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Sample records for natural dihydrochalcone induces

  1. Artificial sweetener neohesperidin dihydrochalcone showed antioxidative, anti-inflammatory and anti-apoptosis effects against paraquat-induced liver injury in mice.

    PubMed

    Shi, Qiong; Song, Xiufang; Fu, Juanli; Su, Chuanyang; Xia, Xiaomin; Song, Erqun; Song, Yang

    2015-12-01

    The present study evaluated the protective effect of artificial sweetener neohesperidin dihydrochalcone (NHDC) against paraquat (PQ)-induced acute liver injury in mice. A single dose of PQ (75mg/kg body weight, i.p.) induced acute liver toxicity with the evidences of increased liver damage biomarkers, aspartate transaminase (AST) and alanine transaminase (ALT) activities in serum. Consistently, PQ decreased the antioxidant capacity by reducing glutathione peroxidase (GP-X), glutathione-S-transferase (GST) and catalase (CAT) activities, glutathione (GSH) level and total antioxidant capacity (T-AOC), as well as increasing reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) levels. Histopathological examination revealed that PQ induced numerous changes in the liver tissues. Immunochemical staining assay indicated the upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions. However, NHDC ameliorates PQ-induced hepatic toxicity in mice by reversing these parameters. Additionally, NHDC significantly inhibited PQ-induced nuclear factor-kappa B (NF-κB) expression and mitochondrial-driven apoptotic signaling. TUNEL assay confirmed that PQ-induced apoptosis was relieved by NHDC. In conclusion, these findings suggested that NHDC showed potent antioxidant, anti-inflammatory and anti-apoptotic effects against PQ-induced acute liver damage. PMID:26362205

  2. Neohesperidin dihydrochalcone down-regulates MyD88-dependent and -independent signaling by inhibiting endotoxin-induced trafficking of TLR4 to lipid rafts.

    PubMed

    Xia, Xiaomin; Fu, Juanli; Song, Xiufang; Shi, Qiong; Su, Chuanyang; Song, Erqun; Song, Yang

    2015-12-01

    Fulminant hepatic failure (FHF) is a lethal clinical syndrome characterized by the activation of macrophages and the increased production of inflammatory mediators. The purpose of this study was to investigate the effects of neohesperidin dihydrochalcone (NHDC), a widely-used low caloric artificial sweetener against FHF. An FHF experimental model was established in mice by intraperitoneal injection of D-galactosamine (d-GalN) (400mg/kg)/lipopolysaccharides (LPS) (10 μg/kg). Mice were orally administered NHDC for 6 continuous days and at 1h before d-GalN/LPS administration. RAW264.7 macrophages were used as an in vitro model. Cells were pre-treated with NHDC for 1h before stimulation with LPS (10 μg/ml) for 6h. d-GalN/LPS markedly increased the serum transaminase activities and levels of oxidative and inflammatory markers, which were significantly attenuated by NHDC. Mechanistic analysis indicated that NHDC inhibited LPS-induced myeloid differentiation factor 88 (MyD88) and TIR-containing adapter molecule (TRIF)-dependent signaling. Transient transfection of TLR4 or MyD88 siRNA inhibited the downstream inflammatory signaling. This effect could also be achieved by the pretreatment with NHDC. The fluorescence microscopy and flow cytometry results suggested that NHDC potently inhibited the binding of LPS to TLR4 in RAW264.7 macrophages. In addition, the inhibitory effect of NHDC on LPS-induced translocation of TLR4 into lipid raft domains played an important role in the amelioration of production of downstream pro-inflammatory molecules. Furthermore, the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) by NHDC inhibited TLR4 signaling. In conclusion, our results suggest that NHDC attenuates d-GalN/LPS-induced FHF by inhibiting the TLR4-mediated inflammatory pathway, demonstrating a new application of NHDC as a hepatoprotective agent. PMID:26453923

  3. Artocarpus altilis (Parkinson) Fosberg Extracts and Geranyl Dihydrochalcone Inhibit STAT3 Activity in Prostate Cancer DU145 Cells.

    PubMed

    Jeon, Yoon Jung; Jung, Seung-Nam; Chang, Hyeyoun; Yun, Jieun; Lee, Chang Woo; Lee, Joonku; Choi, Sangho; Nash, Oyekanmi; Han, Dong Cho; Kwon, Byoung-Mog

    2015-05-01

    Artocarpus altilis (Parkinson) Fosberg has traditionally been used in Indonesia for the treatment of liver cirrhosis, hypertension, and diabetes. In many other countries, it is used for the treatment of malaria, yellow fever, and dengue fever. It has been reported that A. altilis extracts have antiatherosclerotic and cytoprotective effects, but its molecular targets in tumor cells are not yet fully understood. The A. altilis extracts and the partially purified fraction have been shown to inhibit STAT3 activity and the phosphorylation of STAT3 in a dose-dependent manner. To identify the active components, a bioassay-guided isolation of the partially purified fraction resulted in the identification of a geranyl dihydrochalcone, CG901. Its chemical structure was established on the basis of spectroscopic evidence and comparison with published data. The partially purified fraction and the isolated a geranyl dihydrochalcone, CG901, down-regulated the expression of STAT3 target genes, induced apoptosis in DU145 prostate cancer cells via caspase-3 and PARP degradation, and inhibited tumor growth in human prostate tumor (DU145) xenograft initiation model. These results suggest that A. altilis could be a good natural source and that the isolated compound will be a potential lead molecule for developing novel therapeutics against STAT3-related diseases, including cancer and inflammation. PMID:25682949

  4. Dihydrochalcones and homoisoflavanes from the red resin of Dracaena cochinchinensis (Chinese dragon's blood).

    PubMed

    Su, Xiao-Qin; Song, Yue-Lin; Zhang, Jing; Huo, Hui-Xia; Huang, Zheng; Zheng, Jiao; Zhang, Qian; Zhao, Yun-Fang; Xiao, Wei; Li, Jun; Tu, Peng-Fei

    2014-12-01

    Two new dihydrochalcones, 4-hydroxy-2,4'-dimethoxydihydrochalcone (1) and 3,4'-dihydroxy-2,4,6-trimethoxydihydrochalcone (2), and a new homoisoflavane, 7,3'-dihydroxy-8,4'-dimethoxyhomoisoflavane (3), along with 12 known compounds (4-15), were isolated from the red resin of Dracaena cochinchinensis (Chinese dragon's blood). Their structures were assigned by a variety of spectroscopic techniques. Diversity of cleavage pathways were proposed for dihydrochalcones and homoisoflavanes based on the mass spectroscopic behaviors of those identified compounds using hybrid ion trap-time of flight mass spectrometry. All the compounds were evaluated for their inhibitory effects on nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages, and compound 9 exhibited mild inhibition of NO production in this assay with IC₅₀ value of 50.3 μM. PMID:25218969

  5. Transglycosylation of neohesperidin dihydrochalcone by Bacillus stearothermophilus maltogenic amylase.

    PubMed

    Cho, J S; Yoo, S S; Cheong, T K; Kim, M J; Kim, Y; Park, K H

    2000-02-01

    Neohesperidin dihydrochalcone (NHDC), a sweet compound derived from citrus fruits, was modified to a series of its oligosaccharides by transglycosylation activity of Bacillus stearothermophilus maltogenic amylase (BSMA). Maltotriose as a donor was reacted with NHDC as an acceptor to glycosylate for the purpose of increasing the solubility of NHDC. Maltosyl-NHDC was a major transglycosylation product among the several transfer products by TLC analysis. The structure of the major transglycosylation product was determined to be maltosyl-alpha-(1,6)-neohesperidin dihydrochalcone by MALDI-TOF/MS and (1)H and (13)C NMR. Maltosyl-NHDC was 700 times more soluble in water and 7 times less sweet than NHDC. PMID:10691608

  6. Geranyl dihydrochalcones from Artocarpus altilis and their antiausteric activity.

    PubMed

    Nguyen, Mai Thanh Thi; Nguyen, Nhan Trung; Nguyen, Khang Duy Huu; Dau, Hien Thu Thi; Nguyen, Hai Xuan; Dang, Phu Hoang; Le, Tam Minh; Nguyen Phan, Trong Huu; Tran, Anh Hai; Nguyen, Bac Duy; Ueda, Jun-Ya; Awale, Suresh

    2014-02-01

    Human pancreatic cancer cell lines have remarkable tolerance to nutrition starvation, which enables them to survive under a tumor microenvironment. The search for agents that preferentially inhibit the survival of cancer cells under low nutrient conditions is a novel antiausterity strategy in anticancer drug discovery. In this study, the methanolic extract of the leaves of Artocarpus altilis showed 100 % preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient-deprived conditions at a concentration of 50 µg/mL. Further investigation of this extract led to the isolation of eight new geranylated dihydrochalcones named sakenins A-H (1-8) together with four known compounds (9-12). Among them, sakenins F (6) and H (8) were identified as potent preferentially cytotoxic candidates with PC50 values of 8.0 µM and 11.1 µM, respectively. PMID:24431013

  7. Histolocalization and physico-chemical characterization of dihydrochalcones: Insight into the role of apple major flavonoids.

    PubMed

    Gaucher, Matthieu; Dugé de Bernonville, Thomas; Lohou, David; Guyot, Sylvain; Guillemette, Thomas; Brisset, Marie-Noëlle; Dat, James F

    2013-06-01

    Flavonoids, like other metabolites synthesized via the phenylpropanoid pathway, possess a wide range of biological activities including functions in plant development and its interaction with the environment. Dihydrochalcones (mainly phloridzin, sieboldin, trilobatin, phloretin) represent the major flavonoid subgroup in apple green tissues. Although this class of phenolic compounds is found in very large amounts in some tissues (≈200mg/g of leaf DW), their physiological significance remains unclear. In the present study, we highlight their tissue-specific localization in young growing shoots suggesting a specific role in important physiological processes, most notably in response to biotic stress. Indeed, dihydrochalcones could constitute a basal defense, in particular phloretin which exhibits a strong broad-range bactericidal and fungicidal activity. Our results also indicate that sieboldin forms complexes with iron with strong affinity, reinforcing its antioxidant properties and conferring to this dihydrochalcone a potential for iron seclusion and/or storage. The importance of localization and biochemical properties of dihydrochalcones are discussed in view of the apple tree defense strategy against both biotic and abiotic stresses. PMID:23562371

  8. Quantitation of flavanols, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and benzoic Acid derivatives after identification by LC-MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A general method was developed for the systematic quantitation of catechins, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and hydroxybenzoic acid derivatives (mainly hydrolyzable tannins) using the UV relative mole response factors (MRRF) of the reference standard from ea...

  9. Structure-Activity Relationships of Retro-dihydrochalcones Isolated from Tacca sp

    PubMed Central

    Peng, Jiangnan; Risinger, April L.; Da, Chenxiao; Fest, Gary A.; Kellogg, Glen E.; Mooberry, Susan L.

    2014-01-01

    Several biologically active compounds have been identified from Tacca species, including glycosides, diarylheptanoids, saponins, withanolides, and the taccalonolide class of microtubule stabilizers. More recently, two cytotoxic retro-dihydrochalcones named evelynin A (7) and taccabulin A (6) were isolated and their biological activities characterized, including the finding that taccabulin has microtubule destabilizing effects. Here we describe the identification and characterization of five new retro-chalcones, named taccabulins B – E (1–4) and evelynin B (5) from Tacca sp. extracts. Their structures were determined using 1D and 2D NMR as well as mass spectroscopic data and modeled into the colchicine binding site of tubulin. The antiproliferative and microtubule effects of each compound were determined experimentally and found to be well correlated with modeling studies. The isolation and biological characterization of several retro-dihydrochalcones facilitated preliminary structure-activity relationships for this compound class concerning its antiproliferative and microtubule depolymerizing activities. PMID:24303844

  10. An unusual homoisoflavanone and a structurally-related dihydrochalcone from Polygonum ferrugineum (Polygonaceae).

    PubMed

    López, Silvia N; Sierra, Manuel Gonzalez; Gattuso, Susana J; Furlán, Ricardo L; Zacchino, Susana A

    2006-10-01

    The homoisoflavanone 5,7-dihydroxy-6-methoxy-3-(9-hydroxy-phenylmethyl)-chroman-4-one (1) and its structurally related 2',4',6'-trihydroxy-3'-methoxy-alpha-hydroxymethyl-beta-hydroxy-dihydrochalcone (2) along with the known pashanone (3), flavokawin B (4) and cardamonin or alpinetin chalcone (5) pinostrobin (6) and 5,8-dimethoxy-7-hydroxychroman-4-one (7) were isolated from dry leaves of Polygonum ferrugineum (Polygonaceae). To our knowledge, this is the first report of the isolation of a homoisoflavanone from the Polygonum genus and the Polygonaceae family, and could be an important chemotaxonomic finding. In addition, the pattern of substitution of this homoisoflavanone is different from others previously reported. PMID:16884749

  11. Replacement of the methylene of dihydrochalcones with oxygen: synthesis and biological evaluation of 2-phenoxyacetophenones.

    PubMed

    Ansari, Mahsa; Emami, Saeed; Khalilzadeh, Mohammad A; Maghsoodlou, Malek T; Foroumadi, Alireza; Faramarzi, Mohammad A; Samadi, Nasrin; Ardestani, Sussan K

    2012-10-01

    With the aim of finding new bioactive compounds, a series of phenoxyacetophenone derivatives 2 were designed and synthesized as oxygen analogs of dihydrochalcones. Also, phenoxyacetophenones were converted to (Z)-oxime derivatives 3 and their geometry were characterized by ¹H-NMR spectroscopy. The in vitro antifungal activity of compounds 2 and 3 was evaluated against Candida albicans, Candida glabrata, Saccharomyces cerevisiae, and Aspergillus niger using micro-dilution method. In general, oxime derivative 3d containing 4-fluorophenoxy moiety showed comparable or more potent antifungal activity (MICs = 15.63-31.25 μg/mL) with respect to the reference drug fluconazole against all tested yeasts. In addition, the antileishmanial activity of title compounds was determined against pormastigote form of Leishmania major. All compounds showed mild growth inhibitory activity against promastigotes. The most active compound was unsubstituted phenoxyacetophenone 2a (IC₅₀ = 80 μg/mL). To anticipate the potential use as drugs, the target compounds were evaluated in their drug-like properties. The in silico values of molecular descriptors for bioactive compounds 2a and 3d revealed that these compounds are within the range set by Lipinski's 'Rule of 5' and show no violation of these rules. Moreover, bioactive compounds 2a and 3d are supposed to be non-mutagenic and non-tumorigenic, with no irritating or reproductive effects. PMID:22712717

  12. Brane induced gravity: Ghosts and naturalness

    NASA Astrophysics Data System (ADS)

    Eglseer, Ludwig; Niedermann, Florian; Schneider, Robert

    2015-10-01

    Linear stability of brane induced gravity in two codimensions on a static pure tension background is investigated. The brane is regularized as a ring of finite circumference in extra space. By explicitly calculating the vacuum persistence amplitude of the corresponding quantum theory, we show that the parameter space is divided into two regions—one corresponding to a stable Minkowski vacuum on the brane and one being plagued by ghost instabilities. This analytical result affirms a recent nonlinear, but mainly numerical analysis. The main result is that the ghost is absent for a sufficiently large brane tension, in perfect agreement with a value expected from a natural effective field theory point of view. Unfortunately, the linearly stable parameter regime is either ruled out phenomenologically or becomes unstable for nontrivial cosmologies. We argue that supercritical brane backgrounds constitute the remaining window of opportunity. In the special case of a tensionless brane, we find that the ghost exists for all phenomenologically relevant values of the induced gravity scale. Regarding this case, there are contradicting results in the literature, and we are able to fully resolve this controversy by explicitly uncovering the errors made in the "no-ghost" analysis. Finally, a Hamiltonian analysis generalizes the ghost result to more than two codimensions.

  13. Effect of neohesperidin dihydrochalcone on the activity and stability of alpha-amylase: a comparative study on bacterial, fungal, and mammalian enzymes.

    PubMed

    Kashani-Amin, Elaheh; Ebrahim-Habibi, Azadeh; Larijani, Bagher; Moosavi-Movahedi, Ali Akbar

    2015-10-01

    Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha-amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha-amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha-amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha-amylase surface in domain B. This domain shows differences in various alpha-amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact. PMID:25808616

  14. Quantitation of Flavanols, Proanthocyanidins, Isoflavones, Flavanones, Dihydrochalcones, Stilbenes, Benzoic Acid Derivatives Using Ultraviolet Absorbance after Identification by Liquid Chromatography–Mass Spectrometry

    PubMed Central

    Lin, Long-Ze; Harnly, James M.

    2013-01-01

    A general method was developed for the systematic quantitation of flavanols, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and hydroxybenzoic acid derivatives (mainly hydrolyzable tannins) based on UV band II absorbance arising from the benzoyl structure. The compound structures and the wavelength maximum were well correlated and were divided into four groups: the flavanols and proanthocyanidins at 278 nm, hydrolyzable tannins at 274 nm, flavanones at 288 nm, and isoflavones at 260 nm. Within each group, molar relative response factors (MRRFs) were computed for each compound based on the absorbance ratio of the compound and the group reference standard. Response factors were computed for the compounds as purchased (MRRF), after drying (MRRFD), and as the best predicted value (MRRFP). Concentrations for each compound were computed based on calibration with the group reference standard and the MRRFP. The quantitation of catechins, proanthocyanidins, and gallic acid derivatives in white tea was used as an example. PMID:22577798

  15. Pressure-induced diffusion in natural garnets

    NASA Astrophysics Data System (ADS)

    Floess, David; Vrijmoed, Johannes; Baumgartner, Lukas; Podladchikov, Yuri

    2015-04-01

    Recent efforts in metamorphic petrology suggest that significant pressure gradients exist on the grain-scale and provide tools for its quantification [1,2]. Here we propose that pressure gradients around coesite inclusions induced diffusion of major elements within garnet crystals upon exhumation. This is based on the fact that the molar mass of garnet endmembers vary between 403 and 497 g/mol, thus up to 23 %. Whiteschists from the Dora Maira Massive in the Western Alps underwent eclogite facies metamorphism (3.3-4.3 GPa, 720-780 °C) during the Alpine event at 35 Ma [3]. Coesite included in garnet (py0.96gr0.02alm0.02) during the HP stage was partially transformed to quartz during the subsequent, rapid exhumation (from 3.5 to 1 GPa within 2 Ma [4]). Coesite is preserved by maintaining a high pressure on the inclusion wall due to the large volume change of the phase transition. The surface of the host garnet experiences a lower pressure controlled by the exhumation P-T path. This pressure difference should induce diffusion of major elements in the garnet surrounding the inclusion. Element distribution maps show well-defined Fe-rich, Ca-poor halos surrounding the coesite-inclusions. The observed diffusion profiles are in agreement with predictions, assuming a positive ΔP around the inclusions. The results are based on thermodynamic equilibrium calculations assuming heterogeneous pressure [5]. Hence, the observed profiles are interpreted as an equilibrium state reflecting the pressure (stress) distribution within the crystal and can be used as tool to constrain the exhumation path. Understanding the effect of pressure gradients on diffusion and, alternatively, the generation of pressure due to relaxation of chemical gradients by diffusion, is crucial for interpreting P-T-t paths of zoned minerals correctly. [1] Baumgartner et al. (2010), GSA meeting Denver. [2] Tajčmanová et al. (2014) CMP 32, 195-207. [3] Compagnoni & Rolfo (2003), UHP Metamorphism - EMU notes 5

  16. Natural and Induced Environment in Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Badavi, Francis F.; Kim, Myung-Hee Y.; Clowdsley, Martha S.; Heinbockel, John H.; Cucinotta, Francis A.; Badhwar, Gautam D.; Atwell, William; Huston, Stuart L.

    2002-01-01

    The long-term exposure of astronauts on the developing International Space Station (ISS) requires an accurate knowledge of the internal exposure environment for human risk assessment and other onboard processes. The natural environment is moderated by the solar wind which varies over the solar cycle. The neutron environment within the Shuttle in low Earth orbit has two sources. A time dependent model for the ambient environment is used to evaluate the natural and induced environment. The induced neutron environment is evaluated using measurements on STS-31 and STS-36 near the 1990 solar maximum.

  17. Thermally induced natural convection effects in Yucca Mountain drifts.

    PubMed

    Webb, Stephen W; Francis, Nicholas D; Dunn, Sandra Dalvit; Itamura, Michael T; James, Darryl L

    2003-01-01

    Thermally induced natural convection from the heat produced by emplaced waste packages is an important heat and mass transfer mechanism within the Yucca Mountain Project (YMP) drifts. Various models for analyzing natural convection have been employed. The equivalent porous medium approach using Darcy's law has been used in many YMP applications. However, this approach has questionable fidelity, especially for turbulent flow conditions. Computational fluid dynamics (CFD), which is based on the fundamental Navier-Stokes equations, is currently being evaluated as a technique to calculate thermally induced natural convection in YMP. Data-model comparisons for turbulent flow conditions show good agreement of CFD predictions with existing experiments including YMP-specific data. PMID:12714318

  18. Quantifying the Seismic Hazard From Natural and Induced Earthquakes (Invited)

    NASA Astrophysics Data System (ADS)

    Rubinstein, J. L.; Llenos, A. L.; Ellsworth, W. L.; McGarr, A.; Michael, A. J.; Mueller, C. S.; Petersen, M. D.

    2013-12-01

    In the past 12 years, seismicity rates in portions of the central and eastern United States (CEUS) have increased. In 2011, the year of peak activity, three M ≥ 5 earthquakes occurred, causing millions of dollars in damage. Much of the increase in seismicity is believed to have been induced by wastewater from oil and gas activity that is injected deep underground. This includes damaging earthquakes in southern Colorado, central Arkansas, and central Oklahoma in 2011. Earthquakes related to oil and gas activities contribute significantly to the total seismic hazard in some areas of the CEUS, but most of the tens of thousands of wastewater disposal wells in the CEUS do not cause damaging earthquakes. The challenge is to better understand this contribution to the hazard in a realistic way for those wells that are inducing earthquakes or wells that may induce earthquakes in the future. We propose a logic-tree approach to estimate the hazard posed by the change in seismicity that deemphasizes the need to evaluate whether the seismicity is natural or man-made. We first compile a list of areas of increased seismicity, including areas of known induced earthquakes. Using areas of increased seismicity (instead of just induced earthquakes) allows us to assess the hazard over a broader region, avoiding the often-difficult task of judging whether an earthquake sequence is induced. With the zones of increased seismicity defined, we then estimate the earthquake hazard for each zone using a four-branch logic tree: (1) The increased seismicity rate is natural, short-term variation within the longer-term background seismicity rate. Thus, these earthquakes would be added to the catalog when computing the background seismicity rate. (2) The increased seismicity rate represents a new and permanent addition to the background seismicity. In this branch, a new background seismicity rate begins at the time of the change in earthquake rate. (3) Induced earthquakes account for the

  19. Supersonic Jet Mixing Enhancement due to Natural and Induced Screech

    NASA Technical Reports Server (NTRS)

    Rice, E. J.; Raman, G.

    1999-01-01

    Outline of presentation are: (1) Review of experimental apparatus. (2) Effect of natural screech of jet mixing; converging nozzle, underexpanded jet and converging-diverging nozzle, design pressure.(3) Effect of induced screech on jet mixing: produced by paddles in shear layers, similar to edge tones, and converging-diverging nozzle, design pressure. (4) Effect of paddles on near-field jet noise. and (5) Concluding remarks.

  20. Interferon induces natural killer cell blastogenesis in vivo

    NASA Technical Reports Server (NTRS)

    Biron, C. A.; Sonnenfeld, G.; Welsh, R. M.

    1984-01-01

    Interferon (IFN), types beta and gamma, and IFN inducers polyinosinic-polycytidylic acid and lymphocytic choriomeningitis virus, all stimulated the generation of blast-natural killer (NK) cells in mouse spleens, Blast-NK cells were characterized on the basis of size, 3H-thymidine uptake, and NK cell markers These data indicate that in addition to augmenting NK cell-mediated lysis, IFN may regulate NK cell proliferation in vivo.

  1. Dephasing-Induced Control of Interference Nature in Three-Level Electromagnetically Induced Tansparency Systems

    PubMed Central

    Sun, Yong; Yang, Yaping; Chen, Hong; Zhu, Shiyao

    2015-01-01

    The influence of the dephasing on interference is investigated theoretically and experimentally in three-level electromagnetically induced transparency systems. The nature of the interference, constructive, no interference or destructive, can be controlled by adjusting the dephasing rates. This new phenomenon is experimentally observed in meta-atoms. The physics behind the dephasing-induced control of interference nature is the competing between stimulated emission and spontaneous emission. The random phase fluctuation due to the dephasing will result in the correlation and anti-correlation between the two dressed states, which will enhance and reduce the stimulated emission, respectively. PMID:26567708

  2. Toughening effect of strain-induced crystallites in natural rubber.

    PubMed

    Zhang, H P; Niemczura, J; Dennis, G; Ravi-Chandar, K; Marder, M

    2009-06-19

    We study fracture propagation in stretched natural rubber sheets. Experimental results in specimens stretched less than 3.8 times show a monotonic increase in the crack speed with stretch and can be explained by a numerical model based on neo-Hookean theory and Kelvin dissipation. In specimens stretched more than 3.8 times, strain-induced crystallites act as reinforcing and toughening fillers and significantly increase fracture resistance, like nanostructures in other polymeric or biological materials. Consequently, as we increase the amount of stretch, fractures travel slower and slower, and eventually halt altogether. PMID:19659026

  3. Toughening Effect of Strain-Induced Crystallites in Natural Rubber

    NASA Astrophysics Data System (ADS)

    Zhang, H. P.; Niemczura, J.; Dennis, G.; Ravi-Chandar, K.; Marder, M.

    2009-06-01

    We study fracture propagation in stretched natural rubber sheets. Experimental results in specimens stretched less than 3.8 times show a monotonic increase in the crack speed with stretch and can be explained by a numerical model based on neo-Hookean theory and Kelvin dissipation. In specimens stretched more than 3.8 times, strain-induced crystallites act as reinforcing and toughening fillers and significantly increase fracture resistance, like nanostructures in other polymeric or biological materials. Consequently, as we increase the amount of stretch, fractures travel slower and slower, and eventually halt altogether.

  4. Nature of radiation-induced defects in quartz

    SciTech Connect

    Wang, Bu; Yu, Yingtian; Bauchy, Mathieu; Pignatelli, Isabella; Sant, Gaurav

    2015-07-14

    Although quartz (α-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage has not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si–O connectivity defects, e.g., small Si–O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on E′ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.

  5. Nature of radiation-induced defects in quartz

    NASA Astrophysics Data System (ADS)

    Wang, Bu; Yu, Yingtian; Pignatelli, Isabella; Sant, Gaurav; Bauchy, Mathieu

    2015-07-01

    Although quartz (α-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage has not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si-O connectivity defects, e.g., small Si-O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on E' centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.

  6. Laser-Induced Acoustic Desorption of Natural and Functionalized Biochromophores

    PubMed Central

    2015-01-01

    Laser-induced acoustic desorption (LIAD) has recently been established as a tool for analytical chemistry. It is capable of launching intact, neutral, or low charged molecules into a high vacuum environment. This makes it ideally suited to mass spectrometry. LIAD can be used with fragile biomolecules and very massive compounds alike. Here, we apply LIAD time-of-flight mass spectrometry (TOF-MS) to the natural biochromophores chlorophyll, hemin, bilirubin, and biliverdin and to high mass fluoroalkyl-functionalized porphyrins. We characterize the variation in the molecular fragmentation patterns as a function of the desorption and the VUV postionization laser intensity. We find that LIAD can produce molecular beams an order of magnitude slower than matrix-assisted laser desorption (MALD), although this depends on the substrate material. Using titanium foils we observe a most probable velocity of 20 m/s for functionalized molecules with a mass m = 10 000 Da. PMID:25946522

  7. Caloric restriction mimetics: natural/physiological pharmacological autophagy inducers

    PubMed Central

    Mariño, Guillermo; Pietrocola, Federico; Madeo, Frank; Kroemer, Guido

    2014-01-01

    Nutrient depletion, which is one of the physiological triggers of autophagy, results in the depletion of intracellular acetyl coenzyme A (AcCoA) coupled to the deacetylation of cellular proteins. We surmise that there are 3 possibilities to mimic these effects, namely (i) the depletion of cytosolic AcCoA by interfering with its biosynthesis, (ii) the inhibition of acetyltransferases, which are enzymes that transfer acetyl groups from AcCoA to other molecules, mostly leucine residues in cellular proteins, or (iii) the stimulation of deacetylases, which catalyze the removal of acetyl groups from leucine residues. There are several examples of rather nontoxic natural compounds that act as AcCoA depleting agents (e.g., hydroxycitrate), acetyltransferase inhibitors (e.g., anacardic acid, curcumin, epigallocatechin-3-gallate, garcinol, spermidine) or deacetylase activators (e.g., nicotinamide, resveratrol), and that are highly efficient inducers of autophagy in vitro and in vivo, in rodents. Another common characteristic of these agents is their capacity to reduce aging-associated diseases and to confer protective responses against ischemia-induced organ damage. Hence, we classify them as “caloric restriction mimetics” (CRM). Here, we speculate that CRM may mediate their broad health-improving effects by triggering the same molecular pathways that usually are elicited by long-term caloric restriction or short-term starvation and that imply the induction of autophagy as an obligatory event conferring organismal, organ- or cytoprotection. PMID:25484097

  8. Natural history of food protein-induced enterocolitis syndrome

    PubMed Central

    Katz, Yitzhak; Goldberg, Michael R.

    2014-01-01

    Purpose of review Because of the paucity of reports and variability in the diagnostic criteria utilized, little is known regarding the natural outcome of patients with food protein-induced enterocolitis syndrome (FPIES). Data extracted from referenced manuscripts, as well as allergists’ unpublished observations from across the globe, were used to form a cohesive opinion regarding its natural outcome. Recent findings All authors concur that there is a generally high rate of recovery for FPIES. The most common foods causing FPIES are milk and soy. Depending upon which study is analyzed, by the age of 3–5 years, approximately 90% of patients recover from their disease. Recovery from FPIES to solid foods, occurs at a later age, but may reflect a later stage of introduction of the food into the diet. An important clinical outcome, although not common, is a shift from FPIES food hypersensitivity to an IgE-mediated food allergy. This necessitates a change in the oral food challenge protocol, if IgE-mediated sensitization is detected. Summary Over the past several years, there has been an increasing awareness of FPIES. This knowledge should lead to a more timely diagnosis and should reassure parents and practitioners alike regarding its favorable course. PMID:24686278

  9. Natural and induced collapse and caprock dolines hazard, Karapinar, Turkey

    NASA Astrophysics Data System (ADS)

    Doǧan, Uǧur; Yılmaz, Mutlu

    2010-05-01

    The number collapse and caprock dolines (locally known as obruk) has increased rapidly in recent years in the near of Karapınar, located in the semi-arid Konya Basin in the Central Anatolia. 19 dolines formed in the last 32 years (1977-2009), as a result of the collapse of conduit roofs in the Neogene lacustrine limestone in the Obruk Plateau and Karapınar Plain. Of these, 13 formed within the past 4 years (2006-2009). The Obruk Plateau takes its name from the presence of several hundred palaeo-dolines which formed as a result of natural process during the Quaternary. More recently, human activity has also induced the formation of new dolines, which present a risk to life and property. Changing agricultural patterns have led to the opening of thousands of wells in recent years, and increased water pumping currently exceeds the sustainable yield of the aquifer. Accordingly, the formation of dolines has triggered due to a combination of natural and human effect. The groundwater level has falling almost 24 m in the vicinity of Karapınar during the last 30 years. Legally-binding precautions must be taken to prevent further water table decline, in order to prevent potential dolines formations within the basin in coming years.

  10. Natural and induced T regulatory cells in cancer.

    PubMed

    Adeegbe, Dennis O; Nishikawa, Hiroyoshi

    2013-01-01

    CD4+Foxp3+ T regulatory (Treg) cells control many facets of immune responses ranging from autoimmune diseases, to inflammatory conditions, and cancer in an attempt to maintain immune homeostasis. Natural Treg (nTreg) cells develop in the thymus and constitute a critical arm of active mechanisms of peripheral tolerance particularly to self antigens. A growing body of knowledge now supports the existence of induced Treg (iTreg) cells which may derive from a population of conventional CD4+ T cells. The fork-head transcription factor (Foxp3) typically is expressed by natural CD4+ Treg cells, and thus serves as a marker to definitively identify these cells. On the contrary, there is less consensus on what constitutes iTreg cells as their precise definition has been somewhat elusive. This is in part due to their distinct phenotypes which are shaped by exposure to certain inflammatory or "assault" signals stemming from the underlying immune disorder. The "policing" activity of Treg cells tends to be uni-directional in several pathological conditions. On one end of the spectrum, Treg cell suppressive activity is beneficial by curtailing T cell response against self-antigens and allergens thus preventing autoimmune diseases and allergies. On the other end however, their inhibitory roles in limiting immune response against pseudo-self antigens as in tumors often culminates into negative outcomes. In this review, we focus on this latter aspect of Treg cell immunobiology by highlighting the involvement of nTreg cells in various animal models and human tumors. We further discuss iTreg cells, relationship with their natural counterpart, and potential co-operation between the two in modulating immune response against tumors. Lastly, we discuss studies focusing on these cells as targets for improving anti-tumor immunity. PMID:23874336

  11. Natural and induced reduction of hexavalent chromium in soil

    NASA Astrophysics Data System (ADS)

    Leita, Liviana; Margon, Alja; Sinicco, Tania; Mondini, Claudio; Valentini, Massimiliano; Cantone, Pierpaolo

    2013-04-01

    Even though naturally elevated levels of chromium can be found naturally in some soils, distressing amounts of the hexavalent form (CrVI) are largely restricted to sites contaminated by anthropogenic activities. In fact, the widespread use of chromium in various industries and the frequently associated inadequate disposal of its by-products and wastes have created serious environmental pollution problems in many parts of the world. CrVI is toxic to plants, animals and humans and exhibits also mutagenic effects. However, being a strong oxidant, CrVI can be readily reduced to the much less harmful trivalent form (CrIII) when suitable electron donors are present in the environment. CrIII is relatively insoluble, less available for biological uptake, and thus definitely less toxic for web-biota. Various electron donors in soil can be involved in CrVI reduction in soil. The efficiency of CrVI reducing abiotic agents such as ferrous iron and sulphur compounds is well documented. Furthermore, CrVI reduction is also known to be significantly enhanced by a wide variety of cell-produced monosaccharides, including glucose. In this study we evaluated the dynamics of hexavalent chromium (CrVI) reduction in contaminated soil amended or not with iron sulphate or/and glucose and assessed the effects of CrVI on native or glucose-induced soil microbial biomass size and activity. CrVI negatively affected both soil microbial activity and the size of the microbial biomass. During the incubation period, the concentration of CrVI in soil decreased over time whether iron sulphate or/and glucose was added or not, but with different reduction rates. Soil therefore displayed a natural attenuation capacity towards chromate reduction. Addition of iron sulphate or/and glucose, however, increased the reduction rate by both abiotic and biotic mechanisms. Our data suggest that glucose is likely to have exerted an indirect role in the increased rate of CrVI reduction by promoting growth of

  12. Mapping Microbial Response Metabolomes for Induced Natural Product Discovery.

    PubMed

    Derewacz, Dagmara K; Covington, Brett C; McLean, John A; Bachmann, Brian O

    2015-09-18

    Intergeneric microbial interactions may originate a significant fraction of secondary metabolic gene regulation in nature. Herein, we expose a genomically characterized Nocardiopsis strain, with untapped polyketide biosynthetic potential, to intergeneric interactions via coculture with low inoculum exposure to Escherichia, Bacillus, Tsukamurella, and Rhodococcus. The challenge-induced responses of extracted metabolites were characterized via multivariate statistical and self-organizing map (SOM) analyses, revealing the magnitude and selectivity engendered by the limiting case of low inoculum exposure. The collected inventory of cocultures revealed substantial metabolomic expansion in comparison to monocultures with nearly 14% of metabolomic features in cocultures undetectable in monoculture conditions and many features unique to coculture genera. One set of SOM-identified responding features was isolated, structurally characterized by multidimensional NMR, and revealed to comprise previously unreported polyketides containing an unusual pyrrolidinol substructure and moderate and selective cytotoxicity. Designated ciromicin A and B, they are detected across mixed cultures with intergeneric preferences under coculture conditions. The structural novelty of ciromicin A is highlighted by its ability to undergo a diastereoselective photochemical 12-π electron rearrangement to ciromicin B at visible wavelengths. This study shows how organizing trends in metabolomic responses under coculture conditions can be harnessed to characterize multipartite cultures and identify previously silent secondary metabolism. PMID:26039241

  13. Worksheet-Induced Behaviour in the British Museum (Natural History).

    ERIC Educational Resources Information Center

    McManus, Paulette

    1985-01-01

    A survey of how worksheets are used by groups of children in the British Museum (Natural History) is described. Arising from the survey, some guidelines are offered for those compiling worksheets for use with out-of-school activities. (Author)

  14. Space Shuttle externally induced environment compared with Skylab's natural environment

    NASA Technical Reports Server (NTRS)

    Susko, Michael

    1990-01-01

    Electret measurements obtained of the particulate contamination environment within the Space Shuttle Orbiter's cargo bay are presently compared with ground measurements of the particulates emitted by the Shuttle's SRBs, as well as with the expected natural particulate environment as measured by Skylab. Chemical analysis is shown to reveal the difference between natural and anthropogenic space debris; the most probable primary source of the Space Shuttle's particulate environment is the SRB exhaust.

  15. Natural and Human-induced Disturbances and Their Impacts on Forest Carbon Budgets in North America

    NASA Astrophysics Data System (ADS)

    Pan, Y.; Birdsey, R.; Chen, J. M.; McCullough, K.; Zhang, F.

    2014-12-01

    Natural and human-induced disturbances have profound impacts on forest carbon dynamics, and may cause the greatest uncertainty in estimating forest carbon budgets. In North America, three countries show very different forest disturbance patterns: Canadian forests are dominated by natural disturbances such as wildfires and insect outbreaks; forests of Mexico are more affected by human-induced land disturbances such as land-use change; while US forests are equally affected by human-induced and natural disturbances. As human-induced disturbances are closely linked to socioeconomic factors, natural disturbances are usually viewed as a natural process in forests and have equilibrium impacts on forests over the long run. However, with climate change and related changes in natural disturbance regimes in terms of frequency, intensity and scale, there are now fundamental changes in the nature of the impact of natural disturbances on forest carbon dynamics and even greater uncertainty about forest carbon budgets and feedbacks to the atmosphere and climate. In this study, we synthesize disturbance information for North America based on existing remote-sensing products, ground-based observations and modeling studies, evaluating impacts of disturbances on forest carbon budgets that are relevant to disturbance types, scales, frequency and intensity. The work represents the initial step of a more ambitious project tackling this research challenge for North America that crosses a broad climate gradient and diverse socioeconomic entities. The goal is to ultimately improve the estimates of forest carbon budgets and their potential for climate mitigation under changing environments.

  16. Lichen symbiosis: nature's high yielding machines for induced hydrogen production.

    PubMed

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont's and photobiont's consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont's hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications. PMID:25826211

  17. Lichen Symbiosis: Nature's High Yielding Machines for Induced Hydrogen Production

    PubMed Central

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont’s and photobiont’s consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont’s hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications. PMID:25826211

  18. Natural and Laboratory-Induced Compaction Bands in Aztec Sandstone

    NASA Astrophysics Data System (ADS)

    Haimson, B. C.; Lee, H.

    2002-12-01

    The Aztec sandstone used in this research is from the Valley of Fire State Park area, Nevada. This Jurassic aeolian sandstone is extremely weak (uniaxial compressive strength of 1-2 MPa); porosity averages 26%; grains are subrounded and have a bimodal size distribution (0.1 mm and 0.5 mm); its mineral composition (K. Sternlof, personal comm.) is 93% quartz, 5% k-spar, and 2% kaolinite, Fe carbonate and others; grain bonding is primarily through suturing. Sternlof et al. (EOS, November, 2001) observed substantial exposure of mainly compactive deformation bands in the Aztec sandstone. We studied an SEM image of a compaction band found in a hand sample of the Aztec sandstone. We also conducted a drilling test in a 130x130x180 mm prismatic specimen subjected to a preset far-field true triaxial stress condition (\\sigmah = 15 MPa, \\sigmav = 25 MPa, \\sigmaH = 40 MPa). Drilling of a 20 mm dia. vertical hole created a long fracture-like thin tabular breakout along the \\sigmah springline and perpendicular to \\sigmaH direction. SEM analysis of the zones ahead of the breakout tips revealed narrow bands of presumed debonded intact grains interspersed with grain fragments. We infer that the fragments were formed from multiple splitting or crushing of compacted grains in the band of high compressive stress concentration developed along the \\sigmah springline. SEM images away from the breakout tip surroundings showed no such fragments. SEM study of the natural compaction band showed a similar arrangement of mainly intact grains surrounded by grain fragments. Using the Optimas optical software package, we found the percentage of pore area within the band ahead of the breakout tips to average 17%; outside of this zone it was 23%. In the natural compaction band pore area occupied 8.5% of the band; in the host rock adjacent to the compaction band it averaged 19%. These readings strongly suggest porosity reduction due to compaction in both cases. The close resemblance between the

  19. Roles of Autophagy Induced by Natural Compounds in Prostate Cancer

    PubMed Central

    Naponelli, V.; Bettuzzi, S.

    2015-01-01

    Autophagy is a homeostatic mechanism through which intracellular organelles and proteins are degraded and recycled in response to increased metabolic demand or stress. Autophagy dysfunction is often associated with many diseases, including cancer. Because of its role in tumorigenesis, autophagy can represent a new therapeutic target for cancer treatment. Prostate cancer (PCa) is one of the most common cancers in aged men. The evidence on alterations of autophagy related genes and/or protein levels in PCa cells suggests a potential implication of autophagy in PCa onset and progression. The use of natural compounds, characterized by low toxicity to normal tissue associated with specific anticancer effects at physiological levels in vivo, is receiving increasing attention for prevention and/or treatment of PCa. Understanding the mechanism of action of these compounds could be crucial for the development of new therapeutic or chemopreventive options. In this review we focus on the current evidence showing the capacity of natural compounds to exert their action through autophagy modulation in PCa cells. PMID:25821782

  20. Natural antioxidants as inhibitors of oxygen species induced mutagenicity.

    PubMed

    Minnunni, M; Wolleb, U; Mueller, O; Pfeifer, A; Aeschbacher, H U

    1992-10-01

    A ternary antioxidant vitamin mix consisting of ascorbic acid, alpha-tocopherol and lecithin as well as a rosemary extract with carnosic acid and carnosol as the two major active ingredients were shown to exhibit strong antimutagenic effects in Ames tester strain TA102. This strain has been shown to be highly sensitive to reactive oxygen species. Mutagenicity was induced by the generation of oxygen radicals by tert-butyl-hydroperoxide (tBOOH) or hydrogen peroxide (H2O2); therefore, the antimutagenic property of the above substances was attributed to their antioxidant properties. In the case of the vitamin mix, ascorbic acid was held responsible for this inhibitory property, whereas for the rosemary extract carnosic acid was identified as the antimutagenic agent. Since oxygen radicals are known to be involved in the multiprocess of carcinogenicity, it is concluded that these antioxidants might exhibit anticarcinogenic properties. PMID:1383702

  1. Contributions of biosurfactants to natural or induced bioremediation.

    PubMed

    Lawniczak, Lukasz; Marecik, Roman; Chrzanowski, Lukasz

    2013-03-01

    The number of studies dedicated to evaluating the influence of biosurfactants on bioremediation efficiency is constantly growing. Although significant progress regarding the explanation of mechanisms behind biosurfactant-induced effects could be observed, there are still many factors which are not sufficiently elucidated. This corresponds to the fact that although positive influence of biosurfactants is often reported, there are also numerous cases where no or negative effect was observed. This review summarizes the recent finding in the field of biosurfactant-amended bioremediation, focusing mainly on a critical approach towards potential limitations and causes of failure while investigating the effects of biosurfactants on the efficiency of biodegradation and phytoextraction processes. It also provides a summary of successive steps, which should be taken into consideration when designing biosurfactant-related treatment processes. PMID:23400445

  2. Natural and Induced Humoral Responses to MUC1

    PubMed Central

    von Mensdorff-Pouilly, Silvia; Moreno, Maria; Verheijen, René H. M.

    2011-01-01

    MUC1 is a membrane-tethered mucin expressed on the ductal cell surface of glandular epithelial cells. Loss of polarization, overexpression and aberrant glycosylation of MUC1 in mucosal inflammation and in adenocarcinomas induces humoral immune responses to the mucin. MUC1 IgG responses have been associated with a benefit in survival in patients with breast, lung, pancreatic, ovarian and gastric carcinomas. Antibodies bound to the mucin may curb tumor progression by restoring cell-cell interactions altered by tumor-associated MUC1, thus preventing metastatic dissemination, as well as counteracting the immune suppression exerted by the molecule. Furthermore, anti-MUC1 antibodies are capable of effecting tumor cell killing by antibody-dependent cell-mediated cytotoxicity. Although cytotoxic T cells are indispensable to achieve anti-tumor responses in advanced disease, abs to tumor-associated antigens are ideally suited to address minimal residual disease and may be sufficient to exert adequate immune surveillance in an adjuvant setting, destroying tumor cells as they arise or maintaining occult disease in an equilibrium state. Initial evaluation of MUC1 peptide/glycopeptide mono and polyvalent vaccines has shown them to be immunogenic and safe; anti-tumor responses are scarce. Progress in carbohydrate synthesis has yielded a number of sophisticated substrates that include MUC1 glycopeptide epitopes that are at present in preclinical testing. Adjuvant vaccination with MUC1 glycopeptide polyvalent vaccines that induce strong humoral responses may prevent recurrence of disease in patients with early stage carcinomas. Furthermore, prophylactic immunotherapy targeting MUC1 may be a strategy to strengthen immune surveillance and prevent disease in subjects at hereditary high risk of breast, ovarian and colon cancer. PMID:24212946

  3. Induced and Natural Seismicity: Earthquake Hazards and Risks in Ohio:

    NASA Astrophysics Data System (ADS)

    Besana-Ostman, G. M.; Worstall, R.; Tomastik, T.; Simmers, R.

    2013-12-01

    To adapt with increasing need to regulate all operations related to both the Utica and Marcellus shale play within the state, ODNR had recently strengthen its regulatory capability through implementation of stricter permit requirements, additional human resources and improved infrastructure. These ODNR's efforts on seismic risk reduction related to induced seismicity led to stricter regulations and many infrastructure changes related particularly to Class II wells. Permit requirement changes and more seismic monitoring stations were implemented together with additional injection data reporting from selected Class II well operators. Considering the possible risks related to seismic events in a region with relatively low seismicity, correlation between limited seismic data and injection volume information were undertaken. Interestingly, initial results showed some indications of both plugging and fracturing episodes. The real-time data transmission from seismic stations and availability of injection volume data enabled ODNR to interact with operators and manage wells dynamically. Furthermore, initial geomorphic and structural analyses indicated possible active faults in the northern and western portion of the state oriented NE-SW. The newly-mapped structures imply possible relatively bigger earthquakes in the region and consequently higher seismic risks. With the above-mentioned recent changes, ODNR have made critical improvement of its principal regulatory role in the state for oil and gas operations but also an important contribution to the state's seismic risk reduction endeavors. Close collaboration with other government agencies and the public, and working together with the well operators enhanced ODNR's capability to build a safety culture and achieve further public and industry participation towards a safer environment. Keywords: Induced seismicity, injection wells, seismic risks

  4. Thermal annealing-induced electric dipole relaxation in natural alexandrite

    NASA Astrophysics Data System (ADS)

    Scalvi, Rosa M. Fernandes; Li, Maximo Siu; Scalvi, Luis V. A.

    2005-02-01

    Electrical properties of natural alexandrite (BeAl2O4:Cr3+) are investigated by the thermally stimulated depolarization current (TSDC) technique. Samples are submitted to consecutive annealing processes and TSDC is carried out after each annealing, yielding bands with different parameters. These bands are fitted by a continuous distribution of relaxation parameters: activation energy and pre-exponential factor of the Arrhenius equation. It has been observed that annealing influences the dipole relaxation behavior, since it promotes a modification of Fe3+ and Cr3+ impurity distributions on sites of distinct symmetry: Al1 and Al2. In order to have a reference for comparison, TSDC is also carried out on a synthetic alexandrite sample, where the only impurity present is Cr3+ ion.

  5. Surface restoration induced by lubricant additive of natural minerals

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Gu, Jialin; Kang, Feiyu; Kong, Xianqing; Mo, Wei

    2007-07-01

    The effect of a new-fashioned lubricant additive is studied. The additive is prepared out of natural minerals containing flaky silicate, schungite and some other catalyzers. Applications of the additive obviously improve the surface mechanics properties of steel-steel friction pairs, and the nanohardness and the modulus of the friction surface are increased by 67 and 90%, respectively. The friction surface is especially examined with the high resolution transmission electron microscope (HRTEM), and an amorphous restoration film mostly made up of C with some Si or Si-O amorphous structure doped was found. Considering all research results about the restoration film, this study suggests the film is a sort of diamond-like carbon film (DLC film).

  6. Natural heme oxygenase-1 inducers in hepatobiliary function

    PubMed Central

    Volti, Giovanni Li; Sacerdoti, David; Giacomo, Claudia Di; Barcellona, Maria Luisa; Scacco, Antonio; Murabito, Paolo; Biondi, Antonio; Basile, Francesco; Gazzolo, Diego; Abella, Raul; Frigiola, Alessandro; Galvano, Fabio

    2008-01-01

    Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defences and modulate the cellular redox state. Changes in the cellular redox state may have wide-ranging consequences for cellular growth and differentiation. The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. However, in recent years a possible novel aspect in the mode of action of these compounds has been suggested; that is, the ultimate stimulation of the heme oxygenase-1 (HO-1) pathway is likely to account for the established and powerful antioxidant/anti-inflammatory properties of these polyphenols. The products of the HO-catalyzed reaction, particularly carbon monoxide (CO) and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to protection against liver damage in various experimental models. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect the liver against various stressors in several pathological conditions. PMID:18985801

  7. On natural metamorphosis inducers of the cnidarians Hydractinia echinata (Hydrozoa) and Aurelia aurita (Scyphozoa)

    NASA Astrophysics Data System (ADS)

    Kroiher, M.; Berking, S.

    1999-11-01

    Hydractinia echinata and Aurelia aurita produce motile larvae which undergo metamorphosis to sessile polyps when induced by external cues. The polyps are found at restricted sites, A. aurita predominantly on rocks close to the shore, H. echinata on shells inhabited by hermit crabs. It has been argued that the differential distribution of the polyps in their natural environment largely reflects the distribution of the natural metamorphosis-inducing cues. In the case of H. echinata, bacteria of the genus Alteromonas were argued to meet these conditions. We found that almost all substrates collected in the littoral to induce metamorphosis in H. echinata, and several bacterial strains isolated from the sea, including the common E. coli, induce metamorphosis efficiently. In A. aurita metamorphosis may be induced by the water-air interface, whereby metamorphosis precedes (final) settlement.

  8. Natural and induced B-1 cell immunity to infections raises questions of nature versus nurture.

    PubMed

    Baumgarth, Nicole; Waffarn, Elizabeth E; Nguyen, Trang T T

    2015-12-01

    Mouse B-1 cells are not only major producers of steady-state natural antibodies but also rapid responders to infections and inflammation. These discrete functions may be the outcomes of distinct environmental or developmental triggers that drive B-1 cells toward IgM production or an effector cell fate. Alternatively, distinct B-1 cell subsets may exist, which differ in their functional plasticity. In this paper, we summarize existing data suggesting that B-1 cells form a heterogeneous group of cells with distinct developmental requirements and nonoverlapping functions. Most spleen B-1 cells differ in development from that of bone marrow and peritoneal cavity B-1 cells, in that they develop in the absence of natural IgM. Functional heterogeneity is revealed by findings that B-1 cells in the bone marrow and spleen, but not the peritoneal cavity, generate natural serum IgM, while the latter are rapid responders to inflammatory and infectious insults, resulting in their relocation to secondary lymphoid tissues. A clearer understanding of the developmental and functional differences within the B-1 cell pool may reveal how they might be harnessed for prophylaxis or therapy. PMID:26060895

  9. The stochastic nature of growth of laser-induced damage

    NASA Astrophysics Data System (ADS)

    Carr, C. W.; Cross, David A.; Liao, Zhi M.; Norton, Mary A.; Negres, Raluca A.

    2015-07-01

    Laser fluence and operational tempo of ICF systems operating in the UV are typically limited by the growth of laser- induced damage on their final optics (primarily silica optics). In the early 2000 time frame, studies of laser damage growth with relevant large area beams revealed that for some laser conditions damage sites located on the exit surface of a fused silica optic grew following an exponential growth rule: D(n) = D0 exp (n α(φ)), where D is final site diameter, D0 is the initial diameter of the site, φ is the laser fluence, α(φ) is the growth coefficient, and n is the number of exposures. In general α is a linear function of φ, with a threshold of φTH. In recent years, it has been found that that growth behavior is actually considerably more complex. For example, it was found that α is not a constant for a given fluence but follows a probability distribution with a mean equal to α(φ). This is complicated by observations that these distributions are actually functions of the pulse shape, damage site size, and initial morphology of damage initiation. In addition, there is not a fixed fluence threshold for damage sites growth, which is better described by a probability of growth which depends on site size, morphology and laser fluence. Here will review these findings and discuss implications for the operation of large laser systems.

  10. Local nature of impurity induced spin-orbit torques

    NASA Astrophysics Data System (ADS)

    Nikolaev, Sergey; Kalitsov, Alan; Chshiev, Mairbec; Mryasov, Oleg

    Spin-orbit torques are of a great interest due to their potential applications for spin electronics. Generally, it originates from strong spin orbit coupling of heavy 4d/5d elements and its mechanism is usually attributed either to the Spin Hall effect or Rashba spin-orbit coupling. We have developed a quantum-mechanical approach based on the non-equilibrium Green's function formalism and tight binding Hamiltonian model to study spin-orbit torques and extended our theory for the case of extrinsic spin-orbit coupling induced by impurities. For the sake of simplicity, we consider a magnetic material on a two dimensional lattice with a single non-magnetic impurity. However, our model can be easily extended for three dimensional layered heterostructures. Based on our calculations, we present the detailed analysis of the origin of local spin-orbit torques and persistent charge currents around the impurity, that give rise to spin-orbit torques even in equilibrium and explain the existence of anisotropy.

  11. Nature of Pressure-induced Insulating States in Simple Metals

    NASA Astrophysics Data System (ADS)

    Naumov, Ivan; Hemley, Russell

    As experimentally established, all the alkali metals and heavy alkaline earth metals (Ca, Sr and Ba) become progressively less conductive on compression, at least up to some critical limit over a broad pressure range. Of these metals, Li and Na clearly undergo pressure-induced metal-insulator transitions, which may also be called reverse Mott transitions. Here, using group theory arguments and first-principles calculations, we show that such transitions can be understood in terms of band representations introduced by Zak. The valence bands in the insulating states are described by simple and composite band representations constructed from localized Wannier functions centered on points unoccupied by atoms. The character of the Wannier functions is closely related to the degree of s-p(-d) hybridization and reflects multi-center chemical bonding in these insulating states. The conditions under which an insulating state is allowed for structures having an integer number of atoms per primitive unit cell as well as re-entrant (i.e., metal-insulator-metal) transition sequences are detailed, resulting in predictions of semimetallic phases with flat surface states. The general principles developed are tested and applied to the alkali and alkaline earth metals, including elements where high-pressure insulating phases have been identified or reported (e.g., Li, Na, and Ca). This research was supported by EFree, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award DESC0001057.

  12. Natural Sesquiterpene Lactones Induce Oxidative Stress in Leishmania mexicana

    PubMed Central

    Barrera, Patricia; Sülsen, Valeria P.; Lozano, Esteban; Rivera, Mónica; Beer, María Florencia; Tonn, Carlos; Martino, Virginia S.; Sosa, Miguel A.

    2013-01-01

    Leishmaniasis is a worldwide parasitic disease, caused by monoflagellate parasites of the genus Leishmania. In the search for more effective agents against these parasites, the identification of molecular targets has been attempted to ensure the efficiency of drugs and to avoid collateral damages on the host's cells. In this work, we have investigated some of the mechanisms of action of a group of natural sesquiterpene lactones that are effective against Leishmania mexicana mexicana promastigotes. We first observed that the antiproliferative effect of mexicanin I (Mxc), dehydroleucodine (DhL), psilostachyin (Psi), and, at lesser extent, psilostachyin C (Psi C) is blocked by 1.5 mM reduced glutathione. The reducing agent was also able to reverse the early effect of the compounds, suggesting that lactones may react with intracellular sulfhydryl groups. Moreover, we have shown that all the sesquiterpene lactones, except Psi C, significantly decreased the endogenous concentration of glutathione within the parasite. Consistent with these findings, the active sesquiterpene lactones increased between 2.7 and 5.4 times the generation of ROS by parasites. These results indicate that the induction of oxidative stress is at least one of the mechanisms of action of DhL, Mxc, and Psi on parasites while Psi C would act by another mechanism. PMID:23861697

  13. Dusty plasma cavities: Probe-induced and natural

    NASA Astrophysics Data System (ADS)

    Harris, B. J.; Matthews, L. S.; Hyde, T. W.

    2015-06-01

    A comprehensive exploration of regional dust evacuation in complex plasma crystals is presented. Voids created in three-dimensional crystals on the International Space Station have provided a rich foundation for experiments, but cavities in dust crystals formed in ground-based experiments have not received as much attention. Inside a modified Gaseous Electronics Conference rf cell, a powered vertical probe was used to clear the central area of a dust crystal, producing a cavity with high cylindrical symmetry. Cavities generated by three mechanisms are examined. First, repulsion of micrometer-sized particles by a negatively charged probe is investigated. A model of this effect developed for a dc plasma is modified and applied to explain experimental data in rf plasma. Second, the formation of natural cavities is surveyed; a radial ion drag proposed to occur due to a curved sheath is considered in conjunction with thermophoresis and a flattened confinement potential above the center of the electrode. Finally, cavity formation upon increasing the probe potential above the plasma floating potential is justified by a combination of ion drag and sheath edge modification. The cavities produced by these methods appear similar, but each is shown to be facilitated by fundamentally different processes.

  14. Dusty plasma cavities: Probe-induced and natural.

    PubMed

    Harris, B J; Matthews, L S; Hyde, T W

    2015-06-01

    A comprehensive exploration of regional dust evacuation in complex plasma crystals is presented. Voids created in three-dimensional crystals on the International Space Station have provided a rich foundation for experiments, but cavities in dust crystals formed in ground-based experiments have not received as much attention. Inside a modified Gaseous Electronics Conference rf cell, a powered vertical probe was used to clear the central area of a dust crystal, producing a cavity with high cylindrical symmetry. Cavities generated by three mechanisms are examined. First, repulsion of micrometer-sized particles by a negatively charged probe is investigated. A model of this effect developed for a dc plasma is modified and applied to explain experimental data in rf plasma. Second, the formation of natural cavities is surveyed; a radial ion drag proposed to occur due to a curved sheath is considered in conjunction with thermophoresis and a flattened confinement potential above the center of the electrode. Finally, cavity formation upon increasing the probe potential above the plasma floating potential is justified by a combination of ion drag and sheath edge modification. The cavities produced by these methods appear similar, but each is shown to be facilitated by fundamentally different processes. PMID:26172806

  15. Rainfall Induced Natural Disaster in Central America, a challenge for Regional Risk Management

    NASA Astrophysics Data System (ADS)

    Estuardo Guinea Barrientos, Héctor; Swain, Ashok

    2013-04-01

    Rainfall induced natural disasters rank first among all natural disasters in Central America. According to the records of the EM-DAT international database, 248 out of 486 disasters registered in Central America were disasters triggered by rainfall invents, in countries like Belize and Honduras, rainfall-induced natural disasters, mainly floods and landslides, account for more than 90% of the total number of casualties as well as the economic damage of all the disasters. Due to the natural conditions of the Central American Isthmus, precipitation events often struck more than one country at the time, for example Hurricane Mitch in 1998 affected the entire Central American region causing more than 18,000 casualties. In this context, the Central America countries have been working on joint programs and policies aiming transboundary cooperation and management of natural disasters, a clear example of this effort is CEPREDENAC which is the intergovernmental body with the mandate of promoting activities, projects and programs towards reduction of the risks to disasters in order to avoid loss of life and economic assets in the Central America, however, transnational management face several challenges that fall mostly in the political, economical and technical areas. In this paper we described and analyzed the rainfall induced natural disasters, their impacts and the inherent management challenges in the Central American context. Key words: Central America, Natural Disasters, Risk Management, International Cooperation

  16. Natural cell-mediated cytotoxicity against Candida albicans induced by cyclophosphamide: nature of the in vitro cytotoxic effector.

    PubMed Central

    Baccarini, M; Bistoni, F; Puccetti, P; Garaci, E

    1983-01-01

    We have recently reported the in vivo modulation of resistance to experimental Candida albicans infection by cyclophosphamide (150 mg/kg intraperitoneally) in mice and have shown that increased resistance to the microbial challenge occurs 12 to 21 days after treatment with the drug (Bistoni et al., Infect. Immun. 40: 46-55, 1983). The event is accompanied by the appearance of a highly candidacidal cell population in the spleen and the activation of a subpopulation of natural cytotoxic effectors reactive in vitro against YAC-1 tumor cells. We now provide evidence that these anti-YAC-1 cytotoxic effectors are clearly distinct from the cyclophosphamide-induced candidacidal effectors, which seem to belong to a macrophage-monocyte lineage. The enhanced cytotoxic activity induced by cyclophosphamide was not restricted to C. albicans but was also exerted against a panel of Candida strains. PMID:6352489

  17. Bistability of the naturally induced lactose utilization system of Escherichia coli

    NASA Astrophysics Data System (ADS)

    Stajic, Jelena; Wall, Michael

    2006-03-01

    In the absence of the preferred sugar glucose, lactose utilization machinery in the bacterium E. coli is activated. The genetic circuit responsible for this response, lac operon, has been observed to exhibit bistability when induced by an artificial inducer, TMG. Here we investigate conditions under which bistability might be observed in response to lactose. The aim of our study is to establish whether the natural system exhibits bistability, as is often assumed despite the lack of experimental support.

  18. Dendritic Cells in the Periphery Control Antigen-Specific Natural and Induced Regulatory T Cells

    PubMed Central

    Yamazaki, Sayuri; Morita, Akimichi

    2013-01-01

    Dendritic cells (DCs) are specialized antigen-presenting cells that regulate both immunity and tolerance. DCs in the periphery play a key role in expanding naturally occurring Foxp3+ CD25+ CD4+ regulatory T cells (Natural T-regs) and inducing Foxp3 expression (Induced T-regs) in Foxp3− CD4+ T cells. DCs are phenotypically and functionally heterogeneous, and further classified into several subsets depending on distinct marker expression and their location. Recent findings indicate the presence of specialized DC subsets that act to expand Natural T-regs or induce Foxp3+ T-regs from Foxp3− CD4+ T cells. For example, two major subsets of DCs in lymphoid organs act differentially in inducing Foxp3+ T-regs from Foxp3− cells or expanding Natural T-regs with model-antigen delivery by anti-DC subset monoclonal antibodies in vivo. Furthermore, DCs expressing CD103 in the intestine induce Foxp3+ T-regs from Foxp3− CD4+ T cells with endogenous TGF-β and retinoic acid. In addition, antigen-presenting DCs have a capacity to generate Foxp3+ T-regs in the oral cavity where many antigens and commensals exist, similar to intestine and skin. In skin and skin-draining lymph nodes, at least six DC subsets have been identified, suggesting a complex DC-T-reg network. Here, we will review the specific activity of DCs in expanding Natural T-regs and inducing Foxp3+ T-regs from Foxp3− precursors, and further discuss the critical function of DCs in maintaining tolerance at various locations including skin and oral cavity. PMID:23801989

  19. Dealing naturally with stumbling blocks on highways and byways of TRAIL induced signaling.

    PubMed

    Rana, Aamir; Attar, Rukset; Qureshi, Muhammad Zahid; Gasparri, Maria Luisa; Donato, Violante Di; Ali, Ghulam Muhammad; Farooqi, Ammad Ahmad

    2014-01-01

    In-depth analysis of how TRAIL signals through death receptors to induce apoptosis in cancer cells using high throughput technologies has added new layers of knowledge. However, the wealth of information has also highlighted the fact that TRAIL induced apoptosis may be impaired as evidenced by experimental findings obtained from TRAIL resistant cancer cell lines. Overwhelmingly, increasing understanding of TRAIL mediated apoptosis has helped in identifying synthetic and natural compounds which can restore TRAIL induced apoptosis via functionalization of either extrinsic or intrinsic pathways. Increasingly it is being realized that biologically active phytochemicals modulate TRAIL induced apoptosis, as evidenced by cell-based studies. In this review we have attempted to provide an overview of how different phytonutrients have shown efficacy in restoring apoptosis in TRAIL resistant cancer cells. We partition this review into how the TRAIL mediated signaling landscape has broadened over the years and how TRAIL induced signaling machinery crosstalks with autophagic protein networks. Subsequently, we provide a generalized view of considerable biological activity of coumarins against a wide range of cancer cell lines and how coumarins (psoralidin and esculetin) isolated from natural sources have improved TRAIL induced apoptosis in resistant cancer cells. We summarize recent updates on piperlongumine, phenethyl isothiocyanate and luteolin induced activation of TRAIL mediated apoptosis. The data obtained from pre-clinical studies will be helpful in translation of information from benchtop to the bedside. PMID:25338981

  20. Natural Products for Management of Oral Mucositis Induced by Radiotherapy and Chemotherapy.

    PubMed

    Aghamohamamdi, Azar; Hosseinimehr, Seyed Jalal

    2016-03-01

    Oral mucositis is a common side effect of systemic chemotherapy and radiotherapy of head and neck in patients with cancer. Severe oral mucositis is painful and affects oral functions, including intake of food and medications and speech. Prevention of oral mucositis affects the life quality of patients. Recent studies have been focused on natural products to improve or reduce this complication. Many clinical trials have been performed to assess natural products for treatment of mucositis and their results are promising. The authors reviewed the evidence for natural products in the prevention and treatment of oral mucositis induced by radiation therapy and chemotherapy. PMID:26306626

  1. Promoting natural killer cell functions by recombinant immunoligands mimicking an induced self phenotype

    PubMed Central

    Kellner, Christian; Gramatzki, Martin; Peipp, Matthias

    2013-01-01

    Immunoligands for stimulatory natural killer (NK)-cell receptors can be targeted to the surface of malignant cells by fusing them to antibody fragments. Mimicking an “induced-self” phenotype, such recombinant immunoligands signal danger, trigger NK-cell cytotoxicity and synergistically enhance antibody-dependent cellular cytotoxicity. These findings may be translated into novel immunotherapeutic approaches against cancer. PMID:23894708

  2. New Madrid Seismic Zone: a test case for naturally induced seismicity

    SciTech Connect

    Nava, S.J.

    1983-09-01

    Induced seismicity caused by man-made events, such as the filling of reservoirs has been well documented. In contrast, naturally induced seismicity has received little attention. It has been shown that a fluctuation of as little as several bars can trigger reservoir induced earthquakes. Naturally occurring phenomena generate similar fluctuations and could trigger earthquakes where the faults in ambient stress field are suitably oriented and close to failure. The New Madrid Seismic Zone (NMSZ) presents an ideal test case for the study of naturally induced seismicity. The ideal data set for a study of triggering effects must contain a statistically significant number of events, a constant accumulated strain, and a limited focal region. New Madrid earthquakes are well documented from 1974 to the present, down to a magnitude approx. 1.8. They lie in a distinct fault pattern and occur as a reaction to the regional stress regime. A statistical correlation was made between the earthquakes and a variety of different types of loads, to see if New Madrid seismicity could be triggered by natural fluctuations. The types of triggers investigated ranged from solid earth tides to variations in barometric pressure, rainfall, and stages of the Mississippi River. This analysis becomes complex because each factor investigated creates individual stresses, as well as having imbedded in it a reaction to other factors.

  3. Phenolic profile of Asturian (Spain) natural cider.

    PubMed

    Rodríguez Madrera, Roberto; Picinelli Lobo, Anna; Suárez Valles, Belén

    2006-01-11

    The polyphenolic composition of natural ciders from the Asturian community (Spain), during 2 consecutive years, was analyzed by RP-HPLC and the photodiode-array detection system, without previous extraction (direct injection). A total of 16 phenolic compounds (catechol, tyrosol, protocatechuic acid, hydrocaffeic acid, chlorogenic acid, hydrocoumaric acid, ferulic acid, (-)-epicatechin, (+)-catechin, procyanidins B2 and B5, phloretin-2'-xyloglucoside, phloridzin, hyperin, avicularin, and quercitrin) were identified and quantified. A fourth quercetin derivative, one dihydrochalcone-related compound, two unknown procyanidins, three hydroxycinnamic derivatives, and two unknown compounds were also found. Among the low-molecular-mass polyphenols analyzed, hydrocaffeic acid was the most abundant compound, representing more than 80% of the total polyphenolic acids. Procyanidins were the most important family among the flavonoid compounds. Discriminant analysis was allowed to correctly classify more than 93% of the ciders, according to the harvest year; the most discriminant variables were an unknown procyanidin and quercitrin. PMID:16390187

  4. Discriminating induced seismicity from natural earthquakes using moment tensors and source spectra

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Eaton, David W.; Li, Ge; Liu, Yajing; Harrington, Rebecca M.

    2016-02-01

    Earthquake source mechanisms and spectra can provide important clues to aid in discriminating between natural and induced events. In this study, we calculate moment tensors and stress drop values for eight recent induced earthquakes in the Western Canadian Sedimentary Basin with magnitudes between 3.2 and 4.4, as well as a nearby magnitude 5.3 event that is interpreted as a natural earthquake. We calculate full moment tensor solutions by performing a waveform-fitting procedure based on a 1-D transversely isotropic velocity model. In addition to a dominant double-couple (DC) signature that is common to nearly all events, most induced events exhibit significant non-double-couple components. A parameter sensitivity analysis indicates that spurious non-DC components are negligible if the signal to noise ratio (SNR) exceeds 10 and if the 1-D model differs from the true velocity structure by less than 5%. Estimated focal depths of induced events are significantly shallower than the typical range of focal depths for intraplate earthquakes in the Canadian Shield. Stress drops of the eight induced events were estimated using a generalized spectral-fitting method and fall within the typical range of 2 to 90 MPa for tectonic earthquakes. Elastic moduli changes due to the brittle damage production at the source, presence of multiple intersecting fractures, dilatant jogs created at the overlapping areas of multiple fractures, or non-planar pre-existing faults may explain the non-DC components for induced events.

  5. Meiotic chromosome pairing behaviour of natural tetraploids and induced autotetraploids of Actinidia chinensis.

    PubMed

    Wu, Jin-Hu; Datson, Paul M; Manako, Kelvina I; Murray, Brian G

    2014-03-01

    Non-preferential chromosome pairing was identified in tetraploid Actinidia chinensis and a higher mean multivalent frequency in pollen mother cells was found in colchine-induced tetraploids of A. chinensis compared with naturally occurring tetraploids. Diploid and tetraploid Actinidia chinensis are used for the development of kiwifruit cultivars. Diploid germplasm can be exploited in a tetraploid breeding programme via unreduced (2n) gametes and chemical-induced chromosome doubling of diploid cultivars and selections. Meiotic chromosome behaviour in diploid A. chinensis 'Hort16A' and colchicine-induced tetraploids from 'Hort16A' was analysed and compared with that in a diploid male and tetraploid males of A. chinensis raised from seeds sourced from the wild in China. Both naturally occurring and induced tetraploids formed multivalents, but colchicine-induced tetraploids showed a higher mean multivalent frequency in the pollen mother cells. Lagging chromosomes at anaphase I and II were observed at low frequencies in the colchicine-induced tetraploids. To investigate whether preferential or non-preferential chromosome pairing occurs in tetraploid A. chinensis, the inheritance of microsatellite alleles was analysed in the tetraploid progeny of crosses between A. chinensis (4x) and A. arguta (4x). The frequencies of inherited microsatellite allelic combinations in the hybrids suggested that non-preferential chromosome pairing had occurred in the tetraploid A. chinensis parent. PMID:24306317

  6. Natural or Induced: Identifying Natural and Induced Swarms from Pre-production and Co-production Microseismic Catalogs at the Coso Geothermal Field

    USGS Publications Warehouse

    Schoenball, Martin; Kaven, Joern; Glen, Jonathan M.; Davatzes, Nicholas C.

    2015-01-01

    Increased levels of seismicity coinciding with injection of reservoir fluids have prompted interest in methods to distinguish induced from natural seismicity. Discrimination between induced and natural seismicity is especially difficult in areas that have high levels of natural seismicity, such as the geothermal fields at the Salton Sea and Coso, both in California. Both areas show swarm-like sequences that could be related to natural, deep fluid migration as part of the natural hydrothermal system. Therefore, swarms often have spatio-temporal patterns that resemble fluid-induced seismicity, and might possibly share other characteristics. The Coso Geothermal Field and its surroundings is one of the most seismically active areas in California with a large proportion of its activity occurring as seismic swarms. Here we analyze clustered seismicity in and surrounding the currently produced reservoir comparatively for pre-production and co-production periods. We perform a cluster analysis, based on the inter-event distance in a space-time-energy domain to identify notable earthquake sequences. For each event j, the closest previous event i is identified and their relationship categorized. If this nearest neighbor’s distance is below a threshold based on the local minimum of the bimodal distribution of nearest neighbor distances, then the event j is included in the cluster as a child to this parent event i. If it is above the threshold, event j begins a new cluster. This process identifies subsets of events whose nearest neighbor distances and relative timing qualify as a cluster as well as a characterizing the parent-child relationships among events in the cluster. We apply this method to three different catalogs: (1) a two-year microseismic survey of the Coso geothermal area that was acquired before exploration drilling in the area began; (2) the HYS_catalog_2013 that contains 52,000 double-difference relocated events and covers the years 1981 to 2013; and (3) a

  7. Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

    PubMed Central

    Mohd Sairazi, Nur Shafika; Sirajudeen, K. N. S.; Asari, Mohd Asnizam; Muzaimi, Mustapha; Mummedy, Swamy; Sulaiman, Siti Amrah

    2015-01-01

    Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS). In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA). KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration. PMID:26793262

  8. Natural sunlight NO(3)(-)/NO(2)(-)-induced photo-degradation of phenylurea herbicides in water.

    PubMed

    Shankar, M V; Nélieu, S; Kerhoas, L; Einhorn, J

    2008-04-01

    The nitrate-induced photodegradation of phenylureas in water was demonstrated to occur efficiently using natural sunlight irradiation. The kinetics of disappearance was found to be dependent on the inducer and substrate concentrations, the phenylurea structure and the origin and composition of the aqueous matrix including the presence of nitrite. The measured effects under sunlight were of the same order of those measured previously in the lab using our solar light simulated system. However, by-product distribution might differ substantially particularly considering the nitration pathway. PMID:18262593

  9. Connecting model species to nature: predator-induced long-term sensitization in Aplysia californica.

    PubMed

    Mason, Maria J; Watkins, Amanda J; Wakabayashi, Jordann; Buechler, Jennifer; Pepino, Christine; Brown, Michelle; Wright, William G

    2014-08-01

    Previous research on sensitization in Aplysia was based entirely on unnatural noxious stimuli, usually electric shock, until our laboratory found that a natural noxious stimulus, a single sublethal lobster attack, causes short-term sensitization. We here extend that finding by demonstrating that multiple lobster attacks induce long-term sensitization (≥24 h) as well as similar, although not identical, neuronal correlates as observed after electric shock. Together these findings establish long- and short-term sensitization caused by sublethal predator attack as a natural equivalent to sensitization caused by artificial stimuli. PMID:25028394

  10. Connecting model species to nature: predator-induced long-term sensitization in Aplysia californica

    PubMed Central

    Mason, Maria J.; Watkins, Amanda J.; Wakabayashi, Jordann; Buechler, Jennifer; Pepino, Christine; Brown, Michelle

    2014-01-01

    Previous research on sensitization in Aplysia was based entirely on unnatural noxious stimuli, usually electric shock, until our laboratory found that a natural noxious stimulus, a single sublethal lobster attack, causes short-term sensitization. We here extend that finding by demonstrating that multiple lobster attacks induce long-term sensitization (≥24 h) as well as similar, although not identical, neuronal correlates as observed after electric shock. Together these findings establish long- and short-term sensitization caused by sublethal predator attack as a natural equivalent to sensitization caused by artificial stimuli. PMID:25028394

  11. A study of lesions induced in Seriola dumerili infected naturally with Streptococcus dysgalactiae.

    PubMed

    Hagiwara, H; Takano, R; Noguchi, M; Taniuchi, Y; Kawano, K; Narita, M; Yanai, T

    2011-01-01

    An outbreak of disease in Seriola dumerili occurred from August to October in 2007 and 2008. The fish developed lesions of the caudal peduncle, pectoral and/or dorsal fin and the heart. The lesions were characterized by moderate to severe infarction with areas of microabscessation and multifocal granulomatous inflammation associated with the presence of Streptococcus dysgalactiae antigen. This is the first report to describe the immunohistology of the lesions induced in S. dumerili following natural infection with S. dysgalactiae. PMID:21453928

  12. The antitumor natural compound falcarindiol promotes cancer cell death by inducing endoplasmic reticulum stress

    PubMed Central

    Jin, H R; Zhao, J; Zhang, Z; Liao, Y; Wang, C-Z; Huang, W-H; Li, S-P; He, T-C; Yuan, C-S; Du, W

    2012-01-01

    Falcarindiol (FAD) is a natural polyyne with various beneficial biological activities. We show here that FAD preferentially kills colon cancer cells but not normal colon epithelial cells. Furthermore, FAD inhibits tumor growth in a xenograft tumor model and exhibits strong synergistic killing of cancer cells with 5-fluorouracil, an approved cancer chemotherapeutic drug. We demonstrate that FAD-induced cell death is mediated by induction of endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). Decreasing the level of ER stress, either by overexpressing the ER chaperone protein glucose-regulated protein 78 (GRP78) or by knockout of components of the UPR pathway, reduces FAD-induced apoptosis. In contrast, increasing the level of ER stress by knocking down GRP78 potentiates FAD-induced apoptosis. Finally, FAD-induced ER stress and apoptosis is correlated with the accumulation of ubiquitinated proteins, suggesting that FAD functions at least in part by interfering with proteasome function, leading to the accumulation of unfolded protein and induction of ER stress. Consistent with this, inhibition of protein synthesis by cycloheximide significantly decreases the accumulation of ubiquitinated proteins and blocks FAD-induced ER stress and cell death. Taken together, our study shows that FAD is a potential new anticancer agent that exerts its activity through inducing ER stress and apoptosis. PMID:22914324

  13. Natural phenylpropanoids protect endothelial cells against oxidized LDL-induced cytotoxicity.

    PubMed

    Martin-Nizard, Françoise; Sahpaz, Sevser; Furman, Christophe; Fruchart, Jean-Charles; Duriez, Patrick; Bailleul, François

    2003-03-01

    There is increasing evidence that oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis of atherosclerosis and it has been reported that polyphenols inhibit LDL peroxidation and atherosclerosis. Minimally oxidized LDL (mOx-LDL) induce cytotoxicity in cultured bovine aortic endothelial cells (BAEC). The goal of this study was to test the protective effect of five natural polyphenols isolated from the aerial parts of Marrubium vulgare L. against mOx-LDL-induced cytotoxicity in BAEC. Four phenylpropanoid glycosides (acteoside 1, forsythoside B 2, arenarioside 3, ballotetroside 4) and one non-glycosidic derivative (caffeoyl-l-malic acid 5) were tested. These compounds inhibited both copper (Cu 2+)- and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced in vitro LDL oxidation and preserved the morphological aspects of BAEC during their incubation with mOx-LDL. Furthermore, they reduced the accumulation of aldehydes in the cultured medium during the incubation of BAEC with mOx-LDL and prevented cellular LDH leakage during this period. These data suggest that natural phenylpropanoids inhibit mOx-LDL-induced cellular toxicity and that inhibition of lipid peroxidation could be a key mechanism in the cytoprotective effect of these molecules. PMID:12677522

  14. Recent Advances in Remote Sensing of Natural Hazards-Induced Atmospheric and Ionospheric Perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Y. M.; Komjathy, A.; Meng, X.; Verkhoglyadova, O. P.; Langley, R. B.; Mannucci, A. J.

    2015-12-01

    Traveling ionospheric disturbances (TIDs) induced by acoustic-gravity waves in the neutral atmosphere have significant impact on trans-ionospheric radio waves such as Global Navigation Satellite System (GNSS, including Global Position System (GPS)) measurements. Natural hazards and solid Earth events, such as earthquakes, tsunamis and volcanic eruptions are actual sources that may trigger acoustic and gravity waves resulting in traveling ionospheric disturbances (TIDs) in the upper atmosphere. Trans-ionospheric radio wave measurements sense the total electron content (TEC) along the signal propagation path. In this research, we introduce a novel GPS-based detection and estimation technique for remote sensing of atmospheric wave-induced TIDs including space weather phenomena induced by major natural hazard events, using TEC time series collected from worldwide ground-based dual-frequency GNSS (including GPS) receiver networks. We demonstrate the ability of using ground- and space-based dual-frequency GPS measurements to detect and monitor tsunami wave propagation from the 2011 Tohoku-Oki earthquake and tsunami. Major wave trains with different propagation speeds and wavelengths were identified through analysis of the GPS remote sensing observations. Dominant physical characteristics of atmospheric wave-induced TIDs are found to be associated with specific tsunami propagations and oceanic Rayleigh waves. In this research, we compared GPS-based observations, corresponding model simulations and tsunami wave propagation. Results are shown to lead to a better understanding of the tsunami-induced ionosphere responses. Based on current distribution of Plate Boundary Observatory GPS stations, the results indicate that tsunami-induced TIDs may be detected about 60 minutes prior to tsunamis arriving at the U.S. west coast. It is expected that this GNSS-based technology will become an integral part of future early-warning systems.

  15. Differentiating induced and natural seismicity using space-time-magnitude statistics applied to the Coso Geothermal field

    USGS Publications Warehouse

    Schoenball, Martin; Davatzes, Nicholas C.; Glen, Jonathan M.

    2015-01-01

    A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the preproduction and coproduction periods from 1981 to 2013, we analyze interevent times, spatial dimension, and frequency-size distributions for natural and induced earthquakes. Individually, these distributions are statistically indistinguishable. Determining the distribution of nearest neighbor distances in a combined space-time-magnitude metric, lets us identify clear differences between both kinds of seismicity. Compared to natural earthquakes, induced earthquakes feature a larger population of background seismicity and nearest neighbors at large magnitude rescaled times and small magnitude rescaled distances. Local stress perturbations induced by field operations appear to be strong enough to drive local faults through several seismic cycles and reactivate them after time periods on the order of a year.

  16. Analysis of the adverse reactions induced by natural product-derived drugs

    PubMed Central

    Zeng, Zhi-Ping; Jiang, Jian-Guo

    2010-01-01

    Compared with the therapeutic effects of established medicinal drugs, it is often considered that natural product-derived drugs are of a more benign nature in side-effects, which has made natural medicines become a popular form of therapy. Traditional Chinese medicine (TCM) is generally considered as being natural and harmless. TCM has been paid much more attention than before and widely used for the treatment nowadays. However, with the increasing cases of adverse drug reactions (ADRs), the ADRs induced by TCM are becoming more widely recognized. Some ADRs are sometimes even life-threatening. This article reviews literatures on ADRs induced by TCM which was published in the past 10 years. A total of 3122 cases including complete data are selected for the present analysis. From the data of the 3122 cases, statistics is carried out to the distribution of administration routes and time of the occurrence of ADRs, the prognosis of ADRs, sex and age factors, types and clinical symptoms of ADRs, and drugs involved in ADRs. In addition, occurrence and influencing factors of TCM-induced diseases are also analysed, which includes spices confusion, processing drugs improperly, toxic components, long-term medication, improper concerted application, interaction of TCM and Western medicine. It is concluded that the efficacy and toxicity of TCM, often using the compound prescription involving various plants and animals, resulted from a variety of chemical constituents, which lead to a comprehensive response in the human body. The ‘toxicity’ of TCM should be correctly recognized and reasonably utilized. PMID:20233209

  17. A Micro-Mechanically Based Continuum Model for Strain-Induced Crystallization in Natural Rubber

    NASA Astrophysics Data System (ADS)

    Mistry, Sunny Jigger

    Recent experimental results show that strain-induced crystallization can substantially improve the crack growth resistance of natural rubber. While this might suggest superior designs of tires or other industrial applications where elastomers are used, a more thorough understanding of the underlying physics of strain-induced crystallization in natural rubber has to be developed before any design process can be started. The objective of this work is to develop a computationally-accessible micro-mechanically based continuum model, which is able to predict the macroscopic behavior of strain crystallizing natural rubber. While several researchers have developed micro-mechanical models of partially crystallized polymer chains, their results mainly give qualitative agreement with experimental data due to a lack of good micro-macro transition theories or the lack of computational power. However, recent developments in multiscale modeling in polymers provide new tools to continue this early work. In this thesis, a new model is proposed to model strain-induced crystallization in natural rubber. To this end, a micro-mechanical model of a constrained partially crystallized polymer chain with an extended-chain crystal is derived and connected to the macroscopic level using the non-affine micro-sphere model. On the macroscopic level, a thermodynamically consistent framework for strain-crystallizing materials is developed, and a description of the crystallization kinetics is introduced. For that matter, an evolution law for crystallization based on the gradient of the macroscopic Helmholtz free energy function (chemical potential) in combination with a simple threshold function is used. A numerical implementation of the model is proposed and its predictive performance assessed using published data.

  18. Distinguishing induced seismicity from natural seismicity in Ohio: Demonstrating the utility of waveform template matching

    NASA Astrophysics Data System (ADS)

    Skoumal, Robert J.; Brudzinski, Michael R.; Currie, Brian S.

    2015-09-01

    This study investigated the utility of multistation waveform cross correlation to help discern induced seismicity. Template matching was applied to all Ohio earthquakes cataloged since the arrival of nearby EarthScope TA stations in late 2010. Earthquakes that were within 5 km of fluid injection activities in regions that lacked previously documented seismicity were found to be swarmy. Moreover, the larger number of events produced by template matching for these swarmy sequences made it easier to establish more detailed temporal and spatial relationships between the seismicity and fluid injection activities, which is typically required for an earthquake to be considered induced. Study results detected three previously documented induced sequences (Youngstown, Poland Township, and Harrison County) and provided evidence that suggests two additional cases of induced seismicity (Belmont/Guernsey County and Washington County). Evidence for these cases suggested that unusual swarm-like behaviors in regions that lack previously documented seismicity can be used to help distinguish induced seismicity, complementing the traditional identification of an anthropogenic source spatially and temporally correlated with the seismicity. In support of this finding, we identified 17 additional cataloged earthquakes in regions of previously documented seismicity and away from disposal wells or hydraulic fracturing that returned very few template matches. The lack of swarminess helps to indicate that these events are most likely naturally occurring.

  19. Natural Product Vibsanin A Induces Differentiation of Myeloid Leukemia Cells through PKC Activation.

    PubMed

    Yu, Zu-Yin; Xiao, He; Wang, Li-Mei; Shen, Xing; Jing, Yu; Wang, Lin; Sun, Wen-Feng; Zhang, Yan-Feng; Cui, Yu; Shan, Ya-Jun; Zhou, Wen-Bing; Xing, Shuang; Xiong, Guo-Lin; Liu, Xiao-Lan; Dong, Bo; Feng, Jian-Nan; Wang, Li-Sheng; Luo, Qing-Liang; Zhao, Qin-Shi; Cong, Yu-Wen

    2016-05-01

    All-trans retinoic acid (ATRA)-based cell differentiation therapy has been successful in treating acute promyelocytic leukemia, a unique subtype of acute myeloid leukemia (AML). However, other subtypes of AML display resistance to ATRA-based treatment. In this study, we screened natural, plant-derived vibsane-type diterpenoids for their ability to induce differentiation of myeloid leukemia cells, discovering that vibsanin A potently induced differentiation of AML cell lines and primary blasts. The differentiation-inducing activity of vibsanin A was mediated through direct interaction with and activation of protein kinase C (PKC). Consistent with these findings, pharmacological blockade of PKC activity suppressed vibsanin A-induced differentiation. Mechanistically, vibsanin A-mediated activation of PKC led to induction of the ERK pathway and decreased c-Myc expression. In mouse xenograft models of AML, vibsanin A administration prolonged host survival and inhibited PKC-mediated inflammatory responses correlated with promotion of skin tumors in mice. Collectively, our results offer a preclinical proof of concept for vibsanin A as a myeloid differentiation-inducing compound, with potential application as an antileukemic agent. Cancer Res; 76(9); 2698-709. ©2016 AACR. PMID:26984756

  20. Inter event times of fluid induced earthquakes suggest their Poisson nature

    NASA Astrophysics Data System (ADS)

    Langenbruch, C.; Dinske, C.; Shapiro, S. A.

    2011-11-01

    We analyze the inter event time distribution of fluid-injection-induced earthquakes for six catalogs collected at geothermal injection sites at Soultz-sous-Forêts and Basel. We find that the distribution of waiting times during phases of constant seismicity rate coincides with the exponential distribution of the homogeneous Poisson process (HPP). We analyze the waiting times for the complete event catalogs and find that, as for naturally occurring earthquakes, injection induced earthquakes are distributed according to a non homogeneous Poisson process in time. Moreover, the process of event occurrence in the injection volume domain is a HPP. These results indicate that fluid-injection-induced earthquakes are directly triggered by the loading induced by the fluid injection. We also consider the spatial distance between events and perform a nearest neighbor analysis in the time-space-magnitude domain. Our analysis including a comparison to a synthetic catalog created according to the ETAS model reveals no signs of causal relationships between events. Therefore, coupling effects between events are very weak. The Poisson model seems to be a very good approximation of fluid induced seismicity.

  1. Nitrate-induced photolysis in natural waters: Controls on concentrations of hydroxyl radical photo-intermediates by natural scavenging agents

    SciTech Connect

    Brezonik, P.L.; Fulkerson-Brekken, J.

    1998-10-01

    The importance of the principal natural scavenging agents for hydroxyl radicals ({sup {sm_bullet}}OH) was evaluated, and a general framework was developed to predict the significance of nitrate-induced, {sup {sm_bullet}}OH-mediated degradation of aquatic contaminants. Rate constants for *OH scavenging by dissolved organic matter (DOM) from five surface water sources were in a narrow range which is similar to previously reported values and suggests that the importance of DOM as a {sup {sm_bullet}}OH sink can be estimated simply from the dissolved organic carbon (DOC) concentration of a water. Scavenging of {sup {sm_bullet}}*OH by carbonate and bicarbonate is generally less important, but these ions can be the major cause of *OH scavenging in low DOC, high alkalinity waters. Use of the framework is illustrated by predicting levels of {sup {sm_bullet}}OH and half-lives of the corn herbicide acetochlor in waters ranging from pristine to highly influenced by agricultural activities.

  2. Induced and natural break sites in the chromosomes of Hawaiian Drosophila

    SciTech Connect

    Tonzetich, J.; Lyttle, T.W.; Carson, H.L.

    1988-03-01

    Gamma-irradiation of a laboratory strain of the Hawaiian species of Drosophila heteroneura yielded 310 breaks in the five major acrocentric polytene chromosomes. Their map positions conform to the Poisson distribution, unlike most of the 436 natural breaks mapped in 105 closely related species endemic to Hawaii. Genome element E is longer and has more induced breaks than the others. Both in Hawaiian and related species groups, this element shows increased polymorphism and fixation of naturally occurring inversions. The X chromosome (element A) also accumulates many natural breaks; the majority of the resulting aberrations become fixed rather than remain as polymorphisms. Although size may play a small role in initial break distribution, the major effects relative to the establishment of a rearrangement in natural populations are ascribed to the interaction of selection and drift. Nonconformance of the natural breaks to the Poisson distribution appears to be due to the tendency for breaks to accumulate both in the proximal euchromatic portion of each arm and in heterochromatic regions that are not replicated in the polytene chromosomes.

  3. Platelet Dynamics during Natural and Pharmacologically Induced Torpor and Forced Hypothermia

    PubMed Central

    de Vrij, Edwin L.; Vogelaar, Pieter C.; Goris, Maaike; Houwertjes, Martin C.; Herwig, Annika; Dugbartey, George J.; Boerema, Ate S.; Strijkstra, Arjen M.; Bouma, Hjalmar R.; Henning, Robert H.

    2014-01-01

    Hibernation is an energy-conserving behavior in winter characterized by two phases: torpor and arousal. During torpor, markedly reduced metabolic activity results in inactivity and decreased body temperature. Arousal periods intersperse the torpor bouts and feature increased metabolism and euthermic body temperature. Alterations in physiological parameters, such as suppression of hemostasis, are thought to allow hibernators to survive periods of torpor and arousal without organ injury. While the state of torpor is potentially procoagulant, due to low blood flow, increased viscosity, immobility, hypoxia, and low body temperature, organ injury due to thromboembolism is absent. To investigate platelet dynamics during hibernation, we measured platelet count and function during and after natural torpor, pharmacologically induced torpor and forced hypothermia. Splenectomies were performed to unravel potential storage sites of platelets during torpor. Here we show that decreasing body temperature drives thrombocytopenia during torpor in hamster with maintained functionality of circulating platelets. Interestingly, hamster platelets during torpor do not express P-selectin, but expression is induced by treatment with ADP. Platelet count rapidly restores during arousal and rewarming. Platelet dynamics in hibernation are not affected by splenectomy before or during torpor. Reversible thrombocytopenia was also induced by forced hypothermia in both hibernating (hamster) and non-hibernating (rat and mouse) species without changing platelet function. Pharmacological torpor induced by injection of 5′-AMP in mice did not induce thrombocytopenia, possibly because 5′-AMP inhibits platelet function. The rapidness of changes in the numbers of circulating platelets, as well as marginal changes in immature platelet fractions upon arousal, strongly suggest that storage-and-release underlies the reversible thrombocytopenia during natural torpor. Possibly, margination of platelets

  4. Numerical and experimental investigation of natural flow-induced vibrations of flexible hydrofoils

    NASA Astrophysics Data System (ADS)

    Chae, Eun Jung; Akcabay, Deniz Tolga; Lelong, Alexandra; Astolfi, Jacques Andre; Young, Yin Lu

    2016-07-01

    The objective of this work is to present combined numerical and experimental studies of natural flow-induced vibrations of flexible hydrofoils. The focus is on identifying the dependence of the foil's vibration frequencies and damping characteristics on the inflow velocity, angle of attack, and solid-to-fluid added mass ratio. Experimental results are shown for a cantilevered polyacetate (POM) hydrofoil tested in the cavitation tunnel at the French Naval Academy Research Institute (IRENav). The foil is observed to primarily behave as a chordwise rigid body and undergoes spanwise bending and twisting deformations, and the flow is observed to be effectively two-dimensional (2D) because of the strong lift retention at the free tip caused by a small gap with a thickness less than the wall boundary layer. Hence, the viscous fluid-structure interaction (FSI) model is formulated by coupling a 2D unsteady Reynolds-averaged Navier-Stokes (URANS) model with a two degree-of-freedom (2-DOF) model representing the spanwise tip bending and twisting deformations. Good agreements were observed between viscous FSI predictions and experimental measurements of natural flow-induced vibrations in fully turbulent and attached flow conditions. The foil vibrations were found to be dominated by the natural frequencies in absence of large scale vortex shedding due to flow separation. The natural frequencies and fluid damping coefficients were found to vary with velocity, angle of attack, and solid-to-fluid added mass ratio. In addition, the numerical results showed that the in-water to in-air natural frequency ratios decreased rapidly, and the fluid damping coefficients increased rapidly, as the solid-to-fluid added mass ratio decreases. Uncoupled mode (UM) linear potential theory was found to significantly over-predict the fluid damping for cases of lightweight flexible hydrofoils, and this over-prediction increased with higher velocity and lower solid-to-fluid added mass ratio.

  5. Models of Drug-induced Liver Injury for Evaluation of Phytotherapeutics and Other Natural Products

    PubMed Central

    Jaeschke, Hartmut; Williams, C. David; McGill, Mitchell R.; Xie, Yuchao; Ramachandran, Anup

    2013-01-01

    Extracts from medicinal plants, many of which have been used for centuries, are increasingly tested in models of hepatotoxicity. One of the most popular models to evaluate the hepatoprotective potential of natural products is acetaminophen (APAP)-induced liver injury, although other hepatotoxicity models such as carbon tetrachloride, thioacetamide, ethanol and endotoxin are occasionally used. APAP overdose is a clinically relevant model of drug-induced liver injury. Critical mechanisms and signaling pathways, which trigger necrotic cell death and sterile inflammation, are discussed. Although there is increasing understanding of the pathophysiology of APAP-induced liver injury, the mechanism is complex and prone to misinterpretation, especially when unknown chemicals such as plant extracts are tested. This review discusses the fundamental aspects that need to be considered when using this model, such as selection of the animal species or in vitro system, timing and dose-responses of signaling events, metabolic activation and protein adduct formation, the role of lipid peroxidation and apoptotic versus necrotic cell death, and the impact of the ensuing sterile inflammatory response. The goal is to enable researchers to select the appropriate model and experimental conditions for testing of natural products that will yield clinically relevant results and allow valid interpretations of the pharmacological mechanisms. PMID:23353004

  6. Inducing uniform single-crystal like orientation in natural rubber with constrained uniaxial stretch.

    PubMed

    Zhou, Weiming; Meng, Lingpu; Lu, Jie; Wang, Zhen; Zhang, Wenhua; Huang, Ningdong; Chen, Liang; Li, Liangbin

    2015-07-01

    The effect of flow on crystallization is commonly attributed to entropic reduction, which is caused by stretch and orientation of polymer chains but overlooks the role of flow on final-state free energy. With the aid of in situ synchrotron radiation wide-angle X-ray diffraction (WAXD) and a homemade constrained uniaxial tensile testing machine, polycrystals possessing single-crystal-like orientation rather than uniaxial orientation are found during the constrained stretch of natural rubber, whereas the c-axis and a-axis align in the stretch direction (SD) and constrained direction (CD), respectively. Molecular dynamics simulation shows that aligning the a-axis of crystal nuclei in CD leads to the lowest free energy increase and favors crystal nucleation. This indicates that the nomenclature of strain-induced crystallization may not fully account for the nature of flow-induced crystallization (FIC) as strain mainly emphasizes the entropic reduction of initial melt, whereas stress rather than strain plays the dominant role in crystal deformation. The current work not only contributes to a comprehensive understanding of the mechanism of flow-induced crystallization but also demonstrates the potential application of constrained uniaxial tensile stretch for the creation of functional materials containing polycrystals that possess single-crystal-like orientation. PMID:26021287

  7. [Natural inducing factors of grape bud dormancy and their regulation on respiratory metabolism during dormancy induction].

    PubMed

    Wang, Hai-bo; Wang, Xiao-di; Shi, Xiang-bin; Wang, Bao-liang; Zheng, Xiao-cui; Liu, Feng-zhi

    2015-12-01

    High chilling requirement grape (Vitis vinifera-V. labrusca cv. Summer Black) was used to evaluate its dormancy under short sunlight day (SD), long sunlight day (LD) and natural condition (CK). The results indicated that grape bud dormancy could be induced by natural low temperature and short sunlight alone or together. Short sunlight was the main contributor to the dormancy of grape bud, followed by natural low temperature. SD had more effect on dormancy induction under the same temperature when compared with LD. The grape dormancy induction stopped when the total respiratory rate reached the highest level. During the dormancy induction period, the proportion of pentose phosphate pathway (PPP) operation activity or capacity to total respiratory rate increased from 16.0% to 20.1% or 22.3% to 26.0%, respectively; similarly, the proportion of operation activity or capacity of alternate pathway to total respiratory rate rapidly increased, i.e., from 19.4% to 27.3% or 38.2% to 46.8%. Both low temperature and short sunlight could induce change of respiratory pathway on electron transport chain level. PMID:27112009

  8. The collapse of the Maya: Effects of natural and human-induced drought

    SciTech Connect

    Oglesby, Robert J; Erickson III, David J

    2010-02-01

    The collapse of the Maya civilization during the ninth century A.D. is a major conundrum in the history of mankind. This civilization reached a spectacular peak but then almost completely collapsed in the space of a few decades. While numerous explanations have been put forth to explain this collapse, in recent years, drought has gained favor. This is because water resources were a key for the Maya, especially to ensure their survival during the lengthy dry season that occurs where they lived. Natural drought is a known, recurring feature of this region, as evidenced by observational data, reconstructions of past times, and global climate model output. Results from simulations with a regional climate model demonstrate that deforestation by the Maya also likely induced warmer, drier, drought-like conditions. It is therefore hypothesized that the drought conditions devastating the Maya resulted from a combination of natural variability and human activities. Neither the natural drought or the human-induced effects alone were sufficient to cause the collapse, but the combination created a situation the Maya could not recover from. These results may have sobering implications for the present and future state of climate and water resources in Mesoamerica as ongoing massive deforestation is again occurring.

  9. Resistivity and induced polarization monitoring of salt transport under natural hydraulic gradients

    SciTech Connect

    Slater, L.D.; Sandberg, S.K.

    2000-04-01

    The authors demonstrate the use of resistivity/induced polarization (IP) monitoring of salt transport under natural hydraulic loads. Electrical monitoring of saline tracer transport during forced injection has been demonstrated previously. Detection of tracer transport under natural hydraulic loading is difficult because neither the hydraulic load nor the tracer resistivity can be controlled. In one study, the authors identify the electrical response to salt transport in a dynamic beach environment. Resistivity/IP imagine resolved the structure of the saltwater-freshwater interface and evidence for tide-induced groundwater transport. Resistivity increases in the near surface and at depth, upbeach of the high-tide mark, accompanied by tidal transgression. They attribute this to desaturation and decreasing salinity in the near surface and to decreasing salinity at depth, despite tidal transgression. Monitoring of groundwater levels indicates a phase lag between the tide level and groundwater level, supporting the electrical data. IP was insensitive to groundwater salinity variation. In a second study, the authors identify the electrical response to recharge-induced salt transport from a road-sale storage facility. Conductivity and IP models for monitoring lines, located on the basis of an EM31 survey, resolved the subsurface salt distribution, IP modeling resolved the sediment-bedrock interface. Modeling of monthly conductivity differences revealed conductivity increases and decreases at the locations of salt contamination, which correlate with the recharge pattern. They attribute near-surface conductivity increases after heavy rainfall to increasing saturation and ion dissolution. Corresponding conductivity decreases at depth are attributed to flushing of the bedrock with freshwater. Essentially, the opposite response was observed during a quiet monitoring period following heavy recharge. Near-surface IP changes are consistent with this interpretation. Salt

  10. Mobilization of natural killer cells inhibits development of collagen-induced arthritis.

    PubMed

    Leavenworth, Jianmei W; Wang, Xiaoyang; Wenander, Carola Schellack; Spee, Pieter; Cantor, Harvey

    2011-08-30

    Although natural killer (NK) cells have been implicated in regulating immune responses, their ability to modulate disease development in autoimmune arthritis has not been analyzed. Here we investigate the contribution of NK cells to regulating collagen-induced arthritis, a well-characterized preclinical model of human rheumatoid arthritis. We find that the disease is induced by the combined action of two CD4(+) T helper (T(H)) subsets: follicular T(H) cells and T(H)17 cells. Both CD4(+) T(H) subsets are highly susceptible to lysis by NK cells after activation. Administration of antibody that activates NK cells through blockade of its inhibitory CD94/NKG2A receptor allows enhanced elimination of pathogenic follicular T(H) and T(H)17 cells and arrest of disease progression. These results suggest that antibody-dependent enhancement of NK activity may yield effective, previously undescribed therapeutic approaches to this autoimmune disorder. PMID:21873193

  11. Inhibition of hematopoietic recovery from radiation-induced myelosuppression by natural killer cells

    SciTech Connect

    Pantel, K.; Boertman, J.; Nakeff, A. )

    1990-05-01

    We have examined the role of natural killer (NK) cells in situ in the recovery of marrow hematopoiesis in B6D2F1 mice receiving various doses of total-body irradiation (TBI) as a well-characterized model for treatment-induced myelosuppression. Applying an in situ cytotoxic approach for ablating NK 1.1 cells, we have demonstrated that NK 1.1 cells differentially inhibit the recovery of hematopoietic stem cells (CFU-S) and their progenitor cells committed to granulocyte-macrophage differentiation from a sublethal dose of TBI (9 Gy) while not affecting the recovery of progenitor cells committed to either erythroid or megakaryocyte differentiation from TBI. However, recoveries of CFU-S and progenitor cells were unaffected by the ablation of NK cells prior to a moderate dose of TBI (2 Gy). These findings provide in situ evidence that NK cells are potential inhibitors of hematopoietic recovery from treatment-induced myelosuppression.

  12. Inhibition of HDAC increases the senescence induced by natural polyphenols in glioma cells.

    PubMed

    Vargas, José E; Filippi-Chiela, Eduardo C; Suhre, Tais; Kipper, Franciele C; Bonatto, Diego; Lenz, Guido

    2014-08-01

    Cellular senescence is an irreversible block of cellular division, and induction of senescence is being considered for treatment of many cancer types, mainly those resistant to classical pro-apoptotic therapies. Resveratrol (Rsv) and quercetin (Quer), two natural polyphenols, are able to induce senescence in different cancer models, including gliomas, the most common and aggressive primary brain tumor. These polyphenols modulate the activity of several proteins involved in cell growth and death in cancer cells, including histone deacetylases (HDAC), but the role of HDAC in senescence induced by Rsv and Quer is unclear. The HDAC inhibitor sodium butyrate (NaB) potentiated the pro-senescent effect of Rsv and Quer in human and rat glioma cell lines but not in normal rat astrocytes. Furthermore, the increment of Quer-induced senescence by NaB was accompanied by an increase of reactive oxygen species levels and an increment of the number of cells with nuclear abnormalities. Altogether, these data support a positive role of HDAC inhibition on the senescence induced by these polyphenols, and therefore co-treatment of HDAC inhibitors and polyphenols emerges as a potential alternative for gliomas. PMID:25070040

  13. Amelioration of azoxymethane induced-carcinogenesis by reducing oxidative stress in rat colon by natural extracts

    PubMed Central

    2014-01-01

    Background Azoxymethane (AOM) is a potent carcinogenic agent commonly used to induce colon cancer in rats; the cytotoxicity of AOM is considered to mediate oxidative stress. This study investigated the chemopreventive effect of three natural extracts [pomegranate peel extract (PomPE), papaya peel extract (PapPE) and seaweed extract (SE)] against AOM-induced oxidative stress and carcinogenesis in rat colon. Methods Eighty Sprague–Dawley rats (aged 4 weeks) were randomly divided into 8 groups (10 rats/group). Control group was fed a basal diet; AOM-treated group was fed a basal diet and received AOM intraperitonial injections for two weeks at a dose of 15 mg/kg bodyweight, whereas the other six groups were received oral supplementation of PomPE, PapPE or SE, in the presence or absence of AOM injection. All animals were continuously fed ad-libitum until aged 16 weeks, then all rats were sacrificed and the colon tissues were examined microscopically for pathological changes and aberrant crypt foci (ACF) development, genotoxicity (induced micronuclei (MN) cells enumeration), and glutathione and lipid peroxidation. Results Our results showed that AOM-induced ACF development and pathological changes in the colonic mucosal tissues, increased bone marrow MN cells and oxidative stress (glutathione depletion, lipid peroxidation) in rat colonic cells. The concomitant treatment of AOM with PomPE, PapPE or SE significantly ameliorated the cytotoxic effects of AOM. Conclusions The results of this study provide in-vivo evidence that PomPE, PapPE and SE reduced the AOM-induced colon cancer in rats, through their potent anti-oxidant activities. PMID:24533833

  14. Assay Development for the Discovery of Semaphorin 3B Inducing Agents from Natural Product Sources

    PubMed Central

    Yong, Yeonjoong; Pan, Li; Ren, Yulin; Fatima, Nighat; Ahmed, Safia; Chang, Leng Chee; Zhang, Xiaoli; Kinghorn, A. Douglas; Swanson, Steven M.; Carcache de Blanco, Esperanza J.

    2014-01-01

    Semaphorins are a class of membrane-bound and secreted proteins. They have been found to regulate basic cell functions such as axonal growth cone guidance and recent studies have focused on their effect on tumor progression. Semaphorin 3B (Sema 3B) particularly is a secreted protein that has been known to modulate proliferation and apoptosis, processes that are critical for tumor progression and development. In spite of its importance, there is yet no high-throughput screening assay available to detect or quantify the expression of Sema 3B for natural product anticancer drug discovery purposes. Therefore, the development of a new high-throughput bioassay for the discovery of Sema 3B inducing agents from natural product sources is described herein. A wide variety of pure compounds and extracts from plants and microorganisms has been found suitable for screening using this Sema 3B assay to detect and quantify the effect of Sema 3B inducing agents and thereby identify new selective bioactive Sema 3B lead compounds for anticancer drug discovery and development. Also, this new bioassay procedure is based on a high-throughput platform using an enzyme-linked immunosorbent assay that involves the optimization of sensitivity and selectivity levels as well as accuracy, reproducibility, robustness, and cost effectiveness. PMID:25016954

  15. Patient-specific naturally gene-reverted induced pluripotent stem cells in recessive dystrophic epidermolysis bullosa.

    PubMed

    Tolar, Jakub; McGrath, John A; Xia, Lily; Riddle, Megan J; Lees, Chris J; Eide, Cindy; Keene, Douglas R; Liu, Lu; Osborn, Mark J; Lund, Troy C; Blazar, Bruce R; Wagner, John E

    2014-05-01

    Spontaneous reversion of disease-causing mutations has been observed in some genetic disorders. In our clinical observations of severe generalized recessive dystrophic epidermolysis bullosa (RDEB), a currently incurable blistering genodermatosis caused by loss-of-function mutations in COL7A1 that results in a deficit of type VII collagen (C7), we have observed patches of healthy-appearing skin on some individuals. When biopsied, this skin revealed somatic mosaicism resulting in the self-correction of C7 deficiency. We believe this source of cells could represent an opportunity for translational 'natural' gene therapy. We show that revertant RDEB keratinocytes expressing functional C7 can be reprogrammed into induced pluripotent stem cells (iPSCs) and that self-corrected RDEB iPSCs can be induced to differentiate into either epidermal or hematopoietic cell populations. Our results give proof-of-principle that an inexhaustible supply of functional patient-specific revertant cells can be obtained--potentially relevant to local wound therapy and systemic hematopoietic cell transplantation. This technology may also avoid some of the major limitations of other cell therapy strategies, e.g., immune rejection and insertional mutagenesis, which are associated with viral- and nonviral-mediated gene therapy. We believe this approach should be the starting point for autologous cellular therapies using 'natural' gene therapy in RDEB and other diseases. PMID:24317394

  16. Examining the impact of thought substitution on intentional forgetting in induced and naturally occurring dysphoria.

    PubMed

    Noreen, Saima; Ridout, Nathan

    2016-07-30

    Two experiments were conducted to determine if natural and induced dysphoria is associated with impaired forgetting and, whether a thought-substitution strategy would ameliorate any observed deficits. Study 1: 36 dysphoric & 36 non-dysphoric participants learnt a series of emotional word pairs. Participants were subsequently presented with some of the cues and were asked to recall the targets or prevent the targets from coming to mind. Half of the participants were provided with substitute words to recall instead of the original targets (aided suppression). At final memory testing, participants were asked to recall the targets to all cues. Dysphoric participants exhibited impaired forgetting, even when using a thought substitution strategy. Non-dysphoric participants, however, were able to use substitutes to suppress words. Study 2: 50 healthy participants initially completed the aided condition of the forgetting task. Participants were then given a positive or negative mood-induction, followed by another version of the forgetting task. Although all participants showed a forgetting effect prior to the mood-induction, only the positive group was successful at forgetting after the mood induction. Taken together, these findings do not support the utility of thought-substitution as an aid to forgetting in individuals in a naturally or induced dysphoric mood. PMID:27209358

  17. Stochastic nature and red cell population distribution of the sickling-induced Ca2+ permeability.

    PubMed Central

    Lew, V L; Ortiz, O E; Bookchin, R M

    1997-01-01

    To explore basic properties of the sickling-induced cation permeability pathway, the Ca2+ component (Psickle-Ca) was studied in density-fractionated sickle cell anemia (SS) discocytes through its effects on the activity of the cells' Ca2+sensitive K+-channels (KCa). The instant state of KCa channel activation was monitored during continuous or cyclic deoxygenation of the cells using a novel thiocyanate-densecell formation method. Each deoxy pulse caused a reversible, sustained Psickle-Ca, which activated KCa channels in only 10-45% of cells at physiological [Ca2+]o ("activated cells"). After removal of cells activated by each previous deoxy pulse, subsequent pulses generated similar activated cell fractions, indicating a random determination rather than the response of a specific vulnerable subpopulation. The fraction of activated cells rose monotonically with [Ca2+]o along a curve reflecting the cells' distribution of Psickle-Ca, with values high enough in a small cell fraction to trigger near-maximal KCa channels. Consistent with the stochastic nature of Psickle-Ca, repeated deoxygenated-oxygenated pulsing led to progressive dense cell formation, whereas single long pulses caused one early density shift. Thus deoxygenation-induced Ca2+-permeabilization in SS cells is a probabilistic event with large cumulative dehydrating potential. The possible molecular nature of Psickle-Ca is discussed. PMID:9169503

  18. Natural and Induced Fracture Diagnostics from 4-D VSP Low Permeability Gas Reservoirs

    SciTech Connect

    Mark E. Willis; Daniel R. Burns; M. Nafi Toksoz

    2008-09-30

    Tight gas sand reservoirs generally contain thick gas-charged intervals that often have low porosity and very low permeability. Natural and induced fractures provide the only means of production. The objective of this work is to locate and characterize natural and induced fractures from analysis of scattered waves recorded on 4-D (time lapse) VSP data in order to optimize well placement and well spacing in these gas reservoirs. Using model data simulating the scattering of seismic energy from hydraulic fractures, we first show that it is possible to characterize the quality of fracturing based upon the amount of scattering. In addition, the picked arrival times of recorded microseismic events provide the velocity moveout for isolating the scattered energy on the 4-D VSP data. This concept is applied to a field dataset from the Jonah Field in Wyoming to characterize the quality of the induced hydraulic fractures. The time lapse (4D) VSP data from this field are imaged using a migration algorithm that utilizes shot travel time tables derived from the first breaks of the 3D VSPs and receiver travel time tables based on the microseismic arrival times and a regional velocity model. Four azimuthally varying shot tables are derived from picks of the first breaks of over 200 VSP records. We create images of the fracture planes through two of the hydraulically fractured wells in the field. The scattered energy shows correlation with the locations of the microseismic events. In addition, the azimuthal scattering is different from the azimuthal reflectivity of the reservoir, giving us more confidence that we have separated the scattered signal from simple formation reflectivity. Variation of the scattered energy along the image planes suggests variability in the quality of the fractures in three distinct zones.

  19. Standoff detection of natural bioaerosol by range-gated laser-induced fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Buteau, Sylvie; Simard, Jean-Robert; Roy, Gilles

    2005-11-01

    The biological threat has emerged as one of today's primary security challenges due to the increased accessibility to biological warfare technology and the limited efficiency of detection and protection measures against such menace. Defence Research and Development Canada (DRDC) has investigated various methods, including the improvement of atmospheric bioaerosol monitoring, to increase the readiness against such threat. By the end of the 90s, DRDC developed a standoff bioaerosol sensor based on intensified range-gated spectrometric detection of Laser Induced Fluorescence (LIF). This work has showed an important potential of detecting and discriminating in real-time several bioaerosols. The LIDAR system that monitors atmosphere cells from a standoff position induces specific spectrally wide fluorescence signals originating from inelastic interactions with complex molecules forming the building blocks of the bioaerosols. This LIF signal is spectrally collected by a combination of a dispersive element and a range-gated ICCD that records the spectral information within a range-selected atmospheric volume. To assess further the potential of discrimination of such technique, this innovative sensor was used to obtain spectral data of various natural bioaerosols. In order to evaluate the discrimination of biological agent simulants from naturally occurring background fluorescing materials, the obtained results were compared with the ones of bioaerosol simulants (Bacillius subtilis var globiggi (BG) and Erwinia herbicola (EH)) acquired in 2001. The robustness of the spectral data with time was also investigated. From our results, most of the studied natural materials showed a spectral shift of various degrees, and up to 10 nm, to the longer wavelength one year later.

  20. Characterization of Natural Attenuation in a uranium-contaminated site by means of Induced Polarization Imaging

    NASA Astrophysics Data System (ADS)

    Flores Orozco, Adrián; Bücker, Matthias; Williams, Kenneth

    2014-05-01

    Field experiments at the U.S. Department of Energy's (DOE) Integrated Field Research Challenge site (IFRC) in Rifle, Colorado (USA) have repeatedly demonstrated the ability of microorganisms to reductively immobilize uranium (U) in U tailings-contaminated groundwater accompanying organic carbon amendment. At the same time, geophysical monitoring during such amendment experiments has proven that Induced Polarization (IP) datasets can provide valuable information regarding geochemical changes induced by stimulated microbial activity, such as precipitation of metallic minerals (e.g. FeS) and accumulation of reactive, electroactive ions (Fe[II]). Based on these findings, we present a novel, modified application of the IP imaging method. Specifically, we utilized an IP characterization approach to delineate areas where fluvially deposited organic material, within aquifer sediments, naturally stimulates the activity of subsurface microflora, leading to both the natural immobilization of uranium and accumulation of reduced end-products (minerals and pore fluids) capable of generating anomalous IP signatures. These so-called 'naturally reduced zones' (NRZ's) are characterized by elevated rates of microbial activity relative to sediments having a lower concentration of organic matter. As noted and based on our previous experiments at the site, the accumulation of metallic minerals represents suitable targets for the exploration with IP tomographic methods. Here, we explore the application of the IP imaging method for the characterization of NRZ's at the scale of the floodplain. We present imaging results obtained through the inversion of 70 independent lines distributed along the floodplain (~600 m2). Imaging results are validated through comparisons with lithological data obtained from wells drilled at the site and laboratory analysis of sediment and groundwater samples. Our results show the applicability of the IP method for characterizing regions of the subsurface having

  1. Tumor necrosis factor-{alpha} enhances IL-15-induced natural killer cell differentiation

    SciTech Connect

    Lee, Jiwon; Lee, Suk Hyung; Shin, Nara; Jeong, Mira; Kim, Mi Sun; Kim, Mi Jeong; Yoon, Suk Ran; Chung, Jin Woong; Kim, Tae-Don; Choi, Inpyo

    2009-09-04

    The differentiation of natural killer (NK) cells is regulated by various factors including soluble growth factors and transcription factors. Here, we have demonstrated that tumor necrosis factor-{alpha} (TNF-{alpha}) is a positive regulator of NK cell differentiation. TNF-{alpha} augmented the IL-15-induced expression of NK1.1 and CD122 in mature NK cells, and TNF-{alpha} alone also induced NK cell maturation as well as IL-15. TNF-{alpha} also increased IFN-{gamma} production in NK cells in the presence of IL-15. Meanwhile, mRNA expression of several transcription factors, including T-bet and GATA-3, was increased by the addition of TNF-{alpha} and IL-15. In addition, TNF-{alpha} increased nuclear factor-kappa B (NF-{kappa}B) activity in NK cells and inhibition of NF-{kappa}B impeded TNF-{alpha}-enhanced NK cell maturation. Overall, these data suggest that TNF-{alpha} significantly increased IL-15-driven NK cell differentiation by increasing the expression of transcription factors that play crucial roles in NK cell maturation and inducing the NF-{kappa}B activity.

  2. Strain-induced crystallization and mechanical properties of functionalized graphene sheet-filled natural rubber

    SciTech Connect

    Ozbas, Bulent; Toki, Shigeyuki; Hsiao, Benjamin S.; Chu, Benjamin; Register, Richard A.; Aksay, Ilhan A.; Prud'homme, Robert K.; Adamson, Douglas H.

    2012-03-11

    The effects of functionalized graphene sheets (FGSs) on the mechanical properties and strain-induced crystallization of natural rubber (NR) are investigated. FGSs are predominantly single sheets of graphene with a lateral size of several hundreds of nanometers and a thickness of 1.5 nm. The effect of FGS and that of carbon black (CB) on the strain-induced crystallization of NR is compared by coupled tensile tests and X-ray diffraction experiments. Synchrotron X-ray scattering enables simultaneous measurements of stress and crystallization of NR in real time during sample stretching. The onset of crystallization occurs at significantly lower strains for FGS-filled NR samples compared with CB-filled NR, even at low loadings. Neat-NR exhibits strain-induced crystallization around a strain of 2.25, while incorporation of 1 and 4 wt % FGS shifts the crystallization to strains of 1.25 and 0.75, respectively. In contrast, loadings of 16 wt % CB do not significantly shift the critical strain for crystallization. Two-dimensional (2D) wide angle X-ray scattering patterns show minor polymer chain alignment during stretching, in accord with previous results for NR. Small angle X-ray scattering shows that FGS is aligned in the stretching direction, whereas CB does not show alignment or anisotropy. The mechanical properties of filled NR samples are investigated using cyclic tensile and dynamic mechanical measurements above and below the glass transition of NR.

  3. Nature and action of the mediators inducing maturation of the starfish oocyte.

    PubMed

    Kanatani, H

    1983-01-01

    The process of oocyte maturation and ovulation in starfish is triggered by a gonad-stimulating substance (GSS) present in the granules contained in the supporting cells of the nervous system. The GSS of Asterias amurensis is a polypeptide with a relative molecular mass (Mr) of about 2100, consisting of 22 amino acid residues. This peptide hormone is secreted from the nervous system and acts on the follicular cells around the oocyte to stimulate the production of the second mediator, maturation-inducing substance (MIS). MIS has been identified as 1-methyladenine. 1-Methyladenine acts on the surface of the oocyte, probably on the oocyte-surface factor, to induce the production of a cytoplasmic factor called maturation-promoting factor (MPF) in the ooplasm. This third mediator induces germinal vesicle breakdown and the subsequent processes of oocyte maturation up to the formation of the female pronucleus. MPF appears to be a phosphoprotein and is known in other animals. MPF obtained from any source appears to bring about nuclear membrane breakdown in both meiosis and mitosis, and the nature of MPF is very similar in vertebrates and invertebrates. PMID:6357668

  4. Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells.

    PubMed

    Kihara, Yusuke; Yustiawati; Tanaka, Masato; Gumiri, Sulmin; Ardianor; Hosokawa, Toshiyuki; Tanaka, Shunitz; Saito, Takeshi; Kurasaki, Masaaki

    2014-08-01

    Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects. It was found that 50 mg/L HA showed cytotoxicity, which we considered to be mediated by apoptosis through the mitochondrial pathway because of an increase in the expression of caspases 6 and 9 in response to HA administration. In addition, this cytotoxicity was enhanced when cells in this experimental system were exposed to oxidative stress, while it was decreased by the addition of vitamin C. Thus, we conclude that the apoptosis induced by HA depends upon oxidative stress. Furthermore, an iron chelator, DFO, showed a tendency to decrease HA-induced cytotoxicity, suggesting that iron may potentially mediate HA-induced oxidative stress. In conclusion, long-term consumption of HA-rich water obtained from our study area may cause damage to endothelial cells and subsequent chronic health problems. PMID:23042718

  5. Natural compound Alternol induces oxidative stress-dependent apoptotic cell death preferentially in prostate cancer cells

    PubMed Central

    Tang, Yuzhe; Chen, Ruibao; Huang, Yan; Li, Guodong; Huang, Yiling; Chen, Jiepeng; Duan, Lili; Zhu, Bao-Ting; Thrasher, J Brantley; Zhang, Xu; Li, Benyi

    2014-01-01

    Prostate cancers at the late stage of castration resistance are not responding well to most of current therapies available in clinic, reflecting a desperate need of novel treatment for this life-threatening disease. In this study, we evaluated the anti-cancer effect of a recently isolated natural compound Alternol in multiple prostate cancer cell lines with the properties of advanced prostate cancers in comparison to prostate-derived non-malignant cells. As assessed by trypan blue exclusion assay, a significant cell death was observed in all prostate cancer cell lines except DU145 but not in non-malignant (RWPE-1and BPH1) cells. Further analyses revealed that Alternol-induced cell death was an apoptotic response in a dose- and time-dependent manner, as evidenced by the appearance of apoptosis hallmarks such as Caspase-3 processing and PARP cleavage. Interestingly, Alternol-induced cell death was completely abolished by reactive oxygen species (ROS) scavengers, N-acetylcysteine (N-Ac) and dihydrolipoic acid (DHLA). We also demonstrated that the pro-apoptotic Bax protein was activated after Alternol treatment and was critical for Alternol-induced apoptosis. Animal xenograft experiments in nude mice showed that Alternol treatment largely suppressed tumor growth of PC-3 xenografts but not Bax-null DU-145 xenografts in vivo. These data suggest that Alternol might serve as a novel anticancer agent for late stage prostate cancer patient. PMID:24688053

  6. New-to-nature sophorose analog: a potent inducer for gene expression in Trichoderma reesei.

    PubMed

    Huang, Tom Tao; Wages, John M

    2016-04-01

    Controlled hydrolysis of lactonic sophorolipids from Starmerella bombicola yields a previously undescribed sophorose analog that potently induces cellulase in Trichoderma reesei Rut-C30. Acid treatment of natural sophorolipids results in a mixture of monoacetylated, deacetylated, and diacetylated sophorolipids in acidic and lactonic forms. Isolation of the active components of the mixture, followed by structure determination by MS and NMR, reveals a new chemical entity, in which the lactone ring has been opened at the C-1' rather than at the C-4″ position of the sophorose moiety. This sophorose ester is resistant to degradation by the host and is at least 28 times more powerful an inducer than sophorose in shake-flask culture. Even at low concentrations (0.05 mM), the chemically modified sophorolipid effectively induces cellulase. With further improvements, this highly enabling technology can potentially reduce the cost of enzymes produced in T. reesei and can facilitate the rapid deployment of enzyme plants to support the nascent cellulosic biofuels and biochemicals industries. PMID:26920480

  7. Natural phenylpropanoids inhibit lipoprotein-induced endothelin-1 secretion by endothelial cells.

    PubMed

    Martin-Nizard, Françoise; Sahpaz, Sevser; Kandoussi, Abdelmejid; Carpentier, Marie; Fruchart, Jean-Charles; Duriez, Patrick; Bailleul, François

    2004-12-01

    There is increasing evidence that oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis of atherosclerosis and it has been reported that polyphenols inhibit LDL peroxidation and atherosclerosis. Endothelin-1 (ET-1) is a potent vasoconstrictor peptide isolated from endothelial cells and it induces smooth muscle cell proliferation. ET-1 secretion is increased in atheroma and induces deleterious effects such as vasospasm and atherosclerosis. The goal of this study was to test the effect of four natural phenolic compounds against copper-oxidized LDL (Cu-LDL)-induced ET-1 liberation by bovine aortic endothelial cells (BAEC). The tested compounds were phenylpropanoid glycosides previously isolated from the aerial parts of Marrubium vulgare L. (acteoside 1, forsythoside B 2, arenarioside 3 and ballotetroside 4). ET-1 secretion increased when cells were incubated with Cu-LDL but the compounds 1-4 inhibited this increase. These results were confirmed by quantitative-polymerase chain reaction (QPCR) analysis. Since ET-1 plays an important role in atherosclerosis development, our work suggests that the tested phenylpropanoids could have a beneficial effect in inhibiting atherosclerosis development. PMID:15563769

  8. AAV Natural Infection Induces Broad Cross-Neutralizing Antibody Responses to Multiple AAV Serotypes in Chimpanzees.

    PubMed

    Calcedo, Roberto; Wilson, James M

    2016-06-01

    Cross-sectional studies of primates have revealed that natural neutralizing antibody (NAb) responses to adeno-associated viruses (AAV) span multiple serotypes. This differs from the phenotype of the NAb response to an AAV vector delivered to seronegative nonhuman primates that is typically restricted to the administered AAV serotype. To better understand the mechanism by which natural AAV infections result in broad NAb responses, we conducted a longitudinal study spanning 10 years in which we evaluated serum-circulating AAV NAb levels in captive-housed chimpanzees. In a cohort of 25 chimpanzees we identified 3 distinct groups of animals: those that never seroconverted to AAV (naïve), those that were persistently seropositive (chronic), and those that seroconverted during the 10-year period (acute). For the chronic group we found a broad seroresponse characterized by NAbs reacting to multiple AAV serotypes. A similar cross-neutralization pattern of NAbs was observed in the acute group. These data support our hypothesis that a single natural infection with AAV induces a broadly cross-reactive NAb response to multiple AAV serotypes. PMID:27314914

  9. Differentiating induced and natural seismicity using space-time-magnitude statistics applied to the Coso Geothermal Field

    NASA Astrophysics Data System (ADS)

    Schoenball, Martin; Davatzes, Nicholas C.; Glen, Jonathan M. G.

    2016-04-01

    A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. The Coso Geothermal Field is one of the most seismically active areas in California and features an abundance of natural seismicity due to active tectonics and a large number of induced earthquakes resulting from geothermal power production since 1987. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the pre- and co-production periods from 1981 to 2013, we analyze inter-event times, spatial dimension, and frequency-size distributions for natural and induced earthquakes. Individually, these distributions are statistically indistinguishable. Determining the distribution of nearest-neighbor distances in a combined space-time-magnitude metric lets us identify the triggering relationship of an earthquake pair. Nearest-neighbors pairs naturally fall into two populations that categorize it as either clustered (triggered) or background (independent) events. Compared to natural earthquakes, induced earthquakes feature a larger fraction of background seismicity. Furthermore, they contain a population of independent pairs at large magnitude-rescaled times and small magnitude-rescaled distances. Unlike tectonic processes, stress changes by the field operations occur on much smaller time scale and appear strong enough to drive small-scale faults through several seismic cycles. As a result, we record seismicity close to previous hypocenters after a period on the order of a year.

  10. Natural and induced endoreic hydrological conditions in the Alta Murgia karstic region (Apulia, Southern Italy)

    NASA Astrophysics Data System (ADS)

    Canora, F.; Fidelibus, M. D.; Spilotro, G.

    2009-04-01

    , very large flow can cascade down towards more depressed areas. Another important feature of the Alta Murgia territory is that the whole area is characterised by a high degree of division into parcels, physically delimited by a well developed network of drystone walls. These have been built during centuries by using stones retrieved from the same fields, having the main role of preserving soils from erosion. The drystone walls that limit the parcels define induced endoreic conditions, where runoff, mostly prevented from discharging out, rather converges toward natural drainage systems and internal depressions, where afterwards infiltrates: the walls allow a high infiltration rate of precipitation of low and medium intensity with low evapotranspiration, while the runoff basically activates only during highest intensity events. The drystone walls have preserved in the time the characteristics of the karst surface, with its high hydraulic conductivity consequent to the negligible outcrop of soils; because of their capability of decreasing the runoff triggering threshold, drystone walls have always worked positively inside the endoreic and quasi-endoreic basins. The above characteristics of both natural and artificial endoreic basins indicate that the definition of the water balance for the Alta Murgia aquifer is complex, requiring a model able to take into account, not only the absorption capacity of the karstic surface textures (which, indeed, are able to delay the start of the runoff due to the need to reach first the saturation of terra rossa in the fissures, pockets and fillings of karst hollows) but also the hydraulic behaviour and geomorphological features of the basins constituting on the whole the recharge area. To make the situation even more complex, in the last decades, the territory was subject to a particular type of land use change, the stone shattering (that is performed by crushing and grinding the karst surface), aimed at making suitable the parcels for

  11. Nature and occurrence of cooling-induced cracking in volcanic rocks

    NASA Astrophysics Data System (ADS)

    Browning, John; Meredith, Philip G.; Gudmundssom, Agust

    2015-04-01

    Several hypotheses have been proposed regarding the role of thermo-mechanical contraction in producing cracks and joints in volcanic rocks. Nevertheless, most studies of thermally-induced cracking to date have focused on the generation of cracks formed during heating. In this latter case, the cracks are formed under an overall compressional regime. By contrast, cooling cracks are formed under an overall tensile regime. Therefore, both the nature and mechanism of crack formation during cooling are hypothesised to be different from those for crack formation during heating. Furthermore, it remains unclear whether cooling simply reactivates pre-existing cracks, induces the growth of new cracks, or both. We present results from experiments based on a new method for testing ideas on cooling-induced cracking. Cored samples of volcanic rock (basaltic to dacitic in composition) were heated at varying rates to different maximum temperatures inside a tube furnace. In the highest temperature experiments samples of both rocks were raised to the liquidus temperature appropriate to their composition, forcing melt interaction and crack annealing. We present in-situ seismic velocity and acoustic emission data, which were recorded throughout each heating and cooling cycle. It is found consistently that the rate of acoustic emission is much higher during cooling than during heating. In addition, acoustic emission events produced on cooling tend to be significantly higher in energy than those produced during heating. We therefore suggest that cracks formed during cooling are significantly larger than those formed during heating. Thin-section and crack morphology analysis of our cyclically heated samples provide further evidence of contrasting fracture morphologies. These new data are important for assessing the contribution of cooling-induced damage within volcanic structures and layers such as sills and lava flows. Our observations may also help to constrain evolving ideas regarding

  12. Four decades of opposing natural and human-induced artificial selection acting on Windermere pike (Esox lucius).

    PubMed

    Carlson, Stephanie M; Edeline, Eric; Asbjørn Vøllestad, L; Haugen, Thrond O; Winfield, Ian J; Fletcher, Janice M; Ben James, J; Stenseth, Nils Chr

    2007-06-01

    The ability of natural selection to drive local adaptation has been appreciated ever since Darwin. Whether human impacts can impede the adaptive process has received less attention. We tested this hypothesis by quantifying natural selection and harvest selection acting on a freshwater fish (pike) over four decades. Across the time series, directional natural selection tended to favour large individuals whereas the fishery targeted large individuals. Moreover, non-linear natural selection tended to favour intermediate sized fish whereas the fishery targeted intermediate sized fish because the smallest and largest individuals were often not captured. Thus, our results unequivocally demonstrate that natural selection and fishery selection often acted in opposite directions within this natural system. Moreover, the two selective factors combined to produce reduced fitness overall and stronger stabilizing selection relative to natural selection acting alone. The long-term ramifications of such human-induced modifications to adaptive landscapes are currently unknown and certainly warrant further investigation. PMID:17498150

  13. Thermally induced depolarization in terbium gallium garnet ceramics rod with natural convection cooling

    NASA Astrophysics Data System (ADS)

    Slezak, Ondrej; Yasuhara, Ryo; Lucianetti, Antonio; Vojna, David; Mocek, Tomas

    2015-06-01

    Thermal birefringence-induced depolarization in terbium gallium garnet (TGG) ceramic rods has been numerically evaluated for the geometry and heating conditions in a previous experiment. In this model, the spatially resolved heat transfer coefficient corresponding to natural convection cooling and the offset of the beam from the rotational axis of the rod have been incorporated and the realistic beam profile used in the experiment has been considered. A resulting beam depolarization ratio of 4.3 × 10-4 has been calculated for an input power of 117 W. The results were found to be in good agreement with the measured values. Furthermore, a parametric study of the depolarization ratio for higher input powers has been performed leading to a depolarization ratio of 3.3 × 10-2 for 1 kW input power.

  14. The opioid/nonopioid nature of stress-induced analgesia and learned helplessness.

    PubMed

    Maier, S F; Sherman, J E; Lewis, J W; Terman, G W; Liebeskind, J C

    1983-01-01

    Exposure to a variety of stressors produces a subsequent analgesic reaction. This stress-induced analgesia (SIA) is sometimes opioid in nature (reversed by opiate antagonists and cross-tolerant with morphine) and sometimes nonopioid. Both 30 min of intermittent footshock and 60-80 five-sec tailshocks have been shown to produce opioid SIA, whereas 3 min of continuous footshock and 5-40 tailshocks produce nonopioid SIA. We report that both of the opioid SIA procedures produce a learned helplessness effect as assessed by shuttlebox escape acquisition and an analgesia that is reinstatable 24 hr. later. The nonopioid procedures produce neither a learned helplessness effect nor a reinstatable analgesia. It is argued that these data implicate the learning of uncontrollability in the activation of opioid systems. PMID:6682435

  15. Polypropylene/natural rubber thermoplastic vulcanizates by eco-friendly and sustainable electron induced reactive processing

    NASA Astrophysics Data System (ADS)

    Mondal, Manas; Gohs, Uwe; Wagenknecht, Udo; Heinrich, Gert

    2013-07-01

    TPVs are a special class of thermoplastic and elastomer blend where cross-linking of elastomeric phase takes place during melt mixing process known as dynamic vulcanization (DV). A 50/50 blend of natural rubber (NR) and polypropylene (PP) were dynamically vulcanized using Electron Induced Reactive Processing (EIReP) as a function of absorbed dose (150, 250, and 350 kGy) at fixed electron energy (1.5 MeV) and dose per rotation. Different methods like tensile test, DSC, melt rheology, and SEM have been employed to understand the structure-property relationship of the prepared samples. The results suggest that EIReP is a novel technique to offer handful of additional features without compromising the end user property.

  16. Nature of Defects Induced by Au Implantation in Hexagonal Silicon Carbide Single Crystals

    SciTech Connect

    Gentils, Aurelie; Barthe, Marie-France; Egger, Werner; Sperr, Peter

    2009-03-10

    Pulsed-slow-positron-beam-based positron lifetime spectroscopy was used to investigate the nature of vacancy defects induced by 20 MeV Au implantation in single crystals 6H-SiC. Preliminary analysis of the data shows that at lower fluence, below 10{sup 14} cm{sup -2}, a positron lifetime of 220 ps has been obtained: it could be associated with the divacancy V{sub Si}-V{sub C} in comparison with the literature. At higher fluence, above 10{sup 15} cm{sup -2}, a positron lifetime of 260-270 ps, increasing with the incident positron energy, has been observed after decomposition of the lifetime spectra. By comparison with lifetime calculations, open-volumes such as quadrivacancy (V{sub Si}-V{sub C}){sub 2} clusters could be associated with this value.

  17. Excitation function of (3)He-particle induced nuclear reactions on natural palladium.

    PubMed

    Al-Abyad, M; Tárkányi, F; Ditrói, F; Takács, S

    2014-12-01

    Excitation functions of (3)He-particle induced nuclear reactions on natural palladium were measured using the standard stacked foil technique and high resolution γ-ray spectroscopy. From their threshold energies up to 27MeV, cross-sections for (nat)Pd((3)He,x)(103,104,105,106m,110m,111,112)Ag and (nat)Pd((3)He,x)(104,105,107,111m)Cd reactions were measured. The nuclear model codes TALYS-1.4, and EMPIRE-3.1 were used to describe the formation of these products. The present data were compared to theoretical results and to the available experimental data. Integral yields for some important radioisotopes were determined. PMID:25218461

  18. Methyl angolensate, a natural tetranortriterpenoid induces intrinsic apoptotic pathway in leukemic cells.

    PubMed

    Chiruvella, Kishore K; Kari, Vijayalakshmi; Choudhary, Bibha; Nambiar, Mridula; Ghanta, Rama Gopal; Raghavan, Sathees C

    2008-12-10

    Methyl angolensate (MA), a natural tetranortriterpenoid, purified from Soymida febrifuga is examined for the first time for its anticancer properties. We find that MA inhibits growth of T-cell leukemia and chronic myelogenous leukemia cells in a time- and dose-dependent manner. Accumulation of cells in the subG1 peak, annexin V binding and DNA fragmentation suggested induction of apoptosis. Besides, upregulation of BAD (proapoptotic) and downregulation of BCL2 (antiapoptotic) gene products further supported induction of apoptosis. Loss of mitochondrial membrane potential, activation of caspase 9, caspase 3, cleavage of PARP, downregulation of Ku70/80 and phosphorylation of MAP kinases suggested that MA could induce intrinsic pathway of apoptosis in leukemic cells. PMID:19022252

  19. Quantum nature of the sign preference in ion-induced nucleation.

    PubMed

    Nadykto, Alexey B; Al Natsheh, Anas; Yu, Fangqun; Mikkelsen, K V; Ruuskanen, J

    2006-03-31

    Observed first in Wilson's pioneering experiments in the cloud chamber, the sign preference has remained a mystery for more than a century. We investigate the sign preference using a quantum approach and show that this puzzling phenomenon is essentially quantum in nature. It is shown that the effect of the chemical identity of the core ion is controlled by the electronic structure of the core ion through the influence on the intermolecular bonding energies during the initial steps of cluster formation. Our results demonstrate the superiority of the quantum approach and indicate fundamental problems of conventional ion-induced nucleation theories, in which the electronic structure of the core ion is either ignored or not treated rigorously. PMID:16605928

  20. Bacteria grown on natural gas prevent soybean meal-induced enteritis in Atlantic salmon.

    PubMed

    Romarheim, Odd H; Øverland, Margareth; Mydland, Liv T; Skrede, Anders; Landsverk, Thor

    2011-01-01

    Dietary inclusion of solvent extracted soybean meal (SBM) is associated with inflammation in the distal intestine of salmonid fish, commonly referred to as SBM-induced enteritis. The enteritis is linked to alcohol soluble components in SBM, but the mechanisms have not been established. Previous studies show that bacterial meal (BM) containing mainly Methylococcus capsulatus grown on natural gas is a suitable protein source for salmonids. The BM is rich in nucleotides, phospholipids, and small peptides that might be beneficial for intestinal homeostasis. In this study, a fish meal (FM)-based control diet (FM diet) and diets with 200 g/kg SBM (SBM diet), 300 g/kg BM (BM diet), and 300 g/kg BM and 200 g/kg SBM (BM-SBM diet) were fed to juvenile Atlantic salmon (Salmo salar) for 80 d. Dietary inclusion of SBM reduced growth (P = 0.007). Inclusion of BM reduced digestibility of protein (P = 0.002) and lipids (P = 0.011) and increased (P < 0.01) the relative weights (g/kg whole body) of total gut, liver, and stomach, and mid and distal intestine. Fish fed the SBM diet developed enteritis, lacked carbonic anhydrase 12 in the brush border of epithelial cells in distal intestine, and had more epithelial cells reacting for proliferating cell nuclear antigen compared with fish fed the other diets. Fish fed the same amount of SBM combined with BM showed no signs of inflammation in the distal intestine. Our results demonstrate that BM grown on natural gas can be used to prevent SBM-induced enteritis in Atlantic salmon. PMID:21106922

  1. Effect of vehicle weight on natural frequencies of bridges measured from traffic-induced vibration

    NASA Astrophysics Data System (ADS)

    Kim, Chul-Young; Jung, Dae-Sung; Kim, Nam-Sik; Kwon, Soon-Duck; Feng, Maria Q.

    2003-06-01

    Recently, ambient vibration test (AVT) is widely used to estimate dynamic characteristics of large civil structures. Dynamic characteristics can be affected by various environmental factors such as humidity, intensity of wind, and temperature. Besides these environmental conditions, the mass of vehicles may change the measured values when traffic-induced vibration is used as a source of AVT for bridges. The effect of vehicle mass on dynamic characteristics is investigated through traffic-induced vibration tests on three bridges; (1) three-span suspension bridge (128m +404m + 128m), (2) five-span continuous steel box girder bridge (59m + 3@95m + 59m), (3) simply supported plate girder bridge (46m). Acceleration histories of each measurement location under normal traffic are recorded for 30 minutes at field. These recorded histories are divided into individual vibrations and are combined into two groups according to the level of vibration ; one by heavy vehicles such as trucks and buses and the other by light vehicles such as passenger cars. Separate processing of the two groups of signals shows that, for the middle and long-span bridges, the difference can be hardly detected, but, for the short span bridges whose mass is relatively small, the measured natural frequencies can change up to 5.4%.

  2. Porphyromonas gingivalis Lipopolysaccharide Induced Proliferation and Activation of Natural Killer Cells in Vivo.

    PubMed

    Wang, Yuhua; Zhang, Wei; Xu, Li; Jin, Jun-O

    2016-01-01

    Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) promoted different innate immune activation than that promoted by Escherichia coli (E. coli) LPS. In this study, we examined the effect of P. gingivalis LPS on the proliferation and activation of natural killer (NK) cells in vivo and compared that function with that of E. coli LPS. Administration of P. gingivalis LPS to C57BL/6 mice induced stronger proliferation of NK cells in the spleen and submandibular lymph nodes (sLNs) and increased the number of circulating NK cells in blood compared to those treated with E. coli LPS. However, P. gingivalis LPS did not induce interferon-gamma (IFN-γ) production and CD69 expression in the spleen and sLN NK cells in vivo, and this was attributed to the minimal activation of the spleen and sLN dendritic cells (DCs), including low levels of co-stimulatory molecule expression and pro-inflammatory cytokine production. Furthermore, P. gingivalis LPS-treated NK cells showed less cytotoxic activity against Yac-1 target cells than E. coli LPS-treated NK cells. Hence, these data demonstrated that P. gingivalis LPS promoted limited activation of spleen and sLN NK cells in vivo, and this may play a role in the chronic inflammatory state observed in periodontal disease. PMID:27548133

  3. Investigation of the α-particle induced nuclear reactions on natural molybdenum

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Hermanne, A.; Tárkányi, F.; Takács, S.; Ignatyuk, A. V.

    2012-08-01

    Cross-sections of alpha particle induced nuclear reactions on natural molybdenum have been studied in the frame of a systematic investigation of charged particle induced nuclear reactions on metals for different applications. The excitation functions of 93mTc, 93gTc(m+), 94mTc, 94gTc, 95mTc, 95gTc, 96gTc(m+), 99mTc, 93mMo, 99Mo(cum), 90Nb(m+), 94Ru, 95Ru,97Ru, 103Ru and 88Zr were measured up to 40 MeV alpha energy by using a stacked foil technique and activation method. The main goals of this work were to get experimental data for accelerator technology, for monitoring of alpha beam, for thin layer activation technique and for testing nuclear reaction theories. The experimental data were compared with critically analyzed published data and with the results of model calculations, obtained by using the ALICE-IPPE, EMPIRE and TALYS codes (TENDL-2011).

  4. A natural compound, methyl angolensate, induces mitochondrial pathway of apoptosis in Daudi cells.

    PubMed

    Chiruvella, Kishore K; Raghavan, Sathees C

    2011-08-01

    Natural products discovered from medicinal plants have played an important role in the treatment of cancer. In an effort to identify novel small molecules which can affect the proliferation of lymphoma cells, we tested methyl angolensate (MA), a plant derived tetranortriterpenoid, purified from the crude extract of the root callus of Soymida febrifuga commonly known as Indian red wood tree. We have tested MA for its cytotoxic properties on Burkitt's lymphoma cell lines, using various cellular assays. We observed that MA induces cytotoxicity in Daudi cells in a dose-dependent manner using trypan blue, MTT and LDH assays. We find that the treatment with MA led to activation of DNA double-strand break repair proteins including KU70 and KU80, suggesting the activation of nonhomologous DNA end joining pathway in surviving cells. Further, we find that methyl angolensate could induce apoptosis by cell cycle analysis, annexin V-FITC staining, DNA fragmentation and PARP cleavage. Besides, MA treatment led to reactive oxygen species generation and loss of mitochondrial transmembrane potential. These results suggest the activation of mitochondrial pathway of apoptosis. Hence, we identify MA as a potential chemotherapeutic agent against Daudi cells. PMID:20169399

  5. Natural selection underlies apparent stress-induced mutagenesis in a bacteriophage infection model.

    PubMed

    Yosef, Ido; Edgar, Rotem; Levy, Asaf; Amitai, Gil; Sorek, Rotem; Munitz, Ariel; Qimron, Udi

    2016-01-01

    The emergence of mutations following growth-limiting conditions underlies bacterial drug resistance, viral escape from the immune system and fundamental evolution-driven events. Intriguingly, whether mutations are induced by growth limitation conditions or are randomly generated during growth and then selected by growth limitation conditions remains an open question(1). Here, we show that bacteriophage T7 undergoes apparent stress-induced mutagenesis when selected for improved recognition of its host's receptor. In our unique experimental set-up, the growth limitation condition is physically and temporally separated from mutagenesis: growth limitation occurs while phage DNA is outside the host, and spontaneous mutations occur during phage DNA replication inside the host. We show that the selected beneficial mutations are not pre-existing and that the initial slow phage growth is enabled by the phage particle's low-efficiency DNA injection into the host. Thus, the phage particle allows phage populations to initially extend their host range without mutagenesis by virtue of residual recognition of the host receptor. Mutations appear during non-selective intracellular replication, and the frequency of mutant phages increases by natural selection acting on free phages, which are not capable of mutagenesis. PMID:27572836

  6. Infection with Wolbachia protects mosquitoes against Plasmodium-induced mortality in a natural system.

    PubMed

    Zélé, F; Nicot, A; Duron, O; Rivero, A

    2012-07-01

    In recent years, there has been a shift in the one host-one parasite paradigm with the realization that, in the field, most hosts are coinfected with multiple parasites. Coinfections are particularly relevant when the host is a vector of diseases, because multiple infections can have drastic consequences for parasite transmission at both the ecological and evolutionary timescales. Wolbachia pipientis is the most common parasitic microorganism in insects, and as such, it is of special interest for understanding the role of coinfections in the outcome of parasite infections. Here, we investigate whether Wolbachia can modulate the effect of Plasmodium on what is, arguably, the most important component of the vectorial capacity of mosquitoes: their longevity. For this purpose, and in contrast to recent studies that have focused on mosquito-Plasmodium and/or mosquito-Wolbachia combinations not found in nature, we work on a Wolbachia-mosquito-Plasmodium triad with a common evolutionary history. Our results show that Wolbachia protects mosquitoes from Plasmodium-induced mortality. The results are consistent across two different strains of Wolbachia and repeatable across two different experimental blocks. To our knowledge, this is the first time that such an effect has been shown for Plasmodium-infected mosquitoes and, in particular, in a natural Wolbachia-host combination. We discuss different mechanistic and evolutionary explanations for these results as well as their consequences for Plasmodium transmission. PMID:22533729

  7. Natural products and complementary therapies for chemotherapy-induced peripheral neuropathy: A systematic review.

    PubMed

    Brami, Cloé; Bao, Ting; Deng, Gary

    2016-02-01

    Chemotherapy-induced peripheral neuropathy (CIPN) is a serious dose-limiting side-effect without any FDA-approved treatment option. Prior reviews focus mostly on pharmacological interventions, but nonpharmaceutical interventions have also been evaluated. A Web of Science and PubMed database search to identify relevant RCTs from January 2005 to May 2015 included the terms: CIPN, cancer; and supplements, vitamin E, goshajinkigan, kampo, acetyl-L-carnitine, carnitine, alpha-lipoic acid, omega-3, glutamine, or glutamate; or massage, acupuncture, mind-body practice, yoga, meditation, Tai-Chi, physical activity, or exercise. Of 1465 publications screened, 12 RCTs evaluated natural products and one evaluated electroacupuncture. Vitamin E may help prevent CIPN. L-Glutamine, goshajinkigan, and omega-3 are also promising. Acetyl-L-carnitine may worsen CIPN and alpha-lipoic acid activity is unknown. Electroacupuncture was not superior to placebo. No RCTs were published regarding other complementary therapies, although some studies mention positive incidental findings. Natural products and complementary therapies deserve further investigation, given the lack of effective CIPN interventions. PMID:26652982

  8. Pressure induced stiffening, thermal softening of bulk modulus and brittle nature of mercury chalcogenides

    NASA Astrophysics Data System (ADS)

    Varshney, Dinesh; Shriya, Swarna; Sapkale, Raju; Varshney, Meenu; Ameri, M.

    2015-07-01

    The pressure and temperature dependent elastic properties of mercury chalcogenides (HgX; X = S, Se and Te) with pressure induced structural transition from ZnS-type (B3) to NaCl-type (B1) structure have been analyzed within the framework of a model interionic interaction potential with long-range Coulomb and charge transfer interactions, short-range overlap repulsion and van der Waals (vdW) interactions as well as zero point energy effects. Emphasis is on the evaluation of the Bulk modulus with pressure and temperature dependency to yield the Poisson's ratio ν, the Pugh ratio ϕ, anisotropy parameter, Shear and Young's modulus, Lamé's constant, Klein man parameter, elastic wave velocity and Debye temperature. The Poisson's ratio behavior infers that HgX are brittle in nature. To our knowledge this is the first quantitative theoretical prediction of the pressure dependence of elastic and thermodynamical properties explicitly the ductile (brittle) nature of HgX and still awaits experimental confirmations.

  9. Buoyancy and Pressure Induced Flow of Hot Gases in Vertical Shafts with Natural and Forced Ventilation

    NASA Astrophysics Data System (ADS)

    Jaluria, Yogesh; Tamm, Gunnar Olavi

    2014-11-01

    An experimental investigation was conducted to study buoyancy and pressure induced flow of hot gases in vertical shafts to model smoke propagation in elevator and ventilation shafts of high rise building fires. Various configurations were tested with regard to natural and forced ventilation imposed at the upper and lower surfaces of the vertical shaft. The aspect ratio was taken at a typical value of 6. From a lower vent, the inlet conditions for smoke and hot gases were varied in terms of the Reynolds and Grashof numbers. The forced ventilation at the upper or lower boundary was of the same order as the bulk shaft flow. Measurements were taken within the shaft to allow a detailed study of the steady state flow and thermal fields established for various shaft configurations and inlet conditions, from which optimal means for smoke alleviation in high rise building fires may be developed. Results indicated a wall plume as the primary transport mechanism for smoke propagating from the inlet towards the exhaust region. Recirculation and entrainment dominated at high inlet Grashof number flows, while increased inlet Reynolds numbers allowed greater mixing in the shaft. The development and stability of these flow patterns and their effects on the smoke behavior were assessed for several shaft configurations with different inlet conditions. The comparisons indicated that the fastest smoke removal and lowest overall shaft temperatures occur for a configuration with natural ventilation at the top surface and forced ventilation up from the shaft bottom.

  10. Investigations of plasma induced effects on the surface properties of lignocellulosic natural coir fibres

    NASA Astrophysics Data System (ADS)

    Praveen, K. M.; Thomas, Sabu; Grohens, Yves; Mozetič, Miran; Junkar, Ita; Primc, Gregor; Gorjanc, Marija

    2016-04-01

    The development of lignocellulosic natural-fibre-reinforced polymers composites are constrained by two limitations: the upper temperature at which the fibre can be processed and the significant differences between the surface energy of the fibre and the polymer matrix. Since the fibres and matrices are chemically different, strong adhesion at their interface is needed for the effective transfer of stress and bond distribution throughout the interface. The present study investigated the plasma induced effects on the surface properties of natural coir fibres. Weakly ionized oxygen plasma was created in two different discharge chambers by an inductively coupled radiofrequency (RF) discharge. The water absorption studies showed an increase of water sorption from 39% to 100%. The morphological study using scanning electron microscopy (SEM) analysis also confirmed the surface changes which were observed after the plasma treatment. The topographic measurements and phase imaging done using atomic force microscopy (AFM) indicated difference in topographic features and etching of coir wall, which points to the removal of the first layer of coir fibre. X-ray photoelectron spectroscopy (XPS) analysis revealed that the oxygen content measured for samples treated at 50 Pa increased from initial 18% to about 32%.

  11. Chiral Selective Chemistry Induced by Natural Selection of Spin-Polarized Electrons.

    PubMed

    Rosenberg, Richard A; Mishra, Debabrata; Naaman, Ron

    2015-06-15

    The search to understand the origin of homochirality in nature has been ongoing since the time of Pasteur. Previous work has shown that DNA can act as a spin filter for low-energy electrons and that spin-polarized secondary electrons produced by X-ray irradiation of a magnetic substrate can induce chiral selective chemistry. In the present work it is demonstrated that secondary electrons from a substrate that are transmitted through a chiral overlayer cause enantiomeric selective chemistry in an adsorbed adlayer. We determine the quantum yields (QYs) for dissociation of (R)- or (S)-epichlorohydrin adsorbed on a chiral self-assembled layer of DNA on gold and on bare gold (for control). The results show that there is a significant difference in the QYs between the two enantiomers when adsorbed on DNA, but none when they are adsorbed on bare Au. We propose that the effect results from natural spin filtering effects cause by the chiral monolayer. PMID:25950284

  12. Psychological Stress, Cocaine and Natural Reward Each Induce Endoplasmic Reticulum Stress Genes in Rat Brain

    PubMed Central

    Pavlovsky, Ashly A.; Boehning, Darren; Li, Dingge; Zhang, Yafang; Fan, Xiuzhen; Green, Thomas A.

    2013-01-01

    Our prior research has shown that the transcription of endoplasmic reticulum (ER) stress transcription factors Activating Transcription Factor 3 (ATF3) and ATF4 are induced by amphetamine and restraint stress in rat striatum. However, presently it is unknown the full extent of ER stress responses to psychological stress or cocaine, and which of the three ER stress pathways is activated. The current study examines transcriptional responses of key ER stress target genes subsequent to psychological stress or cocaine. Rats were subjected to acute or repeated restraint stress or cocaine treatment and mRNA was isolated from dorsal striatum, medial prefrontal cortex and nucleus accumbens brain tissue. ER stress gene mRNA expression was measured using quantitative PCR and RNA sequencing. Restraint stress and cocaine induced transcription of the classic ER stress-induced genes (BIP, CHOP, ATF3 and GADD34) and of two other ER stress components XBP1 and ATF6. In addition, rats living in an enriched environment (large group cage with novel toys changed daily) exhibited rapid induction of GADD34 and ATF3 after 30 min of exploring novel toys, suggesting these genes are also involved in normal non-pathological signaling. However, environmental enrichment, a paradigm that produces protective addiction and depression phenotypes in rats, attenuated the rapid induction of ATF3 and GADD34 after restraint stress. These experiments provide a sensitive measure of ER stress and, more importantly, these results offer good evidence of the activation of ER stress mechanisms from psychological stress, cocaine and natural reward. Thus, ER stress genes may be targets for novel therapeutic targets for depression and addiction. PMID:23644055

  13. Psychological stress, cocaine and natural reward each induce endoplasmic reticulum stress genes in rat brain.

    PubMed

    Pavlovsky, A A; Boehning, D; Li, D; Zhang, Y; Fan, X; Green, T A

    2013-08-29

    Our prior research has shown that the transcription of endoplasmic reticulum (ER) stress transcription factors activating transcription factor 3 (ATF3) and ATF4 are induced by amphetamine and restraint stress in rat striatum. However, presently the full extent of ER stress responses to psychological stress or cocaine, and which of the three ER stress pathways is activated is unknown. The current study examines transcriptional responses of key ER stress target genes subsequent to psychological stress or cocaine. Rats were subjected to acute or repeated restraint stress or cocaine treatment and mRNA was isolated from dorsal striatum, medial prefrontal cortex and nucleus accumbens brain tissue. ER stress gene mRNA expression was measured using quantitative polymerase chain reaction (PCR) and RNA sequencing. Restraint stress and cocaine-induced transcription of the classic ER stress-induced genes (BIP, CHOP, ATF3 and GADD34) and of two other ER stress components x-box binding protein 1 (XBP1) and ATF6. In addition, rats living in an enriched environment (large group cage with novel toys changed daily) exhibited rapid induction of GADD34 and ATF3 after 30 min of exploring novel toys, suggesting these genes are also involved in normal non-pathological signaling. However, environmental enrichment, a paradigm that produces protective addiction and depression phenotypes in rats, attenuated the rapid induction of ATF3 and GADD34 after restraint stress. These experiments provide a sensitive measure of ER stress and, more importantly, these results offer good evidence of the activation of ER stress mechanisms from psychological stress, cocaine and natural reward. Thus, ER stress genes may be targets for novel therapeutic targets for depression and addiction. PMID:23644055

  14. Photosensitized rose Bengal-induced phototoxicity on human melanoma cell line under natural sunlight exposure.

    PubMed

    Srivastav, Ajeet K; Mujtaba, Syed Faiz; Dwivedi, Ashish; Amar, Saroj K; Goyal, Shruti; Verma, Ankit; Kushwaha, Hari N; Chaturvedi, Rajnish K; Ray, Ratan Singh

    2016-03-01

    Rose Bengal (RB) is an anionic water-soluble xanthene dye, which used for many years to assess eye cornea and conjunctiva damage. RB showed strong absorption maxima (λmax) under visible light followed by UV-B and UV-A. RB under sunlight exposure showed a time-dependent photodegradation. Our results show that photosensitized RB generates (1)O2 via Type-II photodynamic pathway and induced DNA damage under sunlight/UV-R exposure. 2'dGuO degradation, micronuclei formation, and single- and double-strand breakage were the outcome of photogenotoxicity caused by RB. Quenching studies with NaN3 advocate the involvement of (1)O2 in RB photogenotoxicity. RB induced linoleic acid photoperoxidation, which was parallel to (1)O2-mediated DNA damage. Oxidative stress in A375 cell line (human melanoma cell line) was detected through DCF-DA assay. Photosensitized RB decreased maximum cellular viability under sunlight followed by UV-B and UV-A exposures. Apoptosis was detected as a pattern of cell death through the increased of caspase-3 activity, decreased mitochondrial membrane potential, and PS translocation through inner to outer plasma membrane. Increased cytosolic levels of Bax also advocate the apoptotic cell death. We propose a p53-mediated apoptosis via increased expression of Bax gene and protein. Thus, the exact mechanism behind RB phototoxicity was the involvement of (1)O2, which induced oxidative stress-mediated DNA and membrane damage, finally apoptotic cell death under natural sunlight exposure. The study suggests that after the use of RB, sunlight exposure may avoid to prevent from its harmful effects. PMID:26866294

  15. Natural furocoumarins as inducers and inhibitors of cytochrome P450 1A1 in rat hepatocytes.

    PubMed

    Baumgart, Annette; Schmidt, Melanie; Schmitz, Hans-Joachim; Schrenk, Dieter

    2005-02-15

    Furocoumarins are natural plant constituents present in medicinal plants and in a variety of foods such as grapefruit juice. They are phototoxic and act as potent inhibitors of drug metabolism. We have investigated the interaction of four furocoumarins angelicin, bergamottin, isopimpinellin, and 8-methoxypsoralen with the expression and activity of aryl hydrocarbon receptor (AhR)-regulated CYP1A1 in rat hepatocytes in primary culture, both in the presence and absence of light. In intact hepatocytes pretreated with 2,3,7,8-tetrachlorodibenzo-p-dioxin and in microsomes isolated thereof, all furocoumarins tested acted as potent inhibitors of CYP1A1 activity bergamottin being the most potent inhibitor in microsomes with an IC(50) of 10 nM in the presence and 60 nM in the absence of light. 8-Methoxypsoralen and angelicin led to a significant induction of CYP1A1 mRNA in hepatocytes, while all furocoumarins except bergamottin increased xenobiotic-responsive element-driven reporter gene expression in transfected H4IIE rat hepatoma cells when light was excluded. Furthermore, all furocoumarins tested induced the expression of endogenous, immunoreactive CYP1A1 protein, primarily in the dark. In conclusion, our results demonstrate that individual furocoumarins present in food and medicinal plants can interfere with AhR-regulated CYP1A1 expression and activity in at least three major ways, i.e., (i) act as highly potent inhibitors of the catalytic activity of CYP1A1 both in the presence and absence of light, (ii) induce CYP1A1 gene expression in the absence of light via activation of the AhR, and (iii) induce CYP1A1 gene expression without activation of the AhR. PMID:15670584

  16. Natural Disaster Induced Losses at Household Level: A Study on the Disaster Affected Migrants

    NASA Astrophysics Data System (ADS)

    Ishtiaque, A.; Nazem, N. I.; Jerin, T.

    2015-12-01

    Given its geographical location Bangladesh frequently confronts natural disasters. Disaster induced losses often obligate socio-economic dislocation from rural areas to large urban centers. After incurring what type/amount of losses people migrate is still unknown. In this paper we focus on migrants who migrated due to natural disasters. Thus, the objectives of this paper are, first, ascertaining the proportion of disaster migrants in Dhaka city; second, determining types of natural disasters which compel rural out-migration; third, assessing the resource and economic losses stem from these disasters at household level. Using the slum database (N = 4966), we select eight slums randomly with a purpose to include migrants from maximum districts available. In order to identify the proportion of disaster affected migrants a census is conducted in 407 households of those 8 slums and the result demonstrates that 18.43% of the migrants are disaster affected, which was only 5% in 1993. Out of all hydro-meteorological disasters, river bank erosion (RBE), followed by flood, drives most people out of their abode. However, unlike RBE migrants, migrants affected by flood usually return to their origin after certain period. In-depth interviews on the disaster migrants reveal that RBE claims total loss of homestead land & agricultural land while flood causes 20% and 23% loss respectively. Agricultural income decreases 96% because of RBE whereas flood victims encounter 98% decrease. People also incur 79% & 69% loss in livestock owing to RBE and flood severally. These disasters cause more than eighty percent reduction in total monthly income. Albeit RBE appears more vigorous but total economic loss is greater in flood- on average each household experiences a loss of BDT 350,555 due to flood and BDT 300,000 on account of RBE. Receiving no substantial support from community or government the affected people are compelled to migrate.

  17. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    SciTech Connect

    Sarkar, Ruma; Mukherjee, Sutapa; Biswas, Jaydip; Roy, Madhumita

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent

  18. Earthquake Seismic Risk Reduction in Ohio: ODNR's Efforts to Address Issues with Natural and Induced Seismicity

    NASA Astrophysics Data System (ADS)

    Besana-Ostman, G. M.

    2013-05-01

    With the increasing concerns regarding both natural and induced seismicity in Ohio, ODNR (Ohio Department of Natural Resources) initial efforts on seismic risk reduction paved way to various changes and improvement to tackle several major issues. For natural earthquakes, regional seismicity indicates a NE-SW structure in the northern portion of the area associated with a number of moderate historical earthquakes but no active trace identified. On the other hand, earthquakes of 1986 and 2011 are most probably incidents of induced seismicity that trigger more public uproar against disposal of regulated waste waters through injections. ODNR, in efforts to adapt with increasing need to regulate all operations related to both the Utica and Marcellus shale play within the state, had recently strengthen itself both through additional human resources and improved infrastructure. Tougher regulations and additional field tests were required that took effect immediately when a M4 earthquake was associated with the operations of an injection well. Public meetings were undertaken focused on educating many local inhabitants related to oil and gas operations, hydraulic fracturing, injection wells, and seismicity. Trainings for new and existing staff were regularly done especially for field inspection, data management and technology advancements. Considering the existing seismic stations that are few and distant related to sites of the injection wells, additional seismic stations were installed to gather baseline data and monitor for earthquakes within the injection area(s). Furthermore, to assess if the sites of the injection wells are safe from active structures, initial geomorphic and structural analyses indicated possible active faults in the northern portion of state oriented NE-SW. With the above-mentioned recent changes, ODNR had made a significant leap not only in the improvement of its principal regulatory role in the state for oil and gas operations but also in its

  19. Differentiating Induced and Natural Seismicity Using Space-Time-Magnitude Statistics Applied to the Coso Geothermal Field

    NASA Astrophysics Data System (ADS)

    Schoenball, M.; Davatzes, N. C.; Glen, J. M. G.

    2015-12-01

    A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. The Coso Geothermal Field is one of the most seismically active areas in California and features an abundance of natural seismicity due to active tectonics and a large number of induced earthquakes resulting from geothermal power production since 1987. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the pre- and co-production periods from 1981 to 2013, we analyze inter-event times, spatial dimension, and frequency-size distributions for natural and induced earthquakes. Individually, these distributions are statistically indistinguishable. Determining the distribution of nearest-neighbor distances in a combined space-time-magnitude metric lets us identify the triggering relationship of an earthquake pair. Nearest-neighbor pairs naturally fall into two populations that are categorized as either clustered (triggered) or background (independent) events. At Coso, induced earthquakes feature a larger fraction of background seismicity compared to natural earthquakes. Furthermore, they contain a population of independent pairs at large magnitude-rescaled times and small magnitude-rescaled distances. This implies that unlike tectonic processes, stress changes induced by the field operations occur on much smaller time scales and appear to be large enough to drive small-scale faults through several seismic cycles during relatively short observation period. As a result, we record events close to previous hypocenters that occur up to a year after the preceding earthquake.

  20. The nature of surround-induced depolarizing responses in goldfish cones.

    PubMed

    Kraaij, D A; Spekreijse, H; Kamermans, M

    2000-01-01

    Cones in the vertebrate retina project to horizontal and bipolar cells and the horizontal cells feedback negatively to cones. This organization forms the basis for the center/surround organization of the bipolar cells, a fundamental step in the visual signal processing. Although the surround responses of bipolar cells have been recorded on many occasions, surprisingly, the underlying surround-induced responses in cones are not easily detected. In this paper, the nature of the surround-induced responses in cones is studied. Horizontal cells feed back to cones by shifting the activation function of the calcium current in cones to more negative potentials. This shift increases the calcium influx, which increases the neurotransmitter release of the cone. In this paper, we will show that under certain conditions, in addition to this increase of neurotransmitter release, a calcium-dependent chloride current will be activated, which polarizes the cone membrane potential. The question is, whether the modulation of the calcium current or the polarization of the cone membrane potential is the major determinant for feedback-mediated responses in second-order neurons. Depolarizing light responses of biphasic horizontal cells are generated by feedback from monophasic horizontal cells to cones. It was found that niflumic acid blocks the feedback-induced depolarizing responses in cones, while the shift of the calcium current activation function and the depolarizing biphasic horizontal cell responses remain intact. This shows that horizontal cells can feed back to cones, without inducing major changes in the cone membrane potential. This makes the feedback synapse from horizontal cells to cones a unique synapse. Polarization of the presynaptic (horizontal) cell leads to calcium influx in the postsynaptic cell (cone), but due to the combined activity of the calcium current and the calcium-dependent chloride current, the membrane potential of the postsynaptic cell will be hardly

  1. Natural radioactivity contents in tobacco and radiation dose induced from smoking.

    PubMed

    Shousha, Hany A; Ahmad, Fawzia

    2012-06-01

    One of the causative factors for cancer-inducing mechanisms in humans is radioactive elements present in tobacco leaves used in the manufacture of cigarettes. Smoking of tobacco and its products increases the internal intake and radiation dose due to naturally occurring radionuclides that are considered to be one of the most significant causes of lung cancer. In this work, different commercial types of cigarettes, cigar and moassel were collected from market. Naturally occurring radionuclides (226)Ra and (214)Bi ((238)U series), (228)Ac and (228)Ra ((232)Th series), (40)K  and man-made (137)Cs were measured in tobacco using gamma-ray spectrometer. Results show that the average concentrations of (238)U, (232)Th and (40)K were 4.564, 3.940 and 1289.53 Bq kg(-1), respectively. This reflects their origin from the soil by root uptake and fertilisers used in the cultivation of tobacco plants. Concentration of (137)Cs was 0.348 Bq kg(-1) due to root uptake or deposition onto the leaf foliage. For smokers, the annual effective dose due to inhalation of (238)U varied from 49.35 to 139.40 μSv(-1) (average 104.27 μSv y(-1)), while of (232)Th from 23.86 to 111.06 μSv y(-1) (average 65.52 μSv y(-1)). The annual effective dose resulting from (137)Cs was varied from 10.96 to 24.01 nSv y(-1) (average 19.41 nSv y(-1)). PMID:21926418

  2. The Arctic freshwater cycle during a naturally and an anthropogenically induced warm climate

    NASA Astrophysics Data System (ADS)

    Davies, Frazer J.; Renssen, Hans; Goosse, Hugues

    2014-04-01

    The Arctic freshwater cycle plays an important role in regulating regional and global climate. Current observations suggest that an intensification of the high-northern latitude hydrological cycle has caused a freshening of the Arctic and sub-Arctic seas, increasing the potential of weakening overturning strength in the Nordic seas, and reducing temperatures. It is not known if this freshening is a manifestation of the current anthropogenic warming and if the Arctic freshwater cycle has exhibited similar changes in the past, in particular as a response to naturally induced periods of warming, for example during the mid-Holocene hypsithermal. Thus, we have used an earth model of intermediate complexity, LOVECLIM, to investigate the response of the Arctic freshwater cycle, during two warm periods that evolved under different sets of forcings, the mid-Holocene and the twenty-first century. A combination of proxy reconstructions and modelling studies have shown these two periods to exhibit similar surface temperature anomalies, compared to the pre-industrial period, however, it has yet to be determined if the Arctic freshwater cycle and thus, the transport and redistribution of freshwater to the Arctic and the sub-Arctic seas, during these two warm periods, is comparable. Here we provide an overview that shows that the response of the Arctic freshwater cycle during the first half of the twenty-first century can be interpreted as an `extreme' mid-Holocene hydrological cycle. Whilst for the remainder of the twenty-first century, the Arctic freshwater cycle and the majority of its components will likely transition into what can only be described as truly anthropogenic in nature.

  3. Advances in distinguishing natural from induced Foxp3(+) regulatory T cells.

    PubMed

    Lin, Xiaohong; Chen, Maogen; Liu, Ya; Guo, Zhiyong; He, Xiaoshun; Brand, David; Zheng, Song Guo

    2013-01-01

    For more than a decade now, the regulatory T (Treg) cell has widely been considered as a critical subpopulation of T cells which can suppress effector T cell responses as well as suppressing the activity of other immune cells, such as mast cell, dendritic cells, and B cells. Treg cells have been broadly characterized as comprising of two main populations: thymus-derived natural Treg (nTreg) cells, and peripherally generated induced Treg (iTreg) cells. Both subsets have similar phenotypic characteristics and comparable suppressive function against T cell-mediated immune response and diseases. However, both Foxp3 positive Treg subsets exhibit some specific differences such as different mRNA transcripts and protein expression, epigenetic modification, and stability. These subtle differences reinforce the notion that they represent unique and distinct subsets. Accurately distinguishing iTregs from nTregs will help to clarify the biological features and contributions of each Treg subsets in peripheral tolerance, autoimmunity and tumor immunity. One difficult problem is that it has not been possible to distinguish iTregs from nTregs using surface markers until two recent articles were published to address this possibility. This review will focus on very recent advances in using molecular markers to differentiate these Treg subsets. PMID:23329997

  4. Strong spontaneous tumor neoantigen responses induced by a natural human carcinogen

    PubMed Central

    Creaney, Jenette; Ma, Shaokang; Sneddon, Sophie A; Tourigny, Michelle R; Dick, Ian M; Leon, Justine S; Khong, Andrea; Fisher, Scott A; Lake, Richard A; Lesterhuis, W Joost; Nowak, Anna K; Leary, Shay; Watson, Mark W; Robinson, Bruce W

    2015-01-01

    A key to improving cancer immunotherapy will be the identification of tumor-specific “neoantigens” that arise from mutations and augment the resultant host immune response. In this study we identified single nucleotide variants (SNVs) by RNA sequencing of asbestos-induced murine mesothelioma cell lines AB1 and AB1-HA. Using the NetMHCpan 2.8 algorithm, the theoretical binding affinity of predicted peptides arising from high-confidence, exonic, non-synonymous SNVs was determined for the BALB/c strain. The immunoreactivity to 20 candidate mutation-carrying peptides of increased affinity and the corresponding wild-type peptides was determined using interferon-γ ELISPOT assays and lymphoid organs of non-manipulated tumor-bearing mice. A strong endogenous immune response was demonstrated to one of the candidate neoantigens, Uqcrc2; this response was detected in the draining lymph node and spleen. Antigen reactive cells were not detected in non-tumor bearing mice. The magnitude of the response to the Uqcrc2 neoantigen was similar to that of the strong influenza hemagglutinin antigen, a model tumor neoantigen. This work confirms that the approach of RNAseq plus peptide prediction and ELISPOT testing is sufficient to identify natural tumor neoantigens. PMID:26140232

  5. Naturally produced citral can significantly inhibit normal physiology and induce cytotoxicity on Magnaporthe grisea.

    PubMed

    Li, Rong-Yu; Wu, Xiao-Mao; Yin, Xian-Hui; Long, You-Hua; Li, Ming

    2015-02-01

    Given the importance of finding alternatives to synthetic fungicides, the antifungal effects of natural product citral on six plant pathogenic fungi (Magnaporthe grisea, Gibberella zeae, Fusarium oxysporum, Valsa mali, Botrytis cinerea, and Rhizoctonia solani) were determined. Mycelial growth rate results showed that citral possessed high antifungal activities on those test fungi with EC50 values ranging from 39.52 to 193.00 µg/mL, which had the highest inhibition rates against M. grisea. Further action mechanism of citral on M. grisea was carried out. Citral treatment was found to alter the morphology of M. grisea hyphae by causing a loss of cytoplasm and distortion of mycelia. Moreover, citral was able to induce an increase in chitinase activity in M. grisea, indicating disruption of the cell wall. These results indicate that citral may act by disrupting cell wall integrity and membrane permeability, thus resulting in physiology changes and causing cytotoxicity. Importantly, the inhibitory effect of citral on M. grisea appears to be associated with its effects on mycelia reducing sugar, soluble protein, chitinase activity, pyruvate content, and malondialdehyde content. PMID:25752425

  6. The dependence of induced polarization on natural iron concentration in wetland soils

    NASA Astrophysics Data System (ADS)

    Slater, L. D.; Mansoor, N.

    2006-12-01

    Spectral Induced polarization (SIP) measurements in the frequency range 0.1-1000 Hz were conducted on clay and peat marsh soils, obtained from a contaminated freshwater weltand in New Jersey, that were subsequently analyzed for heavy metal concentrations, moisture content, organic matter, porosity, specific surface area, and pore fluid conductivity. A Cole-Cole relaxation model was fit to each of the samples and the model parameters analyzed in terms of the measured physiochemical properties. A linear relationship between the normalized chargeability (mn) and the estimated surface area to pore volume (Sp) is found when the iron content (ranging from 0.25 to 1.63 percent by volume between samples) is accounted for as a polarizable element of the soil. In fact, the dependence of mn on volumetric Fe concentration per unit volume of the bulk soil is described by a linear relationship with a correlation coefficient of 0.94. As the Fe concentration of soils is a critical biogeochemical parameter, these results suggest that SIP measurements may provide a hitherto unrecognized approach to probing soil geochemistry, iron cycling and anaerobic microbial activity. Furthermore, our results yield new insight into the physiochemical controls on SIP in natural, unconsolidated soils.

  7. Coding deficits in hidden hearing loss induced by noise: the nature and impacts.

    PubMed

    Song, Qiang; Shen, Pei; Li, Xiaowei; Shi, Lijuan; Liu, Lijie; Wang, Jiping; Yu, Zhiping; Stephen, Kegan; Aiken, Steve; Yin, Shankai; Wang, Jian

    2016-01-01

    Hidden hearing refers to the functional deficits in hearing without deterioration in hearing sensitivity. This concept is proposed based upon recent finding of massive noise-induced damage on ribbon synapse between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) in the cochlea without significant permanent threshold shifts (PTS). Presumably, such damage may cause coding deficits in auditory nerve fibers (ANFs). However, such deficits had not been detailed except that a selective loss of ANFs with low spontaneous rate (SR) was reported. In the present study, we investigated the dynamic changes of ribbon synapses and the coding function of ANF single units in one month after a brief noise exposure that caused a massive damage of ribbon synapses but no PTS. The synapse count and functional response measures indicates a large portion of the disrupted synapses were re-connected. This is consistent with the fact that the change of SR distribution due to the initial loss of low SR units is recovered quickly. However, ANF coding deficits were developed later with the re-establishment of the synapses. The deficits were found in both intensity and temporal processing, revealing the nature of synaptopathy in hidden hearing loss. PMID:27117978

  8. Tear energy and strain-induced crystallization of natural rubber/styrene-butadiene rubber blend

    NASA Astrophysics Data System (ADS)

    Noguchi, F.; Akabori, K.; Yamamoto, Y.; Kawazura, T.; Kawahara, S.

    2009-08-01

    Strain-induced crystallization of natural rubber (NR), dispersed in styrene-butadiene rubber (SBR), was investigated in relation to dimensional feature of a dispersoid and crosslink density of NR by measuring tear energy (G) of crosslinked NR/SBR blends. The crosslinked NR/SBR blends in ratios of 1/9 and 3/7 by weight were prepared by mixing masticated NR and SBR with an internal mixer at a rotor speed of 30 rpm, followed by crosslinking with dicumyl peroxide on a hot press at 444 K for 60 min. The G, measured in wide-ranges of temperature and tear rate, was superposed into a master curve with a Williams-Landel-Ferry shift factor. The G of the NR/SBR(3/7) blend abruptly decreased to a level comparable to that of SBR at about melting temperature of NR crystals formed on straining. The temperature, at which the dramatic decrease in the G occurred, was associated with the dimensional feature of the NR dispersoid and the crosslink density.

  9. Coding deficits in hidden hearing loss induced by noise: the nature and impacts

    PubMed Central

    Song, Qiang; Shen, Pei; Li, Xiaowei; Shi, Lijuan; Liu, Lijie; Wang, Jiping; Yu, Zhiping; Stephen, Kegan; Aiken, Steve; Yin, Shankai; Wang, Jian

    2016-01-01

    Hidden hearing refers to the functional deficits in hearing without deterioration in hearing sensitivity. This concept is proposed based upon recent finding of massive noise-induced damage on ribbon synapse between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) in the cochlea without significant permanent threshold shifts (PTS). Presumably, such damage may cause coding deficits in auditory nerve fibers (ANFs). However, such deficits had not been detailed except that a selective loss of ANFs with low spontaneous rate (SR) was reported. In the present study, we investigated the dynamic changes of ribbon synapses and the coding function of ANF single units in one month after a brief noise exposure that caused a massive damage of ribbon synapses but no PTS. The synapse count and functional response measures indicates a large portion of the disrupted synapses were re-connected. This is consistent with the fact that the change of SR distribution due to the initial loss of low SR units is recovered quickly. However, ANF coding deficits were developed later with the re-establishment of the synapses. The deficits were found in both intensity and temporal processing, revealing the nature of synaptopathy in hidden hearing loss. PMID:27117978

  10. Enhanced mixing of a rectangular supersonic jet by natural and induced screech

    NASA Technical Reports Server (NTRS)

    Rice, Edward J.; Raman, Ganesh

    1993-01-01

    The influence of shear layer excitation on the mixing of supersonic rectangular jets was studied experimentally. Two methods of excitation were used to control the jet mixing. The first used the natural screech of an underexpanded supersonic jet from a converging nozzle. The level of the screech excitation was controlled by the use of a pair of baffles located to block the acoustic feedback path between the downstream shock structure and the nozzle lip. A screech level variation of over 30 decibels was achieved and the mixing was completely determined by the level of screech attained at the nozzle lip. The second form of self-excitation used the induced screech caused by obstacles or paddles located in the shear layers on either long side of the rectangular jet. With sufficient immersion of the paddles intense jet mixing occurred and large flapping wave motion was observed using a strobed focused Schlieren system. Each paddle was instrumented with a total pressure tap and strain gages to determine the pressure and drag force on the square cross-section paddle. Considerable drag was observed in this initial exploratory study. Future studies using alternate paddle geometries will be conducted to maximize jet mixing with minimum drag.

  11. Investigation of activation cross-sections of alpha-induced nuclear reactions on natural cadmium

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Kim, Kwangsoo; Lee, Manwoo; Kim, Guinyun

    2014-08-01

    We measured production cross-sections of Sn, In, and Cd radionuclides from alpha-induced reactions on natCd from their respective threshold to 45 MeV by using a stacked-foil activation technique at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the earlier measurements as well as with the theoretical values obtained from the TENDL-2012 library based on the TALYS 1.4 code. Our measurements for the 110,113g,117mSn, 108m,108g,109g,110m,110g,111g,113m,114m,115m,116m,117m,117gIn, and 111m,115gCd radionuclides in the energy region from the threshold energy to 45 MeV are in general good agreement with the other experimental data and calculated results. The integral yields for thick target were also deduced using the measured cross-sections and the stopping power of natural cadmium target and found in agreement with the directly measured yields available in the literature. The measured cross-sections find importance in various practical applications including nuclear medicine and improvement of nuclear model calculations.

  12. Citrus aurantium increases seizure latency to PTZ induced seizures in zebrafish thru NMDA and mGluR's I and II.

    PubMed

    Rosa-Falero, Coral; Torres-Rodríguez, Stephanie; Jordán, Claudia; Licier, Rígel; Santiago, Yolimar; Toledo, Zuleyma; Santiago, Marely; Serrano, Kiara; Sosa, Jeffrey; Ortiz, José G

    2014-01-01

    Epilepsy is a serious neurological condition and pharmacotherapy is not effective for all patients and causes serious adverse effects and pharmacokinetic and pharmacodynamic interactions. Natural products and ethnobotanical resources can help develop new therapeutic options for conditions like epilepsy. In Puerto Rico, ethnobotanical resources highlight the anxiolytic properties of a tea like preparation made from the leaves of the Citrus aurantium tree or bitter orange. Studies performed with essential oils from the peel of the fruit have shown to increase seizure latency to pentylenetetrazole (PTZ) and maximal electroshock seizure in mice. We characterized the extract composition, and used a model of PTZ induces seizures in the zebrafish and a receptor-ligand binding assay to determine if this preparation has anticonvulsant properties and its mechanism of action. We determined that the aqueous extract made from the leaves of the C. aurantium tree contains hesperidin, neohesperidin, and neohesperidin dihydrochalcone. Using our zebrafish model, we determined that exposure to the C. aurantium 28 mg/mL extract in aquarium water increases seizure latency by 119% compared to controls. We ruled out a mechanism involving GABAA receptors using the selective antagonist gabazine. We used two approaches to study the role of glutamate in the mechanism of the C. aurantium extract. The ligand binding assay revealed C. aurantium extracts at concentrations of 0.42 to 5.6 mg/mL significantly reduced [(3)H]Glu binding indicating an interaction with glutamate receptors, in particular with NMDA receptors and mGluR II. This interaction was confirmed with our animal model using selective receptor antagonists and we identified an interaction with mGluR I, not observed in the ligand binding experiment. These study provide evidence of the anticonvulsant properties of the aqueous extract made from the leaves of the C. aurantium tree and a mechanism involving NMDA and mGluR's I and II. PMID

  13. Citrus aurantium increases seizure latency to PTZ induced seizures in zebrafish thru NMDA and mGluR's I and II

    PubMed Central

    Rosa-Falero, Coral; Torres-Rodríguez, Stephanie; Jordán, Claudia; Licier, Rígel; Santiago, Yolimar; Toledo, Zuleyma; Santiago, Marely; Serrano, Kiara; Sosa, Jeffrey; Ortiz, José G.

    2015-01-01

    Epilepsy is a serious neurological condition and pharmacotherapy is not effective for all patients and causes serious adverse effects and pharmacokinetic and pharmacodynamic interactions. Natural products and ethnobotanical resources can help develop new therapeutic options for conditions like epilepsy. In Puerto Rico, ethnobotanical resources highlight the anxiolytic properties of a tea like preparation made from the leaves of the Citrus aurantium tree or bitter orange. Studies performed with essential oils from the peel of the fruit have shown to increase seizure latency to pentylenetetrazole (PTZ) and maximal electroshock seizure in mice. We characterized the extract composition, and used a model of PTZ induces seizures in the zebrafish and a receptor-ligand binding assay to determine if this preparation has anticonvulsant properties and its mechanism of action. We determined that the aqueous extract made from the leaves of the C. aurantium tree contains hesperidin, neohesperidin, and neohesperidin dihydrochalcone. Using our zebrafish model, we determined that exposure to the C. aurantium 28 mg/mL extract in aquarium water increases seizure latency by 119% compared to controls. We ruled out a mechanism involving GABAA receptors using the selective antagonist gabazine. We used two approaches to study the role of glutamate in the mechanism of the C. aurantium extract. The ligand binding assay revealed C. aurantium extracts at concentrations of 0.42 to 5.6 mg/mL significantly reduced [3H]Glu binding indicating an interaction with glutamate receptors, in particular with NMDA receptors and mGluR II. This interaction was confirmed with our animal model using selective receptor antagonists and we identified an interaction with mGluR I, not observed in the ligand binding experiment. These study provide evidence of the anticonvulsant properties of the aqueous extract made from the leaves of the C. aurantium tree and a mechanism involving NMDA and mGluR's I and II. PMID

  14. Diindolylmethane, a naturally occurring compound, induces CYP3A4 and MDR1 gene expression by activating human PXR

    PubMed Central

    Pondugula, Satyanarayana R.; Flannery, Patrick C.; Abbott, Kodye L.; Coleman, Elaine S.; Mani, Sridhar; Samuel, Temesgen; Xie, Wen

    2015-01-01

    Activation of human pregnane X receptor (hPXR)-regulated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1) plays an important role in mediating adverse drug interactions. Given the common use of natural products as part of adjunct human health behavior, there is a growing concern about natural products for their potential to induce undesired drug interactions through the activation of hPXR-regulated CYP3A4 and MDR1. Here, we studied whether 3,3′-diindolylmethane (DIM), a natural health supplement, could induce hPXR-mediated regulation of CYP3A4 and MDR1 in human hepatocytes and intestinal cells. DIM, at its physiologically relevant concentrations, not only induced hPXR transactivation of CYP3A4 promoter activity but also induced gene expression of CYP3A4 and MDR1. DIM decreased intracellular accumulation of MDR1 substrate rhodamine 123, suggesting that DIM induces the functional expression of MDR1. Pharmacologic inhibition or genetic knockdown of hPXR resulted in attenuation of DIM induced CYP3A4 and MDR1 gene expression, suggesting that DIM induces CYP3A4 and MDR1 in an hPXR-dependent manner. Together, these results support our conclusion that DIM induces hPXR-regulated CYP3A4 and MDR1 gene expression. The inductive effects of DIM on CYP3A4 and MDR1 expression caution the use of DIM in conjunction with other medications metabolized and transported via CYP3A4 and MDR1, respectively. PMID:25542144

  15. EFFECTS OF MANGANESE, CALCIUM, MAGNESIUM, AND ZINC ON NICKEL-INDUCED SUPPRESSION OF MURINE NATURAL KILLER CELL ACTIVITY

    EPA Science Inventory

    The effects that divalent metals have on nickel-induced suppression of natural killer (NK) cell activity were studied in mice. Male CBA/J mice were given a single intramuscular injection of nickel chloride (4.5-36 micrograms NiCl2/g), manganese chloride (20-80 micrograms MnCl2/g)...

  16. The Natural History of Acute Recovery of Blast-Induced Mild Traumatic Brain Injury: A Case Series During War.

    PubMed

    Larres, David T; Carr, Walter; Gonzales, Elizandro G; Hawley, Jason S

    2016-05-01

    Traumatic brain injury (TBI) secondary to blast exposure is a common injury in the Global War on Terrorism, but little is known about the acute effects, recovery, pathophysiology, and neuropathology of blast-induced mild TBI (mTBI) in humans in a battlefield environment. Moreover, there is ongoing debate whether blast-induced mTBI is a different injury with a unique pathophysiology compared with mTBI from blunt trauma. In the case series reported here from Craig Joint Theater Hospital at Bagram Airfield, Afghanistan, 15 military service members with acute concussion/mTBI associated with blast exposure were evaluated within the first 24 hours after concussion and on days 2, 3, 5, and 7 with a Graded Symptom Checklist and a balance assessment, the Balance Error Scoring System. These data suggest that the recovery in blast-induced mTBI follows the pattern of recovery in sports-related concussion reported in The National Collegiate Athletic Association Concussion Study. In this retrospective case series, we provide the first description of the natural history of acute recovery in blast-induced mTBI, and we suspect, given our experience treating military service members, that further observations of the natural history of recovery in blast-induced mTBI will continue to mirror the natural history of recovery in sports concussion. PMID:27168549

  17. Effects of natural and human-induced hypoxia on coastal benthos

    NASA Astrophysics Data System (ADS)

    Levin, L. A.; Ekau, W.; Gooday, A. J.; Jorissen, F.; Middelburg, J. J.; Naqvi, S. W. A.; Neira, C.; Rabalais, N. N.; Zhang, J.

    2009-10-01

    Coastal hypoxia (defined here as <1.42 ml L-1; 62.5 μM; 2 mg L-1, approx. 30% oxygen saturation) develops seasonally in many estuaries, fjords, and along open coasts as a result of natural upwelling or from anthropogenic eutrophication induced by riverine nutrient inputs. Permanent hypoxia occurs naturally in some isolated seas and marine basins as well as in open slope oxygen minimum zones. Responses of benthos to hypoxia depend on the duration, predictability, and intensity of oxygen depletion and on whether H2S is formed. Under suboxic conditions, large mats of filamentous sulfide oxidizing bacteria cover the seabed and consume sulfide. They are hypothesized to provide a detoxified microhabitat for eukaryotic benthic communities. Calcareous foraminiferans and nematodes are particularly tolerant of low oxygen concentrations and may attain high densities and dominance, often in association with microbial mats. When oxygen is sufficient to support metazoans, small, soft-bodied invertebrates (typically annelids), often with short generation times and elaborate branchial structures, predominate. Large taxa are more sensitive than small taxa to hypoxia. Crustaceans and echinoderms are typically more sensitive to hypoxia, with lower oxygen thresholds, than annelids, sipunculans, molluscs and cnidarians. Mobile fish and shellfish will migrate away from low-oxygen areas. Within a species, early life stages may be more subject to oxygen stress than older life stages. Hypoxia alters both the structure and function of benthic communities, but effects may differ with regional hypoxia history. Human-caused hypoxia is generally linked to eutrophication, and occurs adjacent to watersheds with large populations or agricultural activities. Many occurrences are seasonal, within estuaries, fjords or enclosed seas of the North Atlantic and the NW Pacific Oceans. Benthic faunal responses, elicited at oxygen levels below 2 ml L-1, typically involve avoidance or mortality of large

  18. Scientific services related to climate-induced natural hazards in the Vrancea Seismic Region, Romania

    NASA Astrophysics Data System (ADS)

    Sima, M.; Micu, D.; Dragota, C.; Chendes, V.; Micu, M.; Balteanu, D.

    2012-04-01

    Scientific services, regarded as a tool for offering different stakeholders and users with the necessary information adapted to their needs, are a major challenge to researchers nowadays. The paper aims to present an example of user-researcher interaction on issues related to climate-induced hazards in a highly seismic region of Romania. It is a case-study included in the FP7 ECLISE project which has in view the assessment of landslide and floods hazard and risk, as being the most important climate-induced natural hazards in the region. The main climate signals derived from the observational data indicate a tendency of precipitation concentration over short time intervals and the increase of their torrential character, combined during spring with long-lasting rains and snowmelt which generally led to a higher instability of the slopes due to landslides and flash floods. The Vrancea Seismic Region, considered being the most active sub-crustal earthquake province of Europe, with 3-5 earthquakes over magnitude 7 per century, is represented by the Curvature sector of the Carpathians and Subcarpathians of Romania. The region is affected by a large diversity of slope processes (especially landslides and mudflows) and flood and flash-flood events, generated by the morphometric traits of the small catchments, the loose lithology, the torrential features of rainfalls especially during the summer and by the severe changes occurred in the land cover characteristics after 1989 (large deforestation, property fragmentation, lack of interest in land-management works). Based on a comprehensive landslide inventory, the landslide susceptibility map (showing the probability of occurrence in space), obtained through statistical analysis and field/statistically-validated, would be completed with the hazard assessment, resulting from the correlation of landslide frequency and magnitude, rainfall triggering threshold and its returning period. The numerous elements at risk (transport and

  19. The natural organosulfur compound dipropyltetrasulfide prevents HOCl-induced systemic sclerosis in the mouse

    PubMed Central

    2013-01-01

    Introduction The aim of this study was to test the naturally occurring organosulfur compound dipropyltetrasulfide (DPTTS), found in plants, which has antibiotic and anticancer properties, as a treatment for HOCl-induced systemic sclerosis in the mouse. Methods The prooxidative, antiproliferative, and cytotoxic effects of DPTTS were evaluated ex vivo on fibroblasts from normal and HOCl mice. In vivo, the antifibrotic and immunomodulating properties of DPTTS were evaluated in the skin and lungs of HOCl mice. Results H2O2 production was higher in fibroblasts derived from HOCl mice than in normal fibroblasts (P < 0.05). DPTTS did not increase H2O2 production in normal fibroblasts, but DPTTS dose-dependently increased H2O2 production in HOCl fibroblasts (P < 0.001 with 40 μM DPTTS). Because H2O2 reached a lethal threshold in cells from HOCl mice, the antiproliferative, cytotoxic, and proapoptotic effects of DPTTS were significantly higher in HOCl fibroblasts than for normal fibroblasts. In vivo, DPTTS decreased dermal thickness (P < 0.001), collagen content in skin (P < 0.01) and lungs (P < 0.05), αSMA (P < 0.01) and pSMAD2/3 (P < 0.01) expression in skin, formation of advanced oxidation protein products and anti-DNA topoisomerase-1 antibodies in serum (P < 0.05) versus untreated HOCl mice. Moreover, in HOCl mice, DPTTS reduced splenic B-cell counts (P < 0.01), the proliferative rates of B-splenocytes stimulated by lipopolysaccharide (P < 0.05), and T-splenocytes stimulated by anti-CD3/CD28 mAb (P < 0.001). Ex vivo, it also reduced the production of IL-4 and IL-13 by activated T cells (P < 0.05 in both cases). Conclusions The natural organosulfur compound DPTTS prevents skin and lung fibrosis in the mouse through the selective killing of diseased fibroblasts and its immunomodulating properties. DPTTS may be a potential treatment for systemic sclerosis. PMID:24286210

  20. Revving up Natural Killer Cells and Cytokine-Induced Killer Cells Against Hematological Malignancies.

    PubMed

    Pittari, Gianfranco; Filippini, Perla; Gentilcore, Giusy; Grivel, Jean-Charles; Rutella, Sergio

    2015-01-01

    Natural killer (NK) cells belong to innate immunity and exhibit cytolytic activity against infectious pathogens and tumor cells. NK-cell function is finely tuned by receptors that transduce inhibitory or activating signals, such as killer immunoglobulin-like receptors, NK Group 2 member D (NKG2D), NKG2A/CD94, NKp46, and others, and recognize both foreign and self-antigens expressed by NK-susceptible targets. Recent insights into NK-cell developmental intermediates have translated into a more accurate definition of culture conditions for the in vitro generation and propagation of human NK cells. In this respect, interleukin (IL)-15 and IL-21 are instrumental in driving NK-cell differentiation and maturation, and hold great promise for the design of optimal NK-cell culture protocols. Cytokine-induced killer (CIK) cells possess phenotypic and functional hallmarks of both T cells and NK cells. Similar to T cells, they express CD3 and are expandable in culture, while not requiring functional priming for in vivo activity, like NK cells. CIK cells may offer some advantages over other cell therapy products, including ease of in vitro propagation and no need for exogenous administration of IL-2 for in vivo priming. NK cells and CIK cells can be expanded using a variety of clinical-grade approaches, before their infusion into patients with cancer. Herein, we discuss GMP-compliant strategies to isolate and expand human NK and CIK cells for immunotherapy purposes, focusing on clinical trials of adoptive transfer to patients with hematological malignancies. PMID:26029215

  1. Structural and spectroscopic changes to natural nontronite induced by experimental impacts between 10 and 40 GPa

    NASA Astrophysics Data System (ADS)

    Friedlander, Lonia R.; Glotch, Timothy D.; Bish, David L.; Dyar, M. Darby; Sharp, Thomas G.; Sklute, Elizabeth C.; Michalski, Joseph R.

    2015-05-01

    Many phyllosilicate deposits remotely detected on Mars occur within bombarded terrains. Shock metamorphism from meteor impacts alters mineral structures, producing changed mineral spectra. Thus, impacts have likely affected the spectra of remotely sensed Martian phyllosilicates. We present spectral analysis results for a natural nontronite sample before and after laboratory-generated impacts over five peak pressures between 10 and 40 GPa. We conducted a suite of spectroscopic analyses to characterize the sample's impact-induced structural and spectral changes. Nontronite becomes increasingly disordered with increasing peak impact pressure. Every infrared spectroscopic technique used showed evidence of structural changes at shock pressures above ~25 GPa. Reflectance spectroscopy in the visible near-infrared region is primarily sensitive to the vibrations of metal-OH and interlayer H2O groups in the nontronite octahedral sheet. Midinfrared (MIR) spectroscopic techniques are sensitive to the vibrations of silicon and oxygen in the nontronite tetrahedral sheet. Because the tetrahedral and octahedral sheets of nontronite deform differently, impact-driven structural deformation may contribute to differences in phyllosilicate detection between remote sensing techniques sensitive to different parts of the nontronite structure. Observed spectroscopic changes also indicated that the sample's octahedral and tetrahedral sheets were structurally deformed but not completely dehydroxylated. This finding is an important distinction from previous studies of thermally altered phyllosilicates in which dehydroxylation follows dehydration in a stepwise progression preceding structural deformation. Impact alteration may thus complicate mineral-specific identifications based on the location of OH-group bands in remotely detected spectra. This is a key implication for Martian remote sensing arising from our results.

  2. Studying human respiratory disease in animals--role of induced and naturally occurring models.

    PubMed

    Williams, Kurt; Roman, Jesse

    2016-01-01

    Respiratory disorders like asthma, emphysema, and pulmonary fibrosis affect millions of Americans and many more worldwide. Despite advancements in medical research that have led to improved understanding of the pathophysiology of these conditions and sometimes to new therapeutic interventions, these disorders are for the most part chronic and progressive; current interventions are not curative and do not halt disease progression. A major obstacle to further advancements relates to the absence of animal models that exactly resemble the human condition, which delays the elucidation of relevant mechanisms of action, the unveiling of biomarkers of disease progression, and identification of new targets for intervention in patients. There are currently many induced animal models of human respiratory disease available for study, and even though they mimic features of human disease, discoveries in these models have not always translated into safe and effective treatments in humans. A major obstacle relates to the genetic, anatomical, and functional variations amongst species, which represents the major challenge to overcome when searching for appropriate models of respiratory disease. Nevertheless, rodents, in particular mice, have become the most common species used for experimentation, due to their relatively low cost, size, and adequate understanding of murine genetics, among other advantages. Less well known is the fact that domestic animals also suffer from respiratory illnesses similar to those found in humans. Asthma, bronchitis, pneumonia, and pulmonary fibrosis are among the many disorders occurring naturally in dogs, cats, and horses, among other species. These models might better resemble the human condition and are emphasized here, but further investigations are needed to determine their relevance. PMID:26467890

  3. A Novel Natural Product, KL-21, Inhibits Proliferation and Induces Apoptosis in Chronic Lymphocytic Leukemia Cells

    PubMed Central

    Adan Gökbulut, Aysun; Yaşar, Mustafa; Baran, Yusuf

    2015-01-01

    Objective: The aims of this study were to examine the cytotoxic and apoptotic effects of KL-21, a novel plant product (produced by Naturin Natural Products, İzmir, Turkey), on 232B4 chronic lymphocytic leukemia (CLL) cells and to determine the cytotoxic effects on healthy BEAS-2B human bronchial epithelial cells. Materials and Methods: The cytotoxic effect of KL-21 was determined by MTT cell proliferation assay. Changes in caspase-3 enzyme activity were measured using the caspase-3 colorimetric assay. Changes in mitochondrial membrane potential were determined using the JC-1 dye-based method. Annexin V-FITC/PI double staining was performed to measure the apoptotic cell population. Effects of KL-21 on cell cycle profiles of CLL cells were investigated by flow cytometry. Results: We detected time- and concentration-dependent increases in the cytotoxic effect of KL-21 on 232B4 CLL cells. However, we also showed that, especially at higher concentrations, KL-21 was less cytotoxic towards BEAS-2B healthy cells than towards CLL cells. Annexin-V/PI double staining results showed that the apoptotic cell population increased in 232B4 cells. Increasing concentrations of KL-21 increased caspase-3 enzyme activity and induced loss of mitochondrial membrane potential. KL-21 administration resulted in small increases in the percentage of the cells in the G0/G1 phase while it decreased the S phase cell population up to 1 mg/mL. At the highest concentration, most of the cells accumulated in the G0/G1 phase. Conclusion: KL-21 has a growth-inhibitory effect on 232B4 CLL cells. KL-21 causes apoptosis and cell cycle arrest at G0/G1. PMID:26316479

  4. Evaluation of role of natural killer cells in radiation-induced leukemogenesis in mice

    SciTech Connect

    Gorelik, E.; Rosen, B.; Copeland, D.; Weatherly, B.; Herberman, R.B.

    1984-06-01

    The relationship of the leukemogenic and natural killer (NK)-suppressive effects of fractionated doses of gamma-radiation in mice was studied. A/J mice were relatively resistant; CBA/J, BALB/c, and C57BL/6 were susceptible to both the NK-suppressive and leukemogenic effects, and young (1 mo old) C57BL/6 mice were more susceptible than were 2- and 3-month-old C57BL/6 mice to both effects. Age-dependent susceptibility to radiation-induced leukemogenesis also was observed in C57BL/6 (bg/bg) (beige) mice. No differences in incidence and latent period of lymphoma development were found between C57BL/6 (+/+) and beige mice. Bone marrow cells (BMC) from normal C57BL/6 donors reconstituted the NK reactivity of irradiated C57BL/6 (+/+) or beige recipients and inhibited leukemogenesis. Although BMC of beige donors did not reconstitute the NK reactivity of irradiated C57BL/6 (+/+) or beige recipients, these cells were as efficient for antileukemic protection as were BMC from C57BL/6 (+/+) mice. The bone marrow of irradiated mice contained preleukemia cells that produced leukemias when transplanted iv into recipients preirradiated with 400 R. Inoculation (iv) of spleen cells (SpC) from syngeneic nude mice plus preleukemia bone marrow cells (PBMC) were able to inhibit leukemia formation in the 400 R-irradiated recipients. SpC from beige mice, normal C57BL/6 (+/+) mice, or C57BL/6 (+/+) mice treated with anti-asialo GM1 serum had no influence on the development of leukemia after their transplantation with PBMC.

  5. Revving up Natural Killer Cells and Cytokine-Induced Killer Cells Against Hematological Malignancies

    PubMed Central

    Pittari, Gianfranco; Filippini, Perla; Gentilcore, Giusy; Grivel, Jean-Charles; Rutella, Sergio

    2015-01-01

    Natural killer (NK) cells belong to innate immunity and exhibit cytolytic activity against infectious pathogens and tumor cells. NK-cell function is finely tuned by receptors that transduce inhibitory or activating signals, such as killer immunoglobulin-like receptors, NK Group 2 member D (NKG2D), NKG2A/CD94, NKp46, and others, and recognize both foreign and self-antigens expressed by NK-susceptible targets. Recent insights into NK-cell developmental intermediates have translated into a more accurate definition of culture conditions for the in vitro generation and propagation of human NK cells. In this respect, interleukin (IL)-15 and IL-21 are instrumental in driving NK-cell differentiation and maturation, and hold great promise for the design of optimal NK-cell culture protocols. Cytokine-induced killer (CIK) cells possess phenotypic and functional hallmarks of both T cells and NK cells. Similar to T cells, they express CD3 and are expandable in culture, while not requiring functional priming for in vivo activity, like NK cells. CIK cells may offer some advantages over other cell therapy products, including ease of in vitro propagation and no need for exogenous administration of IL-2 for in vivo priming. NK cells and CIK cells can be expanded using a variety of clinical-grade approaches, before their infusion into patients with cancer. Herein, we discuss GMP-compliant strategies to isolate and expand human NK and CIK cells for immunotherapy purposes, focusing on clinical trials of adoptive transfer to patients with hematological malignancies. PMID:26029215

  6. Leishmanicidal and cytotoxic activities of extracts and naturally-occurring compounds from two Lauraceae species.

    PubMed

    Sánchez-Suárez, Jeysson; Coy-Barrera, Ericsson; Cuca, Luis Enrique; Delgado, Gabriela

    2011-02-01

    The in vitro leishmanicidal effects of ethanolic extracts and fifteen naturally-occurring compounds (five lignans, eight neolignans, a diterpene and a dihydrochalcone), obtained from Pleurothyrium cinereum and Ocotea macrophylla, were evaluated on promastigotes of Leishmania panamensis and L. braziliensis. In addition, in order to determine the selective action on Leishmania species as a safety principle, in vitro cytotoxicity on J774 cells was also evaluated for test compounds and extracts. One extract and seven compounds showed activity against Leishmania parasites at different levels. Dihydroflavokawin B (8) was found to be the most potent antileishmanial compound on both parasites, whilst (+)-otobaphenol (14), was found to be the most selective compound on L. panamensis. PMID:21425681

  7. A quantitative analysis of microbially-induced calcite precipitation employing artificial and naturally-occurring sediments

    NASA Astrophysics Data System (ADS)

    Lokier, Stephen; Krieg Dosier, Ginger

    2013-04-01

    Microbially-induced calcite precipitation is a strong candidate for the production of sustainable construction materials. The process employs the microbe Sporosarcina pasteurii as an agent to microbially mediate the precipitation of calcium carbonate to bind unconsolidated sediment. As this process can be achieved under ambient temperature conditions and can utilise a wide variety of easily-available sediments, potentially including waste materials, it is envisioned that this procedure could significantly reduce carbon-dioxide emissions in the construction industry. This study describes and quantifies the precipitation of calcite cement in a range of naturally-occurring sediments compared with a control matrix. The study establishes the optimum treatment time for effective cement precipitation in order to produce a material that meets the standards required for construction whilst keeping economic and environmental outlays at a minimum. The 'control sediment' employed industrial-grade glass beads with a grain size range of 595-1180 microns (16-30 US mesh). Sporosarcina pasteurii were mixed in a solution of urea and calcium chloride and then inoculated into the control sediment. The microbes attach to the surface of the sediment grains and employ urea as a source of energy to produce ammonia and carbon dioxide. By so doing, they increase the pH of the solution allowing calcium carbonate to precipitate at the cell walls to act as nucleation points facilitating the precipitation of cements as a grain-coating and biocementing the unconsolidated sediment. The solution treatment was repeated at eight hour intervals with samples removed for detailed analysis after each every five consecutive treatments (i.e. 40 hours). The process was repeated to produce 20 samples with treatment times between 40 and 800 hours. Cemented samples were impregnated with blue epoxy and examined petrographically to monitor cement development. Modal analysis was undertaken on each cemented

  8. Reduced Tyk2 gene expression in β-cells due to natural mutation determines susceptibility to virus-induced diabetes.

    PubMed

    Izumi, Kenichi; Mine, Keiichiro; Inoue, Yoshitaka; Teshima, Miho; Ogawa, Shuichiro; Kai, Yuji; Kurafuji, Toshinobu; Hirakawa, Kanako; Miyakawa, Daiki; Ikeda, Haruka; Inada, Akari; Hara, Manami; Yamada, Hisakata; Akashi, Koichi; Niho, Yoshiyuki; Ina, Keisuke; Kobayashi, Takashi; Yoshikai, Yasunobu; Anzai, Keizo; Yamashita, Teruo; Minagawa, Hiroko; Fujimoto, Shuji; Kurisaki, Hironori; Shimoda, Kazuya; Katsuta, Hitoshi; Nagafuchi, Seiho

    2015-01-01

    Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic β-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by β-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic β-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes. PMID:25849081

  9. Reduced Tyk2 gene expression in β-cells due to natural mutation determines susceptibility to virus-induced diabetes

    PubMed Central

    Izumi, Kenichi; Mine, Keiichiro; Inoue, Yoshitaka; Teshima, Miho; Ogawa, Shuichiro; Kai, Yuji; Kurafuji, Toshinobu; Hirakawa, Kanako; Miyakawa, Daiki; Ikeda, Haruka; Inada, Akari; Hara, Manami; Yamada, Hisakata; Akashi, Koichi; Niho, Yoshiyuki; Ina, Keisuke; Kobayashi, Takashi; Yoshikai, Yasunobu; Anzai, Keizo; Yamashita, Teruo; Minagawa, Hiroko; Fujimoto, Shuji; Kurisaki, Hironori; Shimoda, Kazuya; Katsuta, Hitoshi; Nagafuchi, Seiho

    2015-01-01

    Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic β-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by β-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic β-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes. PMID:25849081

  10. 2016 One-Year Seismic Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes

    USGS Publications Warehouse

    Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2016-01-01

    The U.S. Geological Survey (USGS) has produced a 1-year seismic hazard forecast for 2016 for the Central and Eastern United States (CEUS) that includes contributions from both induced and natural earthquakes. The model assumes that earthquake rates calculated from several different time windows will remain relatively stationary and can be used to forecast earthquake hazard and damage intensity for the year 2016. This assessment is the first step in developing an operational earthquake forecast for the CEUS, and the analysis could be revised with updated seismicity and model parameters. Consensus input models consider alternative earthquake catalog durations, smoothing parameters, maximum magnitudes, and ground motion estimates, and represent uncertainties in earthquake occurrence and diversity of opinion in the science community. Ground shaking seismic hazard for 1-percent probability of exceedance in 1 year reaches 0.6 g (as a fraction of standard gravity [g]) in northern Oklahoma and southern Kansas, and about 0.2 g in the Raton Basin of Colorado and New Mexico, in central Arkansas, and in north-central Texas near Dallas. Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NHSM) by more than a factor of 3; the 2014 NHSM did not consider induced earthquakes. In some areas, previously observed induced earthquakes have stopped, so the seismic hazard reverts back to the 2014 NSHM. Increased seismic activity, whether defined as induced or natural, produces high hazard. Conversion of ground shaking to seismic intensity indicates that some places in Oklahoma, Kansas, Colorado, New Mexico, Texas, and Arkansas may experience damage if the induced seismicity continues unabated. The chance of having Modified Mercalli Intensity (MMI) VI or greater (damaging earthquake shaking) is 5–12 percent per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes

  11. 2016 one-year seismic hazard forecast for the Central and Eastern United States from induced and natural earthquakes

    USGS Publications Warehouse

    Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2016-01-01

    The U.S. Geological Survey (USGS) has produced a 1-year seismic hazard forecast for 2016 for the Central and Eastern United States (CEUS) that includes contributions from both induced and natural earthquakes. The model assumes that earthquake rates calculated from several different time windows will remain relatively stationary and can be used to forecast earthquake hazard and damage intensity for the year 2016. This assessment is the first step in developing an operational earthquake forecast for the CEUS, and the analysis could be revised with updated seismicity and model parameters. Consensus input models consider alternative earthquake catalog durations, smoothing parameters, maximum magnitudes, and ground motion estimates, and represent uncertainties in earthquake occurrence and diversity of opinion in the science community. Ground shaking seismic hazard for 1-percent probability of exceedance in 1 year reaches 0.6 g (as a fraction of standard gravity [g]) in northern Oklahoma and southern Kansas, and about 0.2 g in the Raton Basin of Colorado and New Mexico, in central Arkansas, and in north-central Texas near Dallas. Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NHSM) by more than a factor of 3; the 2014 NHSM did not consider induced earthquakes. In some areas, previously observed induced earthquakes have stopped, so the seismic hazard reverts back to the 2014 NSHM. Increased seismic activity, whether defined as induced or natural, produces high hazard. Conversion of ground shaking to seismic intensity indicates that some places in Oklahoma, Kansas, Colorado, New Mexico, Texas, and Arkansas may experience damage if the induced seismicity continues unabated. The chance of having Modified Mercalli Intensity (MMI) VI or greater (damaging earthquake shaking) is 5–12 percent per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes

  12. The Illusion of the Positive: The impact of natural and induced mood on older adults’ false recall

    PubMed Central

    Emery, Lisa; Hess, Thomas M.; Elliot, Tonya

    2012-01-01

    Recent research suggests that affective and motivational processes can influence age differences in memory. In the current study, we examine the impact of both natural and induced mood state on age differences in false recall. Older and younger adults performed a version of the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995) false memory paradigm in either their natural mood state or after a positive or negative mood induction. Results indicated that, after accounting for age differences in basic cognitive function, age-related differences in positive mood during the testing session were related to increased false recall in older adults. Inducing older adults into a positive mood also exacerbated age differences in false memory. In contrast, veridical recall did not appear to be systematically influenced by mood. Together, these results suggest that positive mood states can impact older adults’ information processing and potentially increase underlying cognitive age differences. PMID:22292431

  13. Impacts of natural and human-induced disturbances on carbon dynamics in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Shvidenko, A.; Shchepashchenko, D.

    2012-12-01

    Disturbance regimes (DR) of vegetation ecosystems of Northern Eurasia (NE, limited to Russian territories) are represented by complicated and interacting sets of natural and human-induced disturbances (D). We present a unified classification of D and DR in major land cover classes of Northern Eurasia (forests, agriculture, wetlands, shrubs & grasses), their connections to succession regularities, and minimal informative set of indicators, which are able to describe both specifics of individual types of D and their impacts on annual carbon budget. The assessment of extent, severity and consequences of D was done based on an Integrated Land Information System for Russia, which accumulated all relevant spatially distributed information including multi-sensor and multi-temporal remote sensing concept, in situ measurements and ground data from diverse inventories and surveys. Major emissions caused by D are produced by consumption of plant products (agriculture and forestry), wild fire, and biotic D (basically insect outbreaks). For example, the annual flux due to human consumption of plant products is estimated at 170 Tg C yr-1. Wild fire in 1998-2010 enveloped 106.9 x 106 ha-1, on average 8.23 x 106 ha-1 yr-1, with variation from 4.2 to 17.3 x 106 ha-1 yr-1. Average direct carbon emissions due to wildfire were estimated to be at 121.0 Tg C yr-1, including 84.6% as C-CO2, 8.2% C-CO, C-CH4 - 1.1%, C-NMHC - 1.2%, organic carbon - 1.2% and black carbon - 0.1%, particulate matter 3.5%, of which PM2.5 - 1.2%. About 2/3 of burnt area and carbon emissions were on forest land. While the area of fire on wetlands was only 7.3%, this land class delivered 15.2% of the total fire emissions. Emissions caused by biotic D (accounted for forests only) is estimated at 50.8 Tg C yr-1. Overall, direct emissions due to D amounted at about 350 Tg C yr-1, or ~7% of annual Net Primary Production of terrestrial ecosystems of Russia. These data do not include long-term consequences of D, which

  14. The influence of age and genetics on natural resistance to experimentally induced feline infectious peritonitis.

    PubMed

    Pedersen, Niels C; Liu, Hongwei; Gandolfi, Barbara; Lyons, Leslie A

    2014-11-15

    Naturally occurring feline infectious peritonitis (FIP) is usually fatal, giving the impression that immunity to the FIP virus (FIPV) is extremely poor. This impression may be incorrect, because not all cats experimentally exposed to FIPV develop FIP. There is also a belief that the incidence of FIP may be affected by a number of host, virus, and environmental cofactors. However, the contribution of these cofactors to immunity and disease incidence has not been determined. The present study followed 111 random-bred specific pathogen free (SPF) cats that were obtained from a single research breeding colony and experimentally infected with FIPV. The cats were from several studies conducted over the past 5 years, and as a result, some of them had prior exposure to feline enteric coronavirus (FECV) or avirulent FIPVs. The cats were housed under optimized conditions of nutrition, husbandry, and quarantine to eliminate most of the cofactors implicated in FIPV infection outcome and were uniformly challenge exposed to the same field strain of serotype 1 FIPV. Forty of the 111 (36%) cats survived their initial challenge exposure to a Type I cat-passaged field strains of FIPV. Six of these 40 survivors succumbed to FIP to a second or third challenge exposure, suggesting that immunity was not always sustained. Exposure to non-FIP-inducing feline coronaviruses prior to challenge with virulent FIPV did not significantly affect FIP incidence but did accelerate the disease course in some cats. There were no significant differences in FIP incidence between males and females, but resistance increased significantly between 6 months and 1 or more years of age. Genetic testing was done on 107 of the 111 infected cats. Multidimensional scaling (MDS) segregated the 107 cats into three distinct families based primarily on a common sire(s), and resistant and susceptible cats were equally distributed within each family. Genome-wide association studies (GWAS) on 73 cats that died of FIP

  15. Tumour-Associated Transplantation Antigens of Neoplasms Induced by a Naturally Occurring Murine Sarcoma Virus (FBJ-MSV)

    PubMed Central

    Jones, David B.; Moore, Michael

    1973-01-01

    FBJ osteosarcoma virus (FBJ-MSV) isolated originally from a spontaneously arising osteosarcoma in a CF1 mouse is the only known naturally occurring murine sarcoma virus (MSV). It is unique among strains of MSV in producing primarily sarcomata in mice. The capacity of tumour cells transformed in vivo by this agent to elicit specific transplantation immunity in syngeneic hosts was investigated. A low level of resistance (104-105 cells) was consistently induced by implantation of x-irradiated (15,000 rad) tumours or surgical excision of developing subcutaneous grafts. By contrast intraperitoneal inoculation of virus containing cellfree extracts of FBJ-MSV sarcomata was a far less effective immunization procedure. Confirmatory evidence for the antigenicity of these neoplasms was obtained in tests in which preincubation of tumour cells with lymphoid cells from specifically immune donors inhibited in vivo outgrowth of the FBJ-MSV cells in untreated syngeneic recipients. The induction of host resistance to FBJ-MSV cells by immunization with identical and independently-induced FBJ-MSV tumours established that FBJ-MSV cells possess common cell surface antigenic specificities in a manner analogous to those of experimental neoplasms induced by other oncogenic DNA and RNA viruses. Since FBJ-MSV cells release infectious virus it was not possible in this system to establish whether the tumour-rejection antigen was cellular or virion in nature. The antigenic weakness of FBJ-MSV cells in syngeneic hosts is comparable with that of virus-induced murine leukaemias of the Gross (G) or “wild” type subgroup to which category FBJ-MSV also belongs. These features suggest that FBJ-MSV exemplifies naturally occurring sarcomagenic viruses more closely than those of the Friend-Moloney-Rauscher-Graffi (FMRGr) subgroup which in general induce highly antigenic neoplasms. PMID:4516007

  16. Acute, lethal, natural killer cell-resistant myeloproliferative disease induced by polyomavirus in severe combined immunodeficient mice.

    PubMed Central

    Szomolanyi-Tsuda, E.; Dundon, P. L.; Joris, I.; Shultz, L. D.; Woda, B. A.; Welsh, R. M.

    1994-01-01

    Infection of severe combined immunodeficient mice, which lack T and B lymphocytes, with polyomavirus (PyV) induced an acute hematological disorder leading to the death of the mice by 2 weeks postinfection. The disease was characterized by a dramatic decrease in megakaryocytes, multiple hemorrhages, anemia, thrombocytopenia, splenomegaly, a massive myeloproliferation and splenic erythroproliferation with a defect in maturation of the myeloid elements similar to that in acute leukemia. This pathology in severe combined immunodeficient mice is very different from that of the well-characterized tumor profiles induced by PyV in normal newborn or nude mice. Viral T and capsid (VP1) antigens and viral genome were detected in some cells in the spleen, but not in the majority of the proliferating myeloid cells. This suggests that the myeloproliferation is induced by some indirect mechanism, such as secretion of growth factors or cytokines by virus-infected cells, rather than by direct transformation by PyV. Neither the spread of PyV, its replication in different organs, nor the pathogenesis or the time of death were altered by depleting natural killer cells in vivo by anti-natural killer cell antibodies. Analysis of the spleen leukocyte population indicated that the cells expressed high levels of class I major histocompatibility complex antigens and were resistant to lysis by activated natural killer cells. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:8311119

  17. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    SciTech Connect

    Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

    2011-09-22

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

  18. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    NASA Astrophysics Data System (ADS)

    Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

    2011-09-01

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

  19. Leukemia-induced phenotypic and functional defects in natural killer cells predict failure to achieve remission in acute myeloid leukemia.

    PubMed

    Stringaris, Kate; Sekine, Takuya; Khoder, Ahmad; Alsuliman, Abdullah; Razzaghi, Bonnie; Sargeant, Ruhena; Pavlu, Jiri; Brisley, Gill; de Lavallade, Hugues; Sarvaria, Anushruthi; Marin, David; Mielke, Stephan; Apperley, Jane F; Shpall, Elizabeth J; Barrett, A John; Rezvani, Katayoun

    2014-05-01

    The majority of patients with acute myeloid leukemia will relapse, and older patients often fail to achieve remission with induction chemotherapy. We explored the possibility that leukemic suppression of innate immunity might contribute to treatment failure. Natural killer cell phenotype and function was measured in 32 consecutive acute myeloid leukemia patients at presentation, including 12 achieving complete remission. Compared to 15 healthy age-matched controls, natural killer cells from acute myeloid leukemia patients were abnormal at presentation, with downregulation of the activating receptor NKp46 (P=0.007) and upregulation of the inhibitory receptor NKG2A (P=0.04). Natural killer cells from acute myeloid leukemia patients had impaired effector function against autologous blasts and K562 targets, with significantly reduced CD107a degranulation, TNF-α and IFN-γ production. Failure to achieve remission was associated with NKG2A overexpression and reduced TNF-α production. These phenotypic and functional abnormalities were partially restored in the 12 patients achieving remission. In vitro co-incubation of acute myeloid leukemia blasts with natural killer cells from healthy donors induced significant impairment in natural killer cell TNF-α and IFN-γ production (P=0.02 and P=0.01, respectively) against K562 targets and a trend to reduced CD107a degranulation (P=0.07). Under transwell conditions, the inhibitory effect of AML blasts on NK cytotoxicity and effector function was still present, and this inhibitory effect was primarily mediated by IL-10. These results suggest that acute myeloid leukemia blasts induce long-lasting changes in natural killer cells, impairing their effector function and reducing the competence of the innate immune system, favoring leukemia survival. PMID:24488563

  20. Leukemia-induced phenotypic and functional defects in natural killer cells predict failure to achieve remission in acute myeloid leukemia

    PubMed Central

    Stringaris, Kate; Sekine, Takuya; Khoder, Ahmad; Alsuliman, Abdullah; Razzaghi, Bonnie; Sargeant, Ruhena; Pavlu, Jiri; Brisley, Gill; de Lavallade, Hugues; Sarvaria, Anushruthi; Marin, David; Mielke, Stephan; Apperley, Jane F.; Shpall, Elizabeth J.; Barrett, A. John; Rezvani, Katayoun

    2014-01-01

    The majority of patients with acute myeloid leukemia will relapse, and older patients often fail to achieve remission with induction chemotherapy. We explored the possibility that leukemic suppression of innate immunity might contribute to treatment failure. Natural killer cell phenotype and function was measured in 32 consecutive acute myeloid leukemia patients at presentation, including 12 achieving complete remission. Compared to 15 healthy age-matched controls, natural killer cells from acute myeloid leukemia patients were abnormal at presentation, with downregulation of the activating receptor NKp46 (P=0.007) and upregulation of the inhibitory receptor NKG2A (P=0.04). Natural killer cells from acute myeloid leukemia patients had impaired effector function against autologous blasts and K562 targets, with significantly reduced CD107a degranulation, TNF-α and IFN-γ production. Failure to achieve remission was associated with NKG2A overexpression and reduced TNF-α production. These phenotypic and functional abnormalities were partially restored in the 12 patients achieving remission. In vitro co-incubation of acute myeloid leukemia blasts with natural killer cells from healthy donors induced significant impairment in natural killer cell TNF-α and IFN-γ production (P=0.02 and P=0.01, respectively) against K562 targets and a trend to reduced CD107a degranulation (P=0.07). Under transwell conditions, the inhibitory effect of AML blasts on NK cytotoxicity and effector function was still present, and this inhibitory effect was primarily mediated by IL-10. These results suggest that acute myeloid leukemia blasts induce long-lasting changes in natural killer cells, impairing their effector function and reducing the competence of the innate immune system, favoring leukemia survival. PMID:24488563

  1. The intensive terahertz electroluminescence induced by Bloch oscillations in SiC natural superlattices

    PubMed Central

    2012-01-01

    We report on efficient terahertz (THz) emission from high-electric-field-biased SiC structures with a natural superlattice at liquid helium temperatures. The emission spectrum demonstrates a single line, the maximum of which shifts linearly with increases in bias field. We attribute this emission to steady-state Bloch oscillations of electrons in the SiC natural superlattice. The properties of the THz emission agree fairly with the parameters of the Bloch oscillator regime, which have been proven by high-field electron transport studies of SiC structures with natural superlattices. PMID:23043773

  2. Light-Induced Transformations of the C60 Derivative, Fullerenol: Interactions with Natural Organic Matter

    EPA Science Inventory

    Recent studies have indicated that fullerenes, an important class of nanomaterials, are photodegraded by solar radiation and can sensitize the photoproduction of reactive oxygen species such as singlet oxygen. Because natural organic matter (NOM) can retard photoreactions that a...

  3. Natural and Induced Polyploidy in Acacia dealbata Link. and Acacia mangium Willd.

    PubMed Central

    BLAKESLEY, DAVID; ALLEN, ANNABEL; PELLNY, TILL K.; ROBERTS, ANDY V.

    2002-01-01

    Seeds were obtained from seven natural populations of Acacia dealbata, three natural populations of A. mangium and a seed orchard of A. mangium, representing the natural range of the two species. Polyploids were discovered in two of the seven populations of A. dealbata. The 2C DNA amount for diploid A. dealbata (2n = 2x = 26) was 1·74 pg, and for diploid A. mangium (2n = 2x = 26) was 1·30 pg. A naturally occurring tetraploid of A. dealbata (2n = 4x = 52) had a 2C DNA amount of 3·41 pg and a naturally occurring triploid genotype had a 2C DNA amount of 2·53 pg. The use of colchicine and oryzalin was investigated as a means of producing higher frequencies of tetraploids of both A. mangium and A. dealbata for incorporation into breeding programmes. Colchicine treatment gave tetraploid frequencies up to 29 % for A. dealbata seedlings, and up to 18 % for A. mangium seedlings. In contrast, no tetraploid A. mangium was detected following oryzalin treatment, and the low frequencies of tetraploids observed in A. dealbata could be attributed to their natural occurrence. PMID:12234151

  4. Natural and induced polyploidy in Acacia dealbata Link. and Acacia mangium Willd.

    PubMed

    Blakesley, David; Allen, Annabel; Pellny, Till K; Roberts, Andy V

    2002-09-01

    Seeds were obtained from seven natural populations of Acacia dealbata, three natural populations of A. mangium and a seed orchard of A. mangium, representing the natural range of the two species. Polyploids were discovered in two of the seven populations of A. dealbata. The 2C DNA amount for diploid A. dealbata (2n = 2x = 26) was 1.74 pg, and for diploid A. mangium (2n = 2x = 26) was 1.30 pg. A naturally occurring tetraploid of A. dealbata (2n = 4x = 52) had a 2C DNA amount of 3.41 pg and a naturally occurring triploid genotype had a 2C DNA amount of 2.53 pg. The use of colchicine and oryzalin was investigated as a means of producing higher frequencies of tetraploids of both A. mangium and A. dealbata for incorporation into breeding programmes. Colchicine treatment gave tetraploid frequencies up to 29% for A. dealbata seedlings, and up to 18% for A. mangium seedlings. In contrast, no tetraploid A. mangium was detected following oryzalin treatment, and the low frequencies of tetraploids observed in A. dealbata could be attributed to their natural occurrence. PMID:12234151

  5. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    SciTech Connect

    Lyu, Qing; Tou, Fangfang; Su, Hong; Wu, Xiaoyong; Chen, Xinyi; Zheng, Zhi

    2015-06-19

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway.

  6. Discrimination between induced, triggered, and natural earthquakes close to hydrocarbon reservoirs: A probabilistic approach based on the modeling of depletion-induced stress changes and seismological source parameters

    NASA Astrophysics Data System (ADS)

    Dahm, Torsten; Cesca, Simone; Hainzl, Sebastian; Braun, Thomas; Krüger, Frank

    2015-04-01

    Earthquakes occurring close to hydrocarbon fields under production are often under critical view of being induced or triggered. However, clear and testable rules to discriminate the different events have rarely been developed and tested. The unresolved scientific problem may lead to lengthy public disputes with unpredictable impact on the local acceptance of the exploitation and field operations. We propose a quantitative approach to discriminate induced, triggered, and natural earthquakes, which is based on testable input parameters. Maxima of occurrence probabilities are compared for the cases under question, and a single probability of being triggered or induced is reported. The uncertainties of earthquake location and other input parameters are considered in terms of the integration over probability density functions. The probability that events have been human triggered/induced is derived from the modeling of Coulomb stress changes and a rate and state-dependent seismicity model. In our case a 3-D boundary element method has been adapted for the nuclei of strain approach to estimate the stress changes outside the reservoir, which are related to pore pressure changes in the field formation. The predicted rate of natural earthquakes is either derived from the background seismicity or, in case of rare events, from an estimate of the tectonic stress rate. Instrumentally derived seismological information on the event location, source mechanism, and the size of the rupture plane is of advantage for the method. If the rupture plane has been estimated, the discrimination between induced or only triggered events is theoretically possible if probability functions are convolved with a rupture fault filter. We apply the approach to three recent main shock events: (1) the Mw 4.3 Ekofisk 2001, North Sea, earthquake close to the Ekofisk oil field; (2) the Mw 4.4 Rotenburg 2004, Northern Germany, earthquake in the vicinity of the Söhlingen gas field; and (3) the Mw 6

  7. Integrative analyses of human reprogramming reveal dynamic nature of induced pluripotency

    PubMed Central

    Cacchiarelli, Davide; Trapnell, Cole; Ziller, Michael J.; Soumillon, Magali; Cesana, Marcella; Karnik, Rahul; Donaghey, Julie; Smith, Zachary D.; Ratanasirintrawoot, Sutheera; Zhang, Xiaolan; Ho Sui, Shannan J.; Wu, Zhaoting; Akopian, Veronika; Gifford, Casey A.; Doench, John; Rinn, John L.; Daley, George Q.; Meissner, Alexander; Lander, Eric S.; Mikkelsen, Tarjei S.

    2015-01-01

    Summary Induced pluripotency is a promising avenue for disease modeling and therapy, but the molecular principles underlying this process, particularly in human cells, remain poorly understood due to donor-to-donor variability and intercellular heterogeneity. Here we constructed and characterized a clonal, inducible human reprogramming system that provides a reliable source of cells at any stage of the process. This system enabled integrative transcriptional and epigenomic analysis across the human reprogramming timeline at high resolution. We observed distinct waves of gene network activation, including the ordered reactivation of broad developmental regulators followed by early embryonic patterning genes and culminating in the emergence of a signature reminiscent of pre-implantation stages. Moreover, complementary functional analyses allowed us to identify and validate novel regulators of the reprogramming process. Altogether, this study sheds light on the molecular underpinnings of induced pluripotency in human cells and provides a robust cell platform for further studies. PMID:26186193

  8. Chemoprevention of mammary tumor virus-induced and chemical carcinogen-induced rodent mammary tumors by natural plant products.

    PubMed

    Bhide, S V; Azuine, M A; Lahiri, M; Telang, N T

    1994-01-01

    The natural plant products turmeric, beta-carotene, catechin, and betel leaf extract were evaluated for their antitumor effects on mammary tumorigenesis in murine mammary tumor expressing C3H (Jax) mice and in Wistar rats treated with the chemical carcinogen 7-12-dimethylbenz(a)anthracene (DMBA). Administration of turmeric through the diet and of beta-carotene, catechin, and betel leaf extract through the drinking water to virgin female C3H mice resulted in decreased tumor incidence and tumor burden. Administering 5% turmeric in the diet from 2 months of age showed suppression of mammary tumor virus-related reverse transcriptase activity and of preneoplastic changes in the mammary glands. Furthermore, feeding turmeric from 6 months of age resulted in a 100% inhibition of mammary tumors. In the DMBA model of rat mammary tumorigenesis, administration of turmeric, catechin, and betel leaf extract resulted in decreased tumor burden and tumor incidence, and a delay in the onset of mammary tumors. PMID:7526904

  9. New Insights into the Relationship Between Network Structure and Strain Induced Crystallization in Unvolcanized Natural Rubber by Synchrotron X-ray Diffraction

    SciTech Connect

    Toki, S.; Hsiao, B; Amnuaypornsri, S; Sakdapipanich, J

    2009-01-01

    The relationship between the network structure and strain-induced crystallization in un-vulcanized as well as vulcanized natural rubbers (NR) and synthetic poly-isoprene rubbers (IR) was investigated via synchrotron wide-angle X-ray diffraction (WAXD) technique. It was found that the presence of a naturally occurring network structure formed by natural components in un-vulcanized NR significantly facilitates strain-induced crystallization and enhances modulus and tensile strength. The stress-strain relation in vulcanized NR is due to the combined effect of chemical and naturally occurring networks. The weakness of naturally occurring network against stress and temperature suggests that vulcanized NR has additional relaxation mechanism due to naturally occurring network. The superior mechanical properties in NR compared with IR are mainly due to the existence of naturally occurring network structure.

  10. Role of Induced Magnetic Field on Transient Natural Convection Flow in a Vertical Channel: The Riemann Sum Approximation Approach

    NASA Astrophysics Data System (ADS)

    Jha, B. K.; Sani, I.

    2015-02-01

    This paper investigates the role of induced magnetic field on a transient natural convection flow of an electrically conducting, incompressible and viscous fluid in a vertical channel formed by two infinite vertical parallel plates. The transient flow formation inside the channel is due to sudden asymmetric heating of channel walls. The time dependent momentum, energy and magnetic induction equations are solved semi-analytically using the Laplace transform technique along with the Riemann-sum approximation method. The solutions obtained are validated by comparisons with the closed form solutions obtained for the steady states which have been derived separately and also by the implicit finite difference method. Graphical results for the temperature, velocity, induced magnetic field, current density, and skin-friction based on the semi-analytical solutions are presented and discussed.

  11. Natural Diterpenes from Coffee, Cafestol, and Kahweol Induce Peripheral Antinoceception by Adrenergic System Interaction.

    PubMed

    Guzzo, Luciana Souza; Castor, Marina Gomes Miranda E; Perez, Andrea de Castro; Duarte, Igor Dimitri Gama; Romero, Thiago Roberto Lima

    2016-01-01

    Cafestol and kahweol are diterpenes found only in the non-saponified lipid fraction of coffee. They are released during boiling and retained in the filtration process. Previous studies have shown peripheral antinociception induced by endogenous opioid peptides released by these diterpenes. Considering that the activation of the opioid system leads to a noradrenaline release, the aim of this study was to verify the participation of the noradrenergic system in the peripheral antinociception induced by cafestol and kahweol. Hyperalgesia was induced by an intraplantar injection of prostaglandin E2 (2 µg). Cafestol or kahweol (80 µg/paw) were administered locally into the right hindpaw alone, and after the agents α 2-adrenoceptor antagonist yohimbine (5, 10 and 20 µg/paw), α 2 A-adrenoceptor antagonist BRL 44 408 (40 µg/paw), α 2B-adrenoceptor antagonist imiloxan (40 µg/paw), α 2 C-adrenoceptor antagonist rauwolscine (10, 15 and 20 µg/paw), α 2D-adrenoceptor antagonist RX 821 002 (40 µg/paw), α 1-adrenoceptor antagonist prazosin (0.5, 1 and 2 µg/paw), or β-adrenoceptor antagonist propranolol (150, 300 and 600 ng/paw), respectively. Noradrenaline reuptake inhibitor reboxetine (30 µg/paw) was administered prior to cafestol or kahweol low dose (40 µg/paw) and guanetidine 3 days prior to the experiment (30 mg/kg, once a day), depleting the noradrenaline storage. Intraplantar injection of cafestol or kahweol (80 µg/paw) induced a peripheral antinociception against hyperalgesia induced by PGE2. This effect was reversed by intraplantar injections of yohimbine, rauwolscine, prazosin and propranolol. Reboxetine injection intensified the antinociceptive effect of cafestol or kahweol low-dose, and guanethidine reversed almost 70 % of the cafestol or kahweol-induced peripheral antinociception. This study gives evidence that the noradrenergic system participates in cafestol and kahweol-induced peripheral antinociception with the

  12. Hepatoprotective effect of the natural fruit juice from Aronia melanocarpa on carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Valcheva-Kuzmanova, S; Borisova, P; Galunska, B; Krasnaliev, I; Belcheva, A

    2004-12-01

    The fruits of Aronia melanocarpa are rich in anthocyanins--plant pigments with anti-inflammatory and antioxidant activity. We studied the effect of the natural fruit juice from A. melanocarpa (NFJAM) on carbon tetrachloride (CCl4)-induced acute liver damage in rats. Histopathological changes such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins occurred in rats following acute exposure to CCl4 (0.2 ml kg(-1), 2 days). The administration of CCl4 increased plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, induced lipid peroxidation (as measured by malondialdehyde (MDA) content in rat liver and plasma) and caused a depletion of liver reduced glutathione (GSH). NFJAM (5, 10 and 20 ml kg(-1), 4 days) dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of plasma AST and ALT activities, induced by CCl4 (0.2ml kg(-1), 3rd and 4th days). NFJAM also prevented the CCl4-induced elevation of MDA formation and depletion of GSH content in rat liver. PMID:15625789

  13. Dormancy in potato tuber meristems: chemically induced cessation in dormancy matches the natural process based on transcript profiles.

    PubMed

    Campbell, Michael; Segear, Erika; Beers, Lee; Knauber, Donna; Suttle, Jeffrey

    2008-11-01

    Meristem dormancy in perennial plants is a developmental process that results in repression of metabolism and growth. The cessation of dormancy results in rapid growth and should be associated with the production of nascent transcripts that encode for gene products controlling for cell division and growth. Dormancy cessation was allowed to progress normally or was chemically induced using bromoethane (BE), and microarray analysis was used to demonstrate changes in specific transcripts in response to dormancy cessation before a significant increase in cell division. Comparison of normal dormancy cessation to BE-induced dormancy cessation revealed a commonality in both up and downregulated transcripts. Many transcripts that decrease as dormancy terminates are inducible by abscisic acid particularly in the conserved BURP domain proteins, which include the RD22 class of proteins and in the storage protein patatin. Transcripts that are associated with an increase in expression encoded for proteins in the oxoglutarate-dependent oxygenase family. We conclude that BE-induced cessation of dormancy initiates transcript profiles similar to the natural processes that control dormancy. PMID:18317824

  14. An interpretation of induced electric currents in long pipelines caused by natural geomagnetic sources of the upper atmosphere

    USGS Publications Warehouse

    Campbell, W.H.

    1986-01-01

    Electric currents in long pipelines can contribute to corrosion effects that limit the pipe's lifetime. One cause of such electric currents is the geomagnetic field variations that have sources in the Earth's upper atmosphere. Knowledge of the general behavior of the sources allows a prediction of the occurrence times, favorable locations for the pipeline effects, and long-term projections of corrosion contributions. The source spectral characteristics, the Earth's conductivity profile, and a corrosion-frequency dependence limit the period range of the natural field changes that affect the pipe. The corrosion contribution by induced currents from geomagnetic sources should be evaluated for pipelines that are located at high and at equatorial latitudes. At midlatitude locations, the times of these natural current maxima should be avoided for the necessary accurate monitoring of the pipe-to-soil potential. ?? 1986 D. Reidel Publishing Company.

  15. The possible effects of the natural and induced space environment on the optical and thermal properties of EOS surfaces

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Heppner, Richard A.

    1992-01-01

    Space missions, including that of EOS (Earth Observing System), will continue to be subjected to both the natural and induced space environment. The concerns associated with this fact will not go away. The NASA and DoD have recognized the need for long-life stability of materials and structures to the space environment. The major areas of interest include: thermal cycling, UV degradation, space radiation exposure, orbital debris, atomic oxygen erosion, and contamination control. Having flown a number of space environmental effects monitors, SAIC has developed both a data base to understand the magnitude of this problem and mitigation techniques to reduce the impact.

  16. Rapid changes in extracellular glutamate induced by natural arousing stimuli and intravenous cocaine in the nucleus accumbens shell and core

    PubMed Central

    Wakabayashi, Ken T.

    2012-01-01

    Glutamate (Glu) is a major excitatory neurotransmitter, playing a crucial role in the functioning of the nucleus accumbens (NAc), a critical area implicated in somatosensory integration and regulation of motivated behavior. In this study, high-speed amperometry with enzyme-based biosensors was used in freely moving rats to examine changes in extracellular Glu in the NAc shell and core induced by a tone, tail pinch (TP), social interaction with a male conspecific (SI), and intravenous (iv) cocaine (1 mg/kg). To establish the contribution of Glu to electrochemical signal changes, similar recordings were conducted with null (Glu0) sensors, which were exposed to the same chemical and physical environment but were insensitive to Glu. TP, SI, and cocaine, but not a tone, induced relatively large and prolonged current increases detected by both Glu and Glu0 sensors. However, current differentials revealed very rapid, much smaller, and transient increases in extracellular Glu levels, more predominantly in the NAc shell than core. In contrast to monophasic responses with natural stimuli, cocaine induced a biphasic Glu increase in the shell, with a transient peak during the injection and a slower postinjection peak. Therefore, Glu is phasically released in the NAc after exposure to natural arousing stimuli and cocaine; this release is rapid, stimulus dependent, and structure specific, suggesting its role in triggering neural and behavioral activation induced by these stimuli. This study also demonstrates the need for multiple in vitro and in vivo controls to reveal relatively small, highly phasic, and transient fluctuations in Glu levels occurring under behaviorally relevant conditions. PMID:22496525

  17. Connecting Model Species to Nature: Predator-Induced Long-Term Sensitization in "Aplysia Californica"

    ERIC Educational Resources Information Center

    Mason, Maria J.; Watkins, Amanda J.; Wakabayashi, Jordann; Buechler, Jennifer; Pepino, Christine; Brown, Michelle; Wright, William G.

    2014-01-01

    Previous research on sensitization in "Aplysia" was based entirely on unnatural noxious stimuli, usually electric shock, until our laboratory found that a natural noxious stimulus, a single sublethal lobster attack, causes short-term sensitization. We here extend that finding by demonstrating that multiple lobster attacks induce…

  18. NATURAL ENVIRONMENT SURPASSES POLLUTED ENVIRONMENT IN INDUCING DNA DAMAGE IN FISH

    EPA Science Inventory

    Measurement of specific DNA adduct concentrations in target tissues of organisms may provide a key biologic end-point of exposure to environmental carcinogens. sing a general and highly sensitive assay with 32P-postlabeling, we found that natural popultions of freshwater fish spe...

  19. Two-degree-of-freedom flow-induced vibrations on isolated and tandem cylinders with varying natural frequency ratios

    NASA Astrophysics Data System (ADS)

    Bao, Yan; Huang, Cheng; Zhou, Dai; Tu, Jiahuang; Han, Zhaolong

    2012-11-01

    A numerical study is performed on the flow-induced vibrations of isolated and tandem elastically mounted cylinders having two degrees of freedom and a variety of the in-line to the transverse natural frequency ratio, fnx/fny. The characteristic-based-split finite element method is utilized to obtain the solution of the incompressible flow equations in primitive variables. The Reynolds number, based on the upstream flow velocity U∞ and the diameter of the cylinder D, is fixed at Re=150, and for a tandem arrangement, the centre-to-centre distance between the cylinders is 5.0D. The computation is carried out at a lower reduced mass ratio of Mr=2.0 and for a wide range of reduced velocities (Ur=3.0-12.0). The structural damping ratio is set to zero to maximize the vortex-induced response of the bodies. In this study, we mainly focused on the effect of the natural frequency ratio on the characteristics of vortex-induced vibration (VIV) responses, including wake frequencies, orbital trajectories, response amplitudes, hydrodynamic forces and wake mode patterns. The natural frequency ratio is varied in the range of fnx/fny=1.0-2.0 with an increment of 0.25. We found that the condition of the occurrence of a dual-resonant response exists over a broad range of tested natural frequency ratios. A third harmonic frequency component appears in the lift fluctuation, along with additional multi-harmonics, which also interact with the drag frequency. Instead of double response peaks, multiple small peaks occur in the amplitude response of the cylinder. These peaks are distributed over a narrow range of Ur from 4.45 to 5.15, and their magnitudes increase with the increase in Ur. For a tandem arrangement, the response characteristic of the upstream cylinder is similar to that of a single cylinder, whereas that of the downstream cylinder is greatly affected by the upstream wake. For a downstream cylinder, the in-line dynamic response is more sensitive to the natural frequency ratio

  20. A novel structural derivative of natural alkaloid ellipticine, MDPSQ, induces necrosis in leukemic cells.

    PubMed

    Shahabuddin, M S; Nambiar, Mridula; Moorthy, Balaji T; Naik, Prakruthi L; Choudhary, Bibha; Advirao, Gopal M; Raghavan, Sathees C

    2011-08-01

    DNA intercalating molecules are promising chemotherapeutic agents. In the present study, a novel DNA intercalating compound of pyrimido[4',5':4,5]selenolo(2,3-b)quinoline series having 8-methyl-4-(3 diethylaminopropylamino) side chain is studied for its chemotherapeutic properties. Our results showed that 8-methyl-4-(3 diethylaminopropylamino) pyrimido [4',5':4,5] selenolo(2,3-b)quinoline (MDPSQ) induces cytotoxicity in a time- and concentration-dependent manner on leukemic cell lines. Both cell cycle analysis and tritiated thymidine assays revealed that MDPSQ affects DNA replication. Treatment with MDPSQ resulted in both elevated levels of DNA strand breaks and repair proteins, further indicating its cytotoxic effects. Besides, Annexin V/PI staining revealed that MDPSQ induces cell death by triggering necrosis rather than apoptosis. PMID:20069337

  1. US -endorphin-(1-27) is a naturally occurring antagonist to etorphine-induced analgesia

    SciTech Connect

    Nicolas, P.; Li, C.H.

    1985-05-01

    The potent opioid peptide US -endorphin is found in the brain and pituitary with two related fragments, US -endorphin-(1-27) and US -endorphin-(1-26). The fragments, retain substantial opioid-receptor binding activity but are virtually inactive analgesically. US -Endorphin-(1-27) inhibits US -endorphin-induced and etorphine-induced analgesia when coinjected intracerebroventricularly into mice. Antagonism by competition at the same site(s) is suggested from parallel shifts of the dose-response curves of etorphine or US -endorphin in the presence of US -endorphin-(1-27). Its potency is 4-5 times greater than that of the opiate antagonist naloxone. US -Endorphin-(1-26) does not antagonize the antinociceptive action of etorphine or US -endorphin in doses up to 500 pmol per animal.

  2. Natural Antioxidant Betanin Protects Rats from Paraquat-Induced Acute Lung Injury Interstitial Pneumonia

    PubMed Central

    Ma, Deshun; Zhang, Miao; Yang, Xuelian; Tan, Dehong

    2015-01-01

    The effect of betanin on a rat paraquat-induced acute lung injury (ALI) model was investigated. Paraquat was injected intraperitoneally at a single dose of 20 mg/kg body weight, and betanin (25 and 100 mg/kg/d) was orally administered 3 days before and 2 days after paraquat administration. Rats were sacrificed 24 hours after the last betanin dosage, and lung tissue and bronchoalveolar lavage fluid (BALF) were collected. In rats treated only with paraquat, extensive lung injury characteristic of ALI was observed, including histological changes, elevation of lung : body weight ratio, increased lung permeability, increased lung neutrophilia infiltration, increased malondialdehyde (MDA) and myeloperoxidase (MPO) activity, reduced superoxide dismutase (SOD) activity, reduced claudin-4 and zonula occluden-1 protein levels, increased BALF interleukin (IL-1) and tumor necrosis factor (TNF)-α levels, reduced BALF IL-10 levels, and increased lung nuclear factor kappa (NF-κB) activity. In rats treated with betanin, paraquat-induced ALI was attenuated in a dose-dependent manner. In conclusion, our results indicate that betanin attenuates paraquat-induced ALI possibly via antioxidant and anti-inflammatory mechanisms. Thus, the potential for using betanin as an auxilliary therapy for ALI should be explored further. PMID:25861636

  3. Numerical calculation of the drag force induced by natural convection of spheres at low Grashof numbers

    SciTech Connect

    Dudek, D.; Fletcher, T.H.

    1987-02-01

    When a heated solid sphere is introduced into an ambient fluid, a natural convective flow occurs which results in a drag force on the sphere. This study involves the numerical calculation of both the steady-state and the transient natural convective drag force around spheres at low Grashof numbers. Numerical techniques are taken from Geoola and Cornish. An empirical expression is suggested for the total drag coefficient for Grashof numbers ranging from 4 x 10/sup -4/ to 0.5 and Prandtl number = 0.72: log C/sub DT/ = 1.25 + 0.31 log Gr - 0.097(log Gr)/sup 2/. The dimensionless time required to reach 90% of the steady-state drag force can be approximated by the second-order polynomial: log t/sub 90%/ = 1.32 - log Gr - 0.11(Gr)/sup 2/.

  4. A Transient Model of Induced Natural Circulation Thermal Cycling for Hydrogen Isotope Separation

    SciTech Connect

    SHADDAY, MARTIN

    2005-07-12

    The property of selective temperature dependence of adsorption and desorption of hydrogen isotopes by palladium is used for isotope separation. A proposal to use natural circulation of nitrogen to alternately heat and cool a packed bed of palladium coated beads is under active investigation, and a device consisting of two interlocking natural convection loops is being designed. A transient numerical model of the device has been developed to aid the design process. It is a one-dimensional finite-difference model, using the Boussinesq approximation. The thermal inertia of the pipe walls and other heat structures as well as the heater control logic is included in the model. Two system configurations were modeled and results are compared.

  5. Radiation-induced vulcanisation of natural rubber latex in presence of styrene-butadiene rubber latex

    NASA Astrophysics Data System (ADS)

    Chaudhari, C. V.; Bhardwaj, Y. K.; Patil, N. D.; Dubey, K. A.; Kumar, Virendra; Sabharwal, S.

    2005-04-01

    Radiation vulcanisation of natural rubber latex in presence of styrene butadiene rubber latex (SBRL) has been investigated. The cast films were characterised for their swelling properties, tensile strength and thermal stability as a function of radiation dose as well as SBRL content. The gel content, tensile strength and thermal stability of the copolymer films were found to increase with increasing the SBRL content in the feed solution and radiation dose.

  6. Natural variation in small molecule-induced TIR-NB-LRR signaling induces root growth arrest via EDS1- and PAD4-complexed R protein VICTR in Arabidopsis.

    PubMed

    Kim, Tae-Houn; Kunz, Hans-Henning; Bhattacharjee, Saikat; Hauser, Felix; Park, Jiyoung; Engineer, Cawas; Liu, Amy; Ha, Tracy; Parker, Jane E; Gassmann, Walter; Schroeder, Julian I

    2012-12-01

    In a chemical genetics screen we identified the small-molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) that triggers rapid inhibition of early abscisic acid signal transduction via PHYTOALEXIN DEFICIENT4 (PAD4)- and ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)-dependent immune signaling mechanisms. However, mechanisms upstream of EDS1 and PAD4 in DFPM-mediated signaling remain unknown. Here, we report that DFPM generates an Arabidopsis thaliana accession-specific root growth arrest in Columbia-0 (Col-0) plants. The genetic locus responsible for this natural variant, VICTR (VARIATION IN COMPOUND TRIGGERED ROOT growth response), encodes a TIR-NB-LRR (for Toll-Interleukin1 Receptor-nucleotide binding-Leucine-rich repeat) protein. Analyses of T-DNA insertion victr alleles showed that VICTR is necessary for DFPM-induced root growth arrest and inhibition of abscisic acid-induced stomatal closing. Transgenic expression of the Col-0 VICTR allele in DFPM-insensitive Arabidopsis accessions recapitulated the DFPM-induced root growth arrest. EDS1 and PAD4, both central regulators of basal resistance and effector-triggered immunity, as well as HSP90 chaperones and their cochaperones RAR1 and SGT1B, are required for the DFPM-induced root growth arrest. Salicylic acid and jasmonic acid signaling pathway components are dispensable. We further demonstrate that VICTR associates with EDS1 and PAD4 in a nuclear protein complex. These findings show a previously unexplored association between a TIR-NB-LRR protein and PAD4 and identify functions of plant immune signaling components in the regulation of root meristematic zone-targeted growth arrest. PMID:23275581

  7. Study of plasma natural convection induced by electron beam in atmosphere [

    SciTech Connect

    Deng, Yongfeng Han, Xianwei; Tan, Yonghua

    2014-06-15

    Using high-energy electron beams to ionize air is an effective way to produce a large-size plasma in the atmosphere. In particular, with a steady-state high power generator, some unique phenomena can be achieved, including natural convection of the plasma. The characteristics of this convection are studied both experimentally and numerically. The results show that an asymmetrical temperature field develops with magnitudes that vary from 295 K to 389 K at a pressure of 100 Torr. Natural convection is greatly enhanced under 760 Torr. Nevertheless, plasma transport is negligible in this convection flow field and only the plasma core tends to move upward. Parameter analysis is performed to discern influencing factors on this phenomenon. The beam current, reflecting the Rayleigh number Ra effect, correlates with convection intensity, which indicates that energy deposition is the underlying key factor in determining such convections. Finally, natural convection is concluded to be an intrinsic property of the electron beam when focused into dense air, and can be achieved by carefully adjusting equipment operations parameters.

  8. Snag characteristics and dynamics following natural and artificially induced mortality in a managed loblolly pine forest.

    SciTech Connect

    Zarnoch, Stanley J.; Vukovich, Mark A.; Kilgo, John C.; Blake, John I.

    2013-06-10

    A 14-year study of snag characteristics was established in 41- to 44-year old loblolly pine (Pinus taeda L.) stands in southeastern USA. During the initial 5.5 years, no stand manipulation or unusually high-mortality events occurred. Afterwards, three treatments were applied consisting of trees thinned and removed, trees felled and not removed, and artificial creation of snags produced by girdling and herbicide injection. The thinned treatments were designed to maintain the same live canopy density as the snag-created treatment, disregarding snags that remained standing.We monitored snag height, diameter, density, volume, and bark percentage; the number of cavities was monitored in natural snags only. During the first 5.5 years, recruitment and loss rates were stable, resulting in a stable snag population. Large snags (≥25 cm diameter) were common, but subcanopy small snags (10 to <25 cm diameter) dominated numerically. Large natural snags survived (90% quantile) significantly longer (6.0–9.4 years) than smaller snags (4.4–6.9 years). Large artificial snags persisted the longest (11.8 years). Cavities in natural snags developed within 3 years following tree death. The mean number of cavities per snag was five times greater in large versus small snags and large snags were more likely to have multiple cavities, emphasizing the importance of mature pine stands for cavity-dependent wildlife species.

  9. Protection of Erwinia amylovora bacteriophage Y2 from UV-induced damage by natural compounds

    PubMed Central

    Born, Yannick; Bosshard, Lars; Duffy, Brion; Loessner, Martin J.; Fieseler, Lars

    2015-01-01

    Bacteriophages have regained much attention as biocontrol agents against bacterial pathogens. However, with respect to stability, phages are biomolecules and are therefore sensitive to a number of environmental influences. UV-irradiation can readily inactivate phage infectivity, which impedes their potential application in the plant phyllosphere. Therefore, phages for control of Erwinia amylovora, the causative agent of fire blight, need to be protected from UV-damage by adequate measures. We investigated the protective effect of different light-absorbing substances on phage particles exposed to UV-light. For this, natural extracts from carrot, red pepper, and beetroot, casein and soy peptone in solution, and purified substances such as astaxanthin, aromatic amino acids, and Tween 80 were prepared and tested as natural sunscreens for phage. All compounds were found to significantly increase half-life of UV-irradiated phage particles and they did not negatively affect phage viability or infectivity. Altogether, a range of readily available, natural substances are suitable as UV-protectants to prevent phage particles from UV-light damage. PMID:26904378

  10. Variation in oxygen isotope ratio of dissolved orthophosphate induced by uptake process in natural coral holobionts

    NASA Astrophysics Data System (ADS)

    Ferrera, Charissa M.; Miyajima, Toshihiro; Watanabe, Atsushi; Umezawa, Yu; Morimoto, Naoko; San Diego-McGlone, Maria Lourdes; Nadaoka, Kazuo

    2016-06-01

    A model incubation experiment using natural zooxanthellate corals was conducted to evaluate the influence of phosphate uptake by coral holobionts on oxygen isotope ratio of dissolved PO4 3- (δ18Op). Live coral samples of Acropora digitifera, Porites cylindrica, and Heliopora coerulea were collected from coral reefs around Ishigaki Island (Okinawa, Japan) and Bolinao (northern Luzon, Philippines) and incubated for 3-5 d after acclimatization under natural light conditions with elevated concentrations of PO4 3-. Phosphate uptake by corals behaved linearly with incubation time, with uptake rate depending on temperature. δ18Op usually increased with time toward the equilibrium value with respect to oxygen isotope exchange with ambient seawater, but sometimes became higher than equilibrium value at the end of incubation. The magnitude of the isotope effect associated with uptake depended on coral species; the greatest effect was in A. digitifera and the smallest in H. coerulea. However, it varied even within samples of a single coral species, which suggests multiple uptake processes with different isotope effects operating simultaneously with varying relative contributions in the coral holobionts used. In natural environments where concentrations of PO4 3- are much lower than those used during incubation, PO4 3- is presumably turned over much faster and the δ18Op easily altered by corals and other major primary producers. This should be taken into consideration when using δ18Op as an indicator of external PO4 3- sources in coastal ecosystems.

  11. The three subtypes of tick-borne encephalitis virus induce encephalitis in a natural host, the bank vole (Myodes glareolus).

    PubMed

    Tonteri, Elina; Kipar, Anja; Voutilainen, Liina; Vene, Sirkka; Vaheri, Antti; Vapalahti, Olli; Lundkvist, Åke

    2013-01-01

    Tick-borne encephalitis virus (TBEV) infects bank voles (Myodes glareolus) in nature, but the relevance of rodents for TBEV transmission and maintenance is unclear. We infected colonized bank voles subcutaneously to study and compare the infection kinetics, acute infection, and potential viral persistence of the three known TBEV subtypes: European (TBEV-Eur), Siberian (TBEV-Sib) and Far Eastern (TBEV-FE). All strains representing the three subtypes were infective and highly neurotropic. They induced (meningo)encephalitis in some of the animals, however most of the cases did not present with apparent clinical symptoms. TBEV-RNA was cleared significantly slower from the brain as compared to other organs studied. Supporting our earlier findings in natural rodent populations, TBEV-RNA could be detected in the brain for up to 168 days post infection, but we could not demonstrate infectivity by cell culture isolation. Throughout all time points post infection, RNA of the TBEV-FE was detected significantly more often than RNA of the other two strains in all organs studied. TBEV-FE also induced prolonged viremia, indicating distinctive kinetics in rodents in comparison to the other two subtypes. This study shows that bank voles can develop a neuroinvasive TBEV infection with persistence of viral RNA in brain, and mount an anti-TBEV IgG response. The findings also provide further evidence that bank voles can serve as sentinels for TBEV endemicity. PMID:24349041

  12. The Three Subtypes of Tick-Borne Encephalitis Virus Induce Encephalitis in a Natural Host, the Bank Vole (Myodes glareolus)

    PubMed Central

    Tonteri, Elina; Kipar, Anja; Voutilainen, Liina; Vene, Sirkka; Vaheri, Antti; Vapalahti, Olli; Lundkvist, Åke

    2013-01-01

    Tick-borne encephalitis virus (TBEV) infects bank voles (Myodes glareolus) in nature, but the relevance of rodents for TBEV transmission and maintenance is unclear. We infected colonized bank voles subcutaneously to study and compare the infection kinetics, acute infection, and potential viral persistence of the three known TBEV subtypes: European (TBEV-Eur), Siberian (TBEV-Sib) and Far Eastern (TBEV-FE). All strains representing the three subtypes were infective and highly neurotropic. They induced (meningo)encephalitis in some of the animals, however most of the cases did not present with apparent clinical symptoms. TBEV-RNA was cleared significantly slower from the brain as compared to other organs studied. Supporting our earlier findings in natural rodent populations, TBEV-RNA could be detected in the brain for up to 168 days post infection, but we could not demonstrate infectivity by cell culture isolation. Throughout all time points post infection, RNA of the TBEV-FE was detected significantly more often than RNA of the other two strains in all organs studied. TBEV-FE also induced prolonged viremia, indicating distinctive kinetics in rodents in comparison to the other two subtypes. This study shows that bank voles can develop a neuroinvasive TBEV infection with persistence of viral RNA in brain, and mount an anti-TBEV IgG response. The findings also provide further evidence that bank voles can serve as sentinels for TBEV endemicity. PMID:24349041

  13. Human Cytomegalovirus-Induced NKG2Chi CD57hi Natural Killer Cells Are Effectors Dependent on Humoral Antiviral Immunity

    PubMed Central

    Wu, Zeguang; Sinzger, Christian; Frascaroli, Giada; Reichel, Johanna; Bayer, Carina; Wang, Li; Schirmbeck, Reinhold

    2013-01-01

    Recent studies indicate that expansion of NKG2C-positive natural killer (NK) cells is associated with human cytomegalovirus (HCMV); however, their activity in response to HCMV-infected cells remains unclear. We show that NKG2Chi CD57hi NK cells gated on CD3neg CD56dim cells can be phenotypically identified as HCMV-induced NK cells that can be activated by HCMV-infected cells. Using HCMV-infected autologous macrophages as targets, we were able to show that these NKG2Chi CD57hi NK cells are highly responsive to HCMV-infected macrophages only in the presence of HCMV-specific antibodies, whereas they are functionally poor effectors of natural cytotoxicity. We further demonstrate that NKG2Chi CD57hi NK cells are intrinsically responsive to signaling through CD16 cross-linking. Our findings show that the activity of pathogen-induced innate immune cells can be enhanced by adaptive humoral immunity. Understanding the activity of NKG2Chi CD57hi NK cells against HCMV-infected cells will be of relevance for the further development of adoptive immunotherapy. PMID:23637420

  14. The illusion of the positive: the impact of natural and induced mood on older adults' false recall.

    PubMed

    Emery, Lisa; Hess, Thomas M; Elliot, Tonya

    2012-11-01

    Recent research suggests that affective and motivational processes can influence age differences in memory. In the current study, we examine the impact of both natural and induced mood state on age differences in false recall. Older and younger adults performed a version of the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803) false memory paradigm in either their natural mood state or after a positive or negative mood induction. Results indicated that, after accounting for age differences in basic cognitive function, age-related differences in positive mood during the testing session were related to increased false recall in older adults. Inducing older adults into a positive mood also exacerbated age differences in false memory. In contrast, veridical recall did not appear to be systematically influenced by mood. Together, these results suggest that positive mood states can impact older adults' information processing and potentially increase underlying cognitive age differences. PMID:22292431

  15. The pepper's natural ingredient capsaicin induces autophagy blockage in prostate cancer cells

    PubMed Central

    Ramos-Torres, Ágata; Bort, Alicia; Morell, Cecilia; Rodríguez-Henche, Nieves; Díaz-Laviada, Inés

    2016-01-01

    Capsaicin, the pungent ingredient of red hot chili peepers, has been shown to have anti-cancer activities in several cancer cells, including prostate cancer. Several molecular mechanisms have been proposed on its chemopreventive action, including ceramide accumulation, endoplasmic reticulum stress induction and NFκB inhibition. However, the precise mechanisms by which capsaicin exerts its anti-proliferative effect in prostate cancer cells remain questionable. Herein, we have tested the involvement of autophagy on the capsaicin mechanism of action on prostate cancer LNCaP and PC-3 cells. The results showed that capsaicin induced prostate cancer cell death in a time- and concentration-dependent manner, increased the levels of microtubule-associated protein light chain 3-II (LC3-II, a marker of autophagy) and the accumulation of the cargo protein p62 suggesting an autophagy blockage. Moreover, confocal microscopy revealed that capsaicin treatment increased lysosomes which co-localized with LC3 positive vesicles in a similar extent to that produced by the lysosomal protease inhibitors E64 and pepstatin pointing to an autophagolysosomes breakdown inhibition. Furthermore, we found that capsaicin triggered ROS generation in cells, while the levels of ROS decreased with N-acetyl-cysteine (NAC), a ROS scavenger. Co-treatment of cells with NAC and capsaicin abrogated the effects of capsaicin on autophagy and cell death. Normal prostate PNT2 and RWPE-1 cells were more resistant to capsaicin-induced cytotoxicity and did not accumulate p62 protein. Taken together, these results suggest that ROS-mediated capsaicin-induced autophagy blockage contributes to antiproliferation in prostate cancer cells, which provides new insights into the anticancer molecular mechanism of capsaicin. PMID:26625315

  16. Incidence and nature of tumors induced in Sprague-Dawley rats by gamma-irradiation

    SciTech Connect

    Gross, L.; Dreyfuss, Y.; Faraggiana, T.

    1988-05-01

    In our previous studies carried out on inbred rats of the Sprague-Dawley strain, the tumor incidence was increased following irradiation (150 rads, 5 times, at weekly intervals), from 22 to 93% in females and from 5 to 59% in males. Experiments here reported suggest that 2 consecutive total-body gamma-irradiations of 150 rads each are sufficient to induce in rats the development of tumors, some malignant; 18 of 19 females (94.7%) developed tumors at an average age of 11.4 mo, and seven of the 14 males in this group (50%) developed tumors at an average age of 10.4 mo. In the second group, which received 3 consecutive gamma-irradiations, 20 of 23 females (86.9%) and 5 of 13 males (38.4%) developed tumors at average ages of 9.1 and 7.5 mo, respectively. In the third group, among rats which received 4 consecutive gamma-irradiations, 17 of 19 females (89.4%) and 4 of 12 males (33.3%) developed tumors at average ages of 9.4 and 10.5 mo, respectively. The etiology of tumors either developing spontaneously or induced by irradiation in rats remains to be clarified. Our attempts to detect virus particles by electron microscopy in such tumors or lymphomas have not been successful. As a working hypothesis, we are tempted to theorize that tumors or lymphomas developing spontaneously or induced by gamma irradiation in rats are caused by latent viral agents which are integrated into the cell genome and are cell associated, i.e., not separable from the rat tumor cells by conventional methods thus far used.

  17. Nature and mechanisms of hepatocyte apoptosis induced by d-galactosamine/lipopolysaccharide challenge in mice

    PubMed Central

    WU, YI-HANG; HU, SHAO-QING; LIU, JUN; CAO, HONG-CUI; XU, WEI; LI, YONG-JUN; LI, LAN-JUAN

    2014-01-01

    Apoptosis plays a role in the normal development of liver. However, overactivation thereof may lead to hepatocellular damage. The aim of this study was to assess d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced hepatocyte apoptotic changes in mice and clarify the mechanisms involved in this process. DNA ladder detection was employed to determine the induction condition of hepatic apoptosis. An initial test indicated that typical hepatocyte apoptosis was observed at 6–10 h after the intraperitoneal injection of d-GalN (700 mg/kg) and LPS (10 μg/kg). Subsequently, we evaluated hepatocyte apoptosis at 8 h after administering d-GalN/LPS by histopathological analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) detection, flow cytometry and electron microscopy analysis. To clarify the apoptosis-related gene expression, the expression levels of tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), caspase-3, and Fas/Fas ligand (FasL) were determined by serum enzyme immunoassay, immunohistochemistry and western blot analysis. Strong apoptotic positive signals following d-GalN/LPS injection were observed from the results of the serum analysis, histopathological and immunohistochemical analyses, DNA ladder detection, TUNEL detection, flow cytometry and electron microscopy analysis. Additionally, apoptotic hepatocytes were mainly at the late stage of cell apoptosis. The expression of TNF-α, TGF-β1, caspase-3 and Fas/FasL was significantly increased. In conclusion, this study evaluated the d-GalN/LPS-induced hepatocyte apoptotic changes and clarified the apoptosis-related gene expression in mice. The hepatocyte apoptosis induced by d-GalN/LPS may be mainly regulated by the death receptor pathway. TGF-β signaling pathway may also play a vital role in this process of hepatocyte apoptosis. PMID:24714963

  18. Nature of the Refractive Errors in Rhesus Monkeys (Macaca mulatta) with Experimentally Induced Ametropias

    PubMed Central

    Qiao-Grider, Ying; Hung, Li-Fang; Kee, Chea-su; Ramamirtham, Ramkumar; Smith, Earl L.

    2010-01-01

    We analyzed the contribution of individual ocular components to vision-induced ametropias in 210 rhesus monkeys. The primary contribution to refractive-error development came from vitreous chamber depth; a minor contribution from corneal power was also detected. However, there was no systematic relationship between refractive error and anterior chamber depth or between refractive error and any crystalline lens parameter. Our results are in good agreement with previous studies in humans, suggesting that the refractive errors commonly observed in humans are created by vision-dependent mechanisms that are similar to those operating in monkeys. This concordance emphasizes the applicability of rhesus monkeys in refractive-error studies. PMID:20600237

  19. Natural micro-scale heterogeneity induced solute and nanoparticle retardation in fractured crystalline rock.

    PubMed

    Huber, F; Enzmann, F; Wenka, A; Bouby, M; Dentz, M; Schäfer, T

    2012-05-15

    We studied tracer (Tritiated Water (HTO); Tritium replaces one of the stable hydrogen atoms in the H(2)O molecule) and nanoparticle (quantum dots (QD)) transport by means of column migration experiments and comparison to 3D CFD modeling. Concerning the modeling approach, a natural single fracture was scanned using micro computed tomography (μCT) serving as direct input for the model generation. The 3D simulation does not incorporate any chemical processes besides the molecular diffusion coefficient solely reflecting the impact of fracture heterogeneity on mass (solute and nanoparticles) transport. Complex fluid velocity distributions (flow channeling and flowpath heterogeneity) evolve as direct function of fracture geometry. Both experimental and simulated solute and colloidal breakthrough curves show heavy tailing (non-Fickian transport behavior), respectively. Regarding the type of quantum dots and geochemical conditions prevailing (Grimsel ground water chemistry, QD and diorite surface charge, respectively and porosity of the Äspö diorite drill core) experimental breakthrough of the quantum dots always arrives faster than the solute tracer in line with the modeling results. Besides retardation processes like sorption, filtration, straining or matrix diffusion, the results show that natural 3D fracture heterogeneity represents an important additional retardation mechanism for solutes and colloidal phases. This is clearly verified by the numerical simulations, where the 3D real natural fracture geometry and the resulting complex flow velocity distribution is the only possible process causing solute/nanoparticle retardation. Differences between the experimental results and the simulations are discussed with respect to uncertainties in the μCT measurements and experimental and simulation boundary conditions, respectively. PMID:22484609

  20. Delivering sustainable crop protection systems via the seed: exploiting natural constitutive and inducible defence pathways

    PubMed Central

    Pickett, John A.; Aradottír, Gudbjorg I.; Birkett, Michael A.; Bruce, Toby J. A.; Hooper, Antony M.; Midega, Charles A. O.; Jones, Huw D.; Matthes, Michaela C.; Napier, Johnathan A.; Pittchar, Jimmy O.; Smart, Lesley E.; Woodcock, Christine M.; Khan, Zeyaur R.

    2014-01-01

    To reduce the need for seasonal inputs, crop protection will have to be delivered via the seed and other planting material. Plant secondary metabolism can be harnessed for this purpose by new breeding technologies, genetic modification and companion cropping, the latter already on-farm in sub-Saharan Africa. Secondary metabolites offer the prospect of pest management as robust as that provided by current pesticides, for which many lead compounds were, or are currently deployed as, natural products. Evidence of success and promise is given for pest management in industrial and developing agriculture. Additionally, opportunities for solving wider problems of sustainable crop protection, and also production, are discussed. PMID:24535389

  1. Effect of natural honey from Ilam and metformin for improving glycemic control in streptozotocin-induced diabetic rats

    PubMed Central

    Nasrolahi, Ozra; Heidari, Reza; Rahmani, Fatima; Farokhi, Farah

    2012-01-01

    Objective(s): Diabetes mellitus is a public health problem and one of the five leading causes of death globally. In the present study, the effect of Metformin with natural honey was investigated on glycemia in the Streptozotocin-induced diabetic rats. Materials and Methods: Thirty Wistar male rats were randomly divided into six groups including C: non diabetic rats received distilled water, CH: non diabetic rats received honey, CD: diabetic rats administered with distilled water, DM: Metformin treated diabetic rats, DH: honey treated diabetic rats, and DMH: diabetic rats treated with a combination of Metformin and natural honey. Diabetes was induced by a single dose of Streptozotocin (65 mg/kg; i.p.). The animals were treated by oral gavage once daily for four weeks. At the end of the treatment period, the animals were sacrificed and their blood samples collected. Amount of glucose, triglyceride (TG), total cholesterol (TC), HDL cholesterol, LDL cholesterol, VLDL cholesterol, total bilirubin, and albumin were determined in serum. Results: Group CD: showed hyperglycemia (252.2±4.1 mg/dl), while level of blood glucose was significantly (p<0.01) reduced in groups DH (124.2±2.7 mg/dl), DM (108.0±3.4 mg/dl), and DMH (115.4±2.1 mg/dl). Honey in combination with Metformin significantly (p<0.01) reduced level of bilirubin but Metformin alone did not reduce bilirubin. Honey alone and in combination with Metformin also significantly reduced triglycerides, total cholesterol, LDL, VLDL and increased HDL, but Metformin did not reduced triglycerides and increased HDL. Conclusion: The results of the present study demonstrated that consuming natural honey with Metformin improves glycemic control and is more useful than consuming Metformin alone. The higher therapeutic effect of Ilam honey on lipid abnormalities than Tualang honey was also evident. PMID:25050251

  2. Size-dependent PM 10 indoor/outdoor/personal relationships for a wind-induced naturally ventilated airspace

    NASA Astrophysics Data System (ADS)

    Liao, Chung-Min; Chen, Jein-Wen; Huang, Su-Jui

    We applied a simple size-dependent indoor air quality model associated with a compartmental lung model to characterize PM 10 indoor-outdoor-personal exposure relationships for wind-induced naturally ventilated residences in Taiwan region. The natural ventilation rate was quantified by the opening effectiveness for sidewall opening (SP) and covered ridge with sidewall opening (CRSP) type homes. The predicted PM 10 mass indoor/outdoor (I/O) ratios were 0.15-0.24 and 0.20-0.32, respectively, for SP and CRSP type homes. Results demonstrate that PM 10 I/O ratios for a wind-induced naturally ventilated airspace depend strongly on the ambient PM size distributions, building openings design (e.g. height to length ratio of openings and roof slope), wind speed and wind angle of incidence. The predictions from our lung model agreed favorable with the experimental deposition profiles in extrathoracic (ET), bronchial-bronchiolar (BB), and alveolar-interstitial (AI) regions. Our results demonstrate that ET region has higher PM 10 mass lung/indoor ratios (for north Taiwan region: 0.67-0.78; for central: 0.66-0.74) than that of BB (for north: 0.36-0.57; for central: 0.33-0.47) and AI regions (for north: 0.05-0.35; for central: 0.02-0.22). The present approach can be used in the future to appraise the significance of inter-subject lung morphology and breathing physiology variability for PM deposition and dose calculations.

  3. Plasma Fibrinogen Is a Natural Deterrent to Amyloid β–Induced Platelet Activation and Neuronal Toxicity

    PubMed Central

    Sonkar, Vijay K; Kulkarni, Paresh P; Chaurasia, Susheel N; Dash, Ayusman; Jauhari, Abhishek; Parmar, Devendra; Yadav, Sanjay; Dash, Debabrata

    2016-01-01

    Alzheimer’s disease (AD) is a devastating neurodegenerative disorder, characterized by extensive loss of neurons and deposition of amyloid β (Aβ) in the form of extracellular plaques. Aβ is considered to have a critical role in synaptic loss and neuronal death underlying cognitive decline. Platelets contribute to 95% of circulating amyloid precursor protein that releases Aβ into circulation. We have recently demonstrated that the Aβ active fragment containing amino acid sequence 25–35 (Aβ25–35) is highly thrombogenic in nature and elicits strong aggregation of washed human platelets in a RhoA-dependent manner. In this study, we evaluated the influence of fibrinogen on Aβ-induced platelet activation. Intriguingly, Aβ failed to induce aggregation of platelets suspended in plasma but not in buffer. Fibrinogen brought about dose-dependent decline in aggregatory response of washed human platelets elicited by Aβ25–35, which could be reversed by increasing doses of Aβ. Fibrinogen also attenuated Aβ-induced platelet responses such as secretion, clot retraction, rise in cytosolic Ca+2 and reactive oxygen species. Fibrinogen prevented intracellular accumulation of full-length Aβ peptide (Aβ42) in platelets as well as neuronal cells. We conclude that fibrinogen serves as a physiological check against the adverse effects of Aβ by preventing its interaction with cells. PMID:27262026

  4. Preliminary investigation of topical nitroglycerin formulations containing natural wound healing agent in diabetes-induced foot ulcer.

    PubMed

    Hotkar, Mukesh S; Avachat, Amelia M; Bhosale, Sagar S; Oswal, Yogesh M

    2015-04-01

    Nitroglycerin (NTG) is an organic nitrate rapidly denitrated by enzymes to release free radical nitric oxide and shows improved wound healing and tissue protection from oxidative damage. The purpose of this study was to evaluate whether topical application of NTG in the form of gel/ointment along with a natural wound healing agent, aloe vera, would bring about wound healing by using diabetes-induced foot ulcer model and rat excision wound model. All these formulations were evaluated for pH, viscosity, drug content and ex vivo diffusion studies using rat skin. Based on ex vivo permeation studies, the formulation consisting of carbopol 974p as a gelling agent and aloe vera was found to be suitable. The in vivo study used streptozotocin-induced diabetic foot ulcer and rat excision wound models to analyse wound healing activity. The wound size in animals of all treated groups was significantly reduced compared with that of the diabetic control and marketed treated animals. This study showed that the gel formed with carbopol 974p (1%) and aloe vera promotes significant wound healing and closure in diabetic rats compared with the commercial product and provides a promising product to be used in diabetes-induced foot ulcer. PMID:23731451

  5. Human APOBEC3 Induced Mutation of Human Immunodeficiency Virus Type-1 Contributes to Adaptation and Evolution in Natural Infection

    PubMed Central

    Kim, Eun-Young; Lorenzo-Redondo, Ramon; Little, Susan J.; Chung, Yoon-Seok; Phalora, Prabhjeet K.; Maljkovic Berry, Irina; Archer, John; Penugonda, Sudhir; Fischer, Will; Richman, Douglas D.; Bhattacharya, Tanmoy; Malim, Michael H.; Wolinsky, Steven M.

    2014-01-01

    Human APOBEC3 proteins are cytidine deaminases that contribute broadly to innate immunity through the control of exogenous retrovirus replication and endogenous retroelement retrotransposition. As an intrinsic antiretroviral defense mechanism, APOBEC3 proteins induce extensive guanosine-to-adenosine (G-to-A) mutagenesis and inhibit synthesis of nascent human immunodeficiency virus-type 1 (HIV-1) cDNA. Human APOBEC3 proteins have additionally been proposed to induce infrequent, potentially non-lethal G-to-A mutations that make subtle contributions to sequence diversification of the viral genome and adaptation though acquisition of beneficial mutations. Using single-cycle HIV-1 infections in culture and highly parallel DNA sequencing, we defined trinucleotide contexts of the edited sites for APOBEC3D, APOBEC3F, APOBEC3G, and APOBEC3H. We then compared these APOBEC3 editing contexts with the patterns of G-to-A mutations in HIV-1 DNA in cells obtained sequentially from ten patients with primary HIV-1 infection. Viral substitutions were highest in the preferred trinucleotide contexts of the edited sites for the APOBEC3 deaminases. Consistent with the effects of immune selection, amino acid changes accumulated at the APOBEC3 editing contexts located within human leukocyte antigen (HLA)-appropriate epitopes that are known or predicted to enable peptide binding. Thus, APOBEC3 activity may induce mutations that influence the genetic diversity and adaptation of the HIV-1 population in natural infection. PMID:25080100

  6. An activation-induced IL-15 isoform is a natural antagonist for IL-15 function

    PubMed Central

    Zhao, Lei; Hu, Bo; Zhang, Yinsheng; Song, Yuan; Lin, Dandan; Liu, Yonghao; Mei, Yu; Sandikin, Dedy; Sun, Weiping; Zhuang, Min; Liu, Haiyan

    2016-01-01

    Interleukin 15 (IL-15) expression induces the secretion of inflammatory cytokines, inhibits the apoptosis of activated T cells and prolongs the survival of CD8+ memory T cells. Here we identified an IL-15 isoform lacking exon-6, IL-15ΔE6, generated by alternative splicing events of activated immune cells, including macrophages and B cells. In vitro study showed that IL-15ΔE6 could antagonize IL-15-mediated T cell proliferation. The receptor binding assay revealed that IL-15ΔE6 could bind to IL-15Rα and interfere with the binding between IL-15 and IL-15Rα. Over-expression of IL-15ΔE6 in the murine EAE model ameliorated the EAE symptoms of the mice. The clinical scores were significantly lower in the mice expressing IL-15ΔE6 than the control mice and the mice expressing IL-15. The inflammation and demyelination of the EAE mice expressing IL-15ΔE6 were less severe than the control group. Furthermore, flow cytometry analysis demonstrated that IL-15ΔE6 expression reduced the percentages of inflammatory T cells in the spleen and spinal cord, and inhibited the infiltration of macrophages to the CNS. Our results demonstrated that IL-15ΔE6 could be induced during immune activation and function as a negative feedback mechanism to dampen IL-15-mediated inflammatory events. PMID:27166125

  7. Stuttering, Induced Fluency, and Natural Fluency: A Hierarchical Series of Activation Likelihood Estimation Meta-Analyses

    PubMed Central

    Budde, Kristin S.; Barron, Daniel S.; Fox, Peter T.

    2015-01-01

    Developmental stuttering is a speech disorder most likely due to a heritable form of developmental dysmyelination impairing the function of the speech-motor system. Speech-induced brain-activation patterns in persons who stutter (PWS) are anomalous in various ways; the consistency of these aberrant patterns is a matter of ongoing debate. Here, we present a hierarchical series of coordinate-based meta-analyses addressing this issue. Two tiers of meta-analyses were performed on a 17-paper dataset (202 PWS; 167 fluent controls). Four large-scale (top-tier) meta-analyses were performed, two for each subject group (PWS and controls). These analyses robustly confirmed the regional effects previously postulated as “neural signatures of stuttering” (Brown 2005) and extended this designation to additional regions. Two smaller-scale (lower-tier) meta-analyses refined the interpretation of the large-scale analyses: 1) a between-group contrast targeting differences between PWS and controls (stuttering trait); and 2) a within-group contrast (PWS only) of stuttering with induced fluency (stuttering state). PMID:25463820

  8. Immune response to UV-induced tumors: mediation of progressor tumor rejection by natural killer cells

    SciTech Connect

    Streeter, P.R.; Fortner, G.W.

    1986-03-01

    Skin tumors induced in mice by chronic ultraviolet (UV) irradiation are highly antigenic and can induce a state of transplantation immunity in syngeneic animals. In the present study, the authors compared the in vitro cytolytic activity of splenic lymphocytes from mice immunized with either regressor or progressor UV-tumors. The results of this comparison implicated tumor-specific cytolytic T (Tc) lymphocytes in rejection of regressor UV-tumors, and revealed that immunization with the progressor UV-tumor 2237 failed to elicit detectable levels of progressor tumor-specific Tc cells even as the tumors rejected. Following in vitro resensitization of spleen cells from either regressor or progressor tumor immune animals, the authors found NK-like lymphocytes with anti-tumor activity. As the authors had not detected cells with this activity in splenic lymphocyte preparations prior to in vitro resensitization, the authors examined lymphocytes from the local tumor environment during the course of progressor tumor rejection for this activity. This analysis revealed NK lymphocytes exhibiting significant levels of cytolytic activity against UV-tumors. These results implicate NK cells as potential effector cells in the rejection of progressor UV-tumors by immune animals, and suggests that these cells may be regulated by T lymphocytes.

  9. An activation-induced IL-15 isoform is a natural antagonist for IL-15 function.

    PubMed

    Zhao, Lei; Hu, Bo; Zhang, Yinsheng; Song, Yuan; Lin, Dandan; Liu, Yonghao; Mei, Yu; Sandikin, Dedy; Sun, Weiping; Zhuang, Min; Liu, Haiyan

    2016-01-01

    Interleukin 15 (IL-15) expression induces the secretion of inflammatory cytokines, inhibits the apoptosis of activated T cells and prolongs the survival of CD8(+) memory T cells. Here we identified an IL-15 isoform lacking exon-6, IL-15ΔE6, generated by alternative splicing events of activated immune cells, including macrophages and B cells. In vitro study showed that IL-15ΔE6 could antagonize IL-15-mediated T cell proliferation. The receptor binding assay revealed that IL-15ΔE6 could bind to IL-15Rα and interfere with the binding between IL-15 and IL-15Rα. Over-expression of IL-15ΔE6 in the murine EAE model ameliorated the EAE symptoms of the mice. The clinical scores were significantly lower in the mice expressing IL-15ΔE6 than the control mice and the mice expressing IL-15. The inflammation and demyelination of the EAE mice expressing IL-15ΔE6 were less severe than the control group. Furthermore, flow cytometry analysis demonstrated that IL-15ΔE6 expression reduced the percentages of inflammatory T cells in the spleen and spinal cord, and inhibited the infiltration of macrophages to the CNS. Our results demonstrated that IL-15ΔE6 could be induced during immune activation and function as a negative feedback mechanism to dampen IL-15-mediated inflammatory events. PMID:27166125

  10. Rapid, Concurrent Alterations in Pre- and Postsynaptic Structure Induced by Soluble Natural Amyloid-β Protein

    PubMed Central

    Calabrese, Barbara; Shaked, Gideon M; Tabarean, Iustin V; Braga, Julia; Koo, Edward H; Halpain, Shelley

    2008-01-01

    In Alzheimer’s disease increasing evidence attributes synaptic and cognitive deficits to soluble oligomers of amyloid β protein (Aβ), even prior to the accumulation of amyloid plaques, neurofibrillary tangles, and neuronal cell death. Here we show that within 1–2 hours picomolar concentrations of cell-derived, soluble Aβ induce specific alterations in pre- and postsynaptic morphology and connectivity in cultured hippocampal neurons. Clusters of presynaptic vesicle markers decreased in size and number at glutamatergic but not GABAergic terminals. Dendritic spines also decreased in number and became dysmorphic, as spine heads collapsed and/or extended long protrusions. Simultaneous time-lapse imaging of axon-dendrite pairs revealed that shrinking spines sometimes became disconnected from their presynaptic varicosity. Concomitantly, miniature synaptic potentials decreased in amplitude and frequency. Spine changes were prevented by blockers of nAChRs and NMDARs. Washout of Aβ within the first day reversed these spine changes. Further, spine changes reversed spontaneously by two days, because neurons acutely developed resistance to continuous Aβ exposure. Thus, rapid Aβ-induced synapse destabilization may underlie transient behavioral impairments in animal models, and early cognitive deficits in Alzheimer’s patients. PMID:17368908

  11. Cordycepin, a Natural Antineoplastic Agent, Induces Apoptosis of Breast Cancer Cells via Caspase-dependent Pathways.

    PubMed

    Wang, Di; Zhang, Yongfeng; Lu, Jiahui; Wang, Yang; Wang, Junyue; Meng, Qingfan; Lee, Robert J; Wang, Di; Teng, Lesheng

    2016-01-01

    Cordycepin, a major compound separated from Cordyceps sinensis, is known as a potential novel candidate for cancer therapy. Breast cancer, the most typical cancer diagnosed among women, remains a global health problem. In this study, the anti-breast cancer property of cordycepin and its underlying mechanisms was investigated. The direct effects of cordycepin on breast cancer cells both in in vitro and in vivo experiments were evaluated. Cordycepin exerted cytotoxicity in MCF-7 and MDA-MB-231 cells confirmed by reduced cell viability, inhibition of cell proliferation, enhanced lactate dehydrogenase release and reactive oxygen species accumulation, induced mitochondrial dysfunction and nuclear apoptosis in human breast cancer cells. Cordycepin increased the activation of pro-apoptotic proteins, including caspase-8, caspase-9, caspase-3 and Bax, and suppressed the expression of the anti-apoptotic protein, B-cell lymphoma 2 (Bcl-2). The inhibition on MCF-7-xenografted tumor growth in nude mice further confirmed cordycepin's anti-breast cancer effect. These aforementioned results reveal that cordycepin induces apoptosis in human breast cancer cells via caspase-dependent pathways. The data shed light on the possibility of cordycepin being a safe agent for breast cancer treatment. PMID:26996021

  12. A bifractal nature of reticular patterns induced by oxygen plasma on polymer films

    NASA Astrophysics Data System (ADS)

    Bae, Junwan; Lee, I. J.

    2015-05-01

    Plasma etching was demonstrated to be a promising tool for generating self-organized nano-patterns on various commercial films. Unfortunately, dynamic scaling approach toward fundamental understanding of the formation and growth of the plasma-induced nano-structure has not always been straightforward. The temporal evolution of self-aligned nano-patterns may often evolve with an additional scale-invariance, which leads to breakdown of the well-established dynamic scaling law. The concept of a bifractal interface is successfully applied to reticular patterns induced by oxygen plasma on the surface of polymer films. The reticular pattern, composed of nano-size self-aligned protuberances and underlying structure, develops two types of anomalous dynamic scaling characterized by super-roughening and intrinsic anomalous scaling, respectively. The diffusion and aggregation of short-cleaved chains under the plasma environment are responsible for the regular distribution of the nano-size protuberances. Remarkably, it is uncovered that the dynamic roughening of the underlying structure is governed by a relaxation mechanism described by the Edwards-Wilkinson universality class with a conservative noise. The evidence for the basic phase, characterized by the negative roughness and growth exponents, has been elusive since its first theoretical consideration more than two decades ago.

  13. A bifractal nature of reticular patterns induced by oxygen plasma on polymer films

    PubMed Central

    Bae, Junwan; Lee, I. J.

    2015-01-01

    Plasma etching was demonstrated to be a promising tool for generating self-organized nano-patterns on various commercial films. Unfortunately, dynamic scaling approach toward fundamental understanding of the formation and growth of the plasma-induced nano-structure has not always been straightforward. The temporal evolution of self-aligned nano-patterns may often evolve with an additional scale-invariance, which leads to breakdown of the well-established dynamic scaling law. The concept of a bifractal interface is successfully applied to reticular patterns induced by oxygen plasma on the surface of polymer films. The reticular pattern, composed of nano-size self-aligned protuberances and underlying structure, develops two types of anomalous dynamic scaling characterized by super-roughening and intrinsic anomalous scaling, respectively. The diffusion and aggregation of short-cleaved chains under the plasma environment are responsible for the regular distribution of the nano-size protuberances. Remarkably, it is uncovered that the dynamic roughening of the underlying structure is governed by a relaxation mechanism described by the Edwards-Wilkinson universality class with a conservative noise. The evidence for the basic phase, characterized by the negative roughness and growth exponents, has been elusive since its first theoretical consideration more than two decades ago. PMID:25997075

  14. Discriminating Mining Induced Seismicity from Natural Tectonic Earthquakes in the Wasatch Plateau Region of Central Utah

    NASA Astrophysics Data System (ADS)

    Stein, J. R.; Pankow, K. L.; Koper, K. D.; McCarter, M. K.

    2014-12-01

    On average, several hundred earthquakes are located each year within the Wasatch Plateau region of central Utah. This region includes the boundary between the relatively stable Colorado Plateau and the actively extending Basin and Range physiographic provinces. Earthquakes in this region tend to fall in the intermountain seismic belt (ISB), a continuous band of seismicity that extends from Montana to Arizona. While most of the earthquakes in the ISB are of tectonic origin, events in the Wasatch Plateau also include mining induced seismicity (MIS) from local underground coal mining operations. Using a catalog of 16,182 seismic events (-0.25 < M < 4.5) recorded from 1981 to 2011, we use double difference relocation and waveform cross correlation techniques to help discriminate between these two populations of events. Double difference relocation greatly improves the relative locations between the many events that occur in this area. From the relative relocations, spatial differences between event types are used to differentiate between shallow MIS and considerably deeper events associated with tectonic seismicity. Additionally, waveform cross-correlation is used to cluster events with similar waveforms—meaning that events in each cluster should have a similar source location and mechanism—in order to more finely group seismic events occurring in the Wasatch Plateau. The results of this study provide both an increased understanding of the influence mining induced seismicity has on the number of earthquakes detected within this region, as well as better constraints on the deeper tectonic structure.

  15. Impact-induced shock and the formation of natural quasicrystals in the early solar system.

    PubMed

    Hollister, Lincoln S; Bindi, Luca; Yao, Nan; Poirier, Gerald R; Andronicos, Christopher L; MacPherson, Glenn J; Lin, Chaney; Distler, Vadim V; Eddy, Michael P; Kostin, Alexander; Kryachko, Valery; Steinhardt, William M; Yudovskaya, Marina; Eiler, John M; Guan, Yunbin; Clarke, Jamil J; Steinhardt, Paul J

    2014-01-01

    The discovery of a natural quasicrystal, icosahedrite (Al63Cu24Fe13), accompanied by khatyrkite (CuAl2) and cupalite (CuAl) in the CV3 carbonaceous chondrite Khatyrka has posed a mystery as to what extraterrestrial processes led to the formation and preservation of these metal alloys. Here we present a range of evidence, including the discovery of high-pressure phases never observed before in a CV3 chondrite, indicating that an impact shock generated a heterogeneous distribution of pressures and temperatures in which some portions reached at least 5 GPa and 1,200 °C. The conditions were sufficient to melt Al-Cu-bearing minerals, which then rapidly solidified into icosahedrite and other Al-Cu metal phases. The meteorite also contains heretofore unobserved phases of iron-nickel and iron sulphide with substantial amounts of Al and Cu. The presence of these phases in Khatyrka provides further proof that the Al-Cu alloys are natural products of unusual processes that occurred in the early solar system. PMID:24925481

  16. Natural selection in utero induced by mass layoffs: the hCG evidence

    PubMed Central

    Catalano, Ralph; Margerison-Zilko, Claire; Goldman-Mellor, Sidra; Pearl, Michelle; Anderson, Elizabeth; Saxton, Katherine; Bruckner, Tim; Subbaraman, Meenakshi; Goodman, Julia; Epstein, Mollie; Currier, Robert; Kharrazi, Martin

    2012-01-01

    Evolutionary theory, when coupled with research from epidemiology, demography, and population endocrinology, suggests that contracting economies affect the fitness and health of human populations via natural selection in utero. We know, for example, that fetal death increases more among males than females when the economy unexpectedly contracts; that unexpected economic contraction predicts low secondary sex ratios; and that males from low sex ratio birth cohorts live, on average, longer than those from high sex ratio cohorts. We also know that low levels of human chorionic gonadotropin (i.e., hCG) measured in the serum of pregnant women predict fetal death. We do not, however, know whether male survivors of conception cohorts subjected to contracting economies exhibit, as theory predicts, higher hCG than those from other cohorts. We show, in 71 monthly conception cohorts including nearly two million California births, that they do. We thereby add to the literature suggesting that the economy, a phenomenon over which we collectively exercise at least some control, affects population health. Our findings imply that the effect arises via natural selection – a mechanism we largely ignore when attempting to explain, or alter, how collective choice affects our biology. PMID:23346225

  17. Investigating natural organic carbon removal and structural alteration induced by pulsed ultrasound.

    PubMed

    Al-Juboori, Raed A; Yusaf, Talal; Aravinthan, Vasantha; Bowtell, Leslie

    2016-01-15

    The application of pulsed ultrasound for DOC removal from natural water samples has been thoroughly investigated in this work. Natural water samples were treated with ultrasound at power levels of 48 and 84 W with treatment times of 5 and 15 min. Chemical fractionation was conducted for both untreated and treated samples to clearly identify the change in DOC structure caused by ultrasonic treatments. Statistical analyses applying 2(3) factorial design were performed to study the behaviour of the response (i.e. DOC removal) under different operating conditions. Overall, ultrasonic treatments resulted in DOC removal of 7-15% depending on the applied operating conditions. The treated water had high microbial loading that interfered with DOC removal due primarily to the release of microbial products when exposed to ultrasound. Pulse ultrasound was found to be more effective than the continuous mode for DOC removal at the same effective power level. A regression model was developed and tested for DOC removal prediction. The model was adequate in predicting DOC removal with a maximum deviation from the experimental data of <11%. Pulsed ultrasound at low power levels and short treatment times was found to be the most energy efficient treatment for DOC removal. PMID:26473704

  18. Study on the desorption yield for natural botanic sample induced by energetic heavy ions

    NASA Astrophysics Data System (ADS)

    Xue, J. M.; Wang, Y. G.; Du, G. H.; Yan, S.; Zhao, W. J.

    2002-12-01

    The dependence of desorption yield for the natural botanic sample bombarded with heavy ion on the electronic stopping power ( Se) and dose has been measured by weighing sample mass before and after irradiation. Primary ions including 50 keV N +, 1.5 MeV F +, 3.0 MeV F 2+, 4.0 MeV F 2+ and 3.0 MeV Si 2+ were used in the experiment. Three megaelectron volts of F 2+ with doses ranging from 4×10 15 to 4×10 16 ions/cm 2 were used in order to investigate the influence of ion dose. A mass spectrum from the sample bombarded with 3 MeV Si 2+ was also taken for a better understanding of the desorption process. Results show that the natural botanic sample is very easily to be desorpted. The yield of MeV heavy ions can be as high as thousands CH 2O/ion, and significantly depends on both the Se and dose. The measured yields increase quickly with Se, but drop down with increasing ion dose. These results fit roughly with the prediction of the pressure pulse model.

  19. Monitoring natural and anthropogenic induced variations in water availability across Africa

    NASA Astrophysics Data System (ADS)

    Ahmed, M.; Sultan, M.; Wahr, J. M.; Yan, E.

    2014-12-01

    Africa, the second-driest continent in the world after Australia, is one of the most vulnerable continents to climate change. Understanding the impacts of climatic and anthropogenic factors on Africa's hydrologic systems is vital for the assessment and utilization of Africa's water resources. In this study, we utilize the Gravity Recovery and Climate Experiment (GRACE) and land surface models (LSM; GLDAS and CLM4.5) in conjunction with other readily-available temporal climatic and remote sensing, geological and hydrological datasets for monitoring the spatial and temporal trends in Terrestrial Water Storage (TWS) over a time period of 10 years (01/2003-12/2012) over the African continent and to investigate the nature (e.g., climatic and/or human pressures-related) of, and the controlling factors causing, these variations. Spatial and temporal (i.e., time series analysis) correlations of the trends extracted from GRACE-derived (TWSGRACE) and LSM-derived (TWSLSM) TWS indicate the following: (1) Large (≥ 90 % by area) sectors of Africa are undergoing statistically significant TWSGRACE and TWSLSM variations due to natural and anthropogenic causes; (2) a general correspondence between TWSGRACE and TWSLSM over areas (e.g., Niger and Mozambique NE basins in eastern and western Africa) largely controlled by natural (i.e., increase/decrease in precipitation and/or temperature) causes; (3) discrepancies are observed over areas that witnessed extensive anthropogenic effects measured by TWSGRACE but unaccounted for by TWSLSM. Examples include: (a) strong (compared to that observed by TWSLSM) negative TWSGRACE trends were observed over areas that witnessed heavy groundwater extraction (e.g., Western, Desert, Egypt); (b) strong (compared to that observed by TWSLSM) positive TWSGRACE over Lake Volta reservoir; and (c) strong (compared to that observed by TWSLSM) negative trends over areas undergoing heavy deforestation (e.g., northern and NW Congo Basin); (4) additional

  20. Natural and human-induced sinkhole hazards in Saudi Arabia: distribution, investigation, causes and impacts

    NASA Astrophysics Data System (ADS)

    Youssef, Ahmed M.; Al-Harbi, Hasan M.; Gutiérrez, Francisco; Zabramwi, Yasser A.; Bulkhi, Ali B.; Zahrani, Saeed A.; Bahamil, Alaa M.; Zahrani, Ahmed J.; Otaibi, Zaam A.; El-Haddad, Bosy A.

    2016-05-01

    Approximately 60 % of the 2,150,000 km2 area of Saudi Arabia is underlain by soluble sediments (carbonate and evaporite rock formations, salt diapirs, sabkha deposits). Despite its hyper-arid climate, a wide variety of recent sinkholes have been reported in numerous areas, involving significant property losses. Human activities, most notably groundwater extraction, have induced unstable conditions on pre-existing cavities. This work provides an overview of the sinkhole hazard in Saudi Arabia, a scarcely explored topic. It identifies the main karst formations and the distribution of the most problematic sinkhole areas, illustrated through several case studies covering the wide spectrum of subsidence mechanisms. Some of the main investigation methods are presented through selected examples, including remote sensing, trenching and geophysics. Based on the available data, the main causal factors are identified and further actions that should be undertaken to better assess and manage the risk are discussed.

  1. Toxic hepatitis induced by Gymnema sylvestre, a natural remedy for type 2 diabetes mellitus.

    PubMed

    Shiyovich, Arthur; Sztarkier, Ignacio; Nesher, Lior

    2010-12-01

    Toxic hepatitis or drug-induced liver injury (DILI) encompasses a spectrum of conditions ranging from mild biochemical abnormalities to acute liver failure. Recent studies report that 35% to 48% of patients with diabetes use some form of complementary and alternative medical therapy. Moreover, >800 plants have been traditionally used for the treatment of diabetes. Despite this widespread use, only few were supported by rigorous clinical evidence. Gymnema sylvestre, also known as gurmar (sugar destroyer in Hindi), is a plant considered to be with potent antidiabetic effects and, hence, widely used in folk, ayurvedic and homeopathic systems in medicine. The authors were unable to find previous reports associating G sylvestre to liver injury. Herein, the authors report a case of DILI in a patient who was treated with G sylvestre for diabetes mellitus and review the literature to suggest possible mechanisms that led to this acute condition. PMID:20856101

  2. Natural and human-induced sinkhole hazards in Saudi Arabia: distribution, investigation, causes and impacts

    NASA Astrophysics Data System (ADS)

    Youssef, Ahmed M.; Al-Harbi, Hasan M.; Gutiérrez, Francisco; Zabramwi, Yasser A.; Bulkhi, Ali B.; Zahrani, Saeed A.; Bahamil, Alaa M.; Zahrani, Ahmed J.; Otaibi, Zaam A.; El-Haddad, Bosy A.

    2015-11-01

    Approximately 60 % of the 2,150,000 km2 area of Saudi Arabia is underlain by soluble sediments (carbonate and evaporite rock formations, salt diapirs, sabkha deposits). Despite its hyper-arid climate, a wide variety of recent sinkholes have been reported in numerous areas, involving significant property losses. Human activities, most notably groundwater extraction, have induced unstable conditions on pre-existing cavities. This work provides an overview of the sinkhole hazard in Saudi Arabia, a scarcely explored topic. It identifies the main karst formations and the distribution of the most problematic sinkhole areas, illustrated through several case studies covering the wide spectrum of subsidence mechanisms. Some of the main investigation methods are presented through selected examples, including remote sensing, trenching and geophysics. Based on the available data, the main causal factors are identified and further actions that should be undertaken to better assess and manage the risk are discussed.

  3. Mouse and pig models for studies of natural and vaccine-induced immunity to Bordetella pertussis.

    PubMed

    Mills, Kingston H G; Gerdts, Volker

    2014-04-01

    The increasing incidence of whooping cough in many developed countries has been linked with waning immunity induced after immunization with acellular pertussis (aP) vaccines. The rational design of an improved aP vaccine requires a full understanding of the mechanism of protective immunity and preclinical studies in animal models. Infection of mice and pigs with Bordetella pertussis has many features of the infection seen in humans and has already provided valuable information on the roles of innate and adaptive immune responses in protection. Recent findings in these models have already indicated that it may be possible to develop an improved aP vaccine based on a formulation that includes a Toll-like receptor agonist as an adjuvant. PMID:24626866

  4. A 107-year-old coral from Florida Bay: barometer of natural and man- induced catastrophes?

    USGS Publications Warehouse

    Hudson, J.H.; Powell, G.V.N.; Robblee, M.B.; Smith, T. J., III

    1989-01-01

    The 107-yr growth history of a massive coral Solenastrea bournoni from Florida Bay was reconstructed with X-ray imagery from a single 4 in. diameter (10 cm) core that penetrated the exact epicenter of the 95.3 cm high colony. Growth increments totalled 952.9 mm, averaging 8.9 mm/yr over the life of the coral. Growth rate trends in the Florida Bay coral were compared to those in a Montastraea annularis of similar age from a nearby patch reef on the Atlantic Ocean side of the Florida Keys. It was concluded that growth rate, at least in these specimens, is a questionable indicator of past hurricanes and freezes. There does appear to be, however, a possible cause-and-effect relationship between major man-induced environmental perturbations and a prolonged reduction in growth rate in each coral's growth record. -from Authors

  5. Cytosine Methylation Alteration in Natural Populations of Leymus chinensis Induced by Multiple Abiotic Stresses

    PubMed Central

    Yu, Yingjie; Yang, Xuejiao; Wang, Huaying; Shi, Fengxue; Liu, Ying; Liu, Jushan; Li, Linfeng; Wang, Deli; Liu, Bao

    2013-01-01

    Background Human activity has a profound effect on the global environment and caused frequent occurrence of climatic fluctuations. To survive, plants need to adapt to the changing environmental conditions through altering their morphological and physiological traits. One known mechanism for phenotypic innovation to be achieved is environment-induced rapid yet inheritable epigenetic changes. Therefore, the use of molecular techniques to address the epigenetic mechanisms underpinning stress adaptation in plants is an important and challenging topic in biological research. In this study, we investigated the impact of warming, nitrogen (N) addition, and warming+nitrogen (N) addition stresses on the cytosine methylation status of Leymus chinensis Tzvel. at the population level by using the amplified fragment length polymorphism (AFLP), methylation-sensitive amplified polymorphism (MSAP) and retrotransposon based sequence-specific amplification polymorphism (SSAP) techniques. Methodology/Principal Findings Our results showed that, although the percentages of cytosine methylation changes in SSAP are significantly higher than those in MSAP, all the treatment groups showed similar alteration patterns of hypermethylation and hypomethylation. It meant that the abiotic stresses have induced the alterations in cytosine methylation patterns, and the levels of cytosine methylation changes around the transposable element are higher than the other genomic regions. In addition, the identification and analysis of differentially methylated loci (DML) indicated that the abiotic stresses have also caused targeted methylation changes at specific loci and these DML might have contributed to the capability of plants in adaptation to the abiotic stresses. Conclusions/Significance Our results demonstrated that abiotic stresses related to global warming and nitrogen deposition readily evoke alterations of cytosine methylation, and which may provide a molecular basis for rapid adaptation by

  6. Molecular nature of ultraviolet B light-induced deletions in the murine epidermis.

    PubMed

    Horiguchi, M; Masumura, K I; Ikehata, H; Ono, T; Kanke, Y; Nohmi, T

    2001-05-15

    Depletion of the stratospheric ozone layer leads to an increase in ambient UV loads, which are expected to raise skin cancer incidences. Tumor development in the skin could be a multistep process in which various genetic alterations, such as point mutations and deletions, occur successively. Here, we demonstrate that UVB irradiation efficiently induces deletions in the epidermis using a novel transgenic mouse, gpt delta. In this mouse model, deletions in lambda DNA integrated in the chromosome are preferentially selected as Spi(-) (sensitive to P2 interference) phages, which can then be subjected to molecular analysis. The mice were exposed to UVB at single doses of 0.3, 0.5, 1.0, 1.5, and 2.0 kJ/m(2). After 4 weeks, lambda phage was rescued from the genomic DNA of the epidermis by in vitro packaging reactions. The mutant frequencies of Spi(-) with large deletions in the epidermis increased >15-fold at a UVB dose of 0.5 kJ/m(2) over the control. Molecular sizes of most of the large deletions were >1000 bp. More than one-half of the large deletions occurred between short direct-repeat sequences from 1 to 6 bp, and the remainder had flush ends. In the unirradiated mouse, almost all of the Spi(-) mutants were 1-bp frameshifts in runs of identical bases. These results suggest that UVB irradiation induces deletions in the murine epidermis, and most of the deletions are generated through end-joining of double strand breaks in DNA. PMID:11358805

  7. Staphylococcal Phenotypes Induced by Naturally Occurring and Synthetic Membrane-Interactive Polyphenolic β-Lactam Resistance Modifiers

    PubMed Central

    Palacios, Lucia; Rosado, Helena; Micol, Vicente; Rosato, Adriana E.; Bernal, Patricia; Arroyo, Raquel; Grounds, Helen; Anderson, James C.; Stabler, Richard A.; Taylor, Peter W.

    2014-01-01

    Galloyl catechins, in particular (-)-epicatechin gallate (ECg), have the capacity to abrogate β-lactam resistance in methicillin-resistant strains of Staphylococcus aureus (MRSA); they also prevent biofilm formation, reduce the secretion of a large proportion of the exoproteome and induce profound changes to cell morphology. Current evidence suggests that these reversible phenotypic traits result from their intercalation into the bacterial cytoplasmic membrane. We have endeavoured to potentiate the capacity of ECg to modify the MRSA phenotype by stepwise removal of hydroxyl groups from the B-ring pharmacophore and the A:C fused ring system of the naturally occurring molecule. ECg binds rapidly to the membrane, inducing up-regulation of genes responsible for protection against cell wall stress and maintenance of membrane integrity and function. Studies with artificial membranes modelled on the lipid composition of the staphylococcal bilayer indicated that ECg adopts a position deep within the lipid palisade, eliciting major alterations in the thermotropic behaviour of the bilayer. The non-galloylated homolog (-)-epicatechin enhanced ECg-mediated effects by facilitating entry of ECg molecules into the membrane. ECg analogs with unnatural B-ring hydroxylation patterns induced higher levels of gene expression and more profound changes to MRSA membrane fluidity than ECg but adopted a more superficial location within the bilayer. ECg possessed a high affinity for the positively charged staphylococcal membrane and induced changes to the biophysical properties of the bilayer that are likely to account for its capacity to disperse the cell wall biosynthetic machinery responsible for β-lactam resistance. The ability to enhance these properties by chemical modification of ECg raises the possibility that more potent analogs could be developed for clinical evaluation. PMID:24699700

  8. Levo-tetrahydropalmatine, a natural, mixed dopamine receptor antagonist, inhibits methamphetamine self-administration and methamphetamine-induced reinstatement.

    PubMed

    Gong, Xiaokang; Yue, Kai; Ma, Baomiao; Xing, Junqiao; Gan, Yongping; Wang, Daisong; Jin, Guozhang; Li, Chaoying

    2016-05-01

    Despite the high prevalence of methamphetamine (METH) use, no FDA-approved pharmacological treatment is currently available for individuals with a METH addiction. Levo-tetrahydropalmatine (l-THP) is an alkaloid substance derived from corydalis and stephania that has been used in traditional Asian medicine for its analgesic, sedative and hypnotic properties. Previous pharmacological studies of l-THP indicated that it not only binds to D1 and D2 receptors but also has a low affinity for D3 receptors and may function as an antagonist. The unique pharmacological profile of l-THP suggests that it may have potential therapeutic effects on drug addiction; however, the effects of l-THP in individuals with METH addictions are largely unknown. In this study, we investigated the effects of l-THP on METH self-administration and METH-induced reinstatement. In our experiments, l-THP (1.25, 2.50 and 5.00 mg/kg, i.p.) decreased METH self-administration under the fixed-ratio 1 schedule. l-THP (2.50 and 5.00 mg/kg, i.p) also prevented the METH-induced reinstatement of METH-seeking behaviors. Interestingly, l-THP (1.25 and 2.50mg/kg, i.p) did not affect locomotor activity following METH injection (1mg/kg) suggesting that the observed effects of l-THP (2.50mg/kg) on METH-induced reinstatement were not due to motor impairments. Thus, l-THP (a natural, mixed dopamine (DA) receptor antagonist) attenuates METH self-administration and METH-induced reinstatement. PMID:26806555

  9. Nonspecific inhibition of alloantigen-induced proliferation by bone marrow natural regulatory cells

    SciTech Connect

    Dorshkind, K.; Rosse, C.

    1981-03-01

    We have previously reported that a lymphocyte-enriched fraction ofmurine bone marrow (BML) contains natural regulatory cells (NRC) that can inhibit in vitro proliferative and cytotoxic responses to alloantigens on a dose-dependent basis. In view of the potential importance of these cells to the outcome of bone marrow transplantation, we have undertaken a series of studies designed to inestigate the properties of the effector cell(s). Since clinical and experimental bone marrow transplantation is often performed by inoculating histoincompatible marrow into irradiated hosts, we have investigated the effects of irradiation on NRC and their ability to function across major and minor histocompatibility barriers. In this brief communication, we report that NRC can nonspecifically inhibit cellular immune responses across histocompatibility barriers and are not affected by high doses of irraddiation. In addition, we report that NRC are not T or B lymphocytes.

  10. MAPPING INDUCED POLARIZATION WITH NATURAL ELECTROMAGNETIC FIELDS FOR EXPLORATION AND RESOURCES CHARACTERIZATION BY THE MINING INDUSTRY

    SciTech Connect

    Edward Nichols

    2001-07-11

    In this quarter we completed the manufacture and bench testing of the first prototype of the MT-24/LF system to be used in the natural IP survey. The MT-24/LF will dramatically reduce field costs by simplifying field operations through the use of high accuracy GPS synchronization between wide band high accuracy (24 bit) autonomous recording systems. The simplification of field operations comes about from the elimination of the need for long lengths of telemetry cable and also from the elimination of trained operators for field data acquisition. Instead, all data is now synchronized by GPS and recorded to compact Flash media which is quickly and efficiently recovered and brought back to base for processing.