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Sample records for sensitive magnolia ovata

  1. [Plantago ovata].

    PubMed

    Ceranić, M; Kecmanović, D; Pavlov, M; Sepetkovski, A; Kovacević, P; Stamenković, A; Masirević, V; Ranković, V

    2006-01-01

    Plantago ovata is a high fibre bulk forming laxative. It absorbs water and expands to provide increased bulk and moisture content to the stool. The increased bulk encourages normal peristalsis and bowel motility. Clinical Indications: Constipation, Fecal Incontinence, Hemorrhoids, Ulcerative Colitis, Appetite, Hyperlipidemia, Diabetes mellitus. PMID:16989139

  2. Origin and History of Magnolias

    NASA Astrophysics Data System (ADS)

    Hebda, R. J.; Irving, E.

    2004-12-01

    The classic disjunct distribution of living magnolias between southeast Asia and the Americas has been a puzzle for more than a century and a half. We propose a scheme for the origin and history of magnolias to explain this distribution by integrating paleogeographic, paleoclimatic, paleobotanical, and phytogeographic data. Our scheme is based on paleomagnetically determined latitudes. We assume that the moist warm temperate climate favoured by most extant magnolias has always been their preference. Molecular analyses (largely chloroplast DNA) reveal that several North American species are distinct and basal forms suggesting that magnolias likely originated in North America, a conclusion supported by the fossil record. We identify four evolutionary stages: (1) Ancestral magnolias originate in the Late Cretaceous of North America in high mid-latitudes (45° -60° N) at low altitudes under greenhouse climates. (2) During the exceptionally warm climate (super-greenhouse) of the Eocene, magnolias spread eastwards via the Iceland-Faroes isthmuses, to Europe and then across west and central Asia possibly to east Asia, still at low altitudes and high mid-latitudes. (3) With global cooling from the mid-Cenozoic, magnolias shift their core range to lower mid-latitudes (30° -45° N), become extinct in Europe and southern Siberia, breaking the once continuous distribution into two. (4) In the late Cenozoic, as ice-house conditions develop, magnolias diversify rapidly and expand southward into moist warm temperate uplands in newly uplifted mountain ranges of South and Central America, southeast Asia and the High Archipelago between southeast Asia and Australia. The late Cenozoic evolution of magnolias is characterized by the impoverishment of northerly species and diversification of southerly species. Thus, the centre of origin is not the center of diversity today. Disjunction at the generic level likely occurred as part of the mid-Tertiary southward displacement of the

  3. Anti-Oxidative Abilities of Essential Oils from Atractylodes ovata Rhizome

    PubMed Central

    Wang, Kun-Teng; Chen, Lih-Geeng; Chou, Duen-Suey; Liang, Wen-Li; Wang, Ching-Chiung

    2011-01-01

    The rhizome of Atractylodes ovata De Candolle is rich in essential oils, which are usually removed by processing. In this study, anti-oxidative abilities of essential oils and aqueous extracts of A. ovata rhizome were explored, and the influence of processing on the anti-oxidative abilities was examined. Essential oils and aqueous extracts of A. ovata were extracted by boiling water and steam distillation, respectively. Quality of these two A. ovata samples was controlled by HPLC and GC-MS system, and anti-oxidative abilities were then evaluated. Results showed that surface color of A. ovata turned to brown and chemical components were changed by processing. Contents of both atractylon and atractylenolide II decreased in the essential oils, but only the contents of atractylon decreased by processing. Atractylenolide III increased in both A. ovata samples. However, A. ovata essential oils displayed stronger anti-oxidative abilities than aqueous extracts in DPPH-scavenging, TBH-induced lipid peroxidation and catalase activity assays. Moreover, the bioactivity of essential oils from raw A. ovata was stronger than oils from processed A. ovata. On the other hand, cytotoxicity of A. ovata essential oils was stronger than that of aqueous extracts, and was more sensitive on H9C2 cell than NIH-3T3 and WI-38 cells. In contrast, stir-frying processing method increased cytotoxicity of essential oils, but the cytotoxicity was ameliorated when processed with assistant substances. The results suggested that phytochemical components and bioactivity of A. ovata were changed after processing and the essential oils from raw A. ovata showed better anti-oxidative and fewer cytotoxicity effects. PMID:21799672

  4. [Plantago ovata (Laxomucil) after hemorrhoidectomy].

    PubMed

    Kecmanović, D; Pavlov, M; Ceranić, M; Sepetkovski, A; Kovacević, P; Stamenković, A; Masirević, V; Ranković, V

    2004-01-01

    The aim of this prospective randomized study is to describe the effects of laxative plantago ovata after open hemorrhoidectomy (Milligan-Morgan). Sixty patients divided into 2 equal groups were included in this study. The first group was treated postoperatively with 2 sachets of bulk agent Laxomucil (3.26 g plantago ovata), twice daily, for a period of twenty days, while the control group was treated with glycerin oil. The p.ovata group patients had a statistically significant shorter postoperative length of hospital stay (2.9 v.s. 4.1 days). Pain after stool was statistically significant more tolerable in the p.ovata group. In conclusion, the application of bulk agent plantago ovata after hemorrhoidectomy shortens the mean postoperative hospital stay, expedites digestive function recovery and lessens the pain after stool. PMID:16018379

  5. Montessori for All: Magnolia Montessori

    ERIC Educational Resources Information Center

    EDUCAUSE, 2015

    2015-01-01

    The founders of Montessori For All, which opened Magnolia Montessori--a PK-8 public charter school in Austin, Texas--created a new school model that blends the best of authentic Montessori schooling (hands-on and self-directed learning) with best practices from high-performing charter schools (basic skills mastery to excel on standardized tests…

  6. Toxic effects of harmful benthic dinoflagellate Ostreopsis ovata on invertebrate and vertebrate marine organisms.

    PubMed

    Faimali, Marco; Giussani, Valentina; Piazza, Veronica; Garaventa, Francesca; Corrà, Christian; Asnaghi, Valentina; Privitera, Davide; Gallus, Lorenzo; Cattaneo-Vietti, Riccardo; Mangialajo, Luisa; Chiantore, Mariachiara

    2012-05-01

    sensitive species even at concentrations below the Environmental Alarm Threshold set by the Italian Ministry of Health. Some possible explanations of such sensitivity are discussed, taking into account evidence of O. ovata cells ingestion and the activity of its toxins on the Na⁺/K⁺-ATPase. PMID:22000703

  7. 75 FR 11936 - Unit Structures LLC, Magnolia, AR; Notice of Termination of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Unit Structures LLC, Magnolia, AR; Notice of Termination of... of workers of Unit Structures LLC, Magnolia, Arkansas. The petitioner has requested that the...

  8. Sesquiterpenoid tropolone glycosides from Liriosma ovata.

    PubMed

    Ma, Jun; Pawar, Rahul S; Grundel, Erich; Mazzola, Eugene P; Ridge, Clark D; Masaoka, Takashi; Le Grice, Stuart F J; Wilson, Jennifer; Beutler, John A; Krynitsky, Alexander J

    2015-02-27

    Two new sesquiterpenoid tropolone glycosides, liriosmasides A (1) and B (2), along with two known compounds, secoxyloganin and oplopanpheside C, were isolated from a methanol extract of the roots of Liriosma ovata. The structures of 1 and 2 were elucidated by spectroscopic methods including 1D and 2D NMR and by high-resolution mass spectrometry involving an ultra-high-performance liquid chromatography-quadrupole-orbital ion trap mass spectrometric (UHPLC-Q-Orbitrap MS) method. Compound 1 showed weak inhibitory activity against HIV RNase H. PMID:25587934

  9. Biogeographic Patterns Between Bacterial Phyllosphere Communities of the Southern Magnolia (Magnolia grandiflora) in a Small Forest.

    PubMed

    Stone, Bram W G; Jackson, Colin R

    2016-05-01

    The phyllosphere presents a unique system of discrete and easily replicable surfaces colonized primarily by bacteria. However, the biogeography of bacteria in the phyllosphere is little understood, especially at small to intermediate scales. Bacterial communities on the leaves of 91 southern magnolia (Magnolia grandiflora) trees 1-452 m apart in a small forest plot were analyzed and fragments of the 16S ribosomal RNA (rRNA) gene sequenced using the Illumina platform. Assemblages were dominated by members of the Alphaproteobacteria, Bacteroidetes, and Acidobacteria. Patterns in community composition were measured by both relative abundance (theta) and presence-absence (Jaccard) dissimilarity metrics. Distance-based Moran's eigenvector map analyses of the distance-decay relationship found a significant, positive relationship between each dissimilarity metric and significant eigenfunctions derived from geographic distance between trees, indicating trees that were closer together had more similar bacterial phyllosphere communities. Indirect gradient analyses revealed that several environmental parameters (canopy cover, tree elevation, and the slope and aspect of the ground beneath trees) were significantly related to multivariate ordination scores based on relative bacterial sequence abundances; however, these relationships were not significant when looking at the incidence of bacterial taxa. This suggests that bacterial growth and abundance in the phyllosphere is shaped by different assembly mechanisms than bacterial presence or absence. More broadly, this study demonstrates that the distance-decay relationship applies to phyllosphere communities at local scales, and that environmental parameters as well as neutral forces may both influence spatial patterns in the phyllosphere. PMID:26883131

  10. Philometra ovata (Nematoda: Philometroidea): a potential sentinel species of heavy metal accumulation.

    PubMed

    Barus, V; Jarkovský, J; Prokes, M

    2007-04-01

    To assess the bioindicator value of parasites, the concentrations of six heavy metals (Cr, Cu, Pb, Cd, Ni and Zn) were analyzed by atomic absorption spectrometry in gravid females of the nematode Philometra ovata, body cavity parasites of gudgeon (Gobio gobio) and muscle samples of infected and uninfected hosts. The concentration of heavy metals was significantly higher in specimens of P. ovata compared to the host muscle tissue. The parasite-to-muscle ratio of heavy metals varied from 3.2 to 121.7, in increasing concentrations for Cr, Cd, Cu, Pb, Ni and Zn. The presence of parasites did not influence the heavy metal content of the hosts, and no significant differences were found between muscle tissues of parasitized and non-parasitized fishes. The bioconcentration factor (BF = Cparasite/Csediment)varied between 0.4 and 25.8, in increasing order for Cd, Zn, Cu, Pb, Ni and Cr. These results indicate that P. ovata may serve as sensitive indicator species of heavy metal pollution in freshwater ecosystems. PMID:17149604

  11. Plantago ovata: Clinical study of overuse.

    PubMed

    Agha, Rukh-e-Nasreen; Saeed, Aftab; Nazar, Halima

    2016-03-01

    The objective of the study was to undertake evidence-base study to evaluate clinical manifestation of the over-estimated use of herbal drug Plantago ovata and to compare it with placebo for the efficacy and adverse effects. The patients of both genders were included. Blood urea, creatinine, ALT, Serum B12, CP, ESR and liver function tests were performed. The data was statistically analyzed in both groups for differential symptomatology. In anorexia test verses control results showed that Plantago ovata husk and placebo showed the affected ratio as 81 percent and 50 percent, correspondingly. Whereas in clinical performance of heart burning, pain in epigastrium, low libido, body pain, dyspepsia, fever, burning sensation in palm and sole in test drug showed affected response as adverse effect 90%, 88% and as control drug, 36%, 29%, 22%, 25%, 38%, 30%, 33%, 57%, respectively. The results were highly marked in test drug i.e. in comparison with placebo. This is clearly evident from data analysis that effect observed in test arm is far more superior hence null hypothesis was rejected clearly. Similarly serological and biochemical reports study i.e. (ALT, Vit. B1 and Vit A) revealed that there is no hepatotoxic and neurotoxic effect found in both the drugs. PMID:27087080

  12. The complete mitochondrial genome of Solea ovata (Pleuronectiformes: Soleidae).

    PubMed

    Shi, Wei; Gong, Li; Wang, Shu-Ying; Kong, Xiao-Yu

    2014-12-01

    Solea ovata (Pleuronectiformes: Soleidae) is characterized by eyes on right side and an ovata body with small ctenoid scales on both sides. In this article, the complete mitogenome of Solea ovata was first determined. The total length is 16,782 bp, containing 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes (12S and 16S), as well as a putative control region and a L-strand replication origin (OL). Except eight tRNA and ND6 genes, all other mitochondrial genes are encoded on the heavy strand. Overall base composition is 29.2% A, 29.4% C, 15.9% G, and 25.5% T with a slight AT bias of 54.7%. The determination of S. ovata complete mitogenome could contribute to understanding the systematic evolution of the genus Solea and further phylogenetic study on Soleidae and Pleuronectiformes. PMID:23901931

  13. A Comprehensive Evaluation of Yellow-flowering Magnolias

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A collection of yellow-flowering magnolias were evaluated for flower color, bloom duration and growth rate in USDA Hardiness Zone 6b. All selections were reported to have yellow blooms; however, tepal color in this test ranged from light pink with some yellow coloration to dark yellow. The darkest...

  14. Cumberland Extension entering Magnolia Bend in West Virginia. After passing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cumberland Extension entering Magnolia Bend in West Virginia. After passing over the Third Potomac and C&O Canal Crossing, the line curves over the former B&O Railroad at Bridge No. 1363, First B&O Crossing in foreground, looking northeast. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  15. 75 FR 29656 - Amendment of Class E Airspace; Magnolia, AR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... Municipal Airport (75 FR 5904) Docket No. FAA-2009-1179. The Magnolia NDB is being decommissioned and...) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26.... 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0 2. The incorporation by reference in...

  16. Fertilization and early development in Beroe ovata.

    PubMed

    Carré, D; Sardet, C

    1984-09-01

    Fertilization in the clear egg (1 mm in diameter) of the ctenophore Beroe ovata and, in particular, the positioning and movements of pronuclei, and their relationship to the larval oral-aboral axis have been observed. Fertilization can take place anywhere on the egg surface. The sperm pronucleus remains at its entry site and becomes surrounded by a specialized zone (30-50 micron in diameter) beneath the surface referred to as the sperm pronuclear zone or SPZ and devoid of large cortical granules. Polyspermy has been observed to be frequent; each pronucleus is surrounded by its own SPZ. Only the egg pronucleus migrates with a continuous velocity (averaging 18 micron/min) and moves beneath the surface directly toward the immobile sperm pronucleus. In polyspermic eggs, the egg pronucleus can probe several SPZ, each containing a single sperm nucleus, before it finally enters one SPZ and fuses with the chosen sperm pronucleus. These migrations of the egg pronucleus occur over several millimeters and take hours, but the mechanism underlying the motion or how the egg pronucleus decides which SPZ to enter is not yet known. Under our experimental conditions the mitotic apparatus and the first cleavage plane which defines the oral-aboral axis of the larva (see Reverberi (1971). "Experimental Embryology of Marine and Fresh-Water Invertebrates." North-Holland, Amsterdam. for review) pass through the point of sperm entry. During fertilization and cleavage, movements of a cortical autofluorescent material are clearly seen. This material is segregated into micromeres as cleavage progresses. PMID:6147287

  17. Characteristics of pronuclear migration in Beroe ovata.

    PubMed

    Rouvière, C; Houliston, E; Carré, D; Chang, P; Sardet, C

    1994-01-01

    In the large eggs (approximately 1 mm) of the ctenophore Beroe ovata, female pronuclei migrate long distances to join stationary male pronuclei in the peripheral cytoplasm that surrounds the yolky interior. We have investigated the mechanism of nuclear migration using time lapse video recording, automated image analysis, visualization of microtubules by immunofluorescence and rhodamine-tubulin injection, and electron microscopy. Female pronuclei migrated at average speeds of 0.2 microns/sec, and were found to show periodic oscillations in velocity. Alternating phases of acceleration and deceleration occurred with an average periodicity of 235 seconds covering distances of 47 microns (about 3 times the nuclear diameter). Migration velocities and velocity oscillations were similar in fertilized and unfertilized eggs; however, changes in migration direction were much more frequent in unfertilized eggs. Characteristic deformations of the pronuclear membrane and occasional rotation of the nuclear contents were observed during migration. Inhibitor studies indicated that microtubules are required for nuclear migration. In fertilized eggs the top of the nucleus was found to move through the dense layer of aligned sperm aster microtubules. The frequent changes in direction of pronuclear migration in unfertilized eggs reflect the random organization of the microtubule layer in the absence of sperm derived centrosomes. Densely packed endoplasmic reticulum was found intermeshed with sperm aster microtubules and connected extensively with the nuclear membrane during migration. Most nuclear pores were grouped in an infolding of the nuclear membrane. We suggest that in fertilized eggs the female pronucleus is transported to the minus ends of sperm aster microtubules using motor molecules attached either to the outer nuclear membrane and/or to the network of connecting ER. PMID:7859293

  18. 76 FR 25319 - Magnolia Water LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... Energy Regulatory Commission Magnolia Water LLC; Notice of Preliminary Permit Application Accepted for..., Magnolia Water LLC filed an application, pursuant to section 4(f) of the Federal Power Act, proposing to... reservoirs; (6) a powerhouse/pumping station containing 3 pump/ generating units with a total...

  19. Phenylethanoid glycosides in tepals of Magnolia salicifolia and their occurrence in flowers of Magnoliaceae.

    PubMed

    Porter, Elaine A; Kite, Geoffrey C; Veitch, Nigel C; Geoghegan, Ivey A; Larsson, Sonny; Simmonds, Monique S J

    2015-09-01

    Phenylethanoid glycosides were among the major UV-absorbing components in 80% aq. CH3OH extracts of the tepals of Magnolia salicifolia (Siebold & Zucc.) Maxim. (Magnoliaceae; Magnolia subgenus Yulania). Structural characterisation of isolated compounds by spectroscopic and chemical methods revealed three previously unrecorded examples, yulanoside A, yulanoside B and 2'-rhamnoechinacoside, and the known compounds echinacoside and crassifolioside; chromatographic methods also identified verbascoside in the tepal extract. Yulanoside A is the first reported example of a phenylethanoid pentaglycoside, namely hydroxytyrosol 1-O-{β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-[3,4-dihydroxycinnamoyl-(→4)][α-L-rhamnopyranosyl-(1→3)][α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside}. A survey of Magnolia sensu lato and Liriodendron (the two genera of Magnoliaceae) suggested that yulanoside A and its deglucosyl derivative (yulanoside B) were a feature of the tepal chemistry of Magnolia subgenus Yulania (except Magnolia acuminata, the sole member of section Tulipastrum, which did not accumulate phenylethanoid glycosides). The two species of Liriodendron and examined examples of Magnolia subgenus Magnolia sections Magnolia and Rytidospermum (subsection Oyama) also accumulated phenylethanoid glycosides in their tepals and in these species, and in subgenus Yulania, the major compounds were one or more of echinacoside, 2'-rhamnoechinacoside, crassifolioside and verbascoside. Levels of phenylethanoid glycosides were found to be much lower in species studied from Magnolia sections Gwillimia, Macrophylla and Rytidospermum (subsection Rytidospermum), although yulanoside A was detectable in M. macrophylla and this may have some bearing on the placement of section Macrophylla, which is currently uncertain. In the isolates of yulanoside B and echinacoside, minor phenylethanoid glycosides were determined to be analogues of these compounds with β-D-xylose at C-3' of the

  20. Monitoring toxic Ostreopsis cf. ovata in recreational waters using a qPCR based assay.

    PubMed

    Casabianca, Silvia; Perini, Federico; Casabianca, Anna; Battocchi, Cecilia; Giussani, Valentina; Chiantore, Mariachiara; Penna, Antonella

    2014-11-15

    Ostreopsis sp. is a toxic marine benthic dinoflagellate that causes high biomass blooms, posing a threat to human health, marine biota and aquaculture activities, and negatively impacting coastal seawater quality. Species-specific identification and enumeration is fundamental because it can allow the implementation of all the necessary preventive measures to properly manage Ostreopsis spp. bloom events in recreational waters and aquaculture farms. The aim of this study was to apply a rapid and sensitive qPCR method to quantify Ostreopsis cf. ovata abundance in environmental samples collected from Mediterranean coastal sites and to develop site-specific environmental standard curves. Similar PCR efficiencies of plasmid and environmental standard curves allowed us to estimate the LSU rDNA copy number per cell. Moreover, we assessed the effectiveness of mitochondrial COI and cob genes as alternative molecular markers to ribosomal genes in qPCR assays for Ostreopsis spp. quantification. PMID:25282181

  1. Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis.

    PubMed

    Ho, K Y; Tsai, C C; Chen, C P; Huang, J S; Lin, C C

    2001-03-01

    The antimicrobial activity of honokiol and magnolol, the main constituents of Magnolia officinalis was investigated. The antimicrobial activity was assayed by the agar dilution method using brain heart infusion medium and the minimum inhibitory concentration (MIC) were determined for each compound using a twofold serial dilution assay. The results showed that honokiol and magnolol have a marked antimicrobial effect (MIC = 25 microg/mL) against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus and Bacillus subtilis, but did not show antimicrobial activity (MIC > or = 100 microg/mL) for Shigella flexneii, Staphylococcus epidermidis, Enterobacter aerogenes, Proteus vulgaris, Escherichia coli and Pseudomonas aeruginosa. Our results indicate that honokiol and magnolol, although less potent than tetracycline, show a significant antimicrobial activity for periodontal pathogens. Hence we suggest that honokiol and magnolol might have the potential to be an adjunct in the treatment of periodontitis. PMID:11268114

  2. [Effects of primary processing on quality of cortex Magnolia officinalis].

    PubMed

    Yu, Shengxian; Zhang, Chunxia; Chen, Chengyu; Yan, Renyi; Yang, Bin; Liao, Chaolin; You, Jinwen

    2010-07-01

    In this paper, the changes of volatile oil and non-volatile ingredients in Cortex Magnolia Officinalis before and after primary processing were determined by an HPLC and a GC-MS method. The method is based on quantitative determination of three index ingredients, beta-eudesmol, honokiol and magnolol, and on qualitative fingerprinting analysis using HPLC and GC. Big differences were observed between processed and unprocessed samples according to their chromatographic fingerprinting data calculated by statistic software. Compared with unprocessed samples, the contents of honokiol and magnolol in processed samples increased, whereas the contents of beta-eudesmol and magnoloside A in processed samples decreased. Magnoloside A was isolated from this plant for the first time. PMID:20939279

  3. [Study of the new settler Beroe ovata in the Black sea].

    PubMed

    Shiganova, T A; Bulgakova, Iu V; Sorokin, P Iu; Lukashev, Iu F

    2000-01-01

    Primary data on population, size, and distribution of a new settler--comb jelly Beroe ovata--in the Black Sea are presented. We studied certain aspects of its nutrition, consumed organisms, and digestion time. Comb jellies Mnemiopsis leidyi and Pleurobachia pileus were established as the nutritional targets of B. ovata. Mnemiopsis proved to be more accessible and assimilable. Preliminary data on metabolic level and threshold oxygen content in B. ovata were obtained; proportions of dry and wet weight of B. ovata were determined. Population changes of new settler Mnemiopsis and other jellylike animals in the Northeast part of the sea induced by B. ovata were analyzed. We observed sharp decrease in population of Mnemiopsis, a species that induced degradation of the Black Sea ecosystem within the last decade. PMID:10780118

  4. Comparative study of the chemical composition and biological activities of Magnolia grandiflora and Magnolia virginiana flower essential oils.

    PubMed

    Farag, Mohamed A; Al-Mahdy, Dalia A

    2013-01-01

    The biological activities and the determined major volatile components in the Magnolia grandiflora and M. virginiana flowers extracts were compared. Volatile components were detected in the essential oil by dynamic headspace sampling (HS). 2-Phenylethanol (40% and 61%) was found as the main constituent in the essential oil and HS samples of M. virginiana, respectively. In the M. grandiflora oil sample, (E,E)-farnesol (18%) and 2-phenylethanol (10%) were found as main constituents, whereas germacrene D (17%) and β-bisabolene (17%) were the main components of the HS sample. The essential oil in M. virginiana displayed a moderate antioxidant activity relative to vitamin E, whereas both essential oils were active against human lung carcinoma and breast carcinoma cell lines, even at concentrations higher than 200 µg mL(-1). PMID:22690913

  5. Genetic diversity of Ostreopsis ovata (Dinophyceae) from Malaysia.

    PubMed

    Pin, L C; Teen, L P; Ahmad, A; Usup, G

    2001-05-01

    The genus Ostreopsis is an important component of benthic and epiphytic dinoflagellate assemblages in coral reefs and seaweed beds of Malaysia. Members of the species may produce toxins that contribute to ciguatera fish poisoning. In this study, two species have been isolated and cultured, Ostreopsis ovata and Ostreopsis lenticularis. Analyses of the 5.8S subunit and internal transcribed spacer regions ITS1 and ITS2 of the ribosomal RNA gene sequences of these two species showed that they are separate species, consistent with morphological designations. The nucleotide sequences of the 5.8S subunit and ITS1 and ITS2 regions of the rRNA gene were also used to evaluate the interpopulation and intrapopulation genetic diversity of O. ovata found in Malaysian waters. Results showed a low level of sequence divergence within populations. At the interpopulation level, the rRNA gene sequence distinguished two groups of genetically distinct strains, representative of a Malacca Straits group (isolates from Port Dickson) and a South China Sea group (isolates from Pulau Redang and Kota Kinabalu). Part of the sequences in the ITS regions may be useful in the design of oligonucleotide probes specific for each group. Results from this study show that the ITS regions can be used as genetic markers for taxonomic, biogeographic, and fine-scale population studies of this species. PMID:14961362

  6. Plantago ovata Mucilage in the Design of Fast Disintegrating Tablets.

    PubMed

    Shirsand, S B; Suresh, Sarasija; Para, M S; Swamy, P V; Kumar, D Nagendra

    2009-01-01

    In the present work, fast disintegrating tablets of prochlorperazine maleate were designed with a view to enhance patient compliance by direct compression method. In this method mucilage of Plantago ovata and crospovidone were used as superdisintegrants (2-8% w/w) along with microcrystalline cellulose (20-60% w/w) and directly compressible mannitol (Pearlitol SD 200) to enhance mouth feel. The prepared batches of tablets were evaluated for hardness, friability, drug content uniformity, wetting time, water absorption ratio and in vitro dispersion time. Based on in vitro dispersion time (approximately 8 s), the two formulations were tested for the in vitro drug release pattern (in pH 6.8 phosphate buffer), short-term stability (at 40 degrees /75% relative humidity for 3 mo) and drug-excipient interaction (IR spectroscopy). Among the two promising formulations, the formulation prepared by using 8% w/w of Plantago ovata mucilage and 60% w/w of microcrystalline cellulose emerged as the overall best formulation (t(50%) 3.3 min) based on the in vitro drug release characteristics compared to conventional commercial tablets formulation (t(50%) 17.4 min). Short-term stability studies on the formulations indicated that there are no significant changes in drug content and in vitro dispersion time (p<0.05). PMID:20177454

  7. Plantago ovata Mucilage in the Design of Fast Disintegrating Tablets

    PubMed Central

    Shirsand, S. B.; Suresh, Sarasija; Para, M. S.; Swamy, P. V.; Kumar, D. Nagendra

    2009-01-01

    In the present work, fast disintegrating tablets of prochlorperazine maleate were designed with a view to enhance patient compliance by direct compression method. In this method mucilage of Plantago ovata and crospovidone were used as superdisintegrants (2-8% w/w) along with microcrystalline cellulose (20-60% w/w) and directly compressible mannitol (Pearlitol SD 200) to enhance mouth feel. The prepared batches of tablets were evaluated for hardness, friability, drug content uniformity, wetting time, water absorption ratio and in vitro dispersion time. Based on in vitro dispersion time (approximately 8 s), the two formulations were tested for the in vitro drug release pattern (in pH 6.8 phosphate buffer), short-term stability (at 40°/75% relative humidity for 3 mo) and drug-excipient interaction (IR spectroscopy). Among the two promising formulations, the formulation prepared by using 8% w/w of Plantago ovata mucilage and 60% w/w of microcrystalline cellulose emerged as the overall best formulation (t50% 3.3 min) based on the in vitro drug release characteristics compared to conventional commercial tablets formulation (t50% 17.4 min). Short-term stability studies on the formulations indicated that there are no significant changes in drug content and in vitro dispersion time (p<0.05). PMID:20177454

  8. 78 FR 38024 - Magnolia LNG, LLC; Liquefied Natural Gas Limited; Notice of Intent To Prepare an Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Magnolia LNG, LLC; Liquefied Natural Gas Limited; Notice of Intent To Prepare an Environmental Impact Statement for the Planned Magnolia Liquefied Natural Gas Project, Request for Comments on Environmental Issues,...

  9. Simulation model of Cryptomonas ovata population dynamics in southern Kootenay Lake, British Columbia

    USGS Publications Warehouse

    Cloern, James E.

    1978-01-01

    The model simulates well the timing and magnitude of all observed population changes and, more importantly, it gives insight into the important mechanisms which regulate population density of C. ovata in this natural system.

  10. On the origin and distribution of magnolias: Tectonics, DNA and climate change

    NASA Astrophysics Data System (ADS)

    Hebda, R. J.; Irving, E.

    Extant magnolias have a classic disjunct distribution in southeast Asia and in the Americas between Canada and Brazil, and nowhere in between. Of the 17 sections (about 210 species) in two subgenera, only two, Tulipastrum and Rhytidospermum, are truly disjunct. Molecular analyses reveal that several North American species are basal forms suggesting that magnolias originated in North America, as indicated by their fossil record. We recognize four elements in their evolution. (1) Ancestral magnolias originated in the Late Cretaceous of North America in high mid-latitudes (45°-60°N) at low altitudes in a greenhouse climate. (2) During the exceptionally warm climate of the Eocene, magnolias spread eastwards, via the Disko Island and Thulean isthmuses, first to Europe, and then across Asia, still at low altitudes and high mid-latitudes. (3) With mid-Cenozoic global cooling, they shifted to lower mid-latitudes (30°-45°N), becoming extinct in Europe and southern Siberia, dividing a once continuous distribution into two, centred in eastern Asia and in North America. (4) In the late Cenozoic, as ice-house conditions developed, magnolias migrated southward from both centres into moist warm temperate upland sites in the newly uplifted mountains ranges of South and Central America, southeast Asia, and the High Archipelago, where they diversified. Thus the late Cenozoic evolution of magnolias is characterized by impoverishment of northern and diversification of southern species, the latter being driven by a combination of high relief and climate oscillations, and neither of the present centers of diversity is the center of origin. Disjunction at the generic level and within section Tulipastrum likely occurred as part of the general mid-Cenozoic southward displacement assisted by the development of north-south water barriers, especially the Turgai Strait across western Siberia. Disjunction in section Rhytidospermum could be Neogene.

  11. Ostreopsis cf. ovata dynamics in the NW Mediterranean Sea in relation to biotic and abiotic factors.

    PubMed

    Carnicer, Olga; Guallar, Carles; Andree, Karl B; Diogène, Jorge; Fernández-Tejedor, Margarita

    2015-11-01

    An expansion of the distribution of Ostreopsis cf. ovata, a dinoflagellate which produces palytoxin-like compounds, has been reported in recent years. Economical and social interests are affected by blooms, as they are responsible for respiratory and skin problems in humans and may cause damage to marine organisms. In order to identify the most influential environmental factors that trigger proliferations of O. cf. ovata in the area of the adjacent shallow rocky coast of the Ebro Delta (NW Mediterranean Sea) a three-year survey was performed on the metaphytic microalgae community growing on the macrophytes Jania rubens and Corallina elongata. Small-size diatoms were more abundant than dinoflagellates; O. cf. ovata was identified as the only species present from the genus. Seawater temperature was the primary driver defining the ecological niche of O. cf. ovata. Freshwater and groundwater fluxes were more pronounced in southern than in northern sites, which may have resulted in a distinct O. cf. ovata spatial distribution, with the highest records of abundance and more frequent blooms in the north. In consequence, negative correlations between the abundance of O. cf. ovata and nitrate concentrations and significant positive correlation with salinity were observed. The temporal pattern of O. cf. ovata dynamics from mid-July to early-November is probably due to the fact that this species is observed only above a certain threshold temperature of seawater. Metaphytic cells of O. cf. ovata were smaller in the northern site than in the south, possibly as a result of an increase in cell division, coinciding with higher abundance, and this could be an indicator of favorable conditions. Toxicity in planktonic cells was negatively correlated with cell abundance in the water column, achieving maximum concentrations of 25pg. PLTX eqcell(-1). PMID:26365038

  12. Capparis ovata modulates brain oxidative toxicity and epileptic seizures in pentylentetrazol-induced epileptic rats.

    PubMed

    Nazıroğlu, Mustafa; Akay, Mehmet Berk; Çelik, Ömer; Yıldırım, Muhammed İkbal; Balcı, Erdinç; Yürekli, Vedat Ali

    2013-04-01

    It has been widely suggested that oxidative stress products play an important role in the pathophysiology of epilepsy. Capparis ovata (C. ovata) may useful treatment of epilepsy because it contains antioxidant flavonoids. The current study was designed to determine the effects of C. ovata on lipid peroxidation, antioxidant levels and electroencephalography (EEG) records in pentylentetrazol (PTZ)-induced epileptic rats. Thirty-two rats were randomly divided into four groups. First group was used as control although second group was PTZ group. Oral 100 and 200 mg/kg C. ovata were given to rats constituting the third and fourth groups for 7 days before PTZ administration. Second, third and forth groups received 60 mg/kg PTZ for induction of epilepsy. Three hours after administration of PTZ, EEG records, brain cortex and blood samples were taken all groups. The lipid peroxidation levels of the brain cortex, number of spikes and epileptiform discharges of EEG were higher in PTZ group than in control and C. ovata group whereas they were decreased by C. ovata administration. Vitamin A, vitamin C, vitamin E and β-carotene concentrations of brain cortex and latency to first spike of EEG were decreased by the PTZ administration although the brain cortex and plasma vitamin concentrations, and brain cortex and erythrocyte glutathione and glutathione peroxidase values were increased in PTZ + 100 and PTZ + 200 mg C. ovata groups. In conclusion, C. ovata administration caused protection against the PTZ-induced brain oxidative toxicity by inhibiting free radical and epileptic seizures, and supporting antioxidant redox system. PMID:23389657

  13. Molecular cloning and biochemical characterization of a novel erythrose reductase from Candida magnoliae JH110

    PubMed Central

    2010-01-01

    Background Erythrose reductase (ER) catalyzes the final step of erythritol production, which is reducing erythrose to erythritol using NAD(P)H as a cofactor. ER has gained interest because of its importance in the production of erythritol, which has extremely low digestibility and approved safety for diabetics. Although ERs were purified and characterized from microbial sources, the entire primary structure and the corresponding DNA for ER still remain unknown in most of erythritol-producing yeasts. Candida magnoliae JH110 isolated from honeycombs produces a significant amount of erythritol, suggesting the presence of erythrose metabolizing enzymes. Here we provide the genetic sequence and functional characteristics of a novel NADPH-dependent ER from C. magnoliae JH110. Results The gene encoding a novel ER was isolated from an osmophilic yeast C. magnoliae JH110. The ER gene composed of 849 nucleotides encodes a polypeptide with a calculated molecular mass of 31.4 kDa. The deduced amino acid sequence of ER showed a high degree of similarity to other members of the aldo-keto reductase superfamily including three ER isozymes from Trichosporonoides megachiliensis SNG-42. The intact coding region of ER from C. magnoliae JH110 was cloned, functionally expressed in Escherichia coli using a combined approach of gene fusion and molecular chaperone co-expression, and subsequently purified to homogeneity. The enzyme displayed a temperature and pH optimum at 42°C and 5.5, respectively. Among various aldoses, the C. magnoliae JH110 ER showed high specific activity for reduction of erythrose to the corresponding alcohol, erythritol. To explore the molecular basis of the catalysis of erythrose reduction with NADPH, homology structural modeling was performed. The result suggested that NADPH binding partners are completely conserved in the C. magnoliae JH110 ER. Furthermore, NADPH interacts with the side chains Lys252, Thr255, and Arg258, which could account for the enzyme

  14. First record of Botryosphaeria ribis associated with leaf spots on Magnolia aff. candollei in Brazil

    PubMed Central

    de Macedo, Davi Mesquita; Barreto, Robert Weingart

    2008-01-01

    A leaf spot disease was observed attacking some Magnolia aff. candollei plants grown in a private garden in the city of Rio de Janeiro, RJ, Brazil. Such leaf spots coalesced and led to extensive blight of foliage. A fungus was clearly associated to the disease symptoms and was identified as Botryosphaeria ribis. Its anamorph, Fusicoccum ribis, was also present, although less abundant than the teleomorph. This is first report of this fungus on this host in Brazil and the first record of any fungal disease on a member of the genus Magnolia in Brazil. PMID:24031224

  15. Growth Inhibition of Sporomusa ovata by Incorporation of Benzimidazole Bases into Cobamides

    PubMed Central

    Mok, Kenny C.

    2013-01-01

    Phenolyl cobamides are unique members of a class of cobalt-containing cofactors that includes vitamin B12 (cobalamin). Cobamide cofactors facilitate diverse reactions in prokaryotes and eukaryotes. Phenolyl cobamides are structurally and chemically distinct from the more commonly used benzimidazolyl cobamides such as cobalamin, as the lower axial ligand is a phenolic group rather than a benzimidazole. The functional significance of this difference is not well understood. Here we show that in the bacterium Sporomusa ovata, the only organism known to synthesize phenolyl cobamides, several cobamide-dependent acetogenic metabolisms have a requirement or preference for phenolyl cobamides. The addition of benzimidazoles to S. ovata cultures results in a decrease in growth rate when grown on methanol, 3,4-dimethoxybenzoate, H2 plus CO2, or betaine. Suppression of native p-cresolyl cobamide synthesis and production of benzimidazolyl cobamides occur upon the addition of benzimidazoles, indicating that benzimidazolyl cobamides are not functionally equivalent to the phenolyl cobamide cofactors produced by S. ovata. We further show that S. ovata is capable of incorporating other phenolic compounds into cobamides that function in methanol metabolism. These results demonstrate that S. ovata can incorporate a wide range of compounds as cobamide lower ligands, despite its preference for phenolyl cobamides in the metabolism of certain energy substrates. To our knowledge, S. ovata is unique among cobamide-dependent organisms in its preferential utilization of phenolyl cobamides. PMID:23417488

  16. 78 FR 56170 - Radio Broadcasting Services; Magnolia, Arkansas; and Oil City, Louisiana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ..., See 70 FR 19337, April 13, 2005. In the Memorandum Opinion and Order, the Bureau affirmed the grant...-existing Tuck test. See 69 FR 8333, February 24, 2004. On review, the Commission finds that the Bureau did... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Magnolia, Arkansas; and Oil City, Louisiana...

  17. 77 FR 32631 - Lion Oil Trading & Transportation, Inc., Magnolia Pipeline Company, and El Dorado Pipeline...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lion Oil Trading & Transportation, Inc., Magnolia Pipeline Company, and El Dorado Pipeline Company; Notice for Temporary Waiver of Filing and Reporting Requirements Take notice that on May 8, 2012, pursuant to Rule...

  18. Giant Flowers of Southern Magnolia Are Hydrated by the Xylem1[OA

    PubMed Central

    Feild, Taylor S.; Chatelet, David S.; Brodribb, Tim J.

    2009-01-01

    Flowering depends upon long-distance transport to supply water for reproductive mechanisms to function. Previous physiological studies suggested that flowers operated uncoupled from stem xylem transport and received water primarily from the phloem. We demonstrate that the water balance of Southern magnolia (Magnolia grandiflora) flowers is regulated in a manner opposite from that of previously examined flowers. We show that flowers of Southern magnolia rely upon relatively efficient xylem hydraulic transport to support high water demand during anthesis. We measured rapid rates of perianth transpiration ranging from twice to 100 times greater than previous studies. We found that relatively efficient xylem pathways existed between the xylem and flower. Perianth hydraulic conductance and the amount of xylem to transpirational surface area ratios of flowers were both approximately one-third those measured for leafy shoots. Furthermore, we observed that perianth tissues underwent significant diurnal depressions in water status during transpiring conditions. Decreases in water potential observed between flowers and vegetative tissues were consistent with water moving from the stem xylem into the flower during anthesis. Xylem hydraulic coupling of flowers to the stem was supported by experiments showing that transpiring flowers were unaffected by bark girdling. With Southern magnolia being a member of a nearly basal evolutionary lineage, our results suggest that flower water balance represents an important functional dimension that influenced early flower evolution. PMID:19403730

  19. Bulk agent Plantago ovata after Milligan-Morgan hemorrhoidectomy with Ligasure.

    PubMed

    Kecmanovic, Dragutin M; Pavlov, Maja J; Ceranic, Miljan S; Kerkez, Mirko D; Rankovic, Vitomir I; Masirevic, Vesna P

    2006-08-01

    The aim of this study was to determine usefulness of the bulk agent Plantago ovata in reducing postoperative pain and tenesmus after open hemorrhoidectomy (Milligan-Morgan with Ligasure). Ninety-eight patients were randomized into two groups of 49 patients each. In both groups Milligan-Morgan open hemorrhoidectomy with Ligasure was performed. The first group received postoperatively two sachets daily of 3.26 g of the bulk agent, Plantago ovata, for 20 days. The control group was treated postoperatively with glycerin oil. There was no statistically significant difference in age, gender distribution and hemorrhoid grading, between the two groups. The pain score after first defecation (p < 0.001) and after 10 days (p < 0.01) and the global pain score (p < 0.001) was statistically significantly lower in the group treated with Plantago ovata, while there was no statistically significant difference in the pain level after 20 days (p > 0.05). The hospital stay was statistically significantly shorter in the group receiving Plantago ovata (2.6 +/- 0.6 vs 3.9 +/- 0.7 days, p < 0.001). The incidence of tenesmus was higher in the control group (40.8% vs 10.2%, p < 0.01). Treating patients with Plantago ovata after open hemorrhoidectomy, reduces pain, tenesmus rate and shortens postoperative hospital stay. PMID:16708408

  20. Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

    PubMed Central

    Chan, Lai Wah; Cheah, Emily LC; Saw, Constance LL; Weng, Wanyu; Heng, Paul WS

    2008-01-01

    Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao), Folium Murraya Koenigii (Jialiye), Rhizoma Arachis Hypogea (Huashenggen), Herba Houttuyniae (Yuxingcao), Epipremnum pinnatum (Pashulong), Rhizoma Typhonium Flagelliforme (Laoshuyu), Cortex Magnoliae Officinalis (Houpo) and Rhizoma Imperatae (Baimaogen) were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities. PMID:19038060

  1. Distribution of eu- and heterochromatin in Plantago ovata.

    PubMed

    Dhar, M K; Fuchs, J; Houben, A

    2009-01-01

    Plantago ovata (2n = 8) is the only cultivated species in the monotypic genus Plantago. The seed husk of the plant constitutes the psyllium (Isabgol) which has many medicinal properties. The 1C DNA content was determined to be 0.635 pg (621 Mb) with an AT content of 59.7%. Applying Giemsa C-banding and fluorescence in situ hybridization (FISH) using the Cot-1 fraction of DNA on prometaphase and metaphase chromosomes we investigated the chromosomal distribution of eu- and heterochromatin. All applied techniques revealed that the euchromatin is located at the distal ends of all chromosome arms, besides the NOR-bearing ones. Interestingly, in addition one arm of chromosome 1 seems to be entirely euchromatic. Furthermore, we have analysed the correlation between the global distribution of histone H3 mono-, di- or trimethylated at either lysine 4, 9 or 27 and the microscopically detectable eu- and heterochromatin. Methylated H3K4 was found to be enriched exclusively within euchromatin. From the other tested methylation marks only H3K9me1, H3K9me2 and H3K27me1 showed, in addition to a more or less disperse labelling, an enrichment within the heterochromatic chromocentres. The cell cycle dependent phosphorylation of histone H3 at serine 10 and threonine 11 was enriched in all pericentromeric regions. PMID:19738383

  2. Phenotypic and RAPD diversity among 80 germplasm accessions of the medicinal plant isabgol (Plantago ovata, Plantaginaceae).

    PubMed

    Singh, N; Lal, R K; Shasany, A K

    2009-01-01

    Plantago ovata, popularly known as isabgol, has great commercial and medicinal importance due to thin rosy white membranous seed husk. Isabgol seeds and husks have emollient, demulcent and laxative properties. We used both biometric and molecular techniques to assess the genetic variability and relatedness of 80 germplasm accessions of Plantago spp (P. ovata, P. lanceolata, and P. major) collected both from India and abroad. The range of D2 values (2.01-4890.73) indicated a very high degree of divergence among the accessions. Based on the degree of divergence, 80 accessions/genotypes were grouped into seven clusters. Thirty-six accessions were analyzed through RAPD profiling for similarity and genetic distances, using 20 random primers. Intraspecific differences in all three species were smaller [range for P. ovata (2-17%), P. lanceolata (3-15%), P. major (2-11%)] than interspecific diversity. These highly divergent lines could be used to produce superior hybrids. PMID:19876869

  3. Ovatoxin-a, A Palytoxin Analogue Isolated from Ostreopsis cf. ovata Fukuyo: Cytotoxic Activity and ELISA Detection.

    PubMed

    Pelin, Marco; Forino, Martino; Brovedani, Valentina; Tartaglione, Luciana; Dell'Aversano, Carmela; Pistocchi, Rossella; Poli, Mark; Sosa, Silvio; Florio, Chiara; Ciminiello, Patrizia; Tubaro, Aurelia

    2016-02-01

    This study provides the first evaluation of the cytotoxic effects of the recently identified palytoxin (PLTX) analog, ovatoxin-a (OVTX-a), the major toxin produced by Ostreopsis cf. ovata in the Mediterranean Sea. Its increasing detection during Ostreopsis blooms and in seafood highlights the need to characterize its toxic effects and to set up appropriate detection methods. OVTX-a is about 100 fold less potent than PLTX in reducing HaCaT cells viability (EC50 = 1.1 × 10(-9) M vs 1.8 × 10(-11) M, MTT test) in agreement with a reduced binding affinity (Kd = 1.2 × 10(-9) vs 2.7 × 10(-11) M, saturation experiments on intact cells). Similarly, OVTX-a hemolytic effect is lower than that of the reference PLTX compound. Ost-D shows the lowest cytotoxicity toward HaCaT keratinocytes, suggesting the lack of a hydroxyl group at C44 as a critical feature for PLTXs cytotoxic effects. A sandwich ELISA developed for PLTX detects also OVTX-a in a sensitive (LOD = 4.2 and LOQ = 5.6 ng/mL) and accurate manner (Bias = 0.3%), also in O. cf. ovata extracts and contaminated mussels. Although in vitro OVTX-a appears less toxic than PLTX, its cytotoxicity at nanomolar concentrations after short exposure time rises some concern for human health. The sandwich ELISA can be a viable screening method for OVTXs detection in monitoring program. PMID:26714047

  4. Formulation of nutrient medium for in vitro somatic embryo induction in Plantago ovata forsk.

    PubMed

    Saha, Priyanka; Bandyopadhyay, Subhendu; Raychaudhuri, Sarmistha Sen

    2011-05-01

    A nutrient medium has been formulated by altering the macro- and micro-elemental concentration in the culture medium for in vitro somatic embryo induction of economically important medicinal plant Plantago ovata Forsk .A comparison was made between induced embryos with normal embryos (produced in Murashige and Skoog (MS) medium) to observe frequency of embryo induction and also to determine regeneration efficiency. In the present investigation, three different media have been formulated. Among them, FM3 (formulated media, treatment 3) was the most suitable for increasing the frequency of somatic embryo production and regeneration of P. ovata Forsk. Better result was obtained using formulated medium than with MS medium. PMID:20405339

  5. Biochemical and Genomic Characterization of Terpene Synthases in Magnolia grandiflora1[W][OA

    PubMed Central

    Lee, Sungbeom; Chappell, Joseph

    2008-01-01

    Magnolia grandiflora (Southern Magnolia) is a primitive evergreen tree that has attracted attention because of its horticultural distinctiveness, the wealth of natural products associated with it, and its evolutionary position as a basal angiosperm. Three cDNAs corresponding to terpene synthase (TPS) genes expressed in young leaves were isolated, and the corresponding enzymes were functionally characterized in vitro. Recombinant Mg25 converted farnesyl diphosphate (C15) predominantly to β-cubebene, while Mg17 converted geranyl diphosphate (C5) to α-terpineol. Efforts to functionally characterize Mg11 were unsuccessful. Transcript levels for all three genes were prominent in young leaf tissue and significantly elevated for Mg25 and Mg11 messenger RNAs in stamens. A putative amino-terminal signal peptide of Mg17 targeted the reporter green fluorescent protein to both chloroplasts and mitochondria when transiently expressed in epidermal cells of Nicotiana tabacum leaves. Phylogenetic analyses indicated that Mg25 and Mg11 belonged to the angiosperm sesquiterpene synthase subclass TPS-a, while Mg17 aligned more closely to the angiosperm monoterpene synthase subclass TPS-b. Unexpectedly, the intron-exon organizations for the three Magnolia TPS genes were different from one another and from other well-characterized TPS gene sets. The Mg17 gene consists of six introns arranged in a manner similar to many other angiosperm sesquiterpene synthases, but Mg11 contains only four introns, and Mg25 has only a single intron located near the 5′ terminus of the gene. Our results suggest that the structural diversity observed in the Magnolia TPS genes could have occurred either by a rapid loss of introns from a common ancestor TPS gene or by a gain of introns into an intron-deficient progenote TPS gene. PMID:18467455

  6. Anti-emetic principles of Magnolia obovata bark and Zingiber officinale rhizome.

    PubMed

    Kawai, T; Kinoshita, K; Koyama, K; Takahashi, K

    1994-02-01

    Magnolol and honokiol, biphenyl compounds, were isolated as anti-emetic principles from the methanolic extract of Magnolia obovata bark. [6]-, [8]-, and [10]-shogaols and [6]-, [8]-, and [10]-gingerols were isolated from the methanolic extract of Zingiber officinale rhizome as anti-emetic principles. Some phenyl-propanoids with allyl side-chains were found to show the same activity. They inhibited the emetic action induced by the oral administration of copper sulfate pentahydrate to leopard and ranid frogs. PMID:8134409

  7. Identification of Magnolia officinalis L. bark extract as the most potent anti-inflammatory of four plant extracts.

    PubMed

    Walker, Joel M; Maitra, Amarnath; Walker, Jessica; Ehrnhoefer-Ressler, Miriam M; Inui, Taichi; Somoza, Veronika

    2013-01-01

    This study was designed to compare the anti-inflammatory potential of a Magnolia officinalis L. bark extract solely or in combination with extracts prepared from either Polygonum aviculare L., Sambucus nigra L., or Isodon japonicus L. in bacterial lipopolysaccharide (LPS) stimulated human gingival fibroblasts (HGF-1) and human U-937 monocytes, as cell models of periodontal disease. HGF-1 and U-937 cells were incubated with LPS from either Porphyromonas gingivalis or Escherichia coli together with the four plant extracts alone or in combination. Secretion of anti-inflammatory cytokines from HGF-1 and U-937 cells was measured by means of a multiplexed bead assay system. Magnolia officinalis L. bark extract, at concentrations of 1 μg/mL and 10 μg/mL, reduced interleukin 6 (IL-6) and interleukin-8 (IL-8) secretion from HGF-1 cells to 72.5 ± 28.6% and reduced matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) secretion from U-937 cells to 8.87 ± 7.97% compared to LPS-treated cells (100%). The other three extracts also reduced secretion of these inflammatory markers but were not as effective. Combination of 9 μg/mL Magnolia officinalis L. extract with 1 μg/mL of each of the other extracts maintained the anti-inflammatory effect of Magnolia officinalis L. extract. Combination of 5 μg/mL Magnolia officinalis L. extract with 5 μg/mL Isodon japonicus L. extract also maintained the anti-inflammatory potential of the Magnolia officinalis L. extract, whereas increasing concentrations of any of the other plant extracts in the combination experiments reduced the Magnolia officinalis L. extract efficacy in U-937 cells. PMID:23711140

  8. De Novo Transcriptome Analysis of Medicinally Important Plantago ovata Using RNA-Seq

    PubMed Central

    Kotwal, Shivanjali; Kaul, Sanjana; Sharma, Pooja; Gupta, Mehak; Shankar, Rama; Jain, Mukesh; Dhar, Manoj K.

    2016-01-01

    Plantago ovata is an economically and medicinally important plant of the family Plantaginaceae. It is used extensively for the production of seed husk for its application in pharmaceutical, food and cosmetic industries. In the present study, the transcriptome of P. ovata ovary was sequenced using Illumina Genome Analyzer platform to characterize the mucilage biosynthesis pathway in the plant. De novo assembly was carried out using Oases followed by velvet. A total of 46,955 non-redundant transcripts (≥100 bp) using ~29 million high-quality paired end reads were generated. Functional categorization of these transcripts revealed the presence of several genes involved in various biological processes like metabolic pathways, mucilage biosynthesis, biosynthesis of secondary metabolites and antioxidants. In addition, simple sequence-repeat motifs, non-coding RNAs and transcription factors were also identified. Expression profiling of some genes involved in mucilage biosynthetic pathway was performed in different tissues of P. ovata using Real time PCR analysis. The study has resulted in a valuable resource for further studies on gene expression, genomics and functional genomics in P. ovata. PMID:26943165

  9. De Novo Transcriptome Analysis of Medicinally Important Plantago ovata Using RNA-Seq.

    PubMed

    Kotwal, Shivanjali; Kaul, Sanjana; Sharma, Pooja; Gupta, Mehak; Shankar, Rama; Jain, Mukesh; Dhar, Manoj K

    2016-01-01

    Plantago ovata is an economically and medicinally important plant of the family Plantaginaceae. It is used extensively for the production of seed husk for its application in pharmaceutical, food and cosmetic industries. In the present study, the transcriptome of P. ovata ovary was sequenced using Illumina Genome Analyzer platform to characterize the mucilage biosynthesis pathway in the plant. De novo assembly was carried out using Oases followed by velvet. A total of 46,955 non-redundant transcripts (≥100 bp) using ~29 million high-quality paired end reads were generated. Functional categorization of these transcripts revealed the presence of several genes involved in various biological processes like metabolic pathways, mucilage biosynthesis, biosynthesis of secondary metabolites and antioxidants. In addition, simple sequence-repeat motifs, non-coding RNAs and transcription factors were also identified. Expression profiling of some genes involved in mucilage biosynthetic pathway was performed in different tissues of P. ovata using Real time PCR analysis. The study has resulted in a valuable resource for further studies on gene expression, genomics and functional genomics in P. ovata. PMID:26943165

  10. Evaluation of the Association Metformin: Plantago ovata Husk in Diabetic Rabbits.

    PubMed

    Díez-Láiz, Raquel; García-Vieitez, Juan J; Diez-Liébana, M José; Sierra-Vega, Matilde; Sahagún-Prieto, Ana M; Calle-Pardo, Ángela P; Fernández-Martínez, Nélida

    2015-01-01

    In this experimental study we have investigated whether the inclusion of the dietary fiber Plantago ovata husk could be recommended as coadjuvant in treatments with oral hypoglycemic drugs. We evaluated the use of Plantago ovata husk-metformin association in diabetic rabbits by determining its effects on glucose and insulin concentrations. Six groups of 6 rabbits were used. Groups 1 to 3 were fed with standard chow and groups 4 to 6 with chow supplemented with Plantago ovata husk (3.5 mg/kg/day). Two groups (numbers 1 and 4) were used as controls (receiving standard or supplemented chow), two groups (numbers 2 and 5) received metformin orally, and the other two (numbers 3 and 6) were treated orally with metformin and psyllium. Plasma glucose concentrations were lower in groups fed with fiber-supplemented chow whereas insulin levels showed important interindividual variations. Glucose pharmacokinetics parameters showed significant differences in Cmax and t(max) in relation to fiber intake. Insulin pharmacokinetics parameters after treatment with oral metformin showed an important increase in Cmax, AUC, and t(max) in animals fed with fiber. We conclude that Plantago ovata husk intake can contribute to the oral antihyperglycemic treatment of type 2 diabetes. PMID:26576433

  11. Isolation, characterization and investigation of Plantago ovata husk polysaccharide as superdisintegrant.

    PubMed

    Pawar, Harshal; Varkhade, Chhaya

    2014-08-01

    Psyllium husk (Plantago ovata, Family: Plantaginaceae) contains a high proportion of hemicellulose, composed of a xylan backbone linked with arabinose, rhamnose, and galacturonic acid units (arabinoxylans). Polysaccharide was isolated from Psyllium husk using solvent precipitation method. The isolated polysaccharide was evaluated for various physicochemical parameters. The rheological behavior of polysaccharide (1% w/v in water) was studied using Brookfield viscometer. Polysaccharide derived from the husk of P. ovata was investigated as superdisintegrant in the fast dissolving tablets. Valsartan, an antihypertensive drug, was selected as a model drug. The tablets of Valsartan were prepared separately using different concentrations (1, 2.5, 5, 7.5% w/w) of isolated Plantago ovata (P. ovata) husk polysaccharide (Natural) and crospovidone as a synthetic superdisintegrant by direct compression method. The prepared tablets were evaluated for various pre-compression and post-compression parameters. The drug excipient interactions were characterized by FTIR studies. The formulation F4 containing7.5% polysaccharide showed rapid wetting time and disintegration time as compared to formulation prepared using synthetic superdisintegrant at the same concentration level. Hence batch F4 was considered as optimized formulation. The stability studies were performed on formulation F4. The disintegration time and in vitro drug release of the optimized formulation was compared with the marketed formulation (Conventional tablets). PMID:24854213

  12. Evaluation of the Association Metformin: Plantago ovata Husk in Diabetic Rabbits

    PubMed Central

    Díez-Láiz, Raquel; García-Vieitez, Juan J.; Diez-Liébana, M. José; Sierra-Vega, Matilde; Sahagún-Prieto, Ana M.; Calle-Pardo, Ángela P.; Fernández-Martínez, Nélida

    2015-01-01

    In this experimental study we have investigated whether the inclusion of the dietary fiber Plantago ovata husk could be recommended as coadjuvant in treatments with oral hypoglycemic drugs. We evaluated the use of Plantago ovata husk-metformin association in diabetic rabbits by determining its effects on glucose and insulin concentrations. Six groups of 6 rabbits were used. Groups 1 to 3 were fed with standard chow and groups 4 to 6 with chow supplemented with Plantago ovata husk (3.5 mg/kg/day). Two groups (numbers 1 and 4) were used as controls (receiving standard or supplemented chow), two groups (numbers 2 and 5) received metformin orally, and the other two (numbers 3 and 6) were treated orally with metformin and psyllium. Plasma glucose concentrations were lower in groups fed with fiber-supplemented chow whereas insulin levels showed important interindividual variations. Glucose pharmacokinetics parameters showed significant differences in Cmax and tmax in relation to fiber intake. Insulin pharmacokinetics parameters after treatment with oral metformin showed an important increase in Cmax, AUC, and tmax in animals fed with fiber. We conclude that Plantago ovata husk intake can contribute to the oral antihyperglycemic treatment of type 2 diabetes. PMID:26576433

  13. The role of ABC genes in shaping perianth phenotype in the basal angiosperm Magnolia.

    PubMed

    Wróblewska, M; Dołzbłasz, A; Zagórska-Marek, B

    2016-03-01

    It is generally accepted that the genus Magnolia is characterised by an undifferentiated perianth, typically organised into three whorls of nearly identical tepals. In some species, however, we encountered interesting and significant perianth modifications. In Magnolia acuminata, M. liliiflora and M. stellata the perianth elements of the first whorl are visually different from the others. In M. stellata the additional, spirally arranged perianth elements are present above the first three whorls, which suggests that they have been formed within the domain of stamen primordia. In these three species, we analysed expression patterns of the key flower genes (AP1, AGL6, AP3, PI, AG) responsible for the identity of flower elements and correlated them with results of morphological and anatomical investigations. In all studied species the elements of the first whorl lacked the identity of petals (lack of AP3 and PI expression) but also that of leaves (presence of AGL6 expression), and this seems to prove their sepal character. The analysis of additional perianth elements of M. stellata, spirally arranged on the elongated floral axis, revealed overlapping and reduced activity of genes involved in specification of the identity of the perianth (AGL6) but also of generative parts (AG), even though no clear gradient of morphological changes could be observed. In conclusion, Magnolia genus is capable of forming, in some species, a perianth differentiated into a calyx (sepals) and corolla (petals). Spirally arranged, additional perianth elements of M. stellata, despite activity of AG falling basipetally, resemble petals. PMID:26359638

  14. Comparative analysis of essential oil composition from flower and leaf of Magnolia kwangsiensis Figlar & Noot.

    PubMed

    Zheng, Yan-Fei; Ren, Fan; Liu, Xiong-Min; Lai, Fang; Ma, Li

    2016-07-01

    The essential oils from Magnolia kwangsiensis Figlar & Noot. were obtained using hydrodistillation, and analysed by GC and GC-MS. A total of 31, 27 and 26 constituents were identified in the oils from male flower, female flower and leaf of M. kwangsiensis, and they comprised 99.2, 98.5 and 96.2% of the oils, respectively. Monoterpene hydrocarbons predominated in the oils and accounted for 48.3% of male flower oil, 54.0% of female flower oil and 44.6% of leaf oil. The compositions of flower oils were quite similar but with different content, and were different from those of leaf oil. PMID:26652973

  15. In vitro radiation induced alterations in heavy metals and metallothionein content in Plantago ovata Forsk.

    PubMed

    Saha, Priyanka; Mishra, Debadutta; Chakraborty, Anindita; Sudarshan, Mathummal; Raychaudhuri, Sarmistha Sen

    2008-09-01

    Proton Induced X-ray emission (PIXE) and fluorescence-activated cell sorting (FACS) have been used to study the effects of gamma irradiation on heavy metal accumulation in callus tissue of Plantago ovata-an important cash crop of India. PIXE analysis revealed radiation-induced alteration in trace element profile during developmental stages of the callus of P. ovata. Subsequent experiments showed antagonism between Fe and Cu and also Cu and Zn and synergistic effect between Fe and Zn. FACS analysis showed significant induction of the metallothionein (MT) protein following gamma-irradiation, and maximum induction was noted at the 50-Gy absorbed dose. This indicated a progressive increment of MTs as a measure for protection against gamma-rays, to combat alteration in the homeostasis of heavy metals like Fe, Cu, Zn, and Mn. PMID:18493724

  16. PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk.

    PubMed

    Saha, Priyanka; Raychaudhuri, Sarmistha Sen; Chakraborty, Anindita; Sudarshan, Mathummal

    2010-03-01

    Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations. PMID:20047839

  17. Contribution of trehalose biosynthetic pathway to drought stress tolerance of Capparis ovata Desf.

    PubMed

    Ilhan, S; Ozdemir, F; Bor, M

    2015-03-01

    Trehalose and the trehalose biosynthetic pathway are important contributors and regulators of stress responses in plants. Among recent findings for trehalose and its metabolism, the role of signalling in the regulation of growth and development and its potential for use as a storage energy source can be listed. The xerophytic plant Capparis ovata (caper) is well adapted to drought and high temperature stress in arid and semi-arid regions of the Mediterranean. The contribution of trehalose and the trehalose biosynthetic pathway to drought stress responses and tolerance in C. ovata are not known. We investigated the effects of PEG-mediated drought stress in caper plants and analysed physiological parameters and trehalose biosynthetic pathway components, trehalose-6-phosphate synthase (TPS), trehalose-6-phosphate phosphatase (TPP), trehalase activity, trehalose and proline content in drought stress-treated and untreated plants. Our results indicated that trehalose and the trehalose biosynthetic pathway contributed to drought stress tolerance of C. ovata. Overall growth and leaf water status were not dramatically affected by drought, as both high relative growth rate and relative water content were recorded even after 14 days of drought stress. Trehalose accumulation increased in parallel to induced TPS and TPP activities and decreased trehalase activity in caper plants on day 14. Constitutive trehalose levels were 28.75 to 74.75 μg·g·FW(-1) , and drought stress significantly induced trehalose accumulation (385.25 μg·g·FW(-1) on day 14) in leaves of caper. On day 14 of drought, proline levels were lower than on day 7. Under drought stress the discrepancy between trehalose and proline accumulation trends might result from the mode of action of these osmoprotectant molecules in C. ovata. PMID:25294040

  18. New Insights on Cytological and Metabolic Features of Ostreopsis cf. ovata Fukuyo (Dinophyceae): A Multidisciplinary Approach

    PubMed Central

    Honsell, Giorgio; Bonifacio, Alois; De Bortoli, Marco; Penna, Antonella; Battocchi, Cecilia; Ciminiello, Patrizia; Dell’Aversano, Carmela; Fattorusso, Ernesto; Sosa, Silvio; Yasumoto, Takeshi; Tubaro, Aurelia

    2013-01-01

    The harmful dinoflagellate Ostreopsis cf. ovata has been causing toxic events along the Mediterranean coasts and other temperate and tropical areas, with increasing frequency during the last decade. Despite many studies, important biological features of this species are still poorly known. An integrated study, using different microscopy and molecular techniques, Raman microspectroscopy and high resolution liquid chromatography-mass spectrometry (HR LC-MS), was undertaken to elucidate cytological aspects, and identify main metabolites including toxins. The species was genetically identified as O. cf. ovata, Atlantic-Mediterranean clade. The ultrastructural results show unique features of the mucilage network abundantly produced by this species to colonize benthic substrates, with a new role of trichocysts, never described before. The amorphous polysaccharidic component of mucilage appears to derive from pusule fibrous material and mucocysts. In all stages of growth, the cells show an abundant production of lipids. Different developmental stages of chloroplasts are found in the peripheral cytoplasm and in the centre of cell. In vivo Raman microspectroscopy confirms the presence of the carotenoid peridinin in O. cf. ovata, and detects in several specimen the abundant presence of unsaturated lipids structurally related to docosahexaenoic acid. The HR LC-MS analysis reveals that ovatoxin-a is the predominant toxin, together with decreasing amounts of ovatoxin-b, -d/e, -c and putative palytoxin. Toxins concentration on a per cell basis increases from exponential to senescent phase. The results suggest that benthic blooms of this species are probably related to features such as the ability to create a unique mucilaginous sheath covering the sea bottom, associated with the production of potent toxins as palytoxin-like compounds. In this way, O. cf. ovata may be able to rapidly colonize benthic substrates outcompeting other species. PMID:23460837

  19. Inhibition of melanogenesis and antioxidant properties of Magnolia grandiflora L. flower extract

    PubMed Central

    2012-01-01

    Background Magnolia grandiflora L. flower is wildly used in Asian as a traditional herbal medication. The purpose of the study was to investigate the antimelanogenic and antioxidant properties of Magnolia grandiflora L. flower extract. In the study, the inhibitory effects of M. grandiflora L. flower extract on mushroom tyrosinase, B16F10 intracellular tyrosinase activity and melanin content were determined spectrophotometrically. Meanwhile, the antioxidative capacity of the flower extract was also investigated. Results Our results revealed that M. grandiflora L. flower extract inhibit mushroom tyrosinase activity (IC50 =11.1%; v/v), the flower extract also effectively suppressed intracellular tyrosinase activity (IC50 = 13.6%; v/v) and decreased the amount of melanin (IC50 = 25.6%; v/v) in a dose-dependent manner in B16F10 cells. Protein expression level of tyrosinase and tyrosinase-related protein 1 (TRP-1) were also decreased by the flower extract. Additionally, antioxidant capacities such as ABTS+ free radical scavenging activity, reducing capacity and total phenolic content of the flower extract were increased in a dose-dependent pattern. Conclusions Our results concluded that M. grandiflora L. flower extract decreased the expression of tyrosinase and TRP-1, and then inhibited melanogenesis in B16F10 cells. The flower extract also show antioxidant capacities and depleted cellular reactive oxygen species (ROS). Hence, M. grandiflora L. flower extract could be applied as a type of dermatological whitening agent in skin care products. PMID:22672352

  20. Cloning, prokaryotic expression and functional analysis of squalene synthase (SQS) in Magnolia officinalis.

    PubMed

    Zha, Liangping; Liu, Shuang; Su, Ping; Yuan, Yuan; Huang, Luqi

    2016-04-01

    Magnolia officinalis Rehder et Wilson is a traditional Chinese herbal medicine that is used to treat various diseases such as neurosis, anxiety, and stroke. The main secondary metabolites in magnolia bark are phenolic compounds and terpenoids. Squalene synthase plays a significant role in catalyzing two farnesyl diphosphate molecules to form squalene, the first precursor of triterpenoid, phytosterol, and cholesterol biosynthesis. In this study, a full-length cDNA of squalene synthase was cloned from M. officinalis and designated MoSQS (GenBank accession no. KT223496). The gene contains a 1240-bp open reading frame and it encodes a protein with 409 amino acids. Bioinformatic and phylogenetic analysis clearly suggested that MoSQS shared high similarity with squalene synthases among other plants. Prokaryotic expression showed that a transmembrane domain-deleted (385-409 aa) MoSQS mutant (MoSQSΔTM) could be expressed in its soluble form in Escherichia coli Transetta (DE3). GC-MS analysis showed that squalene was detected in an in vitro reaction mixture. These results indicated that MoSQSΔTM was functional, thereby establishing an important foundation for the study of triterpenoid biosynthesis in M. officinalis. PMID:26696600

  1. Chemistry and bioactivity of Flos Magnoliae, a Chinese herb for rhinitis and sinusitis.

    PubMed

    Shen, Y; Li, C G; Zhou, S F; Pang, E C K; Story, D F; Xue, C C L

    2008-01-01

    Flos Magnoliae (FM, Chinese name: Xin-yi) is one of the most commonly used Chinese medicinal herbs. It has a long history of clinical use for managing rhinitis, sinusitis and headache. More than 20 different FM species have been used clinically, which makes species identification and evaluation of pharmacological effects of individual chemical ingredients difficult. In this review, we have summarized the current knowledge on FM phytochemistry and its bioactivity activities. The bioactive compounds in FM include both lipid and water-soluble components. More than 90% of the essential components of FM species are terpenoids, including monoterpenes and sesquiterpenes. Lignans and neolignans including tetrahydrofurofuran, tetrahydrofuran and aryltetralin are also present in FM species. A small number of water-soluble compounds have been isolated from Magnolia flower buds, including a benzylisoquinoline alkaloid magnoflorine, an ester ethyl-E-p-hydroxyl-cinnamate and a flavonoid biondnoid. A wide range of pharmacological actions of FM have been reported, including anti-allergy, anti-inflammation and anti-microbial activity. The structure-activity relationship analysis revealed the influence of methylation at position 5 on the 3,7-dioxabicyclo-(3,3,0)-octane backbone of six lignans in antagonistic activities against platelet-activating factor. In addition, the trans stereoisomer fargesin had a much lower bioactivity than the cis stereoisomer demethoxyaschantin. Recent studies have been directed towards the isolation of other bioactive compounds. Further studies on FM may help to develop new anti-inflammatory and anti-allergic drugs. PMID:18673228

  2. Species diversity, structure and dynamics of two populations of an endangered species, Magnolia dealbata (Magnoliaceae).

    PubMed

    Sánchez-Velásquez, Lázaro R; Pineda-López, María del Rosario

    2006-09-01

    Little is known about the ecology and demography of the genus Magnolia. Magnolia dealbata Zucc. is an endangered species endemic to Mexico. Two contrasting populations of M. dealbata (one from the grasslands and other from a secondary cloud forest) were studied. We asked the following questions: (a) Are size structure (diameter at breast height, DBH) and infrutescence production significantly different between the two populations? (b) What are the populations' growth rates (lambda) based on an initial 1987 study? (c) Are the associated species diversity indices of these M. dealbata populations significantly different? The results show no significant differences between the population size structure (p=.094); the growth rates of the populations were 0.992 in grassland and 1.053 in secondary cloud forest. The number of infrutescences produced in year 2001 and DBH relationship were significantly linear (p<.001) in both populations, and there was no significant difference (p>.01) between their slopes. The diversity indices were not significantly different (p>.05), and only 54% of the species were common to both sites. Our study suggests that both populations are relatively stable and that the management history could impact more on the species composition than on the diversity indices. PMID:18494171

  3. Quantitative histopathology of the Mediterranean mussel (Mytilus galloprovincialis L.) exposed to the harmful dinoflagellate Ostreopsis cf. ovata.

    PubMed

    Carella, F; Sardo, A; Mangoni, O; Di Cioccio, D; Urciuolo, G; De Vico, G; Zingone, A

    2015-05-01

    Ostreopsis cf. ovata is a benthic dinoflagellate that produces palytoxin-like compounds that adversely affect both marine vertebrates and invertebrates and are reported to be responsible for human intoxication in aerosol form. In this work, a histopathological analysis accompanied by quantitative evaluation of tissue injury in mussels (Mytilus galloprovincialis) exposed to O. cf. ovata cells under natural and experimental conditions, provided baseline data on the health status of the mussels in terms of defensive and regressive pathological changes. We recorded a total of 15 health parameters in the digestive system, muscle, kidney and gills in mussels exposed to O. cf. ovata both in the laboratory and at sea. Animals exposed to different concentrations of O. cf. ovata cells (300, 500 and 1000cellsml(-)(1)) for 48h showed activation of the inflammatory response, which increased with the cell concentration, mainly characterized by haemocyte aggregates actively enclosing the algae, while mussel mortality was also recorded in some cases. Moreover the use of image analysis for the evaluation of digestive tubule damage revealed a pronounced increase in the lumen in terms of its area, perimeter and circularity, with a shift in a high percentage of tubules from an adsorbing profile to an atrophic profile. Animals collected from the natural environment during a summer bloom of O. cf. ovata in the Gulf of Naples (Italy) showed comparable lesions in terms of types and severity. This is the first quantitative study assessing damage to the digestive epithelia in terms of lumen modifications in mussels exposed to O. cf. ovata. The presented methodology provides a new technique for automating the evaluation of epithelial tubule modifications. Our results highlight the importance of monitoring the presence of O. cf. ovata in this area, taking into account the effects on the residing marine species. PMID:25769513

  4. Molecular and structural characteristics in toxic algae cultures of Ostreopsis ovata and Ostreopsis spp. evidenced by FTIR and FTNIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Mecozzi, Mauro; Pietroletti, Marco; Tornambè, Andrea

    2011-05-01

    In this article we investigated the compositional and structural characteristics of the principal biomolecules such as carbohydrates, proteins, lipids, nucleic acids and chlorophyll pigments present in biofilm cultures of Ostreopsis spp. and in batch cultures of Ostreopsis ovata. Our approach based on the use of infrared (FTIR) and near infrared (FTNIR) spectroscopy showed the marked differences existing between biofilm cultures and batch cultures. FTIR spectroscopy showed the higher contents of polysaccharides and chlorophyll pigments in O. ovata from batch cultures with respect to Ostreopsis spp. Second derivative FTIR spectroscopy showed different features concerning the secondary structure of proteins because in O. ovata samples the beta sheet and beta turn structures were observed whereas in Ostreopsis spp. samples the alpha helix structure was the most evident. FTNIR spectroscopy showed other structural differences observed existing between O. ovata and Ostreopsis spp. mainly related to hydrogen bond interactions determining more packed structures in the nucleus of O. ovata. In addition, the interpretation of FTIR and FTNIR spectral information was also supported by the application of two statistical methods, the independent component analysis (ICA) and the spectral cross correlation analysis (SCCA). ICA was used as spectral deconvolution technique to separate the effects of the interference bicarbonate ion from algal FTIR spectra so to verify the high similar qualitative composition of the three biofilm samples of Ostreopsis spp. At last, SCCA applied to FTIR and FTNIR spectra was useful to evidence some structural differences involving -CH and CH 2 groups of aliphatic chains in O. ovata and Ostreopsis spp. samples. Though preliminary, these results agree with some previous studies suggesting that the presence of different ecophysiological characteristics in O. ovata and Ostreopsis spp. depending on the parameters related to the condition growth.

  5. Magnolia officinalis Extract Contains Potent Inhibitors against PTP1B and Attenuates Hyperglycemia in db/db Mice.

    PubMed

    Sun, Jing; Wang, Yongsen; Fu, Xueqi; Chen, Yingli; Wang, Deli; Li, Wannan; Xing, Shu; Li, Guodong

    2015-01-01

    Protein tyrosine phosphatase 1B (PTP1B) is an established therapeutic target for type 2 diabetes mellitus (T2DM) and obesity. The aim of this study was to investigate the inhibitory activity of Magnolia officinalis extract (ME) on PTP1B and its anti-T2DM effects. Inhibition assays and inhibition kinetics of ME were performed in vitro. 3T3-L1 adipocytes and C2C12 myotubes were stimulated with ME to explore its bioavailability in cell level. The in vivo studies were performed on db/db mice to probe its anti-T2DM effects. In the present study, ME inhibited PTP1B in a reversible competitive manner and displayed good selectivity against PTPs in vitro. Furthermore, ME enhanced tyrosine phosphorylation levels of cellular proteins, especially the insulin-induced tyrosine phosphorylations of insulin receptor β-subunit (IRβ) and ERK1/2 in a dose-dependent manner in stimulated 3T3-L1 adipocytes and C2C12 myotubes. Meanwhile, ME enhanced insulin-stimulated GLUT4 translocation. More importantly, there was a significant decrease in fasting plasma glucose level of db/db diabetic mice treated orally with 0.5 g/kg ME for 4 weeks. These findings indicated that improvement of insulin sensitivity and hypoglycemic effects of ME may be attributed to the inhibition of PTP1B. Thereby, we pioneered the inhibitory potential of ME targeted on PTP1B as anti-T2DM drug discovery. PMID:26064877

  6. Striking differences in RNA editing requirements to express the rps4 gene in magnolia and sunflower mitochondria.

    PubMed

    Regina, Teresa M R; Lopez, Loredana; Picardi, Ernesto; Quagliariello, Carla

    2002-03-01

    The ribosomal protein S4 gene (rps4) has been identified as a single copy sequence in the mitochondrial genomes of two distant higher plants, Magnolia and Helianthus. Sequence analysis revealed that the rps4 genes present in the magnolia and sunflower mitochondrial genomes encode S4 polypeptides of 352 and 331 amino acids, respectively, longer than their counterparts in liverwort and bacteria. Expression of the rps4 genes in the investigated higher plant mitochondria was confirmed by Western blot analysis. In Helianthus, one of two short nucleotide insertions at the 3'-end introduces in the coding region a premature termination codon. Northern hybridizations and reverse transcription-polymerase chain reaction analysis demonstrated that the monocistronic RNA transcripts generated from the rps4 locus in Magnolia and Helianthus mitochondria are modified by RNA editing at 28 and 13 positions, respectively. Although evolutionarily conserved, RNA editing requirements of the rps4 appear more extensive in Magnolia than in Helianthus and in the other higher plants so far investigated. Furthermore, our analysis also suggests that selection of editing sites is RNA sequence-specific in a duplicated sequence context. PMID:11943458

  7. Biological effects of palytoxin-like compounds from Ostreopsis cf. ovata: a multibiomarkers approach with mussels Mytilus galloprovincialis.

    PubMed

    Gorbi, S; Bocchetti, R; Binelli, A; Bacchiocchi, S; Orletti, R; Nanetti, L; Raffaelli, F; Vignini, A; Accoroni, S; Totti, C; Regoli, F

    2012-10-01

    Massive blooms of the harmful benthic dinoflagellate Ostreopsis cf. ovata are of growing environmental concern in the Mediterranean, having recently caused adverse effects on benthic invertebrates and also some intoxication episodes to humans. The toxicological potential of produced palytoxin-like compounds was investigated in the present study on a typical marine sentinel species, the mussel Mytilus galloprovincialis. Organisms were sampled during various phases of a O. cf. ovata bloom, in two differently impacted sites. The presence of the algal toxins was indirectly assessed in mussels tissues (mouse test and hemolysis neutralization assay), while biological and toxicological effects were evaluated through the measurement of osmoregulatory and neurotoxic alterations (Na(+)/K(+)-ATPase and acetylcholinesterase activities), oxidative stress responses (antioxidant defences and total oxyradical scavenging capacity), lipid peroxidation processes (level of malondialdehyde), peroxisomal proliferation, organelle dysfunctions (lysosomal membrane stability, accumulation of lipofuscin and neutral lipids), immunological impairment (granulocytes percentage). Obtained results demonstrated a significant accumulation of algal toxins in mussels exposed to O. cf. ovata. These organisms exhibited a marked inhibition of the Na(+)/K(+)-ATPase activity and alterations of immunological, lysosomal and neurotoxic responses. Markers of oxidative stress showed more limited variations suggesting that toxicity of the O. cf. ovata toxins is not primarily mediated by an over production of reactive oxygen species. This study provided preliminary results on the usefulness of a multi-biomarker approach to assess biological alterations and toxicological events associated to blooms of O. cf. ovata in marine organisms. PMID:22704213

  8. Polyethylene glycol-based ultrasound-assisted extraction of magnolol and honokiol from Cortex Magnoliae Officinalis.

    PubMed

    He, Lei; Fan, Tao; Hu, Jianguo; Zhang, Lijin

    2015-01-01

    In this study, a kind of green solvent named polyethylene glycol (PEG) was developed for the ultrasound-assisted extraction (UAE) of magnolol and honokiol from Cortex Magnoliae Officinalis. The effects of PEG molecular weight, PEG concentration, sample size, pH, ultrasonic power and extraction time on the extraction of magnolol and honokiol were investigated to optimise the extraction conditions. Under the optimal extraction conditions, the PEG-based UAE supplied higher extraction efficiencies of magnolol and honokiol than the ethanol-based UAE and traditional ethanol-reflux extraction. Furthermore, the correlation coefficient (R(2)), repeatability (relative standard deviation, n = 6) and recovery confirmed the validation of the proposed extraction method, which were 0.9993-0.9996, 3.1-4.6% and 92.3-106.8%, respectively. PMID:25204856

  9. Complex Toxin Profile of French Mediterranean Ostreopsis cf. ovata Strains, Seafood Accumulation and Ovatoxins Prepurification

    PubMed Central

    Brissard, Charline; Herrenknecht, Christine; Séchet, Véronique; Hervé, Fabienne; Pisapia, Francesco; Harcouet, Jocelyn; Lémée, Rodolphe; Chomérat, Nicolas; Hess, Philipp; Amzil, Zouher

    2014-01-01

    Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins have hemolytic properties. An average of 223 μg·kg−1 of palytoxin equivalent of whole flesh was found, thus exceeding the threshold of 30 μg·kg−1 in shellfish recommended by the European Food Safety Authority (EFSA). Ostreopsis cells showed the same toxin profile both in situ and in laboratory culture, with ovatoxin-a (OVTX-a) being the most abundant analogue (~50%), followed by OVTX-b (~15%), p-PLTX (12%), OVTX-d (8%), OVTX-c (5%) and OVTX-e (4%). Ostreopsis cf. ovata produced up to 2 g of biomass per L of culture, with a maximum concentration of 300 pg PLTX equivalent cell−1. Thus, an approximate amount of 10 mg of PLTX-group toxins may be produced with 10 L of this strain. Toxin extracts obtained from collected biomass were purified using different techniques such as liquid-liquid partition or size exclusion. Among these methods, open-column chromatography with Sephadex LH20 phase yielded the best results with a cleanup efficiency of 93% and recovery of about 85%, representing an increase of toxin percentage by 13 fold. Hence, this purification step should be incorporated into future isolation exercises. PMID:24828292

  10. Effects of Plantago ovata husk on levodopa (with Carbidopa) bioavailability in rabbits with autonomic gastrointestinal disorders.

    PubMed

    García, Juan J; Fernández, Nélida; Calle, Angela P; Diez, M José; Sahagún, Ana; Sierra, Matilde

    2009-07-01

    Gastrointestinal dysfunction is common in Parkinson's disease. Fiber therapy could be used to reduce the symptoms of gastrointestinal motility disorders. In a previous study, we showed that slowed gastrointestinal motility modified levodopa pharmacokinetics: area under the plasma concentration-time curve (AUC) and maximum plasma concentration (C(max)) decreased and the elimination was delayed. In this study, we evaluated whether or not the hydrosoluble fiber Plantago ovata husk is useful in improving levodopa pharmacokinetics in rabbits with autonomic gastrointestinal disorders induced by the administration of the anticholinergic biperiden. Levodopa + carbidopa (20:5 mg/kg), biperiden (100 microg/kg), and P. ovata husk (at two different doses: 100 and 400 mg/kg) were administered orally to rabbits for two periods of time (7 or 14 days). In all groups of animals, the AUC values were approximately 50% higher on the final day of treatment than on day 1. C(max) was also higher, with the greater increase at the 400 mg/kg dose of fiber, which resulted in a boost of approximately 35%. On day 1 of treatment and with both doses of fiber, AUC values were very similar to those obtained in previous work in rabbits with normal gastrointestinal motility, but the C(max) was lower. However, after 7 or 14 days, the AUC values were higher, but C(max) remained lower. The greatest differences were observed in plasma concentration before drug administration (C(min)), for which the highest increase was obtained with the dose of 400 mg/kg fiber on day 14 of treatment (349.8%). P. ovata husk could be beneficial in patients with Parkinson's disease because it regulates stool transit in the intestine and because it improves levodopa pharmacokinetics when gastrointestinal peristalsis is slowed. These changes could lead to a possible delay in the onset of dyskinesias and to changes in prognosis. PMID:19389862

  11. Chemical constituents from Sonneratia ovata Backer and their in vitro cytotoxicity and acetylcholinesterase inhibitory activities.

    PubMed

    Nguyen, Thi-Hoai-Thu; Pham, Huu-Viet-Thong; Pham, Nguyen-Kim-Tuyen; Quach, Ngo-Diem-Phuong; Pudhom, Khanitha; Hansen, Poul Erik; Nguyen, Kim-Phi-Phung

    2015-06-01

    Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-β-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata. Their chemical structures were established by spectroscopic data, as well as high resolution mass spectra and comparison with literature data. The in vitro acetylcholinesterase (AChE) inhibition and cytotoxic activities against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), MCF-7 (human breast cancer) cancer cell lines and PHF (primary human fibroblast) cell were evaluated on some extracts and purified compounds at a concentration of 100 μg/mL. Compounds (5, 6, 23) exhibited cytotoxicity against the MCF-7 cell line with the IC50 values of 146.9±9.0, 114.5±7.2, and 112.8±9.4 μM, respectively, while they showed nontoxic with the normal cell (PHF) with IC50s >277 μM. Among 15 tested compounds, (S)-rhodolatouchol (22) showed inhibition against AChE with an IC50 value of 96.1±14.5 μM. PMID:25933595

  12. [New settlers comb jellies Mnemiopsis leidyi (A. Agassiz) and Beroe ovata Mayer 1912 and their influence on the pelagic ecosystem of the northeastern part of the Black Sea].

    PubMed

    Shiganova, T A; Musaeva, E I; Bulgakova, Iu V; Mirzoian, Z A; MartynIuk, M L

    2003-01-01

    We analyzed the condition of pelagic ecosystem of northeastern Black Sea influenced by expansion of a new settler Beroe ovata in 1999-2001. Expansion of B. ovata considerably decreased the population of another new settler Mnemiopsis leidyi that deformed the Black Sea ecosystem for over a decade. Reduction of M. leidyi population limited its influence on the ecosystem and, consequently, we observed reestablishment of the main components of the Black Sea pelagic ecosystem--zooplankton and fish, their spawn and larvae. The relationship between annual and seasonal variability of the population and biomass of the both new settlers M. leidyi and B. ovata are discussed. PMID:12712584

  13. The protective effect of Capparis ovata on 6-mercaptopurine-induced hepatotoxicity and oxidative stress in rats.

    PubMed

    Tülümen, Tuğçe; Ayata, Ali; Özen, Metehan; Sütçü, Recep; Canatan, Duran

    2015-05-01

    Capparis ovata is a member of Capparidacaeae family has been used in phytomedicine with a lot of positive effects such as an antioxidative, antihyperlipidemic, anti-inflammatory, and antihepatotoxic agent. The aim of this study was to research the protective effect of C. ovata on 6-mercaptopurine (6-MP) induced to hepatotoxicity and oxidative stress in rats. The rats were divided into 4 groups: control, 6-MP, C. ovataovate, and 6-MP + C. ovata. A complete blood count was performed, liver function test and antioxidant enzymes levels such as superoxide dismutase, glutathione peroxidase, catalase, and malondialdehyde were measured in blood before and after a 14-day test period. White blood cell and platelet counts were lower in the 6-MP group than other 3 groups (P < 0.005). Hepatic transaminase levels were higher in 6-MP group than the 3 groups (P < 0.05). Superoxide dismutase, glutathione peroxidase, and CAT levels were lower and malondialdehyde was higher in blood samples in 6-MP group than other 3 groups (P < 0.005). In conclusion, our tests were showed that C. ovata may be useful in patients receiving 6-MP therapy to prevent hepatotoxicity and in order to maintain uninterrupted therapy possibly reducing the risk of relapse. Although additional studies ensure that Capparis does not affect 6-MP antileukemic activity. We believe these results are important contribution to the literature. PMID:25411867

  14. The hydrosoluble fiber Plantago ovata husk improves levodopa (with carbidopa) bioavailability after repeated administration.

    PubMed

    Diez, M Jose; Garcia, Juan J; Prieto, Carlos; Fernandez, Nelida; Sahagun, Ana; Sierra, Matilde

    2008-08-15

    The influence of treatment duration (7 or 14 days) with Plantago ovata husk/levodopa/carbidopa in the bioavailability and other pharmacokinetic parameters of levodopa were evaluated in rabbits. Fiber was administered at two different doses, 100 and 400 mg/kg, and the dosage of levodopa/carbidopa was 20:5 mg/kg. These doses were administered once a day. When 100 mg/kg of fiber was administered, the mean AUC value obtained for levodopa increased 20.2% from day 1 to day 7, and 27.2% from day 1 to day 14; C(max) was 8.6% higher on day 7 and 11.7% higher on day 14. When administering 400 mg/kg of fiber, the increase in AUC values was 17.6% on day 7 and 24.9% on day 14, and that of C(max) 11.1% on day 7 and 11.3% on day 14. The concentration determined immediately before drug administration (C(min)) increased progressively with the duration of treatment, and the highest increase (53.2%) was observed on day 14 with 100 mg/kg of fiber. There was also a delay in levodopa elimination (higher MRT and lower Cl) in a fiber-dose dependent manner. In summary, we found that there was an improvement in the extent of levodopa absorbed with higher final concentrations and that levodopa elimination was slower with the administration of P. ovata husk. PMID:18474374

  15. Bacterial communities associated with the ctenophores Mnemiopsis leidyi and Beroe ovata.

    PubMed

    Daniels, Camille; Breitbart, Mya

    2012-10-01

    Residing in a phylum of their own, ctenophores are gelatinous zooplankton that drift through the ocean's water column. Although ctenophores are known to be parasitized by a variety of eukaryotes, no studies have examined their bacterial associates. This study describes the bacterial communities associated with the lobate ctenophore Mnemiopsis leidyi and its natural predator Beroe ovata in Tampa Bay, Florida, USA. Investigations using terminal restriction fragment length polymorphism (T-RFLP) and cloning and sequencing of 16S rRNA genes demonstrated that ctenophore bacterial communities were distinct from the surrounding water. In addition, each ctenophore genus contained a unique microbiota. Ctenophore samples contained fewer bacterial operational taxonomic units (OTUs) by T-RFLP and lower diversity communities by 16S rRNA gene sequencing than the water column. Both ctenophore genera contained sequences related to bacteria previously described in marine invertebrates, and sequences similar to a sea anemone pathogen were abundant in B. ovata. Temporal sampling revealed that the ctenophore-associated bacterial communities varied over time, with no single OTU detected at all time points. This is the first report of distinct and dynamic bacterial communities associated with ctenophores, suggesting that these microbial consortia may play important roles in ctenophore ecology. Future work needs to elucidate the functional roles and mode of acquisition of these bacteria. PMID:22571334

  16. A review on the effects of environmental conditions on growth and toxin production of Ostreopsis ovata.

    PubMed

    Pistocchi, R; Pezzolesi, L; Guerrini, F; Vanucci, S; Dell'aversano, C; Fattorusso, E

    2011-03-01

    Since the end of the 1990s the occurrence of blooms of the benthic dinoflagellates Ostreopsis spp. is spreading in many tropical and temperate regions worldwide, sometimes causing benthonic biocenosis suffering and occasional human distress. Ostreopsis ovata has been found to produce palytoxin-like compounds, a class of highly potent toxins. As general, the highest abundances of Ostreopsis spp. are recorded during warmer periods characterized by high temperature, salinity, and water column stability. Moreover, as these cells are easily resuspended in the water column, the role of hydrodynamism in the blooms development and decline has been highlighted. The environmental conditions appear, therefore, to be one of the main factors determining the proliferation of these species as testified by several field surveys. Laboratory studies on the effect of environmental parameters on growth and toxicity of O. ovata are rather scarce. With regard to the effects of temperature, culture results indicate that different strains blooming along Italian coasts displayed different optima, in accordance to blooming periods, and that higher toxin levels correlated with best growth conditions. Additionally, in relation to an Adriatic strain, cell growth positively correlated with the increase in salinity, while toxicity was lowest at the highest salinity value (i.e. 40). For the same strain, both nitrogen and phosphorus limitation determined a decrease in cell toxicity showing different behaviour with respect to many other toxic dinoflagellates. PMID:20920514

  17. Comparative growth and toxin profile of cultured Ostreopsis ovata from the Tyrrhenian and Adriatic Seas.

    PubMed

    Guerrini, Franca; Pezzolesi, Laura; Feller, Andrea; Riccardi, Manuela; Ciminiello, Patrizia; Dell'Aversano, Carmela; Tartaglione, Luciana; Dello Iacovo, Emma; Fattorusso, Ernesto; Forino, Martino; Pistocchi, Rossella

    2010-01-01

    Massive blooms of the benthic dinoflagellate Ostreopsis ovata Fukuyo have recently occurred along the whole Italian coastlines, both Tyrrhenian and Adriatic, resulting sometimes in benthonic biocenosis sufferings and, occasionally, in human health problems. In this work, two strains of O. ovata collected in 2006 along the Adriatic and Tyrrhenian coastlines and grown in culture were studied to characterize their growth and toxin profile. The two strains showed different cell volumes, the Adriatic strain being nearly twice bigger than the Tyrrhenian, but they had similar slow growth rates. Liquid chromatography-mass spectrometry (LC-MS) analyses indicated that both strains produce putative palytoxin (pPLTX) and ovatoxin-a (OVTX-a), a palytoxin-like compound presenting 2 oxygen atoms less than palytoxin. Toxin content was determined at the end of the stationary and exponential growth phases and reached the highest value in the Adriatic strain at the end of the stationary phase, with concentrations of 353.3 microg l(-1) for OVTX-a and 30.4 microg l(-1) for pPLTX. Toxin released in the growth medium was also measured and resulted to be the highest at the end of the stationary phase, suggesting that a long lasting bloom could enhance the toxin content in the water and cause toxic effects in people inhaling the aerosol. PMID:19638281

  18. Phenylethanoid glycosides and phenolic glycosides from stem bark of Magnolia officinalis.

    PubMed

    Xue, Zhenzhen; Yan, Renyi; Yang, Bin

    2016-07-01

    An investigation of the hydrophilic constituents of the stem bark of Magnolia officinalis was performed and which led to isolation and identification of twenty-one previously unreported glycosides. These included eleven phenylethanoid glycosides, magnolosides F-P, and ten phenolic glycosides, magnolosides Q-Z, along with eight known compounds. Their structures were elucidated on the basis of extensive spectroscopic analyses and chemical hydrolysis methods, as well as by comparison with literature data. Most of the phenylethanoid glycosides contained an allopyranose moiety, which is rare in the plant kingdom. Magnolosides I and K as well as 2-(3,4-dihydroxyphenyl) ethanol 1-O-[4-O-caffeoyl-2-O-α-l-rhamnopyranosyl-3-O-α-l-rhamnopyranosyl-6-O-β-d-glucopyranosyl]-β-d-glucopyranoside showed more potent α-glucosidase inhibitory effects (IC50 values of 0.13, 0.27, and 0.29mM, respectively) than the positive control, acarbose (IC50 value of 1.09mM) in vitro. Magnolosides H, E and D also showed moderate cytotoxicity against MGC-803 and HepG2 cells with IC50 values of 13.59-17.16μM and 29.53-32.46μM, respectively. PMID:27086163

  19. Extraction of polysaccharides and its antitumor activity on Magnolia kwangsiensis Figlar & Noot.

    PubMed

    Zheng, Yan-Fei; Zhang, Qiang; Liu, Xiong-Min; Ma, Li; Lai, Fang

    2016-05-20

    The crude polysaccharides from the leaves of Magnolia kwangsiensis Figlar & Noot. were extracted by hot water extraction, the yield was 5.09%. Two polysaccharide fractions (P-2 and P-3) were isolated by DEAE-52 cellulose chromatography and Sephadex G-100 column chromatography in order, respectively. P-2 and P-3 were characterized by IR, HPGPC and GC-MS. P-2 was comprised of only glucose. Its molecular weight was 11.2×10(3) Da and the formula was C414H690O345. P-3 was comprised of xylose and rhamnose in the ratio of 1:4. Its molecular weight was 7.8×10(3)Da, and the formula was C319H528O220. The antitumor activities of P-2 and P-3 on the growth of human lung cancer (A549) cells and human gastric carcinoma (SGC7901) cells in vitro were evaluated. The results indicated that P-3 exhibited marked antitumor activities with IC50 value of 8.48 and 5.66 μg/mL. PMID:26917379

  20. Thermogenesis, Flowering and the Association with Variation in Floral Odour Attractants in Magnolia sprengeri (Magnoliaceae)

    PubMed Central

    Wang, Ruohan; Xu, Sai; Liu, Xiangyu; Zhang, Yiyuan; Wang, Jianzhong; Zhang, Zhixiang

    2014-01-01

    Magnolia sprengeri Pamp. is an ornamentally and ecologically important tree that blooms at cold temperatures in early spring. In this study, thermogenesis and variation in the chemical compounds of floral odours and insect visitation in relation to flowering cycles were studied to increase our understanding of the role of floral thermogenesis in the pollination biology of M. sprengeri. There were five distinct floral stages across the floral cycle of this species: pre-pistillate, pistillate, pre-staminate, staminate and post-staminate. Floral thermogenesis during anthesis and consisted of two distinct peaks: one at the pistillate stage and the other at the staminate stage. Insects of five families visited M. sprengeri during the floral cycle, and sap beetles (Epuraea sp., Nitidulidae) were determined to be the most effective pollinators, whereas bees (Apis cerana, Apidae) were considered to be occasional pollinators. A strong fragrance was released during thermogenesis, consisting of 18 chemical compounds. Although the relative proportions of these compounds varied at different floral stages across anthesis, linalool, 1-iodo-2-methylundecane and 2,2,6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol were dominant. Importantly, we found that the floral blends released during the pistillate and staminate stages were very similar, and coincided with flower visitation by sap beetles and the two thermogenic episodes. Based on these results, we propose that odour acts as a signal for a reward (pollen) and that an odour mimicry of staminate-stage flowers occurs during the pistillate stage. PMID:24922537

  1. Molecular characterization and expression analyses of an anthocyanin synthase gene from Magnolia sprengeri Pamp.

    PubMed

    Shi, Shou-Guo; Li, Shan-Ju; Kang, Yong-Xiang; Liu, Jian-Jun

    2015-01-01

    Anthocyanin synthase (ANS), which catalyzes the conversion of colorless leucoanthocyanins into colored anthocyanins, is a key enzyme in the anthocyanin biosynthetic pathway. It plays important roles in plant development and defense. An ANS gene designated as MsANS was cloned from Magnolia sprengeri using rapid amplification of complementary DNA (cDNA) ends technology. The full-length MsANS is 1171-bp long and contains a 1080-bp open reading frame encoding a 360 amino acid polypeptide. In a sequence alignment analysis, the deduced MsANS protein showed high identity to ANS proteins from other plants: Prunus salicina var. cordata (74 % identity), Ampelopsis grossedentata (74 % identity), Pyrus communis (73 % identity), and Prunus avium (73 % identity). A structural analysis showed that MsANS belongs to 2-oxoglutarate (2OG)- and ferrous iron-dependent oxygenase family because it contains three binding sites for 2OG. Real-time quantitative polymerase chain reaction analyses showed that the transcript level of MsANS was 26-fold higher in red petals than in white petals. The accumulation of anthocyanins in petals of white, pink, and red M. sprengeri flowers was analyzed by HPLC. The main anthocyanin was cyanidin-3-o-glucoside chloride, and the red petals contained the highest concentration of this pigment. PMID:25315387

  2. Honokiol, a Lignan Biphenol Derived from the Magnolia Tree, Inhibits Dengue Virus Type 2 Infection.

    PubMed

    Fang, Chih-Yeu; Chen, Siang-Jyun; Wu, Huey-Nan; Ping, Yueh-Hsin; Lin, Ching-Yen; Shiuan, David; Chen, Chi-Long; Lee, Ying-Ray; Huang, Kao-Jean

    2015-09-01

    Dengue is the most widespread arbovirus infection and poses a serious health and economic issue in tropical and subtropical countries. Currently no licensed vaccine or compounds can be used to prevent or manage the severity of dengue virus (DENV) infection. Honokiol, a lignan biphenol derived from the Magnolia tree, is commonly used in Eastern medicine. Here we report that honokiol has profound antiviral activity against serotype 2 DENV (DENV-2). In addition to inhibiting the intracellular DENV-2 replicon, honokiol was shown to suppress the replication of DENV-2 in baby hamster kidney (BHK) and human hepatocarcinoma Huh7 cells. At the maximum non-toxic dose of honokiol treatment, the production of infectious DENV particles was reduced >90% in BHK and Huh7 cells. The underlying mechanisms revealed that the expression of DENV-2 nonstructural protein NS1/NS3 and its replicating intermediate, double-strand RNA, was dramatically reduced by honokiol treatment. Honokiol has no effect on the expression of DENV putative receptors, but may interfere with the endocytosis of DENV-2 by abrogating the co-localization of DENV envelope glycoprotein and the early endosomes. These results indicate that honokiol inhibits the replication, viral gene expression, and endocytotic process of DENV-2, making it a promising agent for chemotherapy of DENV infection. PMID:26378567

  3. Honokiol, a Lignan Biphenol Derived from the Magnolia Tree, Inhibits Dengue Virus Type 2 Infection

    PubMed Central

    Fang, Chih-Yeu; Chen, Siang-Jyun; Wu, Huey-Nan; Ping, Yueh-Hsin; Lin, Ching-Yen; Shiuan, David; Chen, Chi-Long; Lee, Ying-Ray; Huang, Kao-Jean

    2015-01-01

    Dengue is the most widespread arbovirus infection and poses a serious health and economic issue in tropical and subtropical countries. Currently no licensed vaccine or compounds can be used to prevent or manage the severity of dengue virus (DENV) infection. Honokiol, a lignan biphenol derived from the Magnolia tree, is commonly used in Eastern medicine. Here we report that honokiol has profound antiviral activity against serotype 2 DENV (DENV-2). In addition to inhibiting the intracellular DENV-2 replicon, honokiol was shown to suppress the replication of DENV-2 in baby hamster kidney (BHK) and human hepatocarcinoma Huh7 cells. At the maximum non-toxic dose of honokiol treatment, the production of infectious DENV particles was reduced >90% in BHK and Huh7 cells. The underlying mechanisms revealed that the expression of DENV-2 nonstructural protein NS1/NS3 and its replicating intermediate, double-strand RNA, was dramatically reduced by honokiol treatment. Honokiol has no effect on the expression of DENV putative receptors, but may interfere with the endocytosis of DENV-2 by abrogating the co-localization of DENV envelope glycoprotein and the early endosomes. These results indicate that honokiol inhibits the replication, viral gene expression, and endocytotic process of DENV-2, making it a promising agent for chemotherapy of DENV infection. PMID:26378567

  4. Cytotoxic and antiviral activities of aporphine alkaloids of Magnolia grandiflora L.

    PubMed

    Mohamed, S M; Hassan, E M; Ibrahim, N A

    2010-09-01

    Bioassay guided fractionation of the methanol extract of Magnolia grandiflora L. (Magnoliaceae) leaves led to the isolation and characterisation of four aporphine alkaloids, magnoflorine, lanuginosine, liriodenine and anonaine. The cytotoxicities of the pure compounds magnoflorine and lanuginosine were determined in a cell viability assay with the tumour cell lines Hela (cervix tumour cell line), HEPG2 (hepatocellular carcinoma cell line) and U251 (brain tumour cell line). Magnoflorine was more cytotoxic (IC(50) 0.4 microg mL(-1)) than lanuginosine (IC(50) 2.5 microg mL(-1)) against HEPG2 in comparison with the standard doxorubacin (IC(50) 0.27 microg mL(-1)). In addition, magnoflorine and lanuginosine exhibited cytotoxicity against U251, with IC(50) of 7 and 4 microg mL(-1), respectively. The two compounds were found to be inactive against the Hela cancer cell. On the other hand, the methanol extract showed high antiviral activity against the herpes simplex virus (HSV-1), 76.7% inhibition at 1.1 microg mL(-1), whereas the extract exhibited a moderate antiviral activity against poliovirus type-1 (47% inhibition at the same concentration). This chemical and biological investigation has not been studied previously. PMID:19764006

  5. Hydrosoluble fiber (Plantago ovata husk) and levodopa I: experimental study of the pharmacokinetic interaction.

    PubMed

    Garcia, Juan J; Fernandez, Nelida; Carriedo, Demetrio; Diez, M Jose; Sahagun, Ana; Gonzalez, Aranzazu; Calle, Angela; Sierra, Matilde

    2005-10-01

    Fiber therapy could be used in patients with Parkinson disease to reduce the symptoms of gastrointestinal disorders; however, it could interact with levodopa reducing its effectiveness. In this experimental study we have investigated whether the presence of Plantago ovata husk (water-soluble fiber) modifies in rabbits the bioavailability and other pharmacokinetic parameters of levodopa (20 mg/kg) when administered by the oral route at the same time. We have also studied whether pharmacokinetic modifications are fiber-dose dependent (100 and 400 mg/kg). The extent of levodopa absorbed when administering 100 mg/kg of fiber (AUC=43.4 mug min ml(-1)) is approximately the same as when levodopa is administered alone (AUC=47.1 microg min ml(-1)); however, Cmax is lower (1.04 versus 1.43 microg ml(-1)). Results obtained indicate that fiber at the higher dose increases the extent of levodopa absorbed (AUC=62.2 microg min ml(-1)), being the value of Cmax similar (1.46 microg ml(-1)). The value of tmax increases from 10 min when levodopa is administered alone to 20 min when the animals receive fiber. On the other hand, since certain time on, levodopa concentrations are always higher in the groups that receive fiber: 60 min with 100 mg/kg fiber and 20 min with 400 mg/kg fiber. Fiber also increases the mean residence time (MRT). P. ovata husk administration with levodopa could be beneficial, not only in patients with constipation, due to: lower adverse reactions (lower values of Cmax) and longer and more stable effects (higher final concentrations and more time in the body). PMID:16139166

  6. Alternative splicing of the AGAMOUS orthologous gene in double flower of Magnolia stellata (Magnoliaceae).

    PubMed

    Zhang, Bo; Liu, Zhi-Xiong; Ma, Jiang; Song, Yi; Chen, Fa-Ju

    2015-12-01

    Magnolia stellata is a woody ornamental shrub with more petaloid tepals than related plants from family Magnoliaceae. Recent studies revealed that expression changes in an AGAMOUS (AG) orthologous gene could resulted in double flowers with increased numbers of petals. We isolated three transcripts encoding different isoforms of a single AG orthologous gene, MastAG, mastag_2 and mastag_3, from M. stellata. Sequence alignments and Southern blot analyses suggested that MastAG was a single-copy gene in M. stellata genomes, and that mastag_2 and mastag_3 were abnormally spliced isoforms of MastAG. An 144bp exon skipping in MastAG results in the truncated mastag_2 protein lacking the completely I domain and 18 aa of the K1 subdomain, whereas an 165bp exon skipping of MastAG produces a truncated mastag_3 protein lacking 6 aa of the K3 subdomain and the completely C terminal region. Expression analyses showed that three alternative splicing (AS) isoforms expressed only in developing stamens and carpels. Functional analyses revealed that MastAG could mimic the endogenous AG to specify carpel identity, but failed to regulate stamen development in an Arabidopsis ag-1 mutant. Moreover, the key domain or subdomain deletions represented by mastag_2 and mastag_3 resulted in loss of C-function. However, ectopic expression of mastag_2 in Arabidopsis produced flowers with sepals converted into carpeloid organs, but without petals and stamens, whereas ectopic expression of mastag_3 in Arabidopsis could mimic the flower phenotype of the ag mutant and produced double flowers with homeotic transformation of stamens into petals and carpels into another ag flower. Our results also suggest that mastag_3 holds some potential for biotechnical engineering to create multi-petal phenotypes in commercial ornamental cultivars. PMID:26706078

  7. Characterization and molecular cloning of mannose-binding lectins from the Orchidaceae species Listera ovata, Epipactis helleborine and Cymbidium hybrid.

    PubMed

    Van Damme, J M; Smeets, K; Torrekens, S; Van Leuven, F; Peumans, W J

    1994-04-15

    Mannose-binding lectins were purified from the leaves of three Orchidaceae species, namely Listera ovata (twayblade), Epipactis helleborine (broad-leaved helleborine) and Cymbidium hybrid, using affinity chromatography on Mannose - Sepharose-4B. Apparently, the Orchidaceae lectins are dimeric proteins composed of lectin subunits of 12-13 kDa. All of the isolated lectins exhibit exclusive specificity towards mannose. A cDNA library constructed from poly(A) rich RNA isolated from leaves of L. ovata was screened for cDNA clones encoding the lectin using colony hybridization. Since N-terminal sequence analysis of the twayblade lectin revealed some sequence similarity to the previously cloned mannose-binding lectin Hippeastrum hybrid (amaryllis) ovaries, the amaryllis lectin cDNA clone was used as a probe to screen the L. ovata library. Subsequently, the cDNA clone encoding the L. ovata lectin was used to screen the cDNA libraries from the taxonomically related orchid species Cymbidium hybrid and E. helleborine. Sequence analysis of the lectin cDNA clones from different Orchidaceae species revealed approximately 50% sequence similarity both at the nucleotide and amino acid level. The Orchidaceae lectins are apparently translated from mRNAs consisting of approximately 800 nucleotides. The primary translation products are preproproteins which are converted into the mature lectins following post-translational modifications. Southern blot analysis of genomic DNA has shown that the lectins are most probably encoded by a family of closely related genes which is in good agreement with the sequence heterogeneity found between different lectin cDNA clones of one species. PMID:8174556

  8. Hydrosoluble fiber (Plantago ovata husk) and levodopa II: experimental study of the pharmacokinetic interaction in the presence of carbidopa.

    PubMed

    Fernandez, Nelida; Carriedo, Demetrio; Sierra, Matilde; Diez, M Jose; Sahagun, Ana; Calle, Angela; Gonzalez, Aranzazu; Garcia, Juan J

    2005-10-01

    Levodopa combined with carbidopa constitutes one of the most frequent medication in the treatment of Parkinson's disease. Plantago ovata husk (water-soluble fiber) improves levodopa absorption conditions, but when this drug is administered with carbidopa, fiber could reduce its effectiveness. The purpose of this study is to investigate whether the presence of P. ovata husk modifies in rabbits the bioavailability and other pharmacokinetic parameters of levodopa (20 mg/kg) when administered by the oral route with carbidopa (5 mg/kg). We have also studied whether pharmacokinetic modifications are fiber-dose dependent (100 and 400 mg/kg). When levodopa and carbidopa were administered with 100 mg/kg P. ovata husk, the value of AUC for levodopa diminishes 29.7% (sign, n=6, P<0.05) and Cmax 28.1% (sign, n=6, P<0.05) in relation to the values obtained when these drugs were administered without fiber. If the dose of fiber was 400 mg/kg, the decrease was smaller: 20.4% for AUC (no significant difference) and 24.6% for Cmax (sign, n=6, P<0.05), that may indicate an inhibitory action of AADC by the fiber or any of its partial hydrolysis products. On the other hand, since certain time on, levodopa concentrations are always higher in the groups that receive fiber: 210 min with 100 mg/kg and 150 min with 400 mg/kg. The administration of P. ovata husk with levodopa/carbidopa to patients with Parkinson disease could be beneficial and in particular in those patients who also suffer constipation due to an improvement of levodopa kinetic profile with higher final concentrations, a longer plasma half-life and lower Cmax. PMID:16139167

  9. Effects Of Myrcia Ovata Cambess. Essential Oil On Planktonic Growth Of Gastrointestinal Microorganisms and Biofilm Formation Of Enterococcus Faecalis

    PubMed Central

    Cândido, Cinthya S.; Portella, Cadmo Silton A.; Laranjeira, Bruno J.; da Silva, Sérgio S.; Arriaga, Angela M.C.; Santiago, Gilvandete M. P.; Gomes, Geovany A.; Almeida, Paulo César; Carvalho, Cibele B. M.

    2010-01-01

    The essential oil from the leaves of Myrcia ovata Cambess., commonly used in Brazil for the treatment of gastric illnesses, was screened for antimicrobial activity and action in the formation of microbial biofilms by Enterococcus faecalis. The oil was obtained by hydrodistillation using a clevenger-type system. Its chemical composition was analyzed using GC and GC-MS. Both MIC and MBC of the essential oil were determined by broth microdilution techniques and agar dilution method. The essential oil showed antimicrobial activity against E. faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella choleraesuis, Staphylococcus aureus, Streptococcus pneumoniae and Candida parapsilosis. The results showed that the essential oil of M. ovata Cambess. was effective against the formation of biofilm by E. faecalis when compared with the control. Four volatile compounds, representing 92.1 % of the oil, were identified and geranial was the major component (50.4 %). At the best of our knowledge, this is the first report of the chemical composition and antimicrobial activity of the essential oil from leaves of M. ovata. PMID:24031537

  10. Assessment of hormone-like activities in Ginkgo biloba, Elettaria cardamomum and Plantago ovata extracts using in vitro receptor-specific bioassays.

    PubMed

    Real, Macarena; Molina-Molina, José-Manuel; Jimenez, Jesús; Diéguez, Horacio R; Fernández, Mariana F; Olea, Nicolás

    2015-01-01

    Medicinal plants are widely used for the treatment of diseases and for the development of new drugs. This study was designed to determine the presence of hormone-like activities dependent on the activation of human estrogen receptor alpha (hERa) and/or androgen receptor (hAR) in methanol extracts prepared from three medicinal plants historically and currently used for therapeutic purposes: Ginkgo biloba leaves (GBL), Elettaria cardamomum seeds (ECS) and Plantago ovata seeds (POS). After a solid-liquid extraction (SLE) step, their effects on hERa function were assessed in MCF-7 breast cancer cells using the E-Screen bioassay, and their ability to induce hAR-mediated reporter gene expression was evaluated using the androgen-sensitive stable prostatic PALM cell line. Unlike POS extracts, GBL and ECS extracts showed estrogenic (0.07 and 0.20 nM E2Eq mg(-1), respectively) and anti-estrogenic (0.01 and 0.02 μM ICI182780Eq mg(-1), respectively) activities. ECS extracts evidenced androgenic activity (0.30 nM R1881Eq mg(-1)) and POS extracts anti-androgenic activity (22.30 μM ProcEq mg(-1)). According to these findings, these plant extracts may interfere with the endocrine system via one or more hormonal receptors, and further investigation is warranted into their role as endocrine disrupters in humans. PMID:26161806

  11. Simultaneous quantification of eight bioactive secondary metabolites from Codonopsis ovata by validated high performance thin layer chromatography and their antioxidant profile.

    PubMed

    Dar, Alamgir A; Sangwan, Payare L; Khan, Imran; Gupta, Nidhi; Qaudri, Afnan; Tasduq, Sheikh A; Kitchlu, Surinder; Kumar, Anil; Koul, Surrinder

    2014-11-01

    Chemical investigation of Codonopsis ovata resulted in the isolation and identification of β-sitosterol-3-O-glycoside, luteolin, apigenin, gentiacaulein, swertiaperenine, β-sitosterol, taraxeryl-3-acetate, and 3β-acetoxyoleanane-12-one. A rapid, precise, sensitive and validated HPTLC method for simultaneous quantification of these natural products (NPs) was developed on silica-gel 60F254 plate using ternary solvent system, n-hexane:ethyl acetate:formic acid (10.5:3.5:0.43, v/v/v). Markers were quantified after post chromatographic derivatization with cerric ammonium sulfate reagent. The method was validated for accuracy, precision, LOD, LOQ and all calibration curves showed a good linear relationship (r>0.9924) within test range. Precision was evaluated by intra- and inter-day tests with RSDs <2.59%, accuracy validation recovery 92.43-99.50% with RSDs <1.00%. Apigenin was found major component (natural abundance: 1.103%) and β-sitosterol the least (0.0263%). The NPs displayed antioxidant activity with luteolin exhibiting maximum effect at 1μg/mL concentration (75.9% for DPPH and 43.7% for ABTS) and others at 10 and 25μg/mL, suggesting thereby their apparent potential use for the prevention of free radical induced diseases or as an additive element to food and pharmaceutical industry. PMID:25194343

  12. Magnolia Extract, Magnolol, and Metabolites: Activation of Cannabinoid CB2 Receptors and Blockade of the Related GPR55

    PubMed Central

    2012-01-01

    The bark of Magnolia officinalis is used in Asian traditional medicine for the treatment of anxiety, sleeping disorders, and allergic diseases. We found that the extract and its main bioactive constituents, magnolol and honokiol, can activate cannabinoid (CB) receptors. In cAMP accumulation studies, magnolol behaved as a partial agonist (EC50 = 3.28 μM) with selectivity for the CB2 subtype, while honokiol was less potent showing full agonistic activity at CB1 and antagonistic properties at CB2. We subsequently synthesized the major metabolites of magnolol and found that tetrahydromagnolol (7) was 19-fold more potent than magnolol (EC50 CB2 = 0.170 μM) exhibiting high selectivity versus CB1. Additionally, 7 behaved as an antagonist at GPR55, a CB-related orphan receptor (KB = 13.3 μM, β-arrestin translocation assay). Magnolol and its metabolites may contribute to the biological activities of Magnolia extract via the observed mechanisms of action. Furthermore, the biphenylic compound magnolol provides a simple novel lead structure for the development of agonists for CB receptors and antagonists for the related GPR55. PMID:24900561

  13. An HPLC-DAD method for simultaneous quantitative determination of four active hydrophilic compounds in Magnoliae officinalis cortex.

    PubMed

    Yan, Renyi; Yu, Shengxian; Liu, Hongliang; Xue, Zhenzhen; Yang, Bin

    2015-04-01

    Magnoliae officinalis cortex (MOC), derived from Magnolia officinalis and its variation M. officinalis var. biloba, is an important traditional Chinese medicine. In our previous work, 11 hydrophilic ingredients of MOC were isolated and structurally elucidated and four, namely syringin (SG), magnoloside A (MA), magnoloside B (MB) and magnoflorine (MF), showed bioactive effects. Herein, we describe an HPLC-DAD method for the simultaneous quantitative determination of MA, MB, MF and SG in MOC for the first time. The chromatographic separation of samples was performed on an Agilent Zorbax SB-C18 column (250 × 4.6 mm i.d., 5 µm) by gradient elution with water-acetic acid (pH 3.0) and methanol at a flow rate of 1.0 mL/min. The wavelengths were set at 265 nm for MF and SG, and 328 nm for MA and MB. The average recovery of the four compounds was from 97.63 to 103.84%. Nearly 100 MOC samples harvested from eight habitats were analyzed in which the contents of the tested compound varied in the range of 0.016-0.350% (MF), 0.010-0.337% (SG), 0.017-3.009% (MB) and 0.077-2.529% (MA). The analysis also indicated that MOC contains a significant amount of phenylethanoid glycosides. This was an unexpected finding because previously lignan was considered to be the main component of MOC. PMID:25085894

  14. [Micronization of magnolia bark extract by RESS as well as dissolution and pharmacokinetics evaluation].

    PubMed

    He, Shuai; Lei, Zheng-jie; Zhang, Shou-yao; Zhang, Zhong-yi

    2009-05-01

    The purpose of this study is to explore the feasibility and superiority of using rapid expansion of supercritical solution (RESS) technology in the field of traditional Chinese medicine. The extract of magnolia bark (EMB) was obtained by supercritical carbon dioxide (SCF-CO2) extraction technology. Microparticles of EMB were manufactured by RESS technology. The effects of operating temperature and pressure on the contents of the active ingredient in the particles were evaluated by HPLC. The effect of expansion conditions on the particle size distribution of EMB particles was investigated. The smallest sample (mean size: 4.7 microm) was obtained under the RESS condition: pressure of 25 MPa, temperature of 50 degrees C and a nozzle size of 100 microm. The characteristics of microparticles were also studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and image analysis. The dissolution rate study showed that microparticles had a significantly faster dissolution rate than normal material particles. After oral raw EMB suspension, the mean areas under the plasma concentration-time curves (AUC(0-t)) of honokiol and magnolol were found to be (4.23 +/- 0.36) and (5.46 +/- 0.57) mg x h x L(-1), respectively, which were increased significantly, i.e. (5.41 +/- 0.63) and (7.24 +/- 0.83) mg x h x L(-1) when micronized EMB suspension was administered orally in SD rats (P < 0.05). Similarly, the mean maximum plasma concentrations of honokiol and magnolol increased from (1.55 +/- 0.22) and (2.35 +/- 0.14) mg x L(-1) (raw EMB) to (2.31 +/- 0.17) and (2.84 +/- 0.21) mg x L(-1) (micronized EMB), respectively. The results of t-test demonstrated that AUC(0-t) and Cmax value for honokiol and magnolol was significantly increased with the micronization compared to raw EBM (P < 0.05). This study demonstrated that the RESS was applicable for preparing microparticles of EMB at low operating temperature. The process was simple, free of environment pollution

  15. Aqueous extracts of husks of Plantago ovata reduce hyperglycaemia in type 1 and type 2 diabetes by inhibition of intestinal glucose absorption.

    PubMed

    Hannan, J M A; Ali, L; Khaleque, J; Akhter, M; Flatt, P R; Abdel-Wahab, Y H A

    2006-07-01

    Plantago ovata has been reported to reduce postprandial glucose concentrations in diabetic patients. In the present study, the efficacy and possible modes of action of hot-water extracts of husk of P. ovata were evaluated. The administration of P. ovata (0.5 g/kg body weight) significantly improved glucose tolerance in normal, type 1 and type 2 diabetic rat models. When the extract was administered orally with sucrose solution, it suppressed postprandial blood glucose and retarded small intestinal absorption without inducing the influx of sucrose into the large intestine. The extract significantly reduced glucose absorption in the gut during in situ perfusion of small intestine in non-diabetic rats. In 28 d chronic feeding studies in type 2 diabetic rat models, the extract reduced serum atherogenic lipids and NEFA but had no effect on plasma insulin and total antioxidant status. No effect of the extract was evident on intestinal disaccharidase activity. Furthermore, the extract did not stimulate insulin secretion in perfused rat pancreas, isolated rat islets or clonal beta cells. Neither did the extract affect glucose transport in 3T3 adipocytes. In conclusion, aqueous extracts of P. ovata reduce hyperglycaemia in diabetes via inhibition of intestinal glucose absorption and enhancement of motility. These attributes indicate that P. ovata may be a useful source of active components to provide new opportunities for diabetes therapy. PMID:16870001

  16. The effect of Plantago ovata on humoral immune responses in experimental animals.

    PubMed

    Rezaeipoor, R; Saeidnia, S; Kamalinejad, M

    2000-09-01

    The effect of the aqueous extract of Plantago ovata (PO) (Plantaginaceae) consisting of a mixture of polysaccharides and glycoside on humoral immune responses was studied. In rabbits, after oral administration of PO (0.5 g/kg) a significant decrease in anti-HD antibody titre was observed in primary response. Intraperitoneal injection of 0.25 g/kg of PO in mice prior to immunisation with sheep red blood cells (SRBC) resulted in a significant decrease in hemagglutinating antibody (HD) titre. Oral administration and intraperitoneal injection of 0.25 and 0.5 g/kg of PO resulted in a significant increase in white blood cells (WBC) and spleen leukocytes counts. The spleen weight also increased with intraperitoneal injection (0.25 and 0.5 g/kg) and oral administration of 0.5 g/kg of PO. Present results indicate that PO can suppress the humoral immune responses, especially in primary immune response. PMID:10967483

  17. Effects of light intensity and temperature on Cryptomonas ovata (Cryptophyceae) growth and nutrient uptake rates

    USGS Publications Warehouse

    Cloern, James E.

    1977-01-01

    Specific growth rate of Cryptomonas ovata var. palustris Pringsheim was measured in batch culture at 14 light-temperature combinations. Both the maximum growth rate (μm) and optimum light intensity (Iopt) fit an empirical function that increases exponentially with temperature up to an optimum (Topt), then declines rapidly as temperature exceeds Topt. Incorporation of these functions into Steele's growth equation gives a good estimate of specific growth rate over a wide range of temperature and light intensity. Rates of phosphate, ammonium and nitrate uptake were measured separately at 16 combinations of irradiance and temperature and following a spike addition of all starved cells initially took up nutrient at a rapid rate. This transitory surge was followed by a period of steady, substrate-saturated uptake that persisted until external nutrient concentration fell. Substrate-saturated NO3−-uptake proceeded at very slow rates in the dark and was stimulated by both increased temperature and irradiance; NH4+-uptake apparently proceeded at a basal rate at 8 and l4 C and was also stimulated by increased temperature and irradiance. Rates of NH4−-uptake were much higher than NO3−-uptake at all light-temperature combinations. Below 20 C, PO4−3-uptake was more rapid in dark than in light, but was light enhanced at 26 C.

  18. The gel-forming polysaccharide of psyllium husk (Plantago ovata Forsk).

    PubMed

    Fischer, Milton H; Yu, Nanxiong; Gray, Gary R; Ralph, John; Anderson, Laurens; Marlett, Judith A

    2004-08-01

    The physiologically active, gel-forming fraction of the alkali-extractable polysaccharides of Plantago ovata Forsk seed husk (psyllium seed) and some derived partial hydrolysis products were studied by compositional and methylation analysis and NMR spectroscopy. Resolving the conflicting claims of previous investigators, the material was found to be a neutral arabinoxylan (arabinose 22.6%, xylose 74.6%, molar basis; only traces of other sugars). With about 35% of nonreducing terminal residues, the polysaccharide is highly branched. The data are compatible with a structure consisting of a densely substituted main chain of beta-(1-->4)-linked D-xylopyranosyl residues, some carrying single xylopyranosyl side chains at position 2, others bearing, at position 3, trisaccharide branches having the sequence L-Araf-alpha-(1-->3)-D-Xylp-beta-(1-->3)-l-Araf. The presence of this sequence is supported by methylation and NMR data, and by the isolation of the disaccharide 3-O-beta-D-xylopyranosyl-L-arabinose as a product of partial acid hydrolysis of the polysaccharide. PMID:15261594

  19. Antidepressant-like synergism of extracts from magnolia bark and ginger rhizome alone and in combination in mice.

    PubMed

    Yi, Li-Tao; Xu, Qun; Li, Yu-Cheng; Yang, Lei; Kong, Ling-Dong

    2009-06-15

    Magnolia bark and ginger rhizome is a drug pair in many prescriptions for treatment of mental disorders in traditional Chinese medicine (TCM). However, compatibility and synergism mechanism of two herbs on antidepressant actions have not been reported. The aim of this study was to approach the rationale of the drug pair in TCM. We evaluated antidepressant-like effects of mixture of honokiol and magnolol (HMM), polysaccharides (PMB) from magnolia bark, essential oil (OGR) and polysaccharides (PGR) from ginger rhizome alone, and the possibility of synergistic interactions in their combinations in the mouse forced swimming test (FST) and tail suspension test (TST). Serotonin (5-HT) and noradrenaline (NE) levels in prefrontal cortex, hippocampus and striatum were also examined. 30 mg/kg HMM decreased immobility in the FST and TST in mice after one- and two-week treatment. OGR (19.5 or 39 mg/kg) alone was ineffective. The combination of an ineffective dose of 39 mg/kg OGR with 15 mg/kg HMM was the most effective and produced a synergistic action on behaviors after two-week treatment. Significant increase in 5-HT and synergistic increase in NE in prefrontal cortex were observed after co-administration of HMM with OGR. These results demonstrated that HMM was the principal component of this drug pair, whereas OGR served as adjuvant fraction. Compatibility of HMM with OGR was suggested to exert synergistic antidepressant actions by attenuating abnormalities in serotonergic and noradrenergic system functions. Therefore, we confirmed the rationality of drug pair in clinical application and provided a novel perspective in drug pair of TCM researches. PMID:19285110

  20. [DNA-containing polygonal structures detected in somatic nuclei of Bursaria ovata during preparation to cryptobiosis].

    PubMed

    Sergeeva, G I; Samoshkin, A A

    2002-01-01

    Supramolecular chromatin organization of the somatic nucleus (macronucleus--Ma) was studied in a free-living unicellular eukaryotic organism, the ciliate Bursaria ovata Beers 1952, at two late successive stages of its encystment (in the state of preparation to cryptobiosis). A modified Miller's method (Sergejeva et al., 1987) and the same technique in combination with high resolution DNA autoradiography were used. In chromatin spread preparations of Ma, not labeled by 3H-thymidine, numerous electron dense structures (rounded, stick-like and polygonal) were revealed, along with rarely occurring typical supramolecular chromatin structures, such as nucleosomic and not nucleosomic threads, nucleomeres, chromomeres, rosette-like looping chromatin, and electron dense chromonemes (Fig. 1). For DNA visualizing in the revealed polygonal structures, the vegetative cells (trophonts) of B. ovata were inoculated into the culture medium, containing 3H-thymidine and food (ciliates Paramecium caudatum). Here, the ciliates passed through 3-4 successive cell division cycles, thus progressively accumulating the radioactive DNA precursor in Ma. After washing the ciliates in 3H-thymidine-free culture medium, the process of their encystment was induced, and Ma were isolated by hand from the ciliates being at two late successive stages of encystment. Isolated Ma were dispersed in the low ionic solutions, as described elsewhere (Sergejeva et al., 1987). The carbon shadowed electron grids, that contained spread Ma preparations, were individually coated with photographic emulsion, according to the loop interference method (Angelier et al., 1976a; Bouteille, 1976). After a 6 month exposure at 4 degrees C, thymidine incorporation was revealed in fibril crowds, rosette-like structures (Fig. 2), and crystal-like plates of different size and morphology (Fig. 3). In all our experiments, non-specific localization of radioactive DNA precursor was not observed. The above data confirm undoubtedly our

  1. Axis establishment and microtubule-mediated waves prior to first cleavage in Beroe ovata.

    PubMed

    Houliston, E; Carré, D; Johnston, J A; Sardet, C

    1993-01-01

    The single axis (oral-aboral) and two planes of symmetry of the ctenophore Beroe ovata become established with respect to the position of zygote nucleus formation and the orientation of first cleavage. Bisection of Beroe eggs at different times revealed that differences in egg organisation are established in relation to the presumptive oral-aboral axis before first cleavage. Lateral fragments produced after but not before the time of first mitosis developed into larvae lacking comb-plates on one side. Time-lapse video demonstrated that waves of cytoplasmic reorganisation spread through the layer of peripheral cytoplasm (ectoplasm) of the egg during the 80 minute period between pronuclear fusion and first cleavage, along the future oral-aboral axis. These waves are manifest as the progressive displacement and dispersal of plaques of accumulated organelles around supernumerary sperm nuclei, and a series of surface movements. Their timing and direction of propagation suggest they may be involved in establishing cytoplasmic differences with respect to the embryonic axis. Inhibitor experiments suggested that the observed cytoplasmic reorganisation involves microtubules. Nocodazole and taxol, which prevent microtubule turnover,blocked plaque dispersal and reduced surface movements. The microfilament-disrupting drug cytochalasin B did not prevent plaque dispersal but induced abnormal surface contractions. We examined changes in microtubule organisation using immunofluorescence on eggs fixed at different times and in live eggs following injection of rhodamine-tubulin. Giant microtubule asters become associated with each male pronucleus after the end of meiosis. Following pronuclear fusion they disappear successively, those nearest the zygote nucleus shrinking first, to establish gradients of aster size within single eggs. Regional differences in microtubule behaviour around the time of mitosis were revealed by brief taxol treatment, which induced the formation of small

  2. Physicochemical characterization and evaluation of suspending properties of arabinoxylan from Ispaghula (Plantago ovata) husk.

    PubMed

    Bashir, Sajid; Erum, Alia; Saghir, Shazia; Tulain, Umme Ruqia; Rashid, Ayesha

    2014-11-01

    The purpose of this study is to evaluate the use of arabinoxylan as potential suspending agent, an effective alternative to commercially used excipients for the preparation of pharmaceutical suspensions. Alkali extraction was done to separate arabinoxylan from ispaghula (Plantago ovata) seed husk by alkali extraction its physicochemical characterization was done and the suspending properties of arabinoxylan isolated were evaluated comparatively with those of bentonite at different concentration ranges of 0.125,0.25,0.5 and 1% in Zinc oxide suspension. The parameters employed for evaluation were sedimentation volume, degree of flocculation, flow rate, density, pH, redispersibility, microbiological evaluation and particle size analysis. Physicochemical characterization of arabinoxylan indicates its suitability as excipient as it has fair flow properties, low moisture content and almost neutral pH. Arabinoxylan at low conc. 0.125% showed sedimentation volume comparable to commercially used suspending agents such as bentonite 1% while suspensions containing higher concentrations such as 0.25% (sedimentation volume 92%), 0.5% (sedimentation volume 94%) and 1% conc. (sedimentation volume 98%) of arabinoxylan remained almost completely suspended during study period of 7 days. Formulations containing 0.125% and 0.25% arabinoxylan as suspending agents are easily redispersible as compared to bentonite containing formulation while formulation containing 0.5% arabinoxylan are moderately redispersible while formulation containing 1% suspending agent gel upon storage and was not redispersible. Furthermore arabinoxylan produces stable, highly flocculated suspension, which fulfilled microbiological, and particle size specifications, however the formulations containing higher arabinoxylan 1% concentration gel upon storage. So it is concluded that arabinoxylan could be used as effective suspending agent at low concentrations in Zinc oxide suspension. PMID:25362588

  3. Ball milling improves extractability and affects molecular properties of psyllium (Plantago ovata Forsk) seed husk arabinoxylan.

    PubMed

    Van Craeyveld, Valerie; Delcour, Jan A; Courtin, Christophe M

    2008-12-10

    Psyllium (Plantago ovata Forsk) seed husk (PSH) is very rich in arabinoxylan (AX). However, its high gelling capacity and the complex nature of the AX make it difficult to process. In this study, ball milling was investigated as a tool for enhancing PSH AX water extractability and molecular mass (MM). A 48 h laboratory-scale ball mill treatment under standardized optimal conditions reduced the PSH average particle size from 161 microm for the untreated sample to 6 microm. Concurrently, it increased the water-extractable AX (WE-AX) level from 13 (untreated PSH) to 90% of the total PSH AX. While the WE-AX of the untreated PSH had a peak MM of 216 kDa and an arabinose to xylose (A/X) ratio of 0.20, WE-AX fragments from ball mill-pretreated PSH had a peak MM of 22 kDa and an A/X ratio of 0.31. Ball milling further drastically reduced the intrinsic viscosity of PSH extracts and their water-holding capacity. Prolonged treatment brought almost all AX (98%) in solution and yielded WE-AX fragments with an even higher A/X ratio (0.42) and a lower peak MM (11 kDa). While impact and jet milling of PSH equally led to significant reductions in particle size, these technologies only marginally affected the water extractability of PSH AX. This implies that ball milling affects PSH particles and their constituent molecules differently than impact and jet milling. PMID:19007123

  4. Transmission of the Aegilops ovata chromosomes carrying gametocidal factors in hexaploid triticale (×Triticosecale Wittm.) hybrids.

    PubMed

    Kwiatek, M; Majka, M; Ślusarkiewicz-Jarzina, A; Ponitka, A; Pudelska, H; Belter, J; Wiśniewska, H

    2016-08-01

    The main aim of this work was to induce the chromosome rearrangements between Aegilops ovata (UUMM) and hexaploid triticale (AABBRR) by expression of the gametocidal factor located on the chromosome 4M. The Aegilops ovata × Secale cereale (UUMMRR) amphiploids and triticale 'Moreno' were used to produce hybrids by reciprocal crosses. Chromosome dynamics was observed in subsequent generations of hybrids during mitotic metaphase of root meristems and first metaphase of meiosis of pollen mother cells. Chromosomes were identified by genomic in situ hybridisation (GISH) and fluorescence in situ hybridisation (FISH) using pTa71, pTa791, pSc119.2 and pAs1 DNA probes. It has been shown that the origin of the genetic background had an influence on Aegilops chromosome transmission. Moreover, it has been reported that the preferential transmission of chromosome 4M appeared during both androgenesis and gynogenesis. It is also hypothesised that the expression of the triticale Gc gene suppressor had an influence on the semi-fertility of hybrids but did not inhibit the chromosome rearrangements. This paper also describes the double haploid production, which enabled to obtain plants with two identical copies of triticale chromosomes with translocations of Aegilops chromatin segments. PMID:26825077

  5. In vitro fertilization in ctenophores: sperm entry, mitosis, and the establishment of bilateral symmetry in Beroe ovata.

    PubMed

    Carré, D; Rouvière, C; Sardet, C

    1991-10-01

    We have found ways to control in vitro fertilization in a ctenophore (Beroe ovata) for the first time. This is based on the existence of a partial block to self-fertilization at the time of gamete release which can be overcome by removal of the egg envelope. It has allowed us to exploit the excellent optical properties of Beroe eggs to make detailed observations on all events from sperm penetration or penetrations in these physiologically polyspermic eggs to first cleavage, and to extend our initial observations (Carré and Sardet, 1984). Sperm entry is characterized by local modifications of the egg cortex in a 70-microns zone around the penetration site or sites. Upon sperm entry, the egg surface contracts and relaxes locally, then a fertilization cone forms and disappears. These events are accompanied by localized exocytosis, growth of a ring of microvilli, thickening of the egg cortex, and gathering of mitochondria around the sperm pronuclei. The female pronucleus then migrates beneath the egg surface toward one or successive sperm pronuclei. The fusion of pronuclei, sperm and egg chromatin intermixing, and mitosis were also observed with exceptional clarity. Furthermore, we have noticed that the direction of the last trajectory of the female pronucleus tends to define the orientation of the mitotic spindle, and as a consequence the position of first unipolar cleavage furrow. This in turn determines the future sagittal plane of the embryo and of the adult B. ovata. PMID:1680762

  6. Adaptation of the autotrophic acetogen Sporomusa ovata to methanol accelerates the conversion of CO2 to organic products.

    PubMed

    Tremblay, Pier-Luc; Höglund, Daniel; Koza, Anna; Bonde, Ida; Zhang, Tian

    2015-01-01

    Acetogens are efficient microbial catalysts for bioprocesses converting C1 compounds into organic products. Here, an adaptive laboratory evolution approach was implemented to adapt Sporomusa ovata for faster autotrophic metabolism and CO2 conversion to organic chemicals. S. ovata was first adapted to grow quicker autotrophically with methanol, a toxic C1 compound, as the sole substrate. Better growth on different concentrations of methanol and with H2-CO2 indicated the adapted strain had a more efficient autotrophic metabolism and a higher tolerance to solvent. The growth rate on methanol was increased 5-fold. Furthermore, acetate production rate from CO2 with an electrode serving as the electron donor was increased 6.5-fold confirming that the acceleration of the autotrophic metabolism of the adapted strain is independent of the electron donor provided. Whole-genome sequencing, transcriptomic, and biochemical studies revealed that the molecular mechanisms responsible for the novel characteristics of the adapted strain were associated with the methanol oxidation pathway and the Wood-Ljungdahl pathway of acetogens along with biosynthetic pathways, cell wall components, and protein chaperones. The results demonstrate that an efficient strategy to increase rates of CO2 conversion in bioprocesses like microbial electrosynthesis is to evolve the microbial catalyst by adaptive laboratory evolution to optimize its autotrophic metabolism. PMID:26530351

  7. Adaptation of the autotrophic acetogen Sporomusa ovata to methanol accelerates the conversion of CO2 to organic products

    PubMed Central

    Tremblay, Pier-Luc; Höglund, Daniel; Koza, Anna; Bonde, Ida; Zhang, Tian

    2015-01-01

    Acetogens are efficient microbial catalysts for bioprocesses converting C1 compounds into organic products. Here, an adaptive laboratory evolution approach was implemented to adapt Sporomusa ovata for faster autotrophic metabolism and CO2 conversion to organic chemicals. S. ovata was first adapted to grow quicker autotrophically with methanol, a toxic C1 compound, as the sole substrate. Better growth on different concentrations of methanol and with H2-CO2 indicated the adapted strain had a more efficient autotrophic metabolism and a higher tolerance to solvent. The growth rate on methanol was increased 5-fold. Furthermore, acetate production rate from CO2 with an electrode serving as the electron donor was increased 6.5-fold confirming that the acceleration of the autotrophic metabolism of the adapted strain is independent of the electron donor provided. Whole-genome sequencing, transcriptomic, and biochemical studies revealed that the molecular mechanisms responsible for the novel characteristics of the adapted strain were associated with the methanol oxidation pathway and the Wood-Ljungdahl pathway of acetogens along with biosynthetic pathways, cell wall components, and protein chaperones. The results demonstrate that an efficient strategy to increase rates of CO2 conversion in bioprocesses like microbial electrosynthesis is to evolve the microbial catalyst by adaptive laboratory evolution to optimize its autotrophic metabolism. PMID:26530351

  8. Magnolia extract (BL153) protection of heart from lipid accumulation caused cardiac oxidative damage, inflammation, and cell death in high-fat diet fed mice.

    PubMed

    Sun, Weixia; Zhang, Zhiguo; Chen, Qiang; Yin, Xia; Fu, Yaowen; Zheng, Yang; Cai, Lu; Kim, Ki-Soo; Kim, Ki Ho; Tan, Yi; Kim, Young Heui

    2014-01-01

    Magnolia as an herbal material obtained from Magnolia officinalis has been found to play an important role in anti-inflammation, antioxidative stress, and antiapoptosis. This study was designed to investigate the effect of Magnolia extract (BL153) on obesity-associated lipid accumulation, inflammation, oxidative stress, and apoptosis in the heart. C57BL/6 mice were fed a low- (10 kcal% fat) or high-fat (60 kcal% fat) diet for 24 weeks to induce obesity. These mice fed with high-fat diet (HFD) were given a gavage of vehicle, 2.5, 5, or 10 mg/kg body weight BL153 daily. The three doses of BL153 treatment slightly ameliorated insulin resistance without decrease of body weight gain induced by HFD feeding. BL153 at 10 mg/kg slightly attenuated a mild cardiac hypertrophy and dysfunction induced by HFD feeding. Both 5 mg/kg and 10 mg/kg of BL153 treatment significantly inhibited cardiac lipid accumulation measured by Oil Red O staining and improved cardiac inflammation and oxidative stress by downregulating ICAM-1, TNF-α, PAI-1, 3-NT, and 4-HNE. TUNEL staining showed that BL153 treatment also ameliorated apoptosis induced by mitochondrial caspase-3 independent cell death pathway. This study demonstrates that BL153 attenuates HFD-associated cardiac damage through prevention of HFD-induced cardiac lipid accumulation, inflammation, oxidative stress, and apoptosis. PMID:24693333

  9. Stool-fermented Plantago ovata husk induces apoptosis in colorectal cancer cells independently of molecular phenotype.

    PubMed

    Sohn, Vanessa R; Giros, Anna; Xicola, Rosa M; Fluvià, Lourdes; Grzybowski, Mike; Anguera, Anna; Llor, Xavier

    2012-06-01

    Several studies have suggested that the partially fermentable fibre Plantago ovata husk (PO) may have a protective effect on colorectal cancer (CRC). We studied the potentially pro-apoptotic effect of PO and the implicated mechanisms in CRC cells with different molecular phenotypes (Caco-2, HCT116, LoVo, HT-29, SW480) after PO anaerobic fermentation with colonic bacteria as it occurs in the human colon. The fermentation products of PO induced apoptosis in all primary tumour and metastatic cell lines, independent of p53, adenomatous polyposis coli, β-catenin or cyclo-oxygenase-2 status. Apoptosis was caspase-dependent and both intrinsic and extrinsic pathways were implicated. The intrinsic pathway was activated through a shift in the balance towards a pro-apoptotic environment with an up-regulation of B-cell lymphoma protein 2 homologous antagonist killer (BAK) and a down-regulation of B-cell lymphoma-extra large (Bcl-xL) seen in HCT116 and LoVo cells. This resulted in mitochondrial membrane depolarisation, increased expression of caspase activators second mitochondria-derived activator of caspases (Smac)/Diablo, death effector apoptosis-inducing factor, apoptosome member apoptotic protease activating factor 1 and down-regulation of inhibitors of apoptosis Survivin and X-linked inhibitor of apoptosis in most cells. The extrinsic pathway was activated presumably through the up-regulation of death receptor (DR5). Some important differences were seen between primary tumour and metastatic CRC cells. Thus, metastatic PO-treated LoVo cells had a remarkable up-regulation of TNF-α ligand along with death-inducing signalling complex components receptor interacting protein and TNF-α receptor 1-associated death domain protein. The extrinsic pathway modulator FCICE-inhibitory protein (FLIP), an inhibitor of both spontaneous death ligand-independent and death receptor-mediated apoptosis, was significantly down-regulated after PO treatment in all primary tumour cells, but not

  10. Effect of Chemical Profiling Change of Processed Magnolia officinalis on the Pharmacokinetic Profiling of Honokiol and Magnolol in Rats.

    PubMed

    Hu, Huiling; Wang, Zhanguo; Hua, Wan; You, Yu; Zou, Liang

    2016-08-01

    The stem of Magnoliae officinalis (MO) cortex is always preliminarily processed before being applied in traditional Chinese medicine. The definite bioavailability of honokiol (HO) and magnolol (MA) in processed MO (PMO) and the effect of chemical profiling change on the pharmacokinetics of HO and MA are always a greater challenge compared with those of MO. Compared with that of MO, the pharmacokinetic profiling of HO and MA in the PMO was significantly changed and the mean Tmax of HO and MA was increased by 31 and 50% (P < 0.05), respectively; the mean AUC0-t and Cmax of HO were increased by 36 and 24% (P < 0.05), respectively. Subsequently, the chemical profiling of MO and PMO was investigated by a simple and rapid LC-Q/TOF-MS coupled with multivariate analysis method. Principal component analysis and hierarchical cluster analysis of the chromatographic data demonstrated that the chemical profiling of PMO was significantly different from that of MO. Eight marker components including six alkaloids (magnocurarine, magnoflorine, roemerine and three unidentified peaks) and two lignans (obovatol and MA) were screened out by partial least-squares discriminant analysis. The results indicated that the changes of eight marker components of PMO may have an effect on the pharmacokinetic profiles of HO and MA. PMID:27107095

  11. Analysis of volatile compositions of Magnolia biondii pamp by steam distillation and headspace solid phase micro-extraction.

    PubMed

    Zeng, Zhi; Xie, Runqian; Zhang, Tao; Zhang, Han; Chen, Jie Yu

    2011-01-01

    The chemical compositions of volatile components from Magnolia biondii Pamp were determined by steam distillation (SD) and headspace solid phase micro-extraction (HS-SPME) followed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Fifty-six compounds were identified and the major volatile components were d-camphor (0.18-43.26%), 1,8-cineol (13.23-38.02%), α-terpineol (6.57-12.29%) and α-cadinene (5.53-15.15%). The comparison of the volatile components from M. biondii Pamp harvested in three regions of China was investigated. Also, the comparison of volatile components by SD and HS-SPME methods in term of isolation time, plant-consuming and chemical compositions was discussed as well. The percentages of the volatile components by HS-SPME method were found to be large difference from the corresponding one by SD method. HS-SPME technique was much faster than SD (60 min (HS-SPME)/420 min (SD)). Although the aromatic profiles between HS-SPME and SD methods showed several quantitative differences, HS-SPME may be applied routinely to analyze aromatic and medicinal plants. PMID:22123239

  12. Taspine: Bioactivity-Guided Isolation and Molecular Ligand–Target Insight of a Potent Acetylcholinesterase Inhibitor from Magnolia x soulangiana

    PubMed Central

    Rollinger, Judith M.; Schuster, Daniela; Baier, Elisabeth; Ellmerer, Ernst P.; Langer, Thierry; Stuppner, Hermann

    2012-01-01

    A bioactivity-guided approach was taken to identify the acetylcholinesterase (AChE, EC 3.1.1.7) inhibitory agent in a Magnolia x soulangiana extract using a microplate enzyme assay with Ellman’s reagent. This permitted the isolation of the alkaloids taspine (1) and (−)-asimilobine (2), which were detected for the first time in this species. Compound 1 showed a significantly higher effect on AChE than the positive control galanthamine and selectively inhibited the enzyme in a long-lasting and concentration-dependent fashion with an IC50 value of 0.33 ± 0.07 μM. Extensive molecular docking studies were performed with human and Torpedo californica-AChE employing Gold software to rationalize the binding interaction. The results suggested ligand 1 to bind in an alternative binding orientation when compared to galanthamine. While this is located in close vicinity to the catalytic amino acid triad, the 1–AChE complex was found to be stabilized by (i) sandwich-like π-stacking interactions between the planar aromatic ligand (1) and the Trp84 and Phe330 of the enzyme, (ii) an esteratic site anchoring with the amino side chain, and (iii) a hydrogen-bonding network. PMID:16989531

  13. Sampling of Ostreopsis cf. ovata using artificial substrates: Optimization of methods for the monitoring of benthic harmful algal blooms.

    PubMed

    Jauzein, Cécile; Fricke, Anna; Mangialajo, Luisa; Lemée, Rodolphe

    2016-06-15

    In the framework of monitoring of benthic harmful algal blooms (BHABs), the most commonly reported sampling strategy is based on the collection of macrophytes. However, this methodology has some inherent problems. A potential alternative method uses artificial substrates that collect resuspended benthic cells. The current study defines main improvements in this technique, through the use of fiberglass screens during a bloom of Ostreopsis cf. ovata. A novel set-up for the deployment of artificial substrates in the field was tested, using an easy clip-in system that helped restrain substrates perpendicular to the water flow. An experiment was run in order to compare the cell collection efficiency of different mesh sizes of fiberglass screens and results suggested an optimal porosity of 1-3mm. The present study goes further on showing artificial substrates, such as fiberglass screens, as efficient tools for the monitoring and mitigation of BHABs. PMID:27048690

  14. An integrated simultaneous distillation-extraction apparatus for the extraction of essential oils from herb materials and its application in Flos Magnoliae.

    PubMed

    Wei, Yuhui; Li, Boxia; Duan, Haogang; Wu, Xin'an; Yao, Xiaojun

    2010-03-01

    A large number of herb materials contain essential oils with extensive bioactivities. In this work, an integrated simultaneous distillation-extraction (ISDE) apparatus was developed. To demonstrate its feasibility, the performance of ISDE was evaluated for the extraction of essential oil from Flos Magnoliae and compared with conventional techniques including steam distillation (SD) and simultaneous distillation-extraction (SDE). According to the product yield, the time consumed and the composition of oil, the essential oils isolated by ISDE were better than that obtained by SD and similar to those obtained by SDE. ISDE was also better than SDE due to its simple operation and lower consumption of energy and organic solvent. PMID:19634121

  15. A diet supplemented with husks of Plantago ovata reduces the development of endothelial dysfunction, hypertension, and obesity by affecting adiponectin and TNF-alpha in obese Zucker rats.

    PubMed

    Galisteo, Milagros; Sánchez, Manuel; Vera, Rocío; González, Mercedes; Anguera, Anna; Duarte, Juan; Zarzuelo, Antonio

    2005-10-01

    The aim of the present study was to analyze whether consumption of a fiber-supplemented diet containing 3.5% Plantago ovata husks prevented many of the abnormalities clustered in the metabolic syndrome, including obesity, dyslipidemia, hypertension and endothelial dysfunction. For this purpose, obese Zucker rats, a model of type 2 diabetes, and their lean littermates were studied. Rats consumed a standard control diet or that diet supplemented with 3.5% P. ovata husks for 25 wk. Body weights were measured weekly. Systolic blood pressure (SBP) was measured monthly. At the end of the treatment, plasma concentrations of triglycerides, total cholesterol, FFAs, glucose, insulin, adiponectin, and tumor necrosis factor alpha (TNF-alpha) were determined, and studies on vascular function were performed using aortic rings. Rats fed the P. ovata husk-supplemented diet had a significantly reduced body weight gain compared with those fed the standard diet. Decreased endothelium-dependent relaxation in response to acetylcholine (ACh) by aortic rings from obese Zucker rats was improved in those fed the fiber-supplemented diet. The greater SBP, higher plasma concentrations of triglycerides, total cholesterol, FFA, glucose, insulin, and TNF-alpha, and the hypoadinectinemia that occurred in obese Zucker rats that consumed the control diet were significantly improved in those fed the fiber-supplemented diet. We conclude that intake of a P. ovata husk-supplemented diet prevents endothelial dysfunction, hypertension, and obesity development, and ameliorates dyslipidemia and abnormal plasma concentrations of adiponectin and TNF-alpha in obese Zucker rats. PMID:16177203

  16. Anxiolytic-like effects of obovatol isolated from Magnolia obovata: involvement of GABA/benzodiazepine receptors complex.

    PubMed

    Seo, Jeong-Ju; Lee, Seung-Ho; Lee, Yong-Su; Kwon, Byoung-Mok; Ma, Yuan; Hwang, Bang-Yeon; Hong, Jin-Tae; Oh, Ki-Wan

    2007-10-01

    This experiment was performed to investigate whether obovatol isolated from the leaves of Magnolia obovata has anxiolytic-like effects through GABA-benzodiazepine-receptors Cl(-) channel activation. The anxiolytic-like effects of obovatol in mice were examined using the elevated plus-maze and the automatic hole-board apparatus. Oral administration of obovatol (0.2, 0.5 and 1.0 mg/kg) significantly increased the number of open arm entries and the spent time on open arm in the elevated plus-maze test, compared with those of saline. Obovatol (0.2, 0.5 and 1.0 mg/kg) also produced anxiolytic-like effects, as reflected by an increase in head-dipping behaviors. These effects were comparable to those of diazepam (1.0 mg/kg), a well known anxiolytic drug. On the other hand, the anxiolytic-like effects of obovatol and diazepam were reversed by flumazenil, a benzodiazepine receptor antagonist, suggesting that the anxiolytic-like effects of obovatol were involved in GABA-benzodiazepine receptors complex. Obovatol was muscle relaxant by rota-rod test, but its effect was weaker than diazepam. Spontaneous locomotor activity also was inhibited by obovatol. Obovatol selectively increased the GABA(A) receptors alpha(1) subunit expression in amygdala of mouse brain. Obovatol also showed to bind to benzodiazepine receptors competitively in experiments using [(3)H]flunitrazepam in the cerebral cortex of mouse brain. Moreover, obovatol (10, 20 and 50 microM) increased Cl(-) influx and the increased Cl(-) influx was inhibited by flumazenil, in primary cultured neuronal cells and IMR-32 human neuroblastoma cells. These results suggest that obovatol has anxiolytic-like effects, and these pharmacological effects may be mediated by GABA-benzodiazepine receptors-activated Cl(-) channel opening. PMID:17698274

  17. Interaction of lipid bodies with other cell organelles in the maturing pollen of Magnolia x soulangeana (Magnoliaceae).

    PubMed

    Dinis, Augusto M; Coutinho, A Pereira

    2009-12-01

    The pollen grain maturation in Magnolia x soulangeana was studied ultrastructurally and cytochemically using both the light and transmission electron microscope. Emphasis was given on the storage lipid bodies of the vegetative cell (VC) and their interaction with other cell organelles. Stereological analysis of electron micrographs was performed to evaluate the variation in volume density (V(V)), surface density, and surface-to-volume ratio (S/V) of various cell organelles during pollen maturation. The size and numerical density of the lipid bodies, and their frequency of association with other cell organelles, were also determined. It was noted that during pollen ontogeny and maturation, the lipid bodies changed their pattern of distribution in the VC cytoplasm, which may be a good marker for the succeeding stages of pollen development. Also, the size, osmiophily, and V(V) of the lipid bodies were progressively reduced during pollen maturation whereas the S/V was significantly increased. This seems to indicate that the lipid bodies are mobilized in part during this period of pollen maturation. In particular, the intermediate and mature pollen showed a high percentage of lipid bodies establishing a physical contact with either glyoxysomes, either protein storage vacuoles, or small vesicles presumably originated from dictyosomes. This physical contact was found in both the chemically fixed and rapid freeze-fixed pollen indicating that it is neither artifactual nor casual. On the basis of this intimate association with other cell organelles and the morphometric analysis performed, we suggest that the mobilization of lipid bodies is likely mediated not only by glyoxysomes but also by other catabolic pathways involving the interaction of lipid bodies with either protein storage vacuoles or small Golgi vesicles. PMID:19763782

  18. Analysis of trace elements during different developmental stages of somatic embryogenesis in Plantago ovata Forssk using energy dispersive X-ray fluorescence.

    PubMed

    Saha, Priyanka; Raychaudhuri, Sarmistha Sen; Sudarshan, Mathummal; Chakraborty, Anindita

    2010-06-01

    Energy dispersive X-ray fluorescence (ED-XRF) technique has been used for the determination of trace element profile during different developmental stages of somatic embryogenic callus of an economically important medicinal plant, Plantago ovata Forssk. Somatic embryogenesis is a plant tissue culture-based technique, which is used for plant regeneration and crop improvement. In the present investigation, elemental content was analysed using ED-XRF technique during different developmental stages and also determine the effect of additives--casein hydrolysate and coconut water on the trace elemental profile of embryogenic callus tissue of P. ovata. Subsequent experiments showed significant alteration in the concentration of K, Ca, Mn, Fe, Zn, Cu, Br, and Sr in both the embryogenic and non-embryogenic callus. Higher K, Ca, Fe, Cu, and Zn accumulation was in embryogenic tissue stage compared to other stages, suggesting these elements are crucial for successful embryogenesis. The results suggest that this information could be useful for formulating a media for in vitro embryo induction of P. ovata. PMID:19696971

  19. Denitrification by Pseudomonas stutzeri coupled with CO2 reduction by Sporomusa ovata with hydrogen as an electron donor assisted by solid-phase humin.

    PubMed

    Xiao, Zhixing; Awata, Takanori; Zhang, Dongdong; Katayama, Arata

    2016-09-01

    A co-culture system comprising an acetogenic bacterium, Sporomusa ovata DSMZ2662, and a denitrifying bacterium, Pseudomonas stutzeri JCM20778, enabled denitrification using H2 as the sole external electron donor and CO2 as the sole external carbon source. Acetate produced by S. ovata supported the heterotrophic denitrification of P. stutzeri. A nitrogen balance study showed the reduction of nitrate to nitrogen gas without the accumulation of nitrite and nitrous oxide in the co-culture system. S. ovata did not show nitrate reduction to ammonium in the co-culture system. Significant proportions of the consumed H2 were utilized for denitrification: 79.9 ± 4.6% in the co-culture system containing solid-phase humin and 62.9±11.1% in the humin-free co-culture system. The higher utilization efficiency of hydrogen in the humin-containing system was attributed to the higher denitrification activity of P. stutzeri under the acetate deficient conditions. The nitrogen removal rate of the humin-containing co-culture system reached 0.19 kg NO3(-)-N·m(-3)·d(-1). Stable denitrification activity for 61 days of successive sub-culturing suggested the robustness of this co-culture system. This study provides a novel strategy for the in situ enhancement of microbial denitrification. PMID:26975755

  20. Successive electrical responses to insemination and concurrent sperm entries in the polyspermic egg of the ctenophore Beroe ovata.

    PubMed

    Goudeau, M; Goudeau, H

    1993-04-01

    In the ctenophore Beroe ovata, action potentials and sperm-induced egg electrical responses were recorded, in unfertilized and in vitro inseminated eggs, respectively. The unfertilized egg had a resting membrane potential of -65.6 +/- 1.3 mV and a membrane resistance of 1.45 +/- 0.09 M omega. When depolarized beyond a threshold of about -20 mV, the membrane displayed an action potential with a fast phase and then a peak reaching 38 +/- 0.6 mV, followed by a positive declining plateau which lasted about 20 sec and ended by a biphasic repolarization of the membrane. The action potential was mainly Ca(2+)-dependent and to a lesser extent, Na(+)-dependent. Upon one or several inseminations, monospermic eggs generated one fertilization potential and polyspermic eggs generated several sperm induced egg electrical responses. These sperm-induced egg electrical responses were composed of a voltage-gated action potential elicited by sperm-egg contact, resembling the action potential triggered by a depolarizing current, followed by a true sperm-gated depolarizing plateau which lasted about 60 sec and was mainly Na(+)-dependent. The number of electrical responses displayed by each egg corresponded to the number of male pronuclei detected in its cortex. An electrical response occurred for all egg membrane potentials ranging from -78 to +16 mV. In addition, the histogram giving the number of eggs in each class of egg characterized by a number of sperm entries indicated that each sperm entry constituted an independent process. However, when we compared the effectiveness of the in vitro inseminations during electrophysiological measurements and the in vivo inseminations under simulated natural conditions, the results showed two predominant classes of fertilized eggs, with one and two male pronuclei in the cortex respectively. Consequently, although our overall results exhibit features characteristic of polyspermy, they do not yet preclude the possibility that the eggs of the

  1. A novel method for extraction of a proteinous coagulant from Plantago ovata seeds for water treatment purposes.

    PubMed

    Ramavandi, Bahman; Hashemi, Seyedenayat; Kafaei, Raheleh

    2015-01-01

    Several chemicals have been applied in the process of coagulant extraction from herbal seeds, and the best extraction has been obtained in the presence of KCl or NaNO3[1-3], and NaCl [4]. However, the main challenge posed to these methods of coagulant extraction is their relatively low efficiency for water treatment purposes and the formation of dissolved organic matter during the treatment process. In these methods the salts, which have a one-valance metal (Na(+) and K(+)), are deposited in the internal structure and the pore of the coagulant, and may be useful for the coagulation/flocculation process. In this research, we found that modified methods produced more dense protein. Therefore, the modified procedure was better than the older one for removal of turbidity and harness from the contaminated water. Here we describe a method where: •According to the Hardy-Schulze rule, we applied the Fe(3+) ions instead of Na(+) and K(+) for the extraction of protein from Plantago ovata seeds.•The method was narrowed to extract protein by ethanol (defatting) and ammonium acetate and CM-Sepharose (protein extraction).•Two consecutive elutriations of crude extract was directly performed using 0.025-M FeCl3 and 0.05-M FeCl3 according to the basis of the ion-exchange processes. PMID:26150999

  2. Ovatoxin-a and Palytoxin Accumulation in Seafood in Relation to Ostreopsis cf. ovata Blooms on the French Mediterranean Coast

    PubMed Central

    Amzil, Zouher; Sibat, Manoella; Chomerat, Nicolas; Grossel, Hubert; Marco-Miralles, Francoise; Lemee, Rodolphe; Nezan, Elisabeth; Sechet, Veronique

    2012-01-01

    Dinoflagellates of the genus Ostreopsis are known to cause (often fatal) food poisoning in tropical coastal areas following the accumulation of palytoxin (PLTX) and/or its analogues (PLTX group) in crabs, sea urchins or fish. Ostreopsis spp. occurrence is presently increasing in the northern to north western Mediterranean Sea (Italy, Spain, Greece and France), probably in response to climate change. In France, Ostreopsis. cf. ovata has been associated with toxic events during summer 2006, at Morgiret, off the coast of Marseille, and a specific monitoring has been designed and implemented since 2007. Results from 2008 and 2009 showed that there is a real danger of human poisoning, as these demonstrated bioaccumulation of the PLTX group (PLTX and ovatoxin-a) in both filter-feeding bivalve molluscs (mussels) and herbivorous echinoderms (sea urchins). The total content accumulated in urchins reached 450 µg PLTX eq/kg total flesh (summer 2008). In mussels, the maximum was 230 µg eq PLTX/kg (summer 2009) compared with a maximum of 360 µg found in sea urchins during the same period at the same site. This publication brings together scientific knowledge obtained about the summer development of Ostreopsis spp. in France during 2007, 2008 and 2009. PMID:22412814

  3. Effect of Plantago ovata (psyllium) husk and seeds on sterol metabolism: studies in normal and ileostomy subjects.

    PubMed

    Gelissen, I C; Brodie, B; Eastwood, M A

    1994-02-01

    The diet of six normal and five ileostomy subjects was supplemented with 10 g/d Plantago ovata psyllium husk for 3 wk while six normal and four ileostomy subjects received 10 g/d psyllium seed. Fecal and ileostomy output, sterol excretion, serum cholesterol, and triglycerides were measured before and after supplementation. The husk had no effect on cholesterol or triglyceride concentrations in either normal or ileostomy subjects. Total and high-density-lipoprotein-cholesterol concentrations were reduced on average by 6.4% and 9.3%, respectively, in the normal group after seed supplementation. No effect on fecal bile acid excretion in the normal subjects was found after both regimes. Ileostomy bile acids were increased (on average 25%) after seed supplementation, whereas no effect on cholesterol concentrations was found. These results suggest that psyllium seed might be more effective than the husk in reducing serum cholesterol, that this cholesterol-lowering effect is not mediated by increased fecal bile acid losses, and increased ileal losses of bile acids might be compensated for by enhanced reabsorption in the colon. PMID:8310991

  4. A novel method for extraction of a proteinous coagulant from Plantago ovata seeds for water treatment purposes

    PubMed Central

    Ramavandi, Bahman; Hashemi, Seyedenayat; Kafaei, Raheleh

    2015-01-01

    Several chemicals have been applied in the process of coagulant extraction from herbal seeds, and the best extraction has been obtained in the presence of KCl or NaNO3[1], [2], [3], and NaCl [4]. However, the main challenge posed to these methods of coagulant extraction is their relatively low efficiency for water treatment purposes and the formation of dissolved organic matter during the treatment process. In these methods the salts, which have a one-valance metal (Na+ and K+), are deposited in the internal structure and the pore of the coagulant, and may be useful for the coagulation/flocculation process. In this research, we found that modified methods produced more dense protein. Therefore, the modified procedure was better than the older one for removal of turbidity and harness from the contaminated water. Here we describe a method where: • According to the Hardy–Schulze rule, we applied the Fe3+ ions instead of Na+ and K+ for the extraction of protein from Plantago ovata seeds. • The method was narrowed to extract protein by ethanol (defatting) and ammonium acetate and CM-Sepharose (protein extraction). • Two consecutive elutriations of crude extract was directly performed using 0.025-M FeCl3 and 0.05-M FeCl3 according to the basis of the ion-exchange processes. PMID:26150999

  5. Honokiol Dimers and Magnolol Derivatives with New Carbon Skeletons from the Roots of Magnolia officinalis and Their Inhibitory Effects on Superoxide Anion Generation and Elastase Release

    PubMed Central

    Chen, Hung-Chung; Kuo, Ping-Chung; Lee, E-Jian; Lee, Kuo-Hsiung; Wu, Tian-Shung

    2013-01-01

    Two honokiol dimers, houpulins A and B (1 and 2), and two magnolol derivatives, houpulins C and D (3 and 4), were isolated and characterized from an ethanol extract obtained from the roots of Magnolia officinalis. The chemical structures were determined based on spectroscopic and physicochemical analyses, which included 1D and 2D NMR, as well as mass spectrometry data. These four oligomers possess new carbon skeletons postulated to be biosynthesized from the coupling of three or four C6-C3 subunits. In addition, the new oligomers were evaluated for inhibition of superoxide anion generation and elastase release, and houpulin B (2) was identified as a new anti-inflammatory lead compound. PMID:23667420

  6. Magnolia Bioactive Constituent 4-O-Methylhonokiol Prevents the Impairment of Cardiac Insulin Signaling and the Cardiac Pathogenesis in High-Fat Diet-Induced Obese Mice

    PubMed Central

    Zhang, Zhiguo; Chen, Jing; Zhou, Shanshan; Wang, Shudong; Cai, Xiaohong; Conklin, Daniel J.; Kim, Ki-Soo; Kim, Ki Ho; Tan, Yi; Zheng, Yang; Kim, Young Heui; Cai, Lu

    2015-01-01

    In obesity, cardiac insulin resistance is a putative cause of cardiac hypertrophy and dysfunction. In our previous study, we observed that Magnolia extract BL153 attenuated high-fat-diet (HFD)-induced cardiac pathogenic changes. In this study, we further investigated the protective effects of the BL153 bioactive constituent, 4-O-methylhonokiol (MH), against HFD-induced cardiac pathogenesis and its possible mechanisms. C57BL/6J mice were fed a normal diet or a HFD with gavage administration of vehicle, BL153, or MH (low or high dose) daily for 24 weeks. Treatment with MH attenuated HFD-induced obesity, as evidenced by body weight gain, and cardiac pathogenesis, as assessed by the heart weight and echocardiography. Mechanistically, MH treatment significantly reduced HFD-induced impairment of cardiac insulin signaling by preferentially augmenting Akt2 signaling. MH also inhibited cardiac expression of the inflammatory factors tumor necrosis factor-α and plasminogen activator inhibitor-1 and increased the phosphorylation of nuclear factor erythroid-derived 2-like 2 (Nrf2) as well as the expression of a Nrf2 downstream target gene heme oxygenase-1. The increased Nrf2 signaling was associated with decreased oxidative stress and damage, as reflected by lowered malondialdehyde and 3-nitrotyrosine levels. Furthermore, MH reduced HFD-induced cardiac lipid accumulation along with lowering expression of cardiac fatty acid translocase/CD36 protein. These results suggest that MH, a bioactive constituent of Magnolia, prevents HFD-induced cardiac pathogenesis by attenuating the impairment of cardiac insulin signaling, perhaps via activation of Nrf2 and Akt2 signaling to attenuate CD36-mediated lipid accumulation and lipotoxicity. PMID:26157343

  7. DNA sequences from Miocene fossils: an ndhF sequence of Magnolia latahensis (Magnoliaceae) and an rbcL sequence of Persea pseudocarolinensis (Lauraceae).

    PubMed

    Kim, Sangtae; Soltis, Douglas E; Soltis, Pamela S; Suh, Youngbae

    2004-04-01

    We report a partial ndhF sequence (1528 bp) of Magnolia latahensis and a partial rbcL sequence (699 bp) of Persea pseudocarolinensis from the Clarkia fossil beds of Idaho, USA (Miocene; 17-20 million years [my] BP). The ndhF sequence from M. latahensis was identical to those of extant M. grandiflora, M. schiediana, M. guatemalensis, and M. tamaulipana. Parsimony analysis of the ndhF sequence of M. latahensis and previously reported ndhF sequences for Magnoliaceae placed M. latahensis within Magnolia as a member of the Theorhodon clade. This result is reasonable considering that: (1) the morphology of M. latahensis is very similar to that of extant M. grandiflora, and (2) a recent molecular phylogenetic study of Magnoliaceae showed that the maximum sequence divergence of ndhF among extant species is very low (1.05% in subfamily Magnolioideae) compared with other angiosperm families. We reanalyzed the previously reported rbcL sequence of M. latahensis with sequences for all major lineages of extant Magnoliales and Laurales. This sequence is sister to Liriodendron, rather than grouped with a close relative of M. grandiflora as predicted by morphology and the results of the ndhF analysis, possibly due to a few erroneous base calls in the sequences. The rbcL sequence of P. pseudocarolinensis differed from rbcL of extant Persea species by 3-6 nucleotides and from rbcL of extant Sassafras albidum by two nucleotides. Phylogenetic analyses of rbcL sequences for all major lineages of Magnoliales and Laurales placed the fossil P. pseudocarolinensis within Lauraceae and as sister to S. albidum. These results reinforce the suggestion that Clarkia and other similar sites hold untapped potential for molecular analysis of fossils. PMID:21653417

  8. The protective effects of total phenols in magnolia officinalix rehd. et wils on gastrointestinal tract dysmotility is mainly based on its influence on interstitial cells of cajal

    PubMed Central

    Tian, Hui; Huang, Dazhi; Li, Tao; Huang, Lihua; Zheng, Xingguang; Tang, Danxia; Zhang, Lu; Wang, Jian

    2015-01-01

    Magnolia officinalix Rehd. et Wils is a kind of herb which is widely used for gastrointestinal tract mobility disorder in Asian countries. In this study, we investigated whether the total phenols of Magnolia officinalix Rehd. et Wils (TPM) treatment improves gastrointestinal tract dysmobility induced by intraperitoneal injection of atropine (5 mg/kg) in rats. Rats were randomly grouped into three units: TPM-pretreated/atropine-treated group, atropinetreated group and control group. TPM were administrated for 7 days. Gastric residual rate and intestinal transit were measured 20 min after atropine injected, and gastrointestinal hormones (including: gastrin (GAS), motilin (MTL), somatostatin (SS) and p substance (PS) levels in serum were also measured by ELISA kits. The number and distribution of interstitial cells of Cajal (ICCs) in stomach were detected by immunohistochemistry analysis, while c-kit and stem cell factor (SCF) expressions in stomach were also measured by western blotting. We found that TPM pretreatment significantly improved atropine-induced gastric residual rate increase, while had no significantly effects on intestinal transit; it also significantly normalized GAS, MTL and PS serum levels. Atropine-induced ICCs numbers decreased in both sinuses ventriculi and body of stomach, which is improved by TPM pretreatment. Western blotting results showed the expressions of c-kit and SCF were down-regulated after atropine injection, which can be reversed with TPM pretreatment. These results above indicates that TPM treatment can significantly protected atropine-induced gastric dysmoblility, which may owed to its regulation on c-kit/SCF signing pathway. PMID:26884941

  9. Magnolia bioactive constituent 4-O-methylhonokiol prevents the impairment of cardiac insulin signaling and the cardiac pathogenesis in high-fat diet-induced obese mice.

    PubMed

    Zhang, Zhiguo; Chen, Jing; Zhou, Shanshan; Wang, Shudong; Cai, Xiaohong; Conklin, Daniel J; Kim, Ki-Soo; Kim, Ki Ho; Tan, Yi; Zheng, Yang; Kim, Young Heui; Cai, Lu

    2015-01-01

    In obesity, cardiac insulin resistance is a putative cause of cardiac hypertrophy and dysfunction. In our previous study, we observed that Magnolia extract BL153 attenuated high-fat-diet (HFD)-induced cardiac pathogenic changes. In this study, we further investigated the protective effects of the BL153 bioactive constituent, 4-O-methylhonokiol (MH), against HFD-induced cardiac pathogenesis and its possible mechanisms. C57BL/6J mice were fed a normal diet or a HFD with gavage administration of vehicle, BL153, or MH (low or high dose) daily for 24 weeks. Treatment with MH attenuated HFD-induced obesity, as evidenced by body weight gain, and cardiac pathogenesis, as assessed by the heart weight and echocardiography. Mechanistically, MH treatment significantly reduced HFD-induced impairment of cardiac insulin signaling by preferentially augmenting Akt2 signaling. MH also inhibited cardiac expression of the inflammatory factors tumor necrosis factor-α and plasminogen activator inhibitor-1 and increased the phosphorylation of nuclear factor erythroid-derived 2-like 2 (Nrf2) as well as the expression of a Nrf2 downstream target gene heme oxygenase-1. The increased Nrf2 signaling was associated with decreased oxidative stress and damage, as reflected by lowered malondialdehyde and 3-nitrotyrosine levels. Furthermore, MH reduced HFD-induced cardiac lipid accumulation along with lowering expression of cardiac fatty acid translocase/CD36 protein. These results suggest that MH, a bioactive constituent of Magnolia, prevents HFD-induced cardiac pathogenesis by attenuating the impairment of cardiac insulin signaling, perhaps via activation of Nrf2 and Akt2 signaling to attenuate CD36-mediated lipid accumulation and lipotoxicity. PMID:26157343

  10. Polymorphisms in LEP and NPY genes modify the response to soluble fibre Plantago ovata husk intake on cardiovascular risk biomarkers.

    PubMed

    Crescenti, Anna; Solà, Rosa; Valls, Rosa M; Anguera, Anna; Arola, Lluís

    2013-01-01

    The satiating effect of fibre consumption has been related to gut hormones, such as peptide YY and leptin. These peptides may also influence cardiovascular (CVD) risk biomarkers. Nevertheless, there is wide interindividual variation in metabolic responses to fibre consumption. The objective was to investigate differences in the effects of soluble fibre, in the form of Plantago ovata husk (Po-husk) treatment, on CVD risk biomarkers according to selected polymorphisms in genes related to satiety. The study was a multi-centred, double-blind, placebo-controlled, parallel and randomised trial in mild-moderate hypercholesterolaemic patients (age range: 43-67 years). Eight polymorphisms in three genes related to satiety (LEP, NPY and PYY) were identified in 178 participants; 88 patients in the placebo (microcrystalline cellulose 14 g/day) group and 90 in the Po-husk (14 g/day) group, which had added to a low-saturated-fat diet for 8 weeks. The CVD biomarkers measured included the following: lipid profile, blood pressure (BP), glucose, insulin, hs-CRP, oxidised LDL and IL-6. Relative to the placebo, Po-husk consumption lowered the plasma total cholesterol concentration by 3.3 % according to rs7799039 polymorphism in the LEP gene (p < 0.05). Furthermore, the Po-husk reduced systolic BP (mean [95 % CI]) by -8 mmHg (-14.16; -1.90) and hs-CRP by 24.9 % in subjects with the AA genotype of the rs16147 polymorphism in the NPY gene (32 % of our total population; p < 0.05), which remained significant after Bonferroni correction. In conclusion, polymorphisms in the LEP and NPY genes potentiate the response to Po-husk, particularly the effects on systolic BP and the hs-CRP plasma concentration. PMID:22669627

  11. Discovery, Prevalence, and Persistence of Novel Circular Single-Stranded DNA Viruses in the Ctenophores Mnemiopsis leidyi and Beroe ovata.

    PubMed

    Breitbart, Mya; Benner, Bayleigh E; Jernigan, Parker E; Rosario, Karyna; Birsa, Laura M; Harbeitner, Rachel C; Fulford, Sidney; Graham, Carina; Walters, Anna; Goldsmith, Dawn B; Berger, Stella A; Nejstgaard, Jens C

    2015-01-01

    Gelatinous zooplankton, such as ctenophores and jellyfish, are important components of marine and brackish ecosystems and play critical roles in aquatic biogeochemistry. As voracious predators of plankton, ctenophores have key positions in aquatic food webs and are often successful invaders when introduced to new areas. Gelatinous zooplankton have strong impacts on ecosystem services, particularly in coastal environments. However, little is known about the factors responsible for regulating population dynamics of gelatinous organisms, including biological interactions that may contribute to bloom demise. Ctenophores are known to contain specific bacterial communities and a variety of invertebrate parasites and symbionts; however, no previous studies have examined the presence of viruses in these organisms. Building upon recent studies demonstrating a diversity of single-stranded DNA viruses that encode a replication initiator protein (Rep) in aquatic invertebrates, this study explored the presence of circular, Rep-encoding single-stranded DNA (CRESS-DNA) viruses in the ctenophores Mnemiopsis leidyi and Beroe ovata collected from the Skidaway River Estuary and Savannah River in Georgia, USA. Using rolling circle amplification followed by restriction enzyme digestion, this study provides the first evidence of viruses in ctenophores. Investigation of four CRESS-DNA viruses over an 8-month period using PCR demonstrated temporal trends in viral prevalence and indicated that some of the viruses may persist in ctenophore populations throughout the year. Although future work needs to examine the ecological roles of these ctenophore-associated viruses, this study indicates that viral infection may play a role in population dynamics of gelatinous zooplankton. PMID:26733971

  12. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk).

    PubMed

    Patel, Manish K; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid CPS (57%) and ω-6 linoleic acid CPS (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  13. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk)

    PubMed Central

    Patel, Manish K.; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid (57%) and ω-6 linoleic acid (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  14. The seeds from Plantago ovata lower plasma lipids by altering hepatic and bile acid metabolism in guinea pigs.

    PubMed

    Romero, Ana Lourdes; West, Kristy L; Zern, Tosca; Fernandez, Maria Luz

    2002-06-01

    Psyllium, the husks from Plantago ovata (PO), is recognized as a potent agent in lowering plasma cholesterol. In this study, we tested the potential hypolipidemic effects of the seeds from PO and the mechanisms associated with the lowering of plasma lipids. Male Hartley guinea pigs (n = 30; 10 per group) were fed either a control diet or diets containing 7.5 or 10 g/100 g PO for 4 wk. Diets were identical in composition except for the fiber source. The control diet contained 10 g/100 g cellulose and 2.5 g/100 g guar gum, whereas the PO diets were adjusted to a total of 12.5 g/100 g fiber with cellulose. Although a dose response was not observed, plasma triglycerides and LDL cholesterol were 34 and 23% lower in the PO groups compared with the control (P < 0.01). Lecithin cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) activities were significantly affected by the PO diets. The control group had 100 and 36% higher LCAT and CETP (P < 0.01) activities, respectively, compared with the PO groups. Hepatic total and free cholesterol concentrations were not affected by PO, but cholesteryl ester concentrations were 50% (P < 0.01) lower in the PO groups compared with the control. The activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme of cholesterol synthesis was up-regulated in the PO groups by 37%. Similarly, the activity of cholesterol 7alpha-hydroxylase, the regulatory enzyme of cholesterol catabolism to bile acids was 33% higher in the PO groups (P < 0.02). Fecal bile acids were 3 times higher in the PO groups than in the control group. These results suggest that PO exerts its hypolipidemic effect by affecting bile acid absorption and altering hepatic cholesterol metabolism. PMID:12042433

  15. Discovery, Prevalence, and Persistence of Novel Circular Single-Stranded DNA Viruses in the Ctenophores Mnemiopsis leidyi and Beroe ovata

    PubMed Central

    Breitbart, Mya; Benner, Bayleigh E.; Jernigan, Parker E.; Rosario, Karyna; Birsa, Laura M.; Harbeitner, Rachel C.; Fulford, Sidney; Graham, Carina; Walters, Anna; Goldsmith, Dawn B.; Berger, Stella A.; Nejstgaard, Jens C.

    2015-01-01

    Gelatinous zooplankton, such as ctenophores and jellyfish, are important components of marine and brackish ecosystems and play critical roles in aquatic biogeochemistry. As voracious predators of plankton, ctenophores have key positions in aquatic food webs and are often successful invaders when introduced to new areas. Gelatinous zooplankton have strong impacts on ecosystem services, particularly in coastal environments. However, little is known about the factors responsible for regulating population dynamics of gelatinous organisms, including biological interactions that may contribute to bloom demise. Ctenophores are known to contain specific bacterial communities and a variety of invertebrate parasites and symbionts; however, no previous studies have examined the presence of viruses in these organisms. Building upon recent studies demonstrating a diversity of single-stranded DNA viruses that encode a replication initiator protein (Rep) in aquatic invertebrates, this study explored the presence of circular, Rep-encoding single-stranded DNA (CRESS-DNA) viruses in the ctenophores Mnemiopsis leidyi and Beroe ovata collected from the Skidaway River Estuary and Savannah River in Georgia, USA. Using rolling circle amplification followed by restriction enzyme digestion, this study provides the first evidence of viruses in ctenophores. Investigation of four CRESS-DNA viruses over an 8-month period using PCR demonstrated temporal trends in viral prevalence and indicated that some of the viruses may persist in ctenophore populations throughout the year. Although future work needs to examine the ecological roles of these ctenophore-associated viruses, this study indicates that viral infection may play a role in population dynamics of gelatinous zooplankton. PMID:26733971

  16. Corrinoid-Dependent Methyl Transfer Reactions Are Involved in Methanol and 3,4-Dimethoxybenzoate Metabolism by Sporomusa ovata

    PubMed Central

    Stupperich, Erhard; Konle, Ralph

    1993-01-01

    Washed and air-oxidized proteins from Sporomusa ovata cleaved the C-O bond of methanol or methoxyaromatics and transferred the methyl to dl-tetrahydrofolate. The reactions strictly required a reductive activation by titanium citrate, catalytic amounts of ATP, and the addition of dl-tetrahydrofolate. Methylcorrinoid-containing proteins carried the methanol methyl, which was transferred to dl-tetrahydrofolate at a specific rate of 120 nmol h-1 mg of protein-1. Tetrahydrofolate methylation diminished after the addition of 1-iodopropane or when the methyl donor methanol was replaced by 3,4-dimethoxybenzoate. However, whole Sporomusa cells utilize the methoxyl groups of 3,4-dimethoxybenzoate as a carbon source by a sequential O demethylation to 4-hydroxy-3-methoxybenzoate and 3,4-dihydroxybenzoate. The in vitro O demethylation of 3,4-[4-methoxyl-14C]dimethoxybenzoate proceeded via two distinct corrinoid-containing proteins to form 5-[14C]methyltetrahydrofolate at a specific rate of 200 nmol h-1 mg of protein-1. Proteins from 3,4-dimethoxybenzoate-grown cells efficiently used methoxybenzoates with vicinal substituents only, but they were unable to activate methanol. These results emphasized that specific enzymes are involved in methanol activation as well as in the activation of various methoxybenzoates and that similar corrinoid-dependent methyl transfer pathways are employed in 5-methyl-tetrahydrofolate formation from these substrates. Methyl-tetrahydrofolate could be demethylated by a distinct methyl transferase. That enzyme activity was present in washed and air-oxidized cell extracts from methanol-grown cells and from 3,4-dimethoxybenzoate-grown cells. It used cob(I)alamin as the methyl acceptor in vitro, which was methylated at a rate of 48 nmol min-1 mg of protein-1 even when ATP was omitted from the assay mixture. This methyl-cob(III)alamin formation made possible a spectrophotometric quantification of the preceding methyl transfers from methanol or

  17. Impact of bio-fertilizers and different levels of cadmium on the growth, biochemical contents and lipid peroxidation of Plantago ovata Forsk.

    PubMed

    Haneef, Irfana; Faizan, Shahla; Perveen, Rubina; Kausar, Saima

    2014-09-01

    Plantago ovata Forsk. (isabgol) is a valuable medicinal plant; its seeds and shell have a significant role in pharmacy as a laxative compound. Increasing soil contamination with cadmium (Cd) is one of the major concerns and is responsible for toxic effects in plants. This investigation was aimed to analyze the role of biofertilizers in alleviation of cadmium stress, given at the rate of 0, 50, and 100 mg kg(-1) of soil. The plants of isabgol, were grown in pots with and without application of AM fungi and Azotobacter (alone and combination). Cadmium showed negative effect on growth and biochemical component whereas proline and MDA content increase with increasing cadmium concentration. Addition of bio-fertilizer showed better growth and higher pigment concentration under cadmium stress as compared to the control. The dual inoculation of AM fungi and Azotobacter was found to be the best in reduction of cadmium stress and promotion of growth parameters. PMID:25183940

  18. Impact of bio-fertilizers and different levels of cadmium on the growth, biochemical contents and lipid peroxidation of Plantago ovata Forsk

    PubMed Central

    Haneef, Irfana; Faizan, Shahla; Perveen, Rubina; Kausar, Saima

    2014-01-01

    Plantago ovata Forsk. (isabgol) is a valuable medicinal plant; its seeds and shell have a significant role in pharmacy as a laxative compound. Increasing soil contamination with cadmium (Cd) is one of the major concerns and is responsible for toxic effects in plants. This investigation was aimed to analyze the role of biofertilizers in alleviation of cadmium stress, given at the rate of 0, 50, and 100 mg kg−1 of soil. The plants of isabgol, were grown in pots with and without application of AM fungi and Azotobacter (alone and combination). Cadmium showed negative effect on growth and biochemical component whereas proline and MDA content increase with increasing cadmium concentration. Addition of bio-fertilizer showed better growth and higher pigment concentration under cadmium stress as compared to the control. The dual inoculation of AM fungi and Azotobacter was found to be the best in reduction of cadmium stress and promotion of growth parameters. PMID:25183940

  19. Diversity of corrinoids in acetogenic bacteria. P-cresolylcobamide from Sporomusa ovata, 5-methoxy-6-methylbenzimidazolylcobamide from Clostridium formicoaceticum and vitamin B12 from Acetobacterium woodii.

    PubMed

    Stupperich, E; Eisinger, H J; Kräutler, B

    1988-03-01

    The Co beta-cyanocobamides obtained by cyanide extractions from several acetogenic bacteria were structurally characterized by ultraviolet/visible spectra, proton-nuclear-magnetic-resonance spectra and fast-atom-bombardment mass spectra. p-Cresolycobamide was detected as a major corrinoid from Sporomusa ovata. This 'complete' corrinoid was isolated from an organism for the first time. Instead of the common Co alpha bases of the known and biologically active cobamides, p-cresolylcobamide contained a glycosidically bound cresolyl function that was unable to coordinate to the cobalt of the corrin ring. An additional, previously unknown corrinoid from natural sources, Co alpha-[alpha-(5-methoxy-6-methylbenzimidazolyl)]-Co beta-cyanocobamide, was isolated along with vitamin B12 from Clostridium formicoaceticum. Both homoacetogenic eubacteria were grown on methanol and contained high amounts of corrinoids (greater than 950 nmol/g cell dry mass). Less corrinoid was isolated from Acetobacterium woodii and characterized as vitamin B12. PMID:3350008

  20. EDRF (endothelium-derived relaxing factor)-release and Ca sup ++ -channel blockage by Magnolol, an antiplatelet agent isolated from Chinese herb Magnolia officinalis, in rat thoracic aorta

    SciTech Connect

    Teng, Cheming; Yu, Sheumeei; Chen, Chienchih; Huang, Yulin; Huang, Turfu National Research Institute of Chinese Medicine, Taipei )

    1990-01-01

    Magnolol is an antiplatelet agent isolated from Chinese herb Magnolia officinalis. It inhibited norepinephrine-induced phasic and tonic contractions in rat thoracic aorta. At the plateau of the NE-induced tonic contraction, addition of magnolol caused two phases (fast and slow) of relaxation. These two relaxations were concentration-dependent, and were not inhibited by indomethacin. The fast relaxation was completely antagonized by hemoglobin and methylene blue, and disappeared in de-endothelialized aorta while the slow relaxation was not affected by the above treatments. Magnolol also inhibited high potassium-induced, calcium-dependent contraction of rat aorta in a concentration-dependent manner. {sup 45}Ca{sup ++} influx induced by high potassium or NE was markedly inhibited by magnolol. Cyclic GMP, but not PGI{sub 2}, was increased by magnolol in intact, but not in de-endothelialized aorta. It is concluded that magnolol relaxed vascular smooth muscle by releasing endothelium-derived relaxing factor (EDRF) and by inhibiting calcium influx through voltage-gated calcium channels.

  1. Chemical compositions and antimicrobial and antioxidant activities of the essential oils from Magnolia grandiflora, Chrysactinia mexicana, and Schinus molle found in northeast Mexico.

    PubMed

    Guerra-Boone, Laura; Alvarez-Román, Rocío; Salazar-Aranda, Ricardo; Torres-Cirio, Anabel; Rivas-Galindo, Verónica Mayela; Waksman de Torres, Noemí; González González, Gloria María; Pérez-López, Luis Alejandro

    2013-01-01

    The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL). PMID:23472479

  2. Quality evaluation of the leaves of Magnolia officinalis var. biloba using high-performance liquid chromatography fingerprint analysis of phenolic compounds.

    PubMed

    Yi, Jun; Wu, Jian-Guo; Wu, Jin-Yu; Wu, Yan-Bin

    2016-02-01

    The high-performance liquid chromatography fingerprint method is a simple and reliable technique to evaluate the quality of leaves of Magnolia officinalis Rehd.et Wils. var. biloba Rehd.et Wils. We used the following bioactive phenolic constituents as reference compounds: rutin, afzelin, hyperoside, isoquercitrin, quercetin-3-O-α-l-rhamnoside, honokiol and magnolol. The conditions of an Agilent 1200 HPLC were: YMC-Pack-ODS-AQ column (250 × 4.6 mm id S-5 μm, 12 nm), mobile phase acetonitrile and 0.2% phosphoric acid in a gradient elute mode, flow rate 1.0 mL/min, detection wavelength 280 nm and column temperature 30°C. The analytical method was validated in terms of linearity, stability, repeatability, precision and recovery tests. While performing fingerprint analysis, we identified 11 peaks as characteristic peaks and assessed the similarities of 17 samples collected from different geological regions of China. The peak areas were used to evaluate the variation in the chemical composition of the tested samples. For this purpose, we performed hierarchical cluster analysis of the peak areas. Our results indicate that simultaneous determination of multiple ingredients could be done through chromatographic fingerprint analysis. Therefore, this high-performance liquid chromatography fingerprint method was readily utilized to evaluate the quality of leaves of M. officinalis var.biloba, which are used in several traditional herbal preparations. PMID:26681396

  3. Pollen flow and effects of population structure on selfing rates and female and male reproductive success in fragmented Magnolia stellata populations

    PubMed Central

    2013-01-01

    Background Fragmentation of plant populations may affect mating patterns and female and male reproductive success. To improve understanding of fragmentation effects on plant reproduction, we investigated the pollen flow patterns in six adjacent local populations of Magnolia stellata, an insect-pollinated, threatened tree species in Japan, and assessed effects of maternal plant (genet) size, local genet density, population size and neighboring population size on female reproductive success (seed production rates), and effects of mating distance, paternal genet size, population size and separation of populations on male reproductive success. Results The seed production rate, i.e. the proportion of ovules that successfully turned into seeds, varied between 1.0 and 6.5%, and increased with increasing population size and neighboring population size, and with decreasing maternal genet size and local genet density. The selfing rate varied between 3.6 and 28.9%, and increased with increasing maternal genet size and with declining local genet density. Male reproductive success increased with increasing paternal genet size, and decreased with increasing mating distance and separation of population. Pollen flow between the populations was low (6.1%) and highly leptocurtic. Conclusions Our results indicate that habitat fragmentation, separation and reduced size of populations, affected mating patterns and reproductive success of M. stellata. Local competition for pollinators and plant display size were likely to alter the reproductive success. PMID:23517612

  4. Honokiol, a phytochemical from the Magnolia plant, inhibits photocarcinogenesis by targeting UVB-induced inflammatory mediators and cell cycle regulators: development of topical formulation.

    PubMed

    Vaid, Mudit; Sharma, Som D; Katiyar, Santosh K

    2010-11-01

    To develop newer and more effective chemopreventive agents for skin cancer, we assessed the effect of honokiol, a phytochemical from the Magnolia plant, on ultraviolet (UV) radiation-induced skin tumorigenesis using the SKH-1 hairless mouse model. Topical treatment of mice with honokiol in a hydrophilic cream-based topical formulation before or after UVB (180 mJ/cm(2)) irradiation resulted in a significant protection against photocarcinogenesis in terms of tumor multiplicity (28-60%, P < 0.05 to <0.001) and tumor volume per tumor-bearing mouse (33-80%, P < 0.05 to 0.001, n = 20). Honokiol also inhibited and delayed the malignant progression of papillomas to carcinomas. To investigate the in vivo molecular targets of honokiol efficacy, tumors and tumor-uninvolved skin samples from the tumor-bearing mice were analyzed for inflammatory mediators, cell cycle regulators and survival signals using immunostaining, western blotting and enzyme-linked immunosorbent assay. Treatment with honokiol significantly inhibited UVB-induced expression of cyclooxygenase-2, prostaglandin E(2) (P < 0.001), proliferating cell nuclear antigen and proinflammatory cytokines, such as tumor necrosis factor-α (P < 0.001), interleukin (IL)-1β (P < 0.01) and IL-6 (P < 0.001) in the skin as well as in skin tumors. Western blot analysis revealed that honokiol: (i) inhibited the levels of cyclins D1, D2 and E and associated cyclin-dependent kinases (CDKs)2, CDK4 and CDK6, (ii) upregulated Cip/p21 and Kip/p27 and (iii) inhibited the levels of phosphatidylinositol 3-kinase and the phosphorylation of Akt at Ser(473) in UVB-induced skin tumors. Together, our results indicate that honokiol holds promise for the prevention of UVB-induced skin cancer by targeting inflammatory mediators, cell cycle regulators and cell survival signals in UVB-exposed skin. PMID:20823108

  5. Capparis ovata treatment suppresses inflammatory cytokine expression and ameliorates experimental allergic encephalomyelitis model of multiple sclerosis in C57BL/6 mice.

    PubMed

    Ozgun-Acar, Ozden; Celik-Turgut, Gurbet; Gazioglu, Isil; Kolak, Ufuk; Ozbal, Seda; Ergur, Bekir U; Arslan, Sevki; Sen, Alaattin; Topcu, Gulacti

    2016-09-15

    Since ancient times, Capparis species have been widely used in traditional medicine to treat various diseases. Our recent investigations have suggested Capparis ovata's potential anti-neuroinflammatory application for the treatment of multiple sclerosis (MS). The present study was designed to precisely determine the underlying mechanism of its anti-neuroinflammatory effect in a mouse model of MS. C. ovata water extract (COWE) was prepared using the plant's fruit, buds, and flower parts (Turkish Patent Institute, PT 2012/04,093). We immunized female C57BL/6J mice with MOG35-55/CFA. COWE was administered at a daily dose of 500mg/kg by oral gavage either from the day of immunization (T1) or at disease onset (T2) for 21days. Gene expression analysis was performed using a Mouse Multiple Sclerosis RT² Profiler PCR Array, and further determinations and validations of the identified genes were performed using qPCR. Whole-genome transcriptome profiling was analyzed using Agilent SurePrint G3 Mouse GE 8X60K microarrays. Immunohistochemical staining was applied to brain sections of the control and treated mice to examine the degree of degeneration. COWE was further fractionated and analyzed phytochemically using the Zivak Tandem Gold Triple Quadrupole LC/MS-MS system. COWE remarkably suppressed the development of EAE in T1, and the disease activity was completely inhibited. In the T2 group, the maximal score was significantly reduced compared with that of the parallel EAE group. The COWE suppression of EAE was associated with a significantly decreased expression of genes that are important in inflammatory signaling, such as TNFα, IL6, NF-κB, CCL5, CXCL9, and CXCK10. On the other hand, the expression of genes involved in myelination/remyelination was significantly increased. Immunohistochemical analysis further supported these effects, showing that the number of infiltrating immune cells was decreased in the brains of COWE-treated animals. In addition, differential

  6. Plantago ovata F. Mucilage-Alginate Mucoadhesive Beads for Controlled Release of Glibenclamide: Development, Optimization, and In Vitro-In Vivo Evaluation.

    PubMed

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2013-01-01

    The current study deals with the development and optimization of ispaghula (Plantago ovata F.) husk mucilage- (IHM-) alginate mucoadhesive beads containing glibenclamide by ionotropic gelation technique. The effects of sodium alginate (SA) to IHM and cross-linker (CaCl2) concentration on the drug encapsulation efficiency (DEE, %), as well as cumulative drug release after 10 hours (R10 h, %), were optimized using 3(2) factorial design based on response surface methodology. The observed responses were coincided well with the predicted values by the experimental design. The optimized mucoadhesive beads exhibited 94.43 ± 4.80% w/w of DEE and good mucoadhesivity with the biological membrane in wash-off test and sustained drug release profile over 10 hours. The beads were also characterized by SEM and FTIR analyses. The in vitro drug release from these beads was followed by controlled release (zero-order) pattern with super case-II transport mechanism. The optimized glibenclamide-loaded IHM-alginate mucoadhesive beads showed significant antidiabetic effect in alloxan-induced diabetic rats over prolonged period after oral administration. PMID:26555967

  7. Ispaghula (Plantago ovata) seed husk polysaccharides promote proliferation of human epithelial cells (skin keratinocytes and fibroblasts) via enhanced growth factor receptors and energy production.

    PubMed

    Deters, A M; Schröder, K R; Smiatek, T; Hensel, Andreas

    2005-01-01

    Endogenous carbohydrates, especially oligo- and polysaccharides, participate in the regulation of a broad range of biological activities, e. g., signal transduction, inflammation, fertilisation, cell-cell-adhesion and act as in vivo markers for the determination of cell types. In the present study, water-soluble (WS) and gel-forming polysaccharides (GF) of ispaghula seed husk (Plantago ovata Forsskal, Plantaginaceae) were characterised as neutral and acidic arabinoxylans and tested under in vitro conditions for regulating activities on cell physiology of human keratinocytes and human primary fibroblasts. Only water-soluble polysaccharides exhibited strong and significant effects on cell physiology of keratinocytes and fibroblasts. Proliferation of cells of the spontaneously immortalised keratinocyte cell line HaCaT was significantly up-regulated in a dose-independent manner. Analysis of activated signal pathways by RNA analysis proved an effect of the acidic arabinoxylan on the expression of keratinocyte growth factor (KGF) in HaCaT cells. Differentiation behaviour of normal human keratinocytes (NHK) determined by involucrin was slightly influenced, due to the enhanced cell proliferation, leading to a cell-cell-mediated indirect induction of early differentiation. WS did not influence late differentiation, as determined by keratin K1 and K10 titres. PMID:15678371

  8. Plantago ovata F. Mucilage-Alginate Mucoadhesive Beads for Controlled Release of Glibenclamide: Development, Optimization, and In Vitro-In Vivo Evaluation

    PubMed Central

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2013-01-01

    The current study deals with the development and optimization of ispaghula (Plantago ovata F.) husk mucilage- (IHM-) alginate mucoadhesive beads containing glibenclamide by ionotropic gelation technique. The effects of sodium alginate (SA) to IHM and cross-linker (CaCl2) concentration on the drug encapsulation efficiency (DEE, %), as well as cumulative drug release after 10 hours (R10 h, %), were optimized using 32 factorial design based on response surface methodology. The observed responses were coincided well with the predicted values by the experimental design. The optimized mucoadhesive beads exhibited 94.43 ± 4.80% w/w of DEE and good mucoadhesivity with the biological membrane in wash-off test and sustained drug release profile over 10 hours. The beads were also characterized by SEM and FTIR analyses. The in vitro drug release from these beads was followed by controlled release (zero-order) pattern with super case-II transport mechanism. The optimized glibenclamide-loaded IHM-alginate mucoadhesive beads showed significant antidiabetic effect in alloxan-induced diabetic rats over prolonged period after oral administration. PMID:26555967

  9. Beta-sitosterol from psyllium seed husk (Plantago ovata Forsk) restores gap junctional intercellular communication in Ha-ras transfected rat liver cells.

    PubMed

    Nakamura, Yasushi; Yoshikawa, Noriko; Hiroki, Ikumi; Sato, Kenji; Ohtsuki, Kozo; Chang, Chia-Cheng; Upham, Brad L; Trosko, James E

    2005-01-01

    We purified compounds from the husks of psyllium seeds (Plantago ovata Forsk; desert Indian wheat), beginning with an ethanol extraction then followed by HP-20 and silica gel chromatography, which restored gap junctional intercellular communication (GJIC) in v-Ha-ras transfected rat liver epithelial WB-F344 cell line (WB-Ha-ras). GJIC was assessed by a scrape loading dye transfer assay. The active compound was identified as beta-sitosterol based on gas chromatography retention times and electron ionization mass spectroscopy (EI-MS) spectrum of authentic beta-sitosterol. Authentic beta-sitosterol restored GJIC in the tumorigenic WB-Ha-ras GJIC-deficient cells at a dose of 2.4 microM. In addition, a similar phytosterol, stigmasterol, also restored GJIC, albeit at a lower activity. beta-sitosterol and stigmasterol increased the level of connexin43 protein (Cx43) and restored phosphorylation of Cx43 to levels similar to the parental nontransfected cell line. We concluded that the restoration of intercellular communication in the GJIC-deficient, tumorigenic WB-Ha-ras cell line by the ethanol soluble fraction of psyllium seed husks is largely due to the presence of the phytosterol, beta-sitosterol. We discuss implications for dietary modulation of cancer by beta-sitosterol. PMID:15860444

  10. New data on pacific Microcope (Crustacea, Isopoda, Munnopsidae) with descriptions of two new species and redescription of M. ovata (Birstein, 1970)

    NASA Astrophysics Data System (ADS)

    Malyutina, Marina V.

    2015-01-01

    The isopod family Munnopsidae Lilljeborg, 1864 was the most diverse and species richest family among all macrobenthic organisms collected during the expedition KuramBio in the abyssal area off the Kuril-Kamchatka Trench (R.V. Sonne, 2012). The munnopsid genus MicrocopeMalyutina, 2008, represented by two species, was one of the most abundant and frequent isopod genera sampled at all stations. Microcope ovata (Birstein, 1970), the only known Pacific species of Microcope to date, is redescribed based on the new collections, since the types of the species were lost. Descriptions of a new species from the KuramBio samples, Microcope stenopigussp. nov. and a new species from the opposite side of Pacific Ocean, from the southeastern Australian slope, Microcope justisp. nov., are presented herein. These findings increase the number of described species of Microcope to five and extended the geography of the genus from the previously known South Atlantic, Antarctic and the northwestern Pacific to the new localities from the southwestern Pacific. The depth range for the genus was also extended from 2014-7370 m, to 427-7370 m. A map of the distribution of the genus Microcope and a key to the described species of Microcope are provided.

  11. Mycorrhizal diversity, seed germination and long-term changes in population size across nine populations of the terrestrial orchid Neottia ovata.

    PubMed

    Jacquemyn, Hans; Waud, Michael; Merckx, Vincent S F T; Lievens, Bart; Brys, Rein

    2015-07-01

    In plant species that rely on mycorrhizal symbioses for germination and seedling establishment, seedling recruitment and temporal changes in abundance can be expected to depend on fungal community composition and local environmental conditions. However, disentangling the precise factors that determine recruitment success in species that critically rely on mycorrhizal fungi represents a major challenge. In this study, we used seed germination experiments, 454 amplicon pyrosequencing and assessment of soil conditions to investigate the factors driving changes in local abundance in 28 populations of the orchid Neottia ovata. Comparison of population sizes measured in 2003 and 2013 showed that nearly 60% of the studied populations had declined in size (average growth rate across all populations: -0.01). Investigation of the mycorrhizal fungi in both the roots and soil revealed a total of 68 species of putatively mycorrhizal fungi, 21 of which occurred exclusively in roots, 25 that occurred solely in soil and 22 that were observed in both the soil and roots. Seed germination was limited and significantly and positively related to soil moisture content and soil pH, but not to fungal community composition. Large populations or populations with high population growth rates showed significantly higher germination than small populations or populations declining in size, but no significant relationships were found between population size or growth and mycorrhizal diversity. Overall, these results indicate that temporal changes in abundance were related to the ability of seeds to germinate, but at the same time they provided limited evidence that variation in fungal communities played an important role in determining population dynamics. PMID:25963669

  12. Culture-Independent Study of the Late-Stage of a Bloom of the Toxic Dinoflagellate Ostreopsis cf. ovata: Preliminary Findings Suggest Genetic Differences at the Sub-Species Level and Allow ITS2 Structure Characterization.

    PubMed

    Ramos, Vitor; Salvi, Daniele; Machado, João Paulo; Vale, Micaela; Azevedo, Joana; Vasconcelos, Vitor

    2015-07-01

    Available genomic data for the toxic, bloom-forming, benthic Ostreopsis spp. are traditionally obtained from isolates rather than from individuals originally present in environmental samples. Samples from the final phase of the first reported Ostreopsis bloom in European North Atlantic waters (Algarve, south coast of Portugal) were studied and characterized, using a culture-independent approach. In the first instance, a microscopy-based analysis revealed the intricate complexity of the samples. Then, we evaluated the adequacy of commonly used molecular tools (i.e., primers and nuclear ribosomal markers) for the study of Ostreopsis diversity in natural samples. A PCR-based methodology previously developed to identify/detect common Ostreopsis species was tested, including one new combination of existing PCR primers. Two sets of environmental rRNA sequences were obtained, one of them (1052 bp) with the newly tested primer set. These latter sequences encompass both the ITS1-5.8S-ITS2 region and the D1/D2 domain of the LSU rRNA gene, leading us to an accurate identification of ITS2. In turn, this allowed us to predict and show for the first time the ITS2 secondary structure of Ostreopsis. With 92 bp in length and a two-helix structure, the ITS2 of this genus revealed to be unique among the dinoflagellates. Both the PCR approach as the phylogenetic analyses allowed to place the Ostreopsis cells observed in the samples within the O. cf. ovata phylospecies' complex, discarding the presence of O. cf. siamensis. The (phylo)genetic results point out a certain level of nucleotide sequence divergence, but were inconclusive in relation to a possible geographic origin of the O. cf. ovata population from the Algarve's bloom. PMID:26134259

  13. Culture-Independent Study of the Late-Stage of a Bloom of the Toxic Dinoflagellate Ostreopsis cf. ovata: Preliminary Findings Suggest Genetic Differences at the Sub-Species Level and Allow ITS2 Structure Characterization

    PubMed Central

    Ramos, Vitor; Salvi, Daniele; Machado, João Paulo; Vale, Micaela; Azevedo, Joana; Vasconcelos, Vitor

    2015-01-01

    Available genomic data for the toxic, bloom-forming, benthic Ostreopsis spp. are traditionally obtained from isolates rather than from individuals originally present in environmental samples. Samples from the final phase of the first reported Ostreopsis bloom in European North Atlantic waters (Algarve, south coast of Portugal) were studied and characterized, using a culture-independent approach. In the first instance, a microscopy-based analysis revealed the intricate complexity of the samples. Then, we evaluated the adequacy of commonly used molecular tools (i.e., primers and nuclear ribosomal markers) for the study of Ostreopsis diversity in natural samples. A PCR-based methodology previously developed to identify/detect common Ostreopsis species was tested, including one new combination of existing PCR primers. Two sets of environmental rRNA sequences were obtained, one of them (1052 bp) with the newly tested primer set. These latter sequences encompass both the ITS1-5.8S-ITS2 region and the D1/D2 domain of the LSU rRNA gene, leading us to an accurate identification of ITS2. In turn, this allowed us to predict and show for the first time the ITS2 secondary structure of Ostreopsis. With 92 bp in length and a two-helix structure, the ITS2 of this genus revealed to be unique among the dinoflagellates. Both the PCR approach as the phylogenetic analyses allowed to place the Ostreopsis cells observed in the samples within the O. cf. ovata phylospecies’ complex, discarding the presence of O. cf. siamensis. The (phylo)genetic results point out a certain level of nucleotide sequence divergence, but were inconclusive in relation to a possible geographic origin of the O. cf. ovata population from the Algarve’s bloom. PMID:26134259

  14. Comparative pharmacokinetics and brain distribution of magnolol and honokiol after oral administration of Magnolia officinalis cortex extract and its compatibility with other herbal medicines in Zhi-Zi-Hou-Po Decoction to rats.

    PubMed

    Liu, Yuan; Wang, Dan; Yang, Gongjun; Shi, Qingshui; Feng, Fang

    2016-03-01

    Zhi-Zi-Hou-Po decoction (ZZHPD) is one of the famous antidepressant Chinese formulas and is composed of Magnolia officinalis cortex (HP), Gardenia jasminoides Ellis (ZZ) and Citrus aurantium L. (ZS). Magnolol (MN) and honokiol (HN) from HP are the major active ingredients responsible for the therapeutic effects of ZZHPD. The aim of this study is to compare the pharmacokinetics and rat brain distribution of MN and HN after oral administration of HP extract and its compatibility with other herbal medicines in ZZHPD by HPLC-FLD. Compared with the HP group, Tmax (time to reach peak drug concentration in plasma) and AUC(0-τ) significantly increased in the ZZHPD and HP-ZZ groups. There was little change in the HP-ZS group in comparison with the HP group, which indicated that ZZ promotes absorption extent and defers the absorption rate of MN. The different compatibility of ZZHPD had a different degree of impact on the concentration of MN and HN in brain. The concentration of MN significantly increased in the HP-ZZ group while it decreased in the HP-ZS group compared with the HP group, which explained the concentration of compounds being slightly greater in the ZZHPD group than in the HP group. HP mixed with other medicines resulted in a decrease in HN concentration in the brain, particularly HP compatible with ZS. The results could be helpful for revealing the compatibility mechanism and providing clinical medication guidance for ZZHPD. PMID:26173910

  15. Sensitive skin.

    PubMed

    Misery, L; Loser, K; Ständer, S

    2016-02-01

    Sensitive skin is a clinical condition defined by the self-reported facial presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus. Sensitive skin may occur in individuals with normal skin, with skin barrier disturbance, or as a part of the symptoms associated with facial dermatoses such as rosacea, atopic dermatitis and psoriasis. Although experimental studies are still pending, the symptoms of sensitive skin suggest the involvement of cutaneous nerve fibres and neuronal, as well as epidermal, thermochannels. Many individuals with sensitive skin report worsening symptoms due to environmental factors. It is thought that this might be attributed to the thermochannel TRPV1, as it typically responds to exogenous, endogenous, physical and chemical stimuli. Barrier disruptions and immune mechanisms may also be involved. This review summarizes current knowledge on the epidemiology, potential mechanisms, clinics and therapy of sensitive skin. PMID:26805416

  16. Climate Sensitivity

    SciTech Connect

    Lindzen, Richard

    2011-11-09

    Warming observed thus far is entirely consistent with low climate sensitivity. However, the result is ambiguous because the sources of climate change are numerous and poorly specified. Model predictions of substantial warming aredependent on positive feedbacks associated with upper level water vapor and clouds, but models are notably inadequate in dealing with clouds and the impacts of clouds and water vapor are intimately intertwined. Various approaches to measuring sensitivity based on the physics of the feedbacks will be described. The results thus far point to negative feedbacks. Problems with these approaches as well as problems with the concept of climate sensitivity will be described.

  17. Gluten Sensitivity

    MedlinePlus

    Gluten is a protein found in wheat, rye, and barley. It is found mainly in foods but ... products like medicines, vitamins, and supplements. People with gluten sensitivity have problems with gluten. It is different ...

  18. Gluten Sensitivity

    MedlinePlus

    ... have problems with gluten. It is different from celiac disease, an immune disease in which people can't ... the symptoms of gluten sensitivity are similar to celiac disease. They include tiredness and stomachaches. It can cause ...

  19. Gluten Sensitivity.

    PubMed

    Catassi, Carlo

    2015-01-01

    Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by intestinal and extraintestinal symptoms related to the ingestion of gluten-containing food in subjects who are not affected by either celiac disease (CD) or wheat allergy (WA). The prevalence of NCGS is not clearly defined yet. Indirect evidence suggests that NCGS is slightly more common than CD, the latter affecting around 1% of the general population. NCGS has been mostly described in adults, particularly in females in the age group of 30-50 years; however, pediatric case series have also been reported. Since NCGS may be transient, gluten tolerance needs to be reassessed over time in patients with NCGS. NCGS is characterized by symptoms that usually occur soon after gluten ingestion, disappear with gluten withdrawal, and relapse following gluten challenge within hours/days. The 'classical' presentation of NCGS is a combination of irritable bowel syndrome-like symptoms, including abdominal pain, bloating, bowel habit abnormalities (either diarrhea or constipation), and systemic manifestations such as 'foggy mind', headache, fatigue, joint and muscle pain, leg or arm numbness, dermatitis (eczema or skin rash), depression, and anemia. In recent years, several studies explored the relationship between the ingestion of gluten-containing food and the appearance of neurological and psychiatric disorders/symptoms like ataxia, peripheral neuropathy, schizophrenia, autism, depression, anxiety, and hallucinations (so-called gluten psychosis). The diagnosis of NCGS should be considered in patients with persistent intestinal and/or extraintestinal complaints showing a normal result of the CD and WA serological markers on a gluten-containing diet, usually reporting worsening of symptoms after eating gluten-rich food. NCGS should not be an exclusion diagnosis only. Unfortunately, no biomarker is sensitive and specific enough for diagnostic purposes; therefore, the diagnosis of NCGS is currently based on

  20. Tuberculin sensitivity.

    PubMed

    Eason, R J

    1987-06-01

    A prospective study of tuberculin sensitivity has been conducted among 3610 subjects under 20 years old in the Solomon Islands, Western Province. Mantoux positivity (greater than or equal to mm induration after 5 TU) fell from 81% during the 6 months following birth BCG vaccination to 13% for children aged 1-8 years of age among whom it was not significantly higher than the rate of 9% noted for unvaccinated subjects. Birth BCG does not, therefore, hinder the diagnostic usefulness of tuberculin testing for such children. For the study population as a whole, BCG-induced Mantoux positivity was restricted to induration under 15 mm diameter. Stronger responses were considered specific for tuberculin infection and indicated a prevalence rate that rose from 2% to 16% with age. Accelerated BCG reactions recorded among 45% of 162 tuberculin non-reactors under 8 years old indicated that the waning of tuberculin responsiveness at this time could not be equated with loss of clinical protection against tuberculosis. PMID:2441657

  1. Sensitivity Analysis in Engineering

    NASA Technical Reports Server (NTRS)

    Adelman, Howard M. (Compiler); Haftka, Raphael T. (Compiler)

    1987-01-01

    The symposium proceedings presented focused primarily on sensitivity analysis of structural response. However, the first session, entitled, General and Multidisciplinary Sensitivity, focused on areas such as physics, chemistry, controls, and aerodynamics. The other four sessions were concerned with the sensitivity of structural systems modeled by finite elements. Session 2 dealt with Static Sensitivity Analysis and Applications; Session 3 with Eigenproblem Sensitivity Methods; Session 4 with Transient Sensitivity Analysis; and Session 5 with Shape Sensitivity Analysis.

  2. How Sensitively Timed Are Sensitive Periods?

    ERIC Educational Resources Information Center

    Zener, Rita Schaefer

    2003-01-01

    Reviews Maria Montessori's view of sensitive periods and examines the kinds of help needed from adults: an open mind, specific help from a prepared learning environment, and challenges presented at the right time. Stresses the universality of sensitive periods and their connection to brain development. Focuses on the unconscious nature and…

  3. Pressure Sensitive Paints

    NASA Technical Reports Server (NTRS)

    Liu, Tianshu; Bencic, T.; Sullivan, J. P.

    1999-01-01

    This article reviews new advances and applications of pressure sensitive paints in aerodynamic testing. Emphasis is placed on important technical aspects of pressure sensitive paint including instrumentation, data processing, and uncertainty analysis.

  4. Dynamical compactness and sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Wen; Khilko, Danylo; Kolyada, Sergiĭ; Zhang, Guohua

    2016-05-01

    To link the Auslander point dynamics property with topological transitivity, in this paper we introduce dynamically compact systems as a new concept of a chaotic dynamical system (X , T) given by a compact metric space X and a continuous surjective self-map T : X → X. Observe that each weakly mixing system is transitive compact, and we show that any transitive compact M-system is weakly mixing. Then we discuss the relationships between it and other several stronger forms of sensitivity. We prove that any transitive compact system is Li-Yorke sensitive and furthermore multi-sensitive if it is not proximal, and that any multi-sensitive system has positive topological sequence entropy. Moreover, we show that multi-sensitivity is equivalent to both thick sensitivity and thickly syndetic sensitivity for M-systems. We also give a quantitative analysis for multi-sensitivity of a dynamical system.

  5. Sensitivity Test Analysis

    Energy Science and Technology Software Center (ESTSC)

    1992-02-20

    SENSIT,MUSIG,COMSEN is a set of three related programs for sensitivity test analysis. SENSIT conducts sensitivity tests. These tests are also known as threshold tests, LD50 tests, gap tests, drop weight tests, etc. SENSIT interactively instructs the experimenter on the proper level at which to stress the next specimen, based on the results of previous responses. MUSIG analyzes the results of a sensitivity test to determine the mean and standard deviation of the underlying population bymore » computing maximum likelihood estimates of these parameters. MUSIG also computes likelihood ratio joint confidence regions and individual confidence intervals. COMSEN compares the results of two sensitivity tests to see if the underlying populations are significantly different. COMSEN provides an unbiased method of distinguishing between statistical variation of the estimates of the parameters of the population and true population difference.« less

  6. Career Awareness Units, Magnolia Public Schools, Grades 1-7.

    ERIC Educational Resources Information Center

    Magnolia School District 14, AR.

    The guide contains career awareness units for grades one through seven. A chart for each grade level lists the unit titles with textbook references, resource speakers, and study trips. Some of the speakers and study trips suggested throughout the guide are specific to the local area. For each unit, concepts to be developed are coordinated in chart…

  7. Mentoring Emotionally Sensitive Individuals.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.; Self, Elizabeth

    Mentoring individuals who are gifted, talented, and creative, but somewhat emotionally sensitive is a challenging and provocative arena. Several reasons individuals experience heightened sensitivity include: lack of nurturing, abuse, alcoholism in the family, low self-esteem, unrealistic parental expectations, and parental pressure to achieve.…

  8. Are Psychopaths Morally Sensitive?

    ERIC Educational Resources Information Center

    Maxwell, Bruce; Le Sage, Leonie

    2009-01-01

    Philosophical and psychological opinion is divided over whether moral sensitivity, understood as the ability to pick out a situation's morally salient features, necessarily involves emotional engagement. This paper seeks to offer insight into this question. It reasons that if moral sensitivity does draw significantly on affective capacities of…

  9. Tuned cavity magnetometer sensitivity.

    SciTech Connect

    Okandan, Murat; Schwindt, Peter

    2009-09-01

    We have developed a high sensitivity (sensitivity levels.

  10. [Contrast sensitivity in glaucoma].

    PubMed

    Bartos, D

    1989-05-01

    Author reports on results of the contrast sensitivity examinations using the Cambridge low-contrast lattice test supplied by Clement Clarke International LTD, in patients with open-angle glaucoma and ocular hypertension. In glaucoma patients there was observed statistically significant decrease of the contrast sensitivity. In patients with ocular hypertension decrease of the contrast sensitivity was in patients affected by corresponding changes of the visual field and of the optical disc. The main advantages of the Cambridge low-contrast lattice test were simplicity, rapidity and precision of its performance. PMID:2743444

  11. Sensitivity of photoacoustic microscopy

    PubMed Central

    Yao, Junjie; Wang, Lihong V.

    2014-01-01

    Building on its high spatial resolution, deep penetration depth and excellent image contrast, 3D photoacoustic microscopy (PAM) has grown tremendously since its first publication in 2005. Integrating optical excitation and acoustic detection, PAM has broken through both the optical diffusion and optical diffraction limits. PAM has 100% relative sensitivity to optical absorption (i.e., a given percentage change in the optical absorption coefficient yields the same percentage change in the photoacoustic amplitude), and its ultimate detection sensitivity is limited only by thermal noise. Focusing on the engineering aspects of PAM, this Review discusses the detection sensitivity of PAM, compares the detection efficiency of different PAM designs, and summarizes the imaging performance of various endogenous and exogenous contrast agents. It then describes representative PAM applications with high detection sensitivity, and outlines paths to further improvement. PMID:25302158

  12. Constrained sensitivity theory

    SciTech Connect

    Greenspan, E.; Williams, M.L.

    1980-01-01

    In sensitivity and uncertainty analysis of to-be-built reactors it is customary to use k-reset sensitivity functions - accounting for the combined effects of the change (or uncertainty) in the input data and of the alteration in some design variable applied to maintain criticality. Critical reactors are usually subjected to several constraints, such as power peaking factor and breeding ratio constraints, in addition to the criticality constraint. Perturbation theory formulations which can account, simultaneously, for several constraints both in critical reactors and in source driven systems (such as radiation shields and blankets of fusion devices) are presented. All the sensitivity and uncertainty analyses of source driven systems carried out so far used unconstrained sensitivity functions despite the fact that such systems can be also subjected to a variety of constraints.

  13. Contact sensitization in children.

    PubMed

    Manzini, B M; Ferdani, G; Simonetti, V; Donini, M; Seidenari, S

    1998-01-01

    Our study concerns contact sensitization in children, the frequency of which is still debated in the literature, even though specific reports are increasing. During a 7 year period (1988-1994) 670 patients, 6 months to 12 years of age, were patch tested with the European standard series, integrated with 24 haptens, at the same concentrations as for adults. We observed positive results in 42% of our patients. Thimerosal, nickel sulfate, Kathon CG, fragrance mix, neomycin, wool alcohols, and ammoniated mercury induced most of the positive responses. The highest sensitization rate was found in children from 0 to 3 years of age. Comments on main positive haptens are reported. Seventy-seven percent of our sensitized patients were atopics, suggesting that atopy represents a predisposing factor for contact hypersensitivity. Patch testing represents a useful diagnostic procedure for the definition of childhood eczematous dermatitis and for the identification of agents inducing contact sensitization which is frequently associated with atopic dermatitis. PMID:9496796

  14. LISA Telescope Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    The results of a LISA telescope sensitivity analysis will be presented, The emphasis will be on the outgoing beam of the Dall-Kirkham' telescope and its far field phase patterns. The computed sensitivity analysis will include motions of the secondary with respect to the primary, changes in shape of the primary and secondary, effect of aberrations of the input laser beam and the effect the telescope thin film coatings on polarization. An end-to-end optical model will also be discussed.

  15. Allergic sensitization: screening methods.

    PubMed

    Ladics, Gregory S; Fry, Jeremy; Goodman, Richard; Herouet-Guicheney, Corinne; Hoffmann-Sommergruber, Karin; Madsen, Charlotte B; Penninks, André; Pomés, Anna; Roggen, Erwin L; Smit, Joost; Wal, Jean-Michel

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute's Health and Environmental Sciences Institute. PMID:24739743

  16. Sensitivity Analysis Without Assumptions

    PubMed Central

    VanderWeele, Tyler J.

    2016-01-01

    Unmeasured confounding may undermine the validity of causal inference with observational studies. Sensitivity analysis provides an attractive way to partially circumvent this issue by assessing the potential influence of unmeasured confounding on causal conclusions. However, previous sensitivity analysis approaches often make strong and untestable assumptions such as having an unmeasured confounder that is binary, or having no interaction between the effects of the exposure and the confounder on the outcome, or having only one unmeasured confounder. Without imposing any assumptions on the unmeasured confounder or confounders, we derive a bounding factor and a sharp inequality such that the sensitivity analysis parameters must satisfy the inequality if an unmeasured confounder is to explain away the observed effect estimate or reduce it to a particular level. Our approach is easy to implement and involves only two sensitivity parameters. Surprisingly, our bounding factor, which makes no simplifying assumptions, is no more conservative than a number of previous sensitivity analysis techniques that do make assumptions. Our new bounding factor implies not only the traditional Cornfield conditions that both the relative risk of the exposure on the confounder and that of the confounder on the outcome must satisfy but also a high threshold that the maximum of these relative risks must satisfy. Furthermore, this new bounding factor can be viewed as a measure of the strength of confounding between the exposure and the outcome induced by a confounder. PMID:26841057

  17. Allergic sensitization: screening methods

    PubMed Central

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute. PMID:24739743

  18. CONTINUOUSLY SENSITIVE BUBBLE CHAMBER

    DOEpatents

    Good, R.H.

    1959-08-18

    A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

  19. Sensitivity analysis of SPURR

    SciTech Connect

    Witholder, R.E.

    1980-04-01

    The Solar Energy Research Institute has conducted a limited sensitivity analysis on a System for Projecting the Utilization of Renewable Resources (SPURR). The study utilized the Domestic Policy Review scenario for SPURR agricultural and industrial process heat and utility market sectors. This sensitivity analysis determines whether variations in solar system capital cost, operation and maintenance cost, and fuel cost (biomass only) correlate with intuitive expectations. The results of this effort contribute to a much larger issue: validation of SPURR. Such a study has practical applications for engineering improvements in solar technologies and is useful as a planning tool in the R and D allocation process.

  20. RESRAD parameter sensitivity analysis

    SciTech Connect

    Cheng, J.J.; Yu, C.; Zielen, A.J.

    1991-08-01

    Three methods were used to perform a sensitivity analysis of RESRAD code input parameters -- enhancement of RESRAD by the Gradient Enhanced Software System (GRESS) package, direct parameter perturbation, and graphic comparison. Evaluation of these methods indicated that (1) the enhancement of RESRAD by GRESS has limitations and should be used cautiously, (2) direct parameter perturbation is tedious to implement, and (3) the graphics capability of RESRAD 4.0 is the most direct and convenient method for performing sensitivity analyses. This report describes procedures for implementing these methods and presents a comparison of results. 3 refs., 9 figs., 8 tabs.

  1. Genetics Home Reference: warfarin sensitivity

    MedlinePlus

    ... Understand Genetics Home Health Conditions warfarin sensitivity warfarin sensitivity Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Warfarin sensitivity is a condition in which individuals have a ...

  2. Sensitive hydrogen leak detector

    DOEpatents

    Myneni, G.R.

    1999-08-03

    A sensitive hydrogen leak detector system is described which uses passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor. 1 fig.

  3. The Emotionally Sensitive Adolescent.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.; Lehtonen, Kimmo

    This paper provides a list of signs, symptoms, and indicators of emotionally sensitive adolescents includes clinging behavior, withdrawn behavior, shy/inhibited behavior, represses anger, poor reaction to criticism, makes self-disparaging statements, low self-esteem, "can't forgive self or others," ruined by a small critical comment, exploding…

  4. High-Sensitivity Spectrophotometry.

    ERIC Educational Resources Information Center

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  5. Sensitization of Parker fittings

    SciTech Connect

    Wilber, W.W.

    1985-09-01

    At your request, ferrules from 316 SS Parker-Hannifen compression fittings at the FFTF have been examined and evaluated to determine the metallurgical condition as related to carbide precipitation in grain boundaries (known as sensitization) and the implications this may have with regard to corrosion resistance. To accomplish this, two ferrules from new stock, two ferrules from old stock and two ferrules that had seen service were examined metallurgically. The samples were prepared for optical metallography. They were viewed in both the etched and unetched condition and analyzed on the scanning electron microscope (SEM) for elemental content. It was confirmed that the ferrules from new stock had a 5 mil thick nitrided layer on the ferrule ID at the lead end and that the 316 SS ferrule material was in the sensitized condition, indicating low resistance to aqueous corrosion. The material from old stock had no nitride layer but was in the sensitized condition indicating low resistance to aqueous corrosion. The ferrules that had seen service had not been nitrided and were not sensitized indicating high resistance to aqueous corrosion.

  6. Sensitization of stainless steel

    NASA Technical Reports Server (NTRS)

    Nagy, James P.

    1990-01-01

    The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

  7. Sensitive hydrogen leak detector

    DOEpatents

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  8. UNITEC SENS-IT

    EPA Science Inventory

    The UniTec Sens-It is a small gas-sensing device that can measure volatile organic compounds (VOCs). This sensor is used to measure VOCs in applications such as urban air quality, roadside pollution, and (solid waste) landfill monitoring. This operating procedure explains what yo...

  9. Visual sensitivity tester

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A.

    1972-01-01

    Testing device uses closed loop film cassettes to project programmed visual stimuli on screen which the observer views through a lens making the stimuli appear to be at optical infinity. Tester is useful for determining changes in glautomatous visual field sensitivity.

  10. Scaling in sensitivity analysis

    USGS Publications Warehouse

    Link, W.A.; Doherty, P.F., Jr.

    2002-01-01

    Population matrix models allow sets of demographic parameters to be summarized by a single value 8, the finite rate of population increase. The consequences of change in individual demographic parameters are naturally measured by the corresponding changes in 8; sensitivity analyses compare demographic parameters on the basis of these changes. These comparisons are complicated by issues of scale. Elasticity analysis attempts to deal with issues of scale by comparing the effects of proportional changes in demographic parameters, but leads to inconsistencies in evaluating demographic rates. We discuss this and other problems of scaling in sensitivity analysis, and suggest a simple criterion for choosing appropriate scales. We apply our suggestions to data for the killer whale, Orcinus orca.

  11. Hypochlorite sensitivity in man.

    PubMed

    Hostynek, J J; Patrick, E; Younger, B; Maibach, H I

    1989-01-01

    Observation of an individual with immediate-type reaction following exaggerated dermal exposure to hypochlorite-containing cleaning products prompted review of similar hypersensitivity reactions attributed to hypochlorite or other highly reactive chemicals. This review confirms isolated incidences of hypochlorite sensitivity of the delayed type (allergic contact dermatitis), as well as immediate-type reactions from inhalation or topical challenge of sensitized individuals. We conclude that it is possible that excessive and prolonged exposure to hypochlorite may in some cases result in irritation and damage to the skin. This potentially gives rise to altered proteins which in rare cases may cause hypersensitivity. This reaction is common to other reactive small molecules with a strong irritant action. PMID:2536603

  12. Temperature sensitive auditory neuropathy.

    PubMed

    Zhang, Qiujing; Lan, Lan; Shi, Wei; Yu, Lan; Xie, Lin-Yi; Xiong, Fen; Zhao, Cui; Li, Na; Yin, Zifang; Zong, Liang; Guan, Jing; Wang, Dayong; Sun, Wei; Wang, Qiuju

    2016-05-01

    Temperature sensitive auditory neuropathy is a very rare and puzzling disorder. In the present study, we reported three unrelated 2 to 6 year-old children who were diagnosed as auditory neuropathy patients who complained of severe hearing loss when they had fever. Their hearing thresholds varied from the morning to the afternoon. Two of these patients' hearing improved with age, and one patient received positive results from cochlear implant. Genetic analysis revealed that these three patients had otoferlin (OTOF) homozygous or compound heterozygous mutations with the genotypes c.2975_2978delAG/c.4819C>T, c.4819C>T/c.4819C>T, or c.2382_2383delC/c.1621G>A, respectively. Our study suggests that these gene mutations may be the cause of temperature sensitive auditory neuropathy. The long term follow up results suggest that the hearing loss in this type of auditory neuropathy may recover with age. PMID:26778470

  13. LISA Telescope Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. As with any optical system, even one with such very large separations between the transmitting and receiving, telescopes, a sensitivity analysis should be performed to see how, in this case, the far field phase varies when the telescope parameters change as a result of small temperature changes.

  14. CDF's Higgs sensitivity status

    SciTech Connect

    Junk, Tom; /Illinois U., Urbana

    2005-10-01

    The combined sensitivity of CDF's current Standard Model Higgs boson searches is presented. The expected 95% CL limits on the production cross section times the relevant Higgs boson branching ratios are computed for the W{sup {+-}}H {yields} {ell}{sup {+-}}{nu}b{bar b}, ZH {yields} {nu}{bar {nu}}b{bar b}, gg {yields} H {yields} W{sup +}W{sup -} W{sup {+-}}H {yields} W{sup {+-}}W{sup +}W{sup -} channels as they stand as of the October 2005, using results which were prepared for Summer 2005 conferences and a newer result form the gg {yields} H {yields} W{sup +}W{sup -} channel. Correlated and uncorrelated systematic uncertainties are taken into account, and the luminosity requirements for 95% CL exclusion, 3{sigma} evidence, and 5{sigma} discovery are computed for median experimental outcomes. A list of improvements required to achieve the sensitivity to a SM Higgs boson as quantified in the Higgs Sensitivity Working Group's report is provided.

  15. Heat sensitive immunoliposomes

    SciTech Connect

    Sullivan, S.M.

    1985-01-01

    Heat sensitive immunoliposomes were prepared with derivatized antibody. The liposomes are able to bind specifically to target cells and to release their encapsulated contents upon brief heating. Monoclonal anti-H2K/sup K/ was covalently derivatized with palmitoyl-N-hydroxysuccinimide. The palmitoyl antibody was injected at a controlled rate into a suspension of fused unilamellar dipalmitoylphosphati-dylcholine liposomes maintained at a constant temperature. Injection of palmitoyl antibody into a liposome suspension containing 50 mM carboxyfluorescein at 41/sup 0/C resulted in simultaneous antibody incorporation and entrapment of dye. The immunoliposomes were able to release entrapped dye upon heating. Furthermore, this ability was retained when the immunoliposomes were found to the target cells. /sup 3/H-Uridine was entrapped in the heat sensitive immunoliposomes to examine the cellular uptake properties of entrapped contents upon release. The release of uridine from bound heat sensitive immunoliposomes exhibited very similar properties to those obtained for carboxyfluorescein release. The rate of uridine uptake for immunoliposome released uridine was 5 fold greater than bare liposome released uridine and 10 fold greater than that obtained for free uridine. Nucleoside uptake inhibitors were able to inhibit uptake of free uridine and uridine released from immunoliposomes showing the release to be extracellular and uridine uptake was mediated by the nucleoside transporter. These results show that a high local concentration of nucleosides released from immunoliposomes bound to their respective target cell can enhance cellular uptake thus promoting efficient drug delivery.

  16. Sensitivity testing and analysis

    SciTech Connect

    Neyer, B.T.

    1991-01-01

    New methods of sensitivity testing and analysis are proposed. The new test method utilizes Maximum Likelihood Estimates to pick the next test level in order to maximize knowledge of both the mean, {mu}, and the standard deviation, {sigma} of the population. Simulation results demonstrate that this new test provides better estimators (less bias and smaller variance) of both {mu} and {sigma} than the other commonly used tests (Probit, Bruceton, Robbins-Monro, Langlie). A new method of analyzing sensitivity tests is also proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions, for {mu}, {sigma}, and arbitrary percentiles. Unlike presently used methods, such as the program ASENT which is based on the Cramer-Rao theorem, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The new test and analysis methods will be explained and compared to the presently used methods. 19 refs., 12 figs.

  17. Kinematic sensitivity of robot manipulators

    NASA Technical Reports Server (NTRS)

    Vuskovic, Marko I.

    1989-01-01

    Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors.

  18. Genetics of quantitative and qualitative traits of isabgol (Plantago ovata).

    PubMed

    Singh, N; Lal, R K

    2009-01-01

    Isabgol is a medicinal plant known for its high-quality dietary fiber. The genetics and inheritance of economic characters, such as number of panicles, panicle length, seed yield, and swelling factor, were measured by diallel analysis of F(1) progenies from seven parents. The additive component of genetic variance was significant for days to flowering, plant height, branches/plant, peduncle length, panicle length, days to maturity, and swelling factor, whereas the dominance component of genetic variance was significant for all the characters except panicles/plant. Additivity was not significant for all the characters, indicating absence of non-allelic interactions (epistasis) in controlling gene expression. Heritability in the narrow sense was very high for panicle length, days to flowering, and plant height, and moderate for branches/plant, panicles/plant, days to maturity, seed yield, husk yield, and swelling factor. However, the degree of genetic improvement was only high for panicle length, seed yield and husk yield. We conclude that hybridizations, isolation of superior genotypes by sib selection and recurrent selection, and exploitation of hybrid vigor in specific parental-cross combinations are good strategies for isabgol crop improvement. PMID:19731195

  19. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

  20. Dye sensitized solar cells.

    PubMed

    Wei, Di

    2010-01-01

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO(2), ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

  1. Surveillance Metrics Sensitivity Study

    SciTech Connect

    Bierbaum, R; Hamada, M; Robertson, A

    2011-11-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  2. Surveillance metrics sensitivity study.

    SciTech Connect

    Hamada, Michael S.; Bierbaum, Rene Lynn; Robertson, Alix A.

    2011-09-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  3. Hearing sensitivity in farmers.

    PubMed Central

    Karlovich, R S; Wiley, T L; Tweed, T; Jensen, D V

    1988-01-01

    Hearing sensitivity was measured for tones from 1,000 through 8,000 hertz (Hz) in 534 males and 278 females who resided in rural Wisconsin and ranged in age from 16 to 85 years. The hearing sensitivity for all subjects decreased with advancing age and at higher frequencies, but hearing loss over the range most susceptible to excessive noise exposure (3,000-6,000 Hz) was much greater for males than for females at all ages. The hearing loss was greater than could be accounted for by age and was similar whether the subject was a farmer or not. The results suggested that approximately 25 percent of the males had a communication handicap due to hearing loss by age 30, and the proportion rose to 50 percent by age 50. Less than 20 percent of farmers reported consistent use of personal hearing protection in their farm-related duties. Overall, the findings suggest that men who live in rural areas, including farmers, demonstrate a high prevalence of hearing loss and associated communication problems due to excessive noise exposure. This, in turn, clearly indicates a need for intensification of educational hearing conservation programs for the rural population. PMID:3124200

  4. Coherency Sensitive Hashing.

    PubMed

    Korman, Simon; Avidan, Shai

    2016-06-01

    Coherency Sensitive Hashing (CSH) extends Locality Sensitivity Hashing (LSH) and PatchMatch to quickly find matching patches between two images. LSH relies on hashing, which maps similar patches to the same bin, in order to find matching patches. PatchMatch, on the other hand, relies on the observation that images are coherent, to propagate good matches to their neighbors in the image plane, using random patch assignment to seed the initial matching. CSH relies on hashing to seed the initial patch matching and on image coherence to propagate good matches. In addition, hashing lets it propagate information between patches with similar appearance (i.e., map to the same bin). This way, information is propagated much faster because it can use similarity in appearance space or neighborhood in the image plane. As a result, CSH is at least three to four times faster than PatchMatch and more accurate, especially in textured regions, where reconstruction artifacts are most noticeable to the human eye. We verified CSH on a new, large scale, data set of 133 image pairs and experimented on several extensions, including: k nearest neighbor search, the addition of rotation and matching three dimensional patches in videos. PMID:26372204

  5. Modeling sensitive elasmobranch habitats

    NASA Astrophysics Data System (ADS)

    Pennino, M. Grazia; Muñoz, Facundo; Conesa, David; López-Quílez, Antonio; Bellido, José Marí; a

    2013-10-01

    Basic information on the distribution and habitat preferences of ecologically important species is essential for their management and protection. In the Mediterranean Sea there is increasing concern over elasmobranch species because their biological (ecological) characteristics make them highly vulnerable to fishing pressure. Their removal could affect the structure and function of marine ecosystems, inducing changes in trophic interactions at the community level due to the selective elimination of predators or prey species, competitors and species replacement. In this study Bayesian hierarchical spatial models are used to map the sensitive habitats of the three most caught elasmobranch species (Galeus melastomus, Scyliorhinus canicula, Etmopterus spinax) in the western Mediterranean Sea, based on fishery-dependent bottom trawl data. Results show that habitats associated with hard substrata and sandy beds, mainly in deep waters and with a high seabed gradient, have a greater probability registering the presence of the studied species than those associated with muddy shallow waters. Temperature and chlorophyll-α concentration show a negative relationship with S. canicula occurrence. Our results identify some of the sensitive habitats for elasmobranchs in the western Mediterranean Sea (GSA06 South), providing essential and easy-to-use interpretation tools, such as predictive distribution maps, with the final aim of improving management and conservation of these vulnerable species.

  6. Infant Allergies and Food Sensitivities

    MedlinePlus

    ... Size Email Print Share Infant Allergies and Food Sensitivities Page Content Article Body Human breast milk typically ... your pediatrician about your family’s medical history. Food Sensitivities A few mothers notice minor reactions to other ...

  7. The Sensitive Skin Syndrome

    PubMed Central

    Lev-Tov, Hadar; Maibach, Howard I

    2012-01-01

    Sensitive skin syndrome (SSS) is a common and challenging condition, yet little is known about its underlying pathophysiology. Patients with SSS often present with subjective complaints of severe facial irritation, burning, and/or stinging after application of cosmetic products. These complaints are out of proportion to the objective clinical findings. Defined as a self-diagnosed condition lacking any specific objective findings, SSS is by definition difficult to quantify and, therefore, the scientific community has yet to identify an acceptable objective screening test. In this overview we review recent epidemiological studies, present current thinking on the pathophysiology leading to SSS, discuss the challenges SSS presents, and recommend a commonsense approach to management. PMID:23248357

  8. Neonatal sensitization to latex.

    PubMed

    Worth, J

    2000-05-01

    Babies born in delivery rooms of hospitals are exposed to latex through skin and mucous membrane contact with prepowdered latex gloves worn by midwives and doctors, and through the inhalation of latex-bound starch powder in the air of the delivery room. This paper examines the hypothesis that they are at risk for latex sensitization, and that part of the sharp increase of childhood asthma, eczema and anaphylaxis in the past 30-40 years may be linked. These possibilities seem hitherto unsuspected. In over 700 papers on latex allergy no mention of neonatal exposure to latex has been found. Even obstetric papers discussing the risks for an atopic mother (atopy - a tendency to develop allergies) do not seem to anticipate any risk for the baby, who might also be atopic. Latex allergy is primarily regarded as an occupational hazard. This paper suggests that it is a hazard for every baby handled by latex gloves at birth. PMID:10859678

  9. Position Sensitive Microcalorimeters

    NASA Technical Reports Server (NTRS)

    Sadleir, J. E.; Hammock, C.; Figueroa-Feliciano, E.; Stahle, C. K.; Bandler, S.; Saab, T.; Lindeman, M.; Porter, F. S.; Chervenak, J.; Brown, G.

    2004-01-01

    A Position Sensitive Transition-Edge Sensor (PoST) is a microcalorimeter device capable of one-dimensional imaging spectroscopy. The device consists of two Transition-Edge Sensors (TESs) connected to the ends of a long X-ray absorbing strip. The energy of a photon hitting the absorber and the position of the absorption event along the strip is measured from the response in the two sensors by analyzing the relative signal sizes, pulse rise times, and the sum of the pulses measured at each sensor, We report on the recent PoST effort at Goddard for applications to large field of view, high-energy- resolution, X-ray astrophysics.

  10. Preloadable vector sensitive latch

    NASA Technical Reports Server (NTRS)

    Acres, William R. (Inventor)

    1987-01-01

    A preloadable vector-sensitive latch which automatically releases when the force vector from a latch memebr reaches a specified release angle is presented. In addition, it contains means to remove clearance between the latched members and to preload the latch to prevent separation at angles less than the specified release angle. The latch comprises a triangular main link, a free link connected between a first corner of the main link and a yoke member, a housing, and an actuator connected between the yoke member and the housing. A return spring bias means connects the main link to a portion of the housing. A second corner of the main link is slidably and pivotally connected to the housing via a slot in a web portion of the housing. The latch housing has a rigid docking ring alignable with a mating locking ring which is engageable by a locking roller journalled on the third corner of the triangular main link.

  11. Measuring contrast sensitivity

    PubMed Central

    Pelli, Denis G.; Bex, Peter

    2013-01-01

    Contrast sensitivity defines the threshold between the visible and invisible, which has obvious significance for basic and clinical vision science. Fechner's 1860 review reported that threshold contrast is 1% for a remarkably wide range of targets and conditions. While printed charts are still in use, computer testing is becoming more popular because it offers efficient adaptive measurement of threshold for a wide range of stimuli. Both basic and clinical studies usually want to know fundamental visual capability, regardless of the observer's subjective criterion. Criterion effects are minimized by the use of an objective task: multiple-alternative forced-choice detection or identification. Having many alternatives reduces the guessing rate, which makes each trial more informative, so fewer trials are needed. Finally, populations who may experience crowding or target confusion should be tested with one target at a time. PMID:23643905

  12. Pharmacogenetics: detecting sensitive populations.

    PubMed Central

    Shields, P G

    1994-01-01

    Risk assessment models strive to predict risks to humans from toxic agents. Safety factors and assumptions are incorporated into these models to allow a margin of error. In the case of cancer, substantial evidence shows that the carcinogenic process is a multistage process driven by the interaction of exogenous carcinogenic exposures, genetic traits, and other endogenous factors. Current risk assessment models fail to consider genetic predispositions that make people more sensitive or resistant to exogenous exposures and endogenous processes. Several cytochrome P450 enzymes, responsible for metabolically activating carcinogens and medications, express wide interindividual variation whose genetic coding has now been identified as polymorphic and linked to cancer risk. For example, a restriction fragment-length polymorphism for cytochrome P4501A1, which metabolizes polycyclic aromatic hydrocarbons, and cytochrome P4502E1, which metabolizes N-nitrosamines and benzene, is linked to lung cancer risk. Cytochrome P4502D6, responsible for metabolizing many clinically important medications, also is linked to lung cancer risk. The frequency for each of these genetic polymorphisms vary among different ethnic and racial groups. In addition to inherited factors for the detection of sensitive populations, determining the biologically effective doses for carcinogenic exposures also should quantitatively and qualitatively enhance the risk assessment process. Levels of carcinogen-DNA adducts reflect the net effect of exposure, absorption, metabolic activation, detoxification, and DNA repair. These effects are genetically predetermined, inducibility notwithstanding. The combination of adduct and genotyping assays provide an assessment of risk that reflects recent exogenous exposure as well as one's lifetime ability to activate and detoxify carcinogens. PMID:7737047

  13. Stratospheric Airship Design Sensitivity

    NASA Astrophysics Data System (ADS)

    Smith, Ira Steve; Fortenberry, Michael; Noll, . James; Perry, William

    2012-07-01

    The concept of a stratospheric or high altitude powered platform has been around almost as long as stratospheric free balloons. Airships are defined as Lighter-Than-Air (LTA) vehicles with propulsion and steering systems. Over the past five (5) years there has been an increased interest by the U. S. Department of Defense as well as commercial enterprises in airships at all altitudes. One of these interests is in the area of stratospheric airships. Whereas DoD is primarily interested in things that look down, such platforms offer a platform for science applications, both downward and outward looking. Designing airships to operate in the stratosphere is very challenging due to the extreme high altitude environment. It is significantly different than low altitude airship designs such as observed in the familiar advertising or tourism airships or blimps. The stratospheric airship design is very dependent on the specific application and the particular requirements levied on the vehicle with mass and power limits. The design is a complex iterative process and is sensitive to many factors. In an effort to identify the key factors that have the greatest impacts on the design, a parametric analysis of a simplified airship design has been performed. The results of these studies will be presented.

  14. Stochastic resonance in visual sensitivity.

    PubMed

    Kundu, Ajanta; Sarkar, Sandip

    2015-04-01

    It is well known from psychophysical studies that stochastic resonance, in its simplest threshold paradigm, can be used as a tool to measure the detection sensitivity to fine details in noise contaminated stimuli. In the present manuscript, we report simulation studies conducted in the similar threshold paradigm of stochastic resonance. We have estimated the contrast sensitivity in detecting noisy sine-wave stimuli, with varying area and spatial frequency, as a function of noise strength. In all the cases, the measured sensitivity attained a peak at intermediate noise strength, which indicate the occurrence of stochastic resonance. The peak sensitivity exhibited a strong dependence on area and spatial frequency of the stimulus. We show that the peak contrast sensitivity varies with spatial frequency in a nonmonotonic fashion and the qualitative nature of the sensitivity variation is in good agreement with human contrast sensitivity function. We also demonstrate that the peak sensitivity first increases and then saturates with increasing area, and this result is in line with the results of psychophysical experiments. Additionally, we also show that critical area, denoting the saturation of contrast sensitivity, decreases with spatial frequency and the associated maximum contrast sensitivity varies with spatial frequency in a manner that is consistent with the results of psychophysical experiments. In all the studies, the sensitivities were elevated via a nonlinear filtering operation called stochastic resonance. Because of this nonlinear effect, it was not guaranteed that the sensitivities, estimated at each frequency, would be in agreement with the corresponding results of psychophysical experiments; on the contrary, close agreements were observed between our results and the findings of psychophysical investigations. These observations indicate the utility of stochastic resonance in human vision and suggest that this paradigm can be useful in psychophysical studies

  15. Sensitivity analysis in computational aerodynamics

    NASA Technical Reports Server (NTRS)

    Bristow, D. R.

    1984-01-01

    Information on sensitivity analysis in computational aerodynamics is given in outline, graphical, and chart form. The prediction accuracy if the MCAERO program, a perturbation analysis method, is discussed. A procedure for calculating perturbation matrix, baseline wing paneling for perturbation analysis test cases and applications of an inviscid sensitivity matrix are among the topics covered.

  16. Parameter Sensitivity in Multivariate Methods

    ERIC Educational Resources Information Center

    Green, Bert F., Jr.

    1977-01-01

    Interpretation of multivariate models requires knowing how much the fit of the model is impaired by changes in the parameters. The relation of parameter change to loss of goodness of fit can be called parameter sensitivity. Formulas are presented for assessing the sensitivity of multiple regression and principal component weights. (Author/JKS)

  17. NCLEX fairness and sensitivity review.

    PubMed

    Wendt, Anne; Kenny, Lorraine; Riley, Michelle

    2009-01-01

    The National Council Licensing Examination is an examination that is used for the purpose of licensing registered nurses and practical/vocational nurses. To help ensure that the examination questions (items) are fair and unbiased, all items undergo a fairness and sensitivity review as part of the item development process. This article focuses on the fairness and sensitivity review. PMID:19726969

  18. Radiation Sensitization in Cancer Therapy.

    ERIC Educational Resources Information Center

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,…

  19. Sensitizing ESL Learners to Genre

    ERIC Educational Resources Information Center

    Swami, Jasti Appa

    2008-01-01

    This article evaluates the efficacy of explicit genre-based instruction by sensitizing the ESL learners to the concept of genre. The main questions addressed are: How does sensitizing ESL learners to the rhetorical move structure of a genre, the communicative purposes of these moves, and linguistic features that realize these moves help them to…

  20. Threat sensitivity, incentive sensitivity, and the experience of relief.

    PubMed

    Carver, Charles S

    2009-02-01

    Relief is a positively valenced affect that occurs when a threat is removed or avoided. Among dimensional theories, this experience is accounted for by appealing to one of two different self-regulatory systems. Some hold that an approach system is responsible for all types of positively valenced affect, including this one. Others hold that an avoidance system is responsible for this particular positive affect. Two studies are reported (total N=422) that examined this issue, using a method in which individual differences in overall threat sensitivity and incentive sensitivity were assessed and related to responses to relief-related hypothetical scenarios. Threat sensitivity was the strongest positive correlate of relief in both studies. Reward responsiveness also related positively (independently) to relief. Fun seeking related inversely to relief. Discussion centers on theoretical implications of the findings for viewing effects of threat sensitivity, and on relations between dimensional and appraisal-based views of affective experience. PMID:19076994

  1. Mechanisms of multiple chemical sensitivity.

    PubMed

    Winder, Chris

    2002-03-10

    Sensitivity to chemicals is a toxicological concept, contained in the dose-response relationship. Sensitivity also includes the concept of hypersensitivity, although controversy surrounds the nature of effects from very low exposures. The term multiple chemical sensitivity has been used to describe individuals with a debilitating, multi-organ sensitivity following chemical exposures. Many aspects of this condition extend the nature of sensitivity to low levels of exposure to chemicals, and is a designation with medical, immunological, neuropsychological and toxicological perspectives. The basis of MCS is still to be identified, although a large number of hypersensitivity, immunological, psychological, neurological and toxicological mechanisms have been suggested, including: allergy; autosuggestion; cacosomia; conditioned response; immunological; impairment of biochemical pathways involved in energy production; impairment of neurochemical pathways; illness belief system; limbic kindling; olfactory threshold sensitivity; panic disorder; psychosomatic condition; malingering; neurogenic inflammation; overload of biotransformation pathways (also linked with free radical production); psychological or psychiatric illness; airway reactivity; sensitisation of the neurological system; time dependent sensitisation, toxicant induced loss of tolerance. Most of these theories tend to break down into concepts involving: (1) disruption in immunological/allergy processes; (2) alteration in nervous system function; (3) changes in biochemical or biotransformation capacity; (4) changes in psychological/neurobehavioural function. Research into the possible mechanisms of MCS is far from complete. However, a number of promising avenues of investigation indicate that the possibility of alteration of the sensitivity of nervous system cells (neurogenic inflammation, limbic kindling, cacosomia, neurogenic switching) are a possible mechanism for MCS. PMID:11869820

  2. Frequency sensitivity for video compression

    NASA Astrophysics Data System (ADS)

    Seo, Guiwon; Lee, Jonghwa; Lee, Chulhee

    2014-03-01

    We investigate the frequency sensitivity of the human visual system, which reacts differently at different frequencies in video coding. Based on this observation, we used different quantization steps for different frequency components in order to explore the possibility of improving coding efficiency while maintaining perceptual video quality. In other words, small quantization steps were used for sensitive frequency components while large quantization steps were used for less sensitive frequency components. We performed subjective testing to examine the perceptual video quality of video sequences encoded by the proposed method. The experimental results showed that a reduction in bitrate is possible without causing a decrease in perceptual video quality.

  3. [Clinical significance of calcium sensitizer].

    PubMed

    Sakata, Yasushi

    2013-04-01

    Oral inotropes did not always improve mortality of the patients with heart failure partly because of possible direct toxic effects of these agents on myocytes, exacerbating arrhythmias, enhancing neurohormonal activity. Ca(2 +) sensitizers such as pimobendan and levosimendan was expected to improve even mortality of the patients with heart failure through increasing cardiac contractility without a rise in intracellular calcium. However, the trials using these agents disappoint our expectations. We need the development of the agents which has more specific effect of Ca(2 +) sensitizing and the selection of the patients who will receive the benefits of Ca(2 +) sensitizers. PMID:23545748

  4. Geophone with depth sensitive spikes

    SciTech Connect

    Rice, J.A.; Houston, L.M.; Arevalo, R.

    1992-06-23

    This patent describes a geophone. It comprises a seismic sensitive element for sensing elastic motion and converting the motion to an electrical signal, a housing for enclosing the seismic element, and an elongated spike attachable to the housing.

  5. Mass-sensitive chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Adkins, Douglas R.; Lewis, Patrick R.

    2007-01-30

    A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  6. Solid rocket motor temperature sensitivity

    SciTech Connect

    Osborn, J.R.; Heister, S.D.

    1994-11-01

    The temperature sensitivity of the propellant and the solid rocket motor are described by several different temperature sensitivity coefficients. This enabled the derivation of three different relationships for the temperature sensitivity coefficient pi(sub K). To demonstrate this, two different propellants were used wherein the values of pi(sub K) were generated and compared. It was observed that the expressions are of equal complexity and offer ease of use. All involve only the burning rate data and the use of the parameters in St. Roberts burning rate low. It is also suggested that the most general expression for the sensitivity coefficient should be used since it is a true pi(sub K) relationship having the partial derivatives taken with the motor geometry held constant. 11 refs.

  7. Ringberg15: Earth's Climate Sensitivities

    NASA Technical Reports Server (NTRS)

    Stevens, Bjorn; Abe-Ouchi, Ayako; Bony, Sandrine; Hegerl, Gabi; Schmidt, Gavin; Sherwood, Steven; Webb, Mark

    2015-01-01

    To assess gaps in understanding of Earth's climate sensitivities a workshop was organised under the auspices of the WCRP (World Climate Research Programme) Grand Science Challenge on Clouds, Circulation and Climate Sensitivity (Ringberg15). The workshop took place in March 2015 and gathered together over thirty experts from around the world for one week. Attendees each gave short presentations and participated in moderated discussions of specific questions related to understanding Earth's climate sensitivities. Most of the time was focused on understanding of the equilibrium climate sensitivity, defined as the equilibrium near-surface warming associated with a doubling of atmospheric carbon dioxide. The workshop produced nine recommendations, many of them focusing on specific research avenues that could be exploited to advance understanding of climate sensitivity. Many of these dealt, in one fashion or another, with the need to more sharply focus research on identifying and testing story lines for a high (larger than 4 degrees Kelvin) or low (less than 2 degrees Kelvin) equilibrium climate sensitivity. Additionally, a subset of model intercomparison projects (CFMIP (Cloud Feedback Model Intercomparison Project), PMIP (Palaeoclimate Modelling Intercomparison Project), PDRMIP (Precipitation Driver and Response Model Intercomparison Project), RFMIP (Radiative Forcing Model Intercomparison Project) and VolMIP (Volcanic Forcings Model Intercomparison Project)) that have been proposed for inclusion within CMIP were identified as being central to resolving important issues raised at the workshop; for this reason modelling groups were strongly encouraged to participate in these projects. Finally the workshop participants encouraged the WCRP to initiate and support an assessment process lead by the Grand Science Challenge on Clouds, Circulation and Climate Sensitivity on the topic of Earth's Climate Sensitivities, culminating in a report that will be published in 2019

  8. Metal-Free Sensitizers for Dye-Sensitized Solar Cells.

    PubMed

    Chaurasia, Sumit; Lin, Jiann T

    2016-06-01

    This review focuses on our work on metal-free sensitizers for dye-sensitized solar cells (DSSCs). Sensitizers based on D-A'-π-A architecture (D is a donor, A is an acceptor, A' is an electron-deficient entity) exhibit better light harvesting than D-π-A-type sensitizers. However, appropriate molecular design is needed to avoid excessive aggregation of negative charge at the electron-deficient entity upon photoexcitation. Rigidified aromatics, including aromatic segments comprising fused electron-excessive and -deficient units in the spacer, allow effective electronic communication, and good photoinduced charge transfer leads to excellent cell performance. Sensitizers with two anchors/acceptors, D(-π-A)2 , can more efficiently harvest light, inject electrons, and suppress dark current compared with congeners with a single anchor. Appropriate incorporation of heteroaromatic units in the spacer is beneficial to DSSC performance. High-performance, aqueous-based DSSCs can be achieved with a dual redox couple comprising imidazolium iodide and 2,2,6,6-tetramethylpiperidin-N-oxyl, and/or using dyes of improved wettability through the incorporation of a triethylene oxide methyl ether chain. PMID:27114164

  9. LPS from Porphyromonas gingivalis Sensitizes Capsaicin-Sensitive Nociceptors

    PubMed Central

    Ferraz, Caio Cezar Randi; Diógenes, Aníbal; Henry, Michael A.; Hargreaves, Kenneth M.

    2010-01-01

    Although odontogenic infections are often accompanied by pain, little is known about the potential mechanisms mediating this effect. In this study, we tested the hypothesis that trigeminal nociceptive neurons are directly sensitized by lipopolysaccharide (LPS) isolated from an endodontic pathogen, Porphyromonas gingivalis (P. gingivalis). In vitro studies conducted with cultures of rat trigeminal neurons demonstrated that pretreatment with LPS produced a significant increase in the capsaicin-evoked release of calcitonin gene-related peptide (CGRP) when compared to vehicle pretreatment, thus showing sensitization of the capsaicin receptor, TRPV1, by LPS. Furthermore, confocal microscopic examination of human tooth pulp samples showed the colocalization of the LPS receptor (toll-like receptor 4; TLR4) with CGRP containing nerve fibers. Collectively, these results suggest the direct sensitization of nociceptors by LPS at concentrations found in infected canal systems as one mechanism responsible for the pain associated with bacterial infections. PMID:21146075

  10. Some More Sensitive Measures of Sensitivity and Response Bias

    NASA Technical Reports Server (NTRS)

    Balakrishnan, J. D.

    1998-01-01

    In this article, the author proposes a new pair of sensitivity and response bias indices and compares them to other measures currently available, including d' and Beta of signal detection theory. Unlike d' and Beta, these new performance measures do not depend on specific distributional assumptions or assumptions about the transformation from stimulus information to a discrimination judgment with simulated and empirical data, the new sensitivity index is shown to be more accurate than d' and 16 other indices when these measures are used to compare the sensitivity levels of 2 experimental conditions. Results from a perceptual discrimination experiment demonstrate the feasibility of the new distribution-free bias index and suggest that biases of the type defined within the signal detection theory framework (i.e., the placement of a decision criterion) do not exist, even under an asymmetric payoff manipulation.

  11. Dye-sensitized solar cells based on purple corn sensitizers

    NASA Astrophysics Data System (ADS)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  12. Climate Sensitivity in the Anthropocene

    NASA Technical Reports Server (NTRS)

    Previdi, M.; Liepert, B. G.; Peteet, Dorothy M.; Hansen, J.; Beerling, D. J.; Broccoli, A. J.; Frolking, S.; Galloway, J. N.; Heimann, M.; LeQuere, C.; Levitus, S.; Ramaswamy, V.

    2014-01-01

    Climate sensitivity in its most basic form is defined as the equilibrium change in global surface temperature that occurs in response to a climate forcing, or externally imposed perturbation of the planetary energy balance. Within this general definition, several specific forms of climate sensitivity exist that differ in terms of the types of climate feedbacks they include. Based on evidence from Earth's history, we suggest here that the relevant form of climate sensitivity in the Anthropocene (e.g. from which to base future greenhouse gas (GHG) stabilization targets) is the Earth system sensitivity including fast feedbacks from changes in water vapour, natural aerosols, clouds and sea ice, slower surface albedo feedbacks from changes in continental ice sheets and vegetation, and climate-GHG feedbacks from changes in natural (land and ocean) carbon sinks. Traditionally, only fast feedbacks have been considered (with the other feedbacks either ignored or treated as forcing), which has led to estimates of the climate sensitivity for doubled CO2 concentrations of about 3 C. The 2×CO2 Earth system sensitivity is higher than this, being approx. 4-6 C if the ice sheet/vegetation albedo feedback is included in addition to the fast feedbacks, and higher still if climate-GHG feedbacks are also included. The inclusion of climate-GHG feedbacks due to changes in the natural carbon sinks has the advantage of more directly linking anthropogenic GHG emissions with the ensuing global temperature increase, thus providing a truer indication of the climate sensitivity to human perturbations. The Earth system climate sensitivity is difficult to quantify due to the lack of palaeo-analogues for the present-day anthropogenic forcing, and the fact that ice sheet and climate-GHG feedbacks have yet to become globally significant in the Anthropocene. Furthermore, current models are unable to adequately simulate the physics of ice sheet decay and certain aspects of the natural carbon and

  13. Olfactory sensitivity in mammalian species.

    PubMed

    Wackermannová, M; Pinc, L; Jebavý, L

    2016-07-18

    Olfaction enables most mammalian species to detect and discriminate vast numbers of chemical structures called odorants and pheromones. The perception of such chemical compounds is mediated via two major olfactory systems, the main olfactory system and the vomeronasal system, as well as minor systems, such as the septal organ and the Grueneberg ganglion. Distinct differences exist not only among species but also among individuals in terms of their olfactory sensitivity; however, little is known about the mechanisms that determine these differences. In research on the olfactory sensitivity of mammals, scientists thus depend in most cases on behavioral testing. In this article, we reviewed scientific studies performed on various mammalian species using different methodologies and target chemical substances. Human and non-human primates as well as rodents and dogs are the most frequently studied species. Olfactory threshold studies on other species do not exist with the exception of domestic pigs. Olfactory testing performed on seals, elephants, and bats focused more on discriminative abilities than on sensitivity. An overview of olfactory sensitivity studies as well as olfactory detection ability in most studied mammalian species is presented here, focusing on comparable olfactory detection thresholds. The basics of olfactory perception and olfactory sensitivity factors are also described. PMID:27070753

  14. Phase-sensitive flow cytometer

    SciTech Connect

    Steinkamp, J.A.

    1992-12-31

    This report describes phase-sensitive flow cytometer (FCM) which provides additional FCM capability to use the fluorescence lifetime of one or more fluorochromes bound to single cells to provide additional information regarding the cells. The resulting fluorescence emission can be resolved into individual fluorescence signals if two fluorochromes are present or can be converted directly to a decay lifetime from a single fluorochrome. The excitation light for the fluorochromes is modulated to produce an amplitude modulated fluorescence pulse as the fluorochrome is excited in the FCM. The modulation signal also forms a reference signal that is phase-shifted a selected amount for subsequent mixing with the output modulated fluorescence intensity signal in phase-sensitive detection circuitry. The output from the phase-sensitive circuitry is then an individual resolved fluorochrome signal or a single fluorochrome decay lifetime, depending on the applied phase shifts.

  15. Making Sense of Palaeoclimate Sensitivity

    NASA Technical Reports Server (NTRS)

    Rohling, E. J.; Sluijs, A.; DeConto, R.; Drijfhout, S. S.; Fedorov, A.; Foster, G. L.; Ganopolski, A.; Hansen, J.; Honisch, B.; Hooghiemstra, H.; Huber, M.; Huybers, P.; Dijkstra, H. A.; Knutti, R.; Lea, D. W.; Lourens, L. J.; Lunt, D.; Masson-Delmotte, V.; Medina-Elizalde, M.; Otto-Bliesner, B.; Pagani, M.; Palike, H.; Renssen, H.; Koehler, P.; Royer, D. L.; Siddall, M.; Valdes, P.; Zachos, J. C.; Zeebe, R. E.; vandeWal, R. S. W.; vonderHeydt, A. S.; Beerling, D. J.; Berger, A.; Bijl, P. K.; Crucifix, M.

    2012-01-01

    Many palaeoclimate studies have quantified pre-anthropogenic climate change to calculate climate sensitivity (equilibrium temperature change in response to radiative forcing change), but a lack of consistent methodologies produces a wide range of estimates and hinders comparability of results. Here we present a stricter approach, to improve intercomparison of palaeoclimate sensitivity estimates in a manner compatible with equilibrium projections for future climate change. Over the past 65 million years, this reveals a climate sensitivity (in K W-1 m2) of 0.3-1.9 or 0.6-1.3 at 95% or 68% probability, respectively. The latter implies a warming of 2.2-4.8 K per doubling of atmospheric CO2, which agrees with IPCC estimates.

  16. Phase-sensitive flow cytometer

    DOEpatents

    Steinkamp, John A.

    1993-01-01

    A phase-sensitive flow cytometer (FCM) provides additional FCM capability to use the fluorescence lifetime of one or more fluorochromes bound to single cells to provide additional information regarding the cells. The resulting fluorescence emission can be resolved into individual fluorescence signals if two fluorochromes are present or can be converted directly to a decay lifetime from a single fluorochrome. The excitation light for the fluorochromes is modulated to produce an amplitude modulated fluorescence pulse as the fluorochrome is excited in the FCM. The modulation signal also forms a reference signal that is phase-shifted a selected amount for subsequent mixing with the output modulated fluorescence intensity signal in phase-sensitive detection circuitry. The output from the phase-sensitive circuitry is then an individual resolved fluorochrome signal or a single fluorochrome decay lifetime, depending on the applied phase shifts.

  17. Phase-sensitive flow cytometer

    DOEpatents

    Steinkamp, J.A.

    1993-12-14

    A phase-sensitive flow cytometer (FCM) provides additional FCM capability to use the fluorescence lifetime of one or more fluorochromes bound to single cells to provide additional information regarding the cells. The resulting fluorescence emission can be resolved into individual fluorescence signals if two fluorochromes are present or can be converted directly to a decay lifetime from a single fluorochrome. The excitation light for the fluorochromes is modulated to produce an amplitude modulated fluorescence pulse as the fluorochrome is excited in the FCM. The modulation signal also forms a reference signal that is phase-shifted a selected amount for subsequent mixing with the output modulated fluorescence intensity signal in phase-sensitive detection circuitry. The output from the phase-sensitive circuitry is then an individual resolved fluorochrome signal or a single fluorochrome decay lifetime, depending on the applied phase shifts. 15 figures.

  18. Uncertainty and Sensitivity Analyses Plan

    SciTech Connect

    Simpson, J.C.; Ramsdell, J.V. Jr.

    1993-04-01

    Hanford Environmental Dose Reconstruction (HEDR) Project staff are developing mathematical models to be used to estimate the radiation dose that individuals may have received as a result of emissions since 1944 from the US Department of Energy's (DOE) Hanford Site near Richland, Washington. An uncertainty and sensitivity analyses plan is essential to understand and interpret the predictions from these mathematical models. This is especially true in the case of the HEDR models where the values of many parameters are unknown. This plan gives a thorough documentation of the uncertainty and hierarchical sensitivity analysis methods recommended for use on all HEDR mathematical models. The documentation includes both technical definitions and examples. In addition, an extensive demonstration of the uncertainty and sensitivity analysis process is provided using actual results from the Hanford Environmental Dose Reconstruction Integrated Codes (HEDRIC). This demonstration shows how the approaches used in the recommended plan can be adapted for all dose predictions in the HEDR Project.

  19. Making sense of palaeoclimate sensitivity.

    PubMed

    2012-11-29

    Many palaeoclimate studies have quantified pre-anthropogenic climate change to calculate climate sensitivity (equilibrium temperature change in response to radiative forcing change), but a lack of consistent methodologies produces a wide range of estimates and hinders comparability of results. Here we present a stricter approach, to improve intercomparison of palaeoclimate sensitivity estimates in a manner compatible with equilibrium projections for future climate change. Over the past 65 million years, this reveals a climate sensitivity (in K W(-1) m(2)) of 0.3-1.9 or 0.6-1.3 at 95% or 68% probability, respectively. The latter implies a warming of 2.2-4.8 K per doubling of atmospheric CO(2), which agrees with IPCC estimates. PMID:23192145

  20. Dye Sensitized Tandem Photovoltaic Cells

    SciTech Connect

    Barber, Greg D.

    2009-12-21

    This work provided a new way to look at photoelectrochemical cells and their performance. Although thought of as low efficiency, a the internal efficiency of a 9% global efficiency dye sensitized solar cell is approximately equal to an 18% efficient silicon cell when each is compared to their useful spectral range. Other work undertaken with this contract also reported the first growth oriented titania and perovskite columns on a transparent conducting oxide. Other work has shown than significant performance enhancement in the performance of dye sensitized solar cells can be obtained through the use of coupling inverse opal photonic crystals to the nanocrystalline dye sensitized solar cell. Lastly, a quick efficient method was developed to bond titanium foils to transparent conducting oxide substrates for anodization.

  1. Nano-textured high sensitivity ion sensitive field effect transistors

    NASA Astrophysics Data System (ADS)

    Hajmirzaheydarali, M.; Sadeghipari, M.; Akbari, M.; Shahsafi, A.; Mohajerzadeh, S.

    2016-02-01

    Nano-textured gate engineered ion sensitive field effect transistors (ISFETs), suitable for high sensitivity pH sensors, have been realized. Utilizing a mask-less deep reactive ion etching results in ultra-fine poly-Si features on the gate of ISFET devices where spacing of the order of 10 nm and less is achieved. Incorporation of these nano-sized features on the gate is responsible for high sensitivities up to 400 mV/pH in contrast to conventional planar structures. The fabrication process for this transistor is inexpensive, and it is fully compatible with standard complementary metal oxide semiconductor fabrication procedure. A theoretical modeling has also been presented to predict the extension of the diffuse layer into the electrolyte solution for highly featured structures and to correlate this extension with the high sensitivity of the device. The observed ultra-fine features by means of scanning electron microscopy and transmission electron microscopy tools corroborate the theoretical prediction.

  2. Lessening Sensitivity: Student Experiences of Teaching and Learning Sensitive Issues

    ERIC Educational Resources Information Center

    Lowe, Pam

    2015-01-01

    Despite growing interest in learning and teaching as emotional activities, there is still very little research on experiences of sensitive issues. Using qualitative data from students from a range of social science disciplines, this study investigates student's experiences. The paper highlights how, although they found it difficult and…

  3. Cortical mechanisms of cocaine sensitization.

    PubMed

    Steketee, Jeffery D

    2005-01-01

    Behavioral sensitization is the augmented motor-stimulant response that occurs with repeated, intermittent exposure to most drugs of abuse, including cocaine. Sensitization, which is a long-lasting phenomenon, is thought to underlie drug craving and relapse to drug use. Much research has been conducted to determine the neural mechanisms of sensitization. The bulk of this effort has focused on the nucleus accumbens and ventral tegmental area (VTA) that comprise a portion of the mesolimbic dopamine system. Recently, studies have begun to also explore the role of the medial prefrontal cortex (mPFC) in sensitization, in part because this region provides glutamatergic innervation to the VTA and nucleus accumbens. The present review will coalesce these studies into a working hypothesis that states that cocaine sensitization results from a decrease in inhibitory modulation of excitatory transmission from the mPFC to the VTA and nucleus accumbens. The discussion will revolve around how repeated cocaine exposure alters dopamine, gamma-aminobutyric acid (GABA), and glutamate regulation of pyramidal cell activity. It will be proposed that cocaine-induced alterations in cortical transmission occur in two phases. During early withdrawal from repeated cocaine exposure, changes in neurotransmitter release are thought to underlie the decreased inhibitory modulation of pyramidal projection neurons. Following more prolonged withdrawal, the attenuation in inhibitory transmission appears to occur at the receptor level. A model will be presented that may serve to direct future studies on the involvement of the mPFC in the development of cocaine sensitization, which ultimately could lead to development of pharmacotherapies for cocaine addiction. PMID:16808728

  4. Porphyrin-sensitized solar cells.

    PubMed

    Li, Lu-Lin; Diau, Eric Wei-Guang

    2013-01-01

    Nature has chosen chlorophylls in plants as antennae to harvest light for the conversion of solar energy in complicated photosynthetic processes. Inspired by natural photosynthesis, scientists utilized artificial chlorophylls - the porphyrins - as efficient centres to harvest light for solar cells sensitized with a porphyrin (PSSC). After the first example appeared in 1993 of a porphyrin of type copper chlorophyll as a photosensitizer for PSSC that achieved a power conversion efficiency of 2.6%, no significant advance of PSSC was reported until 2005; beta-linked zinc porphyrins were then reported to show promising device performances with a benchmark efficiency of 7.1% reported in 2007. Meso-linked zinc porphyrin sensitizers in the first series with a push-pull framework appeared in 2009; the best cell performed comparably to that of a N3-based device, and a benchmark 11% was reported for a porphyrin sensitizer of this type in 2010. With a structural design involving long alkoxyl chains to envelop the porphyrin core to suppress the dye aggregation for a push-pull zinc porphyrin, the PSSC achieved a record 12.3% in 2011 with co-sensitization of an organic dye and a cobalt-based electrolyte. The best PSSC system exhibited a panchromatic feature for light harvesting covering the visible spectral region to 700 nm, giving opportunities to many other porphyrins, such as fused and dimeric porphyrins, with near-infrared absorption spectral features, together with the approach of molecular co-sensitization, to enhance the device performance of PSSC. According to this historical trend for the development of prospective porphyrin sensitizers used in PSSC, we review systematically the progress of porphyrins of varied kinds, and their derivatives, applied in PSSC with a focus on reports during 2007-2012 from the point of view of molecular design correlated with photovoltaic performance. PMID:23023240

  5. An analysis of sensitivity tests

    SciTech Connect

    Neyer, B.T.

    1992-03-06

    A new method of analyzing sensitivity tests is proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions for the parameters of the distribution (e.g., the mean, {mu}, and the standard deviation, {sigma}) as well as various percentiles. Unlike presently used methods, such as those based on asymptotic analysis, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The main disadvantage of this method is that it requires much more computation to calculate the confidence regions. However, these calculations can be easily and quickly performed on most computers.

  6. Sensitive, Selective Test For Hydrazines

    NASA Technical Reports Server (NTRS)

    Roundbehler, David; Macdonald, Stephen

    1993-01-01

    Derivatives of hydrazines formed, then subjected to gas chromatography and detected via chemiluminescence. In method of detecting and quantifying hydrazine vapors, vapors reacted with dinitro compound to enhance sensitivity and selectivity. Hydrazine (HZ), monomethyl hydrazine, (MMH), and unsymmetrical dimethylhydrazine (UDMH) analyzed quantitatively and qualitatively, either alone or in mixtures. Vapors collected and reacted with 2,4-dinitrobenzaldehyde, (DNB), making it possible to concentrate hydrazine in derivative form, thereby increasing sensitivity to low initial concentrations. Increases selectivity because only those constituents of sample reacting with DNB concentrated for analysis.

  7. High sensitive airborne radioiodine monitor.

    PubMed

    Ogata, Yoshimune; Yamasaki, Tadashi; Hanafusa, Ryuji

    2013-11-01

    Airborne radioiodine monitoring includes a problem in that commercial radioactive gas monitors have inadequate sensitivity. To solve this problem, we designed a highly sensitive monitoring system. The higher counting efficiency and lower background made it possible to perform the low-level monitoring. The characteristics of the system were investigated using gaseous (125)I. The minimum detectable activity concentration was 1 × 10(-4)Bq cm(-3) for 1 min counting, which is one tenth of the legal limit for the radiation controlled areas in Japan. PMID:23602709

  8. Drought sensitivity predicts habitat size sensitivity in an aquatic ecosystem.

    PubMed

    Amundrud, Sarah L; Srivastava, Diane S

    2015-07-01

    Species and trophic richness often increase with habitat size. Although many ecological processes have been evoked to explain both patterns, the environmental stress associated with small habitats has rarely been considered. We propose that larger habitats may be species rich simply because their environmental conditions are within the fundamental niche of more species; larger habitats may also have more trophic levels if traits of predators render them vulnerable to environmental stress. We test this hypothesis using the aquatic insect larvae in water-filled bromeliads. In bromeliads, the probability of desiccation is greatest in small plants. For the 10 most common bromeliad insect taxa, we ask whether differences in drought tolerance and regional abundances between taxa predict community and trophic composition over a gradient of bromeliad size. First, we used bromeliad survey data to calculate the mean habitat size of occurrence of each taxon. Comparing the observed mean habitat size of occurrence to that expected from random species assembly based on differences in their regional abundances allowed us to obtain habitat size sensitivity indices (as Z scores) for the various insect taxa. Second, we obtained drought sensitivity indices by subjecting individual insects to drought and measuring the effects on relative growth rates in a mesocosm experiment. We found that drought sensitivity strongly, predicts habitat size sensitivity in bromeliad insects. However, an increase in trophic richness with habitat size could not be explained by an increased sensitivity of predators to drought, but rather by sampling effects, as predators were rare compared to lower trophic levels. This finding suggests that physiological tolerance to environmental stress can be relevant in explaining the universal increase in species with habitat size. PMID:26378317

  9. Contextual sensitivity in scientific reproducibility.

    PubMed

    Van Bavel, Jay J; Mende-Siedlecki, Peter; Brady, William J; Reinero, Diego A

    2016-06-01

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher's degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed "hidden moderators") between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility. PMID:27217556

  10. Towards Context Sensitive Information Inference.

    ERIC Educational Resources Information Center

    Song, D.; Bruza, P. D.

    2003-01-01

    Discusses information inference from a psychologistic stance and proposes an information inference mechanism that makes inferences via computations of information flow through an approximation of a conceptual space. Highlights include cognitive economics of information processing; context sensitivity; and query models for information retrieval.…

  11. High-Sensitivity Microwave Optics.

    ERIC Educational Resources Information Center

    Nunn, W. M., Jr.

    1981-01-01

    Describes a 3.33-cm wavelength (9 GHz) microwave system that achieves a high overall signal sensitivity and a well-collimated beam with moderate-size equipment. The system has been used to develop microwave versions of the Michelson interferometer, Bragg reflector, Brewster's law and total internal reflection, and Young's interference experiment.…

  12. Sensitivity Training in the Classroom.

    ERIC Educational Resources Information Center

    Cameron, Brent

    1970-01-01

    Sensitivity training in the classroom can help children cope with and adapt to their environment--family, peer group, friends, school, and teachers--and get them to talk honestly and openly about emotional, social, and intellectual feelings and concepts. Some techniques of encouraging students to explore, to become involved with and aware of…

  13. Noise sensitivity: A neurophenomenological perspective.

    PubMed

    Dzhambov, Angel M

    2015-11-01

    This paper addresses the current limitations of noise sensitivity research and the benefit of undertaking a neurophenomenological approach of investigation. It begins by questioning the invariance of noise sensitivity across different studies and contexts and argues that these are issues associated with the psychometric construct rather than the underlying reaction patterns. It suggest that our definition and operationalization of noise sensitivity might have been misspecified and that it needs to be revised on the basis of heuristically derived first-person data about our experiences of noise. It then shows why the basic principles of the neurophenomenological program are applicable to psychoacoustic research. Namely, it argues that phenomenological training leading to reflexive introspection and verbalization of our susceptibility to noise might have three-fold implication - (i) it will generate deeper understanding of noise sensitivity which will then allow us to deduce a hierarchical structure of meaning and concepts to supplement and be fed to quantitative research, (ii) it will provide better interpretation of neuroimaging and electroencephalographic data related to noise reaction and perception, which in turn will allow a process of reciprocal validation, (iii) and, most importantly, it presents a promising technique for emotional regulation of noise processing via modulation of the amygdalar function, when a state of awareness of this processing has been achieved. PMID:26315447

  14. Pea Plants Show Risk Sensitivity.

    PubMed

    Dener, Efrat; Kacelnik, Alex; Shemesh, Hagai

    2016-07-11

    Sensitivity to variability in resources has been documented in humans, primates, birds, and social insects, but the fit between empirical results and the predictions of risk sensitivity theory (RST), which aims to explain this sensitivity in adaptive terms, is weak [1]. RST predicts that agents should switch between risk proneness and risk aversion depending on state and circumstances, especially according to the richness of the least variable option [2]. Unrealistic assumptions about agents' information processing mechanisms and poor knowledge of the extent to which variability imposes specific selection in nature are strong candidates to explain the gap between theory and data. RST's rationale also applies to plants, where it has not hitherto been tested. Given the differences between animals' and plants' information processing mechanisms, such tests should help unravel the conflicts between theory and data. Measuring root growth allocation by split-root pea plants, we show that they favor variability when mean nutrient levels are low and the opposite when they are high, supporting the most widespread RST prediction. However, the combination of non-linear effects of nitrogen availability at local and systemic levels may explain some of these effects as a consequence of mechanisms not necessarily evolved to cope with variance [3, 4]. This resembles animal examples in which properties of perception and learning cause risk sensitivity even though they are not risk adaptations [5]. PMID:27374342

  15. Cinnamon, glucose and insulin sensitivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Compounds found in cinnamon not only improve the function of insulin but also function as antioxidants and may be anti-inflammatory. This is very important since insulin function, antioxidant status, and inflammatory response are closely linked; with decreased insulin sensitivity there is also decr...

  16. Contamination Sensitivity in Young Children.

    ERIC Educational Resources Information Center

    Siegal, Michael; Share, David L.

    1990-01-01

    Revealed that children were able to indicate that an apparently safe substance such as juice may be contaminated by contact with a foreign body such as a cockroach. Supported the hypothesis that early sensitivity to substances that contain invisible contaminates may be guided by knowledge of a distinction between appearance and reality. (RH)

  17. Conducting Surveys on Sensitive Topics

    ERIC Educational Resources Information Center

    Pryor, John H.

    2004-01-01

    Many institutions are surveying students about sensitive topics such as alcohol and drug use, sexual behavior, and academic dishonesty. Yet these can be some of the most difficult surveys to administer successfully, given reluctance on the part of respondents both to participate and to provide truthful answers. (Contains 1 table.)

  18. A Primer of Covert Sensitization

    ERIC Educational Resources Information Center

    Kearney, Albert J.

    2006-01-01

    Covert sensitization is the first of a family of behavior therapy procedures called covert conditioning initially developed by Joseph Cautela in the 1960s and 1970s. The covert conditioning procedures involve the use of visualized imagery and are designed to work according to operant conditioning principles. When working with cooperative clients…

  19. Tactile Sensitivity in Asperger Syndrome

    ERIC Educational Resources Information Center

    Blakemore, Sarah-Jayne; Tavassoli, Teresa; Calo, Susana; Thomas, Richard M.; Catmur, Caroline; Frith, Uta; Haggard, Patrick

    2006-01-01

    People with autism and Asperger syndrome are anecdotally said to be hypersensitive to touch. In two experiments, we measured tactile thresholds and suprathreshold tactile sensitivity in a group of adults with Asperger syndrome. In the first experiment, tactile perceptual thresholds were measured. Two frequencies of vibrotactile stimulation were…

  20. The polarization sensitivity of GRETINA

    NASA Astrophysics Data System (ADS)

    Wiens, Andreas; Gretina Collaboration

    2014-09-01

    The new tracking array GRETINA provides position information of the individual interactions of γ rays within the active Ge detector material. The position knowledge of the first two interaction points enables the calculation of the Compton scattering angle, which is sensitive to the linear polarization. Measuring the angular distribution and the linear polarization can help determine the electromagnetic character of a transition and its parity. Inelastic proton scattering on Mg (24 Mg (p , p ' γ)) provides highly polarized γ rays which we used to characterize the polarization sensitivity of GRETINA. We have studied the angular distribution and the azimuthal Compton scattering angle of the 1368 keV gamma transition after signal-decomposition and tracking, which were normalized with the unpolarized results derived from 60 Co . The a2 and a4 coefficients from the Legendre Polynomial fit of the angular distribution confirmed the high degree of polarization. We will report on the asymmetry in the azimuthal Compton scattering angle distribution which is in good agreement with a cos (2 φ) fit. We will discuss the energy dependance of the polarization sensitivity and compare the results with a GEANT4 simulation. The new tracking array GRETINA provides position information of the individual interactions of γ rays within the active Ge detector material. The position knowledge of the first two interaction points enables the calculation of the Compton scattering angle, which is sensitive to the linear polarization. Measuring the angular distribution and the linear polarization can help determine the electromagnetic character of a transition and its parity. Inelastic proton scattering on Mg (24 Mg (p , p ' γ)) provides highly polarized γ rays which we used to characterize the polarization sensitivity of GRETINA. We have studied the angular distribution and the azimuthal Compton scattering angle of the 1368 keV gamma transition after signal-decomposition and tracking

  1. Space transportation architecture: Reliability sensitivities

    NASA Technical Reports Server (NTRS)

    Williams, A. M.

    1992-01-01

    A sensitivity analysis is given of the benefits and drawbacks associated with a proposed Earth to orbit vehicle architecture. The architecture represents a fleet of six vehicles (two existing, four proposed) that would be responsible for performing various missions as mandated by NASA and the U.S. Air Force. Each vehicle has a prescribed flight rate per year for a period of 31 years. By exposing this fleet of vehicles to a probabilistic environment where the fleet experiences failures, downtimes, setbacks, etc., the analysis involves determining the resiliency and costs associated with the fleet of specific vehicle/subsystem reliabilities. The resources required were actual observed data on the failures and downtimes associated with existing vehicles, data based on engineering judgement for proposed vehicles, and the development of a sensitivity analysis program.

  2. Habituation, sensitization, and Pavlovian conditioning

    PubMed Central

    Çevik, Münire Özlem

    2014-01-01

    In this brief review, I argue that the impact of a stimulus on behavioral control increase as the distance of the stimulus to the body decreases. Habituation, i.e., decrement in response intensity repetition of the triggering stimulus, is the default state for sensory processing, and the likelihood of habituation is higher for distal stimuli. Sensitization, i.e., increment in response intensity upon stimulus repetition, occurs in a state dependent manner for proximal stimuli that make direct contact with the body. In Pavlovian conditioning paradigms, the unconditioned stimulus (US) is always a more proximal stimulus than the conditioned stimulus (CS). The mechanisms of associative and non-associative learning are not independent. CS−US pairings lead to formation of associations if sensitizing modulation from a proximal US prevents the habituation for a distal anticipatory CS. PMID:24574983

  3. Habituation, sensitization, and Pavlovian conditioning.

    PubMed

    Cevik, Münire Özlem

    2014-01-01

    In this brief review, I argue that the impact of a stimulus on behavioral control increase as the distance of the stimulus to the body decreases. Habituation, i.e., decrement in response intensity repetition of the triggering stimulus, is the default state for sensory processing, and the likelihood of habituation is higher for distal stimuli. Sensitization, i.e., increment in response intensity upon stimulus repetition, occurs in a state dependent manner for proximal stimuli that make direct contact with the body. In Pavlovian conditioning paradigms, the unconditioned stimulus (US) is always a more proximal stimulus than the conditioned stimulus (CS). The mechanisms of associative and non-associative learning are not independent. CS-US pairings lead to formation of associations if sensitizing modulation from a proximal US prevents the habituation for a distal anticipatory CS. PMID:24574983

  4. Sensitivity of VIIRS Polarization Measurements

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene

    2010-01-01

    The design of an optical system typically involves a sensitivity analysis where the various lens parameters, such as lens spacing and curvatures, to name two parameters, are (slightly) varied to see what, if any, effect this has on the performance and to establish manufacturing tolerances. A sinular analysis was performed for the VIIRS instruments polarization measurements to see how real world departures from perfectly linearly polarized light entering VIIRS effects the polarization measurement. The methodology and a few of the results of this polarization sensitivity analysis are presented and applied to the construction of a single polarizer which will cover the VIIRS VIS/NIR spectral range. Keywords: VIIRS, polarization, ray, trace; polarizers, Bolder Vision, MOXTEK

  5. Accuracy of Pressure Sensitive Paint

    NASA Technical Reports Server (NTRS)

    Liu, Tianshu; Guille, M.; Sullivan, J. P.

    2001-01-01

    Uncertainty in pressure sensitive paint (PSP) measurement is investigated from a standpoint of system modeling. A functional relation between the imaging system output and luminescent emission from PSP is obtained based on studies of radiative energy transports in PSP and photodetector response to luminescence. This relation provides insights into physical origins of various elemental error sources and allows estimate of the total PSP measurement uncertainty contributed by the elemental errors. The elemental errors and their sensitivity coefficients in the error propagation equation are evaluated. Useful formulas are given for the minimum pressure uncertainty that PSP can possibly achieve and the upper bounds of the elemental errors to meet required pressure accuracy. An instructive example of a Joukowsky airfoil in subsonic flows is given to illustrate uncertainty estimates in PSP measurements.

  6. Structural optimization with approximate sensitivities

    NASA Technical Reports Server (NTRS)

    Patnaik, S. N.; Hopkins, D. A.; Coroneos, R.

    1994-01-01

    Computational efficiency in structural optimization can be enhanced if the intensive computations associated with the calculation of the sensitivities, that is, gradients of the behavior constraints, are reduced. Approximation to gradients of the behavior constraints that can be generated with small amount of numerical calculations is proposed. Structural optimization with these approximate sensitivities produced correct optimum solution. Approximate gradients performed well for different nonlinear programming methods, such as the sequence of unconstrained minimization technique, method of feasible directions, sequence of quadratic programming, and sequence of linear programming. Structural optimization with approximate gradients can reduce by one third the CPU time that would otherwise be required to solve the problem with explicit closed-form gradients. The proposed gradient approximation shows potential to reduce intensive computation that has been associated with traditional structural optimization.

  7. Light sensitivity of methanogenic archaebacteria

    SciTech Connect

    Olson, K.D.; McMahon, C.W.; Wolfe, R.S. )

    1991-09-01

    Representatives of four families of methanogenic archaebacteria (archaea), Methanobacterium thermoautotrophicum {Delta}H, Methanobacterium thermoautotrophicum Marburg, Methanosarcina acetivorans, Methanococcus voltae, and Methanomicrobium mobile, were found to be light sensitive. The facultative anaerobic eubacteria Escherichia coli and Salmonella typhimurium, however, were tolerant of light when grown anaerobically under identical light conditions. Interference filters were used to show that the growth of the methanogens is inhibited by light in the blue end of the visible spectrum (370 to 430 nm).

  8. Trace Elements and Chemotherapy Sensitivity.

    PubMed

    Liu, Zhihui; Yang, Weiping; Long, Gang; Wei, Changyuan

    2016-10-01

    Trace elements might be associated with the development of hepatocellular carcinoma (HCC) and the efficacy of chemotherapy against HCC. Therefore, this study aimed to explore the association between trace elements and efficacy of chemotherapy in patients with HCC. Cancer, cancer-adjacent, and cancer-free tissues were collected intraoperatively from 55 patients with HCC between January 2001 and April 2004 at the Affiliated Tumor Hospital of Guangxi Medical University in Guangxi (China), a high HCC incidence area in the world. Trace element levels were analyzed by atomic absorption spectrophotometry. In vitro sensitivity of cancer cells to five chemotherapeutic drugs (5-fluorouracil, doxorubicin, cisplatin, carboplatin, and mitomycin) was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in cancer cells from 32 patients. Zinc, copper, manganese, and selenium levels had the same gradient distribution in different liver tissues: cancer < cancer-adjacent < cancer-free tissues. Copper levels of cancer tissues were negatively correlated with body weight (r = -0.278, P = 0.027), while manganese and selenium levels were negatively correlated with age (r = -0.297, P = 0.015; r = -0.285, P = 0.018, respectively). Simple correlation analyses revealed that the carboplatin sensitivity was negatively correlated with selenium levels of cancer tissues, while doxorubicin sensitivity was negatively correlated with manganese levels (r = -0.497, P = 0.004). Partial correlation analyses showed that doxorubicin sensitivity only was negatively correlated with manganese levels (r = -0.450, P = 0.014). These results suggest that the selenium and manganese content in primary HCC tissues could influence the response of the HCC cells to carboplatin and doxorubicin. These preliminary results provide a basis for future studies. PMID:26961293

  9. Gravitational-wave sensitivity curves

    NASA Astrophysics Data System (ADS)

    Moore, C. J.; Cole, R. H.; Berry, C. P. L.

    2015-01-01

    There are several common conventions in use by the gravitational-wave community to describe the amplitude of sources and the sensitivity of detectors. These are frequently confused. We outline the merits of and differences between the various quantities used for parameterizing noise curves and characterizing gravitational-wave amplitudes. We conclude by producing plots that consistently compare different detectors. Similar figures can be generated on-line for general use at http://rhcole.com/apps/GWplotter.

  10. Zebrafish Sensitivity to Botulinum Neurotoxins.

    PubMed

    Chatla, Kamalakar; Gaunt, Patricia S; Petrie-Hanson, Lora; Ford, Lorelei; Hanson, Larry A

    2016-01-01

    Botulinum neurotoxins (BoNT) are the most potent known toxins. The mouse LD50 assay is the gold standard for testing BoNT potency, but is not sensitive enough to detect the extremely low levels of neurotoxin that may be present in the serum of sensitive animal species that are showing the effects of BoNT toxicity, such as channel catfish affected by visceral toxicosis of catfish. Since zebrafish are an important animal model for diverse biomedical and basic research, they are readily available and have defined genetic lines that facilitate reproducibility. This makes them attractive for use as an alternative bioassay organism. The utility of zebrafish as a bioassay model organism for BoNT was investigated. The 96 h median immobilizing doses of BoNT/A, BoNT/C, BoNT/E, and BoNT/F for adult male Tübingen strain zebrafish (0.32 g mean weight) at 25 °C were 16.31, 124.6, 4.7, and 0.61 picograms (pg)/fish, respectively. These findings support the use of the zebrafish-based bioassays for evaluating the presence of BoNT/A, BoNT/E, and BoNT/F. Evaluating the basis of the relatively high resistance of zebrafish to BoNT/C and the extreme sensitivity to BoNT/F may reveal unique functional patterns to the action of these neurotoxins. PMID:27153088

  11. Sensitivity of coded mask telescopes.

    PubMed

    Skinner, Gerald K

    2008-05-20

    Simple formulas are often used to estimate the sensitivity of coded mask x-ray or gamma-ray telescopes, but these are strictly applicable only if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask, or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given that allows the calculation of the sensitivity. We consider certain aspects of the optimization of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels. PMID:18493279

  12. Overview of low temperature sensitization

    SciTech Connect

    Fox, M.J.; McCright, R.D.

    1983-12-01

    A review of the literature on low temperature sensitization (LTS) has been conducted to determine if LTS-related microstructural changes can occur in Type 304L stainless steel within the times and temperatures associated with nuclear waste storage. It was found that Type 304L stainless steel is susceptible to sensitization and LTS, and that cold work plays an important role in determining the rate of LTS. Severely cold worked Type 304L stainless steel would clearly develop LTS-related microstructural changes within the times and temperatures associated with nuclear waste storage. These changes could lead to increased susceptibility to corrosion. Significant improvements in the long-term resistance to sensitization, LTS and corrosion can be achieved by modest changes in alloy composition and fabrication practices. Therefore, Type 304L would not be the preferred alloy of construction for nuclear waste storage canisters. The final qualification of an alternate canister alloy should involve corrosion experiments on actual canisters. Suggestions for alternate canister alloys are 316L, 316LN, 316ELC, 347, and XM-19. 47 references, 4 figures.

  13. Zebrafish Sensitivity to Botulinum Neurotoxins

    PubMed Central

    Chatla, Kamalakar; Gaunt, Patricia S.; Petrie-Hanson, Lora; Ford, Lorelei; Hanson, Larry A.

    2016-01-01

    Botulinum neurotoxins (BoNT) are the most potent known toxins. The mouse LD50 assay is the gold standard for testing BoNT potency, but is not sensitive enough to detect the extremely low levels of neurotoxin that may be present in the serum of sensitive animal species that are showing the effects of BoNT toxicity, such as channel catfish affected by visceral toxicosis of catfish. Since zebrafish are an important animal model for diverse biomedical and basic research, they are readily available and have defined genetic lines that facilitate reproducibility. This makes them attractive for use as an alternative bioassay organism. The utility of zebrafish as a bioassay model organism for BoNT was investigated. The 96 h median immobilizing doses of BoNT/A, BoNT/C, BoNT/E, and BoNT/F for adult male Tübingen strain zebrafish (0.32 g mean weight) at 25 °C were 16.31, 124.6, 4.7, and 0.61 picograms (pg)/fish, respectively. These findings support the use of the zebrafish-based bioassays for evaluating the presence of BoNT/A, BoNT/E, and BoNT/F. Evaluating the basis of the relatively high resistance of zebrafish to BoNT/C and the extreme sensitivity to BoNT/F may reveal unique functional patterns to the action of these neurotoxins. PMID:27153088

  14. Dye-sensitized solar cells

    DOEpatents

    Skotheim, T.A.

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

  15. Dye-sensitized solar cells

    DOEpatents

    Skotheim, Terje A. [Berkeley, CA

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  16. Sensitized Liquid Hydrazine Detonation Studies

    NASA Technical Reports Server (NTRS)

    Rathgeber, K. A.; Keddy, C. P.; Bunker, R. L.

    1999-01-01

    Vapor-phase hydrazine (N2H4) is known to be very sensitive to detonation while liquid hydrazine is very insensitive to detonation, theoretically requiring extremely high pressures to induce initiation. A review of literature on solid and liquid explosives shows that when pure explosive substances are infiltrated with gas cavities, voids, and/or different phase contaminants, the energy or shock pressure necessary to induce detonation can decrease by an order of magnitude. Tests were conducted with liquid hydrazine in a modified card-gap configuration. Sensitization was attempted by bubbling helium gas through and/or suspending ceramic microspheres in the liquid. The hydrazine was subjected to the shock pressure from a 2 lb (0.9 kg) Composition C-4 explosive charge. The hydrazine was contained in a 4 in. (10.2 cm) diameter stainless steel cylinder with a 122 in(sup 3) (2 L) volume and sealed with a polyethylene cap. Blast pressures from the events were recorded by 63 high speed pressure transducers located on three radial legs extending from 4 to 115 ft (1.2 to 35.1 in) from ground zero. Comparison of the neat hydrazine and water baseline tests with the "sensitized" hydrazine tests indicates the liquid hydrazine did not detonate under these conditions.

  17. Fast Neutron Sensitivity with HPGe

    SciTech Connect

    Seifert, Allen; Hensley, Walter K.; Siciliano, Edward R.; Pitts, W. K.

    2008-01-22

    In addition to being excellent gamma-ray detectors, germanium detectors are also sensitive to fast neutrons. Incident neutrons undergo inelastic scattering {Ge(n,n')Ge*} off germanium nuclei and the resulting excited states emit gamma rays or conversion electrons. The response of a standard 140% high-purity germanium (HPGe) detector with a bismuth germanate (BGO) anti-coincidence shield was measured for several neutron sources to characterize the ability of the HPGe detector to detect fast neutrons. For a sensitivity calculation performed using the characteristic fast neutron response peak that occurs at 692 keV, the 140% germanium detector system exhibited a sensitivity of ~175 counts / kg of WGPumetal in 1000 seconds at a source-detector distance of 1 meter with 4 in. of lead shielding between source and detector. Theoretical work also indicates that it might be possible to use the shape of the fast-neutron inelastic scattering signatures (specifically, the end-point energy of the long high energy tail of the resulting asymmetric peak) to gain additional information about the energy distribution of the incident neutron spectrum. However, the experimentally observed end-point energies appear to be almost identical for each of the fast neutron sources counted. Detailed MCNP calculations show that the neutron energy distributions impingent on the detector for these sources are very similar in this experimental configuration, due to neutron scattering in a lead shield (placed between the neutron source and HPGe detector to reduce the gamma ray flux), the BGO anti-coincidence detector, and the concrete floor.

  18. Slope sensitivities for optical surfaces

    NASA Astrophysics Data System (ADS)

    Rogers, John R.

    2015-09-01

    Setting a tolerance for the slope errors of an optical surface (e.g., surface form errors of the "mid-spatial-frequencies") requires some knowledge of how those surface errors affect the final image of the system. While excellent tools exist for simulating those effects on a surface-by-surface basis, considerable insight may be gained by examining, for each surface, a simple sensitivity parameter that relates the slope error on the surface to the ray displacement at the final image plane. Snell's law gives a relationship between the slope errors of a surface and the angular deviations of the rays emerging from the surface. For a singlet or thin doublet acting by itself, these angular deviations are related to ray deviations at the image plane by the focal length of the lens. However, for optical surfaces inside an optical system having a substantial axial extent, the focal length of the system is not the correct multiplier, as the sensitivity is influenced by the optical surfaces that follow. In this paper, a simple expression is derived that relates the slope errors at an arbitrary optical surface to the ray deviation at the image plane. This expression is experimentally verified by comparison to a real-ray perturbation analysis. The sensitivity parameter relates the RMS slope errors to the RMS spot radius, and also relates the peak slope error to the 100% spot radius, and may be used to create an RSS error budget for slope error. Application to various types of system are shown and discussed.

  19. Using Temperature Sensitive Paint Technology

    NASA Technical Reports Server (NTRS)

    Hamner, M. P.; Popernack, T. G., Jr.; Owens, L. R.; Wahls, R. A.

    2002-01-01

    New facilities and test techniques afford research aerodynamicists many opportunities to investigate complex aerodynamic phenomena. For example, NASA Langley Research Center's National Transonic Facility (NTF) can hold Mach number, Reynolds number, dynamic pressure, stagnation temperature and stagnation pressure constant during testing. This is important because the wing twist associated with model construction may mask important Reynolds number effects associated with the flight vehicle. Beyond this, the NTF's ability to vary Reynolds number allows for important research into the study of boundary layer transition. The capabilities of facilities such as the NTF coupled with test techniques such as temperature sensitive paint yield data that can be applied not only to vehicle design but also to validation of computational methods. Development of Luminescent Paint Technology for acquiring pressure and temperature measurements began in the mid-1980s. While pressure sensitive luminescent paints (PSP) were being developed to acquire data for aerodynamic performance and loads, temperature sensitive luminescent paints (TSP) have been used for a much broader range of applications. For example, TSP has been used to acquire surface temperature data to determine the heating due to rotating parts in various types of mechanical systems. It has been used to determine the heating pattern(s) on circuit boards. And, it has been used in boundary layer analysis and applied to the validation of full-scale flight performance predictions. That is, data acquired on the same model can be used to develop trends from off design to full scale flight Reynolds number, e.g. to show the progression of boundary layer transition. A discussion of issues related to successfully setting-up TSP tests and using TSP systems for boundary layer studies is included in this paper, as well as results from a variety of TSP tests. TSP images included in this paper are all grey-scale so that similar to

  20. Instrumentation for Sensitive Gas Measurements

    NASA Technical Reports Server (NTRS)

    OKeefe, Anthony

    2005-01-01

    An improved instrument for optical absorption spectroscopy utilizes off-axis paths in an optical cavity in order to increase detection sensitivity while suppressing resonance effects. The instrument is well suited for use in either cavity ring-down spectroscopy (CRDS) [in which one pulses an incident light beam and measures the rate of decay of light in the cavity] or integrated cavity output spectroscopy (ICOS) [in which one uses a continuous-wave incident light beam and measures the power of light in the cavity as a function of wavelength]. Typically, in optical absorption spectroscopy, one seeks to measure absorption of a beam of light in a substance (usually a gas or liquid) in a sample cell. In CRDS or ICOS, the sample cell is placed in (or consists of) an optical cavity, so that one can utilize multiple reflections of the beam to increase the effective optical path length through the absorbing substance and thereby increase the sensitivity for measuring absorption. If an absorbing substance is not present in the optical cavity, one can utilize the multiple passes of the light beam to increase the sensitivity for measuring absorption and scattering by components of the optical cavity itself. It is desirable to suppress the effects of resonances in the cavity in order to make the spectral response of the cavity itself as nearly constant as possible over the entire wavelength range of interest. In the present instrument, the desired flattening of the spectral response is accomplished by utilizing an off-axis beam geometry to effectively decrease the frequency interval between longitudinal electromagnetic modes of the cavity, such that the resulting transmission spectrum of the cavity is nearly continuous: in other words, the cavity becomes a broad-band optical device.

  1. Sensitivity of nonuniform sampling NMR.

    PubMed

    Palmer, Melissa R; Suiter, Christopher L; Henry, Geneive E; Rovnyak, James; Hoch, Jeffrey C; Polenova, Tatyana; Rovnyak, David

    2015-06-01

    Many information-rich multidimensional experiments in nuclear magnetic resonance spectroscopy can benefit from a signal-to-noise ratio (SNR) enhancement of up to about 2-fold if a decaying signal in an indirect dimension is sampled with nonconsecutive increments, termed nonuniform sampling (NUS). This work provides formal theoretical results and applications to resolve major questions about the scope of the NUS enhancement. First, we introduce the NUS Sensitivity Theorem in which any decreasing sampling density applied to any exponentially decaying signal always results in higher sensitivity (SNR per square root of measurement time) than uniform sampling (US). Several cases will illustrate this theorem and show that even conservative applications of NUS improve sensitivity by useful amounts. Next, we turn to a serious limitation of uniform sampling: the SNR by US decreases for extending evolution times, and thus total experimental times, beyond 1.26T2 (T2 = signal decay constant). Thus, SNR and resolution cannot be simultaneously improved by extending US beyond 1.26T2. We find that NUS can eliminate this constraint, and we introduce the matched NUS SNR Theorem: an exponential sampling density matched to the signal decay always improves the SNR with additional evolution time. Though proved for a specific case, broader classes of NUS densities also improve SNR with evolution time. Applications of these theoretical results are given for a soluble plant natural product and a solid tripeptide (u-(13)C,(15)N-MLF). These formal results clearly demonstrate the inadequacies of applying US to decaying signals in indirect nD-NMR dimensions, supporting a broader adoption of NUS. PMID:25901905

  2. Stab Sensitivity of Energetic Nanolaminates

    SciTech Connect

    Gash, A; Barbee, T; Cervantes, O

    2006-05-22

    This work details the stab ignition, small-scale safety, and energy release characteristics of bimetallic Al/Ni(V) and Al/Monel energetic nanolaminate freestanding thin films. The influence of the engineered nanostructural features of the energetic multilayers is correlated with both stab initiation and small-scale energetic materials testing results. Structural parameters of the energetic thin films found to be important include the bi-layer period, total thickness of the film, and presence or absence of aluminum coating layers. In general the most sensitive nanolaminates were those that were relatively thick, possessed fine bi-layer periods, and were not coated. Energetic nanolaminates were tested for their stab sensitivity as freestanding continuous parts and as coarse powders. The stab sensitivity of mock M55 detonators loaded with energetic nanolaminate was found to depend strongly upon both the particle size of the material and the configuration of nanolaminate material, in the detonator cup. In these instances stab ignition was observed with input energies as low as 5 mJ for a coarse powder with an average particle dimension of 400 {micro}m. Selected experiments indicate that the reacting nanolaminate can be used to ignite other energetic materials such as sol-gel nanostructured thermite, and conventional thermite that was either coated onto the multilayer substrate or pressed on it. These results demonstrate that energetic nanolaminates can be tuned to have precise and controlled ignition thresholds and can initiate other energetic materials and therefore are viable candidates as lead-free impact initiated igniters or detonators.

  3. Functional Oxygen Sensitivity of Astrocytes

    PubMed Central

    Angelova, Plamena R.; Kasymov, Vitaliy; Christie, Isabel; Sheikhbahaei, Shahriar; Turovsky, Egor; Marina, Nephtali; Korsak, Alla; Zwicker, Jennifer; Teschemacher, Anja G.; Ackland, Gareth L.; Funk, Gregory D.; Kasparov, Sergey; Abramov, Andrey Y.

    2015-01-01

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental animal (rats and mice) study shows that astrocytes, the most numerous brain glial cells, are sensitive to physiological changes in PO2. Astrocytes respond to decreases in PO2 a few millimeters of mercury below normal brain oxygenation with elevations in intracellular calcium ([Ca2+]i). The hypoxia sensor of astrocytes resides in the mitochondria in which oxygen is consumed. Physiological decrease in PO2 inhibits astroglial mitochondrial respiration, leading to mitochondrial depolarization, production of free radicals, lipid peroxidation, activation of phospholipase C, IP3 receptors, and release of Ca2+ from the intracellular stores. Hypoxia-induced [Ca2+]i increases in astrocytes trigger fusion of vesicular compartments containing ATP. Blockade of astrocytic signaling by overexpression of ATP-degrading enzymes or targeted astrocyte-specific expression of tetanus toxin light chain (to interfere with vesicular release mechanisms) within the brainstem respiratory rhythm-generating circuits reveals the fundamental physiological role of astroglial oxygen sensitivity; in low-oxygen conditions (environmental hypoxia), this mechanism increases breathing activity even in the absence of peripheral chemoreceptor oxygen sensing. These results demonstrate that astrocytes are functionally specialized CNS oxygen sensors tuned for rapid detection of physiological changes in brain oxygenation. SIGNIFICANCE STATEMENT Most, if not all, animal cells possess mechanisms that allow them to detect

  4. GHRS Sensitivity Monitor -- Cycle 3

    NASA Astrophysics Data System (ADS)

    Soderblom, David

    1992-06-01

    This proposal defines the long term sensitivity monitoring program for the Goddard High Resolution Spectrograph. It uses three UV standard stars, BD+28d4211, and BD+75d325. 1) BD+28d4211 will be the long term standard, and will allow cross-calibration with FOS. 2) BD+75d325 will provide backup during SMOV and will be observed as a close-out in Cycle 3. 3) AGK+81d266 will be observed to provide a baseline for the SMOV focus test. The exposure times are short and the medium resolution gratings will be used with the LSA.

  5. Sensitivity Assessment of Ozone Models

    SciTech Connect

    Shorter, Jeffrey A.; Rabitz, Herschel A.; Armstrong, Russell A.

    2000-01-24

    The activities under this contract effort were aimed at developing sensitivity analysis techniques and fully equivalent operational models (FEOMs) for applications in the DOE Atmospheric Chemistry Program (ACP). MRC developed a new model representation algorithm that uses a hierarchical, correlated function expansion containing a finite number of terms. A full expansion of this type is an exact representation of the original model and each of the expansion functions is explicitly calculated using the original model. After calculating the expansion functions, they are assembled into a fully equivalent operational model (FEOM) that can directly replace the original mode.

  6. Functional Oxygen Sensitivity of Astrocytes.

    PubMed

    Angelova, Plamena R; Kasymov, Vitaliy; Christie, Isabel; Sheikhbahaei, Shahriar; Turovsky, Egor; Marina, Nephtali; Korsak, Alla; Zwicker, Jennifer; Teschemacher, Anja G; Ackland, Gareth L; Funk, Gregory D; Kasparov, Sergey; Abramov, Andrey Y; Gourine, Alexander V

    2015-07-22

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2 ) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental animal (rats and mice) study shows that astrocytes, the most numerous brain glial cells, are sensitive to physiological changes in PO2 . Astrocytes respond to decreases in PO2 a few millimeters of mercury below normal brain oxygenation with elevations in intracellular calcium ([Ca(2+)]i). The hypoxia sensor of astrocytes resides in the mitochondria in which oxygen is consumed. Physiological decrease in PO2 inhibits astroglial mitochondrial respiration, leading to mitochondrial depolarization, production of free radicals, lipid peroxidation, activation of phospholipase C, IP3 receptors, and release of Ca(2+) from the intracellular stores. Hypoxia-induced [Ca(2+)]i increases in astrocytes trigger fusion of vesicular compartments containing ATP. Blockade of astrocytic signaling by overexpression of ATP-degrading enzymes or targeted astrocyte-specific expression of tetanus toxin light chain (to interfere with vesicular release mechanisms) within the brainstem respiratory rhythm-generating circuits reveals the fundamental physiological role of astroglial oxygen sensitivity; in low-oxygen conditions (environmental hypoxia), this mechanism increases breathing activity even in the absence of peripheral chemoreceptor oxygen sensing. These results demonstrate that astrocytes are functionally specialized CNS oxygen sensors tuned for rapid detection of physiological changes in brain oxygenation. Significance statement: Most, if not all, animal cells possess mechanisms that allow them to

  7. Fast, high sensitivity dewpoint hygrometer

    NASA Technical Reports Server (NTRS)

    Hoenk, Michael E. (Inventor)

    1998-01-01

    A dewpoint/frostpoint hygrometer that uses a surface moisture-sensitive sensor as part of an RF oscillator circuit with feedback control of the sensor temperature to maintain equilibrium at the sensor surface between ambient water vapor and condensed water/ice. The invention is preferably implemented using a surface acoustic wave (SAW) device in an RF oscillator circuit configured to generate a condensation-dependent output signal, a temperature sensor to measure the temperature of the SAW device and to distinguish between condensation-dependent and temperature-dependent signals, a temperature regulating device to control the temperature of the SAW device, and a feedback control system configured to keep the condensation-dependent signal nearly constant over time in the presence of time-varying humidity, corrected for temperature. The effect of this response is to heat or cool the surface moisture-sensitive device, which shifts the equilibrium with respect to evaporation and condensation at the surface of the device. The equilibrium temperature under feedback control is a measure of dewpoint or frostpoint.

  8. Arctic Sea ice model sensitivities.

    SciTech Connect

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  9. Naval Waste Package Design Sensitivity

    SciTech Connect

    T. Schmitt

    2006-12-13

    The purpose of this calculation is to determine the sensitivity of the structural response of the Naval waste packages to varying inner cavity dimensions when subjected to a comer drop and tip-over from elevated surface. This calculation will also determine the sensitivity of the structural response of the Naval waste packages to the upper bound of the naval canister masses. The scope of this document is limited to reporting the calculation results in terms of through-wall stress intensities in the outer corrosion barrier. This calculation is intended for use in support of the preliminary design activities for the license application design of the Naval waste package. It examines the effects of small changes between the naval canister and the inner vessel, and in these dimensions, the Naval Long waste package and Naval Short waste package are similar. Therefore, only the Naval Long waste package is used in this calculation and is based on the proposed potential designs presented by the drawings and sketches in References 2.1.10 to 2.1.17 and 2.1.20. All conclusions are valid for both the Naval Long and Naval Short waste packages.

  10. Phase-sensitive flow cytometer

    SciTech Connect

    Steinkamp, J.A.; Martin, J.C.; Crissman, H.A. )

    1993-01-01

    A phase-sensitive flow cytometer has been developed that combines flow cytometry and fluorescence spectroscopy measurement principles to provide unique capabilities for making phase-resolved measurements on single cells. Stained cells are analyzed as they intersect an intensity-modulated (sinusoid) laser beam. Fluorescence is measured using only a collecting lens, a longpass filter, and a photomultiplier tube detector. Signals are processed by phase-sensitive detection electronics to resolve signals from heterogeneous emissions and quantify decay lifetimes. Results have demonstrated: (1) signal phase shift and amplitude demodulation on fluorospheres and PI-stained cells; (2) a detection threshold of 800-300 fluorescein molecules equivalence for excitation frequencies 10 to 30 MHz; (3) measurement precision of 1.5% on fluorospheres and 4.0% on Pi-stained cells; (4) the resolution of Pi and FITC signals based on differences in their lifetimes; and (5) the measurement of single decay lifetimes by the two-phase ratio method. The significance of this new technology is that the number of fluorochromes usable in multilabeling experiments will be increased; background interferences (autofluorescence, unbound dye, nonspecific staining, Raman scatter) will be eliminated; and fluorescence lifetime can be quantified to study the interaction of fluorochrome binding.

  11. Glacier Sensitivity Across the Andes

    NASA Astrophysics Data System (ADS)

    Sagredo, E. A.; Lowell, T. V.; Rupper, S.

    2010-12-01

    Most of the research on causes driving former glacial fluctuations, and the climatic signals involved, has focused on the comparisons of sequences of glacial events in separate regions of the world and their temporal-phasing relationship with terrestrial or extraterrestrial climate-forcing mechanisms. Nevertheless the climatic signals related with these glacial advances are still under debate. This impossibility to resolve these questions satisfactorily have been generally attributed to the insufficiently precise chronologies and unevenly distributed records. However, behind these ideas lies the implicit assumption that glaciers situated in different climate regimes respond uniformly to similar climatic perturbations. This ongoing research is aimed to explore the climate-glacier relationship at regional scale, through the analysis of the spatial variability of glacier sensitivity to climatic change. By applying a Surface Energy Mass Balance model (SEMB) developed by Rupper and Roe (2008) to glaciers located in different climatic regimes, we analyzed the spatial variability of mass balance changes under different baseline conditions and under different scenarios of climatic change. For the sake of this research, the analysis is being focused on the Andes, which in its 9,000 km along the western margin of South America offers an unparalleled climatic diversity. Preliminary results suggest that above some threshold of climate change (a hypothetical uniform perturbation), all the glaciers across the Andes would respond in the “same direction” (advancing or retreating). Below that threshold, glaciers located in some climatic regimes may be insensitive to the specific perturbation. On the other hand, glaciers located in different climatic regimes may exhibit a “different magnitude” of change under a uniform climatic perturbation. Thus, glaciers located in the dry Andes of Perú, Chile and Argentina are more sensitive to precipitation changes than variations in

  12. Recent developments in structural sensitivity analysis

    NASA Technical Reports Server (NTRS)

    Haftka, Raphael T.; Adelman, Howard M.

    1988-01-01

    Recent developments are reviewed in two major areas of structural sensitivity analysis: sensitivity of static and transient response; and sensitivity of vibration and buckling eigenproblems. Recent developments from the standpoint of computational cost, accuracy, and ease of implementation are presented. In the area of static response, current interest is focused on sensitivity to shape variation and sensitivity of nonlinear response. Two general approaches are used for computing sensitivities: differentiation of the continuum equations followed by discretization, and the reverse approach of discretization followed by differentiation. It is shown that the choice of methods has important accuracy and implementation implications. In the area of eigenproblem sensitivity, there is a great deal of interest and significant progress in sensitivity of problems with repeated eigenvalues. In addition to reviewing recent contributions in this area, the paper raises the issue of differentiability and continuity associated with the occurrence of repeated eigenvalues.

  13. SEM probe of IC radiation sensitivity

    NASA Technical Reports Server (NTRS)

    Gauthier, M. K.; Stanley, A. G.

    1979-01-01

    Scanning Electron Microscope (SEM) used to irradiate single integrated circuit (IC) subcomponent to test for radiation sensitivity can localize area of IC less than .03 by .03 mm for determination of exact location of radiation sensitive section.

  14. Tackifier Dispersions to Make Pressure Sensitive Adhesives

    SciTech Connect

    2003-02-01

    Development of new processes for tackifier dispersion could improve the production of pressure sensitive adhesives. Pressure sensitive adhesives (PSAs) have the ability to adhere to different surfaces with manual or finger pressure.

  15. UV curable pressure sensitive adhesives

    SciTech Connect

    Glotfelter, C.A.

    1995-12-01

    Pressure sensitive adhesives (PSA`s) have become a ubiquitous element in our society, so much so, that the relative status of a society can be determined by the per capita consumption of PSA`s. We discuss new monomers as components of PSA formulations which enable adhesion to be achieved on a variety of substrates. Since solventless coating systems are desirable, the UV PSA market is of utmost importance to meeting the strict environmental guidelines now being imposed worldwide. In addition, highly ethoxylated monomers have shown promise in water dispersed PSA formulations, and a self-emulsifying acrylate monomer has been developed to offer dispersive abilities without using traditional emulsifying agents. This talk will focus on the effects of the materials described on properties of adhesive strength and shear strength in UV PSA formulations.

  16. Sensitive fiber-optic immunoassay

    NASA Astrophysics Data System (ADS)

    Walczak, Irene M.; Love, Walter F.; Slovacek, Rudolf E.

    1991-07-01

    The principles of evanescent wave theory were applied to an immunological sensor for detecting the cardiac-specific isoenzyme creatine kinase-MB (CK-MB). The detection of the CK-MB isoenzyme is used in conjunction with the total CK measurement in the diagnosis of acute myocardial infarction. The clinical range for CK-MB is from 2-100 ng/ml. Previous work which utilized the fluorophor, Fluorescein isothiocyanate (FITC), was able to discriminate between 0 and 3 ng/ml CK-MB. Use of the fluorophor B-phycoerythrin (BPE) increased the assay sensitivity to 0.1 ng/ml CK-MB. The data was collected for 15 minutes using an optical launch and collection angle of 25 degree(s). This fiber optic based system is homogeneous and requires no subsequent washing, handling, or processing steps after exposure to the sample.

  17. Point Source Location Sensitivity Analysis

    NASA Astrophysics Data System (ADS)

    Cox, J. Allen

    1986-11-01

    This paper presents the results of an analysis of point source location accuracy and sensitivity as a function of focal plane geometry, optical blur spot, and location algorithm. Five specific blur spots are treated: gaussian, diffraction-limited circular aperture with and without central obscuration (obscured and clear bessinc, respectively), diffraction-limited rectangular aperture, and a pill box distribution. For each blur spot, location accuracies are calculated for square, rectangular, and hexagonal detector shapes of equal area. The rectangular detectors are arranged on a hexagonal lattice. The two location algorithms consist of standard and generalized centroid techniques. Hexagonal detector arrays are shown to give the best performance under a wide range of conditions.

  18. Solvent sensitive polymer composite structures

    NASA Astrophysics Data System (ADS)

    Chiappini, A.; Armellini, C.; Carpentiero, A.; Minati, L.; Righini, G. C.; Ferrari, M.

    2013-11-01

    In this paper we describe a composite system based on polystyrene colloidal nanoparticles assembled and embedded in an elastomeric matrix (polymer colloidal crystal, PCC), in the specific we have designed a PCC structure which displays an iridescent green color that can be attributed to the photonic crystal effect. This effect has been exploited to create a chemical sensor, in fact optical measurements have evidenced that the composite structure presents a different optical response as a function of the solvent applied on the surface. In particular we have demonstrated that the PCC possess, for specific solvents: (i) high sensitivity, (ii) fast response (less than 1s), and (iii) reversibility of the signal change. Finally preliminary results on the PCC have shown that this system can be also used as optical writing substrate using a specific solvent as ink, moreover an erasing procedure is also reported and discussed.

  19. Sensitivity of Pulsar Timing Arrays

    NASA Astrophysics Data System (ADS)

    Siemens, Xavier

    2015-08-01

    For the better part of the last decade, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has been using the Green Bank and Arecibo radio telescopes to monitor millisecond pulsars. NANOGrav, along with similar international collaborations, the European Pulsar Timing Array and the Parkes Pulsar Timing Array in Australia, form a consortium of consortia: the International Pulsar Timing Array (IPTA). The goal of the IPTA is to directly detect low-frequency gravitational waves which cause small changes to the times of arrival of radio pulses from millisecond pulsars. In this talk I will discuss the work of NANOGrav and the IPTA as well as our sensitivity to gravitational waves from astrophysical sources. I will show that a detection is possible by the end of the decade.

  20. Sensitivity to Auditory Velocity Contrast.

    PubMed

    Locke, Shannon M; Leung, Johahn; Carlile, Simon

    2016-01-01

    A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold larger for velocity increases in the instantaneous velocity change condition, as compared to instantaneous velocity decreases or thresholds for the delayed velocity transition condition. This result cannot be explained by the current static "snapshot" model of auditory motion perception and suggest a continuous process where the percept of velocity is influenced by previous history of stimulation. PMID:27291488

  1. Measurement of visual contrast sensitivity

    NASA Astrophysics Data System (ADS)

    Vongierke, H. E.; Marko, A. R.

    1985-04-01

    This invention involves measurement of the visual contrast sensitivity (modulation transfer) function of a human subject by means of linear or circular spatial frequency pattern on a cathode ray tube whose contrast is automatically decreasing or increasing depending on the subject pressing or releasing a hand-switch button. The threshold of detection of the pattern modulation is found by the subject by adjusting the contrast to values which vary about the subject's threshold thereby determining the threshold and also providing by the magnitude of the contrast fluctuations between reversals some estimate of the variability of the subject's absolute threshold. The invention also involves the slow automatic sweeping of the spatial frequency of the pattern over the spatial frequencies after preset time intervals or after threshold has been defined at each frequency by a selected number of subject-determined threshold crossings; i.e., contrast reversals.

  2. Pressure sensitive conductive rubber blends

    SciTech Connect

    Hassan, H.H. ); Abdel-Bary, E.M. ); El-Mansy, M.K.; Khodair, H.A. )

    1989-12-01

    Butadiene-acrylonitrile rubber (NBR) was blended with polychloroprene (CR) according to standard techniques. The blend was mixed with different concentrations of ZnO. The vulcanized sample was subjected to electrical conductivity ({sigma}) measurements while different values of static pressure were applied on the sample. It was found that samples containing 7.5 phr ZnO showed a reasonable pressure sensitive increase of {sigma}. Furthermore, the {sigma} vs pressure relationship of rubber blend mixed with different concentrations of Fast Extrusion Furnace black (FEF) was investigated. It was found that rubber vulcanizate containing 40 phr FEF resulted in a negative value of the pressure coefficient of conductivity {approx equal} {minus} 4.5 KPa{sup {minus}1}.

  3. COS FUV Spectroscopic Sensitivity Monitoring

    NASA Astrophysics Data System (ADS)

    Bostroem, Azalee

    2012-10-01

    The goals of this program are:The main goal is to track the time dependence of sensitivity as a function of wavelength. Obtain exposures in all FUV gratings every month. Every month there will be 2 visits totaling 3 orbits {except May-July when GD71 is unavailable}. The 1 orbit visit will cover the G130M/1096/FUVB, G160M/1577/FUVA, and G160M/1623/FUVA central wavelengths. The 2 orbit visit will cover G130M/1222, G130M/1291, G130M/1327, G160M/1577/FUVB, G160M/1623/FUVB, G140L/1105/FUVA, and G140L/1230 central wavelengths. These comprise the reddest and bluest central wavelengths of each grating with additional coverage of the new G130M blue modes.

  4. Sensitivity to Auditory Velocity Contrast

    PubMed Central

    Locke, Shannon M.; Leung, Johahn; Carlile, Simon

    2016-01-01

    A natural auditory scene often contains sound moving at varying velocities. Using a velocity contrast paradigm, we compared sensitivity to velocity changes between continuous and discontinuous trajectories. Subjects compared the velocities of two stimulus intervals that moved along a single trajectory, with and without a 1 second inter stimulus interval (ISI). We found thresholds were threefold larger for velocity increases in the instantaneous velocity change condition, as compared to instantaneous velocity decreases or thresholds for the delayed velocity transition condition. This result cannot be explained by the current static “snapshot” model of auditory motion perception and suggest a continuous process where the percept of velocity is influenced by previous history of stimulation. PMID:27291488

  5. Rats are sensitive to ambiguity.

    PubMed

    Fast, Cynthia D; Blaisdell, Aaron P

    2011-12-01

    In the present study, we investigated response decisions made under conditions of incomplete information in rats. In Experiment 1, rats were trained on either a positive patterning (PP; A-, B-, AB+) or a negative patterning (NP; A+, B+, AB-) instrumental lever-press discrimination. Subjects that had learned an NP discrimination responded less to Cue A when Cue B was covered at test. The cover did not, however, affect test responses to Cue A in the PP condition. In Experiment 2, rats received concurrent training on both PP and NP discriminations. After concurrent training, responses to Cue A were different with B covered versus uncovered for both NP and PP discriminations. We discuss possible accounts for why exposure to a nonlinearly soluble discrimination (NP) may have affected sensitivity to cue ambiguity produced by the cover. These results have interesting implications for representational processes engaged in problem solving. PMID:21968926

  6. Cryogenic High-Sensitivity Magnetometer

    NASA Technical Reports Server (NTRS)

    Day, Peter; Chui, Talso; Goodstein, David

    2005-01-01

    A proposed magnetometer for use in a cryogenic environment would be sensitive enough to measure a magnetic-flux density as small as a picogauss (10(exp -16) Tesla). In contrast, a typical conventional flux-gate magnetometer cannot measure a magnetic-flux density smaller that about 1 microgauss (10(exp -10) Tesla). One version of this device, for operation near the low end of the cryogenic temperature range, would include a piece of a paramagnetic material on a platform, the temperature of which would be controlled with a periodic variation. The variation in temperature would be measured by use of a conventional germanium resistance thermometer. A superconducting coil would be wound around the paramagnetic material and coupled to a superconducting quantum interference device (SQUID) magnetometer.

  7. Using Dynamic Sensitivity Analysis to Assess Testability

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey; Morell, Larry; Miller, Keith

    1990-01-01

    This paper discusses sensitivity analysis and its relationship to random black box testing. Sensitivity analysis estimates the impact that a programming fault at a particular location would have on the program's input/output behavior. Locations that are relatively \\"insensitive" to faults can render random black box testing unlikely to uncover programming faults. Therefore, sensitivity analysis gives new insight when interpreting random black box testing results. Although sensitivity analysis is computationally intensive, it requires no oracle and no human intervention.

  8. Sensitivity to volcanic field boundary

    NASA Astrophysics Data System (ADS)

    Runge, Melody; Bebbington, Mark; Cronin, Shane; Lindsay, Jan; Rashad Moufti, Mohammed

    2016-04-01

    Volcanic hazard analyses are desirable where there is potential for future volcanic activity to affect a proximal population. This is frequently the case for volcanic fields (regions of distributed volcanism) where low eruption rates, fertile soil, and attractive landscapes draw populations to live close by. Forecasting future activity in volcanic fields almost invariably uses spatial or spatio-temporal point processes with model selection and development based on exploratory analyses of previous eruption data. For identifiability reasons, spatio-temporal processes, and practically also spatial processes, the definition of a spatial region is required to which volcanism is confined. However, due to the complex and predominantly unknown sub-surface processes driving volcanic eruptions, definition of a region based solely on geological information is currently impossible. Thus, the current approach is to fit a shape to the known previous eruption sites. The class of boundary shape is an unavoidable subjective decision taken by the forecaster that is often overlooked during subsequent analysis of results. This study shows the substantial effect that this choice may have on even the simplest exploratory methods for hazard forecasting, illustrated using four commonly used exploratory statistical methods and two very different regions: the Auckland Volcanic Field, New Zealand, and Harrat Rahat, Kingdom of Saudi Arabia. For Harrat Rahat, sensitivity of results to boundary definition is substantial. For the Auckland Volcanic Field, the range of options resulted in similar shapes, nevertheless, some of the statistical tests still showed substantial variation in results. This work highlights the fact that when carrying out any hazard analysis on volcanic fields, it is vital to specify how the volcanic field boundary has been defined, assess the sensitivity of boundary choice, and to carry these assumptions and related uncertainties through to estimates of future activity and

  9. Measure-theoretic sensitivity via finite partitions

    NASA Astrophysics Data System (ADS)

    Li, Jian

    2016-07-01

    For every positive integer n≥slant 2 , we introduce the concept of measure-theoretic n-sensitivity for measure-theoretic dynamical systems via finite measurable partitions, and show that an ergodic system is measure-theoretically n-sensitive but not (n  +  1)-sensitive if and only if its maximal pattern entropy is log n .

  10. A Measure of Spiritual Sensitivity for Children

    ERIC Educational Resources Information Center

    Stoyles, Gerard John; Stanford, Bonnie; Caputi, Peter; Keating, Alysha-Leigh; Hyde, Brendan

    2012-01-01

    Spirituality is an essential influence in a child's development. However, an age-appropriate measure of child's spiritual sensitivity is not currently available in the literature. This paper describes the development of a measure of children's spiritual sensitivity, the Spiritual Sensitivity Scale for Children (SSSC). Statistical analyses…

  11. Longitudinal Genetic Analysis of Anxiety Sensitivity

    ERIC Educational Resources Information Center

    Zavos, Helena M. S.; Gregory, Alice M.; Eley, Thalia C.

    2012-01-01

    Anxiety sensitivity is associated with both anxiety and depression and has been shown to be heritable. Little, however, is known about the role of genetic influence on continuity and change of symptoms over time. The authors' aim was to examine the stability of anxiety sensitivity during adolescence. By using a genetically sensitive design, the…

  12. A guide to unclassified sensitive information protection

    SciTech Connect

    Donahue, S.C.

    1996-11-14

    This document is a reference guide for CIC-Division employees who lead or participate in projects that use and/or produce unclassified sensitive information. It is intended for use on a case by case basis to develop project specific sensitive information handling procedures and standards. It contains criteria for identifying sensitive information and determining levels of sensitivity, and describes cost effective measures for protecting various levels of sensitive information. The goal of this document is to help establish good business practices that benefit both the Laboratory and its customers. Division personnel are encouraged to apply these guidelines.

  13. A high sensitivity THz detector

    NASA Astrophysics Data System (ADS)

    Su, Bo; Duan, Guoteng

    2011-08-01

    We have developed a novel THz detector which uses the cantilever technology and surface plasmon resonance (SPR) technology to achieve a high sensitivity. The Micro Electro Mechanical System (MEMS) technology is adopted to fabricate the detector, which comprise thermo-sensitive bi-material micro-cantilever, prism and optical readout system. The bi-material of Si3N4 and Al is used to fabricate the micro-cantilever because of the good absorption characteristic for THz of Si3N4 and the great difference in thermal expansion coefficient of the bi-material for the deformation of the micro-cantilever. In order to increase the deformation of micro-cantilever, the method of computer simulation is used to obtain the optimal structure of micro-cantilever and the thickness of Si3N4 and Al. The function of the glass prism is to make the incident light generate total reflection under certain conditions. The gold film is sputtering on the top of glass slide using the method of magnetron sputtering and it is necessary for the generation of SPR performance. The optical readout system can make the change of cantilever bending convert to the change of reflection luminous intensity proportionally. The heat on the micro-cantilever coming from the THz radiation can lose easily in the air, so the detector is placed vertically in a cylindrical vacuum chamber which is sealed with quartz glasses and polyethylene lamina at the two end surfaces respectively. The quartz glass is used for the incidence of visible polarized light and the polyethylene lamina for the THz radiation. In order to maintain the vacuum performance of the chamber, the mechanical pump and molecular pump are adopted. In static mode, THz radiation absorption raises the temperature of micro-cantilever, so it bends proportionally. The micro-cantilever bending changes the thicknesses of the gap between the micro-cantilever and the metallic thin film on the micro-prism. It will result in a shift of the SPR angle. Therefore, the

  14. Substrate-Sensitive Graphene Oxidation.

    PubMed

    Zhang, Zhuhua; Yin, Jun; Liu, Xiaofei; Li, Jidong; Zhang, Jiahuan; Guo, Wanlin

    2016-03-01

    The inertness of graphene toward reaction with ambient molecules is essential for realizing durable devices with stable performance. Many device applications require graphene to contact with substrates, but whose impact on the chemical property of graphene has been largely overlooked. Here, we combine comprehensive first-principles analyses with experiments to show that graphene oxidation is highly sensitive to substrates. Graphene remains inert on SiO2 and hexagonal boron nitride but becomes increasingly weak against oxidation on metal substrates because of enhanced charge transfer and chemical interaction between them. In particular, Ni and Co substrates lead to spontaneous oxidation of graphene, while a Cu substrate maximally promotes the oxygen diffusion on graphene, with an estimated diffusivity 13 orders of magnitude higher than that on freestanding graphene. Bilayer graphene is revealed to have high oxidation resistance independent of substrate and thus is a better choice for high-performance nanoelectronics. Our findings should be extendable to a wide spectrum of chemical functionalizations of two-dimensional materials mediated by substrates. PMID:26884318

  15. Contact sensitization in the elderly.

    PubMed

    Balato, Anna; Balato, Nicola; Di Costanzo, Luisa; Ayala, Fabio

    2011-01-01

    Contact dermatitis from irritant and allergic sources is the reason for 6% to 10% of all dermatologic visits with considerable morbidity and economic impact. Allergic contact dermatitis is a T-cell-mediated inflammatory reaction and develops in predisposed individuals as a consequence of environmental exposure to allergens. Aging is correlated with the rate and type of contact sensitization because of "immunosenescence." The number of old people is growing around the world. This contribution reviews the main findings from published epidemiologic studies on contact allergy in elderly populations. In all examined studies, patch testing was performed in patients with cutaneous manifestations possibly related to contact dermatitis; the prevalence of contact dermatitis in the elderly was from 33% to 64%. Establishing the most frequent allergens responsible for allergic contact dermatitis in the elderly is a hard task. The commonest allergens reported were nickel sulfate, fragrance mix, diamino diphenylmethane, lanolin alcohols, paraben mix, Euxyl K400, quinoline mix, and balsam of Peru. We emphasize that allergens surveillance is needed to realize an "elderly series" for having a useful adjunct to contact allergy that may help the treatment of each patient. PMID:21146728

  16. Threat sensitivity in bipolar disorder.

    PubMed

    Muhtadie, Luma; Johnson, Sheri L

    2015-02-01

    Life stress is a major predictor of the course of bipolar disorder. Few studies have used laboratory paradigms to examine stress reactivity in bipolar disorder, and none have assessed autonomic reactivity to laboratory stressors. In the present investigation we sought to address this gap in the literature. Participants, 27 diagnosed with bipolar I disorder and 24 controls with no history of mood disorder, were asked to complete a complex working memory task presented as "a test of general intelligence." Self-reported emotions were assessed at baseline and after participants were given task instructions; autonomic physiology was assessed at baseline and continuously during the stressor task. Compared to controls, individuals with bipolar disorder reported greater increases in pretask anxiety from baseline and showed greater cardiovascular threat reactivity during the task. Group differences in cardiovascular threat reactivity were significantly correlated with comorbid anxiety in the bipolar group. Our results suggest that a multimethod approach to assessing stress reactivity-including the use of physiological parameters that differentiate between maladaptive and adaptive profiles of stress responding-can yield valuable information regarding stress sensitivity and its associations with negative affectivity in bipolar disorder. (PsycINFO Database Record (c) 2015 APA, all rights reserved). PMID:25688436

  17. COS FUV Spectroscopic Sensitivity Monitoring

    NASA Astrophysics Data System (ADS)

    Bostroem, Azalee

    2013-10-01

    To track the time dependent sensitivity as a function of wavelength we will obtain exposures in all FUV gratings every month. There will be 2 types of monitoring sequences which will occur on alternating months. The complete monitoring sequence will use 3 orbits in 2 visits (except May - July when GD71 is unavailable). The 1 orbit visit will cover the G130M/1096/FUVB, G160M/1577/FUVA, and G160M/1623/FUVA modes. The 2 orbit visit will cover G130M/1222, G130M/1291, G130M/1327, G130M/1055/FUVA, G160M/1577/FUVB, G160M/1623/FUVB, G140L/1105, G140L/1230 modes. These comprise the reddest and bluest central wavelengths of each grating with additional coverage of the G130M blue modes. The reduced monitoring sequence in alternating months will use a 1 orbit visit to monitor the complete wavelength range of the standard modes using one central wavelength per grating. The modes covered are G130M/1291, G160M/1623, and G140L/1230. This reduced monitoring scheme, relative to C20, is put in place in C21 given that the slopes of the TDS seen to have stabilized at ~0%. Should any drastic changes occur, the contingency orbits will be activated.

  18. Sensitivity and Uncertainty Analysis Shell

    Energy Science and Technology Software Center (ESTSC)

    1999-04-20

    SUNS (Sensitivity and Uncertainty Analysis Shell) is a 32-bit application that runs under Windows 95/98 and Windows NT. It is designed to aid in statistical analyses for a broad range of applications. The class of problems for which SUNS is suitable is generally defined by two requirements: 1. A computer code is developed or acquired that models some processes for which input is uncertain and the user is interested in statistical analysis of the outputmore » of that code. 2. The statistical analysis of interest can be accomplished using the Monte Carlo analysis. The implementation then requires that the user identify which input to the process model is to be manipulated for statistical analysis. With this information, the changes required to loosely couple SUNS with the process model can be completed. SUNS is then used to generate the required statistical sample and the user-supplied process model analyses the sample. The SUNS post processor displays statistical results from any existing file that contains sampled input and output values.« less

  19. A Phenylpropanoid Glycoside as a Calcineurin Inhibitor Isolated from Magnolia obovata Thunb.

    PubMed

    Lee, Won Jeong; Moon, Jae Sun; Kim, Sung In; Bahn, Yong-Sun; Lee, Hanna; Kang, Tae Hoon; Shin, Heung Mook; Kim, Sung Uk

    2015-09-01

    To identify plant-derived cell signaling inhibitors with antifungal properties, a twocomponent screening system using both wild-type Cryptococcus neoformans and a calcineurin mutant was employed owing to their counter-regulatory actions on the Hog1 mitogenactivated protein kinase and calcineurin pathways. Of the 2,000 plant extracts evaluated, a single bioactive compound from M. obovata Thunb. was found to act specifically on the calcineurin pathway of C. neoformans. This compound was identified as magnoloside A, and had potent antifungal activities against various Cryptococcus strains with minimum inhibitory concentration values ranging from 1.0 to 4.0 μg/ml. PMID:26174771

  20. Food Approach and Food Avoidance in Young Children: Relation with Reward Sensitivity and Punishment Sensitivity

    PubMed Central

    Vandeweghe, Laura; Vervoort, Leentje; Verbeken, Sandra; Moens, Ellen; Braet, Caroline

    2016-01-01

    It has recently been suggested that individual differences in Reward Sensitivity and Punishment Sensitivity may determine how children respond to food. These temperamental traits reflect activity in two basic brain systems that respond to rewarding and punishing stimuli, respectively, with approach and avoidance. Via parent-report questionnaires, we investigate the associations of the general motivational temperamental traits Reward Sensitivity and Punishment Sensitivity with Food Approach and Food Avoidance in 98 preschool children. Consistent with the conceptualization of Reward Sensitivity in terms of approach behavior and Punishment Sensitivity in terms of avoidance behavior, Reward Sensitivity was positively related to Food Approach, while Punishment Sensitivity was positively related to Food Avoidance. Future research should integrate these perspectives (i.e., general temperamental traits Reward Sensitivity and Punishment Sensitivity, and Food Approach and Avoidance) to get a better understanding of eating behavior and related body weight. PMID:27445898

  1. Food Approach and Food Avoidance in Young Children: Relation with Reward Sensitivity and Punishment Sensitivity.

    PubMed

    Vandeweghe, Laura; Vervoort, Leentje; Verbeken, Sandra; Moens, Ellen; Braet, Caroline

    2016-01-01

    It has recently been suggested that individual differences in Reward Sensitivity and Punishment Sensitivity may determine how children respond to food. These temperamental traits reflect activity in two basic brain systems that respond to rewarding and punishing stimuli, respectively, with approach and avoidance. Via parent-report questionnaires, we investigate the associations of the general motivational temperamental traits Reward Sensitivity and Punishment Sensitivity with Food Approach and Food Avoidance in 98 preschool children. Consistent with the conceptualization of Reward Sensitivity in terms of approach behavior and Punishment Sensitivity in terms of avoidance behavior, Reward Sensitivity was positively related to Food Approach, while Punishment Sensitivity was positively related to Food Avoidance. Future research should integrate these perspectives (i.e., general temperamental traits Reward Sensitivity and Punishment Sensitivity, and Food Approach and Avoidance) to get a better understanding of eating behavior and related body weight. PMID:27445898

  2. Selective depression of motion sensitivity during saccades.

    PubMed Central

    Burr, D C; Holt, J; Johnstone, J R; Ross, J

    1982-01-01

    1. Horizontal gratings flashed for 20 ms were used to compare visual contrast sensitivity during horizontal saccades with sensitivity during normal vision, at three luminance levels, 4 X 10(2), 4 X 10(-2), and 4 X 10(-4) cd/m2. 2. Greatest sensitivity loss during saccades was found at low spatial frequencies. There is little or no loss at high spatial frequencies. 3. As luminance level is decreased there is a decrease in the spatial frequency below which saccadic sensitivity loss occurs. This shift in spatial frequency with luminance level, considered in conjunction with measurements of stationary and drifting gratings, indicates the functional involvement of movement sensitive mechanisms in saccadic sensitivity loss. 4. At the two lower luminance levels (4 X 10(-2) and 4 X 10(-4) cd/m2) sensitivity during saccades is greater than normal at high spatial frequencies. This enhancement of sensitivity was confirmed by forced choice measurements. 5. It was also shown that sensitivity to abrupt changes in the trajectory of moving gratings is lowered during saccades. 6. It is concluded that mechanisms sensitive to movement and transients are damped during saccades, so preventing perception of image motion during saccades and thereby preserving visual stability. PMID:7182461

  3. Insulin resistance and insulin sensitizers.

    PubMed

    Stumvoll, M; Häring, H

    2001-01-01

    Insulin resistance is a key factor in the pathogenesis of type 2 diabetes mellitus and a co-factor in the development of dyslipidaemia, hypertension and atherosclerosis. The causes of insulin resistance include factors such as obesity and physical inactivity, and there may also be genetic factors. The mechanism of obesity-related insulin resistance involves the release of factors from adipocytes which exert a negative effect on glucose metabolism: free fatty acids, tumour necrosis factor-alpha and the recently discovered hormone, resistin. The two resulting abnormalities observed consistently in glucose-intolerant states are impaired suppression of endogenous glucose production, and impaired stimulation of glucose uptake. Among the genetic factors, a polymorphism (Pro12Ala) in the peroxisome proliferator-activated receptor (PPAR) gamma is associated with a reduced risk of type 2 diabetes mellitus and increased insulin sensitivity, primarily that of lipolysis. On the other hand, the association with insulin resistance of a common polymorphism (Gly972Arg) in the insulin receptor substrate 1, long believed to be a plausible candidate gene, is weak at best. This polymorphism may instead be associated with reduced insulin secretion, which, in view of the recent recognition of the insulin signalling system in beta-cells, results in the development of a novel pathogenic concept. Finally, fine-mapping and positional cloning of the susceptibility locus on chromosome 2 resulted in the identification of a polymorphism (UCSNP-43 G/A) in the calpain-10 gene. In non-diabetic Pima Indians, this polymorphism was associated with insulin resistance of glucose disposal. The pharmacological treatment of insulin resistance has recently acquired a novel class of agents: the thiazolidinediones. They act through regulation of PPARgamma-dependent genes and probably interfere favourably with factors released from adipocytes which mediate obesity-associated insulin resistance. PMID:11684868

  4. Polarization Sensitive Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Park, B. Hyle; de Boer, Johannes F.

    Optical coherence tomography (OCT) is an interferometric technique capable of noninvasive high-resolution cross-sectional imaging by measuring the intensity of light reflected from within tissue [1]. This results in a noncontact imaging modality that provides images similar in scale and geometry to histology. Just as different stains can be used to enhance the contrast in histology, various extensions of OCT allow for visualization of features not readily apparent in traditional OCT. For example, optical Doppler tomography [2] can enable depth-resolved imaging of flow by observing differences in phase between successive depth scans [3-5]. This chapter will focus on polarization-sensitive OCT (PS-OCT), which utilizes depth-dependent changes in the polarization state of detected light to determine the light-polarization changing properties of a sample [6-11]. These properties, including birefringence, dichroism, and optic axis orientation, can be determined directly by studying the depth evolution of Stokes parameters [7-10, 12-16] or indirectly by using the changing reflected polarization states to first determine Jones or Mueller matrices [11, 17-21]. PS-OCT has been used in a wide variety of applications, including correlating burn depth with a decrease in birefringence [14], measuring the birefringence of the retinal nerve fiber layer [22, 23], and monitoring the onset and progression of caries lesions [24]. In this chapter, a discussion of polarization theory and its application to PS-OCTwill be followed by clinical uses of the technology and will conclude with mentionof more recent work and future directions of PS-OCT.

  5. Extended Forward Sensitivity Analysis for Uncertainty Quantification

    SciTech Connect

    Haihua Zhao; Vincent A. Mousseau

    2008-09-01

    This report presents the forward sensitivity analysis method as a means for quantification of uncertainty in system analysis. The traditional approach to uncertainty quantification is based on a “black box” approach. The simulation tool is treated as an unknown signal generator, a distribution of inputs according to assumed probability density functions is sent in and the distribution of the outputs is measured and correlated back to the original input distribution. This approach requires large number of simulation runs and therefore has high computational cost. Contrary to the “black box” method, a more efficient sensitivity approach can take advantage of intimate knowledge of the simulation code. In this approach equations for the propagation of uncertainty are constructed and the sensitivity is solved for as variables in the same simulation. This “glass box” method can generate similar sensitivity information as the above “black box” approach with couples of runs to cover a large uncertainty region. Because only small numbers of runs are required, those runs can be done with a high accuracy in space and time ensuring that the uncertainty of the physical model is being measured and not simply the numerical error caused by the coarse discretization. In the forward sensitivity method, the model is differentiated with respect to each parameter to yield an additional system of the same size as the original one, the result of which is the solution sensitivity. The sensitivity of any output variable can then be directly obtained from these sensitivities by applying the chain rule of differentiation. We extend the forward sensitivity method to include time and spatial steps as special parameters so that the numerical errors can be quantified against other physical parameters. This extension makes the forward sensitivity method a much more powerful tool to help uncertainty analysis. By knowing the relative sensitivity of time and space steps with other

  6. New sensitive seismic cable with imbedded geophones

    NASA Astrophysics Data System (ADS)

    Pakhomov, Alex; Pisano, Dan; Goldburt, Tim

    2005-10-01

    Seismic detection systems for homeland security applications are an important additional layer to perimeter and border protection and other security systems. General Sensing Systems has been developing low mass, low cost, highly sensitive geophones. These geophones are being incorporated within a seismic cable. This article reports on the concept of a seismic sensitive cable and seismic sensitive ribbon design. Unlike existing seismic cables with sensitivity distributed along their lengths, the GSS new cable and ribbon possesses high sensitivity distributed in several points along the cable/ribbon with spacing of about 8-12 to 100 meters between geophones. This cable/ribbon is highly suitable for design and installation in extended perimeter protection systems. It allows the use of a mechanical cable layer for high speed installation. We show that any installation mistakes in using the GSS seismic sensitive cable/ribbon have low impact on output seismic signal value and detection range of security systems.

  7. Sensitivity in risk analyses with uncertain numbers.

    SciTech Connect

    Tucker, W. Troy; Ferson, Scott

    2006-06-01

    Sensitivity analysis is a study of how changes in the inputs to a model influence the results of the model. Many techniques have recently been proposed for use when the model is probabilistic. This report considers the related problem of sensitivity analysis when the model includes uncertain numbers that can involve both aleatory and epistemic uncertainty and the method of calculation is Dempster-Shafer evidence theory or probability bounds analysis. Some traditional methods for sensitivity analysis generalize directly for use with uncertain numbers, but, in some respects, sensitivity analysis for these analyses differs from traditional deterministic or probabilistic sensitivity analyses. A case study of a dike reliability assessment illustrates several methods of sensitivity analysis, including traditional probabilistic assessment, local derivatives, and a ''pinching'' strategy that hypothetically reduces the epistemic uncertainty or aleatory uncertainty, or both, in an input variable to estimate the reduction of uncertainty in the outputs. The prospects for applying the methods to black box models are also considered.

  8. Sensitivity analysis of a wing aeroelastic response

    NASA Technical Reports Server (NTRS)

    Kapania, Rakesh K.; Eldred, Lloyd B.; Barthelemy, Jean-Francois M.

    1991-01-01

    A variation of Sobieski's Global Sensitivity Equations (GSE) approach is implemented to obtain the sensitivity of the static aeroelastic response of a three-dimensional wing model. The formulation is quite general and accepts any aerodynamics and structural analysis capability. An interface code is written to convert one analysis's output to the other's input, and visa versa. Local sensitivity derivatives are calculated by either analytic methods or finite difference techniques. A program to combine the local sensitivities, such as the sensitivity of the stiffness matrix or the aerodynamic kernel matrix, into global sensitivity derivatives is developed. The aerodynamic analysis package FAST, using a lifting surface theory, and a structural package, ELAPS, implementing Giles' equivalent plate model are used.

  9. Rational elicitation of cold-sensitive phenotypes.

    PubMed

    Baliga, Chetana; Majhi, Sandipan; Mondal, Kajari; Bhattacharjee, Antara; VijayRaghavan, K; Varadarajan, Raghavan

    2016-05-01

    Cold-sensitive phenotypes have helped us understand macromolecular assembly and biological phenomena, yet few attempts have been made to understand the basis of cold sensitivity or to elicit it by design. We report a method for rational design of cold-sensitive phenotypes. The method involves generation of partial loss-of-function mutants, at either buried or functional sites, coupled with selective overexpression strategies. The only essential input is amino acid sequence, although available structural information can be used as well. The method has been used to elicit cold-sensitive mutants of a variety of proteins, both monomeric and dimeric, and in multiple organisms, namely Escherichia coli, Saccharomyces cerevisiae, and Drosophila melanogaster This simple, yet effective technique of inducing cold sensitivity eliminates the need for complex mutations and provides a plausible molecular mechanism for eliciting cold-sensitive phenotypes. PMID:27091994

  10. Benchmark On Sensitivity Calculation (Phase III)

    SciTech Connect

    Ivanova, Tatiana; Laville, Cedric; Dyrda, James; Mennerdahl, Dennis; Golovko, Yury; Raskach, Kirill; Tsiboulia, Anatoly; Lee, Gil Soo; Woo, Sweng-Woong; Bidaud, Adrien; Patel, Amrit; Bledsoe, Keith C; Rearden, Bradley T; Gulliford, J.

    2012-01-01

    The sensitivities of the keff eigenvalue to neutron cross sections have become commonly used in similarity studies and as part of the validation algorithm for criticality safety assessments. To test calculations of the sensitivity coefficients, a benchmark study (Phase III) has been established by the OECD-NEA/WPNCS/EG UACSA (Expert Group on Uncertainty Analysis for Criticality Safety Assessment). This paper presents some sensitivity results generated by the benchmark participants using various computational tools based upon different computational methods: SCALE/TSUNAMI-3D and -1D, MONK, APOLLO2-MORET 5, DRAGON-SUSD3D and MMKKENO. The study demonstrates the performance of the tools. It also illustrates how model simplifications impact the sensitivity results and demonstrates the importance of 'implicit' (self-shielding) sensitivities. This work has been a useful step towards verification of the existing and developed sensitivity analysis methods.

  11. Theoretical shock sensitivity index for explosives.

    PubMed

    Mathieu, D

    2012-02-23

    On the basis of simple physical arguments, the ratio of the weakest bond dissociation energy of nitro compounds to their decomposition enthalpy per covalent bond is put forward as a practical shock sensitivity index. Without any empirical fitting, it correlates remarkably well (R ≥ 0.95) with shock sensitivity data reported for 16 molecules spanning the most significant families of explosive compounds. This result supports the underlying assumption that this property depends on the ability of decomposition events to propagate into the material. It demonstrates that sensitivity-structure relationships should take the energy content of the material into account. A linear regression against the present sensitivity index yields a predictive method with better performance than previous ones. Its sounder physical bases provide new insight into the molecular determinants of sensitivity and a compelling explanation for the sensitivity values reported for TATB and FOX-7. PMID:22276614

  12. Nanoparticles for Enhanced Sensitivity in Electrochemical Immunoassays

    SciTech Connect

    Lin, Yuehe; Wang, Jun; Wang, Hua; Wu, Hong; Tang, Zhiwen

    2008-10-12

    In this manuscript, we report on electrochemical biosensors based on various nanoparticles (NPs) as labels for sensitive detection of protein biomarkers. We used silica nanoparticle as a carrier to loading a large amount of electroactive species such as poly(guanine) for sensitive immunoassay of tumor necrosis factor-alpha (TNF-a). We took the advantages of the unique hollow structure and reconstruction properties of apoferritin to prepare Cd3(PO4)2 nanoparticles as labels for sensitive assay of TNF-a. A novel immunochromatographic/electro-chemical biosensor based on quantum dots as labels has also been developed for rapid and sensitive detection of prostate-specific antigen (PSA) in human serum. These biosensors are quite sensitive with the detection limit at pM level and these approaches based on nanoparticle labels offer a new avenue for sensitive detection of protein biomarkers.

  13. Spectroscopic Sensitivity Workout: First-order modes

    NASA Astrophysics Data System (ADS)

    Brown, Thomas

    2001-07-01

    This program is the basic sensitivity measurement for all supported MAMA and CCD first-order spectroscopic modes. It is run once in Cycle 10. Sensitivity measurements are done for all supported tilts of the gratings, at a S/N suitable to any particular setting, in order to get all measurements done in a reasonable number of orbits but still get a very accurate sensitivity measurement. Data for the newly available "pseudo-apertures" near CCD row 900 are also taken.

  14. Improvement of touch sensitivity by pressing.

    PubMed

    Jeong, Hie-yong; Higashimori, Mitsuru; Kaneko, Makoto

    2008-01-01

    It is really interesting to know how a blood flow has an influence on a touch sensitivity during human fingertip exploration over an environment. In this paper, we examine experimentally how the touch sensitivity is changed under the condition that the blood flow is interrupted compulsorily by pressing the proximal phalange of human finger. Through the weight discrimination test based on Weber's Law, we found that the touch sensitivity improves temporarily with the statistical significance test of below 0.1 %, when a finger proximal phalange is bound and pressed. Experimental results also show that there exists a meaningful correlationship between the stiffness of fingertip and the touch sensitivity. PMID:19163188

  15. Environmental sensitivities of quartz crystal oscillators

    NASA Technical Reports Server (NTRS)

    Walls, Fred L.

    1990-01-01

    The frequency, amplitude, and noise of the output signal of a quartz crystal controlled oscillator is affected by a large number of environmental effects. The physical basis for the sensitivity of precision oscillators to temperature, humidity, pressure, vibration, magnetic field, electric field, load, and radiation is discussed. The sensitivity of crystal oscillators to radiation is a very complex topic and poorly understood. Therefore only a few general results are mentioned. The sensitivity to most external influences often varies significantly from one oscillator type to another and from one unit of given type to another. For a given unit, the sensitivity to one parameter often depends on the value of other parameters and history.

  16. The ISS Sensitizing Agents Data Bank (BDS).

    PubMed

    Brunetto, Barbara; Binetti, Roberto; Ceccarelli, Federica; Costamagna, Francesca Marina; D'Angiolini, Antonella; Fabri, Alessandra; Ferri, Maurizio; Marcello, Ida; Riva, Giovanni; Roazzi, Paolo; Trucchi, Daniela; Tinghino, Raffaella

    2008-01-01

    The Istituto Superiore Sanità has developed a data bank on sensitizing substances (Banca Dati Sensibilizzanti, BDS), available on website (www.iss.it/bdse/), sharing complete, controlled and updated information coming from different sources, such as scientific publications, international agencies and governmental or non governmental organizations. It is worthwhile that the main objective of the BDS is not the classification of sensitizing or potentially sensitizing agents within specific risk classes, but it is essentially to provide concise and non confidential information related to this endpoint. At present, the BDS includes: all the substances officially classified by European Union, (Annex I to Directive 67/548/EEC), some substances listed in I (Directive 67/548/EEC) for endpoints different than "sensitization" but indicated as sensitizers by other relevant institutions, all the substances indicated as sensitizers by relevant agencies or institutions (ACGIH, DFG), some substances indicted as sensitizers by industry and other non-governmental organizations (ETAD and HERA), all the substances regarded as "potentially sensitizing dyes" by the Commission of the European Community for the award of the eco-label to textile products, some substances for which, even in the absence of any categorization by Union, ACGIH or DFG, it is not possible to exclude a sensitizing potential on the basis of reliable documents. PMID:18469378

  17. High-sensitivity nanosensors for biomarker detection†

    PubMed Central

    Swierczewska, Magdalena; Liu, Gang

    2013-01-01

    High sensitivity nanosensors utilize optical, mechanical, electrical, and magnetic relaxation properties to push detection limits of biomarkers below previously possible concentrations. The unique properties of nanomaterials and nanotechnology are exploited to design biomarker diagnostics. High-sensitivity recognition is achieved by signal and target amplification along with thorough pre-processing of samples. In this tutorial review, we introduce the type of detection signals read by nanosensors to detect extremely small concentrations of biomarkers and provide distinctive examples of high-sensitivity sensors. The use of such high-sensitivity nanosensors can offer earlier detection of disease than currently available to patients and create significant improvements in clinical outcomes. PMID:22187721

  18. The negative affect hypothesis of noise sensitivity.

    PubMed

    Shepherd, Daniel; Heinonen-Guzejev, Marja; Heikkilä, Kauko; Dirks, Kim N; Hautus, Michael J; Welch, David; McBride, David

    2015-05-01

    Some studies indicate that noise sensitivity is explained by negative affect, a dispositional tendency to negatively evaluate situations and the self. Individuals high in such traits may report a greater sensitivity to other sensory stimuli, such as smell, bright light and pain. However, research investigating the relationship between noise sensitivity and sensitivity to stimuli associated with other sensory modalities has not always supported the notion of a common underlying trait, such as negative affect, driving them. Additionally, other explanations of noise sensitivity based on cognitive processes have existed in the clinical literature for over 50 years. Here, we report on secondary analyses of pre-existing laboratory (n = 74) and epidemiological (n = 1005) data focusing on the relationship between noise sensitivity to and annoyance with a variety of olfactory-related stimuli. In the first study a correlational design examined the relationships between noise sensitivity, noise annoyance, and perceptual ratings of 16 odors. The second study sought differences between mean noise and air pollution annoyance scores across noise sensitivity categories. Results from both analyses failed to support the notion that, by itself, negative affectivity explains sensitivity to noise. PMID:25993104

  19. A review of sensitivity analysis techniques

    SciTech Connect

    Hamby, D.M.

    1993-12-31

    Mathematical models are utilized to approximate various highly complex engineering, physical, environmental, social, and economic phenomena. Model parameters exerting the most influence on model results are identified through a {open_quotes}sensitivity analysis.{close_quotes} A comprehensive review is presented of more than a dozen sensitivity analysis methods. The most fundamental of sensitivity techniques utilizes partial differentiation whereas the simplest approach requires varying parameter values one-at-a-time. Correlation analysis is used to determine relationships between independent and dependent variables. Regression analysis provides the most comprehensive sensitivity measure and is commonly utilized to build response surfaces that approximate complex models.

  20. The Negative Affect Hypothesis of Noise Sensitivity

    PubMed Central

    Shepherd, Daniel; Heinonen-Guzejev, Marja; Heikkilä, Kauko; Dirks, Kim N.; Hautus, Michael J.; Welch, David; McBride, David

    2015-01-01

    Some studies indicate that noise sensitivity is explained by negative affect, a dispositional tendency to negatively evaluate situations and the self. Individuals high in such traits may report a greater sensitivity to other sensory stimuli, such as smell, bright light and pain. However, research investigating the relationship between noise sensitivity and sensitivity to stimuli associated with other sensory modalities has not always supported the notion of a common underlying trait, such as negative affect, driving them. Additionally, other explanations of noise sensitivity based on cognitive processes have existed in the clinical literature for over 50 years. Here, we report on secondary analyses of pre-existing laboratory (n = 74) and epidemiological (n = 1005) data focusing on the relationship between noise sensitivity to and annoyance with a variety of olfactory-related stimuli. In the first study a correlational design examined the relationships between noise sensitivity, noise annoyance, and perceptual ratings of 16 odors. The second study sought differences between mean noise and air pollution annoyance scores across noise sensitivity categories. Results from both analyses failed to support the notion that, by itself, negative affectivity explains sensitivity to noise. PMID:25993104

  1. Sensitivity analysis of hydrodynamic stability operators

    NASA Technical Reports Server (NTRS)

    Schmid, Peter J.; Henningson, Dan S.; Khorrami, Mehdi R.; Malik, Mujeeb R.

    1992-01-01

    The eigenvalue sensitivity for hydrodynamic stability operators is investigated. Classical matrix perturbation techniques as well as the concept of epsilon-pseudoeigenvalues are applied to show that parts of the spectrum are highly sensitive to small perturbations. Applications are drawn from incompressible plane Couette, trailing line vortex flow and compressible Blasius boundary layer flow. Parametric studies indicate a monotonically increasing effect of the Reynolds number on the sensitivity. The phenomenon of eigenvalue sensitivity is due to the non-normality of the operators and their discrete matrix analogs and may be associated with large transient growth of the corresponding initial value problem.

  2. Stiff DAE integrator with sensitivity analysis capabilities

    Energy Science and Technology Software Center (ESTSC)

    2007-11-26

    IDAS is a general purpose (serial and parallel) solver for differential equation (ODE) systems with senstivity analysis capabilities. It provides both forward and adjoint sensitivity analysis options.

  3. Extended Forward Sensitivity Analysis for Uncertainty Quantification

    SciTech Connect

    Haihua Zhao; Vincent A. Mousseau

    2013-01-01

    This paper presents the extended forward sensitivity analysis as a method to help uncertainty qualification. By including time step and potentially spatial step as special sensitivity parameters, the forward sensitivity method is extended as one method to quantify numerical errors. Note that by integrating local truncation errors over the whole system through the forward sensitivity analysis process, the generated time step and spatial step sensitivity information reflect global numerical errors. The discretization errors can be systematically compared against uncertainties due to other physical parameters. This extension makes the forward sensitivity method a much more powerful tool to help uncertainty qualification. By knowing the relative sensitivity of time and space steps with other interested physical parameters, the simulation is allowed to run at optimized time and space steps without affecting the confidence of the physical parameter sensitivity results. The time and space steps forward sensitivity analysis method can also replace the traditional time step and grid convergence study with much less computational cost. Two well-defined benchmark problems with manufactured solutions are utilized to demonstrate the method.

  4. Extended Forward Sensitivity Analysis for Uncertainty Quantification

    SciTech Connect

    Haihua Zhao; Vincent A. Mousseau

    2011-09-01

    Verification and validation (V&V) are playing more important roles to quantify uncertainties and realize high fidelity simulations in engineering system analyses, such as transients happened in a complex nuclear reactor system. Traditional V&V in the reactor system analysis focused more on the validation part or did not differentiate verification and validation. The traditional approach to uncertainty quantification is based on a 'black box' approach. The simulation tool is treated as an unknown signal generator, a distribution of inputs according to assumed probability density functions is sent in and the distribution of the outputs is measured and correlated back to the original input distribution. The 'black box' method mixes numerical errors with all other uncertainties. It is also not efficient to perform sensitivity analysis. Contrary to the 'black box' method, a more efficient sensitivity approach can take advantage of intimate knowledge of the simulation code. In these types of approaches equations for the propagation of uncertainty are constructed and the sensitivities are directly solved for as variables in the simulation. This paper presents the forward sensitivity analysis as a method to help uncertainty qualification. By including time step and potentially spatial step as special sensitivity parameters, the forward sensitivity method is extended as one method to quantify numerical errors. Note that by integrating local truncation errors over the whole system through the forward sensitivity analysis process, the generated time step and spatial step sensitivity information reflect global numerical errors. The discretization errors can be systematically compared against uncertainties due to other physical parameters. This extension makes the forward sensitivity method a much more powerful tool to help uncertainty qualification. By knowing the relative sensitivity of time and space steps with other interested physical parameters, the simulation is allowed

  5. Anxiety Sensitivity and Obsessive-Compulsive Disorder

    ERIC Educational Resources Information Center

    Calamari, John E.; Rector, Neil A.; Woodard, John L.; Cohen, Robyn J.; Chik, Heather M.

    2008-01-01

    Anxiety sensitivity (AS), a cognitive risk factor for anxiety disorders, was evaluated in a homogeneous obsessive-compulsive disorder (OCD) sample. A total of 280 individuals with OCD completed measures. Evaluation of the Anxiety Sensitivity Index revealed a latent structure that was congruent with previous studies showing a single higher order…

  6. Skin Sensitizing Potency of Halogenated Platinum Salts.

    EPA Science Inventory

    The relationship between occupational exposure to halogenated platinum (Pt) salts and Pt-specific allergic sensitization is well-established. Although human case reports and clinical studies demonstrate that Pt salts are potent skin sensitizers, no studies have been published tha...

  7. Estimating Sobol Sensitivity Indices Using Correlations

    EPA Science Inventory

    Sensitivity analysis is a crucial tool in the development and evaluation of complex mathematical models. Sobol's method is a variance-based global sensitivity analysis technique that has been applied to computational models to assess the relative importance of input parameters on...

  8. Spectral sensitization of nanocrystalline solar cells

    DOEpatents

    Spitler, Mark T.; Ehret, Anne; Stuhl, Louis S.

    2002-01-01

    This invention relates to dye sensitized polycrystalline photoelectrochemical solar cells for use in energy transduction from light to electricity. It concerns the utility of highly absorbing organic chromophores as sensitizers in such cells and the degree to which they may be utilized alone and in combination to produce an efficient photoelectrochemical cell, e.g., a regenerative solar cell.

  9. Hispanics and Culturally Sensitive Mental Health Services.

    ERIC Educational Resources Information Center

    Hispanic Research Center Research Bulletin, 1985

    1985-01-01

    The objective of improving mental health care for Hispanics has been reviewed, most often, as dependent upon the provision of culturally sensitive mental health services. "Cultural sensitivity," however, is an imprecise term, especially when efforts are made to put it into operation when providing mental health services to Hispanic clients.…

  10. 78 FR 15710 - Strong Sensitizer Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ...The U.S. Consumer Product Safety Commission (CPSC or Commission) is announcing the availability of a document prepared by CPSC staff titled, ``Strong Sensitizer Guidance.'' This guidance document is intended to clarify the ``strong sensitizer'' definition, assist manufacturers in understanding how CPSC staff would assess whether a substance and/or product containing that substance should be......

  11. [Multiple sensitization to topically used corticosteroids].

    PubMed

    Junghans, C; Kuhlwein, A; Hausen, B M

    1986-01-01

    Sensitivity to single corticosteroids is well known. Polyvalent sensitization towards several different steroids has been described rarely. Contact allergy due to diflucortolone-21-valerate has not been described previously as far as we know. In our case the patient was allergic to three corticosteroids. PMID:2943572

  12. 40 CFR 798.4100 - Dermal sensitization.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Dermal sensitization. 798.4100 Section 798.4100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Specific Organ/Tissue Toxicity § 798.4100 Dermal sensitization. (a) Purpose. In the...

  13. Integrated Decision Strategies for Skin Sensitization Hazard

    EPA Science Inventory

    One of the top priorities of the Interagency Coordinating Committee for the Validation of Alternative Methods (ICCVAM) is the identification and evaluation of non-animal alternatives for skin sensitization testing. Although skin sensitization is a complex process, the key biologi...

  14. Sensitivity Analysis for some Water Pollution Problem

    NASA Astrophysics Data System (ADS)

    Le Dimet, François-Xavier; Tran Thu, Ha; Hussaini, Yousuff

    2014-05-01

    Sensitivity Analysis for Some Water Pollution Problems Francois-Xavier Le Dimet1 & Tran Thu Ha2 & M. Yousuff Hussaini3 1Université de Grenoble, France, 2Vietnamese Academy of Sciences, 3 Florida State University Sensitivity analysis employs some response function and the variable with respect to which its sensitivity is evaluated. If the state of the system is retrieved through a variational data assimilation process, then the observation appears only in the Optimality System (OS). In many cases, observations have errors and it is important to estimate their impact. Therefore, sensitivity analysis has to be carried out on the OS, and in that sense sensitivity analysis is a second order property. The OS can be considered as a generalized model because it contains all the available information. This presentation proposes a method to carry out sensitivity analysis in general. The method is demonstrated with an application to water pollution problem. The model involves shallow waters equations and an equation for the pollutant concentration. These equations are discretized using a finite volume method. The response function depends on the pollutant source, and its sensitivity with respect to the source term of the pollutant is studied. Specifically, we consider: • Identification of unknown parameters, and • Identification of sources of pollution and sensitivity with respect to the sources. We also use a Singular Evolutive Interpolated Kalman Filter to study this problem. The presentation includes a comparison of the results from these two methods. .

  15. Limits to Sensitivity in Laser Enhanced Ionization.

    ERIC Educational Resources Information Center

    Travis, J. C.

    1982-01-01

    Laser enhanced ionization (LEI) occurs when a tunable dye laser is used to excite a specific atomic population in a flame. Explores the origin of LEI's high sensitivity and identifies possible avenues to higher sensitivity by describing instrument used and experimental procedures and discussing ion formation/detection. (Author/JN)

  16. Design sensitivity analysis of nonlinear structural response

    NASA Technical Reports Server (NTRS)

    Cardoso, J. B.; Arora, J. S.

    1987-01-01

    A unified theory is described of design sensitivity analysis of linear and nonlinear structures for shape, nonshape and material selection problems. The concepts of reference volume and adjoint structure are used to develop the unified viewpoint. A general formula for design sensitivity analysis is derived. Simple analytical linear and nonlinear examples are used to interpret various terms of the formula and demonstrate its use.

  17. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.229 Shunting sensitivity. Each highway-rail...

  18. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  19. 40 CFR 766.18 - Method sensitivity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Method sensitivity. 766.18 Section 766.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS General Provisions § 766.18 Method sensitivity. The target level...

  20. 40 CFR 766.18 - Method sensitivity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Method sensitivity. 766.18 Section 766.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS General Provisions § 766.18 Method sensitivity. The target level...

  1. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  2. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  3. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  4. 40 CFR 766.18 - Method sensitivity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Method sensitivity. 766.18 Section 766.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS General Provisions § 766.18 Method sensitivity. The target level...

  5. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  6. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.229 Shunting sensitivity. Each highway-rail...

  7. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  8. 40 CFR 766.18 - Method sensitivity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Method sensitivity. 766.18 Section 766.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS General Provisions § 766.18 Method sensitivity. The target level...

  9. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  10. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  11. 40 CFR 766.18 - Method sensitivity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Method sensitivity. 766.18 Section 766.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS General Provisions § 766.18 Method sensitivity. The target level...

  12. Simulating performance sensitivity of supercomputer job parameters.

    SciTech Connect

    Clearwater, Scott Harvey; Kleban, Stephen David

    2003-03-01

    We report on the use of a supercomputer simulation to study the performance sensitivity to systematic changes in the job parameters of run time, number of CPUs, and interarrival time. We also examine the effect of changes in share allocation and service ratio for job prioritization under a Fair Share queuing Algorithm to see the effect on facility figures of merit. We used log data from the ASCI supercomputer Blue Mountain and the ASCI simulator BIRMinator to perform this study. The key finding is that the performance of the supercomputer is quite sensitive to all the job parameters with the interarrival rate of the jobs being most sensitive at the highest rates and increasing run times the least sensitive job parameter with respect to utilization and rapid turnaround. We also find that this facility is running near its maximum practical utilization. Finally, we show the importance of the use of simulation in understanding the performance sensitivity of a supercomputer.

  13. Coeliac disease and noncoeliac gluten sensitivity.

    PubMed

    Meijer, Caroline R; Shamir, Raanan; Mearin, Maria L

    2015-04-01

    The spectrum of gluten-related disorders was restricted to coeliac disease and wheat allergy, but the new contemporary entity referred to as noncoeliac gluten sensitivity has gained recognition mainly in adults but also in children. Noncoeliac gluten sensitivity is defined as the presence of a variety of symptoms related to gluten ingestion in patients in whom coeliac disease and wheat allergy have been excluded. The pathophysiology and biomarkers of coeliac disease and wheat allergy are well known, but this is not the case for noncoeliac gluten sensitivity. It is also not clear whether noncoeliac gluten sensitivity is caused by consumption of gluten or by consumption of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Randomized trials on noncoeliac gluten sensitivity in children are lacking and are hardly needed to evaluate its role in paediatric patients with gastroenterology to avoid the use of unnecessary restrictive diets in children and interference with proper diagnosis of coeliac disease. PMID:25564803

  14. A strategy to design novel structure photochromic sensitizers for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Wenjun; Wang, Jiaxing; Zheng, Zhiwei; Hu, Yue; Jin, Jiayu; Zhang, Qiong; Hua, Jianli

    2015-02-01

    Two sensitizers with novel structure were designed and synthetized by introducing photochromic bisthienylethene (BTE) group into the conjugated system. Thanks to the photochromic effect the sensitizers have under ultraviolet and visible light, the conjugated bridge can be restructured and the resulting two photoisomers showed different behaviors in photovoltaic devices. This opens up a new research way for the dye-sensitized solar cells (DSSCs).

  15. A low recombination rate indolizine sensitizer for dye-sensitized solar cells.

    PubMed

    Huckaba, Aron J; Yella, Aswani; Brogdon, Phillip; Scott Murphy, J; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Delcamp, Jared H

    2016-06-28

    A sensitizer incorporating a heavily alkylated surface blocking indolizine donor exhibits excellent light absorption and diminished recombination rates in dye-sensitized solar cells (DSCs). DSC device efficiencies (up to 8%) using either I(-)/I3(-) or Co(bpy)3(2+/3+) redox shuttles were obtained, which compare favourably to the known excellent surface coverage co-sensitization dye, . PMID:27301449

  16. [Species sensitivity evaluation of Pseudorasbora parva].

    PubMed

    Wang, Xiao-Nan; Liu, Zheng-Tao; Yan, Zhen-Guang; Zhang, Cong; He, Li; Meng, Shuang-Shuang

    2013-06-01

    Acute toxic effects of cadmium and copper to Pseudorasbora parva and copper to Daphnia magna were tested in this study. Then comparative analysis of species sensitivity of P. parva to six typical pollutants was performed with toxicity data from our experiments and published literatures. The result showed that: (1) P. parva was generally sensitive to various pollutants, especially to organic pollutants, and it was relatively most sensitive to pesticides. P. parva might be an indicator organism in organic pollution monitoring and a representative testing organism in the development of water quality criteria. (2) Cyprinidae was sensitive to various pollutants in fish sensitivity distribution, therefore the toxicity data of Cyprinidae should be given more attention in the study of water quality criteria and environmental monitoring. (3) P. parva was sensitive to various pollutants, and it had a stable position in fish sensitivity rank. This study indicated that P. parva might be an ideal indicator organism in environmental monitoring and a potential model organism in water quality criteria considering that it has a small size and is easy to obtain. PMID:23947052

  17. Sensitivity of resonant tunneling diode photodetectors.

    PubMed

    Pfenning, Andreas; Hartmann, Fabian; Langer, Fabian; Kamp, Martin; Höfling, Sven; Worschech, Lukas

    2016-09-01

    We have studied the sensitivity of AlGaAs/GaAs double barrier resonant tunneling diode photodetectors with an integrated GaInNAs absorption layer for light sensing at the telecommunication wavelength of λ = 1.3 μm for illumination powers from pico- to microwatts. The sensitivity decreases nonlinearly with power. An illumination power increase of seven orders of magnitude leads to a reduction of the photocurrent sensitivity from S I  = 5.82 × 10(3) A W(-1) to 3.2 A W(-1). We attribute the nonlinear sensitivity-power dependence to an altered local electrostatic potential due to hole-accumulation that on the one hand tunes the tunneling current, but on the other hand affects the lifetime of photogenerated holes. In particular, the lifetime decreases exponentially with increasing hole population. The lifetime reduction results from an enhanced electrical field, a rise of the quasi-Fermi level, and an increased energy splitting within the triangular potential well. The non-constant sensitivity is a direct result of the non-constant lifetime. Based on these findings, we provide an expression that allows us to calculate the sensitivity as a function of illumination power and bias voltage, show a way to model the time-resolved photocurrent, and determine the critical power up to which the resonant tunneling diode photodetector sensitivity can be assumed constant. PMID:27454462

  18. Pressure sensitivity of low permeability sandstones

    USGS Publications Warehouse

    Kilmer, N.H.; Morrow, N.R.; Pitman, J.K.

    1987-01-01

    Detailed core analysis has been carried out on 32 tight sandstones with permeabilities ranging over four orders of magnitude (0.0002 to 4.8 mD at 5000 psi confining pressure). Relationships between gas permeability and net confining pressure were measured for cycles of loading and unloading. For some samples, permeabilities were measured both along and across bedding planes. Large variations in stress sensitivity of permeability were observed from one sample to another. The ratio of permeability at a nominal confining pressure of 500 psi to that at 5000 psi was used to define a stress sensitivity ratio. For a given sample, confining pressure vs permeability followed a linear log-log relationship, the slope of which provided an index of pressure sensitivity. This index, as obtained for first unloading data, was used in testing relationships between stress sensitivity and other measured rock properties. Pressure sensitivity tended to increase with increase in carbonate content and depth, and with decrease in porosity, permeability and sodium feldspar. However, scatter in these relationships increased as permeability decreased. Tests for correlations between pressure sensitivity and various linear combinations of variables are reported. Details of pore structure related to diagenetic changes appears to be of much greater significance to pressure sensitivity than mineral composition. ?? 1987.

  19. Measurement methods of ultrasonic transducer sensitivity.

    PubMed

    Xiao, Dingguo; Fan, Qiong; Xu, Chunguang; Zhang, Xiuhua

    2016-05-01

    Sensitivity is an important parameter to describe the electro-acoustic energy conversion efficiency of ultrasonic transducer. In this paper, the definition of sensitivity and reciprocity of ultrasonic transducer is studied. The frequency response function of a transducer is the spectrum of its sensitivity, which reflects the response sensitivity of the transducer for input signals at different frequencies. Four common methods which are used to measure the disc-vibrator transducer sensitivity are discussed in current investigation. The reciprocity method and the pulse-echo method are based on the reciprocity of the transducer. In the laser vibrometer method measurement, the normal velocity on the transducer radiating surface is directly measured by a laser vibrometer. In the measurement process of the hydrophone method, a calibrated hydrophone is used to measure the transmitted field. The validity of these methods is checked by experimental test. All of the four methods described are sufficiently accurate for transducer sensitivity measurement, while each method has its advantages and limitations. In practical applications, the appropriate method to measure transducer sensitivity should be selected based on actual conditions. PMID:26953638

  20. Climate Sensitivity in the Geologic Past

    NASA Astrophysics Data System (ADS)

    Royer, Dana L.

    2016-06-01

    The response of temperature to CO2 change (climate sensitivity) in the geologic past may help inform future climate predictions. Proxies for CO2 and temperature generally imply high climate sensitivities: ≥3 K per CO2 doubling during ice-free times (fast-feedback sensitivity) and ≥6 K during times with land ice (Earth-system sensitivity). Climate models commonly underpredict the magnitude of climate change and have fast-feedback sensitivities close to 3 K. A better characterization of feedbacks in warm worlds raises climate sensitivity to values more in line with proxies and produces climate simulations that better fit geologic evidence. As CO2 builds in our atmosphere, we should expect both slow (e.g., land ice) and fast (e.g., vegetation, clouds) feedbacks to elevate the long-term temperature response over that predicted from the canonical fast-feedback value of 3 K. Because temperatures will not decline for centuries to millennia, climate sensitivities that integrate slower processes have relevance for current climate policy.

  1. Skin sensitization of epoxyaldehydes: importance of conjugation.

    PubMed

    Delaine, Tamara; Hagvall, Lina; Rudbäck, Johanna; Luthman, Kristina; Karlberg, Ann-Therese

    2013-05-20

    Structure-activity relationship (SAR) models are important tools for predicting the skin sensitization potential of new compounds without animal testing. In compounds possessing a structural alert (aldehyde) and an activation alert (double bond), it is important to consider bioactivation/autoxidation (e.g., epoxidation). In the present study, we have explored a series of aldehydes with regard to contact allergy. The chemical reactivity of these 6 aldehydes toward a model hexapeptide was investigated, and their skin sensitization potencies were evaluated using the local lymph node assay (LLNA). Overall, we observed a similar trend for the in vitro reactivity and the in vivo sensitization potency for the structural analogues in this study. The highly reactive conjugated aldehydes (α,β-unsaturated aldehydes and 2,3-epoxyaldehydes) are sensitizing moieties, while nonconjugated aldehydes and nonterminal aliphatic epoxides show low reactivity and low sensitization potency. Our data show the importance of not only double bond conjugation to aldehyde but also epoxide-aldehyde conjugation. The observations indicate that the formation of nonconjugated epoxides by bioactivation or autoxidation is not sufficient to significantly increase the sensitization potency of weakly sensitizing parent compounds. PMID:23534857

  2. [Spatial contrast sensitivity in multiple sclerosis].

    PubMed

    Vighetto, A; Grochowicki, M; Cousin, J

    1990-01-01

    Spatial contrast sensitivity was measured in 110 patients with multiple sclerosis (definite = 72, probable = 22, possible = 16) as part of a routine evaluation in a neuro-ophthalmological clinic. Results were compared with those of 37 normal controls matched for age. The test was abnormal in 71 p. 100 of patients. Contrast sensitivity was attenuated for 97 p. 100 of the eyes with optic neuritis and visual acuity drop, for 60 p. 100 of the eyes with recovered optic neuritis and for 36 p. 100 of the non affected eyes in the cases of unilateral optic neuritis. Among the 57 patients with normal visual acuity and no history of optic neuritis, 62 p. 100 had abnormal findings. Globally, contrast sensitivity was reduced on the whole spatial frequency range in cases of current optic neuritis, and mostly on the high or high and medium frequencies in the other cases. Our study confirms that spatial contrast sensitivity is the most sensitive of psychophysical methods to detect subclinical visual impairement in multiple sclerosis. Comparison with VEP's was performed in 66 patients. Both tests were roughly equally sensitive, but findings were concordant in only 63 p. 100 of the cases. The use of both VEP's and spatial contrast sensitivity increases the detection of latent optic neuritis. PMID:2359900

  3. Energy dependence corrections to MOSFET dosimetric sensitivity.

    PubMed

    Cheung, T; Butson, M J; Yu, P K N

    2009-03-01

    Metal Oxide Semiconductor Field Effect Transistors (MOSFET's) are dosimeters which are now frequently utilized in radiotherapy treatment applications. An improved MOSFET, clinical semiconductor dosimetry system (CSDS) which utilizes improved packaging for the MOSFET device has been studied for energy dependence of sensitivity to x-ray radiation measurement. Energy dependence from 50 kVp to 10 MV x-rays has been studied and found to vary by up to a factor of 3.2 with 75 kVp producing the highest sensitivity response. The detectors average life span in high sensitivity mode is energy related and ranges from approximately 100 Gy for 75 kVp x-rays to approximately 300 Gy at 6 MV x-ray energy. The MOSFET detector has also been studied for sensitivity variations with integrated dose history. It was found to become less sensitive to radiation with age and the magnitude of this effect is dependant on radiation energy with lower energies producing a larger sensitivity reduction with integrated dose. The reduction in sensitivity is however approximated reproducibly by a slightly non linear, second order polynomial function allowing corrections to be made to readings to account for this effect to provide more accurate dose assessments both in phantom and in-vivo. PMID:19400548

  4. Optimization for minimum sensitivity to uncertain parameters

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn I.; Adelman, Howard M.; Sobieszczanski-Sobieski, Jaroslaw

    1994-01-01

    A procedure to design a structure for minimum sensitivity to uncertainties in problem parameters is described. The approach is to minimize directly the sensitivity derivatives of the optimum design with respect to fixed design parameters using a nested optimization procedure. The procedure is demonstrated for the design of a bimetallic beam for minimum weight with insensitivity to uncertainties in structural properties. The beam is modeled with finite elements based on two dimensional beam analysis. A sequential quadratic programming procedure used as the optimizer supplies the Lagrange multipliers that are used to calculate the optimum sensitivity derivatives. The method was perceived to be successful from comparisons of the optimization results with parametric studies.

  5. Preload Sensitivity in Cardiac Assist Devices

    PubMed Central

    Fukamachi, Kiyotaka; Shiose, Akira; Massiello, Alex; Horvath, David J.; Golding, Leonard A. R.; Lee, Sangjin; Starling, Randall C.

    2013-01-01

    With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to understand the unique physiology of device-assisted circulation. Preload sensitivity as it relates to cardiac assist devices is derived from the Frank-Starling relationship between human ventricular filling pressures and ventricular stroke volume. In this review, we stratify the preload sensitivity of 17 implantable cardiac assist devices relative to the native heart and discuss the effect of preload sensitivity on left ventricular volume unloading, levels of cardiac support, and the future development of continuous-flow total artificial heart technology. PMID:23272869

  6. Adjoint sensitivity analysis of an ultrawideband antenna

    SciTech Connect

    Stephanson, M B; White, D A

    2011-07-28

    The frequency domain finite element method using H(curl)-conforming finite elements is a robust technique for full-wave analysis of antennas. As computers become more powerful, it is becoming feasible to not only predict antenna performance, but also to compute sensitivity of antenna performance with respect to multiple parameters. This sensitivity information can then be used for optimization of the design or specification of manufacturing tolerances. In this paper we review the Adjoint Method for sensitivity calculation, and apply it to the problem of optimizing a Ultrawideband antenna.

  7. Sensitivity of optimum solutions to problem parameters

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, J.; Barthelemy, J. F.; Ryan, K. M.

    1981-01-01

    Derivation of the sensitivity equations that yield the sensitivity derivatives directly, which avoids the costly and inaccurate perturb-and-reoptimize approach, is discussed and solvability of the equations is examined. The equations apply to optimum solutions obtained by direct search methods as well as those generated by procedures of the sequential unconstrained minimization technique class. Applications are discussed for the use of the sensitivity derivatives in extrapolation of the optimal objective function and design variable values for incremented parameters, optimization with multiple objectives, and decomposition of large optimization problems.

  8. Terminal context in context-sensitive grammars.

    NASA Technical Reports Server (NTRS)

    Book, R. V.

    1972-01-01

    Investigation of the conditions whereunder context-sensitive grammars generate context-free languages. The obtained results indicate that, if every noncontext-free rewriting rule of a context-sensitive grammar has as left context a string of terminal symbols and the left context is at least as long as the right context, then the language generated is context-free. Likewise, if every noncontext-free rewriting rule of a context-sensitive grammar has strings of terminal symbols as left and right contexts, then the language generated is also context-free.

  9. Sensitive detection of NMR for thin films.

    PubMed

    Lee, Soonchil

    2015-10-01

    NMR can provide valuable information about thin films, but its relatively low sensitivity allows data acquisition only from bulk samples. The sensitivity problem is circumvented by detection schemes with higher sensitivity and/or enhanced polarization. In most of these ingenious techniques, electrons play a central role through hyperfine interactions with the nuclei of interest or the conversion of the spin orientation to an electric charge. The state of the art in NMR is the control of a single nuclear spin state, the complete form of which is one of the ultimate goals of nanotechnology. PMID:26549846

  10. Performance of Caesalpinia sappan heartwood extract as photo sensitizer for dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Ananth, S.; Vivek, P.; Saravana Kumar, G.; Murugakoothan, P.

    2015-02-01

    A natural dye extracted from Caesalpinia sappan heartwood was used as photo sensitizer for the first time to fabricate titanium dioxide (TiO2) nanoparticles based dye sensitized solar cells. Brazilin and brazilein are the major pigments present in the natural dye and their optimized molecular structure were calculated using Density functional theory (DFT) at 6-31G (d) level. The HOMO-LUMO were performed to reveal the energy gap using optimized structure. Pure TiO2 nanoparticles in anatase phase were synthesized by sol-gel technique. The pure and natural dye sensitized TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies. Low cost and environment friendly dye sensitized solar cells were fabricated using natural dye sensitized TiO2 based photo anode. The solar light to electron conversion efficiency of Caesalpinia sappan heartwood extract sensitized dye sensitized solar cell is 1.1%.

  11. White paper: Chemical sensitivity: history and phenomenology.

    PubMed

    Miller, C S

    1994-01-01

    Nearly everyone has heard something about chemical sensitivity, either from personal experience with someone who has the condition or from the media. The television series Northern Exposure recently featured a chemically sensitive attorney who lived in a geodesic dome in Alaska, and L.A. Law depicted the struggles of a Persian Gulf veteran with chemical sensitivities who lost his case against the Veterans Administration, but may appeal later in the season. Television news programs and the printed media have showcased patients living spartan existences in remote areas or in aluminum foil-lined rooms. Our views of the illness no doubt are colored by our own personal experiences of it. While some discount or make jokes about chemical sensitivity or these patients, physicians who have seen a number of them are discovering that many appear to be credible individuals with prior good work records who say they became ill following an identifiable exposure to chemicals. PMID:7778099

  12. Physiognomic Sensitivity: Its Development and Modification.

    ERIC Educational Resources Information Center

    Schlesinger, Louis B.

    1979-01-01

    Reports a study of developmental differences among 4-, 6- and 8-year-old children in physiognomic sensitivity, the tendency of a perceiver to suffuse precepts with an emotional, affective, or expressive quality. (Author/GH)

  13. Hyperacusis: An Increased Sensitivity to Everyday Sounds

    MedlinePlus

    ... hyperacusis, withdrawal, social isolation, and depression are common. Hearing Loss Hearing tests usually indicate normal hearing sensitivity and ... problem in the way the brain processes sound. Hearing loss coupled with low tolerance to sound is another ...

  14. Pressure-Sensitive Paint: Effect of Substrate

    PubMed Central

    Quinn, Mark Kenneth; Yang, Leichao; Kontis, Konstantinos

    2011-01-01

    There are numerous ways in which pressure-sensitive paint can be applied to a surface. The choice of substrate and application method can greatly affect the results obtained. The current study examines the different methods of applying pressure-sensitive paint to a surface. One polymer-based and two porous substrates (anodized aluminum and thin-layer chromatography plates) are investigated and compared for luminescent output, pressure sensitivity, temperature sensitivity and photodegradation. Two luminophores [tris-Bathophenanthroline Ruthenium(II) Perchlorate and Platinum-tetrakis (pentafluorophenyl) Porphyrin] will also be compared in all three of the substrates. The results show the applicability of the different substrates and luminophores to different testing environments. PMID:22247685

  15. Polarization-sensitive interferometric synthetic aperture microscopy

    NASA Astrophysics Data System (ADS)

    South, Fredrick A.; Liu, Yuan-Zhi; Xu, Yang; Shemonski, Nathan D.; Carney, P. Scott; Boppart, Stephen A.

    2015-11-01

    Three-dimensional optical microscopy suffers from the well-known compromise between transverse resolution and depth-of-field. This is true for both structural imaging methods and their functional extensions. Interferometric synthetic aperture microscopy (ISAM) is a solution to the 3D coherent microscopy inverse problem that provides depth-independent transverse resolution. We demonstrate the extension of ISAM to polarization sensitive imaging, termed polarization-sensitive interferometric synthetic aperture microscopy (PS-ISAM). This technique is the first functionalization of the ISAM method and provides improved depth-of-field for polarization-sensitive imaging. The basic assumptions of polarization-sensitive imaging are explored, and refocusing of birefringent structures is experimentally demonstrated. PS-ISAM enables high-resolution volumetric imaging of birefringent materials and tissue.

  16. Switchable sensitizers stepwise lighting up lanthanide emissions

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Jiao, Peng-Chong; Xu, Hai-Bing; Tang, Ming-Jing; Yang, Xiao-Ping; Huang, Shaoming; Deng, Jian-Guo

    2015-03-01

    Analagous to a long-ranged rocket equipped with multi-stage engines, a luminescent compound with consistent emission signals across a large range of concentrations from two stages of sensitizers can be designed. In this approach, ACQ, aggregation-caused quenching effect of sensitizers, would stimulate lanthanide emission below 10-4 M, and then at concentrations higher than 10-3 M, the ``aggregation-induced emission'' (AIE) effect of luminophores would be activated with the next set of sensitizers for lanthanide emission. Simultaneously, the concentration of the molecules could be monitored digitally by the maximal excitation wavelengths, due to the good linear relationship between the maximal excitation wavelengths and the concentrations {lg(M)}. This model, wherein molecules are assembled with two stages (both AIE and ACQ effect) of sensitizers, may provide a practicable strategy for design and construction of smart lanthanide bioprobes, which are suitable in complicated bioassay systems in which concentration is variable.

  17. Quantification of adipose tissue insulin sensitivity.

    PubMed

    Søndergaard, Esben; Jensen, Michael D

    2016-06-01

    In metabolically healthy humans, adipose tissue is exquisitely sensitive to insulin. Similar to muscle and liver, adipose tissue lipolysis is insulin resistant in adults with central obesity and type 2 diabetes. Perhaps uniquely, however, insulin resistance in adipose tissue may directly contribute to development of insulin resistance in muscle and liver because of the increased delivery of free fatty acids to those tissues. It has been hypothesized that insulin adipose tissue resistance may precede other metabolic defects in obesity and type 2 diabetes. Therefore, precise and reproducible quantification of adipose tissue insulin sensitivity, in vivo, in humans, is an important measure. Unfortunately, no consensus exists on how to determine adipose tissue insulin sensitivity. We review the methods available to quantitate adipose tissue insulin sensitivity and will discuss their strengths and weaknesses. PMID:27073214

  18. High sensitivity cymbal-based accelerometer

    SciTech Connect

    Sun Chengliang; Lam, K.H.; Choy, S.H.; Chan, H.L. W.; Zhao, X.-Z.; Choy, C.L.

    2006-03-15

    A high sensitivity piezoelectric accelerometer has been developed by replacing the conventional piezoelectric rings with a cymbal transducer. The sensitivity of the cymbal-based accelerometers containing cymbal transducers with different endcap thicknesses and different seismic masses has been measured as a function of driving frequency. Due to the high d{sub 33}{sup '} coefficient of the cymbal transducers, the cymbal-based accelerometers have a high sensitivity of {approx}97 pC/ms{sup -2} with the amplitude rise of 2.85% (<1 dB) at one-third of the mounted resonance frequency (3.38 kHz). The effect of the seismic mass, the resonance frequency, and d{sub 33}{sup '} coefficient of the cymbal transducers on the sensitivity and the frequency range of the cymbal-based accelerometers are reported.

  19. [Metal implant sensitivity: clinical and histological presentation].

    PubMed

    Hartmann, D; Letulé, V; Schneider, J J; Flaig, M J

    2016-05-01

    Metal implant sensitivity (intolerance) can cause pain, reduced mobility, loosening of the implant and skin rashes. Knowledge of differential diagnoses, histology and appropriate diagnostics are essential for proper diagnosis. To outline typical clinical signs and histology in metal-implant-associated skin lesions we present three exemplary patients from our implant allergy outpatient department and give an overview of the current literature regarding metal implant sensitivity. In patients with a negative patch test the lymphocyte transformation test may reveal metal sensitization. Even "pure" titanium alloys may contain traces of nickel. The histology of implant-associated skin reactions goes from teleangiectatic postimplantation erythema to eczema and vasculitis. Based on the synopsis of history, clinical picture, allergological testing and histology, metal implant sensitivity can be diagnosed more precisely. PMID:27090521

  20. High Sensitivity Optically Pumped Quantum Magnetometer

    PubMed Central

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  1. Switchable sensitizers stepwise lighting up lanthanide emissions.

    PubMed

    Zhang, Yan; Jiao, Peng-Chong; Xu, Hai-Bing; Tang, Ming-Jing; Yang, Xiao-Ping; Huang, Shaoming; Deng, Jian-Guo

    2015-01-01

    Analagous to a long-ranged rocket equipped with multi-stage engines, a luminescent compound with consistent emission signals across a large range of concentrations from two stages of sensitizers can be designed. In this approach, ACQ, aggregation-caused quenching effect of sensitizers, would stimulate lanthanide emission below 10(-4) M, and then at concentrations higher than 10(-3) M, the "aggregation-induced emission" (AIE) effect of luminophores would be activated with the next set of sensitizers for lanthanide emission. Simultaneously, the concentration of the molecules could be monitored digitally by the maximal excitation wavelengths, due to the good linear relationship between the maximal excitation wavelengths and the concentrations {lg(M)}. This model, wherein molecules are assembled with two stages (both AIE and ACQ effect) of sensitizers, may provide a practicable strategy for design and construction of smart lanthanide bioprobes, which are suitable in complicated bioassay systems in which concentration is variable. PMID:25791467

  2. Photomaximization test for identifying photoallergic contact sensitizers.

    PubMed

    Kaidbey, K H; Kligman, A M

    1980-04-01

    The photomaximization procedure was designed to identify topical photocontact sensitizers following the format of the maximization test for contact sensitizers. The test agent is applied for 24 hours followed by exposure to three Minimal Erythema Doses (MED) of solar simulated radiation twice weekly for 3 weeks (six exposures) in a panel of 25 white Caucasoids. The subjects are challenged 2 weeks later with 4.0 J/cm2 of long-wave ultraviolet radiation (UV-A). Photocontact sensitization was induced to 3,3'4',5-tetrachlorosalicylanilide (TCSA); dibromosalicylanilide (DBS) but not to tribomosalicylanilide unless the latter was contaminated with DBS. Jadit and bithionol were weak photoallergens. The highest rate of sensitization was given by 6-methylcoumarin, a widely used synthetic fragrance. Hexachlorophene and trichlorocarbanilide were negative. PMID:7389322

  3. Chemotherapy sensitivity testing in human tumours.

    PubMed Central

    Richmond, H G; Billington, R W

    1981-01-01

    We have attempted to establish in vitro growth in a consecutive series of 245 malignant tumours submitted for routine histopathology. Initially, three disaggregation procedures were used: mechanical separation, digestion by trypsin, and digestion by collagenase. The resulting cell fractions had varying success rates in establishing growth. Abundant epithelial cell growth was achieved in monolayer culture in 63 tumours, and the sensitivity of the cells to cytotoxic agents was tested. There was no indiscriminate cytotoxic effect, and each tumour type varied in its sensitivity from one patient's lesion to another. While testing of all solid tumours is not possible with present-day techniques, we believe that the employment of in vitro sensitivity testing as a routine procedure may be possible in the future if a suitable system giving correlation between in vitro and in vivo sensitivity can be developed. Images PMID:7240421

  4. A Sixth Sense--Cultural Sensitivity.

    ERIC Educational Resources Information Center

    Jackson, Francesina R.

    1996-01-01

    This article presents suggestions for culturally sensitive modifications to help students from all backgrounds learn better. The modifications include building trust, building a repertoire of instructional strategies, using effective questioning techniques, providing effective feedback, analyzing instructional materials, and establishing positive…

  5. Mechanisms of Salt-Sensitive Hypertension.

    PubMed

    Luzardo, Leonella; Noboa, Oscar; Boggia, José

    2015-01-01

    Hypertension and its consequences, including heart failure, stroke, and kidney disease, are responsible for substantial morbidity and mortality worldwide. Lifestyle changes, particularly sodium reduction, contribute to blood pressure control. However, not all individuals, whether normotensive or hypertensive, have the same susceptibility to the effects of salt. While a variety of approaches have been proposed to identify salt sensitive patients, there is no consensus for a definition of salt sensitivity and the precise mechanisms that explain their association are not yet fully understood. In this review we summarize the current understanding of the various pathophysiological mechanisms potentially involved in determining the salt sensitive phenotype. Genetic, neuronal, and immune alterations are reviewed. Additionally, we provide an update on the current knowledge of a new approach proposing the interstitium of the skin may act as a sodium reservoir. The role of dietary potassium on salt sensitive hypertension is also summarized. PMID:26028243

  6. Multiple predictor smoothing methods for sensitivity analysis.

    SciTech Connect

    Helton, Jon Craig; Storlie, Curtis B.

    2006-08-01

    The use of multiple predictor smoothing methods in sampling-based sensitivity analyses of complex models is investigated. Specifically, sensitivity analysis procedures based on smoothing methods employing the stepwise application of the following nonparametric regression techniques are described: (1) locally weighted regression (LOESS), (2) additive models, (3) projection pursuit regression, and (4) recursive partitioning regression. The indicated procedures are illustrated with both simple test problems and results from a performance assessment for a radioactive waste disposal facility (i.e., the Waste Isolation Pilot Plant). As shown by the example illustrations, the use of smoothing procedures based on nonparametric regression techniques can yield more informative sensitivity analysis results than can be obtained with more traditional sensitivity analysis procedures based on linear regression, rank regression or quadratic regression when nonlinear relationships between model inputs and model predictions are present.

  7. Directional Sensitivity of the Human Ear.

    ERIC Educational Resources Information Center

    Pitt, John D.; Bazley, Martin

    1985-01-01

    Presents a classroom experiment that demonstrates the directional sensitivity of the human ear. Outlines the activity's procedures and provides a diagrammatical view of the experimental arrangement. Also included is an analysis of the expected results. (ML)

  8. Sensitivity analysis and application in exploration geophysics

    NASA Astrophysics Data System (ADS)

    Tang, R.

    2013-12-01

    In exploration geophysics, the usual way of dealing with geophysical data is to form an Earth model describing underground structure in the area of investigation. The resolved model, however, is based on the inversion of survey data which is unavoidable contaminated by various noises and is sampled in a limited number of observation sites. Furthermore, due to the inherent non-unique weakness of inverse geophysical problem, the result is ambiguous. And it is not clear that which part of model features is well-resolved by the data. Therefore the interpretation of the result is intractable. We applied a sensitivity analysis to address this problem in magnetotelluric(MT). The sensitivity, also named Jacobian matrix or the sensitivity matrix, is comprised of the partial derivatives of the data with respect to the model parameters. In practical inversion, the matrix can be calculated by direct modeling of the theoretical response for the given model perturbation, or by the application of perturbation approach and reciprocity theory. We now acquired visualized sensitivity plot by calculating the sensitivity matrix and the solution is therefore under investigation that the less-resolved part is indicated and should not be considered in interpretation, while the well-resolved parameters can relatively be convincing. The sensitivity analysis is hereby a necessary and helpful tool for increasing the reliability of inverse models. Another main problem of exploration geophysics is about the design strategies of joint geophysical survey, i.e. gravity, magnetic & electromagnetic method. Since geophysical methods are based on the linear or nonlinear relationship between observed data and subsurface parameters, an appropriate design scheme which provides maximum information content within a restricted budget is quite difficult. Here we firstly studied sensitivity of different geophysical methods by mapping the spatial distribution of different survey sensitivity with respect to the

  9. A high-temperature heat sensitive element

    NASA Technical Reports Server (NTRS)

    Oguro, M.

    1986-01-01

    This invention concerns the high-temperature heat sensitive element which is stable at high temperatures. A solid solution of the main component MgO-Al2O3-Cr2O3-Fe2O3 which contains spinel crystal structure is mixed with the secondary component ZrO2 at the mol ratio of 100 : 0.1 to 5.0 and sintered to prepare a high-temperature heat sensitive element.

  10. Sensitivity enhancement in the TROSY experiment.

    PubMed

    Czisch, M; Boelens, R

    1998-09-01

    A modification of the TROSY experiment which allows for sensitivity enhancement without introduction of additional delays is presented. The method relies on the combination of two orthogonal pathways and results in a signal-to-noise gain of 2 independent of the size of the molecule. The sensitivity enhanced TROSY scheme can be combined with gradient coherence selection. The method has been applied to the 269 residue serine protease PB92. PMID:9740742

  11. Sensitivity Enhancement in the TROSY Experiment

    NASA Astrophysics Data System (ADS)

    Czisch, M.; Boelens, R.

    1998-09-01

    A modification of the TROSY experiment which allows for sensitivity enhancement without introduction of additional delays is presented. The method relies on the combination of two orthogonal pathways and results in a signal-to-noise gain of2independent of the size of the molecule. The sensitivity enhanced TROSY scheme can be combined with gradient coherence selection. The method has been applied to the 269 residue serine protease PB92.

  12. Active Polymer Microfiber with Controlled Polarization Sensitivity

    PubMed Central

    Xia, Hongyan; Wang, Ruxue; Liu, Yingying; Cheng, Junjie; Zou, Gang; Zhang, Qijin; Zhang, Douguo; Wang, Pei; Ming, Hai; Badugu, Ramachandram; Lakowicz, Joseph R.

    2016-01-01

    Controlled Polarization Sensitivity of an active polymer microfiber has been proposed and realized with the electrospun method. The fluorescence intensity guiding through this active polymer microfiber shows high sensitivity to the polarization state of the excitation light. What is more, the fluorescence out-coupled from tip of the microfiber can be of designed polarization state. Principle of these phenomena lies on the ordered and controlled orientation of the polydiacetylene (PDA) main chains inside polymer microfiber. PMID:27099828

  13. Increased skeletal muscle capillarization enhances insulin sensitivity.

    PubMed

    Akerstrom, Thorbjorn; Laub, Lasse; Vedel, Kenneth; Brand, Christian Lehn; Pedersen, Bente Klarlund; Lindqvist, Anna Kaufmann; Wojtaszewski, Jørgen F P; Hellsten, Ylva

    2014-12-15

    Increased skeletal muscle capillarization is associated with improved glucose tolerance and insulin sensitivity. However, a possible causal relationship has not previously been identified. Therefore, we investigated whether increased skeletal muscle capillarization increases insulin sensitivity. Skeletal muscle-specific angiogenesis was induced by adding the α1-adrenergic receptor antagonist prazosin to the drinking water of Sprague-Dawley rats (n = 33), whereas 34 rats served as controls. Insulin sensitivity was measured ≥40 h after termination of the 3-wk prazosin treatment, which ensured that prazosin was cleared from the blood stream. Whole body insulin sensitivity was measured in conscious, unrestrained rats by hyperinsulinemic euglycemic clamp. Tissue-specific insulin sensitivity was assessed by administration of 2-deoxy-[(3)H]glucose during the plateau phase of the clamp. Whole body insulin sensitivity increased by ∼24%, and insulin-stimulated skeletal muscle 2-deoxy-[(3)H]glucose disposal increased by ∼30% concomitant with an ∼20% increase in skeletal muscle capillarization. Adipose tissue insulin sensitivity was not affected by the treatment. Insulin-stimulated muscle glucose uptake was enhanced independent of improvements in skeletal muscle insulin signaling to glucose uptake and glycogen synthesis, suggesting that the improvement in insulin-stimulated muscle glucose uptake could be due to improved diffusion conditions for glucose in the muscle. The prazosin treatment did not affect the rats on any other parameters measured. We conclude that an increase in skeletal muscle capillarization is associated with increased insulin sensitivity. These data point toward the importance of increasing skeletal muscle capillarization for prevention or treatment of type 2 diabetes. PMID:25352432

  14. Dye-sensitization of nanocrystalline semiconductor electrodes

    NASA Astrophysics Data System (ADS)

    Stipkala, Jeremy M.

    Electron transfer from excited sensitizer molecules into colloidal titanium dioxide thin film electrodes in the absence of an intimate covalent bond has been exploited to convert light into electricity. A brief review of research reported in the literature is given, which focuses on the kinetics of interfacial charge transfer events at sensitized sol-gel processed semiconductor particles. It was found that forward electron transfer from the sensitizer to the semiconductor is several orders of magnitude faster than the energy wasting recombination in the most successful systems. The novel results included here detail two new approaches to the problem of immobilizing sensitizers on the surface of the semiconductor. First, linkage ligands 4-methyl-4sp'-R-2,2sp'-bipyridine, where R = -COOH, -(CHsb2)sb3COOH, and -(CHsb2)sb3COCHsb2COOCsb2Hsb5 were synthesized. These ligands were incorporated into the sensitizer RuspII(dmb)sb2LL(PFsb6)sb2, where dmb = 4,4sp'-dimethyl-2,2sp'-bipyridine, and LL is the linkage ligand. The performance of these ruthenium sensitizers in regenerative solar cells was measured. It was found that the presence of the propylene spacer slows the recombination of the injected electron in the semiconductor with the oxidized sensitizer by a factor of 3-4. Second, electropolymerization of RuspII(vbpy) compounds, where vbpy is 4-methyl-4sp'-vinyl-2,2sp'-bipyridine, is explained. If the polymerization conditions are kept within narrow parameters, it is possible to add polymeric sensitizer to the semiconductor electrode and improve the cell performance. It was often observed, however, that the addition of polymer increased the dye surface coverage but lowered light-to-electricity conversion efficiencies. Evidence for self-quenching and iodide diffusion inhibition as mechanistic explanations for the reduced efficiencies from polymeric samples is given.

  15. The skin sensitization potential of four alkylalkanolamines.

    PubMed

    Leung, H W; Blaszcak, D L

    1998-04-01

    The skin sensitization potential of 4 alkylalkanolamines (N-methylethanolamine, N,N-dimethylethanolamine, N-methyldiethanolamine and N,N-diethylethanolamine), was evaluated in a guinea pig maximation procedure by the method of Magnusson and Kligman. While all 4 alkylalkanolamines tested were irritating to the guinea pig skin, only N-methylethanolamine showed potential to induce allergic contact dermatitis. None of the remaining 3 alkylalkanolamines exhibited clear skin responses suggestive of sensitization. PMID:9554055

  16. Multi-step contrast sensitivity gauge

    SciTech Connect

    Quintana, Enrico C; Thompson, Kyle R; Moore, David G; Heister, Jack D; Poland, Richard W; Ellegood, John P; Hodges, George K; Prindville, James E

    2014-10-14

    An X-ray contrast sensitivity gauge is described herein. The contrast sensitivity gauge comprises a plurality of steps of varying thicknesses. Each step in the gauge includes a plurality of recesses of differing depths, wherein the depths are a function of the thickness of their respective step. An X-ray image of the gauge is analyzed to determine a contrast-to-noise ratio of a detector employed to generate the image.

  17. Sensitivity of cellulolytic bacteria to antibiotics.

    PubMed

    Szegi, J; El-Din, H G

    1977-01-01

    The sensitivity of eight cellulolytic bacterial strains to eight antibiotics was tested. The results showed that, in general, the strains belonging to Cytophaga, Cellvibrio, and Cellfalcicula are more sensitive to antibiotics than those strains that belong to Sporocytophaga and Cellulomonas. The inhibitory activity of the tested antibiotics, though differing with different strains, showed the following categories: tetracycline, erythromycin, and chloromycetin were most active, kanamycin, streptomycin, and neomycin were intermediate, while novobiocin and penicillin showed low activity. PMID:414477

  18. Spatiotemporal contrast sensitivity of early vision.

    PubMed

    Van Hateren, J H

    1993-01-01

    Based on the spatial and temporal statistics of natural images, a theory is developed that specifies spatiotemporal filters that maximize the flow of information through noisy channels of limited dynamic range. Sensitivities resulting from these spatiotemporal filters are very similar to the human spatiotemporal contrast sensitivity, including the dependence on ambient light intensity. The theory predicts several psychophysical laws: Ferry-Porter's law, the de Vries-Rose law, Weber's law, Bloch's law, Ricco's law, and Piper's law. PMID:8447098

  19. Finite element model of needle electrode sensitivity

    NASA Astrophysics Data System (ADS)

    Høyum, P.; Kalvøy, H.; Martinsen, Ø. G.; Grimnes, S.

    2010-04-01

    We used the Finite Element (FE) Method to estimate the sensitivity of a needle electrode for bioimpedance measurement. This current conducting needle with insulated shaft was inserted in a saline solution and current was measured at the neutral electrode. FE model resistance and reactance were calculated and successfully compared with measurements on a laboratory model. The sensitivity field was described graphically based on these FE simulations.

  20. Gluten Sensitivity Presenting as a Neuropsychiatric Disorder

    PubMed Central

    Genuis, Stephen J.; Lobo, Rebecca A.

    2014-01-01

    There has been increasing recognition in the medical community and the general public of the widespread prevalence of gluten sensitivity. Celiac disease (CD) was initially believed to be the sole source of this phenomenon. Signs and symptoms indicative of nonceliac gluten sensitivity (NCGS), in which classical serum and intestinal findings of CD may be absent, have been frequently reported of late. Clinical manifestations in patients with NCGS are characteristically triggered by gluten and are ameliorated or resolved within days to weeks of commencing a gluten-free diet. Emerging scientific literature contains several reports linking gluten sensitivity states with neuropsychiatric manifestations including autism, schizophrenia, and ataxia. A clinical review of gluten sensitivity is presented alongside a case illustrating the life-changing difference achieved by gluten elimination in a patient with a longstanding history of auditory and visual hallucinations. Physicians in clinical practice should routinely consider sensitivity issues as an etiological determinant of otherwise inexplicable symptoms. Pathophysiologic mechanisms to explain the multisystem symptomatology with gluten sensitivity are considered. PMID:24693281

  1. Sensitivity of resonant tunneling diode photodetectors

    NASA Astrophysics Data System (ADS)

    Pfenning, Andreas; Hartmann, Fabian; Langer, Fabian; Kamp, Martin; Höfling, Sven; Worschech, Lukas

    2016-09-01

    We have studied the sensitivity of AlGaAs/GaAs double barrier resonant tunneling diode photodetectors with an integrated GaInNAs absorption layer for light sensing at the telecommunication wavelength of λ = 1.3 μm for illumination powers from pico- to microwatts. The sensitivity decreases nonlinearly with power. An illumination power increase of seven orders of magnitude leads to a reduction of the photocurrent sensitivity from S I = 5.82 × 103 A W‑1 to 3.2 A W‑1. We attribute the nonlinear sensitivity–power dependence to an altered local electrostatic potential due to hole-accumulation that on the one hand tunes the tunneling current, but on the other hand affects the lifetime of photogenerated holes. In particular, the lifetime decreases exponentially with increasing hole population. The lifetime reduction results from an enhanced electrical field, a rise of the quasi-Fermi level, and an increased energy splitting within the triangular potential well. The non-constant sensitivity is a direct result of the non-constant lifetime. Based on these findings, we provide an expression that allows us to calculate the sensitivity as a function of illumination power and bias voltage, show a way to model the time-resolved photocurrent, and determine the critical power up to which the resonant tunneling diode photodetector sensitivity can be assumed constant.

  2. Comparative Sensitivity Analysis of Muscle Activation Dynamics

    PubMed Central

    Rockenfeller, Robert; Günther, Michael; Schmitt, Syn; Götz, Thomas

    2015-01-01

    We mathematically compared two models of mammalian striated muscle activation dynamics proposed by Hatze and Zajac. Both models are representative for a broad variety of biomechanical models formulated as ordinary differential equations (ODEs). These models incorporate parameters that directly represent known physiological properties. Other parameters have been introduced to reproduce empirical observations. We used sensitivity analysis to investigate the influence of model parameters on the ODE solutions. In addition, we expanded an existing approach to treating initial conditions as parameters and to calculating second-order sensitivities. Furthermore, we used a global sensitivity analysis approach to include finite ranges of parameter values. Hence, a theoretician striving for model reduction could use the method for identifying particularly low sensitivities to detect superfluous parameters. An experimenter could use it for identifying particularly high sensitivities to improve parameter estimation. Hatze's nonlinear model incorporates some parameters to which activation dynamics is clearly more sensitive than to any parameter in Zajac's linear model. Other than Zajac's model, Hatze's model can, however, reproduce measured shifts in optimal muscle length with varied muscle activity. Accordingly we extracted a specific parameter set for Hatze's model that combines best with a particular muscle force-length relation. PMID:26417379

  3. Method for rapid isolation of sensitive mutants

    DOEpatents

    Freyer, James P.

    1997-01-01

    Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned.

  4. Method for rapid isolation of sensitive mutants

    DOEpatents

    Freyer, J.P.

    1997-07-29

    Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned. 15 figs.

  5. The directional sensitivity of retinal rods.

    PubMed Central

    Alpern, M; Ching, C C; Kitahara, K

    1983-01-01

    Rod field sensitivity, 10-S(r) (i.e. the reciprocal of the radiance of a background required for 10-fold elevation of rod threshold) was measured for monochromatic backgrounds traversing the pupil at various points (r) on three subjects. The wave-length dependency of the directional sensitivities of the three foveal cone mechanisms of the principal subject have been reported previously (Alpern & Kitahara, 1983). Rods, as cones, are less sensitive to obliquely incident, than to normally incident backgrounds. At the pupil margin (4 mm) the effect is between 0.368 and 0.976 log10 units smaller for rods. After correction for losses by corneal reflexion and by absorption in the lens, S(r) for rods is reasonably described by the parabolic equation used by Stiles (1937) to quantify the directional sensitivity of cones. The small effect for rods precludes a description as consistently precise as this equation provides for cones. The steepness of the parabolic curve best fitting the directional sensitivity data of the rods of the principal subject was independent of background wave number. For a second subject, whose rods are supposed to be smaller, it was directly proportional to the square of that wave number. The latter is the expectation if the directional sensitivity of this subject's rods were determined by principles outlined in the diffraction theory of Simon (1970). PMID:6644624

  6. Comparative Sensitivity Analysis of Muscle Activation Dynamics.

    PubMed

    Rockenfeller, Robert; Günther, Michael; Schmitt, Syn; Götz, Thomas

    2015-01-01

    We mathematically compared two models of mammalian striated muscle activation dynamics proposed by Hatze and Zajac. Both models are representative for a broad variety of biomechanical models formulated as ordinary differential equations (ODEs). These models incorporate parameters that directly represent known physiological properties. Other parameters have been introduced to reproduce empirical observations. We used sensitivity analysis to investigate the influence of model parameters on the ODE solutions. In addition, we expanded an existing approach to treating initial conditions as parameters and to calculating second-order sensitivities. Furthermore, we used a global sensitivity analysis approach to include finite ranges of parameter values. Hence, a theoretician striving for model reduction could use the method for identifying particularly low sensitivities to detect superfluous parameters. An experimenter could use it for identifying particularly high sensitivities to improve parameter estimation. Hatze's nonlinear model incorporates some parameters to which activation dynamics is clearly more sensitive than to any parameter in Zajac's linear model. Other than Zajac's model, Hatze's model can, however, reproduce measured shifts in optimal muscle length with varied muscle activity. Accordingly we extracted a specific parameter set for Hatze's model that combines best with a particular muscle force-length relation. PMID:26417379

  7. Light-sensitive brain pathways and aging.

    PubMed

    Daneault, V; Dumont, M; Massé, É; Vandewalle, G; Carrier, J

    2016-01-01

    Notwithstanding its effects on the classical visual system allowing image formation, light acts upon several non-image-forming (NIF) functions including body temperature, hormonal secretions, sleep-wake cycle, alertness, and cognitive performance. Studies have shown that NIF functions are maximally sensitive to blue wavelengths (460-480 nm), in comparison to longer light wavelengths. Higher blue light sensitivity has been reported for melatonin suppression, pupillary constriction, vigilance, and performance improvement but also for modulation of cognitive brain functions. Studies investigating acute stimulating effects of light on brain activity during the execution of cognitive tasks have suggested that brain activations progress from subcortical regions involved in alertness, such as the thalamus, the hypothalamus, and the brainstem, before reaching cortical regions associated with the ongoing task. In the course of aging, lower blue light sensitivity of some NIF functions has been reported. Here, we first describe neural pathways underlying effects of light on NIF functions and we discuss eye and cerebral mechanisms associated with aging which may affect NIF light sensitivity. Thereafter, we report results of investigations on pupillary constriction and cognitive brain sensitivity to light in the course of aging. Whereas the impact of light on cognitive brain responses appears to decrease substantially, pupillary constriction seems to remain more intact over the lifespan. Altogether, these results demonstrate that aging research should take into account the diversity of the pathways underlying the effects of light on specific NIF functions which may explain their differences in light sensitivity. PMID:26980095

  8. Inhomogeneous Forcing and Transient Climate Sensitivity

    NASA Technical Reports Server (NTRS)

    Shindell, Drew T.

    2014-01-01

    Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10-15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (less than 1.3 C) is very unlikely.

  9. A numerical comparison of sensitivity analysis techniques

    SciTech Connect

    Hamby, D.M.

    1993-12-31

    Engineering and scientific phenomena are often studied with the aid of mathematical models designed to simulate complex physical processes. In the nuclear industry, modeling the movement and consequence of radioactive pollutants is extremely important for environmental protection and facility control. One of the steps in model development is the determination of the parameters most influential on model results. A {open_quotes}sensitivity analysis{close_quotes} of these parameters is not only critical to model validation but also serves to guide future research. A previous manuscript (Hamby) detailed many of the available methods for conducting sensitivity analyses. The current paper is a comparative assessment of several methods for estimating relative parameter sensitivity. Method practicality is based on calculational ease and usefulness of the results. It is the intent of this report to demonstrate calculational rigor and to compare parameter sensitivity rankings resulting from various sensitivity analysis techniques. An atmospheric tritium dosimetry model (Hamby) is used here as an example, but the techniques described can be applied to many different modeling problems. Other investigators (Rose; Dalrymple and Broyd) present comparisons of sensitivity analyses methodologies, but none as comprehensive as the current work.

  10. Making sense of global sensitivity analyses

    NASA Astrophysics Data System (ADS)

    Wainwright, Haruko M.; Finsterle, Stefan; Jung, Yoojin; Zhou, Quanlin; Birkholzer, Jens T.

    2014-04-01

    This study presents improved understanding of sensitivity analysis methods through a comparison of the local sensitivity and two global sensitivity analysis methods: the Morris and Sobol‧/Saltelli methods. We re-interpret the variance-based sensitivity indices from the Sobol‧/Saltelli method as difference-based measures. It suggests that the difference-based local and Morris methods provide the effect of each parameter including its interaction with others, similar to the total sensitivity index from the Sobol‧/Saltelli method. We also develop an alternative approximation method to efficiently compute the Sobol‧ index, using one-dimensional fitting of system responses from a Monte-Carlo simulation. For illustration, we conduct a sensitivity analysis of pressure propagation induced by fluid injection and leakage in a reservoir-aquitard-aquifer system. The results show that the three methods provide consistent parameter importance rankings in this system. Our study also reveals that the three methods can provide additional information to improve system understanding.

  11. Noise sensitivity: Symptoms, health status, illness behavior and co-occurring environmental sensitivities.

    PubMed

    Baliatsas, Christos; van Kamp, Irene; Swart, Wim; Hooiveld, Mariëtte; Yzermans, Joris

    2016-10-01

    Epidemiological evidence on the symptomatic profile, health status and illness behavior of people with subjective sensitivity to noise is still scarce. Also, it is unknown to what extent noise sensitivity co-occurs with other environmental sensitivities such as multi-chemical sensitivity and sensitivity to electromagnetic fields (EMF). A cross-sectional study performed in the Netherlands, combining self-administered questionnaires and electronic medical records of non-specific symptoms (NSS) registered by general practitioners (GP) allowed us to explore this further. The study sample consisted of 5806 participants, drawn from 21 general practices. Among participants, 722 (12.5%) responded "absolutely agree" to the statement "I am sensitive to noise", comprising the high noise-sensitive (HNS) group. Compared to the rest of the sample, people in the HNS group reported significantly higher scores on number and duration of self-reported NSS, increased psychological distress, decreased sleep quality and general health, more negative symptom perceptions and higher prevalence of healthcare contacts, GP-registered NSS and prescriptions for antidepressants and benzodiazepines. These results remained robust after adjustment for demographic, residential and lifestyle characteristics, objectively measured nocturnal noise exposure from road-traffic and GP-registered morbidity. Co-occurrence rates with other environmental sensitivities varied between 9% and 50%. Individuals with self-declared sensitivity to noise are characterized by high prevalence of multiple NSS, poorer health status and increased illness behavior independently of noise exposure levels. Findings support the notion that different types of environmental sensitivities partly overlap. PMID:27232297

  12. Calcium Sensitization Mechanisms in Gastrointestinal Smooth Muscles

    PubMed Central

    Perrino, Brian A

    2016-01-01

    An increase in intracellular Ca2+ is the primary trigger of contraction of gastrointestinal (GI) smooth muscles. However, increasing the Ca2+ sensitivity of the myofilaments by elevating myosin light chain phosphorylation also plays an essential role. Inhibiting myosin light chain phosphatase activity with protein kinase C-potentiated phosphatase inhibitor protein-17 kDa (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) phosphorylation is considered to be the primary mechanism underlying myofilament Ca2+ sensitization. The relative importance of Ca2+ sensitization mechanisms to the diverse patterns of GI motility is likely related to the varied functional roles of GI smooth muscles. Increases in CPI-17 and MYPT1 phosphorylation in response to agonist stimulation regulate myosin light chain phosphatase activity in phasic, tonic, and sphincteric GI smooth muscles. Recent evidence suggests that MYPT1 phosphorylation may also contribute to force generation by reorganization of the actin cytoskeleton. The mechanisms responsible for maintaining constitutive CPI-17 and MYPT1 phosphorylation in GI smooth muscles are still largely unknown. The characteristics of the cell-types comprising the neuroeffector junction lead to fundamental differences between the effects of exogenous agonists and endogenous neurotransmitters on Ca2+ sensitization mechanisms. The contribution of various cell-types within the tunica muscularis to the motor responses of GI organs to neurotransmission must be considered when determining the mechanisms by which Ca2+ sensitization pathways are activated. The signaling pathways regulating Ca2+ sensitization may provide novel therapeutic strategies for controlling GI motility. This article will provide an overview of the current understanding of the biochemical basis for the regulation of Ca2+ sensitization, while also discussing the functional importance to different smooth muscles of the GI tract. PMID:26701920

  13. Protein kinase C sensitizes olfactory adenylate cyclase.

    PubMed

    Frings, S

    1993-02-01

    Effects of neurotransmitters on cAMP-mediated signal transduction in frog olfactory receptor cells (ORCs) were studied using in situ spike recordings and radioimmunoassays. Carbachol, applied to the mucosal side of olfactory epithelium, amplified the electrical response of ORCs to cAMP-generating odorants, but did not affect unstimulated cells. A similar augmentation of odorant response was observed in the presence of phorbol dibutyrate (PDBu), an activator of protein kinase C (PKC). The electrical response to forskolin, an activator of adenylate cyclase (AC), was also enhanced by PDBu, and it was attenuated by the PKC inhibitor Goe 6983. Forskolin-induced accumulation of cAMP in olfactory tissue was potentiated by carbachol, serotonin, and PDBu to a similar extent. Potentiation was completely suppressed by the PKC inhibitors Goe 6983, staurosporine, and polymyxin B, suggesting that the sensitivity of olfactory AC to stimulation by odorants and forskolin was increased by PKC. Experiments with deciliated olfactory tissue indicated that sensitization of AC was restricted to sensory cilia of ORCs. To study the effects of cell Ca2+ on these mechanisms, the intracellular Ca2+ concentration of olfactory tissue was either increased by ionomycin or decreased by BAPTA/AM. Increasing cell Ca2+ had two effects on cAMP production: (a) the basal cAMP production was enhanced by a mechanism sensitive to inhibitors of calmodulin; and (b) similar to phorbol ester, cell Ca2+ caused sensitization of AC to stimulation by forskolin, an effect sensitive to Goe 6983. Decreasing cell Ca2+ below basal levels rendered AC unresponsive to stimulation by forskolin. These data suggest that a crosstalk mechanism is functional in frog ORCs, linking the sensitivity of AC to the activity of PKC. At increased activity of PKC, olfactory AC becomes more responsive to stimulation by odorants, forskolin, and cell Ca2+. Neurotransmitters appear to use this crosstalk mechanism to regulate olfactory

  14. [Housing conditions and allergic sensitization in children].

    PubMed

    Heinrich, J; Hölscher, B; Wjst, M

    1998-09-01

    Genetic predisposition and indoor exposure to allergens-especially during the very early childhood years are major factors for the development of allergic diseases later in life. The present study analyzed the association between allergic sensitization in children aged 5 to 14 years and residing since birth in homes of different building types. A cross-sectional study of 811 children aged 5 to 14 years who resided in the same home since birth investigated indoor factors using a questionnaire and allergic sensitization assessed by skin prick test. The prevalence of allergic sensitization was compared between children who lived since birth in five different building types. After adjustment for age, gender, parental education and study area the odds of allergic sensitization were higher among children who lived in prefabricated concrete slab buildings built after 1970 (OR 1.56, 95% CI: 1.02-2.38) and among children who lived in new brick buildings (OR 1.75, 95% CI: 0.88-3.47) than among children who lived in old brick buildings. Moreover, the odds of pollen sensitization was higher among children who lived in the new building types (prefabricated slab buildings: OR 1.68, 95% CI: 1.04-2.72; new brick buildings: OR 1.48, 95% CI: 0.64-3.42) while living in timber-framed houses was associated with a higher odds of sensitization against mites (OR 1.63, 95% CI: 0.77-3.44). The step by step inclusion of single indoor factors like type of heating, numbers of building storeys, number of persons per room, environmental tobacco smoke, use of gas for cooking purposes, dampness of the home or visible moulds in the logistic regression model only marginally changed the odds ratios. Modern living conditions are associated with a higher odds of allergic sensitization. PMID:9789357

  15. Allergic contact sensitizing chemicals as environmental carcinogens.

    PubMed Central

    Albert, R E

    1997-01-01

    Chemicals that were bioassayed by the National Toxicology Program (NTP) and that also produce allergic dermatitis (ACD) in humans were evaluated for their tumorigenic characteristics. The impetus for the study was that most contact sensitizers, i.e., those that produce ACD, and genotoxic carcinogens are chemically similar in that they are electrophilic, thereby producing adducts on macromolecules including protein and DNA. This similarity in chemical behavior suggests that many contact sensitizers might be environmental carcinogens. All of the published NTP bioassays by early 1996 that had both genotoxicity and carcinogenicity studies were included in this analysis. The NTP chemicals had been chosen for bioassay without regard to their ability to produce ACD. Of the 209 chemicals that were bioassayed, there were 36 (17%) that were known to be human contact sensitizers; about half of these were positive on tumor bioassays. The contact sensitizers differed from the NTP sample as a whole by having a proportionately larger number of nongenotoxic chemicals by the Ames Salmonella assay, presumably because more of them were selected on the basis of widespread usage rather than structural resemblance to known carcinogens. Compared to the nongenotoxic chemicals, the genotoxics were stronger carcinogens in that they had a higher incidence of positive tumor bioassays, with twice the number of organs in which tumors were induced. The nongenotoxic chemicals had a preference for tumor induction in parenchymal tissues in contrast to epithelial tissues. The contact sensitizers showed essentially the same characteristics as the whole NTP sample when stratified according to genotoxicity. Judging by the chemicals that were chosen primarily for their widespread use rather than for their structural resemblance to carcinogens, the addition of a test for contact sensitization to the Ames test as a screening tool would increase the tumorigenic detection efficiency by about 40% because of

  16. Temperature sensitivity trends and multi-stimuli sensitive behavior in amphiphilic oligomers.

    PubMed

    Wang, Feng; Klaikherd, Akamol; Thayumanavan, S

    2011-08-31

    A series of oligomers, containing oligo(ethylene glycol) (OEG) moieties, with the same composition of amphiphilic functionalities has been designed, synthesized, and characterized on the basis of their temperature-sensitive behavior. The non-covalent amphiphilic aggregates, formed from these molecules, influence their temperature sensitivity. Covalent tethering of the amphiphilic units also has a significant influence on their temperature sensitivity. The lower critical solution temperatures of these oligomers show increasingly sharp transitions with increasing numbers of OEG functional groups, indicating enhanced cooperativity in dehydration of the OEG moieties when they are covalently tethered. These molecules were also engineered to be concurrently sensitive to enzymatic reaction and pH. This possibility was investigated using porcine liver esterase as the enzyme; we show that enzymatic action on the pentamer lowers its temperature sensitivity. The product moiety from the enzymatic reaction also gives the amphiphilic oligomer a pH-dependent temperature sensitivity. PMID:21739959

  17. Sensitivity to the weed killer DNA-nitralin and cross-sensitivity to dinitrochlorobenzene.

    PubMed

    Nishioka, K; Asagami, C; Kurata, M; Fujita, H

    1983-04-01

    A man, with a dermatitis acquired while working in a factory producing a weed killer, showed sensitivity to 4-methylsulfonyl 2,6-dinitro-N,N-dipropylaniline (DNA-nitralin) and its precursor, 4-chloro 3,-5-dinitrophenylmethyl sulfone (DNC), and cross-sensitivity to dinitrochlorobenzene (DNCB). Sensitization capacities of DNA-nitralin and DNC compared with DNCB, and cross-sensitizations among 11 dinitrobenzene derivatives, including DNA-nitralin, DNC, and DNCB, were studied in guinea pigs. We found that the order of potency was DNCB, DNC, and DNA-nitralin for the sensitization capacity, and that cross-sensitizations may occur among DNCB, DNC, DNA-nitralin, and dinitrofluorobenzene, in comparatively high incidence. PMID:6220678

  18. A strategy to design novel structure photochromic sensitizers for dye-sensitized solar cells

    PubMed Central

    Wu, Wenjun; Wang, Jiaxing; Zheng, Zhiwei; Hu, Yue; Jin, Jiayu; Zhang, Qiong; Hua, Jianli

    2015-01-01

    Two sensitizers with novel structure were designed and synthetized by introducing photochromic bisthienylethene (BTE) group into the conjugated system. Thanks to the photochromic effect the sensitizers have under ultraviolet and visible light, the conjugated bridge can be restructured and the resulting two photoisomers showed different behaviors in photovoltaic devices. This opens up a new research way for the dye-sensitized solar cells (DSSCs). PMID:25716204

  19. A strategy to design novel structure photochromic sensitizers for dye-sensitized solar cells.

    PubMed

    Wu, Wenjun; Wang, Jiaxing; Zheng, Zhiwei; Hu, Yue; Jin, Jiayu; Zhang, Qiong; Hua, Jianli

    2015-01-01

    Two sensitizers with novel structure were designed and synthetized by introducing photochromic bisthienylethene (BTE) group into the conjugated system. Thanks to the photochromic effect the sensitizers have under ultraviolet and visible light, the conjugated bridge can be restructured and the resulting two photoisomers showed different behaviors in photovoltaic devices. This opens up a new research way for the dye-sensitized solar cells (DSSCs). PMID:25716204

  20. Sensitivity Analysis in the Model Web

    NASA Astrophysics Data System (ADS)

    Jones, R.; Cornford, D.; Boukouvalas, A.

    2012-04-01

    The Model Web, and in particular the Uncertainty enabled Model Web being developed in the UncertWeb project aims to allow model developers and model users to deploy and discover models exposed as services on the Web. In particular model users will be able to compose model and data resources to construct and evaluate complex workflows. When discovering such workflows and models on the Web it is likely that the users might not have prior experience of the model behaviour in detail. It would be particularly beneficial if users could undertake a sensitivity analysis of the models and workflows they have discovered and constructed to allow them to assess the sensitivity to their assumptions and parameters. This work presents a Web-based sensitivity analysis tool which provides computationally efficient sensitivity analysis methods for models exposed on the Web. In particular the tool is tailored to the UncertWeb profiles for both information models (NetCDF and Observations and Measurements) and service specifications (WPS and SOAP/WSDL). The tool employs emulation technology where this is found to be possible, constructing statistical surrogate models for the models or workflows, to allow very fast variance based sensitivity analysis. Where models are too complex for emulation to be possible, or evaluate too fast for this to be necessary the original models are used with a carefully designed sampling strategy. A particular benefit of constructing emulators of the models or workflow components is that within the framework these can be communicated and evaluated at any physical location. The Web-based tool and backend API provide several functions to facilitate the process of creating an emulator and performing sensitivity analysis. A user can select a model exposed on the Web and specify the input ranges. Once this process is complete, they are able to perform screening to discover important inputs, train an emulator, and validate the accuracy of the trained emulator. In

  1. Super Sensitive Mass Detection in Nonlinear Regime

    NASA Astrophysics Data System (ADS)

    Azizi, Saber; Ahmadian, Iman; Cetinkaya, Cetin; Rezazadeh, Ghader

    2015-11-01

    Nonlinear dynamics of a clamped-clamped micro-beam exposed to a two sided electrostatic actuation is investigated to determine super sensitive regions for mass detection. The objective is to investigate the sensitivity of the frequency spectrum of various regions in the phase space to the added mass and force the system to operate in its super sensitive regions by applying an appropriate pulse to its control electrodes. The electrostatic actuation in the top electrode is a combination of a DC, AC and a pulse voltage, the excitation on the lower electrode is only a DC and a pulse voltage. The governing equation of the motion, derived using the Hamiltonian principle, is discretized to an equivalent single-degree of freedom system using the Galerkin method. Depending on the applied electrostatic voltage to the micro-beam, it is demonstrated that the number and types of equilibrium points of the system can be modified. In this study, the level of the DC electrostatic voltage is chosen such a way that the system has three equilibrium points including two centers and a saddle node where the homoclinic orbit originates. According to the reported results, the mass sensing sensitivity depends on the operating orbit; some orbits exhibit considerably higher mass detection sensitivity to the added mass compared to that of a typical quartz crystal micro balance instrument.

  2. Phosphatidylglycerol and Chilling Sensitivity in Plants

    PubMed Central

    Roughan, P. Grattan

    1985-01-01

    The hypothesis that molecular species of thylakoid phosphatidylglycerol containing two saturated fatty acids (disaturated phosphatidylglycerol) confer chilling sensitivity upon plants was tested by analyzing the fatty acid composition of phosphatidylglycerols isolated from leaves of a range of plants expected to have different sensitivities to chilling temperatures. `Saturated' fatty acids (palmitate plus stearate plus hexadeca-trans-3-enoate) as a proportion of total phosphatidylglycerol fatty acids varied from 51 to 80 mole per cent in the plants analyzed but appeared to be rigidly fixed for a given plant species, being unaffected by leaf maturity or by environment. Hexadeca-trans-3-enoate occurred only at the sn-2 position, whereas C-18 fatty acids occurred only at the sn-1 position of thylakoid phosphatidylglycerol. Therefore, the proportion of disaturated molecular species could be predicted accurately from the total fatty acids of phosphatidylglycerol. Disaturated molecular species accounted for <25% of the total phosphatidylglycerol from leaves of chilling-resistant plants and for 50 to 60% of the phosphatidylglycerol in leaves from some of the most chilling-sensitive plants. However, not all chilling-sensitive plants contained high proportions of disaturated phosphatidylglycerol; solanaceous and other 16:3-plants and C4 grasses may be important exceptions. Nonetheless, proportions of disaturated phosphatidylglycerol increased concomitantly with increasing chilling sensitivity of plants within a genus. PMID:16664127

  3. Depletion sensitivity predicts unhealthy snack purchases.

    PubMed

    Salmon, Stefanie J; Adriaanse, Marieke A; Fennis, Bob M; De Vet, Emely; De Ridder, Denise T D

    2016-01-01

    The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose weight on snack purchase behavior were explored. Participants included in the study were instructed to report every snack they bought over the course of one week. The dependent variables were the number of healthy and unhealthy snacks purchased. The results of the present study demonstrate that depletion sensitivity predicts the amount of unhealthy (but not healthy) snacks bought. The more sensitive people are to depletion, the more unhealthy snacks they buy. Moreover, there was some tentative evidence that this relation is more pronounced for people with a weak as opposed to a strong goal to lose weight, suggesting that a strong goal to lose weight may function as a motivational buffer against self-control failures. All in all, these findings provide evidence for the external validity of depletion sensitivity and the relevance of this construct in the domain of eating behavior. PMID:26321417

  4. Corneal and conjunctival sensitivity in rosacea patients

    PubMed Central

    Örnek, Nurgül; Karabulut, Ayşe Anıl; Örnek, Kemal; Onaran, Zafer; Usta, Gülşah

    2015-01-01

    Purpose To assess corneal and conjunctival sensitivity in rosacea patients. Methods A total of 55 patients with rosacea and 37 control subjects participated in the study. Corneal and conjunctival sensitivity was determined by Cochet-Bonnet esthesiometer. Subjective symptoms of ocular dryness were evaluated using Ocular Surface Disease Index (OSDI). Schirmer’s I test (ST), tear breakup time (tBUT) and ocular surface staining with fluorescein were carried out to measure objective signs. Results The mean corneal and conjunctival sensitivity did not differ significantly between rosacea patients and controls (all p > 0.05). Schirmer’s I test and tBUT were significantly reduced (p = 0.004 for OD and p < 0.001 for OS) and grade of ocular surface staining was significantly high (p = 0.018 for OD and p = 0.038 for OS) in rosacea patients. Corneal and conjunctival sensitivity did not show significant correlation with ST, tBUT, ocular surface staining (Oxford Schema), duration of rosacea and OSDI score. Conclusions Corneal and conjunctival sensitivity did not change significantly in rosacea. PMID:26949355

  5. Highly Energetic, Low Sensitivity Aromatic Peroxy Acids.

    PubMed

    Gamage, Nipuni-Dhanesha H; Stiasny, Benedikt; Stierstorfer, Jörg; Martin, Philip D; Klapötke, Thomas M; Winter, Charles H

    2016-02-18

    The synthesis, structure, and energetic materials properties of a series of aromatic peroxy acid compounds are described. Benzene-1,3,5-tris(carboperoxoic) acid is a highly sensitive primary energetic material, with impact and friction sensitivities similar to those of triacetone triperoxide. By contrast, benzene-1,4-bis(carboperoxoic) acid, 4-nitrobenzoperoxoic acid, and 3,5-dinitrobenzoperoxoic acid are much less sensitive, with impact and friction sensitivities close to those of the secondary energetic material 2,4,6-trinitrotoluene. Additionally, the calculated detonation velocities of 3,5-dinitrobenzoperoxoic acid and 2,4,6-trinitrobenzoperoxoic acid exceed that of 2,4,6-trinitrotoluene. The solid-state structure of 3,5-dinitrobenzoperoxoic acid contains intermolecular O-H⋅⋅⋅O hydrogen bonds and numerous N⋅⋅⋅O, C⋅⋅⋅O, and O⋅⋅⋅O close contacts. These attractive lattice interactions may account for the less sensitive nature of 3,5-dinitrobenzoperoxoic acid. PMID:26743434

  6. Risk-Sensitivity in Bayesian Sensorimotor Integration

    PubMed Central

    Grau-Moya, Jordi; Ortega, Pedro A.; Braun, Daniel A.

    2012-01-01

    Information processing in the nervous system during sensorimotor tasks with inherent uncertainty has been shown to be consistent with Bayesian integration. Bayes optimal decision-makers are, however, risk-neutral in the sense that they weigh all possibilities based on prior expectation and sensory evidence when they choose the action with highest expected value. In contrast, risk-sensitive decision-makers are sensitive to model uncertainty and bias their decision-making processes when they do inference over unobserved variables. In particular, they allow deviations from their probabilistic model in cases where this model makes imprecise predictions. Here we test for risk-sensitivity in a sensorimotor integration task where subjects exhibit Bayesian information integration when they infer the position of a target from noisy sensory feedback. When introducing a cost associated with subjects' response, we found that subjects exhibited a characteristic bias towards low cost responses when their uncertainty was high. This result is in accordance with risk-sensitive decision-making processes that allow for deviations from Bayes optimal decision-making in the face of uncertainty. Our results suggest that both Bayesian integration and risk-sensitivity are important factors to understand sensorimotor integration in a quantitative fashion. PMID:23028294

  7. Sensitivity of PBX-9502 after ratchet growth

    NASA Astrophysics Data System (ADS)

    Mulford, Roberta N.; Swift, Damian

    2012-03-01

    Ratchet growth, or irreversible thermal expansion of the TATB-based plastic-bonded explosive PBX-9502, leads to increased sensitivity, as a result of increased porosity. The observed increase of between 3.1 and 3.5 volume percent should increase sensitivity according to the published Pop-plots for PBX-9502 [1]. Because of the variable size, shape, and location of the increased porosity, the observed sensitivity of the ratchet-grown sample is less than the sensitivity of a sample pressed to the same density. Modeling of the composite, using a quasi-harmonic EOS for unreacted components [2] and a robust porosity model for variations in density [3], allowed comparison of the initiation observed in experiment with behavior modeled as a function of density. An Arrhenius model was used to describe reaction, and the EOS for products was generated using the CHEETAH code [4]. A 1-D Lagrangian hydrocode was used to model in-material gauge records and the measured turnover to detonation, predicting greater sensitivity to density than observed for ratchet-grown material. This observation is consistent with gauge records indicating intermittent growth of the reactive wave, possibly due to inhomogeneities in density, as observed in SEM images of the material [5].

  8. The quantitative genetics of disgust sensitivity.

    PubMed

    Sherlock, James M; Zietsch, Brendan P; Tybur, Joshua M; Jern, Patrick

    2016-02-01

    [Correction Notice: An Erratum for this article was reported in Vol 16(1) of Emotion (see record 2015-57029-001). In the article, the name of author Joshua M. Tybur was misspelled as Joshua M. Tyber. All versions of this article have been corrected.] Response sensitivity to common disgust elicitors varies considerably among individuals. The sources of these individual differences are largely unknown. In the current study, we use a large sample of female identical and nonidentical twins (N = 1,041 individuals) and their siblings (N = 170) to estimate the proportion of variation due to genetic effects, the shared environment, and other (residual) sources across multiple domains of disgust sensitivity. We also investigate the genetic and environmental influences on the covariation between the different disgust domains. Twin modeling revealed that approximately half of the variation in pathogen, sexual, and moral disgust is due to genetic effects. An independent pathways twin model also revealed that sexual and pathogen disgust sensitivity were influenced by unique sources of genetic variation, while also being significantly affected by a general genetic factor underlying all 3 disgust domains. Moral disgust sensitivity, in contrast, did not exhibit domain-specific genetic variation. These findings are discussed in light of contemporary evolutionary approaches to disgust sensitivity. PMID:26436990

  9. Spectral envelope sensitivity of musical instrument sounds.

    PubMed

    Gunawan, David; Sen, D

    2008-01-01

    It is well known that the spectral envelope is a perceptually salient attribute in musical instrument timbre perception. While a number of studies have explored discrimination thresholds for changes to the spectral envelope, the question of how sensitivity varies as a function of center frequency and bandwidth for musical instruments has yet to be addressed. In this paper a two-alternative forced-choice experiment was conducted to observe perceptual sensitivity to modifications made on trumpet, clarinet and viola sounds. The experiment involved attenuating 14 frequency bands for each instrument in order to determine discrimination thresholds as a function of center frequency and bandwidth. The results indicate that perceptual sensitivity is governed by the first few harmonics and sensitivity does not improve when extending the bandwidth any higher. However, sensitivity was found to decrease if changes were made only to the higher frequencies and continued to decrease as the distorted bandwidth was widened. The results are analyzed and discussed with respect to two other spectral envelope discrimination studies in the literature as well as what is predicted from a psychoacoustic model. PMID:18177177

  10. Contrast sensitivity and discrimination of complex scenes

    NASA Astrophysics Data System (ADS)

    Triantaphillidou, S.; Jarvis, J.; Gupta, G.

    2013-01-01

    The aim of our research is to specify experimentally and further model spatial frequency response functions, which quantify human sensitivity to spatial information in real complex images. Three visual response functions are measured: the isolated Contrast Sensitivity Function (iCSF), which describes the ability of the visual system to detect any spatial signal in a given spatial frequency octave in isolation, the contextual Contrast Sensitivity Function (cCSF), which describes the ability of the visual system to detect a spatial signal in a given octave in an image and the contextual Visual Perception Function (VPF), which describes visual sensitivity to changes in suprathreshold contrast in an image. In this paper we present relevant background, along with our first attempts to derive experimentally and further model the VPF and CSFs. We examine the contrast detection and discrimination frameworks developed by Barten, which we find provide a sound starting position for our own modeling purposes. Progress is presented in the following areas: verification of the chosen model for detection and discrimination; choice of contrast metrics for defining contrast sensitivity; apparatus, laboratory set-up and imaging system characterization; stimuli acquisition and stimuli variations; spatial decomposition; methodology for subjective tests. Initial iCSFs are presented and compared with `classical' findings that have used simple visual stimuli, as well as with more recent relevant work in the literature.

  11. Force sensitivity of multilayer graphene optomechanical devices

    NASA Astrophysics Data System (ADS)

    Weber, P.; Güttinger, J.; Noury, A.; Vergara-Cruz, J.; Bachtold, A.

    2016-08-01

    Mechanical resonators based on low-dimensional materials are promising for force and mass sensing experiments. The force sensitivity in these ultra-light resonators is often limited by the imprecision in the measurement of the vibrations, the fluctuations of the mechanical resonant frequency and the heating induced by the measurement. Here, we strongly couple multilayer graphene resonators to superconducting cavities in order to achieve a displacement sensitivity of 1.3 fm Hz-1/2. This coupling also allows us to damp the resonator to an average phonon occupation of 7.2. Our best force sensitivity, 390 zN Hz-1/2 with a bandwidth of 200 Hz, is achieved by balancing measurement imprecision, optomechanical damping, and measurement-induced heating. Our results hold promise for studying the quantum capacitance of graphene, its magnetization, and the electron and nuclear spins of molecules adsorbed on its surface.

  12. Force sensitivity of multilayer graphene optomechanical devices

    PubMed Central

    Weber, P.; Güttinger, J.; Noury, A.; Vergara-Cruz, J.; Bachtold, A.

    2016-01-01

    Mechanical resonators based on low-dimensional materials are promising for force and mass sensing experiments. The force sensitivity in these ultra-light resonators is often limited by the imprecision in the measurement of the vibrations, the fluctuations of the mechanical resonant frequency and the heating induced by the measurement. Here, we strongly couple multilayer graphene resonators to superconducting cavities in order to achieve a displacement sensitivity of 1.3 fm Hz−1/2. This coupling also allows us to damp the resonator to an average phonon occupation of 7.2. Our best force sensitivity, 390 zN Hz−1/2 with a bandwidth of 200 Hz, is achieved by balancing measurement imprecision, optomechanical damping, and measurement-induced heating. Our results hold promise for studying the quantum capacitance of graphene, its magnetization, and the electron and nuclear spins of molecules adsorbed on its surface. PMID:27502017

  13. Calibration of neutron-sensitive devices

    NASA Astrophysics Data System (ADS)

    Gressier, V.; Taylor, G. C.

    2011-12-01

    The calibration of a neutron-sensitive device can range from a simple calibration factor at a single energy or energy distribution to a full response characterization over the entire energy range to which the device is sensitive. As the responses of neutron-sensitive devices and the fluence-to-dose-equivalent conversion coefficients can vary with neutron energy and incident angle, both simulation and experiments in standard neutron fields are required. Although several ISO standards present calibration principles in general and detailed discussion on many specific areas, there are certain omissions and limitations that this paper intends to highlight, along with some new recommendations derived from the recent literature, mainly focused on the effective centre, corrections for geometry and neutron scattering, as well as the problem of calibrating in terms of personal dose equivalent.

  14. Absolute sensitivity calibration of extreme ultraviolet photoresists

    SciTech Connect

    Jones, Juanita; Naulleau, Patrick P.; Gullikson, Eric M.; Aquila, Andrew; George, Simi; Niakoula, Dimitra

    2008-05-16

    One of the major challenges facing the commercialization of extreme ultraviolet (EUV) lithography remains simultaneously achieving resist sensitivity, line-edge roughness, and resolution requirement. Sensitivity is of particular concern owing to its direct impact on source power requirements. Most current EUV exposure tools have been calibrated against a resist standard with the actual calibration of the standard resist dating back to EUV exposures at Sandia National Laboratories in the mid 1990s. Here they report on an independent sensitivity calibration of two baseline resists from the SEMATECH Berkeley MET tool performed at the Advanced Light Source Calibrations and Standards beamline. The results show the baseline resists to be approximately 1.9 times faster than previously thought based on calibration against the long standing resist standard.

  15. Sensitive colorimetric cytotoxicity measurement using alarmar blue.

    PubMed

    Page, B; Page, M

    1995-01-01

    Cytotoxicity testing of anticancer drugs requires techniques which are sensitive, reproductible and applicable to large scale testing using automated instruments. End point staining of cells or viability stains are reliable but they are often not sensitive enough or not suitable for automation. We have already described a fluorometric cytotoxicity assay using a non fluorescent substrate, Alarmar Blue, which upon reduction in living cells, yields a fluorescent product. This assay is sensitive and highly reproductible but it is limited since automated fluorescent plate readers are not found frequently in laboratories. The conditions are now described for using Alamar Blue as a substrate in a colorimetric cytotoxicity assay. This new economical assay could be used with advantage for large scale screening of cytotoxic agents in microtitration plates. PMID:21597689

  16. Chemically sensitive interfaces on SAW devices

    SciTech Connect

    Ricco, A.J.; Martin, S.J.; Crooks, R.M.; Xu, Chuanjing; Allred, R.E.

    1993-11-01

    Using surface acoustic wave (SAW) devices, three approaches to the effective use of chemically sensitive interfaces that are not highly chemically selective have been examined: (1) molecular identification from time-resolved permeation transients; (2) using multifrequency SAW devices to determine the frequency dependence of analyte/film interactions; (3) use of an array of SAW devices bearing diverse chemically sensitive interfaces to produce a distinct response pattern for each analyte. In addition to their well-known sensitivity to mass changes (0.0035 monolayer of N{sub 2} can be measured), SAW devices respond to the mechanical and electronic properties of thin films, enhancing response information content but making a thorough understanding of the perturbation critical. Simultaneous measurement of changes in frequency and attenuation, which can provide the information necessary to determine the type of perturbation, are used as part of the above discrimination schemes.

  17. Critic appraisal. Postoperative sensitivity with indirect restorations.

    PubMed

    Farias, David; Walter, Ricardo; Swift, Edward J

    2014-01-01

    Postoperative sensitivity is characterized by short and sharp pain, and often experienced after cementation of indirect restorations. Factors associated with the occurrence of post-cementation sensitivity include type of cement, removal of smear layer by acid-etching, aggressive tooth preparation, inadequate provisional restorations, and patient's age. Its prevention is based on either interfering with mechanoreceptor activity or occluding the dentinal tubules. Regarding the latter, application of dentin desensitizers may be effective for blocking the tubules and significantly reducing dentin permeability and consequently postoperative sensitivity. This Critical Appraisal will present available clinical data where traditional materials such as zinc phosphate and glass ionomer cements (GIC) as well as self-adhesive resin-based cements were used. PMID:24761824

  18. Causal learning about tolerance and sensitization

    PubMed Central

    Rottman, Benjamin Margolin; Ahn, Woo-kyoung

    2010-01-01

    We introduce two abstract, causal schemata used during causal learning. (1) Tolerance is when an effect diminishes over time, as an entity is repeatedly exposed to the cause (e.g., a person becoming tolerant to caffeine). (2) Sensitization is when an effect intensifies over time, as an entity is repeatedly exposed to the cause (e.g., an antidepressant becoming more effective through repeated use). In Experiment 1, participants observed either of these cause–effect data patterns unfolding over time and exhibiting the tolerance or sensitization schemata. Participants inferred stronger causal efficacy and made more confident and more extreme predictions about novel cases than in a condition with the same data appearing in a random order over time. In Experiment 2, the same tolerance/sensitization scenarios occurred either within one entity or across many entities. In the many-entity conditions, when the schemata were violated, participants made much weaker inferences. Implications for causal learning are discussed. PMID:19966253

  19. Diaphragm based high sensitive FBG pressure sensor

    NASA Astrophysics Data System (ADS)

    Vengal Rao, P.; Srimannarayana, K.; Sai Shankar, M.; Kishore, P.

    2013-06-01

    A high sensitive pressure sensor based on Fiber Bragg grating (FBG) integrated with a thin metal diaphragm was designed and demonstrated. To enhance the pressure sensitivity FBG is firmly glued across the diameter of the diaphragm. Under pressure, the diaphragm deforms and produces an induced strain along the length of the fiber causes shift in Bragg wavelength of the FBG. Pressure measurement is made by measuring the Bragg wavelength shift against change in pressure. The sensor was tested up to the maximum pressure of 140 psi and the corresponding pressure sensitivity was found to be 0.0204 nm/psi, which is approximately 970 times higher than that can be achieved with a bare FBG. The experimental results show good agreement with the theoretical results and possess good linearity and repeatability. This sensor can be used for the measurement of medium pressure, liquid level and depth of underwater.

  20. Ultrahigh humidity sensitivity of graphene oxide

    PubMed Central

    Bi, Hengchang; Yin, Kuibo; Xie, Xiao; Ji, Jing; Wan, Shu; Sun, Litao; Terrones, Mauricio; Dresselhaus, Mildred S.

    2013-01-01

    Humidity sensors have been extensively used in various fields, and numerous problems are encountered when using humidity sensors, including low sensitivity, long response and recovery times, and narrow humidity detection ranges. Using graphene oxide (G-O) films as humidity sensing materials, we fabricate here a microscale capacitive humidity sensor. Compared with conventional capacitive humidity sensors, the G-O based humidity sensor has a sensitivity of up to 37800% which is more than 10 times higher than that of the best one among conventional sensors at 15%–95% relative humidity. Moreover, our humidity sensor shows a fast response time (less than 1/4 of that of the conventional one) and recovery time (less than 1/2 of that of the conventional one). Therefore, G-O appears to be an ideal material for constructing humidity sensors with ultrahigh sensitivity for widespread applications. PMID:24048093

  1. Polycrystalline silicon ion sensitive field effect transistors

    NASA Astrophysics Data System (ADS)

    Yan, F.; Estrela, P.; Mo, Y.; Migliorato, P.; Maeda, H.; Inoue, S.; Shimoda, T.

    2005-01-01

    We report the operation of polycrystalline silicon ion sensitive field effect transistors. These devices can be fabricated on inexpensive disposable substrates such as glass or plastics and are, therefore, promising candidates for low cost single-use intelligent multisensors. In this work we have developed an extended gate structure with a Si3N4 sensing layer. Nearly ideal pH sensitivity (54mV /pH) and stable operation have been achieved. Temperature effects have been characterized. A penicillin sensor has been fabricated by functionalizing the sensing area with penicillinase. The sensitivity to penicillin G is about 10mV/mM, in solutions with concentration lower than the saturation value, which is about 7 mM.

  2. Ethylene synthesis and sensitivity in crop plants

    NASA Technical Reports Server (NTRS)

    Klassen, Stephen P.; Bugbee, Bruce

    2004-01-01

    Closed and semi-closed plant growth chambers have long been used in studies of plant and crop physiology. These studies include the measurement of photosynthesis and transpiration via photosynthetic gas exchange. Unfortunately, other gaseous products of plant metabolism can accumulate in these chambers and cause artifacts in the measurements. The most important of these gaseous byproducts is the plant hormone ethylene (C2H4). In spite of hundreds of manuscripts on ethylene, we still have a limited understanding of the synthesis rates throughout the plant life cycle. We also have a poor understanding of the sensitivity of intact, rapidly growing plants to ethylene. We know ethylene synthesis and sensitivity are influenced by both biotic and abiotic stresses, but such whole plant responses have not been accurately quantified. Here we present an overview of basic studies on ethylene synthesis and sensitivity.

  3. A case of high noise sensitivity

    NASA Astrophysics Data System (ADS)

    Murata, M.; Sakamoto, H.

    1995-10-01

    A case of noise sensitivity with a five-year follow-up period is reported. The patient was a 34-year-old single man who was diagnosed as having psychosomatic disorder triggered by two stressful life events in rapid succession with secondary hypersensitivity to noise. Hypersensitivity to light and cold also developed later in the clinical course. The auditory threshold was within the normal range. The discomfort threshold as a measure of the noise sensitivity secondary to mental illness was measured repeatedly using test tone of audiometry. The discomfort threshold varied depending upon his mental status, ranging from 40-50 dB in the comparatively poorer mental state to 70-95 dB in the relatively good mental state. The features of noise sensitivity, including that secondary to mental illness, are discussed.

  4. Relative planetary radar sensitivities: Arecibo and Goldstone

    NASA Technical Reports Server (NTRS)

    Renzetti, N. A.; Thompson, T. W.; Slade, M. A.

    1988-01-01

    The increase of the Deep Space Network antennas from 64 meter to 70 meter diameter represents the first of several improvements that will be made over the next decade to enhance earth based radar sensitivity to solar system targets. The aperture increase at the Goldstone DSS-14 site, coupled with a proposed increase in transmitter power to 1000 kW, will improve the 3.5 cm radar by about one order of magnitude. Similarly, proposed Arecibo Observatory upgrades of a Gregorian feed structure and an increase of transmitter power to 1000 kW will increase the sensitivity of this radar about 20 fold. In addition, a Goldstone to Very Large Array bistatic observation with horizon to horizon tracking will have 3.5 times more sensitivity than will a Goldstone horizon to horizon monostatic observation. All of these improvements, which should be in place within the next decade, will enrich an already fertile field of planetary exploration.

  5. Interaction between electron-affinic sensitizers.

    PubMed Central

    McNally, J. N.; de Ronde, J.

    1978-01-01

    Measurements of effect of pairs of the sensitizers PNAP, misonidazole and oxygen have shown that if one sensitizer is giving an enhancement ratio (ER) of about 1.6 or less and the other is giving a larger ER, the combination behaves as if only the latter is present. There is only an additive effect of the two if they both give ERs less than 1.6 or greater than 1.6. These results show that at low concentrations sensitizers only act on damage associated with the "fast component" of the oxygen effect. This could result from interaction with two distinct species, or there could be only one critical species formed initially but more than one step by which it could be converted to a lethal form. PMID:277264

  6. Force sensitivity of multilayer graphene optomechanical devices.

    PubMed

    Weber, P; Güttinger, J; Noury, A; Vergara-Cruz, J; Bachtold, A

    2016-01-01

    Mechanical resonators based on low-dimensional materials are promising for force and mass sensing experiments. The force sensitivity in these ultra-light resonators is often limited by the imprecision in the measurement of the vibrations, the fluctuations of the mechanical resonant frequency and the heating induced by the measurement. Here, we strongly couple multilayer graphene resonators to superconducting cavities in order to achieve a displacement sensitivity of 1.3 fm Hz(-1/2). This coupling also allows us to damp the resonator to an average phonon occupation of 7.2. Our best force sensitivity, 390 zN Hz(-1/2) with a bandwidth of 200 Hz, is achieved by balancing measurement imprecision, optomechanical damping, and measurement-induced heating. Our results hold promise for studying the quantum capacitance of graphene, its magnetization, and the electron and nuclear spins of molecules adsorbed on its surface. PMID:27502017

  7. Mapping Seabird Sensitivity to Offshore Wind Farms

    PubMed Central

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N.; Caldow, Richard W. G.; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979–2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species’ ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented. PMID:25210739

  8. High blood pressure and visual sensitivity

    NASA Astrophysics Data System (ADS)

    Eisner, Alvin; Samples, John R.

    2003-09-01

    The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

  9. Biomarkers of exposure, sensitivity and disease

    NASA Technical Reports Server (NTRS)

    Brooks, A. L.

    1999-01-01

    PURPOSE: This review is to evaluate the use of biomarkers as an indication of past exposure to radiation or other environmental insults, individual sensitivity and risk for the development of late occurring disease. OVERVIEW: Biomarkers can be subdivided depending on their applications. Markers of exposure and dose can be used to reconstruct and predict past accidental or occupational exposures when limited or no physical measurements were available. Markers of risk or susceptibility can help identify sensitivity individuals that are at increased risk for development of spontaneous disease and may help predict the increased risk in sensitive individuals associated with environmental or therapeutic radiation exposures. Markers of disease represent the initial cellular or molecular changes that occur during disease development. Each of these types of biomarkers serves a unique purpose. OUTLINE: This paper concentrates on biomarkers of dose and exposure and provides a brief review of biomarkers of sensitivity and disease. The review of biomarkers of dose and exposure will demonstrate the usefulness of biomarkers in evaluation of physical factors associated with radiation exposure, such as LET, doserate and dose distribution. It will also evaluate the use of biomarkers to establish relationships that exist between exposure parameters such as energy deposition, environmental concentration of radioactive materials, alpha traversals and dose. In addition, the importance of biological factors on the magnitude of the biomarker response will be reviewed. Some of the factors evaluated will be the influence of species, tissue, cell types and genetic background. The review will demonstrate that markers of sensitivity and disease often have little usefulness in dose-reconstruction and, by the same token, many markers of dose or exposure may not be applicable for prediction of sensitivity or risk.

  10. Mapping seabird sensitivity to offshore wind farms.

    PubMed

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented. PMID:25210739

  11. Does risk-sensitivity transfer across movements?

    PubMed Central

    O'Brien, Megan K.

    2013-01-01

    An intriguing finding in motor control studies is the marked effect of risk on movement decision making. However, there are inconsistent reports of risk-sensitivity across different movements and tasks, with both risk-seeking and risk-averse behavior observed. This raises the question of whether risk-sensitivity in movement decision making is context dependent and specific to the movement or task being performed. We investigated whether risk-sensitivity transfers between dissimilar movements within a single task. Healthy young adults made arm-reaching movements or whole-body leaning movements to move a cursor as close to the edge of a virtual cliff as possible without moving beyond the edge. They received points on the basis of the cursor's final proximity to the cliff edge. Risk was manipulated by increasing the point penalty associated with the cliff region and/or adding Gaussian noise to the cursor. We compared subjects' movement endpoints with endpoints predicted by a subject-specific, risk-neutral model of movement planning. Subjects demonstrated risk-seeking behavior in both movements that was consistent across risk environments, moving closer to the cliff than the model predicted. However, subjects were significantly more risk-seeking in whole-body movements. Our results present the first evidence of risk-sensitivity in whole-body movements. They also demonstrate that the direction of risk-sensitivity (i.e., risk-seeking or risk-averse) is similar between arm-reaching and whole-body movements, although degree of risk-sensitivity did not transfer from one movement to another. This finding has important implications for the ability of quantitative descriptions of decision making to generalize across movements and, ultimately, decision-making contexts. PMID:23324319

  12. Physical exercise, use of Plantago ovata and aspirin, and reduced risk of colon cancer.

    PubMed

    Juarranz, M; Calle-Purón, M-E; González-Navarro, A; Regidor-Poyatos, E; Soriano, T; Martínez-Hernandez, D; Rojas, V-D; Guinee, V F

    2002-10-01

    To evaluate certain risk and protective factors for colon cancer in our population, we conducted a paired case-control study where cases were all people diagnosed with colon cancer who were registered at the Cancer Data Exchange Systems of the Community of Madrid between January 1995 and December 1996, and controls were randomly taken from electoral lists. The study population consisted of 424 persons. Using SPSS for Windows, variables were adjusted by multiple logistic regression. The results indicate that lack of physical exercise is associated with an increased risk of colon cancer, with an odds ratio (OR) of 2.8 (95% confidence interval (CI) 1.28-6.21) as compared with moderate activity 1-2 days a week. The risk decreases linearly with increasing physical exercise, and this association remains after stratifying the analysis for the existence of constipation. The consumption of is associated with a reduced risk of colon cancer in constipated patients, with an OR of 0.094 (0.014-0.639), as is aspirin use, with an OR of 0.980 (0.898-0.999). These results were obtained after adjusting all the ORs for diet, smoking, alcohol consumption, family history and socio-demographic factors such as marital status and educational level. PMID:12394244

  13. Integrated Arrays of Ion-Sensitive Electrodes

    NASA Technical Reports Server (NTRS)

    Buehler, Martin; Kuhlman, Kimberly

    2003-01-01

    The figure depicts an example of proposed compact water-quality sensors that would contain integrated arrays of ion-sensitive electrodes (ISEs). These sensors would serve as electronic "tongues": they would be placed in contact with water and used to "taste" selected dissolved ions (that is, they would be used to measure the concentrations of the ions). The selected ions could be any or all of a variety of organic and inorganic cations and anions that could be regarded as contaminants or analytes, depending on the specific application. In addition, some of the ISEs could be made sensitive to some neutral analytes

  14. Fabrics Protect Sensitive Skin from UV Rays

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Late Johnson Space Center engineer Dr. Robert Dotts headed a team to develop cool suits for children suffering from life-threatening sun sensitivities. Dotts hoped to develop ultraviolet-blocking technology in a fabric that -- unlike in a bulky space suit -- could remain comfortable, light, and breathable in the sun and heat. The team worked with SPF 4 US LLC (SPF) of Madison, Wisconsin to design ultraviolet-blocking cool suits, which protect sun-sensitive patients and enable them to experience life outdoors safely. Using knowledge gained during the NASA collaboration, SPF created an entire line of ultraviolet-blocking apparel.

  15. High Sensitivity deflection detection of nanowires

    SciTech Connect

    Sanii, Babak; Ashby, Paul

    2009-10-28

    A critical limitation of nanoelectromechanical systems (NEMS) is the lack of a high-sensitivity position detection mechanism. We introduce a noninterferometric optical approach to determine the position of nanowires with a high sensitivity and bandwidth. Its physical origins and limitations are determined by Mie scattering analysis. This enables a dramatic miniaturization of detectable cantilevers, with attendant reductions to the fundamental minimum force noise in highly damping environments. We measure the force noise of an 81{+-}9??nm radius Ag{sub 2}Ga nanowire cantilever in water at 6{+-}3??fN/{radical}Hz.

  16. Grating formation in diazo salt (sensitized) gelatin.

    PubMed

    Gladden, J W

    1980-05-01

    Diazo (sensitized) gelatins are photosensitive recording materials that, unlike dichromated gelatin, have a long shelf life. Because of their stability, the diazo emulsions have replaced the dichromated colloids used in the photolithographic field and enabled commercialization of presensitized printing plates. We have produced plane wave gratings with peak efficiencies near 67% at an exposure of 625 mJ/cm(2) and a recording wavelength of 488.0 nm in one diazo recording material. Called diazo salt (sensitized) gelatin, the photosensitive material produces gratings in gelatin by a complex process that we found not to be a function of exposure. The methods used are described. PMID:20221070

  17. Optimization of measurements with pressure sensitive paints

    NASA Technical Reports Server (NTRS)

    Oglesby, Donald M.; Puram, Chith K.; Upchurch, Billy T.

    1995-01-01

    Use of luminescent paints for the measurement of global pressures on wind tunnel model surfaces requires a full understanding of the inherent accuracy of the technique. Theoretical emission of the paint luminophor follows the well known Stern-Volmer relation. Inherent in this relation are fundamental limits to achievable sensitivity and accuracy. Equations for relative error in pressure as a function of relative signal intensity (emittance), relative error in pressure as a function of pressure, and the relationship between sensitivity and pressure are derived and represented graphically.

  18. Geothermal well cost sensitivity analysis: current status

    SciTech Connect

    Carson, C.C.; Lin, Y.T.

    1980-01-01

    The geothermal well-cost model developed by Sandia National Laboratories is being used to analyze the sensitivity of well costs to improvements in geothermal drilling technology. Three interim results from this modeling effort are discussed. The sensitivity of well costs to bit parameters, rig parameters, and material costs; an analysis of the cost reduction potential of an advanced bit; and a consideration of breakeven costs for new cementing technology. All three results illustrate that the well-cost savings arising from any new technology will be highly site-dependent but that in specific wells the advances considered can result in significant cost reductions.

  19. Phase sensitive Raman process with correlated seeds

    SciTech Connect

    Chen, Bing; Qiu, Cheng; Chen, L. Q. Zhang, Kai; Guo, Jinxian; Yuan, Chun-Hua; Zhang, Weiping; Ou, Z. Y.

    2015-03-16

    A phase sensitive Raman scattering was experimentally demonstrated by injecting a Stokes light seed into an atomic ensemble, whose internal state is set in such a way that it is coherent with the input Stokes seed. Such phase sensitive characteristic is a result of interference effect due to the phase correlation between the injected Stokes light field and the internal state of the atomic ensemble in the Raman process. Furthermore, the constructive interference leads to a Raman efficiency larger than other kinds of Raman processes such as stimulated Raman process with Stokes seed injection alone or uncorrelated light-atom seeding. It may find applications in precision spectroscopy, quantum optics, and precise measurement.

  20. Sensitivity analysis for magnetic induction tomography.

    PubMed

    Soleimani, Manuchehr; Jersey-Willuhn, Karen

    2004-01-01

    This work focuses on sensitivity analysis of magnetic induction tomography in terms of theoretical modelling and numerical implementation. We will explain a new and efficient method to determine the Jacobian matrix, directly from the results of the forward solution. The results presented are for the eddy current approximation, and are given in terms of magnetic vector potential, which is computationally convenient, and which may be extracted directly from the FE solution of the forward problem. Examples of sensitivity maps for an opposite sensor geometry are also shown. PMID:17271947

  1. Fiber specklegram sensors sensitivities at high temperatures

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Lomer, M.; Lopez-Higuera, J. M.

    2015-09-01

    In this work, the sensitivity of Fiber Specklegram Sensors to high temperatures (up to 800ºC) have been studied. Two multimode silica fibers have been introduced into a tubular furnace while a HeNe laser source was launched into a fiber edge, projecting speckle patterns to a commercial webcam. A computer generated different heating and cooling sweeps while the specklegram evolution was recorded. The achieved results exhibit a remarkably linearity in FSS's sensitivity for temperatures under 800ºC, following the thermal expansion of fused silica.

  2. High sensitivity deflection detection of nanowires.

    PubMed

    Sanii, Babak; Ashby, Paul D

    2010-04-01

    A critical limitation of nanoelectromechanical systems (NEMS) is the lack of a high-sensitivity position detection mechanism. We introduce a noninterferometric optical approach to determine the position of nanowires with a high sensitivity and bandwidth. Its physical origins and limitations are determined by Mie scattering analysis. This enables a dramatic miniaturization of detectable cantilevers, with attendant reductions to the fundamental minimum force noise in highly damping environments. We measure the force noise of an 81+/-9 nm radius Ag(2)Ga nanowire cantilever in water at 6+/-3 fN/square root(Hz). PMID:20481957

  3. Lunar magnetic permeability studies and magnetometer sensitivity

    NASA Technical Reports Server (NTRS)

    King, J. H.; Ness, N. F.

    1977-01-01

    A regression of quiet magnetic field components simultaneously measured by the two Explorer 35 magnetometers reveals uncertainties in effective sensitivity factors of up to a few percent in one or both of these instruments. Given this, the validity of previous lunar permeability studies based on Explorer 35/ALSEP regressions, wherein inferences are drawn from regression line slopes differing from unity by the order of one percent, is called into question. We emphasize the need to critically address the question of small deviations in magnetometer sensitivity factors from nominal values as a part of any two-magnetometer lunar permeability study.

  4. Probabilistic sensitivity analysis in health economics.

    PubMed

    Baio, Gianluca; Dawid, A Philip

    2015-12-01

    Health economic evaluations have recently become an important part of the clinical and medical research process and have built upon more advanced statistical decision-theoretic foundations. In some contexts, it is officially required that uncertainty about both parameters and observable variables be properly taken into account, increasingly often by means of Bayesian methods. Among these, probabilistic sensitivity analysis has assumed a predominant role. The objective of this article is to review the problem of health economic assessment from the standpoint of Bayesian statistical decision theory with particular attention to the philosophy underlying the procedures for sensitivity analysis. PMID:21930515

  5. Autoerythrocyte sensitization syndrome presenting with general neurodermatitis

    PubMed Central

    Oh, In Young; Ko, Eun Jung

    2013-01-01

    Autoerythrocyte sensitization syndrome (AES) was first described by Gardner and Diamond in 1955, when four women with painful bruising were depicted. Patients with AES typically present with the development of recurrent, spontaneous, painful ecchymosis, frequently preceded by a prodrome of pain or itching of the skin. The patients are sensitive to their own red blood cells injected intradermally, and underlying coagulopathies are thought to be absent. We introduce a 70-year-old woman presenting with recurrent episodes of painful bruising on the trunk and extremities. PMID:23956968

  6. Observers' sensitivity to dynamic anomalies in collisions

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary Kister; Proffitt, Dennis, R.

    1987-01-01

    The present study examined observers' ability to discriminate canonical and dynamically anomalous collisions that were presented in either frictionless or frictional systems. Whereas previous research has provided qualitative demonstrations that dynamic information can be extracted from visual events, the current study provides a parametric assessment of observers' sensitivity to dynamic invariants. The findings indicate that observers are competent when viewing both familiar, terrestrial (frictional) systems and unfamiliar but computationally simpler, 0-G (frictionless) systems. Thus, the sensitivity to these dynamic invariants in visual events is robust in natural systems whose dynamic properties differ from those of the environment in which humans evolved and developed.

  7. Is Ethical Sensitivity in Teaching Culturally Bound? Comparing Finnish and Iranian Teachers' Ethical Sensitivity

    ERIC Educational Resources Information Center

    Gholami, Khalil; Kuusisto, Elina; Tirri, Kirsi

    2015-01-01

    In this study, we investigated the culture-invariant and culture-dependent nature of teachers' ethical sensitivity in two countries. Our case study involves teachers from Finland (n = 864) representing Western culture, and from Iran (n = 556) representing Eastern culture. Culturally bound elements of ethical sensitivity were studied with the…

  8. Structure of Preschool Phonological Sensitivity: Overlapping Sensitivity to Rhyme, Words, Syllables, and Phonemes.

    ERIC Educational Resources Information Center

    Anthony, Jason L.; Lonigan, Christopher J.; Burgess, Stephen R.; Driscoll, Kimberly; Phillips, Beth M.; Cantor, Brenlee G.

    2002-01-01

    This study examined relations among sensitivity to words, syllables, rhymes, and phonemes in older and younger preschoolers. Confirmatory factor analyses found that a one-factor model best explained the date from both groups of children. Only variance common to all phonological sensitivity skills was related to print knowledge and rudimentary…

  9. Robust Dimensions of Anxiety Sensitivity: Development and Initial Validation of the Anxiety Sensitivity Index-3

    ERIC Educational Resources Information Center

    Taylor, Steven; Zvolensky, Michael J.; Cox, Brian J.; Deacon, Brett; Heimberg, Richard G.; Ledley, Deborah Roth; Abramowitz, Jonathan S.; Holaway, Robert M.; Sandin, Bonifacio; Stewart, Sherry H.; Coles, Meredith; Eng, Winnie; Daly, Erin S.; Arrindell, Willem A.; Bouvard, Martine; Cardenas, Samuel Jurado

    2007-01-01

    Accumulating evidence suggests that anxiety sensitivity (fear of arousal-related sensations) plays an important role in many clinical conditions, particularly anxiety disorders. Research has increasingly focused on how the basic dimensions of anxiety sensitivity are related to various forms of psychopathology. Such work has been hampered because…

  10. Eugenic metal-free sensitizers with double anchors for high performance dye-sensitized solar cells.

    PubMed

    Hung, Wei-I; Liao, You-Ya; Lee, Ting-Hui; Ting, Yu-Chien; Ni, Jen-Shyang; Kao, Wei-Siang; Lin, Jiann T; Wei, Tzu-Chien; Yen, Yung-Sheng

    2015-02-01

    A series of new phenothiazine-based dyes (HL5-HL7) with double acceptors/anchors have been synthesized and used as the sensitizers for highly efficient dye-sensitized solar cells (DSSCs). Among them, the HL7-based cell exhibits the best efficiency of 8.32% exceeding the N719-based cell (7.35%) by ∼13%. PMID:25555237

  11. Differential sensitivity of rat voltage-sensitive sodium channel isoforms to pyrazoline-type insecticides

    SciTech Connect

    Silver, Kristopher S.; Soderlund, David M. . E-mail: dms6@cornell.edu

    2006-07-15

    Pyrazoline-type insecticides are potent inhibitors of insect and mammalian voltage-sensitive sodium channels. In mammals, there are nine sodium channel {alpha} subunit isoforms that have unique distributions and pharmacological properties, but no published data exist that compare the relative sensitivity of these different mammalian sodium channel isoforms to inhibition by pyrazoline-type insecticides. This study employed the Xenopus oocyte expression system to examine the relative sensitivity of rat Na{sub v}1.2a, Na{sub v}1.4, Na{sub v}1.5, and Na{sub v}1.8 sodium channel {alpha} subunit isoforms to the pyrazoline-type insecticides indoxacarb, DCJW, and RH 3421. Additionally, we assessed the effect of coexpression with the rat {beta}1 auxiliary subunit on the sensitivity of the Na{sub v}1.2a and Na{sub v}1.4 isoforms to these compounds. The relative sensitivity of the four sodium channel {alpha} subunits differed for each of the three compounds we examined. With DCJW, the order of sensitivity was Na{sub v}1.4 > Na{sub v}1.2a > Na{sub v}1.5 > Na{sub v}1.8. In contrast, the relative sensitivity of these isoforms to indoxacarb differed from that to DCJW: the Na{sub v}1.8 isoform was most sensitive, the Na{sub v}1.4 isoform was completely insensitive, and the sensitivities of the Na{sub v}1.5 and Na{sub v}1.2a isoforms were intermediate between these two extremes. Moreover, the pattern of sensitivity to RH 3421 among these four isoforms was different from that for either indoxacarb or DCJW: the Na{sub v}1.4 isoform was most sensitive to RH 3421, whereas the sensitivities of the remaining three isoforms were substantially less than that of the Na{sub v}1.4 isoform and were approximately equivalent. The only statistically significant effect of coexpression of either the Na{sub v}1.2a or Na{sub v}1.4 isoforms with the {beta}1 subunit was the modest reduction in the sensitivity of the Na{sub v}1.2a isoform to RH 3421. These results demonstrate that mammalian sodium

  12. New Uses for Sensitivity Analysis: How Different Movement Tasks Effect Limb Model Parameter Sensitivity

    NASA Technical Reports Server (NTRS)

    Winters, J. M.; Stark, L.

    1984-01-01

    Original results for a newly developed eight-order nonlinear limb antagonistic muscle model of elbow flexion and extension are presented. A wider variety of sensitivity analysis techniques are used and a systematic protocol is established that shows how the different methods can be used efficiently to complement one another for maximum insight into model sensitivity. It is explicitly shown how the sensitivity of output behaviors to model parameters is a function of the controller input sequence, i.e., of the movement task. When the task is changed (for instance, from an input sequence that results in the usual fast movement task to a slower movement that may also involve external loading, etc.) the set of parameters with high sensitivity will in general also change. Such task-specific use of sensitivity analysis techniques identifies the set of parameters most important for a given task, and even suggests task-specific model reduction possibilities.

  13. Sensitivity to Sequential Structure in Musical Savants.

    ERIC Educational Resources Information Center

    Miller, Leon K.

    1995-01-01

    Eight pianists with mild to moderate mental retardation and eight comparison pianists without retardation were asked to duplicate chord sequences of varying length and musical structure in an immediate memory format. All participants were sensitive to the structural dimensions of the material, and differences between groups were restricted to the…

  14. Sensitivity to sequential structure in musical savants.

    PubMed

    Miller, L K

    1995-01-01

    Eight pianists with mild to moderate degrees of mental retardation and 8 comparison subjects were asked to duplicate chord sequences of varying length and musical structure in an immediate memory format. All participants were sensitive to the structural dimensions of the material, and differences between groups were restricted to the least structured material. PMID:7695881

  15. Converting sensitive waste into cleaner energy

    SciTech Connect

    Schriner, D.; Skinner, R.

    1997-10-01

    The destruction of sensitive unclassified information (SUI) has always been expensive due to the need for special controls to ensure its protection from disclosure to unauthorized persons. The sensitive documents were shredded, buried at the landfill, or sent to a recycling company. The Department of Energy (DOE) Idaho National Engineering and Environmental Laboratory (INEEL), operated by Lockheed Martin Idaho Technologies Company (LMITCO), has created an innovative method to dispose of its sensitive unclassified paper waste which has security, economic, and environmental benefits. A new cubing facility at the INEEL converts office and industrial waste into compact cubes which are then combined with coal and burned as a source of heat and process steam to run the Idaho Chemical Processing Plant (ICPP) facility. The process-engineered fuel, consisting of 25% cubes and 75% coal, bums cleaner than coal with lower emissions of sulfur dioxide and nitrogen oxides. The alternative fuel also reduces fuel costs, eliminates paying a recycling company, reduces the expense of landfill disposal, increases the life of the landfill, and provides energy to operate a large facility. The Operations Security (OPSEC) team capitalized on this waste to energy technology by recommending that the large quantities of sensitive information (documents) generated at the INEEL be disposed of in this manner. In addition to the economic and environmental benefits, this disposal method minimizes the vulnerabilities of SUI from disclosure to unauthorized personnel. The {open_quotes}cuber{close_quotes} technology has potential application in government and industry for protection of SUI.

  16. The complex problem of sensitive skin.

    PubMed

    Marriott, Marie; Holmes, Jo; Peters, Lisa; Cooper, Karen; Rowson, Matthew; Basketter, David A

    2005-08-01

    There exists within the population subsets of individuals who display heightened skin reactivity to materials the majority find tolerable. In a series of investigations, we have examined interrelationships between many of the endpoints associated with the term 'sensitive skin'. In the most recent work, 58 volunteers were treated with 10% lactic acid, 50% ethanol, 0.5% menthol and 1.0% capsaicin on the nasolabial fold, unoccluded, with sensory reactions recorded at 2.5 min, 5 min and 8 min after application. Urticant susceptibility was evaluated with 1 m benzoic acid and 125 mM trans-cinnamic acid applied to the volar forearm for 20 min. A 2 x 23-h patch test was also conducted using 0.1% and 0.3% sodium dodecyl sulfate, 0.3% and 0.6% cocamidopropyl betaine and 0.1% and 0.2% benzalkonium chloride to determine irritant susceptibility. As found in previous studies, increased susceptibility to one endpoint was not predictive of sensitivity to another. In our experience, nasolabial stinging was a poor predictor of general skin sensitivity. Nevertheless, it may be possible to identify in the normal population individuals who, coincidentally, are more generally sensitive to a range of non-immunologic adverse skin reactions. Whether such individuals are those who experience problems with skin care products remains to be addressed. PMID:16033403

  17. [DIFFERENTIAL SENSITIVITY OF MICROORGANISMS TO POLYHEXAMETHYLENEGUANIDINE].

    PubMed

    Lysytsya, A V; Mandygra, Y M; Bojko, O P; Romanishyna, O O; Mandygra, M S

    2015-01-01

    Factors identified that affect the sensitivity of microorganisms to polyhexamethyleneguanidine (PHMG). Salts of PHMG chloride, valerate, maleate, succinate was to use. Test strains of Esherichia coli, Staphylococcus aureus, Bacillus cereus, Leptospira interrogans, Paenibacillus larvae, Mycobacterium bovis, M. avium, M. fortuitum, Aspergillus niger and some strains of viruses are taken as objects of research. We have determined that the cytoplasm membrane phospholipids is main "target" for the polycation molecules of PHMG. A differential sensitivity of the microorganisms to this drug is primarily determined by relative amount of lipids in membrane and their accessibility. Such trends exist: increase the relative contents of anionic lipids and more negative surface electric potential of membrane, and reduction of the sizes fat acid remainder of lipids bring to increase of microorganism sensitivity. Types of anion salt PHMG just have a certain value. Biocide activity of PHMG chloride is more, than its salts with organic acid. Feasibility of combining PHMG with other biocides in the multicomponent disinfectants studied and analyzed. This combination does not lead to a significant increase in the sensitivity of microorganisms tested in most cases. Most species of pathogenic bacteria can be quickly neutralized by aqueous solutions of PHMG in less than 1% concentrations. PMID:26638480

  18. Sensitivity of Children's Inflection to Grammatical Structure.

    ERIC Educational Resources Information Center

    Kim, John J.; And Others

    1994-01-01

    In four experiments with children aged 3;2 to 8;10, subjects were found more likely to regularize denominal verbs than homophonous irregular verb roots and more likely to regularize exocentric nouns than homophonous irregular endocentric nouns. Children at an early age are sensitive to abstract linguistic notions that underlie adults' linguistic…

  19. Thermal Sensitive Foils in Physics Experiments

    ERIC Educational Resources Information Center

    Bochnícek, Zdenek; Konecný, Pavel

    2014-01-01

    The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

  20. Sensitivity enhancement in pulse EPR distance measurements.

    PubMed

    Jeschke, G; Bender, A; Paulsen, H; Zimmermann, H; Godt, A

    2004-07-01

    Established pulse EPR approaches to the measurement of small dipole-dipole couplings between electron spins rely on constant-time echo experiments to separate relaxational contributions from dipolar time evolution. This requires a compromise between sensitivity and resolution to be made prior to the measurement, so that optimum data are only obtained if the magnitude of the dipole-dipole coupling is known beforehand to a good approximation. Moreover, the whole dipolar evolution function is measured with relatively low sensitivity. These problems are overcome by a variable-time experiment that achieves suppression of the relaxation contribution by reference deconvolution. Theoretical and experimental results show that this approach leads to significant sensitivity improvements for typical systems and experimental conditions. Further sensitivity improvements or, equivalently, an extension of the accessible distance range can be obtained by matrix deuteration or digital long-pass filtering of the time-domain data. Advantages and limitations of the new variable-time experiment are discussed by comparing it to the established analogous constant-time experiment for measurements of end-to-end distances of 5 and 7.5 nm on rod-like shape-persistent biradicals and for the measurement of a broadly distributed transmembrane distance in a doubly spin-labeled mutant of plant light harvesting complex II. PMID:15183350