Response of the global surface ozone distribution to Northern Hemisphere sea surface temperature changes: implications for long-range transport

NASA Astrophysics Data System (ADS)

Yi, Kan; Liu, Junfeng; Ban-Weiss, George; Zhang, Jiachen; Tao, Wei; Cheng, Yanli; Tao, Shu

2017-07-01

The response of surface ozone (O3) concentrations to basin-scale warming and cooling of Northern Hemisphere oceans is investigated using the Community Earth System Model (CESM). Idealized, spatially uniform sea surface temperature (SST) anomalies of ±1 °C are individually superimposed onto the North Pacific, North Atlantic, and North Indian oceans. Our simulations suggest large seasonal and regional variability in surface O3 in response to SST anomalies, especially in the boreal summer. The responses of surface O3 associated with basin-scale SST warming and cooling have similar magnitude but are opposite in sign. Increasing the SST by 1 °C in one of the oceans generally decreases the surface O3 concentrations from 1 to 5 ppbv. With fixed emissions, SST increases in a specific ocean basin in the Northern Hemisphere tend to increase the summertime surface O3 concentrations over upwind regions, accompanied by a widespread reduction over downwind continents. We implement the integrated process rate (IPR) analysis in CESM and find that meteorological O3 transport in response to SST changes is the key process causing surface O3 perturbations in most cases. During the boreal summer, basin-scale SST warming facilitates the vertical transport of O3 to the surface over upwind regions while significantly reducing the vertical transport over downwind continents. This process, as confirmed by tagged CO-like tracers, indicates a considerable suppression of intercontinental O3 transport due to increased tropospheric stability at lower midlatitudes induced by SST changes. Conversely, the responses of chemical O3 production to regional SST warming can exert positive effects on surface O3 levels over highly polluted continents, except South Asia, where intensified cloud loading in response to North Indian SST warming depresses both the surface air temperature and solar radiation, and thus photochemical O3 production. Our findings indicate a robust linkage between basin-scale SST variability and continental surface O3 pollution, which should be considered in regional air quality management.

Textured-surface quartz resonator fluid density and viscosity monitor

DOEpatents

Martin, Stephen J.; Wiczer, James J.; Cernosek, Richard W.; Frye, Gregory C.; Gebert, Charles T.; Casaus, Leonard; Mitchell, Mary A.

1998-08-25

A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

Optimization of Biomass and 5-Aminolevulinic Acid Production by Rhodobacter sphaeroides ATCC17023 via Response Surface Methodology.

PubMed

Liu, Shuli; Zhang, Guangming; Li, Jianzheng; Li, Xiangkun; Zhang, Jie

2016-06-01

Microbial 5-aminolevulinic acid (ALA) produced from wastewater is considered as potential renewable energy. However, many hurdles are needed to be overcome such as the regulation of key influencing factors on ALA yield. Biomass and ALA production by Rhodobacter sphaeroides was optimized using response surface methodology. The culturing medium was artificial volatile fatty acids wastewater. Three additives were optimized, namely succinate and glycine that are precursors of ALA biosynthesis, and D-glucose that is an inhibitor of ALA dehydratase. The optimal conditions were achieved by analyzing the response surface plots. Statistical analysis showed that succinate at 8.56 mmol/L, glycine at 5.06 mmol/L, and D-glucose at 7.82 mmol/L were the best conditions. Under these optimal conditions, the highest biomass production and ALA yield of 3.55 g/L and 5.49 mg/g-biomass were achieved. Subsequent verification experiments at optimal values had the maximum biomass production of 3.41 ± 0.002 g/L and ALA yield of 5.78 ± 0.08 mg/g-biomass.

OmpA influences Escherichia coli biofilm formation by repressing cellulose production through the CpxRA two-component system.

PubMed

Ma, Qun; Wood, Thomas K

2009-10-01

Previously we discovered that OmpA of Escherichia coli increases biofilm formation on polystyrene surfaces (González Barrios et al., Biotechnol Bioeng, 93:188-200, 2006a). Here we show OmpA influences biofilm formation differently on hydrophobic and hydrophilic surfaces since it represses cellulose production which is hydrophilic. OmpA increased biofilm formation on polystyrene, polypropylene, and polyvinyl surfaces while it decreased biofilm formation on glass surfaces. Sand column assays corroborated that OmpA decreases attachment to hydrophilic surfaces. The ompA mutant formed sticky colonies, and the extracellular polysaccharide that caused stickiness was identified as cellulose. A whole-transcriptome study revealed that OmpA induces the CpxRA two-component signal transduction pathway that responds to membrane stress. CpxA phosphorylates CpxR and results in reduced csgD expression. Reduced CsgD production represses adrA expression and results in reduced cellulose production since CsgD and AdrA are responsible for 3,5-cyclic diguanylic acid and cellulose synthesis. Real-time polymerase chain reaction confirmed csgD and adrA are repressed by OmpA. Biofilm and cellulose assays with double deletion mutants adrA ompA, csgB ompA, and cpxR ompA confirmed OmpA decreased cellulose production and increased biofilm formation on polystyrene surfaces through CpxR and AdrA. Further evidence of the link between OmpA and the CpxRA system was that overproduction of OmpA disrupted the membrane and led to cell lysis. Therefore, OmpA inhibits cellulose production through the CpxRA stress response system, and this reduction in cellulose increases biofilm formation on hydrophobic surfaces.

Applying Central Composite Design and Response Surface Methodology to Optimize Growth and Biomass Production of Haemophilus influenzae Type b.

PubMed

Momen, Seyed Bahman; Siadat, Seyed Davar; Akbari, Neda; Ranjbar, Bijan; Khajeh, Khosro

2016-06-01

Haemophilus influenzae type b (Hib) is the leading cause of bacterial meningitis, otitis media, pneumonia, cellulitis, bacteremia, and septic arthritis in infants and young children. The Hib capsule contains the major virulence factor, and is composed of polyribosyl ribitol phosphate (PRP) that can induce immune system response. Vaccines consisting of Hib capsular polysaccharide (PRP) conjugated to a carrier protein are effective in the prevention of the infections. However, due to costly processes in PRP production, these vaccines are too expensive. To enhance biomass, in this research we focused on optimizing Hib growth with respect to physical factors such as pH, temperature, and agitation by using a response surface methodology (RSM). We employed a central composite design (CCD) and a response surface methodology to determine the optimum cultivation conditions for growth and biomass production of H. influenzae type b. The treatment factors investigated were initial pH, agitation, and temperature, using shaking flasks. After Hib cultivation and determination of dry biomass, analysis of experimental data was performed by the RSM-CCD. The model showed that temperature and pH had an interactive effect on Hib biomass production. The dry biomass produced in shaking flasks was about 5470 mg/L, which was under an initial pH of 8.5, at 250 rpm and 35° C. We found CCD and RSM very effective in optimizing Hib culture conditions, and Hib biomass production was greatly influenced by pH and incubation temperature. Therefore, optimization of the growth factors to maximize Hib production can lead to 1) an increase in bacterial biomass and PRP productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower risk of Hib infections.

Live Candida albicans suppresses production of reactive oxygen species in phagocytes.

PubMed

Wellington, Melanie; Dolan, Kristy; Krysan, Damian J

2009-01-01

Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-beta-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-beta-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-beta-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-beta-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism.

Live Candida albicans Suppresses Production of Reactive Oxygen Species in Phagocytes▿ †

PubMed Central

Wellington, Melanie; Dolan, Kristy; Krysan, Damian J.

2009-01-01

Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-β-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-β-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-β-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-β-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism. PMID:18981256

Application of response surface methodology for optimization of polygalacturonase production by Aspergillus niger.

PubMed

Yadav, Kaushlesh K; Garg, Neelima; Kumar, Devendra; Kumar, Sanjay; Singh, Achal; Muthukumar, M

2015-01-01

Polygalacturonase (PG) degrades pectin into D-galacturonic acid monomers and is used widely in food industry especially for juice clarification. In the present study,. fermentation conditions for polygalacturonase production by Asgergillus niger NAIMCCF-02958, using mango peel as substrate, were optimized using the 2(3) factorial design with central composite rotatable experimental design (CCRD) of response surface methodology (RSM). The maximum PG activity 723.66 U g(-1) was achieved under pH 4.0, temperature 30 degrees C and 2% inoculum by response surface curve. The experimental value of PG activity wkas higher 607.65 U g(-1) than the predicted value 511.75 U g(-1). Under the proposed optimized conditions, the determination coefficient (R2) was equal to 0.66 indicating that the model could explain 66% of the total variation as well as establish the relationship between the variables and the responses. ANOVA analysis and the three dimensional plots also confirmed interactions among the parameters.

Kansei, surfaces and perception engineering

NASA Astrophysics Data System (ADS)

Rosen, B.-G.; Eriksson, L.; Bergman, M.

2016-09-01

The aesthetic and pleasing properties of a product are important and add significantly to the meaning and relevance of a product. Customer sensation and perception are largely about psychological factors. There has been a strong industrial and academic need and interest for methods and tools to quantify and link product properties to the human response but a lack of studies of the impact of surfaces. In this study, affective surface engineering is used to illustrate and model the link between customer expectations and perception to controllable product surface properties. The results highlight the use of the soft metrology concept for linking physical and human factors contributing to the perception of products. Examples of surface applications of the Kansei methodology are presented from sauna bath, health care, architectural and hygiene tissue application areas to illustrate, discuss and confirm the strength of the methodology. In the conclusions of the study, future research in soft metrology is proposed to allow understanding and modelling of product perception and sensations in combination with a development of the Kansei surface engineering methodology and software tools.

The Role of Hierarchy in Response Surface Modeling of Wind Tunnel Data

NASA Technical Reports Server (NTRS)

DeLoach, Richard

2010-01-01

This paper is intended as a tutorial introduction to certain aspects of response surface modeling, for the experimentalist who has started to explore these methods as a means of improving productivity and quality in wind tunnel testing and other aerospace applications. A brief review of the productivity advantages of response surface modeling in aerospace research is followed by a description of the advantages of a common coding scheme that scales and centers independent variables. The benefits of model term reduction are reviewed. A constraint on model term reduction with coded factors is described in some detail, which requires such models to be well-formulated, or hierarchical. Examples illustrate the consequences of ignoring this constraint. The implication for automated regression model reduction procedures is discussed, and some opinions formed from the author s experience are offered on coding, model reduction, and hierarchy.

7 CFR 352.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... article. Any product or article of any character whatsoever (other than plants, plant products, soil... responsible custody of a plant, plant product, plant pest, soil, or other product or article subject to this... present. Ship. Any means of transportation by water. Soil. The loose surface material of the earth in...

7 CFR 352.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... article. Any product or article of any character whatsoever (other than plants, plant products, soil... responsible custody of a plant, plant product, plant pest, soil, or other product or article subject to this... present. Ship. Any means of transportation by water. Soil. The loose surface material of the earth in...

7 CFR 352.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... article. Any product or article of any character whatsoever (other than plants, plant products, soil... responsible custody of a plant, plant product, plant pest, soil, or other product or article subject to this... present. Ship. Any means of transportation by water. Soil. The loose surface material of the earth in...

7 CFR 352.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... article. Any product or article of any character whatsoever (other than plants, plant products, soil... responsible custody of a plant, plant product, plant pest, soil, or other product or article subject to this... present. Ship. Any means of transportation by water. Soil. The loose surface material of the earth in...

7 CFR 352.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... article. Any product or article of any character whatsoever (other than plants, plant products, soil... responsible custody of a plant, plant product, plant pest, soil, or other product or article subject to this... present. Ship. Any means of transportation by water. Soil. The loose surface material of the earth in...

Tannase production by Paecilomyces variotii.

PubMed

Battestin, Vania; Macedo, Gabriela Alves

2007-07-01

Surface response methodology was applied to the optimization of the laboratory scale production of tannase using a lineage of Paecilomyces variotii. A preliminary study was conducted to evaluate the effects of variables, including temperature ( degrees C), residue (%) (coffee husk:wheat bran), tannic acid (%) and salt solutions (%) on the production of tannase during 3, 5 and 7 days of fermentation. Among these variables, temperature, residues and tannic acid had significant effects on tannase production. The variables were optimized using surface response methodology. The best conditions for tannase production were: temperature (29-34 degrees C); tannic acid (8.5-14%); % residue (coffee husk:wheat bran 50:50) and incubation time of 5 days. The supplementation of external nitrogen and carbon sources at 0.4%, 0.8% and 1.2% concentration on tannase production were studied in the optimized medium. Three different nitrogen sources included yeast extract, ammonia nitrate and sodium nitrate along with carbon source (starch) were studied. Only ammonia nitrate showed a significant effect on tannase production. After the optimization process, the tannase activity increased 8.6-fold.

Modeling and optimization of fermentation variables for enhanced production of lactase by isolated Bacillus subtilis strain VUVD001 using artificial neural networking and response surface methodology.

PubMed

Venkateswarulu, T C; Prabhakar, K Vidya; Kumar, R Bharath; Krupanidhi, S

2017-07-01

Modeling and optimization were performed to enhance production of lactase through submerged fermentation by Bacillus subtilis VUVD001 using artificial neural networks (ANN) and response surface methodology (RSM). The effect of process parameters namely temperature (°C), pH, and incubation time (h) and their combinational interactions on production was studied in shake flask culture by Box-Behnken design. The model was validated by conducting an experiment at optimized process variables which gave the maximum lactase activity of 91.32 U/ml. Compared to traditional activity, 3.48-folds improved production was obtained after RSM optimization. This study clearly shows that both RSM and ANN models provided desired predictions. However, compared with RSM (R 2  = 0.9496), the ANN model (R 2  = 0.99456) gave a better prediction for the production of lactase.

The combination of simulation and response methodology and its application in an aggregate production plan

NASA Astrophysics Data System (ADS)

Chen, Zhiming; Feng, Yuncheng

1988-08-01

This paper describes an algorithmic structure for combining simulation and optimization techniques both in theory and practice. Response surface methodology is used to optimize the decision variables in the simulation environment. A simulation-optimization software has been developed and successfully implemented, and its application to an aggregate production planning simulation-optimization model is reported. The model's objective is to minimize the production cost and to generate an optimal production plan and inventory control strategy for an aircraft factory.

[Optimization of ethylene production from ethanol dehydration using Zn-Mn-Co/HZSM-5 by response surface methodology].

PubMed

Wang, Wei; Cheng, Keke; Xue, Jianwei; Zhang, Jian'an

2011-03-01

The effects of reaction temperature, ethanol concentration and weight hourly space velocity (WHSV) on the ethylene production from ethanol dehydration using zinc, manganese and cobalt modified HZSM-5 catalyst were investigated by response surface methodology (RSM). The results showed that the most significant effect among factors was reaction temperature and the factors had interaction. The optimum conditions were found as 34.4% ethanol concentration, 261.3 0 degrees C of reaction temperature and 1.18 h(-1) of WHSV, under these conditions the yield of ethylene achieved 98.69%.

Exo-pectinase production by Bacillus pumilus using different agricultural wastes and optimizing of medium components using response surface methodology.

PubMed

Tepe, Ozlem; Dursun, Arzu Y

2014-01-01

In this research, the production of exo-pectinase by Bacillus pumilus using different agricultural wastes was studied. Agricultural wastes containing pectin such as wheat bran, sugar beet pulp, sunflower plate, orange peel, banana peel, apple pomace and grape pomace were tested as substrates, and activity of exo-pectinase was determined only in the mediums containing sugar beet pulp and wheat bran. Then, effects of parameters such as concentrations of solid substrate (wheat bran and sugar beet pulp) (A), ammonium sulphate (B) and yeast extract (C) on the production of exo-pectinase were investigated by response surface methodology. First, wheat bran was used as solid substrate, and it was determined that exo-pectinase activity increased when relatively low concentrations of ammonium sulphate (0.12-0.21% w/v) and yeast extract (0.12-0.3% w/v) and relatively high wheat bran (~5-6% w/v) were used. Then, exo-pectinase production was optimized by response surface methodology using sugar beet pulp as a solid substrate. In comparison to P values of the coefficients, values of not greater than 0.05 of A and B (2) showed that the effect of these process variables in exo-pectinase production was important and that changes done in these variables will alter the enzyme activity.

How does whole ecosystem warming of a peatland affect methane production and consumption?

NASA Astrophysics Data System (ADS)

Hopple, A.; Brunik, K.; Keller, J.; Pfeifer-Meister, L.; Woerndle, G.; Zalman, C.; Hanson, P.; Bridgham, S. D.

2017-12-01

Peatlands are among Earth's most important terrestrial ecosystems due to their massive soil carbon (C) stores and significant release of methane (CH4) into the atmosphere. Methane has a sustained-flux global warming potential 45-times greater than carbon dioxide (CO2), and the accuracy of Earth system model projections relies on our mechanistic understanding of peatland CH4 cycling in the context of environmental change. The objective of this study was to determine, under in situ conditions, how heating of the peat profile affects ecosystem-level anaerobic C cycling. We assessed the response of CO2 and CH4 production, as well as the anaerobic oxidation of CH4 (AOM), in a boreal peatland following 13 months of deep peat heating (DPH) and 16 months of subsequent whole-ecosystem warming (surface and deep heating; WEW) as part of the Spruce and Peatland Responses Under Changing Environments (SPRUCE) project in northern Minnesota, USA. The study uses a regression-based experimental design including 5 temperature treatments that warmed the entire 2 m peat profile from 0 to +9 °C above ambient temperature. Soil cores were collected at multiple depths (25-200 cm) from each experimental chamber at the SPRUCE site and anaerobically incubated at in situ temperatures for 1-2 weeks. Methane and CO2 production in surface peat were positively correlated with elevated temperature, but no consistent temperature response was found at depth (75-200 cm) following DPH. However, during WEW, we observed significant increases in both surface and deep peat methanogenesis with increasing temperature. Surface peat had greater CH4 production rates than deeper peat, implying that the increased CH4 emissions observed in the field were largely driven by surface peat warming. The CO2:CH4 ratio was inversely correlated with temperature across all depths following 16 months of WEW, indicating that the entire peat profile is becoming more methanogenic with warming. We also observed AOM throughout the whole peat profile, with the highest rates observed at the surface and initial data suggesting a positive correlation with increasing temperature. While SPRUCE will continue for many years, our initial results suggest that the vast C stores at depth in peatlands are minimally responsive to warming and any response will be driven largely by surface peat.

Application of response surface methodology (RSM) and genetic algorithm in minimizing warpage on side arm

NASA Astrophysics Data System (ADS)

Raimee, N. A.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.

2017-09-01

The plastic injection moulding process produces large numbers of parts of high quality with great accuracy and quickly. It has widely used for production of plastic part with various shapes and geometries. Side arm is one of the product using injection moulding to manufacture it. However, there are some difficulties in adjusting the parameter variables which are mould temperature, melt temperature, packing pressure, packing time and cooling time as there are warpage happen at the tip part of side arm. Therefore, the work reported herein is about minimizing warpage on side arm product by optimizing the process parameter using Response Surface Methodology (RSM) and with additional artificial intelligence (AI) method which is Genetic Algorithm (GA).

Quartz resonator fluid density and viscosity monitor

DOEpatents

Martin, Stephen J.; Wiczer, James J.; Cernosek, Richard W.; Frye, Gregory C.; Gebert, Charles T.; Casaus, Leonard; Mitchell, Mary A.

1998-01-01

A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology.

PubMed

El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M; El-Ewasy, Sara M

2015-01-01

Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology.

Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology

PubMed Central

El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M.; El-Ewasy, Sara M.

2015-01-01

Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology. PMID:26180806

Modelling and Optimization Studies on a Novel Lipase Production by Staphylococcus arlettae through Submerged Fermentation

PubMed Central

Chauhan, Mamta; Chauhan, Rajinder Singh; Garlapati, Vijay Kumar

2013-01-01

Microbial enzymes from extremophilic regions such as hot spring serve as an important source of various stable and valuable industrial enzymes. The present paper encompasses the modeling and optimization approach for production of halophilic, solvent, tolerant, and alkaline lipase from Staphylococcus arlettae through response surface methodology integrated nature inspired genetic algorithm. Response surface model based on central composite design has been developed by considering the individual and interaction effects of fermentation conditions on lipase production through submerged fermentation. The validated input space of response surface model (with R 2 value of 96.6%) has been utilized for optimization through genetic algorithm. An optimum lipase yield of 6.5 U/mL has been obtained using binary coded genetic algorithm predicted conditions of 9.39% inoculum with the oil concentration of 10.285% in 2.99 hrs using pH of 7.32 at 38.8°C. This outcome could contribute to introducing this extremophilic lipase (halophilic, solvent, and tolerant) to industrial biotechnology sector and will be a probable choice for different food, detergent, chemical, and pharmaceutical industries. The present work also demonstrated the feasibility of statistical design tools integration with computational tools for optimization of fermentation conditions for maximum lipase production. PMID:24455210

Multi Response Optimization of Process Parameters Using Grey Relational Analysis for Turning of Al-6061

NASA Astrophysics Data System (ADS)

Deepak, Doreswamy; Beedu, Rajendra

2017-08-01

Al-6061 is one among the most useful material used in manufacturing of products. The major qualities of Aluminium are reasonably good strength, corrosion resistance and thermal conductivity. These qualities have made it a suitable material for various applications. While manufacturing these products, companies strive for reducing the production cost by increasing Material Removal Rate (MRR). Meanwhile, the quality of surface need to be ensured at an acceptable value. This paper aims at bringing a compromise between high MRR and low surface roughness requirement by applying Grey Relational Analysis (GRA). This article presents the selection of controllable parameters like longitudinal feed, cutting speed and depth of cut to arrive at optimum values of MRR and surface roughness (Ra). The process parameters for experiments were selected based on Taguchi’s L9 array with two replications. Grey relation analysis being most suited method for multi response optimization, the same is adopted for the optimization. The result shows that feed rate is the most significant factor that influences MRR and Surface finish.

Biomass removal and its effect on productivity of an artificially regenerated forest stand in the Missouri ozarks

Treesearch

Flex Jr. Ponder

2007-01-01

Intensive harvesting, which removes a greater proportion of the forest biomass than conventional harvesting and the associated nutrients, may cause a decline in forest productivity. Planted seedling response to three biomass removal levels (1. removal of boles only=OM1, 2. all surface organic matter removed, forest floor not removed=OM2, and 3. removal of all surface...

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO2 adsorption performance

NASA Astrophysics Data System (ADS)

Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

2017-06-01

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2k-1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m2/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO2 adsorption.

Operational Derivation of Surface Albedo and Down-Welling Short-Wave Radiation in the Satellite Application Facility for Land Surface Analysis

NASA Astrophysics Data System (ADS)

Geiger, B.; Carrer, D.; Meurey, C.; Roujean, J.-L.

2006-08-01

The Satellite Application Facility for Land Surface Anal- ysis hosted by the Portuguese Meteorological Institute in Lisbon generates and distributes value added satellite products for numerical weather prediction and environ- mental applications in near-real time. Within the project consortium M´et´eo-France is responsible for the land sur- face albedo and down-welling short-wave radiation flux products. Since the beginning of the year 2005 Meteosat Second Generation data are routinely processed by the Land-SAF operational system. In general the validation studies carried out so far show a good consistency with in-situ observations or equivalent products derived from other satellites. After one year of operations a summary of the product characteristics and performances is given. Key words: Surface Albedo; Down-welling Radiation; Land-SAF.

Response surface methodology for evaluation and optimization of process parameter and antioxidant capacity of rice flour modified by enzymatic extrusion.

PubMed

Xu, Enbo; Pan, Xiaowei; Wu, Zhengzong; Long, Jie; Li, Jingpeng; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

2016-12-01

For the purpose of investigating the effect of enzyme concentration (EC), barrel temperature (BT), moisture content (MC), and screw speed (SS) on processing parameters (product temperature, die pressure and special mechanical energy (SME)) and product responses (extent of gelatinization (GE), retention rate of total phenolic content (TPC-RR)), rice flour extruded with thermostable α-amylase was analyzed by response surface methodology. Stepwise regression models were computed to generate response surface and contour plots, revealing that both TPC-RR and GE increased as increasing MC while expressed different sensitivities to BT during enzymatic extrusion. Phenolics preservation was benefited from low SME. According to multiple-factor optimization, the conditions required to obtain the target SME (10kJ/kg), GE (100%) and TPC-RR (85%) were: EC=1.37‰, BT=93.01°C, MC=44.30%, and SS=171.66rpm, with the actual values (9.49kJ/kg, 99.96% and 87.10%, respectively) showing a good fit to the predicted values. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Warpage minimization on wheel caster by optimizing process parameters using response surface methodology (RSM)

NASA Astrophysics Data System (ADS)

Safuan, N. S.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.

2017-09-01

In injection moulding process, it is important to keep the productivity increase constantly with least of waste produced such as warpage defect. Thus, this study is concerning on minimizing warpage defect on wheel caster part. Apart from eliminating product wastes, this project also giving out best optimization techniques using response surface methodology. This research studied on five parameters A-packing pressure, B-packing time, C-mold temperature, D-melting temperature and E-cooling time. The optimization showed that packing pressure is the most significant parameter. Warpage have been improved 42.64% from 0.6524 mm to 0.3742mm.

Fortifying the Bone-Implant Interface Part 1: An In Vitro Evaluation of 3D-Printed and TPS Porous Surfaces.

PubMed

MacBarb, Regina F; Lindsey, Derek P; Bahney, Chelsea S; Woods, Shane A; Wolfe, Mark L; Yerby, Scott A

2017-01-01

An aging society and concomitant rise in the incidence of impaired bone health have led to the need for advanced osteoconductive spinal implant surfaces that promote greater biological fixation ( e.g. for interbody fusion cages, sacroiliac joint fusion implants, and artificial disc replacements). Additive manufacturing, i.e. 3D-printing, may improve bone integration by generating biomimetic spinal implant surfaces that mimic bone morphology. Such surfaces may foster an enhanced cellular response compared to traditional implant surfacing processes. This study investigated the response of human osteoblasts to additive manufactured (AM) trabecular-like titanium implant surfaces compared to traditionally machined base material with titanium plasma spray (TPS) coated surfaces, with and without a nanocrystalline hydroxyapatite (HA) coating. For TPS-coated discs, wrought Ti6Al4V ELI was machined and TPS-coating was applied. For AM discs, Ti6Al4V ELI powder was 3D-printed to form a solid base and trabecular-like porous surface. The HA-coating was applied via a precipitation dip-spin method. Surface porosity, pore size, thickness, and hydrophilicity were characterized. Initial cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium production of hFOB cells ( n =5 per group) were measured. Cells on AM discs exhibited expedited proliferative activity. While there were no differences in mean ALP expression and calcium production between TPS and AM discs, calcium production on the AM discs trended 48% higher than on TPS discs ( p =0.07). Overall, HA-coating did not further enhance results compared to uncoated TPS and AM discs. Results demonstrate that additive manufacturing allows for controlled trabecular-like surfaces that promote earlier cell proliferation and trends toward higher calcium production than TPS coating. Results further showed that nanocrystalline HA may not provide an advantage on porous titanium surfaces. Additive manufactured porous titanium surfaces may induce a more osteogenic environment compared to traditional TPS, and thus present as an attractive alternative to TPS-coating for orthopedic spinal implants.

Statistical optimization of beta-carotene production by Arthrobacter agilis A17 using response surface methodology and Box-Behnken design

NASA Astrophysics Data System (ADS)

Özdal, Murat; Özdal, Özlem Gür; Gürkök, Sümeyra

2017-04-01

β-carotene is a commercially important natural pigment and has been widely applied in the medicine, pharmaceutical, food, feed and cosmetic industries. The current study aimed to investigate the usability of molasses for β-carotene production by Arthrobacter agilis A17 (KP318146) and to optimize the production process. Box-Behnken Design of Response Surface Methodology was used to determine the optimum levels and the interactions of three independent variables namely molasses, yeast extract and KH2PO4 at three different levels. β-carotene yield in optimized medium containing 70 g/l molasses, 25 g/l yeast extract and 0.96 g/l KH2PO4, reached up to 100 mg/l, which is approximately 2.5-fold higher than the yield, obtained from control cultivation. A remarkable β-carotene production on inexpensive carbon source was achieved with the use of statistical optimization.

Response surface optimization of the critical medium components for pullulan production by Aureobasidium pullulans FB-1.

PubMed

Singh, Ram Sarup; Singh, Harpreet; Saini, Gaganpreet Kaur

2009-01-01

Culture conditions for pullulan production by Aureobasidium pullulans were optimized using response surface methodology at shake flask level without pH control. In the present investigation, a five-level with five-factor central composite rotatable design of experiments was employed to optimize the levels of five factors significantly affecting the pullulan production, biomass production, and sugar utilization in submerged cultivation. The selected factors included concentration of sucrose, ammonium sulphate, yeast extract, dipotassium hydrogen phosphate, and sodium chloride. Using this methodology, the optimal values for concentration of sucrose, ammonium sulphate, yeast extract, dipotassium hydrogen phosphate, and sodium chloride were 5.31%, 0.11%, 0.07%, 0.05%, and 0.15% (w/v), respectively. This optimized medium has projected a theoretically production of pullulan of 4.44%, biomass yield of 1.03%, and sugar utilization of 97.12%. The multiple correlation coefficient 'R' was 0.9976, 0.9761 and 0.9919 for pullulan production, biomass production, and sugar utilization, respectively. The value of R being very close to one justifies an excellent correlation between the predicted and the experimental data.

In Vitro Optimization of Enzymes Involved in Precorrin-2 Synthesis Using Response Surface Methodology.

PubMed

Fang, Huan; Dong, Huina; Cai, Tao; Zheng, Ping; Li, Haixing; Zhang, Dawei; Sun, Jibin

2016-01-01

In order to maximize the production of biologically-derived chemicals, kinetic analyses are first necessary for predicting the role of enzyme components and coordinating enzymes in the same reaction system. Precorrin-2 is a key precursor of cobalamin and siroheme synthesis. In this study, we sought to optimize the concentrations of several molecules involved in precorrin-2 synthesis in vitro: porphobilinogen synthase (PBGS), porphobilinogen deaminase (PBGD), uroporphyrinogen III synthase (UROS), and S-adenosyl-l-methionine-dependent urogen III methyltransferase (SUMT). Response surface methodology was applied to develop a kinetic model designed to maximize precorrin-2 productivity. The optimal molar ratios of PBGS, PBGD, UROS, and SUMT were found to be approximately 1:7:7:34, respectively. Maximum precorrin-2 production was achieved at 0.1966 ± 0.0028 μM/min, agreeing with the kinetic model's predicted value of 0.1950 μM/min. The optimal concentrations of the cofactor S-adenosyl-L-methionine (SAM) and substrate 5-aminolevulinic acid (ALA) were also determined to be 200 μM and 5 mM, respectively, in a tandem-enzyme assay. By optimizing the relative concentrations of these enzymes, we were able to minimize the effects of substrate inhibition and feedback inhibition by S-adenosylhomocysteine on SUMT and thereby increase the production of precorrin-2 by approximately five-fold. These results demonstrate the effectiveness of kinetic modeling via response surface methodology for maximizing the production of biologically-derived chemicals.

Comparative one-factor-at-a-time, response surface (statistical) and bench-scale bioreactor level optimization of thermoalkaline protease production from a psychrotrophic Pseudomonas putida SKG-1 isolate.

PubMed

Singh, Santosh K; Singh, Sanjay K; Tripathi, Vinayak R; Khare, Sunil K; Garg, Satyendra K

2011-12-28

Production of alkaline protease from various bacterial strains using statistical methods is customary now-a-days. The present work is first attempt for the production optimization of a solvent stable thermoalkaline protease by a psychrotrophic Pseudomonas putida isolate using conventional, response surface methods, and fermentor level optimization. The pre-screening medium amended with optimized (w/v) 1.0% glucose, 2.0% gelatin and 0.5% yeast extract, produced 278 U protease ml(-1) at 72 h incubation. Enzyme production increased to 431 Uml(-1) when Mg2+ (0.01%, w/v) was supplemented. Optimization of physical factors further enhanced protease to 514 Uml(-1) at pH 9.0, 25°C and 200 rpm within 60 h. The combined effect of conventionally optimized variables (glucose, yeast extract, MgSO4 and pH), thereafter predicted by response surface methodology yielded 617 U protease ml(-1) at glucose 1.25% (w/v), yeast extract 0.5% (w/v), MgSO4 0.01% (w/v) and pH 8.8. Bench-scale bioreactor level optimization resulted in enhanced production of 882 U protease ml(-1) at 0.8 vvm aeration and 150 rpm agitation during only 48 h incubation. The optimization of fermentation variables using conventional, statistical approaches and aeration/agitation at fermentor level resulted in ~13.5 folds increase (882 Uml(-1)) in protease production compared to un-optimized conditions (65 Uml(-1)). This is the highest level of thermoalkaline protease reported so far by any psychrotrophic bacterium.

Cellular Responses Evoked by Different Surface Characteristics of Intraosseous Titanium Implants

PubMed Central

Feller, Liviu; Jadwat, Yusuf; Khammissa, Razia A. G.; Meyerov, Robin; Lemmer, Johan

2015-01-01

The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration. PMID:25767803

Improved antimicrobial compound production by a new isolate Streptomyces hygroscopicus MTCC 4003 using Plackett-Burman design and response Surface methodology.

PubMed

Singh, Neha; Rai, Vibhuti

2012-01-01

An active strain, isolated from soil of Chhattisgarh, India, showed broad-spectrum antimicrobial activity against various pathogenic bacteria and fungi in glucose soybean meal broth. Strain was characterized as Streptomyces hygroscopicus MTCC 4003 based on 16S rRNA sequencing from Microbial Type culture Collection (MTCC), IMTECH, Chandigarh, India. Identification of the purified antimicrobial compound was done by using Infra-red (IR), Mass, Ultraviolet (UV), 1H and 13C nuclear magnetic resonance (NMR) spectra. Plackett-Burman design (PBD) and response surface methodology (RSM) methods were used for the optimization of antibiotic production. Effects of the four medium components soybean meal, glucose, CaCO3 and MgSO4 showed positive effect on antibiotic production, were investigated with the help of PBD. The individual and interaction effects of the selected variables were determined by RSM using central composite design (CCD). Applying statistical design, antibiotic production was improved nearly ten times (412 mg/L) compared with unoptimized production medium (37 mg/L).

Optimised isolation of polysaccharides from Lentinula edodes strain NCBI JX915793 using response surface methodology and their antibacterial activities.

PubMed

Sharma, Shivani; Khanna, P K; Kapoor, S

2016-01-01

Mycelial growth in a defined medium by submerged fermentation is a rapid and alternative method for obtaining fungal biomass of consistent quality. Biomass, exopolysaccharides (EPS) and intracellular polysaccharides (IPS) production were optimised by response surface methodology in Lentinula edodes strain LeS (NCBI JX915793). The optimised conditions were pH 5.0, temperature 26°C, incubation period of 25 days and agitation rate of 52 r/min for L. edodes strain LeS. Under the calculated optimal culture conditions, biomass production (5.88 mg mL(-1)), EPS production (0.40 mg mL(-1)) and IPS production (12.45 mg g(-1)) were in agreement with the predicted values for biomass (5.93 mg mL(-1)), EPS (0.55 mg mL(-1)) and IPS production (12.64 mg g(-1)). Crude lentinan exhibited highest antibacterial effects followed by alcoholic, crude and aqueous extracts. The results obtained may be useful for highly effective yield of biomass and bioactive metabolites.

Trophic dynamics of deep-sea megabenthos are mediated by surface productivity.

PubMed

Tecchio, Samuele; van Oevelen, Dick; Soetaert, Karline; Navarro, Joan; Ramírez-Llodra, Eva

2013-01-01

Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ(13)C and δ(15)N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation.

Trophic Dynamics of Deep-Sea Megabenthos Are Mediated by Surface Productivity

PubMed Central

Tecchio, Samuele; van Oevelen, Dick; Soetaert, Karline; Navarro, Joan; Ramírez-Llodra, Eva

2013-01-01

Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ13C and δ15N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation. PMID:23691098

Structural brain aging and speech production: a surface-based brain morphometry study.

PubMed

Tremblay, Pascale; Deschamps, Isabelle

2016-07-01

While there has been a growing number of studies examining the neurofunctional correlates of speech production over the past decade, the neurostructural correlates of this immensely important human behaviour remain less well understood, despite the fact that previous studies have established links between brain structure and behaviour, including speech and language. In the present study, we thus examined, for the first time, the relationship between surface-based cortical thickness (CT) and three different behavioural indexes of sublexical speech production: response duration, reaction times and articulatory accuracy, in healthy young and older adults during the production of simple and complex meaningless sequences of syllables (e.g., /pa-pa-pa/ vs. /pa-ta-ka/). The results show that each behavioural speech measure was sensitive to the complexity of the sequences, as indicated by slower reaction times, longer response durations and decreased articulatory accuracy in both groups for the complex sequences. Older adults produced longer speech responses, particularly during the production of complex sequence. Unique age-independent and age-dependent relationships between brain structure and each of these behavioural measures were found in several cortical and subcortical regions known for their involvement in speech production, including the bilateral anterior insula, the left primary motor area, the rostral supramarginal gyrus, the right inferior frontal sulcus, the bilateral putamen and caudate, and in some region less typically associated with speech production, such as the posterior cingulate cortex.

LAI is the major cause of divergence in CO2 fertilization effect in land surface models

NASA Astrophysics Data System (ADS)

Li, Q.; Luo, Y.; Lu, X.; Wang, Y.; Huang, X.; Lin, G., Sr.

2017-12-01

Concentration-carbon feedback (β), also called CO2 fertilization effect, is an important feedback between terrestrial ecosystems and atmosphere to alleviate global climate change. However, models participating in C4MIP and CMIP5 predicted diverse CO2 fertilization effects under future CO2 inceasing scenarios. Hence identifing the key processes dominating the divergence of β in land surface models is of significance. We calculated CO2 fertilization effects from leaf level, canopy gross productivity level, net ecosystem productivity level and ecosystem carbon stock level in Community Atmosphere Biosphere Land Exchange (CABLE) model. Our results identified LAI is the key factor dominating the divergence of β among C3 plants in CABLE model. Saturation of the ecosystem productivity to increasing CO2 is not only regulated by leaf-level response, but also the response of LAI to increasing CO2. The greatest variation among C3 plants at ecosystem level suggests that other processes such as different allocation patterns and soil carbon dynamics of various vegetation types are also responsible for the divergence. Our results indicate that processes regarding to LAI need to be better calibrated according to experiments and observations in order to better represent the response of ecosystem productivity to increasing CO2.

Forcing and Responses of the Surface Energy Budget at Summit, Greenland

NASA Astrophysics Data System (ADS)

Miller, Nathaniel B.

Energy exchange at the Greenland Ice Sheet surface governs surface temperature variability, a factor critical for representing increasing surface melt extent, which portends a rise in global sea level. A comprehensive set of cloud, tropospheric, near-surface and sub-surface measurements at Summit Station is utilized to determine the driving forces and subsequent responses of the surface energy budget (SEB). This budget includes radiative, turbulent, and ground heat fluxes, and ultimately controls the evolution of surface temperature. At Summit Station, clouds radiatively warm the surface in all months with an annual average cloud radiative forcing value of 33 W m -2, largely driven by the occurrence of liquid-bearing clouds. The magnitude of the surface temperature response is dependent on how turbulent and ground heat fluxes modulate changes to radiative forcing. Relationships between forcing terms and responding surface fluxes show that changes in the upwelling longwave radiation compensate for 65-85% (50- 60%) of the total change in radiative forcing in the winter (summer). The ground heat flux is the second largest response term (16% annually), especially during winter. Throughout the annual cycle, the sensible heat flux response is comparatively constant (9%) and latent heat flux response is only 1.5%, becoming more of a factor in modulating surface temperature responses during the summer. Combining annual cycles of these responses with cloud radiative forcing results, clouds warm the surface by an estimated 7.8°C annually. A reanalysis product (ERA-I), operational model (CFSv2), and climate model (CESM) are evaluated utilizing the comprehensive set of SEB observations and process-based relationships. Annually, surface temperatures in each model are warmer than observed with overall poor representation of the coldest surface temperatures. Process-based relationships between different SEB flux terms offer insight into how well a modeling framework represents physical processes and the ability to distinguish errors in forcing versus those in physical representation. Such relationships convey that all three models underestimate the response of surface temperatures to changes in radiative forcing. These results provide a method to expose model deficiencies and indicate the importance of representing surface, sub-surface and boundary-layer processes when portraying cloud impacts on surface temperature variability.

Low-fat meat sausages with fish oil: optimization of milk proteins and carrageenan contents using response surface methodology.

PubMed

Marchetti, L; Andrés, S C; Califano, A N

2014-03-01

Response surface methodology was used to analyze the effect of milk proteins and 2:1 κ:ι-carrageenans on cooking loss (CL), weight lost by centrifugation (WLC) and texture attributes of low-fat meat sausages with pre-emulsified fish oil. A central-composite design was used to develop models for the objective responses. Changes in carrageenans affected more the responses than milk proteins levels. Convenience functions were calculated for CL, WLC, hardness, and springiness of the product. Responses were optimized simultaneously minimizing CL and WLC; ranges for hardness and springiness corresponded to commercial products (20 g of pork fat/100 g). The optimum corresponded to 0.593 g of carrageenans/100 g and 0.320 g of milk proteins and its total lipid content was 6.3 g/100 g. This formulation was prepared and evaluated showing a good agreement between predicted and experimental responses. These additives could produce low-fat meat sausages with pre-emulsified fish oil with good nutritional quality and similar characteristics than traditional ones. Copyright © 2013 Elsevier Ltd. All rights reserved.

Marine mammal distribution in the open ocean: a comparison of ocean color data products and levant time scales

NASA Astrophysics Data System (ADS)

Ohern, J.

2016-02-01

Marine mammals are generally located in areas of enhanced surface primary productivity, though they may forage much deeper within the water column and higher on the food chain. Numerous studies over the past several decades have utilized ocean color data from remote sensing instruments (CZCS, MODIS, and others) to asses both the quantity and time scales over which surface primary productivity relates to marine mammal distribution. In areas of sustained upwelling, primary productivity may essentially grow in the secondary levels of productivity (the zooplankton and nektonic species on which marine mammals forage). However, in many open ocean habitats a simple trophic cascade does not explain relatively short time lags between enhanced surface productivity and marine mammal presence. Other dynamic features that entrain prey or attract marine mammals may be responsible for the correlations between marine mammals and ocean color. In order to investigate these features, two MODIS (moderate imaging spectroradiometer) data products, the concentration as well as the standard deviation of surface chlorophyll were used in conjunction with marine mammal sightings collected within Ecuadorian waters. Time lags between enhanced surface chlorophyll and marine mammal presence were on the order of 2-4 weeks, however correlations were much stronger when the standard deviation of spatially binned images was used, rather than the chlorophyll concentrations. Time lags also varied between Balaenopterid and Odontocete cetaceans. Overall, the standard deviation of surface chlorophyll proved a useful tool for assessing potential relationships between marine mammal sightings and surface chlorophyll.

Solar Irradiance Changes and Phytoplankton Productivity in Earth's Ocean Following Astrophysical Ionizing Radiation Events

NASA Astrophysics Data System (ADS)

Neale, Patrick J.; Thomas, Brian C.

2016-04-01

Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are production of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran productivity focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the ocean (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted productivity declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of productivity responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and productivity are low.

Local Adaptive Calibration of the GLASS Surface Incident Shortwave Radiation Product Using Smoothing Spline

NASA Astrophysics Data System (ADS)

Zhang, X.; Liang, S.; Wang, G.

2015-12-01

Incident solar radiation (ISR) over the Earth's surface plays an important role in determining the Earth's climate and environment. Generally, can be obtained from direct measurements, remotely sensed data, or reanalysis and general circulation models (GCMs) data. Each type of product has advantages and limitations: the surface direct measurements provide accurate but sparse spatial coverage, whereas other global products may have large uncertainties. Ground measurements have been normally used for validation and occasionally calibration, but transforming their "true values" spatially to improve the satellite products is still a new and challenging topic. In this study, an improved thin-plate smoothing spline approach is presented to locally "calibrate" the Global LAnd Surface Satellite (GLASS) ISR product using the reconstructed ISR data from surface meteorological measurements. The influences of surface elevation on ISR estimation was also considered in the proposed method. The point-based surface reconstructed ISR was used as the response variable, and the GLASS ISR product and the surface elevation data at the corresponding locations as explanatory variables to train the thin plate spline model. We evaluated the performance of the approach using the cross-validation method at both daily and monthly time scales over China. We also evaluated estimated ISR based on the thin-plate spline method using independent ground measurements at 10 sites from the Coordinated Enhanced Observation Network (CEON). These validation results indicated that the thin plate smoothing spline method can be effectively used for calibrating satellite derived ISR products using ground measurements to achieve better accuracy.

Multi-Response Optimization of Granaticinic Acid Production by Endophytic Streptomyces thermoviolaceus NT1, Using Response Surface Methodology

PubMed Central

Roy, Sudipta; Halder, Suman Kumar; Banerjee, Debdulal

2016-01-01

Streptomyces thermoviolaceus NT1, an endophytic isolate, was studied for optimization of granaticinic acid production. It is an antimicrobial metabolite active against even drug resistant bacteria. Different media, optimum glucose concentration, initial media pH, incubation temperature, incubation period, and inoculum size were among the selected parameters optimized in the one-variable-at-a-time (OVAT) approach, where glucose concentration, pH, and temperature were found to play a critical role in antibiotic production by this strain. Finally, the Box–Behnken experimental design (BBD) was employed with three key factors (selected after OVAT studies) for response surface methodological (RSM) analysis of this optimization study.RSM analysis revealed a multifactorial combination; glucose 0.38%, pH 7.02, and temperature 36.53 °C as the optimum conditions for maximum antimicrobial yield. Experimental verification of model analysis led to 3.30-fold (61.35 mg/L as compared to 18.64 mg/L produced in un-optimized condition) enhanced granaticinic acid production in ISP2 medium with 5% inoculum and a suitable incubation period of 10 days. So, the conjugated optimization study for maximum antibiotic production from Streptomyces thermoviolaceus NT1 was found to result in significantly higher yield, which might be exploited in industrial applications. PMID:28952581

Improved cellulase production by Botryosphaeria rhodina from OPEFB at low level moisture condition through statistical optimization.

PubMed

Bahrin, E K; Ibrahim, M F; Abd Razak, M N; Abd-Aziz, S; Shah, U K Md; Alitheen, N; Salleh, M Md

2012-01-01

The response surface method was applied in this study to improve cellulase production from oil palm empty fruit bunch (OPEFB) by Botryosphaeria rhodina. An experimental design based on a two-level factorial was employed to screen the significant environmental factors for cellulase production. The locally isolated fungus Botryosphaeria rhodina was cultivated on OPEFB under solid-state fermentation (SSF). From the analysis of variance (ANOVA), the initial moisture content, amount of substrate, and initial pH of nutrient supplied in the SSF system significantly influenced cellulase production. Then the optimization of the variables was done using the response surface method according to central composite design (CCD). Botryosphaeria rhodina exhibited its best performance with a high predicted value of FPase enzyme production (17.95 U/g) when the initial moisture content was at 24.32%, initial pH of nutrient was 5.96, and 3.98 g of substrate was present. The statistical optimization from actual experiment resulted in a significant increment of FPase production from 3.26 to 17.91 U/g (5.49-fold). High cellulase production at low moisture content is a very rare condition for fungi cultured in solid-state fermentation.

Production of Chitin from Penaeus vannamei By-Products to Pilot Plant Scale Using a Combination of Enzymatic and Chemical Processes and Subsequent Optimization of the Chemical Production of Chitosan by Response Surface Methodology.

PubMed

Vázquez, José A; Ramos, Patrícia; Mirón, Jesús; Valcarcel, Jesus; Sotelo, Carmen G; Pérez-Martín, Ricardo I

2017-06-16

The waste generated from shrimp processing contains valuable materials such as protein, carotenoids, and chitin. The present study describes a process at pilot plant scale to recover chitin from the cephalothorax of Penaeus vannamei using mild conditions. The application of a sequential enzymatic-acid-alkaline treatment yields 30% chitin of comparable purity to commercial sources. Effluents from the process are rich in protein and astaxanthin, and represent inputs for further by-product recovery. As a last step, chitin is deacetylated to produce chitosan; the optimal conditions are established by applying a response surface methodology (RSM). Under these conditions, deacetylation reaches 92% as determined by Proton Nuclear Magnetic Resonance (¹H-NMR), and the molecular weight (Mw) of chitosan is estimated at 82 KDa by gel permeation chromatography (GPC). Chitin and chitosan microstructures are characterized by Scanning Electron Microscopy (SEM).

Efficacy of "green" cleaning products with respect to common respiratory viruses and mold growth.

PubMed

Light, Ed

2009-05-01

Some disinfectants have been demonstrated to be effective against surface mold growth and/or viruses responsible for the spread of common respiratory infections. Antimicrobial efficacy of green cleaning products has generally not been established in these areas. In this survey, the author found that out of 27 products approved by Green Seal as hard surface cleaners, 26 do not claim antimicrobial capability. While some contained hydrogen peroxide, a compound with limited spectrum disinfection capabilities, only one was registered with the U.S. Environmental Protection Agency as antimicrobial. The need for additional research and documentation is discussed.

Fortifying the Bone-Implant Interface Part 1: An In Vitro Evaluation of 3D-Printed and TPS Porous Surfaces

PubMed Central

Lindsey, Derek P.; Bahney, Chelsea S.; Woods, Shane A.; Wolfe, Mark L.; Yerby, Scott A.

2017-01-01

Background An aging society and concomitant rise in the incidence of impaired bone health have led to the need for advanced osteoconductive spinal implant surfaces that promote greater biological fixation (e.g. for interbody fusion cages, sacroiliac joint fusion implants, and artificial disc replacements). Additive manufacturing, i.e. 3D-printing, may improve bone integration by generating biomimetic spinal implant surfaces that mimic bone morphology. Such surfaces may foster an enhanced cellular response compared to traditional implant surfacing processes. Methods This study investigated the response of human osteoblasts to additive manufactured (AM) trabecular-like titanium implant surfaces compared to traditionally machined base material with titanium plasma spray (TPS) coated surfaces, with and without a nanocrystalline hydroxyapatite (HA) coating. For TPS-coated discs, wrought Ti6Al4V ELI was machined and TPS-coating was applied. For AM discs, Ti6Al4V ELI powder was 3D-printed to form a solid base and trabecular-like porous surface. The HA-coating was applied via a precipitation dip-spin method. Surface porosity, pore size, thickness, and hydrophilicity were characterized. Initial cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium production of hFOB cells (n=5 per group) were measured. Results Cells on AM discs exhibited expedited proliferative activity. While there were no differences in mean ALP expression and calcium production between TPS and AM discs, calcium production on the AM discs trended 48% higher than on TPS discs (p=0.07). Overall, HA-coating did not further enhance results compared to uncoated TPS and AM discs. Conclusions Results demonstrate that additive manufacturing allows for controlled trabecular-like surfaces that promote earlier cell proliferation and trends toward higher calcium production than TPS coating. Results further showed that nanocrystalline HA may not provide an advantage on porous titanium surfaces. Clinical Relevance Additive manufactured porous titanium surfaces may induce a more osteogenic environment compared to traditional TPS, and thus present as an attractive alternative to TPS-coating for orthopedic spinal implants. PMID:28765799

Effect of Ethanol on Differential Protein Production and Expression of Potential Virulence Functions in the Opportunistic Pathogen Acinetobacter baumannii

PubMed Central

Nwugo, Chika C.; Arivett, Brock A.; Zimbler, Daniel L.; Gaddy, Jennifer A.; Richards, Ashley M.; Actis, Luis A.

2012-01-01

Acinetobacter baumannii persists in the medical environment and causes severe human nosocomial infections. Previous studies showed that low-level ethanol exposure increases the virulence of A. baumannii ATCC 17978. To better understand the mechanisms involved in this response, 2-D gel electrophoresis combined with mass spectrometry was used to investigate differential protein production in bacteria cultured in the presence or absence of ethanol. This approach showed that the presence of ethanol significantly induces and represses the production of 22 and 12 proteins, respectively. Although over 25% of the ethanol-induced proteins were stress-response related, the overall bacterial viability was uncompromised when cultured under these conditions. Production of proteins involved in lipid and carbohydrate anabolism was increased in the presence of ethanol, a response that correlates with increased carbohydrate biofilm content, enhanced biofilm formation on abiotic surfaces and decrease bacterial motility on semi-solid surfaces. The presence of ethanol also induced the acidification of bacterial cultures and the production of indole-3-acetic acid (IAA), a ubiquitous plant hormone that signals bacterial stress-tolerance and promotes plant-bacteria interactions. These responses could be responsible for the significantly enhanced virulence of A. baumannii ATCC 17978 cells cultured in the presence of ethanol when tested with the Galleria mellonella experimental infection model. Taken together, these observations provide new insights into the effect of ethanol in bacterial virulence. This alcohol predisposes the human host to infections by A. baumannii and could favor the survival and adaptation of this pathogen to medical settings and adverse host environments. PMID:23284824

Effect of ethanol on differential protein production and expression of potential virulence functions in the opportunistic pathogen Acinetobacter baumannii.

PubMed

Nwugo, Chika C; Arivett, Brock A; Zimbler, Daniel L; Gaddy, Jennifer A; Richards, Ashley M; Actis, Luis A

2012-01-01

Acinetobacter baumannii persists in the medical environment and causes severe human nosocomial infections. Previous studies showed that low-level ethanol exposure increases the virulence of A. baumannii ATCC 17978. To better understand the mechanisms involved in this response, 2-D gel electrophoresis combined with mass spectrometry was used to investigate differential protein production in bacteria cultured in the presence or absence of ethanol. This approach showed that the presence of ethanol significantly induces and represses the production of 22 and 12 proteins, respectively. Although over 25% of the ethanol-induced proteins were stress-response related, the overall bacterial viability was uncompromised when cultured under these conditions. Production of proteins involved in lipid and carbohydrate anabolism was increased in the presence of ethanol, a response that correlates with increased carbohydrate biofilm content, enhanced biofilm formation on abiotic surfaces and decrease bacterial motility on semi-solid surfaces. The presence of ethanol also induced the acidification of bacterial cultures and the production of indole-3-acetic acid (IAA), a ubiquitous plant hormone that signals bacterial stress-tolerance and promotes plant-bacteria interactions. These responses could be responsible for the significantly enhanced virulence of A. baumannii ATCC 17978 cells cultured in the presence of ethanol when tested with the Galleria mellonella experimental infection model. Taken together, these observations provide new insights into the effect of ethanol in bacterial virulence. This alcohol predisposes the human host to infections by A. baumannii and could favor the survival and adaptation of this pathogen to medical settings and adverse host environments.

Analysis of parameter and interaction between parameter of the microwave assisted transesterification process of coconut oil using response surface methodology

NASA Astrophysics Data System (ADS)

Hidayanti, Nur; Suryanto, A.; Qadariyah, L.; Prihatini, P.; Mahfud, Mahfud

2015-12-01

A simple batch process was designed for the transesterification of coconut oil to alkyl esters using microwave assisted method. The product with yield above 93.225% of alkyl ester is called the biodiesel fuel. Response surface methodology was used to design the experiment and obtain the maximum possible yield of biodiesel in the microwave-assisted reaction from coconut oil with KOH as the catalyst. The results showed that the time reaction and concentration of KOH catalyst have significant effects on yield of alkyl ester. Based on the response surface methodology using the selected operating conditions, the time of reaction and concentration of KOH catalyst in transesterification process were 150 second and 0.25%w/w, respectively. The largest predicted and experimental yield of alkyl esters (biodiesel) under the optimal conditions are 101.385% and 93.225%, respectively. Our findings confirmed the successful development of process for the transesterification reaction of coconut oil by microwave-assisted heating, which is effective and time-saving for alkyl ester production.

Polypropylene Production Optimization in Fluidized Bed Catalytic Reactor (FBCR): Statistical Modeling and Pilot Scale Experimental Validation

PubMed Central

Khan, Mohammad Jakir Hossain; Hussain, Mohd Azlan; Mujtaba, Iqbal Mohammed

2014-01-01

Propylene is one type of plastic that is widely used in our everyday life. This study focuses on the identification and justification of the optimum process parameters for polypropylene production in a novel pilot plant based fluidized bed reactor. This first-of-its-kind statistical modeling with experimental validation for the process parameters of polypropylene production was conducted by applying ANNOVA (Analysis of variance) method to Response Surface Methodology (RSM). Three important process variables i.e., reaction temperature, system pressure and hydrogen percentage were considered as the important input factors for the polypropylene production in the analysis performed. In order to examine the effect of process parameters and their interactions, the ANOVA method was utilized among a range of other statistical diagnostic tools such as the correlation between actual and predicted values, the residuals and predicted response, outlier t plot, 3D response surface and contour analysis plots. The statistical analysis showed that the proposed quadratic model had a good fit with the experimental results. At optimum conditions with temperature of 75°C, system pressure of 25 bar and hydrogen percentage of 2%, the highest polypropylene production obtained is 5.82% per pass. Hence it is concluded that the developed experimental design and proposed model can be successfully employed with over a 95% confidence level for optimum polypropylene production in a fluidized bed catalytic reactor (FBCR). PMID:28788576

[Optimization of succinic acid fermentation with Actinobacillus succinogenes by response surface methodology].

PubMed

Shen, Naikun; Qin, Yan; Wang, Qingyan; Xie, Nengzhong; Mi, Huizhi; Zhu, Qixia; Liao, Siming; Huang, Ribo

2013-10-01

Succinic acid is an important C4 platform chemical in the synthesis of many commodity and special chemicals. In the present work, different compounds were evaluated for succinic acid production by Actinobacillus succinogenes GXAS 137. Important parameters were screened by the single factor experiment and Plackeet-Burman design. Subsequently, the highest production of succinic acid was approached by the path of steepest ascent. Then, the optimum values of the parameters were obtained by Box-Behnken design. The results show that the important parameters were glucose, yeast extract and MgCO3 concentrations. The optimum condition was as follows (g/L): glucose 70.00, yeast extract 9.20 and MgCO3 58.10. Succinic acid yield reached 47.64 g/L at the optimal condition. Succinic acid increased by 29.14% than that before the optimization (36.89 g/L). Response surface methodology was proven to be a powerful tool to optimize succinic acid production.

Optimization of L-asparaginase production from novel Enterobacter sp., by submerged fermentation using response surface methodology.

PubMed

Erva, Rajeswara Reddy; Goswami, Ajgebi Nath; Suman, Priyanka; Vedanabhatla, Ravali; Rajulapati, Satish Babu

2017-03-16

The culture conditions and nutritional rations influencing the production of extra cellular antileukemic enzyme by novel Enterobacter aerogenes KCTC2190/MTCC111 were optimized in shake-flask culture. Process variables like pH, temperature, incubation time, carbon and nitrogen sources, inducer concentration, and inoculum size were taken into account. In the present study, finest enzyme activity achieved by traditional one variable at a time method was 7.6 IU/mL which was a 2.6-fold increase compared to the initial value. Further, the L-asparaginase production was optimized using response surface methodology, and validated experimental result at optimized process variables gave 18.35 IU/mL of L-asparaginase activity, which is 2.4-times higher than the traditional optimization approach. The study explored the E. aerogenes MTCC111 as a potent and potential bacterial source for high yield of antileukemic drug.

Optimization of culture conditions and bench-scale production of L-asparaginase by submerged fermentation of Aspergillus terreus MTCC 1782.

PubMed

Gurunathan, Baskar; Sahadevan, Renganathan

2012-07-01

Optimization of culture conditions for L-asparaginase production by submerged fermentation of Aspergillus terreus MTCC 1782 was studied using a 3-level central composite design of response surface methodology and artificial neural network linked genetic algorithm. The artificial neural network linked genetic algorithm was found to be more efficient than response surface methodology. The experimental L-asparaginase activity of 43.29 IU/ml was obtained at the optimum culture conditions of temperature 35 degrees C, initial pH 6.3, inoculum size 1% (v/v), agitation rate 140 rpm, and incubation time 58.5 h of the artificial neural network linked genetic algorithm, which was close to the predicted activity of 44.38 IU/ml. Characteristics of L-asparaginase production by A. terreus MTCC 1782 were studied in a 3 L bench-scale bioreactor.

Optimum surface roughness prediction for titanium alloy by adopting response surface methodology

NASA Astrophysics Data System (ADS)

Yang, Aimin; Han, Yang; Pan, Yuhang; Xing, Hongwei; Li, Jinze

Titanium alloy has been widely applied in industrial engineering products due to its advantages of great corrosion resistance and high specific strength. This paper investigated the processing parameters for finish turning of titanium alloy TC11. Firstly, a three-factor central composite design of experiment, considering the cutting speed, feed rate and depth of cut, are conducted in titanium alloy TC11 and the corresponding surface roughness are obtained. Then a mathematic model is constructed by the response surface methodology to fit the relationship between the process parameters and the surface roughness. The prediction accuracy was verified by the one-way ANOVA. Finally, the contour line of the surface roughness under different combination of process parameters are obtained and used for the optimum surface roughness prediction. Verification experimental results demonstrated that material removal rate (MRR) at the obtained optimum can be significantly improved without sacrificing the surface roughness.

Application of response surface methodology to maximize the productivity of scalable automated human embryonic stem cell manufacture.

PubMed

Ratcliffe, Elizabeth; Hourd, Paul; Guijarro-Leach, Juan; Rayment, Erin; Williams, David J; Thomas, Robert J

2013-01-01

Commercial regenerative medicine will require large quantities of clinical-specification human cells. The cost and quality of manufacture is notoriously difficult to control due to highly complex processes with poorly defined tolerances. As a step to overcome this, we aimed to demonstrate the use of 'quality-by-design' tools to define the operating space for economic passage of a scalable human embryonic stem cell production method with minimal cell loss. Design of experiments response surface methodology was applied to generate empirical models to predict optimal operating conditions for a unit of manufacture of a previously developed automatable and scalable human embryonic stem cell production method. Two models were defined to predict cell yield and cell recovery rate postpassage, in terms of the predictor variables of media volume, cell seeding density, media exchange and length of passage. Predicted operating conditions for maximized productivity were successfully validated. Such 'quality-by-design' type approaches to process design and optimization will be essential to reduce the risk of product failure and patient harm, and to build regulatory confidence in cell therapy manufacturing processes.

Response surface optimization of medium components for naringinase production from Staphylococcus xylosus MAK2.

PubMed

Puri, Munish; Kaur, Aneet; Singh, Ram Sarup; Singh, Anubhav

2010-09-01

Response surface methodology was used to optimize the fermentation medium for enhancing naringinase production by Staphylococcus xylosus. The first step of this process involved the individual adjustment and optimization of various medium components at shake flask level. Sources of carbon (sucrose) and nitrogen (sodium nitrate), as well as an inducer (naringin) and pH levels were all found to be the important factors significantly affecting naringinase production. In the second step, a 22 full factorial central composite design was applied to determine the optimal levels of each of the significant variables. A second-order polynomial was derived by multiple regression analysis on the experimental data. Using this methodology, the optimum values for the critical components were obtained as follows: sucrose, 10.0%; sodium nitrate, 10.0%; pH 5.6; biomass concentration, 1.58%; and naringin, 0.50% (w/v), respectively. Under optimal conditions, the experimental naringinase production was 8.45 U/mL. The determination coefficients (R(2)) were 0.9908 and 0.9950 for naringinase activity and biomass production, respectively, indicating an adequate degree of reliability in the model.

Tannase production by Penicillium purpurogenum PAF6 in solid state fermentation of tannin-rich plant residues following OVAT and RSM.

PubMed

Jana, Arijit; Maity, Chiranjit; Halder, Suman Kumar; Mondal, Keshab Chandra; Pati, Bikash Ranjan; Mohapatra, Pradeep Kumar Das

2012-07-01

Tannase production by newly isolated Penicillium purpurogenum PAF6 was investigated by 'one variable at a time' (OVAT) approach followed by response surface methodology (RSM). Tannin-rich plant residues were used as supporting solid substrate and sole carbon source and, among them, tamarind seed was found to be the most favorable substrate than haritaki, pomegranate, tea leaf waste and arjun fruit. Physicochemical parameters were initially optimized using OVAT methodology and some important factors like incubation time, incubation temperature, substrate:moisture ratio as well as carbon, nitrogen and phosphate concentrations were verified with Box-Behken design of response surface methodology. Phosphate source, nitrogen source and temperature were found as the most favorable variables in the maximization of production. Tannase production was enhanced from 1.536 U/g to 5.784 U/g using tamarind seed OVAT optimization and further enhancement up to 6.15 U/g following RSM. An overall 3.76- and 4.0-fold increases in tannase production were achieved in OVAT and RSM, respectively.

Enhancement of docosahexaenoic acid production by Schizochytrium SW1 using response surface methodology

NASA Astrophysics Data System (ADS)

Nazir, Mohd Yusuf Mohd; Al-Shorgani, Najeeb Kaid Nasser; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

2015-09-01

In this study, three factors (fructose concentration, agitation speed and monosodium glutamate (MSG) concentration) were optimized to enhance DHA production by Schizochytrium SW1 using response surface methodology (RSM). Central composite design was applied as the experimental design and analysis of variance (ANOVA) was used to analyze the data. The experiments were conducted using 500 mL flask with 100 mL working volume at 30°C for 96 hours. ANOVA analysis revealed that the process was adequately represented significantly by the quadratic model (p<0.0001) and two of the factors namely agitation speed and MSG concentration significantly affect DHA production (p<0.005). Level of influence for each variable and quadratic polynomial equation were obtained for DHA production by multiple regression analyses. The estimated optimum conditions for maximizing DHA production by SW1 were 70 g/L fructose, 250 rpm agitation speed and 12 g/L MSG. Consequently, the quadratic model was validated by applying of the estimated optimum conditions, which confirmed the model validity and 52.86% of DHA was produced.

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO{sub 2} adsorption performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sargazi, Ghasem, E-mail: g.sargazi@gmail.com; Young Researchers Society, Shahid Bahonar University of Kerman, Kerman, Iran; Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com

2017-06-15

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2{sup k-1} factorial design experiments, and the response surfacemore » optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m{sup 2}/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO{sub 2} adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.« less

Optimization of maltodextrin production from avocado seed starch by response surface methodology

NASA Astrophysics Data System (ADS)

Nguyen, Thanh Viet; Ma, Tuyen-Hoang Nguyen; Nguyen, Tha Thi; Ho, Vinh-Nghi Kim; Vo, Hau Tan

2018-04-01

A process for maltodextrin production from avocado seed starch was reported in this study. Response surface methodology was used to investigate the effects of three independent variables for hydrolysis of the starch using a commercial food-grade α-amylase, Termamyl SC. These variables included enzyme concentration (0.05 - 0.15% starch), pH (5.0 - 6.0) and hydrolysis time (1.0 - 3.0 h), while the temperature fixed at 95°C. The result showed that the optimum conditions were using enzyme concentration at 0.12%, pH at 5.5 and 2.75 h of the incubation time. Under the optimum conditions, the recovered starch yield was 79.8% and the maltodextrin powder had 15.8 of dextrose equivalent.

Physical simulation of the response of the Enserch Garden Banks 388 FPF/free standing rigid riser to wind, waves, and current

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, R.Y.; Johnson, T.L.; Johnson, R.P.

1995-12-31

This paper describes large scale hydrodynamic model tests of the Enserch Exploration Garden Banks 388 Floating Production Facility (FPF). This unique facility consists of a semi-submersible connected to a template on the sea floor 2,096 feet below the surface through a buoyant, free standing ``rigid`` riser. The top of the riser and its manifold are located well below the surface to minimize the forces exerted on the riser by waves. Numerous flexible conductors connect the semi-submersible to the manifold on the top of the riser. The emphasis of the model test program was to confirm the estimates of: The structuralmore » response of the buoyant, rigid production riser and an adjacent drilling riser; The relative displacements between the semisubmersible and the production riser; The relative displacements between the production riser and drilling riser; and The forces which must be endured by the tensioners and flexible hoses which join the semi-submersible to the production riser. The paper describes the planning and preparation of the model components, the unique aspects of the simulation of the environments and the structural properties of the models, the execution of the experiments and the handling of the large number of measurements necessary to characterize the response of the multi-component system. Finally, the data analysis tools which were employed to provide an understanding of the responses of the system are discussed. 22 figs., 1 tab.« less

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. © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

Optimization of process parameters for the production of collagen peptides from fish skin (Epinephelus malabaricus) using response surface methodology and its characterization.

PubMed

Hema, G S; Joshy, C G; Shyni, K; Chatterjee, Niladri S; Ninan, George; Mathew, Suseela

2017-02-01

The study optimized the hydrolysis conditions for the production of fish collagen peptides from skin of Malabar grouper ( Epinephelus malabaricus ) using response surface methodology. The hydrolysis was done with enzymes pepsin, papain and protease from bovine pancreas. Effects of process parameters viz: pH, temperature, enzyme substrate ratio and hydrolysis time of the three different enzymes on degree of hydrolysis were investigated. The optimum response of degree of hydrolysis was estimated to be 10, 20 and 28% respectively for pepsin, papain and protease. The functional properties of the product developed were analysed which showed changes in the properties from proteins to peptides. SDS-PAGE combined with MALDI TOF method was successfully applied to determine the molecular weight distribution of the hydrolysate. The electrophoretic pattern indicated that the molecular weights of peptides formed due to hydrolysis were nearly 2 kDa. MALDI TOF spectral analysis showed the developed hydrolysate contains peptides having molecular weight in the range below 2 kDa.

Photo-Oxidation Products of Skin Surface Squalene Mediate Metabolic and Inflammatory Responses to Solar UV in Human Keratinocytes

PubMed Central

Kostyuk, Vladimir; Potapovich, Alla; Stancato, Andrea; De Luca, Chiara; Lulli, Daniela; Pastore, Saveria; Korkina, Liudmila

2012-01-01

The study aimed to identify endogenous lipid mediators of metabolic and inflammatory responses of human keratinocytes to solar UV irradiation. Physiologically relevant doses of solar simulated UVA+UVB were applied to human skin surface lipids (SSL) or to primary cultures of normal human epidermal keratinocytes (NHEK). The decay of photo-sensitive lipid-soluble components, alpha-tocopherol, squalene (Sq), and cholesterol in SSL was analysed and products of squalene photo-oxidation (SqPx) were quantitatively isolated from irradiated SSL. When administered directly to NHEK, low-dose solar UVA+UVB induced time-dependent inflammatory and metabolic responses. To mimic UVA+UVB action, NHEK were exposed to intact or photo-oxidised SSL, Sq or SqPx, 4-hydroxy-2-nonenal (4-HNE), and the product of tryptophan photo-oxidation 6-formylindolo[3,2-b]carbazole (FICZ). FICZ activated exclusively metabolic responses characteristic for UV, i.e. the aryl hydrocarbon receptor (AhR) machinery and downstream CYP1A1/CYP1B1 gene expression, while 4-HNE slightly stimulated inflammatory UV markers IL-6, COX-2, and iNOS genes. On contrast, SqPx induced the majority of metabolic and inflammatory responses characteristic for UVA+UVB, acting via AhR, EGFR, and G-protein-coupled arachidonic acid receptor (G2A). Conclusions/Significance Our findings indicate that Sq could be a primary sensor of solar UV irradiation in human SSL, and products of its photo-oxidation mediate/induce metabolic and inflammatory responses of keratinocytes to UVA+UVB, which could be relevant for skin inflammation in the sun-exposed oily skin. PMID:22952984

Optimizing culture conditions for production of intra and extracellular inulinase and invertase from Aspergillus niger ATCC 20611 by response surface methodology (RSM).

PubMed

Dinarvand, Mojdeh; Rezaee, Malahat; Foroughi, Majid

The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R 2 ) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30°C, 6% (v/v), inoculum size and 150rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Medium optimization for ε-poly-L-lysine production by Streptomyces diastatochromogenes using response surface methodology.

PubMed

Guo, F; Zheng, H; Cheng, Y; Song, S; Zheng, Z; Jia, S

2018-02-01

Poly-ε-L-lysine is a natural homo-polyamide of L-lysine with excellent antimicrobial properties, which can be used as a novel preservative and has a wide range of applications. In this paper, the fermentation medium for ε-PL production by Streptomyces diastatochromogenes 6#-7 was optimized by Response Surface Methodology. The results of Plackett-Burman design showed that glucose, yeast extract and (NH 4 ) 2 SO 4 were the major influencing factors in ε-PL production of S. diastatochromogenes 6#-7. The optimal concentrations of glucose, yeast extract and (NH 4 ) 2 SO 4 were determined to be 60, 7·5 and 7·5 g l -1 according to Box-Behnken experiment and regression analysis, respectively. Under the optimized conditions, the ε-PL yield in shake-flask fermentation was 0·948 ± 0·030 g l -1 , which was in good agreement with the predicted value of 0·970 g l -1 . The yield was improved by 43·1% from that with the initial medium. In 5 l jar-fermenter the ε-PL yield reached 25·5 g l -1 , which was increased by 56·4% from the original medium. In addition, the fermentation time was reduced from 174 to 120 h. Medium optimization is a very practical and valuable tool for fermentation industry to improve product yield and minimize by-products as well as reduce overall manufacturing costs. The response surface methodology is not new, but it is still a very effective method in medium optimization research. This study used ε-polylysine fermentation as an example to demonstrate how the product yield can be significantly increased by medium optimization through surface response methodology. Similar approach can be used in other microbial fermentations such as in pharmaceutical, food, agricultural and energy industries. As an example, ε-polylysine is one of a few newly approved natural food-grade antimicrobials for food and beverages preservations. Yield improvement is economically beneficial to not only ε-polylysine manufacturers but also to their users and consumers due to lower costs and price. © 2017 The Society for Applied Microbiology.

Application of the Response Surface Methodology to Optimize the Fermentation Parameters for Enhanced Docosahexaenoic Acid (DHA) Production by Thraustochytrium sp. ATCC 26185.

PubMed

Wu, Kang; Ding, Lijian; Zhu, Peng; Li, Shuang; He, Shan

2018-04-22

The aim of this study was to determine the cumulative effect of fermentation parameters and enhance the production of docosahexaenoic acid (DHA) by Thraustochytrium sp. ATCC 26185 using response surface methodology (RSM). Among the eight variables screened for effects of fermentation parameters on DHA production by Plackett-Burman design (PBD), the initial pH, inoculum volume, and fermentation volume were found to be most significant. The Box-Behnken design was applied to derive a statistical model for optimizing these three fermentation parameters for DHA production. The optimal parameters for maximum DHA production were initial pH: 6.89, inoculum volume: 4.16%, and fermentation volume: 140.47 mL, respectively. The maximum yield of DHA production was 1.68 g/L, which was in agreement with predicted values. An increase in DHA production was achieved by optimizing the initial pH, fermentation, and inoculum volume parameters. This optimization strategy led to a significant increase in the amount of DHA produced, from 1.16 g/L to 1.68 g/L. Thraustochytrium sp. ATCC 26185 is a promising resource for microbial DHA production due to the high-level yield of DHA that it produces, and the capacity for large-scale fermentation of this organism.

Application of response surface methodology for studying the product characteristics of extruded rice-cowpea-groundnut blends.

PubMed

Asare, Emmanuel Kwasi; Sefa-Dedeh, Samuel; Sakyi-Dawson, Esther; Afoakwa, Emmanuel Ohene

2004-08-01

Response surface methodology (with central composite rotatable design for k=3) was used to investigate the product properties of extruded rice-cowpea-groundnut blends in a single screw extruder. The combined effect of cowpea (0-20%), groundnut (0-10%), and feed moisture (14-48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded rice-legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R(2) values ranging from 52.8% (for the b-value) to 86.5% (for bulk density). The models developed suggested that the optimal process variables for the production of a puffed snack with an enhanced nutrition and spongy structure from a rice-cowpea-groundnut blend are low feed moisture of 14-20% and maximum additions of 20% cowpea and 10% groundnut. A lack-of-fit test showed no significance, indicating that the models adequately fitted the data.

Optimization of the preparation conditions of ceramic products using drinking water treatment sludges.

PubMed

Zamora, R M Ramirez; Ayala, F Espesel; Garcia, L Chavez; Moreno, A Duran; Schouwenaars, R

2008-11-01

The aim of this work is to optimize, via Response Surface Methodology, the values of the main process parameters for the production of ceramic products using sludges obtained from drinking water treatment in order to valorise them. In the first experimental stage, sludges were collected from a drinking water treatment plant for characterization. In the second stage, trials were carried out to elaborate thin cross-section specimens and fired bricks following an orthogonal central composite design of experiments with three factors (sludge composition, grain size and firing temperature) and five levels. The optimization parameters (Y(1)=shrinking by firing (%), Y(2)=water absorption (%), Y(3)=density (g/cm(3)) and Y(4)=compressive strength (kg/cm(2))) were determined according to standardized analytical methods. Two distinct physicochemical processes were active during firing at different conditions in the experimental design, preventing the determination of a full response surface, which would allow direct optimization of production parameters. Nevertheless, the temperature range for the production of classical red brick was closely delimitated by the results; above this temperature, a lightweight ceramic with surprisingly high strength was produced, opening possibilities for the valorisation of a product with considerably higher added value than what was originally envisioned.

Surface processing: existing and potential applications of ultraviolet light.

PubMed

Manzocco, Lara; Nicoli, Maria Cristina

2015-01-01

Solid foods represent optimal matrices for ultraviolet processing with effects well beyond nonthermal surface disinfection. UV radiation favors hormetic response in plant tissues and degradation of toxic compound on the product surface. Photoinduced reactions can also provide unexplored possibilities to steer structure and functionality of food biopolymers. The possibility to extensively exploit this technology will depend on availability of robust information about efficacious processing conditions and adequate strategies to completely and homogeneously process food surface.

The role of surface charge density in cationic liposome-promoted dendritic cell maturation and vaccine-induced immune responses

NASA Astrophysics Data System (ADS)

Ma, Yifan; Zhuang, Yan; Xie, Xiaofang; Wang, Ce; Wang, Fei; Zhou, Dongmei; Zeng, Jianqiang; Cai, Lintao

2011-05-01

Cationic liposomes have emerged as a novel adjuvant and antigen delivery system to enhance vaccine efficacy. However, the role of surface charge density in cationic liposome-regulated immune responses has not yet been elucidated. In the present study, we prepared a series of DOTAP/DOPC cationic liposomes with different surface densities by incorporating varying amounts of DOPC (a neutral lipid) into DOTAP (a cationic lipid). The results showed that DOTAP/DOPC cationic liposome-regulated immune responses relied on the surface charge density, and might occur through ROS signaling. The liposomes with a relatively high charge density, such as DOTAP/DOPC 5 : 0 and 4 : 1 liposomes, potently enhanced dendritic cell maturation, ROS generaion, antigen uptake, as well as the production of OVA-specific IgG2a and IFN-γ. In contrast, low-charge liposomes, such as DOTAP/DOPC 1 : 4 liposome, failed to promote immune responses even at high concentrations, confirming that the immunoregulatory effect of cationic liposomes is mostly attributable to their surface charge density. Moreover, the DOTAP/DOPC 1 : 4 liposome suppressed anti-OVA antibody responses in vivo. Overall, maintaining an appropriate surface charge is crucial for optimizing the adjuvant effect of cationic liposomes and enhancing the efficacy of liposome-based vaccines.

Uncertainty Quantification for CO2-Enhanced Oil Recovery

NASA Astrophysics Data System (ADS)

Dai, Z.; Middleton, R.; Bauman, J.; Viswanathan, H.; Fessenden-Rahn, J.; Pawar, R.; Lee, S.

2013-12-01

CO2-Enhanced Oil Recovery (EOR) is currently an option for permanently sequestering CO2 in oil reservoirs while increasing oil/gas productions economically. In this study we have developed a framework for understanding CO2 storage potential within an EOR-sequestration environment at the Farnsworth Unit of the Anadarko Basin in northern Texas. By coupling a EOR tool--SENSOR (CEI, 2011) with a uncertainty quantification tool PSUADE (Tong, 2011), we conduct an integrated Monte Carlo simulation of water, oil/gas components and CO2 flow and reactive transport in the heterogeneous Morrow formation to identify the key controlling processes and optimal parameters for CO2 sequestration and EOR. A global sensitivity and response surface analysis are conducted with PSUADE to build numerically the relationship among CO2 injectivity, oil/gas production, reservoir parameters and distance between injection and production wells. The results indicate that the reservoir permeability and porosity are the key parameters to control the CO2 injection, oil and gas (CH4) recovery rates. The distance between the injection and production wells has large impact on oil and gas recovery and net CO2 injection rates. The CO2 injectivity increases with the increasing reservoir permeability and porosity. The distance between injection and production wells is the key parameter for designing an EOR pattern (such as a five (or nine)-spot pattern). The optimal distance for a five-spot-pattern EOR in this site is estimated from the response surface analysis to be around 400 meters. Next, we are building the machinery into our risk assessment framework CO2-PENS to utilize these response surfaces and evaluate the operation risk for CO2 sequestration and EOR at this site.

Optimization of antifungal production by an alkaliphilic and halotolerant actinomycete, Streptomyces sp. SY-BS5, using response surface methodology.

PubMed

Souagui, Y; Tritsch, D; Grosdemange-Billiard, C; Kecha, M

2015-06-01

Optimization of medium components and physicochemical parameters for antifungal production by an alkaliphilic and salt-tolerant actinomycete designated Streptomyces sp. SY-BS5; isolated from an arid region in south of Algeria. The strain showed broad-spectrum activity against pathogenic and toxinogenic fungi. Identification of the actinomycete strain was realized on the basis of 16S rRNA gene sequencing. Antifungal production was optimized following one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. The most suitable medium for growth and antifungal production was found using one-factor-at-a-time methodology. The individual and interaction effects of three nutritional variables, carbon source (glucose), nitrogen source (yeast extract) and sodium chloride (NaCl) were optimized by Box-Behnken design. Finally, culture conditions for the antifungal production, pH and temperature were studied and determined. Analysis of the 16S rRNA gene sequence (1454 nucleotides) assigned this strain to Streptomyces genus with 99% similarity with Streptomyces cyaneofuscatus JCM4364(T), the most closely related. The results of the optimization study show that concentrations 3.476g/L of glucose, 3.876g/L of yeast extract and 41.140g/L of NaCl are responsible for the enhancement of antifungal production by Streptomyces sp. SY-BS5. The preferable culture conditions for antifungal production were pH 10, temperature 30°C for 09 days. This study proved that RSM is usual and powerful tool for the optimization of antifungal production from actinomycetes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

ERIC Educational Resources Information Center

Sivasankar, Mahalakshmi; Fisher, Kimberly V.

2007-01-01

Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

Optimization of Medium Using Response Surface Methodology for Lipid Production by Scenedesmus sp.

PubMed Central

Yang, Fangfang; Long, Lijuan; Sun, Xiumei; Wu, Hualian; Li, Tao; Xiang, Wenzhou

2014-01-01

Lipid production is an important indicator for assessing microalgal species for biodiesel production. In this work, the effects of medium composition on lipid production by Scenedesmus sp. were investigated using the response surface methodology. The results of a Plackett–Burman design experiment revealed that NaHCO3, NaH2PO4·2H2O and NaNO3 were three factors significantly influencing lipid production, which were further optimized by a Box–Behnken design. The optimal medium was found to contain 3.07 g L−1 NaHCO3, 15.49 mg L−1 NaH2PO4·2H2O and 803.21 mg L−1 NaNO3. Using the optimal conditions previously determined, the lipid production (304.02 mg·L−1) increased 54.64% more than that using the initial medium, which agreed well with the predicted value 309.50 mg L−1. Additionally, lipid analysis found that palmitic acid (C16:0) and oleic acid (C18:1) dominantly constituted the algal fatty acids (about 60% of the total fatty acids) and a much higher content of neutral lipid accounted for 82.32% of total lipids, which strongly proved that Scenedesmus sp. is a very promising feedstock for biodiesel production. PMID:24663113

Multi Response Optimization of Laser Micro Marking Process:A Grey- Fuzzy Approach

NASA Astrophysics Data System (ADS)

Shivakoti, I.; Das, P. P.; Kibria, G.; Pradhan, B. B.; Mustafa, Z.; Ghadai, R. K.

2017-07-01

The selection of optimal parametric combination for efficient machining has always become a challenging issue for the manufacturing researcher. The optimal parametric combination always provides a better machining which improves the productivity, product quality and subsequently reduces the production cost and time. The paper presents the hybrid approach of Grey relational analysis and Fuzzy logic to obtain the optimal parametric combination for better laser beam micro marking on the Gallium Nitride (GaN) work material. The response surface methodology has been implemented for design of experiment considering three parameters with their five levels. The parameter such as current, frequency and scanning speed has been considered and the mark width, mark depth and mark intensity has been considered as the process response.

Optimization of Culture Conditions for Enhanced Growth, Lipid and Docosahexaenoic Acid (DHA) Production of Aurantiochytrium SW1 by Response Surface Methodology.

PubMed

Nazir, Yusuf; Shuib, Shuwahida; Kalil, Mohd Sahaid; Song, Yuanda; Hamid, Aidil Abdul

2018-06-11

In this study, optimization of growth, lipid and DHA production of Aurantiochytrium SW1 was carried out using response surface methodology (RSM) in optimizing initial fructose concentration, agitation speed and monosodium glutamate (MSG) concentration. Central composite design was applied as the experimental design and analysis of variance (ANOVA) was used to analyze the data. ANOVA analysis revealed that the process which adequately represented by quadratic model was significant (p < 0.0001) for all the response. All the three factors were significant (p < 0.005) in influencing the biomass and lipid data while only two factors (agitation speed and MSG) gave significant effect on DHA production (p < 0.005). The estimated optimal conditions for enhanced growth, lipid and DHA production were 70 g/L fructose, 250 rpm agitation speed and 10 g/L MSG. Consequently, the quadratic model was validated by applying the estimated optimum conditions, which confirmed the model validity where 19.0 g/L biomass, 9.13 g/L lipid and 4.75 g/L of DHA were produced. The growth, lipid and DHA were 28, 36 and 35% respectively higher than that produced in the original medium prior to optimization.

Employing response surface methodology (RSM) to improve methane production from cotton stalk.

PubMed

Zhang, Han; Khalid, Habiba; Li, Wanwu; He, Yanfeng; Liu, Guangqing; Chen, Chang

2018-03-01

China is the largest cotton producer with the cotton output accounting for 25% of the total world's cotton production. A large quantity of cotton stalk (CS) waste is generated which is burned and causes environmental and ecological problems. This study investigated the anaerobic digestibility of CS by focusing on improving the methane yield by applying central composite design of response surface methodology (RSM). The purpose of this study was to determine the best level of factors to optimize the desired output of methane production from CS. Thus, it was necessary to describe the relationship of many individual variables with one or more response values for the effective utilization of CS. The influences of feed to inoculum (F/I) ratio and organic loading (OL) on methane production were investigated. Results showed that the experimental methane yield (EMY) and volatile solid (VS) removal were calculated to be 70.22 mL/gVS and 14.33% at F/I ratio of 0.79 and organic loading of 25.61 gVS/L, respectively. Characteristics of final effluent showed that the anaerobic system was stable. This research laid a foundation for future application of CS to alleviate the problems of waste pollution and energy output.

Heterotrophic bacterioplankton in the Arabian Sea:. Basinwide response to year-round high primary productivity

NASA Astrophysics Data System (ADS)

Ducklow, H. W.; Smith, D. C.; Campbell, L.; Landry, M. R.; Quinby, H. L.; Steward, G. F.; Azam, F.

Heterotrophic bacterial abundance and productivity were measured during five and four cruises, respectively, in the northwest Arabian Sea as part of the US JGOFS Process Study, which provided a new view of seasonal bacterial dynamics in that part of the basin influenced by monsoonal forcing. In this paper, surface layer data are used to address two questions concerning the influence of the monsoon cycle on bacterial dynamics: (1) Is there a bacterial bloom in the SW Monsoon? and (2) Is bacterial production low during the oligotrophic Spring Intermonsoon? An extensive comparison of epifluorescence microscopy and flow cytometry, unprecedented at this scale, detected essentially the same heterotrophic bacterial populations and distributions, with some between-cruise differences. Use of the two methods allowed us to extend our observations in space and time. Bacterial productivity, both in the surface layer and integrated over the euphotic zone, was elevated less than 2-fold during the Southwest Monsoon. Levels of bacterial abundance and production were low during the Northeast Monsoon, then increased in March during the Spring Intermonsoon. There was some stimulation of abundance or production inshore in response to coastal upwelling. In general, the basin was enriched in bacterial biomass >5×10 8 cells l -1 throughout the year, relative to other tropical regimes, presumably in response to overall high PP and DOC levels. Seasonally uniform DOC levels may be regulated in part by intense bacterial utilization rates, but also reflect seasonal consistency in PP.

Evaluation of prethroid insecticides and insect growth regulators applied to different surfaces for control of Trogoderma granarium Everts the khapra beetle

USDA-ARS?s Scientific Manuscript database

The khapra beetle, Trogoderma granarium Everts, is a serious pest of stored products and is the only stored products pest that triggers a quarantine response when it is found in the United States. The larvae of T. granarium feed on a wide range of dry food products of plant and animal origin includi...

Copper effects on bacterial activity of estuarine silty sediments

NASA Astrophysics Data System (ADS)

Almeida, Adelaide; Cunha, Ângela; Fernandes, Sandra; Sobral, Paula; Alcântara, Fernanda

2007-07-01

Bacteria of silty estuarine sediments were spiked with copper to 200 μg Cu g -1 dry weight sediment in order to assess the impact of copper on bacterial degradation of organic matter and on bacterial biomass production. Bacterial density was determined by direct counting under epifluorescence microscopy and bacterial production by the incorporation of 3H-Leucine. Leucine turnover rate was evaluated by 14C-leucine incorporation and ectoenzymatic activities were estimated as the hydrolysis rate of model substrates for β-glucosidase and leucine-aminopeptidase. The presence of added copper in the microcosms elicited, after 21 days of incubation, generalised anoxia and a decrease in organic matter content. The non-eroded surface of the copper-spiked sediment showed, when compared to the control, a decrease in bacterial abundance and significant lower levels of bacterial production and of leucine turnover rate. Bacterial production and leucine turnover rate decreased to 1.4% and 13% of the control values, respectively. Ectoenzymatic activities were also negatively affected but by smaller factors. After erosion by the water current in laboratory flume conditions, the eroded surface of the control sediment showed a generalised decline in all bacterial activities. The erosion of the copper-spiked sediment showed, however, two types of responses with respect to bacterial activities at the exposed surface: positive responses of bacterial production and leucine turnover rate contrasting with slight negative responses of ectoenzymatic activities. The effects of experimental erosion in the suspended cells were also different in the control and in the copper-spiked sediment. Bacterial cells in the control microcosm exhibited, when compared to the non-eroded sediment cells, decreases in all activities after the 6-h suspension. The response of the average suspended copper-spiked sediment cell differed from the control by a less sharp decrease in ectoenzymatic activities and, mainly, by the great intensification of bacterial biomass production and leucine turnover rate. We conclude that the bacterial community of silty estuarine sediments seems to withstand considerable concentrations of copper at the cost of reduced bacterial organic matter degradation and of the almost halting of bacterial production. The toxic effects elicited by copper on protein and carbohydrate degradation were not rapidly repaired by erosion and oxygenation of the sediment cells but, in contrast, bacterial biomass production and leucine turnover were rapidly and efficiently reactivated.

Evaluating the influence of process parameters on soluble microbial products formation using response surface methodology coupled with grey relational analysis.

PubMed

Xu, Juan; Sheng, Guo-Ping; Luo, Hong-Wei; Fang, Fang; Li, Wen-Wei; Zeng, Raymond J; Tong, Zhong-Hua; Yu, Han-Qing

2011-01-01

Soluble microbial products (SMPs) present a major part of residual chemical oxygen demand (COD) in the effluents from biological wastewater treatment systems, and the SMP formation is greatly influenced by a variety of process parameters. In this study, response surface methodology (RSM) coupled with grey relational analysis (GRA) method was used to evaluate the effects of substrate concentration, temperature, NH(4)(+)-N concentration and aeration rate on the SMP production in batch activated sludge reactors. Carbohydrates were found to be the major component of SMP, and the influential priorities of these factors were: temperature>substrate concentration > aeration rate > NH(4)(+)-N concentration. On the basis of the RSM results, the interactive effects of these factors on the SMP formation were evaluated, and the optimal operating conditions for a minimum SMP production in such a batch activated sludge system also were identified. These results provide useful information about how to control the SMP formation of activated sludge and ensure the bioreactor high-quality effluent. Copyright © 2010 Elsevier Ltd. All rights reserved.

Optimization of Submerged Fermentation Medium for Matrine Production by Aspergillus terreus, an Endophytic Fungus Harboring Seeds of Sophora flavescens, Using Response Surface Methodology

PubMed Central

Zhang, Qiang; Li, Yujuan; Xu, Fangxue; Zheng, Mengmeng; Xi, Xiaozhi

2017-01-01

Different endophytes isolated from the seeds of Sophora flavescens were tested for their ability to produce matrine production. Response surface methodology (RSM) was applied to optimize the medium components for the endophytic fungus. Results indicated that endophyte Aspergillus terreus had the ability to produce matrine. The single factor tests demonstrated that potato starch was the best carbon source and the combination of peptone and NH4NO3 was the optimal nitrogen source for A. terreus. The model of RSM predicted to gain the maximal matrine production at 20.67 µg/L, when the potato starch was 160.68 g/L, peptone was 24.96 g/L and NH4NO3 was 2.11 g/L. When cultured in the optimal medium, the matrine yield was an average of 20.63 ± 0.11 µg/L, which was consistent with the model prediction. This study offered an alternative source for the matrine production by endophytic fungus fermentation and may have far-reaching prospect and value. PMID:28781541

Optimization of Submerged Fermentation Medium for Matrine Production by Aspergillus terreus, an Endophytic Fungus Harboring Seeds of Sophora flavescens, Using Response Surface Methodology.

PubMed

Zhang, Qiang; Li, Yujuan; Xu, Fangxue; Zheng, Mengmeng; Xi, Xiaozhi; Zhang, Xuelan; Han, Chunchao

2017-06-01

Different endophytes isolated from the seeds of Sophora flavescens were tested for their ability to produce matrine production. Response surface methodology (RSM) was applied to optimize the medium components for the endophytic fungus. Results indicated that endophyte Aspergillus terreus had the ability to produce matrine. The single factor tests demonstrated that potato starch was the best carbon source and the combination of peptone and NH 4 NO 3 was the optimal nitrogen source for A. terreus . The model of RSM predicted to gain the maximal matrine production at 20.67 µg/L, when the potato starch was 160.68 g/L, peptone was 24.96 g/L and NH 4 NO 3 was 2.11 g/L. When cultured in the optimal medium, the matrine yield was an average of 20.63 ± 0.11 µg/L, which was consistent with the model prediction. This study offered an alternative source for the matrine production by endophytic fungus fermentation and may have far-reaching prospect and value.

Medium optimization by orthogonal array and response surface methodology for cholesterol oxidase production by Streptomyces lavendulae NCIM 2499.

PubMed

Chauhan, Awadesh K; Survase, Shrikant A; Kishenkumar, Jyoti; Annapure, Uday S

2009-06-01

This paper deals with the optimization of culture conditions for the production of cholesterol oxidase (COD) by Streptomyces lavendulae NCIM 2499 using the one-factor-at-a-time method, orthogonal array method and response surface methodology (RSM) approaches. The one-factor-at-a-time method was adopted to investigate the effects of medium components (i.e. carbon and nitrogen) and environmental factors (i.e. initial pH) on biomass growth and COD production. Subsequently, an L12 orthogonal matrix was used to evaluate the significance of glycerol, soyabean meal, malt extract, K2HPO4, MgSO4 and NaCl. The effects of media components were ranked according to their effects on the production of COD as malt extract > soyabean meal > K2HPO4 > NaCl > MgSO4 > glycerol. The subsequent optimization of the four most significant factors viz. malt extract, soyabean meal, K2HPO4 and NaCl, was carried out by employing a central composite rotatable design (CCRD) of RSM. There was a 2.48-fold increase in productivity of COD as compared to the unoptimized media by using these statistical approaches.

Rapid Aluminum Nanoparticle Production by Milling in NH₃ and CH₃NH₂ Atmospheres: An Experimental and Theoretical Study.

PubMed

McMahon, Brandon W; Yu, Jiang; Boatz, Jerry A; Anderson, Scott L

2015-07-29

Ball milling of aluminum in gaseous atmospheres of ammonia and monomethylamine (MMA) was found to produce particles in the 100 nm size range with high efficiency. A combination of mass spectrometry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis with mass spectrometric product analysis (TGA-MS), scanning electron microscopy (SEM), infrared spectroscopy, and dynamic light scattering (DLS) was used to study the particles and the chemical interactions responsible for particle production. To help understand the nature of the surface chemistry, high level quantum chemical calculations were performed to predict the structures and energetics for binding and reactions of NH3 and MMA on aluminum surfaces. Both NH3 and MMA react with aluminum under milling conditions, producing H2 and other gaseous products, and leaving the surfaces functionalized. The surface functionalization enhances size reduction by reducing the surface free energy and the tendency toward mechanochemical welding. For both NH3 and MMA, the particle cores are metallic aluminum, but the surface chemical properties are quite different. The ammonia-milled particles are capped by an AlNxOyHz layer ∼10 nm thick, which passivates the particles. The MMA-milled particles are capped with a thinner passivating layer, such that they are pyrophoric in air and react with N2 at elevated temperatures.

Application of Response Surface Methodology on Leaching of Iron from Partially Laterised Khondalite Rocks: A Bauxite Mining Waste

NASA Astrophysics Data System (ADS)

Swain, Ranjita; Bhima Rao, R.

2018-04-01

In the present investigation, response surface methodology (RSM) is used for a quadratic model that continuously controls the process parameters. This model is used to optimize the removal of iron oxide from Partially Laterised Khondalite (PLK) rocks which is influenced by several independent variables namely acid concentration, time and temperature. Second order response functions are produced for leaching of iron oxide from PLK rocks-a bauxite mining waste. In RSM, Box-Behnken design is used for the process optimization to achieve maximum removal of iron oxide. The influence of the process variables of leaching of iron oxide is presented in the form of 3-D response graphs. The results of this investigation reveals that 3 M hydrochloric acid concentration, 240 min time and 373 K temperature are found to be the best conditions for removal of 99% Fe2O3. The product obtain at this condition contain 80% brightness which is suitable for ceramic and filler industry applications. The novelity of the work is that the waste can be a value added product after suitable physical beneficiation and chemical treatment.

Warpage analysis on thin shell part using response surface methodology (RSM)

NASA Astrophysics Data System (ADS)

Zulhasif, Z.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

2017-09-01

The optimisation of moulding parameters appropriate to reduce warpage defects produce using Autodesk Moldflow Insight (AMI) 2012 software The product is injected by using Acrylonitrile-Butadiene-Styrene (ABS) materials. This analysis has processing parameter that varies in melting temperature, mould temperature, packing pressure and packing time. Design of Experiments (DOE) has been integrated to obtain a polynomial model using Response Surface Methodology (RSM). The Glowworm Swarm Optimisation (GSO) method is used to predict a best combination parameters to minimise warpage defect in order to produce high quality parts.

Solar Irradiance Changes and Phytoplankton Productivity in Earth's Ocean Following Astrophysical Ionizing Radiation Events.

PubMed

Neale, Patrick J; Thomas, Brian C

2016-04-01

Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are production of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran productivity focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the ocean (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted productivity declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of productivity responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and productivity are low.

Optimization of a natural medium for cellulase by a marine Aspergillus niger using response surface methodology.

PubMed

Xue, Dong-Sheng; Chen, Hui-Yin; Lin, Dong-Qiang; Guan, Yi-Xin; Yao, Shan-Jing

2012-08-01

The components of a natural medium were optimized to produce cellulase from a marine Aspergillus niger under solid state fermentation conditions by response surface methodology. Eichhornia crassipes and natural seawater were used as a major substrate and a source of mineral salts, respectively. Mineral salts of natural seawater could increase cellulase production. Raw corn cob and raw rice straw showed a significant positive effect on cellulase production. The optimum natural medium consisted of 76.9 % E. crassipes (w/w), 8.9 % raw corn cob (w/w), 3.5 % raw rice straw (w/w), 10.7 % raw wheat bran (w/w), and natural seawater (2.33 times the weight of the dry substrates). Incubation for 96 h in the natural medium increased the biomass to the maximum. The cellulase production was 17.80 U/g the dry weight of substrates after incubation for 144 h. The natural medium avoided supplying chemicals and pretreating substrates. It is promising for future practical fermentation of environment-friendly producing cellulase.

Modeling and investigation of submerged fermentation process to produce extracellular polysaccharide using Lactobacillus confusus.

PubMed

Thirugnanasambandham, K; Sivakumar, V; Prakash Maran, J

2014-12-19

The main objective of the present study is to investigate and optimize the Submerged fermentation (SMF) process parameters such as addition of coconut water, NaCl dose, incubation time and temperature on the production of extracellular polysaccharide (EPS) and biomass production using Lactobacillus confuses. Response surface methodology (RSM) coupled with four factors three level Box-Behnken design (BBD) was employed to model the SMF process. RSM analysis indicated good correspondence between experimental and predicted values. Three dimentional (3D) response surface plots were used to study the interactive effects of process variables on SMF process. The optimum process conditions for the maximum production of EPS and biomass were found to be as follows; addition of coconut water of 40%, NaCl dose of 15%, incubation time of 24h and temperature of 35°C. Under these conditions, 10.57 g/L of EPS and 3.9 g/L of biomass were produced. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of conditions for probiotic curd formulation by Enterococcus faecium MTCC 5695 with probiotic properties using response surface methodology.

PubMed

Ramakrishnan, Vrinda; Goveas, Louella Concepta; Prakash, Maya; Halami, Prakash M; Narayan, Bhaskar

2014-11-01

Enterococcus faecium MTCC 5695 possessing potential probiotic properties as well as enterocin producing ability was used as starter culture. Effect of time (12-24 h) and inoculum level (3-7 % v/v) on cell growth, bacteriocin production, antioxidant property, titrable acidity and pH of curd was studied by response surface methodology (RSM). The optimized conditions were 26.48 h and 2.17%v/v inoculum and the second order model validated. Co cultivation studies revealed that the formulated product had the ability to prevent growth of foodborne pathogens that affect keeping quality of the product during storage. The results indicated that application of E. faecium MTCC 5695 along with usage of optimized conditions attributed to the formation of highly consistent well set curd with bioactive and bioprotective properties. Formulated curd with potential probiotic attributes can be used as therapeutic agent for the treatment of foodborne diseases like Traveler's diarrhea and gastroenteritis which thereby help in improvement of bowel health.

Optimization of Manganese Reduction in Biotreated POME onto 3A Molecular Sieve and Clinoptilolite Zeolites.

PubMed

Jami, Mohammed S; Rosli, Nurul-Shafiqah; Amosa, Mutiu K

2016-06-01

Availability of quality-certified water is pertinent to the production of food and pharmaceutical products. Adverse effects of manganese content of water on the corrosion of vessels and reactors necessitate that process water is scrutinized for allowable concentration levels before being applied in the production processes. In this research, optimization of the adsorption process conditions germane to the removal of manganese from biotreated palm oil mill effluent (BPOME) using zeolite 3A subsequent to a comparative adsorption with clinoptilolite was studied. A face-centered central composite design (FCCCD) of the response surface methodology (RSM) was adopted for the study. Analysis of variance (ANOVA) for response surface quadratic model revealed that the model was significant with dosage and agitation speed connoting the main significant process factors for the optimization. R(2) of 0.9478 yielded by the model was in agreement with predicted R(2). Langmuir and pseudo-second-order suggest the adsorption mechanism involved monolayer adsorption and cation exchanging.

Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology.

PubMed

Yu, Hyung-Seok; Lee, Na-Kyoung; Jeon, Hye-Lin; Eom, Su Jin; Yoo, Mi-Young; Lim, Sang-Dong; Paik, Hyun-Dong

2016-01-01

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology

PubMed Central

Yoo, Mi-Young; Lim, Sang-Dong

2016-01-01

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products. PMID:27433115

Optimization of critical medium components using response surface methodology for biomass and extracellular polysaccharide production by Agaricus blazei.

PubMed

Liu, Gao-Qiang; Wang, Xiao-Ling

2007-02-01

Response surface methodology (RSM) was applied to optimize the critical medium ingredients of Agaricus blazei. A three-level Box-Behnken factorial design was employed to determine the maximum biomass and extracellular polysaccharide (EPS) yields at optimum levels for glucose, yeast extract (YE), and peptone. A mathematical model was then developed to show the effect of each medium composition and its interactions on the production of mycelial biomass and EPS. The model predicted the maximum biomass yield of 10.86 g/l that appeared at glucose, YE, peptone of 26.3, 6.84, and 6.62 g/l, respectively, while a maximum EPS yield of 348.4 mg/l appeared at glucose, YE, peptone of 28.4, 4.96, 5.60 g/l, respectively. These predicted values were also verified by validation experiments. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The results of bioreactor fermentation also show that the optimized culture medium enhanced both biomass (13.91 +/- 0.71 g/l) and EPS (363 +/- 4.1 mg/l) production by Agaricus blazei in a large-scale fermentation process.

Modelling and Optimization of Polycaprolactone Ultrafine-Fibres Electrospinning Process Using Response Surface Methodology

PubMed Central

Ruys, Andrew J.

2018-01-01

Electrospun fibres have gained broad interest in biomedical applications, including tissue engineering scaffolds, due to their potential in mimicking extracellular matrix and producing structures favourable for cell and tissue growth. The development of scaffolds often involves multivariate production parameters and multiple output characteristics to define product quality. In this study on electrospinning of polycaprolactone (PCL), response surface methodology (RSM) was applied to investigate the determining parameters and find optimal settings to achieve the desired properties of fibrous scaffold for acetabular labrum implant. The results showed that solution concentration influenced fibre diameter, while elastic modulus was determined by solution concentration, flow rate, temperature, collector rotation speed, and interaction between concentration and temperature. Relationships between these variables and outputs were modelled, followed by an optimization procedure. Using the optimized setting (solution concentration of 10% w/v, flow rate of 4.5 mL/h, temperature of 45 °C, and collector rotation speed of 1500 RPM), a target elastic modulus of 25 MPa could be achieved at a minimum possible fibre diameter (1.39 ± 0.20 µm). This work demonstrated that multivariate factors of production parameters and multiple responses can be investigated, modelled, and optimized using RSM. PMID:29562614

Development of gluten-free fish (Pseudoplatystoma corruscans) patties by response surface methodology.

PubMed

Romero, Mara C; Fogar, Ricardo A; Rolhaiser, Fabiana; Clavero, Verónica V; Romero, Ana M; Judis, María A

2018-05-01

The goal of this study was to develop a fish-based product suitable for people with celiac disease. Water and gluten-free flours (rice, corn, amaranth or quinoa) were added to improve cooking yield, texture parameters and as an aid in improving quality attributes such as taste and juiciness. Cooking yields of patties containing gluten-free flours were higher than control and maximum values ranged between 91 and 93%. Hardness was higher in patties made with amaranth or quinoa flour, whereas cohesiveness and springiness were higher in patties made with corn and rice flour, respectively. Response surface methodology was used to optimize patties formulations. Optimized formulations were prepared and evaluated showing a good agreement between predicted and experimental responses. Also, nutritional value and consumer acceptance of optimized formulations were analysed. Flours addition affected proximate composition increasing carbohydrates, total fat and mineral content compared to control. Sensory evaluation showed that no differences were found in the aroma of products. Addition of rice flour increased juiciness and tenderness whereas taste, overall acceptance and buying intention were higher in control patty, followed by patties made with corn flour. The present investigation shows good possibilities for further product development, including the scale up at an industrial level.

Nonlinear, interacting responses to climate limit grassland production under global change.

PubMed

Zhu, Kai; Chiariello, Nona R; Tobeck, Todd; Fukami, Tadashi; Field, Christopher B

2016-09-20

Global changes in climate, atmospheric composition, and pollutants are altering ecosystems and the goods and services they provide. Among approaches for predicting ecosystem responses, long-term observations and manipulative experiments can be powerful approaches for resolving single-factor and interactive effects of global changes on key metrics such as net primary production (NPP). Here we combine both approaches, developing multidimensional response surfaces for NPP based on the longest-running, best-replicated, most-multifactor global-change experiment at the ecosystem scale-a 17-y study of California grassland exposed to full-factorial warming, added precipitation, elevated CO2, and nitrogen deposition. Single-factor and interactive effects were not time-dependent, enabling us to analyze each year as a separate realization of the experiment and extract NPP as a continuous function of global-change factors. We found a ridge-shaped response surface in which NPP is humped (unimodal) in response to temperature and precipitation when CO2 and nitrogen are ambient, with peak NPP rising under elevated CO2 or nitrogen but also shifting to lower temperatures. Our results suggest that future climate change will push this ecosystem away from conditions that maximize NPP, but with large year-to-year variability.

Bifidobacterial surface-exopolysaccharide facilitates commensal-host interaction through immune modulation and pathogen protection

PubMed Central

Fanning, Saranna; Hall, Lindsay J.; Cronin, Michelle; Zomer, Aldert; MacSharry, John; Goulding, David; O'Connell Motherway, Mary; Shanahan, Fergus; Nally, Kenneth; Dougan, Gordon; van Sinderen, Douwe

2012-01-01

Bifidobacteria comprise a significant proportion of the human gut microbiota. Several bifidobacterial strains are currently used as therapeutic interventions, claiming various health benefits by acting as probiotics. However, the precise mechanisms by which they maintain habitation within their host and consequently provide these benefits are not fully understood. Here we show that Bifidobacterium breve UCC2003 produces a cell surface-associated exopolysaccharide (EPS), the biosynthesis of which is directed by either half of a bidirectional gene cluster, thus leading to production of one of two possible EPSs. Alternate transcription of the two opposing halves of this cluster appears to be the result of promoter reorientation. Surface EPS provided stress tolerance and promoted in vivo persistence, but not initial colonization. Marked differences were observed in host immune response: strains producing surface EPS (EPS+) failed to elicit a strong immune response compared with EPS-deficient variants. Specifically, EPS production was shown to be linked to the evasion of adaptive B-cell responses. Furthermore, presence of EPS+ B. breve reduced colonization levels of the gut pathogen Citrobacter rodentium. Our data thus assigns a pivotal and beneficial role for EPS in modulating various aspects of bifidobacterial–host interaction, including the ability of commensal bacteria to remain immunologically silent and in turn provide pathogen protection. This finding enforces the probiotic concept and provides mechanistic insights into health-promoting benefits for both animal and human hosts. PMID:22308390

Optimization of a novel improver gel formulation for Barbari flat bread using response surface methodology.

PubMed

Pourfarzad, Amir; Haddad Khodaparast, Mohammad Hossein; Karimi, Mehdi; Mortazavi, Seyed Ali

2014-10-01

Nowadays, the use of bread improvers has become an essential part of improving the production methods and quality of bakery products. In the present study, the Response Surface Methodology (RSM) was used to determine the optimum improver gel formulation which gave the best quality, shelf life, sensory and image properties for Barbari flat bread. Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM) and propylene glycol (PG) were constituents of the gel and considered in this study. A second-order polynomial model was fitted to each response and the regression coefficients were determined using least square method. The optimum gel formulation was found to be 0.49 % of SSL, 0.36 % of DATEM and 0.5 % of PG when desirability function method was applied. There was a good agreement between the experimental data and their predicted counterparts. Results showed that the RSM, image processing and texture analysis are useful tools to investigate, approximate and predict a large number of bread properties.

Role of Complement on Broken Surfaces After Trauma.

PubMed

Huber-Lang, Markus; Ignatius, Anita; Brenner, Rolf E

2015-01-01

Activation of both the complement and coagulation cascade after trauma and subsequent local and systemic inflammatory response represent a major scientific and clinical problem. After severe tissue injury and bone fracture, exposure of innate immunity to damaged cells and molecular debris is considered a main trigger of the posttraumatic danger response. However, the effects of cellular fragments (e.g., histones) on complement activation remain enigmatic. Furthermore, direct effects of "broken" bone and cartilage surfaces on the fluid phase response of complement and its interaction with key cells of connective tissues are still unknown. Here, we summarize data suggesting direct and indirect complement activation by extracellular and cellular danger associated molecular patterns. In addition, key complement components and the corresponding receptors (such as C3aR, C5aR) have been detected on "exposed surfaces" of the damaged regions. On a cellular level, multiple effects of complement activation products on osteoblasts, osteoclasts, chondrocytes and mesenchymal stem cells have been found.In conclusion, the complement system may be activated by trauma-altered surfaces and is crucially involved in connective tissue healing and posttraumatic systemic inflammatory response.

Application of Response Surface Methodology for characterization of ozone production from Multi-Cylinder Reactor in non-thermal plasma device

NASA Astrophysics Data System (ADS)

Lian See, Tan; Zulazlan Shah Zulkifli, Ahmad; Mook Tzeng, Lim

2018-04-01

Ozone is a reactant which can be applied for various environmental treatment processes. It can be generated via atmospheric air non-thermal plasmas when sufficient voltages are applied through a combination of electrodes and dielectric materials. In this study, the concentration of ozone generated via two different configurations of multi-cylinder dielectric barrier discharge (DBD) reactor (3 x 40 mm and 10 x 10 mm) was investigated. The influence of the voltage and the duty cycle to the concentration of ozone generated by each configuration was analysed using response surface methodology. Voltage was identified as significant factor to the ozone production process. However, the regressed model was biased towards one of the configuration, leaving the predicted results of another configuration to be out of range.

Biodiesel production from castor oil using heterogeneous Ni doped ZnO nanocatalyst.

PubMed

Baskar, G; Aberna Ebenezer Selvakumari, I; Aiswarya, R

2018-02-01

In the present study, castor oil with high free fatty acid was used for biodiesel production using heterogeneous Ni doped ZnO nanocatalyst. Ni doped ZnO nanocomposite calcinated at 800 °C has shown better catalytic activity. Process parameters on heterogeneous catalysis of castor oil into biodiesel were optimized using conventional and Response Surface Methodology (RSM). RSM was found more accurate in estimating the optimum conditions with higher biodiesel yield (95.20%). The optimum conditions for transesterification was found to be oil to methanol molar ratio of 1:8, catalyst loading 11% (w/w), reaction temperature of 55 °C for 60 min of reaction time by response surface method. The reusability studies showed that the nanocatalyst can be reused efficiently for 3 cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of volatile fatty acid production with co-substrate of food wastes and dewatered excess sludge using response surface methodology.

PubMed

Hong, Chen; Haiyun, Wu

2010-07-01

Central-composite design (CCD) and response surface methodology (RSM) were used to optimize the parameters of volatile fatty acid (VFA) production from food wastes and dewatered excess sludge in a semi-continuous process. The effects of four variables (food wastes composition in the co-substrate of food wastes and excess sludge, hydraulic retention time (HRT), organic loading rate (OLR), and pH) on acidogenesis were evaluated individually and interactively. The optimum condition derived via RSM was food wastes composition, 88.03%; HRT, 8.92 days; OLR, 8.31 g VSS/ld; and pH 6.99. The experimental VFA concentration was 29,099 mg/l under this optimum condition, which was well in agreement with the predicted value of 28,000 mg/l. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Investigation of extractive microbial transformation in nonionic surfactant micelle aqueous solution using response surface methodology.

PubMed

Xue, Yingying; Qian, Chen; Wang, Zhilong; Xu, Jian-He; Yang, Rude; Qi, Hanshi

2010-01-01

Extractive microbial transformation of L-phenylacetylcarbinol (L-PAC) in nonionic surfactant Triton X-100 micelle aqueous solution was investigated by response surface methodology. Based on the Box-Behnken design, a mathematical model was developed for the predication of mutual interactions between benzaldehyde, Triton X-100, and glucose on L-PAC production. It indicated that the negative or positive effect of nonionic surfactant strongly depended on the substrate concentration. The model predicted that the optimal concentration of benzaldehyde, Triton X-100, and glucose was 1.2 ml, 15 g, and 2.76 g per 100 ml, respectively. Under the optimal condition, the maximum L-PAC production was 27.6 mM, which was verified by a time course of extractive microbial transformation. A discrete fed-batch process for verification of cell activity was also presented.

Partial oxidation of landfill leachate in supercritical water: Optimization by response surface methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, Yanmeng; Wang, Shuzhong; Xu, Haidong

Highlights: • Partial oxidation of landfill leachate in supercritical water was investigated. • The process was optimized by Box–Behnken design and response surface methodology. • GY{sub H2}, TRE and CR could exhibit up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56%. • Small amounts of oxidant can decrease the generation of tar and char. - Abstract: To achieve the maximum H{sub 2} yield (GY{sub H2}), TOC removal rate (TRE) and carbon recovery rate (CR), response surface methodology was applied to optimize the process parameters for supercritical water partial oxidation (SWPO) of landfill leachate in a batch reactor. Quadratic polynomial models formore » GY{sub H2}, CR and TRE were established with Box–Behnken design. GY{sub H2}, CR and TRE reached up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56% under optimum conditions, respectively. TRE was invariably above 91.87%. In contrast, TC removal rate (TR) only changed from 8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant carbonaceous substances in product, whereas CO{sub 2} and H{sub 2} were the most abundant gaseous products. As a product of nitrogen-containing organics, NH{sub 3} has an important effect on gas composition. The carbon balance cannot be reached duo to the formation of tar and char. CR increased with the increase of temperature and oxidation coefficient.« less

Cross-calibration of MODIS with ETM+ and ALI sensors for long-term monitoring of land surface processes

USGS Publications Warehouse

Meyer, D.; Chander, G.

2006-01-01

Increasingly, data from multiple sensors are used to gain a more complete understanding of land surface processes at a variety of scales. Although higher-level products (e.g., vegetation cover, albedo, surface temperature) derived from different sensors can be validated independently, the degree to which these sensors and their products can be compared to one another is vastly improved if their relative spectroradiometric responses are known. Most often, sensors are directly calibrated to diffuse solar irradiation or vicariously to ground targets. However, space-based targets are not traceable to metrological standards, and vicarious calibrations are expensive and provide a poor sampling of a sensor's full dynamic range. Crosscalibration of two sensors can augment these methods if certain conditions can be met: (1) the spectral responses are similar, (2) the observations are reasonably concurrent (similar atmospheric & solar illumination conditions), (3) errors due to misregistrations of inhomogeneous surfaces can be minimized (including scale differences), and (4) the viewing geometry is similar (or, some reasonable knowledge of surface bi-directional reflectance distribution functions is available). This study explores the impacts of cross-calibrating sensors when such conditions are met to some degree but not perfectly. In order to constrain the range of conditions at some level, the analysis is limited to sensors where cross-calibration studies have been conducted (Enhanced Thematic Mapper Plus (ETM+) on Landsat-7 (L7), Advance Land Imager (ALI) and Hyperion on Earth Observer-1 (EO-1)) and including systems having somewhat dissimilar geometry, spatial resolution & spectral response characteristics but are still part of the so-called "A.M. constellation" (Moderate Resolution Imaging Spectrometer (MODIS) aboard the Terra platform). Measures for spectral response differences and methods for cross calibrating such sensors are provided in this study. These instruments are cross calibrated using the Railroad Valley playa in Nevada. Best fit linear coefficients (slope and offset) are provided for ALI-to-MODIS and ETM+-to-MODIS cross calibrations, and root-mean-squared errors (RMSEs) and correlation coefficients are provided to quantify the uncertainty in these relationships. In theory, the linear fits and uncertainties can be used to compare radiance and reflectance products derived from each instrument.

Isolation of dihydroatemisinic acid from the artemisia annua l. by-product by combining Ultrasound-assisted extraction with response surface methodology

USDA-ARS?s Scientific Manuscript database

Malaria is one of the world’s most important parasitic diseases, affecting 300-500 million people worldwide and killing more than one million per year. Artemisinin is currently the only raw material for the production of artemisinin combination therapies (ACT), the only medicine that cures drug-resi...

Simulated and measured water levels and estimated water-level changes in the Albuquerque area, central New Mexico, 1950-2012

USGS Publications Warehouse

Rice, Steven E.; Oelsner, Gretchen P.; Heywood, Charles E.

2014-01-01

and again for 2008. Both the water-table elevations and production-zone hydraulic heads declined over time with the largest change occurring between 1970 and 1980, which was a period of rapid population growth and groundwater use. Declines in the water-table elevations and production-zone hydraulic heads are focused around major pumping centers and are largest in the production zone. Hydrographs from nine production-zone piezometers in the modeled area indicated varying responses to the increased use of surface-water diversions during 2009–12, with responses related to the locations of the wells within the study area and their proximity to pumping centers and the Rio Grande.

Proceedings of Office of Surface Mining Coal Combustion By-product Government/Regulatory Panel: University of Kentucky international ash utilization symposium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vories, K.C.

2003-07-01

Short papers are given on: the Coal Combustion Program (C2P2) (J. Glenn); regional environmental concerns with disposal of coal combustion wastes at mines (T. FitzGerald); power plant waste mine filling - an environmental perspective (L.G. Evans); utility industry perspective regarding coal combustion product management and regulation (J. Roewer); coal combustion products opportunities for beneficial use (D.C. Goss); state perspective on mine placement of coal combustion by-products (G.E. Conrad); Texas regulations provide for beneficial use of coal combustion ash (S.S. Ferguson); and the Surface Mining Control and Reclamation Act - a response to concerns about placement of CCBs at coal minemore » sites (K.C. Vories). The questions and answers are also included.« less

Surface Structure Characterization of Aspergillus fumigatus Conidia Mutated in the Melanin Synthesis Pathway and Their Human Cellular Immune Response

PubMed Central

Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F.; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A.; Kaveri, Srini V.; Kwon-Chung, Kyung J.

2014-01-01

In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface. PMID:24818666

Analysis of silver nanoparticles in antimicrobial products using surface-enhanced Raman spectroscopy (SERS).

PubMed

Guo, Huiyuan; Zhang, Zhiyun; Xing, Baoshan; Mukherjee, Arnab; Musante, Craig; White, Jason C; He, Lili

2015-04-07

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles in consumer products. Concerns over human exposure to and risk from these particles have resulted in increased interest in novel strategies to detect AgNPs. This study investigated the feasibility of surface-enhanced Raman spectroscopy (SERS) as a method for the detection and quantification of AgNPs in antimicrobial products. By using ferbam (ferric dimethyl-dithiocarbamate) as an indicator molecule that binds strongly onto the nanoparticles, AgNPs detection and discrimination were achieved based on the signature SERS response of AgNPs-ferbam complexes. SERS response with ferbam was distinct for silver ions, silver chloride, silver bulk particles, and AgNPs. Two types of AgNPs with different coatings, citrate and polyvinylpirrolidone (PVP), both showed strong interactions with ferbam and induced strong SERS signals. SERS was effectively applicable for detecting Ag particles ranging from 20 to 200 nm, with the highest signal intensity in the 60-100 nm range. A linear relationship (R(2) = 0.9804) between Raman intensity and citrate-AgNPs concentrations (60 nm; 0-20 mg/L) indicates the potential for particle quantification. We also evaluated SERS detection of AgNPs in four commercially available antimicrobial products. Combined with ICP-MS and TEM data, the results indicated that the SERS response is primarily dependent on size, but also affected by AgNPs concentration. The findings demonstrate that SERS is a promising analytical platform for studying environmentally relevant levels of AgNPs in consumer products and related matrices.

Physicochemical properties of crystalline silica dusts and their possible implication in various biological responses.

PubMed

Fubini, B; Bolis, V; Cavenago, A; Volante, M

1995-01-01

The effect of grinding, heating, and etching was investigated on polymorphs of silicon dioxide exhibiting different biological responses. Diatomaceous earths were converted into cristobalite at 1000 degrees C. Dusts obtained by grinding crystalline minerals exhibited different micromorphology and a propensity to originate surface radicals which decrease in the sequence cristobalite --> quartz --> coesite --> stishovite. The production of surface radicals was suppressed by grinding in the presence of water. Thermal treatments selectively quenched the radicals and decreased surface hydrophilicity. Quartz treated with aluminum lactate exhibited higher surface acidity when compared with pure quartz, with a reduction in fibrogenicity. Etching by hydrofluoric acid smoothed the particles with loss of specific surface. Adsorption of water on three cristobalite dusts of different origin (ground mineral, ex-diatomite, heated quartz) indicated a loss in heated quartz (1300 degrees C) that was relatable to the corresponding reduction in fibrogenicity.

Ureaplasma diversum Genome Provides New Insights about the Interaction of the Surface Molecules of This Bacterium with the Host

PubMed Central

Marques, Lucas M.; Rezende, Izadora S.; Barbosa, Maysa S.; Guimarães, Ana M. S.; Martins, Hellen B.; Campos, Guilherme B.; do Nascimento, Naíla C.; dos Santos, Andrea P.; Amorim, Aline T.; Santos, Verena M.; Farias, Sávio T.; Barrence, Fernanda Â. C.; de Souza, Lauro M.; Buzinhani, Melissa; Arana-Chavez, Victor E.; Zenteno, Maria E.; Amarante-Mendes, Gustavo P.; Messick, Joanne B.; Timenetsky, Jorge

2016-01-01

Whole genome sequencing and analyses of Ureaplasma diversum ATCC 49782 was undertaken as a step towards understanding U. diversum biology and pathogenicity. The complete genome showed 973,501 bp in a single circular chromosome, with 28.2% of G+C content. A total of 782 coding DNA sequences (CDSs), and 6 rRNA and 32 tRNA genes were predicted and annotated. The metabolic pathways are identical to other human ureaplasmas, including the production of ATP via hydrolysis of the urea. Genes related to pathogenicity, such as urease, phospholipase, hemolysin, and a Mycoplasma Ig binding protein (MIB)—Mycoplasma Ig protease (MIP) system were identified. More interestingly, a large number of genes (n = 40) encoding surface molecules were annotated in the genome (lipoproteins, multiple-banded antigen like protein, membrane nuclease lipoprotein and variable surface antigens lipoprotein). In addition, a gene encoding glycosyltransferase was also found. This enzyme has been associated with the production of capsule in mycoplasmas and ureaplasma. We then sought to detect the presence of a capsule in this organism. A polysaccharide capsule from 11 to 17 nm of U. diversum was observed trough electron microscopy and using specific dyes. This structure contained arabinose, xylose, mannose, galactose and glucose. In order to understand the inflammatory response against these surface molecules, we evaluated the response of murine macrophages J774 against viable and non-viable U. diversum. As with viable bacteria, non-viable bacteria were capable of promoting a significant inflammatory response by activation of Toll like receptor 2 (TLR2), indicating that surface molecules are important for the activation of inflammatory response. Furthermore, a cascade of genes related to the inflammasome pathway of macrophages was also up-regulated during infection with viable organisms when compared to non-infected cells. In conclusion, U. diversum has a typical ureaplasma genome and metabolism, and its surface molecules, including the identified capsular material, represent major components of the organism immunopathogenesis. PMID:27603136

Ureaplasma diversum Genome Provides New Insights about the Interaction of the Surface Molecules of This Bacterium with the Host.

PubMed

Marques, Lucas M; Rezende, Izadora S; Barbosa, Maysa S; Guimarães, Ana M S; Martins, Hellen B; Campos, Guilherme B; do Nascimento, Naíla C; Dos Santos, Andrea P; Amorim, Aline T; Santos, Verena M; Farias, Sávio T; Barrence, Fernanda  C; de Souza, Lauro M; Buzinhani, Melissa; Arana-Chavez, Victor E; Zenteno, Maria E; Amarante-Mendes, Gustavo P; Messick, Joanne B; Timenetsky, Jorge

2016-01-01

Whole genome sequencing and analyses of Ureaplasma diversum ATCC 49782 was undertaken as a step towards understanding U. diversum biology and pathogenicity. The complete genome showed 973,501 bp in a single circular chromosome, with 28.2% of G+C content. A total of 782 coding DNA sequences (CDSs), and 6 rRNA and 32 tRNA genes were predicted and annotated. The metabolic pathways are identical to other human ureaplasmas, including the production of ATP via hydrolysis of the urea. Genes related to pathogenicity, such as urease, phospholipase, hemolysin, and a Mycoplasma Ig binding protein (MIB)-Mycoplasma Ig protease (MIP) system were identified. More interestingly, a large number of genes (n = 40) encoding surface molecules were annotated in the genome (lipoproteins, multiple-banded antigen like protein, membrane nuclease lipoprotein and variable surface antigens lipoprotein). In addition, a gene encoding glycosyltransferase was also found. This enzyme has been associated with the production of capsule in mycoplasmas and ureaplasma. We then sought to detect the presence of a capsule in this organism. A polysaccharide capsule from 11 to 17 nm of U. diversum was observed trough electron microscopy and using specific dyes. This structure contained arabinose, xylose, mannose, galactose and glucose. In order to understand the inflammatory response against these surface molecules, we evaluated the response of murine macrophages J774 against viable and non-viable U. diversum. As with viable bacteria, non-viable bacteria were capable of promoting a significant inflammatory response by activation of Toll like receptor 2 (TLR2), indicating that surface molecules are important for the activation of inflammatory response. Furthermore, a cascade of genes related to the inflammasome pathway of macrophages was also up-regulated during infection with viable organisms when compared to non-infected cells. In conclusion, U. diversum has a typical ureaplasma genome and metabolism, and its surface molecules, including the identified capsular material, represent major components of the organism immunopathogenesis.

Cell Density Control of Staphylococcal Virulence Mediated by an Octapeptide Pheromone

NASA Astrophysics Data System (ADS)

Ji, Guangyong; Beavis, Ronald C.; Novick, Richard P.

1995-12-01

Some bacterial pathogens elaborate and secrete virulence factors in response to environmental signals, others in response to a specific host product, and still others in response to no discernible cue. In this study, we have demonstrated that the synthesis of Staphylococcus aureus virulence factors is controlled by a density-sensing system that utilizes an octapeptide produced by the organism itself. The octapeptide activates expression of the agr locus, a global regulator of the virulence response. This response involves the reciprocal regulation of genes encoding surface proteins and those encoding secreted virulence factors. As cells enter the postexponential phase, surface protein genes are repressed by agr and secretory protein genes are subsequently activated. The intracellular agr effector is a regulatory RNA, RNAIII, whose transcription is activated by an agr-encoded signal transduction system for which the octapeptide is the ligand.

Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611

PubMed Central

Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B.

2013-01-01

The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R 2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

The Rcs-Regulated Colanic Acid Capsule Maintains Membrane Potential in Salmonella enterica serovar Typhimurium

PubMed Central

Pando, Jasmine M.; Karlinsey, Joyce E.; Lara, Jimmie C.; Libby, Stephen J.

2017-01-01

ABSTRACT The Rcs phosphorelay and Psp (phage shock protein) systems are envelope stress responses that are highly conserved in gammaproteobacteria. The Rcs regulon was found to be strongly induced during metal deprivation of Salmonella enterica serovar Typhimurium lacking the Psp response. Nineteen genes activated by the RcsA-RcsB response regulator make up an operon responsible for the production of colanic acid capsular polysaccharide, which promotes biofilm development. Despite more than half a century of research, the physiological function of colanic acid has remained elusive. Here we show that Rcs-dependent colanic acid production maintains the transmembrane electrical potential and proton motive force in cooperation with the Psp response. Production of negatively charged exopolysaccharide covalently bound to the outer membrane may enhance the surface potential by increasing the local proton concentration. This provides a unifying mechanism to account for diverse Rcs/colanic acid-related phenotypes, including susceptibility to membrane-damaging agents and biofilm formation. PMID:28588134

Ecosystem responses to recent oceanographic variability in high-latitude Northern Hemisphere ecosystems

NASA Astrophysics Data System (ADS)

Mueter, Franz J.; Broms, Cecilie; Drinkwater, Kenneth F.; Friedland, Kevin D.; Hare, Jonathan A.; Hunt, George L., Jr.; Melle, Webjørn; Taylor, Maureen

2009-04-01

As part of the international MENU collaboration, we compared and contrasted ecosystem responses to climate-forced oceanographic variability across several high latitude regions of the North Pacific (Eastern Bering Sea (EBS) and Gulf of Alaska (GOA)) and North Atlantic Oceans (Gulf of Maine/Georges Bank (GOM/GB) and the Norwegian/Barents Seas (NOR/BAR)). Differences in the nitrate content of deep source waters and incoming solar radiation largely explain differences in average primary productivity among these ecosystems. We compared trends in productivity and abundance at various trophic levels and their relationships with sea-surface temperature. Annual net primary production generally increases with annual mean sea-surface temperature between systems and within the EBS, BAR, and GOM/GB. Zooplankton biomass appears to be controlled by both top-down (predation by fish) and bottom-up forcing (advection, SST) in the BAR and NOR regions. In contrast, zooplankton in the GOM/GB region showed no evidence of top-down forcing but appeared to control production of major fish populations through bottom-up processes that are independent of temperature variability. Recruitment of several fish stocks is significantly and positively correlated with temperature in the EBS and BAR, but cod and pollock recruitment in the EBS has been negatively correlated with temperature since the 1977 shift to generally warmer conditions. In each of the ecosystems, fish species showed a general poleward movement in response to warming. In addition, the distribution of groundfish in the EBS has shown a more complex, non-linear response to warming resulting from internal community dynamics. Responses to recent warming differ across systems and appear to be more direct and more pronounced in the higher latitude systems where food webs and trophic interactions are simpler and where both zooplankton and fish species are often limited by cold temperatures.

Creep and fatigue characteristics of Superpave mixtures.

DOT National Transportation Integrated Search

2005-01-01

Laboratory creep and fatigue testing was performed on five Superpave surface hot-mix asphalt mixtures placed at the Virginia Smart Road. Differences in creep and fatigue response attributable to production and compaction methods were investigated. In...

Surface functionalities of gold nanoparticles impact embryonic gene expression responses

PubMed Central

Truong, Lisa; Tilton, Susan C.; Zaikova, Tatiana; Richman, Erik; Waters, Katrina M.; Hutchison, James E.; Tanguay, Robert L.

2012-01-01

Incorporation of gold nanoparticles (AuNPs) into consumer products is increasing; however, there is a gap in available toxicological data to determine the safety of AuNPs. In this study, we utilised the embryonic zebrafish to investigate how surface functionalisation and charge influence molecular responses. Precisely engineered AuNPs with 1.5 nm cores were synthesised and functionalized with three ligands: 2-mercaptoethanesulfonic acid (MES), N,N,N-trimethylammoniumethanethiol (TMAT), or 2-(2-(2-mercaptoethoxy)ethoxy)ethanol. Developmental assessments revealed differential biological responses when embryos were exposed to the functionalised AuNPs at the same concentration. Using inductively coupled plasma–mass spectrometry, AuNP uptake was confirmed in exposed embryos. Following exposure to MES- and TMAT-AuNPs from 6 to 24 or 6 to 48 h post fertilisation, pathways involved in inflammation and immune response were perturbed. Additionally, transport mechanisms were misregulated after exposure to TMAT and MES-AuNPs, demonstrating that surface functionalisation influences many molecular pathways. PMID:22263968

[Optimization of one-step pelletization technology of Biqiu granules by Plackett-Burman design and Box-Behnken response surface methodology].

PubMed

Zhang, Yan-jun; Liu, Li-li; Hu, Jun-hua; Wu, Yun; Chao, En-xiang; Xiao, Wei

2015-11-01

First with the qualified rate of granules as the evaluation index, significant influencing factors were firstly screened by Plackett-Burman design. Then, with the qualified rate and moisture content as the evaluation indexes, significant factors that affect one-step pelletization technology were further optimized by Box-Behnken design; experimental data were imitated by multiple regression and second-order polynomial equation; and response surface method was used for predictive analysis of optimal technology. The best conditions were as follows: inlet air temperature of 85 degrees C, sample introduction speed of 33 r x min(-1), density of concrete 1. 10. One-step pelletization technology of Biqiu granules by Plackett-Burman design and Box-Behnken response surface methodology was stable and feasible with good predictability, which provided reliable basis for the industrialized production of Biqiu granules.

Comparison of Resource Requirements for a Wind Tunnel Test Designed with Conventional vs. Modern Design of Experiments Methods

NASA Technical Reports Server (NTRS)

DeLoach, Richard; Micol, John R.

2011-01-01

The factors that determine data volume requirements in a typical wind tunnel test are identified. It is suggested that productivity in wind tunnel testing can be enhanced by managing the inference error risk associated with evaluating residuals in a response surface modeling experiment. The relationship between minimum data volume requirements and the factors upon which they depend is described and certain simplifications to this relationship are realized when specific model adequacy criteria are adopted. The question of response model residual evaluation is treated and certain practical aspects of response surface modeling are considered, including inference subspace truncation. A wind tunnel test plan developed by using the Modern Design of Experiments illustrates the advantages of an early estimate of data volume requirements. Comparisons are made with a representative One Factor At a Time (OFAT) wind tunnel test matrix developed to evaluate a surface to air missile.

[Optimization of prokaryotic expression conditions of Leptospira interrogans trigeminy genus-specific protein antigen based on surface response analysis].

PubMed

Wang, Jiang; Luo, Dongjiao; Sun, Aihua; Yan, Jie

2008-07-01

Lipoproteins LipL32 and LipL21 and transmembrane protein OMPL1 have been confirmed as the superficial genus-specific antigens of Leptospira interrogans, which can be used as antigens for developing a universal genetic engineering vaccine. In order to obtain high expression of an artificial fusion gene lipL32/1-lipL21-ompL1/2, we optimized prokaryotic expression conditions. We used surface response analysis based on the central composite design to optimize culture conditions of a new antigen protein by recombinant Escherichia coli DE3.The culture conditions included initial pH, induction start time, post-induction time, Isopropyl beta-D-thiogalactopyranoside (IPTG) concentration, and temperature. The maximal production of antigen protein was 37.78 mg/l. The optimal culture conditions for high recombinant fusion protein was determined: initial pH 7.9, induction start time 2.5 h, a post-induction time of 5.38 h, 0.20 mM IPTG, and a post-induction temperature of 31 degrees C. Surface response analysis based on CCD increased the target production. This statistical method reduced the number of experiments required for optimization and enabled rapid identification and integration of the key culture condition parameters for optimizing recombinant protein expression.

Effects of the culture media optimization on pectinase production by Enterobacter sp. PSTB-1.

PubMed

Reddy, M Purna Chandra; Saritha, K V

2016-12-01

In the present study, media composition for high production of pectinase by Enterobacter sp. PSTB-1 in submerged fermentation was optimized using response surface methodology (RSM). Mango fruit processing industrial waste (MIW) was used as substrate (carbon source) as it contains high amount of pectin. Enterobacter sp. PSTB-1 used in present study has given pectin clear zone (PCZ) of 34 mm is higher than other isolates. The experimental results made by statistical design for high pectinase production revealed that the suitable media components: NaNO 3 2.0 g/l, KCl 0.50 g/l, KH 2 PO 4 1.0 g/l, MgSO 4 ·7H 2 O 0.50 g/l, Yeast extract 1.0 g/l, mango industrial waste powder 5.0 g/l. The actual pectinase activity was 75.23 % correlated with the predicted pectinase activity where the model (CCD) was significant. Response surface modelling applied effectively to optimize the production of pectinase in submerged fermentation to make the process low cost-effective by using powdered mango industrial waste as substrate.

Optimization of critical medium components using response surface methodology for phenazine-1-carboxylic acid production by Pseudomonas sp. M-18Q.

PubMed

Yuan, Li-Li; Li, Ya-Qian; Wang, Yi; Zhang, Xue-Hong; Xu, Yu-Quan

2008-03-01

The optimal flask-shaking batch fermentation medium for phenazine-1-carboxylic acid (PCA) production by Pseudomonas sp. M-18Q, a qscR chromosomal inactivated mutant of the strain M18 was studied using statistical experimental design and analysis. The Plackett-Burman design (PBD) was used to evaluate the effects of eight medium components on the production of PCA, which showed that glucose and soytone were the most significant ingredients (P<0.05). The steepest ascent experiment was adopted to determine the optimal region of the medium composition. The optimum composition of the fermentation medium for maximum PCA yield, as determined on the basis of a five-level two-factor central composite design (CCD), was obtained by response surface methodology (RSM). The high correlation between the predicted and observed values indicated the validity of the model. A maximum PCA yield of 1240 mg/l was obtained at 17.81 g/l glucose and 11.47 g/l soytone, and the production was increased by 65.3% compared with that using the original medium, which was at 750 mg/l.

Modeling and optimization of phospholipase A₁-catalyzed hydrolysis of phosphatidylcholine using response surface methodology for lysophosphatidylcholine production.

PubMed

Lim, Chang Wan; Kim, Byung Hee; Kim, In-Hwan; Lee, Moon-Won

2015-01-01

Modeling the phospholipase A1 (PLA1 )-catalyzed partial hydrolysis of soy phosphatidylcholine (PC) in hexane for the production of lysophosphatidylcholine (LPC) and optimizing the reaction conditions using response surface methodology were described. The reaction was performed with 4 g of PC in a stirred batch reactor using a commercial PLA1 (Lecitase Ultra) as the biocatalyst. The effects of temperature, reaction time, water content, and enzyme loading on LPC and glycerylphosphorylcholine (GPC) content in the reaction products were elucidated using the models established. Optimal reaction conditions for maximizing the LPC content while suppressing acyl migration, which causes GPC formation, were as follows: temperature, 60°C; reaction time, 3 h; water content, 10% of PC; and enzyme loading, 1% of PC. When the reaction was conducted with 40 g of PC under these conditions, the reaction products contained 83.7 mol % LPC and were free of GPC. LPC had a higher total unsaturated fatty acid content than original PC had and was mainly composed of linoleic acid (78.0 mol % of the total fatty acids). © 2014 American Institute of Chemical Engineers.

Nutrient Optimization Using Response Surface Methodology for Simultaneous Biomass and Bioactive Compound Production by Lion's Mane Medicinal Mushroom, Hericium erinaceus (Agaricomycetes).

PubMed

Ofosu, Fred K; Yu, Xiaobin; Wang, Qiang; Li, Hanguang

2016-01-01

Due to the unpleasant side effects of long-term use of commercially available drugs, the discovery and development of natural therapeutic agents to prevent life-debilitating diseases is urgently needed. In the present study, the optimization of medium composition for maximum mycelial biomass and bioactive compounds production by Hericium erinaceus was studied using response surface methodology based on a central composite design. Under the optimal conditions and at a pH of 5.41 ± 0.28, the maximum mycelial biomass and exopolysaccharide production reached 25.0 ± 1.38 g/L and 1.73 ± 0.06 g/L, respectively, compared with 22.65 ± 0.10 g/L and 1.56 ± 0.23 g/L in the basal medium, after 7 days of cultivation. Furthermore, we report for the first time the production of adenosine, both intra- and extracellularly in submerged cultures of H. erinaceus. Although most of the adenosine detected existed in the culture medium, the highest intracellular and extracellular adenosine concentrations of 150.84 ± 1.87 mg/L and 142.48 ± 3.78 mg/L were achieved after 7 and 6 days of cultivation, respectively.

Reducing Surface Clutter in Cloud Profiling Radar Data

NASA Technical Reports Server (NTRS)

Tanelli, Simone; Pak, Kyung; Durden, Stephen; Im, Eastwood

2008-01-01

An algorithm has been devised to reduce ground clutter in the data products of the CloudSat Cloud Profiling Radar (CPR), which is a nadir-looking radar instrument, in orbit around the Earth, that measures power backscattered by clouds as a function of distance from the instrument. Ground clutter contaminates the CPR data in the lowest 1 km of the atmospheric profile, heretofore making it impossible to use CPR data to satisfy the scientific interest in studying clouds and light rainfall at low altitude. The algorithm is based partly on the fact that the CloudSat orbit is such that the geodetic altitude of the CPR varies continuously over a range of approximately 25 km. As the geodetic altitude changes, the radar timing parameters are changed at intervals defined by flight software in order to keep the troposphere inside a data-collection time window. However, within each interval, the surface of the Earth continuously "scans through" (that is, it moves across) a few range bins of the data time window. For each radar profile, only few samples [one for every range-bin increment ((Delta)r = 240 m)] of the surface-clutter signature are available around the range bin in which the peak of surface return is observed, but samples in consecutive radar profiles are offset slightly (by amounts much less than (Delta)r) with respect to each other according to the relative change in geodetic altitude. As a consequence, in a case in which the surface area under examination is homogenous (e.g., an ocean surface), a sequence of consecutive radar profiles of the surface in that area contains samples of the surface response with range resolution (Delta)p much finer than the range-bin increment ((Delta)p << r). Once the high-resolution surface response has thus become available, the profile of surface clutter can be accurately estimated by use of a conventional maximum-correlation scheme: A translated and scaled version of the high-resolution surface response is fitted to the observed low-resolution profile. The translation and scaling factors that optimize the fit in a maximum-correlation sense represent (1) the true position of the surface relative to the sampled surface peak and (2) the magnitude of the surface backscatter. The performance of this algorithm has been tested on CloudSat data acquired over an ocean surface. A preliminary analysis of the test data showed a surface-clutter-rejection ratio over flat surfaces of >10 dB and a reduction of the contaminated altitude over ocean from about 1 km to about 0.5 km (over the ocean). The algorithm has been embedded in CloudSat L1B processing as of Release 04 (July 2007), and the estimated flat surface clutter is removed in L2B-GEOPROF product from the observed profile of reflectivity (see CloudSat product documentation for details and performance at http://www.cloudsat.cira.colostate.edu/ dataSpecs.php?prodid=1).

Optimization and modeling of laccase production by Trametes versicolor in a bioreactor using statistical experimental design.

PubMed

Tavares, A P M; Coelho, M A Z; Agapito, M S M; Coutinho, J A P; Xavier, A M R B

2006-09-01

Experimental design and response surface methodologies were applied to optimize laccase production by Trametes versicolor in a bioreactor. The effects of three factors, initial glucose concentration (0 and 9 g/L), agitation (100 and 180 rpm), and pH (3.0 and 5.0), were evaluated to identify the significant effects and its interactions in the laccase production. The pH of the medium was found to be the most important factor, followed by initial glucose concentration and the interaction of both factors. Agitation did not seem to play an important role in laccase production, nor did the interaction agitation x medium pH and agitation x initial glucose concentration. Response surface analysis showed that an initial glucose concentration of 11 g/L and pH controlled at 5.2 were the optimal conditions for laccase production by T. versicolor. Under these conditions, the predicted value for laccase activity was >10,000 U/L, which is in good agreement with the laccase activity obtained experimentally (11,403 U/L). In addition, a mathematical model for the bioprocess was developed. It is shown that it provides a good description of the experimental profile observed, and that it is capable of predicting biomass growth based on secondary process variables.

Design and optimization of hydrogen production from hydrothermally pretreated sugarcane bagasse using response surface methodology.

PubMed

Soares, Lais Américo; Braga, Juliana Kawanishi; Motteran, Fabrício; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

2017-07-01

Hydrogen production from hydrothermally pretreated (200 °C for 10 min at 16 bar) sugarcane bagasse was analyzed using response surface methodology. The yeast extract concentration and the temperature had a significant influence for hydrogen production (p-value 0.027 and 0.009, respectively). Maximum hydrogen production (17.7 mmol/L) was observed with 3 g/L yeast extract at 60 °C (C10). In this conditions were produced acetic acid (50.44 mg/L), butyric acid (209.71 mg/L), ethanol (38.4 mg/L), and methane (6.27 mmol/L). Lower hydrogen productions (3.5 mmol/L and 3.9 mmol/L) were observed under the conditions C7 (2 g/L of yeast extract, 35.8 °C) and C9 (1 g/L of yeast extract, 40 °C), respectively. The low yeast extract concentration and low temperature caused a negative effect on the hydrogen production. By means of denaturing gradient gel electrophoresis 20% of similarity was observed between the archaeal population of mesophilic (35 and 40 °C) and thermophilic (50, 60 and 64 °C) reactors. Likewise, similarity of 22% was noted between the bacterial population for the reactors with the lowest hydrogen production (3.5 mmol/L), at 35.8 °C and with the highest hydrogen production (17.7 mmol/L) at 60 °C demonstrating that microbial population modification was a function of incubation temperature variation.

Observational insights into chlorophyll distributions of subtropical South Indian Ocean eddies

NASA Astrophysics Data System (ADS)

Dufois, François; Hardman-Mountford, Nick J.; Fernandes, Michelle; Wojtasiewicz, Bozena; Shenoy, Damodar; Slawinski, Dirk; Gauns, Mangesh; Greenwood, Jim; Toresen, Reidar

2017-04-01

The South Indian Ocean subtropical gyre has been described as a unique environment where anticyclonic ocean eddies highlight enhanced surface chlorophyll in winter. The processes responsible for this chlorophyll increase in anticyclones have remained elusive, primarily because previous studies investigating this unusual behavior were mostly based on satellite data, which only views the ocean surface. Here we present in situ data from an oceanographic voyage focusing on the mesoscale variability of biogeochemical variables across the subtropical gyre. During this voyage an autonomous biogeochemical profiling float transected an anticyclonic eddy, recording its physical and biological state over a period of 6 weeks. We show that several processes might be responsible for the eddy/chlorophyll relationship, including horizontal advection of productive waters and deeper convective mixing in anticyclonic eddies. While a deep chlorophyll maximum is present in the subtropical Indian Ocean outside anticyclonic eddies, mixing reaches deeper in anticyclonic eddy cores, resulting in increased surface chlorophyll due to the stirring of the deep chlorophyll maximum and possibly resulting in new production from nitrate injection below the deep chlorophyll maximum.

Microbially induced separation of quartz from hematite using sulfate reducing bacteria.

PubMed

Prakasan, M R Sabari; Natarajan, K A

2010-07-01

Cells and metabolic products of Desulfovibrio desulfuricans were successfully used to separate quartz from hematite through environmentally benign microbially induced flotation. Bacterial metabolic products such as extracellular proteins and polysaccharides were isolated from both unadapted and mineral-adapted bacterial metabolite and their basic characteristics were studied in order to get insight into the changes brought about on bioreagents during adaptation. Interaction between bacterial cells and metabolites with minerals like hematite and quartz brought about significant surface-chemical changes on both the minerals. Quartz was rendered more hydrophobic, while hematite became more hydrophilic after biotreatment. The predominance of bacterial polysaccharides on interacted hematite and of proteins on quartz was responsible for the above surface-chemical changes, as attested through adsorption studies. Surface-chemical changes were also observed on bacterial cells after adaptation to the above minerals. Selective separation of quartz from hematite was achieved through interaction with quartz-adapted bacterial cells and metabolite. Mineral-specific proteins secreted by quartz-adapted cells were responsible for conferment of hydrophobicity on quartz resulting in enhanced separation from hematite through flotation. 2010 Elsevier B.V. All rights reserved.

Comments on Interior’s Surface Mining Regulations.

DTIC Science & Technology

1981-08-05

regulations and responses to pro- posed regulati n, (2) identified studies on cost/benefit analy- sis of environme ital regulations and selected ...agricultural production at the national level, in some rural counties essentially the entire area is underlain with strippable coal. obviously, surface mining...1980).) Illinois, which has the most strippable coal reserves underlying prime farmland, has two heavily worked coal seams which are continuous. One

Optimisation of warpage on thin shell plastic part using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

NASA Astrophysics Data System (ADS)

Asyirah, B. N.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

2017-09-01

In manufacturing a variety of parts, plastic injection moulding is widely use. The injection moulding process parameters have played important role that affects the product's quality and productivity. There are many approaches in minimising the warpage ans shrinkage such as artificial neural network, genetic algorithm, glowworm swarm optimisation and hybrid approaches are addressed. In this paper, a systematic methodology for determining a warpage and shrinkage in injection moulding process especially in thin shell plastic parts are presented. To identify the effects of the machining parameters on the warpage and shrinkage value, response surface methodology is applied. In thos study, a part of electronic night lamp are chosen as the model. Firstly, experimental design were used to determine the injection parameters on warpage for different thickness value. The software used to analyse the warpage is Autodesk Moldflow Insight (AMI) 2012.

Optimisation of the enzyme-based determination of hydrogen peroxide using the quartz crystal microbalance.

PubMed

Martin, S P; Lynch, J M; Reddy, S M

2002-09-01

The benzidines, 3,3'-diaminobenzidine (DAB), 3,3'-dimethoxybenzidine (DMOB) and 3,3',5,5'-tetramethylbenzidine (TMB) were enzymatically oxidised to detect hydrogen peroxide, using the quartz crystal. The oxidised product mainly remains in suspension, resulting in a limited quartz sensor signal. We have used two non-ionic surfactants, Tween 80 and Triton X-100 to interact with the oxidised amphiphilic products to increase their solubility and surface activity, and their ability to adsorb to the crystal surface. Tween 80 exhibits optimised response effects for DAB, DMOB and TMB at 0.012, 0.005, and 0.002% (v/v), respectively, whereas Triton X-100 is optimum at 0.1, 0.2, and 0.006% (v/v), respectively. As a result, we have improved the quartz crystal sensor sensitivity to peroxide. The use of Triton X-100 gave an improved response time.

Cell surface retention sequence binding protein-1 interacts with the v-sis gene product and platelet-derived growth factor beta-type receptor in simian sarcoma virus-transformed cells.

PubMed

Boensch, C; Huang, S S; Connolly, D T; Huang, J S

1999-04-09

The cell surface retention sequence (CRS) binding protein-1 (CRSBP-1) is a newly identified membrane glycoprotein which is hypothesized to be responsible for cell surface retention of the oncogene v-sis and c-sis gene products and other secretory proteins containing CRSs. In simian sarcoma virus-transformed NIH 3T3 cells (SSV-NIH 3T3 cells), a fraction of CRSBP-1 was demonstrated at the cell surface and underwent internalization/recycling as revealed by cell surface 125I labeling and its resistance/sensitivity to trypsin digestion. However, the majority of CRSBP-1 was localized in intracellular compartments as evidenced by the resistance of most of the 35S-metabolically labeled CRSBP-1 to trypsin digestion, and by indirect immunofluorescent staining. CRSBP-1 appeared to form complexes with proteolytically processed forms (generated at and/or after the trans-Golgi network) of the v-sis gene product and with a approximately 140-kDa proteolytically cleaved form of the platelet-derived growth factor (PDGF) beta-type receptor, as demonstrated by metabolic labeling and co-immunoprecipitation. CRSBP-1, like the v-sis gene product and PDGF beta-type receptor, underwent rapid turnover which was blocked in the presence of 100 microM suramin. In normal and other transformed NIH 3T3 cells, CRSBP-1 was relatively stable and did not undergo rapid turnover and internalization/recycling at the cell surface. These results suggest that in SSV-NIH 3T3 cells, CRSBP-1 interacts with and forms ternary and binary complexes with the newly synthesized v-sis gene product and PDGF beta-type receptor at the trans-Golgi network and that the stable binary (CRSBP-1.v-sis gene product) complex is transported to the cell surface where it presents the v-sis gene product to unoccupied PDGF beta-type receptors during internalization/recycling.

Optimization of fermentation conditions for 1,3-propanediol production by marine Klebsiella pneumonia HSL4 using response surface methodology

NASA Astrophysics Data System (ADS)

Li, Lili; Zhou, Sheng; Ji, Huasong; Gao, Ren; Qin, Qiwei

2014-09-01

The industrially important organic compound 1,3-propanediol (1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K2 HPO4, 7.6 g/L (NH4)2 SO4, 3.0 g/L KH2 PO4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.

Optimization of erythritol and glycerol accumulation in conidia of Beauveria bassiana by solid-state fermentation, using response surface methodology.

PubMed

Tarocco, Federico; Lecuona, Roberto E; Couto, Alicia S; Arcas, Jorge A

2005-09-01

Entomopathogenic fungi are widely produced for use as mycoinsecticides. Therefore, improvement of the shelf life of fungal propagules under good and adverse conditions should be a pre-requisite of their production. In order to improve conidial physiology as well as mycoinsecticide efficiency, culture conditions may be varied. The Doehlert design was used to generate response surfaces with an estimation of the parameters of the quadratic model allowing the study of three different factors at a different number of levels. This experimental design was applied to optimize water activity (aw), pH, and fermentation time for Beauveria bassiana conidial production and accumulation of polyols in solid-state fermentation. Thus, it was possible to identify the region in the experimental range in which the optimum values of these parameters were simultaneously achieved. Maximal conidia production was achieved at pH 5-6 and aw=0.999. Under these conditions, polyol accumulation was 3 mg erythritol/g conidia and 29.6 mg glycerol/g conidia. However, maximal polyol accumulation was achieved at pH 4.5 and aw 0.950; erythritol production increased 33-fold and glycerol production 4.5-fold. Under these conditions conidia production was 1,000 times lower. The possibilities of increasing the quality of the biocontrol agent without neglecting yield are discussed.

Biological pretreatment of rice straw with Streptomyces griseorubens JSD-1 and its optimized production of cellulase and xylanase for improved enzymatic saccharification efficiency.

PubMed

Zhang, Dan; Luo, Yanqing; Chu, Shaohua; Zhi, Yuee; Wang, Bin; Zhou, Pei

2016-08-17

Biological pretreatment of rice straw and production of reducing sugars by hydrolysis of bio-pretreated material with Streptomyces griseorubens JSD-1 was investigated. After 10 days of incubation, various chemical compositions of inoculated rice straw were degraded and used for further enzymatic hydrolysis studies. The production of cellulolytic enzyme by S. griseorubens JSD-1 favored the conversion of cellulose to reducing sugars. The culture medium for cellulolytic enzyme production by using agro-industrial wastes was optimized through response surface methodology. According to the response surface analysis, the concentrations of 11.13, 20.34, 4.61, and 2.85 g L(-1) for rice straw, wheat bran, peptone, and CaCO3, respectively, were found to be optimum for cellulase and xylanase production. Then the hydrolyzed spent Streptomyces cells were used as a nitrogen source and the maximum filter paper cellulase, carboxymethylcellulase, and xylanase activities of 25.79, 78.91, and 269.53 U mL(-1) were achieved. The crude cellulase produced by S. griseorubens JSD-1 was subsequently used for the hydrolysis of bio-pretreated rice straw, and the optimum saccharification efficiency of 88.13% was obtained, indicating that the crude enzyme might be used instead of commercial cellulase during a saccharification process. These results give a basis for further study of bioethanol production from agricultural cellulosic waste.

Optimization of polyhydroxybutyrate production utilizing waste water as nutrient source by Botryococcus braunii Kütz using response surface methodology.

PubMed

Kavitha, Ganapathy; Kurinjimalar, Chidambaram; Sivakumar, Krishnan; Kaarthik, Muthukumar; Aravind, Rajamani; Palani, Perumal; Rengasamy, Ramasamy

2016-12-01

Investigations have been made to optimize various factors including pH, temperature, and substrate for enhanced polyhydroxybutyrate (PHB) production in Botryococcus braunii which serves as a pioneer for production of bioplastic (PHB). Polyhydroxybutyrate is a natural, decomposable polymers accumulated by the microorganism under different nutritional condition. Strain selection was done by staining method using Sudan black and Nile red dye. Using response surface methodology (RSM), three level- three variables Box Behnken design (BBD), the best potential combination of pH (4-11), temperature (30-50°C) and sewage waste water as substrate fed at different concentrations at 20%-100% for maximum PHB production was investigated. Maximum yield (247±0.42mg/L) of PHB dry weight was achieved from the 60% concentration of sewage waste water as a growth medium at pH 7.5 at 40°C. It was well in close agreement with the value predicted by RSM model yield (246± 0.32mg/L). Thus the study shows the production of PHB by B. braunii along with the basic characterization of PHB by using FTIR and TEM analysis. These preliminary studies indicated that PHB can also be produced by B. braunii utilizing waste water. There is no report on the optimization of PHB production in this microalgae have been documented. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of a coupled ecosystem-chemical equilibrium model, DayCent-Chem, to stream and soil chemistry in a Rocky Mountain watershed

USGS Publications Warehouse

Hartman, M.D.; Baron, Jill S.; Ojima, D.S.

2007-01-01

Atmospheric deposition of sulfur and nitrogen species have the potential to acidify terrestrial and aquatic ecosystems, but nitrate and ammonium are also critical nutrients for plant and microbial productivity. Both the ecological response and the hydrochemical response to atmospheric deposition are of interest to regulatory and land management agencies. We developed a non-spatial biogeochemical model to simulate soil and surface water chemistry by linking the daily version of the CENTURY ecosystem model (DayCent) with a low temperature aqueous geochemical model, PHREEQC. The coupled model, DayCent-Chem, simulates the daily dynamics of plant production, soil organic matter, cation exchange, mineral weathering, elution, stream discharge, and solute concentrations in soil water and stream flow. By aerially weighting the contributions of separate bedrock/talus and tundra simulations, the model was able to replicate the measured seasonal and annual stream chemistry for most solutes for Andrews Creek in Loch Vale watershed, Rocky Mountain National Park. Simulated soil chemistry, net primary production, live biomass, and soil organic matter for forest and tundra matched well with measurements. This model is appropriate for accurately describing ecosystem and surface water chemical response to atmospheric deposition and climate change. ?? 2006 Elsevier B.V. All rights reserved.

Evaluation and optimization of ethanol production from carob pod extract by Zymomonas mobilis using response surface methodology.

PubMed

Vaheed, Hossein; Shojaosadati, Seyed Abbas; Galip, Hasan

2011-01-01

In this research, ethanol production from carob pod extract (extract) using Zymomonas mobilis with medium optimized by Plackett-Burman (P-B) and response surface methodologies (RSM) was studied. Z. mobilis was recognized as useful for ethanol production from carob pod extract. The effects of initial concentrations of sugar, peptone, and yeast extract as well as agitation rate (rpm), pH, and culture time in nonhydrolyzed carob pod extract were investigated. Significantly affecting variables (P = 0.05) in the model obtained from RSM studies were: weights of bacterial inoculum, initial sugar, peptone, and yeast extract. Acid hydrolysis was useful to complete conversion of sugars to glucose and fructose. Nonhydrolyzed extract showed higher ethanol yield and residual sugar compared with hydrolyzed extract. Ethanol produced (g g(-1) initial sugar, as the response) was not significantly different (P = 0.05) when Z. mobilis performance was compared in hydrolyzed and nonhydrolyzed extract. The maximum ethanol of 0.34 ± 0.02 g g(-1) initial sugar was obtained at 30°C, initial pH 5.2, and 80 rpm, using concentrations (g per 50 mL culture media) of: inoculum bacterial dry weight, 0.017; initial sugar, 5.78; peptone, 0.43; yeast extract, 0.43; and culture time of 36 h.

CO2 controlled flocculation of microalgae using pH responsive cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Eyley, Samuel; Vandamme, Dries; Lama, Sanjaya; van den Mooter, Guy; Muylaert, Koenraad; Thielemans, Wim

2015-08-01

Cellulose nanocrystals were grafted with imidazole functionalities up to DS 0.06 using a one-pot functionalization strategy. The resulting nanocrystals were shown to have a pH responsive surface charge which was found to be positive below pH 6 and negative above pH 7. These imidazolyl cellulose nanocrystals were tested for flocculation of Chlorella vulgaris using CO2 to induce flocculation. Up to 90% flocculation efficiency was achieved with 200 mg L-1 dose. Furthermore, the modified cellulose nanocrystals showed good compatibility with the microalgae during cultivation, giving potential for the production of reversible flocculation systems.Cellulose nanocrystals were grafted with imidazole functionalities up to DS 0.06 using a one-pot functionalization strategy. The resulting nanocrystals were shown to have a pH responsive surface charge which was found to be positive below pH 6 and negative above pH 7. These imidazolyl cellulose nanocrystals were tested for flocculation of Chlorella vulgaris using CO2 to induce flocculation. Up to 90% flocculation efficiency was achieved with 200 mg L-1 dose. Furthermore, the modified cellulose nanocrystals showed good compatibility with the microalgae during cultivation, giving potential for the production of reversible flocculation systems. Electronic supplementary information (ESI) available: Spectra for all products. See DOI: 10.1039/C5NR03853G

Investigation of the Process Conditions for Hydrogen Production by Steam Reforming of Glycerol over Ni/Al₂O₃ Catalyst Using Response Surface Methodology (RSM).

PubMed

Ebshish, Ali; Yaakob, Zahira; Taufiq-Yap, Yun Hin; Bshish, Ahmed

2014-03-19

In this work; a response surface methodology (RSM) was implemented to investigate the process variables in a hydrogen production system. The effects of five independent variables; namely the temperature (X₁); the flow rate (X₂); the catalyst weight (X₃); the catalyst loading (X₄) and the glycerol-water molar ratio (X₅) on the H₂ yield (Y₁) and the conversion of glycerol to gaseous products (Y₂) were explored. Using multiple regression analysis; the experimental results of the H₂ yield and the glycerol conversion to gases were fit to quadratic polynomial models. The proposed mathematical models have correlated the dependent factors well within the limits that were being examined. The best values of the process variables were a temperature of approximately 600 °C; a feed flow rate of 0.05 mL/min; a catalyst weight of 0.2 g; a catalyst loading of 20% and a glycerol-water molar ratio of approximately 12; where the H₂ yield was predicted to be 57.6% and the conversion of glycerol was predicted to be 75%. To validate the proposed models; statistical analysis using a two-sample t -test was performed; and the results showed that the models could predict the responses satisfactorily within the limits of the variables that were studied.

Electron Microscopic Analysis of Surface Inorganic Substances on Oral and Combustible Tobacco Products

PubMed Central

Halstead, Mary M.; Watson, Clifford H.; Pappas, R. Steven

2015-01-01

Though quantitative trace toxic metals analyses have been performed on tobacco products, little has been published on inorganic particulate constituents on and inside the products. We analyzed these constituents using scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDS). The nature of SEM-EDS instrumentation makes it an ideal choice for inorganic particulate analyses and yields relevant information to potential exposures during consumption of oral tobacco products, and possibly as a consequence of smoking. Aluminum silicates, silica, and calcium compounds were common inorganic particulate constituents of tobacco products. Aluminum silicates and silica from soil were found on external leaf surfaces. Phytolithic silica, found in the lumen of the plant leaf, is of biogenic origin. Calcium oxalate was also apparently of biogenic origin. Small mineral deposits on tobacco could have health implications. Minerals found on the surfaces of smokeless tobacco products could possibly abrade the oral mucosa and contribute to the oral inflammatory responses observed with smokeless tobacco product use. If micron and sub-micron size calcium particles on cigarette filler were transported in mainstream smoke, they could potentially induce a pulmonary irritant inflammation when inhaled. The transport of aluminum silicate and silica in smoke could potentially also contribute to chronic inflammatory disease. PMID:26286581

Role of Exposed Surfaces on Zinc Oxide Nanostructures in the Catalytic Ethanol Transformation.

PubMed

Morales, María V; Asedegbega-Nieto, Esther; Iglesias-Juez, Ana; Rodríguez-Ramos, Inmaculada; Guerrero-Ruiz, Antonio

2015-07-08

For a series of nanometric ZnO materials, the relationship between their morphological and surface functionalities and their catalytic properties in the selective decomposition of ethanol to yield acetaldehyde was explored. Six ZnO solids were prepared by a microemulsion-precipitation method and the thermal decomposition of different precursors and compared with a commercial sample. All these materials were characterized intensively by XRD and SEM to obtain their morphological specificities. Additionally, surface area determinations and IR spectroscopy were used to detect differences in the surface properties. The density of acid surface sites was determined quantitatively using an isopropanol dehydration test. Based on these characterization studies and on the results of the catalytic tests, it has been established that ZnO basal surfaces seem to be responsible for the production of ethylene as a minor product as well as for secondary reactions that yield acetyl acetate. Furthermore, one specific type of exposed hydroxyl groups appears to govern the surface catalytic properties. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced α-amylase production by a marine protist, Ulkenia sp. using response surface methodology and genetic algorithm.

PubMed

Shirodkar, Priyanka V; Muraleedharan, Usha Devi

2017-11-26

Amylases are a group of enzymes with a wide variety of industrial applications. Enhancement of α-amylase production from the marine protists, thraustochytrids has been attempted for the first time by applying statistical-based experimental designs using response surface methodology (RSM) and genetic algorithm (GA) for optimization of the most influencing process variables. A full factorial central composite experimental design was used to study the cumulative interactive effect of nutritional components viz., glucose, corn starch, and yeast extract. RSM was performed on two objectives, that is, growth of Ulkenia sp. AH-2 (ATCC® PRA-296) and α-amylase activity. When GA was conducted for maximization of the enzyme activity, the optimal α-amylase activity was found to be 71.20 U/mL which was close to that obtained by RSM (71.93 U/mL), both of which were in agreement with the predicted value of 72.37 U/mL. Optimal growth at the optimized process variables was found to be 1.89A 660nm . The optimized medium increased α-amylase production by 1.2-fold.

Optimization of methane production in anaerobic co-digestion of poultry litter and wheat straw at different percentages of total solid and volatile solid using a developed response surface model.

PubMed

Shen, Jiacheng; Zhu, Jun

2016-01-01

Poultry litter (PL) can be good feedstock for biogas production using anaerobic digestion. In this study, methane production from batch co-digestion of PL and wheat straw (WS) was investigated for two factors, i.e., total solid (2%, 5%, and 10%) and volatile solid (0, 25, and 50% of WS), constituting a 3 × 3 experimental design. The results showed that the maximum specific methane volume [197 mL (g VS)(‑1)] was achieved at 50% VS from WS at 5% TS level. It was estimated that the inhibitory threshold of free ammonia was about 289 mg L(--1), beyond which reduction of methanogenic activity by at least 54% was observed. The specific methane volume and COD removal can be expressed using two response surface models (R(2) = 0.9570 and 0.9704, respectively). Analysis of variance of the experimental results indicated that the C/N ratio was the most significant factor influencing the specific methane volume and COD removal in the co-digestion of these two materials.

Optimization of physical conditions for the production of thermostable T1 lipase in Pichia guilliermondii strain SO using response surface methodology.

PubMed

Abu, Mary Ladidi; Nooh, Hisham Mohd; Oslan, Siti Nurbaya; Salleh, Abu Bakar

2017-11-10

Pichia guilliermondii was found capable of expressing the recombinant thermostable lipase without methanol under the control of methanol dependent alcohol oxidase 1 promoter (AOXp 1). In this study, statistical approaches were employed for the screening and optimisation of physical conditions for T1 lipase production in P. guilliermondii. The screening of six physical conditions by Plackett-Burman Design has identified pH, inoculum size and incubation time as exerting significant effects on lipase production. These three conditions were further optimised using, Box-Behnken Design of Response Surface Methodology, which predicted an optimum medium comprising pH 6, 24 h incubation time and 2% inoculum size. T1 lipase activity of 2.0 U/mL was produced with a biomass of OD 600 23.0. The process of using RSM for optimisation yielded a 3-fold increase of T1 lipase over medium before optimisation. Therefore, this result has proven that T1 lipase can be produced at a higher yield in P. guilliermondii.

Optimization of furfural and 5-hydroxymethylfurfural production from wheat straw by a microwave-assisted process.

PubMed

Yemiş, Oktay; Mazza, Giuseppe

2012-04-01

Optimization of acid-catalyzed conversion conditions of wheat straw into furfural, 5-hydroxymethylfurfural (HMF), glucose, and xylose was studied by response surface methodology (RSM). A central composite design (CCD) was used to determine the effects of independent variables, including reaction temperature (140-200 °C), residence time (1-41 min), pH (0.1-2.1), and liquid:solid ratio (15-195 mL/g) on furan and sugar production. The surface response analysis revealed that temperature, time and pH had a strong influence on the furfural, HMF, xylose and glucose yield, whereas liquid to solid ratio was found not to be significant. The initial pH of solution was the most important variable in acid-catalyzed conversion of wheat straw to furans. The maximum predicted furfural, HMF, xylose and glucose yields were 66%, 3.4%, 100%, and 65%, respectively. This study demonstrated that the microwave-assisted process was a very effective method for the xylose production from wheat straw by diluted acid catalysis. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Optimization of Lactide synthesis from Lactic Acid in biorefinery of palm oil waste using Response Surface Methodology

NASA Astrophysics Data System (ADS)

Gozan, M.; Kamilah, F.; Whulanza, Y.; Rahmayetty

2018-03-01

Ring open polymerization is one of the production polylactic acid by formation of monomer before. Lactic acid is converted into lactide in two stages, polycondensation and depolymerization. Yield lactide will determine the molecular weight which produced. This study is to optimize the lactide production from lactic acid 90% by the variations of temperature (190-220°C), vacuum pressure (5-15 cmHg), and zinc acetate catalyst (0,3-0,6% w/w). As the temperature, vacuum pressure, and catalyst is increased, lactide that is produced also increases. Optimum condition of lactide production is obtained by Response surface methodology at the temperature 220°C, catalyst 0,45%w/w, and 10 cmHg in vacuum pressure. Equation or model from this study by using RSM is yield lactide = -258,75 + 7,79A + 2,90B + 3,51C + 0,48AB - 0,06AC – 3,97x10-3BC – 105,42A2 – 7,17B2– 0,10C2(A:catalyst; B:temperature; C:pressure).

Investigation on the Flexural Creep Stiffness Behavior of PC-ABS Material Processed by Fused Deposition Modeling Using Response Surface Definitive Screening Design

NASA Astrophysics Data System (ADS)

Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal

2017-03-01

The resistance of polymeric materials to time-dependent plastic deformation is an important requirement of the fused deposition modeling (FDM) design process, its processed products, and their application for long-term loading, durability, and reliability. The creep performance of the material and part processed by FDM is the fundamental criterion for many applications with strict dimensional stability requirements, including medical implants, electrical and electronic products, and various automotive applications. Herein, the effect of FDM fabrication conditions on the flexural creep stiffness behavior of polycarbonate-acrylonitrile-butadiene-styrene processed parts was investigated. A relatively new class of experimental design called "definitive screening design" was adopted for this investigation. The effects of process variables on flexural creep stiffness behavior were monitored, and the best suited quadratic polynomial model with high coefficient of determination ( R 2) value was developed. This study highlights the value of response surface definitive screening design in optimizing properties for the products and materials, and it demonstrates its role and potential application in material processing and additive manufacturing.

Formulation of a minimal nutritional medium for enhanced lipid productivity in Chlorella sp. and Botryococcus sp. using response surface methodology.

PubMed

Vishwakarma, Rashi; Dhar, Dolly Wattal; Pabbi, Sunil

2018-03-01

Chlorella sp. MCC 7 and Botryococcus sp. MCC 31 were investigated to enable large-scale biodiesel production from minimal constituents in the growth medium. Response surface methodology (RSM) was used to maximise the biomass productivity and lipid yield using only nitrogen (N), phosphorus (P) and potassium (K) as urea, single super phosphate and muriate of potash. The optimum values were 0.42 g/L nitrogen; 0.14 g/L phosphorus and 0.22 g/L potassium for Chlorella sp.; and 0.46 g/L; 0.14 g/L and 0.25 g/L for Botryococcus sp. Lipid yield of 42% for Chlorella sp. and 52% in Botryococcus sp. was observed. An enhancement in lipid yield by approximately 55% for Chlorella sp. and 73% for Botryococcus sp. was registered as compared to original nutrient medium. Fourier transform infrared (FTIR) analysis of extracted lipids revealed characteristic bands for triglycerides. This study provided utilisation of a practicable nutrient recipe in the form of N, P, K input for enhanced lipid yield from the selected microalgal strains.

Continuous fermentation of food waste leachate for the production of volatile fatty acids and potential as a denitrification carbon source.

PubMed

Kim, Hakchan; Kim, Jaai; Shin, Seung Gu; Hwang, Seokhwan; Lee, Changsoo

2016-05-01

This study investigated the simultaneous effects of hydraulic retention time (HRT) and pH on the continuous production of VFAs from food waste leachate using response surface analysis. The response surface approximations (R(2)=0.895, p<0.05) revealed that pH has a dominant effect on the specific VFA production (PTVFA) within the explored space (1-4-day HRT, pH 4.5-6.5). The estimated maximum PTVFA was 0.26g total VFAs/g CODf at 2.14-day HRT and pH 6.44, and the approximation was experimentally validated by running triplicate reactors under the estimated optimum conditions. The mixture of the filtrates recovered from these reactors was tested as a denitrification carbon source and demonstrated superior performance in terms of reaction rate and lag length relative to other chemicals, including acetate and methanol. The overall results provide helpful information for better design and control of continuous fermentation for producing waste-derived VFAs, an alternative carbon source for denitrification. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical optimization and anticancer activity of a red pigment isolated from Streptomyces sp. PM4

PubMed Central

Karuppiah, Valliappan; Aarthi, Chandramohan; Sivakumar, Kannan; Kannan, Lakshmanan

2013-01-01

Objective To enhance the pigment production by Streptomyces sp. PM4 for evaluating its anticancer activity. Methods Response surface methodology was employed to enhance the production of red pigment from Streptomyces sp. PM4. Optimized pigment was purified and evaluated for the anticancer activity against HT1080, Hep2, HeLa and MCF7 cell lines by MTT assay. Results Based on the response surface methodology, it could be concluded that maltose (4.06 g), peptone (7.34 g), yeast extract (4.34 g) and tyrosine (2.89 g) were required for the maximum production of pigment (1.68 g/L) by the Streptomyces sp. PM4. Optimization of the medium with the above tested features increased the pigment yield by 4.6 fold. Pigment showed the potential anticancer activity against HT1080, HEp-2, HeLa and MCF-7cell lines with the IC50 value of 18.5, 15.3, 9.6 and 8.5 respectively. Conclusions The study revealed that the maximum amount of pigment could be produced to treat cancer. PMID:23905024

Statistical optimization and anticancer activity of a red pigment isolated from Streptomyces sp. PM4.

PubMed

Karuppiah, Valliappan; Aarthi, Chandramohan; Sivakumar, Kannan; Kannan, Lakshmanan

2013-08-01

To enhance the pigment production by Streptomyces sp. PM4 for evaluating its anticancer activity. Response surface methodology was employed to enhance the production of red pigment from Streptomyces sp. PM4. Optimized pigment was purified and evaluated for the anticancer activity against HT1080, Hep2, HeLa and MCF7 cell lines by MTT assay. Based on the response surface methodology, it could be concluded that maltose (4.06 g), peptone (7.34 g), yeast extract (4.34 g) and tyrosine (2.89 g) were required for the maximum production of pigment (1.68 g/L) by the Streptomyces sp. PM4. Optimization of the medium with the above tested features increased the pigment yield by 4.6 fold. Pigment showed the potential anticancer activity against HT1080, HEp-2, HeLa and MCF-7 cell lines with the IC50 value of 18.5, 15.3, 9.6 and 8.5 respectively. The study revealed that the maximum amount of pigment could be produced to treat cancer.

Application of Taguchi Design and Response Surface Methodology for Improving Conversion of Isoeugenol into Vanillin by Resting Cells of Psychrobacter sp. CSW4.

PubMed

Ashengroph, Morahem; Nahvi, Iraj; Amini, Jahanshir

2013-01-01

For all industrial processes, modelling, optimisation and control are the keys to enhance productivity and ensure product quality. In the current study, the optimization of process parameters for improving the conversion of isoeugenol to vanillin by Psychrobacter sp. CSW4 was investigated by means of Taguchi approach and Box-Behnken statistical design under resting cell conditions. Taguchi design was employed for screening the significant variables in the bioconversion medium. Sequentially, Box-Behnken design experiments under Response Surface Methodology (RSM) was used for further optimization. Four factors (isoeugenol, NaCl, biomass and tween 80 initial concentrations), which have significant effects on vanillin yield, were selected from ten variables by Taguchi experimental design. With the regression coefficient analysis in the Box-Behnken design, a relationship between vanillin production and four significant variables was obtained, and the optimum levels of the four variables were as follows: initial isoeugenol concentration 6.5 g/L, initial tween 80 concentration 0.89 g/L, initial NaCl concentration 113.2 g/L and initial biomass concentration 6.27 g/L. Under these optimized conditions, the maximum predicted concentration of vanillin was 2.25 g/L. These optimized values of the factors were validated in a triplicate shaking flask study and an average of 2.19 g/L for vanillin, which corresponded to a molar yield 36.3%, after a 24 h bioconversion was obtained. The present work is the first one reporting the application of Taguchi design and Response surface methodology for optimizing bioconversion of isoeugenol into vanillin under resting cell conditions.

Modelling the feedbacks between mass balance, ice flow and debris transport to predict the response to climate change of debris-covered glaciers in the Himalaya

NASA Astrophysics Data System (ADS)

Rowan, Ann V.; Egholm, David L.; Quincey, Duncan J.; Glasser, Neil F.

2015-11-01

Many Himalayan glaciers are characterised in their lower reaches by a rock debris layer. This debris insulates the glacier surface from atmospheric warming and complicates the response to climate change compared to glaciers with clean-ice surfaces. Debris-covered glaciers can persist well below the altitude that would be sustainable for clean-ice glaciers, resulting in much longer timescales of mass loss and meltwater production. The properties and evolution of supraglacial debris present a considerable challenge to understanding future glacier change. Existing approaches to predicting variations in glacier volume and meltwater production rely on numerical models that represent the processes governing glaciers with clean-ice surfaces, and yield conflicting results. We developed a numerical model that couples the flow of ice and debris and includes important feedbacks between debris accumulation and glacier mass balance. To investigate the impact of debris transport on the response of a glacier to recent and future climate change, we applied this model to a large debris-covered Himalayan glacier-Khumbu Glacier in Nepal. Our results demonstrate that supraglacial debris prolongs the response of the glacier to warming and causes lowering of the glacier surface in situ, concealing the magnitude of mass loss when compared with estimates based on glacierised area. Since the Little Ice Age, Khumbu Glacier has lost 34% of its volume while its area has reduced by only 6%. We predict a decrease in glacier volume of 8-10% by AD2100, accompanied by dynamic and physical detachment of the debris-covered tongue from the active glacier within the next 150 yr. This detachment will accelerate rates of glacier decay, and similar changes are likely for other debris-covered glaciers in the Himalaya.

Predicting biomaterial property-dendritic cell phenotype relationships from the multivariate analysis of responses to polymethacrylates

PubMed Central

Kou, Peng Meng; Pallassana, Narayanan; Bowden, Rebeca; Cunningham, Barry; Joy, Abraham; Kohn, Joachim; Babensee, Julia E.

2011-01-01

Dendritic cells (DCs) play a critical role in orchestrating the host responses to a wide variety of foreign antigens and are essential in maintaining immune tolerance. Distinct biomaterials have been shown to differentially affect the phenotype of DCs, which suggested that biomaterials may be used to modulate immune response towards the biologic component in combination products. The elucidation of biomaterial property-DC phenotype relationships is expected to inform rational design of immuno-modulatory biomaterials. In this study, DC response to a set of 12 polymethacrylates (pMAs) was assessed in terms of surface marker expression and cytokine profile. Principal component analysis (PCA) determined that surface carbon correlated with enhanced DC maturation, while surface oxygen was associated with an immature DC phenotype. Partial square linear regression, a multivariate modeling approach, was implemented and successfully predicted biomaterial-induced DC phenotype in terms of surface marker expression from biomaterial properties with R2prediction = 0.76. Furthermore, prediction of DC phenotype was effective based on only theoretical chemical composition of the bulk polymers with R2prediction = 0.80. These results demonstrated that immune cell response can be predicted from biomaterial properties, and computational models will expedite future biomaterial design and selection. PMID:22136715

Surface Nutrient Utilisation and Productivity During Glacial-Interglacial Periods from the Equatorial Indian Ocean

NASA Astrophysics Data System (ADS)

R, C. K.; Bhushan, R.; Agnihotri, R.; Sawlani, R.; Jull, A. J. T.

2016-12-01

Seawaters and underlying sediments off Sri Lanka provide a unique marine realm affected by both branches of Northern Indian Ocean i.e. Arabian Sea (AS) and Bay of Bengal (BOB). AS and BOB are known for their distinct response to southwest monsoon. AS experiencing mainly winds and upwelling while BOB receives precipitation driven surface runoff from the Indian sub-continent. Multiple proxies were measured on a radiocarbon dated sediment core raised off Sri Lanka; their down core variations were used to understand oceanic history (nutrient utilisation, surface productivity, nature of organic matter) spanning last glacial-interglacial cycle ( 26 to 2.5 ka BP). Variations in CaCO3, biogenic silica (BSi) and δ15N from 26 ka to 12.5 ka BP indicate the region was experiencing high surface productivity with probably reduced surface nutrient utilisation efficiency. Sedimentary δ15N depth profile is decoupled from down core variations of major productivity indices (e.g. CaCO3, OC), hinting plausibly partial utilization of nutrients in the mixed layer (photic zone). δ13C of OC and C/N (wt. ratio) clearly reveal the terrestrial origin of organic matter at 15 ka BP, a period known for witnessing onset of deglaciation in northern hemisphere. δ13C minimum at 9 ka BP indicates intense monsoonal activity during this time coinciding well with solar insolation (June) maximum of the northern hemisphere. With the onset of Holocene ( 11 ka BP), δ15N variations appear to correlate with BSi and Ba/Ti indicating enhanced utilization of available nutrients at surface. Suggesting surface productivity over the region was probably micro-nutrient limited. The increased inventory of terrestrial runoff in Holocene probably demonstrates enhanced carbon sequestration capability of the region.

Surface coal mine land reclamation using a dry flue gas desulfurization product: Short-term and long-term water responses.

PubMed

Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A

2015-09-01

Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.

The 2014/15 Warm Anomaly in the Southern California Current - Physical and Biological Responses

NASA Astrophysics Data System (ADS)

Ralf, G.

2016-02-01

The 2014/15 Warm Anomaly (WarmA) off Southern California manifested itself in the summer of 2014 as an anomalously warm surface layer in the Southern Calif. Bight with low concentrations of Chl a. This layer intensified in spatial extent, covering the entire CalCOFI surface area by the winter of 2015 with temperature anomalies 3 StDev larger than long-term averages. Concentrations of nutrients, phytoplankton biomass and rates of primary production were extremely low during the WarmA. The evolution of the WarmA as well as the 2015/16 El Niño with time will be compared to the evolution of the weak and strong El Niño's observed over the last 60 years. These events provide unique insights in the controls of phytoplankton biomass and production in the southern California Current System. Preliminary analyses suggest that the response of the phytoplankton community to the WarmA was consistent with responses to similar forcing during the prior decade. This presentation is based on data collected during the quarterly CalCOFI cruises by the CalCOFI and the CCE-LTER groups.

Optimization of Enzymatic Saccharification of Alkali Pretreated Parthenium sp. Using Response Surface Methodology

PubMed Central

Pandiyan, K.; Tiwari, Rameshwar; Singh, Surender; Nain, Pawan K. S.; Rana, Sarika; Arora, Anju; Singh, Shashi B.; Nain, Lata

2014-01-01

Parthenium sp. is a noxious weed which threatens the environment and biodiversity due to its rapid invasion. This lignocellulosic weed was investigated for its potential in biofuel production by subjecting it to mild alkali pretreatment followed by enzymatic saccharification which resulted in significant amount of fermentable sugar yield (76.6%). Optimization of enzymatic hydrolysis variables such as temperature, pH, enzyme, and substrate loading was carried out using central composite design (CCD) in response to surface methodology (RSM) to achieve the maximum saccharification yield. Data obtained from RSM was validated using ANOVA. After the optimization process, a model was proposed with predicted value of 80.08% saccharification yield under optimum conditions which was confirmed by the experimental value of 85.80%. This illustrated a good agreement between predicted and experimental response (saccharification yield). The saccharification yield was enhanced by enzyme loading and reduced by temperature and substrate loading. This study reveals that under optimized condition, sugar yield was significantly increased which was higher than earlier reports and promises the use of Parthenium sp. biomass as a feedstock for bioethanol production. PMID:24900917

COMPARISON OF HYDROLOGIC RESPONSES AT DIFFERENT WATERSHED SCALES

EPA Science Inventory

Land surface hydrology controls runoff production and the associated transport of sediments, and a wide variety of anthropogenic organic chemicals, and nutrients from upland landscape areas and hillslopes to streams and other water bodies. Based on interactions between landscape ...

78 FR 37218 - Agency Information Collection Activities OMB Responses

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-20

... the Paperwork Reduction Act (44 U.S.C. 3501 et seq.). An agency may not conduct or sponsor, and a... 2044.05; NESHAP for Plastic Parts and Products Surface Coating; 40 CFR part 63, subparts A and PPPP...

IPL Processing of the Viking Orbiter Images of Mars

NASA Technical Reports Server (NTRS)

Ruiz, R. M.; Elliott, D. A.; Yagi, G. M.; Pomphrey, R. B.; Power, M. A.; Farrell, W., Jr.; Lorre, J. J.; Benton, W. D.; Dewar, R. E.; Cullen, L. E.

1977-01-01

The Viking orbiter cameras returned over 9000 images of Mars during the 6-month nominal mission. Digital image processing was required to produce products suitable for quantitative and qualitative scientific interpretation. Processing included the production of surface elevation data using computer stereophotogrammetric techniques, crater classification based on geomorphological characteristics, and the generation of color products using multiple black-and-white images recorded through spectral filters. The Image Processing Laboratory of the Jet Propulsion Laboratory was responsible for the design, development, and application of the software required to produce these 'second-order' products.

Surface structure characterization of Aspergillus fumigatus conidia mutated in the melanin synthesis pathway and their human cellular immune response.

PubMed

Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A; Kaveri, Srini V; Kwon-Chung, Kyung J; Latgé, Jean-Paul; Beauvais, Anne

2014-08-01

In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Medium optimization for pyrroloquinoline quinone (PQQ) production by Methylobacillus sp. zju323 using response surface methodology and artificial neural network-genetic algorithm.

PubMed

Wei, Peilian; Si, Zhenjun; Lu, Yao; Yu, Qingfei; Huang, Lei; Xu, Zhinan

2017-08-09

Methylobacillus sp. zju323 was adopted to improve the biosynthesis of pyrroloquinoline quinone (PQQ) by systematic optimization of the fermentation medium. The Plackett-Burman design was implemented to screen for the key medium components for the PQQ production. CoCl 2  · 6H 2 O, ρ-amino benzoic acid, and MgSO 4  · 7H 2 O were found capable of enhancing the PQQ production most significantly. A five-level three-factor central composite design was used to investigate the direct and interactive effects of these variables. Both response surface methodology (RSM) and artificial neural network-genetic algorithm (ANN-GA) were used to predict the PQQ production and to optimize the medium composition. The results showed that the medium optimized by ANN-GA was better than that by RSM in maximizing PQQ production and the experimental PQQ concentration in the ANN-GA-optimized medium was improved by 44.3% compared with that in the unoptimized medium. Further study showed that this ANN-GA-optimized medium was also effective in improving PQQ production by fed-batch mode, reaching the highest PQQ accumulation of 232.0 mg/L, which was about 47.6% increase relative to that in the original medium. The present work provided an optimized medium and developed a fed-batch strategy which might be potentially applicable in industrial PQQ production.

Statistical optimization of culture conditions for bacterial cellulose production using Box-Behnken design.

PubMed

Bae, Sangok; Shoda, Makoto

2005-04-05

Culture conditions in a jar fermentor for bacterial cellulose (BC) production from A. xylinum BPR2001 were optimized by statistical analysis using Box-Behnken design. Response surface methodology was used to predict the levels of the factors, fructose (X1), corn steep liquor (CSL) (X2), dissolved oxygen (DO) (X3), and agar concentration (X4). Total 27 experimental runs by combination of each factor were carried out in a 10-L jar fermentor, and a three-dimensional response surface was generated to determine the effect of the factors and to find out the optimum concentration of each factor for maximum BC production and BC yield. The fructose and agar concentration highly influenced the BC production and BC yield. However, the optimum conditions according to changes in CSL and DO concentrations were predicted at almost central values of tested ranges. The predicted results showed that BC production was 14.3 g/L under the condition of 4.99% fructose, 2.85% CSL, 28.33% DO, and 0.38% agar concentration. On the other hand, BC yield was predicted in 0.34 g/g under the condition of 3.63% fructose, 2.90% CSL, 31.14% DO, and 0.42% agar concentration. Under optimized culture conditions, improvement of BC production and BC yield were experimentally confirmed, which increased 76% and 57%, respectively, compared to BC production and BC yield before optimizing the culture conditions. Copyright (c) 2005 Wiley Periodicals, Inc.

Surface enlargement factor of rumen papillae and expression of genes involved in dermatological diseases and their relationships with feed intake in beef steers

USDA-ARS?s Scientific Manuscript database

Feed costs make up the largest portion of the total cost to produce beef. One way to reduce this cost, thereby increasing profitability of beef production, is to improve feed efficiency. The rumen is responsible for digestion and absorption of nutrients and microbial by-products and may play a sig...

Nanotextured titanium surfaces stimulate spreading, migration, and growth of rat mast cells.

PubMed

Marcatti Amarú Maximiano, William; Marino Mazucato, Vivian; Tambasco de Oliveira, Paulo; Célia Jamur, Maria; Oliver, Constance

2017-08-01

Titanium is a biomaterial widely used in dental and orthopedic implants. Since tissue-implant interactions occur at the nanoscale level, nanotextured titanium surfaces may affect cellular activity and modulate the tissue response that occurs at the tissue-implant interface. Therefore, the characterization of diverse cell types in response to titanium surfaces with nanotopography is important for the rational design of implants. Mast cells are multifunctional cells of the immune system that release a range of chemical mediators involved in the inflammatory response that occurs at the tissue-implant interface. Therefore, the aim of this study was to investigate the effects of the nanotopography of titanium surfaces on the physiology of mast cells. The results show that the nanotopography of titanium surfaces promoted the spreading of mast cells, which was accompanied by the reorganization of the cytoskeleton. Also, the nanotopography of titanium surfaces enhanced cell migration and cell growth, but did not alter the number of adherent cells in first hours of culture or affect focal adhesions and mediator release. Thus, the results show that nanotopography of titanium surfaces can affect mast cell physiology, and represents an improved strategy for the rational production of surfaces that stimulate tissue integration with the titanium implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2150-2161, 2017. © 2017 Wiley Periodicals, Inc.

Multispectral, hyperspectral, and LiDAR remote sensing and geographic information fusion for improved earthquake response

NASA Astrophysics Data System (ADS)

Kruse, F. A.; Kim, A. M.; Runyon, S. C.; Carlisle, Sarah C.; Clasen, C. C.; Esterline, C. H.; Jalobeanu, A.; Metcalf, J. P.; Basgall, P. L.; Trask, D. M.; Olsen, R. C.

2014-06-01

The Naval Postgraduate School (NPS) Remote Sensing Center (RSC) and research partners have completed a remote sensing pilot project in support of California post-earthquake-event emergency response. The project goals were to dovetail emergency management requirements with remote sensing capabilities to develop prototype map products for improved earthquake response. NPS coordinated with emergency management services and first responders to compile information about essential elements of information (EEI) requirements. A wide variety of remote sensing datasets including multispectral imagery (MSI), hyperspectral imagery (HSI), and LiDAR were assembled by NPS for the purpose of building imagery baseline data; and to demonstrate the use of remote sensing to derive ground surface information for use in planning, conducting, and monitoring post-earthquake emergency response. Worldview-2 data were converted to reflectance, orthorectified, and mosaicked for most of Monterey County; CA. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data acquired at two spatial resolutions were atmospherically corrected and analyzed in conjunction with the MSI data. LiDAR data at point densities from 1.4 pts/m2 to over 40 points/ m2 were analyzed to determine digital surface models. The multimodal data were then used to develop change detection approaches and products and other supporting information. Analysis results from these data along with other geographic information were used to identify and generate multi-tiered products tied to the level of post-event communications infrastructure (internet access + cell, cell only, no internet/cell). Technology transfer of these capabilities to local and state emergency response organizations gives emergency responders new tools in support of post-disaster operational scenarios.

Phytotoxin production in Aspergillus terreus is regulated by independent environmental signals

PubMed Central

Gressler, Markus; Meyer, Florian; Heine, Daniel; Hortschansky, Peter; Hertweck, Christian; Brock, Matthias

2015-01-01

Secondary metabolites have a great potential as pharmaceuticals, but there are only a few examples where regulation of gene cluster expression has been correlated with ecological and physiological relevance for the producer. Here, signals, mediators, and biological effects of terrein production were studied in the fungus Aspergillus terreus to elucidate the contribution of terrein to ecological competition. Terrein causes fruit surface lesions and inhibits plant seed germination. Additionally, terrein is moderately antifungal and reduces ferric iron, thereby supporting growth of A. terreus under iron starvation. In accordance, the lack of nitrogen or iron or elevated methionine levels induced terrein production and was dependent on either the nitrogen response regulators AreA and AtfA or the iron response regulator HapX. Independent signal transduction allows complex sensing of the environment and, combined with its broad spectrum of biological activities, terrein provides a prominent example of adapted secondary metabolite production in response to environmental competition. DOI: http://dx.doi.org/10.7554/eLife.07861.001 PMID:26173180

Global vegetation productivity response to climatic oscillations during the satellite era.

PubMed

Gonsamo, Alemu; Chen, Jing M; Lombardozzi, Danica

2016-10-01

Climate control on global vegetation productivity patterns has intensified in response to recent global warming. Yet, the contributions of the leading internal climatic variations to global vegetation productivity are poorly understood. Here, we use 30 years of global satellite observations to study climatic variations controls on continental and global vegetation productivity patterns. El Niño-Southern Oscillation (ENSO) phases (La Niña, neutral, and El Niño years) appear to be a weaker control on global-scale vegetation productivity than previously thought, although continental-scale responses are substantial. There is also clear evidence that other non-ENSO climatic variations have a strong control on spatial patterns of vegetation productivity mainly through their influence on temperature. Among the eight leading internal climatic variations, the East Atlantic/West Russia Pattern extensively controls the ensuing year vegetation productivity of the most productive tropical and temperate forest ecosystems of the Earth's vegetated surface through directionally consistent influence on vegetation greenness. The Community Climate System Model (CCSM4) simulations do not capture the observed patterns of vegetation productivity responses to internal climatic variations. Our analyses show the ubiquitous control of climatic variations on vegetation productivity and can further guide CCSM and other Earth system models developments to represent vegetation response patterns to unforced variability. Several winter time internal climatic variation indices show strong potentials on predicting growing season vegetation productivity two to six seasons ahead which enables national governments and farmers forecast crop yield to ensure supplies of affordable food, famine early warning, and plan management options to minimize yield losses ahead of time. © 2016 John Wiley & Sons Ltd.

Macrophage responses to 316L stainless steel and cobalt chromium alloys with different surface topographies.

PubMed

Anderson, Jordan A; Lamichhane, Sujan; Mani, Gopinath

2016-11-01

The surface topography of a biomaterial plays a vital role in determining macrophage interactions and influencing immune response. In this study, we investigated the effect of smooth and microrough topographies of commonly used metallic biomaterials such as 316 L stainless steel (SS) and cobalt-chromium (CoCr) alloys on macrophage interactions. The macrophage adhesion was greater on CoCr compared to SS, irrespective of their topographies. The macrophage activation and the secretion of most pro-inflammatory cytokines (TNF-α, IL-6, and IP-10) were greater on microrough surfaces than on smooth surfaces by day-1. However, by day-2, the macrophage activation on smooth surfaces was also significantly increased up to the same level as observed on the microrough surfaces, with more amount of cytokines secreted. The secretion of anti-inflammatory cytokine (IL-10) was significantly increased from day-1 to day-2 on all the alloy surfaces with the effect most prominently observed on microrough surfaces. The production of nitric oxide by the macrophages did not show any major substrate-dependent effect. The foreign body giant cells formed by macrophages were least observed on the microrough surfaces of CoCr. Thus, this study demonstrated that the nature of material (SS or CoCr) and their surface topographies (smooth or microrough) strongly influence the macrophage responses. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2658-2672, 2016. © 2016 Wiley Periodicals, Inc.

Use of satellite images to determine surface-water cover during the flood event of September 13, 2013, in Lyons and western Longmont, Colorado

USGS Publications Warehouse

Cole, Christopher J.; Friesen, Beverly A.; Wilson, Earl M.; Wilds, Stanley R.; Noble, Suzanne M.

2015-01-01

This surface-water cover dataset was created as a timely representation of post-flood ground conditions to support response efforts. This dataset and all processed imagery and derived products were uploaded to the USGS Hazards Data Distribution System (HDDS) website (http://hddsexplorer.usgs.gov/uplift/hdds/) for distribution to those responding to the flood event.

One-year response of American sycamore (Platanus occidentalis L.) and black locust (Robinia pseudoacacia L.) to granular fertilizer applications on a reclaimed surface mine in eastern Kentucky

Treesearch

Josh Brinks; John Lhotka; Chris. Barton

2011-01-01

The establishment of intensively managed woody energy crops on reclaimed surface mine lands provides an opportunity to diversify domestic biomass sources, while increasing the productivity and economic value of underutilized land. Our objective is to test the effect of fertilization on the growth and biomass accumulation of American sycamore (Platanus...

Surface Nitrification: A Major Uncertainty in Marine N2O Emissions

NASA Technical Reports Server (NTRS)

Zamora, Lauren M.; Oschlies, Andreas

2014-01-01

The ocean is responsible for up to a third of total global nitrous oxide (N2O) emissions, but uncertainties in emission rates of this potent greenhouse gas are high (approaching 100%). Here we use a marine biogeochemical model to assess six major uncertainties in estimates of N2O production, thereby providing guidance in how future studies may most effectively reduce uncertainties in current and future marine N2O emissions. Potential surface N2O production from nitrification causes the largest uncertainty in N2O emissions (estimated up to approximately 1.6 Tg N/yr (sup -1) or 48% of modeled values), followed by the unknown oxygen concentration at which N2O production switches to N2O consumption (0.8 Tg N/yr (sup -1)or 24% of modeled values). Other uncertainties are minor, cumulatively changing regional emissions by less than 15%. If production of N2O by surface nitrification could be ruled out in future studies, uncertainties in marine N2O emissions would be halved.

Production of a cellulase-free alkaline xylanase from Bacillus pumilus MTCC 5015 by submerged fermentation and its application in biobleaching.

PubMed

Thomas, Leya; Sindhu, Raveendran; Binod, Parameswaran; Pandey, Ashok

2015-06-01

Here, we described the production of a cellulase-free alkaline xylanase from Bacillus pumilus MTCC 5015 by submerged fermentation and its application in biobleaching. Various process parameters affecting xylanase production by B. pumilus were optimized by adopting a Plackett-Burman design (PBD) as well as Response surface methodology (RSM). These statistical methods aid in improving the enzyme yield by analysing the individual crucial components of the medium. Maximum production was obtained with 4% yeast extract, 0.08% magnesium sulphate, 30 h of inoculum age, incubation temperature of 33.5 degrees C and pH 9.0. Under optimized conditions, the xylanase activity was 372 IU/ml. Media engineering improved a 5-fold increase in the enzyme production. Scanning electron microscopy (SEM) showed significant changes on the surface of xylanase treated pulps as a result of xylan hydrolysis. Increased roughness of paper carton fibres was apparent in scanning electron micrograph due to opening of the micro fibrils present on the surface by xylanase action. The untreated pulp did not show any such change. These results demonstrated that the B. pumilus MTCC 5015 xylanase was effective in bio-bleaching of paper carton.

PDC-TREM, a plasmacytoid dendritic cell-specific receptor, is responsible for augmented production of type I interferon.

PubMed

Watarai, Hiroshi; Sekine, Etsuko; Inoue, Sayo; Nakagawa, Ryusuke; Kaisho, Tsuneyasu; Taniguchi, Masaru

2008-02-26

Type I interferons (IFNs) derived from plasmacytoid dendritic cells (PDCs) are critical for antiviral responses; however, the mechanisms underlying their production remain unclear. We have identified a receptor, PDC-TREM, which is associated with Plexin-A1 (PlxnA1) on the PDC cell surface and is preferentially expressed after TLR-stimulation. Limited TLR signals induced PDC-TREM expression but failed to induce IFN-alpha production. However, when coupled with Sema6D, a ligand for Plexin-A1, limited TLR-stimulation resulted in PDC-TREM-mediated DAP12-dependent phosphorylation of phosphoinositide 3-kinase (PI3K) and extracellular regulated kinase (Erk) 1/2 at 6-9 h, and IFN-alpha was produced. Inhibition of PDC-TREM expression by pdctrem-shRNA, blocking of PDC-TREM-binding with PlxnA1 by PDC-TREM mAb, and DAP12 deficiency all resulted in greatly reduced PDC-TREM-dependent activation of signaling molecules and IFN-alpha production. Thus, PDC-TREM is responsible for IFN-alpha production, whereas TLR signals are essential for PDC-TREM expression.

Scaling of the entropy budget with surface temperature in radiative-convective equilibrium

NASA Astrophysics Data System (ADS)

Singh, Martin S.; O'Gorman, Paul A.

2016-09-01

The entropy budget of the atmosphere is examined in simulations of radiative-convective equilibrium with a cloud-system resolving model over a wide range of surface temperatures from 281 to 311 K. Irreversible phase changes and the diffusion of water vapor account for more than half of the irreversible entropy production within the atmosphere, even in the coldest simulation. As the surface temperature is increased, the atmospheric radiative cooling rate increases, driving a greater entropy sink that must be matched by greater irreversible entropy production. The entropy production resulting from irreversible moist processes increases at a similar fractional rate as the entropy sink and at a lower rate than that implied by Clausius-Clapeyron scaling. This allows the entropy production from frictional drag on hydrometeors and on the atmospheric flow to also increase with warming, in contrast to recent results for simulations with global climate models in which the work output decreases with warming. A set of approximate scaling relations is introduced for the terms in the entropy budget as the surface temperature is varied, and many of the terms are found to scale with the mean surface precipitation rate. The entropy budget provides some insight into changes in frictional dissipation in response to warming or changes in model resolution, but it is argued that frictional dissipation is not closely linked to other measures of convective vigor.

Operational marine products from Copernicus Sentinel-3 mission

NASA Astrophysics Data System (ADS)

Tomazic, Igor; Montagner, Francois; O'Carroll, Anne; Kwiatkowska, Ewa; Scharroo, Remko; Nogueira Loddo, Carolina; Martin-Puig, Cristina; Bonekamp, Hans; Lucas, Bruno; Dinardo, Salvatore; Dash, Prasanjit; Taberner, Malcolm; Coto Cabaleiro, Eva; Santacesaria, Vincenzo; Wilson, Hilary

2017-04-01

The first Copernicus Sentinel-3 satellite, Sentinel-3A, was launched in early 2016, with the mission to provide a consistent, long-term collection of marine and land data for operational analysis, forecasting and environmental and climate monitoring. The marine centre is part of the Sentinel-3 Payload Data Ground Segment, located at EUMETSAT. This centre together with the existing EUMETSAT facilities provides a routine centralised service for operational meteorology, oceanography, and other Sentinel-3 marine users as part of the European Commission's Copernicus programme. The EUMETSAT marine centre delivers operational Sea Surface Temperature, Ocean Colour and Sea Surface Topography data products based on the measurements from the Sea and Land Surface Temperature Radiometer (SLSTR), Ocean and Land Colour Instrument (OLCI) and Synthetic Aperture Radar Altimeter (SRAL), respectively, all aboard Sentinel-3. All products have been developed together with ESA and industry partners and EUMETSAT is responsible for the production, distribution, and future evolution of Level-2 marine products. We will give an overview of the scientific characteristics and algorithms of all marine Level-2 products, as well as instrument calibration and product validation results based on on-going Sentinel-3 Cal/Val activities. Information will be also provided about the current status of the product dissemination and the future evolutions that are envisaged. Also, we will provide information how to access Sentinel-3 data from EUMETSAT and where to look for further information.

Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes

PubMed Central

2012-01-01

Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could proceed via the ERAD pathway and through the proteasome. However, the amount of HBsAg did not show any significant decline during the cultivation revealing its general protection from proteolytic degradation. During the methanol fed-batch phase, induction of vacuolar proteases (e.g. strong increase of APR1) and constitutive autophagic processes were observed. Vacuolar enclosures were mainly found around peroxisomes and not close to HBsAg deposits and, thus, were most likely provoked by peroxisomal components damaged by reactive oxygen species generated by methanol oxidation. Conclusions In the methanol fed-batch phase P. pastoris is exposed to dual stress; stress resulting from methanol degradation and stress resulting from the production of the recombinant protein leading to the induction of oxidative stress and unfolded protein response pathways, respectively. Finally, the modest increase of methanol assimilatory enzymes compared to the strong increase of methanol dissimilatory enzymes suggests here a potential to increase methanol incorporation into biomass/product through metabolic enhancement of the methanol assimilatory pathway. PMID:22873405

In vitro cellular responses to silicon carbide nanoparticles: impact of physico-chemical features on pro-inflammatory and pro-oxidative effects

NASA Astrophysics Data System (ADS)

Pourchez, Jérémie; Forest, Valérie; Boumahdi, Najih; Boudard, Delphine; Tomatis, Maura; Fubini, Bice; Herlin-Boime, Nathalie; Leconte, Yann; Guilhot, Bernard; Cottier, Michèle; Grosseau, Philippe

2012-10-01

Silicon carbide is an extremely hard, wear resistant, and thermally stable material with particular photoluminescence and interesting biocompatibility properties. For this reason, it is largely employed for industrial applications such as ceramics. More recently, nano-sized SiC particles were expected to enlarge their use in several fields such as composite supports, power electronics, biomaterials, etc. However, their large-scaled development is restricted by the potential toxicity of nanoparticles related to their manipulation and inhalation. This study aimed at synthesizing (by laser pyrolysis or sol-gel methods), characterizing physico-chemical properties of six samples of SiC nanopowders, then determining their in vitro biological impact(s). Using a macrophage cell line, toxicity was assessed in terms of cell membrane damage (LDH release), inflammatory effect (TNF-α production), and oxidative stress (reactive oxygen species generation). None of the six samples showed cytotoxicity while remarkable pro-oxidative reactions and inflammatory response were recorded, whose intensity appears related to the physico-chemical features of nano-sized SiC particles. In vitro data clearly showed an impact of the extent of nanoparticle surface area and the nature of crystalline phases (α-SiC vs. β-SiC) on the TNF-α production, a role of surface iron on free radical release, and of the oxidation state of the surface on cellular H2O2 production.

Methods for Recovering Microorganisms from Solid Surfaces Used in the Food Industry: A Review of the Literature

PubMed Central

Ismaïl, Rached; Aviat, Florence; Michel, Valérie; Le Bayon, Isabelle; Gay-Perret, Perrine; Kutnik, Magdalena; Fédérighi, Michel

2013-01-01

Various types of surfaces are used today in the food industry, such as plastic, stainless steel, glass, and wood. These surfaces are subject to contamination by microorganisms responsible for the cross-contamination of food by contact with working surfaces. The HACCP-based processes are now widely used for the control of microbial hazards to prevent food safety issues. This preventive approach has resulted in the use of microbiological analyses of surfaces as one of the tools to control the hygiene of products. A method of recovering microorganisms from different solid surfaces is necessary as a means of health prevention. No regulation exists for surface microbial contamination, but food companies tend to establish technical specifications to add value to their products and limit contamination risks. The aim of this review is to present the most frequently used methods: swabbing, friction or scrubbing, printing, rinsing or immersion, sonication and scraping or grinding and describe their advantages and drawbacks. The choice of the recovery method has to be suitable for the type and size of the surface tested for microbiological analysis. Today, quick and cheap methods have to be standardized and especially easy to perform in the field. PMID:24240728

Methods for recovering microorganisms from solid surfaces used in the food industry: a review of the literature.

PubMed

Ismaïl, Rached; Aviat, Florence; Michel, Valérie; Le Bayon, Isabelle; Gay-Perret, Perrine; Kutnik, Magdalena; Fédérighi, Michel

2013-11-14

Various types of surfaces are used today in the food industry, such as plastic, stainless steel, glass, and wood. These surfaces are subject to contamination by microorganisms responsible for the cross-contamination of food by contact with working surfaces. The HACCP-based processes are now widely used for the control of microbial hazards to prevent food safety issues. This preventive approach has resulted in the use of microbiological analyses of surfaces as one of the tools to control the hygiene of products. A method of recovering microorganisms from different solid surfaces is necessary as a means of health prevention. No regulation exists for surface microbial contamination, but food companies tend to establish technical specifications to add value to their products and limit contamination risks. The aim of this review is to present the most frequently used methods: swabbing, friction or scrubbing, printing, rinsing or immersion, sonication and scraping or grinding and describe their advantages and drawbacks. The choice of the recovery method has to be suitable for the type and size of the surface tested for microbiological analysis. Today, quick and cheap methods have to be standardized and especially easy to perform in the field.

Roughness topographical effects on mean momentum and stress budgets in developed turbulent channel flows

NASA Astrophysics Data System (ADS)

Aghaei Jouybari, Mostafa; Yuan, Junlin

2017-11-01

Direct numerical simulations of turbulent channel flows are carried out over two surfaces: a synthesized sand-grain surface and a realistic turbine roughness that is characterized by more prominent large-scale surface features. To separate the effects of wall-normal variation of the roughness area fraction from the (true) variation of flow statistics, the governing equations are area-averaged using intrinsic averaging, contrary to the usually practice based on the total area (i.e., superficial averaging). Additional terms appear in the mean-momentum equation resulted from the wall-normal variation of the solid fraction and play a role in the near-wall balance. Results from surfaces with a step solidity function (e.g., cubes) will also be discussed. Compared to the sand grains, the turbine surface generates stronger form-induced fluctuations, despite weaker dispersive shear stress. This is associated with more significant form-induced productions (comparable to shear production) in Reynolds stress budgets, weaker pressure work, and, consequently, more anisotropic redistribution of turbulent kinetic energy in the roughness sublayer, which potentially leads to different turbulent responses between the two surfaces in non-equilibrium flows.

Photosynthetic oxygen production in a warmer ocean: the Sargasso Sea as a case study.

PubMed

Richardson, Katherine; Bendtsen, Jørgen

2017-09-13

Photosynthetic O 2 production can be an important source of oxygen in sub-surface ocean waters especially in permanently stratified oligotrophic regions of the ocean where O 2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global ocean and their extent is expected to increase in a warmer ocean. Thus, predicting future ocean oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen production to a warmer ocean. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen production in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O 2 and examine how it may be influenced in a warmer ocean. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O 2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen production at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q 10  = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative production of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen production. As POM/DOM production is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O 2 production in a warmer ocean.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

Photosynthetic oxygen production in a warmer ocean: the Sargasso Sea as a case study

NASA Astrophysics Data System (ADS)

Richardson, Katherine; Bendtsen, Jørgen

2017-08-01

Photosynthetic O2 production can be an important source of oxygen in sub-surface ocean waters especially in permanently stratified oligotrophic regions of the ocean where O2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global ocean and their extent is expected to increase in a warmer ocean. Thus, predicting future ocean oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen production to a warmer ocean. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen production in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O2 and examine how it may be influenced in a warmer ocean. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen production at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q10 = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative production of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen production. As POM/DOM production is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O2 production in a warmer ocean. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

Non-invasive, in vitro analysis of islet insulin production enabled by an optical porous silicon biosensor.

PubMed

Chhasatia, Rinku; Sweetman, Martin J; Harding, Frances J; Waibel, Michaela; Kay, Tom; Thomas, Helen; Loudovaris, Thomas; Voelcker, Nicolas H

2017-05-15

A label-free porous silicon (pSi) based, optical biosensor, using both an antibody and aptamer bioreceptor motif has been developed for the detection of insulin. Two parallel biosensors were designed and optimised independently, based on each bioreceptor. Both bioreceptors were covalently attached to a thermally hydrosilylated pSi surface though amide coupling, with unreacted surface area rendered stable and low fouling by incorporation of PEG moieties. The insulin detection ability of each biosensor was determined using interferometric reflectance spectroscopy, using a range of different media both with and without serum. Sensing performance was compared in terms of response value, response time and limit of detection (LOD) for each platform. In order to demonstrate the capability of the best performing biosensor to detect insulin from real samples, an in vitro investigation with the aptamer-modified surface was performed. This biosensor was exposed to buffer conditioned by glucose-stimulated human islets, with the result showing a positive response and a high degree of selectivity towards insulin capture. The obtained results correlated well with the ELISA used in the clinic for assaying glucose-stimulated insulin release from donor islets. We anticipate that this type of sensor can be applied as a rapid point-of-use biosensor to assess the quality of donor islets in terms of their insulin production efficiency, prior to transplantation. Copyright © 2017 Elsevier B.V. All rights reserved.

Synoptic events force biological productivity in Patagonian fjord ecosystems

NASA Astrophysics Data System (ADS)

Daneri, Giovanni

2016-04-01

The annual cycle of primary productivity of the Patagonian fjords has, to date, been described as a two phase system consisting of a short non productive winter phase (during June and July) and a productive phase extending from late winter (August) to autumn (May). Low levels of primary production, phytoplankton biomass and high concentrations of surface nutrients have been described as characterizing winter conditions while pulsed productivity events typifies the productivity pattern during the extended productive season. Pulsed productivity events characterize coastal waters where inorganic nutrients in surface layers are replenished following periods of intensive utilization by autotrophs. Freshwater input in Patagonian fjords in southern Chile (41-55°S) results in one of the largest estuarine regions worldwide. Here strong haline water column stratification prevents nutrient mixing to the surface layers thus potentially shutting off algal production. Our working hypothesis considered that in order to reconcile the observed pulsed productivity pattern, periodic breaking (associated to surface nutrient replenishment) and re-establishment of estuarine conditions (associated to water column stratification) would be required. Up to now however our understanding of the physical processes that control water column conditions in the Patagonian fjord area has been extremely limited. Here we present evidence linking the passage of synoptic low pressure fronts to pulsed productivity events in the Patagonian fjord area. These front controls and influence local processes of interaction between the fjord and the atmosphere generating a rapid water column response. In the specific case of the Puyuhuapi fjord we have been able to show that such synoptic fronts induce surface flow reversal and water column mixing. Phytoplankton blooming occurs after the passage of the synoptic front once calmer conditions prevail and estuarine conditions are re established. The occurrence of an extremely productive bloom of the dinoflagellate Heterocapsa sp. in July 2014, after the passage of a synoptic low pressure front provided, for the first time, strong evidence that phytoplankton blooming in the Patagonian fjord ecosystems is controlled by synoptic processes and that they are not limited by light as previously reported. This research was funded by COPAS Sur-Austral (PFB-31) and FONDECYT 1131063

Evaluating Surface Flux Results from CERES-FLASHFlux

NASA Technical Reports Server (NTRS)

Wilber, Anne C.; Stackhouse, Paul W., Jr.; Kratz, David P.; Gupta, Shashi K.; Sawaengphokhai, Parnchai K.

2015-01-01

The Fast Longwave and Shortwave Radiative Flux (FLASHFlux) data product was developed to provide a rapid release version of the Clouds and Earth's Radiant Energy System (CERES) results, which could be made available to the research and applications communities within one week of the satellite observations by exchanging some accuracy for speed of processing. Unlike standard CERES products, FLASHFlux does not maintain a long-term consistent record. Therefore the latest algorithm changes and input data can be incorporated into processing. FLASHFlux released Version3A (January 2013) and Version 3B (August 2014) which include the latest meteorological product from Global Modeling and Assimilation Office (GMAO), GEOS FP-IT (5.9.1), the latest spectral response functions and gains for the CERES instruments, and aerosol climatology based on the latest MATCH data. Version 3B included a slightly updated calibration and some changes to the surface albedo over snow/ice. Typically FLASHFlux does not reprocess earlier versions when a new version is released. The combined record of Time Interpolated Space Averaged (TISA) surface flux results from Versions3A and 3B for July 2012 to October 2015 have been compared to the ground-based measurements. The FLASHFlux results are also compared to two other CERES gridded products, SYN1deg and EBAF surface fluxes.

An analysis of the effect of biological and physical parameters of a wetlands grass biome on the spectral modeling of phytomass and primary productivity

NASA Technical Reports Server (NTRS)

Butera, M. K.; Frick, A.

1984-01-01

Aircraft simulated thematic mapper data and field data were acquired in the fall and spring to analyze the relationship of spectral response and biomass for the marsh grass Spartina patens. Regression results indicate no simple relationship exists for TMS spectral response and biomass with a high R sq. However, results show a consistent relationship between spectral response and the percent live vegetation (by weight) and percent interstitial standing surface water (by area) as independent variables. It is suggested that the reflected energy of a pixel represents a mixture of surface constituents. It is recommended that alternative remote sensors be employed to account for the pixel constituents of live and dead vegetation, litter, and standing water.

Improved fed-batch production of high-purity PHB (poly-3 hydroxy butyrate) by Cupriavidus necator (MTCC 1472) from sucrose-based cheap substrates under response surface-optimized conditions.

PubMed

Dey, Pinaki; Rangarajan, Vivek

2017-10-01

Experimental investigations were carried out for Cupriavidus necator (MTCC 1472)-based improved production of poly-3 hydroxy butyrate (PHB) through induced nitrogen limiting fed-batch cultivation strategies. Initially Plackett-Burman design and response surface methodology were implemented to optimize most influencing process parameters. With optimized process parameter values, continuous feeding strategies ware applied in a 5-l fermenter with table sugar concentration of 100 g/l, nitrogen concentration of 0.12 g/l for fed-batch fermentation with varying dilution rates of 0.02 and 0.046 1/h. To get enriched production of PHB, concentration of the sugar was further increased to 150 and 200 g/l in feeding. Maximum concentrations of PHB achieved were 22.35 and 23.07 g/l at those dilution rates when sugar concentration maintains at 200 g/l in feeding. At maximum concentration of PHB (23.07 g/l), productivity of 0.58 g/l h was achieved with maximum PHB accumulation efficiency up to 64% of the dry weight of biomass. High purity of PHB, close to medical grade was achieved after surfactant hypochlorite extraction method, and it was further confirmed by SEM, EDX, and XRD studies.

Optimization of artemisinin extraction from Artemisia annua L. with supercritical carbon dioxide + ethanol using response surface methodology.

PubMed

Ciftci, Ozan Nazim; Cahyadi, Jessica; Guigard, Selma E; Saldaña, Marleny D A

2018-05-13

Malaria is a high priority life-threatening public health concern in developing countries, and therefore there is a growing interest to obtain artemisinin for the production of artemisinin-based combination therapy products. In this study, artemisinin was extracted from the Artemisia annua L. plant using supercritical carbon dioxide (SC-CO 2 ) modified with ethanol. Response surface methodology based on central composite rotatable design was employed to investigate and optimize the extraction conditions of pressure (9.9-30 MPa), temperature (33-67°C), and co-solvent (ethanol, 0-12.6 wt.%). Optimum SC-CO 2 extraction conditions were found to be 30 MPa and 33°C without ethanol. Under optimized conditions, the predicted artemisinin yield was 1.09% whereas the experimental value was 0.71 ± 0.07%. Soxhlet extraction with hexane resulted in higher artemisinin yields and there was no significant difference in the purity of the extracts obtained with SC-CO 2 and Soxhlet extractions. Results indicated that SC-CO 2 and SC-CO 2 +ethanol extraction is a promising alternative for the extraction of artemisinin to eliminate the use of organic solvents, such as hexane, and produce extracts that can be used for the production of antimalarial products. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Response surface methodology: A non-conventional statistical tool to maximize the throughput of Streptomyces species biomass and their bioactive metabolites.

PubMed

Latha, Selvanathan; Sivaranjani, Govindhan; Dhanasekaran, Dharumadurai

2017-09-01

Among diverse actinobacteria, Streptomyces is a renowned ongoing source for the production of a large number of secondary metabolites, furnishing immeasurable pharmacological and biological activities. Hence, to meet the demand of new lead compounds for human and animal use, research is constantly targeting the bioprospecting of Streptomyces. Optimization of media components and physicochemical parameters is a plausible approach for the exploration of intensified production of novel as well as existing bioactive metabolites from various microbes, which is usually achieved by a range of classical techniques including one factor at a time (OFAT). However, the major drawbacks of conventional optimization methods have directed the use of statistical optimization approaches in fermentation process development. Response surface methodology (RSM) is one of the empirical techniques extensively used for modeling, optimization and analysis of fermentation processes. To date, several researchers have implemented RSM in different bioprocess optimization accountable for the production of assorted natural substances from Streptomyces in which the results are very promising. This review summarizes some of the recent RSM adopted studies for the enhanced production of antibiotics, enzymes and probiotics using Streptomyces with the intention to highlight the significance of Streptomyces as well as RSM to the research community and industries.

Use of response surface methodology in a fed-batch process for optimization of tricarboxylic acid cycle intermediates to achieve high levels of canthaxanthin from Dietzia natronolimnaea HS-1.

PubMed

Nasri Nasrabadi, Mohammad Reza; Razavi, Seyed Hadi

2010-04-01

In this work, we applied statistical experimental design to a fed-batch process for optimization of tricarboxylic acid cycle (TCA) intermediates in order to achieve high-level production of canthaxanthin from Dietzia natronolimnaea HS-1 cultured in beet molasses. A fractional factorial design (screening test) was first conducted on five TCA cycle intermediates. Out of the five TCA cycle intermediates investigated via screening tests, alfaketoglutarate, oxaloacetate and succinate were selected based on their statistically significant (P<0.05) and positive effects on canthaxanthin production. These significant factors were optimized by means of response surface methodology (RSM) in order to achieve high-level production of canthaxanthin. The experimental results of the RSM were fitted with a second-order polynomial equation by means of a multiple regression technique to identify the relationship between canthaxanthin production and the three TCA cycle intermediates. By means of this statistical design under a fed-batch process, the optimum conditions required to achieve the highest level of canthaxanthin (13172 + or - 25 microg l(-1)) were determined as follows: alfaketoglutarate, 9.69 mM; oxaloacetate, 8.68 mM; succinate, 8.51 mM. Copyright 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effect of mild-temperature H2O2 oxidation on solubilization and anaerobic digestion of waste activated sludge.

PubMed

Junga, Heejung; Kim, Jaai; Lee, Seungyong; Lee, Changsoo

2014-08-01

Efficient sludge management is among the most challenging issues in wastewater treatment today, and anaerobic digestion is regarded as a viable solution. Mild-temperature H202 oxidation was examined for enhanced solubilization and biogas production of waste activated sludge (WAS). The effects of pretreatment factors (i.e. temperature and H202 concentration) on the degree of WAS disintegration (DD) and biogas yield (BY) were assessed by response surface analysis within the design space of 60-90 degrees C and 0-200mM H202. Significant sludge disintegration (up to 23.0% DD) and visibly enhanced BY (up to 26.9%) were shown in the pretreatment trials. Two response surface models to describe how DD and BY respond to changes in the pretreatment conditions were successfully constructed (R2 > 0.95, p < 0.05). The models showed totally different response surface shapes, indicating the DD and BY were influenced by pretreatment conditions in very different ways. DD was dominantly affected by temperature and showed higher model responses at the high-temperature region, while the BY response peaked in the low-temperature and mid-level H2O2 region. This observation implies that the enhanced solubilization of WAS was not directly translated into an increase in biogas production. Our results showed that WAS can be efficiently disintegrated by H202 oxidation under mild-temperature conditions for enhanced anaerobic digestibility. Within the explored region of pretreatment conditions, the maximum BY was estimated to be 82.1 mL/gCODadded (32.8% greater than the untreated control) at (60.0 degrees C, 74.2 mM H2O2).

Cross-calibration of A.M. constellation sensors for long term monitoring of land surface processes

USGS Publications Warehouse

Meyer, D.; Chander, G.

2006-01-01

Data from multiple sensors must be used together to gain a more complete understanding of land surface processes at a variety of scales. Although higher-level products derived from different sensors (e.g., vegetation cover, albedo, surface temperature) can be validated independently, the degree to which these sensors and their products can be compared to one another is vastly improved if their relative spectro-radiometric responses are known. Most often, sensors are directly calibrated to diffuse solar irradiation or vicariously to ground targets. However, space-based targets are not traceable to metrological standards, and vicarious calibrations are expensive and provide a poor sampling of a sensor's full dynamic range. Cross-calibration of two sensors can augment these methods if certain conditions can be met: (1) the spectral responses are similar, (2) the observations are reasonably concurrent (similar atmospheric & solar illumination conditions), (3) errors due to misregistrations of inhomogeneous surfaces can be minimized (including scale differences), and (4) the viewing geometry is similar (or, some reasonable knowledge of surface bi-directional reflectance distribution functions is available). This study extends on a previous study of Terra/MODIS and Landsat/ETM+ cross calibration by including the Terra/ASTER and EO-1/ALI sensors, exploring the impacts of cross-calibrating sensors when conditions described above are met to some degree but not perfectly. Measures for spectral response differences and methods for cross calibrating such sensors are provided in this study. These instruments are cross calibrated using the Railroad Valley playa in Nevada. Best fit linear coefficients (slope and offset) are provided for ALI-to-MODIS and ETM+-to-MODIS cross calibrations, and root-mean-squared errors (RMSEs) and correlation coefficients are provided to quantify the uncertainty in these relationships. Due to problems with direct calibration of ASTER data, linear fits were developed between ASTER and ETM+ to assess the impacts of spectral bandpass differences between the two systems. In theory, the linear fits and uncertainties can be used to compare radiance and reflectance products derived from each instrument.

PEGylated graphene oxide elicits strong immunological responses despite surface passivation

NASA Astrophysics Data System (ADS)

Luo, Nana; Weber, Jeffrey K.; Wang, Shuang; Luan, Binquan; Yue, Hua; Xi, Xiaobo; Du, Jing; Yang, Zaixing; Wei, Wei; Zhou, Ruhong; Ma, Guanghui

2017-02-01

Engineered nanomaterials promise to transform medicine at the bio-nano interface. However, it is important to elucidate how synthetic nanomaterials interact with critical biological systems before such products can be safely utilized in humans. Past evidence suggests that polyethylene glycol-functionalized (PEGylated) nanomaterials are largely biocompatible and elicit less dramatic immune responses than their pristine counterparts. We here report results that contradict these findings. We find that PEGylated graphene oxide nanosheets (nGO-PEGs) stimulate potent cytokine responses in peritoneal macrophages, despite not being internalized. Atomistic molecular dynamics simulations support a mechanism by which nGO-PEGs preferentially adsorb onto and/or partially insert into cell membranes, thereby amplifying interactions with stimulatory surface receptors. Further experiments demonstrate that nGO-PEG indeed provokes cytokine secretion by enhancing integrin β8-related signalling pathways. The present results inform that surface passivation does not always prevent immunological reactions to 2D nanomaterials but also suggest applications for PEGylated nanomaterials wherein immune stimulation is desired.

Feasibility of Department of Defense Used Lubricating Oil Re-refining.

DTIC Science & Technology

1983-12-01

greater product selectivity (increasing cost effec- tiveness by tailoring the process to meet market demand ). In addition most processes have high yields...However, several issues were surfaced. The question of who in DLA is responsible for the administra- tion of a re-refining program must be resolved...Both the Property Disposal and Supply groups have a role. The Disposal group now has responsibility for .1%- iv -. d

Deglacial diatom production in the tropical North Atlantic driven by enhanced silicic acid supply

NASA Astrophysics Data System (ADS)

Hendry, Katharine R.; Gong, Xun; Knorr, Gregor; Pike, Jennifer; Hall, Ian R.

2016-03-01

Major shifts in ocean circulation are thought to be responsible for abrupt changes in temperature and atmospheric CO2 during the last deglaciation, linked to variability in meridional heat transport and deep ocean carbon storage. There is also widespread evidence for shifts in biological production during these times of deglacial CO2 rise, including enhanced diatom production in regions such as the tropical Atlantic. However, it remains unclear as to whether this diatom production was driven by enhanced wind-driven upwelling or density-driven vertical mixing, or by elevated thermocline concentrations of silicic acid supplied to the surface at a constant rate. Here, we demonstrate that silicic acid supply at depth in the NE Atlantic was enhanced during the abrupt climate events of the deglaciation. We use marine sediment archives to show that an increase in diatom production during abrupt climate shifts could only occur in regions of the NE Atlantic where the deep supply of silicic acid could reach the surface. The associated changes are indicative of enhanced regional wind-driven upwelling and/or weakened stratification due to circulation changes during phases of weakened Atlantic meridional overturning. Globally near-synchronous pulses of diatom production and enhanced thermocline concentrations of silicic acid suggest that widespread deglacial surface-driven breakdown of stratification, linked to changes in atmospheric circulation, had major consequences for biological productivity and carbon cycling.

Electron Microscopic Analysis of Surface Inorganic Substances on Oral and Combustible Tobacco Products.

PubMed

Halstead, Mary M; Watson, Clifford H; Pappas, R Steven

2015-01-01

Although quantitative trace toxic metal analyses have been performed on tobacco products, little has been published on inorganic particulate constituents on and inside the products. We analyzed these constituents using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The nature of SEM-EDS instrumentation makes it an ideal choice for inorganic particulate analyses and yields relevant information to potential exposures during consumption of oral tobacco products, and possibly as a consequence of smoking. Aluminum silicates, silica and calcium compounds were common inorganic particulate constituents of tobacco products. Aluminum silicates and silica from soil were found on external leaf surfaces. Phytolithic silica, found in the lumen of the plant leaf, is of biogenic origin. Calcium oxalate was also apparently of biogenic origin. Small mineral deposits on tobacco could have health implications. Minerals found on the surfaces of smokeless tobacco products could possibly abrade the oral mucosa and contribute to the oral inflammatory responses observed with smokeless tobacco product use. If micron and sub-micron size calcium particles on cigarette filler were transported in mainstream smoke, they could potentially induce a pulmonary irritant inflammation when inhaled. The transport of aluminum silicate and silica in smoke could potentially also contribute to chronic inflammatory disease. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Formulation development and optimization of a novel Cremophore EL-based nanoemulsion using ultrasound cavitation.

PubMed

Tang, Siah Ying; Manickam, Sivakumar; Wei, Tan Khang; Nashiru, Billa

2012-03-01

In the present study, response surface methodology (RSM) based on central composite design (CCD) was employed to investigate the influence of main emulsion composition variables, namely drug loading, oil content, emulsifier content as well as the effect of the ultrasonic operating parameters such as pre-mixing time, ultrasonic amplitude, and irradiation time on the properties of aspirin-loaded nanoemulsions. The two main emulsion properties studied as response variables were: mean droplet size and polydispersity index. The ultimate goal of the present work was to determine the optimum level of the six independent variables in which an optimal aspirin nanoemulsion with desirable properties could be produced. The response surface analysis results clearly showed that the variability of two responses could be depicted as a linear function of the content of main emulsion compositions and ultrasonic processing variables. In the present investigation, it is evidently shown that ultrasound cavitation is a powerful yet promising approach in the controlled production of aspirin nanoemulsions with smaller average droplet size in a range of 200-300 nm and with a polydispersity index (PDI) of about 0.30. This study proved that the use of low frequency ultrasound is of considerable importance in the controlled production of pharmaceutical nanoemulsions in the drug delivery system. Copyright © 2011 Elsevier B.V. All rights reserved.

Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode.

PubMed

Hauck, J; Völker, C; Wang, T; Hoppema, M; Losch, M; Wolf-Gladrow, D A

2013-12-01

Stratospheric ozone depletion and emission of greenhouse gases lead to a trend of the southern annular mode (SAM) toward its high-index polarity. The positive phase of the SAM is characterized by stronger than usual westerly winds that induce changes in the physical carbon transport. Changes in the natural carbon budget of the upper 100 m of the Southern Ocean in response to a positive SAM phase are explored with a coupled ecosystem-general circulation model and regression analysis. Previously overlooked processes that are important for the upper ocean carbon budget during a positive SAM period are identified, namely, export production and downward transport of carbon north of the polar front (PF) as large as the upwelling in the south. The limiting micronutrient iron is brought into the surface layer by upwelling and stimulates phytoplankton growth and export production but only in summer. This leads to a drawdown of carbon and less summertime outgassing (or more uptake) of natural CO 2 . In winter, biological mechanisms are inactive, and the surface ocean equilibrates with the atmosphere by releasing CO 2 . In the annual mean, the upper ocean region south of the PF loses more carbon by additional export production than by the release of CO 2 into the atmosphere, highlighting the role of the biological carbon pump in response to a positive SAM event.

Investigation of the Process Conditions for Hydrogen Production by Steam Reforming of Glycerol over Ni/Al2O3 Catalyst Using Response Surface Methodology (RSM)

PubMed Central

Ebshish, Ali; Yaakob, Zahira; Taufiq-Yap, Yun Hin; Bshish, Ahmed

2014-01-01

In this work; a response surface methodology (RSM) was implemented to investigate the process variables in a hydrogen production system. The effects of five independent variables; namely the temperature (X1); the flow rate (X2); the catalyst weight (X3); the catalyst loading (X4) and the glycerol-water molar ratio (X5) on the H2 yield (Y1) and the conversion of glycerol to gaseous products (Y2) were explored. Using multiple regression analysis; the experimental results of the H2 yield and the glycerol conversion to gases were fit to quadratic polynomial models. The proposed mathematical models have correlated the dependent factors well within the limits that were being examined. The best values of the process variables were a temperature of approximately 600 °C; a feed flow rate of 0.05 mL/min; a catalyst weight of 0.2 g; a catalyst loading of 20% and a glycerol-water molar ratio of approximately 12; where the H2 yield was predicted to be 57.6% and the conversion of glycerol was predicted to be 75%. To validate the proposed models; statistical analysis using a two-sample t-test was performed; and the results showed that the models could predict the responses satisfactorily within the limits of the variables that were studied. PMID:28788567

Southern Ocean Response to NADW Changes

NASA Technical Reports Server (NTRS)

Rind, David; Schmidt, G.; Russell, G.; deMenocal, P.; Hansen, James E. (Technical Monitor)

2000-01-01

The possibility of North Atlantic Deep Water (NADW) changes in both past and future climates has raised the issue of how the Southern Ocean would respond. Recent experiments with the GISS coupled atmosphere-ocean model have shown that a "bipolar see-saw" between NADW production and Antarctic Bottom Water (AABW) production in the Weddell Sea can occur in conjunction with freshening of the North Atlantic. However, this effect operates not through a slow ocean response but via a rapid atmospheric mechanism. As NADW reduces, colder temperatures in the North Atlantic, and Northern Hemisphere in general, are associated with higher surface pressure (increased atmospheric mass). Reduced mass in the Southern Hemisphere occurs in response, with lower pressure over the South Pole (an EOF #1 effect, the "high phase" of the Antarctic Oscillation).The lower pressure is associated with stronger west winds that generate an intensified Antarctic Circumpolar Current (ACC), which leads to longitudinal heat divergence in the South Atlantic (and heat convergence in the Southern Indian Ocean). Colder temperatures in the Weddell Sea region lead to sea ice growth, increased salinity and surface water density, and greater Weddell Sea Bottom Water production. Increased poleward transport of heat occurs in the South Atlantic in conjunction with increased bottom water production, but its convergence at high latitudes is not sufficient to offset the longitudinal heat divergence due to the intensified ACC. The colder temperatures at high latitudes in the South Atlantic increase the latitudinal temperature gradient, baroclinic instability, eddy energy and eddy poleward transport of momentum, helping to maintain the lower pressure over the pole in an interactive manner. The heat flux convergence in the Indian Ocean provides a warming tendency in that region, and overall global production of AABW remains unchanged. These results have implications for the interpretation of the ice core records of the last deglaciation, but may also be relevant for changes during the Holocene and perhaps even in response to increased CO2 forcing,

Improved production of tannase by Klebsiella pneumoniae using Indian gooseberry leaves under submerged fermentation using Taguchi approach.

PubMed

Kumar, Mukesh; Singh, Amrinder; Beniwal, Vikas; Salar, Raj Kumar

2016-12-01

Tannase (tannin acyl hydrolase E.C 3.1.1.20) is an inducible, largely extracellular enzyme that causes the hydrolysis of ester and depside bonds present in various substrates. Large scale industrial application of this enzyme is very limited owing to its high production costs. In the present study, cost effective production of tannase by Klebsiella pneumoniae KP715242 was studied under submerged fermentation using different tannin rich agro-residues like Indian gooseberry leaves (Phyllanthus emblica), Black plum leaves (Syzygium cumini), Eucalyptus leaves (Eucalyptus glogus) and Babul leaves (Acacia nilotica). Among all agro-residues, Indian gooseberry leaves were found to be the best substrate for tannase production under submerged fermentation. Sequential optimization approach using Taguchi orthogonal array screening and response surface methodology was adopted to optimize the fermentation variables in order to enhance the enzyme production. Eleven medium components were screened primarily by Taguchi orthogonal array design to identify the most contributing factors towards the enzyme production. The four most significant contributing variables affecting tannase production were found to be pH (23.62 %), tannin extract (20.70 %), temperature (20.33 %) and incubation time (14.99 %). These factors were further optimized with central composite design using response surface methodology. Maximum tannase production was observed at 5.52 pH, 39.72 °C temperature, 91.82 h of incubation time and 2.17 % tannin content. The enzyme activity was enhanced by 1.26 fold under these optimized conditions. The present study emphasizes the use of agro-residues as a potential substrate with an aim to lower down the input costs for tannase production so that the enzyme could be used proficiently for commercial purposes.

Tuning Product Selectivity for Aqueous CO2 Reduction with a Mn(bipyridine)-pyrene Catalyst Immobilized on a Carbon Nanotube Electrode

PubMed Central

2017-01-01

The development of high-performance electrocatalytic systems for the controlled reduction of CO2 to value-added chemicals is a key goal in emerging renewable energy technologies. The lack of selective and scalable catalysts in aqueous solution currently hampers the implementation of such a process. Here, the assembly of a [MnBr(2,2′-bipyridine)(CO)3] complex anchored to a carbon nanotube electrode via a pyrene unit is reported. Immobilization of the molecular catalyst allows electrocatalytic reduction of CO2 under fully aqueous conditions with a catalytic onset overpotential of η = 360 mV, and controlled potential electrolysis generated more than 1000 turnovers at η = 550 mV. The product selectivity can be tuned by alteration of the catalyst loading on the nanotube surface. CO was observed as the main product at high catalyst loadings, whereas formate was the dominant CO2 reduction product at low catalyst loadings. Using UV–vis and surface-sensitive IR spectroelectrochemical techniques, two different intermediates were identified as responsible for the change in selectivity of the heterogenized Mn catalyst. The formation of a dimeric Mn0 species at higher surface loading was shown to preferentially lead to CO formation, whereas at lower surface loading the electrochemical generation of a monomeric Mn-hydride is suggested to greatly enhance the production of formate. These results emphasize the advantages of integrating molecular catalysts onto electrode surfaces for enhancing catalytic activity while allowing excellent control and a deeper understanding of the catalytic mechanisms. PMID:28885841

Crosslinking of surface antibodies and Fc sub. gamma. receptors: Theory and application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wofsy, C.; Goldstein, B.

1991-03-15

In an immune response, the crosslinking of surface immunoglobulin (sIg) on B cells by multiply-bound ligand activates a range of cell responses, culminating in the production of antibody-secreting cells. However, when the crosslinking agent is itself an antibody, B cell activation is inhibited. Solution antibody (IgG) can bind simultaneously to sIg and to another cell surface receptor, Fc{sub {gamma}}R, co-crosslinking' the distinct receptors. Experiments point to co-crosslinking as the inhibitory signal. It is not clear how co-crosslinking inhibits B cell stimulation. The authors construct and analyze a mathematical model aimed at clarifying the nature and mechanisms of action of themore » separate cell signals controlling B cell responses to antibodies. Basophils and mast cells respond to the crosslinking of cell surface antibody by releasing histamine. Like B cells, basophils also express FC{sub {gamma}}R. They use their model to analyze new data on the effect of antibody-induced co-crosslinking of the two types of receptor on this family of cells. Predictions of the model indicate that an observed difference between the response patterns induced by antibodies and by antibody fragments that cannot bind to FC{sub {gamma}}R can be explained if co-crosslinking is neither inhibitory nor stimulatory in this system.« less

Impact of the exopolysaccharide layer on biofilms, adhesion and resistance to stress in Lactobacillus johnsonii FI9785.

PubMed

Dertli, Enes; Mayer, Melinda J; Narbad, Arjan

2015-02-04

The bacterial cell surface is a crucial factor in cell-cell and cell-host interactions. Lactobacillus johnsonii FI9785 produces an exopolysaccharide (EPS) layer whose quantity and composition is altered in mutants that harbour genetic changes in their eps gene clusters. We have assessed the effect of changes in EPS production on cell surface characteristics that may affect the ability of L. johnsonii to colonise the poultry host and exclude pathogens. Analysis of physicochemical cell surface characteristics reflected by Zeta potential and adhesion to hexadecane showed that an increase in EPS gave a less negative, more hydrophilic surface and reduced autoaggregation. Autoaggregation was significantly higher in mutants that have reduced EPS, indicating that EPS can mask surface structures responsible for cell-cell interactions. EPS also affected biofilm formation, but here the quantity of EPS produced was not the only determinant. A reduction in EPS production increased bacterial adhesion to chicken gut explants, but made the bacteria less able to survive some stresses. This study showed that manipulation of EPS production in L. johnsonii FI9785 can affect properties which may improve its performance as a competitive exclusion agent, but that positive changes in adhesion may be compromised by a reduction in the ability to survive stress.

Enhanced Osteoblast Response to Porosity and Resolution of Additively Manufactured Ti-6Al-4V Constructs with Trabeculae-Inspired Porosity

PubMed Central

Cheng, Alice; Humayun, Aiza; Schwartz, Zvi

2016-01-01

Abstract The addition of porosity to the traditionally used solid titanium metal implants has been suggested to more closely mimic the natural mechanical properties of bone and increase osseointegration in dental and orthopedic implants. The objective of this study was to evaluate cellular response to three-dimensional (3D) porous Ti-6Al-4V constructs fabricated by additive manufacturing using laser sintering with low porosity (LP), medium porosity (MP), and high porosity (HP) with low resolution (LR) and high resolution (HR) based on a computed tomography scan of human trabecular bone. After surface processing, construct porosity ranged from 41.0% to 76.1%, but all possessed micro-/nanoscale surface roughness and similar surface chemistry containing mostly Ti, O, and C. Biological responses (osteoblast differentiation, maturation, and local factor production) by MG63 osteoblast-like cells and normal human osteoblasts favored 3D than two-dimensional (2D) solid constructs. First, MG63 cells were used to assess differences in cell response to 2D compared to LR and HR porous 3D constructs. MG63 cells were sensitive to porosity resolution and exhibited increased osteocalcin (OCN), vascular endothelial growth factor (VEGF), osteoprotegerin (OPG), and bone morphogenetic protein 2 (BMP2) on HR 3D constructs than on 2D and LR 3D constructs. MG63 cells also exhibited porosity-dependent responses on HR constructs, with up to a 6.9-fold increase in factor production on LP-HR and MP-HR constructs than on HP-HR constructs. NHOsts were then used to validate biological response on HR constructs. NHOsts exhibited decreased DNA content and alkaline phosphatase activity and up to a 2.9-fold increase in OCN, OPG, VEGF, BMP2, and BMP4 on 3D HR constructs than on 2D controls. These results indicate that osteoblasts prefer a 3D architecture than a 2D surface and that osteoblasts are sensitive to the resolution of trabecular detail and porosity parameters of laser-sintered 3D Ti-6Al-4V constructs. PMID:28804735

Enhanced Osteoblast Response to Porosity and Resolution of Additively Manufactured Ti-6Al-4V Constructs with Trabeculae-Inspired Porosity.

PubMed

Cheng, Alice; Humayun, Aiza; Boyan, Barbara D; Schwartz, Zvi

2016-03-01

The addition of porosity to the traditionally used solid titanium metal implants has been suggested to more closely mimic the natural mechanical properties of bone and increase osseointegration in dental and orthopedic implants. The objective of this study was to evaluate cellular response to three-dimensional (3D) porous Ti-6Al-4V constructs fabricated by additive manufacturing using laser sintering with low porosity (LP), medium porosity (MP), and high porosity (HP) with low resolution (LR) and high resolution (HR) based on a computed tomography scan of human trabecular bone. After surface processing, construct porosity ranged from 41.0% to 76.1%, but all possessed micro-/nanoscale surface roughness and similar surface chemistry containing mostly Ti, O, and C. Biological responses (osteoblast differentiation, maturation, and local factor production) by MG63 osteoblast-like cells and normal human osteoblasts favored 3D than two-dimensional (2D) solid constructs. First, MG63 cells were used to assess differences in cell response to 2D compared to LR and HR porous 3D constructs. MG63 cells were sensitive to porosity resolution and exhibited increased osteocalcin (OCN), vascular endothelial growth factor (VEGF), osteoprotegerin (OPG), and bone morphogenetic protein 2 (BMP2) on HR 3D constructs than on 2D and LR 3D constructs. MG63 cells also exhibited porosity-dependent responses on HR constructs, with up to a 6.9-fold increase in factor production on LP-HR and MP-HR constructs than on HP-HR constructs. NHOsts were then used to validate biological response on HR constructs. NHOsts exhibited decreased DNA content and alkaline phosphatase activity and up to a 2.9-fold increase in OCN, OPG, VEGF, BMP2, and BMP4 on 3D HR constructs than on 2D controls. These results indicate that osteoblasts prefer a 3D architecture than a 2D surface and that osteoblasts are sensitive to the resolution of trabecular detail and porosity parameters of laser-sintered 3D Ti-6Al-4V constructs.

Cheating the Children.

ERIC Educational Resources Information Center

Rist, Marilee C.

1993-01-01

Schools are the victims, as bid-rigging scandals in the dairy-products industry surface in 13 states. School boards, in close cooperation with superintendents and district business managers, have the responsibility to detect bid-rigging or collusion. Offers guides for good business management and warning signs of bid-rigging. (MLF)

Near-surface soil property responses to forage production in a semiarid region

USDA-ARS?s Scientific Manuscript database

Integration of perennial plants in annual cropping systems can expand ecosystem service benefits to agricultural landscapes. Such benefits are frequently derived from changes to soil properties. Unfortunately, there is limited guidance for agricultural producers regarding the length of time needed...

Surface reactivity of volcanic ash from the eruption of Soufrière Hills volcano, Montserrat, West Indies with implications for health hazards.

PubMed

Horwell, Claire J; Fenoglio, Ivana; Vala Ragnarsdottir, K; Sparks, R Steve J; Fubini, Bice

2003-10-01

The fine-grained character of volcanic ash generated in the long-lived eruption of the Soufrière Hills volcano, Montserrat, West Indies, raises the issue of its possible health hazards. Surface- and free-radical production has been closely linked to bioreactivity of dusts within the lung. In this study, electron paramagnetic resonance (EPR) techniques have been used, for the first time, on volcanic ash to measure the production of radicals from the surface of particles. Results show that concentrations of hydroxyl radicals (HO*) in respirable ash are two to three times higher than a toxic quartz standard. The dome-collapse ash contains cristobalite, a crystalline silica polymorph that may cause adverse health effects. EPR experiments indicate, however, that cristobalite in the ash does not contribute to HO* generation. Our results show that the main cause of reactivity is removable divalent iron (Fe2+), which is present in abundance on the surfaces of the particles and is very reactive in the lung. Our analyses show that fresh ash generates more HO* than weathered ash (which has undergone progressive oxidation and leaching of iron from exposed surfaces), an effect replicated experimentally by incubating fresh ash in dilute acid. HO* production experiments also indicate that iron-rich silicate minerals are responsible for surface reactivity in the Soufrière Hills ash.

Response surface methodology for predicting quality characteristics of beef patties added with flaxseed and tomato paste.

PubMed

Valenzuela Melendres, M; Camou, J P; Torrentera Olivera, N G; Alvarez Almora, E; González Mendoza, D; Avendaño Reyes, L; González Ríos, H

2014-05-01

Response surface methodology was used to study the effect of flaxseed flour (FS) and tomato paste (TP) addition, from 0 to 10% and 0 to 20% respectively, on beef patty quality characteristics. The assessed quality characteristics were color (L, a, and b), pH and texture profile analysis (TPA). Also, sensory analysis was performed for the assessment of color, juiciness, firmness, and general acceptance. FS addition reduced L and a values and decreased weight loss of cooked products (P<0.05). An opposite effect was observed when TP was added (P<0.05). All TPA parameters decreased when percentages of FS and TP were increased in the formulation of beef patties. Furthermore, FS and TP addition adversely affected the sensory characteristics of the cooked product (P<0.05); nevertheless, all sensory characteristics evaluated had an acceptable score (>5.6). Thus FS and TP are ingredients that can be used in beef patty preparation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of succinic acid fermentation with Actinobacillus succinogenes by response surface methodology (RSM)*

PubMed Central

Zhang, Yun-jian; Li, Qiang; Zhang, Yu-xiu; Wang, Dan; Xing, Jian-min

2012-01-01

Succinic acid is considered as an important platform chemical. Succinic acid fermentation with Actinobacillus succinogenes strain BE-1 was optimized by central composite design (CCD) using a response surface methodology (RSM). The optimized production of succinic acid was predicted and the interactive effects between glucose, yeast extract, and magnesium carbonate were investigated. As a result, a model for predicting the concentration of succinic acid production was developed. The accuracy of the model was confirmed by the analysis of variance (ANOVA), and the validity was further proved by verification experiments showing that percentage errors between actual and predicted values varied from 3.02% to 6.38%. In addition, it was observed that the interactive effect between yeast extract and magnesium carbonate was statistically significant. In conclusion, RSM is an effective and useful method for optimizing the medium components and investigating the interactive effects, and can provide valuable information for succinic acid scale-up fermentation using A. succinogenes strain BE-1. PMID:22302423

Evaluation of the effect of yellow konjac flour-κ-carrageenan mixed gels and red koji rice extracts on the properties of restructured meat using response surface methodology.

PubMed

Widjanarko, Simon Bambang; Amalia, Qory; Hermanto, Mochamad Bagus; Mubarok, Ahmad Zaki

2018-05-01

In the present study, the effect of two independent variables, yellow konjac flour-κ-carrageenan (KFC) mixed gels and red koji rice (RKR) extracts for the development of restructured meat product, was investigated using central composite design of response surface methodology (RSM). The assessed physical characteristics were hardness, water holding capacity (WHC), and color (° hue ) of the restructured meat products. The second order regression models with high R 2 value were significantly fitted to predict the changes in hardness, WHC and color. The results showed that the predicted optimum formula of restructured meat were the addition of KFC mixed gels at 10.21% and RKR extracts at 6.11%. The experiments results validate these optimum formula and found to be not statistically different at 5% level. Thus, the RSM was successfully employed and can be used to optimize the formulation of restructured meat.

Optimization of thermophilic trans-isoprenyl diphosphate synthase expression in Escherichia coli by response surface methodology.

PubMed

Piccolomini, Angelica A; Fiabon, Alex; Borrotti, Matteo; De Lucrezia, Davide

2017-01-01

We optimized the heterologous expression of trans-isoprenyl diphosphate synthase (IDS), the key enzyme involved in the biosynthesis of trans-polyisoprene. trans-Polyisoprene is a particularly valuable compound due to its superior stiffness, excellent insulation, and low thermal expansion coefficient. Currently, trans-polyisoprene is mainly produced through chemical synthesis and no biotechnological processes have been established so far for its large-scale production. In this work, we employed D-optimal design and response surface methodology to optimize the expression of thermophilic enzymes IDS from Thermococcus kodakaraensis. The design of experiment took into account of six factors (preinduction cell density, inducer concentration, postinduction temperature, salt concentration, alternative carbon source, and protein inhibitor) and seven culture media (LB, NZCYM, TB, M9, Ec, Ac, and EDAVIS) at five different pH points. By screening only 109 experimental points, we were able to improve IDS production by 48% in close-batch fermentation. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Response surface methodology to simplify calculation of wood energy potency from tropical short rotation coppice species

NASA Astrophysics Data System (ADS)

Haqiqi, M. T.; Yuliansyah; Suwinarti, W.; Amirta, R.

2018-04-01

Short Rotation Coppice (SRC) system is an option to provide renewable and sustainable feedstock in generating electricity for rural area. Here in this study, we focussed on application of Response Surface Methodology (RSM) to simplify calculation protocols to point out wood chip production and energy potency from some tropical SRC species identified as Bauhinia purpurea, Bridelia tomentosa, Calliandra calothyrsus, Fagraea racemosa, Gliricidia sepium, Melastoma malabathricum, Piper aduncum, Vernonia amygdalina, Vernonia arborea and Vitex pinnata. The result showed that the highest calorific value was obtained from V. pinnata wood (19.97 MJ kg-1) due to its high lignin content (29.84 %, w/w). Our findings also indicated that the use of RSM for estimating energy-electricity of SRC wood had significant term regarding to the quadratic model (R2 = 0.953), whereas the solid-chip ratio prediction was accurate (R2 = 1.000). In the near future, the simple formula will be promising to calculate energy production easily from woody biomass, especially from SRC species.

Cellular basis for neonatally induced T-suppressor activity. Primary B cell maturation is blocked by suppressor-helper interactions restricted by loci on chromosome 12

PubMed Central

1985-01-01

The cellular mechanism and genetic restriction of neonatally induced HA- specific suppressor T (Ts) cells have been examined. The in vivo effect of these Ts cells on antibody production, primary B cell proliferation, B cell surface marker changes, and helper T (Th) cell priming during primary responses to HA have been determined. The results indicate that, although antigen-induced B cell proliferative responses and surface marker changes occur in the presence of Ts cells, differentiation to Ig secretion, and long-lived memory B cell production are prevented. Further, antigen-specific Th cell priming is completely ablated by Ts cells, suggesting that Ts act by preventing the delivery of Th signals required for both the later stages of primary B cell maturation, and the formation of memory B cell populations. Finally, in vivo cell mixing experiments using congenic mice indicate that this Ts-Th interaction is restricted by loci on mouse chromosome 12. PMID:2580040

Statistical optimization of process parameters for lipase-catalyzed synthesis of triethanolamine-based esterquats using response surface methodology in 2-liter bioreactor.

PubMed

Masoumi, Hamid Reza Fard; Basri, Mahiran; Kassim, Anuar; Abdullah, Dzulkefly Kuang; Abdollahi, Yadollah; Abd Gani, Siti Salwa; Rezaee, Malahat

2013-01-01

Lipase-catalyzed production of triethanolamine-based esterquat by esterification of oleic acid (OA) with triethanolamine (TEA) in n-hexane was performed in 2 L stirred-tank reactor. A set of experiments was designed by central composite design to process modeling and statistically evaluate the findings. Five independent process variables, including enzyme amount, reaction time, reaction temperature, substrates molar ratio of OA to TEA, and agitation speed, were studied under the given conditions designed by Design Expert software. Experimental data were examined for normality test before data processing stage and skewness and kurtosis indices were determined. The mathematical model developed was found to be adequate and statistically accurate to predict the optimum conversion of product. Response surface methodology with central composite design gave the best performance in this study, and the methodology as a whole has been proven to be adequate for the design and optimization of the enzymatic process.

Relating Radiative Fluxes on Arctic Sea Ice Area Using Arctic Observation and Reanalysis Integrated System (ArORIS)

NASA Astrophysics Data System (ADS)

Sledd, A.; L'Ecuyer, T. S.

2017-12-01

With Arctic sea ice declining rapidly and Arctic temperatures rising faster than the rest of the globe, a better understanding of the Arctic climate, and ice cover-radiation feedbacks in particular, is needed. Here we present the Arctic Observation and Reanalysis Integrated System (ArORIS), a dataset of integrated products to facilitate studying the Arctic using satellite, reanalysis, and in-situ datasets. The data include cloud properties, radiative fluxes, aerosols, meteorology, precipitation, and surface properties, to name just a few. Each dataset has uniform grid-spacing, time-averaging and naming conventions for ease of use between products. One intended use of ArORIS is to assess Arctic radiation and moisture budgets. Following that goal, we use observations from ArORIS - CERES-EBAF radiative fluxes and NSIDC sea ice fraction and area to quantify relationships between the Arctic energy balance and surface properties. We find a discernable difference between energy budgets for years with high and low September sea ice areas. Surface fluxes are especially responsive to the September sea ice minimum in months both leading up to September and the months following. In particular, longwave fluxes at the surface show increased sensitivity in the months preceding September. Using a single-layer model of solar radiation we also investigate the individual responses of surface and planetary albedos to changes in sea ice area. By partitioning the planetary albedo into surface and atmospheric contributions, we find that the atmospheric contribution to planetary albedo is less sensitive to changes in sea ice area than the surface contribution. Further comparisons between observations and reanalyses can be made using the available datasets in ArORIS.

Evaluation of Enterococcus faecium NRRL B-2354 as a Surrogate for Salmonella During Extrusion of Low-Moisture Food.

PubMed

Verma, Tushar; Wei, Xinyao; Lau, Soon Kiat; Bianchini, Andreia; Eskridge, Kent M; Subbiah, Jeyamkondan

2018-04-01

Salmonella in low-moisture foods is an emerging challenge due to numerous food product recalls and foodborne illness outbreaks. Identification of suitable surrogate is critical for process validation at industry level due to implementation of new Food Safety Modernization Act of 2011. The objective of this study was to evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during the extrusion of low-moisture food. Oat flour, a low-moisture food, was adjusted to different moisture (14% to 26% wet basis) and fat (5% to 15% w/w) contents and was inoculated with E. faecium NRRL B-2354. Inoculated material was then extruded in a lab-scale single-screw extruder running at different screw speeds (75 to 225 rpm) and different temperatures (75, 85, and 95 °C). A split-plot central composite 2nd order response surface design was used, with the central point replicated six times. The data from the selective media (m-Enterococcus agar) was used to build the response surface model for inactivation of E. faecium NRRL B-2354. Results indicated that E. faecium NRRL B-2354 always had higher heat resistance compared to Salmonella at all conditions evaluated in this study. However, the patterns of contour plots showing the effect of various product and process parameters on inactivation of E. faecium NRRL B-2354 was different from that of Salmonella. Although E. faecium NRRL B-2354 may be an acceptable surrogate for extrusion of low-moisture products due to higher resistance than Salmonella, another surrogate with similar inactivation behavior may be preferred and needs to be identified. Food Safety Modernization Act requires the food industry to validate processing interventions. This study validated extrusion processing and demonstrated that E. faecium NRRL B-2354 is an acceptable surrogate for extrusion of low-moisture products. The developed response surface model allows the industry to identify process conditions to achieve a desired lethality for their products based on composition. © 2018 Institute of Food Technologists®.

Optimum Design of Forging Process Parameters and Preform Shape under Uncertainties

NASA Astrophysics Data System (ADS)

Repalle, Jalaja; Grandhi, Ramana V.

2004-06-01

Forging is a highly complex non-linear process that is vulnerable to various uncertainties, such as variations in billet geometry, die temperature, material properties, workpiece and forging equipment positional errors and process parameters. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion and production risk. Identifying the sources of uncertainties, quantifying and controlling them will reduce risk in the manufacturing environment, which will minimize the overall cost of production. In this paper, various uncertainties that affect forging tool life and preform design are identified, and their cumulative effect on the forging process is evaluated. Since the forging process simulation is computationally intensive, the response surface approach is used to reduce time by establishing a relationship between the system performance and the critical process design parameters. Variability in system performance due to randomness in the parameters is computed by applying Monte Carlo Simulations (MCS) on generated Response Surface Models (RSM). Finally, a Robust Methodology is developed to optimize forging process parameters and preform shape. The developed method is demonstrated by applying it to an axisymmetric H-cross section disk forging to improve the product quality and robustness.

Removal of Zinc from Aqueous Solution by Optimized Oil Palm Empty Fruit Bunches Biochar as Low Cost Adsorbent

PubMed Central

Salleh, M. A. Mohd; Asady, Bahareh

2017-01-01

This study aims to produce optimized biochar from oil palm empty fruit bunches (OPEFB), as a green, low cost adsorbent for uptake of zinc from aqueous solution. The impact of pyrolysis conditions, namely, highest treatment temperature (HTT), heating rate (HR), and residence time (RT) on biochar yield and adsorption capacity towards zinc, was investigated. Mathematical modeling and optimization of independent variables were performed employing response surface methodology (RSM). HTT was found to be the most influential variable, followed by residence time and heating rate. Based on the central composite design (CCD), two quadratic models were developed to correlate three independent variables to responses. The optimum production condition for OPEFB biochar was found as follows: HTT of 615°C, HR of 8°C/min, and RT of 128 minutes. The optimum biochar showed 15.18 mg/g adsorption capacity for zinc and 25.49% of yield which was in agreement with the predicted values, satisfactory. Results of the characterization of optimum product illustrated well-developed BET surface area and porous structure in optimum product which favored its sorptive ability. PMID:28420949

Optimization of β-cyclodextrin-based extraction of antioxidant and anti-browning activities from thyme leaves by response surface methodology.

PubMed

Favre, Leonardo Cristian; Dos Santos, Cristina; López-Fernández, María Paula; Mazzobre, María Florencia; Buera, María Del Pilar

2018-11-01

Thyme (Thymus vulgaris) has been demonstrated to extend the shelf-life of food products, being also a potential source of bioactive compounds. The aim of this research was to optimize the ultrasound assisted extraction employing β-cyclodextrin aqueous solutions as no-contaminant technology and Response Surface Methodology to obtain thyme extracts with the maximum antioxidant capacity. The optimal extraction conditions were: a solution of β-ciclodextrin 15 mM, an ultrasonic treatment time of 5.9 min at a temperature of 36.6 °C. They resulted in an extract with a polyphenolic content of 189.3 mg GAE/mL, an antioxidant activity (DPPH) of 14.8 mg GAE/mL, and ferric reducing/antioxidant power (FRAP) of 3.3 mg GAE/mL. Interestingly, the extract demonstrated to inhibit the production of Maillard browning products and can be considered a potential antiglycant agent. The obtained data is important for developing eco-friendly technologies in order to obtain natural antioxidant extracts with a potential inhibitory capacity of Maillard glycation reaction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Screening of Actinomycetes from mangrove ecosystem for L-asparaginase activity and optimization by response surface methodology.

PubMed

Usha, Rajamanickam; Mala, Krishnaswami Kanjana; Venil, Chidambaram Kulandaisamy; Palaniswamy, Muthusamy

2011-01-01

Marine actinomycetes were isolated from sediment samples collected from Pitchavaram mangrove ecosystem situated along the southeast coast of India. Maximum actinomycete population was noted in rhizosphere region. About 38% of the isolates produced L-asparaginase. One potential strain KUA106 produced higher level of enzyme using tryptone glucose yeast extract medium. Based on the studied phenotypic characteristics, strain KUA106 was identified as Streptomyces parvulus KUA106. The optimization method that combines the Plackett-Burman design, a factorial design and the response surface method, which were used to optimize the medium for the production of L-asparaginase by Streptomycetes parvulus. Four medium factors were screened from eleven medium factors by Plackett-Burman design experiments and subsequent optimization process to find out the optimum values of the selected parameters using central composite design was performed. Asparagine, tryptone, d) extrose and NaCl components were found to be the best medium for the L-asparaginase production. The combined optimization method described here is the effective method for screening medium factors as well as determining their optimum level for the production of L-asparaginase by Streptomycetes parvulus KUAP106.

Utilization of response surface modeling to evaluate the effects of non-meat adjuncts and combinations of PSE and RFN pork on water holding capacity and cooked color in the production of boneless cured pork.

PubMed

Schilling, M W; Marriott, N G; Acton, J C; Anderson-Cook, C; Alvarado, C Z; Wang, H

2004-02-01

Boneless cured pork was produced from combinations of pale, soft, and exudative (PSE) and red, firm, and non-exudative (RFN) semimembranosus muscle. Response Surface Methodology was utilized to determine the effects of soy protein concentrate (SPC), sodium caseinate (SC), and modified food starch (MFS) on the water holding capacity and cooked color in a chunked and formed product. Fifteen ingredient combinations were replicated three times for each PSE and RFN combination giving 75 treatments per replication. Utilization of SPC decreased (P<0.01) cooking loss and redness while increasing (P<0.01) yellowness. MFS decreased (P<0.01) expressible moisture, and both MFS and SC increased (P<0.05) cooked redness while decreasing (P<0.01) cooked lightness. Product formulations using these adjuncts demonstrate potential to improve the water-holding capacity and cooked color in PSE as well as RFN pork. This research also demonstrated that diluting RFN pork with no more than 25% PSE pork permits the formation of a high quality boneless deli ham roll.

Production of antioxidant compounds of grape seed skin by fermentation and its optimization using response surface method

NASA Astrophysics Data System (ADS)

Andayani, D. G. S.; Risdian, C.; Saraswati, V.; Primadona, I.; Mawarda, P. C.

2017-03-01

Skins and seeds of grape are waste generated from food industry. These wastes contain nutrients of which able to be utilized as an important source for antioxidant metabolite production. Through an environmentally friendly process, natural antioxidant material was produced. This study aimed to generate antioxidant compounds by liquid fermentation. Optimization was carried out by using Schizosaccharomyces cerevisiae in Katu leaf substrate. Optimization variables through response surface methodology (RSM) were of sucrose concentration, skins and seeds of grape concentration, and pH. Results showed that the optimum conditions for antioxidant production were of 5 g/L sucrose, 5 g/L skins and seed at pH 5, respectively. The resulted antioxidant activity was of 1.62 mg/mL. Mathematical model of variance analysis using a second order polynomial corresponding to the resulted data for the antioxidant was of 20.70124 - 3.86997 A - 0.65996 B - 1.88367 C + 0.19634 A2 - 0.016638 B2 + 0.28848 C2 + 0.26980 AB - 0.068333 AC - 0.12367 BC. From the gained equation, the optimum yield from all variables was significant. Chemical analysis of the antioxidant was carried out using 2,2-Diphenyl-1-picrylhydrazyl (DPPH).

A Statistical approach to optimize the production of Polyhydroxyalkanoates from Wickerhamomyces anomalus VIT-NN01 using Response Surface Methodology.

PubMed

Ojha, Nupur; Das, Nilanjana

2018-02-01

Polyhydroxyalkanoates (PHAs) are three-level group of biodegradable polymers and attractive substitutes over conventional plastics to avoid the pollution problems. The yeast strain isolated from sugarcane juice, identified as Wickerhamomyces anomalus VIT-NN01, was used for the production of polyhydroxyalkanoates (PHA). Response surface methodology (RSM), three-level six variables Box-Behnken design (BBD), was employed to optimize the factors such as pH 8.0, temperature 37°C, sugarcane molasses (35g/L) supplemented with co-substrate palm oil (0.5%),corn steep liquor (2%) after a period of 96h of incubation for the maximum yield (19.50±0.3g/L) of PHA. It was well in close agreement with the predicted value obtained by RSM model yield (19.55±0.1g/L).Characterization of the extracted polymer was done using FTIR, GC-MS, XRD, TGA and AFM analysis. NMR spectroscopic analysis revealed that the biopolymer was poly (3-hydroxybutyrate-co-3-hydroxyvalerate), copolymer of PHA. This is the first report on optimization of PHA production using yeast strain isolated from natural sources. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of optimal conditions for production of highly crystalline nanocellulose with increased yield via novel Cr(III)-catalyzed hydrolysis: Response surface methodology.

PubMed

Chen, You Wei; Lee, Hwei Voon; Abd Hamid, Sharifah Bee

2017-12-15

For the first time, a highly efficient Cr(NO 3 ) 3 catalysis system was proposed for optimization the yield and crystallinity of nanocellulose end product. A five-level three-factor central composite design coupled with response surface methodology was employed to elucidate parameters interactions between three design factors, namely reaction temperature (x 1 ), reaction time (x 2 ) and concentration of Cr(NO 3 ) 3 (x 3 ) over a broad range of process conditions and determine the effect on crystallinity index and product yield. The developed models predicted the maximum nanocellulose yield of 87% at optimum process conditions of 70.6°C, 1.48h, and 0.48M Cr(NO 3 ) 3 . At these conditions, the obtained nanocellulose presented high crystallinity index (75.3%), spider-web-like interconnected network morphology with the average width of 31.2±14.3nm. In addition, the yielded nanocellulose rendered a higher thermal stability than that of original cellulosic source and expected to be widely used as reinforcement agent in bio-nanocomposites materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cryptic photosynthesis--extrasolar planetary oxygen without a surface biological signature.

PubMed

Cockell, Charles S; Kaltenegger, Lisa; Raven, John A

2009-09-01

On Earth, photosynthetic organisms are responsible for the production of virtually all the oxygen in the atmosphere. On land, vegetation reflects in the visible and leads to a "red edge," which developed about 450 million years ago on Earth and has been proposed as a biosignature for life on extrasolar planets. However, in many regions on Earth, particularly where surface conditions are extreme--in hot and cold deserts, for example--photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature to indicate life. The same is true of the assemblages of photosynthetic organisms at more than a few meters' depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We have linked geomicrobiology with observational astronomy by calculating the disk-averaged spectra of cryptic habitats and identifying detectable features on an exoplanet dominated by such a biota. The hypothetical cryptic photosynthesis worlds discussed here are Earth analogues that show detectable atmospheric biosignatures like our own planet but do not exhibit a discernable biological surface feature in the disc-averaged spectrum.

Trypanosoma congolense: proliferative responses and interleukin production in lymph node cells of infected cattle.

PubMed

Lutje, V; Mertens, B; Boulangé, A; Williams, D J; Authié, E

1995-09-01

T-cell-mediated immune responses to defined antigens of Trypanosoma congolense were measured in cattle undergoing primary infection. The antigens used were the variable surface glycoprotein and two invariant antigens, a 33-kDa cysteine protease (congopain) and a recombinant form of a 69-kDa heat-shock protein. Proliferative responses were highest during the second week postinfection and were detected in cells obtained from the lymph node draining the site of infection but not in peripheral blood mononuclear cells. Production of IL-2 and IFN-gamma was measured in supernatants from antigen-stimulated lymph node cell cultures. Expression of IL-2, IL-4, and IFN-gamma mRNA was detected in antigen-stimulated lymph node cells by reverse transcription-polymerase chain amplification.

Decision Support Tool Evaluation Report for Coral Reef Early Warning System (CREWS) Version 7.0

NASA Technical Reports Server (NTRS)

D'Sa, Eurico; Hall, Callie; Zanoni, Vicki; Holland, Donald; Blonski, Slawomir; Pagnutti, Mary; Spruce, Joseph P.

2004-01-01

The Coral Reef Early Warning System (CREWS) is operated by NOAA's Office of Oceanic and Atmospheric Research as part of its Coral Reef Watch program in response to the deteriorating global state of coral reef and related benthic ecosystems. In addition to sea surface temperatures (SSTs), the two most important parameters used by the CREWS network in generating coral reef bleaching alerts are 1) wind speed and direction and 2) photosynthetically available radiation (PAR). NASA remote sensing products that can enhance CREWS in these areas include SST and PAR products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and wind data from the Quick Scatterometer (QuikSCAT). CREWS researchers are also interested in chlorophyll, chromophoric dissolved organic matter (CDOM), and salinity. Chlorophyll and CDOM are directly available as NASA products, while rainfall (an available NASA product) can be used as a proxy for salinity. Other potential NASA inputs include surface reflectance products from MODIS, the Advanced Spaceborne Thermal Emission and Reflection Radiometer, and Landsat. This report also identifies NASA-supported ocean circulation models and products from future satellite missions that might enchance the CREWS DST.

Low RF Reflectivity Spacecraft Thermal Blanket by Using High-Impedance Surface Absorbers

NASA Astrophysics Data System (ADS)

Costa, F.; Monorchio, A.; Carrubba, E.; Zolesi, V.

2012-05-01

A technique for designing a low-RF reflectivity thermal blanket is presented. Multi-layer insulation (MLI) blankets are employed to stabilize the temperature on spacecraft unit but they can be responsible of passive intermodulation products and high-mutual coupling between antennas since they are realized with metallic materials. The possibility to replace the last inner layer of a MLI blanket with an ultra-thin absorbing layer made of high-impedance surface absorber is discussed.

Evaluation of the effect of nutrient ratios on biosurfactant production by Serratia marcescens using a Box-Behnken design.

PubMed

Roldán-Carrillo, T; Martínez-García, X; Zapata-Peñasco, I; Castorena-Cortés, G; Reyes-Avila, J; Mayol-Castillo, M; Olguín-Lora, P

2011-09-01

The strain SmSA, identified as Serratia marcescens and known as a biosurfactant producer, was isolated from hydrocarbon contaminated soil from Veracruz, México. The interactions among the C/N, C/Mg and C/Fe ratios have not been examined for this microorganism. In this work was evaluated the effect of these nutrients at three levels using a mineral medium with glucose as the carbon source. A Box-Behnken experimental design was utilised to maximise biosurfactant production, which was assessed by oil spreading and surface tension tests. The treatment with C/N=5, C/Fe=26,000 and C/Mg=30 showed the best result since the surface tension was reduced to 30 mN m(-1). The multiple regression and response surface analyses indicated that the interaction between C/N and C/Mg had the utmost effect on the reduction of surface tension and biosurfactant production. The conditions of the best treatment were used to scale up biosurfactant production in a 3L bioreactor giving a yield of 4.1 gL(-1) of pure biosurfactant. It was found that the biosurfactant was mainly produced in the exponential phase and decreased the surface tension to 31 mN m(-1). The contact between the biosurfactant with heavy oil (15° API) increased its displacement from 9.3 to 18 cm. Copyright © 2011 Elsevier B.V. All rights reserved.

Skin surface removal on breast microwave imagery using wavelet multiscale products

NASA Astrophysics Data System (ADS)

Flores-Tapia, Daniel; Thomas, Gabriel; Pistorius, Stephen

2006-03-01

In many parts of the world, breast cancer is the leading cause mortality among women and it is the major cause of cancer death, next only to lung cancer. In recent years, microwave imaging has shown its potential as an alternative approach for breast cancer detection. Although advances have improved the likelihood of developing an early detection system based on this technology, there are still limitations. One of these limitations is that target responses are often obscured by surface reflections. Contrary to ground penetrating radar applications, a simple reference subtraction cannot be easily applied to alleviate this problem due to differences in the breast skin composition between patients. A novel surface removal technique for the removal of these high intensity reflections is proposed in this paper. This paper presents an algorithm based on the multiplication of adjacent wavelet subbands in order to enhance target echoes while reducing skin reflections. In these multiscale products, target signatures can be effectively distinguished from surface reflections. A simple threshold is applied to the signal in the wavelet domain in order to eliminate the skin responses. This final signal is reconstructed to the spatial domain in order to obtain a focused image. The proposed algorithm yielded promising results when applied to real data obtained from a phantom which mimics the dielectric properties of breast, cancer and skin tissues.

First principles studies on the redox ability of (Ga(1-x)Zn(x))N(1-x)O(x) solid solutions and thermal reactions for H2 and O2 production on their surfaces.

PubMed

Du, Yaojun A; Chen, Yun-Wen; Kuo, Jer-Lai

2013-12-07

The (Ga1-xZnx)N1-xOx solid solution has been emerging as an effective photocatalyst for water splitting utilizing the visible solar spectrum, regarded as a host GaN bulk doped with ZnO impurities. H2 and O2 production occur simultaneously and stoichiometrically on the surface of (Ga1-xZnx)N1-xOx particles. In this work, we characterize the redox ability of (Ga1-xZnx)N1-xOx and find that a solid solution with a ZnO concentration of 0.125 < x < 0.250 is optimal for water splitting. This is consistent with the experimental finding that the maximum photocatalytic activity of (Ga1-xZnx)N1-xOx is achieved at x = 0.13. The thermal reactions of water splitting are modeled on both the GaN and an idealized (Ga1-xZnx)N1-xOx (101[combining macron]0) surface. The computed activation barriers allow us to gain some clues on the efficiency of water splitting on a specific photocatalyst surface. Our results suggest that the non-polar (101[combining macron]0) and polar (0001) surfaces may play different roles in water splitting, i.e., the (101[combining macron]0) surface is responsible for O2 production, while hydroxyl groups could dissociate on the (0001) surface.

Effects of colonization, luminescence, and autoinducer on host transcription during development of the squid-vibrio association.

PubMed

Chun, Carlene K; Troll, Joshua V; Koroleva, Irina; Brown, Bartley; Manzella, Liliana; Snir, Einat; Almabrazi, Hakeem; Scheetz, Todd E; Bonaldo, Maria de Fatima; Casavant, Thomas L; Soares, M Bento; Ruby, Edward G; McFall-Ngai, Margaret J

2008-08-12

The light-organ symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri offers the opportunity to decipher the hour-by-hour events that occur during the natural colonization of an animal's epithelial surface by its microbial partners. To determine the genetic basis of these events, a glass-slide microarray was used to characterize the light-organ transcriptome of juvenile squid in response to the initiation of symbiosis. Patterns of gene expression were compared between animals not exposed to the symbiont, exposed to the wild-type symbiont, or exposed to a mutant symbiont defective in either of two key characters of this association: bacterial luminescence or autoinducer (AI) production. Hundreds of genes were differentially regulated as a result of symbiosis initiation, and a hierarchy existed in the magnitude of the host's response to three symbiont features: bacterial presence > luminescence > AI production. Putative host receptors for bacterial surface molecules known to induce squid development are up-regulated by symbiont light production, suggesting that bioluminescence plays a key role in preparing the host for bacteria-induced development. Further, because the transcriptional response of tissues exposed to AI in the natural context (i.e., with the symbionts) differed from that to AI alone, the presence of the bacteria potentiates the role of quorum signals in symbiosis. Comparison of these microarray data with those from other symbioses, such as germ-free/conventionalized mice and zebrafish, revealed a set of shared genes that may represent a core set of ancient host responses conserved throughout animal evolution.

Effects of colonization, luminescence, and autoinducer on host transcription during development of the squid-vibrio association

PubMed Central

Chun, Carlene K.; Troll, Joshua V.; Koroleva, Irina; Brown, Bartley; Manzella, Liliana; Snir, Einat; Almabrazi, Hakeem; Scheetz, Todd E.; de Fatima Bonaldo, Maria; Casavant, Thomas L.; Soares, M. Bento; Ruby, Edward G.; McFall-Ngai, Margaret J.

2008-01-01

The light–organ symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri offers the opportunity to decipher the hour-by-hour events that occur during the natural colonization of an animal's epithelial surface by its microbial partners. To determine the genetic basis of these events, a glass-slide microarray was used to characterize the light-organ transcriptome of juvenile squid in response to the initiation of symbiosis. Patterns of gene expression were compared between animals not exposed to the symbiont, exposed to the wild-type symbiont, or exposed to a mutant symbiont defective in either of two key characters of this association: bacterial luminescence or autoinducer (AI) production. Hundreds of genes were differentially regulated as a result of symbiosis initiation, and a hierarchy existed in the magnitude of the host's response to three symbiont features: bacterial presence > luminescence > AI production. Putative host receptors for bacterial surface molecules known to induce squid development are up-regulated by symbiont light production, suggesting that bioluminescence plays a key role in preparing the host for bacteria-induced development. Further, because the transcriptional response of tissues exposed to AI in the natural context (i.e., with the symbionts) differed from that to AI alone, the presence of the bacteria potentiates the role of quorum signals in symbiosis. Comparison of these microarray data with those from other symbioses, such as germ-free/conventionalized mice and zebrafish, revealed a set of shared genes that may represent a core set of ancient host responses conserved throughout animal evolution. PMID:18682555

Design and simulation study of high frequency response for surface acoustic wave device by using CST software

NASA Astrophysics Data System (ADS)

Zakaria, M. R.; Hashim, U.; Amin, Mohd Hasrul I. M.; Ayub, R. Mat; Hashim, M. N.; Adam, T.

2015-05-01

This paper focuses on the enhancement and improvement of the Surface Acoustic Wave (SAW) device performance. Due to increased demand in the international market for biosensor product, the product must be emphasized in terms of quality. However, within the technological advances, demand for device with low cost, high efficiency and friendly-user preferred. Surface Acoustic Wave (SAW) device with the combination of pair electrode know as Interdigital Transducer (IDT) was fabricated on a piezoelectric substrate. The design of Interdigital Transducer (IDT) parameter is changes in several sizes and values for which it is able to provide greater efficiency in sensing sensitivity by using process simulation with CST STUDIO Suite software. In addition, Interdigital Transducer (IDT) parameters also changed to be created the products with a smaller size and easy to handle where it also reduces the cost of this product. Parameter values of an Interdigital Transducer (IDT) will be changed in the design is the total number of fingers pair, finger length, finger width and spacing, aperture and also the thickness of the Interdigital Transducer (IDT). From the result, the performance of the sensor is improved significantly after modification is done.

Cause-effect relationship between vocal fold physiology and voice production in a three-dimensional phonation model

PubMed Central

Zhang, Zhaoyan

2016-01-01

The goal of this study is to better understand the cause-effect relation between vocal fold physiology and the resulting vibration pattern and voice acoustics. Using a three-dimensional continuum model of phonation, the effects of changes in vocal fold stiffness, medial surface thickness in the vertical direction, resting glottal opening, and subglottal pressure on vocal fold vibration and different acoustic measures are investigated. The results show that the medial surface thickness has dominant effects on the vertical phase difference between the upper and lower margins of the medial surface, closed quotient, H1-H2, and higher-order harmonics excitation. The main effects of vocal fold approximation or decreasing resting glottal opening are to lower the phonation threshold pressure, reduce noise production, and increase the fundamental frequency. Increasing subglottal pressure is primarily responsible for vocal intensity increase but also leads to significant increase in noise production and an increased fundamental frequency. Increasing AP stiffness significantly increases the fundamental frequency and slightly reduces noise production. The interaction among vocal fold thickness, stiffness, approximation, and subglottal pressure in the control of F0, vocal intensity, and voice quality is discussed. PMID:27106298

Environmental Stress-mediated EPS Production Shape Microbial Activity on Various Hydrated Rough Surfaces

NASA Astrophysics Data System (ADS)

Wang, G.; Liu, L.; Chen, G.

2016-12-01

The complex environmental physical and chemical processes and interplay with the associating biological responses are keys to understanding the environmental microbiology ensconced in environmental remediation, water quality control, food safety, nutrient cycling, and etc., yet remain poorly understood. Using experimental micromodels, we study how environmental conditions (e.g., hydration fluctuation, nutrient limitation, pH variation, etc.) affect microbial extracellular polymeric substances (EPS) production and their configuration within various hydrated surfaces, and impacts on microbial motility, surface attachment, aggregation, and other bioremediation activities. To elucidate the potential mechanisms underlying the complex bio-physicochemical processes, we developed an individual-based and spatio-temporally resolved modeling platform that explicitly considers microscale aqueous-phase configuration and nutrient transport/diffusion and associated biophysical processes affecting individual microbial cell life history. We quantitatively explore the effects of the above microscale environmental processes on bio-physicochemical interactions affecting microbial growth, motility, surface attachment and aggregation, and shaping population interactions and functions. Simulation scenarios of microbial induced pollutant (e.g., roxarsone) biotransformation on various hydrated rough surfaces will also be present.

Assessment of pepper spray product potency in Asian and Caucasian forearm skin using transepidermal water loss, skin temperature and reflectance colorimetry.

PubMed

Pershing, Lynn K; Reilly, Christopher A; Corlett, Judy L; Crouch, Dennis J

2006-01-01

Historically, pepper spray product potency has been established using a taste test evaluation. A taste test is subjective and may not be appropriate for assessing pepper potency in skin. The current study evaluated chemically diverse pepper sprays in human forearm skin using three objective, noninvasive parameters: transepidermal water loss, skin surface temperature and erythema, as a means for assessing dermal pharmacology, toxicology and product potency. Five commercial pepper spray products containing various capsaicinoid analogs at various concentrations were evaluated in duplicate on volar forearms of six Caucasians and six Asians using a 10 min exposure. Mean surface skin temperature, transepidermal water loss results were highly variable and therefore did not demonstrate dose responsive behavior to increasing capsaicinoid concentrations. Erythema, as measured by increases in a* (reflected light in the red-to-green color spectrum) of the L*a*b* uniform color scale, was superior among parameters evaluated in discriminating pepper spray potency and correlated well with the relative and total capsaicinoid concentration in the products. Products containing greater than 16 mg ml(-1) capsaicinoid concentration produced greater erythema responses in Caucasians than Asians. Asians responded greater to the synthetic analog, nonivamide, than to mixtures of capsaicinoids, while Caucasians responded equally to both capsaicinoid analogs. Thus, pepper spray product potency in human skin reflects the total capsaicinoid concentration, the specific capsaicin analog(s) present, and the race of the individual exposed. The finding that the reflectance colorimeter a* scale can differentiate these parameters in skin will have a significant impact on evaluating the use and efficacy of pepper spray products in humans. 2005 John Wiley & Sons, Ltd.

Ethanol production from carob extract by using Saccharomyces cerevisiae.

PubMed

Turhan, Irfan; Bialka, Katherine L; Demirci, Ali; Karhan, Mustafa

2010-07-01

Carob has been widely grown in the Mediterranean region for a long time. It has been regarded as only a forest tree and has been neglected for other economical benefits. However, in recent years, this fruit has gained attention for several applications. As petroleum has become depleted, renewable energy production has started to gain attention all over the world; including the production of ethanol from underutilized agricultural products such as carob. In this project, the optimum extraction conditions were determined for the carob fruit by using the response surface design method. The obtained extract was utilized for production of ethanol by using suspended Saccharomyces cerevisiae fermentation. The effect of various fermentation parameters such as pH, media content and inoculum size were evaluated for ethanol fermentation in carob extract. Also, in order to determine economically appropriate nitrogen sources, four different nitrogen sources were evaluated. The optimum extraction condition for carob extract was determined to be 80 degrees C, 2h in 1:4 dilution rate (fruit: water ratio) according to the result of response surface analysis (115.3g/L). When the fermentation with pH at 5.5 was applied, the final ethanol concentration and production rates were 42.6g/L and 3.37 g/L/h, respectively, which were higher than using an uncontrolled pH. Among inoculum sizes of 1%, 3%, and 5%, 3% was determined as the best inoculum size. The maximum production rate and final ethanol concentration were 3.48 g/L/h and 44.51%, respectively, with an alternative nitrogen source of meat-bone meal. Overall, this study suggested that carob extract can be utilized for production of ethanol in order to meet the demands of renewable energy. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Corn response and soil nutrient concentration from subsurface application of poultry litter

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer management is vital to corn (Zea mays L.) production from financial and environmental perspectives. Poultry litter as a nutrient source in this cropping system is generally surface broadcast, potentially causing volatilization of NH3. Recently a new application method was devel...

Plasmodium falciparum erythrocyte membrane protein-1 specifically suppresses early production of host interferon-gamma.

PubMed

D'Ombrain, Marthe C; Voss, Till S; Maier, Alexander G; Pearce, J Andrew; Hansen, Diana S; Cowman, Alan F; Schofield, Louis

2007-08-16

Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) is a variable antigen expressed by P. falciparum, the malarial parasite. PfEMP-1, present on the surface of infected host erythrocytes, mediates erythrocyte binding to vascular endothelium, enabling the parasite to avoid splenic clearance. In addition, PfEMP-1 is proposed to regulate host immune responses via interactions with the CD36 receptor on antigen-presenting cells. We investigated the immunoregulatory function of PfEMP-1 by comparing host cell responses to erythrocytes infected with either wild-type parasites or transgenic parasites lacking PfEMP-1. We showed that PfEMP-1 suppresses the production of the cytokine interferon-gamma by human peripheral blood mononuclear cells early after exposure to P. falciparum. Suppression of this rapid proinflammatory response was CD36 independent and specific to interferon-gamma production by gammadelta-T, NK, and alphabeta-T cells. These data demonstrate a parasite strategy for downregulating the proinflammatory interferon-gamma response and further establish transgenic parasites lacking PfEMP-1 as powerful tools for elucidating PfEMP-1 functions.

Global Precipitation Measurement (GPM) Mission: Precipitation Processing System (PPS) GPM Mission Gridded Text Products Provide Surface Precipitation Retrievals

NASA Technical Reports Server (NTRS)

Stocker, Erich Franz; Kelley, O.; Kummerow, C.; Huffman, G.; Olson, W.; Kwiatkowski, J.

2015-01-01

In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar, and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMIDPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for researchers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations.This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments GMI, DPR, and combined GMIDPR (2) surface precipitation retrievals for the partner constellation satellites. Both of these gridded products are generated for a.25 degree x.25 degree hourly grid, which are packaged into daily ASCII (American Standard Code for Information Interchange) files that can downloaded from the PPS FTP (File Transfer Protocol) site. To reduce the download size, the files are compressed using the gzip utility.This paper will focus on presenting high-level details about the gridded text product being generated from the instruments on the GPM core satellite. But summary information will also be presented about the partner radiometer gridded product. All retrievals for the partner radiometer are done using the GPROF2014 algorithmusing as input the PPS generated inter-calibrated 1C product for the radiometer.

GPM Mission Gridded Text Products Providing Surface Precipitation Retrievals

NASA Astrophysics Data System (ADS)

Stocker, Erich Franz; Kelley, Owen; Huffman, George; Kummerow, Christian

2015-04-01

In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar), and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMI/DPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for reseachers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations. This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments - GMI, DPR, and combined GMI/DPR (2) surface precipitation retrievals for the partner constellation satellites. Both of these gridded products are generated for a .25 degree x .25 degree hourly grid, which are packaged into daily ASCII files that can downloaded from the PPS FTP site. To reduce the download size, the files are compressed using the gzip utility. This paper will focus on presenting high-level details about the gridded text product being generated from the instruments on the GPM core satellite. But summary information will also be presented about the partner radiometer gridded product. All retrievals for the partner radiometer are done using the GPROF2014 algorithm using as input the PPS generated inter-calibrated 1C product for the radiometer.

Candida innate immunity at the mucosa.

PubMed

Richardson, Jonathan P; Moyes, David L; Ho, Jemima; Naglik, Julian R

2018-03-09

The tremendous diversity in microbial species that colonise the mucosal surfaces of the human body is only now beginning to be fully appreciated. Distinguishing between the behaviour of commensal microbes and harmful pathogens that reside at mucosal sites in the body is a complex, and exquisitely fine-tuned process central to mucosal health. The fungal pathobiont Candida albicans is frequently isolated from mucosal surfaces with an asymptomatic carriage rate of approximately 60% in the human population. While normally a benign member of the microbiota, overgrowth of C. albicans often results in localised mucosal infection causing morbidity in otherwise healthy individuals, and invasive infection that often causes death in the absence of effective immune defence. C. albicans triggers numerous innate immune responses at mucosal surfaces, and detection of C. albicans hyphae in particular, stimulates the production of antimicrobial peptides, danger-associated molecular patterns and cytokines that function to reduce fungal burdens during infection. This review will summarise our current understanding of innate immune responses to C. albicans at mucosal surfaces. Copyright © 2018. Published by Elsevier Ltd.

Stability of peatland carbon to rising temperatures

DOE PAGES

Wilson, R. M.; Hopple, A. M.; Tfaily, M. M.; ...

2016-12-13

Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. Here, we show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH 4 emissions. But, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20–30 cm of peat from experimental plots have higher CH 4 production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH 4 and COmore » 2 are produced primarily from decomposition of surface-derived modern photosynthate, not catotelm C. Furthermore, there are no differences in microbial abundances, dissolved organic matter concentrations or degradative enzyme activities among treatments. Our results suggest that although surface peat will respond to increasing temperature, the large reservoir of catotelm C is stable under current anoxic conditions.« less

Stability of peatland carbon to rising temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, R. M.; Hopple, A. M.; Tfaily, M. M.

Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. Here, we show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH 4 emissions. But, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20–30 cm of peat from experimental plots have higher CH 4 production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH 4 and COmore » 2 are produced primarily from decomposition of surface-derived modern photosynthate, not catotelm C. Furthermore, there are no differences in microbial abundances, dissolved organic matter concentrations or degradative enzyme activities among treatments. Our results suggest that although surface peat will respond to increasing temperature, the large reservoir of catotelm C is stable under current anoxic conditions.« less

Stress-induced alterations in interferon production and class II histocompatibility antigen expression

NASA Technical Reports Server (NTRS)

Sonnenfeld, G.; Cunnick, J. E.; Armfield, A. V.; Wood, P. G.; Rabin, B. S.

1992-01-01

Mild electric foot-shock has been shown to be a stressor that can alter immune responses. Male Lewis rats were exposed to one session of 16 5.0-s 1.6-mA foot-shocks. Production of interferon-gamma by splenocytes in response to concanavalin-A was decreased in spleens from the shocked rats compared to control spleens. Spleen cells from rats treated with nadolol, a peripherally acting beta-adrenergic receptor antagonist, and then shocked, showed dose-dependent attenuation of the suppression of interferon-gamma production. This suggests that catecholamines mediate shock-induced suppression of interferon-gamma production. The percentage of splenic mononuclear cells expressing class II histocompatibility (Ia) antigens on their surfaces from spleens of shocked rats was determined by flow cytometry. Significantly decreased class II positive mononuclear cells were present in the spleens of shocked rats in comparison to the spleens of control rats. This may reflect an alteration of cell trafficking or decreased production of class II antigens.

High-efficient photo-electron transport channel in SiC constructed by depositing cocatalysts selectively on specific surface sites for visible-light H{sub 2} production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Da; Peng, Yuan; Wang, Qi

2016-04-18

Control cocatalyst location on a metal-free semiconductor to promote surface charge transfer for decreasing the electron-hole recombination is crucial for enhancing solar energy conversion. Based on the findings that some metals have an affinity for bonding with the specific atoms of polar semiconductors at a heterostructure interface, we herein control Pt deposition selectively on the Si sites of a micro-SiC photocatalyst surface via in-situ photo-depositing. The Pt-Si bond forming on the interface constructs an excellent channel, which is responsible for accelerating photo-electron transfer from SiC to Pt and then reducing water under visible-light. The hydrogen production is enhanced by twomore » orders of magnitude higher than that of bare SiC, and 2.5 times higher than that of random-depositing nano-Pt with the same loading amount.« less

Polycaprolactone nanowire surfaces as interfaces for cardiovascular applications

NASA Astrophysics Data System (ADS)

Leszczak, Victoria

Cardiovascular disease is the leading killer of people worldwide. Current treatments include organ transplants, surgery, metabolic products and mechanical/synthetic implants. Of these, mechanical and synthetic implants are the most promising. However, rejection of cardiovascular implants continues to be a problem, eliciting a need for understanding the mechanisms behind tissue-material interaction. Recently, bioartificial implants, consisting of synthetic tissue engineering scaffolds and cells, have shown great promise for cardiovascular repair. An ideal cardiovascular implant surface must be capable of adhering cells and providing appropriate physiological responses while the native tissue integrates with the scaffold. However, the success of these implants is not only dependent on tissue integration but also hemocompatibility (interaction of material with blood components), a property that depends on the surface of the material. A thorough understanding of the interaction of cardiovascular cells and whole blood and its components with the material surface is essential in order to have a successful application which promotes healing as well as native tissue integration and regeneration. The purpose of this research is to study polymeric nanowire surfaces as potential interfaces for cardiovascular applications by investigating cellular response as well as hemocompatibility.

Biological responses to M13 bacteriophage modified titanium surfaces in vitro.

PubMed

Sun, Yuhua; Li, Yiting; Wu, Baohua; Wang, Jianxin; Lu, Xiong; Qu, Shuxin; Weng, Jie; Feng, Bo

2017-08-01

Phage-based materials have showed great potential in tissue engineering application. However, it is unknown what inflammation response will happen to this kind of materials. This work is to explore the biological responses to M13 bacteriophage (phage) modified titanium surfaces in vitro from the aspects of their interaction with macrophages, osteoblasts and mineralization behavior. Pretreated Ti surface, Ti surfaces with noncrosslinked phage film (APP) and crosslinked phage film (APPG) were compared. Phage films could limit the macrophage adhesion and activity due to inducing adherent-cell apoptosis. The initial inflammatory activity (24h) caused by phage films was relatively high with more production of TNF-α, but in the later stage (7-10days) inflammatory response was reduced with lower TNF-α, IL-6 and higher IL-10. In addition, phage films improved osteoblast adhesion, differentiation, and hydroapatite (HA)-forming via a combination of topographical and biochemcial cues. The noncrosslinked phage film displayed the best immunomodulatory property, osteogenic activity and HA mineralization ability. This work provides better understanding of inflammatory and osteogenetic activity of phage-based materials and contributes to their future application in tissue engineering. In vivo, the bone and immune cells share a common microenvironment, and are being affected by similar cytokines, signaling molecules, transcription factors and membrane receptors. Ideal implants should cause positive biological response, including adequate and appropriate inflammatory reaction, well-balanced bone formation and absorption. Phage-based materials have showed great potential in tissue engineering application. However, at present it is unknown what inflammation response will happen to this kind of materials. A good understanding of the immune response possibly induced by phage-based materials is needed. This work studied the osteoimmunomodulation property of phage films on titanium surface, involving inflammatory response, osteogenic activity and biomineralization ability. It provides more understanding of the phage-based materials and contributes to their future application in tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Low Latency DESDynI Data Products for Disaster Response, Resource Management and Other Applications

NASA Technical Reports Server (NTRS)

Doubleday, Joshua R.; Chien, Steve A.; Lou, Yunling

2011-01-01

We are developing onboard processor technology targeted at the L-band SAR instrument onboard the planned DESDynI mission to enable formation of SAR images onboard opening possibilities for near-real-time data products to augment full data streams. Several image processing and/or interpretation techniques are being explored as possible direct-broadcast products for use by agencies in need of low-latency data, responsible for disaster mitigation and assessment, resource management, agricultural development, shipping, etc. Data collected through UAVSAR (L-band) serves as surrogate to the future DESDynI instrument. We have explored surface water extent as a tool for flooding response, and disturbance images on polarimetric backscatter of repeat pass imagery potentially useful for structural collapse (earthquake), mud/land/debris-slides etc. We have also explored building vegetation and snow/ice classifiers, via support vector machines utilizing quad-pol backscatter, cross-pol phase, and a number of derivatives (radar vegetation index, dielectric estimates, etc.). We share our qualitative and quantitative results thus far.

Response surface methodology assisted biodiesel production from waste cooking oil using encapsulated mixed enzyme.

PubMed

Razack, Sirajunnisa Abdul; Duraiarasan, Surendhiran

2016-01-01

In the recent scenario, consumption of petroleum fuels has increased to greater height which has led to deforestation and decline in fossil fuels. In order to tackle the perilous situation, alternative fuel has to be generated. Biofuels play a vital role in substituting the diesel fuels as they are renewable and ecofriendly. Biodiesel, often referred to as green fuel, could be a potential replacement as it could be synthesized from varied substrates, advantageous being the microalgae in several ways. The present investigation was dealt with the interesterification of waste cooking oil using immobilised lipase from mixed cultures for biodiesel production. In order to standardize the production for a scale up process, the parameters necessary for interesterification had been optimized using the statistical tool, Central Composite Design - Response Surface Methodology. The optimal conditions required to generate biodiesel were 2 g enzyme load, 1:12 oil to methyl acetate ratio, 60 h reaction time and 35 °C temperature, yielding a maximum of 93.61% biodiesel. The immobilised lipase beads remain stable without any changes in their function and structure even after 20 cycles which made this study, less cost intensive. In conclusion, the study revealed that the cooking oil, a residue of many dining centers, left as waste product, can be used as a potential raw material for the production of ecofriendly and cost effective biofuel, the biodiesel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and Surface-Specific Analysis of Molecular Constituents Relevant to Biogenic Secondary Organic Aerosol Material

NASA Astrophysics Data System (ADS)

Be, A. G.; Upshur, M. A.; Chase, H. M.; Geiger, F.; Thomson, R. J.

2017-12-01

Secondary organic aerosol (SOA) particles formed from the oxidation of biogenic volatile organic compounds (BVOCs) remain a principal, yet elusive, class of airborne particulate matter that impacts the Earth's radiation budget. Given the characteristic molecular complexity comprising biogenic SOA particles, chemical information selective to the gas-aerosol interface may be valuable in the investigation of such systems, as surface considerations likely dictate the phenomena driving particle evolution mechanisms and climate effects. In particular, cloud activation processes may be parameterized using the surface tension depression that coincides with partitioning of surface-active organic species to the gas-droplet interface. However, the extent to which surface chemical processes, such as cloud droplet condensation, are influenced by the chemical structure and reactivity of individual surface-active molecules in SOA particles is largely unknown. We seek to study terpene-derived organic species relevant to the surfaces of biogenic SOA particles via synthesis of putative oxidation products followed by analysis using surface-selective physicochemical measurements. Using dynamic surface tension measurements, considerable differences are observed in the surface tension depression of aqueous pendant droplets that contain synthetically prepared ozonolysis products derived from abundant terpene precursors. Furthermore, sum frequency generation spectroscopy is utilized for comparison of the surface vibrational spectral responses of synthesized reference compounds with those observed for laboratory aerosol toward probing the surface composition of SOA material. Such ongoing findings highlight the underlying importance of molecular structure and reactivity when considering the surface chemistry of biogenic terpene-derived atmospheric aerosols.

Climate change impacts on net primary production (NPP) and export production (EP) regulated by increasing stratification and phytoplankton community structure in the CMIP5 models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Weiwei; Randerson, James T.; Moore, J. Keith

We examine climate change impacts on net primary production (NPP) and export production (sinking particulate flux; EP) with simulations from nine Earth system models (ESMs) performed in the framework of the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Global NPP and EP are reduced by the end of the century for the intense warming scenario of Representative Concentration Pathway (RCP) 8.5. Relative to the 1990s, NPP in the 2090s is reduced by 2–16% and EP by 7–18%. The models with the largest increases in stratification (and largest relative declines in NPP and EP) also show the largest positivemore » biases in stratification for the contemporary period, suggesting overestimation of climate change impacts on NPP and EP. All of the CMIP5 models show an increase in stratification in response to surface–ocean warming and freshening, which is accompanied by decreases in surface nutrients, NPP and EP. There is considerable variability across the models in the magnitudes of NPP, EP, surface nutrient concentrations and their perturbations by climate change. The negative response of NPP and EP to increasing stratification reflects primarily a bottom-up control, as upward nutrient flux declines at the global scale. Models with dynamic phytoplankton community structure show larger declines in EP than in NPP. This pattern is driven by phytoplankton community composition shifts, with reductions in productivity by large phytoplankton as smaller phytoplankton (which export less efficiently) are favored under the increasing nutrient stress. Thus, the projections of the NPP response to climate change are critically dependent on the simulated phytoplankton community structure, the efficiency of the biological pump and the resulting levels of regenerated production, which vary widely across the models. In conclusion, community structure is represented simply in the CMIP5 models, and should be expanded to better capture the spatial patterns and climate-driven changes in export efficiency.« less

Climate change impacts on net primary production (NPP) and export production (EP) regulated by increasing stratification and phytoplankton community structure in the CMIP5 models

DOE PAGES

Fu, Weiwei; Randerson, James T.; Moore, J. Keith

2016-09-16

We examine climate change impacts on net primary production (NPP) and export production (sinking particulate flux; EP) with simulations from nine Earth system models (ESMs) performed in the framework of the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Global NPP and EP are reduced by the end of the century for the intense warming scenario of Representative Concentration Pathway (RCP) 8.5. Relative to the 1990s, NPP in the 2090s is reduced by 2–16% and EP by 7–18%. The models with the largest increases in stratification (and largest relative declines in NPP and EP) also show the largest positivemore » biases in stratification for the contemporary period, suggesting overestimation of climate change impacts on NPP and EP. All of the CMIP5 models show an increase in stratification in response to surface–ocean warming and freshening, which is accompanied by decreases in surface nutrients, NPP and EP. There is considerable variability across the models in the magnitudes of NPP, EP, surface nutrient concentrations and their perturbations by climate change. The negative response of NPP and EP to increasing stratification reflects primarily a bottom-up control, as upward nutrient flux declines at the global scale. Models with dynamic phytoplankton community structure show larger declines in EP than in NPP. This pattern is driven by phytoplankton community composition shifts, with reductions in productivity by large phytoplankton as smaller phytoplankton (which export less efficiently) are favored under the increasing nutrient stress. Thus, the projections of the NPP response to climate change are critically dependent on the simulated phytoplankton community structure, the efficiency of the biological pump and the resulting levels of regenerated production, which vary widely across the models. In conclusion, community structure is represented simply in the CMIP5 models, and should be expanded to better capture the spatial patterns and climate-driven changes in export efficiency.« less

FORAGES AND PASTURES SYMPOSIUM: Improving soil health and productivity on grasslands using managed grazing of livestock.

PubMed

Russell, J R; Bisinger, J J

2015-06-01

Beyond grazing, managed grasslands provide ecological services that may offer economic incentives for multifunctional use. Increasing biodiversity of plant communities may maximize net primary production by optimizing utilization of available light, water, and nutrient resources; enhance production stability in response to climatic stress; reduce invasion of exotic species; increase soil OM; reduce nutrient leaching or loading in surface runoff; and provide wildlife habitat. Strategically managed grazing may increase biodiversity of cool-season pastures by creating disturbance in plant communities through herbivory, treading, nutrient cycling, and plant seed dispersal. Soil OM will increase carbon and nutrient sequestration and water-holding capacity of soils and is greater in grazed pastures than nongrazed grasslands or land used for row crop or hay production. However, results of studies evaluating the effects of different grazing management systems on soil OM are limited and inconsistent. Although roots and organic residues of pasture forages create soil macropores that reduce soil compaction, grazing has increased soil bulk density or penetration resistance regardless of stocking rates or systems. But the effects of the duration of grazing and rest periods on soil compaction need further evaluation. Because vegetative cover dissipates the energy of falling raindrops and plant stems and tillers reduce the rate of surface water flow, managing grazing to maintain adequate vegetative cover will minimize the effects of treading on water infiltration in both upland and riparian locations. Through increased diversity of the plant community with alterations of habitat structure, grazing systems can be developed that enhance habitat for wildlife and insect pollinators. Although grazing management may enhance the ecological services provided by grasslands, environmental responses are controlled by variations in climate, soil, landscape position, and plant community resulting in considerable spatial and temporal variation in the responses. Furthermore, a single grazing management system may not maximize livestock productivity and each of the potential ecological services provided by grasslands. Therefore, production and ecological goals must be integrated to identify the optimal grazing management system.

Response of Sphagnum fuscum to Nitrogen Deposition: A Case Study of Ombrogenous Peatlands in Alberta, Canada

USGS Publications Warehouse

Vitt, D.H.; Wieder, K.; Halsey, L.A.; Turetsky, M.

2003-01-01

Peatlands cover about 30% of northeastern Alberta and are ecosystems that are sensitive to nitrogen deposition. In polluted areas of the UK, high atmospheric N deposition (as a component of acid deposition) has been considered among the causes of Sphagnum decline in bogs (ombrogenous peatlands). In relatively unpolluted areas of western Canada and northern Sweden, short-term experimental studies have shown that Sphagnum responds quickly to nutrient loading, with uptake and retention of nitrogen and increased production. Here we examine the response of Sphagnum fuscum to enhanced nitrogen deposition generated during 34 years of oil sands mining through the determination of net primary production (NPP) and nitrogen concentrations in the upper peat column. We chose six continental bogs receiving differing atmospheric nitrogen loads (modeled using a CALPUFF 2D dispersion model). Sphagnum fuscum net primary production (NPP) at the high deposition site (Steepbank - mean of 600 g/m2; median of 486 g/m2) was over three times as high than at five other sites with lower N deposition. Additionally, production of S. fuscum may be influenced to some extent by distance of the moss surface from the water table. Across all sites, peat nitrogen concentrations are highest at the surface, decreasing in the top 3 cm with no significant change with increasing depth. We conclude that elevated N deposition at the Steepbank site has enhanced Sphagnum production. Increased N concentrations are evident only in the top 1-cm of the peat profile. Thus, 34 years after mine startup, increased N-deposition has increased net primary production of Sphagnum fuscum without causing elevated levels of nitrogen in the organic matter profile. A response to N-stress for Sphagnum fuscum is proposed at 14-34 kg ha-1 yr-1. A review of N-deposition values reveals a critical N-deposition value of between 14.8 and 15.7 kg ha -1 yr-1 for NPP of Sphagnum species.

Surface modification of ferritic steels using MEVVA and duoplasmatron ion sources

NASA Astrophysics Data System (ADS)

Kulevoy, Timur V.; Chalyhk, Boris B.; Fedin, Petr A.; Sitnikov, Alexey L.; Kozlov, Alexander V.; Kuibeda, Rostislav P.; Andrianov, Stanislav L.; Orlov, Nikolay N.; Kravchuk, Konstantin S.; Rogozhkin, Sergey V.; Useinov, Alexey S.; Oks, Efim M.; Bogachev, Alexey A.; Nikitin, Alexander A.; Iskandarov, Nasib A.; Golubev, Alexander A.

2016-02-01

Metal Vapor Vacuum Arc (MEVVA) ion source (IS) is a unique tool for production of high intensity metal ion beam that can be used for material surface modification. From the other hand, the duoplasmatron ion source provides the high intensity gas ion beams. The MEVVA and duoplasmatron IS developed in Institute for Theoretical and Experimental Physics were used for the reactor steel surface modification experiments. Response of ferritic-martensitic steel specimens on titanium and nitrogen ions implantation and consequent vacuum annealing was investigated. Increase in microhardness of near surface region of irradiated specimens was observed. Local chemical analysis shows atom mixing and redistribution in the implanted layer followed with formation of ultrafine precipitates after annealing.

Structure and Composition of the Distant Lunar Exosphere: Constraints from ARTEMIS Observations of Ion Acceleration in Time-Varying Fields

NASA Technical Reports Server (NTRS)

Halekas, J. S.; Poppe, A. R.; Farrell, W. M.; McFadden, J. P.

2016-01-01

By analyzing the trajectories of ionized constituents of the lunar exosphere in time-varying electromagnetic fields, we can place constraints on the composition, structure, and dynamics of the lunar exosphere. Heavy ions travel slower than light ions in the same fields, so by observing the lag between field rotations and the response of ions from the lunar exosphere, we can place constraints on the composition of the ions. Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) provides an ideal platform to utilize such an analysis, since its two-probe vantage allows precise timing of the propagation of field discontinuities in the solar wind, and its sensitive plasma instruments can detect the ion response. We demonstrate the utility of this technique by using fully time-dependent charged particle tracing to analyze several minutes of ion observations taken by the two ARTEMIS probes 3000-5000 km above the dusk terminator on 25 January 2014. The observations from this time period allow us to reach several interesting conclusions. The ion production at altitudes of a few hundred kilometers above the sunlit surface of the Moon has an unexpectedly significant contribution from species with masses of 40 amu or greater. The inferred distribution of the neutral source population has a large scale height, suggesting that micrometeorite impact vaporization and/or sputtering play an important role in the production of neutrals from the surface. Our observations also suggest an asymmetry in ion production, consistent with either a compositional variation in neutral vapor production or a local reduction in solar wind sputtering in magnetic regions of the surface.

Size- and structure-dependent toxicity of silica particulates

NASA Astrophysics Data System (ADS)

Hanada, Sanshiro; Miyaoi, Kenichi; Hoshino, Akiyoshi; Inasawa, Susumu; Yamaguchi, Yukio; Yamamoto, Kenji

2011-03-01

Nano- and micro-particulates firmly attach with the surface of various biological systems. In some chronic pulmonary disease such as asbestosis and silicosis, causative particulates will induce chronic inflammatory disorder, followed by poor prognosis diseases. However, nano- and micro-scale specific toxicity of silica particulates is not well examined enough to recognize the risk of nano- and micro-particulates from the clinical aspect. To clarify the effect of the size and structure of silica particulates on the cellular damage and the biological response, we assessed the cytotoxicity of the various kinds of silica particles including amorphous and crystalline silica, in mouse alveolar macrophage culture, focusing on the fibrotic and inflammatory response. Our study showed that the cytotoxicity, which depends on the particle size and surface area, is correlated with their inflammatory response. By contrast, production of TGF-β, which is one of the fibrotic agents in lung, by addition of crystal silica was much higher than that of amorphous silica. We conclude that fibrosis and inflammation are induced at different phases and that the size- and structure-differences of silica particulates affect the both biological responses, caused by surface activity, radical species, and so on.

Application of Response Surface Methodology for Optimization of Extracellular Glucoamylase Production by Candida guilliermondii.

PubMed

Mohamed, Lagzouli; Kettani, Youssfi El; Ali, Aitounejjar; Mohamed, Elyachioui; Mohamed, Jadal

2017-01-01

Glucoamylase is among the most important enzymes in biotechnology. The present study aims to determine better conditions for growth and glucoamylase production by Candida guilliermondii and to reduce the overall cost of the medium using Box-Behnken design with one central point and response surface methodology. Box-Behnken factorial design based on three levels was carried out to obtain optimal medium combination of five independent variables such as initial pH, soluble starch, CH4N2O, yeast extract and MgSO4. Forty one randomized mediums were incubated in flask on a rotary shaker at 105 rpm for 72 h at 30°C. The production of biomass was found to be pH and starch dependent, maximum production when the starch concentration was 8 g L-1 and the initial pH was 6, while maximum glucoamylase production was found at 6.5 of initial pH, 4 g L-1 yeast extract and 6 g L-1 starch, whereas yeast extract and urea were highly significant, but interacted negatively. Box-Behnken factorial design used for the analysis of treatment combinations gave a second-order polynomial regression model with R2 = 0.976 for Biomass and R2 = 0.981 for glucoamylase. The final biomass and glucoamylase activity obtained was very close to the calculated parameters according to the p-values (p<0.001), the predicted optimal parameters were confirmed and provides a basis for further studies in baking additives and in the valuation of starch waste products.

Use of response surface methodology to evaluate the effect of metal ions (Ca2+, Ni2+, Mn2+, Cu2+) on production of antifungal compounds by Paenibacillus polymyxa.

PubMed

Raza, Waseem; Hongsheng, Wu; Qirong, Shen

2010-03-01

The effects of four metal ions (Ca(2+), Ni(2+), Mn(2+) and Cu(2+)) were evaluated on growth and production of antifungal compounds by Paenibacillus polymyxa SQR-21 and a quadratic predictive model was developed using response surface methodology (RSM). The results revealed, Mn(2+) and Ni(2+) showed most positive synergistic interactive affect on production of antifungal compounds followed by the positive interactive synergistic affect of Cu(2+) and Ni(2+) and then Mn(2+) and Cu(2+). While the interactive effect of Ca(2+) with all other three metals inhibited the production of antifungal compounds. The Mn(2+) (P=0.0384), Ni(2+) (P=0.0004) and Cu(2+) (P=0.0117) significantly affected the production of antifungal compounds while the effect of Ca(2+) (P=0.1851) was less significant. The maximum growth (OD(600)=1.55) was obtained at 500 (0), 125 (0), 100 (-2) and 37.5 (0) microM levels and the maximum size of inhibition zone (31 mm) was measured at 400 (-1), 150 (1), 400 (1) and 25 microM (-1) levels of Ca(2+), Mn(2+), Ni(2+) and Cu(2+), respectively. The RSM model provided an easy and effective way to determine the interactive effect of metal ions on production of antifungal compounds by P. polymyxa SQR-21 so that optimum media recipes can be developed to produce maximum amounts of antifungal compounds under laboratory and commercial fermentation conditions. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Sequential lignin depolymerization by combination of biocatalytic and formic acid/formate treatment steps.

PubMed

Gasser, Christoph A; Čvančarová, Monika; Ammann, Erik M; Schäffer, Andreas; Shahgaldian, Patrick; Corvini, Philippe F-X

2017-03-01

Lignin, a complex three-dimensional amorphous polymer, is considered to be a potential natural renewable resource for the production of low-molecular-weight aromatic compounds. In the present study, a novel sequential lignin treatment method consisting of a biocatalytic oxidation step followed by a formic acid-induced lignin depolymerization step was developed and optimized using response surface methodology. The biocatalytic step employed a laccase mediator system using the redox mediator 1-hydroxybenzotriazole. Laccases were immobilized on superparamagnetic nanoparticles using a sorption-assisted surface conjugation method allowing easy separation and reuse of the biocatalysts after treatment. Under optimized conditions, as much as 45 wt% of lignin could be solubilized either in aqueous solution after the first treatment or in ethyl acetate after the second (chemical) treatment. The solubilized products were found to be mainly low-molecular-weight aromatic monomers and oligomers. The process might be used for the production of low-molecular-weight soluble aromatic products that can be purified and/or upgraded applying further downstream processes.

Optical surface analysis: a new technique for the inspection and metrology of optoelectronic films and wafers

NASA Astrophysics Data System (ADS)

Bechtler, Laurie; Velidandla, Vamsi

2003-04-01

In response to demand for higher volumes and greater product capability, integrated optoelectronic device processing is rapidly increasing in complexity, benefiting from techniques developed for conventional silicon integrated circuit processing. The needs for high product yield and low manufacturing cost are also similar to the silicon wafer processing industry. This paper discusses the design and use of an automated inspection instrument called the Optical Surface Analyzer (OSA) to evaluate two critical production issues in optoelectronic device manufacturing: (1) film thickness uniformity, and (2) defectivity at various process steps. The OSA measurement instrument is better suited to photonics process development than most equipment developed for conventional silicon wafer processing in two important ways: it can handle both transparent and opaque substrates (unlike most inspection and metrology tools), and it is a full-wafer inspection method that captures defects and film variations over the entire substrate surface (unlike most film thickness measurement tools). Measurement examples will be provided in the paper for a variety of films and substrates used for optoelectronics manufacturing.

Complex chemical composition of colored surface films formed from reactions of propanal in sulfuric acid at upper troposphere/lower stratosphere aerosol acidities.

PubMed

Van Wyngarden, A L; Pérez-Montaño, S; Bui, J V H; Li, E S W; Nelson, T E; Ha, K T; Leong, L; Iraci, L T

Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40-80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas phase organic species into tropospheric aerosols and are potentially more important at the high acidities characteristic of UT/LS particles. In this study, experiments combining sulfuric acid (H 2 SO 4 ) with propanal and with mixtures of propanal with glyoxal and/or methylglyoxal at acidities typical of UT/LS aerosols produced highly colored surface films (and solutions) that may have implications for aerosol properties. In order to identify the chemical processes responsible for the formation of the surface films, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and 1 H nuclear magnetic resonance (NMR) spectroscopies were used to analyze the chemical composition of the films. Films formed from propanal were a complex mixture of aldol condensation products, acetals and propanal itself. The major aldol condensation products were the dimer (2-methyl-2-pentenal) and 1,3,5-trimethylbenzene that was formed by cyclization of the linear aldol condensation trimer. Additionally, the strong visible absorption of the films indicates that higher-order aldol condensation products must also be present as minor species. The major acetal species were 2,4,6-triethyl-1,3,5-trioxane and longer-chain linear polyacetals which are likely to separate from the aqueous phase. Films formed on mixtures of propanal with glyoxal and/or methylglyoxal also showed evidence of products of cross-reactions. Since cross-reactions would be more likely than self-reactions under atmospheric conditions, similar reactions of aldehydes like propanal with common aerosol organic species like glyoxal and methylglyoxal have the potential to produce significant organic aerosol mass and therefore could potentially impact chemical, optical and/or cloud-forming properties of aerosols, especially if the products partition to the aerosol surface.

Complex chemical composition of colored surface films formed from reactions of propanal in sulfuric acid at upper troposphere/lower stratosphere aerosol acidities

PubMed Central

Van Wyngarden, A. L.; Pérez-Montaño, S.; Bui, J. V. H.; Li, E. S. W.; Nelson, T. E.; Ha, K. T.; Leong, L.; Iraci, L. T.

2016-01-01

Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40–80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas phase organic species into tropospheric aerosols and are potentially more important at the high acidities characteristic of UT/LS particles. In this study, experiments combining sulfuric acid (H2SO4) with propanal and with mixtures of propanal with glyoxal and/or methylglyoxal at acidities typical of UT/LS aerosols produced highly colored surface films (and solutions) that may have implications for aerosol properties. In order to identify the chemical processes responsible for the formation of the surface films, attenuated total reflectance–Fourier transform infrared (ATR-FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopies were used to analyze the chemical composition of the films. Films formed from propanal were a complex mixture of aldol condensation products, acetals and propanal itself. The major aldol condensation products were the dimer (2-methyl-2-pentenal) and 1,3,5-trimethylbenzene that was formed by cyclization of the linear aldol condensation trimer. Additionally, the strong visible absorption of the films indicates that higher-order aldol condensation products must also be present as minor species. The major acetal species were 2,4,6-triethyl-1,3,5-trioxane and longer-chain linear polyacetals which are likely to separate from the aqueous phase. Films formed on mixtures of propanal with glyoxal and/or methylglyoxal also showed evidence of products of cross-reactions. Since cross-reactions would be more likely than self-reactions under atmospheric conditions, similar reactions of aldehydes like propanal with common aerosol organic species like glyoxal and methylglyoxal have the potential to produce significant organic aerosol mass and therefore could potentially impact chemical, optical and/or cloud-forming properties of aerosols, especially if the products partition to the aerosol surface. PMID:27212937

Idea Project Final Report, A Sequential Hypothesis Testing-Based Decision-Making System For Freeway Incident Response

DOT National Transportation Integrated Search

1995-10-01

THIS INVESTIGATION WAS COMPLETED AS PART OF THE ITS-IDEA PROGRAM WHICH IS ONE OF THREE IDEA PROGRAMS MANAGED BY THE TRANSPORTATION RESEARCH BOARD (TRB) TO FOSTER INNOVATIONS IN SURFACE TRANSPORTATION. IT FOCUSES ON PRODUCTS AND RESULT FOR THE DEVELOP...

Nanotechnology, nanosurfaces and silicone gel breast implants: current aspects

PubMed Central

Mendonça Munhoz, Alexandre; Santanelli di Pompeo, Fabio; De Mezerville, Roberto

2017-01-01

Abstract Nanotechnology is defined as the design of products that interact with biological systems on the nanoscopic scale. Creating a controlled nanotexture and understanding the ways in which surface properties impact inflammatory response is of the utmost significance in designing implants that can provide satisfactory outcomes. PMID:29250575

Surfactant and irrigation effects on wettable soils: Runoff, erosion, and water retention responses

USDA-ARS?s Scientific Manuscript database

Surfactants are chemical compounds that change the contact angle of water on solid surfaces and are commonly used to increase infiltration into hydrophobic soil. Since production fields with water-repellent soil often contain areas of wettable soil, surfactants applied to such fields will likely be ...

No-till corn response and soil nutrient concentrations from subsurface banding of poultry litter

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer management is vital to no-till corn (Zea mays) production from financial and environmental perspectives. Poultry litter as a nutrient source in this cropping system is generally land applied by surface broadcast, potentially causing volatilization of ammonia (NH3)-N. Recently a...

Improving the Analysis of Anthocyanidins from Blueberries Using Response Surface Methodology

USDA-ARS?s Scientific Manuscript database

Background: Recent interest in the health promoting potential of anthocyanins points to the need for robust and reliable analytical methods. It is essential to know that the health promoting chemicals are present in juices and other products processed from whole fruit. Many different methods have be...

Optimization of microwave-assisted extraction of protopine and allocryptopine from stems of Macleaya cordata (Willd) R. Br. using response surface methodology.

PubMed

Zhong, Ming; Huang, Ke-Long; Zeng, Jian-Guo; Li, Shuang; She, Jin-Ming; Li, Guiyin; Zhang, Li

2010-07-01

The purpose of the research was to investigate the multiple response optimizations for the extraction of protopine and allocryptopine from the stems of Macleaya cordata (Willd) R. Br. by using microwave-assisted extraction (MAE). A three-level, three-factor Box-Behnken design of response surface methodology was used to develop response model, and desirability function was employed to optimize the effects of main extraction parameters. Three variables, ethanol concentration (20-80%, v/v), extraction temperature (30-70 degrees C) and solvent/solid ratio (10:1 to 30:1, mL/g), were investigated in this study. The results showed that the optimum parameters of MAE were ethanol concentration of 45.2 % (v/v), extraction temperature of 54.7 degrees C and solvent/solid ratio of 20.4:1 (mL/g). Under these conditions, the extraction yields of protopine and allocryptopine were 89.4 and 102.0%, respectively, and the extracta sicca yield was 12.5%. The combination use of response surface methodology, Box-Behnken design and the appropriate desirability function could provide an insight into a lab-scale MAE process, and help to develop procedures for commercial production of active ingredients from medical plants.

Laser irradiation of Mg-Al-Zn alloy: Reduced electrochemical kinetics and enhanced performance in simulated body fluid.

PubMed

Florian, David C; Melia, Michael A; Steuer, Fritz W; Briglia, Bruce F; Purzycki, Michael K; Scully, John R; Fitz-Gerald, James M

2017-05-11

As a lightweight metal with mechanical properties similar to natural bone, Mg and its alloys are great prospects for biodegradable, load bearing implants. However, rapid degradation and H 2 gas production in physiological media has prevented widespread use of Mg alloys. Surface heterogeneities in the form of intermetallic particles dominate the corrosion response. This research shows that surface homogenization significantly improved the biological corrosion response observed during immersion in simulated body fluid (SBF). The laser processed Mg alloy exhibited a 50% reduction in mass loss and H 2 evolution after 24 h of immersion in SBF when compared to the wrought, cast alloy. The laser processed samples exhibited increased wettability as evident from wetting angle studies, further suggesting improved biocompatibility. Electrochemical analysis by potentiodynamic polarization measurements showed that the anodic and cathodic kinetics were reduced following laser processing and are attributed to the surface chemical homogeneity.

Developing the next generation of graphene-based platforms for cancer therapeutics: The potential role of reactive oxygen species.

PubMed

Tabish, Tanveer A; Zhang, Shaowei; Winyard, Paul G

2018-05-01

Graphene has a promising future in applications such as disease diagnosis, cancer therapy, drug/gene delivery, bio-imaging and antibacterial approaches owing to graphene's unique physical, chemical and mechanical properties alongside minimal toxicity to normal cells, and photo-stability. However, these unique features and bioavailability of graphene are fraught with uncertainties and concerns for environmental and occupational exposure. Changes in the physicochemical properties of graphene affect biological responses including reactive oxygen species (ROS) production. Lower production of ROS by currently available theranostic agents, e.g. magnetic nanoparticles, carbon nanotubes, gold nanostructures or polymeric nanoparticles, restricts their clinical application in cancer therapy. Oxidative stress induced by graphene accumulated in living organs is due to acellular factors which may affect physiological interactions between graphene and target tissues and cells. Acellular factors include particle size, shape, surface charge, surface containing functional groups, and light activation. Cellular responses such as mitochondrial respiration, graphene-cell interactions and pH of the medium are also determinants of ROS production. The mechanisms of ROS production by graphene and the role of ROS for cancer treatment, are poorly understood. The aim of this review is to set the theoretical basis for further research in developing graphene-based theranostic platforms. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

A Response Surface Methodology study on the role of factors affecting growth and volatile phenol production by Brettanomyces bruxellensis ISA 2211 in wine.

PubMed

Chandra, M; Barata, A; Ferreira-Dias, S; Malfeito-Ferreira, M; Loureiro, V

2014-09-01

The present study was aimed at determining the effect of glucose, ethanol and sulphur dioxide on the growth and volatile phenol production by Brettanomyces bruxellensis in red wines using a response surface methodology approach. Sulphur dioxide proved to have a significant (p < 0.05) negative linear and quadratic effect on growth and 4-ethylphenol production. Concentrations of sulphur dioxide higher than 20 mg L(-1), at pH 3.50, induced immediate loss of cell culturability under growth permissive levels of ethanol. Under high ethanol concentrations (14% v/v), the lag phase increased from 3 to 10 days, growth being fully arrested at 15% (v/v). Glucose up to 10 g L(-1) was found to be a significant factor (quadratic level) in biomass increase under low ethanol (<12.5% v/v) and low sulphite concentrations. However, when cells were inactivated by sulphur dioxide and ethanol, glucose (up to 10 g L(-1)) did not prevent cell death. Production of more than 50 μg L(-1) day(-1) of 4-ethylphenol was only observed in the presence of high numbers (10(6) CFU mL(-1)) of culturable cells, being stimulated by increasing glucose concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exo-polygalacturonase production by Bacillus subtilis CM5 in solid state fermentation using cassava bagasse

PubMed Central

Swain, Manas R.; Kar, Shaktimay; Ray, Ramesh C.

2009-01-01

The purpose of this investigation was to study the effect of Bacillus subtilis CM5 in solid state fermentation using cassava bagasse for production of exo-polygalacturonase (exo-PG). Response surface methodology was used to evaluate the effect of four main variables, i.e. incubation period, initial medium pH, moisture holding capacity (MHC) and incubation temperature on enzyme production. A full factorial Central Composite Design was applied to study these main factors that affected exo-PG production. The experimental results showed that the optimum incubation period, pH, MHC and temperature were 6 days, 7.0, 70% and 50°C, respectively for optimum exo-PG production. PMID:24031409

Rapid Response Products of The ARIA Project for the M6.0 August 24, 2014 South Napa Earthquake

NASA Astrophysics Data System (ADS)

Yun, S. H.; Owen, S. E.; Hua, H.; Milillo, P.; Fielding, E. J.; Hudnut, K. W.; Dawson, T. E.; Mccrink, T. P.; Jo, M. J.; Barnhart, W. D.; Manipon, G. J. M.; Agram, P. S.; Moore, A. W.; Jung, H. S.; Webb, F.; Milillo, G.; Rosinski, A.

2014-12-01

A magnitude 6.0 earthquake struck southern Napa county northeast of San Francisco, California, on Aug. 24, 2014, causing significant damage in the city of Napa and nearby areas. One day after the earthquake, the Advanced Rapid Imaging and Analysis (ARIA) team produced and released observations of coseismic ground displacement measured with continuous GPS stations of the Plate Boundary Observatory (operated by UNAVCO for the National Science Foundation) and the Bay Area Rapid Deformation network (operated by Berkeley Seismological Laboratory). Three days after the earthquake (Aug. 27), the Italian Space Agency's (ASI) COSMO-SkyMed (CSK) satellite acquired their first post-event data. On the same day, the ARIA team, in collaboration with ASI and University of Basilicata, produced and released a coseismic interferogram that revealed ground deformation and surface rupture. The depiction of the surface rupture - discontinuities of color fringes in the CSK interferogram - helped guide field geologists from the US Geological Survey and the California Geological Survey (CGS) to features that may have otherwise gone undetected. Small-scale cracks were found on a runway of the Napa County Airport, as well as bridge damage and damaged roads. ARIA's response to this event highlighted the importance of timeliness for mapping surface deformation features. ARIA's rapid response products were shared through Southern California Earthquake Center's response website and the California Earthquake Clearinghouse. A damage proxy map derived from InSAR coherence of CSK data was produced and distributed on Aug. 27. Field crews from the CGS identified true and false positives, including mobile home damage, newly planted grape vines, and a cripple wall failure of a house. Finite fault slip models constrained from CSK interferograms and continuous GPS observations reveal a north-propagating rupture with well-resolved slip from 0-10.5 km depth. We also measured along-track coseismic displacements of about -30 to 30 cm, along the main surface rupture, using multiple aperture interferometry and SAR pixel offset calculation. We also processed the European Space Agency's Sentinel-1A data on Sep. 3 and compared the result with the CSK interferogram, finding a general agreement between the two observations of surface deformation.

Interaction of aromatic amines with iron oxides: implications for prebiotic chemistry.

PubMed

Shanker, Uma; Singh, Gurinder; Kamaluddin

2013-06-01

The interaction of aromatic amines (aniline, p-chloroaniline, p-toludine and p-anisidine) with iron oxides (goethite, akaganeite and hematite) has been studied. Maximum uptake of amines was observed around pH 7. The adsorption data obtained at neutral pH were found to follow Langmuir adsorption. Anisidine was found to be a better adsorbate probably due to its higher basicity. In alkaline medium (pH > 8), amines reacted on goethite and akaganeite to give colored products. Analysis of the products by GC-MS showed benzoquinone and azobenzene as the reaction products of aniline while p-anisidine afforded a dimer. IR analysis of the amine-iron oxide hydroxide adduct suggests that the surface acidity of iron oxide hydroxides is responsible for the interaction. The present study suggests that iron oxide hydroxides might have played a role in the stabilization of organic molecules through their surface activity and in prebiotic condensation reactions.

Effects and interactions of medium components on laccase from a marine-derived fungus using response surface methodology.

PubMed

D'Souza-Ticlo, Donna; Garg, Sandeep; Raghukumar, Chandralata

2009-11-25

The effects of various synthetic medium components and their interactions with each other ultimately impact laccase production in fungi. This was studied using a laccase-hyper-producing marine-derived basidiomycete, Cerrena unicolor MTCC 5159. Inducible laccases were produced in the idiophase only after addition of an inducer such as CuSO(4). Concentration of carbon and nitrogen acted antagonistically with respect to laccase production. A combination of low nitrogen and high carbon concentration favored both biomass and laccase production. The most favorable combination resulted in 917 U L(-1) of laccase. After sufficient growth had occurred, addition of a surfactant such as Tween 80 positively impacted biomass and increased the laccase activity to around 1,300 U L(-1). Increasing the surface to volume ratio of the culture vessel further increased its activity to almost 2,000 U L(-1).

Optimization of culture conditions for penicilazaphilone C production by a marine-derived fungus Penicillium sclerotiorum M-22.

PubMed

Zhao, H-G; Wang, M; Lin, Y-Y; Zhou, S-L

2018-03-01

The aim of this study was to optimize the culture conditions of a marine-derived fungus Penicillium sclerotiorum M-22 for the production of penicilazaphilone C (PAC), a novel azaphilonidal derivative exhibiting broad cytotoxic and antibacterial effects. By single factor experiments, the effects to the production of PAC of aged seawater concentration, initial pH values, fermentation time, carbon sources, nitrogen sources and inorganic salt sources were investigated individually. Response surface methodology (RSM) analysis was adopted to investigate the interactions between variables and determine the optimal values for maximum PAC production. Evaluation of the experimental results signified that the optimum conditions for maximum production of PAC (19·85 mg l -1 ) in 250 ml Erlenmeyer flask were fermentation time 24·83 days, pH of 7·00, corn meal concentration of 10·72 g l -1 , yeast extract concentration of 4·58 g l -1 , crude sea salt concentration of 20·59 g l -1 . Production under optimized conditions increased to 1·344-fold comparing to its production prior to optimization. The higher PAC production and the penicilazaphilone C -producing marine fungus would be provide a promising alterative approach for industrial and commercial applications. Penicilazaphilone C (PAC) was a novel azaphilonidal derivative which had exhibited selective cytotoxicity and antibacterial activity. To further enhance production of PAC by optimizing fermentation conditions of Penicillium sclerotiorum M-22 would provide a promising alterative approach for industrial and commercial applications. We used the single factor test to determine the key factors which influence the PAC production. Then through the Response surface methodology and Box-Behnken design to determine the best fermentation condition for maximum production of PAC. Through these experimental designs and analysis will help us improve experimental efficiency and save time and materials. © 2017 The Society for Applied Microbiology.

G protein-coupled receptors: the inside story.

PubMed

Jalink, Kees; Moolenaar, Wouter H

2010-01-01

Recent findings necessitate revision of the traditional view of G protein-coupled receptor (GPCR) signaling and expand the diversity of mechanisms by which receptor signaling influences cell behavior in general. GPCRs elicit signals at the plasma membrane and are then rapidly removed from the cell surface by endocytosis. Internalization of GPCRs has long been thought to serve as a mechanism to terminate the production of second messengers such as cAMP. However, recent studies show that internalized GPCRs can continue to either stimulate or inhibit cAMP production in a sustained manner. They do so by remaining associated with their cognate G protein subunit and adenylyl cyclase at endosomal compartments. Once internalized, the GPCRs produce cellular responses distinct from those elicited at the cell surface.

Laser pulse bidirectional reflectance from CALIPSO mission

NASA Astrophysics Data System (ADS)

Lu, Xiaomei; Hu, Yongxiang; Yang, Yuekui; Vaughan, Mark; Liu, Zhaoyan; Rodier, Sharon; Hunt, William; Powell, Kathy; Lucker, Patricia; Trepte, Charles

2018-06-01

This paper presents an innovative retrieval method that translates the CALIOP land surface laser pulse returns into the surface bidirectional reflectance. To better analyze the surface returns, the CALIOP receiver impulse response and the downlinked samples' distribution at 30 m vertical resolution are discussed. The saturated laser pulse magnitudes from snow and ice surfaces are recovered based on information extracted from the tail end of the surface signal. The retrieved snow surface bidirectional reflectance is compared with reflectance from both CALIOP cloud-covered regions and MODIS BRDF-albedo model parameters. In addition to the surface bidirectional reflectance, the column top-of-atmosphere bidirectional reflectances are calculated from the CALIOP lidar background data and compared with the bidirectional reflectances derived from WFC radiance measurements. The retrieved CALIOP surface bidirectional reflectance and column top-of-atmosphere bidirectional reflectance results provide unique information to complement existing MODIS standard data products and are expected to have valuable applications for modelers.

Optimization of Coolant Technique Conditions for Machining A319 Aluminium Alloy Using Response Surface Method (RSM)

NASA Astrophysics Data System (ADS)

Zainal Ariffin, S.; Razlan, A.; Ali, M. Mohd; Efendee, A. M.; Rahman, M. M.

2018-03-01

Background/Objectives: The paper discusses about the optimum cutting parameters with coolant techniques condition (1.0 mm nozzle orifice, wet and dry) to optimize surface roughness, temperature and tool wear in the machining process based on the selected setting parameters. The selected cutting parameters for this study were the cutting speed, feed rate, depth of cut and coolant techniques condition. Methods/Statistical Analysis Experiments were conducted and investigated based on Design of Experiment (DOE) with Response Surface Method. The research of the aggressive machining process on aluminum alloy (A319) for automotive applications is an effort to understand the machining concept, which widely used in a variety of manufacturing industries especially in the automotive industry. Findings: The results show that the dominant failure mode is the surface roughness, temperature and tool wear when using 1.0 mm nozzle orifice, increases during machining and also can be alternative minimize built up edge of the A319. The exploration for surface roughness, productivity and the optimization of cutting speed in the technical and commercial aspects of the manufacturing processes of A319 are discussed in automotive components industries for further work Applications/Improvements: The research result also beneficial in minimizing the costs incurred and improving productivity of manufacturing firms. According to the mathematical model and equations, generated by CCD based RSM, experiments were performed and cutting coolant condition technique using size nozzle can reduces tool wear, surface roughness and temperature was obtained. Results have been analyzed and optimization has been carried out for selecting cutting parameters, shows that the effectiveness and efficiency of the system can be identified and helps to solve potential problems.

Use of Response Surface Methodology to Optimize Culture Conditions for Hydrogen Production by an Anaerobic Bacterial Strain from Soluble Starch

NASA Astrophysics Data System (ADS)

Kieu, Hoa Thi Quynh; Nguyen, Yen Thi; Dang, Yen Thi; Nguyen, Binh Thanh

2016-05-01

Biohydrogen is a clean source of energy that produces no harmful byproducts during combustion, being a potential sustainable energy carrier for the future. Therefore, biohydrogen produced by anaerobic bacteria via dark fermentation has attracted attention worldwide as a renewable energy source. However, the hydrogen production capability of these bacteria depends on major factors such as substrate, iron-containing hydrogenase, reduction agent, pH, and temperature. In this study, the response surface methodology (RSM) with central composite design (CCD) was employed to improve the hydrogen production by an anaerobic bacterial strain isolated from animal waste in Phu Linh, Soc Son, Vietnam (PL strain). The hydrogen production process was investigated as a function of three critical factors: soluble starch concentration (8 g L-1 to 12 g L-1), ferrous iron concentration (100 mg L-1 to 200 mg L-1), and l-cysteine concentration (300 mg L-1 to 500 mg L-1). RSM analysis showed that all three factors significantly influenced hydrogen production. Among them, the ferrous iron concentration presented the greatest influence. The optimum hydrogen concentration of 1030 mL L-1 medium was obtained with 10 g L-1 soluble starch, 150 mg L-1 ferrous iron, and 400 mg L-1 l-cysteine after 48 h of anaerobic fermentation. The hydrogen concentration produced by the PL strain was doubled after using RSM. The obtained results indicate that RSM with CCD can be used as a technique to optimize culture conditions for enhancement of hydrogen production by the selected anaerobic bacterial strain. Hydrogen production from low-cost organic substrates such as soluble starch using anaerobic fermentation methods may be one of the most promising approaches.

Garcina cambogia leaf and seawater for tannase production by marine Aspergillus awamori BTMFW032 under slurry state fermentation.

PubMed

Beena, S P; Basheer, Soorej M; Bhat, Sarita G; Chandrasekaran, M

2011-12-01

Garcinia gummi-gutta (syn. G. cambogia, G. quaesita), known to have medicinal properties, was evaluated as a substrate and inducer for tannase production by a marine Aspergillus awamori BTMFW032, under slurry state fermentation using Czapekdox-minimal medium and sea water as the cultivation medium. Among the various natural tannin substrates evaluated, Garcinia leaf supported maximal tannase production. The cultivation conditions and components of the cultivation medium were optimized employing response surface methodology. The experimental results were fitted to a second-order polynomial model at a 92.2% level of significance (p < 0.0001). The maximal tannase activity was obtained in a slurry state medium containing 26.6%, w/v, Garcinia leaf, supplemented with 0.1% tannic acid as inducer. The optimum values of pH, temperature and inoculum concentration obtained were 5.0, 40 degrees C and 3%, respectively. A Box-Behnken model study of the fermentation conditions was carried out, and the best production of tannase was registered at 40 degrees C without agitation. Optimization strategy employing response surface methodology led to nearly 3-fold increase in the enzyme production from 26.2 U/mL obtained in unoptimized medium to 75.2 Units/mL in Box Behnken design, within 18 h of fermentation. It was observed that sea water could support maximal tannase production by A. awamori compared with other media suggesting that the sea water salts could have played an inducer role in expression of tannase encoding genes. To the best of our knowledge, this is the first report on production of tannase, an industrially important enzyme, utilizing Garcinia leaf as substrate under slurry state fermentation by marine A. awamori and sea water as the cultivation medium.

Biogeochemical controls on microbial CH4 and CO2 production in Arctic polygon tundra

NASA Astrophysics Data System (ADS)

Zheng, J.

2016-12-01

Accurately simulating methane (CH4) and carbon dioxide (CO2) emissions from high latitude soils is critically important for reducing uncertainties in soil carbon-climate feedback predictions. The signature polygonal ground of Arctic tundra generates high level of heterogeneity in soil thermal regime, hydrology and oxygen availability, which limits the application of current land surface models with simple moisture response functions. We synthesized CH4 and CO2 production measurements from soil microcosm experiments across a wet-to dry permafrost degradation gradient from low-centered (LCP) to flat-centered (FCP), and high-centered polygons (HCP) to evaluate the relative importance of biogeochemical processes and their response to warming. More degraded polygon (HCP) showed much less carbon loss as CO2 or CH4, while the total CO2 production from FCP is comparable to that from LCP. Maximum CH4 production from the active layer of LCP was nearly 10 times that of permafrost and FCP. Multivariate analyses identifies gravimetric water content and organic carbon content as key predictors for CH4 production, and iron reduction as a key regulator of pH. The synthesized data are used to validate the geochemical model PHREEQC with extended anaerobic organic substrate turnover, fermentation, iron reduction, and methanogenesis reactions. Sensitivity analyses demonstrate that better representations of anaerobic processes and their pH dependency could significantly improve estimates of CH4 and CO2 production. The synthesized data suggest local decreases in CH4 production along the polygon degradation gradient, which is consistent with previous surface flux measurements. Methane oxidation occurring through the soil column of degraded polygons contributes to their low CH4 emissions as well.

The Effect of Atrazine on Louisiana Gulf Coast Estuarine Phytoplankton.

PubMed

Starr, Alexis V; Bargu, Sibel; Maiti, Kanchan; DeLaune, Ronald D

2017-02-01

Pesticides may enter water bodies in areas with a high proportion of agricultural land use through surface runoff, groundwater discharge, and erosion and thus negatively impact nontarget aquatic organisms. The herbicide atrazine is used extensively throughout the Midwest and enters the Mississippi River through surface runoff and groundwater discharge. The purpose of this study was to determine the extent of atrazine contamination in Louisiana's estuaries from Mississippi River water under different flow and nutrient regimes (spring and summer) and its effect on the biomass and oxygen production of the local phytoplankton community. The results showed that atrazine was consistently present in these systems at low levels. Microcosm experiments exposed to an atrazine-dilution series under low and high nutrient conditions to determine the phytoplankton stress response showed that high atrazine levels greatly decreased phytoplankton biomass and oxygen production. Phytoplankton exposed to low and moderate atrazine levels under high nutrient conditions were able to recover after an extended acclimation period. Communities grown under high nutrient conditions grew more rapidly and produced greater levels of oxygen than the low nutrient treatment groups, thus indicating that atrazine exposure may induce a greater stress response in phytoplankton communities under low-nutrient conditions. The native community also experienced a shift from more sensitive species, such as chlorophytes, to potentially more resilient species such as diatoms. The phytoplankton response to atrazine exposure at various concentrations can be especially important to greater trophic levels because their growth and abundance can determine the potential productivity of the entire ecosystem.

Reactive oxygen species (ROS) induced cytokine production and cytotoxicity of PAMAM dendrimers in J774A.1 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naha, Pratap C., E-mail: pratap.naha@dit.i; NanoLab, Focas Research Institute, Dublin Institute of Technology, Kevin Street, Dublin 8; Davoren, Maria

2010-07-15

The immunotoxicity of three generations of polyamidoamine (PAMAM) dendrimers (G-4, G-5 and G-6) was evaluated in mouse macrophage cells in vitro. Using the Alamar blue and MTT assays, a generation dependent cytotoxicity of the PAMAM dendrimers was found whereby G-6 > G-5 > G-4. The toxic response of the PAMAM dendrimers correlated well with the number of surface primary amino groups, with increasing number resulting in an increase in toxic response. An assessment of intracellular ROS generation by the PAMAM dendrimers was performed by measuring the increased fluorescence as a result of intracellular oxidation of Carboxy H{sub 2}DCFDA to DCFmore » both quantitatively using plate reader and qualitatively by confocal laser scanning microscopy. The inflammatory mediators macrophage inflammatory protein-2 (MIP-2), tumour necrosis factor-{alpha} (TNF-{alpha}) and interleukin-6, (IL-6) were measured by the enzyme linked immunosorbant assay (ELISA) following exposure of mouse macrophage cells to PAMAM dendrimers. A generation dependent ROS and cytokine production was found, which correlated well with the cytotoxicological response and therefore number of surface amino groups. A clear time sequence of increased ROS generation (maximum at {approx} 4 h), TNF-{alpha} and IL-6 secretion (maximum at {approx} 24 h), MIP-2 levels and cell death ({approx} 72 h) was observed. The intracellular ROS generation and cytokine production induced cytotoxicity point towards the mechanistic pathway of cell death upon exposure to PAMAM dendrimers.« less

A novel model to assess the efficacy of steam surface pasteurization of cooked surimi gels inoculated with realistic levels of Listeria innocua.

PubMed

Skåra, Torstein; Valdramidis, Vasilis P; Rosnes, Jan Thomas; Noriega, Estefanía; Van Impe, Jan F M

2014-12-01

Steam surface pasteurization is a promising decontamination technology for reducing pathogenic bacteria in different stages of food production. The effect of the artificial inoculation type and initial microbial load, however, has not been thoroughly assessed in the context of inactivation studies. In order to optimize the efficacy of the technology, the aim of this study was to design and validate a model system for steam surface pasteurization, assessing different inoculation methods and realistic microbial levels. More specifically, the response of Listeria innocua, a surrogate organism of Listeria monocytogenes, on a model fish product, and the effect of different inoculation levels following treatments with a steam surface pasteurization system was investigated. The variation in the resulting inoculation level on the samples was too large (77%) for the contact inoculation procedure to be further considered. In contrast, the variation of a drop inoculation procedure was 17%. Inoculation with high levels showed a rapid 1-2 log decrease after 3-5 s, and then no further inactivation beyond 20 s. A low level inoculation study was performed by analysing the treated samples using a novel contact plating approach, which can be performed without sample homogenization and dilution. Using logistic regression, results from this method were used to model the binary responses of Listeria on surfaces with realistic inoculation levels. According to this model, a treatment time of 23 s will result in a 1 log reduction (for P = 0.1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Reconstruction of surface water conditions in the central region of the Okhotsk Sea during the last 180 kyrs

NASA Astrophysics Data System (ADS)

Khim, Boo-Keun; Sakamoto, Tatsuhiko; Harada, Naomi

2012-02-01

Core GC9A, a 6.7 m long gravity core collected from the central region of the Okhotsk Sea during Cruise YK0712 on R/V Yokosuka (JAMSTEC), was used to reconstruct the changes in surface water conditions by measuring biogenic components (biogenic opal, CaCO3, total organic carbon and δ15N of sediment organic matter) of sediment samples. The age of Core GC9A was determined indirectly by graphic correlation comparing the b* (psychometric yellow-blue chromaticness) values with those of well-dated Core MD01-2415, with complement to the tephra layer (K3; 50 ka). The bottom age of Core GC9A was estimated to be about 180 kyr; therefore it provides the history of surface water conditions from MIS 1 to MIS 6. The biogenic opal, CaCO3, and TOC contents were high during the interglacial periods as expected, indicating enhanced surface water production under warm climatic conditions. This condition resulted from sufficient nutrient supply to the surface waters by active vertical mixing, which was validated by low δ15N values of the sediment organic matter. In contrast, surface water productivity was depressed during the colder glacial periods, probably due to the expanded sea-ice distribution and limited nutrient supply. However, the glacial sediments had moderately high δ15N values, indicating enhanced nitrate utilization resulting from the limited nutrient supply caused by strong stratification of the surface water. High δ15N values were also observed during the deglaciation, which was attributed to the increased nitrate utilization during enhanced surface water productivity. However, the low δ15N values during the glacial and deglacial periods may be attributed to the increased supply of terrestrial organic matter. Diatom production was primarily responsible for surface water paleoproductivity during the interglacial periods rather than coccolithophores. However, the succession of glacial to early deglacial coccolithophore production and late deglacial to interglacial diatom production was remarkable, corresponding to the present-day seasonal phytoplankton succession. Such an advanced coccolithophore production relative to diatom production might be attributed to the degree of nutrient availability associated with surface water conditions on the basis of variations in the δ15N value. Finally, the opal and TOC contents decreased abruptly in conjunction with a gradual decrease in CaCO3 content from about 2 ka, which seems to implicate a late Holocene sudden decrease in paleoproductivity in the central region of the Okhotsk Sea. According to the increase in δ15N values during this interval, nutrient availability appears to be poor, which is likely attributed to the resumed strong stratification that occurred due to the southward shift of the Aleutian Low atmospheric pressure system.

Optimization of biotransformation from phytosterol to androstenedione by a mutant Mycobacterium neoaurum ZJUVN-08.

PubMed

Zhang, Xiao-yan; Peng, Yong; Su, Zhong-rui; Chen, Qi-he; Ruan, Hui; He, Guo-qing

2013-02-01

Biotransformation of phytosterol (PS) by a newly isolated mutant Mycobacterium neoaurum ZJUVN-08 to produce androstenedione has been investigated in this paper. The parameters of the biotransformation process were optimized using fractional factorial design and response surface methodology. Androstenedione was the sole product in the fermentation broth catalyzed by the mutant M. neoaurum ZJUVN-08 strain. Results showed that molar ratio of hydroxypropyl-β-cyclodextrin (HP-β-CD) to PS and substrate concentrations were the two most significant factors affecting androstenedione production. By analyzing the statistical model of three-dimensional surface plot, the optimal process conditions were observed at 0.1 g/L inducer, pH 7.0, molar ratio of HP-β-CD to PS 1.92:1, 8.98 g/L PS, and at 120 h of incubation time. Under these conditions, the maximum androstenedione yield was 5.96 g/L and nearly the same with the non-optimized (5.99 g/L), while the maximum PS conversion rate was 94.69% which increased by 10.66% compared with the non-optimized (84.03%). The predicted optimum conditions from the mathematical model were in agreement with the verification experimental results. It is considered that response surface methodology was a powerful and efficient method to optimize the parameters of PS biotransformation process.

Optimization of biotransformation from phytosterol to androstenedione by a mutant Mycobacterium neoaurum ZJUVN-08*

PubMed Central

Zhang, Xiao-yan; Peng, Yong; Su, Zhong-rui; Chen, Qi-he; Ruan, Hui; He, Guo-qing

2013-01-01

Biotransformation of phytosterol (PS) by a newly isolated mutant Mycobacterium neoaurum ZJUVN-08 to produce androstenedione has been investigated in this paper. The parameters of the biotransformation process were optimized using fractional factorial design and response surface methodology. Androstenedione was the sole product in the fermentation broth catalyzed by the mutant M. neoaurum ZJUVN-08 strain. Results showed that molar ratio of hydroxypropyl-β-cyclodextrin (HP-β-CD) to PS and substrate concentrations were the two most significant factors affecting androstenedione production. By analyzing the statistical model of three-dimensional surface plot, the optimal process conditions were observed at 0.1 g/L inducer, pH 7.0, molar ratio of HP-β-CD to PS 1.92:1, 8.98 g/L PS, and at 120 h of incubation time. Under these conditions, the maximum androstenedione yield was 5.96 g/L and nearly the same with the non-optimized (5.99 g/L), while the maximum PS conversion rate was 94.69% which increased by 10.66% compared with the non-optimized (84.03%). The predicted optimum conditions from the mathematical model were in agreement with the verification experimental results. It is considered that response surface methodology was a powerful and efficient method to optimize the parameters of PS biotransformation process. PMID:23365012

Methods for the preparation of protein-oligonucleotide-lipid constructs.

PubMed

Takasaki, Jennifer; Raney, Sameersingh G; Chikh, Ghania; Sekirov, Laura; Brodsky, Irina; Tam, Ying; Ansell, Steven M

2006-01-01

A mixture of ionizable cationic lipids, steric barrier lipids, and colipids is used to encapsulate oligonucleotide DNA in lipidic particles called SALP. This material is under development as an adjuvant for vaccines. Previously we have shown that coupling the antigen directly to the surface of SALP can lead to enhanced immunological responses in vivo. Two different methods for preparing ovalbumin-SALP were assessed in this work. Originally the conjugates were prepared by treating SALP containing a maleimide-derivatized lipid with thiolated ovalbumin, a method we refer to as active coupling. This reaction was found to be difficult to control and generally resulted in low coupling efficiencies. The issues relating to this approach were characterized. We have recently developed alternative techniques based on first coupling ovalbumin to a micelle and then incubating the resultant product with SALP, methods we refer to as passive coupling. We have shown that this method allows accurate control of the levels of protein associated SALP and does not suffer from surface saturation effects seen with the active coupling method that places maximum limits on the amount of protein that can be coupled to the SALP surface. The products from the passive coupling protocol are shown to have activity comparable to those derived from the active coupling protocol in investigations of in vivo immune responses.

Formulation development and optimization of sustained release matrix tablet of Itopride HCl by response surface methodology and its evaluation of release kinetics

PubMed Central

Bose, Anirbandeep; Wong, Tin Wui; Singh, Navjot

2012-01-01

The objective of this present investigation was to develop and formulate sustained release (SR) matrix tablets of Itopride HCl, by using different polymer combinations and fillers, to optimize by Central Composite Design response surface methodology for different drug release variables and to evaluate drug release pattern of the optimized product. Sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: hydroxy propyl methyl cellulose (HPMC) and polyvinyl pyrolidine (pvp) and lactose as fillers. Study of pre-compression and post-compression parameters facilitated the screening of a formulation with best characteristics that underwent here optimization study by response surface methodology (Central Composite Design). The optimized tablet was further subjected to scanning electron microscopy to reveal its release pattern. The in vitro study revealed that combining of HPMC K100M (24.65 MG) with pvp(20 mg)and use of LACTOSE as filler sustained the action more than 12 h. The developed sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet. PMID:23960836

Physical stability assessment and sensory optimization of a dairy-free emulsion using response surface methodology.

PubMed

Granato, Daniel; de Castro, I Alves; Ellendersen, L Souza Neves; Masson, M Lucia

2010-04-01

Desserts made with soy cream, which are oil-in-water emulsions, are widely consumed by lactose-intolerant individuals in Brazil. In this regard, this study aimed at using response surface methodology (RSM) to optimize the sensory attributes of a soy-based emulsion over a range of pink guava juice (GJ: 22% to 32%) and soy protein (SP: 1% to 3%). WHC and backscattering were analyzed after 72 h of storage at 7 degrees C. Furthermore, a rating test was performed to determine the degree of liking of color, taste, creaminess, appearance, and overall acceptability. The data showed that the samples were stable against gravity and storage. The models developed by RSM adequately described the creaminess, taste, and appearance of the emulsions. The response surface of the desirability function was used successfully in the optimization of the sensory properties of dairy-free emulsions, suggesting that a product with 30.35% GJ and 3% SP was the best combination of these components. The optimized sample presented suitable sensory properties, in addition to being a source of dietary fiber, iron, copper, and ascorbic acid.

Optimization of Bromelain-Aided Production of Angiotensin I-Converting Enzyme Inhibitory Hydrolysates from Stone Fish Using Response Surface Methodology.

PubMed

Muhammad Auwal, Shehu; Zarei, Mohammad; Abdul-Hamid, Azizah; Saari, Nazamid

2017-03-31

The stone fish is an under-utilized sea cucumber with many nutritional and ethno-medicinal values. This study aimed to establish the conditions for its optimum hydrolysis with bromelain to generate angiotensin I-converting enzyme (ACE)-inhibitory hydrolysates. Response surface methodology (RSM) based on a central composite design was used to model and optimize the degree of hydrolysis (DH) and ACE-inhibitory activity. Process conditions including pH (4-7), temperature (40-70 °C), enzyme/substrate (E/S) ratio (0.5%-2%) and time (30-360 min) were used. A pH of 7.0, temperature of 40 °C, E/S ratio of 2% and time of 240 min were determined using a response surface model as the optimum levels to obtain the maximum ACE-inhibitory activity of 84.26% at 44.59% degree of hydrolysis. Hence, RSM can serve as an effective approach in the design of experiments to improve the antihypertensive effect of stone fish hydrolysates, which can thus be used as a value-added ingredient for various applications in the functional foods industries.

Formulation development and optimization of sustained release matrix tablet of Itopride HCl by response surface methodology and its evaluation of release kinetics.

PubMed

Bose, Anirbandeep; Wong, Tin Wui; Singh, Navjot

2013-04-01

The objective of this present investigation was to develop and formulate sustained release (SR) matrix tablets of Itopride HCl, by using different polymer combinations and fillers, to optimize by Central Composite Design response surface methodology for different drug release variables and to evaluate drug release pattern of the optimized product. Sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: hydroxy propyl methyl cellulose (HPMC) and polyvinyl pyrolidine (pvp) and lactose as fillers. Study of pre-compression and post-compression parameters facilitated the screening of a formulation with best characteristics that underwent here optimization study by response surface methodology (Central Composite Design). The optimized tablet was further subjected to scanning electron microscopy to reveal its release pattern. The in vitro study revealed that combining of HPMC K100M (24.65 MG) with pvp(20 mg)and use of LACTOSE as filler sustained the action more than 12 h. The developed sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet.

Response surface optimization of low-fat ice cream production by using resistant starch and maltodextrin as a fat replacing agent.

PubMed

Azari-Anpar, Mojtaba; Khomeiri, Morteza; Ghafouri-Oskuei, Hamed; Aghajani, Narjes

2017-04-01

In this research, maltodextrin (0, 1 and 2% w/w) and resistant starch (0, 1 and 2% w/w) were used in the formulation of low-fat ice cream (4% fat) and their effects on the physicochemical and sensory properties were investigated. The optimum levels of maltodextrin and resistant starch were determined by response surface methodology. Increment of maltodextrin and resistant starch increased acidity, viscosity, melting rate, time of dripping and overrun but decreased melting rate of ice cream. Results showed that the incorporation of maltodextrin and resistant starch at 0 and 2% w/w respectively, resulted into ice cream with suitable viscosity, melting rate, first dripping time, overrun and acidity.

Improvement of erythrose reductase activity, deletion of by-products and statistical media optimization for enhanced erythritol production from Yarrowia lipolytica mutant 49.

PubMed

Ghezelbash, Gholam Reza; Nahvi, Iraj; Emamzadeh, Rahman

2014-08-01

The purpose of the present investigation was to produce erythritol by Yarrowia lipolytica mutant without any by-products. Mutants of Y. lipolytica were generated by ultra-violet for enhancing erythrose reductase (ER) activity and erythritol production. The mutants showing the highest ER activity were screened by triphenyl tetrazolium chloride agar plate assay. Productivity of samples was analyzed by thin-layer chromatography and high-performance liquid chromatography equipped with the refractive index detector. One of the mutants named as mutant 49 gave maximum erythritol production without any other by-products (particularly glycerol). Erythritol production and specific ER activity in mutant 49 increased to 1.65 and 1.47 times, respectively, in comparison with wild-type strain. The ER gene of wild and mutant strains was sequenced and analyzed. A general comparison of wild and mutant gene sequences showed the replacement of Asp(270) with Glu(270) in ER protein. In order to enhance erythritol production, we used a three component-three level-one response Box-Behnken of response surface methodology model. The optimum medium composition for erythritol production was found to be (g/l) glucose 279.49, ammonium sulfate 9.28, and pH 5.41 with 39.76 erythritol production.

State of the art satellite and airborne marine oil spill remote sensing: Application to the BP Deepwater Horizon oil spill

USGS Publications Warehouse

Leifer, Ira; Lehr, William J.; Simecek-Beatty, Debra; Bradley, Eliza; Clark, Roger N.; Dennison, Philip E.; Hu, Yongxiang; Matheson, Scott; Jones, Cathleen E; Holt, Benjamin; Reif, Molly; Roberts, Dar A.; Svejkovsky, Jan; Swayze, Gregg A.; Wozencraft, Jennifer M.

2012-01-01

The vast and persistent Deepwater Horizon (DWH) spill challenged response capabilities, which required accurate, quantitative oil assessment at synoptic and operational scales. Although experienced observers are a spill response's mainstay, few trained observers and confounding factors including weather, oil emulsification, and scene illumination geometry present challenges. DWH spill and impact monitoring was aided by extensive airborne and spaceborne passive and active remote sensing.Oil slick thickness and oil-to-water emulsion ratios are key spill response parameters for containment/cleanup and were derived quantitatively for thick (> 0.1 mm) slicks from AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data using a spectral library approach based on the shape and depth of near infrared spectral absorption features. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite, visible-spectrum broadband data of surface-slick modulation of sunglint reflection allowed extrapolation to the total slick. A multispectral expert system used a neural network approach to provide Rapid Response thickness class maps.Airborne and satellite synthetic aperture radar (SAR) provides synoptic data under all-sky conditions; however, SAR generally cannot discriminate thick (> 100 μm) oil slicks from thin sheens (to 0.1 μm). The UAVSAR's (Uninhabited Aerial Vehicle SAR) significantly greater signal-to-noise ratio and finer spatial resolution allowed successful pattern discrimination related to a combination of oil slick thickness, fractional surface coverage, and emulsification.In situ burning and smoke plumes were studied with AVIRIS and corroborated spaceborne CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations of combustion aerosols. CALIPSO and bathymetry lidar data documented shallow subsurface oil, although ancillary data were required for confirmation.Airborne hyperspectral, thermal infrared data have nighttime and overcast collection advantages and were collected as well as MODIS thermal data. However, interpretation challenges and a lack of Rapid Response Products prevented significant use. Rapid Response Products were key to response utilization—data needs are time critical; thus, a high technological readiness level is critical to operational use of remote sensing products. DWH's experience demonstrated that development and operationalization of new spill response remote sensing tools must precede the next major oil spill.

Subcritical water liquefaction of oil palm fruit press fiber in the presence of sodium hydroxide: an optimisation study using response surface methodology.

PubMed

Mazaheri, Hossein; Lee, Keat Teong; Bhatia, Subhash; Mohamed, Abdul Rahman

2010-12-01

Thermal decomposition of oil palm fruit press fiber (FPF) into a liquid product (LP) was achieved using subcritical water treatment in the presence of sodium hydroxide in a high pressure batch reactor. This study uses experimental design and process optimisation tools to maximise the LP yield using response surface methodology (RSM) with central composite rotatable design (CCRD). The independent variables were temperature, residence time, particle size, specimen loading, and additive loading. The mathematical model that was developed fit the experimental results well for all of the response variables that were studied. The optimal conditions were found to be a temperature of 551 K, a residence time of 40 min, a particle size of 710-1000 microm, a specimen loading of 5 g, and a additive loading of 9 wt.% to achieve a LP yield of 76.16%. 2010 Elsevier Ltd. All rights reserved.

Fluid shear stress stimulates prostaglandin and nitric oxide release in bone marrow-derived preosteoclast-like cells

NASA Technical Reports Server (NTRS)

McAllister, T. N.; Du, T.; Frangos, J. A.

2000-01-01

Bone is a porous tissue that is continuously perfused by interstitial fluid. Fluid flow, driven by both vascular pressure and mechanical loading, may generate significant shear stresses through the canaliculi as well as along the bone lining at the endosteal surface. Both osteoblasts and osteocytes produce signaling factors such as prostaglandins and nitric in response to fluid shear stress (FSS); however, these humoral agents appear to have more profound affects on osteoclast activity at the endosteal surface. We hypothesized that osteoclasts and preosteoclasts may also be mechanosensitive and that osteoclast-mediated autocrine signaling may be important in bone remodeling. In this study, we investigated the effect of FSS on nitric oxide (NO), prostaglandin E(2) (PGE(2)), and prostacyclin (PGI(2)) release by neonatal rat bone marrow-derived preosteoclast-like cells. These cells were tartrate-resistant acid phosphatase (TRAP) positive, weakly nonspecific esterase (NSE) positive, and capable of fusing into calcitonin-responsive, bone-resorbing, multinucleated cells. Bone marrow-derived preosteoclast-like cells exposed for 6 h to a well-defined FSS of 16 dynes/cm(2) produced NO at a rate of 7.5 nmol/mg protein/h, which was 10-fold that of static controls. This response was completely abolished by 100 microM N(G)-amino-L-arginine (L-NAA). Flow also stimulated PGE(2) production (3.9 microg/mg protein/h) and PGI(2) production (220 pg/mg protein/h). L-NAA attenuated flow-induced PGE(2) production by 30%, suggesting that NO may partially modulate PGE(2) production. This is the first report demonstrating that marrow derived cells are sensitive to FSS and that autocrine signaling in these cells may play an important role in load-induced remodeling and signal transduction in bone. Copyright 2000 Academic Press.

Functional anatomy and immunological interactions of ocular surface and adnexa.

PubMed

Paulsen, Friedrich

2008-01-01

This chapter gives an overview about the structures and physiology of the ocular surface and its adnexa and focuses in a second part on the possible meaning of eye-associated lymphoid tissue (EALT) in a context with the development of dry eye. Sections deal with (1) anatomy of the ocular surface, lacrimal gland, eyelid and nasolacrimal ducts. (2) The meaning and importance of the lacrimal functional unit and the function of the mucosal innate immune system are briefly summarized. (3) Finally, the occurrence and the possible function of EALT is discussed with regard to tolerance induction and dry eye. The epithelial surface of the eye and its specialized glandular infoldings produce the components of the tear film, which include water, protective antimicrobials, cytokines, lipids as well as mucins and trefoil factor family (TFF) peptides. Antimicrobials, mucins and TFF peptides perform a number of essential functions which, collectively, provide protection of the ocular surface. Their production changes in cases of dry eye. The development of EALT is a common feature frequently occurring in symptomatically normal conjunctiva and nasolacrimal ducts. The production of antimicrobials, mucins and TFF peptides can be linked with cell signaling, tear film rheology, and antimicrobial defense at the ocular surface. Changes in the production of such peptides and proteins in cases of dry eye support the assumption that these peptides and proteins are involved in the pathophysiological events that occur at the ocular surface and lacrimal apparatus. Whether special types of bacteria, viruses, or other factors, e.g., immune deviation, are responsible for the development of EALT in humans requires further investigation in prospective and experimental studies.

Enhanced thermophilic fermentative hydrogen production from cassava stillage by chemical pretreatments.

PubMed

Wang, Wen; Luo, Gang; Xie, Li; Zhou, Qi

2013-01-01

Acid and alkaline pretreatments for enhanced hydrogen production from cassava stillage were investigated in the present study. The result showed that acid pretreatment was suitable for enhancement of soluble carbohydrate while alkaline pretreatment stimulated more soluble total organic carbon production from cassava stillage. Acid pretreatment thereby has higher capacity to promote hydrogen production compared with alkaline pretreatment. Effects of pretreatment temperature, time and acid concentration on hydrogen production were also revealed by response surface methodology. The results showed that the increase of all factors increased the soluble carbohydrate production, whereas hydrogen production was inhibited when the factors exceeded their optimal values. The optimal conditions for hydrogen production were pretreatment temperature 89.5 °C, concentration 1.4% and time 69 min for the highest hydrogen production of 434 mL, 67% higher than raw cassava stillage.

Statistical optimization of growth medium for the production of the entomopathogenic and phytotoxic cyclic depsipeptide beauvericin from Fusarium oxysporum KFCC 11363P.

PubMed

Lee, Hee-Seok; Song, Hyuk-Hwan; An, Joong-Hoon; Shin, Cha-Gyun; Lee, Gung Pyo; Lee, Chan

2008-01-01

The production of the entomopathogenic and phytotoxic cyclic depsipeptide beauvericin (BEA) was studied in submerged cultures of Fusarium oxysporum KFCC 11363P isolated in Korea. The influences of various factors on mycelia growth and BEA production were examined in both complete and chemically defined culture media. The mycelia growth and BEA production were highest in Fusarium defined medium. The optimal carbon and nitrogen sources for maximizing BEA production were glucose and NaNO3, respectively. The carbon/ nitrogen ratio for maximal production of BEA was investigated using response surface methodology (RSM). Equations derived by differentiation of the RSM model revealed that the production of BEA was maximal when using 108 mM glucose and 25 mM NaNO3.

Palm-based medium-and-long-chain triacylglycerol (P-MLCT): production via enzymatic interesterification and optimization using response surface methodology (RSM).

PubMed

Lee, Yee-Ying; Tang, Teck-Kim; Phuah, Eng-Tong; Karim, Nur Azwani Ab; Alwi, Siti Maslina Mohd; Lai, Oi-Ming

2015-02-01

Structured lipid such as medium-and long-chain triacylglycerol (MLCT) is claimed to be able to suppress body fat accumulation and be used to manage obesity. Response surface methodology (RSM) with four factors and three levels (+1,0,-1) faced centered composite design (FCCD) was employed for optimization of the enzymatic interesterification conditions of palm-based MLCT (P-MLCT) production. The effect of the four variables namely: substrate ratio palm kernel oil: palm oil, PKO:PO (40:60-100:0 w/w), temperature (50-70 °C), reaction time (0.5-7.5 h) and enzyme load (5-15 % w/w) on the P-MLCT yield (%) and by products (%) produced were investigated. The responses were determined via acylglycerol composition obtained from high performance liquid chromatography. Well-fitted models were successfully established for both responses: P-MLCT yield (R (2) = 0.9979) and by-products (R (2) = 0.9892). The P-MLCT yield was significantly (P < 0.05) affected by substrate ratio, reaction time and reaction temperature but not enzyme load (P > 0.05). Substrate ratio PKO: PO (100:0 w/w) gave the highest yield of P-MLCT (61 %). Nonetheless, substrate ratio of PKO: PO (90:10w/w) was chosen to improve the fatty acid composition of the P-MLCT. The optimized conditions for substrate ratio PKO: PO (90:10 w/w) was 7.26 h, 50 °C and 5 % (w/w) Lipozyme TLIM lipase, which managed to give 60 % yields of P-MLCT. Up scaled results in stirred tank batch reactor gave similar yields as lab scale. A 20 % increase in P-MLCT yield was obtained via RSM. The effect of enzymatic interesterification on the physicochemical properties of PKO:PO (90:10 w/w) were also studied. Thermoprofile showed that the P-MLCT oil melted below body temperature of 37 °C.

Development of T follicular helper cells and their role in disease and immune system.

PubMed

Eivazi, Sadegh; Bagheri, Salman; Hashemzadeh, Mohammad Sadegh; Ghalavand, Majdedin; Qamsari, Elmira Safaie; Dorostkar, Ruhollah; Yasemi, Maryam

2016-12-01

The T follicular helper cells (TFH) are a subset of CD4+ T cells specialized to regulate antibody responses. The production of these cells is associated with the dendritic cells (DCs) and B cells. TFH cells help B cells form germinal centers (GC) differentiate into memory and plasma cells (antibody-secreting cells) as humoral responses. In addition, there is strong evidence that TFH cells play a pivotal role in the development of long-lived humoral immunity. Molecular factors such as transcription factors, surface receptors, cytokine and micro RNAs are involved in the formation of TFH cells. Such TFH cells are diagnosed by transcription factor (BCL-6), surface marker expression (including CXCR5, PD-1, ICOS and CD40L) and a unique cytokine production pattern (such as IL-21 and IL-6). Memory TFH cells, accompanied by memory B cells, are known to be formed during antibody responses. It is now clear that the precise control of TFH cells is critically important for both inducing the optimal affinity maturation of antibody responses and preventing self-reactivity. Exclusive controls of TFH cell function and production are essential for human health. However, it is important to note that excessive activities may lead to autoimmune diseases, while reduced activity often results in immunodeficiency. It has also been shown that TFH cells are associated with cancers such as angioimmunoblastic T-cell lymphoma (AITL), follicular T-cell lymphoma (FTCL) and nonspecific Peripheral T-cell lymphomas (PTCLs). The biology of TFH cells, including their differentiation and transcriptional regulation will be described in the present review. Some of The developments of these cells in immunodeficiency diseases, autoimmunity and cancer will also be taken into account. Copyright © 2016. Published by Elsevier Masson SAS.

Late Holocene SST and primary productivity variations in the northeastern Arabian Sea as a recorder for winter monsoon variability

NASA Astrophysics Data System (ADS)

Böll, Anna; Gaye, Birgit; Lückge, Andreas

2014-05-01

Variability in the oceanic environment of the Arabian Sea region is strongly influenced by the seasonal monsoon cycle of alternating wind directions. Strong south-westerly winds during the summer monsoon induce upwelling of nutrient rich waters along the coast off Somalia, Oman and southwest India, which result in high rates of primary production. In the northeastern Arabian Sea off Pakistan on the other hand, primary production and sea surface temperatures are linked to northeast monsoonal winds that cool the sea surface and drive convective mixing and high surface ocean productivity during the winter season. In this study, we analyzed alkenone-derived sea surface temperature (SST) variations and proxies of primary productivity (organic carbon and δ15N) in a well-laminated sediment core from the Pakistan continental margin to establish the first high-resolution record of winter monsoon variability for the late Holocene. Over the last 2400 years reconstructed SST in the northeastern Arabian Sea decreased whereas productivity increased, imaging a long-term trend of northeast monsoon strengthening in response to insolation-induced southward migration of the Intertropical Convergence Zone. The comparison of our winter monsoon record with records of summer monsoon intensity suggests that summer and winter monsoon strength was essentially anti-correlated over the late Holocene throughout the Asian monsoon system. In addition, SST variations recorded off Pakistan match very well with Northern Hemisphere temperature records supporting the growing body of evidence that Asian climate is linked to Northern Hemisphere climate change. It reveals a consistent pattern of increased summer monsoon activity in the northeastern Arabian Sea during northern hemispheric warm periods (Medieval Warm Period, Roman Warm Period) and strengthened winter monsoon activity during hemispheric colder periods (Little Ice Age).

Increased Mediterranean Magma Production and Volcanism Triggered by the Messinian Salinity Crisis

NASA Astrophysics Data System (ADS)

Sternai, P.; Caricchi, L.; Garcia-Castellanos, D.; Jolivet, L.; Sheldrake, T.; Castelltort, S.

2017-12-01

For more than four decades, large controversies about the causes, effects and timing of the Mediterranean Messinian Salinity Crisis (MSC) have evolved in the light of a continuously growing body of evidences. The igneous response to such extreme event, however, has remained largely unexplored despite known relationships between surface load variations and the production, transfer and eruption of magma. Here, we compile published geochemical data and recognize a two-fold increase of volcanic eruptions from pan-Mediterranean magmatic provinces coinciding with the proposed "shallow-water phase" of the MSC between 5.70-5.33 Ma. Estimates of surface load variations due to the desiccation event corrected for water density change and deposition of salt deposits suggest a net mean lithospheric unloading of up to 15 MPa during the shallow-water phase of the MSC. Because the timescale of interest is too short for changes of the Mediterranean tectonics to significantly affect the bulk of the magma production, we propose that such net surface unloading enhanced the mantle decompression melting and dike formation, in turn causing the observed increase of volcanic events. If correct, the Mediterranean magmatic record provides an independent validation of the "shallow-water" model for the formation of salt deposits and testifies the high sensitivity of the melting of the Earth's interior to the surface forcing.

The nucleoid-associated protein Fis directly modulates the synthesis of cellulose, an essential component of pellicle-biofilms in the phytopathogenic bacterium Dickeya dadantii.

PubMed

Prigent-Combaret, Claire; Zghidi-Abouzid, Ouafa; Effantin, Géraldine; Lejeune, Philippe; Reverchon, Sylvie; Nasser, William

2012-10-01

Bacteria use biofilm structures to colonize surfaces and to survive in hostile conditions, and numerous bacteria produce cellulose as a biofilm matrix polymer. Hence, expression of the bcs operon, responsible for cellulose biosynthesis, must be finely regulated in order to allow bacteria to adopt the proper surface-associated behaviours. Here we show that in the phytopathogenic bacterium, Dickeya dadantii, production of cellulose is required for pellicle-biofilm formation and resistance to chlorine treatments. Expression of the bcs operon is growth phase-regulated and is stimulated in biofilms. Furthermore, we unexpectedly found that the nucleoid-associated protein and global regulator of virulence functions, Fis, directly represses bcs operon expression by interacting with an operator that is absent from the bcs operon of animal pathogenic bacteria and the plant pathogenic bacterium Pectobacterium. Moreover, production of cellulose enhances plant surface colonization by D. dadantii. Overall, these data suggest that cellulose production and biofilm formation may be important factors for surface colonization by D. dadantii and its subsequent survival in hostile environments. This report also presents a new example of how bacteria can modulate the action of a global regulator to co-ordinate basic metabolism, virulence and modifications of lifestyle. © 2012 Blackwell Publishing Ltd.

Recent advances in spacecraft thermal-control materials research.

NASA Technical Reports Server (NTRS)

Zerlaut, G. A.; Gilligan, J. E.; Gates, D. W.

1972-01-01

The state-of-the-art of spacecraft thermal-control materials technology has been significantly advanced during the past 4 years. Selective black coatings are discussed together with black paints, dielectric films on metal surfaces, and white radiator coatings. Criteria for the selection of thermal-control surfaces are considered, giving attention to prelaunch protection, the capability of being measured, reproducibility, simulator response, and aspects of a nonindigenous space environment. Progress in space simulation is related to vacuum technology, ultraviolet sources, solar wind simulation, and the production of protons. Advances have been made in the protection against space environmental effects, and in the development of thermal-control surfaces and pigments.

Extraction Optimization for Obtaining Artemisia capillaris Extract with High Anti-Inflammatory Activity in RAW 264.7 Macrophage Cells

PubMed Central

Jang, Mi; Jeong, Seung-Weon; Kim, Bum-Keun; Kim, Jong-Chan

2015-01-01

Plant extracts have been used as herbal medicines to treat a wide variety of human diseases. We used response surface methodology (RSM) to optimize the Artemisia capillaris Thunb. extraction parameters (extraction temperature, extraction time, and ethanol concentration) for obtaining an extract with high anti-inflammatory activity at the cellular level. The optimum ranges for the extraction parameters were predicted by superimposing 4-dimensional response surface plots of the lipopolysaccharide- (LPS-) induced PGE2 and NO production and by cytotoxicity of A. capillaris Thunb. extracts. The ranges of extraction conditions used for determining the optimal conditions were extraction temperatures of 57–65°C, ethanol concentrations of 45–57%, and extraction times of 5.5–6.8 h. On the basis of the results, a model with a central composite design was considered to be accurate and reliable for predicting the anti-inflammation activity of extracts at the cellular level. These approaches can provide a logical starting point for developing novel anti-inflammatory substances from natural products and will be helpful for the full utilization of A. capillaris Thunb. The crude extract obtained can be used in some A. capillaris Thunb.-related health care products. PMID:26075271

Optimization of Fat-Reduced Puff Pastry Using Response Surface Methodology.

PubMed

Silow, Christoph; Zannini, Emanuele; Axel, Claudia; Belz, Markus C E; Arendt, Elke K

2017-02-22

Puff pastry is a high-fat bakery product with fat playing a key role, both during the production process and in the final pastry. In this study, response surface methodology (RSM) was successfully used to evaluate puff pastry quality for the development of a fat-reduced version. The technological parameters modified included the level of roll-in fat, the number of fat layers (50-200) and the final thickness (1.0-3.5 mm) of the laminated dough. Quality characteristics of puff pastry were measured using the Texture Analyzer with an attached Extended Craft Knife (ECK) and Multiple Puncture Probe (MPP), the VolScan and the C-Cell imaging system. The number of fat layers and final dough thickness, in combination with the amount of roll-in fat, had a significant impact on the internal and external structural quality parameters. With technological changes alone, a fat-reduced (≥30%) puff pastry was developed. The qualities of fat-reduced puff pastries were comparable to conventional full-fat (33 wt %) products. A sensory acceptance test revealed no significant differences in taste of fatness or 'liking of mouthfeel'. Additionally, the fat-reduced puff pastry resulted in a significant ( p < 0.05) positive correlation to 'liking of flavor' and overall acceptance by the assessors.

Optimization of Fat-Reduced Puff Pastry Using Response Surface Methodology

PubMed Central

Silow, Christoph; Zannini, Emanuele; Axel, Claudia; Belz, Markus C. E.; Arendt, Elke K.

2017-01-01

Puff pastry is a high-fat bakery product with fat playing a key role, both during the production process and in the final pastry. In this study, response surface methodology (RSM) was successfully used to evaluate puff pastry quality for the development of a fat-reduced version. The technological parameters modified included the level of roll-in fat, the number of fat layers (50–200) and the final thickness (1.0–3.5 mm) of the laminated dough. Quality characteristics of puff pastry were measured using the Texture Analyzer with an attached Extended Craft Knife (ECK) and Multiple Puncture Probe (MPP), the VolScan and the C-Cell imaging system. The number of fat layers and final dough thickness, in combination with the amount of roll-in fat, had a significant impact on the internal and external structural quality parameters. With technological changes alone, a fat-reduced (≥30%) puff pastry was developed. The qualities of fat-reduced puff pastries were comparable to conventional full-fat (33 wt %) products. A sensory acceptance test revealed no significant differences in taste of fatness or ‘liking of mouthfeel’. Additionally, the fat-reduced puff pastry resulted in a significant (p < 0.05) positive correlation to ‘liking of flavor’ and overall acceptance by the assessors. PMID:28231095

Water resource use and management by the United States forest products industry.

PubMed

Wiegand, P S; Flinders, C A; Ice, G G; Malmberg, B J; Fisher, R P

2009-01-01

The connections between forest products operations and water resources in the United States is considered and, where possible, quantified. Manufacture of wood, pulp, and paper products and the influences of forest management and forest products manufacture on water quality are discussed. Most fresh water in the US originates in forested areas. Responsible harvesting strategies, best management practices, and forest re-growth combine to minimize or eliminate changes in water availability and degradation of water quality due to harvesting. Relative to alternative land uses and large-scale disturbance events, forested areas produce the highest quality of fresh water. Water inputs for the manufacture of forest products total about 5.8 billion m(3) per year, an amount equal about 0.4% of the surface and groundwater yield from timberland. Approximately 88% of water used in manufacturing is treated and returned directly to surface waters, about 11% is converted to water vapor and released during the manufacturing process, and 1% is imparted to products or solid residuals. Extensive study and continued monitoring of treated effluents suggest few or no concerns regarding the compatibility of current effluents with healthy aquatic systems.

Production of ergothioneine by Methylobacterium species

PubMed Central

Alamgir, Kabir M.; Masuda, Sachiko; Fujitani, Yoshiko; Fukuda, Fumio; Tani, Akio

2015-01-01

Metabolomic analysis revealed that Methylobacterium cells accumulate a large amount of ergothioneine (EGT), which is a sulfur-containing, non-proteinogenic, antioxidative amino acid derived from histidine. EGT biosynthesis and its role in methylotrophy and physiology for plant surface-symbiotic Methylobacterium species were investigated in this study. Almost all Methylobacterium type strains can synthesize EGT. We selected one of the most productive strains (M. aquaticum strain 22A isolated from a moss), and investigated the feasibility of fermentative EGT production through optimization of the culture condition. Methanol as a carbon source served as the best substrate for production. The productivity reached up to 1000 μg/100 ml culture (1200 μg/g wet weight cells, 6.3 mg/g dry weight) in 38 days. Next, we identified the genes (egtBD) responsible for EGT synthesis, and generated a deletion mutant defective in EGT production. Compared to the wild type, the mutant showed better growth on methanol and on the plant surface as well as severe susceptibility to heat treatment and irradiation of ultraviolet (UV) and sunlight. These results suggested that EGT is not involved in methylotrophy, but is involved in their phyllospheric lifestyle fitness of the genus in natural conditions. PMID:26579093

Production of ergothioneine by Methylobacterium species.

PubMed

Alamgir, Kabir M; Masuda, Sachiko; Fujitani, Yoshiko; Fukuda, Fumio; Tani, Akio

2015-01-01

Metabolomic analysis revealed that Methylobacterium cells accumulate a large amount of ergothioneine (EGT), which is a sulfur-containing, non-proteinogenic, antioxidative amino acid derived from histidine. EGT biosynthesis and its role in methylotrophy and physiology for plant surface-symbiotic Methylobacterium species were investigated in this study. Almost all Methylobacterium type strains can synthesize EGT. We selected one of the most productive strains (M. aquaticum strain 22A isolated from a moss), and investigated the feasibility of fermentative EGT production through optimization of the culture condition. Methanol as a carbon source served as the best substrate for production. The productivity reached up to 1000 μg/100 ml culture (1200 μg/g wet weight cells, 6.3 mg/g dry weight) in 38 days. Next, we identified the genes (egtBD) responsible for EGT synthesis, and generated a deletion mutant defective in EGT production. Compared to the wild type, the mutant showed better growth on methanol and on the plant surface as well as severe susceptibility to heat treatment and irradiation of ultraviolet (UV) and sunlight. These results suggested that EGT is not involved in methylotrophy, but is involved in their phyllospheric lifestyle fitness of the genus in natural conditions.

Land surface phenological responses to land use and climate variation in a changing Central Asia

NASA Astrophysics Data System (ADS)

Kariyeva, Jahan

During the last few decades Central Asia has experienced widespread changes in land cover and land use following the socio-economic and institutional transformations of the region catalyzed by the USSR collapse in 1991. The decade-long drought events and steadily increasing temperature regimes in the region came on top of these institutional transformations, affecting the long term and landscape scale vegetation responses. This research is based on the need to better understand the potential ecological and policy implications of climate variation and land use practices in the contexts of landscape-scale changes dynamics and variability patterns of land surface phenology responses in Central Asia. The land surface phenology responses -- the spatio-temporal dynamics of terrestrial vegetation derived from the remotely sensed data -- provide measurements linked to the timing of vegetation growth cycles (e.g., start of growing season) and total vegetation productivity over the growing season, which are used as a proxy for the assessment of effects of variations in environmental settings. Local and regional scale assessment of the before and after the USSR collapse vegetation response patterns in the natural and agricultural systems of the Central Asian drylands was conducted to characterize newly emerging links (since 1991) between coupled human and natural systems, e.g., socio-economic and policy drivers of altered land and water use and distribution patterns. Spatio-temporal patterns of bioclimatic responses were examined to determine how phenology is associated with temperature and precipitation in different land use types, including rainfed and irrigated agricultural types. Phenological models were developed to examine relationship between environmental drivers and effect of their altitudinal and latitudinal gradients on the broad-scale vegetation response patterns in non-cropland ecosystems of the desert, steppe, and mountainous regional landscapes of Central Asia. The study results demonstrated that the satellite derived measurements of temporal cycles of vegetation greenness and productivity data was a valuable bioclimatic integrator of climatic and land use variation in Central Asia. The synthesis of broad-scale phenological changes in Central Asia showed that linkages of natural and human systems vary across space and time comprising complex and tightly integrated patterns and processes that are not evident when studied separately.

EARLY WARNING IN DRINKING WATER INTAKE PROTECTION: CORRELATING CHEMICAL DATA AND BIOLOGICAL WARNING SYSTEMS

EPA Science Inventory

The WRK Water Works is responsible for the abstraction and partial purifcation of surface water for the drinking water production of some 2m people in the Netherlands. Two water winning stations, one at a side canal of the Rhine, the other at IJsselmeer lake provide an annual tot...

p-Nitrophenol and glutathione response in medaka (Oryzias latipes)exposed to MX, a drinking water carcinogen

EPA Science Inventory

When chlorine is introduced into public drinking water for disinfection, it can react with organic compounds in surface waters to form toxic by-products such as 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX). We investigated the effect of exposure to MX on cytochrome ...

P-NITROPHENOL AND GLUTATHIONE RESPONSE IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO MX, A DRINKING WATER CARCINOGEN.

EPA Science Inventory

When chlorine is introduced into public drinking water for disinfection, it can react with organic compounds in surface waters to form toxic by-products such as 3-chloro-4- (dichloromethyl)-5-hydroxy-2[5H]-furanone (MX). We investigated the effect of exposure to MX on cytochr...

Soil carbon changes: comparing flux monitoring and mass balance in a box lysimeter experiment.

Treesearch

S.M. Nay; B.T. Bormann

2000-01-01

Direct measures of soil-surface respiration are needed to evaluate belowground biological processes, forest productivity, and ecosystem responses to global change. Although infra-red gas analyzer {IRGA) methods track reference CO2 flows in lab studies, questions remain for extrapolating IRGA methods to field conditions. We constructed 10 box...

The interconnection of wet and dry deposition and the response of deposition to incorporation of new process understanding in regional models.

EPA Science Inventory

Process level improvements in the CMAQ system have been made to WRF meteorology, lightning NO production, national ammonia emission profiles, and CMAQ ammonia air-surface exchange. An incremental study was conducted to quantify the impact of individual and combined changes on mo...

Fault Lines in American Culture: The Case for Civic Debate

ERIC Educational Resources Information Center

Hartoonian, H. Michael; Van Scotter, Richard D.

2012-01-01

The social landscape of the United States can be mapped by using a series of cultural fault lines. This topography portrays conditions that descriptions of the surface fail to illuminate. Many of these schisms are the by-product of ideological positions that diminish personal responsibility and thoughtful civic discourse. If left unattended, these…

Overview of expression of hepatitis B surface antigen in transgenic plants.

PubMed

Guan, Zheng-jun; Guo, Bin; Huo, Yan-lin; Guan, Zheng-ping; Wei, Ya-hui

2010-10-28

Hepatitis B virus (HBV), a pathogen for chronic liver infection, afflicts more than 350 million people world-wide. The effective way to control the virus is to take HBV vaccine. Hepatitis B surface antigen (HBsAg) is an effective protective antigen suitable for vaccine development. At present, "edible" vaccine based on transgenic plants is one of the most promising directions in novel types of vaccines. HBsAg production from transgenic plants has been carried out, and the transgenic plant expression systems have developed from model plants (such as tobacco, potato and tomato) to other various plant platforms. Crude or purified extracts of transformed plants have been found to conduct immunological responses and clinical trials for hepatitis B, which gave the researches of plant-based HBsAg production a big boost. The aim of this review was to summarize the recent data about plant-based HBsAg development including molecular biology of HBsAg gene, selection of expression vector, the expression of HBsAg gene in plants, as well as corresponding immunological responses in animal models or human. Copyright © 2010 Elsevier Ltd. All rights reserved.

Optimization of CMCase production from sorghum straw by Aspergillus terreus SUK-1 under solid substrate fermentation using response surface methodology

NASA Astrophysics Data System (ADS)

Tibin, El Mubarak Musa; Al-Shorgani, Najeeb Kaid Naseer; Abuelhassan, Nawal Noureldaim; Hamid, Aidil Abdul; Kalil, Mohd Sahaid; Yusoff, Wan Mohtar Wan

2013-11-01

The cellulase production using sorghum straw as substrate by fungal culture of Aspergillus terreus SUK-1 was investigated in solid substrate fermentation (SSF). The optimum CMCase was achieved by testing most effective fermentation parameters which were: incubation temperature, pH and moisture content using Response Surface Methodology (RSM) based on Central Composite Design (CCD). The carboxymethyl cellulase activity (CMCase) was measured as the defining factor. The results were analysed by analysis of variance (ANOVA) and the regression quadratic model was obtained. The model was found to be significant (p<0.05) and the effect of temperature (25-40°C) and pH (4-7) was found to be not significant on CMCase activity whereas the moisture content was significant in the SSF conditions employed. The high yield of predicted CMCase activity (0.2 U/ml) was obtained under the optimized conditions (temperature 40 □C, pH 5.4 and moisture content of 80%). The model was validated by applying the optimized conditions and it was found that the model was valid.

Enhanced solid-state citric acid bio-production using apple pomace waste through surface response methodology.

PubMed

Dhillon, G S; Brar, S K; Verma, M; Tyagi, R D

2011-04-01

  To evaluate the potential of apple pomace (AP) supplemented with rice husk for hyper citric acid production through solid-state fermentation by Aspergillus niger NRRL-567. Optimization of two key parameters, such as moisture content and inducer (ethanol and methanol) concentration was carried out by response surface methodology.   In this study, the effect of two crucial process parameters for solid-state citric acid fermentation by A. niger using AP waste supplemented with rice husk were thoroughly investigated in Erlenmeyer flasks through response surface methodology. Moisture and methanol had significant positive effect on citric acid production by A. niger grown on AP (P < 0·05). Higher values of citric acid on AP by A. niger (342·41gkg(-1) and 248·42gkg(-1) dry substrate) were obtained with 75% (v/w) moisture along with two inducers [3% (v/w) methanol and 3% (v/w) ethanol] with fermentation efficiency of 93·90% and 66·42%, respectively depending upon the total carbon utilized after 144h of incubation period. With the same optimized parameters, conventional tray fermentation was conducted. The citric acid concentration of 187·96gkg(-1) dry substrate with 3% (v/w) ethanol and 303·34gkg(-1) dry substrate with 3% (v/w) methanol were achieved representing fermentation efficiency of 50·80% and 82·89% in tray fermentation depending upon carbon utilization after 120h of incubation period.   Apple pomace proved to be the promising substrate for the hyper production of citric acid through solid-state tray fermentation, which is an economical technique and does not require any sophisticated instrumentation.   The study established that the utilization of agro-industrial wastes have positive repercussions on the economy and will help to meet the increasing demands of citric acid and moreover will help to alleviate the environmental problems resulting from the disposal of agro-industrial wastes. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Dielectric Response at THz Frequencies of Fe Water Complexes and Their Interaction with O3 Calculated by Density Functional Theory

DTIC Science & Technology

2012-10-24

geometric arrangement of the atoms in a chemical system , at the maximal peak of the energy surface separating reactants from products . In the...Sonnenberg, M. Hada, M. Ehara, K. Toyota , R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda , O. Kitao, H. Nakai, T. Vreven, J. A. Montgomery... using DFT. The calculation of ground state resonance structure is for the construction of parameterized dielectric response functions for excitation

Optimization of Polygalacturonase Production from a Newly Isolated Thalassospira frigidphilosprofundus to Use in Pectin Hydrolysis: Statistical Approach

PubMed Central

Rekha, V. P. B.; Ghosh, Mrinmoy; Adapa, Vijayanand; Oh, Sung-Jong; Pulicherla, K. K.; Sambasiva Rao, K. R. S.

2013-01-01

The present study deals with the production of cold active polygalacturonase (PGase) by submerged fermentation using Thalassospira frigidphilosprofundus, a novel species isolated from deep waters of Bay of Bengal. Nonlinear models were applied to optimize the medium components for enhanced production of PGase. Taguchi orthogonal array design was adopted to evaluate the factors influencing the yield of PGase, followed by the central composite design (CCD) of response surface methodology (RSM) to identify the optimum concentrations of the key factors responsible for PGase production. Data obtained from the above mentioned statistical experimental design was used for final optimization study by linking the artificial neural network and genetic algorithm (ANN-GA). Using ANN-GA hybrid model, the maximum PGase activity (32.54 U/mL) was achieved at the optimized concentrations of medium components. In a comparison between the optimal output of RSM and ANN-GA hybrid, the latter favored the production of PGase. In addition, the study also focused on the determination of factors responsible for pectin hydrolysis by crude pectinase extracted from T. frigidphilosprofundus through the central composite design. Results indicated 80% degradation of pectin in banana fiber at 20°C in 120 min, suggesting the scope of cold active PGase usage in the treatment of raw banana fibers. PMID:24455722

Optimization of polygalacturonase production from a newly isolated Thalassospira frigidphilosprofundus to use in pectin hydrolysis: statistical approach.

PubMed

Rekha, V P B; Ghosh, Mrinmoy; Adapa, Vijayanand; Oh, Sung-Jong; Pulicherla, K K; Sambasiva Rao, K R S

2013-01-01

The present study deals with the production of cold active polygalacturonase (PGase) by submerged fermentation using Thalassospira frigidphilosprofundus, a novel species isolated from deep waters of Bay of Bengal. Nonlinear models were applied to optimize the medium components for enhanced production of PGase. Taguchi orthogonal array design was adopted to evaluate the factors influencing the yield of PGase, followed by the central composite design (CCD) of response surface methodology (RSM) to identify the optimum concentrations of the key factors responsible for PGase production. Data obtained from the above mentioned statistical experimental design was used for final optimization study by linking the artificial neural network and genetic algorithm (ANN-GA). Using ANN-GA hybrid model, the maximum PGase activity (32.54 U/mL) was achieved at the optimized concentrations of medium components. In a comparison between the optimal output of RSM and ANN-GA hybrid, the latter favored the production of PGase. In addition, the study also focused on the determination of factors responsible for pectin hydrolysis by crude pectinase extracted from T. frigidphilosprofundus through the central composite design. Results indicated 80% degradation of pectin in banana fiber at 20 °C in 120 min, suggesting the scope of cold active PGase usage in the treatment of raw banana fibers.

Statistical optimization for improved production of cyclosporin a in solid-state fermentation.

PubMed

Survase, Shrikant A; Annapure, Uday S; Singhal, Rekha S

2009-11-01

This work evaluates the effect of different amino acids on production of CyA production in solid-state fermentation that was previously optimized for different fermentation parameters by one-factor-at-a-time for the maximum production of CyA by Tolypocladium inflatum MTCC 557. Based on the Plackett-Burman design, glycerol, ammonium sulfate, FeCl3, and inoculum size were selected for further optimization by response surface methodology (RSM). After identifying effective nutrients, RSM was used to develop mathematical model equations, study responses, and establish the optimum concentrations of the key nutrients for higher CyA production. It was observed that supplementation of medium containing (% w/w) glycerol, 1.53; ammonium sulfate, 0.95; FeCl3, 0.18; and inoculum size 6.4 ml/5g yielded a maximum of 7,106 mg/kg as compared with 6,480 mg CyA/kg substrate using one factor at a time. In the second step, the effect of amino acids on the production of CyA was studied. Addition of L-valine and L-leucine in combination after 20 h of fermentation resulted in maximum production of 8,166 mg/kg.

Engineering chimeric human and mouse major histocompatibility complex (MHC) class I tetramers for the production of T-cell receptor (TCR) mimic antibodies

PubMed Central

Bentley, Carol; Yates, Jenna; Salimi, Maryam; Greig, Jenny; Wiblin, Sarah; Hassanali, Tasneem; Banham, Alison H.

2017-01-01

Therapeutic monoclonal antibodies targeting cell surface or secreted antigens are among the most effective classes of novel immunotherapies. However, the majority of human proteins and established cancer biomarkers are intracellular. Peptides derived from these intracellular proteins are presented on the cell surface by major histocompatibility complex class I (MHC-I) and can be targeted by a novel class of T-cell receptor mimic (TCRm) antibodies that recognise similar epitopes to T-cell receptors. Humoural immune responses to MHC-I tetramers rarely generate TCRm antibodies and many antibodies recognise the α3 domain of MHC-I and β2 microglobulin (β2m) that are not directly involved in presenting the target peptide. Here we describe the production of functional chimeric human-murine HLA-A2-H2Dd tetramers and modifications that increase their bacterial expression and refolding efficiency. These chimeric tetramers were successfully used to generate TCRm antibodies against two epitopes derived from wild type tumour suppressor p53 (RMPEAAPPV and GLAPPQHLIRV) that have been used in vaccination studies. Immunisation with chimeric tetramers yielded no antibodies recognising the human α3 domain and β2m and generated TCRm antibodies capable of specifically recognising the target peptide/MHC-I complex in fully human tetramers and on the cell surface of peptide pulsed T2 cells. Chimeric tetramers represent novel immunogens for TCRm antibody production and may also improve the yield of tetramers for groups using these reagents to monitor CD8 T-cell immune responses in HLA-A2 transgenic mouse models of immunotherapy. PMID:28448627

Characterization of biosurfactants produced by Lactobacillus spp. and their activity against oral streptococci biofilm.

PubMed

Ciandrini, Eleonora; Campana, Raffaella; Casettari, Luca; Perinelli, Diego R; Fagioli, Laura; Manti, Anita; Palmieri, Giovanni Filippo; Papa, Stefano; Baffone, Wally

2016-08-01

Lactic acid bacteria (LAB) can interfere with pathogens through different mechanisms; one is the production of biosurfactants, a group of surface-active molecules, which inhibit the growth of potential pathogens. In the present study, biosurfactants produced by Lactobacillus reuteri DSM 17938, Lactobacillus acidophilus DDS-1, Lactobacillus rhamnosus ATCC 53103, and Lactobacillus paracasei B21060 were dialyzed (1 and 6 kDa) and characterized in term of reduction of surface tension and emulsifying activity. Then, aliquots of the different dialyzed biosurfactants were added to Streptococcus mutans ATCC 25175 and Streptococcus oralis ATCC 9811 in the culture medium during the formation of biofilm on titanium surface and the efficacy was determined by agar plate count, biomass analyses, and flow cytometry. Dialyzed biosurfactants showed abilities to reduce surface tension and to emulsifying paraffin oil. Moreover, they significantly inhibited the adhesion and biofilm formation on titanium surface of S. mutans and S. oralis in a dose-dependent way, as demonstrated by the remarkable decrease of cfu/ml values and biomass production. The antimicrobial properties observed for dialyzed biosurfactants produced by the tested lactobacilli opens future prospects for their use against microorganisms responsible of oral diseases.

Fish like it Hot? The response of ichthyolith accumulation to changing climates of the Paleogene

NASA Astrophysics Data System (ADS)

Sibert, E. C.; Zill, M. E.; Bryant, R. M.; Graves, L. G.; Norris, R. D.

2014-12-01

It has been hypothesized that the production of fish in the water column is related to the amount of primary production in the surface waters. Most future Earth scenarios suggest that as the climate warms, increased surface ocean stratification will decrease nutrient availability and therefore net primary productivity and fish production. Here we calculate accumulation rates of ichthyoliths (microfossil fish teeth and shark dermal scales) throughout the Paleogene and find that ichthyolith accumulation is inversely related to hypothesized changes in primary productivity, but is positively related to ocean temperature. At DSDP Site 596 in the South Pacific, and ODP Site 1258 from the equatorial Atlantic, accumulation of fish fossils increase 6-10 fold from the relatively cool Paleocene into the warm Early Eocene Climate Optimum. In contrast, cooling and increased biosilica deposition at the Eocene/Oligocene (E/O) Boundary suggests that the marine ecosystem switched to a highly productive diatom-dominated ocean, which should favor short, efficient food chains and increased fish production. However, we find that at both Pacific DSDP Site 596 and Atlantic DSDP Site 522, fish accumulation drops by about 50% across the E/O. Indeed, this relation between ichthyolith accumulation and δ18O-estimated paleotemperature is also seen in the Oligocene, at North Pacific ODP Site 886, where warming in the middle Oligocene is mirrored by an increase in ichthyolith accumulation. It appears that ichthyolith accumulation rate may not be purely an effect of total primary production in the water column but rather, may reflect a fundamental response in fish physiology or ecosystem efficiency to warmer water. It has been documented that respiration is faster and more efficient in warm waters, and this may help generate more efficient food web links that compensate for any decrease in primary productivity caused by global warming. Indeed, it appears that fish seem to thrive as the temperature goes up.

Lysosomal-associated Transmembrane Protein 4B (LAPTM4B) Decreases Transforming Growth Factor β1 (TGF-β1) Production in Human Regulatory T Cells.

PubMed

Huygens, Caroline; Liénart, Stéphanie; Dedobbeleer, Olivier; Stockis, Julie; Gauthy, Emilie; Coulie, Pierre G; Lucas, Sophie

2015-08-14

Production of active TGF-β1 is one mechanism by which human regulatory T cells (Tregs) suppress immune responses. This production is regulated by glycoprotein A repetitions predominant (GARP), a transmembrane protein present on stimulated Tregs but not on other T lymphocytes (Th and CTLs). GARP forms disulfide bonds with proTGF-β1, favors its cleavage into latent inactive TGF-β1, induces the secretion and surface presentation of GARP·latent TGF-β1 complexes, and is required for activation of the cytokine in Tregs. We explored whether additional Treg-specific protein(s) associated with GARP·TGF-β1 complexes regulate TGF-β1 production in Tregs. We searched for such proteins by yeast two-hybrid assay, using GARP as a bait to screen a human Treg cDNA library. We identified lysosomal-associated transmembrane protein 4B (LAPTM4B), which interacts with GARP in mammalian cells and is expressed at higher levels in Tregs than in Th cells. LAPTM4B decreases cleavage of proTGF-β1, secretion of soluble latent TGF-β1, and surface presentation of GARP·TGF-β1 complexes by Tregs but does not contribute to TGF-β1 activation. Therefore, LAPTM4B binds to GARP and is a negative regulator of TGF-β1 production in human Tregs. It may play a role in the control of immune responses by decreasing Treg immunosuppression. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Common bean varieties demonstrate differential physiological and metabolic responses to the pathogenic fungus Sclerotinia sclerotiorum.

PubMed

Robison, Faith M; Turner, Marie F; Jahn, Courtney E; Schwartz, Howard F; Prenni, Jessica E; Brick, Mark A; Heuberger, Adam L

2018-02-24

Plant physiology and metabolism are important components of a plant response to microbial pathogens. Physiological resistance of common bean (Phaseolus vulgaris L.) to the fungal pathogen Sclerotinia sclerotiorum has been established, but the mechanisms of resistance are largely unknown. Here, the physiological and metabolic responses of bean varieties that differ in physiological resistance to S. sclerotiorum are investigated. Upon infection, the resistant bean variety A195 had a unique physiological response that included reduced photosynthesis and maintaining a higher leaf surface pH during infection. Leaf metabolomics was performed on healthy tissue adjacent to the necrotic lesion at 16, 24, and 48 hr post inoculation, and 144 metabolites were detected that varied between A195 and Sacramento following infection. The metabolites that varied in leaves included amines/amino acids, organic acids, phytoalexins, and ureides. The metabolic pathways associated with resistance included amine metabolism, uriede-based nitrogen remobilization, antioxidant production, and bean-specific phytoalexin production. A second experiment was conducted in stems of 13 bean genotypes with varying resistance. Stem resistance was associated with phytoalexin production, but unlike leaf metabolism, lipid changes were associated with susceptibility. Taken together, the data supports a multifaceted, physiometabolic response of common bean to S. sclerotiorum that mediates resistance. © 2018 John Wiley & Sons Ltd.

Method for detecting toxic gases

DOEpatents

Stetter, Joseph R.; Zaromb, Solomon; Findlay, Jr., Melvin W.

1991-01-01

A method capable of detecting low concentrations of a pollutant or other component in air or other gas, utilizing a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component, and an electrochemical sensor responsive to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor.

Ethanol production from sweet sorghum bagasse through process optimization using response surface methodology.

PubMed

Lavudi, Saida; Oberoi, Harinder Singh; Mangamoori, Lakshmi Narasu

2017-08-01

In this study, comparative evaluation of acid- and alkali pretreatment of sweet sorghum bagasse (SSB) was carried out for sugar production after enzymatic hydrolysis. Results indicated that enzymatic hydrolysis of alkali-pretreated SSB resulted in higher production of glucose, xylose and arabinose, compared to the other alkali concentrations and also acid-pretreated biomass. Response Surface Methodology (RSM) was, therefore, used to optimize parameters, such as alkali concentration, temperature and time of pretreatment prior to enzymatic hydrolysis to maximize the production of sugars. The independent variables used during RSM included alkali concentration (1.5-4%), pretreatment temperature (125-140 °C) and pretreatment time (10-30 min) were investigated. Process optimization resulted in glucose and xylose concentration of 57.24 and 10.14 g/L, respectively. Subsequently, second stage optimization was conducted using RSM for optimizing parameters for enzymatic hydrolysis, which included substrate concentration (10-15%), incubation time (24-60 h), incubation temperature (40-60 °C) and Celluclast concentration (10-20 IU/g-dwt). Substrate concentration 15%, (w/v) temperature of 60 °C, Celluclast concentration of 20 IU/g-dwt and incubation time of 58 h led to a glucose concentration of 68.58 g/l. Finally, simultaneous saccharification fermentation (SSF) as well as separated hydrolysis and fermentation (SHF) was evaluated using Pichia kudriavzevii HOP-1 for production of ethanol. Significant difference in ethanol concentration was not found using either SSF or SHF; however, ethanol productivity was higher in case of SSF, compared to SHF. This study has established a platform for conducting scale-up studies using the optimized process parameters.

Effects of Exposure to Ozone on the Ocular Surface in an Experimental Model of Allergic Conjunctivitis

PubMed Central

Lee, Hun; Kim, Eung Kweon; Kim, Hee Young; Kim, Tae-im

2017-01-01

Based on previous findings that ozone can induce an inflammatory response in the ocular surface of an animal model and in cultured human conjunctival epithelial cells, we investigated whether exposure to ozone exacerbates symptoms of allergic conjunctivitis. We evaluated the effects of exposure to ozone on conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, production of inflammatory cytokines in tears, and aqueous tear production in a mouse model of allergic conjunctivitis. To validate our in vivo results, we used interleukin (IL)-1α-pretreated conjunctival epithelial cells as an in vitro substitute for the mouse model. We evaluated whether exposure to ozone increased the inflammatory response and altered oxidative status and mitochondrial function in IL-1α-pretreated conjunctival epithelial cells. In the in vivo study, ozone induced increases in conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, and production of inflammatory cytokines, accompanied by a decrease in tear volume. In the in vitro study, exposure to ozone led to additional increases in IL-6 and tumor necrosis factor-α mRNA levels, which were already induced by treatment with IL-1α. Ozone did not induce any changes in cell viability. Pretreatment with IL-1α increased the expression of manganese superoxide dismutase, and exposure to ozone led to additional increments in the expression of this antioxidant enzyme. Ozone did not induce any changes in mitochondrial activity or expression of mitochondrial enzymes and proteins related to mitochondrial function, with the exception of phosphor-mammalian target of rapamycin. Treatment with butylated hydroxyanisole, a free radical scavenger, attenuated the ozone-induced increases in IL-6 expression in IL-1α-pretreated conjunctival epithelial cells. Therefore, we conclude that exposure to ozone exacerbates the detrimental effects on the integrity of the ocular surface caused by conjunctival allergic reactions, and further increases the inflammatory response in IL-1α-pretreated conjunctival epithelial cells. PMID:28046113

Third generation snacks manufactured from orange by-products: physicochemical and nutritional characterization.

PubMed

Tovar-Jiménez, Xochitl; Caro-Corrales, José; Gómez-Aldapa, Carlos A; Zazueta-Morales, José; Limón-Valenzuela, Víctor; Castro-Rosas, Javier; Hernández-Ávila, Juan; Aguilar-Palazuelos, Ernesto

2015-10-01

A mixture of orange vesicle flour, commercial nixtamalized corn flour and potato starch was extruded using a Brabender Laboratory single screw extruder (2:1 L/D). The resulting pellets were expanded by microwaves. Expansion index, bulk density, penetration force, carotenoid content, and dietary fiber were measured for this third-generation snack and optimum production conditions were estimated. Response surface methodology was applied using a central composite rotatable experimental design to evaluate the effect of moisture content and extrusion temperature. Temperature mainly affected the expansion index, bulk density and penetration force, while carotenoids content was affected by moisture content. Surface overlap was used to identify optimum processing conditions: temperature: 128-130 °C; moisture content: 22-24 %. Insoluble dietary fiber decreased and soluble dietary fiber increased after extrusion.

Policing the intestinal epithelial barrier: Innate immune functions of intraepithelial lymphocytes.

PubMed

Hu, Madeleine D; Jia, Luo; Edelblum, Karen L

2018-03-01

This review will explore the contribution of IELs to mucosal innate immunity and highlight the similarities in IEL functional responses to bacteria, viruses and protozoan parasite invasion. IELs rapidly respond to microbial invasion by activating host defense responses, including the production of mucus and antimicrobial peptides to prevent microbes from reaching the epithelial surface. During active infection, IELs promote epithelial cytolysis, cytokine and chemokine production to limit pathogen invasion, replication and dissemination. Commensal-induced priming of IEL effector function or continuous surveillance of the epithelium may be important contributing factors to the rapidity of response. Impaired microbial recognition, dysregulated innate immune signaling or microbial dysbiosis may limit the protective function of IELs and increase susceptibility to disease. Further understanding of the mechanisms regulating IEL surveillance and sentinel function may provide insight into the development of more effective targeted therapies designed to reinforce the mucosal barrier.

Preliminary study of the Suomi NPP VIIRS detector-level spectral response function effects for the long-wave infrared bands M15 and M16

NASA Astrophysics Data System (ADS)

Padula, Francis; Cao, Changyong

2014-09-01

The Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS) Sea Surface Temperature (SST) Environmental Data Record (EDR) team observed an anomalous striping pattern in the SST data. To assess possible causes due to the detector-level Spectral Response Functions (SRFs), a study was conducted to compare the radiometric response of the detector-level and operation band averaged SRFs of VIIRS bands M15 & M16 using simulated blackbody radiance data and clear-sky ocean radiances under different atmospheric conditions. It was concluded that the SST product is likely impacted by small differences in detector-level SRFs, and that if users require optimal system performance detector-level processing is recommended. Future work will investigate potential SDR product improvements through detector-level processing in support of the generation of Suomi NPP VIIRS climate quality SDRs.

The use of Design of Experiments and Response Surface Methodology to optimize biomass and lipid production by the oleaginous marine green alga, Nannochloropsis gaditana in response to light intensity, inoculum size and CO2.

PubMed

Hallenbeck, Patrick C; Grogger, Melanie; Mraz, Megan; Veverka, Donald

2015-05-01

Biodiesel produced from microalgal lipids is being considered as a potential source of renewable energy. However, a number of hurdles will have to be overcome if such a process is to become practical. One important factor is the volumetric production of biomass and lipid that can be achieved. The marine alga Nannochloropsis gaditana is under study since it is known to be highly oleaginous and has a number of other attractive properties. Factors that might be important in biomass and lipid production by this alga are light intensity, inoculum size and CO2. Here we have carried out for the first time a RSM-DOE study of the influence of these important culture variables and define conditions that maximize biomass production, lipid content (BODIPY® fluorescence) and total lipid production. Moreover, flow cytometry allowed the examination on a cellular level of changes that occur in cellular populations as they age and accumulate lipids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Index for characterizing post-fire soil environments in temperate coniferous forests

USGS Publications Warehouse

Jain, Theresa B.; Pilliod, David S.; Graham, Russell T.; Lentile, Leigh B.; Sandquist, Jonathan E.

2012-01-01

Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available science and ecological thresholds. Using over 50 literature sources, we identified a minimum of five broad categories of post-fire outcomes: (a) unburned, (b) abundant surface organic matter ( > 85% surface organic matter), (c) moderate amount of surface organic matter ( ≥ 40 through 85%), (d) small amounts of surface organic matter ( < 40%), and (e) absence of surface organic matter (no organic matter left). We then subdivided each broad category on the basis of post-fire mineral soil colors providing a more fine-tuned post-fire soil index. We related each PFI category to characteristics such as soil temperature and duration of heating during fire, and physical, chemical, and biological responses. Classifying or describing post-fire soil conditions consistently will improve interpretations of fire effects research and facilitate communication of potential responses or outcomes (e.g., erosion potential) from fires of varying severities.

Beyond greening and browning: the need for an integrated understanding of Arctic change

NASA Astrophysics Data System (ADS)

Gamon, J. A.; Huemmrich, K. F.; Hmimina, G.; Yu, R.

2017-12-01

Satellite records and field observations povide contradictory evidence for "greening" or "browning" of Arctic tundra. Large-scale observations of apparent greening have been based on satellite vegetation indices (e.g NDVI). However, a clear interpretation of these trends are confounded by changing snow cover and surface hydrology, both of which influence NDVI and are known to be changing independently of any direct vegetation response. Field studies have demonstrated greening in some areas, but not others, and have also documented changing permafrost depth, surface hydrology and snow cover. Together, these confounding factors can explain some of the contradictory evidence based regarding greening and browning. Given the multiple influences on Arctic NDVI, simple conclusions regarding greening and browning from satellite data alone can be incorrect; when these confounding factors are taken into account, some areas that show apparent greening in the satellite record appear to be undergoing productivity declines due to surface drying. These contradictory interpretations have profound implications for our understanding of changing surface energy balance, biogeochemistry, and surface-atmosphere feedbacks. To better address Arctic ecosystem responses to a changing climate, an integrated, multi-scale, multivariate approach that considers hydrology, permafrost, snow cover and vegetation is needed.

Optimization of Extraction Conditions for Phenolic Acids from the Leaves of Melissa officinalis L. Using Response Surface Methodology

PubMed Central

Yoo, Guijae; Lee, Il Kyun; Park, Seonju; Kim, Nanyoung; Park, Jun Hyung; Kim, Seung Hyun

2018-01-01

Background: Melissa officinalis L. is a well-known medicinal plant from the family Lamiaceae, which is distributed throughout Eastern Mediterranean region and Western Asia. Objective: In this study, response surface methodology (RSM) was utilized to optimize the extraction conditions for bioactive compounds from the leaves of M. officinalis L. Materials and Methods: A Box–Behnken design (BBD) was utilized to evaluate the effects of three independent variables, namely extraction temperature (°C), methanol concentration (%), and solvent-to-material ratio (mL/g) on the responses of the contents of caffeic acid and rosmarinic acid. Results: Regression analysis showed a good fit of the experimental data. The optimal condition was obtained at extraction temperature 80.53°C, methanol concentration 29.89%, and solvent-to-material ratio 30 mL/g. Conclusion: These results indicate the suitability of the model employed and the successful application of RSM in optimizing the extraction conditions. This study may be useful for standardizing production quality, including improving the efficiency of large-scale extraction systems. SUMMARY The optimum conditions for the extraction of major phenolic acids from the leaves of Melissa officinalis L. were determined using response surface methodologyBox–Behnken design was utilized to evaluate the effects of three independent variablesQuadratic polynomial model provided a satisfactory description of the experimental dataThe optimized condition for simultaneous maximum contents of caffeic acid and rosmarinic acid was determined. Abbreviations used: RSM: Response surface methodology, BBD: Box–Behnken design, CA: Caffeic acid, RA: Rosmarinic acid, HPLC: High-performance liquid chromatography. PMID:29720824

Optimization of Geothermal Well Placement under Geological Uncertainty

NASA Astrophysics Data System (ADS)

Schulte, Daniel O.; Arnold, Dan; Demyanov, Vasily; Sass, Ingo; Geiger, Sebastian

2017-04-01

Well placement optimization is critical to commercial success of geothermal projects. However, uncertainties of geological parameters prohibit optimization based on a single scenario of the subsurface, particularly when few expensive wells are to be drilled. The optimization of borehole locations is usually based on numerical reservoir models to predict reservoir performance and entails the choice of objectives to optimize (total enthalpy, minimum enthalpy rate, production temperature) and the development options to adjust (well location, pump rate, difference in production and injection temperature). Optimization traditionally requires trying different development options on a single geological realization yet there are many possible different interpretations possible. Therefore, we aim to optimize across a range of representative geological models to account for geological uncertainty in geothermal optimization. We present an approach that uses a response surface methodology based on a large number of geological realizations selected by experimental design to optimize the placement of geothermal wells in a realistic field example. A large number of geological scenarios and design options were simulated and the response surfaces were constructed using polynomial proxy models, which consider both geological uncertainties and design parameters. The polynomial proxies were validated against additional simulation runs and shown to provide an adequate representation of the model response for the cases tested. The resulting proxy models allow for the identification of the optimal borehole locations given the mean response of the geological scenarios from the proxy (i.e. maximizing or minimizing the mean response). The approach is demonstrated on the realistic Watt field example by optimizing the borehole locations to maximize the mean heat extraction from the reservoir under geological uncertainty. The training simulations are based on a comprehensive semi-synthetic data set of a hierarchical benchmark case study for a hydrocarbon reservoir, which specifically considers the interpretational uncertainty in the modeling work flow. The optimal choice of boreholes prolongs the time to cold water breakthrough and allows for higher pump rates and increased water production temperatures.

Cost-effective approach to ethanol production and optimization by response surface methodology.

PubMed

Uncu, Oya Nihan; Cekmecelioglu, Deniz

2011-04-01

Food wastes disposed from residential and industrial kitchens have gained attention as a substrate in microbial fermentations to reduce product costs. In this study, the potential of simultaneously hydrolyzing and subsequently fermenting the mixed carbohydrate components of kitchen wastes were assessed and the effects of solid load, inoculum volume of baker's yeast, and fermentation time on ethanol production were evaluated by response surface methodology (RSM). The enzymatic hydrolysis process was complete within 6h. Fermentation experiments were conducted at pH 4.5, a temperature of 30°C, and agitated at 150 rpm without adding the traditional fermentation nutrients. The statistical analysis of the model developed by RSM suggested that linear effects of solid load, inoculum volume, and fermentation time and the quadratic effects of inoculum volume and fermentation time were significant (P<0.05). The verification experiments indicated that the developed model could be successfully used to predict ethanol concentration at >90% accuracy. An optimum ethanol concentration of 32.2g/l giving a yield of 0.40g/g, comparable to yields reported to date, was suggested by the model with 20% solid load, 8.9% inoculum volume, and 58.8h of fermentation. The results indicated that the production costs can be lowered to a large extent by using kitchen wastes having multiple carbohydrate components and eliminating the use of traditional fermentation nutrients from the recipe. Copyright © 2010 Elsevier Ltd. All rights reserved.

Optimization of Sugar Replacement with Date Syrup in Prebiotic Chocolate Milk Using Response Surface Methodology.

PubMed

Kazemalilou, Sahar; Alizadeh, Ainaz

2017-01-01

Chocolate milk is one of the most commonly used non-fermentative dairy products, which, due to high level of sucrose, could lead to diabetes and tooth decay among children. Therefore, it is important to replace sucrose with other types of sweeteners, especially, natural ones. In this research, response surface methodology (RSM) was used to optimize the ingredients formulation of prebiotic chocolate milk, date syrup as sweetener (4-10%w/w), inulin as prebiotic texturizer (0-0.5%w/w) and carrageenan as thickening agent (0-0.04%w/w) in the formulation of chocolate milk. The fitted models to predict the variables of selected responses such as pH, viscosity, total solid, sedimentation and overall acceptability of chocolate milk showed a high coefficient of determination. The independent effect of carrageenan was the most effective parameter which led to pH and sedimentation decrease but increased viscosity. Moreover, in most treatments, date syrup and inulin variables had significant effects which had a mutual impact. Optimization of the variables, based on the responses surface 3D plots showed that the sample containing 0.48% (w/w) of inulin, 0.04% (w/w) of carrageenan, and 10% of date syrup was selected as the optimum condition.

NASA Applied Sciences Disasters Program Support for the September 2017 Mexico Earthquakes

NASA Astrophysics Data System (ADS)

Glasscoe, M. T.; Kirschbaum, D.; Torres-Perez, J. L.; Yun, S. H.; Owen, S. E.; Hua, H.; Fielding, E. J.; Liang, C.; Bekaert, D. P.; Osmanoglu, B.; Amini, R.; Green, D. S.; Murray, J. J.; Stough, T.; Struve, J. C.; Seepersad, J.; Thompson, V.

2017-12-01

The 8 September M 8.1 Tehuantepec and 19 September M 7.1 Puebla earthquakes were among the largest earthquakes recorded in Mexico. These two events caused widespread damage, affecting several million people and causing numerous casualties. A team of event coordinators in the NASA Applied Sciences Program activated soon after these devastating earthquakes in order to support decision makers in Mexico, using NASA modeling and international remote sensing capabilities to generate decision support products to aid in response and recovery. The NASA Disasters Program promotes the use of Earth observations to improve the prediction of, preparation for, response to, and recovery from natural and technological disasters. For these two events, the Disasters Program worked with Mexico's space agency (Agencia Espacial Mexico, AEM) and the National Center for Prevention of Disasters (Centro Nacional de Prevención de Desastres, CENAPRED) to generate products to support response, decision-making, and recovery. Products were also provided to academic partners, technical institutions, and field responders to support response. In addition, the Program partnered with the US Geological Survey (USGS), Office of Foreign Disaster Assistance (OFDA), and other partners in order to provide information to federal and domestic agencies that were supporting event response. Leveraging the expertise of investigators at NASA Centers, products such as landslide susceptibility maps, precipitation models, and radar based damage assessments and surface deformation maps were generated and used by AEM, CENAPRED, and others during the event. These were used by AEM in collaboration with other government agencies in Mexico to make appropriate decisions for mapping damage, rescue and recovery, and informing the population regarding areas prone to potential risk. We will provide an overview of the response activities and data products generated in support of the earthquake response, partnerships with domestic and international partners, and preliminary feedback from end-user partners in Mexico during response efforts following these two earthquakes.

Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

PubMed Central

Boaretti, Carlo; Roso, Martina; Lorenzetti, Alessandra; Modesti, Michele

2015-01-01

In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate) and material (sulfonation degree) variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers. PMID:28793427

Monte Carlo Solution to Find Input Parameters in Systems Design Problems

NASA Astrophysics Data System (ADS)

Arsham, Hossein

2013-06-01

Most engineering system designs, such as product, process, and service design, involve a framework for arriving at a target value for a set of experiments. This paper considers a stochastic approximation algorithm for estimating the controllable input parameter within a desired accuracy, given a target value for the performance function. Two different problems, what-if and goal-seeking problems, are explained and defined in an auxiliary simulation model, which represents a local response surface model in terms of a polynomial. A method of constructing this polynomial by a single run simulation is explained. An algorithm is given to select the design parameter for the local response surface model. Finally, the mean time to failure (MTTF) of a reliability subsystem is computed and compared with its known analytical MTTF value for validation purposes.

Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology.

PubMed

Boaretti, Carlo; Roso, Martina; Lorenzetti, Alessandra; Modesti, Michele

2015-07-07

In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate) and material (sulfonation degree) variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers.

[Construction of a multiple-scale implant surface with super-hydrophilicity].

PubMed

Luo, Qiao-jie; Li, Xiao-dong; Huang, Ying; Zhao, Shi-fang

2012-05-01

To construct a multiple-scale organized implant surface with super-hydrophilicity. The SiC paper polished titanium disc was sandblasted and treated with HF/HNO₃ and HCl/H₂SO₄, then acid-etched with H₂SO₄/H₂O₂. The physicochemical properties of the surfaces were characterized by scanning electron microscope, static state contact angle and X-ray diffraction. MC3T3-E1 cells were used to evaluate the effects of the surface on the cell adhesion, proliferation and differentiation. The acid-etching process with a mixture of H₂SO₄/H₂O₂ superimposed the nano-scale structure on the micro-scale texture. The multiple-scale implant surface promoted its hydrophilicity and was more favorable to the responses of osteoprogenitor cells, characterized by increased DNA content, enhanced ALP activity and promoted OC production. A multiple-scale implant surface with super-hydrophilicity has been constructed in this study, which facilitates cell proliferation and adhesion.

Production of superparamagnetic nanobiocatalysts for green chemistry applications.

PubMed

Gasser, Christoph A; Ammann, Erik M; Schäffer, Andreas; Shahgaldian, Patrick; Corvini, Philippe F-X

2016-08-01

Immobilization of enzymes on solid supports is a convenient method for increasing enzymatic stability and enabling enzyme reuse. In the present work, a sorption-assisted surface conjugation method was developed and optimized to immobilize enzymes on the surface of superparamagnetic nanoparticles. An oxidative enzyme, i.e., laccase from Trametes versicolor was used as model enzyme. The immobilization method consists of the production of superparamagnetic nanoparticles by co-precipitation of FeCl2 and FeCl3. Subsequently, the particle surface is modified with an organosilane containing an amino group. Next, the enzymes are adsorbed on the particle surface before a cross-linking agent, i.e., glutaraldehyde is added which links the amino groups on the particle surface with the amino groups of the enzymes and leads to internal cross-linking of the enzymes as well. The method was optimized using response surface methodology regarding optimal enzyme and glutaraldehyde amounts, pH, and reaction times. Results allowed formulation of biocatalysts having high specific enzymatic activity and improved stability. The biocatalysts showed considerably higher stability compared with the dissolved enzymes over a pH range from 3 to 9 and in the presence of several chemical denaturants. To demonstrate the reusability of the immobilized enzymes, they were applied as catalysts for the production of a phenoxazinone dye. Virtually, 100 % of the precursor was transformed to the dye in each of the ten conducted reaction cycles while on average 84.5 % of the enzymatic activity present at the beginning of a reaction cycle was retained after each cycle highlighting the considerable potential of superparamagnetic biocatalysts for application in industrial processes.

Deposition of mannose-binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass.

PubMed

Eppa, Łukasz; Pągowska-Klimek, Izabela; Świerzko, Anna S; Moll, Maciej; Krajewski, Wojciech R; Cedzyński, Maciej

2018-04-01

The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1202-1208, 2018. © 2017 Wiley Periodicals, Inc.

Responsive Surface Methodology Optimizes Extraction Conditions of Industrial by-products, Camellia japonica Seed Cake

PubMed Central

Kim, Jae Kyeom; Lim, Ho-Jeong; Kim, Mi-So; Choi, Soo Jung; Kim, Mi-Jeong; Kim, Cho Rong; Shin, Dong-Hoon; Shin, Eui-Cheol

2016-01-01

Background: The central nervous system is easily damaged by oxidative stress due to high oxygen consumption and poor defensive capacity. Hence, multiple studies have demonstrated that inhibiting oxidative stress-induced damage, through an antioxidant-rich diet, might be a reasonable approach to prevent neurodegenerative disease. Objective: In the present study, response surface methodology was utilized to optimize the extraction for neuro-protective constituents of Camellia japonica byproducts. Materials and Methods: Rat pheochromocytoma cells were used to evaluate protective potential of Camellia japonica byproducts. Results: Optimum conditions were 33.84 min, 75.24%, and 75.82°C for time, ethanol concentration and temperature. Further, we demonstrated that major organic acid contents were significantly impacted by the extraction conditions, which may explain varying magnitude of protective potential between fractions. Conclusions: Given the paucity of information in regards to defatted C. japonica seed cake and their health promoting potential, our results herein provide interesting preliminary data for utilization of this byproduct from oil processing in both academic and industrial applications. SUMMARY Neuro-protective potential of C. japonica seed cake on cell viability was affected by extraction conditionsExtraction conditions effectively influenced on active constituents of C. japonica seed cakeBiological activity of C. japonica seed cake was optimized by the responsive surface methodology. Abbreviations used: GC-MS: Gas chromatography-mass spectrometer, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, PC12 cells: Pheochromocytoma, RSM: Response surface methodology. PMID:27601847

Towards a better understanding of flood generation and surface water inundation mechanisms using NASA remote sensing data products

NASA Astrophysics Data System (ADS)

Lucey, J.; Reager, J. T., II; Lopez, S. R.

2017-12-01

Floods annually cause several weather-related fatalities and financial losses. According to NOAA and FEMA, there were 43 deaths and 18 billion dollars paid out in flood insurance policies during 2005. The goal of this work is to improve flood prediction and flood risk assessment by creating a general model of predictability of extreme runoff generation using various NASA products. Using satellite-based flood inundation observations, we can relate surface water formation processes to changes in other hydrological variables, such as precipitation, storage and soil moisture, and understand how runoff generation response to these forcings is modulated by local topography and land cover. Since it is known that a flood event would cause an abnormal increase in surface water, we examine these underlying physical relationships in comparison with the Dartmouth Flood Observatory archive of historic flood events globally. Using ground water storage observations (GRACE), precipitation (TRMM or GPCP), land use (MODIS), elevation (SRTM) and surface inundation levels (SWAMPS), an assessment of geological and climate conditions can be performed for any location around the world. This project utilizes multiple linear regression analysis evaluating the relationship between surface water inundation, total water storage anomalies and precipitation values, grouped by average slope or land use, to determine their statistical relationships and influences on inundation data. This research demonstrates the potential benefits of using global data products for early flood prediction and will improve our understanding of runoff generation processes.

Estimated 2012 groundwater potentiometric surface and drawdown from predevelopment to 2012 in the Santa Fe Group aquifer system in the Albuquerque metropolitan area, central New Mexico

USGS Publications Warehouse

Powell, Rachel I.; McKean, Sarah E.

2014-01-01

Historically, the water-supply requirements of the Albuquerque metropolitan area of central New Mexico were met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. In response to water-level declines, the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began diverting water from the San Juan-Chama Drinking Water Project in December 2008 to reduce the use of groundwater to meet municipal demand. Modifications in the demand for water and the source of the supply of water for the Albuquerque metropolitan area have resulted in a variable response in the potentiometric surface of the production zone (the interval of the aquifer, from within about 200 feet below the water table to 900 feet or more, in which supply wells generally are screened) of the Santa Fe Group aquifer system. Analysis of the magnitude and spatial distribution of water-level change can help improve the understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies’ efforts to minimize future water-level declines and improve sustainability. The U.S. Geological Survey (USGS), in cooperation with the ABCWUA, has developed an estimate of the 2012 potentiometric surface of the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. This potentiometric surface is the latest in a series of reports depicting the potentiometric surface of the area. This report presents the estimated potentiometric surface during winter (from December to March) of water year 2012 and the estimated changes in potentiometric surface between predevelopment (pre-1961) and water year 2012 for the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. Hydrographs from selected piezometers are included to provide details of historical water-level changes. In general, water-level measurements used for this report were collected in small-diameter observation wells screened over short intervals near the middle of the production zone and were considered to best represent the potentiometric head in the production zone. The water-level measurements were collected by various local and Federal agencies. The water year 2012 potentiometric surface map was created in a geographic information system, and the change in water-level altitude from predevelopment to water year 2012 was calculated. The 2012 potentiometric surface indicates that the general direction of groundwater flow is from the Rio Grande towards clusters of supply wells in the east, north, and west. Water-level changes from predevelopment to 2012 were variable across the Albuquerque metropolitan area. Estimated drawdown from 2008 was spatially variable across the Albuquerque metropolitan area. Hydrographs from piezometers on the east side of the river indicate an increase in the annual highest water-level measurement from 2008 to 2012. Hydrographs from piezometers in the northwest part of the study area indicate either steady decline of the water-level altitude over the period of record or recently variable trends in which water-level altitudes increased for a number of years but have declined since water year 2012.

Production of biodiesel from coastal macroalgae (Chara vulgaris) and optimization of process parameters using Box-Behnken design.

PubMed

Siddiqua, Shaila; Mamun, Abdullah Al; Enayetul Babar, Sheikh Md

2015-01-01

Renewable biodiesels are needed as an alternative to petroleum-derived transport fuels, which contribute to global warming and are of limited availability. Algae biomass, are a potential source of renewable energy, and they can be converted into energy such as biofuels. This study introduces an integrated method for the production of biodiesel from Chara vulgaris algae collected from the coastal region of Bangladesh. The Box-Behnken design based on response surface methods (RSM) used as the statistical tool to optimize three variables for predicting the best performing conditions (calorific value and yield) of algae biodiesel. The three parameters for production condition were chloroform (X1), sodium chloride concentration (X2) and temperature (X3). Optimal conditions were estimated by the aid of statistical regression analysis and surface plot chart. The optimal condition of biodiesel production parameter for 12 g of dry algae biomass was observed to be 198 ml chloroform with 0.75 % sodium chloride at 65 °C temperature, where the calorific value of biodiesel is 9255.106 kcal/kg and yield 3.6 ml.

ENSO-Modulation of Plankton Production in the Northern Gulf of Mexico: A High-Resolution Ocean-Biogeochemical Model Study

NASA Astrophysics Data System (ADS)

Gomez, F. A.; Lee, S. K.; Liu, Y.; Hernandez, F., Jr.; Lamkin, J. T.

2017-12-01

Previous studies have suggested that El Nino-Southern Oscillation (ENSO) plays a role in modulating phytoplankton biomass and the reproductive success of marine species in the Gulf of Mexico (GoM). However, characterizations of ENSO-related ecosystem responses such as plankton production have not been fully addressed for the region. Here we examine ENSO impacts on biogeochemical processes within coastal and open ocean domains in the GoM, using a three dimensional high-resolution ocean-biogeochemical model, forced with historical surface fluxes and river run-off for 1979 - 2014. Enhanced precipitation across southern US during El Nino winter increases freshwater discharge and nutrient load into the GoM mainly via the Mississippi-Atchafalaya River. Those anomalies lead to reduced salinity and greater concentration of dissolved inorganic nitrogen and plankton production in the northern shelf especially during winter. In addition, the frequency of northerly wind anomalies that cool the upper ocean increases during El Nino. The negative surface heat flux anomalies further decrease vertical thermal stratification and thus increase phytoplankton production during early spring in the northern deep GoM.

The GOES-R/JPSS Approach for Identifying Hazardous Low Clouds: Overview and Operational Impacts

NASA Astrophysics Data System (ADS)

Calvert, Corey; Pavolonis, Michael; Lindstrom, Scott; Gravelle, Chad; Terborg, Amanda

2017-04-01

Low ceiling and visibility is a weather hazard that nearly every forecaster, in nearly every National Weather Service (NWS) Weather Forecast Office (WFO), must regularly address. In addition, national forecast centers such as the Aviation Weather Center (AWC), Alaska Aviation Weather Unit (AAWU) and the Ocean Prediction Center (OPC) are responsible for issuing low ceiling and visibility related products. As such, reliable methods for detecting and characterizing hazardous low clouds are needed. Traditionally, hazardous areas of Fog/Low Stratus (FLS) are identified using a simple stand-alone satellite product that is constructed by subtracting the 3.9 and 11 μm brightness temperatures. However, the 3.9-11 μm brightness temperature difference (BTD) has several major limitations. In an effort to address the limitations of the BTD product, the GOES-R Algorithm Working Group (AWG) developed an approach that fuses satellite, Numerical Weather Prediction (NWP) model, Sea Surface Temperature (SST) analyses, and other data sets (e.g. digital surface elevation maps, surface emissivity maps, and surface type maps) to determine the probability that hazardous low clouds are present using a naïve Bayesian classifier. In addition, recent research has focused on blending geostationary (e.g. GOES-R) and low earth orbit (e.g. JPSS) satellite data to further improve the products. The FLS algorithm has adopted an enterprise approach in that it can utilize satellite data from a variety of current and future operational sensors and NWP data from a variety of models. The FLS products are available in AWIPS/N-AWIPS/AWIPS-II and have been evaluated within NWS operations over the last four years as part of the Satellite Proving Ground. Forecaster feedback has been predominantly positive and references to these products within Area Forecast Discussions (AFD's) indicate that the products are influencing operational forecasts. At the request of the NWS, the FLS products are currently being transitioned to NOAA/NESDIS operations, which will ensure that users have long-term access to these products. This paper will provide an overview of the FLS products and illustrate how they are being used to improve transportation safety and efficiency.

Millennial-scale changes of surface and bottom water conditions in the northwestern Pacific during the last deglaciation

NASA Astrophysics Data System (ADS)

Kim, Sunghan; Khim, Boo-Keun; Ikehara, Ken; Itaki, Takuya; Shibahara, Akihiko; Yamamoto, Masanobu

2017-07-01

Changes in water column conditions in the northwestern Pacific during the last 23 ka were reconstructed using geochemical and isotope proxies and redox elemental compositions along with published data (alkenone sea surface temperature (SST) and benthic foraminiferal fauna) at core GH02-1030. Surface water primary productivity in terms of biogenic opal and TOC contents, which mainly represented export production of diatom, was closely related to alkenone (spring-summer) SST and the development of spring-summer mixed layer depth. The different variation patterns of nitrate and silicic acid utilization, estimated by bulk δ15N and δ30Sidiatom values, respectively, are most likely due to the water column denitrification influence on bulk δ15N. Dysoxic bottom water conditions occurred during the Bølling-Allerød (BA) and the Pre-Boreal (PB), which was evident by laminated sediments, abundant dysoxic benthic foraminifers, and increased redox elemental compositions. Although surface water productivity increased during the BA and PB, dysoxic bottom water conditions were caused by a combination of enhanced surface water productivity and reduced ventilation of North Pacific Intermediate Water (NPIW) in response to meltwater input from the high latitude areas. Based on records of core GH02-1030 and other cores in the northwestern Pacific, the Okhotsk Sea, and the Bering Sea, which are all proximal to the modern NPIW source region, dissolved oxygen concentrations of bottom water were more depleted during the BA than PB. Such difference was attributed to more sluggish NPIW ventilation due to more meltwater input during the BA than the PB. The opening or closure of the Bering Strait is critical to the direction of meltwater transport to the northwestern Pacific.

Optimization of phase feeding of starter, grower, and finisher diets for male broilers by mixture experimental design: forty-eight-day production period.

PubMed

Roush, W B; Boykin, D; Branton, S L

2004-08-01

A mixture experiment, a variant of response surface methodology, was designed to determine the proportion of time to feed broiler starter (23% protein), grower (20% protein), and finisher (18% protein) diets to optimize production and processing variables based on a total production time of 48 d. Mixture designs are useful for proportion problems where the components of the experiment (i.e., length of time the diets were fed) add up to a unity (48 d). The experiment was conducted with day-old male Ross x Ross broiler chicks. The birds were placed 50 birds per pen in each of 60 pens. The experimental design was a 10-point augmented simplex-centroid (ASC) design with 6 replicates of each point. Each design point represented the portion(s) of the 48 d that each of the diets was fed. Formulation of the diets was based on NRC standards. At 49 d, each pen of birds was evaluated for production data including BW, feed conversion, and cost of feed consumed. Then, 6 birds were randomly selected from each pen for processing data. Processing variables included live weight, hot carcass weight, dressing percentage, fat pad percentage, and breast yield (pectoralis major and pectoralis minor weights). Production and processing data were fit to simplex regression models. Model terms determined not to be significant (P > 0.05) were removed. The models were found to be statistically adequate for analysis of the response surfaces. A compromise solution was calculated based on optimal constraints designated for the production and processing data. The results indicated that broilers fed a starter and finisher diet for 30 and 18 d, respectively, would meet the production and processing constraints. Trace plots showed that the production and processing variables were not very sensitive to the grower diet.

Investigation of biomass concentration, lipid production, and cellulose content in Chlorella vulgaris cultures using response surface methodology.

PubMed

Aguirre, Ana-Maria; Bassi, Amarjeet

2013-08-01

The microalgae Chlorella vulgaris produce lipids that after extraction from cells can be converted into biodiesel. However, these lipids cannot be efficiently extracted from cells due to the presence of the microalgae cell wall, which acts as a barrier for lipid removal when traditional extraction methods are employed. Therefore, a microalgae system with high lipid productivity and thinner cell walls could be more suitable for lipid production from microalgae. This study addresses the effect of culture conditions, specifically carbon dioxide and sodium nitrate concentrations, on biomass concentration and the ratio of lipid productivity/cellulose content. Optimization of culture conditions was done by response surface methodology. The empirical model for biomass concentration (R(2)  = 96.0%) led to a predicted maximum of 1123.2 mg dw L(-1) when carbon dioxide and sodium nitrate concentrations were 2.33% (v/v) and 5.77 mM, respectively. For lipid productivity/cellulose content ratio (R(2)  = 95.2%) the maximum predicted value was 0.46 (mg lipid L(-1)  day(-1) )(mg cellulose mg biomass(-1) )(-1) when carbon dioxide concentration was 4.02% (v/v) and sodium nitrate concentration was 3.21 mM. A common optimum point for both variables (biomass concentration and lipid productivity/cellulose content ratio) was also found, predicting a biomass concentration of 1119.7 mg dw L(-1) and lipid productivity/cellulose content ratio of 0.44 (mg lipid L(-1)  day(-1) )(mg cellulose mg biomass(-1) )(-1) for culture conditions of 3.77% (v/v) carbon dioxide and 4.01 mM sodium nitrate. The models were experimentally validated and results supported their accuracy. This study shows that it is possible to improve lipid productivity/cellulose content by manipulation of culture conditions, which may be applicable to any scale of bioreactors. Copyright © 2013 Wiley Periodicals, Inc.

Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

Treesearch

E.S. Kane; M.R. Chivers; M.S. Turetsky; C.C. Treat; D.G. Petersen; M. Waldrop; J.W. Harden; A.D. McGuire

2013-01-01

To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2...

Response surface optimization of corn stover pretreatment using dilute phosphoric acid for enzymatic hydrolysis and ethanol production

USDA-ARS?s Scientific Manuscript database

Dilute H3PO4 (0.0 - 2.0%, v/v) was used to pretreat corn stover (10%, w/w) for conversion to ethanol. Pretreatment conditions were optimized for temperature, acid loading, and time using a central composite design. Optimal pretreatment conditions were chosen to promote sugar yields following enzym...

On the sources of vegetation activity variation, and their relation with water balance in Mexico

Treesearch

F. Mora; L.R. Iverson

1998-01-01

Natural landscape surface processes are largely controlled by the relationship between climate and vegetation. Water balance integrates the effects of climate on patterns of vegetation distribution and productivity, and for that season, functional relationships can be established using water balance variables as predictors of vegetation response. In this study, we...

Technical and investigative support for high density digital satellite recording systems

NASA Technical Reports Server (NTRS)

Schultz, R. A.

1982-01-01

Dropout and defect classification are discussed with emphasis on how surface defects responsible for electronic dropouts were identified, what affect various defects could have on the application of tapes to satellite tape recorders (STR), and what type of defects might be field correctable after production of the tape but prior to installation in the STR.

[The influence of microbiological factors on the mass of plastics laminates used for packaging of lactic acid cheese].

PubMed

Steinka, Izabela

2007-01-01

The study aimed at assessing changes of physical properties of package lactic acid cheese and the PA/PE and Cryovac laminates after storage of this products. The fluctuation of water in the product and swelling of packaging caused changes in their mass. The changes in the packaging mass could also result from the interactions between micro-organisms present in product. It was found that staphylococci, enterococci and Escherichia coli were the micro-organisms that had contributed to changes of packaging mass to a highest degree. Changes were described with the help of response surface models.

Expansion and functional properties of extruded snacks enriched with nutrition sources from food processing by-products.

PubMed

Korkerd, Sopida; Wanlapa, Sorada; Puttanlek, Chureerat; Uttapap, Dudsadee; Rungsardthong, Vilai

2016-01-01

Rich sources of protein and dietary fiber from food processing by-products, defatted soybean meal, germinated brown rice meal, and mango peel fiber, were added to corn grit at 20 % (w/w) to produce fortified extruded snacks. Increase of total dietary fiber from 4.82 % (wb) to 5.92-17.80 % (wb) and protein from 5.03 % (wb) to 5.46-13.34 % were observed. The product indicated high expansion and good acceptance tested by sensory panels. There were 22.33-33.53 and 5.30-11.53 fold increase in the phenolics and antioxidant activity in the enriched snack products. The effects of feed moisture content, screw speed, and barrel temperature on expansion and nutritional properties of the extruded products were investigated by using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The snacks extruded with feed moisture 13-15 % (wb) and extrusion temperature at 160-180 °C indicated the products with high preference in terms of expansion ratio between insoluble dietary fiber and soluble dietary fiber balance. The results showed that the by-products could be successfully used for nutritional supplemented expanded snacks.

General circulation model response to production-limited fossil fuel emission estimates.

NASA Astrophysics Data System (ADS)

Bowman, K. W.; Rutledge, D.; Miller, C.

2008-12-01

The differences in emissions scenarios used to drive IPCC climate projections are the largest sources of uncertainty in future temperature predictions. These estimates are critically dependent on oil, gas, and coal production where the extremal variations in fossil fuel production used in these scenarios is roughly 10:1 after 2100. The development of emission scenarios based on production-limited fossil fuel estimates, i.e., total fossil fuel reserves can be reliably predicted from cumulative production, offers the opportunity to significantly reduce this uncertainty. We present preliminary results of the response of the NASA GISS atmospheric general circulation model to input forcings constrained by production-limited cumulative future fossil-fuel CO2 emissions estimates that reach roughly 500 GtC by 2100, which is significantly lower than any of the IPCC emission scenarios. For climate projections performed from 1958 through 2400 and a climate sensitivity of 5C/2xCO2, the change in globally averaged annual mean temperature relative to fixed CO2 does not exceed 3C with most changes occurring at high latitudes. We find that from 2100-2400 other input forcings such as increased in N2O play an important role in maintaining increase surface temperatures.

Quality by design case study: an integrated multivariate approach to drug product and process development.

PubMed

Huang, Jun; Kaul, Goldi; Cai, Chunsheng; Chatlapalli, Ramarao; Hernandez-Abad, Pedro; Ghosh, Krishnendu; Nagi, Arwinder

2009-12-01

To facilitate an in-depth process understanding, and offer opportunities for developing control strategies to ensure product quality, a combination of experimental design, optimization and multivariate techniques was integrated into the process development of a drug product. A process DOE was used to evaluate effects of the design factors on manufacturability and final product CQAs, and establish design space to ensure desired CQAs. Two types of analyses were performed to extract maximal information, DOE effect & response surface analysis and multivariate analysis (PCA and PLS). The DOE effect analysis was used to evaluate the interactions and effects of three design factors (water amount, wet massing time and lubrication time), on response variables (blend flow, compressibility and tablet dissolution). The design space was established by the combined use of DOE, optimization and multivariate analysis to ensure desired CQAs. Multivariate analysis of all variables from the DOE batches was conducted to study relationships between the variables and to evaluate the impact of material attributes/process parameters on manufacturability and final product CQAs. The integrated multivariate approach exemplifies application of QbD principles and tools to drug product and process development.

Equatorial Pacific peak in biological production regulated by nutrient and upwelling during the late Pliocene/early Pleistocene cooling

NASA Astrophysics Data System (ADS)

Etourneau, J.; Robinson, R. S.; Martinez, P.; Schneider, R.

2013-03-01

The largest increase in export production in the eastern Pacific of the last 5.3 Myr (million years) occurred between 2.2 and 1.6 Myr, a time of major climatic and oceanographic reorganization in the region. Here, we investigate the causes of this event using reconstructions of export production, nutrient supply and oceanic conditions across the Pliocene-Pleistocene in the eastern equatorial Pacific (EEP) for the last 3.2 Myr. Our results indicate that the export production peak corresponds to a cold interval marked by high nutrient supply relative to consumption, as revealed by the low bulk sedimentary 15N/14N (δ15N) and alkenone-derived sea surface temperature (SST) values. This ~ 0.6 million years long episode of enhanced delivery of nutrients to the surface of the EEP was predominantly initiated through the upwelling of nutrient-enriched water sourced in high latitudes. In addition, this phenomenon was likely promoted by the regional intensification of upwelling in response to the development of intense Walker and Hadley atmospheric circulations. Increased nutrient consumption in the polar oceans and enhanced denitrification in the equatorial regions restrained nutrient supply and availability and terminated the high export production event.

Developing Initial Response Products Using Data from Optical and SAR Earth Observing Platforms for Natural Disaster Response

NASA Astrophysics Data System (ADS)

Bell, J. R.; Molthan, A.; Dabboor, M.

2016-12-01

After a disaster occurs, decision makers require timely information to assist decision making and support. Earth observing satellites provide tools including optical remote sensors that sample in various spectral bands within the visible, near-infrared, and thermal infrared. However, views from optical sensors can be blocked when clouds are present, and cloud-free observations can be significantly delayed depending upon on their repeat cycle. Synthetic aperture radar (SAR) offers several advantages over optical sensors in terms of spatial resolution and the ability to map the Earth's surface whether skies are clear or cloudy. In cases where both SAR and cloud-free optical data are available, these instruments can be used together to provide additional confidence in what is being observed at the surface. This presentation demonstrates cases where SAR imagery can enhance the usefulness for mapping natural disasters and their impacts to the land surface, specifically from severe weather and flooding. The Missouri and Mississippi River flooding from early in 2016 and damage from hail swath in northwestern Iowa on 17 June 2016 are just two events that will be explored. Data collected specifically from the EO-1 (optical), Landsat (optical) and Sentinel 1 (SAR) missions are used to explore several applicable methodologies to determine which products and methodologies may provide decision makers with the best information to provide actionable information in a timely manner.

Climate Products and Services to Meet the Challenges of Extreme Events

NASA Astrophysics Data System (ADS)

McCalla, M. R.

2008-12-01

The 2002 Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM1)-sponsored report, Weather Information for Surface Transportation: National Needs Assessment Report, addressed meteorological needs for six core modes of surface transportation: roadway, railway, transit, marine transportation/operations, pipeline, and airport ground operations. The report's goal was to articulate the weather information needs and attendant surface transportation weather products and services for those entities that use, operate, and manage America's surface transportation infrastructure. The report documented weather thresholds and associated impacts which are critical for decision-making in surface transportation. More recently, the 2008 Climate Change Science Program's (CCSP) Synthesis and Assessment Product (SAP) 4.7 entitled, Impacts of Climate Change and Variability on Transportation Systems and Infrastructure: Gulf Coast Study, Phase I, included many of the impacts from the OFCM- sponsored report in Table 1.1 of this SAP.2 The Intergovernmental Panel on Climate Change (IPCC) reported that since 1950, there has been an increase in the number of heat waves, heavy precipitation events, and areas of drought. Moreover, the IPCC indicated that greater wind speeds could accompany more severe tropical cyclones.3 Taken together, the OFCM, CCSP, and IPCC reports indicate not only the significance of extreme events, but also the potential increasing significance of many of the weather thresholds and associated impacts which are critical for decision-making in surface transportation. Accordingly, there is a real and urgent need to understand what climate products and services are available now to address the weather thresholds within the surface transportation arena. It is equally urgent to understand what new climate products and services are needed to address these weather thresholds, and articulate what can be done to fill the gap between the existing federal climate products and services and the needed federal climate products and services which will address these weather thresholds. Just as important, as we work to meet the needs, a robust education and outreach program is essential to take full advantage of new products, services and capabilities. To ascertain what climate products and services currently exist to address weather thresholds relative to surface transportation, what climate products and services are needed to address these weather thresholds, and how to bridge the gap between what is available and what is needed, the OFCM surveyed the federal meteorological community. Consistent with the extreme events highlighted in the IPCC report, the OFCM survey categorized the weather thresholds associated with surface transportation into the following extreme event areas: (a) excessive heat, (b) winter precipitation, (c) summer precipitation, (d) high winds, and (e) flooding and coastal inundation. The survey results, the gap analysis, as well as OFCM's planned, follow-on activities with additional categories (i.e., in addition to surface transportation) and weather thresholds will be shared with meeting participants. 1 The OFCM is an interdepartmental office established in response to Public Law 87-843 with the mission to ensure the effective use of federal meteorological resources by leading the systematic coordination of operational weather and climate requirements, products, services, and supporting research among the federal agencies. 2 http://www.climatescience.gov/Library/sap/sap4-7/final-report/sap4-7-final-ch1.pdf 3 http://www.gcrio.org/ipcc/ar4/wg1/faq/ar4wg1faq-3-3.pdf

Impact of the assimilation of satellite soil moisture and LST on the hydrological cycle

NASA Astrophysics Data System (ADS)

Laiolo, Paola; Gabellani, Simone; Delogu, Fabio; Silvestro, Francesco; Rudari, Roberto; Campo, Lorenzo; Boni, Giorgio

2014-05-01

The reliable estimation of hydrological variables (e.g. soil moisture, evapotranspiration, surface temperature) in space and time is of fundamental importance in operational hydrology to improve the forecast of the rainfall-runoff response of catchments and, consequently, flood predictions. Nowadays remote sensing can offer a chance to provide good space-time estimates of several hydrological variables and then improve hydrological model performances especially in environments with scarce ground based data. The aim of this work is to investigate the impacts on the performances of a distributed hydrological model (Continuum) of the assimilation of satellite-derived soil moisture products and Land Surface (LST). In this work three different soil moisture (SM) products, derived by ASCAT sensor, are used. These data are provided by the EUMETSAT's H-SAF (Satellite Application Facility on Support to Operational Hydrology and Water Management) program. The considered soil moisture products are: large scale surface soil moisture (SM OBS 1 - H07), small scale surface soil moisture (SM OBS 2 - H08) and profile index in the roots region (SM DAS 2 - H14). These data are compared with soil moisture estimated by Continuum model on the Orba catchment (800 km2), in the northern part of Italy, for the period July 2012-June 2013. Different assimilation experiments have been performed. The first experiment consists in the assimilation of the SM products by using a simple Nudging technique; the second one is the assimilation of only LST data, derived from MSG satellite, and the third is the assimilation of both SM products and LST. The benefits on the model predictions of discharge, LST and soil moisture dynamics were tested.

Modeling Linkages Between Effective Impervious Surface and Urban Vegetation Productivity in Semi-arid Environments

NASA Astrophysics Data System (ADS)

Shields, C. A.; Tague, C.

2010-12-01

With a majority of the world's population now living in urban areas, the role of vegetation in urban ecosystems warrants increased attention. We address the question of how the fine scale (<5m) spatial arrangement of impervious surfaces affects water available to vegetation, which in turn can significantly impact the productivity of vegetation and uptake of C and N. To gain insight into how landscape features influence vegetation productivity, we use a coupled ecohydrogic model to estimate impacts of the amount and arrangement of impervious surfaces on vegetation water use. We use the model to explore how concepts from research in natural semi-arid ecosystems can be applied in the urban context. Ecological research in semi-arid ecosystems has shown that the arrangement of vegetated and bare surfaces plays a key role in regulating both runoff and ecosystem water use and productivity. Systems that include a mixture of bare and vegetated surfaces, for example, tend to show less runoff and more productivity than those with more homogeneous cover. In some instances, patchiness of bare and vegetated surfaces is more important than total vegetated area in determining rates of runoff and vegetation use of rainfall. In an urban context, impervious surfaces can be viewed as analogous to the bare surfaces present in undeveloped ecosystems. We consider not only the total impervious area (TIA), but also the effect of impervious area with a direct hydrologic connection to the stream network, effective impervious area (EIA). While increases in total impervious area (TIA) have been widely shown to impact catchment hydrology, the role of effective impervious area (EIA) has been less extensively studied. A consensus is emerging from the literature that EIA is as important or even more important than TIA as an indicator of catchment response to urbanization. Ecohydrologic models offer a tool to quantify the role of EIA on water availability and plant productivity and demonstrate the potential of urban areas to act as C or N sinks (and minimize the impacts such as increased storm runoff and degraded downstream water quality). We explore the relative roles of TIA and EIA on water availability and plant productivity in a semi-arid urban environment through a series of modeling exercises. The Regional HydroEcological Simulation System (RHESSys) is used to model a range of impervious surface and vegetation scenarios on a test hillslope in the Mission Creek catchment in Santa Barbara CA. Results indicate that reduced EIA can indeed act to mitigate the impact of TIA on water available to plants. We then implement a modification to the RHESSys model that incorporates patch scale estimates of EIA into simulations of the entire Mission Creek catchment, allowing us to quantify likely catchment-scale impacts of altering EIA.

Productivity and sea surface temperature are correlated with the pelagic larval duration of damselfishes in the Red Sea.

PubMed

Robitzch, Vanessa S N; Lozano-Cortés, Diego; Kandler, Nora M; Salas, Eva; Berumen, Michael L

2016-04-30

We examined the variation of pelagic larval durations (PLDs) among three damselfishes, Dascyllus aruanus, D. marginatus, and D. trimaculatus, which live under the influence of an environmental gradient in the Red Sea. PLDs were significantly correlated with latitude, sea surface temperature (SST), and primary production (CHLA; chlorophyll a concentrations). We find a consistent decrease in PLDs with increasing SST and primary production (CHLA) towards the southern Red Sea among all species. This trend is likely related to higher food availability and increased metabolic rates in that region. We suggest that food availability is a potentially stronger driver of variation in PLD than temperature, especially in highly oligotrophic regions. Additionally, variations in PLDs were particularly high among specimens of D. marginatus, suggesting a stronger response to local environmental differences for endemic species. We also report the first average PLD for this species over a broad geographic range (19.82 ± 2.92 days). Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhancement of Rhamnolipid Production in Residual Soybean Oil by an Isolated Strain of Pseudomonas aeruginosa

NASA Astrophysics Data System (ADS)

de Lima, C. J. B.; França, F. P.; Sérvulo, E. F. C.; Resende, M. M.; Cardoso, V. L.

In the present work, the production of rhamnolipid from residual soybean oil (RSO) from food frying facilities was studied using a strain of Pseudomonas aeruginosa of contaminated lagoon, isolated from a hydrocarbon contaminated soil. The optimization of RSO, amonium nitrate, and brewery residual yeast concentrations was accomplished by a central composite experimental design and surface response analysis. The experiments were performed in 500-mL Erlenmeyer flasks containing 50mL of mineral medium, at 170 rpm and 30±1°C, for a 48-h fermentation period. Rhamnolipid production has been monitored by measurements of surface tension, rhamnose concentration, and emulsifying activity. The best-planned results, located on the central point, have corresponded to 22g/L of RSO, 5.625 g/ L of NH4NO3' and 11.5 g/L of brewery yeast. At the maximum point the values for rhamnose and emulsifying index were 2.2g/L and 100%, respectively.

Optimization of Bromelain-Aided Production of Angiotensin I-Converting Enzyme Inhibitory Hydrolysates from Stone Fish Using Response Surface Methodology

PubMed Central

Auwal, Shehu Muhammad; Zarei, Mohammad; Abdul-Hamid, Azizah; Saari, Nazamid

2017-01-01

The stone fish is an under-utilized sea cucumber with many nutritional and ethno-medicinal values. This study aimed to establish the conditions for its optimum hydrolysis with bromelain to generate angiotensin I-converting enzyme (ACE)-inhibitory hydrolysates. Response surface methodology (RSM) based on a central composite design was used to model and optimize the degree of hydrolysis (DH) and ACE-inhibitory activity. Process conditions including pH (4–7), temperature (40–70 °C), enzyme/substrate (E/S) ratio (0.5%–2%) and time (30–360 min) were used. A pH of 7.0, temperature of 40 °C, E/S ratio of 2% and time of 240 min were determined using a response surface model as the optimum levels to obtain the maximum ACE-inhibitory activity of 84.26% at 44.59% degree of hydrolysis. Hence, RSM can serve as an effective approach in the design of experiments to improve the antihypertensive effect of stone fish hydrolysates, which can thus be used as a value-added ingredient for various applications in the functional foods industries. PMID:28362352

Mining a sea of data: deducing the environmental controls of ocean chlorophyll.

PubMed

Irwin, Andrew J; Finkel, Zoe V

2008-01-01

Chlorophyll biomass in the surface ocean is regulated by a complex interaction of physiological, oceanographic, and ecological factors and in turn regulates the rates of primary production and export of organic carbon to the deep ocean. Mechanistic models of phytoplankton responses to climate change require the parameterization of many processes of which we have limited knowledge. We develop a statistical approach to estimate the response of remote-sensed ocean chlorophyll to a variety of physical and chemical variables. Irradiance over the mixed layer depth, surface nitrate, sea-surface temperature, and latitude and longitude together can predict 83% of the variation in log chlorophyll in the North Atlantic. Light and nitrate regulate biomass through an empirically determined minimum function explaining nearly 50% of the variation in log chlorophyll by themselves and confirming that either light or macronutrients are often limiting and that much of the variation in chlorophyll concentration is determined by bottom-up mechanisms. Assuming the dynamics of the future ocean are governed by the same processes at work today, we should be able to apply these response functions to future climate change scenarios, with changes in temperature, nutrient distributions, irradiance, and ocean physics.

Optimization of ultrasonic-assisted preparation of dietary fiber from corn pericarp using response surface methodology.

PubMed

Wang, Anna; Wu, Ligen; Li, Xiulin

2013-09-01

Corn pericarp, which is an industrial waste of corn starch production, is an important source of dietary fiber in cereals, with claimed health benefits. However, they used to be discarded or utilized as animal feed. The application of pre-ultrasound treatment is critical for achieving rapid preparation of desired components from plant materials and for preserving structural and molecular properties of these compounds. Ultrasonic-assisted preparation was used to produce dietary fiber from corn pericarp using response surface methodology. The optimal particle size of corn pericarp (mesh size 40), the ratio of liquid to solid (25 mL g⁻¹), ultrasonic power (180 W) and ultrasonic time (80 min) were determined based on response surface methodology analysis. The interaction effects of particle size of corn pericarp and ultrasonic time had a highlysignificant effect on the yield of dietary fiber, and a significant effect was shown by ultrasonic power and ultrasonic time. The maximum yield of dietary fiber was 86.84%, which agreed closely with the predicted value. Using ultrasonic-assisted preparation, it may be possible to enhance the yield of dietary fiber from corn pericarp. © 2013 Society of Chemical Industry.

Statistical optimization for lipase production from solid waste of vegetable oil industry.

PubMed

Sahoo, Rajesh Kumar; Kumar, Mohit; Mohanty, Swati; Sawyer, Matthew; Rahman, Pattanathu K S M; Sukla, Lala Behari; Subudhi, Enketeswara

2018-04-21

The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from Bacillus licheniformis, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.

CO2 sensing of La0.875Ca0.125FeO3 in wet vapor: a comparison of experimental results and first-principles calculations.

PubMed

Wang, Xiaofeng; Chen, Yanping; Qin, Hongwei; Li, Ling; Shi, Changmin; Liu, Liang; Hu, Jifan

2015-05-28

Experimental results show that with an increase of relative humidity, the resistance of La0.875Ca0.125FeO3 decreases at room temperature but increases at higher temperatures (140-360 °C). The humid effect at room temperature is due to the movement of H(+) or H3O(+) inside of the condensed water layer on the surface of La0.875Ca0.125FeO3. Regarding the humid effect at high temperatures, the density functional theory (DFT) calculations show that H2O can be adsorbed onto the La0.875Ca0.125FeO3 surface in the molecular and dissociative adsorption configurations, where the La0.875Ca0.125FeO3 surface gains some electrons from H2O or its dissociative products, consistent with our observation. Experimental results also show that CO2 sensing response at high temperatures decreases with an increase of room-temperature relative humidity. DFT calculations indicate that CO2 adsorbed onto the La0.875Ca0.125FeO3(010) surface, where high concentration oxygen adsorption occurs without water adsorption nearby, releases some electrons into the semiconductor surface, playing the role of a donor. The interaction between CO2 and the local La0.875Ca0.125FeO3(010) surface with pre-adsorption of H2O nearby results in some electron transfer from the La0.875Ca0.125FeO3 surface to CO2, which is responsible for the weakening of CO2 response at high temperatures for La0.875Ca0.125FeO3 with an increase of room-temperature relative humidity.

Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis

PubMed Central

Chen, Liye; Ridley, Anna; Hammitzsch, Ariane; Al-Mossawi, Mohammad Hussein; Bunting, Helen; Georgiadis, Dimitris; Chan, Antoni; Kollnberger, Simon; Bowness, Paul

2016-01-01

Objective Human leucocyte antigen (HLA)-B27 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly associated with ankylosing spondylitis (AS). ERAP1 is a key aminopeptidase in HLA class I presentation and can potentially alter surface expression of HLA-B27 free heavy chains (FHCs). We studied the effects of ERAP1 silencing/inhibition/variations on HLA-B27 FHC expression and Th17 responses in AS. Methods Flow cytometry was used to measure surface expression of HLA class I in peripheral blood mononuclear cells (PBMCs) from patients with AS carrying different ERAP1 genotypes (rs2287987, rs30187 and rs27044) and in ERAP1-silenced/inhibited/mutated HLA-B27-expressing antigen presenting cells (APCs). ERAP1-silenced/inhibited APCs were cocultured with KIR3DL2CD3ε-reporter cells or AS CD4+ T cells. Th17 responses of AS CD4+ T cells were measured by interleukin (IL)-17A ELISA and Th17 intracellular cytokine staining. FHC cell surface expression and Th17 responses were also measured in AS PBMCs following ERAP1 inhibition. Results The AS-protective ERAP1 variants, K528R and Q730E, were associated with reduced surface FHC expression by monocytes from patients with AS and HLA-B27-expressing APCs. ERAP1 silencing or inhibition in APCs downregulated HLA-B27 FHC surface expression, reduced IL-2 production by KIR3DL2CD3ε-reporter cells and suppressed the Th17 expansion and IL-17A secretion by AS CD4+ T cells. ERAP1 inhibition of AS PBMCs reduced HLA class I FHC surface expression by monocytes and B cells, and suppressed Th17 expansion. Conclusions ERAP1 activity determines surface expression of HLA-B27 FHCs and potentially promotes Th17 responses in AS through binding of HLA-B27 FHCs to KIR3DL2. Our data suggest that ERAP1 inhibition has potential for AS treatment. PMID:26130142

Quantifying the biological impact of surface ocean light attenuation by colored detrital matter in an ESM using a new optical parameterization

NASA Astrophysics Data System (ADS)

Kim, G. E.; Pradal, M.-A.; Gnanadesikan, A.

2015-08-01

Light attenuation by colored detrital material (CDM) was included in a fully coupled Earth system model (ESM). This study presents a modified parameterization for shortwave attenuation, which is an empirical relationship between 244 concurrent measurements of the diffuse attenuation coefficient for downwelling irradiance, chlorophyll concentration and light absorption by CDM. Two ESM model runs using this parameterization were conducted, with and without light absorption by CDM. The light absorption coefficient for CDM was prescribed as the average of annual composite MODIS Aqua satellite data from 2002 to 2013. Comparing results from the two model runs shows that changes in light limitation associated with the inclusion of CDM decoupled trends between surface biomass and nutrients. Increases in surface biomass were expected to accompany greater nutrient uptake and therefore diminish surface nutrients. Instead, surface chlorophyll, biomass and nutrients increased together. These changes can be attributed to the different impact of light limitation on surface productivity versus total productivity. Chlorophyll and biomass increased near the surface but decreased at greater depths when CDM was included. The net effect over the euphotic zone was less total biomass leading to higher nutrient concentrations. Similar results were found in a regional analysis of the oceans by biome, investigating the spatial variability of response to changes in light limitation using a single parameterization for the surface ocean. In coastal regions, surface chlorophyll increased by 35 % while total integrated phytoplankton biomass diminished by 18 %. The largest relative increases in modeled surface chlorophyll and biomass in the open ocean were found in the equatorial biomes, while the largest decreases in depth-integrated biomass and chlorophyll were found in the subpolar and polar biomes. This mismatch of surface and subsurface trends and their regional dependence was analyzed by comparing the competing factors of diminished light availability and increased nutrient availability on phytoplankton growth in the upper 200 m. Understanding changes in biological productivity requires both surface and depth-resolved information. Surface trends may be minimal or of the opposite sign than depth-integrated amounts, depending on the vertical structure of phytoplankton abundance.

Nutrient limitations to aquatic production along an alluvial groundwater connectivity gradient in semi-arid northwest Australia

NASA Astrophysics Data System (ADS)

Iles, Jordan; Pettit, Neil; Grierson, Pauline

2017-04-01

Primary production of intermittent streams in hot arid regions, such as the geologically ancient Pilbara region of northwest Australia, is strongly limited by both water and nutrient availability. Pulses of allochthonous materials can be significant source of nutrients and carbon during short periods of connected flow. However, during interflow periods, which may last months to years, surface water retracts to a series of surface disconnected pools, where hydrological processes including hyporheic exchange and evapo-concentration of ions are of increasing importance in maintaining bioavailable nutrients for primary production. In the Pilbara, the persistence of individual pools during interflow periods is strongly linked to local topography and connectivity to alluvial groundwater. We might thus expect that autochthonous production is greater in pools that become disconnected from groundwater due to increased concentration of nutrients. We thus investigated the importance of nitrogen (N) and phosphorus (P) limitations on aquatic production along an alluvial groundwater connectivity gradient. First, we used in-situ bottle incubations and a 13C-enriched NaHCO3 isotopic tracer to measure rates of charophyte and phytoplankton production in response to nutrient amendments. Second, we paired a nutrient diffusing substrata limitation experiment with high performance liquid chromatography to i) identify which nutrient(s) limit periphyton production, and ii) how the periphyton community structure changes within pools along the alluvial gradient. Charophyte production was 2 mg C g-1 DW h-1 while phytoplankton production was orders of magnitude less (˜0.01 mg C g-1 DW h-1). Although charophytes showed no clear respiration response to short-term nutrient addition, productivity was positively correlated to both charophyte N and P content (R2 = 0.65, p < 0.001 and R2 = 0.41, p < 0.001 respectively). This relationship was stronger in pools which were disconnected from alluvial groundwater (N: R2 = 0.92, p < 0.001 and P: R2 = 0.77, p < 0.001). Short-term phytoplankton production was N limited in some pools (F > 7.6, p < 0.009) but this was not directly linked to alluvial connectivity. The chemotaxonomic response of periphyton algae to experimental increases of biologically available N and P showed clear shifts in production and community composition, with nitrogen additions aiding in production, whilst P additions alone did not increase production and in some instances inhibited growth of some taxa. Unique photosynthetic pigment peaks were identified in each sample and matched with published values. Clearly both N and P, along with alluvial groundwater connectivity, have significant and complex roles in regulating production in these pools. Altered hydrology due to changing climate or water abstraction may thus have significant but as yet poorly understood impacts on the ecological functioning of intermittent streams.

Influence of basin-scale and mesoscale physical processes on biological productivity in the Bay of Bengal during the summer monsoon

NASA Astrophysics Data System (ADS)

Muraleedharan, K. R.; Jasmine, P.; Achuthankutty, C. T.; Revichandran, C.; Dinesh Kumar, P. K.; Anand, P.; Rejomon, G.

2007-03-01

Physical forcing plays a major role in determining biological processes in the ocean across the full spectrum of spatial and temporal scales. Variability of biological production in the Bay of Bengal (BoB) based on basin-scale and mesoscale physical processes is presented using hydrographic data collected during the peak summer monsoon in July-August, 2003. Three different and spatially varying physical processes were identified in the upper 300 m: (I) anticyclonic warm gyre offshore in the southern Bay; (II) a cyclonic eddy in the northern Bay; and (III) an upwelling region adjacent to the southern coast. In the warm gyre (>28.8 °C), the low salinity (33.5) surface waters contained low concentrations of nutrients. These warm surface waters extended below the euphotic zone, which resulted in an oligotrophic environment with low surface chlorophyll a (0.12 mg m -3), low surface primary production (2.55 mg C m -3 day -1) and low zooplankton biovolume (0.14 ml m -3). In the cyclonic eddy, the elevated isopycnals raised the nutricline upto the surface (NO 3-N > 8.2 μM, PO 4-P > 0.8 μM, SiO 4-Si > 3.5 μM). Despite the system being highly eutrophic, response in the biological activity was low. In the upwelling zone, although the nutrient concentrations were lower compared to the cyclonic eddy, the surface phytoplankton biomass and production were high (Chl a - 0.25 mg m -3, PP - 9.23 mg C m -3 day -1), and mesozooplankton biovolume (1.12 ml m -3) was rich. Normally in oligotrophic, open ocean ecosystems, primary production is based on ‘regenerated’ nutrients, but during episodic events like eddies the ‘production’ switches over to ‘new production’. The switching over from ‘regenerated production’ to ‘new production’ in the open ocean (cyclonic eddy) and establishment of a new phytoplankton community will take longer than in the coastal system (upwelling). Despite the functioning of a cyclonic eddy and upwelling being divergent (transporting of nutrients from deeper waters to surface), the utilization of nutrients leading to enhanced biological production and its transfer to upper trophic levels in the upwelling region imply that the energy transfer from primary production to secondary production (mesozooplankton) is more efficient than in the cyclonic eddy of the open ocean. The results suggest that basin-scale and mesoscale processes influence the abundance and spatial heterogeneity of plankton populations across a wide spatial scale in the BoB. The multifaceted effects of these physical processes on primary productivity thus play a prominent role in structuring of zooplankton communities and could consecutively affect the recruitment of pelagic fisheries.

Advanced Oxidation Protein Products-Modified Albumin Induces Differentiation of RAW264.7 Macrophages into Dendritic-Like Cells Which Is Modulated by Cell Surface Thiols.

PubMed

Garibaldi, Silvano; Barisione, Chiara; Marengo, Barbara; Ameri, Pietro; Brunelli, Claudio; Balbi, Manrico; Ghigliotti, Giorgio

2017-01-10

Local accumulation of Advanced Oxidation Protein Products (AOPP) induces pro-inflammatory and pro-fibrotic processes in kidneys and is an independent predictor of renal fibrosis and of rapid decline of eGFR in patients with chronic kidney disease (CKD). In addition to kidney damage, circulating AOPP may be regarded as mediators of systemic oxidative stress and, in this capacity, they might play a role in the progression of atherosclerotic damage of arterial walls. Atherosclerosis is a chronic inflammatory disease that involves activation of innate and adaptive immunity. Dendritic cells (DCs) are key cells in this process, due to their role in antigen presentation, inflammation resolution and T cell activation. AOPP consist in oxidative modifications of proteins (such as albumin and fibrinogen) that mainly occur through myeloperoxidase (MPO)-derived hypochlorite (HOCl). HOCl modified proteins have been found in atherosclerotic lesions. The oxidizing environment and the shifts in cellular redox equilibrium trigger inflammation, activate immune cells and induce immune responses. Thus, surface thiol groups contribute to the regulation of immune functions. The aims of this work are: (1) to evaluate whether AOPP-proteins induce activation and differentiation of mature macrophages into dendritic cells in vitro; and (2) to define the role of cell surface thiol groups and of free radicals in this process. AOPP-proteins were prepared by in vitro incubation of human serum albumin (HSA) with HOCl. Mouse macrophage-like RAW264.7 were treated with various concentrations of AOPP-HSA with or without the antioxidant N -acetyl cysteine (NAC). Following 48 h of HSA-AOPP treatment, RAW264.7 morphological changes were evaluated by microscopic observation, while markers of dendritic lineage and activation (CD40, CD86, and MHC class II) and allogeneic T cell proliferation were evaluated by flow cytometry. Cell surface thiols were measured by AlexaFluor-maleimide binding, and ROS production was assessed as DCF fluorescence by flow cytometry. HSA-AOPP induced the differentiation of RAW264.7 cells into a dendritic-like phenotype, as shown by morphological changes, by increased CD40, CD86 and MHC class II surface expression and by induction of T cell proliferation. The cell surface thiols dose dependently decreased following HSA-AOPP treatment, while ROS production increased. NAC pre-treatment enhanced the amount of cell surface thiols and prevented their reduction due to treatment with AOPP. Both ROS production and RAW264.7 differentiation into DC-like cells induced by HSA-AOPP were reduced by NAC. Our results highlight that oxidized plasma proteins modulate specific immune responses of macrophages through a process involving changes in the thiol redox equilibrium. We suggest that this mechanism may play a role in determining the rapid progression of the atherosclerotic process observed in CKD patients.

Drought effects on soil carbon dioxide production in two ecosystems in Central Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

van Straaten, Oliver

2010-05-01

Drought response on soil CO2 production dynamics were examined in two tropical ecosystems in central Sulawesi, Indonesia. Large-scale throughfall displacement roofs were built in a cacao (Theobroma cacao) / Gliricidia sepium agroforestry plantation (560 m.a.s.l.) and in a sub-montane tropical rainforest (1050 m.a.s.l.) to simulate drought conditions. At each site, ecosystem drought responses from three roof plots were compared to three undisturbed control plots. Soil CO2 production was measured spatially at the soil surface and vertically within the soil profile to 2.5 m depth every two weeks. 1. The cacao / Gliricidia ecosystem exhibited a mild drought response. Here, soil CO2 production decreased by 13% in comparison to the control plots during the 13 month induced drought. The mild drought response is attributed to two reasons. First, soil CO2 efflux exhibited an inverse parabolic relationship with soil moisture (R2 = 0.32): soil CO2 efflux peaked at intermediate moisture conditions, but was low when soil conditions became dry (in the induced drought plots), and when the soil became water saturated (in the control plots). This means that respiration differences between control and roof plots may have been masked when soil moisture conditions were saturated in the control and concurrently dry in roof plots. Secondly, the shallow rooted cacao understory grown next to the deeper rooted Gliricidia overstory created a favourable set of site conditions that enabled the ecosystem to mitigate serious drought stress. The experiment had a CO2 neutral effect overall: emissions were initially reduced during the induced drought period but rebounded and surpassed the control during the five month rewetting phase, thus compensating for earlier declines. 2. In contrast, the sub-montane tropical rainforest experienced a severe decrease in soil CO2 production. Here, soil CO2 efflux decreased by an average of 39% in comparison to the control during the 24 month induced drought period. Soil moisture, the main variable controlling CO2, exhibited a strong positive linear relationship with soil CO2 production (R2 = 0.72). A two phase ecosystem drought response was observed. During the first phase, which lasted nine months, leaf litter respiration declined while the total respiration from autotrophic and belowground heterotrophic sources remained relatively unchanged, although an upward shift from the subsoil to the soil surface was measured. During the second phase of the experiment, when drought conditions intensified further (the next 16 months), belowground CO2 production from heterotrophic and autotrophic sources decreased at all soil depths. Leaf litter respiration remained negligible. Recuperation after the drought was slow in this ecosystem and did not rebound to control plot levels. In this ecosystem, the simulated drought resulted in a reduction in overall CO2 emission.

Organic acid pretreatment of oil palm trunk: effect on enzymatic saccharification and ethanol production.

PubMed

Rattanaporn, Kittipong; Tantayotai, Prapakorn; Phusantisampan, Theerawut; Pornwongthong, Peerapong; Sriariyanun, Malinee

2018-04-01

Effective lignocellulosic biomass saccharification is one of the crucial requirements of biofuel production via fermentation process. Organic acid pretreatments have been gained much interests as one of the high potential methods for promoting enzymatic saccharification of lignocellulosic materials due to their lower hazardous properties and lower production of inhibitory by-products of fermentation than typical chemical pretreatment methods. In this study, three organic acids, including acetic acid, oxalic acid, and citric acid, were examined for improvement of enzymatic saccharification and bioethanol production from oil palm trunk biomass. Based on response surface methodology, oxalic acid pretreated biomass released the maximum reducing sugar of 144 mg/g-pretreated biomass at the optimum condition, which was higher than untreated samples for 2.30 times. The released sugar yield of oil palm trunk also corresponded to the results of FT-IR analysis, which revealed the physical modification of cellulose and hemicellulose surface structures of pretreated biomass. Nevertheless, citric acid pretreatment is the most efficient pretreatment method to improve bioethanol fermentation of Saccharomyces cerevisiae TISTR 5606 at 1.94 times higher than untreated biomass. These results highlighted the selection of organic acid pretreatment as a potential method for biofuel production from oil palm trunk feedstocks.

Production of Sterilizing Agents from Calendula officinalis Extracts Optimized by Response Surface Methodology

PubMed Central

Goktas, Fatih Mehmet; Sahin, Bilgesu; Yigitarslan, Sibel

2015-01-01

The aim of this study was to produce hand sterilizing liquid and wet wipes with the extracts of Calendula officinalis. Since this plant has well known antimicrobial activity due to its phytochemical constituents, the increase in the extraction yield was chosen as the principle part of the production process. To achieve the maximum yield, parameters of solid-to-liquid ratio, extraction temperature, and time were studied. The optimum conditions were determined by response surface methodology as 41°C, 7 h, and 3.3 g/200 mL for temperature, time, and solid-to-liquid ratio, respectively. The yield achieved at those conditions was found to be 90 percent. The highest amounts of flavonoids were detected at optimum, whereas the highest triterpene and saponin constituents were determined at different design points. The microbial efficiencies of extracts were determined by the inhibition of the growth of selected microorganisms. Different dilution rates and interaction times were used as parameters of inhibition. Not any of the constituent but symbiotic relation in-between reached the highest inhibition of 90 percent. The pH values of the extracts were 5.1 to 5.4. As a result, the extraction of Calendula officinalis at the optimum conditions can be used effectively in the production of wet wipes and hand sterilizing liquid. PMID:26064122

Kinetic modelling and optimisation of antimicrobial compound production by Candida pyralidae KU736785 for control of Candida guilliermondii.

PubMed

Mewa-Ngongang, Maxwell; du Plessis, Heinrich W; Hutchinson, Ucrecia F; Mekuto, Lukhanyo; Ntwampe, Seteno Ko

2017-06-01

Biological antimicrobial compounds from yeast can be used to address the critical need for safer preservatives in food, fruit and beverages. The inhibition of Candida guilliermondii, a common fermented beverage spoilage organism, was achieved using antimicrobial compounds produced by Candida pyralidae KU736785. The antimicrobial production system was modelled and optimised using response surface methodology, with 22.5 ℃ and pH of 5.0 being the optimum conditions. A new concept for quantifying spoilage organism inhibition was developed. The inhibition activity of the antimicrobial compounds was observed to be at a maximum after 17-23 h of fermentation, with C. pyralidae concentration being between 0.40 and 1.25 × 10 9 CFU ml -1 , while its maximum specific growth rate was 0.31-0.54 h -1 . The maximum inhibitory activity was between 0.19 and 1.08 l contaminated solidified media per millilitre of antimicrobial compound used. Furthermore, the antimicrobial compound formation rate was 0.037-0.086 l VZI ml -1 ACU h -1 , respectively. The response surface methodology analysis showed that the model developed sufficiently described the antimicrobial compound formation rate 1.08 l VZI ml -1 ACU, as 1.17 l VZI ml -1 ACU, predicted under the optimum production conditions.

Response Surface Optimization for Decaffeination and Theophylline Production by Fusarium solani.

PubMed

Nanjundaiah, Shwetha; Bhatt, Praveena; Rastogi, Navin Kumar; Thakur, Munna Singh

2016-01-01

Coffee processing industries generate caffeine-containing waste that needs to be treated and decaffeinated before being disposed. Five fungal isolates obtained on caffeine-containing mineral media were tested for their ability to utilize caffeine at high concentrations. An isolate identified as Fusarium solani could utilize caffeine as a sole source of carbon and nitrogen up to 5 g/l and could degrade it to an extent of 30-53 % in 120 h. Sucrose that was added as an auxiliary substrate (5 g/l) enhanced the biodecaffeination of caffeine to 88 % in 96 h. The addition of co- substrate (sucrose) not only resulted in higher biodecaffeination efficiency, but also reduced the incubation period from the initial 120 to 96 h. Theophylline and 3-methyl xanthine were obtained as the major metabolites of decaffeination at 96 and 120 h, respectively. Response surface methodology used to optimize the process parameters for maximum biodecaffeination as well as theophylline production showed that a pH of 5.8, temperature of 24 °C and inoculum size of 4.8 × 10(5) spores/ml have resulted in a complete biodecaffeination of caffeine as well as the production of theophylline with a yield of 33 % (w/w). Results thus show that a viable and sustainable process can be developed for the detoxification of caffeine along with the recovery of theophylline, a commercially important chemical.

The SENTINEL-3 Mission: Overview and Status

NASA Astrophysics Data System (ADS)

Benveniste, J.; Mecklenburg, S.

2015-12-01

The Copernicus Programme, being Europe's Earth Observation and Monitoring Programme led by the European Union, aims to provide, on a sustainable basis, reliable and timely services related to environmental and security issues. The Sentinel-3 mission forms part of the Copernicus Space Component. Its main objectives, building on the heritage and experience of the European Space Agency's (ESA) ERS and ENVISAT missions, are to measure sea-surface topography, sea- and land-surface temperature and ocean- and land-surface colour in support of ocean forecasting systems, and for environmental and climate monitoring. The series of Sentinel-3 satellites will ensure global, frequent and near-real time ocean, ice and land monitoring, with the provision of observation data in routine, long term (up to 20 years of operations) and continuous fashion, with a consistent quality and a high level of reliability and availability. The Sentinel-3 missions will be jointly operated by ESA and EUMETSAT. ESA will be responsible for the operations, maintenance and evolution of the Sentinel-3 ground segment on land related products and EUMETSAT for the marine products. The Sentinel-3 ground segment systematically acquires, processes and distributes a set of pre-defined core data products. Sentinel-3A is foreseen to be launched at the beginning of November 2015. The paper will give an overview on the mission, its instruments and objectives, the data products provided, the mechanisms to access the mission's data, and if available first results.

A Host-Pathogen Interaction Reduced to First Principles: Antigenic Variation in T. brucei.

PubMed

Hovel-Miner, Galadriel; Mugnier, Monica; Papavasiliou, F Nina; Pinger, Jason; Schulz, Danae

2015-01-01

Antigenic variation is a common microbial survival strategy, powered by diversity in expressed surface antigens across the pathogen population over the course of infection. Even so, among pathogens, African trypanosomes have the most comprehensive system of antigenic variation described. African trypanosomes (Trypanosoma brucei spp.) are unicellular parasites native to sub-Saharan Africa, and the causative agents of sleeping sickness in humans and of n'agana in livestock. They cycle between two habitats: a specific species of fly (Glossina spp. or, colloquially, the tsetse) and the bloodstream of their mammalian hosts, by assuming a succession of proliferative and quiescent developmental forms, which vary widely in cell architecture and function. Key to each of the developmental forms that arise during these transitions is the composition of the surface coat that covers the plasma membrane. The trypanosome surface coat is extremely dense, covered by millions of repeats of developmentally specified proteins: procyclin gene products cover the organism while it resides in the tsetse and metacyclic gene products cover it while in the fly salivary glands, ready to make the transition to the mammalian bloodstream. But by far the most interesting coat is the Variant Surface Glycoprotein (VSG) coat that covers the organism in its infectious form (during which it must survive free living in the mammalian bloodstream). This coat is highly antigenic and elicits robust VSG-specific antibodies that mediate efficient opsonization and complement mediated lysis of the parasites carrying the coat against which the response was made. Meanwhile, a small proportion of the parasite population switches coats, which stimulates a new antibody response to the prevalent (new) VSG species and this process repeats until immune system failure. The disease is fatal unless treated, and treatment at the later stages is extremely toxic. Because the organism is free living in the blood, the VSG:antibody surface represents the interface between pathogen and host, and defines the interaction of the parasite with the immune response. This interaction (cycles of VSG switching, antibody generation, and parasite deletion) results in stereotypical peaks and troughs of parasitemia that were first recognized more than 100 years ago. Essentially, the mechanism of antigenic variation in T. brucei results from a need, at the population level, to maintain an extensive repertoire, to evade the antibody response. In this chapter, we will examine what is currently known about the VSG repertoire, its depth, and the mechanisms that diversify it both at the molecular (DNA) and at the phenotypic (surface displayed) level, as well as how it could interact with antibodies raised specifically against it in the host.

Production of highly efficient activated carbons from industrial wastes for the removal of pharmaceuticals from water-A full factorial design.

PubMed

Jaria, Guilaine; Silva, Carla Patrícia; Oliveira, João A B P; Santos, Sérgio M; Gil, María Victoria; Otero, Marta; Calisto, Vânia; Esteves, Valdemar I

2018-02-26

The wide occurrence of pharmaceuticals in aquatic environments urges the development of cost-effective solutions for their removal from water. In a circular economy context, primary paper mill sludge (PS) was used to produce activated carbon (AC) aiming the adsorptive removal of these contaminants. The use of low-cost precursors for the preparation of ACs capable of competing with commercial ACs continues to be a challenge. A full factorial design of four factors (pyrolysis temperature, residence time, precursor/activating agent ratio, and type of activating agent) at two levels was applied to the production of AC using PS as precursor. The responses analysed were the yield of production, percentage of adsorption for three pharmaceuticals (sulfamethoxazole, carbamazepine, and paroxetine), specific surface area (S BET ), and total organic carbon (TOC). Statistical analysis was performed to evaluate influencing factors in the responses and to determine the most favourable production conditions. Four ACs presented very good responses, namely on the adsorption of the pharmaceuticals under study (average adsorption percentage around 78%, which is above that of commercial AC), and S BET between 1389 and 1627 m 2  g -1 . A desirability analysis pointed out 800 °C for 60 min and a precursor/KOH ratio of 1:1 (w/w) as the optimal production conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of Plackett-Burman Experimental Design for Lipase Production by Aspergillus niger Using Shea Butter Cake

PubMed Central

Salihu, Aliyu; Bala, Muntari; Bala, Shuaibu M.

2013-01-01

Plackett-Burman design was used to efficiently select important medium components affecting the lipase production by Aspergillus niger using shea butter cake as the main substrate. Out of the eleven medium components screened, six comprising of sucrose, (NH4)2SO4, Na2HPO4, MgSO4, Tween-80, and olive oil were found to contribute positively to the overall lipase production with a maximum production of 3.35 U/g. Influence of tween-80 on lipase production was investigated, and 1.0% (v/w) of tween-80 resulted in maximum lipase production of 6.10 U/g. Thus, the statistical approach employed in this study allows for rapid identification of important medium parameters affecting the lipase production, and further statistical optimization of medium and process parameters can be explored using response surface methodology. PMID:25937979

Application of Plackett-Burman Experimental Design for Lipase Production by Aspergillus niger Using Shea Butter Cake.

PubMed

Salihu, Aliyu; Bala, Muntari; Bala, Shuaibu M

2013-01-01

Plackett-Burman design was used to efficiently select important medium components affecting the lipase production by Aspergillus niger using shea butter cake as the main substrate. Out of the eleven medium components screened, six comprising of sucrose, (NH4)2SO4, Na2HPO4, MgSO4, Tween-80, and olive oil were found to contribute positively to the overall lipase production with a maximum production of 3.35 U/g. Influence of tween-80 on lipase production was investigated, and 1.0% (v/w) of tween-80 resulted in maximum lipase production of 6.10 U/g. Thus, the statistical approach employed in this study allows for rapid identification of important medium parameters affecting the lipase production, and further statistical optimization of medium and process parameters can be explored using response surface methodology.

Warpage optimisation on the moulded part with straight-drilled and conformal cooling channels using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

NASA Astrophysics Data System (ADS)

Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.

2017-09-01

In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.

Design Expert Supported Mathematical Optimization and Predictability Study of Buccoadhesive Pharmaceutical Wafers of Loratadine

PubMed Central

Dey, Surajit; Parcha, Versha; Bhattacharya, Shiv Sankar; Ghosh, Amitava

2013-01-01

Objective. The objective of this work encompasses the application of the response surface approach in the development of buccoadhesive pharmaceutical wafers of Loratadine (LOR). Methods. Experiments were performed according to a 32 factorial design to evaluate the effects of buccoadhesive polymer, sodium alginate (A), and lactose monohydrate as ingredient, of hydrophilic matrix former (B) on the bioadhesive force, disintegration time, percent (%) swelling index, and time taken for 70% drug release (t 70%). The effect of the two independent variables on the response variables was studied by response surface plots and contour plots generated by the Design-Expert software. The desirability function was used to optimize the response variables. Results. The compatibility between LOR and the wafer excipients was confirmed by differential scanning calorimetry, FTIR spectroscopy, and X-ray diffraction (XRD) analysis. Bioadhesion force, measured with TAXT2i texture analyzer, showed that the wafers had a good bioadhesive property which could be advantageous for retaining the drug into the buccal cavity. Conclusion. The observed responses taken were in agreement with the experimental values, and Loratadine wafers were produced with less experimental trials, and a patient compliant product was achieved with the concept of formulation by design. PMID:23781498

Defatted flaxseed meal incorporated corn-rice flour blend based extruded product by response surface methodology.

PubMed

Ganorkar, Pravin M; Patel, Jhanvi M; Shah, Vrushti; Rangrej, Vihang V

2016-04-01

Considering the evidence of flaxseed and its defatted flaxseed meal (DFM) for human health benefits, response surface methodology (RSM) based on three level four factor central composite rotatable design (CCRD) was employed for the development of DFM incorporated corn - rice flour blend based extruded snack. The effect of DFM fortification (7.5-20 %), moisture content of feed (14-20 %, wb), extruder barrel temperature (115-135 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), overall acceptability (OAA) score and water solubility index (WSI) of extrudates were investigated using central composite rotatable design (CCRD). Significant regression models explained the effect of considered variables on all responses. DFM incorporation level was found to be most significant independent variable affecting on extrudates characteristics followed by extruder barrel temperature and then screw rpm. Feed moisture content did not affect extrudates characteristics. As DFM level increased (7.5 % to 20 %), ER and OAA value decreased. However, BS and WSI values were found to increase with increase in DFM level. Based on the defined criteria for numerical optimization, the combination for the production of DFM incorporated extruded snack with desired sensory attributes was achieved by incorporating 10 % DFM (replacing rice flour in flour blend) and by keeping 20 % moisture content, 312 screw rpm and 125 °C barrel temperature.

Obtaining ready-to-eat blue corn expanded snacks with anthocyanins using an extrusion process and response surface methodology.

PubMed

Escalante-Aburto, Anayansi; Ramírez-Wong, Benjamín; Torres-Chávez, Patricia Isabel; López-Cervantes, Jaime; Figueroa-Cárdenas, Juan de Dios; Barrón-Hoyos, Jesús Manuel; Morales-Rosas, Ignacio; Ponce-García, Néstor; Gutiérrez-Dorado, Roberto

2014-12-15

Extrusion is an alternative technology for the production of nixtamalized products. The aim of this study was to obtain an expanded nixtamalized snack with whole blue corn and using the extrusion process, to preserve the highest possible total anthocyanin content, intense blue/purple coloration (color b) and the highest expansion index. A central composite experimental design was used. The extrusion process factors were: feed moisture (FM, 15%-23%), calcium hydroxide concentration (CHC, 0%-0.25%) and final extruder temperature (T, 110-150 °C). The chemical and physical properties evaluated in the extrudates were moisture content (MC, %), total anthocyanins (TA, mg·kg(-1)), pH, color (L, a, b) and expansion index (EI). ANOVA and surface response methodology were applied to evaluate the effects of the extrusion factors. FM and T significantly affected the response variables. An optimization step was performed by overlaying three contour plots to predict the best combination region. The extrudates were obtained under the following optimum factors: FM (%) = 16.94, CHC (%) = 0.095 and T (°C) = 141.89. The predicted extrusion processing factors were highly accurate, yielding an expanded nixtamalized snack with 158.87 mg·kg(-1) TA (estimated: 160 mg·kg(-1)), an EI of 3.19 (estimated: 2.66), and color parameter b of -0.44 (estimated: 0.10).

Prevalent vegetation growth enhancement in urban environment.

PubMed

Zhao, Shuqing; Liu, Shuguang; Zhou, Decheng

2016-05-31

Urbanization, a dominant global demographic trend, leads to various changes in environments (e.g., atmospheric CO2 increase, urban heat island). Cities experience global change decades ahead of other systems so that they are natural laboratories for studying responses of other nonurban biological ecosystems to future global change. However, the impacts of urbanization on vegetation growth are not well understood. Here, we developed a general conceptual framework for quantifying the impacts of urbanization on vegetation growth and applied it in 32 Chinese cities. Results indicated that vegetation growth, as surrogated by satellite-observed vegetation index, decreased along urban intensity across all cities. At the same time, vegetation growth was enhanced at 85% of the places along the intensity gradient, and the relative enhancement increased with urban intensity. This growth enhancement offset about 40% of direct loss of vegetation productivity caused by replacing productive vegetated surfaces with nonproductive impervious surfaces. In light of current and previous field studies, we conclude that vegetation growth enhancement is prevalent in urban settings. Urban environments do provide ideal natural laboratories to observe biological responses to environmental changes that are difficult to mimic in manipulative experiments. However, one should be careful in extrapolating the finding to nonurban environments because urban vegetation is usually intensively managed, and attribution of the responses to diverse driving forces will be challenging but must be pursued.

Synthesis of structured triacylglycerols containing caproic acid by lipase-catalyzed acidolysis: optimization by response surface methodology.

PubMed

Zhou, D; Xu, X; Mu, H; Høy, C E; Adler-Nissen, J

2001-12-01

Production in a batch reactor with a solvent-free system of structured triacylglycerols containing short-chain fatty acids by Lipozyme RM IM-catalyzed acidolysis between rapeseed oil and caproic acid was optimized using response surface methodology (RSM). Reaction time (t(r)), substrate ratio (S(r)), enzyme load (E(l), based on substrate), water content (W(c), based on enzyme), and reaction temperature (T(e)), the five most important parameters for the reaction, were chosen for the optimization. The range of each parameter was selected as follows: t(r) = 5-17 h; E(l) = 6-14 wt %; T(e) = 45-65 degrees C; S(r) = 2-6 mol/mol; and W(c) = 2-12 wt %. The biocatalyst was Lipozyme RM IM, in which Rhizomucor miehei lipase is immobilized on a resin. The incorporation of caproic acid into rapeseed oil was the main monitoring response. In addition, the contents of mono-incorporated structured triacylglycerols and di-incorporated structured triacylglycerols were also evaluated. The optimal reaction conditions for the incorporation of caproic acid and the content of di-incorporated structured triacylglycerols were as follows: t(r) = 17 h; S(r) = 5; E(l) = 14 wt %; W(c) = 10 wt %; T(e) = 65 degrees C. At these conditions, products with 55 mol % incorporation of caproic acid and 55 mol % di-incorporated structured triacylglycerols were obtained.

Prevalent vegetation growth enhancement in urban environment

PubMed Central

Zhao, Shuqing; Liu, Shuguang; Zhou, Decheng

2016-01-01

Urbanization, a dominant global demographic trend, leads to various changes in environments (e.g., atmospheric CO2 increase, urban heat island). Cities experience global change decades ahead of other systems so that they are natural laboratories for studying responses of other nonurban biological ecosystems to future global change. However, the impacts of urbanization on vegetation growth are not well understood. Here, we developed a general conceptual framework for quantifying the impacts of urbanization on vegetation growth and applied it in 32 Chinese cities. Results indicated that vegetation growth, as surrogated by satellite-observed vegetation index, decreased along urban intensity across all cities. At the same time, vegetation growth was enhanced at 85% of the places along the intensity gradient, and the relative enhancement increased with urban intensity. This growth enhancement offset about 40% of direct loss of vegetation productivity caused by replacing productive vegetated surfaces with nonproductive impervious surfaces. In light of current and previous field studies, we conclude that vegetation growth enhancement is prevalent in urban settings. Urban environments do provide ideal natural laboratories to observe biological responses to environmental changes that are difficult to mimic in manipulative experiments. However, one should be careful in extrapolating the finding to nonurban environments because urban vegetation is usually intensively managed, and attribution of the responses to diverse driving forces will be challenging but must be pursued. PMID:27185955

Early Spring Post-Fire Snow Albedo Dynamics in High Latitude Boreal Forests Using Landsat-8 OLI Data

NASA Technical Reports Server (NTRS)

Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Roman, Miguel O.

2016-01-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (less than 100 m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high-burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500 m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems.

Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data

PubMed Central

Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Román, Miguel O.

2018-01-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems. PMID:29769751

Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data.

PubMed

Wang, Zhuosen; Erb, Angela M; Schaaf, Crystal B; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A; Román, Miguel O

2016-11-01

Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems.

HLA-B27-Homodimer-Specific Antibody Modulates the Expansion of Pro-Inflammatory T-Cells in HLA-B27 Transgenic Rats.

PubMed

Marroquin Belaunzaran, Osiris; Kleber, Sascha; Schauer, Stefan; Hausmann, Martin; Nicholls, Flora; Van den Broek, Maries; Payeli, Sravan; Ciurea, Adrian; Milling, Simon; Stenner, Frank; Shaw, Jackie; Kollnberger, Simon; Bowness, Paul; Petrausch, Ulf; Renner, Christoph

2015-01-01

HLA-B27 is a common genetic risk factor for the development of Spondyloarthritides (SpA). HLA-B27 can misfold to form cell-surface heavy chain homodimers (B272) and induce pro-inflammatory responses that may lead to SpA pathogenesis. The presence of B272 can be detected on leukocytes of HLA-B27+ Ankylosing spondylitis (AS) patients and HLA-B27 transgenic rats. We characterized a novel B272-specific monoclonal antibody to study its therapeutic use in HLA-B27 associated disorders. The monoclonal HD5 antibody was selected from a phage library to target cell-surface B272 homodimers and characterized for affinity, specificity and ligand binding. The immune modulating effect of HD5 was tested in HLA-B27 transgenic rats. Onset and progression of disease profiles were monitored during therapy. Cell-surface B272 and expansion of pro-inflammatory cells from blood, spleen and draining lymph nodes were assessed by flow cytometry. HD5 bound B272 with high specificity and affinity (Kd = 0.32 nM). HD5 blocked cell-surface interaction of B272 with immune regulatory receptors KIR3DL2, LILRB2 and Pirb. In addition, HD5 modulated the production of TNF from CD4+ T-cells by limiting B272 interactions in vitro. In an HLA-B27 transgenic rat model repetitive dosing of HD5 reduced the expansion of pro-inflammatory CD4+ T-cells, and decreased the levels of soluble TNF and number of cell-surface B272 molecules. HD5 predominantly inhibits early TNF production and expansion of pro-inflammatory CD4+ T-cells in HLA-B27 transgenic rats. Monoclonal antibodies targeting cell-surface B272 propose a new concept for the modulation of inflammatory responses in HLA-B27 related disorders.

HLA-B27-Homodimer-Specific Antibody Modulates the Expansion of Pro-Inflammatory T-Cells in HLA-B27 Transgenic Rats

PubMed Central

Marroquin Belaunzaran, Osiris; Kleber, Sascha; Schauer, Stefan; Hausmann, Martin; Nicholls, Flora; Van den Broek, Maries; Payeli, Sravan; Ciurea, Adrian; Milling, Simon; Stenner, Frank; Shaw, Jackie; Kollnberger, Simon; Bowness, Paul; Petrausch, Ulf; Renner, Christoph

2015-01-01

Objectives HLA-B27 is a common genetic risk factor for the development of Spondyloarthritides (SpA). HLA-B27 can misfold to form cell-surface heavy chain homodimers (B272) and induce pro-inflammatory responses that may lead to SpA pathogenesis. The presence of B272 can be detected on leukocytes of HLA-B27+ Ankylosing spondylitis (AS) patients and HLA-B27 transgenic rats. We characterized a novel B272–specific monoclonal antibody to study its therapeutic use in HLA-B27 associated disorders. Methods The monoclonal HD5 antibody was selected from a phage library to target cell-surface B272 homodimers and characterized for affinity, specificity and ligand binding. The immune modulating effect of HD5 was tested in HLA-B27 transgenic rats. Onset and progression of disease profiles were monitored during therapy. Cell-surface B272 and expansion of pro-inflammatory cells from blood, spleen and draining lymph nodes were assessed by flow cytometry. Results HD5 bound B272 with high specificity and affinity (Kd = 0.32 nM). HD5 blocked cell-surface interaction of B272 with immune regulatory receptors KIR3DL2, LILRB2 and Pirb. In addition, HD5 modulated the production of TNF from CD4+ T-cells by limiting B272 interactions in vitro. In an HLA-B27 transgenic rat model repetitive dosing of HD5 reduced the expansion of pro-inflammatory CD4+ T-cells, and decreased the levels of soluble TNF and number of cell-surface B272 molecules. Conclusion HD5 predominantly inhibits early TNF production and expansion of pro-inflammatory CD4+ T-cells in HLA-B27 transgenic rats. Monoclonal antibodies targeting cell-surface B272 propose a new concept for the modulation of inflammatory responses in HLA-B27 related disorders. PMID:26125554

Morphological dependency of cutaneous blood flow and sweating during compensable heat stress when heat-loss requirements are matched across participants.

PubMed

Notley, Sean R; Park, Joonhee; Tagami, Kyoko; Ohnishi, Norikazu; Taylor, Nigel A S

2016-07-01

Human heat loss is thought, in part, to be morphologically related. It was therefore hypothesized that when heat-loss requirements and body temperatures were matched, that the mass-specific surface area alone could significantly explain both cutaneous vascular and sudomotor responses during compensable exercise. These thermoeffector responses were examined in 36 men with widely varying mass-specific surface areas (range, 232.3-292.7 cm(2)/kg), but of similar age, aerobic fitness, and adiposity. Subjects completed two trials under compensable conditions (28.1°C, 36.8% relative humidity), each involving rest (20 min) and steady-state cycling (45 min) at two matched metabolic heat-production rates (light, ∼135 W/m(2); moderate, ∼200 W/m(2)). Following equivalent mean body temperature changes, forearm blood flow and vascular conductance (r = 0.63 and r = 0.65) shared significant, positive associations with the mass-specific surface area during light work (P < 0.05), explaining ∼45% of the vasomotor variation. Conversely, during light and moderate work, whole body sweat rate, as well as local sweat rate and sudomotor sensitivity at three of four measured sites, revealed moderate, negative relationships with the mass-specific surface area (correlation coefficient range -0.37 to -0.73, P < 0.05). Moreover, those relationships could uniquely account for between 10 and 53% of those sweating responses (P < 0.05). Therefore, both thermoeffector responses displayed a significant morphological dependency in the presence of equivalent thermoafferent drive. Indeed, up to half of the interindividual variation in these effector responses could now be explained through morphological differences and the first principles governing heat transfer. Copyright © 2016 the American Physiological Society.

Morphological dependency of cutaneous blood flow and sweating during compensable heat stress when heat-loss requirements are matched across participants

PubMed Central

Notley, Sean R.; Park, Joonhee; Tagami, Kyoko; Ohnishi, Norikazu

2016-01-01

Human heat loss is thought, in part, to be morphologically related. It was therefore hypothesized that when heat-loss requirements and body temperatures were matched, that the mass-specific surface area alone could significantly explain both cutaneous vascular and sudomotor responses during compensable exercise. These thermoeffector responses were examined in 36 men with widely varying mass-specific surface areas (range, 232.3-292.7 cm2/kg), but of similar age, aerobic fitness, and adiposity. Subjects completed two trials under compensable conditions (28.1°C, 36.8% relative humidity), each involving rest (20 min) and steady-state cycling (45 min) at two matched metabolic heat-production rates (light, ∼135 W/m2; moderate, ∼200 W/m2). Following equivalent mean body temperature changes, forearm blood flow and vascular conductance (r = 0.63 and r = 0.65) shared significant, positive associations with the mass-specific surface area during light work (P < 0.05), explaining ∼45% of the vasomotor variation. Conversely, during light and moderate work, whole body sweat rate, as well as local sweat rate and sudomotor sensitivity at three of four measured sites, revealed moderate, negative relationships with the mass-specific surface area (correlation coefficient range −0.37 to −0.73, P < 0.05). Moreover, those relationships could uniquely account for between 10 and 53% of those sweating responses (P < 0.05). Therefore, both thermoeffector responses displayed a significant morphological dependency in the presence of equivalent thermoafferent drive. Indeed, up to half of the interindividual variation in these effector responses could now be explained through morphological differences and the first principles governing heat transfer. PMID:27125845

D-isoascorbyl palmitate: lipase-catalyzed synthesis, structural characterization and process optimization using response surface methodology.

PubMed

Sun, Wen-Jing; Zhao, Hong-Xia; Cui, Feng-Jie; Li, Yun-Hong; Yu, Si-Lian; Zhou, Qiang; Qian, Jing-Ya; Dong, Ying

2013-07-08

Isoascorbic acid is a stereoisomer of L-ascorbic acid, and widely used as a food antioxidant. However, its highly hydrophilic behavior prevents its application in cosmetics or fats and oils-based foods. To overcome this problem, D-isoascorbyl palmitate was synthesized in the present study for improving the isoascorbic acid's oil solubility with an immobilized lipase in organic media. The structural information of synthesized product was clarified using LC-ESI-MS, FT-IR, 1H and 13C NMR analysis, and process parameters for high yield of D-isoascorbyl palmitate were optimized by using One-factor-at-a-time experiments and response surface methodology (RSM). The synthesized product had the purity of 95% and its structural characteristics were confirmed as isoascorbyl palmitate by LC-ESI-MS, FT-IR, 1H, and 13C NMR analysis. Results from "one-factor-at-a-time" experiments indicated that the enzyme load, reaction temperature and D-isoascorbic-to-palmitic acid molar ratio had a significant effect on the D-isoascorbyl palmitate conversion rate. 95.32% of conversion rate was obtained by using response surface methodology (RSM) under the the optimized condition: enzyme load of 20% (w/w), reaction temperature of 53°C and D- isoascorbic-to-palmitic acid molar ratio of 1:4 when the reaction parameters were set as: acetone 20 mL, 40 g/L of molecular sieves content, 200 rpm speed for 24-h reaction time. The findings of this study can become a reference for developing industrial processes for the preparation of isoascorbic acid ester, which might be used in food additives, cosmetic formulations and for the synthesis of other isoascorbic acid derivatives.

D-isoascorbyl palmitate: lipase-catalyzed synthesis, structural characterization and process optimization using response surface methodology

PubMed Central

2013-01-01

Background Isoascorbic acid is a stereoisomer of L-ascorbic acid, and widely used as a food antioxidant. However, its highly hydrophilic behavior prevents its application in cosmetics or fats and oils-based foods. To overcome this problem, D-isoascorbyl palmitate was synthesized in the present study for improving the isoascorbic acid’s oil solubility with an immobilized lipase in organic media. The structural information of synthesized product was clarified using LC-ESI-MS, FT-IR, 1H and 13C NMR analysis, and process parameters for high yield of D-isoascorbyl palmitate were optimized by using One–factor-at-a-time experiments and response surface methodology (RSM). Results The synthesized product had the purity of 95% and its structural characteristics were confirmed as isoascorbyl palmitate by LC-ESI-MS, FT-IR, 1H, and 13C NMR analysis. Results from “one–factor-at-a-time” experiments indicated that the enzyme load, reaction temperature and D-isoascorbic-to-palmitic acid molar ratio had a significant effect on the D-isoascorbyl palmitate conversion rate. 95.32% of conversion rate was obtained by using response surface methodology (RSM) under the the optimized condition: enzyme load of 20% (w/w), reaction temperature of 53°C and D- isoascorbic-to-palmitic acid molar ratio of 1:4 when the reaction parameters were set as: acetone 20 mL, 40 g/L of molecular sieves content, 200 rpm speed for 24-h reaction time. Conclusion The findings of this study can become a reference for developing industrial processes for the preparation of isoascorbic acid ester, which might be used in food additives, cosmetic formulations and for the synthesis of other isoascorbic acid derivatives. PMID:23835418

Surface-associated flagellum formation and swarming differentiation in Bacillus subtilis are controlled by the ifm locus.

PubMed

Senesi, Sonia; Ghelardi, Emilia; Celandroni, Francesco; Salvetti, Sara; Parisio, Eva; Galizzi, Alessandro

2004-02-01

Knowledge of the highly regulated processes governing the production of flagella in Bacillus subtilis is the result of several observations obtained from growing this microorganism in liquid cultures. No information is available regarding the regulation of flagellar formation in B. subtilis in response to contact with a solid surface. One of the best-characterized responses of flagellated eubacteria to surfaces is swarming motility, a coordinate cell differentiation process that allows collective movement of bacteria over solid substrates. This study describes the swarming ability of a B. subtilis hypermotile mutant harboring a mutation in the ifm locus that has long been known to affect the degree of flagellation and motility in liquid media. On solid media, the mutant produces elongated and hyperflagellated cells displaying a 10-fold increase in extracellular flagellin. In contrast to the mutant, the parental strain, as well as other laboratory strains carrying a wild-type ifm locus, fails to activate a swarm response. Furthermore, it stops to produce flagella when transferred from liquid to solid medium. Evidence is provided that the absence of flagella is due to the lack of flagellin gene expression. However, restoration of flagellin synthesis in cells overexpressing sigma(D) or carrying a deletion of flgM does not recover the ability to assemble flagella. Thus, the ifm gene plays a determinantal role in the ability of B. subtilis to contact with solid surfaces.

Optimization of medium components and physicochemical parameters to simultaneously enhance microbial growth and production of lypolitic enzymes by Stenotrophomonas sp.

PubMed

Mazzucotelli, Cintia Anabela; Agüero, María Victoria; Del Rosario Moreira, María; Ansorena, María Roberta

2016-05-01

The optimization of lipase and esterase production (LP and EP) and bacterial growth (BG) of a Stenotrophomonas sp. strain was developed. For this purpose, the effect of five different medium components and three physicochemical parameters were evaluated using a Plackett-Burman statistical design. Among eight variables, stirring speed, pH, and peptone concentration were found to be the most effective factors on the three responses under evaluation. An optimization study applying Box-Behnken response surface methodology was used to study the interactive effects of the three selected variables on LP/EP and microorganism growth. Predicted models were found to be significant with high regression coefficients (90%-99%). By using the desirability function approach, the optimum condition applying simultaneous optimization of the three responses under study resulted to be: stirring speed of 100 rpm, pH of 7.5, and a peptone concentration of 10 g/L, with a desirability value of 0.977. Under these optimal conditions, it is possible to achieve in the optimized medium a 15-fold increase in esterase productivity, a 117-fold increase in lipase production, and a 9-log CFU/mL increase in BG, compared with the basal medium without agitation. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

From UV to Near-Infrared Light-Responsive Metal-Organic Framework Composites: Plasmon and Upconversion Enhanced Photocatalysis.

PubMed

Li, Dandan; Yu, Shu-Hong; Jiang, Hai-Long

2018-05-15

The exploitation of photocatalysts that harvest solar spectrum as broad as possible remains a high-priority target yet grand challenge. In this work, for the first time, metal-organic framework (MOF) composites are rationally fabricated to achieve broadband spectral response from UV to near-infrared (NIR) region. In the core-shell structured upconversion nanoparticles (UCNPs)-Pt@MOF/Au composites, the MOF is responsive to UV and a bit visible light, the plasmonic Au nanoparticles (NPs) accept visible light, whereas the UCNPs absorb NIR light to emit UV and visible light that are harvested by the MOF and Au once again. Moreover, the MOF not only facilitates the generation of "bare and clean" Au NPs on its surface and realizes the spatial separation for the Au and Pt NPs, but also provides necessary access for catalytic substrates/products to Pt active sites. As a result, the optimized composite exhibits excellent photocatalytic hydrogen production activity (280 µmol g -1 h -1 ) under simulated solar light, and the involved mechanism of photocatalytic H 2 production under UV, visible, and NIR irradiation is elucidated. Reportedly, this is an extremely rare study on photocatalytic H 2 production by light harvesting in all UV, visible, and NIR regions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of local anesthetics upon human polymorphonuclear leukocyte function in vitro. Reduction of lysosomal enzyme release and superoxide anion production

PubMed Central

1977-01-01

Cationic local anesthetics have been reported to influence cellular responses to surface stimuli by interfering with the function of microtubules and microfilaments. Since unimpaired microtubule and microfilament functions are required by human polymorphonuclear leukocytes in order to respond normally to surface stimulation, we have studied effects of the local anesthetic, tetracaine on the function and morphology of these cells in vitro. Tetracaine (0.25--1.0 mM) significantly reduced extracellular release of the lysosomal enzymes, beta-glucuronidase and lysozyme from polymorphonuclear leukocytes exposed to serum-treated zymosan (a particulate stimulus), zymosan- treated serum (a soluble stimulus), and to the surface-active lectin, concanavalin A. Tetracaine also significantly reduced superoixde anion production (superoxide dismutase-inhibitable cytochrome c reduction) by these cells. Tetrancaine was not cytotoxic and its effects could be reversed completely by washing cells once with buffer. Electron microscope examination of tetracaine-treated cells revealed marked alterations of surface membranes. Microtubules and microfilaments appeared normal in "resting" polymorphonuclear leukocytes, but the increase in microtubules normally observed in stimulated cells was not seen after tetracaine treatment. These results suggest that tetracaine interferes with those interactions between immune reactants and the polymorphonuclear leukocyte cell surface which provoke exocytosis and increased oxidative metabolism. PMID:195003

Medium optimization for the production of recombinant nattokinase by Bacillus subtilis using response surface methodology.

PubMed

Chen, Po Ting; Chiang, Chung-Jen; Chao, Yun-Peng

2007-01-01

Nattokinase is a potent fibrinolytic enzyme with the potential for fighting cardiovascular diseases. Most recently, a new Bacillus subtilis/Escherichia coli (B. subtilis/E. coli) shuttle vector has been developed to achieve stable production of recombinant nattokinase in B. subtilis (Chen; et al. 2007, 23, 808-813). With this developed B. subtilis strain, the design of an optimum but cost-effective medium for high-level production of recombinant nattokinase was attempted by using response surface methodology. On the basis of the Plackett-Burman design, three critical medium components were selected. Subsequently, the optimum combination of selected factors was investigated by the Box-Behnken design. As a result, it gave the predicted maximum production of recombinant nattokinase with 71 500 CU/mL for shake-flask cultures when the concentrations of soybean hydrolysate, potassium phosphate, and calcium chloride in medium were at 6.100, 0.415, and 0.015%, respectively. This was further verified by a duplicated experiment. Moreover, the production scheme based on the optimum medium was scaled up in a fermenter. The batch fermentation of 3 L was carried out by controlling the condition at 37 degrees C and dissolved oxygen reaching 20% of air saturation level while the fermentation pH was initially set at 8.5. Without the need for controlling the broth pH, recombinant nattokinase production with a yield of 77 400 CU/mL (corresponding to 560 mg/L) could be obtained in the culture broth within 24 h. In particular, the recombinant B. subtilis strain was found fully stable at the end of fermentation when grown on the optimum medium. Overall, it indicates the success of this experimental design approach in formulating a simple and cost-effective medium, which provides the developed strain with sufficient nutrient supplements for stable and high-level production of recombinant nattokinase in a fermenter.

Analysis of the tenderisation of jumbo squid (Dosidicus gigas) meat by ultrasonic treatment using response surface methodology.

PubMed

Hu, Yaqin; Yu, Hiaxia; Dong, Kaicheng; Yang, Shuibing; Ye, Xingqian; Chen, Shiguo

2014-10-01

Due to its unique structure, jumbo squid (Dosidicus gigas) meat is sensitive to heat treatment, which makes the traditional squid products taste tough and hard. This study aimed to tenderise jumbo squid meat through ultrasonic treatment. Response surface methodology (RSM) was used to predict the tenderising effect of various treatment conditions. According to the results of RSM, the optimal conditions appeared to be a power of 186.9 W, a frequency of 25.6 kHz, and a time of 30.8 min, and the predicted values of flexibility and firmness under these optimal conditions were 2.40 mm and 435.1 g, respectively. Protein degradation and a broken muscle fibre structure were observed through histological assay and SDS-PAGE, which suggests a satisfactory tenderisation effect. Copyright © 2014. Published by Elsevier Ltd.

Response of two semiarid grasslands to a second fire application

Treesearch

Carleton S. White; Rosemary L. Pendleton; Burton K. Pendleton

2006-01-01

Prescribed fire was used in two semiarid grasslands to reduce shrub cover, promote grass production, and reduce erosional loss that represents a potential non­point-source of sediment to degrade water quality. This study measured transported soil sediment, dynamics in soil surface microtopography, cover of the woody shrub, grass, and bare ground cover classes, and soil...

Activation of human B cells by phosphorothioate oligodeoxynucleotides.

PubMed Central

Liang, H; Nishioka, Y; Reich, C F; Pisetsky, D S; Lipsky, P E

1996-01-01

To investigate the potential of DNA to elicit immune responses in man, we examined the capacity of a variety of oligodeoxynucleotides (ODNs) to stimulate highly purified T cell-depleted human peripheral blood B cells. Among 47 ODNs of various sequences tested, 12 phosphorothioate oligodeoxynucleotides (sODNs) induced marked B cell proliferation and Ig production. IL-2 augmented both proliferation and production of IgM, IgG, and IgA, as well as IgM anti-DNA antibodies, but was not necessary for B cell stimulation. Similarly, T cells enhanced stimulation, but were not necessary for B cell activation. After stimulation with the active sODNs, more than 95% of B cells expressed CD25 and CD86. In addition, B cells stimulated with sODNs expressed all six of the major immunoglobulin VH gene families. These results indicate that the human B cell response to sODN is polyclonal. Active sODN coupled to Sepharose beads stimulated B cells as effectively as the free sODN, suggesting that stimulation resulted from engagement of surface receptors. These data indicate that sODNs can directly induce polyclonal activation of human B cells in a T cell-independent manner by engaging as yet unknown B cell surface receptors. PMID:8787674

Human Diversity in a Cell Surface Receptor that Inhibits Autophagy.

PubMed

Chaudhary, Anu; Leite, Mara; Kulasekara, Bridget R; Altura, Melissa A; Ogahara, Cassandra; Weiss, Eli; Fu, Wenqing; Blanc, Marie-Pierre; O'Keeffe, Michael; Terhorst, Cox; Akey, Joshua M; Miller, Samuel I

2016-07-25

Mutations in genes encoding autophagy proteins have been associated with human autoimmune diseases, suggesting that diversity in autophagy responses could be associated with disease susceptibility or severity. A cellular genome-wide association study (GWAS) screen was performed to explore normal human diversity in responses to rapamycin, a microbial product that induces autophagy. Cells from several human populations demonstrated variability in expression of a cell surface receptor, CD244 (SlamF4, 2B4), that correlated with changes in rapamycin-induced autophagy. High expression of CD244 and receptor activation with its endogenous ligand CD48 inhibited starvation- and rapamycin-induced autophagy by promoting association of CD244 with the autophagy complex proteins Vps34 and Beclin-1. The association of CD244 with this complex reduced Vps34 lipid kinase activity. Lack of CD244 is associated with auto-antibody production in mice, and lower expression of human CD244 has previously been implicated in severity of human rheumatoid arthritis and systemic lupus erythematosus, indicating that increased autophagy as a result of low levels of CD244 may alter disease outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of the acceptance of prebiotic beverage made from cashew nut kernels and passion fruit juice.

PubMed

Rebouças, Marina Cabral; Rodrigues, Maria do Carmo Passos; Afonso, Marcos Rodrigues Amorim

2014-07-01

The aim of this research was to develop a prebiotic beverage from a hydrosoluble extract of broken cashew nut kernels and passion fruit juice using response surface methodology in order to optimize acceptance of its sensory attributes. A 2(2) central composite rotatable design was used, which produced 9 formulations, which were then evaluated using different concentrations of hydrosoluble cashew nut kernel, passion fruit juice, oligofructose, and 3% sugar. The use of response surface methodology to interpret the sensory data made it possible to obtain a formulation with satisfactory acceptance which met the criteria of bifidogenic action and use of hydrosoluble cashew nut kernels by using 14% oligofructose and 33% passion fruit juice. As a result of this study, it was possible to obtain a new functional prebiotic product, which combined the nutritional and functional properties of cashew nut kernels and oligofructose with the sensory properties of passion fruit juice in a beverage with satisfactory sensory acceptance. This new product emerges as a new alternative for the industrial processing of broken cashew nut kernels, which have very low market value, enabling this sector to increase its profits. © 2014 Institute of Food Technologists®

Psoriasin, a novel anti-Candida albicans adhesin.

PubMed

Brauner, Annelie; Alvendal, Cathrin; Chromek, Milan; Stopsack, Konrad H; Ehrström, Sophia; Schröder, Jens M; Bohm-Starke, Nina

2018-05-07

Candida albicans belongs to the normal microbial flora on epithelial surfaces of humans. However, under certain, still not fully understood conditions, it can become pathogenic and cause a spectrum of diseases, from local infections to life-threatening septicemia. We investigated a panel of antimicrobial proteins and peptides (AMPs), potentially involved in mucosal immunity against this pathogen. Out of six studied AMPs, psoriasin was most up-regulated during a mucosal infection, an acute episode of recurrent Candida vulvovaginitis, although candidacidal activity has not been demonstrated. We here show that psoriasin binds to β-glucan, a basic component of the C. albicans cell wall, and thereby inhibits adhesion of the pathogen to surfaces and increases IL-8 production by mucosal epithelial cells. In conclusion, we show a novel mechanism of action of psoriasin. By inhibiting C. albicans adhesion and by enhancing cytokine production, psoriasin contributes to the immune response against C. albicans. The antimicrobial peptide psoriasin is highly up-regulated during a local mucosal infection, Candida albicans vulvovaginitis. Psoriasin binds to β-glucan in the Candida albicans cell wall and thereby inhibits adhesion of the pathogen. Binding of psoriasin to Candida albicans induces an immune response by mucosal epithelial cells.

Improvement of biodiesel production by lipozyme TL IM-catalyzed methanolysis using response surface methodology and acyl migration enhancer.

PubMed

Wang, Y; Wu, H; Zong, M H

2008-10-01

The process of biodiesel production from corn oil catalyzed by lipozyme TL IM, an inexpensive 1,3-position specific lipase from Thermomyces lanuginosus was optimized by response surface methodology (RSM) and a central composite rotatable design (CCRD) was used to study the effects of enzyme dosage, ratio of t-butanol to oil (v/v) and ratio of methanol to oil (mol/mol) on the methyl esters (ME) yield of the methanolysis. The optimum combinations for the reaction were 25.9U/goil of enzyme, 0.58 volume ratio of t-butanol to oil and 0.5, 0.5, 2.8 molar equivalent of methanol to oil added at the reaction time of 0, 2, and 4h, respectively, by which a ME yield of 85.6%, which was very close to the predicted value of 85.0%, could be obtained after reaction for 12h. Waste oil was found to be more suitable feedstock, and could give 93.7% ME yield under the optimum conditions described above. Adding triethylamine (TEA), an acyl migration enhancer, could efficiently improve the ME yield of the methanolysis of corn oil, giving a ME yield of 92.0%.

Case Studies of Rock Reinforcement Components and Systems Testing

NASA Astrophysics Data System (ADS)

Thompson, A. G.; Villaescusa, E.

2014-09-01

Rock reinforcement is widely used in tunnels and surface and underground mines. A large number of proprietary products are available in various configurations of components. While the mechanical properties of the primary element are available from product brochures, the associated component properties may vary widely and adversely influence the overall performance of the system. Field pull out tests are most commonly used to measure the system response in the toe anchor region. However, the response of the collar region is less commonly considered but may be more important. Several case studies are described in which various components and systems of rock bolts and cable bolts have been subjected to static loading in the laboratory and in the field. The results generally demonstrate the importance of considering the properties of all the components and not simply those of the primary element. In some cases, the internal fixtures have strengths much less than the elements. Often it has also been found that the fixture at the collar has significantly less strength than the element and this will result in complete loss of function in restraining surface support hardware, such as plates, mesh and reinforced shotcrete.

An oil spill decision matrix in response to surface spills of various bitumen blends.

PubMed

King, Thomas L; Robinson, Brian; Cui, Fangda; Boufadel, Michel; Lee, Kenneth; Clyburne, Jason A C

2017-07-19

Canada's production, transport, and sale of diluted bitumen (dilbit) products are expected to increase by a million barrels per day over the next decade. The anticipated growth in oil production and transport increases the risk of oil spills in aquatic areas and places greater demands on oil spill capabilities to respond to spills, which have raised stakeholder concerns. Current oil spill models only predict the transport of bitumen blends that are used in contingency plans and oil spill response strategies, rather than changes in the oil's physical properties that are relevant to spill response. We conducted weathering studies of five oil products (two conventional oils and three bitumen blends) in the Department of Fisheries and Oceans' flume tank. We also considered two initial oil slick thicknesses, 4.0 mm and 7.0 mm. We found that there is a major difference in the time evolution of oil properties (density and viscosity), raising doubts on weathering models that do not consider the thickness of oil. We also developed empirical expressions for the evolution of the density and viscosity of these oil products. The findings from the 4.0 mm results were incorporated with data from the literature to provide an update on the factors to consider during the decision making for spills of diluted bitumen products. The matrix indicated that most response options, including chemical dispersants, work much more effectively within 48 hours of the initiation of weathering. After this window of opportunity closes, natural attenuation or in situ burning is the only option remaining, but containment of oil is a limiting factor for in situ burning.

Response of Antarctic cryoconite microbial communities to light.

PubMed

Bagshaw, Elizabeth A; Wadham, Jemma L; Tranter, Martyn; Perkins, Rupert; Morgan, Alistair; Williamson, Christopher J; Fountain, Andrew G; Fitzsimons, Sean; Dubnick, Ashley

2016-06-01

Microbial communities on polar glacier surfaces are found dispersed on the ice surface, or concentrated in cryoconite holes and cryolakes, which are accumulations of debris covered by a layer of ice for some or all of the year. The ice lid limits the penetration of photosynthetically available radiation (PAR) to the sediment layer, since the ice attenuates up to 99% of incoming radiation. This suite of field and laboratory experiments demonstrates that PAR is an important control on primary production in cryoconite and cryolake ecosystems. Increased light intensity increased efficiency of primary production in controlled laboratory incubations of debris from the surface of Joyce Glacier, McMurdo Dry Valleys, Antarctica. However, when light intensity was increased to levels near that received on the ice surface, without the protection of an ice lid, efficiency decreased and measurements of photophysiology showed that the communities suffered light stress. The communities are therefore well adapted to low light levels. Comparison with Arctic cryoconite communities, which are typically not covered by an ice lid for the majority of the ablation season, showed that these organisms were also stressed by high light, so they must employ strategies to protect against photodamage. © FEMS 2016.

Response of Antarctic cryoconite microbial communities to light

PubMed Central

Bagshaw, Elizabeth A.; Wadham, Jemma L.; Tranter, Martyn; Perkins, Rupert; Morgan, Alistair; Williamson, Christopher J.; Fountain, Andrew G.; Fitzsimons, Sean; Dubnick, Ashley

2016-01-01

Microbial communities on polar glacier surfaces are found dispersed on the ice surface, or concentrated in cryoconite holes and cryolakes, which are accumulations of debris covered by a layer of ice for some or all of the year. The ice lid limits the penetration of photosynthetically available radiation (PAR) to the sediment layer, since the ice attenuates up to 99% of incoming radiation. This suite of field and laboratory experiments demonstrates that PAR is an important control on primary production in cryoconite and cryolake ecosystems. Increased light intensity increased efficiency of primary production in controlled laboratory incubations of debris from the surface of Joyce Glacier, McMurdo Dry Valleys, Antarctica. However, when light intensity was increased to levels near that received on the ice surface, without the protection of an ice lid, efficiency decreased and measurements of photophysiology showed that the communities suffered light stress. The communities are therefore well adapted to low light levels. Comparison with Arctic cryoconite communities, which are typically not covered by an ice lid for the majority of the ablation season, showed that these organisms were also stressed by high light, so they must employ strategies to protect against photodamage. PMID:27095815

Optimization of tannase production by a novel Klebsiella pneumoniae KP715242 using central composite design.

PubMed

Kumar, Mukesh; Rana, Shiny; Beniwal, Vikas; Salar, Raj Kumar

2015-09-01

A novel tannase producing bacterial strain was isolated from rhizospheric soil of Acacia species and identified as Klebsiella pneumoniae KP715242. A 3.25-fold increase in tannase production was achieved upon optimization with central composite design using response surface methodology. Four variables namely pH, temperature, incubation period, and agitation speed were used to optimize significant correlation between the effects of these variables on tannase production. A second-order polynomial was fitted to data and validated by ANOVA. The results showed a complex relationship between variables and response given that all factors were significant and could explain 99.6% of the total variation. The maximum production was obtained at 5.2 pH, 34.97 °C temperature, 103.34 rpm agitation speed and 91.34 h of incubation time. The experimental values were in good agreement with the predicted ones and the models were highly significant with a correlation coefficient ( R 2 ) of 0.99 and a highly significant F-value of 319.37.

Production and characterization of rhamnolipids produced by Serratia rubidaea SNAU02 under solid-state fermentation and its application as biocontrol agent.

PubMed

Nalini, S; Parthasarathi, R

2014-12-01

The present study aimed at exploring mahua (Madhuca indica) oil cake as a novel substrate for the production of biosurfactant by Serratia rubidaea SNAU02 under solid-state fermentation (SSF). Response surface methodology showed followings as the optimal conditions for the production of biosurfactant: mahua oil cake 7.48 g, 2.5 ml inoculum size (1×10(8) cells/ml), and pH 7.22 and 31 °C temperature. The characterization of the biosurfactant by TLC, FT-IR and GC-MS revealed the presence of rhamnolipid. The presence of rhamnosyl transferase gene responsible for biosynthesis of rhamnolipid was identified. The strain SNAU02 exhibited antifungal activity and demonstrated no toxicity against the seeds of Brassica oleracea and Artemia salina employed as a bio-indicator. The present findings indicated the potential of mahua oil cake as suitable substrate for the production of rhamnolipids in SSF by S. rubidaea SNAU02 and application potential of the biosurfactant produced as biocontrol agent against plant pathogens. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methane Cycling in a Warming Wetland

NASA Astrophysics Data System (ADS)

Noyce, G. L.; Megonigal, P.; Rich, R.; Kirwan, M. L.; Herbert, E. R.

2017-12-01

Coastal wetlands are global hotspots of carbon (C) storage, but the future of these systems is uncertain. In June 2016, we initiated an in-situ, active, whole-ecosystem warming experiment in the Smithsonian's Global Change Research Wetland to quantify how warming and elevated CO2 affect the stability of coastal wetland soil C pools and contemporary rates of C sequestration. Transects are located in two plant communities, dominated by C3 sedges or C4 grasses. The experiment has a gradient design with air and soil warming treatments ranging from ambient to +5.1 °C and heated plots consistently maintain their target temperature year-round. In April 2017, an elevated CO2 treatment was crossed with temperature in the C3community. Ongoing measurements include soil elevation, C fluxes, porewater chemistry and redox potential, and above- and below-ground growth and biomass. In both years, warming increased methane (CH4) emissions (measured at 3-4 week intervals) from spring through fall at the C3 site, but had little effect on emissions from the C4 site. Winter (Dec-Mar) emissions showed no treatment effect. Stable isotope analysis of dissolved CH4 and DIC also indicated that warming had differing effects on CH4 pathways in the two vegetation communities. To better understand temperature effects on rates of CH4 production and oxidation, 1 m soil cores were collected from control areas of the marsh in summer 2017 and incubated at temperatures ranging from 4 °C to 35 °C. Warming increased CH4 production and oxidation rates in surface samples and oxidation rates in the rooting zone samples from both sites, but temperature responses in deep (1 m) soil samples were minimal. In the surface and rooting zone samples, production rates were also consistently higher in C3 soils compared to C4 soils, but, contrary to our expectations, the temperature response was stronger in the C4 soils. However, oxidation in C3 rooting zone samples did have a strong temperature response. The ratio of CO2:CH4 decreased with increasing temperature in surface samples from both sites, indicating that anaerobic respiration in surface soil may become increasingly methanogenic with warming. In contrast, the rooting zone and deep soil samples showed the opposite trend, again suggesting that the soil profile will not respond consistently to warming.

Chemical models of interstellar gas-grain processes. II - The effect of grain-catalysed methane on gas phase evolution

NASA Technical Reports Server (NTRS)

Brown, Paul D.; Charnley, S. B.

1991-01-01

The effects on gas phase chemistry which result from the continuous desorption of methane molecules from grain surfaces are studied. Significant and sustained enhancements in the abundances of several complex hydrocarbon molecules are found, in good agreement with their observed values in TMC-1. The overall agreement is, however, just as good for the case of zero CH4 desorption efficiency. It is thus impossible to determine from the models whether or not the grain-surface production of methane is responsible for the observed abundances of some hydrocarbon molecules.

Beyond imperviousness: A statistical approach to identifying functional differences between development morphologies on variable source area-type response in urbanized watersheds

NASA Astrophysics Data System (ADS)

Lim, T. C.

2016-12-01

Empirical evidence has shown linkages between urbanization, hydrological regime change, and degradation of water quality and aquatic habitat. Percent imperviousness, has long been suggested as the dominant source of these negative changes. However, recent research identifying alternative pathways of runoff production at the watershed scale have called into question percent impervious surface area's primacy in urban runoff production compared to other aspects of urbanization including change in vegetative cover, imported water and water leakages, and the presence of drainage infrastructure. In this research I show how a robust statistical methodology can detect evidence of variable source area (VSA)-type hydrologic response associated with incremental hydraulic connectivity in watersheds. I then use logistic regression to explore how evidence of VSA-type response relates to the physical and meterological characteristics of the watershed. I find that impervious surface area is highly correlated with development, but does not add significant explanatory power beyond percent developed in predicting VSA-type response. Other aspects of development morphology, including percent developed open space and type of drainage infrastructure also do not add to the explanatory power of undeveloped land in predicting VSA-type response. Within only developed areas, the effect of developed open space was found to be more similar to that of total impervious area than to undeveloped land. These findings were consistent when tested across a national cross-section of urbanized watersheds, a higher resolution dataset of Baltimore Metropolitan Area watersheds, and a subsample of watersheds confirmed not to be served by combined sewer systems. These findings suggest that land development policies that focus on lot coverage should be revisited, and more focus should be placed on preserving native vegetation and soil conditions alongside development.

Eddy-driven nutrient transport and associated upper-ocean primary production along the Kuroshio

NASA Astrophysics Data System (ADS)

Uchiyama, Yusuke; Suzue, Yota; Yamazaki, Hidekatsu

2017-06-01

The Kuroshio is one of the most energetic western boundary currents accompanied by vigorous eddy activity both on mesoscale and submesoscale, which affects biogeochemical processes in the upper ocean. We examine the primary production around the Kuroshio off Japan using a climatological ocean modeling based on the Regional Oceanic Modeling System (ROMS) coupled with a nitrogen-based nutrient, phytoplankton and zooplankton, and detritus (NPZD) biogeochemical model in a submesoscale eddy-permitting configuration. The model indicates significant differences of the biogeochemical responses to eddy activities in the Kuroshio Region (KR) and Kuroshio Extension Region (KE). In the KR, persisting cyclonic eddies developed between the Kuroshio and coastline are responsible for upwelling-induced eutrophication. However, the eddy-induced vertical nutrient flux counteracts and promotes pronounced southward and downward diapycnal nutrient transport from the mixed-layer down beneath the main body of the Kuroshio, which suppresses the near-surface productivity. In contrast, the KE has a 23.5% higher productivity than the KR, even at comparable eddy intensity. Upward nutrient transport prevails near the surface due to predominant cyclonic eddies, particularly to the north of the KE, where the downward transport barely occurs, except at depths deeper than 400 m and to a much smaller degree than in the KR. The eddy energy conversion analysis reveals that the combination of shear instability around the mainstream of the Kuroshio with prominent baroclinic instability near the Kuroshio front is essential for the generation of eddies in the KR, leading to the increase of the eddy-induced vertical nitrate transport around the Kuroshio.

Optimization of supercritical carbon dioxide treatment for the inactivation of the natural microbial flora in cubed cooked ham.

PubMed

Ferrentino, Giovanna; Balzan, Sara; Spilimbergo, Sara

2013-02-15

This study aims to investigate the effects of supercritical carbon dioxide (SC-CO₂) treatment on the inactivation of the natural microbial flora in cubed cooked ham. Response surface methodology with a central composite design was applied to determine the optimal process conditions and investigate the effect of three independent variables (pressure, temperature and treatment time). Additionally, analyses of texture, pH and color together with a storage study of the product were performed to determine its microbial and qualitative stability. Response surface analysis revealed that 12 MPa, 50 °C, 5 min were the optimal conditions to obtain about 3.0, 1.6, and 2.5 Log(CFU/g) reductions of mesophilic aerobic bacteria, psychrophilic bacteria and lactic acid bacteria respectively. Inactivation to undetectable levels of yeasts and molds and coliforms was also obtained. A storage study of 30 days at 4 °C was carried out on the treated product (12 MPa, 50 °C, 5 min) monitoring microbial growth, pH, texture, and color parameters (L*, a*, b* and ΔE). Microbial loads slightly increased and after 30 days of storage reached the same levels detected in the fresh product. Color parameters (L*, a*, b*) showed slight variations while pH and texture did not change significantly. On the basis of the results obtained, SC-CO₂ can be considered a promising technique to microbiologically stabilize cubed cooked ham and, in general, cut/sliced meat products without affecting its quality attributes. Copyright © 2012 Elsevier B.V. All rights reserved.

Photosynthesis sensitivity to climate change in land surface models

NASA Astrophysics Data System (ADS)

Manrique-Sunen, Andrea; Black, Emily; Verhoef, Anne; Balsamo, Gianpaolo

2016-04-01

Accurate representation of vegetation processes within land surface models is key to reproducing surface carbon, water and energy fluxes. Photosynthesis determines the amount of CO2 fixated by plants as well as the water lost in transpiration through the stomata. Photosynthesis is calculated in land surface models using empirical equations based on plant physiological research. It is assumed that CO2 assimilation is either CO2 -limited, radiation -limited ; and in some models export-limited (the speed at which the products of photosynthesis are used by the plant) . Increased levels of atmospheric CO2 concentration tend to enhance photosynthetic activity, but the effectiveness of this fertilization effect is regulated by environmental conditions and the limiting factor in the photosynthesis reaction. The photosynthesis schemes at the 'leaf level' used by land surface models JULES and CTESSEL have been evaluated against field photosynthesis observations. Also, the response of photosynthesis to radiation, atmospheric CO2 and temperature has been analysed for each model, as this is key to understanding the vegetation response that climate models using these schemes are able to reproduce. Particular emphasis is put on the limiting factor as conditions vary. It is found that while at present day CO2 concentrations export-limitation is only relevant at low temperatures, as CO2 levels rise it becomes an increasingly important restriction on photosynthesis.

Pneumococcal surface protein A (PspA) is effective at eliciting T cell-mediated responses during invasive pneumococcal disease in adults

PubMed Central

Baril, L; Dietemann, J; Essevaz-Roulet, M; Béniguel, L; Coan, P; Briles, D E; Guy, B; Cozon, G

2006-01-01

Humoral immune response is essential for protection against invasive pneumococcal disease and this property is the basis of the polysaccharide-based anti-pneumococcal vaccines. Pneumococcal surface protein A (PspA), a cell-wall-associated surface protein, is a promising component for the next generation of pneumococcal vaccines. This PspA antigen has been shown to stimulate an antibody-based immunity. In the present study, we evaluated the capacity of PspA to stimulate CD4+ T cells which are needed for the correct development of a B cell based immune response in humans. Cellular immunity to PspA was evaluated by whole-blood culture with different pneumococcal antigens, followed by flow cytometric detection of activated CD4+CD25+ T cells. T cell-mediated immune responses to recombinant PspA proteins were assessed in acute-phase and convalescent blood from adults with invasive pneumococcal disease and in blood from healthy subjects. All cases had detectable antibodies against PspA on admission. We found that invasive pneumococcal disease induced transient T cell depletion but adaptive immune responses strengthened markedly during convalescence. The increased production of both interleukin (IL)-10 and interferon (IFN)-γ during convalescence suggests that these cytokines may be involved in modulating antibody-based immunity to pneumococcal disease. We demonstrated that PspA is efficient at eliciting T cell immune responses and antibodies to PspA. This study broadens the applicability of recombinant PspA as potent pneumococcal antigen for vaccination against S. pneumoniae. PMID:16879247

Surface-mediated molecular events in material-induced blood-plasma coagulation

NASA Astrophysics Data System (ADS)

Chatterjee, Kaushik

Coagulation and thrombosis persist as major impediments associated with the use of blood-contacting medical devices. We are investigating the molecular mechanism underlying material-induced blood-plasma coagulation focusing on the role of the surface as a step towards prospective development of improved hemocompatible biomaterials. A classic observation in hematology is that blood/blood-plasma in contact with clean glass surface clots faster than when in contact with many plastic surfaces. The traditional biochemical theory explaining the underlying molecular mechanism suggests that hydrophilic surfaces, like that of glass, are specific activators of the coagulation cascade because of the negatively-charged groups on the surface. Hydrophobic surfaces are poor procoagulants or essentially "benign" because they lack anionic groups. Further, these negatively-charged surfaces are believed to not only activate blood factor XII (FXII), the key protein in contact activation, but also play a cofactor role in the amplification and propagation reactions that ultimately lead to clot formation. In sharp contrast to the traditional theory, our investigations indicate a need for a paradigm shift in the proposed sequence of contact activation events to incorporate the role of protein adsorption at the material surfaces. These studies have lead to the central hypothesis for this work proposing that protein adsorption to hydrophobic surfaces attenuates the contact activation reactions so that poorly-adsorbent hydrophilic surfaces appear to be stronger procoagulants relative to hydrophobic surfaces. Our preliminary studies measuring the plasma coagulation response of activated FXII (FXIIa) on different model surfaces suggested that the material did not play a cofactor role in the processing of this enzyme dose through the coagulation pathway. Therefore, we focused our efforts on studying the mechanism of initial production of enzyme at the procoagulant surface. Calculations for the amounts of FXIIa generated at material surfaces in plasma using a mathematical model for measured coagulation responses indicate that the relative contributions of the individual pathways of enzyme generation are similar at both hydrophilic and hydrophobic surfaces, only the amounts of enzyme generated scale with surface energy and area of the activating surface. Further, from direct measurement of enzyme activation at test surfaces we observed that contact activation reactions are not specific to negatively-charged hydrophilic surfaces. Rather, the molecular interactions are attenuated at hydrophobic surfaces due to protein adsorption so that poorly-adsorbent hydrophilic surfaces exhibit an apparent specificity for contact activation reactions. Preliminary studies were preformed to assay the plasma coagulation response to low-fouling surfaces prepared by either grafting poly(ethylene glycol) chains or using zwitterions. Results indicate that poly(ethylene glycol)-modified surfaces are significantly weaker procoagulants than surfaces containing zwitterions underscoring a need to specifically evaluate the coagulation response despite similarities in observed protein adsorption to both surfaces. In summary, our studies demonstrate a need to incorporate protein-adsorption competition at procoagulant surfaces into the mechanism of contact activation to account for the observed moderation of FXII activation by blood proteins unrelated to the plasma coagulation cascade.

A study of diazonium couplings with aromatic nucleophiles both in solution and on a polymer surface

NASA Astrophysics Data System (ADS)

Chng, Shuyun; Parker, Emily M.; Griffiths, Jon-Paul; Moloney, Mark G.; Wu, Linda Y. L.

2017-04-01

Diazonium coupling is a technique finding wider application to materials and biological science, for hybridization and linking processes, and for the construction of responsive surface functionality. For this reason, detailed examination of solution and surface processes was warranted, and results of such a study are reported here. The modification of polystyrene surfaces was examined as a model, and the process compared to a solution mimic using N,N-dimethylaniline. It was confirmed that solution and solid surface reactions proceed in a similar manner in terms of the chemical functionality generated, but with lower chemical efficiency and reaction times slower for the latter, in a reaction which was pH dependent. The solution process was shown to give only the trans-azo para- coupled products. Whilst there are clear similarities between the solution and surface chemistry, the efficiency of coupling at a surface is not necessarily replicated in the chemical yield of the mimicking solution processes, but nonetheless provides an alternative to other Click-type surface modifications. It should not be assumed that such couplings occur with quantitative efficiency at the surface.

2D SnO2 Nanosheets: Synthesis, Characterization, Structures, and Excellent Sensing Performance to Ethylene Glycol

PubMed Central

Wan, Wenjin; Li, Yuehua; Ren, Xingping; Zhao, Yinping; Gao, Fan; Zhao, Heyun

2018-01-01

Two dimensional (2D)SnO2 nanosheets were synthesized by a substrate-free hydrothermal route using sodium stannate and sodium hydroxide in a mixed solvent of absolute ethanol and deionized water at a lower temperature of 130 °C. The characterization results of the morphology, microstructure, and surface properties of the as-prepared products demonstrated that SnO2 nanosheets with a tetragonal rutile structure, were composed of oriented SnO2 nanoparticles with a diameter of 6–12 nm. The X-ray diffraction (XRD) and high-resolution transmission electron microscope (FETEM) results demonstrated that the dominant exposed surface of the SnO2 nanoparticles was (101), but not (110). The growth and formation was supposed to follow the oriented attachment mechanism. The SnO2 nanosheets exhibited an excellent sensing response toward ethylene glycol at a lower optimal operating voltage of 3.4 V. The response to 400 ppm ethylene glycol reaches 395 at 3.4 V. Even under the low concentration of 5, 10, and 20 ppm, the sensor exhibited a high response of 6.9, 7.8, and 12.0 to ethylene glycol, respectively. The response of the SnO2 nanosheets exhibited a linear dependence on the ethylene glycol concentration from 5 to 1000 ppm. The excellent sensing performance was attributed to the present SnO2 nanoparticles with small size close to the Debye length, the larger specific surface, the high-energy exposed facets of the (101) surface, and the synergistic effects of the SnO2 nanoparticles of the nanosheets. PMID:29462938

Holocene paleoceanography of Bigo Bay, west Antarctic Peninsula: Connections between surface water productivity and nutrient utilization and its implication for surface-deep water mass exchange

NASA Astrophysics Data System (ADS)

Kim, Sunghan; Yoo, Kyu-Cheul; Lee, Jae Il; Khim, Boo-Keun; Bak, Young-Suk; Lee, Min Kyung; Lee, Jongmin; Domack, Eugene W.; Christ, Andrew J.; Yoon, Ho Il

2018-07-01

Paleoceanographic changes in response to Holocene climate variability in Bigo Bay, west Antarctic Peninsula (WAP) were reconstructed through geochemical, isotopic, sedimentological, and microfossil analysis. Core WAP13-GC47 is composed of 4 lithologic units. Unit 4 was deposited under ice shelf settings. Unit 3 represents the mid-Holocene open marine conditions. Unit 2 indicates lateral sediment transport by a glacier advance during the Neoglacial period. The chronological contrast between the timing of open marine conditions at core WAP13-GC47 (ca. 7060 cal. yr BP at 540 cm) and the ages of calcareous shell fragments (ca. 8500 cal. yr BP) in Unit 2b suggests sediment reworking during the Neoglacial period. Unit 1 was deposited during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Surface water productivity, represented by biogenic opal and total organic carbon (TOC) concentrations, increased and bulk δ15N (nitrate utilization) decreased during the warmer early to middle Holocene and the MWP. In contrast, surface water productivity decreased with increased bulk δ15N during the colder Neoglacial period and LIA in Bigo Bay. The nitrate utilization was enhanced during cold periods in association with strong surface water stratification resulting from increased sea ice meltwater discharge or proximity to an ice shelf calving front in Bigo Bay. Reduced nitrate utilization during warm periods is related to weak stratification induced by less sea ice meltwater input and stronger Circumpolar Deep Water influence.

Conjugate Analysis of Two-Dimensional Ablation and Pyrolysis in Rocket Nozzles

NASA Astrophysics Data System (ADS)

Cross, Peter G.

The development of a methodology and computational framework for performing conjugate analyses of transient, two-dimensional ablation of pyrolyzing materials in rocket nozzle applications is presented. This new engineering methodology comprehensively incorporates fluid-thermal-chemical processes relevant to nozzles and other high temperature components, making it possible, for the first time, to rigorously capture the strong interactions and interdependencies that exist between the reacting flowfield and the ablating material. By basing thermal protection system engineering more firmly on first principles, improved analysis accuracy can be achieved. The computational framework developed in this work couples a multi-species, reacting flow solver to a two-dimensional material response solver. New capabilities are added to the flow solver in order to be able to model unique aspects of the flow through solid rocket nozzles. The material response solver is also enhanced with new features that enable full modeling of pyrolyzing, anisotropic materials with a true two-dimensional treatment of the porous flow of the pyrolysis gases. Verification and validation studies demonstrating correct implementation of these new models in the flow and material response solvers are also presented. Five different treatments of the surface energy balance at the ablating wall, with increasing levels of fidelity, are investigated. The Integrated Equilibrium Surface Chemistry (IESC) treatment computes the surface energy balance and recession rate directly from the diffusive fluxes at the ablating wall, without making transport coefficient or unity Lewis number assumptions, or requiring pre-computed surface thermochemistry tables. This method provides the highest level of fidelity, and can inherently account for the effects that recession, wall temperature, blowing, and the presence of ablation product species in the boundary layer have on the flowfield and ablation response. Multiple decoupled and conjugate ablation analysis studies for the HIPPO nozzle test case are presented. Results from decoupled simulations show sensitivity to the wall temperature profile used within the flow solver, indicating the need for conjugate analyses. Conjugate simulations show that the thermal response of the nozzle is relatively insensitive to the choice of the surface energy balance treatment. However, the surface energy balance treatment is found to strongly affect the surface recession predictions. Out of all the methods considered, the IESC treatment produces surface recession predictions with the best agreement to experimental data. These results show that the increased fidelity provided by the proposed conjugate ablation modeling methodology produces improved analysis accuracy, as desired.

Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2.

PubMed

Friend, Andrew D; Lucht, Wolfgang; Rademacher, Tim T; Keribin, Rozenn; Betts, Richard; Cadule, Patricia; Ciais, Philippe; Clark, Douglas B; Dankers, Rutger; Falloon, Pete D; Ito, Akihiko; Kahana, Ron; Kleidon, Axel; Lomas, Mark R; Nishina, Kazuya; Ostberg, Sebastian; Pavlick, Ryan; Peylin, Philippe; Schaphoff, Sibyll; Vuichard, Nicolas; Warszawski, Lila; Wiltshire, Andy; Woodward, F Ian

2014-03-04

Future climate change and increasing atmospheric CO2 are expected to cause major changes in vegetation structure and function over large fractions of the global land surface. Seven global vegetation models are used to analyze possible responses to future climate simulated by a range of general circulation models run under all four representative concentration pathway scenarios of changing concentrations of greenhouse gases. All 110 simulations predict an increase in global vegetation carbon to 2100, but with substantial variation between vegetation models. For example, at 4 °C of global land surface warming (510-758 ppm of CO2), vegetation carbon increases by 52-477 Pg C (224 Pg C mean), mainly due to CO2 fertilization of photosynthesis. Simulations agree on large regional increases across much of the boreal forest, western Amazonia, central Africa, western China, and southeast Asia, with reductions across southwestern North America, central South America, southern Mediterranean areas, southwestern Africa, and southwestern Australia. Four vegetation models display discontinuities across 4 °C of warming, indicating global thresholds in the balance of positive and negative influences on productivity and biomass. In contrast to previous global vegetation model studies, we emphasize the importance of uncertainties in projected changes in carbon residence times. We find, when all seven models are considered for one representative concentration pathway × general circulation model combination, such uncertainties explain 30% more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151% for non-HYBRID4 models. A change in research priorities away from production and toward structural dynamics and demographic processes is recommended.

Optimisation and Characterisation of Lipase-Catalysed Synthesis of a Kojic Monooleate Ester in a Solvent-Free System by Response Surface Methodology.

PubMed

Jumbri, Khairulazhar; Al-Haniff Rozy, Mohd Fahruddin; Ashari, Siti Efliza; Mohamad, Rosfarizan; Basri, Mahiran; Fard Masoumi, Hamid Reza

2015-01-01

Kojic acid is widely used to inhibit the browning effect of tyrosinase in cosmetic and food industries. In this work, synthesis of kojic monooleate ester (KMO) was carried out using lipase-catalysed esterification of kojic acid and oleic acid in a solvent-free system. Response Surface Methodology (RSM) based on central composite rotatable design (CCRD) was used to optimise the main important reaction variables, such as enzyme amount, reaction temperature, substrate molar ratio, and reaction time along with immobilised lipase from Candida Antarctica (Novozym 435) as a biocatalyst. The RSM data indicated that the reaction temperature was less significant in comparison to other factors for the production of a KMO ester. By using this statistical analysis, a quadratic model was developed in order to correlate the preparation variable to the response (reaction yield). The optimum conditions for the enzymatic synthesis of KMO were as follows: an enzyme amount of 2.0 wt%, reaction temperature of 83.69°C, substrate molar ratio of 1:2.37 (mmole kojic acid:oleic acid) and a reaction time of 300.0 min. Under these conditions, the actual yield percentage obtained was 42.09%, which is comparably well with the maximum predicted value of 44.46%. Under the optimal conditions, Novozym 435 could be reused for 5 cycles for KMO production percentage yield of at least 40%. The results demonstrated that statistical analysis using RSM can be used efficiently to optimise the production of a KMO ester. Moreover, the optimum conditions obtained can be applied to scale-up the process and minimise the cost.

Optimisation and Characterisation of Lipase-Catalysed Synthesis of a Kojic Monooleate Ester in a Solvent-Free System by Response Surface Methodology

PubMed Central

Jumbri, Khairulazhar; Al-Haniff Rozy, Mohd Fahruddin; Ashari, Siti Efliza; Mohamad, Rosfarizan; Basri, Mahiran; Fard Masoumi, Hamid Reza

2015-01-01

Kojic acid is widely used to inhibit the browning effect of tyrosinase in cosmetic and food industries. In this work, synthesis of kojic monooleate ester (KMO) was carried out using lipase-catalysed esterification of kojic acid and oleic acid in a solvent-free system. Response Surface Methodology (RSM) based on central composite rotatable design (CCRD) was used to optimise the main important reaction variables, such as enzyme amount, reaction temperature, substrate molar ratio, and reaction time along with immobilised lipase from Candida Antarctica (Novozym 435) as a biocatalyst. The RSM data indicated that the reaction temperature was less significant in comparison to other factors for the production of a KMO ester. By using this statistical analysis, a quadratic model was developed in order to correlate the preparation variable to the response (reaction yield). The optimum conditions for the enzymatic synthesis of KMO were as follows: an enzyme amount of 2.0 wt%, reaction temperature of 83.69°C, substrate molar ratio of 1:2.37 (mmole kojic acid:oleic acid) and a reaction time of 300.0 min. Under these conditions, the actual yield percentage obtained was 42.09%, which is comparably well with the maximum predicted value of 44.46%. Under the optimal conditions, Novozym 435 could be reused for 5 cycles for KMO production percentage yield of at least 40%. The results demonstrated that statistical analysis using RSM can be used efficiently to optimise the production of a KMO ester. Moreover, the optimum conditions obtained can be applied to scale-up the process and minimise the cost. PMID:26657030

Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2

PubMed Central

Friend, Andrew D.; Lucht, Wolfgang; Rademacher, Tim T.; Keribin, Rozenn; Betts, Richard; Cadule, Patricia; Ciais, Philippe; Clark, Douglas B.; Dankers, Rutger; Falloon, Pete D.; Ito, Akihiko; Kahana, Ron; Kleidon, Axel; Lomas, Mark R.; Nishina, Kazuya; Ostberg, Sebastian; Pavlick, Ryan; Peylin, Philippe; Schaphoff, Sibyll; Vuichard, Nicolas; Warszawski, Lila; Wiltshire, Andy; Woodward, F. Ian

2014-01-01

Future climate change and increasing atmospheric CO2 are expected to cause major changes in vegetation structure and function over large fractions of the global land surface. Seven global vegetation models are used to analyze possible responses to future climate simulated by a range of general circulation models run under all four representative concentration pathway scenarios of changing concentrations of greenhouse gases. All 110 simulations predict an increase in global vegetation carbon to 2100, but with substantial variation between vegetation models. For example, at 4 °C of global land surface warming (510–758 ppm of CO2), vegetation carbon increases by 52–477 Pg C (224 Pg C mean), mainly due to CO2 fertilization of photosynthesis. Simulations agree on large regional increases across much of the boreal forest, western Amazonia, central Africa, western China, and southeast Asia, with reductions across southwestern North America, central South America, southern Mediterranean areas, southwestern Africa, and southwestern Australia. Four vegetation models display discontinuities across 4 °C of warming, indicating global thresholds in the balance of positive and negative influences on productivity and biomass. In contrast to previous global vegetation model studies, we emphasize the importance of uncertainties in projected changes in carbon residence times. We find, when all seven models are considered for one representative concentration pathway × general circulation model combination, such uncertainties explain 30% more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151% for non-HYBRID4 models. A change in research priorities away from production and toward structural dynamics and demographic processes is recommended. PMID:24344265

Optimization of pH, temperature and CaCl2 concentrations for Ricotta cheese production from Buffalo cheese whey using Response Surface Methodology.

PubMed

Rashid, Abdul Ahid; Huma, Nuzhat; Zahoor, Tahir; Asgher, Muhammad

2017-02-01

The recovery of milk constituents from cheese whey is affected by various processing conditions followed during production of Ricotta cheese. The objective of the present investigation was to optimize the temperature (60-90 °C), pH (3-7) and CaCl2 concentration (2·0-6·0 mm) for maximum yield/recovery of milk constituents. The research work was carried out in two phases. In 1st phase, the influence of these processing conditions was evaluated through 20 experiments formulated by central composite design (CCD) keeping the yield as response factor. The results obtained from these experiments were used to optimize processing conditions for maximum yield using response surface methodology (RSM). The three best combinations of processing conditions (90 °C, pH 7, CaCl2 6 mm), (100 °C, pH 5, CaCl2 4 mm) and (75 °C, pH 8·4, CaCl2 4 mm) were exploited in the next phase for Ricotta cheese production from a mixture of Buffalo cheese whey and skim milk (9 : 1) to determine the influence of optimized conditions on the cheese composition. Ricotta cheeses were analyzed for various physicochemical (moisture, fat, protein, lactose, total solids, pH and acidity indicated) parameters during storage of 60 d at 4 ± 2 °C after every 15 d interval. Ricotta cheese prepared at 90 °C, pH 7 and CaCl2 6 mm exhibited the highest cheese yield, proteins and total solids, while high fat content was recorded for cheese processed at 100 °C, pH 5 and 4 mm CaCl2 concentration. A significant storage-related increase in acidity and NPN was recorded for all cheese samples.

Quantitative estimation of surface ocean productivity and bottom water oxygen concentration using benthic foraminifera

NASA Astrophysics Data System (ADS)

Loubere, Paul

1994-10-01

An electronic supplement of this material may be obtained on adiskette or Anonymous FTP from KOSMOS.AGU.ORG. (LOGIN toAGU's FTP account using ANONYMOUS as the usemame andGUEST as the password. Go to the right directory by typing CDAPEND. Type LS to see what files are available. Type GET and thename of the file to get it. Finally, type EXIT to leave the system.)(Paper 94PA01624, Quantitative estimation of surface oceanproductivity and bottom water concentration using benthicforaminifera, by P. Loubere). Diskette may be ordered from AmericanGeophysical Union, 2000 Florida Avenue, N.W., Washington, DC20009; $15.00. Payment must accompany order.Quantitative estimation of surface ocean productivity and bottom water oxygen concentration with benthic foraminifera was attempted using 70 samples from equatorial and North Pacific surface sediments. These samples come from a well defined depth range in the ocean, between 2200 and 3200 m, so that depth related factors do not interfere with the estimation. Samples were selected so that foraminifera were well preserved in the sediments and temperature and salinity were nearly uniform (T = 1.5° C; S = 34.6‰). The sample set was also assembled so as to minimize the correlation often seen between surface ocean productivity and bottom water oxygen values (r² = 0.23 for prediction purposes in this case). This procedure reduced the chances of spurious results due to correlations between the environmental variables. The samples encompass a range of productivities from about 25 to >300 gC m-2 yr-1, and a bottom water oxygen range from 1.8 to 3.5 ml/L. Benthic foraminiferal assemblages were quantified using the >62 µm fraction of the sediments and 46 taxon categories. MANOVA multivariate regression was used to project the faunal matrix onto the two environmental dimensions using published values for productivity and bottom water oxygen to calibrate this operation. The success of this regression was measured with the multivariate r² which was 0.98 for the productivity dimension and 0.96 for the oxygen dimension. These high coefficients indicate that both environmental variables are strongly imbedded in the faunal data matrix. Analysis of the beta regression coefficients shows that the environmental signals are carried by groups of taxa which are consistent with previous work characterizing benthic foraminiferal responses to productivity and bottom water oxygen. The results of this study suggest that benthic foraminiferal assemblages can be used for quantitative reconstruction of surface ocean productivity and bottom water oxygen concentrations if suitable surface sediment calibration data sets are developed and appropriate means for detecting no-analog samples are found.

Scavenger receptor WC1 contributes to the γδ T cell response to Leptospira.

PubMed

Wang, Fei; Herzig, Carolyn T A; Chen, Chuang; Hsu, Haoting; Baldwin, Cynthia L; Telfer, Janice C

2011-03-01

WC1 molecules are exclusively expressed on the surface of γδ T cells. They belong to the scavenger receptor cysteine-rich (SRCR) superfamily and are encoded by a multi-gene family. WC1 molecules have been grouped on the basis of antibody reactivity. The expression of WC1 molecules from these serologically defined groups is correlated with differences in γδ T cell responses. The expression of receptors within the WC1.1 group correlates with the capacity of γδ T cells to respond to Leptospira antigen. In this study, we used RNA interference to directly investigate the role of WC1 expression in the response to Leptospira borgpetersenii. We found that when three out of thirteen WC1 gene products were downregulated by RNA interference, γδ T cell proliferation and IFN-γ production in response to Leptospira antigen was significantly reduced. Our data demonstrate that specific receptors in the WC1 family directly participate in Leptospira recognition and/or activation of γδ T cells. Copyright © 2010 Elsevier Ltd. All rights reserved.

Redox-mediated quorum sensing in plants.

PubMed

Fuller, Alexandra W; Young, Phoebe; Pierce, B Daniel; Kitson-Finuff, Jamie; Jain, Purvi; Schneider, Karl; Lazar, Stephen; Taran, Olga; Palmer, Andrew G; Lynn, David G

2017-01-01

The rhizosphere, the narrow zone of soil around plant roots, is a complex network of interactions between plants, bacteria, and a variety of other organisms. The absolute dependence on host-derived signals, or xenognosins, to regulate critical developmental checkpoints for host commitment in the obligate parasitic plants provides a window into the rhizosphere's chemical dynamics. These sessile intruders use H2O2 in a process known as semagenesis to chemically modify the mature root surfaces of proximal host plants and generate p-benzoquinones (BQs). The resulting redox-active signaling network regulates the spatial and temporal commitments necessary for host attachment. Recent evidence from non-parasites, including Arabidopsis thaliana, establishes that reactive oxygen species (ROS) production regulates similar redox circuits related to root recognition, broadening xenognosins' role beyond the parasites. Here we compare responses to the xenognosin dimethoxybenzoquinone (DMBQ) between the parasitic plant Striga asiatica and the non-parasitic A. thaliana. Exposure to DMBQ simulates the proximity of a mature root surface, stimulating an increase in cytoplasmic Ca2+ concentration in both plants, but leads to remarkably different phenotypic responses in the parasite and non-parasite. In S. asiatica, DMBQ induces development of the host attachment organ, the haustorium, and decreases ROS production at the root tip, while in A. thaliana, ROS production increases and further growth of the root tip is arrested. Obstruction of Ca2+ channels and the addition of antioxidants both lead to a decrease in the DMBQ response in both parasitic and non-parasitic plants. These results are consistent with Ca2+ regulating the activity of NADPH oxidases, which in turn sustain the autocatalytic production of ROS via an external quinone/hydroquinone redox cycle. Mechanistically, this chemistry is similar to black and white photography with the emerging dynamic reaction-diffusion network laying the foundation for the precise temporal and spatial control underlying rhizosphere architecture.

Applying Terrain and Hydrological Editing to Tandem-X Data to Create a Consumer-Ready Worlddem Product

NASA Astrophysics Data System (ADS)

Collins, J.; Riegler, G.; Schrader, H.; Tinz, M.

2015-04-01

The Geo-intelligence division of Airbus Defence and Space and the German Aerospace Center (DLR) have partnered to produce the first fully global, high-accuracy Digital Surface Model (DSM) using SAR data from the twin satellite constellation: TerraSAR-X and TanDEM-X. The DLR is responsible for the processing and distribution of the TanDEM-X elevation model for the world's scientific community, while Airbus DS is responsible for the commercial production and distribution of the data, under the brand name WorldDEM. For the provision of a consumer-ready product, Airbus DS undertakes several steps to reduce the effect of radar-specific artifacts in the WorldDEM data. These artifacts can be divided into two categories: terrain and hydrological. Airbus DS has developed proprietary software and processes to detect and correct these artifacts in the most efficient manner. Some processes are fullyautomatic, while others require manual or semi-automatic control by operators.

Forest productivity in southwestern Europe is controlled by coupled North Atlantic and Atlantic Multidecadal Oscillations.

PubMed

Madrigal-González, Jaime; Ballesteros-Cánovas, Juan A; Herrero, Asier; Ruiz-Benito, Paloma; Stoffel, Markus; Lucas-Borja, Manuel E; Andivia, Enrique; Sancho-García, Cesar; Zavala, Miguel A

2017-12-20

The North Atlantic Oscillation (NAO) depicts annual and decadal oscillatory modes of variability responsible for dry spells over the European continent. The NAO therefore holds a great potential to evaluate the role, as carbon sinks, of water-limited forests under climate change. However, uncertainties related to inconsistent responses of long-term forest productivity to NAO have so far hampered firm conclusions on its impacts. We hypothesize that, in part, such inconsistencies might have their origin in periodical sea surface temperature anomalies in the Atlantic Ocean (i.e., Atlantic Multidecadal Oscillation, AMO). Here we show strong empirical evidence in support of this hypothesis using 120 years of periodical inventory data from Iberian pine forests. Our results point to AMO + NAO + and AMO - NAO - phases as being critical for forest productivity, likely due to decreased winter water balance and abnormally low winter temperatures, respectively. Our findings could be essential for the evaluation of ecosystem functioning vulnerabilities associated with increased climatic anomalies under unprecedented warming conditions in the Mediterranean.

L-band Microwave Remote Sensing and Land Data Assimilation Improve the Representation of Prestorm Soil Moisture Conditions for Hydrologic Forecasting

NASA Technical Reports Server (NTRS)

Crow, W. T.; Chen, F.; Reichle, R. H.; Liu, Q.

2017-01-01

Recent advances in remote sensing and land data assimilation purport to improve the quality of antecedent soil moisture information available for operational hydrologic forecasting. We objectively validate this claim by calculating the strength of the relationship between storm-scale runoff ratio (i.e., total stream flow divided by total rainfall accumulation in depth units) and pre-storm surface soil moisture estimates from a range of surface soil moisture data products. Results demonstrate that both satellite-based, L-band microwave radiometry and the application of land data assimilation techniques have significantly improved the utility of surface soil moisture data sets for forecasting stream flow response to future rainfall events.

L-band microwave remote sensing and land data assimilation improve the representation of pre-storm soil moisture conditions for hydrologic forecasting.

PubMed

Crow, W T; Chen, F; Reichle, R H; Liu, Q

2017-06-16

Recent advances in remote sensing and land data assimilation purport to improve the quality of antecedent soil moisture information available for operational hydrologic forecasting. We objectively validate this claim by calculating the strength of the relationship between storm-scale runoff ratio (i.e., total stream flow divided by total rainfall accumulation in depth units) and pre-storm surface soil moisture estimates from a range of surface soil moisture data products. Results demonstrate that both satellite-based, L-band microwave radiometry and the application of land data assimilation techniques have significantly improved the utility of surface soil moisture data sets for forecasting stream flow response to future rainfall events.

L-band microwave remote sensing and land data assimilation improve the representation of pre-storm soil moisture conditions for hydrologic forecasting

PubMed Central

Crow, W.T.; Chen, F.; Reichle, R.H.; Liu, Q.

2018-01-01

Recent advances in remote sensing and land data assimilation purport to improve the quality of antecedent soil moisture information available for operational hydrologic forecasting. We objectively validate this claim by calculating the strength of the relationship between storm-scale runoff ratio (i.e., total stream flow divided by total rainfall accumulation in depth units) and pre-storm surface soil moisture estimates from a range of surface soil moisture data products. Results demonstrate that both satellite-based, L-band microwave radiometry and the application of land data assimilation techniques have significantly improved the utility of surface soil moisture data sets for forecasting stream flow response to future rainfall events. PMID:29657342

Inhibition by ultraviolet and photosynthetically available radiation lowers model estimates of depth-integrated picophytoplankton photosynthesis: global predictions for Prochlorococcus and Synechococcus.

PubMed

Neale, Patrick J; Thomas, Brian C

2017-01-01

Phytoplankton photosynthesis is often inhibited by ultraviolet (UV) and intense photosynthetically available radiation (PAR), but the effects on ocean productivity have received little consideration aside from polar areas subject to periodic enhanced UV-B due to depletion of stratospheric ozone. A more comprehensive assessment is important for understanding the contribution of phytoplankton production to the global carbon budget, present and future. Here, we consider responses in the temperate and tropical mid-ocean regions typically dominated by picophytoplankton including the prokaryotic lineages, Prochlorococcus and Synechococcus. Spectral models of photosynthetic response for each lineage were constructed using model strains cultured at different growth irradiances and temperatures. In the model, inhibition becomes more severe once exposure exceeds a threshold (E max ) related to repair capacity. Model parameters are presented for Prochlorococcus adding to those previously presented for Synechococcus. The models were applied to estimate midday, water column photosynthesis based on an atmospheric model of spectral radiation, satellite-derived spectral water transparency and temperature. Based on a global survey of inhibitory exposure severity, a full-latitude section of the mid-Pacific and near-equatorial region of the east Pacific were identified as representative regions for prediction of responses over the entire water column. Comparing predictions integrated over the water column including versus excluding inhibition, production was 7-28% lower due to inhibition depending on strain and site conditions. Inhibition was consistently greater for Prochlorococcus compared to two strains of Synechococcus. Considering only the surface mixed layer, production was inhibited 7-73%. On average, including inhibition lowered estimates of midday productivity around 20% for the modeled region of the Pacific with UV accounting for two-thirds of the reduction. In contrast, most other productivity models either ignore inhibition or only include PAR inhibition. Incorporation of E max model responses into an existing spectral model of depth-integrated, daily production will enable efficient global predictions of picophytoplankton productivity including inhibition. © 2016 John Wiley & Sons Ltd.

Anthropogenic climate change has altered primary productivity in Lake Superior

PubMed Central

O'Beirne, M. D.; Werne, J. P.; Hecky, R. E.; Johnson, T. C.; Katsev, S.; Reavie, E. D.

2017-01-01

Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems. PMID:28598413

Anthropogenic climate change has altered primary productivity in Lake Superior.

PubMed

O'Beirne, M D; Werne, J P; Hecky, R E; Johnson, T C; Katsev, S; Reavie, E D

2017-06-09

Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems.