technique with different unrolling factor. We also considered the intrinsic Fortran functions. We show results for two machines: ifort compiler under Windows, and pgf90 under Linux. Intrinsic DOT_PRODUCT function showed best performance for the ifort. For the pgf90, the dot product implemented with unrolling factor 4 was the fastest. The RT code SORD together with the interface that runs all the mentioned tests are publicly available from ftp://maiac.gsfc.nasa.gov/pub/skorkin/SORD_IP_16B (current release) or by email request from the corresponding (first) author.

  4. Production of functional probiotic, prebiotic, and synbiotic ice creams.

    PubMed

    Di Criscio, T; Fratianni, A; Mignogna, R; Cinquanta, L; Coppola, R; Sorrentino, E; Panfili, G

    2010-10-01

    In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.

  5. Impact of virus aggregation on inactivation by peracetic acid and implications for other disinfectants.

    PubMed

    Mattle, Michael J; Crouzy, Benoit; Brennecke, Moritz; Wigginton, Krista R; Perona, Paolo; Kohn, Tamar

    2011-09-15

    Viruses in wastewater and natural environments are often present as aggregates. The disinfectant dose required for their inactivation, however, is typically determined with dispersed viruses. This study investigates how aggregation affects virus inactivation by chemical disinfectants. Bacteriophage MS2 was aggregated by lowering the solution pH, and aggregates were inactivated by peracetic acid (PAA). Aggregates were redispersed before enumeration to obtain the residual number of individual infectious viruses. In contrast to enumerating whole aggregates, this approach allowed an assessment of disinfection efficiency which remains applicable even if the aggregates disperse in post-treatment environments. Inactivation kinetics were determined as a function of aggregate size (dispersed, 0.55 and 0.90 μm radius) and PAA concentration (5-103 mg/L). Aggregation reduced the apparent inactivation rate constants 2-6 fold. The larger the aggregate and the higher the PAA concentration, the more pronounced the inhibitory effect of aggregation on disinfection. A reaction-diffusion based model was developed to interpret the experimental results, and to predict inactivation rates for additional aggregate sizes and disinfectants. The model showed that the inhibitory effect of aggregation arises from consumption of the disinfectant within the aggregate, but that diffusion of the disinfectant into the aggregates is not a rate-limiting factor. Aggregation therefore has a large inhibitory effect if highly reactive disinfectants are used, whereas inactivation by mild disinfectants is less affected. Our results suggest that mild disinfectants should be used for the treatment of water containing viral aggregates.

  6. The Polymorphic Aggregative Phenotype of Shiga Toxin-Producing Escherichia coli O111 Depends on RpoS and Curli

    PubMed Central

    Diodati, M. E.; Bates, A. H.; Miller, W. G.; Carter, M. Q.; Zhou, Y.

    2015-01-01

    Escherichia coli O111 is an emerging non-O157:H7 serotype of Shiga toxin-producing E. coli (STEC). We previously reported that outbreak and environmental, but not sporadic-case, strains of STEC O111 share a distinct aggregation phenotype (M. E. Diodati, A. H. Bates, M. B. Cooley, S. Walker, R. E. Mandrell, and M. T. Brandl, Foodborne Pathog Dis 12:235−243, 2015, http://dx.doi.org/10.1089/fpd.2014.1887). We show here the natural occurrence of nonaggregative variants in single STEC O111 strains. These variants do not produce curli fimbriae and lack RpoS function but synthesize cellulose. The deletion of csgBAC or rpoS in an aggregative outbreak strain abolished aggregate formation, which was rescued when curli biogenesis or RpoS function, respectively, was restored. Complementation of a nonaggregative variant with RpoS also conferred curli production and aggregation. These observations were supported by Western blotting with an anti-CsgA antibody. Immunomicroscopy revealed that curli were undetectable on the cells of the nonaggregative variant and the RpoS mutant but were present in large quantities in the intercellular matrix of the assemblages formed by aggregative strains. Sequence analysis of rpoS in the aggregative strain and its variant showed a single substitution of threonine for asparagine at amino acid 124. Our results indicate that the multicellular behavior of STEC O111 is RpoS dependent via positive regulation of curli production. Aggregation may confer a fitness advantage in O111 outbreak strains under stressful conditions in hydrodynamic environments along the food production chain and in the host, while the occurrence of nonaggregative variants may allow the cell population to adapt to conditions benefiting a planktonic lifestyle. PMID:26712542

  7. Bi-modal hetero-aggregation rate response to particle dosage.

    PubMed

    Olsen, Aaron; Franks, George; Biggs, Simon; Jameson, Graeme J

    2005-11-22

    The rate of flocculation of cationic polystyrene latex (PSL) particles by smaller, anionic PSL particles has been measured using a low-angle static light scattering technique. The rate of aggregate growth has been investigated as a function of particle size ratio and relative concentration of each particle species (for a constant dose of cationic particles). Contrary to many previous reports, two peaks in the flocculation rate were observed as a function of dose. It is speculated that the peak observed at the lower particle concentration coincides with the dose yielding maximum constant collision efficiency in the steady-state regime, a condition which is attained only after complete adsorption of the smaller particles onto the larger particle species. The peak at the higher particle concentration is believed to be related to the maximum collision rate constant upon reaching the steady-state regime, the value of which corresponds to maximum degree of aggregation and therefore the maximum mean collision efficiency prior to reaching this condition. From classical collision kinetics, the rate of aggregate growth may be represented as being proportional to the product of the collision rate constant and collision efficiency at any given time. Given then that the maximum value of these two variables coincides with different particle concentrations, the product of the response of each to particle dosage can in some cases yield a net bi-modal aggregation rate response to particle dosage.

  8. Production and biological function of volatile esters in Saccharomyces cerevisiae.

    PubMed

    Saerens, Sofie M G; Delvaux, Freddy R; Verstrepen, Kevin J; Thevelein, Johan M

    2010-03-01

    The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important groups of esters: the acetate esters and the medium-chain fatty acid (MCFA) ethyl esters. For acetate ester synthesis, the genes involved have already been cloned and characterized. Also the biochemical pathways and the regulation of acetate ester synthesis are well defined. With respect to the molecular basis of MCFA ethyl ester synthesis, however, significant progress has only recently been made. Next to the characterization of the biochemical pathways and regulation of ester synthesis, a new and more important question arises: what is the advantage for yeast to produce these esters? Several hypotheses have been proposed in the past, but none was satisfactorily. This paper reviews the current hypotheses of ester synthesis in yeast in relation to the complex regulation of the alcohol acetyl transferases and the different factors that allow ester formation to be controlled during fermentation.

  9. Electromagnetic wave emitting products and "Kikoh" potentiate human leukocyte functions.

    PubMed

    Niwa, Y; Iizawa, O; Ishimoto, K; Jiang, X; Kanoh, T

    1993-09-01

    Tourmaline (electric stone, a type of granite stone), common granite stone, ceramic disks, hot spring water and human palmar energy (called "Kikoh" in Japan and China), all which emit electromagnetic radiation in the far infrared region (wavelength 4-14 microns). These materials were thus examined for effects on human leukocyte activity and on lipid peroxidation of unsaturated fatty acids. It was revealed that these materials significantly increased intracellular calcium ion concentration, phagocytosis, and generation of reactive oxygen species in neutrophils, and the blastogenetic response of lymphocytes to mitogens. Chemotactic activity by neutrophils was also enhanced by exposure to tourmaline and the palm of "Kikohshi" i.e., a person who heals professionally by the laying on of hands. Despite the increase in reactive oxygen species generated by neutrophils, lipid peroxidation from unsaturated fatty acid was markedly inhibited by these four materials. The results suggest that materials emitting electromagnetic radiation in the far infrared range, which are widely used in Japan for cosmetic, therapeutic, and preservative purposes, appear capable of potentiating leukocyte functions without promoting oxidative injury.

  10. Electromagnetic wave emitting products and ``Kikoh'' potentiate human leukocyte functions

    NASA Astrophysics Data System (ADS)

    Niwa, Yukie; Iizawa, Osamu; Ishimoto, Koichi; Jiang, Xiaoxia; Kanoh, Tadashi

    1993-09-01

    Tourmaline (electric stone, a type of granite stone), common granite stone, ceramic disks, hot spring water and human palmar energy (called “Kikoh” in Japan and China), all which emit electromagnetic radiation in the far infrared region (wavelength 4 14 µm). These materials were thus examined for effects on human leukocyte activity and on lipid peroxidation of unsaturated fatty acids. It was revealed that these materials significantly increased intracellular calcium ion concentration, phagocytosis, and generation of reactive oxygen species in neutrophils, and the blastogenetic response of lymphocytes to mitogens. Chemotactic activity by neutrophils was also enhanced by exposure to tourmaline and the palm of “Kikohshi” i.e., a person who heals professionally by the laying on of hands. Despite the increase in reactive oxygen species generated by neutrophils, lipid peroxidation from unsaturated fatty acid was markedly inhibited by these four materials. The results suggest that materials emitting electromagnetic radiation in the far infrared range, which are widely used in Japan for cosmetic, therapeutic, and preservative purposes, appear capable of potentiating leukocyte functions without promoting oxidative injury.

  11. Production and biological function of volatile esters in Saccharomyces cerevisiae

    PubMed Central

    Saerens, Sofie M. G.; Delvaux, Freddy R.; Verstrepen, Kevin J.; Thevelein, Johan M.

    2010-01-01

    Summary The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important groups of esters: the acetate esters and the medium‐chain fatty acid (MCFA) ethyl esters. For acetate ester synthesis, the genes involved have already been cloned and characterized. Also the biochemical pathways and the regulation of acetate ester synthesis are well defined. With respect to the molecular basis of MCFA ethyl ester synthesis, however, significant progress has only recently been made. Next to the characterization of the biochemical pathways and regulation of ester synthesis, a new and more important question arises: what is the advantage for yeast to produce these esters? Several hypotheses have been proposed in the past, but none was satisfactorily. This paper reviews the current hypotheses of ester synthesis in yeast in relation to the complex regulation of the alcohol acetyl transferases and the different factors that allow ester formation to be controlled during fermentation. PMID:21255318

  12. Properties of Concrete with Tire Derived Aggregate Partially Replacing Coarse Aggregates.

    PubMed

    Siringi, Gideon; Abolmaali, Ali; Aswath, Pranesh B

    2015-01-01

    Tire derived aggregate (TDA) has been proposed as a possible lightweight replacement for mineral aggregate in concrete. The role played by the amount of TDA replacing coarse aggregate as well as different treatment and additives in concrete on its properties is examined. Conventional concrete (without TDA) and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, splitting tensile strength based on ASTM C496, modulus of rupture (flexural strength) based on ASTM C78, and bond stress based on ASTM C234. Results indicate that while replacement of coarse aggregates with TDA results in reduction in strength, it may be mitigated with addition of silica fume to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product while utilizing recycled TDA.

  13. Properties of Concrete with Tire Derived Aggregate Partially Replacing Coarse Aggregates

    PubMed Central

    Siringi, Gideon; Abolmaali, Ali; Aswath, Pranesh B.

    2015-01-01

    Tire derived aggregate (TDA) has been proposed as a possible lightweight replacement for mineral aggregate in concrete. The role played by the amount of TDA replacing coarse aggregate as well as different treatment and additives in concrete on its properties is examined. Conventional concrete (without TDA) and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, splitting tensile strength based on ASTM C496, modulus of rupture (flexural strength) based on ASTM C78, and bond stress based on ASTM C234. Results indicate that while replacement of coarse aggregates with TDA results in reduction in strength, it may be mitigated with addition of silica fume to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product while utilizing recycled TDA. PMID:26161440

  14. Tracking protein aggregate interactions

    PubMed Central

    Bartz, Jason C; Nilsson, K Peter R

    2011-01-01

    Amyloid fibrils share a structural motif consisting of highly ordered β-sheets aligned perpendicular to the fibril axis.1, 2 At each fibril end, β-sheets provide a template for recruiting and converting monomers.3 Different amyloid fibrils often co-occur in the same individual, yet whether a protein aggregate aids or inhibits the assembly of a heterologous protein is unclear. In prion disease, diverse prion aggregate structures, known as strains, are thought to be the basis of disparate disease phenotypes in the same species expressing identical prion protein sequences.4–7 Here we explore the interactions reported to occur when two distinct prion strains occur together in the central nervous system. PMID:21597336

  15. Crop kites: Determining crop-water production functions using crop coefficients and sensitivity indices

    NASA Astrophysics Data System (ADS)

    Smilovic, Mikhail; Gleeson, Tom; Adamowski, Jan

    2016-11-01

    The crop-water production function quantitatively evaluates the relationship between seasonal water use and crop yield and is used to evaluate optimal irrigation depth and assess the potential of deficit and supplemental irrigation. A simple and easily applicable methodology to develop crop- and region-specific crop-water production functions using crop coefficients and sensitivity-indices is presented. Previous efforts to describe the crop-water production function have not accounted for the effects of the temporal distribution of water use and trivialize the associated variability in yields by assuming an optimized or arbitrary temporal distribution. The temporal distribution of water use throughout the growing season can significantly influence crop yield, and the ability of farmers to manage both the timing and amount of irrigation water may result in higher yields. We propose crop kites, a tool that explicitly acknowledges crop yield as a function of the temporal distribution of water use to both evaluate the complete space of water use and crop yield relationships, and extract from this space specific crop-water production functions. An example for winter wheat is presented using previously validated crop-specific sensitivity indices. Crop-water production functions are extracted from the crop kite related to specific irrigation schedules and temporal distributions of water use. Crop-water production functions associated with maximizing agricultural production agree with previous efforts characterizing the shape as a diminishing curvilinear function. Crop kites provide the tools for water managers and policy makers to evaluate crop- and region-specific agricultural production as it relates to water management and the associated economics, and to determine appropriate policies for developing and supporting the infrastructure to increase water productivity.

  16. Kinetic studies on the aggregation of Aspergillus niger conidia.

    PubMed

    Grimm, L H; Kelly, S; Hengstler, J; Göbel, A; Krull, R; Hempel, D C

    2004-07-20

    Morphology has a crucial effect on productivity and the supply of substrate for cultures of filamentous fungi. However, cultivation parameters leading to the desired morphology are often chosen empirically as the mechanisms governing the processes involved are usually unknown. For coagulating microorganisms like Aspergillus niger the morphological development is considered to start with the aggregation of conidia right after inoculation. To elucidate the mechanism of this process, kinetic studies were carried out using an in-line particle size analyzer. Based on the data obtained from these experiments a model for conidial aggregation is proposed in this article. It consists of two separate aggregation steps. The first one takes place immediately after inoculation, but only leads to a small decrease of total particle concentration. Most suspended conidia aggregate after a second aggregation step triggered by germination and hyphal growth. Aggregation velocity of this second phase is linearly dependent on the particle growth rate.

  17. Determination of the dynamic elastic constants of recycled aggregate concrete

    NASA Astrophysics Data System (ADS)

    Tsoumani, A. A.; Barkoula, N.-M.; Matikas, T. E.

    2015-03-01

    Nowadays, construction and demolition waste constitutes a major portion of the total solid waste production in the world. Due to both environmental and economical reasons, an increasing interest concerning the use of recycled aggregate to replace aggregate from natural sources is generated. This paper presents an investigation on the properties of recycled aggregate concrete. Concrete mixes are prepared using recycled aggregates at a substitution level between 0 and 100% of the total coarse aggregate. The influence of this replacement on strengthened concrete's properties is being investigated. The properties estimated are: density and dynamic modulus of elasticity at the age of both 7 and 28 days. Also, flexural strength of 28 days specimens is estimated. The determination of the dynamic elastic modulus was made using the ultrasonic pulse velocity method. The results reveal that the existence of recycled aggregates affects the properties of concrete negatively; however, in low levels of substitution the influence of using recycled aggregates is almost negligible. Concluding, the controlled use of recycled aggregates in concrete production may help solve a vital environmental issue apart from being a solution to the problem of inadequate concrete aggregates.

  18. Monitoring Insulin Aggregation via Capillary Electrophoresis

    PubMed Central

    Pryor, Elizabeth; Kotarek, Joseph A.; Moss, Melissa A.; Hestekin, Christa N.

    2011-01-01

    Early stages of insulin aggregation, which involve the transient formation of oligomeric aggregates, are an important aspect in the progression of Type II diabetes and in the quality control of pharmaceutical insulin production. This study is the first to utilize capillary electrophoresis (CE) with ultraviolet (UV) detection to monitor insulin oligomer formation at pH 8.0 and physiological ionic strength. The lag time to formation of the first detected species in the aggregation process was evaluated by UV-CE and thioflavin T (ThT) binding for salt concentrations from 100 mM to 250 mM. UV-CE had a significantly shorter (5–8 h) lag time than ThT binding (15–19 h). In addition, the lag time to detection of the first aggregated species via UV-CE was unaffected by salt concentration, while a trend toward an increased lag time with increased salt concentration was observed with ThT binding. This result indicates that solution ionic strength impacts early stages of aggregation and β-sheet aggregate formation differently. To observe whether CE may be applied for the analysis of biological samples containing low insulin concentrations, the limit of detection using UV and laser induced fluorescence (LIF) detection modes was determined. The limit of detection using LIF-CE, 48.4 pM, was lower than the physiological insulin concentration, verifying the utility of this technique for monitoring biological samples. LIF-CE was subsequently used to analyze the time course for fluorescein isothiocyanate (FITC)-labeled insulin oligomer formation. This study is the first to report that the FITC label prevented incorporation of insulin into oligomers, cautioning against the use of this fluorescent label as a tag for following early stages of insulin aggregation. PMID:22272138

  19. Zooplankton Aggregations Near Sills

    DTIC Science & Technology

    2003-09-30

    frequency echo-sounder system. This data were supplemented with multi-net (BIONESS) trawls, bongo nets, and otter trawls (operated by D. Mackas and group...side. The general composition of the zooplankton aggregations can be deduced from the relative levels of the three echo-sounder frequencies; krill ...Nov. 20th, 2002. Krill layer is evident at 66 – 90 m, coincident with BIONESS trawl through the region. 3 Figure 2 shows a comparison between

  20. Modeling of chemical inhibition from amyloid protein aggregation kinetics

    PubMed Central

    2014-01-01

    Backgrounds The process of amyloid proteins aggregation causes several human neuropathologies. In some cases, e.g. fibrillar deposits of insulin, the problems are generated in the processes of production and purification of protein and in the pump devices or injectable preparations for diabetics. Experimental kinetics and adequate modelling of chemical inhibition from amyloid aggregation are of practical importance in order to study the viable processing, formulation and storage as well as to predict and optimize the best conditions to reduce the effect of protein nucleation. Results In this manuscript, experimental data of insulin, Aβ42 amyloid protein and apomyoglobin fibrillation from recent bibliography were selected to evaluate the capability of a bivariate sigmoid equation to model them. The mathematical functions (logistic combined with Weibull equation) were used in reparameterized form and the effect of inhibitor concentrations on kinetic parameters from logistic equation were perfectly defined and explained. The surfaces of data were accurately described by proposed model and the presented analysis characterized the inhibitory influence on the protein aggregation by several chemicals. Discrimination between true and apparent inhibitors was also confirmed by the bivariate equation. EGCG for insulin (working at pH = 7.4/T = 37°C) and taiwaniaflavone for Aβ42 were the compounds studied that shown the greatest inhibition capacity. Conclusions An accurate, simple and effective model to investigate the inhibition of chemicals on amyloid protein aggregation has been developed. The equation could be useful for the clear quantification of inhibitor potential of chemicals and rigorous comparison among them. PMID:24572069

  1. Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product

    PubMed Central

    Crum, Alia J.; Phillips, Damon J.; Goyer, J. Parker; Akinola, Modupe; Higgins, E. Tory

    2016-01-01

    This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, “AquaCharge Energy Water,” falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water. PMID:27875567

  2. Utilitarian Aggregation of Beliefs and Tastes.

    ERIC Educational Resources Information Center

    Gilboa, Itzhak; Samet, Dov; Schmeidler, David

    2004-01-01

    Harsanyi's utilitarianism is extended here to Savage's framework. We formulate a Pareto condition that implies that both society's utility function and its probability measure are linear combinations of those of the individuals. An indiscriminate Pareto condition has been shown to contradict linear aggregation of beliefs and tastes. We argue that…

  3. Aggregation of organic matter by pelagic tunicates

    SciTech Connect

    Pomeroy, L.R.; Deibel, D.

    1980-07-01

    Three genera of pelagic tunicates were fed concentrates of natural seston and an axenic diatom culture. Fresh and up to 4-day-old feces resemble flocculent organic aggregates containing populations of microorganisms, as described from highly productive parts of the ocean, and older feces resemble the nearly sterile flocculent aggregates which are ubiquitous in surface waters. Fresh feces consist of partially digested phytoplankton and other inclusions in an amorphous gelatinous matrix. After 18 to 36 h, a population of large bacteria develops in the matrix and in some of the remains of phytoplankton contained in the feces. From 48 to 96 h, protozoan populations arise which consume the bacteria and sometimes the remains of the phytoplankton in the feces. Thereafter only a sparse population of microorganisms remains, and the particles begin to fragment. Water samples taken in or below dense populations of salps and doliolids contained greater numbers of flocculent aggregates than did samples from adjacent stations.

  4. Diatom-associated bacteria are required for aggregation of Thalassiosira weissflogii

    PubMed Central

    Gärdes, Astrid; Iversen, Morten H; Grossart, Hans-Peter; Passow, Uta; Ullrich, Matthias S

    2011-01-01

    Aggregation of algae, mainly diatoms, is an important process in marine systems leading to the settling of particulate organic carbon predominantly in the form of marine snow. Exudation products of phytoplankton form transparent exopolymer particles (TEP), which acts as the glue for particle aggregation. Heterotrophic bacteria interacting with phytoplankton may influence TEP formation and phytoplankton aggregation. This bacterial impact has not been explored in detail. We hypothesized that bacteria attaching to Thalassiosira weissflogii might interact in a yet-to-be determined manner, which could impact TEP formation and aggregate abundance. The role of individual T. weissflogii-attaching and free-living new bacterial isolates for TEP production and diatom aggregation was investigated in vitro. T. weissflogii did not aggregate in axenic culture, and striking differences in aggregation dynamics and TEP abundance were observed when diatom cultures were inoculated with either diatom-attaching or free-living bacteria. The data indicated that free-living bacteria might not influence aggregation whereas bacteria attaching to diatom cells may increase aggregate formation. Interestingly, photosynthetically inactivated T. weissflogii cells did not aggregate regardless of the presence of bacteria. Comparison of aggregate formation, TEP production, aggregate sinking velocity and solid hydrated density revealed remarkable differences. Both, photosynthetically active T. weissflogii and specific diatom-attaching bacteria were required for aggregation. It was concluded that interactions between heterotrophic bacteria and diatoms increased aggregate formation and particle sinking and thus may enhance the efficiency of the biological pump. PMID:20827289

  5. Extended polyglutamine tracts cause aggregation and structural perturbation of an adjacent beta barrel protein.

    PubMed

    Ignatova, Zoya; Gierasch, Lila M

    2006-05-05

    Formation of fibrillar intranuclear inclusions and related neuropathologies of the CAG-repeat disorders are linked to the expansion of a polyglutamine tract. Despite considerable effort, the etiology of these devastating diseases remains unclear. Although polypeptides with glutamine tracts recapitulate many of the observed characteristics of the gene products with CAG repeats, such as in vitro and in vivo aggregation and toxicity in model organisms, extended polyglutamine segments have also been reported to structurally perturb proteins into which they are inserted. Additionally, the sequence context of a polyglutamine tract has recently been shown to modulate its propensity to aggregate. These findings raise the possibility that indirect influences of the repeat tract on adjacent protein domains are contributory to pathologies. Destabilization of an adjacent domain may lead to loss of function, as well as favoring non-native structures in the neighboring domain causing them to be prone to intermolecular association and consequent aggregation. To explore these phenomena, we have used chimeras of a well studied globular protein and exon 1 of huntingtin. We find that expansion of the polyglutamine segment beyond the pathological threshold (>35 glutamines) results in structural perturbation of the neighboring protein whether the huntingtin exon is N- or C-terminal. Elongation of the polyglutamine region also substantially increases the propensity of the chimera to aggregate, both in vitro and in vivo, and in vitro aggregation kinetics of a chimera with a 53-glutamine repeat follow a nucleation polymerization mechanism with a monomeric nucleus.

  6. 78 FR 73563 - Certain Electronic Devices Having Placeshifting or Display Replication Functionality and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Electronic Devices Having Placeshifting or Display Replication Functionality and Products... limited exclusion order prohibiting the unlicensed entry of electronic devices having placeshifting...

  7. Using a Polytope to Estimate Efficient Production Functions of Joint Product Processes.

    ERIC Educational Resources Information Center

    Simpson, William A.

    In the last decade, a modeling technique has been developed to handle complex input/output analyses where outputs involve joint products and there are no known mathematical relationships linking the outputs or inputs. The technique uses the geometrical concept of a six-dimensional shape called a polytope to analyze the efficiency of each…

  8. Economic values of production and functional traits, including residual feed intake, in Finnish milk production.

    PubMed

    Hietala, P; Wolfová, M; Wolf, J; Kantanen, J; Juga, J

    2014-02-01

    Improving the feed efficiency of dairy cattle has a substantial effect on the economic efficiency and on the reduction of harmful environmental effects of dairy production through lower feeding costs and emissions from dairy farming. To assess the economic importance of feed efficiency in the breeding goal for dairy cattle, the economic values for the current breeding goal traits and the additional feed efficiency traits for Finnish Ayrshire cattle under production circumstances in 2011 were determined. The derivation of economic values was based on a bioeconomic model in which the profit of the production system was calculated, using the generated steady state herd structure. Considering beef production from dairy farms, 2 marketing strategies for surplus calves were investigated: (A) surplus calves were sold at a young age and (B) surplus calves were fattened on dairy farms. Both marketing strategies were unprofitable when subsidies were not included in the revenues. When subsidies were taken into account, a positive profitability was observed in both marketing strategies. The marginal economic values for residual feed intake (RFI) of breeding heifers and cows were -25.5 and -55.8 €/kg of dry matter per day per cow and year, respectively. The marginal economic value for RFI of animals in fattening was -29.5 €/kg of dry matter per day per cow and year. To compare the economic importance among traits, the standardized economic weight of each trait was calculated as the product of the marginal economic value and the genetic standard deviation; the standardized economic weight expressed as a percentage of the sum of all standardized economic weights was called relative economic weight. When not accounting for subsidies, the highest relative economic weight was found for 305-d milk yield (34% in strategy A and 29% in strategy B), which was followed by protein percentage (13% in strategy A and 11% in strategy B). The third most important traits were calving

  9. Comparative environmental assessment of natural and recycled aggregate concrete.

    PubMed

    Marinković, S; Radonjanin, V; Malešev, M; Ignjatović, I

    2010-11-01

    Constant and rapid increase in construction and demolition (C&D) waste generation and consumption of natural aggregate for concrete production became one of the biggest environmental problems in the construction industry. Recycling of C&D waste represents one way to convert a waste product into a resource but the environment benefits through energy consumption, emissions and fallouts reductions are not certain. The main purpose of this study is to determine the potentials of recycled aggregate concrete (concrete made with recycled concrete aggregate) for structural applications and to compare the environmental impact of the production of two types of ready-mixed concrete: natural aggregate concrete (NAC) made entirely with river aggregate and recycled aggregate concrete (RAC) made with natural fine and recycled coarse aggregate. Based on the analysis of up-to-date experimental evidence, including own tests results, it is concluded that utilization of RAC for low-to-middle strength structural concrete and non-aggressive exposure conditions is technically feasible. The Life Cycle Assessment (LCA) is performed for raw material extraction and material production part of the concrete life cycle including transport. Assessment is based on local LCI data and on typical conditions in Serbia. Results of this specific case study show that impacts of aggregate and cement production phases are slightly larger for RAC than for NAC but the total environmental impacts depend on the natural and recycled aggregates transport distances and on transport types. Limit natural aggregate transport distances above which the environmental impacts of RAC can be equal or even lower than the impacts of NAC are calculated for the specific case study.

  10. Formation of multilayer aggregates of mammalian cells by dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Sebastian, Anil; Buckle, Anne-Marie; Markx, Gerard H.

    2006-09-01

    The formation of aggregates of mammalian cells at interdigitated oppositely castellated electrodes by positive dielectrophoresis was investigated. It is shown that, by using a constant small flow of fresh sorbitol iso-osmotic buffer through the chamber to remove ions leaking from the cells, a high positive DEP force can be maintained throughout the formation of the aggregates. Flow-rate dependent optima were found in the aggregate height as a function of the electrode size. It is shown that at low flow rates the creation of aggregates of mammalian cells with heights over 150 µm is feasible using relatively low voltages (20 Vpk-pk, 1 MHz). The formation of layered aggregates of two specialized cell types—stromal cells and Jurkat T lymphocytes—is demonstrated. The work confirms that dielectrophoresis can be reliably used for the formation of aggregates with three-dimensional architectures, which could be used as artificial microniches for the study of interactions between cells.

  11. Aggregation of theta-polymers in spherical confinement.

    PubMed

    Zierenberg, Johannes; Mueller, Marco; Schierz, Philipp; Marenz, Martin; Janke, Wolfhard

    2014-09-21

    We investigate the aggregation transition of theta polymers in spherical confinement with multicanonical simulations. This allows for a systematic study of the effect of density on the aggregation transition temperature for up to 24 monodisperse polymers. Our results for solutions in the dilute regime show that polymers can be considered isolated for all temperatures larger than the aggregation temperature, which is shown to be a function of the density. The resulting competition between single-polymer collapse and aggregation yields the lower temperature bound of the isolated chain approximation. We provide entropic and energetic arguments to describe the density dependence and finite-size effects of the aggregation transition for monodisperse solutions in finite systems. This allows us to estimate the aggregation transition temperature of dilute systems in a spherical cavity, using a few simulations of small, sufficiently dilute polymer systems.

  12. Gut bacteria mediate aggregation in the German cockroach

    PubMed Central

    Wada-Katsumata, Ayako; Zurek, Ludek; Nalyanya, Godfrey; Roelofs, Wendell L.; Zhang, Aijun; Schal, Coby

    2015-01-01

    Aggregation of the German cockroach, Blattella germanica, is regulated by fecal aggregation agents (pheromones), including volatile carboxylic acids (VCAs). We demonstrate that the gut microbial community contributes to production of these semiochemicals. Chemical analysis of the fecal extract of B. germanica revealed 40 VCAs. Feces from axenic cockroaches (no microorganisms in the alimentary tract) lacked 12 major fecal VCAs, and 24 of the remaining compounds were represented at extremely low amounts. Olfactory and aggregation bioassays demonstrated that nymphs strongly preferred the extract of control feces over the fecal extract of axenic cockroaches. Additionally, nymphs preferred a synthetic blend of 6 fecal VCAs over a solvent control or a previously identified VCA blend. To test whether gut bacteria contribute to the production of fecal aggregation agents, fecal aerobic bacteria were cultured, isolated, and identified. Inoculation of axenic cockroaches with individual bacterial taxa significantly rescued the aggregation response to the fecal extract, and inoculation with a mix of six bacterial isolates was more effective than with single isolates. The results indicate that the commensal gut microbiota contributes to production of VCAs that act as fecal aggregation agents and that cockroaches discriminate among the complex odors that emanate from a diverse microbial community. Our results highlight the pivotal role of gut bacteria in mediating insect–insect communication. Moreover, because the gut microbial community reflects the local environment, local plasticity in fecal aggregation pheromones enables colony-specific odors and fidelity to persistent aggregation sites. PMID:26644557

  13. Gut bacteria mediate aggregation in the German cockroach.

    PubMed

    Wada-Katsumata, Ayako; Zurek, Ludek; Nalyanya, Godfrey; Roelofs, Wendell L; Zhang, Aijun; Schal, Coby

    2015-12-22

    Aggregation of the German cockroach, Blattella germanica, is regulated by fecal aggregation agents (pheromones), including volatile carboxylic acids (VCAs). We demonstrate that the gut microbial community contributes to production of these semiochemicals. Chemical analysis of the fecal extract of B. germanica revealed 40 VCAs. Feces from axenic cockroaches (no microorganisms in the alimentary tract) lacked 12 major fecal VCAs, and 24 of the remaining compounds were represented at extremely low amounts. Olfactory and aggregation bioassays demonstrated that nymphs strongly preferred the extract of control feces over the fecal extract of axenic cockroaches. Additionally, nymphs preferred a synthetic blend of 6 fecal VCAs over a solvent control or a previously identified VCA blend. To test whether gut bacteria contribute to the production of fecal aggregation agents, fecal aerobic bacteria were cultured, isolated, and identified. Inoculation of axenic cockroaches with individual bacterial taxa significantly rescued the aggregation response to the fecal extract, and inoculation with a mix of six bacterial isolates was more effective than with single isolates. The results indicate that the commensal gut microbiota contributes to production of VCAs that act as fecal aggregation agents and that cockroaches discriminate among the complex odors that emanate from a diverse microbial community. Our results highlight the pivotal role of gut bacteria in mediating insect-insect communication. Moreover, because the gut microbial community reflects the local environment, local plasticity in fecal aggregation pheromones enables colony-specific odors and fidelity to persistent aggregation sites.

  14. Collisional Aggregation Due to Turbulence

    NASA Astrophysics Data System (ADS)

    Pumir, Alain; Wilkinson, Michael

    2016-03-01

    Collisions between particles suspended in a fluid play an important role in many physical processes. As an example, collisions of microscopic water droplets in clouds are a necessary step in the production of macroscopic raindrops. Collisions of dust grains are also conjectured to be important for planet formation in the gas surrounding young stars and to play a role in the dynamics of sand storms. In these processes, collisions are favored by fast turbulent motions. Here we review recent advances in the understanding of collisional aggregation due to turbulence. We discuss the role of fractal clustering of particles and caustic singularities of their velocities. We also discuss limitations of the Smoluchowski equation for modeling such processes. These advances lead to a semiquantitative understanding on the influence of turbulence on collision rates and point to deficiencies in the current understanding of rainfall and planet formation.

  15. Second language experience modulates functional brain network for the native language production in bimodal bilinguals.

    PubMed

    Zou, Lijuan; Abutalebi, Jubin; Zinszer, Benjamin; Yan, Xin; Shu, Hua; Peng, Danling; Ding, Guosheng

    2012-09-01

    The functional brain network of a bilingual's first language (L1) plays a crucial role in shaping that of his or her second language (L2). However, it is less clear how L2 acquisition changes the functional network of L1 processing in bilinguals. In this study, we demonstrate that in bimodal (Chinese spoken-sign) bilinguals, the functional network supporting L1 production (spoken language) has been reorganized to accommodate the network underlying L2 production (sign language). Using functional magnetic resonance imaging (fMRI) and a picture naming task, we find greater recruitment of the right supramarginal gyrus (RSMG), the right temporal gyrus (RSTG), and the right superior occipital gyrus (RSOG) for bilingual speakers versus monolingual speakers during L1 production. In addition, our second experiment reveals that these regions reflect either automatic activation of L2 (RSOG) or extra cognitive coordination (RSMG and RSTG) between both languages during L1 production. The functional connectivity between these regions, as well as between other regions that are L1- or L2-specific, is enhanced during L1 production in bimodal bilinguals as compared to their monolingual peers. These findings suggest that L1 production in bimodal bilinguals involves an interaction between L1 and L2, supporting the claim that learning a second language does, in fact, change the functional brain network of the first language.

  16. The Importance of Context in Development and Application of Ecosystem Services Production Functions

    EPA Science Inventory

    The task of estimating ecosystem service production and delivery deserves special attention. When approached as a function of land cover at any given time, context driven facets of ecosystem service production, delivery, and resulting effects on human well-being can be overlooke...

  17. Interference between Coulombic and CT-mediated couplings in molecular aggregates: H- to J-aggregate transformation in perylene-based π-stacks

    SciTech Connect

    Hestand, Nicholas J.; Spano, Frank C.

    2015-12-28

    The spectroscopic differences between J and H-aggregates are traditionally attributed to the spatial dependence of the Coulombic coupling, as originally proposed by Kasha. However, in tightly packed molecular aggregates wave functions on neighboring molecules overlap, leading to an additional charge transfer (CT) mediated exciton coupling with a vastly different spatial dependence. The latter is governed by the nodal patterns of the molecular LUMOs and HOMOs from which the electron (t{sub e}) and hole (t{sub h}) transfer integrals derive. The sign of the CT-mediated coupling depends on the sign of the product t{sub e}t{sub h} and is therefore highly sensitive to small (sub-Angstrom) transverse displacements or slips. Given that Coulombic and CT-mediated couplings exist simultaneously in tightly packed molecular systems, the interference between the two must be considered when defining J and H-aggregates. Generally, such π-stacked aggregates do not abide by the traditional classification scheme of Kasha: for example, even when the Coulomb coupling is strong the presence of a similarly strong but destructively interfering CT-mediated coupling results in “null-aggregates” which spectroscopically resemble uncoupled molecules. Based on a Frenkel/CT Holstein Hamiltonian that takes into account both sources of electronic coupling as well as intramolecular vibrations, vibronic spectral signatures are developed for integrated Frenkel/CT systems in both the perturbative and resonance regimes. In the perturbative regime, the sign of the lowest exciton band curvature, which rigorously defines J and H-aggregation, is directly tracked by the ratio of the first two vibronic peak intensities. Even in the resonance regime, the vibronic ratio remains a useful tool to evaluate the J or H nature of the system. The theory developed is applied to the reversible H to J-aggregate transformations recently observed in several perylene bisimide systems.

  18. Comparisons between Educator Performance Function-Based and Education Production Function-Based Teacher Effect Estimations

    ERIC Educational Resources Information Center

    Ham, Eun Hye

    2014-01-01

    Challenging the current discordance in orientation between student assessment models and teacher/school value-added models, this study aims to present the educator performance function (EPERF)-based teacher effect estimation method which utilizes the nature of student criterion-referenced assessment, to evaluate its feasibility and usefulness by…

  19. Functional properties of plantain, cowpea flours and oat fiber in extruded products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drying effect on functional properties of two plantain and cowpea varieties and suitability of their flour blends in extruded snacks was determined. The functional and rheological behaviors of (plantain: cowpea): 90:10, 80:20, 70:30, 60:40 and 50:50 blends were evaluated. The extrusion product melt ...

  20. From Aggregate Availability to Sustainability in California

    NASA Astrophysics Data System (ADS)

    Testa, S. M.; Parrish, J. G.

    2012-12-01

    California leads the nation in the production of sand and gravel, and ranks second behind Texas in the production of portland cement. Prior to 1960, the California Geological Survey (CGS, formerly the Division of Mines and Geology) and the State Mining and Geology Board (SMGB, formerly State Mining Board) placed an emphasis "in obtaining and providing information of benefit to the State's mineral industry". By the late 1960s, the Division initiated activities in the area of geologic hazards, and also expressed concern over the loss of aggregate resources via urbanization, which were among the state's most valuable mineral resource. Under the California Surface Mining and Reclamation Act of 1975 (SMARA), the State Geologist classifies mineral resources solely on geologic factors, and without regard to existing land use and land ownership. Following classification, the SMGB may consider "designating" such lands should the classified area contain mineral resources of regional or statewide economic significance and that may be needed to meet future demands. In 1979, the classification of aggregate resources in the three-county area of Los Angeles, Orange, and Ventura, was completed, with designation of such resources in Los Angeles County in 1981. Maps and descriptions of the designated mineral lands were placed in the California Public Resources Code and officially transmitted to those county and city governments having permitting authority over the use of those lands. In 1999, the SMGB in concert with CGS implemented the SMARA Regional Synthesis Map series, with the first (and last) of the series covering the Los Angeles Basin. This map was very useful for regional planners and the general citizenry since it provided a broader perspective not readily apparent in the smaller scale Production-Consumption (P-C) regional maps. CGS's statewide Aggregate Availability Map, commonly referred to as Map Sheet 52, was developed in 2002 and updated in 2006. The purpose of Map 52

  1. Swarms: Optimum aggregations of spacecraft

    NASA Technical Reports Server (NTRS)

    Mayer, H. L.

    1980-01-01

    Swarms are aggregations of spacecraft or elements of a space system which are cooperative in function, but physically isolated or only loosely connected. For some missions the swarm configuration may be optimum compared to a group of completely independent spacecraft or a complex rigidly integrated spacecraft or space platform. General features of swarms are induced by considering an ensemble of 26 swarms, examples ranging from Earth centered swarms for commercial application to swarms for exploring minor planets. A concept for a low altitude swarm as a substitute for a space platform is proposed and a preliminary design studied. The salient design feature is the web of tethers holding the 30 km swarm in a rigid two dimensional array in the orbital plane. A mathematical discussion and tutorial in tether technology and in some aspects of the distribution of services (mass, energy, and information to swarm elements) are included.

  2. Structure of Viral Aggregates

    NASA Astrophysics Data System (ADS)

    Barr, Stephen; Luijten, Erik

    2010-03-01

    The aggregation of virus particles is a particular form of colloidal self-assembly, since viruses of a give type are monodisperse and have identical, anisotropic surface charge distributions. In small-angle X-ray scattering experiments, the Qbeta virus was found to organize in different crystal structures in the presence of divalent salt and non-adsorbing polymer. Since a simple isotropic potential cannot explain the occurrence of all observed phases, we employ computer simulations to investigate how the surface charge distribution affects the virus interactions. Using a detailed model of the virus particle, we find an asymmetric ion distribution around the virus which gives rise to the different phases observed.

  3. Trigonometric approximation of the conjugate series of a function of generalized Lipchitz class by product summability

    NASA Astrophysics Data System (ADS)

    Sahu, Subrata K.; Acharya, D.; Nayak, P. C.; Misra, U. K.

    2016-06-01

    Trigonometric Fourier approximation and Lipchitz class of function had been introduced by Zygmund and McFadden respectively. Dealing with degree of approximation of conjugate series of a Fourier series of a function of Lipchitz class Misra et al. have established certain theorems. Extending their results, in this paper a theorem on trigonometric approximation of conjugate series of Fourier series of a function f ∈ W(Lp, ξ(t)) by product summability (E, s)(N, pn, qn) has been established.

  4. Explaining maximum variation in productivity requires phylogenetic diversity and single functional traits.

    PubMed

    Liu, Jiajia; Zhang, Xinxin; Song, Feifan; Zhou, Shurong; Cadotte, Marc W; Bradshaw, Corey J A

    2015-01-01

    Many community experiments have shown a positive relationship between plant biodiversity and community productivity, with biodiversity measured in multiple ways based on taxonomy, function, and phylogeny. Whether these different measures of biodiversity and their interactions explain variation in productivity in natural assemblages has rarely been tested. In a removal experiment using natural alpine assemblages in the Tibetan Plateau, we manipulated species richness and functional diversity to examine how different measures of biodiversity predict aboveground biomass production. We combined different biodiversity measures (functional, phylogenetic, richness, evenness) in generalized linear models to determine which combinations provided the most parsimonious explanations of variation in biomass production. Although multivariate functional diversity indices alone consistently explained more variation in productivity than other single measures, phylogenetic diversity and plant height represented the most parsimonious combination. In natural assemblages, single metrics alone cannot fully explain ecosystem function. Instead, a combination of phylogenetic diversity and traits with weak or no phylogenetic signal is required to explain the effects of biodiversity loss on ecosystem function.

  5. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography*

    PubMed Central

    Darrow, Michele C.; Sergeeva, Oksana A.; Isas, Jose M.; Galaz-Montoya, Jesús G.; King, Jonathan A.; Langen, Ralf; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain. PMID:25995452

  6. Protein A chromatography increases monoclonal antibody aggregation rate during subsequent low pH virus inactivation hold.

    PubMed

    Mazzer, Alice R; Perraud, Xavier; Halley, Jennifer; O'Hara, John; Bracewell, Daniel G

    2015-10-09

    Protein A chromatography is a near-ubiquitous method of mAb capture in bioprocesses. The use of low pH buffer for elution from protein A is known to contribute to product aggregation. Yet, a more limited set of evidence suggests that low pH may not be the sole cause of aggregation in protein A chromatography, rather, other facets of the process may contribute significantly. This paper presents a well-defined method for investigating this problem. An IgG4 was incubated in elution buffer after protein A chromatography (typical of the viral inactivation hold) and the quantity of monomer in neutralised samples was determined by size exclusion chromatography; elution buffers of different pH values predetermined to induce aggregation of the IgG4 were used. Rate constants for monomer decay over time were determined by fitting exponential decay functions to the data. Similar experiments were implemented in the absence of a chromatography step, i.e. IgG4 aggregation at low pH. Rate constants for aggregation after protein A chromatography were considerably higher than those from low pH exposure alone; a distinct shift in aggregation rates was apparent across the pH range tested.

  7. Aggregation kinetics of human mesenchymal stem cells under wave motion.

    PubMed

    Tsai, Ang-Chen; Liu, Yijun; Yuan, Xuegang; Chella, Ravindran; Ma, Teng

    2016-12-20

    Human mesenchymal stem cells (hMSCs) are primary candidates in cell therapy and regenerative medicine but preserving their therapeutic potency following culture expansion is a significant challenge. hMSCs can spontaneously assemble into three-dimensional (3D) aggregates that enhance their regenerative properties. The present study investigated the impact of hydrodynamics conditions on hMSC aggregation kinetics under controlled rocking motion. While various laboratory methods have been developed for hMSC aggregate production, the rocking platform provides gentle mixing and can be scaled up using large bags as in wave motion bioreactors. The results show that the hMSC aggregation is mediated by cell adhesion molecules and that aggregate size distribution is influenced by seeding density, culture time, and hydrodynamic conditions. The analysis of fluid shear stress by COMSOL indicated that aggregate size distribution is inversely correlated with shear stress and that the rocking angle had a more pronounced effect on aggregate size distribution than the rocking speed due to its impact on shear stress. hMSC aggregates obtained from the bioreactor exhibit increased stemness, migratory properties, and expression of angiogenic factors. The results demonstrate the potential of the rocking platform to produce hMSC aggregates with controlled size distribution for therapeutic application.

  8. [Functional meat products; development and evaluation of their health-promoting properties].

    PubMed

    Olmedilla-Alonso, Begoña; Jiménez-Colmenero, Francisco

    2014-06-01

    For a number of reasons, meat products are an exceptionally adequate means for introducing different bioactive compounds into the diet without modifying eating habits. In recent years, there has been a notable development of meat products designed as potentially functional foods. Within the framework of the functional food, this article provides a general view of the reasons that motivate and justify their formulation, with special emphasis on: a) aspects to be considered in their design in order to be able to make nutrition claims and statements concerning their health-promoting properties; b) the strategies employed to optimize the presence of functional ingredients, favoring the presence of beneficial bioactive compounds and limiting others with negative consequences for our health, and c) the procedures for demonstrating a relationship between the consumption of potentially functional meat products with beneficial effects on health and the way in which these studies are reflected in the literature.

  9. In-situ Evaluation of Soil Organic Molecules: Functional Group Chemistry Aggregate Structures, Metal & Surface Complexation Using Soft X-Ray

    SciTech Connect

    Myneni, Satish, C

    2008-11-30

    Organic molecules are common in all Earth surface environments, and their composition and chemistry play an important role in a variety of biogeochemical reactions, such as mineral weathering, nutrient cycling and the solubility and transport of contaminants. However, most of what we know about the chemistry of these molecules comes from spectroscopy and microscopy studies of organic molecules extracted from different natural systems using either inorganic or organic solvents. Although all these methods gave us clues about the composition of these molecules, their composition and structure change with the extraction and the type of ex-situ analysis, their true behavior is less well understood. The goal of this project is to develop synchrotron instrumentation for studying natural organics, and to apply these recently developed synchrotron X-ray spectroscopy and microscopy techniques for understanding the: (1) functional group composition of naturally occurring organic molecules; (2) macromolecular structures of organic molecules; and (3) the nature of interactions of organic molecules with mineral surfaces in different environmental conditions.

  10. Overcoming duality: the fused bousfieldian function for modeling word production in verbal fluency tasks.

    PubMed

    Ehlen, Felicitas; Fromm, Ortwin; Vonberg, Isabelle; Klostermann, Fabian

    2016-10-01

    Word production is generally assumed to occur as a function of a broadly interconnected language system. In terms of verbal fluency tasks, word production dynamics can be assessed by analyzing respective time courses via curve fitting. Here, a new generalized fitting function is presented by merging the two dichotomous classical Bousfieldian functions into one overarching power function with an adjustable shape parameter. When applied to empirical data from verbal fluency tasks, the error of approximation was significantly reduced while also fulfilling the Bayesian information criterion, suggesting a superior overall application value. Moreover, the approach identified a previously unknown logarithmic time course, providing further evidence of an underlying lexical network structure. In view of theories on lexical access, the corresponding modeling differentiates task-immanent lexical suppression from automatic lexical coactivation. In conclusion, our approach indicates that process dynamics result from an increasing cognitive effort to suppress automatic network functions.

  11. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.

  12. Entropy production from chaoticity in Yang-Mills field theory with use of the Husimi function

    NASA Astrophysics Data System (ADS)

    Tsukiji, Hidekazu; Iida, Hideaki; Kunihiro, Teiji; Ohnishi, Akira; Takahashi, Toru T.

    2016-11-01

    We investigate possible entropy production in Yang-Mills (YM) field theory by using a quantum distribution function called the Husimi function fH(A ,E ,t ) for the YM field, which is given by a coarse graining of the Wigner function and non-negative. We calculate the Husimi-Wehrl entropy SHW(t )=-Tr fHlog fH defined as an integral over the phase space, for which two adaptations of the test-particle method are used combined with Monte Carlo method. We utilize the semiclassical approximation to obtain the time evolution of the distribution functions of the YM field, which is known to show chaotic behavior in the classical limit. We also make a simplification of the multidimensional phase-space integrals by making a product ansatz for the Husimi function, which is found to give a 10-20% overestimate of the Husimi-Wehrl entropy for a quantum system with a few degrees of freedom. We show that the quantum YM theory does exhibit the entropy production and that the entropy production rate agrees with the sum of positive Lyapunov exponents or the Kolmogorov-Sinai entropy, suggesting that the chaoticity of the classical YM field causes the entropy production in the quantum YM theory.

  13. Field kites: Crop-water production functions and the timing of water application for supplementary irrigation

    NASA Astrophysics Data System (ADS)

    Smilovic, M.; Gleeson, T.; Adamowski, J. F.

    2015-12-01

    Agricultural production is directly related to water management and water supply. The temporal distribution of water use throughout the growing season can significantly influence crop yield, and the facility to manage both the timing and amount of irrigation water may result in higher yields. The crop-water production function quantitatively evaluates the relationship between seasonal water use and crop yield. Previous efforts have attempted to describe and formalize the crop-water production function as a single-variable function of seasonal water use. However, these representations do not account for the effects of temporal distribution of water use and trivialize the associated variability in yields by assuming an optimized or arbitrary temporal distribution of soil moisture. This over-simplification renders the function inappropriate for recommendations related to irrigation scheduling, water management, economically optimal irrigation, water and agricultural productivity, and assessing the role of full and supplementary irrigation. We propose field kites, a novel representation of the crop-water production function that explicitly acknowledges crop yield variability as a function of both seasonal water use and associated temporal distributions of water use. Field kites are a tool that explicitly considers the farmers' capacity to manage their water resources, to more appropriately evaluate the optimal depth of irrigation water under water-limiting conditions. The field kite for winter wheat is presented both generally and cultivar- and climate-specific for Western Canada. The field kites are constructed using AquaCrop and previously validated cultivar-specific variables. Field kites provide the tools for water authorities and policy makers to evaluate agricultural production as it relates to farm water management, and to determine appropriate policies related to developing and supporting the necessary irrigation infrastructure to increase water productivity.

  14. Utilization of Food Processing By-products as Dietary, Functional, and Novel Fiber: A Review.

    PubMed

    Sharma, Satish Kumar; Bansal, Sangita; Mangal, Manisha; Dixit, Anil Kumar; Gupta, Ram K; Mangal, A K

    2016-07-26

    Fast growing food processing industry in most countries across the world, generates huge quantity of by-products, including pomace, hull, husk, pods, peel, shells, seeds, stems, stalks, bran, washings, pulp refuse, press cakes, etc., which have less use and create considerable environmental pollution. With growing interest in health promoting functional foods, the demand of natural bioactives has increased and exploration for new sources is on the way. Many of the food processing industrial by-products are rich sources of dietary, functional, and novel fibers. These by-products can be directly (or after certain modifications for isolation or purification of fiber) used for the manufacture of various foods, i.e. bread, buns, cake, pasta, noodles, biscuit, ice creams, yogurts, cheese, beverages, milk shakes, instant breakfasts, ice tea, juices, sports drinks, wine, powdered drink, fermented milk products, meat products and meat analogues, synthetic meat, etc. A comprehensive literature survey has been carried on this topic to give an overview in the field dietary fiber from food by-products. In this article, the developments in the definition of fiber, fiber classification, potential sources of dietary fibers in food processing by-products, their uses, functional properties, caloric content, energy values and the labelling regulations have been discussed.

  15. Holographic characterization of protein aggregates

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Zhong, Xiao; Ruffner, David; Stutt, Alexandra; Philips, Laura; Ward, Michael; Grier, David

    Holographic characterization directly measures the size distribution of subvisible protein aggregates in suspension and offers insights into their morphology. Based on holographic video microscopy, this analytical technique records and interprets holograms of individual aggregates in protein solutions as they flow down a microfluidic channel, without requiring labeling or other exceptional sample preparation. The hologram of an individual protein aggregate is analyzed in real time with the Lorenz-Mie theory of light scattering to measure that aggregate's size and optical properties. Detecting, counting and characterizing subvisible aggregates proceeds fast enough for time-resolved studies, and lends itself to tracking trends in protein aggregation arising from changing environmental factors. No other analytical technique provides such a wealth of particle-resolved characterization data in situ. Holographic characterization promises accelerated development of therapeutic protein formulations, improved process control during manufacturing, and streamlined quality assurance during storage and at the point of use. Mrsec and MRI program of the NSF, Spheryx Inc.

  16. Functional food. Product development, marketing and consumer acceptance--a review.

    PubMed

    Siró, István; Kápolna, Emese; Kápolna, Beáta; Lugasi, Andrea

    2008-11-01

    It was mainly the advances in understanding the relationship between nutrition and health that resulted in the development of the concept of functional foods, which means a practical and new approach to achieve optimal health status by promoting the state of well-being and possibly reducing the risk of disease. Functional foods are found virtually in all food categories, however products are not homogeneously scattered over all segments of the growing market. The development and commerce of these products is rather complex, expensive and risky, as special requirements should be answered. Besides potential technological obstacles, legislative aspects, as well as consumer demands need to be taken into consideration when developing functional food. In particular, consumer acceptance has been recognized as a key factor to successfully negotiate market opportunities. This paper offers a brief overview of the current functional food market situation in USA, Japan and some European countries completed with some comments on functional food future potential. It explores the main challenges of such product development focusing on the different factors determining the acceptance of functional food. Furthermore it discusses some prominent types of these food products currently on the market.

  17. Certain fractional integral formulas involving the product of generalized Bessel functions.

    PubMed

    Baleanu, D; Agarwal, P; Purohit, S D

    2013-01-01

    We apply generalized operators of fractional integration involving Appell's function F 3(·) due to Marichev-Saigo-Maeda, to the product of the generalized Bessel function of the first kind due to Baricz. The results are expressed in terms of the multivariable generalized Lauricella functions. Corresponding assertions in terms of Saigo, Erdélyi-Kober, Riemann-Liouville, and Weyl type of fractional integrals are also presented. Some interesting special cases of our two main results are presented. We also point out that the results presented here, being of general character, are easily reducible to yield many diverse new and known integral formulas involving simpler functions.

  18. Using symmetry-adapted optimized sum-of-products basis functions to calculate vibrational spectra

    NASA Astrophysics Data System (ADS)

    Leclerc, Arnaud; Carrington, Tucker

    2016-01-01

    Vibrational spectra can be computed without storing full-dimensional vectors by using low-rank sum-of-products (SOP) basis functions. We introduce symmetry constraints in the SOP basis functions to make it possible to separately calculate states in different symmetry subgroups. This is done using a power method to compute eigenvalues and an alternating least squares method to optimize basis functions. Owing to the fact that the power method favours the convergence of the lowest states, one must be careful not to exclude basis functions of some symmetries. Exploiting symmetry facilitates making assignments and improves the accuracy. The method is applied to the acetonitrile molecule.

  19. Gene analogue finder: a GRID solution for finding functionally analogous gene products

    PubMed Central

    Tulipano, Angelica; Donvito, Giacinto; Licciulli, Flavio; Maggi, Giorgio; Gisel, Andreas

    2007-01-01

    Background To date more than 2,1 million gene products from more than 100000 different species have been described specifying their function, the processes they are involved in and their cellular localization using a very well defined and structured vocabulary, the gene ontology (GO). Such vast, well defined knowledge opens the possibility of compare gene products at the level of functionality, finding gene products which have a similar function or are involved in similar biological processes without relying on the conventional sequence similarity approach. Comparisons within such a large space of knowledge are highly data and computing intensive. For this reason this project was based upon the use of the computational GRID, a technology offering large computing and storage resources. Results We have developed a tool, GENe AnaloGue FINdEr (ENGINE) that parallelizes the search process and distributes the calculation and data over the computational GRID, splitting the process into many sub-processes and joining the calculation and the data on the same machine and therefore completing the whole search in about 3 days instead of occupying one single machine for more than 5 CPU years. The results of the functional comparison contain potential functional analogues for more than 79000 gene products from the most important species. 46% of the analyzed gene products are well enough described for such an analysis to individuate functional analogues, such as well-known members of the same gene family, or gene products with similar functions which would never have been associated by standard methods. Conclusion ENGINE has produced a list of potential functionally analogous relations between gene products within and between species using, in place of the sequence, the gene description of the GO, thus demonstrating the potential of the GO. However, the current limiting factor is the quality of the associations of many gene products from non-model organisms that often have

  20. Generation of chimeras by aggregation of embryonic stem cells with diploid or tetraploid mouse embryos.

    PubMed

    Artus, Jérôme; Hadjantonakis, Anna-Katerina

    2011-01-01

    From the hybrid creatures of the Greek and Egyptian mythologies, the concept of the chimera has evolved and, in modern day biology, refers to an organism comprises of at least two populations of genetically distinct cells. Mouse chimeras have proven an invaluable tool for the generation of genetically modified strains. In addition, chimeras have been extensively used in developmental biology as a powerful tool to analyze the phenotype of specific mutations, to attribute function to gene products and to address the question of cell autonomy versus noncell autonomy of gene function. This chapter describes a simple and economical technique used to generate mouse chimeras by embryo aggregation. Multiple aggregation combinations are described each of which can be tailored to answer particular biological questions.

  1. Using new aggregation operators in rule-based intelligent control

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.; Chen, Yung-Yaw; Yager, Ronald R.

    1990-01-01

    A new aggregation operator is applied in the design of an approximate reasoning-based controller. The ordered weighted averaging (OWA) operator has the property of lying between the And function and the Or function used in previous fuzzy set reasoning systems. It is shown here that, by applying OWA operators, more generalized types of control rules, which may include linguistic quantifiers such as Many and Most, can be developed. The new aggregation operators, as tested in a cart-pole balancing control problem, illustrate improved performance when compared with existing fuzzy control aggregation schemes.

  2. Fractal structure of asphaltene aggregates.

    PubMed

    Rahmani, Nazmul H G; Dabros, Tadeusz; Masliyah, Jacob H

    2005-05-15

    A photographic technique coupled with image analysis was used to measure the size and fractal dimension of asphaltene aggregates formed in toluene-heptane solvent mixtures. First, asphaltene aggregates were examined in a Couette device and the fractal-like aggregate structures were quantified using boundary fractal dimension. The evolution of the floc structure with time was monitored. The relative rates of shear-induced aggregation and fragmentation/restructuring determine the steady-state floc structure. The average floc structure became more compact or more organized as the floc size distribution attained steady state. Moreover, the higher the shear rate is, the more compact the floc structure is at steady state. Second, the fractal dimensions of asphaltene aggregates were also determined in a free-settling test. The experimentally determined terminal settling velocities and characteristic lengths of the aggregates were utilized to estimate the 2D and 3D fractal dimensions. The size-density fractal dimension (D(3)) of the asphaltene aggregates was estimated to be in the range from 1.06 to 1.41. This relatively low fractal dimension suggests that the asphaltene aggregates are highly porous and very tenuous. The aggregates have a structure with extremely low space-filling capacity.

  3. Aggregation dynamics of rigid polyelectrolytes

    NASA Astrophysics Data System (ADS)

    Tom, Anvy Moly; Rajesh, R.; Vemparala, Satyavani

    2016-01-01

    Similarly charged polyelectrolytes are known to attract each other and aggregate into bundles when the charge density of the polymers exceeds a critical value that depends on the valency of the counterions. The dynamics of aggregation of such rigid polyelectrolytes are studied using large scale molecular dynamics simulations. We find that the morphology of the aggregates depends on the value of the charge density of the polymers. For values close to the critical value, the shape of the aggregates is cylindrical with height equal to the length of a single polyelectrolyte chain. However, for larger values of charge, the linear extent of the aggregates increases as more and more polymers aggregate. In both the cases, we show that the number of aggregates decrease with time as power laws with exponents that are not numerically distinguishable from each other and are independent of charge density of the polymers, valency of the counterions, density, and length of the polyelectrolyte chain. We model the aggregation dynamics using the Smoluchowski coagulation equation with kernels determined from the molecular dynamics simulations and justify the numerically obtained value of the exponent. Our results suggest that once counterions condense, effective interactions between polyelectrolyte chains short-ranged and the aggregation of polyelectrolytes are diffusion-limited.

  4. Role of intensive and extensive variables in a soup of firms in economy to address long run prices and aggregate data

    NASA Astrophysics Data System (ADS)

    Hosseiny, Ali; Gallegati, Mauro

    2017-03-01

    We review the production function and the hypothesis of equilibrium in the neoclassical framework. We notify that in a soup of sectors in economy, while capital and labor resemble extensive variables, wage and rate of return on capital act as intensive variables. As a result, Baumol and Bowen's statement of equal wages is inevitable from the thermodynamics point of view. We try to see how aggregation can be performed concerning the extensive variables in a soup of firms. We provide a toy model to perform aggregation for production and the labor income as extensive quantities in a neoclassical framework.

  5. Aggregates from natural and recycled sources; economic assessments for construction applications; a materials flow study

    USGS Publications Warehouse

    Wilburn, David R.; Goonan, Thomas G.

    1998-01-01

    Increased amounts of recycled materials are being used to supplement natural aggregates (derived from crushed stone, sand and gravel) in road construction. An understanding of the economics and factors affecting the level of aggregates recycling is useful in estimating the potential for recycling and in assessing the total supply picture of aggregates. This investigation includes a descriptive analysis of the supply sources, technology, costs, incentives, deterrents, and market relationships associated with the production of aggregates.

  6. A novel approach of integrated bioprocessing of cane molasses for production of prebiotic and functional bioproducts.

    PubMed

    Sharma, Manisha; Patel, Satya Narayan; Lata, Kusum; Singh, Umesh; Krishania, Meena; Sangwan, Rajender S; Singh, Sudhir P

    2016-11-01

    In this work, the sugar industry by-product cane molasses was investigated as feedstock for acceptor reactions by dextransucrase from Leuconostoc mesenteroides MTCC 10508, leading to the biosynthesis of oligosaccharides. The starch industry corn fiber residue was used as a source for acceptor molecules, maltose, in the reaction. Production of approximately 124g oligosaccharides (DP3-DP6) per kg of fresh molasses was achieved. Further, cane molasses based medium was demonstrated as a sole carbon source for L. mesenteroides growth and dextransucrase production. d-Fructose released by dextransucrase activity as processing by-product was transformed into the functional monosaccharide with zero caloric value, d-psicose, by inducing its epimerization. Quantitative analysis approximated 37g d-psicose per kg of fresh molasses. Thus, the study established a novel approach of integrated bioprocessing of cane molasses into prebiotic and functional food additives.

  7. Artificial aggregate made from waste stone sludge and waste silt.

    PubMed

    Chang, Fang-Chih; Lee, Ming-Yu; Lo, Shang-Lien; Lin, Jyh-Dong

    2010-11-01

    In this research, waste stone sludge obtained from slab stone processing and waste silt from aggregate washing plants were recycled to manufacture artificial aggregate. Fine-powdered stone sludge was mixed with waste silt of larger particle size; vibratory compaction was applied for good water permeability, resulting in a smaller amount of solidifying agent being used. For the densified packing used in this study, the mix proportion of waste stone sludge to waste silt was 35:50, which produced artificial aggregate of more compact structure with water absorption rate below 0.1%. In addition, applying vibratory compaction of 33.3 Hz to the artificial aggregate and curing for 28 days doubled the compressive strength to above 29.4 MPa. Hence, recycling of waste stone sludge and waste silt for the production of artificial aggregate not only offers a feasible substitute for sand and stone, but also an ecological alternative to waste management of sludge and silt.

  8. Leaf dry matter content predicts herbivore productivity, but its functional diversity is positively related to resilience in grasslands.

    PubMed

    Pakeman, Robin J

    2014-01-01

    This paper addresses whether the ecosystem service of animal production from grasslands depends upon plant functional identity, plant functional diversity or if the resilience of production is a function of this diversity. Using the results of nine grazing experiments the paper shows that productivity is highly dependent on one leaf trait, leaf dry matter content, as well as rainfall. Animal (secondary) productivity is not dependent on plant functional diversity, but the variability in productivity of grasslands is related to the functional diversity of leaf dry matter content. This and a range of independent studies have shown that functional diversity is reduced at high levels of grassland productivity, so it appears that there is a trade-off between productivity and the resilience of productivity in the face of environmental variation.

  9. Aspartic acid functions as carbonyl trapper to inhibit the formation of advanced glycation end products by chemical chaperone activity.

    PubMed

    Prasanna, Govindarajan; Saraswathi, N T

    2016-05-01

    Advanced glycation end products (AGEs) were implicated in pathology of numerous diseases. In this study, we present the bioactivity of aspartic acid (Asp) to inhibit the AGEs. Hemoglobin and bovine serum albumin (BSA) were glycated with glucose, fructose, and ribose in the presence and absence of Asp (100-200 μM). HbA1c inhibition was investigated using human blood and characterized by micro-column ion exchange chromatography. The effect of methyl glyoxal (MG) on hemoglobin and BSA was evaluated by fluorescence spectroscopy and gel electrophoresis. The effect of MG on red blood cells morphology was characterized by scanning electron micrographs. Molecular docking was performed on BSA with Asp. Asp is capable of inhibiting the formation of fluorescent AGEs by reacting with the reducing sugars. The presence of Asp as supplement in whole blood reduced the HbA1c% from 8.8 to 6.1. The presence of MG showed an increase in fluorescence and the presence of Asp inhibited the glycation thereby the fluorescence was quenched. MG also affected the electrophoretic mobility of hemoglobin and BSA by forming high molecular weight aggregates. Normal RBCs showed typical biconcave shape. MG modified RBCs showed twisted and elongated shape whereas the presence of ASP tends to protect RBC from twisting. Asp interacted with arginine residues of bovine serum albumin particularly ARG 194, ARG 198, and ARG 217 thereby stabilized the protein complex. We conclude that Asp has dual functions as a chemical chaperone to stabilize protein and as a dicarbonyl trapper, and thereby it can prevent the complications caused by glycation.

  10. Characterization of Aggregate Size in Taxus Suspension Cell Culture

    PubMed Central

    Kolewe, Martin E.; Henson, Michael A.; Roberts, Susan C.

    2015-01-01

    Plant cells grow as aggregates in suspension culture, but little is known about the dynamics of aggregation, and no routine methodology exists to measure aggregate size. In this study, we evaluate several different methods to characterize aggregate size in Taxus suspension cultures, in which aggregate diameters range from 50 μm to 2000 μm, including filtration and image analysis, and develop a novel method using a specially equipped Coulter counter system. We demonstrate the suitability of this technology to measure plant cell culture aggregates, and show that it can be reliably used to measure total biomass accumulation compared to standard methods such as dry weight. Furthermore, we demonstrate that all three methods can be used to measure an aggregate size distribution, but that the Coulter counter is more reliable and much faster, and also provides far better resolution. While absolute measurements of aggregate size differ based on the three evaluation techniques, we show that linear correlations are sufficient to account for these differences (R2 > 0.99). We then demonstrate the utility of the novel Coulter counter methodology by monitoring the dynamics of a batch process and find that the mean aggregate size increases by 55% during the exponential growth phase, but decreases during stationary phase. The results indicate that the Coulter counter method can be routinely used for advanced process characterization, particularly to study the relationship between aggregate size and secondary metabolite production, as well as a source of reliable experimental data for modeling aggregation dynamics in plant cell culture. PMID:20217417

  11. The great screen anomaly--a new frontier in product discovery through functional metagenomics.

    PubMed

    Ekkers, David Matthias; Cretoiu, Mariana Silvia; Kielak, Anna Maria; Elsas, Jan Dirk van

    2012-02-01

    Functional metagenomics, the study of the collective genome of a microbial community by expressing it in a foreign host, is an emerging field in biotechnology. Over the past years, the possibility of novel product discovery through metagenomics has developed rapidly. Thus, metagenomics has been heralded as a promising mining strategy of resources for the biotechnological and pharmaceutical industry. However, in spite of innovative work in the field of functional genomics in recent years, yields from function-based metagenomics studies still fall short of producing significant amounts of new products that are valuable for biotechnological processes. Thus, a new set of strategies is required with respect to fostering gene expression in comparison to the traditional work. These new strategies should address a major issue, that is, how to successfully express a set of unknown genes of unknown origin in a foreign host in high throughput. This article is an opinionating review of functional metagenomic screening of natural microbial communities, with a focus on the optimization of new product discovery. It first summarizes current major bottlenecks in functional metagenomics and then provides an overview of the general metagenomic assessment strategies, with a focus on the challenges that are met in the screening for, and selection of, target genes in metagenomic libraries. To identify possible screening limitations, strategies to achieve optimal gene expression are reviewed, examining the molecular events all the way from the transcription level through to the secretion of the target gene product.

  12. Solubilization and functionalization of sulfuric acid lignin generated during bioethanol production from woody biomass.

    PubMed

    Matsushita, Yasuyuki; Inomata, Toyoki; Hasegawa, Tatsuya; Fukushima, Kazuhiko

    2009-01-01

    Sulfuric acid lignin (SAL), which is formed as a by-product during the production of bioethanol from woody biomass, was solubilized and functionalized by hydrothermal reaction. SAL could be easily dissolved in an alkaline medium, especially sodium hydroxide solution, by this reaction. The soluble part of the reaction products (S-HSAL) could be dissolved at neutral pH. IR spectrometric analysis of SAL revealed that hydrophilic groups were introduced in it during the reaction. The dispersibility of S-HSAL was increased by sulfonation (SS-HSAL), and it was found to be an effective dispersant for gypsum paste.

  13. Small surfactant-like peptides can drive soluble proteins into active aggregates

    PubMed Central

    2012-01-01

    Background Inactive protein inclusion bodies occur commonly in Escherichia coli (E. coli) cells expressing heterologous proteins. Previously several independent groups have found that active protein aggregates or pseudo inclusion bodies can be induced by a fusion partner such as a cellulose binding domain from Clostridium cellulovorans (CBDclos) when expressed in E. coli. More recently we further showed that a short amphipathic helical octadecapeptide 18A (EWLKAFYEKVLEKLKELF) and a short beta structure peptide ELK16 (LELELKLKLELELKLK) have a similar property. Results In this work, we explored a third type of peptides, surfactant-like peptides, for performing such a "pulling-down" function. One or more of three such peptides (L6KD, L6K2, DKL6) were fused to the carboxyl termini of model proteins including Aspergillus fumigatus amadoriase II (AMA, all three peptides were used), Bacillus subtilis lipase A (LipA, only L6KD was used, hereinafter the same), Bacillus pumilus xylosidase (XynB), and green fluorescent protein (GFP), and expressed in E. coli. All fusions were found to predominantly accumulate in the insoluble fractions, with specific activities ranging from 25% to 92% of the native counterparts. Transmission electron microscopic (TEM) and confocal fluorescence microscopic analyses confirmed the formation of protein aggregates in the cell. Furthermore, binding assays with amyloid-specific dyes (thioflavin T and Cong red) to the AMA-L6KD aggregate and the TEM analysis of the aggregate following digestion with protease K suggested that the AMA-L6KD aggregate may contain structures reminiscent of amyloids, including a fibril-like structure core. Conclusions This study shows that the surfactant-like peptides L6KD and it derivatives can act as a pull-down handler for converting soluble proteins into active aggregates, much like 18A and ELK16. These peptide-mediated protein aggregations might have important implications for protein aggregation in vivo, and can be

  14. Theoretical and experimental analysis of the sedimentation kinetics of concentrated red cell suspensions in a centrifugal field: determination of the aggregation and deformation of RBC by flux density and viscosity functions.

    PubMed

    Lerche, D; Frömer, D

    2001-01-01

    detail the rheological behavior of suspended rigid spheres at low Reynolds numbers ranging from 10(-6) to 10(-3). The method here introduced also enabled us to investigate RBC suspensions with respect to the deformability and interactions of the cells by means of the separation analysis. Normal, rigid as well as aggregating RBC exhibited marked differences in the sedimentation kinetics, which were quantified by means of the flux and viscosity functions based on the theory of kinematic waves.

  15. Expanded function allied dental personnel and dental practice productivity and efficiency.

    PubMed

    Beazoglou, Tryfon J; Chen, Lei; Lazar, Vickie F; Brown, L Jackson; Ray, Subhash C; Heffley, Dennis R; Berg, Rob; Bailit, Howard L

    2012-08-01

    This study examined the impact of expanded function allied dental personnel on the productivity and efficiency of general dental practices. Detailed practice financial and clinical data were obtained from a convenience sample of 154 general dental practices in Colorado. In this state, expanded function dental assistants can provide a wide range of reversible dental services/procedures, and dental hygienists can give local anesthesia. The survey identified practices that currently use expanded function allied dental personnel and the specific services/procedures delegated. Practice productivity was measured using patient visits, gross billings, and net income. Practice efficiency was assessed using a multivariate linear program, Data Envelopment Analysis. Sixty-four percent of the practices were found to use expanded function allied dental personnel, and on average they delegated 31.4 percent of delegatable services/procedures. Practices that used expanded function allied dental personnel treated more patients and had higher gross billings and net incomes than those practices that did not; the more services they delegated, the higher was the practice's productivity and efficiency. The effective use of expanded function allied dental personnel has the potential to substantially expand the capacity of general dental practices to treat more patients and to generate higher incomes for dental practices.

  16. Floating ice-algal aggregates below melting arctic sea ice.

    PubMed

    Assmy, Philipp; Ehn, Jens K; Fernández-Méndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A; Hudson, Stephen R; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H H; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

    2013-01-01

    During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year.

  17. Population balance modeling of the conidial aggregation of Aspergillus niger.

    PubMed

    Lin, P-J; Grimm, L H; Wulkow, M; Hempel, D C; Krull, R

    2008-02-01

    Numerous biotechnological production processes are based on the submerse cultivation of filamentous fungi. Process design, however, is often hampered by the complex growth pattern of these organisms. In the morphologic development of coagulating filamentous fungi, like Aspergillus niger, conidial aggregation is the first step of filamentous morphogenesis. For a proper description of this phenomenon it is necessary to characterize conidial populations. Kinetic studies performed with an in-line particle size analyzer suggested that two distinct aggregation steps have to be considered. The first step of conidial aggregation starts immediately after inoculation. Both the rate constants of formation and disintegration of aggregates have been determined by measuring the concentration of conidia at the beginning of the cultivation and the concentration of particles at steady state during the first hours of cultivation. In contrast to the first aggregation step, where the collision of conidia is presumed to be responsible for the process, the second aggregation step is thought to be initiated by germination of conidia. Growing hyphae provide additional surface for the attachment of non- germinated conidia, which leads to a strong decrease in particle concentration. The specific hyphal length growth rate and the ratio of particle concentration to the growing adhesion hyphal surface are decisive matters of the second aggregation step. Both aggregation steps can be described by population dynamics and simulated using the program package PARSIVAL (PARticle SIze eVALution) for the treatment of general particle population balances.

  18. Reduction in soil aggregation in response to dust emission processes

    NASA Astrophysics Data System (ADS)

    Swet, Nitzan; Katra, Itzhak

    2016-09-01

    Dust emission by aeolian (wind) soil erosion depends on the topsoil properties of the source area, especially on the nature of the aggregates where most dust particles are held. Although the key role of soil aggregates in dust emission, the response of soil aggregation to aeolian processes and its implications for dust emission remain unknown. This study focuses on aggregate size distribution (ASD) analyses before and after in-situ aeolian experiments in semiarid loess soils that are associated with dust emission. Wind tunnel simulations show that particulate matter (PM) emission and saltation rates depend on the initial ASD and shear velocity. Under all initial ASD conditions, the content of saltator-sized aggregates (63-250 μm) increased by 10-34% due to erosion of macro-aggregates (> 500 μm), resulting in a higher size ratio (SR) between the saltators and macro-aggregates following the aeolian erosion. The results revealed that the saltator production increases significantly for soils that are subjected to short-term (anthropogenic) disturbance of the topsoil. The findings highlight a decrease in soil aggregation for all initial ASD's in response to aeolian erosion, and consequently its influence on the dust emission potential. Changes in ASD should be considered as a key parameter in dust emission models of complex surfaces.

  19. IgG Conformer's Binding to Amyloidogenic Aggregates

    PubMed Central

    Phay, Monichan; Welzel, Alfred T.; Williams, Angela D.; McWilliams-Koeppen, Helen P.; Blinder, Veronika; O'Malley, Tiernan T.; Solomon, Alan; Walsh, Dominic M.; O'Nuallain, Brian

    2015-01-01

    Amyloid-reactive IgGs isolated from pooled blood of normal individuals (pAbs) have demonstrated clinical utility for amyloid diseases by in vivo targeting and clearing amyloidogenic proteins and peptides. We now report the following three novel findings on pAb conformer's binding to amyloidogenic aggregates: 1) pAb aggregates have greater activity than monomers (HMW species > dimers > monomers), 2) pAbs interactions with amyloidogenic aggregates at least partially involves unconventional (non-CDR) interactions of F(ab) regions, and 3) pAb's activity can be easily modulated by trace aggregates generated during sample processing. Specifically, we show that HMW aggregates and dimeric pAbs present in commercial preparations of pAbs, intravenous immunoglobulin (IVIg), had up to ~200- and ~7-fold stronger binding to aggregates of Aβ and transthyretin (TTR) than the monomeric antibody. Notably, HMW aggregates were primarily responsible for the enhanced anti-amyloid activities of Aβ- and Cibacron blue-isolated IVIg IgGs. Human pAb conformer's binding to amyloidogenic aggregates was retained in normal human sera, and mimicked by murine pAbs isolated from normal pooled plasmas. An unconventional (non-CDR) component to pAb's activity was indicated from control human mAbs, generated against non-amyloid targets, binding to aggregated Aβ and TTR. Similar to pAbs, HMW and dimeric mAb conformers bound stronger than their monomeric forms to amyloidogenic aggregates. However, mAbs had lower maximum binding signals, indicating that pAbs were required to saturate a diverse collection of binding sites. Taken together, our findings strongly support further investigations on the physiological function and clinical utility of the inherent anti-amyloid activities of monomeric but not aggregated IgGs. PMID:26367058

  20. The semi-inclusive jet function in SCET and small radius resummation for inclusive jet production

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2016-10-01

    We introduce a new kind of jet function: the semi-inclusive jet function J i ( z, ω J , μ), which describes how a parton i is transformed into a jet with a jet radius R and energy fraction z = ω J /ω, with ω J and ω being the large light-cone momentum component of the jet and the corresponding parton i that initiates the jet, respectively. Within the framework of Soft Collinear Effective Theory (SCET) we calculate both J q ( z, ω J , μ) and J g ( z, ω J , μ) to the next-to-leading order (NLO) for cone and anti-kT algorithms. We demonstrate that the renormalization group (RG) equations for J i ( z, ω J , μ) follow exactly the usual DGLAP evolution, which can be used to perform the ln R resummation for inclusive jet cross sections with a small jet radius R. We clarify the difference between our RG equations for J i ( z, ω J , μ) and those for the so-called unmeasured jet functions J i ( ω J , μ), widely used in SCET for exclusive jet production. Finally, we present applications of the new semi-inclusive jet functions to inclusive jet production in e + e - and pp collisions. We demonstrate that single inclusive jet production in these collisions shares the same short-distance hard functions as single inclusive hadron production, with only the fragmentation functions D i h ( z, μ) replaced by J i ( z, ω J , μ). This can facilitate more efficient higher-order analytical computations of jet cross sections. We further match our ln R resummation at both LL R and NLL R to fixed NLO results and present the phenomenological implications for single inclusive jet production at the LHC.

  1. Topics in Probabilistic Judgment Aggregation

    ERIC Educational Resources Information Center

    Wang, Guanchun

    2011-01-01

    This dissertation is a compilation of several studies that are united by their relevance to probabilistic judgment aggregation. In the face of complex and uncertain events, panels of judges are frequently consulted to provide probabilistic forecasts, and aggregation of such estimates in groups often yield better results than could have been made…

  2. Mineral of the month: aggregates

    USGS Publications Warehouse

    Tepordei, Valentin V.

    2005-01-01

    Natural aggregates, consisting of crushed stone, and sand and gravel, are a major contributor to economic health, and have an amazing variety of uses. Aggregates are among the most abundant mineral resources and are major basic raw materials used by construction, agriculture and other industries that employ complex chemical and metallurgical processes.

  3. Spatial and Temporal Uncertainty of Crop Yield Aggregations

    NASA Technical Reports Server (NTRS)

    Porwollik, Vera; Mueller, Christoph; Elliott, Joshua; Chryssanthacopoulos, James; Iizumi, Toshichika; Ray, Deepak K.; Ruane, Alex C.; Arneth, Almut; Balkovic, Juraj; Ciais, Philippe; Deryng, Delphine; Folberth, Christian; Izaurralde, Robert C.; Jones, Curtis D.; Khabarov, Nikolay; Lawrence, Peter J.; Liu, Wenfeng; Pugh, Thomas A. M.; Reddy, Ashwan; Sakurai, Gen; Schmid, Erwin; Wang, Xuhui; Wu, Xiuchen; de Wit, Allard

    2016-01-01

    The aggregation of simulated gridded crop yields to national or regional scale requires information on temporal and spatial patterns of crop-specific harvested areas. This analysis estimates the uncertainty of simulated gridded yield time series related to the aggregation with four different harvested area data sets. We compare aggregated yield time series from the Global Gridded Crop Model Inter-comparison project for four crop types from 14 models at global, national, and regional scale to determine aggregation-driven differences in mean yields and temporal patterns as measures of uncertainty. The quantity and spatial patterns of harvested areas differ for individual crops among the four datasets applied for the aggregation. Also simulated spatial yield patterns differ among the 14 models. These differences in harvested areas and simulated yield patterns lead to differences in aggregated productivity estimates, both in mean yield and in the temporal dynamics. Among the four investigated crops, wheat yield (17% relative difference) is most affected by the uncertainty introduced by the aggregation at the global scale. The correlation of temporal patterns of global aggregated yield time series can be as low as for soybean (r = 0.28).For the majority of countries, mean relative differences of nationally aggregated yields account for10% or less. The spatial and temporal difference can be substantial higher for individual countries. Of the top-10 crop producers, aggregated national multi-annual mean relative difference of yields can be up to 67% (maize, South Africa), 43% (wheat, Pakistan), 51% (rice, Japan), and 427% (soybean, Bolivia).Correlations of differently aggregated yield time series can be as low as r = 0.56 (maize, India), r = 0.05*Corresponding (wheat, Russia), r = 0.13 (rice, Vietnam), and r = -0.01 (soybean, Uruguay). The aggregation to sub-national scale in comparison to country scale shows that spatial uncertainties can cancel out in countries with

  4. Aggregate and Heatmap Representations of Genome-Wide Localization Data Using VAP, a Versatile Aggregate Profiler.

    PubMed

    Brunelle, Mylène; Coulombe, Charles; Poitras, Christian; Robert, Marc-Antoine; Markovits, Alexei Nordell; Robert, François; Jacques, Pierre-Étienne

    2015-01-01

    In the analysis of experimental data corresponding to the signal enrichment of chromatin features such as histone modifications throughout the genome, it is often useful to represent the signal over known regions of interest, such as genes, using aggregate or individual profiles. In the present chapter, we describe and explain the best practices on how to generate such profiles as well as other usages of the versatile aggregate profiler (VAP) tool (Coulombe et al., Nucleic Acids Res 42:W485-W493, 2014), with a particular focus on the new functionalities introduced in version 1.1.0 of VAP.

  5. Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.

    PubMed

    Mitsuhashi, Satoshi

    2014-04-01

    Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine).

  6. Continuous production of nitrogen-functionalized graphene nanosheets for catalysis applications

    NASA Astrophysics Data System (ADS)

    Sanjeeva Rao, Kodepelly; Senthilnathan, Jaganathan; Ting, Jyh-Ming; Yoshimura, Masahiro

    2014-10-01

    This study reports the ``continuous production'' of high-quality, few-layer nitrogen-functionalized graphene nanosheets in aqueous solutions directly from graphite via a two-step method. The initial step utilizes our recently developed peroxide-mediated soft and green electrochemical exfoliation approach for the production of few-layer graphene nanosheets. The subsequent step, developed here, produces nitrogen-functionalized graphene nanosheets via selective alkylation/basic hydrolysis reactions using rather a simple nitrogen precursor bromoacetonitrile, which was never reported in the literature. A possible reaction mechanism of the nitrogen-functionalized graphene formation is proposed. The proposed method allows the quantification of the phenolic and hydroxyl functional groups of anodic few-layer graphene via the derivatization chemistry approach. Additionally, a nitrogen-functionalized graphene-gold nanocrystal hybrid is prepared using gold nanocrystals obtained via the microwave irradiation of H[AuCl4] and trisodium citrate solution. A systematic investigation demonstrates that the nitrogen-functionalized graphene-gold nanocrystal hybrid shows enhanced catalytic reduction of carbonyl compounds such as benzaldehyde.This study reports the ``continuous production'' of high-quality, few-layer nitrogen-functionalized graphene nanosheets in aqueous solutions directly from graphite via a two-step method. The initial step utilizes our recently developed peroxide-mediated soft and green electrochemical exfoliation approach for the production of few-layer graphene nanosheets. The subsequent step, developed here, produces nitrogen-functionalized graphene nanosheets via selective alkylation/basic hydrolysis reactions using rather a simple nitrogen precursor bromoacetonitrile, which was never reported in the literature. A possible reaction mechanism of the nitrogen-functionalized graphene formation is proposed. The proposed method allows the quantification of the phenolic

  7. Molecular aggregation of humic substances

    USGS Publications Warehouse

    Wershaw, R. L.

    1999-01-01

    Humic substances (HS) form molecular aggregates in solution and on mineral surfaces. Elucidation of the mechanism of formation of these aggregates is important for an understanding of the interactions of HS in soils arid natural waters. The HS are formed mainly by enzymatic depolymerization and oxidation of plant biopolymers. These reactions transform the aromatic and lipid plant components into amphiphilic molecules, that is, molecules that consist of separate hydrophobic (nonpolar) and hydrophilic (polar) parts. The nonpolar parts of the molecules are composed of relatively unaltered segments of plant polymers and the polar parts of carboxylic acid groups. These amphiphiles form membrane-like aggregates on mineral surfaces and micelle-like aggregates in solution. The exterior surfaces of these aggregates are hydrophilic, and the interiors constitute separate hydrophobic liquid-like phases.

  8. Sequence determinants of protein aggregation: tools to increase protein solubility

    PubMed Central

    Ventura, Salvador

    2005-01-01

    Escherichia coli is one of the most widely used hosts for the production of recombinant proteins. However, very often the target protein accumulates into insoluble aggregates in a misfolded and biologically inactive form. Bacterial inclusion bodies are major bottlenecks in protein production and are hampering the development of top priority research areas such structural genomics. Inclusion body formation was formerly considered to occur via non-specific association of hydrophobic surfaces in folding intermediates. Increasing evidence, however, indicates that protein aggregation in bacteria resembles to the well-studied process of amyloid fibril formation. Both processes appear to rely on the formation of specific, sequence-dependent, intermolecular interactions driving the formation of structured protein aggregates. This similarity in the mechanisms of aggregation will probably allow applying anti-aggregational strategies already tested in the amyloid context to the less explored area of protein aggregation inside bacteria. Specifically, new sequence-based approaches appear as promising tools to tune protein aggregation in biotechnological processes. PMID:15847694

  9. Relationships between functional diversity and aboveground biomass production in the Northern Tibetan alpine grasslands.

    PubMed

    Zhu, Juntao; Jiang, Lin; Zhang, Yangjian

    2016-09-26

    Functional diversity, the extent of functional differences among species in a community, drives biodiversity-ecosystem function (BEF) relationships. Here, four species traits and aboveground biomass production (ABP) were considered. We used two community-wide measures of plant functional composition, (1) community weighted means of trait values (CWM) and (2) functional trait diversity based on Rao's quadratic diversity (FDQ) to evaluate the effects of functional diversity on the ABP in the Northern Tibetan alpine grasslands. Both species and functional diversity were positively related to the ABP. Functional trait composition had a larger predictive power for the ABP than species diversity and FDQ, indicating a primary dependence of ecosystem property on the identity of dominant species in our study system. Multivariate functional diversity was ineffective in predicting ecosystem function due to the trade-offs among different traits or traits selection criterions. Our study contributes to a better understanding of the mechanisms driving the BEF relationships in stressed ecosystems, and especially emphasizes that abiotic and biotic factors affect the BEF relationships in alpine grasslands.

  10. Relationships between functional diversity and aboveground biomass production in the Northern Tibetan alpine grasslands

    PubMed Central

    Zhu, Juntao; Jiang, Lin; Zhang, Yangjian

    2016-01-01

    Functional diversity, the extent of functional differences among species in a community, drives biodiversity–ecosystem function (BEF) relationships. Here, four species traits and aboveground biomass production (ABP) were considered. We used two community-wide measures of plant functional composition, (1) community weighted means of trait values (CWM) and (2) functional trait diversity based on Rao’s quadratic diversity (FDQ) to evaluate the effects of functional diversity on the ABP in the Northern Tibetan alpine grasslands. Both species and functional diversity were positively related to the ABP. Functional trait composition had a larger predictive power for the ABP than species diversity and FDQ, indicating a primary dependence of ecosystem property on the identity of dominant species in our study system. Multivariate functional diversity was ineffective in predicting ecosystem function due to the trade-offs among different traits or traits selection criterions. Our study contributes to a better understanding of the mechanisms driving the BEF relationships in stressed ecosystems, and especially emphasizes that abiotic and biotic factors affect the BEF relationships in alpine grasslands. PMID:27666532

  11. Stability of individual loudness functions obtained by magnitude estimation and production

    NASA Technical Reports Server (NTRS)

    Hellman, R. P.

    1981-01-01

    A correlational analysis of individual magnitude estimation and production exponents at the same frequency is performed, as is an analysis of individual exponents produced in different sessions by the same procedure across frequency (250, 1000, and 3000 Hz). Taken as a whole, the results show that individual exponent differences do not decrease by counterbalancing magnitude estimation with magnitude production and that individual exponent differences remain stable over time despite changes in stimulus frequency. Further results show that although individual magnitude estimation and production exponents do not necessarily obey the .6 power law, it is possible to predict the slope of an equal-sensation function averaged for a group of listeners from individual magnitude estimation and production data. On the assumption that individual listeners with sensorineural hearing also produce stable and reliable magnitude functions, it is also shown that the slope of the loudness-recruitment function measured by magnitude estimation and production can be predicted for individuals with bilateral losses of long duration. Results obtained in normal and pathological ears thus suggest that individual listeners can produce loudness judgements that reveal, although indirectly, the input-output characteristic of the auditory system.

  12. Functional significance of dinitrogen fixation in sustaining coral productivity under oligotrophic conditions

    PubMed Central

    Cardini, Ulisse; Bednarz, Vanessa N.; Naumann, Malik S.; van Hoytema, Nanne; Rix, Laura; Foster, Rachel A.; Al-Rshaidat, Mamoon M. D.; Wild, Christian

    2015-01-01

    Functional traits define species by their ecological role in the ecosystem. Animals themselves are host–microbe ecosystems (holobionts), and the application of ecophysiological approaches can help to understand their functioning. In hard coral holobionts, communities of dinitrogen (N2)-fixing prokaryotes (diazotrophs) may contribute a functional trait by providing bioavailable nitrogen (N) that could sustain coral productivity under oligotrophic conditions. This study quantified N2 fixation by diazotrophs associated with four genera of hermatypic corals on a northern Red Sea fringing reef exposed to high seasonality. We found N2 fixation activity to be 5- to 10-fold higher in summer, when inorganic nutrient concentrations were lowest and water temperature and light availability highest. Concurrently, coral gross primary productivity remained stable despite lower Symbiodinium densities and tissue chlorophyll a contents. In contrast, chlorophyll a content per Symbiodinium cell increased from spring to summer, suggesting that algal cells overcame limitation of N, an essential element for chlorophyll synthesis. In fact, N2 fixation was positively correlated with coral productivity in summer, when its contribution was estimated to meet 11% of the Symbiodinium N requirements. These results provide evidence of an important functional role of diazotrophs in sustaining coral productivity when alternative external N sources are scarce. PMID:26511052

  13. Linking Ecosystem Services Benefit Transfer Databases and Ecosystem Services Production Function Libraries

    EPA Science Inventory

    The quantification or estimation of the economic and non-economic values of ecosystem services can be done from a number of distinct approaches. For example, practitioners may use ecosystem services production function models (ESPFMs) for a particular location, or alternatively, ...

  14. Bayesian analysis of cross-prefectural production function with time varying structure in Japan

    NASA Astrophysics Data System (ADS)

    Kyo, Koki; Noda, Hideo

    2006-11-01

    A cross-prefectural production function (CPPF) in Japan is constructed in a set of Bayesian models to examine the performance of Japan's post-war economy. The parameters in the model are estimated by using the procedure of a Monte Carlo filter together with the method of maximum likelihood. The estimated results are applied to regional and historical analysis of the Japanese economy.

  15. 78 FR 22899 - Certain Electronic Devices Having Placeshifting or Display Replication Functionality and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-17

    ... COMMISSION Certain Electronic Devices Having Placeshifting or Display Replication Functionality and Products... the sale within the United States after importation of certain electronic devices having placeshifting... Commission's Rules of Practice and Procedure, 19 CFR 210.10 (2012). Scope of Investigation: Having...

  16. Nutritional approach for designing meat-based functional food products with nuts.

    PubMed

    Olmedilla-Alonso, B; Granado-Lorencio, F; Herrero-Barbudo, C; Blanco-Navarro, I

    2006-01-01

    Meat and meat products are essential components of diets in developed countries and despite the convincing evidence that relate them to an increased risk for CVD, a growing consumption of meat products is foreseen. Epidemiological studies show that regular consumption of nuts, in general, and walnuts in particular, correlates inversely with myocardial infarction and ischaemic vascular disease. We assess the nutritional basis for and technological approach to the development of functional meat-based products potentially relevant in cardiovascular disease (CVD) risk reduction. Using the available strategies in the meat industry (reformulation processes) and a food-based approach, we address the design and development of restructured beef steak with added walnuts, potentially functional for CVD risk reduction. Its adequacy as a vehicle for active nutrients is confirmed by a pharmacokinetic pilot study in humans using gamma-tocopherol as an exposure biomarker in chylomicrons during the post-prandial state. Effect and potential "functionality" is being assessed by a dietary intervention study in subjects at risk and markers and indicators related to CVD are being evaluated. Within the conceptual framework of evidence-based medicine, development of meat-based functional products may become a useful approach for specific applications, with a potential market and health benefits of great importance at a population level.

  17. CHLORINATION BY-PRODUCTS IN DRINKING WATER AND MENSTRUAL CYCLE FUNCTION

    EPA Science Inventory

    Chlorination by-Products in Drinking Water and Menstrual Cycle Function

    Gayle C. Windham1, Kirsten Waller2, Meredith Anderson2, Laura Fenster1, Pauline Mendola3, Shanna Swan4

    1California Department of Health Services, Division of Environmental and Occupational Disea...

  18. Estimation of a Frontier Production Function for the South Carolina Educational Process.

    ERIC Educational Resources Information Center

    Cooper, Samuel T.; Cohn, Elchanan

    1997-01-01

    Estimates frontier production functions for South Carolina's educational process, using data from 541 classes. Classes taught by teachers who received merit awards show greater mathematics and reading achievement gain scores, as do classes with fewer free-lunch students. There was a positive relationship between achievement and (larger) class…

  19. Strain-dependent profile of misfolded prion protein aggregates

    PubMed Central

    Morales, Rodrigo; Hu, Ping Ping; Duran-Aniotz, Claudia; Moda, Fabio; Diaz-Espinoza, Rodrigo; Chen, Baian; Bravo-Alegria, Javiera; Makarava, Natallia; Baskakov, Ilia V.; Soto, Claudio

    2016-01-01

    Prions are composed of the misfolded prion protein (PrPSc) organized in a variety of aggregates. An important question in the prion field has been to determine the identity of functional PrPSc aggregates. In this study, we used equilibrium sedimentation in sucrose density gradients to separate PrPSc aggregates from three hamster prion strains (Hyper, Drowsy, SSLOW) subjected to minimal manipulations. We show that PrPSc aggregates distribute in a wide range of arrangements and the relative proportion of each species depends on the prion strain. We observed a direct correlation between the density of the predominant PrPSc aggregates and the incubation periods for the strains studied. The relative presence of PrPSc in fractions of different sucrose densities was indicative of the protein deposits present in the brain as analyzed by histology. Interestingly, no association was found between sensitivity to proteolytic degradation and aggregation profiles. Therefore, the organization of PrP molecules in terms of the density of aggregates generated may determine some of the particular strain properties, whereas others are independent from it. Our findings may contribute to understand the mechanisms of strain variation and the role of PrPSc aggregates in prion-induced neurodegeneration. PMID:26877167

  20. Strain-dependent profile of misfolded prion protein aggregates.

    PubMed

    Morales, Rodrigo; Hu, Ping Ping; Duran-Aniotz, Claudia; Moda, Fabio; Diaz-Espinoza, Rodrigo; Chen, Baian; Bravo-Alegria, Javiera; Makarava, Natallia; Baskakov, Ilia V; Soto, Claudio

    2016-02-15

    Prions are composed of the misfolded prion protein (PrP(Sc)) organized in a variety of aggregates. An important question in the prion field has been to determine the identity of functional PrP(Sc) aggregates. In this study, we used equilibrium sedimentation in sucrose density gradients to separate PrP(Sc) aggregates from three hamster prion strains (Hyper, Drowsy, SSLOW) subjected to minimal manipulations. We show that PrP(Sc) aggregates distribute in a wide range of arrangements and the relative proportion of each species depends on the prion strain. We observed a direct correlation between the density of the predominant PrP(Sc) aggregates and the incubation periods for the strains studied. The relative presence of PrP(Sc) in fractions of different sucrose densities was indicative of the protein deposits present in the brain as analyzed by histology. Interestingly, no association was found between sensitivity to proteolytic degradation and aggregation profiles. Therefore, the organization of PrP molecules in terms of the density of aggregates generated may determine some of the particular strain properties, whereas others are independent from it. Our findings may contribute to understand the mechanisms of strain variation and the role of PrP(Sc) aggregates in prion-induced neurodegeneration.

  1. Scalable production of microbially-mediated ZnS nanoparticles and application to functional thin films

    SciTech Connect

    Moon, Ji Won; Ivanov, Ilia N; Joshi, Pooran C; Armstrong, Beth L; Wang, Wei; Jung, Hyunsung; Rondinone, Adam Justin; Jellison Jr, Gerald Earle; Meyer III, Harry M; Jang, Gyoung Gug; Meisner, Roberta; Duty, Chad E; Phelps, Tommy Joe

    2014-01-01

    A series of semiconducting zinc sulfide (ZnS) nanoparticles were scalably, reproducibly, controllably, and economically synthesized with anaerobic metal-reducing Thermoanaerobacter species. They reduced partially oxidized sulfur sources to sulfides that extracellularly and thermodynamically incorporated with zinc ions to produce sparingly soluble ZnS nanoparticles with ~5 nm crystallites at yields of ~5 g l 1 month 1. A predominant sphalerite formation was facilitated by rapid precipitation kinetics, low cation/anion ratio, higher zinc concentration, water stabilization, or some combination of the four. The sphalerite ZnS nanoparticles exhibited narrow size distribution, high emission intensity, and few native defects. Scale-up and emission tunability using copper-doping were confirmed spectroscopically. Surface characterization was determined using Fourier transform infrared and X-ray photoelectron spectroscopies, which confirmed amine and carboxylic acid not only maintaining a nano-dimensional average crystallite size, but also increasing aggregation. Application of ZnS nanoparticle ink to a functional thin film was successfully tested for potential future applications.

  2. Quantum entanglement and the communication complexity of the inner product function

    SciTech Connect

    Cleve, R.; Dam, W. van |; Nielsen, M. |; Tapp, A.

    1998-08-01

    The authors consider the communication complexity of the binary inner product function in a variation of the two-party scenario where the parties have an a priori supply of particles in an entangled quantum state. They prove linear lower bounds for both exact protocols, as well as for protocols that determine the answer with bounded-error probability. The proofs employ a novel kind of quantum reduction from multibit communication problems to the problem of computing the inner product. The communication required for the former problem can then be bounded by an application of Holevo`s theorem. They also give a specific example of a probabilistic scenario where entanglement reduces the communication complexity of the inner product function by one bit.

  3. Functional chromatography reveals three natural products that target the same protein with distinct mechanisms of action

    PubMed Central

    Kang, MinJin; Wu, Tongde; Wijeratne, E. M. Kithsiri; Lau, Eric C.; Mason, Damian J.; Mesa, Celestina; Tillotson, Joseph; Zhang, Donna D.; Gunatilaka, A. A. Leslie; La Clair, James J.

    2014-01-01

    Access to lead compounds with defined molecular targets continues to be a barrier to the translation of natural product resources. As a solution, we have developed a system that uses discreet, recombinant proteins as the vehicles for natural product isolation. Here, we describe the use of this functional chromatographic method to identify natural products that bind to the AAA+ chaperone, p97, a promising cancer target. Application of this method to a panel of fungal and plant extracts identified rheoemodin, 1-hydroxydehydroherbarin and phomapyrrolidone A as distinct p97 modulators. Excitingly, each of these molecules displayed a unique mechanism of p97 modulation. This discovery provides strong support for the application of functional chromatography to the discovery of protein modulators that would likely escape traditional high-throughput or phenotypic screening platforms. PMID:25125376

  4. Xoconostle fruit (Opuntia matudae Scheinvar cv. Rosa) by-products as potential functional ingredients.

    PubMed

    Morales, Patricia; Barros, Lillian; Ramírez-Moreno, Esther; Santos-Buelga, Celestino; Ferreira, Isabel C F R

    2015-10-15

    There is a lack of information on the potential use of xoconostle cultivars as sources of antioxidants for food, pharmaceutical and colorant industries. The aim of this study was to provide a phytochemical characterisation and antioxidant activity evaluation of Opuntia matudae Scheinvar cv. Rosa by-products (epicarp and endocarp mucilage's), in order to evaluate their interest as sources of functional ingredients for human or animal foods. These by-products showed a high content in glucose, citric and linoleic acids, tocopherols, and isorhamnetin-O-(di-deoxyhexosyl-hexoside) (mainly in epicarp), and presented relevant antioxidant properties. The obtained results support the use of O. matudae Scheinvar cv. Rosa agro-industrial by-products as functional food ingredients, namely for antioxidant-enriched formulations, instead of being discarded.

  5. Quality, Functionality and Shelf Life of Fermented Meat and Meat Products: A Review.

    PubMed

    Kumar, Pavan; Chatli, M K; Verma, Akhilesh K; Mehta, Nitin; Malav, O P; Kumar, Devendra; Sharma, Neelesh

    2015-10-13

    Fermentation of meat is a traditional energy efficient preservation method widely used for improving quality, functionality, keeping quality and shelf life of fermented meat products. Fermentation of meat causes number of physical, biochemical and microbial changes, which eventually imparting functional properties, sensory characteristics and nutritional aspects of these products and inhibit the growth of various pathogenic and spoilage microorganisms. Those changes include acidification (carbohydrate catabolism), solubilization and gelation of myofibrillar and srcoplasmic proteins of muscle, degradation of proteins and lipids, reduction of nitrate into nitrite, formation of nitrosomyoglobin and dehydration. Dry fermented sausages are increasingly being used as carrier for probiotics. The production of biogenic amines during fermentation can be controlled by selecting proper starter cultures and other preventive measures such as quality of raw materials, hygienic measures, temperature etc.

  6. Strangeness production as a function of charged particle multiplicity in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Bianchi, Livio

    2016-12-01

    Recent measurements performed in high-multiplicity proton-proton (pp) and proton-lead (p-Pb) collisions have shown features that are reminiscent of those observed in lead-lead (Pb-Pb) collisions. These observations warrant a comprehensive measurement of the production of identified particles. We report on the production of KS0, Λ, Λ ‾, Ξ± and Ω± at mid-rapidity measured as a function of multiplicity in pp collisions at √{ s} = 7 TeV with the ALICE experiment. Spectral shapes studied both for individual particles and via particle ratios such as (Λ / KS0) as a function of pT exhibit an evolution with event multiplicity and the production rates of hyperons are observed to increase more strongly than those of non-strange hadrons. These phenomena are qualitatively similar to the ones observed in p-Pb and Pb-Pb collisions.

  7. Predictive response surface model for heat-induced rheological changes and aggregation of whey protein concentrate.

    PubMed

    Alvarez, Pedro A; Emond, Charles; Gomaa, Ahmed; Remondetto, Gabriel E; Subirade, Muriel

    2015-02-01

    Whey proteins are now far more than a by-product of cheese processing. In the last 2 decades, food manufacturers have developed them as ingredients, with the dairy industry remaining as a major user. For many applications, whey proteins are modified (denatured) to alter their structure and functional properties. The objective of this research was to study the influence of 85 to 100 °C, with protein concentration of 8% to 12%, and treatment times of 5 to 30 min, while measuring rheological properties (storage modulus, loss modulus, and complex viscosity) and aggregation (intermolecular beta-sheet formation) in dispersions of whey protein concentrate (WPC). A Box-Behnken Response Surface Methodology modeled the heat denaturation of liquid sweet WPC at 3 variables and 3 levels. The model revealed a very significant fit for viscoelastic properties, and a lesser fit for protein aggregation, at temperatures not previously studied. An exponential increase of rheological parameters was governed by protein concentration and temperature, while a modest linear relationship of aggregation was governed by temperature. Models such as these can serve as valuable guides to the ingredient and dairy industries to develop target products, as whey is a major ingredient in many functional foods.

  8. Ingredient Functionality in Multilayered Dough-margarine Systems and the Resultant Pastry Products: A Review.

    PubMed

    Ooms, Nand; Pareyt, Bram; Brijs, Kristof; Delcour, Jan A

    2016-10-02

    Pastry products are produced from heterogeneous multilayered dough systems. The main ingredients are flour, water, fat and sugar for puff pastry, and the same plus yeast for fermented pastry. Key aspects in pastry production are (i) building laminated dough containing alternating layers of dough and bakery fat and (ii) maintaining this multilayered structure during processing to allow for steam entrapment for proper dough lift during baking. Although most authors agree on the importance of gluten and fat for maintaining the integrity of the different layers, detailed studies on their specific function are lacking. The exact mechanism of steam entrapment during dough lift and the relative contribution of water set free from the fat phase during baking also remain unclear. This review brings together current knowledge on pastry products and the factors determining (intermediate) product quality. Its focus is on flour constituents, fat, water, and (where applicable) yeast during the different production stages of pastry products. Future research needs are addressed as the knowledge on biochemical and physical changes occurring in flour constituents and other ingredients during pastry production and their effect on product quality is currently inadequate.

  9. Orthogonal flexible Rydberg aggregates

    NASA Astrophysics Data System (ADS)

    Leonhardt, K.; Wüster, S.; Rost, J. M.

    2016-02-01

    We study the link between atomic motion and exciton transport in flexible Rydberg aggregates, assemblies of highly excited light alkali-metal atoms, for which motion due to dipole-dipole interaction becomes relevant. In two one-dimensional atom chains crossing at a right angle adiabatic exciton transport is affected by a conical intersection of excitonic energy surfaces, which induces controllable nonadiabatic effects. A joint exciton-motion pulse that is initially governed by a single energy surface is coherently split into two modes after crossing the intersection. The modes induce strongly different atomic motion, leading to clear signatures of nonadiabatic effects in atomic density profiles. We have shown how this scenario can be exploited as an exciton switch, controlling direction and coherence properties of the joint pulse on the second of the chains [K. Leonhardt et al., Phys. Rev. Lett. 113, 223001 (2014), 10.1103/PhysRevLett.113.223001]. In this article we discuss the underlying complex dynamics in detail, characterize the switch, and derive our isotropic interaction model from a realistic anisotropic one with the addition of a magnetic bias field.

  10. Formation and structure of stable aggregates in binary diffusion-limited cluster-cluster aggregation processes

    NASA Astrophysics Data System (ADS)

    López-López, J. M.; Moncho-Jordá, A.; Schmitt, A.; Hidalgo-Álvarez, R.

    2005-09-01

    Binary diffusion-limited cluster-cluster aggregation processes are studied as a function of the relative concentration of the two species. Both, short and long time behaviors are investigated by means of three-dimensional off-lattice Brownian Dynamics simulations. At short aggregation times, the validity of the Hogg-Healy-Fuerstenau approximation is shown. At long times, a single large cluster containing all initial particles is found to be formed when the relative concentration of the minority particles lies above a critical value. Below that value, stable aggregates remain in the system. These stable aggregates are composed by a few minority particles that are highly covered by majority ones. Our off-lattice simulations reveal a value of approximately 0.15 for the critical relative concentration. A qualitative explanation scheme for the formation and growth of the stable aggregates is developed. The simulations also explain the phenomenon of monomer discrimination that was observed recently in single cluster light scattering experiments.

  11. Reorganization of brain function during force production after stroke: A Systematic Review of the Literature

    PubMed Central

    Kokotilo, Kristen J; Eng, Janice J; Boyd, Lara A

    2011-01-01

    Damage to motor areas of the brain, caused by stroke, can produce devastating motor deficits, including aberrant control of force. Reorganization of brain function has been identified as one of the fundamental mechanisms involved in recovery of motor control after stroke, and recent advances in neuroimaging have enabled study of this brain reorganization. This review focuses on neuroimaging studies that have examined reorganization of brain function during force production and force modulation after stroke. Type and extent of reorganization after stroke was characterized via three factors: severity of injury, time after stroke and the impact of therapeutic interventions on brain activation during force production. Twenty-six studies meeting the inclusion criteria could be identified in MEDLINE (1980 to 2007). Relevant characteristics of studies (lesion location, chronicity of stroke, motor task) and mapping techniques varied widely. During force production, increased activation in secondary motor areas occurred in persons with more severe strokes. Also, reduced recruitment of secondary motor areas during force production was found as a function of increased time since stroke. During force modulation, increased activation in motor areas occurred with greater force generation. In addition, persons with more severe stroke showed relatively greater activation with rising force as compared to persons with less severe stroke. Lastly, alteration of brain activation during and after rehabilitative interventions in persons with stroke occurred in some studies. This systematic review establishes that reorganization of brain function during force production and force modulation can occur after stroke. These findings imply that therapeutic strategies that may be able to target brain reorganization to improve force control and functional recovery after stroke. PMID:19265770

  12. Hydrogen peroxide production regulates the mitochondrial function in insulin resistant muscle cells: effect of catalase overexpression.

    PubMed

    Barbosa, Marina R; Sampaio, Igor H; Teodoro, Bruno G; Sousa, Thais A; Zoppi, Claudio C; Queiroz, André L; Passos, Madla A; Alberici, Luciane C; Teixeira, Felipe R; Manfiolli, Adriana O; Batista, Thiago M; Cappelli, Ana Paula Gameiro; Reis, Rosana I; Frasson, Danúbia; Kettelhut, Isis C; Parreiras-e-Silva, Lucas T; Costa-Neto, Claudio M; Carneiro, Everardo M; Curi, Rui; Silveira, Leonardo R

    2013-10-01

    The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1α transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500μM) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with β-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1α transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and β-oxidation of fatty acids.

  13. Generating functional analysis of minority games with inner product strategy definitions

    NASA Astrophysics Data System (ADS)

    Coolen, A. C. C.; Shayeghi, N.

    2008-08-01

    We use generating functional methods to solve the so-called inner product versions of the minority game (MG), with fake and/or real market histories, by generalizing the theory developed recently for look-up table MGs with real histories. The phase diagrams of the look-up table and inner product MG versions are generally found to be identical, with the exception of inner product MGs where histories are sampled linearly, which are found to be structurally critical. However, we encounter interesting differences both in the theory (where the role of the history frequency distribution in look-up table MGs is taken over by the eigenvalue spectrum of a history covariance matrix in inner product MGs) and in the static and dynamic phenomenology of the models. Our theoretical predictions are supported by numerical simulations.

  14. A scalable system for production of functional pancreatic progenitors from human embryonic stem cells.

    PubMed

    Schulz, Thomas C; Young, Holly Y; Agulnick, Alan D; Babin, M Josephine; Baetge, Emmanuel E; Bang, Anne G; Bhoumik, Anindita; Cepa, Igor; Cesario, Rosemary M; Haakmeester, Carl; Kadoya, Kuniko; Kelly, Jonathan R; Kerr, Justin; Martinson, Laura A; McLean, Amanda B; Moorman, Mark A; Payne, Janice K; Richardson, Mike; Ross, Kelly G; Sherrer, Eric S; Song, Xuehong; Wilson, Alistair Z; Brandon, Eugene P; Green, Chad E; Kroon, Evert J; Kelly, Olivia G; D'Amour, Kevin A; Robins, Allan J

    2012-01-01

    Development of a human embryonic stem cell (hESC)-based therapy for type 1 diabetes will require the translation of proof-of-principle concepts into a scalable, controlled, and regulated cell manufacturing process. We have previously demonstrated that hESC can be directed to differentiate into pancreatic progenitors that mature into functional glucose-responsive, insulin-secreting cells in vivo. In this study we describe hESC expansion and banking methods and a suspension-based differentiation system, which together underpin an integrated scalable manufacturing process for producing pancreatic progenitors. This system has been optimized for the CyT49 cell line. Accordingly, qualified large-scale single-cell master and working cGMP cell banks of CyT49 have been generated to provide a virtually unlimited starting resource for manufacturing. Upon thaw from these banks, we expanded CyT49 for two weeks in an adherent culture format that achieves 50-100 fold expansion per week. Undifferentiated CyT49 were then aggregated into clusters in dynamic rotational suspension culture, followed by differentiation en masse for two weeks with a four-stage protocol. Numerous scaled differentiation runs generated reproducible and defined population compositions highly enriched for pancreatic cell lineages, as shown by examining mRNA expression at each stage of differentiation and flow cytometry of the final population. Islet-like tissue containing glucose-responsive, insulin-secreting cells was generated upon implantation into mice. By four- to five-months post-engraftment, mature neo-pancreatic tissue was sufficient to protect against streptozotocin (STZ)-induced hyperglycemia. In summary, we have developed a tractable manufacturing process for the generation of functional pancreatic progenitors from hESC on a scale amenable to clinical entry.

  15. Kinetics of Aggregation with Choice

    DOE PAGES

    Ben-Naim, Eli; Krapivsky, Paul

    2016-12-01

    Here we generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters.We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tailsmore » of the density are overpopulated, at the expense of the density of moderate-size clusters. Finally, we also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.« less

  16. Kinetics of Aggregation with Choice

    SciTech Connect

    Ben-Naim, Eli; Krapivsky, Paul

    2016-12-01

    Here we generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters.We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tails of the density are overpopulated, at the expense of the density of moderate-size clusters. Finally, we also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.

  17. Recent advances in food biopeptides: production, biological functionalities and therapeutic applications.

    PubMed

    Saadi, Sami; Saari, Nazamid; Anwar, Farooq; Hamid, Azizah Abdul; Mohd Ghazali, Hasanah

    2015-01-01

    The growing momentum of several common life-style diseases such as myocardial infarction, cardiovascular disorders, stroke, hypertension, diabetes, and atherosclerosis has become a serious global concern. Recent developments in the field of proteomics offering promising solutions to solving such health problems stimulates the uses of biopeptides as one of the therapeutic agents to alleviate disease-related risk factors. Functional peptides are typically produced from protein via enzymatic hydrolysis under in vitro or in vivo conditions using different kinds of proteolytic enzymes. An array of biological activities, including antioxidative, antihypertensive, antidiabetic and immunomodulating has been ascribed to different types of biopeptides derived from various food sources. In fact, biopeptides are nutritionally and functionally important for regulating some physiological functions in the body; however, these are yet to be extensively addressed with regard to their production through advance strategies, mechanisms of action and multiple biological functionalities. This review mainly focuses on recent biotechnological advances that are being made in the field of production in addition to covering the mode of action and biological activities, medicinal health functions and therapeutic applications of biopeptides. State-of-the-art strategies that can ameliorate the efficacy, bioavailability, and functionality of biopeptides along with their future prospects are likewise discussed.

  18. Polyglutamine Aggregation in Huntington Disease: Does Structure Determine Toxicity?

    PubMed

    Hoffner, Guylaine; Djian, Philippe

    2015-12-01

    Huntington disease is a dominantly inherited disease of the central nervous system. The mutational expansion of polyglutamine beyond a critical length produces a toxic gain of function in huntingtin and results in neuronal death. In the course of the disease, expanded huntingtin is proteolyzed, becomes abnormally folded, and accumulates in oligomers, fibrils, and microscopic inclusions. The aggregated forms of the expanded protein are structurally diverse. Structural heterogeneity may explain why polyglutamine-containing aggregates could paradoxically be either toxic or neuroprotective. When defined, the toxic structures could then specifically be targeted by prophylactic or therapeutic drugs aimed at inhibiting polyglutamine aggregation.

  19. ';Best' Practices for Aggregating Subset Results from Archived Datasets

    NASA Astrophysics Data System (ADS)

    Baskin, W. E.; Perez, J.

    2013-12-01

    In response to the exponential growth in science data analysis and visualization capabilities Data Centers have been developing new delivery mechanisms to package and deliver large volumes of aggregated subsets of archived data. New standards are evolving to help data providers and application programmers deal with growing needs of the science community. These standards evolve from the best practices gleaned from new products and capabilities. The NASA Atmospheric Sciences Data Center (ASDC) has developed and deployed production provider-specific search and subset web applications for the CALIPSO, CERES, TES, and MOPITT missions. This presentation explores several use cases that leverage aggregated subset results and examines the standards and formats ASDC developers applied to the delivered files as well as the implementation strategies for subsetting and processing the aggregated products. The following topics will be addressed: - Applications of NetCDF CF conventions to aggregated level 2 satellite subsets - Data-Provider-Specific format requirements vs. generalized standards - Organization of the file structure of aggregated NetCDF subset output - Global Attributes of individual subsetted files vs. aggregated results - Specific applications and framework used for subsetting and delivering derivative data files

  20. A multi-dimensional Structure-Activity Relationship of a protein in its aggregated states

    PubMed Central

    Wang, Lei; Schubert, David; Sawaya, Michael R.; Eisenberg, David; Riek, Roland

    2010-01-01

    Protein aggregates are both associated with disease and function. Because a variety of factors induce protein aggregation, a given protein can aggregate into different states. Here, we compare the structures and activities of five distinct protein aggregates of a single protein. Despite the diverse chemical, physical and biological treatments used to induce aggregation, all aggregate types contain the cross-β-sheet motif. However, they are structurally distinct, having different segments of the protein sequence involved in secondary structure formation. Because of these structural differences each aggregate has a unique set of properties. These include affinity to ATP, Thioflavin T, DNA, and membrane mimics, and interference with cell viability. The key to their multiple properties may be that the repetitive nature of the cross-β-sheet motif guarantees for many potent activities through cooperativity. The observed multidimensional structure-activity relationship of protein aggregates may be important for amyloid diseases but may also be advantageous in nanotechnology. PMID:20397175

  1. The ER Stress Surveillance (ERSU) pathway regulates daughter cell ER protein aggregate inheritance.

    PubMed

    Piña, Francisco J; Niwa, Maho

    2015-09-01

    Stress induced by cytoplasmic protein aggregates can have deleterious consequences for the cell, contributing to neurodegeneration and other diseases. Protein aggregates are also formed within the endoplasmic reticulum (ER), although the fate of ER protein aggregates, specifically during cell division, is not well understood. By simultaneous visualization of both the ER itself and ER protein aggregates, we found that ER protein aggregates that induce ER stress are retained in the mother cell by activation of the ER Stress Surveillance (ERSU) pathway, which prevents inheritance of stressed ER. In contrast, under conditions of normal ER inheritance, ER protein aggregates can enter the daughter cell. Thus, whereas cytoplasmic protein aggregates are retained in the mother cell to protect the functional capacity of daughter cells, the fate of ER protein aggregates is determined by whether or not they activate the ERSU pathway to impede transmission of the cortical ER during the cell cycle.

  2. Analyzing modifiers of protein aggregation in C. elegans by native agarose gel electrophoresis.

    PubMed

    Holmberg, Mats; Nollen, Ellen A A

    2013-01-01

    The accumulation of specific aggregation-prone proteins during aging is thought to be involved in several diseases, most notably Alzheimer's and Parkinson's disease as well as polyglutamine expansion disorders such as Huntington's disease. Caenorhabditis elegans disease models with transgenic expression of fluorescently tagged aggregation-prone proteins have been used to screen for genetic modifiers of aggregation. To establish the role of modifying factors in the generation of aggregation intermediates, a method has been developed using native agarose gel electrophoresis (NAGE) that enables parallel screening of aggregation patterns of fluorescently labeled aggregation-prone proteins. Together with microscopy-based genetic screens this method can be used to identify modifiers of protein aggregation and characterize their molecular function. Although described here for analyzing aggregates in C. elegans, NAGE can be adjusted for use in other model organisms as well as for cultured cells.

  3. Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

    PubMed Central

    Goodman, Candace K; Wolfenden, Mark L; Nangia-Makker, Pratima; Michel, Anna K; Raz, Avraham

    2014-01-01

    Summary Galectin-3 meditates cell surface glycoprotein clustering, cross linking, and lattice formation. In cancer biology, galectin-3 has been reported to play a role in aggregation processes that lead to tumor embolization and survival. Here, we show that lactose-functionalized dendrimers interact with galectin-3 in a multivalent fashion to form aggregates. The glycodendrimer–galectin aggregates were characterized by dynamic light scattering and fluorescence microscopy methodologies and were found to be discrete particles that increased in size as the dendrimer generation was increased. These results show that nucleated aggregation of galectin-3 can be regulated by the nucleating polymer and provide insights that improve the general understanding of the binding and function of sugar-binding proteins. PMID:25161713

  4. The nation’s top 25 construction aggregates producers

    USGS Publications Warehouse

    Willett, Jason C.

    2014-01-01

    U.S. production of construction aggregates in 2012 was 2.18 billion short tons valued at $17.6 billion, free on board (f.o.b.) at plant. In 2012, construction aggregates production remained virtually unchanged from the levels of the last two years because of a very slight increase compared with that of 2011 in the production of both construction sand and gravel and crushed stone. The average unit value, which is the f.o.b. at the plant price of a metric ton of material, increased slightly. Construction aggregates production was 36 percent less than and the associated value was 23 percent less than the record highs reported in 2006.

  5. Maximum Entropy Production As a Framework for Understanding How Living Systems Evolve, Organize and Function

    NASA Astrophysics Data System (ADS)

    Vallino, J. J.; Algar, C. K.; Huber, J. A.; Fernandez-Gonzalez, N.

    2014-12-01

    The maximum entropy production (MEP) principle holds that non equilibrium systems with sufficient degrees of freedom will likely be found in a state that maximizes entropy production or, analogously, maximizes potential energy destruction rate. The theory does not distinguish between abiotic or biotic systems; however, we will show that systems that can coordinate function over time and/or space can potentially dissipate more free energy than purely Markovian processes (such as fire or a rock rolling down a hill) that only maximize instantaneous entropy production. Biological systems have the ability to store useful information acquired via evolution and curated by natural selection in genomic sequences that allow them to execute temporal strategies and coordinate function over space. For example, circadian rhythms allow phototrophs to "predict" that sun light will return and can orchestrate metabolic machinery appropriately before sunrise, which not only gives them a competitive advantage, but also increases the total entropy production rate compared to systems that lack such anticipatory control. Similarly, coordination over space, such a quorum sensing in microbial biofilms, can increase acquisition of spatially distributed resources and free energy and thereby enhance entropy production. In this talk we will develop a modeling framework to describe microbial biogeochemistry based on the MEP conjecture constrained by information and resource availability. Results from model simulations will be compared to laboratory experiments to demonstrate the usefulness of the MEP approach.

  6. Measuring and modeling hemoglobin aggregation below the freezing temperature.

    PubMed

    Rosa, Mónica; Lopes, Carlos; Melo, Eduardo P; Singh, Satish K; Geraldes, Vitor; Rodrigues, Miguel A

    2013-08-01

    Freezing of protein solutions is required for many applications such as storage, transport, or lyophilization; however, freezing has inherent risks for protein integrity. It is difficult to study protein stability below the freezing temperature because phase separation constrains solute concentration in solution. In this work, we developed an isochoric method to study protein aggregation in solutions at -5, -10, -15, and -20 °C. Lowering the temperature below the freezing point in a fixed volume prevents the aqueous solution from freezing, as pressure rises until equilibrium (P,T) is reached. Aggregation rates of bovine hemoglobin (BHb) increased at lower temperature (-20 °C) and higher BHb concentration. However, the addition of sucrose substantially decreased the aggregation rate and prevented aggregation when the concentration reached 300 g/L. The unfolding thermodynamics of BHb was studied using fluorescence, and the fraction of unfolded protein as a function of temperature was determined. A mathematical model was applied to describe BHb aggregation below the freezing temperature. This model was able to predict the aggregation curves for various storage temperatures and initial concentrations of BHb. The aggregation mechanism was revealed to be mediated by an unfolded state, followed by a fast growth of aggregates that readily precipitate. The aggregation kinetics increased for lower temperature because of the higher fraction of unfolded BHb closer to the cold denaturation temperature. Overall, the results obtained herein suggest that the isochoric method could provide a relatively simple approach to obtain fundamental thermodynamic information about the protein and the aggregation mechanism, thus providing a new approach to developing accelerated formulation studies below the freezing temperature.

  7. Fire effects on soil aggregation: A review

    NASA Astrophysics Data System (ADS)

    Mataix-Solera, J.; Cerdà, A.; Arcenegui, V.; Jordán, A.; Zavala, L. M.

    2011-11-01

    Fire can affect soil properties depending on a number of factors including fire severity and soil type. Aggregate stability (AS) refers to soil structure resilience in response to external mechanical forces. Many authors consider soil aggregation to be a parameter reflecting soil health, as it depends on chemical, physical and biological factors. The response of AS to forest fires is complex, since it depends on how fire has affected other related properties such as organic matter content, soil microbiology, water repellency and soil mineralogy. Opinions differ concerning the effect of fire on AS. Some authors have observed a decrease in AS in soils affected by intense wildfire or severe laboratory heating. However, others have reported increases. We provide an up to date review of the research on this topic and an analysis of the causes for the different effects observed. The implications for soil system functioning and for the hydrology of the affected areas are also discussed. Generally, low severity fires do not produce notable changes in AS, although in some cases an increase has been observed and attributed to increased water repellency. In contrast, high severity fires can induce important changes in this property, but with different effects depending on the type of soil affected. The patterns observed can vary from a disaggregation as a consequence of the organic matter destruction, to a strong aggregation if a recrystallization of some minerals such as Fe and Al oxyhydroxides occurs when they are present in sufficient quantities in the soil, after exposure to high temperatures. Because of the complexity of the different possible effects and reasons for the potential changes in the fire-affected soil aggregates, the inclusion of other parameters in the studies is necessary to understand the results. The suggested parameters to include in the examination of AS are: soil organic matter, microbial biomass, water repellency, texture, aggregate size distribution

  8. Nonsinglet kaon fragmentation function from e{sup +}e{sup -} kaon production

    SciTech Connect

    Albino, Simon; Christova, Ekaterina

    2010-05-01

    We perform fits to the available charged and neutral kaon-production data in e{sup +}+e{sup -{yields}}K+X, K=K{sup {+-},} and K{sub S}{sup 0}, and determine the nonsinglet combination of kaon fragmentation functions D{sub u}{sup K{+-}-}D{sub d}{sup K{+-}}in a model independent way and without any correlations to the other fragmentation functions. Only nuclear isospin invariance is assumed. Working with nonsinglets allows us to include the data at very low momentum fractions, which have so far been excluded in global fits, and to perform a first next-next-to leading order fit to fragmentation functions. We find that the kaon nonsinglet fragmentation function at large z is larger than that obtained by the other collaborations from global fit analysis and differs significantly at low z.

  9. Process Dependent Sivers Function and Implication for Single Spin Asymmetry in Inclusive Hadron Production

    SciTech Connect

    Leonard Gamberg, Zhong-Bo Kang

    2011-01-01

    We study the single transverse spin asymmetries in the single inclusive particle production within the framework of the generalized parton model (GPM). By carefully analyzing the initial- and final-state interactions, we include the process-dependence of the Sivers functions into the GPM formalism. The modified GPM formalism has a close connection with the collinear twist-3 approach. Within the new formalism, we make predictions for inclusive {pi}{sup 0} and direct photon productions at RHIC energies. We find the predictions are opposite to those in the conventional GPM approach.

  10. Design of Road Pavement Using Recycled Aggregate

    NASA Astrophysics Data System (ADS)

    Remišová, Eva; Decký, Martin; Mikolaš, Milan; Hájek, Matej; Kovalčík, Luboš; Mečár, Martin

    2016-10-01

    The presented article gives special attention to codified clauses of the road construction law, the relevant clauses of t