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Sample records for astrophytum myriostigma lemaire

  1. Morfometría de semillas en la cactácea amenazada de extinción Astrophytum myriostigma Lemaire

    Directory of Open Access Journals (Sweden)

    Jaime Sánchez-Salas

    2015-07-01

    Full Text Available Se presenta un estudio morfométrico y microestructural en semillas de una población de la cactácea amenazadaAstrophytum myriostigmaLem., removida en su tota- lidad en el sitio por saqueo. Se incluyen resultados que separan tamaños de semillas y embriones (grandes y pequeños así como promedios para ambos. Se realizó una descripción de características en la semilla obtenidas mediante estereoscopía. Se incluye una descripción detallada de la forma y color, así como microestructural del funículo, capa funicular y otras estructuras que le acompañan.

  2. A tale of two cacti-the complex relationship between peyote (Lophophora williamsii) and endangered star cactus (Astrophytum asterias)

    Science.gov (United States)

    M. Terry; D. Price; J. Poole

    2007-01-01

    Astrophytum asterias, commonly called star cactus, is a federally listed endangered cactus endemic to the Tamaulipan thornscrub ecoregion of extreme southern Texas, USA, and Tamaulipas and Nuevo Leon, Mexico. Only three metapopulations totaling less than 4000 plants are presently known in Texas. Star cactus, known locally as “star peyote”, is highly...

  3. Lemaire, Marianne. – Les sillons de la souffrance

    OpenAIRE

    Launay, Robert

    2012-01-01

    Les sillons de la souffrance is a richly documented ethnography that focuses on the range of activities and meanings associated with the word faliwi among the Tyebara, a Senufo sub-group in the region of Korhogo in Côte-d’Ivoire. As Lemaire points out, faliwi can only very approximately be translated as “work”. Some activities which we would consider “work”, such as food preparation, are not considered faliwi, which can however include ritual activities which do not fall into the category of ...

  4. Hypoglycemic effect of Opuntia streptacantha Lemaire in NIDDM.

    Science.gov (United States)

    Frati-Munari, A C; Gordillo, B E; Altamirano, P; Ariza, C R

    1988-01-01

    To assess the hypoglycemic effect of the nopal Opuntia streptacantha Lemaire (O. streptacantha Lem.), three groups of patients with non-insulin-dependent diabetes mellitus (NIDDM) were studied. Group one (16 patients) ingested 500 g of broiled nopal stems. Group 2 (10 patients) received only 400 ml of water as a control test. Three tests were performed on group 3 (6 patients): one with nopal, a second with water, and a third with ingestion of 500 g broiled squash. Serum glucose and insulin levels were measured at 0, 60, 120, and 180 min. After the intake of O. streptacantha Lem., serum glucose and serum insulin levels decreased significantly in groups 1 and 3, whereas no similar changes were noticed in group 2. The mean reduction of glucose reached 17.6 +/- 2.2% of basal values at 180 min in group 1 and 16.2 +/- 1.8% in group 3; the reduction of serum insulin at 180 min reached 50.2 +/- 8.0% in group 1 and 40.3 +/- 12.4% in group 3. This study shows that the stems of O. streptacantha Lem. cause a hypoglycemic effect in patients with NIDDM. The mechanism of this effect is unknown, but an increased insulin sensitivity is suggested.

  5. The potential of the extracts of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae), the vector for Leishmania major Yakimoff and Schokhor.

    Science.gov (United States)

    Ireri, Laban N; Kongoro, Jedida; Ngure, Peter; Mutai, Charles; Langat, Bernard; Tonui, Willy; Kimutai, Albert; Mucheru, Obadiah

    2010-09-01

    Harmful effects of synthetic chemical insecticides including vector resistance, environmental pollution and health hazards have necessitated the current significance in the search for plant-based insecticide products that are environmentally safe and effective to leishmaniases control. The insecticidal activity of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) extracts were investigated against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae). The extracts were prepared from dried aerial parts soaked in methanol and ethyl acetate twice until the filtrates became clear, filtered and dried out by rotary evaporation at 30-35 degrees C. The solid extracts obtained were later prepared into 2.5, 5 and 10 mg/ml. Two millilitres of the solutions were blotted on filter papers, which were dried overnight and placed into jars where adult sandflies were aspirated. Males and females were assayed separately. The extracts had significant mortality (pTagetes minuta had significantly higher mortality rates than those of Tarchonanthus camphoratus and the different concentrations used showed significantly different mortality rates and 10 mg/ml was the most effective concentration. Cent percent mortality was obtained at 96 h of exposure to 5 and 10 mg/ml concentrations except for Tarchonanthus camphoratus which had a mortality of only 46.7% in 10 mg/ml bioassay. These extracts were found to be insecticidal to adult sandflies.

  6. Anatomical and morphological features of seedlings of some Cactoideae Eaton (Cactaceae Juss. species

    Directory of Open Access Journals (Sweden)

    Halyna Kalashnyk

    2016-12-01

    Full Text Available Three-month-old seedlings of 11 species of the subfamily Cactoideae (Melocactus bahiensis, Melocactus curvispinus, Echinopsis eyriesii, E. mirablis, E. peruviana, Oreocereus celsianus, Rebutia flavistyla, Rebutia minuscula, Astrophytum myriostigma, Mamillaria columbiana, and M. prolifera have been studied. These plants exhibit a uniseriate epidermis, covered by a thin cuticle. Except for E. peruviana and A. myriostigma, no hypodermis could be detected. The shoots of all studied specimens consist mainly of cortex parenchyma with large thin-walled cells. The pith parenchyma is composed of much smaller cells. Due to the fact that the cortex parenchyma comprises the largest portion of the cross-sectional area, it can be concluded that it is the main water-storing tissue. The extent of vascular tissue development varies. Collateral vascular bundles are present in the stele. The studied seedlings contain various ergastic substances, in particular inclusions of calcium oxalate (all studied species, starch (Mammillaria prolifera, E. mirabilis, and the genus Melocactus, inulin-like inclusions, and occasionally lipid drops (some Echinopsis species. Thus, it was found that all studied plants have a highly specialized anatomical and morphological structure. At the same time, the epidermis and hypodermis are poorly developed. Accordingly, the adaptation to arid conditions of the examined seedlings involves an increased growth of the water-storing tissue and the production of ergastic substances.

  7. Hydrolysis of Agave fourcroydes Lemaire (henequen) leaf juice and fermentation with Kluyveromyces marxianus for ethanol production.

    Science.gov (United States)

    Villegas-Silva, Pablo A; Toledano-Thompson, Tanit; Canto-Canché, Blondy B; Larqué-Saavedra, Alfonso; Barahona-Pérez, Luis F

    2014-02-14

    Carbon sources for biofuel production are wide-ranging and their availability depends on the climate and soil conditions of the land where the production chain is located. Henequen (Agave fourcroydes Lem.) is cultivated in Yucatán, Mexico to produce natural fibers from the leaves, and a juice containing fructans is produced during this process. Fructans can be hydrolyzed to fructose and glucose and metabolized into ethanol by appropriate yeasts. In Mexico, different Agave species provide the carbon source for (distilled and non-distilled) alcoholic beverage production using the stem of the plant, whilst the leaves are discarded. In this work, we investigated the effect of thermal acid and enzymatic hydrolysis of the juice on the amount of reducing sugars released. Growth curves were generated with the yeasts Saccharomyces cerevisiae and Kluyveromyces marxianus and fermentations were then carried out with Kluyveromyces marxianus to determine alcohol yields. With thermal acid hydrolysis, the greatest increase in reducing sugars (82.6%) was obtained using 5% H2SO4 at 100°C with a 30 min reaction time. Statistically similar results can be obtained using the same acid concentration at a lower temperature and with a shorter reaction time (60°C, 15 min), or by using 1% H2SO4 at 100°C with a 30 min reaction time. In the case of enzymatic hydrolysis, the use of 5.75, 11.47 and 22.82 U of enzyme did not produce significant differences in the increase in reducing sugars. Although both hydrolysis processes obtained similar results, the difference was observed after fermentation. Ethanol yields were 50.3 ± 4 and 80.04 ± 5.29% of the theoretical yield respectively. Final reducing sugars concentrations obtained with both thermal acid and enzymatic hydrolysis were similar. Saccharomyces cerevisiae, a good ethanol producer, did not grow in the hydrolysates. Only Kluyveromyces marxianus was able to grow in them, giving a higher ethanol yield with the enzymatic hydrolysate. The leaves account for a non-negligible weight of the total agave plant biomass, so this work complements the knowledge already developed on agave fermentations by making it possible to produce ethanol from almost the entire plant (stem and leaves).

  8. [Hypoglycemic action of different doses of nopal (Opuntia streptacantha Lemaire) in patients with type II diabetes mellitus].

    Science.gov (United States)

    Frati-Munari, A C; Del Valle-Martínez, L M; Ariza-Andraca, C R; Islas-Andrade, S; Chávez-Negrete, A

    1989-01-01

    To assess the relationship between the doses of O. streptacantha Lem. and its acute hypoglycemic action in diabetics, eight patients with type II diabetes mellitus were studied. Four test were performed to each patient with the intake of: (a) 400 ml of water, (b) 100 g (c) 300 g and (d) 500 g of broiled stems of O. streptacantha Lem. Serum glucose was measured at 0, 60, 120 and 180 minutes. Maximal decrease of serum glucose was noticed at 180 minutes, with a mean of 2.3, 10, 30.1 and 46.7 mg/dl less than basal value with 0, 100, 300 and 500 g respectively (P = NS, less than 0.05, less than 0.001 and less than 0.001 respectively). A significant direct correlation (r = 0.690, P less than 0.001) was noticed between the doses and the hypoglycemic effect.

  9. Morphometrical and ecological analysis of nematodes of the family Capillariidae (Neveu-Lemaire, 1936) in wild ducks (Anatinae) from the north-western Poland.

    Science.gov (United States)

    Stapf, Agata N; Kavetska, Katarzyna M; Ptak, Piotr P; Rzad, Izabella

    2013-01-01

    West Pomerania is located on the migratory route of many species of birds. Among them are many representatives of wild duck species (subfamily Anatinae), which are often the primary hosts of many helminths due to the fact of living in two different environments: terrestrial and aquatic. However, until the end of the 90s, research conducted in Poland on the helminth fauna of wild birds, including nematodes of the family Capillariidae, did not include the north-western region of the country. These first studies performed in 1999, aimed at the identification of the nematodes of wild ducks from the West Pomerania region, revealed the presence of three species belonging to family Capillariidae, i.e. Capillaria anatis (Schrank, 1790) Travassos, 1915, Eucoleus contortus (Creplin, 1839) Gagarin, 1951 and Pseudocapillaria mergi (Madsen, 1945). The purpose of the current study was to perform a comprehensive ecological analysis of C. anatis, E. contortus and P. mergi, including such factors as intensity, prevalence, relative density, index of fidelity and dominance index. The experimental material comprised 811 nematodes isolated from the gastrointestinal tracts of 953 ducks. These 9 species of ducks belong to three different tribes of the Anatinae subfamily: Anatini (Anas clypeata, A. crecca, A. platyrhynchos), Aythyini (Aythya fuligula, A. marila) and Mergini (Bucephala clangula, Clangula hyemalis, Mergus merganseri, Somateria mollissima) and diverse in terms of their biology and ecology. The morphometric and morphological analyses fail to identify any significant differences in the body structures of nematodes of the species C. anatis, E. contortus and P. mergi of the West Pomerania region in comparison with those found in other regions of Poland and Europe. The ecological analysis of the Capillariidae family in the West Pomerania region revealed that ducks of the tribe Anatini (mainly A. platyrhynchos) are the most common hosts of E. contortus species, C. anatis is most commonly found in ducks of the tribe Aythyini, and P. mergi is relatively frequent in ducks of the tribe Mergini (mainly in M. merganser).

  10. Descripción de la hembra de Copaxa ignescens (Lepidoptera: Saturniidae, con anotaciones sobre sus primeros estadios inmaduros

    Directory of Open Access Journals (Sweden)

    Amarillo S. Angela R.

    1997-06-01

    Full Text Available The female of Copaxa ignescens Lemaire, 1978 (Saturniidae is described and notes on the first three larval instars are presented. The caterpillars were reared on Avocado (Persea americana Miller.Se describe la hembra de Copaxa ignescens Lemaire, 1978 (Saturniidae y se hacen anotaciones sobre los tres primeros estadios larvales. Las orugas se criaron con Aguacate (Persaa americana Miller.

  11. Letters & Arms Literary Language, Power and Nation in Renaissance Italy and France 1300-1600

    DEFF Research Database (Denmark)

    Toftgaard, Anders

    2005-01-01

    Sprog, litteratur, filologi, national identitet, Joachim Du Bellay, Jean Lemaire de Belges, Henri Estienne, Sperone Speroni, Pietro Bembo, Dante Alighieri, Frans den første (af Frankrig), Anthony D. Smith, Liah Greenfeld...

  12. Maailma kuulsaim krokodill sai 75 aastaseks / Anu Merila

    Index Scriptorium Estoniae

    Merila, Anu

    2008-01-01

    Lacoste'i sportlikke rõivaid ja aksessuaare tootvast kaubamärgist, asutaja Rene Lacoste. Firma loominguliseks direktoriks on prantsuse moekunstnik Christophe Lemaire. Küsimustele vastab Philippe Lacoste

  13. Letters & Arms Literary Language, Power and Nation in Renaissance Italy and France 1300-1600

    DEFF Research Database (Denmark)

    Toftgaard, Anders

    2005-01-01

    Sprog, litteratur, filologi, national identitet, Joachim Du Bellay, Jean Lemaire de Belges, Henri Estienne, Sperone Speroni, Pietro Bembo, Dante Alighieri, Frans den første (af Frankrig), Anthony D. Smith, Liah Greenfeld......Sprog, litteratur, filologi, national identitet, Joachim Du Bellay, Jean Lemaire de Belges, Henri Estienne, Sperone Speroni, Pietro Bembo, Dante Alighieri, Frans den første (af Frankrig), Anthony D. Smith, Liah Greenfeld...

  14. 370-IJBCS-Article-Prof Etienne Tedonkeng Pamo

    African Journals Online (AJOL)

    Dr Gatsing

    Tropicales, Roberge G, Toutain (eds). CIRAD ; 19 – 51. Lemaire G, Salette J, Laissus R. 1982. Analyse de la croissance d'une prairie naturelle normande au printemps II. La dynamique d'absorption de l'azote et son efficience. Fourrages, 92 : 51-65. Lhoste P, Dolle V, Rousseau J, Soltner D. 1993. Zootechnie des Régions ...

  15. Case report

    African Journals Online (AJOL)

    abp

    2 juil. 2015 ... Le Hello C, Mouthon L, Larroche C, Lemaire V, Piette AM, Piette. JC, Ponge T, Puechal X, Rossert J, Sarrot-Reynauld F, Sicard D,. Ziza JM, Kahn MF, Guillevin L. Vasculitides associated with malignancies: analysis of sixty patients. Arthritis Rheum. 2007;57(8):1473-80. PubMed | Google Scholar. 12. Hutson ...

  16. The Status of Three Species of Turacos in the Kakum Conservation ...

    African Journals Online (AJOL)

    komla

    large body sizes, they may be important seed dispersers in African tropical forest (Dowsett-Lemaire,. 1983, 1990; Brosset & Erard, 1986; ..... trails for watching turacos and other birds. Tourist turaco-watchers must be aware that ... guide tourist bird-watchers interested in the turaco species (Fig. 1). Among all the forest camps, ...

  17. The Rock Pratincole Glareola nuchalis in Tanzania: the first ...

    African Journals Online (AJOL)

    Nairobi. Delany, S., Scott, D., Dodman, T. & Stroud, D. (Eds.) 2009. An Atlas of Wader. Populations in Africa and Western Eurasia. Wetlands International. Wageningen, The. Netherlands. Dowsett-Lemaire, F. & Dowsett, R.J. 2006. The Birds of Malawi: An atlas and handbook. Tauraco Press and Aves a.s.b.l. Liège, Belgium.

  18. Biomechanical Comparison of Anterolateral Procedures Combined With Anterior Cruciate Ligament Reconstruction.

    Science.gov (United States)

    Inderhaug, Eivind; Stephen, Joanna M; Williams, Andy; Amis, Andrew A

    2017-02-01

    Anterolateral soft tissue structures of the knee have a role in controlling anterolateral rotational laxity, and they may be damaged at the time of anterior cruciate ligament (ACL) ruptures. To compare the kinematic effects of anterolateral operative procedures in combination with intra-articular ACL reconstruction for combined ACL plus anterolateral-injured knees. Controlled laboratory study. Twelve cadaveric knees were tested in a 6 degrees of freedom rig using an optical tracking system to record the kinematics through 0° to 90° of knee flexion with no load, anterior drawer, internal rotation, and combined loading. Testing was first performed in ACL-intact, ACL-deficient, and combined ACL plus anterolateral-injured (distal deep insertions of the iliotibial band and the anterolateral ligament [ALL] and capsule cut) states. Thereafter, ACL reconstruction was performed alone and in combination with the following: modified MacIntosh tenodesis, modified Lemaire tenodesis passed both superficial and deep to the lateral collateral ligament, and ALL reconstruction. Anterolateral grafts were fixed at 30° of knee flexion with both 20 and 40 N of tension. Statistical analysis used repeated-measures analyses of variance and paired t tests with Bonferroni adjustments. ACL reconstruction alone failed to restore native knee kinematics in combined ACL plus anterolateral-injured knees ( P tension, except for ALL reconstruction ( P = .002-.01), restored anterior translation. With 40 N of tension, the superficial Lemaire and MacIntosh procedures overconstrained the anterior laxity in deep flexion. Only the deep Lemaire and MacIntosh procedures-with 20 N of tension-restored rotational kinematics to the intact state ( P > .05 for all), while the ALL underconstrained and the superficial Lemaire overconstrained internal rotation. The same procedures with 40 N of tension led to similar findings. In a combined ACL plus anterolateral-injured knee, ACL reconstruction alone failed to

  19. The time course of strategy sequential difficulty effects: an ERP study in arithmetic.

    Science.gov (United States)

    Uittenhove, Kim; Poletti, Celine; Dufau, Stephane; Lemaire, Patrick

    2013-05-01

    Uittenhove and Lemaire (Exp Psychol 59(5):295-301, 2012) found that we are slower when executing a strategy following a difficult strategy than when executing the same strategy following an easier strategy (i.e., strategy sequential difficulty effects). Uittenhove and Lemaire suggested that difficult strategies temporarily reduce available executive capacities, interfering with the next strategy execution. In this study, we used ERP to determine the time course of these effects. In a computational estimation task, we found greater cerebral activities during strategy execution following a more difficult compared to an easier strategy. Interestingly, greater cerebral activities were most apparent immediately after the encoding of the problem and not during encoding or in later stages of processing. This suggests that strategy sequential difficulty effects interfere most with the retrieval of procedures in contrast to execution of these procedures. We discuss implications of these findings for further understanding of execution of cognitive strategies.

  20. IBMISPS (International Brain Mapping & Intraoperative Surgical Planning Symposium)

    Science.gov (United States)

    2005-12-01

    maladie de Parkinson sévère: Étude de la localisation des contacts effectifs. Neurochirurgie (in press). Lemaire et al. (2001). Deep brain...extensive intraoperative evaluation. Advances in paradigm design and data analysis in neuropsychological imaging can provide more detailed maps of this...orchestration of frontal activation road maps gained with modern neuropsychological imaging tools. Title: Bioluminescent Imaging in the GFAP-luc Transgenic

  1. Proceedings of Asilomar Conference on Fire and Blast Effects of Nuclear Weapons (17th), held at the Asilomar Conference Center, Pacific Grove, California, on May 30-June 3, 1983

    Science.gov (United States)

    1983-07-01

    BiO.Systams A Service Natural Resources A Energy Finance ; Inforsation System Environment and Accountin2 Reliability MArteting; Organization Analysis Military...34Some Civil Defense Problems in the Nation’s Capital Following Widespread Thermonuclear Attack", Opns. Res. (5), 319-350. 33. ]TeTeher, Grace J. "A...Regarding Fire and Consequential Loss", Skandinavian Actuarial Journal, 229-234, (1978). 59. Lemaire, J. "Exchange de Risques Entre Assureurs et

  2. Hypoglycemic effect of Opuntia cactus.

    Science.gov (United States)

    Ibañez-Camacho, R; Roman-Ramos, R

    1979-01-01

    Nopal (Opuntia sp.) has been traditionally used by the Mexican population for the treatment of diabetes mellitus. The purpose of this work is to describe effects produced by directly liquified nopal and extracts from this plant in healthy and pancreatectomized rabbits. Preliminary results allow us to conclude that Opuntia streptacantha, Lemaire, has hypoglycemic properties when orally administered, in animals with experimentally induced diabetes as well as in healthy ones with physiologic hyperglycemia.

  3. Clinical effects of an oral supplement rich in antioxidants on skin radiance in women

    OpenAIRE

    Dumoulin M; Gaudout D; Lemaire B

    2016-01-01

    Marion Dumoulin, David Gaudout, Benoit Lemaire Activ’Inside, Libourne, France Background: Environmental factors impact the skin aging resulting in decrease of skin radiance. Nutrition and particularly antioxidants could help to fight against skin degradation.Objective: The aim of this study was to evaluate the effects of an oral supplement rich in specific antioxidants, SkinAx2TM, on the improvement of the skin radiance in women.Methods: The open-label clinical stu...

  4. Book Review The Birds of Zambia: an Atlas and Handbook By ...

    African Journals Online (AJOL)

    Book Review The Birds of Zambia: an Atlas and Handbook By Robert J Dowsett, Dylan R Aspinwall and Françoise Dowsett-Lemaire (2008). Lizanne Roxburgh. Abstract. Turaco Press and Aves a.s.b.l., Rue Fusch 3, B-4000 Liège, Belgium 606 pages, softcover. ISBN 2-87225-005-0, price £30. Ostrich 2008, 79(2): 251 ...

  5. Identification of the Gene for Scleroderma in the Tsk/2 Mouse Strain: Implications for Human Scleroderma Pathogenesis and Subset Distinctions

    Science.gov (United States)

    2015-09-01

    described in 1986, when an offspring of a 101/H mouse exposed to the mutagenic agent ethylnitrosourea was noted to have tight skin in the interscapular...region (Peters and Ball, 1986). The mutagenized gene causing SSc-like signs in Tsk2/þ mice was reported to be located on chromosome 1 between 42.5 and...MJ (2000) The mutagenic action of N-ethyl-N- nitrosourea in the mouse. Mamm Genome 11:478–83 Pendergrass SA, Lemaire R, Francis IP et al. (2012

  6. Browse Author Index

    African Journals Online (AJOL)

    Items 51 - 100 of 208 ... A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All. D. Dowsett-Lemaire, F · Dranzoa, C. E. Ejotre, I · Ekesa, S · Ellison, M · Enawgaw, C · Ewnetu, M. F. Finch, B · Finch, BW · Fisher, D · Fisher, David · Freymann, B P. G. Garama, J · Gebremedhin, B · Gedeon, K · Giesen, W · Githiru, M · Glen, R

  7. Diterbium heptanickel: a crystal structure redetermination

    Directory of Open Access Journals (Sweden)

    Volodymyr Levytskyy

    2014-08-01

    Full Text Available The crystal structure of the title compound, Tb2Ni7, was redetermined from single-crystal X-ray diffraction data. In comparison with previous studies based on powder X-ray diffraction data [Lemaire et al. (1967. C. R. Acad. Sci. Ser. B, 265, 1280–1282; Lemaire & Paccard (1969. Bull. Soc. Fr. Mineral. Cristallogr. 92, 9–16; Buschow & van der Goot (1970. J. Less-Common Met. 22, 419–428], the present redetermination affords refined coordinates and anisotropic displacement parameters for all atoms. A partial occupation for one Tb atom results in the non-stoichiometric composition Tb1.962 (4Ni7. The title compound adopts the Ce2Ni7 structure type and can also be derived from the CaCu5 structure type as an intergrowth structure. The asymmetric unit contains two Tb sites (both site symmetries 3m. and five Ni sites (.m., mm2, 3m., 3m., -3m.. The two different coordination polyhedra of Tb are a Frank–Kasper polyhedron formed by four Tb and 12 Ni atoms and a pseudo Frank–Kasper polyhedron formed by two Tb and 18 Ni atoms. The four different coordination polyhedra of Ni are Frank–Kasper icosahedra formed by five Tb and seven Ni atoms, four Tb and eight Ni atoms, three Tb and nine Ni atoms, and six Tb and six Ni atoms, respectively.

  8. First-Order Twistor Lifts

    Directory of Open Access Journals (Sweden)

    Simões BrunoAscenso

    2010-01-01

    Full Text Available The use of twistor methods in the study of Jacobi fields has proved quite fruitful, leading to a series of results. L. Lemaire and J. C. Wood proved several properties of Jacobi fields along harmonic maps from the two-sphere to the complex projective plane and to the three- and four-dimensional spheres, by carefully relating the infinitesimal deformations of the harmonic maps to those of the holomorphic data describing them. In order to advance this programme, we prove a series of relations between infinitesimal properties of the map and those of its twistor lift. Namely, we prove that isotropy and harmonicity to first order of the map correspond to holomorphicity to first order of its lift into the twistor space, relatively to the standard almost complex structures and . This is done by obtaining first-order analogues of classical twistorial constructions.

  9. Strategy sequential difficulty effects vary with working-memory and response-stimulus-intervals: a study in arithmetic.

    Science.gov (United States)

    Uittenhove, Kim; Lemaire, Patrick

    2013-05-01

    Strategy sequential difficulty effects are the findings that when participants execute strategies, performance is worse after a difficult strategy than after an easy strategy (Uittenhove & Lemaire, 2012). Strategy sequential difficulty effects are hypothesized to result from decreased working-memory resources following difficult strategy execution. In the present study we found a correlation between individuals' working memory and strategy sequential difficulty effects in arithmetic, supporting a working-memory account of these effects. Furthermore, we varied response-stimulus intervals, and we found decreased strategy sequential difficulty effects with increasing response-stimulus intervals. Implications of these findings for further understanding of strategic variations in human cognition are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. First-Order Twistor Lifts

    Directory of Open Access Journals (Sweden)

    Bruno Ascenso Simões

    2010-01-01

    Full Text Available The use of twistor methods in the study of Jacobi fields has proved quite fruitful, leading to a series of results. L. Lemaire and J. C. Wood proved several properties of Jacobi fields along harmonic maps from the two-sphere to the complex projective plane and to the three- and four-dimensional spheres, by carefully relating the infinitesimal deformations of the harmonic maps to those of the holomorphic data describing them. In order to advance this programme, we prove a series of relations between infinitesimal properties of the map and those of its twistor lift. Namely, we prove that isotropy and harmonicity to first order of the map correspond to holomorphicity to first order of its lift into the twistor space, relatively to the standard almost complex structures J1 and J2. This is done by obtaining first-order analogues of classical twistorial constructions.

  11. Extra-Articular Lateral Tenodesis for Anterior Cruciate Ligament Deficient Knee: A Case Report

    Directory of Open Access Journals (Sweden)

    Diego García-Germán

    2013-01-01

    Full Text Available We present the case of an extra-articular lateral tenodesis for an anterior cruciate ligament (ACL deficient knee. A 46-year-old male patient sustained an ACL graft rupture after a motorcycle accident. He complained of rotational instability and giving-way episodes. His previous graft was fixed by an intra-articular femoral staple that was not possible to remove at the time of the ACL revision. A modified Lemaire procedure was then performed. He gained rotational stability and was able to resume his sporting activities. We believe that isolated extra-articular reconstructions may still have a role in selected indications including moderate-demand patients complaining of rotational instability after ACL graft failure.

  12. Mécanotransduction du remodelage osseux : rôle des fissures à la périphérie des ostéons

    Science.gov (United States)

    Lemaire, Thibault; Borocin, Fabien; Naili, Salah

    2008-04-01

    Cortical bone is a kind of hard tissue found at the edges of long bones. Its unit structural elements are the cylindrical osteons. During daily activities, they are subjected to an important mechanical load. Bone remodelling is suspected to be initiated by different stimuli including micro-cracks and interstitial fluid movement. Stimulation of the mechano-sensitive cells (osteocytes) resulting from micro-cracks presence on the external wall (cement surface) of the osteon is studied. To this end, poroelasticity is used to describe cortical tissue behaviour. Finally, osteocytes network excitation because of surface micro-cracks presence is explained thanks to a finite element study. To cite this article: T. Lemaire et al., C. R. Mecanique 336 (2008).

  13. Vers le partage du savoir-écrire la loi ? Analyse sémio-discursive du dispositif

    OpenAIRE

    Alexis, Lucie; Chevret-Castellani, Christine; Labelle, Sarah; Mouratidou, Eleni

    2017-01-01

    Entre le 26 septembre et le 18 octobre 2015, le gouvernement mettait à la disposition des citoyens une plateforme de contribution au texte législatif relatif au « projet de loi pour une République numérique » (www.republique-numerique.fr/, ci-après RN.fr), élaboré par le cabinet d’Axelle Lemaire, secrétaire d’État chargée du Numérique. Avant cela, le Conseil national du numérique (CNNum) avait mené, entre octobre 2014 et février 2015, un processus de concertation intitulé « Ambition numérique...

  14. Connecting World Heritage Nominations and Monitoring with the Support of the Silk Roads Cultural Heritage Resource Information System

    Science.gov (United States)

    Vileikis, O.; Dumont, B.; Serruys, E.; Van Balen, K.; Tigny, V.; De Maeyer, P.

    2013-07-01

    Serial transnational World Heritage nominations are challenging the way cultural heritage has been managed and evaluated in the past. Serial transnational World Heritage nominations are unique in that they consist of multiple sites listed as one property, distributed in different countries, involving a large diversity of stakeholders in the process. As a result, there is a need for precise baseline information for monitoring, reporting and decision making. This type of nomination requires different methodologies and tools to improve the monitoring cycle from the beginning of the nomination towards the periodic reporting. The case study of the Silk Roads Cultural Heritage Resource Information System (CHRIS) illustrates the use of a Geographical Content Management System (Geo-CMS) supporting the serial transnational World Heritage nomination and the monitoring of the Silk Roads in the five Central Asian countries. The Silk Roads CHRIS is an initiative supported by UNESCO World Heritage Centre (WHC) and the Belgian Federal Science Policy Office (BELSPO), and developed by a consortium headed by the Raymond Lemaire International Centre for Conservation (RLICC) at the KULeuven. The Silk Roads CHRIS has been successfully assisting in the preparation of the nomination dossiers of the Republics of Kazakhstan, Tajikistan and Uzbekistan and will be used as a tool for monitoring tool in the Central Asian countries.

  15. Detection of a plasmaspheric wind in the Earth's magnetosphere by the Cluster spacecraft

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    I. Dandouras

    2013-07-01

    Full Text Available Plumes, forming at the plasmapause and released outwards, constitute a well-established mode for plasmaspheric material release to the Earth's magnetosphere. They are associated to active periods and the related electric field change. In 1992, Lemaire and Shunk proposed the existence of an additional mode for plasmaspheric material release to the Earth's magnetosphere: a plasmaspheric wind, steadily transporting cold plasmaspheric plasma outwards across the geomagnetic field lines, even during prolonged periods of quiet geomagnetic conditions. This has been proposed on a theoretical basis. Direct detection of this wind has, however, eluded observation in the past. Analysis of ion measurements, acquired in the outer plasmasphere by the CIS experiment onboard the four Cluster spacecraft, provide now an experimental confirmation of the plasmaspheric wind. This wind has been systematically detected in the outer plasmasphere during quiet and moderately active conditions, and calculations show that it could provide a substantial contribution to the magnetospheric plasma populations outside the Earth's plasmasphere. Similar winds should also exist on other planets, or astrophysical objects, quickly rotating and having an atmosphere and a magnetic field.

  16. Conserved regions of the DMD 3' UTR regulate translation and mRNA abundance in cultured myotubes.

    Science.gov (United States)

    Larsen, C Aaron; Howard, Michael T

    2014-08-01

    Duchenne muscular dystrophy (DMD), a severe muscle-wasting disease, is caused by mutations in the DMD gene, which encodes for the protein dystrophin. Its regulation is of therapeutic interest as even small changes in expression of functional dystrophin can significantly impact the severity of DMD. While tissue-specific distribution and transcriptional regulation of several DMD mRNA isoforms has been well characterized, the post-transcriptional regulation of dystrophin synthesis is not well understood. Here, we utilize qRTPCR and a quantitative dual-luciferase reporter assay to examine the effects of isoform specific DMD 5' UTRs and the highly conserved DMD 3' UTR on mRNA abundance and translational control of gene expression in C2C12 cells. The 5' UTRs were shown to initiate translation with low efficiency in both myoblasts and myotubes. Whereas, two large highly conserved elements in the 3' UTR, which overlap the previously described Lemaire A and D regions, increase mRNA levels and enhance translation upon differentiation of myoblasts into myotubes. The results presented here implicate an important role for DMD UTRs in dystrophin expression and delineate the cis-acting elements required for the myotube-specific regulation of steady-state mRNA levels and translational enhancer activity found in the DMD 3' UTR. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Conserved regions of the DMD 3’ UTR regulate translation and mRNA abundance in cultured myotubes

    Science.gov (United States)

    Larsen, C. Aaron; Howard, Michael T.

    2014-01-01

    Duchenne muscular dystrophy (DMD), a severe muscle-wasting disease, is caused by mutations in the DMD gene, which encodes for the protein dystrophin. Its regulation is of therapeutic interest as even small changes in expression of functional dystrophin can significantly impact the severity of DMD. While tissue-specific distribution and transcriptional regulation of several DMD mRNA isoforms has been well characterized, the post-transcriptional regulation of dystrophin synthesis is not well understood. Here, we utilize qRTPCR and a quantitative dual-luciferase reporter assay to examine the effects of isoform specific DMD 5’ UTRs and the highly conserved DMD 3’ UTR on mRNA abundance and translational control of gene expression in C2C12 cells. The 5’ UTRs were shown to initiate translation with low efficiency in both myoblasts and myotubes. Whereas, two large highly conserved elements in the 3’ UTR, which overlap the previously described Lemaire A and D regions, increase mRNA levels and enhance translation upon differentiation of myoblasts into myotubes. The results presented here implicate an important role for DMD UTRs in dystrophin expression and delineate the cis-acting elements required for the myotube-specific regulation of steady-state mRNA levels and translational enhancer activity found in the DMD 3’ UTR. PMID:24928536

  18. Coleopterans associated with plants that form phytotelmata in subtropical and temperate Argentina, South America.

    Science.gov (United States)

    Campos, Raúl E; Fernández, Liliana A

    2011-01-01

    A list of the most common plants that form phytotelmata and their associated coleopterans (aquatic, semi-aquatic and terrestrial) from the northeastern subtropical and temperate area of Argentina, South America with biological and behavioral observations is presented in this study. Species of Poaceae (n = 3), Bromeliaceae (5), Apiaceae (6), Araceae (2), Urticaceae (1), Marantaceae (1), Arecaceae (1), Dipsacaceae (1) and Cyperaceae (1) were identified as phytotelmata. Aquatic species of Scirtidae (2), Dytiscidae (2), and Hydrophilidae (4), semi-aquatic Chelonariidae (2), and terrestrial species of Carabidae (3), Staphylinidae (5), Histeridae (1), Elateridae (1), Cantharidae (1), Cleridae (1), Tenebrionidae (1), Meloidae (1), Anthicidae (1), Chrysomelidae (3), Curculionidae (7) and Apionidae (1) were identified from six species of Eryngium L. (Apiales: Apiaceae), two species of Guadua Kunth (Poales: Poaceae), Aechmea distichantha Lemaire (Poales: Bromeliaceae), and from fallen leaves of Euterpe edulis Martius (Arecales: Arecaceae) from the temperate and subtropical area. The highest species richness was recorded in Eryngium phytotelmata. Fifteen species of beetles inhabit Eryngium cabrerae Pontiroli, 11 in E. horridum Malme, 7 in E. stenophyllum Urban, 4 in E. aff. serra Chamisso and Schlechtendal., 3 in E. elegans Chamisso and Schlechtendal, 2 in E. eburneum Decne and E. pandanifolium Chamisso and Schlechtendal. From bamboo, 6 species of coleopterans were collected from Guadua trinii (Nees) Nees ex Ruprecht and 4 from G. chacoensis (Rojas) Londoño and Peterson. Three species of aquatic coleopterans were recorded from A. distichantha and only one from E. edulis.

  19. Neural correlates of arithmetic calculation strategies.

    Science.gov (United States)

    Rosenberg-Lee, Miriam; Lovett, Marsha C; Anderson, John R

    2009-09-01

    Recent research into math cognition has identified areas of the brain that are involved in number processing (Dehaene, Piazza, Pinel, & Cohen, 2003) and complex problem solving (Anderson, 2007). Much of this research assumes that participants use a single strategy; yet, behavioral research finds that people use a variety of strategies (LeFevre et al., 1996; Siegler, 1987; Siegler & Lemaire, 1997). In the present study, we examined cortical activation as a function of two different calculation strategies for mentally solving multidigit multiplication problems. The school strategy, equivalent to long multiplication, involves working from right to left. The expert strategy, used by "lightning" mental calculators (Staszewski, 1988), proceeds from left to right. The two strategies require essentially the same calculations, but have different working memory demands (the school strategy incurs greater demands). The school strategy produced significantly greater early activity in areas involved in attentional aspects of number processing (posterior superior parietal lobule, PSPL) and mental representation (posterior parietal cortex, PPC), but not in a numerical magnitude area (horizontal intraparietal sulcus, HIPS) or a semantic memory retrieval area (lateral inferior prefrontal cortex, LIPFC). An ACT-R model of the task successfully predicted BOLD responses in PPC and LIPFC, as well as in PSPL and HIPS.

  20. Alien taxa of the tribe Senecioneae (Asteraceae in Italy: a nomenclatural synopsis

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    Iamonico Duilio

    2017-12-01

    Full Text Available A nomenclatural synopsis of the alien species belonging to the tribe Senecioneae currently recorded in Italy (8 species is presented. The occurrence at the regional level, as well as the level of naturalization and ecological notes for each taxon are provided. A diagnostic key of the non-native Italian species is also given. The names Cineraria petasitis (now Senecio petasitis, Delairea odorata, Eupatorium auriculatum (now Senecio deltoideus, E. fulvum, Mikania ternifolia var. senecioides, Senecio andryaloides, S. angulatus, and S. leucanthemifolius subsp. vernalis are typified on specimens preserved at E, F, P, SBT, and UPS, and on images by Lamarck, Lemaire, Sims, and Waldstein & Kitaibel. The type of the name S. pterophorus, as indicated by Iamonico in 2015, was wrongly reported as holotype and need to be corrected to lectotype according to the Art. 9.9 of ICN. The names Cacalia auriculata, Cacalia fimbrillifera (nom. nov., nom. superfl. et illeg. pro Eupatorium auriculatum, Cacalia scandens by Thunberg, Cineraria crassiflora, Eupatorium scandens by Link (nom. illeg., Mikania senecioides (nom. illeg., Senecio auriculatum, and Senecio mikanioides are also investigated and discussed.

  1. Adiabatic Betatron deceleration of ionospheric charged particles: a new explanation for (i) the rapid outflow of ionospheric O ions, and for (ii) the increase of plasma mass density observed in magnetospheric flux tubes during main phases of geomagnetic s

    Science.gov (United States)

    Lemaire, Joseph; Pierrard, Viviane; Darrouzet, Fabien

    2013-04-01

    Using European arrays of magnetometers and the cross-phase analysis to determine magnetic field line resonance frequencies, it has been found by Kale et al. (2009) that the plasma mass density within plasmaspheric flux tubes increased rapidly after the SSC of the Hallowe'en 2003 geomagnetic storms. These observations tend to confirm other independent experimental results, suggesting that heavy ion up-flow from the ionosphere is responsible for the observed plasma density increases during main phases of geomagnetic storms. The aim of our contribution is to point out that, during main phases, reversible Betatron effect induced by the increase of the southward Dst-magnetic field component (|Δ Bz|), diminishes slightly the perpendicular kinetic energy (W?) of charged particles spiraling along field lines. Furthermore, due to the conservation of the first adiabatic invariant (μ = Wm/ Bm) the mirror points of all ionospheric ions and electrons are lifted up to higher altitudes i.e. where the mirror point magnetic field (Bm) is slightly smaller. Note that the change of the mirror point altitude is given by: Δ hm = -1/3 (RE + hm) Δ Bm / Bm. It is independent of the ion species and it does not depend of their kinetic energy. The change of kinetic energy is determined by: Δ Wm = Wm Δ Bm / Bm. Both of these equations have been verified numerically by Lemaire et al. (2005; doi: 10.1016/S0273-1177(03)00099-1) using trajectory calculations in a simple time-dependant B-field model: i.e. the Earth's magnetic dipole, plus an increasing southward B-field component: i.e. the Dst magnetic field whose intensity becomes more and more negative during the main phase of magnetic storms. They showed that a variation of Bz (or Dst) by more than - 50 nT significantly increases the mirror point altitudes by more than 100 km which is about equal to scale height of the plasma density in the topside ionosphere where particles are almost collisionless (see Fig. 2 in Lemaire et al., 2005

  2. Evaluation of ULV applications against Old World sand fly (Diptera: Psychodidae) species in equatorial Kenya.

    Science.gov (United States)

    Britch, Seth C; Linthicum, Kenneth J; Walker, Todd W; Farooq, Muhammad; Gordon, Scott W; Clark, Jeffrey W; Ngere, Francis; Ngonga, Daniel; Chepchieng, Clifford

    2011-11-01

    Reducing populations of phlebotomine sand flies in areas prevalent for human leishmaniases is of ongoing importance to United States military operations and civilian populations in endemic regions. However, not enough is known regarding the efficacy of Department of Defense-approved pesticides and equipment against sand flies; specifically, the potential for ultra-low volume (ULV) pesticide applications to control Old World sand fly vectors. In this study we examine two sprayers, the Terminator ULV and the Grizzly ULV, with UV-labeled Duet and Fyfanon in four combinations against caged Phlebotomus duboscqi (Neveu-Lemaire) and wild sand fly populations in a natural environment in western Kenya. All equipment and Fyfanon have United States military National Stock Numbers and both pesticides are registered with the United States Environmental Protection Agency. Caged sand flies were reared from local P. duboscqi and the area has long been studied because of high incidences of human cutaneous and visceral Leishmania. Patterns of mortality across grids of caged sand flies showed greater efficacy from the Grizzly ULV regardless of chemical. The Terminator ULV performed well with Duet but with a less uniform and overall lower rate of mortality across the spray grid. Sampling of wild populations before and after treatments suggested local population suppression from ULV treatments, as well as a possible repellent effect in nearby untreated areas. Surprisingly, ULV active ingredient deposition inferred from patterns of UV-labeled droplets captured on cotton ribbons adjacent to sand fly cages in spray plots did not match patterns of mortality. We discuss the implications of this study, the first of its kind, for future military preventive medicine activities, including relative performance costs and benefits of larger or smaller sprayers, and the relative stability of ULV-induced mortality patterns in varied or sub-optimal conditions.

  3. Patient dosimetry workshop - Scanner in clinical practice: how to optimize one's protocols (acquisition, interpretation, dosimetry)? - Radiation protection in medical environment; Atelier dosimetrie patient - Scanner en pratique clinique: comment optimiser ses protocoles (acquisition, interpretation, dosimetrie)? - Radioprotection en milieu medical

    Energy Technology Data Exchange (ETDEWEB)

    Valero, M. [Autorite de Surete Nucleaire, 75 Paris (France); Pilleul, F.; Favre, F. [Centre Hospitalier Universitaire, 69 - Lyon (France); Tack, D. [Braine-L' Alleud (Belgium); Etard, C.; Aubert, B.; Roch, P. [Institut de Protection et de Surete Nucleaire 92 - Fontenay aux Roses (France); Sinno-Tellier, S. [Institut de veille sanitaire, 94 - Saint Maurice (France); Gevenois, P.A. [Bruxelles (Belgium); Marelle, P. [77 Bourron Marlotte (France); Noel, A. [54 Vandoeuvre-Les-Nancy (France); Coquel, P. [74 Cran Gevrier (France); Museux, E. [44 Saint Nazaire (France); Lair, F. [75 Paris (France); Francois, A. [69 Sainte Colombe (France); Lemaire, P. [62 Lens (France); Delgoffe, C. [54 Maxeville (France); Puech, J.L. [31 Toulouse (France); Haller Montejo, M. [57 Strasbourg (France); Rousselle, I. [69 Lyon (France); Noel, A. [54 Vandoeuvre-Les-Nancy (France); Pierrat, N.; Lasalle, S.; Brisse, H. [Institut Pierre et Marie Curie, 75 - Paris (France); Guerson, T. [78 - Buc (France); Mertz, L.; Mertz, M.; Wasylczenko, T.; Bietry, J.; Notter, S. [57 Strasbourg (France); Jahnen, A.; Back, C.; Kohler, S.; Harpes, N.

    2010-10-15

    A selection of eleven brief communications given at the 2010 French days of radiology are compiled here and deal with: 1 - patient's dosimetry in classical radiology (Valero, M.); 2 - Oncology: how to optimize monitoring (dosimetry, new response criteria)? (Pilleul, F.; Favre, F.); 3 - Thorax: how to optimize lecture (MPR - Multi-Planar Reformat, MIP - Maximum Intensity Projection, MinIP - minimum intensity projection) and dosimetry? (Braine-L'Alleud); 4 - Medical exposure of the French population to diagnostic techniques in 2007 (Etard, C.; Aubert, B.; Sinno-Tellier, S.); 5 - Doses delivered to patients in radio-diagnostics: status of a national inquiry in the public sector (Etard, C.; Sinno-Tellier, S.; Aubert, B.); 6 - External help for the dose per section optimization in tomodensitometry (Tack, D.; Jahnen, A.; Back, C.; Kohler, S.; Harpes, N.; Gevenois, P.A.); 7 - Diagnostic reference levels (DRL) in radiology and scanography: status and evolution (Roch, P.; Aubert, B.); 8 - What conclusions can be drawn from the analysis of the DRLs in conventional radiology addressed to the CEPPIM (College for the evaluation of professional practices in medical imaging) (Marelle, P.; Coquel, P.; Museux, E.; Lair, F.; Francois, A.; Lemaire, P.; Delgoffe, C.; Puech, J.L.; Haller Montejo, M.); 9 - DRL analysis in scanography, an optimization tool? (Rousselle, I.; Noel, A.); 10 - Iterative reconstruction in scanography: potential dosimetric benefit and impact on image quality (Pierrat, N.; Lasalle, S.; Guerson, T.; Brisse, H.); 11 - Development of a patient's dose optimisation aided system in medical imaging (Mertz, L.; Mertz, M.; Wasylczenko, T.; Bietry, J.; Notter, S.)

  4. Information Management Systems for Cultural Heritage and Conservation of World Heritage Sites. The Silk Roads Case Study

    Directory of Open Access Journals (Sweden)

    Ona Vileikis

    2011-12-01

    Full Text Available This paper discusses the application of Information Management Systems (IMS in cultural heritage. IMS offer a set of tools for understanding, inventorying and documenting national, regional and World Heritage properties.  Information Management Systems can assist State Parties, stakeholders and heritage site managers involved in cultural heritage management and conservation by easily mining, sharing and exchanging information from multiple sources based on international standards. Moreover, they aim to record, manage, visualize, analyze and disseminate heritage information. In close collaboration with five Central Asian countries, namely, Turkmenistan, Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan; a Belgian consortium headed by the Raymond Lemaire International Centre for Conservation (RLICC, K.U.Leuven is developing the Silk Roads Cultural Heritage Resource Information System (CHRIS. This Web-based Information Management System supports the preparation of the Central Asia Silk Roads serial and transnational nominations on the UNESCO World Heritage list. The project has been set up thanks to the financial support of the Belgian Federal Science Policy Office (BELSPO and in collaboration with UNESCO World Heritage Centre in conjunction with the People’s Republic of China and the Japanese Funds-in-Trust UNESCO project. It provides a holistic approach for the recording, documenta tion, protection and monitoring tasks as part of the management of these potential World Heritage Properties. The Silk Roads CHRIS is easily accessible to the general user, presented in a bilingual English and Russian frame and interoperable, i.e. open for other applications to connect to. In this way, all information for the nomination dossiers is easily verified regarding consistency and quality and ready for managing, periodic reporting and monitoring processes in the respect to the property listed. Fina lly, this study provides a general framework to establish

  5. Evidence for impulsive solar wind plasma penetration through the dayside magnetopause

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    R. Lundin

    2003-02-01

    Full Text Available This paper presents in situ observational evidence from the Cluster Ion Spectrometer (CIS on Cluster of injected solar wind "plasma clouds" protruding into the day-side high-latitude magnetopause. The plasma clouds, presumably injected by a transient process through the day-side magnetopause, show characteristics implying a generation mechanism denoted impulsive penetration (Lemaire and Roth, 1978. The injected plasma clouds, hereafter termed "plasma transfer events", (PTEs, (Woch and Lundin, 1991, are temporal in nature and relatively limited in size. They are initially moving inward with a high velocity and a magnetic signature that makes them essentially indistinguishable from regular magnetosheath encounters. Once inside the magnetosphere, however, PTEs are more easily distinguished from magnetopause encounters. The PTEs may still be moving while embedded in an isotropic background of energetic trapped particles but, once inside the magnetosphere, they expand along magnetic field lines. However, they frequently have a significant transverse drift component as well. The drift is localised, thus constituting an excess momentum/motional emf generating electric fields and currents. The induced emf also acts locally, accelerating a pre-existing cold plasma (e.g. Sauvaud et al., 2001. Observations of PTE-signatures range from "active" (strong transverse flow, magnetic turbulence, electric current, local plasma acceleration to "evanescent" (weak flow, weak current signature. PTEs appear to occur independently of Interplanetary Magnetic Field (IMF Bz in the vicinity of the polar cusp region, which is consistent with observations of transient plasma injections observed with mid- and high-altitude satellites (e.g. Woch and Lundin, 1992; Stenuit et al., 2001. However the characteristics of PTEs in the magnetosphere boundary layer differ for southward and northward IMF. The Cluster data available up to now indicate that PTEs penetrate deeper into the

  6. Evidence for impulsive solar wind plasma penetration through the dayside magnetopause

    Directory of Open Access Journals (Sweden)

    R. Lundin

    Full Text Available This paper presents in situ observational evidence from the Cluster Ion Spectrometer (CIS on Cluster of injected solar wind "plasma clouds" protruding into the day-side high-latitude magnetopause. The plasma clouds, presumably injected by a transient process through the day-side magnetopause, show characteristics implying a generation mechanism denoted impulsive penetration (Lemaire and Roth, 1978.

    The injected plasma clouds, hereafter termed "plasma transfer events", (PTEs, (Woch and Lundin, 1991, are temporal in nature and relatively limited in size. They are initially moving inward with a high velocity and a magnetic signature that makes them essentially indistinguishable from regular magnetosheath encounters. Once inside the magnetosphere, however, PTEs are more easily distinguished from magnetopause encounters. The PTEs may still be moving while embedded in an isotropic background of energetic trapped particles but, once inside the magnetosphere, they expand along magnetic field lines. However, they frequently have a significant transverse drift component as well. The drift is localised, thus constituting an excess momentum/motional emf generating electric fields and currents. The induced emf also acts locally, accelerating a pre-existing cold plasma (e.g. Sauvaud et al., 2001. Observations of PTE-signatures range from "active" (strong transverse flow, magnetic turbulence, electric current, local plasma acceleration to "evanescent" (weak flow, weak current signature.

    PTEs appear to occur independently of Interplanetary Magnetic Field (IMF Bz in the vicinity of the polar cusp region, which is consistent with observations of transient plasma injections observed with mid- and high-altitude satellites (e.g. Woch and Lundin, 1992; Stenuit et al., 2001. However the characteristics of PTEs in the magnetosphere boundary layer differ for southward and northward IMF. The Cluster data

  7. Review on hydroxylamine, a precursor to amino-acids

    Science.gov (United States)

    Lemaire, Jean Louis

    2015-08-01

    Does life on earth come from interstellar space (IS)?It has been recently demonstrated that part of the terrestrial water is of IS origin [Cleeves et al. Science 2014]. This raises the question whether materials like amino-acids or their pre-biotic molecular precursors could have been formed and brought to earth in the same way than water. Another question is whether these molecules were formed in the gas phase or through reactions on the surface/volume of ice-covered grains. This may then have occurred in the vicinity of proto-stellar cores or deep into a pristine dense molecular clouds at very low temperatures.As far as bio-related molecules are concerned, chemistry with nitrogen-bearing molecules (like NH3 and NO) is involved. I review recent experimental work showing that hydroxylamine (NH2OH) could be formed either by surface or by volume reactions in conditions close to those prevailing in dense media. They use either electron-UV irradiation of water-ammonia ices [Zheng & Kaiser JCPA 2010] or successive hydrogenation of solid nitric oxide[Congiu, Fedoseev & al. ApJL.2012] or the simple oxidation of ammonia [He, Vidali, Lemaire & Garrod, ApJ, 2015] or the reaction of ammonia with hydroxyl radicals in a rare gas matrix [Zins & Krim, 2014, 69th ISMS]. A step further, the synthesis of the simplest amino-acids, glycine (NH2CH2COOH) and L- or D-alanine (NH2CH3CHCOOH) has already been obtained via reactions in the gas phase involving NH2OH+ [Blagojevic & al. MNRAS 2003].In addition to several earlier models demonstrating that the formation of all these molecules is possible in the gas phase, a new recent three-phase gas-grain chemical kinetics model of hot cores [Garrod ApJ 2013] shows that the results of ammonia oxidation we obtain are plausible by surface/volume reactions.Although none of the aforementioned molecules (except glycine in a sample of cometary origin) has been yet detected in the IS, they all are considered by many observers and modelers as likely

  8. Clinical effects of an oral supplement rich in antioxidants on skin radiance in women

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    Dumoulin M

    2016-10-01

    Full Text Available Marion Dumoulin, David Gaudout, Benoit Lemaire Activ’Inside, Libourne, France Background: Environmental factors impact the skin aging resulting in decrease of skin radiance. Nutrition and particularly antioxidants could help to fight against skin degradation.Objective: The aim of this study was to evaluate the effects of an oral supplement rich in specific antioxidants, SkinAx2TM, on the improvement of the skin radiance in women.Methods: The open-label clinical study enrolled 35 women, aged 40–70, with facial dull complexion. Subjects were supplemented orally with a daily dosage of 150 mg of an antioxidant-rich formulation containing superoxide dismutase-rich melon concentrate, grape seed extract rich in monomers of flavanols, vitamin C, and zinc for 8 weeks. Each subject served as her own control. The C.L.B.T.™ test has been used to evaluate facial skin coloring (C, luminosity (L, brightness (B, and transparency (T involved in skin radiance. Facial skin imperfections have been assessed by clinical assessment. Firmness has been evaluated by clinical assessment and cutometer measurement. Finally, an auto-questionnaire has been carried out in order to evaluate the satisfaction of the subjects concerning different parameters involved in skin radiance and the global efficacy of the supplement.Results: Skin “red pink” and “olive” colors were significantly improved after supplementation (P<0.0001. Luminosity was increased by 25.9% (P<0.0001 whereas brightness and transparency were not affected by the supplementation. Facial skin imperfections were significantly reduced after the antioxidant-rich formulation intake (global reduction: –18.0%; P<0.0001. Indeed, dark circles, redness, and spots significantly diminished after oral treatment. Firmness and elasticity have been shown to be improved. Subjects were globally satisfied by the product (82.4% and have found improvements on their facial skin. Furthermore, 64.7% reported to look

  9. Book Reviews

    Directory of Open Access Journals (Sweden)

    E.Ch.L. van der Vliet

    1982-01-01

    Full Text Available - Rita Bolland, Alfred Bühler, The patola of Gujarat. Double ikat in India. Krebs AG Basel, 1979. Vol. 1, 360 p. tekst, ill. Vol. 2, afb. in kleur en zwart/wit, krt. tab. noten, verkl. woorden. litl., Eberhard Fischer (eds. - Raymond Buve, Hugo G. Nutini, Ritual kinship. The structure and historical development of the Compadrazgo system in rural Tlaxcala, Vol. I. Princeton University Press, N.J., 1980, XVI plus 494 pp., maps, tables, glossary and index., Betty Bell (eds. - Benno Galjart, G.A. Banck, Jagen met een kat... Schaarse middelen en sociale relaties in de Braziliaanse staat Espirito Santo, CEDLA Incidentele publicaties no. 8, CEDLA, Amsterdam 1977. - R.A.L.H. Gunawardana, J. van Goor, Jan Kompanie as schoolmaster: Dutch education in Ceylon, 1690-1795, Historische Studies, Instituut voor Geschiedenis der Rijksuniversiteit te Utrecht, XXIV, Wolters-Noordhoff Groningen, 1978, 205 pp., 3 maps. - Ria Kloppenborg, R.A.L.H. Gunawardana, Robe and plough. Monasticism and economic interest in early medieval Sri Lanka. Association for Asian Studies, Monographs and Papers No. XXXV, University of Arixona Press, Tucson, Arizona, 1979; 377 pages, including bibliography and index. - Els Postel-Coster, Jan van Bremen, Romantropologie - Essays over antropologie en literatuur, Antropologisch-Sociologisch Centrum Universiteit van Amsterdam, 1979., Sjaak van der Geest, Jojada Verrips (eds. - Arie de Ruijter, T. Lemaire, Over de waarde van kulturen. Een inleiding in de kultuurfilosofie. Ambo, Baarn 1976, herdruk 1980. 509 blz. - P. van de Velde, W. Arens, The man-eating myth. Oxford University Press, New York, 1979. XIV + 206 pp., 12 illustrations. - E.Ch.L. van der Vliet, Klaus E. Müller, Geschichte der antiken ethnographie und ethnologischen theoriebildung von den anfängen bis auf die byzantinischen historiographen, Teil II (Studien zur Kulturkunde 52, Wiesbaden: Franza Steiner Verlag, 1980. 563 pp. 11 figs. - J.J. de Wolf, P.T.W. Baxter, Age

  10. Protecting Unesco World Heritage PROPERTIES'S Integrity: the Role of Recording and Documentation in Risk Management for PETRA

    Science.gov (United States)

    Santana Quintero, M.; Cesaro, G.; Ishakat, F.; Vandesande, A.; Vileikis, O.; Vadafari, A.; Paolini, A.; Van Balen, K.; Fakhoury, L.

    2012-07-01

    Risk management - as it has been defined - involves the decision-making process following a risk assessment (Ball, Watt, 2003). It is the process that involves managing to minimize losses and impacts on the significant of historic structures and to reach the balance between gaining and losing opportunities. This contribution explains the "heritage information" platform developed using low-cost recording, documentation and information management tools to serve as container for assessments resulting from the application of a risk methodology at a pilot area of the Petra Archaeological Park, in particular those that permit digitally and cost effective to prepare an adequate baseline record to identify disturbances and threats. Furthermore, this paper will reflect on the issue of mapping the World Heritage property's boundaries by illustrating a methodology developed during the project and further research to overcome the lack of boundaries and buffer zone for the protection of the Petra World Heritage site, as identified in this project. This paper is based on on-going field project from a multidisciplinary team of experts from the Raymond Lemaire International Centre for Conservation (University of Leuven), UNESCO Amman, Petra Development Tourism and Region Authority (PDTRA), and Jordan's Department of Antiquities (DoA), as well as, experts from Jordan. The recording and documentation approach included in this contribution is part of an on-going effort to develop a methodology for mitigating (active and preventive) risks on the Petra Archaeological Park (Jordan). The risk assessment has been performed using non-intrusive techniques, which involve simple global navigation satellite system (GNSS), photography, and structured visual inspection, as well as, a heritage information framework based on Geographic Information Systems. The approach takes into consideration the comparison of vulnerability to sites with the value assessment to prioritize monuments at risk based

  11. Depth Seismic-Migration Modeling Offshore `Tierra Del Fuego', Argentina (54° 25' S)

    Science.gov (United States)

    Comínguez, A. H.; Flores, J.; Tassone, A.

    2007-05-01

    Within the framework of the TESAC Project (Tectonic Evolution of the South America-Scotia plate boundary during the Cenozoic), about 900 km of multichannel seismic reflection profiles were acquired off the Atlantic coast of the Tierra del Fuego Island. The profiles cut across the South America-Scotia plate boundary, a transform margin which traverses in an E-W direction the Island. Data processing and interpretation of a seismic reflection profile is presented in this contribution. A robust post-stack technique involved depth-migration of the seismic section, using an interval-velocity model of the upper Crust adjusted by iterative processing. An interpreted seismic- velocity section (which trends roughly NW-SE), shows a complex superposition of different tectonic structures, with presence of extensional, compressional and transtensional features in the area located to the north of Isla de los Estados. The profile, which crosses the offshore part of the Magallanes fold-and-thrust belt, images the deep structural framework of part of this tectonic province. The identification of acoustic fabrics and seismic discontinuities allowed us to recognize four main units. Overlaying the acoustic basement (Seismic unit 1), there is another unit (Seismic unit 2) which exhibits some reflector packages of high amplitude; this unit must be related to the volcanic and volcaniclastic sequences of Tobífera/Lemaire Fms. The Seismic Unit 3 displays internal reflector configurations of moderate amplitude and continuity and low-to-moderate frequency; the Yaghán/Beauvoir Fms must be the onshore equivalent of this unit. An uppermost seismic layer (Unit 4) may be correlated with the Tertiary sediments of the Magallanes foreland basin which were involved in the fold and thrust belt. A major structure identified in the studied seismic profile is a SE structural high (which involves the units 1, 2 and 3) and a NW down-faulted area. The latter display folds of kilometric size (3-4 km

  12. Magnetic fabric and microstructures across the Andes of Tierra del Fuego, Argentina Fábrica Magnética y Microestructuras a través de los Andes de Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Federico Esteban

    2011-01-01

    Full Text Available An anisotropy of magnetic susceptibility (AMS transect was carried out across the Fuegian Andes, in Argentina, withthe aim of studying its tectonic evolution. Two-hundred and forty oriented samples were collected from 27 sites distributed between the Paso Garibaldi to the north and the Canal Beagle to the south. The study was restricted to the Upper Jurassic Lemaire Formation, with a single site located in the Lower Cretaceous Yahgán Formation. Stu-died rocks comprised basaltic, andesitic, volcaniclastic and sedimentary rocks affected by low-grade metamorphism. AMS measurements were complemented with thin section analyses of representative samples in order to characterize the microstructures and metamorphic assemblages. In general, the magnetic fabric shows dominantoblate shapes and a large variation in the anisotropy degree from 1.04 up to 2. The anomalously high values were observed to be associa-ted to growth of secondary pyrrhotite, which was identified by rock magnetic tests. Magnetic foliation was generally consistent with slaty cleaveage as observed in the field, confirming the tectonic origin of the magnetic fabric. Three geographic domains were distinguished in the study región on the basis of the pattern of the AMS axes distribution. In the northern domain, from Paso Garibaldi to Valle Carbajal, the orientation of the máximum susceptibility axis (κ1, or magnetic lineation, is N-S to NE-SW with modérate plunge towards the S-SW and coincides with previous determination of mineral lineations associated with the Andean deformation and very low grade metamorphism. The magnetic fabric pattern can be correlated with the main deformational phase responsible for the development of slaty cleavage (main Andean deformational phase and the tectonic transport due to progression of the Fuegian fold and thrust belt in the Late Cretaceous. A different character is shown along the Valle Carbajal domain, where subvertical E-W magnetic foliation

  13. High hydrostatic pressure influences the in vitro response to xenobiotics in Dicentrarchus labrax liver.

    Science.gov (United States)

    Lemaire, Benjamin; Mignolet, Eric; Debier, Cathy; Calderon, Pedro Buc; Thomé, Jean Pierre; Rees, Jean François

    2016-04-01

    Hydrostatic pressure (HP) increases by about 1 atmosphere (0.1MPa) for each ten-meter depth increase in the water column. This thermodynamical parameter could well influence the response to and effects of xenobiotics in the deep-sea biota, but this possibility remains largely overlooked. To grasp the extent of HP adaptation in deep-sea fish, comparative studies with living cells of surface species exposed to chemicals at high HP are required. We initially conducted experiments with precision-cut liver slices of a deep-sea fish (Coryphaenoides rupestris), co-exposed for 15h to the aryl hydrocarbon receptor (AhR) agonist 3-methylcholanthrene at HP levels representative of the surface (0.1MPa) and deep-sea (5-15MPa; i.e., 500-1500m depth) environments. The transcript levels of a suite of stress-responsive genes, such as the AhR battery CYP1A, were subsequently measured (Lemaire et al., 2012; Environ. Sci. Technol. 46, 10310-10316). Strikingly, the AhR agonist-mediated increase of CYP1A mRNA content was pressure-dependently reduced in C. rupestris. Here, the same co-exposure scenario was applied for 6 or 15h to liver slices of a surface fish, Dicentrarchus labrax, a coastal species presumably not adapted to high HP. Precision-cut liver slices of D. labrax were also used in 1h co-exposure studies with the pro-oxidant tert-butylhydroperoxide (tBHP) as to investigate the pressure-dependence of the oxidative stress response (i.e., reactive oxygen production, glutathione and lipid peroxidation status). Liver cells remained viable in all experiments (adenosine triphosphate content). High HP precluded the AhR agonist-mediated increase of CYP1A mRNA expression in D. labrax, as well as that of glutathione peroxidase, and significantly reduced that of heat shock protein 70. High HP (1h) also tended per se to increase the level of oxidative stress in liver cells of the surface fish. Trends to an increased resistance to tBHP were also noted. Whether the latter observation truly

  14. A comparison study between observations and simulation results of Barghouthi model for O+ and H+ outflows in the polar wind

    Directory of Open Access Journals (Sweden)

    I. A. Barghouthi

    2011-11-01

    + ions at altitudes below ~7 RE, while it is important for altitudes above 7 RE. For O+ wave particle interaction is very significant at all altitudes. (3 For certain λ⊥ and at points, altitudes, where the ion gyroradius is equal to or less than λ⊥, the effect of wave-particle interactions is independent of the velocity and it depends only on the altitude part of the velocity diffusion coefficient; however, the effect of wave-particle interactions reduce above that point, called saturation point, and the heating process turns to be self-limiting heating. (4 The most interesting result is the appearance of O+ conics and toroids at low altitudes and continue to appear at high altitudes; however, they appear at very high altitudes for H+ ions. We compare quantitatively and qualitatively between the simulation results and the corresponding observations. As a result of many comparisons, we find that the best agreement occurs when λ⊥ equals to 8 km. The quantitative comparisons show that many characteristics of the observations are very close to the simulation results, and the qualitative comparisons between the simulation results for ion outflows and the observations produce very similar behaviors. To our knowledge, most of the comparisons between observations (ion velocity distribution, density, drift velocity, parallel and perpendicular temperatures, anisotropy, etc. and simulations obtained from different models produce few agreements and fail to explain many observations (see Yau et al., 2007; Lemaire et al., 2007; Tam et al., 2007; Su et al., 1998; Engwall et al., 2009. This paper presents many close agreements between observations and simulations obtained by Barghouthi model, for O+ and H+ ions at different altitudes i.e. from 1.7 RE to 13.7 RE.

  15. High hydrostatic pressure influences the in vitro response to xenobiotics in Dicentrarchus labrax liver

    Energy Technology Data Exchange (ETDEWEB)

    Lemaire, Benjamin; Mignolet, Eric; Debier, Cathy [Institut des Sciences de la Vie, Université Catholique de Louvain, Croix du Sud 2, B-1348 Louvain-la-Neuve (Belgium); Calderon, Pedro Buc [Louvain Drug Research Institute, Université Catholique de Louvain, Avenue Mounier 73, B-1200 Woluwé-Saint-Lambert (Belgium); Thomé, Jean Pierre [Laboratoire d’Ecologie Animale et Ecotoxicologie, Université de Liège, Allée du 6 août 15, B-4000 Liège (Belgium); Rees, Jean François, E-mail: jf.rees@uclouvain.be [Institut des Sciences de la Vie, Université Catholique de Louvain, Croix du Sud 2, B-1348 Louvain-la-Neuve (Belgium)

    2016-04-15

    Highlights: • The methodology of precision-cut liver slices was applied to the European seabass. • Liver slices remained viable and functional in short-term co-exposure studies. • CYP1A induction was blocked in slices exposed to an AhR agonist at high pressure. • HSP70 induction was lower in slices exposed to an AhR agonist at high pressure. • Oxidative stress responses to tBHP were less pronounced at high pressure. - Abstract: Hydrostatic pressure (HP) increases by about 1 atmosphere (0.1 MPa) for each ten-meter depth increase in the water column. This thermodynamical parameter could well influence the response to and effects of xenobiotics in the deep-sea biota, but this possibility remains largely overlooked. To grasp the extent of HP adaptation in deep-sea fish, comparative studies with living cells of surface species exposed to chemicals at high HP are required. We initially conducted experiments with precision-cut liver slices of a deep-sea fish (Coryphaenoides rupestris), co-exposed for 15 h to the aryl hydrocarbon receptor (AhR) agonist 3-methylcholanthrene at HP levels representative of the surface (0.1 MPa) and deep-sea (5–15 MPa; i.e., 500–1500 m depth) environments. The transcript levels of a suite of stress-responsive genes, such as the AhR battery CYP1A, were subsequently measured (Lemaire et al., 2012; Environ. Sci. Technol. 46, 10310–10316). Strikingly, the AhR agonist-mediated increase of CYP1A mRNA content was pressure-dependently reduced in C. rupestris. Here, the same co-exposure scenario was applied for 6 or 15 h to liver slices of a surface fish, Dicentrarchus labrax, a coastal species presumably not adapted to high HP. Precision-cut liver slices of D. labrax were also used in 1 h co-exposure studies with the pro-oxidant tert-butylhydroperoxide (tBHP) as to investigate the pressure-dependence of the oxidative stress response (i.e., reactive oxygen production, glutathione and lipid peroxidation status). Liver cells remained

  16. Implementación del modelo de remodelación ósea de Komarova para el estudio de la sensibilidad del proceso de remodelamiento óseo ante cambios en factores locales Model Bone of Komarova Implementation for the sensitivity study of the process of remodelling bony before changes in local factors

    Directory of Open Access Journals (Sweden)

    Aldemar Fonseca-Velásquez

    2009-12-01

    Full Text Available En este artículo se lleva a cabo la implementación del modelo de remodelación ósea de nivel celular planteado por Komarova, usando como herramienta un diagrama de bloques funcionales. El objetivo de esta implementación es hacer un análisis de sensibilidad con respecto a la variación de los parámetros del modelo y determinar la influencia de los factores paracrinos y autocrinos en la formación de osteoclastos y osteoblastos. El modelo se implementó en el paquete comercial Simulink de Matlab R2007b. Se encontró que cada parámetro tiene un rango de funcionamiento bien determinado y que, fuera de él, la estabilidad se pierde y se establecen ganancias o pérdidas de masa ósea que se pueden atribuir a anormalidades sistémicas de los huesos. Este trabajo constituye un avance sobre el tema de remodelación ósea gracias a que, a diferencia de trabajos previos, se incluyen las variaciones de los parámetros propios del proceso de remodelación que llevan a posibles alteraciones de los procesos del metabolismo óseo, lo cual constituye un punto de partida para el estudio de enfermedades y alteraciones de la densidad del hueso, y permite iniciar el modelado de nuevas enfermedades relacionadas con los huesos, como es, por ejemplo, la metástasis ósea. Este estudio, entonces, es un avance con respecto a los trabajos presentados por Komarova y Lemaire y puede explicar fenómenos de metástasis y alteraciones metabólicas como los descritos en Manolagas.In this article the cellular level model of bone remodeling implementation raised by Komarova is carried out, using like tool a functional block diagram. The objective of this implementation is to make an analysis of sensitivity with respect to the variation of the model parameters and to determine the influence of the paracrine and autocrine factors in the osteoclasts and osteoblasts formation. The model was implemented in the commercial package Simulink with Matlab R2007b. We found that each

  17. Autonomy and heteronomy. Integration and sustainability of essential flows in the built environment; Autonomie en heteronomie. Integratie en verduurzaming van essentiele stromen in de gebouwde omgeving

    Energy Technology Data Exchange (ETDEWEB)

    Van Timmeren, A.

    2006-06-23

    specifieke kenmerken van de traditionele paradigmas, lijkt bij een grote groep van de relevante actoren nog te ontbreken. Dit onderzoek benadrukt het belang voor volhoudbaarheid van een wederkerige relatie tussen centrale en decentrale systemen, en de integratie (interconnectie) van oplossingen voor de energie, afval en afvalwatervoorziening. Gesteld kan worden dat differentiatie en flexibiliteit op het gebied van ruimtelijke ordening voorwaardelijk zijn om te kunnen inspelen op de onzekerheden op de lange termijn. Voorkomen moet worden dat het proces van verstedelijking en de uitleg van infrastructurele netwerken, gebaseerd op het op afstand transporteren en oplossen van de essenti stromen, zich los van elkaar ontwikkelen. Een nauwkeurige, integrale (Eu)regionale planning gebaseerd op een combinatie van conventionele (centrale) systemen en toegevoegde decentrale systemen vermindert de risicos van mogelijke impasse als gevolg van onvolhoudbaarheid van de bestaande netwerken en systemen, met alle bijkomende gezondheidsrisicos. De cultuurfilosoof Ton Lemaire stelde hieromtrent waar het op aan komt, is de juiste verhouding te vinden tussen het globale en het lokale. Het lokale zou door de globalisering niet teniet moeten worden gedaan maar opnieuw een plaats moeten krijgen. Een uitwerking van volhoudbaarheid, voorzieningszekerheid en onafhankelijkheid lijkt zowel in geval van verdere ontwikkeling op grond van het toekomstpad van schaalvergroting (economies of scale) als van decentralisatie (scale economy) noodzakelijk, zo niet essentieel. Het komt neer op het beter combineren van voordelen van autonomie en heteronomie.

  18. Seeing Is Believing. Or Is It?

    Science.gov (United States)

    Moore, John W.

    1999-08-01

    Occasionally I get time to read something other than a scientific journal, book, or manuscript. On one such foray I discovered Kenneth Brower's "Photography in the Age of Falsification", which appeared in The Atlantic Monthly in May 1998. Brower described how an editor, who might never have experienced the wildness of nature, could conceive a photograph and assign a photographer to create it. Whether the scene depicted was actually possible often seemed relatively unimportant. The main thing was whether the image would interest viewers. Brower argued that today's vast array of software for manipulating digital versions of photographic images enables what he calls "photofakery" on an unprecedented scale. He described how editors at National Geographic decided to pull an ad that depicted a polar bear in Antarctica (where there are no bears); the ad had been created by digitally superimposing a photograph of a bear in a Cincinnati zoo and a photograph of the Lemaire Channel in Antarctica. According to Brower, "Too few photographers, I think, appreciate how directly the new technology aims at the heart of the credibility that distinguishes this art form from others." Credibility is also one of the hallmarks of science. Science progresses as a result of consensus on what results can be expected from carefully designed and carefully executed experiments and observations. As teachers of chemistry, we have a duty not to fall into the same kinds of traps that have made some photographers uneasy about their profession. And we need to help our students learn to avoid these traps. But it is not that easy, because we also need to capture students' attention and try to make our subject interesting by telling stories or showing phenomena or models that appeal to the imagination. As in the case of photography, defining where imagination begins to usurp reality is difficult. It is therefore a very important issue to wrestle with. Part of Brower's argument against manipulation of

  19. Orbiting observatory SOHO finds source of high-speed "wind" blowing from the Sun

    Science.gov (United States)

    1999-02-01

    ranging from 30,000 km/h at the surface to over 3 million km/h, the solar wind "grows" much faster than grass". "Looking at the spot where the solar wind actually appears is extremely important", says co-author Dr. Philippe Lemaire of the Institut d'Astrophysique Spatiale in Orsay, France. The Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on SOHO detected the solar wind by observing the ultraviolet spectrum over a large area of the solar north polar region. The SUMER instrument was built under the leadership of Dr. Klaus Wilhelm at the Max-Planck-Institut für Aeronomie in Lindau, Germany, with key contributions from the Institut d'Astrophysique Spatiale in Orsay, France, the NASA Goddard Space Flight Center in Greenbelt, Maryland, and the University of California at Berkeley, with financial support from German, French, US and Swiss national agencies. "Identification of the detailed structure of the source region of the fast solar wind is an important step in solving the solar wind acceleration problem. We can now focus our attention on the plasma conditions and the dynamic processes seen in the corners of the magnetic field structures", says Dr. Wilhelm, also co-author of the Science paper. A spectrum results from the separation of light into its component colours, which correspond to different wavelengths. Blue light has a shorter wavelength and is more energetic than red. A spectrum is similar to what is seen when a prism separates white light into a rainbow of distinct colours. By analysing light this way, astronomers learn a great deal about the object emitting the light, such as its temperature, chemical composition, and motion. The ultraviolet light observed by SUMER is actually invisible to the human eye and cannot penetrate the Earth's atmosphere. The hot gas in the solar wind source region emits light at certain ultraviolet wavelengths. When the hot gas flows towards Earth, as it does in the solar wind, the wavelengths of the