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Sample records for aggregate production function

  1. 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.

  2. Production of prone-to-aggregate proteins.

    PubMed

    Lebendiker, Mario; Danieli, Tsafi

    2014-01-21

    Expression of recombinant proteins in Escherichia coli (E. coli) remains the most popular and cost-effective method for producing proteins in basic research and for pharmaceutical applications. Despite accumulating experience and methodologies developed over the years, production of recombinant proteins prone to aggregate in E. coli-based systems poses a major challenge in most research applications. The challenge of manufacturing these proteins for pharmaceutical applications is even greater. This review will discuss effective methods to reduce and even prevent the formation of aggregates in the course of recombinant protein production. We will focus on important steps along the production path, which include cloning, expression, purification, concentration, and storage. PMID:24211444

  3. 21 CFR 1303.13 - Adjustments of aggregate production quotas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Federal Register his final order determining the aggregate production for the basic class of controlled... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Adjustments of aggregate production quotas. 1303... Aggregate Production and Procurement Quotas § 1303.13 Adjustments of aggregate production quotas. (a)...

  4. 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...

  5. Aggregated Authentication (AMAC) Using Universal Hash Functions

    NASA Astrophysics Data System (ADS)

    Znaidi, Wassim; Minier, Marine; Lauradoux, Cédric

    Aggregation is a very important issue to reduce the energy consumption in Wireless Sensors Networks (WSNs). There is currently a lack of cryptographic primitives for authentication of aggregated data. The theoretical background for Aggregated Message Authentication Codes (AMACs) has been proposed by Chan and Castelluccia at ISIT 08.

  6. Across species-pool aggregation alters grassland productivity and diversity.

    PubMed

    McKenna, Thomas P; Yurkonis, Kathryn A

    2016-08-01

    Plant performance is determined by the balance of intra- and interspecific neighbors within an individual's zone of influence. If individuals interact over smaller scales than the scales at which communities are measured, then altering neighborhood interactions may fundamentally affect community responses. These interactions can be altered by changing the number (species richness), abundances (species evenness), and positions (species pattern) of the resident plant species, and we aimed to test whether aggregating species at planting would alter effects of species richness and evenness on biomass production at a common scale of observation in grasslands. We varied plant species richness (2, 4, or 8 species and monocultures), evenness (0.64, 0.8, or 1.0), and pattern (planted randomly or aggregated in groups of four individuals) within 1 × 1 m plots established with transplants from a pool of 16 tallgrass prairie species and assessed plot-scale biomass production and diversity over the first three growing seasons. As expected, more species-rich plots produced more biomass by the end of the third growing season, an effect associated with a shift from selection to complementarity effects over time. Aggregating conspecifics at a 0.25-m scale marginally reduced biomass production across all treatments and increased diversity in the most even plots, but did not alter biodiversity effects or richness-productivity relationships. Results support the hypothesis that fine-scale species aggregation affects diversity by promoting species coexistence in this system. However, results indicate that inherent changes in species neighborhood relationships along grassland diversity gradients may only minimally affect community (meter) - scale responses among similarly designed biodiversity-ecosystem function studies. Given that species varied in their responses to local aggregation, it may be possible to use such species-specific results to spatially design larger-scale grassland

  7. 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.

  8. 21 CFR 1303.11 - Aggregate production quotas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Aggregate production quotas. 1303.11 Section 1303.11 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE QUOTAS Aggregate Production... manufacturing and for inventory purposes, yield and stability problems, potential disruptions to...

  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. Aggregation kinetics and colloidal stability of functionalized nanoparticles.

    PubMed

    Gambinossi, Filippo; Mylon, Steven E; Ferri, James K

    2015-08-01

    The functionalization of nanoparticles has primarily been used as a means to impart stability in nanoparticle suspensions. In most cases even the most advanced nanomaterials lose their function should suspensions aggregate and settle, but with the capping agents designed for specific solution chemistries, functionalized nanomaterials generally remain monodisperse in order to maintain their function. The importance of this cannot be underestimated in light of the growing use of functionalized nanomaterials for wide range of applications. Advanced functionalization schemes seek to exert fine control over suspension stability with small adjustments to a single, controllable variable. This review is specific to functionalized nanoparticles and highlights the synthesis and attachment of novel functionalization schemes whose design is meant to affect controllable aggregation. Some examples of these materials include stimulus responsive polymers for functionalization which rely on a bulk solution physicochemical threshold (temperature or pH) to transition from a stable (monodisperse) to aggregated state. Also discussed herein are the primary methods for measuring the kinetics of particle aggregation and theoretical descriptions of conventional and novel models which have demonstrated the most promise for the appropriate reduction of experimental data. Also highlighted are the additional factors that control nanoparticle stability such as the core composition, surface chemistry and solution condition. For completeness, a case study of gold nanoparticles functionalized using homologous block copolymers is discussed to demonstrate fine control over the aggregation state of this type of material. PMID:25150615

  11. 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...

  12. 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...

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

    PubMed

    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

  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. PMID:25188783

  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, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 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. Hydration and diffusion dynamics shape microbial community composition and function in soil aggregates.

    NASA Astrophysics Data System (ADS)

    Or, D.; Ebrahimi, A.

    2014-12-01

    Natural variations in soil hydration conditions (rainfall, evaporation, root water uptake) affect gas and nutrient diffusion and soil microbial community composition and function. The conditions in soil aggregates are of particular interest due to limitations to oxygen diffusion into the core often containing organic carbon (as aggregation agent). The constantly varying soil hydration conditions affect the spatial extent of anoxic conditions in aggregates and thus the sized and self-organization of aerobic and anaerobic microbial communities. We developed an artificial soil aggregate composed of 3-D angular pore network combined with individual based models of motile microbial cells that grow, move, intercept nutrients and are inhibited by presence or absence of oxygen. The hydration conditions in the model aggregate affect community size, spatial segregation, and growth rates. The opposing diffusion directions of oxygen and carbon were essential to maintenance of aerobic and anaerobic communities within an aggregate (anaerobes become extinct when carbon sources are external). Cohabited soil aggregates promoted onset of anaerobic conditions by oxygen consumption by peripheral aerobes. Model predictions of CO2 and N2O production rates were in good agreement with experimental data. Results illustrate how aerobic and anaerobic microbial communities are activated by certain hydration conditions that enhance either nitrogen losses or decomposition of organic matter both contributing to GHG emissions.

  2. Platelet aggregation test

    MedlinePlus

    The platelet aggregation blood test checks how well platelets , a part of blood, clump together and cause blood to clot. ... Decreased platelet aggregation may be due to: Autoimmune ... Fibrin degradation products Inherited platelet function defects ...

  3. 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.

  4. 76 FR 77016 - Controlled Substances: Final Adjusted Aggregate Production Quotas for 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... aggregate production quotas for controlled substances in Schedules I and II (75 FR 79404). That notice... 1303 of Title 21 of the Code of Federal Regulations.'' 76 FR 11077. Aggregate production quotas for... adjusted 2011 aggregate production quotas for these substances as published on September 14, 2011, at 76...

  5. Production of aggregate from non-metallic automotive shredder residues.

    PubMed

    Rossetti, Vito Alunno; Di Palma, Luca; Medici, Franco

    2006-09-21

    In this paper, the results of an experimentation on the production of granules suitable to be used as aggregates in cementitious or asphalt mixes are presented and discussed. The granules were obtained by granulating the non-metallic fraction of automotive shredder residues. In a preliminary separation step the fluff fraction containing mainly inert and non-metallic materials was sieved and analyzed for the metal content. In the following granulation step, the sieved fraction was mixed with binding materials, fly ash and a densifier agent, to produce granules of 5-30 mm of diameter and up to 1400 kg/m3 of specific weight. The granulation was carried out at room temperature in a rotating tank. Concrete samples prepared using as aggregates the produced granules showed a specific weight up to 1800 kg/m3 and a compressive strength up to about 55% of reference samples prepared using a calcareous aggregate, depending on the fluff content of the mixes, and on the nature of the binder and of the other components used. PMID:16647811

  6. An acetylation switch controls TDP-43 function and aggregation propensity.

    PubMed

    Cohen, Todd J; Hwang, Andrew W; Restrepo, Clark R; Yuan, Chao-Xing; Trojanowski, John Q; Lee, Virginia M Y

    2015-01-01

    TDP-43 pathology is a disease hallmark that characterizes amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP). Although a critical role for TDP-43 as an RNA-binding protein has emerged, the regulation of TDP-43 function is poorly understood. Here, we identify lysine acetylation as a novel post-translational modification controlling TDP-43 function and aggregation. We provide evidence that TDP-43 acetylation impairs RNA binding and promotes accumulation of insoluble, hyper-phosphorylated TDP-43 species that largely resemble pathological inclusions in ALS and FTLD-TDP. Moreover, biochemical and cell-based assays identify oxidative stress as a signalling cue that promotes acetylated TDP-43 aggregates that are readily engaged by the cellular defense machinery. Importantly, acetylated TDP-43 lesions are found in ALS patient spinal cord, indicating that aberrant TDP-43 acetylation and loss of RNA binding are linked to TDP-43 proteinopathy. Thus, modulating TDP-43 acetylation represents a plausible strategy to fine-tune TDP-43 activity, which could provide new therapeutic avenues for TDP-43 proteinopathies. PMID:25556531

  7. An acetylation switch controls TDP-43 function and aggregation propensity

    PubMed Central

    Cohen, Todd J.; Hwang, Andrew W.; Restrepo, Clark R.; Yuan, Chao-Xing; Trojanowski, John Q.; Lee, Virginia M.Y.

    2015-01-01

    TDP-43 pathology is a disease hallmark that characterizes amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP). Although a critical role for TDP-43 as an RNA-binding protein has emerged, the regulation of TDP-43 function is poorly understood. Here we identify lysine acetylation as a novel post-translational modification controlling TDP-43 function and aggregation. We provide evidence that TDP-43 acetylation impairs RNA-binding and promotes accumulation of insoluble, hyper-phosphorylated TDP-43 species that largely resemble pathological inclusions in ALS and FTLD-TDP. Moreover, biochemical and cell-based assays identify oxidative stress as a signaling cue that promotes acetylated TDP-43 aggregates that are readily engaged by the cellular defense machinery. Importantly, acetylated TDP-43 lesions are found in ALS patient spinal cord, indicating that aberrant TDP-43 acetylation and loss of RNA binding are linked to TDP-43 proteinopathy. Thus, modulating TDP-43 acetylation represents a plausible strategy to fine-tune TDP-43 activity, which could provide new therapeutic avenues for TDP-43 proteinopathies. PMID:25556531

  8. 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.

  9. 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

  10. 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

  11. 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).

  12. Hydration and diffusion processes shape microbial community organization and function in model soil aggregates

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Ali; Or, Dani

    2015-12-01

    The constantly changing soil hydration status affects gas and nutrient diffusion through soil pores and thus the functioning of soil microbial communities. The conditions within soil aggregates are of particular interest due to limitations to oxygen diffusion into their core, and the presence of organic carbon often acting as binding agent. We developed a model for microbial life in simulated soil aggregates comprising of 3-D angular pore network model (APNM) that mimics soil hydraulic and transport properties. Within these APNM, we introduced individual motile (flagellated) microbial cells with different physiological traits that grow, disperse, and respond to local nutrients and oxygen concentrations. The model quantifies the dynamics and spatial extent of anoxic regions that vary with hydration conditions, and their role in shaping microbial community size and activity and the spatial (self) segregation of anaerobes and aerobes. Internal carbon source and opposing diffusion directions of oxygen and carbon within an aggregate were essential to emergence of stable coexistence of aerobic and anaerobic communities (anaerobes become extinct when carbon sources are external). The model illustrates a range of hydration conditions that promote or suppress denitrification or decomposition of organic matter and thus affect soil GHG emissions. Model predictions of CO2 and N2O production rates were in good agreement with limited experimental data. These limited tests support the dynamic modeling approach whereby microbial community size, composition, and spatial arrangement emerge from internal interactions within soil aggregates. The upscaling of the results to a population of aggregates of different sizes embedded in a soil profile is underway.

  13. Diatom aggregation and dimethylsulfide production in phytoplankton blooms

    SciTech Connect

    Crocker, K.M.

    1994-01-01

    Phytoplankton blooms are crucial links in many of the earth's biogeochemical cycles. Blooms take up atmospheric carbon through photosynthesis, and sequester it on the ocean floor by sinking. Aggregation of single cells into [open quote]marine snow[close quote] particles speeds up the sinking of algal cells. Laboratory studies investigating the process of aggregation show that some species have a higher probability of aggregating than others, and that there exist several mechanisms for causing aggregation. Field studies confirm that some species are more likely to be found in aggregates than in the surrounding seawater. High latitude Premnesiophyte blooms are found to produce large amounts of dimethylsulflde (DMS), believed to be an important chemical in global thermoregulation. DMS is found to vary diurnally, possibly due to photooxidation by ultraviolet light. This possibility links the effects of DMS on cloud formation with the effects of increased ultraviolet light penetrating the earths ozone layer.

  14. 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. PMID:23657436

  15. A delicate balance between functionally required flexibility and aggregation risk in a β-rich protein

    PubMed Central

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

    2014-01-01

    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. PMID:24236614

  16. 78 FR 48193 - Final Adjusted Aggregate Production Quotas for Schedule I and II Controlled Substances and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ...This notice establishes final adjusted 2013 aggregate production quotas for controlled substances in Schedules I and II of the Controlled Substances Act (CSA) and assessment of annual needs for the List I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine, as well as the 2013 aggregate production quotas for three recently temporarily controlled...

  17. 75 FR 79404 - Controlled Substances: Established Initial Aggregate Production Quotas for 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... schedules I and II was published in the Federal Register (75 FR 56137). All interested persons were invited... Enforcement Administration Controlled Substances: Established Initial Aggregate Production Quotas for 2011 AGENCY: Drug Enforcement Administration (DEA), Justice. ACTION: Notice of aggregate production quotas...

  18. 78 FR 40186 - Proposed Aggregate Production Quotas for Schedule I and II Controlled Substances and Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ... described in the 2010 and 2011 assessment of annual needs (74 FR 60294 and 75 FR 79407, respectively). DEA... phenylpropanolamine, expressed in grams of anhydrous acid or base, be established as follows: Proposed 2014 Basic... aggregate production quotas, and certain Schedule I aggregate production quotas (gamma-hydroxybutyric...

  19. 75 FR 35838 - Controlled Substances: Proposed Revised Aggregate Production Quotas for 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... FR 54080) on October 21, 2010. The proposed revised 2010 aggregate production quotas represent those... for certain controlled substances in schedules I and II was published in the Federal Register (74 FR... Enforcement Administration Controlled Substances: Proposed Revised Aggregate Production Quotas for 2010...

  20. 76 FR 78044 - Controlled Substances: Established Aggregate Production Quotas for 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... Federal Register (76 FR 65537). That notice proposed the 2012 aggregate production quotas for each basic... pursuant to the final order also published on October 21, 2011, at 76 FR 65371. No comments were received... Enforcement Administration Controlled Substances: Established Aggregate Production Quotas for 2012...

  1. 77 FR 39737 - Controlled Substances: Proposed Adjustment to the Aggregate Production Quotas for 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... published in the Federal Register (76 FR 78044) on December 15, 2011. That notice stipulated that, as... Enforcement Administration Controlled Substances: Proposed Adjustment to the Aggregate Production Quotas for... for comments. SUMMARY: This notice proposes to adjust the 2012 aggregate production quotas for...

  2. Hydroxychavicol, a novel betel leaf component, inhibits platelet aggregation by suppression of cyclooxygenase, thromboxane production and calcium mobilization

    PubMed Central

    Chang, M C; Uang, B J; Tsai, C Y; Wu, H L; Lin, B R; Lee, C S; Chen, Y J; Chang, C H; Tsai, Y L; Kao, C J; Jeng, J H

    2007-01-01

    Background and purpose: Platelet hyperactivity is important in the pathogenesis of cardiovascular diseases. Betel leaf (PBL) is consumed by 200-600 million betel quid chewers in the world. Hydroxychavicol (HC), a betel leaf component, was tested for its antiplatelet effect. Experimental approach: We tested the effect of HC on platelet aggregation, thromboxane B2 (TXB2) and reactive oxygen species (ROS) production, cyclooxygenase (COX) activity, ex vivo platelet aggregation and mouse bleeding time and platelet plug formation in vivo. The pharmacokinetics of HC in rats was also assessed. Key results: HC inhibited arachidonic acid (AA) and collagen-induced platelet aggregation and TXB2 production. HC inhibited the thrombin-induced TXB2 production, but not platelet aggregation. SQ29548, suppressed collagen- and thrombin-induced TXB2 production, but not thrombin-induced platelet aggregation. HC also suppressed COX-1/COX-2 enzyme activity and the AA-induced ROS production and Ca2+ mobilization. HC further inhibited the ex vivo platelet aggregation of platelet-rich plasma (>100 nmole/mouse) and prolonged platelet plug formation (>300 nmole/mouse) in mesenteric microvessels, but showed little effect on bleeding time in mouse tail. Moreover, pharmacokinetics analysis found that more than 99% of HC was metabolized within 3 min of administration in Sprague-Dawley rats in vivo. Conclusions and implications: HC is a potent COX-1/COX-2 inhibitor, ROS scavenger and inhibits platelet calcium signaling, TXB2 production and aggregation. HC could be a potential therapeutic agent for prevention and treatment of atherosclerosis and other cardiovascular diseases through its anti-inflammatory and antiplatelet effects, without effects on haemostatic functions. PMID:17641677

  3. 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. PMID:19577916

  4. 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

  5. Carbon availability structures microbial community composition and function in soil aggregate fractions

    NASA Astrophysics Data System (ADS)

    Hofmockel, K. S.; Bach, E.; Williams, R.; Howe, A.

    2014-12-01

    Identifying the microbial metabolic pathways that most strongly influence ecosystem carbon (C) cycling requires a deeper understanding of the availability and accessibility of microbial substrates. A first step towards this goal is characterizing the relationships between microbial community function and soil C chemistry in a field context. For this perspective, soil aggregate fractions can be used as model systems that scale between microbe-substrate interactions and ecosystem C cycling and storage. The present study addresses how physicochemical variation among soil aggregate fractions influences the composition and functional potential of C cycling microbial communities. We report variation across soil aggregates using plot scale biological replicates from biofuel agroecosystems (fertilized, reconstructed, tallgrass prairie). Our results suggest that C and nitrogen (N) chemistry significantly differ among aggregate fractions. This leads to variation in microbial community composition, which was better characterized among aggregates than by using the whole soil. In fact by considering soil aggregation, we were able to characterize almost 2000 more taxa than whole soil alone, resulting in 65% greater community richness. Availability of C and N strongly influenced the composition of microbial communities among soil aggregate fractions. The normalized abundance of microbial functional guilds among aggregate fractions correlated with C and N chemistry, as did functional potential, measured by extracellular enzyme activity. Metagenomic results suggest that soil aggregate fractions select for functionally distinct microbial communities, which may significantly influence decomposition and soil C storage. Our study provides support for the premise that integration of soil aggregate chemistry, especially microaggregates that have greater microbial richness and occur at spatial scales relevant to microbial community functioning, may be necessary to understand the role of

  6. Compaction, Fusion, and Functional Activation of Three-Dimensional Human Mesenchymal Stem Cell Aggregate

    PubMed Central

    Tsai, Ang-Chen; Liu, Yijun; Yuan, Xuegang

    2015-01-01

    Human mesenchymal stem cells (hMSCs) are primary candidates in cell therapy and tissue engineering and are being tested in clinical trials for a wide range of diseases. Originally isolated and expanded as plastic adherent cells, hMSCs have intriguing properties of in vitro self-assembly into three-dimensional (3D) aggregates that improve a range of biological properties, including multilineage potential, secretion of therapeutic factors, and resistance against ischemic condition. While cell–cell contacts and cell–extracellular matrix interactions mediate 3D cell aggregation, the adaptive changes of hMSC cytoskeleton during self-assembly and associated metabolic reconfiguration may also influence aggregate properties and functional activation. In this study, we investigated the role of actin in regulating 3D hMSC aggregate compaction, fusion, spreading and functional activation. Individual hMSC aggregates with controlled initial cell number were formed by seeding a known number of hMSCs (500, 2000, and 5000 cells/well) in multi-well plates of an ultra-low adherent surface to form multicellular aggregates in individual wells. To assess the influence of actin-mediated contractility on hMSC aggregation and properties, actin modulators, including cytochalasin D (cytoD), nocodazole, lysophosphatidic acid (LPA), and Y-27632, were added at different stages of aggregation and their impacts on hMSC aggregate compaction and apoptosis were monitored. The results suggest that actin-mediated contractility influences hMSC aggregation, compaction, fusion, and spreading on adherent surface. Formation of multi-cellular aggregates significantly upregulated caspase 3/7 expression, expression of C-X-C chemokine receptor type 4 (CXCR-4), cell migration, secretion of prostaglandin E2 (PGE-2) and interleukin 6 (IL-6), and resistance to in vitro ischemic stress. The functional enhancement, however, is dependent on caspase activation, because treatment with Q-VD-OPh, a pan

  7. Sensitivity of power functions to aggregation: Bias and uncertainty in radar rainfall retrieval

    NASA Astrophysics Data System (ADS)

    Sassi, M. G.; Leijnse, H.; Uijlenhoet, R.

    2014-10-01

    Rainfall retrieval using weather radar relies on power functions between radar reflectivity Z and rain rate R. The nonlinear nature of these relations complicates the comparison of rainfall estimates employing reflectivities measured at different scales. Transforming Z into R using relations that have been derived for other scales results in a bias and added uncertainty. We investigate the sensitivity of Z-R relations to spatial and temporal aggregation using high-resolution reflectivity fields for five rainfall events. Existing Z-R relations were employed to investigate the behavior of aggregated Z-R relations with scale, the aggregation bias, and the variability of the estimated rain rate. The prefactor and the exponent of aggregated Z-R relations systematically diverge with scale, showing a break that is event-dependent in the temporal domain and nearly constant in space. The systematic error associated with the aggregation bias at a given scale can become of the same order as the corresponding random error associated with intermittent sampling. The bias can be constrained by including information about the variability of Z within a certain scale of aggregation, and is largely captured by simple functions of the coefficient of variation of Z. Several descriptors of spatial and temporal variability of the reflectivity field are presented, to establish the links between variability descriptors and resulting aggregation bias. Prefactors in Z-R relations can be related to multifractal properties of the rainfall field. We find evidence of scaling breaks in the structural analysis of spatial rainfall with aggregation.

  8. New Mexico aggregate production sites, 1997-1999

    USGS Publications Warehouse

    Orris, Greta J.

    2000-01-01

    This report presents data, including latitude and longitude, for aggregate sites in New Mexico that were believed to be active in the period 1997-1999. The data are presented in paper form in Part A of this report and as Microsoft Excel 97 and Data Interchange Format (DIF) files in Part B. The work was undertaken as part of the effort to update information for the National Atlas. This compilation includes data from: the files of U.S. Geological Survey (USGS); company contacts; the New Mexico Bureau of Mines and Mineral Resources, New Mexico Bureau of Mine Inspection, and the Mining and Minerals Division of the New Mexico Energy, Minerals and Natural Resources Department (Hatton and others, 1998); the Bureau of Land Management Information; and direct communications with some of the aggregate operators. Additional information on most of the sites is available in Hatton and others (1998).

  9. PRODUCTION OF CONSTRUCTION AGGREGATES FROM FLUE GAS DESULFURIZATION SLUDGE

    SciTech Connect

    1998-12-01

    Through a cooperative agreement with DOE, the Research and Development Department of CONSOL Inc. (CONSOL R and D) is teaming with SynAggs, Inc. and Duquesne Light to design, construct, and operate a 500 lb/h continuous pilot plant to produce road construction aggregate from a mixture of wet flue gas desulfurization (FGD) sludge, fly ash, and other components. The proposed project is divided into six tasks: (1) Project Management; (2) Mix Design Evaluation; (3) Process Design; (4) Construction; (5) Start-Up and Operation; and (6) Reporting. In this quarter, Tasks 1 and 2 were completed. A project management plan (Task 1) was issued to DOE on October 22, 1998 . The mix design evaluation (Task 2) with Duquesne Light Elrama Station FGD sludge and Allegheny Power Hatfields Ferry Station fly ash was completed. Eight semi-continuous bench-scale tests were conducted to examine the effects of mix formulation on aggregate properties. A suitable mix formulation was identified to produce aggregates that meet specifications of the American Association of State High Transport Officials (AASHTO) as Class A aggregate for use in highway construction. The mix formulation was used in designing the flow sheet of the pilot plant. The process design (Task 3) is approximately 80% completed. Equipment was evaluated to comply with design requirements. The design for the curing vessel was completed by an outside engineering firm. All major equipment items for the pilot plant, except the curing vessel, were ordered. Pilot plant construction (Task 4) was begun in October. The Hazardous Substance Plan was issued to DOE. The Allegheny County (PA) Heat Department determined that an air emission permit is not required for operation of the pilot plant.

  10. USING A MINERAL AGGREGATE TO SUPPLY PHOSPHORUS AND POTASSIUM FOR CONTAINERIZED CROP PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a rising need for increased water and nutrient use efficiency in ornamental container production to maximize profits while minimizing environmental impact. Substrates containing industrial mineral aggregates (clay) can increase water use efficiency and reduce phosphate leaching while retain...

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

    PubMed

    Hou, Wen-Che; He, Chen-Jing; Wang, Yi-Sheng; Wang, David K; Zepp, Richard G

    2016-04-01

    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 applications. In this study, we examined the phototransformation of carboxylated SWCNTs and associated amorphous carbon impurities in the presence or absence of H2O2 under simulated sunlight conditions. We found that while carboxylated SWCNTs were rather unreactive with respect to direct solar photolysis, they photoreacted in the presence of H2O2, forming CO2 and strongly aggregated SWCNT products that precipitated. Photoreaction caused SWCNTs to lose oxygen-containing functionalities, and interestingly, the resulting photoproducts had spectral characteristics similar to those of parent carboxylated SWCNTs whose amorphous carbon was removed by base washing. These results indicated that photoreaction of the amorphous carbon was likely involved. The removal of amorphous carbon after indirect photoreaction was confirmed with thermogravimetric analysis (TGA). Further studies using carboxylated SWCNTs with and without base washing indicate that amorphous carbon reduced the extent of aggregation caused by photoreaction. The second-order rate constant for carboxylated SWCNTs reacting with (•)OH was estimated to be in the range of 1.7-3.8 × 10(9) MC(-1) s(-1). The modeled phototransformation half-lives fall in the range of 2.8-280 days in typical sunlit freshwaters. Our study indicates that photosensitized reactions involving (•)OH may be a transformation and removal pathway of functionalized SWCNTs in the aquatic environment, and that the residual amorphous carbon associated with SWCNTs plays a role in SWCNT stabilization. PMID:26928260

  12. Valorization of lignite combustion residues and ferroalumina in the production of aggregates.

    PubMed

    Anagnostopoulos, I M; Stivanakis, V E; Angelopoulos, G N; Papamantellos, D C

    2010-02-15

    The present research study investigates the synergy of industrial solid by-products from lignite combustion (fly ash and bottom ash) and aluminum production (ferroalumina) in the production of lightweight aggregates (LWA). The process consists of two stages, pelletization and sintering. Bottom ash (BA) is used as the principal raw material in mixtures while ferroalumina (FAL) is added in lower percentages (5-30 wt%). BA carbon content is used as the fuel of sintering process in high temperatures, around 1250 degrees C, and gas generation is responsible for porous structure formation. Physical properties such as porosity, water absorption and bulk density, of sintering products are measured. Increase of FAL percentage in sintering mixtures results in decrease of porosity from 61% to 35% and of water absorption from 61% to 21% and in increase of bulk density from 1.02 g/cm(3) to 1.80 g/cm(3) of the produced aggregates. Aggregates produced by FAL addition up to 20 wt% are characterized as LWA. Aggregates formed are used in the production of concrete specimens. Compressive strength of concrete increases by increasing FAL addition in aggregates from 5 wt% to 15 wt% (highest strength value), while decrease by increasing FAL addition from 20 wt% to 30 wt%. FAL addition in lignite ashes sintering mixtures (up to 15 wt%) is considered as an important parameter for enhancing aggregates strength. PMID:19850411

  13. 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.

  14. Comparison of antibody molecules produced from two cell lines with contrasting productivities and aggregate contents.

    PubMed

    Ishii, Yoichi; Imamoto, Yasufumi; Yamamoto, Rie; Tsukahara, Masayoshi; Wakamatsu, Kaori

    2015-01-01

    Cell culture processes that produce therapeutic antibodies with high productivity (titer) and low aggregate content reduce the risk of adverse effects and expense to patients. To elucidate the mechanism of aggregate formation, we compared trastuzumab samples produced from two contrasting cell lines: cell line A, which exhibits high titer and low aggregate content, and cell line B, which exhibits low titer and high aggregate content. Cell line B produced significantly fewer (approximately 1/3) antibodies compared with cell line A and contained higher (approximately 3-fold) percentages of aggregates. The aggregates of antibodies found in the protein A-purified samples of cell line B were associated mostly with noncovalent interactions. Cell line B exhibited a low content of monomers/dimers of light chains in the medium and within cells. Because light chains are essential for the correct folding of heavy chains and secretion of mature antibodies, the characteristics of cell line B may be attributed to low levels of light chain production. In addition, protein A-purified antibodies from cell line B (but not those from cell line A) contained fragments that are expected to expose the hydrophobic CH3 domain, which may serve as nuclei for aggregation. PMID:25501618

  15. Method for the production of cementitious compositions and aggregate derivatives from said compositions

    DOEpatents

    Minnick, L. John

    1981-01-01

    Method for the production of cementitious compositions and aggregate derivatives of said compositions, and cementitious compositions and aggregates produced by said method, wherein fluidized bed combustion residue and pozzolanic material, such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix. The mix is cast into desired shape and cured. If desired, the shape may then be crushed so as to result in a fluidized bed combustion residue-fly ash aggregate material or the shape may be used by itself.

  16. Aggregation Pattern Transitions by Slightly Varying the Attractive/Repulsive Function

    PubMed Central

    Cheng, Zhao; Zhang, Hai-Tao; Chen, Michael Z. Q.; Zhou, Tao; Valeyev, Najl V.

    2011-01-01

    Among collective behaviors of biological swarms and flocks, the attractive/repulsive (A/R) functional links between particles play an important role. By slightly changing the cutoff distance of the A/R function, a drastic transition between two distinct aggregation patterns is observed. More precisely, a large cutoff distance yields a liquid-like aggregation pattern where the particle density decreases monotonously from the inside to the outwards within each aggregated cluster. Conversely, a small cutoff distance produces a crystal-like aggregation pattern where the distance between each pair of neighboring particles remains constant. Significantly, there is an obvious spinodal in the variance curve of the inter-particle distances along the increasing cutoff distances, implying a legible transition pattern between the liquid-like and crystal-like aggregations. This work bridges the aggregation phenomena of physical particles and swarming of organisms in nature upon revealing some common mechanism behind them by slightly varying their inter-individual attractive/repulsive functions, and may find its potential engineering applications, for example, in the formation design of multi-robot systems and unmanned aerial vehicles (UAVs). PMID:21799776

  17. Exploring New Biological Functions of Amyloids: Bacteria Cell Agglutination Mediated by Host Protein Aggregation

    PubMed Central

    Torrent, Marc; Pulido, David; Nogués, M. Victòria; Boix, Ester

    2012-01-01

    Antimicrobial proteins and peptides (AMPs) are important effectors of the innate immune system that play a vital role in the prevention of infections. Recent advances have highlighted the similarity between AMPs and amyloid proteins. Using the Eosinophil Cationic Protein as a model, we have rationalized the structure-activity relationships between amyloid aggregation and antimicrobial activity. Our results show how protein aggregation can induce bacteria agglutination and cell death. Using confocal and total internal reflection fluorescence microscopy we have tracked the formation in situ of protein amyloid-like aggregates at the bacteria surface and on membrane models. In both cases, fibrillar aggregates able to bind to amyloid diagnostic dyes were detected. Additionally, a single point mutation (Ile13 to Ala) can suppress the protein amyloid behavior, abolishing the agglutinating activity and impairing the antimicrobial action. The mutant is also defective in triggering both leakage and lipid vesicle aggregation. We conclude that ECP aggregation at the bacterial surface is essential for its cytotoxicity. Hence, we propose here a new prospective biological function for amyloid-like aggregates with potential biological relevance. PMID:23133388

  18. 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.

  19. Difference in aggregation between functional and toxic amyloids studied by atomistic simulations

    NASA Astrophysics Data System (ADS)

    Carballo Pacheco, Martin; Ismail, Ahmed E.; Strodel, Birgit

    Amyloids are highly structured protein aggregates, normally associated with neurodegenerative diseases such as Alzheimer's disease. In recent years, a number of nontoxic amyloids with physiologically normal functions, called functional amyloids, have been found. It is known that soluble small oligomers are more toxic than large fibrils. Thus, we study with atomistic explicit-solvent molecular dynamics simulations the oligomer formation of the amyloid- β peptide Aβ25 - 35, associated with Alzheimer's disease, and two functional amyloid-forming tachykinin peptides: kassinin and neuromedin K. Our simulations show that monomeric peptides in extended conformations aggregate faster than those in collapsed hairpin-like conformations. In addition, we observe faster aggregation by functional amyloids than toxic amyloids, which could explain their lack of toxicity.

  20. 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

  1. 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...

  2. 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.

  3. 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. PMID:26302832

  4. 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.

  5. A novel heuristic for optimization aggregate production problem: Evidence from flat panel display in Malaysia

    NASA Astrophysics Data System (ADS)

    Al-Kuhali, K.; Hussain M., I.; Zain Z., M.; Mullenix, P.

    2015-05-01

    Aim: This paper contribute to the flat panel display industry it terms of aggregate production planning. Methodology: For the minimization cost of total production of LCD manufacturing, a linear programming was applied. The decision variables are general production costs, additional cost incurred for overtime production, additional cost incurred for subcontracting, inventory carrying cost, backorder costs and adjustments for changes incurred within labour levels. Model has been developed considering a manufacturer having several product types, which the maximum types are N, along a total time period of T. Results: Industrial case study based on Malaysia is presented to test and to validate the developed linear programming model for aggregate production planning. Conclusion: The model development is fit under stable environment conditions. Overall it can be recommended to adapt the proven linear programming model to production planning of Malaysian flat panel display industry.

  6. 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

  7. Soil aggregation response to harvesting corn stover for bioenergy production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn (Zea mays L.) stover has been identified as a primary feedstock for cellulosic bioenergy production in the U.S. Corn/Soybean Belt because of the vast area upon which the crop is grown. Developing sustainable cellulosic ethanol from corn stover residue has also been identified as a high priority...

  8. Zn-phthalocyanine-functionalized nanometal and nanometal-TiO₂ hybrids: aggregation behavior and excited-state dynamics.

    PubMed

    Ashokkumar, R; Kathiravan, A; Ramamurthy, P

    2014-07-21

    Dithiol-substituted Zn-phthalocyanine derivatives (TAZnPc1, TAZnPc2 and TAZnPc3) were synthesized and functionalized on nanometals (Au and Ag) and nanometal-TiO2 hybrids were harnessed to cover the visible region of the absorption spectrum. Photophysical studies reveal that both H- and J-aggregation were present in the ZnPc-functionalized nanometal, and the extent of J-aggregation is superior on the surface of Ag nanoparticles. On the other hand, no H-aggregation was observed in the nanometal-TiO2 hybrid film, despite the fact that the tetra-anchoring derivative (TAZnPc3) shows lesser J-aggregation on the nanometal-TiO2 hybrid film than that of other two mono-anchoring derivatives (TAZnPc1 and TAZnPc2). Further, the electron injection and recombination processes were investigated by time-resolved fluorescence and absorption spectroscopy. All the derivatives furnish biexponential decay on the nanometal surface. The shorter component is due to electron injection of ZnPc-nanometal particles and the longer component is due to free ZnPc. The rate of electron injection is faster for ZnPc-gold nanoparticles than that of silver nanoparticles, predominantly in TAZnPc1. This is due to the greater aggregation tendency of ZnPc derivatives on Ag nanoparticles than Au nanoparticles. After electron injection, the electron-transfer product (i.e. the radical cation of ZnPc) was observed at 600 nm. Moreover, the fluorescence of ZnPc derivatives on nanometal-TiO2 films was completely quenched due to the shuttling of electrons from ZnPc to TiO2 efficiently by metal nanoparticles. PMID:24902514

  9. 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

  10. 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.

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

    PubMed

    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

  12. 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.

  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. 77 FR 46519 - Proposed Aggregate Production Quotas for Schedule I and II Controlled Substances and Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... assessment of annual needs (74 FR 60294 and 75 FR 79407, respectively). DEA also specifically considered that... grams of anhydrous acid or base, be established as follows: ] Proposed 2013 quotas g Basic Class... I aggregate production quotas (gamma-hydroxybutyric acid and tetrahydrocannabinols), an...

  15. 77 FR 55500 - Controlled Substances: Final Adjusted Aggregate Production Quotas for 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... aggregate production quotas for these substances as published on July 5, 2012, at 77 FR 39737 are sufficient... substances in Schedules I and II (76 FR 78044). That notice stated that the Administrator would adjust, as..., 2012 (77 FR 39737) in consideration of the outlined criteria. All interested persons were invited...

  16. Effects of macromolecular crowding on protein folding and aggregation studied by density functional theory: Dynamics

    NASA Astrophysics Data System (ADS)

    Kinjo, Akira R.; Takada, Shoji

    2002-11-01

    Inside the living cell is inherently crowded with proteins and other macromolecules. Thus, it is indispensable to take into account various interactions between the protein and other macromolecules for thorough understanding of protein functions in cellular contexts. Here we focus on the excluded volume interaction imposed on the protein by surrounding macromolecules or ``crowding agents.'' We have presented a theoretical framework for describing equilibrium properties of proteins in crowded solutions [A. R. Kinjo and S. Takada, Phys. Rev. E (to be published)]. In the present paper, we extend the theory to describe nonequilibrium properties of proteins in crowded solutions. Dynamics simulations exhibit qualitatively different morphologies depending on the aggregating conditions, and it was found that macromolecular crowding accelerates the onset of aggregation while stabilizing the native protein in the quasiuniform phase before the onset of aggregation. It is also observed, however, that the aggregation may be kinetically inhibited in highly crowded conditions. The effects of crowding on folding and unfolding of proteins are also examined, and the results suggest that fast folding is an important factor in preventing aggregation of denatured proteins.

  17. Silicification-induced cell aggregation for the sustainable production of H2 under aerobic conditions.

    PubMed

    Xiong, Wei; Zhao, Xiaohong; Zhu, Genxing; Shao, Changyu; Li, Yaling; Ma, Weimin; Xu, Xurong; Tang, Ruikang

    2015-10-01

    Photobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification-induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core-shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar-driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell-material complexes. PMID:26302695

  18. Engineered aggregation inhibitor fusion for production of highly amyloidogenic human islet amyloid polypeptide.

    PubMed

    Mirecka, Ewa Agnieszka; Gremer, Lothar; Schiefer, Stephanie; Oesterhelt, Filipp; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

    2014-12-10

    Human islet amyloid polypeptide (IAPP) is the major component of pancreatic amyloid deposits in type 2 diabetes. The structural conversion of IAPP from a monomeric state into amyloid assemblies is the subject of intense research. Recombinant production of IAPP is, however, difficult due to its extreme aggregation propensity. Here we describe a novel strategy for expression of IAPP in Escherichia coli, based on an engineered protein tag, which sequesters IAPP monomers and prevents IAPP aggregation. The IAPP-binding protein HI18 was selected by phage display from a β-wrapin library. Fusion of HI18 to IAPP enabled the soluble expression of the construct. IAPP was cleaved from the fusion construct and purified to homogeneity with a yield of 3mg of isotopically labeled peptide per liter of culture. In the monomeric state, IAPP was largely disordered as evidenced by far-UV CD and liquid-state NMR spectroscopy but competent to form amyloid fibrils according to atomic force microscopy. These results demonstrate the ability of the engineered β-wrapin HI18 for shielding the hydrophobic sequence of IAPP during expression and purification. Fusion of aggregation-inhibiting β-wrapins is a suitable approach for the recombinant production of aggregation-prone proteins. PMID:24928165

  19. Binary Aggregations in Hierarchical Galaxy Formation: The Evolution of the Galaxy Luminosity Function

    NASA Astrophysics Data System (ADS)

    Menci, N.; Cavaliere, A.; Fontana, A.; Giallongo, E.; Poli, F.

    2002-08-01

    We develop a semianalytic model of hierarchical galaxy formation with an improved treatment of the evolution of galaxies inside dark matter halos. We take into account not only dynamical friction processes building up the central dominant galaxy but also binary aggregations of satellite galaxies inside a common halo. These deplete small to intermediate mass objects, affecting the slope of the luminosity function at its faint end, with significant observable consequences. We model the effect of two-body aggregations using the kinetic Smoluchowski equation. This flattens the mass function by an amount that depends on the histories of the host halos as they grow by hierarchical clustering. The description of gas cooling, star formation and evolution, and supernova feedback follows the standard prescriptions widely used in semianalytic modeling. We find that binary aggregations are effective in depleting the number of small/intermediate mass galaxies over the redshift range 1function at the faint end. At z~0 the flattening occurs for -20-16. We compare our predicted luminosity functions with those obtained from deep multicolor surveys in the Hubble Deep Field-North, Hubble Deep Field-South, and New Technology Telescope Deep Field in the rest-frame B and UV bands for the redshift ranges 01 and even more at z~3 by the effect of the binary aggregations. The predictions from our dynamical model are discussed and compared with the effects of complementary processes (additional starburst recipes, alternative sources of feedback, different mass distribution of the dark matter halos) that may conspire in affecting the shape of the luminosity function.

  20. Cerium oxide nanoparticle aggregates affect stress response and function in Caenorhabditis elegans

    PubMed Central

    Rogers, Steven; Rice, Kevin M; Manne, Nandini DPK; Shokuhfar, Tolou; He, Kun; Selvaraj, Vellaisamy

    2015-01-01

    Objective: The continual increase in production and disposal of nanomaterials raises concerns regarding the safety of nanoparticles on the environmental and human health. Recent studies suggest that cerium oxide (CeO2) nanoparticles may possess both harmful and beneficial effects on biological processes. The primary objective of this study is to evaluate how exposure to different concentrations (0.17–17.21 µg/mL) of aggregated CeO2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans. Methods: Caenorhabditis elegans were exposed to different concentrations of CeO2 nanoparticles and evaluated. Results: Our findings demonstrate that chronic exposure of CeO2 nanoparticle aggregates is associated with increased levels of reactive oxygen species and heat shock stress response (HSP-4) in Caenorhabditis elegans, but not mortality. Conversely, CeO2 aggregates promoted strain-dependent decreases in animal fertility, a decline in stress resistance as measured by thermotolerance, and shortened worm length. Conclusion: The data obtained from this study reveal the sublethal toxic effects of CeO2 nanoparticle aggregates in Caenorhabditis elegans and contribute to our understanding of how exposure to CeO2 may affect the environment. PMID:26770770

  1. Natural organic matter concentration and hydrochemistry influence aggregation kinetics of functionalized engineered nanoparticles.

    PubMed

    Liu, Junfeng; Legros, Samuel; von der Kammer, Frank; Hofmann, Thilo

    2013-05-01

    Understanding the colloidal stability of functionalized engineered nanoparticles (FENPs) in aquatic environments is of paramount importance in order to assess the risk related to FENPs. In this study, gold nanoparticles (GNPs) of 68 and 43 nm diameter, coated with citrate and 11-mercaptoundecanoic acid (MUA) respectively, were used as models of FENPs. Time-resolved dynamic light scattering was employed to investigate the aggregation kinetics of two types of GNPs. The results show that without Suwannee river natural organic matter (SRNOM), MUA coating resulted in greater stability than citrate coating for GNPs. Cations have a destabilizing effect on both GNPs following the order Ca(2+) ≈ Mg(2+) > Na(+); different anions (Cl(-) and SO4(2-)) showed no difference in effects. In the fast aggregation regime, adding SRNOM enhanced the stability of MUA-coated GNPs in both Ca(2+) and Mg(2+) solutions. However citrate-coated GNPs were only stabilized in Mg(2+) solution but enhanced aggregation occurred in high Ca(2+) concentration due to interparticle bridging. For the investigated GNPs and in the presence of SRNOM, Ca(2+) does not always act as a strong coagulant. This indicates that for the new materials emerging from the application of nanotechnology the well-described aggregation mechanisms of colloids in the environment require a detailed re-examination. PMID:23560437

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

    DOE PAGESBeta

    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 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

  3. 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.

  4. 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

  5. Construction aggregates

    USGS Publications Warehouse

    Langer, W.H.; Tepordei, V.V.; Bolen, W.P.

    2000-01-01

    Construction aggregates consist primarily of crushed stone and construction sand and gravel. Total estimated production of construction aggregates increased in 1999 by about 2% to 2.39 Gt (2.64 billion st) compared with 1998. This record production level continued an expansion that began in 1992. By commodities, crushed stone production increased 3.3%, while sand and gravel production increased by about 0.5%.

  6. Functionalized micro-capillary film for the rapid at-line analysis of IgG aggregates in a cell culture bioreactor.

    PubMed

    Townsend, Matthew J; Gruber, David E; Kuiper, Marcel; Lazar, Radu A; Field, Ray P; Turner, Richard E; Slater, Nigel K H

    2015-01-01

    A micro-capillary film has been developed that offers the potential for an at-line analytical tool for rapid aggregate analysis during biopharmaceutical antibody production. A non-porous walled micro-capillary film (NMCF) with cation exchange functionality was demonstrated to act as a chromatography medium that could be operated with high linear fluid velocities and was highly resistant to blockage by entrained particulates, including cells. The NMCF containing 19 parallel microcapillaries was prepared using a melt extrusion process from poly(ethylene-vinyl alcohol) copolymer (EVOH). The NMCF-EVOH was modified to have cation-exchange functionality (NMCF-EVOH-SP) and shown to differentially bind monomer and aggregated species of IgG antibody directly from a bioreactor. The use of NMCF-EVOH-SP to quantify aggregate concentrations in monoclonal antibody preparations in less than 20 minutes was demonstrated. PMID:26176737

  7. Functionalized micro-capillary film for the rapid at-line analysis of IgG aggregates in a cell culture bioreactor

    PubMed Central

    Townsend, Matthew J; Gruber, David E; Kuiper, Marcel; Lazar, Radu A; Field, Ray P; Turner, Richard E; Slater, Nigel KH

    2015-01-01

    A micro-capillary film has been developed that offers the potential for an at-line analytical tool for rapid aggregate analysis during biopharmaceutical antibody production. A non-porous walled micro-capillary film (NMCF) with cation exchange functionality was demonstrated to act as a chromatography medium that could be operated with high linear fluid velocities and was highly resistant to blockage by entrained particulates, including cells. The NMCF containing 19 parallel microcapillaries was prepared using a melt extrusion process from poly(ethylene-vinyl alcohol) copolymer (EVOH). The NMCF-EVOH was modified to have cation-exchange functionality (NMCF-EVOH-SP) and shown to differentially bind monomer and aggregated species of IgG antibody directly from a bioreactor. The use of NMCF-EVOH-SP to quantify aggregate concentrations in monoclonal antibody preparations in less than 20 minutes was demonstrated. PMID:26176737

  8. 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.

  9. Luminal platelet aggregates in functional deficits in parenchymal vessels after subarachnoid hemorrhage

    PubMed Central

    Friedrich, Victor; Flores, Rowena; Muller, Artur; Sehba, Fatima A.

    2010-01-01

    The pathophysiology of early ischemic injury after aneurysmal subarachnoid hemorrhage (SAH) is not understood. This study examined the acute effect of endovascular puncture-induced SAH on parenchymal vessel function in rat, using intravascular fluorescent tracers to assess flow and vascular permeability and immunostaining to assess structural integrity and to visualize platelet aggregates. In sham-operated animals, vessels were well filled with tracer administered 10 seconds before sacrifice, and parenchymal escape of tracer was rare. At ten minutes and 3 hours after hemorrhage, patches of poor vascular filling were distributed throughout the forebrain. Close examination of these regions revealed short segments of narrowed diameter along many profiles. Most vascular profiles with reduced perfusion contained platelet aggregates and in addition showed focal loss of collagen IV, a principal component of basal lamina. In contrast, vessels were well filled at 24 hours post-hemorrhage, indicating that vascular perfusion had recovered. Parenchymal escape of intravascular tracer was detected at 10 minutes post-hemorrhage and later as plumes of fluorescence emanating into parenchyma from restricted microvascular foci. These data demonstrate that parenchymal microvessels are compromised in function by 10 minutes after SAH and identify focal microvascular constriction and local accumulation of luminal platelet aggregates as potential initiators of that compromise. PMID:20654597

  10. Mesoscale conductivity and scaling function in aggregates of cubic, trigonal, hexagonal, and tetragonal crystals

    NASA Astrophysics Data System (ADS)

    Ranganathan, Shivakumar I.; Ostoja-Starzewski, Martin

    2008-06-01

    The framework of stochastic mechanics is used to obtain scale-dependent bounds on the thermal conductivity of random polycrystals. This is done with the help of a scaling function that enables one to define the mesoscale that separates the effective, macroscopic conductivity from the realization-dependent microscale conductivity. We demonstrate that the scaling function depends upon the single-crystal anisotropy measure (k) and the mesoscale (δ) for aggregates made up of cubic, trigonal, hexagonal, and tetragonal single crystals. The proposed methodology unifies the treatment of a variety of crystals over different length scales. Finally, we develop a methodology to construct a material selection diagram in the (k-δ) space.

  11. Density functional theory of equilibrium random copolymers: application to surface adsorption of aggregating peptides

    NASA Astrophysics Data System (ADS)

    Wang, Haiqiang; Forsman, Jan; Woodward, Clifford E.

    2016-06-01

    We generalize a recently developed polymer density functional theory (PDFT) for polydisperse polymer fluids to the case of equilibrium random copolymers. We show that the generalization of the PDFT to these systems allows us to obtain a remarkable simplification compared to the monodispersed polymers. The theory is used to treat a model for protein aggregation into linear filaments in the presence of surfaces. Here we show that, for attractive surfaces, there is evidence of significant enhancement of protein aggregation. This behaviour is a consequence of a surface phase transition, which has been shown to occur with ideal equilibrium polymers in the presence of sufficiently attractive surfaces. For excluding monomers, this transition is suppressed, though an echo of the underlying ideal transition is present in the sudden change in the excess adsorption.

  12. Formation of nucleoplasmic protein aggregates impairs nuclear function in response to SiO2 nanoparticles.

    PubMed

    Chen, Min; von Mikecz, Anna

    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(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(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. PMID:15777787

  13. Density functional theory of equilibrium random copolymers: application to surface adsorption of aggregating peptides.

    PubMed

    Wang, Haiqiang; Forsman, Jan; Woodward, Clifford E

    2016-06-22

    We generalize a recently developed polymer density functional theory (PDFT) for polydisperse polymer fluids to the case of equilibrium random copolymers. We show that the generalization of the PDFT to these systems allows us to obtain a remarkable simplification compared to the monodispersed polymers. The theory is used to treat a model for protein aggregation into linear filaments in the presence of surfaces. Here we show that, for attractive surfaces, there is evidence of significant enhancement of protein aggregation. This behaviour is a consequence of a surface phase transition, which has been shown to occur with ideal equilibrium polymers in the presence of sufficiently attractive surfaces. For excluding monomers, this transition is suppressed, though an echo of the underlying ideal transition is present in the sudden change in the excess adsorption. PMID:27115518

  14. 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. PMID:26169127

  15. Mixing state of bi-component mixtures under aggregation with a product kernel

    NASA Astrophysics Data System (ADS)

    Fernández-Díaz, J. M.; Gómez-García, G. J.

    2010-05-01

    We analyze the aggregation of a two-component system with a product kernel, to determine its evolution in time during a progressive mixing. The evolution is governed by the Smoluchowski equation, yielding gelation from a certain time. In the past, equilibrium (or asymptotic) solutions have been used to study mixing of bi-component mixtures for non-gelling kernels. In this letter we show that asymptotic solutions are invalid to describe the mixing behavior for the product kernel case (even before gelation). Besides, an equilibrium concentration is not reached. On the contrary, particles with any composition exist all time.

  16. 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

  17. 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.

  18. 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. PMID:18804911

  19. 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.

  20. MSi₂₀H₂₀ aggregates: from simple building blocks to highly magnetic functionalized materials.

    PubMed

    Palagin, Dennis; Reuter, Karsten

    2013-02-26

    Density-functional theory based global geometry optimization is used to scrutinize the possibility of using endohedrally doped hydrogenated Si clusters as building blocks for constructing highly magnetic materials. In contrast to the known clathrate-type facet-sharing, the clusters exhibit a predisposition to aggregation through double Si-Si bridge bonds. For the prototypical CrSi₂₀H₂₀ cluster we show that reducing the degree of hydrogenation may be used to control the number of reactive sites to which other cages can be attached, while still preserving the structural integrity of the building block itself. This leads to a toolbox of CrSi₂₀H(20-2n) monomers with different number of double "docking sites", that allows building network architectures of any morphology. For (CrSi₂₀H₁₈)₂ dimer and [CrSi₂₀H₁₆](CrSi₂₀H₁₈)₂ trimer structures we illustrate that such aggregates conserve the high spin moments of the dopant atoms and are therefore most attractive candidates for cluster-assembled materials with unique magnetic properties. The study suggests that the structural completion of the individual endohedral cages within the doubly bridge bonded structures and the high thermodynamic stability of the obtained aggregates are crucial for potential synthetic polimerization routes via controlled dehydrogenation. PMID:23339372

  1. MAVS Forms Functional Prion-Like Aggregates To Activate and Propagate Antiviral Innate Immune Response

    PubMed Central

    Hou, Fajian; Sun, Lijun; Zheng, Hui; Skaug, Brian; Jiang, Qiu-Xing; Chen, Zhijian J.

    2011-01-01

    SUMMARY In response to viral infection, RIG-I–like RNA helicases bind to viral RNA and activate the mitochondrial protein MAVS, which in turn activates the transcription factors IRF3 and NF-κB to induce type-I interferons. We have previously shown that RIG-I binds to unanchored lysine-63 (K63) polyubiquitin chains and that this binding is important for MAVS activation; however, the mechanism underlying MAVS activation is not understood. Here we show that viral infection induces the formation of very large MAVS aggregates, which potently activate IRF3 in the cytosol. We find that a fraction of recombinant MAVS protein forms fibrils capable of activating IRF3. Remarkably, the MAVS fibrils behave like prions and effectively convert endogenous MAVS into functional aggregates. We also show that, in the presence of K63 ubiquitin chains, RIG-I catalyzes the conversion of MAVS on the mitochondrial membrane to prion-like aggregates. These results suggest that a prion-like conformational switch of MAVS activates and propagates the antiviral signaling cascade. PMID:21782231

  2. 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

  3. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1994-01-01

    Part of a special section on industrial minerals in 1993. The 1993 production of construction aggregates increased 6.3 percent over the 1992 figure, to reach 2.01 Gt. This represents the highest estimated annual production of combined crushed stone and construction sand and gravel ever recorded in the U.S. The outlook for construction aggregates and the issues facing the industry are discussed.

  4. 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

  5. Utilization of Illinois slags for the production of ultra-lightweight aggregates

    SciTech Connect

    Choudhry, V. ); Zimmerle, T. ); Banerjee, D.D. )

    1993-01-01

    The objective of this program is to demonstrate that solid residues (slag) from the gasification of Illinois coals can be utilized to manufacture ultra-lightweight aggregates (ULWA). Conventional ULWAs are made by pyroprocessing perlite ores and have unit weights in the range of 3--15 lb/ft[sup 3]. In a previous project, Praxis Engineers demonstrated at the pilot scale that lightweight aggregates with unit weights of 40--55 lb/ ft[sup 3] can be produced from Illinois coal slags, which is suitable for making lightweight cement concrete and precast blocks. These tests also indicated that a product with a unit weight of less than 25 lb/ft[sup 3] could be produced from slag. This project is aimed at testing the potential for producing ULWA from Illinois coal slags. Target applications include loose fill insulation, insulating concrete, lightweight precast products such as concrete blocks and rooftiles, and filtration media. Laboratory- and pilot-scale testing is being conducted in Phase I to identify operating conditions for the expansion of Illinois slags to produce ULWA. Following this, a large batch of expanded slag will be produced, for evaluation in various applications in Phase II.

  6. Characterization and removal of aggregates formed by nonspecific interaction of IgM monoclonal antibodies with chromatin catabolites during cell culture production.

    PubMed

    Gan, Hui Theng; Lee, Jeremy; Latiff, Sarah Maria Abdul; Chuah, Cindy; Toh, Phyllicia; Lee, Wan Yee; Gagnon, Pete

    2013-05-24

    We observed that IgM monoclonal antibodies and aggregates in mammalian cell culture supernatants were associated nonspecifically with nucleosomes, DNA, and histone proteins derived from nuclei of host cells that died during antibody production. A series of multimodal sample treatments were evaluated for their ability to selectively remove these contaminants without significant antibody loss. The first consisted of adding 2,5-dioxo-4-imidazolidinyl urea (allantoin) and the DNA intercalating agent 7-ethoxyacridine-3,9-diamine (ethacridine), then flowing the supernatant through a column of mixed porous particles bearing metal affinity, anion exchange, and cation exchange functionalities. A one-step variant of the method was to mix chromatography particles with the allantoin-ethacridine-treated supernatant. An alternative one-step treatment consisted of passing untreated cell supernatant through a chelating monolith in tandem with an anion exchange monolith. All methods eliminated high molecular weight aggregates, and reduced smaller aggregates to 2-4%. They also achieved 98% DNA reduction, 99% reduction of nucleosomes and histones, 30-70% reduction of general host proteins, and 98% IgM recovery. Size exclusion chromatography analysis indicated that IgG monoclonal antibodies benefit similarly from treatment. Subsequent IgM purification reduced DNA levels beneath the level of detectability by fluorescent dye intercalation, histones to less than 10 parts per million by ELISA, and aggregates to less than 0.05% by size exclusion chromatography. The results point to chromatin catabolites as promoters of antibody aggregate formation. PMID:23598159

  7. Discriminatory detection of cysteine and homocysteine based on dialdehyde-functionalized aggregation-induced emission fluorophores.

    PubMed

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

    2013-01-01

    We demonstrate a concept-proof work of using fluorescence (FL) "turn-on" probes for the discriminatory detection of cysteine (Cys) over homocysteine (Hcy). The fluorogens are provided with aggregation-induced emission (AIE) characteristic and functionalized with two aldehyde-groups (DMTPS-ALD and TPE-ALD). All the detections were carried out in a biocompatible medium (10 mM HEPES buffer and DMSO, pH 7.4). In principle, the formation of thiazinane/thiazolidine through the chemical reaction of aldehydes on the probe molecules and the residue of Cys/Hcy determines the selective recognition of Cys and Hcy over other amino acids and glucose. The FL responses originate from the AIE property of thiazinane/thiazolidine resultants, which have low solubility and precipitate (aggregate) in the detection medium. The discrimination between Cys and Hcy comes from the difference in reaction kinetics of TPE-ALD/DMTPS-ALD with Cys and Hcy, thereby the FL responses show different time courses and intensity enhancement. It is worth noting that TPE-ALD outshined the other two probes in performance with fast response, a high FL enhancement up to 16-fold, high sensitivity, and good specificity and selectivity. Moreover, its FL response threshold at 250 μM is very close to the lower limit of the normal level of Cys in human plasma, which implies that TPE-ALD could be applied as a potential indicator of Cys deficiency. PMID:23193021

  8. α-Synuclein Fibrils Exhibit Gain of Toxic Function, Promoting Tau Aggregation and Inhibiting Microtubule Assembly.

    PubMed

    Oikawa, Takayuki; Nonaka, Takashi; Terada, Makoto; Tamaoka, Akira; Hisanaga, Shin-Ichi; Hasegawa, Masato

    2016-07-15

    α-Synuclein is the major component of Lewy bodies and Lewy neurites in Parkinson disease and dementia with Lewy bodies and of glial cytoplasmic inclusions in multiple system atrophy. It has been suggested that α-synuclein fibrils or intermediate protofibrils in the process of fibril formation may have a toxic effect on neuronal cells. In this study, we investigated the ability of soluble monomeric α-synuclein to promote microtubule assembly and the effects of conformational changes of α-synuclein on Tau-promoted microtubule assembly. In marked contrast to previous findings, monomeric α-synuclein had no effect on microtubule polymerization. However, both α-synuclein fibrils and protofibrils inhibited Tau-promoted microtubule assembly. The inhibitory effect of α-synuclein fibrils was greater than that of the protofibrils. Dot blot overlay assay and spin-down techniques revealed that α-synuclein fibrils bind to Tau and inhibit microtubule assembly by depleting the Tau available for microtubule polymerization. Using various deletion mutants of α-synuclein and Tau, the acidic C-terminal region of α-synuclein and the basic central region of Tau were identified as regions involved in the binding. Furthermore, introduction of α-synuclein fibrils into cultured cells overexpressing Tau protein induced Tau aggregation. These results raise the possibility that α-synuclein fibrils interact with Tau, inhibit its function to stabilize microtubules, and also promote Tau aggregation, leading to dysfunction of neuronal cells. PMID:27226637

  9. 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. PMID:22329137

  10. The response of aggregate production to fertility-induced changes in population age distribution.

    PubMed

    Denton, F T; Mountain, D C; Spencer, B G

    1996-01-01

    With a particular focus upon long-term supply effects, the authors explored the implications of different population age distributions for the productive capacity of an economy. A multilevel aggregate production process was specified, plausible values assigned to its parameters, and steady-state solutions obtained under a range of alternative fertility assumptions. The theoretical model was calibrated to conform with Canadian data and published estimates of age-sex substitution elasticities. The study found productive capacity to be related to age distribution, although the output effects exceed 8%, regardless of the structure of the economy, only when total fertility rate is less than 1.6 or well above 3.0; within the range of variation, productive capacity and output per capita are lower for both younger and older populations; altering the elasticity of substitution between different tasks has negligible effects upon the sensitivity of the economy to changes in age distribution; altering the elasticity of substitution between different age-sex groups for a given task has a markedly greater effect; introducing either increasing or decreasing returns to scale has only a minor effect upon the sensitivity of the economy to changes in age distribution; and marginal products are quite sensitive to changes in age distribution for both younger and older workers, but far less sensitive for middle-aged workers. PMID:12320140

  11. Sound production by dusky grouper Epinephelus marginatus at spawning aggregation sites.

    PubMed

    Bertucci, F; Lejeune, P; Payrot, J; Parmentier, E

    2015-08-01

    Sound production by the dusky grouper Epinephelus marginatus was monitored both in captivity and at two Mediterranean spawning sites during the summers of 2012 and 2013. The results of long-term passive acoustic recordings provide for the first time a description of the sounds produced by E. marginatus. Two types of sounds were mainly recorded and consisted of low-frequency booms that can be produced singly or in series with dominant frequencies below 100 Hz. Recordings in captivity validated these sounds as belonging to E. marginatus and suggested that they may be associated with reproductive displays usually performed during early stages of courtship behaviour. This study also allowed the identification of a third, low-frequency growl-like type of sound typically found in other grouper species. These growls were, however, not recorded in tanks and it is cautiously proposed that they are produced by E. marginatus. Acoustic signals attributed to E. marginatus were produced throughout the spawning season, with a diel pattern showing an increase before dusk, i.e., from 1900 to 2200 hours, before decreasing until the morning. The occurrence of sounds during the spawning season of this species suggests that they are probably involved in social activity occurring close to aggregation sites. Passive acoustics offer a helpful tool to monitor aggregation sites of this emblematic species in order to improve conservation efforts. PMID:26177857

  12. 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…

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

    PubMed

    Kim, Haseog; Park, Sangki; Kim, Hayong

    2016-01-01

    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

  14. 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

  15. Soil aggregate stability and grassland productivity associations in a northern mixed-grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil (aggregate) stability is widely used as an indicator of soil and rangeland health. The empirical evidence justifying soil aggregate stability as an indicator of rangeland health, however, is thin and confusing. Here we revisit the hypothesis that soil aggregate stability is positively correla...

  16. 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. PMID:24412653

  17. 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. PMID:26728283

  18. 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

  19. 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.

  20. 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. PMID:26071898

  1. Large area aggregation and mean-squared prediction error estimation for LACIE yield and production forecasts. [wheat

    NASA Technical Reports Server (NTRS)

    Chhikara, R. S.; Feiveson, A. H. (Principal Investigator)

    1979-01-01

    Aggregation formulas are given for production estimation of a crop type for a zone, a region, and a country, and methods for estimating yield prediction errors for the three areas are described. A procedure is included for obtaining a combined yield prediction and its mean-squared error estimate for a mixed wheat pseudozone.

  2. 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.

  3. Rapid Non-Crosslinking Aggregation of DNA-Functionalized Gold Nanorods and Nanotriangles for Colorimetric Single-Nucleotide Discrimination.

    PubMed

    Wang, Guoqing; Akiyama, Yoshitsugu; Takarada, Tohru; Maeda, Mizuo

    2016-01-01

    Gold nanoparticles modified with DNA duplexes are rapidly and spontaneously aggregated at high ionic strength. In contrast, this aggregation is greatly suppressed when the DNA duplex has a single-base mismatch or a single-nucleotide overhang located at the outermost surface of the particle. These colloidal features emerge irrespective of the size and composition of the particle core; however, the effects of the shape remain unexplored. Using gold nanorods and nanotriangles (nanoplatelets), we show herein that both remarkable rapidity in colloidal aggregation and extreme susceptibility to DNA structural perturbations are preserved, regardless of the shape and aspect ratio of the core. It is also demonstrated that the DNA-modified gold nanorods and nanotriangles are applicable to naked-eye detection of a single-base difference in a gene model. The current study corroborates the generality of the unique colloidal properties of DNA-functionalized nanoparticles, and thus enhances the feasibility of their practical use. PMID:26767586

  4. 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. PMID:26893056

  5. Enhanced Biological Functions of Human Mesenchymal Stem-Cell Aggregates Incorporating E-Cadherin-Modified PLGA Microparticles.

    PubMed

    Zhang, Yan; Mao, Hongli; Gao, Chao; Li, Suhua; Shuai, Qizhi; Xu, Jianbin; Xu, Ke; Cao, Lei; Lang, Ren; Gu, Zhongwei; Akaike, Toshihiro; Yang, Jun

    2016-08-01

    Mesenchymal stem cells (MSCs) have emerged as a promising source of multipotent cells for various cell-based therapies due to their unique properties, and formation of 3D MSC aggregates has been explored as a potential strategy to enhance therapeutic efficacy. In this study, poly(lactic-co-glycolic acid) (PLGA) microparticles modified with human E-cadherin fusion protein (hE-cad-PLGA microparticles) have been fabricated and integrated with human MSCs to form 3D cell aggregates. The results show that, compared with the plain PLGA, the hE-cad-PLGA microparticles distribute within the aggregates more evenly and further result in a more significant improvement of cellular proliferation and secretion of a series of bioactive factors due to the synergistic effects from the bioactive E-cadherin fragments and the PLGA microparticles. Meanwhile, the hE-cad-PLGA microparticles incorporated in the aggregates upregulate the phosphorylation of epidermal growth factor receptors and activate the AKT and ERK1/2 signaling pathways in the MSCs. Additionally, the E-cadherin/β-catenin cellular membrane complex in the MSCs is markedly stimulated by the hE-cad-PLGA microparticles. Therefore, engineering 3D cell aggregates with hE-cad-PLGA microparticles can be a promising method for ex vivo multipotent stem-cell expansion with enhanced biological functions and may offer a novel route to expand multipotent stem-cell-based clinical applications. PMID:27245478

  6. Uncovering methods for the prevention of protein aggregation and improvement of product quality in a transient expression system.

    PubMed

    Estes, Bram; Hsu, Yueh-Rong; Tam, Lei-Ting; Sheng, Jackie; Stevens, Jennitte; Haldankar, Raj

    2015-01-01

    Mammalian expression systems are used routinely for the production of recombinant proteins as therapeutic molecules as well as research tools. Transient expression has become increasingly popular in recent years due to its rapid timeline and improvements in expression level. While improvements to transient expression systems have focused mainly on the level of protein expression, the aspect of protein quality has received little attention. The removal of undesirable products, such as aggregation, depends primarily on purification, requiring additional cumbersome steps, which can lead to a lower product yield and longer timelines. In this study, we show that reducing the level of transcription by transfecting at a lower gene dose improves the quality of secreted molecules prone to aggregation. For gene dosing to have this effect, it is critical for the carrier DNA to be an empty vector containing the same elements as the gene containing plasmid. This approach can be used in combination with a temperature shift to hypothermic conditions during production to enhance the effect. The observed improvements not only minimized aggregation levels, but also generated products with overall superior quality, including more homogeneous signal peptide cleavage and N-linked glycosylation profiles. These techniques have produced a similar improvement in product quality with a variety of other molecules, suggesting that this may be a general approach to enhance product quality from transient expression systems. PMID:25395220

  7. 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. PMID:24534901

  8. Inhibition of platelet aggregation and reduced formation of thromboxane and lipoxygenase products in platelets by oil of cloves.

    PubMed

    Srivastava, K C; Justesen, U

    1987-09-01

    Oil of cloves (OC) was found to be a potent inhibitor of platelet aggregation induced by arachidonic acid (AA), collagen and epinephrine; in this respect it was most effective against AA-induced aggregation. Inhibition of aggregation by OC seems to be mediated through a reduced formation of thromboxane as indicated by the following experimental evidence. (i) OC inhibited TxB2 formation in intact as well as lysed platelet preparations from added arachidonate, and (ii) it inhibited the formation of TxB2 from AA-labelled platelets after activation with Ca2+-ionophore A23187. The formation of lipoxygenase derived products was dependent on the concentration of OC used; at its lower concentration their amounts increased but this was found to be reversed at higher concentrations. At all concentrations thromboxane was decreased with a concomitant increase in unused AA. PMID:3118394

  9. Validation of an aggregate exposure model for substances in consumer products: a case study of diethyl phthalate in personal care products

    PubMed Central

    Delmaar, Christiaan; Bokkers, Bas; ter Burg, Wouter; Schuur, Gerlienke

    2015-01-01

    As personal care products (PCPs) are used in close contact with a person, they are a major source of consumer exposure to chemical substances contained in these products. The estimation of realistic consumer exposure to substances in PCPs is currently hampered by the lack of appropriate data and methods. To estimate aggregate exposure of consumers to substances contained in PCPs, a person-oriented consumer exposure model has been developed (the Probabilistic Aggregate Consumer Exposure Model, PACEM). The model simulates daily exposure in a population based on product use data collected from a survey among the Dutch population. The model is validated by comparing diethyl phthalate (DEP) dose estimates to dose estimates based on biomonitoring data. It was found that the model's estimates compared well with the estimates based on biomonitoring data. This suggests that the person-oriented PACEM model is a practical tool for assessing realistic aggregate exposures to substances in PCPs. In the future, PACEM will be extended with use pattern data on other product groups. This will allow for assessing aggregate exposure to substances in consumer products across different product groups. PMID:25352161

  10. Glycation by Ascorbic Acid Oxidation Products Leads to the Aggregation of Lens Proteins

    PubMed Central

    Linetsky, Mikhail; Shipova, Ekaterina; Cheng, Rongzhu; Ortwerth, Beryl J.

    2008-01-01

    Previous studies from this laboratory have shown that there are striking similarities between the yellow chromophores, fluorophores and modified amino acids released by proteolytic digestion from calf lens proteins ascorbylated in vitro and their counterparts isolated from aged and cataractous lens proteins. The studies reported in this communication were conducted to further investigate whether ascorbic acid-mediated modification of lens proteins could lead to the formation of lens protein aggregates capable of scattering visible light, similar to the high molecular aggregates found in aged human lenses. Ascorbic acid, but not glucose, fructose, ribose or erythrulose, caused the aggregation of calf lens proteins to proteins ranging from 2.2 × 106 up to 3.0 × 108 Da. This compared to proteins ranging from 1.8 × 106 up to 3.6 × 108 Da for the water-soluble (WS) proteins isolated from aged human lenses. This aggregation was likely due to the glycation of lens crystallins because [U-14C] ascorbate was incorporated into the aggregate fraction and because CNBH3, which reduces the initial Schiff base, prevented any protein aggregation. Reactions of ascorbate with purified crystallin fractions showed little or no aggregation of α-crystallin, significant aggregation of βH-crystallin, but rapid precipitation of purified βL- and γ-crystallin. The aggregation of lens proteins can be prevented by the binding of damaged crystallins to alpha-crystallin due to its chaperone activity. Depending upon the ratios between the components of the incubation mixtures, α-crystallin prevented the precipitation of the purified βL- and γ-crystallin fractions during ascorbylation. The addition of at least 20% of alpha-crystallin by weight into glycation mixtures with βL-, or γ-crystallins completely inhibited protein precipitation, and increased the amount of the high molecular weight aggregates in solution. Static and dynamic light scattering measurements of the supernatants from

  11. Construction aggregates

    USGS Publications Warehouse

    Bolen, W.P.; Tepordei, V.V.

    2001-01-01

    The estimated production during 2000 of construction aggregates, crushed stone, and construction sand and gravel increased by about 2.6% to 2.7 Gt (3 billion st), compared with 1999. The expansion that started in 1992 continued with record production levels for the ninth consecutive year. By commodity, construction sand and gravel production increased by 4.5% to 1.16 Gt (1.28 billion st), while crushed stone production increased by 1.3% to 1.56 Gt (1.72 billion st).

  12. Production of lightweight aggregates from mining residues, heavy metal sludge, and incinerator fly ash.

    PubMed

    Huang, Su-Chen; Chang, Fang-Chih; Lo, Shang-Lien; Lee, Ming-Yu; Wang, Chu-Fang; Lin, Jyh-Dong

    2007-06-01

    In this study, artificial lightweight aggregate (LWA) manufactured from recycled resources was investigated. Residues from mining, fly ash from an incinerator and heavy metal sludge from an electronic waste water plant were mixed into raw aggregate pellets and fed into a tunnel kiln to be sintered and finally cooled rapidly. Various feeding and sintering temperatures were employed to examine their impact on the extent of vitrification on the aggregate surface. Microstructural analysis and toxicity characteristic leaching procedure (TCLP) were also performed. The results show that the optimum condition of LWA fabrication is sintering at 1150 degrees C for 15 min with raw aggregate pellets fed at 750 degrees C. The rapidly vitrified surface envelops the gas produced with the increase in internal temperature and cooling by spraying water prevents the aggregates from binding together, thus forming LWA with specific gravity of 0.6. LWA produced by sintering in tunnel kiln shows good vitrified surface, low water absorption rate below 5%, and low cylindrical compressive strength of 4.3 MPa. In addition, only trace amounts of heavy metals were detected, making the LWA non-hazardous for construction use. PMID:17118542

  13. 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

    2015-09-25

    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. PMID:26444593

  14. Transparent exopolymer particle production and aggregation by a marine planktonic diatom (Thalassiosira weissflogii) at different growth rates.

    PubMed

    Chen, Jie; Thornton, Daniel C O

    2015-04-01

    Transparent exopolymer particles (TEP) play an important role in the ocean carbon cycle as they are sticky and affect particle aggregation and the biological carbon pump. We investigated the effect of growth rate on TEP production in nitrogen limited semi-continuous cultures of the diatom Thalassiosira weissflogii (Grunow) G. Fryxell & Hasle. Steady-state diatom concentrations and other indicators of biomass (chl a, and total carbohydrate) were inversely related to growth rate, while individual cell volume increased with growth rate. There was no change in total TEP area with growth rate; however, individual TEP were larger at high growth rates and the number of individual TEP particles was lower. TEP concentration per cell was higher at higher growth rates. SYTOX Green staining showed that <5% of the diatom population had permeable cell membranes, with the proportion increasing at low growth rates. However, TEP production rates were greater at high growth rates, refuting our hypothesis that TEP formation is dependent on dying cells with compromised cell membranes in a diatom population. Measurements of particle size distribution in the cultures using laser scattering showed that they were most aggregated at high growth rates. These results indicate a coupling between TEP production and growth rate in diatoms under N limitation, with fast growing T. weissflogii producing more TEP and aggregates. PMID:26986532

  15. 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. PMID:25947895

  16. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1993-01-01

    Part of a special section on the market performance of industrial minerals in 1992. Production of construction aggregates increased by 4.6 percent in 1992. This increase was due, in part, to the increased funding for transportation and infrastructure projects. The U.S. produced about 1.05 Gt of crushed stone and an estimated 734 Mt of construction sand and gravel in 1992. Demand is expected to increase by about 5 percent in 1993.

  17. 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.

  18. 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.

  19. Large-scale runoff routing with an aggregated network-response function

    NASA Astrophysics Data System (ADS)

    Gong, L.; Widén-Nilsson, E.; Halldin, S.; Xu, C.-Y.

    2009-04-01

    SummaryThe accuracy of runoff routing for global water-balance models and land-surface schemes is limited by the low spatial resolution of flow networks. Many such networks have been developed for specific models at specific spatial resolutions. However, although low-resolution networks can be derived by up-scaling algorithms from high-resolution datasets, such low-resolution networks are inherently incoherent, and slight differences in their spatial resolution can cause significant deviations in routing dynamics. By neglecting convective delay, storage-based routing algorithms produce artificially early arriving peaks on large scales. A theoretical comparison between a diffusion-wave-routing algorithm and linear-reservoir-routing (LRR) algorithm on a 30-km cell demonstrated that the commonly used LRR method consistently underestimates the travel time through the cells. A new aggregated network-response-function ( NRF) routing algorithm was proposed in this study and evaluated against a conventional flow-net-based cell-to-cell LRR algorithm. The evaluation was done for the 25,325 km 2 Dongjiang (East River) basin, a tributary to the Pearl River in southern China well equipped with hydrological and meteorological stations. The NRF method transfers high-resolution delay dynamics, instead of networks, to any lower spatial resolution where runoff is generated. It preserves, over all scales, the spatially distributed time-delay information in the 1-km HYDRO1k flow network in the form of simple cell-response functions for any low-resolution grid. The NRF routing was shown to be scale independent for latitude-longitude resolutions ranging from 5' to 1°. This scale independency allowed a study of input heterogeneity on modelled discharge modelled with a daily version of the WASMOD-M water-balance model. The model efficiency of WASMOD-M-generated daily discharge at the Boluo gauging station in the Dongjiang basin in south China was constantly high (0.89) within the whole

  20. 77 FR 59980 - Established Aggregate Production Quotas for Schedule I and II Controlled Substances and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... g Hydroxypethidine 2 g Ibogaine 5 g Lysergic acid diethylamide (LSD) 30 g Marihuana 21,000 g... 2013,'' was published in the Federal Register (77 FR 46519). That notice proposed the 2013 aggregate... sale), codeine (for conversion), codeine (for sale), gamma hydroxybutyric acid, hydrocodone (for...

  1. 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.

  2. Investigating the Function of Coronin A in the Early Starvation Response of Dictyostelium discoideum by Aggregation Assays.

    PubMed

    Drexler, Stefan K; Brogna, Francesco; Vinet, Adrien; Pieters, Jean

    2016-01-01

    Dictyostelium discoideum amoeba are found in soil, feeding on bacteria. When food sources become scarce, they secrete factors to initiate a multicellular development program, during which single cells chemotax towards aggregation centers(1-4). This process is dependent on the release of cyclic adenosine monophosphate (cAMP)(5). cAMP is produced in waves through the concerted action of adenylate cyclase and phosphodiesterases, and binds to G protein-coupled cAMP receptors(6,7). A widely used assay to analyze the mechanisms involved in the developmental cycle of the lower eukaryote Dictyostelium discoideum is based on the observation of cell aggregation in submerged conditions(8,9). This protocol describes the analysis of the role of coronin A in the developmental cycle by starvation in tissue-culture plates submerged in balanced salt solution (BSS)(10). Coronin A is a member of the widely conserved protein family of coronins that have been implicated in a wide variety of activities(11,12). Dictyostelium cells lacking coronin A are unable to form multicellular aggregates, and this defect can be rescued by supplying pulses of cAMP, suggesting that coronin A acts upstream of the cAMP cascade(10). The techniques described in these studies provide robust tools to investigate functions of proteins during the initial stages of the developmental cycle of Dictyostelium discoideum upstream of the cAMP cascade. Therefore, utilizing this aggregation assay may allow the further study of coronin A function and advance our understanding of coronin biology. PMID:27403805

  3. Production Decline Analysis Using Influence Functions

    SciTech Connect

    Zais, Elliot J.

    1980-12-16

    We previously reported (Zais, 1979) that Arps's exponential equation works quite well on geothermal production data. The hyperbolic equation should probably not be used. In this paper we show the progress made i n using influence functions t o describe reservoir production behavior.

  4. 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

  5. Thermal Stress Induced Aggregation of Aquaporin 0 (AQP0) and Protection by α-Crystallin via Its Chaperone Function

    PubMed Central

    Swamy-Mruthinti, Satyanarayana; Srinivas, Volety; Hansen, John E.; Rao, Ch Mohan

    2013-01-01

    Aquaporin 0 (AQP0) formerly known as membrane intrinsic protein (MIP), is expressed exclusively in the lens during terminal differentiation of fiber cells. AQP0 plays an important role not only in the regulation of water content but also in cell-to-cell adhesion of the lens fiber cells. We have investigated the thermal stress-induced structural alterations of detergent (octyl glucoside)-solubilized calf lens AQP0. The results show an increase in the amount of AQP0 that aggregated as the temperature increased from 40°C to 65°C. α-Crystallin, molecular chaperone abundantly present in the eye lens, completely prevented the AQP0 aggregation at a 1∶1 (weight/weight) ratio. Since α-crystallin consists of two gene products namely αA- and αB-crystallins, we have tested the recombinant proteins on their ability to prevent thermal-stress induced AQP0 aggregation. In contrast to the general observation made with other target proteins, αA-crystallin exhibited better chaperone-like activity towards AQP0 compared to αB-crystallin. Neither post-translational modifications (glycation) nor C-terminus truncation of AQP0 have any appreciable effect on its thermal aggregation properties. α-Crystallin offers similar protection against thermal aggregation as in the case of the unmodified AQP0, suggesting that αcrystallin may bind to either intracellular loops or other residues of AQP0 that become exposed during thermal stress. Far-UV circular dichroism studies indicated a loss of αhelical structures when AQP0 was subjected to temperatures above 45°C, and the presence of α-crystallin stabilized these secondary structures. We report here, for the first time, that α-crystallin protects AQP0 from thermal aggregation. Since stress-induced structural perturbations of AQP0 may affect the integrity of the lens, presence of the molecular chaperone, α-crystallin (particularly αA-crystallin) in close proximity to the lens membrane is physiologically relevant. PMID:24312215

  6. Exploring the aggregation of four functional measures in a population of older adults with joint pain and comorbidity

    PubMed Central

    2013-01-01

    Background In clinical settings, it is important for health care providers to measure different aspects of functioning in older adults with joint pain and comorbidity. Besides the use of distinct measures, it could also be attractive to have one general measure of functioning that incorporates several distinct measures, but provides one summary score to quantify overall level of functioning, for example for the identification of older adults at risk of poor functional outcome. Therefore, we selected four measures of functioning: Physical Functioning (PF), Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL) and participation, and tested the possibility to aggregate these measures into one general measure of functioning. Methods A prospective cohort study of older adults (≥65 years) with joint pain and comorbidity provided baseline data (n = 407) consisting of PF (PF subscale, RAND-36; 10 items), ADL (KATZ index; 6 items), IADL (Lawton index; 7 items) and participation (KAP; 6 items). We tested two models with confirmatory factor analysis: first, a bifactor model with all four measures and second, a bifactor model with PF, ADL and IADL and a correlated but distinct subgroup factor for participation. Several model fit indexes and reliability coefficients, such as explained common variance (ECV) and omegas were computed for both models. Results The first model fitted the data well, but the reliability analysis indicated multidimensionality and unique information in the subgroup factor participation. The second model showed similar model fits, but better reliability; ECV = 0.67, omega-t = 0.94, low omega-s = 0.18-0.22 on the subgroup factors and high omega of 0.82 on participation, which all were in favour of the second model. Conclusions The results indicate that PF, ADL and IADL could be aggregated into one general measure of functioning, whereas participation should be considered as a distinct measure. PMID:24192234

  7. 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

  8. 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

  9. 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. PMID:26640032

  10. 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

  11. Self-aggregation and liquid crystalline behavior of new ester-functionalized quinuclidinolium surfactants.

    PubMed

    Bhadani, Avinash; Endo, Takeshi; Koura, Setsuko; Sakai, Kenichi; Abe, Masahiko; Sakai, Hideki

    2014-08-01

    A new type of ester-based cationic surfactant having a quinuclidinolium headgroup has been synthesized starting from linear fatty alcohols and has been characterized using spectroscopic techniques. The self-aggregation and thermodynamic properties of these surfactants have been investigated by pendant-drop surface tensiometry and conductivity measurements. The liquid crystalline behaviors of these surfactants were investigated by small-angle X-ray scattering (SAXS) technique. The quinuclidinolium headgroup demonstrated a unique ability to interlock among themselves thus affecting the physicochemical properties of surfactants in aqueous solution. The current research finding supports the new concept of headgroup interlocking which is supported by 1D and 2D NMR studies. PMID:25058797

  12. Valorisation of different types of boron-containing wastes for the production of lightweight aggregates.

    PubMed

    Kavas, T; Christogerou, A; Pontikes, Y; Angelopoulos, G N

    2011-01-30

    Four boron-containing wastes (BW), named as Sieve (SBW), Dewatering (DBW), Thickener (TBW) and Mixture (MBW) waste, from Kirka Boron plant in west Turkey were investigated for the formation of artificial lightweight aggregates (LWA). The characterisation involved chemical, mineralogical and thermal analyses as well as testing of their bloating behaviour by means of heating microscopy. It was found that SBW and DBW present bloating behaviour whereas TBW and MBW do not. Following the above results two mixtures M1 and M2 were prepared with (in wt.%): 20 clay mixture, 40 SBW, 40 DBW and 20 clay mixture, 35 SBW, 35 DBW, 10 quartz sand, respectively. Two different firing modes were applied: (a) from room temperature till 760 °C and (b) abrupt heating at 760 °C. The obtained bulk density for M1 and M2 pellets is 1.2g/cm(3) and 0.9 g/cm(3), respectively. The analysis of microstructure with electron microscopy revealed a glassy phase matrix and an extended formation of both interconnected and isolated, closed pores. The results indicate that SBW and DBW boron-containing wastes combined with a clay mixture and quartz sand can be valorised for the manufacturing of lightweight aggregates. PMID:21075514

  13. 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...

  14. 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...

  15. 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

    2016-01-01

    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

  16. Utilization of Illinois slags for the production of ultra-lightweight aggregates. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Choudhry, V.; Zimmerle, T.; Banerjee, D.D.

    1993-05-01

    The objective of this program is to demonstrate that solid residues (slag) from the gasification of Illinois coals can be utilized to manufacture ultra-lightweight aggregates (ULWA). Conventional ULWAs are made by pyroprocessing perlite ores and have unit weights in the range of 3--15 lb/ft{sup 3}. In a previous project, Praxis Engineers demonstrated at the pilot scale that lightweight aggregates with unit weights of 40--55 lb/ ft{sup 3} can be produced from Illinois coal slags, which is suitable for making lightweight cement concrete and precast blocks. These tests also indicated that a product with a unit weight of less than 25 lb/ft{sup 3} could be produced from slag. This project is aimed at testing the potential for producing ULWA from Illinois coal slags. Target applications include loose fill insulation, insulating concrete, lightweight precast products such as concrete blocks and rooftiles, and filtration media. Laboratory- and pilot-scale testing is being conducted in Phase I to identify operating conditions for the expansion of Illinois slags to produce ULWA. Following this, a large batch of expanded slag will be produced, for evaluation in various applications in Phase II.

  17. 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. PMID:27128715

  18. Butanol extract of Ecklonia cava prevents production and aggregation of beta-amyloid, and reduces beta-amyloid mediated neuronal death.

    PubMed

    Kang, Il-Jun; Jeon, Young Eun; Yin, Xing Fu; Nam, Jin-Sik; You, Sang Guan; Hong, Myo Soon; Jang, Bong Geom; Kim, Min-Ju

    2011-09-01

    Beta-amyloid (Aβ) is a major pathogenic peptide for Alzheimer's disease (AD) and is generated by the processing of amyloid precursor protein (APP). The Aβ monomers aggregate into oligomeric and fibrillar forms which have been implicated as the toxic species inducing the neuronal dysfunction. Brown algae Ecklonia cava is known for its anti-oxidant and anti-inflammatory functions. Therefore, we tested the effect of E. cava extract on the production and aggregation of Aβ peptides. The butanol extract of E. cava reduced Aβ secretion from HEK293 cells expressing APP with Swedish mutation and increased soluble APPα and C-terminal fragment-α (CTFα), of which activity was similar to BACE (β-site of APP cleaving enzyme) inhibitors. Furthermore, the extract inhibited Aβ oligomerization, particularly mid-size oligomer formation, confirmed by the ultrastructural morphology. Congo red, thioflavin T assays, and electron microscopy showed that the extract inhibited Aβ fibril formation effectively. Finally, the extract protected primary cortical neurons from various Aβ-induced cell deaths, especially oligomer-induced death. Although further study is needed to test the effectiveness of the extract in vivo, our results demonstrate, for the first time, that the butanol extract of E. cava could be used as an anti-Aβ agent for AD therapeutics. PMID:21693162

  19. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions.

    PubMed

    Crosby, H A; Kwiecinski, J; Horswill, A R

    2016-01-01

    The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion. PMID:27565579

  20. 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.

  1. Self-Assembly of Amphiphilic Anthracene-Functionalized β-Cyclodextrin (CD-AN) through Multi-Micelle Aggregation.

    PubMed

    Zhang, Yuannan; Xu, Hongjie; Ma, Xiaodong; Shi, Zixing; Yin, Jie; Jiang, Xuesong

    2016-06-01

    Multi-micelle aggregation (MMA) mechanism is widely acknowledged to explicate large spherical micelles self-assembly, but the process of MMA during self-assembly is hard to observe. Herein, a novel kind of strong, regular microspheres fabricated from self-assembly of amphiphilic anthracene-functionalized β-cyclodextrin (CD-AN) via Cu(I)-catalyzed azide-alkyne click reactions is reported. The obtained CD-AN amphiphiles can self-assemble in water from primary core-shell micelles to secondary aggregates with the diameter changing from several tens nm to around 600-700 nm via MMA process according to the images of scanning electron microscopy, transmission electron microscopy, and atomic force microscopy as well as the dynamic light scattering measurements, followed by further crosslinking through photo-dimerization of anthracene. What merits special attention is that such photo-crosslinked self-assemblies are able to disaggregate reversibly into primary nanoparticles when changing the solution conditions, which is benefited from the designed regular structure of CD-AN and the rigid ranging of anthracene during assembly, thus confirming the process of MMA. PMID:27145434

  2. Probe Intracellular Trafficking of a Polymeric DNA Delivery Vehicle by Functionalization with an Aggregation-Induced Emissive Tetraphenylethene Derivative.

    PubMed

    Han, Xiongqi; Chen, Qixian; Lu, Hongguang; Ma, Jianbiao; Gao, Hui

    2015-12-30

    Characteristic aggregation-induced quenching of π-fluorophores imposed substantial hindrance to their utilization in nanomedicine for insight into microscopic intracellular trafficking of therapeutic payload. To address this obstacle, we attempted to introduce a novel aggregation-induced emission (AIE) fluorophore into the cationic polymer, which was further used for formulation of a gene delivery carrier. Note that the selective restriction of the intramolecular rotation of the AIE fluorophore through its covalent bond to the polymer conduced to immense AIE. Furthermore, DNA payload labeled with the appropriate fluorophore as the Förster resonance energy transfer (FRET) acceptor verified a facile strategy to trace intracellular DNA releasing activity relying on the distance limitation requested by FRET (AIE fluorophore as FRET donor). Moreover, the hydrophobic nature of the AIE fluorophore appeared to promote colloidal stability of the constructed formulation. Together with other chemistry functionalization strategies (including endosome escape), the ultimate formulation exerted dramatic gene transfection efficiency. Hence, this report manifested a first nanomedicine platform combining AIE and FRET for microscopic insight into DNA intracellular trafficking activity. PMID:26634294

  3. 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. PMID:23801276

  4. 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

  5. Designed Stem Cell Aggregates: Enhanced Biological Functions of Human Mesenchymal Stem-Cell Aggregates Incorporating E-Cadherin-Modified PLGA Microparticles (Adv. Healthcare Mater. 15/2016).

    PubMed

    Zhang, Yan; Mao, Hongli; Gao, Chao; Li, Suhua; Shuai, Qizhi; Xu, Jianbin; Xu, Ke; Cao, Lei; Lang, Ren; Gu, Zhongwei; Akaike, Toshihiro; Yang, Jun

    2016-08-01

    E-cadherin-modified poly(lactic-co-glycolic acid) (hE-cad-PLGA) microparticles were fabricated and then mediated the 3D cell aggregates of human mesenchymal stem cells (MSCs) on page 1949 by Jun Yang and co-workers. The hE-cad-Fc matrix and the PLGA microparticles synergistically regulate the proliferation and bioactive factors secretions of MSCs by activating EGFR, AKT and ERK1/2 signaling pathways. The hE-cad-PLGA microparticles offer a novel route to expand multipotent stem cell-based clinical applications. PMID:27511954

  6. Functional roles of aggregation-promoting-like factor in stress tolerance and adherence of Lactobacillus acidophilus NCFM.

    PubMed

    Goh, Yong Jun; Klaenhammer, Todd R

    2010-08-01

    Aggregation-promoting factors (Apf) are secreted proteins that have been associated with a diverse number of functional roles in lactobacilli, including self-aggregation, the bridging of conjugal pairs, coaggregation with other commensal or pathogenic bacteria, and maintenance of cell shape. In silico genome analysis of Lactobacillus acidophilus NCFM identified LBA0493 as a 696-bp apf gene that encodes a putative 21-kDa Apf protein. Transcriptional studies of NCFM during growth in milk showed apf to be one of the most highly upregulated genes in the genome. In the present study, reverse transcriptase-quantitative PCR (RT-QPCR) analysis revealed that the apf gene was highly induced during the stationary phase compared to that during the logarithmic phase. To investigate the functional role of Apf in NCFM, an Delta apf deletion mutant was constructed. The resulting Delta apf mutant, NCK2033, did not show a significant difference in cell morphology or growth compared to that of the NCFMDelta upp reference strain, NCK1909. The autoaggregation phenotype of NCK2033 in planktonic culture was unaffected. Additional phenotypic assays revealed that NCK2033 was more susceptible to treatments with oxgall bile and sodium dodecyl sulfate (SDS). Survival rates of NCK2033 decreased when stationary-phase cells were exposed to simulated small-intestinal and gastric juices. Furthermore, NCK2033 in the stationary phase showed a reduction of in vitro adherence to Caco-2 intestinal epithelial cells, mucin glycoproteins, and fibronectin. The data suggest that the Apf-like proteins may contribute to the survival of L. acidophilus during transit through the digestive tract and, potentially, participate in the interactions with the host intestinal mucosa. PMID:20562289

  7. Contribution of chronic conditions to aggregate changes in old-age functioning.

    PubMed Central

    Freedman, V A; Martin, L G

    2000-01-01

    OBJECTIVES: This study explored the role of various chronic conditions in explaining recent improvements in functioning among older Americans. METHODS: We used the Supplements on Aging to the 1984 and 1994 National Health Interview Surveys to examine changes among Americans 70 years and older in reports of chronic conditions and functional limitations. We decomposed functioning changes into condition-related components, controlling for demographic shifts. RESULTS: The percentage of older Americans with upper- and lower-body limitations declined from 5.1% and 34.2%, respectively, in 1984 to 4.3% and 28.5% in 1995, and the average number of lower body limitations decreased. During the same period, reports of 8 of 9 chronic conditions increased, but many of these conditions had less debilitating effects on functioning. Reductions in the debilitating effects of various chronic conditions--particularly arthritis--are important in explaining declines in limitations experienced by older Americans. CONCLUSIONS: Earlier diagnosis and improved treatment and management of chronic conditions, rather than prevention, may be important contributing factors to improvements in upper- and lower-body functioning among older Americans. PMID:11076245

  8. The structure of human SFPQ reveals a coiled-coil mediated polymer essential for functional aggregation in gene regulation

    PubMed Central

    Lee, Mihwa; Sadowska, Agata; Bekere, Indra; Ho, Diwei; Gully, Benjamin S.; Lu, Yanling; Iyer, K. Swaminathan; Trewhella, Jill; Fox, Archa H.; Bond, Charles S.

    2015-01-01

    SFPQ, (a.k.a. PSF), is a human tumor suppressor protein that regulates many important functions in the cell nucleus including coordination of long non-coding RNA molecules into nuclear bodies. Here we describe the first crystal structures of Splicing Factor Proline and Glutamine Rich (SFPQ), revealing structural similarity to the related PSPC1/NONO heterodimer and a strikingly extended structure (over 265 Å long) formed by an unusual anti-parallel coiled-coil that results in an infinite linear polymer of SFPQ dimers within the crystals. Small-angle X-ray scattering and transmission electron microscopy experiments show that polymerization is reversible in solution and can be templated by DNA. We demonstrate that the ability to polymerize is essential for the cellular functions of SFPQ: disruptive mutation of the coiled-coil interaction motif results in SFPQ mislocalization, reduced formation of nuclear bodies, abrogated molecular interactions and deficient transcriptional regulation. The coiled-coil interaction motif thus provides a molecular explanation for the functional aggregation of SFPQ that directs its role in regulating many aspects of cellular nucleic acid metabolism. PMID:25765647

  9. 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

  10. Intrafamilial aggregation and heritability of tissue Doppler indexes of left ventricular diastolic function in a group of African descent.

    PubMed

    Peterson, Vernice R; Norton, Gavin R; Libhaber, Carlos D; Maseko, Muzi J; Sareli, Pinhas; Woodiwiss, Angela J

    2016-06-01

    Although several indexes of left ventricular (LV) diastolic function show heritability, the genetic influence on the tissue Doppler index, E/e' (early transmitral velocity/velocity of myocardial tissue lengthening), an index of LV filling pressures in those of black African descent is currently unknown. Furthermore, whether any genetic influences on E/e' are through an impact of LV remodeling or aortic function is unknown. Intrafamilial aggregation and heritability (SAGE software) of E/e' (echocardiography) were assessed in 129 nuclear families (29 spouse pairs, 216 parent-child pairs, and 113 sibling-sibling pairs) from an urban developing community of black Africans, independent of LV mass index (LVMI), LV relative wall thickness (RWT), central aortic systolic pressure (SBPc), and backward wave pressures (Pb) (applanation tonometry, SphygmoCor software). Independent of confounders including LVMI and RWT, E/e' was correlated in parent-child (r = 0.23; P < .001) and sibling-sibling (r = 0.29; P < .005), but not in spouse (r = 0.13; P = .51) pairs. The relationships between parent-child (r = 0.22; P < .001) and sibling-sibling (r = 0.29; P < .005) pairs persisted with adjustments for SBPc. The relationships between parent-child (r = 0.22; P < .001) and sibling-sibling (r = 0.26; P < .01) pairs also persisted with adjustments for Pb. Independent of confounders including LVMI and RWT, E/e' showed significant heritability (h(2) ± standard error of the mean [SEM] = 0.51 ± 0.11; P < .0001) which similarly persisted with adjustments for SBPc (h(2) ± SEM = 0.50 ± 0.11; P < .0001) and Pb (h(2) ± SEM = 0.49 ± 0.11; P < .0001). In conclusion, in a group of African ancestry, independent of LV remodeling and aortic function, E/e' shows significant intrafamilial aggregation and robust heritability. Hence, genetic factors may play an important role in determining moderate-to-severe LV diastolic dysfunction independent of

  11. A modular approach towards functional supramolecular aggregates - subtle structural differences inducing liquid crystallinity.

    PubMed

    Pfletscher, Michael; Wölper, Christoph; Gutmann, Jochen S; Mezger, Markus; Giese, Michael

    2016-06-30

    Herein we report an efficient modular approach to supramolecular functional materials. Hierarchical self-assembly of azopyridine derivatives and hydrogen-bond donors yielded discotic assemblies. Subtle differences in the core units introduced mesomorphic behaviour and fast photo-response of the liquid crystals based on phloroglucinol. The presented results prove the benefits of a modular methodology towards highly responsive materials with tailor-made properties. PMID:27314613

  12. Acquisition and aggregation of canine blood platelets: basic mechanisms of function and differences because of breed origin.

    PubMed

    Clemmons, R M; Meyers, K M

    1984-01-01

    A method for obtaining reliable blood platelet yields in canine platelet-rich plasma, using increased sodium citrate concentration, is presented. Maintaining a quiet environment or anesthetizing the animals with thiamylal sodium aids in collection of platelets. Aggregation of platelets from 60 dogs of various breeds in response to arachidonic acid, collagen, adenosine diphosphate, epinephrine, and serotonin was monitored. Canine platelets reversibly or irreversibly aggregated to arachidonic acid. The percentage of arachidonate-irreversible platelets varied from 0% to 100% depending upon the breed of dogs examined. Arachidonate-irreversible platelets also aggregated irreversibly at lower concentrations of collagen and exhibited biphasic irreversible aggregation to adenosine diphosphate and serotonin. Serotonin-induced irreversible aggregation was dependent upon receptor activation and upon arachidonic acid metabolism. Irreversible aggregation to serotonin was associated with release of 3H-serotonin and thromboxane B2 formation, indicating that a couple between the serotonergic receptor and arachidonic acid metabolism may exist. PMID:6422804

  13. Aggregate Fission-Product Decay Data Based on ENDF/B-IV and -V.

    1982-10-12

    Version 02 The ENDF/B-IV fission-product files contain neutron cross sections, decay constants, decay energies, and other decay data for 824 important fission products. They also contain fission yields for these fission products produced by one or more fission-neutron energies (14 MeV, fast, and thermal fission). Also, spectral data exist for the most important decay-heat contributors among the 824 nuclides. Because the spectra are based on fission pulses, the libraries have a general utility. The exponentialmore » fits, for example, can be folded into any power (fission) history that can be described analytically or by a histogram representation. The effects of neutron absorption are also treated and approximately accounted for in the methodology.« less

  14. 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

  15. 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

  16. Lyn and PECAM-1 function as interdependent inhibitors of platelet aggregation.

    PubMed

    Ming, Zhangyin; Hu, Yu; Xiang, Jizhou; Polewski, Peter; Newman, Peter J; Newman, Debra K

    2011-04-01

    Inhibition of platelet responsiveness is important to control pathologic thrombus formation. Platelet-endothelial cell adhesion molecule-1 (PECAM-1) and the Src family kinase Lyn inhibit platelet activation by the glycoprotein VI (GPVI) collagen receptor; however, it is not known whether PECAM-1 and Lyn function in the same or different inhibitory pathways. In these studies, we found that, relative to wild-type platelets, platelets derived from PECAM-1-deficient, Lyn-deficient, or PECAM-1/Lyn double-deficient mice were equally hyperresponsive to stimulation with a GPVI-specific agonist, indicating that PECAM-1 and Lyn participate in the same inhibitory pathway. Lyn was required for PECAM-1 tyrosine phosphorylation and subsequent binding of the Src homology 2 domain-containing phosphatase-2, SHP-2. These results support a model in which PECAM-1/SHP-2 complexes, formed in a Lyn-dependent manner, suppress GPVI signaling. PMID:21297004

  17. 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. PMID:12837258

  18. 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.

  19. 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

  20. The effect of time of day and exercise on platelet functions and platelet-neutrophil aggregates in healthy male subjects.

    PubMed

    Aldemir, Hatice; Kiliç, Nedret

    2005-12-01

    Platelet activation state changes by exercise. The effect of exercise time on platelet activation state and formation of platelet-neutrophil aggregates are not known yet. In this study the effect of exercise and time of day were examined on platelet activity with platelet-neutrophil aggregates. Ten moderately active males aged 27+/- 1.63 (mean+/-S.D.) years completed sub-maximal (70% VO(2max)) exercise trials for 30 min. Blood pressure (BP) was recorded. Venous blood samples were obtained at rest, immediately post-exercise and after 30 min of recovery. Whole blood was analysed for haematocrit (Hct), haemoglobin (Hb), platelet count (PC), mean platelet count (MPV) and platelet aggregation (PA). Platelet-neutrophil aggregates and beta-thromboglobulin (beta-TG) levels were assayed. Platelet count showed significant increase after morning exercise ((236+/- 32)x10(9) l(-1) versus (202+/- 34)x10(9) l(-1) baseline, p < 0.05). Exercise resulted in significantly lower MPV after the evening exercise (9.16+/- 0.5 fl versus 9.65+/- 0.36 fl, p < 0.05). Platelet aggregation by adenosine diphosphate (ADP) decreased after morning exercise and the recovery aggregation levels were significantly different at two different times of the day (68+/- 20% a.m. versus 80+/- 12% p.m., p < 0.05). It was also showed that platelet-neutrophil aggregates increased significantly from baseline after both exercises. Exercise-induced platelet-neutrophil aggregates were higher in the evening (10.7+/- 1.3% p.m. versus 6.4+/- 1.8% a.m., p < 0.0001). It is therefore concluded that besides platelet-platelet aggregation, exercise can cause platelet- neutrophil aggregates. In addition, time of day has an effect on platelet activation related events. Circadian variations of physiological parameters may have an effect on thrombus formation by platelet activation. PMID:16311912

  1. Synthesis of cinnolines via Rh(iii)-catalysed dehydrogenative C-H/N-H functionalization: aggregation induced emission and cell imaging.

    PubMed

    Mayakrishnan, Sivakalai; Arun, Yuvaraj; Balachandran, Chandrasekar; Emi, Nobuhiko; Muralidharan, Doraiswamy; Perumal, Paramasivan Thirumalai

    2016-02-14

    Rhodium catalysed dehydrogenative C-H/N-H functionalization was developed to construct phthalazino[2,3-a]-/indazolo[1,2-a]cinnolines by reacting N-phenyl phthalazine/indazole with alkynes. The synthesized compounds exhibit prominent fluorescence properties in solid and aggregation states. Their application in cell imaging was investigated using various cancer cell lines. PMID:26754143

  2. Aggregate dermal exposure to cyclic siloxanes in personal care products: implications for risk assessment.

    PubMed

    Biesterbos, Jacqueline W H; Beckmann, Gwendolyn; van Wel, Luuk; Anzion, Rob B M; von Goetz, Natalie; Dudzina, Tatsiana; Roeleveld, Nel; Ragas, Ad M J; Russel, Frans G M; Scheepers, Paul T J

    2015-01-01

    Consumers who use personal care products (PCPs) are internally exposed to some of the organic components present of which some may be detected in exhaled air when eliminated. The aim of this study was the quantitative determination of octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in end-exhaled air to study dermal absorption of substances in PCPs. We exposed the forearm of fifteen healthy volunteers for 60min to pure D4 or D5 and to commercial products containing D4 and D5. Inhalation uptake was kept to a minimum by keeping the forearm in a flow cabinet during dermal exposure and supplying filtered air to the breathing zone of the volunteer during the post-exposure period. End-exhaled air was collected using a breath sampler (Bio-VOC), transferred to carbograph multi-bed adsorbent tubes and analyzed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS). In the end-exhaled air of non-exposed volunteers background concentrations of D4 (0.8-3.5ng/L) and D5 (0.8-4.0ng/L) were observed. After exposing the volunteers, the level of D4 and D5 in end-exhaled air did not or barely exceed background concentrations. At t=90min, a sharp increase of the D4/D5 concentration in end-exhaled air was observed, which we attributed to the inhalation of the substances during a toilet visit without using inhalation protection devices. When this visit was taken out of the protocol, the sharp increase disappeared. Overall, the results of our study indicate that dermal absorption of D4 and D5 contributes only marginally to internal exposure following dermal applications. As in our study inhalation is the primary route of entry for these compounds, we conclude that its risk assessment should focus on this particular exposure route. PMID:25454240

  3. 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

  4. 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

  5. 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. PMID:25977062

  6. 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.

  7. 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

  8. Water Production Functions for Central Plains Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustaining irrigated agriculture with limited water supplies requires maximizing productivity per unit of water. Relationships between crop production and water consumed are basic information required to maximize productivity. This information can be used to determine if deficit irrigation is eco...

  9. Water Production Function For Central Plains Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustaining irrigated agriculture with limited water supplies requires maximizing productivity per unit of water. Relationships between crop production and water consumed are basic information required to maximize productivity. This information can be used to determine if deficit irrigation is econ...

  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. PMID:26107291

  11. Weighted aggregation

    NASA Technical Reports Server (NTRS)

    Feiveson, A. H. (Principal Investigator)

    1979-01-01

    The use of a weighted aggregation technique to improve the precision of the overall LACIE estimate is considered. The manner in which a weighted aggregation technique is implemented given a set of weights is described. The problem of variance estimation is discussed and the question of how to obtain the weights in an operational environment is addressed.

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

    PubMed

    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

  13. 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

  14. Diel Rhythms in Monochamus (Coleoptera: Cerambycidae): Production of and Response to a Male-Produced Aggregation Pheromone.

    PubMed

    Skabeikis, D D; Teale, S A; Fierke, M K

    2016-08-01

    Recent research has shown that several species in the genus Monochamus, including Monochamus scutellatus scutellatus (Say) and Monochamus notatus (Drury), a close congener, are attracted to an aggregation pheromone, monochamol, but only M. s. scutellatus produces it. Investigations were conducted to determine if there is a diel rhythm in production of monochamol or response to monochamol + host attractants in field trials by M. s. scutellatus and M. notatus to prevent cross attraction with each other. Volatiles were collected from males and females of M. s. scutellatus and M. notatus every 8 h and analyzed by coupled gas chromatography-mass spectrometry. Traps baited with monochamol and the host volatiles α-pinene and ethanol were checked every 8 h in field tests. Only male M. s. scutellatus produced the pheromone, and did so in similar quantities during each 8-h time interval assessed, suggesting there is no diel rhythm in pheromone production. In field tests conducted in early to mid-July, significantly more M. s. scutellatus were captured during morning hours, and significantly more M. notatus were caught during afternoon or early evening hours, suggesting temporal partitioning of flight or in their response to the pheromone lures when both species are present. A temporal switch occurred later in the seasonal flight period (mid-August) when densities of M. s. scutellatus were low; all M. notatus and only one M. s. scutellatus were caught during morning hours. This suggests a temporal separation in mate location behavior when both species are abundant and using the same host to avoid interspecific mating. PMID:27252408

  15. Inhibition of whole blood platelet-aggregation by compounds in garlic clove extracts and commercial garlic products.

    PubMed

    Lawson, L D; Ransom, D K; Hughes, B G

    1992-01-15

    The inhibitory effects of adenosine and 16 quantitatively determined organosulfur compounds derived from garlic cloves or commercial garlic preparations on collagen stimulated in vitro platelet aggregation in whole blood were determined. An estimation of the anti-aggregatory activity of several brands of the major types of commercial garlic preparations was determined from the activities of the individual compounds present in each sample. In platelet rich plasma (PRP) most of the anti-aggregatory activity of garlic clove homogenates was due to adenosine; however, in whole blood neither adenosine nor the polar fraction had any effect and all of the anti-aggregatory activity was due to allicin and other thiosulfinates. Allicin was equally active in whole blood and PRP. Among brands there was a several-fold variation in content of the organosulfur compounds and activity for all types of garlic products tested. The best garlic powder tablets were equally as active as clove homogenates whereas steam-distilled oils were 35% as active and oil-macerates (due to low content) only 12% as active. A garlic product aged many months in aqueous alcohol had no activity. For steam-distilled oils, most of the activity was due to diallyl trisulfide. For the oil-macerates, most of the activity was due largely to the vinyl dithiins. Ajoene, an exclusive component of the oil-macerates, had highest specific activity of all the compounds tested but, because of its low concentration, had only 13% of the activity of diallyl trisulfide and 3% of the activity of allicin. Compounds which may be active in vivo are discussed. PMID:1579891

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

    PubMed

    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

  17. 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.

  18. 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.

  19. 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. PMID:27373154

  20. 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

  1. Thermoresponsive behavior of micellar aggregates from end-functionalized PnBA-b-PNIPAM-COOH block copolymers and their complexes with lysozyme.

    PubMed

    Papagiannopoulos, Aristeidis; Meristoudi, Anastasia; Pispas, Stergios; Keiderling, Uwe

    2016-08-21

    The temperature response of micellar aggregates of poly(n-butyl acrylate)-b-poly(N-isopropylacrylamide)-carboxylic acid (PnBA-b-PNIPAM-COOH) end-functionalized diblock copolymers in aqueous solutions is investigated by small angle neutron scattering and light scattering techniques. The particular micellar aggregates present -COOH groups at their surface due to the molecular architecture of the block copolymer chains. Above the critical solution temperature micellar aggregation depends on the initial solution concentration, while at the highest polymer content intermicellar correlations are observed as a hard-sphere interaction intensity peak. Addition of lysozyme induces this morphological transition even at low concentrations. The scattering profiles are consistent with lysozyme accumulating in the vicinity of the micellar cores, a finding that is supported by measurements in lysozyme contrast matched solvent. Upon temperature increase negatively charged units are exposed to the surface of the aggregates during thermal transition which is a stabilizing force against the phase separating coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM). PMID:27426110

  2. Molecular dissection of SO (SOFT) protein in stress-induced aggregation and cell-to-cell interactive functions in filamentous fungal multicellularity.

    PubMed

    Tsukasaki, Wakako; Saeki, Kei; Katayama, Takuya; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2016-05-01

    Filamentous fungi grow by organizing multicellularity through hyphal compartmentalization and cell fusion. SO (SOFT) protein, which was originally identified in Neurospora crassa, plays distinct functional roles in cell-to-cell interactions, such as septal plugging and cell fusion. We previously reported that AoSO, an Aspergillus oryzae SO homologue, forms aggregates at the septal pore in response to stress, as well as upon hyphal wounding. However, the functional regions that mediate the multicellular functions of AoSO, which is a large protein composed of 1195 amino acids, have not been elucidated. Here, we divided AoSO protein into regions according to amino acid sequence conservation among other fungal SO homologues. By heterologous expression of full-length and truncated forms of AoSO in the yeast Saccharomyces cerevisiae, the region responsible for the stress-induced aggregation of AoSO was identified to be between amino acids 556 and 1146. In A. oryzae, however, septal localization of AoSO aggregates required the 49 C-terminal amino acids. Thus, expression of only the C-terminal half of AoSO was sufficient for septal plugging and prevention of excessive cytoplasmic loss upon hyphal wounding. In contrast, the N-terminal half of AoSO, from amino acids 1 to 555, together with the C-terminal end, was revealed to be indispensable for cell fusion. Collectively, these findings suggest that the C-terminal half of AoSO, which mediates stress-induced aggregation, is required for both septal plugging and cell fusion, whereas the N-terminal half confers an additional functionality that is essential for cell fusion. PMID:27109373

  3. 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.

  4. Canonical Estimation of Joint Educational Production Functions.

    ERIC Educational Resources Information Center

    Chizmar, John F.; Zak, Thomas A.

    1984-01-01

    This article views learning and attitude formation within the context of joint production. Tables show summary statistics and estimated marginal products and rates for each output. These estimates reveal trade-offs within the learning process that differ for men and women. (PB)

  5. Production of viable cloned miniature pigs by aggregation of handmade cloned embryos at the 4-cell stage.

    PubMed

    Siriboon, Chawalit; Tu, Ching-Fu; Kere, Michel; Liu, Ming-Sing; Chang, Hui-Jung; Ho, Lin-Lin; Tai, Miao-En; Fang, Wen-Der; Lo, Neng-Wen; Tseng, Jung-Kai; Ju, Jyh-Cherng

    2014-03-01

    The aim of the present study was to improve the quality of handmade cloned porcine embryos by multiple embryo aggregations. Embryos derived from aggregation of three cloned embryos (3×) had a better blastocyst rate than cloned control (1×) embryos (73.6% vs 35.1%, respectively; P<0.05), but did not differ from those produced by aggregation of two cloned embryos (2×; 63.0%). Total cell numbers differed among treatments (P<0.05), with the greatest cell numbers (126) in the 3× group and the lowest (55) in the control group. The ratio of inner cell mass:total cell number was comparable in the 2× and 3× groups (25.1% vs 26.1%, respectively) and was significantly better than that in the control group (15.3%). The proportion of apoptotic cells in 2× and 3× groups was lower than that in the control group (2.7% and 2.2% vs 4.7%, respectively; P<0.05). Expression of Oct4 and Cdx2 was higher, whereas that of Bax was lower (P<0.05), in the 3× compared with non-aggregate group. Seven piglets were born to two surrogate mothers after embryo transfer of 3× aggregated blastocysts. In conclusion, aggregated embryos had greater total cell numbers and better pluripotency gene expression, with reduced expression of the pro-apoptosis gene Bax. Collectively, these improvement may be associated with the development of cloned embryos to term. PMID:23544704

  6. [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. PMID:18154178

  7. Aggregation Induced Emission Mediated Controlled Release by Using a Built-In Functionalized Nanocluster with Theranostic Features.

    PubMed

    Zhou, Zhan; Zhang, Cheng Cheng; Zheng, Yuhui; Wang, Qianming

    2016-01-14

    We report biological evaluation of a novel nanoparticle delivery system based on 1,1,2-triphenyl-2-(p-hydroxyphenyl)-ethene (TPE-OH, compound 1), which has tunable aggregation-induced emission (AIE) characteristics. Compound 1 exhibited no emission in DMSO. In aqueous media, compound 1 aggregated, and luminescence was observed. The novel membrane-cytoplasm-nucleus sequential delivery strategy could induce apoptosis in four different kinds of cancer cells (including three adherent cell lines and one suspension cell line). The nanoparticles remained in the cytoplasm with intense blue emissions, whereas doxorubicin was observed in the nucleus with striking red luminescence. The nanoassembly was internalized in cells through an energy-dependent process. Three sorts of chemical inhibitors were used to clarify the endocytosis mechanism based on the AIE type prodrug. Furthermore, we have developed the first AIE theranostic system where drug targeting and release have been applied in an animal model. PMID:26689502

  8. Computational Studies of Protein Aggregation: Methods and Applications

    NASA Astrophysics Data System (ADS)

    Morriss-Andrews, Alex; Shea, Joan-Emma

    2015-04-01

    Protein aggregation involves the self-assembly of normally soluble proteins into large supramolecular assemblies. The typical end product of aggregation is the amyloid fibril, an extended structure enriched in β-sheet content. The aggregation process has been linked to a number of diseases, most notably Alzheimer's disease, but fibril formation can also play a functional role in certain organisms. This review focuses on theoretical studies of the process of fibril formation, with an emphasis on the computational models and methods commonly used to tackle this problem.

  9. 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...

  10. Production of aggregation prone human interferon gamma and its mutant in highly soluble and biologically active form by SUMO fusion technology.

    PubMed

    Tileva, M; Krachmarova, E; Ivanov, I; Maskos, K; Nacheva, G

    2016-01-01

    The Escherichia coli expression system is a preferable choice for production of recombinant proteins. A disadvantage of this system is the target protein aggregation in "inclusion bodies" (IBs) that further requires solubilisation and refolding, which is crucial for the properties and the yield of the final product. In order to prevent aggregation, SUMO fusion tag technology has been successfully applied for expression of eukaryotic proteins, including human interferon gamma (hIFNγ) that was reported, however, with no satisfactory biological activity. We modified this methodology for expression and purification of both the wild type hIFNγ and an extremely prone to aggregation mutant hIFNγ-K88Q, whose recovery from IBs showed to be ineffective upon numerous conditions. By expression of the N-terminal His-SUMO fusion proteins in the E. coli strain BL21(DE3)pG-KJE8, co-expressing two chaperone systems, at 24 °C a significant increase in solubility of both target proteins (1.5-fold for hIFNγ and 8-fold for K88Q) was achieved. Two-step chromatography (affinity and ion-exchange) with on-dialysis His-SUMO-tag cleavage was applied for protein purification that yielded 6.0-7.0mg/g wet biomass for both proteins with >95% purity and native N-termini. The optimised protocol led to increased yields from 5.5 times for hIFNγ up to 100 times for K88Q in comparison to their isolation from IBs. Purified hIFNγ showed preserved thermal stability and antiproliferative activity corresponding to that of the native reference sample (3 × 10(7)IU/mg). The developed methodology represents an optimised procedure that can be successfully applied for large scale expression and purification of aggregation-prone proteins in soluble native form. PMID:26407523

  11. Hepatic production of transthyretin L12P leads to intracellular lysosomal aggregates in a new somatic transgenic mouse model.

    PubMed

    Batista, Ana Rita; Sena-Esteves, Miguel; Saraiva, Maria João

    2013-08-01

    Transthyretin (TTR) is a plasma and cerebrospinal fluid (CSF)-circulating homotetrameric protein. More than 100 point mutations have been identified in the TTR gene and several are related with amyloid diseases. Here we focused our attention in the TTR L12P variant associated with severe peripheral neuropathy and leptomeningeal amyloidosis. By using different cell lines derived from tissues specialized on TTR synthesis, such as the hepatocyte and the choroid plexus expressing WT, V30M, or L12P TTR variants we analyzed secretion, intracellular aggregation and degradation patterns. Also, we used liver-specific AAV gene transfer to assess expression of the L12P variant in vivo. We found the following: (i) decreased secretion with intracellular aggregation of TTR L12P in hepatoma cells relative to WT and V30M variant; this differential property of TTR L12P variant was also observed in mice injected with L12P AAV vector; (ii) differential N-glycosylation pattern of L12P variant in hepatoma cell lysates, conditioned media and mouse sera, which might represent an escape mechanism from ERAD degradation; (iii) intracellular L12P TTR aggregates mainly localized to lysosomes in cultured cells and liver; and (iv) none of the above findings were present in choroid plexus derived cells, suggesting particular secretion/quality control mechanisms that might contribute to leptomeningeal amyloidosis associated with the L12P variant. These observations open new avenues for the treatment of TTR associated leptomeningeal amyloidosis. PMID:23579071

  12. Microfluidic production of polymeric functional microparticles

    NASA Astrophysics Data System (ADS)

    Jiang, Kunqiang

    This dissertation focuses on applying droplet-based microfluidics to fabricate new classes of polymeric microparticles with customized properties for various applications. The integration of microfluidic techniques with microparticle engineering allows for unprecedented control over particle size, shape, and functional properties. Specifically, three types of microparticles are discussed here: (1) Magnetic and fluorescent chitosan hydrogel microparticles and their in-situ assembly into higher-order microstructures; (2) Polydimethylsiloxane (PDMS) microbeads with phosphorescent properties for oxygen sensing; (3) Macroporous microparticles as biological immunosensors. First, we describe a microfluidic approach to generate monodisperse chitosan hydrogel microparticles that can be further connected in-situ into higher-order microstructures. Microparticles of the biopolymer chitosan are created continuously by contacting an aqueous solution of chitosan at a microfluidic T-junction with a stream of hexadecane containing a nonionic detergent, followed by downstream crosslinking of the generated droplets by a ternary flow of glutaraldehyde. Functional properties of the microparticles can be easily varied by introducing payloads such as magnetic nanoparticles and/or fluorescent dyes into the chitosan solution. We then use these prepared microparticles as "building blocks" and assemble them into high ordered microstructures, i.e. microchains with controlled geometry and flexibility. Next, we describe a new approach to produce monodisperse microbeads of PDMS using microfluidics. Using a flow-focusing configuration, a PDMS precursor solution is dispersed into microdroplets within an aqueous continuous phase. These droplets are collected and thermally cured off-chip into soft, solid microbeads. In addition, our technique allows for direct integration of payloads, such as an oxygen-sensitive porphyrin dye, into the PDMS microbeads. We then show that the resulting dye

  13. Utilization of Illinois coal gasification slags for production of ultra-lightweight aggregates. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Choudhry, V.; Zimmerle, T.

    1993-09-01

    This research is aimed at testing and developing the expansion potential of gasification solid residues (slag) to manufacture ultra-lightweight aggregates (ULWA). Conventional ULWAs are manufactured by pyroprocessing of perlite or vermiculite ores and have unit weights in the range of 5--15 lb/ ft3. These materials are sold for approximately $200/ton (or $1.00/ft3) and have numerous applications including loose fill insulation, insulating concrete, precast products, filtration media, and agricultural applications. In a previous project, Praxis Engineers demonstrated that lightweight aggregates (LWA) with unit weights of 25--55 lb/ ft3 can be produced from Illinois coal slags and used as substitutes for conventional LWAs. In this program, tests are being undertaken in a pilot-scale vertical shaft furnace to identify operating conditions for the expansion of Illinois slags such that the product can be substituted for ULWA. Upon completion of testing, a large batch of expanded slag will be produced for evaluation in various applications, both in this phase and in subsequent Phase II testing. During the initial pilot plant runs using two Illinois slags, expanded products with unit weights of 12.5--26.5 and 20--52 lb/ ft3, respectively, were produced. Efforts are under way to generate products with lower unit weights.

  14. 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. PMID:26092325

  15. Diagnostics of functional state of blood by registration of light scattering intensity variations due to the reversible aggregation of red blood cells

    NASA Astrophysics Data System (ADS)

    Tukhvatulin, R. T.; Vaulin, P. P.

    1991-05-01

    A system of indicators characterizing the process of reversible aggregation of the erythrocytes (RAE) as well as method for their determination in blood microvolumes have mean elaborated. It is shown that the RAE indicators are much more informative than the conventional indicators of the blood system and more adequately reflect the changes of the functional state of blood. The deviation of RAE indicators from their standard values is a specific sign of the haemorheological disturbances. The dynamic and the correlation of the indicators of RAE variations can serve as additional diagnostic and prognostic criteria of a disease. An apparatus for the determination of RAE indicators in blood microvolumes was elaborated. 1.

  16. Influencing factors on color and product-function association.

    PubMed

    Ko, Ya-Hsien

    2011-06-01

    The associations of age, sex, and matching types with color and product-function were examined in a real-world product scenario (shampoo) among 128 volunteers (M age = 29.3 yr.; SD = 15.6). A pilot study identified eight popular colors and eight product-functions. The association between color and product-function was explored in the main sample. Responses suggested seven pairings of color/product-functions: Red/Hot oil treatment, Yellow/Bright and shiny hair, Green/Herbal extracts, Blue/Deep cleaning, Purple/Soothing, Black/Antiseptic, and White/Anti-dandruff. Analyses indicated that adult participants required more repetitions for retention, as did memorization with random pairing compared to participant-selected pairings. There were statistically significant correlations of responses to colors and product functions. With known color/product-function associations, manufacturers might promote their products more effectively. It is suggested that the associations might be sex- or culture-specific. PMID:21879633

  17. Structure and Function of Macroalgal Natural Products.

    PubMed

    Young, Ryan M; Schoenrock, Kathryn M; von Salm, Jacqueline L; Amsler, Charles D; Baker, Bill J

    2015-01-01

    Since the initial discovery of marine phyco-derived secondary metabolites in the 1950s there has been a rapid increase in the description of new algal natural products. These metabolites have multiple ecological roles as well as commercial value as potential drugs or lead compounds. With the emergence of resistance to our current arsenal of drugs as well as the development of new chemotherapies for currently untreatable diseases, new compounds must be sourced. As outlined in this chapter algae produce a diverse range of chemicals many of which have potential for the treatment of human afflictions.In this chapter we outline the classes of metabolites produced by this chemically rich group of organisms as well as their respective ecological roles in the environment. Algae are found in nearly every environment on earth, with many of these organisms possessing the ability to shape the ecosystem they inhabit. With current challenges to climate stability, understanding how these important organisms interact with their environment as well as one another might afford better insight into how they respond to a changing climate. PMID:26108497

  18. 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

  19. Evaluation of Incremental Siliconization Levels on Soluble Aggregates, Submicron and Subvisible Particles in a Prefilled Syringe Product.

    PubMed

    Bai, Shujun; Landsman, Pavel; Spencer, Andrea; DeCollibus, Daniel; Vega, Fabian; Temel, Deniz B; Houde, Damian; Henderson, Olivia; Brader, Mark L

    2016-01-01

    The evaluation of stability with respect to particles in prefilled syringes is complicated by the presence of silicone oil. The mobility, colloidal characteristics, and kinetic instability of silicone oil in contact with a protein formulation may be influenced in unpredictable ways by pharmaceutical variables, storage, and handling conditions. To provide insight into the impact of these variables on silicone oil originating specifically from the siliconized prefillable syringe (PFS), a series of studies were conducted at incremental syringe barrel siliconization levels. Size-exclusion chromatography and particle counting methods were used to quantitate soluble aggregates and submicron and subvisible particles in peginterferon beta-1a in a PFS siliconized with a fixed nozzle spray-on siliconization process. The effect of silicone oil on the peginterferon beta-1a molecule was examined under pharmaceutically relevant conditions, accelerated degradation, and under denaturing conditions. Resonant mass measurement was used to discriminate silicone oil from protein particles establishing that silicone oil does not mask adverse trends in non-silicone oil particles. The peginterferon beta-1a molecule was shown to be stable in the presence of silicone oil and robust with respect to the formation of soluble aggregates and submicron and subvisible particles in its PFS siliconized over the range of 0-1.2 mg silicone oil per syringe barrel. PMID:26852839

  20. Metabolomic investigation of the anti-platelet aggregation activity of ginsenoside Rk₁ reveals attenuated 12-HETE production.

    PubMed

    Ju, Hyun Kyoung; Lee, Jin Gyun; Park, Mi Kyung; Park, So-Jung; Lee, Chang Hoon; Park, Jeong Hill; Kwon, Sung Won

    2012-10-01

    Comprehensive metabolomics analysis is an effective method of measuring metabolite levels in the body following administration of a pharmaceutical compound and can allow for monitoring of the effects of the compound or assessment of appropriate treatment options for individual patients. In the present metabolomics study, samples pretreated with antiplatelet compounds were extracted and subjected to ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry. The acquired data were processed using peak clustering and evaluated by partial least-squares (PLS) and orthogonal projections to latent structures discriminant analyses (OPLS-DA). As a result, meaningful endogenous metabolites, namely eicosanoids and thromboxane B(2) (TXB(2)), were identified. TXB(2), a key element in platelet aggregation, was decreased upon ginsenoside Rk(1) treatment via inhibition of cyclooxygenase (COX) activity. One of the arachidonic acid (AA) metabolites, 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), was decreased significantly in the ginsenoside Rk(1)-treated platelets compared to the AA-induced group. In the mechanism study of ginsenoside Rk(1), a strong linkage to intracellular calcium levels, which induce platelet activation, was found. Additionally, the translocation of 12-LOX from cytosol to membrane, which is related with the intracellular calcium levels, was determined. Therefore, a decreased 12-HETE level induced by ginsenoside Rk(1) on antiplatelet aggregation is related to 12-LOX translocation resulting from decreased Ca(2+) levels. This study shows that global metabolomic analysis has potential for use in understanding the biological behavior of antiplatelet drugs. PMID:22873173

  1. 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...

  2. Ultrasensitive surface-enhanced Raman scattering detection of trypsin based on anti-aggregation of 4-mercaptopyridine-functionalized silver nanoparticles: an optical sensing platform toward proteases.

    PubMed

    Chen, Lingxin; Fu, Xiuli; Li, Jinhua

    2013-07-01

    In this work, a simple and sensitive surface-enhanced Raman scattering (SERS) strategy was developed for recognition and detection of trypsin, by using anti-aggregation of 4-mercaptopyridine (4-MPY)-functionalized silver nanoparticles (AgNPs) based on the interaction between protamine and trypsin. The polycationic protamine not only served as a substrate for enzyme hydrolysis but also worked as a medium for SERS enhancement, which could bind negatively charged 4-MPY-functionalized AgNPs and induce their aggregation. The hydrolysis catalyzed with trypsin in sample solution decreased the concentration of free protamine, resulting in the dispersion of AgNPs and thus decreasing the Raman intensity of 4-MPY, by which the trypsin could be sensed optically. A detection level down to 0.1 ng mL(-1) for trypsin was obtained. The induced accumulation of AgNPs modified with Raman reporter 4-MPY largely enhanced the SERS responses. A good linearity was found within the wide range over five orders of magnitude and reasonable relative standard deviations (between 2.4 and 11.6%) were attained. By using trypsin as a model, the new concept can provide an excellent platform for ultrasensitive SERS measurements of various proteases/enzymes which can lead to nanoparticles stability change through catalyzed hydrolysis toward substrate. PMID:23703031

  3. 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

  4. 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

    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

  5. Polymorphonuclear leucocyte function and previous yersinia arthritis: enhanced chemokinetic migration and oxygen radical production correlate with the severity of the acute disease.

    PubMed Central

    Koivuranta-Vaara, P; Leirisalo-Repo, M; Repo, H

    1987-01-01

    Polymorphonuclear leucocyte (PMN) functions (migration in vitro, chemiluminescence, O-2 production, binding of chemotactic peptide, and aggregation) were studied in HLA-B27 positive patients with previous yersinia arthritis (YA). PMNs of patients whose disease had been severe showed chemokinetic and chemiluminescence responses significantly higher than the PMNs of those with a mild disease. The results support the view that enhanced PMN function contributes to inflammatory symptoms in patients with YA. PMID:3592787

  6. A Modification of Lotka's Function for Scientific Productivity.

    ERIC Educational Resources Information Center

    Fang, P. H.; Fang, John M.

    1995-01-01

    Examines the validity of Lotka's function for a measurement of scientific productivity. A systematic deviation of this function from numerical examples has been found by introducing a different least-square formulation instead of a logarithmic linearization. Therefore, a modification of the measurement of the publication frequencies is proposed.…

  7. 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.

  8. Renormdynamics, multiparticle production, negative binomial distribution, and Riemann zeta function

    NASA Astrophysics Data System (ADS)

    Makhaldiani, N. V.

    2013-09-01

    After short introduction, we consider different aspects of the renormdynamics. Then scaling functions of the multiparticle production processes and corresponding stochastic dynamics are considered. Nonperturbative quasi-particle dynamics is considered on the base of the toy QCD- O( N)-sigma model. Last section concerns to the NBD-Riemann zeta function connection.

  9. Study on aggregation and electric properties in the micro-region of functionalized dithieno[2, 3-b: 3', 2'-d]thiophene (DTT) oligomers

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaohong; Huang, Xiaowei; Zhang, Jiajia; Lu, Zhijuan; Wang, Hua; Du, Zuliang

    2016-07-01

    Three kinds of 2,5,-diphenyl-dithienol[2, 3-b: 3', 2'-d]thiophene (DP-DTT), 2,5,-distyryl-dithienol[2, 3-b: 3', 2'-d]thiophene (DEP-DTT) and 2,5,-thienyl-dithienol[2, 3-b: 3', 2'-d]thiophene (DET-DTT) micro-region structure and electronic properties were studied. Thin films of these functionalized DTT oligomers were prepared in a one-step drop-casting deposition onto highly oriented pyrolytic graphite substrates. The surface structure of these films was characterized by atomic force microscopy (AFM). Conducting probe atomic force microscope (C-AFM) and Kelvin probe force microscope (KFM) were both used to characterize the electronic transport behavior and surface potential distribution. The substituents of DTT oligomers can greatly affect their aggregation and the hopping conductance mechanism was used to explain the Au-DTTs-HOPG junctions. KFM investigation revealed that these oligomers with different substituents have different highest occupied molecular orbital energy levels. The corresponding theoretical analysis reveals similar result to KFM characterization. The I-V results indicated that the aggregates of molecules were the dominating factor to their micro-region electrical transport.

  10. Immunogenicity of Therapeutic Protein Aggregates.

    PubMed

    Moussa, Ehab M; Panchal, Jainik P; Moorthy, Balakrishnan S; Blum, Janice S; Joubert, Marisa K; Narhi, Linda O; Topp, Elizabeth M

    2016-02-01

    Therapeutic proteins have a propensity for aggregation during manufacturing, shipping, and storage. The presence of aggregates in protein drug products can induce adverse immune responses in patients that may affect safety and efficacy, and so it is of concern to both manufacturers and regulatory agencies. In this vein, there is a lack of understanding of the physicochemical determinants of immunological responses and a lack of standardized analytical methods to survey the molecular properties of aggregates associated with immune activation. In this review, we provide an overview of the basic immune mechanisms in the context of interactions with protein aggregates. We then critically examine the literature with emphasis on the underlying immune mechanisms as they relate to aggregate properties. Finally, we highlight the gaps in our current understanding of this issue and offer recommendations for future research. PMID:26869409

  11. 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. PMID:24840232

  12. 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.

  13. Ultrasensitive surface-enhanced Raman scattering detection of trypsin based on anti-aggregation of 4-mercaptopyridine-functionalized silver nanoparticles: an optical sensing platform toward proteases

    NASA Astrophysics Data System (ADS)

    Chen, Lingxin; Fu, Xiuli; Li, Jinhua

    2013-06-01

    In this work, a simple and sensitive surface-enhanced Raman scattering (SERS) strategy was developed for recognition and detection of trypsin, by using anti-aggregation of 4-mercaptopyridine (4-MPY)-functionalized silver nanoparticles (AgNPs) based on the interaction between protamine and trypsin. The polycationic protamine not only served as a substrate for enzyme hydrolysis but also worked as a medium for SERS enhancement, which could bind negatively charged 4-MPY-functionalized AgNPs and induce their aggregation. The hydrolysis catalyzed with trypsin in sample solution decreased the concentration of free protamine, resulting in the dispersion of AgNPs and thus decreasing the Raman intensity of 4-MPY, by which the trypsin could be sensed optically. A detection level down to 0.1 ng mL-1 for trypsin was obtained. The induced accumulation of AgNPs modified with Raman reporter 4-MPY largely enhanced the SERS responses. A good linearity was found within the wide range over five orders of magnitude and reasonable relative standard deviations (between 2.4 and 11.6%) were attained. By using trypsin as a model, the new concept can provide an excellent platform for ultrasensitive SERS measurements of various proteases/enzymes which can lead to nanoparticles stability change through catalyzed hydrolysis toward substrate.In this work, a simple and sensitive surface-enhanced Raman scattering (SERS) strategy was developed for recognition and detection of trypsin, by using anti-aggregation of 4-mercaptopyridine (4-MPY)-functionalized silver nanoparticles (AgNPs) based on the interaction between protamine and trypsin. The polycationic protamine not only served as a substrate for enzyme hydrolysis but also worked as a medium for SERS enhancement, which could bind negatively charged 4-MPY-functionalized AgNPs and induce their aggregation. The hydrolysis catalyzed with trypsin in sample solution decreased the concentration of free protamine, resulting in the dispersion of AgNPs and

  14. 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

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

    PubMed

    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

  16. Utilization of Illinois coal gasification slags for production of ultra-lightweight aggregates. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Choudhry, V.; Zimmerle, T.

    1993-12-31

    This research was aimed at testing and developing the expansion potential of solid residues (slag) from gasification of Illinois coals to manufacture ultra-lightweight aggregates (ULWA). Conventional ULWAs are manufactured by pyroprocessing perlite or vermiculite ores and have unit weights in the 5--12 lb/ ft{sup 3} range. These materials sell for approximately $200/ton ($1.00/ft{sup 3}) and have numerous applications. The incentive for this effort was based on previous experimental results in which lightweight aggregates (LWA) with unit weights of 25--55 lb/ft{sup 3} were produced from Illinois slag using a direct-fired furnace. In this program, bench-scale expansion tests conducted with two Illinois coal slags resulted in product unit weights of 12 and 18.5 lb/ ft{sup 3}, thus confirming the feasibility of producing ULWA from Illinois slags. During initial pilot vertical shaft furnace test runs, two Illinois slags were expanded to generate products with unit weights of 12.5--26.5 and 20--52 lb/ ft{sup 3}. Further attempts to lower the product unit weights resulted in fusion of the slag. This problem could be overcome by methods including surface treatment of the slag, blending the slag with other materials, or utilization of indirect firing methods. To lower the product unit weights, an indirect-fired horizontal shaft furnace was used and products with unit weights of 12.4--52.0 lb/ft{sup 3} were generated, thus indicating that this method can be used to produce a wide range of expanded products. A large batch of expanded slag was produced using an 18-in. diameter x 12-ft long indirect-fired pilot furnace. A sample from this batch was characterized. Specimens of insulating concrete made from expanded slag had a unit weight 43.3 lb/ft{sup 3} and thermal conductivity of 1.34 Btu-in./h/ft{sup 2}/{degrees}F. This compares well with a value of 1. 2 Btu-in./h/ft{sup 2}/{degrees}F for insulating concrete of a similar weight made from perlite, as per ASTM C 332-82.

  17. Using Plant Functional Traits to Explain Diversity–Productivity Relationships

    PubMed Central

    Roscher, Christiane; Schumacher, Jens; Gubsch, Marlén; Lipowsky, Annett; Weigelt, Alexandra; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef

    2012-01-01

    Background The different hypotheses proposed to explain positive species richness–productivity relationships, i.e. selection effect and complementarity effect, imply that plant functional characteristics are at the core of a mechanistic understanding of biodiversity effects. Methodology/Principal Findings 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 predict biomass production and measures of biodiversity effects in experimental grasslands (Jena Experiment) with different species richness (2, 4, 8, 16 and 60) and different functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) four years after establishment. Functional trait composition had a larger predictive power for community biomass and measures of biodiversitity effects (40–82% of explained variation) than species richness per se (<1–13% of explained variation). CWM explained a larger amount of variation in community biomass (80%) and net biodiversity effects (70%) than FDQ (36 and 38% of explained variation respectively). FDQ explained similar proportions of variation in complementarity effects (24%, positive relationship) and selection effects (28%, negative relationship) as CWM (27% of explained variation for both complementarity and selection effects), but for all response variables the combination of CWM and FDQ led to significant model improvement compared to a separate consideration of different components of functional trait composition. Effects of FDQ were mainly attributable to diversity in nutrient acquisition and life-history strategies. The large spectrum of traits contributing to positive effects of CWM on biomass production and net biodiversity effects indicated that effects of dominant species were associated with different trait combinations. Conclusions/Significance Our results suggest that the

  18. 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.

  19. Production Functions Revisited in the Context of Educational Reform.

    ERIC Educational Resources Information Center

    MacPhail-Wilcox, Bettye; King, Richard A.

    1986-01-01

    Educational reform depends more on clearly defined missions and operational efficiency than on improved teacher quality. This article defines adequacy, equality, equity, and efficiency; examines numerous production function studies of teacher characteristics and policy and administrative structures; and summarizes seven policy implications.…

  20. 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...

  1. Preface: Biocatalysis and Biotechnology for Functional Foods and Industrial Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book was assembled with the intent of bringing together current advances and in-depth review of biocatalysis and biotechnology with emphasis on functional foods and industrial products. Biocatalysis and biotechnology defined in this book include enzyme catalysis, biotransformation, bioconversi...

  2. Production of modern functional materials based on renewable vegetable resources

    NASA Astrophysics Data System (ADS)

    Onishchenko, D. V.; Reva, V. P.

    2013-05-01

    An energy-saving technology for production of variously structured carbon modifications from a renewable vegetable raw material, i.e., the waste of agricultural crops and peat moss, has been developed. Promising functional materials — refractory compounds (tungsten and titanium carbides) and oil sorbents possessing a combination of high operating characteristics — have been formed on the basis of the synthesized carbon modifications.

  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. PMID:26048849

  4. 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

  5. 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

  6. Microfluidic production of multiple emulsions and functional microcapsules.

    PubMed

    Lee, Tae Yong; Choi, Tae Min; Shim, Tae Soup; Frijns, Raoul A M; Kim, Shin-Hyun

    2016-09-21

    Recent advances in microfluidics have enabled the controlled production of multiple-emulsion drops with onion-like topology. The multiple-emulsion drops possess an intrinsic core-shell geometry, which makes them useful as templates to create microcapsules with a solid membrane. High flexibility in the selection of materials and hierarchical order, achieved by microfluidic technologies, has provided versatility in the membrane properties and microcapsule functions. The microcapsules are now designed not just for storage and release of encapsulants but for sensing microenvironments, developing structural colours, and many other uses. This article reviews the current state of the art in the microfluidic-based production of multiple-emulsion drops and functional microcapsules. The three main sections of this paper discuss distinct microfluidic techniques developed for the generation of multiple emulsions, four representative methods used for solid membrane formation, and various applications of functional microcapsules. Finally, we outline the current limitations and future perspectives of microfluidics and microcapsules. PMID:27470590

  7. 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…

  8. Applications of aggregation theory to sustainability assessment

    DOE PAGESBeta

    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

  9. 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.

  10. 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.

  11. 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. PMID:24146783

  12. 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. PMID:23186359

  13. 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. PMID:26969252

  14. 3D-RISM-KH molecular theory of solvation and density functional theory investigation of the role of water in the aggregation of model asphaltenes.

    PubMed

    da Costa, L M; Hayaki, S; Stoyanov, S R; Gusarov, S; Tan, X; Gray, M R; Stryker, J M; Tykwinski, R; Carneiro, J Walkimar de M; Sato, H; Seidl, P R; Kovalenko, A

    2012-03-21

    We applied a multiscale modeling approach that involves the statistical-mechanical three-dimensional reference interaction site model with the Kovalenko-Hirata closure approximation (3D-RISM-KH molecular theory of solvation) as well as density functional theory (DFT) of electronic structure to study the role of water in aggregation of the asphaltene model compound 4,4'-bis(2-pyren-1-yl-ethyl)-2,2'-bipyridine (PBP) [X. Tan, H. Fenniri and M. R. Gray, Energy Fuels, 2008, 22, 715]. The solvation free energy and potential of mean force predicted by 3D-RISM-KH reveal favorable pathways for disaggregation of PBP dimers in pure versus water-saturated chloroform solvent. The water density distribution functions elucidate hydrogen bonding preferences and water bridge formation between PBP monomers. The ΔG(298) values of -5 to -7 kcal mol(-1) for transfer of water molecules in chloroform to a state interacting with PBP molecules are in agreement with experimental results. Geometry optimization and thermochemistry analysis of PBP dimers with and without water bridges using WB97Xd/6-31G(d,p) predict that both PBP dimerization and dimer stabilization by water bridges are spontaneous (ΔG(298) < 0). The (1)H NMR chemical shifts of PBP monomers and dimers predicted using the gauge-independent atomic orbital method and polarizable continuum model for solvation in chloroform are in an excellent agreement with the experimental results for dilute and concentrated PBP solutions in chloroform, respectively [X. Tan, H. Fenniri and M. R. Gray, Energy Fuels, 2009, 23, 3687]. The DFT calculations of PBP dimers with explicit water show that bridges containing 1-3 water molecules lead to stabilization of PBP dimers. Additional water molecules form hydrogen bonds with these bridges and de-shield the PBP protons, negating the effect of water on the (1)H(C3) NMR chemical shift of PBP, in agreement with experiment. The ΔG(298) results show that hydrogen bonding to water and water

  15. Current studies on physiological functions and biological production of lactosucrose.

    PubMed

    Mu, Wanmeng; Chen, Qiuming; Wang, Xiao; Zhang, Tao; Jiang, Bo

    2013-08-01

    Lactosucrose (O-β-D-galactopyranosyl-(1,4)-O-α-D-glucopyranosyl-(1,2)-β-D-fructofuranoside) is a trisaccharide formed from lactose and sucrose by enzymatic transglycosylation. This rare trisaccharide is a kind of indigestible carbohydrate, has good prebiotic effect, and promotes intestinal mineral absorption. It has been used as a functional ingredient in a range of food products which are approved as foods for specified health uses in Japan. Using lactose and sucrose as substrates, lactosucrose can be produced through transfructosylation by β-fructofuranosidase from Arthrobacter sp. K-1 or a range of levansucrases, or through transgalactosylation by β-galactosidase from Bacillus circulans. This article presented a review of recent studies on the physiological functions of lactosucrose and the biological production from lactose and sucrose by different enzymes. PMID:23828605

  16. 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

    2014-05-01

    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. PMID:24936458

  17. 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. PMID:21917640

  18. Demand for functional and nutritional enhancements in specialty milk products.

    PubMed

    Gulseven, Osman; Wohlgenant, Michael

    2014-10-01

    This article investigates the socio-demographic determinants affecting the demand for functional and nutritional enhancements in milk products based on a two-stage model. In order to derive the implicit market values of these enhancements, first we estimated the relationship between the prices of differentiated dairy products and the amount or respectively the presence of specific characteristics in these products. Next, using these implicit prices along with the information on households' demographic background, we analyzed the socio-demographic factors that affect consumer demand for specific functional and nutritional enhancements. The model is estimated using a combined panel data set based on AC Nielsen Retail Homescan Panel and the USDA Nutrient Database. Our results indicate that being lactose/cholesterol free (LFCF) and organic implies substantially higher price premiums, whereas soy has a negative price. Socio-demographic factors such as income, racial profile, presence of children; education level and age have significant effects on the demand for functional enhancements. Specialty milk consumption increases with age, education, and presence of kids, whereas it declines with income. The ratio of specialty milk consumption to total milk consumption is substantially higher among Hispanic, Asian and African-American households. PMID:24997409

  19. 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

  20. Resist charging effect correction function qualification for photomasks production

    NASA Astrophysics Data System (ADS)

    Sidorkin, Vadim; Finken, Michael; Wandel, Timo; Nakayamada, Noriaki; Cantrell, G. R.

    2014-10-01

    We quantitatively evaluate Nuflare's latest resist charging effect correction (CEC) model for advanced photomask production using e-beam lithography. Functionality of this CEC model includes the simulation of static and timedependent charging effects together with an improved calibration method. CEC model calibration is performed by polynomial fitting of image placement distortions induced by various beam scattering effects on a special test design with writing density variations. CEC model parameters can be fine tuned for different photomask blank materials facilitating resist charging compensation maps for different product layers. Application of this CEC model into production yields a significant reduction in photomask image placement (IP), as well as improving photomask overlay between critical neighbouring layers. The correlations between IP improvement facilitated by this CEC model and single mask parameters are presented and discussed. The layer design specifics, resist and blank materials, coupled with their required exposure parameters are observed to be the major influences on CEC model performance.

  1. 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

    2015-08-01

    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. PMID:25979518

  2. The Thioredoxin System Protects Ribosomes against Stress-induced Aggregation

    PubMed Central

    Rand, Jonathan D.; Grant, Chris M.

    2006-01-01

    We previously showed that thioredoxins are required for dithiothreitol (DTT) tolerance, suggesting they maintain redox homeostasis in response to both oxidative and reductive stress conditions. In this present study, we screened the complete set of viable deletion strains in Saccharomyces cerevisiae for sensitivity to DTT to identify cell functions involved in resistance to reductive stress. We identified 195 mutants, whose gene products are localized throughout the cell. DTT-sensitive mutants were distributed among most major biological processes, but they particularly affected gene expression, metabolism, and the secretory pathway. Strikingly, a mutant lacking TSA1, encoding a peroxiredoxin, showed a similar sensitivity to DTT as a thioredoxin mutant. Epistasis analysis indicated that thioredoxins function upstream of Tsa1 in providing tolerance to DTT. Our data show that the chaperone function of Tsa1, rather than its peroxidase function, is required for this activity. Cells lacking TSA1 were found to accumulate aggregated proteins, and this was exacerbated by exposure to DTT. Analysis of the protein aggregates revealed that they are predominantly composed of ribosomal proteins. Furthermore, aggregation was found to correlate with an inhibition of translation initiation. We propose that Tsa1 normally functions to chaperone misassembled ribosomal proteins, preventing the toxicity that arises from their aggregation. PMID:16251355

  3. Double Parton Fragmentation Function and its Evolution in Quarkonium Production

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo

    2014-01-01

    We summarize the results of a recent study on a new perturbative QCD factorization formalism for the production of heavy quarkonia of large transverse momentum pT at collider energies. Such a new factorization formalism includes both the leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the mQ2/p_T^2 expansion for heavy quark mass mQ. For the NLP contribution, the so-called double parton fragmentation functions are involved, whose evolution equations have been derived. We estimate fragmentation functions in the non-relativistic QCD formalism, and found that their contribution reproduce the bulk of the large enhancement found in explicit NLO calculations in the color singlet model. Heavy quarkonia produced from NLP channels prefer longitudinal polarization, in contrast to the single parton fragmentation function. This might shed some light on the heavy quarkonium polarization puzzle.

  4. 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.

  5. Thermostable keratinase from Bacillus pumilus KS12: production, chitin crosslinking and degradation of Sup35NM aggregates.

    PubMed

    Rajput, Rinky; Gupta, Rani

    2013-04-01

    Production of thermostable keratinase from Bacillus pumilus KS12 was enhanced up to seven fold by statistical methods. The enzyme was partially purified by ultrafiltration followed by thermal precipitation with purity of 3.2-fold and recovery of 89%. Keratinase was immobilized using covalent method by crosslinking 2 mg protein (688 U/mg) onto 1g chitin activated with 2.5% (v/v) glutaraldehyde for 60 min. Its comparative biochemical studies with that of free keratinase revealed the shift in optimum pH with increased stability towards pH from 9.0 to 10.0 and temperature. Also, it showed statistically significant improved hydrolysis of a number of soluble and insoluble substrates in comparison to free keratinase. Owing to improved catalytic efficiency of immobilized keratinase, its potential for degradation of Sup35NM was evaluated, where 100 μg of enzyme could degrade 60 μg Sup35NM after 60 min at pH 7.0 and 37°C. PMID:23425582

  6. Characterization of a Multiresistant Mosaic Plasmid from a Fish Farm Sediment Exiguobacterium sp. Isolate Reveals Aggregation of Functional Clinic-Associated Antibiotic Resistance Genes

    PubMed Central

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

    2014-01-01

    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. PMID:24362420

  7. Aggregation of Ribosomal Protein S6 at Nucleolus Is Cell Cycle-Controlled and Its Function in Pre-rRNA Processing Is Phosphorylation Dependent.

    PubMed

    Zhang, Duo; Chen, Hui-Peng; Duan, Hai-Feng; Gao, Li-Hua; Shao, Yong; Chen, Ke-Yan; Wang, You-Liang; Lan, Feng-Hua; Hu, Xian-Wen

    2016-07-01

    Ribosomal protein S6 (rpS6) has long been regarded as one of the primary r-proteins that functions in the early stage of 40S subunit assembly, but its actual role is still obscure. The correct forming of 18S rRNA is a key step in the nuclear synthesis of 40S subunit. In this study, we demonstrate that rpS6 participates in the processing of 30S pre-rRNA to 18S rRNA only when its C-terminal five serines are phosphorylated, however, the process of entering the nucleus and then targeting the nucleolus does not dependent its phosphorylation. Remarkably, we also find that the aggregation of rpS6 at the nucleolus correlates to the phasing of cell cycle, beginning to concentrate in the nucleolus at later S phase and disaggregate at M phase. J. Cell. Biochem. 117: 1649-1657, 2016. © 2015 Wiley Periodicals, Inc. PMID:26639987

  8. 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

  9. 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. PMID:18942836

  10. Kinetic model for erythrocyte aggregation.

    PubMed

    Bertoluzzo, S M; Bollini, A; Rasia, M; Raynal, A

    1999-01-01

    It is well known that light transmission through blood is the most widely utilized method for the study of erythrocyte aggregation. The curves obtained had been considered empirically as exponential functions. In consequence, the process becomes characterized by an only parameter that varies with all the process factors without discrimination. In the present paper a mathematical model for RBC aggregation process is deduced in accordance with von Smoluchowski's theory about the kinetics of colloidal particles agglomeration. The equation fitted the experimental pattern of the RBC suspension optical transmittance closely and contained two parameters that estimate the most important characteristics of the aggregation process separately, i.e., (1) average size of rouleaux at equilibrium and (2) aggregation rate. The evaluation of the method was assessed by some factors affecting erythrocyte aggregation, such as temperature, plasma dilutions, Dextran 500, Dextran 70 and PVP 360, at different media concentrations, cellular membrane alteration by the alkylating agent TCEA, and decrease of medium osmolarity. Results were interpreted considering the process characteristics estimated by the parameters, and there were also compared with similar studies carried out by other authors with other methods. This analysis allowed us to conclude that the equation proposed is reliable and useful to study erythrocyte aggregation. PMID:10660481

  11. Fish protein hydrolysates: production, biochemical, and functional properties.

    PubMed

    Kristinsson, H G; Rasco, B A

    2000-01-01

    Considerable amounts of fish processing byproducts are discarded each year. By developing enzyme technologies for protein recovery and modification, production of a broad spectrum of food ingredients and industrial products may be possible. Hydrolyzed vegetable and milk proteins are widely used food ingredients. There are few hydrolyzed fish protein foods with the exception of East Asian condiments and sauces. This review describes various manufacturing techniques for fish protein hydrolysates using acid, base, endogenous enzymes, and added bacterial or digestive proteases. The chemical and biochemical characteristics of hydrolyzed fish proteins are discussed. In addition, functional properties of fish protein hydrolysates are described, including solubility, water-holding capacity, emulsification, and foam-forming ability. Possible applications of fish protein hydrolysates in food systems are provided, and comparison with other food protein hydrolysates where pertinent. PMID:10674201

  12. 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.

  13. Linking geophysics and soil function modelling - biomass production

    NASA Astrophysics Data System (ADS)

    Krüger, J.; Franko, U.; Werban, U.; Fank, J.

    2012-04-01

    The iSOIL project aims at reliable mapping of soil properties and soil functions with various methods including geophysical, spectroscopic and monitoring techniques. The general procedure contains three steps (i) geophysical monitoring, (ii) generation of soil property maps and (iii) process modelling. The objective of this work is to demonstrate the mentioned procedure with a focus on process modelling. It deals with the dynamics of soil water and the direct influence on crop biomass production. The new module PLUS extends CANDY to simulate crop biomass production based on environmental influences. A soil function modelling with an adapted model parameterisation based on data of ground penetration radar (GPR) and conductivity (EM38) was realized. This study shows an approach to handle heterogeneity of soil properties with geophysical data used for biomass production modelling. The Austrian field site Wagna is characterised by highly heterogenic soil with fluvioglacial gravel sediments. The variation of thickness of topsoil above a sandy subsoil with gravels strongly influences the soil water balance. EM38, mounted on a mobile platform, enables to rapidly scan large areas whereas GPR requires a greater logistical effort. However, GPR can detect exact soil horizon depth between topsoil and subsoil, the combination of both results in a detailed large scale soil map. The combined plot-specific GPR and field site EM38 measurements extends the soil input data and improves the model performance of CANDY PLUS for plant biomass production (Krüger et al. 2011). The example demonstrates how geophysics provides a surplus of data for agroecosystem modelling which identifies and contributes alternative options for agricultural management decisions. iSOIL - "Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping" is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission

  14. Universal microscopic correlation functions for products of truncated unitary matrices

    NASA Astrophysics Data System (ADS)

    Akemann, Gernot; Burda, Zdzislaw; Kieburg, Mario; Nagao, Taro

    2014-06-01

    We investigate the spectral properties of the product of M complex non-Hermitian random matrices that are obtained by removing L rows and columns of larger unitary random matrices uniformly distributed on the group U(N + L). Such matrices are called truncated unitary matrices or random contractions. We first derive the joint probability distribution for the complex eigenvalues of the product matrix for fixed N, L, and M, given by a standard determinantal point process in the complex plane. The weight however is non-standard and can be expressed in terms of the Meijer G-function. The explicit knowledge of all eigenvalue correlation functions and the corresponding kernel allows us to take various large N (and L) limits at fixed M. At strong non-unitarity, with L/N finite, the eigenvalues condense on a domain inside the unit circle. At the edge and in the bulk we find the same universal microscopic kernel as for a single complex non-Hermitian matrix from the Ginibre ensemble. At the origin we find the same new universality classes labeled by M as for the product of M matrices from the Ginibre ensemble. Keeping a fixed size of truncation, L, when N goes to infinity leads to weak non-unitarity, with most eigenvalues on the unit circle as for unitary matrices. Here we find a new microscopic edge kernel that generalizes the known results for M = 1. We briefly comment on the case when each product matrix results from a truncation of different size Lj.

  15. 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.

  16. Functional cereals for production in new and variable climates.

    PubMed

    Henry, Robert J; Rangan, Parimalan; Furtado, Agnelo

    2016-04-01

    Adaptation of cereal crops to variable or changing climates requires that essential quality attributes are maintained to deliver food that will be acceptable to human consumers. Advances in cereal genomics are delivering insights into the molecular basis of nutritional and functional quality traits in cereals and defining new genetic resources. Understanding the influence of the environment on expression of these traits will support the retention of these essential functional properties during climate adaptation. New cereals for use as whole grain or ground to flour for other food products may be based upon the traditional species such as rice and wheat currently used in these food applications but may also include new options exploiting genomics tools to allow accelerated domestication of new species. PMID:26828379

  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)

    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.

  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)

    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.

  19. 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. PMID:24615918

  20. Modulation of platelet aggregation by areca nut and betel leaf ingredients: roles of reactive oxygen species and cyclooxygenase.

    PubMed

    Jeng, Jiiang-Huei; Chen, Shiao-Yun; Liao, Chang-Hui; Tung, Yuan-Yii; Lin, Bor-Ru; Hahn, Liang-Jiunn; Chang, Mei-Chi

    2002-05-01

    There are 2 to 6 billion betel quid (BQ) chewers in the world. Areca nut (AN), a BQ component, modulates arachidonic acid (AA) metabolism, which is crucial for platelet function. AN extract (1 and 2 mg/ml) stimulated rabbit platelet aggregation, with induction of thromboxane B2 (TXB2) production. Contrastingly, Piper betle leaf (PBL) extract inhibited AA-, collagen-, and U46619-induced platelet aggregation, and TXB2 and prostaglandin-D2 (PGD2) production. PBL extract also inhibited platelet TXB2 and PGD2 production triggered by thrombin, platelet activating factor (PAF), and adenosine diphosphate (ADP), whereas little effect on platelet aggregation was noted. Moreover, PBL is a scavenger of O2(*-) and *OH, and inhibits xanthine oxidase activity and the (*)OH-induced PUC18 DNA breaks. Deferoxamine, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) and neomycin prevented AN-induced platelet aggregation and TXB2 production. Indomethacin, genistein, and PBL extract inhibited only TXB2 production, but not platelet aggregation. Catalase, superoxide dismutase, and dimethylthiourea (DMT) showed little effect on AN-induced platelet aggregation, whereas catalase and DMT inhibited the AN-induced TXB2 production. These results suggest that AN-induced platelet aggregation is associated with iron-mediated reactive oxygen species production, calcium mobilization, phospholipase C activation, and TXB2 production. PBL inhibited platelet aggregation via both its antioxidative effects and effects on TXB2 and PGD2 production. Effects of AN and PBL on platelet aggregation and AA metabolism is crucial for platelet activation in the oral mucosa and cardiovascular system in BQ chewers. PMID:11978487

  1. 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...

  2. The Myxococcus xanthus dsg gene product performs functions of translation initiation factor IF3 in vivo.

    PubMed Central

    Kalman, L V; Cheng, Y L; Kaiser, D

    1994-01-01

    The amino acid sequence of the Dsg protein is 50% identical to that of translation initiation factor IF3 of Escherichia coli, the product of its infC gene. Anti-E. coli IF3 antibodies cross-react with the Dsg protein. Tn5 insertion mutations in dsg are lethal. When ample nutrients are available, however, certain dsg point mutant strains grow at the same rate as wild-type cells. Under the starvation conditions that induce fruiting body development, these dsg mutants begin to aggregate but fail to develop further. The level of Dsg antigen, as a fraction of total cell protein, does not change detectably during growth and development, as expected for a factor essential for protein synthesis. The amount of IF3 protein in E. coli is known to be autoregulated at the translational level. This autoregulation is lost in an E. coli infC362 missense mutant. The dsg+ gene from Myxococcus xanthus restores normal autoregulation to the infC362 mutant strain. Dsg is distinguished from IF3 of E. coli, other enteric bacteria, and Bacillus stearothermophilus by having a C-terminal tail of 66 amino acids. Partial and complete deletion of this tail showed that it is needed for certain vegetative and developmental functions but not for viability. Images PMID:8113185

  3. 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. PMID:24932768

  4. Probiotics and its functionally valuable products-a review.

    PubMed

    Kanmani, Paulraj; Satish Kumar, R; Yuvaraj, N; Paari, K A; Pattukumar, V; Arul, Venkatesan

    2013-01-01

    During the past two decades probiotic bacteria have been increasingly proposed as health promoting bacteria in variety of food system, because of its safety, functional, and technological characteristics. Commonly, Lactobacillus spp., Bifidobacterium spp., Saccharomyces boulardii, and some other microorganisms have been considered as probiotic strains. Possibly these bacterial strains exerted several beneficial effects into gastrointestinal tract of host while administered with variety of food system. Lactic acid bacteria (LAB) usually produce antimicrobial substances like bacteriocin which have broad spectrum of antagonist effect against closely related Gram positive and Gram negative pathogens. LAB strains often produce polymeric substances such as exopolysaccharides (EPS) which increase the colonization of probiotic bacteria by cell-cell interactions in gastrointestinal tract. LAB also produces biosurfactant which showed that the wide range of antimicrobial activity against bacterial pathogen as well as its antiadhesive properties reduces the adhesion of pathogens into gastric wall membrane. Furthermore, LAB strains have also been reported for production of antioxidants which are ability to scavenge the free radicals such as superoxide anions and hydroxyl radicals. For this sense, this review article is mainly focused on the ecology, biosynthesis, genetics, target sites, and applications of bacteriocins and EPS from LAB strains. Moreover, this review discusses about the production and functions of nutritive essential element folate and iron chelating agent such as siderophores from LAB. PMID:23627505

  5. 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.

  6. 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.

  7. Platelet aggregation test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003669.htm Platelet aggregation test To use the sharing features on this page, please enable JavaScript. The platelet aggregation blood test checks how well platelets , a ...

  8. 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.

  9. Making Graphene Resist Aggregation

    NASA Astrophysics Data System (ADS)

    Luo, Jiayan

    Graphene-based sheets have stimulated great interest in many scientific disciplines and shown promise for wide potential applications. Among various ways of creating single atomic layer carbon sheets, a promising route for bulk production is to first chemically exfoliate graphite powders to graphene oxide (GO) sheets, followed by reduction to form chemically modified graphene (CMG). Due to the strong van der Waals attraction between graphene sheets, CMG tends to aggregate. The restacking of sheets is largely uncontrollable and irreversible, thus it reduces their processability and compromises properties such as accessible surface area. Strategies based on colloidal chemistry have been applied to keep CMG dispersed in solvents by introducing electrostatic repulsion to overcome the van der Waals attraction or adding spacers to increase the inter-sheet spacing. In this dissertation, two very different ideas that can prevent CMG aggregation without extensively modifying the material or introducing foreign spacer materials are introduced. The van der Waals potential decreases with reduced overlapping area between sheets. For CMG, reducing the lateral dimension from micrometer to nanometer scale should greatly enhance their colloidal stability with additional advantages of increased charge density and decreased probability to interact. The enhanced colloidal stability of GO and CMG nanocolloids makes them especially promising for spectroscopy based bio-sensing applications. For potential applications in a compact bulk solid form, the sheets were converted into paper-ball like structure using capillary compression in evaporating aerosol droplets. The crumpled graphene balls are stabilized by locally folded pi-pi stacked ridges, and do not unfold or collapse during common processing steps. They can tightly pack without greatly reducing the surface area. This form of graphene leads to scalable performance in energy storage. For example, planer sheets tend to aggregate and

  10. Effect of functional group richness and species richness in manipulated productivity diversity studies: a glasshouse pot experiment

    NASA Astrophysics Data System (ADS)

    Lanta, Vojtěch; Lepš, Jan

    2006-01-01

    effectively decrease the nutrient levels. As a consequence, mixtures of high diversity were always more productive under high nutrients. The difference in species proportions between high and low nutrients, characterized by chord distance, increased with species richness. The relative change in productivity decreased with the number of functional groups. This suggests that species richness might lead to stabilization of aggregate characteristics (like total productivity) under changing environmental conditions by changing the proportions of individual species.

  11. Work Function Modification in P3HT H/J Aggregate Nanostructures Revealed by Kelvin Probe Force Microscopy and Photoluminescence Imaging.

    PubMed

    Baghgar, Mina; Barnes, Michael D

    2015-07-28

    We show that surface electronic properties of poly-3-hexylthiophene (P3HT) crystalline nanofibers as probed by Kelvin probe force microscopy (KPFM) depends sensitively on the degree of polymer packing order and dominant coupling type (e.g., H- or J-aggregate) as signaled by absorption or photoluminescence spectroscopy. Nominal HOMO energies between high molecular weight (J-aggregate) nanofibers and low-molecular weight (H-aggregate) nanofibers differ by ≈160 meV. This is consistent with shifts expected from H-type charge-transfer (CT) interactions that lower HOMO energies according to registration between thiophene moieties on adjacent polymer chains. These results show how KPFM combined with wavelength-resolved photoluminescence imaging can be used to extract information on "dark" (CT) interactions in polymer assemblies. PMID:26095304

  12. 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.

  13. Natural Product Discovery through Improved Functional Metagenomics in Streptomyces.

    PubMed

    Iqbal, Hala A; Low-Beinart, Lila; Obiajulu, Joseph U; Brady, Sean F

    2016-08-01

    Because the majority of environmental bacteria are not easily culturable, access to many bacterially encoded secondary metabolites will be dependent on the development of improved functional metagenomic screening methods. In this study, we examined a collection of diverse Streptomyces species for the best innate ability to heterologously express biosynthetic gene clusters. We then optimized methods for constructing high quality metagenomic cosmid libraries in the best Streptomyces host. An initial screen of a 1.5 million-membered metagenomic library constructed in Streptomyces albus, the species that exhibited the highest propensity for heterologous expression of gene clusters, led to the identification of the novel natural product metatricycloene (1). Metatricycloene is a tricyclic polyene encoded by a reductive, iterative polyketide-like gene cluster. Related gene clusters found in sequenced genomes appear to encode a largely unexplored collection of structurally diverse, polyene-based metabolites. PMID:27447056

  14. 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

  15. An anticancer drug suppresses the primary nucleation reaction that initiates the production of the toxic Aβ42 aggregates linked with Alzheimer’s disease

    PubMed Central

    Habchi, Johnny; Arosio, Paolo; Perni, Michele; Costa, Ana Rita; Yagi-Utsumi, Maho; Joshi, Priyanka; Chia, Sean; Cohen, Samuel I. A.; Müller, Martin B. D.; Linse, Sara; Nollen, Ellen A. A.; Dobson, Christopher M.; Knowles, Tuomas P. J.; Vendruscolo, Michele

    2016-01-01

    The conversion of the β-amyloid (Aβ) peptide into pathogenic aggregates is linked to the onset and progression of Alzheimer’s disease. Although this observation has prompted an extensive search for therapeutic agents to modulate the concentration of Aβ or inhibit its aggregation, all clinical trials with these objectives have so far failed, at least in part because of a lack of understanding of the molecular mechanisms underlying the process of aggregation and its inhibition. To address this problem, we describe a chemical kinetics approach for rational drug discovery, in which the effects of small molecules on the rates of specific microscopic steps in the self-assembly of Aβ42, the most aggregation-prone variant of Aβ, are analyzed quantitatively. By applying this approach, we report that bexarotene, an anticancer drug approved by the U.S. Food and Drug Administration, selectively targets the primary nucleation step in Aβ42 aggregation, delays the formation of toxic species in neuroblastoma cells, and completely suppresses Aβ42 deposition and its consequences in a Caenorhabditis elegans model of Aβ42-mediated toxicity. These results suggest that the prevention of the primary nucleation of Aβ42 by compounds such as bexarotene could potentially reduce the risk of onset of Alzheimer’s disease and, more generally, that our strategy provides a general framework for the rational identification of a range of candidate drugs directed against neurodegenerative disorders. PMID:26933687

  16. An anticancer drug suppresses the primary nucleation reaction that initiates the production of the toxic Aβ42 aggregates linked with Alzheimer's disease.

    PubMed

    Habchi, Johnny; Arosio, Paolo; Perni, Michele; Costa, Ana Rita; Yagi-Utsumi, Maho; Joshi, Priyanka; Chia, Sean; Cohen, Samuel I A; Müller, Martin B D; Linse, Sara; Nollen, Ellen A A; Dobson, Christopher M; Knowles, Tuomas P J; Vendruscolo, Michele

    2016-02-01

    The conversion of the β-amyloid (Aβ) peptide into pathogenic aggregates is linked to the onset and progression of Alzheimer's disease. Although this observation has prompted an extensive search for therapeutic agents to modulate the concentration of Aβ or inhibit its aggregation, all clinical trials with these objectives have so far failed, at least in part because of a lack of understanding of the molecular mechanisms underlying the process of aggregation and its inhibition. To address this problem, we describe a chemical kinetics approach for rational drug discovery, in which the effects of small molecules on the rates of specific microscopic steps in the self-assembly of Aβ42, the most aggregation-prone variant of Aβ, are analyzed quantitatively. By applying this approach, we report that bexarotene, an anticancer drug approved by the U.S. Food and Drug Administration, selectively targets the primary nucleation step in Aβ42 aggregation, delays the formation of toxic species in neuroblastoma cells, and completely suppresses Aβ42 deposition and its consequences in a Caenorhabditis elegans model of Aβ42-mediated toxicity. These results suggest that the prevention of the primary nucleation of Aβ42 by compounds such as bexarotene could potentially reduce the risk of onset of Alzheimer's disease and, more generally, that our strategy provides a general framework for the rational identification of a range of candidate drugs directed against neurodegenerative disorders. PMID:26933687

  17. Groundwater productivity potential mapping using evidential belief function.

    PubMed

    Park, Inhye; Kim, Yongsung; Lee, Saro

    2014-09-01

    The evidential belief function (EBF) model was applied and validated for analysis of groundwater-productivity potential (GPP) in Boryeong and Pohang cities, agriculture region in Korea using geographic information systems (GIS). Data about related factors, including topography, lineament, geology, forest, soil, and groundwater data were collected and input into a spatial database. Additionally, in the Boryeong area, specific capacity (SPC) data not lower than 4.55 m3 /d/m were collected, corresponding to 300 m3 /d yield from 72 well locations. In the Pohang area, SPC data of ≥ 6.25 m3 /d/m were collected, corresponding to a yield of 500 m3 /d from 44 well locations. By using the constructed spatial database, 19 factors related to groundwater productivity were extracted. The relationships between the well locations and the factors were identified and quantified by using the EBF model. Four relationships were calculated: belief (Bel), disbelief (Dis), uncertainty (Unc), and plausibility (Pls). The relationships were used as factor ratings in the overlay analysis to create GPP indices and maps. The resulting GPP maps showed 83.41% and 77.53% accuracy in Boryeong and Pohang areas, respectively. The EBF model was found to be more effective in terms of prediction accuracy. PMID:24841077

  18. 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.

  19. 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. PMID:26930796

  20. 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.

  1. Force aggregation using genetic algortihms

    NASA Astrophysics Data System (ADS)

    Shea, Peter J.; Peterson, John; Alexander, Kathleen; Azevedo, Alcino

    2004-01-01

    A surveillance system needs to accurately locate and identify not only single targets, but also groups of targets engaged in a common activity. Most existing tracking systems are capable of tracking individual targets quite accurately; however, they fail to use information related to group behavior in order to improve these estimates. Furthermore, in wide area surveillance situations a military operator is required to sort through hundreds to thousands of individual targets in order to develop an understanding of the situation. Having the ability to collapse the behavior of individual targets into a common, coordinated motion can greatly enhance the productively and situational awareness of the operator. Our long-term approach to solving this problem is to develop an understanding of how to define a group and then to understand the inter-relationships between the various characteristics that describe a group. Then using this information, we will be able to partition the set of target into groups that can be aggregated over the entire military force hierarchy. This goal of this paper is to describe an approach that is based upon genetic algorithms for solving the military force hierarchy problem. This paper will describe the underlying genetic algorithm, scoring function, and some initial results.

  2. Force aggregation using genetic algortihms

    NASA Astrophysics Data System (ADS)

    Shea, Peter J.; Peterson, John; Alexander, Kathleen; Azevedo, Alcino

    2003-12-01

    A surveillance system needs to accurately locate and identify not only single targets, but also groups of targets engaged in a common activity. Most existing tracking systems are capable of tracking individual targets quite accurately; however, they fail to use information related to group behavior in order to improve these estimates. Furthermore, in wide area surveillance situations a military operator is required to sort through hundreds to thousands of individual targets in order to develop an understanding of the situation. Having the ability to collapse the behavior of individual targets into a common, coordinated motion can greatly enhance the productively and situational awareness of the operator. Our long-term approach to solving this problem is to develop an understanding of how to define a group and then to understand the inter-relationships between the various characteristics that describe a group. Then using this information, we will be able to partition the set of target into groups that can be aggregated over the entire military force hierarchy. This goal of this paper is to describe an approach that is based upon genetic algorithms for solving the military force hierarchy problem. This paper will describe the underlying genetic algorithm, scoring function, and some initial results.

  3. Immunogenicity of therapeutic proteins: Influence of aggregation

    PubMed Central

    Derrick, Jeremy P.; Dearman, Rebecca J.; Kimber, Ian

    2014-01-01

    The elicitation of anti-drug antibodies (ADA) against biotherapeutics can have detrimental effects on drug safety, efficacy, and pharmacokinetics. The immunogenicity of biotherapeutics is, therefore, an important issue. There is evidence that protein aggregation can result in enhanced immunogenicity; however, the precise immunological and biochemical mechanisms responsible are poorly defined. In the context of biotherapeutic drug development and safety assessment, understanding the mechanisms underlying aggregate immunogenicity is of considerable interest. This review provides an overview of the phenomenon of protein aggregation, the production of unwanted aggregates during bioprocessing, and how the immune response to aggregated protein differs from that provoked by non-aggregated protein. Of particular interest is the nature of the interaction of aggregates with the immune system and how subsequent ADA responses are induced. Pathways considered here include ‘classical’ activation of the immune system involving antigen presenting cells and, alternatively, the breakdown of B-cell tolerance. Additionally, methods available to screen for aggregation and immunogenicity will be described. With an increased understanding of aggregation-enhanced immune responses, it may be possible to develop improved manufacturing and screening processes to avoid, or at least reduce, the problems associated with ADA. PMID:23919460

  4. 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.

  5. 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. PMID:20800847

  6. The functional role of some tomato products on lipid profile and liver function in adult rats.

    PubMed

    Ibrahim, Hoda Salama; Ahmed, Lamiaa Ali; El-din, Maha Mohamed Essam

    2008-09-01

    This study was carried out to investigate the functional role of lycopene obtained from powder prepared from fresh tomato, tomato paste, and ketchup that contained equal amounts of lycopene based on levels of intake on body weight gain (BWG), feed intake, feed efficiency ratio (FER), lipid profiles, atherogenic index, and liver enzymes of hyperlipidemic rats. Forty-eight male albino rats were divided into two main groups: the first group (n = 6 rats) was kept on the basal diet as a normal control, while the second group (n = 42 rats) was fed a hyperlipidemic diet for 5 weeks to induce hyperlipidemia. The latter group was divided into seven subgroups: the first subgroup was the positive control group, while the others were supplemented with one of the tomato products at one of two levels (10 or 20 mg of lycopene/kg of diet). BWG, feed intake, and FER were calculated, and blood samples were collected to determine total lipids, total cholesterol, triglycerides, lipoprotein fractions, atherogenic index, and liver function in sera. Relative organ weights were also calculated. Results revealed that administration of various tomato products produced a significant reduction in feed intake except for the hyperlipidemic group that supplemented with the lower lycopene level from tomato paste. In addition, BWG and FER were not influenced by addition of tomato products at any level of intake. Hyperlipidemic rats supplemented with tomato powder, tomato paste, or ketchup showed significant improvement in almost all the parameters studied compared to the positive control group. Results showed that the higher lycopene level from tomato paste produced significant improvement in all lipid parameters, followed by 10 mg of lycopene/kg from tomato paste, which caused significant elevation in high-density lipoprotein cholesterol comparable to that of the negative control group. The lowest atherogenic index was achieved by addition of the lower lycopene level from tomato paste followed by

  7. Dithiafulvalene functionalized diketopyrrolopyrrole based sensitizers for efficient hydrogen production.

    PubMed

    Narayanaswamy, K; Tiwari, Amritanjali; Mondal, Indranil; Pal, Ujjwal; Niveditha, S; Bhanuprakash, K; Singh, Surya Prakash

    2015-05-28

    We have designed and synthesized two new diketopyrrolopyrrole (DPP) based organic sensitizers (DPPCA and DPPCN) with the dithiafulvalene (DTF) unit as donor and cyanoacrylic acid/malononitrile as acceptor moieties. These dyes showed excellent efficiency of photocatalytic hydrogen production over a Pt-TiO2 composite via solar-induced water splitting. The sensitizers showed broad absorptions over the wide visible regime (500-800 nm). In DPPCN, the malononitrile moiety led to strong intra-molecular charge transfer, as evidenced by red shifted (∼24 nm) absorption maxima with highly enhanced molar absorptivity (108 190 M(-1) cm(-1)). The electrochemical characterization of as-prepared sensitizers confirmed the feasible electron injection from the dye to the TiO2 conduction band (CB) which has been further validated by theoretical studies. In this study, the rate of the photocatalytic activity was found to be dependent on the acceptor part of the dye molecule as DPPCN sensitized Pt-TiO2 (DNPT) exhibited remarkable (1208 μmol) hydrogen evolution yield in comparison to DPPCA sensitized Pt-TiO2 (DAPT) (840 μmol). The rigid DPP core made the sensitizers significantly photo-stable as affirmed by their high hydrogen production efficiency over 80 h of prolonged irradiation. As predicted from density functional theory (DFT) calculations, ground state geometry of the dyes was almost planar, facilitating continuous conjugation throughout the molecule. Time-dependent DFT (TD-DFT) calculations were also carried out to make clear the understanding of charge transfer transition of the dye molecules. PMID:25942447

  8. 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. PMID:25048774

  9. Ionic Aggregation and Microphase Separation in Sulfonated Polyester Multiblock Copolymers and Ionomers

    NASA Astrophysics Data System (ADS)

    O'Reilly, Michael; Tudryn, Gregory; Colby, Ralph; Winey, Karen

    2011-03-01

    Polyethylene oxide (PEO) has been copolymerized with polytetramethylene oxide (PTMO) using a sulfonated phthalate ionic linker between blocks. The product is a linear multiblock copolymer, which is neutralized with lithium and sodium. We used X-ray scattering to investigate the morphology from 25°C to 200°C. The results show that this copolymer exhibits three distinct morphology characteristics. First, microphase separation exists between the PEO and PTMO phases. Second, ionic aggregates occur in the PEO microdomains. Finally, the appearance of better defined ionic aggregates occurs in the PTMO microdomains. Ion aggregation and microphase separation are studied as functions of temperature and copolymer molar composition. DRS analysis confirms that ionic aggregation is independent of copolymer composition.

  10. Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: a review.

    PubMed

    Sheng, Guo-Ping; Yu, Han-Qing; Li, Xiao-Yan

    2010-01-01

    A review concerning the definition, extraction, characterization, production and functions of extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment reactors is given in this paper. EPS are a complex high-molecular-weight mixture of polymers excreted by microorganisms, produced from cell lysis and adsorbed organic matter from wastewater. They are a major component in microbial aggregates for keeping them together in a three-dimensional matrix. Their characteristics (e.g., adsorption abilities, biodegradability and hydrophilicity/hydrophobicity) and the contents of the main components (e.g., carbohydrates, proteins, humic substances and nucleic acids) in EPS are found to crucially affect the properties of microbial aggregates, such as mass transfer, surface characteristics, adsorption ability, stability, the formation of microbial aggregates etc. However, as EPS are very complex, the knowledge regarding EPS is far from complete and much work is still required to fully understand their precise roles in the biological treatment process. PMID:20705128

  11. Design of a dual-function peptide probe as a binder of angiotensin II and an inducer of silver nanoparticle aggregation for use in label-free colorimetric assays.

    PubMed

    Okochi, Mina; Kuboyama, Masashi; Tanaka, Masayoshi; Honda, Hiroyuki

    2015-09-01

    Label-free colorimetric assays using metallic nanoparticles have received much recent attention, for their application in simple and sensitive methods for detection of biomolecules. Short peptide probes that can bind to analyte biomolecules are attractive ligands in molecular nanotechnology; however, identification of biological recognition motifs is usually based on trial-and-error experiments. Herein, a peptide probe was screened for colorimetric detection of angiotensin II (Ang II) using a mechanism for non-crosslinking aggregation of silver nanoparticles (AgNPs). The dual-function peptides, which bind to the analyte and induce AgNP aggregation, were identified using a two-step strategy: (1) screening of an Ang II-binding peptide from an Ang II receptor sequence library, using SPOT technology, which enable peptides synthesis on cellulose membranes via an Fmoc method and (2) selection of peptide probes that effectively induce aggregation of AgNPs using a photolinker modified peptide array. Using the identified peptide probe, KGKNKRRR, aggregation of AgNPs was detected by observation of a pink color in the absence of Ang II, whereas AgNPs remained dispersed in the presence of Ang II (yellow). The color changes were not observed in the presence of other hormone molecules. Ang II could be detected within 15 min, with a detection limit of 10 µM, by measuring the ratio of absorbance at 400 nm and 568 nm; the signal could also be observed with the naked eye. These data suggest that the peptide identified here could be used as a probe for simple and rapid colorimetric detection of Ang II. This strategy for the identification of functional peptides shows promise for the development of colorimetric detection of various diagnostically important biomolecules. PMID:26003717

  12. 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

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

    PubMed

    Römling, Ute; Galperin, Michael Y

    2015-09-01

    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 (i) the expression of the biosynthesis apparatus, (ii) the export of the nascent β-D-glucan polymer to the cell surface, and (iii) the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of resulting biofilms, which is particularly important for the interactions of bacteria with higher organisms - leading to rhizosphere colonization and modulating the virulence of cellulose-producing bacterial pathogens inside and outside of host cells. We review the organization of four principal types of cellulose synthase operon found in various bacterial genomes, identify additional bcs genes that encode 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 and in the choice between acute infection and persistence in the host. PMID:26077867

  14. 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.

  15. Poly (I:C) downregulates platelet production and function through type I interferon.

    PubMed

    Rivadeneyra, Leonardo; Pozner, Roberto Gabriel; Meiss, Roberto; Fondevila, Carlos; Gómez, Ricardo Martin; Schattner, Mirta

    2015-11-01

    Thrombocytopenia is a frequent complication of viral infections; the underlying mechanisms appear to depend on the identity of the virus involved. Previous research, including reports from our group, indicates that as well as having antiviral activity type I interferons (IFN I) selectively downregulate platelet production. In this study we extended understanding of the role of endogenous IFN I in megakaryo/thrombopoiesis by evaluating platelet and megakaryocyte physiology in mice treated with polyinosinic:polycytidylic acid [poly (I:C)], a synthetic analogue of double-stranded RNA, Toll-like receptor-3 ligand and strong IFNβ inducer. Mice-treated with poly (I:C) showed thrombocytopaenia, an increase in mean platelet volume and abnormal haemostatic and inflammatory platelet-mediated functionality, indicated by decreased fibrinogen binding and platelet adhesion, prolonged tail bleeding times and impaired P-Selectin externalisation, RANTES release and thrombin-induced platelet-neutrophil aggregate formation. These changes were associated with an increase in size and an abnormal distribution of bone marrow megakaryocytes within the vascular niche and were directly correlated with the plasmatic and bone marrow IFNβ levels. All these effects were absent in genetically modified mice lacking the IFN I receptor. Our results suggest that IFN I is the central mediator of poly (I:C)-induced thrombocytopenia and platelet dysfunction and indicate that these abnormalities are due to changes in the last stages of megakaryocyte development. These data provide new evidence for the role of IFN I in megakaryocyte distribution in the bone marrow niches and its influence on thrombopoiesis and haemostasis. PMID:26134179

  16. 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)

  17. 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.

  18. 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...

  19. Therapeutic Protein Aggregation: Mechanisms, Design, and Control

    PubMed Central

    Roberts, Christopher J.

    2014-01-01

    While it is well known that proteins are only marginally stable in their folded states, it is often less well appreciated that most proteins are inherently aggregation-prone in their unfolded or partially unfolded states, and the resulting aggregates can be extremely stable and long-lived. For therapeutic proteins, aggregates are a significant risk factor for deleterious immune responses in patients, and can form via a variety of mechanisms. Controlling aggregation using a mechanistic approach may allow improved design of therapeutic protein stability, as a complement to existing design strategies that target desired protein structures and function. Recent results highlight the importance of balancing protein environment with the inherent aggregation propensities of polypeptide chains. PMID:24908382

  20. 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…

  1. Aggregation Pheromone System: A Real-parameter Optimization Algorithm using Aggregation Pheromones as the Base Metaphor

    NASA Astrophysics Data System (ADS)

    Tsutsui, Shigeyosi

    This paper proposes an aggregation pheromone system (APS) for solving real-parameter optimization problems using the collective behavior of individuals which communicate using aggregation pheromones. APS was tested on several test functions used in evolutionary computation. The results showed APS could solve real-parameter optimization problems fairly well. The sensitivity analysis of control parameters of APS is also studied.

  2. Synthetic lightweight aggregate from cool water slag: Bench-scale confirmation tests

    SciTech Connect

    Choudhry, V.; Hadley, S.R. )

    1990-05-01

    This report analyzes the potential for production of synthetic lightweight aggregate (SLA) from a Texaco coal gasification solid residue. The objective of the project was to develop a replacement for conventional lightweight aggregates typically derived from expanded clays and shales or natural lightweight aggregates. The sequence of tests performed to develop SLA from slag began with the crushing of samples of slag, followed by either extrusion or pelletization. The level of clay binder required for sufficient aggregate strength was evaluated. Using a tube furnace, expansion characteristics were studied as a function of temperature and residence time. Next, a large batch of SLA was produced in a muffle furnace and used to form concrete test cylinders. The unit weight of the resultant concrete was 105 lb/ft{sup 3}, with a compressive strength of 3100 psi, which meets the requirements specified in ASTM C 330 for lightweight aggregate of a comparable density. When the same sequence of tests was performed using a slag from which the bulk of the char had been removed, the concrete test cylinders showed an improved relationship between strength and density. Based on the results of bench-scale tests and the similarity to conventional LWA production, the conceptual design of an SLA processing plant was formulated. A comparative estimate of operating costs was prepared by analyzing data from plants using clays and shales to produce lightweight aggregates. 24 refs., 15 figs., 17 tabs.

  3. 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)

  4. Exquisite 1D Assemblies Arising from Rationally Designed Asymmetric Donor-Acceptor Architectures Exhibiting Aggregation-Induced Emission as a Function of Auxiliary Acceptor Strength.

    PubMed

    Singh, Roop Shikha; Mukhopadhyay, Sujay; Biswas, Arnab; Pandey, Daya Shankar

    2016-01-11

    One-dimensional nanostructures with aggregation-induced emission (AIE) properties have been fabricated to keep the pace with growing demand from optoelectronics applications. The compounds 2-[4-(4-methylpiperazin-1-yl)benzylidene]malononitrile (PM1), 2-{4-[4-(pyridin-2-yl)piperazin-1-yl]-benzylidene}malononitrile (PM2), and 2-{4-[4-(pyrimidin-2-yl)piperazin-1-yl]benzylidene}malononitrile (PM3) have been designed and synthesized by melding piperazine and dicyanovinylene to investigate AIE in an asymmetric donor-acceptor (D-A) construct of A'-D-π-A- topology. The synthetic route has been simplified by using phenylpiperazine as a weak donor (D), dicyanovinylene as an acceptor (A), and pyridyl/pyrimidyl groups (PM2/PM3) as auxiliary acceptors (A'). It has been established that A' plays a vital role in triggering AIE in these compounds because the same D-A construct led to aggregation-caused quenching upon replacing A' with an electron-donating ethyl group (PM1). Moreover, the effect of restricted intramolecular rotation and twisted intramolecular charge transfer on the mechanism of AIE has also been investigated. Furthermore, it has been clearly shown that the optical disparities of these A'-D-π-A architectures are a direct consequence of comparative A' strength. Single-crystal X-ray analyses provided justification for role of intermolecular interactions in aggregate morphology. Electrochemical and theoretical studies affirmed the effect of the A' strength on the overall properties of the A'-D-π-A system. PMID:26615814

  5. Novel functional conjugative hyperbranched polymers with aggregation-induced emission: synthesis through one-pot "A2+B4" polymerization and application as explosive chemsensors and PLEDs.

    PubMed

    Wu, Wenbo; Ye, Shanghui; Yu, Gui; Liu, Yunqi; Qin, Jingui; Li, Zhen

    2012-01-01

    With the aim to develop new tetraphenylethylene (TPE)-based conjugated hyperbranched polymer, TPE units, one famous aggregation-induced emission (AIE) active group, are utilized to construct hyperbranched polymers with three other aromatic blocks, through an "A2+B4" approach by using one-pot Suzuki polycondensation reaction. These three hyperbranched polymers exhibit interesting AIEE behavior and act as explosive chemsensors with high sensitivity both in the nanoparticles and solid states. This is the first report of the AIE activity of the TPE-based conjugated hyperbranched polymers. Their corresponding PLED devices also demonstrate good performance. PMID:22134953

  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. An Intein-based Strategy for the Production of Tag-free Huntingtin Exon 1 Proteins Enables New Insights into the Polyglutamine Dependence of Httex1 Aggregation and Fibril Formation.

    PubMed

    Vieweg, Sophie; Ansaloni, Annalisa; Wang, Zhe-Ming; Warner, John B; Lashuel, Hilal A

    2016-06-01

    The first exon of the Huntingtin protein (Httex1) is one of the most actively studied Htt fragments because its overexpression in R6/2 transgenic mice has been shown to recapitulate several key features of Huntington disease. However, the majority of biophysical studies of Httex1 are based on assessing the structure and aggregation of fusion constructs where Httex1 is fused to large proteins, such as glutathione S-transferase, maltose-binding protein, or thioredoxin, or released in solution upon in situ cleavage of these proteins. Herein, we report an intein-based strategy that allows, for the first time, the rapid and efficient production of native tag-free Httex1 with polyQ repeats ranging from 7Q to 49Q. Aggregation studies on these proteins enabled us to identify interesting polyQ-length-dependent effects on Httex1 oligomer and fibril formation that were previously not observed using Httex1 fusion proteins or Httex1 proteins produced by in situ cleavage of fusion proteins. Our studies revealed the inability of Httex1-7Q/15Q to undergo amyloid fibril formation and an inverse correlation between fibril length and polyQ repeat length, suggesting possible polyQ length-dependent differences in the structural properties of the Httex1 aggregates. Altogether, our findings underscore the importance of working with tag-free Httex1 proteins and indicate that model systems based on non-native Httex1 sequences may not accurately reproduce the effect of polyQ repeat length and solution conditions on Httex1 aggregation kinetics and structural properties. PMID:27002149

  8. Mars: New Determination of Impact Crater Production Function Size Distribution

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.

    2006-12-01

    Several authors have questioned our knowledge of Martian impact crater production function size-frequency distribution (PFSFD), especially at small diameters D. Plescia (2005) questioned whether any area of Mars shows size distributions used for estimating crater retention ages on Mars. McEwen et al. (2005) and McEwen and Bierhaus (2006) suggested existing PFSFD’s are hopelessly confused by the presence of secondaries, and that my isochrons give primary crater densities off by factors of several thousand at small D. In 2005, I addressed some of these concerns, noting my curves do not estimate primary crater densities per se, but show total numbers of primaries + semi-randomly “distant secondaries” (negating many McEwen et al. critiques). In 2006 I have conducted new crater counts on a PFSFD test area suggested by Ken Tanaka. This area shows young lava flows of similar crater density, west of Olympus Mons (around 30 deg N, 100 deg W). Multiple crater counts were made on several adjacent Odyssey THEMIS images and MGS MOC images, giving the SFD over a range of 11m

  9. 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…

  10. Aggregation of Polyglutamine-expanded Ataxin 7 Protein Specifically Sequesters Ubiquitin-specific Protease 22 and Deteriorates Its Deubiquitinating Function in the Spt-Ada-Gcn5-Acetyltransferase (SAGA) Complex.

    PubMed

    Yang, Hui; Liu, Shuai; He, Wen-Tian; Zhao, Jian; Jiang, Lei-Lei; Hu, Hong-Yu

    2015-09-01

    Human ataxin 7 (Atx7) is a component of the deubiquitination module (DUBm) in the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex for transcriptional regulation, and expansion of its polyglutamine (polyQ) tract leads to spinocerebellar ataxia type 7. However, how polyQ expansion of Atx7 affects DUBm function remains elusive. We investigated the effects of polyQ-expanded Atx7 on ubiquitin-specific protease (USP22), an interacting partner of Atx7 functioning in deubiquitination of histone H2B. The results showed that the inclusions or aggregates formed by polyQ-expanded Atx7 specifically sequester USP22 through their interactions mediated by the N-terminal zinc finger domain of Atx7. The mutation of the zinc finger domain in Atx7 that disrupts its interaction with USP22 dramatically abolishes sequestration of USP22. Moreover, polyQ expansion of Atx7 decreases the deubiquitinating activity of USP22 and, consequently, increases the level of monoubiquitinated H2B. Therefore, we propose that polyQ-expanded Atx7 forms insoluble aggregates that sequester USP22 into a catalytically inactive state, and then the impaired DUBm loses the function to deubiquitinate monoubiquitinated histone H2B or H2A. This may result in dysfunction of the SAGA complex and transcriptional dysregulation in spinocerebellar ataxia type 7 disease. PMID:26195632

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:25545358

  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. PMID:27236402

  16. 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

  17. 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

  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. The Nation's top 25 construction aggregates producers

    USGS Publications Warehouse

    Willett, Jason Christopher

    2013-01-01

    U.S. production of construction aggregates in 2011 was 2.17 billion short tons, valued at $17.2 billion, free on board (f.o.b.) at plant. Construction aggregates production decreased by 37 percent, and the associated value decreased by 25 percent, compared with the record highs reported in 2006. In 2011, construction aggregates production increased for the first time since 2006, owing to a very slight increase in the production of both construction sand and gravel and crushed stone. The average unit value, which is the f.o.b. at plant price of a ton of material, increased slightly, but is still less than the average unit value of two years prior.

  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. PMID:26124064

  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. Urea and methylamine effects on rabbit muscle phosphofructokinase. Catalytic stability and aggregation state as a function of pH and temperature.

    PubMed

    Hand, S C; Somero, G N

    1982-01-25

    The effects of urea and several methylamine solutes on the catalytic stability and aggregation properties of rabbit muscle phosphofructokinase were assessed at physiologically realistic concentrations of the solutes under several pH and temperature regimes. The loss of catalytic activity observed under conditions of pH-induced cold lability was significantly reduced in the presence of trimethylamine-N-oxide, N-trimethylglycine and N-methylglycine (order of decreasing effectiveness). The concentration-dependent methylamine stabilization of the enzyme, seen with as little as 50 mM trimethylamine-N-oxide, was accompanied by increased aggregation of the enzyme to molecular weights greater than the tetramer (polytetramer) as solute concentration was raised to 400 mM. At pH 6.5-6.7 and 25 degrees C, concentrations of urea greater than 25 mM promoted a time-dependent inactivation of the enzyme which was enhanced at lower temperatures. The urea sensitivity of the enzyme exhibited with 0.8 M urea for 1 h at pH 8.0 did not result in measurable inactivation. The fluorescence emission wavelength maximum of the enzyme was shifted to longer wavelengths and the fluorescence intensity was increased as pH was lowered to 7.0, suggesting the occurrence of a protein conformation change as specific amino acid residues of the tetramer became protonated. Measurements of enzyme light scattering indicated that perturbation by urea was correlated with tetramer dissociation, which was irreversible by dialysis at 25 degrees C. The urea and methylamine influences on phosphofructokinase activity and structure were not counteracting. The synergistic interactions among pH, temperature, and solutes observed with phosphofructokinase are compared to effects on other associating-dissociating protein systems in order to evaluate possible mechanisms of action of these low molecular weight solutes. PMID:6459323

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Language Production as a Function of Social Distance.

    ERIC Educational Resources Information Center

    Silverman, Thalia Pappas

    The need to find which social contexts elicit children's fullest language repertoire generated this study of the effects of three social distance variables on language production, as measured by mean length of communication unit, vocabulary diversity, and use of black English. The social distance variables investigated included race and sex of…

  8. 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...

  9. Examining the Function of Visual Feedback in Text Production.

    ERIC Educational Resources Information Center

    Hull, Glynda A.; Smith, William L.

    Composing is controlled by information feedback from prior behavior which serves to influence future behavior. This model posits movement toward a desired end product through a continual interchange of writing and examining and evaluating what has been written against internal standards. A study was conducted to determine the extent to which…

  10. Influence of surface modification on structure formation and micromechanical properties of spray-dried silica aggregates.

    PubMed

    Zellmer, Sabrina; Lindenau, Maylin; Michel, Stephanie; Garnweitner, Georg; Schilde, Carsten

    2016-02-15

    Spray drying processes were utilized for the production of hierarchical materials with defined structures. The structure formation during the spray drying process and the micromechanical properties of the obtained aggregates depend on the particle-particle interactions, the primary particle size and morphology as well as the process parameters of the spray drying process. Hence, the effect of different primary particle systems prepared as stable dispersions with various surface modifications were investigated on the colloidal structure formation and the micromechanical properties of silica particles as model aggregates and compared to theoretical considerations. The obtained results show that the structure formation of aggregates during the spray drying process for stable suspensions is almost independent on the functional groups present at the particle surface. Further, the mechanical properties of these aggregates differ considerably with the content of the bound ligand. This allows the defined adjustment of the aggregate properties, such as the strength and surface properties, as well as the formation of defined hierarchical aggregate structures. PMID:26619128

  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. PMID:26584453

  12. 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)

  13. 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

  14. 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

  15. A new approach to the representation of trigonometric and hyperbolic functions by infinite products

    NASA Astrophysics Data System (ADS)

    Melnikov, Yu. A.

    2008-08-01

    An innovative technique is developed for obtaining infinite product representations for some elementary functions. The technique is based on the comparison of alternative expressions of Green's functions constructed by two different methods. Some standard boundary value problems are considered posed for two-dimensional Laplace equation on regions of a regular configuration. Classical closed analytic form of Green's functions for such problems are compared against those obtained by the method of images in the form of infinite products. This yields a number of new infinite product representations for trigonometric and hyperbolic functions.

  16. Production of functionalized biopolyester granules by recombinant Lactococcus lactis.

    PubMed

    Mifune, Jun; Grage, Katrin; Rehm, Bernd H A

    2009-07-01

    Many bacteria are naturally capable of accumulating biopolyesters composed of 3-hydroxy fatty acids as intracellular inclusions, which serve as storage granules. Recently, these inclusions have been considered as nano-/microbeads with surface-attached proteins, which can be engineered to display various protein-based functions that are suitable for biotechnological and biomedical applications. In this study, the food-grade, generally-regarded-as-safe gram-positive organism Lactococcus lactis was engineered to recombinantly produce the biopolyester poly(3-hydroxybutyrate) and the respective intracellular inclusions. The codon-optimized polyhydroxybutyrate biosynthesis operon phaCAB from Cupriavidus necator was expressed using the nisin-controlled gene expression system. Recombinant L. lactis accumulated up to 6% (wt/wt) poly(3-hydroxybutyrate) of cellular dry weight. Poly(3-hydroxybutyrate) granules were isolated and analyzed with respect to bound proteins using biochemical methods and with respect to shape/size using transmission electron microscopy. The immunoglobulin G (IgG) binding ZZ domain of Staphylococcus aureus protein A was chosen as an exemplary functionality to be displayed at the granule surface by fusing it to the N terminus of the granule-associated poly(3-hydroxybutyrate) synthase. The presence of the fusion protein at the surface of isolated granules was confirmed by peptide fingerprinting using matrix-assisted laser desorption ionization-time of flight (mass spectrometry). The functionality of the ZZ domain-displaying granules was demonstrated by enzyme-linked immunosorbent assay and IgG affinity purification. In both assays, the ZZ beads from recombinant L. lactis performed at least equally to ZZ beads from Escherichia coli. Overall, in this study it was shown that recombinant L. lactis can be used to manufacture endotoxin-free poly(3-hydroxybutyrate) beads with surface functionalities that are suitable for biomedical applications. PMID:19465535

  17. Production of functional pita bread using date seed powder.

    PubMed

    Platat, Carine; Habib, Hosam M; Hashim, Isameldin Bashir; Kamal, Hina; AlMaqbali, Fatima; Souka, Usama; Ibrahim, Wissam H

    2015-10-01

    Functional foods represent a novel approach to prevent diet-related diseases. Due to its excellent nutritional and antioxidant properties, date seed was used to develop functional pita bread. Flour was replaced by 5, 10, 15 and 20 % date seed powder. Regular and whole wheat pita breads were the references. Results clearly showed that date seed powder containing bread contained comparable dietary fibers levels as in whole wheat bread and higher levels of flavonoids and phenolics. Date seed powder containing breads were particularly rich in flavan-3-ols whereas reference breads did not contain any of them and only a limited amount of other phenolic compounds. They also exhibited a much higher antioxidant capacity. Additionally, compared to regular bread, acrylamide level was significantly lower in 5 % date seed powder containing bread, and lower in all date seed powder containing breads compared to whole wheat bread. Date seed powder supplemented bread appears as a promising functional ingredient to prevent chronic diseases. PMID:26396382

  18. 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. PMID:27460534

  19. 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…

  20. Double Functions of Knowledge Production in Education: Enlightenment and Emancipation or Dominance and Domestication.

    ERIC Educational Resources Information Center

    Kim, Kyung Hi

    1994-01-01

    Many critical educators claim that knowledge construction and production in education are tools for dominating and domesticating people, not enlightening or emancipating them. This article analyzes the nature of knowledge and the subject/object relationship in knowledge production. The contradictory functions of knowledge production are best…

  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. PMID:16426748

  2. Functional characteristics of Lactobacillus spp. from traditional Maasai fermented milk products in Kenya.

    PubMed

    Mathara, Julius Maina; Schillinger, Ulrich; Guigas, Claudia; Franz, Charles; Kutima, Phillip Museve; Mbugua, Samuel K; Shin, H-K; Holzapfel, Wilhelm H

    2008-08-15

    In this study functional characteristics of 23 representative Lactobacillus strains isolated from the Maasai traditional fermented milk 'Kule naoto' were determined. The Lb. acidophilus group strains showed resistance to gastric juice and bile. In addition, some Lb. acidophilus strains expressed bile salt hydrolase activity, and had ability to assimilate cholesterol in vitro. In-vitro adhesion to HT29 MTX cells of up to 70% was recorded. Lb. fermentum strains showed almost 100% survival under simulated stomach acidic conditions and physiological salt concentrations of bile salts, hydrophobicity values were over 80%. Most strains of the Lb. casei and Lb. acidophilus groups showed aggregation abilities of above 50%. Many strains expressed a protective effect against N-methyl-N'-nitro-N-nitrosoguanidine induced DNA damage according to the 'comet assay' and none was virulent. The antibiotic minimum inhibitory concentration of selected strains was established. According to these results, the Lactobacillus spp associated with 'Kule naoto', contain potentially probiotic (functional) strains. PMID:18539351

  3. pH-controlled aggregation polymorphism of amyloidogenic Aβ(16-22): insights for obtaining peptide tapes and peptide nanotubes, as function of the N-terminal capping moiety.

    PubMed

    Elgersma, Ronald C; Kroon-Batenburg, Loes M J; Posthuma, George; Meeldijk, Johannes D; Rijkers, Dirk T S; Liskamp, Rob M J

    2014-12-17

    Peptide and protein self-assembly resulting in the formation of amyloidogenic aggregates is generally thought of as a pathological event associated with severe diseases. However, amyloid formation may also provide a basis for advanced bionanomaterials, since amyloid fibrils combine unique material-like properties that make them very useful for design of new types of conducting nanowires, bioactive ligands, and biodegradable coatings as drug-encapsulating materials. The morphology of the supramolecular aggregates determines the properties and application range of these bionanomaterials. An important parameter to control the supramolecular morphology, is the overall charge of the peptide, which is related to the pH of the environment. Herein, we describe the design, synthesis and morphological analysis of a series of N-terminally functionalized Aβ(16-22) peptides (∼Lys-Leu-Val-Phe-Phe-Ala-Glu-OH), that underwent a pH-induced polymorphism, ranging from lamellar sheets, helical tapes, peptide nanotubes, and amyloid fibrils as was observed by transmission electron microscopy. Infrared spectroscopy and wide angle X-ray scattering studies showed that peptide self-assembly was driven by β-sheet formation, and that the supramolecular morphology was directed by subtle variations in electrostatic interactions. Finally, a structural model and hierarchy of self-assembly of a peptide nanotube, assembled at pH 1, is proposed. PMID:25087966

  4. Density functional theory and Raman spectroscopy applied to structure and vibrational mode analysis of 1,1',3,3'-tetraethyl-5,5',6,6'-tetrachloro- benzimidazolocarbocyanine iodide and its aggregate.

    PubMed

    Aydin, Metin; Dede, Özge; Akins, Daniel L

    2011-02-14

    We have measured electronic and Raman scattering spectra of 1,1',3,3'-tetraethyl-5,5',6,6'-tetrachloro-benzimidazolocarbocyanine iodide (TTBC) in various environments, and we have calculated the ground state geometric and spectroscopic properties of the TTBC cation in the gas and solution phases (e.g., bond distances, bond angles, charge distributions, and Raman vibrational frequencies) using density functional theory. Our structure calculations have shown that the ground state equilibrium structure of a cis-conformer lies ∼200 cm(-1) above that of a trans-conformer and both conformers have C(2) symmetry. Calculated electronic transitions indicate that the difference between the first transitions of the two conformers is about 130 cm(-1). Raman spectral assignments of monomeric- and aggregated-TTBC cations have been aided by density functional calculations at the same level of the theory. Vibrational mode analyses of the calculated Raman spectra reveal that the observed Raman bands above 700 cm(-1) are mainly associated with the in-plane deformation of the benzimidazolo moieties, while bands below 700 cm(-1) are associated with out-of-plane deformations of the benzimidazolo moieties. We have also found that for the nonresonance excited experimental Raman spectrum of aggregated-TTBC cation, the Raman bands in the higher-frequency region are enhanced compared with those in the nonresonance spectrum of the monomeric cation. For the experimental Raman spectrum of the aggregate under resonance excitation, however, we find new Raman features below 600 cm(-1), in addition to a significantly enhanced Raman peak at 671 cm(-1) that are associated with out-of-plane distortions. Also, time-dependent density functional theory calculations suggest that the experimentally observed electronic transition at ∼515 nm (i.e., 2.41 eV) in the absorption spectrum of the monomeric-TTBC cation predominantly results from the π → π∗ transition. Calculations are further interpreted

  5. 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.

  6. A Comparative Study of Spatial Aggregation Methodologies under the BioEarth Framework

    NASA Astrophysics Data System (ADS)

    Chandrasekharan, B.; Rajagopalan, K.; Malek, K.; Stockle, C. O.; Adam, J. C.; Brady, M.

    2014-12-01

    The increasing probability of water resource scarcity due to climate change has highlighted the need for adopting an economic focus in modelling water resource uses. Hydro-economic models, developed by integrating economic optimization with biophysical crop models, are driven by the economic value of water, revealing it's most efficient uses and helping policymakers evaluate different water management strategies. One of the challenges in integrating biophysical models with economic models is the difference in the spatial scales in which they operate. Biophysical models that provide crop production functions typically run at smaller scale than economic models, and substantial spatial aggregation is required. However, any aggregation introduces a bias, i.e., a discrepancy between the functional value at the higher spatial scale and the value at the spatial scale of the aggregated units. The objective of this work is to study the sensitivity of net economic benefits in the Yakima River basin (YRB) to different spatial aggregation methods for crop production functions. The spatial aggregation methodologies that we compare involve agro-ecological zones (AEZs) and aggregation levels that reflect water management regimes (e.g. irrigation districts). Aggregation bias can distort the underlying data and result in extreme solutions. In order to avoid this we use an economic optimization model that incorporates the synthetic and historical crop mixes approach (Onal & Chen, 2012). This restricts the solutions between the weighted averages of historical and simulated feasible planting decisions, with the weights associated with crop mixes being treated as endogenous variables. This study is focused on 5 major irrigation districts of the YRB in the Pacific Northwest US. The biophysical modeling framework we use, BioEarth, includes the coupled hydrology and crop growth model, VIC-Cropsyst and an economic optimization model. Preliminary findings indicate that the standard approach

  7. 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.

  8. 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. PMID:20854989

  9. Integration of complex optical functionality in a production CMOS process

    NASA Astrophysics Data System (ADS)

    Gunn, Lawrence C., III

    Optical functionality has been developed within the confines of an existing CMOS process. As of this writing, 10Gigabit modulators, electrically tunable optical filters, waveguides, and grating coupler technology have been successfully implemented alongside the existing transistors in the Freescale Hip7SOI process. This technology will be used to manufacture high bandwidth optical interconnections directly on silicon chips, allowing a new type of network and computing infrastructure to be developed. This work is covered in two distinct phases. First, the exploratory work done to gain experience with high index contrast silicon waveguides primarily served to uncover challenges related with simulation of these devices, and with the practical limitations of efficiently coupling the resulting waveguide devices with the outside world. The second phase began as the grating coupler emerged to address the coupling challenge. It became feasible to conceive of a commercially viable technology based on silicon photonics. The coupler has been evolved to a high level, currently achieving coupling loss of less than 1dB. Once the light is on chip, filtering and modulation technology are implemented. The reverse-biased plasma dispersion modulator has a 3dB roll-off of 10GHz, and an insertion loss less than 5dB. Optical filters based on ring resonators, arrayed waveguide gratings, and interleavers have all been implemented, often with world record performance, and many of the devices have been made electronically tunable to compensate for manufacturing variations and environmental excursions. Finally, circuitry has been designed and constructed on the same die with the optical functionality, fully demonstrating the ability to achieve monolithic integration of these devices.

  10. LPS ligand and culture additives improve production of monomeric MD-1 and 2 in Pichia pastoris by decreasing aggregation and intermolecular disulfide bonding

    PubMed Central

    Mengwasser, Kristen E.; Bryant, Clare E.; Gay, Nick J.; Gangloff, Monique

    2011-01-01

    Myeloid differentiation proteins MD-1 and MD-2 have both been shown to form a heterogeneous collection of oligomers when expressed in absence of their respective receptor, RP105 and TLR4. The biological relevance of these oligomers is not clear. Only monomeric proteins have been found to be active and able to trigger an immune response to endotoxin by modulating the TLR4 pathway. In this study, we produced variants of MD-1 and MD-2 in Pichia pastoris. To minimize the time and expense of initial expression tests, small-scale cultures have been set up to allow the rapid identification of the highest expressing clone and the optimal expression conditions. The expression vectors used, the site of linearization and the locus of integration affected the yield of transformation. Next we screened culture additives and found that they significantly increased the fraction of monomeric proteins secreted in the culture medium (up to 15% of the total MD protein produced). We confirmed their presence by size-exclusion chromatography. Optimal anti-aggregation agents were protein-dependent except for LPS that presented stabilizing effects for all MD proteins. Contrary to previous reports, this study suggests that MD-1 can bind to LPS. PMID:21130168

  11. LPS ligand and culture additives improve production of monomeric MD-1 and 2 in Pichia pastoris by decreasing aggregation and intermolecular disulfide bonding.

    PubMed

    Mengwasser, Kristen E; Bryant, Clare E; Gay, Nick J; Gangloff, Monique

    2011-04-01

    Myeloid differentiation proteins MD-1 and MD-2 have both been shown to form a heterogeneous collection of oligomers when expressed in absence of their respective receptor, RP105 and TLR4. The biological relevance of these oligomers is not clear. Only monomeric proteins have been found to be active and able to trigger an immune response to endotoxin by modulating the TLR4 pathway. In this study, we produced variants of MD-1 and MD-2 in Pichia pastoris. To minimize the time and expense of initial expression tests, small-scale cultures have been set up to allow the rapid identification of the highest expressing clone and the optimal expression conditions. The expression vectors used, the site of linearization and the locus of integration affected the yield of transformation. Next we screened culture additives and found that they significantly increased the fraction of monomeric proteins secreted in the culture medium (up to 15% of the total MD protein produced). We confirmed their presence by size-exclusion chromatography. Optimal anti-aggregation agents were protein-dependent except for LPS that presented stabilizing effects for all MD proteins. Contrary to previous reports, this study suggests that MD-1 can bind to LPS. PMID:21130168

  12. 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. PMID:23673273

  13. 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.

  14. Functional Heterologous Production of Reductive Dehalogenases from Desulfitobacterium hafniense Strains

    PubMed Central

    Mac Nelly, Anita; Kai, Marco; Svatoš, Aleš; Diekert, Gabriele

    2014-01-01

    The anaerobic dehalogenation of organohalides is catalyzed by the reductive dehalogenase (RdhA) enzymes produced in phylogenetically diverse bacteria. These enzymes contain a cobamide cofactor at the active site and two iron-sulfur clusters. In this study, the tetrachloroethene (PCE) reductive dehalogenase (PceA) of the Gram-positive Desulfitobacterium hafniense strain Y51 was produced in a catalytically active form in the nondechlorinating, cobamide-producing bacterium Shimwellia blattae (ATCC 33430), a Gram-negative gammaproteobacterium. The formation of recombinant catalytically active PceA enzyme was significantly enhanced when its dedicated PceT chaperone was coproduced and when 5,6-dimethylbenzimidazole and hydroxocobalamin were added to the S. blattae cultures. The experiments were extended to D. hafniense DCB-2, a reductively dehalogenating bacterium harboring multiple rdhA genes. To elucidate the substrate spectrum of the rdhA3 gene product of this organism, the recombinant enzyme was tested for the conversion of different dichlorophenols (DCP) in crude extracts of an RdhA3-producing S. blattae strain. 3,5-DCP, 2,3-DCP, and 2,4-DCP, but not 2,6-DCP and 3,4-DCP, were reductively dechlorinated by the recombinant RdhA3. In addition, this enzyme dechlorinated PCE to trichloroethene at low rates. PMID:24814779

  15. 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.

  16. Particle aggregation mechanisms in ionic liquids.

    PubMed

    Szilagyi, Istvan; Szabo, Tamas; Desert, Anthony; Trefalt, Gregor; Oncsik, Tamas; Borkovec, Michal

    2014-05-28

    Aggregation of sub-micron and nano-sized polystyrene latex particles was studied in room temperature ionic liquids (ILs) and in their water mixtures by time-resolved light scattering. The aggregation rates were found to vary with the IL-to-water molar ratio in a systematic way. At the water side, the aggregation rate is initially small, but increases rapidly with increasing IL content, and reaches a plateau value. This behaviour resembles simple salts, and can be rationalized by the competition of double-layer and van der Waals forces as surmised by the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). At the IL side, aggregation slows down again. Two generic mechanisms could be identified to be responsible for the stabilization in ILs, namely viscous stabilization and solvation stabilization. Viscous stabilization is important in highly viscous ILs, as it originates from the slowdown of the diffusion controlled aggregation due to the hindrance of the diffusion in a viscous liquid. The solvation stabilization mechanism is system specific, but can lead to a dramatic slowdown of the aggregation rate in ILs. This mechanism is related to repulsive solvation forces that are operational in ILs due to the layering of the ILs close to the surfaces. These two stabilization mechanisms are suspected to be generic, as they both occur in different ILs, and for particles differing in surface functionalities and size. PMID:24727976

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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. PMID:8406976

  2. A Product of Heme Catabolism Modulates Bacterial Function and Survival

    PubMed Central

    Nobles, Christopher L.; Green, Sabrina I.; Maresso, Anthony W.

    2013-01-01

    Bilirubin is the terminal metabolite in heme catabolism in mammals. After deposition into bile, bilirubin is released in large quantities into the mammalian gastrointestinal (GI) tract. We hypothesized that intestinal bilirubin may modulate the function of enteric bacteria. To test this hypothesis, we investigated the effect of bilirubin on two enteric pathogens; enterohemorrhagic E. coli (EHEC), a Gram-negative that causes life-threatening intestinal infections, and E. faecalis, a Gram-positive human commensal bacterium known to be an opportunistic pathogen with broad-spectrum antibiotic resistance. We demonstrate that bilirubin can protect EHEC from exogenous and host-generated reactive oxygen species (ROS) through the absorption of free radicals. In contrast, E. faecalis was highly susceptible to bilirubin, which causes significant membrane disruption and uncoupling of respiratory metabolism in this bacterium. Interestingly, similar results were observed for other Gram-positive bacteria, including B. cereus and S. aureus. A model is proposed whereby bilirubin places distinct selective pressure on enteric bacteria, with Gram-negative bacteria being protected from ROS (positive outcome) and Gram-positive bacteria being susceptible to membrane disruption (negative outcome). This work suggests bilirubin has differential but biologically relevant effects on bacteria and justifies additional efforts to determine the role of this neglected waste catabolite in disease processes, including animal models. PMID:23935485

  3. 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

  4. Health, safe water and sanitation: a cross-sectional health production function for central Java, Indonesia.

    PubMed Central

    Wibowo, D.; Tisdell, C.

    1993-01-01

    The study describes the development of health production functions and their application in the evaluation of the health impacts of investments in safe water and sanitation. For this purpose, data on the morbidity of waterborne diseases and diarrhoea were collected from medical records in the province of Central Java, Indonesia. A reciprocal production function was found to fit the data best. The health production functions exhibit constant return to scale, i.e., a simultaneous m-fold increase in both safe water and sanitation coverage produces a 1-1/m decrease in morbidity. Safe water was found to be more important for health than the sanitary disposal of excreta. PMID:8490988

  5. 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.

  6. Development of functional canned and pouched tuna products added inulin for commercial production.

    PubMed

    Rueangwatcharin, U; Wichienchot, S

    2015-08-01

    Four formulas of canned tuna in spring water and tuna in mayonnaise and pouched tuna in salad cream and tuna in thousand island cream with added inulin were developed for commercial production. The effects of the addition of a prebiotic (inulin, Orafti®-HP) on the color and sensory properties of these products were studied. For inulin concentrations studied (3, 5, 7 and 10 %, w/w) caused more intensed yellow and red colors. Hedonic sensory values of tuna packed in spring water and in mayonnaise showed no significant differences (p > 0.05) among products with different inulin addition levels (3, 5, 7 and 10 %, w/w) in terms of color, flavor, sweetness and overall characteristics. However, when packed in thousand island cream, significant differences (p < 0.05) in color and overall characteristics were found when inulin was added higher than 7 %. Tuna in salad cream showed significant differences (p < 0.05) in color, flavor, sweetness and overall characteristics at higher than 7 % inulin. The panelists showed acceptable overall liking scores at upto 7 % inulin of all tuna products. The thermal sterilization process resulted in approximately 20 % decrease in final inulin content. The calculated residual fructans of finished products at shelf life of 3 years were 3.01, 2.78, 2.90 and 2.84 % for tuna in spring water, tuna in mayonnaise, tuna in thousand island and tuna in salad cream, respectively. Considering formula cost in a commercial production and the recommended daily intake (RDI) of inulin in the finished product at end of shelf life (≥3 g/d), an addition of 5 % inulin for tuna in spring water and 7 % inulin for tuna in mayonnaise, tuna in thousand island and tuna in salad cream are recommended. PMID:26243930

  7. Production of Printed Indexes of Chemical Reactions. I. Analysis of Functional Group Interconversions

    ERIC Educational Resources Information Center

    Clinging, R.; Lynch, M. F.

    1973-01-01

    A program is described which identifies functional group interconversion reactions, hydrogenations, and dehydrogenations in a data base containing structures encoded as Wiswesser Line Notations. Production of the data base is briefly described. (17 references) (Authors)

  8. 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

  9. Ozone production rates as a function of NOx abundances and HOx production rates in the Nashville urban plume

    NASA Astrophysics Data System (ADS)

    Thornton, J. A.; Wooldridge, P. J.; Cohen, R. C.; Martinez, M.; Harder, H.; Brune, W. H.; Williams, E. J.; Roberts, J. M.; Fehsenfeld, F. C.; Hall, S. R.; Shetter, R. E.; Wert, B. P.; Fried, A.

    2002-06-01

    Tropospheric O3 concentrations are functions of the chain lengths of NOx (NOx ≡ NO + NO2) and HOx (HOx ≡ OH + HO2 + RO2) radical catalytic cycles. For a fixed HOx source at low NOx concentrations, kinetic models indicate the rate of O3 production increases linearly with increases in NOx concentrations (NOx limited). At higher NOx concentrations, kinetic models predict ozone production rates decrease with increasing NOx (NOx saturated). We present observations of NO, NO2, O3, OH, HO2, H2CO, actinic flux, and temperature obtained during the 1999 Southern Oxidant Study from June 15 to July 15, 1999, at Cornelia Fort Airpark, Nashville, Tennessee. The observations are used to evaluate the instantaneous ozone production rate (PO3) as a function of NO abundances and the primary HOx production rate (PHOx). These observations provide quantitative evidence for the response of PO3 to NOx. For high PHOx (0.5 < PHOx < 0.7 ppt/s), O3 production at this site increases linearly with NO to ~500 ppt. PO3 levels out in the range 500-1000 ppt NO and decreases for NO above 1000 ppt. An analysis along chemical coordinates indicates that models of chemistry controlling peroxy radical abundances, and consequently PO3, have a large error in the rate or product yield of the RO2 + HO2 reaction for the classes of RO2 that predominate in Nashville. Photochemical models and our measurements can be forced into agreement if the product of the branching ratio and rate constant for organic peroxide formation, via RO2 + HO2 -> ROOH + O2, is reduced by a factor of 3-12. Alternatively, these peroxides could be rapidly photolyzed under atmospheric conditions making them at best a temporary HOx reservoir. This result implies that O3 production in or near urban areas with similar hydrocarbon reactivity and HOx production rates may be NOx saturated more often than current models suggest.

  10. Further evidence for the mandatory nature of polysaccharide debranching for the aggregation of semicrystalline starch and for overlapping functions of debranching enzymes in Arabidopsis leaves.

    PubMed

    Wattebled, Fabrice; Planchot, Véronique; Dong, Ying; Szydlowski, Nicolas; Pontoire, Bruno; Devin, Aline; Ball, Steven; D'Hulst, Christophe

    2008-11-01

    Four isoforms of debranching enzymes are found in the genome of Arabidopsis (Arabidopsis thaliana): three isoamylases (ISA1, ISA2, and ISA3) and a pullulanase (PU1). Each isoform has a specific function in the starch pathway: synthesis and/or degradation. In this work we have determined the levels of functional redundancy existing between these isoforms by producing and analyzing different combinations of mutations: isa3-1 pu1-1, isa1-1 isa3-1, and isa1-1 isa3-1 pu1-1. While the starch content strongly increased in the isa3-1 pu1-1 double mutant, the latter decreased by over 98% in the isa1-1 isa3-1 genotype and almost vanished in triple mutant combination. In addition, whereas the isa3-1 pu1-1 double mutant synthesizes starch very similar to that of the wild type, the structure of the residual starch present either in isa1-1 isa3-1 or in isa1-1 isa3-1 pu1-1 combination is deeply affected. In the same way, water-soluble polysaccharides that accumulate in the isa1-1 isa3-1 and isa1-1 isa3-1 pu1-1 genotypes display strongly modified structure compared to those found in isa1-1. Taken together, these results show that in addition to its established function in polysaccharide degradation, the activity of ISA3 is partially redundant to that of ISA1 for starch synthesis. Our results also reveal the dual function of pullulanase since it is partially redundant to ISA3 for degradation and to ISA1 for synthesis. Finally, x-ray diffraction analyses suggest that the crystallinity and the presence of the 9- to 10-nm repetition pattern in starch precisely depend on the level of debranching enzyme activity. PMID:18815382

  11. HIGH-FIBRE PRODUCTS: CONVERTING OATS TO HIGH-FIBRE PRODUCTS FOR USE IN FUNCTIONAL FOODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new generation of soluble beta-glucan product, called Nutrim-OB (OB, oat bran), was developed that qualified for a FDA health claim. Nutrim-OB was prepared by heat-shearing oat flour or bran aqueous slurry in series of treatments that solubilises oat beta-glucans but maintains basic bran composit...

  12. 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

  13. Planktonic Aggregates of Staphylococcus aureus Protect against Common Antibiotics

    PubMed Central

    Haaber, Jakob; Cohn, Marianne Thorup; Frees, Dorte; Andersen, Thorbjørn Joest; Ingmer, Hanne

    2012-01-01

    Bacterial cells are mostly studied during planktonic growth although in their natural habitats they are often found in communities such as biofilms with dramatically different physiological properties. We have examined another type of community namely cellular aggregates observed in strains of the human pathogen Staphylococcus aureus. By laser-diffraction particle–size analysis (LDA) we show, for strains forming visible aggregates, that the aggregation starts already in the early exponential growth phase and proceeds until post-exponential phase where more than 90% of the population is part of the aggregate community. Similar to some types of biofilm, the structural component of S. aureus aggregates is the polysaccharide intercellular adhesin (PIA). Importantly, PIA production correlates with the level of aggregation whether altered through mutations or exposure to sub-inhibitory concentrations of selected antibiotics. While some properties of aggregates resemble those of biofilms including increased mutation frequency and survival during antibiotic treatment, aggregated cells displayed higher metabolic activity than planktonic cells or cells in biofilm. Thus, our data indicate that the properties of cells in aggregates differ in some aspects from those in biofilms. It is generally accepted that the biofilm life style protects pathogens against antibiotics and the hostile environment of the host. We speculate that in aggregate communities S. aureus increases its tolerance to hazardous environments and that the combination of a biofilm-like environment with mobility has substantial practical and clinical importance. PMID:22815921

  14. 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...

  15. 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

  16. 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. PMID:26161440

  17. Photophoretic force on aggregate grains

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin S.; Kimery, Jesse B.; Wurm, Gerhard; de Beule, Caroline; Kuepper, Markus; Hyde, Truell W.

    2016-01-01

    The photophoretic force may impact planetary formation by selectively moving solid particles based on their composition and structure. This generates collision velocities between grains of different sizes and sorts the dust in protoplanetary discs by composition. This numerical simulation studied the photophoretic force acting on fractal dust aggregates of μm-scale radii. Results show that aggregates tend to have greater photophoretic drift velocities than spheres of similar mass or radii, though with a greater spread in the velocity. While the drift velocities of compact aggregates continue to increase as the aggregates grow larger in size, fluffy aggregates have drift velocities which are relatively constant with size. Aggregates formed from an initially polydisperse size distribution of dust grains behave differently from aggregates formed from a monodisperse population, having smaller drift velocities with directions which deviate substantially from the direction of illumination. Results agree with microgravity experiments which show the difference of photophoretic forces with aggregation state.

  18. 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…

  19. 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…

  20. 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.

  1. Individual Preferences and Social Interactions Determine the Aggregation of Woodlice

    PubMed Central

    Devigne, Cédric; Broly, Pierre; Deneubourg, Jean-Louis

    2011-01-01

    Background The aggregation of woodlice in dark and moist places is considered an adaptation to land life and most studies are focused on its functionality or on the behavioural mechanisms related to the individual's response to abiotic factors. Until now, no clear experimental demonstration was available about aggregation resulting from inter-attraction between conspecifics. Methodology/Main Findings We present the dynamics of aggregation, not previously described in detail in literature, as being independent of the experimental conditions: homogeneous and heterogeneous environments with identical or different shelters. Indeed whatever these conditions, the aggregation is very quick. In less than 10 minutes more than 50% of woodlice were aggregated in several small groups in the homogeneous environment or under shelters in the heterogeneous environment. After this fast aggregation, woodlice progressively moved into a single aggregate or under one shelter. Conclusions/Significance Here we show for the first time that aggregation in woodlice implies a strong social component and results from a trade-off between individual preferences and inter-attraction between individuals. Moreover, our results reveal that the response to the heterogeneities affects only the location of the aggregates and not the level of aggregation, and demonstrate the strong inter-attraction between conspecifics which can outweigh individual preferences. This inter-attraction can lead to situations that could seem sub-optimal. PMID:21364761

  2. 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 ...

  3. Aggregation behaviour of biohybrid microgels from elastin-like recombinamers.

    PubMed

    Singh, Smriti; Demco, Dan Eugen; Rahimi, Khosrow; Fechete, Radu; Rodriguez-Cabello, José Carlos; Möller, Martin

    2016-07-20

    Investigation of the aggregation behavior of biohybrid microgels, which can potentially be used as drug carriers, is an important topic, because aggregation not only causes loss of activity, but also toxicity and immunogenicity. To study this effect we synthesized microgels from elastin-like recombinamers (ELRs) using the miniemulsion technique. The existence of aggregation for such biohybrid microgels at different concentrations and temperatures was studied by different methods which include dynamic light scattering (DLS), (1)H high-resolution magic angle sample spinning (HRMAS) NMR spectroscopy, relaxometry and diffusometry. A hysteresis effect was detected in the process of aggregation by DLS as a function of temperature that strongly depends on ELR microgel concentration. The aggregation process was further quantitatively analyzed by the concentration dependence of the (1)H amino-acid residue chemical shifts and microgel diffusivity measured by NMR methods using the population balance kinetic aggregation model. PMID:27378252

  4. 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.

  5. 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.

  6. Protein aggregates in Huntington's disease.

    PubMed

    Arrasate, Montserrat; Finkbeiner, Steven

    2012-11-01

    Huntington's disease (HD) is an incurable neurodegenerative disease characterized by abnormal motor movements, personality changes, and early death. HD is caused by a mutation in the IT-15 gene that expands abnormally the number of CAG nucleotide repeats. As a result, the translated protein huntingtin contains disease-causing expansions of glutamines (polyQ) that make it prone to misfold and aggregate. While the gene and mutations that cause HD are known, the mechanisms underlying HD pathogenesis are not. Here we will review the state of knowledge of HD, focusing especially on a hallmark pathological feature-intracellular aggregates of mutant Htt called inclusion bodies (IBs). We will describe the role of IBs in the disease. We speculate that IB formation could be just one component of a broader coping response triggered by misfolded Htt whose efficacy may depend on the extent to which it clears toxic forms of mutant Htt. We will describe how IB formation might be regulated and which factors could determine different coping responses in different subsets of neurons. A differential regulation of IB formation as a function of the cellular context could, eventually, explain part of the neuronal vulnerability observed in HD. PMID:22200539

  7. Attracted diffusion-limited aggregation.

    PubMed

    Rahbari, S H Ebrahimnazhad; Saberi, A A

    2012-07-01

    In this paper we present results of extensive Monte Carlo simulations of diffusion-limited aggregation (DLA) with a seed placed on an attractive plane as a simple model in connection with the electrical double layers. We compute the fractal dimension of the aggregated patterns as a function of the attraction strength α. For the patterns grown in both two and three dimensions, the fractal dimension shows a significant dependence on the attraction strength for small values of α and approaches that of the ordinary two-dimensional (2D) DLA in the limit of large α. For the nonattracting case with α = 1, our results in three dimensions reproduce the patterns of 3D ordinary DLA, while in two dimensions our model leads to the formation of a compact cluster with dimension 2. For intermediate α, the 3D clusters have a quasi-2D structure with a fractal dimension very close to that of the ordinary 2D DLA. This allows one to control the morphology of a growing cluster by tuning a single external parameter α. PMID:23005417

  8. Attracted diffusion-limited aggregation

    NASA Astrophysics Data System (ADS)

    Rahbari, S. H. Ebrahimnazhad; Saberi, A. A.

    2012-07-01

    In this paper we present results of extensive Monte Carlo simulations of diffusion-limited aggregation (DLA) with a seed placed on an attractive plane as a simple model in connection with the electrical double layers. We compute the fractal dimension of the aggregated patterns as a function of the attraction strength α. For the patterns grown in both two and three dimensions, the fractal dimension shows a significant dependence on the attraction strength for small values of α and approaches that of the ordinary two-dimensional (2D) DLA in the limit of large α. For the nonattracting case with α=1, our results in three dimensions reproduce the patterns of 3D ordinary DLA, while in two dimensions our model leads to the formation of a compact cluster with dimension 2. For intermediate α, the 3D clusters have a quasi-2D structure with a fractal dimension very close to that of the ordinary 2D DLA. This allows one to control the morphology of a growing cluster by tuning a single external parameter α.

  9. Increased cytoplasm viscosity hampers aggregate polar segregation in Escherichia coli.

    PubMed

    Oliveira, Samuel M D; Neeli-Venkata, Ramakanth; Goncalves, Nadia S M; Santinha, João A; Martins, Leonardo; Tran, Huy; Mäkelä, Jarno; Gupta, Abhishekh; Barandas, Marilia; Häkkinen, Antti; Lloyd-Price, Jason; Fonseca, José M; Ribeiro, Andre S

    2016-02-01

    In Escherichia coli, under optimal conditions, protein aggregates associated with cellular aging are excluded from midcell by the nucleoid. We study the functionality of this process under sub-optimal temperatures from population and time lapse images of individual cells and aggregates and nucleoids within. We show that, as temperature decreases, aggregates become homogeneously distributed and uncorrelated with nucleoid size and location. We present evidence that this is due to increased cytoplasm viscosity, which weakens the anisotropy in aggregate displacements at the nucleoid borders that is responsible for their preference for polar localisation. Next, we show that in plasmolysed cells, which have increased cytoplasm viscosity, aggregates are also not preferentially located at the poles. Finally, we show that the inability of cells with increased viscosity to exclude aggregates from midcell results in enhanced aggregate concentration in between the nucleoids in cells close to dividing. This weakens the asymmetries in aggregate numbers between sister cells of subsequent generations required for rejuvenating cell lineages. We conclude that the process of exclusion of protein aggregates from midcell is not immune to stress conditions affecting the cytoplasm viscosity. The findings contribute to our understanding of E. coli's internal organisation and functioning, and its fragility to stressful conditions. PMID:26507787

  10. 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. PMID:20434898

  11. Mechanisms and Rates of Bacterial Colonization of Sinking Aggregates

    PubMed Central

    Kiørboe, Thomas; Grossart, Hans-Peter; Ploug, Helle; Tang, Kam

    2002-01-01

    Quantifying the rate at which bacteria colonize aggregates is a key to understanding microbial turnover of aggregates. We used encounter models based on random walk and advection-diffusion considerations to predict colonization rates from the bacteria's motility patterns (swimming speed, tumbling frequency, and turn angles) and the hydrodynamic environment (stationary versus sinking aggregates). We then experimentally tested the models with 10 strains of bacteria isolated from marine particles: two strains were nonmotile; the rest were swimming at 20 to 60 μm s−1 with different tumbling frequency (0 to 2 s−1). The rates at which these bacteria colonized artificial aggregates (stationary and sinking) largely agreed with model predictions. We report several findings. (i) Motile bacteria rapidly colonize aggregates, whereas nonmotile bacteria do not. (ii) Flow enhances colonization rates. (iii) Tumbling strains colonize aggregates enriched with organic substrates faster than unenriched aggregates, while a nontumbling strain did not. (iv) Once on the aggregates, the bacteria may detach and typical residence time is about 3 h. Thus, there is a rapid exchange between attached and free bacteria. (v) With the motility patterns observed, freely swimming bacteria will encounter an aggregate in <1 day at typical upper-ocean aggregate concentrations. This is faster than even starving bacteria burn up their reserves, and bacteria may therefore rely solely on aggregates for food. (vi) The net result of colonization and detachment leads to a predicted equilibrium abundance of attached bacteria as a function of aggregate size, which is markedly different from field observations. This discrepancy suggests that inter- and intraspecific interactions among bacteria and between bacteria and their predators may be more important than colonization in governing the population dynamics of bacteria on natural aggregates. PMID:12147501

  12. 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.

  13. 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

  14. 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. PMID:26644557

  15. Cosmogenic nuclide production rates as a function of latitude and altitude calculated via a physics based model and excitation functions

    NASA Astrophysics Data System (ADS)

    Argento, D.; Reedy, R. C.; Stone, J. O.

    2012-12-01

    Cosmogenic nuclides have been used to develop a set of tools critical to the quantification of a wide range of geomorphic and climatic processes and events (Dunai 2010). Having reliable absolute measurement methods has had great impact on research constraining ice age extents as well as providing important climatic data via well constrained erosion rates, etc. Continuing to improve CN methods is critical for these sciences. While significant progress has been made in the last two decades to reduce uncertainties (Dunai 2010; Gosse & Phillips 2001), numerous aspects still need to be refined in order to achieve the analytic resolution desired by glaciologists and geomorphologists. In order to investigate the finer details of the radiation responsible for cosmogenic nuclide production, we have developed a physics based model which models the radiation cascade of primary and secondary cosmic-rays through the atmosphere. In this study, a Monte Carlo method radiation transport code, MCNPX, is used to model the galactic cosmic-ray (GCR) radiation impinging on the upper atmosphere. Beginning with a spectrum of high energy protons and alpha particles at the top of the atmosphere, the code tracks the primary and resulting secondary particles through a model of the Earth's atmosphere and into the lithosphere. Folding the neutron and proton flux results with energy dependent cross sections for nuclide production provides production rates for key cosmogenic nuclides (Argento et al. 2012, in press; Reedy 2012, in press). Our initial study for high latitude shows that nuclides scale at different rates for each nuclide (Argento 2012, in press). Furthermore, the attenuation length for each of these nuclide production rates increases with altitude, and again, they increase at different rates. This has the consequence of changing the production rate ratio as a function of altitude. The earth's geomagnetic field differentially filters low energy cosmic-rays by deflecting them away

  16. Lanosterol reverses protein aggregation in cataracts.

    PubMed

    Zhao, Ling; Chen, Xiang-Jun; Zhu, Jie; Xi, Yi-Bo; Yang, Xu; Hu, Li-Dan; Ouyang, Hong; Patel, Sherrina H; Jin, Xin; Lin, Danni; Wu, Frances; Flagg, Ken; Cai, Huimin; Li, Gen; Cao, Guiqun; Lin, Ying; Chen, Daniel; Wen, Cindy; Chung, Christopher; Wang, Yandong; Qiu, Austin; Yeh, Emily; Wang, Wenqiu; Hu, Xun; Grob, Seanna; Abagyan, Ruben; Su, Zhiguang; Tjondro, Harry Christianto; Zhao, Xi-Juan; Luo, Hongrong; Hou, Rui; Perry, J Jefferson P; Gao, Weiwei; Kozak, Igor; Granet, David; Li, Yingrui; Sun, Xiaodong; Wang, Jun; Zhang, Liangfang; Liu, Yizhi; Yan, Yong-Bin; Zhang, Kang

    2015-07-30

    The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment. PMID:26200341

  17. New Software Product Feature Identification: An Analysis of E-mail User Characteristics and Functional Requirements

    NASA Astrophysics Data System (ADS)

    Sofuoglu, Ecehan; Basoglu, Nuri; Daim, Tugrul

    Improving the product development process is becoming more important as business environment gets more competitive. This study aims at understanding and characterizing potential users of a software product through idea sharing of users. It also targets to create a new product concept through understanding the common features users prefer most. During this product conceptualization stage, the customer ideas are captured through use of a questionnaire. The target users, priority of product functions and features are investigated and the details of the existing e-mail systems as well as of the ideal e-mail systems are identified. Some of the key results included users with demographic differences having different usage and requirements characteristics, expectations of females being higher than those of males and the software functions used and characteristics required being different for those with different job categories or educational backgrounds.

  18. Dynamics of fire ant aggregations

    NASA Astrophysics Data System (ADS)

    Tennenbaum, Michael; Hu, David; Fernandez-Nieves, Alberto

    Fire ant aggregations are an inherently active system. Each ant harvests its own energy and can convert it into motion. The motion of individual ants contributes non-trivially to the bulk material properties of the aggregation. We have measured some of these properties using plate-plate rheology, where the response to an applied external force or deformation is measured. In this talk, we will present data pertaining to the aggregation behavior in the absence of any external force. We quantify the aggregation dynamics by monitoring the rotation of the top plate and by measuring the normal force. We then compare the results with visualizations of 2D aggregations.

  19. 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.

  20. Entrapment of Aβ1-40 peptide in unstructured aggregates

    NASA Astrophysics Data System (ADS)

    Corsale, C.; Carrotta, R.; Mangione, M. R.; Vilasi, S.; Provenzano, A.; Cavallaro, G.; Bulone, D.; San Biagio, P. L.

    2012-06-01

    Recognizing the complexity of the fibrillogenesis process provides a solid ground for the development of therapeutic strategies aimed at preventing or inhibiting protein-protein aggregation. Under this perspective, it is meaningful to identify the possible aggregation pathways and their relative products. We found that Aβ-peptide dissolved in a pH 7.4 solution at small peptide concentration and low ionic strength forms globular aggregates without typical amyloid β-conformation. ThT binding kinetics was used to monitor aggregate formation. Circular dichroism spectroscopy, AFM imaging, static and dynamic light scattering were used for structural and morphological characterization of the aggregates. They appear stable or at least metastable with respect to fiber growth, therefore appearing as an incidental product in the pathway of fibrillogenesis.

  1. Inner products of Bethe states as partial domain wall partition functions

    NASA Astrophysics Data System (ADS)

    Kostov, Ivan; Matsuo, Yutaka

    2012-10-01

    We study the inner product of Bethe states in the inhomogeneous periodic XXX spin-1/2 chain of length L, which is given by the Slavnov determinant formula. We show that the inner product of an on-shell M -magnon state with a generic M -magnon state is given by the same expression as the inner product of a 2 M -magnon state with a vacuum descendent. The second inner product is proportional to the partition function of the six-vertex model on a rectangular L × 2 M grid, with partial domain-wall boundary conditions.

  2. 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.

  3. Sampling epifauna, a necessity for a better assessment of benthic ecosystem functioning: an example of the epibenthic aggregated species Ophiothrix fragilis from the Bay of Seine.

    PubMed

    Lozach, Sophie; Dauvin, Jean-Claude; Méar, Yann; Murat, Anne; Davoult, Dominique; Migné, Aline

    2011-12-01

    Sampling the sea bottom surface remains difficult because of the surface hydraulic shock due to water flowing through the gear (i.e., the bow wave effect) and the loss of epifauna organisms due to the gear's closing mechanism. Slow-moving mobile epifauna, such as the ophiuroid Ophiothrix fragilis, form high-density patches in the English Channel, not only on pebbles like in the Dover Strait or offshore Brittany but also on gravel in the Bay of Seine (>5000 ind m(-2)). Such populations form high biomasses and control the water transfer from the water column to the sediment. Estimating their real density and biomass is essential for the assessment of benthic ecosystem functioning using trophic web modelling. In this paper, we present and discuss the patch patterns and sampling efficiency of the different methods for collecting in the dense beds of O. fragilis in the Bay of Seine. The large Hamon grab (0.25 m(-2)) highly under-estimated the ophiuroid density, while the Smith McIntyre appeared adequate among the tested sampling grabs. Nowadays, diving sampling, underwater photography and videos with remote operated vehicle appear to be the recommended alternatives to estimate the real density of such dense slow-moving mobile epifauna. PMID:21967863

  4. 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. PMID:26437913

  5. Selective molecular sequestration with concurrent natural product functionalization and derivatization: from crude natural product extracts to a single natural product derivative in one step.

    PubMed

    Krchňák, Viktor; Zajíček, Jaroslav; Miller, Patricia A; Miller, Marvin J

    2011-12-16

    A resin-bound nitroso compound sequestered a single unexpected component from crude plant seed extracts. Several plants, including Piper nigrum, Eugenia caryophyllata, and Pimenta dioica, were extracted with organic solvent in the presence of a nitroso-containing resin. The nitroso resin selectively sequestered a single compound, β-caryophyllene, via a chemo- and regioselective ene reaction. The ene product was released from the resin, and proper selection of the solid-phase linker and cleavage cocktail allowed concomitant further transformation of the primary ene product to a novel functionalized polycycle. Preliminary studies indicate that the new hydroxylamine-containing natural product derivatives have antibiotic activity. PMID:22059469

  6. Selective Molecular Sequestration with Concurrent Natural Product Functionalization and Derivatization: From Crude Natural Product Extracts to a Single Natural Product Derivative in One Step

    PubMed Central

    Krchňák, Viktor; Zajíček, Jaroslav; Miller, Patricia A.; Miller, Marvin J.

    2011-01-01

    A resin-bound nitroso compound sequestered a single unexpected component from crude plant seed extracts. Several plants, including Piper nigrum, Eugenia caryophyllata, and Pimenta dioica, were extracted with organic solvent in the presence of a nitroso-containing resin. The nitroso resin selectively sequestered a single compound, β-caryophyllene, via a chemo and regioselective ene reaction. The ene product was released from the resin and proper selection of the solid-phase linker and cleavage cocktail allowed concomitant further transformation of the primary ene product to a novel functionalized polycycle. Preliminary studies indicate that the new hydroxylamine-containing natural product derivatives have antibiotic activity. PMID:22059469

  7. 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.

  8. 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

  9. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography.

    PubMed

    Darrow, Michele C; Sergeeva, Oksana A; Isas, Jose M; Galaz-Montoya, Jesús G; King, Jonathan A; Langen, Ralf; Schmid, Michael F; Chiu, Wah

    2015-07-10

    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

  10. Protein A chromatography increases monoclonal antibody aggregation rate during subsequent low pH virus inactivation hold

    PubMed Central

    Mazzer, Alice R.; Perraud, Xavier; Halley, Jennifer; O’Hara, John; Bracewell, Daniel G.

    2015-01-01

    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. PMID:26346187

  11. 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.

  12. Morphological classification of nanoceramic aggregates

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni F.; Kang, Bongwoo; Ospina, Carolina; Sung, Changmo

    2005-01-01

    Aluminum silicate nanoaggregates grown at near-room temperature on an organic template under a variety of experimental conditions have been imaged by transmission electron microscopy. Images have been automatically classified by an algorithm based on "spectrum enhancement", multivariate statistics and supervised optimization. Spectrum enhancement consists of subtracting, in the log scale, a known function of wavenumber from the angle averaged power spectral density of the image. Enhanced spectra of each image, after polynomial interpolation, have been regarded as morphological descriptors and as such submitted to principal components analysis nested with a multiobjective parameter optimization algorithm. The latter has maximized pairwise discrimination between classes of materials. The role of the organic template and of a reaction parameter on aggregate morphology has been assessed at two magnification scales. Classification results have also been related to crystal structure data derived from selected area electron diffraction patterns.

  13. 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

  14. Certain Fractional Integral Formulas Involving the Product of Generalized Bessel Functions

    PubMed Central

    Baleanu, D.; Agarwal, P.; Purohit, S. D.

    2013-01-01

    We apply generalized operators of fractional integration involving Appell's function F3(·) 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. PMID:24379745

  15. 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.

  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. PMID:18582508

  17. 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. PMID:25748244

  18. 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

  19. 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.

  20. Tracking Hypoxic Signaling within Encapsulated Cell Aggregates

    PubMed Central

    Skiles, Matthew L.; Sahai, Suchit; Blanchette, James O.

    2011-01-01

    In Diabetes mellitus type 1, autoimmune destruction of the pancreatic β-cells results in loss of insulin production and potentially lethal hyperglycemia. As an alternative treatment option to exogenous insulin injection, transplantation of functional pancreatic tissue has been explored1,2. This approach offers the promise of a more natural, long-term restoration of normoglycemia. Protection of the donor tissue from the host's immune system is required to prevent rejection and encapsulation is a method used to help achieve this aim. Biologically-derived materials, such as alginate3 and agarose4, have been the traditional choice for capsule construction but may induce inflammation or fibrotic overgrowth5 which can impede nutrient and oxygen transport. Alternatively, synthetic poly(ethylene glycol) (PEG)-based hydrogels are non-degrading, easily functionalized, available at high purity, have controllable pore size, and are extremely biocompatible,6,7,8. As an additional benefit, PEG hydrogels may be formed rapidly in a simple photo-crosslinking reaction that does not require application of non-physiological temperatures6,7. Such a procedure is described here. In the crosslinking reaction, UV degradation of the photoinitiator, 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (Irgacure 2959), produces free radicals which attack the vinyl carbon-carbon double bonds of dimethacrylated PEG (PEGDM) inducing crosslinking at the chain ends. Crosslinking can be achieved within 10 minutes. PEG hydrogels constructed in such a manner have been shown to favorably support cells7,9, and the low photoinitiator concentration and brief exposure to UV irradiation is not detrimental to viability and function of the encapsulated tissue10. While we methacrylate our PEG with the method described below, PEGDM can also be directly purchased from vendors such as Sigma. An inherent consequence of encapsulation is isolation of the cells from a vascular network. Supply of

  1. Tracking hypoxic signaling within encapsulated cell aggregates.

    PubMed

    Skiles, Matthew L; Sahai, Suchit; Blanchette, James O

    2011-01-01

    In Diabetes mellitus type 1, autoimmune destruction of the pancreatic β-cells results in loss of insulin production and potentially lethal hyperglycemia. As an alternative treatment option to exogenous insulin injection, transplantation of functional pancreatic tissue has been explored. This approach offers the promise of a more natural, long-term restoration of normoglycemia. Protection of the donor tissue from the host's immune system is required to prevent rejection and encapsulation is a method used to help achieve this aim. Biologically-derived materials, such as alginate and agarose, have been the traditional choice for capsule construction but may induce inflammation or fibrotic overgrowth which can impede nutrient and oxygen transport. Alternatively, synthetic poly(ethylene glycol) (PEG)-based hydrogels are non-degrading, easily functionalized, available at high purity, have controllable pore size, and are extremely biocompatible. As an additional benefit, PEG hydrogels may be formed rapidly in a simple photo-crosslinking reaction that does not require application of non-physiological temperatures. Such a procedure is described here. In the crosslinking reaction, UV degradation of the photoinitiator, 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (Irgacure 2959), produces free radicals which attack the vinyl carbon-carbon double bonds of dimethacrylated PEG (PEGDM) inducing crosslinking at the chain ends. Crosslinking can be achieved within 10 minutes. PEG hydrogels constructed in such a manner have been shown to favorably support cells, and the low photoinitiator concentration and brief exposure to UV irradiation is not detrimental to viability and function of the encapsulated tissue. While we methacrylate our PEG with the method described below, PEGDM can also be directly purchased from vendors such as Sigma. An inherent consequence of encapsulation is isolation of the cells from a vascular network. Supply of nutrients, notably oxygen

  2. Asphaltene Aggregation and Fouling Behavior

    NASA Astrophysics Data System (ADS)

    Derakhshesh, Marzie

    . Analysis of the spectra of the whole asphaltene samples in toluene indicates that the absorbance of visible light with wavelengths > 600 nm follows a lambda--4 dependence. This functional dependence is consistent with Rayleigh scattering. Rayleigh scattering provides strong evidence that the apparent absorption of visible light by asphaltenes from 600-800 nm is not a molecular absorption phenomenon but rather a scattering mechanism. Rayleigh scattering equations were combined with experimental visible spectra to estimate the average nanoaggregate sizes, which were in a very good agreement with the sizes reported in the literature. The occlusion of two polynuclear aromatic hydrocarbons (PAHs) (pyrene and phenanthrene) in asphaltene precipitates was tested by adding PAHs to the asphaltene in toluene solutions, precipitating by n-pentane and determining the amount of PAHs in precipitates using simulated distillation instrument. Pyrene and phenanthrene, which are normally soluble in the toluene-n-pentane solutions, were detected in the asphaltene precipitates at up to 6 wt% concentration. Trapping of PAHs outside of the nanoaggregates during precipitation gave 7-14 times less of the PAHs in the solid precipitate. This study shows that asphaltene aggregates can interact significantly with PAHs. The results are consistent with the presence open porous asphaltene nanoaggregates in solutions such as toluene.

  3. 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. PMID:27498012

  4. 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. PMID:26325019

  5. Variable Effects of Dispersal on Productivity of Bacterial Communities Due to Changes in Functional Trait Composition

    PubMed Central

    Severin, Ina; Östman, Örjan; Lindström, Eva S.

    2013-01-01

    Previous studies have shown variable relationships between dispersal rate and ecosystem functioning, but the reasons for and mechanisms behind variable dispersal rate – functioning patterns are currently unknown. In this study we used six bacterial lake water communities in a laboratory experiment in order to investigate how dispersal among communities influences community productivity by evaluating three different mechanisms: 1) changes in taxonomic diversity, 2) changes in phylogenetic diversity or 3) changes in the composition of functional traits. The experiment was conducted in two phases; (A) a dialysis bag experiment where the dispersal rate among six communities was manipulated and the subsequent change in bacterial diversity and growth rate was recorded, and (B) a regrowth experiment where we manipulated available resources to study how well a taxon grows on certain organic carbon resources, i.e. their functional traits. From experiment (B) we could thus estimate changes in functional traits in communities in experiment (A). Bacterial production was affected by dispersal, but not consistently among lakes. Neither change in taxonomic or phylogenetic diversity with dispersal could explain the observed dispersal – productivity relationships. Instead, changes in trait composition with dispersal, especially the communities’ ability to use p-coumaric acid, an aromatic compound, could explain the observed dispersal – productivity relationships. Changes in this trait caused by dispersal seemed especially important for bacterial productivity in waters with a high aromaticity of the organic matter pool. We conclude that the effect of dispersal on bacterial communities can affect ecosystem functioning in different ways, through changes in functional key-traits which are important for the local environment. PMID:24324633

  6. Variable effects of dispersal on productivity of bacterial communities due to changes in functional trait composition.

    PubMed

    Severin, Ina; Östman, Örjan; Lindström, Eva S

    2013-01-01

    Previous studies have shown variable relationships between dispersal rate and ecosystem functioning, but the reasons for and mechanisms behind variable dispersal rate-functioning patterns are currently unknown. In this study we used six bacterial lake water communities in a laboratory experiment in order to investigate how dispersal among communities influences community productivity by evaluating three different mechanisms: 1) changes in taxonomic diversity, 2) changes in phylogenetic diversity or 3) changes in the composition of functional traits. The experiment was conducted in two phases; (A) a dialysis bag experiment where the dispersal rate among six communities was manipulated and the subsequent change in bacterial diversity and growth rate was recorded, and (B) a regrowth experiment where we manipulated available resources to study how well a taxon grows on certain organic carbon resources, i.e. their functional traits. From experiment (B) we could thus estimate changes in functional traits in communities in experiment (A). Bacterial production was affected by dispersal, but not consistently among lakes. Neither change in taxonomic or phylogenetic diversity with dispersal could explain the observed dispersal-productivity relationships. Instead, changes in trait composition with dispersal, especially the communities' ability to use p-coumaric acid, an aromatic compound, could explain the observed dispersal-productivity relationships. Changes in this trait caused by dispersal seemed especially important for bacterial productivity in waters with a high aromaticity of the organic matter pool. We conclude that the effect of dispersal on bacterial communities can affect ecosystem functioning in different ways, through changes in functional key-traits which are important for the local environment. PMID:24324633

  7. Taurine and platelet aggregation

    SciTech Connect

    Nauss-Karol, C.; VanderWende, C.; Gaut, Z.N.

    1986-03-01

    Taurine is a putative neurotransmitter or neuromodulator. The endogenous taurine concentration in human platelets, determined by amino acid analysis, is 15 ..mu..M/g. In spite of this high level, taurine is actively accumulated. Uptake is saturable, Na/sup +/ and temperature dependent, and suppressed by metabolic inhibitors, structural analogues, and several classes of centrally active substances. High, medium and low affinity transport processes have been characterized, and the platelet may represent a model system for taurine transport in the CNS. When platelets were incubated with /sup 14/C-taurine for 30 minutes, then resuspended in fresh medium and reincubated for one hour, essentially all of the taurine was retained within the cells. Taurine, at concentrations ranging from 10-1000 ..mu..M, had no effect on platelet aggregation induced by ADP or epinephrine. However, taurine may have a role in platelet aggregation since 35-39% of the taurine taken up by human platelets appears to be secreted during the release reaction induced by low concentrations of either epinephrine or ADP, respectively. This release phenomenon would imply that part of the taurine taken up is stored directly in the dense bodies of the platelet.

  8. Toward a common aggregation mechanism for a β-barrel protein family: insights derived from a stable dimeric species.

    PubMed

    Angelani, Carla R; Curto, Lucrecia M; Cabanas, Inés S; Caramelo, Julio J; Uversky, Vladimir N; Delfino, José M

    2014-09-01

    Δ78Δ is a second generation functional all-β sheet variant of IFABP (intestinal fatty acid binding protein) corresponding to the fragment 29-106 of the parent protein. This protein and its predecessor, Δ98Δ (segment 29-126 of IFABP), were initially uncovered by controlled proteolysis. Remarkably, although IFABP and Δ98Δ are monomers in solution, Δ78Δ adopts a stable dimeric structure. With the aim of identifying key structural features that modulate the aggregation of β-proteins, we evaluate here the structure and aggregation propensity of Δ78Δ. The 2,2,2-trifluoroethanol (TFE) induced aggregation of this protein shows a primary nucleation-elongation mechanism, characterized by the stabilization of a dimeric nucleus. Its rate of production from the co-solvent induced aggregation prone state governs the kinetics of polymerization. In this context, the value of Δ78Δ lies in the fact that - being a stable dimeric species - it reduces an otherwise bimolecular reaction to a unimolecular one. Interestingly, even though Δ78Δ and IFABP display similar conformational stability, the abrogated form of IFABP shows an enhanced aggregation rate, revealing the ancillary role played on this process by the free energy of the native proteins. Δ78Δ share with IFABP and Δ98Δ a common putative aggregation-prone central peptide. Differences in the exposure/accessibility of this segment dictated by the environment around this region might underlie the observed variations in the speed of aggregation. Lessons learnt from this natural dimeric protein might shed light on the early conformational events leading to β-conversion from barrels to amyloid aggregates. PMID:24929115

  9. IL-27 supports germinal center function by enhancing IL-21 production and the function of T follicular helper cells.

    PubMed

    Batten, Marcel; Ramamoorthi, Nandhini; Kljavin, Noelyn M; Ma, Cindy S; Cox, Jennifer H; Dengler, Hart S; Danilenko, Dimitry M; Caplazi, Patrick; Wong, Melanie; Fulcher, David A; Cook, Matthew C; King, Cecile; Tangye, Stuart G; de Sauvage, Frederic J; Ghilardi, Nico

    2010-12-20

    Maturation and selection of high-affinity B cell clones in the germinal center (GC) relies on support from T follicular helper (T(FH)) cells. T(FH) cells are characterized by their localization to the B cell follicle and their high expression of the costimulatory molecules ICOS and PD1 and the cytokine IL-21, which promotes immunoglobulin (Ig) class switching and production by B cells. We show that the heterodimeric cytokine IL-27 is critical for the function of T(FH) cells and for normal and pathogenic GC responses. IL-27 signaling to T cells results in the production of IL-21, a known autocrine factor for the maintenance of T(FH) cells, in a STAT3-dependent manner. IL-27 also enhances the survival of activated CD4(+) T cells and the expression of T(FH) cell phenotypic markers. In vivo, expression of the IL-27Rα chain is required to support IL-21 production and T(FH) cell survival in a T cell-intrinsic manner. The production of high-affinity antibodies is reduced, and pristane-elicited autoantibodies and glomerulonephritis are significantly diminished, in Il27ra(-/-) mice. Together, our data show a nonredundant role for IL-27 in the development of T cell-dependent antibody responses. PMID:21098093

  10. 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.

  11. 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.

  12. Combination of microwell structures and direct oxygenation enables efficient and size-regulated aggregate formation of an insulin-secreting pancreatic β-cell line.

    PubMed

    Shinohara, Marie; Kimura, Hiroshi; Montagne, Kevin; Komori, Kikuo; Fujii, Teruo; Sakai, Yasuyuki

    2014-01-01

    Spherical three-dimensional (3D) cellular aggregates are valuable for various applications such as regenerative medicine or cell-based assays due to their stable and high functionality. However, previous methods to form aggregates have shown drawbacks, being labor-intensive, showing low productivity per unit area or volume and difficulty to form homogeneous aggregates. We proposed a novel strategy based on oxygen-permeable polydimethylsiloxane (PDMS) honeycomb microwell sheets, which can theoretically supply about 80 times as much oxygen as conventional polystyrene culture dishes, to produce recoverable aggregates in controllable sizes using mouse insulinoma cells (MIN6-m9). In 48 hours of culture, the PDMS sheets produced aggregates whose diameters were strictly controlled (≃32, 60, 90, 150 and 280 mm) even at an inoculum density eight times higher (8.0×105 cells/cm(2) ) than that of normal confluent monolayers (1.0×105 cells/cm(2) ). Measurement of the oxygen tension near the cell layer and glucose/lactate analysis clearly showed that cells exhibit aerobic respiration on the PDMS-based culture system. Glucose-responsive insulin secretion of the recovered aggregates showed that the aggregates around 90 mm in diameter secreted the largest amounts of insulin. This confirmed the advantages of 3D cellular organization and the existence of a suitable aggregate size, above which excess organization leads to a decreased metabolic response. These results demonstrated that this microwell-based PDMS culture system provides a promising method to form size-regulated and better functioning 3D cellular aggregates of various kinds of cells with a high yield per surface area. PMID:24265060

  13. 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.

  14. 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). PMID:24679256

  15. 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

  16. 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.

  17. 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.

  18. Helicobacter pylori TlyA Forms Amyloid-like Aggregates with Potent Cytotoxic Activity.

    PubMed

    Lata, Kusum; Chattopadhyay, Kausik

    2015-06-16

    Helicobacter pylori is a potent human gastric pathogen. It is known to be associated with several gastroenteric disorders, including gastritis, peptic ulcer, and gastric cancer. The H. pylori genome encodes a gene product TlyA that has been shown to display potent membrane damaging properties and cytotoxic activity. On the basis of such properties, TlyA is considered as a potential virulence factor of H. pylori. In this study, we show that the H. pylori TlyA protein has a strong propensity to convert into the amyloid-like aggregated assemblies, upon exposure to elevated temperatures. Even at the physiological temperature of 37 °C, TlyA shows a strong amyloidogenic property. TlyA aggregates that are generated upon exposure at temperatures of ≥37 °C show prominent binding to dyes like thioflavin T and Nile Red. Transmission electron microscopy also demonstrates the presence of typical amyloid-like fibrils in the TlyA aggregates generated at 37 °C. Conversion of TlyA into the amyloid-like aggregates is found to be associated with major alterations in the secondary and tertiary structural organization of the protein. Finally, our study shows that the preformed amyloid-like aggregates of TlyA are capable of exhibiting potent cytotoxic activities against human gastric adenocarcinoma cells. Altogether, such a propensity of H. pylori TlyA to convert into the amyloid-like aggregated assemblies with cytotoxic activity suggests potential implications for the virulence functionality of the protein. PMID:26015064

  19. 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...

  20. Addendum: Factor Analysis of Explanatory Variables in an Achievement Production Function

    ERIC Educational Resources Information Center

    Phelps, James L.

    2011-01-01

    Combining explanatory variables into factors instead of using individual variables in an achievement production function is advocated in several of the articles in this special issue. This article provides a brief overview of factor analysis explaining and illustrating the reasoning for this technique. There is a linchpin: Factor analysis is an…

  1. 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. PMID:16954062

  2. 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, ...

  3. Functional significance of dinitrogen fixation in sustaining coral productivity under oligotrophic conditions.

    PubMed

    Cardini, Ulisse; Bednarz, Vanessa N; Naumann, Malik S; van Hoytema, Nanne; Rix, Laura; Foster, Rachel A; Al-Rshaidat, Mamoon M D; Wild, Christian

    2015-11-01

    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

  4. The Educational Production Function: Implications for Educational Manpower Policy. Institute of Public Employment Monograph No. 4.

    ERIC Educational Resources Information Center

    Heim, John; Perl, Lewis

    This monograph summarizes and evaluates "educational production function analyses"--studies of the relation between inputs and outputs in an education system--in order to aid in educational manpower policy making. In addition, data from New York state school districts and from a large national sample of high school students is subjected to…

  5. 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...

  6. Assessing Production and Ecosystem Function for Grain and Bioenergy Feedstock Crops Across Variable Soil Landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some soils in the U.S. Midwest region have been especially negatively impacted by grain cropping. The result has been lost productivity and diminished resiliency for ecosystem function. Of note are the degraded soils of the Midwest classed as “claypan soils.” These soils are disproportionate sources...

  7. 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.

  8. Implications of epidermal growth factor (EGF) induced egf receptor aggregation.

    PubMed Central

    Wofsy, C; Goldstein, B; Lund, K; Wiley, H S

    1992-01-01

    To investigate the role of receptor aggregation in EGF binding, we construct a mathematical model describing receptor dimerization (and higher levels of aggregation) that permits an analysis of the influence of receptor aggregation on ligand binding. We answer two questions: (a) Can Scatchard plots of EGF binding data be analyzed productively in terms of two noninteracting receptor populations with different affinities if EGF induced receptor aggregation occurs? No. If two affinities characterize aggregated and monomeric EGF receptors, we show that the Scatchard plot should have curvature characteristic of positively cooperative binding, the opposite of that observed. Thus, the interpretation that the high affinity population represents aggregated receptors and the low affinity population nonaggregated receptors is wrong. If the two populations are interpreted without reference to receptor aggregation, an important determinant of Scatchard plot shape is ignored. (b) Can a model for EGF receptor aggregation and EGF binding be consistent with the "negative curvature" (i.e., curvature characteristic of negatively cooperative binding) observed in most Scatchard plots of EGF binding data? Yes. In addition, the restrictions on the model parameters required to obtain negatively curved Scatchard plots provide new information about binding and aggregation. In particular, EGF binding to aggregated receptors must be negatively cooperative, i.e., binding to a receptor in a dimer (or higher oligomer) having one receptor already bound occurs with lower affinity than the initial binding event. A third question we consider is whether the model we present can be used to detect the presence of mechanisms other than receptor aggregation that are contributing to Scatchard plot curvature. For the membrane and cell binding data we analyzed, the best least squares fits of the model to each of the four data sets deviate systematically from the data, indicating that additional factors are

  9. 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. PMID:25952871

  10. 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.

  11. Proenkephalin products are stored in the sperm acrosome and may function in fertilization.

    PubMed Central

    Kew, D; Muffly, K E; Kilpatrick, D L

    1990-01-01

    Previous studies have shown that spermatogenic cells are a major source of testicular RNA encoding the opioid peptide precursor proenkephalin, suggesting that proenkephalin-derived peptides may function as intratesticular paracrine factors produced by male germ cells. However, direct evidence for the production of proenkephalin by spermatogenic cells has been lacking. In this report, we have used polysome profile analysis, peptide quantitation, and immunocytochemistry to show that proenkephalin products are synthesized during spermatogenesis and are retained within spermatozoa of humans, hamsters, rats, and sheep. We further show that these peptides are stored in the sperm acrosome and are depleted from sperm following the acrosome reaction, an exocytotic event required for fertilization. Proenkephalin products thus may serve a dual function as sperm acrosomal factors released during the fertilization process as well as intratesticular regulators secreted by spermatogenic cells. Images PMID:1701253

  12. Orthogonality, Lommel integrals and cross product zeros of linear combinations of Bessel functions.

    PubMed

    Ziener, Christian H; Kurz, Felix T; Buschle, Lukas R; Kampf, Thomas

    2015-01-01

    The cylindrical Bessel differential equation and the spherical Bessel differential equation in the interval [Formula: see text] with Neumann boundary conditions are considered. The eigenfunctions are linear combinations of the Bessel function [Formula: see text] or linear combinations of the spherical Bessel functions [Formula: see text]. The orthogonality relations with analytical expressions for the normalization constant are given. Explicit expressions for the Lommel integrals in terms of Lommel functions are derived. The cross product zeros [Formula: see text] and [Formula: see text] are considered in the complex plane for real as well as complex values of the index [Formula: see text] and approximations for the exceptional zero [Formula: see text] are obtained. A numerical scheme based on the discretization of the two-dimensional and three-dimensional Laplace operator with Neumann boundary conditions is presented. Explicit representations of the radial part of the Laplace operator in form of a tridiagonal matrix allow the simple computation of the cross product zeros. PMID:26251774

  13. Work productivity and neuropsychological function in persons with skull base tumors

    PubMed Central

    Nugent, Bethany D.; Weimer, Jason; Choi, Chienwen J.; Bradley, Cathy J.; Bender, Catherine M.; Ryan, Christopher M.; Gardner, Paul; Sherwood, Paula R.

    2014-01-01

    Background Skull base tumors comprise many common benign brain tumors. Treatment has advanced, allowing many survivors to return to work. However, literature is limited about the neuropsychological status of these patients prior to treatment. Literature pertaining to the relationship between neuropsychological functioning and occupational ability prior to surgical intervention is even more limited. The purpose of this analysis was to evaluate the impact of neuropsychological function on work productivity in persons with skull base tumors prior to resection. Methods Neuropsychological function and work productivity were assessed in adults newly diagnosed with skull base tumors (n = 45) prior to surgical intervention. Univariate analyses identified potential predictors of work limitations; variables with P < .10 were analyzed using multivariate regression analyses controlled for age, sex, tumor type, and education. Results Poorer mental attention and flexibility (MF) and higher depressive symptoms (DS) were significantly associated with poor time management at work (MF: β = -0.59, P = .01; DS: β = 3.42, P < .01; R2 = 0.54). Difficulty meeting physical work demands was significantly associated with poorer visuospatial ability (VA) and higher depressive symptoms (VA: β = −3.30, P = .05; DS: β = 2.29, P < .01; R2 = 0.29). Lower learning and memory scores (LM) and higher depressive symptoms were significantly associated with difficulty meeting mental-interpersonal work demands (LM: β = −3.39, P = .04; DS: β = 3.25, P < .01; R2 = 0.47) and overall health-related loss of work productivity (LM: β = −0.72, P = .05; DS: β = 0.659, P < .001; R2 = 0.43). Conclusion Domains of neuropsychological function that predicted work productivity were identified. Future research should examine neuropsychological function, depressive symptoms, and work productivity across the care trajectory from diagnosis through long-term survivorship. PMID:25789168

  14. A common functional neural network for overt production of speech and gesture.

    PubMed

    Marstaller, L; Burianová, H

    2015-01-22

    The perception of co-speech gestures, i.e., hand movements that co-occur with speech, has been investigated by several studies. The results show that the perception of co-speech gestures engages a core set of frontal, temporal, and parietal areas. However, no study has yet investigated the neural processes underlying the production of co-speech gestures. Specifically, it remains an open question whether Broca's area is central to the coordination of speech and gestures as has been suggested previously. The objective of this study was to use functional magnetic resonance imaging to (i) investigate the regional activations underlying overt production of speech, gestures, and co-speech gestures, and (ii) examine functional connectivity with Broca's area. We hypothesized that co-speech gesture production would activate frontal, temporal, and parietal regions that are similar to areas previously found during co-speech gesture perception and that both speech and gesture as well as co-speech gesture production would engage a neural network connected to Broca's area. Whole-brain analysis confirmed our hypothesis and showed that co-speech gesturing did engage brain areas that form part of networks known to subserve language and gesture. Functional connectivity analysis further revealed a functional network connected to Broca's area that is common to speech, gesture, and co-speech gesture production. This network consists of brain areas that play essential roles in motor control, suggesting that the coordination of speech and gesture is mediated by a shared motor control network. Our findings thus lend support to the idea that speech can influence co-speech gesture production on a motoric level. PMID:25290017

  15. Ingredient Functionality in Multilayered Dough-margarine Systems and the Resultant Pastry Products: A Review.

    PubMed

    Ooms, Nand; Pareyt, Bram; Brijs, Kristof; Delcour, Jan A

    2016-10-01

    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. PMID:26177127

  16. 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

  17. Autophagy, Protein Aggregation and Hyperthermia: A Minireview

    PubMed Central

    Zhang, Yue; Calderwood, Stuart K

    2014-01-01

    Purpose We aim to explore the role of macroautophagy in cellular responses to hyperthermia. Protein damage incurred during hyperthermia can either lead to cell death or may be repaired by polypeptide quality control pathways including: (1) the deterrence of protein unfolding by molecular chaperones and (2) proteolysis of the denatured proteins within the proteasome. A third pathway of protein quality control is triggered by formation of protein aggregates in the heat shocked cell. This is the macroautophagy pathway in which protein aggregates are transported to specialized organelles called autolysosomes capable of degrading the aggregates. The consequences for cell viability of triggering this pathway are complex and may involve cell death, although under many circumstances, including exposure of cells to hyperthermia, autophagy leads to enhanced cell survival. We have discussed mechanisms by which cells detect protein aggregates and recruit them into the macroautophagy pathway as well as the potential role of inhibiting this process in hyperthermia. Conclusions Directed macroautophagy, with its key role in protein quality control, seems an attractive target for a therapy such as hyperthermia that functions principally through denaturing the proteome. However, much work is needed to decode the mechanisms of thermal stress-mediated macroautophagy and their role in survival / death of cancer cells before recommendations can be made on targeting this pathway in combination with hyperthermia. PMID:21756038

  18. Regulation and aggregation of intrinsically disordered peptides

    PubMed Central

    Levine, Zachary A.; Larini, Luca; LaPointe, Nichole E.; Feinstein, Stuart C.; Shea, Joan-Emma

    2015-01-01

    Intrinsically disordered proteins (IDPs) are a unique class of proteins that have no stable native structure, a feature that allows them to adopt a wide variety of extended and compact conformations that facilitate a large number of vital physiological functions. One of the most well-known IDPs is the microtubule-associated tau protein, which regulates microtubule growth in the nervous system. However, dysfunctions in tau can lead to tau oligomerization, fibril formation, and neurodegenerative disease, including Alzheimer’s disease. Using a combination of simulations and experiments, we explore the role of osmolytes in regulating the conformation and aggregation propensities of the R2/wt peptide, a fragment of tau containing the aggregating paired helical filament (PHF6*). We show that the osmolytes urea and trimethylamine N-oxide (TMAO) shift the population of IDP monomer structures, but that no new conformational ensembles emerge. Although urea halts aggregation, TMAO promotes the formation of compact oligomers (including helical oligomers) through a newly proposed mechanism of redistribution of water around the perimeter of the peptide. We put forth a “superposition of ensembles” hypothesis to rationalize the mechanism by which IDP structure and aggregation is regulated in the cell. PMID:25691742

  19. Regulation and aggregation of intrinsically disordered peptides.

    PubMed

    Levine, Zachary A; Larini, Luca; LaPointe, Nichole E; Feinstein, Stuart C; Shea, Joan-Emma

    2015-03-01

    Intrinsically disordered proteins (IDPs) are a unique class of proteins that have no stable native structure, a feature that allows them to adopt a wide variety of extended and compact conformations that facilitate a large number of vital physiological functions. One of the most well-known IDPs is the microtubule-associated tau protein, which regulates microtubule growth in the nervous system. However, dysfunctions in tau can lead to tau oligomerization, fibril formation, and neurodegenerative disease, including Alzheimer's disease. Using a combination of simulations and experiments, we explore the role of osmolytes in regulating the conformation and aggregation propensities of the R2/wt peptide, a fragment of tau containing the aggregating paired helical filament (PHF6*). We show that the osmolytes urea and trimethylamine N-oxide (TMAO) shift the population of IDP monomer structures, but that no new conformational ensembles emerge. Although urea halts aggregation, TMAO promotes the formation of compact oligomers (including helical oligomers) through a newly proposed mechanism of redistribution of water around the perimeter of the peptide. We put forth a "superposition of ensembles" hypothesis to rationalize the mechanism by which IDP structure and aggregation is regulated in the cell. PMID:25691742

  20. 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.

  1. 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. PMID:24204642

  2. Floating Ice-Algal Aggregates below Melting Arctic Sea Ice

    PubMed Central

    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. PMID:24204642

  3. 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. PMID:22623968

  4. 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.

  5. Gluon distribution functions and Higgs boson production at moderate transverse momentum

    SciTech Connect

    Sun Peng; Xiao Bowen; Yuan Feng

    2011-11-01

    We investigate the gluon distribution functions and their contributions to the Higgs boson production in pp collisions in the transverse momentum-dependent factorization formalism. In addition to the usual azimuthal symmetric transverse momentum-dependent gluon distribution, we find that the azimuthal correlated gluon distribution also contributes to the Higgs boson production. This explains recent findings on the additional contribution in the transverse momentum resummation for the Higgs boson production as compared to that for electroweak boson production processes. We further examine the small-x naive k{sub t}-factorization in the dilute region and find that the azimuthal correlated gluon distribution contribution is consistently taken into account. The result agrees with the transverse momentum-dependent factorization formalism. We comment on the possible breakdown of the naive k{sub t}-factorization in the dense medium region, due to the unique behaviors for the gluon distributions.

  6. Gluon distribution functions and Higgs boson production at moderate transverse momentum

    SciTech Connect

    Sun P.; Yuan F.; Xiao, B.W.

    2011-11-04

    We investigate the gluon distribution functions and their contributions to the Higgs boson production in pp collisions in the transverse momentum-dependent factorization formalism. In addition to the usual azimuthal symmetric transverse momentum-dependent gluon distribution, we find that the azimuthal correlated gluon distribution also contributes to the Higgs boson production. This explains recent findings on the additional contribution in the transverse momentum resummation for the Higgs boson production as compared to that for electroweak boson production processes. We further examine the small-x naive kt-factorization in the dilute region and find that the azimuthal correlated gluon distribution contribution is consistently taken into account. The result agrees with the transverse momentum-dependent factorization formalism. We comment on the possible breakdown of the naive kt-factorization in the dense medium region, due to the unique behaviors for the gluon distributions.

  7. 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

    2016-01-01

    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. PMID:26877167

  8. 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

  9. Peptide aggregation in neurodegenerative disease.

    PubMed

    Murphy, Regina M

    2002-01-01

    In the not-so-distant past, insoluble aggregated protein was considered as uninteresting and bothersome as yesterday's trash. More recently, protein aggregates have enjoyed considerable scientific interest, as it has become clear that these aggregates play key roles in many diseases. In this review, we focus attention on three polypeptides: beta-amyloid, prion, and huntingtin, which are linked to three feared neurodegenerative diseases: Alzheimer's, "mad cow," and Huntington's disease, respectively. These proteins lack any significant primary sequence homology, yet their aggregates possess very similar features, specifically, high beta-sheet content, fibrillar morphology, relative insolubility, and protease resistance. Because the aggregates are noncrystalline, secrets of their structure at nanometer resolution are only slowly yielding to X-ray diffraction, solid-state NMR, and other techniques. Besides structure, the aggregates may possess similar pathways of assembly. Two alternative assembly pathways have been proposed: the nucleation-elongation and the template-assisted mode. These two modes may be complementary, not mutually exclusive. Strategies for interfering with aggregation, which may provide novel therapeutic approaches, are under development. The structural similarities between protein aggregates of dissimilar origin suggest that therapeutic strategies successful against one disease may have broad utility in others. PMID:12117755

  10. 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…

  11. 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.

  12. A Consensus Method for the Prediction of ‘Aggregation-Prone’ Peptides in Globular Proteins

    PubMed Central

    Tsolis, Antonios C.; Papandreou, Nikos C.; Iconomidou, Vassiliki A.; Hamodrakas, Stavros J.

    2013-01-01

    The purpose of this work was to construct a consensus prediction algorithm of ‘aggregation-prone’ peptides in globular proteins, combining existing tools. This allows comparison of the different algorithms and the production of more objective and accurate results. Eleven (11) individual methods are combined and produce AMYLPRED2, a publicly, freely available web tool to academic users (http://biophysics.biol.uoa.gr/AMYLPRED2), for the consensus prediction of amyloidogenic determinants/‘aggregation-prone’ peptides in proteins, from sequence alone. The performance of AMYLPRED2 indicates that it functions better than individual aggregation-prediction algorithms, as perhaps expected. AMYLPRED2 is a useful tool for identifying amyloid-forming regions in proteins that are associated with several conformational diseases, called amyloidoses, such as Altzheimer's, Parkinson's, prion diseases and type II diabetes. It may also be useful for understanding the properties of protein folding and misfolding and for helping to the control of protein aggregation/solubility in biotechnology (recombinant proteins forming bacterial inclusion bodies) and biotherapeutics (monoclonal antibodies and biopharmaceutical proteins). PMID:23326595

  13. Mechanics of fire ant aggregations

    NASA Astrophysics Data System (ADS)

    Tennenbaum, Michael; Liu, Zhongyang; Hu, David; Fernandez-Nieves, Alberto

    2016-01-01

    Fire ants link their bodies to form aggregations; these can adopt a variety of structures, they can drip and spread, or withstand applied loads. Here, by using oscillatory rheology, we show that fire ant aggregations are viscoelastic. We find that, at the lowest ant densities probed and in the linear regime, the elastic and viscous moduli are essentially identical over the spanned frequency range, which highlights the absence of a dominant mode of structural relaxation. As ant density increases, the elastic modulus rises, which we interpret by alluding to ant crowding and subsequent jamming. When deformed beyond the linear regime, the aggregation flows, exhibiting shear-thinning behaviour with a stress load that is comparable to the maximum load the aggregation can withstand before individual ants are torn apart. Our findings illustrate the rich, collective mechanical behaviour that can arise in aggregations of active, interacting building blocks.

  14. Mechanics of fire ant aggregations.

    PubMed

    Tennenbaum, Michael; Liu, Zhongyang; Hu, David; Fernandez-Nieves, Alberto

    2016-01-01

    Fire ants link their bodies to form aggregations; these can adopt a variety of structures, they can drip and spread, or withstand applied loads. Here, by using oscillatory rheology, we show that fire ant aggregations are viscoelastic. We find that, at the lowest ant densities probed and in the linear regime, the elastic and viscous moduli are essentially identical over the spanned frequency range, which highlights the absence of a dominant mode of structural relaxation. As ant density increases, the elastic modulus rises, which we interpret by alluding to ant crowding and subsequent jamming. When deformed beyond the linear regime, the aggregation flows, exhibiting shear-thinning behaviour with a stress load that is comparable to the maximum load the aggregation can withstand before individual ants are torn apart. Our findings illustrate the rich, collective mechanical behaviour that can arise in aggregations of active, interacting building blocks. PMID:26501413

  15. 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.

  16. Imbibition kinetics of spherical aggregates

    NASA Astrophysics Data System (ADS)

    Hébraud, Pascal; Lootens, Didier; Debacker, Alban

    The imbibition kinetics of a millimeter-sized aggregate of 300 nm diameter colloidal particles by a wetting pure solvent is studied. Three successive regimes are observed : in the first one, the imbibition proceeds by compressing the air inside the aggregate. Then, the solvent stops when the pressure of the compressed air is equal to the Laplace pressure at the meniscus of the wetting solvent in the porous aggregate. The interface is pinned and the aggregate slowly degases, up to a point where the pressure of the entrapped air stops decreasing and is controlled by the Laplace pressure of small bubbles. Depending on the curvature of the bubble, the system may then be in an unstable state. The imbibition then starts again, but with an inner pressure in equilibrium with these bubbles. This last stage leads to the complete infiltration of the aggregate.

  17. Key structural and functional differences between early and advanced glycation products.

    PubMed

    Paradela-Dobarro, Beatriz; Rodiño-Janeiro, Bruno K; Alonso, Jana; Raposeiras-Roubín, Sergio; González-Peteiro, Mercedes; González-Juanatey, José R; Álvarez, Ezequiel

    2016-01-01

    Most of the studies on advanced glycation end products (AGE) have been carried out with uncharacterized mixtures of AGE, so the observed effects cannot be linked to defined structures. Therefore, we analysed the structural differences between glycated human serum albumin (gHSA), a low glycated protein, and AGE-human serum albumin (AGE-HSA), a high glycated protein, and we compared their effects on endothelial functionality. Specifically, we characterized glycation and composition on both early and advanced stage glycation products of gHSA and AGE-HSA by using the MALDI-TOF-mass spectrometry assay. Furthermore, we studied the effects of both types of glycation products on reactive oxygen species (ROS) production and in the expression of vascular and intercellular cell adhesion molecules (VCAM-1 and ICAM-1) on human umbilical endothelial cells (HUVEC). We also measured the adhesion of peripheral blood mononuclear cells (PBMC) to HUVEC. Low concentrations of gHSA enhanced long-lasting ROS production in HUVEC, whereas lower concentrations of AGE-HSA caused the anticipation of the induced extracellular ROS production. Both gHSA and AGE-HSA up-regulated the expression of VCAM-1 and ICAM-1 at mRNA levels. Nevertheless, only AGE-HSA increased protein levels and enhanced the adhesion of PBMC to HUVEC monolayers. Functional differences were observed between gHSA and AGE-HSA, causing the latter an anticipation of the pro-oxidant effects in comparison to gHSA. Moreover, although both molecules induced genetic up-regulation of adhesion molecules in HUVEC, only the high glycated protein functionally increased mononuclear cell adhesion to endothelial monolayers. These observations could have important clinical consequences in the development of diabetic vascular complications. PMID:26581238

  18. 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.

  19. TDP-43 Aggregation In Neurodegeneration: Are Stress Granules The Key?

    PubMed Central

    Dewey, Colleen M.; Cenik, Basar; Sephton, Chantelle F.; Johnson, Brett A.; Herz, Joachim; Yu, Gang

    2012-01-01

    The RNA-binding protein TDP-43 is strongly linked to neurodegeneration. Not only are mutations in the gene encoding TDP-43 associated with ALS and FTLD, but this protein is also a major constituent of pathological intracellular inclusions in these diseases. Recent studies have significantly expanded our understanding of TDP-43 physiology. TDP-43 is now known to play important roles in neuronal RNA metabolism. It binds to and regulates the splicing and stability of numerous RNAs encoding proteins involved in neuronal development, synaptic function and neurodegeneration. Thus, a loss of these essential functions is an attractive hypothesis regarding the role of TDP-43 in neurodegeneration. Moreover, TDP-43 is an aggregation-prone protein and, given the role of toxic protein aggregates in neurodegeneration, a toxic gain-of-function mechanism is another rational hypothesis. Importantly, ALS related mutations modulate the propensity of TDP-43 to aggregate in cell culture. Several recent studies have documented that cytoplasmic TDP-43 aggregates co-localize with stress granule markers. Stress granules are cytoplasmic inclusions that repress translation of a subset of RNAs in times of cellular stress, and several proteins implicated in neurodegeneration (i.e. Ataxin-2 and SMN) interact with stress granules. Thus, understanding the interplay between TDP-43 aggregation, stress granules and the effect of ALS-associated TDP-43 mutations may be the key to understanding the role of TDP-43 in neurodegeneration. We propose two models of TDP-43 aggregate formation. The “independent model” stipulates that TDP-43 aggregation is independent of stress granule formation, in contrast to the “precursor model” which presents the idea that stress granule formation contributes to a TDP-43 aggregate “seed” and that chronic stress leads to concentration-dependent TDP-43 aggregation. PMID:22405725

  20. Capillary hydrodynamic chromatography reveals temporal profiles of cell aggregates.

    PubMed

    Tang, Ya-Ru; Huang, Hsin-Yi; Hu, Jie-Bi; Rattinam, Rajesh; Li, Chun-Hsien; Chen, Yu-Chie; Urban, Pawel L

    2016-03-01

    Microbial cells are known to form aggregates. Such aggregates can be found in various matrices; for example, functional drinks. Capillary hydrodynamic chromatography (HDC) enables separation of particles by size using nanoliter-scale volumes of samples. Here we propose an approach based on HDC for characterisation of real samples containing aggregated and non-aggregated bacterial and fungal cells. Separation of cells and cell aggregates in HDC arises from the parabolic flow profile under laminar flow conditions. In the presented protocol, hydrodynamic separation is coupled with different on-line and off-line detectors (light absorption/scattering and microscopy). The method has successfully been applied in the monitoring of dynamic changes in the microbiome of probiotic drinks. Chromatographic profiles of yogurt and kefir samples obtained at different times during fermentation are in a good agreement with microscopic images. Moreover, thanks to the implementation of an area imaging detector, capillary HDC could be multiplexed and used to profile spatial gradients in cell suspensions, which arise in the course of sedimentation of cells and cell aggregates. This result shows compatibility of sedimentation analysis and capillary HDC. We believe that the approach may find applications in the profiling of functional foods and other matrices containing aggregated bioparticles. PMID:26873471