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Sample records for multichannel carotenoid deactivation

  1. Multichannel carotenoid deactivation in photosynthetic light harvesting as identified by an evolutionary target analysis.

    PubMed

    Wohlleben, Wendel; Buckup, Tiago; Herek, Jennifer L; Cogdell, Richard J; Motzkus, Marcus

    2003-07-01

    A new channel of excitation energy deactivation in bacterial light harvesting was recently discovered, which leads to carotenoid triplet population on an ultrafast timescale. Here we show that this mechanism is also active in LH2 of Rhodopseudomonas acidophila through analysis of transient absorption data with an evolutionary target analysis. The algorithm offers flexible testing of kinetic network models with low a priori knowledge requirements. It applies universally to the simultaneous fitting of target state spectra and rate constants to time-wavelength-resolved data. Our best-fit model reproduces correctly the well-known cooling and decay behavior in the S(1) band, but necessitates an additional, clearly distinct singlet state that does not exchange with S(1), promotes ultrafast triplet population and participates in photosynthetic energy transfer.

  2. Carotenoids

    USDA-ARS?s Scientific Manuscript database

    This short article indicated that greater understanding of the biological functions of carotenoids mediated via their oxidative metabolites through their effects on these important cellular pathways and molecular targets, as well as their significance to cancer prevention, is needed. In considering ...

  3. Mechanism of deactivation of triplet-excited riboflavin by ascorbate, carotenoids, and tocopherols in homogeneous and heterogeneous aqueous food model systems.

    PubMed

    Cardoso, Daniel R; Olsen, Karsten; Skibsted, Leif H

    2007-07-25

    Tocopherols (alpha, beta, gamma, and delta) and Trolox were found to deactivate triplet-excited riboflavin in homogeneous aqueous solution (7:3 v/v tert-butanol/water) with second-order reaction rates close to diffusion control [k2 between 4.8 x 10(8) (delta-tocopherol) and 6.2 x 10(8) L mol(-1) s(-1) (Trolox) at 24.0 +/- 0.2 degrees C] as determined by laser flash photolysis transient absorption spectroscopy. In aqueous buffer (pH 6.4) the rate constant for Trolox was 2.6 x 10(9) L mol(-1) s1 and comparable to the rate constant found for ascorbate (2.0 x 10(9) L mol(-1) s(-1)). The deactivation rate constant was found to be inferior in heterogeneous systems as shown for alpha-tocopherol and Trolox in aqueous Tween-20 emulsion (approximately by a factor of 4 compared to 7:3 v/v tert-butanol/water). Neither beta-carotene (7:3 v/v tert-butanol/water and Tween-20 emulsion), lycopene (7:3 v/v tert-butanol/water), nor crocin (aqueous buffer at pH 6.4, 7:3 v/v tert-butanol/water, and Tween-20 emulsion) showed any quenching on the triplet excited state of riboflavin. Therefore, all carotenoids seem to reduce the formation of triplet-excited riboflavin through an inner-filter effect. Activation parameters were based on the temperature dependence of the triplet-excited deactivation between 15 and 35 degrees C, and the isokinetic behavior, which was found to include purine derivatives previously studied, confirms a common deactivation mechanism with a bimolecular diffusion-controlled encounter with electron (or hydrogen atom) transfer as rate-determining step. DeltaH for deactivation by ascorbic acid, Trolox, and homologue tocopherols (ranging from 18 kJ mol(-1) for Trolox in Tween-20 emulsion to 184 kJ mol(-1) for ascorbic acid in aqueous buffer at pH 6.4) showed a linear dependence on DeltaS (ranging from -19 J mol(-1) K(-1) for Trolox in aqueous buffer at pH 6.4 to +550 J mol(-1) K(-1) for ascorbic acid in aqueous buffer pH 6.4). Among photooxidation products from the

  4. An unusual pathway of excitation energy deactivation in carotenoids: singlet-to-triplet conversion on an ultrafast timescale in a photosynthetic antenna.

    PubMed

    Gradinaru, C C; Kennis, J T; Papagiannakis, E; van Stokkum, I H; Cogdell, R J; Fleming, G R; Niederman, R A; van Grondelle, R

    2001-02-27

    Carotenoids are important biomolecules that are ubiquitous in nature and find widespread application in medicine. In photosynthesis, they have a large role in light harvesting (LH) and photoprotection. They exert their LH function by donating their excited singlet state to nearby (bacterio)chlorophyll molecules. In photosynthetic bacteria, the efficiency of this energy transfer process can be as low as 30%. Here, we present evidence that an unusual pathway of excited state relaxation in carotenoids underlies this poor LH function, by which carotenoid triplet states are generated directly from carotenoid singlet states. This pathway, operative on a femtosecond and picosecond timescale, involves an intermediate state, which we identify as a new, hitherto uncharacterized carotenoid singlet excited state. In LH complex-bound carotenoids, this state is the precursor on the reaction pathway to the triplet state, whereas in extracted carotenoids in solution, this state returns to the singlet ground state without forming any triplets. We discuss the possible identity of this excited state and argue that fission of the singlet state into a pair of triplet states on individual carotenoid molecules constitutes the mechanism by which the triplets are generated. This is, to our knowledge, the first ever direct observation of a singlet-to-triplet conversion process on an ultrafast timescale in a photosynthetic antenna.

  5. LBR deactivation information exchange

    SciTech Connect

    Guttenberg, S.

    1998-05-15

    This report contains vugraphs of presentations given at the meeting. The topics covered include the following: FFTF Deactivation Strategy; Sodium Drain and Disposition; Sodium Processing; and Fuel Storage and Disposition.

  6. Mission analysis report - deactivation facilities at Hanford

    SciTech Connect

    Lund, D.P.

    1996-09-27

    This document examines the portion of the Hanford Site Cleanup Mission that deals with facility deactivation. How facilities get identified for deactivation, how they enter EM-60 for deactivation, programmatic alternatives to perform facility deactivation, the deactivation process itself, key requirements and objectives associated with the deactivation process, and deactivation planning are discussed.

  7. Deactivation of Building 7602

    SciTech Connect

    Yook, H.R.; Barnett, J.R.; Collins, T.L.

    1995-10-01

    The Department of Energy (DOE) has sponsored research and development programs in Building 7602 at Oak Ridge National Laboratory (ORNL) since 1984. This work focused on development of advanced technology for processing nuclear fuels. Building 7602 was used for engineering-scale tests using depleted and natural uranium to simulate the nuclear fuel. In April 1994 the DOE Office of Nuclear Energy (NE) sent supplemental FY 1994 guidance to ORNL stating that in FY 1995 and beyond, Building 7602 is considered surplus to NE programs and missions and shall be shut down (deactivated) and maintained in a radiologically and industrially safe condition with minimal surveillance and maintenance (S&M). DOE-NE subsequently provided FY 1995 funding to support the deactivation activities. Deactivation of Building 7602 was initiated on October 1, 1994. The principal activity during the first quarter of FY 1995 was removal of process materials (chemicals and uranium) from the systems. The process systems were operated to achieve chemical solution concentrations needed for reuse or disposal of the solutions prior to removal of the materials from the systems. During this phase of deactivation the process materials processed and removed were: (1) Uranyl nitrate solution 30,178 L containing 4490 kg of uranium; (2) Nitric acid (neutralized) 9850 L containing less than 0.013 kg of uranium; (3) Organic solution 3346 L containing 265 kg of uranium; (4) Uranium oxide powder 95 kg; and (5) Miscellaneous chemicals. At the end of December 1994, the process systems and control systems were shut down and deactivated. Disposition of the process materials removed from the process systems in Building 7602 proved to be the most difficult part of the deactivation. An operational stand down and funding reductions at Y-12 prevented planned conversion of the uranyl nitrate solution to depleted uranium oxide powder. This led to disposal of the uranyl nitrate solution as waste.

  8. Deactivating the Writing Program.

    ERIC Educational Resources Information Center

    Strickland, James

    A written language learner must be given an environment that enables or fosters writing development. Unfortunately, the typical system of education and the learning strategies that are taught are at times the very things that deactivate, frustrate, and even pervert the writing program. In fact, some of the rules that student writers respond to are…

  9. PFP deactivation project management plan

    SciTech Connect

    Bogen, D.M.

    1997-07-28

    This document identifies the overall approach for deactivation of the Plutonium Finishing Plant (PFP) Complex, excluding the vaults, and includes a draft set of End Point Criteria for all buildings being deactivated.

  10. MULTICHANNEL ANALYZER

    DOEpatents

    Kelley, G.G.

    1959-11-10

    A multichannel pulse analyzer having several window amplifiers, each amplifier serving one group of channels, with a single fast pulse-lengthener and a single novel interrogation circuit serving all channels is described. A pulse followed too closely timewise by another pulse is disregarded by the interrogation circuit to prevent errors due to pulse pileup. The window amplifiers are connected to the pulse lengthener output, rather than the linear amplifier output, so need not have the fast response characteristic formerly required.

  11. Deactivation of cellulases by phenols

    USDA-ARS?s Scientific Manuscript database

    Pretreatment of lignocellulosic materials may result in the release of inhibitors and deactivators of cellulose enzyme hydrolysis. We report the identification of phenols with major inhibition and/or deactivation effect on enzymes used for conversion of cellulose to ethanol. The inhibition effects w...

  12. Carotenoids in marine animals.

    PubMed

    Maoka, Takashi

    2011-02-22

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade.

  13. Carotenoids in Marine Animals

    PubMed Central

    Maoka, Takashi

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade. PMID:21566799

  14. Carotenoid-Protein Interactions

    NASA Astrophysics Data System (ADS)

    Britton, George; Helliwell, John R.

    Chapter 5 shows that the aggregation of carotenoid molecules can have a profound effect on their properties and hence their functioning in biological systems. Another important influence is the interaction between carotenoids and other molecules. The way that interactions of carotenoids with lipid bilayers influence the structure and properties of membranes and membrane-asociated processes is discussed in Chapter 10, and the aggregation of carotenoid molecules within the bilayers in Chapter 5. Of particular importance, though, are interactions between carotenoids and proteins. These allow the hydrophobic carotenoids to be transported, to exist, and to function in an aqueous environment. In some cases they may modify strongly the light-absorption properties and hence the colour and photochemistry of the carotenoids.

  15. Nanotube-assisted protein deactivation

    NASA Astrophysics Data System (ADS)

    Joshi, Amit; Punyani, Supriya; Bale, Shyam Sundhar; Yang, Hoichang; Borca-Tasciuc, Theodorian; Kane, Ravi S.

    2008-01-01

    Conjugating proteins onto carbon nanotubes has numerous applications in biosensing, imaging and cellular delivery. However, remotely controlling the activity of proteins in these conjugates has never been demonstrated. Here we show that upon near-infrared irradiation, carbon nanotubes mediate the selective deactivation of proteins in situ by photochemical effects. We designed nanotube-peptide conjugates to selectively destroy the anthrax toxin, and also optically transparent coatings that can self-clean following either visible or near-infrared irradiation. Nanotube-assisted protein deactivation may be broadly applicable to the selective destruction of pathogens and cells, and will have applications ranging from antifouling coatings to functional proteomics.

  16. Carotenoid metabolism in plants.

    PubMed

    Nisar, Nazia; Li, Li; Lu, Shan; Khin, Nay Chi; Pogson, Barry J

    2015-01-01

    Carotenoids are mostly C40 terpenoids, a class of hydrocarbons that participate in various biological processes in plants, such as photosynthesis, photomorphogenesis, photoprotection, and development. Carotenoids also serve as precursors for two plant hormones and a diverse set of apocarotenoids. They are colorants and critical components of the human diet as antioxidants and provitamin A. In this review, we summarize current knowledge of the genes and enzymes involved in carotenoid metabolism and describe recent progress in understanding the regulatory mechanisms underlying carotenoid accumulation. The importance of the specific location of carotenoid enzyme metabolons and plastid types as well as of carotenoid-derived signals is discussed. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  17. Family Mode Deactivation Therapy Results and Implications

    ERIC Educational Resources Information Center

    Apsche, Jack A.; Bass, Christopher K.

    2006-01-01

    This article highlights the inclusion of Mode Deactivation Therapy as a treatment modality for families in crisis. As an empirically validated treatment, Mode Deactivation Therapy has been effective in treating a wide variety of psychological issues. Mode Deactivation Therapy, (MDT) was developed to treat adolescents with disorders of conduct…

  18. Encapsulation of Carotenoids

    NASA Astrophysics Data System (ADS)

    Ribeiro, Henelyta S.; Schuchmann, Heike P.; Engel, Robert; Walz, Elke; Briviba, Karlis

    Carotenoids are natural pigments, which are synthesized by microorganisms and plants. More than 600 naturally occurring carotenoids have been found in the nature. The main sources of carotenoids are fruits, vegetables, leaves, peppers, and certain types of fishes, sea foods, and birds. Carotenoids may protect cells against photosensitization and work as light-absorbing pigments during photosynthesis. Some carotenoids may inhibit the destructive effect of reactive oxygen species. Due to the antioxidative properties of carotenoids, many investigations regarding their protective effects against cardiovascular diseases and certain types of cancers, as well as other degenerative illnesses, have been carried out in the last years (Briviba et al. 2004; Krinsky et al. 2004; Kirsh et al. 2006). A diet rich in carotenoids may also contribute to photoprotection against UV radiation (Stahl et al. 2006). In vitro studies have shown that carotenoids such as β-cryptoxanthin and lycopene stimulate bone formation and mineralization. The results may be related to prevention of osteoporosis (Kim et al. 2003; Yamaguchi and Uchiyama 2003; 2004; Yamaguchi et al. 2005).

  19. Carotenoid metabolism in plants

    USDA-ARS?s Scientific Manuscript database

    Carotenoids are mostly C40 terpenoids, a class of hydrocarbons that participate in various biological processes in plants, such as photosynthesis, photomorphogenesis, photoprotection, and development. Carotenoids also serve as precursors for two plant hormones and a diverse set of apocarotenoids. Th...

  20. Carotenoids in Microalgae.

    PubMed

    Henríquez, Vitalia; Escobar, Carolina; Galarza, Janeth; Gimpel, Javier

    Carotenoids are a class of isoprenoids synthesized by all photosynthetic organisms as well as by some non-photosynthetic bacteria and fungi with broad applications in food, feed and cosmetics, and also in the nutraceutical and pharmaceutical industries. Microalgae represent an important source of high-value products, which include carotenoids, among others. Carotenoids play key roles in light harvesting and energy transfer during photosynthesis and in the protection of the photosynthetic apparatus against photooxidative damage. Carotenoids are generally divided into carotenes and xanthophyls, but accumulation in microalgae can also be classified as primary (essential for survival) and secondary (by exposure to specific stimuli).In this chapter, we outline the high value carotenoids produced by commercially important microalgae, their production pathways, the improved production rates that can be achieved by genetic engineering as well as their biotechnological applications.

  1. Carotenoids of biotechnological importance.

    PubMed

    Sandmann, Gerhard

    2015-01-01

    Carotenoids are natural pigments with antioxidative functions that protect against oxidative stress. They are essential for humans and must be supplied through the diet. Carotenoids are the precursors for the visual pigment rhodopsin, and lutein and zeaxanthin must be accumulated in the yellow eye spot to protect the retina from excess light and ultraviolet damage. There is a global market for carotenoids as food colorants, animal feed, and nutraceuticals. Some carotenoids are chemically synthesized, whereas others are from natural sources. Microbial mass production systems of industrial interest for carotenoids are in use, and new ones are being developed by metabolic pathway engineering of bacteria, fungi, and plants. Several examples will be highlighted in this chapter.

  2. Functions of Intact Carotenoids

    NASA Astrophysics Data System (ADS)

    Britton, George

    The traditional view that carotenoids are a class of plant pigments does not do justice to their versatility. This versatility will become clear from the overview of the biological roles of carotenoids, in animals and microorganisms as well as in plants, that is given in this Chapter. It has become customary and convenient to differentiate biological effects of carotenoids into functions, actions and associations [1]. `Functions' have been defined as effects or properties that are essential for the normal well-being of the organism. Biological responses that follow the administration of carotenoids in the diet or as supplements are considered as `actions'. When an effect is seen but a causal relationship to the carotenoid has not been demonstrated, this is described as an `association'. The line between these is often not clear, however.

  3. Energy transfer, excited-state deactivation, and exciplex formation in artificial caroteno-phthalocyanine light-harvesting antennas.

    PubMed

    Berera, Rudi; van Stokkum, Ivo H M; Kodis, Gerdenis; Keirstead, Amy E; Pillai, Smitha; Herrero, Christian; Palacios, Rodrigo E; Vengris, Mikas; van Grondelle, Rienk; Gust, Devens; Moore, Thomas A; Moore, Ana L; Kennis, John T M

    2007-06-21

    We present results from transient absorption spectroscopy on a series of artificial light-harvesting dyads made up of a zinc phthalocyanine (Pc) covalently linked to carotenoids with 9, 10, or 11 conjugated carbon-carbon double bonds, referred to as dyads 1, 2, and 3, respectively. We assessed the energy transfer and excited-state deactivation pathways following excitation of the strongly allowed carotenoid S2 state as a function of the conjugation length. The S2 state rapidly relaxes to the S* and S1 states. In all systems we detected a new pathway of energy deactivation within the carotenoid manifold in which the S* state acts as an intermediate state in the S2-->S1 internal conversion pathway on a sub-picosecond time scale. In dyad 3, a novel type of collective carotenoid-Pc electronic state is observed that may correspond to a carotenoid excited state(s)-Pc Q exciplex. The exciplex is only observed upon direct carotenoid excitation and is nonfluorescent. In dyad 1, two carotenoid singlet excited states, S2 and S1, contribute to singlet-singlet energy transfer to Pc, making the process very efficient (>90%) while for dyads 2 and 3 the S1 energy transfer channel is precluded and only S2 is capable of transferring energy to Pc. In the latter two systems, the lifetime of the first singlet excited state of Pc is dramatically shortened compared to the 9 double-bond dyad and model Pc, indicating that the carotenoid acts as a strong quencher of the phthalocyanine excited-state energy.

  4. Nutrition Updates "Carotenoids and Health"

    USDA-ARS?s Scientific Manuscript database

    This symposium covered current topics in carotenoids and health, with special emphasis on healthy aging. The carotenoids covered were beta-carotene, lycopene, lutein, and beta-cryptoxanthin. Topics included the best food sources of these carotenoids, the importance of carotenoids as antioxidants an...

  5. Carotenoids and Photosynthesis.

    PubMed

    Hashimoto, Hideki; Uragami, Chiasa; Cogdell, Richard J

    2016-01-01

    Carotenoids are ubiquitous and essential pigments in photosynthesis. They absorb in the blue-green region of the solar spectrum and transfer the absorbed energy to (bacterio-)chlorophylls, and so expand the wavelength range of light that is able to drive photosynthesis. This is an example of singlet-singlet energy transfer, and so carotenoids serve to enhance the overall efficiency of photosynthetic light reactions. Carotenoids also act to protect photosynthetic organisms from the harmful effects of excess exposure to light. Triplet-triplet energy transfer from chlorophylls to carotenoids plays a key role in this photoprotective reaction. In the light-harvesting pigment-protein complexes from purple photosynthetic bacteria and chlorophytes, carotenoids have an additional role of structural stabilization of those complexes. In this article we review what is currently known about how carotenoids discharge these functions. The molecular architecture of photosynthetic systems will be outlined first to provide a basis from which to describe carotenoid photochemistry, which underlies most of their important functions in photosynthesis.

  6. Biomarkers of carotenoid bioavailability.

    PubMed

    Granado-Lorencio, F; Blanco-Navarro, I; Pérez-Sacristán, B; Hernández-Álvarez, E

    2017-09-01

    The use of biomarkers constitutes an essential tool to assess the bioavailability of carotenoids in humans. The present article aims to review several methodological, host-related and modulating factors relevant on assessing and interpreting carotenoid bioavailability. Markers for carotenoid bioavailability can be broadly divided into direct, biochemical or "analytical" markers and indirect, physiological or "functional" indicators. Analytical markers usually refer to biochemical indicators of intake and/or status (short and long term exposure) while functional measures may be interpreted in terms of cumulative exposure, biological effect (bioactivity) or modification of risk factors. Both types of markers display advantages and limitations but, in general, a relationship exists among the type of marker, the biological specimen needed and the time required for a change. Humans may absorb a wide range of carotenes and xanthophylls and many of them may be found in serum and tissues. However, under physiological conditions, the several classes of dietary carotenoids may behave unequally leading to a different systemic profile and, moreover, they can be selectively accumulated at target tissues. In addition, some carotenoids may be chemically and enzymatically modified generating different oxidative metabolites and apocarotenoids. Quantitatively, the biological response upon carotenoid intervention (assessed by analytical and functional markers) is highly variable but the use of large doses and long-term protocols may lead to saturation effects and the loss of linearity in the response. Also, despite carotenoid exposition is considered to be safe, markers of overexposure include clinical signs (i.e. carotenodermia, corneal rings and retinopathy) and biochemical indicators (hypercarotenemia, xanthophyll esters). Overall, both host-related and methodological factors may influence analytical and functional markers to assess carotenoid bioavailability although the

  7. BIOSYNTHESIS OF YEAST CAROTENOIDS

    PubMed Central

    Simpson, Kenneth L.; Nakayama, T. O. M.; Chichester, C. O.

    1964-01-01

    Simpson, Kenneth L. (University of California, Davis), T. O. M. Nakayama, and C. O. Chichester. Biosynthesis of yeast carotenoids. J. Bacteriol. 88:1688–1694. 1964.—The biosynthesis of carotenoids was followed in Rhodotorula glutinis and in a new strain, 62-506. The treatment of the growing cultures by methylheptenone, or ionone, vapors permitted observations of the intermediates in the biosynthetic pathway. On the basis of concentration changes and accumulation in blocked pathways, the sequence of carotenoid formation is postulated as phytoene, phytofluene, ζ-carotene, neurosporene, β-zeacarotene, γ-carotene, torulin, a C40 aldehyde, and torularhodin. Torulin and torularhodin were established as the main carotenoids of 62-506. PMID:14240958

  8. Multichannel sparse spike inversion

    NASA Astrophysics Data System (ADS)

    Pereg, Deborah; Cohen, Israel; Vassiliou, Anthony A.

    2017-10-01

    In this paper, we address the problem of sparse multichannel seismic deconvolution. We introduce multichannel sparse spike inversion as an iterative procedure, which deconvolves the seismic data and recovers the Earth two-dimensional reflectivity image, while taking into consideration the relations between spatially neighboring traces. We demonstrate the improved performance of the proposed algorithm and its robustness to noise, compared to competitive single-channel algorithm through simulations and real seismic data examples.

  9. Carotenoids in Photosynthesis

    NASA Astrophysics Data System (ADS)

    Telfer, Alison; Pascal, Andrew; Gall, Andrew

    Carotenoids are the secret ingredient in photosynthesis; masked by the green of chlorophyll, they are only revealed in their true glory during senescence, when chlorophyll is degraded to display the glowing colours of autumn. Yet the presence of these orange and yellow pigments is absolutely essential for oxygenic photosynthesis. This Chapter will explain the importance of carotenoids to oxygenic organisms and also their roles in anoxygenic photosynthetic bacteria, where their presence is often more obvious but in other ways may be less crucial.

  10. Catalyst deactivation in residue hydrocracking

    SciTech Connect

    Oballa, M.C.; Wong, C.; Krzywicki, A.

    1994-12-31

    The existence of a computer-controlled bench scale hydrocracking units at the authors site has made cheaper the non-stop running of experiments for long periods of time. It was, therefore possible to show, at minimal costs, when three hydrocracking catalysts in service reach their maximum lifetime. Different parameters which are helpful for catalyst life and activity predictions were calculated, e.g., relative catalyst age and the effectiveness factor. Experimental results compared well with model, giving them the minimum and maximum catalyst lifetime, as well as the deactivation profile with regard to sulfur and metals removal. Reaction rate constants for demetallization and desulfurization were also determined. Six commercial catalysts were evaluated at short term runs and the three most active were used for long term runs. Out of three catalysts tested for deactivation at long term runs, it was possible to choose one whose useful life was higher than the others. All runs were carried out in a Robinson-Mahoney continuous flow stirred tank reactor, using 50/50 volumetric mixture of Cold Lake/Lloydminster atmospheric residue and NiMo/Al{sub 2}O{sub 3} catalyst.

  11. [Carotenoids as natural antioxidants].

    PubMed

    Igielska-Kalwat, Joanna; Gościańska, Joanna; Nowak, Izabela

    2015-04-07

    Human organisms have many defence mechanisms able to neutralise the harmful effects of the reactive species of oxygen. Antioxidants play an important role in reducing the oxidative damage to the human organism. Carotenoids are among the strongest antioxidants. They have 11 coupled double bonds, so they can be classified as polyisoprenoids, show low polarity and can occur in acyclic, monocyclic or bicyclic forms. The carotenoids of the strongest antioxidant properties are lycopene, lutein, astaxanthin and β-carotene. Carotenoids with strong antioxidant properties have found wide application in medical, pharmaceutical and cosmetic industries. These compounds are highly active against both reactive oxygen species and free radicals. Comparing β-carotene, astaxanthin and lycopene with other antioxidants (e.g. vitamin C and E), it can be concluded that these compounds have higher antioxidant activity, e.g. against singlet oxygen. Astaxanthin is a stronger antioxidant compared to β-carotene, vitamin E and vitamin C, respectively 54, 14 and 65 times. Carotenoids have a salutary effect on our body, making it more resistant and strong to fight chronic diseases. The purpose of this article is to review the literature concerning free radicals and their adverse effects on the human body and carotenoids, as strong, natural antioxidants.

  12. Carotenoids, chemistry, sources and physiology

    USDA-ARS?s Scientific Manuscript database

    This chapter for the Enclyclopedia of Human Nutrition (3rd edition) summarizes the structure, chemical and physiological mechanisms, dietary sources, and metabolism of carotenoids. Carotenoids are a family of phytonutrients which have antioxidant properties under most physiological conditions. Num...

  13. Progress in Microbial Carotenoids Production.

    PubMed

    Saini, Ramesh Kumar; Keum, Young-Soo

    2017-03-01

    Carotenoids are versatile isoprenoids pigments, play a vital role in the cellular system, starting from antioxidant to gene regulation. Carotenoids are widely used in food, nutraceuticals, and cosmetics owing to their vitamin A, antioxidant and anticancer activities. The demand of carotenoids in various sectors has triggered the research to explore a commercially viable and environmentally friendly production. This article presents a short review of progress in carotenoids production from microbial platforms.

  14. PUREX Plant deactivation mission analysis report

    SciTech Connect

    Lund, D.P.

    1995-05-24

    The purpose of the PUREX Deactivation Project mission analysis is to define the problem to be addressed by the PUREX mission, and to lay the ground work for further system definition. The mission analysis is an important first step in the System Engineering (SE) process. This report presents the results of the PUREX Deactivation Project mission analysis. The purpose of the PUREX Deactivation Project is to prepare PUREX for Decontamination and Decommissioning within a five year time frame. This will be accomplished by establishing a passively safe and environmentally secure configuration of the PUREX Plant, that can be preserved for a 10-year horizon. During deactivation, appropriate portions of the safety envelop will be maintained to ensure deactivation takes place in a safe and regulatory compliant manner.

  15. Chemical quenching of singlet oxygen by carotenoids in plants.

    PubMed

    Ramel, Fanny; Birtic, Simona; Cuiné, Stéphan; Triantaphylidès, Christian; Ravanat, Jean-Luc; Havaux, Michel

    2012-03-01

    Carotenoids are considered to be the first line of defense of plants against singlet oxygen ((1)O(2)) toxicity because of their capacity to quench (1)O(2) as well as triplet chlorophylls through a physical mechanism involving transfer of excitation energy followed by thermal deactivation. Here, we show that leaf carotenoids are also able to quench (1)O(2) by a chemical mechanism involving their oxidation. In vitro oxidation of β-carotene, lutein, and zeaxanthin by (1)O(2) generated various aldehydes and endoperoxides. A search for those molecules in Arabidopsis (Arabidopsis thaliana) leaves revealed the presence of (1)O(2)-specific endoperoxides in low-light-grown plants, indicating chronic oxidation of carotenoids by (1)O(2). β-Carotene endoperoxide, but not xanthophyll endoperoxide, rapidly accumulated during high-light stress, and this accumulation was correlated with the extent of photosystem (PS) II photoinhibition and the expression of various (1)O(2) marker genes. The selective accumulation of β-carotene endoperoxide points at the PSII reaction centers, rather than the PSII chlorophyll antennae, as a major site of (1)O(2) accumulation in plants under high-light stress. β-Carotene endoperoxide was found to have a relatively fast turnover, decaying in the dark with a half time of about 6 h. This carotenoid metabolite provides an early index of (1)O(2) production in leaves, the occurrence of which precedes the accumulation of fatty acid oxidation products.

  16. Carotenoid fluorescence in Dunaliella salina

    PubMed Central

    van Es, Marjon A.; Janssen, Marcel; Brandenburg, Willem A.; Wijffels, René H.

    2010-01-01

    Dunaliella salina is a halotolerant green alga that is well known for its carotenoid producing capacity. The produced carotenoids are mainly stored in lipid globules. For various research purposes, such as production and extraction kinetics, we would like to determine and/or localise the carotenoid globules in vivo. In this study, we show that the carotenoid-rich globules emit clear green fluorescence, which can be used in, for example, fluorescence microscopy (e.g. CLSM) to obtain pictures of the cells and their carotenoid content. PMID:20835349

  17. List mode multichannel analyzer

    DOEpatents

    Archer, Daniel E.; Luke, S. John; Mauger, G. Joseph; Riot, Vincent J.; Knapp, David A.

    2007-08-07

    A digital list mode multichannel analyzer (MCA) built around a programmable FPGA device for onboard data analysis and on-the-fly modification of system detection/operating parameters, and capable of collecting and processing data in very small time bins (<1 millisecond) when used in histogramming mode, or in list mode as a list mode MCA.

  18. Carotenoids and cardiovascular health.

    PubMed

    Voutilainen, Sari; Nurmi, Tarja; Mursu, Jaakko; Rissanen, Tiina H

    2006-06-01

    Cardiovascular disease (CVD) is the main cause of death in Western countries. Nutrition has a significant role in the prevention of many chronic diseases such as CVD, cancers, and degenerative brain diseases. The major risk and protective factors in the diet are well recognized, but interesting new candidates continue to appear. It is well known that a greater intake of fruit and vegetables can help prevent heart diseases and mortality. Because fruit, berries, and vegetables are chemically complex foods, it is difficult to pinpoint any single nutrient that contributes the most to the cardioprotective effects. Several potential components that are found in fruit, berries, and vegetables are probably involved in the protective effects against CVD. Potential beneficial substances include antioxidant vitamins, folate, fiber, and potassium. Antioxidant compounds found in fruit and vegetables, such as vitamin C, carotenoids, and flavonoids, may influence the risk of CVD by preventing the oxidation of cholesterol in arteries. In this review, the role of main dietary carotenoids, ie, lycopene, beta-carotene, alpha-carotene, beta-cryptoxanthin, lutein, and zeaxanthin, in the prevention of heart diseases is discussed. Although it is clear that a higher intake of fruit and vegetables can help prevent the morbidity and mortality associated with heart diseases, more information is needed to ascertain the association between the intake of single nutrients, such as carotenoids, and the risk of CVD. Currently, the consumption of carotenoids in pharmaceutical forms for the treatment or prevention of heart diseases cannot be recommended.

  19. Plastids and carotenoid accumulation

    USDA-ARS?s Scientific Manuscript database

    Plastids are ubiquitously in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids except proplastids can synth...

  20. PUREX Deactivation Health and Safety documentation

    SciTech Connect

    Dodd, E.N. III

    1995-01-01

    The purpose of the PUREX Deactivation Project is to establish a passively safe and environmentally secure configuration of PUREX at the Hanford Site, and to preserve that configuration for a 10-year horizon. The 10-year horizon is used to predict future maintenance requirements and represents they typical time duration expended to define, authorize, and initiate the follow-on Decontamination and Decommissioning (D&D) activities. This document was prepared to increase attention to worker safety issues during the deactivation project and, as such, identifies the documentation and programs associated with PUREX Deactivation Health and Safety.

  1. Carotenoids and colon cancer.

    PubMed

    Slattery, M L; Benson, J; Curtin, K; Ma, K N; Schaeffer, D; Potter, J D

    2000-02-01

    Carotenoids have numerous biological properties that may underpin a role for them as chemopreventive agents. However, except for beta-carotene, little is known about how dietary carotenoids are associated with common cancers, including colon cancer. The objective of this study was to evaluate associations between dietary alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin and the risk of colon cancer. Data were collected from 1993 case subjects with first primary incident adenocarcinoma of the colon and from 2410 population-based control subjects. Dietary data were collected from a detailed diet-history questionnaire and nutrient values for dietary carotenoids were obtained from the US Department of Agriculture-Nutrition Coordinating Center carotenoid database (1998 updated version). Lutein was inversely associated with colon cancer in both men and women [odds ratio (OR) for upper quintile of intake relative to lowest quintile of intake: 0.83; 95% CI: 0.66, 1.04; P = 0.04 for linear trend]. The greatest inverse association was observed among subjects in whom colon cancer was diagnosed when they were young (OR: 0.66; 95% CI: 0.48, 0.92; P = 0.02 for linear trend) and among those with tumors located in the proximal segment of the colon (OR: 0.65; 95% CI: 0.51, 0.91; P < 0.01 for linear trend). The associations with other carotenoids were unremarkable. The major dietary sources of lutein in subjects with colon cancer and in control subjects were spinach, broccoli, lettuce, tomatoes, oranges and orange juice, carrots, celery, and greens. These data suggest that incorporating these foods into the diet may help reduce the risk of developing colon cancer.

  2. PUREX Plant deactivation function analysis report

    SciTech Connect

    Lund, D.P.; PUREX Working Group

    1995-09-01

    The document contains the functions, function definitions, function interfaces, function interface definitions, Input Computer Automated Manufacturing Definition (IDEFO) diagrams, and a function hierarchy chart that describe what needs to be performed to deactivate PUREX.

  3. Environmental Assessment for Malmstrom Minuteman III Deactivation

    DTIC Science & Technology

    2007-05-01

    deactivation process is scheduled to be completed within a 2-year time period and would occur in three phases. Phase 1 involves the removal of the missiles...of deactivation activities, the LFs and MAFs would be subject to periodic drive-by inspections to identify vandalism, unauthorized entry, topside...flooding, or excessive weed growth. The Air Force would also conduct periodic surveys for erosion, noxious weeds, and liability hazards. Site

  4. Plasma flux-dependent lipid A deactivation

    NASA Astrophysics Data System (ADS)

    Chang, Hung-Wen; Hsu, Cheng-Che; Ahmed, Musahid; Liu, Suet Yi; Fang, Yigang; Seog, Joonil; Oehrlein, Gottlieb S.; Graves, David B.

    2014-06-01

    This paper reports the influence of gas plasma flux on endotoxin lipid A film deactivation. To study the effect of the flux magnitude of reactive species, a modified low-pressure inductively coupled plasma (ICP) with O radical flux ˜1016 cm-2 s-1 was used. After ICP exposures, it was observed that while the Fourier transform infrared absorbance of fatty chains responsible for the toxicity drops by 80% through the film, no obvious film endotoxin deactivation is seen. This is in contrast to that previously observed under low flux exposure conducted in a vacuum beam system: near-surface only loss of fatty chains led to significant film deactivation. Secondary ion mass spectrometry characterization of changes at the film surface did not appear to correlate with the degree of deactivation. Lipid A films need to be nearly completely removed in order to detect significant deactivation under high flux conditions. Additional high reactive species flux experiments were conducted using an atmospheric pressure helium plasma jet and a UV/ozone device. Exposure of lipid A films to reactive species with these devices showed similar deactivation behaviour. The causes for the difference between low and high flux exposures may be due to the nature of near-surface structural modifications as a function of the rate of film removal.

  5. 42 CFR 424.540 - Deactivation of Medicare billing privileges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Deactivation of Medicare billing privileges. 424... Establishing and Maintaining Medicare Billing Privileges § 424.540 Deactivation of Medicare billing privileges. (a) Reasons for deactivation. CMS may deactivate a provider or supplier's Medicare billing...

  6. 42 CFR 424.540 - Deactivation of Medicare billing privileges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Deactivation of Medicare billing privileges. 424... Establishing and Maintaining Medicare Billing Privileges § 424.540 Deactivation of Medicare billing privileges. (a) Reasons for deactivation. CMS may deactivate a provider or supplier's Medicare billing...

  7. Multichannel Human Body Communication

    NASA Astrophysics Data System (ADS)

    Przystup, Piotr; Bujnowski, Adam; Wtorek, Jerzy

    2016-01-01

    Human Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog signal has been tested. Experiment results show that HBC is a feasible solution for transmitting data between BSN nodes.

  8. Miniature multichannel biotelemeter system

    NASA Technical Reports Server (NTRS)

    Carraway, J. B.; Sumida, J. T. (Inventor)

    1974-01-01

    A miniature multichannel biotelemeter system is described. The system includes a transmitter where signals from different sources are sampled to produce a wavetrain of pulses. The transmitter also separates signals by sync pulses. The pulses amplitude modulate a radio frequency carrier which is received at a receiver unit. There the sync pulses are detected by a demultiplexer which routes the pulses from each different source to a separate output channel where the pulses are used to reconstruct the signals from the particular source.

  9. Carotenoid-binding proteins; accessories to carotenoid function.

    PubMed

    Pilbrow, Jodi; Garama, Daniel; Carne, Alan

    2012-01-01

    Understanding of the widespread biological importance of carotenoids is increasing. Accompanying this is the developing recognition that the interaction of carotenoids with other molecules, such as proteins, is also essential. Here the significance of carotenoid-protein interactions with respect to biological function is reviewed for three well characterised carotenoprotein complexes; crustacyanin, the orange carotenoid protein and glutathione-S-transferase P1. In addition a preliminary report is made on the recent partial purification of an echinenone-binding protein extracted from a New Zealand sea urchin, Evechinus chloroticus.

  10. UO3 deactivation end point criteria

    SciTech Connect

    Stefanski, L.D.

    1994-10-01

    The UO{sub 3} Deactivation End Point Criteria are necessary to facilitate the transfer of the UO{sub 3} Facility from the Office of Facility Transition and Management (EM-60) to the office of Environmental Restoration (EM-40). The criteria were derived from a logical process for determining end points for the systems and spaces at the UO{sub 3}, Facility based on the objectives, tasks, and expected future uses pertinent to that system or space. Furthermore, the established criteria meets the intent and supports the draft guidance for acceptance criteria prepared by EM-40, {open_quotes}U.S. Department of Energy office of Environmental Restoration (EM-40) Decontamination and Decommissioning Guidance Document (Draft).{close_quotes} For the UO{sub 3} Facility, the overall objective of deactivation is to achieve a safe, stable and environmentally sound condition, suitable for an extended period, as quickly and economically as possible. Once deactivated, the facility is kept in its stable condition by means of a methodical surveillance and maintenance (S&M) program, pending ultimate decontamination and decommissioning (D&D). Deactivation work involves a range of tasks, such as removal of hazardous material, elimination or shielding of radiation fields, partial decontamination to permit access for inspection, installation of monitors and alarms, etc. it is important that the end point of each of these tasks be established clearly and in advance, for the following reasons: (1) End points must be such that the central element of the deactivation objective - to achieve stability - is unquestionably achieved. (2) Much of the deactivation work involves worker exposure to radiation or dangerous materials. This can be minimized by avoiding unnecessary work. (3) Each task is, in effect, competing for resources with other deactivation tasks and other facilities. By assuring that each task is appropriately bounded, DOE`s overall resources can be used most fully and effectively.

  11. Collisional deactivation of highly vibrationally excited pyrazine

    NASA Astrophysics Data System (ADS)

    Miller, Laurie A.; Barker, John R.

    1996-07-01

    The collisional deactivation of vibrationally excited pyrazine (C4N2H4) in the electronic ground state by 19 collider gases was studied using the time-resolved infrared fluorescence (IRF) technique. The pyrazine was photoexcited with a 308 nm laser and its vibrational deactivation was monitored following rapid radiationless transitions to produce vibrationally excited molecules in the electronic ground state. The IRF data were analyzed by a simple approximate inversion method, as well as with full collisional master equation simulations. The average energies transferred in deactivating collisions (<ΔE>d) exhibit a near-linear dependence on vibrational energy at lower energies and less dependence at higher energies. The deactivation of ground state pyrazine was found to be similar to that of ground state benzene [J. R. Barker and B. M. Toselli, Int. Rev. Phys. Chem. 12, 305 (1990)], but it is strikingly different from the deactivation of triplet state pyrazine [T. J. Bevilacqua and R. B. Weisman, J. Chem. Phys. 98, 6316 (1993)].

  12. Multichannel interval timer (MINT)

    SciTech Connect

    Kimball, K.B.

    1982-06-01

    A prototype Multichannel INterval Timer (MINT) has been built for measuring signal Time of Arrival (TOA) from sensors placed in blast environments. The MINT is intended to reduce the space, equipment costs, and data reduction efforts associated with traditional analog TOA recording methods, making it more practical to field the large arrays of TOA sensors required to characterize blast environments. This document describes the MINT design features, provides the information required for installing and operating the system, and presents proposed improvements for the next generation system.

  13. Fractional channel multichannel analyzer

    DOEpatents

    Brackenbush, Larry W.; Anderson, Gordon A.

    1994-01-01

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynscronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board.

  14. Fractional channel multichannel analyzer

    DOEpatents

    Brackenbush, L.W.; Anderson, G.A.

    1994-08-23

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynchronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board. 9 figs.

  15. Biological activities of carotenoid metabolites

    USDA-ARS?s Scientific Manuscript database

    Considerable research effort has been expended in an attempt to substantiate and understand the potential roles of carotenoids in human health and disease. Early studies dealt with beta-carotene and other provitamin A carotenoids, but more recent research efforts have focused on the potential roles ...

  16. Carotenoids and lung cancer prevention

    USDA-ARS?s Scientific Manuscript database

    Understanding the molecular actions of carotenoids is critical for human studies involving carotenoids for prevention of lung cancer and cancers at other tissue sites. While the original hypothesis prompting the beta-carotene intervention trials was that beta-carotene exerts beneficial effects thro...

  17. N Reactor Deactivation Program Plan. Revision 4

    SciTech Connect

    Walsh, J.L.

    1993-12-01

    This N Reactor Deactivation Program Plan is structured to provide the basic methodology required to place N Reactor and supporting facilities {center_dot} in a radiologically and environmentally safe condition such that they can be decommissioned at a later date. Deactivation will be in accordance with facility transfer criteria specified in Department of Energy (DOE) and Westinghouse Hanford Company (WHC) guidance. Transition activities primarily involve shutdown and isolation of operational systems and buildings, radiological/hazardous waste cleanup, N Fuel Basin stabilization and environmental stabilization of the facilities. The N Reactor Deactivation Program covers the period FY 1992 through FY 1997. The directive to cease N Reactor preservation and prepare for decommissioning was issued by DOE to WHC on September 20, 1991. The work year and budget data supporting the Work Breakdown Structure in this document are found in the Activity Data Sheets (ADS) and the Environmental Restoration Program Baseline, that are prepared annually.

  18. On the CCN (de)activation nonlinearities

    NASA Astrophysics Data System (ADS)

    Arabas, Sylwester; Shima, Shin-ichiro

    2017-09-01

    We take into consideration the evolution of particle size in a monodisperse aerosol population during activation and deactivation of cloud condensation nuclei (CCN). Our analysis reveals that the system undergoes a saddle-node bifurcation and a cusp catastrophe. The control parameters chosen for the analysis are the relative humidity and the particle concentration. An analytical estimate of the activation timescale is derived through estimation of the time spent in the saddle-node bifurcation bottleneck. Numerical integration of the system coupled with a simple air-parcel cloud model portrays two types of activation/deactivation hystereses: one associated with the kinetic limitations on droplet growth when the system is far from equilibrium, and one occurring close to equilibrium and associated with the cusp catastrophe. We discuss the presented analyses in context of the development of particle-based models of aerosol-cloud interactions in which activation and deactivation impose stringent time-resolution constraints on numerical integration.

  19. Metal-deactivating additives for liquid fuels

    SciTech Connect

    Boneva, M.I.; Ivanov, S.K.; Kalitchin, Z.D.; Tanielyan, S.K.; Terebenina, A.; Todorova, O.I.

    1995-05-01

    The metal-deactivating and the antioxidant properties of 1-phenyl-3-methylpyrazolone-5 derivatives have been investigated both in the model reaction of low temperature oxidation of ethylbenzene and in gasoline oxidation. The study of the ability of these derivatives to reduce the catalytic effect of copper naphthenate demonstrates that they are promising as metal deactivating additives for light fuels. Some of the pyrazolone compounds appear to be of special interest for the long-term storage of liquid fuels due to their action as multifunctional inhibitors.

  20. Deactivation completed at historic Hanford Fuels Laboratory

    SciTech Connect

    Gerber, M.S.

    1994-03-01

    This report discusses deactivation work which was completed as of March 31, 1994 at the 308 Fuels Development Laboratory (FDL) at the Hanford Site near Richland, Washington. The decision to deactivate the structure, formerly known as the Plutonium Fabrication Pilot Plant (PFPP), was driven by a 1980s Department of Energy (DOE) decision that plutonium fuels should not be fabricated in areas near the Site`s boundaries, as well as by changing facility structural requirements. Inventory transfer has been followed by the cleanout and stabilization of plutonium oxide (PuO{sub 2}) and enriched uranium oxide (UO{sub 2}) residues and powders in the facility`s equipment and duct work. The Hanford Site, located in southeastern Washington state, was one of America`s primary arsenals of nuclear defense production for nearly 50 years beginning in World War II. Approximately 53 metric tons of weapons grade plutonium, over half of the national supply and about one quarter of the world`s supply, were produced at Hanford between 1944 and 1989. Today, many Site buildings are undergoing deactivation, a precursor phase to decontamination and decommissioning (D&D). The primary difference between the two activities is that equipment and structural items are not removed or torn down in deactivation. However, utilities are disconnected, and special nuclear materials (SNM) as well as hazardous and pyrophoric substances are removed from structures undergoing this process.

  1. The Approach of Emotional Deactivation of Prejudice

    ERIC Educational Resources Information Center

    Boucher, Jean-Nil

    2011-01-01

    The aim of the approach of emotional deactivation is to help students reduce the prejudice they may feel towards diverse social groups. Be those groups homosexuals, people living with a disability or immigrants, the victims of prejudice are invited to come into classrooms and to confront the preconceptions that students have in their respect.…

  2. 340 Waste handling facility deactivation plan

    SciTech Connect

    Stordeur, R.T., Westinghouse Hanford

    1996-12-27

    This document provides an overview of both the present status of the 340 Complex (within Hanford`s 300 Area), and of tasks associated with the deactivation of segments associated with radioactive, mixed liquid waste receipt, storage, and shipping. The plan also describes activities that will allow portions of the 340 Complex to remain in service.

  3. Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

    PubMed Central

    Banghart, Matthew R.; Shah, Ruchir C.; Lavis, Luke D.

    2013-01-01

    The spatiotemporal dynamics of opioid signaling in the brain remain poorly defined. Photoactivatable opioid ligands provide a means to quantitatively measure these dynamics and their underlying mechanisms in brain tissue. Although activation kinetics can be assessed using caged agonists, deactivation kinetics are obscured by slow clearance of agonist in tissue. To reveal deactivation kinetics of opioid signaling we developed a caged competitive antagonist that can be quickly photoreleased in sufficient concentrations to render agonist dissociation effectively irreversible. Carboxynitroveratryl-naloxone (CNV-NLX), a caged analog of the competitive opioid antagonist NLX, was readily synthesized from commercially available NLX in good yield and found to be devoid of antagonist activity at heterologously expressed opioid receptors. Photolysis in slices of rat locus coeruleus produced a rapid inhibition of the ionic currents evoked by multiple agonists of the μ-opioid receptor (MOR), but not of α-adrenergic receptors, which activate the same pool of ion channels. Using the high-affinity peptide agonist dermorphin, we established conditions under which light-driven deactivation rates are independent of agonist concentration and thus intrinsic to the agonist-receptor complex. Under these conditions, some MOR agonists yielded deactivation rates that are limited by G protein signaling, whereas others appeared limited by agonist dissociation. Therefore, the choice of agonist determines which feature of receptor signaling is unmasked by CNV-NLX photolysis. PMID:23960100

  4. The Approach of Emotional Deactivation of Prejudice

    ERIC Educational Resources Information Center

    Boucher, Jean-Nil

    2011-01-01

    The aim of the approach of emotional deactivation is to help students reduce the prejudice they may feel towards diverse social groups. Be those groups homosexuals, people living with a disability or immigrants, the victims of prejudice are invited to come into classrooms and to confront the preconceptions that students have in their respect.…

  5. 309 Building deactivation mission analysis report

    SciTech Connect

    Lund, D.P.

    1995-05-24

    This report presents the results of the 309 Building (Plutonium Fuels Utilization Program) Deactivation Project mission analysis. Hanford systems engineering (SE) procedures call for a mission analysis. The mission analysis is an important first step in the SE process. The functions and requirements to successfully accomplish this mission, the selected alternatives and products will later be defined using the SE process.

  6. Biological roles of fungal carotenoids.

    PubMed

    Avalos, Javier; Carmen Limón, M

    2015-08-01

    Carotenoids are terpenoid pigments widespread in nature, produced by bacteria, fungi, algae and plants. They are also found in animals, which usually obtain them through the diet. Carotenoids in plants provide striking yellow, orange or red colors to fruits and flowers, and play important metabolic and physiological functions, especially relevant in photosynthesis. Their functions are less clear in non-photosynthetic microorganisms. Different fungi produce diverse carotenoids, but the mutants unable to produce them do not exhibit phenotypic alterations in the laboratory, apart of lack of pigmentation. This review summarizes the current knowledge on the functional basis for carotenoid production in fungi. Different lines of evidence support a protective role of carotenoids against oxidative stress and exposure to visible light or UV irradiation. In addition, the carotenoids are intermediary products in the biosynthesis of physiologically active apocarotenoids or derived compounds. This is the case of retinal, obtained from the symmetrical oxidative cleavage of β-carotene. Retinal is the light-absorbing prosthetic group of the rhodopsins, membrane-bound photoreceptors present also in many fungal species. In Mucorales, β-carotene is an intermediary in the synthesis of trisporoids, apocarotenoid derivatives that include the sexual hormones the trisporic acids, and they are also presumably used in the synthesis of sporopollenin polymers. In conclusion, fungi have adapted their ability to produce carotenoids for different non-essential functions, related with stress tolerance or with the synthesis of physiologically active by-products.

  7. Carotenoid Biosynthesis in Daucus carota.

    PubMed

    Simpson, Kevin; Cerda, Ariel; Stange, Claudia

    2016-01-01

    Carrot (Daucus carota) is one of the most important vegetable cultivated worldwide and the main source of dietary provitamin A. Contrary to other plants, almost all carrot varieties accumulate massive amounts of carotenoids in the root, resulting in a wide variety of colors, including those with purple, yellow, white, red and orange roots. During the first weeks of development the root, grown in darkness, is thin and pale and devoid of carotenoids. At the second month, the thickening of the root and the accumulation of carotenoids begins, and it reaches its highest level at 3 months of development. This normal root thickening and carotenoid accumulation can be completely altered when roots are grown in light, in which chromoplasts differentiation is redirected to chloroplasts development in accordance with an altered carotenoid profile. Here we discuss the current evidence on the biosynthesis of carotenoid in carrot roots in response to environmental cues that has contributed to our understanding of the mechanism that regulates the accumulation of carotenoids, as well as the carotenogenic gene expression and root development in D. carota.

  8. Food predictors of plasma carotenoids.

    PubMed

    Hendrickson, Sara J; Willett, Walter C; Rosner, Bernard A; Eliassen, A Heather

    2013-10-11

    Empirical prediction models that weight food frequency questionnaire (FFQ) food items by their relation to nutrient biomarker concentrations may estimate nutrient exposure better than nutrient intakes derived from food composition databases. Carotenoids may especially benefit because contributing foods vary in bioavailability and assessment validity. Our objective was to develop empirical prediction models for the major plasma carotenoids and total carotenoids and evaluate their validity compared with dietary intakes calculated from standard food composition tables. 4180 nonsmoking women in the Nurses' Health Study (NHS) blood subcohort with previously measured plasma carotenoids were randomly divided into training (n = 2787) and testing (n = 1393) subsets. Empirical prediction models were developed in the training subset by stepwise selection from foods contributing ≥0.5% to intake of the relevant carotenoid. Spearman correlations between predicted and measured plasma concentrations were compared to Spearman correlations between dietary intake and measured plasma concentrations for each carotenoid. Three to 12 foods were selected for the α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene, and total carotenoids prediction models. In the testing subset, Spearman correlations with measured plasma concentrations for the calculated dietary intakes and predicted plasma concentrations, respectively, were 0.31 and 0.37 for α-carotene, 0.29 and 0.31 for β-carotene, 0.36 and 0.41 for β-cryptoxanthin, 0.28 and 0.31 for lutein/zeaxanthin, 0.22 and 0.23 for lycopene, and 0.22 and 0.27 for total carotenoids. Empirical prediction models may modestly improve assessment of some carotenoids, particularly α-carotene and β-cryptoxanthin.

  9. Food Predictors of Plasma Carotenoids

    PubMed Central

    Hendrickson, Sara J.; Willett, Walter C.; Rosner, Bernard A.; Eliassen, A. Heather

    2013-01-01

    Empirical prediction models that weight food frequency questionnaire (FFQ) food items by their relation to nutrient biomarker concentrations may estimate nutrient exposure better than nutrient intakes derived from food composition databases. Carotenoids may especially benefit because contributing foods vary in bioavailability and assessment validity. Our objective was to develop empirical prediction models for the major plasma carotenoids and total carotenoids and evaluate their validity compared with dietary intakes calculated from standard food composition tables. 4180 nonsmoking women in the Nurses’ Health Study (NHS) blood subcohort with previously measured plasma carotenoids were randomly divided into training (n = 2787) and testing (n = 1393) subsets. Empirical prediction models were developed in the training subset by stepwise selection from foods contributing ≥0.5% to intake of the relevant carotenoid. Spearman correlations between predicted and measured plasma concentrations were compared to Spearman correlations between dietary intake and measured plasma concentrations for each carotenoid. Three to 12 foods were selected for the α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene, and total carotenoids prediction models. In the testing subset, Spearman correlations with measured plasma concentrations for the calculated dietary intakes and predicted plasma concentrations, respectively, were 0.31 and 0.37 for α-carotene, 0.29 and 0.31 for β-carotene, 0.36 and 0.41 for β-cryptoxanthin, 0.28 and 0.31 for lutein/zeaxanthin, 0.22 and 0.23 for lycopene, and 0.22 and 0.27 for total carotenoids. Empirical prediction models may modestly improve assessment of some carotenoids, particularly α-carotene and β-cryptoxanthin. PMID:24152746

  10. Software Configurable Multichannel Transceiver

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.; Cornelius, Harold; Hickling, Ron; Brooks, Walter

    2009-01-01

    Emerging test instrumentation and test scenarios increasingly require network communication to manage complexity. Adapting wireless communication infrastructure to accommodate challenging testing needs can benefit from reconfigurable radio technology. A fundamental requirement for a software-definable radio system is independence from carrier frequencies, one of the radio components that to date has seen only limited progress toward programmability. This paper overviews an ongoing project to validate the viability of a promising chipset that performs conversion of radio frequency (RF) signals directly into digital data for the wireless receiver and, for the transmitter, converts digital data into RF signals. The Software Configurable Multichannel Transceiver (SCMT) enables four transmitters and four receivers in a single unit the size of a commodity disk drive, programmable for any frequency band between 1 MHz and 6 GHz.

  11. Multichannel optical sensing device

    DOEpatents

    Selkowitz, S.E.

    1985-08-16

    A multichannel optical sensing device is disclosed, for measuring the outdoor sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optical elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  12. Multichannel optical sensing device

    DOEpatents

    Selkowitz, Stephen E.

    1990-01-01

    A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  13. Signal Functions of Carotenoid Colouration

    NASA Astrophysics Data System (ADS)

    Blount, Jonathan D.; McGraw, Kevin J.

    The importance of carotenoids for natural colouration, in relation to other classes of pigments and structural colours, has been outlined in Chapter 10. But colour only has significance if it is perceived, identified and interpreted by other organisms (animals). In other words, colour is a means of communication, a signal. Now, in this Chapter, this new direction for carotenoid research, behavioural ecology, is highlighted. Various hypotheses that have been proposed to explain the signal functions of colour, and particularly of carotenoids, in plants and animals are discussed and the empirical evidence to support these hypotheses is presented.

  14. Multichannel electrochemical microbial detection unit

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Young, R. N.; Boykin, E. H.

    1978-01-01

    The paper describes the design and capabilities of a compact multichannel electrochemical unit devised to detect and automatically indicate detection time length of bacteria. By connecting this unit to a strip-chart recorder, a permanent record is obtained of the end points and growth curves for each of eight channels. The experimental setup utilizing the multichannel unit consists of a test tube (25 by 150 mm) containing a combination redox electrode plus 18 ml of lauryl tryptose broth and positioned in a 35-C water bath. Leads from the electrodes are connected to the multichannel unit, which in turn is connected to a strip-chart recorder. After addition of 2.0 ml of inoculum to the test tubes, depression of the push-button starter activates the electronics, timer, and indicator light for each channel. The multichannel unit is employed to test tenfold dilutions of various members of the Enterobacteriaceae group, and a typical dose-response curve is presented.

  15. Digital restoration of multichannel images

    NASA Technical Reports Server (NTRS)

    Galatsanos, Nikolas P.; Chin, Roland T.

    1989-01-01

    The Wiener solution of a multichannel restoration scheme is presented. Using matrix diagonalization and block-Toeplitz to block-circulant approximation, the inversion of the multichannel, linear space-invariant imaging system becomes feasible by utilizing a fast iterative matrix inversion procedure. The restoration uses both the within-channel (spatial) and between-channel (spectral) correlation; hence, the restored result is a better estimate than that produced by independent channel restoration. Simulations are also presented.

  16. Chemistry and biotechnology of carotenoids.

    PubMed

    Namitha, K K; Negi, P S

    2010-09-01

    Carotenoids are one of the most widespread groups of pigments in nature and more than 600 of these have been identified. Beside provitamin A activity, carotenoids are important as antioxidants and protective agents against various diseases. They are isoprenoids with a long polyene chain containing 3 to 15 conjugated double bonds, which determines their absorption spectrum. Cyclization at one or both ends occurs in hydrocarbon carotene, while xanthophylls are formed by the introduction of oxygen. In addition, modifications involving chain elongation, isomerization, or degradation are also found. The composition of carotenoids in food may vary depending upon production practices, post-harvest handling, processing, and storage. In higher plants they are synthesized in the plastid. Both mevalonate dependent and independent pathway for the formation of isopentenyl diphosphate are known. Isopentenyl diphosphate undergoes a series of addition and condensation reactions to form phytoene, which gets converted to lycopene. Cyclization of lycopene either leads to the formation of β-carotene and its derivative xanthophylls, β-cryptoxanthin, zeaxanthin, antheraxanthin, and violaxanthin or α-carotene and lutein. Even though most of the carotenoid biosynthetic genes have been cloned and identified, some aspects of carotenoid formation and manipulation in higher plants especially remain poorly understood. In order to enhance the carotenoid content of crop plants to a level that will be required for the prevention of diseases, there is a need for research in both the basic and the applied aspects.

  17. Marine Carotenoids: Biological Functions and Commercial Applications

    PubMed Central

    Vílchez, Carlos; Forján, Eduardo; Cuaresma, María; Bédmar, Francisco; Garbayo, Inés; Vega, José M.

    2011-01-01

    Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon. PMID:21556162

  18. Marine carotenoids: biological functions and commercial applications.

    PubMed

    Vílchez, Carlos; Forján, Eduardo; Cuaresma, María; Bédmar, Francisco; Garbayo, Inés; Vega, José M

    2011-03-03

    Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon.

  19. Temperature (de)activated patchy colloidal particles.

    PubMed

    de Las Heras, Daniel; da Gama, Margarida M Telo

    2016-06-22

    We present a new model of patchy particles in which the interaction sites can be activated or deactivated by varying the temperature of the system. We study the thermodynamics of the system by means of Wertheim's first order perturbation theory, and use Flory-Stockmayer theory of polymerization to analyse the percolation threshold. We find a very rich phase behaviour including lower critical points and reentrant percolation.

  20. Deactivation and poisoning of fuel cell catalysts

    NASA Astrophysics Data System (ADS)

    Ross, P. N., Jr.

    1985-06-01

    The deactivation and poisoning phenomena reviewed are: the poisoning of anode (fuel electrode) catalyst by carbon monoxide and hydrogen sulfide; the deactivation of the cathode (air electrode) catalyst by sintering; and the deactivation of the cathode by corrosion of the support. The anode catalyst is Pt supported on a conductive, high area carbon black, usually at a loading of 10 w/o. This catalyst is tolerant to some level of carbon monoxide or hydrogen sulfide or both in combination, the level depending on temperature and pressure. Much less is known about hydrogen sulfide poisoning. Typical tolerance levels are 2% CO, and 10 ppM H2S. The cathode catalyst is typically Pt supported on a raphitic carbon black, usually a furnace black heat-treated to 2700 C. The Pt loading is typically 10 w/o, and the dispersion (or percent exposed) as-prepared is typically 30%. The loss of dispersion in use depends on the operational parameters, most especially the cathode potential history, i.e., higher potentials cause more rapid decrease in dispersion. The mechanism of loss of dispersion is not well known. The graphitic carbon support corrodes at a finite rate that is also potential dependent. Support corrosion causes thickening of the electrolyte film between the gas pores and the catalyst particles, which in turn causes increased diffusional resistance and performance loss.

  1. Photophysical deactivation pathways in adenine oligonucleotides.

    PubMed

    Spata, Vincent A; Matsika, Spiridoula

    2015-12-14

    In this work we study deactivation processes in adenine oligomers after absorption of UV radiation using Quantum Mechanics combined with Molecular Mechanics (QM/MM). Correlated electronic structure methods appropriate for describing the excited states are used to describe a π-stacked dimer of adenine bases incorporated into (dA)20(dT)20. The results of these calculations reveal three different types of excited state minima which play a role in deactivation processes. Within this set of minima there are minima where the excited state is localized on one adenine (monomer-like) as well as minima where the excited state is delocalized on two adenines, forming different types of excimers and bonded excimers of varying but inter-related character. The proximity of their energies reveals that the minima can decay into one another along a flat potential energy surface dependent on the interbase separation. Additionally, analysis of the emissive energies and other physical properties, including theoretical anisotropy calculations, and comparison with fluorescence experiments, provides evidence that excimers play an important role in long-lived signals in adenine oligonucleotides while the subpicosecond decay is attributed to monomer-like minima. The necessity for a close approach of the nucleobases reveals that the deactivation mechanism is tied to macro-molecular motion.

  2. Multichannel demultiplexer-demodulator

    NASA Astrophysics Data System (ADS)

    Courtois, Hector; Sherry, Mike; Cangiane, Peter; Caso, Greg

    1993-11-01

    One of the critical satellite technologies in a meshed VSAT (very small aperture terminal) satellite communication networks utilizing FDMA (frequency division multiple access) uplinks is a multichannel demultiplexer/demodulator (MCDD). TRW Electronic Systems Group developed a proof-of-concept (POC) MCDD using advanced digital technologies. This POC model demonstrates the capability of demultiplexing and demodulating multiple low to medium data rate FDMA uplinks with potential for expansion to demultiplexing and demodulating hundreds to thousands of narrowband uplinks. The TRW approach uses baseband sampling followed by successive wideband and narrowband channelizers with each channelizer feeding into a multirate, time-shared demodulator. A full-scale MCDD would consist of an 8 bit A/D sampling at 92.16 MHz, four wideband channelizers capable of demultiplexing eight wideband channels, thirty-two narrowband channelizers capable of demultiplexing one wideband signal into 32 narrowband channels, and thirty-two multirate demodulators. The POC model consists of an 8 bit A/D sampling at 23.04 MHz, one wideband channelizer, 16 narrowband channelizers, and three multirate demodulators. The implementation loss of the wideband and narrowband channels is 0.3dB and 0.75dB at 10(exp -7) E(sub b)/N(sub o) respectively.

  3. Multichannel demultiplexer-demodulator

    NASA Technical Reports Server (NTRS)

    Courtois, Hector; Sherry, Mike; Cangiane, Peter; Caso, Greg

    1993-01-01

    One of the critical satellite technologies in a meshed VSAT (very small aperture terminal) satellite communication networks utilizing FDMA (frequency division multiple access) uplinks is a multichannel demultiplexer/demodulator (MCDD). TRW Electronic Systems Group developed a proof-of-concept (POC) MCDD using advanced digital technologies. This POC model demonstrates the capability of demultiplexing and demodulating multiple low to medium data rate FDMA uplinks with potential for expansion to demultiplexing and demodulating hundreds to thousands of narrowband uplinks. The TRW approach uses baseband sampling followed by successive wideband and narrowband channelizers with each channelizer feeding into a multirate, time-shared demodulator. A full-scale MCDD would consist of an 8 bit A/D sampling at 92.16 MHz, four wideband channelizers capable of demultiplexing eight wideband channels, thirty-two narrowband channelizers capable of demultiplexing one wideband signal into 32 narrowband channels, and thirty-two multirate demodulators. The POC model consists of an 8 bit A/D sampling at 23.04 MHz, one wideband channelizer, 16 narrowband channelizers, and three multirate demodulators. The implementation loss of the wideband and narrowband channels is 0.3dB and 0.75dB at 10(exp -7) E(sub b)/N(sub o) respectively.

  4. Enhancement of carotenoid-to-chlorophyll singlet energy transfer by carotenoid-carotenoid interaction.

    PubMed Central

    Zurdo, J; Fernández-Cabrera, C; Ramírez, J M

    1992-01-01

    The apparent quantum yield of singlet-singlet spirilloxanthin-to-bacteriochlorophyll a energy transfer increases linearly with the residual spirilloxanthin content in Rhodospirillum rubrum membrane vesicles from which this carotenoid has been partially removed. Since it has been previously shown that carotenoid-carotenoid interaction is a linear function of the residual spirilloxanthin level in the major pigment-protein complex of those vesicles (Zurdo, J., R. M. Lozano, C. Fernandez-Cabrera, and J. M. Ramirez. 1991. Biochem. J. 274:881-884), it appears that such degenerate interaction enhances singlet energy transfer. Part of the enhancement may be explained if the energy donor is the spirilloxanthin 1Bu----1Ag (S2----S0) transition, because exciton coupling probably brings its energy closer to that of the Qx (S2----S0) transition of bacteriochlorophyll. In contrast, it seems that the possible stabilization of the spirilloxanthin 2Ag (S1) state would hardly improve energy transfer, because this hidden state probably lies below the S1 bacteriochlorophyll state. In any case, the stabilizing effects of carotenoid-carotenoid interactions seem insufficient to explain the enhancement of energy transfer. Direct or indirect effects of carotenoid dimerization on the three-dimensional structure of the pigment cluster appear to be required to account for such enhancement. PMID:1617133

  5. Enhancement of carotenoid-to-chlorophyll singlet energy transfer by carotenoid-carotenoid interaction.

    PubMed

    Zurdo, J; Fernández-Cabrera, C; Ramírez, J M

    1992-06-01

    The apparent quantum yield of singlet-singlet spirilloxanthin-to-bacteriochlorophyll a energy transfer increases linearly with the residual spirilloxanthin content in Rhodospirillum rubrum membrane vesicles from which this carotenoid has been partially removed. Since it has been previously shown that carotenoid-carotenoid interaction is a linear function of the residual spirilloxanthin level in the major pigment-protein complex of those vesicles (Zurdo, J., R. M. Lozano, C. Fernandez-Cabrera, and J. M. Ramirez. 1991. Biochem. J. 274:881-884), it appears that such degenerate interaction enhances singlet energy transfer. Part of the enhancement may be explained if the energy donor is the spirilloxanthin 1Bu----1Ag (S2----S0) transition, because exciton coupling probably brings its energy closer to that of the Qx (S2----S0) transition of bacteriochlorophyll. In contrast, it seems that the possible stabilization of the spirilloxanthin 2Ag (S1) state would hardly improve energy transfer, because this hidden state probably lies below the S1 bacteriochlorophyll state. In any case, the stabilizing effects of carotenoid-carotenoid interactions seem insufficient to explain the enhancement of energy transfer. Direct or indirect effects of carotenoid dimerization on the three-dimensional structure of the pigment cluster appear to be required to account for such enhancement.

  6. Fluorescence of carotenoids. Effect of oxygenation and cis/trans isomerization

    NASA Astrophysics Data System (ADS)

    Jørgensen, Kevin; Stapelfeldt, Henrik; Skibsted, Leif H.

    1992-03-01

    C 40 carotenoids fall, with respect to fluorescence in homogeneous solution, into two distinct groups depending on the presence of a CO group in the molecule. Excitation spectra agree with absorption spectra for the carbonyl derivatives astaxanthin and canthaxanthin. In contrast, zeaxanthin and isomers of β-carotene have a twentyfold increase in fluorescence quantum yield for excitation around 350 nm compared to excitation near the absorption maximum (at approximatively 430 nm). These differences are interpreted in terms of the role of non-emitting 1(n, π*) states related to the CO group in facilitating non-radiative deactivation of higher 1(π, π*) states.

  7. Carotenoids' production from halophilic bacteria.

    PubMed

    de Lourdes Moreno, María; Sánchez-Porro, Cristina; García, María Teresa; Mellado, Encarnación

    2012-01-01

    Carotenoids have received considerable attention due to their interesting industrial applications and, more importantly, their potential beneficial effects on human health. Halophiles comprise a heterogeneous group of microorganisms that need salts for optimal growth. The pigments produced by these halophilic organisms comprise phytoene, β-carotene, lycopene, derivatives of bacterioruberin, and salinixanthin. Here, we describe the procedure to obtain salinixanthin from the extremely halophilic bacterium Salinibacter ruber. Additionally, we describe the expression of the β-carotene biosynthetic genes crtE, crtY, crtI, and crtB from Pantoea agglomerans in the moderately halophilic bacterium Halomonas elongata obtaining a strain able to produce practically pure β-carotene. Thus, the use of these halophilic microorganisms as a source of carotenoids constitutes an important commercial alternative in the production of carotenoids from biological sources.

  8. Note: An underwater multi-channel plasma array for water sterilization

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Kim, H.; Starikovskiy, A.; Cho, Y. I.; Fridman, A.

    2011-09-01

    A simple yet effective method to generate multi-channel plasma array in water is presented in this paper. Thin circular metal disks sandwiched between dielectric layers were used, allowing the production of large-volume underwater plasma array with higher stability. The system can be further scaled up by stacking multiple metal disks, making it suitable for large-scale industrial water treatment. Generation of UV and reactive species was identified by optical emission spectroscopy. Sterilization experiments were performed. Results show that the device was effective in deactivating E. coli in water over a wide range of initial concentrations ranging from 104 to 108 CFU/ml.

  9. Chemical Quenching of Singlet Oxygen by Carotenoids in Plants1[C][W

    PubMed Central

    Ramel, Fanny; Birtic, Simona; Cuiné, Stéphan; Triantaphylidès, Christian; Ravanat, Jean-Luc; Havaux, Michel

    2012-01-01

    Carotenoids are considered to be the first line of defense of plants against singlet oxygen (1O2) toxicity because of their capacity to quench 1O2 as well as triplet chlorophylls through a physical mechanism involving transfer of excitation energy followed by thermal deactivation. Here, we show that leaf carotenoids are also able to quench 1O2 by a chemical mechanism involving their oxidation. In vitro oxidation of β-carotene, lutein, and zeaxanthin by 1O2 generated various aldehydes and endoperoxides. A search for those molecules in Arabidopsis (Arabidopsis thaliana) leaves revealed the presence of 1O2-specific endoperoxides in low-light-grown plants, indicating chronic oxidation of carotenoids by 1O2. β-Carotene endoperoxide, but not xanthophyll endoperoxide, rapidly accumulated during high-light stress, and this accumulation was correlated with the extent of photosystem (PS) II photoinhibition and the expression of various 1O2 marker genes. The selective accumulation of β-carotene endoperoxide points at the PSII reaction centers, rather than the PSII chlorophyll antennae, as a major site of 1O2 accumulation in plants under high-light stress. β-Carotene endoperoxide was found to have a relatively fast turnover, decaying in the dark with a half time of about 6 h. This carotenoid metabolite provides an early index of 1O2 production in leaves, the occurrence of which precedes the accumulation of fatty acid oxidation products. PMID:22234998

  10. Modular multichannel surface plasmon spectrometer

    NASA Astrophysics Data System (ADS)

    Neuert, G.; Kufer, S.; Benoit, M.; Gaub, H. E.

    2005-05-01

    We have developed a modular multichannel surface plasmon resonance (SPR) spectrometer on the basis of a commercially available hybrid sensor chip. Due to its modularity this inexpensive and easy to use setup can readily be adapted to different experimental environments. High temperature stability is achieved through efficient thermal coupling of individual SPR units. With standard systems the performance of the multichannel instrument was evaluated. The absorption kinetics of a cysteamine monolayer, as well as the concentration dependence of the specific receptor-ligand interaction between biotin and streptavidin was measured.

  11. Carotenoid-dependent signals and the evolution of plasma carotenoid levels in birds.

    PubMed

    Simons, Mirre J P; Maia, Rafael; Leenknegt, Bas; Verhulst, Simon

    2014-12-01

    Sexual selection has resulted in a wide array of ornaments used in mate choice, and such indicator traits signal quality honestly when they bear costs, precluding cheating. Carotenoid-dependent coloration has attracted considerable attention in this context, because investing carotenoids in coloration has to be traded off against its physiological functions; carotenoids are antioxidants and increase immunocompetence. This trade-off is hypothesized to underlie the honesty of carotenoid-dependent coloration, signaling the "handicap" of allocating carotenoids away from somatic maintenance toward sexual display. Utilizing recent advances in modeling adaptive evolution, we used a comparative approach to investigate the evolution of plasma carotenoid levels using a species-level phylogeny of 178 bird species. We find that the evolutionary optimum for carotenoid levels is higher in lineages that evolved carotenoid-dependent coloration, with strong attraction toward this optimum. Hence, carotenoids do not appear to be limiting, given that higher carotenoid levels readily evolve in response to the evolution of carotenoid-dependent coloration. These findings challenge the assumption that carotenoids are a scarce resource and thus also challenge the hypothesis that physiological resource value of carotenoids underlies honesty of carotenoid-dependent traits. Therefore, the comparative evidence suggests that other factors, such as the acquisition and incorporation of carotenoids, are involved in maintaining signal honesty.

  12. Antioxidant Deactivation on Graphenic Nanocarbon Surfaces

    SciTech Connect

    Liu, Xinyuan; Sen, Sujat; Liu, Jingyu; Kulaots, Indrek; Geohegan, David B; Kane, Agnes; Puretzky, Alexander A; Rouleau, Christopher M; More, Karren Leslie; Palmore, G. Tayhas R.; Hurt, Robert H.

    2011-01-01

    This article reports a direct chemical pathway for antioxidant deactivation on the surfaces of carbon nanomaterials. In the absence of cells, carbon nanotubes are shown to deplete the key physiological antioxidant glutathione (GSH) in a reaction involving dissolved dioxygen that yields the oxidized dimer, GSSG, as the primary product. In both chemical and electrochemical experiments, oxygen is only consumed at a significant steady-state rate in the presence of both nanotubes and GSH. GSH deactivation occurs for single- and multi-walled nanotubes, graphene oxide, nanohorns, and carbon black at varying rates that are characteristic of the material. The GSH depletion rates can be partially unified by surface area normalization, are accelerated by nitrogen doping, and suppressed by defect annealing or addition of proteins or surfactants. It is proposed that dioxygen reacts with active sites on graphenic carbon surfaces to produce surface-bound oxygen intermediates that react heterogeneously with glutathione to restore the carbon surface and complete a catalytic cycle. The direct catalytic reaction between nanomaterial surfaces and antioxidants may contribute to oxidative stress pathways in nanotoxicity, and the dependence on surface area and structural defects suggest strategies for safe material design.

  13. Carotenoid biosynthesis regulatory mechanisms in plants.

    PubMed

    Othman, Rashidi; Mohd Zaifuddin, Fatimah Azzahra; Hassan, Norazian Mohd

    2014-01-01

    Carotenoids are bioactive compounds with remarkably special properties produced by plants in response to internal and external stresses. In this review paper, we focus on the subject of carotenoid biosynthesis and several factors that have been reported to significantly enhance or reduce carotenoid accumulation in studied plant species. These factors include varietal aspects, location, growing season, and type of stress experienced by a plant. In addition, we propose that there are three stress resistance mechanisms in plants: avoidance, tolerance, and acclimation. Better understanding of the environmental factors affecting carotenoid biosynthesis will help researchers to develop methods for enhancing the production of carotenoids and other pigments to desired concentrations in plant crops.

  14. Multichannel error correction code decoder

    NASA Technical Reports Server (NTRS)

    Wagner, Paul K.; Ivancic, William D.

    1993-01-01

    A brief overview of a processing satellite for a mesh very-small-aperture (VSAT) communications network is provided. The multichannel error correction code (ECC) decoder system, the uplink signal generation and link simulation equipment, and the time-shared decoder are described. The testing is discussed. Applications of the time-shared decoder are recommended.

  15. Chromoplast biogenesis and carotenoid accumulation

    USDA-ARS?s Scientific Manuscript database

    Chromoplasts are special organelles that possess superior ability to synthesize and store massive amounts of carotenoids. They are responsible for the distinctive colors found in fruits, flowers, and roots. Chromoplasts exhibit various morphologies and are derived from either pre-existing chloroplas...

  16. Carotenoid metabolism and regulation in horticultural crops

    PubMed Central

    Yuan, Hui; Zhang, Junxiang; Nageswaran, Divyashree; Li, Li

    2015-01-01

    Carotenoids are a diverse group of pigments widely distributed in nature. The vivid yellow, orange, and red colors of many horticultural crops are attributed to the overaccumulation of carotenoids, which contribute to a critical agronomic trait for flowers and an important quality trait for fruits and vegetables. Not only do carotenoids give horticultural crops their visual appeal, they also enhance nutritional value and health benefits for humans. As a result, carotenoid research in horticultural crops has grown exponentially over the last decade. These investigations have advanced our fundamental understanding of carotenoid metabolism and regulation in plants. In this review, we provide an overview of carotenoid biosynthesis, degradation, and accumulation in horticultural crops and highlight recent achievements in our understanding of carotenoid metabolic regulation in vegetables, fruits, and flowers. PMID:26504578

  17. Comparative biochemical studies of carotenoids in catfishes.

    PubMed

    Tsushima, M; Ikuno, Y; Nagata, S; Kodama, K; Matsuno, T

    2002-11-01

    The carotenoids of 12 species of Siluriformes fishes (eight families) were investigated from a comparative biochemical point of view. The patterns of carotenoids in catfishes belonging to the family Siluridae were quite different from those of the other seven families of catfishes (Bagridae, Amblycipitidae, Clariidae, Plotosidae, Ictaluridae, Callichthyidae and Malapteruridae). 7, 8-Dihydro-beta-carotene; 7, 8, 7', 8'- and 7, 8, 9, 10-tetrahydro-beta-carotene; (3R)-7', 8'-dihydro-beta-cryptoxanthin; 7, 8-dihydrolutein A; 7, 8-dihydrolutein B; parasiloxanthin; 7', 8'-dihydroparasiloxanthin; and 4 or 4'-hydroxyparasiloxanthin were characteristic carotenoids found in only one family, Siluridae, and these carotenoids accounted for 24-60% of total carotenoids. In catfishes belonging to the other seven families except Siluridae, the carotenoid patterns were very similar and the most predominant carotenoid was zeaxanthins (23-56%). Copyright 2002 Elsevier Science Inc.

  18. PUREX/UO{sub 3} deactivation project management plan

    SciTech Connect

    Washenfelder, D.J.

    1993-12-01

    From 1955 through 1990, the Plutonium-Uranium Extraction Plant (PUREX) provided the United States Department of Energy Hanford Site with nuclear fuel reprocessing capability. It operated in sequence with the Uranium Trioxide (UO{sub 3}) Plant, which converted the PUREX liquid uranium nitrate product to solid UO{sub 3} powder. Final UO{sub 3} Plant operation ended in 1993. In December 1992, planning was initiated for the deactivation of PUREX and UO{sub 3} Plant. The objective of deactivation planning was to identify the activities needed to establish a passively safe, environmentally secure configuration at both plants, and ensure that the configuration could be retained during the post-deactivation period. The PUREX/UO{sub 3} Deactivation Project management plan represents completion of the planning efforts. It presents the deactivation approach to be used for the two plants, and the supporting technical, cost, and schedule baselines. Deactivation activities concentrate on removal, reduction, and stabilization of the radioactive and chemical materials remaining at the plants, and the shutdown of the utilities and effluents. When deactivation is completed, the two plants will be left unoccupied and locked, pending eventual decontamination and decommissioning. Deactivation is expected to cost $233.8 million, require 5 years to complete, and yield $36 million in annual surveillance and maintenance cost savings.

  19. 10 CFR 218.2 - Activation/Deactivation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Activation/Deactivation. 218.2 Section 218.2 Energy DEPARTMENT OF ENERGY OIL STANDBY MANDATORY INTERNATIONAL OIL ALLOCATION General Provisions § 218.2 Activation/Deactivation. (a) This rule shall take effect providing: (1) The International Energy Program has been...

  20. 10 CFR 218.2 - Activation/Deactivation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Activation/Deactivation. 218.2 Section 218.2 Energy DEPARTMENT OF ENERGY OIL STANDBY MANDATORY INTERNATIONAL OIL ALLOCATION General Provisions § 218.2 Activation/Deactivation. (a) This rule shall take effect providing: (1) The International Energy Program has been...

  1. 10 CFR 218.2 - Activation/Deactivation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Activation/Deactivation. 218.2 Section 218.2 Energy DEPARTMENT OF ENERGY OIL STANDBY MANDATORY INTERNATIONAL OIL ALLOCATION General Provisions § 218.2 Activation/Deactivation. (a) This rule shall take effect providing: (1) The International Energy Program has been...

  2. 10 CFR 218.2 - Activation/Deactivation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Activation/Deactivation. 218.2 Section 218.2 Energy DEPARTMENT OF ENERGY OIL STANDBY MANDATORY INTERNATIONAL OIL ALLOCATION General Provisions § 218.2 Activation/Deactivation. (a) This rule shall take effect providing: (1) The International Energy Program has been...

  3. 10 CFR 218.2 - Activation/Deactivation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Activation/Deactivation. 218.2 Section 218.2 Energy DEPARTMENT OF ENERGY OIL STANDBY MANDATORY INTERNATIONAL OIL ALLOCATION General Provisions § 218.2 Activation/Deactivation. (a) This rule shall take effect providing: (1) The International Energy Program has been...

  4. Pacemaker deactivation: withdrawal of support or active ending of life?

    PubMed

    Huddle, Thomas S; Amos Bailey, F

    2012-12-01

    In spite of ethical analyses assimilating the palliative deactivation of pacemakers to commonly accepted withdrawings of life-sustaining therapy, many clinicians remain ethically uncomfortable with pacemaker deactivation at the end of life. Various reasons have been posited for this discomfort. Some cardiologists have suggested that reluctance to deactivate pacemakers may stem from a sense that the pacemaker has become part of the patient's "self." The authors suggest that Daniel Sulmasy is correct to contend that any such identification of the pacemaker is misguided. The authors argue that clinicians uncomfortable with pacemaker deactivation are nevertheless correct to see it as incompatible with the traditional medical ethics of withdrawal of support. Traditional medical ethics is presently taken by many to sanction pacemaker deactivation when such deactivation honors the patient's right to refuse treatment. The authors suggest that the right to refuse treatment applies to treatments involving ongoing physician agency. This right cannot underwrite patient demands that physicians reverse the effects of treatments previously administered, in which ongoing physician agency is no longer implicated. The permanently indwelling pacemaker is best seen as such a treatment. As such, its deactivation in the pacemaker-dependent patient is best seen not as withdrawal of support but as active ending of life. That being the case, clinicians adhering to the usual ethical analysis of withdrawal of support are correct to be uncomfortable with pacemaker deactivation at the end of life.

  5. Catalyst deactivation model for residual oil hydrodesulfurization

    SciTech Connect

    Takatsuka, T.; Higasino, S.; Hirohama, S.

    1995-12-31

    Hydrodesulfurization process plays a dominant role in the modern refineries to upgrade residual oil either by removing heterogeneous atoms or by hydrocracking the bottom to distillates products. The practical model is proposed to predict a catalyst life which is the most concern in the process. The catalyst is deactivated in the early stage of the operation by coke deposition on the catalyst active site. The ultimate catalyst life is determined by pore mouth plugging depending on its metal capacity. The phenomena are mathematically described by losses of catalyst surface area and effective diffusivity of feedstock molecules in catalyst pore. The model parameters were collected through the pilot plant tests with different types of catalysts and feedstocks.

  6. Deactivation of the EBR-II complex

    SciTech Connect

    Michelbacher, J.A.; Earle, O.K.; Henslee, S.P.

    1997-12-31

    In January of 1994, the Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Program, effective October 1, 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to place the Experimental Breeder Reactor-II (EBR-II) in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium, a liquid metal used to transfer heat within the reactor plant. The ultimate goal of the deactivation process is to place the EBR-II complex in a stable condition until a decontamination and decommissioning (D&D) plan can be prepared, thereby minimizing requirements for maintenance and surveillance and maximizing the amount of time for radioactive decay. The final closure state will be achieved in full compliance with federal, state and local environmental, safety, and health regulations and requirements. The decision to delay the development of a detailed D&D plan has necessitated this current action. The EBR-II is a pool-type reactor. The primary system contains approximately 87,000 gallons of sodium, while the secondary system has 13,000 gallons. In order to properly dispose of the sodium in compliance with the Resource Conservation and Recovery Act (RCRA), a facility has been built to react the sodium to a dry carbonate powder in a two stage process. Deactivation of a liquid metal fast breeder reactor (LMFBR) presents unique concerns. Residual amounts of sodium remaining in the primary and secondary systems must be either reacted or inerted to preclude future concerns with sodium-air reactions that generate explosive mixtures of hydrogen and leave corrosive compounds. Residual amounts of sodium on components will effectively {open_quotes}solder{close_quotes} components in place, making future operation or removal unfeasible.

  7. Carotenoids in Adipose Tissue Biology and Obesity.

    PubMed

    Bonet, M Luisa; Canas, Jose A; Ribot, Joan; Palou, Andreu

    2016-01-01

    Cell, animal and human studies dealing with carotenoids and carotenoid derivatives as nutritional regulators of adipose tissue biology with implications for the etiology and management of obesity and obesity-related metabolic diseases are reviewed. Most studied carotenoids in this context are β-carotene, cryptoxanthin, astaxanthin and fucoxanthin, together with β-carotene-derived retinoids and some other apocarotenoids. Studies indicate an impact of these compounds on essential aspects of adipose tissue biology including the control of adipocyte differentiation (adipogenesis), adipocyte metabolism, oxidative stress and the production of adipose tissue-derived regulatory signals and inflammatory mediators. Specific carotenoids and carotenoid derivatives restrain adipogenesis and adipocyte hypertrophy while enhancing fat oxidation and energy dissipation in brown and white adipocytes, and counteract obesity in animal models. Intake, blood levels and adipocyte content of carotenoids are reduced in human obesity. Specifically designed human intervention studies in the field, though still sparse, indicate a beneficial effect of carotenoid supplementation in the accrual of abdominal adiposity. In summary, studies support a role of specific carotenoids and carotenoid derivatives in the prevention of excess adiposity, and suggest that carotenoid requirements may be dependent on body composition.

  8. Carotenoid-based coloration in cichlid fishes

    PubMed Central

    Sefc, Kristina M.; Brown, Alexandria C.; Clotfelter, Ethan D.

    2014-01-01

    Animal colors play important roles in communication, ecological interactions and speciation. Carotenoid pigments are responsible for many yellow, orange and red hues in animals. Whereas extensive knowledge on the proximate mechanisms underlying carotenoid coloration in birds has led to testable hypotheses on avian color evolution and signaling, much less is known about the expression of carotenoid coloration in fishes. Here, we promote cichlid fishes (Perciformes: Cichlidae) as a system in which to study the physiological and evolutionary significance of carotenoids. Cichlids include some of the best examples of adaptive radiation and color pattern diversification in vertebrates. In this paper, we examine fitness correlates of carotenoid pigmentation in cichlids and review hypotheses regarding the signal content of carotenoid-based ornaments. Carotenoid-based coloration is influenced by diet and body condition and is positively related to mating success and social dominance. Gaps in our knowledge are discussed in the last part of this review, particularly in the understanding of carotenoid metabolism pathways and the genetics of carotenoid coloration. We suggest that carotenoid metabolism and transport are important proximate mechanisms responsible for individual and population-differences in cichlid coloration that may ultimately contribute to diversification and speciation. PMID:24667558

  9. Carotenoid depletion in serum of young type-1 diabetics fed low-carotenoid diets.

    PubMed

    Granado, F; Olmedilla, B; Blanco, I

    2004-01-01

    Type-1 diabetics have been considered to be at risk for increased oxidative stress which has been implicated in the development of long-term diabetes complications. Evidence suggests that antioxidant activity may be an important mechanism by which carotenoids could confer protection in human health. Our aim was to compare the serum carotenoid depletion rate in type-1 diabetics and control subjects consuming low-carotenoid diets. Ten type-1 diabetics and 8 controls followed a very low-carotenoid diet for 21 days. Dietary intake was recorded daily and fasting blood samples collected at baseline and after 1, 2, 3, 6, 11, 15, 16, 17, and 21 days. Individual carotenoids in serum were analyzed by a validated HPLC method. In both groups, carotenoid intake was less than 5% of the season-adjusted carotenoid reference intake. These diets resulted in decreased serum carotenoid levels in both groups, although depletion curves, final mean concentrations and the estimated half-life of carotenoids in serum revealed no differences between type-1 diabetics and controls. Levels of other minor serum carotenoids, cis-isomers and keto-carotenoids, also decreased whereas serum retinol and alpha- and gamma-tocopherol did not change during the study. Upon a low-carotenoid intake, the depletion rate of carotenoids in serum in young type-1 diabetics does not differ from that observed in matched related controls. Copyright (c) 2004 S. Karger AG, Basel.

  10. Multichannel Error Correction Code Decoder

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Lewis Research Center's Digital Systems Technology Branch has an ongoing program in modulation, coding, onboard processing, and switching. Recently, NASA completed a project to incorporate a time-shared decoder into the very-small-aperture terminal (VSAT) onboard-processing mesh architecture. The primary goal was to demonstrate a time-shared decoder for a regenerative satellite that uses asynchronous, frequency-division multiple access (FDMA) uplink channels, thereby identifying hardware and power requirements and fault-tolerant issues that would have to be addressed in a operational system. A secondary goal was to integrate and test, in a system environment, two NASA-sponsored, proof-of-concept hardware deliverables: the Harris Corp. high-speed Bose Chaudhuri-Hocquenghem (BCH) codec and the TRW multichannel demultiplexer/demodulator (MCDD). A beneficial byproduct of this project was the development of flexible, multichannel-uplink signal-generation equipment.

  11. Carotenoids in a Corynebacterineae, Gordonia terrae AIST-1: carotenoid glucosyl mycoloyl esters.

    PubMed

    Takaichi, Shinichi; Maoka, Takashi; Akimoto, Naoshige; Carmona, Marvelisa L; Yamaoka, Yukiho

    2008-10-01

    We isolated a strain of Corynebacterineae from surface seawater from the Inland Sea of Japan. This strain, AIST-1, was determined to be a strain of Gordonia terrae based on its 16S rRNA gene sequence. The colony was red-colored, and the pigments were identified to be carotenoid derivatives. The structures of two major carotenoids were (2'S)-deoxymyxol 1'-glucoside, a dihydroxyl derivative of gamma-carotene with 12 conjugated double bonds, and (2'S)-4-ketodeoxymyxol 1'-glucoside. Their glucosyl acyl esters and mycoloyl esters were also identified. While these carotenoid moieties have been found in only a few other bacteria, the carotenoid mycoloyl esters are novel carotenoid derivatives. The type strain of G. terrae NBRC 10016T also contained the same carotenoids, but the composition of the two carotenoid glucosides was low and the total carotenoid content was less than one tenth of that of strain AIST-1.

  12. Microalgae as Sources of Carotenoids

    PubMed Central

    Guedes, Ana Catarina; Amaro, Helena M.; Malcata, Francisco Xavier

    2011-01-01

    Marine microalgae constitute a natural source of a variety of drugs for pharmaceutical, food and cosmetic applications—which encompass carotenoids, among others. A growing body of experimental evidence has confirmed that these compounds can play important roles in prevention (and even treatment) of human diseases and health conditions, e.g., cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and some neurological disorders. The underlying features that may account for such favorable biological activities are their intrinsic antioxidant, anti-inflammatory and antitumoral features. In this invited review, the most important issues regarding synthesis of carotenoids by microalgae are described and discussed—from both physiological and processing points of view. Current gaps of knowledge, as well as technological opportunities in the near future relating to this growing field of interest, are also put forward in a critical manner. PMID:21731554

  13. Carotenoid changes of intact watermelons after storage.

    PubMed

    Perkins-Veazie, Penelope; Collins, Julie K

    2006-08-09

    Watermelon contains lycopene, a red carotenoid pigment that has strong antioxidant properties. The lycopene content of watermelon is substantial, contributing 8-20 mg per 180 g serving. There are no reports on carotenoid changes in whole watermelon during storage. Three types of watermelon, open-pollinated seeded, hybrid seeded, and seedless types, were stored at 5, 13, and 21 degrees C for 14 days and flesh color, composition, and carotenoid content were compared to those of fruit not stored. Watermelons stored at 21 degrees C had increased pH, chroma, and carotenoid content compared to fresh fruit. Compared to fresh fruit, watermelons stored at 21 degrees C gained 11-40% in lycopene and 50-139% in beta-carotene, whereas fruit held at 13 degrees C changed little in carotenoid content. These results indicate that carotenoid biosynthesis in watermelons can be affected by temperature and storage.

  14. Web-based multi-channel analyzer

    DOEpatents

    Gritzo, Russ E.

    2003-12-23

    The present invention provides an improved multi-channel analyzer designed to conveniently gather, process, and distribute spectrographic pulse data. The multi-channel analyzer may operate on a computer system having memory, a processor, and the capability to connect to a network and to receive digitized spectrographic pulses. The multi-channel analyzer may have a software module integrated with a general-purpose operating system that may receive digitized spectrographic pulses for at least 10,000 pulses per second. The multi-channel analyzer may further have a user-level software module that may receive user-specified controls dictating the operation of the multi-channel analyzer, making the multi-channel analyzer customizable by the end-user. The user-level software may further categorize and conveniently distribute spectrographic pulse data employing non-proprietary, standard communication protocols and formats.

  15. Carotenoids in Aquaculture: Fish and Crustaceans

    NASA Astrophysics Data System (ADS)

    Bjerkeng, Bjorn

    This Chapter deals with selected topics on the use of carotenoids for colouration in aquaculture and incudes examples from ecological studies which support our understanding of functions and actions of carotenoids and colouration in fishes and crustaceans. Animal colours may be physical or structural in origin [1], e.g. Tyndall blues and iridescent diffraction colours, or they may be due to pigments, including carotenoids (Chapter 10).

  16. Carotenoid photoprotection in artificial photosynthetic antennas.

    PubMed

    Kloz, Miroslav; Pillai, Smitha; Kodis, Gerdenis; Gust, Devens; Moore, Thomas A; Moore, Ana L; van Grondelle, Rienk; Kennis, John T M

    2011-05-11

    A series of phthalocyanine-carotenoid dyads in which a phenylamino group links a phthalocyanine to carotenoids having 8-11 backbone double bonds were examined by visible and near-infrared femtosecond pump-probe spectroscopy combined with global fitting analysis. The series of molecules has permitted investigation of the role of carotenoids in the quenching of excited states of cyclic tetrapyrroles. The transient behavior varied dramatically with the length of the carotenoid and the solvent environment. Clear spectroscopic signatures of radical species revealed photoinduced electron transfer as the main quenching mechanism for all dyads dissolved in a polar solvent (THF), and the quenching rate was almost independent of carotenoid length. However, in a nonpolar solvent (toluene), quenching rates displayed a strong dependence on the conjugation length of the carotenoid and the mechanism did not include charge separation. The lack of any rise time components of a carotenoid S(1) signature in all experiments in toluene suggests that an excitonic coupling between the carotenoid S(1) state and phthalocyanine Q state, rather than a conventional energy transfer process, is the major mechanism of quenching. A pronounced inhomogeneity of the system was observed and attributed to the presence of a phenyl-amino linker between phthalocyanine and carotenoids. On the basis of accumulated work on various caroteno-phthalocyanine dyads and triads, we have now identified three mechanisms of tetrapyrrole singlet excited state quenching by carotenoids in artificial systems: (i) Car-Pc electron transfer and recombination; (ii)(1) Pc to Car S(1) energy transfer and fast internal conversion to the Car ground state; (iii) excitonic coupling between (1)Pc and Car S(1) and ensuing internal conversion to the ground state of the carotenoid. The dominant mechanism depends upon the exact molecular architecture and solvent environment. These synthetic systems are providing a deeper understanding

  17. Multichannel analysis of surface waves

    USGS Publications Warehouse

    Park, C.B.; Miller, R.D.; Xia, J.

    1999-01-01

    The frequency-dependent properties of Rayleigh-type surface waves can be utilized for imaging and characterizing the shallow subsurface. Most surface-wave analysis relies on the accurate calculation of phase velocities for the horizontally traveling fundamental-mode Rayleigh wave acquired by stepping out a pair of receivers at intervals based on calculated ground roll wavelengths. Interference by coherent source-generated noise inhibits the reliability of shear-wave velocities determined through inversion of the whole wave field. Among these nonplanar, nonfundamental-mode Rayleigh waves (noise) are body waves, scattered and nonsource-generated surface waves, and higher-mode surface waves. The degree to which each of these types of noise contaminates the dispersion curve and, ultimately, the inverted shear-wave velocity profile is dependent on frequency as well as distance from the source. Multichannel recording permits effective identification and isolation of noise according to distinctive trace-to-trace coherency in arrival time and amplitude. An added advantage is the speed and redundancy of the measurement process. Decomposition of a multichannel record into a time variable-frequency format, similar to an uncorrelated Vibroseis record, permits analysis and display of each frequency component in a unique and continuous format. Coherent noise contamination can then be examined and its effects appraised in both frequency and offset space. Separation of frequency components permits real-time maximization of the S/N ratio during acquisition and subsequent processing steps. Linear separation of each ground roll frequency component allows calculation of phase velocities by simply measuring the linear slope of each frequency component. Breaks in coherent surface-wave arrivals, observable on the decomposed record, can be compensated for during acquisition and processing. Multichannel recording permits single-measurement surveying of a broad depth range, high levels of

  18. Foraging for carotenoids: do colorful male hihi target carotenoid-rich foods in the wild?

    PubMed Central

    Thorogood, Rose; Karadas, Filiz; Raubenheimer, David; Kilner, Rebecca M.; Ewen, John G.

    2014-01-01

    Dietary access to carotenoids is expected to determine the strength of carotenoid-based signal expression and potentially to maintain signal honesty. Species that display carotenoid-based yellow, orange, or red plumage are therefore expected to forage selectively for carotenoid-rich foods when they are depositing these pigments during molt, but whether they actually do so is unknown. We set out to address this in the hihi (Notiomystis cincta), a New Zealand passerine where males, but not females, display yellow carotenoid-based plumage. We measured circulating carotenoid concentrations in male and female hihi during breeding and molt, determined the nutritional content of common foods in the hihi diet, and conducted feeding observations of male and female hihi during molt. We found that although male and female hihi do not differ significantly in plasma carotenoid concentration, male hihi have a greater proportion of carotenoid-rich foods in their diet than do females. This is a consequence of a greater fruit and lower invertebrate intake than females and an avoidance of low-carotenoid content fruit. By combining behavioral observations with quantification of circulating carotenoids, we present evidence that colorful birds forage to maximize carotenoid intake, a conclusion we would not have drawn had we examined plasma carotenoids alone. PMID:25214753

  19. Foraging for carotenoids: do colorful male hihi target carotenoid-rich foods in the wild?

    PubMed

    Walker, Leila K; Thorogood, Rose; Karadas, Filiz; Raubenheimer, David; Kilner, Rebecca M; Ewen, John G

    2014-09-01

    Dietary access to carotenoids is expected to determine the strength of carotenoid-based signal expression and potentially to maintain signal honesty. Species that display carotenoid-based yellow, orange, or red plumage are therefore expected to forage selectively for carotenoid-rich foods when they are depositing these pigments during molt, but whether they actually do so is unknown. We set out to address this in the hihi (Notiomystis cincta), a New Zealand passerine where males, but not females, display yellow carotenoid-based plumage. We measured circulating carotenoid concentrations in male and female hihi during breeding and molt, determined the nutritional content of common foods in the hihi diet, and conducted feeding observations of male and female hihi during molt. We found that although male and female hihi do not differ significantly in plasma carotenoid concentration, male hihi have a greater proportion of carotenoid-rich foods in their diet than do females. This is a consequence of a greater fruit and lower invertebrate intake than females and an avoidance of low-carotenoid content fruit. By combining behavioral observations with quantification of circulating carotenoids, we present evidence that colorful birds forage to maximize carotenoid intake, a conclusion we would not have drawn had we examined plasma carotenoids alone.

  20. Highly n -doped silicon: Deactivating defects of donors

    NASA Astrophysics Data System (ADS)

    Mueller, D. Christoph; Fichtner, Wolfgang

    2004-12-01

    We report insight into the deactivation mechanisms of group V donors in heavily doped silicon. Based on our ab initio calculations, we suggest a three step model for the donor deactivation. In highly n -type Si grown at low temperatures, in the absence of excess native point defects, the intrinsic limit to ne seems to rise in part by means of donor deactivating distortions of the silicon lattice in the proximity of two or more donor atoms that share close sites. Also, donor dimers play an important part in the deactivation at high doping concentrations. While the dimers constitute a stable or metastable inactive donor configuration, the lattice distortions lower the donor levels gradually below the impurity band in degenerate silicon. On the other hand, we find that, in general, none of the earlier proposed deactivating donor pair defects is stable at any position of the Fermi level. The lattice distortions may be viewed as a precursor to Frenkel pair generation and donor-vacancy clustering process (step 2) that account for deactivation at elevated temperature and longer annealing times. Ultimately, and most prominently in the case of the large Sb atoms, precipitation of the donor atoms may set in as the last step of the deactivation process chain.

  1. Carotenoid Biosynthesis in Arabidopsis: A Colorful Pathway

    PubMed Central

    Ruiz-Sola, M. Águila; Rodríguez-Concepción, Manuel

    2012-01-01

    Plant carotenoids are a family of pigments that participate in light harvesting and are essential for photoprotection against excess light. Furthermore, they act as precursors for the production of apocarotenoid hormones such as abscisic acid and strigolactones. In this review, we summarize the current knowledge on the genes and enzymes of the carotenoid biosynthetic pathway (which is now almost completely elucidated) and on the regulation of carotenoid biosynthesis at both transcriptional and post-transcriptional levels. We also discuss the relevance of Arabidopsis as a model system for the study of carotenogenesis and how metabolic engineering approaches in this plant have taught important lessons for carotenoid biotechnology. PMID:22582030

  2. Deactivation of the EBR-II complex

    SciTech Connect

    Michelbacher, J A; Earle, O K; Henslee, S P; Wells, P B; Zahn, T P

    1996-01-01

    In January of 1994, the Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Program, effective October 1, 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to place the Experimental Breeder Reactor-II (EBR-II) in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium, a liquid metal used to transfer heat within the reactor plant. The ultimate goal of the deactivation process is to place the EBR-II complex in a stable condition until a decontamination and decommissioning (D and D) plan can be prepared, thereby minimizing requirements for maintenance and surveillance and maximizing the amount of time for radioactive decay. The final closure state will be achieved in full compliance with federal, state and local environmental, safety, and health regulations and requirements. The decision to delay the development of a detailed D and D plan has necessitated this current action.

  3. Extraction, Identification and Photo-Physical Characterization of Persimmon (Diospyros kaki L.) Carotenoids

    PubMed Central

    Zaghdoudi, Khalil; Ngomo, Orleans; Vanderesse, Régis; Arnoux, Philippe; Myrzakhmetov, Bauyrzhan; Frochot, Céline; Guiavarc’h, Yann

    2017-01-01

    Carotenoid pigments were extracted and purified from persimmon fruits using accelerated solvent extraction (ASE). Eleven pigments were isolated and five of them were clearly identified as all-trans-violaxanthine, all-trans-lutein, all-trans-zeaxanthin all-trans-cryptoxanthin and all-trans-β-carotene. Absorption and fluorescence spectra were recorded. To evaluate the potential of 1O2 quenching of the purified carotenoids, we used a monocarboxylic porphyrin (P1COOH) as the photosensitizer to produce 1O2. The rate constants of singlet oxygen quenching (Kq) were determined by monitoring the near-infrared (1270 nm) luminescence of 1O2 produced by photosensitizer excitation. The lifetime of singlet oxygen was measured in the presence of increasing concentrations of carotenoids in hexane. Recorded Kq values show that all-trans-β-cryptoxanthin, all-trans-β-carotene, all-trans-lycopene and all-trans-zeaxanthin quench singlet oxygen in hexane efficiently (associated Kq values of 1.6 × 109, 1.3 × 109, 1.1 × 109 and 1.1 × 109 M−1·s−1, respectively). The efficiency of singlet oxygen quenching of β-cryptoxanthin can thus change the consideration that β-carotene and lycopene are the most efficient singlet oxygen quenchers acting as catalysts for deactivation of the harmful 1O2. PMID:28231085

  4. Extraction, Identification and Photo-Physical Characterization of Persimmon (Diospyros kaki L.) Carotenoids.

    PubMed

    Zaghdoudi, Khalil; Ngomo, Orleans; Vanderesse, Régis; Arnoux, Philippe; Myrzakhmetov, Bauyrzhan; Frochot, Céline; Guiavarc'h, Yann

    2017-01-12

    Carotenoid pigments were extracted and purified from persimmon fruits using accelerated solvent extraction (ASE). Eleven pigments were isolated and five of them were clearly identified as all-trans-violaxanthine, all-trans-lutein, all-trans-zeaxanthin all-trans-cryptoxanthin and all-trans-β-carotene. Absorption and fluorescence spectra were recorded. To evaluate the potential of ¹O₂ quenching of the purified carotenoids, we used a monocarboxylic porphyrin (P1COOH) as the photosensitizer to produce ¹O₂. The rate constants of singlet oxygen quenching (Kq) were determined by monitoring the near-infrared (1270 nm) luminescence of ¹O₂ produced by photosensitizer excitation. The lifetime of singlet oxygen was measured in the presence of increasing concentrations of carotenoids in hexane. Recorded Kq values show that all-trans-β-cryptoxanthin, all-trans-β-carotene, all-trans-lycopene and all-trans-zeaxanthin quench singlet oxygen in hexane efficiently (associated Kq values of 1.6 × 10⁸, 1.3 × 10⁸, 1.1 × 10⁸ and 1.1 × 10⁸ M(-1)·s(-1), respectively). The efficiency of singlet oxygen quenching of β-cryptoxanthin can thus change the consideration that β-carotene and lycopene are the most efficient singlet oxygen quenchers acting as catalysts for deactivation of the harmful ¹O₂.

  5. The cyanobacterial Fluorescence Recovery Protein has two distinct activities: Orange Carotenoid Protein amino acids involved in FRP interaction.

    PubMed

    Thurotte, Adrien; Bourcier de Carbon, Céline; Wilson, Adjélé; Talbot, Léa; Cot, Sandrine; López-Igual, Rocio; Kirilovsky, Diana

    2017-04-01

    To deal with fluctuating light condition, cyanobacteria have developed a photoprotective mechanism which, under high light conditions, decreases the energy arriving at the photochemical centers. It relies on a photoswitch, the Orange Carotenoid Protein (OCP). Once photoactivated, OCP binds to the light harvesting antenna, the phycobilisome (PBS), and triggers the thermal dissipation of the excess energy absorbed. Deactivation of the photoprotective mechanism requires the intervention of a third partner, the Fluorescence Recovery Protein (FRP). FRP by interacting with the photoactivated OCP accelerates its conversion to the non-active form and its detachment from the phycobilisome. We have studied the interaction of FRP with free and phycobilisome-bound OCP. Several OCP variants were constructed and characterized. In this article we show that OCP amino acid F299 is essential and D220 important for OCP deactivation mediated by FRP. Mutations of these amino acids did not affect FRP activity as helper to detach OCP from phycobilisomes. In addition, while mutated R60L FRP is inactive on OCP deactivation, its activity on the detachment of the OCP from the phycobilisomes is not affected. Thus, our results demonstrate that FRP has two distinct activities: it accelerates OCP detachment from phycobilisomes and then it helps deactivation of the OCP. They also suggest that different OCP and FRP amino acids could be involved in these two activities.

  6. 340 waste handling complex: Deactivation project management plan

    SciTech Connect

    Stordeur, R.T.

    1998-06-25

    This document provides an overview of the strategy for deactivating the 340 Waste Handling Complex within Hanford`s 300 Area. The plan covers the period from the pending September 30, 1998 cessation of voluntary radioactive liquid waste (RLW) transfers to the 340 Complex, until such time that those portions of the 340 Complex that remain active beyond September 30, 1998, specifically, the Retention Process Sewer (RPS), can also be shut down and deactivated. Specific activities are detailed and divided into two phases. Phase 1 ends in 2001 after the core RLW systems have been deactivated. Phase 2 covers the subsequent interim surveillance of deactivated and stand-by components during the period of continued RPS operation, through the final transfer of the entire 340 Complex to the Environmental Restoration Contractor. One of several possible scenarios was postulated and developed as a budget and schedule planning case.

  7. Design of waste deactivation systems for biopharmaceutical manufacturing facilities

    SciTech Connect

    Nghiem, N.P.

    1995-12-01

    Waste deactivation system is an essential part of any biopharmaceutical manufacturing facility. Regulations require that all genetically engineered bacteria or cells be killed before the waste can be discharged from the facility. This is typically accomplished by heat or chemicals. In a small facility, a batch heat kill system normally is used. In larger facilities, continuous systems are preferred. In both systems, the most critical parameters are capacity and cycle time. These parameters must be carefully determined when designing a heat kill system. Heat-deactivated wastes sometimes cause odor problems, especially in the case of a facility located near a residential area. These problems can be alleviated by using chemicals. Among these, ozone is the most promising one because it can be generated on-site when needed, is easy to handle, and leaves no residual in the deactivated wastes. Design of heat kill and ozone deactivation systems will be discussed.

  8. Deactivation of Pacemakers and Implantable Cardioverter-Defibrillators

    PubMed Central

    Kramer, Daniel B.; Mitchell, Susan L.; Brock, Dan W.

    2013-01-01

    Cardiac implantable electrical devices (CIEDs), including pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs), are the most effective treatment for life-threatening arrhythmias. Patients or their surrogates may request device deactivation to avoid prolongation of the dying process or in other settings, such as after device-related complications or with changes in their health care goals. Despite published guidelines outlining theoretical and practical aspects of this common clinical scenario, significant uncertainty remains for both patients and health care providers regarding the ethical and legal status of CIED deactivation. This review outlines the ethical and legal principles supporting CIED deactivation at patients’ request, centered upon patient autonomy and authority over their own medical treatment. The empirical literature describing stakeholder views and experiences surrounding CIED deactivation is described, along with lessons for future research and practice guidance surrounding the care of patients with CIEDs. PMID:23217433

  9. [Deactivation of titania whiskers used for purification of drinking water].

    PubMed

    Wen, Gao-fei; Yang, Zhu-hong; Li, Wei; Feng, Xin; Lu, Xiao-hua

    2007-09-01

    The reason of deactivation of titania whiskers used for deep purification of drinking water and the corresponding regeneration methods were presented. AFM, XRD and ICP were carried out to characterize the titanium dioxide. The experimental results suggest that the main reason of deactivation of titania whiskers is the deposition of calcium carbonate on the catalyst surface. The surface of titania whiskers is covered by the insoluble carbonates generated from carbon dioxide produced during the degradation of organics and metal ions such as calcium in the tap water, and the activity of the titania whiskers decreases gradually till deactivation. After washing by 1 mol/L hydrochloric acid for four hours, the photocatalytic activity of the titania whiskers can achieve 95 percent of that before deactivation. The photocatalytic activity of the titania whiskers which regenerated for many times keeps steady.

  10. 1997 project of the year, PUREX deactivation project

    SciTech Connect

    Bailey, R.W.

    1998-02-13

    At the end of 1992, the PUREX and UO{sub 3} plants were deemed no longer necessary for the defense needs of the United States. Although no longer necessary, they were very costly to maintain in their post-operation state. The DOE embarked on a deactivation strategy for these plants to reduce the costs of providing continuous surveillance of the facilities and their hazards. Deactivation of the PUREX and UO{sub 3} plants was estimated to take 5 years and cost $222.5 million and result in an annual surveillance and maintenance cost of $2 million. Deactivation of the PUREX/UO{sub 3} plants officially began on October 1, 1993. The deactivation was 15 months ahead of the original schedule and $75 million under the original cost estimate. The annual cost of surveillance and maintenance of the plants was reduced to less than $1 million.

  11. Material identification with multichannel radiographs

    NASA Astrophysics Data System (ADS)

    Collins, Noelle; Jimenez, Edward S.; Thompson, Kyle R.

    2017-02-01

    This work aims to validate previous exploratory work done to characterize materials by matching their attenuation profiles using a multichannel radiograph given an initial energy spectrum. The experiment was performed in order to evaluate the effects of noise on the resulting attenuation profiles, which was ignored in simulation. Spectrum measurements have also been collected from various materials of interest. Additionally, a MATLAB optimization algorithm has been applied to these candidate spectrum measurements in order to extract an estimate of the attenuation profile. Being able to characterize materials through this nondestructive method has an extensive range of applications for a wide variety of fields, including quality assessment, industry, and national security.

  12. Multichanneled puzzle-like encryption

    NASA Astrophysics Data System (ADS)

    Amaya, Dafne; Tebaldi, Myrian; Torroba, Roberto; Bolognini, Néstor

    2008-07-01

    In order to increase data security transmission we propose a multichanneled puzzle-like encryption method. The basic principle relies on the input information decomposition, in the same way as the pieces of a puzzle. Each decomposed part of the input object is encrypted separately in a 4 f double random phase mask architecture, by setting the optical parameters in a determined status. Each parameter set defines a channel. In order to retrieve the whole information it is necessary to properly decrypt and compose all channels. Computer simulations that confirm our proposal are presented.

  13. Carotenoid metabolism and regulation in horticultural crops

    USDA-ARS?s Scientific Manuscript database

    Carotenoids are a diverse group of pigments widely distributed in nature. The vivid yellow, orange, and red colors in many horticultural crops attribute to overaccumulation of carotenoids, which contribute to a critical agronomic trait for flowers and an important quality trait for fruits and vegeta...

  14. Carotenoids in Algae: Distributions, Biosyntheses and Functions

    PubMed Central

    Takaichi, Shinichi

    2011-01-01

    For photosynthesis, phototrophic organisms necessarily synthesize not only chlorophylls but also carotenoids. Many kinds of carotenoids are found in algae and, recently, taxonomic studies of algae have been developed. In this review, the relationship between the distribution of carotenoids and the phylogeny of oxygenic phototrophs in sea and fresh water, including cyanobacteria, red algae, brown algae and green algae, is summarized. These phototrophs contain division- or class-specific carotenoids, such as fucoxanthin, peridinin and siphonaxanthin. The distribution of α-carotene and its derivatives, such as lutein, loroxanthin and siphonaxanthin, are limited to divisions of Rhodophyta (macrophytic type), Cryptophyta, Euglenophyta, Chlorarachniophyta and Chlorophyta. In addition, carotenogenesis pathways are discussed based on the chemical structures of carotenoids and known characteristics of carotenogenesis enzymes in other organisms; genes and enzymes for carotenogenesis in algae are not yet known. Most carotenoids bind to membrane-bound pigment-protein complexes, such as reaction center, light-harvesting and cytochrome b6f complexes. Water-soluble peridinin-chlorophyll a-protein (PCP) and orange carotenoid protein (OCP) are also established. Some functions of carotenoids in photosynthesis are also briefly summarized. PMID:21747749

  15. Method of producing purified carotenoid compounds

    NASA Technical Reports Server (NTRS)

    Eggink, Laura (Inventor)

    2007-01-01

    A method of producing a carotenoid in solid form includes culturing a strain of Chlorophyta algae cells in a minimal inorganic medium and separating the algae comprising a solid form of carotenoid. In one embodiment f the invention, the strain of Chlorophyta algae cells includes a strain f Chlamydomonas algae cells.

  16. Functional properties of carotenoids originating from algae.

    PubMed

    Christaki, Efterpi; Bonos, Eleftherios; Giannenas, Ilias; Florou-Paneri, Panagiota

    2013-01-15

    Carotenoids are isoprenoid molecules which are synthesised de novo by photosynthetic plants, fungi and algae and are responsible for the orange, yellow and some red colours of various fruits and vegetables. Carotenoids are lipophilic compounds, some of which act as provitamins A. These compounds can be divided into xanthophylls and carotenes. Many macroalgae and microalgae are rich in carotenoids, where these compounds aid in the absorption of sunlight. Industrially, these carotenoids are used as food pigments (in dairy products, beverages, etc.), as feed additives, in cosmetics and in pharmaceuticals, especially nowadays when there is an increasing demand by consumers for natural products. Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation. Recently, there has been considerable interest in dietary carotenoids with respect to their antioxidant properties and their ability to reduce the incidence of some chronic diseases where free radicals are involved. Possibly, carotenoids protect cells from oxidative stress by quenching singlet oxygen damage with various mechanisms. Therefore, carotenoids derived from algae could be a leading natural resource in the research for potential functional ingredients. Copyright © 2012 Society of Chemical Industry.

  17. Some kinetic aspects of the processes accompanied by catalyst deactivation

    SciTech Connect

    Kumbilieva, K.; Petrov, L.; Kiperman, S.L.

    1995-01-01

    Continuing our previous works, we performed a general analysis of the joint effect of the catalyst deactivation and intraparticle diffusion resistance leading to a retardation of the reactions. A significant effect of the mechanism of model reactions under study on the character of changes in the rate and selectivity of deactivation processes is demonstrated, with a number of examples proving the fruitfulness of such an approach. The problems arising and the possibilities and prospects for further investigations are discussed.

  18. Automated Activation and Deactivation of a System Under Test

    NASA Technical Reports Server (NTRS)

    Poff, Mark A.

    2006-01-01

    The MPLM Automated Activation/Deactivation application (MPLM means Multi-Purpose Logistic Module) was created with a three-fold purpose in mind: 1. To reduce the possibility of human error in issuing commands to, or interpreting telemetry from, the MPLM power, computer, and environmental control systems; 2. To reduce the amount of test time required for the repetitive activation/deactivation processes; and 3. To reduce the number of on-console personnel required for activation/ deactivation. All of these have been demonstrated with the release of the software. While some degree of automated end-item commanding had previously been performed for space-station hardware in the test environment, none approached the functionality and flexibility of this application. For MPLM activation, it provides mouse-click selection of the hardware complement to be activated, activates the desired hardware and verifies proper feedbacks, and alerts the user when telemetry indicates an error condition or manual intervention is required. For MPLM deactivation, the product senses which end items are active and deactivates them in the proper sequence. For historical purposes, an on-line log is maintained of commands issued and telemetry points monitored. The benefits of the MPLM Automated Activation/ Deactivation application were demonstrated with its first use in December 2002, when it flawlessly performed MPLM activation in 8 minutes (versus as much as 2.4 hours for previous manual activations), and performed MPLM deactivation in 3 minutes (versus 66 minutes for previous manual deactivations). The number of test team members required has dropped from eight to four, and in actuality the software can be operated by a sole (knowledgeable) system engineer.

  19. Multichannel Analyzer Built from a Microcomputer.

    ERIC Educational Resources Information Center

    Spencer, C. D.; Mueller, P.

    1979-01-01

    Describes a multichannel analyzer built using eight-bit S-100 bus microcomputer hardware. The output modes are an oscilloscope display, print data, and send data to another computer. Discusses the system's hardware, software, costs, and advantages relative to commercial multichannels. (Author/GA)

  20. Multichannel Learning: Connecting All to Education.

    ERIC Educational Resources Information Center

    Anzalone, Steve, Ed.

    Drafted for the Learning Technologies for Basic Education project, this document assembles case studies which provide an overview of multichannel learning, or reinforce learning through the use of several instructional paths and various media including print, broadcast, and online. Through the cases, multichannel learning is depicted as an…

  1. Multichannel Compression, Temporal Cues, and Audibility.

    ERIC Educational Resources Information Center

    Souza, Pamela E.; Turner, Christopher W.

    1998-01-01

    The effect of the reduction of the temporal envelope produced by multichannel compression on recognition was examined in 16 listeners with hearing loss, with particular focus on audibility of the speech signal. Multichannel compression improved speech recognition when superior audibility was provided by a two-channel compression system over linear…

  2. A Student-Made Inexpensive Multichannel Pipet

    ERIC Educational Resources Information Center

    Dragojlovic, Veljko

    2009-01-01

    An inexpensive multichannel pipet designed to deliver small volumes of liquid simultaneously to wells in a multiwell plate can be prepared by students in a single laboratory period. The multichannel pipet is made of disposable plastic 1 mL syringes and drilled plastic plates, which are used to make plunger and barrel assemblies. Application of the…

  3. A Student-Made Inexpensive Multichannel Pipet

    ERIC Educational Resources Information Center

    Dragojlovic, Veljko

    2009-01-01

    An inexpensive multichannel pipet designed to deliver small volumes of liquid simultaneously to wells in a multiwell plate can be prepared by students in a single laboratory period. The multichannel pipet is made of disposable plastic 1 mL syringes and drilled plastic plates, which are used to make plunger and barrel assemblies. Application of the…

  4. Multichannel Analyzer Built from a Microcomputer.

    ERIC Educational Resources Information Center

    Spencer, C. D.; Mueller, P.

    1979-01-01

    Describes a multichannel analyzer built using eight-bit S-100 bus microcomputer hardware. The output modes are an oscilloscope display, print data, and send data to another computer. Discusses the system's hardware, software, costs, and advantages relative to commercial multichannels. (Author/GA)

  5. Least squares restoration of multichannel images

    NASA Technical Reports Server (NTRS)

    Galatsanos, Nikolas P.; Katsaggelos, Aggelos K.; Chin, Roland T.; Hillery, Allen D.

    1991-01-01

    Multichannel restoration using both within- and between-channel deterministic information is considered. A multichannel image is a set of image planes that exhibit cross-plane similarity. Existing optimal restoration filters for single-plane images yield suboptimal results when applied to multichannel images, since between-channel information is not utilized. Multichannel least squares restoration filters are developed using the set theoretic and the constrained optimization approaches. A geometric interpretation of the estimates of both filters is given. Color images (three-channel imagery with red, green, and blue components) are considered. Constraints that capture the within- and between-channel properties of color images are developed. Issues associated with the computation of the two estimates are addressed. A spatially adaptive, multichannel least squares filter that utilizes local within- and between-channel image properties is proposed. Experiments using color images are described.

  6. CAROTENOIDS AND THE VISUAL CYCLE

    PubMed Central

    Wald, George

    1935-01-01

    1. Carotenoids have been identified and their quantities measured in the eyes of several frog species. The combined pigment epithelium and choroid layer of an R. pipiens or esculenta eye contain about 1γ of xanthophyll and about 4γ of vitamin A. During light adaptation the xanthophyll content falls 10 to 20 per cent. 2. Light adapted retinas contain about 0.2–0.3 γ of vitamin A alone. 3. Dark adapted retinas contain only a trace of vitamin A. The destruction of their visual purple with chloroform liberates a hitherto undescribed carotenoid, retinene. The bleaching of visual purple to visual yellow by light also liberates retinene. Free retinene is removed from the isolated retina by two thermal processes: reversion to visual purple and decomposition to colorless products, including vitamin A. This is the source of the vitamin A of the light adapted retina. 4. Isolated retinas which have been bleached and allowed to fade completely contain several times as much vitamin A as retinas from light adapted animals. The visual purple system therefore expends vitamin A and is dependent upon the diet for its replacement. 5. Visual purple behaves as a conjugated protein in which retinene is the prosthetic group. 6. Vitamin A is the precursor of visual purple as well as the product of its decomposition. The visual processes therefore constitute a cycle. PMID:19872932

  7. Carotenoid gene expression explains the difference of carotenoid accumulation in carrot root tissues.

    PubMed

    Perrin, Florent; Hartmann, Laura; Dubois-Laurent, Cécile; Welsch, Ralf; Huet, Sébastien; Hamama, Latifa; Briard, Mathilde; Peltier, Didier; Gagné, Séverine; Geoffriau, Emmanuel

    2017-04-01

    Main conclusion Variations in gene expression can partially explain the difference of carotenoid accumulation in secondary phloem and xylem of fleshy carrot roots. The carrot root is well divided into two different tissues separated by vascular cambium: the secondary phloem and xylem. The equilibrium between these two tissues represents an important issue for carrot quality, but the knowledge about the respective carotenoid accumulation is sparse. The aim of this work was (i) to investigate if variation in carotenoid biosynthesis gene expression could explain differences in carotenoid content in phloem and xylem tissues and (ii) to investigate if this regulation is differentially modulated in the respective tissues by water-restricted growing conditions. In this work, five carrot genotypes contrasting by their root color were studied in control and water-restricted conditions. Carotenoid content and the relative expression of 13 genes along the carotenoid biosynthesis pathway were measured in the respective tissues. Results showed that in orange genotypes and the purple one, carotenoid content was higher in phloem compared to xylem. For the red one, no differences were observed. Moreover, in control condition, variations in gene expression explained the different carotenoid accumulations in both tissues, while in water-restricted condition, no clear association between gene expression pattern and variations in carotenoid content could be detected except in orange-rooted genotypes. This work shows that the structural aspect of carrot root is more important for carotenoid accumulation in relation with gene expression levels than the consequences of expression changes upon water restriction.

  8. Implementation of a Peltier-based cooling device for localized deep cortical deactivation during in vivo object recognition testing

    NASA Astrophysics Data System (ADS)

    Marra, Kyle; Graham, Brett; Carouso, Samantha; Cox, David

    2012-02-01

    While the application of local cortical cooling has recently become a focus of neurological research, extended localized deactivation deep within brain structures is still unexplored. Using a wirelessly controlled thermoelectric (Peltier) device and water-based heat sink, we have achieved inactivating temperatures (<20 C) at greater depths (>8 mm) than previously reported. After implanting the device into Long Evans rats' basolateral amygdala (BLA), an inhibitory brain center that controls anxiety and fear, we ran an open field test during which anxiety-driven behavioral tendencies were observed to decrease during cooling, thus confirming the device's effect on behavior. Our device will next be implanted in the rats' temporal association cortex (TeA) and recordings from our signal-tracing multichannel microelectrodes will measure and compare activated and deactivated neuronal activity so as to isolate and study the TeA signals responsible for object recognition. Having already achieved a top performing computational face-recognition system, the lab will utilize this TeA activity data to generalize its computational efforts of face recognition to achieve general object recognition.

  9. The Importance of Carotenoid Dose in Supplementation Studies with Songbirds.

    PubMed

    Koch, Rebecca E; Wilson, Alan E; Hill, Geoffrey E

    2016-01-01

    Carotenoid coloration is the one of the most frequently studied ornamental traits in animals. Many studies of carotenoid coloration test the associations between carotenoid coloration and measures of performance, such as immunocompetence and oxidative state, proceeding from the premise that carotenoids are limited resources. Such studies commonly involve supplementing the diets of captive birds with carotenoids. In many cases, however, the amount of carotenoid administered is poorly justified, and even supposedly carotenoid-limited diets may saturate birds' systems. To quantify the relationships among the amount of carotenoids administered in experiments, levels of circulating carotenoids, and quantities of carotenoids deposited into colored ornaments, we performed a meta-analysis of 15 published studies that supplemented carotenoids to one of seven songbird species. We used allometric scaling equations to estimate the per-gram carotenoid consumption of each study's subjects, and we used meta-regression to evaluate the effects of this carotenoid dose on differences in coloration and plasma carotenoid levels between supplemented and control groups of birds. After accounting for supplementation duration and species, we observed a significant positive correlation between carotenoid intake and response of plasma carotenoid level to supplementation. The presence of supplemental carotenoids also tended to increase the expression of ornamental coloration, but the magnitude of the carotenoid dose did not significantly affect how strongly coloration changed with supplementation. Further, coloration effect sizes had no significant relationship with plasma carotenoid effect sizes. We also found significant heterogeneity in responses among studies and species, and the parameters used to measure color significantly affected response to supplementation. Our results emphasize the importance of performing dosage trials to determine what supplementation levels provide limited

  10. Phytochrome-mediated Carotenoids Biosynthesis in Ripening Tomatoes.

    PubMed

    Thomas, R L; Jen, J J

    1975-09-01

    Red light induced and far red light inhibited carotenoid biosynthesis in ripening tomatoes (Lycopersicon esculentum Mill.) when compared to controls kept in the dark. Red illumination following far red illumination reversed the inhibitory action of far red light on carotenoid biosynthesis, suggesting a phytochrome-mediated process. Quantitation of individual carotenoids favored the hypothesis of two separate carotenoid biosynthetic pathways in tomatoes.

  11. Native carotenoids composition of some tropical fruits.

    PubMed

    Murillo, Enrique; Giuffrida, Daniele; Menchaca, Dania; Dugo, Paola; Torre, Germana; Meléndez-Martinez, Antonio J; Mondello, Luigi

    2013-10-15

    Many tropical fruits can be considered a reservoir of bioactive substances with a special interest due to their possible health-promoting properties. The interest in carotenoids from a nutritional standpoint has recently greatly increased, because of their important health benefits. Here we report the native carotenoids composition in six tropical fruits from Panama, which is considered a region of great biodiversity. The native carotenoid composition was directly investigated by an HPLC-DAD-APCI-MS methodology, for the first time. In Corozo 32 different carotenoids were detected, including a high content of β-carotene and lycopene. Sastra showed the highest content of zeaxanthin among the fruit investigated. In Sapote 22 different carotenoids were detected, including β-carotene and 10 different zeaxanthin-di-esters. Frutita showed a very high content of the apo-carotenoid β-citraurin, and of a number of its esters. In Maracuyà chino 14 carotenoids were detected, including a high amounts of mono-esterified lauric acid with β-cryptoxanthin and with cryptocapsin. Mamey rojo was characterised by ketocarotenoids with κ rings, both hydroxylated and not hydroxylated.

  12. Carotenoids and health in older people.

    PubMed

    Woodside, Jayne V; McGrath, Alanna J; Lyner, Natalie; McKinley, Michelle C

    2015-01-01

    As the proportion of older people increases, so will chronic disease incidence and the proportion of the population living with disability. Therefore, new approaches to maintain health for as long as possible in this age group are required. Carotenoids are a group of polyphenolic compounds found predominantly in fruit and vegetables that have been proposed to have anti-inflammatory and antioxidant effects. Such properties may impact on the risk diseases which predominate in older people, and also ageing-related physiological changes. Working out the effect of carotenoid intake versus fruit and vegetable intake is difficult, and the strong correlation between individual carotenoid intakes also complicates any attempt to examine individual carotenoid health effects. Similarly, research to determine whether carotenoids consumed as supplements have similar benefits to increased dietary intake through whole foods, is still required. However, reviewing the recent evidence suggests that carotenoid intake and status are relatively consistently associated with reduced CVD risk, although β-carotene supplementation does not reduce CVD risk and increases lung cancer risk. Increased lycopene intake may reduce prostate cancer progression, with a potential role for carotenoids at other cancer sites. Lutein and zeaxanthin have a plausible role in the maintenance of eye health, whilst an association between carotenoid intake and cognitive and physical health appears possible, although research is limited to date. Given this accruing evidence base to support a specific role for certain carotenoids and ageing, current dietary advice to consume a diet rich in fruit and vegetables would appear prudent, and efforts maintained to encourage increased intake. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Multichannel laser-fiber vibrometer

    NASA Astrophysics Data System (ADS)

    Dudzik, Grzegorz; Waz, Adam; Kaczmarek, Pawel; Antonczak, Arkadiusz; Sotor, Jaroslaw; Krzempek, Karol; Sobon, Grzegorz; Abramski, Krzysztof M.

    2013-01-01

    For the last few years we were elaborating the laser-fiber vibrometer working at 1550 nm. Our main stress was directed towards different aspects of research: analysis of scattered light, efficient photodetection, optimization of the fiber-free space interfaces and signal processing. As a consequence we proposed the idea of a multichannel fiber vibrometer based on well developed telecommunication technique - Wavelength Division Multiplexing (WDM). One of the most important parts of a fiber-laser vibrometer is demodulation electronic section. The distortion, nonlinearity, offset and added noise of measured signal come from electronic circuits and they have direct influence on finale measuring results. We present the results of finished project "Developing novel laser-fiber monitoring technologies to prevent environmental hazards from vibrating objects" where we have constructed a 4-channel WDM laser-fiber vibrometer.

  14. Multichannel acousto-optical spectrometer

    NASA Astrophysics Data System (ADS)

    Carter, James A.; Pape, Dennis R.

    1992-08-01

    Photonic Systems Incorporated is currently fabricating a Multichannel Acousto-Optical Spectrometer (MCAOS) for NASA Goddard Space Flight Center. This instrument will be used as a frequency channelized radiometer for radio astronomy spectroscopy. It will analyze the spectrum of four independent radio frequency (RF) channels simultaneously and has potential for eight to as many as sixteen channels. Each channel will resolve the RF spectrum to one megahertz within its 1000 megahertz band. Dynamic range exceeding 30 dB will be achieved by quantizing detector photo-charge to 12 bits and accumulating data for large periods of time. Long time integration requires an optical bench optimized for stability and the use of temperature stabilization. System drift due to speckle interference is minimized by using a novel polarization switching Bragg cell.

  15. Carotenoid Photoprotection in Artificial Photosynthetic Antennas

    SciTech Connect

    Kloz, Miroslav; Pillai, Smitha; Kodis, Gerdenis; Gust, Devens; Moore, Thomas A.; Moore, Ana L.; van Grondelle, Rienk; Kennis, John T. M.

    2011-04-14

    A series of phthalocyanine-carotenoid dyads in which a phenylamino group links a phthalocyanine to carotenoids having 8-11 backbone double bonds were examined by visible and near-infrared femtosecond pump-probe spectroscopy combined with global fitting analysis. The series of molecules has permitted investigation of the role of carotenoids in the quenching of excited states of cyclic tetrapyrroles. The transient behavior varied dramatically with the length of the carotenoid and the solvent environment. Clear spectroscopic signatures of radical species revealed photoinduced electron transfer as the main quenching mechanism for all dyads dissolved in a polar solvent (THF), and the quenching rate was almost independent of carotenoid length. However, in a nonpolar solvent (toluene), quenching rates displayed a strong dependence on the conjugation length of the carotenoid and the mechanism did not include charge separation. The lack of any rise time components of a carotenoid S1 signature in all experiments in toluene suggests that an excitonic coupling between the carotenoid S1 state and phthalocyanine Q state, rather than a conventional energy transfer process, is the major mechanism of quenching. A pronounced inhomogeneity of the system was observed and attributed to the presence of a phenyl-amino linker between phthalocyanine and carotenoids. On the basis of accumulated work on various caroteno-phthalocyanine dyads and triads, we have now identified three mechanisms of tetrapyrrole singlet excited state quenching by carotenoids in artificial systems: (i) Car-Pc electron transfer and recombination; (ii)1Pc to Car S1 energy transfer and fast internal conversion to the Car ground state; (iii) excitonic coupling between 1Pc and Car S1 and ensuing internal conversion to the ground state of the carotenoid. The dominant mechanism depends upon the exact molecular architecture and solvent environment

  16. Extraction and chromatography of carotenoids from pumpkin.

    PubMed

    Seo, Jung Sook; Burri, Betty Jane C; Quan, Zhejiu; Neidlinger, Terry R

    2005-05-06

    Vitamin A deficiency is a health problem in Southeast Asia that can be corrected by feeding orange fruits and vegetables such as mango. Pumpkin is a traditional Korean food that is easy to store and is already believed to have health benefits. We extracted carotenoids from pumpkin by liquid-liquid extraction and by supercritical fluid extraction. We measured carotenoids by reversed-phase chromatography with diode array detection. The major carotenoid in pumpkin (> 80%) is beta-carotene, with lesser amounts of lutein, lycopene, alpha-carotene and cis-beta-carotene. Pumpkin is a rich source of beta-carotene and might be useful for preventing Vitamin A deficiency.

  17. Multi-channel polarized thermal emitter

    DOEpatents

    Lee, Jae-Hwang; Ho, Kai-Ming; Constant, Kristen P

    2013-07-16

    A multi-channel polarized thermal emitter (PTE) is presented. The multi-channel PTE can emit polarized thermal radiation without using a polarizer at normal emergence. The multi-channel PTE consists of two layers of metallic gratings on a monolithic and homogeneous metallic plate. It can be fabricated by a low-cost soft lithography technique called two-polymer microtransfer molding. The spectral positions of the mid-infrared (MIR) radiation peaks can be tuned by changing the periodicity of the gratings and the spectral separation between peaks are tuned by changing the mutual angle between the orientations of the two gratings.

  18. A Multichannel Bioluminescence Determination Platform for Bioassays.

    PubMed

    Kim, Sung-Bae; Naganawa, Ryuichi

    2016-01-01

    The present protocol introduces a multichannel bioluminescence determination platform allowing a high sample throughput determination of weak bioluminescence with reduced standard deviations. The platform is designed to carry a multichannel conveyer, an optical filter, and a mirror cap. The platform enables us to near-simultaneously determine ligands in multiple samples without the replacement of the sample tubes. Furthermore, the optical filters beneath the multichannel conveyer are designed to easily discriminate colors during assays. This optical system provides excellent time- and labor-efficiency to users during bioassays.

  19. Interrelationships between maternal carotenoid status and newborn infant macular pigment optical density and carotenoid status.

    PubMed

    Henriksen, Bradley S; Chan, Gary; Hoffman, Robert O; Sharifzadeh, Mohsen; Ermakov, Igor V; Gellermann, Werner; Bernstein, Paul S

    2013-08-15

    Deposition of the macular pigment carotenoids lutein and zeaxanthin in the human retina occurs early in life. In this study, we examined the interrelationships of maternal carotenoid status and newborn infant macular pigment levels and systemic carotenoid status. As a secondary measure, we also evaluated the effects of intrauterine growth restriction (IUGR) on carotenoid status in term newborn infants. We measured mother and infant skin carotenoids using resonance Raman spectroscopy (RRS), serum carotenoids by HPLC, and mother breast milk carotenoids by HPLC. We measured infant macular pigment levels using noninvasive blue light reflectometry. We enrolled 30 healthy term infants, their mothers, and 10 IUGR infants and their mothers. A subset of 16 infants was imaged for macular pigment optical density (MPOD). Infant serum zeaxanthin levels correlated with MPOD (r = 0.68, P = 0.007). Mother serum zeaxanthin levels correlated with infant MPOD (r = 0.59, P = 0.032). Infant and mother serum lutein did not correlate with MPOD. Mother-infant correlations were found for total serum carotenoids (r = 0.42, P = 0.020) and skin carotenoids (r = 0.48, P = 0.001). No difference was seen between IUGR infants and controls in total serum or skin carotenoids. Mothers of IUGR infants had lower total serum carotenoids (P = 0.019) and breast milk carotenoids than controls (P = 0.006). Our findings suggest that maternal zeaxanthin status may play a more important role than lutein status in macular pigment deposition in utero. Controlled trials are needed to determine whether maternal zeaxanthin prenatal supplementation can raise infant macular pigment levels and/or improve ocular function.

  20. Interrelationships Between Maternal Carotenoid Status and Newborn Infant Macular Pigment Optical Density and Carotenoid Status

    PubMed Central

    Henriksen, Bradley S.; Chan, Gary; Hoffman, Robert O.; Sharifzadeh, Mohsen; Ermakov, Igor V.; Gellermann, Werner; Bernstein, Paul S.

    2013-01-01

    Purpose. Deposition of the macular pigment carotenoids lutein and zeaxanthin in the human retina occurs early in life. In this study, we examined the interrelationships of maternal carotenoid status and newborn infant macular pigment levels and systemic carotenoid status. As a secondary measure, we also evaluated the effects of intrauterine growth restriction (IUGR) on carotenoid status in term newborn infants. Methods. We measured mother and infant skin carotenoids using resonance Raman spectroscopy (RRS), serum carotenoids by HPLC, and mother breast milk carotenoids by HPLC. We measured infant macular pigment levels using noninvasive blue light reflectometry. Results. We enrolled 30 healthy term infants, their mothers, and 10 IUGR infants and their mothers. A subset of 16 infants was imaged for macular pigment optical density (MPOD). Infant serum zeaxanthin levels correlated with MPOD (r = 0.68, P = 0.007). Mother serum zeaxanthin levels correlated with infant MPOD (r = 0.59, P = 0.032). Infant and mother serum lutein did not correlate with MPOD. Mother–infant correlations were found for total serum carotenoids (r = 0.42, P = 0.020) and skin carotenoids (r = 0.48, P = 0.001). No difference was seen between IUGR infants and controls in total serum or skin carotenoids. Mothers of IUGR infants had lower total serum carotenoids (P = 0.019) and breast milk carotenoids than controls (P = 0.006). Conclusions. Our findings suggest that maternal zeaxanthin status may play a more important role than lutein status in macular pigment deposition in utero. Controlled trials are needed to determine whether maternal zeaxanthin prenatal supplementation can raise infant macular pigment levels and/or improve ocular function. PMID:23838770

  1. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect

    Bartholomew, C H

    1991-02-14

    Progress is reported for a four-year fundamental investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which were to (1) determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation and (2) model the global rates of deactivation at the surface of the catalyst for the same catalysts. A computer-automated reactor system to be used in the kinetic and deactivation studies was designed, constructed and tested. Kinetic data for CO hydrogenation on unsupported, unpromoted iron, 99% Fe/1% Al{sub 2}O{sub 3}, and K-promoted 99% Fe/1% Al{sub 2}O{sub 3} catalysts were obtained as functions of temperature, reactant particle pressures and time. The activity/selectivity and kinetic data are consistent with those previously reported for supported, unpromoted and promoted iron. Two kinds of deactivation were observed during FT synthesis on these samples: (1) loss of surface area after reduction of unsupported, unpromoted iron at 400{degree}C and (2) loss of activity with time due to carbon deposition, especially in the case of K-promoted 99% Fe/1% A1{sub 2}O{sub 3}. Deactivation rate data were obtained for CO hydrogenation on promoted Fe as a function of time, temperature, and H{sub 2}/CO ratio. 50 refs., 24 figs., 5 tabs.

  2. Diagnosis of industrial catalyst deactivation by surface characterization techniques

    SciTech Connect

    Menon, P.G. . Lab. voor Petrochemische Techniek Chalmers Univ. of Technology, Goeteborg . Dept. of Engineering Chemistry)

    1994-06-01

    The exact nature of the catalyst surface and the various ways of catalyst deactivation are subjects of great scientific interest and enormous economic importance. A brief review like the present one has to be very selective, giving only the underlying principles and representative examples. The focus of this review is on industrial catalysts, in particular, on the most commonly used supported metal and mixed-oxide type catalysts. Here again, only typical examples are chosen and cited to illustrate the specific types of problems involved in catalyst deactivation and how these problems wee diagnosed by a judicious application of the experimental techniques available today. Of the types of catalyst deactivation caused by coking, poisoning, and solid-state transformations, the emphasis in this review is on the last type. Changes in the chemical composition of the catalyst surface, restructuring or reconstruction of the surface, phase transformations, gradual enrichment/depletion of a particular catalyst component on/from the catalyst surface, these are the topics of prominence in this review. Even here, emphasis is on normally unexpected or unsuspected types of deactivation and the catalyst metamorphosis produced by the catalytic reaction itself, as distinct from the purely thermal effects at the reaction temperature. This review is aimed to provide some essential background information and possibly to serve as a reference guide for trouble-shooting when a catalyst is deactivated for rather mysterious reasons. 147 refs.

  3. Intention Retrieval and Deactivation Following an Acute Psychosocial Stressor

    PubMed Central

    Walser, Moritz; Fischer, Rico; Goschke, Thomas; Kirschbaum, Clemens; Plessow, Franziska

    2013-01-01

    We often form intentions but have to postpone them until the appropriate situation for retrieval and execution has come, an ability also referred to as event-based prospective memory. After intention completion, our cognitive system has to deactivate no-more-relevant intention representations from memory to avoid interference with subsequent tasks. In everyday life, we frequently rely on these abilities also in stressful situations. Surprisingly, little is known about potential stress effects on these functions. Therefore, the present study aimed to examine the reliability of event-based prospective memory and of intention deactivation in conditions of acute psychosocial stress. To this aim, eighty-two participants underwent the Trier Social Stress Test, a standardized stress protocol, or a standardized control situation. Following this treatment, participants performed a computerized event-based prospective memory task with non-salient and focal prospective memory cues in order to assess prospective memory performance and deactivation of completed intentions. Although the stress group showed elevated levels of salivary cortisol as marker of a stress-related increase in hypothalamus-pituitary-adrenal axis activity throughout the cognitive testing period compared to the no-stress group, prospective memory performance and deactivation of completed intentions did not differ between groups. Findings indicate that cognitive control processes subserving intention retrieval and deactivation after completion may be mostly preserved even under conditions of acute stress. PMID:24386486

  4. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect

    Bartholomew, C.H.

    1991-01-10

    Although promoted cobalt and iron catalysts for Fischer-Tropsch (FT) synthesis of gasoline feedstock were first developed more than three decades ago, a major technical problem still limiting the commercial use of these catalysts today is carbon deactivation. This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which are to: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; and model the rates of deactivation of the same catalysts in fixed-bed reactors. To accomplish the above objectives, the project is divided into the following tasks: (1) determine the kinetics of reaction and of carbon deactivation during CO hydrogenation on Fe and Fe/K catalysts coated on monolith bodies. (2) Determine the reactivities and types of carbon deposited during reaction on the same catalysts from temperature-programmed-surface-reaction spectroscopy (TPSR) and transmission electron microscopy (TEM). Determine the types of iron carbides formed at various temperatures and H{sub 2}/CO ratios using x-ray diffraction and Moessbauer spectroscopy. (3) Develop mathematical deactivation models which include heat and mass transport contributions for FT synthesis is packed-bed reactors. Progress to date is described. 48 refs., 3 figs., 1 tab.

  5. Holographic films from carotenoid pigments

    NASA Astrophysics Data System (ADS)

    Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2014-02-01

    Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.

  6. Carotenoid maintenance handicap and the physiology of carotenoid-based signalisation of health.

    PubMed

    Vinkler, Michal; Albrecht, Tomás

    2010-01-01

    Despite a reasonable scientific interest in sexual selection, the general principles of health signalisation via ornamental traits remain still unresolved in many aspects. This is also true for the mechanism preserving honesty of carotenoid-based signals. Although it is widely accepted that this type of ornamentation reflects an allocation trade-off between the physiological utilisation of carotenoids (mainly in antioxidative processes) and their deposition in ornaments, some recent evidence suggests more complex interactions. Here, we further develop the models currently proposed to explain the honesty of carotenoid-based signalisation of heath status by adding the handicap principle concept regulated by testosterone. We propose that under certain circumstances carotenoids may be dangerous for the organism because they easily transform into toxic cleavage products. When reserves of other protective antioxidants are insufficient, physiological trade-offs may exist between maintenance of carotenoids for ornament expression and their removal from the body. Furthermore, we suggest that testosterone which enhances ornamentation by increasing carotenoid bioavailability may also promote oxidative stress and hence lower antioxidant reserves. The presence of high levels of carotenoids required for high-quality ornament expression may therefore represent a handicap and only individuals in prime health could afford to produce elaborate colourful ornaments. Although further testing is needed, this 'carotenoid maintenance handicap' hypothesis may offer a new insight into the physiological aspects of the relationship between carotenoid function, immunity and ornamentation.

  7. Carotenoid bioaccessibility in pulp and fresh juice from carotenoid-rich sweet oranges and mandarins.

    PubMed

    Rodrigo, María Jesús; Cilla, Antonio; Barberá, Reyes; Zacarías, Lorenzo

    2015-06-01

    Citrus fruits are a good source of carotenoids for the human diet; however, comparative studies of carotenoids in different citrus food matrices are scarce. In this work the concentration and bioaccessibility of carotenoids in sweet oranges and mandarins with marked differences in carotenoid composition were evaluated in pulp and compared to those in fresh juice. The pulp and juice of the red-fleshed Cara Cara sweet orange variety was highly rich in carotenes (mainly lycopene and phytoene) compared to standard Navel orange, while β-cryptoxanthin and phytoene predominated in mandarins. Total carotenoid content in the pulp of the ordinary Navel orange and in the red-fleshed Cara Cara orange, as well as in the Clementine mandarin were higher than in the corresponding juices, although individual carotenoids were differentially affected by juice preparation. Bioaccessibility of the bioactive carotenoids (the ones described to be absorbed by humans) was greater in both pulp and juice of the carotenoid-rich Cara Cara orange compared to the Navel orange while increasing levels of β-cryptoxanthin were detected in the bioaccessible fractions of pulp and juice of mandarins postharvest stored at 12 °C compared to freshly-harvested fruits. Overall, results indicated that higher soluble bioactive carotenoids from citrus fruits and, consequently, potential nutritional and health benefits are obtained by the consumption of pulp with respect to fresh juice.

  8. Carotenoid maintenance handicap and the physiology of carotenoid-based signalisation of health

    NASA Astrophysics Data System (ADS)

    Vinkler, Michal; Albrecht, Tomáš

    2010-01-01

    Despite a reasonable scientific interest in sexual selection, the general principles of health signalisation via ornamental traits remain still unresolved in many aspects. This is also true for the mechanism preserving honesty of carotenoid-based signals. Although it is widely accepted that this type of ornamentation reflects an allocation trade-off between the physiological utilisation of carotenoids (mainly in antioxidative processes) and their deposition in ornaments, some recent evidence suggests more complex interactions. Here, we further develop the models currently proposed to explain the honesty of carotenoid-based signalisation of heath status by adding the handicap principle concept regulated by testosterone. We propose that under certain circumstances carotenoids may be dangerous for the organism because they easily transform into toxic cleavage products. When reserves of other protective antioxidants are insufficient, physiological trade-offs may exist between maintenance of carotenoids for ornament expression and their removal from the body. Furthermore, we suggest that testosterone which enhances ornamentation by increasing carotenoid bioavailability may also promote oxidative stress and hence lower antioxidant reserves. The presence of high levels of carotenoids required for high-quality ornament expression may therefore represent a handicap and only individuals in prime health could afford to produce elaborate colourful ornaments. Although further testing is needed, this ‘carotenoid maintenance handicap’ hypothesis may offer a new insight into the physiological aspects of the relationship between carotenoid function, immunity and ornamentation.

  9. The ethics of unilateral implantable cardioverter defibrillators and cardiac resynchronization therapy with defibrillator deactivation: patient perspectives.

    PubMed

    Daeschler, Margaret; Verdino, Ralph J; Kirkpatrick, James N

    2017-08-01

    Decisions about deactivation of implantable cardioverter defibrillators (ICDs) are complicated. Unilateral do-not-resuscitate (DNR) orders (against patient/family wishes) have been ethically justified in cases of medical futility. Unilateral deactivation of ICDs may be seen as a logical extension of a unilateral DNR order. However, the ethical implications of unilateral ICD deactivation have not been explored. Sixty patients who had an ICD or cardiac resynchronization therapy with defibrillator (CRT-D) were interviewed at a quaternary medical centre outpatient electrophysiology practice. Survey questions addressed whether deactivation of defibrillator function was included in advanced directives, whether deactivation constitutes physician-assisted suicide, and whether unilateral deactivation can be ethically justified. Responses were elicited to scenarios in which defibrillation function was deactivated in different contexts (including patient request to deactivate, existing DNR, and unilateral deactivation). Only 15% of respondents had thought about device deactivation if they were to develop a serious illness from which they were not expected to recover. A majority (53%) had advance directives, but only one mentioned what to do with the device. However, a majority (78%) did not consider deactivation of an ICD shocking function against patients' wishes to be ethical or moral. Management of ICDs and CRT-Ds as patients near the end of their lives creates ethical dilemmas. Few patients consider device deactivation at end-of-life, although a large majority believes that unilateral deactivation is not ethical/moral, even in the setting of medical futility. Advance care planning for these patients should address device deactivation.

  10. PUREX/UO{sub 3} facilities deactivation lessons learned history

    SciTech Connect

    Hamrick, D.G.; Gerber, M.S.

    1995-01-01

    The Plutonium-Uranium Extraction (PUREX) Facility operated from 1956-1972, from 1983-1988, and briefly during 1989-1990 to produce for national defense at the Hanford Site in Washington State. The Uranium Trioxide (UO{sub 3}) Facility operated at the Hanford Site from 1952-1972, 1984-1988, and briefly in 1993. Both plants were ordered to permanent shutdown by the U.S. Department of Energy (DOE) in December 1992, thus initiating their deactivation phase. Deactivation is that portion of a facility`s life cycle that occurs between operations and final decontamination and decommissioning (D&D). This document details the history of events, and the lessons learned, from the time of the PUREX Stabilization Campaign in 1989-1990, through the end of the first full fiscal year (FY) of the deactivation project (September 30, 1994).

  11. Regeneration of a deactivated USY alkylation catalyst using supercritical isobutane

    SciTech Connect

    Daniel M. Ginosar; David N. Ghompson; Kyle C. Burch

    2005-01-01

    Off-line, in-situ alkylation activity recovery from a completely deactivated solid acid catalyst was examined in a continuous-flow reaction system employing supercritical isobutane. A USY zeolite catalyst was initially deactivated during the liquid phase alkylation of butene with isobutane in a single-pass reactor and then varying amounts of alkylation activity were recovered by passing supercritical isobutane over the catalyst bed at different reactivation conditions. Temperature, pressure and regeneration time were found to play important roles in the supercritical isobutane regeneration process when applied to a completely deactivated USY zeolite alkylation catalyst. Manipulation of the variables that influence solvent strength, diffusivity, surface desorption, hydride transfer rates, and coke aging, strongly influence regeneration effectiveness.

  12. Characterization of Deactivated Bio-oil Hydrotreating Catalysts

    SciTech Connect

    Wang, Huamin; Wang, Yong

    2015-10-06

    Deactivation of bio-oil hydrotreating catalysts remains a significant challenge because of the poor quality of pyrolysis bio-oil input for hydrotreating and understanding their deactivation mode is critical to developing improved catalysts and processes. In this research, we developed an understanding of the deactivation of two-step bio-oil hydrotreating catalysts (sulfided Ru/C and sulfided CoMo/C) through detailed characterization of the catalysts using various complimentary analytical techniques. Severe fouling of both catalysts by carbonaceous species was the major form of deactivation, which is consistent with the significant loss of surface area and pore volume of both deactivated catalysts and the significant increase of the bulk density. Further analysis of the carbonaceous species by thermogravimetric analysis and x-ray photoelectron spectroscopy indicated that the carbonaceous species was formed by condensation reaction of active species such as sugars and sugar derivatives (aldehydes and ketones) in bio-oil feedstock during bio-oil hydrotreating under the conditions and catalysts used. Microscopy results did not show metal sintering of the Ru/C catalyst. However, X-ray diffraction indicated a probable transformation of the highly-active CoMoS phase in the sulfided CoMo/C catalyst to Co8S9 and MoS2 phase with low activity. Loss of the active site by transport of inorganic elements from the bio-oil and the reactor construction material onto the catalyst surface also might be a cause of deactivation as indicated by elemental analysis of spent catalysts.

  13. Robot Work Platform for Large Hot Cell Deactivation

    SciTech Connect

    BITTEN, E.J.

    2000-05-01

    The 324 Building, located at the Hanford Site near Richland, Washington, is being deactivated to meet state and federal cleanup commitments. The facility is currently in its third year of a nine-year project to complete deactivation and closure for long-term surveillance and maintenance. The 324 building contains large hot cells that were used for high-radiation, high-contamination chemical process development and demonstrations. A major obstacle for the 324 deactivation project is the inability to effectively perform deactivation tasks within highly radioactive, contaminated environments. Current strategies use inefficient, resource intensive technologies that significantly impact the cost and schedule for deactivation. To meet mandated cleanup commitments, there is a need to deploy rapid, more efficient remote/robot technologies to minimize worker exposure, accelerate work tasks, and eliminate the need for multiple specialized tool design and procurement efforts. This paper describes the functions and performance requirements for a crane-deployed remote/robot Work Platform possessing full access capabilities. The remote/robot Work Platform will deploy commercially available off-the-shelf tools and end effectors to support Project cleanup goals and reduce overall project risk and cost. The intent of this system is to maximize the use of off-the-shelf technologies that minimize additional new, unproven, or novel designs. This paper further describes procurement strategy, the selection process, the selected technology, and the current status of the procurement and lessons learned. Funding, in part, has been provided by the US Department of Energy, Office of Science and Technology, Deactivation and Decommissioning Focus Area.

  14. A Multi-Channel Radar Receiver.

    DTIC Science & Technology

    1985-01-07

    Doppler weather radar I ’Multi-channel radar receiver -,, Dual frequency radar , Polarization...V ~ ’.= :• ’> . . S , . . .. - -. .° , . * . - . -. . . A Multi-Channel Radar Receiver 1. INTRODUCTION The 10-cm Doppler weather radar at AFGL is...cm Dual Frequency Doppler Weather Radar . Part I: The Radar System, AFGL-TR-82- 0321 (I). 4. Ussailis, J.S., Leiker, L.A.. Goodman, R.M. IV.

  15. Latin American food sources of carotenoids.

    PubMed

    Rodriguez-Amaya, D B

    1999-09-01

    Latin America has a wide variety of carotenogenic foods, notable for the diversity and high levels of carotenoids. A part of this natural wealth has been analyzed. Carrot, red palm oil and some cultivars of squash and pumpkin are sources of both beta-carotene and alpha-carotene. beta-carotene is the principal carotenoid of the palm fruits burití, tucumã and bocaiuva, other fruits such as loquat, marolo and West Indian cherry, and sweet potato. Buriti also has high amounts of alpha-carotene and gamma-carotene. beta-Cryptoxanthin is the major carotenoid in caja, nectarine, orange-fleshed papaya, orange, peach, tangerine and the tree tomato. Lycopene predominates in tomato, red-fleshed papaya, guava, pitanga and watermelon. Pitanga also has substantial amounts of beta-cryptoxanthin, gamma-carotene and rubixanthin. Zeaxanthin, principal carotenoid of corn, is also predominant only in piquí. delta-Carotene is the main carotenoid of the peach palm and zeta-carotene of passion fruit. Lutein and beta-carotene, in high concentrations, are encountered in the numerous leafy vegetables of the region, as well as in other green vegetables and in some varieties of squash and pumpkin. Violaxanthin is the principal carotenoid of mango and mamey and is also found in appreciable amounts in green vegetables. Quantitative, in some cases also qualitative, differences exist among cultivars of the same food. Generally, carotenoids are in greater concentrations in the peel than in the pulp, increase considerably during ripening and are in higher levels in foods produced in hot places. Other Latin America indigenous carotenogenic foods must be investigated before they are supplanted by introduced crops, which are often poorer sources of carotenoids.

  16. Coprophagy: an unusual source of essential carotenoids.

    PubMed

    Negro, J J; Grande, J M; Tella, J L; Garrido, J; Hornero, D; Donázar, J A; Sanchez-Zapata, J A; BenItez, J R; Barcell, M

    2002-04-25

    The rare Egyptian vulture (Neophron percnopterus) stands out among the Old World vultures (Family Accipitridae) because of its brightly ornamented head, which is coloured yellow by carotenoid pigments, and its practice of feeding on faeces. Here we show that Egyptian vultures obtain these pigments from the excrement of ungulates. To our knowledge, this is the first demonstration that faeces can be used as a source of carotenoids by a vertebrate.

  17. PUREX/UO{sub 3} facilities deactivation lessons learned: History

    SciTech Connect

    Gerber, M.S.

    1997-11-25

    In May 1997, a historic deactivation project at the PUREX (Plutonium URanium EXtraction) facility at the Hanford Site in south-central Washington State concluded its activities (Figure ES-1). The project work was finished at $78 million under its original budget of $222.5 million, and 16 months ahead of schedule. Closely watched throughout the US Department of Energy (DOE) complex and by the US Department of Defense for the value of its lessons learned, the PUREX Deactivation Project has become the national model for the safe transition of contaminated facilities to shut down status.

  18. Systems and methods for deactivating a matrix converter

    SciTech Connect

    Ransom, Ray M.

    2013-04-02

    Systems and methods are provided for deactivating a matrix conversion module. An electrical system comprises an alternating current (AC) interface, a matrix conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the matrix conversion module, and a control module. The control module is coupled to the matrix conversion module, and in response to a shutdown condition, the control module is configured to operate the matrix conversion module to deactivate the first conversion module when a magnitude of a current through the inductive element is less than a threshold value.

  19. Multichannel Magnetorelaxometry In Vivo Monitoring of Magnetic Nanoparticle Quantity for Thermal Ablation Studies

    NASA Astrophysics Data System (ADS)

    Richter, Heike; Kettering, Melanie; Wiekhorst, Frank; Kosch, Olaf; Hilger, Ingrid; Trahms, Lutz

    2010-12-01

    To inactivate cancer cells with minimal side-effects to the normal tissue, cancer therapy as magnetic thermal ablation utilizes superparamagnetic iron oxide nanoparticles (MNP) injected into the tumor. When exposed to an externally applied alternating magnetic field MNP generate heat, which deactivates cellular processes or even generates lethal thermal doses. Hence, the intratumoral quantity of MNP needs to be thoroughly controlled to govern adequate heat production in the carcinoma region. Here, we investigate the capability of multichannel magnetorelaxometry (MRX) for quantitative measurement of MNP accumulation in the tumor region performed in vivo on a carcinoma mouse, and moreover, the feasibility of quantitative long-term monitoring of MNP amount in a conscious, freely moving mouse.

  20. Note: an underwater multi-channel plasma array for water sterilization.

    PubMed

    Yang, Y; Kim, H; Starikovskiy, A; Cho, Y I; Fridman, A

    2011-09-01

    A simple yet effective method to generate multi-channel plasma array in water is presented in this paper. Thin circular metal disks sandwiched between dielectric layers were used, allowing the production of large-volume underwater plasma array with higher stability. The system can be further scaled up by stacking multiple metal disks, making it suitable for large-scale industrial water treatment. Generation of UV and reactive species was identified by optical emission spectroscopy. Sterilization experiments were performed. Results show that the device was effective in deactivating E. coli in water over a wide range of initial concentrations ranging from 10(4) to 10(8) CFU/ml. © 2011 American Institute of Physics

  1. Correlations Between Macular, Skin, and Serum Carotenoids

    PubMed Central

    Conrady, Christopher D.; Bell, James P.; Besch, Brian M.; Gorusupudi, Aruna; Farnsworth, Kelliann; Ermakov, Igor; Sharifzadeh, Mohsen; Ermakova, Maia; Gellermann, Werner; Bernstein, Paul S.

    2017-01-01

    Purpose Ocular and systemic measurement and imaging of the macular carotenoids lutein and zeaxanthin have been employed extensively as potential biomarkers of AMD risk. In this study, we systematically compare dual wavelength retinal autofluorescence imaging (AFI) of macular pigment with skin resonance Raman spectroscopy (RRS) and serum carotenoid levels in a clinic-based population. Methods Eighty-eight patients were recruited from retina and general ophthalmology practices from a tertiary referral center and excluded only if they did not have all three modalities tested, had a diagnosis of macular telangiectasia (MacTel) or Stargardt disease, or had poor AFI image quality. Skin, macular, and serum carotenoid levels were measured by RRS, AFI, and HPLC, respectively. Results Skin RRS measurements and serum zeaxanthin concentrations correlated most strongly with AFI macular pigment volume under the curve (MPVUC) measurements up to 9° eccentricity relative to MPVUC or rotationally averaged macular pigment optical density (MPOD) measurements at smaller eccentricities. These measurements were reproducible and not significantly affected by cataracts. We also found that these techniques could readily identify subjects taking oral carotenoid-containing supplements. Conclusions Larger macular pigment volume AFI and skin RRS measurements are noninvasive, objective, and reliable methods to assess ocular and systemic carotenoid levels. They are an attractive alternative to psychophysical and optical methods that measure MPOD at a limited number of eccentricities. Consequently, skin RRS and MPVUC at 9° are both reasonable biomarkers of macular carotenoid status that could be readily adapted to research and clinical settings. PMID:28728169

  2. Correlations Between Macular, Skin, and Serum Carotenoids.

    PubMed

    Conrady, Christopher D; Bell, James P; Besch, Brian M; Gorusupudi, Aruna; Farnsworth, Kelliann; Ermakov, Igor; Sharifzadeh, Mohsen; Ermakova, Maia; Gellermann, Werner; Bernstein, Paul S

    2017-07-01

    Ocular and systemic measurement and imaging of the macular carotenoids lutein and zeaxanthin have been employed extensively as potential biomarkers of AMD risk. In this study, we systematically compare dual wavelength retinal autofluorescence imaging (AFI) of macular pigment with skin resonance Raman spectroscopy (RRS) and serum carotenoid levels in a clinic-based population. Eighty-eight patients were recruited from retina and general ophthalmology practices from a tertiary referral center and excluded only if they did not have all three modalities tested, had a diagnosis of macular telangiectasia (MacTel) or Stargardt disease, or had poor AFI image quality. Skin, macular, and serum carotenoid levels were measured by RRS, AFI, and HPLC, respectively. Skin RRS measurements and serum zeaxanthin concentrations correlated most strongly with AFI macular pigment volume under the curve (MPVUC) measurements up to 9° eccentricity relative to MPVUC or rotationally averaged macular pigment optical density (MPOD) measurements at smaller eccentricities. These measurements were reproducible and not significantly affected by cataracts. We also found that these techniques could readily identify subjects taking oral carotenoid-containing supplements. Larger macular pigment volume AFI and skin RRS measurements are noninvasive, objective, and reliable methods to assess ocular and systemic carotenoid levels. They are an attractive alternative to psychophysical and optical methods that measure MPOD at a limited number of eccentricities. Consequently, skin RRS and MPVUC at 9° are both reasonable biomarkers of macular carotenoid status that could be readily adapted to research and clinical settings.

  3. Human ocular carotenoid-binding proteins†

    PubMed Central

    Li, Binxing; Vachali, Preejith

    2014-01-01

    Two dietary carotenoids, lutein and zeaxanthin, are specifically delivered to the human macula at the highest concentration anywhere in the body. Whenever a tissue exhibits highly selective uptake of a compound, it is likely that one or more specific binding proteins are involved in the process. Over the past decade, our laboratory has identified and characterized several carotenoid-binding proteins from human retina including a pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein, a member of the steroidogenic acute regulatory domain (StARD) family as a lutein-binding protein, and tubulin as a less specific, but higher capacity site for carotenoid deposition. In this article, we review the purification and characterization of these carotenoid-binding proteins, and we relate these ocular carotenoid-binding proteins to the transport and uptake role of serum lipoproteins and scavenger receptor proteins in a proposed pathway for macular pigment carotenoid delivery to the human retina. PMID:20820671

  4. [Investigation needs on carotenoids in Latin America].

    PubMed

    Muñoz de Chávez, M; Chávez, A; Calvo, C

    1999-09-01

    Many recent papers show the important role of bioactive phytochemicals to maintain a good health status. Among them the carotenoids are the best known. About 637 have been described and possibly 70 of them could have an important role in human health, 16 have been found in human brain in high amounts. Most of the studies have found relations between the carotenoids and chronic non-communicable diseases like several types of cancer, atherogenic disease and some degenerative pathology of the eye. This relation is mediated by genes and age. Studies of carotenoids are of scientific and economic interest for Latin America as many tropical products are high sources of these compounds. Therefore the first task is to analyze them and iniciate some evaluation on its metabolic availability. A coordinated regional work is proposed, in which 40 or 50 fruits and vegetables are analyzed in terms of the seven carotenoids most related to human health. At the same time it will be important to start epidemiological studies that will compare groups with different levels of consumption of fruits and vegetables and make chronic disease risk analysis. In some countries of the Latin American region, with the support of FAO and INFOODS, some courses and meetings are taking place so that in a short time period the carotenoid composition of the important regional foods will be completed and a carotenoid regional food composition table be published.

  5. Metabolic engineering towards biotechnological production of carotenoids in microorganisms.

    PubMed

    Lee, P C; Schmidt-Dannert, C

    2002-10-01

    Carotenoids are important natural pigments produced by many microorganisms and plants. Traditionally, carotenoids have been used in the feed, food and nutraceutical industries. The recent discoveries of health-related beneficial properties attributed to carotenoids have spurred great interest in the production of structurally diverse carotenoids for pharmaceutical applications. The availability of a considerable number of microbial and plant carotenoid genes that can be functionally expressed in heterologous hosts has opened ways for the production of diverse carotenoid compounds in heterologous systems. In this review, we will describe the recent progress made in metabolic engineering of non-carotenogenic microorganisms for improved carotenoid productivity. In addition, we will discuss the application of combinatorial and evolutionary strategies to carotenoid pathway engineering to broaden the diversity of carotenoid structures synthesized in recombinant hosts.

  6. Carotenoid-oxygenases: Key Players for Carotenoid Function and Homeostasis in Mammalian Biology

    PubMed Central

    Lobo, Glenn P.; Amengual, Jaume; Palczewski, Grzegorz; Babino, Darwin; von Lintig, Johannes

    2011-01-01

    Humans depend on a dietary intake of lipids to maintain optimal health. Among various classes of dietary lipids, the physiological importance of carotenoids is still controversially discussed. On one hand, it is well established that carotenoids such as β,β-carotene are a major source for vitamin A that plays critical roles for vision and many aspects of cell physiology. On the other hand, large clinical trials have failed to show clear health benefits of carotenoids supplementation and even suggest adverse health effects in individuals at risk of disease. In recent years, key molecular players for carotenoid metabolism have been identified, including an evolutionarily well conserved family of carotenoid-oxygenases. Studies in knockout mouse models for these enzymes revealed that carotenoid metabolism is a highly regulated process and that this regulation already takes place at the level of intestinal absorption. These studies also provided evidence that of β,β-carotene conversion can influence retinoid-dependent processes in the mouse embryo and in adult tissues. Moreover, these analyses provide an explanation for adverse health effects of carotenoids by showing that a pathological accumulation of these compounds can induce oxidative stress in mitochondria and cell signaling pathways related to disease. Advancing knowledge about carotenoid metabolism will contribute to a better understanding of the biochemical and physiological roles of these important micronutrients in health and disease. PMID:21569862

  7. Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies

    USDA-ARS?s Scientific Manuscript database

    Resonance Raman Spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status, as assessed by RRS, has been suggested as a promising biomarker for use in human studies. This manuscript describes...

  8. A subfemtotesla multichannel atomic magnetometer

    NASA Astrophysics Data System (ADS)

    Kominis, I. K.; Kornack, T. W.; Allred, J. C.; Romalis, M. V.

    2003-04-01

    The magnetic field is one of the most fundamental and ubiquitous physical observables, carrying information about all electromagnetic phenomena. For the past 30 years, superconducting quantum interference devices (SQUIDs) operating at 4K have been unchallenged as ultrahigh-sensitivity magnetic field detectors, with a sensitivity reaching down to 1fTHz-1/2 (1fT = 10-15T). They have enabled, for example, mapping of the magnetic fields produced by the brain, and localization of the underlying electrical activity (magnetoencephalography). Atomic magnetometers, based on detection of Larmor spin precession of optically pumped atoms, have approached similar levels of sensitivity using large measurement volumes, but have much lower sensitivity in the more compact designs required for magnetic imaging applications. Higher sensitivity and spatial resolution combined with non-cryogenic operation of atomic magnetometers would enable new applications, including the possibility of mapping non-invasively the cortical modules in the brain. Here we describe a new spin-exchange relaxation-free (SERF) atomic magnetometer, and demonstrate magnetic field sensitivity of 0.54fTHz-1/2 with a measurement volume of only 0.3cm3. Theoretical analysis shows that fundamental sensitivity limits of this device are below 0.01fTHz-1/2. We also demonstrate simple multichannel operation of the magnetometer, and localization of magnetic field sources with a resolution of 2mm.

  9. Multichannel and Multidimensional Bargmann Potentials

    NASA Astrophysics Data System (ADS)

    Plekhanvov, E. B.; Suzko, A. S.; Zakhariev, B. N.

    The class of potential matrices for which coupled channel Schrödinger equations have exact solutions is presented. This is achieved due to degeneration of the kernel of the inverse-problem integral equation with respect to the channel indices, in addition to separability of its coordinate dependence. No attention has been paid before to this fact. Maybe therefore there was no satisfactory multichannel generalization of Bargmann potentials.Partially nonlocal Bargmann potentials for multidimensional and many-particle systems are constructed. Examples of new transparent potentials are given.Translated AbstractMehrkanal und multidimensionale Bargmann-PotentialePotentialmatrizen, für die die Mehrkanal-Schrödingergleichung exakt lösbar ist, werden angegeben. Die entsprechenden Schrödingergleichungen sind exakt lösbar dank der Entartung des Kerns der Integralgleichung des inversen Streuproblems hinsichtlich sowohl der Koordinatenabhängigkeit als auch der Kanalindizes. Dieser Sachverhalt war bisher nicht bemerkt worden. Es werden teilweise nichtlokale Potentiale für mehrdimensionale und Vielteilchen-Systeme konstruiert. Neue Beispiele von nichtreflektierden Potentialen werden angegeben.

  10. Carotenoid-enriched transgenic corn delivers bioavailable carotenoids to poultry and protects them against coccidiosis.

    PubMed

    Nogareda, Carmina; Moreno, Jose A; Angulo, Eduardo; Sandmann, Gerhard; Portero, Manuel; Capell, Teresa; Zhu, Changfu; Christou, Paul

    2016-01-01

    Carotenoids are health-promoting organic molecules that act as antioxidants and essential nutrients. We show that chickens raised on a diet enriched with an engineered corn variety containing very high levels of four key carotenoids (β-carotene, lycopene, zeaxanthin and lutein) are healthy and accumulate more bioavailable carotenoids in peripheral tissues, muscle, skin and fat, and more retinol in the liver, than birds fed on standard corn diets (including commercial corn supplemented with colour additives). Birds were challenged with the protozoan parasite Eimeria tenella and those on the high-carotenoid diet grew normally, suffered only mild disease symptoms (diarrhoea, footpad dermatitis and digital ulcers) and had lower faecal oocyst counts than birds on the control diet. Our results demonstrate that carotenoid-rich corn maintains poultry health and increases the nutritional value of poultry products without the use of feed additives.

  11. Patterns of Default Mode Network Deactivation in Obsessive Compulsive Disorder

    PubMed Central

    Gonçalves, Óscar F.; Soares, José Miguel; Carvalho, Sandra; Leite, Jorge; Ganho-Ávila, Ana; Fernandes-Gonçalves, Ana; Pocinho, Fernando; Carracedo, Angel; Sampaio, Adriana

    2017-01-01

    The objective of the present study was to research the patterns of Default Mode Network (DMN) deactivation in Obsessive Compulsive Disorder (OCD) in the transition between a resting and a non-rest emotional condition. Twenty-seven participants, 15 diagnosed with OCD and 12 healthy controls (HC), underwent a functional neuroimaging paradigm in which DMN brain activation in a resting condition was contrasted with activity during a non-rest condition consisting in the presentation of emotionally pleasant and unpleasant images. Results showed that HC, when compared with OCD, had a significant deactivation in two anterior nodes of the DMN (medial frontal and superior frontal) in the non-rest pleasant stimuli condition. Additional analysis for the whole brain, contrasting the resting condition with all the non-rest conditions grouped together, showed that, compared with OCD, HC had a significantly deactivation of a widespread brain network (superior frontal, insula, middle and superior temporal, putamen, lingual, cuneus, and cerebellum). Concluding, the present study found that OCD patients had difficulties with the deactivation of DMN even when the non-rest condition includes the presentation of emotional provoking stimuli, particularly evident for images with pleasant content. PMID:28287615

  12. A Summary of Published Mode Deactivation Therapy Articles

    ERIC Educational Resources Information Center

    Apsche, Jack A.

    2006-01-01

    This article summarizes all of the Mode Deactivation Therapy, (MDT) articles published to date. MDT has shown to be more effective than Cognitive Behavior Therapy, (CBT), Social Skills Training, (SST), and Dialectical Behavior Therapy, (DBT), Apsche, Bass, Jennings, Murphy, Hunter, and Siv, (2005); Apsche & Bass, (2005); Apsche, Bass & Murphy,…

  13. 200 Area Deactivation Project Facilities Authorization Envelope Document

    SciTech Connect

    DODD, E.N.

    2000-03-28

    Project facilities as required by HNF-PRO-2701, Authorization Envelope and Authorization Agreement. The Authorization Agreements (AA's) do not identify the specific set of environmental safety and health requirements that are applicable to the facility. Therefore, the facility Authorization Envelopes are defined here to identify the applicable requirements. This document identifies the authorization envelopes for the 200 Area Deactivation.

  14. Compassionate deactivation of ventricular assist devices in pediatric patients.

    PubMed

    Hollander, Seth A; Axelrod, David M; Bernstein, Daniel; Cohen, Harvey J; Sourkes, Barbara; Reddy, Sushma; Magnus, David; Rosenthal, David N; Kaufman, Beth D

    2016-05-01

    Despite greatly improved survival in pediatric patients with end-stage heart failure through the use of ventricular assist devices (VADs), heart failure ultimately remains a life-threatening disease with a significant symptom burden. With increased demand for donor organs, liberalizing the boundaries of case complexity, and the introduction of destination therapy in children, more children can be expected to die while on mechanical support. Despite this trend, guidelines on the ethical and pragmatic issues of compassionate deactivation of VAD support in children are strikingly absent. As VAD support for pediatric patients increases in frequency, the pediatric heart failure and palliative care communities must work toward establishing guidelines to clarify the complex issues surrounding compassionate deactivation. Patient, family and clinician attitudes must be ascertained and education regarding the psychological, legal and ethical issues should be provided. Furthermore, pediatric-specific planning documents for use before VAD implantation as well as deactivation checklists should be developed to assist with decision-making at critical points during the illness trajectory. Herein we review the relevant literature regarding compassionate deactivation with a specific focus on issues related to children.

  15. A Comprehensive Literature Review of Mode Deactivation Therapy

    ERIC Educational Resources Information Center

    Houston, Marsha Ann; Apsche, Jack A.; Bass, Christopher K.

    2007-01-01

    In this article literature published on Mode Deactivation Therapy (MDT) was reviewed in depth. Several studies were identified that used a common outcome measure of reduction of physical and sexual aggression, other risk related behaviors. Comparisons of MDT and, other standardized approaches typically used in treating aggression in juveniles,…

  16. Mode Deactivation Therapy (MDT) Family Therapy: A Theoretical Case Analysis

    ERIC Educational Resources Information Center

    Apsche, J. A.; Ward Bailey, S. R.

    2004-01-01

    This case study presents a theoretical analysis of implementing mode deactivation therapy (MDT) (Apsche & Ward Bailey, 2003) family therapy with a 13 year old Caucasian male. MDT is a form of cognitive behavioral therapy (CBT) that combines the balance of dialectical behavior therapy (DBT) (Linehan, 1993), the importance of perception from…

  17. A Literature Review and Analysis of Mode Deactivation Therapy

    ERIC Educational Resources Information Center

    Apsche, Jack A.

    2010-01-01

    This article is a review of articles, chapters and current research examining Mode Deactivation Therapy. Current applications of MDT suggest that mindfulness is a core component of MDT, as well as acceptance, defusion and validation, clarification and redirection of the functional alternative beliefs. These components are the core of MDT and a…

  18. PCG-STES, Rominger de-activates middeck experiment

    NASA Image and Video Library

    1997-08-27

    STS085-324-007 (7 - 19 August 1997) --- Astronaut Kent V. Rominger, pilot, uses a tool to deactivate the Protein Crystal Growth (PCG) experiment on the mid-deck of the Space Shuttle Discovery near the end of the 12-day STS-85 flight.

  19. Remote System Technologies for Deactivating Hanford Hot Cells (for WM'03 - abstract included)

    SciTech Connect

    BERLIN, G.T.

    2003-01-28

    Remote system technologies are being deployed by Fluor Hanford to help accelerate the deactivation of highly-radioactive hot cell facilities. This paper highlights the application of several remotely deployed technologies enabling the deactivation tasks.

  20. Carotenoid-to-bacteriochlorophyll energy transfer through vibronic coupling in LH2 from Phaeosprillum molischianum.

    PubMed

    Thyrhaug, Erling; Lincoln, Craig N; Branchi, Federico; Cerullo, Giulio; Perlík, Václav; Šanda, František; Lokstein, Heiko; Hauer, Jürgen

    2017-05-18

    The peripheral light-harvesting antenna complex (LH2) of purple photosynthetic bacteria is an ideal testing ground for models of structure-function relationships due to its well-determined molecular structure and ultrafast energy deactivation. It has been the target for numerous studies in both theory and ultrafast spectroscopy; nevertheless, certain aspects of the convoluted relaxation network of LH2 lack a satisfactory explanation by conventional theories. For example, the initial carotenoid-to-bacteriochlorophyll energy transfer step necessary on visible light excitation was long considered to follow the Förster mechanism, even though transfer times as short as 40 femtoseconds (fs) have been observed. Such transfer times are hard to accommodate by Förster theory, as the moderate coupling strengths found in LH2 suggest much slower transfer within this framework. In this study, we investigate LH2 from Phaeospirillum (Ph.) molischianum in two types of transient absorption experiments-with narrowband pump and white-light probe resulting in 100 fs time resolution, and with degenerate broadband 10 fs pump and probe pulses. With regard to the split Qx band in this system, we show that vibronically mediated transfer explains both the ultrafast carotenoid-to-B850 transfer, and the almost complete lack of transfer to B800. These results are beyond Förster theory, which predicts an almost equal partition between the two channels.

  1. Multichannel DBS halftoning for improved texture quality

    NASA Astrophysics Data System (ADS)

    Slavuj, Radovan; Pedersen, Marius

    2015-01-01

    The paper aims to develop a method for multichannel halftoning based on the Direct Binary Search (DBS) algorithm. We integrate specifics and benefits of multichannel printing into the halftoning method in order to further improve texture quality of DBS and to create halftoning that would suit for multichannel printing. Originally, multichannel printing is developed for an extended color gamut, at the same time additional channels can help to improve individual and combined texture of color halftoning. It does so in a similar manner to the introduction of the light colors (diluted inks) in printing. Namely, if one observes Red, Green and Blue inks as the light version of the M+Y, C+Y, C+M combinations, the visibility of the unwanted halftoning textures can be reduced. Analogy can be extent to any number of ink combinations, or Neugebauer Primaries (NPs) as the alternative building blocks. The extended variability of printing spatially distributed NPs could provide many practical solution and improvements in color accuracy, image quality, and could enable spectral printing. This could be done by selection of NPs per dot area location based on the constraint of the desired reproduction. Replacement with brighter NP at the location could induce a color difference where a tradeoff between image quality and color accuracy is created. With multichannel enabled DBS haftoning, we are able to reduce visibility of the textures, to provide better rendering of transitions, especially in mid and dark tones.

  2. Carotenoids in DPPC vesicles: membrane dynamics

    NASA Astrophysics Data System (ADS)

    Socaciu, Carmen; Lausch, Carsten; Diehl, Horst A.

    1999-09-01

    Incorporation of carotenoids into membranes is supposed to change their physical properties with consequences to signal transduction and membrane protein activities. Here the physical parameters membrane fluidity, micropolarity and anisotropy are considered and measured in multilamellar and unilamellar vesicles of dipalmitoylphosphatidyicholine (DPPC) after incorporation of 1, 2.5 and 5 mol% β-carotene, lutein, zeaxanthin, canthaxanthin, or astaxhanthin using 4 mol% pyrene or 1 μM 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescent labels. Contrary to other investigations, no significant change in membrane fluidity (as evaluated by the pyrene excimer method) can be found. But a change of micropolarity in the pyrene label environment is obtained from the pyrene monomer fluorescence emission fine structure after incorporation of carotenoids. The membrane anisotropy is enhanced significantly only by those carotenoids which incorporate worst into the membrane. This leads to the hypothesis that carotenoid incorporation into membranes is governed not only by carotenoid polarity hut also by their ability to change membrane anisotropy.

  3. Diversifying Carotenoid Biosynthetic Pathways by Directed Evolution

    PubMed Central

    Umeno, Daisuke; Tobias, Alexander V.; Arnold, Frances H.

    2005-01-01

    Microorganisms and plants synthesize a diverse array of natural products, many of which have proven indispensable to human health and well-being. Although many thousands of these have been characterized, the space of possible natural products—those that could be made biosynthetically—remains largely unexplored. For decades, this space has largely been the domain of chemists, who have synthesized scores of natural product analogs and have found many with improved or novel functions. New natural products have also been made in recombinant organisms, via engineered biosynthetic pathways. Recently, methods inspired by natural evolution have begun to be applied to the search for new natural products. These methods force pathways to evolve in convenient laboratory organisms, where the products of new pathways can be identified and characterized in high-throughput screening programs. Carotenoid biosynthetic pathways have served as a convenient experimental system with which to demonstrate these ideas. Researchers have mixed, matched, and mutated carotenoid biosynthetic enzymes and screened libraries of these “evolved” pathways for the emergence of new carotenoid products. This has led to dozens of new pathway products not previously known to be made by the assembled enzymes. These new products include whole families of carotenoids built from backbones not found in nature. This review details the strategies and specific methods that have been employed to generate new carotenoid biosynthetic pathways in the laboratory. The potential application of laboratory evolution to other biosynthetic pathways is also discussed. PMID:15755953

  4. Functions of Carotenoid Metabolites and Breakdown Products

    NASA Astrophysics Data System (ADS)

    Britton, George

    It is not only intact carotenoids but also fragments of carotenoid molecules that have important natural functions and actions. The electron-rich polyene chain of the carotenoids is very susceptible to oxidative breakdown, which may be enzymic or non-enzymic. Central cleavage gives C20 compounds, retinoids, as described in Chapter 16. Cleavage at other positions gives smaller fragments, notably C10, C13 and C15 compounds that retain the carotenoid end group. The formation of these is described in Chapter 17 and in Volume 3, Chapter 4. Oxidative breakdown can also take place during storage, processing and curing of plant material, and the products contribute to the desired aroma/flavour properties of, for example, tea, wine and tobacco. The importance of vitamin A (C20) in animals is well known. Vitamin A deficiency is still a major concern in many parts of the world. It can lead to blindness and serious ill-health or death, especially in young children. Volatile smaller carotenoid fragments (`norisoprenoids') are widespread scent/flavour compounds in plants.

  5. Absorbance changes of carotenoids in different solvents.

    PubMed

    Zang, L Y; Sommerburg, O; van Kuijk, F J

    1997-01-01

    Carotenoids are typically measured in tissues with the high performance liquid chromatography (HPLC) and quantitation is usually done by calibrating with stock solutions in solvents. Four carotenoids including lutein, zeaxanthin, lycopene and beta-carotene were dissolved in hexane and methanol respectively, and their absorbance characteristics were compared. Lutein shows absorbance spectra that are almost independent of solvents at various concentrations. Spectra of zeaxanthin, lycopene and beta-carotene were found to be more solvent-dependent. The absorbance of zeaxanthin at lambda max is about approximately 2 times larger in methanol than in hexane at the higher concentrations, and increased non-linearly with increasing concentration in hexane. The absorbance of lycopene at lambda max in hexane is approximately 4 fold larger than in methanol, but the absorbance of the methanol sample can be recovered by re-extracting this sample in hexane. The absorbance of beta-carotene in hexane is larger than in methanol, and increased linearly with increasing concentration. But beta-carotene showed a non-linear concentration effect in methanol. There are very small variations in lambda max for all four carotenoids between hexane and methanol, due to differences in molar extinction coefficients. The non-linear concentration effects for these carotenoids are probably due to differences in solubility leading to the formation of microcrystals. Thus, care should be taken with quantitation of tissue carotenoid values, when they depend on measurement of concentrations in stock solutions.

  6. Bioactivity of Carotenoids - Chasms of Knowledge.

    PubMed

    Bohn, Torsten

    2017-02-10

    Carotenoid dietary intake, especially within fruits/vegetables and their plasma levels have been associated in many epidemiological studies with a reduced risk of several chronic diseases, including type-2 diabetes, cardiovascular diseases, several types of cancer, and agerelated macular degeneration. However, intervention trials with isolated carotenoids (as supplements) have fallen short of fulfi lling the hopes that were placed in these lipophilic pigments, often producing no positive or even adverse effects, such as increased lung cancer rate or total mortality. More recent studies have suggested that certain metabolites, and not necessarily the native compounds may be (the most) biologically active ones, such as certain apocarotenals (originating following enzymatic cleavage) and other more polar compounds, acting as more suitable electrophiles to react with transcription factors such as nuclear factor kappa-B (NF-KB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In addition, it appears that questions of dosing are likewise crucial, as may be interactions of non-provitamin A carotenoids and their derivatives with retinoic acid receptors (RAR) or retinoid X receptors (RXR). Furthermore, our picture on carotenoid metabolism may be incomplete, as our knowledge on e. g. the interaction with the microbiota is virtually nil. In this position article, it is aimed to highlight some of the discrepancies that appear to trouble carotenoid-related research, and point out some of the existing gaps in our knowledge.

  7. Carotenoids: potential allies of cardiovascular health?

    PubMed Central

    Gammone, Maria Alessandra; Riccioni, Graziano; D'Orazio, Nicolantonio

    2015-01-01

    Carotenoids are a class of natural, fat-soluble pigments found principally in plants. They have potential antioxidant biological properties because of their chemical structure and interaction with biological membranes. Epidemiologic studies supported the hypothesis that antioxidants could be used as an inexpensive means of both primary and secondary cardiovascular disease (CVD) prevention. In fact, the oxidation of low-density lipoproteins (LDL) in the vessels plays a key role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by high dietary antioxidant intake, so that carotenoids, as part of food patterns such as the Mediterranean diet, may have beneficial effects on cardiovascular health too. Further properties of carotenoids leading to a potential reduction of cardiovascular risk are represented by lowering of blood pressure, reduction of pro-inflammatory cytokines and markers of inflammation (such as C-reactive protein), and improvement of insulin sensitivity in muscle, liver, and adipose tissues. In addition, recent nutrigenomics studies have focused on the exceptional ability of carotenoids in modulating the expression of specific genes involved in cell metabolism. The aim of this review is to focus attention to this effect of some carotenoids to prevent CVD. PMID:25660385

  8. Metabolism of carotenoid pigments in birds.

    PubMed

    Brush, A H

    1990-09-01

    Carotenoid pigments are an important component in the plumage of birds. The metabolic precursors are dietary in origin but many species have the capacity to chemically modify and selectively deposit the pigments. The ensuing plumage patterns are important in communication and identification. The bright yellows, oranges, and reds are due mostly to xanthophylls; keto and hydroxy carotenes. Some are deposited unmodified (e.g., lutein) whereas others are modified chemically (canthaxanthin, astaxanthin). Early workers concentrated on demonstrating that feather carotenoids were derived from the diet and deposited selectively. Progress in defining and solving biological problems depended on advances in chemical and analytical techniques. Subsequent investigation showed that various plumage colormorphs, seasonal plumage changes or colors in common mutant, were due to relatively simple chemical changes in carotenoids but had profound biological consequences. Equally important was the realization that many of these processes were under genetic control. Validation came from feeding studies of flamingos and finches. Recent studies have employed the plumage carotenoids to test hypotheses of genetic divergence, to relate plumage color to environmental process, and to demonstrate the influence of synthetic changes on color. Understanding the processes has advanced with the introduction of high-resolution separation techniques and the ability to determine both conformation and absolute configuration. The next steps will be in the direction of understanding the enzymatic modification, transport, and tissue selectivity of feather carotenoids.

  9. Iridophores and not carotenoids account for chromatic variation of carotenoid-based coloration in common lizards (Lacerta vivipara).

    PubMed

    San-Jose, Luis M; Granado-Lorencio, Fernando; Sinervo, Barry; Fitze, Patrick S

    2013-03-01

    Abstract Carotenoids typically need reflective background components to shine. Such components, iridophores, leucophores, and keratin- and collagen-derived structures, are generally assumed to show no or little environmental variability. Here, we investigate the origin of environmentally induced variation in the carotenoid-based ventral coloration of male common lizards (Lacerta vivipara) by investigating the effects of dietary carotenoids and corticosterone on both carotenoid- and background-related reflectance. We observed a general negative chromatic change that was prevented by β-carotene supplementation. However, chromatic changes did not result from changes in carotenoid-related reflectance or skin carotenoid content but from changes in background-related reflectance that may have been mediated by vitamin A1. An in vitro experiment showed that the encountered chromatic changes most likely resulted from changes in iridophore reflectance. Our findings demonstrate that chromatic variation in carotenoid-based ornaments may not exclusively reflect differences in integumentary carotenoid content and, hence, in qualities linked to carotenoid deposition (e.g., foraging ability, immune response, or antioxidant capacity). Moreover, skin carotenoid content and carotenoid-related reflectance were related to male color polymorphism, suggesting that carotenoid-based coloration of male common lizards is a multicomponent signal, with iridophores reflecting environmental conditions and carotenoids reflecting genetically based color morphs.

  10. Dark excited States of carotenoid regulated by bacteriochlorophyll in photosynthetic light harvesting.

    PubMed

    Nakamura, Ryosuke; Nakagawa, Katsunori; Nango, Mamoru; Hashimoto, Hideki; Yoshizawa, Masayuki

    2011-03-31

    In photosynthesis, carotenoids play important roles in light harvesting (LH) and photoprotective functions, which have been described mainly in terms of two singlet excited states of carotenoids: S(1) and S(2). In addition to the "dark" S(1) state, another dark state, S*, was recently identified and its involvement in photosynthetic functions was determined. However, there is no consistent picture concerning its nature or the mechanism of its formation. One particularly anomalous behavior obtained from femtosecond transient absorption (TA) spectroscopy is that the S*/S(1) population ratio depends on the excitation intensity. Here, we focus on the effect of nearby bacteriochlorophyll (BChl) on the relaxation dynamics of carotenoid in the LH complex. We performed femtosecond TA spectroscopy combined with pre-excitation of BChl in the reconstituted LH1 complex from Rhodospirillum rubrum S1. We observed that the energy flow from S(1), including its vibrationally excited hot states, to S* occurs only when nearby BChl is excited into Q(y), resulting in an increase in S*/S(1). We also examined the excitation-intensity dependence of S*/S(1) by conventional TA spectroscopy. A comparison between the pre-excitation effect and excitation-intensity dependence shows a strong correlation of S*/S(1) with the number of BChls excited into Q(y). In addition, we observed an increase in triplet formation as the S* population increased, indicating that S* is an electronic excited state that is the precursor to triplet formation. Our findings provide an explanation for observed spectroscopic features, including the excitation-intensity dependences debated so far, and offer new insights into energy deactivation mechanisms inherent in the LH antenna.

  11. Carotenoid profiling and the expression of carotenoid biosynthetic genes in developing coffee grain.

    PubMed

    Simkin, Andrew J; Kuntz, Marcel; Moreau, Helene; McCarthy, James

    2010-06-01

    Roasted coffee contains a complex array of volatile organic compounds (VOCs) which make an important contribution to the characteristic flavour and aroma of the final beverage. It is thought that a few of the potent coffee aroma components, such as "beta-damascenone", could be derived from carotenoid precursors. In order to further investigate the potential link between carotenoids and coffee aroma profiles, we have measured the carotenoid content in developing coffee grain. The data obtained confirms the presence of lutein in the grain, and additionally shows that the immature coffee grain also contains significant amounts of beta-carotene, alpha-carotene, violaxanthin, and neoxanthin. Complimentary quantitative gene expression analysis revealed that all the carotenoid biosynthetic genes examined are expressed in the grain, and that the transcript levels are gene and stage dependent. Furthermore, consistent with the reduction of the carotenoid levels at the last stage of grain development (mature-red), most of the transcript levels were also found to be lower at the final developmental stage. Quantitative expression analysis of the carotenoid genes was also carried out for the developing pericarp tissue of the coffee cherries. Again, all the genes examined were expressed, and in most cases, the highest transcript levels were detected around the large green-yellow stages, a period when carotenoid synthesis is probably greatest.

  12. Subchromoplast sequestration of carotenoids affects regulatory mechanisms in tomato lines expressing different carotenoid gene combinations.

    PubMed

    Nogueira, Marilise; Mora, Leticia; Enfissi, Eugenia M A; Bramley, Peter M; Fraser, Paul D

    2013-11-01

    Metabolic engineering of the carotenoid pathway in recent years has successfully enhanced the carotenoid contents of crop plants. It is now clear that only increasing biosynthesis is restrictive, as mechanisms to sequestrate these increased levels in the cell or organelle should be exploited. In this study, biosynthetic pathway genes were overexpressed in tomato (Solanum lycopersicum) lines and the effects on carotenoid formation and sequestration revealed. The bacterial Crt carotenogenic genes, independently or in combination, and their zygosity affect the production of carotenoids. Transcription of the pathway genes was perturbed, whereby the tissue specificity of transcripts was altered. Changes in the steady state levels of metabolites in unrelated sectors of metabolism were found. Of particular interest was a concurrent increase of the plastid-localized lipid monogalactodiacylglycerol with carotenoids along with membranous subcellular structures. The carotenoids, proteins, and lipids in the subchromoplast fractions of the transgenic tomato fruit with increased carotenoid content suggest that cellular structures can adapt to facilitate the sequestration of the newly formed products. Moreover, phytoene, the precursor of the pathway, was identified in the plastoglobule, whereas the biosynthetic enzymes were in the membranes. The implications of these findings with respect to novel pathway regulation mechanisms are discussed.

  13. Assembly of photoactive orange carotenoid protein from its domains unravels a carotenoid shuttle mechanism.

    PubMed

    Moldenhauer, Marcus; Sluchanko, Nikolai N; Buhrke, David; Zlenko, Dmitry V; Tavraz, Neslihan N; Schmitt, Franz-Josef; Hildebrandt, Peter; Maksimov, Eugene G; Friedrich, Thomas

    2017-09-01

    The photoswitchable orange carotenoid protein (OCP) is indispensable for cyanobacterial photoprotection by quenching phycobilisome fluorescence upon photoconversion from the orange OCP(O) to the red OCP(R) form. Cyanobacterial genomes frequently harbor, besides genes for orange carotenoid proteins (OCPs), several genes encoding homologs of OCP's N- or C-terminal domains (NTD, CTD). Unlike the well-studied NTD homologs, called Red Carotenoid Proteins (RCPs), the role of CTD homologs remains elusive. We show how OCP can be reassembled from its functional domains. Expression of Synechocystis OCP-CTD in carotenoid-producing Escherichia coli yielded violet-colored proteins, which, upon mixing with the RCP-apoprotein, produced an orange-like photoswitchable form that further photoconverted into a species that quenches phycobilisome fluorescence and is spectroscopically indistinguishable from RCP, thus demonstrating a unique carotenoid shuttle mechanism. Spontaneous carotenoid transfer also occurs between canthaxanthin-coordinating OCP-CTD and the OCP apoprotein resulting in formation of photoactive OCP. The OCP-CTD itself is a novel, dimeric carotenoid-binding protein, which can coordinate canthaxanthin and zeaxanthin, effectively quenches singlet oxygen and interacts with the Fluorescence Recovery Protein. These findings assign physiological roles to the multitude of CTD homologs in cyanobacteria and explain the evolutionary process of OCP formation.

  14. An in vitro digestion method adapted for carotenoids and carotenoid esters: moving forward towards standardization.

    PubMed

    Rodrigues, Daniele Bobrowski; Mariutti, Lilian Regina Barros; Mercadante, Adriana Zerlotti

    2016-12-07

    In vitro digestion methods are a useful approach to predict the bioaccessibility of food components and overcome some limitations or disadvantages associated with in vivo methodologies. Recently, the INFOGEST network published a static method of in vitro digestion with a proposal for assay standardization. The INFOGEST method is not specific for any food component; therefore, we aimed to adapt this method to assess the in vitro bioaccessibility of carotenoids and carotenoid esters in a model fruit (Byrsonima crassifolia). Two additional steps were coupled to the in vitro digestion procedure, centrifugation at 20 000g for the separation of the aqueous phase containing mixed micelles and exhaustive carotenoid extraction with an organic solvent. The effect of electrolytes, enzymes and bile acids on carotenoid micellarization and stability was also tested. The results were compared with those found with a simpler method that has already been used for carotenoid bioaccessibility analysis. These values were in the expected range for free carotenoids (5-29%), monoesters (9-26%) and diesters (4-28%). In general, the in vitro bioaccessibility of carotenoids assessed by the adapted INFOGEST method was significantly higher (p < 0.05) than those assessed by the simplest protocol, with or without the addition of simulated fluids. Although no trend was observed, differences in bioaccessibility values depended on the carotenoid form (free, monoester or diester), isomerization (Z/E) and the in vitro digestion protocol. To the best of our knowledge, it was the first time that a systematic identification of carotenoid esters by HPLC-DAD-MS/MS after in vitro digestion using the INFOGEST protocol was carried out.

  15. Restoration of multichannel microwave radiometric images

    NASA Technical Reports Server (NTRS)

    Chin, R. T.; Yeh, C.-L.; Olson, W. S.

    1985-01-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Its properties and limitations are presented. The effect of noise was investigated and a better understanding of the performance of the algorithm with noisy data has been achieved. The restoration scheme with the selection of appropriate constraints was applied to a practical problem. The 6.6, 10.7, 18, and 21 GHz satellite images obtained by the scanning multichannel microwave radiometer (SMMR), each having different spatial resolution, were restored to a common, high resolution (that of the 37 GHz channels) to demonstrate the effectiveness of the method. Both simulated data and real data were used in this study. The restored multichannel images may be utilized to retrieve rainfall distributions.

  16. Restoration of multichannel microwave radiometric images.

    PubMed

    Chin, R T; Yeh, C L; Olson, W S

    1985-04-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Its properties and limitations are presented. The effect of noise was investigated and a better understanding of the performance of the algorithm with noisy data has been achieved. The restoration scheme with the selection of appropriate constraints was applied to a practical problem. The 6.6, 10.7, 18, and 21 GHz satellite images obtained by the scanning multichannel microwave radiometer (SMMR), each having different spatial resolution, were restored to a common, high resolution (that of the 37 GHz channels) to demonstrate the effectiveness of the method. Both simulated data and real data were used in this study. The restored multichannel images may be utilized to retrieve rainfall distributions.

  17. Multichannel framework for singular quantum mechanics

    SciTech Connect

    Camblong, Horacio E.; Epele, Luis N.; Fanchiotti, Huner; García Canal, Carlos A.; Ordóñez, Carlos R.

    2014-01-15

    A multichannel S-matrix framework for singular quantum mechanics (SQM) subsumes the renormalization and self-adjoint extension methods and resolves its boundary-condition ambiguities. In addition to the standard channel accessible to a distant (“asymptotic”) observer, one supplementary channel opens up at each coordinate singularity, where local outgoing and ingoing singularity waves coexist. The channels are linked by a fully unitary S-matrix, which governs all possible scenarios, including cases with an apparent nonunitary behavior as viewed from asymptotic distances. -- Highlights: •A multichannel framework is proposed for singular quantum mechanics and analogues. •The framework unifies several established approaches for singular potentials. •Singular points are treated as new scattering channels. •Nonunitary asymptotic behavior is subsumed in a unitary multichannel S-matrix. •Conformal quantum mechanics and the inverse quartic potential are highlighted.

  18. Photodegradation of carotenoids in human subjects

    SciTech Connect

    Roe, D.A.

    1987-04-01

    Photodegradation of vitamins in vitro is responsible for large losses of these nutrients in foods, beverages, and semisynthetic liquid formula diets. In vivo photodegradation of vitamins has been reported for riboflavin in jaundiced infants exposed to blue light and for folate in patients with chronic psoriasis given photochemotherapy. Two recent studies of normal subjects have also shown that photodegradation of carotenoids in plasma occurs with cumulative exposure of the skin to an artificial light source having maximal spectral emission in the UVA range. Females showed a larger effect of the UV light on their plasma carotenoid levels than males. These observations have identified a need for further investigation of the role of sunlight exposure as a determinant of plasma carotenoid levels and vitamin A status in human subjects.

  19. Carotenoid diagenesis in a marine sediment

    NASA Technical Reports Server (NTRS)

    Watts, C. D.; Maxwell, J. R.

    1977-01-01

    The major carotenoids at three levels (3, 40, and 175 m below the sediment-water interface) in a core from a marine sediment (Cariaco Trench, off Venezuela) have been examined. Mass and electronic spectral data have provided evidence for the onset of a progressive reduction of carotenoids in the geological column. The time scale of the process appears to depend on the particular carotenoid. Reduction of up to two double bonds is observed for the diol, zeaxanthin, in the oldest sediment (about 340,000 years old) but no reduction is observed in the younger samples (about 5000 and 56,000 years old). The diketone, canthaxanthin, shows evidence of reduction of up to two double bonds in the 56,000-yr sample and up to five double bonds in the oldest sample. No reduction of beta-carotene was observed in any of the samples.

  20. Carotenoid diagenesis in a marine sediment

    NASA Technical Reports Server (NTRS)

    Watts, C. D.; Maxwell, J. R.

    1977-01-01

    The major carotenoids at three levels (3, 40, and 175 m below the sediment-water interface) in a core from a marine sediment (Cariaco Trench, off Venezuela) have been examined. Mass and electronic spectral data have provided evidence for the onset of a progressive reduction of carotenoids in the geological column. The time scale of the process appears to depend on the particular carotenoid. Reduction of up to two double bonds is observed for the diol, zeaxanthin, in the oldest sediment (about 340,000 years old) but no reduction is observed in the younger samples (about 5000 and 56,000 years old). The diketone, canthaxanthin, shows evidence of reduction of up to two double bonds in the 56,000-yr sample and up to five double bonds in the oldest sample. No reduction of beta-carotene was observed in any of the samples.

  1. Carotenoids: more than just beta-carotene.

    PubMed

    Gellenbeck, K W

    1998-12-01

    Fruits and vegetables of the human diet contain many of the over 600 carotenoid pigments that have been identified in plants. Led by work with beta-carotene, researchers have constantly been learning more about the metabolism of these compounds in the human body. Research work is now expanding beyond beta-carotene in an effort to understand what happens to all the pigments found in the human diet. This discussion briefly looks at research results on the carotenoids found in human serum as well as the effects of supplementation. Recent confusing results from large intervention trials with beta-carotene and lung cancer incidence are emphasized in relation to supplementation doses and beta-carotene source (synthetic vs. natural). The summation of results emphasizes the importance of the broad spectrum of carotenoids in the diet and relates to supplementation products currently being designed for the marketplace.

  2. Dietary carotenoids are associated with cardiovascular disease risk biomarkers mediated by serum carotenoid concentrations.

    PubMed

    Wang, Ying; Chung, Sang-Jin; McCullough, Marjorie L; Song, Won O; Fernandez, Maria Luz; Koo, Sung I; Chun, Ock K

    2014-07-01

    Hyperlipidemia and elevated circulating C-reactive protein (CRP) and total homocysteine (tHcy) concentrations are cardiovascular disease (CVD) risk factors. Previous studies indicated that higher serum carotenoid concentrations were inversely associated with some of these biomarkers. However, whether dietary carotenoid intake is inversely associated with these CVD risk biomarkers is not well known. We assessed the associations between individual dietary carotenoid intake and CVD risk biomarkers and tested whether the serum carotenoid concentrations explain (mediate) or influence the strength of (moderate) the associations, if any association exists. Dietary data collected from 2 24-h dietary recalls and serum measurements in adult men (n = 1312) and women (n = 1544) from the NHANES 2003-2006 were used. Regression models designed for survey analysis were used to examine the associations between individual dietary carotenoids and log-transformed blood cholesterol, CRP, and tHcy. The corresponding individual serum carotenoid concentration was considered as mediator (and moderator if applicable). After adjustment for covariates, significant inverse associations with LDL cholesterol were observed for dietary β-carotene (P < 0.05) and lutein + zeaxanthin (P < 0.001), and with tHcy for dietary β-carotene (P < 0.05), lycopene (P < 0.05), and total carotenoids (P < 0.05). Dietary lutein + zeaxanthin intake was also positively associated with HDL cholesterol concentrations (P < 0.01). Most of these associations were null after additional adjustment for corresponding serum carotenoid concentrations, indicating the complete mediation effects of serum carotenoids. Serum β-carotene significantly moderated the associations between dietary β-carotene and CRP (P-interaction < 0.05), and quartile 4 of dietary β-carotene was associated with lower CRP concentrations only among participants with serum β-carotene > 0.43 μmol/L. In this population-based cross-sectional study

  3. Optical multichannel sensing of skin blood pulsations

    NASA Astrophysics Data System (ADS)

    Spigulis, Janis; Erts, Renars; Kukulis, Indulis; Ozols, Maris; Prieditis, Karlis

    2004-09-01

    Time resolved detection and analysis of the skin back-scattered optical signals (reflection photoplethysmography or PPG) provide information on skin blood volume pulsations and can serve for cardiovascular assessment. The multi-channel PPG concept has been developed and clinically verified in this study. Portable two- and four-channel PPG monitoring devices have been designed for real-time data acquisition and processing. The multi-channel devices were successfully applied for cardiovascular fitness tests and for early detection of arterial occlusions in extremities. The optically measured heartbeat pulse wave propagation made possible to estimate relative arterial resistances for numerous patients and healthy volunteers.

  4. Restoration of multichannel microwave radiometric images

    NASA Technical Reports Server (NTRS)

    Chin, R. T.; Yeh, C. L.; Olson, W. S.

    1983-01-01

    A constrained iterative image restoration method is applied to multichannel diffraction-limited imagery. This method is based on the Gerchberg-Papoulis algorithm utilizing incomplete information and partial constraints. The procedure is described using the orthogonal projection operators which project onto two prescribed subspaces iteratively. Some of its properties and limitations are also presented. The selection of appropriate constraints was emphasized in a practical application. Multichannel microwave images, each having different spatial resolution, were restored to a common highest resolution to demonstrate the effectiveness of the method. Both noise-free and noisy images were used in this investigation.

  5. Structure and Properties of Carotenoid Cations

    NASA Astrophysics Data System (ADS)

    Liaane-Jensen, Synnove; Lutnees, Bjart Frode

    Naturally occurring carotenoids are familiar as yellow, orange or red pigments with λmax below 600 nm in organic solvents. Carotenoids with short polyene chains, such as the triene phytoene (44) and the pentaene phytofluene (42), absorb light only in the UV region and are colourless. Compounds that absorb light in the near infrared (NIR) region above ca. 900 nm are also colourless, unless they also absorb light in the 600-900 nm region, in which case they appear blue. True carotenoproteins (Chapter 6) are purple-blue and absorb light above 600 nm.

  6. Criticality safety for deactivation of the Rover dry headend process

    SciTech Connect

    Henrikson, D.J.

    1995-12-31

    The Rover dry headend process combusted Rover graphite fuels in preparation for dissolution and solvent extraction for the recovery of {sup 235}U. At the end of the Rover processing campaign, significant quantities of {sup 235}U were left in the dry system. The Rover Dry Headend Process Deactivation Project goal is to remove the remaining uranium bearing material (UBM) from the dry system and then decontaminate the cells. Criticality safety issues associated with the Rover Deactivation Project have been influenced by project design refinement and schedule acceleration initiatives. The uranium ash composition used for calculations must envelope a wide range of material compositions, and yet result in cost effective final packaging and storage. Innovative thinking must be used to provide a timely safety authorization basis while the project design continues to be refined.

  7. The interaction of a metal deactivator with metal surfaces

    SciTech Connect

    Schreifels, J.A. ); Morris, R.E.; Turner, N.H.; Mowery, R.L. )

    1990-01-01

    In modern aircraft fuel systems, the fuel is used as a heat transfer medium to dissipate heat from the avionics and hydraulic systems. Under these conditions, the fuel can undergo autooxidations. Autooxidations of net fuel can result in the formation of insoluble gum and sediment which can impair operation of the jet engine. Metal deactivator additives (MDA) were developed to counteract the catalytic activity of dissolved metals. The authors have directed their efforts at ascertaining the various mechanisms by which MDA can act, particularly in accelerated stability testing. One objective of this study was to determine to what extent interactions with metal surfaces of the test apparent govern the effectiveness of metal deactivators. This paper describes an examination of metal surfaces exposed to MDA solutions to determine under what, if any, conditions metal passivation can occur.

  8. Boosting functionality of synthetic DNA circuits with tailored deactivation

    PubMed Central

    Montagne, Kevin; Gines, Guillaume; Fujii, Teruo; Rondelez, Yannick

    2016-01-01

    Molecular programming takes advantage of synthetic nucleic acid biochemistry to assemble networks of reactions, in vitro, with the double goal of better understanding cellular regulation and providing information-processing capabilities to man-made chemical systems. The function of molecular circuits is deeply related to their topological structure, but dynamical features (rate laws) also play a critical role. Here we introduce a mechanism to tune the nonlinearities associated with individual nodes of a synthetic network. This mechanism is based on programming deactivation laws using dedicated saturable pathways. We demonstrate this approach through the conversion of a single-node homoeostatic network into a bistable and reversible switch. Furthermore, we prove its generality by adding new functions to the library of reported man-made molecular devices: a system with three addressable bits of memory, and the first DNA-encoded excitable circuit. Specific saturable deactivation pathways thus greatly enrich the functional capability of a given circuit topology. PMID:27845324

  9. Boosting functionality of synthetic DNA circuits with tailored deactivation.

    PubMed

    Montagne, Kevin; Gines, Guillaume; Fujii, Teruo; Rondelez, Yannick

    2016-11-15

    Molecular programming takes advantage of synthetic nucleic acid biochemistry to assemble networks of reactions, in vitro, with the double goal of better understanding cellular regulation and providing information-processing capabilities to man-made chemical systems. The function of molecular circuits is deeply related to their topological structure, but dynamical features (rate laws) also play a critical role. Here we introduce a mechanism to tune the nonlinearities associated with individual nodes of a synthetic network. This mechanism is based on programming deactivation laws using dedicated saturable pathways. We demonstrate this approach through the conversion of a single-node homoeostatic network into a bistable and reversible switch. Furthermore, we prove its generality by adding new functions to the library of reported man-made molecular devices: a system with three addressable bits of memory, and the first DNA-encoded excitable circuit. Specific saturable deactivation pathways thus greatly enrich the functional capability of a given circuit topology.

  10. On the puzzling deactivation mechanism of thymine after light irradiation

    SciTech Connect

    Gonzalez, Leticia; Gonzalez-Vazquez, Jesus; Samoylova, Elena; Schultz, Thomas

    2008-12-08

    The possible deactivation mechanisms of thymine after UV light irradiation are reviewed in the light of theoretical calculations. Recent experiments reveal that three transient species with lifetimes in the fs, ps, and ns regime are present in thymine. The possibility of ground or excited state tautomerization is explored and discarded. The role of {pi}{sigma}* states, as well as of the proposed minimum of the {pi}{pi}* excited state surface are assessed. In view of the obtained calculations and results available from the literature, the measured time scales can be tentatively attributed to a model involving different conical intersections between the {pi}{pi}*, n{pi}*, and the electronic ground state, as well as deactivation via the triplet states. Time-resolved photoelectron experiments supported by theoretical calculations are proposed to appraise the validity of this model.

  11. Carotenoids Database: structures, chemical fingerprints and distribution among organisms.

    PubMed

    Yabuzaki, Junko

    2017-01-01

    To promote understanding of how organisms are related via carotenoids, either evolutionarily or symbiotically, or in food chains through natural histories, we built the Carotenoids Database. This provides chemical information on 1117 natural carotenoids with 683 source organisms. For extracting organisms closely related through the biosynthesis of carotenoids, we offer a new similarity search system 'Search similar carotenoids' using our original chemical fingerprint 'Carotenoid DB Chemical Fingerprints'. These Carotenoid DB Chemical Fingerprints describe the chemical substructure and the modification details based upon International Union of Pure and Applied Chemistry (IUPAC) semi-systematic names of the carotenoids. The fingerprints also allow (i) easier prediction of six biological functions of carotenoids: provitamin A, membrane stabilizers, odorous substances, allelochemicals, antiproliferative activity and reverse MDR activity against cancer cells, (ii) easier classification of carotenoid structures, (iii) partial and exact structure searching and (iv) easier extraction of structural isomers and stereoisomers. We believe this to be the first attempt to establish fingerprints using the IUPAC semi-systematic names. For extracting close profiled organisms, we provide a new tool 'Search similar profiled organisms'. Our current statistics show some insights into natural history: carotenoids seem to have been spread largely by bacteria, as they produce C30, C40, C45 and C50 carotenoids, with the widest range of end groups, and they share a small portion of C40 carotenoids with eukaryotes. Archaea share an even smaller portion with eukaryotes. Eukaryotes then have evolved a considerable variety of C40 carotenoids. Considering carotenoids, eukaryotes seem more closely related to bacteria than to archaea aside from 16S rRNA lineage analysis. : http://carotenoiddb.jp.

  12. Environmental Impact Statement: Peacekeeper Missile System Deactivation and Dismantlement

    DTIC Science & Technology

    2000-12-01

    Missouri • Environmental Impact Statement, Minuteman II System Deactivation, Ellsworth AFB , South Dakota 1.7. RELEVANT FEDERAL, STATE, AND LOCAL...dismantlement actions at Minuteman missile facilities at Ellsworth AFB , SD, Whiteman AFB , MO, and Grand Forks AFB , ND also found PCBs in the external...construction stages (i.e., scrap metal recovery, explosive demolition preparation, grading, etc). Dismantlement of the MM II system at Ellsworth AFB

  13. Early deactivation of slower muscle fibres at high movement frequencies.

    PubMed

    Blake, Ollie M; Wakeling, James M

    2014-10-01

    Animals produce rapid movements using fast cyclical muscle contractions. These types of movements are better suited to faster muscle fibres within muscles of mixed fibre types as they can shorten at faster velocities and achieve higher activation-deactivation rates than their slower counterparts. Preferential recruitment of faster muscle fibres has previously been shown during high velocity contractions. Additionally, muscle deactivation takes longer than activation and therefore may pose a limitation to fast cyclical contractions. It has been speculated that slower fibres may be deactivated before faster fibres to accommodate their longer deactivation time. This study aimed to test whether shifts in muscle fibre recruitment occur with derecruitment of slow fibres before faster fibres at high cycle frequencies. Electromyographic (EMG) signals were collected from the medial gastrocnemius at an extreme range of cycle frequencies and workloads. Wavelets were used to resolve the EMG signals into time and frequency space and the primary sources of variability within the EMG frequency spectra were identified through principal component analysis. Early derecruitment of slower fibres was evident at the end of muscle excitation at higher cycle frequencies, as determined by reduced low-frequency EMG content, and additional slower fibre recruitment was present at the highest cycle frequency. The duration of muscle excitation reached a minimum of about 150 ms and did not change for the three highest cycle frequencies, suggesting a duration limit for the medial gastrocnemius. This study provides further evidence of modifications of muscle fibre recruitment strategies to meet the mechanical demands of movement. © 2014. Published by The Company of Biologists Ltd.

  14. Mechanism of acetaldehyde-induced deactivation of microbial lipases.

    PubMed

    Franken, Benjamin; Eggert, Thorsten; Jaeger, Karl E; Pohl, Martina

    2011-02-22

    Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the enzymes. Lyophilization of the enzymes from buffer at pH 6

  15. Mechanism of acetaldehyde-induced deactivation of microbial lipases

    PubMed Central

    2011-01-01

    Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Results Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Conclusions Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the enzymes. Lyophilization of

  16. Gamification of Learning Deactivates the Default Mode Network

    PubMed Central

    Howard-Jones, Paul A.; Jay, Tim; Mason, Alice; Jones, Harvey

    2016-01-01

    We hypothesized that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN) and deactivation of default mode network (DMN) regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer), Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points) and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards). DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated. PMID:26779054

  17. Gamification of Learning Deactivates the Default Mode Network.

    PubMed

    Howard-Jones, Paul A; Jay, Tim; Mason, Alice; Jones, Harvey

    2015-01-01

    We hypothesized that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN) and deactivation of default mode network (DMN) regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer), Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points) and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards). DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated.

  18. Efficacy of myofascial trigger point deactivation for tinnitus control.

    PubMed

    Rocha, Carina Bezerra; Sanchez, Tanit Ganz

    2012-12-01

    Chronic pain in areas surrounding the ear may influence tinnitus. To investigate the efficacy of myofascial trigger point deactivation for the relief of tinnitus. A double-blind randomized clinical trial enrolled 71 patients with tinnitus and myofascial pain syndrome. The experimental group (n = 37) underwent 10 sessions of myofascial trigger point deactivation and the control group (n = 34), 10 sessions with sham deactivation. Treatment of the experimental group was effective for tinnitus relief (p < 0.001). Pain and tinnitus relieves were associated (p = 0.013), so were the ear with worst tinnitus and the side of the body with more pain (p < 0.001). The presence of temporary tinnitus modulation (increase or decrease) upon initial muscle palpation was frequent in both groups, but its temporary decrease was related to the persistent relief at the end of treatment (p = 0.002). Besides medical and audiological investigation, patients with tinnitus should also be checked for: 1) presence of myofascial pain surrounding the ear; 2) laterality between both symptoms; 3) initial decrease of tinnitus during muscle palpation. Treating this specific subgroup of tinnitus patients with myofascial trigger point release may provide better results than others described so far.

  19. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect

    Bartholomew, C.H.

    1990-10-11

    This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for Fischer-Tropsch (FT) synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the thirteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made on the testing of the system hardware and software. H{sub 2} chemisorption capacities and activity selectivity data were also measured for three iron catalysts promoted with 1% alumina. 47 refs., 8 figs., 1 tab.

  20. Resolving Ultrafast Photoinduced Deactivations in Water-solvated Pyrimidine Nucleosides.

    PubMed

    Pepino, Ana J; Segarra-Martí, Javier; Nenov, Artur; Improta, Roberto; Garavelli, Marco

    2017-03-27

    For the first time, ultrafast deactivations of photo-excited water-solvated pyrimidine nucleosides are mapped employing hybrid QM(CASPT2)/MM(AMBER) optimizations that account for explicit solvation, sugar effects and dynamically correlated potential energy surfaces. Low energy S1/S0 ring-puckering and ring-opening conical intersections (CIs) are suggested to drive the ballistic coherent sub-ps (<200fs) decays observed in each pyrimidine, the energetics controlling this processes correlating with the lifetimes observed. A second bright 1π2π* state, promoting excited-state population branching and leading towards a third CI with the ground state, is proposed to be involved in the slower ultrafast decay component observed in Thd/Cyd. The transient spectroscopic signals of the competitive deactivation channels are computed for the first time. A general unified scheme for ultrafast deactivations, spanning the sub-to-few ps time domain, is eventually delivered, with computed data that matches the experiments and elucidates the intrinsic photo-protection mechanism in solvated pyrimidine nucleosides.

  1. Lignocellulosic hydrolysate inhibitors selectively inhibit/deactivate cellulase performance.

    PubMed

    Mhlongo, Sizwe I; den Haan, Riaan; Viljoen-Bloom, Marinda; van Zyl, Willem H

    2015-12-01

    In this study, we monitored the inhibition and deactivation effects of various compounds associated with lignocellulosic hydrolysates on individual and combinations of cellulases. Tannic acid representing polymeric lignin residues strongly inhibited cellobiohydrolase 1 (CBH1) and β-glucosidase 1 (BGL1), but had a moderate inhibitory effect on endoglucanase 2 (EG2). Individual monomeric lignin residues had little or no inhibitory effect on hydrolytic enzymes. However, coniferyl aldehyde and syringaldehyde substantially decreased the activity of CBH1 and deactivated BGL1. Acetic and formic acids also showed strong inhibition of BGL1 but not CBH1 and EG2, whereas tannic, acetic and formic acid strongly inhibited a combination of CBH1 and EG2 during Avicel hydrolysis. Diminishing enzymatic hydrolysis is largely a function of inhibitor concentration and the enzyme-inhibitor relationship, rather than contact time during the hydrolysis process (i.e. deactivation). This suggests that decreased rates of hydrolysis during the enzymatic depolymerisation of lignocellulosic hydrolysates may be imparted by other factors related to substrate crystallinity and accessibility.

  2. Deactivation of a silica-alumina catalyst by coke deposition

    SciTech Connect

    Garcia-Ochoa, F.; Santos, A. . Dept. de Ingenieria Quimica)

    1993-11-01

    Deactivation by fouling of a silica-alumina catalyst when it is used for cyclohexanol dehydration has been studied in a fixed bed laboratory reactor between 548 and 573 K. A kinetic model of the main reaction has been determined, corresponding to a mechanism in which the surface reaction in two active sites is the controlling step of the process rate. The deactivation rate has been determined from activity-time data, calculated from outlet conversion-time data. Coke precursor formation has been determined that occurs by reaction of three adsorbed molecules of reactant (cyclohexanol) or product (cyclohexene). A greater contribution (bigger parallel contribution) of coke formation from the reactant has been found. Also, the variation of different physical and chemical catalyst properties, such as surface, pore volume, acidity, and coke composition, have been measured at different coke contents, with the result that relationships between coke content and activity and between activity and acidity support the hypothesis of site coverage deactivation, at least for the coke level range achieved in this study (0--4.1 % (w/w), corresponding to an activity decay from 1 to 0.13); hence, the monolayer coke formation over the catalyst surface can be assumed. These results are confirmed by the nonvariation of physical properties.

  3. Deactivation of metastable single-crystal silicon hyperdoped with sulfur

    SciTech Connect

    Simmons, C. B.; Akey, Austin J.; Sullivan, Joseph T.; Buonassisi, Tonio; Krich, Jacob J.; Recht, Daniel; Aziz, Michael J.

    2013-12-28

    Silicon supersaturated with sulfur by ion implantation and pulsed laser melting exhibits broadband optical absorption of photons with energies less than silicon's band gap. However, this metastable, hyperdoped material loses its ability to absorb sub-band gap light after subsequent thermal treatment. We explore this deactivation process through optical absorption and electronic transport measurements of sulfur-hyperdoped silicon subject to anneals at a range of durations and temperatures. The deactivation process is well described by the Johnson-Mehl-Avrami-Kolmogorov framework for the diffusion-mediated transformation of a metastable supersaturated solid solution, and we find that this transformation is characterized by an apparent activation energy of E{sub A}=1.7 ± 0.1 eV. Using this activation energy, the evolution of the optical and electronic properties for all anneal duration-temperature combinations collapse onto distinct curves as a function of the extent of reaction. We provide a mechanistic interpretation of this deactivation based on short-range thermally activated atomic movements of the dopants to form sulfur complexes.

  4. Accumulation of Paprika Carotenoids in Human Plasma and Erythrocytes.

    PubMed

    Nishino, Azusa; Ichihara, Takashi; Takaha, Takeshi; Kuriki, Takashi; Nihei, Hideko; Kawamoto, Kazuhisa; Yasui, Hiroyuki; Maoka, Takashi

    2015-01-01

    The accumulation (incorporation) of paprika carotenoid in human plasma and erythrocytes was investigated. A paprika carotenoid supplement (14 mg/day) was ingested for 4 weeks by 5 young healthy volunteers (3 men and 2 women). After 2 weeks of carotenoid ingestion, the carotenoid levels in plasma and erythrocytes increased by 1.2-fold and 2.2-fold, respectively. Characteristic carotenoids found in paprika (capsanthin, cucurbitaxanthin A, and cryptocapsin) were detected in both plasma and erythrocytes. An oxidative metabolite of capsanthin (capsanthone) was also found in both plasma and erythrocytes.

  5. Carotenoid biosynthesis in extremophilic Deinococcus-Thermus bacteria.

    PubMed

    Tian, Bing; Hua, Yuejin

    2010-11-01

    Bacteria from the phylum Deinococcus-Thermus are known for their resistance to extreme stresses including radiation, oxidation, desiccation and high temperature. Cultured Deinococcus-Thermus bacteria are usually red or yellow pigmented because of their ability to synthesize carotenoids. Unique carotenoids found in these bacteria include deinoxanthin from Deinococcus radiodurans and thermozeaxanthins from Thermus thermophilus. Investigations of carotenogenesis will help to understand cellular stress resistance of Deinococcus-Thermus bacteria. Here, we discuss the recent progress toward identifying carotenoids, carotenoid biosynthetic enzymes and pathways in some species of Deinococcus-Thermus extremophiles. In addition, we also discuss the roles of carotenoids in these extreme bacteria.

  6. Carotenoid composition and in vitro pharmacological activity of rose hips.

    PubMed

    Horváth, Györgyi; Molnár, Péter; Radó-Turcsi, Erika; Deli, József; Kawase, Masami; Satoh, Kazue; Tanaka, Toru; Tani, Satoru; Sakagami, Hiroshi; Gyémánt, Nóra; Molnár, József

    2012-01-01

    The aim of the present study was to compare carotenoid extracts of Rose hips (Rosa canina L.) with regard to their phytochemical profiles and their in vitro anti-Helicobacter pylori (H. pylori), cytotoxic, multidrug resistance (MDR) reversal and radical scavenging activity. Carotenoid composition was investigated in the different fractionation of rose hips, using extraction methods. Six main carotenoids - epimers of neochrome, lutein, zeaxanthin, rubixanthin, lycopene, β,β-carotene - were identified from Rose hips by their chromatographic behavior and UV-visible spectra, which is in accordance with other studies on carotenoids in this plant material. The active principles in the carotenoid extract might differ, depending upon the extraction procedures.

  7. The carotenoid-continuum: carotenoid-based plumage ranges from conspicuous to cryptic and back again

    PubMed Central

    2010-01-01

    Background Carotenoids are frequently used by birds to colour their plumage with green, yellow, orange or red hues, and carotenoid-based colours are considered honest signals of quality, although they may have other functions, such as crypsis. It is usually assumed that red through yellow colours have a signalling function while green is cryptic. Here we challenge this notion using the yellow and green colouration of blue tits (Cyanistes caeruleus), great tits (Parus major) and greenfinches (Carduelis chloris) as a model. Results The relationship between colouration (chroma, computed using visual sensitivities of conspecifics) and detectability (contrast against natural backgrounds as perceived by conspecifics and avian predators) followed a similar curvilinear pattern for yellow and green plumage with minimum detectability at intermediate levels of carotenoid deposition. Thus, for yellow and green plumage, colours at or close to the point of minimum detectability may aid in crypsis. This may be the case for blue and great tit green and yellow plumage, and greenfinch green plumage, all of which had comparably low levels of detectability, while greenfinch yellow plumage was more chromatic and detectable. As yellow and green blue tit colouration are strongly affected by carotenoid availability during moult, variation in pigment availability between habitats may affect the degree of background-matching or the costliness of producing cryptic plumage. Conclusions Increasing carotenoid-deposition in the integument does not always lead to more conspicuous colours. In some cases, such as in blue or great tits, carotenoid deposition may be selected through enhanced background-matching, which in turn suggests that producing cryptic plumage may entail costs. We stress however, that our data do not rule out a signalling function of carotenoid-based plumage in tits. Rather, it shows that alternative functions are plausible and that assuming a signalling function based solely on

  8. Multichannel analyzers at high rates of input

    NASA Technical Reports Server (NTRS)

    Rudnick, S. J.; Strauss, M. G.

    1969-01-01

    Multichannel analyzer, used with a gating system incorporating pole-zero compensation, pile-up rejection, and baseline-restoration, achieves good resolution at high rates of input. It improves resolution, reduces tailing and rate-contributed continuum, and eliminates spectral shift.

  9. A multi-channel waveform digitizer system

    SciTech Connect

    Bieser, F.; Muller, W.F.J. )

    1990-04-01

    The authors report on the design and performance of a multichannel waveform digitizer system for use with the Multiple Sample Ionization Chamber (MUSIC) Detector at the Bevalac. 128 channels of 20 MHz Flash ADC plus 256 word deep memory are housed in a single crate. Digital thresholds and hit pattern logic facilitate zero suppression during readout which is performed over a standard VME bus.

  10. Carotenoids from Haloarchaea and Their Potential in Biotechnology.

    PubMed

    Rodrigo-Baños, Montserrat; Garbayo, Inés; Vílchez, Carlos; Bonete, María José; Martínez-Espinosa, Rosa María

    2015-08-25

    The production of pigments by halophilic archaea has been analysed during the last half a century. The main reasons that sustains this research are: (i) many haloarchaeal species possess high carotenoids production availability; (ii) downstream processes related to carotenoid isolation from haloarchaea is relatively quick, easy and cheap; (iii) carotenoids production by haloarchaea can be improved by genetic modification or even by modifying several cultivation aspects such as nutrition, growth pH, temperature, etc.; (iv) carotenoids are needed to support plant and animal life and human well-being; and (v) carotenoids are compounds highly demanded by pharmaceutical, cosmetic and food markets. Several studies about carotenoid production by haloarchaea have been reported so far, most of them focused on pigments isolation or carotenoids production under different culture conditions. However, the understanding of carotenoid metabolism, regulation, and roles of carotenoid derivatives in this group of extreme microorganisms remains mostly unrevealed. The uses of those haloarchaeal pigments have also been poorly explored. This work summarises what has been described so far about carotenoids production by haloarchaea and their potential uses in biotechnology and biomedicine. In particular, new scientific evidence of improved carotenoid production by one of the better known haloarchaeon (Haloferax mediterranei) is also discussed.

  11. Carotenoids from Haloarchaea and Their Potential in Biotechnology

    PubMed Central

    Rodrigo-Baños, Montserrat; Garbayo, Inés; Vílchez, Carlos; Bonete, María José; Martínez-Espinosa, Rosa María

    2015-01-01

    The production of pigments by halophilic archaea has been analysed during the last half a century. The main reasons that sustains this research are: (i) many haloarchaeal species possess high carotenoids production availability; (ii) downstream processes related to carotenoid isolation from haloarchaea is relatively quick, easy and cheap; (iii) carotenoids production by haloarchaea can be improved by genetic modification or even by modifying several cultivation aspects such as nutrition, growth pH, temperature, etc.; (iv) carotenoids are needed to support plant and animal life and human well-being; and (v) carotenoids are compounds highly demanded by pharmaceutical, cosmetic and food markets. Several studies about carotenoid production by haloarchaea have been reported so far, most of them focused on pigments isolation or carotenoids production under different culture conditions. However, the understanding of carotenoid metabolism, regulation, and roles of carotenoid derivatives in this group of extreme microorganisms remains mostly unrevealed. The uses of those haloarchaeal pigments have also been poorly explored. This work summarises what has been described so far about carotenoids production by haloarchaea and their potential uses in biotechnology and biomedicine. In particular, new scientific evidence of improved carotenoid production by one of the better known haloarchaeon (Haloferax mediterranei) is also discussed. PMID:26308012

  12. Changes in carotenoids during processing and storage of foods.

    PubMed

    Rodriguez-Amaya, D B

    1999-09-01

    Being highly unsaturated, carotenoids are susceptible to isomerization and oxidation during processing and storage of foods. Isomerization of trans-carotenoids to cis-carotenoids, promoted by contact with acids, heat treatment and exposure to light, diminishes the color and the vitamin A activity of carotenoids. The major cause of carotenoid loss, however, is enzymatic and non-enzymatic oxidation, which depends on the availability of oxygen and the carotenoid structure. It is stimulated by light, heat, some metals, enzymes and peroxides and is inhibited by antioxidants. Data on percentage losses of carotenoids during food processing and storage are somewhat conflicting, but carotenoid degradation is known to increase with the destruction of the food cellular structure, increase of surface area or porosity, length and severity of the processing conditions, storage time and temperature, transmission of light and permeability to O2 of the packaging. Contrary to lipid oxidation, for which the mechanism is well established, the oxidation of carotenoids is not well understood. It involves initially epoxidation, formation of apocarotenoids and hydroxylation. Subsequent fragmentations presumably result in a series of compounds of low molecular masses. Completely losing its color and biological activities, the carotenoids give rise to volatile compounds which contribute to the aroma/flavor, desirable in tea and wine and undesirable in dehydrated carrot. Processing can also influence the bioavailability of carotenoids, a topic that is currently of great interest.

  13. A carotenoid health index based on plasma carotenoids and health outcomes.

    PubMed

    Donaldson, Michael S

    2011-12-01

    While there have been many studies on health outcomes that have included measurements of plasma carotenoids, this data has not been reviewed and assembled into a useful form. In this review sixty-two studies of plasma carotenoids and health outcomes, mostly prospective cohort studies or population-based case-control studies, are analyzed together to establish a carotenoid health index. Five cutoff points are established across the percentiles of carotenoid concentrations in populations, from the tenth to ninetieth percentile. The cutoff points (mean ± standard error of the mean) are 1.11 ± 0.08, 1.47 ± 0.08, 1.89 ± 0.08, 2.52 ± 0.13, and 3.07 ± 0.20 µM. For all cause mortality there seems to be a low threshold effect with protection above every cutoff point but the lowest. But for metabolic syndrome and cancer outcomes there tends to be significant positive health outcomes only above the higher cutoff points, perhaps as a triage effect. Based on this data a carotenoid health index is proposed with risk categories as follows: very high risk: <1 µM, high risk: 1-1.5 µM, moderate risk: 1.5-2.5 µM, low risk: 2.5-4 µM, and very low risk: >4 µM. Over 95 percent of the USA population falls into the moderate or high risk category of the carotenoid health index.

  14. Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies.

    PubMed

    Mayne, Susan T; Cartmel, Brenda; Scarmo, Stephanie; Jahns, Lisa; Ermakov, Igor V; Gellermann, Werner

    2013-11-15

    Resonance Raman spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes.

  15. Carotenoids in unexpected places: gall midges, lateral gene transfer, and carotenoid biosynthesis in animals.

    PubMed

    Cobbs, Cassidy; Heath, Jeremy; Stireman, John O; Abbot, Patrick

    2013-08-01

    Carotenoids are conjugated isoprenoid molecules with many important physiological functions in organisms, including roles in photosynthesis, oxidative stress reduction, vision, diapause, photoperiodism, and immunity. Until recently, it was believed that only plants, microorganisms, and fungi were capable of synthesizing carotenoids and that animals acquired them from their diet, but recent studies have demonstrated that two arthropods (pea aphid and spider mite) possess a pair of genes homologous to those required for the first step of carotenoid biosynthesis. Absent in all other known animal genomes, these genes appear to have been acquired by aphids and spider mites in one or several lateral gene transfer events from a fungal donor. We report the third case of fungal carotenoid biosynthesis gene homologs in an arthropod: flies from the family Cecidomyiidae, commonly known as gall midges. Using phylogenetic analyses we show that it is unlikely that lycopene cyclase/phytoene synthase and phytoene desaturase homologs were transferred singly to an ancient arthropod ancestor; instead we propose that genes were transferred independently from related fungal donors after divergence of the major arthropod lineages. We also examine variation in intron placement and copy number of the carotenoid genes that may underlie function in the midges. This trans-kingdom transfer of carotenoid genes may represent a key innovation, underlying the evolution of phytophagy and plant-galling in gall midges and facilitating their extensive diversification across plant lineages.

  16. Resonance Raman Spectroscopic Evaluation of Skin Carotenoids as a Biomarker of Carotenoid Status for Human Studies

    PubMed Central

    Mayne, Susan T.; Cartmel, Brenda; Scarmo, Stephanie; Jahns, Lisa; Ermakov, Igor V.; Gellermann, Werner

    2013-01-01

    Resonance Raman Spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes. PMID:23823930

  17. Ultrafast spectroscopy tracks carotenoid configurations in the orange and red carotenoid proteins from cyanobacteria.

    PubMed

    Šlouf, Václav; Kuznetsova, Valentyna; Fuciman, Marcel; de Carbon, Céline Bourcier; Wilson, Adjélé; Kirilovsky, Diana; Polívka, Tomáš

    2017-01-01

    A quenching mechanism mediated by the orange carotenoid protein (OCP) is one of the ways cyanobacteria protect themselves against photooxidative stress. Here, we present a femtosecond spectroscopic study comparing OCP and RCP (red carotenoid protein) samples binding different carotenoids. We confirmed significant changes in carotenoid configuration upon OCP activation reported by Leverenz et al. (Science 348:1463-1466. doi: 10.1126/science.aaa7234 , 2015) by comparing the transient spectra of OCP and RCP. The most important marker of these changes was the magnitude of the transient signal associated with the carotenoid intramolecular charge-transfer (ICT) state. While OCP with canthaxanthin exhibited a weak ICT signal, it increased significantly for canthaxanthin bound to RCP. On the contrary, a strong ICT signal was recorded in OCP binding echinenone excited at the red edge of the absorption spectrum. Because the carbonyl oxygen responsible for the appearance of the ICT signal is located at the end rings of both carotenoids, the magnitude of the ICT signal can be used to estimate the torsion angles of the end rings. Application of two different excitation wavelengths to study OCP demonstrated that the OCP sample contains two spectroscopically distinct populations, none of which is corresponding to the photoactivated product of OCP.

  18. Influence of Phenylalanine on Carotenoid Aggregation

    NASA Astrophysics Data System (ADS)

    Lu, L.; Ni, X.; Luo, X.

    2015-01-01

    The carotenoids lutein and β-carotene form, in 1:1 ethanol-water mixtures H-aggregates, of different strengths. The effects of phenylalanine on these aggregates were recorded by UV-Vis absorption, steady-state fluorescence, and Raman spectra. The H-aggregate of lutein was characterized by a large 78 nm blue shift in the absorption spectra, confirming the strong coupling between hydroxyl groups of adjacent molecules. The 15 nm blue shift in the β-carotene mixture also indicates that it was assembled by weak coupling between polyenes. After adding phenylalanine, the reducing absorption strength of the aggregates of lutein and reappearance of vibrational substructure indicate that the hydroxyl and amino groups of phenylalanine may coordinate to lutein and disaggregate the H-aggregates. However, phenylalanine had no effect on aggregates of β-carotene. The Raman spectra show three bands of carotenoids whose intensities decreased with increasing phenylalanine concentration. The frequency of ν1 corresponding to the length of the conjugated region was more sensitive to the solution of lutein. This coordination of phenylalanine to lutein could increase the length of the conjugated region. In addition, phenylalanine significantly affected the excited electronic states of carotenoids, which were crucial in the energy transfer from carotenoids to chlorophyll a in vivo.

  19. Long-lived coherence in carotenoids

    NASA Astrophysics Data System (ADS)

    Davis, J. A.; Cannon, E.; Van Dao, L.; Hannaford, P.; Quiney, H. M.; Nugent, K. A.

    2010-08-01

    We use two-colour vibronic coherence spectroscopy to observe long-lived vibrational coherences in the ground electronic state of carotenoid molecules, with decoherence times in excess of 1 ps. Lycopene and spheroidene were studied isolated in solution, and within the LH2 light-harvesting complex extracted from purple bacteria. The vibrational coherence time is shown to increase significantly for the carotenoid in the complex, providing further support to previous assertions that long-lived electronic coherences in light-harvesting complexes are facilitated by in-phase motion of the chromophores and surrounding proteins. Using this technique, we are also able to follow the evolution of excited state coherences and find that for carotenoids in the light-harvesting complex the langS2|S0rang superposition remains coherent for more than 70 fs. In addition to the implications of this long electronic decoherence time, the extended coherence allows us to observe the evolution of the excited state wavepacket. These experiments reveal an enhancement of the vibronic coupling to the first vibrational level of the C-C stretching mode and/or methyl-rocking mode in the ground electronic state 70 fs after the initial excitation. These observations open the door to future experiments and modelling that may be able to resolve the relaxation dynamics of carotenoids in solution and in natural light-harvesting systems.

  20. The regulation of carotenoid pigmentation in flowers.

    PubMed

    Zhu, Changfu; Bai, Chao; Sanahuja, Georgina; Yuan, Dawei; Farré, Gemma; Naqvi, Shaista; Shi, Lianxuan; Capell, Teresa; Christou, Paul

    2010-12-01

    Carotenoids fulfill many processes that are essential for normal growth and development in plants, but they are also responsible for the breathtaking variety of red-to-yellow colors we see in flowers and fruits. Although such visual diversity helps to attract pollinators and encourages herbivores to distribute seeds, humans also benefit from the aesthetic properties of flowers and an entire floriculture industry has developed on the basis that new and attractive varieties can be produced. Over the last decade, much has been learned about the impact of carotenoid metabolism on flower color development and the molecular basis of flower color. A number of different regulatory mechanisms have been described ranging from the transcriptional regulation of genes involved in carotenoid synthesis to the control of carotenoid storage in sink organs. This means we can now explain many of the natural colorful varieties we see around us and also engineer plants to produce flowers with novel and exciting varieties that are not provided by nature.

  1. Continuous production of carotenoids from Dunaliella salina.

    PubMed

    Kleinegris, Dorinde M M; Janssen, Marcel; Brandenburg, Willem A; Wijffels, René H

    2011-03-07

    During the in situ extraction of β-carotene from Dunaliella salina, the causal relationship between carotenoid extraction and cell death indicated that cell growth and cell death should be at equilibrium for a continuous in situ extraction process. In a flat-panel photobioreactor that was operated as a turbidostat cell numbers of stressed cells were kept constant while attaining a continuous well-defined light-stress. In this way it was possible to study the balance between cell growth and cell death and determine whether both could be increased to reach higher volumetric productivities of carotenoids. In the two-phase system a volumetric productivity of 8.3 mg β-carotene L(RV)(-1)d(-1) was obtained. In situ extraction contributed only partly to this productivity. The major part came from net production of carotenoid-rich biomass, due to a high growth rate of the cells and subsequent dilution of the reactor. To reach equilibrium between cell growth and cell death, sparging rates of dodecane could have been increased. However, already at the applied sparging rate of 286 L(dod)L(RV)(-1)min(-1) emulsion formation of the dodecane in the aqueous phase appeared. In a turbidostat without in situ extraction a volumetric productivity of 13.5 mg β-caroteneL(RV)(-1)d(-1) was reached, solely based on the continuous production of carotenoid-rich biomass. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Galloxanthin, a carotenoid from the chicken retina.

    PubMed

    WALD, G

    1948-05-20

    A new carotenoid has been isolated from the chicken retina for which the name galloxanthin is proposed. This substance has the properties of a hydroxy carotenoid or xanthophyll. It has not yet been crystallized. On a chromatogram of calcium carbonate it is adsorbed just below astaxanthin and above lutein. The absorption spectrum of galloxanthin lies in a region where natural carotenoids have not ordinarily been found. Its main, central absorption band falls at about 400 mmicro. The position of its spectrum suggests a conjugated system of eight double bonds. This relatively short polyene structure must be reconciled with very strong adsorption affinities. With antimony trichloride, galloxanthin yields a deep blue product, possessing a main absorption band at 785 to 795 mmicro, and a secondary maximum at about 710 mmicro which may not be due to galloxanthin itself. Galloxanthin appears to be one of the carotenoid filter pigments associated with cone vision in the chicken. It may act as an auxiliary to the other filter pigments in differentiating colors; or its primary function may be to exclude violet and near ultraviolet radiations for which the eye has a large chromatic aberration.

  3. Accumulation and bioavailability of dietary carotenoids in vegetable crops.

    PubMed

    Kopsell, Dean A; Kopsell, David E

    2006-10-01

    Carotenoids are lipid-soluble pigments found in many vegetable crops that are reported to have the health benefits of cancer and eye disease reduction when consumed in the diet. Research shows that environmental and genetic factors can significantly influence carotenoid concentrations in vegetable crops, and that changing cultural management strategies could be advantageous, resulting in increased vegetable carotenoid concentrations. Improvements in vegetable carotenoid levels have been achieved using traditional breeding methods and molecular transformations to stimulate biosynthetic pathways. Postharvest and processing activities can alter carotenoid chemistry, and ultimately affect bioavailability. Bioavailability data emphasize the importance of carotenoid enhancement in vegetable crops and the need to characterize potential changes in carotenoid composition during cultivation, storage and processing before consumer purchase.

  4. Oxidative stress does not influence carotenoid mobilization and plumage pigmentation.

    PubMed

    Isaksson, Caroline; Andersson, Staffan

    2008-02-07

    Oxidative stress has been suggested to create a link between 'good genes' and carotenoid coloration via an allocation conflict between external pigmentation and internal antioxidant functions. However, although carotenoid displays have been extensively investigated, there are no experimental tests of the antioxidant efficiency of carotenoids in vivo. We induced oxidative stress in a small passerine (the great tit, Parus major) under both carotenoid deprivation and supplementation, and investigated the effect on carotenoid mobilization (i.e. plasma) and allocation (i.e. deposition in feather incorporation and liver storage). We found no effects of the stressor on either mobilization or allocation of carotenoids. These results reject the previously suggested superior role of carotenoid's function as antioxidant in vivo with important implications for signal content and honesty.

  5. A review on factors influencing bioaccessibility and bioefficacy of carotenoids.

    PubMed

    Priyadarshani, A M B

    2017-05-24

    Vitamin A deficiency is one of the most prevalent deficiency disorders in the world. As shown by many studies plant food based approaches have a real potential on prevention of vitamin A deficiency in a sustainable way. Carotenoids are important as precursors of vitamin A as well as for prevention of cancers, coronary heart diseases, age-related macular degeneration, cataract etc. Bioaccessibility and bioefficacy of carotenoids are known to be influenced by numerous factors including dietary factors such as fat, fiber, dosage of carotenoid, location of carotenoid in the plant tissue, heat treatment, particle size of food, carotenoid species, interactions among carotenoids, isomeric form and molecular linkage and subject characteristics. Therefore even when carotenoids are found in high quantities in plant foods their utilization may be unsatisfactory because some factors are known to interfere as negative effectors.

  6. Macular and serum carotenoid concentrations in patients with malabsorption syndromes.

    PubMed

    Ward, Matthew S; Zhao, Da You; Bernstein, Paul S

    2008-03-01

    The carotenoids lutein and zeaxanthin are believed to protect the human macula by absorbing blue light and quenching free radicals. Intestinal malabsorption syndromes such as celiac and Crohn's disease are known to cause deficiencies of lipid-soluble nutrients. We hypothesized that subjects with nutrient malabsorption syndromes will demonstrate lower carotenoid levels in the macula and blood, and that these lower levels may correlate with early-onset maculopathy. Resonance Raman spectrographic (RRS) measurements of macular carotenoid levels were collected from subjects with and without a history of malabsorption syndromes. Carotenoids were extracted from serum and analyzed by high performance liquid chromatography (HPLC). Subjects with malabsorption (n = 22) had 37% lower levels of macular carotenoids on average versus controls (n = 25, P < 0.001). Malabsorption was not associated with decreased serum carotenoid levels. Convincing signs of early maculopathy were not observed. We conclude that intestinal malabsorption results in lower macular carotenoid levels.

  7. Physalis alkekengi carotenoidic extract inhibitor of soybean lipoxygenase-1 activity.

    PubMed

    Chedea, Veronica Sanda; Pintea, Adela; Bunea, Andrea; Braicu, Cornelia; Stanila, Andreea; Socaciu, Carmen

    2014-01-01

    The aim of this study was to evaluate the effect of the carotenoidic saponified extract of Physalis alkekengi sepals (PA) towards the lipoxygenase (LOX) oxidation of linoleic acid. Lipoxygenase activity in the presence of carotenoids, standard and from extract, was followed by its kinetic behaviour determining the changes in absorption at 234 nm. The standard carotenoids used were β-carotene (β-car), lutein (Lut), and zeaxanthin (Zea). The calculated enzymatic specific activity (ESA) after 600 s of reaction proves that PA carotenoidic extract has inhibitory effect on LOX oxidation of linoleic acid. A longer polyenic chain of carotenoid structure gives a higher ESA during the first reaction seconds. This situation is not available after 600 s of reaction and may be due to a destruction of this structure by cooxidation of carotenoids, besides the classical LOX reaction. The PA carotenoidic extract inhibiting the LOX-1 reaction can be considered a source of lipoxygenase inhibitors.

  8. Intraspecific Variation in Carotenoids of Brassica oleracea var. sabellica.

    PubMed

    Mageney, Vera; Baldermann, Susanne; Albach, Dirk C

    2016-04-27

    Carotenoids are best known as a source of natural antioxidants. Physiologically, carotenoids are part of the photoprotection in plants as they act as scavengers of reactive oxygen species (ROS). An important source of carotenoids in European food is Brassica oleracea. Focusing on the most abundant carotenoids, we estimated the contents of ß-carotene, (9Z)-neoxanthin, zeaxanthin, and lutein as well as those of chlorophylls a and b to assess their variability in Brassica oleracea var. sabellica. Our analyses included more than 30 cultivars categorized in five distinct sets grouped according to morphological characteristics or geographical origin. Our results demonstrated specific carotenoid patterns characteristic for American, Italian, and red-colored kale cultivars. Moreover, we demonstrated a tendency of high zeaxanthin proportions under traditional harvest conditions, which accord to low-temperature regimes. We also compared the carotenoid patterns of self-generated hybrid lines. Corresponding findings indicated that crossbreeding has a high potential for carotenoid content optimization in kale.

  9. Identification of Plastoglobules as a Site of Carotenoid Cleavage

    PubMed Central

    Rottet, Sarah; Devillers, Julie; Glauser, Gaétan; Douet, Véronique; Besagni, Céline; Kessler, Felix

    2016-01-01

    Carotenoids play an essential role in light harvesting and protection from excess light. During chloroplast senescence carotenoids are released from their binding proteins and are eventually metabolized. Carotenoid cleavage dioxygenase 4 (CCD4) is involved in carotenoid breakdown in senescing leaf and desiccating seed, and is part of the proteome of plastoglobules (PG), which are thylakoid-associated lipid droplets. Here, we demonstrate that CCD4 is functionally active in PG. Leaves of Arabidopsis thaliana ccd4 mutants constitutively expressing CCD4 fused to yellow fluorescent protein showed strong fluorescence in PG and reduced carotenoid levels upon dark-induced senescence. Lipidome-wide analysis indicated that β-carotene, lutein, and violaxanthin were the principle substrates of CCD4 in vivo and were cleaved in senescing chloroplasts. Moreover, carotenoids were shown to accumulate in PG of ccd4 mutant plants during senescence, indicating translocation of carotenoids to PG prior to degradation. PMID:28018391

  10. Oxidative stress does not influence carotenoid mobilization and plumage pigmentation

    PubMed Central

    Isaksson, Caroline; Andersson, Staffan

    2007-01-01

    Summary Oxidative stress has been suggested to create a link between ‘good genes’ and carotenoid coloration via an allocation conflict between external pigmentation and internal antioxidant functions. However, although carotenoid displays have been extensively investigated, there are no experimental tests of the antioxidant efficiency of carotenoids in vivo. We induced oxidative stress in a small passerine (the great tit, Parus major) under both carotenoid deprivation and supplementation, and investigated the effect on carotenoid mobilization (i.e. plasma) and allocation (i.e. deposition in feather incorporation and liver storage). We found no effects of the stressor on either mobilization or allocation of carotenoids. These results reject the previously suggested superior role of carotenoid's function as antioxidant in vivo with important implications for signal content and honesty. PMID:18029305

  11. Carotenoid biosynthesis and overproduction in Corynebacterium glutamicum

    PubMed Central

    2012-01-01

    Background Corynebacterium glutamicum contains the glycosylated C50 carotenoid decaprenoxanthin as yellow pigment. Starting from isopentenyl pyrophosphate, which is generated in the non-mevalonate pathway, decaprenoxanthin is synthesized via the intermediates farnesyl pyrophosphate, geranylgeranyl pyrophosphate, lycopene and flavuxanthin. Results Here, we showed that the genes of the carotenoid gene cluster crtE-cg0722-crtBIYeYfEb are co-transcribed and characterized defined gene deletion mutants. Gene deletion analysis revealed that crtI, crtEb, and crtYeYf, respectively, code for the only phytoene desaturase, lycopene elongase, and carotenoid C45/C50 ɛ-cyclase, respectively. However, the genome of C. glutamicum also encodes a second carotenoid gene cluster comprising crtB2I2-1/2 shown to be co-transcribed, as well. Ectopic expression of crtB2 could compensate for the lack of phytoene synthase CrtB in C. glutamicum ΔcrtB, thus, C. glutamicum possesses two functional phytoene synthases, namely CrtB and CrtB2. Genetic evidence for a crtI2-1/2 encoded phytoene desaturase could not be obtained since plasmid-borne expression of crtI2-1/2 did not compensate for the lack of phytoene desaturase CrtI in C. glutamicum ΔcrtI. The potential of C. glutamicum to overproduce carotenoids was estimated with lycopene as example. Deletion of the gene crtEb prevented conversion of lycopene to decaprenoxanthin and entailed accumulation of lycopene to 0.03 ± 0.01 mg/g cell dry weight (CDW). When the genes crtE, crtB and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were overexpressed in C. glutamicum ΔcrtEb intensely red-pigmented cells and an 80 fold increased lycopene content of 2.4 ± 0.3 mg/g CDW were obtained. Conclusion C. glutamicum possesses a certain degree of redundancy in the biosynthesis of the C50 carotenoid decaprenoxanthin as it possesses two functional phytoene synthase genes. Already metabolic engineering of only the terminal reactions

  12. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    PubMed Central

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding. PMID:25965548

  13. Multichannel compressive sensing MRI using noiselet encoding.

    PubMed

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  14. What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards.

    PubMed

    Kopena, Renata; López, Pilar; Martín, José

    2014-12-01

    In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards (Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

  15. What are carotenoids signaling? Immunostimulatory effects of dietary vitamin E, but not of carotenoids, in Iberian green lizards

    NASA Astrophysics Data System (ADS)

    Kopena, Renata; López, Pilar; Martín, José

    2014-12-01

    In spite that carotenoid-based sexual ornaments are one of the most popular research topics in sexual selection of animals, the antioxidant and immunostimulatory role of carotenoids, presumably signaled by these colorful ornaments, is still controversial. It has been suggested that the function of carotenoids might not be as an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards ( Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on phytohaemagglutinin (PHA)-induced skin-swelling immune response and body condition. Lizards that were supplemented with vitamin E alone or a combination of vitamin E and carotenoids had greater immune responses than control lizards, but animals supplemented with carotenoids alone had lower immune responses than lizards supplemented with vitamin E and did not differ from control lizards. These results support the hypothesis that carotenoids in green lizards are not effective as immunostimulants, but that they may be visually signaling the immunostimulatory effects of non-pigmentary vitamin E. In contrast, lizards supplemented with carotenoids alone have higher body condition gains than lizards in the other experimental groups, suggesting that carotenoids may be still important to improve condition.

  16. Dissecting carotenoid from structural components of carotenoid-based coloration: a field experiment with great tits (Parus major).

    PubMed

    Jacot, Alain; Romero-Diaz, Cristina; Tschirren, Barbara; Richner, Heinz; Fitze, Patrick S

    2010-07-01

    Carotenoid-based yellowish to red plumage colors are widespread visual signals used in sexual and social communication. To understand their ultimate signaling functions, it is important to identify the proximate mechanism promoting variation in coloration. Carotenoid-based colors combine structural and pigmentary components, but the importance of the contribution of structural components to variation in pigment-based colors (i.e., carotenoid-based colors) has been undervalued. In a field experiment with great tits (Parus major), we combined a brood size manipulation with a simultaneous carotenoid supplementation in order to disentangle the effects of carotenoid availability and early growth condition on different components of the yellow breast feathers. By defining independent measures of feather carotenoid content (absolute carotenoid chroma) and background structure (background reflectance), we demonstrate that environmental factors experienced during the nestling period, namely, early growth conditions and carotenoid availability, contribute independently to variation in yellow plumage coloration. While early growth conditions affected the background reflectance of the plumage, the availability of carotenoids affected the absolute carotenoid chroma, the peak of maximum ultraviolet reflectance, and the overall shape, that is, chromatic information of the reflectance curves. These findings demonstrate that environment-induced variation in background structure contributes significantly to intraspecific variation in yellow carotenoid-based plumage coloration.

  17. Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro

    PubMed Central

    Zhang, Lancui; Ma, Gang; Kato, Masaya; Yamawaki, Kazuki; Takagi, Toshihiko; Kiriiwa, Yoshikazu; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Nesumi, Hirohisa

    2012-01-01

    In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit

  18. Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro.

    PubMed

    Zhang, Lancui; Ma, Gang; Kato, Masaya; Yamawaki, Kazuki; Takagi, Toshihiko; Kiriiwa, Yoshikazu; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Nesumi, Hirohisa

    2012-01-01

    In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit

  19. Mate choice for a male carotenoid-based ornament is linked to female dietary carotenoid intake and accumulation

    PubMed Central

    2012-01-01

    Background The coevolution of male traits and female mate preferences has led to the elaboration and diversification of sexually selected traits; however the mechanisms that mediate trait-preference coevolution are largely unknown. Carotenoid acquisition and accumulation are key determinants of the expression of male sexually selected carotenoid-based coloration and a primary mechanism maintaining the honest information content of these signals. Carotenoids also influence female health and reproduction in ways that may alter the costs and benefits of mate choice behaviours and thus provide a potential biochemical link between the expression of male traits and female preferences. To test this hypothesis, we manipulated the dietary carotenoid levels of captive female house finches (Carpodacus mexicanus) and assessed their mate choice behavior in response to color-manipulated male finches. Results Females preferred to associate with red males, but carotenoid supplementation did not influence the direction or strength of this preference. Females receiving a low-carotenoid diet were less responsive to males in general, and discrimination among the colorful males was positively linked to female plasma carotenoid levels at the beginning of the study when the diet of all birds was carotenoid-limited. Conclusions Although female preference for red males was not influenced by carotenoid intake, changes in mating responsiveness and discrimination linked to female carotenoid status may alter how this preference is translated into choice. The reddest males, with the most carotenoid rich plumage, tend to pair early in the breeding season. If carotenoid-related variations in female choice behaviour shift the timing of pairing, then they have the potential to promote assortative mating by carotenoid status and drive the evolution of carotenoid-based male plumage coloration. PMID:22233462

  20. Carotenoid Production by Halophilic Archaea Under Different Culture Conditions.

    PubMed

    Calegari-Santos, Rossana; Diogo, Ricardo Alexandre; Fontana, José Domingos; Bonfim, Tania Maria Bordin

    2016-05-01

    Carotenoids are pigments that may be used as colorants and antioxidants in food, pharmaceutical, and cosmetic industries. Since they also benefit human health, great efforts have been undertaken to search for natural sources of carotenoids, including microbial ones. The optimization of culture conditions to increase carotenoid yield is one of the strategies used to minimize the high cost of carotenoid production by microorganisms. Halophilic archaea are capable of producing carotenoids according to culture conditions. Their main carotenoid is bacterioruberin with 50 carbon atoms. In fact, the carotenoid has important biological functions since it acts as cell membrane reinforcement and it protects the microorganism against DNA damaging agents. Moreover, carotenoid extracts from halophilic archaea have shown high antioxidant capacity. Therefore, current review summarizes the effect of different culture conditions such as salt and carbon source concentrations in the medium, light incidence, and oxygen tension on carotenoid production by halophilic archaea and the strategies such as optimization methodology and two-stage cultivation already used to increase the carotenoid yield of these microorganisms.

  1. Cortical deactivation induced by subcortical network dysfunction in limbic seizures

    PubMed Central

    Englot, Dario J.; Modi, Badri; Mishra, Asht M.; DeSalvo, Matthew; Hyder, Fahmeed; Blumenfeld, Hal

    2009-01-01

    Normal human consciousness may be impaired by two possible routes: direct reduced function in widespread cortical regions, or indirect disruption of subcortical activating systems. The route through which temporal lobe limbic seizures impair consciousness is not known. We recently developed an animal model which, like human limbic seizures, exhibits neocortical deactivation including cortical slow waves and reduced cortical cerebral blood flow (CBF). We now find through functional MRI (fMRI) that electrically-stimulated hippocampal seizures in rats cause increased activity in subcortical structures including the septal area and mediodorsal thalamus, along with reduced activity in frontal, cingulate, and retrosplenial cortex. Direct recordings from the hippocampus, septum, and medial thalamus demonstrated fast poly-spike activity associated with increased neuronal firing and CBF, while frontal cortex showed slow oscillations with decreased neuronal firing and CBF. Stimulation of septal area, but not hippocampus or medial thalamus, in the absence of a seizure resulted in cortical deactivation with slow oscillations and behavioral arrest, resembling changes seen during limbic seizures. Transecting the fornix, the major route from hippocampus to subcortical structures, abolished the negative cortical and behavioral effects of seizures. Cortical slow oscillations and behavioral arrest could be reconstituted in fornix-lesioned animals by inducing synchronous activity in the hippocampus and septal area, implying involvement of a downstream region converged upon by both structures. These findings suggest that limbic seizures may cause neocortical deactivation indirectly, through impaired subcortical function. If confirmed, subcortical networks may represent a target for therapies aimed at preserving consciousness in human temporal lobe seizures. PMID:19828814

  2. Activated and deactivated functional brain areas in the Deqi state

    PubMed Central

    Huang, Yong; Zeng, Tongjun; Zhang, Guifeng; Li, Ganlong; Lu, Na; Lai, Xinsheng; Lu, Yangjia; Chen, Jiarong

    2012-01-01

    We compared the activities of functional regions of the brain in the Deqi versus non-Deqi state, as reported by physicians and subjects during acupuncture. Twelve healthy volunteers received sham and true needling at the Waiguan (TE5) acupoint. Real-time cerebral functional MRI showed that compared with non-sensation after sham needling, true needling activated Brodmann areas 3, 6, 8, 9, 10, 11, 13, 20, 21, 37, 39, 40, 43, and 47, the head of the caudate nucleus, the parahippocampal gyrus, thalamus and red nucleus. True needling also deactivated Brodmann areas 1, 2, 3, 4, 5, 6, 7, 9, 10, 18, 24, 31, 40 and 46. PMID:25538761

  3. PUREX/UO3 Facilities deactivation lessons learned history

    SciTech Connect

    Gerber, M.S.

    1996-09-19

    Disconnecting the criticality alarm permanently in June 1996 signified that the hazards in the PUREX (plutonium-uranium extraction) plant had been so removed and reduced that criticality was no longer a credible event. Turning off the PUREX criticality alarm also marked a salient point in a historic deactivation project, 1 year before its anticipated conclusion. The PUREX/UO3 Deactivation Project began in October 1993 as a 5-year, $222.5- million project. As a result of innovations implemented during 1994 and 1995, the project schedule was shortened by over a year, with concomitant savings. In 1994, the innovations included arranging to send contaminated nitric acid from the PUREX Plant to British Nuclear Fuels, Limited (BNFL) for reuse and sending metal solutions containing plutonium and uranium from PUREX to the Hanford Site tank farms. These two steps saved the project $36.9- million. In 1995, reductions in overhead rate, work scope, and budget, along with curtailed capital equipment expenditures, reduced the cost another $25.6 million. These savings were achieved by using activity-based cost estimating and applying technical schedule enhancements. In 1996, a series of changes brought about under the general concept of ``reengineering`` reduced the cost approximately another $15 million, and moved the completion date to May 1997. With the total savings projected at about $75 million, or 33.7 percent of the originally projected cost, understanding how the changes came about, what decisions were made, and why they were made becomes important. At the same time sweeping changes in the cultural of the Hanford Site were taking place. These changes included shifting employee relations and work structures, introducing new philosophies and methods in maintaining safety and complying with regulations, using electronic technology to manage information, and, adopting new methods and bases for evaluating progress. Because these changes helped generate cost savings and were

  4. Rupture loop annex ion exchange RLAIX vault deactivation

    SciTech Connect

    Ham, J.E.; Harris, D.L., Westinghouse Hanford

    1996-08-01

    This engineering report documents the deactivation, stabilization and final conditions of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located northwest of the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns, piping debris, and column liquid were removed from the vault, packaged and shipped for disposal. The vault walls and floor were decontaminated, and portions of the vault were painted to fix loose contamination. Process piping and drains were plugged, and the cover blocks and rain cover were installed. Upon closure,the vault was empty, stabilized, isolated.

  5. Metabolic engineering for the microbial production of carotenoids and related products with a focus on the rare C50 carotenoids.

    PubMed

    Heider, Sabine A E; Peters-Wendisch, Petra; Wendisch, Volker F; Beekwilder, Jules; Brautaset, Trygve

    2014-05-01

    Carotenoids, a subfamily of terpenoids, are yellow- to red-colored pigments synthesized by plants, fungi, algae, and bacteria. They are ubiquitous in nature and take over crucial roles in many biological processes as for example photosynthesis, vision, and the quenching of free radicals and singlet oxygen. Due to their color and their potential beneficial effects on human health, carotenoids receive increasing attention. Carotenoids can be classified due to the length of their carbon backbone. Most carotenoids have a C40 backbone, but also C30 and C50 carotenoids are known. All carotenoids are derived from isopentenyl pyrophosphate (IPP) as a common precursor. Pathways leading to IPP as well as metabolic engineering of IPP synthesis and C40 carotenoid production have been reviewed expertly elsewhere. Since C50 carotenoids are synthesized from the C40 carotenoid lycopene, we will summarize common strategies for optimizing lycopene production and we will focus our review on the characteristics, biosynthesis, glycosylation, and overproduction of C50 carotenoids.

  6. Carotenoid 3',4'-desaturase is involved in carotenoid biosynthesis in the radioresistant bacterium Deinococcus radiodurans.

    PubMed

    Tian, Bing; Sun, Zongtao; Xu, Zhenjian; Shen, Shaochuan; Wang, Hu; Hua, Yuejin

    2008-12-01

    Deinococcus radiodurans strain R1 synthesizes deinoxanthin, a unique carotenoid product, which contributes to cell resistance following various stresses. The biosynthetic pathway of deinoxanthin is unclear, although several enzymes are presumed to be involved. The gene (dr2250) predicted by gene homologue analysis to encode carotenoid 3',4'-desaturase (CrtD) was deleted to investigate its function. A mutant deficient in the gene homologue of crtLm (dr0801) was also constructed to verify the catalytic function of the gene product in the native host. Carotenoid analysis of the resultant mutants verified that DR2250 encodes carotenoid 3',4'-desaturase, which catalyses the C-3',4'-desaturation of the monocyclic precursor of deinoxanthin but not acyclic carotenoids. Mutation of the gene homologue of crtLm (dr0801) resulted in accumulation of lycopene, confirming that it encodes the lycopene cyclase in the native host. The lack of CrtD decreased the antioxidant capacity of the mutant deficient in dr2250 compared with the wild-type, indicating that the C-3',4'-desaturation step contributes to the antioxidant capacity of deinoxanthin in D. radiodurans.

  7. Feasibility of multichannel human cochlear nucleus stimulation.

    PubMed

    Luetje, C M; Whittaker, C K; Geier, L; Mediavilla, S J; Shallop, J K

    1992-01-01

    Bipolar electrical stimulation of the brainstem cochlear nucleus (CN) following acoustic tumor removal in an only-hearing ear can provide beneficial hearing. However, the benefits of multichannel stimulation have yet to be defined. Following removal of a second acoustic tumor in a patient with neurofibromatosis 2, a Nucleus mini-22 channel implant device was inserted with the electrode array tip from the foramen of Luschka cephalad along the root entry zone of the eighth nerve, secured by a single suture superficially in the brain stem. Initial stimulation on the sixth postoperative day indicated that electrodes 18 to 22 were capable of CN stimulation without seventh nerve stimulation. Presumed electrode migration precluded further CN stimulation 1 month later. This report illustrates the feasibility of brainstem CN stimulation with an existing multichannel system.

  8. Andreev spin qubits in multichannel Rashba nanowires

    NASA Astrophysics Data System (ADS)

    Park, Sunghun; Yeyati, A. Levy

    2017-09-01

    We theoretically analyze the Andreev bound states and their coupling to external radiation in superconductor-nanowire-superconductor Josephson junctions. We provide an effective Hamiltonian for the junction projected onto the Andreev level subspace and incorporating the effects of nanowire multichannel structure, Rashba spin-orbit coupling, and Zeeman field. Based on this effective model, we investigate the dependence of the Andreev levels and the matrix elements of the current operator on system parameters such as chemical potential, nanowire dimensions, and normal transmission. We show that the combined effect of the multichannel structure and the spin-orbit coupling gives rise to finite current matrix elements between odd-parity states having different spin polarizations. Moreover, our analytical results allow to determine the appropriate parameters range for the detection of transitions between even as well as odd states in circuit-QED-like experiments, which may provide a way for the Andreev spin-qubit manipulation.

  9. MCA: a multichannel approach to SAR autofocus.

    PubMed

    Morrison, Robert L; Do, Minh N; Munson, David C

    2009-04-01

    We present a new noniterative approach to synthetic aperture radar (SAR) autofocus, termed the multichannel autofocus (MCA) algorithm. The key in the approach is to exploit the multichannel redundancy of the defocusing operation to create a linear subspace, where the unknown perfectly focused image resides, expressed in terms of a known basis formed from the given defocused image. A unique solution for the perfectly focused image is then directly determined through a linear algebraic formulation by invoking an additional image support condition. The MCA approach is found to be computationally efficient and robust and does not require prior assumptions about the SAR scene used in existing methods. In addition, the vector-space formulation of MCA allows sharpness metric optimization to be easily incorporated within the restoration framework as a regularization term. We present experimental results characterizing the performance of MCA in comparison with conventional autofocus methods and discuss the practical implementation of the technique.

  10. Coupling output of multichannel high power microwaves

    SciTech Connect

    Li Guolin; Shu Ting; Yuan Chengwei; Zhang Jun; Yang Jianhua; Jin Zhenxing; Yin Yi; Wu Dapeng; Zhu Jun; Ren Heming; Yang Jie

    2010-12-15

    The coupling output of multichannel high power microwaves is a promising technique for the development of high power microwave technologies, as it can enhance the output capacities of presently studied devices. According to the investigations on the spatial filtering method and waveguide filtering method, the hybrid filtering method is proposed for the coupling output of multichannel high power microwaves. As an example, a specific structure is designed for the coupling output of S/X/X band three-channel high power microwaves and investigated with the hybrid filtering method. In the experiments, a pulse of 4 GW X band beat waves and a pulse of 1.8 GW S band microwave are obtained.

  11. Modification of carotenoid levels by abscission agents and expression of carotenoid biosynthetic genes in 'valencia' sweet orange.

    PubMed

    Alferez, Fernando; Pozo, Luis V; Rouseff, Russell R; Burns, Jacqueline K

    2013-03-27

    The effect of 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) and ethephon on peel color, flavedo carotenoid gene expression, and carotenoid accumulation was investigated in mature 'Valencia' orange ( Citrus sinensis L. Osbeck) fruit flavedo at three maturation stages. Abscission agent application altered peel color. CMNP was more effective than ethephon in promoting green-to-red (a) and blue-to-yellow (b) color at the middle and late maturation stages and total carotenoid changes at all maturation stages. Altered flow of carotenoid precursors during maturation due to abscission agents was suggested by changes in phytoene desaturase (Pds) and ζ-carotene desaturase (Zds) gene expression. However, each abscission agent affected downstream expression differentially. Ethephon application increased β-carotene hydroxilase (β-Chx) transcript accumulation 12-fold as maturation advanced from the early to middle and late stages. CMNP markedly increased β- and ε-lycopene cyclase (Lcy) transcript accumulation 45- and 15-fold, respectively, at midmaturation. Patterns of carotenoid accumulation in flavedo were supported in part by gene expression changes. CMNP caused greater accumulation of total flavedo carotenoids at all maturation stages when compared with ethephon or controls. In general, CMNP treatment increased total red carotenoids more than ethephon or the control but decreased total yellow carotenoids at each maturation stage. In control fruit flavedo, total red carotenoids increased and yellow carotenoids decreased as maturation progressed. Trends in total red carotenoids during maturation were consistent with measured a values. Changes in carotenoid accumulation and expression patterns in flavedo suggest that regulation of carotenoid accumulation is under transcriptional, translational, and post-translational control.

  12. Activation and deactivation of high concentration arsenic with some evidence of precipitation

    SciTech Connect

    Rousseau, P.M.; Griffin, P.B.; Plummer, J.D.; Carey, P.G.

    1992-12-29

    Using box-shaped profiles created by laser melt annealing, the authors investigate the kinetics of arsenic activation and deactivation. They find deactivation shows no history effects, which can be consistent either with clustering or precipitation for the cases considered. For activation, they notice it occurs on very short time scales, followed by a slower deactivation process. This is suggestive evidence that at least some precipitation occurs.

  13. Multichannel dynamical symmetry and heavy ion resonances

    SciTech Connect

    Cseh, J. H-4001 Debrecen Pf. 51 )

    1994-10-01

    The concept of the multichannel dynamical symmetry is introduced. This symmetry may show up in an atomic nucleus due to its different cluster configurations, and connects the interactions of distinct reaction channels. The correlated distribution of different cluster states at low and high energies can serve as a signature of it. An application of the [sup 28]Si nucelus is performed in terms of the [sup 24]Mg+[alpha] and [sup 12]C+[sup 16]O fragmentations.

  14. Optical absorption spectra of dications of carotenoids

    SciTech Connect

    Jeevarajan, J.A.; Wei, C.C.; Jeevarajan, A.S.; Kispert, L.D.

    1996-04-04

    Quantitative optical absorption spectra of the cation radicals and the dications of canthaxanthin (I), {beta}carotene (II), 7`-cyano-7`-ethoxycarbonyl-7`-apo-{beta}-carotene (III), and 7`,7`-dimethyl-7`-apo-{beta}-carotene (IV) in dichloromethane solution are reported. Exclusive formation of dications occurs when the carotenoids are oxidized with ferric chloride. Addition of neutral carotenoid to the dications results in equilibrium formation of cation radicals. Oxidation with iodine in dichloromethane affords only cation radicals; electrochemical oxidation under suitable conditions yields both dications and cation radicals. Values of the optical parameters depend on the nature of the oxidative medium. The oscillator strengths calculated for gas phase cation radicals and dications of I-IV using the INDO/S method show the same trend as the experimental values. 31 refs., 4 figs., 2 tabs.

  15. Carotenoid:β-cyclodextrin stability is independent of pigment structure.

    PubMed

    Fernández-García, Elisabet; Pérez-Gálvez, Antonio

    2017-04-15

    Carotenoids refer to a wide class of lipophilic pigments synthesized by plants, exert photoprotective and antioxidant properties that are lost upon carotenoid degradation. Their inclusion into hydrophilic host-molecules could improve their stability. Cyclodextrins, provide a hydrophobic cavity in the core of their structure while the outer configuration is suitable with aqueous environments. Carotenoids can accommodate into the hydrophobic core of cyclodextrins and therefore, they are protected from exogenous stress. Literature reported that carotenoid structure could modulate stability of the complexes, however no conclusions can be drawn as the studies performed so far were not completely analogous. We describe the synthesis of several carotenoids/β-CDs inclusion complexes and provide experimental evidences that β-CDs inclusion renders these compounds more stability towards the oxidizing agents (2,2'-azobis, 2-methylpropionamidine dihydrochloride and hydrogen peroxide). Esterified carotenoids were also used in this work to screen the influence of this particular structural configuration of xanthophylls against oxidation.

  16. Biotechnological production of value-added carotenoids from microalgae

    PubMed Central

    Wichuk, Kristine; Brynjólfsson, Sigurður; Fu, Weiqi

    2014-01-01

    We recently evaluated the relationship between abiotic environmental stresses and lutein biosynthesis in the green microalga Dunaliella salina and suggested a rational design of stress-driven adaptive evolution experiments for carotenoids production in microalgae. Here, we summarize our recent findings regarding the biotechnological production of carotenoids from microalgae and outline emerging technology in this field. Carotenoid metabolic pathways are characterized in several representative algal species as they pave the way for biotechnology development. The adaptive evolution strategy is highlighted in connection with enhanced growth rate and carotenoid metabolism. In addition, available genetic modification tools are described, with emphasis on model species. A brief discussion on the role of lights as limiting factors in carotenoid production in microalgae is also included. Overall, our analysis suggests that light-driven metabolism and the photosynthetic efficiency of microalgae in photobioreactors are the main bottlenecks in enhancing biotechnological potential of carotenoid production from microalgae. PMID:24691165

  17. Carotenoid extraction methods: A review of recent developments.

    PubMed

    Saini, Ramesh Kumar; Keum, Young-Soo

    2018-02-01

    The versatile use of carotenoids in feed, food, cosmetic and pharmaceutical industries has emphasized the optimization of extraction methods to obtain the highest recovery. The choice of method for carotenoid extraction from food matrices is crucial, owing to the presence of diverse carotenoids with varied levels of polarity, and the presence of various physical and chemical barriers in the food matrices. This review highlights the theoretical aspects and recent developments of various conventional and nonconventional methods used for the extraction of carotenoids, including ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE). Recent applications of non-toxic and environmentally safe solvents (green solvents) and ionic liquids (IL) for carotenoid extraction are also described. Additionally, future research challenges in the context of carotenoids extractions are also identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Bioaccessibility of carotenoids from Chlorella vulgaris and Chlamydomonas reinhardtii.

    PubMed

    Gille, Andrea; Trautmann, Andreas; Posten, Clemens; Briviba, Karlis

    2015-08-01

    Microalgae can contribute to a balanced diet because of their composition. Beside numerous essential nutrients, carotenoids are in the focus for food applications. The bioavailability of carotenoids from photoautotrophic-cultivated Chlorella vulgaris (C. vulgaris) and Chlamydomonas reinhardtii (C. reinhardtii) was compared. An in vitro digestion model was used to investigate carotenoid bioaccessibility. Furthermore, the effect of sonication on bioaccessibility was assessed. Lutein was the main carotenoid in both species. C. reinhardtii showed higher amounts of lutein and β-carotene than C. vulgaris. In contrast to C. reinhardtii, no β-carotene and only 7% of lutein were bioaccessible in nonsonicated C. vulgaris. Sonication increased the bioaccessibility of carotenoids from C. vulgaris to a level comparable with C. reinhardtii (β-carotene: ≥ 10%; lutein: ≥ 15%). Thus, C. reinhardtii represents a good carotenoid source for potential use in foods without processing, while the application of processing methods, like sonication, is necessary for C. vulgaris.

  19. Marine carotenoids: Bioactivities and potential benefits to human health.

    PubMed

    Chuyen, Hoang Van; Eun, Jong-Bang

    2017-08-13

    Among natural pigments, carotenoids play important roles in physiological functions. The characteristics of carotenoids and their effects on human health have been reported for a long time, but most studies have focused on carotenoids from vegetables, fruits, and other parts of higher plants. Few reports are available on carotenoids from marine sources, such as seaweeds, microalgae, and marine animals, which have attracted attention in recent decades. Hundreds of carotenoids have been identified and isolated from marine organisms and their beneficial physiological functions, such as anticancer, antiobesity, antidiabetic, anti-inflammatory, and cardioprotective activities have been reported. The purpose of this review is to discuss the literature on the beneficial bioactivities of some of the most abundant marine carotenoids, including fucoxanthin, astaxanthin, cantaxanthin, peridinin, fucoxanthinol, and halocynthiaxanthin.

  20. Compact multichannel imaging laser radar receiver

    NASA Astrophysics Data System (ADS)

    Burns, Hoyt N.; Yun, Steven T.; Keltos, Michael L.; Kimmet, James S.

    1999-05-01

    Direct detection imaging Laser Radar (LADAR) produces 3-dimensional range imagery that can be processed to provide target acquisition and precision aimpoint definition in real time. This paper describes the current status of the Parallel Multichannel Imaging LADAR Receiver (PMR), developed under an SBIR Phase II program by the Air Force Research Laboratory, Munitions Directorate (AFRL/MN). The heart of the PMR is the Multichannel Optical Receiver Photonic Hybrid (MORPH), a high performance 16-channel LADAR receiver card which includes fiber-coupled detectors, pulse discrimination, and range counting circuitry on a 3 X 5 inch circuit card. The MORPH provides high downrange resolution (3 inches), multiple-hit (8 per channel) range and reflectance data for each detector. Silicon (Si) and indium gallium arsenide (InGaAs) pin diode or avalanche photodiode (APD) detectors are supported. The modular PMR uses an array of MORPH circuit cards to form a compact multichannel imaging LADAR receiver with any multiple of 16 channels. A 32-channel system measures 3 X 5 X 1.4 inches and weighs 1 lb. A prototype PMR system is currently undergoing field-testing. This paper focuses on field test results and applications of the PMR technology.

  1. Multichannel algorithms for seismic reflectivity inversion

    NASA Astrophysics Data System (ADS)

    Wang, Ruo; Wang, Yanghua

    2017-02-01

    Seismic reflectivity inversion is a deconvolution process for quantitatively extracting the reflectivity series and depicting the layered subsurface structure. The conventional method is a single channel inversion and cannot clearly characterise stratified structures, especially from seismic data with low signal-to-noise ratio. Because it is implemented on a trace-by-trace basis, the continuity along reflections in the original seismic data is deteriorated in the inversion results. We propose here multichannel inversion algorithms that apply the information of adjacent traces during seismic reflectivity inversion. Explicitly, we incorporate a spatial prediction filter into the conventional Cauchy-constrained inversion method. We verify the validity and feasibility of the method using field data experiments and find an improved lateral continuity and clearer structures achieved by the multichannel algorithms. Finally, we compare the performance of three multichannel algorithms and merit the effectiveness based on the lateral coherency and structure characterisation of the inverted reflectivity profiles, and the residual energy of the seismic data at the same time.

  2. Raman spectra of carotenoids in natural products

    NASA Astrophysics Data System (ADS)

    Withnall, Robert; Chowdhry, Babur Z.; Silver, Jack; Edwards, Howell G. M.; de Oliveira, Luiz F. C.

    2003-08-01

    Resonance Raman spectra of naturally occurring carotenoids have been obtained from nautilus, periwinkle ( Littorina littorea) and clam shells under 514.5 nm excitation and these spectra are compared with the resonance Raman spectra obtained in situ from tomatoes, carrots, red peppers and saffron. The tomatoes, carrots and red peppers gave rise to resonance Raman spectra exhibiting a ν1 band at ca. 1520 cm -1, in keeping with its assignment to carotenoids with ca. nine conjugated carboncarbon double bonds in their main chains, whereas the resonance Raman spectrum of saffron showed a ν1 band at 1537 cm -1 which can be assigned to crocetin, having seven conjugated carboncarbon double bonds. A correlation between ν1 wavenumber location and effective conjugated chain length has been used to interpret the data obtained from the shells, and the wavenumber position (1522 cm -1) of the ν1 band of the carotenoid in the orange clam shell suggests that it contains nine conjugated double bonds in the main chain. However, the black periwinkle and nautilus shells exhibit ν1 bands at 1504 and 1496 cm -1, respectively. On the basis of the correlation between ν1 wavenumber location and effective conjugated chain length, this indicates that they contain carotenoids with longer conjugated chains, the former having ca. 11 double bonds and the latter ca. 13 or even more. Raman spectra of the nautilus, periwinkle and clam shells also exhibited a strong band at 1085 cm -1 and a doublet with components at 701 and 705 cm -1, which can be assigned to biogenic calcium carbonate in the aragonite crystallographic form.

  3. Optimal nutrition: vitamin A and the carotenoids.

    PubMed

    Thurnham, D I; Northrop-Clewes, C A

    1999-05-01

    There are two major dietary sources of vitamin A: easily absorbed retinyl palmitate in foods of animal origin, and poorly bioavailable carotenoids from plant foods. Plasma retinol is tightly controlled, probably by regulation of retinol-binding protein (RBP) formation in the liver, and only hormonal factors (e.g. oral contraceptives) and infection will alter the homeostasis. Delivery of retinol to the tissues is facilitated by the RBP-retinol complex; however, there is evidence that this mechanism can be bypassed when very high doses of vitamin A are given. Some retinyl ester may be released to tissues from chylomicrons when the latter bind to tissue lipoprotein receptors during their passage from the gut to the liver following a meal. High-dose vitamin A therapy is a means of rapidly improving vitamin A status in persons with sub-optimal vitamin A nutrition but there are dangers of toxic symptoms (e.g. teratogenicity) from excess vitamin A usage. Evidence is presented to suggest that the plasma retinol: RBP may be a guide to optimal vitamin A status, since values less than one frequently occur in less-developed countries and during infection. In contrast to plasma retinol, plasma carotenoids reflect the dietary intake of plant foods. However, absorption is limited by poor bioavailability and a saturable uptake mechanism in competition with other phytochemicals. Recent work on bioavailability suggests that the calculation of plant food vitamin A activity should be re-examined. Illness has little influence on plasma levels except by suppressing appetite. Carotenoids are generally regarded as non-toxic yet intervention studies with beta-carotene in smokers have been associated with increased lung cancer and heart disease. Some carotenoids are important as vitamin A precursors, but the physiological importance of their antioxidant properties is not known and consequently the amount needed for optimal nutrition is uncertain.

  4. Comparison of Methodologies of Activation Barrier Measurements for Reactions with Deactivation

    DOE PAGES

    Xie, Zhenhua; Yan, Binhang; Zhang, Li; ...

    2017-01-25

    In this work, methodologies of activation barrier measurements for reactions with deactivation were theoretically analyzed. Reforming of ethane with CO2 was introduced as an example for reactions with deactivation to experimentally evaluate these methodologies. Both the theoretical and experimental results showed that due to catalyst deactivation, the conventional method would inevitably lead to a much lower activation barrier, compared to the intrinsic value, even though heat and mass transport limitations were excluded. In this work, an optimal method was identified in order to provide a reliable and efficient activation barrier measurement for reactions with deactivation.

  5. Solid-state enzyme deactivation in air and in organic solvents

    SciTech Connect

    Toscano, G.; Pirozzi, D.; Maremonti, M.; Greco, G. Jr. . Dipartimento di Ingegneria Chimica)

    1994-09-05

    Thermal deactivation of solid-state acid phosphatase is analyzed, both in the presence and in the absence of organic solvents. The thermal deactivation profile departs from first order kinetics and shows an unusual, temperature-dependent, asymptotic value of residual activity. The process is described by a phenomenological equation, whose theoretical implications are also discussed. The total amount of buffer salts in the enzyme powder dramatically affects enzyme stability in the range 70 to 105 C. The higher salt/protein ratio increases the rate of thermal deactivation. The deactivation rate is virtually unaffected by the presence of organic solvents, independent of their hydrophilicity.

  6. Chlorophyll and carotenoid pigments of prochloron (prochlorophyta)

    NASA Technical Reports Server (NTRS)

    Paerl, H. W.; Lewin, R. A.; Cheng, L.

    1983-01-01

    High-performance liquid chromatography (HPLC) with a gradient-elution technique was utilized to separate and quantify chlorophylls a and b as well as major carotenoid pigments present in freeze-dried preprations of prochloron-didemnid associations and in Prochloron cells separated from host colonies. Results confirm earlier spectrophotometric evidence for both chlorophylls a and b in this prokaryote. Chlorophyll a:b ratios range from 4.14 to 19.71; generally good agreement was found between ratios determined in isolated cell preprations and in symbiotic colonies (in hospite). These values are 1.5 to 5-fold higher than ratios determined in a variety of eukaryotic green plants. The carotenoids in Prochloron are quantitatively and qualitatively similar to those found in various freshwater and marine blue-green algae (cyanopbytes) from high-light environments. However, Prochloron differs from cyanophytes by the absence of myxoxanthophyll and related glycosidic carotenoids. It pigment characteristics are considered sufficiently different from those of cyanophytes to justify its assignment to a separate algal division.

  7. Chlorophyll and carotenoid pigments of prochloron (prochlorophyta)

    NASA Technical Reports Server (NTRS)

    Paerl, H. W.; Lewin, R. A.; Cheng, L.

    1983-01-01

    High-performance liquid chromatography (HPLC) with a gradient-elution technique was utilized to separate and quantify chlorophylls a and b as well as major carotenoid pigments present in freeze-dried preprations of prochloron-didemnid associations and in Prochloron cells separated from host colonies. Results confirm earlier spectrophotometric evidence for both chlorophylls a and b in this prokaryote. Chlorophyll a:b ratios range from 4.14 to 19.71; generally good agreement was found between ratios determined in isolated cell preprations and in symbiotic colonies (in hospite). These values are 1.5 to 5-fold higher than ratios determined in a variety of eukaryotic green plants. The carotenoids in Prochloron are quantitatively and qualitatively similar to those found in various freshwater and marine blue-green algae (cyanopbytes) from high-light environments. However, Prochloron differs from cyanophytes by the absence of myxoxanthophyll and related glycosidic carotenoids. It pigment characteristics are considered sufficiently different from those of cyanophytes to justify its assignment to a separate algal division.

  8. A Unified Picture of S* in Carotenoids

    PubMed Central

    2016-01-01

    In π-conjugated chain molecules such as carotenoids, coupling between electronic and vibrational degrees of freedom is of central importance. It governs both dynamic and static properties, such as the time scales of excited state relaxation as well as absorption spectra. In this work, we treat vibronic dynamics in carotenoids on four electronic states (|S0⟩, |S1⟩, |S2⟩, and |Sn⟩) in a physically rigorous framework. This model explains all features previously associated with the intensely debated S* state. Besides successfully fitting transient absorption data of a zeaxanthin homologue, this model also accounts for previous results from global target analysis and chain length-dependent studies. Additionally, we are able to incorporate findings from pump-deplete-probe experiments, which were incompatible to any pre-existing model. Thus, we present the first comprehensive and unified interpretation of S*-related features, explaining them by vibronic transitions on either S1, S0, or both, depending on the chain length of the investigated carotenoid. PMID:27509302

  9. [Carotenoid pigments: structural and physicochemical considerations].

    PubMed

    Meléndez-Martínez, Antonio J; Vicario, Isabel M; Heredia, Francisco J

    2007-06-01

    Carotenoid are ubiquitous compounds serving a series of functions that make them special. Thus, they are regarded as essential compounds for life mainly due to the different roles they perform in photosynthesis as we currently know it. For many years, the nutritional relevance ot carotenoids was due to some of them exhibiting vitamin A activity, although the interest in these pigments has expanded dramatically in the last years owing to a large variety of surveys that seem to indicate that they are antioxidant and may be beneficial for the prevention of several chronic non-transmissible human diseases, albeit there is some controversy in this regard. In any case, it is clear that the different functions and effects attributed to these isoprenoids stem from their physical and chemical properties, the latter being due to their chemical structure. Due to the diverse benefitial actions carotenoids are responsible for and, above all, to their nutritional importance, the main objective of this review is to describe such features, whose knowledge is indispensable to have a holistic view of the different roles they play and for the design of new studies.

  10. Insights into the deactivation of 5-bromouracil after ultraviolet excitation.

    PubMed

    Peccati, Francesca; Mai, Sebastian; González, Leticia

    2017-04-28

    5-Bromouracil is a nucleobase analogue that can replace thymine in DNA strands and acts as a strong radiosensitizer, with potential applications in molecular biology and cancer therapy. Here, the deactivation of 5-bromouracil after ultraviolet irradiation is investigated in the singlet and triplet manifold by accurate quantum chemistry calculations and non-adiabatic dynamics simulations. It is found that, after irradiation to the bright ππ* state, three main relaxation pathways are, in principle, possible: relaxation back to the ground state, intersystem crossing (ISC) and C-Br photodissociation. Based on accurate MS-CASPT2 optimizations, we propose that ground-state relaxation should be the predominant deactivation pathway in the gas phase. We then employ different electronic structure methods to assess their suitability to carry out excited-state dynamics simulations. MRCIS (multi-reference configuration interaction including single excitations) was used in surface hopping simulations to compute the ultrafast ISC dynamics, which mostly involves the (1)nOπ* and (3)ππ* states.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'. © 2017 The Author(s).

  11. Insights into the deactivation of 5-bromouracil after ultraviolet excitation

    NASA Astrophysics Data System (ADS)

    Peccati, Francesca; Mai, Sebastian; González, Leticia

    2017-03-01

    5-Bromouracil is a nucleobase analogue that can replace thymine in DNA strands and acts as a strong radiosensitizer, with potential applications in molecular biology and cancer therapy. Here, the deactivation of 5-bromouracil after ultraviolet irradiation is investigated in the singlet and triplet manifold by accurate quantum chemistry calculations and non-adiabatic dynamics simulations. It is found that, after irradiation to the bright ππ* state, three main relaxation pathways are, in principle, possible: relaxation back to the ground state, intersystem crossing (ISC) and C-Br photodissociation. Based on accurate MS-CASPT2 optimizations, we propose that ground-state relaxation should be the predominant deactivation pathway in the gas phase. We then employ different electronic structure methods to assess their suitability to carry out excited-state dynamics simulations. MRCIS (multi-reference configuration interaction including single excitations) was used in surface hopping simulations to compute the ultrafast ISC dynamics, which mostly involves the 1nOπ* and 3ππ* states. This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

  12. Routes for deactivation of different autothermal reforming catalysts

    NASA Astrophysics Data System (ADS)

    Pasel, Joachim; Wohlrab, Sebastian; Kreft, Stefanie; Rotov, Mikhail; Löhken, Katrin; Peters, Ralf; Stolten, Detlef

    2016-09-01

    Fuel cell systems with integrated autothermal reforming units require active and robust catalysts for H2 production. In pursuit of this, an experimental screening of catalysts utilized in the autothermal reforming of commercial diesel fuels is performed. The catalysts incorporate a monolithic cordierite substrate, an oxide support (γ-Al2O3, La-Al2O3, CeO2, Gd-CeO2, ZrO2, Y-ZrO2) and Rh as the active phase. Experiments are run by widely varying the O2/C and H2O/C molar ratios at different gas hourly space velocities. In most cases, this provokes accelerated catalyst deactivation and permits an informative comparison of the catalysts. Fresh and aged catalysts are characterized by temperature-programmed methods, thermogravimetry and transmission electron microscopy to find correlations with catalytic activity and stability. Using this approach, routes for catalyst deactivation are identified, together with causes of different catalytic activities. Suitable reaction conditions can be derived from our results for the operation of reactors for autothermal reforming at steady-state and under transient reaction conditions, which helps improve the efficiency and the stability of fuel cell systems.

  13. Universal and reusable virus deactivation system for respiratory protection

    PubMed Central

    Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick

    2017-01-01

    Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases. PMID:28051158

  14. Deactivation of ceria-based SOFC anodes in methanol

    NASA Astrophysics Data System (ADS)

    Kim, Taeyoon; Ahn, Kipyung; Vohs, John M.; Gorte, Raymond J.

    The performance and stability of Cu-ceria-YSZ (yttria-stabilized zirconia) and carbon-ceria-YSZ, solid-oxide-fuel-cell (SOFC) anodes were examined in neat (100%) methanol at 973 K and compared to the performance of the same anodes in dry H 2. The presence of Cu catalyzed the decomposition of methanol, so that the initial performance of cells with Cu-ceria-YSZ anodes was similar to CO and H 2. However, with carbon-ceria-YSZ anodes, the open-circuit voltage was significantly higher and the reaction over-potential significantly lower in methanol than in H 2, suggesting that methanol is a more effective reductant of the anode three-phase boundary region. Carbon-ceria-YSZ anodes were found to undergo rapid and irreversible deactivation in methanol. Steady-state rates of methanol decomposition over ceria-YSZ were found to undergo a similar deactivation as the carbon-ceria anodes. Although no evidence for carbon deposition was observed with methanol at 973 K, the addition of steam was found to partially stabilize both anode and catalyst performance. Scanning electron microscopy (SEM) of ceria particles in YSZ showed a large change in the morphology of the ceria particles when the samples were heated in methanol, while negligible changes were observed when heating in H 2. It is suggested that the results with methanol can be explained as resulting from the very low P(O 2) that is effectively produced by having methanol in contact with ceria.

  15. Universal and reusable virus deactivation system for respiratory protection

    NASA Astrophysics Data System (ADS)

    Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick

    2017-01-01

    Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases.

  16. Investigation of deactivation thermodynamics of lipase immobilized on polymeric carrier.

    PubMed

    Badgujar, Kirtikumar C; Bhanage, Bhalchandra M

    2017-05-01

    In the present work, we have investigated biochemical thermo-kinetic stability of lipases immobilized on a biocompatible polymeric material. Immobilization of lipase Candida rugosa (CRL) was carried out on biocompatible blend of poly vinyl alcohol (PVA) and chitosan (CHY) support via entrapment and glutardehyde (Glu) cross-linking method to produce PVA:CHY:CRL and PVA:CHY:Glu:CRL as robust biocatalyst. These immobilized lipases were characterized by various physico-biochemical characterization techniques. Later on, thermal and solvent stability of polymer immobilized lipase was determined in term of half-life time (t 0.5), D values, enthalpy (ΔH°), entropy (ΔS°), and free energy (ΔG°) of deactivation at different temperatures and in various solvents. The thermodynamic deactivation stability trend was found as: cross-linked lipase CRL > entrapped lipase CRL > free lipase CRL. Moreover, kinetic parameters, such as K m, V max, and catalytic efficiency, were also determined to understand the kinetic features. The polymer immobilized enzyme was reused to investigate the economic viability of the developed biocatalyst.

  17. Helium Pot System for Maintaining Sample Temperature after Cryocooler Deactivation

    SciTech Connect

    Haid, B J

    2005-01-26

    A system for maintaining a sample at a constant temperature below 10K after deactivating the cooling source is demonstrated. In this system, the cooling source is a GM cryocooler that is joined with the sample through an adaptor that consists of a helium pot and a resistive medium. Upon deactivating the cryocooler, the power applied to a heater located on the sample side of the resistive medium is decreased gradually to maintain an appropriate temperature rise across the resistive medium as the helium pot warms. The temperature is held constant in this manner without the use of solid or liquid cryogens and without mechanically disconnecting the sample from the cooler. Shutting off the cryocooler significantly reduces sample motion that results from vibration and expansion/contraction of the cold head housing. The reduction in motion permits certain processes that are very sensitive to sample position stability, but are not performed throughout the duration that the sample is at low-temperature. An apparatus was constructed to demonstrate this technique using a 4K GM cryocooler. Experimental and theoretical predictions indicate that when the helium pot is pressurized to the working pressure of the cryocooler's helium supply, a sample with continuous heat dissipation of several-hundred milliwatts can be maintained at 7K for several minutes when using an extension that increases the cold head length by less than 50%.

  18. Activation-deactivation of self-healing in supramolecular rubbers

    NASA Astrophysics Data System (ADS)

    Corte, Laurent; Maes, Florine; Montarnal, Damien; Cantournet, Sabine; Tournilhac, Francois; Leibler, Ludwik; Mines-Paristech Cnrs (Umr7633) Team; Espci-Paristech Cnrs (Umr7167) Team

    2011-03-01

    Self-healing materials have the ability to restore autonomously their structural integrity after damage. Such a remarkable property was obtained recently in supramolecular rubbers formed by a network of small molecules associated via hydrogen bonds. Here we explore this self-healing through an original tack experiment where two parts of supramolecular rubber are brought into contact and then separated. These experiments reveal that a strong self-healing ability is activated by damage even though the surfaces of a molded part are weakly self-adhesive. In our testing conditions, a five minute contact between crack faces is sufficient to recover most mechanical properties of the bulk while days are required to obtain such adhesion levels with melt-pressed surfaces. We show that the deactivation of this self-healing ability seems unexpectedly slow as compared to the predicted dynamics of supramolecular networks. Fracture faces stored apart at room temperature still self-heal after days but are fully deactivated within hours by annealing. Combining these results with microstructural observations gives us a deeper insight into the mechanisms involved in this self-healing process.

  19. The macrophage in HIV-1 infection: from activation to deactivation?

    PubMed

    Herbein, Georges; Varin, Audrey

    2010-04-09

    Macrophages play a crucial role in innate and adaptative immunity in response to microorganisms and are an important cellular target during HIV-1 infection. Recently, the heterogeneity of the macrophage population has been highlighted. Classically activated or type 1 macrophages (M1) induced in particular by IFN-gamma display a pro-inflammatory profile. The alternatively activated or type 2 macrophages (M2) induced by Th-2 cytokines, such as IL-4 and IL-13 express anti-inflammatory and tissue repair properties. Finally IL-10 has been described as the prototypic cytokine involved in the deactivation of macrophages (dM). Since the capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines, this review shows how modulation of macrophage activation by cytokines impacts the capacity to support productive HIV-1 infection. Based on the activation status of macrophages we propose a model starting with M1 classically activated macrophages with accelerated formation of viral reservoirs in a context of Th1 and proinflammatory cytokines. Then IL-4/IL-13 alternatively activated M2 macrophages will enter into the game that will stop the expansion of the HIV-1 reservoir. Finally IL-10 deactivation of macrophages will lead to immune failure observed at the very late stages of the HIV-1 disease.

  20. Development of a rapid, simple assay of plasma total carotenoids

    PubMed Central

    2012-01-01

    Background Plasma total carotenoids can be used as an indicator of risk of chronic disease. Laboratory analysis of individual carotenoids by high performance liquid chromatography (HPLC) is time consuming, expensive, and not amenable to use beyond a research laboratory. The aim of this research is to establish a rapid, simple, and inexpensive spectrophotometric assay of plasma total carotenoids that has a very strong correlation with HPLC carotenoid profile analysis. Results Plasma total carotenoids from 29 volunteers ranged in concentration from 1.2 to 7.4 μM, as analyzed by HPLC. A linear correlation was found between the absorbance at 448 nm of an alcohol / heptane extract of the plasma and plasma total carotenoids analyzed by HPLC, with a Pearson correlation coefficient of 0.989. The average coefficient of variation for the spectrophotometric assay was 6.5% for the plasma samples. The limit of detection was about 0.3 μM and was linear up to about 34 μM without dilution. Correlations between the integrals of the absorption spectra in the range of carotenoid absorption and total plasma carotenoid concentration gave similar results to the absorbance correlation. Spectrophotometric assay results also agreed with the calculated expected absorbance based on published extinction coefficients for the individual carotenoids, with a Pearson correlation coefficient of 0.988. Conclusion The spectrophotometric assay of total carotenoids strongly correlated with HPLC analysis of carotenoids of the same plasma samples and expected absorbance values based on extinction coefficients. This rapid, simple, inexpensive assay, when coupled with the carotenoid health index, may be useful for nutrition intervention studies, population cohort studies, and public health interventions. PMID:23006902

  1. Carotenoid Antenna Binding and Function in Retinal Proteins

    DTIC Science & Technology

    2012-08-13

    REPORT Carotenoid antenna binding and function in retinal proteins 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: Xanthorhodopsin, a proton pump from the...eubacterium Salinibacter ruber, is a unique dual chromophore system that contains, in addition to retinal, the carotenoid salinixanthin as a light... carotenoid ring near the retinal ring. Substitution of the small glycine with bulky tryptophan in this site eliminates binding. The second factor is the 4

  2. The carotenoid dioxygenase gene family in maize, sorghum, and rice

    PubMed Central

    Vallabhaneni, Ratnakar; Bradbury, Louis M. T.; Wurtzel, Eleanore T.

    2010-01-01

    Carotenoids and their apocarotenoid derivatives play essential physiological and developmental roles and provide plants tolerance to a variety of stresses. Carotenoid cleavage dioxygenases mediate the degradation of carotenoids to apocarotenoids. A better understanding of biosynthesis vs. degradation could be useful for controlling carotenoid levels leading to improved plant fitness and/or enhanced content of nutritionally valuable carotenoids. The Poaceae (grass) plant family contains many crops of agronomic value. Therefore this study focused on characterizing the carotenoid dioxygenase gene family in the grass species maize, rice, and sorghum with comparison made to newly identified gene families in two non-seed plants as well as an alga and previously identified eudicot genes. Genome analysis was used to map grass genes encoding the carotenoid dioxygenases to chromosome locations. Sequences of encoded proteins were phylogenetically compared. CCD8b was identified as a new class of cleavage dioxygenases that may play a specialized role in apocarotenoid biogenesis. A simple PCR assay was developed to measure CCD1 gene copy number which is known to vary in maize. Using a panel of maize inbred lines varying in carotenoid content, linear regression analysis revealed a statistically significant negative correlation between copy number of CCD1 and carotenoid content, an effect likely mediated through the resulting elevated levels of endosperm CCD1 transcripts in high copy number lines. The PCR assay adds to a growing toolbox for metabolic engineering of maize endosperm carotenoids. This new tool can be used to select maize lines that are less likely to promote endosperm carotenoid degradation, thus predicting optimal results in metabolic engineering of endosperm provitamin A and/or nonprovitamin A carotenoids. PMID:20670614

  3. ProCarDB: a database of bacterial carotenoids.

    PubMed

    Nupur, L N U; Vats, Asheema; Dhanda, Sandeep Kumar; Raghava, Gajendra P S; Pinnaka, Anil Kumar; Kumar, Ashwani

    2016-05-26

    Carotenoids have important functions in bacteria, ranging from harvesting light energy to neutralizing oxidants and acting as virulence factors. However, information pertaining to the carotenoids is scattered throughout the literature. Furthermore, information about the genes/proteins involved in the biosynthesis of carotenoids has tremendously increased in the post-genomic era. A web server providing the information about microbial carotenoids in a structured manner is required and will be a valuable resource for the scientific community working with microbial carotenoids. Here, we have created a manually curated, open access, comprehensive compilation of bacterial carotenoids named as ProCarDB- Prokaryotic Carotenoid Database. ProCarDB includes 304 unique carotenoids arising from 50 biosynthetic pathways distributed among 611 prokaryotes. ProCarDB provides important information on carotenoids, such as 2D and 3D structures, molecular weight, molecular formula, SMILES, InChI, InChIKey, IUPAC name, KEGG Id, PubChem Id, and ChEBI Id. The database also provides NMR data, UV-vis absorption data, IR data, MS data and HPLC data that play key roles in the identification of carotenoids. An important feature of this database is the extension of biosynthetic pathways from the literature and through the presence of the genes/enzymes in different organisms. The information contained in the database was mined from published literature and databases such as KEGG, PubChem, ChEBI, LipidBank, LPSN, and Uniprot. The database integrates user-friendly browsing and searching with carotenoid analysis tools to help the user. We believe that this database will serve as a major information centre for researchers working on bacterial carotenoids.

  4. Ultrastructural deposition forms and bioaccessibility of carotenoids and carotenoid esters from goji berries (Lycium barbarum L.).

    PubMed

    Hempel, Judith; Schädle, Christopher N; Sprenger, Jasmin; Heller, Annerose; Carle, Reinhold; Schweiggert, Ralf M

    2017-03-01

    Goji berries (Lycium barbarum L.) have been known to contain strikingly high levels of zeaxanthin, while the physical deposition form and bioaccessibility of the latter was yet unknown. In the present study, we associated ripening-induced modifications in the profile of carotenoids with fundamental changes of the deposition state of carotenoids in goji berries. Unripe fruit contained common chloroplast-specific carotenoids being protein-bound within chloroplastidal thylakoids. The subsequent ripening-induced transformation of chloroplasts to tubular chromoplasts was accompanied by an accumulation of up to 36mg/100g FW zeaxanthin dipalmitate and further minor xanthophyll esters, prevailing in a presumably liquid-crystalline state within the nano-scaled chromoplast tubules. The in vitro digestion unraveled the enhanced liberation and bioaccessibility of zeaxanthin from these tubular aggregates in goji berries as compared to protein-complexed lutein from spinach. Goji berries therefore might represent a more potent source of macular pigments than green leafy vegetables like spinach.

  5. Effects of carotenoids from lucerne, marigold and tomato on egg yolk pigmentation and carotenoid composition.

    PubMed

    Karadas, F; Grammenidis, E; Surai, P F; Acamovic, T; Sparks, N H C

    2006-10-01

    1. The effects of various sources of natural carotenoids (Px alfalfa concentrate, tomato powder and marigold extract) as feed additives in quail diets on egg yolk pigmentation and carotenoid composition were investigated. 2. Adult Japanese quail were fed one of 5 different diets for 23 d: three diets each contained Px alfalfa concentrate (PX) or tomato powder (TP) or marigold extract (MG), one diet contained marigold extract and tomato powder (MG + TP) and a control diet (wheat/barley based) was low in carotenoid. All products were added at a rate of 2%, apart from marigold extract which was added at a rate of 0.2%. 3. Visual assessment of yolk colour (Roche colour fan) showed a stabilised yolk colour of 1.6, 7.7, 8.5, 8.8 and 10.6 for the control, PX, TP, MG and MG + TP treatments, respectively. 4. The total carotenoid concentration of the egg yolks were 2.2, 22.4, 4.1, 39.0 and 37.7 microg/g for the experimental groups fed the following diets: control, PX, TP, MG and MG + TP, respectively. Deposition of retinol, alpha-tocopherol and gamma-tocopherol in the egg yolk was unaffected by treatments. 5. Lutein was shown to be the major carotenoid in the egg yolk, comprising 1.65, 17.97, 2.03, 31.14 and 28.57 microg/g in control, PX, TP, MG and MG + TP, respectively. Inclusion of TP in the quail diet resulted in lycopene transfer to the egg. 6. It was concluded that, in comparison with the control group, there was an increase in the yolk concentrations of lutein, zeaxanthin, lycopene and beta-carotene in eggs produced by female quail fed diets supplemented with natural carotenoids.

  6. A Carotenoid Health Index Based on Plasma Carotenoids and Health Outcomes

    PubMed Central

    Donaldson, Michael S.

    2011-01-01

    While there have been many studies on health outcomes that have included measurements of plasma carotenoids, this data has not been reviewed and assembled into a useful form. In this review sixty-two studies of plasma carotenoids and health outcomes, mostly prospective cohort studies or population-based case-control studies, are analyzed together to establish a carotenoid health index. Five cutoff points are established across the percentiles of carotenoid concentrations in populations, from the tenth to ninetieth percentile. The cutoff points (mean ± standard error of the mean) are 1.11 ± 0.08, 1.47 ± 0.08, 1.89 ± 0.08, 2.52 ± 0.13, and 3.07 ± 0.20 µM. For all cause mortality there seems to be a low threshold effect with protection above every cutoff point but the lowest. But for metabolic syndrome and cancer outcomes there tends to be significant positive health outcomes only above the higher cutoff points, perhaps as a triage effect. Based on this data a carotenoid health index is proposed with risk categories as follows: very high risk: <1 µM, high risk: 1-1.5 µM, moderate risk: 1.5-2.5 µM, low risk: 2.5-4 µM, and very low risk: >4 µM. Over 95 percent of the USA population falls into the moderate or high risk category of the carotenoid health index. PMID:22292108

  7. Specific Appetite for Carotenoids in a Colorful Bird

    PubMed Central

    Senar, Juan Carlos; Møller, Anders Pape; Ruiz, Iker; Negro, Juan José; Broggi, Juli; Hohtola, Esa

    2010-01-01

    Background Since carotenoids have physiological functions necessary for maintaining health, individuals should be selected to actively seek and develop a specific appetite for these compounds. Methodology/Principal Findings Great tits Parus major in a diet choice experiment, both in captivity and the field, preferred carotenoid-enriched diets to control diets. The food items did not differ in any other aspects measured besides carotenoid content. Conclusions/Significance Specific appetite for carotenoids is here demonstrated for the first time, placing these compounds on a par with essential nutrients as sodium or calcium. PMID:20502717

  8. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress.

    PubMed

    Amengual, Jaume; Lobo, Glenn P; Golczak, Marcin; Li, Hua Nan M; Klimova, Tatyana; Hoppel, Charles L; Wyss, Adrian; Palczewski, Krzysztof; von Lintig, Johannes

    2011-03-01

    Carotenoids are the precursors for vitamin A and are proposed to prevent oxidative damage to cells. Mammalian genomes encode a family of structurally related nonheme iron oxygenases that modify double bonds of these compounds by oxidative cleavage and cis-to-trans isomerization. The roles of the family members BCMO1 and RPE65 for vitamin A production and vision have been well established. Surprisingly, we found that the third family member, β,β-carotene-9',10'-oxygenase (BCDO2), is a mitochondrial carotenoid-oxygenase with broad substrate specificity. In BCDO2-deficient mice, carotenoid homeostasis was abrogated, and carotenoids accumulated in several tissues. In hepatic mitochondria, accumulated carotenoids induced key markers of mitochondrial dysfunction, such as manganese superoxide dismutase (9-fold), and reduced rates of ADP-dependent respiration by 30%. This impairment was associated with an 8- to 9-fold induction of phosphor-MAP kinase and phosphor-AKT, markers of cell signaling pathways related to oxidative stress and disease. Administration of carotenoids to human HepG2 cells depolarized mitochondrial membranes and resulted in the production of reactive oxygen species. Thus, our studies in BCDO2-deficient mice and human cell cultures indicate that carotenoids can impair respiration and induce oxidative stress. Mammalian cells thus express a mitochondrial carotenoid-oxygenase that degrades carotenoids to protect these vital organelles.

  9. Involvement of Ethylene in Phytochrome-mediated Carotenoid Synthesis 1

    PubMed Central

    Kang, Bin G.; Burg, Stanley P.

    1972-01-01

    Accumulation of carotenoid pigments in the shoot apex of etiolated pea (Pisum sativum cv. Alaska) seedlings is completely prevented by ethylene. Under certain conditions carotenoid synthesis is normally controlled by endogenously produced ethylene. The gas completely inhibits carotenoid synthesis induced either by continuous white light or brief illumination with red light, but only partially inhibits light-induced chlorophyll formation. Far red illumination followed by red illumination reverses the action of red light on carotenoid synthesis. Red light-induced carotenogenesis is partly or wholly caused by phytochrome-mediated inhibition of ethylene biosynthesis. PMID:16658014

  10. Accumulation of Carotenoids and Expression of Carotenoid Biosynthetic Genes during Maturation in Citrus Fruit1

    PubMed Central

    Kato, Masaya; Ikoma, Yoshinori; Matsumoto, Hikaru; Sugiura, Minoru; Hyodo, Hiroshi; Yano, Masamichi

    2004-01-01

    The relationship between carotenoid accumulation and the expression of carotenoid biosynthetic genes during fruit maturation was investigated in three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). We cloned the cDNAs for phytoene synthase (CitPSY), phytoene desaturase (CitPDS), ζ-carotene (car) desaturase (CitZDS), carotenoid isomerase (CitCRTISO), lycopene β-cyclase (CitLCYb), β-ring hydroxylase (CitHYb), zeaxanthin (zea) epoxidase (CitZEP), and lycopene ε-cyclase (CitLCYe) from Satsuma mandarin, which shared high identities in nucleotide sequences with Valencia orange, Lisbon lemon, and other plant species. With the transition of peel color from green to orange, the change from β,ε-carotenoid (α-car and lutein) accumulation to β,β-carotenoid (β-car, β-cryptoxanthin, zea, and violaxanthin) accumulation was observed in the flavedos of Satsuma mandarin and Valencia orange, accompanying the disappearance of CitLCYe transcripts and the increase in CitLCYb transcripts. Even in green fruit, high levels of β,ε-carotenoids and CitLCYe transcripts were not observed in the juice sacs. As fruit maturation progressed in Satsuma mandarin and Valencia orange, a simultaneous increase in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb, CitHYb, and CitZEP) led to massive β,β-xanthophyll (β-cryptoxanthin, zea, and violaxanthin) accumulation in both the flavedo and juice sacs. The gene expression of CitCRTISO was kept low or decreased in the flavedo during massive β,β-xanthophyll accumulation. In the flavedo of Lisbon lemon and Satsuma mandarin, massive accumulation of phytoene was observed with a decrease in the transcript level for CitPDS. Thus, the carotenoid accumulation during citrus fruit maturation was highly regulated by the coordination of the expression among carotenoid biosynthetic genes. In this paper, the mechanism leading to diversity in

  11. Directed evolution of carotenoid synthases for the production of unnatural carotenoids.

    PubMed

    Furubayashi, Maiko; Umeno, Daisuke

    2012-01-01

    Directed evolution is a well-established strategy to confer novel catalytic functions to the enzymes. Thanks to the relative ease of establishing color screening, carotenogenic enzymes can be rapidly evolved in the laboratory for novel functions. The combinatorial usages of the evolvants result in the creation of diverse set of novel, sometimes unnatural carotenoids. This chapter describes the directed evolution of diapophytoene (C(30) carotenoid) synthase CrtM to function in the foreign C(40) pathway, and the use of the CrtM variants thus obtained for the production of novel backbone structures.

  12. Pump-probe and pump-deplete-probe spectroscopies on carotenoids with N =9-15 conjugated bonds

    NASA Astrophysics Data System (ADS)

    Buckup, Tiago; Savolainen, Janne; Wohlleben, Wendel; Herek, Jennifer L.; Hashimoto, Hideki; Correia, Ricardo R. B.; Motzkus, Marcus

    2006-11-01

    A series of all-trans-carotenoids with N =9, 13, and 15 conjugated bonds has been studied by pump-probe and pump-deplete-probe spectroscopies to obtain a systematic analysis of the energy flow between the different electronic states. The ultrafast dynamics in the carotenoids are initialized by excitation to the S2 state and subsequently manipulated by an additional depletion pulse in the near-IR spectral range. The changes in the dynamics after depletion of the excited state population allowed differentiation of the excited state absorption into two components, a major one corresponding to the well known S1 state and the small contribution on the red wing of the S0-S2 absorption band originating from the hot ground state. We found no evidence for an additional electronically excited state, usually called S*. Instead, a deactivation mechanism that includes the hot ground state supports the observed results nicely in the framework of a simple three state model (S2, S1, and S0).

  13. Carotenoids and Carotenoid Esters of Red and Yellow Physalis (Physalis alkekengi L. and P. pubescens L.) Fruits and Calyces.

    PubMed

    Wen, Xin; Hempel, Judith; Schweiggert, Ralf M; Ni, Yuanying; Carle, Reinhold

    2017-08-02

    Carotenoid profiles of fruits and calyces of red (Physalis alkekengi L.) and yellow (P. pubescens L.) Physalis were characterized by HPLC-DAD-APCI-MS(n). Altogether 69 carotenoids were detected in red Physalis, thereof, 45 were identified. In yellow Physalis, 40 carotenoids were detected and 33 were identified. Zeaxanthin esters with various fatty acids were found to be the most abundant carotenoids in red Physalis, accounting for 51-63% of total carotenoids, followed by β-cryptoxanthin esters (16-24%). In yellow Physalis, mainly free carotenoids such as lutein and β-carotene were found. Total carotenoid contents ranged between 19.8 and 21.6 mg/100 g fresh red Physalis fruits and 1.28-1.38 mg/100 g fresh yellow Physalis fruits, demonstrating that Physalis fruits are rich sources of dietary carotenoids. Yellow Physalis calyces contained only 153-306 μg carotenoids/g dry weight, while those of red Physalis contained substantially higher amounts (14.6-17.6 mg/g dry weight), thus possibly exhibiting great potential as a natural source for commercial zeaxanthin extraction.

  14. Health Effects of Carotenoids during Pregnancy and Lactation

    PubMed Central

    Zielińska, Monika A.; Wesołowska, Aleksandra; Pawlus, Beata; Hamułka, Jadwiga

    2017-01-01

    Adequate nutrition is particularly important during pregnancy since it is needed not only for maintaining the health of the mother, but also determines the course of pregnancy and its outcome, fetus development as well as the child’s health after birth and during the later period of life. Data coming from epidemiological and interventions studies support the observation that carotenoids intake provide positive health effects in adults and the elderly population. These health effects are the result of their antioxidant and anti-inflammatory properties. Recent studies have also demonstrated the significant role of carotenoids during pregnancy and infancy. Some studies indicate a correlation between carotenoid status and lower risk of pregnancy pathologies induced by intensified oxidative stress, but results of these investigations are equivocal. Carotenoids have been well studied in relation to their beneficial role in the prevention of preeclampsia. It is currently hypothesized that carotenoids can play an important role in the prevention of preterm birth and intrauterine growth restriction. Carotenoid status in the newborn depends on the nutritional status of the mother, but little is known about the transfer of carotenoids from the mother to the fetus. Carotenoids are among the few nutrients found in breast milk, in which the levels are determined by the mother’s diet. Nutritional status of the newborn directly depends on its diet. Both mix feeding and artificial feeding may cause depletion of carotenoids since infant formulas contain only trace amounts of these compounds. Carotenoids, particularly lutein and zeaxanthin play a significant role in the development of vision and nervous system (among others, they are important for the development of retina as well as energy metabolism and brain electrical activity). Furthermore, more scientific evidence is emerging on the role of carotenoids in the prevention of disorders affecting preterm infants, who are

  15. Carotenoids in Staple Cereals: Metabolism, Regulation, and Genetic Manipulation

    PubMed Central

    Zhai, Shengnan; Xia, Xianchun; He, Zhonghu

    2016-01-01

    Carotenoids play a critical role in animal and human health. Animals and humans are unable to synthesize carotenoids de novo, and therefore rely upon diet as sources of these compounds. However, major staple cereals often contain only small amounts of carotenoids in their grains. Consequently, there is considerable interest in genetic manipulation of carotenoid content in cereal grain. In this review, we focus on carotenoid metabolism and regulation in non-green plant tissues, as well as genetic manipulation in staple cereals such as rice, maize, and wheat. Significant progress has been made in three aspects: (1) seven carotenogenes play vital roles in carotenoid regulation in non-green plant tissues, including 1-deoxyxylulose-5-phosphate synthase influencing isoprenoid precursor supply, phytoene synthase, β-cyclase, and ε-cyclase controlling biosynthesis, 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase and carotenoid cleavage dioxygenases responsible for degradation, and orange gene conditioning sequestration sink; (2) provitamin A-biofortified crops, such as rice and maize, were developed by either metabolic engineering or marker-assisted breeding; (3) quantitative trait loci for carotenoid content on chromosomes 3B, 7A, and 7B were consistently identified, eight carotenogenes including 23 loci were detected, and 10 gene-specific markers for carotenoid accumulation were developed and applied in wheat improvement. A comprehensive and deeper understanding of the regulatory mechanisms of carotenoid metabolism in crops will be beneficial in improving our precision in improving carotenoid contents. Genomic selection and gene editing are emerging as transformative technologies for provitamin A biofortification. PMID:27559339

  16. Attention, Emotion, and Deactivation of Default Activity in Inferior Medial Prefrontal Cortex

    ERIC Educational Resources Information Center

    Geday, Jacob; Gjedde, Albert

    2009-01-01

    Attention deactivates the inferior medial prefrontal cortex (IMPC), but it is uncertain if emotions can attenuate this deactivation. To test the extent to which common emotions interfere with attention, we measured changes of a blood flow index of brain activity in key areas of the IMPC with positron emission tomography (PET) of labeled water…

  17. Attention, Emotion, and Deactivation of Default Activity in Inferior Medial Prefrontal Cortex

    ERIC Educational Resources Information Center

    Geday, Jacob; Gjedde, Albert

    2009-01-01

    Attention deactivates the inferior medial prefrontal cortex (IMPC), but it is uncertain if emotions can attenuate this deactivation. To test the extent to which common emotions interfere with attention, we measured changes of a blood flow index of brain activity in key areas of the IMPC with positron emission tomography (PET) of labeled water…

  18. Collective Resistance in Microbial Communities by Intracellular Antibiotic Deactivation.

    PubMed

    Sorg, Robin A; Lin, Leo; van Doorn, G Sander; Sorg, Moritz; Olson, Joshua; Nizet, Victor; Veening, Jan-Willem

    2016-12-01

    The structure and composition of bacterial communities can compromise antibiotic efficacy. For example, the secretion of β-lactamase by individual bacteria provides passive resistance for all residents within a polymicrobial environment. Here, we uncover that collective resistance can also develop via intracellular antibiotic deactivation. Real-time luminescence measurements and single-cell analysis demonstrate that the opportunistic human pathogen Streptococcus pneumoniae grows in medium supplemented with chloramphenicol (Cm) when resistant bacteria expressing Cm acetyltransferase (CAT) are present. We show that CAT processes Cm intracellularly but not extracellularly. In a mouse pneumonia model, more susceptible pneumococci survive Cm treatment when coinfected with a CAT-expressing strain. Mathematical modeling predicts that stable coexistence is only possible when antibiotic resistance comes at a fitness cost. Strikingly, CAT-expressing pneumococci in mouse lungs were outcompeted by susceptible cells even during Cm treatment. Our results highlight the importance of the microbial context during infectious disease as a potential complicating factor to antibiotic therapy.

  19. Revealing Deactivation Pathways Hidden in Time-Resolved Photoelectron Spectra

    NASA Astrophysics Data System (ADS)

    Ruckenbauer, Matthias; Mai, Sebastian; Marquetand, Philipp; González, Leticia

    2016-10-01

    Time-resolved photoelectron spectroscopy is commonly employed with the intention to monitor electronic excited-state dynamics occurring in a neutral molecule. With the help of theory, we show that when excited-state processes occur on similar time scales the different relaxation pathways are completely obscured in the total photoionization signal recorded in the experiment. Using non-adiabatic molecular dynamics and Dyson norms, we calculate the photoionization signal of cytosine and disentangle the transient contributions originating from the different deactivation pathways of its tautomers. In the simulations, the total signal from the relevant keto and enol tautomers can be decomposed into contributions either from the neutral electronic state populations or from the distinct mechanistic pathways across the multiple potential surfaces. The lifetimes corresponding to these contributions cannot be extracted from the experiment, thereby illustrating that new experimental setups are necessary to unravel the intricate non-adiabatic pathways occurring in polyatomic molecules after irradiation by light.

  20. DEACTIVATION AND DECOMMISSIONING PLANNING AND ANALYSIS WITH GEOGRAPHIC INFORMATION SYSTEMS

    SciTech Connect

    Bollinger, J; William Austin, W; Larry Koffman, L

    2007-09-17

    From the mid-1950's through the 1980's, the U.S. Department of Energy's Savannah River Site produced nuclear materials for the weapons stockpile, for medical and industrial applications, and for space exploration. Although SRS has a continuing defense-related mission, the overall site mission is now oriented toward environmental restoration and management of legacy chemical and nuclear waste. With the change in mission, SRS no longer has a need for much of the infrastructure developed to support the weapons program. This excess infrastructure, which includes over 1000 facilities, will be decommissioned and demolished over the forthcoming years. Dispositioning facilities for decommissioning and deactivation requires significant resources to determine hazards, structure type, and a rough-order-of-magnitude estimate for the decommissioning and demolition cost. Geographic information systems (GIS) technology was used to help manage the process of dispositioning infrastructure and for reporting the future status of impacted facilities.

  1. Reversible Deactivation of Enzymes by Redox-Responsive Nanogel Carriers.

    PubMed

    Peng, Huan; Rübsam, Kristin; Jakob, Felix; Pazdzior, Patrizia; Schwaneberg, Ulrich; Pich, Andrij

    2016-11-01

    Novel redox-responsive polymeric nanogels that allow highly efficient enzyme encapsulation and reversible modulation of enzyme activity are developed. The nanogel synthesis and encapsulation of enzyme are performed simultaneously via in situ crosslinking of pyridyldisulfide-functionalized water-soluble reactive copolymers, which are synthesized via reversible addition-fragmentation chain transfer copolymerization. Obtained nanogels with loaded cellulase demonstrate very good colloidal stability in aqueous solutions. The enzymatic activity of cellulase is greatly reduced when encapsulated in the nanogels and rapidly recovered in 10 × 10(-3) m dithiothreitol solution. Fluorescence resonance energy transfer (FRET)-based experiments indicate that the recovered enzymatic activity is mainly ascribed to the release of the enzyme due to the degradation of the disulfide crosslinking network after addition of dithiothreitol (DTT), instead of the enhanced substrate transport rate. The developed enzyme immobilization method opens new possibilities for reversible activation/deactivation of enzymes and opens up new directions for targeted protein therapy and biotechnology applications.

  2. Exploration of Excited State Deactivation Pathways of Adenine Monohydrates.

    PubMed

    Chaiwongwattana, Sermsiri; Sapunar, Marin; Ponzi, Aurora; Decleva, Piero; Došlić, Nađa

    2015-10-29

    Binding of a single water molecule has a dramatic effect on the excited state lifetime of adenine. Here we report a joint nonadiabatic dynamics and reaction paths study aimed at understanding the sub-100 fs lifetime of adenine in the monohydrates. Our nonadiabatic dynamics simulations, performed using the ADC(2) electronic structure method, show a shortening of the excited state lifetime in the monohydrates with respect to bare adenine. However, the computed lifetimes were found to be significantly longer that the observed one. By comparing the reaction pathways of several excited state deactivation processes in adenine and adenine monohydrates, we show that electron-driven proton transfer from water to nitrogen atom N3 of the adenine ring may be the process responsible for the observed ultrafast decay. The inaccessibility of the electron-driven proton transfer pathway to trajectory-based nonadiabatic dynamics simulation is discussed.

  3. A critical evaluation of migraine trigger site deactivation surgery.

    PubMed

    Mathew, Paul G

    2014-01-01

    Migraine headache trigger site deactivation surgery is a term that encompasses 4 different surgical procedures that are performed based on headache onset location for the preventative treatment of migraine headaches. Multiple studies have demonstrated some efficacy of these procedures, but closer evaluation of the methodology of these studies reveals major flaws in study design. In this article, the author provides an overview of the procedures and presurgical screening tools, as well as a critical evaluation of 2 of the major studies that have been published. In addition, the author provides his opinion on future study designs that may help to better determine the potential efficacy of these experimental procedures and potential headache subtypes (contact point headache, supraorbital neuralgia, and occipital neuralgia) that may respond to peripheral decompression surgery. © 2013 American Headache Society.

  4. Revealing Deactivation Pathways Hidden in Time-Resolved Photoelectron Spectra

    PubMed Central

    Ruckenbauer, Matthias; Mai, Sebastian; Marquetand, Philipp; González, Leticia

    2016-01-01

    Time-resolved photoelectron spectroscopy is commonly employed with the intention to monitor electronic excited-state dynamics occurring in a neutral molecule. With the help of theory, we show that when excited-state processes occur on similar time scales the different relaxation pathways are completely obscured in the total photoionization signal recorded in the experiment. Using non-adiabatic molecular dynamics and Dyson norms, we calculate the photoionization signal of cytosine and disentangle the transient contributions originating from the different deactivation pathways of its tautomers. In the simulations, the total signal from the relevant keto and enol tautomers can be decomposed into contributions either from the neutral electronic state populations or from the distinct mechanistic pathways across the multiple potential surfaces. The lifetimes corresponding to these contributions cannot be extracted from the experiment, thereby illustrating that new experimental setups are necessary to unravel the intricate non-adiabatic pathways occurring in polyatomic molecules after irradiation by light. PMID:27762396

  5. Epidemics with temporary link deactivation in scale-free networks

    PubMed Central

    Shkarayev, Maxim S.; Tunc, Ilker; Shaw, Leah B.

    2014-01-01

    During an epidemic, people may adapt or alter their social contacts to avoid infection. Various adaptation mechanisms have been studied previously. Recently, a new adaptation mechanism was presented in [1], where susceptible nodes temporarily deactivate their links to infected neighbors and reactivate when their neighbors recover. Considering the same adaptation mechanism on a scale-free network, we find that the topology of the subnetwork consisting of active links is fundamentally different from the original network topology. We predict the scaling exponent of the active degree distribution and derive mean-field equations by using improved moment closure approximations based on the conditional distribution of active degree given the total degree. These mean field equations show better agreement with numerical simulation results than the standard mean field equations based on a homogeneity assumption. PMID:25419231

  6. Commercial experience with facility deactivation to safe storage

    SciTech Connect

    Sype, T.T.; Fischer, S.R.; Lee, J.H. Jr.; Sanchez, L.C.; Ottinger, C.A.; Pirtle, G.J.

    1995-09-01

    The Department of Energy (DOE) has shutdown many production reactors; the Department has begun a major effort to also shutdown a wide variety of other nuclear facilities. Because so many facilities are being closed, it is necessary to place many of them into a safe- storage status, i.e., deactivation, before conducting decommissioning- for perhaps as long as 20 years. The challenge is to achieve this safe-storage condition in a cost-effective manner while remaining in compliance with applicable regulations. The DOE Office of Environmental Management, Office of Transition and Management, commissioned a lessons-learned study of commercial experience with safe storage and decommissioning. Although the majority of the commercial experience has been with reactors, many of the lessons learned presented in this document can provide insight into transitioning challenges that Will be faced by the DOE weapons complex.

  7. Heterologous carotenoid-biosynthetic enzymes: functional complementation and effects on carotenoid profiles in Escherichia coli.

    PubMed

    Song, Gyu Hyeon; Kim, Se Hyeuk; Choi, Bo Hyun; Han, Se Jong; Lee, Pyung Cheon

    2013-01-01

    A limited number of carotenoid pathway genes from microbial sources have been studied for analyzing the pathway complementation in the heterologous host Escherichia coli. In order to systematically investigate the functionality of carotenoid pathway enzymes in E. coli, the pathway genes of carotenogenic microorganisms (Brevibacterium linens, Corynebacterium glutamicum, Rhodobacter sphaeroides, Rhodobacter capsulatus, Rhodopirellula baltica, and Pantoea ananatis) were modified to form synthetic expression modules and then were complemented with Pantoea agglomerans pathway enzymes (CrtE, CrtB, CrtI, CrtY, and CrtZ). The carotenogenic pathway enzymes in the synthetic modules showed unusual activities when complemented with E. coli. For example, the expression of heterologous CrtEs of B. linens, C. glutamicum, and R. baltica influenced P. agglomerans CrtI to convert its substrate phytoene into a rare product-3,4,3',4'-tetradehydrolycopene-along with lycopene, which was an expected product, indicating that CrtE, the first enzyme in the carotenoid biosynthesis pathway, can influence carotenoid profiles. In addition, CrtIs of R. sphaeroides and R. capsulatus converted phytoene into an unusual lycopene as well as into neurosporene. Thus, this study shows that the functional complementation of pathway enzymes from different sources is a useful methodology for diversifying biosynthesis as nature does.

  8. Heterologous Carotenoid-Biosynthetic Enzymes: Functional Complementation and Effects on Carotenoid Profiles in Escherichia coli

    PubMed Central

    Song, Gyu Hyeon; Kim, Se Hyeuk; Choi, Bo Hyun; Han, Se Jong

    2013-01-01

    A limited number of carotenoid pathway genes from microbial sources have been studied for analyzing the pathway complementation in the heterologous host Escherichia coli. In order to systematically investigate the functionality of carotenoid pathway enzymes in E. coli, the pathway genes of carotenogenic microorganisms (Brevibacterium linens, Corynebacterium glutamicum, Rhodobacter sphaeroides, Rhodobacter capsulatus, Rhodopirellula baltica, and Pantoea ananatis) were modified to form synthetic expression modules and then were complemented with Pantoea agglomerans pathway enzymes (CrtE, CrtB, CrtI, CrtY, and CrtZ). The carotenogenic pathway enzymes in the synthetic modules showed unusual activities when complemented with E. coli. For example, the expression of heterologous CrtEs of B. linens, C. glutamicum, and R. baltica influenced P. agglomerans CrtI to convert its substrate phytoene into a rare product—3,4,3′,4′-tetradehydrolycopene—along with lycopene, which was an expected product, indicating that CrtE, the first enzyme in the carotenoid biosynthesis pathway, can influence carotenoid profiles. In addition, CrtIs of R. sphaeroides and R. capsulatus converted phytoene into an unusual lycopene as well as into neurosporene. Thus, this study shows that the functional complementation of pathway enzymes from different sources is a useful methodology for diversifying biosynthesis as nature does. PMID:23144136

  9. Expression of carotenoid biosynthetic pathway genes and changes in carotenoids during ripening in tomato (Lycopersicon esculentum).

    PubMed

    Namitha, Kanakapura Krishnamurthy; Archana, Surya Narayana; Negi, Pradeep Singh

    2011-04-01

    To study the expression pattern of carotenoid biosynthetic pathway genes, changes in their expression at different stages of maturity in tomato fruit (cv. Arka Ahuti) were investigated. The genes regulating carotenoid production were quantified by a dot blot method using a DIG (dioxigenin) labelling and detection kit. The results revealed that there was an increase in the levels of upstream genes of the carotenoid biosynthetic pathway such as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), 4-hydroxy-3-methyl-but-2-enyl diphosphate reductase (Lyt B), phytoene synthase (PSY), phytoene desaturase (PDS) and ζ-carotene desaturase (ZDS) by 2-4 fold at the breaker stage as compared to leaf. The lycopene and β-carotene content was analyzed by HPLC at different stages of maturity. The lycopene (15.33 ± 0.24 mg per 100 g) and β-carotene (10.37 ± 0.46 mg per 100 g) content were found to be highest at 5 days post-breaker and 10 days post-breaker stage, respectively. The lycopene accumulation pattern also coincided with the color values at different stages of maturity. These studies may provide insight into devising gene-based strategies for enhancing carotenoid accumulation in tomato fruits.

  10. Comparative in vitro bioaccessibility of carotenoids from relevant contributors to carotenoid intake.

    PubMed

    Granado-Lorencio, Fernando; Olmedilla-Alonso, Begoña; Herrero-Barbudo, Carmen; Pérez-Sacristan, Belén; Blanco-Navarro, Inmaculada; Blazquez-García, Silvia

    2007-07-25

    To compare the in vitro bioaccessibility of lutein, zeaxanthin, beta-cryptoxanthin, lycopene, and alpha-and beta-carotenes from relevant dietary contributors, a gastrointestinal model was used to assess the stability, isomerization, carotenol ester hydrolysis, and micellarization. Salivar, gastric, duodenal, and micellar phases were extracted, with and without saponification, and analyzed by using a quality-controlled HPLC method. The stability of carotenoids under digestion conditions was >75%, regardless of the food analyzed, whereas micellarization ranged from 5 to 100%, depending on the carotenoid and the food. cis-Isomers were maintained in processed foods, but increased in fresh foods. Xanthophyll ester hydrolysis was incomplete (<40%), and both free and ester forms were incorporated into supernatants, regardless of the xanthophyll involved and the food assessed. In vitro bioaccesibility varies widely both for different carotenoids in a given food and for a given carotenoid in different foods. Although in vitro bioaccesibility may not be enough to predict the in vivo bioavailability, it may be relevant for the food industry and for food-based dietary guidelines.

  11. A molecular genetic analysis of carotenoid biosynthesis and the effects of carotenoid mutations on other photosynthetic genes in Rhodobacter capsulatus

    SciTech Connect

    Armstrong, G.A.

    1989-04-01

    The nine known R. capsulatus carotenoid genes are contained within the 46 kilobase (kb) photosynthesis gene cluster. An 11 kb subcluster containing eight of these genes has been cloned and its nucleotide sequence determined. A new gene, crtK, has been located in the middle of the subcluster. The carotenoid gene cluster contains sequences homologous to Escherichia coli ..omega../sup 70/ promoters, rho-independent transcription terminators, and prokaryotic transcriptional factor binding sites. The phenotypes and genotypes of ten transposon Tn5.7 insertion mutations within the carotenoid gene cluster have been analyzed, by characterization of the carotenoids accumulated and high resolution mapping of the Tn5.7 insertions. The enzymatic blockages in previously uncharacterized early carotenoid mutants have been determined using a new in vitro synthesis system, suggesting specific roles for the CrtB and CrtE gene products. The expression of six of the eight carotenoid genes in the cluster is induced upon the shift from dark chemoheterotrophic to anaerobic photosynthetic growth. The magnitude of the induction is equivalent to that of genes encoding structural photosynthesis polypeptides, although the carotenoid genes are induced earlier after the growth shift. Different means of regulating photosynthesis genes in R. capsulatus are discussed, and a rationale for the temporal pattern of expression of the carotenoid genes during photosynthetic adaptation is presented. Comparison of the deduced amino acid sequences of the two dehydrogenases of the R. capsulatus carotenoid biosynthesis pathway reveals two regions of strong similarity. The effect of carotenoid mutations on the photosynthetic phenotype has been studied by examining growth rates, pigments, pigment-protein complexes and gene expression for a complete set of carotenoid mutants. 161 refs.

  12. The effects of dietary carotenoid supplementation and retinal carotenoid accumulation on vision-mediated foraging in the house finch.

    PubMed

    Toomey, Matthew B; McGraw, Kevin J

    2011-01-01

    For many bird species, vision is the primary sensory modality used to locate and assess food items. The health and spectral sensitivities of the avian visual system are influenced by diet-derived carotenoid pigments that accumulate in the retina. Among wild House Finches (Carpodacus mexicanus), we have found that retinal carotenoid accumulation varies significantly among individuals and is related to dietary carotenoid intake. If diet-induced changes in retinal carotenoid accumulation alter spectral sensitivity, then they have the potential to affect visually mediated foraging performance. In two experiments, we measured foraging performance of house finches with dietarily manipulated retinal carotenoid levels. We tested each bird's ability to extract visually contrasting food items from a matrix of inedible distracters under high-contrast (full) and dimmer low-contrast (red-filtered) lighting conditions. In experiment one, zeaxanthin-supplemented birds had significantly increased retinal carotenoid levels, but declined in foraging performance in the high-contrast condition relative to astaxanthin-supplemented birds that showed no change in retinal carotenoid accumulation. In experiments one and two combined, we found that retinal carotenoid concentrations predicted relative foraging performance in the low- vs. high-contrast light conditions in a curvilinear pattern. Performance was positively correlated with retinal carotenoid accumulation among birds with low to medium levels of accumulation (∼0.5-1.5 µg/retina), but declined among birds with very high levels (>2.0 µg/retina). Our results suggest that carotenoid-mediated spectral filtering enhances color discrimination, but that this improvement is traded off against a reduction in sensitivity that can compromise visual discrimination. Thus, retinal carotenoid levels may be optimized to meet the visual demands of specific behavioral tasks and light environments.

  13. The Effects of Dietary Carotenoid Supplementation and Retinal Carotenoid Accumulation on Vision-Mediated Foraging in the House Finch

    PubMed Central

    Toomey, Matthew B.; McGraw, Kevin J.

    2011-01-01

    Background For many bird species, vision is the primary sensory modality used to locate and assess food items. The health and spectral sensitivities of the avian visual system are influenced by diet-derived carotenoid pigments that accumulate in the retina. Among wild House Finches (Carpodacus mexicanus), we have found that retinal carotenoid accumulation varies significantly among individuals and is related to dietary carotenoid intake. If diet-induced changes in retinal carotenoid accumulation alter spectral sensitivity, then they have the potential to affect visually mediated foraging performance. Methodology/Principal Findings In two experiments, we measured foraging performance of house finches with dietarily manipulated retinal carotenoid levels. We tested each bird's ability to extract visually contrasting food items from a matrix of inedible distracters under high-contrast (full) and dimmer low-contrast (red-filtered) lighting conditions. In experiment one, zeaxanthin-supplemented birds had significantly increased retinal carotenoid levels, but declined in foraging performance in the high-contrast condition relative to astaxanthin-supplemented birds that showed no change in retinal carotenoid accumulation. In experiments one and two combined, we found that retinal carotenoid concentrations predicted relative foraging performance in the low- vs. high-contrast light conditions in a curvilinear pattern. Performance was positively correlated with retinal carotenoid accumulation among birds with low to medium levels of accumulation (∼0.5–1.5 µg/retina), but declined among birds with very high levels (>2.0 µg/retina). Conclusion/Significance Our results suggest that carotenoid-mediated spectral filtering enhances color discrimination, but that this improvement is traded off against a reduction in sensitivity that can compromise visual discrimination. Thus, retinal carotenoid levels may be optimized to meet the visual demands of specific behavioral tasks and

  14. A multi-channel near infrared spectroradiometer

    NASA Astrophysics Data System (ADS)

    Joseph, G. B.; Biddles, B. J.; D'Silva, R. A.; Picot, A. J.; Ackerman, M. J.

    1988-01-01

    A multichannel spectroradiometer has been developed by Sira Ltd. for the study of rapidly varying events in the near infrared. The instrument is being used in the examination of gun flashes, rocket motor exhaust efflux analysis and ordnance or pyrotechnic flash studies. The spectral range of about 1.4 to 5.2 microns is covered in two bands with the first order dispersion from a pair of ruled blazed gratings being imaged onto a pair of detector arrays. Data may be logged at a rate of 1000 complete spectra per second.

  15. A multi-channel coronal spectrophotometer.

    NASA Technical Reports Server (NTRS)

    Landman, D. A.; Orrall, F. Q.; Zane, R.

    1973-01-01

    We describe a new multi-channel coronal spectrophotometer system, presently being installed at Mees Solar Observatory, Mount Haleakala, Maui. The apparatus is designed to record and interpret intensities from many sections of the visible and near-visible spectral regions simultaneously, with relatively high spatial and temporal resolution. The detector, a thermoelectrically cooled silicon vidicon camera tube, has its central target area divided into a rectangular array of about 100,000 pixels and is read out in a slow-scan (about 2 sec/frame) mode. Instrument functioning is entirely under PDP 11/45 computer control, and interfacing is via the CAMAC system.

  16. Multichannel correlation recognition method of optical images

    NASA Astrophysics Data System (ADS)

    Wang, Hongxia; He, Junfa; Sun, Honghui

    2000-10-01

    In this paper a multi-channel real-time hybrid joint transform correlator is proposed. In this correlator, the computer control is used to divide the screen into several equal size windows, reference images of the windows are all the same one and object images are adopted from different frames of image sequences by CCD, twice Fourier transforms of every channel images are realized by using hololens array. Areas of LCLV and the output light energy can be used effectively. The correlation performance can be improved.

  17. Multichannel analysis of forward scattered body waves

    NASA Astrophysics Data System (ADS)

    Neal, Scott Lawrence

    We describe a series of innovations which are the basis for a multichannel approach to direct imaging of forward scattered body waves recorded on broadband seismic arrays. The foundation is a method through which the irregularly sampled observed seismograms are interpolated onto an arbitrarily fine grid by means of a convolution between a spatial window function and the actual station locations. The result is a weighted stack which employs all the data to compute a robust and stable multichannel estimate of the wavefield. Deconvolution of the stacked data is shown to be equivalent to a multichannel deconvolution, with spatially variable weights equal to those used in stacking. Application to data from the Lodore array in Colorado and Wyoming shows variations in crustal structure across the array and also images upper mantle discontinuities. A second innovation focuses on the design of deconvolution operators that account for the loss of high frequency components of P-to- S conversions. Two variants are presented, the first increases linearly with P-to-S lag time, the second is based on convolutional quelling and a t* attenuation model. Both methods account for the high attentuation of S waves in the upper mantle. The quelling approach however, has two advantages; it is physically based, and it provides a unified framework for the combination of stacking and deconvolution. We apply multichannel stacking to derive three quantities from the observed data and the associated receiver functions: (1) correlation between stacks of the entire array and local subarray stacks, (2) RMS amplitude of the receiver functions, and (3) Pms-to- P amplitude variations. Application of these attributes to data from recent broadband array deployments in southern Africa, Colorado and Wyoming, and the Tien Shan of central Asia shows these attributes to be highly correlated with the geology of the study areas and to be indicative of major lithospheric discontinuities beneath an array

  18. Asynchronous data readout system for multichannel ASIC

    NASA Astrophysics Data System (ADS)

    Ivanov, P. Y.; Atkin, E. V.

    2016-02-01

    The data readout system of multichannel data-driven ASIC, requiring high-speed (320 Mb/s) output data serialization is described. Its structure, based on a limited number of FIFO blocks, provides a lossless data transfer. The solution has been realized as a separate test IP block in the prototyped 8 channel ASIC, intended for the muon chamber of CBM experiment at FAIR. The block was developed for the UMC 0.18 μm MMRF CMOS process and prototyped via Europractice. Main parameters of the chip are given.

  19. MULTI-CHANNEL PULSE HEIGHT ANALYZER

    DOEpatents

    Boyer, K.; Johnstone, C.W.

    1958-11-25

    An improved multi-channel pulse height analyzer of the type where the device translates the amplitude of each pulse into a time duration electrical quantity which is utilized to control the length of a train of pulses forwarded to a scaler is described. The final state of the scaler for any one train of pulses selects the appropriate channel in a magnetic memory in which an additional count of one is placed. The improvement consists of a storage feature for storing a signal pulse so that in many instances when two signal pulses occur in rapid succession, the second pulse is preserved and processed at a later time.

  20. Multichannel euv spectroscopy of high temperature plasmas

    SciTech Connect

    Fonck, R.J.

    1983-11-01

    Spectroscopy of magnetically confined high temperature plasmas in the visible through x-ray spectral ranges deals primarily with the study of impurity line radiation or continuum radiation. Detailed knowledge of absolute intensities, temporal behavior, and spatial distributions of the emitted radiation is desired. As tokamak facilities become more complex, larger, and less accessible, there has been an increased emphasis on developing new instrumentation to provide such information in a minimum number of discharges. The availability of spatially-imaging detectors for use in the vacuum ultraviolet region (especially the intensified photodiode array) has generated the development of a variety of multichannel spectrometers for applications on tokamak facilities.

  1. Multichannel image regularization using anisotropic geodesic filtering

    SciTech Connect

    Grazzini, Jacopo A

    2010-01-01

    This paper extends a recent image-dependent regularization approach introduced in aiming at edge-preserving smoothing. For that purpose, geodesic distances equipped with a Riemannian metric need to be estimated in local neighbourhoods. By deriving an appropriate metric from the gradient structure tensor, the associated geodesic paths are constrained to follow salient features in images. Following, we design a generalized anisotropic geodesic filter; incorporating not only a measure of the edge strength, like in the original method, but also further directional information about the image structures. The proposed filter is particularly efficient at smoothing heterogeneous areas while preserving relevant structures in multichannel images.

  2. Regulatory control of carotenoid accumulation in winter squash during storage

    USDA-ARS?s Scientific Manuscript database

    Postharvest storage of fruits and vegetables is often required and frequently results in nutritional quality change. In this study, we investigated carotenoid storage plastids, carotenoid content, and its regulation during 3-month storage of winter squash butternut fruits. We showed that storage imp...

  3. Consumption of carotenoid-rich diet improves plasma inflammatory markers

    USDA-ARS?s Scientific Manuscript database

    Multiple studies have investigated the effects of carotenoids on a limited selection of cytokines. However, inflammation is a complex system involving numerous interacting cytokines. In this study, a broad array of 30 cytokines was measured after consumption of low- and high-carotenoid diets. Nine m...

  4. Manipulation of Carotenoid Content in Plants to Improve Human Health.

    PubMed

    Alós, Enriqueta; Rodrigo, Maria Jesús; Zacarias, Lorenzo

    2016-01-01

    Carotenoids are essential components for human nutrition and health, mainly due to their antioxidant and pro-vitamin A activity. Foods with enhanced carotenoid content and composition are essential to ensure carotenoid feasibility in malnourished population of many countries around the world, which is critical to alleviate vitamin A deficiency and other health-related disorders. The pathway of carotenoid biosynthesis is currently well understood, key steps of the pathways in different plant species have been characterized and the corresponding genes identified, as well as other regulatory elements. This enables the manipulation and improvement of carotenoid content and composition in order to control the nutritional value of a number of agronomical important staple crops. Biotechnological and genetic engineering-based strategies to manipulate carotenoid metabolism have been successfully implemented in many crops, with Golden rice as the most relevant example of β-carotene improvement in one of the more widely consumed foods. Conventional breeding strategies have been also adopted in the bio-fortification of carotenoid in staple foods that are highly consumed in developing countries, including maize, cassava and sweet potatoes, to alleviate nutrition-related problems. The objective of the chapter is to summarize major breakthroughs and advances in the enhancement of carotenoid content and composition in agronomical and nutritional important crops, with special emphasis to their potential impact and benefits in human nutrition and health.

  5. Production and conversion of functional carotenoids by bacteria

    USDA-ARS?s Scientific Manuscript database

    Carotenoids are red, orange, and yellow color pigments composed of isoprenyl units. They are well known to have beneficial health effects including anti-oxidant activity, anti-cardiovascular disease, and anti-cancer effects. These carotenoids are mainly synthesized in plants and photosynthetic alg...

  6. Ultrafast time-resolved vibrational spectroscopies of carotenoids in photosynthesis.

    PubMed

    Hashimoto, Hideki; Sugisaki, Mitsuru; Yoshizawa, Masayuki

    2015-01-01

    This review discusses the application of time-resolved vibrational spectroscopies to the studies of carotenoids in photosynthesis. The focus is on the ultrafast time regime and the study of photophysics and photochemistry of carotenoids by femtosecond time-resolved stimulated Raman and four-wave mixing spectroscopies. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.

  7. Non-invasive in vivo measurement of macular carotenoids

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2009-01-01

    A non-invasive in vivo method for assessing macular carotenoids includes performing Optical Coherence Tomography (OCT) on a retina of a subject. A spatial representation of carotenoid levels in the macula based on data from the OCT of the retina can be generated.

  8. Molecular Factors Controlling Photosynthetic Light-Harvesting by Carotenoids

    PubMed Central

    Polívka, Tomáš; Frank, Harry A.

    2010-01-01

    Carotenoids are naturally-occurring pigments that absorb light in the spectral region in which the sun irradiates maximally. These molecules transfer this energy to chlorophylls, initiating the primary photochemical events of photosynthesis. Carotenoids also regulate the flow of energy within the photosynthetic apparatus and protect it from photo-induced damage caused by excess light absorption. To carry out these functions in nature, carotenoids are bound in discrete pigment-protein complexes in close proximity to chlorophylls. A few 3D structures of these carotenoid complexes have been determined by X-ray crystallography. Thus, the stage is set for attempting to correlate the structural information with the spectroscopic properties of carotenoids to understand the molecular mechanism(s) of their function in photosynthetic systems. In this Account, we summarize current spectroscopic data describing the excited state energies and ultrafast dynamics of purified carotenoids in solution and bound in light-harvesting complexes from purple bacteria, marine algae, and green plants. Many of these complexes can be modified using mutagenesis or pigment exchange which facilitates making the correlations between structure and function. We describe the structural and electronic factors controlling the function of carotenoids as energy donors. We also discuss unresolved issues related to the nature of spectroscopically dark excited states, which could play a role in light-harvesting. To illustrate the interplay between structural determinations and spectroscopic investigations that exemplifies work in the field, we describe the spectroscopic properties of four light-harvesting complexes whose structures have been determined to atomic resolution. The first, the LH2 complex from the purple bacterium Rhodopseudomonas acidophila, contains the carotenoid, rhodopin glucoside. The second is the LHCII trimeric complex from higher plants which uses the carotenoids, lutein, neoxanthin

  9. Molecular factors controlling photosynthetic light harvesting by carotenoids.

    PubMed

    Polívka, Tomás; Frank, Harry A

    2010-08-17

    Carotenoids are naturally occurring pigments that absorb light in the spectral region in which the sun irradiates maximally. These molecules transfer this energy to chlorophylls, initiating the primary photochemical events of photosynthesis. Carotenoids also regulate the flow of energy within the photosynthetic apparatus and protect it from photoinduced damage caused by excess light absorption. To carry out these functions in nature, carotenoids are bound in discrete pigment-protein complexes in the proximity of chlorophylls. A few three-dimensional structures of these carotenoid complexes have been determined by X-ray crystallography. Thus, the stage is set for attempting to correlate the structural information with the spectroscopic properties of carotenoids to understand the molecular mechanism(s) of their function in photosynthetic systems. In this Account, we summarize current spectroscopic data describing the excited state energies and ultrafast dynamics of purified carotenoids in solution and bound in light-harvesting complexes from purple bacteria, marine algae, and green plants. Many of these complexes can be modified using mutagenesis or pigment exchange which facilitates the elucidation of correlations between structure and function. We describe the structural and electronic factors controlling the function of carotenoids as energy donors. We also discuss unresolved issues related to the nature of spectroscopically dark excited states, which could play a role in light harvesting. To illustrate the interplay between structural determinations and spectroscopic investigations that exemplifies work in the field, we describe the spectroscopic properties of four light-harvesting complexes whose structures have been determined to atomic resolution. The first, the LH2 complex from the purple bacterium Rhodopseudomonas acidophila, contains the carotenoid rhodopin glucoside. The second is the LHCII trimeric complex from higher plants which uses the carotenoids

  10. Carotenoids and their isomers: color pigments in fruits and vegetables.

    PubMed

    Khoo, Hock-Eng; Prasad, K Nagendra; Kong, Kin-Weng; Jiang, Yueming; Ismail, Amin

    2011-02-18

    Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as 'functional food ingredients'. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

  11. Carotenoid incorporation into microsomes: yields, stability and membrane dynamics

    NASA Astrophysics Data System (ADS)

    Socaciu, Carmen; Jessel, Robert; Diehl, Horst A.

    2000-12-01

    The carotenoids β-carotene (BC), lycopene (LYC), lutein (LUT), zeaxanthin (ZEA), canthaxanthin (CTX) and astaxanthin (ASTA) have been incorporated into pig liver microsomes. Effective incorporation concentrations in the range of about 1-6 nmol/mg microsomal protein were obtained. A stability test at room temperature revealed that after 3 h BC and LYC had decayed totally whereas, gradually, CTX (46%), LUT (21%), ASTA (17%) and ZEA (5%) decayed. Biophysical parameters of the microsomal membrane were changed hardly by the incorporation of carotenoids. A small rigidification may occur. Membrane anisotropy seems to offer only a small tolerance for incorporation of carotenoids and seems to limit the achievable incorporation concentrations of the carotenoids into microsomes. Microsomes instead of liposomes should be preferred as a membrane model to study mutual effects of carotenoids and membrane dynamics.

  12. Marine Carotenoids against Oxidative Stress: Effects on Human Health.

    PubMed

    Gammone, Maria Alessandra; Riccioni, Graziano; D'Orazio, Nicolantonio

    2015-09-30

    Carotenoids are lipid-soluble pigments that are produced in some plants, algae, fungi, and bacterial species, which accounts for their orange and yellow hues. Carotenoids are powerful antioxidants thanks to their ability to quench singlet oxygen, to be oxidized, to be isomerized, and to scavenge free radicals, which plays a crucial role in the etiology of several diseases. Unusual marine environments are associated with a great chemical diversity, resulting in novel bioactive molecules. Thus, marine organisms may represent an important source of novel biologically active substances for the development of therapeutics. In this respect, various novel marine carotenoids have recently been isolated from marine organisms and displayed several utilizations as nutraceuticals and pharmaceuticals. Marine carotenoids (astaxanthin, fucoxanthin, β-carotene, lutein but also the rare siphonaxanthin, sioxanthin, and myxol) have recently shown antioxidant properties in reducing oxidative stress markers. This review aims to describe the role of marine carotenoids against oxidative stress and their potential applications in preventing and treating inflammatory diseases.

  13. Magnetic resonance and optical spectroscopic studies of carotenoids

    SciTech Connect

    Kispert, L.D.

    1991-05-01

    It is our goal to study the role of a host lattice in the formation of radicals and excited singlet and triplet states that are relevant to photosynthesis. Particular emphasis is being placed on determining what is special about carotenoids that natural photosynthetic systems require them as antennae as well as for protection. We are thus manipulating the host matrix so as to understand the carotenoid function (protection, quenching, energy transfer and antenna) and the structure of carotenoid cations. To characterize their properties, we have carried out EPR, ENDOR, optical, molecular orbital and electrochemical studies of carotenoids and carotenoid cations produced chemically, electrochemically, radiolytically (x-ray irradiated freon matrices) and photolytically (solution photolysis by excimer radiation) as a function of the host matrix. 36 refs.

  14. Carotenoids in Marine Invertebrates Living along the Kuroshio Current Coast

    PubMed Central

    Maoka, Takashi; Akimoto, Naoshige; Tsushima, Miyuki; Komemushi, Sadao; Mezaki, Takuma; Iwase, Fumihito; Takahashi, Yoshimitsu; Sameshima, Naomi; Mori, Miho; Sakagami, Yoshikazu

    2011-01-01

    Carotenoids of the corals Acropora japonica, A. secale, and A. hyacinthus, the tridacnid clam Tridacna squamosa, the crown-of-thorns starfish Acanthaster planci, and the small sea snail Drupella fragum were investigated. The corals and the tridacnid clam are filter feeders and are associated with symbiotic zooxanthellae. Peridinin and pyrrhoxanthin, which originated from symbiotic zooxanthellae, were found to be major carotenoids in corals and the tridacnid clam. The crown-of-thorns starfish and the sea snail D. fragum are carnivorous and mainly feed on corals. Peridinin-3-acyl esters were major carotenoids in the sea snail D. fragum. On the other hand, ketocarotenoids such as 7,8-didehydroastaxanthin and astaxanthin were major carotenoids in the crown-of-thorns starfish. Carotenoids found in these marine animals closely reflected not only their metabolism but also their food chains. PMID:21892355

  15. Carotenoids in marine invertebrates living along the Kuroshio current coast.

    PubMed

    Maoka, Takashi; Akimoto, Naoshige; Tsushima, Miyuki; Komemushi, Sadao; Mezaki, Takuma; Iwase, Fumihito; Takahashi, Yoshimitsu; Sameshima, Naomi; Mori, Miho; Sakagami, Yoshikazu

    2011-01-01

    Carotenoids of the corals Acropora japonica, A. secale, and A. hyacinthus, the tridacnid clam Tridacna squamosa, the crown-of-thorns starfish Acanthaster planci, and the small sea snail Drupella fragum were investigated. The corals and the tridacnid clam are filter feeders and are associated with symbiotic zooxanthellae. Peridinin and pyrrhoxanthin, which originated from symbiotic zooxanthellae, were found to be major carotenoids in corals and the tridacnid clam. The crown-of-thorns starfish and the sea snail D. fragum are carnivorous and mainly feed on corals. Peridinin-3-acyl esters were major carotenoids in the sea snail D. fragum. On the other hand, ketocarotenoids such as 7,8-didehydroastaxanthin and astaxanthin were major carotenoids in the crown-of-thorns starfish. Carotenoids found in these marine animals closely reflected not only their metabolism but also their food chains.

  16. Carotenoids Assist in Cyanobacterial Photosystem II Assembly and Function

    PubMed Central

    Zakar, Tomas; Laczko-Dobos, Hajnalka; Toth, Tunde N.; Gombos, Zoltan

    2016-01-01

    Carotenoids (carotenes and xanthophylls) are ubiquitous constituents of living organisms. They are protective agents against oxidative stresses and serve as modulators of membrane microviscosity. As antioxidants they can protect photosynthetic organisms from free radicals like reactive oxygen species that originate from water splitting, the first step of photosynthesis. We summarize the structural and functional roles of carotenoids in connection with cyanobacterial Photosystem II. Although carotenoids are hydrophobic molecules, their complexes with proteins also allow cytoplasmic localization. In cyanobacterial cells such complexes are called orange carotenoid proteins, and they protect Photosystem II and Photosystem I by preventing their overexcitation through phycobilisomes (PBS). Recently it has been observed that carotenoids are not only required for the proper functioning, but also for the structural stability of PBSs. PMID:27014318

  17. Carotenoids and their fatty-acid esters in banana peel.

    PubMed

    Subagio, A; Morita, N; Sawada, S

    1996-12-01

    In relation to banana ripening, banana peel was examined for carotenoid pigments by a combination of alumina column chromatography and high-performance liquid chromatography (HPLC). Carotenoids and their fatty-acid esters were first separated by an alumina column into five fractions, of which each was further subfractionated by HPLC with different kinds of solvent. The carotenoid content of the banana peel was in the range of 3-4 micrograms per gram as lutein equivalent. The ingredients of the carotenoids were ascertained to consist of lutein, beta-carotene, alpha-carotene, violaxanthin, auroxanthin, neoxanthin, isolutein, beta-cryptoxanthin and alpha-cryptoxanthin. Most of the oxygenated carotenoids were found to occur in the esterified form, mainly with myristate, and to a lesser extent with laurate, palmitate or caprate.

  18. Illuminating colors: regulation of carotenoid biosynthesis and accumulation by light.

    PubMed

    Llorente, Briardo; Martinez-Garcia, Jaime F; Stange, Claudia; Rodriguez-Concepcion, Manuel

    2017-06-01

    Light stimulates the biosynthesis of carotenoids and regulates the development of plastid structures to accommodate these photoprotective pigments. Work with Arabidopsis revealed molecular factors coordinating carotenoid biosynthesis and storage with photosynthetic development during deetiolation, when underground seedlings emerge to the light. Some of these factors also adjust carotenoid biosynthesis in response to plant proximity (i.e., shade), a mechanism that was readapted in tomato to monitor fruit ripening progression. While light positively impacts carotenoid production and accumulation in most cases, total carotenoid levels decrease in roots of colored carrot cultivars when illuminated. The recent discovery that such cultivars might be photomorphogenic mutants provides an explanation for this striking phenotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Biosynthesis of Carotenoids in Plants: Enzymes and Color.

    PubMed

    Rosas-Saavedra, Carolina; Stange, Claudia

    2016-01-01

    Carotenoids are the most important biocolor isoprenoids responsible for yellow, orange and red colors found in nature. In plants, they are synthesized in plastids of photosynthetic and sink organs and are essential molecules for photosynthesis, photo-oxidative damage protection and phytohormone synthesis. Carotenoids also play important roles in human health and nutrition acting as vitamin A precursors and antioxidants. Biochemical and biophysical approaches in different plants models have provided significant advances in understanding the structural and functional roles of carotenoids in plants as well as the key points of regulation in their biosynthesis. To date, different plant models have been used to characterize the key genes and their regulation, which has increased the knowledge of the carotenoid metabolic pathway in plants. In this chapter a description of each step in the carotenoid synthesis pathway is presented and discussed.

  20. Physiological stress links parasites to carotenoid-based colour signals.

    PubMed

    Mougeot, F; Martínez-Padilla, J; Bortolotti, G R; Webster, L M I; Piertney, S B

    2010-03-01

    Vertebrates commonly use carotenoid-based traits as social signals. These can reliably advertise current nutritional status and health because carotenoids must be acquired through the diet and their allocation to ornaments is traded-off against other self-maintenance needs. We propose that the coloration more generally reveals an individual's ability to cope with stressful conditions. We tested this idea by manipulating the nematode parasite infection in free-living red grouse (Lagopus lagopus scoticus) and examining the effects on body mass, carotenoid-based coloration of a main social signal and the amount of corticosterone deposited in feathers grown during the experiment. We show that parasites increase stress and reduce carotenoid-based coloration, and that the impact of parasites on coloration was associated with changes in corticosterone, more than changes in body mass. Carotenoid-based coloration appears linked to physiological stress and could therefore reveal an individual's ability to cope with stressors.

  1. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress

    PubMed Central

    Amengual, Jaume; Lobo, Glenn P.; Golczak, Marcin; Li, Hua Nan M.; Klimova, Tatyana; Hoppel, Charles L.; Wyss, Adrian; Palczewski, Krzysztof; von Lintig, Johannes

    2011-01-01

    Carotenoids are the precursors for vitamin A and are proposed to prevent oxidative damage to cells. Mammalian genomes encode a family of structurally related nonheme iron oxygenases that modify double bonds of these compounds by oxidative cleavage and cis-to-trans isomerization. The roles of the family members BCMO1 and RPE65 for vitamin A production and vision have been well established. Surprisingly, we found that the third family member, β,β-carotene-9′,10′-oxygenase (BCDO2), is a mitochondrial carotenoid-oxygenase with broad substrate specificity. In BCDO2-deficient mice, carotenoid homeostasis was abrogated, and carotenoids accumulated in several tissues. In hepatic mitochondria, accumulated carotenoids induced key markers of mitochondrial dysfunction, such as manganese superoxide dismutase (9-fold), and reduced rates of ADP-dependent respiration by 30%. This impairment was associated with an 8- to 9-fold induction of phosphor-MAP kinase and phosphor-AKT, markers of cell signaling pathways related to oxidative stress and disease. Administration of carotenoids to human HepG2 cells depolarized mitochondrial membranes and resulted in the production of reactive oxygen species. Thus, our studies in BCDO2-deficient mice and human cell cultures indicate that carotenoids can impair respiration and induce oxidative stress. Mammalian cells thus express a mitochondrial carotenoid-oxygenase that degrades carotenoids to protect these vital organelles.—Amengual, J., Lobo, G. P., Golczak, M., Li, H. N. M., Klimova, T., Hoppel, C. L., Wyss, A., Palczewski, K., von Lintig, J. A mitochondrial enzyme degrades carotenoids and protects against oxidative stress. PMID:21106934

  2. Carotenoid profiling in tubers of different potato (Solanum sp) cultivars: accumulation of carotenoids mediated by xanthophyll esterification.

    PubMed

    Fernandez-Orozco, Rebeca; Gallardo-Guerrero, Lourdes; Hornero-Méndez, Dámaso

    2013-12-01

    The carotenoid profile of sixty potato cultivars (commercial, bred, old and native cultivars) has been characterised in order to provide information to be used in selective breeding programs directed to improve the nutritional value of this important staple food. Cultivars were segregated into three groups according to the major pigment in the carotenoid profile: violaxanthin (37 cultivars; especially those with higher carotenoid content), lutein (16 cultivars), and neoxanthin (7 cultivars). Other minor carotenoids were antheraxanthin, β-cryptoxanthin and β-carotene, while zeaxanthin was absent in all sample. The total carotenoid content ranged from 50.0 to 1552.0 μg/100 g dry wt, with an average value of about 435.3 μg/100 g dry wt. Sipancachi, Poluya and Chaucha native cultivars showed the highest carotenoid content (1020.0, 1478.2 and 1551.2 μg/100 g dry wt, respectively). Xanthophyll esters were present in most cultivars, mainly as diesterified forms, being observed a direct correlation between the carotenoid content and the esterified fraction, suggesting that the esterification process facilitates the accumulation of these lipophilic compounds within the plastids. Therefore, the presence of xanthophyll esters should be a phenotypic character to be included in the breeding studies, and more efforts should be dedicated to the understanding of the biochemical process leading to this structural modification of carotenoids in plants.

  3. Single v. multiple measures of skin carotenoids by resonance Raman spectroscopy as a biomarker of usual carotenoid status.

    PubMed

    Scarmo, Stephanie; Cartmel, Brenda; Lin, Haiqun; Leffell, David J; Ermakov, Igor V; Gellermann, Werner; Bernstein, Paul S; Mayne, Susan T

    2013-09-14

    Resonance Raman spectroscopy (RRS) is a non-invasive method of assessing carotenoid status in the skin, which has been suggested as an objective indicator of fruit/vegetable intake. The present study assessed agreement and identified predictors of single v. multiple RRS measures of skin carotenoid status. A total of seventy-four participants had their skin carotenoid status measured in the palm of the hand by RRS at six time points over 6 months. Questionnaires were administered to collect information on demographic, lifestyle and dietary data. Mean age of the participants was 36.6 years, 62.2% were female, 83.8% Caucasian and 85.1% were non-smoking at baseline. There was a good agreement between a single measure of skin carotenoids by RRS and multiple measures (weighted κ = 0.80; 95% CI 0.72, 0.88). The same variables were significantly associated with carotenoid status based on single or multiple measures, including a positive association with intake of total carotenoids (P< 0.01) and an inverse association with season of measurement (P≤ 0.05). The exception was recent sun exposure, which emerged as a significant predictor of lower carotenoid status only when using multiple RRS measures (P≤ 0.01). A single RRS measure was reasonably accurate at classifying usual skin carotenoid status. Researchers using RRS may want to take into account other factors that are associated with the biomarker, including season of measurement and recent sun exposure.

  4. Single v. multiple measures of skin carotenoids by resonance Raman spectroscopy as a biomarker of usual carotenoid status

    PubMed Central

    Scarmo, Stephanie; Cartmel, Brenda; Lin, Haiqun; Leffell, David J.; Ermakov, Igor V.; Gellermann, Werner; Bernstein, Paul S.; Mayne, Susan T.

    2013-01-01

    Resonance Raman spectroscopy (RRS) is a non-invasive method of assessing carotenoid status in the skin, which has been suggested as an objective indicator of fruit/vegetable intake. The present study assessed agreement and identified predictors of single v. multiple RRS measures of skin carotenoid status. A total of seventy-four participants had their skin carotenoid status measured in the palm of the hand by RRS at six time points over 6 months. Questionnaires were administered to collect information on demographic, lifestyle and dietary data. Mean age of the participants was 36.6 years, 62.2% were female, 83.8% Caucasian and 85.1% were non-smoking at baseline. There was a good agreement between a single measure of skin carotenoids by RRS and multiple measures (weighted κ = 0.80; 95% CI 0.72, 0.88). The same variables were significantly associated with carotenoid status based on single or multiple measures, including a positive association with intake of total carotenoids (P<0.01) and an inverse association with season of measurement (P≤0.05). The exception was recent sun exposure, which emerged as a significant predictor of lower carotenoid status only when using multiple RRS measures (P≤0.01). A single RRS measure was reasonably accurate at classifying usual skin carotenoid status. Researchers using RRS may want to take into account other factors that are associated with the biomarker, including season of measurement and recent sun exposure. PMID:23351238

  5. Effects of tunable excitation in carotenoids explained by the vibrational energy relaxation approach.

    PubMed

    Balevičius, Vytautas; Lincoln, Craig N; Viola, Daniele; Cerullo, Giulio; Hauer, Jürgen; Abramavicius, Darius

    2017-07-24

    Carotenoids are fundamental building blocks of natural light harvesters with convoluted and ultrafast energy deactivation networks. In order to disentangle such complex relaxation dynamics, several studies focused on transient absorption measurements and their dependence on the pump wavelength. However, such findings are inconclusive and sometimes contradictory. In this study, we compare internal conversion dynamics in [Formula: see text]-carotene, pumped at the first, second, and third vibronic progression peak. Instead of employing data fitting algorithms based on global analysis of the transient absorption spectra, we apply a fully quantum mechanical model to treat the high-frequency symmetric carbon-carbon (C=C and C-C) stretching modes explicitly. This model successfully describes observed population dynamics as well as spectral line shapes in their time-dependence and allows us to reach two conclusions: Firstly, the broadening of the induced absorption upon excess excitation is an effect of vibrational cooling in the first excited state ([Formula: see text]). Secondly, the internal conversion rate between the second excited state ([Formula: see text]) and [Formula: see text] crucially depends on the relative curve displacement. The latter point serves as a new perspective on solvent- and excitation wavelength-dependent experiments and lifts contradictions between several studies found in literature.

  6. Spatiotemporal Analysis of Multichannel EEG: CARTOOL

    PubMed Central

    Brunet, Denis; Murray, Micah M.; Michel, Christoph M.

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way. PMID:21253358

  7. Spatiotemporal analysis of multichannel EEG: CARTOOL.

    PubMed

    Brunet, Denis; Murray, Micah M; Michel, Christoph M

    2011-01-01

    This paper describes methods to analyze the brain's electric fields recorded with multichannel Electroencephalogram (EEG) and demonstrates their implementation in the software CARTOOL. It focuses on the analysis of the spatial properties of these fields and on quantitative assessment of changes of field topographies across time, experimental conditions, or populations. Topographic analyses are advantageous because they are reference independents and thus render statistically unambiguous results. Neurophysiologically, differences in topography directly indicate changes in the configuration of the active neuronal sources in the brain. We describe global measures of field strength and field similarities, temporal segmentation based on topographic variations, topographic analysis in the frequency domain, topographic statistical analysis, and source imaging based on distributed inverse solutions. All analysis methods are implemented in a freely available academic software package called CARTOOL. Besides providing these analysis tools, CARTOOL is particularly designed to visualize the data and the analysis results using 3-dimensional display routines that allow rapid manipulation and animation of 3D images. CARTOOL therefore is a helpful tool for researchers as well as for clinicians to interpret multichannel EEG and evoked potentials in a global, comprehensive, and unambiguous way.

  8. Recording and marking with silicon multichannel electrodes.

    PubMed

    Townsend, George; Peloquin, Pascal; Kloosterman, Fabian; Hetke, Jamille F; Leung, L Stan

    2002-04-01

    This protocol describes an implementation of recording and analysis of evoked potentials in the hippocampal cortex, combined with lesioning using multichannel silicon probes. Multichannel recording offers the advantage of capturing a potential field at one instant in time. The potentials are then subjected to current source density (CSD) analysis, to reveal the layer-by-layer current sources and sinks. Signals from each channel of a silicon probe (maximum 16 channels in this study) were amplified and digitized at up to 40 kHz after sample-and-hold circuits. A modular lesion circuit board could be inserted between the input preamplifiers and the silicon probe, such that any one of the 16 electrodes could be connected to a DC lesion current. By making a lesion at the electrode showing a physiological event of interest, the anatomical location of the event can be precisely identified, as shown for the distal dendritic current sink in CA1 following medial perforant path stimulation. Making two discrete lesions through the silicon probe is useful to indicate the degree of tissue shrinkage during histological procedures. In addition, potential/CSD profiles were stable following small movements of the silicon probe, suggesting that the probe did not cause excessive damage to the brain.

  9. Carotenoid composition of hydroponic leafy vegetables.

    PubMed

    Kimura, Mieko; Rodriguez-Amaya, Delia B

    2003-04-23

    Because hydroponic production of vegetables is becoming more common, the carotenoid composition of hydroponic leafy vegetables commercialized in Campinas, Brazil, was determined. All samples were collected and analyzed in winter. Lactucaxanthin was quantified for the first time and was found to have concentrations similar to that of neoxanthin in the four types of lettuce analyzed. Lutein predominated in cress, chicory, and roquette (75.4 +/- 10.2, 57.0 +/- 10.3, and 52.2 +/- 12.6 microg/g, respectively). In the lactucaxanthin-containing lettuces, beta-carotene and lutein were the principal carotenoids (ranging from 9.9 +/- 1.5 to 24.6 +/- 3.1 microg/g and from 10.2 +/- 1.0 to 22.9 +/- 2.6 microg/g, respectively). Comparison of hydroponic and field-produced curly lettuce, taken from neighboring farms, showed that the hydroponic lettuce had significantly lower lutein, beta-carotene, violaxanthin, and neoxanthin contents than the conventionally produced lettuce. Because the hydroponic farm had a polyethylene covering, less exposure to sunlight and lower temperatures may have decreased carotenogenesis.

  10. Resonance Raman detection of carotenoid antioxidants in living human tissue

    PubMed Central

    Ermakov, Igor V.; Sharifzadeh, M.; Ermakova, Maia; Gellermann, W.

    2011-01-01

    Increasing evidence points to the beneficial effects of carotenoid antioxidants in the human body. Several studies, for example, support the protective role of lutein and zeaxanthin in the prevention of age-related eye diseases. If present in high concentrations in the macular region of the retina, lutein and zeaxanthin provide pigmentation in this most light sensitive retinal spot, and as a result of light filtering and/or antioxidant action, delay the onset of macular degeneration with increasing age. Other carotenoids, such as lycopene and beta-carotene, play an important role as well in the protection of skin from UV and short-wavelength visible radiation. Lutein and lycopene may also have protective function for cardiovascular health, and lycopene may play a role in the prevention of prostate cancer. Motivated by the growing importance of carotenoids in health and disease, and recognizing the lack of any accepted noninvasive technology for the detection of carotenoids in living human tissue, we explore resonance Raman spectroscopy as a novel approach for noninvasive, laser optical carotenoid detection. We review the main results achieved recently with the Raman detection approach. Initially we applied the method to the detection of macular carotenoid pigments, and more recently to the detection of carotenoids in human skin and mucosal tissues. Using skin carotenoid Raman instruments, we measure the carotenoid response from the stratum corneum layer of the palm of the hand for a population of 1375 subjects and develope a portable skin Raman scanner for field studies. These experiments reveal that carotenoids are a good indicator of antioxidant status. They show that people with high oxidative stress, like smokers, and subjects with high sunlight exposure, in general, have reduced skin carotenoid levels, independent of their dietary carotenoid consumption. We find the Raman technique to be precise, specific, sensitive, and well suitable for clinical as well as

  11. Resonance Raman detection of carotenoid antioxidants in living human tissue.

    PubMed

    Ermakov, Igor V; Sharifzadeh, M; Ermakova, Maia; Gellermann, W

    2005-01-01

    Increasing evidence points to the beneficial effects of carotenoid antioxidants in the human body. Several studies, for example, support the protective role of lutein and zeaxanthin in the prevention of age-related eye diseases. If present in high concentrations in the macular region of the retina, lutein and zeaxanthin provide pigmentation in this most light sensitive retinal spot, and as a result of light filtering and/or antioxidant action, delay the onset of macular degeneration with increasing age. Other carotenoids, such as lycopene and beta-carotene, play an important role as well in the protection of skin from UV and short-wavelength visible radiation. Lutein and lycopene may also have protective function for cardiovascular health, and lycopene may play a role in the prevention of prostate cancer. Motivated by the growing importance of carotenoids in health and disease, and recognizing the lack of any accepted noninvasive technology for the detection of carotenoids in living human tissue, we explore resonance Raman spectroscopy as a novel approach for noninvasive, laser optical carotenoid detection. We review the main results achieved recently with the Raman detection approach. Initially we applied the method to the detection of macular carotenoid pigments, and more recently to the detection of carotenoids in human skin and mucosal tissues. Using skin carotenoid Raman instruments, we measure the carotenoid response from the stratum corneum layer of the palm of the hand for a population of 1375 subjects and develop a portable skin Raman scanner for field studies. These experiments reveal that carotenoids are a good indicator of antioxidant status. They show that people with high oxidative stress, like smokers, and subjects with high sunlight exposure, in general, have reduced skin carotenoid levels, independent of their dietary carotenoid consumption. We find the Raman technique to be precise, specific, sensitive, and well suitable for clinical as well as

  12. Coordinate expression of multiple bacterial carotenoid genes in canola leading to altered carotenoid production.

    PubMed

    Ravanello, Monica P; Ke, Dangyang; Alvarez, Julie; Huang, Bihua; Shewmaker, Christine K

    2003-10-01

    Carotenoids have drawn much attention recently because of their potentially positive benefits to human health as well as their utility in both food and animal feed. Previous work in canola (Brassica napus) seed over-expressing the bacterial phytoene synthase gene (crtB) demonstrated a change in carotenoid content, such that the total levels of carotenoids, including phytoene and downstream metabolites like beta-carotene, were elevated 50-fold, with the ratio of beta- to alpha-carotene being 2:1. This result raised the possibility that the composition of metabolites in this pathway could be modified further in conjunction with the increased flux obtained with crtB. Here we report on the expression of additional bacterial genes for the enzymes geranylgeranyl diphosphate synthase (crtE), phytoene desaturase (crtI) and lycopene cyclase (crtY and the plant B. napus lycopene beta-cyclase) engineered in conjunction with phytoene synthase (crtB) in transgenic canola seed. Analysis of the carotenoid levels by HPLC revealed a 90% decrease in phytoene levels for the double construct expressing crtB in conjunction with crtI. The transgenic seed from all the double constructs, including the one expressing the bacterial crtB and the plant lycopene beta-cyclase showed an increase in the levels of total carotenoid similar to that previously observed by expressing crtB alone but minimal effects were observed with respect to the ratio of beta- to alpha-carotene compared to the original construct. However, the beta- to alpha-carotene ratio was increased from 2:1 to 3:1 when a triple construct consisting of the bacterial phytoene synthase, phytoene desaturase and lycopene cyclase genes were expressed together. This result suggests that the bacterial genes may form an aggregate complex that allows in vivo activity of all three proteins through substrate channeling. This finding should allow further manipulation of the carotenoid biosynthetic pathway for downstream products with

  13. Carotenoid biosynthetic genes in Brassica rapa: comparative genomic analysis, phylogenetic analysis, and expression profiling.

    PubMed

    Li, Peirong; Zhang, Shujiang; Zhang, Shifan; Li, Fei; Zhang, Hui; Cheng, Feng; Wu, Jian; Wang, Xiaowu; Sun, Rifei

    2015-07-03

    Carotenoids are isoprenoid compounds synthesized by all photosynthetic organisms. Despite much research on carotenoid biosynthesis in the model plant Arabidopsis thaliana, there is a lack of information on the carotenoid pathway in Brassica rapa. To better understand its carotenoid biosynthetic pathway, we performed a systematic analysis of carotenoid biosynthetic genes at the genome level in B. rapa. We identified 67 carotenoid biosynthetic genes in B. rapa, which were orthologs of the 47 carotenoid genes in A. thaliana. A high level of synteny was observed for carotenoid biosynthetic genes between A. thaliana and B. rapa. Out of 47 carotenoid biosynthetic genes in A. thaliana, 46 were successfully mapped to the 10 B. rapa chromosomes, and most of the genes retained more than one copy in B. rapa. The gene expansion was caused by the whole-genome triplication (WGT) event experienced by Brassica species. An expression analysis of the carotenoid biosynthetic genes suggested that their expression levels differed in root, stem, leaf, flower, callus, and silique tissues. Additionally, the paralogs of each carotenoid biosynthetic gene, which were generated from the WGT in B. rapa, showed significantly different expression levels among tissues, suggesting differentiated functions for these multi-copy genes in the carotenoid pathway. This first systematic study of carotenoid biosynthetic genes in B. rapa provides insights into the carotenoid metabolic mechanisms of Brassica crops. In addition, a better understanding of carotenoid biosynthetic genes in B. rapa will contribute to the development of conventional and transgenic B. rapa cultivars with enriched carotenoid levels in the future.

  14. Electronic absorption and ground state structure of carotenoid molecules.

    PubMed

    Mendes-Pinto, Maria M; Sansiaume, Elodie; Hashimoto, Hideki; Pascal, Andrew A; Gall, Andrew; Robert, Bruno

    2013-09-26

    Predicting the complete electronic structure of carotenoid molecules remains an extremely complex problem, particularly in anisotropic media such as proteins. In this paper, we address the electronic properties of nine relatively simple carotenoids by the combined use of electronic absorption and resonance Raman spectroscopies. Linear carotenoids exhibit an excellent correlation between (i) the inverse of their conjugation chain length N, (ii) the energy of their S0 → S2 electronic transition, and (iii) the position of their ν1 Raman band (corresponding to the stretching mode of their conjugated C═C bonds). For cyclic carotenoids such as β-carotene, this correlation is also observed between the latter two parameters (S0 → S2 energy and ν1 frequency), whereas their "nominal" conjugation length N does not follow the same relationship. We conclude that β-carotene and cyclic carotenoids in general exhibit a shorter effective conjugation length than that expected from their chemical structure. In addition, the effect of solvent polarizability on these molecular parameters was investigated for four of the carotenoids used in this study. We demonstrate that resonance Raman spectroscopy can discriminate between the different effects underlying shifts in the S0 → S2 transition of carotenoid molecules.

  15. Carotenoid Biosynthesis in Intraerythrocytic Stages of Plasmodium falciparum*S⃞

    PubMed Central

    Tonhosolo, Renata; D'Alexandri, Fabio L.; de Rosso, Veridiana V.; Gazarini, Marcos L.; Matsumura, Miriam Y.; Peres, Valnice J.; Merino, Emilio F.; Carlton, Jane M.; Wunderlich, Gerhard; Mercadante, Adriana Z.; Kimura, Emília A.; Katzin, Alejandro M.

    2009-01-01

    Carotenoids are widespread lipophilic pigments synthesized by all photosynthetic organisms and some nonphotosynthetic fungi and bacteria. All carotenoids are derived from the C40 isoprenoid precursor geranylgeranyl pyrophosphate, and their chemical and physical properties are associated with light absorption, free radical scavenging, and antioxidant activity. Carotenoids are generally synthesized in well defined subcellular organelles, the plastids, which are also present in the phylum Apicomplexa, which comprises a number of important human parasites, such as Plasmodium and Toxoplasma. Recently, it was demonstrated that Toxoplasma gondii synthesizes abscisic acid. We therefore asked if Plasmodium falciparum is also capable of synthesizing carotenoids. Herein, biochemical findings demonstrated the presence of carotenoid biosynthesis in the intraerythrocytic stages of the apicomplexan parasite P. falciparum. Using metabolic labeling with radioisotopes, in vitro inhibition tests with norflurazon, a specific inhibitor of plant carotenoid biosynthesis, the results showed that intraerythrocytic stages of P. falciparum synthesize carotenoid compounds. A plasmodial enzyme that presented phytoene synthase activity was also identified and characterized. These findings not only contribute to the current understanding of P. falciparum evolution but shed light on a pathway that could serve as a chemotherapeutic target. PMID:19203994

  16. THE CAROTENOID BIOSYNTHETIC PATHWAY: THINKING IN ALL DIMENSIONS

    PubMed Central

    Shumskaya, Maria; Wurtzel, Eleanore T.

    2013-01-01

    The carotenoid biosynthetic pathway serves manifold roles in plants related to photosynthesis, photoprotection, development, stress hormones, and various volatiles and signalling apocarotenoids. The pathway also produces compounds that impact human nutrition and metabolic products that contribute to fragrance and flavour of food and non-food crops. It is no surprise that the pathway has been a target of metabolic engineering, most prominently in the case of Golden Rice. The future success and predictability of metabolic engineering of carotenoids rests in the ability to target carotenoids for specific physiological purposes as well as to simultaneously modify carotenoids along with other desired traits. Here, we ask whether predictive metabolic engineering of the carotenoid pathway is indeed possible. Despite a long history of research on the pathway, at this point in time we can only describe the pathway as a parts list and have almost no knowledge of the location of the complete pathway, how it is assembled, and whether there exists any trafficking of the enzymes or the carotenoids themselves. We discuss the current state of knowledge regarding the “complete” pathway and make the argument that predictive metabolic engineering of the carotenoid pathway (and other pathways) will require investigation of the three dimensional state of the pathway as it may exist in plastids of different ultrastructures. Along with this message we point out the need to develop new types of visualization tools and resources that better reflect the dynamic nature of biosynthetic pathways. PMID:23683930

  17. Raman measurement of carotenoid composition in human skin

    NASA Astrophysics Data System (ADS)

    Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

    2004-07-01

    The carotenoids lycopene and beta-carotene are powerful antioxidants in skin and are thought to act as scavengers for free radicals and singlet oxygen. The role of carotenoid species in skin health is of strong current interest. We demonstrate the possibility to use Resonance Raman spectroscopy for fast, non-invasive, highly specific, and quantitative detection of beta-carotene and lycopene in human skin. Analyzing Raman signals originating from the carbon-carbon double bond stretch vibrations of the carotenoid molecules under blue and green laser excitation, we were able to characterize quantitatively the relative concentrations of each carotenoid species in-vivo. In the selective detection, we take advantage of different Raman cross-section spectral profiles for beta-carotene and lycopene molecules, and obtain a quantitative assessment of individual long-chain carotenoid species in the skin rather than their cumulative levels. Preliminary dual-wavelength Raman measurements reveal significant differences in the carotenoid composition of different subjects. The technique holds promise for rapid screening of carotenoid compositions in human skin in large populations and may be suitable in clinical studies for assessing the risk for cutaneous diseases.

  18. Carotenoids acts as reinforcers of the Acholeplasma laidlawii lipid bilayer.

    PubMed Central

    Rottem, S; Markowitz, O

    1979-01-01

    Acholeplasma laidlawii cells grown with oleic acid produced much more colored carotenoids than did cells grown with elaidic acid. The amount of carotenoids was decreased 80 to 90% by growing the cells with 0.05 M propionate, resulting in a marked increase in the mobility of both 5-doxylstearate and 12-doxylstearate incorporated into the membranes. The fatty acid composition of the propionate-grown cells differed from that of cells grown without propionate by containing odd-numbered rather than even-numbered saturated fatty acids, but the ratios of saturated to unsaturated fatty acids were the same. To determine whether the carotenoids are the cause for the restricted mobility in the membranes, the carotenoids were selectively removed from A. laidlawii membranes by incubating the membranes with phosphatidylcholine vesicles. The carotenoid-depleted membranes showed an increase in the mobility of the hydrocarbon chains of the spin-labeled fatty acids. Furthermore, the incorporation of carotenoids into artificial membrane vesicles restricted the mobility of the hydrocarbon chain. Our results support the notion that the carotenoids in A. laidlawii act as a rigid insert reinforcing the membrane bilayer. PMID:533770

  19. A complex carotenoid palette tunes avian colour vision.

    PubMed

    Toomey, Matthew B; Collins, Aaron M; Frederiksen, Rikard; Cornwall, M Carter; Timlin, Jerilyn A; Corbo, Joseph C

    2015-10-06

    The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken (Gallus gallus). We find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Thus, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering.

  20. Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

    PubMed

    Babin, A; Saciat, C; Teixeira, M; Troussard, J-P; Motreuil, S; Moreau, J; Moret, Y

    2015-04-01

    The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supplementation with carotenoids and immune challenge on immune defences and the activity of the antioxidant enzymes SOD and CAT, in the amphipod crustacean Gammarus pulex. Dietary supplementation increased the concentrations of circulating carotenoids and haemocytes in the haemolymph, while the immune response induced the consumption of circulating carotenoids and a drop of haemocyte density. Interestingly, supplemented gammarids exhibited down-regulated SOD activity but high CAT activity compared to control ones. Our study reveals specific interactions of dietary carotenoids with endogenous antioxidant enzymes, and further underlines the potential importance of carotenoids in the evolution of immunity and/or of antioxidant mechanisms in crustaceans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The metabolomics of carotenoids in engineered cell factory.

    PubMed

    Liu, Guan-Nan; Zhu, Yue-Hui; Jiang, Jian-Guo

    2009-07-01

    Carotenoids such as beta-carotene, lycopene, and antheraxanthin have plenty of scientific and commercial value. The comprehensive investigation of carotenoids drives people to improve and develop all kinds of analytical techniques to approach or even achieve "versatile" analysis. The metabolic engineering efforts in plants and algae have progressed rapidly, aiming to enable the use of plants and algae as "cell factories" for producing specific or novel carotenoids, such as beta-carotene (provitamin A) in Gold rice, while the emerging technologies of metabolomics support it by providing comprehensive analysis of carotenoids biochemical characterizations. This review describes metabolomics as a high-throughput platform to study carotenoids, including the engineering methods in the plants or algae, the bioinformatics for metabolomics, and the metabolomics of carotenoids in engineered cell factory. Modern systems biology tools, together with the development of genomics and metabolomics databases, will dramatically facilitate the advancement of our knowledge in gene-to-metabolite networks in plants. Metabolomics accompanying genomics, transcriptomics, and proteomics as well as bioinformatics facilitate metabolic engineering efforts towards designing superior biocatalysts in cell factories. Ongoing advances in biological techniques coupled with crucial metabolic networks will further promote plants and algae as attractive platforms for the production of numerous high-value compounds such as carotenoids.

  2. Biotechnological production of carotenoids by yeasts: an overview.

    PubMed

    Mata-Gómez, Luis Carlos; Montañez, Julio César; Méndez-Zavala, Alejandro; Aguilar, Cristóbal Noé

    2014-01-21

    Nowadays, carotenoids are valuable molecules in different industries such as chemical, pharmaceutical, poultry, food and cosmetics. These pigments not only can act as vitamin A precursors, but also they have coloring and antioxidant properties, which have attracted the attention of the industries and researchers. The carotenoid production through chemical synthesis or extraction from plants is limited by low yields that results in high production costs. This leads to research of microbial production of carotenoids, as an alternative that has shown better yields than other aforementioned. In addition, the microbial production of carotenoids could be a better option about costs, looking for alternatives like the use of low-cost substrates as agro-industrials wastes. Yeasts have demonstrated to be carotenoid producer showing an important growing capacity in several agro-industrial wastes producing high levels of carotenoids. Agro-industrial wastes provide carbon and nitrogen source necessary, and others elements to carry out the microbial metabolism diminishing the production costs and avoiding pollution from these agro-industrial wastes to the environmental. Herein, we discuss the general and applied concepts regarding yeasts carotenoid production and the factors influencing carotenogenesis using agro-industrial wastes as low-cost substrates.

  3. Biotechnological production of carotenoids by yeasts: an overview

    PubMed Central

    2014-01-01

    Nowadays, carotenoids are valuable molecules in different industries such as chemical, pharmaceutical, poultry, food and cosmetics. These pigments not only can act as vitamin A precursors, but also they have coloring and antioxidant properties, which have attracted the attention of the industries and researchers. The carotenoid production through chemical synthesis or extraction from plants is limited by low yields that results in high production costs. This leads to research of microbial production of carotenoids, as an alternative that has shown better yields than other aforementioned. In addition, the microbial production of carotenoids could be a better option about costs, looking for alternatives like the use of low-cost substrates as agro-industrials wastes. Yeasts have demonstrated to be carotenoid producer showing an important growing capacity in several agro-industrial wastes producing high levels of carotenoids. Agro-industrial wastes provide carbon and nitrogen source necessary, and others elements to carry out the microbial metabolism diminishing the production costs and avoiding pollution from these agro-industrial wastes to the environmental. Herein, we discuss the general and applied concepts regarding yeasts carotenoid production and the factors influencing carotenogenesis using agro-industrial wastes as low-cost substrates. PMID:24443802

  4. Physalis alkekengi Carotenoidic Extract Inhibitor of Soybean Lipoxygenase-1 Activity

    PubMed Central

    Chedea, Veronica Sanda; Pintea, Adela; Bunea, Andrea; Braicu, Cornelia; Stanila, Andreea; Socaciu, Carmen

    2014-01-01

    The aim of this study was to evaluate the effect of the carotenoidic saponified extract of Physalis alkekengi sepals (PA) towards the lipoxygenase (LOX) oxidation of linoleic acid. Lipoxygenase activity in the presence of carotenoids, standard and from extract, was followed by its kinetic behaviour determining the changes in absorption at 234 nm. The standard carotenoids used were β-carotene (β-car), lutein (Lut), and zeaxanthin (Zea). The calculated enzymatic specific activity (ESA) after 600 s of reaction proves that PA carotenoidic extract has inhibitory effect on LOX oxidation of linoleic acid. A longer polyenic chain of carotenoid structure gives a higher ESA during the first reaction seconds. This situation is not available after 600 s of reaction and may be due to a destruction of this structure by cooxidation of carotenoids, besides the classical LOX reaction. The PA carotenoidic extract inhibiting the LOX-1 reaction can be considered a source of lipoxygenase inhibitors. PMID:24511537

  5. Modulation of the carotenoid bioaccessibility through liposomal encapsulation.

    PubMed

    Tan, Chen; Zhang, Yating; Abbas, Shabbar; Feng, Biao; Zhang, Xiaoming; Xia, Shuqin

    2014-11-01

    The low bioaccessibility of carotenoids is currently a challenge to their incorporation in pharmaceutics, nutraceuticals and functional foods. The aim of this study was to evaluate the modulating effects of liposome encapsulation on the bioaccessibility, and its relationship with carotenoid structure and incorporated concentration. The physical stability of liposomes, lipid digestibility, carotenoids release and bioaccessibility were investigated during incubation in a simulated gastrointestinal tract. Analysis on the liposome size and morphology showed that after digestion, the majority of particles maintained spherical shape with only an increase of size in liposomes loading β-carotene or lutein. However, a large proportion of heterogeneous particles were visible in the micelle phase of liposomes loading lycopene or canthaxanthin. It was also found that the release of lutein and β-carotene from liposomes was inhibited in a simulated gastric fluid, while was slow and sustained in a simulated intestinal fluid. By contrast, lycopene and canthaxanthin exhibited fast and considerable release in the gastrointestinal media. Both carotenoid bioaccessibility and micellization content decreased with the increase of incorporated concentration. Anyway, the bioaccessibility of carotenoids after encapsulated in liposomes was in the following order: lutein>β-carotene>lycopene>canthaxanthin. Bivariate correlation analysis revealed that carotenoid bioaccessibility depended strongly on the incorporating ability of carotenoids into a lipid bilayer, loading content, and nature of the system.

  6. A complex carotenoid palette tunes avian colour vision

    PubMed Central

    Toomey, Matthew B.; Collins, Aaron M.; Frederiksen, Rikard; Cornwall, M. Carter; Timlin, Jerilyn A.; Corbo, Joseph C.

    2015-01-01

    The brilliantly coloured cone oil droplets of the avian retina function as long-pass cut-off filters that tune the spectral sensitivity of the photoreceptors and are hypothesized to enhance colour discrimination and improve colour constancy. Although it has long been known that these droplets are pigmented with carotenoids, their precise composition has remained uncertain owing to the technical challenges of measuring these very small, dense and highly refractile optical organelles. In this study, we integrated results from high-performance liquid chromatography, hyperspectral microscopy and microspectrophotometry to obtain a comprehensive understanding of oil droplet carotenoid pigmentation in the chicken (Gallus gallus). We find that each of the four carotenoid-containing droplet types consists of a complex mixture of carotenoids, with a single predominant carotenoid determining the wavelength of the spectral filtering cut-off. Consistent with previous reports, we find that the predominant carotenoid type in the oil droplets of long-wavelength-sensitive, medium-wavelength-sensitive and short-wavelength-sensitive type 2 cones are astaxanthin, zeaxanthin and galloxanthin, respectively. In addition, the oil droplet of the principal member of the double cone contains a mixture of galloxanthin and two hydroxycarotenoids (lutein and zeaxanthin). Short-wavelength-absorbing apocarotenoids are present in all of the droplet types, providing filtering of light in a region of the spectrum where filtering by hydroxy- and ketocarotenoids may be incomplete. Thus, birds rely on a complex palette of carotenoid pigments within their cone oil droplets to achieve finely tuned spectral filtering. PMID:26446559

  7. TiO2 and F-TiO2 photocatalytic deactivation in gas phase

    NASA Astrophysics Data System (ADS)

    El-Alami, W.; Garzón Sousa, D.; Díaz González, J. M.; Fernández Rodríguez, C.; González Díaz, O.; Doña Rodríguez, J. M.; El Azzouzi, M.; Araña, J.

    2017-09-01

    TiO2 deactivation processes during gas-phase degradation of ethanol were studied. To force the deactivation processes, various cycles were performed, avoiding the degradation of acetates. It was observed that acetates adsorbed on the anatase phase of catalysts provoke the transference of electrons to surface traps which modify the electron states of the semiconductor. The same deactivation studies were also performed with fluorinated TiO2. It was noted that the electrons present in the surface traps, as a consequence of the Ti-F interaction, react with the holes during irradiation and provoke a change in the electron states of the semiconductor.

  8. Carotenoid accumulation in the tissues of zebra finches: predictors of integumentary pigmentation and implications for carotenoid allocation strategies.

    PubMed

    McGraw, Kevin J; Toomey, Matthew B

    2010-01-01

    Carotenoid pigments produce the bright yellow to red ornamental colors of many animals, especially birds, and must ultimately be derived from the diet. However, they are also valuable for many physiological functions (e.g., antioxidants, immunostimulants, photoprotection, visual tuning, yolk nourishment to embryos), and as a result they are present in numerous internal body tissues (e.g., liver, adipose tissue, retina) whose carotenoid types and amounts are rarely studied in the context of color acquisition. Because male and female animals typically place different priorities on fitness-enhancing activities (e.g., gametic investment in females, sexual attraction in males), carotenoid allocation may track such investment patterns in the two sexes, and we can test for such sex-specific priorities of carotenoids by assessing body-tissue distributions of these pigments. We used high-performance liquid chromatography to identify and quantify carotenoid pigments from the plasma, liver, adipose tissue, and retina as well as the beak and legs of male and female zebra finches (Taeniopygia guttata), a species in which males display sexually attractive, red, carotenoid-based beak coloration and females also display some (albeit a less rich orange) beak color. To our knowledge, this is the first study of the predictors of carotenoid-based leg coloration-another potentially important visual signal-in this species. The same suite of dietary (e.g., lutein, zeaxanthin, beta-cryptoxanthin) and metabolically derived (e.g., dehydrolutein, anhydrolutein) yellow and orange carotenoids was present in plasma, liver, and adipose tissue of both sexes. Retina contained two different metabolites (astaxanthin and galloxanthin) that serve specific functions in association with unique photoreceptor types in the eye. Beaks were enriched with four red ketocarotenoid derivatives in both sexes (alpha-doradexanthin, adonirubin, astaxanthin, and canthaxanthin), while the carotenoid profile of legs

  9. Multi-channel scanning SQUID microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Su-Young

    I designed, fabricated, assembled, and tested an 8-channel high- Tc scanning SQUID system. I started by modifying an existing single-channel 77 K high-Tc scanning SQUID microscope into a multi-channel system with the goal of reducing the scanning time and improving the spatial resolution by increasing the signal-to-noise ratio S/N. I modified the window assembly, SQUID chip assembly, cold-finger, and vacuum connector. The main concerns for the multi-channel system design were to reduce interaction between channels, to optimize the use of the inside space of the dewar for more than 50 shielded wires, and to achieve good spatial resolution. In the completed system, I obtained the transfer function and the dynamic range (phimax ˜ 11phi0) for each SQUID. At 1kHz, the slew rate is about 3000 phi0/s. I also found that the white noise level varies from 5 muphi0/Hz1/2 to 20 muphi 0/Hz1/2 depending on the SQUID. A new data acquisition program was written that triggered on position and collects data from up to eight SQUIDS. To generate a single image from the multichannel system, I calibrated the tilt of the xy-stage and z-stage manually, rearranged the scanned data by cutting overlapping parts, and determined the applied field by multiplying by the mutual inductance matrix. I found that I could reduce scanning time and improve the image quality by doing so. In addition, I have analyzed and observed the effect of position noise on magnetic field images and used these results to find the position noise in my scanning SQUID microscope. My analysis reveals the relationship between spatial resolution and position noise and that my system was dominated by position noise under typical operating conditions. I found that the smaller the sensor-sample separation, the greater the effect of position noise is on the total effective magnetic field noise and on spatial resolution. By averaging several scans, I found that I could reduce position noise and that the spatial resolution can

  10. Oxidation of carotenoids by heat and tobacco smoke.

    PubMed

    Hurst, John S; Contreras, Janice E; Siems, Werner G; Van Kuijk, Frederik J G M

    2004-01-01

    The stability to autoxidation of the polar carotenoids, lutein and zeaxanthin, was compared to that of the less polar carotenoids, beta-carotene and lycopene at physiologically or pathophysiologically relevant concentrations of 2 and 6 microM, after exposure to heat or cigarette smoke. Three methodological approaches were used: 1) Carotenoids dissolved in solvents with different polarities were incubated at 37 and 80 degrees C for different times. 2) Human plasma samples were subjected to the same temperature conditions. 3) Methanolic carotenoid solutions and plasma were also exposed to whole tobacco smoke from 1-5 unfiltered cigarettes. The concentrations of individual carotenoids in different solvents were determined spectrophotometrically. Carotenoids from plasma were extracted and analyzed using high performance liquid chromatography. Carotenoids were generally more stable at 37 than at 80 degrees C. In methanol and dichloromethane the thermal degradation of beta-carotene and lycopene was faster than that of lutein and zeaxanthin. However, in tetrahydrofuran beta-carotene and zeaxanthin degraded faster than lycopene and lutein. Plasma carotenoid levels at 37 degrees C did not change, but decreased at 80 degrees C. The decrease of beta-carotene and lycopene levels was higher than those for lutein and zeaxanthin. Also in the tobacco smoke experiments the highest autoxidation rates were found for beta-carotene and lycopene at 2 microM, but at 6 microM lutein and zeaxanthin depleted to the same extent as beta-carotene. These data support our previous studies suggesting that oxidative stress degrade beta-carotene and lycopene faster than lutein and zeaxanthin. The only exception was the thermal degradation of carotenoids solubilized in tetrahydrofuran, which favors faster breakdown of beta-carotene and zeaxanthin.

  11. Structural and Functional Roles of Carotenoids in Chlorosomes

    PubMed Central

    Arellano, Juan B.; Collins, Aaron M.; Laurinmäki, Pasi; Torkkeli, Mika; Löflund, Benita; Serimaa, Ritva E.; Blankenship, Robert E.; Tuma, Roman

    2013-01-01

    Chlorosomes are large light-harvesting complexes found in three phyla of anoxygenic photosynthetic bacteria. Chlorosomes are primarily composed of self-assembling pigment aggregates. In addition to the main pigment, bacteriochlorophyll c, d, or e, chlorosomes also contain variable amounts of carotenoids. Here, we use X-ray scattering and electron cryomicroscopy, complemented with absorption spectroscopy and pigment analysis, to compare the morphologies, structures, and pigment compositions of chlorosomes from Chloroflexus aurantiacus grown under two different light conditions and Chlorobaculum tepidum. High-purity chlorosomes from C. aurantiacus contain about 20% more carotenoid per bacteriochlorophyll c molecule when grown under low light than when grown under high light. This accentuates the light-harvesting function of carotenoids, in addition to their photoprotective role. The low-light chlorosomes are thicker due to the overall greater content of pigments and contain domains of lamellar aggregates. Experiments where carotenoids were selectively extracted from intact chlorosomes using hexane proved that they are located in the interlamellar space, as observed previously for species belonging to the phylum Chlorobi. A fraction of the carotenoids are localized in the baseplate, where they are bound differently and cannot be removed by hexane. In C. tepidum, carotenoids cannot be extracted by hexane even from the chlorosome interior. The chemical structure of the pigments in C. tepidum may lead to π-π interactions between carotenoids and bacteriochlorophylls, preventing carotenoid extraction. The results provide information about the nature of interactions between bacteriochlorophylls and carotenoids in the protein-free environment of the chlorosome interior. PMID:23396908

  12. Variability of Carotenoid Biosynthesis in Orange Colored Capsicum spp.

    PubMed Central

    Guzman, Ivette; Hamby, Shane; Romero, Joslynn; Bosland, Paul W.; O’Connell, Mary A.

    2010-01-01

    Pepper, Capsicum spp., is a worldwide crop valued for heat, nutrition, and rich pigment content. Carotenoids, the largest group of plant pigments, function as antioxidants and as vitamin A precursors. The most abundant carotenoids in ripe pepper fruits are β-carotene, capsanthin, and capsorubin. In this study, the carotenoid composition of orange fruited Capsicum lines was defined along with the allelic variability of the biosynthetic enzymes. The carotenoid chemical profiles present in seven orange pepper varieties were determined using a novel UPLC method. The orange appearance of the fruit was due either to the accumulation of β-carotene, or in two cases, due to only the accumulation of red and yellow carotenoids. Four carotenoid biosynthetic genes, Psy, Lcyb, CrtZ-2, and Ccs were cloned and sequenced from these cultivars. This data tested the hypothesis that different alleles for specific carotenoid biosynthetic enzymes are associated with specific carotenoid profiles in orange peppers. While the coding regions within Psy and CrtZ-2 did not change in any of the lines, the genomic sequence contained introns not previously reported. Lcyb and Ccs contained no introns but did exhibit polymorphisms resulting in amino acid changes; a new Ccs variant was found. When selectively breeding for high provitamin A levels, phenotypic recurrent selection based on fruit color is not sufficient, carotenoid chemical composition should also be conducted. Based on these results, specific alleles are candidate molecular markers for selection of orange pepper lines with high β-carotene and therefore high pro-vitamin A levels. PMID:20582146

  13. Carotenoids in white- and red-fleshed loquat fruits.

    PubMed

    Zhou, Chun-Hua; Xu, Chang-Jie; Sun, Chong-De; Li, Xian; Chen, Kun-Song

    2007-09-19

    Fruits of 23 loquat ( Eriobotrya japonica Lindl.) cultivars, of which 11 were white-fleshed and 12 red-fleshed, were analyzed for color, carotenoid content, and vitamin A values. Color differences between two loquat groups were observed in the peel as well as in the flesh. beta-Carotene and lutein were the major carotenoids in the peel, which accounted for about 60% of the total colored carotenoids in both red- and white-fleshed cultivars. beta-Cryptoxanthin and, in some red-fleshed cultivars, beta-carotene were the most abundant carotenoids in the flesh, and in total, they accounted for over half of the colored carotenoids. Neoxanthin, violaxanthin, luteoxanthin, 9- cis-violaxanthin, phytoene, phytofluene, and zeta-carotene were also identified, while zeaxanthin, alpha-carotene, and lycopene were undetectable. Xanthophylls were highly esterified. On average, 1.3- and 10.8-fold higher levels of colored carotenoids were observed in the peel and flesh tissue of red-fleshed cultivars, respectively. The percentage of beta-carotene among colored carotenoids was higher in both the peel and the flesh of red-fleshed cultivars. Correlations between the levels of total colored carotenoids and the color indices were analyzed. The a* and the ratio of a*/ b* were positively correlated with the total content of colored carotenoids, while L*, b*, and H degrees correlated negatively. Vitamin A values, as retinol equivalents (RE), of loquat flesh were 0.49 and 8.77 microg/g DW (8.46 and 136.41 microg/100 g FW) on average for white- and red-fleshed cultivars, respectively. The RE values for the red-fleshed fruits were higher than fruits such as mango, red watermelon, papaya, and orange as reported in the literature, suggesting that loquat is an excellent source of provitamin A.

  14. Excited-State Deactivation of Branched Phthalocyanine Compounds.

    PubMed

    Zhu, Huaning; Li, Yang; Chen, Jun; Zhou, Meng; Niu, Yingli; Zhang, Xinxing; Guo, Qianjin; Wang, Shuangqing; Yang, Guoqiang; Xia, Andong

    2015-12-21

    The excited-state relaxation dynamics and chromophore interactions in two phthalocyanine compounds (bis- and trisphthalocyanines) are studied by using steady-state and femtosecond transient absorption spectral measurements, where the excited-state energy-transfer mechanism is explored. By exciting phthalocyanine compounds to their second electronically excited states and probing the subsequent relaxation dynamics, a multitude of deactivation pathways are identified. The transient absorption spectra show the relaxation pathway from the exciton state to excimer state and then back to the ground state in bisphthalocyanine (bis-Pc). In trisphthalocyanine (tris-Pc), the monomeric and dimeric subunits are excited and the excitation energy transfers from the monomeric vibrationally hot S1 state to the exciton state of a pre-associated dimer, with subsequent relaxation to the ground state through the excimer state. The theoretical calculations and steady-state spectra also show a face-to-face conformation in bis-Pc, whereas in tris-Pc, two of the three phthalocyanine branches form a pre-associated face-to-face dimeric conformation with the third one acting as a monomeric unit; this is consistent with the results of the transient absorption experiments from the perspective of molecular structure. The detailed structure-property relationships in phthalocyanine compounds is useful for exploring the function of molecular aggregates in energy migration of natural photosynthesis systems.

  15. The effect of feedstock additives on FCC catalyst deactivation

    SciTech Connect

    Hughes, R.; Koon, C.L.; McGhee, B.

    1995-12-31

    Fluid catalytic cracking is a major petroleum refining process and because of this the deactivation of FCC catalysts by coke deposition has been the subject of considerable investigation during the past 50 years. Nevertheless, a lack of understanding of the fundamental understanding of processes leading to coke formation still exists. Basic studies using Zeolites have usually involved excessively high levels of coke deposits compared to normal FCC operation. The present study addresses coke formation at realistic levels of 0.5 to 1.0% w/w using a standard MAT reactor in which concentrations of 1% and 10% of various additives were added to the n-hexadecane feedstock. These additives included, quinoline, phenanthrene, benzofuran, thianaphthene and indene. The coke formed was characterised by mass spectrometry and was significantly aliphatic in nature, the amount formed increasing in the order quinoline, phenanthrene, thianaphthene, benzofuran, indene. Quinoline acts primarily as a poison, whereas the other additives tend to promote coke formation in n-hexadecane cracking.

  16. Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.

    PubMed

    Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

    2011-04-07

    Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Collective Resistance in Microbial Communities by Intracellular Antibiotic Deactivation

    PubMed Central

    Sorg, Robin A.; Lin, Leo; van Doorn, G. Sander; Sorg, Moritz; Olson, Joshua; Nizet, Victor; Veening, Jan-Willem

    2016-01-01

    The structure and composition of bacterial communities can compromise antibiotic efficacy. For example, the secretion of β-lactamase by individual bacteria provides passive resistance for all residents within a polymicrobial environment. Here, we uncover that collective resistance can also develop via intracellular antibiotic deactivation. Real-time luminescence measurements and single-cell analysis demonstrate that the opportunistic human pathogen Streptococcus pneumoniae grows in medium supplemented with chloramphenicol (Cm) when resistant bacteria expressing Cm acetyltransferase (CAT) are present. We show that CAT processes Cm intracellularly but not extracellularly. In a mouse pneumonia model, more susceptible pneumococci survive Cm treatment when coinfected with a CAT-expressing strain. Mathematical modeling predicts that stable coexistence is only possible when antibiotic resistance comes at a fitness cost. Strikingly, CAT-expressing pneumococci in mouse lungs were outcompeted by susceptible cells even during Cm treatment. Our results highlight the importance of the microbial context during infectious disease as a potential complicating factor to antibiotic therapy. PMID:28027306

  18. Metabolic activation/deactivation reactions during perinatal development.

    PubMed Central

    Lucier, G W; Lui, E M; Lamartiniere, C A

    1979-01-01

    The role of metabolic activation/deactivation reactions during development is evaluated in relation to developmental pharmacology and toxicology. Enzyme systems evaluated include the mixed-function oxidases (aryl hydrocarbon hydroxylase and oxidative demethylation), epoxide hydration and conjugation (glutathione conjugation, sulfation, and glucuronidation). Placental transfer and milk secretion of chemicals are discussed in relation to maternal, placental, and fetal metabolism. Normal patterns of enzyme development can be modified in two ways: (1) enzyme induction and (2) enzyme imprinting. Postnatal induction of the mixed-function oxidases and glucuronyl-transferase following treatment of pregnant rats with TCDD is shown to be caused primarily by newborn exposure to TCDD in milk. Structure-activity relationship are defined for the perinatal induction of hepatic enzymes by the pure PCBs. PCBs are divided into two classes: P-450 inducers and P-448 inducers. Imprinting or programming of hepatic metabolism is a function of the sexual differentiation of enzyme activity; male and female activities are similar in prepubertal animals, whereas pronounced sex differences are evident in adults. Treatment of newborn rats (days 2--6) with diethystilbestrol or testosterone resulted in a feminization (decrease) of mixed-function oxidation and glucuronidation in adult males. No changes were seen in immature males or females or adult females. This effect appears to be irreversible and is under pituitary-hypothalamic-gonadal control. In addition to the feminization of enzyme activity, neonatal exposure to hormonally active chemicals also feminizes the hepatic response to cadmium in resultant adult animals. PMID:510244

  19. Selection and taxonomic identification of carotenoid-producing marine actinomycetes.

    PubMed

    Romero, Francisco; Fernández-Chimeno, Rosa Isabel; de la Fuente, Juan Luis; Barredo, José-Luis

    2012-01-01

    Carotenoids are important pigments produced by plants and many microorganisms, including fungi, microalgae, cyanobacteria, and bacteria. Marine actinomycetes are a group of bacteria that produce a variety of metabolites with economic potential. Here, we describe a general method of selecting marine actinomycetes as carotenoids' producers. The screening is carried out at two levels: the first one involves a quick selection of strains by visual color inspection, and the second consists in the analysis of the extracts by HPLC. The taxonomic analysis of the producing strains gives us an overview of the groups of actinomycetes in which carotenoids can be found.

  20. Carotenoid cation formation and the regulation of photosynthetic light harvesting.

    PubMed

    Holt, Nancy E; Zigmantas, Donatas; Valkunas, Leonas; Li, Xiao-Ping; Niyogi, Krishna K; Fleming, Graham R

    2005-01-21

    Photosynthetic light harvesting in excess light is regulated by a process known as feedback deexcitation. Femtosecond transient absorption measurements on thylakoid membranes show selective formation of a carotenoid radical cation upon excitation of chlorophyll under conditions of maximum, steady-state feedback deexcitation. Studies on transgenic Arabidopsis thaliana plants confirmed that this carotenoid radical cation formation is correlated with feedback deexcitation and requires the presence of zeaxanthin, the specific carotenoid synthesized during high light exposure. These results indicate that energy transfer from chlorophyll molecules to a chlorophyllzeaxanthin heterodimer, which then undergoes charge separation, is the mechanism for excess energy dissipation during feedback deexcitation.

  1. Voltage-dependent absorbance change of carotenoids in halophilic archaebacteria.

    PubMed

    Seki, S I; Sasabe, H; Tomioka, H

    1996-10-02

    Membrane vesicles of wild-type Halobacterium sp. mex strain show a wavy absorbance change which has not been so far reported in halophilic archaebacteria. A white mutant strain lacking carotenoids did not show the wavy absorbance change. The wavy absorbance change in the range of 440-590 nm was induced by a red flash (600-640 nm), which photoexcited electrogenic ion pumps, mex bacteriorhodopsin and mex halorhodopsin but not carotenoids. The wavy change was also caused by K+ diffusion potentials without light. These results suggest that the wavy absorbance change in the membrane vesicles is the voltage-dependent absorbance change of the carotenoids.

  2. Carotenoid Composition of the Fruit of Red Mamey (Pouteria sapota).

    PubMed

    Murillo, Enrique; Turcsi, Erika; Szabó, Ildikó; Mosquera, Yesuri; Agócs, Attila; Nagy, Veronika; Gulyás-Fekete, Gergely; Deli, József

    2016-09-28

    The detailed carotenoid analysis of red mamey (Pouteria sapota) was achieved by HPLC-DAD-MS, chemical tests, and cochromatography with authentic samples. Altogether 47 components were detected and 34 identified from the total extract or after fractionation with column chromatography. The main carotenoids were cryptocapsin, sapotexanthin, and capsanthin 5,6-epoxide. Some further minor components containing the κ-end group with or without a hydroxy group and their 5,6-epoxy precursors were identified. Some comments are made about the biosynthesis of κ-carotenoids in red mamey.

  3. Dual multichannel optical wavelet transform processor

    NASA Astrophysics Data System (ADS)

    Feng, Wenyi; Yan, Yingbai; Jin, Guofan; Wu, Minxian; He, Qingsheng

    1999-10-01

    Based on the theory of volume holographic associative storage in a photorefractive crystal and that of binary optics, a compact dual multichannel optical wavelet transform processor is proposed and constructed. Both wavelet correlation and wavelet transform can be complemented by the system. Multi-pattern channels are achieved by the inherent parallelism of volume holographic storage. Angle multiplexed holograms of wavelet filtered pattern images are recorded in the crystal Multi-wavelet channels are accomplished by a Dammann grating, which is a binary optical element for spectrum duplication. The grating is adopted to generate a set of channels with different wavelet filters. Wavelet correlation peaks in different wavelet channels are synthesized to improve the recognition accuracy by multiplication pixel by pixel. Wavelet transform results in different wavelet channels are stored in the crystal and can be restored for recognition or segmentation. The application of the system in human face recognition is studied.

  4. Photonic generation for multichannel THz wireless communication.

    PubMed

    Shams, Haymen; Fice, Martyn J; Balakier, Katarzyna; Renaud, Cyril C; van Dijk, Frédéric; Seeds, Alwyn J

    2014-09-22

    We experimentally demonstrate photonic generation of a multichannel THz wireless signal at carrier frequency 200 GHz, with data rate up to 75 Gbps in QPSK modulation format, using an optical heterodyne technique and digital coherent detection. BER measurements were carried out for three subcarriers each modulated with 5 Gbaud QPSK or for two subcarriers modulated with 10 Gbaud QPSK, giving a total speed of 30 Gbps or 40 Gbps, respectively. The system evaluation was also performed with three subcarriers modulated with 12.5 Gbaud QPSK (75 Gbps total) without and with 40 km fibre transmission. The proposed system enhances the capacity of high-speed THz wireless transmission by using spectrally efficient modulated subcarriers spaced at the baud rate. This approach increases the overall transmission capacity and reduces the bandwidth requirement for electronic devices.

  5. Fault analysis of multichannel spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Dugal-Whitehead, Norma R.; Lollar, Louis F.

    1990-01-01

    The NASA Marshall Space Flight Center proposes to implement computer-controlled fault injection into an electrical power system breadboard to study the reactions of the various control elements of this breadboard. Elements under study include the remote power controllers, the algorithms in the control computers, and the artificially intelligent control programs resident in this breadboard. To this end, a study of electrical power system faults is being performed to yield a list of the most common power system faults. The results of this study will be applied to a multichannel high-voltage DC spacecraft power system called the large autonomous spacecraft electrical power system (LASEPS) breadboard. The results of the power system fault study and the planned implementation of these faults into the LASEPS breadboard are described.

  6. Fault analysis of multichannel spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Dugal-Whitehead, Norma R.; Lollar, Louis F.

    1990-01-01

    The NASA Marshall Space Flight Center proposes to implement computer-controlled fault injection into an electrical power system breadboard to study the reactions of the various control elements of this breadboard. Elements under study include the remote power controllers, the algorithms in the control computers, and the artificially intelligent control programs resident in this breadboard. To this end, a study of electrical power system faults is being performed to yield a list of the most common power system faults. The results of this study will be applied to a multichannel high-voltage DC spacecraft power system called the large autonomous spacecraft electrical power system (LASEPS) breadboard. The results of the power system fault study and the planned implementation of these faults into the LASEPS breadboard are described.

  7. Subchromoplast Sequestration of Carotenoids Affects Regulatory Mechanisms in Tomato Lines Expressing Different Carotenoid Gene Combinations[C][W

    PubMed Central

    Nogueira, Marilise; Mora, Leticia; Enfissi, Eugenia M.A.; Bramley, Peter M.; Fraser, Paul D.

    2013-01-01

    Metabolic engineering of the carotenoid pathway in recent years has successfully enhanced the carotenoid contents of crop plants. It is now clear that only increasing biosynthesis is restrictive, as mechanisms to sequestrate these increased levels in the cell or organelle should be exploited. In this study, biosynthetic pathway genes were overexpressed in tomato (Solanum lycopersicum) lines and the effects on carotenoid formation and sequestration revealed. The bacterial Crt carotenogenic genes, independently or in combination, and their zygosity affect the production of carotenoids. Transcription of the pathway genes was perturbed, whereby the tissue specificity of transcripts was altered. Changes in the steady state levels of metabolites in unrelated sectors of metabolism were found. Of particular interest was a concurrent increase of the plastid-localized lipid monogalactodiacylglycerol with carotenoids along with membranous subcellular structures. The carotenoids, proteins, and lipids in the subchromoplast fractions of the transgenic tomato fruit with increased carotenoid content suggest that cellular structures can adapt to facilitate the sequestration of the newly formed products. Moreover, phytoene, the precursor of the pathway, was identified in the plastoglobule, whereas the biosynthetic enzymes were in the membranes. The implications of these findings with respect to novel pathway regulation mechanisms are discussed. PMID:24249831

  8. Wireless multichannel electroencephalography in the newborn.

    PubMed

    Ibrahim, Z H; Chari, G; Abdel Baki, S; Bronshtein, V; Kim, M R; Weedon, J; Cracco, J; Aranda, J V

    2016-01-01

    First, to determine the feasibility of an ultra-compact wireless device (microEEG) to obtain multichannel electroencephalographic (EEG) recording in the Neonatal Intensive Care Unit (NICU). Second, to identify problem areas in order to improve wireless EEG performance. 28 subjects (gestational age 24-30 weeks, postnatal age <30 days) were recruited at 2 sites as part of an ongoing study of neonatal apnea and wireless EEG. Infants underwent 8-9 hour EEG recordings every 2-4 weeks using an electrode cap (ANT-Neuro) connected to the wireless EEG device (Bio-Signal Group). A 23 electrode configuration was used incorporating the International 10-20 System. The device transmitted recordings wirelessly to a laptop computer for bedside assessment. The recordings were assessed by a pediatric neurophysiologist for interpretability. A total of 84 EEGs were recorded from 28 neonates. 61 EEG studies were obtained in infants prior to 35 weeks corrected gestational age (CGA). NICU staff placed all electrode caps and initiated all recordings. Of these recordings 6 (10%) were uninterpretable due to artifacts and one study could not be accessed. The remaining 54 (89%) EEG recordings were acceptable for clinical review and interpretation by a pediatric neurophysiologist. Of the recordings obtained at 35 weeks corrected gestational age or later only 11 out of 23 (48%) were interpretable. Wireless EEG devices can provide practical, continuous, multichannel EEG monitoring in preterm neonates. Their small size and ease of use could overcome obstacles associated with EEG recording and interpretation in the NICU.

  9. Wireless multichannel electroencephalography in the newborn

    PubMed Central

    Ibrahim, Z.H.; Chari, G.; Abdel Baki, S.; Bronshtein, V.; Kim, M.R.; Weedon, J.; Cracco, J.; Aranda, J.V.

    2016-01-01

    OBJECTIVES: First, to determine the feasibility of an ultra-compact wireless device (microEEG) to obtain multichannel electroencephalographic (EEG) recording in the Neonatal Intensive Care Unit (NICU). Second, to identify problem areas in order to improve wireless EEG performance. STUDY DESIGN: 28 subjects (gestational age 24–30 weeks, postnatal age <30 days) were recruited at 2 sites as part of an ongoing study of neonatal apnea and wireless EEG. Infants underwent 8-9 hour EEG recordings every 2–4 weeks using an electrode cap (ANT-Neuro) connected to the wireless EEG device (Bio-Signal Group). A 23 electrode configuration was used incorporating the International 10–20 System. The device transmitted recordings wirelessly to a laptop computer for bedside assessment. The recordings were assessed by a pediatric neurophysiologist for interpretability. RESULTS: A total of 84 EEGs were recorded from 28 neonates. 61 EEG studies were obtained in infants prior to 35 weeks corrected gestational age (CGA). NICU staff placed all electrode caps and initiated all recordings. Of these recordings 6 (10%) were uninterpretable due to artifacts and one study could not be accessed. The remaining 54 (89%) EEG recordings were acceptable for clinical review and interpretation by a pediatric neurophysiologist. Of the recordings obtained at 35 weeks corrected gestational age or later only 11 out of 23 (48%) were interpretable. CONCLUSIONS: Wireless EEG devices can provide practical, continuous, multichannel EEG monitoring in preterm neonates. Their small size and ease of use could overcome obstacles associated with EEG recording and interpretation in the NICU. PMID:28009337

  10. Theoretical investigation of carotenoid ultraviolet spectra

    NASA Astrophysics Data System (ADS)

    Martins, João B. L.; Durães, Jussara A.; Sales, Maria J. A.; Vilela, Alessandra F. A.; E Silva, Geraldo M.; Gargano, Ricardo

    We have determined the π band-gaps of the main carotenoids present in poly(methyl)methacrylate/buriti blends, namely, trans-β-carotene, 13-cis-β-carotene, 9-cis-β-carotene, phytofluene, and zeaxanthin. Semiempirical, model Hamiltonian, and density functional calculations were carried out to study these structures. The geometries were fully optimized using AM1, PM3, and B3LYP/6-31G(d,p) methods. The TD-DFT and ZINDO/S methods were applied for the calculation of the electronic absorption spectra of the optimized B3LYP geometries. The calculated spectra using the polarizable continuum model for the solvent effects were compared with the available experimental.

  11. Deactivation and decommissioning environmental strategy for the Plutonium Finishing Plant (PFP) Complex Hanford Nuclear Reservation

    SciTech Connect

    HOPKINS, A.M.

    2003-02-01

    The overall goal of this strategy is to comply with all applicable environmental laws and regulations and/or compliance agreements during Plutonium Finishing Plant (PFP) stabilization, deactivation, and eventual dismantlement.

  12. Williams deactivates the CHeCS in the U.S. Laboratory during Expedition 13

    NASA Image and Video Library

    2006-06-13

    ISS013-E-36887 (13 June 2006) --- Astronaut Jeffrey N. Williams, Expedition 13 NASA space station science officer and flight engineer, deactivates the Crew Health Care System (CHeCS) rack in the Destiny laboratory of the International Space Station.

  13. Charge separation technique for metal-oxide-silicon capacitors in the presence of hydrogen deactivated dopants

    SciTech Connect

    Witczak, Steven C.; Winokur, Peter S.; Lacoe, Ronald C.; Mayer, Donald C.

    2000-06-01

    An improved charge separation technique for metal-oxide-silicon (MOS) capacitors is presented which accounts for the deactivation of substrate dopants by hydrogen at elevated irradiation temperatures or small irradiation biases. Using high-frequency capacitance-voltage measurements, radiation-induced inversion voltage shifts are separated into components due to oxide trapped charge, interface traps, and deactivated dopants, where the latter is computed from a reduction in Si capacitance. In the limit of no radiation-induced dopant deactivation, this approach reduces to the standard midgap charge separation technique used widely for the analysis of room-temperature irradiations. The technique is demonstrated on a p-type MOS capacitor irradiated with {sup 60}Co {gamma} rays at 100 degree sign C and zero bias, where the dopant deactivation is significant.(c) 2000 American Institute of Physics.

  14. Integrated Project Management Planning for the Deactivation of the Savannah River Site F-Canyon Complex

    SciTech Connect

    Clark, T.G.

    2000-12-01

    This paper explains the planning process that is being utilized by the Westinghouse Savannah River Company to take the F-Canyon Complex facilities from operations to a deactivated condition awaiting final decommissioning.

  15. Patient perceptions of implantable cardioverter-defibrillator deactivation discussions: A qualitative study.

    PubMed

    MacIver, Jane; Tibbles, Alana; Billia, Filio; Ross, Heather

    2016-01-01

    There is a class I recommendation for implantable cardioverter-defibrillator deactivation discussions to occur between physicians and heart failure patients. Few studies have reported the patient's perspective on the timing of implantable cardioverter-defibrillator deactivation discussions. To determine patient awareness, preferences and timing of implantable cardioverter-defibrillator deactivation discussions. Grounded theory was used to collect and analyze interview data from 25 heart failure patients with an implantable cardioverter-defibrillator. Patients with an implantable cardioverter-defibrillator, from the Heart Function Clinic at University Health Network (Toronto, Canada). The sample (n = 25) was predominately male (76%) with an average age of 62 years. Patients identified three stages where they felt implantable cardioverter-defibrillator deactivation should be discussed: (1) prior to implantation, (2) with any significant deterioration but while they were of sound mind to engage in and communicate their preferences and (3) at end of life, where patients wished further review of their previously established preferences and decisions about implantable cardioverter-defibrillator deactivation. Most patients (n = 17, 68%) said they would consider deactivation, six (24%) were undecided and two (8%) were adamant they would never turn it off. The patient preferences identified in this study support the need to include information on implantable cardioverter-defibrillator deactivation at implant, with change in clinical status and within broader discussions about end-of-life treatment preferences. Using this process to help patients determine and communicate their implantable cardioverter-defibrillator deactivation preferences may reduce the number of patients experiencing distressing implantable cardioverter-defibrillator shocks at end of life.

  16. Patient perceptions of implantable cardioverter-defibrillator deactivation discussions: A qualitative study

    PubMed Central

    MacIver, Jane; Tibbles, Alana; Billia, Filio; Ross, Heather

    2016-01-01

    Background: There is a class I recommendation for implantable cardioverter-defibrillator deactivation discussions to occur between physicians and heart failure patients. Few studies have reported the patient’s perspective on the timing of implantable cardioverter-defibrillator deactivation discussions. Aim: To determine patient awareness, preferences and timing of implantable cardioverter-defibrillator deactivation discussions. Design: Grounded theory was used to collect and analyze interview data from 25 heart failure patients with an implantable cardioverter-defibrillator. Setting and participants: Patients with an implantable cardioverter-defibrillator, from the Heart Function Clinic at University Health Network (Toronto, Canada). Results: The sample (n = 25) was predominately male (76%) with an average age of 62 years. Patients identified three stages where they felt implantable cardioverter-defibrillator deactivation should be discussed: (1) prior to implantation, (2) with any significant deterioration but while they were of sound mind to engage in and communicate their preferences and (3) at end of life, where patients wished further review of their previously established preferences and decisions about implantable cardioverter-defibrillator deactivation. Most patients (n = 17, 68%) said they would consider deactivation, six (24%) were undecided and two (8%) were adamant they would never turn it off. Conclusion: The patient preferences identified in this study support the need to include information on implantable cardioverter-defibrillator deactivation at implant, with change in clinical status and within broader discussions about end-of-life treatment preferences. Using this process to help patients determine and communicate their implantable cardioverter-defibrillator deactivation preferences may reduce the number of patients experiencing distressing implantable cardioverter-defibrillator shocks at end of life. PMID:27110361

  17. Dopamine Transporters in Striatum Correlated with Deactivation in the Default Mode Network during Visuospatial Attention

    SciTech Connect

    Tomasi, D.; Fowler, J.; Tomasi, D.; Volkow, N.D.; Wang, R.L.; Telang, F.; Wang, Chang, L.; Ernst, T.; /Fowler, J.S.

    2009-06-01

    Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [{sup 11}C]cocaine used as DAT radiotracer) and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging) in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7) and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32). With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness) and cingulate gyrus (region deactivated in proportion to emotional interference). These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT) in inattention reflect in part their ability to facilitate the deactivation of the DMN.

  18. Neurosteroid prolongs GABAA channel deactivation by altering kinetics of desensitized states.

    PubMed

    Zhu, W J; Vicini, S

    1997-06-01

    Fast applications of GABA (1 mM) to nucleated and outside-out patches excised from granule neurons in cerebellar slices from developing rats evoked currents with a double exponential time course reminiscent of that of IPSCs. A neurosteroid 3alpha, 21dihydroxy-5alpha-pregnan-20-one (THDOC) remarkably increased the slow deactivation time constant and slowed down recovery from desensitization, as estimated by paired-pulse GABA applications. THDOC also reduced the amplitude of GABA currents, whereas it failed to affect the fast deactivation component and its relative contribution to peak amplitude. The effects of THDOC on slow deactivation were greater in rats younger than postnatal day 13 (P13) as compared with rats at P30-P35. THDOC failed to alter deactivation of short responses induced by a less-potent agonist taurine at saturating doses. These responses had deactivation kinetics described by a fast single exponential decay, little desensitization, and quick recovery. However, THDOC slowed deactivation if taurine responses were long enough to allow consistent desensitization, suggesting that desensitized states are required for the neurosteroid to modulate GABA responses. In outside-out patches, just as desensitized states prolonged GABA responses by producing reopening of channels activated by brief GABA pulses, THDOC increased the channel open probability by further increasing the number of late channel openings, resulting in a prolongation of the slow deactivation. Our data suggest that neurosteroid potentiates the inhibitory postsynaptic transmission via the prolongation of the slow deactivation and that the alteration of kinetics of entry and exit from desensitized states underlies the allosteric modification of GABAA receptors by neurosteroids.

  19. Subcellular Localization of Carotenoid Biosynthesis in Synechocystis sp. PCC 6803

    PubMed Central

    Selstam, Eva; Norling, Birgitta

    2015-01-01

    The biosynthesis pathway of carotenoids in cyanobacteria is partly described. However, the subcellular localization of individual steps is so far unknown. Carotenoid analysis of different membrane subfractions in Synechocystis sp. PCC6803 shows that “light” plasma membranes have a high carotenoid/protein ratio, when compared to “heavier” plasma membranes or thylakoids. The localization of CrtQ and CrtO, two well-defined carotenoid synthesis pathway enzymes in Synechocystis, was studied by epitope tagging and western blots. Both enzymes are locally more abundant in plasma membranes than in thylakoids, implying that the plasma membrane has higher synthesis rates of β-carotene precursor molecules and echinenone. PMID:26083372

  20. Carotenoids from guava (Psidium guajava l.): isolation and structure elucidation.

    PubMed

    Mercadante, A Z; Steck, A; Pfander, H

    1999-01-01

    Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV-visible, 400 and 500 MHz (1)H NMR, 120 and 125 MHz (13)C NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-beta-carotene, (all-E)-gamma-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-beta-cryptoxanthin, (all-E, 3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3'R, 6'R)-lutein, (all-E,3S,5R,6R,3'S,5'R,8'R)-, and (all-E,3S,5R,6R,3'S, 5'R,8'S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time.

  1. Anticancer properties of carotenoids in prostate cancer. A review.

    PubMed

    Soares, Nathalia da Costa Pereira; Teodoro, Anderson Junger; Lotsch, Priscila Falagan; Granjeiro, José Mauro; Borojevic, Radovan

    2015-10-01

    Prostate cancer is the most common noncutaneous cancer of men in the world. Several epidemiological studies have linked increased carotenoids consumption with decreased prostate cancer risk. These findings are supported by in vitro and in vivo experiments showing that carotenoids not only enhance the antioxidant response of prostate cells, but that they are able to inhibit proliferation, induce apoptosis and decrease the metastatic capacity of prostate cancer cells. However, clear clinical evidence supporting the use of carotenoids in prevention or treatment of prostate cancer is not available, due to the limited number of published randomized clinical trials, and the varying protocols used in the existing studies. The scope of the present review is to discuss the potential impact of carotenoids on prostate cancer by giving an overview of the molecular mechanisms and in vitro / in vivo effects.

  2. Effects of exogenous glucose on carotenoid accumulation in tomato leaves.

    PubMed

    Mortain-Bertrand, Anne; Stammitti, Linda; Telef, Nadège; Colardelle, Patrice; Brouquisse, Renaud; Rolin, Dominique; Gallusci, Philippe

    2008-10-01

    To investigate the effect of carbohydrate on carotenoid accumulation in leaves, excised plants of tomato (Lycopersicum esculentum var. cerasiformae, wva 106) were supplied with glucose through the transpiration stream for 48 h. We report here that sugar accumulation in leaves led to a decrease of carotenoid content, which was related to the reduction of Chl. The decrease in carotenoid amount correlated with a sugar-induced repression of genes encoding enzymes of the carotenoid and of the Rohmer pathways. The lower 1-deoxy-D-xylulose-5-phosphate synthase transcript level probably leads to a decreased metabolic flux through the methylerythritol pathway and subsequently to a lower amount of substrate available for plastidic isoprenoid synthesis. Differences between responses of young (sink) and mature (source) leaves to carbohydrate accumulation are discussed.

  3. Maternally invested carotenoids compensate costly ectoparasitism in the hihi

    PubMed Central

    Ewen, John G.; Thorogood, Rose; Brekke, Patricia; Cassey, Phillip; Karadas, Filiz; Armstrong, Doug P.

    2009-01-01

    Dietary ingested carotenoid biomolecules have been linked to both improved health and immunity in nestling birds. Here, we test whether maternally invested egg carotenoids can offset the cost of parasitism in developing nestling hihi (Notiomystis cincta) from the bloodsucking mite (Ornithonyssus bursa). Our results reveal clear negative effects of parasitism on nestlings, and that maternally derived carotenoids compensate this cost, resulting in growth parameters and ultimate mass achieved being similar to nonparasitized young. Our results offer an unique example of a direct positive relationship between enhanced maternal investment of carotenoids and an ability to cope with a specific and costly parasite in young birds. As O. bursa infestations reduce population viability in hihi, our findings also highlight the importance of key nutritional resources for endangered bird populations to better cope with common parasite infestations. PMID:19620733

  4. Enzymic Pathways for Formation of Carotenoid Cleavage Products

    NASA Astrophysics Data System (ADS)

    Fleischmann, Peter; Zorn, Holger

    Degraded carotenoids (apocarotenoids, norisoprenoids) have been a subject of intensive research for several decades. From the perspective of human physiology and nutrition, the retinoids, acting as vitamins, signalling molecules, and visual pigments, attracted the greatest attention (Chapters 15 and 16). Plant scientists, however, detected a wealth of different apocarotenoids, presumably derived by the excentric cleavage of carotenoids in various species, the plant hormone abscisic acid (1, Scheme 6) being the best-investigated example. With the onset of fruit ripening, flower opening or senescence of green tissues, carotenoids are degraded oxidatively to smaller, volatile compounds. The natural biological functions of the reaction products are outlined in Chapter 15. As many of these apocarotenoids act as potent flavour compounds, food chemists and flavourists worldwide have investigated meticulously their structural and sensory properties. Many aspects of carotenoid metabolites and breakdown products as aroma compounds are presented in a comprehensive book [1].

  5. Deactivation of Highly Vibrationally Excited OH by O Atoms

    NASA Astrophysics Data System (ADS)

    Copeland, R. A.; Smith, G. P.; Mlynczak, M. M.; Kalogerakis, K. S.

    2006-12-01

    small amounts of other efficient collider gases are added. The steady- state population of OH(υ = 8 and 9) depends on the relative amount of O atoms with respect to other gases that deactivate these OH levels rapidly. Given that the rate coefficients for deactivation of OH(υ = 8 and 9) by CO2 is known [2,3], we can determine the rate coefficients for OH(υ = 8 and 9) + O with respect to that for OH(υ = 8 and 9) + CO2. Preliminary experiments indicate a total removal rate coefficient for OH(υ = 9) by O atoms exceeding 1 × 10^{-10} cm3s-1. We will present our results and discuss their atmospheric implications. This work was supported by the NASA Geospace Sciences and Planetary Atmospheres Programs. [1] A. D. Sappey, and R.A. Copeland, J. Chem. Phys. 93, 5741 (1990). [2] M. J. Dyer, K. Knutsen, and R.A. Copeland, J. Chem. Phys. 107, 7809 (1997). [3] B. R. Chalamala and R.A. Copeland, J. Chem. Phys. 99, 5807 (1993).

  6. Enhancement of coupled multichannel images using sparsity constraints.

    PubMed

    Ramakrishnan, Naveen; Ertin, Emre; Moses, Randolph L

    2010-08-01

    We consider the problem of joint enhancement of multichannel images with pixel based constraints on the multichannel data. Previous work by Cetin and Karl introduced nonquadratic regularization methods for SAR image enhancement using sparsity enforcing penalty terms. We formulate an optimization problem that jointly enhances complex-valued multichannel images while preserving the cross-channel information, which we include as constraints tying the multichannel images together. We pose this problem as a joint optimization problem with constraints. We first reformulate it as an equivalent (unconstrained) dual problem and develop a numerically-efficient method for solving it. We develop the Dual Descent method, which has low complexity, for solving the joint optimization problem. The algorithm is applied to both an interferometric synthetic aperture radar (IFSAR) problem, in which the relative phase between two complex-valued images indicate height, and to a synthetic multimodal medical image example.

  7. Multichannel ECG data compression based on multiscale principal component analysis.

    PubMed

    Sharma, L N; Dandapat, S; Mahanta, Anil

    2012-07-01

    In this paper, multiscale principal component analysis (MSPCA) is proposed for multichannel electrocardiogram (MECG) data compression. In wavelet domain, principal components analysis (PCA) of multiscale multivariate matrices of multichannel signals helps reduce dimension and remove redundant information present in signals. The selection of principal components (PCs) is based on average fractional energy contribution of eigenvalue in a data matrix. Multichannel compression is implemented using uniform quantizer and entropy coding of PCA coefficients. The compressed signal quality is evaluated quantitatively using percentage root mean square difference (PRD), and wavelet energy-based diagnostic distortion (WEDD) measures. Using dataset from CSE multilead measurement library, multichannel compression ratio of 5.98:1 is found with PRD value 2.09% and the lowest WEDD value of 4.19%. Based on, gold standard subjective quality measure, the lowest mean opinion score error value of 5.56% is found.

  8. Deactivating Cochlear Implant Electrodes Based on Pitch Information for Users of the ACE Strategy.

    PubMed

    Vickers, Deborah; Degun, Aneeka; Canas, Angela; Stainsby, Thomas; Vanpoucke, Filiep

    2016-01-01

    There is a wide range in performance for cochlear implant (CI) users and there is some evidence to suggest that implant fitting can be modified to improve performance if electrodes that do not provide distinct pitch information are de-activated. However, improvements in performance may not be the same for users of all CI devices; in particular for those with Cochlear devices using n-of-m strategies (ACE or SPEAK).The goal of this research was to determine for users of Cochlear devices (CP810 or CP900 series processors) if speech perception could be improved when indiscriminable electrodes were de-activated and this was also compared to when the same number of discriminable electrodes were de-activated.A cross-over study was conducted with 13 adult CI users who received experimental maps with de-activated channels for a minimum of 2 months and these were compared to optimised clinical maps.The findings showed that there were no significant benefits of electrode de-activation on speech perception and that there was a significant deterioration in spectro-temporal ripple perception when electrodes were switched off. There were no significant differences between de-activation of discriminable or indiscriminable electrodes.These findings suggest that electrode de-activation with n-of-m strategies may not be beneficial.

  9. Regulation of GIRK channel deactivation by Galpha(q) and Galpha(i/o) pathways.

    PubMed

    Mark, M D; Ruppersberg, J P; Herlitze, S

    2000-09-01

    G protein regulated inward rectifying potassium channels (GIRKs) are activated by G protein coupled receptors (GPCRs) via the G protein betagamma subunits. However, little is known about the effects of different GPCRs on the deactivation kinetics of transmitter-mediated GIRK currents. In the present study we investigated the influence of different GPCRs in the presence and absence of RGS proteins on the deactivation kinetics of GIRK channels by coexpressing the recombinant protein subunits in Xenopus oocytes. The stimulation of both G(i/o)- and G(q)-coupled pathways accelerated GIRK deactivation. GIRK currents deactivated faster upon stimulation of G(i/o)- and G(q)-coupled pathways by P(2)Y(2) receptors (P(2)Y(2)Rs) than upon activation of the G(i/o)-coupled pathway alone via muscarinic acetylcholine receptor M2 (M(2) mAChRs). This acceleration was found to be dependent on phospholipase C (PLC) and protein kinase C (PKC) activities and intracellular calcium. With the assumption that RGS2 has a higher affinity for Galpha(q) than Galpha(i/o), we demonstrated that the deactivation kinetics of GIRK channels can be differentially regulated by the relative amount of RGS proteins. These data indicate that transmitter-mediated deactivation of GIRK currents is modulated by crosstalk between G(i/o)- and G(q)-coupled pathways.

  10. Conversion of Biomass-Derived Small Oxygenates over HZSM-5 and its Deactivation Mechanism

    SciTech Connect

    Ramasamy, Karthikeyan K.; Gerber, Mark A.; Flake, Matthew D.; Zhang, He; Wang, Yong

    2014-02-28

    HZSM-5 catalyst deactivation was studied using aqueous feed mixtures containing ethanol, ethanol+ acetic acid, ethanol+ethyl acetate, or ethanol+acetaldehyde in a fixed bed reactor at 360°C and 300psig. Compared to ethanol alone experiment, addition of other oxygenates reduced catalyst life in the order of: ethyl acetatedeactivate the catalyst through a pore-blocking mechanism. Acetic acid deactivates the catalyst through an active site poisoning mechanism or strong adsorption of acetate intermediates on the active sites (hydroxyl groups). Ethanol deactivates the catalyst primarily through its pore-blocking mechanism, but the rate of ethanol deactivation is orders of magnitude slower than that of acetaldehyde. Ethyl acetate hydrolyzes to form acetic acid and ethanol which deactivate the catalyst through its respective mechanisms. In addition, each functional group of oxygenates requires different active sites/catalysts and different operating conditions due to competitive adsorptions on active sites for their conversion to the desired products. Therefore, it is necessary to pre-treat the mixture of oxygenates to produce a feed stream containing the same or similar functional group compounds before converting the feed stream to hydrocarbon compounds over HZSM-5 catalyst.

  11. FACILITY DEACTIVATION AND DECOMMISSIONING AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Gilmour, J; William Austin, W; Cathy Sizemore, C

    2007-01-31

    In February 2002, the U.S. Department of Energy initiated actions to expedite Cleanup, focus on significant and early risk reduction, and reduce costs at the Savannah River Site (SRS). In response SRS started on a project focused on completing the decommissioning of inactive facilities in T, D, and M Areas, areas that on the perimeter of the Site, by the end of 2006. In June 2003, the Department of Energy Savannah River Operations Office (DOE-SR), the South Carolina Department of Health and Environmental Control (SCDHEC), and the Environmental Protection Agency, Region 4 (EPA-4) endorsed a Memorandum of Agreement (MOA) concerning cleanup at the Savannah River Site (SRS). The vision of the Agreement is that SRS will reduce its operations footprint to establish a buffer zone at the perimeter if the Site, while the central core area of the Site will be reserved for continuing or future long-term operations. DOE-SR, EPA-4, and SCDHEC agreed that establishing this buffer zone and appropriately sequencing environmental restoration and decommissioning activities can lead to greater efficiency and accelerate completion of entire site areas. This vision is embodied in the concept of Area Completion--which integrated operations, deactivation and decommissioning (D&D), and soils and groundwater cleanup into a time-phased approach to completing all the work necessary to address the Cold War legacy. D&D addresses the ''footprint'' of the building or structure, while the soils and groundwater project addresses any environmental remediation that may be required in the underlying and surrounding soils and groundwater. Since then, {approx}250 facilities have been decommissioned at the SRS, ranging from guard stations to nuclear fuel production facilities.

  12. DEACTIVATION AND DECOMMISSIONING (D AND D) TECHNOLOGY INTEGRATION

    SciTech Connect

    M.A. Ebadian, Ph.D.

    1999-01-01

    As part of the ongoing task of making Deactivation and Decommissioning (D&D) operations more efficient, this subtask has addressed the need to integrate existing characterization technologies with decontamination technologies in order to provide real-time data on the progress of contamination removal. Specifically, technologies associated with concrete decontamination and/or removal have been examined with the goal of integrating existing technologies and commercializing the resulting hybrid. The Department of Energy (DOE) has estimated that 23 million cubic meters of concrete will require disposition as 1200 buildings undergo the D&D process. All concrete removal to be performed will also necessitate extensive use of characterization techniques. The in-process characterization presents the most potential for improvement and cost-savings as compared to other types. Current methods for in-process characterization usually require cessation of work to allow for radiation surveys to assess the rate of decontamination. Combining together decontamination and characterization technologies would allow for in-process evaluation of decontamination efforts. Since the present methods do not use in-process evaluations for the progress of decontamination, they may allow for ''overremoval'' of materials (removal of contaminated along with non-contaminated materials). Overremoval increases the volume of waste and therefore the costs associated with disposal. Integrating technologies would facilitate the removal of only contaminated concrete and reduce the total volume of radioactive waste, which would be disposed of. This would eventually ensure better productivity and time savings. This project presents a general procedure to integrate the above-mentioned technologies in the form of the Technology Integration Module (TIM) along with combination lists of commercially available decontamination and characterization technologies. The scope of the project has also been expanded by FIU

  13. No detectable carotenoid concentrations in serum of llamas and alpacas.

    PubMed

    Raila, J; Schweigert, F J; Stanitznig, A; Lambacher, B; Franz, S; Baldermann, S; Wittek, T

    2016-11-09

    Carotenoids are lipid-soluble pigments and important for a variety of physiological functions. They are major dietary vitamin A precursors and act as lipophilic antioxidants in a variety of tissues and are associated with important health benefits in humans and animals. All animals must acquire carotenoids from their diet, but to our knowledge, there are no studies investigating the intestinal carotenoid absorption and their blood concentrations in New World camelids. The present study aimed to assess the serum concentrations of selected carotenoids in llamas (n = 13) and alpacas (n = 27). Serum carotenoids as well as retinol (vitamin A) and α-tocopherol (vitamin E) were determined by high-performance liquid chromatography coupled with mass spectrometry and these were unable to detect any carotenoids (α- and β-carotene, α- and β-cryptoxanthin, lutein, zeaxanthin, lycopene) in the samples. The concentrations of retinol in alpacas (2.89 ± 1.13 μmol/l; mean ± SD) were higher (p = 0.024) than those found in llamas (2.05 ± 0.87 μmol/l); however, the concentrations of α-tocopherol were not significantly (p = 0.166) different (llamas: 3.98 ± 1.83 μmol/l; alpacas: 4.95 ± 2.14 μmol/l). The results show that both llamas and alpacas are not able to absorb intact carotenoids, but efficiently convert provitamin A carotenoids to retinol.

  14. Skin total carotenoids predict plasma carotenoid levels during a 28-week experimental feeding study with varying levels of vegetables and fruit

    USDA-ARS?s Scientific Manuscript database

    Objective biomarkers are needed to assess adherence to vegetable and fruit intervention trials. This study compared plasma carotenoid concentrations to non-invasive skin carotenoid assessments. Thirty participants consumed a low-carotenoid diet (6 wk, Phases 1 & 3), a provided diet containing 6 c/da...

  15. Packed multi-channels for parallel chromatographic separations in microchips.

    PubMed

    Nagy, Andrea; Gaspar, Attila

    2013-08-23

    Here we report on a simple method to fabricate microfluidic chip incorporating multi-channel systems packed by conventional chromatographic particles without the use of frits. The retaining effectivities of different bottlenecks created in the channels were studied. For the parallel multi-channel chromatographic separations several channel patterns were designed. The obtained multipackings were applied for parallel separations of dyes. The implementation of several chromatographic separation units in microscopic size makes possible faster and high throughput separations.

  16. Meal triacylglycerol profile modulates postprandial absorption of carotenoids in humans.

    PubMed

    Goltz, Shellen R; Campbell, Wayne W; Chitchumroonchokchai, Chureeporn; Failla, Mark L; Ferruzzi, Mario G

    2012-06-01

    Dietary lipids are considered to be primary potentiators of carotenoid absorption, yet the amount and source required to optimize bioavailability has not been systematically evaluated. The objective of this study was to examine the impact of both amount and source of triacylglycerols on postprandial absorption of carotenoids from vegetable salads. Healthy subjects (n = 29) were randomized using a Latin square design (3 × 3) and consumed three identical salads with 3, 8, or 20 g of canola oil, soybean oil, or butter. Blood was collected from 0-10 h and triacylglycerol-rich fractions (TRLs) were isolated by ultracentrifugation. Carotenoid contents of TRL fractions were analyzed by HPLC-DAD. Considering all lipid sources, 20 g of lipid promoted higher absorption compared to 3 and 8 g for all carotenoid species (p < 0.05), except for α-carotene (p = 0.07). The source of lipid had less impact on the absorption of carotenoids than amount of lipid. Pooling results from all lipid amounts, monounsaturated fatty acid rich canola oil trended toward enhancing absorption of lutein and α-carotene compared to saturated fatty acid rich butter (p = 0.06 and p = 0.08, respectively). While both amount and source of co-consumed lipid affect carotenoid bioavailability from vegetables, amount appears to exert a stronger effect. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Seeking carotenoid pigments in amber-preserved fossil feathers

    NASA Astrophysics Data System (ADS)

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-06-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  18. Bioavailability of natural carotenoids in human skin compared to blood.

    PubMed

    Meinke, Martina C; Darvin, Maxim E; Vollert, Henning; Lademann, Jürgen

    2010-10-01

    Skin functions and structure are significantly influenced by nutrients. Antioxidants protect the supportive layer of the skin against any damaging irradiation effects and the action of free radicals. A lack of suitable methods means that the pharmacokinetic properties of systemically applied carotenoids transferred into the skin remain poorly understood. In this study, a natural kale extract or placebo oil were given orally to 22 healthy volunteers for 4 weeks. Carotenoid bioaccessibility was evaluated using non-invasive resonance Raman spectroscopy on the palm and forehead skin. For the analysis of the blood serum, the standard HPLC method was used. The blood and skin levels of the carotenoids increased significantly during the study but compared to the blood serum values, increases in skin were delayed and depended on the dermal area as well as on the carotenoid. Lycopene, measured as being low in the extract, increases more in the skin compared to the blood indicating that the natural mixture of the extract stabilizes the antioxidative network in the skin. After supplementation had ended, the carotenoids decreased much faster in the blood than in the skin. The delayed decrease in the skin may indicate a peripheral buffer function of the skin for carotenoids.

  19. Raman detection of carotenoid pigments in the human retina

    NASA Astrophysics Data System (ADS)

    Gellermann, Werner; Ermakov, Igor V.; McClane, Robert W.; Bernstein, Paul S.

    2000-04-01

    We have used resonance Raman scattering as a novel, non- invasive, in-vivo optical technique to measure the concentration of carotenoid pigment in the human retina. Using argon laser excitation we are able to measure two strong carotenoid resonance Raman signals at 1159 and 1525 wave numbers, respectively. The required laser power levels are within the limits given by safety standards for ocular exposure. Of the approximately ten carotenoid pigment found in normal human serum, the species lutein and zeaxanthin are concentrated in high amounts in the cells of the human macula, which is an approximately 5 mm diameter area of the retina in which the visual acuity is highest. These carotenoids give the macula a characteristic yellow coloration, and it is speculated that these molecules function as filter to attenuate photochemical damage and/or image degradation under bright UV/blue light exposures. In addition, they are thought to act as free-radical scavenging antioxidants. Studies have shown that there may be a link between macular degenerative diseases, the leading cause of blindness in the elderly in the US, and the presence or absence of the carotenoids. We describe an instrument capable of measuring the macular carotenoids in human subjects in a non-invasive, rapid and quantitative way.

  20. Seeking carotenoid pigments in amber-preserved fossil feathers.

    PubMed

    Thomas, Daniel B; Nascimbene, Paul C; Dove, Carla J; Grimaldi, David A; James, Helen F

    2014-06-09

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  1. Seeking carotenoid pigments in amber-preserved fossil feathers

    PubMed Central

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-01-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy. PMID:24909554

  2. Carotenoid binding to proteins: Modeling pigment transport to lipid membranes.

    PubMed

    Reszczynska, Emilia; Welc, Renata; Grudzinski, Wojciech; Trebacz, Kazimierz; Gruszecki, Wieslaw I

    2015-10-15

    Carotenoid pigments play numerous important physiological functions in human organism. Very special is a role of lutein and zeaxanthin in the retina of an eye and in particular in its central part, the macula lutea. In the retina, carotenoids can be directly present in the lipid phase of the membranes or remain bound to the protein-pigment complexes. In this work we address a problem of binding of carotenoids to proteins and possible role of such structures in pigment transport to lipid membranes. Interaction of three carotenoids, beta-carotene, lutein and zeaxanthin with two proteins: bovine serum albumin and glutathione S-transferase (GST) was investigated with application of molecular spectroscopy techniques: UV-Vis absorption, circular dichroism and Fourier transform infrared spectroscopy (FTIR). Interaction of pigment-protein complexes with model lipid bilayers formed with egg yolk phosphatidylcholine was investigated with application of FTIR, Raman imaging of liposomes and electrophysiological technique, in the planar lipid bilayer models. The results show that in all the cases of protein and pigment studied, carotenoids bind to protein and that the complexes formed can interact with membranes. This means that protein-carotenoid complexes are capable of playing physiological role in pigment transport to biomembranes.

  3. Role of carotenoids in the phototropic response of corn seedings

    SciTech Connect

    Vierstra, R.D.; Poff, K.L.

    1981-10-01

    The herbicide 4 chloro-5-(methylamino)-2-..cap alpha..,..cap alpha..,..cap alpha..,-trifluoro-m-tolyl)-3(2H)- pyridazinone (SAN 9789), which blocks the synthesis in higher plants of colored carotenoids but not of flavins, was used to examine the involvement of carotenoids in corn seeding phototropism. It was concluded that ''bulk'' carotenoids are not the photoreceptor pigment based on the results that increasing concentrations of SAN 9789 (up to 100 micromolar) did not alter the phototropic sensitivity to 380 nanometers light (using geotropism as a control) and did not increase the threshold intensities of fluence response curves for both 380 and 450 nanometers light even though carotenoid content was reduced to 1 to 2% of normal. SAN 9789 treatment, however, did reduce seedling sensitivity toward 450 nanometers light indicating that carotenoids are involved in phototropism. Carotenoids, which are located mainly in the primary leaves, may act in phototropism as an internal screen, enhancing the light intensity gradient across the seedling and thus contributing to the ability of the seedling to perceive light direction. These results, indicate that the action spectra for phototropic responses can be significantly affected by the absorbance of screening pigments in vivo thus altering its shape from the in vitro absorption spectrum of the photoreceptor pigment.

  4. Cancer chemoprevention by natural carotenoids as an efficient strategy.

    PubMed

    Bolhassani, Azam

    2015-01-01

    The use of specific compounds to suppress the growth of tumors or reverse carcinogenesis is defined as chemoprevention. Natural products have been known as one of the most important resources of anticancer agents. Among them, carotenoids are lipophilic molecules accumulating in lipophilic compartments including lipoproteins and/or membranes. Various carotenoids were used as major phytonutrients to inhibit the development of tumors in vitro and in vivo. They have shown different functions such as scavenging free radicals, inhibition of angiogenesis, prevention of cell propagation, and apoptosis induction in lung, colon, breast and prostate. Regarding these roles, most carotenoids possess anti-oxidant properties. However, their therapeutic use is problematic due to the lack of solubility of carotenoids in water. Hence, recent studies have been focused on uncommon carotenoids soluble in water because of their glycosylated form, such as crocin(s) extracted from saffron. These structures with their cytotoxicity effects on human cancer cells are suggested as the most suitable compounds for cancer treatment. Herein, we summarize different functions of carotenoids for suppressing tumor growth.

  5. Production of carotenoids by microalgae: achievements and challenges.

    PubMed

    Varela, João C; Pereira, Hugo; Vila, Marta; León, Rosa

    2015-09-01

    Carotenoids are a wide group of lipophylic isoprenoids synthesized by all photosynthetic organisms and also by some non-photosynthetic bacteria and fungi. Animals, which cannot synthesize carotenoids de novo, must include them in their diet to fulfil essential provitamin, antioxidant, or colouring requirements. Carotenoids are indispensable in light harvesting and energy transfer during photosynthesis and in the protection of the photosynthetic apparatus against photooxidative damage. In this review, we outline the factors inducing carotenoid accumulation in microalgae, the knowledge acquired on the metabolic pathways responsible for their biosynthesis, and the recent achievements in the genetic engineering of this pathway. Despite the considerable progress achieved in understanding and engineering algal carotenogenesis, many aspects remain to be elucidated. The increasing number of sequenced microalgal genomes and the data generated by high-throughput technologies will enable a better understanding of carotenoid biosynthesis in microalgae. Moreover, the growing number of industrial microalgal species genetically modified will allow the production of novel strains with enhanced carotenoid contents.

  6. Heterosis for carotenoid concentration and profile in maize hybrids.

    PubMed

    Burt, Andrew J; Grainger, Christopher M; Shelp, Barry J; Lee, Elizabeth A

    2011-12-01

    Production of high-lutein maize grain is of particular interest as a value-added feed source to produce high-lutein eggs. In this paper, it is demonstrated that heterosis for total carotenoid concentration and for the ratio of lutein to zeaxanthin (L:Z ratio), or profile type, exists infrequently in yellow dent crosses. However, yellow dent inbred maize lines A619 and CG102, both possessing high-lutein profiles, produce F1 seed with a classic overdominant expression of lutein levels (i.e., 49 µg/g dry weight (DW) above the high-parent value). Reciprocal crosses of A619 and CG102 with one another and with two high-zeaxanthin (i.e., low lutein), high-carotenoid lines both suggest that the A619 and CG102 high-lutein phenotypes are achieved by different and complementary genotypes. The contribution of CG102 to the heterotic response was examined using a QTL-based approach that involved phenotyping the mapping population in a testcross to A619. Significant QTL were found at loci known to be involved in the carotenoid pathway but also at loci proximate to, but separate from, known carotenoid pathway steps. Exploiting an overdominant heterotic response for lutein and total carotenoids should be given strong consideration as a viable method of producing high-carotenoid hybrid maize lines.

  7. Carotenoids microencapsulation by spray drying method and supercritical micronization.

    PubMed

    Janiszewska-Turak, Emilia

    2017-09-01

    Carotenoids are used as natural food colourants in the food industry. As unstable natural pigments they need protection. This protection can involve the microencapsulation process. There are numerous techniques that can be used for carotenoid protection, but two of them -spray drying and supercritical micronization - are currently the most commonly used. The objective of this paper is to describe these two techniques for carotenoid microencapsulation. In this review information from articles from the last five years was taken into consideration. Pigments described in the review are all carotenoids. Short summary of carotenoids sources was presented. For the spray drying technique, a review of carrier material and process conditions was made. Moreover, a short description of some of the most suitable processes involving supercritical fluids for carotenoids (astaxanthin, β-carotene, lutein and lycopene) encapsulation was given. These include the Supercritical Antisolvent process (SAS), Particles from Gas-Saturated Solutions (PGSS), Supercritical Fluid Extraction From an Emulsion (SFEE) and Solution Enhanced Dispersion by Supercritical fluids (SEDS). In most cases the studies, independently of the described method, were conducted on the laboratory scale. In some a scale-up was also tested. In the review a critical assessment of the used methods was made. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effect of genotype and environment on citrus juice carotenoid content.

    PubMed

    Dhuique-Mayer, Claudie; Fanciullino, Anne-Laure; Dubois, Cecile; Ollitrault, Patrick

    2009-10-14

    A selection of orange and mandarin varieties belonging to the same Citrus accession and cultivated in Mediterranean (Corsica), subtropical (New Caledonia), and tropical areas (principally Tahiti) were studied to assess the effect of genotype and environmental conditions on citrus juice carotenoid content. Juices from three sweet orange cultivars, that is, Pera, Sanguinelli, and Valencia ( Citrus sinensis (L.) Osbeck), and two mandarin species ( Citrus deliciosa Ten and Citrus clementina Hort. ex Tan), were analyzed by HPLC using a C(30) column. Annual carotenoid content variations in Corsican fruits were evaluated. They were found to be very limited compared to variations due to varietal influences. The statistical analysis (PCA, dissimilarity tree) results based on the different carotenoid compounds showed that citrus juice from Corsica had a higher carotenoid content than citrus juices from tropical origins. The tropical citrus juices were clearly differentiated from citrus juices from Corsica, and close correlations were obtained between beta-cryptoxanthin and phytoene (r = 0.931) and beta-carotene and phytoene (r = 0.918). More broadly, Mediterranean conditions amplified interspecific differentiation, especially by increasing the beta-cryptoxanthin and cis-violaxanthin content in oranges and beta-carotene and phytoene-phytofluene content in mandarins. Thus, at a quantitative level, environmental conditions also had a major role in determining the levels of carotenoids of nutritional interest, such as the main provitamin A carotenoids in citrus juice (beta-cryptoxanthin and beta-carotene).

  9. Triplet excited state spectra and dynamics of carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect

    Niedzwiedzki, Dariusz; Kobayashi, Masayuki; Blankenship, R. E.

    2011-01-13

    Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll-a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll-a Q{sub x} band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.

  10. Generation of structurally novel short carotenoids and study of their biological activity.

    PubMed

    Kim, Se H; Kim, Moon S; Lee, Bun Y; Lee, Pyung C

    2016-02-23

    Recent research interest in phytochemicals has consistently driven the efforts in the metabolic engineering field toward microbial production of various carotenoids. In spite of systematic studies, the possibility of using C30 carotenoids as biologically functional compounds has not been explored thus far. Here, we generated 13 novel structures of C30 carotenoids and one C35 carotenoid, including acyclic, monocyclic, and bicyclic structures, through directed evolution and combinatorial biosynthesis, in Escherichia coli. Measurement of radical scavenging activity of various C30 carotenoid structures revealed that acyclic C30 carotenoids showed higher radical scavenging activity than did DL-α-tocopherol. We could assume high potential biological activity of the novel structures of C30 carotenoids as well, based on the neuronal differentiation activity observed for the monocyclic C30 carotenoid 4,4'-diapotorulene on rat bone marrow mesenchymal stem cells. Our results demonstrate that a series of structurally novel carotenoids possessing biologically beneficial properties can be synthesized in E. coli.

  11. Evidence for decreased interaction and improved carotenoid bioavailability by sequential delivery of a supplement.

    PubMed

    Salter-Venzon, Dawna; Kazlova, Valentina; Izzy Ford, Samantha; Intra, Janjira; Klosner, Allison E; Gellenbeck, Kevin W

    2017-05-01

    Despite the notable health benefits of carotenoids for human health, the majority of human diets worldwide are repeatedly shown to be inadequate in intake of carotenoid-rich fruits and vegetables, according to current health recommendations. To address this deficit, strategies designed to increase dietary intakes and subsequent plasma levels of carotenoids are warranted. When mixed carotenoids are delivered into the intestinal tract simultaneously, competition occurs for micelle formation and absorption, affecting carotenoid bioavailability. Previously, we tested the in vitro viability of a carotenoid mix designed to deliver individual carotenoids sequentially spaced from one another over the 6 hr transit time of the human upper gastrointestinal system. We hypothesized that temporally and spatially separating the individual carotenoids would reduce competition for micelle formation, improve uptake, and maximize efficacy. Here, we test this hypothesis in a double-blind, repeated-measure, cross-over human study with 12 subjects by comparing the change of plasma carotenoid levels for 8 hr after oral doses of a sequentially spaced carotenoid mix, to a matched mix without sequential spacing. We find the carotenoid change from baseline, measured as area under the curve, is increased following consumption of the sequentially spaced mix compared to concomitant carotenoids delivery. These results demonstrate reduced interaction and regulation between the sequentially spaced carotenoids, suggesting improved bioavailability from a novel sequentially spaced carotenoid mix.

  12. Vitamin C, provitamin A carotenoids, and other carotenoids in high-pressurized orange juice during refrigerated storage.

    PubMed

    Sánchez-Moreno, Concepción; Plaza, Lucía; De Ancos, Begoña; Cano, M Pilar

    2003-01-29

    Vitamin C, provitamin A carotenoids, and other carotenoids were measured in freshly squeezed juices from oranges (Citrus sinensis L. var. Valencia late) that were subjected to high-pressure (HP) treatment. Also, the stability of these compounds was studied during refrigerated storage at 4 degrees C. HP treatment is an alternative to heat preservation methods for foods; therefore, it is essential to assess the impact of HP on bioactive compounds. Several processes that combine HP treatment with heat treatment for various time periods were assayed: T0, fresh juice (without treatment); T1, 100 MPa/60 degrees C/5 min; T2, 350 MPa/30 degrees C/2.5 min; T3, 400 MPa/40 degrees C/1 min. Fresh and treated samples were kept refrigerated (4 degrees C) over 10 days. After application of HP and during the refrigeration period, the qualitative and quantitative determination of vitamin C, provitamin A carotenoids (beta- and alpha-carotene; beta- and alpha-cryptoxanthin), and the xanthophylls zeaxanthin and lutein was achieved by high-performance liquid chromatography. T1 and T3 juices showed a decrease in ascorbic acid and total vitamin C just after HP treatment (D0) compared with T0 juices. On the contrary, T2 juices, just after HP treatment (D0), had the same levels of both compounds compared to untreated juices. T1, T2, and T3 treatments led to an increase in the extraction of carotenoids and provitamin A carotenoids. Total carotenoid content after the 10-day refrigerated storage period resulted in no significant quantitative changes in T1 juices, whereas in T2 and T3 juices small losses were found at the end of the storage period (20.56 and 9.16%, respectively). These losses could be influenced by the depleted protection of vitamin C toward carotenoid oxidation during the same period. A similar trend was found in provitamin A carotenoids for the different treated juices.

  13. The Mycobacterium tuberculosis ORF Rv0654 encodes a carotenoid oxygenase mediating central and excentric cleavage of conventional and aromatic carotenoids.

    PubMed

    Scherzinger, Daniel; Scheffer, Erdmann; Bär, Cornelia; Ernst, Hansgeorg; Al-Babili, Salim

    2010-11-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, is assumed to lack carotenoids, which are widespread pigments fulfilling important functions as radical scavengers and as a source of apocarotenoids. In mammals, the synthesis of apocarotenoids, including retinoic acid, is initiated by the β-carotene cleavage oxygenases I and II catalyzing either a central or an excentric cleavage of β-carotene, respectively. The M. tuberculosis ORF Rv0654 codes for a putative carotenoid oxygenase conserved in other mycobacteria. In the present study, we investigated the corresponding enzyme, here named M. tuberculosis carotenoid cleavage oxygenase (MtCCO). Using heterologously expressed and purified protein, we show that MtCCO converts several carotenoids and apocarotenoids in vitro. Moreover, the identification of the products suggests that, in contrast to other carotenoid oxygenases, MtCCO cleaves the central C15-C15' and an excentric double bond at the C13-C14 position, leading to retinal (C(20)), β-apo-14'-carotenal (C(22)) and β-apo-13-carotenone (C(18)) from β-carotene, as well as the corresponding hydroxylated products from zeaxanthin and lutein. Moreover, the enzyme cleaves also 3,3'-dihydroxy-isorenieratene representing aromatic carotenoids synthesized by other mycobacteria. Quantification of the products from different substrates indicates that the preference for each of the cleavage positions is determined by the hydroxylation and the nature of the ionone ring. The data obtained in the present study reveal MtCCO to be a novel carotenoid oxygenase and indicate that M. tuberculosis may utilize carotenoids from host cells and interfere with their retinoid metabolism.

  14. Alpha and omega of carotenoid cleavage.

    PubMed

    Lakshman, M R

    2004-01-01

    molecular oxygen and is activated by ferrous ions. It is highly specific for 15:15' ethylenic bond of carotenoids although it has fairly broad specificity towards a number of carotenoids with at least one intact beta-ionone ring. The dioxygenase was recently cloned from Drosophila melanogaster and from the chicken intestine. The recombinant protein was found to form retinal as the sole cleavage product of beta-carotene. No apo-carotenoids were formed. Therefore, it is unequivocally proven that the major, if not the sole, pathway of beta-carotene cleavage to vitamin A is by oxidative cleavage of the central ethylenic bond of beta-carotene to yield two molecules of retinal. Most recently, human dioxygenase has also been cloned. Thus, the wisdom, vision and epoch-making mission of Jim Olson in the science of beta-carotene metabolism have been accomplished. I have no doubt that the impact of his original discovery of the dioxygenase and its importance in vitamin A nutriture should be forthcoming in the near future.

  15. Carotenoids, carotenoid esters, and anthocyanins of yellow-, orange-, and red-peeled cashew apples (Anacardium occidentale L.).

    PubMed

    Schweiggert, Ralf M; Vargas, Ester; Conrad, Jürgen; Hempel, Judith; Gras, Claudia C; Ziegler, Jochen U; Mayer, Angelika; Jiménez, Víctor; Esquivel, Patricia; Carle, Reinhold

    2016-06-01

    Pigment profiles of yellow-, orange-, and red-peeled cashew (Anacardium occidentale L.) apples were investigated. Among 15 identified carotenoids and carotenoid esters, β-carotene, and β-cryptoxanthin palmitate were the most abundant in peels and pulp of all samples. Total carotenoid concentrations in the pulp of yellow- and red-peeled cashew apples were low (0.69-0.73 mg/100g FW) compared to that of orange-peeled samples (2.2mg/100g FW). The color difference between the equally carotenoid-rich yellow and red colored samples indicated the presence of a further non-carotenoid pigment type in red peels. Among four detected anthocyanins, the major anthocyanin was unambiguously identified as 7-O-methylcyanidin 3-O-β-D-galactopyranoside by NMR spectroscopy. Red and yellow peel color was chiefly determined by the presence and absence of anthocyanins, respectively, while the orange appearance of the peel was mainly caused by increased carotenoid concentrations. Thus, orange-peeled fruits represent a rich source of provitamin A (ca. 124 μg retinol-activity-equivalents/100g pulp, FW).

  16. Diversity, physiology, and evolution of avian plumage carotenoids and the role of carotenoid-protein interactions in plumage color appearance.

    PubMed

    LaFountain, Amy M; Prum, Richard O; Frank, Harry A

    2015-04-15

    The diversity of vibrant plumage colors in birds has evolved as a direct result of social and environmental pressures. To fully understand these underlying pressures it is necessary to elucidate the mechanisms for the creation of novel plumage colors which include the metabolic transformations of dietary carotenoids and spectral tuning of the molecules within the feather protein environment. Recent advances in this field have greatly expanded the number and breadth of avian species for which plumage pigmentation has been characterized, making it possible to reconstruct the phylogenetic history of carotenoid usage in plumage. Resonance Raman and classical Raman spectroscopic techniques have been employed with great effect in the study of carotenoids in situ. The application of these methods have two benefits: to identify carotenoids in feathers that are unavailable for destructive sampling; and to study the spectral tuning resulting from the interaction between the carotenoids and the proteins to which they are bound. This review presents a summary of recent advances in the understanding of the molecular factors controlling the coloration of avian carotenoid plumage obtained through the application of both bioanalytical and spectroscopic methodologies.

  17. Evolution of carotenoid pigmentation in caciques and meadowlarks (Icteridae): repeated gains of red plumage coloration by carotenoid C4-oxygenation.

    PubMed

    Friedman, Nicholas R; McGraw, Kevin J; Omland, Kevin E

    2014-03-01

    Many animals use carotenoid pigments to produce yellow, orange, and red coloration. In birds, at least 10 carotenoid compounds have been documented in red feathers; most of these are produced through metabolic modification of dietary precursor compounds. However, it is poorly understood how lineages have evolved the biochemical mechanisms for producing red coloration. We used high-performance liquid chromatography to identify the carotenoid compounds present in feathers from 15 species across two clades of blackbirds (the meadowlarks and allies, and the caciques and oropendolas; Icteridae), and mapped their presence or absence on a phylogeny. We found that the red plumage found in meadowlarks includes different carotenoid compounds than the red plumage found in caciques, indicating that these gains of red color are convergent. In contrast, we found that red coloration in two closely related lineages of caciques evolved twice by what appear to be similar biochemical mechanisms. The C4-oxygenation of dietary carotenoids was responsible for each observed transition from yellow to red plumage coloration, and has been commonly reported by other researchers. This suggests that the C4-oxygenation pathway may be a readily evolvable means to gain red coloration using carotenoids.

  18. High carotenoid production by a halotolerant bacterium, Kocuria sp. strain QWT-12 and anticancer activity of its carotenoid

    PubMed Central

    Sarvari, Sajad; Moakedi, Faezeh

    2017-01-01

    Halophilic prokaryotes are extremophile microorganisms that grow optimally in media containing salts and almost appeared pigmented. Many of them contain high concentrations of carotenoids. Amongst 15 strains of halophilic prokaryotes isolated from industrial tannery wastewater in Qom, a Gram-stain-positive coccoid, aerobic, non-endospore-forming, halotolerant bacterium designated as strain QWT-12 showed high capacity in the production of carotenoids in a wide range of culture medium factors. 16S rRNA gene analysis showed that this strain belongs to the genus Kocuria. Carotenoids from this strain were extracted by methanol. MTT assay for extracted carotenoid was carried out against seven cancer cell lines belonging to breast, lung and prostate cancer with negative control of fibroblast cell line through six concentration levels to find out IC50. Based on statistical analysis of data from MTT assay, IC50 of 1, 4 and 8 mg/ml for MCF-7, (A549 and MDA-MB-468) and MDA-MB-231 respectively. Additionally, qualitative carotenoid determination was carried out using spectrophotometric method in 300-600 nm and thin layer chromatography, respectively. According to the obtained results from mass spectrophotometry, absorption spectrum of strain QWT-12 is similar to the absorption spectrum of the carotenoid neurosporene. PMID:28827999

  19. Analysis of carotenoid accumulation and expression of carotenoid biosynthesis genes in different organs of Chinese cabbage (Brassica rapa subsp. pekinensis)

    PubMed Central

    Tuan, Pham Anh; Kim, Jae Kwang; Lee, Jeongyeo; Park, Woo Tae; Kwon, Do Yeon; Kim, Yeon Bok; Kim, Haeng Hoon; Kim, Hye Ran; Park, Sang Un

    2012-01-01

    The relationship between carotenoid accumulation and expression of carotenoid biosynthesis genes was investigated in the flowers, stems, young leaves, old leaves, and roots of Chinese cabbage (Brassica rapa subsp. pekinensis). Quantitative real-time PCR analysis showed that the mRNA levels of BrPSY, BrPDS, BrZDS, BrLCYB, BrLCYE, BrCHXB, and BrZEP leading to the production of carotenoids were highest in the flowers or the leaves and lowest in the roots of Chinese cabbage. In contrast, the mRNA expression of BrNCED, a gene involved in abscisic acid (ABA) biosynthesis, was highest in the roots. High-performance liquid chromatography revealed that carotenoids, namely, lutein and β-carotene, were distributed predominantly in the flowers and leaves, with very little in the underground organ, the roots. Specifically, old leaves contained 120.3 μg/g lutein and 103.93 μg/g β-carotene, which is the most potent dietary precursor of vitamin A. Moreover, we found a relatively large amount of cis isomers of β-carotene, namely, 9-cis β-carotene and 13-cis β-carotene, in Chinese cabbage. These results provide insight into carotenoid biosynthetic mechanisms in Chinese cabbage and may be helpful in the metabolic engineering of carotenoid biosynthesis in plants. PMID:27540344

  20. Validation model for Raman based skin carotenoid detection.

    PubMed

    Ermakov, Igor V; Gellermann, Werner

    2010-12-01

    Raman spectroscopy holds promise as a rapid objective non-invasive optical method for the detection of carotenoid compounds in human tissue in vivo. Carotenoids are of interest due to their functions as antioxidants and/or optical absorbers of phototoxic light at deep blue and near UV wavelengths. In the macular region of the human retina, carotenoids may prevent or delay the onset of age-related tissue degeneration. In human skin, they may help prevent premature skin aging, and are possibly involved in the prevention of certain skin cancers. Furthermore, since carotenoids exist in high concentrations in a wide variety of fruits and vegetables, and are routinely taken up by the human body through the diet, skin carotenoid levels may serve as an objective biomarker for fruit and vegetable intake. Before the Raman method can be accepted as a widespread optical alternative for carotenoid measurements, direct validation studies are needed to compare it with the gold standard of high performance liquid chromatography. This is because the tissue Raman response is in general accompanied by a host of other optical processes which have to be taken into account. In skin, the most prominent is strongly diffusive, non-Raman scattering, leading to relatively shallow light penetration of the blue/green excitation light required for resonant Raman detection of carotenoids. Also, sizable light attenuation exists due to the combined absorption from collagen, porphyrin, hemoglobin, and melanin chromophores, and additional fluorescence is generated by collagen and porphyrins. In this study, we investigate for the first time the direct correlation of in vivo skin tissue carotenoid Raman measurements with subsequent chromatography derived carotenoid concentrations. As tissue site we use heel skin, in which the stratum corneum layer thickness exceeds the light penetration depth, which is free of optically confounding chromophores, which can be easily optically accessed for in vivo RRS

  1. Nonlinear Optical Properties of Carotenoid and Chlorophyll Harmonophores

    NASA Astrophysics Data System (ADS)

    Tokarz, Danielle Barbara

    Information regarding the structure and function of living tissues and cells is instrumental to the advancement of cell biology and biophysics. Nonlinear optical microscopy can provide such information, but only certain biological structures generate nonlinear optical signals. Therefore, structural specificity can be achieved by introducing labels for nonlinear optical microscopy. Few studies exist in the literature about labels that facilitate harmonic generation, coined "harmonophores". This thesis consists of the first major investigation of harmonophores for third harmonic generation (THG) microscopy. Carotenoids and chlorophylls were investigated as potential harmonophores. Their nonlinear optical properties were studied by the THG ratio technique. In addition, a tunable refractometer was built in order to determine their second hyperpolarizability (gamma). At 830 nm excitation wavelength, carotenoids and chlorophylls were found to have large negative gamma values however, at 1028 nm, the sign of gamma reversed for carotenoids and remained negative for chlorophylls. Consequently, at 1028 nm wavelength, THG signal is canceled with mixtures of carotenoids and chlorophylls. Furthermore, when such molecules are covalently bonded as dyads or interact within photosynthetic pigment-protein complexes, it is found that additive effects with the gamma values still play a role, however, the overall gamma value is also influenced by the intra-pigment and inter-pigment interaction. The nonlinear optical properties of aggregates containing chlorophylls and carotenoids were the target of subsequent investigations. Carotenoid aggregates were imaged with polarization-dependent second harmonic generation and THG microscopy. Both techniques revealed crystallographic information pertaining to H and J aggregates and beta-carotene crystalline aggregates found in orange carrot. In order to demonstrate THG enhancement due to labeling, cultured cells were labeled with carotenoid

  2. Dietary supplementation with a natural carotenoid mixture decreases oxidative stress.

    PubMed

    Kiokias, S; Gordon, M H

    2003-09-01

    To determine whether dietary supplementation with a natural carotenoid mixture counteracts the enhancement of oxidative stress induced by consumption of fish oil. A randomised double-blind crossover dietary intervention. Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Whiteknights PO Box 226, Reading RG6 6AP, UK. A total of 32 free-living healthy nonsmoking volunteers were recruited by posters and e-mails in The University of Reading. One volunteer withdrew during the study. The volunteers consumed a daily supplement comprising capsules containing fish oil (4 x 1 g) or fish oil (4 x 1 g) containing a natural carotenoid mixture (4 x 7.6 mg) for 3 weeks in a randomised crossover design separated by a 12 week washout phase. The carotenoid mixture provided a daily intake of beta-carotene (6.0 mg), alpha-carotene (1.4 mg), lycopene (4.5 mg), bixin (11.7 mg), lutein (4.4 mg) and paprika carotenoids (2.2 mg). Blood and urine samples were collected on days 0 and 21 of each dietary period. The carotenoid mixture reduced the fall in ex vivo oxidative stability of low-density lipoprotein (LDL) induced by the fish oil (P=0.045) and it reduced the extent of DNA damage assessed by the concentration of 8-hydroxy-2'-deoxyguanosine in urine (P=0.005). There was no effect on the oxidative stability of plasma ex vivo assessed by the oxygen radical absorbance capacity test. beta-Carotene, alpha-carotene, lycopene and lutein were increased in the plasma of subjects consuming the carotenoid mixture. Plasma triglyceride levels were reduced significantly more than the reduction for the fish oil control (P=0.035), but total cholesterol, HDL and LDL levels were not significantly changed by the consumption of the carotenoid mixture. Consumption of the natural carotenoid mixture lowered the increase in oxidative stress induced by the fish oil as assessed by ex vivo oxidative stability of LDL and DNA degradation product in urine. The carotenoid

  3. Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root

    USDA-ARS?s Scientific Manuscript database

    Several groups have reported on massive accumulation of total carotenoids in cassava storage root (CSR). Naturally occurring color variation associated with carotenoid accumulation was observed in cassava (Manihot esculenta Crantz) storage root of landraces from Amazon. Here carotenoid profiles from...

  4. Synthetic Biology and Metabolic Engineering for Marine Carotenoids: New Opportunities and Future Prospects

    PubMed Central

    Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

    2014-01-01

    Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations. PMID:25233369

  5. Synthetic biology and metabolic engineering for marine carotenoids: new opportunities and future prospects.

    PubMed

    Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

    2014-09-17

    Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations.

  6. Carotenoids: actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans.

    PubMed

    Maiani, Giuseppe; Castón, María Jesús Periago; Catasta, Giovina; Toti, Elisabetta; Cambrodón, Isabel Goñi; Bysted, Anette; Granado-Lorencio, Fernando; Olmedilla-Alonso, Begoña; Knuthsen, Pia; Valoti, Massimo; Böhm, Volker; Mayer-Miebach, Esther; Behsnilian, Diana; Schlemmer, Ulrich

    2009-09-01

    Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: beta-carotene, beta-cryptoxanthin, alpha-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.

  7. Slow deactivation channels in UV-photoexcited adenine DNA.

    PubMed

    Chen, Xuebo; Fang, Weihai; Wang, Haobin

    2014-03-07

    The molecular mechanism for removing the excess energy in DNA bases is responsible for the high photostability of DNA and is thus the subject of intense theoretical/computational investigation. To understand why the excited state decay of the stacked bases is significantly longer than that of the monomers, we carried out electronic structure calculations on an adenine monomer and an aqueous (dA)5 oligonucleotide employing the CASPT2//CASSCF and CASPT2//CASSCF/AMBER levels of theory. The newly-found bright excited state pair Sstack1((1)ππ*) and Sstack2((1)ππ*) of d(A)5, originated from base stacking, is of intra-base charge transfer nature and occurs in different stacked bases with charge transfer along opposite directions. Two slow deactivation channels of d(A)5 were proposed as a result of the sizable barriers along the relaxation paths starting from the FC point of the Sstack1((1)ππ*) state. The SN1P((1)nπ*) state of d(A)5 serves as an intermediate state in one relaxation channel, to which a nonadiabatic decay from the Sstack1((1)ππ*) state occurs in an energy degeneracy region. A relatively high barrier in this state is found and attributed to the steric hindrance of the DNA environment due to the large NH2 group twisting, which gives a weak and red-shifted fluorescence. Another direct relaxation channel, induced by the C2-H2 bond twisting motion, is found to go through a conical intersection between the Sstack1((1)ππ*) and the ground state. The barrier found here enables fluorescence from the Sstack1((1)ππ*) state and may explain the bright state emission observed in the fluorescence upconversion measurements. The inter-molecular SCT((1)ππ*) state may be involved in the slow relaxation process of the photoexcited adenine oligomers through efficient internal conversion to the intra-base Sstack1((1)ππ*) state.

  8. Nuclear fuel reprocessing deactivation plan for the Idaho Chemical Processing Plant, Revision 1

    SciTech Connect

    Patterson, M.W.

    1994-10-01

    The decision was announced on April 28, 1992 to cease all United States Department of Energy (DOE) reprocessing of nuclear fuels. This decision leads to the deactivation of all fuels dissolution, solvent extraction, krypton gas recovery operations, and product denitration at the Idaho Chemical Processing Plant (ICPP). The reprocessing facilities will be converted to a safe and stable shutdown condition awaiting future alternate uses or decontamination and decommissioning (D&D). This ICPP Deactivation Plan includes the scope of work, schedule, costs, and associated staffing levels necessary to achieve a safe and orderly deactivation of reprocessing activities and the Waste Calcining Facility (WCF). Deactivation activities primarily involve shutdown of operating systems and buildings, fissile and hazardous material removal, and related activities. A minimum required level of continued surveillance and maintenance is planned for each facility/process system to ensure necessary environmental, health, and safety margins are maintained and to support ongoing operations for ICPP facilities that are not being deactivated. Management of the ICPP was transferred from Westinghouse Idaho Nuclear Company, Inc. (WINCO) to Lockheed Idaho Technologies Company (LITCO) on October 1, 1994 as part of the INEL consolidated contract. This revision of the deactivation plan (formerly the Nuclear Fuel Reprocessing Phaseout Plan for the ICPP) is being published during the consolidation of the INEL site-wide contract and the information presented here is current as of October 31, 1994. LITCO has adopted the existing plans for the deactivation of ICPP reprocessing facilities and the plans developed under WINCO are still being actively pursued, although the change in management may result in changes which have not yet been identified. Accordingly, the contents of this plan are subject to revision.

  9. Patients' perception of implantable cardioverter defibrillator deactivation at the end of life.

    PubMed

    Hill, Loreena; McIlfatrick, Sonja; Taylor, Brian; Dixon, Lana; Harbinson, Mark; Fitzsimons, Donna

    2015-04-01

    Individualised care at the end of life requires professional understanding of the patient's perception of implantable cardioverter defibrillator deactivation. The aim was to evaluate the evidence on patients' perception of implantable cardioverter defibrillator deactivation at end of life. Systematic narrative review of empirical studies was published during 2008-2014. Data were collected from six databases, citations from relevant articles and expert recommendations. In all, 18 studies included with collective population of n = 5810. Concept mapping highlighted three themes: (1) Diverse preferences regarding discussion and deactivation. Deactivation was rarely discussed pre-implantation, with some studies demonstrating patients' reluctance to discuss implantable cardioverter defibrillator deactivation at any stage. Two studies found the majority of patients valued such discussions. Diversity was reflected in patients' willingness to deactivate, ranging from 12% (n = 9) in Irish cohort to 79% (n = 195) in Dutch study. (2) Ethical and legal considerations were predominant in Canadian and American literature as patients wanted to contribute but felt the decision should be a doctor's responsibility. Advance directives were uncommon in Europe, and where they existed the implantable cardioverter defibrillator was not mentioned. (3) 'Living in the now' was evident as despite deteriorating symptoms many patients maintained a positive outlook and anticipated surviving more than 10 years. Several studies asserted living longer was more important than quality of life. Patients regard the implantable cardioverter defibrillator as a complex and solely beneficial device, with little insight regarding its potential impact on a peaceful death. This review confirms the need for professionals to discuss with patients and families implantable cardioverter defibrillator functionality and deactivation at appropriate opportunities. © The Author(s) 2014.

  10. Differential Deactivation during Mentalizing and Classification of Autism Based on Default Mode Network Connectivity

    PubMed Central

    Murdaugh, Donna L.; Shinkareva, Svetlana V.; Deshpande, Hrishikesh R.; Wang, Jing; Pennick, Mark R.; Kana, Rajesh K.

    2012-01-01

    The default mode network (DMN) is a collection of brain areas found to be consistently deactivated during task performance. Previous neuroimaging studies of resting state have revealed reduced task-related deactivation of this network in autism. We investigated the DMN in 13 high-functioning adults with autism spectrum disorders (ASD) and 14 typically developing control participants during three fMRI studies (two language tasks and a Theory-of-Mind (ToM) task). Each study had separate blocks of fixation/resting baseline. The data from the task blocks and fixation blocks were collated to examine deactivation and functional connectivity. Deficits in the deactivation of the DMN in individuals with ASD were specific only to the ToM task, with no group differences in deactivation during the language tasks or a combined language and self-other discrimination task. During rest blocks following the ToM task, the ASD group showed less deactivation than the control group in a number of DMN regions, including medial prefrontal cortex (MPFC), anterior cingulate cortex, and posterior cingulate gyrus/precuneus. In addition, we found weaker functional connectivity of the MPFC in individuals with ASD compared to controls. Furthermore, we were able to reliably classify participants into ASD or typically developing control groups based on both the whole-brain and seed-based connectivity patterns with accuracy up to 96.3%. These findings indicate that deactivation and connectivity of the DMN were altered in individuals with ASD. In addition, these findings suggest that the deficits in DMN connectivity could be a neural signature that can be used for classifying an individual as belonging to the ASD group. PMID:23185536

  11. Development of multichannel MEG system at IGCAR

    NASA Astrophysics Data System (ADS)

    Mariyappa, N.; Parasakthi, C.; Gireesan, K.; Sengottuvel, S.; Patel, Rajesh; Janawadkar, M. P.; Radhakrishnan, T. S.; Sundar, C. S.

    2013-02-01

    We describe some of the challenging aspects in the indigenous development of the whole head multichannel magnetoencephalography (MEG) system at IGCAR, Kalpakkam. These are: i) fabrication and testing of a helmet shaped sensor array holder of a polymeric material experimentally tested to be compatible with liquid helium temperatures, ii) the design and fabrication of the PCB adapter modules, keeping in mind the inter-track cross talk considerations between the electrical leads used to provide connections from SQUID at liquid helium temperature (4.2K) to the electronics at room temperature (300K) and iii) use of high resistance manganin wires for the 86 channels (86×8 leads) essential to reduce the total heat leak which, however, inevitably causes an attenuation of the SQUID output signal due to voltage drop in the leads. We have presently populated 22 of the 86 channels, which include 6 reference channels to reject the common mode noise. The whole head MEG system to cover all the lobes of the brain will be progressively assembled when other three PCB adapter modules, presently under fabrication, become available. The MEG system will be used for a variety of basic and clinical studies including localization of epileptic foci during pre-surgical mapping in collaboration with neurologists.

  12. Time estimation with multichannel digital silicon photomultipliers.

    PubMed

    Venialgo, Esteban; Mandai, Shingo; Gong, Tim; Schaart, Dennis R; Charbon, Edoardo

    2015-03-21

    Accuracy in timemark estimation is crucial for time-of-flight positron emission tomography, in order to ensure high quality images after reconstruction. Since the introduction of multichannel digital silicon photomultipliers, it is possible to acquire several photoelectron timestamps for each individual gamma event. We study several timemark estimators based on multiple photoelectron timestamps by means of a comprehensive statistical model. In addition, we calculate the MSE of the estimators in comparison to the Cramér-Rao lower bound as a function of the system design parameters. We investigate the effect of skipping some of the photoelectron timestamps, which is a direct consequence of the limited number of time-to-digital converters and we propose a technique to compensate for this effect. In addition, we carry out an extensive analysis to evaluate the influence of dark counts on the detector timing performance. Moreover, we investigate the improvement of the timing performance that can be obtained with dark count filtering and we propose an appropriate filtering method based on measuring the time difference between sorted timestamps. Finally, we perform a full Monte Carlo simulation to compare different timemark estimators by exploring several system design parameters. It is demonstrated that a simple weighted-average estimator can achieve a comparable performance as the more complex maximum likelihood estimator.

  13. Capacitance Probe Resonator for Multichannel Electrometer

    NASA Technical Reports Server (NTRS)

    Blaes, Brent R.; Schaefer, Rembrandt T> ; Glaser, Robert J.

    2012-01-01

    A multichannel electrometer voltmeter has been developed that employs a mechanical resonator with voltage-sensing capacitance-probe electrodes that enable high-impedance, high-voltage, radiation-hardened measurement of an Internal Electrostatic Discharge Monitor (IESDM) sensor. The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. The resonator solution relies on a non-contact, voltage-sensing, sinusoidal-varying capacitor to achieve input impedances as high as 10 petaohms as determined by the resonator materials, geometries, cleanliness, and construction. The resonator is designed with one dominant mechanical degree of freedom, so it resonates as a simple harmonic oscillator and because of the linearity of the variable sense capacitor to displacement, generates a pure sinusoidal current signal for a fixed input voltage under measurement. This enables the use of an idealized phase-lock sensing scheme for optimal signal detection in the presence of noise.

  14. Multichannel hybrid system for neuromagnetic measurements.

    PubMed

    Foglietti, V; Del Gratta, C; Pasquarelli, A; Pizzella, V; Torrioli, G; Romani, G L; Gallagher, W J; Ketchen, M B; Kleinsasser, A W; Sandstrom, R L

    1991-01-01

    This paper describes progress toward the development of a 28-multichannel system for neuromagnetic measurements. A novel 'hybrid' design consisting of 16 first-order axial gradiometers and 12 first-order planar gradiometers was chosen, which optimises the use of the available cylindrical volume of the dewar tail. This configuration maintains the symmetry of the detected pattern with respect to rotation of a biomagnetic source located under the centre of the array and features a localisation power considerably better than an array of all first-order planar gradiometers. The detecting array permits simultaneous magnetic measurements over a circular scalp region of 16 cm diameter. The magnetic sensors used are Nb/PbAuIn DC SQUIDs fabricated at the IBM. The devices incorporate resonant damping resistors shunting the inductance, resulting in smooth flux-voltage characteristics and, consequently, very low noise figures in a flux-locked loop configuration. A simple and low cost electronic system has been designed and fabricated for the DC SQUID sensors.

  15. Scalable multichannel MRI data acquisition system.

    PubMed

    Bodurka, Jerzy; Ledden, Patrick J; van Gelderen, Peter; Chu, Renxin; de Zwart, Jacco A; Morris, Doug; Duyn, Jeff H

    2004-01-01

    A scalable multichannel digital MRI receiver system was designed to achieve high bandwidth echo-planar imaging (EPI) acquisitions for applications such as BOLD-fMRI. The modular system design allows for easy extension to an arbitrary number of channels. A 16-channel receiver was developed and integrated with a General Electric (GE) Signa 3T VH/3 clinical scanner. Receiver performance was evaluated on phantoms and human volunteers using a custom-built 16-element receive-only brain surface coil array. At an output bandwidth of 1 MHz, a 100% acquisition duty cycle was achieved. Overall system noise figure and dynamic range were better than 0.85 dB and 84 dB, respectively. During repetitive EPI scanning on phantoms, the relative temporal standard deviation of the image intensity time-course was below 0.2%. As compared to the product birdcage head coil, 16-channel reception with the custom array yielded a nearly 6-fold SNR gain in the cerebral cortex and a 1.8-fold SNR gain in the center of the brain. The excellent system stability combined with the increased sensitivity and SENSE capabilities of 16-channel coils are expected to significantly benefit and enhance fMRI applications. Published 2003 Wiley-Liss, Inc.

  16. Fault-tolerant multichannel demultiplexer subsystems

    NASA Technical Reports Server (NTRS)

    Redinbo, Robert

    1991-01-01

    Fault tolerance in future processing and switching communication satellites is addressed by showing new methods for detecting hardware failures in the first major subsystem, the multichannel demultiplexer. An efficient method for demultiplexing frequency slotted channels uses multirate filter banks which contain fast Fourier transform processing. All numerical processing is performed at a lower rate commensurate with the small bandwidth of each bandbase channel. The integrity of the demultiplexing operations is protected by using real number convolutional codes to compute comparable parity values which detect errors at the data sample level. High rate, systematic convolutional codes produce parity values at a much reduced rate, and protection is achieved by generating parity values in two ways and comparing them. Parity values corresponding to each output channel are generated in parallel by a subsystem, operating even slower and in parallel with the demultiplexer that is virtually identical to the original structure. These parity calculations may be time shared with the same processing resources because they are so similar.

  17. AOSC multichannel electronic variable optical attenuator

    NASA Astrophysics Data System (ADS)

    Vonsovici, Adrian P.; Day, Ian E.; House, Andrew A.; Asghari, Mehdi

    2001-05-01

    Optical networks are becoming a reality as the physical layer of high-performance telecommunication networks. The deployment of wavelength-division multiplexing (WDM) technology allows the extended exploitation of installed fibers now facing an increasing traffic capacity demand. Performances of such systems can be degraded by wide variations of the optical channel power following propagation in the network. Therefore a tilt control of optical amplifiers in WDM networks and dynamic channel power regulation and equalisation in cross-connected nodes is necessary. An important tool for the system designer is the variable optical attenuator (VOA). We present the design and the realization of newly developed VOAs using the ASOC technology. This technology refers to the fabrication of integrated optics components in silicon-on-insulator (SOI) material. The device is based on the light absorption by the free-carriers that are injected in the core of a rib waveguide from a p-i-n diode. The devices incorporate horizontally and vertically tapered waveguides for minimum fiber coupling loss. The p-i-n diode for carrier injection into the active region of the rib waveguide was optimised in order to enhance the attenuation. One major advantage of the ASOC technology is the possibility of monolithic integration of many integrated optics devices on one chip. In the light of this the paper illustrates the result of characterisation of multichannel VOAs.

  18. Multichannel hierarchical image classification using multivariate copulas

    NASA Astrophysics Data System (ADS)

    Voisin, Aurélie; Krylov, Vladimir A.; Moser, Gabriele; Serpico, Sebastiano B.; Zerubia, Josiane

    2012-03-01

    This paper focuses on the classification of multichannel images. The proposed supervised Bayesian classification method applied to histological (medical) optical images and to remote sensing (optical and synthetic aperture radar) imagery consists of two steps. The first step introduces the joint statistical modeling of the coregistered input images. For each class and each input channel, the class-conditional marginal probability density functions are estimated by finite mixtures of well-chosen parametric families. For optical imagery, the normal distribution is a well-known model. For radar imagery, we have selected generalized gamma, log-normal, Nakagami and Weibull distributions. Next, the multivariate d-dimensional Clayton copula, where d can be interpreted as the number of input channels, is applied to estimate multivariate joint class-conditional statistics. As a second step, we plug the estimated joint probability density functions into a hierarchical Markovian model based on a quadtree structure. Multiscale features are extracted by discrete wavelet transforms, or by using input multiresolution data. To obtain the classification map, we integrate an exact estimator of the marginal posterior mode.

  19. Novel revolving multichannel electromechanical optical switch

    NASA Astrophysics Data System (ADS)

    Ge, Wenping; Yin, Zongmin; Liu, Jingjing; Zhou, Zhengli

    2001-10-01

    In this paper, we described a kind of structures and the principle about a multi-channel optical switch. we designed a novel revolving single mode optical switch, which based on electronically controlled fiber collimators directing the light to desired output fibers, and the movement of fiber collimator is implemented by the rotation of stepping micro-electromotor. The main parts of the optical switch are two cylinders being carrier of fiber collimators, one of which can revolve driven by stepping micro-electromotor which is controlled by micro-computer. With flexibility of structure,it is easy to design the series of 1xN optical switches. Furthermore, by using two or more revolving axes, we can design reasonably the position of the optical collimators, and get no-blocking 2x2 or 4x4 optical switch matrix. We fabricated a 1×8 single1 mode optical switch, and the experiment results indicate that the technical performance of the optical switch can satisfy requires for changing light channel.

  20. Sparse reconstruction of correlated multichannel activity.

    PubMed

    Peelman, Sem; Van der Herten, Joachim; De Vos, Maarten; Lee, Wen-Shin; Van Huffel, Sabine; Cuyt, Annie

    2013-01-01

    Parametric methods for modeling sinusoidal signals with line spectra have been studied for decades. In general, these methods start by representing each sinusoidal component by means of two complex exponential functions, thereby doubling the number of unknown parameters. Recently, a Hankel-plus-Toeplitz matrix pencil method was proposed which directly models sinusoidal signals with discrete spectral content. Compared to its counterpart, which uses a Hankel matrix pencil, it halves the required number of time-domain samples and reduces the size of the involved linear systems. The aim of this paper is twofold. Firstly, to show that this Hankel-plus-Toeplitz matrix pencil also applies to continuous spectra. Secondly, to explore its use in the reconstruction of real-life signals. Promising preliminary results in the reconstruction of correlated multichannel electroencephalographic (EEG) activity are presented. A principal component analysis preprocessing step is carried out to exploit the redundancy in the channel domain. Then the reduced signal representation is successfully reconstructed from fewer samples using the Hankel-plus-Toeplitz matrix pencil. The obtained results encourage the future development of this matrix pencil method along the lines of well-established spectral analysis methods.