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Sample records for dunaliella salina strains

  1. Phenotypic and genetic characterization of Dunaliella (Chlorophyta) from Indian salinas and their diversity

    Science.gov (United States)

    2012-01-01

    Background The genus Dunaliella (Class – Chlorophyceae) is widely studied for its tolerance to extreme habitat conditions, physiological aspects and many biotechnological applications, such as a source of carotenoids and many other bioactive compounds. Biochemical and molecular characterization is very much essential to fully explore the properties and possibilities of the new isolates of Dunaliella. In India, hyper saline lakes and salt pans were reported to bloom with Dunaliella spp. However, except for the economically important D. salina, other species are rarely characterized taxonomically from India. Present study was conducted to describe Dunaliella strains from Indian salinas using a combined morphological, physiological and molecular approach with an aim to have a better understanding on the taxonomy and diversity of this genus from India. Results Comparative phenotypic and genetic studies revealed high level of diversity within the Indian Dunaliella isolates. Species level identification using morphological characteristics clearly delineated two strains of D. salina with considerable β-carotene content (>20 pg/cell). The variation in 18S rRNA gene size, amplified with MA1-MA2 primers, ranged between ~1800 and ~2650 base pairs, and together with the phylogeny based on ITS gene sequence provided a pattern, forming five different groups within Indian Dunaliella isolates. Superficial congruency was observed between ITS and rbcL gene phylogenetic trees with consistent formation of major clades separating Indian isolates into two distinct clusters, one with D. salina and allied strains, and another one with D. viridis and allied strains. Further in both the trees, few isolates showed high level of genetic divergence than reported previously for Dunaliella spp. This indicates the scope of more numbers of clearly defined/unidentified species/sub-species within Indian Dunaliella isolates. Conclusion Present work illustrates Indian Dunaliella strains

  2. Potential of New Isolates of Dunaliella Salina for Natural β-Carotene Production

    Directory of Open Access Journals (Sweden)

    Yanan Xu

    2018-02-01

    Full Text Available The halotolerant microalga Dunaliella salina has been widely studied for natural β-carotene production. This work shows biochemical characterization of three newly isolated Dunaliella salina strains, DF15, DF17, and DF40, compared with D. salina CCAP 19/30 and D. salina UTEX 2538 (also known as D. bardawil. Although all three new strains have been genetically characterized as Dunaliella salina strains, their ability to accumulate carotenoids and their capacity for photoprotection against high light stress are different. DF15 and UTEX 2538 reveal great potential for producing a large amount of β-carotene and maintained a high rate of photosynthesis under light of high intensity; however, DF17, DF40, and CCAP 19/30 showed increasing photoinhibition with increasing light intensity, and reduced contents of carotenoids, in particular β-carotene, suggesting that the capacity of photoprotection is dependent on the cellular content of carotenoids, in particular β-carotene. Strong positive correlations were found between the cellular content of all-trans β-carotene, 9-cis β-carotene, all-trans α-carotene and zeaxanthin but not lutein in the D. salina strains. Lutein was strongly correlated with respiration in photosynthetic cells and strongly related to photosynthesis, chlorophyll and respiration, suggesting an important and not hitherto identified role for lutein in coordinated control of the cellular functions of photosynthesis and respiration in response to changes in light conditions, which is broadly conserved in Dunaliella strains. Statistical analysis based on biochemical data revealed a different grouping strategy from the genetic classification of the strains. The significance of these data for strain selection for commercial carotenoid production is discussed.

  3. Carotenoid fluorescence in Dunaliella salina

    NARCIS (Netherlands)

    Kleinegris, D.M.M.; Es, van M.A.; Janssen, M.G.J.; Brandenburg, W.A.; Wijffels, R.H.

    2010-01-01

    Dunaliella salina is a halotolerant green alga that is well known for its carotenoid producing capacity. The produced carotenoids are mainly stored in lipid globules. For various research purposes, such as production and extraction kinetics, we would like to determine and/or localise the carotenoid

  4. Effect of salinity on the quantity and quality of carotenoids accumulated by Dunaliella salina (strain CONC-007 and Dunaliella bardawil (strain ATCC 30861 Chlorophyta

    Directory of Open Access Journals (Sweden)

    PATRICIA I GÓMEZ

    2003-01-01

    Full Text Available Dunaliella salina and D. bardawil are well-known microalgae accumulating high levels of b-carotene under growth-limiting conditions. In both taxa, this pigment is primarily composed of the isomers 9-cis and all-trans. The 9-cis b-carotene occurs only in natural sources and is the most attractive from a commercial point of view. The conditions that enhance the preferred accumulation of 9-cis b-carotene in D. salina are controversial and they have not been well established yet. This study examined the effect of salinity on the quantity and quality of total carotenoids and b-carotene isomers accumulated by D. salina (strain CONC-007 and D. bardawil (strain ATCC 30861 grown in two media with different nutritional compositions (PES and ART and at salt concentrations of 1M, 2M and 3M NaCl. Total carotenoids were determined by spectrophotometry and b-carotene isomers, by HPLC. The highest carotenoid contents per cell were obtained at 2M NaCl in both taxa. In both media, an increase of the 9-cis/all-trans b-carotene ratio was observed in D. bardawil when the salt concentration increased, with a maximum value of 2.6 (in ART medium at 3M NaCl. In D. salina this ratio did not exhibit the same pattern, and the salt concentrations for maximal ratios were different in both media. The highest ratio obtained for this strain was 4.3 (in ART medium at 2M NaCl.

  5. Cadmium induced oxidative stress in Dunaliella salina | Moradshahi ...

    African Journals Online (AJOL)

    The unicellular green algae Dunaliella salina contains various antioxidants which protect the cell from oxidative damage due to environmental stresses such as heavy metal stress. In the present study, the response of D. salina at the stationary growth phase to oxidative stress generated by cadmium chloride was ...

  6. Metabolic engineering of Dunaliella salina for production of ketocarotenoids.

    Science.gov (United States)

    Anila, N; Simon, Daris P; Chandrashekar, Arun; Ravishankar, G A; Sarada, R

    2016-03-01

    Dunaliella is a commercially important marine alga producing high amount of β-carotene. The use of Dunaliella as a potential transgenic system for the production of recombinant proteins has been recently recognized. The present study reports for the first time the metabolic engineering of carotenoid biosynthesis in Dunaliella salina for ketocarotenoid production. The pathway modification included the introduction of a bkt gene from H. pluvialis encoding β-carotene ketolase (4,4'β-oxygenase) along with chloroplast targeting for the production of ketocarotenoids. The bkt under the control of Dunaliella Rubisco smaller subunit promoter along with its transit peptide sequence was introduced into the alga through standardized Agrobacterium-mediated transformation procedure. The selected transformants were confirmed using GFP and GUS expression, PCR and southern blot analysis. A notable upregulation of the endogenous hydroxylase level of transformants was observed where the BKT expression was higher in nutrient-limiting conditions. Carotenoid analysis of the transformants through HPLC and MS analysis showed the presence of astaxanthin and canthaxanthin with maximum content of 3.5 and 1.9 µg/g DW, respectively. The present study reports the feasibility of using D. salina for the production of ketocarotenoids including astaxanthin.

  7. The Selectivity of Milking of Dunaliella salina

    NARCIS (Netherlands)

    Kleinegris, D.M.M.; Janssen, M.G.J.; Brandenburg, W.A.; Wijffels, R.H.

    2010-01-01

    The process of the simultaneous production and extraction of carotenoids, milking, of Dunaliella salina was studied. We would like to know the selectivity of this process. Could all the carotenoids produced be extracted? And would it be possible to vary the profile of the produced carotenoids and,

  8. INFLUENCIA DE LA SALINIDAD Y LA IRRADIANCIA SOBRE EL CRECIMIENTO Y COMPOSICIÓN BIOQUÍMICA DE UNA NUEVA CEPA DE Dunaliella salina, PROVENIENTE DE LAS SALINAS DE ARAYA, VENEZUELA | INFLUENCE OF SALINITY AND IRRADIANCE ON GROWTH AND BIOCHEMICAL COMPOSITION OF A NEW STRAIN of Dunaliella salina FROM THE ARAYA

    Directory of Open Access Journals (Sweden)

    Miguel Guevara

    2016-08-01

    Full Text Available Dunaliella salina is a microalga used for the production of metabolites of high industrial and pharmaceutical value. The combined effect of irradiance and salinity on growth, pigment production and biochemical composition of this strain were evaluated in order to contribute to the knowledge of the physiological responses of this new isolate of D. salina from Araya saltworks, to changes in the conditions of its environment. It was aslo intendend to increase the variety of native microalgae species which can serve as sources of bioproduction for bioactive compounds, biomass and metabolites of application in pharmaceuticals and biomedical industries. Batch cultures of the strain of D. salina were conducted for 22 d at f/2 medium Guillard (0.88 mmol.L-1 of nitrogen at 27 ± 2°C, pH 7.8; photoperiod 12 h light: 12 h darkness, continuous aeration (150 mL.L-1 in two salinities (40 and 250 UPS and irradiances (195 and 295 µmolphotons.m-2.s-1. Population growth was evaluated daily and at the end of the trial the contents of biomass, pigments, proteins, lipids, carbohydrates and cell size were determined. The growth rate of the new strain of D. salina decreased with increasing salinity and irradiance. However, cell size, biomass, content of proteins, lipids, carbohydrates, total carotenoids and β-carotene increased with increasing irradiance and salinity. In addition, the potential of this strain for the production of β-carotene was shown.

  9. Growth effects on mixed culture of Dunaliella salina and ...

    African Journals Online (AJOL)

    Dunaliella salina and Phaeodactylum tricornutum are two important marine microalgae rich in bioactive substances and other high-value constituents. In this study, growth effects on mixed culture of these two microalgae were studied under different inoculation proportions (10:0, 7:3, 5:5, 3:7, 0:10) and low, medium and high ...

  10. Harvesting of Dunaliella salina by membrane filtration at pilot scale

    KAUST Repository

    Monte, Joana

    2017-09-02

    The microalgae Dunaliella salina is industrially produced due to its high content in carotenoids induced by low nitrogen and high salinity conditions. D. salina with low carotenoids content also produces other added value compounds, however its recovery have hardly been studied. This work aims to examine the potential of pre-concentrating D. salina by membrane processing prior to a final harvesting step by low-shear centrifugation. The aim is to minimize the overall energy expenditure and reduce capital costs, while assuring a minimal loss of cell integrity. This task is challenging, considering the sensitivity of D. salina to shear. Harvesting of D. salina by ultrafiltration allowed reaching a final concentration factor of 5.9, with an average permeate flux of 31 L/(m2 h). The Total Cost of Ownership and energy consumption for harvesting are respectively 52% and 45% lower when applying a two-step approach with pre-concentration (ultrafiltration) compared to only harvesting by centrifugation.

  11. Harvesting of Dunaliella salina by membrane filtration at pilot scale

    KAUST Repository

    Monte, Joana; Sá , Marta; Galinha, Clá udia F.; Costa, Luí s; Hoekstra, Herre; Brazinha, Carla; Crespo, Joã o G.

    2017-01-01

    The microalgae Dunaliella salina is industrially produced due to its high content in carotenoids induced by low nitrogen and high salinity conditions. D. salina with low carotenoids content also produces other added value compounds, however its recovery have hardly been studied. This work aims to examine the potential of pre-concentrating D. salina by membrane processing prior to a final harvesting step by low-shear centrifugation. The aim is to minimize the overall energy expenditure and reduce capital costs, while assuring a minimal loss of cell integrity. This task is challenging, considering the sensitivity of D. salina to shear. Harvesting of D. salina by ultrafiltration allowed reaching a final concentration factor of 5.9, with an average permeate flux of 31 L/(m2 h). The Total Cost of Ownership and energy consumption for harvesting are respectively 52% and 45% lower when applying a two-step approach with pre-concentration (ultrafiltration) compared to only harvesting by centrifugation.

  12. Increasing β-carotene content of phytoplankton Dunaliella salina using different salinity media

    Science.gov (United States)

    Hermawan, J.; Masithah, E. D.; Tjahjaningsih, W.; Abdillah, A. A.

    2018-04-01

    Dunaliella salina have got great attention in the nutritional, pharmaceutical and cosmetic companies because contain β-carotene. β-carotene functions as antioxidants and precursors of vitamin A and can treat tumors and cancer in humans. The content of β-carotene in D. salina can be increased by increasing salinity levels in the culture medium. The aim of this study was to determine whether increasing salinity may increas β-carotene content of phytoplankton D. salina. The research use data collection method with direct observation and then analyzed the result with descriptive method. The results showed that different salinity of media can influenced β-carotene content of D. salina. The highest β-carotene content of D. salina was at treatment B (30 ppt) which equal to 2.312 mg/L on 10th day. The production of β-carotene in D. salina can be increased was other environmental stress treatments in the form of stress-temperature, light and nutrients using.

  13. Neutral lipid production in Dunaliella salina during osmotic stress and adaptation

    DEFF Research Database (Denmark)

    Yao, Shuo; Lu, Jingquan; Sárossy, Zsuzsa

    2016-01-01

    The salt-tolerant green microalga Dunaliella salina can survive both hyper- and hypo-osmotic shock. Upon osmotic shock, the cells transiently and rapidly decreased or increased in size within minutes and slowly over hours acquired their original cell size and volume. Cell size distribution differs...... significantly in the cultures grown in the salinity range from 1.5 to 15 % NaCl. By using Nile Red fluorescence to detect neutral lipids, it became clear that only hyper-osmotic shock on cells induced transient neutral lipid appearance in D. salina, while those transferred from 9 to 15 % NaCl stimulated...

  14. Antifouling potential of the marine microalga Dunaliella salina.

    Science.gov (United States)

    Gao, Min; Li, Fengchao; Su, Rongguo; Wang, Ke; Li, Xuzhao; Lu, Wei

    2014-11-01

    Marine organisms have usually been viewed as sources of environmentally friendly compounds with antifouling activity. We performed a series of operations to investigate the antifouling potential of the marine microalga Dunaliella salina. For the ethyl acetate crude extract, the antialgal activity was significant, and the EC50 value against Skeletonema costatum was 58.9 μg ml(-1). The isolated purified extract was tested for antifouling activity, the EC 50 value against S. costatum was 21.2 μg ml(-1), and the LC50 against Balanus amphitrite larvae was 18.8 μg ml(-1). Subsequently, both UHR-TOF-MS and GC-MS were used for the structural elucidation of the compounds, and a series of unsaturated and saturated 16- and 18-carbon fatty acids were detected. The data suggested that the fatty acid extracts from D. salina possess high antifouling activity, and could be used as substitutes for potent, toxic antifouling compounds.

  15. Energy-producing electro-flocculation for harvest of Dunaliella salina.

    Science.gov (United States)

    Liu, Qing; Zhang, Meng; Lv, Tao; Chen, Hongjun; Chika, Anthony Okonkwo; Xiang, Changli; Guo, Minxue; Wu, Minghui; Li, Jianjun; Jia, Lishan

    2017-10-01

    In this study, an efficient electro-flocculation process for Dunaliella salina with energy production by aluminum-air battery has been successfully applied. The formed aluminum hydroxide hydrates during discharging of battery were positively charged, which have a great potential for microalgae flocculation. The precipitation of aluminum hydroxide hydrates by algae also could improve the performance of aluminum-air battery. The harvesting efficiency could reach 97% in 20mins with energy production of 0.11kWh/kg. This discharging electro-flocculation (DEF) technology provides a new energy producing process to effectively harvest microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Effect of mixing rate on Beta-carotene production and extraction by dunaliella salina in two-phase bioreactors

    NARCIS (Netherlands)

    Hejazi, M.; Andrysiewicz, E.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    beta-Carotene has many applications in the food, cosmetic, and pharmaceutical industries; Dunaliella salina is currently the main source for natural beta-carotene. We have investigated the effect of mixing rate and whether it leads to the facilitated release of beta-carotene from the cells of

  17. Heterologous gene expression driven by carbonic anhydrase gene promoter in Dunaliella salina

    Science.gov (United States)

    Yurong, Chai; Yumin, Lu; Tianyun, Wang; Weihong, Hou; Lexun, Xue

    2006-12-01

    Dunaliella salina, a halotolerant unicellular green alga without a rigid cell wall, can live in salinities ranging from 0.05 to 5 mol/L NaCl. These features of D. salina make it an ideal host for the production of antibodies, oral vaccine, and commercially valuable polypeptides. To produce high level of heterologous proteins from D. salina, highly efficient promoters are required to drive expression of target genes under controlled condition. In the present study, we cloned a 5' franking region of 1.4 kb from the carbonic anhydrase ( CAH) gene of D. salina by genomic walking and PCR. The fragment was ligated to the pMD18-T vector and characterized. Sequence analysis indicated that this region contained conserved motifs, including a TATA- like box and CAAT-box. Tandem (GT)n repeats that had a potential role of transcriptional control, were also found in this region. The transcription start site (TSS) of the CAH gene was determined by 5' RACE and nested PCR method. Transformation assays showed that the 1.4 kb fragment was able to drive expression of the selectable bar (bialaphos resistance) gene when the fusion was transformed into D. salina by biolistics. Northern blotting hybridizations showed that the bar transcript was most abundant in cells grown in 2 mol/L NaCl, and less abundant in 0.5 mol/L NaCl, indicating that expression of the bar gene was induced at high salinity. These results suggest the potential use of the CAH gene promoter to induce the expression of heterologous genes in D. salina under varied salt condition.

  18. Interspecific competition and allelopathic interaction between Karenia mikimotoi and Dunaliella salina in laboratory culture

    Science.gov (United States)

    He, Dong; Liu, Jiao; Hao, Qiang; Ran, Lihua; Zhou, Bin; Tang, Xuexi

    2016-03-01

    Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature ( P =0.013) and irradiance ( P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.

  19. The Dunaliella salina organelle genomes: large sequences, inflated with intronic and intergenic DNA

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David R.; Lee, Robert W.; Cushman, John C.; Magnuson, Jon K.; Tran, Duc; Polle, Juergen E.

    2010-05-07

    Abstract Background: Dunaliella salina Teodoresco, a unicellular, halophilic green alga belonging to the Chlorophyceae, is among the most industrially important microalgae. This is because D. salina can produce massive amounts of β-carotene, which can be collected for commercial purposes, and because of its potential as a feedstock for biofuels production. Although the biochemistry and physiology of D. salina have been studied in great detail, virtually nothing is known about the genomes it carries, especially those within its mitochondrion and plastid. This study presents the complete mitochondrial and plastid genome sequences of D. salina and compares them with those of the model green algae Chlamydomonas reinhardtii and Volvox carteri. Results: The D. salina organelle genomes are large, circular-mapping molecules with ~60% noncoding DNA, placing them among the most inflated organelle DNAs sampled from the Chlorophyta. In fact, the D. salina plastid genome, at 269 kb, is the largest complete plastid DNA (ptDNA) sequence currently deposited in GenBank, and both the mitochondrial and plastid genomes have unprecedentedly high intron densities for organelle DNA: ~1.5 and ~0.4 introns per gene, respectively. Moreover, what appear to be the relics of genes, introns, and intronic open reading frames are found scattered throughout the intergenic ptDNA regions -- a trait without parallel in other characterized organelle genomes and one that gives insight into the mechanisms and modes of expansion of the D. salina ptDNA. Conclusions: These findings confirm the notion that chlamydomonadalean algae have some of the most extreme organelle genomes of all eukaryotes. They also suggest that the events giving rise to the expanded ptDNA architecture of D. salina and other Chlamydomonadales may have occurred early in the evolution of this lineage. Although interesting from a genome evolution standpoint, the D. salina organelle DNA sequences will aid in the development of a viable

  20. The Dunaliella salina organelle genomes: large sequences, inflated with intronic and intergenic DNA

    Directory of Open Access Journals (Sweden)

    Tran Duc

    2010-05-01

    Full Text Available Abstract Background Dunaliella salina Teodoresco, a unicellular, halophilic green alga belonging to the Chlorophyceae, is among the most industrially important microalgae. This is because D. salina can produce massive amounts of β-carotene, which can be collected for commercial purposes, and because of its potential as a feedstock for biofuels production. Although the biochemistry and physiology of D. salina have been studied in great detail, virtually nothing is known about the genomes it carries, especially those within its mitochondrion and plastid. This study presents the complete mitochondrial and plastid genome sequences of D. salina and compares them with those of the model green algae Chlamydomonas reinhardtii and Volvox carteri. Results The D. salina organelle genomes are large, circular-mapping molecules with ~60% noncoding DNA, placing them among the most inflated organelle DNAs sampled from the Chlorophyta. In fact, the D. salina plastid genome, at 269 kb, is the largest complete plastid DNA (ptDNA sequence currently deposited in GenBank, and both the mitochondrial and plastid genomes have unprecedentedly high intron densities for organelle DNA: ~1.5 and ~0.4 introns per gene, respectively. Moreover, what appear to be the relics of genes, introns, and intronic open reading frames are found scattered throughout the intergenic ptDNA regions -- a trait without parallel in other characterized organelle genomes and one that gives insight into the mechanisms and modes of expansion of the D. salina ptDNA. Conclusions These findings confirm the notion that chlamydomonadalean algae have some of the most extreme organelle genomes of all eukaryotes. They also suggest that the events giving rise to the expanded ptDNA architecture of D. salina and other Chlamydomonadales may have occurred early in the evolution of this lineage. Although interesting from a genome evolution standpoint, the D. salina organelle DNA sequences will aid in the

  1. Dunaliella salina as marine microalga highly tolerant to but a poor remover of cadmium

    International Nuclear Information System (INIS)

    Folgar, S.; Torres, E.; Perez-Rama, M.; Cid, A.; Herrero, C.; Abalde, J.

    2009-01-01

    Cadmium tolerance and removal in the marine microalga Dunaliella salina were studied in cultures exposed to different metal concentrations (5-120 mg Cd l -1 ) for 96 h. This microalga can be included in the group of microalgal species most tolerant to cadmium due to the high value of EC50 that it possesses (48.9 mg Cd l -1 at 96 h of culture). The greater percentage of cadmium removed was obtained in cultures exposed to 5 mg Cd l -1 at 96 h, but removing only 11.3% of the added cadmium. In all cultures, the quantity of cadmium removed intracellularly was much lower than the bioadsorbed quantity and it was proportional to the sulfhydryl group levels. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of cadmium by living cells of D. salina.

  2. Antioxidant activity of three microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana clone Tahiti

    Science.gov (United States)

    Widowati, Ita; Zainuri, Muhammad; Pancasakti Kusumaningrum, Hermien; Susilowati, Ragil; Hardivillier, Yann; Leignel, Vincent; Bourgougnon, Nathalie; Mouget, Jean-Luc

    2017-02-01

    Natural alternatives antioxidant source has become a trending topic in the past decades to replace synthetic antioxidant. Microalgae have been mentioned to show interesting bioactive properties and one of them is its antioxidant activity. This study aims to evaluate the potential of three microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbanaas new source of natural antioxidant. Proximate analysis and total phenolic content of D. salina, T. chuii and I. galbanas were determined. Antioxidant activity of methanolic extracts of these three species prepared in different concentration (50, 100, 250, 500, and 1000 ppm) was performed through DPPH assay. I. galbana clone Tahiti demonstrated a highest antioxidant potential with 61.64 of inhibition at 50 ppm followed by D. salina with 58.45 % of inhibition and T. chuii with 52.58 % of inhibition. I. galbana clone Tahiti was the best antioxidant with total phenol content of 17.798 mg GAE g-1 extract at 50 ppm; followed by T. chuii 16.868 mg GAE g-1 extract and the lowest was D. salina with 4.672 mg GAE g-1 extract. Results suggest that these microalgae posses antioxidant potential which could be considered for future applications in medicine, dietary supplements, cosmetics or food industries.

  3. Synergistic Action of D-Glucose and Acetosyringone on Agrobacterium Strains for Efficient Dunaliella Transformation.

    Directory of Open Access Journals (Sweden)

    Ramachandran Srinivasan

    Full Text Available An effective transformation protocol for Dunaliella, a β-carotene producer, was developed using the synergistic mechanism of D-glucose and Acetosyringone on three different Agrobacterium strains (EHA105, GV3101 and LBA4404. In the present study, we investigated the pre-induction of Agrobacterium strains harboring pMDC45 binary vector in TAP media at varying concentrations of D-glucose (5 mM, 10 mM, and 15mM and 100 μM of Acetosyringone for co-cultivation. Induction of Agrobacterium strains with 10 mM D-glucose and 100 μM Acetosyringone showed higher rates of efficiency compared to other treatments. The presence of GFP and HPT transgenes as a measure of transformation efficiency from the transgenic lines were determined using fluorescent microscopy, PCR, and southern blot analyzes. Highest transformation rate was obtained with the Agrobacterium strain LBA4404 (181 ± 3.78 cfu per 106 cells followed by GV3101 (128 ± 5.29 cfu per 106 cells and EHA105 (61 ± 5.03 cfu per 106 cells. However, the Agrobacterium strain GV3101 exhibited more efficient single copy transgene (HPT transfer into the genome of D. salina than LBA4404. Therefore, future studies dealing with genetic modifications in D. salina can utilize GV3101 as an optimal Agrobacterium strain for gene transfer.

  4. Synergistic Action of D-Glucose and Acetosyringone on Agrobacterium Strains for Efficient Dunaliella Transformation.

    Science.gov (United States)

    Srinivasan, Ramachandran; Gothandam, Kodiveri Muthukalianan

    2016-01-01

    An effective transformation protocol for Dunaliella, a β-carotene producer, was developed using the synergistic mechanism of D-glucose and Acetosyringone on three different Agrobacterium strains (EHA105, GV3101 and LBA4404). In the present study, we investigated the pre-induction of Agrobacterium strains harboring pMDC45 binary vector in TAP media at varying concentrations of D-glucose (5 mM, 10 mM, and 15mM) and 100 μM of Acetosyringone for co-cultivation. Induction of Agrobacterium strains with 10 mM D-glucose and 100 μM Acetosyringone showed higher rates of efficiency compared to other treatments. The presence of GFP and HPT transgenes as a measure of transformation efficiency from the transgenic lines were determined using fluorescent microscopy, PCR, and southern blot analyzes. Highest transformation rate was obtained with the Agrobacterium strain LBA4404 (181 ± 3.78 cfu per 106 cells) followed by GV3101 (128 ± 5.29 cfu per 106 cells) and EHA105 (61 ± 5.03 cfu per 106 cells). However, the Agrobacterium strain GV3101 exhibited more efficient single copy transgene (HPT) transfer into the genome of D. salina than LBA4404. Therefore, future studies dealing with genetic modifications in D. salina can utilize GV3101 as an optimal Agrobacterium strain for gene transfer.

  5. Cytotoxicity evaluation of gold nanoparticles on microalga Dunaliella salina in microplate test system

    Science.gov (United States)

    Chumakov, Daniil; Prilepskii, Artur; Dykman, Lev; Khlebtsov, Boris; Khlebtsov, Nikolai; Bogatyrev, Vladimir

    2018-04-01

    Gold nanoparticles are intensively studied in biomedicine. Assessment of their biocompatibility is highly important. Currently there is lack of evidence, concerning nanotoxicity of ultrasmall gold nanoparticles < 5 nm. Existing data are rather contradictory. The aim of that study was to evaluate the toxicity of 2 nm colloidal gold, using microalga Dunaliella salina. Cellular barriers of that microalga are very similar to animal cells so it might be considered as a valuable model for nanotoxicity testing. Chlorophyll content as a test-function was used. Spectrophotometric method for chlorophyll determination in vivo in suspensions of D.salina cultures was applied. Calculated EC50 48h value of ionic gold was 25.8 +/- 0.3 mg Au/L. EC50 value of phosphine-stabilized gold nanoclusters was 32.2 +/-1.1 mg Au/L. It was not possible to calculate EC50 for 15 nm citrate gold nanoparticles, as they were non-toxic at all concentrations tested. These results are confirmed by fluorescent -microscopic monitoring of the same probes. It was shown that 10-fold growth of phosphine-stabilized gold nanoparticles (from 2.3 +/- 0.9 nm to 21.1 +/- 7.5 nm) led to 7-fold decrease of their toxicity.

  6. Bicarbonate-based cultivation of Dunaliella salina for enhancing carbon utilization efficiency.

    Science.gov (United States)

    Kim, Ga-Yeong; Heo, Jina; Kim, Hee-Sik; Han, Jong-In

    2017-08-01

    In this study, bicarbonate was proposed as an alternative carbon source to overcome exceedingly low CO 2 fixation efficiency of conventional microalgae cultivation system. 5gL -1 of sodium bicarbonate was found to well support the growth of Dunaliella salina, showing 2.84-fold higher specific growth rate than a bicarbonate-free control. This bicarbonate-fed cultivation also could yield biomass productivity similar to that of CO 2 -based system as long as pH was controlled. While the supplied CO 2 , because of its being a gas, was mostly lost and only 3.59% of it was used for biomass synthesis, bicarbonate was effectively incorporated into the biomass with 91.40% of carbon utilization efficiency. This study showed that the bicarbonate-based microalgae cultivation is indeed possible, and can even become a truly environment-friendly and workable approach, provided that a CO 2 mineralization technology is concomitantly established. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Metabolic responses and β-carotene production by the unicellular green alga Dunaliella salina exposed to leaf extracts

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    Alireza Einali

    Full Text Available ABSTRACT The present work investigated the effects of aqueous extracts of eucalyptus ( Eucalyptus globulus and elderberry ( Sambucus ebulus leaves on β-carotene productivity in Dunaliella salina, a green microalga. Leaf extracts from eucalyptus have greater amounts of phenolics and flavonoids, as well as greater ferric reducing antioxidant potential than elderberry. The extracts of both species greatly inhibited growth of algal suspensions. However, chlorophyll and β-carotene concentration increased in cells treated with leaf extracts, and the highest values were detected in 1 % eucalyptus and 2 % elderberry extracts. Fresh weight, total sugar, and protein content significantly increased following exposure of cells to different doses of leaf extracts. However, in doses containing more than 2 % eucalyptus, the upward trend for total sugar and protein ceased and remained statistically unchanged. These results suggest that metabolic modifications enable D. salina cells to tolerate the stress induced by the leaf extracts through allocating carbon flux to the synthesis of osmolytes and putative antioxidant molecules (e.g. sugars and β-carotene. Therefore, the use of leaf extracts holds potential to be a promising and effective way to improve D. salina cultivation for β-carotene production and other biotechnological and industrial applications.

  8. Evaluation of Culture Conditions to Obtain Fatty Acids from Saline Microalgae Species: Dunaliella salina, Sinecosyfis sp., and Chroomonas sp.

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    D. A. Castilla Casadiego

    2016-01-01

    Full Text Available The use of the saline microalgae, Dunaliella salina, Sinecosyfis sp., and Chroomonas sp., was explored as an alternative source for the production of fatty acids using fertilizer and glycerol as culture media. The nutrient medium used contained “Nutrifoliar,” a commercial fertilizer, and/or glycerol, in natural sea water. The microalgae were placed in cultures with different conditions. The parameters that favored the largest production of fatty acids were 24 hours of agitation and illumination, 1620 L/day of air supply, 2.25 L of air/min, and a temperature of 32°C using “Nutrifoliar” as the culture media. Results indicated that, from 3 g of microalgae in wet base of Chroomonas sp., 54.43 mg of oil was produced. The chromatographic characterization of oil obtained revealed the presence of essential fatty acids such as 9,12,15-octadecatrienoic acid (omega-3 and 4,7,10-hexadecatrienoic acid (omega-6 from the species Dunaliella salina. On the other hand, 9,12-octadecadienoic acid (omega-6 and cis-11-eicosenoic acid (omega-9 were identified from the species Chroomonas sp. The temperature variations played an important role in the velocity of growth or the production of the algae biomass, the amount of oil, and the ability to produce fatty acids.

  9. Toxicity and trophic transfer of P25 TiO2 NPs from Dunaliella salina to Artemia salina: Effect of dietary and waterborne exposure.

    Science.gov (United States)

    Bhuvaneshwari, M; Thiagarajan, Vignesh; Nemade, Prateek; Chandrasekaran, N; Mukherjee, Amitava

    2018-01-01

    The recent increase in nanoparticle (P25 TiO 2 NPs) usage has led to concerns regarding their potential implications on environment and human health. The food chain is the central pathway for nanoparticle transfer from lower to high trophic level organisms. The current study relies on the investigation of toxicity and trophic transfer potential of TiO 2 NPs from marine algae Dunaliella salina to marine crustacean Artemia salina. Toxicity was measured in two different modes of exposure such as waterborne (exposure of TiO 2 NPs to Artemia) and dietary exposure (NP-accumulated algal cells are used to feed the Artemia). The toxicity and accumulation of TiO 2 NPs in marine algae D. salina were also studied. Artemia was found to be more sensitive to TiO 2 NPs (48h LC 50 of 4.21mgL -1 ) as compared to marine algae, D. salina (48h LC 50 of 11.35mgL -1 ). The toxicity, uptake, and accumulation of TiO 2 NPs were observed to be more in waterborne exposure as compared to dietary exposure. Waterborne exposure seemed to cause higher ROS production and antioxidant enzyme (SOD and CAT) activity as compared to dietary exposure of TiO 2 NPs in Artemia. There were no observed biomagnification (BMF) and trophic transfer from algae to Artemia through dietary exposure. Histopathological studies confirmed the morphological and internal damages in Artemia. This study reiterates the possible effects of the different modes of exposure on trophic transfer potential of TiO 2 NPs and eventually the consequences on aquatic environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Metabolic studies with NMR spectroscopy of the alga Dunaliella salina trapped within agarose beads.

    Science.gov (United States)

    Bental, M; Pick, U; Avron, M; Degani, H

    1990-02-22

    A technique for the entrapment of the unicellular algae Dunaliella salina in agarose beads and their perfusion during NMR measurements is presented. The trapped cells maintained their ability to proliferate under normal growth conditions, and remained viable and stable under steady-state conditions for long periods during NMR measurements. Following osmotic shock in the dark, prominent changes were observed in the intracellular level of ATP and polyphosphates, but little to no changes in the intracellular pH or orthoposphate content. When cells were subjected to hyperosmotic shock, the ATP level decreased. The content of NMR-visible polyphosphates decreased as well, presumably due to the production of longer, NMR-invisible structures. Following hypoosmotic shock, the ATP content increased and longer polyphosphates were broken down to shorter, more mobile polymers.

  11. Setting the conditions for phycoremediation of radionuclide microalgae Dunaliella salina and Chlorella vulgaris

    International Nuclear Information System (INIS)

    Tatarova, D.; Galanda, D.; Kuruc, J.

    2016-01-01

    This presentation deals with bioremediation using microalgae - by phycoremediation. Microalgae are economically low profile compared to the plants, their cultivation can be carried out in laboratory conditions. They can survive in extreme conditions, they occur in all habitats and have faster growth. Halophilous green D. salina can accumulate heavy metals such as Zn, Cu and Cd. It occurs in hypersaline environment with tolerance (0.2 to 35) % NaCl. It contains high amounts of carotenoids, which protect it against formation of free radicals from UV radiation. Chlorella vulgaris is a representative of eukaryotic green microalgae with the highest chlorophyll content with the appearance in fresh water. Its phycoremediant ability are found in N and P elements, which are used as its nutritional components as well as for Cu, Cr, Cd, Pb, Au. The experiments were carried out using a peristaltic pump ISMATEC Model: ISM851 (flow rate 2 cm"3 min"-"1) followed by monitoring of time dependence of decrease of activity of the microalgae solutions. For evaluation of the samples was used HPGe gamma spectrometer (measurement time of the samples: 600 sec) from ORTEC Company and measured spectra were evaluated with software GammaVision from ORTEC. The measured results showed that the most effective phycoremediation of microalgae Dunaliella salina toke place in an environment of pH 3, and even more at pH 8. The fact that the D. salina is able of phycoremediation at so acidic pH can contribute to its applications in extreme conditions or in the coastal areas in view of that it is halophilic. At freshwater microalgae Chlorella vulgaris was found the best phytoremediation potential in its natural environment at pH of 6. Because this microalgae is freshwater, it may find application in inland or in liquid radioactive waste from nuclear facilities.(authors)

  12. Obtención de glicerol a partir de la Microalga Dunaliella Salina

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    Lisethy Hernández Nazario

    2000-08-01

    Full Text Available En el campo de la tecnología farmacéutica, el glicerol es un disolvente ampliamente utilizado en virtud de sus propiedades físico-químicas en la formulación de diferentes formas farmacéuticas. Se investigaron las posibilidades de obtención de glicerol como un subproducto del proceso de extracción de ß-carotenos a partir de cultivos de Dunaliella salina, desarrollados bajo régimen autotrófico en el Centro de Investigaciones de Energía Solar. El flujo tecnológico propuesto comprende el tratamiento de la biomasa con hidróxido de calcio, la filtración del producto resultante, la extracción del ß-carotenos con un solvente insoluble en agua y, por último, la separación del glicerol neutralizando convenientemente del filtrado con ácido. El rendimiento de glicerol fue del 4-5 %, valor susceptible de ser incrementado mediante la inducción metabólica de los cultivos.

  13. Salinity-Induced Palmella Formation Mechanism in Halotolerant Algae Dunaliella salina Revealed by Quantitative Proteomics and Phosphoproteomics

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    Sijia Wei

    2017-05-01

    Full Text Available Palmella stage is critical for some unicellular algae to survive in extreme environments. The halotolerant algae Dunaliella salina is a good single-cell model for studying plant adaptation to high salinity. To investigate the molecular adaptation mechanism in salinity shock-induced palmella formation, we performed a comprehensive physiological, proteomics and phosphoproteomics study upon palmella formation of D. salina using dimethyl labeling and Ti4+-immobilized metal ion affinity chromatography (IMAC proteomic approaches. We found that 151 salinity-responsive proteins and 35 salinity-responsive phosphoproteins were involved in multiple signaling and metabolic pathways upon palmella formation. Taken together with photosynthetic parameters and enzyme activity analyses, the patterns of protein accumulation and phosphorylation level exhibited the mechanisms upon palmella formation, including dynamics of cytoskeleton and cell membrane curvature, accumulation and transport of exopolysaccharides, photosynthesis and energy supplying (i.e., photosystem II stability and activity, cyclic electron transport, and C4 pathway, nuclear/chloroplastic gene expression regulation and protein processing, reactive oxygen species homeostasis, and salt signaling transduction. The salinity-responsive protein–protein interaction (PPI networks implied that signaling and protein synthesis and fate are crucial for modulation of these processes. Importantly, the 3D structure of phosphoprotein clearly indicated that the phosphorylation sites of eight proteins were localized in the region of function domain.

  14. LIPID PRODUCTION BY DUNALIELLA SALINA IN BATCH CULTURE: EFFECTS OF NITROGEN LIMITATION AND LIGHT INTENSITY

    Energy Technology Data Exchange (ETDEWEB)

    Weldy, C.S.; Huesemann, M.

    2007-01-01

    Atmospheric carbon dioxide (CO2) concentrations are increasing and may cause unknown deleterious environmental effects if left unchecked. The Intergovernmental Panel on Climate Change (IPCC) has predicted in its latest report a 2°C to 4°C increase in global temperatures even with the strictest CO2 mitigation practices. Global warming can be attributed in large part to the burning of carbon-based fossil fuels, as the concentration of atmospheric CO2 is directly related to the burning of fossil fuels. Biofuels which do not add CO2 to the atmosphere are presently generated primarily from terrestrial plants, i.e., ethanol from corn grain and biodiesel from soybean oil. The production of biofuels from terrestrial plants is severely limited by the availability of fertile land. Lipid production from microalgae and its corresponding biodiesel production have been studied since the late 1970s but large scale production has remained economically infeasible due to the large costs of sterile growing conditions required for many algal species. This study focuses on the potential of the halophilic microalgae species Dunaliella salina as a source of lipids and subsequent biodiesel production. The lipid production rates under high light and low light as well as nitrogen suffi cient and nitrogen defi cient culture conditions were compared for D. salina cultured in replicate photobioreactors. The results show (a) cellular lipid content ranging from 16 to 44% (wt), (b) a maximum culture lipid concentration of 450mg lipid/L, and (c) a maximum integrated lipid production rate of 46mg lipid/L culture*day. The high amount of lipids produced suggests that D. salina, which can be mass-cultured in non-sterile outdoor ponds, has strong potential to be an economically valuable source for renewable oil and biodiesel production.

  15. Effects of UV/Ag-TiO2/O3 advanced oxidation on unicellular green alga Dunaliella salina: implications for removal of invasive species from ballast water.

    Science.gov (United States)

    Wu, Donghai; You, Hong; Du, Jiaxuan; Chen, Chuan; Jin, Darui

    2011-01-01

    The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of effluent was determined. Compared with individual unit processes using ozone or UV/Ag-TiO2, the inactivation efficiency of D. salina by the combined UV/Ag-TiO2/O3 process was enhanced. The presence of ozone caused an immediate decrease in chlorophyll a (chl-a) concentration. Inactivation efficiency and ch1-a removal efficiency were positively correlated with ozone dose and ultraviolet intensity. The initial total residual oxidant (TRO) concentration of effluent increased with increasing ozone dose, and persistence of TRO resulted in an extended period of toxicity. The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment.

  16. Tolerance induction to stress caused by lavender (Lavandula angustifolia extracts in the microalga Dunaliella salina through metabolic modifications and β-carotene production

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    Sahar Mazang-Ghasemi

    2016-03-01

    Full Text Available The inhibitory or stimulatory effect of one plant on other plant species through the released chemical compounds into the environment, known as allelochemicals, is called allelopathy. In the present study, effect of aqueous extracts of lavender (Lavandula angustifolia leaves on growth pattern and ability of β-carotene production in unicellular green alga, Dunaliella salina was investigated. Based on these results, phenolics content and antioxidant capacity of the extracts was relatively low. Treated cultures with extract concentrations of 1, 2, 3 and 4 % showed that the process of cell division was ceased because of extracts phytotoxicity. However, the chlorophyll and β-carotene concentration pronouncedly increased in phytotoxin-treated cells, so that the highest of these values were detected in 3 % extracts-exposed cells. Percentage change of all three fresh weight, total sugar and protein between 0 and 48 h of phytotoxins treatment was significantly increased concurrently with increasing dose of extracts. These results suggest that D. salina tolerate allelochemicals-induced stress by metabolic modifications. Therefore, phytotoxins-tolerance mechanisms in D. salina are associated with physiological and metabolic adjustments by allocating the carbon flux to the synthesis of the sugars, chlorophyll and β-carotene, which induce phytotoxins stress tolerance in this alga.

  17. Cytotoxic activity of carotenoid rich fractions from Haematococcus pluvialis and Dunaliella salina microalgae and the identification of the phytoconstituents using LC-DAD/ESI-MS.

    Science.gov (United States)

    El-Baz, Farouk K; Hussein, Rehab A; Mahmoud, Khaled; Abdo, Sayeda M

    2018-02-01

    Microalgae represent a rich source that satisfies the growing need for novel ingredients of nutriceuticals, pharmaceuticals, and food supplements. Haematococcus pluvialis and Dunaliella salina microalgae are isolated from the Egyptian hydro-flora and are reported for their potent antioxidant activities. The cytotoxic activity of different fractions of both microalgae was investigated on 4 cell lines HePG2, MCF7, HCT116, and A549. The carotenoid rich fraction of H. pluvialis showed potent cytotoxic activity against colon cancer cell line and moderate activity against both liver and breast cancer cell lines. On the other hand, the carotenoid rich fraction of D. salina showed mild cytotoxic activity on breast and liver cancer cell lines. The carotenoid rich fraction of H. pluvialis was analysed using LC-DAD/ESI-MS and the major carotenoids were identified either free as well as bounded to fatty acids. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Transfer and accumulation of 106Ru from phytoplankton (Dunaliella bioculata) to zooplankton (Artemia salina)

    International Nuclear Information System (INIS)

    Izumo, Yoshiro; Takase, Akira

    1982-01-01

    106 Ru is one of the most abundant radionuclides to be released from the unclear-spent fuel reprocessing plant to oceans. This paper deals with transfer and accumulation of the radionuclide from phytoplankton (Dunaliella) to zooplankton (Artemia) in the graizing food chain of marine organisms. Each plankton was reared in the radioactive sea water A (filtrated and circulated through sandy mud, and the radioactive concentration decreased and atteined to constant after addition of 106 Ru), B (not filtrated and circulated, and the radioactive concentration decreased and atteined to constant) and C (not filtrated and circulated, the radioactive concentration decreased, but did not attein to constant), respectively, and investigated accumulations of 106 Ru. Then, accumulations of 106 Ru in Artemia by the ingestion of each diet (Dunaliella) contaminated with 106 Ru in each water, were investigated and compared with those from each water. Concentration factors of 106 Ru for the planktons reared in the radioactive sea waters were different among these waters. The difference can be attributable to that of physicochemical states of 106 Ru in the waters. It was found that 106 Ru would be accumulated by Artemia from the water A about 10 times higher than from the contaminated diet (Dunaliella) in this water, however from the contaminated diet (Dunaliella) in the water B about 2.2 times higher than from the last water. (author)

  19. Influence of PbS nanoparticle polymer coating on their aggregation behavior and toxicity to the green algae Dunaliella salina

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hajar [Department of Biology, Faculty of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Moradshahi, Ali, E-mail: moradshahi@susc.ac.ir [Department of Biology, Faculty of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Jahromi, Hamed Dehdashti; Sheikhi, Mohammad Hosein [Nanotechnology Research Institute, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

    2014-09-15

    Highlights: • Lead sulfide nanoparticles (PbS NPs) are toxic to D. salina. • Gum-Arabic coating alters the toxicity of PbS NPs. • Cell-NPs agglomerates and lipid peroxidation could explain the toxicity of PbS NPs. • Shading effect and dissolution do not seem to contribute to the toxicity of PbS NPs. • Particle–particle interaction was reduced by coating; therefore, PbS NPs were stabilized in the culture media. - Abstract: The potential hazards of nanoparticles (NPs) to the environment and to living organisms need to be considered for a safe development of nanotechnology. In the present study, the potential toxic effects of uncoated and gum Arabic-coated lead sulfide nanoparticles (GA-coated PbS NPs) on the growth, lipid peroxidation, reducing capacity and total carotenoid content of the hypersaline unicellular green algae Dunaliella salina were investigated. Coatings of PbS NPs with GA, as confirmed by Fourier transform infrared spectroscopy, reduced the toxicity of PbS NPs. Uncoated PbS NP toxicity to D. salina was attributed to higher algal cell-NP agglomerate formation, higher lipid peroxidation, lower content of total reducing substances and lower total carotenoid content. Low levels of Pb{sup 2+} in the growth culture media indicate that PbS NP dissolution does not occur in the culture. Also, the addition of 100 μM Pb{sup 2+} to the culture media had no significant (P > 0.05) effect on algal growth. The shading of light (shading effect) by PbS NPs, when simulated using activated charcoal, did not contribute to the overall toxic effect of PbS NPs which was evident by insignificant (P > 0.05) reduction in the growth and antioxidant capacity of the algae. When PbS NP aggregation in culture media (without algal cells) was followed for 60 min, uncoated form aggregated rapidly reaching aggregate sizes with hydrodynamic diameter of over 2500 nm within 60 min. Effective particle–particle interaction was reduced in the GA-coated NPs. Aggregates of about

  20. Influence of PbS nanoparticle polymer coating on their aggregation behavior and toxicity to the green algae Dunaliella salina

    International Nuclear Information System (INIS)

    Zamani, Hajar; Moradshahi, Ali; Jahromi, Hamed Dehdashti; Sheikhi, Mohammad Hosein

    2014-01-01

    Highlights: • Lead sulfide nanoparticles (PbS NPs) are toxic to D. salina. • Gum-Arabic coating alters the toxicity of PbS NPs. • Cell-NPs agglomerates and lipid peroxidation could explain the toxicity of PbS NPs. • Shading effect and dissolution do not seem to contribute to the toxicity of PbS NPs. • Particle–particle interaction was reduced by coating; therefore, PbS NPs were stabilized in the culture media. - Abstract: The potential hazards of nanoparticles (NPs) to the environment and to living organisms need to be considered for a safe development of nanotechnology. In the present study, the potential toxic effects of uncoated and gum Arabic-coated lead sulfide nanoparticles (GA-coated PbS NPs) on the growth, lipid peroxidation, reducing capacity and total carotenoid content of the hypersaline unicellular green algae Dunaliella salina were investigated. Coatings of PbS NPs with GA, as confirmed by Fourier transform infrared spectroscopy, reduced the toxicity of PbS NPs. Uncoated PbS NP toxicity to D. salina was attributed to higher algal cell-NP agglomerate formation, higher lipid peroxidation, lower content of total reducing substances and lower total carotenoid content. Low levels of Pb 2+ in the growth culture media indicate that PbS NP dissolution does not occur in the culture. Also, the addition of 100 μM Pb 2+ to the culture media had no significant (P > 0.05) effect on algal growth. The shading of light (shading effect) by PbS NPs, when simulated using activated charcoal, did not contribute to the overall toxic effect of PbS NPs which was evident by insignificant (P > 0.05) reduction in the growth and antioxidant capacity of the algae. When PbS NP aggregation in culture media (without algal cells) was followed for 60 min, uncoated form aggregated rapidly reaching aggregate sizes with hydrodynamic diameter of over 2500 nm within 60 min. Effective particle–particle interaction was reduced in the GA-coated NPs. Aggregates of about 440 nm

  1. Carotenogénesis de cinco cepas del alga Dunaliella sp. (Chlorophyceae aisladas de lagunas hipersalinas de Venezuela

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    Miguel Guevara

    2005-09-01

    Full Text Available Se realizaron cultivos discontinuos (medio Algal con 0.5 mM de NaNO3 y 27% de NaCl de cinco cepas de Dunaliella sp., aisladas de diferentes lagunas hipersalinas de Venezuela (Araya, Coche, Peonía, Cumaraguas y Boca Chica y una cepa de referencia (Dunaliella salina LB1644. Los bioensayos se mantuvieron a 25 ± 1 °C con aireación constante, fotoperiodo 12:12 y dos intensidades luminosas (195 y 390 µE.m-2.s-1 durante 30 días. El crecimiento celular se determinó diariamente mediante conteo celular en cámara de Neubaüer. La clorofila a y los carotenoides totales se analizaron al final del ensayo. Las mayores densidades celulares correspondieron a los ensayos de menor intensidad luminosa. La cepa que alcanzó la mayor densidad celular fue la aislada de Boca Chica (8 x10(6 y 2.5 x10(6 cel.ml-1 a 195 y 390 µE.m-2.s-1, respectivamente. El incremento de la intensidad luminosa en los cultivos produjo una disminución significativa de las tasas de crecimiento en todas las cepas. Los carotenoides totales por volumen fueron mayores a 390 µE.m-2 .s-1; siendo las cepas de referencia LB1644, Coche y Araya las que produjeron mayor cantidad (38.4; 32.8 y 21.0 µg.ml-1, respectivamente. El contenido de carotenoides totales por célula en los dos tratamientos fue significativamente diferente, obteniéndose la mayor concentración a 390 µE.m-2.s-1. Las cepas LB1644 y Coche fueron las que produjeron los valores más altos de carotenos (137.14 y 106.06 pg.cel-1, respectivamente. La cepa LB1644 presentó la mayor relación carotenoides totales:clorofila a (20:1 a 195 µE.m-2.s-1, mientras que en la cepa Coche no se evidenciaron diferencias significativas entre las dos intensidades (15:1. El resto de las cepas mostraron relaciones inferiores a uno. Nuestros resultados sugieren que las cepas Coche y Araya pueden ser potencialmente utilizadas en la biotecnología de producción de carotenoides.Carotenogenesis of five strains of the algae Dunaliella sp

  2. Proteomic analysis of halotolerant proteins under high and low salt stress in Dunaliella salina using two-dimensional differential in-gel electrophoresis

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    Yan-Long Jia

    2016-01-01

    Full Text Available Abstract Dunaliella salina, a single-celled marine alga with extreme salt tolerance, is an important model organism for studying fundamental extremophile survival mechanisms and their potential practical applications. In this study, two-dimensional differential in-gel electrophoresis (2D-DIGE was used to investigate the expression of halotolerant proteins under high (3 M NaCl and low (0.75 M NaCl salt concentrations. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS and bioinformatics were used to identify and characterize the differences among proteins. 2D-DIGE analysis revealed 141 protein spots that were significantly differentially expressed between the two salinities. Twenty-four differentially expressed protein spots were successfully identified by MALDI-TOF/TOF MS, including proteins in the following important categories: molecular chaperones, proteins involved in photosynthesis, proteins involved in respiration and proteins involved in amino acid synthesis. Expression levels of these proteins changed in response to the stress conditions, which suggests that they may be involved in the maintenance of intracellular osmotic pressure, cellular stress responses, physiological changes in metabolism, continuation of photosynthetic activity and other aspects of salt stress. The findings of this study enhance our understanding of the function and mechanisms of various proteins in salt stress.

  3. ROS and calcium signaling mediated pathways involved in stress responses of the marine microalgae Dunaliella salina to enhanced UV-B radiation.

    Science.gov (United States)

    Zhang, Xinxin; Tang, Xuexi; Wang, Ming; Zhang, Wei; Zhou, Bin; Wang, You

    2017-08-01

    UV-B ray has been addressed to trigger common metabolic responses on marine microalgae, however, the upstream events responsible for these changes in marine microalgae are poorly understood. In the present study, a species of marine green microalgae Dunaliella salina was exposed to a series of enhanced UV-B radiation ranging from 0.25 to 1.00 KJ·m -2 per day. The role of ROS and calcium signaling in the D. salina responses to UV-B was discussed. Results showed that enhanced UV-B radiation markedly decreased the cell density in a dose-dependent manner, but the contents of protein and glycerol that were essential for cell growth increased. It suggested that it was cell division instead of cell growth that UV-B exerted negative effects on. The subcellular damages on nuclei and plasmalemma further evidenced the hypothesis. The nutrient absorption was affected with UV-B exposure, and the inhibition on PO 4 3- uptake was more serious compared to NO 3 - uptake. UV-B radiation promoted reactive oxygen species (ROS) formation and thiobarbituric acid reactive substances (TBARS) contents, decreased the redox status and altered the antioxidant enzyme activities. The addition of the ROS scavenger and the glutathione biosynthesis precursor N-acetyl-l-cysteine (NAC) alleviated the stress degree, implying ROS-mediated pathway was involved in the stress response to UV-B radiation. Transient increase in Ca 2+ -ATPase was triggered simultaneously with UV-B exposure. Meanwhile, the addition of an intracellular free calcium chelator aggravated the damage of cell division, but exogenous calcium and ion channel blocker applications did not, inferring that endogenously initiated calcium signaling played roles in response to UV-B. Cross-talk analysis showed a relatively clear relationship between ROS inhibition and Ca 2+ -ATPase suppression, and a relation between Ca 2+ inhibition and GPx activity change was also observed. It was thus presumed that ROS-coupled calcium signaling via the

  4. A systematic correlation analysis of carotenoids, chlorophyll, non-pigmented cell mass, and cell number for the blueprint of Dunaliella salina culture in a photobioreactor.

    Science.gov (United States)

    Song, Hyeon Gi; Byeon, Seon Yeong; Chung, Goo Yong; Jung, Sang-Myung; Choi, Jung Il; Shin, Hwa Sung

    2018-05-28

    Microalgal carotenoids are attractive health ingredients, but their production should be optimized to improve cost-effectiveness. Understanding cellular physiology centered on carotenoid synthesis is the prerequisite for this work. Therefore, systematic correlation analyses were conducted among chlorophyll, carotenoids, non-pigmented cell mass, and cell number of Dunaliella salina in a specified condition over a relatively long culture time. First, an integrated correlation was performed: a temporal profile of the carotenoids was correlated with those of other factors, including chlorophyll, non-pigmented cell mass, and cell number. Pearson and Spearman correlation analyses were performed to identify linearity and monotonicity of the correlation, respectively, and then cross-correlation was executed to determine if the correlation had a time lag. Second, to understand the cellular potential of metabolism, the procedure was repeated to provide a data set composed of the specific synthesis rates of the factors or growth rate, which additionally provided kinetic correlations among the constituting components of the cell, excluding the effect of cell number. This systematic approach could generate a blueprint model that is composed of only what it needs, which could make it possible to efficiently control and optimize the process.

  5. Proteomic Analyses Reveal the Mechanism of Dunaliella salina Ds-26-16 Gene Enhancing Salt Tolerance in Escherichia coli.

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    Yanlong Wang

    Full Text Available We previously screened the novel gene Ds-26-16 from a 4 M salt-stressed Dunaliella salina cDNA library and discovered that this gene conferred salt tolerance to broad-spectrum organisms, including E. coli (Escherichia coli, Haematococcus pluvialis and tobacco. To determine the mechanism of this gene conferring salt tolerance, we studied the proteome of E. coli overexpressing the full-length cDNA of Ds-26-16 using the iTRAQ (isobaric tags for relative and absolute quantification approach. A total of 1,610 proteins were identified, which comprised 39.4% of the whole proteome. Of the 559 differential proteins, 259 were up-regulated and 300 were down-regulated. GO (gene ontology and KEGG (Kyoto encyclopedia of genes and genomes enrichment analyses identified 202 major proteins, including those involved in amino acid and organic acid metabolism, energy metabolism, carbon metabolism, ROS (reactive oxygen species scavenging, membrane proteins and ABC (ATP binding cassette transporters, and peptidoglycan synthesis, as well as 5 up-regulated transcription factors. Our iTRAQ data suggest that Ds-26-16 up-regulates the transcription factors in E. coli to enhance salt resistance through osmotic balance, energy metabolism, and oxidative stress protection. Changes in the proteome were also observed in E. coli overexpressing the ORF (open reading frame of Ds-26-16. Furthermore, pH, nitric oxide and glycerol content analyses indicated that Ds-26-16 overexpression increases nitric oxide content but has no effect on glycerol content, thus confirming that enhanced nitric oxide synthesis via lower intercellular pH was one of the mechanisms by which Ds-26-16 confers salt tolerance to E. coli.

  6. Efeito do meio Erd Schreiber no cultivo das microalgas Dunaliella salina, Tetraselmis chuii e Isochrysis galbana = Erd Schreiber medium effect in culture of microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana

    Directory of Open Access Journals (Sweden)

    Vera Lucia Mota Klein

    2006-04-01

    Full Text Available As microalgas são utilizadas como fonte de alimento em aqüicultura. Neste trabalho cultivaram-se D. salina, T. chuii e I. galbana. O objetivo do trabalho consistiu em determinar o efeito do meio Erd Schreiber sobre o seu crescimento. Iniciou-se o cultivo com a mistura de 200 mg de Na2HPO4,7H2O, 100 mg de NaNO3 e 50 mL de extrato de solo. No monitoramento, manteve-se a temperatura entre 24 - 28 oC, a salinidade a 34 ppt, à iluminação constante, a densidade celular com uma câmara de Neubauer e um microscópio binocular modelo ZEISS. Como resultado, I. galbana, D. salina e T. chuii atingiram 969 104 cel/mL, 457 x 104 cel/mL e 258,66 x 104 cel/mL, respectivamente, e oscoeficientes angulares b foram 3,76 x 104 cel./mL/dia, 6,84 x 104 cel./mL/dia e 2,08 x 104 cel./mL/dia respectivamente, indicando bom desempenho de todas as microalgas no meio Erd Shreiber.The microalgae is used as food source in aqüicultura. In this work they had cultivated D. salina , T. chuii and I. galbana . The objective of the work is to determine the effect of Erd Schreiber´s culture medium on the microalgae growth. The culture initiated mixting 200mg of Na2HPO4,7H2O, 100 mg of NaNO3 and 50 mL of soil extract. During the culture the temperature had varied between 24 and 28oC, the salinity was fixed on 34 %o, and the illumination was maintained constant. The assessment of the culture was made by a chamber of Neubauer and a binocular microscope ZEISS model. As result I. galbana D. salina and T.chuii reached 969 104 cel/mL, 457 x 104cel/mL and 258,66 x 104 cel/mL respectively and as angular coefficient 3,76 x 104 cel/mL/dia, 6,84 x 104 cel/mL/dia and 2,08 104 x cel/mL/dia respectively, showing good answer of the microalgae to the effect of Erd Schreiber´ s medium.

  7. Comparative Salt Stress Study on Intracellular Ion Concentration in Marine and Salt-adapted Freshwater Strains of Microalgae

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad TALEBI

    2013-08-01

    Full Text Available Salinity imposes significant stresses in various living organisms including microalgae. High extracellular concentration of Na+ directly influences ionic balance inside the cell and subsequently the cellular activities. In the present study, the effect of such stress on growth and intracellular ions concentration (IIC of Dunaliella salina and Chlorella Spp. was investigated. IIC was analyzed using Ion chromatography technique. D. salina showed the highest degree of resistance to increase in salinity as little changes occurred both in IIC and in growth parameters. D. salina could maintain the balance of K+ inside the cell and eject the excess Na+ even at NaCl concentrations above 1M. Moreover, D. salina accumulated β-carotene in order to protect its photosynthetic apparatus. Among Chlorella species, C. vulgaris showed signs of adaptation to high content of salinity, though it is a fresh water species by nature. Moreover, the response shown by C. vulgaris to rise in salinity was even stronger than that of C. salina, which is presumably a salt-water resistant species. In fact, C. vulgaris could maintain intracellular K+ better than C. salina in response to increasing salinity, and as a result, it could survive at NaCl concentrations as high as 0.75 M. Marine strains such as D. salina well cope with the fluctuations in salinity through the existing adaptation mechanisms i.e. maintaining the K+/N+ balance inside the cell, K+ accumulation and Na+ ejection, accumulation of photosynthetic pigments like β-carotene.

  8. Can the halophilic ciliate Fabrea salina be used as a bio-control of microalgae blooms in solar salterns?

    Science.gov (United States)

    Hong, Hyun Pyo; Choi, Joong Ki

    2015-09-01

    The microlage Dunaliella salina, a major producer in salterns, is a serious problem for salt production. In this study we tried to assess if Fabrea salina can control D. salina. By parameterising numerical and functional response (growth and grazing vs prey abundance, respectively) at 90 psu and 30°C, where the ciliate is abundant and grows well, we developed a predator-prey model. The model is used to explore how change in microalga growth rate affect the dynamics, and the functional response is used in combination with field data to assess the potential impact of F. salina on D. salina. Over the 20 d simulation the ciliate controlled the prey population under all prey growth rates; although once D. salina were exhausted below the threshold level, F. salina died due to starvation, allowing the alga to increase in abundance, resulting in one or two predatorprey cycle, depending on prey growth rate. In general, the model predicted trends observed by others in the field, suggesting that it provided a good prediction of what may occur under the conditions we examined. Likewise we show that the ciliate can have a high impact on microalgal populations in the field. Finally, a literature review indicated that F. salina could be a good competitor with other protozoa and metazoan in salterns, depending on salinity and temperature, which requires further study and attention. In summary, we encourage continued studies on this unique ciliate on solar salterns and suggest that it may be useful in the bio-control of micoalgae.

  9. Development of a Dunaliella tertiolecta Strain with Increased Zeaxanthin Content Using Random Mutagenesis.

    Science.gov (United States)

    Kim, Minjae; Ahn, Junhak; Jeon, Hancheol; Jin, EonSeon

    2017-06-21

    Zeaxanthin is a xanthophyll pigment that is regarded as one of the best carotenoids for the prevention and treatment of degenerative diseases. In the worldwide natural products market, consumers prefer pigments that have been produced from biological sources. In this study, a Dunaliella tertiolecta strain that has 10-15% higher cellular zeaxanthin content than the parent strain ( zea1 ), was obtained by random mutagenesis using ethyl methanesulfonate (EMS) as a mutagen. This mutant, mp3 , was grown under various salinities and light intensities to optimize culture conditions for zeaxanthin production. The highest cellular zeaxanthin content was observed at 1.5 M NaCl and 65-85 μmol photons·m -2 ·s -1 , and the highest daily zeaxanthin productivity was observed at 0.6 M NaCl and 140-160 μmol photons·m -2 ·s -1 . The maximal yield of zeaxanthin from mp3 in fed-batch culture was 8 mg·L -1 , which was obtained at 0.6 M NaCl and 140-160 μmol photons·m -2 ·s -1 . These results suggest that random mutagenesis with EMS is useful for generating D. tertiolecta strains with increased zeaxanthin content, and also suggest optimal culture conditions for the enhancement of biomass and zeaxanthin production by the zeaxanthin accumulating mutant strains.

  10. Selection of microalgae and cyanobacteria strains for bicarbonate-based integrated carbon capture and algae production system.

    Science.gov (United States)

    Chi, Zhanyou; Elloy, Farah; Xie, Yuxiao; Hu, Yucai; Chen, Shulin

    2014-01-01

    Using microalgae to capture CO2 from flue gas is an ideal way to reduce CO2 emission, but this is challenged by the high cost of carbon capture and transportation. To address this problem, a bicarbonate-based integrated carbon capture and algae production system (BICCAPS) has been proposed, in which bicarbonate is used for algae culture, and the regenerated carbonate from this process can be used to capture more CO2. High-concentration bicarbonate is obligate for the BICCAPS. Thus, different strains of microalgae and cyanobacteria were tested in this study for their capability to grow in high-concentration NaHCO3. The highest NaHCO3 concentrations they are tolerant to were determined as 0.30 M for Synechocystis sp. PCC6803, 0.60 M for Cyanothece sp., 0.10 M for Chlorella sorokiniana, 0.60 M for Dunaliella salina, and 0.30 M for Dunaliella viridis and Dunaliella primolecta. In further study, biomass production from culture of D. primolecta in an Erlenmeyer flask with either 0.30 M NaHCO3 or 2 % CO2 bubbling was compared, and no significant difference was detected. This indicates BICCAPS can reach the same biomass productivity as regular CO2 bubbling culture, and it is promising for future application.

  11. Manipulation of carbon flux into fatty acid biosynthesis pathway in Dunaliella salina using AccD and ME genes to enhance lipid content and to improve produced biodiesel quality

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad Talebi

    2014-08-01

    Full Text Available Advanced generations of biofuels basically revolve around non-agricultural energy crops. Among those, microalgae owing to its unique characteristics i.e. natural tolerance to waste and saline water, sustainable biomass production and high lipid content (LC, is regarded by many as the ultimate choice for the production of various biofuels such as biodiesel. In the present study, manipulation of carbon flux into fatty acid biosynthesis pathway in Dunaliella salina was achieved using pGH plasmid harboring AccD and ME genes to enhance lipid content and to improve produced biodiesel quality. The stability of transformation was confirmed by PCR after several passages. Southern hybridization of AccD probe with genomic DNA revealed stable integration of the cassette in the specific positions in the chloroplast genome with no read through transcription by indigenous promoters. Comparison of the LC and fatty acid profile of the transformed algal cell line and the control revealed the over-expression of the ME/AccD genes in the transformants leading to 12% increase in total LC and significant improvements in biodiesel properties especially by increasing algal oil oxidation stability. The whole process successfully implemented herein for transforming algal cells by genes involved in lipid production pathway could be helpful for large scale biodiesel production from microalgae.

  12. ASI: Dunaliella marine microalgae to drop-in replacement liquid transportation fuel

    KAUST Repository

    Wang, Weicheng

    2013-09-11

    Microalgae are a promising biofuels feedstock, theoretically yielding concentrations of triacylglycerides (TAGs) per unit area that are far higher than traditional feedstocks due to their rapid growth. Dunaliella is particularly advantageous as a feedstock because it is currently commercially mass cultured, thrives in salt water, and has no cell wall. Fourteen strains of Dunaliella have been investigated for growth rates and lipid production in mass culture and tested for enhanced lipid production under a range of environmental stressors including salinity, pH, nitrogen and phosphorus limitation, and light regime. The nuclear genome has been sequenced for four of these strains, with the objective of increasing carbon flux through genetic engineering. Electroflocculation followed by osmotic membrane rupturing may be a very energy and cost efficient means of harvesting the lipid bodies from Dunaliella. A technically feasible and scalable thermo-catalytic process to convert the lipids into replacements for liquid transportation fuels has been developed. The lipids were converted into long-chain alkanes through continuous thermal hydrolysis followed by fed-batch thermo-catalytic decarboxylation. These alkanes can be reformed into renewable diesel via conventional catalytic hydrocarbon isomerization reactions to improve cold flow properties, if desired. © 2013 American Institute of Chemical Engineers Environ Prog, 32: 916-925, 2013 Copyright © 2013 American Institute of Chemical Engineers Environ Prog.

  13. ASI: Dunaliella marine microalgae to drop-in replacement liquid transportation fuel

    KAUST Repository

    Wang, Weicheng; Allen, Elle H.; Campos, Andrew A.; Cade, Rushyannah Killens; Dean, Lisa L.; Dvora, Mia; Immer, Jeremy G.; Mixson, Stephanie M.; Srirangan, Soundarya; Sauer, Marie Laure; Schreck, Steven D.; Sun, Keyi; Thapaliya, Nirajan; Wilson, Cameron W.; Burkholder, Joann M M; Grunden, Amy M.; Lamb, Henry Henry; Winter, Heike Winter; Stikeleather, Larry F.; Roberts, William L.

    2013-01-01

    Microalgae are a promising biofuels feedstock, theoretically yielding concentrations of triacylglycerides (TAGs) per unit area that are far higher than traditional feedstocks due to their rapid growth. Dunaliella is particularly advantageous as a feedstock because it is currently commercially mass cultured, thrives in salt water, and has no cell wall. Fourteen strains of Dunaliella have been investigated for growth rates and lipid production in mass culture and tested for enhanced lipid production under a range of environmental stressors including salinity, pH, nitrogen and phosphorus limitation, and light regime. The nuclear genome has been sequenced for four of these strains, with the objective of increasing carbon flux through genetic engineering. Electroflocculation followed by osmotic membrane rupturing may be a very energy and cost efficient means of harvesting the lipid bodies from Dunaliella. A technically feasible and scalable thermo-catalytic process to convert the lipids into replacements for liquid transportation fuels has been developed. The lipids were converted into long-chain alkanes through continuous thermal hydrolysis followed by fed-batch thermo-catalytic decarboxylation. These alkanes can be reformed into renewable diesel via conventional catalytic hydrocarbon isomerization reactions to improve cold flow properties, if desired. © 2013 American Institute of Chemical Engineers Environ Prog, 32: 916-925, 2013 Copyright © 2013 American Institute of Chemical Engineers Environ Prog.

  14. SALT EFFECTS ON SWARMERS OF DUNALIELLA VIRIDIS TEOD

    Science.gov (United States)

    Baas-Becking, L. G. M.

    1931-01-01

    1. Dunaliella viridis Teodoresco thrives equally well in solutions of NaCl 1 to 4 mol and pH 6 to 9. 2. The organism is sensitive to calcium and magnesium, especially in acid medium. 3. Calcium and magnesium are antagonistic. In a molar solution of NaCl the antagonistic relation Mg:Ca is 4 to 5. In a 4 molar solution of NaCl the proportion becomes many times as great (20:1). 4. Although the strains used in this investigation did not occur in sea water concentrates, the increase in the antagonistic ratio Mg:Ca in which they can live closely paralleled the changes in this ratio which take place when sea water evaporates. 5. The other organisms which occurred in the cultures each show a specific relation to Ca and Mg. 6. The size of the cells of Dunaliella does not decrease with increasing NaCl content. PMID:19872621

  15. Screening for unicellular algae as possible bioassay organisms for monitoring marine water samples.

    Science.gov (United States)

    Millán de Kuhn, Rosmary; Streb, Christine; Breiter, Roman; Richter, Peter; Neesse, Thomas; Häder, Donat-Peter

    2006-08-01

    ECOTOX is an automatic early warning system to monitor potential pollution of freshwater, municipal or industrial waste waters or aquatic ecosystems. It is based on a real time image analysis of the motility and orientation parameters of the unicellular, photosynthetic flagellate Euglena gracilis. In order to widen the use of the device to marine habitats and saline waters nine marine flagellates were evaluated as putative bioassay organisms, viz. Dunaliella salina, Dunaliella viridis, Dunaliella bardawil, Prorocentrum minimum Kattegat, P. minimum Lissabon, Tetraselmis suecica, Heterocapsa triquetra, Gyrodinium dorsum and Cryptomonas maculata. Because of their slow growth the last three strains were excluded from further evaluation. Selection criteria were ease of culture, density of cell suspension, stability of motility and gravitactic orientation. The sensitivity toward toxins was tested using copper(II) ions. The instrument allows the user to automatically determine effect-concentration (EC) curves from which the EC(50) values can be calculated. For the interpretation of the EC curves a sigmoid logistic model was proposed which proved to be satisfactory for all tested strains. The inhibition of the motility was considered as the most appropriate movement parameter as an endpoint. The Dunaliella species had the lowest sensitivity to copper with EC(50) values of 220, 198 and 176 mg/L for D. salina, D. bardawil and D. viridis, respectively, followed by T. suecica with an EC(50) value of 40 mg/L. The Prorocentrum species were found to be the most sensitive with an EC(50) value of 13.5 mg/L for P. minimum Lissabon and 7.5 mg/L for P. minimum Kattegat.

  16. Salinas : theory manual.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Reese, Garth M.; Bhardwaj, Manoj Kumar

    2004-08-01

    This manual describes the theory behind many of the constructs in Salinas. For a more detailed description of how to use Salinas , we refer the reader to Salinas, User's Notes. Many of the constructs in Salinas are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Salinas are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programer-notes manual, the user's notes and of course the material in the open literature.

  17. Salinas : theory manual.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Reese, Garth M.; Bhardwaj, Manoj Kumar

    2011-11-01

    Salinas provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Salinas. For a more detailed description of how to use Salinas, we refer the reader to Salinas, User's Notes. Many of the constructs in Salinas are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Salinas are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature.

  18. Effects of sonication and advanced chemical oxidants on the unicellular green alga Dunaliella tertiolecta and cysts, larvae and adults of the brine shrimp Artemia salina: a prospective treatment to eradicate invasive organisms from ballast water.

    Science.gov (United States)

    Gavand, Meghana R; McClintock, James B; Amsler, Charles D; Peters, Robert W; Angus, Robert A

    2007-11-01

    Uptake and release of ship-borne ballast water is a major factor contributing to introductions of aquatic phytoplankton and invasive macroinvertebrates. Some invasive unicellular algae can cause harmful algal blooms and produce toxins that build up in food chains. Moreover, to date, few studies have compared the efficacy of ballast water treatments against different life history phases of aquatic macroinvertebrates. In the present study, the unicellular green alga Dunaliella tertiolecta, and three discrete life history phases of the brine shrimp Artemia salina, were independently used as model organisms to study the efficacy of sonication as well as the advanced oxidants, hydrogen peroxide and ozone, as potential ballast water treatments. Algal cells and brine shrimp cysts, nauplii, and adults were subjected to individual and combined treatments of sonication and advanced oxidants. Combined rather than individual treatments consistently yielded the highest levels of mortality in algal cells (100% over a 2 min exposure) and in brine shrimp (100% and 95% for larvae and adults, respectively, over a 2 min exposure). In contrast, mortality levels in brine shrimp cysts (66% over 2 min; increased to 92% over a 20 min exposure) were moderately high but consistently lower than that detected for larval or adult shrimp. Our results indicate that a combination of sonication and advanced chemical oxidants may be a promising method to eradicate aquatic unicellular algae and macroinvertebrates in ballast water.

  19. Salinas. Theory Manual Version 2.8

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Garth M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walsh, Timothy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bhardwaj, Manoj K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2009-02-01

    Salinas provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Salinas. For a more detailed description of how to use Salinas , we refer the reader to Salinas, Users Notes. Many of the constructs in Salinas are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Salinas are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature.

  20. Phycoremediation of 137Cs and 60Co with selected species of aquatic microalgae

    International Nuclear Information System (INIS)

    Tatarova, D.; Galanda, D.; Strisovska, J.

    2016-01-01

    The presentation is focused on finding a suitable pH for phycoremediation of 137 Cs and 60 Co w ith microalgae Dunaliella salina and Chlorella vulgaris. To ensure a dynamic course of remediation the peristaltic pump was used, through which the solution was washed with radionuclides. During individual measurements the decrease in solution activity over time was monitored . Decline in activity in the samples was determined using a semiconductor HPGe gamma detector. The measured results showed that the best environment for phycoremediation for microalgae Dunaliella salina was at pH = 8 and less, for Chlorella vulgaris the best value was pH = 6. (authors)

  1. Amino Acids Are an Ineffective Fertilizer for Dunaliella spp. Growth

    Directory of Open Access Journals (Sweden)

    Colin A. Murphree

    2017-05-01

    Full Text Available Autotrophic microalgae are a promising bioproducts platform. However, the fundamental requirements these organisms have for nitrogen fertilizer severely limit the impact and scale of their cultivation. As an alternative to inorganic fertilizers, we investigated the possibility of using amino acids from deconstructed biomass as a nitrogen source in the genus Dunaliella. We found that only four amino acids (glutamine, histidine, cysteine, and tryptophan rescue Dunaliella spp. growth in nitrogen depleted media, and that supplementation of these amino acids altered the metabolic profile of Dunaliella cells. Our investigations revealed that histidine is transported across the cell membrane, and that glutamine and cysteine are not transported. Rather, glutamine, cysteine, and tryptophan are degraded in solution by a set of oxidative chemical reactions, releasing ammonium that in turn supports growth. Utilization of biomass-derived amino acids is therefore not a suitable option unless additional amino acid nitrogen uptake is enabled through genetic modifications of these algae.

  2. Pedro Salinas y el teatro desde dentro (Pedro Salinas and Theatre from Within

    Directory of Open Access Journals (Sweden)

    Yolanda Benítez Vega

    2013-12-01

    Full Text Available Resumen: Pedro Salinas y el teatro, desde dentro” es el título de este artículo cuya finalidad consiste en realizar un recorrido por la vocación teatral de Pedro Salinas desde sus primeros años hasta el final de sus días: su asistencia a representaciones teatrales, sus contactos con el teatro y sus proyectos como autor dramático tanto los que se realizaron como los que no llegaron a materializarse. El propósito es adentrarnos en el alma teatral del poeta: cómo, cuándo, por qué surge su vocación por el arte escénico, insistiendo en la necesidad de rescatar la faceta de dramaturgo de Pedro Salinas como una constante más en la labor del poeta, profesor y crítico.Abstract: "Pedro Salinas and the theatre, from inside " it is the title of this article which purpose consists of realizing a tour for Pedro Salinas's theatrical vocation from his first years until the end of his days: his assistance to theatrical representations, his contacts with the theatre and his projects like dramatic author so much those who were realized as those who did not manage to materialize. The intention is to enter the theatrical soul of the poet: how, when, why his vocation arises for the scenic art, insisting on the need to rescue the playwright's facet of Pedro Salinas as one more constant in the labor of the poet, teacher and critic.

  3. Understanding Environmental Factors that Affect Violence in Salinas, California

    Science.gov (United States)

    2009-12-01

    the lettuce produced in the United States is grown there, earning the Salinas Valley the nickname “Salad Bowl of the World.”1 The agricultural...1 City of Salinas, “ History of Salinas,” http://www.ci.salinas.ca.us/visitors/history.cfm. 2 State of the Cities...Chief of Police Louis Fetherolf reviewed the history of gang problems in Salinas. Highlights included: gang fights reaching ‘epidemic

  4. Development of harvesting and up concentration technologies for microalgae as an ingredient in fish feed

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

    2014-01-01

    andfish oil. In applications of algae in fish feed, it is essential to produce a product comparable to fish proteinand fish oil both in terms of quality and costs.Downstream processing of microalgae includes harvest, dewatering, cell rupture, fractionation and drying.The dewatering and drying which...... ingredients forfish feed. Further we evaluate the chemical composition of six different microalgae species including;Nanochloropsis limnethica, Chlorella sorokiniana, Phaeodactylum tinctorium, Dunaliella salina,Nannochloropsis salina and Nannochloropsis occulata ....

  5. Different strategies of osmoadaptation in the closely related marine myxobacteria Enhygromyxa salina SWB007 and Plesiocystis pacifica SIR-1.

    Science.gov (United States)

    Amiri Moghaddam, Jamshid; Boehringer, Nils; Burdziak, Amal; Kunte, Hans-Jörg; Galinski, Erwin A; Schäberle, Till F

    2016-02-03

    Only a few myxobacteria are known to date which are classified as marine due to their salt-dependency. In this study, the salt tolerance mechanism of these bacteria was investigated. Therefore, a growth medium was designed, in which the mutated Escherichia coli strain BKA13 served as sole food source for the predatory, heterotrophic myxobacteria. This enabled measurement of the osmolytes without any background and revealed that the closely related strains Enhygromyxa salina SWB007 and Plesiocystis pacifica SIR-1 developed different strategies to handle salt stress. P. pacifica SIR-1, which was grown between 1-4 % NaCl, relies solely on the accumulation of amino acids, while E. salina SWB007, which was grown between 0.5-3 % NaCl, employs, beside betaine, hydroxyectoine as the major compatible solute. In accordance with this analysis, only in the latter strain a gene locus was identified which codes for genes corresponding to the biosynthesis of betaine, ectoine, and hydroxyectoine.

  6. Crime Trend Prediction Using Regression Models for Salinas, California

    Science.gov (United States)

    2012-06-01

    2 1. History of Violence in Salinas ................................................. 2 2. Current and Past Efforts to...BACKGROUND 1. History of Violence in Salinas Small tribes of Native Americans inhabited the City of Salinas until around 1822. In 1822, Mexico...In the 1920s, sugar beets and beans gave way to the farming of lettuce because of the ice bunkered railroad, allowing fresh produce shipment

  7. Selective accumulation of organically bound tritium in the marine unicellular algae Dunaliella bioculata and Acetabularia mediterranea

    International Nuclear Information System (INIS)

    Strack, S.; Kirchmann, R.; Luettke, A.; Bonotto, S.

    1983-01-01

    The marine unicellular algae Dunaliella bioculata and Acetabularia mediterranea have been used to assess the importance of the radioactive contamination by 3 H bound to different organic molecules. We have studied the uptake of 10 different tritiated substances, which are precursors for the cells' main macromolecules: thymidine-methyl- 3 H, adenine-2- 3 H, uridine-5- 3 H, L-leucine-4- 3 H, glycine-2- 3 H, L-arginine-3.4- 3 H, L-aspartic acid-2.3- 3 H, L-phenylalanine-2.3- 3 H, D-glucose-2- 3 H and D-glucose-6- 3 H. Under our experimental conditions, all the tritiated organic molecules are taken up by both algal species. Their intracellular concentration may reach that of the external medium. However, some molecules are selectively accumulated: adenine and leucine in Dunaliella, adenine, arginine and glucose in Acetabularia. Increasing concentrations of adenine and leucine, supplied to the cultures of Dunaliella seem to be without effect on the growth of the algae. (author)

  8. Plastid Regulation of Lhcb1 Transcription in the Chlorophyte Alga Dunaliella tertiolecta

    Czech Academy of Sciences Publication Activity Database

    Chen, Yi-Bu; Durnford, D. G.; Koblížek, Michal; Falkowski, P. G.

    2004-01-01

    Roč. 136, - (2004), s. 3737-3750 ISSN 0032-0889 Institutional research plan: CEZ:AV0Z5020903 Keywords : Lhcb1 * dunaliella tertiolecta Subject RIV: EE - Microbiology, Virology Impact factor: 5.881, year: 2004

  9. Monitoring of uncultured Dunaliella sp. in an Egyptian solar saltern ...

    African Journals Online (AJOL)

    Culture-independent molecular approach was used to explore and evaluate the diversity of Dunaliella species living at the salt field Malahat El-Max Alexandria, Egypt. Bulk genomic DNA was ... The 700 bp-PCR amplicons were cloned and cbbL clone library was constructed and analyzed by sequencing. Rarefaction curve ...

  10. Monitoring of uncultured Dunaliella sp. in an Egyptian solar saltern ...

    African Journals Online (AJOL)

    FJ-USER

    2013-08-21

    Aug 21, 2013 ... salinity, pH, light intensity and temperature. The characterization of economically important algae in solar salterns has become a key focus for many research groups all over the world (Chen and Jiang, 2009). Dunaliella species that are living in these fields, have an economic importance due to its highly ...

  11. Feeding adult of Artemia salina (Crustacea-Branchiopoda on the dinoflagellate Gyrodinium corsicum (Gymnodiniales and the Chryptophyta Rhodomonas baltica

    Directory of Open Access Journals (Sweden)

    Rauquírio André Albuquerque Marinho da Costa

    2005-07-01

    Full Text Available Experiments were carried out on feeding performance and survival rates of adult Artemia salina exposed to no axenic strains of the dinoflagellate Gyrodinium corsicum and of the Chryptophyta Rhodomonas baltica. Filtration rates on R. baltica and G. corsicum varied from 3.35 to 7.14 ml.artemia-1.h-1 and from 2.97 to 15.86 ml.artemia-1.h-1, respectively. The ingestion rates observed for A. salina did not indicate any digestive dysfunction or physiological impairment for organisms fed on G. corsicum and their functional response were similar to those observed for other organisms like copepod fed on different food concentrations. Mortality rates oscillated from 2.5% to 100% when A. salina was fed on R. baltica or G. corsicum, respectively. Highest mortality rates observed for organisms fed on G. corsicum indicated that this dinoflagellate presented a hazard effect on A. salina that was not possible to confirm if it was related to toxin production or to nutritive inadequacy of this dinoflagellate as food for organisms of this species.Experimentos foram desenvolvidos para estudar as taxas de alimentação e de sobrevivência de Artemia salina alimentada com cepas não tóxicas do dinoflagelado Gyrodinium corsicum e da Chryptophyta Rhodomonas baltica. As taxas de filtração sobre R. baltica e G. corsicum variaram entre 3,35 e 7,14 ml.artemia-1.h-1 e 2,97 e 15,86 ml.artemia-1.h-, respectivamente. As taxas de ingestão observadas para A. salina não indicaram disfunção digestiva ou prejuízo fisiológico nos organismos alimentados com G. corsicum, sendo a resposta funcional destes organismos similar a observada em copépodos alimentados com diferentes concentrações de alimento. As taxas de mortalidade de A. salina oscilaram entre 2,5 e 100% quando alimentada com R. baltica e G. corsicum, respectivamente. As maiores taxas de mortalidade observadas para os organismos alimentados com G. corsicum indicam que este dinoflagelado apresenta algum efeito

  12. Metabolomics of carotenoid accumulation in Dunaliella salina

    NARCIS (Netherlands)

    Lamers, P.P.

    2011-01-01

    Innovative production processes based on renewable resources are required to stop the exhaustion of our natural resources. Microalgae are one of the most promising feedstocks for such sustainable processes, since they can produce valuable biochemicals at high productivity using sunlight, water,

  13. Pedro Salinas: la letra y la persona

    Directory of Open Access Journals (Sweden)

    Escartín Gual, Montserrat

    2002-12-01

    Full Text Available This article is a Pedro Salinas's homage in the fifty anniversary of his death. Here, we analise his attitude in front of life and his securities through his poems, personal letters and essais. The poet criticizes the materialistic american stil of life, where he should live during his exile until his death (1936-1951. Against the hurry, the profitable things, the technology, the money..., Salinas believes in his language, slowness, friendship, contemplation of countryside, art, spiritualism, optimism, etc. Son of the Institución Libre de Enseñanza's ideas, his personal ethics looked for the biggest perfection trought the will.Este artículo es un homenaje a Pedro Salinas al cumplirse el cincuentenario de su muerte. En él, se analiza su actitud ante la vida y sus valores a través de sus poesías, cartas personales y ensayos. El poeta critica el materialismo del modelo americano en el que se vio obligado a vivir desde que se exilió hasta su muerte (1936-1951. Frente a la prisa, lo rentable, la tecnología, el dinero...; Salinas cree en su idioma, la lentitud, la amistad, la contemplación del paisaje, el arte, lo espiritual, el optimismo, etc. Hijo de las ideas de la Institución Libre de Enseñanza, su ética personal buscó la mayor perfección a través de la voluntad.

  14. Primary Screening of the Bioactivity of Brackishwater Cyanobacteria: Toxicity of Crude Extracts to Artemia salina Larvae and Paracentrotus lividus Embryos

    Directory of Open Access Journals (Sweden)

    Viviana R. Lopes

    2010-03-01

    Full Text Available Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations.

  15. Optimization of photosynthesis, growth, and biochemical composition of the microalga Rhodomonas salina

    DEFF Research Database (Denmark)

    Thuy, Minh Vu Thi; Douëtte, Claire; Rayner, Thomas Allan

    2016-01-01

    The cryptophyte Rhodomonas salina is widely used as feed for copepod cultures. However, culturing conditions to obtain high-quality algae have not yet been efficiently optimized. Therefore, we aimed to develop a cultivation protocol for R. salina to optimize its nutritional value and provide tech...

  16. Pseudomonas salina sp. nov., isolated from a salt lake.

    Science.gov (United States)

    Zhong, Zhi-Ping; Liu, Ying; Hou, Ting-Ting; Liu, Hong-Can; Zhou, Yu-Guang; Wang, Fang; Liu, Zhi-Pei

    2015-09-01

    A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85(T) were non-endospore-forming rods, 0.4-0.6 μm wide and 1.0-1.6 μm long, and motile by means of a single polar flagellum. Strain XCD-X85(T) was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0% (w/v) NaCl (optimum, 1.0-2.0%) and at 4-35 °C (optimum, 25-30 °C) and pH 6.5-10.5 (optimum, pH 8.0-8.5). Strain XCD-X85(T) contained (>10%) summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C12 : 0, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85(T) was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6(T) (99.0%) and Pseudomonas bauzanensis BZ93(T) (96.8%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562(T) was 19 ± 1%. On the basis of the data presented above, it is concluded that strain XCD-X85(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85(T) ( = CGMCC 1.12482(T) = JCM 19469(T)).

  17. Distribution and abundance of Artemia salina in the Salt Lake Basin (Central Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Alaş Ali

    2017-06-01

    Full Text Available In this study, the distribution and abundance of Artemia salina in 10 different stations of the Salt Lake basin were investigated. In addition, its relationship to pH, dissolved oxygen, temperature, electrical conductivity and water levels were analyzed. Field studies were carried out from July to August of 2010. Artemia salina was observed in five of these stations. Artemia salina was not seen in some stations that have high electrical conductivity. It is determined that, in the station named Tersakan Lake where electrical conductivity was 154 mS/cm, Artemia salina is more abundant when compared to the other stations. But as underground water pumps that are built for the irrigation of agricultural lands decrease water levels, Artemia salina’s life is under threat.

  18. Altered lipid accumulation in Nannochloropsis salina CCAP849/3 following EMS and UV induced mutagenesis

    Directory of Open Access Journals (Sweden)

    T.A. Beacham

    2015-09-01

    Full Text Available Microalgae have potential as a chemical feed stock in a range of industrial applications. Nannochloropsis salina was subject to EMS mutagenesis and the highest lipid containing cells selected using fluorescence-activated cell sorting. Assessment of growth, lipid content and fatty acid composition identified mutant strains displaying a range of altered traits including changes in the PUFA content and a total FAME increase of up to 156% that of the wild type strain. Combined with a reduction in growth this demonstrated a productivity increase of up to 76%. Following UV mutagenesis, lipid accumulation of the mutant cultures was elevated to more than 3 fold that of the wild type strain, however reduced growth rates resulted in a reduction in overall productivity. Changes observed are indicative of alterations to the regulation of the omega 6 Kennedy pathway. The importance of these variations in physiology for industrial applications such as biofuel production is discussed.

  19. Effect of environment on pigment ratios in Dunaliella spp. from the salt pans of Gujarat

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, U.D.; Goes, J.I.; Pant, A.

    The effect of varying salinity and pH of the medium on growth and pigment ratios of Dunaliella cells in culture was studied. Cell growth was found to be optimal at pH 8 and at intermediate salt concentrations of 1-2 M NaCl. Ninety per cent acetone...

  20. Beta-Carotene production enhancement by UV-A radiation in Dunaliella bardawil cultivated in laboratory reactors

    International Nuclear Information System (INIS)

    Mogedas, B.; Casal, C.; Forjan, E.; Vilchez, C.

    2009-01-01

    beta-Carotene is an antioxidant molecule of commercial value that can be naturally produced by certain microalgae that mostly belong to the genus Dunaliella. So far, nitrogen starvation has been the most efficient condition for enhancing beta-carotene accumulation in Dunaliella. However, while nitrogen starvation promotes beta-carotene accumulation, the cells become non-viable; consequently under such conditions, continuous beta-carotene production is limited to less than 1 week. In this study, the use of UV-A radiation as a tool to enhance long-term beta-carotene production in Dunaliella bardawil cultures was investigated. The effect of UV-A radiation (320-400 nm) added to photosynthetically active radiation (PAR, 400-700 nm) on growth and carotenoid accumulation of D. bardawil in a laboratory air-fluidized bed photobioreactor was studied. The results were compared with those from D. bardawil control cultures incubated with PAR only. The addition of 8.7 W/square m UV-A radiation to 250 W/square m PAR stimulated long-term growth of D. bardawil. Throughout the exponential growth period the UV-A irradiated cultures showed enhanced carotenoid accumulation, mostly as beta-carotene. After 24 days, the concentration of beta-carotene in UV-A irradiated cultures was approximately two times that of control cultures. Analysis revealed that UV-A clearly induced major accumulation of all-trans beta-carotene. In N-starved culture media, beta-carotene biosynthesis in UV-A irradiated cultures was stimulated. We conclude that the addition of UV-A to PAR enhances carotenoid production processes, specifically all-trans beta-carotene, in D. bardawil cells without negative effects on cell growth

  1. Biochemical Modulation of Lipid Pathway in Microalgae Dunaliella sp. for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad Talebi

    2015-01-01

    Full Text Available Exploitation of renewable sources of energy such as algal biodiesel could turn energy supplies problem around. Studies on a locally isolated strain of Dunaliella sp. showed that the mean lipid content in cultures enriched by 200 mg L−1 myoinositol was raised by around 33% (1.5 times higher than the control. Similarly, higher lipid productivity values were achieved in cultures treated by 100 and 200 mg L−1 myoinositol. Fluorometry analyses (microplate fluorescence and flow cytometry revealed increased oil accumulation in the Nile red-stained algal samples. Moreover, it was predicted that biodiesel produced from myoinositol-treated cells possessed improved oxidative stability, cetane number, and cloud point values. From the genomic point of view, real-time analyses revealed that myoinositol negatively influenced transcript abundance of AccD gene (one of the key genes involved in lipid production pathway due to feedback inhibition and that its positive effect must have been exerted through other genes. The findings of the current research are not to interprete that myoinositol supplementation could answer all the challenges faced in microalgal biodiesel production but instead to show that “there is a there there” for biochemical modulation strategies, which we achieved, increased algal oil quantity and enhanced resultant biodiesel quality.

  2. Biochemical Modulation of Lipid Pathway in Microalgae Dunaliella sp. for Biodiesel Production

    Science.gov (United States)

    Talebi, Ahmad Farhad; Tohidfar, Masoud; Mousavi Derazmahalleh, Seyedeh Mahsa; Sulaiman, Alawi; Baharuddin, Azhari Samsu; Tabatabaei, Meisam

    2015-01-01

    Exploitation of renewable sources of energy such as algal biodiesel could turn energy supplies problem around. Studies on a locally isolated strain of Dunaliella sp. showed that the mean lipid content in cultures enriched by 200 mg L−1 myoinositol was raised by around 33% (1.5 times higher than the control). Similarly, higher lipid productivity values were achieved in cultures treated by 100 and 200 mg L−1 myoinositol. Fluorometry analyses (microplate fluorescence and flow cytometry) revealed increased oil accumulation in the Nile red-stained algal samples. Moreover, it was predicted that biodiesel produced from myoinositol-treated cells possessed improved oxidative stability, cetane number, and cloud point values. From the genomic point of view, real-time analyses revealed that myoinositol negatively influenced transcript abundance of AccD gene (one of the key genes involved in lipid production pathway) due to feedback inhibition and that its positive effect must have been exerted through other genes. The findings of the current research are not to interprete that myoinositol supplementation could answer all the challenges faced in microalgal biodiesel production but instead to show that “there is a there there” for biochemical modulation strategies, which we achieved, increased algal oil quantity and enhanced resultant biodiesel quality. PMID:26146623

  3. Technological processes for obtaining ß-carotene and glycerol from Dunaliella sp. at 'Las Cumaraguas' Saltworks

    International Nuclear Information System (INIS)

    Acacio-ChirinoI, Noel José; Zumalacárregui-de Cárdenas, Lourdes Margarita

    2017-01-01

    Technological processes were developed for ß-carotene and glycerol extraction from Dunaliella sp. at 'Las Cumaraguas' Saltworks. Dunaliella sp. microalgae was characterize. It was established the technological flow of the process from laboratory data; energy balances and necessary energetic calculations were done, in order to select and size the required equipment for a pilot plant scale to produce one ton of ß-carotene. Two possibilities were evaluated: extraction with organic solvents and extraction with supercritical fluids. The procedure showed that ß-carotene and glycerol extractions are possible by means of the presented technological diagram, with 15,4 % of biomass ß-carotene yield and 5 % of biomass glycerol yield, for a conventional extraction and a yield of 70 % for ß-carotene from pigments and 5 % of biomass glycerol yield, for extraction with supercritical fluid. (author)

  4. The effect of AgNO3 on the bioenergetic processes and the ultrastructure of Chlorella and Dunaliella cells exposed to different saline conditions

    International Nuclear Information System (INIS)

    Loseva, N.L.; Alyabyev, A.Ju.; Gordon, L.Kh.; Andreyeva, I.N.; Kolesnikov, O.P.; Ponomareva, A.A.; Kemp, R.B.

    2007-01-01

    The effect of AgNO 3 , an inhibitor of the H + pump in the plasma membrane, on the bioenergetic processes and on the ultrastructure of the microalgae Chlorella vulgaris (salt sensitive) and Dunaliella maritima (salt resistant) was examined under varying salt concentrations. Differences between them were observed in changes of the cellular energy metabolism depending on their salt sensitivity and the inhibition of the H + pump activity. A decrease was observed in the rates of heat production (about 45%), O 2 uptake (greater than 40-50% of the control) and particularly photosynthesis (more than 80%) in Chlorella cells under the simultaneous action of NaCl and AgNO 3 . Dunaliella cells showed small to moderate rate increases for heat production (less than 7%), O 2 uptake (10-15%) and O 2 evolution (40%) in higher salt concentrations and under the action of AgNO 3 . The production of active oxygen species was studied as an early unspecific response of microalgal cells to possible unfavorable conditions, including salt stress. The amount of superoxide formed by the Dunaliella cells was higher than that by the Chlorella cells. However, Ag + ions increased the generation rate of superoxide radicals considerably in both Chlorella and Dunaliella cells. The electron microscopy showed that changes of the algal ultrastructure of cells exposed to the action of Ag + ions were connected with the observed physiological changes and to a large extent with the alteration of the bioenergetic processes in them

  5. Determination of biological and physicochemical parameters of Artemia franciscana strains in hypersaline environments for aquaculture in the Colombian Caribbean.

    Science.gov (United States)

    Camargo, William N; Durán, Gabriel C; Rada, Orlando C; Hernández, Licet C; Linero, Juan-Carlos G; Muelle, Igor M; Sorgeloos, Patrick

    2005-10-26

    Artemia (Crustacea, Anostraca), also known as brine shrimp, are typical inhabitants of extreme environments. These hypersaline environments vary considerably in their physicochemical composition, and even their climatic conditions and elevation. Several thalassohaline (marine) environments along the Colombian Caribbean coast were surveyed in order to contribute to the knowledge of brine shrimp biotopes in South America by determining some vital biological and physicochemical parameters for Artemia survival. Additionally, cyst quality tests, biometrical and essential fatty acids analysis were performed to evaluate the economic viability of some of these strains for the aquaculture industry. In addition to the three locations (Galerazamba, Manaure, and Pozos Colorados) reported in the literature three decades ago in the Colombian Caribbean, six new locations were registered (Salina Cero, Kangaru, Tayrona, Bahía Hondita, Warrego and Pusheo). All habitats sampled showed that chloride was the prevailing anion, as expected, because of their thalassohaline origin. There were significant differences in cyst diameter grouping strains in the following manner according to this parameter: 1) San Francisco Bay (SFB-Control, USA), 2) Galerazamba and Tayrona, 3) Kangarú, 4) Manaure, and 5) Salina Cero and Pozos Colorados. Chorion thickness values were smaller in Tayrona, followed by Salina Cero, Galerazamba, Manaure, SFB, Kangarú and Pozos Colorados. There were significant differences in naupliar size, grouping strains as follows (smallest to largest): 1) Galerazamba, 2) Manaure, 3) SFB, Kangarú, and Salina Cero, 4) Pozos Colorados, and 5) Tayrona. Overall, cyst quality analysis conducted on samples from Manaure, Galerazamba, and Salina Cero revealed that all sites exhibited a relatively high number of cysts.g-1. Essential fatty acids (EFA) analysis performed on nauplii from cyst samples from Manaure, Galerazamba, Salina Cero and Tayrona revealed that cysts from all sites

  6. The alternative oxidase mediated respiration contributes to growth, resistance to hyperosmotic media and accumulation of secondary metabolites in three species

    OpenAIRE

    Sitaramam, V.; Pachapurkar, Shilpa; Gokhale, Trupti

    2008-01-01

    Plant respiration, similar to respiration in animal mitochondria, exhibits both osmosensitive and insensitive components with the clear distinction that the insensitive respiration in plants is quantitatively better described as ‘less’ sensitive rather than ‘insensitive’. Salicylic hydroxamic acid (SHAM)-sensitive respiration was compared with the respiration sensitive to other inhibitors in rice, yeast and Dunaliella salina. The influence of SHAM was largely in the osmotically less sensitive...

  7. Toxicities of diuron and irgarol on the hatchability and early stage development of Artemia salina

    OpenAIRE

    ALYÜRÜK, Hakan; ÇAVAŞ, Levent

    2013-01-01

    Booster biocides are widely used in antifouling paints as bioactive agents against fouling organisms. In previously published reports, acute toxicity tests on Artemia salina (Linnaeus, 1758) were only focused on a part of the life cycle of the organism. The aim of this study was to investigate the toxicities of diuron and irgarol on the hatching stage of A. salina. According to the results, diuron significantly decreased the hatching percentage of A. salina cysts and prevented the hatching of...

  8. Contribution of Co2+ in increasing chlorophyll a concentration of Nannochloropsis salina in controlled Conwy medium

    Science.gov (United States)

    Hala, Y.; Taba, P.; Suryati, E.; Kasih, P.; Firman, N. F.

    2018-03-01

    A research in determining the contribution of Co2+ on the increase of chlorophyll a concentration of Nannochloropsis salina has been caried out. The cultivation of N. salina was conducted in the Conwy medium with a salinity of 5%o and 25%o and various Co2+ concentration (2, 4, and 8 ppm). In this research, Co2+ was exposed early in the cultivation of N. salina. The growth of N. salina was observed daily by counting the number of populations using a haemocytometer while the chlorophyll a concentration was determined by a Uv-Vis spectrophotometer. The results showed that the growth of N. salina in the control was higher than that in the medium containing Co2+. The optimum growth time was achieved on 15th days (5%) and 8th days (25%). In the cultivation medium with a salinity of 5%, Co2+ with a concentration of 2 ppm increased the chlorophyll a level while Co2+ with concentrations of 4 and 8 ppm decreased it. In the medium of cultivation with a salinity of 25%, the increase in chlorophyll a level was observed at Co2+ concentrations of 2 and 4 ppm whereas the decrease in chlorophyl a level was given at a concentration of 8 ppm. It can be concluded that at low concentrations, Co2+ increased the concentration of chlorophyll a in N. salina.

  9. The effect of AgNO{sub 3} on the bioenergetic processes and the ultrastructure of Chlorella and Dunaliella cells exposed to different saline conditions

    Energy Technology Data Exchange (ETDEWEB)

    Loseva, N.L. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation)]. E-mail: loseva@mail.knc.ru; Alyabyev, A.Ju. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation); Gordon, L.Kh. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation); Andreyeva, I.N. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation); Kolesnikov, O.P. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation); Ponomareva, A.A. [Institute of Biochemistry and Biophysics, Russian Academy of Sciences, P.O. Box 30, Kazan 420111 (Russian Federation); Kemp, R.B. [Institute of Biological Sciences, Edward Llwyd Building, Penglais, University of Wales, Aberystwyth SY23 3DA (United Kingdom)

    2007-06-25

    The effect of AgNO{sub 3}, an inhibitor of the H{sup +} pump in the plasma membrane, on the bioenergetic processes and on the ultrastructure of the microalgae Chlorella vulgaris (salt sensitive) and Dunaliella maritima (salt resistant) was examined under varying salt concentrations. Differences between them were observed in changes of the cellular energy metabolism depending on their salt sensitivity and the inhibition of the H{sup +} pump activity. A decrease was observed in the rates of heat production (about 45%), O{sub 2} uptake (greater than 40-50% of the control) and particularly photosynthesis (more than 80%) in Chlorella cells under the simultaneous action of NaCl and AgNO{sub 3}. Dunaliella cells showed small to moderate rate increases for heat production (less than 7%), O{sub 2} uptake (10-15%) and O{sub 2} evolution (40%) in higher salt concentrations and under the action of AgNO{sub 3}. The production of active oxygen species was studied as an early unspecific response of microalgal cells to possible unfavorable conditions, including salt stress. The amount of superoxide formed by the Dunaliella cells was higher than that by the Chlorella cells. However, Ag{sup +} ions increased the generation rate of superoxide radicals considerably in both Chlorella and Dunaliella cells. The electron microscopy showed that changes of the algal ultrastructure of cells exposed to the action of Ag{sup +} ions were connected with the observed physiological changes and to a large extent with the alteration of the bioenergetic processes in them.

  10. Salinas de interior en el territorio de la Región de Murcia

    Directory of Open Access Journals (Sweden)

    S. Gil Guirado

    2010-01-01

    Full Text Available La sal es un elemento necesario en la actividad de los grupos humanos. Para su captación y recolección se ha ordenado el territorio, con unos paisajes propios: las salinas. Podemos distinguir dos tipos: las salinas costeras y las salinas de interior. En estas últimas, su localización y explotación está ligada a la presencia de algún material salino que atraviesa el agua. En ellas se pueden distinguir tres áreas, la de captación del agua (generalmente pozos horizontales del tipo minado o galería; la de almacenaje (con balsas y recocederos dónde acumular y calentar; y finalmente la de cristalización (con parcelas más o menos aterrazadas conocidas como eras. A través del estudio combinado del trabajo de campo y la documentación de archivos, hemos podido localizar una veintena de salinas en el interior de la Región de Murcia; huella de una actividad económica y de una cultura del agua entre la variedad de paisajes surestinos.

  11. Growth effects on mixed culture of Dunaliella salina and ...

    African Journals Online (AJOL)

    AJL

    2011-10-10

    Oct 10, 2011 ... compounds of nutritional supplements or food additives. (Wikfors and Ohno ... mixed cultures of marine microalgae and most of the work has been ..... This work was supported by the National Natural Science. Foundation of ...

  12. B-Carotene-a long road to commercial implementation

    CSIR Research Space (South Africa)

    Gardiner, NS

    2006-09-01

    Full Text Available ) • Animal feed supplements • Food supplements – colorant, Vitamin A supplement • OTC pharmaceuticals (health supplements) – anti-oxidant, Vitamin A supplement © CSIR 2006 www.csir.co.zaSlide 4 Production • Chemical synthesis... • BASF, DSM (formerly Roche) • Algal production (Dunaliella salina) • Betatene (Cognis), Koor Foods, NCSA • Extraction from natural sources (carrots, palm oil) • DSM (formerly Roche), Hanson and Darius • Fungal production (Blakeslea trispora) • DSM...

  13. Larvicidal activity of some marine macrophytes against Artemia salina

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    and Microdictyon pseudohapteron, seagrasses (Halophila ovalis and Syringodium isoetifolium and lichens (Umbilicaria arpina) were tested for larvicidal activity using Artemia salina nauplii. The LC50 values for the PE-fraction of M. pseudohapteron and A. muscoides...

  14. Evaluation of the photodynamic activity of Xanthene Dyes on Artemia salina described by chemometric approaches

    Directory of Open Access Journals (Sweden)

    Diogo S. Pellosi

    2013-10-01

    Full Text Available The development of drugs for photodynamic therapy (PDT is an important area of research due to their growing use in medical applications. Therefore, it is important to develop new bioassay methods for PDT photosensitizers that are inexpensive, easy to handle and highly sensitive to environmental conditions. Xanthene dyes (fluorescein, rose bengal B, erythrosine B and eosin Y with LED light sources were investigated using Artemia salina as a bioindicator of photodynamic activity. In this study, three factors were investigated: (i photosensitizers concentration, (ii the LED irradiation time and (iii the waiting time between the addition of the photosensitizers and the beginning of the irradiation. To analyze the photo-killing of A. salina, it was employed a 23 full factorial design. The death of A. salina was related to dye structure and the interaction between the irradiation time and the photosensitizers concentration. About 60% of crustaceans death was obtained using rose bengal B, which presentes the highest quantum yield of singlet oxygen due to the number of iodide substituents in the xanthenes ring. The proposed bioassay using A. salina, xanthene dyes and LED irradiation was found suitable for quantitative PDT drug evaluation.

  15. Studies on experimental culture of a marine ciliate Fabrea salina

    Digital Repository Service at National Institute of Oceanography (India)

    Rattan, R.; Ansari, Z.A.; Chatterji, A.

    Studies were conducted on the culture of a marine ciliate, Fabrea salina in the laboratory condition. Three types of inert feed; commercial yeast, fermented wheat bran and fermented rise bran were tested to study their suitability as artificial feed...

  16. Phototoxicity activity of Psoralea drupacea L. using Atremia salina bioassay system

    Directory of Open Access Journals (Sweden)

    Mohammad Ramezani

    2011-07-01

    Conclusion: The result showed that P. drupacea methanolic extract and chloroform fraction have phototoxicity in A. salina bioassay system and their toxic effect is related to phototoxic constituents such as psoralen.

  17. Em torno da luz cristalina: clara voz de Pedro Salinas

    Directory of Open Access Journals (Sweden)

    Cristiano Moreira

    2015-06-01

    Full Text Available http://dx.doi.org/10.5007/2176-8552.2016n20p147 O texto que segue pretende ler a poesia de Pedro Salinas e Jorge Guillén diante de uma perspectiva que faz da voz uma iluminação e uma resistência diante do tempo histórico e da predominância de uma leitura simples das imagens. Assim, alguns poemas escolhidos permitem uma leitura contemporânea a respeito da voz, seguindo o conceito de Stimmung recuperado por Giorgio Agamben e as lições de poesia de Paul Valéry, e formam aspectos imprescindíveis para ler a poesia destes poetas. Ao manter em sua produção uma conversação com seus predecessores, Pedro Salinas joga com o logos e faz da phoné matéria prima para sua obra.

  18. Effects of light intensity and nitrogen starvation on glycerolipid, glycerophospholipid, and carotenoid composition in Dunaliella tertiolecta culture.

    Directory of Open Access Journals (Sweden)

    So-Hyun Kim

    Full Text Available Time-course variation of lipid and carotenoid production under high light (300 μE/m²s and nitrogen starvation conditions was determined in a Dunaliella tertiolecta strain. Nanoelectrospray (nanoESI chip based direct infusion was used for lipid analysis and ultra-performance liquid chromatography (UPLC coupled with a photodiode array (PDA or atmospheric chemical ionization mass spectrometry (APCI-MS was used for carotenoid analysis. A total of 29 lipids and 7 carotenoids were detected. Alterations to diacylglyceryltrimethylhomoserine (DGTS and digalactosyldiacylglycerol (DGDG species were significant observations under stress conditions. Their role in relation to the regulation of photosynthesis under stress condition is discussed in this study. The total carotenoid content was decreased under stress conditions, while ã-carotene was increased under nitrate-deficient cultivation. The highest productivity of carotenoid was attained under high light and nitrate sufficiency (HLNS condition, which result from the highest level of biomass under HLNS. When stress was induced at stationary phase, the substantial changes to the lipid composition occurred, and the higher carotenoid content and productivity were exhibited. This is the first report to investigate the variation of lipids, including glycerolipid, glycerophospholipid, and carotenoid in D. tertiolecta in response to stress conditions using lipidomics tools.

  19. Prospecção fitoquímica de Sonchus oleraceus e sua toxicidade sobre o microcrustáceo Artemia salina Phytochemical prospecting of Sonchus oleraceus and its toxicity to Artemia salina

    Directory of Open Access Journals (Sweden)

    J.M. Lima

    2009-03-01

    Full Text Available A espécie vegetal Sonchus oleraceus é uma planta daninha presente em diversas culturas no Brasil e de utilização na medicina popular. Neste trabalho, realizou-se a prospecção fitoquímica dessa espécie com extratos em etanol, água e diclorometano, bem como testes de toxicidade sobre o microcrustáceo Artemia salina. O extrato aquoso apresentou em sua composição açúcares redutores, compostos fenólicos, taninos, flavonóides e cumarinas. No extrato etanólico, observaram-se os mesmos compostos qualificados no extrato aquoso, com exceção de cumarinas. Em diclorometano, verificou se a presença de saponinas, derivados triterpênicos e esteróides. No teste de toxicidade sobre Artemia salina, os dados convergiram para frações de extrato aquoso de 5.117,2 ppm, indicando ser um extrato de baixa toxicidade.Sonchus oleraceus is a common weed in Brazil, also used as a medicinal plant. Phytochemical prospecting of this species was carried out in this work using extracts obtained in ethanol, water and dichloromethane. A toxicity study of the aqueous extract was also conducted, using the micro crustaceous Artemia salina. The aqueous extract presented sugar reducers, phenolic compounds, tannins, flavonoids and coumarins in its composition. The compounds found in the aqueous extract were also detected in the ethanol extract, except for the coumarins. Saponin, triterpenes and steroids were identified in the dichloromethane extract. The toxicity test on Artemia salina pointed to aqueous extract fractions of 5,117.2 ppm, indicative of low toxicity.

  20. Heterologous overexpression of sfCherry fluorescent protein in Nannochloropsis salina

    Directory of Open Access Journals (Sweden)

    Nam Kyu Kang

    2015-12-01

    Full Text Available Oleaginous microalgae of the Nannochloropsis genus are considered excellent candidates for biofuels and value-added products owing to their high biomass productivity and lipid content. Here, we report the first overexpression and detection of a heterologous sfCherry fluorescent protein in Nannochloropsis salina in order to develop a transformation toolbox for future genetic improvements. Particle bombardment was employed for transformation, and expression of Shble under the control of TUB and UEP promoters, cloned from N. salina, was used to confer resistance to Zeocin antibiotics, resulting in 5.9 and 4.7 transformants per 108 cells, respectively. Stable integration of the markers into the genome was confirmed using a restriction enzyme site-directed amplification (RESDA PCR. The expression of sfCherry fluorescent protein was confirmed by Western blot analysis and confocal microscopy. These results suggest new possibilities of efficient genetic engineering of Nannochloropsis for the production of biofuels and other biochemicals.

  1. Effect of enriched Brachionus plicatilis and Artemia salina nauplii by ...

    African Journals Online (AJOL)

    The growth, developmental stages and survival rates of Sparus aurata larvae fed with Brachionus plicatilis and Artemia salina nauplii enriched by microalga Tetraselmis chuii were studied. Two experiments were carried out; the first concerning with culturing the microalga (T. chuii) in four different media, then using these ...

  2. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

    Directory of Open Access Journals (Sweden)

    Hamed Safafar

    2016-07-01

    Full Text Available Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA. Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids, tocopherols and carotenoids for potential use in aquaculture feed industry.

  3. The laboratory environmental algae pond simulator (LEAPS) photobioreactor: Validation using outdoor pond cultures of Chlorella sorokiniana and Nannochloropsis salina

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, M.; Williams, P.; Edmundson, S.; Chen, P.; Kruk, R.; Cullinan, V.; Crowe, B.; Lundquist, T.

    2017-09-01

    A bench-scale photobioreactor system, termed Laboratory Environmental Algae Pond Simulator (LEAPS), was designed and constructed to simulate outdoor pond cultivation for a wide range of geographical locations and seasons. The LEAPS consists of six well-mixed glass column photobioreactors sparged with CO2-enriched air to maintain a set-point pH, illuminated from above by a programmable multicolor LED lighting (0 to 2,500 µmol/m2-sec), and submerged in a temperature controlled water-bath (-2 °C to >60 °C). Measured incident light intensities and water temperatures deviated from the respective light and temperature set-points on average only 2.3% and 0.9%, demonstrating accurate simulation of light and temperature conditions measured in outdoor ponds. In order to determine whether microalgae strains cultured in the LEAPS exhibit the same linear phase biomass productivity as in outdoor ponds, Chlorella sorokiniana and Nannochloropsis salina were cultured in the LEAPS bioreactors using light and temperature scripts measured previously in the respective outdoor pond studies. For Chlorella sorokiniana, the summer season biomass productivity in the LEAPS was 6.6% and 11.3% lower than in the respective outdoor ponds in Rimrock, Arizona, and Delhi, California; however, these differences were not statistically significant. For Nannochloropsis salina, the winter season biomass productivity in the LEAPS was statistically significantly higher (15.2%) during the 27 day experimental period than in the respective outdoor ponds in Tucson, Arizona. However, when considering only the first 14 days, the LEAPS biomass productivity was only 9.2% higher than in the outdoor ponds, a difference shown to be not statistically significant. Potential reasons for the positive or negative divergence in LEAPS performance, relative to outdoor ponds, are discussed. To demonstrate the utility of the LEAPS in predicting productivity, two other strains – Scenedesmus obliquus and Stichococcus minor

  4. Smart SfM: Salinas Archaeological Museum

    Science.gov (United States)

    Inzerillo, L.

    2017-08-01

    In these last years, there has been an increasing use of the Structure from Motion (SfM) techniques applied to Cultural Heritage. The accessibility of SfM software can be especially advantageous to users in non-technical fields or to those with limited resources. Thanks to SfM using, everyone can make with a digital camera a 3D model applied to an object of both Cultural Heritage, and physically Environment, and work arts, etc. One very interesting and useful application can be envisioned into museum collection digitalization. In the last years, a social experiment has been conducted involving young generation to live a social museum using their own camera to take pictures and videos. Students of university of Catania and Palermo were involved into a national event #digitalinvasion (2015-2016 editions) offering their personal contribution: they realized 3D models of the museums collection through the SfM techniques. In particular at the National Archaeological Museum Salinas in Palermo, it has been conducted an organized survey to recognize the most important part of the archaeological collection. It was a success: in both #digitalinvasion National Event 2015 and 2016 the young students of Engineering classes carried out, with Photoscan Agisoft, more than one hundred 3D models some of which realized by phone camera and some other by reflex camera and some other with compact camera too. The director of the museum has been very impressed from these results and now we are going to collaborate at a National project to use the young generation crowdsourcing to realize a semi-automated monitoring system at Salinas Archaeological Museum.

  5. SMART SfM: SALINAS ARCHAEOLOGICAL MUSEUM

    Directory of Open Access Journals (Sweden)

    L. Inzerillo

    2017-08-01

    Full Text Available In these last years, there has been an increasing use of the Structure from Motion (SfM techniques applied to Cultural Heritage. The accessibility of SfM software can be especially advantageous to users in non-technical fields or to those with limited resources. Thanks to SfM using, everyone can make with a digital camera a 3D model applied to an object of both Cultural Heritage, and physically Environment, and work arts, etc. One very interesting and useful application can be envisioned into museum collection digitalization. In the last years, a social experiment has been conducted involving young generation to live a social museum using their own camera to take pictures and videos. Students of university of Catania and Palermo were involved into a national event #digitalinvasion (2015-2016 editions offering their personal contribution: they realized 3D models of the museums collection through the SfM techniques. In particular at the National Archaeological Museum Salinas in Palermo, it has been conducted an organized survey to recognize the most important part of the archaeological collection. It was a success: in both #digitalinvasion National Event 2015 and 2016 the young students of Engineering classes carried out, with Photoscan Agisoft, more than one hundred 3D models some of which realized by phone camera and some other by reflex camera and some other with compact camera too. The director of the museum has been very impressed from these results and now we are going to collaborate at a National project to use the young generation crowdsourcing to realize a semi-automated monitoring system at Salinas Archaeological Museum.

  6. Growth of mono- and mixed cultures of Nannochloropsis salina and Phaeodactylum tricornutum on struvite as a nutrient source

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Siccardi, Anthony J. [Texas AgriLife Research Mariculture Lab., Corpus Christi, TX (United States); Huysman, Nathan D. [Texas AgriLife Research Mariculture Lab., Corpus Christi, TX (United States); Wyatt, Nicholas B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hewson, John C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lane, Todd W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-09-26

    In this paper, the suitability of crude and purified struvite (MgNH4PO4), a major precipitate in wastewater streams, was investigated for renewable replacement of conventional nitrogen and phosphate resources for cultivation of microalgae. Bovine effluent wastewater stone, the source of crude struvite, was characterized for soluble N/P, trace metals, and biochemical components and compared to the purified mineral. Cultivation trials using struvite as a major nutrient source were conducted using two microalgae production strains, Nannochloropsis salina and Phaeodactylum tricornutum, in both lab and outdoor pilot-scale raceways in a variety of seasonal conditions. Both crude and purified struvite-based media were found to result in biomass productivities at least as high as established media formulations (maximum outdoor co-culture yield ~20 ± 4 g AFDW/m2/day). Finally, analysis of nutrient uptake by the alga suggest that struvite provides increased nutrient utilization efficiency, and that crude struvite satisfies the trace metals requirement and results in increased pigment productivity for both microalgae strains.

  7. Nesting ecology of Pied Avocet Recurvirostra avosetta in Sfax salina ...

    African Journals Online (AJOL)

    In this paper we use the results of a one-year monitoring of nests in Sfax salina to provide information on its nesting parameters, in particular nesting phenology, colony size and hatching success. Our results show that Pied Avocets formed dense colonies at the beginning of the nesting season, but colony size decreased as ...

  8. PHYTOCHEMICAL STUDY, MICROBIOLOGICAL AND CYTOTOXICITYTY ACTIVITY IN Artemia salina LEACH, AERIAL PARTS OF Petiveria alliacea L. PHYTOLACCACEAE.

    Directory of Open Access Journals (Sweden)

    Darllen Suzanny Barbosa de Oliveira

    2013-12-01

    Full Text Available This study aimed to phytochemical study of the aerial parts of Petiveria alliacea L. (young branches and leaves, cytotoxicity evaluation (LC50 of leaves in relation to Artemia salina L. and antimicrobial activity, which were used strains of gram-positive bacterium: Staphylococcus aureus and gram-negative: Klebsiella pneumoniae and Escherichia coli, these submitted to the methanol crude extract (MCE of leaves, at the following concentrations: 25.50 and 100mg/mL. It was possible to identify in the young branches of P. alliacea L. the presence of organic acids, phenols and tannins in the alkaloids leaves, steroids and triterpenoids, saponins, phenols and tannins, where the activities of these metabolites match with some information alleged by the population. The leaves’ Methanol Crude Extract showed LC50=1709.77μg/mL, being nontoxic at the tested concentrations, whereas for plant extract in relation to A.salina are considered nontoxic when LC50>1000μg/mL. The antimicrobial activity of the Methanol Crude Extract of the leaves showed inhibition only for the bacteria Escherichia coli at 100mg/mL concentration, and this activity may be related to the presence of phenols and tannins in the extract. The obtained results turn the species promising in search of secondary metabolites, but there is the need of further studies to identify its main active ingredients. Palavras-chave: Mucuracaa, Phytochemical Screening, Class of Compounds. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n3p76-82

  9. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

    DEFF Research Database (Denmark)

    Safafar, Hamed; Hass, Michael Z.; Møller, Per

    2016-01-01

    salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality...... of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scaleusing a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large...... after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark.The resulting biomass is a rich source of EPA and also a good...

  10. Effects of tributyltin on the chlorophyll contents of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp

    OpenAIRE

    Rumampuk, Natalie D. C.; Rumengan, Inneke F. M.; Ohji, Madoka; Arai, Takaomi; Miyazaki, Nobuyuki

    2004-01-01

    Three species of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp., the important phyto-plankton in many hatcheries, were used in an acute toxicity test of TBT with emphasis on the chlorophyll a and b contents. After a very short exposure time of three concentrations of TBT, 0.1, 0.5 and 1μgl^, the three species of algae showed different responses. The chlorophyll a and b contents of T. tetrathele in all treatments were higher than those in controls, even be ...

  11. Assessment of the Antimicrobial Activity of Algae Extracts on Bacteria Responsible of External Otitis

    Directory of Open Access Journals (Sweden)

    Gianluca Pane

    2015-10-01

    Full Text Available External otitis is a diffuse inflammation around the external auditory canal and auricle, which is often occurred by microbial infection. This disease is generally treated using antibiotics, but the frequent occurrence of antibiotic resistance requires the development of new antibiotic agents. In this context, unexplored bioactive natural candidates could be a chance for the production of targeted drugs provided with antimicrobial activity. In this paper, microbial pathogens were isolated from patients with external otitis using ear swabs for over one year, and the antimicrobial activity of the two methanol extracts from selected marine (Dunaliella salina and freshwater (Pseudokirchneriella subcapitata microalgae was tested on the isolated pathogens. Totally, 114 bacterial and 11 fungal strains were isolated, of which Staphylococcus spp. (28.8% and Pseudomonas aeruginosa (P. aeruginosa (24.8% were the major pathogens. Only three Staphylococcus aureus (S. aureus strains and 11 coagulase-negative Staphylococci showed resistance to methicillin. The two algal extracts showed interesting antimicrobial properties, which mostly inhibited the growth of isolated S. aureus, P. aeruginosa, Escherichia coli, and Klebsiella spp. with MICs range of 1.4 × 109 to 2.2 × 1010 cells/mL. These results suggest that the two algae have potential as resources for the development of antimicrobial agents.

  12. Integrated assessment of the impacts of agricultural drainwater in the Salinas River (California, USA)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S.; Hunt, J.W.; Phillips, B.M.; Nicely, P.A.; Vlaming, V. de; Connor, V.; Richard, N.; Tjeerdema, R.S

    2003-08-01

    Invertebrate mortality was correlated with levels of water and sediment contaminatioin in the Salinas River. - The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California. Large areas of this watershed are cultivated year-round in row crops and previous laboratory studies have demonstrated that acute toxicity of agricultural drainwater to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. In the current study, we used a combination of ecotoxicologic tools to investigate incidence of chemical contamination and toxicity in waters and sediments in the river downstream of a previously uncharacterized agricultural drainage creek system. Water column toxicity was investigated using a cladoceran C. dubia while sediment toxicity was investigated using an amphipod Hyalella azteca. Ecological impacts of drainwater were investigated using bioassessments of macroinvertebrate community structure. The results indicated that Salinas River water downstream of the agricultural drain is acutely toxic to Ceriodaphnia, and toxicity to this species was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to H. azteca, which is a resident genus. Macroinvertebrate community structure was moderately impacted downstream of the agricultural drain input. While the lowest macroinvertebrate abundances were measured at the station demonstrating the greatest water column and sediment toxicity and the highest concentrations of pesticides, macroinvertebrate metrics were more significantly correlated with bank vegetation cover than any other variable. Results of this study suggest that pesticide pollution is the likely cause of laboratory-measured toxicity in the Salinas River samples and that this factor may interact with other factors to impact the

  13. Integrated assessment of the impacts of agricultural drainwater in the Salinas River (California, USA)

    International Nuclear Information System (INIS)

    Anderson, B.S.; Hunt, J.W.; Phillips, B.M.; Nicely, P.A.; Vlaming, V. de; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2003-01-01

    Invertebrate mortality was correlated with levels of water and sediment contaminatioin in the Salinas River. - The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California. Large areas of this watershed are cultivated year-round in row crops and previous laboratory studies have demonstrated that acute toxicity of agricultural drainwater to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. In the current study, we used a combination of ecotoxicologic tools to investigate incidence of chemical contamination and toxicity in waters and sediments in the river downstream of a previously uncharacterized agricultural drainage creek system. Water column toxicity was investigated using a cladoceran C. dubia while sediment toxicity was investigated using an amphipod Hyalella azteca. Ecological impacts of drainwater were investigated using bioassessments of macroinvertebrate community structure. The results indicated that Salinas River water downstream of the agricultural drain is acutely toxic to Ceriodaphnia, and toxicity to this species was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to H. azteca, which is a resident genus. Macroinvertebrate community structure was moderately impacted downstream of the agricultural drain input. While the lowest macroinvertebrate abundances were measured at the station demonstrating the greatest water column and sediment toxicity and the highest concentrations of pesticides, macroinvertebrate metrics were more significantly correlated with bank vegetation cover than any other variable. Results of this study suggest that pesticide pollution is the likely cause of laboratory-measured toxicity in the Salinas River samples and that this factor may interact with other factors to impact the

  14. Okadaic acid inhibits cell growth and photosynthetic electron transport in the alga Dunaliella tertiolecta

    Energy Technology Data Exchange (ETDEWEB)

    Perreault, Francois; Matias, Marcelo Seleme; Oukarroum, Abdallah [Department of Chemistry, Universite du Quebec a Montreal, 2101, Rue Jeanne Mance, Montreal, QC, Canada H2X 2J6 (Canada); Matias, William Gerson [Department of Chemistry, Universite du Quebec a Montreal, 2101, Rue Jeanne Mance, Montreal, QC, Canada H2X 2J6 (Canada); Laboratorio de Toxicologia Ambiental, LABTOX, Depto. de Engenharia Sanitaria e Ambiental, Universidade Federal de Santa Catarina, Campus Universitario, CEP: 88040-970, Florianopolis, SC (Brazil); Popovic, Radovan, E-mail: popovic.radovan@uqam.ca [Department of Chemistry, Universite du Quebec a Montreal, 2101, Rue Jeanne Mance, Montreal, QC, Canada H2X 2J6 (Canada)

    2012-01-01

    Okadaic acid (OA), which is produced by several dinoflagellate species, is a phycotoxin known to induce a decrease of biomass production in phytoplankton. However, the mechanisms of OA cytotoxicity are still unknown in microalgae. In this study, we exposed the green microalga Dunaliella tertiolecta to OA concentrations of 0.05 to 0.5 {mu}M in order to evaluate its effects on cell division, reactive oxygen species production and photosynthetic electron transport. After 72 h of treatment under continuous illumination, OA concentrations higher than 0.10 {mu}M decreased culture cell density, induced oxidative stress and inhibited photosystem II electron transport capacity. OA effect in D. tertiolecta was strongly light dependent since no oxidative stress was observed when D. tertiolecta was exposed to OA in the dark. In the absence of light, the effect of OA on culture cell density and photosystem II activity was also significantly reduced. Therefore, light appears to have a significant role in the toxicity of OA in microalgae. Our results indicate that the site of OA interaction on photosynthetic electron transport is likely to be at the level of the plastoquinone pool, which can lead to photo-oxidative stress when light absorbed by the light-harvesting complex of photosystem II cannot be dissipated via photochemical pathways. These findings allowed for a better understanding of the mechanisms of OA toxicity in microalgae. - Highlights: Black-Right-Pointing-Pointer Exposition of Dunaliella tertiolecta to okadaic acid in light conditions results in reactive oxygen species formation. Black-Right-Pointing-Pointer Inhibition of photosystem II is dependent on oxidative stress and effects of okadaic acid on the plastoquinone pool. Black-Right-Pointing-Pointer Oxidative stress and inhibition of photosynthesis increase okadaic acid effect on cell density in light conditions. Black-Right-Pointing-Pointer Okadaic acid induces toxicity in algae via both light-dependent and light

  15. Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, California

    Science.gov (United States)

    Burton, Carmen

    2018-05-30

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The shallow aquifers of the groundwater basins around Monterey Bay, the Salinas Valley, and the highlands adjacent to the Salinas Valley constitute one of the study units.

  16. Marine myxobacteria as a source of antibiotics--comparison of physiology, polyketide-type genes and antibiotic production of three new isolates of Enhygromyxa salina.

    Science.gov (United States)

    Schäberle, Till F; Goralski, Emilie; Neu, Edith; Erol, Ozlem; Hölzl, Georg; Dörmann, Peter; Bierbaum, Gabriele; König, Gabriele M

    2010-09-03

    Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1(T) as their closest homolog, displaying between 98% (SWB005) and 99% (SWB004 and SWB006) sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE).

  17. Marine Myxobacteria as a Source of Antibiotics—Comparison of Physiology, Polyketide-Type Genes and Antibiotic Production of Three New Isolates of Enhygromyxa salina

    Directory of Open Access Journals (Sweden)

    Gabriele Bierbaum

    2010-09-01

    Full Text Available Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1T as their closest homolog, displaying between 98% (SWB005 and 99% (SWB004 and SWB006 sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA and Staphylococcus epidermidis (MRSE.

  18. Ecology of a heterotrichous ciliate Fabrea salina from salterns of Bombay Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Rattan, P.; Ansari, Z.A.; Sreepada, R.A.

    The abundance and population size structure of a heterotrichous ciliate @iFabrea salina@@, was studied in relation to hydrochemical and hydrobiological variables in three hypersaline ponds of Bombay, west coast of India There was a clear seasonal...

  19. Cultivation of Nannochloropsis salina using anaerobic digestion effluent as a nutrient source for biofuel production

    International Nuclear Information System (INIS)

    Cai, Ting; Park, Stephen Y.; Racharaks, Ratanachat; Li, Yebo

    2013-01-01

    Highlights: • Cultivation of Nannochloropsis salina with effluent of anaerobic digestion (AD). • The highest biomass yield was obtained at 6% AD effluent loading. • Lipid content and productivity decreased with increased effluent loading from 3% to 18%. • Biomass productivity increased by up to 49% as harvest ratio increased from 25% to 50%. - Abstract: The biomass and lipid productivities and the nutrient removal capacity of microalgae Nannochloropsis salina grown using anaerobically digested municipal wastewater effluent as a nutrient source were evaluated in this study. Results from bench-scale batch reactors showed that N. salina grew well under 3%, 6%, 12%, and 18% (v/v) anaerobic digestion (AD) effluent loading with the highest growth rate being 0.645 d −1 obtained at 6% AD effluent loading. The growth of N. salina decreased when the effluent loading was increased to 24%. The highest biomass productivity of 92 mg l −1 d −1 was obtained with 6% effluent loading. Three harvesting frequencies (1, 2, and 3 d intervals) and two harvesting ratios (25% and 50%, v/v) were tested in semi-continuous bench-scale reactors with 6% effluent loading. The highest lipid productivity of 38.7 mg l −1 d −1 was achieved with a 2-d harvesting interval and 50% harvesting ratio, where nitrogen and phosphorus were removed at rates of 35.3 mg l −1 d −1 and 3.8 mg l −1 d −1 , respectively. The fatty acid (FA) profile showed that palmitic acid (C16:0), palmitoleic acid (C16:1), and eicosapentaenoic acid (C20:5) were the major components, accounting for 32.1%, 26%, and 15.7% of the total FAs, respectively

  20. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    International Nuclear Information System (INIS)

    Anderson, B.S.; Phillips, B.M.; Hunt, J.W.; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2006-01-01

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River

  1. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  2. Dichotomosiphon salina sp. nov. - a new marine algal form from Goa estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Jagtap, T.G.; Dhargalkar, V.K.

    A new species Dichotomosiphon salina sp. of family Vaucheriaceae has been reported from brackish water areas of Goa. The high salinity tolerance of 40 ppt and the variation in size as well as shape of the reproductive organs are the main...

  3. Analysis of toxicity of Anacardium occidentale L. extract submitted to ionizing radiation on embryos of Biomphalaria glabrata and Artemia salina

    International Nuclear Information System (INIS)

    Silva, Hianna A.M.F.; Sa, Jose L.F.; Lima, Claudia S.A.; Amancio, Francisco F.; Melo, Ana M.M.A.; Ribeiro, Luanna R.S.; Santos, Gustavo H.F.; Silva, Edvane B.

    2013-01-01

    The use of gamma radiation as a sterilization method for herbs, herbal medicines and foods, shows positive results regarding the retention of such products, economy and safety of the method. However, it is known that this method of processing plant material can cause chemical changes in these products related to the type of material, its components and the dose received. Evaluated, in the present study, the action of gamma radiation as a modifier of toxicity extract of Anacardium occidentale Linn. To evaluate the toxicity of the extract irradiated at doses of 5.0, 7.5 and 10.0 kGy and concentrations of 250, 500 and 1000 mg/L was used bioassays with Artemia salina and Biomphalaria glabrata. For the test to A. salina, 520 specimens were used divided into groups of 10 larvae. For the bioassay with B. glabrata, 3900 specimens were used divided into groups of, approximately, 100 embryos. Larvae of A. salina and embryos were subjected to extracts irradiated and unirradiated for 24 hours. The bioassay with A. salina, showed a decrease, compared to extract unirradiated and irradiated at doses of 5.0 and 7.5 kGy, of extract irradiated with 10 kGy, where the mortality did not differ from the control group. In tests with embryos was observed an increase in the toxicity of the extract at a dose of 7.5 kGy and a decrease in the dose of 10.0 kGy. The radiation promoted changes in the toxicity of leaves extracts of Anacardium occidentale Linn. on embryos of Biomphalaria glabrata and Artemia salina. (author)

  4. Analysis of toxicity of Anacardium occidentale L. extract submitted to ionizing radiation on embryos of Biomphalaria glabrata and Artemia salina

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Hianna A.M.F.; Sa, Jose L.F.; Lima, Claudia S.A.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: hiannaamfs@gmail.com, E-mail: luismuma6@gmail.com, E-mail: claudia.salima@gmail.com, E-mail: amancioff@bol.com.br, E-mail: amdemelo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia; Ribeiro, Luanna R.S.; Santos, Gustavo H.F.; Silva, Edvane B., E-mail: luannaribeiro_lua@hotmail.com, E-mail: santosghf@hotmail.com, E-mail: edvborges@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia

    2013-07-01

    The use of gamma radiation as a sterilization method for herbs, herbal medicines and foods, shows positive results regarding the retention of such products, economy and safety of the method. However, it is known that this method of processing plant material can cause chemical changes in these products related to the type of material, its components and the dose received. Evaluated, in the present study, the action of gamma radiation as a modifier of toxicity extract of Anacardium occidentale Linn. To evaluate the toxicity of the extract irradiated at doses of 5.0, 7.5 and 10.0 kGy and concentrations of 250, 500 and 1000 mg/L was used bioassays with Artemia salina and Biomphalaria glabrata. For the test to A. salina, 520 specimens were used divided into groups of 10 larvae. For the bioassay with B. glabrata, 3900 specimens were used divided into groups of, approximately, 100 embryos. Larvae of A. salina and embryos were subjected to extracts irradiated and unirradiated for 24 hours. The bioassay with A. salina, showed a decrease, compared to extract unirradiated and irradiated at doses of 5.0 and 7.5 kGy, of extract irradiated with 10 kGy, where the mortality did not differ from the control group. In tests with embryos was observed an increase in the toxicity of the extract at a dose of 7.5 kGy and a decrease in the dose of 10.0 kGy. The radiation promoted changes in the toxicity of leaves extracts of Anacardium occidentale Linn. on embryos of Biomphalaria glabrata and Artemia salina. (author)

  5. Phototactic orientation mechanism in the ciliate Fabrea salina, as inferred from numerical simulations.

    Science.gov (United States)

    Marangoni, R; Preosti, G; Colombetti, G

    2000-02-01

    The marine ciliate Fabrea salina shows a clear positive phototaxis, but the mechanism by which a single cell is able to detect the direction of light and orient its swimming accordingly is still unknown. A simple model of phototaxis is that of a biased random walk, where the bias due to light can affect one or more of the parameters that characterize a random walk, i.e., the mean speed, the frequency distribution of the angles of directional changes and the frequency of directional changes. Since experimental evidence has shown no effect of light on the mean speed of Fabrea salina, we have excluded models depending on this parameter. We have, therefore, investigated the phototactic orientation of Fabrea salina by computer simulation of two simple models, the first where light affects the frequency distribution of the angles of directional changes (model M1) and the second where the light bias modifies the frequency of directional changes (model M2). Simulated M1 cells directly orient their swimming towards the direction of light, regardless of their current swimming orientation; simulated M2 cells, on the contrary, are unable to actively orient their motion, but remain locked along the light direction once they find it by chance. The simulations show that these two orientation models lead to different macroscopic behaviours of the simulated cell populations. By comparing the results of the simulations with the experimental ones, we have found that the phototactic behaviour of real cells is more similar to that of the M2 model.

  6. Bioactivity evaluation against Artemia salina Leach of medicinal plants used in Brazilian Northeastern folk medicine.

    Science.gov (United States)

    Arcanjo, D D R; Albuquerque, A C M; Melo-Neto, B; Santana, L C L R; Medeiros, M G F; Citó, Amgl

    2012-08-01

    The brine shrimp (Artemia salina Leach) lethality bioassay offers an advantage in standardization and quality control of botanical products. This test is well correlated with antitumor activity (cytotoxicity) and can be used to monitor the activity of bioactive natural products. This paper reports the bioactivity of ethanol extracts from seven medicinal plants from the Northeast of Brazil (Acmella uliginosa, Ageratum conyzoides, Eugenia uniflora, Plectranthus neochilus, Moringa oleifera, Justicia pectoralis and Equisetum sp.) against Artemia salina. Biological activity was evaluated for extracts at 1, 10, 100, and 1000 µg/mL in triplicate, and the mean lethal concentration values (LC50) were obtained by probit analysis. The species Acmella uliginosa showed the highest bioactivity, and its flower extract was more active than its leaf extract.

  7. The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools.

    Science.gov (United States)

    Madadkar Haghjou, Maryam; Colville, Louise; Smirnoff, Nicholas

    2014-11-01

    The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Pastas de Rhodomonas salina (Cryptophyta como alimento para Brachionus plicatilis (Rotifera

    Directory of Open Access Journals (Sweden)

    Miguel Guevara

    2011-12-01

    Full Text Available Pastas de Rhodomonas salina, obtenidas mediante centrifugación y floculación con quitosano y preservadas con o sin vitamina C, a -20°C fueron evaluadas bioquímicamente y proporcionadas como alimento al rotífero Brachionus plicatilis. Las pastas microalgales: (1 centrifugada y con vitamina C (CV, (2 centrifugada y sin vitamina C (C, (3 floculada y con vitamina C (FV y (4 floculada y sin adición de vitamina C (F; mantuvieron sus contenidos de proteínas y lípidos totales similares al cultivo control, con valores de 40.0±2.32% y 12.0±1.45%, respectivamente. La relación feofitina a/clorofila a fue similar (0.09-0.11 entre las pastas centrifugadas y el cultivo control, pero mayor en las pastas floculadas (1.28-1.48. Las pastas centrifugadas presentaron porcentajes de PUFAs totales, EPA y DHA similares al cultivo control (PUFAs: 47%, EPA: 4% y DHA: 4.7% y superiores al de las pastas floculadas. Las pastas obtenidas por centrifugación indujeron un crecimiento del rotífero igual al obtenido con el alimento control (densidad máxima: 320rotíferos/mL; tasa instantánea de crecimiento: 0.23rotíferos/día, fecundidad: 1.49huevos/ hembra y productividad: 43x103rotíferos/L/día. Se concluye que la pasta de R. salina centrifugada y congelada a -20°C, durante cuatro semanas, sin adición de vitamina C, mantiene su calidad nutricional similar a la del alga fresca y puede ser usada como alimento de Brachionus plicatilis.Rhodomonas salina (Cryptophyta pastes as feed for Brachionus plicatilis (Rotifera. Rotifers are an important live feed for first feeding larvae of many fish species. The use of concentrated algae cells in the mass culture of the rotifer Brachionus plicatilis (Brachionidae has opened new horizons for research on this organism. Pastes of Rhodomonas salina (Pyrenomonadaceae obtained either by centrifugation or flocculation with chitosan were preserved, with or without vitamin C, at -20°C for four weeks and were evaluated

  9. Etude de stratégies de culture de Dunaliella tertiolecta combinant haute densité cellulaire et accumulation de lipides en vue de produire du biodiesel

    Directory of Open Access Journals (Sweden)

    Massart, A.

    2010-01-01

    Full Text Available Study of culture strategies of Dunaliella tertiolecta combining high cell density and accumulation of lipids to produce biodiesel. Microalgae are photosynthetic organisms using light to capture CO2. Some species can accumulate, under specific growth conditions, carbon as lipids (triglycerides. This characteristic led the scientists to think about cultivating this microorganism to produce biodiesel. The following study is based on the cultivation of a 5 to 10 µm length green biflagellate microalgae, Dunaliella tertiolecta. Two objectives will be presented in parallel: first, the growth rate and then the oil content. An optimal design of experiment has been used to determine the influence of the concentration of different components in the medium as sodium chloride, nitrate and phosphate on the two responses. The fluorescence technique allows measurements of oil level within the microalgae. The experimental results show that increasing the growth leads to an oil level reduction. The sudden depletion (stress of an essential nutrient stops the growth but increase the lipids' storage. A nitrate stress allows lipid dry mass percentage of around 19%.

  10. [Rhodomonas salina (Cryptophyta) pastes as feed for Brachionus plicatilis (Rotifera)].

    Science.gov (United States)

    Guevara, Miguel; Bastardo, Leandro; Cortez, Roraysi; Arredondo-Vega, Bertha; Romero, Lolymar; Gómez, Patricia

    2011-12-01

    Rotifers are an important live feed for first feeding larvae of many fish species. The use of concentrated algae cells in the mass culture of the rotifer Brachionus plicatilis (Brachionidae) has opened new horizons for research on this organism. Pastes of Rhodomonas salina (Pyrenomonadaceae) obtained either by centrifugation or flocculation with chitosan were preserved, with or without vitamin C, at -20 degrees C for four weeks and were evaluated biochemically (proteins, lipids, pigments and fatty acids contents) and subsequently, were used to feed the rotifer Brachionus plicatilis at a ratio of 25 mg/L/day. Four different microalgae pastes were prepared: (1) centrifuged and preserved with vitamin C (CV), (2) centrifuged and preserved without vitamin C (C), (3) flocculated and with vitamin C (FV) and (4) flocculated without vitamin C (F). All treatments showed similar contents of proteins and total lipids with respect to control culture (a fresh culture of R. salina), with mean values of 40.0 +/- 2.32% and 12.0 +/- 1.45%, respectively. The pheophytin a/chlorophyll a ratio, a general indicator of the chemical status of microalgal concentrates, was similar (0.09-0.11) between centrifuged pastes and control culture, but was found to be higher in flocculated pastes (1.28-1.48). The fatty acid profile varied with respect to the control culture, mainly in the proportion of the essential polyunsaturated fatty acids (PUFAs): eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Total PUFAs, EPA and DHA contents were statistically similar between centrifuged pastes and control culture (PUFAs: 47%, EPA: 4% and DHA: 4.7%), whereas values obtained for flocculated pastes were significantly lower. The rotifers grew equally well when fed with centrifuged pastes or control culture (maximum density: 320 rotifers/mL; instantaneous growth rate: 0.23 rotifers/day, fecundity: 1.49 eggs/female and productivity: 43 x 10(3) rotifers/L/day. No significant effect of vitamin C was

  11. A century of plant virus management in the Salinas valley of California, 'East of Eden'.

    Science.gov (United States)

    Wisler, G C; Duffus, J E

    2000-11-01

    The mild climate of the Salinas Valley, CA lends itself well to a diverse agricultural industry. However, the diversity of weeds, crops and insect and fungal vectors also provide favorable conditions for plant virus disease development. This paper considers the incidence and management of several plant viruses that have caused serious epidemics and been significant in the agricultural development of the Salinas Valley during the 20th century. Beet curly top virus (BCTV) almost destroyed the newly established sugarbeet industry soon after its establishment in the 1870s. A combination of resistant varieties, cultural management of beet crops to provide early plant emergence and development, and a highly coordinated beet leafhopper vector scouting and spray programme have achieved adequate control of BCTV. These programmes were first developed by the USDA and still operate. Lettuce mosaic virus was first recognized as causing a serious disease of lettuce crops in the 1930s. The virus is still a threat but it is controlled by a lettuce-free period in December and a seed certification programme that allows only seed lots with less than one infected seed in 30000 to be grown. 'Virus Yellows' is a term used to describe a complex of yellows inducing viruses which affect mainly sugarbeet and lettuce. These viruses include Beet yellows virus and Beet western yellows virus. During the 1950s, the complex caused significant yield losses to susceptible crops in the Salinas Valley. A beet-free period was introduced and is still used for control. The fungus-borne rhizomania disease of sugarbeet caused by Beet necrotic yellow vein virus was first detected in Salinas Valley in 1983. Assumed to have been introduced from Europe, this virus has now become widespread in California wherever beets are grown and crop losses can be as high as 100%. Movement of infested soil and beets accounts for its spread throughout the beet-growing regions of the United States. Control of rhizomania

  12. New procedure for extraction of algal lipids from wet biomass: a green clean and scalable process.

    Science.gov (United States)

    Dejoye Tanzi, Celine; Abert Vian, Maryline; Chemat, Farid

    2013-04-01

    A new procedure, called Simultaneous Distillation and Extraction Process (SDEP), for lipid extraction from wet microalgae (Nannochloropsis oculata and Dunaliella salina) was reported. This method does not require a pre-drying of the biomass and employs alternative solvents such as d-limonene, α-pinene and p-cymene. This procedure has been compared with Soxhlet extraction (Sox) and Bligh & Dyer method (B&D). For N. oculata, results showed that SDEP-cymene provided similar lipid yields to B&D (21.45% and 23.78%), while SDEP-limonene and pinene provided lower yields (18.73% and 18.75% respectively). For D. salina, SDEP-pinene provided the maximum lipid yield (3.29%) compared to the other solvents, which is quite close to B&D result (4.03%). No significant differences in terms of distribution of lipid classes and fatty acid composition have been obtained for different techniques. Evaluation of energy consumption indicates a substantial saving in the extraction cost by SDEP compared to the conventional extraction technique, Soxhlet. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Not yet? Ya basta: Healing and the horizons of an otherwise in Salinas, California

    NARCIS (Netherlands)

    Raschig, M.S.

    2016-01-01

    Among a persistently criminalized population of Mexican-Americans in the farmtown-gangland of Salinas, California, healing from the wounds of history has emerged as a critical register of political action, a tacit and uncertain activism recalibrating the pace and tense of personal recoveries and

  14. Determining surface areas of marine alga cells by acid-base titration method.

    Science.gov (United States)

    Wang, X; Ma, Y; Su, Y

    1997-09-01

    A new method for determining the surface area of living marine alga cells was described. The method uses acid-base titration to measure the surface acid/base amount on the surface of alga cells and uses the BET (Brunauer, Emmett, and Teller) equation to estimate the maximum surface acid/base amount, assuming that hydrous cell walls have carbohydrates or other structural compounds which can behave like surface Brönsted acid-base sites due to coordination of environmental H2O molecules. The method was applied to 18 diverse alga species (including 7 diatoms, 2 flagellates, 8 green algae and 1 red alga) maintained in seawater cultures. For the species examined, the surface areas of individual cells ranged from 2.8 x 10(-8) m2 for Nannochloropsis oculata to 690 x 10(-8) m2 for Dunaliella viridis, specific surface areas from 1,030 m2.g-1 for Dunaliella salina to 28,900 m2.g-1 for Pyramidomonas sp. Measurement accuracy was 15.2%. Preliminary studies show that the method may be more promising and accurate than light/electron microscopic measurements for coarse estimation of the surface area of living algae.

  15. Aspects of chemoattractant recognition by the alga Dunaliella tertiolecta

    International Nuclear Information System (INIS)

    Millard, P.J.

    1984-01-01

    Studies on the molecular nature of algal chemotaxis were performed using the halophilic chlorophyte Dunaliella tertiolecta as a model. Several physical and chemical parameters for generation of maximum chemotactic response in capillary assays are described. Inhibition of chemotaxis to NH 4 + and several aromatic amino acid by sublethal concentrations of certain heavy metals, including Zn 2+ , Co 2+ , Ni 2+ , Cu 2+ , and Hg 2+ is demonstrated. Inhibition by Zn 2 of the response of NH 4 + is partially reversed by increased concentrations of Ca 2+ . Attraction of L-phenylalanine, L-tyrosine, L-tryptophan, their structural analogs, and other compounds has been quantified using a capillary assay. Radiolabeled L-phenylalanine was used as a ligand to investigate algal binding and uptake. No internalization of the amino acid by D. tertiolectra occurred, even after 3 hr. Specific binding of 3 H-L-phenylalanine was below 100 molecules per alga at 10 -8 M L-phenylalanine. No evidence for the alteration of L-phenylalnine by D. tertiolecta was found following 22 hr incubation with the substrate in light or darkness. To further probe the molecular components of the chemosensory system of D. tertiolecta, a procedure for isolation and purification of trinitrobenzene sulfonic acid (TNBS)-labeled plasma membrane vesicles was developed. Plasma membrane purity was assessed by criteria of chlorophyll content, succinic dehydrogenase activity and protein pattern

  16. Morphological changes about Artemia Salina by the effect of gamma radiation

    International Nuclear Information System (INIS)

    Dvorak, P.; Kunova, V; Kratochvil, B.; Salplachta, J.; Benova, K.

    2004-01-01

    Direction Council of Europe require restriction of laboratory vertebrae in biological experiments. Once by possibilities is using biological test II. generation among which belongs to and test for Artemia salina. Still this time published test however value only lethality in dependence on dose, exposition and time survival. This work document possibility watch of expressive morphological changes, which consist in retardation development brine shrimps stage in dependence on dose gamma radiation 60 Co. (authors)

  17. Evaluation of hydrologic conditions and nitrate concentrations in the Rio Nigua de Salinas alluvial fan aquifer, Salinas, Puerto Rico, 2002-03

    Science.gov (United States)

    Rodriguez, Jose M.

    2006-01-01

    A ground-water quality study to define the potential sources and concentration of nitrate in the Rio Nigua de Salinas alluvial fan aquifer was conducted between January 2002 and March 2003. The study area covers about 3,600 hectares of the coastal plain within the municipality of Salinas in southern Puerto Rico, extending from the foothills to the Caribbean Sea. Agriculture is the principal land use and includes cultivation of diverse crops, turf grass, bioengineered crops for seed production, and commercial poultry farms. Ground-water withdrawal in the alluvial fan was estimated to be about 43,500 cubic meters per day, of which 49 percent was withdrawn for agriculture, 42 percent for public supply, and 9 percent for industrial use. Ground-water flow in the study area was primarily to the south and toward a cone of depression within the south-central part of the alluvial fan. The presence of that cone of depression and a smaller one located in the northeastern quadrant of the study area may contribute to the increase in nitrate concentration within a total area of about 545 hectares by 'recycling' ground water used for irrigation of cultivated lands. In an area that covers about 405 hectares near the center of the Salinas alluvial fan, nitrate concentrations increased from 0.9 to 6.7 milligrams per liter as nitrogen in 1986 to 8 to 12 milligrams per liter as nitrogen in 2002. Principal sources of nitrate in the study area are fertilizers (used in the cultivated farmlands) and poultry farm wastes. The highest nitrogen concentrations were found at poultry farms in the foothills area. In the area of disposed poultry farm wastes, nitrate concentrations in ground water ranged from 25 to 77 milligrams per liter as nitrogen. Analyses for the stable isotope ratios of nitrogen-15/nitrogen-14 in nitrate were used to distinguish the source of nitrate in the coastal plain alluvial fan aquifer. Potential nitrate loads from areas under cultivation were estimated for the

  18. Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, Southern Coast Ranges, California

    Science.gov (United States)

    Burton, Carmen

    2018-05-30

    The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

  19. Radiobiological and radioecological studies with the unicellular marine algae Acetabularia, Batophora and Dunaliella

    International Nuclear Information System (INIS)

    Bonotto, S.; Luttke, A.; Strack, S.; Kirchmann, R.; Hoursiangou, D.; Puiseux-Dao, S.

    1980-01-01

    The biological effects of X-rays on the unicellular marine algae Acetabularia mediterranea, Acetabularia peniculus and Batophora oerstedii were studied. Increasing doses of X-rays (0 to 150 kr) were shown to interfere with the main morphogenetic processes of these algae. Labelling experiments with 3 H-thymidine, 3 H-uridine and 3 H-leucine showed that X-rays (50 kr) provoked a strong reduction of DNA, RNA and protein synthesis in the chloroplasts of A. mediterranea. Radioecological studies were also performed showing that Acetabularia cells, grown in the presence of HTO, incorporate a significant amount of 3 H in the total nucleic acid and protein fraction. However, 3 H supplied to Acetabularia in the form of tritiated water was not accumulated. When organically bound 3 H was supplied to Acetabularia or to Dunaliella, a selective accumulation of some substances was observed. Thus the results of this study illustrate the impact of radiation on living organisms and the biological behaviour of 3 H in the aquatic system. (UK)

  20. The Biodiesel of Microalgae as a Solution for Diesel Demand in Iran

    Directory of Open Access Journals (Sweden)

    Afshin Ghorbani

    2018-04-01

    Full Text Available Among the fossil fuels, diesel has the major share in petroleum product consumption. Diesel demand in Iran has increasingly grown due to the low price of diesel, a high subsidy, and an unsuitable consumption pattern. During 2006–2007, this growth imposed 2.2 billion liters of imports, which were equivalent to 7.5% of diesel production in 2007 and cost about $1.2 billion. Therefore, the government implemented fuel rationing in 2007 and a targeted subsidy law in 2010. These projects have not gained effective control of consumption due to the wide gap between the international diesel price and the domestic price. Diesel import after the implementation of fuel rationing and the targeted subsidy law in 2011 imposed 3.6 billion liters of import and cost about $2.2 billion. Therefore, the government will need fundamental strategies and policies to face and control the negative impact on the economy and the environment. Third generation fuels, biofuels, as another supplementary approach seems to have the capability to reduce the petroleum requirement. This paper investigates the potential of biodiesel as diesel alternative fuel from oil seeds and microalgae in Iran along with evaluating the policy for reducing diesel consumption. Dunaliella salina as an indigenous green microalga isolated from the Maharlu Salt Lake was cultivated in an integration of an airlift system and a raceway pond (IARWP to prove microalgal potentials in Iran. Additionally, the natural culture medium from the Maharlu Salt Lake was utilized for Dunaliella salina in order to commercialize and reduce cultivation cost. Compared to oilseeds, microalgae because of their high lipid content have much potential to solve a fuel consumption problem. This paper found that only 21 percent of cultivable land is needed to replace the diesel currently consumed in Iran with microalgal biodiesel.

  1. High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae

    International Nuclear Information System (INIS)

    Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

    2015-01-01

    Highlights: • Carbon-based nanomaterials adsorb onto the body surface of A. salina larvae. • Surface adsorption results in concentration–dependent inhibition of larval swimming. • Carbon-based nanomaterials induce no significant mortality of A. salina larvae. - Abstract: We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration–dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5 mg/mL carbon black and 0.1 mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change

  2. High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae

    Energy Technology Data Exchange (ETDEWEB)

    Mesarič, Tina, E-mail: tina.mesaric84@gmail.com [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Gambardella, Chiara, E-mail: chiara.gambardella@ge.ismar.cnr.it [Institute of Marine Sciences, National Research Council, Genova (Italy); Milivojević, Tamara, E-mail: milivojevictamara@gmail.com [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Faimali, Marco, E-mail: marco.faimali@ismar.cnr.it [Institute of Marine Sciences, National Research Council, Genova (Italy); Drobne, Damjana, E-mail: damjana.drobne@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Centre of Excellence in Nanoscience and Nanotechnology (CO Nanocentre), Ljubljana (Slovenia); Centre of Excellence in Advanced Materials and Technologies for the Future (CO NAMASTE), Ljubljana (Slovenia); Falugi, Carla, E-mail: carlafalugi@hotmail.it [Department of Earth, Environment and Life Sciences, University of Genova, Genova (Italy); Makovec, Darko, E-mail: darko.makovec@ijs.si [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Jemec, Anita, E-mail: anita.jemec@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Sepčić, Kristina, E-mail: kristina.sepcic@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia)

    2015-06-15

    Highlights: • Carbon-based nanomaterials adsorb onto the body surface of A. salina larvae. • Surface adsorption results in concentration–dependent inhibition of larval swimming. • Carbon-based nanomaterials induce no significant mortality of A. salina larvae. - Abstract: We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration–dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5 mg/mL carbon black and 0.1 mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change.

  3. Acclimation and tolerance of Artemia salina to copper salts

    Energy Technology Data Exchange (ETDEWEB)

    Saliba, L.J.; Krzyz, R.M.

    1976-01-01

    The brine shrimp Artemia salina L. was acclimated in sea water with cupric chloride, acetate, carbonate, and sulfate, each at concentrations of 0.1, 0.05 and 0.025 ppM Cu/sup + +/, together with sea water controls. Growth inhibition was observed in all four compounds, generally in direct relationship to the concentration. It was least in sulfate, and increased progressively in chloride, acetate and carbonate in that order. In toxicity tests, 2-week old larvae from each solution were exposed to concentrations of 10, 7.5, 5, 2.5 and 1 ppM Cu/sup + +/ of the same compounds, together with unacclimated larvae of the same age. Similar tests were held with 6-week old adults. Toxicity to unacclimated larvae and adults differed with the compounds, carbonate being the least toxic, followed by sulfate, chloride and acetate in increasing order. Larvae acclimated in chloride and sulfate showed an increased tolerance to 1 and 2.5 ppM Cu/sup + +/ compared to untreated controls. Tolerance was not enhanced from 5 ppM Cu/sup + +/ upwards. In both compounds, adults acclimated in 0.1 ppM Cu/sup + +/ showed an increased tolerance to concentrations between 1 and 7.5 ppM Cu/sup + +/ compared to controls. Considerable precipitation occurred with the high levels of this compound, thus effecting the ''final'' concentrations. No acclimation effect was observed in acetate for either larvae or adults. It is suggested that in A. salina, copper toxicity depends on the particular form of the metal, and that this difference is also evident in growth inhibition and in the potential acquisition of increased tolerance through exposure to low concentrations.

  4. Pesticide Risk Communication, Risk Perception, and Self-Protective Behaviors among Farmworkers in California's Salinas Valley

    Science.gov (United States)

    Cabrera, Nolan L.; Leckie, James O.

    2009-01-01

    Agricultural pesticide use is the highest of any industry, yet there is little research evaluating farmworkers' understandings of the health risks chemical exposure poses. This study examines pesticide education, risk perception, and self-protective behaviors among farmworkers in California's Salinas Valley. Fifty current and former farmworkers…

  5. Comparative study on toxicity of ZnO and TiO2 nanoparticles on Artemia salina: effect of pre-UV-A and visible light irradiation.

    Science.gov (United States)

    Bhuvaneshwari, M; Sagar, Bhawana; Doshi, Siddharth; Chandrasekaran, N; Mukherjee, Amitava

    2017-02-01

    This study evaluated the toxicity potential of ZnO and TiO 2 nanoparticles under pre-UV-A irradiation and visible light condition on Artemia salina. The nanoparticle suspension was prepared in seawater medium and exposed under pre-UV-A (0.23 mW/cm 2 ) and visible light (0.18 mW/cm 2 ) conditions. The aggregation profiles of both nanoparticles (NPs) and dissolution of ZnO NPs under both irradiation conditions at various kinetic intervals (1, 24, 48 h) were studied. The 48-h LC 50 values were found to be 27.62 and 71.63 mg/L for ZnO NPs and 117 and 120.9 mg/L for TiO 2 NPs under pre-UV-A and visible light conditions. ZnO NPs were found to be more toxic to A. salina as compared to TiO 2 NPs. The enhanced toxicity was observed under pre-UV-A-irradiated ZnO NPs, signifying its phototoxicity. Accumulation of ZnO and TiO 2 NPs into A. salina depends on the concentration of particles and type irradiations. Elimination of accumulated nanoparticles was also evident under both irradiation conditions. Other than ZnO NPs, the dissolved Zn 2+ also had a significant effect on toxicity and accumulation in A. salina. Increased catalase (CAT) activity in A. salina indicates the generation of oxidative stress due to NP interaction. Thus, this study provides an understanding of the toxicity of photoreactive ZnO and TiO 2 NPs as related to the effects of pre-UV-A and visible light irradiation.

  6. Estudo fitoquímico preliminar e bioensaio toxicológico frente a larvas de Artemia salina Leach. de extrato obtido de frutos de Solanum lycocarpum A. St.-Hill (Solanaceae

    Directory of Open Access Journals (Sweden)

    Marcelo Gonzaga de Freitas Araújo

    2010-11-01

    Full Text Available

    Neste trabalho avaliou-se o perfil fitoquímico e a toxicidade preliminar frente a larvas de Artemia salina do extrato etanólico de frutos de Solanum lycocarpum. O extrato foi submetido à analise fitoquímica preliminar para identificação das principais classes de metabolitos secundários presentes e testado frente a larvas de A. salina para obtenção das concentrações letais médias (CL50%. Os testes fitoquímicos demonstraram a presença de fenóis, taninos, saponinas, alcalóides e esteróides e triterpenos livres. O extrato foi fracionado em diferentes solventes para a avaliação da toxicidade frente à A. salina, apresentando considerável citotoxicidade encontrada na fração hidroalcoólica (CL50% = 285,546 µg/mL. Palavras-chave: Solanum lycocarpum, Artemia salina, triagem fitoquímica preliminar. ABSTRACT The phytochemical profile of ethanolic extract of Solanum lycocarpum fruits was analyzed and preliminary toxicity tests were performed against brine shrimp larvae. The extract was subjected to preliminary phytochemical analysis to identify the main classes of secondary metabolites and tested against the larvae of A. salina to obtain the median lethal concentrations (LC50%. The phytochemical tests showed the presence of phenols, tannins, saponins, alkaloids and free steroids. The extract was fractionated with various solvents for toxicity testing against the larvae and the hydroalcoholic fraction showed considerable cytotoxicity (CL50% = 285.546 g/mL. Keywords: Solanum lycocarpum, Artemia salina, phytochemical screening

  7. Construcción macrotextual y cancionero amoroso (Un acercamiento analítico a "La voz a ti debida" de Pedro Salinas)

    OpenAIRE

    Corencia Cruz, Joaquín

    2008-01-01

    La tesis Construcción macrotextual y cancionero amoroso. Unacercamiento analítico a La voz a ti debida de Pedro Salinas. Fue leídapor Joaquín Corencia Cruz en la Sala de Juntas de la Facultad deFilología de la Universidad de Valencia (España) el 7 de noviembre de2008.El trabajo investigador se desarrolla a lo largo de nuevecapítulos. En el primero se produce una introducción a la tesisrevisando desde la trayectoria vital y profesional de Pedro Salinas acómo el macrotexto poético de La voz se ...

  8. Seasonal variability in irradiance affects herbicide toxicity to the marine flagellate Dunaliella tertiolecta

    Directory of Open Access Journals (Sweden)

    Sascha eSjollema

    2014-06-01

    Full Text Available Photosynthetically Active Radiation (PAR and Ultraviolet Radiation (UVR of the solar spectrum affect microalgae directly and modify the toxicity of phytotoxic compounds present in water. As a consequence seasonal variable PAR and UVR levels are likely to modulate the toxic pressure of contaminants in the field. Therefore the present study aimed to determine the toxicity of two model contaminants, the herbicides diuron and Irgarol®1051, under simulated irradiance conditions mimicking different seasons. Irradiance conditions of spring and autumn were simulated with a set of Light Emitting Diodes (LEDs. Toxicity of both herbicides was measured individually and in a mixture by determining the inhibition of photosystem II efficiency (ΦPSII of the marine flagellate Dunaliella teriolecta using Pulse Amplitude Modulation (PAM fluorometry. Toxicity of the single herbicides was higher under simulated spring irradiance than under autumn irradiance and this effect was also observed for mixtures of the herbicides. This irradiance dependent toxicity indicates that herbicide toxicity in the field is seasonally variable. Consequently toxicity tests under standard light conditions may overestimate or underestimate the toxic effect of phytotoxic compounds.

  9. Effects of Light and Temperature on Fatty Acid Production in Nannochloropsis Salina

    Energy Technology Data Exchange (ETDEWEB)

    Van Wagenen, Jonathan M.; Miller, Tyler W.; Hobbs, Samuel J.; Hook, Paul W.; Crowe, Braden J.; Huesemann, Michael H.

    2012-03-12

    Accurate prediction of algal biofuel yield will require empirical determination of physiological responses to the climate, particularly light and temperature. One strain of interest, Nannochloropsis salina, was subjected to ranges of light intensity (5-850 {mu}mol m{sup -2} s{sup -1}) and temperature (13-40 C); exponential growth rate, total fatty acids (TFA) and fatty acid composition were measured. The maximum acclimated growth rate was 1.3 day{sup -1} at 23 C and 250 {mu}mol m{sup -2} s{sup -1}. Fatty acids were detected by gas chromatography with flame ionization detection (GC-FID) after transesterification to corresponding fatty acid methyl esters (FAME). A sharp increase in TFA containing elevated palmitic acid (C16:0) and palmitoleic acid (C16:1) during exponential growth at high light was observed, indicating likely triacylglycerol accumulation due to photo-oxidative stress. Lower light resulted in increases in the relative abundance of unsaturated fatty acids; in thin cultures, increases were observed in palmitoleic and eicosapentaenoeic acids (C20:5{omega}3). As cultures aged and the effective light intensity per cell converged to very low levels, fatty acid profiles became more similar and there was a notable increase of oleic acid (C18:1{omega}9). The amount of unsaturated fatty acids was inversely proportional to temperature, demonstrating physiological adaptations to increase membrane fluidity. This data will improve prediction of fatty acid characteristics and yields relevant to biofuel production.

  10. Use of a nanoplanktonic alga as a test organism in marine molysmology. Some responses of Dunaliella Bioculata Butcher 1959 to gamma irradiation and to chromium and cadmium contamination

    International Nuclear Information System (INIS)

    Peneda-Saraiva, M.C.

    1975-01-01

    Some response of a nanoplanktonic alga, Dunaliella bioculata to gamma irradiation ( 60 Co) and to heavy metal contamination, (chromium and cadmium) used either at strong concentrations (stable isotopes) or as tracers ( 51 Cr) and ( 109 Cd) were studied. The average variation of several biological functions under the effect of these agents was followed: mitotic activity, culture development, cell volume, chlorophyll a and protein concentrations per cell per unit volume (μm 3 ), respiratory and photosynthetic activities, ultrastructure or cytological aspect of the algae. Concentration factors were investigated in cases of contamination. The method used include standard digital counting with a Thoma cell or a particle counter coupled to an amplitude analyser, volume estimation using the hematocrit, pigment determination by acetone extraction, protein determination by the Nessler method. The polarographic method of dissolved oxygen measurement was adapted for successive respiration and photosynthesis experiments on the material concerned. Any Cr and Cd incorporated by Dunaliella bioculata were determined after splitting of the cells and separation of the membranes from the cell contents. The quantity of metal present was measured on each fraction by atomic absorption spectrophotometry [fr

  11. Influencia del medio ambiente en los materiales de construcción III. Dinámica salina

    Directory of Open Access Journals (Sweden)

    Fernández Paris, José Manuel

    1978-06-01

    Full Text Available Las sales y la humedad son los dos factores que condicionan las alteraciones de los materiales de construcción. Los citados materiales, bien de por sí —piedras y ladrillos—, bien una vez endurecidos —morteros y hormigones—, están estructurados por partículas sólidas granulares, separadas por un sistema poroso, que constituye el medio -dinámico para el transporte de las disoluciones salinas procedentes del medio ambiente. La motilidad de las sales a través de la red de poros es función de tres variables físicoclimáticas: temperatura, humedad y condiciones de aireación. La dinámica salina se efectúa mediante procesos de difusión, unas veces de naturaleza química: difusión iónica, otras de naturaleza física: difusión capilar.

  12. Developmental toxicity of oxidized multi-walled carbon nanotubes on Artemia salina cysts and larvae: Uptake, accumulation, excretion and toxic responses.

    Science.gov (United States)

    Zhu, Song; Luo, Fei; Tu, Xiao; Chen, Wei-Chao; Zhu, Bin; Wang, Gao-Xue

    2017-10-01

    Using Artemia salina (A. salina) cysts (capsulated and decapsulated) and larvae [instar I (0-24 h), II (24-48 h) and III (48-72 h)] as experimental models, developmental toxicity of oxidized multi-walled carbon nanotubes (O-MWCNTs) was evaluated. Results revealed that hatchability of capsulated and decapsulated cysts was significantly decreased (p larvae in 600 mg/L. The EC 50 values for swimming inhibition of instar I, II and III were 535, 385 and 472 mg/L, respectively. Instar II showed the greatest sensitivity to O-MWCNTs, and followed by instar III, instar I, decapsulated cysts and capsulated cysts. Effects on hatchability, mortality and swimming were accounted for O-MWCNTs rather than metal catalyst impurities. Body length was decreased with the concentrations increased from 0 to 600 mg/L. O-MWCNTs attached onto the cysts, gill and body surface, resulting in irreversible damages. Reactive oxygen species, malondialdehyde content, total antioxidant capacity and antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) activities were increased following exposure, indicating that the effects were related to oxidative stress. O-MWCNTs were ingested and distributed in phagocyte, lipid vesicle and intestine. Most of the accumulated O-MWCNTs were excreted by A. salina at 72 h, but some still remained in the organism. Data of uptake kinetics showed that O-MWCNTs contents in A. salina were gradually increased from 1 to 48 h and followed by rapidly decreased from 48 to 72 h with a range from 5.5 to 28.1 mg/g. These results so far indicate that O-MWCNTs have the potential to affect aquatic organisms when released into the marine ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Uso da solução salina para manutenção de acessos venosos em adultos: uma revisão

    OpenAIRE

    Oliveira,Francimar Tinoco de; Silva,Lolita Dopico da

    2006-01-01

    Trata-se de uma revisão bibliográfica sobre a prática da salinização em cateteres venosos periféricos. O estudo objetivou analisar os artigos científicos sobre o uso de solução salina na manutenção da permeabilidade de cateteres venosos periféricos em adultos, indexados no MedLine e LILACS no período de 1995 a 2005. A amostra consistiu de 5 artigos os quais foram analisados quanto à procedência e periódico de publicação, ao delineamento do estudo, a amostragem, e ao efeito da solução salina. ...

  14. SALT EFFECTS ON EGGS AND NAUPLII OF ARTEMIA SALINA L

    Science.gov (United States)

    Boone, Eleanor; Baas-Becking, L. G. M.

    1931-01-01

    Eggs of Artemia salina L., the brine shrimp, are easily obtainable in large quantities. Ecdysis takes place in two stages: (a) extrusion of the inner membrane, and (b) ecdysis of the nauplius from that membrane. The conditions which allow for the former are much more varied than those for the latter. Nauplii form in only solutions of a few sodium salts; and, in Mg, Ca, and Sr salts, potassium is very toxic. The possible environment for the nauplii (1 M total molarity) has been ascertained for chlorides of Na, K, Mg, and Ca. The facts observed account for the peculiar distribution of the organism. PMID:19872620

  15. Nitrate Contamination of Deep Aquifers in the Salinas Valley, California

    Science.gov (United States)

    Moran, J. E.; Esser, B. K.; Hillegonds, D. J.; Holtz, M.; Roberts, S. K.; Singleton, M. J.; Visser, A.; Kulongoski, J. T.; Belitz, K.

    2011-12-01

    The Salinas Valley, known as 'the salad bowl of the world', has been an agricultural center for more than 100 years. Irrigated row crops such as lettuce and strawberries dominate both land use and water use. Groundwater is the exclusive supply for both irrigation and drinking water. Some irrigation wells and most public water supply wells in the Salinas Valley are constructed to draw water from deep portions of the aquifer system, where contamination by nitrate is less likely than in the shallow portions of the aquifer system. However, a number of wells with top perforations greater than 75 m deep, screened below confining or semi-confining units, have nitrate concentrations greater than the Maximum Contaminant Limit (MCL) of 45 mg/L as NO3-. This study uses nitrate concentrations from several hundred irrigation, drinking water, and monitoring wells (Monterey County Water Resources Agency, 1997), along with tritium-helium groundwater ages acquired at Lawrence Livermore National Laboratory through the State of California Groundwater Monitoring and Assessment (GAMA) program (reported in Kulongoski et al., 2007 and in Moran et al., in press), to identify nitrate 'hot spots' in the deep aquifer and to examine possible modes of nitrate transport to the deep aquifer. In addition, observed apparent groundwater ages are compared with the results of transport simulations that use particle tracking and a stochastic-geostatistical framework to incorporate aquifer heterogeneity to determine the distribution of travel times from the water table to each well (Fogg et al., 1999). The combined evidence from nitrate, tritium, tritiogenic 3He, and radiogenic 4He concentrations, reveals complex recharge and flow to the capture zone of the deep drinking water wells. Widespread groundwater pumping for irrigation accelerates vertical groundwater flow such that high nitrate groundwater reaches some deep drinking water wells. Deeper portions of the wells often draw in water that recharged

  16. Fine structure and function of the alimentary epithelium in Artemia salina nauplii

    Energy Technology Data Exchange (ETDEWEB)

    Hootman, S R; Conte, F P

    1974-01-01

    The fine structure of the alimentary tract in the second instar nauplius of the brine shrimp, Artemia salina, has been described. The foregut and hindgut of the larva are composed of cuboidal epithelium which is cuticularized. The epithelium of the midgut and gastric caeca is columnar and is characterized by apical microvilli, basal membrane infolds, and abundant mitochondria. The structural characteristics of the midgut cells correlate with previous physiological and biochemical evidence on both adult and larval brine shrimp which indicates that the midgut plays an important role in absorption and osmoregulation in these animals.

  17. Interference from ordinarily used solvents in the outcomes of Artemia salina lethality test

    Directory of Open Access Journals (Sweden)

    Sahgal Geethaa

    2013-01-01

    Full Text Available Methanol, ethanol, Tween 20 and dimethyl sulfoxide (DMSO are widely used as dissolving agents in Artemia salina lethality test (aka brine shrimp lethality test [BSLT] to screen the pharmaceutical properties of natural products. Nevertheless, there is lack of toxicity level of these solvents against brine shrimp. High concentration of these organic solvent might be toxic for this zoology invertebrate and interfere in the experimental outcomes. To avoid this, permissible concentration of the solvents used in BSLT was identified. BSLT was performed to evaluate the toxicity effect of Tween 20, methanol, ethanol and DMSO at 24 h post-treatment time point against A. salina. The suggested maximum working concentration (v/v for DMSO, methanol, ethanol was found to be 1.25% and that for Tween 20 was 0.16%. LC 50 for the solvents were 8.5% (DMSO, 6.4% (methanol, 3.4% (ethanol and 2.5% (Tween 20. The findings have shown a toxicity level among the solvents in descending order as Tween 20 > ethanol > methanol > DMSO. DMSO is a safer solvent to be used in BSLT compared with other tested solvents, whereas Tween 20 has been shown to be the most stringent solvent among the tested solvents. The findings are resourcefully useful to avoid interference of solvents in the assessment of natural products using BSLT.

  18. 97 Etude éco-biologique d'Artémia salina des zones humides de l ...

    African Journals Online (AJOL)

    Grenelle

    l'aviculture de poissons marins [1]. En Algérie, les travaux effectués sur ce crustacé sont relativement rares. Dans le présent ..... dépassent pour certains les normes établies par l'OMS, ce qui peut provoquer le comportement et la dynamique de la reproduction de l'Artémia salina, sans oublier aussi l'action anthropique qui ...

  19. Pastas de Rhodomonas salina (Cryptophyta como alimento para Brachionus plicatilis (Rotifera

    Directory of Open Access Journals (Sweden)

    Miguel Guevara

    2011-12-01

    Full Text Available Pastas de Rhodomonas salina, obtenidas mediante centrifugación y floculación con quitosano y preservadas con o sin vitamina C, a -20°C fueron evaluadas bioquímicamente y proporcionadas como alimento al rotífero Brachionus plicatilis. Las pastas microalgales: (1 centrifugada y con vitamina C (CV, (2 centrifugada y sin vitamina C (C, (3 floculada y con vitamina C (FV y (4 floculada y sin adición de vitamina C (F; mantuvieron sus contenidos de proteínas y lípidos totales similares al cultivo control, con valores de 40.0±2.32% y 12.0±1.45%, respectivamente. La relación feofitina a/clorofila a fue similar (0.09-0.11 entre las pastas centrifugadas y el cultivo control, pero mayor en las pastas floculadas (1.28-1.48. Las pastas centrifugadas presentaron porcentajes de PUFAs totales, EPA y DHA similares al cultivo control (PUFAs: 47%, EPA: 4% y DHA: 4.7% y superiores al de las pastas floculadas. Las pastas obtenidas por centrifugación indujeron un crecimiento del rotífero igual al obtenido con el alimento control (densidad máxima: 320rotíferos/mL; tasa instantánea de crecimiento: 0.23rotíferos/día, fecundidad: 1.49huevos/ hembra y productividad: 43x103rotíferos/L/día. Se concluye que la pasta de R. salina centrifugada y congelada a -20°C, durante cuatro semanas, sin adición de vitamina C, mantiene su calidad nutricional similar a la del alga fresca y puede ser usada como alimento de Brachionus plicatilis.

  20. Biotechnological potential of Synechocystis salina co-cultures with selected microalgae and cyanobacteria: Nutrients removal, biomass and lipid production.

    Science.gov (United States)

    Gonçalves, Ana L; Pires, José C M; Simões, Manuel

    2016-01-01

    Cultivation of microalgae and cyanobacteria has been the focus of several research studies worldwide, due to the huge biotechnological potential of these photosynthetic microorganisms. However, production of these microorganisms is still not economically viable. One possible alternative to improve the economic feasibility of the process is the use of consortia between microalgae and/or cyanobacteria. In this study, Chlorella vulgaris, Pseudokirchneriella subcapitata and Microcystis aeruginosa were co-cultivated with Synechocystis salina to evaluate how dual-species cultures can influence biomass and lipid production and nutrients removal. Results have shown that the three studied consortia achieved higher biomass productivities than the individual cultures. Additionally, nitrogen and phosphorus consumption rates by the consortia provided final concentrations below the values established by European Union legislation for these nutrients. In the case of lipid productivities, higher values were determined when S. salina was co-cultivated with P. subcapitata and M. aeruginosa. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. The Salinas formation in the type-area, Northeastern Minas Gerais: a proposal to review the stratigraphy of the Aracuai belt on sedimentary, metamorphic and U-Pb SHRIMP evidences

    International Nuclear Information System (INIS)

    Lima, Sirlene A. de Abreu; Pedrosa Soares, Antonio C.; Cordani, Umberto G.; Nutman, Allen

    2002-01-01

    The Salinas Formation has been considered to be a stratigraphic unit of the Macaubas Group. This group comprises the rift to passive margin sequences of the precursor basin of the Neo proterozoic Aracuai Orogeny, eastern Brazil. However, new road cuts show extensive and spectacular outcrops with very well-preserved sedimentary structures, allowing detailed studies in the type-locality of this formation, located in the Salinas town and surroundings, northeast Minas Gerais State. In its type-locality, the Salinas Formation consists of graywacke, pelite and clast-supported conglomerate, metamorphosed in the green schist facies. The sedimentary lithofacies are grouped into three facies association (shelf, slope and deep-sea), indicating sedimentation from shelf deposits to deep-water turbidites. The shelf sedimentation was influenced by storm-wave during deposition. The slump and deep-sea deposits were generated by gravitational flows and high- to low-concentration turbidity currents. Shelf sandstone, clast-supported conglomerate and proximal to distal turbidites outline a submarine fan system. U-Pb SHRIMP data from detrital zircons of graywacke samples indicate a maximum sedimentation age of ca. 568 Ma. Thus, the Salinas Formation is much younger than the Macaubas Group, and represents late orogenic deposits (ca. 568- 500 Ma). The distal, passive margin unit of the Macaubas Group is now called Ribeirao da Folha Formation (ca. 800 Ma). (author)

  2. Analysis of impact of temperature and saltwater on Nannochloropsis salina bio-oil production by ultra high resolution APCI FT-ICR MS

    KAUST Repository

    Sanguineti, Michael Mario; Hourani, Nadim; Witt, Matthí as; Sarathy, Mani; Thomsen, Laurenz A.; Kuhnert, Nikolai

    2015-01-01

    Concentrated Nannochloropsis salina paste was reconstituted in distilled water and synthetic saltwater and processed at 250°C and 300°C via hydrothermal liquefaction. The resulting bio-oils yielded a diverse distribution of product classes

  3. Desenvolvimento de mudas de pinhão-manso irrigadas com água salina

    Directory of Open Access Journals (Sweden)

    Fábio Santos Matos

    2013-08-01

    Full Text Available O uso de água salina na irrigação torna-se importante alternativa diante daescassez de água de boa qualidade em todo o mundo. O pinhão-manso (Jatropha curcas L. possui baixa exigência hídrica, sobrevive e apresenta produção satisfatória em solos de baixa fertilidade. No entanto, a sua produção é maior em cultivos irrigados, o que reforça a necessidade de desenvolvimento de pesquisas para uso de água salina. Este trabalho objetivou avaliar o efeito de diferentes níveis de salinidade da água de irrigação nas características morfofisiológicas de mudas de pinhão-manso. Para isso, foi conduzido experimento em casa de vegetação com interceptação de 50 % da radiação solar, localizada na Universidade Estadual de Goiás, Ipameri, Goiás. O experimento foi conduzido em vasos com capacidade de 4 L de solo, utilizando-se o delineamento inteiramente casualizado, com quatro tratamentos e cinco repetições. As plantas foram irrigadas diariamente com 150 mL de água não salina, durante os 30 primeiros dias após a germinação das sementes. Do 31º ao 50º dia, as plantas foram submetidas a quatro tratamentos: plantas diariamente irrigadas com água de condutividade elétrica igual a 0,5; 8; 16 e 24 dS m-1. Aos 50 dias após a germinação, analisaram-se as seguintes características nas mudas de pinhão-manso: número de folhas; altura de planta; diâmetro de ramo; teor relativo de água; área foliar; clorofila total; razões de massa radicular, massa caulinar, massa foliar e parte aérea/sistema radicular; e biomassa total. Os resultados evidenciaram que as mudas de pinhão-manso irrigadas com água de condutividade elétrica 8 dS m-1 não apresentaram redução do crescimento vegetativo. Todavia, a água de irrigação com condutividade elétrica 16 dS m-1 causou redução no crescimento vegetativo e elevou a senescência e abscisão foliar. Água com condutividade elétrica elétrica de pinhão-manso na fase de mudas.

  4. Prospecção fitoquímica de Sonchus oleraceus e sua toxicidade sobre o microcrustáceo Artemia salina Phytochemical prospecting of Sonchus oleraceus and its toxicity to Artemia salina

    OpenAIRE

    J.M. Lima; C.A. Silva; M.B. Rosa; J.B. Santos; T.G. Oliveira; M.B. Silva

    2009-01-01

    A espécie vegetal Sonchus oleraceus é uma planta daninha presente em diversas culturas no Brasil e de utilização na medicina popular. Neste trabalho, realizou-se a prospecção fitoquímica dessa espécie com extratos em etanol, água e diclorometano, bem como testes de toxicidade sobre o microcrustáceo Artemia salina. O extrato aquoso apresentou em sua composição açúcares redutores, compostos fenólicos, taninos, flavonóides e cumarinas. No extrato etanólico, observaram-se os mesmos compostos qual...

  5. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    OpenAIRE

    Mayorga,Pablo; Pérez,Karen R.; Cruz,Sully M.; Cáceres,Armando

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  6. Assembly of the Lactuca sativa, L. cv. Tizian draft genome sequence reveals differences within major resistance complex 1 as compared to the cv. Salinas reference genome.

    Science.gov (United States)

    Verwaaijen, Bart; Wibberg, Daniel; Nelkner, Johanna; Gordin, Miriam; Rupp, Oliver; Winkler, Anika; Bremges, Andreas; Blom, Jochen; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2018-02-10

    Lettuce (Lactuca sativa, L.) is an important annual plant of the family Asteraceae (Compositae). The commercial lettuce cultivar Tizian has been used in various scientific studies investigating the interaction of the plant with phytopathogens or biological control agents. Here, we present the de novo draft genome sequencing and gene prediction for this specific cultivar derived from transcriptome sequence data. The assembled scaffolds amount to a size of 2.22 Gb. Based on RNAseq data, 31,112 transcript isoforms were identified. Functional predictions for these transcripts were determined within the GenDBE annotation platform. Comparison with the cv. Salinas reference genome revealed a high degree of sequence similarity on genome and transcriptome levels, with an average amino acid identity of 99%. Furthermore, it was observed that two large regions are either missing or are highly divergent within the cv. Tizian genome compared to cv. Salinas. One of these regions covers the major resistance complex 1 region of cv. Salinas. The cv. Tizian draft genome sequence provides a valuable resource for future functional and transcriptome analyses focused on this lettuce cultivar. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Executive summary of a draft report on the geology and salt deposits of the Salina Salt Basin

    International Nuclear Information System (INIS)

    1978-01-01

    The study discussed is the first phase of a program for the geologic evaluation of the Silurian-age bedded salt of the Salina Group. The Salina Salt Basin, as used in this study, includes those portions of the Appalachian and Michigan basins that are underlain by the Salina Group. The full draft report consists of a regional reconnaissance, identification of study areas in New York and Ohio which are deserving of a more thorough evaluation, and a program plan to accomplish that evaluation. The entire draft report is in two volumes, contains 1068 pages and 204 figures, and has a bibliography that consists of over 1100 separate entries. This summary has been prepared for the benefit of those who wish to review the results of this phase of the evaluation but who do not want to go through the exhaustive detail that is present in the full report. The regional reconnaissance was accomplished by a very thorough and extensive literature review, addressing the following topics: depth of salt, thickness, stratigraphy, tectonics, structure, seismicity, hydrology, erosion and denudation, and mineral resources. Before further technical evaluation proceeds, the draft report and the proposed program are being subjected to a thorough evaluation by a number of groups, including appropriate state agencies. This rather extensive review process is being conducted to ensure that the program is performed entirely in the open and subject to continuous public surveillance. This report does not represent the first work that has been done in this region with regard to evaluating the salt deposits for waste disposal. Previous efforts have been limited, however, and have been done by individual consultants. At the present time, the U.S. Geological Survey is also participating in the technical evaluation; their results will be issued separately. In addition to the technical evaluations, environmental surveys will also be conducted as an integral part of this thorough evaluation program

  8. Preliminary Data on the Safety of Phytoene- and Phytofluene-Rich Products for Human Use including Topical Application

    Directory of Open Access Journals (Sweden)

    Fabien Havas

    2018-01-01

    Full Text Available The colorless carotenoids phytoene and phytofluene are comparatively understudied compounds found in common foods (e.g., tomatoes and in human plasma, internal tissues, and skin. Being naturally present in common foods, their intake at dietary levels is not expected to present a safety concern. However, since the interest in these compounds in the context of many applications is expanding, it is important to conduct studies aimed at assessing their safety. We present here results of in vitro cytotoxicity and genotoxicity studies, revealing no significant cytotoxic or genotoxic potential and of short- and long-term human in vivo skin compatibility studies with phytoene- and phytofluene-rich tomato and Dunaliella salina alga extracts, showing a lack of irritancy or sensitization reactions. These results support the safe use of phytoene- and phytofluene-rich products in human topical applications.

  9. Salt-stimulation of caesium accumulation in the euryhaline green microalga Chlorella salina: potential relevance to the development of a biological Cs-removal process

    Energy Technology Data Exchange (ETDEWEB)

    Avery, S. V.; Codd, G. A.; Gadd, G. M. [Department of Biological Sciences, University of Dundee, Dundee DD1 4HN (United Kingdom)

    1993-07-01

    Accumulation of Cs{sup +} by Chlorella salina was 28-fold greater in cells incubated in the presence than in the absence of 0.5 M-NaCl. An approximate 70% removal of external Cs{sup +} resulted after 15 h incubation of cells with 50 μ;M-CsCl and 0.5 M-NaCl. LiCl also had a stimulatory effect on Cs{sup +} uptake, although mannitol did not. Cs{sup +} influx increased with increasing external NaCl concentration and was maximal between 25-500 mM-NaCl at approximately 4 nmol Cs{sup +} h−1 (10{sup 6} cells){sup −1}. Little effect on Cs{sup +} uptake resulted from the presence of Mg{sup 2+} or Ca{sup 2+} or from varying the external pH, and Cs{sup +} was relatively non-toxic towards C. salina. At increasing cell densities (from 4 × 10{sup 5} to 1 × 10{sup 7} cells ml{sup +1}), decreasing amounts of Cs{sup +} were accumulated per cell although the rate of Cs{sup +} removal from the external medium was still greatest at the higher cell densities examined. Freely suspended C. salina and cell-loaded alginate microbeads accumulated similar levels of Cs{sup +}, however, 46% of total Cs{sup +} uptake was attributable to the calcium-alginate matrix in the latter case. When Cs{sup +}-loaded cells were subjected to hypoosmotic shock, loss of cellular Cs{sup +} occurred allowing easy Cs{sup +} recovery. This loss exceeded 90% of cellular Cs{sup +} when cells were washed with solutions containing ≤ 50 mM-NaCl between consecutive Cs{sup +} uptake periods; these cells subsequently lost their ability to accumulate large amounts of Cs{sup +}. Maximal Cs{sup +} uptake (approximately 85.1% removal after three 15 h incubations) occurred when cells were washed with a solution containing 500 mM-NaCl and 200 mM-KCl between incubations. The relevance of these results to the possible use of C. salina in a salt-dependent biological Cs-removal process is discussed. (author)

  10. Effects of salinity, commercial salts, and water type on cultivation of the cryptophyte microalgae Rhodomonas salina and the calanoid Copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Thoisen, Christina V.; Carron-Cabaret, Thibaut

    2018-01-01

    Marine aquaculture facilities positioned far from the sea need access to seawater (SW); hence, commercial salts are often the chosen solution. In marine hatcheries, most fish larvae require live feed (zooplankton) that are in turn fed with microalgae. The objective of this research was to investi......Marine aquaculture facilities positioned far from the sea need access to seawater (SW); hence, commercial salts are often the chosen solution. In marine hatcheries, most fish larvae require live feed (zooplankton) that are in turn fed with microalgae. The objective of this research...... was to investigate the applicability of commercial salts and clarify the potential effects on the cultivation of the microalga Rhodomonas salina and the copepod Acartia tonsa. Three commercial salts were tested, Red Sea Salt (RS), Red Sea – Coral Pro Salt (CP), and Blue Treasure Salt. R. salina was cultured...

  11. National Uranium Resource Evaluation: Salina Quadrangle, Utah

    International Nuclear Information System (INIS)

    Lupe, R.D.; Campbell, J.A.; Franczyk, K.J.; Luft, S.J.; Peterson, F.; Robinson, K.

    1982-09-01

    Two stratigraphic units, the Late Jurassic Salt Wash Member of the Morrison Formation and the Triassic Chinle Formation, were determined to be favorable for the occurrence of uranium deposits that meet the minimum size and grade requirements of the US Department of Energy in the Salina 1 x 2 0 Quadrangle, Utah. Three areas judged favorable for the Salt Wash Member are the Tidwell and Notom districts, and the Henry Mountains mineral belt. The criteria used to establish favorability were the presence of: (1) fluvial sandstone beds deposited by low-energy streams; (2) actively moving major and minor structures such as the Paradox basin and the many folds within it; (3) paleostream transport directions approximately perpendicular to the trend of many of the paleofolds; (4) presence of favorable gray lacustrine mudstone beds; and (5) known uranium occurrences associated with the favorable gray mudstones. Four favorable areas have been outlined for the Chinle Formation. These are the San Rafael Swell, Inter River, and the Orange Cliffs subareas and the Capitol Reef area. The criteria used to establish these areas are: the sandstone-to-mudstone ratios and the geographic distribution of the Petrified Forest Member of the Chinle Formation which is considered as the probable source for the uranium

  12. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    OpenAIRE

    Pablo Mayorga; Karen R. Pérez; Sully M. Cruz; Armando Cáceres

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  13. Complete genome sequence of Mahella australiensis type strain (50-1 BONT)

    Energy Technology Data Exchange (ETDEWEB)

    Sikorski, Johannes [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Ngatchou, Olivier Duplex [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Pukall, Rudiger [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute

    2011-01-01

    Mahella australiensis Bonilla Salinas et al. 2004 is the type species of the genus Mahella, which belongs to the family Thermoanaerobacteraceae. The species is of interest because it differs from other known anaerobic spore-forming bacteria in its G+C content, and in certain phenotypic traits, such as carbon source utilization and relationship to temperature. Moreo- ver, it has been discussed that this species might be an indigenous member of petroleum and oil reservoirs. This is the first completed genome sequence of a member of the genus Mahella and the ninth completed type strain genome sequence from the family Thermoanaerobacte- raceae. The 3,135,972 bp long genome with its 2,974 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  14. 78 FR 37790 - In the Matter of: Mario Salinas-Lucio, Inmate Number #61687-279, FCI La Tuna, Federal Corrections...

    Science.gov (United States)

    2013-06-24

    ... DEPARTMENT OF COMMERCE Bureau of Industry and Security In the Matter of: Mario Salinas-Lucio... Order with the Under Secretary of Commerce for Industry and Security. The appeal must be filed within 45....S.C. 793, 794 or 798; section 4(b) of the Internal Security Act of 1950 (50 U.S.C. 783(b)), or...

  15. Gyrodactylus salinae n. sp. (Platyhelminthes: Monogenea infecting the south European toothcarp Aphanius fasciatus (Valenciennes (Teleostei, Cyprinodontidae from a hypersaline environment in Italy

    Directory of Open Access Journals (Sweden)

    Huyse Tine

    2011-06-01

    Full Text Available Abstract Background Historically, non-native species of Gambusia (Poeciliidae have been used to control larval stages of the Asian tiger mosquito, Stegomyia albopicta Reinert, Harbach et Kitching, 2004 throughout Italy. The potential utility of indigenous populations of Aphanius fasciatus (Valenciennes (Teleostei: Cyprinodontidae as an appropriate alternative biological control is currently being explored. A sub-sample of ten fish collected from Cervia Saline, Italy (salinity 65 ppt; 30°C to assess their reproductive capability in captivity, harboured a moderate infection of Gyrodactylus von Nordmann, 1832 (Platyhelminthes, Monogenea. A subsequent morphological and molecular study identified this as being a new species. Results Gyrodactylus salinae n. sp. is described from the skin, fins and gills of A. fasciatus. Light and scanning electron microscopical (SEM examination of the opisthaptoral armature and their comparison with all other recorded species suggested morphological similarities to Gyrodactylus rugiensoides Huyse et Volckaert, 2002 from Pomatoschistus minutus (Pallas. Features of the ventral bar, however, permit its discrimination from G. rugiensoides. Sequencing of the nuclear ribosomal DNA internal transcribed spacers 1 and 2 and the 5.8S rRNA gene and a comparison with all species listed in GenBank confirmed they are unique and represent a new species (most similar to Gyrodactylus anguillae Ergens, 1960, 8.3% pair-wise distance based on 5.8S+ITS2. This represents the first species of Gyrodactylus to be described from Aphanius and, to date, has the longest ITS1 (774 bp sequenced from any Gyrodactylus. Additional sampling of Cervia Saline throughout the year, found G. salinae n. sp. to persist in conditions ranging from 35 ppt and 5°C in December to 65 ppt and 30°C in July, while in captivity a low level of infection was present, even in freshwater conditions (0 ppt. Conclusions The ability of G. salinae n. sp. to tolerate a wide

  16. Novel 9-cis/all-trans β-carotene isomerases from plastidic oil bodies in Dunaliella bardawil catalyze the conversion of all-trans to 9-cis β-carotene.

    Science.gov (United States)

    Davidi, Lital; Pick, Uri

    2017-06-01

    We identified and demonstrated the function of 9-cis/all-trans β-carotene isomerases in plastidic globules of Dunaliella bardawil, the species accumulating the highest levels of 9-cis β-carotene that is essential for humans. The halotolerant alga Dunaliella bardawil is unique in that it accumulates under light stress high levels of β-carotene in plastidic lipid globules. The pigment is composed of two major isomers: all-trans β-carotene, the common natural form of this pigment, and 9-cis β-carotene. The biosynthetic pathway of β-carotene is known, but it is not clear how the 9-cis isomer is formed. We identified in plastidic lipid globules that were isolated from D. bardawil two proteins with high sequence homology to the D27 protein-a 9-cis/all-trans β-carotene isomerase from rice (Alder et al. Science 335:1348-1351, 2012). The proteins are enriched in the oil globules by 6- to 17-fold compared to chloroplast proteins. The expression of the corresponding genes, 9-cis-βC-iso1 and 9-cis-βC-iso2, is enhanced under light stress. The synthetic proteins catalyze in vitro conversion of all-trans to 9-cis β-carotene. Expression of the 9-cis-βC-iso1 or of 9-cis-βC-iso2 genes in an E. coli mutant line that harbors β-carotene biosynthesis genes enhanced the conversion of all-trans into 9-cis β-carotene. These results suggest that 9-cis-βC-ISO1 and 9-cis-βC-ISO2 proteins are responsible for the formation of 9-cis β-carotene in D. bardawil under stress conditions.

  17. Approaches about prescriptions and corporal practices in schools in Pirapora, Januária and Salinas (1906-1927

    Directory of Open Access Journals (Sweden)

    ELISÂNGELA CHAVES

    2012-01-01

    Full Text Available The text analyses the proposal of the corporal education in schools in the north of Minas Gerais during 1906 and 1927, especially in Pirapora, januária and Salinas. As main source, the research made use of oral reports and other documents directly related to school memory to understand how physical activities were realized as habit and attitude-forming, in a historic moment in which Brazil used to cherish the modernizing speech.

  18. Biotechnological production of value-added carotenoids from microalgae: Emerging technology and prospects.

    Science.gov (United States)

    Wichuk, Kristine; Brynjólfsson, Sigurður; Fu, Weiqi

    2014-01-01

    We recently evaluated the relationship between abiotic environmental stresses and lutein biosynthesis in the green microalga Dunaliella salina and suggested a rational design of stress-driven adaptive evolution experiments for carotenoids production in microalgae. Here, we summarize our recent findings regarding the biotechnological production of carotenoids from microalgae and outline emerging technology in this field. Carotenoid metabolic pathways are characterized in several representative algal species as they pave the way for biotechnology development. The adaptive evolution strategy is highlighted in connection with enhanced growth rate and carotenoid metabolism. In addition, available genetic modification tools are described, with emphasis on model species. A brief discussion on the role of lights as limiting factors in carotenoid production in microalgae is also included. Overall, our analysis suggests that light-driven metabolism and the photosynthetic efficiency of microalgae in photobioreactors are the main bottlenecks in enhancing biotechnological potential of carotenoid production from microalgae.

  19. Continuous background light significantly increases flashing-light enhancement of photosynthesis and growth of microalgae.

    Science.gov (United States)

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2015-01-01

    Under specific conditions, flashing light enhances the photosynthesis rate in comparison to continuous illumination. Here we show that a combination of flashing light and continuous background light with the same integrated photon dose as continuous or flashing light alone can be used to significantly enhance photosynthesis and increase microalgae growth. To test this hypothesis, the green microalga Dunaliella salina was exposed to three different light regimes: continuous light, flashing light, and concomitant application of both. Algal growth was compared under three different integrated light quantities; low, intermediate, and moderately high. Under the combined light regime, there was a substantial increase in all algal growth parameters, with an enhanced photosynthesis rate, within 3days. Our strategy demonstrates a hitherto undescribed significant increase in photosynthesis and algal growth rates, which is beyond the increase by flashing light alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Composição química e toxicidade frente Aedes aegypti L. e Artemia salina Leach do óleo essencial das folhas de Myrcia sylvatica (G. Mey. DC.

    Directory of Open Access Journals (Sweden)

    C.S. ROSA

    2016-03-01

    Full Text Available RESUMO A dengue está entre as doenças virais de propagação vetorial mais importante no mundo, causando sérios impactos de morbidade e mortalidade. Desta forma, o presente trabalho teve como objetivo analisar a composição química e a toxicidade do óleo essencial de Myrcia sylvatica (G. Mey D.C. frente Aedes aegypti e Artemia salina. Folhas de M. sylvatica foram coletadas no Parque Nacional da Chapada das Mesas, no município de Carolina (MA no mês de fevereiro de 2012. O óleo foi obtido por hidrodestilação e sua composição química foi determinada por cromatografia gasosa acoplada à espectrometria de massa (CG/EM. O bioensaio frente Artemia salina e às larvas de 3° estádio de Aedes aegypti foram realizados em diferentes concentrações. Os dados de mortalidade foram avaliados por regressão linear para determinar os valores de CL50. Obteve-se 0,5% de rendimento, sendo o (E-cariofileno o constituinte majoritário. O óleo essencial apresentou uma CL50 = 79,44 µg/mL frente A. salina, sendo considerado altamente tóxico. No entanto, este óleo não demonstrou efeito sobre as larvas de A. aegypti. Considerando que o teste de Artemia salina tem correlação com atividades biológicas de grande interesse terapêutico como antitumoral, o óleo essencial das folhas de M. sylvatica demonstrou potencial para desenvolvimento de produtos farmacêuticos.

  1. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    Directory of Open Access Journals (Sweden)

    Pablo Mayorga

    2010-12-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.Três bioensaios de letalidade com o crustáceo de água salgada Artemia salina Leach, Artemiidae, (teste convencional em microplaca de 96 poós Artoxkit microbiotest M e o crustáceo de água doce Thamnocephalus platyurus Packard, Thamnocephalidae (Thamnotoxkit microbiotest F, foram comparados utilizando extratos de dez espécies de plantas da Guatemala. Foi previamente observado que cinco delas possuem atividade anti

  2. Depositional environment, sand provenance, and diagenesis of the Basal Salina Formation (lower Eocene), northwestern Peru

    Science.gov (United States)

    Marsaglia, K. M.; Carozzi, A. V.

    The Basal Salina Formation is a lower Eocene transgressive sequence consisting of interbedded shales, siltstones, and conglomeratic sandstones. This formation occurs in the Talara basin of northwestern Peru and is one of a series of complexly faulted hydrocarbon-producing formations within this extensional forearc basin. These sediments were probably deposited in a fan-delta complex that developed along the ancestral Amotape Mountains during the early Eocene. Most of the sediment was derived from the low-grade metamorphic and plutonic rocks that comprise the Amotape Mountains, and their sedimentary cover. Detrital modes of these sandstones reflect the complex tectonic history of the area, rather than the overall forearc setting. Unlike most forearc sediments, these are highly quartzose, with only minor percentages of volcanic detritus. This sand is variably indurated and cemented by chlorite, quartz, calcite, and kaolinite. Clay-mineral matrix assemblages show gradational changes with depth, from primarily detrital kaolinite to diagenetic chlorite and mixed-layered illite/smectite. Basal Salina sandstones exhibit a paragenetic sequence that may be tied to early meteoric influx or late-stage influx of thermally driven brines associated with hydrocarbon migration. Much of the porosity is secondary, resulting from a first-stage dissolution of silicic constituents (volcanic lithic fragments, feldspar, and fibrous quartz) and a later dissolution of surrounding carbonate cement. Types of pores include skeletal grains, grain molds, elongate pores, and fracture porosity. Measured porosity values range up to 24% and coarser samples tend to be more porous. Permeability is enhanced by fractures and deterred by clay-mineral cements and alteration residues.

  3. Bioatividade de três espécies vegetais nativas da Floresta Atlântica brasileira frente ao microcrustáceo Artemia salina

    Directory of Open Access Journals (Sweden)

    W.M Pompilho

    2014-09-01

    Full Text Available Este trabalho teve por objetivo a investigação fitoquímica e propriedades antioxidantes de extratos das folhas de Trigynaea oblongifolia Schltdl (Annonaceae, Ottonia frutescens Trel (Piperaceae, e Bathysa australis (St Hill Hooz (Rubiaceae, bem como avaliar, in vitro, a letalidade frente ao microcrustáceo Artemia salina Leach. Os extratos foram preparados por maceração em metanol 10% (p/v por sete dias, à temperatura ambiente. A atividade antioxidante dos extratos foi determinada pela metodologia que utiliza o radical estável DPPH. A toxicidade dos extratos foi avaliada frente ao microcrustáceo A. salina. Os extratos de O. frutescens e B. australis apresentaram as seguintes classes de metabólitos secundários: Alcalóides, Antraquinonas, Cumarinas, Polifenóis (Taninos, Saponinas. Nos extratos de T. oblongifolia, além dos metabólitos citados anteriormente, foi detectada a presença de Flavonóides. A atividade antioxidante, observada em 30 minutos na concentração de 24 µg/mL de extrato, foi de: O. frutescens - 38,3%, T. oblongifolia - 32,3%, e B. australis - 32,1%. A Concentração Letal, CL50, dos extratos em A. salina foi de: O. frutescens - 149,75 ± 1,02 µg/mL, T. oblongifolia - 148,8 ± 1,74 µg/mL, e B. australis - 684 ± 9,04 µg/mL. Neste contexto, destacamos as espécies, nativas da Floresta Atlântica, O. frutescens e T. oblongifolia de grande potencial na bioprospecção de moléculas biologicamente ativas.

  4. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    Directory of Open Access Journals (Sweden)

    Pablo Mayorga

    2010-10-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.

  5. Avaliação da bioatividade dos extratos de cúrcuma (Curcuma longa L., Zingiberaceae em Artemia salina e Biomphalaria glabrata

    Directory of Open Access Journals (Sweden)

    Carlos R. M. da Silva Filho

    Full Text Available A cúrcuma é o rizoma limpo, em boas condições, seco e moído da Curcuma longa L., uma planta herbácea da família Zingiberaceae. Visando novas alternativas para o controle da esquistossomose, os extratos de Curcuma longa L. foram testados para a avaliação da atividade moluscicida contra caramujos adultos da espécie Biomphalaria glabrata, e toxicidade (ensaio de letalidade com Artemia salina. A oleoresina e o óleo essencial de cúrcuma foram ativos contra Artemia salina (CL50 = 80,43 e CL50 = 319,82 μg/mL, respectivamente e também ativos contra os indivíduos adultos de Biomphalaria glabrata (CL50 = 58,3 e CL50 = 46,73 μg/mL, respectivamente. A partir dos resultados obtidos pôde ser concluído que ambos os extratos podem constituir uma alternativa no controle da população desses caramujos e na redução da esquistossomose.

  6. Abelhas (Hymenoptera: apoidea visitantes das flores de goiaba em pomar comercial in Salinas, MG Bee diversity in a commercial guava orchard in Salinas, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Rosemeire Alves Guimarães

    2009-01-01

    Full Text Available As abelhas são responsáveis por cerca de 80% a 100% da polinização de culturas agrícolas, especialmente aquelas relacionadas com a produção de sementes e frutos. A investigação da diversidade de abelhas em pomares de goiaba pode ser subsídio para estratégias de incremento da produtividade. Nesta perspectiva, o objetivo deste estudo foi identificar a diversidade de abelhas visitantes das flores de goiaba (Psidium guajava, em pomar comercial em Salinas (MG. O trabalho foi desenvolvido em maio de 2005 e foram coletadas as abelhas visitantes das flores nos horários entre 6h e 18h, totalizando-se 44 horas de coleta. Coletaram-se 705 abelhas de 17 espécies, sendo Trigona spinipes a mais freqüente e dominante na cultura da goiaba. Apis mellifera, Melipona quadrifasciata e Tetragonisca angustula foram consideradas acessórias. Aproximadamente 84% dos indivíduos foram coletados da manhã, de 6h às 10h.Pollination is an important factor in agricultural systems, especially in growing fruits and seed production, which depend greatly on bee visiting during blossom season; highly successful gains within these activities varies between 80 and nearly 100 per cent, owing to the bees. The assessment of bee diversity in commercial orchards of guava may contribute to a more desirable strategic design and consequent improvement of production. The aim of the study was identify the diversity of visiting bees to guava flowers (Psidium guajava in a commercial orchard in Salinas, State of Minas Gerais, Brazil. The work was carried during blossom season of May - 2005. Field works occurred between 6:00 am to 6:00 pm, counting with 44 hours of collection, when 705 bees were collected. The richness observed was of 17 species, the most frequent and dominant being Trigona spinipes. Among the collection there were some considered accessory species: Apis mellifera, Melipona quadrifasciata and Tetragonisca angustula. Most of individual bees have been captured

  7. The efficiency of a new hydrodynamic cavitation pilot system on Artemia salina cysts and natural population of copepods and bacteria under controlled mesocosm conditions.

    Science.gov (United States)

    Cvetković, Martina; Grego, Mateja; Turk, Valentina

    2016-04-15

    A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Effect of Dunaliella tertiolecta organic exudates on the Fe(II) oxidation kinetics in seawater.

    Science.gov (United States)

    González, A G; Santana-Casiano, J M; González-Dávila, M; Pérez-Almeida, N; Suárez de Tangil, M

    2014-07-15

    The role played by the natural organic ligands excreted by the green algae Dunaliella tertiolecta on the Fe(II) oxidation rate constants was studied at different stages of growth. The concentration of dissolved organic carbon increased from 2.1 to 7.1 mg L(-1) over time of culture. The oxidation kinetics of Fe(II) was studied at nanomolar levels and under different physicochemical conditions of pH (7.2-8.2), temperature (5-35 °C), salinity (10-37), and dissolved organic carbon produced by cells (2.1-7.1 mg L(-1)). The experimental rate always decreased in the presence of organic exudates with respect to that in the control seawater. The Fe(II) oxidation rate constant was also studied in the context of Marcus theory, where ΔG° was 39.31-51.48 kJ mol(-1). A kinetic modeling approach was applied for computing the equilibrium and rate constants for Fe(II) and exudates present in solution, the Fe(II) speciation, and the contribution of each Fe(II) species to the overall oxidation rate constant. The best fit model took into account two acidity equilibrium constants for the Fe(II) complexing ligands with pKa,1=9.45 and pKa,2=4.9. The Fe(II) complexing constants were KFe(II)-LH=3×10(10) and KFe(II)-L=10(7), and the corresponding computed oxidation rates were 68±2 and 36±8 M(-1) min(-1), respectively.

  9. Aplicación del bioensayo de Artemia salina en el análisis general de plantas medicinales brasileñas

    OpenAIRE

    Montanher, Ana Beatriz Pimentel; Pizzolatti, Moacir Geraldo; Brighente, Inês Maria Costa

    2002-01-01

    Extractos de once especies de la flora brasileña fueron estudiados para evaluar la actividad citotóxica por el test de Artemia salina. Las plantas seleccionadas fueron: Baccharis pseudotenuifolia, Baccharis ligustrina, Baccharis platypoda, Baccharis coridifolia, Polygala paniculata, Polygala sabulosa, Croton celtidifolius, Cyathea phalerata, Trichilia catigua, Eugenia uniflora y Schinus molle. Los resultados obtenidos para los extractos crudos de B. pseudotenuifolia, B. ligustrina, B. c...

  10. Biokinetic model-based multi-objective optimization of Dunaliella tertiolecta cultivation using elitist non-dominated sorting genetic algorithm with inheritance.

    Science.gov (United States)

    Sinha, Snehal K; Kumar, Mithilesh; Guria, Chandan; Kumar, Anup; Banerjee, Chiranjib

    2017-10-01

    Algal model based multi-objective optimization using elitist non-dominated sorting genetic algorithm with inheritance was carried out for batch cultivation of Dunaliella tertiolecta using NPK-fertilizer. Optimization problems involving two- and three-objective functions were solved simultaneously. The objective functions are: maximization of algae-biomass and lipid productivity with minimization of cultivation time and cost. Time variant light intensity and temperature including NPK-fertilizer, NaCl and NaHCO 3 loadings are the important decision variables. Algal model involving Monod/Andrews adsorption kinetics and Droop model with internal nutrient cell quota was used for optimization studies. Sets of non-dominated (equally good) Pareto optimal solutions were obtained for the problems studied. It was observed that time variant optimal light intensity and temperature trajectories, including optimum NPK fertilizer, NaCl and NaHCO 3 concentration has significant influence to improve biomass and lipid productivity under minimum cultivation time and cost. Proposed optimization studies may be helpful to implement the control strategy in scale-up operation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Preliminary results of the Artemia salina experiments in biostack on LDEF

    International Nuclear Information System (INIS)

    Graul, E.H.; Ruether, W.; Hiendl, C.O.

    1992-01-01

    The mosaic egg of the brine shrimp, Artemia salina, resting in blastula or gastrula state represents a system that during further development, proceeds without any further development to the larval stage, the free swimming nauplius. Therefore, injury to a single cell of the egg will be manifest in the larvae. In several experiments, it was shown that the passage of a single heavy ion through the shrimp egg damaged a cellular area large enough to disturb either embryogenesis or further development of the larvae, or the integrity of the adult individual. Emergence from the egg shell was heavily disturbed by the heavy ions as was hatching. Additional late effects, due to a hit by a heavy ion, are delayed of growth and of sexual maturity, and reduced fertility. Anomalies in the body and the extremities could be observed more frequently for the nauplii which had developed from eggs hit by heavy ions

  12. La sedimentación salina actual en las lagunas de La Mancha: una síntesis.

    OpenAIRE

    Peña Zarzuelo, Antonio de la; Marfil, R.

    1986-01-01

    [ES] La Mancha es una región natural de más de 30.000 Km2, caracterizada por una topografía extraordinariamente plana y un clima de tipo semiárido (Cuadro 1, Fig. 2), en la que existen numerosas lagunas salinas (Fig. 1), la mayoría de las cuales, por su régimen anual, pueden ser consideradas como «playa-lakes» (Fig. 3). Desde el punto de vista hidroquimico sus salmueras están integradas por: a) aniones: SO4 y Cl, con CO3 y CO 3H subordinados, y b) cationes: Mg 2+ y ...

  13. Evaluation of the bioactivities of some Myanmar medicinal plants using brine shrimp (Artemia salina) toxicity test

    International Nuclear Information System (INIS)

    Sabai; Khin Khin Win Aung; Nwe Ni Thin; Kyi Shwe; Tin Myint Htwe

    2001-01-01

    For a variety of toxic substances, brine shrimp larvae (Artemia salina) are usually used as a simple bioassay method and it is also applied for natural product research. The brine shrimp larvae (nauplii) are obtained by natural hatching method from Artemia cysts. By using the larvae, the results from these experiments lead to the lethal dose, LD 50 values of extracts of selected medicinal plants. Activities of a broad range of plant extracts are manifested as toxicity to the brine shrimp. Screening results with six plant extracts are compared with pure caffeine. This method is rapid, reliable, inexpensive and convenient. (author)

  14. Storage conditions affect oxidative stability and nutritional composition of freeze-dried Nannochloropsis salina

    DEFF Research Database (Denmark)

    Safafar, Hamed; Langvad, Sten; Møller, Peter

    2017-01-01

    composition of microalgae biomass. In order to investigate the worsening of the nutritional quality of freeze dried biomass, a multifactorial storage experiment was conducted on a high EPA (eicosapentaenoic acid) Nannochloropsis salina biomass. The storage time (0–56 days), storage temperature (5, 20,and 40...... °C and packaging conditions (under vacuum and ambient pressure)used as main factors. During the 56 days of storage, both time and temperature strongly influenced the oxidation reactions which result in deterioration of bioactive compounds such as carotenoids, tocopherols, and EPA. Lipid deterioration......, or cosmetics requires the knowledge of the optimum storage conditions to prevent the value-added compounds from deterioration. Results of this study improve our understanding of the chemical deterioration under different storage conditions and can help the producers/customers to extend the shelf life...

  15. Spatial scale and the diversity of benthic cyanobacteria and diatoms in a salina

    DEFF Research Database (Denmark)

    Nübel, U.; Garcia-Pichel, F.; Kühl, Michael

    1999-01-01

    We characterized the richness of benthic cyanobacteria and diatoms in a salina system using traditional and molecular biological methods. After determining the different morphotypes and 16S rRNA genes present in various localities within this hypersaline system, an analysis of the increase......, and for the estimation of the average degree of dissemination of community members within the system. We found interesting differences between analyses based on morphotypes or 16S rRNA genes. The cumulative number of rRNA gene sequences exceeded that of morphotypes by more than two-fold. This indicates that many...... organisms possessing distinct 16S rRNA gene sequences could not be distinguished on the basis of morphology. Thus, some of the apparently widely distributed morphotypes may in fact conceal several ecologically independent genotypes....

  16. Cultural heritage and food identity: The pre-Hispanic salt of Zapotitlán Salinas, Mexico

    Directory of Open Access Journals (Sweden)

    Renard, Marie-Christine

    2016-06-01

    Full Text Available Salt production in Zapotitlán de las Salinas (Puebla, Mexico dates back to pre-Hispanic times when the Popolocas inhabiting the Tehuacán Valley paid it as tribute to the Aztecs. The technique to obtain salt has changed little over the past 500 years and know-how continues to be transmitted from generation to generation of salters (salineros. It is a resource that is deeply anchored in the identity of the inhabitants of Zapotitlán and regional cuisine. Salt has endured over the centuries as a perennial resource and constitutes a source of income for its owners. However, despite these historical and cultural factors of territorial anchorage, salters have not attained the level of organization necessary to obtain a fair value in the market. Failure to appreciate this product has led to the abandonment of a large percentage of the saltworks that once existed. This essay will analyze the socio-economic and cultural constraints that have prevented this community from attaining the level of territorial governance necessary to enhance the market value of Zapotitlán salt on the market but how, with the depletion of other economic options, its people are returning to the salt, with new strategies. Lastly, the paper will conclude with a consideration of its future potential.La producción de sal de Zapotitlán de las Salinas (Puebla, México se remonta a épocas prehispánicas cuando los popolocas, moradores del valle de Tehuacán, lo tributaban a los aztecas. La técnica para la obtención de la sal ha cambiado poco desde hace 500 años y el saber-hacer se sigue transmitiendo entre las generaciones de salineros. Es un recurso profundamente anclado en la identidad de los habitantes de Zapotitlán y en la gastronomía regional. Su existencia ha perdurado en el transcurso de los siglos por ser un recurso perenne y constituir una renta para sus dueños. Sin embargo, a pesar de los factores históricos y culturales de anclaje territorial, los salineros no

  17. Composição química, atividade antibacteriana in vitro e toxicidade em Artemia salina do óleo essencial das inflorescências de Ocimum gratissimum L., Lamiaceae Chemical composition, antibacterial activity in vitro and brine-shrimp toxicity of the essential oil from inflorescences of Ocimum gratissimum L., Lamiaceae.

    Directory of Open Access Journals (Sweden)

    Lenise L. Silva

    2010-11-01

    Full Text Available O óleo essencial das inflorescências de Ocimum gratissimum L., Lamiaceae foi obtido por hidrodestilação e analisado por CG/EM. Os constituintes majoritários identificados foram eugenol (81,94% e γ-muuroleno (12,58%. O óleo essencial das inflorescências demonstrou atividade antibacteriana frente a todas as cepas bacterianas testadas pelo método de microdiluição em caldo. Merece destaque a atividade verificada frente às cepas resistentes de Enterococcus faecalis, Staphylococcus aureus e Escherichia coli. Os valores obtidos de concentração inibitória mínima (CIM e a concentração bactericida mínima (CBM variaram, respectivamente, entre 0,5-2 mg/mL e 1-4 mg/mL. Valores de CL50 de 233,8 (200,7-272,0 µg/mL para o óleo essencial e 186,1 (144,1-228,5 µg/mL para o eugenol, utilizado como controle positivo, foram observados frente à Artemia salina L.The essential oil obtained by hydrodistillation of the inflorescences of Ocimum gratissimum L. was analyzed by GC/MS. The main constituents were eugenol (81.94% and γ-muurolene (12.58%. Antibacterial activity was shown against all assayed strains by the broth microdilution method. It's worth noting the activity against resistant strains of Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC values ranged between 0.5-2 mg/mL and 1-4 mg/mL, respectively. Preliminary toxicity assayed by the brine-shrimp (Artemia salina L. test showed LC50 values of 233.8 (200.7 - 272.0 µg/mL and 186.1 (144.1 - 228.5 µg/mL, respectively for the essential oil and eugenol (positive control.

  18. Chemical composition of microalgae Heterochlorella luteoviridis and Dunaliella tertiolecta with emphasis on carotenoids.

    Science.gov (United States)

    Diprat, Andressa Bacalau; Menegol, Tania; Boelter, Juliana Ferreira; Zmozinski, Ariane; Rodrigues Vale, Maria Goreti; Rodrigues, Eliseu; Rech, Rosane

    2017-08-01

    Microalgae have been used as food supplements owing to their high protein, polyunsaturated fatty acid and carotenoid contents. As different carotenoids have distinct properties and the carotenoid composition of microalgae has been poorly explored in the literature, this study determined the complete carotenoid composition of two microalgae species, Heterochlorella luteoviridis and Dunaliella tertiolecta, using high-performance liquid chromatography coupled with diode array detection and tandem mass spectrometry (HPLC-DAD/MS 2 ). Additionally, the proximate composition and major minerals were evaluated. The carotenoid composition of the two microalgae was similar, with 13 carotenoids being found in H. luteoviridis and 12 in D. tertiolecta. The major carotenoids were all-trans-lutein (1.18 mg g -1 in H. luteoviridis and 1.59 mg g -1 in D. tertiolecta), all-trans-violaxanthin (0.52 mg g -1 in H. luteoviridis and 0.45 mg g -1 in D. tertiolecta) and all-trans-β-carotene (0.50 mg g -1 in H. luteoviridis and 0.62 mg g -1 in D. tertiolecta). All-trans-lutein was the predominant carotenoid in both microalgae, representing around 40% (mass fraction) of the total carotenoids. The lutein content found in these microalgae was significantly higher (2-40 times) than that in other important food sources of lutein (e.g. parsley, carrot, red pepper and broccoli). The microalgae H. luteoviridis and D. tertiolecta are excellent sources of lutein that could be commercially exploited by the food and pharmaceutical industries. Moreover, it was confirmed that both microalgae are good sources of protein, lipids and calcium. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Determination of the atomic C/N assimilation ratio values of a pure culture of dunaliella and samples from rivers in Terengganu using the sup 14 C tracer method

    International Nuclear Information System (INIS)

    Lokman bin Shamsudin

    1990-01-01

    The C/N assimilation ratio has been defined by Chan and Raine as the ratio of carbon assimilated by a given algal population to that of the total inorganic nitrogen assimilated. The apparent carbon to nitrogen assimilation ratio for Dunaliella (pure algal culture) as well as subsurface water taken from some rivers in Terengganu was mainly attributed to the assimilation of the type of inorganic nitrogen, namely ammonium or nitrate found in the medium. The high C/N value for the various water samples was mainly attributed to the assimilation of ammonium nitrogen available in large amount in the tropical aquatic environment. The ammonium-nitrogen contents exceeds that of nitrate contents at the two stations

  20. Identifikasi Metabolit Sekunder Ekstrak Etil Asetat Biji Alpukat (Persea americana Mill. dan Uji Toksisitas Terhadap Larva Udang Artemia salina Leach.

    Directory of Open Access Journals (Sweden)

    Nurdia Asdar

    2014-07-01

    Full Text Available Identification of metabolite compound in acetone Extract from Fruits Avocado seed (Percea americana Mill and toxicity test against Artemia salina Leach. Aim of this research is to identify the secondary metabolite compound in aceton extract from fruits Avocado seed (Percea americana Mill and to determine the potential of secondary metabolites from an avocado extract as anticancer. The compound was obtained from Identification process in several stages, namely extraction, fractination, purification and identification. The identification process was color test, TLC, spectroscopy IR. The toxicity test by Brine Shrimp Lethality Test (BSLT to Artemia salina Leach. The compound obtained from this research was yellow-white crystalline needle-shaped, the purity test with TLC analysis showed a stain in three eluen system on the stain test on three eluent systems with Rf proportions as follows; 0,15 from chloroform:ethyl acetat (6:4, 0,33 from methanol:chloroform (1:9, 0,75 for acetone:ethyl acetat, and positively to the reagent Wagner and gave brown precipitate for indicate as alcaloid group. This result is supported by spectroscopy from compound.While toxicity tests showed condensed acetone extracts  and pure compounds are toxic with LC50 value of each is 20.61 mg/mL and 39,81 mg/mL.

  1. Nivel de conocimiento sobre tuberculosis pulmonar y actitud de los pacientes, centro salud San Juan de Salinas, 2017

    OpenAIRE

    Atuncar Mendoza, Pamela

    2017-01-01

    El objetivo del estudios de investigación fue determinar la relación que existe entre el nivel de conocimiento sobretuberculosis pulmonar y la actitud hacia el tratamiento detuberculosis pulmonar de los pacientes dela Estrategia Sanitaria Nacional de Prevención y Control de la Tuberculosis, Centro de Salud San Juan de Salinas, San Martinde Porres, año 2017. En cuanto a lametodología fue de tipo de investigación aplicada, nivel descriptivo correccional,la población estuvo conformada por 50 p...

  2. Caracterización y perfil lipídico de aceites de microalgas

    Directory of Open Access Journals (Sweden)

    Lesly Tejeda-Benítez

    2015-05-01

    Full Text Available El uso creciente del biodiésel ha impulsado la búsqueda de nuevas materias primas, dentro de las que se destacan las microalgas. En esta investigación se estudió el cultivo de las microalgas Chlorella sp. y Dunaliella salina bajo diferentes condiciones de pH y concentración de nitrógeno (mgL-1, y la caracterización de los aceites obtenidos, con el fin de evaluar su potencial uso como materia prima en la producción de biodiésel. La D. salina alcanzó una máxima concentración celular de 1.15x106 células mL-1 en 6 días de cultivo en unas condiciones de 8.5 pH y 0.1 mg L-1 concentración de nitrógeno, mientras que Chlorella sp. presentó una máxima concentración celular de 2.6x107 células mL-1 en 14 días de cultivo en unas condiciones de 7.5 pH y 0.1 mg L-1 concentración de nitrógeno. La extracción de aceite intracelular de las microalgas cultivadas bajo las mejores condiciones de crecimiento celular se realizó empleando el método modificado de Bligh & Dyer. Al determinar el perfil de ácidos grasos de los aceites extraídos de ambas microalgas, se  encontraron en mayor proporción dos ácidos grasos insaturados: ácido linolénico y ácido oleico. En el aceite de D. salina se encontró una concentración de 51% p/p de ácido linolénico, mientras que para el aceite de Chlorella sp. fue de 39% p/p. Con relación al ácido oleico, el aceite de Chrorella sp. presentó una concentración de 35% p/p, superior al aceite de D. salina, con 25% p/p.

  3. Processing recommendations for using low-solids digestate as nutrient solution for poly-ß-hydroxybutyrate production with Synechocystis salina.

    Science.gov (United States)

    Meixner, K; Fritz, I; Daffert, C; Markl, K; Fuchs, W; Drosg, B

    2016-12-20

    Within the last decades, environmental pollution with persistent plastics steadily increased; therefore the production of biodegradable materials like poly-ß-hydroxybutyrate (PHB) is essential. Currently, PHB is produced with heterotrophic bacteria from crops. This leads to competition with food and feed production, which can be avoided by using photoautotrophic cyanobacteria, as Synechocystis salina, synthesizing PHB from CO 2 at nutrient limitation. This study aims to increase the economic efficiency of PHB production with cyanobacteria by using nutrients from anaerobic digestate. First, growth and PHB production of S. salina in digestate fractions (supernatant and permeate, with/without precipitating agents) and dilutions thereof and then the scale-up (photobioreactor, 200 L working volume) were evaluated. With precipitated and centrifuged digestate diluted 1/3 the highest biomass (1.55gL -1 ) and PHB concentrations (95.4mgL -1 ), being 78% of those in mineral media, were achieved. In the photobioreactor-experiments biomass (1.63gL -1 ) and PHB concentrations (88.7mgL -1 ), being 79% and 72% of those in mineral medium, were reached, but in a cultivation time 10days longer than in mineral medium. The possibility to use digestate as sustainable and low cost nutrient solution for microalgae cultivation and photoautotrophic PHB production, instead of applying it on fields or processing it to achieve discharge limits, makes this application a highly valid option. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Pollution by polycyclic aromatic hydrocarbons (PAH's) in sediments and organisms from Salina Cruz Port, Oaxaca, Mexico

    International Nuclear Information System (INIS)

    Botello, A.V.; Villanueva, S.; Diaz, G.; Pica, Y.

    1995-01-01

    The presence and levels of polycyclic aromatic hydrocarbons (PAH's) in [sediments and biota from the Port of Salina Cruz, Oaxaca; were evaluated by means of gas capillary chromatography using columns of high resolution. The results show a seasonal variability of the PAH's concentrations in sediments being higher in the port area and lower in oceanic sediments. The increase of the PAH's levels in Crassostrea iridiscens and Penaeus stylirostris is important and related to the bioaccumulation process. The presence of PAH's conformed by 4 y 5 benzene rings in these species must be noted specially because they have carcinogenic properties and their effects on the local fisheries should be considered. (Author)

  5. High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae.

    Science.gov (United States)

    Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

    2015-06-01

    We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration-dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5mg/mL carbon black and 0.1mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Crescimento, consumo hídrico e composição mineral de alface cultivada em hidroponia com águas salinas

    Directory of Open Access Journals (Sweden)

    Dalva Paulus

    2012-02-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o crescimento, o consumo hídrico e a extração de nutrientes, por alface (Lactuca sativa L. em sistema hidropônico NFT (fluxo laminar de nutrientes, com a utilização de águas salinas no preparo da solução nutritiva e reposição da lâmina diária evapotranspirada. Foram conduzidos dois experimentos, em ambiente protegido. O delineamento experimental foi em blocos ao acaso, sendo estudados os efeitos de cinco níveis de salinidade da água, utilizando-se NaCl. O aumento da salinidade da água reduziu, de forma linear, o crescimento e o consumo hídrico da alface. A salinidade reduziu a concentração de macronutrientes na parte aérea, mas não se observaram sintomas de deficiência nutricional. O rendimento (massa de matéria fresca da parte aérea foi reduzido entre 6 e 6,5% por dS m-1, no primeiro e segundo cultivo, respectivamente. Os resultados obtidos em sistema de cultivo NFT podem indicar a possibilidade do uso da água salina como alternativa para produção de hortaliças, para produtores que têm disponibilidade restrita de água doce, porém, com redução de produtividade.

  7. Ethanol fermentation with Kluyveromyces marxianus from Jerusalem artichoke grown in salina and irrigated with a mixture of seawater and freshwater.

    Science.gov (United States)

    Yuan, W J; Zhao, X Q; Ge, X M; Bai, F W

    2008-12-01

    To study fuel ethanol fermentation with Kluyveromyces marxianus ATCC8554 from Jerusalem artichoke (Helianthus tuberosus) grown in salina and irrigated with a mixture of seawater and freshwater. The growth and ethanol fermentation of K. marxianus ATCC8554 were studied using inulin as substrate. The activity of inulinase, which attributes to the hydrolysis of inulin, the main carbohydrate in Jerusalem artichoke, was monitored. The optimum temperatures were 38 degrees C for growth and inulinase production, and 35 degrees C for ethanol fermentation. Aeration was not necessary for ethanol fermentation with the K. marxianus from inulin. Then, the fresh Jerusalem artichoke tubers grown in salina and irrigated with 25% and 50% seawater were further examined for ethanol fermentation with the K. marxianus, and a higher ethanol yield was achieved for the Jerusalem artichoke tuber irrigated with 25% seawater. Furthermore, the dry meal of the Jerusalem artichoke tubers irrigated with 25% seawater was examined for ethanol fermentation at three solid concentrations of 200, 225 and 250 g l(-1), and the highest ethanol yield of 0.467, or 91.5% of the theoretical value of 0.511, was achieved for the slurry with a solid concentration of 200 g l(-1). Halophilic Jerusalem artichoke can be used for fuel ethanol production. Halophilic Jerusalem artichoke, not competing with grain crops for arable land, is a sustainable feedstock for fuel ethanol production.

  8. Estudo de processos de produção de etanol anidro através da destilação extrativa salina com recuperação do agente de separação

    OpenAIRE

    Eliana Luci Ligero

    1999-01-01

    Resumo: : Uma técnica amplamente utilizada na produção de etanol é a destilação azeotrópica benzeno, cuja propriedade cancerígena é bastante conhecida. Um processo alternativo, ecologicamente viável, é a destilação extrativa salina. O emprego de um sal solúvel na desidratação do etanol possibilita uma redução no consumo energético, além de produzir um etanol livre do agente de separação. Uma etapa importante na produção de etanol anidro através da destilação extrativa salina é a recuperação d...

  9. Establishment of an efficient genetic transformation method in Dunaliella tertiolecta mediated by Agrobacterium tumefaciens.

    Science.gov (United States)

    Norzagaray-Valenzuela, Claudia D; Germán-Báez, Lourdes J; Valdez-Flores, Marco A; Hernández-Verdugo, Sergio; Shelton, Luke M; Valdez-Ortiz, Angel

    2018-05-16

    Microalgae are photosynthetic microorganisms widely used for the production of highly valued compounds, and recently they have been shown to be promising as a system for the heterologous expression of proteins. Several transformation methods have been successfully developed, from which the Agrobacterium tumefaciens-mediated method remains the most promising. However, microalgae transformation efficiency by A. tumefaciens is shown to vary depending on several transformation conditions. The present study aimed to establish an efficient genetic transformation system in the green microalgae Dunaliella tertiolecta using the A. tumefaciens method. The parameters assessed were the infection medium, the concentration of the A. tumefaciens and co-culture time. As a preliminary screening, the expression of the gusA gene and the viability of transformed cells were evaluated and used to calculate a novel parameter called Transformation Efficiency Index (TEI). The statistical analysis of TEI values showed five treatments with the highest gusA gene expression. To ensure stable transformation, transformed colonies were cultured on selective medium using hygromycin B and the DNA of resistant colonies were extracted after five subcultures and molecularly analyzed by PCR. Results revealed that treatments which use solid infection medium, A. tumefaciens OD 600  = 0.5 and co-culture times of 72 h exhibited the highest percentage of stable gusA expression. Overall, this study established an efficient, optimized A. tumefaciens-mediated genetic transformation of D. tertiolecta, which represents a relatively easy procedure with no expensive equipment required. This simple and efficient protocol opens the possibility for further genetic manipulation of this commercially-important microalgae for biotechnological applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Avaliação da atividade tóxica em Artemia salina e Biomphalaria glabrata de extratos de quatro espécies do gênero Eleocharis (Cyperaceae

    Directory of Open Access Journals (Sweden)

    A.L.T.G. Ruiz

    Full Text Available O gênero Eleocharis R. Br. compreende cerca de 200 espécies, ocorrendo em ambientes úmidos tais como brejos e margens de rios e lagos. Procurando novos agentes moluscicidas, os extratos de Eleocharis acutangula (Roxb. Schult., Eleocharis interstincta (Vahl Roem. & Schult., Eleocharis maculosa (Vahl Roem. & Schult. e Eleocharis sellowiana Kunth foram testados para atividade moluscicida, contra caramujos adultos e desovas, e toxicidade (ensaio de letalidade com Artemia salina. O extrato hexânico de Eleocharis acutangula (parte subterrânea fresca foi ativo contra Artemia salina (CL50 = 476,00 mg/mL, enquanto os demais extratos apresentaram CL50 >> 10³ mg/mL, sugerindo baixa toxicidade. O extrato hidro-etanólico de Eleocharis sellowiana (parte subterrânea fresca foi ativo contra desovas de Biomphalaria glabrata (CL50 = 24,27 mg/mL mas inativo contra indivíduos adultos. Os demais extratos testados não apresentaram atividade moluscicida.

  11. Temperature-dose relationships with aflatoxin M1 in milk on the brine shrimp (Artemia salina larvae

    Directory of Open Access Journals (Sweden)

    Lejla Duraković

    2011-06-01

    Full Text Available Temperature-dose relationships with aflatoxin M1 (AFM1 were studied using the brine shrimp Artemia salina larvae as an biological indicator in the temperature range from 20 °C to 40 °C. Increase in the incubation temperature resulted in sensitivity increase by the brine shrimp to AFM1. Optimum sensitivity occured at 30 °C. Positive results were obtained at 0.18 μg AFM1 x L-1 of whole pasteurized milk with a mortality of over 15%. Greater than 90 % mortality occurred at dose levels of 0.9 μg AFM1 x L-1 and above. The test can be conducted during 30-60 hours.

  12. Pomada orgânica natural ou solução salina isotônica no tratamento de feridas limpas induzidas em ratos

    Directory of Open Access Journals (Sweden)

    Rahal Sheila Canevese

    2001-01-01

    Full Text Available Foram utilizados 40 ratos Wistar, machos, com peso inicial médio de 225 gramas, separados em dois grupos. Após serem anestesiados com éter, foi induzida uma ferida limpa na região torácica dorsal cranial, mediante a utilização de molde metálico de 2,0 x 1,5cm. No grupo I, foi utilizada pomada contendo óleo de fígado de bacalhau, extrato de confrei, extrato cítrico, óxido de zinco e veículo (Creamex®; no grupo II, a ferida foi apenas limpa com solução salina isotônica. Para a avaliação histológica, foram submetidos à eutanásia cinco animais de cada grupo no 3º, 7º, 14º e 21º dia de pós-operatório. O grupo tratado com a pomada orgânica apresentou padrão cicatricial de qualidade superior em relação ao grupo tratado com salina isotônica, representado por formação de fibras colágenas, neoformação de vasos e reepitelização completa da epiderme.

  13. IDENTIFIKASI DAN UJI AKTIVITAS ANTIKANKER EKSTRAK SPONS Ianthella basta TERHADAP LARVA Artemia salina L.

    Directory of Open Access Journals (Sweden)

    Ni Wayan Sri Sukmarianti

    2013-05-01

    Full Text Available The main purpose of this research is to determine the toxicity of extracts sponge Ianthella basta against Artemia salina larvae and to identify the chemical compounds contained in those toxic isolates. The preliminary test of the anticancer activity has conducted by Brine Shrimp Letalithy (BST test. The results showed that the chloroform extract was the most toxic with LC50 value of 22,39 ppm. Futher, the cloroform extract was separated and purified by coloumn chromatography using eluent of solvent mixture of chloroform : ethyl acetate : n-hexane by 7 : 2 : 1 and 4 fractions were obtained. The most toxic fraction was the fraction C with LC50 value of 35,36 ppm. Based on the GC-MS results, the toxic isolate is allegedly containing chemicals compound of hexadecanoic methyl ester and hexadecanoic acid.

  14. Effect of salinity on metal mobility in Sečovlje salina sediment (northern Adriatic, Slovenia)

    Science.gov (United States)

    Kovač, N.; Ramšak, T.; Glavaš, N.; Dolenec, M.; Rogan Šmuc, N.

    2016-12-01

    Saline sediment (saline healing mud or "fango") from the Sečovlje Salina (northern Adriatic, Slovenia) is traditionally used in the coastal health resorts as a virgin material for medical treatment, wellness and relax purposes. Therapeutic qualities of the healing mud depend on its mineralogical composition and physical, mineralogical, geochemical and biological properties. Their microbial and potentially toxic elements contamination are the most important features affecting user safety. However, the degree of metal toxicity (and its regulation) for natural healing mud is still under discussion. Therefore, the influence of the overlying water salinity on the mobility of heavy metals (and some other geochemical characteristic) was studied for saline sediments of the Sečovlje Salina. Experiments takes place in tanks under defined conditions i.e. at day (21 °C): night (16 °C) cycle for three months. Sediment was covered with water of different salinities (36, 155, 323 g NaCl L-1 and distillate water) and mixed/stirred every week during the experimental period. At the same time, the evaporated water was replaced with distilled water. The mud samples were analyzed, at the beginning and at the end of experiment, for mineral (XRD), elemental composition (ICP-MS) and organic content (% TOC, % TN). Geochemical analysis of the aqueous phase (content of cations and anions) have also been carried out in an accredited Canadian laboratory Actlabs (Activation Laboratories, Canada). Salinity and maturation of sediment does not significantly affect its mineral composition. The samples taken at the end of the experiment have higher percent of water but lower organic carbon concentration. Concentrations of investigated elements are comparable to that in surface sediments from Central Adriatic Sea. In the water phase, concentrations of most elements (As, Ba, Cu, Mo, Mn, Ni, Sr, Sb) rise from the beginning to the end of the experiment, whereas the metal (potentially toxic elements

  15. Changes in lake levels, salinity and the biological community of Great Salt Lake (Utah, USA), 1847-1987

    Science.gov (United States)

    Stephens, D.W.

    1990-01-01

    Great Salt Lake is the fourth largest terminal lake in the world, with an area of about 6000 square kilometers at its historic high elevation. Since its historic low elevation of 1277.52 meters in 1963, the lake has risen to a new historic high elevation of 1283.77 meters in 1986-1987, a net increase of about 6.25 meters. About 60 percent of this increase, 3.72 meters, has occurred since 1982 in response to greater than average precipitation and less than average evaporation. Variations in salinity have resulted in changes in the composition of the aquatic biological community which consists of bacteria, protozoa, brine shrimp and brine flies. These changes were particularly evident following the completion of a causeway in 1959 which divided the lake. Subsequent salinities in the north part of the lake have ranged from 16 to 29 percent and in the south part from 6 to 28 percent. Accompanying the rise in lake elevation from 1982 to 1987 have been large decreases in salinity of both parts of the lake. This has resulted in changes in the biota from obligate halophiles, such as Dunaliella salina and D. viridis, to opportunistic forms such as a blue-green alga (Nodularia spumigena). The distribution and abundance of brine shrimp (Artemia salina) in the lake also have followed closely the salinity. In 1986, when the salinity of the south part of the lake was about 6 percent, a population of brackish-water killifish (Lucania parva) was observed along the shore near inflow from a spring. ?? 1990 Kluwer Academic Publishers.

  16. Reposição de volume na sepse com solução salina hipertônica Sepsis volume reposition with hypertonic saline solution

    Directory of Open Access Journals (Sweden)

    Gilberto Friedman

    2008-09-01

    Full Text Available Esta revisão discute os efeitos hemodinâmicos e imunomoduladores da solução hipertônica em choque experimental e em pacientes com sepse. Comentamos sobre os mecanismos de ação da solução hipertônica, recorrendo a dados sobre choque hemorrágico e séptico. Atuações específicas da solução salina hipertônica aplicáveis a sepse grave e choque séptico são enfatizadas. Os dados disponíveis corroboram os benefícios em potencial da infusão de solução salina hipertônica em vários aspetos da fisiopatologia da sepse, inclusive hipoperfusão dos tecidos, consumo reduzido de oxigênio, disfunção endotelial, depressão miocárdica e presença de um amplo elenco de citocinas próinflamatórias e várias espécies de oxidantes. Uma terapia que, ao mesmo tempo, bloqueie os componentes prejudiciais da sepse terá um impacto no seu tratamento. Estudos prospectivos adequadamente desenhados poderão no futuro comprovar o papel benéfico da solução salina hipertônica.The present review discusses the hemodynamic and immune-modulatory effects of hypertonic saline in experimental shock and in patients with sepsis. We comment on the mechanisms of action of hypertonic saline, calling upon data in hemorrhagic and septic shock. Specific actions of hypertonic saline applicable to severe sepsis and septic shock are highlighted. Data available support potential benefits of hypertonic saline infusion in various aspects of the pathophysiology of sepsis, including tissue hypoperfusion, decreased oxygen consumption, endothelial dysfunction, cardiac depression, and the presence of a broad array of pro-inflammatory cytokines and various oxidant species. A therapy that simultaneously blocks the damaging components of sepsis will have an impact on the management of sepsis. Proper designed prospective studies may prove a beneficial role for hypertonic saline solution in the future.

  17. Cytotoxicity effects of water dispersible oxidized multiwalled carbon nanotubes on marine alga, Dunaliella tertiolecta

    International Nuclear Information System (INIS)

    Wei Liping; Thakkar, Megha; Chen Yuhong; Ntim, Susana Addo; Mitra, Somenath; Zhang Xueyan

    2010-01-01

    The multiwalled carbon nanotubes (MWNTs) are novel materials with many potential applications. The ecotoxicity of these materials is not well studied, but it is essential for environmental impact assessments. In this study a commercially available MWNT material was carboxylated by microwave assisted acid oxidation. This functionalized MWNT (f-MWNT) material was examined for toxicity effects using unicellular marine green alga Dunaliella tertiolecta. D. tertiolecta was exposed to f-MWNT which had been pre-equilibrated with culture media for 24 h. Substantial growth lag phase was observed at 5 and 10 mg L -1 f-MWNT, and the resulting 50% effective concentration (EC50) on 96-h growth was 0.82 ± 0.08 mg L -1 . During mid-exponential growth phase cytotoxicity was evidenced at 10 mg L -1 f-MWNT in 36% reduction in exponential growth rate, 88 mV more positive glutathione redox potential (indicative of oxidative stress), 5% and 22% reduction in photosystem II (PSII) quantum yield and functional cross section respectively, all relative to the control cultures. However, when the large f-MWNT aggregates in the media with 10 mg L -1 f-MWNT were removed by 0.2 μm filtration, D. tertiolecta did not show significant cytotoxicity effects in any of the above parameters. This suggests that the cytotoxicity effects originated predominately from the large f-MWNT aggregates. Analysis of the f-MWNT aggregation dynamics suggests active interaction between f-MWNT and algal cells or cell metabolites that promoted f-MWNT aggregation formation. The f-MWNT particles were also found absorbed on algal cell surface. The direct contact between f-MWNT and cell surface was likely responsible for reduced PSII functional cross section and oxidative stress during exponential growth.

  18. Superimposed extension and shortening in the southern Salinas Basin and La Panza Range, California: A guide to Neogene deformation in the Salinian block of the central California Coast Ranges

    Science.gov (United States)

    Colgan, Joseph P.; McPhee, Darcy K.; McDougall, Kristin; Hourigan, Jeremy K.

    2013-01-01

    We synthesized data from geologic maps, wells, seismic-reflection profiles, potential-field interpretations, and low-temperature thermochronology to refine our understanding of late Cenozoic extension and shortening in the Salinian block of the central California Coast Ranges. Data from the La Panza Range and southern Salinas Basin document early to middle Miocene extension, followed by Pliocene and younger shortening after a period of little deformation in the late Miocene. Extension took place on high-angle normal faults that accommodated ∼2% strain at the scale of the ∼50-km-wide Salinian block (oriented perpendicular to the San Andreas fault). Shortening was accommodated by new reverse faults, reactivation of older normal faults, and strike-slip faulting that resulted in a map-view change in the width of the Salinian block. The overall magnitude of shortening was ∼10% strain, roughly 4–5 times greater than the amount of extension. The timing and magnitude of deformation in our study area are comparable to that documented in other Salinian block basins, and we suggest that the entire block deformed in a similar manner over a similar time span. The timing and relative magnitude of extension and shortening may be understood in the context of central Coast Range tectonic boundary conditions linked to rotation of the western Transverse Ranges at the south end of the Salinian block. Older models for Coast Range shortening based on balanced fault-bend fold-style cross sections are a poor approximation of Salinian block deformation, and may lead to mechanically improbable fault geometries that overestimate the amount of shortening.

  19. IL MUSEO SALINAS, PARADOSSO DEL WEB MARKETING CULTURALE La comunicazione archeologica ai tempi dei social media, a museo chiuso

    Directory of Open Access Journals (Sweden)

    Elisa Bonacini

    2016-11-01

    Full Text Available The aim of this paper is to offer the case study of the archaeological museum Antonino Salinas in Palermo, that - closed for many years for the restoration of the architectural complex that houses it, the seventeenth-century Olivella’ s House of the Philippine Fathers - has invented new strategies of the archaeological communication on the social media. After two years, waiting for its reopening, the museum has been able to create a real brand and to renovate the museum’s reputation. The solutions adopted by the Museum could “inspire” other institutions to adopt those web marketing cultural strategies.

  20. Coculture induced improved production of biosurfactant by Staphylococcus lentus SZ2: Role in protecting Artemia salina against Vibrio harveyi.

    Science.gov (United States)

    Hamza, Faseela; Kumar, Ameeta Ravi; Zinjarde, Smita

    2018-07-01

    Coculturing microorganisms can lead to enhanced production of bioactive compounds as a result of cross-species or cross-genera interactions. In this study, we demonstrate improved production of the biosurfactant (BS-SLSZ2 with antibiofilm properties) by the marine epibiotic bacterium Staphylococcus lentus SZ2 after cross-genera interactions with an aquaculture pathogen Vibrio harveyi. In cocultures, growth of V. harveyi was completely inhibited and resultant biofilms were exclusively composed of S. lentus. The cell free supernatant (CFS) derived from cocultures displayed improved antibiofilm activity with enhanced contents of BS-SLSZ2 compared to monocultured S. lentus. During coculture experiments, after short periods of incubation (6 and 12 h), 2.3 fold increased production of BS-SLSZ2 was observed. Planktonic growth of V. harveyi was also inhibited after coculturing with S. lentus as evidenced from plate culture-based studies and microscopic observations. The CFS derived from monocultures and cocultures did not display bactericidal activity and the observed inhibition of V. harveyi could be of competitive nature. During in vivo challenge experiments, S. lentus protected the model aquaculture system Artemia salina from V. harveyi infections. Seven days post infection, survival of the group of larvae infected with V. harveyi was 5 ± 4.47%. Better survival rates (73.33 ± 5.16%, comparable with the unexposed group) were observed in the group of larvae incubated with S. lentus and V. harveyi. This study highlights increased biosurfactant production by cocultured S. lentus and the application of this bacterium as a protective probiotic strain for inclusion in aquaculture practices. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Variación espacial y temporal de la diversidad de hormigas en el Jardín Botánico del valle de Zapotitlán de las Salinas, Puebla Spatial and temporal variation of the diversity ants in the Botanic Garden from Zapotitlán de las Salinas Valley, Puebla

    Directory of Open Access Journals (Sweden)

    Rafael Guzmán-Mendoza

    2010-08-01

    Full Text Available Debido al escaso conocimiento que se tiene de las hormigas de las zonas áridas de México, se evaluó la biodiversidad de este taxón en el Jardín Botánico de Zapotitlán de las Salinas, Puebla. Se realizaron 2 colectas, una en época de lluvias (agosto de 2004 y otra en la temporada de secas (febrero de 2005. En ambas ocasiones se seleccionaron 2 sitios contrastantes en estructura vegetal y se colocaron 10 trampas de caída para cada sitio. La captura fue más abundante en temporada de lluvias. El sitio con menor diversidad y cobertura vegetal mostró una mayor diversidad de hormigas durante el estudio. Comparado con otras zonas áridas de México, el valle de Zapotitlán de las Salinas resultó ser una de las zonas semiáridas con mayor riqueza en especies de hormigas; con 12 nuevos registros se incrementó a 27 el número de especies, sólo una por debajo de otras localidades cercanas al valle. Los datos sugieren que con un mayor esfuerzo de muestreo y la aplicación combinada de otras técnicas de recolección, la riqueza de especies en el área podría elevarse considerablemente.The knowledge about ants of arid zones of Mexico is very poor. For this reason we assessed the biodiversity of this taxon in 2 sites with different vegetation structure. Ten pitfall traps were placed in each site, and 2 surveys were conducted, 1 in August (rainy season, 2004 and another in February (dry season, 2005. The capture was more abundant in the rainy season; however, during the study, a higher ant diversity was observed in the site with low vegetation cover and few plant diversity. Compared with other arid zones of Mexico, the Zapotitlán de las Salinas Valley is the site with the highest ant species richness. The new records have increased richness to 27 ant species, which is very close to the number of species registered in other localities near Zapotitlan. Our data suggest that increasing sampling effort and application of different sampling

  2. Efficacy and toxicity of self-polishing biocide-free antifouling paints

    International Nuclear Information System (INIS)

    Loeschau, Margit; Kraetke, Renate

    2005-01-01

    The ban on harmful substances in antifouling paints requires the development of new antifouling strategies. Alternatives should be as effective as conventional paints but of lower toxicity. In the present study two commercially available, self-polishing antifouling paints were examined in order to get information on their antifouling properties and toxicological potential. Efficacy was shown in settlement assays with the marine barnacle species Balanus amphitrite, however, efficacy was related to toxic effects observed on target and non-target organisms. Toxicity of the paint extracts was concentration-dependent and differed according to the paint and the species investigated. Toxicity could at least partially be attributed to zinc leached from the paints. Effects of a water-soluble paint were more pronounced in larvae of B. amphitrite, Artemia salina and in the green algae Dunaliella tertiolecta. Embryos of the freshwater species Danio rerio and Vibrio fisheri were more affected by a paint based on organic solvents. - For alternative antifouling paints efficacy as well as adverse effects on non-target organisms and the aquatic environment should be carefully assessed

  3. A Label-Free Microfluidic Biosensor for Activity Detection of Single Microalgae Cells Based on Chlorophyll Fluorescence

    Directory of Open Access Journals (Sweden)

    Junsheng Wang

    2013-11-01

    Full Text Available Detection of living microalgae cells is very important for ballast water treatment and analysis. Chlorophyll fluorescence is an indicator of photosynthetic activity and hence the living status of plant cells. In this paper, we developed a novel microfluidic biosensor system that can quickly and accurately detect the viability of single microalgae cells based on chlorophyll fluorescence. The system is composed of a laser diode as an excitation light source, a photodiode detector, a signal analysis circuit, and a microfluidic chip as a microalgae cell transportation platform. To demonstrate the utility of this system, six different living and dead algae samples (Karenia mikimotoi Hansen, Chlorella vulgaris, Nitzschia closterium, Platymonas subcordiformis, Pyramidomonas delicatula and Dunaliella salina were tested. The developed biosensor can distinguish clearly between the living microalgae cells and the dead microalgae cells. The smallest microalgae cells that can be detected by using this biosensor are 3 μm ones. Even smaller microalgae cells could be detected by increasing the excitation light power. The developed microfluidic biosensor has great potential for in situ ballast water analysis.

  4. Ecotoxicology of bromoacetic acid on estuarine phytoplankton.

    Science.gov (United States)

    Gordon, Ana R; Richardson, Tammi L; Pinckney, James L

    2015-11-01

    Bromoacetic acid is formed when effluent containing chlorine residuals react with humics in natural waters containing bromide. The objective of this research was to quantify the effects of bromoacetic acid on estuarine phytoplankton as a proxy for ecosystem productivity. Bioassays were used to measure the EC50 for growth in cultured species and natural marine communities. Growth inhibition was estimated by changes in chlorophyll a concentrations measured by fluorometry and HPLC. The EC50s for cultured Thalassiosira pseudonana were 194 mg L(-1), 240 mg L(-1) for Dunaliella tertiolecta and 209 mg L(-1) for Rhodomonas salina. Natural phytoplankton communities were more sensitive to contamination with an EC50 of 80 mg L(-1). Discriminant analysis suggested that bromoacetic acid additions cause an alteration of phytoplankton community structure with implications for higher trophic levels. A two-fold EC50 decrease in mixed natural phytoplankton populations affirms the importance of field confirmation for establishing water quality criteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A Label-Free Microfluidic Biosensor for Activity Detection of Single Microalgae Cells Based on Chlorophyll Fluorescence

    Science.gov (United States)

    Wang, Junsheng; Sun, Jinyang; Song, Yongxin; Xu, Yongyi; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

    2013-01-01

    Detection of living microalgae cells is very important for ballast water treatment and analysis. Chlorophyll fluorescence is an indicator of photosynthetic activity and hence the living status of plant cells. In this paper, we developed a novel microfluidic biosensor system that can quickly and accurately detect the viability of single microalgae cells based on chlorophyll fluorescence. The system is composed of a laser diode as an excitation light source, a photodiode detector, a signal analysis circuit, and a microfluidic chip as a microalgae cell transportation platform. To demonstrate the utility of this system, six different living and dead algae samples (Karenia mikimotoi Hansen, Chlorella vulgaris, Nitzschia closterium, Platymonas subcordiformis, Pyramidomonas delicatula and Dunaliella salina) were tested. The developed biosensor can distinguish clearly between the living microalgae cells and the dead microalgae cells. The smallest microalgae cells that can be detected by using this biosensor are 3 μm ones. Even smaller microalgae cells could be detected by increasing the excitation light power. The developed microfluidic biosensor has great potential for in situ ballast water analysis. PMID:24287532

  6. Hydrothermal liquefaction of high- and low-lipid algae: Mass and energy balances.

    Science.gov (United States)

    Cheng, Feng; Cui, Zheng; Mallick, Kwonit; Nirmalakhandan, Nagamany; Brewer, Catherine E

    2018-06-01

    Hydrothermal liquefaction (HTL) of high-lipid microalgae Nannochloropsis salina (N. salina) and low-lipid microalgae Galdieria sulphuraria (G. sulphuraria) were run under subcritical conditions (310-350 °C and 10-17 MPa) in a 1.8 L batch autoclave system. HTL mass and energy balances for both species were compared under different operating conditions to predict the optimum reaction conditions for new algae strains based on their feedstock composition. Bio-crude oils and chars were characterized by bomb calorimetry, elemental analysis, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis (TGA). Under the optimized conditions, 59 wt% and 31 wt% bio-crude oil yields were obtained from HTL of N. salina and G. sulphuraria, while 85% and 59% of the feedstock energy were partitioned into N. salina-derived and G. sulphuraria-derived bio-crude oils, respectively. More favorable energy balances were related to shorter reaction times and higher algal solid contents. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. First secondary metabolites from Herissantia crispa L (Brizicky) and the toxicity activity against Artemia salina Leach

    International Nuclear Information System (INIS)

    Costa, Danielly Albuquerque da; Matias, Wemerson Neves; Lima, Igara Oliveira; Xavier, Aline Lira; Costa, Vivian Bruna Machado; Diniz, Margareth de Fatima Formiga Melo; Agra, Maria de Fatima; Batista, Leonia Maria; Souza, Maria de Fatima Vanderlei de; Silva, Davi Antas e

    2009-01-01

    The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-β-D-glucopyranoside, stigmasterol 3-O-β-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides β-sitosterol, kaempferol 3-O-β-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-α-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, 1 H and 13 C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out. (author)

  8. Diversidade de abelhas visitantes das flores de Citrus em pomares de laranjeira e tangerineira Diversity of flowers visiting bees of Citrus in salinas, state of minas gerais

    Directory of Open Access Journals (Sweden)

    Eduardo Tigre do Nascimento

    2011-03-01

    Full Text Available A presença de abelhas em culturas de valor comercial, no período de florescimento, é importante não apenas para garantir a polinização cruzada, quando indispensável, mas também para incrementar a produção de frutos e sementes. Nessa perspectiva, o presente trabalho teve a finalidade de identificar as abelhas visitantes das flores em pomar de laranjeira (Citrus sinensis e tangerineira (Citrus reticulata em Salinas - MG. O trabalho foi conduzido na fazenda experimental Santa Isabel, da Escola Agrotécnica Federal de Salinas - MG, em pomares de laranjeira com as variedades, pera, baía e baianinha, e de tangerineira, variedade poncã. As coletas das abelhas visitantes das culturas da laranjeira e tangerineira foram feitas nas floradas principais, entre os meses de agosto e outubro. Foram coletadas as abelhas que visitaram as flores nos horários entre 06 h e 18 h, totalizando 52 horas na laranjeira e 50 horas na tangerineira. No pomar de laranjeira, foram coletados 5.045 espécimes com riqueza de 12 espécies, e na tangerineira, 1.428 espécimes com 20 espécies. As espécies de abelhas de maior predominância e dominância em todos os horários amostrados foram Apis mellifera e Trigona spinipes na cultura da laranjeira e A. mellifera, T. spinipes e Tetragonisca angustula na cultura da tangerineira.The presence of bees on cultures with commercial value during flowering is important to ensure the cross-pollination, when necessary, but also to increase the production of fruits and seeds. This work aimed to identify flowers' visiting bees on orange and tangerine orchards in Salinas - MG. The work was leaded on Santa Isabel experimental farm of the Federal Agro-technical School of Salinas - MG, on orange orchards (Citrus sinensis with pear, bahia and baianinha varieties in the spacing of 5,0 x 6,0, and on tangerine orchards (C. reticulate using poncã variety in the spacing of 5,0 x 5,0. The sampling of visiting bees from orange and tangerine

  9. Influência da irrigação intraperitoneal de solução salina em diferentes temperaturas na formação de aderências e prevenção de hipotermia após pneumoperitônio em ratos

    Directory of Open Access Journals (Sweden)

    Oswaldo Lourenço de Molla Neto

    Full Text Available Este estudo experimental em ratos avalia a influência da irrigação da cavidade peritoneal com solução salina isotônica (0,9 %, em diferentes temperaturas, na formação de aderências peritoneais e prevenção de hipotermia após pneumoperitônio. Foram utilizados 80 ratos divididos em quatro grupos de 20 animais: grupo controle (G1 sem irrigação, grupos com irrigação a temperatura ambiente 22,0°C (G2, a 35,0°C (G3 e a 45,0°C (G4. A análise da hipotermia foi realizada através da monitorização da temperatura retal em três diferentes momentos: após a anestesia (T1, cinco minutos depois da insuflação de dióxido de carbono (T2 e cinco minutos após a irrigação com solução salina (T3. Os animais foram sacrificados no 28º dia de pós-operatório. Observaram-se aderências nos grupos com irrigação, sendo que, com salina à temperatura de 45,0ºC houve maior formação de aderências (30,0% , porém, esta diferença não foi significante. No G2 ocorreu uma queda significante na temperatura média retal quando comparada aos demais grupos, demonstrando que a hipotermia na cirurgia laparoscópica pode ser reduzida com o uso de solução salina aquecida.

  10. Crescimento, consumo hídrico e composição mineral de alface cultivada em hidroponia com águas salinas

    OpenAIRE

    Paulus,Dalva; Paulus,Eloi; Nava,Gilmar Antônio; Moura,Cláudia Andrade

    2012-01-01

    Objetivou-se, com este trabalho, avaliar o crescimento, o consumo hídrico e a extração de nutrientes, por alface (Lactuca sativa L.) em sistema hidropônico NFT (fluxo laminar de nutrientes), com a utilização de águas salinas no preparo da solução nutritiva e reposição da lâmina diária evapotranspirada. Foram conduzidos dois experimentos, em ambiente protegido. O delineamento experimental foi em blocos ao acaso, sendo estudados os efeitos de cinco níveis de salinidade da água, utilizando-se Na...

  11. TiO2 nanoparticles in seawater: Aggregation and interactions with the green alga Dunaliella tertiolecta.

    Science.gov (United States)

    Morelli, Elisabetta; Gabellieri, Edi; Bonomini, Alessandra; Tognotti, Danika; Grassi, Giacomo; Corsi, Ilaria

    2018-02-01

    Titanium dioxide nanoparticles (TiO 2 NPs) have been widely employed in industrial applications, thus rising concern about their impact in the aquatic environment. In this study we investigated the chemical behaviour of TiO 2 NPs in the culture medium and its effect on the green alga Dunaliella tertiolecta, in terms of growth inhibition, oxidative stress, ROS (Reactive Oxygen Species) accumulation and chlorophyll content. In addition, the influence of exopolymeric substances (EPS) excreted by the microalgae on the stability of NPs has been evaluated. The physicochemical characterization showed a high propensity of TiO 2 NPs to form micrometric-sized aggregates within 30min, large enough to partially settle to the bottom of the test vessel. Indeed, an increasing amount of TiO 2 particles settled out with time, but the presence of EPS seemed to mitigate this behaviour in the first 6h of exposure where the main effects in D. tertiolecta were observed. TiO 2 NPs did not inhibit the 72-h growth rate of D. tertiolecta, nor affected the cellular chlorophyll concentration in the range 0.01-10mgL -1 . The time-course of ROS production showed an initial transient increase of ROS in TiO 2 NP-exposed algae compared to the control, concomitant with an enhancement of catalase activity. Interestingly, intracellular ROS was a small fraction of total ROS, the highest amount being extracellular. The occurrence of cell-mediated chemical transformations of TiO 2 NPs in the external medium, related to the presence of EPS, has been evaluated. Our results showed that carbohydrates were the major component of EPS, whereas proteins of medium molecular weight (20-80kDa) were preferentially bound to TiO 2 NPs, likely influencing their biological fate. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Effects of Sodium Nitrate and Mixotrophic Culture on Biomass and Lipid Production in Hypersaline Microalgae Dunaliella Viridis Teod

    Directory of Open Access Journals (Sweden)

    Mansour Kharati-Koupaei

    Full Text Available To access the potential application of Dunaliella viridis Teod. for biofuel production, the effects of culture media composition on biomass and lipid content of this microalgae were investigated. Measured at the 20 th day, sodium nitrate at 5.0 mM augmented biomass production by 26.5 percent compared to control (1 mM sodium nitrate. Total lipids expressed as µg mL-1 of culture also increased with increase in nitrate concentration up to 5.0 mM sodium nitrate, whereas when expressed on the per cell basis, total lipids stayed relatively constant at most of the tested nitrate concentrations except at 0.5 mM which was 31.4 percent higher compared to 1.0 mM nitrate. At 5.0 mM sodium nitrate, by using 20 g L-1 of glucose in mixotrophic culture of D. viridis, cell number augmented by 36.4 percent compared to the cultures with no added glucose. Llipid content per cell and per mL of culture was increased by 71.4 and 135.1 percent, respectively. Among plant hormones, 10-9 M indole-3- acetic acid (IAA plus 10 -8 M trans-zeatin riboside led to 22.8 percent higher biomass relative to control (without hormone and at 1.0 mM sodium nitrate. It is concluded that altering the growth conditions of D. viridis can lead to higher cell densities and higher lipids content which can be exploited for biofuel production.

  13. Molecular characterization of two microalgal strains in Egypt and investigation of the antimicrobial activity of their extracts

    Directory of Open Access Journals (Sweden)

    El Semary, NA.

    2013-01-01

    Full Text Available The emergence of new pathogens and the increasing drug-resistance of recognized ones pose a difficult challenge. One way that this challenge is being addressed is through the discovery of new cost-effective drug resources in the form of bioactive compounds. Algae represent a promising source of bioactive compounds in this regard. In the present research, we used molecular and phylogenetic analysis to isolate and identify two microalgal strains. We found that one strain belonged to the phylum chrysophyta and the other to the cyanobacteria. We also investigated the antimicrobial activity of some of the lipophilic extracts of the two microalgal strains. Several fractions showed high individual antimicrobial bioactivity against multidrug-resistant Salmonella sp., Citrobacter sp., Aspergillus niger and Aspergillus flavus. Fraction III from Poterioochromonas malhamensis showed the highest level of activity against two multidrug-resistant bacterial pathogens. The inhibition zone diameter was 1.4 cm for Salmonella and 1.4 cm for Citrobacter. Meanwhile, another lipophilic fraction from the cyanobacterium Synechocystis salina showed broad-spectrum bioactivity (inhibition zone diameter of 0.9 cm for Aspergillus niger, 1 cm for Citrobacter and 0.9 cm for Salmonella. One lipophilic fraction from Aphanizomenon showed antifungal bioactivity against Aspergillus niger and Aspergillus flavus, where the inhibition zone diameter was 1.1 cm and 1.0 cm, respectively. The study highlights the antimicrobial bioactivity of extracts from local microalgae and emphasizes the importance of carrying out screening programs for those microorganisms.

  14. First secondary metabolites from Herissantia crispa L (Brizicky) and the toxicity activity against Artemia salina Leach

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Danielly Albuquerque da; Matias, Wemerson Neves; Lima, Igara Oliveira; Xavier, Aline Lira; Costa, Vivian Bruna Machado; Diniz, Margareth de Fatima Formiga Melo; Agra, Maria de Fatima; Batista, Leonia Maria; Souza, Maria de Fatima Vanderlei de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica Prof. Delby Fernandes de Medeiros; Silva, Davi Antas e [Universidade Federal Rural de Pernambuco, Serra Talhada, PE (Brazil). Dept. de Quimica

    2009-07-01

    The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-{beta}-D-glucopyranoside, stigmasterol 3-O-{beta}-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides {beta}-sitosterol, kaempferol 3-O-{beta}-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-{alpha}-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, {sup 1}H and {sup 13}C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out. (author)

  15. El turismo de naturaleza en espacios naturales. El caso del parque regional de las Salinas y Arenales de San Pedro del Pinatar

    OpenAIRE

    Ballesteros Pelegrín, Gustavo Alfonso

    2014-01-01

    Los espacios naturales atraen a turistas que buscan el contacto con la naturaleza, surgiendo nuevos productos turísticos. Surgen, de este modo, nuevos productos turísticos. En la oferta de turismo de naturaleza del Parque Regional de las Salinas y Arenales de San Pedro del Pinatar destaca: deportes en la naturaleza, aventura y ecoturismo. Este último se divide en: turismo ornitológico y fotográfico, que junto al tradicional de sol y playa y de salud, se ve favorecido por su situación geográfi...

  16. Comparative Transcriptomic Analysis of the Response of Dunaliella acidophila (Chlorophyta) to Short-Term Cadmium and Chronic Natural Metal-Rich Water Exposures.

    Science.gov (United States)

    Puente-Sánchez, Fernando; Olsson, Sanna; Aguilera, Angeles

    2016-10-01

    Heavy metals are toxic compounds known to cause multiple and severe cellular damage. However, acidophilic extremophiles are able to cope with very high concentrations of heavy metals. This study investigated the stress response under natural environmental heavy metal concentrations in an acidophilic Dunaliella acidophila. We employed Illumina sequencing for a de novo transcriptome assembly and to identify changes in response to high cadmium concentrations and natural metal-rich water. The photosynthetic performance was also estimated by pulse amplitude-modulated (PAM) fluorescence. Transcriptomic analysis highlights a number of processes mainly related to a high constitutive expression of genes involved in oxidative stress and response to reactive oxygen species (ROS), even in the absence of heavy metals. Photosynthetic activity seems to be unaltered under short-term exposition to Cd and chronic exposure to natural metal-rich water, probably due to an increase in the synthesis of structural photosynthetic components preserving their functional integrity. An overrepresentation of Gene Ontology (GO) terms related to metabolic activities, transcription, and proteosomal catabolic process was observed when D. acidophila grew under chronic exposure to natural metal-rich water. GO terms involved in carbohydrate metabolic process, reticulum endoplasmic and Golgi bodies, were also specifically overrepresented in natural metal-rich water library suggesting an endoplasmic reticulum stress response.

  17. Crescimento e fitomassa da beterraba sob irrigação suplementar com água de diferentes concentrações salinas

    Directory of Open Access Journals (Sweden)

    Daniella Pereira dos Santos

    Full Text Available RESUMO O uso da água salina na agricultura é uma alternativa viável, tendo-se em vista o aumento da demanda de água doce. Objetivou-se, com este trabalho, avaliar o crescimento e a produção de fitomassa da beterraba, sob irrigação com água de diferentes concentrações salinas, em experimento em condição de campo, no Campus da Universidade Federal de Alagoas, em Arapiraca. Os tratamentos foram cinco níveis de condutividade elétrica (1,0; 2,0; 3,0; 4,0 e 5,0 dS m-1. O delineamento foi em blocos casualizados, com quatro repetições. O máximo rendimento da beterraba aos 27 dias após aplicação dos tratamentos salinos foi obtido com uma salinidade de 3,0 dS m-1, para as variáveis altura de planta (AP, diâmetro do caule (DC, comprimento da raiz (CR, fitomassa seca da parte aérea (FSPA e fitomassa seca total (FST. Aos 42 dias após aplicação dos tratamentos salinos, as variáveis fitomassa fresca da parte aérea (FFPA, fitomassa fresca da raiz (FFR, fitomassa fresca total (FFT, fitomassa seca da parte aérea (FSPA e fitomassa seca total (FST aumentaram com o aumento da salinidade da água. A chuva pode ter influenciado os resultados obtidos para as avaliações, realizadas aos 42 dias após aplicação dos tratamentos salinos.

  18. Changes in the Structure of the Microbial Community Associated with Nannochloropsis salina following Treatments with Antibiotics and Bioactive Compounds

    Science.gov (United States)

    Geng, Haifeng; Tran-Gyamfi, Mary B.; Lane, Todd W.; Sale, Kenneth L.; Yu, Eizadora T.

    2016-01-01

    Open microalgae cultures host a myriad of bacteria, creating a complex system of interacting species that influence algal growth and health. Many algal microbiota studies have been conducted to determine the relative importance of bacterial taxa to algal culture health and physiological states, but these studies have not characterized the interspecies relationships in the microbial communities. We subjected Nanochroloropsis salina cultures to multiple chemical treatments (antibiotics and quorum sensing compounds) and obtained dense time-series data on changes to the microbial community using 16S gene amplicon metagenomic sequencing (21,029,577 reads for 23 samples) to measure microbial taxa-taxa abundance correlations. Short-term treatment with antibiotics resulted in substantially larger shifts in the microbiota structure compared to changes observed following treatment with signaling compounds and glucose. We also calculated operational taxonomic unit (OTU) associations and generated OTU correlation networks to provide an overview of possible bacterial OTU interactions. This analysis identified five major cohesive modules of microbiota with similar co-abundance profiles across different chemical treatments. The Eigengenes of OTU modules were examined for correlation with different external treatment factors. This correlation-based analysis revealed that culture age (time) and treatment types have primary effects on forming network modules and shaping the community structure. Additional network analysis detected Alteromonadeles and Alphaproteobacteria as having the highest centrality, suggesting these species are “keystone” OTUs in the microbial community. Furthermore, we illustrated that the chemical tropodithietic acid, which is secreted by several species in the Alphaproteobacteria taxon, is able to drastically change the structure of the microbiota within 3 h. Taken together, these results provide valuable insights into the structure of the microbiota

  19. Caracterización de bacterias halófilas productoras de amilasas aisladas de las Salinas de San Blas en Junín

    Directory of Open Access Journals (Sweden)

    Pamela Elizabeth Canales Mormontoy

    2014-07-01

    Full Text Available Título en español: Caracterización de bacterias halófilas productoras de amilasas aisladas de las Salinas de San Blas en Junín Título en ingles: Characterization of halophilic bacteria producing amylase isolated from San Blas Salterns in Junin Título corto: Bacterias halófilas amilolíticas de las Salinas de San Blas Resumen:  El objetivo de este estudio fue caracterizar bacterias halófilas con actividad amilolítica provenientes de las Salinas de San Blas-Junín, ubicadas en los Andes peruanos aproximadamente a 4100 m de altitud. Este estudio se realizó con 34 bacterias aisladas de muestras de suelos las cuales se cultivaron en agar agua de sales (SW 5 % conteniendo extracto de levadura 0,5 % y almidón 1 %. El 41 % de bacterias mostró la capacidad de hidrolizar almidón, éstas fueron caracterizadas mediante pruebas fisiológicas y bioquímicas convencionales. Tres bacterias fueron Gram-negativas y once Gram-positivas. El 21 % (3/14 creció en un amplio rango de concentración de sales, entre 5 y 20 %. El 14 % (2/14 de las bacterias presentó actividad lipolítica, proteolítica y nucleolítica, y el 29 % (4/14, presentó actividad proteolítica y nucleolítica. Las bacterias se identificaron mediante los perfiles de restricción de los genes ribosómicos 16S amplificados, las enzimas usadas fueron Hae III, BstU I, Hinf I y Cfo I. Los genes ribosómicos 16S de siete bacterias que presentaron perfiles de ADN diferentes se amplificaron, secuenciaron y analizaron mediante programas bioinformáticos. Del análisis fenotípico y molecular de las 14 bacterias amilolíticas se obtuvieron dos grupos, uno perteneciente al género Halomonas (3 y el otro, al género Bacillus (11. Las bacterias amilolíticas caracterizadas podrían ser de potencial uso a nivel industrial.  Palabras clave: Salinas de San Blas, amilasas, genes ribosómicos 16S, ARDRA, Bacillus, Halomonas. Abstract: The aim of this study was to characterize halophilic

  20. Encapsulación de moléculas pequeñas mediante la precipitación salina de poliuretanos catioméricos

    OpenAIRE

    Fernández d’Arlas, Borja; Corcuera, María Ángeles; Eceiza, Arantxa

    2015-01-01

    En este trabajo se estudia un copolímero de poliuretano catiomérico (PU) con alta proporción de uretano como agente encapsulante de fármacos modelos (FM) mediante la encapsulación inducida por precipitación salina del PU y FM a pH < pI del PU. Mediante espectroscopia UV-Vis se ha estimado el porcentaje de encapsulación de varios FMs proponiéndose un modelo semi-empírico para determinar la distribución observada en las eficiencias de encapsulación, E, en función de su volumen molar...

  1. Atributos biológicos de dos suelos de Quibor con aplicación de abono orgánico y soluciones salinas

    OpenAIRE

    Mendoza, Betty; Florentino, Adriana; Hernández-Hernández, Rosa Mary; Aciego, Juan; Torres, Duilio; Vera, Elena

    2013-01-01

    La evaluación del efecto de la aplicación de abono orgánico y soluciones salinas sobre los atributos biológicos de suelos de Quibor estado Lara, Venezuela, uno bajo manejo convencional (CV) y otro bajo manejo conservacionista (CS), se realizó mediante un ensayo de invernadero. Se utilizaron tres dosis de materia orgánica (MO): 0, 15 y 30 Mg ha-1 y cuatro soluciones de riego (SR): testigo con agua (T), sulfato de calcio (SC), cloruro de sodio (CN) y la mezcla de sulfato de calcio con cloruro d...

  2. Transcriptome sequencing and annotation of the microalgae Dunaliella tertiolecta: Pathway description and gene discovery for production of next-generation biofuels

    Directory of Open Access Journals (Sweden)

    Bibby Kyle

    2011-03-01

    Full Text Available Abstract Background Biodiesel or ethanol derived from lipids or starch produced by microalgae may overcome many of the sustainability challenges previously ascribed to petroleum-based fuels and first generation plant-based biofuels. The paucity of microalgae genome sequences, however, limits gene-based biofuel feedstock optimization studies. Here we describe the sequencing and de novo transcriptome assembly for the non-model microalgae species, Dunaliella tertiolecta, and identify pathways and genes of importance related to biofuel production. Results Next generation DNA pyrosequencing technology applied to D. tertiolecta transcripts produced 1,363,336 high quality reads with an average length of 400 bases. Following quality and size trimming, ~ 45% of the high quality reads were assembled into 33,307 isotigs with a 31-fold coverage and 376,482 singletons. Assembled sequences and singletons were subjected to BLAST similarity searches and annotated with Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG orthology (KO identifiers. These analyses identified the majority of lipid and starch biosynthesis and catabolism pathways in D. tertiolecta. Conclusions The construction of metabolic pathways involved in the biosynthesis and catabolism of fatty acids, triacylglycrols, and starch in D. tertiolecta as well as the assembled transcriptome provide a foundation for the molecular genetics and functional genomics required to direct metabolic engineering efforts that seek to enhance the quantity and character of microalgae-based biofuel feedstock.

  3. Are known cyanotoxins involved in the toxicity of picoplanktonic and filamentous North Atlantic marine cyanobacteria?

    Science.gov (United States)

    Frazão, Bárbara; Martins, Rosário; Vasconcelos, Vitor

    2010-06-21

    Eight marine cyanobacteria strains of the genera Cyanobium, Leptolyngbya, Oscillatoria, Phormidium, and Synechococcus were isolated from rocky beaches along the Atlantic Portuguese central coast and tested for ecotoxicity. Strains were identified by morphological characteristics and by the amplification and sequentiation of the 16S rDNA. Bioactivity of dichloromethane, methanol and aqueous extracts was assessed by the Artemia salina bioassay. Peptide toxin production was screened by matrix assisted laser desorption/ionization time of flight mass spectrometry. Molecular analysis of the genes involved in the production of known cyanotoxins such as microcystins, nodularins and cylindrospermopsin was also performed. Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones. Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain. The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

  4. Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762 (Culicidae and Artemia salina (Artemidae

    Directory of Open Access Journals (Sweden)

    Eduardo José de Arruda

    2011-06-01

    Full Text Available This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24 h for Na2[EDTA-Cu(II] and total mortality in 72 h for SAP-Na2[EDTA-Cu(II].

  5. Strain selection, biomass to biofuel conversion, and resource colocation have strong impacts on the economic performance of algae cultivation sites

    Directory of Open Access Journals (Sweden)

    Erik R. Venteris

    2014-09-01

    Full Text Available Decisions involving strain selection, biomass to biofuel technology, and the location of cultivation facilities can strongly influence the economic viability of an algae-based biofuel enterprise. We summarize our past results in a new analysis to explore the relative economic impact of these design choices. Our growth model is used to predict average biomass production for two saline strains (Nannocloropsis salina, Arthrospira sp., one fresh to brackish strain (Chlorella sp., DOE strain 1412, and one freshwater strain (order Sphaeropleales. Biomass to biofuel conversion is compared between lipid extraction (LE and hydrothermal liquefaction (HTL technologies. National-scale models of water, CO2 (as flue gas, land acquisition, site leveling, construction of connecting roads, and transport of HTL oil to existing refineries are used in conjunction with estimates of fuel value (from HTL to prioritize and select from 88,692 unit farms (UF, 405 ha in pond area, a number sufficient to produce 136E+9 L yr-1 of renewable diesel (36 billion gallons yr-1. Strain selection and choice of conversion technology have large economic impacts, with differences between combinations of strains and biomass to biofuel technologies being up to $10 million dollars yr-1 UF-1. Results based on the most productive strain, HTL-based fuel conversion, and resource costs show that the economic potential between geographic locations within the selection can differ by up to $4 million yr-1 UF-1, with 1.8 BGY of production possible from the most cost-effective sites. The local spatial variability in site rank is extreme, with very high and low sites within 10s of km of each other. Colocation with flue gas sources has a strong influence on rank, but the most costly resource component varies from site to site. The highest rank UFs are located predominantly in Florida and Texas, but most states south of 37°N latitude contain promising locations.

  6. Strain selection, biomass to biofuel conversion, and resource colocation have strong impacts on the economic performance of algae cultivation sites

    Energy Technology Data Exchange (ETDEWEB)

    Venteris, Erik R.; Wigmosta, Mark S.; Coleman, Andre M.; Skaggs, Richard

    2014-09-16

    Decisions involving strain selection, biomass to biofuel technology, and the location of cultivation facilities can strongly influence the economic viability of an algae-based biofuel enterprise. In this contribution we summarize our past results in a new analysis to explore the relative economic impact of these design choices. We present strain-specific growth model results from two saline strains (Nannocloropsis salina, Arthrospira sp.), a fresh to brackish strain (Chlorella sp., DOE strain 1412), and a freshwater strain of the order Sphaeropleales. Biomass to biofuel conversion is compared between lipid extraction (LE) and hydrothermal liquefaction (HTL) technologies. National-scale models of water, CO2 (as flue gas), land acquisition, site leveling, construction of connecting roads, and transport of HTL oil to existing refineries are used in conjunction with estimates of fuel value (from HTL) to prioritize and select from 88,692 unit farms (UF, 405 ha in pond area), a number sufficient to produce 136E+9 L yr-1 of renewable diesel (36 billion gallons yr-1, BGY). Strain selection and choice of conversion technology have large economic impacts, with differences between combinations of strains and biomass to biofuel technologies being up to $10 million dollars yr-1 UF-1. Results based on the most productive species, HTL-based fuel conversion, and resource costs show that the economic potential between geographic locations within the selection can differ by up to $4 million yr-1 UF-1, with 2.0 BGY of production possible from the most cost-effective sites. The local spatial variability in site rank is extreme, with very high and low rank sites within 10s of km of each other. Colocation with flue gas sources has a strong influence on site rank, but the most costly resource component varies from site to site. The highest rank sites are located predominantly in Florida and Texas, but most states south of 37°N latitude contain promising locations. Keywords: algae

  7. Strain Selection, Biomass to Biofuel Conversion, and Resource Colocation have Strong Impacts on the Economic Performance of Algae Cultivation Sites

    Energy Technology Data Exchange (ETDEWEB)

    Venteris, Erik R., E-mail: erik.venteris@pnl.gov; Wigmosta, Mark S.; Coleman, Andre M.; Skaggs, Richard L. [Pacific Northwest National Laboratory, Richland, WA (United States)

    2014-09-16

    Decisions involving strain selection, biomass to biofuel technology, and the location of cultivation facilities can strongly influence the economic viability of an algae-based biofuel enterprise. We summarize our past results in a new analysis to explore the relative economic impact of these design choices. Our growth model is used to predict average biomass production for two saline strains (Nannochloropsis salina and Arthrospira sp.), one fresh to brackish strain (Chlorella sp., DOE strain 1412), and one freshwater strain (order Sphaeropleales). Biomass to biofuel conversion is compared between lipid extraction and hydrothermal liquefaction (HTL) technologies. National-scale models of water, CO{sub 2} (as flue gas), land acquisition, site leveling, construction of connecting roads, and transport of HTL oil to existing refineries are used in conjunction with estimates of fuel value (from HTL) to prioritize and select from 88,692 unit farms (UF, 405 ha in pond area), a number sufficient to produce 136E + 9 L year{sup −1} of renewable diesel [36 billion gallons year{sup −1} (BGY)]. Strain selection and choice of conversion technology have large economic impacts, with differences between combinations of strains and biomass to biofuel technologies being up to $10 million year{sup −1} UF{sup −1}. Results based on the most productive strain, HTL-based fuel conversion, and resource costs show that the economic potential between geographic locations within the selection can differ by up to 4 million year{sup −1} UF{sup −1}, with 1.8 BGY of production possible from the most cost-effective sites. The local spatial variability in site rank is extreme, with very high and low sites within 10 kms of each other. Colocation with flue gas sources has a strong influence on rank, but the most costly resource component varies from site to site. The highest rank UFs are located predominantly in Florida and Texas, but most states south of 37°N latitude contain promising

  8. Tratamiento del prolapso rectal en la infancia con infiltración de solución salina al 16,5 %

    Directory of Open Access Journals (Sweden)

    Carlos Ramírez Pérez

    Full Text Available Introducción: cuando falla el tratamiento médico conservador en los pacientes pediátricos con prolapso rectal se impone la infiltración perirrectal con sustancias irritantes. En la década de los 90 esas infiltraciones en nuestro centro se hacían con glicerina, pero escaseó en el mercado, y ante tal problema, se buscó otro agente infiltrante alternativo. En el presente trabajo se describe la experiencia con la utilización de solución salina al 16,5 %. Métodos: se realizó un estudio de intervención, longitudinal, prospectivo, experimental, del tipo ensayo clínico no controlado. Consta de una segunda parte en la que se utilizó la aleatorización con un grupo control para la validación. El universo estuvo constituido por 27 pacientes y la muestra, por 16 pacientes con prolapso rectal, que fueron atendidos en el servicio de gastroenterología del Hospital Pediátrico Provincial de Holguín en el quinquenio 2003-2007. Las variables desarrolladas fueron: concentración idónea para el tratamiento, cantidad de sustancia a infiltrar, complicaciones, recurrencia, número de infiltraciones y curación al año o más. Los resultados se exponen en forma de tablas porcentuales. Resultados: la eficacia con la utilización de solución salina al 16,5 % fue del 100 %, todos los pacientes curaron, y ninguno presentó recurrencia, por lo que no fueron necesarias 2 o más sesiones de tratamiento. Se comentó de un niño que, luego de fallar la infiltración con leche materna en primera opción y fallido también el cerclaje, finalmente resolvió con este método. Las complicaciones fueron relativamente pocas (18,9 %: un absceso, una celulitis y una retención urinaria con necesidad de sondaje durante 2 semanas, sin secuelas posteriores. Se realizó aleatorización con igual número de pacientes en quienes se usó la glicerina, los resultados del uso de ambas sustancias fueron muy parecidos, y el número de complicaciones fue ligeramente mayor en el

  9. Estudio de caracterización de emprendedores de la Parroquia Salinas de la Provincia de Bolívar - Ecuador

    Directory of Open Access Journals (Sweden)

    Jorge Goyes Noboa

    2016-09-01

    Salinas de Guaranda. Se han identificado variables y factores sociales, económicos, de financiamiento, organizacionales, estructuras administrativas, económicas, cultura organizacional, formas asociativas, motivación para crear negocios, estructuras de negocios predominantes que impulsan la economía social y solidaria presente en la zona. El mayor número de emprendimientos está ligado directa e indirectamente (66% de negocios a las organizaciones sociales y fundaciones salineras, son negocios relativamente jóvenes (menos de 10 años de existencia que han surgido por la necesidad de generar actividades económicas que apoyen al ingreso familiar y comunitario, con lo que afianza el modelo de desarrollo social vigente.

  10. Regulatory Project Manager for Salina and Permian Basins for the NWTS [National Waste Terminal Storage] Program: Final techical report

    International Nuclear Information System (INIS)

    1986-12-01

    The identification of candidate sites for nuclear waste repositories involves geological and environmental studies to characterize potential sites. These investigations include the collection and analysis of detailed geological and environmental data and comparison of the data against predetermined site performance criteria, i.e., geologic characteristics, environmental protection, and socioeconomic impacts. The work summarized in this final technical report encompasses mainly ''environmental characterization'' studies in the Permian Basin in the Texas Panhandle during the period of 1977-86; in the earlier phase of the contract, regional environmental work was also done in the Salina Basin (1977-79) and certain licensing support activities and safety analyses were conducted (1977-82). Considerable regulatory support work was also performed during 1986. 9 figs., 2 tabs

  11. Isolasi Senyawa Aktif Ekstrak Etanol Biji Alpukat (Persea americana dan Uji Toksisitas Terhadap Artemia Salina Leach

    Directory of Open Access Journals (Sweden)

    Andi Nur Fitriani Abubakar

    2014-07-01

    Full Text Available Avocado seed (Persea americana is recognized as one of medicinal plants. It contains several secondary metabolites, which have toxic activity. However, efforts to identify active compounds from avocado seeds (Persea americana are still relatively rare. Therefore, isolation and toxicity assay have been conducted foward the active compound of avocado seed. Maceration one kilogram of seed dried powder by ethanol obtained 49,7464 gram extract. Separation of etanol extract by column chromatography generated 0,0698 grams of pure white needle crytal, which is positively triterpenoid based on Lieberman-Buchard test. In addition, infrared spectrum showed the existence of OH, C=C, C-C, C=O, -C-H, -CH3,-CH2 and C-O stretch, which support the presumed compound. The result of toxicity test on Artemia salina Leach showed that the extract, fraction and pure isolates of the etanol extract are toxic with LC50 values 13,274 g/mL; 9,528 g/mL and 8,128 g/mL, respectively.

  12. Emergência e crescimento inicial de plântulas de albízia submetidas à irrigação com água salina

    Directory of Open Access Journals (Sweden)

    Mayky F. P. de Lima

    2015-02-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o efeito de diferentes concentrações de sais na água de irrigação sob a emergência e o crescimento inicial de plântulas de albízia (Albizia lebbeck (L. Benth.. O experimento foi desenvolvido em casa de vegetação do departamento de Ciências Vegetais da Universidade Federal Rural do Semiárido, Mossoró, RN, usando-se o delineamento inteiramente casualizado, com seis tratamentos e quatro repetições, com 24 sementes em cada parcela. Os tratamentos foram constituídos das concentrações salinas 0,68 (água de abastecimento; 1,5; 3,0; 4,5; 6,0 e 7,5 dS m-1, obtidas através da adição de NaCl em água. As variáveis avaliadas foram: porcentagem de emergência de plântulas, índice de velocidade de emergência, comprimento da parte aérea, comprimento de raiz, número de folíolos, condutividade elétrica acumulada do substrato, índice de conteúdo de clorofila, massa seca da raiz, do caule, das folhas e total. O aumento da salinidade na água de irrigação interfere negativamente na emergência e no crescimento inicial de plântulas de albízia, sendo recomendado água com concentração salina até 1,5 dS m-1, caracterizando esta espécie como glicófita, sensível à salinidade.

  13. Aproximações sobre prescrições e práticas corporais nos Grupos escolares de Pirapora, Januária e Salinas: a educação dos corpos sertanejos - (1906-1927 * Approaches about prescriptions and corporal practices in schools in Pirapora, Januária and Salinas

    Directory of Open Access Journals (Sweden)

    ELISÂNGELA CHAVES

    2012-05-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:14.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-fareast-language:EN-US;} O texto analisa a proposta da educação corporal de grupos escolares localizados no norte de Minas Gerais no período de 1906 a 1927, notadamente nos municípios de Pirapora, Januária e Salinas. A pesquisa tomou como fonte principal relatos orais e demais documentos diretamente relacionados com a memória escolar para compreender como as atividades físicas foram percebidas como modeladoras de hábitos e atitudes, em um momento histórico em que Brasil prezava pelo discurso modernizador. Palavras-chave: Educação corporal – Memória – Desenvolvimento.   Abstract: The text analyses the proposal of the corporal education in schools in the north of Minas Gerais during 1906 and 1927, especially in Pirapora, januária and Salinas. As main source, the research made use of oral reports and other documents directly related to school memory to understand how physical activities were realized as habit and attitude-forming, in a historic moment in which Brazil used to cherish the modernizing speech. Keywords: Corporal education – Memory – Depevolpment.

  14. Efeito alelopático e toxicidade frente à Artemia salina Leach dos extatos do fruto de Euterpe edulis Martius Allelopathic effects and toxicity against Artemia salina Leach of extracts of the fruit of Euterpe edulis Martius

    Directory of Open Access Journals (Sweden)

    Cristina Peitz de Lima

    2011-06-01

    Full Text Available Alelopatia é um processo envolvendo metabólitos secundários produzidos por plantas que infl uenciam o crescimento e desenvolvimento de sistemas agrícolas. Devido à toxicidade dos herbicidas sintéticos para o meio ambiente e para a saúde humana tem-se aumentado o interesse na exploração da alelopatia como uma alternativa para o controle de plantas daninhas. O presente trabalho avaliou efeito dos extratos dos frutos de Euterpe edulis Martius sobre o desenvolvimento de cipselas e plântulas de Lactuca sativa Linné, foram determinados o índice de velocidade de germinação, o crescimento da radícula e do hipocótilo. Para a avaliação da toxicidade dos extratos foi realizado o ensaio de toxicidade frente ao microcrustáceo Artemia salina Leach determinando-se a CL50 e percentual de mortalidade. A fração remanescente demonstrou efeito alelopático, pois todas as concentrações alteraram os valores do índice de velocidade de germinação e as concentrações de 0,2 e 0,4 mg inibiram tanto o crescimento da radícula quanto o crescimento do hipocótilo. No ensaio de toxicidade todos os extratos apresentaram CL50 superior a 1000 ppm e 0% de mortalidade das artemias, indicando a não toxicidade dos extratos.Allelopathy is a process involving secondary metabolites produced by plants that influence growth and development of agricultural systems. Because of the toxicity of synthetic herbicides to the environment and human health, there has been increased interest in exploiting allelopathy as an alternative for weed control. This study evaluated the eff ect of extracts of Euterpe edulis Martius fruits on the development of cypselae and seedlings of Lactuca sativa Linné; the germination speed index, radicle and hypocotyl growth were determined. To evaluate the toxicity of the extracts the toxicity test against Artemia salina Leach was used, where the LC50 and mortality rate were determined. Th e remaining fraction showed allelopathic effect

  15. Un carnaval para el yo lésbico: Los cuentos de Gilda Salinas

    Directory of Open Access Journals (Sweden)

    Elena Madrigal

    2011-01-01

    Full Text Available Gilda Salinas rompe las unidades cuentísticas tradicionales al hacer de cada texto de Del destete al desempance. Cuentos lésbicos y un colado un episodio en la vida de una lesbiana que, con “voz propia”, narra sus peripecias nocturnas por la ciudad de México, de los años setenta a la actualidad. Al ubicar las acciones en sitios de diversión lésbica que no existen más, la voz, cual cronista, rescata un ámbito de la vida homosexual a la vez que fija bromas y códigos lingüísticos que por su origen oral hubieran corrido el riesgo de perderse con las generaciones que los animaron. Sus estrategias carnavalizan el tema lésbico a la vez que legitiman la validez de las búsquedas expresivas y de comportamiento del ser lesbiana en un tiempo y en un lugar. Su aportación en los planos del género literario y de la formación de constantes en la narrativa homosexual mexicana indudablemente enriquece los medios expresivos, la visibilidad, la diversidad, las vidas y las historias de la y las lesbianas.

  16. [Immunocytochemical studies on the phase of differentiation of hatching gland cells in brine shrimp, Artemia salina].

    Science.gov (United States)

    Li, Ling; Fan, Ting Jun; Wang, Xiao Feng; Cong, Ri Shan; Yu, Qiu Tao; Zhong, Qi Wang

    2004-04-01

    Hatching enzyme (HE), synthesized in hatching gland cells (HGCs), plays vital roles in animal hatching. Immunocytochemical techniques employing anti-GST-UVS.2 antiserum, prepared from Xenopus HE and with specificity to brine shrimp HE, were first used to investigate the differentiation and variability of hatching gland cells (HGCs) in the hatching process of embryos of brine shrimp, Artemia salina, in this study. HGCs with immunoreactivity to anti-GST-UVS.2 antiserum were identified, for the first time, in brine shrimp embryos during hatching process. Immunocytochemical staining results showed that, (1) HE-positive immunoreactivity is really specific to Artemia HE, and its appearance and disappearance are closely correlated with the hatching process of Artemia salina. (2) Artemia HGCs, first appeared in embryos 5 hours before hatching and disappeared 4 hours after hatching, were also a transient type of cells, with an existence period of 9 hours. (3) The head portion of Artemia embryo is probably the initial position of HE secretion, and likely to be the main position of HE secretion as well. The detailed process and mechanism need to be studied. (4) The appearance of HGCs is in a synchronous mode from places all over the embryos, and their disappearance is also in a synchronous mode. (5) The number of HGCs increased gradually along with embryo development process and reached a maximum number at hatching. Contrarily, the number of HGCs decreased gradually after hatching, and HGCs disappeared 5 hours after hatching. However, the intensity of HE-positive reaction was almost at the same level at the period of HGCs'presence. (6) Artemia HGCs were distributed throughout the body of embryos at all time during their presence. Therefore, it can concluded that Artemia HGCs, as a transient type of cells, first appeared in embryos 4 hours before hatching and disappeared in embryos 5 hours after hatching, and with distinguished patterns of appearance, disappearance and

  17. «Cada página lograda es una letra al más allá». Estudio de la correspondencia Américo Castro-Pedro Salinas

    OpenAIRE

    Zamarreño Méndez, Fabio

    2016-01-01

    Este trabajo explora la correspondencia entre Pedro Salinas y Américo Castro a partir de una edición, que, a causa de la legislación vigente respecto de los derechos de autor, no puede ser publicada. Por tanto, aquí encontramos el estudio introductorio, que analiza ese epistolario desde todas las perspectivas: comenzando con un repaso teórico del subgénero epistolar, pronto se explican las dificultades en torno a la reconstrucción cronológica del epistolario. Temáticamente, se analizan difere...

  18. El turismo de naturaleza en espacios naturales. El caso del Parque Regional de las Salinas y Arenales de San Pedro del Pinatar

    Directory of Open Access Journals (Sweden)

    Gustavo A. Ballesteros Pelegrín

    2014-01-01

    Full Text Available Los espacios naturales atraen a turistas que buscan el contacto con la naturaleza, surgiendo nuevos productos turísticos. Surgen, de este modo, nuevos productos turísticos. En la oferta de turismo de naturaleza del Parque Regional de las Salinas y Arenales de San Pedro del Pinatar destaca: deportes en la naturaleza, aventura y ecoturismo. Este último se divide en: turismo ornitológico y fotográfico, que junto al tradicional de sol y playa y de salud, se ve favorecido por su situación geográfica, condiciones naturales y amplia oferta hotelera. Sin embargo, el turismo cultural basado en la tradición salinera y pesquera no ha sido desarrollado.

  19. Geology of the Delta, Escalante, Price, Richfield, and Salina 10 x 20 quadrangles, Utah

    International Nuclear Information System (INIS)

    Thayer, P.A.

    1981-11-01

    The National Uranium Resource Evaluation (NURE) program was established to evaluate domestic uranium resources in the continental United States and to identify areas favorable for uranium exploration. The Grand Junction Office of the Department of Energy is responsible for administering the program. The Savannah River Laboratory (SRL) is responsible for hydrogeochemical and stream-sediment reconnaissance (HSSR) of 3.9 million km 2 (1,500,000 mi 2 ) in 37 eastern and western states. This document provides geologic and mineral resources reports for the Delta, Escalante, Price, Richfield, and Salina 1 0 x 2 0 National Topographic Map Series quadrangles, Utah. The purpose of these reports is to provide background geologic and mineral resources information to aid in the interpretation of NURE geochemical reconnaissance data. Except for the Escalante Quadrangle, each report is accompanied by a geologic map and a mineral locality map (Plates 1-8, in pocket). The US Geological Survey previously published a 1 0 x 2 0 geologic map of the Escalante Quadrangle and described the uranium deposits in the area (Hackman and Wyant, 1973). NURE hydrogeochemical and stream-sediment reconnaissance data for these quadrangles have been issued previously in some of the reports included in the references

  20. Estudio del comercio electrónico como estrategia de negocios dentro de las empresas que brindan servicios de hospedaje en el Cantón Salinas, provincia de Santa Elena.

    OpenAIRE

    Mateo López, Blanca Annabell

    2015-01-01

    El presente trabajo tiene como objetivo analizar los mecanismos de promoción y comercialización, que utilizan los establecimientos que brindan servicios de hospedaje en Salinas, identificando los medios de comunicación que manejan para potenciar sus negocios. Al conocer que a nivel mundial existen varias estrategias soportadas en medios digitales por parte de los hoteles, se ha determinado la necesidad de los empresarios hoteleros de tener en sus empresas una página web, o mejoras...

  1. Growth of mussels Mytilus edulis at algal (Rhodomonas salina) concentrations below and above saturation level for reduced filtration rate

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Pleissner, Daniel; Larsen, Poul Scheel

    2013-01-01

    Average filtration and growth rates of groups of juvenile Mytilus edulis (n =2545 of 22-35 mm shell length) were measured at different concentrations of an algal cell monoculture in 9 laboratory experiments of duration 14-30 days, 4 experiments below and 5 above the limit of incipient saturation...... concentration (Csat ≈ 6000-7000 Rhodomonas salina cells ml-1). From a nearly constant filtration rate (F ≈ 30 ml min-1 for a 30 mm shell length) at measured algal concentrations below Csat the steady-state filtration rate decreased approximately as 1/C for increasing algal concentrations (C) above Csat...... is exceeded and then as partial valve closure and reduced filtration and growth rates along with production of pseudofaeces. A survey of naturally occurring phytoplankton biomass in the sea shows that this is generally below Csat except for the short spring bloom periods; hence mussels generally feed...

  2. Cell survival after UV radiation stress in the unicellular chlorophyte Dunaliella tertiolecta is mediated by DNA repair and MAPK phosphorylation.

    Science.gov (United States)

    García-Gómez, Candela; Parages, María L; Jiménez, Carlos; Palma, Armando; Mata, M Teresa; Segovia, María

    2012-09-01

    Ultraviolet radiation (UVR) induces damage in a variety of organisms, and cells may adapt by developing repair or tolerance mechanisms to counteract such damage; otherwise, the cellular fate is cell death. Here, the effect of UVR-induced cell damage and the associated signalling and repair mechanisms by which cells are able to survive was studied in Dunaliella tertiolecta. UVR did not cause cell death, as shown by the absence of SYTOX Green-positive labelling cells. Ultrastructure analysis by transmission electron microscopy demonstrated that the cells were alive but were subjected to morphological changes such as starch accumulation, chromatin disaggregation, and chloroplast degradation. This behaviour paralleled a decrease in F(v)/F(m) and the formation of cyclobutane-pyrimidine dimers, showing a 10-fold increase at the end of the time course. There was a high accumulation of the repressor of transcriptional gene silencing (ROS1), as well as the cell proliferation nuclear antigen (PCNA) in UVR-treated cells, revealing activation of DNA repair mechanisms. The degree of phosphorylation of c-Jun N-terminal kinase (JNK) and p38-like mitogen-activated protein kinases was higher in UVR-exposed cells; however, the opposite occurred with the phosphorylated extracellular signal-regulated kinase (ERK). This confirmed that both JNK and p38 need to be phosphorylated to trigger the stress response, as well as the fact that cell division is arrested when an ERK is dephosphorylated. In parallel, both DEVDase and WEHDase caspase-like enzymatic activities were active even though the cells were not dead, suggesting that these proteases must be considered within a wider frame of stress proteins, rather than specifically being involved in cell death in these organisms.

  3. Trocas gasosas e conteúdo de carboidratos e compostos nitrogenados em pinhão-manso irrigado com águas residuária e salina

    Directory of Open Access Journals (Sweden)

    Antonio Evami Cavalcante Sousa

    2012-10-01

    Full Text Available O objetivo deste trabalho foi avaliar alterações nas trocas gasosas e nos conteúdos de carboidratos e compostos nitrogenados, em pinhão-manso (Jatropha curcas irrigado com águas residuária e salina. Empregou-se o delineamento em blocos ao acaso, com quatro tratamentos e quatro repetições: irrigação plena com água de abastecimento a 0,6 dS m-1 (controle; irrigação plena com água salinizada a 2,4 dS m-1 (SAL; e irrigação com água residuária de esgoto, plena (R100 e a 50% da capacidade de campo (R50. O tratamento R50 reduziu fortemente as trocas gasosas e a área foliar, comparado ao controle, seguido pelos tratamentos SAL e R100. A redução na fotossíntese diminuiu o nível de sacarose nas folhas, nos quatro tratamentos. Os teores de açúcares solúveis aumentaram nos tratamentos R50, SAL e R100, enquanto o conteúdo de amido permaneceu praticamente inalterado. Os conteúdos de prolina e glicina betaína aumentaram nos três tratamentos, mas a última foi mais importante, em termos quantitativos, como protetor celular e osmótico. A irrigação plena com água residuária induz efeitos similares aos causados pela irrigação com água salina. A irrigação limitada com água residuária causa estresse agudo às plantas, provavelmente pela combinação de deficiência hídrica e acúmulo de solutos no solo.

  4. Corrosividade Causada por Soluções Salinas Empregadas na Estabilização Dimensional da Madeira

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2017-08-01

    Full Text Available RESUMO Objetivou-se avaliar a corrosividade de soluções salinas antes e depois de sua impregnação na madeira. Soluções com 5% de concentração de cloreto de lítio, carbonato de sódio, sulfato de magnésio, sulfato de zinco e sulfato de cobre II foram mantidas durante 6 horas, a 25 °C, 45 °C e 100 °C em contato com amostras de 1,25 cm × 0,1 cm × 7,5 cm (largura × espessura × comprimento produzidas com chapas de aço carbono antes e depois de seu contato com amostras de madeira de Corymbia torelliana e Eucalyptus cloeziana. Não se observou efeito da temperatura na corrosão das soluções puras. Depois do contato com a madeira houve incremento da corrosividade para as soluções de sulfato de zinco e de cobre II. O sulfato de cobre II ocasionou a maior perda de massa nas chapas, não sendo recomendado seu contato com superfícies metálicas, como usinas de tratamento e câmaras de secagem de madeira.

  5. In vivo and in vitro antiplasmodial activities of some plants traditionally used in Guatemala against malaria.

    Science.gov (United States)

    Franssen, F F; Smeijsters, L J; Berger, I; Medinilla Aldana, B E

    1997-07-01

    We present an evaluation of the antiplasmodial and cytotoxic effects of four plants commonly used in Guatemalan folk medicine against malaria. Methanol extracts of Simarouba glauca D. C., Sansevieria guineensis Willd, Croton guatemalensis Lotsy, and Neurolaena lobata (L.)R.Br. significantly reduced parasitemias in Plasmodium berghei-infected mice. Dichloromethane fractions were screened for their cytotoxicities on Artemia salina (brine shrimp) larvae, and 50% inhibitory concentrations were determined for Plasmodium falciparum in in vitro cultures. Both chloroquine-susceptible and -resistant strains of P. falciparum were significantly inhibited by these extracts. Of all dichloromethane extracts, only the S. glauca cortex extract was considered to be toxic to nauplii of A. salina in the brine shrimp test.

  6. Variabilidade sazonal dos constituintes da própolis vermelha e bioatividade em Artermia salina

    Directory of Open Access Journals (Sweden)

    Lívio César Cunha Nunes

    Full Text Available A própolis é uma substância resinosa coletada pelas abelhas de diversas partes das plantas. Sua composição depende da época, vegetação e local de coleta. Apresenta diversas atividades biológicas como antimicrobiana, antioxidante, antitumoral, dentre outras. Foi realizado estudo da variabilidade sazonal, nos meses de fevereiro, junho e outubro de 2006, dos constituintes voláteis da própolis vermelha de Pernambuco através da extração por headspace dinâmico e identificação por cromatografia gasosa acoplada com espectrometria de massas (CG-EM. Foram identificados 34 constituintes voláteis, sendo monoterpenos e monoterpenóides, sesquiterpenos e sesquiterpenóides, fenilpropanóides, aldeídos, cetonas e η-alcanos. Os constituintes majoritários foram o trans-anetol, α-copaeno e o metil cis-isoeugenol. Também foi realizado o perfil fitoquímico por cromatografia em camada delgada (CCD, através da qual os constituintes fenólicos foram identificados como majoritários. Com o extrato bruto metanólico da própolis, realizou-se o ensaio de letalidade em Artemia salina, que demonstrou DL50 de 18,9 µg/mL, sugerindo uma possível atividade antitumoral.

  7. Rainfall leaching is critical for long-term use of recycled water in the Salinas Valley

    Directory of Open Access Journals (Sweden)

    Belinda E. Platts

    2014-07-01

    Full Text Available In 1998, Monterey County Water Recycling Projects began delivering water to 12,000 acres in the northern Salinas Valley. Two years later, an ongoing study began assessing the effects of the recycled water on soil salinity. Eight sites are receiving recycled water and a control site is receiving only well water. In data collected from 2000 to 2012, soil salinity of the 36-inch-deep profile was on average approximately double that of the applied water, suggesting significant leaching from applied water (irrigation or rainfall. In this study, we investigated some of the soil water hydrology factors possibly controlling the soil salinity results. Using soil water balance modeling, we found that rainfall had more effect on soil salinity than did leaching from irrigation. Increasing applied water usually only correlated significantly with soil salinity parameters in the shallow soil profile (1 to 12 inches depth and at 24 to 36 inches at sites receiving fairly undiluted recycled water. Winter rains, though, had a critical effect. Increasing rainfall depths were significantly correlated with decreasing soil salinity of the shallow soil at all test sites, though this effect also diminished with increased soil depth. When applied water had high salinity levels, winter rainfall in this area was inadequate to prevent soil salinity from increasing.

  8. Estimation of chromophoric dissolved organic matter (CDOM) and photosynthetic activity of estuarine phytoplankton using a multiple-fixed-wavelength spectral fluorometer.

    Science.gov (United States)

    Goldman, Emily A; Smith, Erik M; Richardson, Tammi L

    2013-03-15

    The utility of a multiple-fixed-wavelength spectral fluorometer, the Algae Online Analyser (AOA), as a means of quantifying chromophoric dissolved organic matter (CDOM) and phytoplankton photosynthetic activity was tested using algal cultures and natural communities from North Inlet estuary, South Carolina. Comparisons of AOA measurements of CDOM to those by spectrophotometry showed a significant linear relationship, but increasing amounts of background CDOM resulted in progressively higher over-estimates of chromophyte contributions to a simulated mixed algal community. Estimates of photosynthetic activity by the AOA at low irradiance (≈ 80 μmol quanta m(-2) s(-1)) agreed well with analogous values from the literature for the chlorophyte, Dunaliella tertiolecta, but were substantially lower than previous measurements of the maximum quantum efficiency of photosystem II (F(v)/F(m)) in Thalassiosira weissflogii (a diatom) and Rhodomonas salina (a cryptophyte). When cells were exposed to high irradiance (1500 μmol quanta m(-2) s(-1)), declines in photosynthetic activity with time measured by the AOA mirrored estimates of cellular fluorescence capacity using the herbicide 3'-(3, 4-dichlorophenyl)-1',1'-dimethyl urea (DCMU). The AOA shows promise as a tool for the continuous monitoring of phytoplankton community composition, CDOM, and the group-specific photosynthetic activity of aquatic ecosystems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Madsen, C.V.; Riisgard, H.U.

    2008-01-01

    Beating cilia are important organelles for swimming in many zooplanktonic aquatic organisms, including many invertebrate larvae, rotifers and ciliates, but other planktonic organisms, such as copepods and brine shrimps, use muscle-powered swimming appendages. In recent studies we found...... of swimming velocity for a 10 degrees C temperature reduction) that is found to be largest for the brine shrimp Artemia salina nauplius (37 %) and the rotifer Brachionus plicatilis (26%), but negligible for the copepod Acartia tonsa (4%). We suggest that experimental data on change in swimming velocity (V......) due to change in kinematic viscosity (v) be correlated in terms of a power law, V proportional to v(-m). The present data on swimming velocity of copepods, brine shrimps and rotifers show values of exponent m approximate to 1.5 to 3, with a trend of decreasing values for increasing size of species...

  10. Effect of the addition of Lactobacillus delbrueckii subsp. delbrueckii on the gut microbiota composition and contribution to the well-being of European sea bass (Dicentrarchus labrax, L.)

    OpenAIRE

    Silvi, Stefania; Nardi, Miria; Sulpizio, Roberto; Orpianesi, Carla; Caggiano, Massimo; Carnevali, Oliana; Cresci, Alberto

    2011-01-01

    The present study aimed to test the effects of probiotic treatment on gut microbiota and the contribution to the well-being of European sea bass (Dicentrarchus labrax, L.). A bacterial strain of Lactobacillus delbrueckii subsp. delbrueckii (AS13B), isolated from adult European sea bass gut, was administered during sea bass development using Brachionus plicatilis and/or Artemia salina as carriers. The effective strain colonization and modulation of the gut microbiota, the mortality and the cor...

  11. EL PAN VS. SALINAS O EL DILEMA DEL PRISIONERO: REFORMA INSTITUCIONAL Y COOPERACIÓN COMO ESTRATEGIA POLÍTICA

    Directory of Open Access Journals (Sweden)

    Alicia Gómez López

    2002-01-01

    Full Text Available Este artículo analiza, desde el punto de vista de la teoría de juegos, la estrategia que el Partido Acción Nacional desarrolló frente al gobierno de Carlos Salinas de Gortari luego de la turbulenta elección presidencial de 1988. El objetivo es demostrar que entre estos adversarios se estableció un tipo de juego cuyo modelo a menudo se utiliza para analizar procesos de transición: el Dilema del prisionero, con un desenlace, al menos en este caso, cooperativo. Como en todo dilema, en este juego la posibilidad de la cooperación implica la existencia de un escenario aceptable para ambos adversarios, pese a que en primer lugar se busquen resultados opuestos. En este caso, dicho escenario se relaciona con el hecho de que el objetivo central en la estrategia panista era lograr reformas institucionales que hicieran avanzar la transición mexicana, de manera que le fuera posible llegar al poder; un objetivo cuya materia —las reformas institucionales— resultaba perfectamente negociable para su adversario presidencial.

  12. Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

    DEFF Research Database (Denmark)

    Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

    Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems (photobio......Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...... was cultivated continuously at temperature of 20ºC and salinity of 30ppt in two tubular PBRs with addition of CO2. The experiment was run two times and each PBR in 18 - 30 days. Periodically, the algae were sampled for analyzing the growth, biochemical composition and production. An exponential light model...

  13. Topography and stoichiometry of acidic proteins in large ribosomal subunits from Artemia salina as determined by crosslinking

    International Nuclear Information System (INIS)

    Uchiumi, T.; Wahba, A.J.; Traut, R.R.

    1987-01-01

    The 60S subunits isolated from Artemia salina ribosomes were treated with the crosslinking reagent 2-iminothiolane under mild conditions. Proteins were extracted and fractions containing crosslinked acidic proteins were obtained by stepwise elution from CM-cellulose. Each fraction was analyzed by diagonal (two-dimensional nonreducing-reducing) NaDodSO 4 /polyacrylamide gel electrophoresis. Crosslinked proteins below the diagonal were radioiodinated and identified by two-dimensional acidic urea-NaDodSO 4 gel electrophoresis. Each of the acidic proteins P1 and P2 was crosslinked individually to the same third protein, PO. The fractions containing acidic proteins were also analyzed by two-dimensional nonequilibrium isoelectric focusing-NaDodSO 4 /polyacrylamide gel electrophoresis. Two crosslinked complexes were observed that coincide in isoelectric positions with monomeric P1 and P2, respectively. Both P1 and P2 appear to form crosslinked homodimers. These results suggest the presence in the 60S subunit of (P1) 2 and (P2) 2 dimers, each of which is anchored to PO. Protein PO appears to play the same role as L10 in Escherichia coli ribosomes and may form a pentameric complex with the two dimers in the 60S subunits

  14. Yaequinolones, new insecticidal antibiotics produced by Penicillium sp. FKI-2140. I. Taxonomy, fermentation, isolation and biological activity.

    Science.gov (United States)

    Uchida, Ryuji; Imasato, Rie; Yamaguchi, Yuichi; Masuma, Rokuro; Shiomi, Kazuro; Tomoda, Hiroshi; Omura, Satoshi

    2006-10-01

    New nine insecticidal antibiotics designated yaequinolones were isolated from the culture broth of the fungal strain Penicillium sp. FKI-2140 by solvent extraction, centrifugal partition chromatography and HPLC. Yaequinolones showed growth inhibitory activity against brine shrimp (Artemia salina). Among them, yaequinolone F has the most potent activity with MIC value of 0.19 microg/ml.

  15. Status and understanding of groundwater quality in the Monterey-Salinas Shallow Aquifer Study Unit, 2012–13: California GAMA Priority Basin Project

    Science.gov (United States)

    Burton, Carmen; Wright, Michael

    2018-05-30

    Groundwater quality in the approximately 7,820-square-kilometer (km2) Monterey-Salinas Shallow Aquifer (MS-SA) study unit was investigated from October 2012 to May 2013 as part of the second phase of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in the central coast region of California in the counties of Santa Cruz, Monterey, and San Luis Obispo. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in cooperation with the U.S. Geological Survey and the Lawrence Livermore National Laboratory.The MS-SA study was designed to provide a statistically robust assessment of untreated-groundwater quality in the shallow aquifer systems. The assessment was based on water-quality samples collected by the U.S. Geological Survey from 100 groundwater sites and 70 household tap sites, along with ancillary data such as land use and well-construction information. The shallow aquifer systems were defined by the depth interval of wells associated with domestic supply. The MS-SA study unit consisted of four study areas—Santa Cruz (210 km2), Pajaro Valley (360 km2), Salinas Valley (2,000 km2), and Highlands (5,250 km2).This study had two primary components: the status assessment and the understanding assessment. The first primary component of this study—the status assessment—assessed the quality of the groundwater resource indicated by data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally present inorganic constituents, such as major ions and trace elements. The status assessment is intended to characterize the quality of groundwater resources in the shallow aquifer system of the MS-SA study unit, not the treated drinking water delivered to consumers by water purveyors. As opposed to the public wells, however, water from private wells, which often tap the shallow aquifer, is usually consumed without any treatment. The second

  16. Arqueología de un espacio habitado, trabajado y defendido. El sistema fortificado de Salinas de Añana (Álava

    Directory of Open Access Journals (Sweden)

    Plata Montero, Alberto

    2009-12-01

    Full Text Available The stratigraphic analysis of the wall of the village of Salinas de Añana (Álava together with the excavations within its fortified area have offered a lot of information about the evolution of its built environment from the Early Medieval period until now. This research paper consists of two parts. Main recorded phases obtained thanks to the archaeological work are firstly described. Comprehension of spatial order resulted after the foundation of a village at the beginnings of the 12th century and the gathering of several hamlets that since the Late Antiquity populated, worked and defended the Valle Salado, is exposed in the second part. In order to understand this process, space syntax analysis, methodology developed within English scientific context, has been applied, showing an special attention to those instruments which enable to determine a global pattern of settlements (Alpha analysis, because this pattern links the social logic of space with the spatial logic of the society that created it.La lectura estratigráfica de la muralla de la villa alavesa de Salinas de Añana, así como la ejecución de excavaciones en su recinto fortificado, nos han proporcionado abundante información sobre la evolución de su paisaje construido desde la Alta Edad Media hasta la actualidad. La investigación que presentamos se divide en dos partes. En la primera, describimos las principales fases documentadas durante la intervención arqueológica. En la segunda, nos hemos centrado en comprender el ordenamiento espacial resultante tras el proceso de fundación de una villa creada a principios del siglo XII en la que, además, se agruparon las distintas comunidades aldeanas que desde la Tardoantigüedad habitaban, trabajaban y defendían el Valle Salado. Para ello, hemos empleado la metodología del «Análisis Sintáctico del Espacio» desarrollada en el mundo anglosajón, prestando una especial atención a las herramientas dirigidas a determinar el patr

  17. Estudo fitoquímico e bioensaio toxicológico frente a larvas de Artemia salina Leach. de três espécies medicinais do gênero Phyllanthus (Phyllanthaceae

    Directory of Open Access Journals (Sweden)

    J. E. Nascimento

    2009-02-01

    Full Text Available

    Avaliou-se o perfil fitoquímico e a toxicidade de três espécies do gênero Phyllanthus (P. niruri, P. amarus e P. tenellus, coletadas em diferentes localidades do estado de Pernambuco, nordeste do Brasil. Os extratos brutos das três espécies foram submetidos a testes convencionais por cromatografia em camada delgada analítica para verificação das classes de metabólitos presentes, e testados frente a larvas de Artemia salina para obtenção das concentrações letais médias (CL50. Os testes fitoquímicos demonstraram a presença de flavonóides, saponinas, terpenos, naftoquinonas, alcalóides, antraquinonas, lignanas e taninos. As três espécies de Phyllanthus apresentaram variações na composição fitoquímica e na toxicidade frente a A. salina. Dependendo do local de coleta, os valores de CL50 variaram de 404,43 ± 49,64 µg/mL a 770,84 ± 51,78 µg/mL para P. niruri, 837,65 ± 61,45 µg/mL a 1075,89 ± 70,72 µg/mL para P. amarus e 534,60 ± 46,83 µg/mL a 1003,62 ± 65,15 µg/mL para P. tenellus. Palavras-chave: Phyllanthus niruri; Phyllanthus amarus,/i>; Phyllanthus tenellus; análise fitoquímica preliminar; bioensaio toxicológico; CL50

  18. Produção e indicadores fisiológicos de alface sob hidroponia com água salina Production and physiologic indicators of lettuce grown in hydroponics with saline water

    Directory of Open Access Journals (Sweden)

    Dalva Paulus

    2010-03-01

    Full Text Available O uso de água salina na produção de hortaliças constitui no momento atividade essencial, tendo em vista o aumento da demanda de água doce, tanto pela atividade agrícola quanto pelo abastecimento urbano e industrial. O objetivo do trabalho foi avaliar a produção e os indicadores fisiológicos de alface cultivada em hidroponia com a utilização de água salina. O experimento foi conduzido em ambiente protegido, em Piracicaba-SP. O delineamento experimental foi de blocos ao acaso, sendo estudados os efeitos de cinco níveis de salinidade da água de irrigação, utilizando-se NaCl [Condutividade elétrica (Cea: 0,42, 1,53, 3,52, 5,55 e 7,43 dS m-1] em duas cultivares de alface (Verônica e Pira Roxa, em esquema fatorial. Foram determinadas massa fresca e seca de folhas, caule, raízes e da parte aérea; teor de nitrato, prolina e clorofila. O aumento da salinidade da água reduziu linearmente as massas fresca e seca das folhas, caule, raízes e da parte aérea. As massas fresca e seca foram 36% e 57% superiores na cultivar Verônica, respectivamente. A cultivar Pira Roxa apresentou maior teor de nitrato 25% (3008 mg L-1, clorofila total 50% (1,46 mg g-1massa fresca e prolina, 71,43% (0,21 µM g-1massa fresca-1 em relação à Verônica, o que pode ser um mecanismo de adaptação daquela cultivar ao estresse salino. Com relação à produtividade comercial, obteve-se uma perda de 69 e 64% para as cultivares Pira Roxa e Verônica, quando se utilizou água mais salina (7,43 dS m-1. Em relação à produção de massa seca, a perda pelo uso dessa água foi de 53% e 44%, respectivamente. Os resultados obtidos em sistema de cultivo hidropônico podem indicar a possibilidade do uso da água salina como alternativa para produção de hortaliças para produtores que têm disponibilidade de água salina e restrita disponibilidade de água doce, embora com redução na produtividade.The use of saline water in the production of vegetables constitutes

  19. Avaliação de extratos de macroalgas bênticas do litoral catarinense utilizando o teste de letalidade para Artemia salina

    Directory of Open Access Journals (Sweden)

    Cintia Lhullier

    Full Text Available Foram coletadas amostras de algas marinhas de 19 espécies (sendo 4 pertencentes ao filo Chlorophyta, 5 ao filo Phaeophyta e 10 ao filo Rhodophyta em dois locais do litoral catarinense. Os extratos etanólicos foram submetidos ao teste de letalidade para larvas de Artemia salina com objetivo de realizar uma triagem das espécies. Dos 26 extratos testados, 25 apresentaram toxicidade significativa em pelo menos uma das 3 concentrações testadas. O grupo de algas vermelhas (Rhodophyta foi o que obteve maior porcentagem de extratos com resultados estatisticamente significativos pelo método do qui-quadrado e também menores valores de CL50, com destaque para Acanthophora spicifera, Hypnea musciformis e Pterocladiella capillacea. Observaram-se diferenças entre as espécies de um mesmo gênero (Codium decorticatum e Codium isthmocladium e também a influência de fatores ambientais (Hypnea musciformis na toxicidade dos extratos.

  20. The Cytotoxicity Study of Carboxymethyl Starch (CMS) of Sago Starch (Metro xylon sago) by Brine Shrimp Lethality Test (Artemia salina nauplii)

    International Nuclear Information System (INIS)

    Ibrahim Ijang; Fazliana Mohd Saaya; Zainon Othman

    2014-01-01

    CMS can be produced by substitution of the hydroxyl groups with sodium monochloroacetate in the presence of strong alkali. Carboxy methylation can be performed in water as a solvent or in a water-miscible organic solvent containing a small amount of water such as ethanol, isopropanol, methanol or toluene. The use of organic solvent will preserve the final product in the granular form and the side product can be washed out easily but some of them may be having potential toxicity and carcinogenic effect. In this study, CMS was investigated the level of toxicity by using brine shrimp lethality (BSLT). Brine shrimp test method was used to screen CMS for their biological activity. The screening results showed that the LC50, of CMS is more than 100 mg/ ml dose concentration. In conclusion, CMS is not cytotoxicity to Artemia salina nauplii and BSLT method is simple, inexpensive and convenient assay for the detection of cytotoxic compound. (author)

  1. Teoría y práctica del personaje histórico: 1968, el personaje histórico y el trabajo de memoria. El caso de Tizoc, emperador de Pablo Salinas (1970)

    OpenAIRE

    Meyrán, Daniel

    2007-01-01

    Tizoc, tlatoani de México-Tenochtitlan (1481-1486) me permite plantear el problema del papel teórico del personaje histórico puesto en escena en el teatro mexicano contemporáneo, como actor metafórico en el deber de memoria sobre 1968 y la masacre de Tlatelolco. Veremos cómo Pablo Salinas se sirve del personaje «antihistórico» para recordar con imaginación en el teatro su propio presente. Tizoc, the tlatoani of México-Tenochtitlan (1481-1486), raises the problem of the theoreti...

  2. Comportamiento geoquímico de las formaciones salinas bajo el efecto de la temperatura y la irradiación

    Directory of Open Access Journals (Sweden)

    Pueyo, J. J.

    1993-08-01

    Full Text Available The production of radiation induced defects, as well as fluid migration (brine and gases, are the most relevant phenomena due to the combined effects of heat and irradiation in repositories emplaced in rock salt. In order to gain knowledge of these phenomena, laboratory experiments on samples coming from the Sallent Mine (Barcelona have been performed. The water content ranges between 0.04 and 1.00 %. Nevertheless, smaller releases of brine are expected, since part of it is present in fluid inclusions of a size below 100 µm. The chemical composition of the brine, which is a key issue in the study of container corrosion, is in the case of the fluid inc1usions enriched in magnesium (1.15 mol/l and potassium (0.31 mol/l. The study of the gas content reveals the absence of toxic gases and the scarcity of hydrogen and methane. Finally, the amount of radiation induced defects, which are controlled by the mineralogical composition of the rock salt, is similar to those obtained with the Jain-Lidiard model.La generación de defectos cristalinos y la migración de las fases fluidas (salmueras y gases, son los efectos más relevantes de la irradiación y la temperatura sobre una formación salina, susceptible de albergar un almacenamiento de residuos radiactivos. Para determinar dichos efectos se ha puesto a punto la metodología necesaria y se ha verificado sobre muestras salinas de la mina de Sallent (Barcelona. El contenido en agua oscila entre 0,04 y 1 %. Sin embargo, la cantidad de salmuera susceptible de migrar será inferior a la total, debido a que parte de esta se encuentra en inclusiones fluidas inferiores a 100 µm. La composición química de la salmuera, factor clave para el estudio de corrosión de contenedores, es de carácter magnésico (1,15 moles/litro y potásico (0,31 moles/litro en el caso de las inclusiones. El análisis de los gases presentes indica la ausencia de gases tóxicos y concentraciones muy bajas de hidrógeno y metano

  3. Groundwater-quality data in the Monterey–Salinas shallow aquifer study unit, 2013: Results from the California GAMA Program

    Science.gov (United States)

    Goldrath, Dara A.; Kulongoski, Justin T.; Davis, Tracy A.

    2016-09-01

    Groundwater quality in the 3,016-square-mile Monterey–Salinas Shallow Aquifer study unit was investigated by the U.S. Geological Survey (USGS) from October 2012 to May 2013 as part of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project. The GAMA Monterey–Salinas Shallow Aquifer study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the shallow-aquifer systems in parts of Monterey and San Luis Obispo Counties and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The shallow-aquifer system in the Monterey–Salinas Shallow Aquifer study unit was defined as those parts of the aquifer system shallower than the perforated depth intervals of public-supply wells, which generally corresponds to the part of the aquifer system used by domestic wells. Groundwater quality in the shallow aquifers can differ from the quality in the deeper water-bearing zones; shallow groundwater can be more vulnerable to surficial contamination.Samples were collected from 170 sites that were selected by using a spatially distributed, randomized grid-based method. The study unit was divided into 4 study areas, each study area was divided into grid cells, and 1 well was sampled in each of the 100 grid cells (grid wells). The grid wells were domestic wells or wells with screen depths similar to those in nearby domestic wells. A greater spatial density of data was achieved in 2 of the study areas by dividing grid cells in those study areas into subcells, and in 70 subcells, samples were collected from exterior faucets at sites where there were domestic wells or wells with screen depths similar to those in nearby domestic wells (shallow-well tap sites).Field water-quality indicators (dissolved oxygen, water temperature, pH, and specific conductance) were measured, and samples for analysis of inorganic

  4. Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts.

    Science.gov (United States)

    Leite, João Jaime Giffoni; Brito, Erika Helena Salles; Cordeiro, Rossana Aguiar; Brilhante, Raimunda Sâmia Nogueira; Sidrim, José Júlio Costa; Bertini, Luciana Medeiros; Morais, Selene Maia de; Rocha, Marcos Fábio Gadelha

    2009-01-01

    The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13 mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7 mg mL-1 for hexane extract and 8.87 mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-(1), from 0.312 to 0.625 mg mL-1 and from 0.031 to 0.625 mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625 mg mL-1, from 0.08 to 0.156 mg mL-1 and from 0.312 to 0.625 mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.

  5. Hydrologic, water-quality, and biological assessment of Laguna de las Salinas, Ponce, Puerto Rico, January 2003-September 2004

    Science.gov (United States)

    Soler-López, Luis R.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús

    2005-01-01

    The Laguna de Las Salinas is a shallow, 35-hectare, hypersaline lagoon (depth less than 1 meter) in the municipio of Ponce, located on the southern coastal plain of Puerto Rico. Hydrologic, water-quality, and biological data in the lagoon were collected between January 2003 and September 2004 to establish baseline conditions. During the study period, rainfall was about 1,130 millimeters, with much of the rain recorded during three distinct intense events. The lagoon is connected to the sea by a shallow, narrow channel. Subtle tidal changes, combined with low rainfall and high evaporation rates, kept the lagoon at salinities above that of the sea throughout most of the study. Water-quality properties measured on-site (temperature, pH, dissolved oxygen, specific conductance, and Secchi disk transparency) exhibited temporal rather than spatial variations and distribution. Although all physical parameters were in compliance with current regulatory standards for Puerto Rico, hyperthermic and hypoxic conditions were recorded during isolated occasions. Nutrient concentrations were relatively low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 1.9 milligrams per liter and the average total phosphorus concentration was 0.4 milligram per liter. Total organic carbon concentrations ranged from 12.0 to 19.0 milligrams per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll a concentration was 13.4 micrograms per liter. Chlorophyll b was detected (detection limits 0.10 microgram per liter) only twice during the study. About 90 percent of the primary productivity in the Laguna de Las Salinas was generated by periphyton such as algal mats and macrophytes such as seagrasses. Of the average net productivity of 13.6 grams of oxygen per cubic meter per day derived from the diel

  6. [Concentrations of alkaloids, cyanogenic glycosides, polyphenols and saponins in selected medicinal plants from Ecuador and their relationship with acute toxicity against Artemia salina].

    Science.gov (United States)

    Jaramillo Jaramillo, Carmita; Jaramillo Espinoza, Anyi; D'Armas, Haydelba; Troccoli, Luis; Rojas de Astudillo, Luisa

    2016-09-01

    Alkaloids, polyphenols, cyanogenic glycosides and saponins are among the main chemical compounds synthesized by plants but not considered essential for their basic metabolism. These compounds have different functions in plants, and have been recognized with medicinal and pharmacological properties. In this research, concentrations of the mentioned secondary metabolites were determined in the medicinal plants Artemisia absinthium, Cnidoscolus aconitifolius, Parthenium hysterophorus, Piper carpunya and Taraxacum officinale, from Ecuador, and related with cytotoxic effects against Artemia salina. Alcoholic and aqueous extracts from leaves of these selected plants were prepared at different concentrations. To assess cytotoxicity of these extracts, different bioassays with A. salina were undertaken, and the mortality rates and LC50 were obtained. Besides, concentrations of alkaloids, cyanogenic glycosides, phenols, tannins and saponins were determined by spectrophotometric methods; this constituted the first report of quantification of secondary metabolites in the selected plants from Ecuador. T. officinale had the highest concentration of total phenols (22.30 ± 0.23 mg/g) and tannins (11.70 ± 0.10 mg/g), C. aconitifolius of cyanogenic glycosides (5.02 ± 0.37 µg/g) and P. hysterophorus of saponins (6.12 ± 0.02 mg/g). Tannins values obtained were not adverse to their consumption. Alcoholic and aqueous extracts of selected plants had hemolytic activity depending on the concentration of saponins. Although the values of cyanogenic glycosides were permissible, it was necessary to monitor the presence of this metabolite in plants to minimize health problems. LC50 values ranged from extremely toxic (3.37 µg/mL) to highly toxic (274.34 μg/mL), in P. carpunya and T. officinale, respectively. From correlation analysis, it was observed that increase values of alkaloids concentrations had highly significant (pplants cytotoxicity decreased significantly (pplant extracts

  7. Ecotoxicology of bromoacetic acid on estuarine phytoplankton

    International Nuclear Information System (INIS)

    Gordon, Ana R.; Richardson, Tammi L.; Pinckney, James L.

    2015-01-01

    Bromoacetic acid is formed when effluent containing chlorine residuals react with humics in natural waters containing bromide. The objective of this research was to quantify the effects of bromoacetic acid on estuarine phytoplankton as a proxy for ecosystem productivity. Bioassays were used to measure the EC 50 for growth in cultured species and natural marine communities. Growth inhibition was estimated by changes in chlorophyll a concentrations measured by fluorometry and HPLC. The EC 50 s for cultured Thalassiosira pseudonana were 194 mg L −1 , 240 mg L −1 for Dunaliella tertiolecta and 209 mg L −1 for Rhodomonas salina. Natural phytoplankton communities were more sensitive to contamination with an EC 50 of 80 mg L −1 . Discriminant analysis suggested that bromoacetic acid additions cause an alteration of phytoplankton community structure with implications for higher trophic levels. A two-fold EC 50 decrease in mixed natural phytoplankton populations affirms the importance of field confirmation for establishing water quality criteria. - Highlights: • Bromoacetic acid exposure resulted in lethal impacts to estuarine phytoplankton. • Cultured phytoplankton were less sensitive to bromoacetic acid than natural communities. • Lab results should be confirmed with field experiments whenever possible. - The toxicology of haloacetic acids has been studied in freshwater ecosystems, and urbanization of the coastal zone is making effects in marine ecosystems equally relevant.

  8. Algal massive growth in relation to water quality and salinity at Damietta, north of Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Ibraheem Deyab

    2015-02-01

    Full Text Available Objective: To relate the proliferation and dominance of certain algal species at the Damietta and its relation to water quality. Methods: Water and algal biomass were bimonthly sampled from five selected sites at Damietta Province, Egypt during 2012. Algae were identified and quantified. Waters, algae and sediment were analyzed. Results: The physicochemical properties of water showed limited seasonal but substantial local variation. The high levels of nitrogen and phosphorus and turbidity of water pointed to marked eutrophication, which could enhance massive algal growth. The temporal fluctuation in temperature, exposure to industrial and domestic sewage and salinity results in succession between blooming algal species. Spirulina platensis and Chlorella vulgaris alternated in a moderately saline water and Oscillatoria agardhii and Mougeotia scalaris in a fresh water body during summer and winter respectively. Likewise, Microcystis aureginosa and Ulva lactuca alternated in a moderately saline site during autumn and summer respectively. Cladophora albida dominated a fish pond of brackish water and Dunaliella salina dominated the most saline water over the whole period of study. Conclusions: Growth of the predominant algal species is correlated to water quality. These species are of considerable nutritive value, with moderate contents of protein, carbohydrate, macronutrients and micronutrients, which evaluates them for usage as food (green and macroalgae, fodder or bio-fertilizer (cyanophytes.

  9. Tolerância ao florescimento precoce e características comerciais de progênies F4 de alface do cruzamento Regina 71 x Salinas 88 = Tolerance to precocious flowering and commerical traits of F4 progenies of hybrid Regina 71 x Salinas 88 lettuce

    Directory of Open Access Journals (Sweden)

    José Luiz Sandes de Carvalho Filho

    2009-01-01

    Full Text Available A alface é uma espécie cujas plantas possuem grande variabilidade no que diz respeito à forma, cor e textura das folhas, caracterizando diferentes tipos comerciais. O grupo folhas lisas ainda se mantém como um dos mais consumidos. A caracterização do tipo de folha é essencial no desenvolvimento de um programa de melhoramento,principalmente, quando a população segregante é oriunda de parentais contrastantes para o caráter. Além disso, a maior parte das cultivares utilizada é sensível ao calor, emitindo a haste floral precocemente. Assim, o objetivo deste trabalho foi avaliar características comercias de progênies F4 de alface e a sua tolerância ao calor, visando obter cultivares com folha lisa tolerantes ao florescimento precoce, resistentes aos nematóides e ao LMV. Avaliaram-se 22 progênies F4 originadas do cruzamento envolvendo as cultivares ‘Regina 71’ e ‘Salinas 88’, previamente selecionadas para tolerância ao calor, resistência aos nematóides das galhas e ao LMV (lettuce mosaic virus. O delineamento foi em blocos casualizados, com quatro repetições. Foram avaliados os tipos de limbo e borda foliares, formação de cabeça e número de dias para a primeira antese. Dentre as 22 progênies avaliadas, três mostraram-semais promissoras à obtenção de linhagens de alface de folhas lisas resistentes ao calor, nematóides das galhas e ao LMV.The lettuce is a plant that features great variability in form, color and texture. The butterleaf variety had remained one of themost consumed lettuce types. The evaluation of leaf type for commercial characters is essential for the development of any improvement program, especially when the parents are divergent types. Furthermore, most cultivars are susceptible to heat. Thus, the objective of the present work was to evaluate F4 progenies of butterleaf lettuce, aiming to select new genotypes for nematode resistance, tolerance to heat and LMV. Twenty-two F3:4 progenieswere

  10. IRRIGAÇÃO COM ÁGUA SALINA NA CULTURA DO AMENDOIM EM SOLO COM BIOFERTILIZANTE BOVINO

    Directory of Open Access Journals (Sweden)

    Geocleber Gomes de Sousa

    2014-06-01

    Full Text Available O experimento foi conduzido na área experimental da Estação Agrometereológica, UFC, em Fortaleza/Ceará, no período de setembro a novembro de 2012, com o objetivo de avaliar o efeito da salinidade da água de irrigação nas características agronômicas do amendoinzeiro, cultivar BRS 1 em solo com e sem biofertilizante bovino. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 5 x 2, com cinco repetições, referente aos valores de condutividade elétrica da água de irrigação:0,8; 1,5; 3,0; 4,5 e 6,0 dS m-1, em solo sem e com biofertilizante bovino, aplicado de uma única vez, ao nível de 10% do volume do substrato, três dias antes da semeadura. As variáveis analisadas foram: número de folhas, altura de plantas, diâmetro do caule, área foliar, comprimento de raiz, matéria seca da parte aérea, da raiz e total. O aumento da concentração salina da água de irrigação reduziu a área foliar, matéria seca da parte aérea, matéria seca total e comprimento da raiz do amendoinzeiro, porém com menor intensidade no solo com o biofertilizante bovino. A elevação da salinidade do solo decorrente da irrigação com água salina provoca redução na altura da planta, diâmetro do caule e matéria seca da raiz. Palavra-chave: estresse salino, índices fisiológicos, insumo orgânico. PEANUT CULTURE IRRIGATED WITH SALINE WATER IN SOIL WITH BOVINE BIOFERTILIZER ABSTRACT This experiment was conducted at the agrometeorological experimental station, at the UFC, Fortaleza-CE (BR, in the period from September 2012 to November 2012, aiming to evaluate the effects of irrigation water salinity on the agronomic characteristics of BRS 1 peanut plant, in bio fertilized and non-bio fertilized soil. Treatments were arranged in a completely randomized design in a 5 x 2 factorial scheme, with five repetitions. Five different saline solutions (or irrigation water, identified by their respective electrical

  11. Isolation and Characterization of Two Lytic Bacteriophages, φSt2 and φGrn1; Phage Therapy Application for Biological Control of Vibrio alginolyticus in Aquaculture Live Feeds.

    Directory of Open Access Journals (Sweden)

    Panos G Kalatzis

    Full Text Available Bacterial infections are a serious problem in aquaculture since they can result in massive mortalities in farmed fish and invertebrates. Vibriosis is one of the most common diseases in marine aquaculture hatcheries and its causative agents are bacteria of the genus Vibrio mostly entering larval rearing water through live feeds, such as Artemia and rotifers. The pathogenic Vibrio alginolyticus strain V1, isolated during a vibriosis outbreak in cultured seabream, Sparus aurata, was used as host to isolate and characterize the two novel bacteriophages φSt2 and φGrn1 for phage therapy application. In vitro cell lysis experiments were performed against the bacterial host V. alginolyticus strain V1 but also against 12 presumptive Vibrio strains originating from live prey Artemia salina cultures indicating the strong lytic efficacy of the 2 phages. In vivo administration of the phage cocktail, φSt2 and φGrn1, at MOI = 100 directly on live prey A. salina cultures, led to a 93% decrease of presumptive Vibrio population after 4 h of treatment. Current study suggests that administration of φSt2 and φGrn1 to live preys could selectively reduce Vibrio load in fish hatcheries. Innovative and environmental friendly solutions against bacterial diseases are more than necessary and phage therapy is one of them.

  12. Effects of selected metal oxide nanoparticles on Artemia salina larvae: evaluation of mortality and behavioural and biochemical responses.

    Science.gov (United States)

    Gambardella, Chiara; Mesarič, Tina; Milivojević, Tamara; Sepčić, Kristina; Gallus, Lorenzo; Carbone, Serena; Ferrando, Sara; Faimali, Marco

    2014-07-01

    The aim was to investigate the toxicity of selected metal oxide nanoparticles (MO-NPs) on the brine shrimp Artemia salina, by evaluating mortality and behavioural and biochemical responses. Larvae were exposed to tin(IV) oxide (stannic oxide (SnO2)), cerium(IV) oxide (CeO2) and iron(II, III) oxide (Fe3O4) NPs for 48 h in seawater, with MO-NP suspensions from 0.01 to 1.0 mg/mL. Mortality and behavioural responses (swimming speed alteration) and enzymatic activities of cholinesterase, glutathione-S-transferase and catalase were evaluated. Although the MO-NPs did not induce any mortality of the larvae, they caused changes in behavioural and biochemical responses. Swimming speed significantly decreased in larvae exposed to CeO2 NPs. Cholinesterase and glutathione-S-transferase activities were significantly inhibited in larvae exposed to SnO2 NPs, whereas cholinesterase activity significantly increased after CeO2 NP and Fe3O4 NP exposure. Catalase activity significantly increased in larvae exposed to Fe3O4 NPs. In conclusion, swimming alteration and cholinesterase activity represent valid endpoints for MO-NP exposure, while glutathione-S-transferase and catalase activities appear to be NP-specific.

  13. Design of an airlift loop bioreactor and pilot scales studies with fluidic oscillator induced microbubbles for growth of a microalgae Dunaliella salina

    Czech Academy of Sciences Publication Activity Database

    Zimmerman, W. B.; Zandi, M.; Bandulasena, H.C.H.; Tesař, Václav; Gilmour, D.J.; Ying, K.

    2011-01-01

    Roč. 88, č. 10 (2011), s. 3357-3369 ISSN 0306-2619 Institutional research plan: CEZ:AV0Z20760514 Keywords : microbbles * microfluidics * algae Subject RIV: BK - Fluid Dynamics Impact factor: 5.106, year: 2011 http://www.sciencedirect.com/science/article/pii/S0306261911001127

  14. Evaluation of Diverse Microalgal Species as Potential Biofuel Feedstocks Grown Using Municipal Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Hiibel, Sage R. [Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV (United States); Department of Civil and Environmental Engineering, University of Nevada Reno, Reno, NV (United States); Lemos, Mark S.; Kelly, Brian P.; Cushman, John C., E-mail: jcushman@unr.edu [Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV (United States)

    2015-05-11

    Microalgae offer great potential as a third-generation biofuel feedstock, especially when grown on wastewater, as they have the dual application for wastewater treatment and as a biomass feedstock for biofuel production. The potential for growth on wastewater centrate was evaluated for forty microalgae strains from fresh (11), brackish (11), or saltwater (18) genera. Generally, freshwater strains were able to grow at high concentrations of centrate, with two strains, Neochloris pseudostigmata and Neochloris conjuncta, demonstrating growth at up to 40% v/v centrate. Fourteen of 18 salt water Dunaliella strains also demonstrated growth in centrate concentrations at or above 40% v/v. Lipid profiles of freshwater strains with high-centrate tolerance were determined using gas chromatography–mass spectrometry and compared against those obtained on cells grown on defined maintenance media. The major lipid compounds were found to be palmitic (16:0), oleic (18:1), and linoleic (18:2) acids for all freshwater strains grown on either centrate or their respective maintenance medium. These results demonstrate the highly concentrated wastewater can be used to grow microalgae, which limits the need to dilute wastewater prior to algal production. In addition, the algae produced generate lipids suitable for biodiesel or green diesel production.

  15. Evaluation of diverse microalgal species as potential biofuel feedstocks grown using municipal wastewater

    Directory of Open Access Journals (Sweden)

    Sage R Hiibel

    2015-05-01

    Full Text Available Microalgae offer great potential as a third-generation biofuel feedstock, especially when grown on wastewater, as they have the dual application for wastewater treatment and as a biomass feedstock for biofuel production. The potential for growth on wastewater centrate was evaluated for forty microalgae strains from fresh (11, brackish (11, or saltwater (18 genera. Generally, freshwater strains were able to grow at high concentrations of centrate, with two strains, Neochloris pseudostigmata and N. conjuncta, demonstrating growth at up to 40% v/v centrate. Fourteen of eighteen salt water Dunaliella strains also demonstrated growth in centrate concentrations at or above 40% v/v. Lipid profiles of freshwater strains with high-centrate tolerance were determined using gas chromatography-mass spectrometry (GC-MS and compared against those obtained on cells grown on defined maintenance media. The major lipid compounds were found to be palmitic (16:0, oleic (18:1, and linoleic (18:2 acids for all freshwater strains grown on either centrate or their respective maintenance medium. These results demonstrate the highly concentrated wastewater can be used to grow microalgae, which limits the need to dilute wastewater prior to algal production. In addition, the algae produced generate lipids suitable for biodiesel or green diesel production.

  16. Estratégias de irrigação com água salina na mamoneira Irrigation strategies with saline water in castor oil plant

    Directory of Open Access Journals (Sweden)

    Maria Eugênia da Costa

    2013-03-01

    Full Text Available Este experimento foi realizado em campo para avaliar estratégias de irrigação com água salina no crescimento e na produção da mamoneira (BRS Energia, além de identificar eventuais estádios de maior tolerância à salinidade e monitorar alguns atributos químicos do solo. Os tratamentos consistiram da irrigação com águas de CE 0,53; 2,09; 3,66 dS m-1 de acordo com a fase de desenvolvimento da cultura, totalizando cinco estratégias de irrigação com água salina e uma testemunha. As avaliações de crescimento foram realizadas aos 20; 40; 60; 80; 100 dias após a semeadura (DAS. As coletas de solo foram realizadas concomitantemente às avaliações de crescimento, nas camadas 0-0,10; 0,10-0,30; 0,30-0,50 m. A irrigação contínua com água de CE 3,66 dS m-1 reduziu a altura de planta, o comprimento de racemo terciário, o número de frutos por área útil e a produtividade de frutos. Essa estratégia aumentou acentuadamente os teores de Na+ e a CE do solo no final do ciclo. Por outro lado, a irrigação com água salina começando aos 45 DAS não prejudicou as variáveis de crescimento e os componentes de produção. Essa estratégia minimizou os impactos negativos sobre a salinidade/sodicidade do solo no final do ciclo. Comportamento similar foi observado para a irrigação contínua com água de CE 2,09 dS m-1 (mistura de águas com CE de 0,53 e 3,66 dS m-1. A mamoneira não apresentou tolerância diferenciada à salinidade em função da fase de desenvolvimento, embora tenha sido prejudicada quando aumentaram a intensidade e a duração do estresse salino.This experiment was conducted under field conditions to evaluate irrigation strategies with saline water on growth and production of castor oil plant (cv. BRS Energia, identify eventual stages with higher tolerance to salinity and monitor some soil chemical attributes. The treatments consisted of irrigations with water of EC 0.53; 2.09; 3.66 dS m-1 according to the development

  17. Changes in growth, carbon and nitrogen enzyme activity and mRNA accumulation in the halophilic microalga Dunaliella viridis in response to NaCl stress

    Science.gov (United States)

    Wang, Dongmei; Wang, Weiwei; Xu, Nianjun; Sun, Xue

    2016-12-01

    Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the most rapid growth was observed at 1.00 mol L-1 NaCl, followed by 2.00 mol L-1 NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L-1 NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L-1 NaCl, respectively. However, the highest extracellular carbonic anhydrase (CA) activity was measured in the presence of 2.00 mol L-1 NaCl, followed by 1.00 mol L-1 NaCl. Different from the two carbon enzymes, nitrate reductase (NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit ( rbcL), and small subunit ( rbcS), attained their highest abundances in the presence of 1.00 and 2.00 mol L-1 NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.

  18. Actividad farmacológica preliminar del fruto de Bromelia pinguin L. (piña de ratón

    Directory of Open Access Journals (Sweden)

    Juan Abreu Payrol

    2001-04-01

    Full Text Available Se presentan los resultados del estudio farmacológico preliminar de un extracto hidroalcohólico concentrado de los frutos de Bromelia pinguin L. (piña de ratón mediante bioensayos sencillos y confiables. Se determinó la toxicidad frente a Artemia salina Leach, que resultó muy baja. Se probó la actividad antihelmíntica contra Lombricus terrestri, con resultados relevantes. El extracto no mostró actividad contra diversas cepas de hongos y bacterias.The results of the preliminary pharmacological study of a concentrated hydroalcoholic extract from the fruits of Bromelia pinguin L. ("piña de ratón" by simple and reliable bioassays are presented. The toxicity against Artemia salina Leach, which was very low, was determined. The anthelmintic activity against Lombricus terrestri was proved with remarkable results. No activity of the extract against the strains of fungi and bacteria was observed.

  19. Degradation models and ecotoxicity in marine waters of two antifouling compounds: sodium hypochlorite and an alkylamine surfactant.

    Science.gov (United States)

    López-Galindo, Cristina; Garrido, M Carmen; Casanueva, José F; Nebot, Enrique

    2010-03-15

    Industrial wastes have a substantial impact on coastal environments. Therefore, to evaluate the impact of cooling water discharges from coastal power plants, we studied the kinetics of the degradative processes and the ecotoxicity of two antifouling products: (1) a classic antifouling product; sodium hypochlorite (NaClO) and (2) an alternative one; aliphatic amines (commercial under the registered trade mark Mexel432). To assess the persistence of both compounds the decay of sodium hypochlorite and the primary biodegradation rate of Mexel432 were determined in natural seawater at 20 degrees C. The results indicated a more rapid decay of NaClO than Mexel432. The degradation behavior of both chemicals was described following a logistic model, which permitted calculating kinetic parameters such as t(50) or t(90). The t(50) was 1h and 2d for NaClO and Mexel432, respectively. To evaluate the potential risks of the aforementioned treatments to marine organisms, the acute toxicity of both antifouling products was studied on the microalgae Isochrysis galbana and Dunaliella salina, and on the invertebrate Brachionus plicatilis, using growth inhibition and death tests as toxic response, respectively. For I. galbana, the 96-h EC(50) values were 2.91+/-0.15mg/L of NaClO and 4.55+/-0.11mg/L of Mexel432. D. salina showed values of 96-h EC(50) of 1.73+/-0.16mg/L of NaClO and 7.21+/-0.1mg/L of Mexel432. Brachionus plicatilis showed a 24-h LC(50) of 1.23+/-0.1mg/L of NaClO and 3.62+/-0.37mg/L of Mexel432. Acute toxicity was highly dependent on the chemical and species tested. NaClO presented more toxic effects than Mexel432, also B. plicatilis was the most sensitive species in both cases. The lowest NOECs obtained, 0.25mg/L for NaClO and 2.12mg/L for Mexel432, were similar to the theoretical residual concentrations of these biocides in cooling water discharges. Therefore, these discharges can cause undesirable negative effects upon the aquatic organisms present.

  20. Role of essential lipids in copepod nutrition: no evidence for trophic upgrading of food quality by a marine ciliate

    DEFF Research Database (Denmark)

    Klein Breteler, W.; Koski, Marja; Rampen, S.

    2004-01-01

    -quality Rhodomonas sp. diet. The specific mass of fatty acids in S. sulcatum was much lower than in the Dunaliella sp. diet, However, the fatty acid composition of the protozoan more or less resembled that of the food, lacking long-chain highly unsaturated fatty acids (HUFAs). Sterols only occurred in Dunaliella sp......The ciliate Strombidium sulcatum was used to feed and grow young stages of the copepods Temora longicornis (Muller) and Pseudocalanus elongatus (Boeck). The ciliate was cultured in the laboratory using either bacteria or the green alga Dunaliella sp. as a food source. Young copepodites of both......., although in low abundance of unuseful Delta7 sterols. Obviously, S. sulcatum did not biochemically enhance bacterial or algal food for subsequent use at higher trophic levels, and only transferred fatty acids without further conversion. The results indicate a deficiency in the ciliate of HUFAs and sterols...

  1. Substituição de alimento vivo por alimento inerte na larvicultura intensiva do tambacu (♀ Colossoma macropomum X ♂ Piaractus mesopotamicus = Replacement of live food for inert food on larviculture of tambacu (♀ Colossoma macropomum X ♂ Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Danieli Cuzini Lombardi

    2008-10-01

    Full Text Available Com este trabalho objetivou-se avaliar a substituição de náuplios de Artemia salina por alimentos inertes durante a larvicultura do tambacu. Na primeira fase, com duração de 12 dias, as larvas foram alimentadas com: náuplio de Artemia salina, cyclop-eeze e ovo de Artemia salina. Na segunda fase, com duração de dez dias, foram utilizadas larvas alimentadas com náuplios de Artemia salina provenientes da primeira fase e testados os mesmos três alimentos. A qualidade da água manteve-se em condições adequadas para alarvicultura nas duas fases. As larvas da primeira fase alimentadas com náuplios de Artemia salina obtiveram os melhores resultados em crescimento, sobrevivência e desempenho produtivo. Na segunda fase, o crescimento, a sobrevivência e o desempenho produtivo das larvas alimentadas com náuplios de Artemia salina e ovo de Artemia salina foram semelhantes. Nas duas fases, o custo com alimento foi mais baixo nas larvas alimentadas com náuplios de Artemia salina. Os resultados obtidos mostram que nas duas fases de larvicultura testadas a oferta de náuplios de Artemia salina é a melhor estratégia alimentar por proporcionar boa sobrevivência, crescimento e bom desempenho produtivo, além de menor custo.The aim of this work was to evaluate the replacement of Artemia salina nauplii by inert food during larviculture of tambacu. On the first phase with duration of 12 days, the larvae were fed with one of the following foods: Artemia salina nauplii, cyclop-eeze or Artemia salina egg. On the second phase, with 10 days of duration, larvae fed with Artemia salina nauplii were utilized in the first experiment and the same food treatments were tested. Water quality was adequate forlarvae rearing in both phases. The larvae from the first phase that fed with Artemia salina nauplii presented better growth, survival rate and yield. On the second phase, the growth, survival and yield of larvae fed with Artemia salina nauplii and eggs were

  2. Substituição de alimento vivo por alimento inerte na larvicultura intensiva do tambacu (♀ Colossoma macropomum X ♂ Piaractus mesopotamicus - DOI: 10.4025/actascianimsci.v30i4.3835 Replacement of live food for inert food on larviculture of tambacu (♀ Colossoma macropomum X ♂ Piaractus mesopotamicus - DOI: 10.4025/actascianimsci.v30i4.3835

    Directory of Open Access Journals (Sweden)

    Levy de Carvalho Gomes

    2009-03-01

    Full Text Available Com este trabalho objetivou-se avaliar a substituição de náuplios de Artemia salina por alimentos inertes durante a larvicultura do tambacu. Na primeira fase, com duração de 12 dias, as larvas foram alimentadas com: náuplio de Artemia salina, cyclop-eeze e ovo de Artemia salina. Na segunda fase, com duração de dez dias, foram utilizadas larvas alimentadas com náuplios de Artemia salina provenientes da primeira fase e testados os mesmos três alimentos. A qualidade da água manteve-se em condições adequadas para a larvicultura nas duas fases. As larvas da primeira fase alimentadas com náuplios de Artemia salina obtiveram os melhores resultados em crescimento, sobrevivência e desempenho produtivo. Na segunda fase, o crescimento, a sobrevivência e o desempenho produtivo das larvas alimentadas com náuplios de Artemia salina e ovo de Artemia salina foram semelhantes. Nas duas fases, o custo com alimento foi mais baixo nas larvas alimentadas com náuplios de Artemia salina. Os resultados obtidos mostram que nas duas fases de larvicultura testadas a oferta de náuplios de Artemia salina é a melhor estratégia alimentar por proporcionar boa sobrevivência, crescimento e bom desempenho produtivo, além de menor custo.The aim of this work was to evaluate the replacement of Artemia salina nauplii by inert food during larviculture of tambacu. On the first phase with duration of 12 days, the larvae were fed with one of the following foods: Artemia salina nauplii, cyclop-eeze or Artemia salina egg. On the second phase, with 10 days of duration, larvae fed with Artemia salina nauplii were utilized in the first experiment and the same food treatments were tested. Water quality was adequate for larvae rearing in both phases. The larvae from the first phase that fed with Artemia salina nauplii presented better growth, survival rate and yield. On the second phase, the growth, survival and yield of larvae fed with Artemia salina nauplii and eggs

  3. Toxicоlogical evaluation of the plant products using Brine Shrimp (Artemia salina L. model

    Directory of Open Access Journals (Sweden)

    Меntor R. Hamidi

    2014-04-01

    Full Text Available Many natural products could serve as the starting point in the development of modern medicines because of their numerous biological and pharmacological activities. However, some of them are known to carry toxicological properties as well. In order to achieve a safe treatment with plant products, numerous research studies have recently been focused on both pharmacology and toxicity of medicinal plants. Moreover, these studies employed efforts for alternative biological assays. Brine Shrimp Lethality Assay is the most convenient system for monitoring biological activities of various plant species. This method is very useful for preliminary assessment of toxicity of the plant extracts. Rapidness, simplicity and low requirements are several advantages of this assay. However, several conditions need to be completed, especially in the means of standardized experimental conditions (temperature, pH of the medium, salinity, aeration and light. The toxicity of herbal extracts using this assay has been determined in a concentration range of 10, 100 and 1000 µg/ml of the examined herbal extract. Most toxicity studies which use the Brine Shrimp Lethality Assay determine the toxicity after 24 hours of exposure to the tested sample. The median lethal concentration (LC50 of the test samples is obtained by a plot of percentage of the dead shrimps against the logarithm of the sample concentration. LC50 values are estimated using a probit regression analysis and compared with either Meyer’s or Clarkson’s toxicity criteria. Furthermore, the positive correlation between Meyer’s toxicity scale for Artemia salina and Gosselin, Smith and Hodge’s toxicity scale for higher animal models confirmed that the Brine Shrimp Lethality Assay is an excellent predictive tool for the toxic potential of plant extracts in humans.

  4. Teores de pigmentos fotossintéticos em caupi inoculado com rizóbio e em condições salinas

    Directory of Open Access Journals (Sweden)

    Jailma Ribeiro de Andrade

    2012-10-01

    Full Text Available RESUMO: A salinidade é um fator estressante que limita a produção das culturas quando encontra-se em quantidades além do limiar tolerável pelas mesmas. Nesse sentido objetivou-se com este trabalho avaliar o teor de clorofila a, b, total e carotenóides em feijoeiro caupi irrigado com diferentes níveis de água salina. O experimento foi conduzido em casa de vegetação na Universidade Federal de Campina Grande (UFCG, a qual, está localizada na zona centro oriental do Estado da Paraíba, no Planalto da Borborema, cujas coordenadas geográficas são latitude sul 7º13’11’’, longitude oeste 35º53’31’’ e altitude de 547,56 m. As variáveis avaliadas foram: clorofilas a, clorofila b, carotenóides, relação clorofila a/clorofila b e relação clorofila total/ carotenóides. A interação de rizóbios e salinidade não teve efeito significativo sobre as variáveis. Já o fator sal isolado foi significativo sobre todas as variáveis avaliadas. Os teores de clorofilas e carotenóides indicam as condições do aparato fotossintético em feijoeiro caupi quando submetido a estresse salino.

  5. Clorofila e carotenoides em maracujazeiro-amarelo irrigado com águas salinas no solo com biofertilizante bovino

    Directory of Open Access Journals (Sweden)

    Lourival Ferreira Cavalcante

    2011-10-01

    Full Text Available Os efeitos deletérios provocados pelo estresse salino resultam em modificações nos mecanismos bioquímicos e fisiológicos das plantas, alterando, dentre outros, os teores foliares de clorofila e carotenoides, comprometendo a atividade fotossintética e, consequentemente, o crescimento, o desenvolvimento, a produção e a adaptabilidade aos ambientes adversos. O objetivo do trabalho foi avaliar os efeitos de diferentes condutividades elétricas da água de irrigação (CEai, associadas às épocas de aplicação de biofertilizante, sobre os teores de pigmentos fotossintéticos para a determinação dos pigmentos cloroplastídicos (clorofila a, b, total e carotenoides do maracujazeiro-amarelo. Os tratamentos foram distribuídos em arranjo fatorial 5 x 4, referentes aos valores de CEai: 0,5; 1,5; 2,5; 3,5 e 4,5 dS m-1, em quatro épocas de aplicação do biofertilizante: sem biofertilizante (SB; aplicação uma semana antes do transplantio (1SAT; a cada 90 dias, a partir do transplantio (90DAT; uma semana antes e a cada 90 dias, após o transplantio (1SAT+90DAT. O aumento da concentração salina da água de irrigação reduziu a eficiência fotossintética nas folhas do maracujazeiro-amarelo, sendo mais drástico na condutividade superior a 2,5 dS m-1. As frequências de aplicação do biofertilizante não influenciaram nas concentrações dos pigmentos fotossintéticos.

  6. Effect of Conway Medium and f/2 Medium on the growth of six genera of South China Sea marine microalgae.

    Science.gov (United States)

    Lananan, Fathurrahman; Jusoh, Ahmad; Ali, Nora'aini; Lam, Su Shiung; Endut, Azizah

    2013-08-01

    A study was performed to determine the effect of Conway and f/2 media on the growth of microalgae genera. Genera of Chlorella sp., Dunaliella sp., Isochrysis sp., Chaetoceros sp., Pavlova sp. and Tetraselmis sp. were isolated from the South China Sea. During the cultivation period, the density of cells were determined using Syringe Liquid Sampler Particle Measuring System (SLS-PMS) that also generated the population distribution curve based on the size of the cells. The population of the microalgae genera is thought to consist of mother and daughter generations since these microalgae genera reproduce by releasing small non-motile reproductive cells (autospores). It was found that the reproduction of Tetraselmis sp., Dunaliella sp. and Pavlova sp. could be sustained longer in f/2 Medium. Higher cell density was achieved by genus Dunaliella, Chlorella and Isochrysis in Conway Medium. Different genera of microalgae had a preference for different types of cultivation media. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Germinação e formação de mudas de coqueiro irrigadas com águas salinas Germination and seedling formation of coconut irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Francisco J. L. Marinho

    2005-09-01

    Full Text Available O cultivo de coqueiro vem crescendo no Nordeste, com aumento de produtividade, quando irrigado. Sendo comuns na região águas salinas e se considerando a carência de dados de pesquisa de salinidade em coqueiro anão-verde (Cocos nucifera L., objetivou-se, através deste trabalho, avaliar os efeitos da irrigação com águas salinas (CEa = 2,2, 5, 10, 15 e 20 dS m-1 sobre a germinação e o crescimento inicial de plântulas, até 120 dias após semeadura (fase I, estendendo-se a avaliação, posteriormente, após repicagem para o viveiro, quando passaram a ser irrigadas com água de CEa = 2,2 dS m-1, durante 120 dias (fase II, estudando-se o efeito residual dos níveis de salinidade aplicados na fase I. Em ambos os experimentos, o delineamento foi inteiramente casualizado, com quatro repetições. As águas salinas foram preparadas com adição de NaCl comercial. Na primeira fase, o incremento da CEa não influenciou significativamente a germinação que variou de 80 a 97,5%, porém afetou a velocidade de germinação e o crescimento das plântulas; na fase de sementeira, a salinidade afetou a fitomassa total a partir de 5,4 dS m-1; o sistema radicular foi a variável mais afetada pela salinidade. Na fase II, as plantas oriundas de germinação sob condições de alta salinidade, após passarem a ser irrigadas com água de 2,2 dS m-1, cresceram no mesmo ritmo daquelas germinadas sem estresse salino.The coconut cultivation is growing in the Northeast Brazil with increase in productivity under irrigated conditions. Saline waters are commonly found in this region and considering the lack of data related to salinity on dwarf-green coconut (Cocos nucifera L., this work had the objective of evaluating the effects of the irrigation with saline waters (ECw = 2.2, 5, 10, 15 and 20 dS m-1 on the germination and the initial growth of seedlings until 120 days after sowing (phase I, extending the evaluation, later, after transplanting in the nursery, when

  8. Analysis of impact of temperature and saltwater on Nannochloropsis salina bio-oil production by ultra high resolution APCI FT-ICR MS

    KAUST Repository

    Sanguineti, Michael Mario

    2015-05-01

    Concentrated Nannochloropsis salina paste was reconstituted in distilled water and synthetic saltwater and processed at 250°C and 300°C via hydrothermal liquefaction. The resulting bio-oils yielded a diverse distribution of product classes, as analyzed by ultra high resolution APCI FT-ICR MS. The organic fractions were analyzed and both higher temperatures and distilled water significantly increase the number of total compounds present and the number of product classes. Major bio-oil products consisted of N1O1, hydrocarbon, and O2 classes, while O1, O4, S1, N1O2, and N2O2 classes represented the more significant minor classes. Both chlorine and sulfur containing compounds were detected in both distilled and saltwater reactions, while fewer numbers of chlorine and sulfur containing products were present in the organic fraction of the saltwater reactions. Further refinement to remove the chlorine and sulfur contents appears necessary with marine microalgal bio-oils produced via hydrothermal liquefaction. The higher heating value (MJ/kg) as calculated by the Boie equation of classes of interest in the bio-oil reveals a significant potential of algal hydrothermal liquefaction products as a sustainable and renewable fuel feedstock. © 2015.

  9. Uso da solução salina para manutenção de acessos venosos em adultos: uma revisão Uso de la solución salina para la manutención de sondas venosas en adultos: una revisión Use of saline solutions for the mantenaince of venous catheters in adults: a review

    Directory of Open Access Journals (Sweden)

    Francimar Tinoco de Oliveira

    2006-12-01

    Full Text Available Trata-se de uma revisão bibliográfica sobre a prática da salinização em cateteres venosos periféricos. O estudo objetivou analisar os artigos científicos sobre o uso de solução salina na manutenção da permeabilidade de cateteres venosos periféricos em adultos, indexados no MedLine e LILACS no período de 1995 a 2005. A amostra consistiu de 5 artigos os quais foram analisados quanto à procedência e periódico de publicação, ao delineamento do estudo, a amostragem, e ao efeito da solução salina. Dois estudos indicam evidências da salinização, outros dois o oposto e um não é conclusivo. Há pequena produção acerca da temática exigindo-se novas pesquisas para validação do método.Es una revisión bibliográfica con el objetivo de analizar los resúmenes de salinización de catéteres venosos en el banco de dados MedLine y LILACS en el período de 1995 a 2005 y la base de datos OVID. La muestra se ha compuesto con cinco artículos que se han analizado a partir de la procedencia y periódico de publicación, el delineamiento del estudio, el tamaño de las muestras y si los resultados son conclusivos o no para evidencias de salinización. Dos estudios indican evidencias del efecto de la salinización en la permeabilidad, otro dos lo contrario y uno no es conclusivo. Se concluye que hay poca producción lo que valida nuevas encuestas.This article is a bibliography review about the use of saline solution in peripheral venous catheters. The study aimed at analyzing scientific articles about the use of saline solution for the maintenance of peripheral venous catheters patency in adults, indexed at the MedLine and LILACS databases in the periods between 1995 and 2005. The sample consisted of 5 articles analyzed in publication frequency, saline solution effects, study delineation, and nursing periodic publications. The review concluded that this thematic has a modest production and not conclusive about the efficacy of the saline

  10. A strain gauge

    DEFF Research Database (Denmark)

    2016-01-01

    The invention relates to a strain gauge of a carrier layer and a meandering measurement grid positioned on the carrier layer, wherein the strain gauge comprises two reinforcement members positioned on the carrier layer at opposite ends of the measurement grid in the axial direction....... The reinforcement members are each placed within a certain axial distance to the measurement grid with the axial distance being equal to or smaller than a factor times the grid spacing. The invention further relates to a multi-axial strain gauge such as a bi-axial strain gauge or a strain gauge rosette where each...... of the strain gauges comprises reinforcement members. The invention further relates to a method for manufacturing a strain gauge as mentioned above....

  11. Development of intra-strain self-cloning procedure for breeding baker's yeast strains.

    Science.gov (United States)

    Nakagawa, Youji; Ogihara, Hiroyuki; Mochizuki, Chisato; Yamamura, Hideki; Iimura, Yuzuru; Hayakawa, Masayuki

    2017-03-01

    Previously reported self-cloning procedures for breeding of industrial yeast strains require DNA from other strains, plasmid DNA, or mutagenesis. Therefore, we aimed to construct a self-cloning baker's yeast strain that exhibits freeze tolerance via an improved self-cloning procedure. We first disrupted the URA3 gene of a prototrophic baker's yeast strain without the use of any marker gene, resulting in a Δura3 homozygous disruptant. Then, the URA3 gene of the parental baker's yeast strain was used as a selection marker to introduce the constitutive TDH3 promoter upstream of the PDE2 gene encoding high-affinity cyclic AMP phosphodiesterase. This self-cloning procedure was performed without using DNA from other Saccharomyces cerevisiae strains, plasmid DNA, or mutagenesis and was therefore designated an intra-strain self-cloning procedure. Using this self-cloning procedure, we succeeded in producing self-cloning baker's yeast strains that harbor the TDH3p-PDE2 gene heterozygously and homozygously, designated TDH3p-PDE2 hetero and TDH3p-PDE2 homo strains, respectively. These self-cloning strains expressed much higher levels of PDE2 mRNA than the parental strain and exhibited higher viability after freeze stress, as well as higher fermentation ability in frozen dough, when compared with the parental strain. The TDH3p-PDE2 homo strain was genetically more stable than the TDH3p-PDE2 hetero strain. These results indicate that both heterozygous and homozygous strains of self-cloning PDE2-overexpressing freeze-tolerant strains of industrial baker's yeast can be prepared using the intra-strain self-cloning procedure, and, from a practical viewpoint, the TDH3p-PDE2 homo strain constructed in this study is preferable to the TDH3p-PDE2 hetero strain for frozen dough baking. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Las expediciones a salinas: caravanas en la pampa colonial. El abastecimiento de sal a Buenos Aires (Siglos XVII y XVIII

    Directory of Open Access Journals (Sweden)

    Gabriel Darío Taruselli

    2005-01-01

    Full Text Available El abastecimiento de sal en cantidades sufi cientes fue una de las principales preocupaciones del Cabildo de Buenos Aires. Fue este un producto de importancia vital no sólo por su aplicación en las comidas cotidianas, sino también por su aplicación en la conservación de las carnes y los cueros. Las características de su uso y su obtención, aumentaron su valor, no sólo comercial sino también estratégico. El hallazgo de yacimientos locales permitió a los habitantes de Buenos Aires abastecerse mediante la práctica de expediciones periódicas que fueron promovidas por las autoridades capitulares, lo que les permitió ejercer un mayor control sobre dicha producción. Como la actividad requería una importante capacidad de transporte y de mano de obra, era una práctica aprovechada por muchos para emplearse en ella y para obtener benefi cios con el comercio que se generaba en la oportunidad. Esto convertía a las expediciones a salinas, organizadas por las autoridades de la ciudad, en grandes caravanas que se internaban en pleno territorio indí-gena, involucrando un amplio conjunto de actores sociales tanto de la ciudad como de la campaña y el mundo indígena

  13. Evaluation of Alpha and Gamma Aluminum Oxide Nanoparticle Accumulation, Toxicity and Depuration in Artemia Salina Larvae

    Science.gov (United States)

    Ates, Mehmet; Demir, Veysel; Arslan, Zikri; Daniels, James; Farah, Ibrahim O.; Bogatu, Corneliu

    2014-01-01

    In this study, Artemia salina (crustacean filter feeders) larvae were used as a test model to investigate the toxicity of aluminum oxide nanoparticles (Al2O3 NPs) on marine microorganisms. The uptake, toxicity and elimination of α-Al2O3 (50 nm and 3.5 μm) and γ-Al2O3 (5 nm and 0.4 μm) NPs were studied. Twenty-four and ninety-six hour exposures of different concentrations of Al2O3 NPs to Artemia larvae were conducted in a seawater medium. When suspended in water, Al2O3 NPs aggregated substantially with the sizes ranging from 6.3 nm to > 0.3 μm for spherical NPs, and from 250 to 756 nm for rod-shaped NPs. The phase contrast microscope images revealed that NPs deposited inside the guts as aggregates. ICP-MS analysis showed that large particles (3.5 μm α-Al2O3) were not taken up by Artemia, while fine NPs (0.4 μm γ-Al2O3) and ultra-fine NPs (5 nm γ-Al2O3 and 50 nm α-Al2O3) accumulated substantially. Differences in toxicity were detected as changing with NP size and morphology. The malondialdehyde (MDA) levels indicated that smaller γ-Al2O3 (5 nm) NPs were more toxic than larger γ-Al2O3 (0.4 μm) particulates in 96 h. The highest mortality was measured as 34% in 96 h for γ-Al2O3 NPs (5 nm) at 100 mg/L (LC50 > 100 mg/L). γ-Al2O3 NPs were more toxic than α-Al2O3 NPs at in all conditions. PMID:24753078

  14. Evaluación de la gestión en el Parque Regional de las Salinas y Arenales de San Pedro del Pinatar (Murcia

    Directory of Open Access Journals (Sweden)

    Gustavo A. Ballesteros Pelegrín

    2014-01-01

    Full Text Available El Parque Regional de las Salinas y Arenales de San Pedro del Pinatar es un territorio multifuncional desde el punto de vista social, económico y ambiental, donde es imposible separar y, por tanto gestionar de forma independiente, las tramas paisajísticas y ecológicas de las tramas socioeconómicas. Para su gestión, la Administración se apoya en el Plan de Ordenación de los Recursos Naturales aprobado en 1995, que sin embargo ha sido ejecutado en el 50 % de su articulado. Se desarrollan diversas iniciativas de conservación de fauna y flora silvestre, recogida de residuos sólidos, una adecuada información al visitante y mejora del conocimiento de los diferentes elementos de los espacios protegido. Sin embargo la participación social es escasa, la Junta Rectora se ha reunido en solo cuatro ocasiones, la última en 2001, se han producido desarrollos urbanísticos en la periferia del Parque que producen deterioro paisajístico y se han desarrollado una serie de infraestructuras que han reducido en unas 7 hectáreas la superficie protegida.

  15. Strain hardening rate sensitivity and strain rate sensitivity in TWIP steels

    Energy Technology Data Exchange (ETDEWEB)

    Bintu, Alexandra [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Vincze, Gabriela, E-mail: gvincze@ua.pt [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Picu, Catalin R. [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Lopes, Augusto B. [CICECO, Department of Materials and Ceramic Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Grácio, Jose J. [TEMA, Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 (Portugal); Barlat, Frederic [Materials Mechanics Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2015-04-01

    TWIP steels are materials with very high strength and exceptional strain hardening capability, parameters leading to large energy absorption before failure. However, TWIP steels also exhibit reduced (often negative) strain rate sensitivity (SRS) which limits the post-necking deformation. In this study we demonstrate for an austenitic TWIP steel with 18% Mn a strong dependence of the twinning rate on the strain rate, which results in negative strain hardening rate sensitivity (SHRS). The instantaneous component of SHRS is large and negative, while its transient is close to zero. The SRS is observed to decrease with strain, becoming negative for larger strains. Direct observations of the strain rate dependence of the twinning rate are made using electron microscopy and electron backscatter diffraction, which substantiate the proposed mechanism for the observed negative SHRS.

  16. Strain hardening rate sensitivity and strain rate sensitivity in TWIP steels

    International Nuclear Information System (INIS)

    Bintu, Alexandra; Vincze, Gabriela; Picu, Catalin R.; Lopes, Augusto B.; Grácio, Jose J.; Barlat, Frederic

    2015-01-01

    TWIP steels are materials with very high strength and exceptional strain hardening capability, parameters leading to large energy absorption before failure. However, TWIP steels also exhibit reduced (often negative) strain rate sensitivity (SRS) which limits the post-necking deformation. In this study we demonstrate for an austenitic TWIP steel with 18% Mn a strong dependence of the twinning rate on the strain rate, which results in negative strain hardening rate sensitivity (SHRS). The instantaneous component of SHRS is large and negative, while its transient is close to zero. The SRS is observed to decrease with strain, becoming negative for larger strains. Direct observations of the strain rate dependence of the twinning rate are made using electron microscopy and electron backscatter diffraction, which substantiate the proposed mechanism for the observed negative SHRS

  17. Variation in the strain anisotropy of Zircaloy with temperature and strain

    International Nuclear Information System (INIS)

    Hindle, E.D.; Worswick, D.

    1984-04-01

    Strain anisotropy was investigated at temperatures in the range 293 to 1117K in circular tensile specimens prepared from rolled Zircaloy-2 plate so that their tensile axes were parallel to and transverse to the rolling direction. The strain anisotropy factor for both types of specimen increased markedly in the high alpha phase region above 923K reaching a maximum at circa 1070K. Above this temperature in the alpha-plus-beta phase region the strain anisotropy decreased rapidly as the proportion of beta phase increased and was almost non-existent at 1173K. The strain anisotropy was markedly strain dependent, particularly in the high alpha phase region. The study was extended to Zircaloy-4 pressurized water reactor (PWR) 17 x 17 type fuel rod tubing specimens which were strained under biaxial conditions using cooling conditions which promoted uniform diametral strain over most of their lengths (circa 250 mm). In these circumstances the strain anisotropy is manifest by a reduction in length. Measurement of this change along with that in diameter and wall thickness produced data from which the strain anisotropy factor was calculated. The results, although influenced by additional factors discussed in the paper, were similar to those observed in the uniaxial Zircaloy-2 tensile tests. (author)

  18. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available Although cutaneous ulcers (CU in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions.

  19. Factors affecting finite strain estimation in low-grade, low-strain clastic rocks

    Science.gov (United States)

    Pastor-Galán, Daniel; Gutiérrez-Alonso, Gabriel; Meere, Patrick A.; Mulchrone, Kieran F.

    2009-12-01

    The computer strain analysis methods SAPE, MRL and DTNNM have permitted the characterization of finite strain in two different regions with contrasting geodynamic scenarios; (1) the Talas Ala Tau (Tien Shan, Kyrgyzs Republic) and (2) the Somiedo Nappe and Narcea Antiform (Cantabrian to West Asturian-Leonese Zone boundary, Variscan Belt, NW of Iberia). The performed analyses have revealed low-strain values and the regional strain trend in both studied areas. This study also investigates the relationship between lithology (grain size and percentage of matrix) and strain estimates the two methodologies used. The results show that these methods are comparable and the absence of significant finite strain lithological control in rocks deformed under low metamorphic and low-strain conditions.

  20. Phylogenetic distribution of roseobacticides in the Roseobacter group and their effect on microalgae

    DEFF Research Database (Denmark)

    Sonnenschein, Eva C.; Phippen, Christopher Broughton William; Bentzon-Tilia, Mikkel

    2018-01-01

    not produce roseobacticides, possibly due to a transposable element. TDA-producing Ruegeria and Pseudovibrio did not produce roseobacticides. Addition of roseobacticide-containing bacterial extracts affected the growth of the microalgae Rhodomonas salina, Thalassiosira pseudonana and Emiliania huxleyi, while...... growth of Tetraselmis suecica was unaffected. During co-cultivation, growth of E. huxleyi was initially stimulated by the roseobacticide producer DSM 17395, while the subsequent decline in algal cell numbers during senescence was enhanced. Strain 27-4 that does not produce roseobacticides had no effect...

  1. Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado seed extracts Composição química, toxicidade, atividade larvicida e antifúngica de extratos de semente de Persea americana (abacate

    Directory of Open Access Journals (Sweden)

    João Jaime Giffoni Leite

    2009-04-01

    Full Text Available The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7mg mL-1 for hexane extract and 8.87mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-¹, from 0.312 to 0.625mg mL-1 and from 0.031 to 0.625mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625mg mL-1, from 0.08 to 0.156mg mL-1 and from 0.312 to 0.625mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.O presente estudo teve como objetivo testar os extratos hexânico e metanólico das sementes do abacate, a fim de determinar sua toxicidade em Artemia salina, avaliar a atividade larvicida frente ao Aedes aegypti, bem como verificar o potencial antifúngico in vitro contra cepas de Candida spp, Cryptococcus neoformans e Malassezia pachydermatis, através da técnica de microdiluição. Os extratos hexânico e metanólico das sementes de abacate apresentaram no teste de toxicidade frente à Artemia salina, valores de LC50 2,37 e 24,13mg L-1, respectivamente; contra as larvas do Aedes aegypti os resultados obtidos foram LC50 16,7mg L-1 para o extrato hexânico e 8,87mg

  2. Efeito da carga de frutos e concentrações salinas no crescimento do meloeiro Cultivado em substrato Effect of fruit load and saline concentrations on the growth of melon cultivated under protected environment

    Directory of Open Access Journals (Sweden)

    Tatiana da S Duarte

    2008-09-01

    Full Text Available O objetivo foi avaliar o efeito do número de frutos por planta e de concentrações salinas em solução nutritiva recirculante, no crescimento do meloeiro cultivado em ambiente protegido e em substrato de casca de arroz crua, durante os meses de fevereiro a maio de 2003. Três números de frutos por planta (2, 3 e 4 e três concentrações salinas da solução nutritiva (1,9; 2,3 e 2,9 dS m-1 foram estudados. A partir dos dados da matéria seca (MS e fresca (MF e da área foliar, acumuladas aos 62 dias após o transplante, foi determinada a produção e a distribuição de biomassa entre as diferentes partes da planta. Os frutos compreenderam de 49 a 55% da MS aérea total produzida pela planta, demonstrando que estes são os órgãos drenos de assimilados mais potentes. O aumento do número de frutos reduziu o peso médio dos frutos, sem afetar a produção e a distribuição de MS total, vegetativa e generativa. Entretanto, aumentou levemente a produção de MF dos frutos e da parte aérea como um todo, favorecendo a distribuição de MF para os frutos. Portanto, o acúmulo de água nos frutos ocorreu em uma proporção diferente do acúmulo da MS. A menor concentração salina da solução nutritiva testada pode ser indicada para o cultivo do meloeiro em substrato de casca de arroz crua durante o outono, pois promove um crescimento da planta similar ao observado nas concentrações mais altas.The effect of fruit load and of saline concentrations in nutrient solution recirculating, was evaluated on the growth of melon plants cultivated under protected cultivation and in raw rice husk, during the months February to May of 2003. Three numbers of fruits/plant (2, 3 and 4 and three saline concentrations of the nutrient solution (1,9; 2,3 and 2,9 dS m-1 were studied. From the data of dry and fresh matter (DM and FM, and of the leaf area accumulated at 62 days after setting, the biomass production and distribution among the different plant parts

  3. Stress-strain properties of railway steel at strain rates of upto 105 per second

    International Nuclear Information System (INIS)

    Hashmi, M.S.J.; Islam, M.N.

    1985-01-01

    This paper presents the stress-strain characteristics of railway steel at strain rates of up to 10 5 /s at room temperature determined by a new technique. In determining the results, account has been taken of the strain-rate variation, the total strain and the strain rate history. The effect of friction, material inertia and temperature rise is also assessed and an empirical constitutive equation describing the strain-rate and strain sensitive flow stress for this type of steel is proposed. (orig.)

  4. Comparison of Thermal Creep Strain Calculation Results Using Time Hardening and Strain Hardening Rules

    International Nuclear Information System (INIS)

    Kim, Junehyung; Cheon, Jinsik; Lee, Byoungoon; Lee, Chanbock

    2014-01-01

    One of the design criteria for the fuel rod in PGSFR is the thermal creep strain of the cladding, because the cladding is exposed to a high temperature for a long time during reactor operation period. In general, there are two kind of calculation scheme for thermal creep strain: time hardening and strain hardening rules. In this work, thermal creep strain calculation results for HT9 cladding by using time hardening and strain hardening rules are compared by employing KAERI's current metallic fuel performance analysis code, MACSIS. Also, thermal creep strain calculation results by using ANL's metallic fuel performance analysis code, LIFE-METAL which adopts strain hardening rule are compared with those by using MACSIS. Thermal creep strain calculation results for HT9 cladding by using time hardening and strain hardening rules were compared by employing KAERI's current metallic fuel performance analysis code, MACSIS. Also, thermal creep strain calculation results by using ANL's metallic fuel performance analysis code, LIFE-METAL which adopts strain hardening rule were compared with those by using MACSIS. Tertiary creep started earlier in time hardening rule than in strain hardening rule. Also, calculation results by MACSIS with strain hardening and those obtained by using LIFE-METAL were almost identical to each other

  5. Artisanal salt production in Aveiro/Portugal - an ecofriendly process.

    Science.gov (United States)

    Rodrigues, Carolina M; Bio, Ana; Amat, Francisco; Vieira, Natividade

    2011-11-04

    Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend.It is, however, possible to generate revenue from salinas at several levels, not merely in terms of good quality salt production, but also by obtaining other products that can be commercialized, or by exploring their potential for tourism, and as research facilities, among others. Furthermore, with an adequate management, biodiversity can be restored to abandoned salinas, which constitute important feeding and breeding grounds for resident and migratory aquatic birds, many of which are protected by European Community Directives.The aims of this manuscript are to present a brief overview on the current state of sea salt exploitation in Portugal and to stress the importance of recovering these salinas for the conservation of this particular environment, for the regional economy, the scientific community and the general public. The Aveiro salina complex is presented in detail, to exemplify salina structure and functioning, as well as current problems and potential solutions for artisanal salinas.

  6. Limitations of Hollomon and Ludwigson stress-strain relations in assessing the strain hardening parameters

    International Nuclear Information System (INIS)

    Samuel, K G

    2006-01-01

    It is shown that the deviation from the ideal Hollomon relation in describing the stress-strain behaviour is characteristic of all materials at low strains. The Ludwigson relation describing the deviation from the Hollomon relation at low strains is critically analysed and it is shown that the deviation at low strains is a consequence of some unknown 'plastic strain equivalent' present in the material. Stress strain curves obeying an ideal Hollomon relation as well as that of a structurally modified (prior cold worked) material were simulated and compared. The results show that the yield strength and the flow strength of a material at constant strain rate and temperature are dictated by the magnitude of the 'plastic strain equivalent' term. It is shown that this component need not necessarily mean a prior plastic strain present in the material due to prior cold work alone and that prior cold work strain will add to this. If this component is identified, the stress-strain behaviour can be adequately described by the Swift relation. It is shown that in both formalisms, the strain hardening index is a function of the yield strength of the material

  7. Strained Silicon Photonics

    Directory of Open Access Journals (Sweden)

    Ralf B. Wehrspohn

    2012-05-01

    Full Text Available A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is investigated, which may enable the construction of optically active photonic devices made of silicon.

  8. Modelization of tritium transfer into the organic compartments of algae

    International Nuclear Information System (INIS)

    Bonotto, S.; Gerber, G.B.; Arapis, G.; Kirchmann, R.

    1982-01-01

    Uptake of tritium oxide and its conversion into organic tritium was studied in four different types of algae with widely varying size and growth characteristics (Acetabularia acetabulum, Boergesenia forbesii, two strains of Chlamydomonas and Dunaliella bioculata). Water in the cell and the vacuales equilibrates rapidly with external tritium water. Tritium is actively incorporated into organically bound form as the organisms grow. During the stationary phase, incorporation of tritium is slow. There exists a discrimination against the incorporation of tritium into organically bound form. A model has been elaborated taking in account these different factors. It appears that transfer of organic tritium by algae growing near the sites of release would be significant only for actively growing algae. Algae growing slowly may, however, be useful as cumulative indicators of discontinuous tritium release. (author)

  9. Ground-Water Quality Data in the Monterey Bay and Salinas Valley Basins, California, 2005 - Results from the California GAMA Program

    Science.gov (United States)

    Kulongoski, Justin T.; Belitz, Kenneth

    2007-01-01

    Ground-water quality in the approximately 1,000-square-mile Monterey Bay and Salinas Valley study unit was investigated from July through October 2005 as part of the California Ground-Water Ambient Monitoring and Assessment (GAMA) program. The study was designed to provide a spatially unbiased assessment of raw ground-water quality, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 94 public-supply wells and 3 monitoring wells in Monterey, Santa Cruz, and San Luis Obispo Counties. Ninety-one of the public-supply wells sampled were selected to provide a spatially distributed, randomized monitoring network for statistical representation of the study area. Six wells were sampled to evaluate changes in water chemistry: three wells along a ground-water flow path were sampled to evaluate lateral changes, and three wells at discrete depths from land surface were sampled to evaluate changes in water chemistry with depth from land surface. The ground-water samples were analyzed for volatile organic compounds (VOCs), pesticides, pesticide degradates, nutrients, major and minor ions, trace elements, radioactivity, microbial indicators, and dissolved noble gases (the last in collaboration with Lawrence Livermore National Laboratory). Naturally occurring isotopes (tritium, carbon-14, helium-4, and the isotopic composition of oxygen and hydrogen) also were measured to help identify the source and age of the sampled ground water. In total, 270 constituents and water-quality indicators were investigated for this study. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain water quality. In addition, regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. In this study, only six constituents, alpha radioactivity, N

  10. Amerindian Helicobacter pylori strains go extinct, as european strains expand their host range.

    Directory of Open Access Journals (Sweden)

    Maria G Domínguez-Bello

    Full Text Available We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori strains would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes of 131 strains: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all strains that had been cultured from Africans were African strains (hpAfrica1, all from Spanish were European (hpEurope and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori strains were hspAmerind. Strains hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination. The lower genetic structure in hpEurope strains is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear. This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.

  11. Avaliação da hiperresponsividade brônquica à solução salina hipertônica em crianças e adolescentes Bronchial hyperresponsiveness to hypertonic saline challenge in children and adolescents

    Directory of Open Access Journals (Sweden)

    Paulo Kussek

    2006-06-01

    Full Text Available OBJETIVO: Avaliar a hiperresponsividade brônquica à solução salina hipertônica a 4,5% como método alternativo a outros agentes broncoconstritores e sua relação com a sensibilização alérgica do paciente. MÉTODOS: Estudo transversal, experimental, com 85 indivíduos assim distribuídos: 45 no grupo de asmáticos e 17 no grupo controle não asmáticos e não alérgicos, que completaram o teste. Para nebulizar a solução salina hipertônica foi utilizado um nebulizador ultra-sônico de grande volume, sucessivamente durante 0,5, 1, 2, 4 e 8 minutos até haver queda > 15% em relação ao volume expiratório forçado no primeiro segundo basal. A dosagem de imunoglobulina E específica ao Dermatophagoides pteronyssinus por ImmunoCap foi considerada positiva quando > 0,35 kU/L. RESULTADOS: No grupo de asmáticos, 36 apresentaram queda média do volume expiratório forçado no primeiro segundo de 27,4% após nebulização de solução salina hipertônica. Nenhum do grupo controle (imunoglobulina E OBJECTIVE: To assess airway hyperresponsiveness to 4.5% hypertonic saline solution in comparison to that obtained through challenge with other bronchoconstriction agents and in relation to patient allergic sensitization. METHODS: A cross-sectional, experimental study was conducted, initially involving 85 subjects. After exclusions, the final sample consisted of 62 patients, divided into two groups: a study group of those with asthma (n = 45 and a control group of those with no asthma or allergies (n = 17. Hypertonic saline was nebulized using an ultrasonic nebulizer and administered successively for 0.5, 1, 2, 4 and 8 minutes until a drop in forced expiratory volume in one second of = 15% was achieved in relation to the baseline value. The level of specific immunoglobulin E to Dermatophagoides pteronyssinus level was determined by ImmunoCAP assay and was considered positive when > 0.35 kU/L. RESULTS: In the 36 asthma group subjects presenting a

  12. Retraction: Hazani A, Ibrahim M, Shehata A, El-Gaaly G, Daoud M, Fouad D, Rizwana H, Moubayed N. Ecotoxicity of Ag-nanoparticles on two microalgae, Chlorella vulgaris and Dunaliella tertiolecta. Arch Biol Sci. 2013;65(4:1447-1457. DOI: 10.2298/ABS1304447H

    Directory of Open Access Journals (Sweden)

    Editorial

    2016-01-01

    Full Text Available This is a notice of retraction of the article: Ecotoxicity of Ag-nanoparticles on two microalgae, Chlorella vulgaris and Dunaliella tertiolecta, published in the Archives of Biological Sciences in 2013, Vol. 65, Issue 4. The Editor-in-Chief has been informed that this paper is a duplicate of an earlier paper: Hazani A, Ibrahim M, Arif I, Shehata A, EL-Gaaly G, Daoud M, Fouad D, Rizwana H, Moubayed N. Ecotoxicity of Ag-Nanoparticles to Microalgae. J Pure Appl Microbiol. 2013;7(Spl. Ed.: 233-241. This claim is correct and the entire paper is a verbatim copy of the earlier one. After confirmation of this fact, the Editor-in-Chief of the Archives of Biological Sciences has decided to retract the paper immediately. We apologize to the readers of the journal that it took so many years to notice this error and to retract the paper. We request readers of the journal to directly get in touch with the editorial office and the editors of the journal for similar cases in the future, so that they can be handled promptly. Link to the retracted article 10.2298/ABS1304447H

  13. Measurement of Strain and Strain Rate during the Impact of Tennis Ball Cores

    Directory of Open Access Journals (Sweden)

    Ben Lane

    2018-03-01

    Full Text Available The aim of this investigation was to establish the strains and strain rates experienced by tennis ball cores during impact to inform material characterisation testing and finite element modelling. Three-dimensional surface strains and strain rates were measured using two high-speed video cameras and corresponding digital image correlation software (GOM Correlate Professional. The results suggest that material characterisation testing to a maximum strain of 0.4 and a maximum rate of 500 s−1 in tension and to a maximum strain of −0.4 and a maximum rate of −800 s−1 in compression would encapsulate the demands placed on the material during impact and, in turn, define the range of properties required to encapsulate the behavior of the material during impact, enabling testing to be application-specific and strain-rate-dependent properties to be established and incorporated in finite element models.

  14. Strain measurement based battery testing

    Science.gov (United States)

    Xu, Jeff Qiang; Steiber, Joe; Wall, Craig M.; Smith, Robert; Ng, Cheuk

    2017-05-23

    A method and system for strain-based estimation of the state of health of a battery, from an initial state to an aged state, is provided. A strain gauge is applied to the battery. A first strain measurement is performed on the battery, using the strain gauge, at a selected charge capacity of the battery and at the initial state of the battery. A second strain measurement is performed on the battery, using the strain gauge, at the selected charge capacity of the battery and at the aged state of the battery. The capacity degradation of the battery is estimated as the difference between the first and second strain measurements divided by the first strain measurement.

  15. Strain measurement technique

    International Nuclear Information System (INIS)

    1987-01-01

    The 10 contributions are concerned with selected areas of application, such as strain measurements in wood, rubber/metal compounds, sets of strain measurements on buildings, reinforced concrete structures without gaps, pipes buried in the ground and measurements of pressure fluctuations. To increase the availability and safety of plant, stress analyses were made on gas turbine rotors with HT-DMS or capacitive HT-DMS (high temperature strain measurements). (DG) [de

  16. Strain expansion-reduction approach

    Science.gov (United States)

    Baqersad, Javad; Bharadwaj, Kedar

    2018-02-01

    Validating numerical models are one of the main aspects of engineering design. However, correlating million degrees of freedom of numerical models to the few degrees of freedom of test models is challenging. Reduction/expansion approaches have been traditionally used to match these degrees of freedom. However, the conventional reduction/expansion approaches are only limited to displacement, velocity or acceleration data. While in many cases only strain data are accessible (e.g. when a structure is monitored using strain-gages), the conventional approaches are not capable of expanding strain data. To bridge this gap, the current paper outlines a reduction/expansion technique to reduce/expand strain data. In the proposed approach, strain mode shapes of a structure are extracted using the finite element method or the digital image correlation technique. The strain mode shapes are used to generate a transformation matrix that can expand the limited set of measurement data. The proposed approach can be used to correlate experimental and analytical strain data. Furthermore, the proposed technique can be used to expand real-time operating data for structural health monitoring (SHM). In order to verify the accuracy of the approach, the proposed technique was used to expand the limited set of real-time operating data in a numerical model of a cantilever beam subjected to various types of excitations. The proposed technique was also applied to expand real-time operating data measured using a few strain gages mounted to an aluminum beam. It was shown that the proposed approach can effectively expand the strain data at limited locations to accurately predict the strain at locations where no sensors were placed.

  17. Unlocking nature’s treasure-chest: screening for oleaginous algae

    Science.gov (United States)

    Slocombe, Stephen P.; Zhang, QianYi; Ross, Michael; Anderson, Avril; Thomas, Naomi J.; Lapresa, Ángela; Rad-Menéndez, Cecilia; Campbell, Christine N.; Black, Kenneth D.; Stanley, Michele S.; Day, John G.

    2015-01-01

    Micro-algae synthesize high levels of lipids, carbohydrates and proteins photoautotrophically, thus attracting considerable interest for the biotechnological production of fuels, environmental remediation, functional foods and nutraceuticals. Currently, only a few micro-algae species are grown commercially at large-scale, primarily for “health-foods” and pigments. For a range of potential products (fuel to pharma), high lipid productivity strains are required to mitigate the economic costs of mass culture. Here we present a screen concentrating on marine micro-algal strains, which if suitable for scale-up would minimise competition with agriculture for water. Mass-Spectrophotometric analysis (MS) of nitrogen (N) and carbon (C) was subsequently validated by measurement of total fatty acids (TFA) by Gas-Chromatography (GC). This identified a rapid and accurate screening strategy based on elemental analysis. The screen identified Nannochloropsis oceanica CCAP 849/10 and a marine isolate of Chlorella vulgaris CCAP 211/21A as the best lipid producers. Analysis of C, N, protein, carbohydrate and Fatty Acid (FA) composition identified a suite of strains for further biotechnological applications e.g. Dunaliella polymorpha CCAP 19/14, significantly the most productive for carbohydrates, and Cyclotella cryptica CCAP 1070/2, with utility for EPA production and N-assimilation. PMID:26202369

  18. Rat Strain Ontology: structured controlled vocabulary designed to facilitate access to strain data at RGD.

    Science.gov (United States)

    Nigam, Rajni; Munzenmaier, Diane H; Worthey, Elizabeth A; Dwinell, Melinda R; Shimoyama, Mary; Jacob, Howard J

    2013-11-22

    The Rat Genome Database (RGD) ( http://rgd.mcw.edu/) is the premier site for comprehensive data on the different strains of the laboratory rat (Rattus norvegicus). The strain data are collected from various publications, direct submissions from individual researchers, and rat providers worldwide. Rat strain, substrain designation and nomenclature follow the Guidelines for Nomenclature of Mouse and Rat Strains, instituted by the International Committee on Standardized Genetic Nomenclature for Mice. While symbols and names aid in identifying strains correctly, the flat nature of this information prohibits easy search and retrieval, as well as other data mining functions. In order to improve these functionalities, particularly in ontology-based tools, the Rat Strain Ontology (RS) was developed. The Rat Strain Ontology (RS) reflects the breeding history, parental background, and genetic manipulation of rat strains. This controlled vocabulary organizes strains by type: inbred, outbred, chromosome altered, congenic, mutant and so on. In addition, under the chromosome altered category, strains are organized by chromosome, and further by type of manipulations, such as mutant or congenic. This allows users to easily retrieve strains of interest with modifications in specific genomic regions. The ontology was developed using the Open Biological and Biomedical Ontology (OBO) file format, and is organized on the Directed Acyclic Graph (DAG) structure. Rat Strain Ontology IDs are included as part of the strain report (RS: ######). As rat researchers are often unaware of the number of substrains or altered strains within a breeding line, this vocabulary now provides an easy way to retrieve all substrains and accompanying information. Its usefulness is particularly evident in tools such as the PhenoMiner at RGD, where users can now easily retrieve phenotype measurement data for related strains, strains with similar backgrounds or those with similar introgressed regions. This

  19. Variation in the strain anisotropy of Zircaloy with temperature and strain

    International Nuclear Information System (INIS)

    Hindle, E.D.; Worswick, D.

    1984-01-01

    The strong crystallographic texture which is developed during the fabrication of zirconium-based alloys causes pronounced anisotropy in their mechanical properties, particularly deformation. The tendency for circular-section tension specimens with a high concentration of basal poles in one direction to become elliptical when deformed in tension has been used in this study to provide quantitative data on the effects of both strain and temperature on strain anisotropy. Tension tests were carried out over a temperature range of 293 to 1193 K on specimens machined from Zircaloy-2 plate. The strain anisotropy was found to increase markedly at temperatures over 923 K, reaching a maximum in the region of 1070 K. The strain anisotropy increased with increasing strain in this temperature region. The study was extended to Zircaloy-4 pressurized-water reactor fuel cladding by carrying out tube swelling tests and evaluating the axial deformation produced. Although scatter in the test results was higher than that exhibited in the tension tests, the general trend in the data was similar. The effects of the strain anisotropy observed are discussed in relation to the effects of temperature on the ductility of Zircaloy fuel cladding tubes during postulated largebreak loss-of-coolant accidents

  20. Fungal population in soils producing quinoa (Chenopodium quinoa Willd, under different management systems in the community Kerecaya Municipality of Salinas de Garci Mendoza

    Directory of Open Access Journals (Sweden)

    Paco-Pérez Victor

    2017-08-01

    Full Text Available The Kerecaya community (3700-4000 msnm of the municipality of Salinas of Garci Mendoza of the south altiplano of Bolivia, in spite of your climatics risks. The plots of quinoa present lower organic matter to 0.93%, humidity of the smaller earth to 12.9%, temperature of the earth for under 8.5 oC and pH lower to 8.0. The population of funguses in three types it has studied of earths that went: without farm (without entropic intervention, traditional and mechanized. The humid samples of the earth were gathered to a depth of 6 to 25 cm at random in zig-zag, these to be prosecuted by means of the method of seriate dilution and inoculated in plates with 0.5 mL and it is evaluated the colonies for UFC´s/g of earth, the genre of Penicilli-um spp., with major population of 65.1%, followed for Aspergillus spp., with 24,1% and Trichoderma spp., with minor great quality of 13,8% and the population average in UFC´s/g of earth it went of 1035.4 in with-out farm (without entropic intervention, 959.7 in traditional and 868.2 in the mechanized and the major population was presented in the month of February 1572.8 UFC/g of earth.

  1. Three dimensional strained semiconductors

    Science.gov (United States)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  2. Hamstring strain - aftercare

    Science.gov (United States)

    Pulled hamstring muscle; Sprain - hamstring ... There are 3 levels of hamstring strains: Grade 1 -- mild muscle strain or pull Grade 2 -- partial muscle tear Grade 3 -- complete muscle tear Recovery time depends ...

  3. Strain-Modulated Epitaxy

    National Research Council Canada - National Science Library

    Brown, April

    1999-01-01

    Strain-Modulated Epitaxy (SME) is a novel approach, invented at Georgia Tech, to utilize subsurface stressors to control strain and therefore material properties and growth kinetics in the material above the stressors...

  4. Methodology to measure strains at high temperatures using electrical strain gages with free filaments

    International Nuclear Information System (INIS)

    Atanazio Filho, Nelson N.; Gomes, Paulo T. Vida; Scaldaferri, Denis H.B.; Silva, Luiz L. da; Rabello, Emerson G.; Mansur, Tanius R.

    2013-01-01

    An experimental methodology used for strains measuring at high temperatures is show in this work. In order to do the measurements, it was used electric strain gages with loose filaments attached to a stainless steel 304 beam with specific cements. The beam has triangular shape and a constant thickness, so the strain is the same along its length. Unless the beam surface be carefully prepared, the strain gage attachment is not efficient. The showed results are for temperatures ranging from 20 deg C to 300 deg C, but the experimental methodology could be used to measure strains at a temperature up to 900 deg C. Analytical calculations based on solid mechanics were used to verify the strain gage electrical installation and the measured strains. At a first moment, beam deformations as a temperature function were plotted. After that, beam deformations with different weighs were plotted as a temperature function. The results shown allowed concluding that the experimental methodology is trustable to measure strains at temperatures up to 300 deg C. (author)

  5. Feasibility Study of Economics and Performance of Solar Photovoltaics at the Crazy Horse Landfill Site in Salinas, California. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

    Energy Technology Data Exchange (ETDEWEB)

    Stoltenberg, B.; Konz, C.; Mosey, G.

    2013-03-01

    The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Crazy Horse Landfill site in Salinas, California, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) was contacted to provide technical assistance for this project. The purpose of this report is to assess the site for a possible photovoltaic (PV) system installation and estimate the cost, performance, operation and maintenance requirements, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.

  6. Strain mapping near a triple junction in strained Ni-based alloy using EBSD and biaxial nanogauges

    Energy Technology Data Exchange (ETDEWEB)

    Clair, A. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS, Universite de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex (France); Foucault, M.; Calonne, O. [Areva ANP, Centre Technique Departement Corrosion-Chimie, 30 Bd de l' industrie, BP 181, 71205 Le Creusot (France); Lacroute, Y.; Markey, L.; Salazar, M.; Vignal, V. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS, Universite de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex (France); Finot, E., E-mail: Eric.Finot@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS, Universite de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex (France)

    2011-05-15

    Research highlights: > Surface strains measured using nanogauge were compared to the texture obtained by EBSD. > Statistics of the principal strain discern the grains according to the Schmid factor. > Strain hotspots were localized near a triple junction of alloy 600 under tensile loading. > Asymetrical profile of the GB strains is a criterion for surface cracking initiation. - Abstract: A key element for analyzing the crack initiation in strained polycrystalline alloys is the local quantification of the surface strain distribution according to the grain texture. Using electron backscattered diffraction, the local microstructure was determined to both localize a triple junction and deduce the local Schmid factors. Kernel average misorientation (KAM) was also used to map the areas of defect concentration. The maximum principal strain and the in-plane shear strain were quantified using the biaxial nanogauge. Distortions of the array of nanodots used as spot markers were analyzed near the triple junction. The crystallographic orientation and the surface strain were then investigated both statistically for each grain and locally at the grain boundaries. The superimposition of microstructure and strain maps allows the high strain gradient (reaching 3-fold the applied strain) to be localized at preferential grain boundaries near the triple junction. The Schmid factors and the KAM were compared to the maximum principal strain and the in-plane shear strain respectively. The polycrystalline deformation was attributable first to the rotation of some grains, followed by the elongation of all grains along their preferential activated slip systems.

  7. Solitary waves in morphogenesis: Determination fronts as strain-cued strain transformations among automatous cells

    Science.gov (United States)

    Cox, Brian N.; Landis, Chad M.

    2018-02-01

    We present a simple theory of a strain pulse propagating as a solitary wave through a continuous two-dimensional population of cells. A critical strain is assumed to trigger a strain transformation, while, simultaneously, cells move as automata to tend to restore a preferred cell density. We consider systems in which the strain transformation is a shape change, a burst of proliferation, or the commencement of growth (which changes the shape of the population sheet), and demonstrate isomorphism among these cases. Numerical and analytical solutions describe a strain pulse whose height does not depend on how the strain disturbance was first launched, or the rate at which the strain transformation is achieved, or the rate constant in the rule for the restorative cell motion. The strain pulse is therefore very stable, surviving the imposition of strong perturbations: it would serve well as a timing signal in development. The automatous wave formulation is simple, with few model parameters. A strong case exists for the presence of a strain pulse during amelogenesis. Quantitative analysis reveals a simple relationship between the velocity of the leading edge of the pulse in amelogenesis and the known speed of migration of ameloblast cells. This result and energy arguments support the depiction of wave motion as an automatous cell response to strain, rather than as a response to an elastic energy gradient. The theory may also contribute to understanding the determination front in somitogenesis, moving fronts of convergent-extension transformation, and mitotic wavefronts in the syncytial drosophila embryo.

  8. Mycobacterium tuberculosis strains exhibit differential and strain-specific molecular signatures in pulmonary epithelial cells.

    Science.gov (United States)

    Mvubu, Nontobeko Eunice; Pillay, Balakrishna; Gamieldien, Junaid; Bishai, William; Pillay, Manormoney

    2016-12-01

    Although pulmonary epithelial cells are integral to innate and adaptive immune responses during Mycobacterium tuberculosis infection, global transcriptomic changes in these cells remain largely unknown. Changes in gene expression induced in pulmonary epithelial cells infected with M. tuberculosis F15/LAM4/KZN, F11, F28, Beijing and Unique genotypes were investigated by RNA sequencing (RNA-Seq). The Illumina HiSeq 2000 platform generated 50 bp reads that were mapped to the human genome (Hg19) using Tophat (2.0.10). Differential gene expression induced by the different strains in infected relative to the uninfected cells was quantified and compared using Cufflinks (2.1.0) and MeV (4.0.9), respectively. Gene expression varied among the strains with the total number of genes as follows: F15/LAM4/KZN (1187), Beijing (1252), F11 (1639), F28 (870), Unique (886) and H37Rv (1179). A subset of 292 genes was commonly induced by all strains, where 52 genes were down-regulated while 240 genes were up-regulated. Differentially expressed genes were compared among the strains and the number of induced strain-specific gene signatures were as follows: F15/LAM4/KZN (138), Beijing (52), F11 (255), F28 (55), Unique (186) and H37Rv (125). Strain-specific molecular gene signatures associated with functional pathways were observed only for the Unique and H37Rv strains while certain biological functions may be associated with other strain signatures. This study demonstrated that strains of M. tuberculosis induce differential gene expression and strain-specific molecular signatures in pulmonary epithelial cells. Specific signatures induced by clinical strains of M. tuberculosis can be further explored for novel host-associated biomarkers and adjunctive immunotherapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Flexible piezotronic strain sensor.

    Science.gov (United States)

    Zhou, Jun; Gu, Yudong; Fei, Peng; Mai, Wenjie; Gao, Yifan; Yang, Rusen; Bao, Gang; Wang, Zhong Lin

    2008-09-01

    Strain sensors based on individual ZnO piezoelectric fine-wires (PFWs; nanowires, microwires) have been fabricated by a simple, reliable, and cost-effective technique. The electromechanical sensor device consists of a single electrically connected PFW that is placed on the outer surface of a flexible polystyrene (PS) substrate and bonded at its two ends. The entire device is fully packaged by a polydimethylsiloxane (PDMS) thin layer. The PFW has Schottky contacts at its two ends but with distinctly different barrier heights. The I- V characteristic is highly sensitive to strain mainly due to the change in Schottky barrier height (SBH), which scales linear with strain. The change in SBH is suggested owing to the strain induced band structure change and piezoelectric effect. The experimental data can be well-described by the thermionic emission-diffusion model. A gauge factor of as high as 1250 has been demonstrated, which is 25% higher than the best gauge factor demonstrated for carbon nanotubes. The strain sensor developed here has applications in strain and stress measurements in cell biology, biomedical sciences, MEMS devices, structure monitoring, and more.

  10. Molecular typing of Brucella melitensis endemic strains and differentiation from the vaccine strain Rev-1.

    Science.gov (United States)

    Noutsios, Georgios T; Papi, Rigini M; Ekateriniadou, Loukia V; Minas, Anastasios; Kyriakidis, Dimitrios A

    2012-03-01

    In the present study forty-four Greek endemic strains of Br. melitensis and three reference strains were genotyped by Multi locus Variable Number Tandem Repeat (ML-VNTR) analysis based on an eight-base pair tandem repeat sequence that was revealed in eight loci of Br. melitensis genome. The forty-four strains were discriminated from the vaccine strain Rev-1 by Restriction Fragment Length Polymorphism (RFLP) and Denaturant Gradient Gel Electrophoresis (DGGE). The ML-VNTR analysis revealed that endemic, reference and vaccine strains are genetically closely related, while most of the loci tested (1, 2, 4, 5 and 7) are highly polymorphic with Hunter-Gaston Genetic Diversity Index (HGDI) values in the range of 0.939 to 0.775. Analysis of ML-VNTRs loci stability through in vitro passages proved that loci 1 and 5 are non stable. Therefore, vaccine strain can be discriminated from endemic strains by allele's clusters of loci 2, 4, 6 and 7. RFLP and DGGE were also employed to analyse omp2 gene and reveled different patterns among Rev-1 and endemic strains. In RFLP, Rev-1 revealed three fragments (282, 238 and 44 bp), while endemic strains two fragments (238 and 44 bp). As for DGGE, the electrophoretic mobility of Rev-1 is different from the endemic strains due to heterologous binding of DNA chains of omp2a and omp2b gene. Overall, our data show clearly that it is feasible to genotype endemic strains of Br. melitensis and differentiate them from vaccine strain Rev-1 with ML-VNTR, RFLP and DGGE techniques. These tools can be used for conventional investigations in brucellosis outbreaks.

  11. Effects of the Strain Rate Sensitivity and Strain Hardening on the Saturated Impulse of Plates

    Directory of Open Access Journals (Sweden)

    Ling Zhu

    Full Text Available Abstract This paper studies the stiffening effects of the material strain rate sensitivity and strain hardening on the saturated impulse of elastic, perfectly plastic plates. Finite element (FE code ABAQUS is employed to simulate the elastoplastic response of square plates under rectangular pressure pulse. Rigid-plastic analyses for saturated impulse, which consider strain rate sensitivity and strain hardening, are conducted. Satisfactory agreement between the finite element models (FEM and predictions of the rigid-plastic analysis is obtained, which verifies that the proposed rigid-plastic methods are effective to solve the problem including strain rate sensitivity and strain hardening. The quantitative results for the scale effect of the strain rate sensitivity are given. The results for the stiffening effects suggest that two general stiffening factors n 1 and n 2, which characterizes the strain rate sensitivity and strain hardening effect, respectively can be defined. The saturated displacement is inversely proportional to the stiffening factors (i.e. n 1 and n 2 and saturated impulse is inversely proportional to the square roots of the stiffening factors (i.e. n 1 and n 2. Formulae for displacement and saturated impulse are proposed based on the empirical analysis.

  12. The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

    Science.gov (United States)

    Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

    2016-11-01

    The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

  13. Effect of strain rate and temperature at high strains on fatigue behavior of SAP alloys

    DEFF Research Database (Denmark)

    Blucher, J.T.; Knudsen, Per; Grant, N.J.

    1968-01-01

    Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased with decre......Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased...

  14. Genome-Wide Transcription Study of Cryptococcus neoformans H99 Clinical Strain versus Environmental Strains.

    Directory of Open Access Journals (Sweden)

    Elaheh Movahed

    Full Text Available The infection of Cryptococcus neoformans is acquired through the inhalation of desiccated yeast cells and basidiospores originated from the environment, particularly from bird's droppings and decaying wood. Three environmental strains of C. neoformans originated from bird droppings (H4, S48B and S68B and C. neoformans reference clinical strain (H99 were used for intranasal infection in C57BL/6 mice. We showed that the H99 strain demonstrated higher virulence compared to H4, S48B and S68B strains. To examine if gene expression contributed to the different degree of virulence among these strains, a genome-wide microarray study was performed to inspect the transcriptomic profiles of all four strains. Our results revealed that out of 7,419 genes (22,257 probes examined, 65 genes were significantly up-or down-regulated in H99 versus H4, S48B and S68B strains. The up-regulated genes in H99 strain include Hydroxymethylglutaryl-CoA synthase (MVA1, Mitochondrial matrix factor 1 (MMF1, Bud-site-selection protein 8 (BUD8, High affinity glucose transporter 3 (SNF3 and Rho GTPase-activating protein 2 (RGA2. Pathway annotation using DAVID bioinformatics resource showed that metal ion binding and sugar transmembrane transporter activity pathways were highly expressed in the H99 strain. We suggest that the genes and pathways identified may possibly play crucial roles in the fungal pathogenesis.

  15. Life Stress, Strain, and Deviance Across Schools: Testing the Contextual Version of General Strain Theory in China.

    Science.gov (United States)

    Zhang, Jinwu; Liu, Jianhong; Wang, Xin; Zou, Anquan

    2017-08-01

    General Strain Theory delineates different types of strain and intervening processes from strain to deviance and crime. In addition to explaining individual strain-crime relationship, a contextualized version of general strain theory, which is called the Macro General Strain Theory, has been used to analyze how aggregate variables influence aggregate and individual deviance and crime. Using a sample of 1,852 students (Level 1) nested in 52 schools (Level 2), the current study tests the Macro General Strain Theory using Chinese data. The results revealed that aggregate life stress and strain have influences on aggregate and individual deviance, and reinforce the individual stress-deviance association. The current study contributes by providing the first Macro General Strain Theory test based on Chinese data and offering empirical evidence for the multilevel intervening processes from strain to deviance. Limitations and future research directions are discussed.

  16. Strain Pattern in Supercooled Liquids

    Science.gov (United States)

    Illing, Bernd; Fritschi, Sebastian; Hajnal, David; Klix, Christian; Keim, Peter; Fuchs, Matthias

    2016-11-01

    Investigations of strain correlations at the glass transition reveal unexpected phenomena. The shear strain fluctuations show an Eshelby-strain pattern [˜cos (4 θ ) /r2 ], characteristic of elastic response, even in liquids, at long times. We address this using a mode-coupling theory for the strain fluctuations in supercooled liquids and data from both video microscopy of a two-dimensional colloidal glass former and simulations of Brownian hard disks. We show that the long-ranged and long-lived strain signatures follow a scaling law valid close to the glass transition. For large enough viscosities, the Eshelby-strain pattern is visible even on time scales longer than the structural relaxation time τ and after the shear modulus has relaxed to zero.

  17. [Is it possible to "cancel" aging process of cell cultures under optimal conditions for cultivation?].

    Science.gov (United States)

    Bozhkov, A I; Kovaleva, M K; Menzianova, N G

    2011-01-01

    The characteristics of the cells epigenotypes Dunaliella viridis Teod. in the process of chronological and replicative aging were investigated. By 40th day of accumulative cultivation (which coincided with the stationary growth phase) DNA content in the cells of Dunaliella viridis increased 2 times, triacylglycerides 3 times, beta-carotene and carbonyl proteins 2 times, RNA content decreased in comparison with cells in exponential growth phase, i. e., the 40th day of growth of culture forms the age-related epigenotype. 4 received subcultures were being transplanted during 2 years in mid-logarithmic growth phase (subculture-10), early stationary phase of growth (subculture-20), in the mid-stationary growth phase (subculture-30), and late stationary growth phase (subculture-40). It is shown that epigenotype of subculture-10 remained unchanged over 2 years of cultivation, i. e., it does not manifest replicative aging. At the same time, the subculture-20, although long enough (at least 40 passages), maintained epigenotype characteristic of young cultures, and showed age-related changes. Pronounced age-dependent changes of epigenotype in the course of cultivation were identified for subculture-30, and subculture-40 was characterized by unstable epigenotype. Thus, cultivation conditions determine the intensity of replicative aging in Dunaliella viridis.

  18. Different ways to die: cell death modes of the unicellular chlorophyte Dunaliella viridis exposed to various environmental stresses are mediated by the caspase-like activity DEVDase.

    Science.gov (United States)

    Jiménez, Carlos; Capasso, Juan M; Edelstein, Charles L; Rivard, Christopher J; Lucia, Scott; Breusegem, Sophia; Berl, Tomás; Segovia, María

    2009-01-01

    Programmed cell death is necessary for homeostasis in multicellular organisms and it is also widely recognized to occur in unicellular organisms. However, the mechanisms through which it occurs in unicells, and the enzymes involved within the final response is still the subject of heated debate. It is shown here that exposure of the unicellular microalga Dunaliella viridis to several environmental stresses, induced different cell death morphotypes, depending on the stimulus received. Senescent cells demonstrated classical and unambiguous apoptotic-like characteristics such as chromatin condensation, DNA fragmentation, intact organelles, and blebbing of the cell membrane. Acute heat shock caused general swelling and altered plasma membrane, but the presence of chromatin clusters and DNA strand breaks suggested a necrotic-like event. UV irradiated cells presented changes typical for necrosis, together with apoptotic characteristics resembling an intermediate cell-death phenotype termed aponecrosis-like. Cells subjected to hyperosmotic shock revealed chromatin spotting without DNA fragmentation, and extensive cytoplasmic swelling and vacuolization, comparable to a paraptotic-like cell death phenotype. Nitrogen-starved cells showed pyknosis, blebbing, and cytoplasmic consumption, indicating a similarity to autophagic/vacuolar-like cell death. The caspase-like activity DEVDase was measured by using the fluorescent substrate Ac-DEVD-AMC and antibodies against the human caspase-3 active enzyme cross-reacted with bands, the intensity of which paralleled the activity. All the environmental stresses tested produced a substantial increase in both DEVDase activity and protein levels. The irreversible caspase-3 inhibitor Z-DEVD-FMK completely inhibited the enzymatic activity whereas serine and aspartyl proteases inhibitors did not. These results show that cell death in D. viridis does not conform to a single pattern and that environmental stimuli may produce different types of

  19. Biological assay of attenuated strain NADL-2 and virulent strain NADL-8 of porcine parvovirus.

    Science.gov (United States)

    Mengeling, W L; Pejsak, Z; Paul, P S

    1984-11-01

    Attenuated strain NADL-2 and virulent strain NADL-8 of porcine parvovirus (PPV) were titrated in vivo and in vitro under similar conditions to provide a better understanding of some of the factors involved in virulence of PPV in causing maternal reproductive failure of swine. Both strains cause fetal death when they are injected directly into fetal fluids, but only strain NADL-8 does so when administered to pregnant swine. The strains were tested for their hemagglutinating activity (HA), median cell culture infective dose (CCID50), median fetal infective dose (FID50), and median fetal lethal dose (FLD50). The FID50 and FLD50 were determined by injecting virus directly into the amniotic fluid of fetuses in utero at 44 +/- 2 days of gestation and collecting the fetuses 15 +/- 1 days later. Both strains had an HA titer of 64, suggesting that there is a similar number of virions in stock preparations. However, other measurements differed markedly. The CCID50, FID50, and FLD50 were 10(5.5), 10(3.5), and 10(0.5), respectively, for strain NADL-2, and 10(4.5), 10(7.7), and 10(6.3), respectively, for strain NADL-8. Collectively, the values indicate that more than 10,000 times as much strain NADL-2 would need to reach the conceptus transplacentally to establish infection. These observations may help to explain the different consequences of oronasal exposure of pregnant swine to these strains of PPV.

  20. Haldane model under nonuniform strain

    Science.gov (United States)

    Ho, Yen-Hung; Castro, Eduardo V.; Cazalilla, Miguel A.

    2017-10-01

    We study the Haldane model under strain using a tight-binding approach, and compare the obtained results with the continuum-limit approximation. As in graphene, nonuniform strain leads to a time-reversal preserving pseudomagnetic field that induces (pseudo-)Landau levels. Unlike a real magnetic field, strain lifts the degeneracy of the zeroth pseudo-Landau levels at different valleys. Moreover, for the zigzag edge under uniaxial strain, strain removes the degeneracy within the pseudo-Landau levels by inducing a tilt in their energy dispersion. The latter arises from next-to-leading order corrections to the continuum-limit Hamiltonian, which are absent for a real magnetic field. We show that, for the lowest pseudo-Landau levels in the Haldane model, the dominant contribution to the tilt is different from graphene. In addition, although strain does not strongly modify the dispersion of the edge states, their interplay with the pseudo-Landau levels is different for the armchair and zigzag ribbons. Finally, we study the effect of strain in the band structure of the Haldane model at the critical point of the topological transition, thus shedding light on the interplay between nontrivial topology and strain in quantum anomalous Hall systems.

  1. Strain preservation of experimental animals: vitrification of two-cell stage embryos for multiple mouse strains.

    Science.gov (United States)

    Eto, Tomoo; Takahashi, Riichi; Kamisako, Tsutomu

    2015-04-01

    Strain preservation of experimental animals is crucial for experimental reproducibility. Maintaining complete animal strains, however, is costly and there is a risk for genetic mutations as well as complete loss due to disasters or illness. Therefore, the development of effective vitrification techniques for cryopreservation of multiple experimental animal strains is important. We examined whether a vitrification method using cryoprotectant solutions, P10 and PEPeS, is suitable for preservation of multiple inbred and outbred mouse strains. First, we investigated whether our vitrification method using cryoprotectant solutions was suitable for two-cell stage mouse embryos. In vitro development of embryos exposed to the cryoprotectant solutions was similar to that of fresh controls. Further, the survival rate of the vitrified embryos was extremely high (98.1%). Next, we collected and vitrified two-cell stage embryos of 14 mouse strains. The average number of embryos obtained from one female was 7.3-33.3. The survival rate of vitrified embryos ranged from 92.8% to 99.1%, with no significant differences among mouse strains. In vivo development did not differ significantly between fresh controls and vitrified embryos of each strain. For strain preservation using cryopreserved embryos, two offspring for inbred lines and one offspring for outbred lines must be produced from two-cell stage embryos collected from one female. The expected number of surviving fetuses obtained from embryos collected from one female of either the inbred or outbred strains ranged from 2.9 to 19.5. The findings of the present study indicated that this vitrification method is suitable for strain preservation of multiple mouse strains. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Colony Dimorphism in Bradyrhizobium Strains

    Science.gov (United States)

    Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

    1988-01-01

    Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

  3. Conduction band structure and electron mobility in uniaxially strained Si via externally applied strain in nanomembranes

    Energy Technology Data Exchange (ETDEWEB)

    Chen Feng [Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Euaruksakul, Chanan; Himpsel, F J; Lagally, Max G [University of Wisconsin-Madison, Madison, WI 53706 (United States); Liu Zheng; Liu Feng, E-mail: lagally@engr.wisc.edu [University of Utah, Salt Lake City, UT 84112 (United States)

    2011-08-17

    Strain changes the band structure of semiconductors. We use x-ray absorption spectroscopy to study the change in the density of conduction band (CB) states when silicon is uniaxially strained along the [1 0 0] and [1 1 0] directions. High stress can be applied to silicon nanomembranes, because their thinness allows high levels of strain without fracture. Strain-induced changes in both the sixfold degenerate {Delta} valleys and the eightfold degenerate L valleys are determined quantitatively. The uniaxial deformation potentials of both {Delta} and L valleys are directly extracted using a strain tensor appropriate to the boundary conditions, i.e., confinement in the plane in the direction orthogonal to the straining direction, which correspond to those of strained CMOS in commercial applications. The experimentally determined deformation potentials match the theoretical predictions well. We predict electron mobility enhancement created by strain-induced CB modifications.

  4. Produção de mudas de limão cravo em substrato com biofertilizante bovino irrigado com águas salinas Production of rangpur lemon seedlings in substrate with bovine biofertilizer irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Alex Matheus Rebequi

    2009-12-01

    Full Text Available Um experimento foi instalado no período de março a maio de 2008, em ambiente telado, para avaliar os efeitos da salinidade da água de irrigação e do biofertilizante bovino na formação de mudas de limão cravo. O substrato foi material dos primeiros 20 cm de um Argissolo Amarelo Distrófico não salino, com os tratamentos dispostos em esquema fatorial 5 x 2 com seis repetições, referente a cinco valores de condutividades elétrica da água de irrigação (0,5; 1,0; 2,0; 3,0 e 4,0 dS.m-1, obtidos pela diluição de uma água fortemente salina (14,3 dS.m-1 com água não salina (0,5 dS.m-1, em solo sem e com biofertilizante comum, diluído em água na proporção de 1:1 aplicado ao nível de 10% do volume do substrato, um dia antes da semeadura. Pelos resultados, se constatou superioridade dos dados obtidos nos tratamentos com o biofertilizante em relação aos dos tratamentos sem o respectivo insumo.One experiment was developed during the period from March to May of 2008 in a canvassed shelter to evaluate the effects of saline water and bovine biofertilizer on seedling formation of rangpur lemon. The substrate used was composed by soil at 20 cm depth of a non saline yellow distrofic Oxisoil, with treatments distributed in a factorial arrangement 5 x 2 with six repetitions, referring to water electrical conductivity (0.5, 1.0, 2.0, 3.0 e 4.0 dS.m-1 obtained by dilution of saline water (14.3 dS.m-1 with non saline water (0.5 dS.m-1 in soil with and without biofertilizer diluted in water 1:1 proportion applied in 10% of substrate volume, one day before sowing. According to results, it was observed a superiority of data from treatments with biofertilizer in relation to those without this product.

  5. Studies on Drosophila radiosensitive strains

    International Nuclear Information System (INIS)

    Varentsova, E.P.; Zakharov, I.A.

    1976-01-01

    45 of radiosensitive strains of Drosophila melanogaster were isolated by Curly/Lobe technique after EMS treatment of Livadia population males. The lethality of non-Curly late larvae after gamma-irradiation (4000r) characterized radiosensitivity strains. Most of them exhibited higher frequency of the spontaneous dominant lethals (up to 69%). The males of 6 strains were semi-sterile. 5 of these strains exhibited higher frequency of X-chromosome non-disjunction

  6. Segregation of genes from donor strain during the production of recombinant congenic strains.

    Science.gov (United States)

    van Zutphen, L F; Den Bieman, M; Lankhorst, A; Demant, P

    1991-07-01

    Recombinant congenic strains (RCS) constitute a set of inbred strains which are designed to dissect the genetic control of multigenic traits, such as tumour susceptibility or disease resistance. Each RCS contains a small fraction of the genome of a common donor strain, while the majority of genes stem from a common background strain. We tested at two stages of the inbreeding process in 20 RCS, derived from BALB/cHeA and STS/A, to see whether alleles from the STS/A donor strain are distributed over the RCS in a ratio as would theoretically be expected. Four marker genes (Pep-3; Pgm-1; Gpi-1 and Es-3) located at 4 different chromosomes were selected and the allelic distribution was tested after 3-4 and after 12 generations of inbreeding. The data obtained do not significantly deviate from the expected pattern, thus supporting the validity of the concept of RCS.

  7. A new strain gage method for measuring the contractile strain ratio of Zircaloy tubing

    International Nuclear Information System (INIS)

    Hwang, S.K.; Sabol, G.P.

    1988-01-01

    An improved strain gage method for determining the contractile strain ratio (CSR) of Zircaloy tubing was developed. The new method consists of a number of load-unload cyclings at approximately 0.2% plastic strain interval. With this method the CSR of Zircaloy-4 tubing could be determined accurately because it was possible to separate the plastic strains from the elastic strain involvement. The CSR values determined by use of the new method were in good agreement with those calculated from conventional post-test manual measurements. The CSR of the tubing was found to decrease with the amount of deformation during testing because of uneven plastic flow in the gage section. A new technique of inscribing gage marks by use of a YAG laser is discussed. (orig.)

  8. Strain localization band width evolution by electronic speckle pattern interferometry strain rate measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guelorget, Bruno [Institut Charles Delaunay-LASMIS, Universite de technologie de Troyes, FRE CNRS 2848, 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)], E-mail: bruno.guelorget@utt.fr; Francois, Manuel; Montay, Guillaume [Institut Charles Delaunay-LASMIS, Universite de technologie de Troyes, FRE CNRS 2848, 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)

    2009-04-15

    In this paper, electronic speckle pattern interferometry strain rate measurements are used to quantify the width of the strain localization band, which occurs when a sheet specimen is submitted to tension. It is shown that the width of this band decreases with increasing strain. Just before fracture, this measured width is about five times wider than the shear band and the initial sheet thickness.

  9. Thermal strain measurement of EAST W/Cu divertor structure using electric resistance strain gauges

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xingli [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Wang, Wanjing, E-mail: wjwang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Wang, Jichao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Wei, Ran; Sun, Zhaoxuan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Li, Qiang; Xie, Chunyi [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Chen, Hong-En; Wang, Kaiqiang; Wu, Lei; Chen, Zhenmao [State Key Lab for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Hefei Center for Physical Science and Technology, Hefei, 230022 (China); Hefei Science Center of Chinese Academy of Sciences, Hefei, 230027 (China)

    2016-12-15

    Highlights: • To understand the service behavior of W/Cu divertor, an electrical resistance strain gauge system had been introduced in a thermal strain measurement experiment. • The measurement system successfully finished the experiment and obtained valued thermal strain data. • Two thermomechanical analyses had also been carried out and compared with the measurement results. • Experiment results corresponded well to simulations and threw a light upon the failure of W/Cu divertor in the previous baking tests. - Abstract: W/Cu divertor has complex structure and faces extreme work environment in EAST Tokamak device. To measure its thermal strain shall be a valued way to understand its service behavior and then optimize its design and manufacturing process. This work presents a preliminary study on measuring thermal strain of EAST W/Cu divertor structure using electric resistance strain gauges. Eight gauges had been used in the experiment and the heating temperature had been set to 230 °C with respect to the work temperature. To realize the measuring experiment, an appropriate fixing method of gauges in divertor narrow spaces had been taken and tested, which could not only withstand high temperature but also had no damage to the divertor sample. The measurement results were that three gauges showed positive strain while other three showed negative strain after having been compensated, which corresponded to tensile stress and compressed stress respectively. Two thermomechanical simulations had also been carried out and used for comparing with the experiment.

  10. Trocas gasosas e teores de minerais no feijão-de-corda irrigado com água salina em diferentes estádios Gas exchange and mineral concentration in cowpea irrigated with saline water at different stages

    Directory of Open Access Journals (Sweden)

    Antonia L. R. Neves

    2009-12-01

    Full Text Available Realizou-se este trabalho com o objetivo de estudar os efeitos da aplicação de água salina nos diferentes estádios de desenvolvimento de plantas de feijão-de-corda sobre as trocas gasosas, o crescimento e os teores de minerais. O experimento foi conduzido no campo e obedeceu o delineamento em blocos ao acaso, com cinco tratamentos e cinco repetições. Os tratamentos utilizados foram: T1 - água do poço (CEa de 0,8 dS m-1 durante todo o ciclo (controle; T2 - água salina (CEa de 5,0 dS m-1 durante todo o ciclo; T3, T4 e T5 - água salina de 0 a 22, de 23 a 42 e de 43 a 62 dias após o plantio (DAP, respectivamente. As plantas dos tratamentos T3, T4 e T5 foram irrigadas com água do poço nas demais fases do ciclo. Realizaram-se, ao longo do ciclo da cultura, medições de trocas gasosas e se determinaram a produção de matéria seca e os teores de Na+, Cl-, K+, Ca2+, N e P. Os tratamentos T2 e T3 em relação ao T1 (controle, reduziram as taxas de fotossíntese e transpiração e as taxas de crescimento vegetativo e provocaram acúmulo, especialmente de Na+ e Cl-, porém se verificou, nas plantas do T3, recuperação de todas essas variáveis ao final do ciclo da cultura. As alterações no acúmulo de Na+ e Cl- nas plantas dos tratamentos T4 e T5 não foram suficientes para provocar efeitos significativos nas trocas gasosas nem nas taxas de crescimento da cultura, em comparação com as plantas do T1.The objective of this paper was to evaluate the effect of irrigation with saline water, applied at different development stages of cowpea, on gas exchange, growth and nutrient concentration. The experiment was set up in the field, in a completely randomized block design, with five treatments and five repetitions. The treatments studied were: T1 - Groundwater with electrical conductivity (ECw of 0.8 dS m-1 during the whole crop cycle (control; T2 - saline water (ECw = 5.0 dS m-1 during the whole crop cycle; T3, T4 and T5 - saline water from 0

  11. Noninvasive characterization of carotid plaque strain.

    Science.gov (United States)

    Khan, Amir A; Sikdar, Siddhartha; Hatsukami, Thomas; Cebral, Juan; Jones, Michael; Huston, John; Howard, George; Lal, Brajesh K

    2017-06-01

    Current risk stratification of internal carotid artery plaques based on diameter-reducing percentage stenosis may be unreliable because ischemic stroke results from plaque disruption with atheroembolization. Biomechanical forces acting on the plaque may render it vulnerable to rupture. The feasibility of ultrasound-based quantification of plaque displacement and strain induced by hemodynamic forces and their relationship to high-risk plaques have not been determined. We studied the feasibility and reliability of carotid plaque strain measurement from clinical B-mode ultrasound images and the relationship of strain to high-risk plaque morphology. We analyzed carotid ultrasound B-mode cine loops obtained in patients with asymptomatic ≥50% stenosis during routine clinical scanning. Optical flow methods were used to quantify plaque motion and shear strain during the cardiac cycle. The magnitude (maximum absolute shear strain rate [MASSR]) and variability (entropy of shear strain rate [ESSR] and variance of shear strain rate [VSSR]) of strain were combined into a composite shear strain index (SSI), which was assessed for interscan repeatability and correlated with plaque echolucency. Nineteen patients (mean age, 70 years) constituting 36 plaques underwent imaging; 37% of patients (n = 7) showed high strain (SSI ≥0.5; MASSR, 2.2; ESSR, 39.7; VSSR, 0.03) in their plaques; the remaining clustered into a low-strain group (SSI routine B-mode imaging using clinical ultrasound machines. High plaque strain correlates with known high-risk echolucent morphology. Strain measurement can complement identification of patients at high risk for plaque disruption and stroke. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  12. Revealing differences in metabolic flux distributions between a mutant strain and its parent strain Gluconacetobacter xylinus CGMCC 2955.

    Directory of Open Access Journals (Sweden)

    Cheng Zhong

    Full Text Available A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955 using DEC (diethyl sulfate and LiCl. The highest bacterial cellulose production for this mutant was obtained at about 11.75 g/L, which was an increase of 62% compared with that by the parent strain. In contrast, gluconic acid (the main byproduct concentration was only 5.71 g/L for mutant strain, which was 55.7% lower than that of parent strain. Metabolic flux analysis indicated that 40.1% of the carbon source was transformed to bacterial cellulose in mutant strain, compared with 24.2% for parent strain. Only 32.7% and 4.0% of the carbon source were converted into gluconic acid and acetic acid in mutant strain, compared with 58.5% and 9.5% of that in parent strain. In addition, a higher flux of tricarboxylic acid (TCA cycle was obtained in mutant strain (57.0% compared with parent strain (17.0%. It was also indicated from the flux analysis that more ATP was produced in mutant strain from pentose phosphate pathway (PPP and TCA cycle. The enzymatic activity of succinate dehydrogenase (SDH, which is one of the key enzymes in TCA cycle, was 1.65-fold higher in mutant strain than that in parent strain at the end of culture. It was further validated by the measurement of ATPase that 3.53-6.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain.

  13. Mumps Hoshino and Torii vaccine strains were distinguished from circulating wild strains.

    Science.gov (United States)

    Sawada, Akihito; Yamaji, Yoshiaki; Nakayama, Tetsuo

    2013-06-01

    Aseptic meningitis and acute parotitis have been observed after mumps vaccination. Mumps outbreaks have been reported in Japan because of low vaccine coverage, and molecular differentiation is required to determine whether these cases are vaccine associated. RT-nested PCR was performed in the small hydrophobic gene region, and viruses were differentiated by restriction fragment length polymorphism assay. A total of 584 nucleotides were amplified. The PCR product of the Hoshino strain was cut into two fragments (313 and 271 nucleotides) by MfeI; that of the Torii strain was digested with EcoT22I, resulting in 332- and 252-nucleotide fragments. Both strains were genotype B and had an XbaI site, resulting in two fragments: 299 and 285 nucleotides. Current circulating wild types were cut only by XbaI or MfeI. However, the MfeI site of the wild types was different from that of the Hoshino strain, resulting in 451- and 133-nucleotide fragments. Using three restriction enzymes, two mumps vaccine strains were distinguished from wild types, and this separation was applied to the identification of vaccine-related adverse events.

  14. An Embeddable Strain Sensor with 30 Nano-Strain Resolution Based on Optical Interferometry

    Directory of Open Access Journals (Sweden)

    Chen Zhu

    2018-04-01

    Full Text Available A cost-effective, robust and embeddable optical interferometric strain sensor with nanoscale strain resolution is presented in this paper. The sensor consists of an optical fiber, a quartz rod with one end coated with a thin gold layer, and two metal shells employed to transfer the strain and orient and protect the optical fiber and the quartz rod. The optical fiber endface, combining with the gold-coated surface, forms an extrinsic Fabry–Perot interferometer. The sensor was firstly calibrated, and the result showed that our prototype sensor could provide a measurement resolution of 30 nano-strain (nε and a sensitivity of 10.01 µε/µm over a range of 1000 µε. After calibration of the sensor, the shrinkage strain of a cubic brick of mortar in real time during the drying process was monitored. The strain sensor was compared with a commercial linear variable displacement transducer, and the comparison results in four weeks demonstrated that our sensor had much higher measurement resolution and gained more detailed and useful information. Due to the advantages of the extremely simple, robust and cost-effective configuration, it is believed that the sensor is significantly beneficial to practical applications, especially for structural health monitoring.

  15. An ultrasensitive strain sensor with a wide strain range based on graphene armour scales.

    Science.gov (United States)

    Yang, Yi-Fan; Tao, Lu-Qi; Pang, Yu; Tian, He; Ju, Zhen-Yi; Wu, Xiao-Ming; Yang, Yi; Ren, Tian-Ling

    2018-06-12

    An ultrasensitive strain sensor with a wide strain range based on graphene armour scales is demonstrated in this paper. The sensor shows an ultra-high gauge factor (GF, up to 1054) and a wide strain range (ε = 26%), both of which present an advantage compared to most other flexible sensors. Moreover, the sensor is developed by a simple fabrication process. Due to the excellent performance, this strain sensor can meet the demands of subtle, large and complex human motion monitoring, which indicates its tremendous application potential in health monitoring, mechanical control, real-time motion monitoring and so on.

  16. Genotoxic and cytotoxic effects of ZnO nanoparticles for Dunaliella tertiolecta and comparison with SiO2 and TiO2 effects at population growth inhibition levels.

    Science.gov (United States)

    Schiavo, S; Oliviero, M; Miglietta, M; Rametta, G; Manzo, S

    2016-04-15

    The increasing use of oxide nanoparticles (NPs) in commercial products has intensified the potential release into the aquatic environment where algae represent the basis of the trophic chain. NP effects upon algae population growth were indeed already reported in literature, but the concurrent effects at cellular and genomic levels are still largely unexplored. Our work investigates the genotoxic (by COMET assay) and cytotoxic effects (by qualitative ROS production and cell viability) of ZnO nanoparticles toward marine microalgae Dunaliella tertiolecta. A comparison at defined population growth inhibition levels (i.e. 50% Effect Concentration, EC50, and No Observed Effect Concentration, NOEC) with SiO2 and TiO2 genotoxic effects and previously investigated cytotoxic effects (Manzo et al., 2015) was performed in order to elucidate the possible diverse mechanisms leading to algae growth inhibition. After 72h exposure, ZnO particles act firstly at the level of cell division inhibition (EC50: 2mg Zn/L) while the genotoxic action is evident only starting from 5mg Zn/L. This outcome could be ascribable mainly to the release of toxic ions from the aggregate of ZnO particle in the proximity of cell membrane. In the main, at EC50 and NOEC values for ZnO NPs showed the lowest cytotoxic and genotoxic effect with respect to TiO2 and SiO2. Based on Mutagenic Index (MI) the rank of toxicity is actually: TiO2>SiO2>ZnO with TiO2 and SiO2 that showed similar MI values at both NOEC and EC50 concentrations. The results presented herein suggest that up to TiO2 NOEC (7.5mg/L), the algae DNA repair mechanism is efficient and the DNA damage does not result in an evident algae population growth inhibition. A similar trend for SiO2, although at lower effect level with respect to TiO2, is observable. The comparison among all the tested nanomaterial toxicity patterns highlighted that the algae population growth inhibition occurred through pathways specific for each NP also related to their

  17. Strain rate measurement by Electronic Speckle Pattern Interferometry: A new look at the strain localization onset

    International Nuclear Information System (INIS)

    Guelorget, Bruno; Francois, Manuel; Vial-Edwards, Cristian; Montay, Guillaume; Daniel, Laurent; Lu, Jian

    2006-01-01

    In-plane Electronic Speckle Pattern Interferometry has been successfully used during tensile testing of semi-hard copper sheets in order to measure the strain rate. On one hand, heterogeneity in strain rate field has been found before the maximum of the tensile force (ε t ≅ 19.4 and 25.4%, respectively). Thus, a localization phenomenon occurs before the classic Considere's criterion (dF = 0) for the diffuse neck initiation. On the other hand, strain rate measurement before fracture shows the moment where one of the two slip band systems becomes predominant, then strain concentrates in a small area, the shear band. Uncertainty evaluation has been carried out, which shows a very good accuracy of the total strain and the strain rate measurements

  18. Strain rate measurement by Electronic Speckle Pattern Interferometry: A new look at the strain localization onset

    Energy Technology Data Exchange (ETDEWEB)

    Guelorget, Bruno [Universite de Technologie de Troyes (UTT), Laboratoire des Systemes Mecaniques et d' ingenierie Simultanee (LASMIS, CNRS FRE 2719), 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)]. E-mail: bruno.guelorget@utt.fr; Francois, Manuel [Universite de Technologie de Troyes (UTT), Laboratoire des Systemes Mecaniques et d' ingenierie Simultanee (LASMIS, CNRS FRE 2719), 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France); Vial-Edwards, Cristian [Departemento de Ingenieria Mecanica y Metalurgica, Pontificia Universidad Catolica de Chile, Vicuna Mackenna 4860, 6904411 Santiago (Chile); Montay, Guillaume [Universite de Technologie de Troyes (UTT), Laboratoire des Systemes Mecaniques et d' ingenierie Simultanee (LASMIS, CNRS FRE 2719), 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France); Daniel, Laurent [Universite de Technologie de Troyes (UTT), Laboratoire des Systemes Mecaniques et d' ingenierie Simultanee (LASMIS, CNRS FRE 2719), 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France); Lu, Jian [Universite de Technologie de Troyes (UTT), Laboratoire des Systemes Mecaniques et d' ingenierie Simultanee (LASMIS, CNRS FRE 2719), 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)

    2006-01-15

    In-plane Electronic Speckle Pattern Interferometry has been successfully used during tensile testing of semi-hard copper sheets in order to measure the strain rate. On one hand, heterogeneity in strain rate field has been found before the maximum of the tensile force ({epsilon} {sup t} {approx_equal} 19.4 and 25.4%, respectively). Thus, a localization phenomenon occurs before the classic Considere's criterion (dF = 0) for the diffuse neck initiation. On the other hand, strain rate measurement before fracture shows the moment where one of the two slip band systems becomes predominant, then strain concentrates in a small area, the shear band. Uncertainty evaluation has been carried out, which shows a very good accuracy of the total strain and the strain rate measurements.

  19. Determination of 54 pesticides in waters of the Iberian Douro River estuary and risk assessment of environmentally relevant mixtures using theoretical approaches and Artemia salina and Daphnia magna bioassays.

    Science.gov (United States)

    Cruzeiro, Catarina; Amaral, Sofia; Rocha, Eduardo; Rocha, Maria João

    2017-11-01

    As a case study, the estuary of the international Douro River (Iberian Peninsula) was sampled over a year (2010) at six sampling sites to determine the presence of 56 pesticides of different categories (insecticides, herbicides, and fungicides). 96% of measured pesticides were detected in 79% of the quantified samples. Individual average pesticide concentrations ranged from 39 to 1 265ng/L, indicating a ubiquitous presence of the selected compounds; moreover, twelve pesticides were above the 2013/39/EU Directive limits. Due to its highly impacted profile, a theoretical hazard assessment was done considering the average and maximum environmental mixtures of all measured pesticides to identify the most sensitive trophic level. For both environmental mixtures, the theoretical approach suggested that invertebrates were the most sensitive group. Therefore, short-time exposure assays using both invertebrates Artemia salina and Daphnia magna, were done using the referred mixtures. Data demonstrated significant toxic effects ─ high mortality rate and abnormal swimming behaviour ─ of the exposed animals. Both approaches (theoretical and experimental) support the analytical results, alerting for an intervention on this estuarine environment and of other comparable. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Mechanical strength model for plastic bonded granular materials at high strain rates and large strains

    International Nuclear Information System (INIS)

    Browning, R.V.; Scammon, R.J.

    1998-01-01

    Modeling impact events on systems containing plastic bonded explosive materials requires accurate models for stress evolution at high strain rates out to large strains. For example, in the Steven test geometry reactions occur after strains of 0.5 or more are reached for PBX-9501. The morphology of this class of materials and properties of the constituents are briefly described. We then review the viscoelastic behavior observed at small strains for this class of material, and evaluate large strain models used for granular materials such as cap models. Dilatation under shearing deformations of the PBX is experimentally observed and is one of the key features modeled in cap style plasticity theories, together with bulk plastic flow at high pressures. We propose a model that combines viscoelastic behavior at small strains but adds intergranular stresses at larger strains. A procedure using numerical simulations and comparisons with results from flyer plate tests and low rate uniaxial stress tests is used to develop a rough set of constants for PBX-9501. Comparisons with the high rate flyer plate tests demonstrate that the observed characteristic behavior is captured by this viscoelastic based model. copyright 1998 American Institute of Physics

  1. A strain gauge

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates to a strain gauge of a carrier layer and a meandering measurement grid (101) positioned on the carrier layer, wherein the measurement grid comprises a number of measurement grid sections placed side by side with gaps in between, and a number of end loops (106) interconnecting...... relates to a method for manufacturing a strain gauge as mentioned above....

  2. Origin of the Strain Sensitivity for an Organic Heptazole Thin-Film and Its Strain Gauge Application

    Science.gov (United States)

    Bae, Heesun; Jeon, Pyo Jin; Park, Ji Hoon; Lee, Kimoon

    2018-04-01

    The authors report on the origin of the strain sensitivity for an organic C26H16N2 (heptazole) thinfilm and its application for the detection of tensile strain. From the electrical characterization on the thin-film transistor adopting a heptazole channel, heptazole film exhibits p-channel conduction with a relatively low value of field-effect mobility (0.05 cm2/Vs), suggesting a hopping conduction behavior via hole carriers. By analyzing the strain and temperature dependences of the electrical conductivity, we reveal that the electrical conduction for a heptazole thin-film is dominated by the variable range hopping process with quite a large energy separation (224.9 meV) between the localized states under a relatively long attenuation length (10.46 Å). This indicates that a change in the inter-grain spacing that is much larger than the attenuation length is responsible for the reversible modification of electrical conductivity depending on strain for the heptazole film. By utilizing our heptazole thin-film both as a strain sensitive passive resistor and an active semiconducting channel layer, we can achieve a strain gauge device exhibiting reversible endurance for tensile strains up to 2.12%. Consequently, this study advances the understanding of the fundamental strain sensing mechanism in a heptazole thin-film toward finding a promise material with a strain gauge for applications as potential flexible devices and/or wearable electronics.

  3. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...... to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

  4. Dengue antiviral activity of polar extract from Melochia umbellata (Houtt) Stapf var. Visenia

    Science.gov (United States)

    Hariani Soekamto, Nunuk; Liong, S.; Fauziah, S.; Wahid, I.; Firdaus; Taba, P.; Ahmad, F.

    2018-03-01

    A research on the dengue antiviral activity test on the polar bark extract of M. umbelatta (Houtt.) Stapf var. Vicenia have been done to determine the relation to its activity againts brine shrimp Artemia salina. The bark was extracted by maceration with n-hexane, chloroform, and ethylacetate. The activity of the ethyl acetate extract was then tested against A. salina and dengue virus. It was found that the ethyl acetate extract was active to A. salina with the LC50 value of 101.66 μg/mL and also very active to dengue virus with the IC50 value of 1.67μg/mL. It is clear that the toxicity to brine shrimp A. salina has a positive correlation with the dengue anti virus.

  5. Strain-controlled nonvolatile magnetization switching

    Science.gov (United States)

    Geprägs, S.; Brandlmaier, A.; Brandt, M. S.; Gross, R.; Goennenwein, S. T. B.

    2014-11-01

    We investigate different approaches towards a nonvolatile switching of the remanent magnetization in single-crystalline ferromagnets at room temperature via elastic strain using ferromagnetic thin film/piezoelectric actuator hybrids. The piezoelectric actuator induces a voltage-controllable strain along different crystalline directions of the ferromagnetic thin film, resulting in modifications of its magnetization by converse magnetoelastic effects. We quantify the magnetization changes in the hybrids via ferromagnetic resonance spectroscopy and superconducting quantum interference device magnetometry. These measurements demonstrate a significant strain-induced change of the magnetization, limited by an inefficient strain transfer and domain formation in the particular system studied. To overcome these obstacles, we address practicable engineering concepts and use a model to demonstrate that a strain-controlled, nonvolatile magnetization switching should be possible in appropriately engineered ferromagnetic/piezoelectric actuator hybrids.

  6. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf Strain e strain rate por meio de ecocardiogratia speckle traking bidimensional em um lobo-guará

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.A obtenção de parâmetros cardiovasculares em animais selvagens são importantes de serem avaliados, assim como em animais de companhia, para a obtenção da função miocárdica e determinação precoce de alterações cardíacas que poderiam evoluir para insuficiência cardíaca . A ecocardiografia speckle tracking (2D STE é uma ferramenta nova que tem sido utilizada em medicina veterinária, a qual tem demonstrado várias vantagens quanto ao seu uso, como a independência do ângulo de insonação e a possibilidade de se obter o diagnóstico precoce de altera

  7. Failure strains and proposed limit strains for an reactor pressure vessel under severe accident conditions

    International Nuclear Information System (INIS)

    Krieg, R.

    2005-01-01

    The local failure strains of essential design elements of a reactor vessel are investigated. The size influence of the structure is of special interest. Typical severe accident conditions including elevated temperatures and dynamic loads are considered. The main part of work consists of test families with specimens under uniaxial and biaxial load. Within one test family the specimen geometry and the load conditions are similar, but the size is varied up to reactor dimensions. Special attention is given to geometries with a hole or a notch causing non-uniform stress and strain distributions typical for the reactor vessel. A key problem is to determine the local failure strain. Here suitable methods had to be developed including the so-called 'vanishing gap method', and the 'forging die method'. They are based on post-test geometrical measurements of the fracture surfaces and reconstructions of the related strain fields using finite element models. The results indicate that stresses versus dimensionless deformations are approximately size independent up to failure for specimens of similar geometry under similar load conditions. Local failure strains could be determined. The values are rather high and size dependent. Statistical evaluation allow the proposal of limit strains which are also size dependent. If these limit strains are not exceeded, the structures will not fracture

  8. General Strain Theory and Delinquency: Focusing on the Influences of Key Strain Characteristics on Delinquency

    Science.gov (United States)

    Moon, Byongook; Blurton, David; McCluskey, John D.

    2008-01-01

    The study examines the effects of recent, older, and chronic strains and of perceived injustice of strain on delinquency, sampling 777 Korean youth. Seven key strains most likely leading to delinquency, some of which were often overlooked in previous research, were included, and these are family conflict, parental punishment, teachers' punishment,…

  9. Enzyme markers in inbred rat strains: genetics of new markers and strain profiles.

    Science.gov (United States)

    Adams, M; Baverstock, P R; Watts, C H; Gutman, G A

    1984-08-01

    Twenty-six inbred strains of the laboratory rat (Rattus norvegicus) were examined for electrophoretic variation at an estimated 97 genetic loci. In addition to previously documented markers, variation was observed for the enzymes aconitase, aldehyde dehydrogenase, and alkaline phosphatase. The genetic basis of these markers (Acon-1, Ahd-2, and Akp-1) was confirmed. Linkage analysis between 35 pairwise comparisons revealed that the markers Fh-1 and Pep-3 are linked. The strain profiles of the 25 inbred strains at 11 electrophoretic markers are given.

  10. Effects of gauge volume on pseudo-strain induced in strain measurement using time-of-flight neutron diffraction

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi; Harjo, Stefanus; Abe, Jun; Xu, Pingguang; Aizawa, Kazuya; Akita, Koichi

    2013-01-01

    Spurious or pseudo-strains observed in time-of-flight (TOF) neutron diffraction due to neutron attenuation, surface-effects and a strain distribution within the gauge volume were investigated. Experiments were carried out on annealed and bent ferritic steel bars to test these effects. The most representative position in the gauge volume corresponds to the neutron-weighted center of gravity (ncog), which takes into account variations in intensity within the gauge volume due to neutron attenuation and/or absence of material in the gauge volume. The average strain in the gauge volume was observed to be weighted towards the ncog position but following an increase in the size of the gauge volume the weighted average strain was changed because of the change in the ncog position when a strain gradient appeared within the gauge volume. On the other hand, typical pseudo-strains, which are well known, did appear in through-surface strain measurements when the gauge volume was incompletely filled by the sample. Tensile pseudo-strains due to the surface-effect increased near the sample surface and exhibited a similar trend regardless of the size of the gauge volume, while the pseudo-strains increased faster for the smaller gauge volume. Furthermore, a pseudo-strain due to a change in the ncog position was observed even when the gauge volume was perfectly filled in the sample, and it increased with an increase in the size of the gauge volume. These pseudo-strains measured were much larger than those simulated by the conventional modeling, whereas they were simulated by taking into account an incident neutron beam divergence additionally in the model. Therefore, the incident divergence of the incident neutron beam must be carefully designed to avoid pseudo-strains in time-of-flight neutron diffractometry

  11. A wide extent of inter-strain diversity in virulent and vaccine strains of alphaherpesviruses.

    Science.gov (United States)

    Szpara, Moriah L; Tafuri, Yolanda R; Parsons, Lance; Shamim, S Rafi; Verstrepen, Kevin J; Legendre, Matthieu; Enquist, L W

    2011-10-01

    Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1) and 2, and varicella zoster virus (VZV). These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV), causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine strain Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine strain. We find many previously unknown coding differences between PRV Bartha and the virulent strains, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-strain variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs), a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between strains. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between strains. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV strain, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit limited sequence

  12. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  13. Bacteriocin-like inhibitory activities of seven Lactobacillus delbrueckii subsp. bulgaricus strains against antibiotic susceptible and resistant Helicobacter pylori strains.

    Science.gov (United States)

    Boyanova, L; Gergova, G; Markovska, R; Yordanov, D; Mitov, I

    2017-12-01

    The aim of the study was to detect anti-Helicobacter pylori activity of seven Lactobacillus delbrueckii subsp. bulgaricus (GLB) strains by four cell-free supernatant (CFS) types. Activity of non-neutralized and non-heat-treated (CFSs1), non-neutralized and heat-treated (CFSs2), pH neutralized, catalase-treated and non-heat-treated (CFSs3), or neutralized, catalase- and heat-treated (CFSs4) CFSs against 18 H. pylori strains (11 of which with antibiotic resistance) was evaluated. All GLB strains produced bacteriocin-like inhibitory substances (BLISs), the neutralized CFSs of two GLB strains inhibited >81% of test strains and those of four GLB strains were active against >71% of antibiotic resistant strains. Two H. pylori strains were BLIS resistant. The heating did not reduce the CFS activity. Briefly, all GLB strains evaluated produced heat-stable BLISs, although GLB and H. pylori strain susceptibility patterns exhibited differences. Bacteriocin-like inhibitory substance activity can be an advantage for the probiotic choice for H. pylori infection control. In this study, anti-Helicobacter pylori activity of seven Lactobacillus delbrueckii subsp. bulgaricus (GLB) strains was evaluated by four cell-free supernatant (CFS) types. The GLB strains produced heat-stable bacteriocin-like inhibitory substances (BLISs) with a strong anti-H. pylori activity and some neutralized, catalase- and heat-treated CFSs inhibited >83% of the test strains. Bacteriocin-like inhibitory substance production of GLB strains can render them valuable probiotics in the control of H. pylori infection. © 2017 The Society for Applied Microbiology.

  14. Pin clad strains in Phenix

    International Nuclear Information System (INIS)

    Languille, A.

    1979-07-01

    The Phenix reactor has operated for 4 years in a satisfactory manner. The first 2 sub-assembly loadings contained pins clad in solution treated 316. The principal pin strains are: diametral strain (swelling and irradiation creep), ovality and spiral bending of the pin (interaction of wire and pin cluster and wrapper). A pin cluster irradiated to a dose of 80 dpa F reached a pin diameter strain of 5%. This strain is principally due to swelling (low fission gas pressure). The principal parameters governing the swelling are instantaneous dose, time and temperature for a given type of pin cladding. Other types of steel are or will be irradiated in Phenix. In particular, cold-worked titanium stabilised 316 steel should contribute towards a reduction in the pin clad strains and increase the target burn-up in this reactor. (author)

  15. Strain screen and haplotype association mapping of wheel running in inbred mouse strains.

    Science.gov (United States)

    Lightfoot, J Timothy; Leamy, Larry; Pomp, Daniel; Turner, Michael J; Fodor, Anthony A; Knab, Amy; Bowen, Robert S; Ferguson, David; Moore-Harrison, Trudy; Hamilton, Alicia

    2010-09-01

    Previous genetic association studies of physical activity, in both animal and human models, have been limited in number of subjects and genetically homozygous strains used as well as number of genomic markers available for analysis. Expansion of the available mouse physical activity strain screens and the recently published dense single-nucleotide polymorphism (SNP) map of the mouse genome (approximately 8.3 million SNPs) and associated statistical methods allowed us to construct a more generalizable map of the quantitative trait loci (QTL) associated with physical activity. Specifically, we measured wheel running activity in male and female mice (average age 9 wk) in 41 inbred strains and used activity data from 38 of these strains in a haplotype association mapping analysis to determine QTL associated with activity. As seen previously, there was a large range of activity patterns among the strains, with the highest and lowest strains differing significantly in daily distance run (27.4-fold), duration of activity (23.6-fold), and speed (2.9-fold). On a daily basis, female mice ran further (24%), longer (13%), and faster (11%). Twelve QTL were identified, with three (on Chr. 12, 18, and 19) in both male and female mice, five specific to males, and four specific to females. Eight of the 12 QTL, including the 3 general QTL found for both sexes, fell into intergenic areas. The results of this study further support the findings of a moderate to high heritability of physical activity and add general genomic areas applicable to a large number of mouse strains that can be further mined for candidate genes associated with regulation of physical activity. Additionally, results suggest that potential genetic mechanisms arising from traditional noncoding regions of the genome may be involved in regulation of physical activity.

  16. Temperature and strain registration by fibre-optic strain sensor in the polymer composite materials manufacturing

    Science.gov (United States)

    Matveenko; Kosheleva; Shardakov; Voronkov

    2018-04-01

    The presence of process-induced strains induced by various manufacturing and operational factors is one of the characteristics of polymer composite materials (PCM). Conventional methods of registration and evaluation of process-induced strains can be laborious, time-consuming and demanding in terms of technical applications. The employment of embedded fibre-optic strain sensors (FOSS) offers a real prospect of measuring residual strains. This paper demonstrates the potential for using embedded FOSS for recording technological strains in a PCM plate. The PCM plate is manufactured from prepreg, using the direct compression-moulding method. In this method, the prepared reinforcing package is placed inside a mould, heated, and then exposed to compaction pressure. The examined technology can be used for positioning FOSS between the layers of the composite material. Fibre-optic sensors, interacting with the material of the examined object, make it possible to register the evolution of the strain process during all stages of polymer-composite formation. FOSS data were recorded with interrogator ASTRO X 327. The obtained data were processed using specially developed algorithms.

  17. Sensitivity Enhancement of FBG-Based Strain Sensor.

    Science.gov (United States)

    Li, Ruiya; Chen, Yiyang; Tan, Yuegang; Zhou, Zude; Li, Tianliang; Mao, Jian

    2018-05-17

    A novel fiber Bragg grating (FBG)-based strain sensor with a high-sensitivity is presented in this paper. The proposed FBG-based strain sensor enhances sensitivity by pasting the FBG on a substrate with a lever structure. This typical mechanical configuration mechanically amplifies the strain of the FBG to enhance overall sensitivity. As this mechanical configuration has a high stiffness, the proposed sensor can achieve a high resonant frequency and a wide dynamic working range. The sensing principle is presented, and the corresponding theoretical model is derived and validated. Experimental results demonstrate that the developed FBG-based strain sensor achieves an enhanced strain sensitivity of 6.2 pm/με, which is consistent with the theoretical analysis result. The strain sensitivity of the developed sensor is 5.2 times of the strain sensitivity of a bare fiber Bragg grating strain sensor. The dynamic characteristics of this sensor are investigated through the finite element method (FEM) and experimental tests. The developed sensor exhibits an excellent strain-sensitivity-enhancing property in a wide frequency range. The proposed high-sensitivity FBG-based strain sensor can be used for small-amplitude micro-strain measurement in harsh industrial environments.

  18. Haemophilus ducreyi Cutaneous Ulcer Strains Diverged from Both Class I and Class II Genital Ulcer Strains: Implications for Epidemiological Studies.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    2016-12-01

    Full Text Available Haemophilus ducreyi has emerged as a major cause of cutaneous ulcers (CU in yaws-endemic regions of the tropics in the South Pacific, South East Asia and Africa. H. ducreyi was once thought only to cause the genital ulcer (GU disease chancroid; GU strains belong to 2 distinct classes, class I and class II. Using whole-genome sequencing of 4 CU strains from Samoa, 1 from Vanuatu and 1 from Papua New Guinea, we showed that CU strains diverged from the class I strain 35000HP and that one CU strain expressed β-lactamase. Recently, the Center for Disease Control and Prevention released the genomes of 11 additional CU strains from Vanuatu and Ghana; however, the evolutionary relationship of these CU strains to previously-characterized CU and GU strains is unknown.We performed phylogenetic analysis of 17 CU and 10 GU strains. Class I and class II GU strains formed two distinct clades. The class I strains formed two subclades, one containing 35000HP and HD183 and the other containing the remainder of the class I strains. Twelve of the CU strains formed a subclone under the class I 35000HP subclade, while 2 CU strains formed a subclone under the other class I subclade. Unexpectedly, 3 of the CU strains formed a subclone under the class II clade. Phylogenetic analysis of dsrA-hgbA-ncaA sequences yielded a tree similar to that of whole-genome phylogenetic tree.CU strains diverged from multiple lineages within both class I and class II GU strains. Multilocus sequence typing of dsrA-hgbA-ncaA could be reliably used for epidemiological investigation of CU and GU strains. As class II strains grow relatively poorly and are relatively more susceptible to vancomycin than class I strains, these findings have implications for methods to recover CU strains. Comparison of contemporary CU and GU isolates would help clarify the relationship between these entities.

  19. Haemophilus ducreyi Cutaneous Ulcer Strains Diverged from Both Class I and Class II Genital Ulcer Strains: Implications for Epidemiological Studies.

    Science.gov (United States)

    Gangaiah, Dharanesh; Spinola, Stanley M

    2016-12-01

    Haemophilus ducreyi has emerged as a major cause of cutaneous ulcers (CU) in yaws-endemic regions of the tropics in the South Pacific, South East Asia and Africa. H. ducreyi was once thought only to cause the genital ulcer (GU) disease chancroid; GU strains belong to 2 distinct classes, class I and class II. Using whole-genome sequencing of 4 CU strains from Samoa, 1 from Vanuatu and 1 from Papua New Guinea, we showed that CU strains diverged from the class I strain 35000HP and that one CU strain expressed β-lactamase. Recently, the Center for Disease Control and Prevention released the genomes of 11 additional CU strains from Vanuatu and Ghana; however, the evolutionary relationship of these CU strains to previously-characterized CU and GU strains is unknown. We performed phylogenetic analysis of 17 CU and 10 GU strains. Class I and class II GU strains formed two distinct clades. The class I strains formed two subclades, one containing 35000HP and HD183 and the other containing the remainder of the class I strains. Twelve of the CU strains formed a subclone under the class I 35000HP subclade, while 2 CU strains formed a subclone under the other class I subclade. Unexpectedly, 3 of the CU strains formed a subclone under the class II clade. Phylogenetic analysis of dsrA-hgbA-ncaA sequences yielded a tree similar to that of whole-genome phylogenetic tree. CU strains diverged from multiple lineages within both class I and class II GU strains. Multilocus sequence typing of dsrA-hgbA-ncaA could be reliably used for epidemiological investigation of CU and GU strains. As class II strains grow relatively poorly and are relatively more susceptible to vancomycin than class I strains, these findings have implications for methods to recover CU strains. Comparison of contemporary CU and GU isolates would help clarify the relationship between these entities.

  20. Bioensayo General de Letalidad en Artemia Salina, a Las Fracciones del Extracto Etanólico De Psidium Guajava. L y Psidium Guineense. Sw

    Directory of Open Access Journals (Sweden)

    Lizbeth Sánchez

    2005-10-01

    Full Text Available El estudio se centró en la evaluación y verificación de la letalidad de las fracciones acetato de etilo, obtenida de los extractos etanólicos de los frutos en estado de madurez, verde y pintón, utilizando la cáscara y pulpa de las especies guayaba (Psidium guajava L y Choba (Psidium guineense Sw. La valoración se llevó a cabo mediante el bioensayo en Artemia salina, a través del cual, se evidencia el siguiente proceso: determinar la concentración letal 50 (CL50 utilizando el medio artificial a Ph 7-8, burbujear con el fin de saturar de oxígeno la solución, controlar la eclosión de los huevos a 25 °C despuésde 48 horas, preparar la solución madre y las de trabajo a concentraciones de 1500, 1000, 500,100, 10 g/ml, control positivo estricnina a 80, 70, 60, 50 g/ml, blanco solvente etanol a 80 g/ml. El ensayo biológico se realizó siguiendo las metodologías propuestas por Gualdrón, R (1994; Cyted (1995;Martínez, C (1999 y McLaughlin, J (1997. Comprobada la letalidad de las fracciones acetato del extracto etanólico de Psidium guajava. L y Psidium guineense. Sw mostró CL50 de 181.4 y 221.30g/ml respectivamente, los resultados se evaluaron según Gautret (2000.

  1. Strain quantification in epitaxial thin films

    International Nuclear Information System (INIS)

    Cushley, M

    2008-01-01

    Strain arising in epitaxial thin films can be beneficial in some cases but devastating in others. By altering the lattice parameters, strain may give a thin film properties hitherto unseen in the bulk material. On the other hand, heavily strained systems are prone to develop lattice defects in order to relieve the strain, which can cause device failure or, at least, a decrease in functionality. Using convergent beam electron diffraction (CBED) and high-resolution transmission electron microscopy (HRTEM), it is possible to determine local strains within a material. By comparing the results from CBED and HRTEM experiments, it is possible to gain a complete view of a material, including the strain and any lattice defects present. As well as looking at how the two experimental techniques differ from each other, I will also look at how results from different image analysis algorithms compare. Strain in Si/SiGe samples and BST/SRO/MgO capacitor structures will be discussed.

  2. Brucella abortus strain 2308 Wisconsin genome: importance of the definition of reference strains

    Directory of Open Access Journals (Sweden)

    Marcela Suárez-Esquivel

    2016-09-01

    Full Text Available Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing (WGS analysis of the reference strain Brucella abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version at www.wikipedia.Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised.

  3. Crescimento e acúmulo de N, P e K pelo meloeiro irrigado com água salina Growth and N, P and K accumulation by melon irrigated with saline water

    Directory of Open Access Journals (Sweden)

    José Francismar de Medeiros

    2008-12-01

    Full Text Available O uso de água salina na irrigação é muito comum em cultivos de melão em regiões semi-áridas, o que pode resultar na salinização do solo e redução de rendimento se o manejo da irrigação não for adequado. O presente trabalho teve como objetivo avaliar o crescimento e o acúmulo de N, P e K em plantas de melão (Cucumis melo, L. irrigadas com água salina. Os tratamentos estudados resultaram da combinação de dois fatores: salinidade da água de irrigação (1,1; 2,5 e 4,5 dS m-1 e materiais de melão (híbrido Trusty e cultivar Orange Flesh. O delineamento estatístico adotado foi de blocos inteiramente casualizados com quatro repetições, com tratamentos arranjados em esquema fatorial 3 x 2. A época de coleta de plantas foi analisado como outro fator e os resultados interpretados por análise multivariada. As plantas amostradas foram fracionadas em folhas + ramos e frutos, determinaram-se as produções de matérias secas e os conteúdos de N, P e K nestes materiais. Os acúmulos dos nutrientes nos frutos e de fitomassa seca na planta diminuíram com o incremento da salinidade da água de irrigação. Os frutos exportaram, em média, 57,1%, 67,1% e 70,0% dos totais de N, P, K, absorvidos pela planta e alocados na parte aérea, mostrando, portanto, que foram o principal dreno para estes nutrientes na planta.The use of saline water for irrigation is very common in cultivation of melon in semiarid zones, which can result in the soil salinization if irrigation management is not appropriate. The growth and accumulation of N, P and K by melon (Cucumis melo, L. irrigated with saline water was evaluated. Treatments resulted from the combination of the factors irrigation water salinity levels (1.1; 2.5 and 4.5 dS m-1 and melon materials (hybrid Trusty and cultivar Orange Flesh. Treatments were arranged following a completely randomized block design with four replications, arranged in 3 x 2 factorial. Another factor analyzed was time of

  4. Molecular characterization of the probiotic strain Bacillus cereus var. toyoi NCIMB 40112 and differentiation from food poisoning strains.

    Science.gov (United States)

    Klein, Günter

    2011-07-01

    Bacillus cereus var. toyoi strain NCIMB 40112 (Toyocerin), a probiotic authorized in the European Union as feed additive for swine, bovines, poultry, and rabbits, was characterized by DNA fingerprinting applying pulsed-field gel electrophoresis and multilocus sequence typing and was compared with reference strains (of clinical and environmental origins). The probiotic strain was clearly characterized by pulsed-field gel electrophoresis using the restriction enzymes Apa I and Sma I resulting in unique DNA patterns. The comparison to the clinical reference strain B. cereus DSM 4312 was done with the same restriction enzymes, and again a clear differentiation of the two strains was possible by the resulting DNA patterns. The use of the restriction enzymes Apa I and Sma I is recommended for further studies. Furthermore, multilocus sequence typing analysis revealed a sequence type (ST 111) that was different from all known STs of B. cereus strains from food poisoning incidents. Thus, a strain characterization and differentiation from food poisoning strains for the probiotic strain was possible. Copyright ©, International Association for Food Protection

  5. Microstructure and strain distribution in freestanding Si membrane strained by Si{sub x}N{sub y} deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gao Hongye, E-mail: qgaohongye@msn.com [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Ikeda, Ken-ichi; Hata, Satoshi; Nakashima, Hideharu [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Wang Dong; Nakashima, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)

    2010-09-25

    Research highlights: {yields} Strain is introduced by deposition of amorphous Si{sub x}N{sub y} to improve the carrier mobility for a relatively large-size freestanding semiconductor film, which can be used for the fabrication of relatively large devices such like a bipolar junction transistor. However, standard Raman spectroscopy and X-ray diffraction cannot provide sufficient lateral resolution to the strain in a relatively long (x {mu}m in length) and thin (x nm in thickness) freestanding semiconductor film. {yields} In present research, strain in a bridge-shaped freestanding Si membrane (FSSM) was measured by convergent-beam electron diffraction (CBED) and finite element method (FEM). Compressive strain distribution was shown in three dimensions (3D) in FSSM, where no threading dislocation or stacking fault was found. Relaxation of the strain in FSSM in 3D was discussed based on a comparison of the strain magnitudes in FSSM as measured by CBED and FEM. - Abstract: Strain in a bridge-shaped freestanding Si membrane (FSSM) induced by depositing an amorphous Si{sub x}N{sub y} layer was measured by convergent-beam electron diffraction (CBED). CBED results show that the strain magnitude depends negatively on the FSSM thickness. FEM is a supplement of the result of CBED due to the relaxation of TEM samples during fabricating. The FEM analysis results ascertain the strain property in three dimensions, and show that the strain magnitude depends negatively on the length of FSSM, and the magnitude of the compressive strain in FSSM increases as the position is closer to the upper Si/Si{sub x}N{sub y} interface.

  6. The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Ulett, G.C.; Schembri, M.A.

    2006-01-01

    Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract....... The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory...... to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human...

  7. Acquirement of true stress-strain curve using true fracture strain obtained by tensile test and FE analysis

    International Nuclear Information System (INIS)

    Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil

    2009-01-01

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  8. Acquirement of true stress-strain curve using true fracture strain obtained by tensile test and FE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of)

    2009-07-01

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  9. Acquirement of True Stress-strain Curve Using True Fracture Strain Obtained by Tensile Test and FE Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoung Yoon; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of); Kim, Tae Hyung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    In this work, we predict a true fracture strain using load-displacement curves from tensile test and finite element analysis (FEA), and suggest a method for acquiring true stress-strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.

  10. Atlas of stress-strain curves

    CERN Document Server

    2002-01-01

    The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

  11. Graphene spin diode: Strain-modulated spin rectification

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yunhua; Wang, B., E-mail: stslyl@mail.sysu.edu.cn, E-mail: wangbiao@mail.sysu.edu.cn [Sino-French Institute of Nuclear Engineering and Technology, School of Physics and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275 (China); Liu, Yulan, E-mail: stslyl@mail.sysu.edu.cn, E-mail: wangbiao@mail.sysu.edu.cn [School of Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-08-04

    Strain effects on spin transport in a ferromagnetic/strained/normal graphene junction are explored theoretically. It is shown that the spin-resolved Fermi energy range can be controlled by the armchair direction strain because the strain-induced pseudomagnetic field suppresses the current. The spin rectification effect for the bias reversal occurs because of a combination of ferromagnetic exchange splitting and the broken spatial symmetry of the junction. In addition, the spin rectification performance can be tuned remarkably by manipulation of the strains. In view of this strain-modulated spin rectification effect, we propose that the graphene-based ferromagnetic/strained/normal junction can be used as a tunable spin diode.

  12. Estratigrafía y paleontología del Cenozoico marino del Gran Bajo y Salinas del Gualicho, Argentina, y descripción de 17 especies nuevas Stratigraphy and Paleontology of the marine Cenozoic from the Gran Bajo and Salinas del Gualicho , Argentina and description of 17 new species

    Directory of Open Access Journals (Sweden)

    Valeria A Reichler

    2010-01-01

    Full Text Available La estratigrafía de la Formación Gran Bajo del Gualicho se presenta con mayor detalle, proponiéndose los nuevos Miembros Saladar y Arrióla, precisando la sucesión faunística integrada por 35 géneros y 41 especies, de las cuales 17 son nuevas y se describen en este estudio: Anadara australis sp. nov., Cubitostrea delrioi sp. nov, Amusium rorii sp. nov., Zygochlamys rizzoloi sp. nov,Pododesmus (Monia atlántica sp. nov, Tawera canalei sp. nov.,Dosinia (Dosinia salarensis sp. nov, 'Spirocolpus' adapicis sp. nov, Torcula magna sp. nov,Magnatica hansi sp. nov., Eudo-lium lissiei sp. nov, Sconsia magdai sp. nov., Chicoreus (Chicoreus guadalupei sp. nov, Penion patagonensis sp. nov, Mitra (Fusimitra carlosi sp. nov, Austroimbricaria brugnii sp. nov. y Polystira cingula sp. nov. El reconocimiento de la Asociación de Moluscos NVG (Nodipecten sp.-Venericor abasolensis-Glycymerita camaronesia sitúa al Membro Saladar nov. en el Moceno Temprano alto-Mioceno Medio bajo y lo correlaciona con la sección superior de la Formación Chenque y con los estratos portadores de Venericor de las formaciones Gaiman y Vaca Mahuida. La fauna de este miembro constituye una evidencia más respecto a la diferenciación en franjas climáticas postulada para Patagonia a partir del Oligoceno Tardío-Mioceno Temprano. En el Miembro Arrióla nov., la asociación recuperada indica probablemente la biozona de Aequipecten paranensis y su relación estratigráfica con la Formación Puerto Madryn del Moceno Tardío bajo, extendiendo el área abarcada por la Provincia Valdesiana hasta las Salinas del Gualicho. La fauna del Miembro Saladar presenta mayor afinidad con las que integran las formaciones Monte León y Chenque, mientras que la del Miembro Arrióla es más afín con las de las formaciones Puerto Madryn y Paraná. Las formaciones chilenas Navidad y Guadal presentan respectivamente el 30% y el 10% de los géneros en común con la fauna del Miembro Saladar

  13. Development of Industrial Yeast Platform Strains

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Dato, Laura; Förster, Jochen

    2014-01-01

    Most of the current metabolic engineering projects are carried out using laboratory strains as the starting host. Although such strains are easily manipulated genetically, their robustness does not always meet the requirements set by industrial fermentation conditions. In such conditions, the cells...... screening of the 36 industrial and laboratory yeast strains. In addition, progress in the development of molecular biology methods for generating the new strains will be presented....

  14. Taxonomic and Strain-Specific Identification of the Probiotic Strain Lactobacillus rhamnosus 35 within the Lactobacillus casei Group▿

    Science.gov (United States)

    Coudeyras, Sophie; Marchandin, Hélène; Fajon, Céline; Forestier, Christiane

    2008-01-01

    Lactobacilli are lactic acid bacteria that are widespread in the environment, including the human diet and gastrointestinal tract. Some Lactobacillus strains are regarded as probiotics because they exhibit beneficial health effects on their host. In this study, the long-used probiotic strain Lactobacillus rhamnosus 35 was characterized at a molecular level and compared with seven reference strains from the Lactobacillus casei group. Analysis of rrn operon sequences confirmed that L. rhamnosus 35 indeed belongs to the L. rhamnosus species, and both temporal temperature gradient gel electrophoresis and ribotyping showed that it is closer to the probiotic strain L. rhamnosus ATCC 53103 (also known as L. rhamnosus GG) than to the species type strain. In addition, L. casei ATCC 334 gathered in a coherent cluster with L. paracasei type strains, unlike L. casei ATCC 393, which was closer to L. zeae; this is evidence of the lack of relatedness between the two L. casei strains. Further characterization of the eight strains by pulsed-field gel electrophoresis repetitive DNA element-based PCR identified distinct patterns for each strain, whereas two isolates of L. rhamnosus 35 sampled 40 years apart could not be distinguished. By subtractive hybridization using the L. rhamnosus GG genome as a driver, we were able to isolate five L. rhamnosus 35-specific sequences, including two phage-related ones. The primer pairs designed to amplify these five regions allowed us to develop rapid and highly specific PCR-based identification methods for the probiotic strain L. rhamnosus 35. PMID:18326671

  15. River analysis and floodplain modeling using HEC-GeoRAS/RAS, GIS and ArcGIS: a case study for the Salinas River

    Science.gov (United States)

    Mishra, P. K.; Bernini Campos, H. E.

    2016-12-01

    The lower portion of the Salinas River in Monterey bay, California has a history of flood, lots of study has been made ab out the water quality since the river provides water for the crops around, but is still in need a detailed study about the river behavior and flood analysis. The floods did significant damage, affecting valuable landing farms, residences and businesses in Monterey County. The first step for this study is comprehend and collect the river bathymetry and surroundings and then analyze the discharge and how it is going to change with time. This thesis develops a model about the specific site, recruiting real data from GIS and performing a flow simulation according to flow data provided by USGS, to verify water surface elevation and floodplain. The ArcMap, developed by ESRI, was used along with an extension (HEC-GeoRAS) because it was indeed the most appropriate model to work with the Digital Elevation Model, develop the floodplain and characterizing the land surface accurately in the study site. The HEC-RAS software, developed by US Army Corp of Engineers, was used to compute one-dimension steady flow and two-dimension unsteady flow, providing flow velocity, water surface elevation and profiles, total surface area, head and friction loss and other characteristics, allowing the analysis of the flow. A mean discharge, a mean peak streamflow and a peak discharge were used for the steady flow and a Hydrograph was used for the unsteady flow, both are based on the 1995 flood and discharge history. This study provides important information about water surface elevation and water flow, allowing stakeholders and the government to analyze solutions to avoid damage to the society and landowners.

  16. Brucella abortus Strain 2308 Wisconsin Genome: Importance of the Definition of Reference Strains

    Science.gov (United States)

    Suárez-Esquivel, Marcela; Ruiz-Villalobos, Nazareth; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Roop II, R. Martin; Comerci, Diego J.; Barquero-Calvo, Elías; Chacón-Díaz, Carlos; Caswell, Clayton C.; Baker, Kate S.; Chaves-Olarte, Esteban; Thomson, Nicholas R.; Moreno, Edgardo; Letesson, Jean J.; De Bolle, Xavier; Guzmán-Verri, Caterina

    2016-01-01

    Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference strain B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised. PMID:27746773

  17. Different distribution patterns of ten virulence genes in Legionella reference strains and strains isolated from environmental water and patients.

    Science.gov (United States)

    Zhan, Xiao-Yong; Hu, Chao-Hui; Zhu, Qing-Yi

    2016-04-01

    Virulence genes are distinct regions of DNA which are present in the genome of pathogenic bacteria and absent in nonpathogenic strains of the same or related species. Virulence genes are frequently associated with bacterial pathogenicity in genus Legionella. In the present study, an assay was performed to detect ten virulence genes, including iraA, iraB, lvrA, lvrB, lvhD, cpxR, cpxA, dotA, icmC and icmD in different pathogenicity islands of 47 Legionella reference strains, 235 environmental strains isolated from water, and 4 clinical strains isolated from the lung tissue of pneumonia patients. The distribution frequencies of these genes in reference or/and environmental L. pneumophila strains were much higher than those in reference non-L. pneumophila or/and environmental non-L. pneumophila strains, respectively. L. pneumophila clinical strains also maintained higher frequencies of these genes compared to four other types of Legionella strains. Distribution frequencies of these genes in reference L. pneumophila strains were similar to those in environmental L. pneumophila strains. In contrast, environmental non-L. pneumophila maintained higher frequencies of these genes compared to those found in reference non-L. pneumophila strains. This study illustrates the association of virulence genes with Legionella pathogenicity and reveals the possible virulence evolution of non-L. pneumophia strains isolated from environmental water.

  18. Development of high temperature strain gage, (5)

    International Nuclear Information System (INIS)

    Yuuki, Hiroshi; Kobayashi, Yukio; Kanai, Kenji; Yamaura, Yoshio

    1976-01-01

    Development and improvement of resistance wire type strain gages usable for experimental measurement of thermal strains generated at high temperature in various structures and equipments that consist of a Fast Breeder Reactor have been carried out, and various characteristics of the strain gages have been investigated. Based on the results obtained up to now, development and research of this time mainly aim to improve strain and fatigue characteristics. As the results, characteristics of strain gages with sensing elements of nichrome V are improved, specifically mechanical hysteresis is decreased, strain limit is increased, etc. Also, improvement is recognized in thermal output, and it becomes clear that dummy gages work effectively. However, a filling method of MgO and an inserting method of active-dummy elements are selected as primary objects to improve strain characteristics, and many hours are taken for these objects, so confirmations of characteristics of platinum-tungsten strain gages, strain sensing elements of which are troublesome to produce, have not been completely done, though the performance of the gages has been improved in several points. As to nichrome V strain gages, there is a fair prospect of obtaining ones, specifications of which are quite close to the goal, though problems in manufacturing technics remain for future. As to platinum-tungsten strain gages, it is expected that similar strain gages to nichrome V are obtainable by improvement in manufacturing of sensing elements. (auth.)

  19. Differentiation of five strains of infectious bursal disease virus: Development of a strain-specific multiplex PCR

    DEFF Research Database (Denmark)

    Kusk, M.; Kabell, Susanne; Jørgensen, Poul Henrik

    2005-01-01

    and histopathology. Since these methods are laborious and have low specificity alternatives are needed. In the present study, we report the development of a strain-specific multiplex RT-PCR technique, which can detect and differentiate between field strains of IBDV and vaccine virus strains including a so-called hot...

  20. MM98.57 Quantification of Combined Strain Paths

    DEFF Research Database (Denmark)

    Nielsen, Morten Sturgård; Wanheim, Tarras

    1998-01-01

    this curve into useful scalar relations from experimental data.The strain history for plane strain when assuming volume constancy may be plotted in a shear strain, normal strain diagram, which has the property of showing both the rotation of principal deformation axes during the deformation and the amount...... is to describe the total strain history as a curve in the 6-dimensional shear strain, normal strain space. In order to be able to use these experimental data for calculation, the development of this strain curve must be transformed into a set of scalar relations that may be used for predicting the yield surface...... at a given point in a new strain history. A simple example of this concept is to take the length of the strain curve as describing scalar relation: E.g. to use the equivalent strain as parameter for describing the yield stress. This paper focuses on the strain curve concept and the possibilities to convert...

  1. Job strain and male fertility.

    Science.gov (United States)

    Hjollund, Niels Henrik I; Bonde, Jens Peter E; Henriksen, Tine Brink; Giwercman, Aleksander; Olsen, Jørn

    2004-01-01

    Job strain, defined as high job demands and low job control, has not previously been explored as a possible determinant of male fertility. We collected prospective data on job strain among men, and describe the associations with semen quality and probability of conceiving a clinical pregnancy during a menstrual cycle. Danish couples (N = 399) who were trying to become pregnant for the first time were followed for up to 6 menstrual periods. All men collected semen samples, and a blood sample was drawn from both partners. Job demand and job control were measured by a self-administered questionnaire at entry, and in each cycle the participants recorded changes in job control or job demand during the previous 30 days. In adjusted analyses, no associations were found between any semen characteristic or sexual hormones and any job strain variable. The odds for pregnancy were not associated with job strain. Psychologic job strain encountered in normal jobs in Denmark does not seem to affect male reproductive function.

  2. Improved thermal stability and hole mobilities in a strained-Si/strained-Si1-yGe y/strained-Si heterostructure grown on a relaxed Si1-xGe x buffer

    International Nuclear Information System (INIS)

    Gupta, Saurabh; Lee, Minjoo L.; Isaacson, David M.; Fitzgerald, Eugene A.

    2005-01-01

    A dual channel heterostructure consisting of strained-Si/strained-Si 1-y Ge y on relaxed Si 1-x Ge x (y > x), provides a platform for fabricating metal-oxide-semiconductor field-effect transistors (MOSFETs) with high hole mobilities (μ eff ) which depend directly on Ge concentration and strain in the strained-Si 1-y Ge y layer. Ge out-diffuses from the strained-Si 1-y Ge y layer into relaxed Si 1-x Ge x during high temperature processing, reducing peak Ge concentration and strain in the strained-Si 1-y Ge y layer and degrades hole μ eff in these dual channel heterostructures. A heterostructure consisting of strained-Si/strained-Si 1-y Ge y /strained-Si, referred to as a trilayer heterostructure, grown on relaxed Si 1-x Ge x has much reduced Ge out-flux from the strained-Si 1-y Ge y layer and retains higher μ eff after thermal processing. Improved hole μ eff over similar dual channel heterostructures is also observed in this heterostructure. This could be a result of preventing the hole wavefunction tunneling into the low μ eff relaxed Si 1-x Ge x layer due to the additional valence band offset provided by the underlying strained-Si layer. A diffusion coefficient has been formulated and implemented in a finite difference scheme for predicting the thermal budget of the strained SiGe heterostructures. It shows that the trilayer heterostructures have superior thermal budgets at higher Ge concentrations. Ring-shaped MOSFETs were fabricated on both platforms and subjected to various processing temperatures in order to compare the extent of μ eff reduction with thermal budget. Hole μ eff enhancements are retained to a much higher extent in a trilayer heterostructure after high temperature processing as compared to a dual channel heterostructure. The improved thermal stability and hole μ eff of a trilayer heterostructure makes it an ideal platform for fabricating high μ eff MOSFETs that can be processed over higher temperatures without significant losses in hole

  3. Predicting creep rupture from early strain data

    International Nuclear Information System (INIS)

    Holmstroem, Stefan; Auerkari, Pertti

    2009-01-01

    To extend creep life modelling from classical rupture modelling, a robust and effective parametric strain model has been developed. The model can reproduce with good accuracy all parts of the creep curve, economically utilising the available rupture models. The resulting combined model can also be used to predict rupture from the available strain data, and to further improve the rupture models. The methodology can utilise unfailed specimen data for life assessment at lower stress levels than what is possible from rupture data alone. Master curves for creep strain and rupture have been produced for oxygen-free phosphorus-doped (OFP) copper with a maximum testing time of 51,000 h. Values of time to specific strain at given stress (40-165 MPa) and temperature (125-350 deg. C) were fitted to the models in the strain range of 0.1-38%. With typical inhomogeneous multi-batch creep data, the combined strain and rupture modelling involves the steps of investigation of the data quality, extraction of elastic and creep strain response, rupture modelling, data set balancing and creep strain modelling. Finally, the master curves for strain and rupture are tested and validated for overall fitting efficiency. With the Wilshire equation as the basis for the rupture model, the strain model applies classical parametric principles with an Arrhenius type of thermal activation and a power law type of stress dependence for the strain rate. The strain model also assumes that the processes of primary and secondary creep can be reasonably correlated. The rupture model represents a clear improvement over previous models in the range of the test data. The creep strain information from interrupted and running tests were assessed together with the rupture data investigating the possibility of rupture model improvement towards lower stress levels by inverse utilisation of the combined rupture based strain model. The developed creep strain model together with the improved rupture model is

  4. A Linear Viscoelastic Model Calibration of Sylgard 184.

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin Nicholas; Brown, Judith Alice

    2017-04-01

    We calibrate a linear thermoviscoelastic model for solid Sylgard 184 (90-10 formulation), a lightly cross-linked, highly flexible isotropic elastomer for use both in Sierra / Solid Mechanics via the Universal Polymer Model as well as in Sierra / Structural Dynamics (Salinas) for use as an isotropic viscoelastic material. Material inputs for the calibration in both codes are provided. The frequency domain master curve of oscillatory shear was obtained from a report from Los Alamos National Laboratory (LANL). However, because the form of that data is different from the constitutive models in Sierra, we also present the mapping of the LANL data onto Sandia’s constitutive models. Finally, blind predictions of cyclic tension and compression out to moderate strains of 40 and 20% respectively are compared with Sandia’s legacy cure schedule material. Although the strain rate of the data is unknown, the linear thermoviscoelastic model accurately predicts the experiments out to moderate strains for the slower strain rates, which is consistent with the expectation that quasistatic test procedures were likely followed. This good agreement comes despite the different cure schedules between the Sandia and LANL data.

  5. A wide extent of inter-strain diversity in virulent and vaccine strains of alphaherpesviruses.

    Directory of Open Access Journals (Sweden)

    Moriah L Szpara

    2011-10-01

    Full Text Available Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1 and 2, and varicella zoster virus (VZV. These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV, causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine strain Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine strain. We find many previously unknown coding differences between PRV Bartha and the virulent strains, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-strain variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs, a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between strains. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between strains. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV strain, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit

  6. Marker list: QM83877 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available TGTATCATCG cv. Valmaine x cv. Salinas 88 and Salinas LG_02 ... Tvr1 (dieback, a soilborne disease caused by two viruses from the family Tombusviridae) 3 10.1186/1471-2229-9-135 19930659

  7. Crescimento do feijão caupi submetido a inoculação com rizóbio e irrigação com água salina

    Directory of Open Access Journals (Sweden)

    Jailma Ribeiro de Andrade

    2012-10-01

    Full Text Available A fixação biológica do nitrogênio (FBN é caracterizada pela conversão do nitrogênio gasoso (N2 em nitrogênio amoniacal (NH4, forma disponível às plantas. A cultura do feijão caupi gera em média 1.055.334 empregos, o potencial de suprimento alimentar é de 26.486.755 pessoas e o valor da produção é de R$ 643,09 milhões. Objetivou-se com esse trabalho avaliar parâmetros de crescimento no Feijão caupi irrigado com água salina. O experimento foi conduzido em casa de vegetação da Universidade Federal de Campina Grande (UFCG. Os tratamentos foram constituídos de diferentes níveis de salinidade da água de irrigação (1,5; 3,0; 4,5 e 6,0 dS m-1, sendo cada unidade experimental representada por uma planta/vaso, com capacidade de 1,5 Kg de solo. Os resultados obtidos foram submetidos às análises de variância, pelo teste de Tukey a 1 e 5% de significância. O acréscimo da salinidade afeta o número de folhas, diâmetro do caule e área foliar. Quanto ao desenvolvimento da cultura, todas as variáveis são afetadas após os 30 DAE.

  8. Phytoplankton abundance in relation to the quality of the coastal water – Arabian Gulf, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Mostafa Abdel Mohsen El Gammal

    2017-12-01

    Full Text Available Phytoplankton abundance in relation to some physicochemical characters of the costal water of Arabian Gulf (Saudi Arabia was studied for one year. The sampling program included 15 locations in Dammam, Saihat, Al-Qatif, Al-Awamia and Safwa. Water samples were analyzed monthly for these parameters; temperature, pH, salinity, dissolved oxygen, nitrite, nitrate, ammonia, carbon dioxide, total chloride, reactive orthophosphate and total phosphorus and alkalinity, also phytoplankton communities were identified and Chlorophyll a was estimated. The results showed that, the high phytoplankton density attaining the maximum (190.3 × 104/m3 during May and June, and the minimum (10.4 × 104/m3 during November and December. Forty Five species belonging to 5 phytoplankton groups were recorded. Bacillariophyceae was the first dominant group forming 48% of the total phytoplankton communities (23 species. The dominant species of Bacillariophyceae were Pleurosigma strigosum, Pleurosigma elongatum, Lyrella clavata, Rhizosolenia shrubsolei, Cylindrotheca closterium, Nitzschia panduriform, Nitzschia longissimia, Amphora sp and Stephanopyxis. Dinophyceae was the second dominant group and formed 31% of the total phytoplankton communities (10 species; the dominant species were Ceratium fusus, Heterosigma sp, Ceratium furca, Prorocentrum triestium, Protoperidinium sp, Gyrodinium spirale, Noctiluca scintillans and Scrippsiella trochoidea. Cyanophyceae formed 13% (5 species where Nostoc sp, Oscillatoria and Merismopedia sp were the dominant species. Chlorophyceae had 8% (6 species; Scendesmus sp., Chlorella sp., Chlamydomonas sp., Dunaliella salina and Nannochloropsis sp were the dominant species. The Euglinophyceae was rare only one species (Euglina sp. The relationship was positive between the phytoplankton, chlorophyll a and carbon dioxide while negative amongst dissolved oxygen and total nitrogen. This research indicated that the relation between water quality

  9. [Characteristics of Lactobacillus strains contained in pharmaceuticals].

    Science.gov (United States)

    Banach, W; Bucholc, B; Wójcik, B

    2001-01-01

    The aim of the study was to characterize lactic acid bacteria (LAB) which are components of drugs administered orally in cases of intestinal disturbances, or antibiotic--related diarrhea. Biochemical properties, growth behavior, bile tolerance, and survival at low pH of six LAB strains (four strains L. rhamnosus and two L. acidophilus) were studied. The survival at low pH was determined in MRS broth (Difco) acidified to pH 1; 2; 3; and 4. Bile tolerance was tested on MRS broth with 0.3% oxgall (Difco). Between tested strains differences in ability to grow at low pH and survival in bile were observed. Only 0.01% inoculum of all examined strains survived at pH 1. Differences between strains in survival at low pH (pH 2 and pH 3) and tolerance of bile were observed. However, after 2 h incubation at pH 4, 100% of strains stayed alive. Examined strains demonstrated good 3% bile tolerance. All strains met the criteria for probiotic strains: ability to survive at pH 3 and in the presence of bile.

  10. Strain histograms are equal to strain ratios in predicting malignancy in breast tumours

    DEFF Research Database (Denmark)

    Carlsen, Jonathan Frederik; Ewertsen, Caroline; Sletting, Susanne

    2017-01-01

    Objectives: To assess whether strain histograms are equal to strain ratios in predicting breast tumour malignancy and to see if either could be used to upgrade Breast Imaging Reporting and Data System (BI-RADS) 3 tumours for immediate biopsy. Methods: Ninety-nine breast tumours were examined using...

  11. A New Acetylenic Compound and Other Bioactive Metabolites from a Shark Gill-derived Penicillium Strain

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2017-01-01

    Full Text Available Nine chiral compounds (1−9 were isolated from the static fermentation culture of a shark gill-derived fungus Penicillium polonicum AP2T1. These compounds include a new acetylenic aromatic ether (1 , (--WA , four alkaloids ( a urantiomide C ( 2 , fructigenine A (3, cyclopenin (4 and cyclopenol (5 and four oxygenated compounds ((R-penipratynolene (6, (3S,4S-3,4-dihydro-3,4,8-trihydroxyl-naphthalenone (7, verrucosidin (8 and norverrucosidin (9. Their structures were elucidated by MS, NMR , optical rotation and circular dichroism (CD . In antimicrobial tests , compounds 1–4, 6 and 8–9 showed weak antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and/or Escherichia coli.Compounds 3, 8 and 9 also exhibited moderate toxicity against Artemia salina larva , and showed cytotoxicity against human colon cancer cell line HCT116.

  12. Strains and Stressors: An Analysis of Touchscreen Learning in Genetically Diverse Mouse Strains

    Science.gov (United States)

    Graybeal, Carolyn; Bachu, Munisa; Mozhui, Khyobeni; Saksida, Lisa M.; Bussey, Timothy J.; Sagalyn, Erica; Williams, Robert W.; Holmes, Andrew

    2014-01-01

    Touchscreen-based systems are growing in popularity as a tractable, translational approach for studying learning and cognition in rodents. However, while mouse strains are well known to differ in learning across various settings, performance variation between strains in touchscreen learning has not been well described. The selection of appropriate genetic strains and backgrounds is critical to the design of touchscreen-based studies and provides a basis for elucidating genetic factors moderating behavior. Here we provide a quantitative foundation for visual discrimination and reversal learning using touchscreen assays across a total of 35 genotypes. We found significant differences in operant performance and learning, including faster reversal learning in DBA/2J compared to C57BL/6J mice. We then assessed DBA/2J and C57BL/6J for differential sensitivity to an environmental insult by testing for alterations in reversal learning following exposure to repeated swim stress. Stress facilitated reversal learning (selectively during the late stage of reversal) in C57BL/6J, but did not affect learning in DBA/2J. To dissect genetic factors underlying these differences, we phenotyped a family of 27 BXD strains generated by crossing C57BL/6J and DBA/2J. There was marked variation in discrimination, reversal and extinction learning across the BXD strains, suggesting this task may be useful for identifying underlying genetic differences. Moreover, different measures of touchscreen learning were only modestly correlated in the BXD strains, indicating that these processes are comparatively independent at both genetic and phenotypic levels. Finally, we examined the behavioral structure of learning via principal component analysis of the current data, plus an archival dataset, totaling 765 mice. This revealed 5 independent factors suggestive of “reversal learning,” “motivation-related late reversal learning,” “discrimination learning,” “speed to respond,” and

  13. Resposta de plantas de melancieira irrigadas com água salina ao tratamento pré-germinativo da semente com H2O2

    Directory of Open Access Journals (Sweden)

    Auderlan de Macena Pereira

    2013-10-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE O manejo da água é um dos fatores mais importantes para uma efetiva absorção de nutrientes, uma vez que esta pode apresentar-se com elevadas concentrações de sais, o que pode afetar o processo de absorção, bem como causar estresse oxidativo nos vegetais, devido as espécies reativas de oxigênios (EROs, principalmente H2O2. As plantas evoluíram um complexo sistema antioxidante para conter os efeitos deletérios das EROs, é possível que a pré-exposição das plantas ao H2O2 possibilite uma adaptação das mesmas. Estudando-se uma alternativa para amenizar os efeitos deletérios das EROs,objetivou-se, neste trabalho, avaliar a resposta de plantas de melancieira, irrigadas com água salina, ao tratamento pré-germinativo da semente com H2O2. O experimento foi conduzido no Centro de Ciências e Tecnologia Agroalimentar-CCTA, da UFCG-Pombal – PB. O delineamento experimental utilizado foi de blocos casualizados em parcelas subdivididas 2x5, com 4 repetições, com a parcela constando de dois níveis de salinidade da água de irrigação (S1 = água de abastecimento local, 0,32 dSm-1; e S2 =  água salina, 2,0 dS m-1 e a subparcela de sementes de melancieira tratadas com solução de H2O2 em cinco concentrações (0, 5, 10, 15 e 20 µmol L-1. As aplicações foram feitas via água de irrigação, junto à solução nutritiva a 100%, utilizada como fonte de nutrientes. O experimento foi conduzido até o início da floração (45 DAS, quando foram avaliadas as seguintes características de crescimento: Massa Fresca da Parte Aérea, Massa Seca da Parte Aérea, Número de Folhas por Planta e Comprimento da Haste Principal. Avalio-use também as características fisiológicas: Taxa de Fotossíntese, Transpiração, Condutância Estomática e Concentração de CO2 intracelular. Os dados foram submetidos à análise de variância ao nível de 5 % de probabilidade. Os níveis de salinidades da

  14. Relating high-temperature flow stress of AISI 316 stainless steel to strain and strain rate

    International Nuclear Information System (INIS)

    Matteazzi, S.; Paitti, G.; Boerman, D.

    1982-01-01

    The authors have performed an experimental determination of tensile stress-strain curves for different strain rates (4.67 x 10 - 5 , 4.67 x 10 - 2 s - 1 ) and for a variety of temperature conditions (773-1073 K) of AISI 316H stainless steel (annealed conditions) and also a computer analysis of the experimental curves using a fitting program which takes into consideration different constitutive relations describing the plastic flow behaviour of the metals. The results show that the materials tested are clearly affected by strain rate only at the highest temperature investigated (1073 K) and that the plastic strain is the more significant variable. Of the constitutive equations considered, Voce's relation gives the best fit for the true stress-time-strain curves. However, the Ludwik and Ludwigson equations also provide a description of the experimental data, whereas Hollomon's equation does not suitably characterize AISI 316H stainless steel and can be applied with some accuracy only at 1073 K. (author)

  15. Evaluating location specific strain rates, temperatures, and accumulated strains in friction welds through microstructure modeling

    Directory of Open Access Journals (Sweden)

    Javed Akram

    2018-04-01

    Full Text Available A microstructural simulation method is adopted to predict the location specific strain rates, temperatures, grain evolution, and accumulated strains in the Inconel 718 friction welds. Cellular automata based 2D microstructure model was developed for Inconel 718 alloy using theoretical aspects of dynamic recrystallization. Flow curves were simulated and compared with experimental results using hot deformation parameter obtained from literature work. Using validated model, simulations were performed for friction welds of Inconel 718 alloy generated at three rotational speed i.e., 1200, 1500, and 1500 RPM. Results showed the increase in strain rates with increasing rotational speed. These simulated strain rates were found to match with the analytical results. Temperature difference of 150 K was noticed from center to edge of the weld. At all the rotational speeds, the temperature was identical implying steady state temperature (0.89Tm attainment. Keywords: Microstructure modeling, Dynamic recrystallization, Friction welding, Inconel 718, EBSD, Hot deformation, Strain map

  16. Intraspecies diversity of Lactobacillus sakei response to oxidative stress and variability of strain performance in mixed strains challenges.

    Science.gov (United States)

    Guilbaud, Morgan; Zagorec, Monique; Chaillou, Stéphane; Champomier-Vergès, Marie-Christine

    2012-04-01

    Lactobacillus sakei is a meat-borne lactic acid bacterium species exhibiting a wide genomic diversity. We have investigated the diversity of response to various oxidative compounds, between L. sakei strains, among a collection representing the genomic diversity. We observed various responses to the different compounds as well as a diversity of response depending on the aeration conditions used for cell growth. A principal component analysis revealed two main phenotypic groups, partially correlating with previously described genomic clusters. We designed strains mixes composed of three different strains, in order to examine the behavior of each strain, when cultured alone or in the presence of other strains. The strains composing the mixtures were chosen as diverse as possible, i.e. exhibiting diverse responses to oxidative stress and belonging to different genomic clusters. Growth and survival rates of each strain were monitored under various aeration conditions, with or without heme supplementation. The results obtained suggest that some strains may act as "helper" or "burden" strains depending on the oxidative conditions encountered during incubation. This study confirms that resistance to oxidative stress is extremely variable within the L. sakei species and that this property should be considered when investigating starter performance in the complex meat bacterial ecosystems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Genetic analysis of Saccharomyces cerevisiae strains isolated from palm wine in eastern Nigeria. Comparison with other African strains.

    Science.gov (United States)

    Ezeronye, O U; Legras, J-L

    2009-05-01

    To study the yeast diversity of Nigerian palm wines by comparison with other African strains. Twenty-three Saccharomyces cerevisiae strains were obtained from palm wine samples collected at four locations in eastern Nigeria, and characterized using different molecular techniques: internal transcribed spacer restriction fragment length polymorphism and sequence analysis, pulsed field gel electrophoresis, inter delta typing and microsatellite multilocus analysis. These techniques revealed that palm wine yeasts represent a group of closely related strains that includes other West African isolates (CBS400, NCYC110, DVPG6044). Population analysis revealed an excess of homozygote strains and an allelic richness similar to wine suggestive of local domestication. Several other African yeast strains were not connected to this group. Ghana sorghum beer strains and other African strains (DBVPG1853 and MUCL28071) displayed strikingly high relatedness with European bread, beer or wine strains, and the genome of strain MUCL30909 contained African and wine-type alleles, indicating its hybrid origin. Nigerian palm wine yeast represents a local specific yeast flora, whereas a European origin or hybrid was suspected for several other Africa isolates. This study presents the first genetic characterization of an autochthonous African palm wine yeast population and confirms the idea that human intervention has favoured yeast migration.

  18. Internal residual strain mapping in carburized chrome molybdenum steel after quenching by neutron strain scanning

    International Nuclear Information System (INIS)

    Sakaida, Yoshihisa; Serizawa, Takanobu; Manzanka, Michiya

    2011-01-01

    A hollow circular cylinder specimen with an annular U-notch of chrome molybdenum steel with 0.20 mass% C (SCM420) was carburized in carrier gas and quenched in oil bath. In order to determine the case depth, the specimen was cut off and carbon content and Vickers hardness gradients were measured experimentally near the carburized surface. The residual strain mapping in the interior of carburized cylinder was conducted nondestructively by neutron strain scanning. In this study, the neutron diffraction from Fe-211 plane was used for strain scanning. The neutron wavelength was tuned to 0.1654nm so that diffraction angle became about 90deg. Radial, hoop and axial residual strains were measured by scanning diffracting volume along the axial direction of cylinder specimen. Each residual strain was calculated from lattice spacing change. Unstressed lattice spacing was determined experimentally using reference coupon specimens that were cut from the interior of same carburized cylinder. As a result, the diffraction peak width at half height, FWHM, near the carburized surface was about 3.7 times wider than that of coupon specimens. On the other hand, the most peak widths in the interior equaled to that of coupon specimens. Peak width broadened slightly as the diffracting volume approached the carburized case layer. From the center to the quarter of cylinder specimen, the hoop and axial strains were tensile, and the radial one was compressive in the interior. From the quarter to the edge of the cylinder specimen, the hoop tensile strain increased, radial and axial strains changed to tensile and compressive, respectively. Therefore, the interior of the cylinder specimen was found to be deformed elastically to balance the existence of compressive residual stresses in the carburized case layer. (author)

  19. Strain gradient effects in surface roughening

    DEFF Research Database (Denmark)

    Borg, Ulrik; Fleck, N.A.

    2007-01-01

    evidence for strain gradient effects. Numerical analyses of a bicrystal undergoing in-plane tensile deformation are also studied using a strain gradient crystal plasticity theory and also by using a strain gradient plasticity theory for an isotropic solid. Both theories include an internal material length...

  20. Nanocomposite Strain Gauges Having Small TCRs

    Science.gov (United States)

    Gregory, Otto; Chen, Ximing

    2009-01-01

    Ceramic strain gauges in which the strain-sensitive electrically conductive strips made from nanocomposites of noble metal and indium tin oxide (ITO) are being developed for use in gas turbine engines and other power-generation systems in which gas temperatures can exceed 1,500 F (about 816 C). In general, strain gauges exhibit spurious thermally induced components of response denoted apparent strain. When temperature varies, a strain-gauge material that has a nonzero temperature coefficient of resistance (TCR) exhibits an undesired change in electrical resistance that can be mistaken for the change in resistance caused by a change in strain. It would be desirable to formulate straingauge materials having TCRs as small as possible so as to minimize apparent strain. Most metals exhibit positive TCRs, while most semiconductors, including ITO, exhibit negative TCRs. The present development is based on the idea of using the negative TCR of ITO to counter the positive TCRs of noble metals and of obtaining the benefit of the ability of both ITO and noble metals to endure high temperatures. The noble metal used in this development thus far has been platinum. Combinatorial libraries of many ceramic strain gauges containing nanocomposites of various proportions of ITO and platinum were fabricated by reactive co-sputtering from ITO and platinum targets onto alumina- and zirconia-based substrates mounted at various positions between the targets.

  1. Contrasting the Genetic Patterns of Microbial Communities in Soda Lakes with and without Cyanobacterial Bloom.

    Science.gov (United States)

    Andreote, Ana P D; Dini-Andreote, Francisco; Rigonato, Janaina; Machineski, Gabriela Silva; Souza, Bruno C E; Barbiero, Laurent; Rezende-Filho, Ary T; Fiore, Marli F

    2018-01-01

    Soda lakes have high levels of sodium carbonates and are characterized by salinity and elevated pH. These ecosystems are found across Africa, Europe, Asia, Australia, North, Central, and South America. Particularly in Brazil, the Pantanal region has a series of hundreds of shallow soda lakes (ca. 600) potentially colonized by a diverse haloalkaliphilic microbial community. Biological information of these systems is still elusive, in particular data on the description of the main taxa involved in the biogeochemical cycling of life-important elements. Here, we used metagenomic sequencing to contrast the composition and functional patterns of the microbial communities of two distinct soda lakes from the sub-region Nhecolândia, state of Mato Grosso do Sul, Brazil. These two lakes differ by permanent cyanobacterial blooms (Salina Verde, green-water lake) and by no record of cyanobacterial blooms (Salina Preta, black-water lake). The dominant bacterial species in the Salina Verde bloom was Anabaenopsis elenkinii . This cyanobacterium altered local abiotic parameters such as pH, turbidity, and dissolved oxygen and consequently the overall structure of the microbial community. In Salina Preta, the microbial community had a more structured taxonomic profile. Therefore, the distribution of metabolic functions in Salina Preta community encompassed a large number of taxa, whereas, in Salina Verde, the functional potential was restrained across a specific set of taxa. Distinct signatures in the abundance of genes associated with the cycling of carbon, nitrogen, and sulfur were found. Interestingly, genes linked to arsenic resistance metabolism were present at higher abundance in Salina Verde and they were associated with the cyanobacterial bloom. Collectively, this study advances fundamental knowledge on the composition and genetic potential of microbial communities inhabiting tropical soda lakes.

  2. Contrasting the Genetic Patterns of Microbial Communities in Soda Lakes with and without Cyanobacterial Bloom

    Science.gov (United States)

    Andreote, Ana P. D.; Dini-Andreote, Francisco; Rigonato, Janaina; Machineski, Gabriela Silva; Souza, Bruno C. E.; Barbiero, Laurent; Rezende-Filho, Ary T.; Fiore, Marli F.

    2018-01-01

    Soda lakes have high levels of sodium carbonates and are characterized by salinity and elevated pH. These ecosystems are found across Africa, Europe, Asia, Australia, North, Central, and South America. Particularly in Brazil, the Pantanal region has a series of hundreds of shallow soda lakes (ca. 600) potentially colonized by a diverse haloalkaliphilic microbial community. Biological information of these systems is still elusive, in particular data on the description of the main taxa involved in the biogeochemical cycling of life-important elements. Here, we used metagenomic sequencing to contrast the composition and functional patterns of the microbial communities of two distinct soda lakes from the sub-region Nhecolândia, state of Mato Grosso do Sul, Brazil. These two lakes differ by permanent cyanobacterial blooms (Salina Verde, green-water lake) and by no record of cyanobacterial blooms (Salina Preta, black-water lake). The dominant bacterial species in the Salina Verde bloom was Anabaenopsis elenkinii. This cyanobacterium altered local abiotic parameters such as pH, turbidity, and dissolved oxygen and consequently the overall structure of the microbial community. In Salina Preta, the microbial community had a more structured taxonomic profile. Therefore, the distribution of metabolic functions in Salina Preta community encompassed a large number of taxa, whereas, in Salina Verde, the functional potential was restrained across a specific set of taxa. Distinct signatures in the abundance of genes associated with the cycling of carbon, nitrogen, and sulfur were found. Interestingly, genes linked to arsenic resistance metabolism were present at higher abundance in Salina Verde and they were associated with the cyanobacterial bloom. Collectively, this study advances fundamental knowledge on the composition and genetic potential of microbial communities inhabiting tropical soda lakes. PMID:29520256

  3. Contrasting the Genetic Patterns of Microbial Communities in Soda Lakes with and without Cyanobacterial Bloom

    Directory of Open Access Journals (Sweden)

    Ana P. D. Andreote

    2018-02-01

    Full Text Available Soda lakes have high levels of sodium carbonates and are characterized by salinity and elevated pH. These ecosystems are found across Africa, Europe, Asia, Australia, North, Central, and South America. Particularly in Brazil, the Pantanal region has a series of hundreds of shallow soda lakes (ca. 600 potentially colonized by a diverse haloalkaliphilic microbial community. Biological information of these systems is still elusive, in particular data on the description of the main taxa involved in the biogeochemical cycling of life-important elements. Here, we used metagenomic sequencing to contrast the composition and functional patterns of the microbial communities of two distinct soda lakes from the sub-region Nhecolândia, state of Mato Grosso do Sul, Brazil. These two lakes differ by permanent cyanobacterial blooms (Salina Verde, green-water lake and by no record of cyanobacterial blooms (Salina Preta, black-water lake. The dominant bacterial species in the Salina Verde bloom was Anabaenopsis elenkinii. This cyanobacterium altered local abiotic parameters such as pH, turbidity, and dissolved oxygen and consequently the overall structure of the microbial community. In Salina Preta, the microbial community had a more structured taxonomic profile. Therefore, the distribution of metabolic functions in Salina Preta community encompassed a large number of taxa, whereas, in Salina Verde, the functional potential was restrained across a specific set of taxa. Distinct signatures in the abundance of genes associated with the cycling of carbon, nitrogen, and sulfur were found. Interestingly, genes linked to arsenic resistance metabolism were present at higher abundance in Salina Verde and they were associated with the cyanobacterial bloom. Collectively, this study advances fundamental knowledge on the composition and genetic potential of microbial communities inhabiting tropical soda lakes.

  4. Strain-dependent diffusion behavior of H within tungsten

    International Nuclear Information System (INIS)

    Ding, Wenyi; He, Haiyan; Liu, Changsong; Ding, Rui; Chen, Junling; Pan, Bicai

    2014-01-01

    The diffusion behaviors of H in tungsten, a promising material serving as the first wall facing the plasma in nuclear reactors, under either biaxial strain or isotropic strain are theoretically studied. We find that under the isotropic strain, an individual H atom may diffuse along all pathways, and under the biaxial strain, it preferably migrates along the direction perpendicular to the loaded strain. Moreover, in the case of either the isotropic or the biaxial strain, the loaded compressive strain weakens the diffusion of H, while the loaded tensile strain enhances the diffusion of H in bulk W.

  5. Strain-dependent diffusion behavior of H within tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wenyi; He, Haiyan [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu, Changsong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Ding, Rui; Chen, Junling [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Pan, Bicai, E-mail: bcpan@ustc.edu.cn [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-06-15

    The diffusion behaviors of H in tungsten, a promising material serving as the first wall facing the plasma in nuclear reactors, under either biaxial strain or isotropic strain are theoretically studied. We find that under the isotropic strain, an individual H atom may diffuse along all pathways, and under the biaxial strain, it preferably migrates along the direction perpendicular to the loaded strain. Moreover, in the case of either the isotropic or the biaxial strain, the loaded compressive strain weakens the diffusion of H, while the loaded tensile strain enhances the diffusion of H in bulk W.

  6. Use of colony-based bacterial strain typing for tracking the fate of Lactobacillus strains during human consumption

    Directory of Open Access Journals (Sweden)

    Drevinek Pavel

    2009-12-01

    Full Text Available Abstract Background The Lactic Acid Bacteria (LAB are important components of the healthy gut flora and have been used extensively as probiotics. Understanding the cultivable diversity of LAB before and after probiotic administration, and being able to track the fate of administered probiotic isolates during feeding are important parameters to consider in the design of clinical trials to assess probiotic efficacy. Several methods may be used to identify bacteria at the strain level, however, PCR-based methods such as Random Amplified Polymorphic DNA (RAPD are particularly suited to rapid analysis. We examined the cultivable diversity of LAB in the human gut before and after feeding with two Lactobacillus strains, and also tracked the fate of these two administered strains using a RAPD technique. Results A RAPD typing scheme was developed to genetically type LAB isolates from a wide range of species, and optimised for direct application to bacterial colony growth. A high-throughput strategy for fingerprinting the cultivable diversity of human faeces was developed and used to determine: (i the initial cultivable LAB strain diversity in the human gut, and (ii the fate of two Lactobacillus strains (Lactobacillus salivarius NCIMB 30211 and Lactobacillus acidophilus NCIMB 30156 contained within a capsule that was administered in a small-scale human feeding study. The L. salivarius strain was not cultivated from the faeces of any of the 12 volunteers prior to capsule administration, but appeared post-feeding in four. Strains matching the L. acidophilus NCIMB 30156 feeding strain were found in the faeces of three volunteers prior to consumption; after taking the Lactobacillus capsule, 10 of the 12 volunteers were culture positive for this strain. The appearance of both Lactobacillus strains during capsule consumption was statistically significant (p Conclusion We have shown that genetic strain typing of the cultivable human gut microbiota can be

  7. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.

  8. Engineering piezoresistivity using biaxially strained silicon

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Richter, Jacob; Brandbyge, Mads

    2008-01-01

    of the piezocoefficient on temperature and dopant density is altered qualitatively for strained silicon. In particular, we find that a vanishing temperature coefficient may result for silicon with grown-in biaxial tensile strain. These results suggest that strained silicon may be used to engineer the iezoresistivity...

  9. Strain path dependency in metal plasticity

    NARCIS (Netherlands)

    Viatkina, E.M.; Brekelmans, W.A.M.; Geers, M.G.D.

    2003-01-01

    A change in strain path has a significant effect on the mechanical response of metals. Strain path change effects physically originate from a complex microstructure evolution. This paper deals with the contribution of cell structure evolution to the strain path change effect. The material with cells

  10. Sensibility of different wheat varieties (strains) to Ar+ implantation

    International Nuclear Information System (INIS)

    Cui Huanhu; Jing Hua; Ma Aiping; Kang Xiuli; Yang Liping; Huang Mingjing; Ma Buzhou; Shanxi Academy of Agricultural Sciences, Taiyuan

    2005-01-01

    The sensibility of different wheat varieties (strains) to Ar + implantation was studied. The results showed that the survival rate of 21 wheat varieties (strains) at the dose of 6 x 10 16 Ar + /cm 2 could be divided into five groups: surplus sensitive varieties (strains), sensitive varieties (strains), transitional varieties (strains), obtuse varieties (strains) and surplus obtuse varieties (strains). The sensibility of wheat varieties (strains) to Ar + injection is high-moisture-fertility wheat varieties (strains) > medium-moisture-fertility wheat varieties (strains) > dry land wheat varieties (strains). The study has provided theoretical basis in induced mutation medial lethal dose of different wheat varieties (strains) to Ar + implantation. (authors)

  11. drug resistant strains of Salmonella enterica

    African Journals Online (AJOL)

    Conclusions: The aqueous extract of Thonningia sanguinea can provide an alternative therapy for the treatment of salmonellosis, mainly for typhoid fever caused by MDR strains of S. Typhi.The extract also inhibits S.Hadar a MDR emerging strain in Ivory Coast. Keywords: Thonningia sanguinea; Salmonella, MDR strains, ...

  12. Viral lysis of Phaeocystis pouchetii: implications for algal population dynamics and heterotrophic C, N and P cycling

    DEFF Research Database (Denmark)

    Haaber, Jakob Brandt Borup; Middelboe, Mathias

    2009-01-01

    in the microbial food web was associated with significant N and P mineralization, supporting the current view that viral lysates can be an important source of inorganic nutrients in marine systems. In the presence of R. salina, the generated NH(4)(+) supported 11% of the observed R. salina growth. Regrowth...... of virus-resistant P. pouchetii following cell lysis was observed in long-term incubations (150 days), and possibly influenced by nutrient availability and competition from R. salina. The observed impact of viral activity on autotrophic and heterotrophic processes provides direct experimental evidence...

  13. Validation of perceptual strain index to evaluate the thermal strain in experimental hot conditions

    Directory of Open Access Journals (Sweden)

    Habibollah Dehghan

    2015-01-01

    Conclusions: The research findings showed when there is no access to other forms of methods to evaluate the heat stress, it can be used the PeSI in evaluating the strain because of its favorable correlation with the thermal strain.

  14. Mechanical properties of biaxially strained poly(L-lactide) tubes: Strain rate and temperature dependence

    DEFF Research Database (Denmark)

    Løvdal, Alexandra Liv Vest; Andreasen, Jens Wenzel; Mikkelsen, Lars Pilgaard

    2017-01-01

    Poly(l-lactide) (PLLA) is a bioabsorbable polymer with high stiffness and strength compared to the other commercially available bioabsorbable polymers. The properties of PLLA can be improved by straining, causing deformation-mediated molecular orientation. PLLA tubes were biaxially strained above...

  15. StrainSeeker: fast identification of bacterial strains from raw sequencing reads using user-provided guide trees.

    Science.gov (United States)

    Roosaare, Märt; Vaher, Mihkel; Kaplinski, Lauris; Möls, Märt; Andreson, Reidar; Lepamets, Maarja; Kõressaar, Triinu; Naaber, Paul; Kõljalg, Siiri; Remm, Maido

    2017-01-01

    Fast, accurate and high-throughput identification of bacterial isolates is in great demand. The present work was conducted to investigate the possibility of identifying isolates from unassembled next-generation sequencing reads using custom-made guide trees. A tool named StrainSeeker was developed that constructs a list of specific k -mers for each node of any given Newick-format tree and enables the identification of bacterial isolates in 1-2 min. It uses a novel algorithm, which analyses the observed and expected fractions of node-specific k -mers to test the presence of each node in the sample. This allows StrainSeeker to determine where the isolate branches off the guide tree and assign it to a clade whereas other tools assign each read to a reference genome. Using a dataset of 100 Escherichia coli isolates, we demonstrate that StrainSeeker can predict the clades of E. coli with 92% accuracy and correct tree branch assignment with 98% accuracy. Twenty-five thousand Illumina HiSeq reads are sufficient for identification of the strain. StrainSeeker is a software program that identifies bacterial isolates by assigning them to nodes or leaves of a custom-made guide tree. StrainSeeker's web interface and pre-computed guide trees are available at http://bioinfo.ut.ee/strainseeker. Source code is stored at GitHub: https://github.com/bioinfo-ut/StrainSeeker.

  16. Modulation of virulence and antibiotic susceptibility of enteropathogenic Escherichia coli strains by Enterococcus faecium probiotic strain culture fractions.

    Science.gov (United States)

    Ditu, Lia-Mara; Chifiriuc, Mariana Carmen; Bezirtzoglou, Eugenia; Voltsi, Chrysa; Bleotu, Coralia; Pelinescu, Diana; Mihaescu, Grigore; Lazar, Veronica

    2011-12-01

    The increasing rate of antimicrobial resistance drastically reduced the efficiency of conventional antibiotics and led to the reconsideration of the interspecies interactions in influencing bacterial virulence and response to therapy. The aim of the study was the investigation of the influence of the soluble and cellular fractions of Enterococcus (E.) faecium CMGB16 probiotic culture on the virulence and antibiotic resistance markers expression in clinical enteropathogenic Escherichia (E.) coli strains. The 7 clinical enteropathogenic E. coli strains, one standard E. coli ATCC 25,922 and one Bacillus (B.) cereus strains were cultivated in nutrient broth, aerobically at 37 °C, for 24 h. The E. faecium CMGB16 probiotic strain was cultivated in anaerobic conditions, at 37 °C in MRS (Man Rogosa Sharpe) broth, and co-cultivated with two pathogenic strains (B. cereus and E. coli O28) culture fractions (supernatant, washed sediment and heat-inactivated culture) for 6 h, at 37 °C. After co-cultivation, the soluble and cellular fractions of the probiotic strain cultivated in the presence of two pathogenic strains were separated by centrifugation (6000 rpm, 10 min), heat-inactivated (15 min, 100 °C) and co-cultivated with the clinical enteropathogenic E. coli strains in McConkey broth, for 24 h, at 37 °C, in order to investigate the influence of the probiotic fractions on the adherence capacity and antibiotic susceptibility. All tested probiotic combinations influenced the adherence pattern of E. coli tested strains. The enteropathogenic E. coli strains susceptibility to aminoglycosides, beta-lactams and quinolones was increased by all probiotic combinations and decreased for amoxicillin-clavulanic acid. This study demonstrates that the plurifactorial anti-infective action of probiotics is also due to the modulation of virulence factors and antibiotic susceptibility expression in E. coli pathogenic strains. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Strain distributions and their influence on electronic structures of WSe2-MoS2 laterally strained heterojunctions

    Science.gov (United States)

    Zhang, Chendong; Li, Ming-Yang; Tersoff, Jerry; Han, Yimo; Su, Yushan; Li, Lain-Jong; Muller, David A.; Shih, Chih-Kang

    2018-02-01

    Monolayer transition metal dichalcogenide heterojunctions, including vertical and lateral p-n junctions, have attracted considerable attention due to their potential applications in electronics and optoelectronics. Lattice-misfit strain in atomically abrupt lateral heterojunctions, such as WSe2-MoS2, offers a new band-engineering strategy for tailoring their electronic properties. However, this approach requires an understanding of the strain distribution and its effect on band alignment. Here, we study a WSe2-MoS2 lateral heterojunction using scanning tunnelling microscopy and image its moiré pattern to map the full two-dimensional strain tensor with high spatial resolution. Using scanning tunnelling spectroscopy, we measure both the strain and the band alignment of the WSe2-MoS2 lateral heterojunction. We find that the misfit strain induces type II to type I band alignment transformation. Scanning transmission electron microscopy reveals the dislocations at the interface that partially relieve the strain. Finally, we observe a distinctive electronic structure at the interface due to hetero-bonding.

  18. Material Properties Test to Determine Ultimate Strain and True Stress-True Strain Curves for High Yield Steels

    Energy Technology Data Exchange (ETDEWEB)

    K.R. Arpin; T.F. Trimble

    2003-04-01

    This testing was undertaken to develop material true stress-true strain curves for elastic-plastic material behavior for use in performing transient analysis. Based on the conclusions of this test, the true stress-true strain curves derived herein are valid for use in elastic-plastic finite element analysis for structures fabricated from these materials. In addition, for the materials tested herein, the ultimate strain values are greater than those values cited as the limits for the elastic-plastic strain acceptance criteria for transient analysis.

  19. Chemical Profile of Monascus ruber Strains

    Directory of Open Access Journals (Sweden)

    Ahamed M. Moharram

    2012-01-01

    Full Text Available Chemical profile of Monascus ruber strains has been studied using gas chromatography-mass spectrometry (GC/MS analysis. The colour intensity of the red pigment and secondary metabolic products of two M. ruber strains (AUMC 4066 and AUMC 5705 cultivated on ten different media were also studied. Metabolic products can be classified into four categories: anticholesterol, anticancer, food colouring, and essential fatty acids necessary for human health. Using GC/MS, the following 88 metabolic products were detected: butyric acid and its derivatives (25 products, other fatty acids and their derivatives (19 products, pyran and its derivatives (22 products and other metabolites (22 products. Among these, 32 metabolites were specific for AUMC 4066 strain and 34 for AUMC 5705 strain, whereas 22 metabolites were produced by both strains on different tested substrates. Production of some metabolites depended on the substrate used. High number of metabolites was recorded in the red pigment extract obtained by both strains grown on malt broth and malt agar. Also, 42 aroma compounds were recorded (4 alcohols, 2 benzaldehydes, 27 esters, 3 lactones, 1 phenol, 1 terpenoid, 3 thiol compounds and acetate-3-mercapto butyric acid. Thin layer chromatography and GC/MS analyses revealed no mycotoxin citrinin in any media used for the growth of the two M. ruber strains.

  20. Effects of C and Si on strain aging of strain-based API X60 pipeline steels

    Science.gov (United States)

    Sung, Hyo Kyung; Lee, Dong Ho; Lee, Sunghak; Lee, Byeong-Joo; Hong, Seung-Pyo; Kim, Young-Woon; Yoo, Jang Yong; Hwang, Byoungchul; Shin, Sang Yong

    2017-05-01

    Four types of strain-based API X60 pipeline steels were fabricated by varying the C and Si contents, and the effects of C and Si on strain aging were investigated. The 0.05 wt% C steels consisted mainly of polygonal ferrite (PF), whereas the 0.08 wt% C steels consisted of acicular ferrite (AF). The volume fraction of AF increased with increasing C content because C is an austenite stabilizer element. The volume fractions of bainitic ferrite (BF) of the 0.15 wt% Si steels were higher than those of the 0.25 wt% Si steels, whereas the volume fractions of the secondary phases were lower. From the tensile properties before and after the aging process of the strainbased API X60 pipeline steels, the yield strength increased and the uniform and total elongation decreased, which is the strain aging effect. The strain aging effect in the strain-based API X60 pipeline steels was minimized when the volume fraction of AF was increased and secondary phases were distributed uniformly. On the other hand, an excessively high C content formed fine precipitates, and the strain aging effect occurred because of the interactions among dislocations and fine precipitates.

  1. Evaluation of strain-rate sensitivity of ion-irradiated austenitic steel using strain-rate jump nanoindentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Kasada, Ryuta, E-mail: r-kasada@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University Gokasho, Uji 611-0011, Kyoto (Japan); Konishi, Satoshi [Institute of Advanced Energy, Kyoto University Gokasho, Uji 611-0011, Kyoto (Japan); Hamaguchi, Dai; Ando, Masami; Tanigawa, Hiroyasu [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan)

    2016-11-01

    Highlights: • We examined strain-rate jump nanoindentation on ion-irradiated stainless steel. • We observed irradiation hardening of the ion-irradiated stainless steel. • We found that strain-rate sensitivity parameter was slightly decreased after the ion-irradiation. - Abstract: The present study investigated strain-rate sensitivity (SRS) of a single crystal Fe–15Cr–20Ni austenitic steel before and after 10.5 MeV Fe{sup 3+} ion-irradiation up to 10 dpa at 300 °C using a strain-rate jump (SRJ) nanoindentation test. It was found that the SRJ nanoindentation test is suitable for evaluating the SRS at strain-rates from 0.001 to 0.2 s{sup −1}. Indentation size effect was observed for depth dependence of nanoindentation hardness but not the SRS. The ion-irradiation increased the hardness at the shallow depth region but decreased the SRS slightly.

  2. 5-Fluorouracil-resistant strain of Methanobacterium thermoautortrophicum

    International Nuclear Information System (INIS)

    Nagle, D.P. Jr.; Teal, R.; Eisenbraun, A.

    1987-01-01

    Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14 C-labeled uracil or FU by the two strains was compared, the wilt type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype

  3. 5-Fluorouracil-resistant strain of Methanobacterium thermoautotrophicum.

    Science.gov (United States)

    Nagle, D P; Teal, R; Eisenbraun, A

    1987-09-01

    Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14C-labeled uracil or FU by the two strains was compared, the wild type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype.

  4. Complete Genomic Sequences of H3N8 Equine Influenza Virus Strains Used as Vaccine Strains in Japan.

    Science.gov (United States)

    Nemoto, Manabu; Yamanaka, Takashi; Bannai, Hiroshi; Tsujimura, Koji; Kokado, Hiroshi

    2018-03-22

    We sequenced the eight segments of influenza A virus strains A/equine/Ibaraki/1/2007 and A/equine/Yokohama/aq13/2010, which are strains of the Florida sublineage clades 1 and 2 of the H3N8 subtype equine influenza virus. These strains have been used as vaccine strains in Japan since 2016 in accordance with World Organization for Animal Health (OIE) recommendations. Copyright © 2018 Nemoto et al.

  5. Strain accumulation in quasicrystalline solids

    International Nuclear Information System (INIS)

    Nori, F.; Ronchetti, M.; Elser, V.

    1988-01-01

    We study the relaxation of 2D quasicrystalline elastic networks when their constituent bonds are perturbed homogeneously. Whereas ideal, quasiperiodic networks are stable against such perturbations, we find significant accumulations of strain in a class of disordered networks generated by a growth process. The grown networks are characterized by root mean square phason fluctuations which grow linearly with system size. The strain accumulation we observe in these networks also grows linearly with system size. Finally, we find a dependence of strain accumulation on cooling rate

  6. Towards development of nanofibrous large strain flexible strain sensors with programmable shape memory properties

    Science.gov (United States)

    Khalili, N.; Asif, H.; Naguib, H. E.

    2018-05-01

    Electrospun polymeric fibers can be used as strain sensors due to their large surface to weight/volume ratio, high porosity and pore interconnectivity. Large strain flexible strain sensors are used in numerous applications including rehabilitation, health monitoring, and sports performance monitoring where large strain detection should be accommodated by the sensor. This has boosted the demand for a stretchable, flexible and highly sensitive sensor able to detect a wide range of mechanically induced deformations. Herein, a physically cross-linked polylactic acid (PLA) and thermoplastic polyurethane (TPU) blend is made into nanofiber networks via electrospinning. The PLA/TPU weight ratio is optimized to obtain a maximum attainable strain of 100% while maintaining its mechanical integrity. The TPU/PLA fibers also allowed for their thermally activated recovery due to shape memory properties of the substrate. This novel feature enhances the sensor’s performance as it is no longer limited by its plastic deformation. Using spray coating method, a homogeneous layer of single-walled carbon nanotube is deposited onto the as-spun fiber mat to induce electrical conductivity to the surface of the fibers. It is shown that stretching and bending the sensor result in a highly sensitive and linear response with a maximum gauge factor of 33.

  7. A closer look at prion strains

    Science.gov (United States)

    Solforosi, Laura; Milani, Michela; Mancini, Nicasio; Clementi, Massimo; Burioni, Roberto

    2013-01-01

    Prions are infectious proteins that are responsible for transmissible spongiform encephalopathies (TSEs) and consist primarily of scrapie prion protein (PrPSc), a pathogenic isoform of the host-encoded cellular prion protein (PrPC). The absence of nucleic acids as essential components of the infectious prions is the most striking feature associated to these diseases. Additionally, different prion strains have been isolated from animal diseases despite the lack of DNA or RNA molecules. Mounting evidence suggests that prion-strain-specific features segregate with different PrPSc conformational and aggregation states. Strains are of practical relevance in prion diseases as they can drastically differ in many aspects, such as incubation period, PrPSc biochemical profile (e.g., electrophoretic mobility and glycoform ratio) and distribution of brain lesions. Importantly, such different features are maintained after inoculation of a prion strain into genetically identical hosts and are relatively stable across serial passages. This review focuses on the characterization of prion strains and on the wide range of important implications that the study of prion strains involves. PMID:23357828

  8. Local strains in waste tank deflagration analysis

    International Nuclear Information System (INIS)

    Bryan, B.J.; Flanders, H.E. Jr.

    1993-01-01

    In recent years extensive effort has been expended to qualify buried nuclear waste storage tanks under accident conditions. One of these conditions is deflagration of the combustible gases which may build up over time. While much work has been done to calculate the general strain state, less effort has been made to address the local strains at structural discontinuities. An analytical method is presented for calculating these local strains and combining them with the general strain state. A closed form solution of the local strains is compared to a finite element solution

  9. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjøllund, Niels Henrik Ingvar; Jensen, T.K.; Bonde, J.P.

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  10. Strain characterization of FinFETs using Raman spectroscopy

    International Nuclear Information System (INIS)

    Kaleli, B.; Hemert, T. van; Hueting, R.J.E.; Wolters, R.A.M.

    2013-01-01

    Metal induced strain in the channel region of silicon (Si) fin-field effect transistor (FinFET) devices has been characterized using Raman spectroscopy. The strain originates from the difference in thermal expansion coefficient of Si and titanium-nitride. The Raman map of the device region is used to determine strain in the channel after preparing the device with the focused ion beam milling. Using the Raman peak shift relative to that of relaxed Si, compressive strain values up to – 0.88% have been obtained for a 5 nm wide silicon fin. The strain is found to increase with reducing fin width though it scales less than previously reported results from holographic interferometry. In addition, finite-element method (FEM) simulations have been utilized to analyze the amount of strain generated after thermal processing. It is shown that obtained FEM simulated strain values are in good agreement with the calculated strain values obtained from Raman spectroscopy. - Highlights: ► Strain is characterized in nanoscale devices with Raman spectroscopy. ► There is a fin width dependence of the originated strain. ► Strain levels obtained from this technique is in correlation with device simulations

  11. Strain bidimensional na cardiopatia de Takotsubo Two-dimensional strain in Takotsubo cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Carlos Bellini G. Gomes

    2010-08-01

    Full Text Available Este relato apresenta o seguimento tardio de um caso de cardiomiopatia de Takotsubo com boa evolução clínica e melhora da função sistólica global ventricular esquerda. Contudo, observou-se persistência de significativa disfunção sistólica regional longitudinal que foi avaliada por meio de nova técnica ecocardiográfica (speckle tracking, com as medidas do strain (S e strain rate (SR correspondentes. Ressaltamos a importância desse novo método para o acompanhamento dessa cardiopatia, pois permite identificar os pacientes que persistem com disfunção sistólica e que possivelmente serão beneficiados com a manutenção da terapêutica clínica.This report presents the late follow-up of a case of Takotsubo cardiomyopathy with good clinical outcome and improved left ventricular global systolic function. However, there was persistence of significant regional longitudinal systolic dysfunction evaluated using a new echocardiographic technique (speckle tracking, with corresponding measures of strain (S and strain rate (SR. We emphasize the importance of this new method to monitoring this cardiomyopathy, since it identifies patients with persistent systolic dysfunction who will possibly benefit from maintenance of clinical therapy

  12. Resonant tunneling measurements of size-induced strain relaxation

    Science.gov (United States)

    Akyuz, Can Deniz

    Lattice mismatch strain available in such semiconductor heterostructures as Si/SiGe or GaAs/AlGaAs can be employed to alter the electronic and optoelectronic properties of semiconductor structures and devices. When deep submicron structures are fabricated from strained material, strained layers relax by sidewall expansion giving rise to size- and geometry-dependent strain gradients throughout the structure. This thesis describes a novel experimental technique to probe the size-induced strain relaxation by studying the tunneling current characteristics of strained p-type Si/SiGe resonant tunneling diodes. Our current-voltage measurements on submicron strained p-Si/SiGe double- and triple-barrier resonant tunneling structures as a function of device diameter, D, provide experimental access to both the average strain relaxation (which leads to relative shifts in the tunneling current peak positions) and strain gradients (which give rise to a fine structure in the current peaks due to inhomogeneous strain-induced lateral quantization). We find that strain relaxation is significant, with a large fraction of the strain energy relaxed on average in D ≤ 0.25 m m devices. Further, the in-plane potentials that arise from inhomogeneous strain gradients are large. In the D ˜ 0.2 m m devices, the corresponding lateral potentials are approximately parabolic exceeding ˜ 25 meV near the perimeter. These potentials create discrete hole states in double-barrier structures (single well), and coupled hole states in triple-barrier structures (two wells). Our results are in excellent agreement with finite-element strain calculations in which the strained layers are permitted to relax to a state of minimum energy by sidewall expansion. Size-induced strain relaxation will undoubtedly become a serious technological issue once strained devices are scaled down to the deep submicron regime. Interestingly, our calculations predict and our measurements are consistent with the appearance of

  13. Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-12-01

    Full Text Available The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry, since vehicle crushing often happens at intermediate strain rates. Back stress hardening has been found to play an important role for this HSSS due to load transfer and strain partitioning between two phases, and a higher strain rate could cause even higher strain partitioning in the softer austenite grains, delaying the deformation instability. Deformation twins are observed in the austenite grains at all strain rates to facilitate the uniform tensile deformation. The B2 phase (FeAl intermetallic compound is less deformable at higher strain rates, resulting in easier brittle fracture in B2 particles, smaller dimple size and a higher density of phase interfaces in final fracture surfaces. Thus, more energy need be consumed during the final fracture for the experiments conducted at higher strain rates, resulting in better tensile toughness.

  14. Stress and strain measurements in solids

    International Nuclear Information System (INIS)

    Askegaard, V.

    1978-01-01

    A design basis is given for stress- and strain cells to be used in a solid either externally loaded or with a stressfree strain field (for example shrinkage). A stress- and a strain cell has been designed for use in granular materials. Calibration tests show either good or reasonably good correspondance with calculated values. (orig.) [de

  15. Strain specific variation of outer membrane proteins of wild Yersinia pestis strains subjected to different growth temperatures

    Directory of Open Access Journals (Sweden)

    Frederico Guilherme Coutinho Abath

    1990-03-01

    Full Text Available Three Yersinia pestis strains isolated from humans and one laboratory strain (EV76 were grown in rich media at 28§C and 37§C and their outer membrane protein composition compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-Page. Several proteins with molecular weights ranging from 34 kDa to 7 kDa were observed to change in relative abundance in samples grown at different temperatures. At least seven Y. pestis outer membrane proteins showed a temperature-dependent and strain-specific behaviour. Some differences between the outer membrane proteins of full-pathogenic wild isolates and the EV76 strain could aldso be detected and the relevance of this finding on the use of laboratory strains as a reference to the study of Y. pestis biological properties is discuted.

  16. Properties of strain gages at cryogenic temperature

    International Nuclear Information System (INIS)

    Shibata, Nobuo; Fujiyoshi, Toshimitsu.

    1978-01-01

    At the time of developing superconduction generators, the stress measurement for rotor parts is required to grasp the safety and performance of the rotor at cryogenic temperature, which is cooled with liquid helium. In case of carrying out the stress measurement with strain gages, the problems are as follows. The strain gages and lead wires are exposed to cryogenic temperature from 4 to 10 K and strong magnetic field of about 3T, and subjected to high centrifugal acceleration of about 500G. In order to establish the techniques of the stress measurement under such conditions, the adhesives and damp-proof coatings for strain gages and strain gages themselves in Japan and foreign countries were examined on the properties at cryogenic temperature. As for the properties of strain gages, mainly the apparent strain owing to temperature change was investigated, and the change of the gage factors was studies only at liquid nitrogen temperature. The stress measurement with strain gages at low temperature had been studied in detail down to liquid nitrogen temperature concerning LNG tanks. The experimental apparatus, the samples, the testing methods and the test results of cooling tests on adhesives and damp-proof coatings, and the temperature characteristics of strain gages are reported. The usable adhesives and coatings were found, and correction by accurate temperature measurement is required for apparent strain. (Kako, I.)

  17. Resolution of axial shear strain elastography

    International Nuclear Information System (INIS)

    Thitaikumar, Arun; Righetti, Raffaella; Krouskop, Thomas A; Ophir, Jonathan

    2006-01-01

    The technique of mapping the local axial component of the shear strain due to quasi-static axial compression is defined as axial shear strain elastography. In this paper, the spatial resolution of axial shear strain elastography is investigated through simulations, using an elastically stiff cylindrical lesion embedded in a homogeneously softer background. Resolution was defined as the smallest size of the inclusion for which the strain value at the inclusion/background interface was greater than the average of the axial shear strain values at the interface and inside the inclusion. The resolution was measured from the axial shear strain profile oriented at 45 0 to the axis of beam propagation, due to the absence of axial shear strain along the normal directions. The effects of the ultrasound system parameters such as bandwidth, beamwidth and transducer element pitch along with signal processing parameters such as correlation window length (W) and axial shift (ΔW) on the estimated resolution were investigated. The results show that the resolution (at 45 0 orientation) is determined by the bandwidth and the beamwidth. However, the upper bound on the resolution is limited by the larger of the beamwidth and the window length, which is scaled inversely to the bandwidth. The results also show that the resolution is proportional to the pitch and not significantly affected by the axial window shift

  18. Influence of dynamic strain ageing on tensile strain energy of type 316L(N) austenitic stainless steel

    International Nuclear Information System (INIS)

    Isaac Samuel, B.; Choudhary, B.K.; Bhanu Sankara Rao, K.

    2010-01-01

    Tensile tests were conducted on type 316 L(N) stainless steel over a wide temperature range of 300-1123 K employing strain rates ranging from 3.16 X 10 -5 to 3.16 X 10 -3/s . The variation of strain energy in terms of modulus of resilience and modulus of toughness over the wide range of temperatures and strain rates were examined. The variation in modulus of resilience with temperature and strain rate did not show the signatures of dynamic strain ageing (DSA). However, the modulus of toughness exhibited a plateau at the intermediate temperatures of 523-1023 K. Further, the distribution of energy absorbed till necking and energy absorbed from necking till fracture were found to characterise the deformation and damage processes, respectively, and exhibited anomalous variations in the temperature range 523-823 K and 823-1023 K, respectively. In addition to the observed manifestations of DSA such as serrated load-elongation curve, peaks/plateaus in flow stress, ultimate tensile strength and work hardening rate, negative strain rate sensitivity and ductility minima, the observed anomalous variations in modulus of toughness at intermediate temperatures (523-1023 K) can be regarded as yet another key manifestation of DSA. At temperatures above 1023 K, a sharp decrease in the modulus of toughness and also in the strain energies up to necking and from necking to fracture observed, with increasing temperature and decreasing strain rate, reveal the onset of dynamic recovery leading to early cross slip and climb processes. (author)

  19. Ratchetting strain prediction

    International Nuclear Information System (INIS)

    Noban, Mohammad; Jahed, Hamid

    2007-01-01

    A time-efficient method for predicting ratchetting strain is proposed. The ratchetting strain at any cycle is determined by finding the ratchetting rate at only a few cycles. This determination is done by first defining the trajectory of the origin of stress in the deviatoric stress space and then incorporating this moving origin into a cyclic plasticity model. It is shown that at the beginning of the loading, the starting point of this trajectory coincides with the initial stress origin and approaches the mean stress, displaying a power-law relationship with the number of loading cycles. The method of obtaining this trajectory from a standard uniaxial asymmetric cyclic loading is presented. Ratchetting rates are calculated with the help of this trajectory and through the use of a constitutive cyclic plasticity model which incorporates deviatoric stresses and back stresses that are measured with respect to this moving frame. The proposed model is used to predict the ratchetting strain of two types of steels under single- and multi-step loadings. Results obtained agree well with the available experimental measurements

  20. Strain engineering on transmission carriers of monolayer phosphorene.

    Science.gov (United States)

    Zhang, Wei; Li, Feng; Hu, Junsong; Zhang, Ping; Yin, Jiuren; Tang, Xianqiong; Jiang, Yong; Wu, Bozhao; Ding, Yanhuai

    2017-11-22

    The effects of uniaxial strain on the structure, band gap and transmission carriers of monolayer phosphorene were investigated by first-principles calculations. The strain induced semiconductor-metal as well as direct-indirect transitions were studied in monolayer phosphorene. The position of CBM which belonged to indirect gap shifts along the direction of the applied strain. We have concluded the change rules of the carrier effective mass when plane strains are applied. In band structure, the sudden decrease of band gap or the new formation of CBM (VBM) causes the unexpected change in carrier effective mass. The effects of zigzag and armchair strain on the effective electron mass in phosphorene are different. The strain along zigzag direction has effects on the electrons effective mass along both zigzag and armchair direction. By contrast, armchair-direction strain seems to affect only on the free electron mass along zigzag direction. For the holes, the effective masses along zigzag direction are largely affected by plane strains while the effective mass along armchair direction exhibits independence in strain processing. The carrier density of monolayer phosphorene at 300 K is calculated about [Formula: see text] cm -2 , which is greatly influenced by the temperature and strain. Strain engineering is an efficient method to improve the carrier density in phosphorene.

  1. Influência da irrigação com água salina na cultura do girassol Influence of irrigation with saline water on sunflower

    Directory of Open Access Journals (Sweden)

    Francisco Alexandre de Morais

    2011-06-01

    Full Text Available O presente experimento foi realizado com o objetivo de avaliar a influência da irrigação com água salina no crescimento e na produção de girassol (híbrido H251, além de monitorar a evolução de alguns atributos químicos do solo ao longo do ciclo da cultura. O delineamento experimental foi em blocos casualizados com seis tratamentos e cinco repetições. Os tratamentos consistiram de seis diferentes estratégias de irrigação, sendo cinco delas com utilização de água salina. As avaliações de crescimento (altura de planta, diâmetro de caule e número de folhas foram realizadas aos 20; 40; 60; 80; 100 dias após semeadura (DAS. Aos 100 DAS foi realizada a colheita, ocasião em que se mediu o diâmetro de capítulo, sendo determinados posteriormente o peso de 1000 aquênios e a produtividade de aquênios. As coletas de solo foram realizadas concomitantemente às avaliações de crescimento, nas camadas 0-0,10; 0,10-0,30; 0,30-0,50 m. Os atributos químicos do solo avaliados foram Na+, CE e pH, além das relações Na+/Ca2+ e Na+/Mg2+. A cultura do girassol mostrou-se tolerante à salinidade da água de irrigação, indicando que ela pode ser irrigada com água de CE de até 3,53 dS m-1 durante todo o ciclo. Entretanto, quando se utilizar água de média ou alta CE, é necessária a adoção de práticas de controle da salinização/sodificação do solo. A tolerância do girassol à salinidade não dependeu da fase de desenvolvimento. Em geral, os atributos químicos do solo aumentaram e estabilizaram a partir da metade do ciclo.This experiment was made to evaluate the influence of the irrigation with saline water on growth and production of sunflower (híbrido H251, besides monitoring the evolution of some chemical attributes of the soil along its cycle. The experimental design used was the randomized blocks with six treatments and five replications. The treatments consisted of six different irrigation strategies, five of them with

  2. Genome characterization of Turkey Rotavirus G strains from the United States identifies potential recombination events with human Rotavirus B strains.

    Science.gov (United States)

    Chen, Fangzhou; Knutson, Todd P; Porter, Robert E; Ciarlet, Max; Mor, Sunil Kumar; Marthaler, Douglas G

    2017-12-01

    Rotavirus G (RVG) strains have been detected in a variety of avian species, but RVG genomes have been published from only a single pigeon and two chicken strains. Two turkey RVG strains were identified and characterized, one in a hatchery with no reported health issues and the other in a hatchery with high embryo/poult mortality. The two turkey RVG strains shared only an 85.3 % nucleotide sequence identity in the VP7 gene while the other genes possessed high nucleotide identity among them (96.3-99.9 %). Low nucleotide percentage identities (31.6-87.3 %) occurred among the pigeon and chicken RVG strains. Interestingly, potential recombination events were detected between our RVG strains and a human RVB strain, in the VP6 and NSP3 segments. The epidemiology of RVG in avian flocks and the pathogenicity of the two different RVG strains should be further investigated to understand the ecology and impact of RVG in commercial poultry flocks.

  3. Analysis of strain distribution and critical current of superconductors based on a strain-critical current measurement system

    International Nuclear Information System (INIS)

    Liu Fang; Wu Yu; Long Feng

    2010-01-01

    Based on Pacman device which is widely used to investigate the axial strain dependence of the critical current in superconductors, the finite element analysis method is employed to carry out the force analysis of the spring and the superconducting strand, thereby the axial and lateral strain distributions of the superconducting strand are obtained. According to the two extreme assumptions(low inter-filament resistance and high inter-filament resistance), the effects of the strain homogeneity at the cross section of the superconductor on the critical current is analyzed combined with the Nb 3 Sn deviatoric strain-critical current scaling law. (authors)

  4. Recent advances in echocardiography: strain and strain rate imaging [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Oana Mirea

    2016-04-01

    Full Text Available Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications.

  5. Yeast strains and methods of use thereof

    OpenAIRE

    Goddard, Matthew Robert; Gardner, Richard Clague; Anfang, Nicole

    2013-01-01

    The present invention relates to yeast strains and, in particular, to yeast stains for use in fermentation processes. The invention also relates to methods of fermentation using the yeast strains of the invention either alone or in combination with other yeast strains. The invention thither relates to methods for the selection of yeast strains suitable for fermentation cultures by screening for various metabolic products and the use of specific nutrient sources.

  6. Influence of strain on dislocation core in silicon

    Science.gov (United States)

    Pizzagalli, L.; Godet, J.; Brochard, S.

    2018-05-01

    First principles, density functional-based tight binding and semi-empirical interatomic potentials calculations are performed to analyse the influence of large strains on the structure and stability of a 60? dislocation in silicon. Such strains typically arise during the mechanical testing of nanostructures like nanopillars or nanoparticles. We focus on bi-axial strains in the plane normal to the dislocation line. Our calculations surprisingly reveal that the dislocation core structure largely depends on the applied strain, for strain levels of about 5%. In the particular case of bi-axial compression, the transformation of the dislocation to a locally disordered configuration occurs for similar strain magnitudes. The formation of an opening, however, requires larger strains, of about 7.5%. Furthermore, our results suggest that electronic structure methods should be favoured to model dislocation cores in case of large strains whenever possible.

  7. Taxonomy of oxalotrophic Methylobacterium strains

    Science.gov (United States)

    Sahin, Nurettin; Kato, Yuko; Yilmaz, Ferah

    2008-10-01

    Most of the oxalotrophic bacteria are facultative methylotrophs and play important ecological roles in soil fertility and cycling of elements. This study gives a detailed picture of the taxonomy and diversity of these bacteria and provides new information about the taxonomical variability within the genus Methylobacterium. Twelve mesophilic, pink-pigmented, and facultatively methylotrophic oxalate-oxidizing strains were included in this work that had been previously isolated from the soil and some plant tissues by the potassium oxalate enrichment method. The isolates were characterized using biochemical tests, cellular lipid profiles, spectral characteristics of carotenoid pigments, G+C content of the DNA, and 16S rDNA sequencing. The taxonomic similarities among the strains were analyzed using the simple matching ( S SM) and Jaccard ( S J) coefficients, and the UPGMA clustering algorithm. The phylogenetic position of the strains was inferred by the neighbor-joining method on the basis of the 16S rDNA sequences. All isolates were Gram-negative, facultatively methylotrophic, oxidase and catalase positive, and required no growth factors. Based on the results of numerical taxonomy, the strains formed four closely related clusters sharing ≥85% similarity. Analysis of the 16S rDNA sequences demonstrated that oxalotrophic, pink-pigmented, and facultatively methylotrophic strains could be identified as members of the genus Methylobacterium. Except for M. variabile and M. aquaticum, all of the Methylobacterium type strains tested had the ability of oxalate utilization. Our results indicate that the capability of oxalate utilization seems to be an uncommon trait and could be used as a valuable taxonomic criterion for differentiation of Methylobacterium species.

  8. Stress strain flow curves for Cu-OFP

    International Nuclear Information System (INIS)

    Sandstroem, Rolf; Hallgren, Josefin

    2009-04-01

    Stress strain curves of oxygen free copper alloyed with phosphorus Cu-OFP have been determined in compression and tension. The compression tests were performed at room temperature for strain rates between 10 -5 and 10 -3 1/s. The tests in tension covered the temperature range 20 to 175 deg C for strain rates between 10 -7 and 5x10 -3 1/s. The results in compression and tension were close for similar strain rates. A model for stress strain curves has been formulated using basic dislocation mechanisms. The model has been set up in such a way that fitting of parameters to the curves is avoided. By using a fundamental creep model as a basis a direct relation to creep data has been established. The maximum engineering flow stress in tension is related to the creep stress giving the same strain rate. The model reproduces the measured flow curves as function of temperature and strain rate in the investigated interval. The model is suitable to use in finite-element computations of structures in Cu-OFP

  9. New directions in Mexican environmental policy

    Science.gov (United States)

    Mumme, Stephen P.; Sanchez, Roberto A.

    1992-07-01

    Since taking office 1 December 1988, Mexico's incumbent president, Carlos Salinas de Gortari, has introduced important innovations in environmental policy that distinguish his administration from those of his predecessors. Greater administrative continuity, improved regulatory capacity achieved through statutory change, focused priorities centering on pollution abatement in Mexico City, and an aggressive search for external financing for pollution control are hallmarks of Salinas' approach. The success of these environmental reforms depends heavily on economic recovery, however, and environmental policy still suffers from underfunding, bureaucratic fragmentation, and heavy reliance on voluntarist enforcement mechanisms. Recently, U.S. congressional debate on a proposed free trade agreement with Mexico has been a factor in spurring the Salinas government to take new antipollution and conservation measures. Mexico's growing environmental movement is also an important force behind the government's new responsiveness in environmental matters. The Salinas administration recognizes the issue's political salience and has sought to defuse environmental criticism using a large arsenal of resources at its disposal. Salinas' environmental policy strategy may thus be characterized as both proactive and reactive in nature. While the reforms are evidence that Mexico is beginning to take environmental matters more seriously, economic recovery and sustained environmental activism remain vital to further progress.

  10. The many shades of prion strain adaptation.

    Science.gov (United States)

    Baskakov, Ilia V

    2014-01-01

    In several recent studies transmissible prion disease was induced in animals by inoculation with recombinant prion protein amyloid fibrils produced in vitro. Serial transmission of amyloid fibrils gave rise to a new class of prion strains of synthetic origin. Gradual transformation of disease phenotypes and PrP(Sc) properties was observed during serial transmission of synthetic prions, a process that resembled the phenomenon of prion strain adaptation. The current article discusses the remarkable parallels between phenomena of prion strain adaptation that accompanies cross-species transmission and the evolution of synthetic prions occurring within the same host. Two alternative mechanisms underlying prion strain adaptation and synthetic strain evolution are discussed. The current article highlights the complexity of the prion transmission barrier and strain adaptation and proposes that the phenomenon of prion adaptation is more common than previously thought.

  11. On lower order strain gradient plasticity theories

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Hutchinson, J. W.

    2003-01-01

    By way of numerical examples, this paper explores the nature of solutions to a class of strain gradient plasticity theories that employ conventional stresses, equilibrium equations and boundary conditions. Strain gradients come into play in these modified conventional theories only to alter...... the tangent moduli governing increments of stress and strain. It is shown that the modification is far from benign from a mathematical standpoint, changing the qualitative character of solutions and leading to a new type of localization that is at odds with what is expected from a strain gradient theory....... The findings raise questions about the physical acceptability of this class of strain gradient theories....

  12. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  13. Disposal of Radioactive Wastes in Natural Salt; Elimination des Dechets Radioactifs dans le Sel Naturel; 0423 0414 ; Evacuacion de Desechos Radiactivos en Formaciones Salinas Naturales

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F. L.; Boegly, W. J.; Bradshaw, R. L.; Empson, F. M.; Hemphill, L.; Struxness, E. G.; Tamura, T. [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1960-07-01

    sont actuellement en cours. (author) [Spanish] Las razones por las que se propone utilizar las cavidades en las formaciones salinas como lugar de evacuacion de desechos radiactivos son: 1. La gran antigueedad de los yacimientos de sal; 2. La impermeabilidad de la sal al agua; 3. La amplia distribucion geografica de los yacimientos salinos; 4. Las enormes cantidades de sal disponibles ; 5. La resistencia estructural de la sal; 6. La elevada conductividad termica de la sal comparada con la de otras formaciones geologicas; 7. La posibilidad de recuperar valiosos productos de fision de los desechos evacuados en formaciones salinas; 8. La relativa facilidad con que se puedan formar oquedades por excavacion del yacimiento y la facilidad aun mayor de formar cavidades a bajo coste por disolucion de la sal; 9. La escasez de sismos en las zonas donde existen grandes yacimientos de sal. Los desechos radiactivos liquidos pueden almacenarse en las cavidades de los yacimientos salinos naturales si las propiedades estructurales de la sal no resultan desfavorablemente afectadas por la interaccion quimica y los efectos de la presion, temperatura y radiacion. Los estudios analiticos demuestran que luego de dejarlos enfriar durante dos anos es posible almacenar los desechos resultantes del tratamiento de uranio irradiado a 10,000 MW dia per tonelada y formados a razon de 800 galones/tonelada en una esfera de 10 pies de diametro sin que la temperatura exceda de 200 Degree-Sign F. Los ensayos de laboratorio demuestran que las propiedades estructurales y la conductividad termica de la sal gema no resultan apreciablemente alteradas por grandes dosis de radiacion, aunque las temperaturas elevadas aumentan el indico de fluencia tanto en las muestras irradiadas como en las no irradiadas. Por la accion de los desechos liquidos sobre la sal se forman volumenes moderados de cloro y otros gases clorados. La migracion de los nuclidos a traves de la masa salina y la deformacion de las cavidades

  14. Strain features and condition assessment of orthotropic steel deck cable-supported bridges subjected to vehicle loads by using dense FBG strain sensors

    Science.gov (United States)

    Wei, Shiyin; Zhang, Zhaohui; Li, Shunlong; Li, Hui

    2017-10-01

    Strain is a direct indicator of structural safety. Therefore, strain sensors have been used in most structural health monitoring systems for bridges. However, until now, the investigation of strain response has been insufficient. This paper conducts a comprehensive study of the strain features of the U ribs and transverse diaphragm on an orthotropic steel deck and proposes a statistical paradigm for crack detection based on the features of vehicle-induced strain response by using the densely distributed optic fibre Bragg grating (FBG) strain sensors. The local feature of strain under vehicle load is highlighted, which enables the use of measurement data to determine the vehicle loading event and to make a decision regarding the health status of a girder near the strain sensors via technical elimination of the load information. Time-frequency analysis shows that the strain contains three features: the long-term trend item, the short-term trend item, and the instantaneous vehicle-induced item (IVII). The IVII is the wheel-induced strain with a remarkable local feature, and the measured wheel-induced strain is only influenced by the vehicle near the FBG sensor, while other vehicles slightly farther away have no effect on the wheel-induced strain. This causes the local strain series, among the FBG strain sensors in the same transverse locations of different cross-sections, to present similarities in shape to some extent and presents a time delay in successive order along the driving direction. Therefore, the strain series induced by an identical vehicle can be easily tracked and compared by extracting the amplitude and calculating the mutual ratio to eliminate vehicle loading information, leaving the girder information alone. The statistical paradigm for crack detection is finally proposed, and the detection accuracy is then validated by using dense FBG strain sensors on a long-span suspension bridge in China.

  15. Pheromonal divergence between two strains of Spodoptera frugiperda

    NARCIS (Netherlands)

    Unbehend, M.; Hänniger, S.; Meagher, R.L.; Heckel, D.G.; Groot, A.T.

    2013-01-01

    Spodoptera frugiperda consists of two genetically and behaviorally different strains, the corn- and the rice-strain, which seem to be in the process of sympatric speciation. We investigated the role of strain-specific sexual communication as a prezygotic mating barrier between both strains by

  16. MM98.83 Quantification of Combined Strain Paths

    DEFF Research Database (Denmark)

    Nielsen, Morten Sturgård; Lindegren, Maria; Wanheim, Tarras

    1998-01-01

    When working with processes where large plastic deformation occurs, a way of desribing the deformation process is to view the whole deformation history as a curve in the 6-dimensional shear strain normal strain space, henceforth called a strain history curve (SHC). This paper focuses on the SHC...... 3D-plasticity. Adirect use of the SHC, is to measure the yield surface at different points at a SHC, thus establishing data describing the importance of strain rotations or even strain reversals within a process. Two subcases for displaying SHC will be mentioned:The plane strain case and the single...

  17. Development of piping strain sensor for stress evaluation

    International Nuclear Information System (INIS)

    Takahama, Tsunemichi; Nishimura, Kazuma; Ninomiya, Seiichiro; Matsumoto, Yoshihiro; Harada, Yutaka

    2014-01-01

    In a small diameter piping, stresses are generated due to internal fluid or pump vibrations especially around the welding parts. Authors have successfully developed a pipe strain sensor which is able to measure such stresses. Unlike conventional methods using strain gages and adhesive bond, the sensor can measure the strain without putting adhesive bond on the piping surface. However, the strain sensor can provide measurements with a level of accuracy equivalent to that of conventional method using strain gages and adhesive bond. Accordingly, the strain sensor can significantly reduce the working time without any loss of the measurement accuracy. (author)

  18. Measuring systolic ankle and toe pressure using the strain gauge technique--a comparison study between mercury and indium-gallium strain gauges

    DEFF Research Database (Denmark)

    Broholm, Rikke; Wiinberg, Niels; Simonsen, Lene

    2014-01-01

    BACKGROUND: Measurement of the ankle and toe pressures are often performed using a plethysmograph, compression cuffs and a strain gauge. Usually, the strain gauge contains mercury but other alternatives exist. From 2014, the mercury-containing strain gauge will no longer be available in the Europ......BACKGROUND: Measurement of the ankle and toe pressures are often performed using a plethysmograph, compression cuffs and a strain gauge. Usually, the strain gauge contains mercury but other alternatives exist. From 2014, the mercury-containing strain gauge will no longer be available...... in the European Union. The aim of this study was to compare an indium-gallium strain gauge to the established mercury-containing strain gauge. METHODS: Consecutive patients referred to the Department of Clinical Physiology and Nuclear Medicine at Bispebjerg and Frederiksberg Hospitals for measurements of systolic...... ankle and toe pressures volunteered for the study. Ankle and toe pressures were measured twice with the mercury and the indium-gallium strain gauge in random order. Comparison of the correlation between the mean pressure using the mercury and the indium-gallium device and the difference between the two...

  19. STRAINED OFF BREAST MILK: PRO AND CONTRA

    Directory of Open Access Journals (Sweden)

    O.L. Lukoyanova

    2010-01-01

    Full Text Available The questions of feeding of children with strained off breast milk are discussed in this article. Author presents medical indications to such type of feeding, peculiarities and rules of storage of strained off milk. There is a brief literature review on the influence of different factors on the composition of strained off breast milk.Key words: strained milk, breast feeding, pasteurization, freezing.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(2:70-73

  20. Uso de águas salinas como alternativa na irrigação e produção de forragem no semiárido nordestino

    Directory of Open Access Journals (Sweden)

    José L. de A. Silva

    Full Text Available RESUMO A produção de forragem no semiárido brasileiro é limitada, em virtude da variação da quantidade e qualidade da água, e ainda dos solos encontrados na região. Nesse contexto foi desenvolvido um experimento na Universidade Federal Rural do Semi-Árido - UFERSA, em Mossoró-RN. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 3, com três repetições. Os tratamentos resultaram da combinação de dois tipos de solos, um Argissolo Vermelho-Amarelo eutrófico (PVAe e um Cambissolo Háplico Ta eutrófico (CXve, com três níveis de salinidade da água de irrigação (A1 - 0,59; A2 - 2,75 e A3 - 5,00 dS m-1. As culturas utilizadas no experimento foram milho e sorgo. As variáveis analisadas ao final do experimento foram: área foliar, matéria seca e teor de proteína bruta. A resposta das culturas à salinidade é dependente das características físicas do solo, sendo mais tolerantes em solo com menor teor de argila. A mistura de águas salinas possibilita a produção satisfatória de forragem sem reduzir o teor protéico. A mistura de águas até se obter condutividade elétrica de 2,75 dS m-1 possibilita economia de 43,3% na água de boa qualidade, com perda de aproximadamente 22% na produção de biomassa.