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Sample records for capitate glandular trichomes

  1. Capitate glandular trichomes in Aldama discolor (Heliantheae - Asteraceae): morphology, metabolite profile and sesquiterpene biosynthesis.

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    Bombo, A B; Appezzato-da-Glória, B; Aschenbrenner, A-K; Spring, O

    2016-05-01

    The capitate glandular trichome is the most common type described in Asteraceae species. It is known for its ability to produce various plant metabolites of ecological and economic importance, among which sesquiterpene lactones are predominant. In this paper, we applied microscopy, phytochemical and molecular genetics techniques to characterise the capitate glandular trichome in Aldama discolor, a native Brazilian species of Asteraceae, with pharmacological potential. It was found that formation of trichomes on leaf primordia of germinating seeds starts between 24 h and 48 h after radicle growth indicates germination. The start of metabolic activity of trichomes was indicated by separation of the cuticle from the cell wall of secretory cells at the trichome tip after 72 h. This coincided with the accumulation of budlein A, the major sesquiterpene lactone of A. discolor capitate glandular trichomes, in extracts of leaf primordia after 96 h. In the same timeframe of 72-96 h post-germination, gene expression studies showed up-regulation of the putative germacrene A synthase (pGAS2) and putative germacrene A oxidase (pGAO) of A. discolor in the transcriptome of these samples, indicating the start of sesquiterpene lactone biosynthesis. Sequencing of the two genes revealed high similarity to HaGAS and HaGAO from sunflower, which shows that key steps of this pathway are highly conserved. The processes of trichome differentiation, metabolic activity and genetic regulation in A. discolor and in sunflower appear to be typical for other species of the subtribe Helianthinae. PMID:26642998

  2. Glandular Trichomes and Essential Oil of Thymus quinquecostatus

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    Ping Jia; Hanzhu Liu; Ting Gao; Hua Xin

    2013-01-01

    The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, co...

  3. Localization of sesquiterpene lactone biosynthesis in cells of capitate glandular trichomes of Helianthus annuus (Asteraceae).

    Science.gov (United States)

    Amrehn, Evelyn; Aschenbrenner, Anna-Katharina; Heller, Annerose; Spring, Otmar

    2016-03-01

    Capitate glandular trichomes (CGT) of sunflower, Helianthus annuus, synthesize bioactive sesquiterpene lactones (STLs) within a short period of only a few days during trichome development. In the current project, the subcellular localization of H. annuus germacrene A monooxygenase (HaGAO), a key enzyme of the STL biosynthesis in sunflower CGT, was investigated. A polyclonal antibody raised against this enzyme was used for immunolabelling. HaGAO was found in secretory and stalk cells of CGT. This correlated with the appearance of smooth endoplasmic reticulum in both cell types. Stalk cells and secretory cells differed in form, size and types of plastids, but both had structures necessary for secretion. No HaGAO-specific immunoreaction was found in sunflower leaf tissue outside of CGT or in developing CGT before the secretory phase had started. Our results indicated that not only secretory cells but also nearly all cells of the CGT were involved in the biosynthesis of STL and that this process was not linked to the presence or absence of a specific type of plastid. PMID:25956500

  4. Identification, functional characterization and developmental regulation of sesquiterpene synthases from sunflower capitate glandular trichomes

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    Ro Dae-Kyun

    2009-07-01

    Full Text Available Abstract Background Sesquiterpene lactones are characteristic metabolites of Asteraceae (or Compositae which often display potent bioactivities and are sequestered in specialized organs such as laticifers, resin ducts, and trichomes. For characterization of sunflower sesquiterpene synthases we employed a simple method to isolate pure trichomes from anther appendages which facilitated the identification of these genes and investigation of their enzymatic functions and expression patterns during trichome development. Results Glandular trichomes of sunflower (Helianthus annuus L. were isolated, and their RNA was extracted to investigate the initial steps of sesquiterpene lactone biosynthesis. Reverse transcription-PCR experiments led to the identification of three sesquiterpene synthases. By combination of in vitro and in vivo characterization of sesquiterpene synthase gene products in Escherichia coli and Saccharomyces cerevisiae, respectively, two enzymes were identified as germacrene A synthases, the key enzymes of sesquiterpene lactone biosynthesis. Due to the very low in vitro activity, the third enzyme was expressed in vivo in yeast as a thioredoxin-fusion protein for functional characterization. In in vivo assays, it was identified as a multiproduct enzyme with the volatile sesquiterpene hydrocarbon δ-cadinene as one of the two main products with α-muuorlene, β-caryophyllene, α-humulene and α-copaene as minor products. The second main compound remained unidentified. For expression studies, glandular trichomes from the anther appendages of sunflower florets were isolated in particular developmental stages from the pre- to the post-secretory phase. All three sesquiterpene synthases were solely upregulated during the biosynthetically active stages of the trichomes. Expression in different aerial plant parts coincided with occurrence and maturity of trichomes. Young roots with root hairs showed expression of the sesquiterpene synthase genes

  5. Glandular Trichomes and Essential Oil of Thymus quinquecostatus

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    Ping Jia

    2013-01-01

    Full Text Available The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, consisting of a unicellular base, a 1–2-celled stalk and a unicellular head, are distributed more diffusely than peltate ones, existing on stem, leaf, rachis and calyx. Digitiform trichomes are just distributed on the outer side of corolla, consisting of 1 basal cell, 3 stalk cells and 1 head cell. All three types of glandular trichomes can secrete essential oil, and in small capitate trichomes of rachis, all peltate trichomes and digitiform trichomes, essential oil is stored in a large subcuticular space, released by cuticle rupture, whereas, in other capitate trichomes, essential oil crosses the thin cuticle. The essential oil of T. quinquecostatus is yellow, and its content is highest in the growth period. 68 constituents were identified in the essential oils. The main constituent is linalool.

  6. Morphological differentiation of non-glandular and glandular trichomes on Marrubium vulgare L.

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    Marta Dmitruk

    2014-04-01

    Full Text Available Marrubium vulgare L., commonly known as a white horehound or common horehound, belongs to the plant family Lamiaceae. It is a perennial aromatic herb which grows naturally in Europe, Asia, and America. Since ancient Egypt, this species has been known as a remedy for upper respiratory tract ailments. Nowadays, horehound is used in herbal medicine for treatment of liver diseases, biliary tract disorders, and for increasing the appetite and supporting the function of the stomach. The main biologically active substances in M. vulgare organs are: marrubiin, tannins, essential oils, and ursolic acid. The paper presents micromorphological analyses of non-glandular and glandular trichomes of M. vulgare. The research material was sampled from the plant collection in the Botanical Garden of the Maria Curie-Sklodowska University in Lublin (51°14′ N, 22°34′ E. The above-ground parts of horehound were collected during the flowering period in July 2013. Using light microscopy (LM and scanning electron microscopy (SEM, the types and sizes of trichomes from the stem, leaf, calyx, and corolla were investigated. The results of the microscopic observations show that the surfaces of M. vulgare vegetative and reproductive organs are densely clothed with glandular and non-glandular trichomes. The glandular trichomes are of two main types: peltate and capitate. Peltate trichomes consist of a short stalk cell and a large head with secretory cells arranged in a circle. The height of a mature trichome is about 31.33 μm and the diameter of the head is 31.47 μm. The substance produced by secretory cells passes through the apical walls and accumulates within a space between the cuticle and the cell wall layer. Capitate long trichomes with a basal cell, long stalk, neck cell, and a unicellular head are 36.65 μm long and the diameter of the head is about 15.6 μm. There are two types of short capitate trichomes: with a bicellular head and a unicellular stalk and with

  7. Morphological differentiation and distribution of non-glandular and glandular trichomes on Dracocephalum moldavicum L. shoots

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The structure, micromorphology and distribution of trichomes on Dracocephalum moldavicum L. shots were investigated using light and scanning electron microscopy (SEM. There were distinguished 3 types of non-glandular trichomes, 3 types of glandular trichomes and papillae of the osmophore in the epidermis of the corolla. The highest density of non-glandular and glandular trichomes was found on the abaxial surface of the calyx, on bracts and in the upper part of the stem. Structural variations in the head and stalk of long glandular trichomes were demonstrated. The dimensions of particular types of trichomes are given in the present paper. Differences in the structure of the trichomes of this species are presented, compared to literature data. The micromorphology of particular trichome types is documented in numerous photographs showing the rich ornamentation of the cuticle of non-glandular trichomes.

  8. The nonvolatile metabolome of sunflower linear glandular trichomes.

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    Spring, Otmar; Pfannstiel, Jens; Klaiber, Iris; Conrad, Jürgen; Beifuß, Uwe; Apel, Lysanne; Aschenbrenner, Anna-Katharina; Zipper, Reinhard

    2015-11-01

    Uniseriate linear glandular trichomes occur on stems, leaves and flowering parts of Helianthus species and related taxa. Their metabolic activity and biological function are still poorly understood. A phytochemical study documented the accumulation of bisabolene type sesquiterpenes and flavonoids as the major constituents of the non-volatile metabolome of linear glandular trichomes in the common sunflower, Helianthus annuus. Besides known sesquiterpenes of the glandulone, helibisabonol and heliannuol type, four previously undescribed sesquiterpenes named glandulone D, E, F and helibisabonol C were identified by spectroscopic analysis. In addition, four known nevadensin type flavonoids varying in O-methoxy substitutions were found. None of them has previously been reported from Helianthus annuus. PMID:26412774

  9. The structure and distribution of glandular trichomes on the stems and leaves of drug eyebright (Euphrasia stricta D. Wolff ex J. F. Lehm.

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available Euphrasia stricta is a medicinal plant being one of the ingredients of "Herba Euphrasiae". Many studies have been devoted to the identification of biologically active substances in the herb of eyebright, but much less research has been done on the constitution of glandular structures of this taxon. This paper relates to glandular trichomes located on the stems and leaves of E. stricta. The trichome structure was examined using light and scanning electron microscopy. It was shown that the stems of E. stricta were mainly covered by non-glandular trichomes, whereas glandular trichomes were rarely found on them. However, clusters of short capitate trichomes were found to occur in specific epidermal regions on both surfaces of the leaf blades and bracts. On the adaxial leaf surface, glandular trichomes grew only in the grooves above the vascular bundles, while on the abaxial surface in the depressions located in the expanded part of the teeth. The glandular hairs consisted of 1-2 cells of the stalk and a two-celled head. Trichomes with 3- or 4-celled heads were found sporadically. The glandular trichomes functioned non-synchronously, since they differed in head size and the colour of cell protoplasts. The presence of a light secretion was found on the surface and around the trichomes in both fresh and dry plant material.

  10. Structure and distribution of glandular and non-glandular trichomes on above-ground organs in Inula helenium L. (Asteraceae

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    Aneta Sulborska

    2014-01-01

    Full Text Available Micromorphology and distribution of glandular and non-glandular trichomes on the above-ground organs of Inula helenium L. were investigated using light and scanning electron microscopy (SEM. Two types of biseriate glandular trichomes, i.e. sessile and stalk hairs, and non-glandular trichomes were recorded. Sessile glandular trichomes were found on all examined I. helenium organs (with their highest density on the abaxial surface of leaves and disk florets, and on stems, whereas stalk glandular trichomes were found on leaves and stems. Sessile trichomes were characterised by a slightly lower height (58–103 μm and width (32–35 μm than the stalk trichomes (62–111 μm x 31–36 μm. Glandular hairs were composed of 5–7 (sessile trichomes or 6–9 (stalk trichomes cell tiers. Apical trichome cell tiers exhibited features of secretory cells. Secretion was accumulated in subcuticular space, which expanded and ruptured at the top, and released its content. Histochemical assays showed the presence of lipids and polyphenols, whereas no starch was detected. Non-glandular trichomes were seen on involucral bracts, leaves and stems (more frequently on involucral bracts. Their structure comprised 2–9 cells; basal cells (1–6 were smaller and linearly arranged, while apical cells had a prozenchymatous shape. The apical cell was the longest and sharply pointed. Applied histochemical tests revealed orange-red (presence of lipids and brow colour (presence of polyphenols in the apical cells of the trichomes. This may suggest that beside their protective role, the trichomes may participate in secretion of secondary metabolites.

  11. Genetic basis for glandular trichome formation in cotton.

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    Ma, Dan; Hu, Yan; Yang, Changqing; Liu, Bingliang; Fang, Lei; Wan, Qun; Liang, Wenhua; Mei, Gaofu; Wang, Lingjian; Wang, Haiping; Ding, Linyun; Dong, Chenguang; Pan, Mengqiao; Chen, Jiedan; Wang, Sen; Chen, Shuqi; Cai, Caiping; Zhu, Xiefei; Guan, Xueying; Zhou, Baoliang; Zhu, Shuijin; Wang, Jiawei; Guo, Wangzhen; Chen, Xiaoya; Zhang, Tianzhen

    2016-01-01

    Trichomes originate from epidermal cells and can be classified as either glandular or non-glandular. Gossypium species are characterized by the presence of small and darkly pigmented lysigenous glands that contain large amounts of gossypol. Here, using a dominant glandless mutant, we characterize GoPGF, which encodes a basic helix-loop-helix domain-containing transcription factor, that we propose is a positive regulator of gland formation. Silencing GoPGF leads to a completely glandless phenotype. A single nucleotide insertion in GoPGF, introducing a premature stop codon is found in the duplicate recessive glandless mutant (gl2gl3). The characterization of GoPGF helps to unravel the regulatory network of glandular structure biogenesis, and has implications for understanding the production of secondary metabolites in glands. It also provides a potential molecular basis to generate glandless seed and glanded cotton to not only supply fibre and oil but also provide a source of protein for human consumption. PMID:26795254

  12. Engineering of Tomato Glandular Trichomes for the Production of Specialized Metabolites.

    Science.gov (United States)

    Kortbeek, R W J; Xu, J; Ramirez, A; Spyropoulou, E; Diergaarde, P; Otten-Bruggeman, I; de Both, M; Nagel, R; Schmidt, A; Schuurink, R C; Bleeker, P M

    2016-01-01

    Glandular trichomes are specialized tissues on the epidermis of many plant species. On tomato they synthesize, store, and emit a variety of metabolites such as terpenoids, which play a role in the interaction with insects. Glandular trichomes are excellent tissues for studying the biosynthesis of specialized plant metabolites and are especially suitable targets for metabolic engineering. Here we describe the strategy for engineering tomato glandular trichomes, first with a transient expression system to provide proof of trichome specificity of selected promoters. Using microparticle bombardment, the trichome specificity of a terpene-synthase promoter could be validated in a relatively fast way. Second, we describe a method for stable expression of genes of interest in trichomes. Trichome-specific expression of another terpene-synthase promoter driving the yellow-fluorescence protein-gene is presented. Finally, we describe a case of the overexpression of farnesyl diphosphate synthase (FPS), specifically in tomato glandular trichomes, providing an important precursor in the biosynthetic pathway of sesquiterpenoids. FPS was targeted to the plastid aiming to engineer sesquiterpenoid production, but interestingly leading to a loss of monoterpenoid production in the transgenic tomato trichomes. With this example we show that trichomes are amenable to engineering though, even with knowledge of a biochemical pathway, the result of such engineering can be unexpected. PMID:27480691

  13. Micromorphology and histochemistry of leaf trichomes of Salvia aegyptiaca (Lamiaceae

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    Janošević Dušica

    2016-01-01

    Full Text Available We performed a comprehensive study of trichomes considering the medicinal importance of the essential oils produced in glandular trichomes of Salvia aegyptiaca L. and lack of data about leaf trichome characteristics. Micromorphological and histochemical analyses of the trichomes of S. aegyptiaca were carried out using light and scanning electron microscopy. We report that the leaves contained abundant non-glandular unbranched trichomes and two types of glandular trichomes, peltate and capitate, on both leaf surfaces. The abaxial leaf side was covered with numerous peltate and capitate trichomes, while capitate trichomes were more abundant on the adaxial leaf side, where peltate trichomes were rarely observed. The non-glandular trichomes were unicellular papillae and multicellular, uniseriate, two-to-six-celled, erect or slightly leaning toward the epidermis. Peltate trichomes were composed of a basal cell, a short cylindrical stalk cell and a broad head of eight secretory cells arranged in a single circle. Capitate trichomes consisted of a one-celled glandular head, subtended by a stalk of variable length, and classified into two types: capitate trichomes type I (or short-stalked glandular trichomes and capitate trichomes type II (or long-stalked glandular trichomes. Histochemical tests showed that the secreted material in all types of S. aegyptiaca glandular trichomes was of a complex nature. Positive reactions to lipids for both types of glandular trichomes were obtained, with especially abundant secretion observed in peltate and capitate trichomes type II. [Projekat Ministarstva nauke Republike Srbije, br. 173015 i br. 173029

  14. Caracterização e ontogenia dos tricomas glandulares de Ocimum selloi Benth. - Lamiaceae Characterization and ontogeny of the glandular trichomes of Ocimum selloi Benth. (Lamiaceae

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    Letícia de Almeida Gonçalves

    2010-12-01

    Full Text Available Ocimum selloi Benth. (Lamiaceae é uma espécie nativa da América do Sul e na medicina popular tem sido usada devido suas propriedades analgésica, anti-inflamatória e antiespasmódica. O objetivo do presente trabalho foi identificar os tipos de tricomas glandulares que ocorrem nos órgãos vegetativos e reprodutivos de O. selloi e determinar a ontogenia desses tricomas. Ramos laterais em início de formação, folhas totalmente expandidas, flores em diferentes estádios de diferenciação, amostras de caule e do eixo das inflorescências foram analisados em microscopias de luz e eletrônica de varredura. Tricomas glandulares do tipo peltado e capitado subséssil foram observados no caule, nas folhas, no eixo da inflorescência e na superfície adaxial das sépalas. Nas sépalas foi encontrado, além dos tricomas secretores peltados e capitados subsésseis, o tricoma glandular capitado pedunculado. A ontogenia inicia-se com a expansão de uma célula protodérmica que, de acordo com a seqüência de divisões periclinais e anticlinais (ora simétricas, ora assimétricas, dá origem aos tricomas. A diferenciação dos tricomas glandulares peltados e capitados não é sincrônica e ocorre muito cedo no desenvolvimento da folha, do caule e do eixo floral.Ocimum selloi Benth. (Lamiaceae is native to South America and in traditional medicine has been used due to its analgesic, anti-inflammatory, and antispasmodic properties. The aim of this study was to identify the types of glandular trichomes that occur on the vegetative and reproductive organs of O. selloi and to determine trichome ontogeny. Lateral branches at the initial formation phase, fully opened leaves, flowers at different differentiation stages, and stem and inflorescence axes were analyzed under light and scanning electron microscopy. Glandular trichomes of the peltate and subsessile capitate types were observed on the stem, leaves, inflorescence axis and the adaxial surface of the

  15. Morphology and histochemistry of glandular trichomes of Orobanche alba Stephan ex Willd

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    Aneta Sulborska

    2014-04-01

    Full Text Available Orobanche alba Stephan ex Willd is an achlorophyllous root parasite rare in Poland. It prefers dry and sunny slopes, xerothermic grasslands and pastures, mountain pastures, light scrubs, and rock fissures and ledges. The hosts of O. alba include Thymus polytrichus A. ern. ex Borbás, Clinopodium vulgare L. and Origanum vulgare L. The tick and fleshy 10-70 cm high stem in this species bears an inflorescence composed of zygomorphic, white or yellow “spotted” flowers covered by purple glandular trichomes. Glandular trichomes of this type are also borne on other parts of the plant, i.e. on the stem, scaly leaves, sepals, filaments, and the style. The secondary metabolites secreted by the glandular trichomes are related to defense of plants against the attack of herbivores and pathogens or act as attractants to pollinators or for fruit dispersal. The micromorphology and histochemistry of the glandular trichomes in O. alba were examined using scanning electron and light microscopes. In order to determine the type of secondary metabolites produced by the trichomes, the flowing histochemical assays were used: Sudan III and neutral red for detection of lipophilic compounds, IKI for detection of starch, and FeCl3 for detection of phenolic compounds. The peltate glandular trichomes of O. alba were characterised by a varied length (0.15‑0.48 mm and different activity phases. The trichome was composed of one larger basal epidermal cell, 1-3 hyaline stalk cells with a striated cuticle, a neck cell with a smooth cuticle on the surface, and a globose head formed of 8-18 secretory cells arranged in a circle. Many stalk cells of the trichomes, particularly those located on the corolla, contained anthocyanins, which give the trichomes dark carmine colour. In turn, the colour of the heads was dependent on trichome age: the heads were brown in older trichomes and yellow in younger hairs. Secretion was produced by both young and older trichomes. It penetrated

  16. Physiological function of non-glandular trichomes in red clover (Trifolium pratense L.

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    Naydenova Galina K.

    2013-01-01

    Full Text Available The objective of the trial was to study the physiological function and potential ecological significance of non-glandular trichomes in red clover based on their relation to the leaf transpiration intensity. The transpiration rate, relative water content and water deficit of the leaves were recorded in field-grown, high and slightly pubescent genotypes. According to results, the presence of nonglandular epidermal trichomes on the leaf surface of red clover was a micromorphological trait related to the regulation of leaf transpiration in stressful conditions. Non-glandular trichomes significantly enhanced water retention of the leaf tissue at high leaf water deficit. In the environmental conditions, limiting leaf evaporation, the pubescent genotypes displayed higher levels of transpiration. It can be suggested that the non-glandular trichomes in red clover are morphological structures supporting the function of leaf stoma apparatus. A positive relation between the degree of pubescence and resistance to powdery mildew was established under natural conditions.

  17. Next generation sequencing unravels the biosynthetic ability of Spearmint (Mentha spicata) peltate glandular trichomes through comparative transcriptomics

    OpenAIRE

    Jin, Jingjing; Panicker, Deepa; Wang, Qian; Kim, Mi Jung; Liu, Jun; Yin, Jun-Lin; Wong, Limsoon; Jang, In-Cheol; Chua, Nam-Hai; Sarojam, Rajani

    2014-01-01

    Background Plant glandular trichomes are chemical factories with specialized metabolic capabilities to produce diverse compounds. Aromatic mint plants produce valuable essential oil in specialised glandular trichomes known as peltate glandular trichomes (PGT). Here, we performed next generation transcriptome sequencing of different tissues of Mentha spicata (spearmint) to identify differentially expressed transcripts specific to PGT. Our results provide a comprehensive overview of PGT’s dynam...

  18. Higher glandular trichome density in tomato leaflets and repellence to spider mites

    Energy Technology Data Exchange (ETDEWEB)

    Maluf, Wilson Roberto; Inoue, Irene Fumi; Ferreira, Raphael de Paula Duarte; Gomes, Luiz Antonio Augusto [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Agricultura]. E-mail: wrmaluf@ufla.br; fuminoue@yahoo.com.br; raphaelufla@yahoo.com.br; laagomes@ufla.br; Castro, Evaristo Mauro de [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Biologia]. E-mail: emcastro@ufla.br; Cardoso, Maria das Gracas [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Quimica]. E-mail: mcardoso@ufla.br

    2007-09-15

    The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII), and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI) decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence) to spider mites. (author)

  19. Higher glandular trichome density in tomato leaflets and repellence to spider mites

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII), and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI) decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence) to spider mites. (author)

  20. Peltate glandular trichomes of Colquhounia seguinii harbor new defensive clerodane diterpenoids.

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    Li, Chun-Huan; Liu, Yan; Hua, Juan; Luo, Shi-Hong; Li, Sheng-Hong

    2014-09-01

    Glandular trichomes produce a wide variety of secondary metabolites that are considered as major defensive chemicals against herbivore attack. The morphology and secondary metabolites of the peltate glandular trichomes of a lianoid Labiatae, Colquhounia seguinii Vaniot, were investigated. Three new clerodane diterpenoids, seguiniilactones A-C (1-3), were identified through precise trichome collection with laser microdissection, metabolic analysis with ultra performance liquid chromatography-tandem mass spectrometer, target compound isolation with classical phytochemical techniques, structure elucidation with spectroscopic methods. All compounds showed significant antifeedant activity against a generalist plant-feeding insect Spodoptera exigua. Seguiniilactone A (1) was approximately 17-fold more potent than the commercial neem oil. α-Substituted α,β-unsaturated γ-lactone functionality was found to be crucial for strong antifeedant activity of this class of compounds. Quantitative results indicated that the levels of these compounds in the peltate glandular trichomes and leaves were sufficiently high to deter the feeding by generalist insects. Moderate antifungal activity was observed for seguiniilactone C (3) against six predominant fungal species isolated from the diseased leaves of C. seguinii, while seguiniilactones A and B were generally inactive. These findings suggested that seguiniilactones A-C might be specialized secondary metabolites in peltate glandular trichomes for the plant defense against insect herbivores and pathogens. PMID:25048077

  1. Peltate glandular trichomes of Colquhounia seguinii harbor new defensive clerodane diterpenoids

    Institute of Scientific and Technical Information of China (English)

    Chun-Huan Li; Yan Liu; Juan Hua; Shi-Hong Luo; Sheng-Hong Li

    2014-01-01

    Glandular trichomes produce a wide variety of secondary metabolites that are considered as major defen-sive chemicals against herbivore attack. The morphology and secondary metabolites of the peltate glandular trichomes of a lianoid Labiatae, Colquhounia seguinii Vaniot, were investigated. Three new clerodane diterpenoids, seguiniilac-tones A-C (1-3), were identified through precise trichome collection with laser microdissection, metabolic analysis with ultra performance liquid chromatography-tandem mass spectrometer, target compound isolation with classical phytochemical techniques, structure elucidation with spec-troscopic methods. All compounds showed significant antifeedant activity against a generalist plant-feeding insect Spodoptera exigua. Seguiniilactone A (1) was approxi-mately 17-fold more potent than the commercial neem oil. a-Substituted a,b-unsaturated g-lactone functionality was found to be crucial for strong antifeedant activity of this class of compounds. Quantitative results indicated that the levels of these compounds in the peltate glandular trichomes and leaves were sufficiently high to deter the feeding by generalist insects. Moderate antifungal activity was ob-served for seguiniilactone C (3) against six predominant fungal species isolated from the diseased leaves of C. seguinii, while seguiniilactones A and B were generally inactive. These findings suggested that seguiniilactones A-C might be specialized secondary metabolites in peltate glandular trichomes for the plant defense against insect herbivores and pathogens.

  2. Biochemical and histochemical localization of monoterpene biosynthesis in the glandular trichomes of spearmint (Mentha spicata)

    Energy Technology Data Exchange (ETDEWEB)

    Gershenzon, J.; Maffei, M.; Croteau, R. (Washington State Univ., Pullman (USA))

    1989-04-01

    The primary monoterpene accumulated in the glandular trichomes of spearmint (Mentha spicata) is the ketone (-)-carvone which is formed by cyclization of the C{sub 10} isoprenoid intermediate geranyl pyrophosphate to the olefin (-)-limonene, hydroxylation to (-)-trans-carveol and subsequent dehydrogenation. Selective extraction of the contents of the glandular trichomes indicated that essentially all of the cyclase and hydroxylase activities resided in these structures, whereas only about 30% of the carveol dehydrogenase was located here with the remainder located in the rest of the leaf. This distribution of carveol dehydrogenase activity was confirmed by histochemical methods. Electrophoretic analysis of the partially purified carveol dehydrogenase from extracts of both the glands and the leaves following gland removal indicated the presence of a unique carveol dehydrogenase species in the glandular trichomes, suggesting that the other dehydrogenase found throughout the leaf probably utilizes carveol only as an adventitious substrate. These results demonstrate that carvone biosynthesis takes place exclusively in the glandular trichomes in which this natural product accumulates.

  3. Morphology and Histochemistry of the Glandular Trichomes of Isodon rubescens (Hemsley) H.Hara (Lamiaceae)%冬凌草腺毛的形态学及组织化学研究

    Institute of Scientific and Technical Information of China (English)

    刘孟奇; 杨世勇; 李寒冰

    2011-01-01

    The morphology and distribution of leaf trichomes of Isodon rubescens were studied using light microscopy. (l)Three morphologically distinct types of trichomes were observed on I. Rubescens leaf surfaces: non-glandular, peltate and capitate glandular. The glandular and non-glandular trichomes were present on both the adaxial and abaxial surfaces. Peltate and capitate glandular trichomes comprised one basal cell,one or two stalk cells and one head. The head of mature peltate glandular trichomes generally consisted of four secretory cells while that of capitate glandular hairs was composed of two cells. (2)Histochemical results indicate existence of flavnoids in both peltate and capitate glandular trichomes. In addition, terpe-noids,including monoterpenes, sesquiterpenes etc. , exist in peltate glandular trichomes. Peltate glandular trichomes are probably only site of oridonin accumulation,however,this need direct proof to clarify. High density of peltate trichomes might be considered as an important selection character for the screening of I. Rubescens with rich content of oridonin.%利用光学显微镜对药用植物冬凌草地上部分腺毛的形态、分布和组织化学进行了研究.结果表明:(1)冬凌草的叶表皮有3种形态显著不同的毛,即非腺毛、盾状腺毛和头状腺毛;盾状腺毛和头状腺毛均具1个基细胞、1个柄细胞和头部;成熟的盾状腺毛的头部一般由4个分泌细胞组成,而头状腺毛头部由2个分泌细胞组成.(2)组织化学鉴定结果显示:2种腺毛中均含有黄酮类成分,盾状腺毛中还含有单萜、倍半萜等萜类成分;冬凌草甲素可能只存在于盾状腺毛中,但需要更直接的证据证明.研究认为,高密度的盾状腺毛可以作为筛选冬凌草高甲素含量品种的一项重要依据.

  4. Development and Structure of Internal Glands and External Glandular Trichomes in Pogostemon cablin

    OpenAIRE

    Guo, Jiansheng; Yuan, Yongming; Liu, Zhixue; Zhu, Jian

    2013-01-01

    Pogostemon cablin possesses two morphologically and ontogenetically different types of glandular trichomes, one type of bristle hair on the surfaces of leaves and stems and one type of internal gland inside the leaves and stems. The internal gland originates from elementary meristem and is associated with the biosynthesis of oils present inside the leaves and stems. However, there is little information on mechanism for the oil biosynthesis and secretion inside the leaves and stems. In this st...

  5. Autofluorescence as a Signal to Sort Developing Glandular Trichomes by Flow Cytometry.

    Science.gov (United States)

    Bergau, Nick; Navarette Santos, Alexander; Henning, Anja; Balcke, Gerd U; Tissier, Alain

    2016-01-01

    The industrial relevance of a number of metabolites produced in plant glandular trichomes (GTs) has spurred research on these specialized organs for a number of years. Most of the research, however, has focused on the elucidation of secondary metabolite pathways and comparatively little has been undertaken on the development and differentiation of GTs. One way to gain insight into these developmental processes is to generate stage-specific transcriptome and metabolome data. The difficulty for this resides in the isolation of early stages of development of the GTs. Here we describe a method for the separation and isolation of intact young and mature type VI trichomes from the wild tomato species Solanum habrochaites. The final and key step of the method uses cell sorting based on distinct autofluorescence signals of the young and mature trichomes. We demonstrate that sorting by flow cytometry allows recovering pure fractions of young and mature trichomes. Furthermore, we show that the sorted trichomes can be used for transcript and metabolite analyses. Because many plant tissues or cells have distinct autofluorescence components, the principles of this method can be generally applicable for the isolation of specific cell types without prior labeling. PMID:27446176

  6. Rupture of glandular trichomes in Ocimum gratissimum leaves influences the content of essential oil during the drying method

    OpenAIRE

    Ana Carolina M. de Santana; Gabriel S. Pereira; Camila M. Boaventura; Ana Paula T. Uetenabaro; Larissa C. do B. Costa; Rosilene A. de Oliveira

    2014-01-01

    Medicinal and aromatic plants are commonly sold dried; however, it is necessary to understand the effects different drying methods have on these materials, to ensure their efficiency and quality. Ocimum gratissimum L., Lamiaceae, is an aromatic plant whose essential oil is stored in glandular trichomes. This study aimed to confirm the effects of different drying temperatures and methods of O. gratissimum leaves on trichome integrity and essential oil content. Leaves dried in a forced ventilat...

  7. Development and structure of internal glands and external glandular trichomes in Pogostemon cablin.

    Directory of Open Access Journals (Sweden)

    Jiansheng Guo

    Full Text Available Pogostemon cablin possesses two morphologically and ontogenetically different types of glandular trichomes, one type of bristle hair on the surfaces of leaves and stems and one type of internal gland inside the leaves and stems. The internal gland originates from elementary meristem and is associated with the biosynthesis of oils present inside the leaves and stems. However, there is little information on mechanism for the oil biosynthesis and secretion inside the leaves and stems. In this study, we identified three kinds of glandular trichome types and two kinds of internal gland in the Pogostemon cablin. The oil secretions from internal glands of stems and leaves contained lipids, flavones and terpenes. Our results indicated that endoplasmic reticulum and plastids and vacuoles are likely involved in the biosynthesis of oils in the internal glands and the synthesized oils are transported from endoplasmic reticulum to the cell wall via connecting endoplasmic reticulum membranes to the plasma membrane. And the comparative analysis of the development, distribution, histochemistry and ultrastructures of the internal and external glands in Pogostemon cablin leads us to propose that the internal gland may be a novel secretory structure which is different from external glands.

  8. Identifying three ecological chemotypes of Xanthium strumarium glandular trichomes using a combined NMR and LC-MS method.

    Directory of Open Access Journals (Sweden)

    Fangfang Chen

    Full Text Available Xanthanolides, as the sesquiterpene lactones, are reportedly the major components for the pharmacological properties of X. strumarium L. species. Phytochemical studies indicated that the glandular structures on the surface of plant tissues would form the primary sites for the accumulation of this class of the compounds. As the interface between plants and their natural enemies, glandular trichomes may vary with respect to which of their chemicals are sequestered against different herbivores in different ecologies. However, to date, no data are available on the chemical characterisation of X. strumarium glandular cells. In this study, the trichome secretions of the X. strumarium species originating from nineteen unique areas across eleven provinces in China, were analysed by HPLC, LC-ESI-MS and NMR. For the first time three distinct chemotypes of X. strumarium glandular trichomes were discovered along with the qualitative and quantitative evaluations of their presence of xanthanolides; these were designated glandular cell Types I, II, and III, respectively. The main xanthanolides in Type I cells were 8-epi-xanthatin and xanthumin while no xanthatin was detected. Xanthatin, 8-epi-xanthatin, and xanthumin dominated in Type II cells with comparable levels of each being present. For Type III cells, significantly higher concentrations of 8-epi-xanthatin or xanthinosin (relative to xanthatin were detected with xanthinosin only being observed in this type. Further research will focus on understanding the ecological and molecular mechanism causing these chemotype differences in X. strumarium glandular structures.

  9. Identifying three ecological chemotypes of Xanthium strumarium glandular trichomes using a combined NMR and LC-MS method.

    Science.gov (United States)

    Chen, Fangfang; Hao, Fuhua; Li, Changfu; Gou, Junbo; Lu, Dayan; Gong, Fujun; Tang, Huiru; Zhang, Yansheng

    2013-01-01

    Xanthanolides, as the sesquiterpene lactones, are reportedly the major components for the pharmacological properties of X. strumarium L. species. Phytochemical studies indicated that the glandular structures on the surface of plant tissues would form the primary sites for the accumulation of this class of the compounds. As the interface between plants and their natural enemies, glandular trichomes may vary with respect to which of their chemicals are sequestered against different herbivores in different ecologies. However, to date, no data are available on the chemical characterisation of X. strumarium glandular cells. In this study, the trichome secretions of the X. strumarium species originating from nineteen unique areas across eleven provinces in China, were analysed by HPLC, LC-ESI-MS and NMR. For the first time three distinct chemotypes of X. strumarium glandular trichomes were discovered along with the qualitative and quantitative evaluations of their presence of xanthanolides; these were designated glandular cell Types I, II, and III, respectively. The main xanthanolides in Type I cells were 8-epi-xanthatin and xanthumin while no xanthatin was detected. Xanthatin, 8-epi-xanthatin, and xanthumin dominated in Type II cells with comparable levels of each being present. For Type III cells, significantly higher concentrations of 8-epi-xanthatin or xanthinosin (relative to xanthatin) were detected with xanthinosin only being observed in this type. Further research will focus on understanding the ecological and molecular mechanism causing these chemotype differences in X. strumarium glandular structures. PMID:24098541

  10. Rupture of glandular trichomes in Ocimum gratissimum leaves influences the content of essential oil during the drying method

    Directory of Open Access Journals (Sweden)

    Ana Carolina M. de Santana

    2014-10-01

    Full Text Available Medicinal and aromatic plants are commonly sold dried; however, it is necessary to understand the effects different drying methods have on these materials, to ensure their efficiency and quality. Ocimum gratissimum L., Lamiaceae, is an aromatic plant whose essential oil is stored in glandular trichomes. This study aimed to confirm the effects of different drying temperatures and methods of O. gratissimum leaves on trichome integrity and essential oil content. Leaves dried in a forced ventilation oven at 60ºC display damaged trichomes and a reduction in the essential oil content. The different drying methods (oven, dehumidification and air drying were not identified to elicit changes in the essential oil content or damage to trichomes. All of the drying methods showed a reduction in fungal contamination in a logarithmic cycle.

  11. Micromorphology and ultrastructure of trichomes of Libyan Salvia fruticosa Mill.

    Directory of Open Access Journals (Sweden)

    Al Sheef Beleed Najat

    2013-01-01

    Full Text Available Micromorphological and ultrastructural analyses of the leaf trichomes of Salvia fruticosa Mill. were performed by light and electron microscopy. The leaves bear numerous non-glandular unbranched trichomes, and peltate, capitate and digitiform glandular trichomes. Very elongated flagelliform non-glandular trichomes densely covered the leaf surfaces, with especially abundance on the leaf margins. Peltate trichomes consist of a basal epidermal cell, a very short stalk cell and a large round head of eight secretory cells arranged in a circle. Capitate trichomes can be divided into two main types, short-stalked and long-stalked, and further into five subtypes according to the number of stalk cells, morphology and number of glandular head cells. Digitiform trichomes consist of one basal cell, one or two stalk cells and one apical secretory cell, which are of similar diameter and approximately equal length. [Projekat Ministarstva nauke Republike Srbije, br. 173029 i br. 173015

  12. A proposal for chemical characterization and quality evaluation of botanical raw materials using glandular trichome microsampling of yacón (Polymnia sonchifolia, Asteraceae), an Andean medicinal plant

    OpenAIRE

    K. Schorr; F.B. Da Costa

    2003-01-01

    A proposal for chemical characterisation and quality evaluation of botanical raw materials by analysing the glandular trichomes from the leaves of two different populations of yacón (Polymnia sonchifolia Poeppig & Endlicher, Asteraceae) is described. This species is an Andean medicinal plant and the tea prepared with their leaves displays hypoglycemic property. The method was based on the glandular trichome microsampling using LC/DAD. Qualitative chromatographic fingerprints of the glands wer...

  13. Negative ion 'chip-based' nanospray tandem mass spectrometry for the analysis of flavonoids in glandular trichomes of Lychnophora ericoides Mart. (Asteraceae).

    Science.gov (United States)

    Gobbo-Neto, Leonardo; Gates, Paul J; Lopes, Norberto P

    2008-12-01

    This paper reports a method for the analysis of secondary metabolites stored in glandular trichomes, employing negative ion 'chip-based' nanospray tandem mass spectrometry. The analyses of glandular trichomes from Lychnophora ericoides, a plant endemic to the Brazilian 'cerrado' and used in traditional medicine as an anti-inflammatory and analgesic agent, led to the identification of five flavonoids (chrysin, pinocembrin, pinostrobin, pinobanksin and 3-O-acetylpinobanksin) by direct infusion of the extracts of glandular trichomes into the nanospray ionisation source. All the flavonoids have no oxidation at ring B, which resulted in a modification of the fragmentation pathways compared with that of the oxidised 3,4-dihydroflavonoids already described in the literature. The absence of the anti-inflammatory and antioxidant di-C-glucosylflavone vicenin-2, or any other flavonoid glycosides, in the glandular trichomes was also demonstrated. The use of the 'chip-based' nanospray QqTOF apparatus is a new fast and useful tool for the identification of secondary metabolites stored in the glandular trichomes, which can be useful for chemotaxonomic studies based on metabolites from glandular trichomes. PMID:18980260

  14. Papel dos tricomas glandulares da folha do tomateiro na oviposição de Tuta absoluta Role of tomato leaf glandular trichomes on oviposition of Tuta absoluta

    Directory of Open Access Journals (Sweden)

    Elsa Gilardón

    2001-03-01

    Full Text Available Os tricomas glandulares presentes nas folhas e ramos das plantas do gênero Lycopersicon são responsáveis pela secreção de metabólitos de diferentes naturezas. A presença de alguns desses compostos tem sido associada à resistência do tomate a diferentes insetos. A traça-do-tomateiro, Tuta absoluta (Meyrick, é uma das pragas mais nocivas da América do Sul. O adulto oviposita sobre as folhas do tomate e suas larvas abrem galerias no mesófilo das folhas, ramos, flores e frutos. As espécies silvestres do tomate conservam a capacidade de biossintetizar compostos químicos que lhes conferem resistência a esta praga. No presente trabalho, foi avaliada a preferência para oviposição desse inseto sobre folhas com e sem tricomas glandulares de L. esculentum (Mill. cv. Uco Plata, suscetível, e de L. hirsutum f. glabratum (Mull. PI 134417, espécie silvestre afim ao tomate, e resistente à traça. Os resultados sugerem que as fêmeas ovipositam indistintamente sobre as folhas de ambas espécies, independentemente da presença, ou não, dos tricomas glandulares. E a presença destes e de seus exsudatos não têm efeito inibidor na oviposição do inseto.In the genus Lycopersicon, different metabolites are secreted by the glandular trichomes of leaves and stems. These compounds have been associated to different tomato pests resistance. The South American tomato pinworm, Tuta absoluta (Meyrick, is one of the most harmful pests in South America. The females oviposit on tomato leaves and the larvae mine the leaf mesophyl, stems, flowers and fruits. Some wild accessions of Lycopersicon keep their capacity to synthesize allelochemicals that protect them from the pest. In this paper a comparison was made between the tomato pinworm oviposition on leaves with and without trichomes of L. esculentum (Mill. cv. Uco Plata, a susceptible cultivar, and L. hirsutum f. glabratum (Mull. PI 134417, a resistant wild accession. Results suggest that the female

  15. Morphology, distribution, and histochemistry of trichomes of Thymus lykae Degen & Jav. (Lamiaceae)

    OpenAIRE

    Marin Marija; Budimir Snežana; Janošević Dušica; Marin P.D.; Duletić-Laušević Sonja; Ljaljević-Grbić Milica

    2008-01-01

    Micromorphology, distribution, and histochemistry of the trichomes of Thymus lykae were studied using scanning electron microscopy (SEM)and confocal laser scanning electron microscopy (CLSM). The leaves, stem, and calyx bear numerous glandular and non-glandular trichomes. Two types of glandular trichomes are identified - peltate and capitate. Results of histochemical tests showed positive reactions to polysaccharides, proteins, and lipids. Yellow autofluorescence of secreted material was noti...

  16. Identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (Helianthus annuus L., Asteraceae).

    Science.gov (United States)

    Aschenbrenner, Anna-Katharina; Kwon, Moonhyuk; Conrad, Jürgen; Ro, Dae-Kyun; Spring, Otmar

    2016-04-01

    Sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. A bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. Based on sequence similarity with a known bisabolene synthases from Arabidopsis thaliana AtTPS12, candidate genes of Helianthus were searched in EST-database and used to design specific primers. PCR experiments identified two candidates in the RNA pool of linear glandular trichomes of sunflower. Their sequences contained the typical motifs of sesquiterpene synthases and their expression in yeast functionally characterized them as bisabolene synthases. Spectroscopic analysis identified the stereochemistry of the product of both enzymes as (Z)-γ-bisabolene. The origin of the two sunflower bisabolene synthase genes from the transcripts of linear trichomes indicates that they may be involved in the synthesis of sesquiterpenes produced in these trichomes. Comparison of the amino acid sequences of the sunflower bisabolene synthases showed high similarity with sesquiterpene synthases from other Asteracean species and indicated putative evolutionary origin from a β-farnesene synthase. PMID:26880289

  17. Glandular trichome density and essential oil composition in leaves and inflorescences of Lippia origanoides Kunth (Verbenaceae) in the Brazilian Cerrado.

    Science.gov (United States)

    Tozin, Luiz R S; Marques, Marcia O M; Rodrigues, Tatiane M

    2015-01-01

    The essential oils from leaves and inflorescences of Lippia origanoides Kunth present aromatic and medicinal potential and have been used to treat several diseases, including melanoma. In Brazil, L. origanoides is commonly found in campo cerrado and cerrado stricto sensu, physiognomies featured mainly by the differential light conditions to which short and medium-sized plants are subjected. Our aim was to investigate the glandular trichome density and the yield and chemical composition of the essential oils in leaves and inflorescences of L. origanoides from campo cerrado and cerrado stricto sensu. For glandular density analysis, leaves and inflorescences were processed according to conventional techniques for scanning electron microscopy. The essential oils of leaves and inflorescences were obtained by hydrodistillation and identified with gas chromatography. Bracts and sepals showed the highest glandular density, followed by petals and leaves. The glandular density in the abaxial leaf surface was higher in individuals from the campo cerrado. In both populations the essential oil yield was higher in inflorescences than in leaves. The chemical composition of the essential oils varied among individuals from different areas and inside a same population. Our results demonstrated the chemical plasticity of L. origanoides suggesting the importance of monitoring its popular use. PMID:26131639

  18. Higher glandular trichome density in tomato leaflets and repellence to spider mites Alta densidade de tricomas glandulares em tomateiro e aumento da repelência a ácaros rajados

    OpenAIRE

    Wilson Roberto Maluf; Irene Fumi Inoue; Raphael de Paula Duarte Ferreira; Luiz Antonio Augusto Gomes; Evaristo Mauro Castro; Maria das Graças Cardoso

    2007-01-01

    The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. h...

  19. Morphology, distribution, and histochemistry of trichomes of Thymus lykae Degen & Jav. (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Marin Marija

    2008-01-01

    Full Text Available Micromorphology, distribution, and histochemistry of the trichomes of Thymus lykae were studied using scanning electron microscopy (SEMand confocal laser scanning electron microscopy (CLSM. The leaves, stem, and calyx bear numerous glandular and non-glandular trichomes. Two types of glandular trichomes are identified - peltate and capitate. Results of histochemical tests showed positive reactions to polysaccharides, proteins, and lipids. Yellow autofluorescence of secreted material was noticed in peltate and capitate trichomes. Strong reddish-yellow autofluorescence of the lipophilic and hydrophilic secreted material was observed with CLSM.

  20. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis

    OpenAIRE

    Rongyan Fan; Yuanjun Li; Changfu Li; Yansheng Zhang

    2015-01-01

    The medicinal plant Xanthium strumarium L. (X. strumarium) is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs) are a class of 21-24 nucleotide (nt) non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined w...

  1. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis.

    Directory of Open Access Journals (Sweden)

    Rongyan Fan

    Full Text Available The medicinal plant Xanthium strumarium L. (X. strumarium is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs are a class of 21-24 nucleotide (nt non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined with target gene prediction, was performed to discover novel and conserved miRNAs with potential roles in regulating terpenoid biosynthesis in X. strumarium glandular trichomes. Two small RNA libraries from leaves and glandular trichomes of X. strumarium were established. In total, 1,185 conserved miRNAs and 37 novel miRNAs were identified, with 494 conserved miRNAs and 18 novel miRNAs being differentially expressed between the two tissue sources. Based on the X. strumarium transcriptome data that we recently constructed, 3,307 annotated mRNA transcripts were identified as putative targets of the differentially expressed miRNAs. KEGG (Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that some of the differentially expressed miRNAs, including miR6435, miR5021 and miR1134, might be involved in terpenoid biosynthesis in the X. strumarium glandular trichomes. This study provides the first comprehensive analysis of miRNAs in X. strumarium, which forms the basis for further understanding of miRNA-based regulation on terpenoid biosynthesis.

  2. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis.

    Science.gov (United States)

    Fan, Rongyan; Li, Yuanjun; Li, Changfu; Zhang, Yansheng

    2015-01-01

    The medicinal plant Xanthium strumarium L. (X. strumarium) is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs) are a class of 21-24 nucleotide (nt) non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined with target gene prediction, was performed to discover novel and conserved miRNAs with potential roles in regulating terpenoid biosynthesis in X. strumarium glandular trichomes. Two small RNA libraries from leaves and glandular trichomes of X. strumarium were established. In total, 1,185 conserved miRNAs and 37 novel miRNAs were identified, with 494 conserved miRNAs and 18 novel miRNAs being differentially expressed between the two tissue sources. Based on the X. strumarium transcriptome data that we recently constructed, 3,307 annotated mRNA transcripts were identified as putative targets of the differentially expressed miRNAs. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis suggested that some of the differentially expressed miRNAs, including miR6435, miR5021 and miR1134, might be involved in terpenoid biosynthesis in the X. strumarium glandular trichomes. This study provides the first comprehensive analysis of miRNAs in X. strumarium, which forms the basis for further understanding of miRNA-based regulation on terpenoid biosynthesis. PMID:26406988

  3. Characterization of two genes for the biosynthesis of abietane-type diterpenes in rosemary (Rosmarinus officinalis) glandular trichomes

    DEFF Research Database (Denmark)

    Brückner, Kathleen; Božić, Dragana; Manzano, David;

    2014-01-01

    Rosemary (Rosmarinus officinalis) produces the phenolic diterpenes carnosic acid and carnosol, which, in addition to their general antioxidant activities, have recently been suggested as potential ingredients for the prevention and treatment of neurodegenerative diseases. Little is known about the...... biosynthesis of these diterpenes. Here we show that the biosynthesis of phenolic diterpenes in rosemary predominantly takes place in the glandular trichomes of young leaves, and used this feature to identify the first committed steps. Thus, a copalyl diphosphate synthase (RoCPS1) and two kaurene synthase...

  4. A Geranylfarnesyl Diphosphate Synthase Provides the Precursor for Sesterterpenoid (C25) Formation in the Glandular Trichomes of the Mint Species Leucosceptrum canum.

    Science.gov (United States)

    Liu, Yan; Luo, Shi-Hong; Schmidt, Axel; Wang, Guo-Dong; Sun, Gui-Ling; Grant, Marcus; Kuang, Ce; Yang, Min-Jie; Jing, Shu-Xi; Li, Chun-Huan; Schneider, Bernd; Gershenzon, Jonathan; Li, Sheng-Hong

    2016-03-01

    Plant sesterterpenoids, an important class of terpenoids, are widely distributed in various plants, including food crops. However, little is known about their biosynthesis. Here, we cloned and functionally characterized a plant geranylfarnesyl diphosphate synthase (Lc-GFDPS), the enzyme producing the C25 prenyl diphosphate precursor to all sesterterpenoids, from the glandular trichomes of the woody plant Leucosceptrum canum. GFDPS catalyzed the formation of GFDP after expression in Escherichia coli. Overexpressing GFDPS in Arabidopsis thaliana also gave an extract catalyzing GFDP formation. GFDPS was strongly expressed in glandular trichomes, and its transcript profile was completely in accordance with the sesterterpenoid accumulation pattern. GFDPS is localized to the plastids, and inhibitor studies indicated its use of isoprenyl diphosphate substrates supplied by the 2-C-methyl-D-erythritol 4-phosphate pathway. Application of a jasmonate defense hormone induced GFDPS transcript and sesterterpenoid accumulation, while reducing feeding and growth of the generalist insect Spodoptera exigua, suggesting that these C25 terpenoids play a defensive role. Phylogenetic analysis suggested that GFDPS probably evolved from plant geranylgeranyl diphosphate synthase under the influence of positive selection. The isolation of GFDPS provides a model for investigating sesterterpenoid formation in other species and a tool for manipulating the formation of this group in plants and other organisms. PMID:26941091

  5. Analysis of cannabinoids in laser-microdissected trichomes of medicinal Cannabis sativa using LCMS and cryogenic NMR

    NARCIS (Netherlands)

    Happyana, Nizar; Agnolet, Sara; Muntendam, Remco; Van Dam, Annie; Schneider, Bernd; Kayser, Oliver

    2013-01-01

    Trichomes, especially the capitate-stalked glandular hairs, are well known as the main sites of cannabinoid and essential oil production of Cannabis sativa. In this study the distribution and density of various types of Cannabis sativa L trichomes, have been investigated by scanning electron microsc

  6. Papel dos tricomas glandulares da folha do tomateiro na oviposição de Tuta absoluta Role of tomato leaf glandular trichomes on oviposition of Tuta absoluta

    OpenAIRE

    Elsa Gilardón; Mariana Pocovi; Carmen Hernández; Ana Olsen

    2001-01-01

    Os tricomas glandulares presentes nas folhas e ramos das plantas do gênero Lycopersicon são responsáveis pela secreção de metabólitos de diferentes naturezas. A presença de alguns desses compostos tem sido associada à resistência do tomate a diferentes insetos. A traça-do-tomateiro, Tuta absoluta (Meyrick), é uma das pragas mais nocivas da América do Sul. O adulto oviposita sobre as folhas do tomate e suas larvas abrem galerias no mesófilo das folhas, ramos, flores e frutos. As espécies silve...

  7. Caracterização e ontogenia dos tricomas glandulares de Ocimum selloi Benth. - Lamiaceae Characterization and ontogeny of the glandular trichomes of Ocimum selloi Benth. (Lamiaceae)

    OpenAIRE

    Letícia Almeida Gonçalves; Aristéa Alves Azevedo; Wagner Campos Otoni

    2010-01-01

    Ocimum selloi Benth. (Lamiaceae) é uma espécie nativa da América do Sul e na medicina popular tem sido usada devido suas propriedades analgésica, anti-inflamatória e antiespasmódica. O objetivo do presente trabalho foi identificar os tipos de tricomas glandulares que ocorrem nos órgãos vegetativos e reprodutivos de O. selloi e determinar a ontogenia desses tricomas. Ramos laterais em início de formação, folhas totalmente expandidas, flores em diferentes estádios de diferenciação, amostras de ...

  8. Structural features of flower trichomes in drug eyebright (Euphrasia stricta D. Wolff EX J. F. Lehm.

    Directory of Open Access Journals (Sweden)

    Weronika Haratym

    2014-01-01

    Full Text Available Euphrasia stricta D. Wolff ex J. F. Lehm. (Orobanchaceae is a representative of plants that are widely used in folk medicine, phytomedicine, and homeopathy. The medicinal raw material derived from the drug eyebright is applied primarily in treatment of ophthalmic diseases. The investigations of trichomes in drug eyebright (Euphrasia stricta D. Wolff ex J. F. Lehm were conducted in 2010–2011. Using light microscopy and scanning electron microscopy, their location and morphological and anatomical features were identified. Three types of non-glandular trichomes were found: short unicellular, long 1–2 celled, and long 2-celled with wall ornamentation. Additionally, 7 types of glandular trichomes were found; these included: unicellular clavate, 2–3-celled clavate, capitate with a unicellular head and a 3-cel- led stalk, capitate with a unicellular head and a 2-celled stalk, capitate with a 2-celled head, conical papillae, and ribbon-like trichomes with wall thickening.

  9. Influence of life history differences of two tachinid parasitoids ofHelicoverpa zea (Boddie) (Lepidoptera: Noctuidae) on their interactions with glandular trichome/methyl ketone-based insect resistance in tomato.

    Science.gov (United States)

    Farrar, R R; Kennedy, G G; Kashyap, R K

    1992-03-01

    The effects of glandular trichome/methyl ketone (2-tridecanone and 2-undecanone) -based insect resistance in the wild tomato,Lycopersicon hirsutum f.glabratum C.H. Mull, accession PI 134417, onArchytas marmoratus (Townsend) andEucelatoria bryani (Sabrosky) (Diptera: Tachinidae), both parasitoids ofHelicoverpa (=Heliothis)zea (Boddie) (Lepidoptera: Noctuidae), were investigated in the laboratory.A. marmoratus deposits larvae (planidia) on the foliage of its host's food plant; planidia attach to passing hosts, penetrate the cuticle, and develop in the host pupae.E. bryani larviposits directly into its host; its larvae develop in the host larva.A. marmoratus planidia are killed by glandular trichomes of PI 134417 and also by trichomes of hybrid lines with no methyl ketones. The methyl ketones are toxic to planidia, but at least part of the effect is due to other factors, possibly physical entanglement. Both species can be affected indirectly by methyl ketones in the diet of the host. 2-Undecanone reduces the percentage ofA. marmoratus larvae that reach pupation. This effect is evidently due to premature death and desiccation of the host pupa caused by 2-undecanone. 2-Tridecanone in host diets had no effect onA. marmoratus. InE. bryani, 2-tridecanone in the diet of the host reduced the number of parasitoids yielded by each parasitized host, although not the overall percentage of hosts parasitized. 2-Undecanone in the diet of the host had no effect onE. bryani. PMID:24254953

  10. Morphology and biochemistry of non-glandular trichomes in Cistus salvifolius L. leaves growing in extreme habitats of the Mediterranean basin.

    Science.gov (United States)

    Tattini, M; Matteini, P; Saracini, E; Traversi, M L; Giordano, C; Agati, G

    2007-05-01

    Here the functional roles of stellate and dendritic trichomes in Cistus salvifolius L leaves were studied by analysing i) both leaf surface and trichome morphology using scanning electron and light microscopy; and ii) the composition and localisation of polyphenols by coupling liquid chromatography with fluorescence spectroscopy and fluorescence microimaging. Red-coloured compounds were detected in the stalk cells and the channel in the trichome arm, and appeared to be released at the tip end of the trichome branch. We identified such metabolites as ellagitannins, namely punicalagin and two galloyl derivatives of punicalagin. These ellagitannins accounted for 4.3 % of leaf dry weight and their concentration in the leaf leachate averaged 289.4 mg L (-1). The trichome arms exhibited an appreciable orange-red autofluorescence (centred at 620 nm) when excited with UV light (at 365 nm) or emitted in the yellow waveband (peak centred at 566 nm) when stained with the Naturstoff reagent, and excited at 488 nm. The fluorescence signatures of the trichome arms were consistent with the presence of mono-hydroxy B-ring substituted flavonoids, which were identified as the mono- and di-coumaroyl derivative of a kaempferol 3-O-glycoside. Our data may provide some insights on the functional roles of stellate and dendritic trichomes in the response mechanisms of C. salvifolius to Mediterranean-type climate, based upon (i) the potential effect of released ellagitannins on the soil nitrogen dynamic and (ii) the ability of acylated kaempferol 3-O-glycosides to effectively absorb both the UV-B and UV-A wavelengths. PMID:17143807

  11. Papel da 2-tridecanona e dos tricomas glandulares tipo VI na resistência do tomateiro a Tuta absoluta Role of 2-tridecanone and type VI glandular trichome on tomato resistance to Tuta absoluta

    OpenAIRE

    Elsa Gilardón; Mariana Pocovi; Carmen Hernández; Graciela Collavino; Ana Olsen

    2001-01-01

    O metabólito secundário 2-tridecanona, secretado pelos tricomas glandulares tipo VI das folhas de tomateiro silvestre, Lycopersicon hirsutum L., confere-lhe resistência a uma grande variedade de insetos, inclusive a traça-do-tomateiro, Tuta absoluta (Meyrick). O objetivo do trabalho foi avaliar a concentração de 2- tridecanona, a densidade de tricomas glandulares tipo VI e o grau de infestação da traça-do-tomateiro na cultivar suscetível 'Uco Plata' (Lycopersicon esculentum Mill.), na linhage...

  12. Trichomes morphology in petals of some Acanthaceae species.

    Directory of Open Access Journals (Sweden)

    Muhammad Amirul Aiman Ahmad Juhari

    2014-12-01

    Full Text Available A preliminary taxonomic study was carried out on seven Acanthaceae species namely as Andrographis paniculata, Pseuderanthemum graciliflorum, P. carruthersii,  Asystasia gangetica ssp. micrantha, Ruellia repens, Justicia comata and J. betonica. The study was undertaken to    investigate the morphology of trichomes present on the surfaces of flower petal. The variations found in this study are in their types and density. Based on observation, two forms of trichomes are present in all species studies which are glandular and non-glandular trichomes. There are seven types of trichomes found in this study. Trichomes types are shown to have systematic significance that can be used to differentiate and identify certain Acanthaceae species studied. 

  13. Compositions of essential oils and trichomes of Teucrium chamaedrys L. subsp. trapezunticum Rech. fil. and subsp. syspirense (C. Koch) Rech. fil.

    Science.gov (United States)

    Kaya, Ayla; Demirci, Betül; Başer, K Hüsnü C

    2009-01-01

    Teucrium chamaedrys L. is a member of the Lamiaceae family and is represented in the Flora of Turkey by six subspecies. The aerial organs of T. chamaedrys L. subsp. trapezunticum Rech. fil. and subsp. syspirense (C. Koch) Rech. fil. bears numerous eglandular and glandular trichomes. Eglandular trichomes are simple, long-multicellular with cuticular micropapillae, and glandular hairs are of peltate and capitate types. The peltate hairs consist of a basal cell, a short unicellular stalk, and multicellular secretory head, and the capitate ones possess 1-2 stalk cells and one glandular head cell. The aerial parts were subjected to microdistillation for the isolation of volatiles. The analysis was simultaneously performed by using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The major components were characterized as beta-caryophyllene (18%), nonacosane (12%), germacrene D (11%), caryophyllene oxide (7%), and alpha-pinene (7%) for subsp. trapezunticum, and caryophyllene oxide (23%), alpha-pinene (11%), and caryophyllenol II (5%) for subsp. syspirense. PMID:19180459

  14. Micromorphology of trichomes in the flowers of the horse chestnut Aesculus hippocastanum L.

    Directory of Open Access Journals (Sweden)

    Mirosława Chwil

    2014-01-01

    Full Text Available Aesculus hippocastanum L. is an ornamental tree appreciated for its beautiful flowers and leaves. The flowers of this species contain secondary metabolites exhibiting pharmacological activity. They also produce essential oils and coloured “nectar guides”, which enable insects to reach nectar and pollen. The aim of the study was to investigate the types and characteristics of chestnut flower trichomes, which may contain biologically active substances. The analyses were performed using light, fluorescence, and scanning electron microscopy. Three types of trichomes were found on the sepals and the surface of the ovary, whereas the corolla petals exhibited two types of hairs and papillae. The hairs differ in terms of their length and number of cells. The perianth and pistil had no capitate hairs, whereas the ovary exhibited the presence of colleters. Histochemical assays revealed that all the types of trichomes and papillae contained lipids or essential oils; hence, they can be classified as glandular structures. The “nectar guides” were characterised by higher density of secretory hairs than that on the rest of the petal surface, which implies that these petal fragments may emit stronger fragrance.

  15. Trichomes of Cannabis sativa as viewed with scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Ledbetter, M.C.; Krikorian, A.D.

    1975-06-01

    Direct examination of fresh, unfixed and uncoated specimens from vegetative and floral parts of Cannabis sativa with the scanning electron microscope enables one to obtain a faithful representation of their surface morphology. The presence of two major types of trichomes has been confirmed: a glandular type comprising or terminating in a globoid structure, and a conically-shaped nonglandular type. Moreover, three or possibly four distinct glandular types can be distinguished: sessile globoid, small-stalked and large-stalked globoid, and a peltate type. The nonglandular trichomes can be distinguished by the nature of their surfaces: those with a warty surface, and those which are relatively smooth. The range of size and distribution, and the special features of all these types of trichomes are also provided.

  16. Micromorphology of glandular structures in Echium vulgare L. flowers

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The micromorphology of selected elements of Echium vulgare L. flowers was investigated, with special attention to the structure of the nectaries and the stigma of the pistil as well as types of trichomes occurring on the surface of the calyx. The nectary had the shape of an uneven disc located around the lower region of the four-parted ovary of the pistil. The glandular cells formed a tier with a height of 330 μm and a radial width of 144 μm. Nectar was secreted onto the nectary surface through anomocytic stomata located at the level of other epidermal cells. Most of the stomata were open, with a different dimension of the pore. Their largest number was observed at the base of the nectary, and 462 stomata were noted on the whole surface of the nectary. The cuticle on the surface of the guard cells formed fine, circular striae. The subsidiary cells formed striated cuticular ornamentation, with the striae arranged radially in the direction of the stoma, whereas on the surface of other epidermal cells the striae formed an arrangement with different directions. The epidermis on the surface of the stigma formed regularly arranged papillae with a fan-shaped, expanded upper part which had corrugated outer walls, whereas the base of the cell formed a widened small column. The epidermis of the abaxial part of the calyx was covered by numerous non-glandular trichomes of different length which were made up of one or several cells. The glandular trichomes in the epidermis of the calyx grew with smaller density compared to the protective trichomes, and they were composed of a 1-2-celled stalk and a glandular head.

  17. Morphological differentiation of non-glandular and glandular trichomes on Marrubium vulgare L.

    OpenAIRE

    Marta Dmitruk; Weronika Haratym

    2014-01-01

    Marrubium vulgare L., commonly known as a white horehound or common horehound, belongs to the plant family Lamiaceae. It is a perennial aromatic herb which grows naturally in Europe, Asia, and America. Since ancient Egypt, this species has been known as a remedy for upper respiratory tract ailments. Nowadays, horehound is used in herbal medicine for treatment of liver diseases, biliary tract disorders, and for increasing the appetite and supporting the function of the stomach. The main biolog...

  18. Impact of Exogenous Elicitors on Artemisinin Production and Trichome Density in Artemisia annua L. under Subtropical Conditions

    Directory of Open Access Journals (Sweden)

    Alka Jagdish DANGASH

    2014-09-01

    Full Text Available Artemisinin is a sesquiterpene lactone found in Artemisia annua having many medicinal properties. Therefore the factors affecting trichome initiation are important. In the present study, several strategies have been adapted to increase artemisinin production by treating them with nutrients, hormones and elicitors. Abscisic acid, Gibberellic acid (GA3, a combination of GA3+IAA (Gibberellic acid+indole acetic acid, Chitosan, Methyl jasmonate, Acetyl salicylic acid, Lead acetate, sodium chloride, and Nanozime were sprayed on plant at regular intervals. The glandular trichomes of leaves from Artemisia annua (Asteraceae were examined by light and scanning electron microscopy and the percentage artemisnin content was analyzed by HPTLC. Maximum artemisinin content % and trichome index (0.128 was found when methy jasmonate was applied and minimum artemisinin content % and trichome index was reported in NaCl & acetyl salicylic acid.

  19. The effect of roots and media constituents on trichomes and artemisinin production in Artemisia annua L

    OpenAIRE

    Nguyen, Khanhvan T.; Towler, Melissa J.; Weathers, Pamela J.

    2012-01-01

    Artemisia annua produces the antimalarial drug, artemisinin (AN), which is synthesized and stored in glandular trichomes (GLTs). In vitro-grown A. annua shoots produce more AN when they form roots. This may be a function not of the roots, but rather media components such as the phytohormones, α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP), or salts and sucrose used to maintain either rooted or unrooted shoot cultures. We investigated how three main media components altered artem...

  20. A cold-tolerant evergreen interspecific hybrid of Ocimum kilimandscharicum and Ocimum basilicum: analyzing trichomes and molecular variations.

    Science.gov (United States)

    Dhawan, Sunita Singh; Shukla, Preeti; Gupta, Pankhuri; Lal, R K

    2016-05-01

    Ocimum (Lamiaceae) is an important source of essential oils and aroma chemicals especially eugenol, methyl eugenol, linalool, methyl chavicol etc. An elite evergreen hybrid has been developed from Ocimum kilimandscharicum and Ocimum basilicum, which demonstrated adaptive behavior towards cold stress. A comparative molecular analysis has been done through RAPD, AFLP, and ISSR among O. basilicum and O. kilimandscharicum and their evergreen cold-tolerant hybrid. The RAPD and AFLP analyses demonstrated similar results, i.e., the hybrid of O. basilicum and O. kilimandscharicum shares the same cluster with O. kilimandscharicum, while O. basilicum behaves as an outgroup, whereas in ISSR analysis, the hybrid genotype grouped in the same cluster with O. basilicum. Ocimum genotypes were analyzed and compared for their trichome density. There were distinct differences on morphology, distribution, and structure between the two kinds of trichomes, i.e., glandular and non-glandular. Glandular trichomes contain essential oils, polyphenols, flavonoids, and acid polysaccharides. Hair-like trichomes, i.e., non-glandular trichomes, help in keeping the frost away from the living surface cells. O. basilicum showed less number of non-glandular trichomes on leaves compared to O. kilimandscharicum and the evergreen cold-tolerant hybrid. Trichomes were analyzed in O. kilimandscharicum, O. basilicum, and their hybrid. An increased proline content at the biochemical level represents a higher potential to survive in a stress condition like cold stress. In our analysis, the proline content is quite higher in tolerant variety O. kilimandscharicum, low in susceptible variety O. basilicum, and intermediate in the hybrid. Gene expression analysis was done in O. basilicum, O. kilimandscharicum and their hybrid for TTG1, GTL1, and STICHEL gene locus which regulates trichome development and its formation and transcription factors WRKY and MPS involved in the regulation of plant responses to freezing

  1. Trichome morphology in Teucrium L. (Labiatae. A taxonomic review

    Directory of Open Access Journals (Sweden)

    Navarro, Teresa

    1999-12-01

    Full Text Available The micromorphology of trichomes of 56 Teucrium L. species belonging to the 9 sections of the genus in the Mediterranean área was surveyed by scanning electrón microscopy (SEM of leaves, calyx, corolla and nutlets. 25 trichome types are described, 12 of them are new. Thin walled hairs are the exclusive type found in the corolla and are the most widespread type on the abaxial side of the leaves. Subsessile glandular hairs, 2-4-celled, are found on the nutlet and leaves of the semi-shrubby and paleoendemic species. The presence of short or elongated, generally adpressed simple thick-walled slighüy conical hairs provides an additional character to clarify the boundaries between sect. Chamedrys (Mill. Schreb, and sect. Polium (Mill. Schreb. Branched non-glandular hairs are confined to sect. Polium subsect Polium, except for the rare branched hair conical and thick-walled type found in Teucrium barbarum Jahand. & Maire (sect. Chamaedrys and T. heterophyllum L`Hér. from sect. Teucrium. This last section is well defined by the absence of simple slighüy conical thick-walled hairs and the glandular hairs in the corolla. Sect. Teucriopsis Benth, is of particular interest for the exclusive presence of branched and peltate glandular hairs on the nutlets surface. Sect. Chamedrys is a homogeneous group, distinguished from the other sections by an indumentum formed only by trichomes types evolved from the simple slighüy conical thick-walled hairs. This section overlaps, in the presence of glandular sub-sessile hair on the nutlets surface, with sects. Isotriodon Boiss, and sect. Polium subsect. Rotundifolia Cohén ex Valdés Berm. & Sánchez Crespo. The trichomes type of the calyx teeth, abaxial side of the leaf and latero-posterior corolla lobes can be used as a distinctive taxonomic character at specific and infra-specific level. This study supports Bentham's delimitaüon of sections with the addiüons subequently made by Boissier.La micromorfología de

  2. Relação entre zingibereno, tricomas foliares e repelência de tomateiros a Tetranychus evansi Relationship between zingiberene, foliar trichomes and repellence of tomato plant to Tetranychus evansi

    Directory of Open Access Journals (Sweden)

    Luciano Donizete Gonçalves

    2006-02-01

    Full Text Available O objetivo deste trabalho foi quantificar os teores de zingibereno em populações segregantes (F2 do segundo retrocruzamento para Lycopersicon esculentum a partir da espécie selvagem L. hirsutum var. hirsutum, e verificar a relação entre estes teores e a densidade de tricomas glandulares e a repelência a Tetranychus evansi. Na quantificação do zingibereno, utilizou-se um método espectrofotométrico; os tricomas foram contados a partir de cortes paradérmicos e a resistência a ácaros foi avaliada por um bioteste de repelência. A seleção indireta quanto ao teor de zingibereno promoveu aumentos correlacionados no número de tricomas glandulares e na repelência ao ácaro, e o zingibereno nos tricomas glandulares participou efetivamente na resistência aos ácaros. A densidade de tricomas glandulares influencia de maneira determinante os teores de zingibereno, sendo que o tricoma tipo VI destacou-se por apresentar alta correlação com este aleloquímico. Os teores de zingibereno e a sua relação com tricomas glandulares e com a resistência a artrópodos-pragas se mantiveram ao longo dos retrocruzamentos, evidenciando a possibilidade de obtenção de plantas resistentes via seleção indireta para alto teor de zingibereno nos folíolos.The objective of this work was to quantify zingiberene contents in a segregating population (F2 of the second backcross generation to Lycopersicon esculentum after the initial cross with the wild species L. hirsutum var. hirsutum, and to analyse the relationship between zingiberene and both glandular trichome density on tomato leaves and levels of repellence to spider mites Tetranychus evansi. A spectrophotometric assay was used to quantify zingiberene in leaf disks. Trichome counting was made in paradermic preparations of leaf and mite repellence was accessed by a quick thumbtack assay. Indirect selection for high zingiberene contents increased both glandular trichome density and the level of mite

  3. A comparative analysis of stomata and leaf trichome characteristics in Quercus robur L. genotypes

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    Nikolić Nataša P.

    2003-01-01

    Full Text Available The objective of this study was to determine genotype variability of leaf trichome and stoma characteristics. Leaves were sampled from seventeen pedunculate oak (Quercus robur L genotypes originating from clonal seed orchard Banov Brod (Srem, the Vojvodina Province. The pedunculate oak has hypostomatal leaves. Statistically significant differences were found for the dimensions and density of stomata. Genotype variability of stomatal dimensions was less pronounced in comparison with their density (CV = 8.88%. Stomata number ranged from 530 to 791 per mm2 of leaf area; genotypes 18 and 25 could be distinguished from the others for the highest stomata number per leaf unit area, genotype 35 for the lowest number. In all genotypes, only solitary eglandular trichomes were observed on the adaxial leaf surface while both solitary eglandular and uniseriate glandular hairs were present on the abaxial surface. Single glandular trichomes were observed in all genotypes, while some of them were characterized by the presence of two (genotypes 4, 5, 6, 16, 22, 25, 28, 29, 30, 35, 38, 40, and 85 or three (genotypes 16, 25, 35 hairs joined by their basal cells.

  4. Capital

    OpenAIRE

    Coulangeon, Philippe

    2013-01-01

    Empruntée à l’appareil conceptuel de l’économie, la notion de capital désigne en première analyse l’ensemble des ressources dont disposent les individus et les groupes et qui affectent leurs trajectoires, notamment dans les domaines scolaire, professionnel, matrimonial et familial. La sociologie contemporaine se saisit le plus souvent du concept pour en souligner les différentes espèces : capital économique, capital culturel et capital social, principalement. Si le capital économique désigne ...

  5. Trichomes and chemical composition of the volatile oil of Trichogonia cinerea (Gardner) R. M. King & H. Rob. (Eupatorieae, Asteraceae).

    Science.gov (United States)

    Fernandes, Yanne S; Trindade, Luma M P; Rezende, Maria Helena; Paula, José R; Gonçalves, Letícia A

    2016-03-01

    Trichogonia cinerea is endemic to Brazil and occurs in areas of cerrado and campo rupestre. In this study, we characterized the glandular and non-glandular trichomes on the aerial parts of this species, determined the principal events in the development of the former, and identified the main constituents of the volatile oil produced in its aerial organs. Fully expanded leaves, internodes, florets, involucral bracts, and stem apices were used for the characterization of trichomes. Leaves, internodes, florets, and involucral bracts were examined by light microscopy and scanning electron microscopy, whereas stem apices were examined only by light microscopy. Branches in the reproductive phase were used for the extraction and determination of the composition of the volatile oil. The species has three types of glandular trichomes, biseriate vesicular, biseriate pedunculate, and multicellular uniseriate, which secrete volatile oils and phenolic compounds. The major components identified in the volatile oil were 3,5-muuroladiene (39.56%) and butylated hydroxytoluene (13.07%). PMID:26982621

  6. Light affects Varronia curassavica essential oil yield by increasing trichomes frequency

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    Emily V.R. da S. Feijó

    2014-10-01

    Full Text Available Light can act on essential oil yield directly on synthesis of secondary metabolites, or indirectly on plant growth. Varronia curassavica Jacq., Boraginaceae, is a native medicinal species from Brazil known as “erva-baleeira”, with anti-inflammatory activity related to its essential oil. Despite pharmacological evidences of this species and its economic importance for herbal medicine production, little is known about the effect of light on growth and essential oil production. This study aimed to analyze the influence of different irradiances on growth, frequency of trichomes, essential oil yield and composition of V. curassavica. The irradiance affected plant growth, but no significant alteration on leaf biomass was detected. The increase in essential oil content under higher irradiance reflected on essential oil yield, and is associated with higher frequency of glandular, globular trichomes. The essential oil composition, rich in caryophyllene derivatives was affected by irradiance, but α-humulene, the constituent of pharmaceutical interest, remained unchanged.

  7. EST analysis and annotation of transcripts derived from a trichome-specific cDNA library from Salvia fruticosa.

    Science.gov (United States)

    Chatzopoulou, Fani M; Makris, Antonios M; Argiriou, Anagnostis; Degenhardt, Jörg; Kanellis, Angelos K

    2010-05-01

    Greek sage (Salvia fruticosa Mill., Syn. Salvia triloba L.) is appreciated for its essential oil which is used as an aromatic spice and active against a wide range of microorganisms and viruses. The essential oil is dominated by terpenoids and flavonoids which are produced and stored in glandular trichomes on the plant surface. The present study aims to give insights into the metabolic activities of S. fruticosa trichomes on a transcriptome level. A total of 2,304 clones were sequenced from a cDNA library from leaves' trichomes of S. fruticosa. Exclusion of sequences shorter than 100 bp resulted in 1,615 high-quality ESTs with a mean length of 592 bp. Cluster analysis indicated the presence of 197 contigs (908 clones) and 707 singletons, generating a total of 904 unique sequences. Of the 904 unique ESTs, 628 (69.5%) had significant hits in the non-redundant protein database and were annotated. A total of 517 (82.3%) sequences were functionally classified using the gene ontologies (GO) and established pathway associations to 220 (24.3%) sequences in Kyoto encyclopedia of genes and genomes (KEGG). In addition, 52 (5.8%) of the unique ESTs revealed a GO biological term with relation to terpenoid (78 ESTs), phenylpropanoid (43 ESTs), flavonoid (18 ESTs) or alkaloid (10 ESTs) biosynthesis or to P450s (26 ESTs). Expression analysis of a selected set of genes known to be involved in the pathways of secondary metabolite synthesis showed higher expression levels in trichomes, validating the tissue specificity of the analyzed glandular trichome library. PMID:20333525

  8. Proteomics of terpenoid biosynthesis and secretion in trichomes of higher plant species.

    Science.gov (United States)

    Champagne, Antoine; Boutry, Marc

    2016-08-01

    Among the specialized (secondary) plant metabolites, terpenoids represent the most diverse family and are often involved in the defense against pathogens and herbivores. Terpenoids can be produced both constitutively and in response to the environment. At the front line of this defense strategy are the glandular trichomes, which are organs dedicated primarily to the production of specialized metabolites. Mass spectrometry-based proteomics is a powerful tool, which is very useful to investigate enzymes involved in metabolic pathways, such as the synthesis and secretion of terpenoids in glandular trichomes. Here we review the strategies used to investigate the specific roles of these particular organs from non-model plant species, mainly belonging to the Lamiaceae, Solanaceae, and Cannabaceae families. We discuss how proteomics helps to accurately pinpoint candidate proteins to be functionally characterized, and how technological progresses create opportunities for studying low-abundance proteins, such as the ones related to the synthesis and transport of specialized metabolites. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. PMID:26873244

  9. Leaf trichome density may explain herbivory patterns of Actinote sp. (Lepidoptera: Acraeidae) on Liabum mandonii (Asteraceae) in a montane humid forest (Nor Yungas, Bolivia)

    Science.gov (United States)

    Molina-Montenegro, Marco A.; Ávila, Pamela; Hurtado, Rosember; Valdivia, Alejandra I.; Gianoli, Ernesto

    2006-09-01

    Increasing evidence shows that most insect herbivores of tropical forests show specific associations with their hosts. Environmental factors as well as foliar characters can modify insect preference. In the present work, we evaluated in a montane humid forest the preference and herbivory rate of Actinote sp. caterpillars (Lepidoptera: Acraeidae) on mature and young leaves of their specific host plant Liabum mandonii (Asteraceae) in two contrasting sites. Additionally, the density of non-glandular trichomes in young and mature leaves of plant at each site was evaluated. Analysis of variance of herbivory showed significant effects of site, leaf age, and the interaction of these factors. Higher herbivory levels were found on leaves from the site with lower levels of radiation and on mature leaves. On the other hand, trichome density was significantly higher in leaves from the site with higher levels of radiation and in young leaves. This suggests trichomes may explain the observed pattern of herbivory.

  10. Combined metabolome and transcriptome profiling provides new insights into diterpene biosynthesis in S. pomifera glandular trichomes

    DEFF Research Database (Denmark)

    Trikka, Fotini A; Nikolaidis, Alexandros; Ignea, Codruta; Tsaballa, Aphrodite; Tziveleka, Leto-Aikaterini; Ioannou, Efstathia; Roussis, Vassilios; Stea, Eleni A; Božić, Dragana; Argiriou, Anagnostis; Kanellis, Angelos K; Kampranis, Sotirios C; Makris, Antonios M

    2015-01-01

    BACKGROUND: Salvia diterpenes have been found to have health promoting properties. Among them, carnosic acid and carnosol, tanshinones and sclareol are well known for their cardiovascular, antitumor, antiinflammatory and antioxidant activities. However, many of these compounds are not available at...

  11. Media glandular dose in mammography

    International Nuclear Information System (INIS)

    The objective of this work was to determine the media glandular dose of the patients group who most frequently are exposed at mammographic studies in the General Hospital of Zone No. 1 of IMSS in Zacatecas, later to compare this dose with the value that establishes the Mexican Official Standard and to know risk-benefit that a patient is exposed when it is realized studies of this nature. This with the purpose of to know if the patients who are realized this type of studies are exhibited to irradiations of unnecessary way. In order to obtain the media glandular dose, first it was choose the age group of feminine population that is predominant to this suffering. Of the classification of the age group it was determine the frequency of each thickness of mamma, and on the basis of the thickness of the compressed mamma the conditions were registered with it radiates the patient. When having the age and compressed mamma thickness of patient and the voltage, current, anode/filter that uses the mammography equipment for to radiate it was calculated the media glandular dose. The media glandular dose was calculated using two algorithms proposed in literature and thermoluminescent dosemeters. For the case of the thermoluminescent dosemeters were used two phantoms. In this study was detected that the limits, with that they radiate the patients who are exposed at mammographic studies it is by underneath of 3 mGy. Finally, it was detected that the Mexican Official Standard lacks of elements to offer radiological limits for the mammography area, because in this standard they are excluded the radiological limits for anode and filter of Mo/Rh and Rh/Rh. To know the dose applying these anodes and filters is of extreme importance because 85% of the population that is exposed to this studies type was radiated with anode and filter of Mo/Rh and Rh/Rh. (Author)

  12. GLANDULAR HAIRS, NON-GLANDULAR HAIRS, AND ESSENTIAL OILS IN THE WINTER AND SUMMER LEAVES OF THE SEASONALLY DIMORPHIC THYMUS SIBTHORPII (LAMIACEAE

    Directory of Open Access Journals (Sweden)

    BOSABALIDIS ARTEMIOS Michael

    2013-12-01

    Full Text Available The structure and function of the glandular and non-glandular hairs, and also the yield and chemical composition of the essential oils in the winter and summer leaves of the seasonally dimorphic plant Thymus sibthorpii were studied. Glandular hairs comprise peltate hairs only (capitate hairs are missing. Peltate hairs are the sites of essential oil biosynthesis. They are more numerous in the winter leaves than in the summer leaves and consist of a 12-celled secretory head, a unicellular stalk, and an also unicellular epidermal foot. The essential oil of the winter leaves is mainly composed of linalool (42.4%, thymol (7.0%, p-cymene (5.8%, β-caryophyllene (5.7%, borneol (5.6%, and terpinen-4-ol (4.8%. The oil of the summer leaves is principally constituted of p-cymene (25.0%, linalool (19.1%, terpinen-4-ol (8.5% and borneol (8.3%. Non-glandular hairs proliferate in the summer leaves. They are conical in shape and consist of one basal epidermal cell and one apical pointed cell. Glandular and non-glandular hairs are implicated in the chemical and mechanical defense of the plant, respectively.

  13. Hormone-mediated promotion of trichome initiation in plants is conserved but utilizes species- and trichome-specific regulatory mechanisms

    OpenAIRE

    Maes, Lies; Goossens, Alain

    2010-01-01

    Plant trichome initiation is steered by diverse developmental and environmental cues, through molecular mechanisms that remain elusive in most plant species. Using a robust experimental method to investigate the molecular mechanisms by which phytohormones modulate leaf trichome formation, we verified the effect of jasmonates, cytokinins and gibberellins in Arabidopsis (Arabidopsis thaliana). All three phytohormones promoted Arabidopsis trichome initiation, but caused divergent effects on tric...

  14. Analysis of purified glabra3-shapeshifter trichomes reveals a role for NOECK in regulating early trichome morphogenic events.

    Science.gov (United States)

    Gilding, Edward K; Marks, M David

    2010-10-01

    Transcriptome analysis using the Affymetrix ATH1 platform has been completed on purified trichomes from the gl3-sst mutant. These trichomes display immature features, such as glassy cell walls and blunted branches. The gl3-sst trichome transcriptome was greatly enriched for genes involved in lipid biosynthesis, including those mediating the synthesis of fatty acids and wax. In addition, gl3-sst trichomes displayed reduced expression of the R3 MYBs TRY and CPC, which normally function to limit trichome development. The expression of the MIXTA-like MYB gene NOK was elevated. Members of the MIXTA-like family promote conical cell outgrowth, and in some cases, trichome initiation in diverse plant species. In contrast, NOK limits trichome outgrowth in wild-type Arabidopsis plants. Similar to other MIXTA-like genes, NOK was required for the expansion of gl3-sst trichomes, as the gl3-sst nok double mutant trichomes were greatly reduced in size. Expression of NOK in nok mutants reduced branch formation, whereas in gl3-sst nok, NOK expression promoted trichome cell outgrowth, illustrating duel roles for NOK in both promoting and limiting trichome development. MIXTA-like genes from phylogenetically diverse plant species could substitute for NOK in both nok and gl3-sst nok backgrounds. These findings suggest that certain aspects of NOK and MIXTA-like gene function have been conserved. PMID:21070410

  15. Proteomic snapshot of spearmint (Mentha spicata L.) leaf trichomes: a genuine terpenoid factory.

    Science.gov (United States)

    Champagne, Antoine; Boutry, Marc

    2013-11-01

    Peltate glandular trichomes from Mentha spicata were purified on a Percoll gradient and soluble and membrane proteins were trypsinized and the peptides were separated by nano-LC fractionation and analyzed by MALDI-MS/MS. The vast majority of the 1666 proteins identified were housekeeping proteins or involved in the primary metabolism. However, 57 were predicted to be involved in the secondary metabolism. Of these, 21 were involved in the synthesis of phenylpropanoids and phenolics and 32 in terpenoid synthesis. Of the 14 membrane transporters identified, the 11 ATP-binding cassette transporters provide good material for assessing whether active transport is required for the transfer of monoterpenoid intermediates between cellular compartments and for the secretion of the final products into the subcuticular storage cavity. In conclusion, this proteome analysis of M. spicata peltate trichomes has identified several candidate proteins that might be involved in terpenoid synthesis and transport. The data have been deposited to the ProteomeXchange with identifier PXD000352 (http://proteomecentral.proteomexchange.org/dataset/PXD000352). PMID:24124164

  16. Caracterização morfológica dos tricomas foliares e caulinares de duas espécies de Lamiaceae conhecidas popularmente como “falsoboldo” = Morphological characterization of the trichomes on the leaves and stem of two Lamiaceae species known popularly as “false-boldus”

    Directory of Open Access Journals (Sweden)

    Mariza Barion Romagnolo

    2007-04-01

    morphologically similar, but differ with regard to dimensions. The glandular trichomes found were: peltate, short-capitate and long-capitate; and tectors (simple uniseriate with two or more cells in the base. With few exceptions, all five trichomes types were observed in the leaves, petiole and stem, and the averages obtained for P. grandis significantly were superior to the ones found in the P.barbatus organs, except for the trichome simple tector which was more abundant in the stem of the second specie.

  17. Lead Accummulation Potential By Leaves With Abundant Trichomes (Muntingia Calabura L.) And Rare Trichomes (Mimusops Elengi L.) In Makassar, Indonesia

    OpenAIRE

    Suhadiyah, Sri

    2013-01-01

    A study of lead accumulation by leaves with abundant trichomes (Muntingia calabura L.) and leaves with rare trichomes (Mimusop elengi L.) in Makassar, Indonesia was conducted in August 2011 by using wet ashing method and Atomic Absorption Spectrophotometer. The objective of this study was to find out the influence of trichome abundance on lead accumulation in shade trees. Results from multiple regression analysis with interval level of 95% indicated a significant correlation between lead (Pb)...

  18. Glandular and non-glandular hairs in the seasonally dimorphic Origanum dictamnus L. (Lamiaceae as a means of adaptation to cold stress

    Directory of Open Access Journals (Sweden)

    Artemios M. Bosabalidis

    2014-04-01

    Full Text Available Origanum dictamnus is a seasonally dimorphic plant having different appearance in winter and summer. Shoots of winter plants are leaf-naked except for their apical region which bears a cluster of small leaves covered with a thick indumentum of non-glandular hairs. This indumentum highly contributes to the avoidance of cold penetration into the leaf mesophyll, allowing thus plants to endure winter low temperatures. Shoots of summer plants are vigorous with large green leaves. Non-glandular hairs are dendroid with a 5-celled vertical stub and several lateral branches. Glandular hairs are of two types, large peltate hairs and small capitate hairs. Peltate hairs are numerous and consist of a 12-celled head, a unicellular stalk, and a basal epidermal cell.. They constitute the sites of essential oil secretion. Capitate hairs occur in a small number and are composed of a unicellular head, a unicellular stalk and a basal epidermal cell. They are not secreting essential oil, but a hydrophilic material. The oil secreted by the peltate hairs has antioxidant properties, opposes the oxidative stress resulted from low temperatures, and contributes to the adaptation of the plant to winter cold stress.

  19. Caracterização morfológica dos tricomas foliares e caulinares de duas espécies de Lamiaceae conhecidas popularmente como “falso-boldo” - DOI: 10.4025/actascibiolsci.v29i2.445 Morphological characterization of the trichomes on the leaves and stem of two Lamiaceae species known popularly as “false-boldus” - DOI: 10.4025/actascibiolsci.v29i2.445

    Directory of Open Access Journals (Sweden)

    Livia Santos Capel

    2007-12-01

    are morphologically similar, but differ with regard to dimensions. The glandular trichomes found were: peltate, short-capitate and long-capitate; and tectors (simple uniseriate with two or more cells in the base. With few exceptions, all five trichomes types were observed in the leaves, petiole and stem, and the averages obtained for P. grandis significantly were superior to the ones found in the P. barbatus organs, except for the trichome simple tector which was more abundant in the stem of the second specie.

  20. Role of trichome of Pteris vittata L. in arsenic hyperaccumulation

    Institute of Scientific and Technical Information of China (English)

    LI; Wenxue; CHEN; Tongbin; CHEN; Yang; LEI; Mei

    2005-01-01

    Environmental scanning electron microscope (ESEM) fitted with an energy dispersive X-ray microanalyzer (EDX) was used to investigate the surface micromorphology and arsenic (As) micro-distribution in Chinese brake (Pteris vittata L.). It was found that amounts of trichome, which possessed multicellular structure with the average length of 160 (m and with an average diameter of 28 (m, existed in the frond of P. vittata, and the density of trichome on the pinnate axial surface was higher than that on the petiole. Visible X-ray peak of As was recorded in the epidermal cell and trichome. The relative weight of As in the pinnate trichome, which contained the highest concentration of As among all tissues of the plant, was 2.4 and 3.9 times as much as that in the epidermal and mesophyllous cells, respectively. The As concentrations in the basal and stalk cells of the same trichome were higher than that in its cap cell. This is the first time to report that the trichome of P. vittata plays an important role in arsenic hyperaccumulation. The finding from the present study implies that much attention should be paid to the role of the trichome in understanding the hyperaccumulation and detoxicity of As in the hyperaccumulator and improving the ability of As accumulation.

  1. Transcriptome Analysis of Arabidopsis Wild-Type and g13-sst sim Trichomes Identifies Four Additional Genes Required for Trichome Development

    Institute of Scientific and Technical Information of China (English)

    M.David Marks; Jonathan R Wenger; Edward Gilding; Ross Jilk; Richard A.Dixon

    2009-01-01

    Transcriptome analyses have been performed on mature trichomes isolated from wild-type Arabidopsis leaves and on leaf trichomes isolated from the g13-sst sire double mutant,which exhibit many attributes of immature trichomes.The mature trichome profile contained many highly expressed genes involved in cell wall synthesis,protein turnover,and abiotic stress response.The most highly expressed genes in the g13-sst sim profile encoded ribosomal proteins and other proteins involved in translation.Comparative analyses showed that all but one of the genes encoding transcription factors previously found to be important for trichome formation,and many other trichome-important genes,were preferentially expressed in g13-sstsim trichomes.The analysis of genes preferentially expressed in g13-sstsim led to the identification of four additional genes required for normal trichome development.One of these was the HDG2 gene,which is a member of the HD-ZIP IV transcription factor gene family.Mutations in this gene did not alter trichome expansion,but did alter mature trichome cell walls.Mutations in BLT resulted in a loss of trichome branch formation.The relationship between bit and the phenotypically identical mutant,sti,was explored.Mutations in PEL3,which was previously shown to be required for development of the leaf cuticle,resulted in the occasional tangling of expanding trichomes.Mutations in another gene encoding a protein with an unknown function altered trichome branch formation.

  2. Acylsugar Acylhydrolases: Carboxylesterase-Catalyzed Hydrolysis of Acylsugars in Tomato Trichomes.

    Science.gov (United States)

    Schilmiller, Anthony L; Gilgallon, Karin; Ghosh, Banibrata; Jones, A Daniel; Last, Robert L

    2016-03-01

    Glandular trichomes of cultivated tomato (Solanum lycopersicum) and many other species throughout the Solanaceae produce and secrete mixtures of sugar esters (acylsugars) on the plant aerial surfaces. In wild and cultivated tomato, these metabolites consist of a sugar backbone, typically glucose or sucrose, and two to five acyl chains esterified to various positions on the sugar core. The aliphatic acyl chains vary in length and branching and are transferred to the sugar by a series of reactions catalyzed by acylsugar acyltransferases. A phenotypic screen of a set of S. lycopersicum M82 × Solanum pennellii LA0716 introgression lines identified a dominant genetic locus on chromosome 5 from the wild relative that affected total acylsugar levels. Genetic mapping revealed that the reduction in acylsugar levels was consistent with the presence and increased expression of two S. pennellii genes (Sopen05g030120 and Sopen05g030130) encoding putative carboxylesterase enzymes of the α/β-hydrolase superfamily. These two enzymes, named ACYLSUGAR ACYLHYDROLASE1 (ASH1) and ASH2, were shown to remove acyl chains from specific positions of certain types of acylsugars in vitro. A survey of related genes in M82 and LA0716 identified another trichome-expressed ASH gene on chromosome 9 (M82, Solyc09g075710; LA0716, Sopen09g030520) encoding a protein with similar activity. Characterization of the in vitro activities of the SpASH enzymes showed reduced activities with acylsugars produced by LA0716, presumably contributing to the high-level production of acylsugars in the presence of highly expressed SpASH genes. PMID:26811191

  3. Trichomes control flower bud shape by linking together young petals.

    Science.gov (United States)

    Tan, Jiafu; Walford, Sally-Anne; Dennis, Elizabeth S; Llewellyn, Danny

    2016-01-01

    Trichomes are widespread in plants and develop from surface cells on different tissues(1). They have many forms and functions, from defensive spines to physical barriers that trap layers of air to insulate against desiccation, but there is growing evidence that trichomes can also have developmental roles in regulating flower structure(2,3). We report here that the trichomes on petals of cotton, Gossypium hirsutum L., are essential for correct flower bud shape through a mechanical entanglement of the trichomes on adjacent petals that anchor the edges to counter the opposing force generated by asymmetric expansion of overlapping petals. Silencing a master regulator of petal trichomes, GhMYB-MIXTA-Like10 (GhMYBML10), by RNA interference (RNAi) suppressed petal trichome growth and resulted in flower buds forming into abnormal corkscrew shapes that exposed developing anthers and stigmas to desiccation damage. Artificially gluing petal edges together could partially restore correct bud shape and fertility. Such petal 'Velcro' is present in other Malvaceae and perhaps more broadly in other plant families, although it is not ubiquitous. This mechanism for physical association between separate organs to regulate flower shape and function is different from the usual organ shape control(4) exerted through cell-to-cell communication and differential cell expansion within floral tissues(5,6). PMID:27322517

  4. Characterization of two genes for the biosynthesis of abietane-type diterpenes in rosemary (Rosmarinus officinalis) glandular trichomes

    NARCIS (Netherlands)

    Brückner, K.; Bozic, D.; Manzano, D.; Papaefthimiou, D.; Pateraki, I.; Scheler, U.; Ferrer, A.; Vos, de R.C.H.; Kanellis, A.K.; Tissier, A.

    2014-01-01

    Rosemary (Rosmarinus officinalis) produces the phenolic diterpenes carnosic acid and carnosol, which, in addition to their general antioxidant activities, have recently been suggested as potential ingredients for the prevention and treatment of neurodegenerative diseases. Little is known about the b

  5. Probing essential oil biosynthesis and secretion by functional evaluation of expressed sequence tags from mint glandular trichomes

    OpenAIRE

    Lange, B. Markus; Wildung, Mark R.; Stauber, Einar J.; Sanchez, Christopher; Pouchnik, Derek; Croteau, Rodney

    2000-01-01

    Functional genomics approaches, which use combined computational and expression-based analyses of large amounts of sequence information, are emerging as powerful tools to accelerate the comprehensive understanding of cellular metabolism in specialized tissues and whole organisms. As part of an ongoing effort to identify genes of essential oil (monoterpene) biosynthesis, we have obtained sequence information from 1,316 randomly selected cDNA clones, or expressed sequence tags (ESTs), from a pe...

  6. Periareolar Extra-Glandular Breast Augmentation

    OpenAIRE

    Mohmand, Muhammad Humayun; Ahmad, Muhammad

    2013-01-01

    BACKGROUND Breast augmentation is the most frequent procedure performed according to the 2009 Quick Facts report of the American Society of Plastic Surgeons. This study presents the periareolar extra-glandular breast augmentation. METHODS From 2004 to 2010 among 32 female patients, peri-areolar incision was performed for breast augmentation. Dissection was performed in subcutaneous plane towards the inferior pole to reach the inframammary fold and was continued in the upwards direction in the...

  7. Inflammatory and glandular skin disease in pregnancy.

    Science.gov (United States)

    Yang, Catherine S; Teeple, Mary; Muglia, Jennie; Robinson-Bostom, Leslie

    2016-01-01

    A switch from cell-mediated to humoral immunity (helper T 1 [Th1] to helper T 2 [Th2] shift) during gestation plays a key role in placental immune tolerance. As a result, skin diseases that are Th2 mediated often worsen, whereas skin diseases that are Th1 mediated often improve during gestation. Also, due to fluctuations in glandular activity, skin diseases involving sebaceous and eccrine glands may flare, whereas those involving apocrine glands may improve during pregnancy. Despite these trends, inflammatory and glandular skin diseases do not always follow the predicted pattern, and courses are often diverse. We review the gestational course of inflammatory skin diseases, such as atopic dermatitis (atopic eruption of pregnancy), psoriasis, impetigo herpetiformis, urticaria, erythema annulare centrifugum, pityriasis rosea, sarcoidosis, Sweet syndrome, and erythema nodosum, as well as glandular skin diseases, including acne vulgaris, acne rosacea, perioral dermatitis, hidradenitis suppurativa, Fox-Fordyce disease, hyperhidrosis, and miliaria. For each of these diseases, we discuss the pathogenesis, clinical presentation, and management with special consideration for maternal and fetal safety. PMID:27265071

  8. Mean glandular dose for different angles of the X-ray tube using different glandularity phantoms

    International Nuclear Information System (INIS)

    Digital breast tomosynthesis (DBT) is a three-dimensional radiographic technique that is beginning to be used as part of an imaging diagnostic program in some of Brazilian clinical practices. Studies are needed to evaluate the performance and to determine the radiation dose of patients that are undergoing this new procedure. The aim of this work is to present results of the mean glandular dose (DG) for different angles of the X-ray tube using a computed radiography (CR) mammography unit and different glandularity standard breast phantoms. DG values were derived from measurements of the incident air kerma (Ki) and tabulated conversion coefficients that are dependent on the half-value layer (HVL) of the X-ray spectrum. Irradiations were done in a 3000 Nova model Siemens MAMMOMAT mammography unit with the X-ray tube angle ranging from −30° to 30°. The protocol with 28 kV was used for Mo/Mo combination. The distance between focus and the 90×5–6 M model Radcal ionization chamber was 60.5 cm and the tube loading (PIt) used was 50 mA s. Exposures were done for DG determination using the semi-automatic exposure control mode and the 45 mm Computerized Imaging Reference Systems, Inc phantoms which approximately simulate a standard breast with glandularities of 0, 30, 50, 70 and 100%. DG values ranged from 1.3±0.1 to 7.6±0.7 mGy. The results are in according to the reference level of 3 mGy established by the International Basic Safety Standards (BSS115) to breast with 45 mm of thickness, 50% of glandularity and for the X-ray tube positioned in 0°. The results showed that DG increases with the glandularity and with the rotation of the X-ray tube. This work contributes to begin in Brazil the dosimetry in DBT equipments using different protocols and target/filter combinations. - Highlights: ► Glandularity phantoms and a computed radiography mammography unit were used. ► Results were calculated from the incident air kerma and conversion coefficients. ► They are in

  9. Characteristics of the secretory structures in the flowers of Rosa rugosa Thunb.

    Directory of Open Access Journals (Sweden)

    Aneta Sulborska

    2014-12-01

    Full Text Available Due to the presence of secondary metabolites exhibiting pharmacological activity, the flowers of Rosa rugosa Thunb. have found application in traditional and folk medicine. The essential oil obtained from them is also considered to be a phytoncide. The morphological and anatomical characters of glandular trichomes located on the sepals of R. rugosa were studied by light and scanning electron microscopy. Using histochemical tests, the type of secretion produced in the trichomes was determined and its contents were compared with the secretion produced by the papillae on the petals. It was found that multicellular glandular trichomes, having the features of colleters, and non-glandular trichomes were located on the abaxial epidermis, while only non-glandular trichomes were situated on the adaxial epidermis. The stalk cells of the glandular trichomes are arranged in multiple rows, whereas the epidermal cells of the head are arranged radially. The capitate trichomes were classified into two types: short and long trichomes. The largest density of glandular trichomes was recorded in the basal abaxial epidermis and in the middle part of the sepals. During the initial stages of bud development, the glandular hairs were green colored, whereas in the next development stages they changed the color to red. The histochemical tests used allowed us to find that the trichomes on the sepals and the papille on the petals produced lipid substances, polyphenols, tannins, and flavonoids. Sesquiterpenes were found only in the secretion of the glandular hairs on the sepals.

  10. Clade-specific positive selection on a developmental gene: BRANCHLESS TRICHOME and the evolution of stellate trichomes in Physaria (Brassicaceae).

    Science.gov (United States)

    Mazie, Abigail R; Baum, David A

    2016-07-01

    Positive selection is known to drive the evolution of genes involved in evolutionary arms races, but what role does it play in the evolution of genes involved in developmental processes? We used the single-celled epidermal trichomes of Brassicaceae as a model to uncover the molecular evolutionary processes that contributed to the transition from dendritic trichomes, as seen in most species of Brassicaceae, to the distinctive stellate trichomes of the genus Physaria. We explored the role of positive selection on the evolution of BRANCHLESS TRICHOME (BLT), a candidate gene for changes in trichome branching pattern. Maximum likelihood models of codon evolution point to a shift in selective pressure affecting the evolution of BLT across the entire Physaria clade, and we found strong evidence that positive selection has acted on a subset of Physaria BLT codons. Almost all of the 10 codon sites with the highest probability of having evolved under positive selection are clustered in a predicted coiled-coil domain, pointing to changes in protein-protein interactions. Thus, our findings suggest that selection acted on BLT to modify its interactions with other proteins. The fact that positive selection occurred throughout the radiation of Physaria could reflect selection to stabilize development in response to an abrupt switch from the dendritic form to the stellate form, divergent selection for diversification of the stellate form, or both. These results point to the need for evolutionary developmental studies of BLT and its interacting proteins in Physaria. PMID:27015897

  11. SIAMESE, a gene controlling the endoreduplication cell cycle in Arabidopsis thaliana trichomes.

    Science.gov (United States)

    Walker, J D; Oppenheimer, D G; Concienne, J; Larkin, J C

    2000-09-01

    Cell differentiation is generally tightly coordinated with the cell cycle, typically resulting in a nondividing cell with a unique differentiated morphology. The unicellular trichomes of Arabidopsis are a well-established model for the study of plant cell differentiation. Here, we describe a new genetic locus, SIAMESE (SIM), required for coordinating cell division and cell differentiation during the development of Arabidopsis trichomes (epidermal hairs). A recessive mutation in the sim locus on chromosome 5 results in clusters of adjacent trichomes that appeared to be morphologically identical 'twins'. Upon closer inspection, the sim mutant was found to produce multicellular trichomes in contrast to the unicellular trichomes produced by wild-type (WT) plants. Mutant trichomes consisting of up to 15 cells have been observed. Scanning electron microscopy of developing sim trichomes suggests that the cell divisions occur very early in the development of mutant trichomes. WT trichome nuclei continue to replicate their DNA after mitosis and cytokinesis have ceased, and as a consequence have a DNA content much greater than 2C. This phenomenon is known as endoreduplication. Individual nuclei of sim trichomes have a reduced level of endoreduplication relative to WT trichome nuclei. Endoreduplication is also reduced in dark-grown sim hypocotyls relative to WT, but not in light-grown hypocotyls. Double mutants of sim with either of two other mutants affecting endoreduplication, triptychon (try) and glabra3 (gl3) are consistent with a function for SIM in endoreduplication. SIM may function as a repressor of mitosis in the endoreduplication cell cycle. Additionally, the relatively normal morphology of multicellular sim trichomes indicates that trichome morphogenesis can occur relatively normally even when the trichome precursor cell continues to divide. The sim mutant phenotype also has implications for the evolution of multicellular trichomes. PMID:10952891

  12. Glandular odontogenic cyst: A diagnostic dilemma.

    Science.gov (United States)

    Shah, Amisha A; Sangle, Amit; Bussari, Smita; Koshy, Ajit V

    2016-01-01

    Glandular odontogenic cyst (GOC) is a rare and uncommon jaw bone cyst of odontogenic origin described in 1987 by Gardener et al. as a distinct entity. It is a cyst having an unpredictable, potentially aggressive behavior, and has the propensity to grow in large size with relatively high recurrence rate. It poses a diagnostic challenge as it can be clinically and histopathologically confused with lateral periodontal cyst, botryoid odontogenic cyst, radicular and residual cysts with mucous metaplasia, and low-grade mucoepidermoid carcinoma. The present case report describes GOC in both male and female patients with intra-oral swelling following extraction of 36 and 46, respectively. Careful histopathological examination is needed to diagnose GOC, and a careful long-term follow-up is advocated. PMID:27134453

  13. Glandular odontogenic cyst mimicking central mucoepidermoid carcinoma

    Directory of Open Access Journals (Sweden)

    Prabhu Sudeendra

    2010-01-01

    Full Text Available Glandular odontogenic cyst (GOC is a rare developmental cyst of the jaws. The most common site of occurrence is the anterior mandible, and it is most commonly seen in middle-aged people. It is a destructive lesion with a high rate of recurrence. A predilection for men is observed. Clinical and radiographic findings are not specific, and it can mimic as any other destructive lesion of the jaw. The histopathological features of GOC and those of low-grade central mucoepidermoid carcinoma (MEC are similar. Often, they are misdiagnosed as MEC. We present a case of GOC in the posterior maxilla, which is a rare site. The similarities and differences between GOC and central MEC are also discussed.

  14. Glandular odontogenic cyst: A case report

    International Nuclear Information System (INIS)

    Glandular odontogenic cysts (GOCs) are rare intrabony solitary or multiloculated cysts of odontogenic origin. The importance of GOCs lies in the fact that they exhibit a propensity for recurrence similar to keratocystic odontogenic tumors and that they may be confused microscopically with central mucoepidermoid carcinoma. Thus, the oral and maxillofacial radiologists play an important role in definitive diagnosis of GOC based on distinctive cases; though they are rare. In large part, this is due to the GOC's complex and frequently non-specific histopathology. This report describes a case of GOC occurrence in the posterior mandibular ramus region in a 17-year-old female, which is a rare combination of site, age, and gender for occurrence.

  15. Glandular odontogenic cyst: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Tambawaia, Shahnaz S.; Karjodkar, Freny R.; Yadav, Archana; Sansare, Kaustubh; Sontakke, Subodh [Nair Hospital Dental College, Mumbai (India)

    2014-03-15

    Glandular odontogenic cysts (GOCs) are rare intrabony solitary or multiloculated cysts of odontogenic origin. The importance of GOCs lies in the fact that they exhibit a propensity for recurrence similar to keratocystic odontogenic tumors and that they may be confused microscopically with central mucoepidermoid carcinoma. Thus, the oral and maxillofacial radiologists play an important role in definitive diagnosis of GOC based on distinctive cases; though they are rare. In large part, this is due to the GOC's complex and frequently non-specific histopathology. This report describes a case of GOC occurrence in the posterior mandibular ramus region in a 17-year-old female, which is a rare combination of site, age, and gender for occurrence.

  16. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-12-15

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  17. A huge glandular odontogenic cyst occurring at posterior mandible

    International Nuclear Information System (INIS)

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  18. Primary glandular melanoma of male breast with nodal metastasis

    OpenAIRE

    Jayabal Pandiaraja

    2016-01-01

    Malignant melanoma is a malignancy that develops from melanocytes. Breast is an uncommon site for malignant melanoma. Melanoma of the breast occurs in various situations such as primary melanoma of breast skin, metastatic melanoma of breast, in-transit metastasis to the breast, and primary glandular breast melanoma. Most of the melanoma breast either cutaneous melanoma or metastatic melanoma. Primary glandular melanoma of male breast with nodal involvement is rarely reported compared to prima...

  19. Variation in vegetative growth and trichomes in Cannabis sativa L. (Marihuana) in response to enviromental pollution

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, G.K.; Mann, S.K.

    1984-07-01

    Four populations of Cannabis sativa L. (marihuana) growing in their native habitat and exposed to different levels of environmental pollution were studied for several leaf morphology and leaf trichome features. Leaf length, petiole length, length and width of central leaflet, and the number of teeth on leaf margin decreased with increase in pollution. Trichome length and trichome density values were found to be higher in populations exposed to higher levels of environmental pollution.

  20. Average glandular dose conversion coefficients for segmented breast voxel models

    International Nuclear Information System (INIS)

    For 8 voxel models of a compressed breast (4-7 cm thickness and two orientations for each thickness) and 14 radiation qualities commonly used in mammography (HVL 0.28-0.50 mm Al), tissue dose conversion coefficients were calculated for a focus-to-film distance of 60 cm using Monte Carlo methods. The voxel models were segmented from a high-resolution (slice thickness of 1 mm) computed tomography data set of an ablated breast specimen fixated while being compressed. The contents of glandular tissues amounted to 2.6%, and were asymmetrically distributed with regard to the midplane of the model. The calculated tissue dose conversion coefficients were compared with the recent literature values. These earlier tissue dose conversion coefficients were also calculated using Monte Carlo methods and breast models of various thickness, but these consist of homogeneous mixtures of glandular and adipose tissues embedded in 5 mm pure adipose tissue both at the entrance and exit sides. The results show that the new glandular tissue dose conversion coefficients agree well with the literature values for those cases where the glandular tissue is predominantly concentrated in the upper part of the model. In the opposite case, they were lower by up to 40%. These findings reveal a basic problem in patient dosimetry for mammography: glandular dose is not only governed by the average breast composition, which could be derived from the breast thickness, but also by the local distribution of glandular tissue within the breast, which is not known. (authors)

  1. Maize leaf trichomes represent an entry point of infection for Fusarium species.

    Science.gov (United States)

    Nguyen, Thi Thanh Xuan; Dehne, Heinz-Wilhelm; Steiner, Ulrike

    2016-08-01

    Fifteen day old maize seedlings were inoculated with Fusarium graminearum, Fusarium proliferatum, and Fusarium verticillioides. More than 90 % F. proliferatum and F. verticillioides conidia and 50 % of F. graminearum formed one germ tube whereas the other 50 % of F. graminearum conidia formed two to three germ tubes. The germ tubes of F. graminearum conidia were longer than those of F. proliferatum and F. verticillioides. The three species of Fusarium infected bi-cellular trichomes by adhering and growing along the trichomes or by attaching to the cap cell of the trichomes 48 h after inoculation. Hyphae penetrated into the trichomes at the base, the side or at the top of the cap cells. The hyphae colonized the cap cells and then spread to base cells. Prickle trichomes were infected 72 h after inoculation. The hyphae either wrapped around prickle trichomes or formed a mass of hyphae around the top of prickle trichomes or formed appressorium. Macro trichomes were infected by F. graminearum 7 d after inoculation. Following penetration, the fungus spread to adjacent epidermal cells and to the subcuticle. This investigation provides the first assessment of F. graminearum, F. proliferatum, and F. verticillioides infection via trichomes of maize leaves. PMID:27521623

  2. Evaluation of exposure in mammography: limitations of average glandular dose and proposal of a new quantity

    International Nuclear Information System (INIS)

    The radiation risk in mammography is traditionally evaluated using the average glandular dose. This quantity for the average breast has proven to be useful for population statistics and to compare exposure techniques and systems. However it is not indicating the individual radiation risk based on the individual glandular amount and distribution. Simulations of exposures were performed for six appropriate virtual phantoms with varying glandular amount and distribution. The individualised average glandular dose (iAGD), i.e. the individual glandular absorbed energy divided by the mass of the gland, and the glandular imparted energy (GIE), i.e. the glandular absorbed energy, were computed. Both quantities were evaluated for their capability to take into account the glandular amount and distribution. As expected, the results have demonstrated that iAGD reflects only the distribution, while GIE reflects both the glandular amount and distribution. Therefore GIE is a good candidate for individual radiation risk assessment. (authors)

  3. Evaluation of glandular dose in conventional and digital mammography systems

    International Nuclear Information System (INIS)

    A survey was conducted to estimate the average glandular dose (Dg) for patients undergoing mammography and to report the distribution of incident air kerma (Ki), patient age, compressed breast thickness and glandular tissue content. From 1183 cranio caudal mammograms clinical data were collected and doses were measured. The survey data included mammograms from six mammography equipment: two screen/film units (SFM), two computed radiography units (CR) and two full-field digital (DR). Mean value for patient age and compressed breast thickness were 57 +-12 y and 5.4 +-1.4 cm, respectively. To investigate the importance of technical characteristics of three different mammography systems and breast glandularity, Ki and Dg were measured for individual breast of 392 patients from the original sample with compressed breast thickness in the range of 5.5 cm to 6.5 cm using tissue-equivalent phantoms of different glandularities manufactured in this study to mimic both the attenuation and the density of breast tissues. Mean Ki value was 10.0 +-3.6 mGy for SFM systems, 12.0 +-3.6 mGy for CR systems and 4.9 +-1.3 mGy for DR systems. Mean Dg value was 1.4 +-0.5 mGy for S/F systems, 1.7 +-0.5 mGy for CR systems and 0.9 +-0.2 mGy for D R systems. Statistical analysis for differences in mean values of Ki and Dg between mammography systems showed significant effect of their technical characteristics (p i and Dg, it was observed statistically significant differences between the group of patients with 0 to 50% glandularity and the group of patients with 50 to 100% glandularity. (author)

  4. Average glandular dose in patients submitted to mammographic examinations

    International Nuclear Information System (INIS)

    Doses in mammography should be maintained as low as possible without reducing the high image quality needed to the early detection of the breast cancer. As the breast is composed of tissues with very soft composition and densities, it increases the difficulty to detect small changes in the normal anatomical structures that may be associated with breast cancer. To achieve the standards of resolution and contrast for mammography, the quality and intensity of the X-ray beam, the breast positioning and compression, the film screen system, and the film processing must be in optimal operational conditions. This study intended to evaluate the mean glandular dose of patients undergoing routine exams in one mammography unit. Patient image analyses were done by a radiologist doctor who took into account 10 evaluation criteria for each CC and MLO incidences. For estimating each patient glandular dose the radiographic technique parameters (kV and mAs) and the thickness of the compressed breast were recorded. European image quality criteria were adopted by the radiologist doctor to accept the image for diagnostic purpose. For breast densities of 50% adipose and 50% glandular tissues the incident air-kerma was measured and the glandular dose calculated considering the x-ray output during the exam. In the study of 50 patients the mean glandular dose varied from 0.90 to 3.27 mGy with a mean value of 1.98 mGy for CC incidences. For MLO incidences the mean glandular doses ranged from 0.97 to 3.98 mGy and a mean value of 2.60 mGy. (author)

  5. Giant cardiac myxoma with malignant transformed glandular structures

    Energy Technology Data Exchange (ETDEWEB)

    Eckhardt, Boris P.; Stuckmann, Gerd; Zollikofer, Christoph L. [Institute of Radiology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Dommann-Scherrer, Corina C. [Insitute of Pathology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Wentz, Klaus U. [Institute of Radiology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Medical Faculty, University of Witten/Herdecke, Alfred-Herrhausen-Strasse 50, 58448 Witten (Germany)

    2003-09-01

    A case of a right-sided giant cardiac myxoma with malignant transformation of glandular structures causing systemic metastases is described. Plain chest radiography and computed tomography localized the tumor within the heart. Exact depiction of the origin of the tumor using subtracted 2D-projection MR angiography is documented. Radiologic findings and differential diagnosis of this unique tumor are discussed. (orig.)

  6. From capital to capital

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    HOW easy it is for one who lives in Beijing, capital of the country, to have the impression that all things significant happen there! This is to forget how there are now many provincial capitals in China, that are rapidly modernizing. In order to achieve such modernization, these cities, like

  7. Herbivore handling of a plant's trichome: the case of Heliconius charithonia (L.) (Lepidoptera: Nymphalidae) and Passiflora lobata (Killip) Hutch. (Passifloraceae)

    International Nuclear Information System (INIS)

    Trichomes reduce herbivore attack on plants by physically and/or chemically inhibiting movement or other activities. Despite evidence that herbivores are negatively affected by trichomes there also reports of insect counter-adaptations that circumvent the plant's defense. This paper reports on a study that investigated the likely mechanisms employed by larvae of the nymphalid butterfly, Heliconius charithonia (L.), that allow it to feed on a host that is presumably protected by hooked trichomes (Passiflora lobata (Killip) Hutch). Evidence were gathered using data from direct observations of larval movement and behavior, faeces analysis, scanning electron microscopy of plant surface and experimental analysis of larval movement on plants with and without trichomes (manually removed). The latter involved a comparison with a non specialist congener, Heliconius pachinus Salvin. Observations showed that H. charithonia larvae are capable of freeing themselves from entrapment on trichome tips by physical force. Moreover, wandering larvae lay silk mats on the trichomes and remove their tips by biting. In fact, trichome tips were found in the faeces. Experimental removal of trichomes aided in the movement of the non specialist but had no noticeable effect on the specialist larvae. These results support the suggestion that trichomes are capable of deterring a non specialist herbivore (H. pachinus). The precise mechanisms that allow the success of H. charithonia are not known, but I suggest that a blend of behavioral as well as physical resistance mechanisms is involved. Future studies should ascertain whether larval integument provides physical resistance to trichomes. (author)

  8. The taxonomic significance of trichome type and distribution in Melolobium (Fabaceae

    Directory of Open Access Journals (Sweden)

    A. Moteetee

    2002-12-01

    Full Text Available All species of Melolobium Eckl. & Zeyh. were examined for epidermal features and particularly the glands which are a distinctive feature amongst the southern African Genisteae. For comparative purposes, three species of Argxrolobium Eckl.& Zeyh.. all  five species of Dichilus DC. and five species of Polhillia C.H.Stirt. were also examined for trichome type and distribution. Three trichome types are recognized in Melolobium. Trichome type and distribution provide an important insight into taxonomic relations at species level in Melolobium and sometimes even allow a distinction between regional forms. The distribution of glands (sessile and stalked is of considerable diagnostic value in identifying  species  of Melolobium. A key to all the species of the genus based mainly on type and distribution of trichomes. is presented.

  9. A novel texture descriptor for detection of glandular structures in colon histology images

    Science.gov (United States)

    Sirinukunwattana, Korsuk; Snead, David R.; Rajpoot, Nasir M.

    2015-03-01

    The first step prior to most analyses on most histopathology images is the detection of area of interest. In this work, we present a superpixel-based approach for glandular structure detection in colon histology images. An image is first segmented into superpixels with the constraint on the presence of glandular boundaries. Texture and color information is then extracted from each superpixel to calculate the probability of that superpixel belonging to glandular regions, resulting in a glandular probability map. In addition, we present a novel texture descriptor derived from a region covariance matrix of scattering coefficients. Our approach shows encouraging results for the detection of glandular structures in colon tissue samples.

  10. Intellectual Capital.

    Science.gov (United States)

    Snyder, Herbert W.; Pierce, Jennifer Burek

    2002-01-01

    This review focuses on intellectual capital and its relationship to information professionals. Discusses asset recognition; national practices and the acceptance of intellectual capital; definitions of intellectual capital; measuring intellectual capital, including multiple and single variable measures; managing intellectual capital; and knowledge…

  11. Molecular basis of natural variation and environmental control of trichome patterning

    OpenAIRE

    Hauser, Marie-Theres

    2014-01-01

    Trichomes are differentiated epidermal cells on above ground organs of nearly all land plants. They play important protective roles as structural defenses upon biotic attacks such as herbivory, oviposition and fungal infections, and against abiotic stressors such as drought, heat, freezing, excess of light, and UV radiation. The pattern and density of trichomes is highly variable within natural population suggesting tradeoffs between traits positively affecting fitness such as resistance and ...

  12. Distribution of DMT 1 within the human glandular system

    OpenAIRE

    Koch, R.O.; H. Zoller; Theurl, I.; Obrist, P.; Egg, G.; Strohmayer, W.; Vogel, W.; Weiss, G. (Günter)

    2003-01-01

    Background & Aims: DMT1 is a transmembrane protein which transports the divalent metal ions Fe2+, Zn2+, Cu2+ and Mn2+. Although DMT1 has been functionally linked to duodenal absorption and cellular utilisation of iron hardly anything is known about its distribution and potential role within the human glandular system. Methods: Two polyclonal antibodies were raised to study the expression of DMT1 in tissues obtained from human corpus by the means of immunocy...

  13. Detecting uterine glandular lesions: Role of cervical cytology

    Science.gov (United States)

    Bansal, Baneet; Gupta, Parikshaa; Gupta, Nalini; Rajwanshi, Arvind; Suri, Vanita

    2016-01-01

    Background: The sensitivity of cervical cytology for detection of glandular lesions is reported to be low. We conducted this study to assess the diagnostic accuracy of cervical Papanicolaou (Pap) smears for uterine glandular lesions and to compare the diagnostic utility of conventional and liquid-based cytology (LBC) smears for glandular lesions. Materials and Methods: Archived histopathology records of all cases reported as endocervical and endometrial adenocarcinoma in the study period were identified and the available corresponding Pap smears (in preceding 1 year) were retrieved. In addition, the Pap smears reported as glandular cell abnormalities (GCA) during the same study period were retrieved. The overall prevalence of GCA, sensitivity, and specificity of Pap smears for the detection of GCA was calculated. The diagnostic accuracy of conventional and LBC smears for the diagnosis of GCA was also compared. Results: The prevalence of GCA in our study was 0.32%. The overall specificity of Pap smears for the diagnosis of GCA was 60.8%, this was not significantly different between conventional and LBC smears (P = 0.4). The overall sensitivity of Pap smears for the detection of GCA was 41.8%; LBC smears had significantly better sensitivity as compared to conventional smears for the detection of endometrial as compared to endocervical adenocarcinoma (P Pap smears is low. The specificity of Pap smears, for diagnosis of GCA, was found to be moderate. However, the overall sensitivity of Pap smears for the detection of GCA was low, though better for LBC as compared to conventional smears. PMID:27014363

  14. Erotic Capital

    OpenAIRE

    Jensen, Natalie Madeleine; Jensen, Benjamin; Engstrøm, Emma; Maas, Jannik; Majchrzak, Izabela

    2016-01-01

    This project “Erotic Capital” concerns the topic and theory of Erotic Capital, coined by Catherine Hakim. The idea of Erotic Capital derives from Pierre Bourdieu’s theory of Personal Capitals – in this, Erotic Capital is discussed as an additional Personal Capital. In connection to the investigation of the theory Erotic Capital, certain theories of Feminism, Masculinity, Femininity, Gender and Cultural Differences are explored and examined. This is done in order to study how these theories...

  15. A COMPARATIVE NUMERIC ANALYSIS OF THE SECRETORY TRICHOMES BELONGING TO THE FOLIAR LIMB IN SOME DROSERA SPECIES

    OpenAIRE

    IRINA STĂNESCU; GABRIELA VASILE

    2008-01-01

    The paper is focused on a comparative numeric analysis of the secretory pedicelate (tentacular) trichomes of the upper epidermis of the leaf in 16 Drosera species and of the sessile secretory trichomes belonging to both upper and lower epidermis in the same species. The bigger is the number of the secretory trichomes, in both epidermises, the more efficient is the plant in capturing and retaining different organisms. This way, the carnivorous plants can completely benefit by the nutritive com...

  16. Calcium promotes cadmium elimination as vaterite grains by tobacco trichomes

    Science.gov (United States)

    Isaure, Marie-Pierre; Sarret, Géraldine; Harada, Emiko; Choi, Yong-Eui; Marcus, Matthew A.; Fakra, Sirine C.; Geoffroy, Nicolas; Pairis, Sébastien; Susini, Jean; Clemens, Stephan; Manceau, Alain

    2010-10-01

    In tobacco plants, elimination of Zn and Cd via the production of Ca-containing grains at the top of leaf hairs, called trichomes, is a potent detoxification mechanism. This study examines how Cd is incorporated in these biominerals, and how calcium growth supplement modifies their nature. Scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX), microfocused X-ray diffraction (μ-XRD), and microfocused X-ray absorption near edge structure (μ-XANES) spectroscopy were used to image the morphology of the grains, identify the crystallized mineral phases, and speciate Cd, respectively. The mineralogy of the grains and chemical form of Cd varied with the amount of Ca. When tobacco plants were grown in a nutrient solution containing 25 μM Cd and low Ca supplement (Ca/Cd = 11 mol ratio), most of the grains were oblong-shaped and low-Cd-substituted calcite. When exposed to the same amount of Cd and high Ca supplement (Ca/Cd = 131 mol ratio), grains were more abundant and diverse in compositions, and in total more Cd was eliminated. Most grains in the high Ca/Cd experiment were round-shaped and composed predominantly of Cd-substituted vaterite, a usually metastable calcium carbonate polymorph, and subordinate calcite. Calcium oxalate and a Ca amorphous phase were detected occasionally in the two treatments, but were devoid of Cd. The biomineralization of cadmium and implications of results for Cd exposure of smokers and phytoremediation are discussed.

  17. Metabolic engineering of terpene biosynthesis in plants using a trichome-specific transcription factor MsYABBY5 from spearmint (Mentha spicata).

    Science.gov (United States)

    Wang, Qian; Reddy, Vaishnavi Amarr; Panicker, Deepa; Mao, Hui-Zhu; Kumar, Nadimuthu; Rajan, Chakravarthy; Venkatesh, Prasanna Nori; Chua, Nam-Hai; Sarojam, Rajani

    2016-07-01

    In many aromatic plants including spearmint (Mentha spicata), the sites of secondary metabolite production are tiny specialized structures called peltate glandular trichomes (PGT). Having high commercial values, these secondary metabolites are exploited largely as flavours, fragrances and pharmaceuticals. But, knowledge about transcription factors (TFs) that regulate secondary metabolism in PGT remains elusive. Understanding the role of TFs in secondary metabolism pathway will aid in metabolic engineering for increased yield of secondary metabolites and also the development of new production techniques for valuable metabolites. Here, we isolated and functionally characterized a novel MsYABBY5 gene that is preferentially expressed in PGT of spearmint. We generated transgenic plants in which MsYABBY5 was either overexpressed or silenced using RNA interference (RNAi). Analysis of the transgenic lines showed that the reduced expression of MsYABBY5 led to increased levels of terpenes and that overexpression decreased terpene levels. Additionally, ectopic expression of MsYABBY5 in Ocimum basilicum and Nicotiana sylvestris decreased secondary metabolite production in them, suggesting that the encoded transcription factor is probably a repressor of secondary metabolism. PMID:26842602

  18. From shavenbaby to the naked valley: trichome formation as a model for evolutionary developmental biology.

    Science.gov (United States)

    Arif, Saad; Kittelmann, Sebastian; McGregor, Alistair P

    2015-01-01

    Microtrichia or trichomes are non-sensory actin protrusions produced by the epidermal cells of many insects. Studies of trichome formation in Drosophila have over the last 30 years provided key insights towards our understanding of gene regulation, gene regulatory networks (GRNs), development, the genotype to phenotype map, and the evolution of these processes. Here we review classic studies that have used trichome formation as a model to shed light on Drosophila development as well as recent research on the architecture of the GRN underlying trichome formation. This includes the findings that both small peptides and microRNAs play important roles in the regulation and evolution of this network. In addition, we review research on the evolution of trichome patterns that has provided novel insights into the function and architecture of cis-regulatory modules, and into the genetic basis of morphological change. We conclude that further research on these apparently simple and often functionally enigmatic structures will continue to provide new and important knowledge about development and evolution. PMID:25627718

  19. Glandular odontogenic cyst: Report of an unusual bilateral occurrence

    OpenAIRE

    Vikram S Amberkar; Abhishek Jahagirdar; B R Ahmed Mujib

    2011-01-01

    Glandular odontogenic cyst (GOC) is a recently recognized rare developmental odontogenic cyst having an aggressive behavior and accounting for 0.012% to 1.3% of all jaw cysts. GOC usually presents as a painless, slow-growing swelling that tends to affect the anterior part of the jaws. It chiefly occurs in the fourth and fifth decades of life and presents as an expansion of jaws with or without pain or paresthesia. Aggressive nature of the lesion has been reported, as supported by the fact tha...

  20. Botulinum toxin for treatment of glandular hypersecretory disorders.

    LENUS (Irish Health Repository)

    Laing, T A

    2012-02-03

    SUMMARY: The use of botulinum toxin to treat disorders of the salivary glands is increasing in popularity in recent years. Recent reports of the use of botulinum toxin in glandular hypersecretion suggest overall favourable results with minimal side-effects. However, few randomised clinical trials means that data are limited with respect to candidate suitability, treatment dosages, frequency and duration of treatment. We report a selection of such cases from our own department managed with botulinum toxin and review the current data on use of the toxin to treat salivary gland disorders such as Frey\\'s syndrome, excessive salivation (sialorrhoea), focal and general hyperhidrosis, excessive lacrimation and chronic rhinitis.

  1. New method for generating breast models featuring glandular tissue spatial distribution

    Science.gov (United States)

    Paixão, L.; Oliveira, B. B.; Oliveira, M. A.; Teixeira, M. H. A.; Fonseca, T. C. F.; Nogueira, M. S.

    2016-02-01

    Mammography is the main radiographic technique used for breast imaging. A major concern with mammographic imaging is the risk of radiation-induced breast cancer due to the high sensitivity of breast tissue. The mean glandular dose (DG) is the dosimetric quantity widely accepted to characterize the risk of radiation induced cancer. Previous studies have concluded that DG depends not only on the breast glandular content but also on the spatial distribution of glandular tissue within the breast. In this work, a new method for generating computational breast models featuring skin composition and glandular tissue distribution from patients undergoing digital mammography is proposed. Such models allow a more accurate way of calculating individualized breast glandular doses taking into consideration the glandular tissue fraction. Sixteen breast models of four patients with different glandularity breasts were simulated and the results were compared with those obtained from recommended DG conversion factors. The results show that the internationally recommended conversion factors may be overestimating the mean glandular dose to less dense breasts and underestimating the mean glandular dose for denser breasts. The methodology described in this work constitutes a powerful tool for breast dosimetry, especially for risk studies.

  2. Glandular areas associated with the male genitalia in Triatoma rubrofasciata (Triatominae, Reduviidae, Hemiptera and other Reduviidae

    Directory of Open Access Journals (Sweden)

    Christiane Weirauch

    2003-09-01

    Full Text Available In this paper, glandular areas associated with the phallus in Triatoma rubrofasciata are described and illustrated for the first time. The glandular areas lie in the membrane surrounding the articulatory apparatus. In order to unambiguously define the locality of the respective glandular areas, some features of the pygophore-phallus connection are redescribed. A possible functional context of the gland secretions is discussed. A preliminary study of several other Reduviidae implies that the described glandular areas occur in a wider range of taxa in this group.

  3. Comparison of five major trichome regulatory genes in Brassica villosa with orthologues within the Brassicaceae.

    Directory of Open Access Journals (Sweden)

    Naghabushana K Nayidu

    Full Text Available Coding sequences for major trichome regulatory genes, including the positive regulators GLABRA 1(GL1, GLABRA 2 (GL2, ENHANCER OF GLABRA 3 (EGL3, and TRANSPARENT TESTA GLABRA 1 (TTG1 and the negative regulator TRIPTYCHON (TRY, were cloned from wild Brassica villosa, which is characterized by dense trichome coverage over most of the plant. Transcript (FPKM levels from RNA sequencing indicated much higher expression of the GL2 and TTG1 regulatory genes in B. villosa leaves compared with expression levels of GL1 and EGL3 genes in either B. villosa or the reference genome species, glabrous B. oleracea; however, cotyledon TTG1 expression was high in both species. RNA sequencing and Q-PCR also revealed an unusual expression pattern for the negative regulators TRY and CPC, which were much more highly expressed in trichome-rich B. villosa leaves than in glabrous B. oleracea leaves and in glabrous cotyledons from both species. The B. villosa TRY expression pattern also contrasted with TRY expression patterns in two diploid Brassica species, and with the Arabidopsis model for expression of negative regulators of trichome development. Further unique sequence polymorphisms, protein characteristics, and gene evolution studies highlighted specific amino acids in GL1 and GL2 coding sequences that distinguished glabrous species from hairy species and several variants that were specific for each B. villosa gene. Positive selection was observed for GL1 between hairy and non-hairy plants, and as expected the origin of the four expressed positive trichome regulatory genes in B. villosa was predicted to be from B. oleracea. In particular the unpredicted expression patterns for TRY and CPC in B. villosa suggest additional characterization is needed to determine the function of the expanded families of trichome regulatory genes in more complex polyploid species within the Brassicaceae.

  4. Transcriptome profile analysis of cell proliferation molecular processes during multicellular trichome formation induced by tomato Wov gene in tobacco

    Directory of Open Access Journals (Sweden)

    Changxian Yang

    2015-12-01

    Full Text Available Trichomes, developing from the epidermis of nearly all terrestrial plants, provide good protection from environmental stress. Regulation of trichomes in Rosids has been well characterized. However, little is known about the cell proliferation molecular processes during multicellular trichome formation in Asterids. Ectopic expression of Wov in tobacco and potato induces much more trichome formation than wild type. To gain new insights into the underlying mechanisms during the processes of these trichomes formation, RNA-seq was employed for the young primary leaf tissues in Wov transgenic and wild-type tobacco. We identified differentially expressed genes which are related to various biological processes and molecular functions. Here, we provide details of experimental methods, RNA-seq data (available at Gene Expression Omnibus database under GSE72310. Our data provide new insight into the molecular processes controlling multicellular formation in tobacco.

  5. Glandular dose in breast tomosynthesis examinations: Preliminary study with a sample of patients; Dosis glandular en examenes de tomosintesis de mama: estudio preliminar con una muestra de pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, M.; Chevalier, M.; Calzado, A.; Valverde, J.

    2013-07-01

    The aim of this study is to analyze the mean glandular dose administered to a group of patients with a tomography system (Selenia Dimensions) service installed on a large hospital in which routine tests are done and screening. (Author)

  6. Population Responses of Potato Leafhopper (Hemiptera: Cicadellidae) to Insecticide in Glandular-Haired and Non-glandular-Haired Alfalfa Cultivars.

    Science.gov (United States)

    Sulc, R Mark; McCormick, John S; Hammond, Ronald B; Miller, David J

    2014-12-01

    Conflicting results have been reported on the ability of glandular-haired alfalfa (Medicago sativa L.) cultivars to reduce potato leafhopper, Empoasca fabae Harris, population abundance in field environments. We measured potato leafhopper adult and nymph abundance and yield responses in a cultivar selected for high potato leafhopper resistance ('54H91') and in a non-glandular-haired susceptible cultivar ('54V54') with and without insecticide treatment across 3 yr. Treatments included no insecticide and insecticide applied either early or late in each summer growth cycle. Date × cultivar × treatment interactions were found for potato leafhopper population abundance. In the absence of insecticides, total potato leafhopper abundance (adults + nymphs per sweep) was lower in 54H91 than in 54V54 on 85% of sampling dates; cultivar differences were especially evident as potato leafhopper abundance peaked. Insecticide treatment reduced potato leafhopper populations in both cultivars, but populations recovered and often exceeded the normal action threshold in both cultivars within 2-3 wk of insecticide application. Yield gain from early insecticide treatment of 54V54 was >400 kg/ha in 11 of 14 summer harvests, whereas in 54H91 the yield gain was potato leafhopper resistance significantly suppress potato leafhopper adult and nymph abundance, reduce yield losses in the absence of insecticides, and have potential within an integrated pest management strategy to reduce insecticide use in alfalfa production systems. PMID:26470072

  7. Displaced Capital

    OpenAIRE

    Valerie A. Ramey; SHAPIRO, MATTHEW D

    1998-01-01

    This paper studies the efficiency with which physical capital can be reallocated across sectors. It presents a model of a firm selling specialized capital in a thin resale market. The model predicts that the selling price depends not only on the sectoral specificity of capital, but also on the thinness of the market and the discount factor of the firm. It then provides empirical evidence on the sectoral mobility of capital based on equipment-level data from aerospace industry auctions. These ...

  8. Capital budgeting

    OpenAIRE

    Dorel BERCEANU; Costel IONAŞCU

    2009-01-01

    This paper has like objective to present some aspects concerning capital budgeting. So, after a short introduction where we specify necessary conditions for a decision situation and we define investment decision and capital budgeting we made a large presentation of stages of capital budgeting process.

  9. Average glandular dose in digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Purpose: To determine the average glandular dose (AGD) in digital full-field mammography (2 D imaging mode) and in breast tomosynthesis (3 D imaging mode). Materials and Methods: Using the method described by Boone, the AGD was calculated from the exposure parameters of 2247 conventional 2 D mammograms and 984 mammograms in 3 D imaging mode of 641 patients examined with the digital mammographic system Hologic Selenia Dimensions. The breast glandular tissue content was estimated by the Hologic R2 Quantra automated volumetric breast density measurement tool for each patient from right craniocaudal (RCC) and left craniocaudal (LCC) images in 2 D imaging mode. Results: The mean compressed breast thickness (CBT) was 52.7 mm for craniocaudal (CC) and 56.0 mm for mediolateral oblique (MLO) views. The mean percentage of breast glandular tissue content was 18.0 % and 17.4 % for RCC and LCC projections, respectively. The mean AGD values in 2 D imaging mode per exposure for the standard breast were 1.57 mGy and 1.66 mGy, while the mean AGD values after correction for real breast composition were 1.82 mGy and 1.94 mGy for CC and MLO views, respectively. The mean AGD values in 3 D imaging mode per exposure for the standard breast were 2.19 mGy and 2.29 mGy, while the mean AGD values after correction for the real breast composition were 2.53 mGy and 2.63 mGy for CC and MLO views, respectively. No significant relationship was found between the AGD and CBT in 2 D imaging mode and a good correlation coefficient of 0.98 in 3 D imaging mode. Conclusion: In this study the mean calculated AGD per exposure in 3 D imaging mode was on average 34 % higher than for 2 D imaging mode for patients examined with the same CBT.

  10. Average glandular dose in digital mammography and breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Olgar, T. [Ankara Univ. (Turkey). Dept. of Engineering Physics; Universitaetsklinikum Leipzig AoeR (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Kahn, T.; Gosch, D. [Universitaetsklinikum Leipzig AoeR (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie

    2012-10-15

    Purpose: To determine the average glandular dose (AGD) in digital full-field mammography (2 D imaging mode) and in breast tomosynthesis (3 D imaging mode). Materials and Methods: Using the method described by Boone, the AGD was calculated from the exposure parameters of 2247 conventional 2 D mammograms and 984 mammograms in 3 D imaging mode of 641 patients examined with the digital mammographic system Hologic Selenia Dimensions. The breast glandular tissue content was estimated by the Hologic R2 Quantra automated volumetric breast density measurement tool for each patient from right craniocaudal (RCC) and left craniocaudal (LCC) images in 2 D imaging mode. Results: The mean compressed breast thickness (CBT) was 52.7 mm for craniocaudal (CC) and 56.0 mm for mediolateral oblique (MLO) views. The mean percentage of breast glandular tissue content was 18.0 % and 17.4 % for RCC and LCC projections, respectively. The mean AGD values in 2 D imaging mode per exposure for the standard breast were 1.57 mGy and 1.66 mGy, while the mean AGD values after correction for real breast composition were 1.82 mGy and 1.94 mGy for CC and MLO views, respectively. The mean AGD values in 3 D imaging mode per exposure for the standard breast were 2.19 mGy and 2.29 mGy, while the mean AGD values after correction for the real breast composition were 2.53 mGy and 2.63 mGy for CC and MLO views, respectively. No significant relationship was found between the AGD and CBT in 2 D imaging mode and a good correlation coefficient of 0.98 in 3 D imaging mode. Conclusion: In this study the mean calculated AGD per exposure in 3 D imaging mode was on average 34 % higher than for 2 D imaging mode for patients examined with the same CBT.

  11. Handbook of glandular tissue doses in mammography. Final report March 1985

    International Nuclear Information System (INIS)

    This Handbook contains data from which absorbed dose to glandular tissue in the breast (glandular tissue dose) can be estimated for mammographic procedures. The breast (excluding the skin) is a composite of adipose (i.e., fatty) and glandular (i.e., other soft) tissues. The glandular tissue is the tissue considered at risk for breast cancer. The intent of the Handbook is to permit the user to compute glandular tissue dose for various techniques in mammography as a function of breast compression, breast size, breast composition, and the quality of the x-ray beam. The method used to compute most of the basic data was a radiation transport calculation using a specialized version of a computer code developed at the Oak Ridge National Laboratory (Warner, 1973). The results of the calculations were then converted into the Handbook entries, using the specific characteristics of current mammographic techniques. Additional data are reproduced from previous work of others

  12. Additional factors for the estimation of mean glandular breast dose using the UK mammography dosimetry protocol

    International Nuclear Information System (INIS)

    The UK and European protocols for mammographic dosimetry use conversion factors that relate incident air kerma to the mean glandular dose (MGD) within the breast. The conversion factors currently used were obtained by computer simulation of a model breast with a composition of 50% adipose and 50% glandular tissues by weight (50% glandularity). Relative conversion factors have been calculated which allow the extension of the protocols to breasts of varying glandularity and for a wider range of mammographic x-ray spectra. The data have also been extended to breasts of a compressed thickness of 11 cm. To facilitate the calculation of MGD in patient surveys, typical breast glandularities are tabulated for women in the age ranges 40-49 and 50-64 years, and for breasts in the thickness range 2-11 cm. In addition, tables of equivalent thickness of polymethyl methacrylate have been provided to allow the simulation for dosimetric purposes of typical breasts of various thicknesses. (author)

  13. Estimation of mean glandular dose for mammography of augmented breasts

    Science.gov (United States)

    Beckett, J. R.; Kotre, C. J.

    2000-11-01

    The standard quantity used to relate breast surface exposure to radiation risk is the mean dose received by the radiation sensitive tissue contained within the female breast, the mean glandular dose (MGD). At present, little is known about the MGD received by women with breast implants as there is no technique available to facilitate its calculation. The present work has involved modification of the conventional method for MGD estimation to make it applicable to women with augmented breasts. The technique was used to calculate MGDs for a cohort of 80 women with breast implants, which were compared with similar data calculated for a total of 1258 non-augmented women. Little difference was found in median MGD at low compressed breast thickness. At high breast thickness, however, the MGDs received by women with augmented breasts were found to be considerably lower than those relating to their non-augmented counterparts.

  14. Estimation of mean glandular dose for mammography of augmented breasts

    International Nuclear Information System (INIS)

    The standard quantity used to relate breast surface exposure to radiation risk is the mean dose received by the radiation sensitive tissue contained within the female breast, the mean glandular dose (MGD). At present, little is known about the MGD received by women with breast implants as there is no technique available to facilitate its calculation. The present work has involved modification of the conventional method for MGD estimation to make it applicable to women with augmented breasts. The technique was used to calculate MGDs for a cohort of 80 women with breast implants, which were compared with similar data calculated for a total of 1258 non-augmented women. Little difference was found in median MGD at low compressed breast thickness. At high breast thickness, however, the MGDs received by women with augmented breasts were found to be considerably lower than those relating to their non-augmented counterparts. (author)

  15. The costs of anti-herbivore defense traits in agricultural crop plants: a case study involving leafhoppers and trichomes.

    Science.gov (United States)

    Kaplan, Ian; Dively, Galen P; Denno, Robert F

    2009-06-01

    The expression of plant defenses is thought to entail costs (e.g., the allocation of resources away from growth or reproduction) that constrain the evolution of plant genotypes maximally defended against herbivores. Although central to the ecological theory underlying plant-insect interactions at large, the concept of defense costs is particularly evident in agricultural crops where plants may be under simultaneous selection for enhanced growth and/or reproduction (i.e., yield) and anti-herbivore resistance traits that deter pests. In this study we investigate the role of trichomes as a resistance mechanism against a sap-feeding insect (the leafhopper, Empoasca fabae) on potato. Natural variation in trichome density among 17 potato cultivars was used to test for the role of trichomes as a putative defense against leafhoppers, and evidence of costs in trichome expression. Two different types of costs were explored: (1) allocation costs (i.e., the relationship between trichomes and yield), and (2) costs involving trade-offs with alternative defense strategies (e.g., tolerance). Although leafhopper abundance did not decrease as trichome density increased, leafhopper injury to potato plants (foliar necrosis) was negatively correlated with trichome density. As a result, the per capita effect of leafhopper adults and nymphs on foliar damage was lower on plants with high trichome densities. We found no evidence, however, for costs of expressing this resistance trait; trichomes were not correlated with either potato yield or tolerance to herbivory. Thus, selection for multiple plant defenses to alleviate the impact of pests in agronomic crops may indeed be possible without inherent losses in plant yield. PMID:19544730

  16. Expression of β-glucosidase increases trichome density and artemisinin content in transgenic Artemisia annua plants.

    Science.gov (United States)

    Singh, Nameirakpam Dolendro; Kumar, Shashi; Daniell, Henry

    2016-03-01

    Artemisinin is highly effective against multidrug-resistant strains of Plasmodium falciparum, the aetiological agent of the most severe form of malaria. However, a low level of accumulation of artemisinin in Artemisia annua is a major limitation for its production and delivery to malaria endemic areas of the world. While several strategies to enhance artemisinin have been extensively explored, enhancing storage capacity in trichome has not yet been considered. Therefore, trichome density was increased with the expression of β-glucosidase (bgl1) gene in A. annua through Agrobacterium-mediated transformation. Transgene (bgl1) integration and transcript were confirmed by molecular analysis. Trichome density increased up to 20% in leaves and 66% in flowers of BGL1 transgenic plants than Artemisia control plants. High-performance liquid chromatography, time of flight mass spectrometer data showed that artemisinin content increased up to 1.4% in leaf and 2.56% in flowers (per g DW), similar to the highest yields achieved so far through metabolic engineering. Artemisinin was enhanced up to five-fold in BGL1 transgenic flowers. This study opens the possibility of increasing artemisinin content by manipulating trichomes' density, which is a major reservoir of artemisinin. Combining biosynthetic pathway engineering with enhancing trichome density may further increase artemisinin yield in A. annua. Because oral feeding of Artemisia plant cells reduced parasitemia more efficiently than the purified drug, reduced drug resistance and cost of prohibitively expensive purification process, enhanced expression should play a key role in making this valuable drug affordable to treat malaria in a large global population that disproportionally impacts low-socioeconomic areas and underprivileged children. PMID:26360801

  17. Breast Glandularity in Malaysian Women from a Full-Field Digital Mammography System

    International Nuclear Information System (INIS)

    This study is undertaken to estimate breast glandularity in Malaysian women from a Full-Field Digital mammography System. This study involved 223 women (Malay=100;Chinese=101 and Indian=22) underwent voluntary screening mammography at Breast Centre, International Islamic University Malaysia (IIUM Breast Centre) for the first quarter of year 2009. Those are women aged between 31 to 69 years old (median age, 49 years). Data on miliampere-seconds, kilo voltage and compressed breast thickness for each cranio caudal view are used to estimate breast glandularity for an individual breast. Breast glandularity is calculated using the fitted equation reported earlier. The difference in breast glandularity among ethnic groups was tested for significance using the nonparametric Kruskal-Wallis test. The average breast glandularity estimated in our study, using FFDM system is 52.94±27.63 %. No significant difference was seen in breast glandularity among the ethnic groups (p>0.05, Kruskan Wallis test). Breast glandularity decrease as age increases, up to 60 years old. (author)

  18. Intellectual Capital

    DEFF Research Database (Denmark)

    Mouritsen, Jan; Bukh, Per Nikolaj

    2015-01-01

    Intellectual capital (IC) consists of human capital, organizational capital, and relational capital, and their relationships. It has been said to be important to explain the difference between market value and book value of a firm, but measurement of IC is more likely to be important because it...... forms a starting point for understanding and managing value-creating processes. Three distinct agendas within IC management and research can be identified. The first concerns to measure the components of IC, the second attempts to relate indicators to effects using statistical models, while the third...

  19. FORTRAN Code for Glandular Dose Calculation in Mammography Using Sobol-Wu Parameters

    Directory of Open Access Journals (Sweden)

    Mowlavi A A

    2007-07-01

    Full Text Available Background: Accurate computation of the radiation dose to the breast is essential to mammography. Various the thicknesses of breast, the composition of the breast tissue and other variables affect the optimal breast dose. Furthermore, the glandular fraction, which refers to the composition of the breasts, as partitioned between radiation-sensitive glandular tissue and the adipose tissue, also has an effect on this calculation. Fatty or fibrous breasts would have a lower value for the glandular fraction than dense breasts. Breast tissue composed of half glandular and half adipose tissue would have a glandular fraction in between that of fatty and dense breasts. Therefore, the use of a computational code for average glandular dose calculation in mammography is a more effective means of estimating the dose of radiation, and is accurate and fast. Methods: In the present work, the Sobol-Wu beam quality parameters are used to write a FORTRAN code for glandular dose calculation in molybdenum anode-molybdenum filter (Mo-Mo, molybdenum anode-rhodium filter (Mo-Rh and rhodium anode-rhodium filter (Rh-Rh target-filter combinations in mammograms. The input parameters of code are: tube voltage in kV, half-value layer (HVL of the incident x-ray spectrum in mm, breast thickness in cm (d, and glandular tissue fraction (g. Results: The average glandular dose (AGD variation against the voltage of the mammogram X-ray tube for d = 4 cm, HVL = 0.34 mm Al and g=0.5 for the three filter-target combinations, as well as its variation against the glandular fraction of breast tissue for kV=25, HVL=0.34, and d=4 cm has been calculated. The results related to the average glandular absorbed dose variation against HVL for kV = 28, d=4 cm and g= 0.6 are also presented. The results of this code are in good agreement with those previously reported in the literature. Conclusion: The code developed in this study calculates the glandular dose quickly, and it is complete and

  20. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    International Nuclear Information System (INIS)

    Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgNhetero) and homogeneous (pDgNhomo) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgNhetero coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgNhomo coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgNhetero relative to pDgNhomo of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width in the superior and

  1. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Andrew M., E-mail: amhern@ucdavis.edu [Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States); Seibert, J. Anthony; Boone, John M. [Departments of Radiology and Biomedical Engineering, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States)

    2015-11-15

    Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the

  2. Herbivore handling of a plant's trichome: the case of Heliconius charithonia (L.) (Lepidoptera: Nymphalidae) and Passiflora lobata (Killip) Hutch. (Passifloraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Marcio Z. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Biociencias. Dept. de Botanica, Ecologia e Zoologia]. E-mail: mzc@cb.ufrn.br

    2008-05-15

    Trichomes reduce herbivore attack on plants by physically and/or chemically inhibiting movement or other activities. Despite evidence that herbivores are negatively affected by trichomes there also reports of insect counter-adaptations that circumvent the plant's defense. This paper reports on a study that investigated the likely mechanisms employed by larvae of the nymphalid butterfly, Heliconius charithonia (L.), that allow it to feed on a host that is presumably protected by hooked trichomes (Passiflora lobata (Killip) Hutch). Evidence were gathered using data from direct observations of larval movement and behavior, faeces analysis, scanning electron microscopy of plant surface and experimental analysis of larval movement on plants with and without trichomes (manually removed). The latter involved a comparison with a non specialist congener, Heliconius pachinus Salvin. Observations showed that H. charithonia larvae are capable of freeing themselves from entrapment on trichome tips by physical force. Moreover, wandering larvae lay silk mats on the trichomes and remove their tips by biting. In fact, trichome tips were found in the faeces. Experimental removal of trichomes aided in the movement of the non specialist but had no noticeable effect on the specialist larvae. These results support the suggestion that trichomes are capable of deterring a non specialist herbivore (H. pachinus). The precise mechanisms that allow the success of H. charithonia are not known, but I suggest that a blend of behavioral as well as physical resistance mechanisms is involved. Future studies should ascertain whether larval integument provides physical resistance to trichomes. (author)

  3. Effect of plant trichomes on the vertical migration of Haemonchus contortus infective larvae on five tropical forages.

    Science.gov (United States)

    Oliveira, Aruaque L F; Costa, Ciniro; Rodella, Roberto A; Silva, Bruna F; Amarante, Alessandro F T

    2009-06-01

    The influence of trichomes on vertical migration and survival of Haemonchus contortus infective larvae (L3) on different forages was investigated. Four different forages showing different distributions of trichomes (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Xaraes, Andropogon gayanus, and Stylosanthes spp.), and one forage species without trichomes (Panicum maximum cv. Tanzania), were used. Forages cut at the post-grazing height were contaminated with faeces containing L3. Samples of different grass strata (0-10, 10-20, >20 cm) and faeces were collected for L3 quantification once per week over four weeks. In all forages studied, the highest L3 recovery occurred seven days after contamination, with the lowest recovery on A. gayanus. In general, larvae were found on all forages' strata. However, most of the larvae were at the lower stratum. There was no influence of trichomes on migration and survival of H. contortus L3 on the forages. PMID:18975119

  4. Capital gains

    International Nuclear Information System (INIS)

    This article examines African and Middle East oil and natural gas project financing. Capital markets financing, Ras Laffan's project bonds, capital market issues in Saudi Arabia, the movement toward gas and away from oil, and Islamic opportunities are discussed, African and Middle East oil and gas projects are listed. (UK)

  5. Celebration Capitalism

    OpenAIRE

    Boykoff, Jules

    2014-01-01

    Capitalism is a nimble shapeshifter. In this talk Jules Boykoff draws from the history of the Olympic Games to offer a theory of “celebration capitalism,” a form of modern-day economics that complements Naomi Klein’s “disaster capitalism” marked by neoliberalism: privatization, deregulation, and free-market rhetoric.

  6. Resistance of tomato strains to the moth Tuta absoluta imparted by allelochemicals and trichome density Resistência de linhagens de tomateiro à traça Tuta absoluta, relacionada a aleloquímicos e à densidade de tricomas

    Directory of Open Access Journals (Sweden)

    Celso Mattes de Oliveira

    2012-02-01

    Full Text Available We examined the resistance of improved tomato strains rich in 2-tridecanone (2-TD, zingiberene (ZGB and acyl sugars (AA to the tomato moth, Tuta absoluta. We also studied whether selection for strains with higher densities of glandular trichomes, and thus presumably strains with higher concentrations of 2-tridecanone, was effective in promoting greater resistance to the moth. The TOM-584 and TOM-679 strains were used as susceptible controls, which have normal concentrations of the three allelochemicals. The improved strain TOM-687, which has a high AA content, has a widely documented resistance and was used as a standard resistant strain. The wild strain PI134417, which is resistant by means of its high 2-TD content, was also used as a standard resistant strain. The experiment was installed in a greenhouse with a completely randomized design. The wild strain PI 134417 was confirmed as being highly resistant. TOM-622 (rich in 2-TD, ZGB-703 (rich in ZGB, and TOM-687 (rich in AA showed significant reductions in the oviposition rate of the tomato moth, damage to the plants, injury to the leaflets, and the percentage of leaflets attacked in comparison with the control strains (TOM-584 and TOM-679. The levels of resistance to the moth for the TOM-622, ZGB-703, and TOM-687 strains were similar. In general, the genotypes with higher densities of glandular trichomes had greater resistance than the susceptible controls, with the strain BPX-367D-238-02 being particularly notable in its resistance.Comparou-se a efetividade de linhagens melhoradas de tomateiro, ricas em 2-tridecanona (2-TD, zingibereno (ZGB e acilaçúcares (AA, em relação aos níveis de resistência à traça-do-tomateiro Tuta absoluta. Verificaram-se, também, se linhagens selecionadas para maiores densidades de tricomas glandulares, presumivelmente com maiores níveis de 2-tridecanona, são efetivas em promover maior resistência à traça. Como testemunhas suscetíveis foram utilizadas

  7. Glandular dose in breast tomosynthesis examinations: Preliminary study with a sample of patients

    International Nuclear Information System (INIS)

    The aim of this study is to analyze the mean glandular dose administered to a group of patients with a tomography system (Selenia Dimensions) service installed on a large hospital in which routine tests are done and screening. (Author)

  8. Diagnostic and therapeutic dilemma associated with atypical glandular cells on liquid-based cervical cytology.

    LENUS (Irish Health Repository)

    Chummun, K

    2012-12-01

    In 2008, the management of women in Ireland with atypical glandular cells changed to immediate referral to colposcopy. The optimal management of these women is unclear. A balance between the detection of occult disease and overtreatment is required.

  9. Combined Roles of Glandular-haired Alfalfa and Natural Enemies in Alfalfa Pest Managment in Virginia

    OpenAIRE

    Dellinger, Theresa Ann

    2003-01-01

    Both alfalfa weevil, Hypera postica (Gyllenhal), (Coleoptera: Curculionidae), and potato leafhopper, Empoasca fabae (Harris), (Homoptera: Cicadellidae), remain key pests of alfalfa in Virginia. Commercial varieties of potato leafhopper-resistant (or glandular-haired) alfalfa were released in the mid-1990s, but the impact of alfalfa weevil on these varieties has not been well documented. In 1999, two large-scale field experiments were initiated to compare the performance of a glandular-hair...

  10. CAPITAL STRUCTURE AND VENTURE CAPITAL

    Directory of Open Access Journals (Sweden)

    Becsky-Nagy Patricia

    2015-07-01

    Full Text Available Venture capital significantly changes the capital structure of the portfolio company at the time of the investment. Venture capitalists contribute to the company’s success through their active involvement in the management and their added value appears in the increase of the value of the equity. At the same time with taking active role in the management, agency problem occurs, that complicates the cooperation and the success of exit. In this article we search the answer for the question whether the preferred equity, that are commonly used in the US for bridging the agency problem, are used and able to help Hungarian venture capitalists to manage agency problems. On the other hand we examined how the venture capital affect capital structure, how the venture capitalists value added appear in the capital structure. During the evaluation of the three case studies, we came to the conclusion, that the venture capital investments have positive effect on the liabilities of the enterprises, as the capital structure indexes show. However, the investors need the ownership, which help them to step up resolutely, when things change for the worse, and companies need the expertise, which the investors bring with their personal assistance. The investor’s new attitude also has positive effect on a mature company, which has an experienced leader, because he can show another aspect, as a person who come from outside. During the examination of the capital structure, we cannot disregard the events of the company’s environment, which have effects on the firm. The investor’s decisions also appear different ways. Because of this, every venture capital investment is different, just as the capital structure of the firms, in which they invest.

  11. Micromorphology of trichomes in the flowers of the horse chestnut Aesculus hippocastanum L.

    OpenAIRE

    Mirosława Chwil; Elżbieta Weryszko-Chmielewska; Aneta Sulborska; Magdalena Michońska

    2014-01-01

    Aesculus hippocastanum L. is an ornamental tree appreciated for its beautiful flowers and leaves. The flowers of this species contain secondary metabolites exhibiting pharmacological activity. They also produce essential oils and coloured “nectar guides”, which enable insects to reach nectar and pollen. The aim of the study was to investigate the types and characteristics of chestnut flower trichomes, which may contain biologically active substances. The analyses were performed using light, f...

  12. Is nectar reabsorption restricted by the stalk cells of floral and extrafloral nectary trichomes?

    Science.gov (United States)

    Cardoso-Gustavson, P; Davis, A R

    2015-01-01

    Reabsorption is a phase of nectar dynamics that occurs concurrently with secretion; it has been described in floral nectaries that exude nectar through stomata or unicellular trichomes, but has not yet been recorded in extrafloral glands. Apparently, nectar reabsorption does not occur in multicellular secretory trichomes (MST) due to the presence of lipophilic impregnations - which resemble Casparian strips - in the anticlinal walls of the stalk cells. It has been assumed that these impregnations restrict solute movement within MST to occur unidirectionally and exclusively by the symplast, thereby preventing nectar reflux toward the underlying nectary tissues. We hypothesised that reabsorption is absent in nectaries possessing MST. The fluorochrome lucifer yellow (LYCH) was applied to standing nectar of two floral and extrafloral glands of distantly related species, and then emission spectra from nectary sections were systematically analysed using confocal microscopy. Passive uptake of LYCH via the stalk cells to the nectary tissues occurred in all MST examined. Moreover, we present evidence of nectar reabsorption in extrafloral nectaries, demonstrating that LYCH passed the stalk cells of MST, although it did not reach the deepest nectary tissues. Identical (control) experiments performed with neutral red (NR) demonstrated no uptake of this stain by actively secreting MST, whereas diffusion of NR did occur in plasmolysed MST of floral nectaries at the post-secretory phase, indicating that nectar reabsorption by MST is governed by stalk cell physiology. Interestingly, non-secretory trichomes failed to reabsorb nectar. The role of various nectary components is discussed in relation to the control of nectar reabsorption by secretory trichomes. PMID:24987788

  13. Trichomes of tobacco excrete zinc as zinc-substituted calciumcarbonate and other zinc-containing compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sarret, G.; Harada, E.; Choi, Y-E.; Isaure, M.-P.; Geoffroy, N.; Fakra, S.; Marcus, M.A.; Birschwilks, M.; Clemens, S.; Manceau, A.

    2006-01-01

    Tobacco (Nicotiana tabacum L. cv Xanthi) plants were exposed to toxic levels of zinc (Zn). Zn exposure resulted in toxicity signs in plants, and these damages were partly reduced by a calcium (Ca) supplement. Confocal imaging of intracellular Zn using Zinquin showed that Zn was preferentially accumulated in trichomes. Exposure to Zn and Zn + Ca increased the trichome density and induced the production of Ca/Zn mineral grains on the head cells of trichomes. These grains were aggregates of submicrometer-sized crystals and poorly crystalline material and contained Ca as major element, along with subordinate amounts of Zn, manganese, potassium, chlorine, phosphorus, silicon, and magnesium. Micro x-ray diffraction revealed that the large majority of the grains were composed essentially of metal-substituted calcite (CaCO3). CaCO3 polymorphs (aragonite and vaterite) and CaC2O4 (Ca oxalate) mono- and dihydrate also were identified, either as an admixture to calcite or in separate grains. Some grains did not diffract, although they contained Ca, suggesting the presence of amorphous form of Ca. The presence of Zn-substituted calcite was confirmed by Zn K-edge micro-extended x-ray absorption fine structure spectroscopy. Zn bound to organic compounds and Zn-containing silica and phosphate were also identified by this technique. The proportion of Zn-substituted calcite relative to the other species increased with Ca exposure. The production of Zn-containing biogenic calcite and other Zn compounds through the trichomes is a novel mechanism involved in Zn detoxification. This study illustrates the potential of laterally resolved x-ray synchrotron radiation techniques to study biomineralization and metal homeostasis processes in plants.

  14. Influence of phenolglucosides and trichome density on the distribution of insects herbivores on willows

    OpenAIRE

    Soetens, Ph.; Rowell-Rahier, Martine; Pasteels, Jacques M.

    2009-01-01

    The effects of both trichome density and phenolglucoside content of leaves of 76 willow hybrids (Salix alba x fragilis) were measured to estimate their influence on the distribution of Phratora vitellinae (L.), Plagiodera versicolora Baly (Coleoptera: Chrysomelidae) and Pontania proxima (Lepeletier 1823) (Hymenoptera: Tenthredinidae) in a nursery at Gramont, Belgium. The willows showed differences in their phenolglucoside content and pilosity of leaves and are classified on these basis into ...

  15. DOSTOYEVSKI'S "CAPITAL"

    OpenAIRE

    GUNAL, E. Zeynep

    2012-01-01

    Dostoyevski who was always in need of money and in debt, wrote two great novels about capital: "Idiot" and "Crime and Punishment". In these novels the writer tries to prove the negative effects of capital on people. This article particularly focuses on "Crime and Punishment". Because crime is discussed as the multi-dimensional factor in this work. Moreover, it is claimed that in the troika of crime which formed of Raskolnikov, Svidrigaylov and Luzhin, Luzhin is the most dangerous character w...

  16. Intellectual Capital

    OpenAIRE

    Mardešič, Jakub

    2011-01-01

    The work is focused on intellectual capital and its reporting of intangible assets. First part of the work defines the basic theoretical principles, which are an essential part of the work for understanding the issue. Literature review discusses the various components of intellectual capital and focuses on their function within organizations. Work also discusses various approaches of literature and the authors developing a complex theoretical basis for this issue. The following practical part...

  17. Capitalizing China

    OpenAIRE

    Joseph Fan; Randall Morck; Bernard Yeung

    2011-01-01

    Despite a vast accumulation of private capital, China is not embracing capitalism. Deceptively familiar capitalist features disguise the profoundly unfamiliar foundations of "market socialism with Chinese characteristics." The Chinese Communist Party (CCP), by controlling the career advancement of all senior personnel in all regulatory agencies, all state-owned enterprises (SOEs), and virtually all major financial institutions state-owned enterprises (SOEs), and senior Party positions in all ...

  18. Mineral nutrient uptake from prey and glandular phosphatase activity as dual test of carnivory in semidesert plants with glandular leaves suspected of carnivory

    Czech Academy of Sciences Publication Activity Database

    Plachno, B.J.; Adamec, Lubomír; Huet, H.

    2009-01-01

    Roč. 104, č. 4 (2009), s. 649-654. ISSN 0305-7364 Institutional research plan: CEZ:AV0Z60050516 Keywords : mineral nutrient uptake * phosphatases * glandular leaves Subject RIV: EF - Botanics Impact factor: 3.501, year: 2009

  19. Transcriptome analysis approaches for the isolation of trichome-specific genes from the medicinal plant Cistus creticus subsp. creticus.

    Science.gov (United States)

    Falara, Vasiliki; Fotopoulos, Vasileios; Margaritis, Thanasis; Anastasaki, Thalia; Pateraki, Irene; Bosabalidis, Artemios M; Kafetzopoulos, Dimitris; Demetzos, Costas; Pichersky, Eran; Kanellis, Angelos K

    2008-12-01

    Cistus creticus subsp. creticus is a plant of intrinsic scientific interest due to the distinctive pharmaceutical properties of its resin. Labdane-type diterpenes, the main constituents of the resin, exhibit considerable antibacterial and cytotoxic activities. In this study chemical analysis of isolated trichomes from different developmental stages revealed that young leaves of 1-2 cm length displayed the highest content of labdane-type diterpenes (80 mg/g fresh weight) whereas trichomes from older leaves (2-3 or 3-4 cm) exhibited gradual decreased concentrations. A cDNA library was constructed enriched in transcripts from trichomes isolated from young leaves, which are characterized by high levels of labdane-type diterpenes. Functional annotation of 2,022 expressed sequence tags (ESTs) from the trichome cDNA library based on homology to A. thaliana genes suggested that 8% of the putative identified sequences were secondary metabolism-related and involved primarily in flavonoid and terpenoid biosynthesis. A significant proportion of the ESTs (38%) displayed no significant similarity to any other DNA deposited in databases, indicating a yet unknown function. Custom DNA microarrays constructed with 1,248 individual clones from the cDNA library facilitated transcriptome comparisons between trichomes and trichome-free tissues. In addition, gene expression studies in various Cistus tissues and organs for one of the genes highlighted as the most differentially expressed by the microarray experiments revealed a putative sesquiterpene synthase with a trichome-specific expression pattern. Full length cDNA isolation and heterologous expression in E. coli followed by biochemical analysis, led to the characterization of the produced protein as germacrene B synthase. PMID:18819010

  20. A calibration approach to glandular tissue composition estimation in digital mammography

    International Nuclear Information System (INIS)

    The healthy breast is almost entirely composed of a mixture of fatty, epithelial, and stromal tissues which can be grouped into two distinctly attenuating tissue types: fatty and glandular. Further, the amount of glandular tissue is linked to breast cancer risk, so an objective quantitative analysis of glandular tissue can aid in risk estimation. Highnam and Brady have measured glandular tissue composition objectively. However, they argue that their work should only be used for 'relative' tissue measurements unless a careful calibration has been performed. In this work, we perform such a 'careful calibration' on a digital mammography system and use it to estimate breast tissue composition of patient breasts. We imaged 0%, 50%, and 100% glandular-equivalent phantoms of varying thicknesses for a number of clinically relevant x-ray techniques on a digital mammography system. From these images, we extracted mean signal and noise levels and computed calibration curves that can be used for quantitative tissue composition estimation. In this way, we calculate the percent glandular composition of a patient breast on a pixelwise basis. This tissue composition estimation method was applied to 23 digital mammograms. We estimated the quantitative impact of different error sources on the estimates of tissue composition. These error sources include compressed breast height estimation error, residual scattered radiation, quantum noise, and beam hardening. Errors in the compressed breast height estimate contribute the most error in tissue composition--on the order of ±7% for a 4 cm compressed breast height. The spatially varying scattered radiation will contribute quantitatively less error overall, but may be significant in regions near the skinline. It is calculated that for a 4 cm compressed breast height, a residual scatter signal error is mitigated by approximately sixfold in the composition estimate. The error in composition due to the quantum noise, which is the limiting

  1. Investigation of mean glandular dose versus compressed breast thickness relationship for mammography

    International Nuclear Information System (INIS)

    The relationship between the mean glandular dose (MGD) and the compressed breast thickness (CBT) is commonly used for the presentation of mammographic dose survey results and could also be useful for the assessment of individual breast doses retrospectively in case of lack of necessary dosimetric instrumentation. The high data scattering from the best fit reduces the reliability of this technique. The aim of this study was to investigate the accuracy of this relationship using the data collected from a patient survey and phantom experiment. Patients were divided into three different groups according to their breast glandularities, which were predicted from the inspection of previous mammograms. X-ray beam qualities that will be used in patient examinations were determined according to breast thickness and predicted glandularities. The MGD versus CBT relationship for all the examined patients resulted in a poor correlation (R2 = 0.28). This relationship was separately obtained for each glandularity group and also for sub-groups of specific beam qualities. The best correlation (R2 = 0.73) was obtained for the fatty breast group and Mo/Mo combination. A low correlation (R2 = 0.34) was observed in the mid-glandularity group due to inclusion of a wide range of glandularities in this group. In the case of the dense breast group, although the glandularity range was narrow, there were e still high data scattering (R2 = 0.25). This was probably due to the use of Mo/Rh and Mo/Mo combinations. This is validated by obtaining the MGD-CBT relationship specific to Mo/Mo combination (R2 = 0.61). (authors)

  2. Intelligence Capital

    Directory of Open Access Journals (Sweden)

    Maid Pajevic

    2011-08-01

    Full Text Available The author of this article presents a new theoretical concept of intelligence capital, with which he explains the multi-meaningful term ‘intelligence’. The author offers a conceptual frame „intelligence capital“ as a generic complex consisting of four interactively linked elements. The contribution of this article is, among other things, an answer to a question: What is an applicative value of intelligence capital as a new theoretical concept for the sys­tem of security and intelligence of BiH? Historical context implies greater responsibility of OSA BiH in realising its preventive function of protecting security of BiH and its citizens. Theoretical frame of the intelligence capital implies that the system of security and intelligence of BiH should be able to respond to strategic questions: to know-what, to know – why, to know – how, to know – who.

  3. Intelligence Capital

    OpenAIRE

    Maid Pajevic

    2011-01-01

    The author of this article presents a new theoretical concept of intelligence capital, with which he explains the multi-meaningful term ‘intelligence’. The author offers a conceptual frame „intelligence capital“ as a generic complex consisting of four interactively linked elements. The contribution of this article is, among other things, an answer to a question: What is an applicative value of intelligence capital as a new theoretical concept for the sys­tem of security and intelligence of Bi...

  4. Trinidadian capitalism

    OpenAIRE

    Kevin A. Yelvington

    1999-01-01

    [First paragraph] Capitalism: An Ethnographic Approach. DANIEL MILLER. Oxford: Berg, 1997. x + 357 pp. (Cloth £39.00, Paper £17.99) Women, Labour and Politics in Trinidad and Tobago: A History. RHODA E. REDDOCK. London: Zed, 1994. vi + 346 pp. (Cloth £39.95, Paper £15.95) Despite the underdeveloped state of the scholarship on its admittedly short sugar plantation slavery period, we now have a corpus of studies on various aspects of capitalism in Trinidad - from its histor...

  5. Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

    DEFF Research Database (Denmark)

    husted, Louise; Jensen, Tim Kåre; Olsen, Susanne N.;

    2010-01-01

    Background: The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses. Results: Stomach lesions, as well as normal...... by cloning and sequencing. Mucosal lesions were found in 36/63 stomachs and included hyperplastic rugae, polypoid structures and focal erosions. None of the samples were tested positive for urease activity or for FISH using the Helicobacter genus specific probe. In samples of lesions, as well as...... Enterococcus faecium. The Enterococcus were found colonising the mucosal surface, while E. fergusonii organisms were also demonstrated intraepithelial. Conclusion: Gastric Helicobacter spp. could not be verified as being involved in lesions of the glandular stomach of the horse. Since E. fergusonii has been...

  6. Allergy Capitals

    Science.gov (United States)

    ... McAllen, TX The report looks at 3 important factors: Pollen score Allergy medication usage Availability of Board-certified allergists This year’s report named Jackson, Mississippi, as the top Spring Allergy Capital due to its: Higher than average pollen Higher ...

  7. Dream capitalism

    OpenAIRE

    Pierson, Christopher

    2015-01-01

    John Tomasi’s Free Market Fairness represents an heroic attempt to bridge the gap between Rawlsian ‘high liberals’ and the advocates of classical liberalism/contemporary libertarianism. I argue that Tomasi’s project fails, above all because it cannot give a compelling account of contemporary (American) capitalism or of its capacity to deliver free market fairness.

  8. Formicdubius Philips & Scholtz from South Africa, a junior synonym of Haroldius Boucomont, and a survey of the trichomes in the African species (Coleoptera, Scarabaeidae, Onthophagini

    Directory of Open Access Journals (Sweden)

    Frank Krell

    2010-01-01

    Full Text Available Formicdubius Philips & Scholtz, 2000, a genus of South African scarab dung beetle, is synonymised with Haroldius Boucomont, 1914. All four African species of Haroldius, formerly in the genus Afroharoldius Janssens, possess trichomes. Trichome location and degree of development in the African species are discussed. The first record of Haroldius modestus Janssens from Malawi is given.

  9. Control of trichome formation in Arabidopsis by poplar single-repeat R3 MYB transcription factors

    Directory of Open Access Journals (Sweden)

    Limei eZhou

    2014-06-01

    Full Text Available In Arabidopsis, trichome formation is regulated by the interplay of R3 MYBs and several others transcription factors including the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1, the R2R3 MYB transcription factor GLABRA1 (GL1, the bHLH transcription factor GLABRA3 (GL3 or ENHANCER OF GLABRA3 (EGL3, and the homeodomain protein GLABRA2 (GL2. R3 MYBs including TRICHOMELESS1 (TCL1, TRYPTICHON (TRY, CAPRICE (CPC, ENHANCER OF TRY AND CPC1 (ETC1, ETC2 and ETC3 negatively regulate trichome formation by competing with GL1 for binding GL3 or EGL3, thus blocking the formation of TTG1-GL3/EGL3-GL1, an activator complex required for the activation of the trichome positive regulator gene GL2. However, it is largely unknown if R3 MYBs in other plant species especially woody plants have similar functions. By BLASTing the Populus trichocarpa protein database using the entire amino acid sequence of TCL1, an Arabidopsis R3 MYB transcription factor, we identified a total of eight R3 MYB transcription factor genes in poplar, namely Populus trichocarpa TRICHOMELESS1through 8 (PtrTCL1-PtrTCL8. The amino acid signature required for interacting with bHLH transcription factors and the amino acids required for cell-to-cell movement of R3 MYBs are not fully conserved in all PtrTCLs. When tested in Arabidopsis protoplasts, however, all PtrTCL interacted with GL3. Expressing each of the eight PtrTCLs genes in Arabidopsis resulted in either glabrous phenotypes or plants with reduced trichome numbers, and expression levels of GL2 in all transgenic plants tested were greatly reduced. Expression of PtrTCL1 under the control of TCL1 native promoter almost completely complemented the mutant phenotype of tcl. In contrast, expression of PtrTCL1 under the control of TRY native promoter in the try mutant, or under the control of CPC native promoter in the cpc mutant resulted in glabrous phenotypes, suggesting that PtrTCL1 functions similarly to TCL1, but not TRY and CPC.

  10. Control of trichome formation in Arabidopsis by poplar single-repeat R3 MYB transcription factors

    OpenAIRE

    Limei eZhou; Kaijie eZheng; Xiaoyu eWang; Hainan eTian; Xianling eWang; Shucai eWang

    2014-01-01

    In Arabidopsis, trichome formation is regulated by the interplay of R3 MYBs and several others transcription factors including the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1), the R2R3 MYB transcription factor GLABRA1 (GL1), the bHLH transcription factor GLABRA3 (GL3) or ENHANCER OF GLABRA3 (EGL3), and the homeodomain protein GLABRA2 (GL2). R3 MYBs including TRICHOMELESS1 (TCL1), TRYPTICHON (TRY), CAPRICE (CPC), ENHANCER OF TRY AND CPC1 (ETC1), ETC2 and ETC3 negatively regulate trich...

  11. A Methodology for Obtaining the Mean Glandular Dose in Mammography Exams

    International Nuclear Information System (INIS)

    This study proposes to validate measurements of mean glandular dose quantity (DG) for a given thickness and glandularity of compressed breast based in a PMMA phantom. 10 exposures were made in an ionization chamber in conventional mammographic equipment for a research. It obtained an average value for the incident air kerma, Ka,I = 9.59 mGy leading to a DG = 1.82 mGy. Experimental results too were obtained for the acquisition of this quantity in other mammography clinics and these results were also reported and discussed. After the comparison of the results the methodology was validated

  12. Evaluation of subject contrast and normalized average glandular dose by semi-analytical models

    International Nuclear Information System (INIS)

    In this work, two semi-analytical models are described to evaluate the subject contrast of nodules and the normalized average glandular dose in mammography. Both models were used to study the influence of some parameters, such as breast characteristics (thickness and composition) and incident spectra (kVp and target-filter combination) on the subject contrast of a nodule and on the normalized average glandular dose. From the subject contrast results, detection limits of nodules were also determined. Our results are in good agreement with those reported by other authors, who had used Monte Carlo simulation, showing the robustness of our semi-analytical method.

  13. Trinidadian capitalism

    Directory of Open Access Journals (Sweden)

    Kevin A. Yelvington

    1999-07-01

    Full Text Available [First paragraph] Capitalism: An Ethnographic Approach. DANIEL MILLER. Oxford: Berg, 1997. x + 357 pp. (Cloth £39.00, Paper £17.99 Women, Labour and Politics in Trinidad and Tobago: A History. RHODA E. REDDOCK. London: Zed, 1994. vi + 346 pp. (Cloth £39.95, Paper £15.95 Despite the underdeveloped state of the scholarship on its admittedly short sugar plantation slavery period, we now have a corpus of studies on various aspects of capitalism in Trinidad - from its historical advent (Sebastien 1978 to its twentieth-century manifestation in the petroleum sector (Seers 1964; Sandoval 1983, and from the ethnic structure of labor markets (Camejo 1971; Harewood 1971 and the role of capitalism in racial/ethnic inequality (Henry 1993; Coppin & Olsen 1998 to the way ethnicity affects business, big (Button 1981; Parris 1985; Centre for Ethnic Studies 1993 and small (Ryan & Barclay 1992; Griffith 1997, and the way ethnicity and gender are used in class recruitment (Yelvington 1995. There are also a number of fine working-class histories (e.g., Rennie 1973; Ramdin 1982; Basdeo 1983 and important works on the labor riots and strikes and the nature of the colonial state during the crises of the 1930s (e.g., Thomas 1987; Singh 1994. The two books under review here complement the works mentioned above, and they complement each other as well: Reddock's deals with the way capitalism up to the mid-century was buttressed by colonial politics, and explores how this formation engendered certain kinds of political responses, while Miller approaches capitalism through the assumption that fundamental changes in the post-Oil Boom period (ca. 1973-80 brought about considerable autonomy between production and consumption that can and should now be read through an analysis of the cultural circulation of images and commodities in the society. These books are both noteworthy because they engage in explicit theorizing on what capitalism was and is, and what it did and

  14. Instrumental Capital

    Directory of Open Access Journals (Sweden)

    Gabriel Valerio

    2007-07-01

    Full Text Available During the history of human kind, since our first ancestors, tools have represented a mean to reach objectives which might otherwise seemed impossibles. In the called New Economy, where tangibles assets appear to be losing the role as the core element to produce value versus knowledge, tools have kept aside man in his dairy work. In this article, the author's objective is to describe, in a simple manner, the importance of managing the organization's group of tools or instruments (Instrumental Capital. The characteristic conditions of this New Economy, the way Knowledge Management deals with these new conditions and the sub-processes that provide support to the management of Instrumental Capital are described.

  15. Contagious Capitalism

    OpenAIRE

    Peter T. Leeson; Russell S. Sobel

    2006-01-01

    Is capitalism contagious? Since WWI, global foreign policy has treated economic freedom/repression like a virus that spreads between countries. Most recently, the ?domino theory? of freedom has played prominently in U.S. foreign policy toward Asia, Latin America, and the Caribbean during the Cold War, and the Middle East during the War on Terror. This paper investigates the spread of economic freedom between nations. Our analysis considers two potential channels of this spread: geography and ...

  16. Filamentous Trichomic Prokaryotes in Carbonaceous Meteorites: Indigenous Microfossils, Minerals, or Modern Bio-Contaminants?

    Science.gov (United States)

    Hoover, Richard B.; Rozanov, Alexei Yu.

    2011-01-01

    Large complex filaments have been detected in freshly fractured interior surfaces of a variety of carbonaceous meteorites. Many exhibit the detailed morphological and morphometric characteristics of known filamentous trichomic prokaryotic microorganisms. In this paper we review prior studies of filamentous microstructures encountered in the meteorites along with the elemental compositions and characteristics of the, fibrous evaporite minerals and filamentous cyanobacteria and homologous trichomic sulfur bacteria. The meteorite images and elemental compositions will compared with data obtained with the same instruments for abiotic microstructures and living and fossil microorganisms in order to evaluate the relative merits of the alternate hypotheses that have been advanced to explain the nature and characteristics of the meteorite filaments. The possibiility that the filaments found in the meteorites may be comprise modern bio-contaminants will be evaluated in light of their observed elemental compositions and data by other researchers on the detection of indigenous complex organic biosignatures, and extraterrestrial amino acids and nucleobases found in the Murchison CM2 and the Orgueil CI1 carbonaceous meteorites.

  17. Role of allelochemicals and trichome density in the resistance of tomato to whitefly Papel de aleloquímicos e densidade de tricomas na resistência de tomateiro à mosca-branca

    Directory of Open Access Journals (Sweden)

    Irã Pinheiro Neiva

    2013-02-01

    Full Text Available In Brazil, the tomato is cultivated in almost all geographic regions even though its yield is significantly reduced by pests and diseases. Among these pests and diseases, whitefly is a major problem that causes direct and indirect damage due to its role in transmission of geminiviruses. The aim of the present study was to compare the degree of resistance to the silverleaf whitefly of tomato plant lines rich in acyl sugars (AS, zingiberene (ZGB, and 2-tridecanone (2-TD and to establish whether selection for strains with higher densities of glandular trichomes promotes sufficient resistance to this insect pest. The investigated lines were developed by performing back-crossings in tomato (Solanum lycopersicum from the interspecific crossing of S. lycopersicum x S. habrochaites var. glabratum 'PI 134417'. Lines rich in AS, ZGB, and 2-TD were tested for their levels of resistance to B. tabaci biotype B. Two tomato plant lines (TOM-584 and TOM-679 with normal AS levels and one wild specimen (PI 134417 with high 2-TD content were used as controls. TOM-687, ZGB-703, and TOM-622 were less preferred by B. tabaci for oviposition, and nymphs exhibited a poorer survival rate on those plant lines than on the susceptible controls, TOM-584 and TOM-679. Allelochemical-rich lines exhibited pest resistance, whereas the controls did not, and the allelochemical-rich lines did not differ significantly from each other in the level of resistance. The results show that the development of tomato plant lines rich in 2-TD, ZGB and AS is an effective option for indirect selection for resistance to B. tabaci biotype B. All lines selected based on high trichome density except for BPX-365F-751-05-01-03 exhibited fewer nymphs than the susceptible controls, indicating that selection for more glandular trichomes was generally effective in promoting increased resistance to the silverleaf white flay.No Brasil, o tomate é cultivado em praticamente todas as regiões, embora seu

  18. Expression of nucleophosmin in glandular epithelium of non-pregnant human endometrium during the menstrual cycle

    Institute of Scientific and Technical Information of China (English)

    KUANG Ye; XU Peng; WEN Hai-xia; KONG Xian-chao; GUAN Li-li; LI Pei-ling

    2011-01-01

    Background Nucleophosmin plays a critical role in embryonic development. This study aimed to examine the expression pattern of nucleophosmin in glandular epithelium of human endometrium during the menstrual cycle.Methods Endometrial tissues used for this study were obtained from 46 non-pregnant patients who underwent hysterectomy which had been performed to treat benign diseases. Nucleophosmin expression was assessed by in situ hybridization and immunohistochemistry.Results At the early-, mid- and late-proliferative phase, nucleophosmin mRNA was highly expressed in glandular epithelium of human endometrium. At the secretory phase, the expression of nucleophosmin mRNA was reduced in glandular epithelium in early-secretory phase, and the expression in mid- and late-secretory phases was not detected.Similarly, nucleophosmin protein was strongly expressed in endometrial glands throughout the proliferative phase, but was gradually reduced during secretory phase.Conclusion Nucleophosmin mRNA and protein are expressed in glandular epithelium of human endometrium throughout the menstrual cycle.

  19. Method for the evaluation of a average glandular dose in mammography

    International Nuclear Information System (INIS)

    This paper concerns a method for accurate evaluation of average glandular dose (AGD) in mammography. At different energies, the interactions of photons with tissue are not uniform. Thus, optimal accuracy in the estimation of AGD is achievable when the evaluation is carried out using the normalized glandular dose values, g(x,E), that are determined for each (monoenergetic) x-ray photon energy, E, compressed breast thickness (CBT), x, breast glandular composition, and data on photon energy distribution of the exact x-ray beam used in breast imaging. A generalized model for the values of g(x,E) that is for any arbitrary CBT ranging from 2 to 9 cm (with values that are not whole numbers inclusive, say, 4.2 cm) was developed. Along with other dosimetry formulations, this was integrated into a computer software program, GDOSE.FOR, that was developed for the evaluation of AGD received from any x-ray tube/equipment (irrespective of target-filter combination) of up to 50 kVp. Results are presented which show that the implementation of GDOSE.FOR yields values of normalized glandular dose that are in good agreement with values obtained from methodologies reported earlier in the literature. With the availability of a portable device for real-time acquisition of spectra, the model and computer software reported in this work provide for the routine evaluation of AGD received by a specific woman of known age and CBT

  20. Determination of average glandular dose with modern mammography units for two large groups of patients

    International Nuclear Information System (INIS)

    Until recently, for mammography Mo anode - Mo filter x-ray tube assemblies were almost exclusively used. Modern mammography units provide the possibility to employ a variety of anode - filter combinations with the aim of adapting the x-ray spectrum to compressed breast thickness and composition. The present contribution provides information on the radiation exposure of two large groups of patients (one of 1678 and one of 945 women) who were mammographed with modern x-ray equipment, and on the dosimetry necessary for the evaluation. For dosimetric purposes spectral information is essential. X-ray spectra have been determined for various anode-filter combinations from measurements with a Ge detector. Based on these spectra, conversion factors from air kerma free in air to average glandular dose (g actors) have been calculated for different anode-filter combinations, compressed breast thickness ranging from 2 to 9 cm and breast compositions varying from 0 to 100% glandular tissue. Determinations of various quantities, including entrance surface air kerma (ESAK), tube output, tube loading (TL), fraction of glandular tissue (FGL) and compressed breast thickness, were made during actual mammography. Average glandular dose (AGD) as determined using g factors corrected for tissue composition as well as g values for standard breast composition, i.e. 50% adipose tissue and 50% glandular tissue by mass. It is shown that, on average, the influence of the actual breast composition causes variations of the order of about 15%. For group 1 and group 2, the mean values of average glandular dose (using g actors corrected for tissue composition) were 1.59 and 2.07 mGy respectively. The number of exposures per woman was on average 3.4 and 3.6 respectively. The mean value of compressed breast thickness was 55.9 and 50.8 m respectively. The mean age of group 1 was 53.6 years (for group 2 the age as not recorded). The fraction by mass of glandular tissue FGL decreases with increasing

  1. RNA-seq discovery, functional characterization, and comparison of sesquiterpene synthases from Solanum lycopersicum and Solanum habrochaites trichomes

    NARCIS (Netherlands)

    P.M. Bleeker; E.A. Spyropoulou; P.J. Diergaarde; P. Volpin; M.T.J. de Both; P. Zerbe; J. Bohlmann; V. Falara; Y. Matsuba; E. Pichersky; M.A. Haring; R.C. Schuurink

    2011-01-01

    Solanum lycopersicum and Solanum habrochaites (f. typicum) accession PI127826 emit a variety of sesquiterpenes. To identify terpene synthases involved in the production of these volatile sesquiterpenes, we used massive parallel pyrosequencing (RNA-seq) to obtain the transcriptome of the stem trichom

  2. Terrific Trichomes (and Other Specialised Cells) in African Violets: How to Get a Lot from One Plant in the Classroom

    Science.gov (United States)

    Cottrell, Vicki M.

    2013-01-01

    African violet (genus "Saintpaulia") was identified as a particularly suitable genus for the study of specialised plant cells in the classroom using microscopes. The techniques described here involve simple preparation without staining. The cells and structures that can be investigated include: trichomes (hairs); stomata; guard cells and…

  3. Estimation of the average glandular dose on a team of tomosynthesis; Estimacion de la dosis glandular media en un equipo de tomosintesis

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Martinez, L. M. R.; Sanchez Jimenez, J.; Pizarro trigo, F.

    2013-07-01

    Seeking to improve the information that gives us an image of mammography the manufacturers have implemented tomosynthesis. With this method of acquisition and reconstruction of image we went from having a 2D to a 3D image image, in such a way that it reduces or eliminates the effect of overlap of tissues. The estimate of the dose, which is always a fundamental parameter in the control of quality of radiology equipment, is more in the case of mammography by the radiosensitivity of this body and the frequency of their use. The objective of this work is the determination of the mean in a team glandular dose of with tomosynthesis mammography. (Author)

  4. Monte Carlo simulation for the estimation of the glandular breast dose for a digital breast tomosynthesis system

    International Nuclear Information System (INIS)

    Digital breast tomosynthesis (DBT) is a screening and diagnostic modality that acquires images of the breast at multiple angles during a short scan. The Selenia Dimensions (Hologic, Bedford, Mass) DBT system can perform both full-field digital mammography and DBT. The system acquires 15 projections over a 15 deg. angular range (from -7.5 deg. to +7.5 deg.). An important factor in determining the optimal imaging technique for breast tomosynthesis is the radiation dose. In breast imaging, the radiation dose of concern is that deposited in the glandular tissue of the breast because this is the tissue that has a risk of developing cancer. The concept of the normalised mean glandular dose (DgN) has been introduced as the metric for the dose in breast imaging. The DgN is difficult to measure. The Monte Carlo techniques offer an alternative method for a realistic estimation of the radiation dose. The purpose of this work was to use the Monte Carlo code MCNPX technique to generate monoenergetic glandular dose data for estimating the breast tissue dose in tomosynthesis for arbitrary spectra as well as to observe the deposited radiation dose by projection on the glandular portion of the breast in a Selenia Dimensions DBT system. A Monte Carlo simulation of the system was developed to compute the DgN in a craniocaudal view. Monoenergetic X-ray beams from 10 to 49 keV in 1-keV increments were used. The simulation utilised the assumption of a homogeneous breast composition and three compositions (0 % glandular, 50 % glandular and 100 % glandular). The glandular and adipose tissue compositions were specified according ICRU Report 44. A skin layer of 4 mm was assumed to encapsulate the breast on all surfaces. The breast size was varied using the chest wall-to-nipple distance (CND) and compressed breast thickness (t). In this work, the authors assumed a CND of 5 cm and the thicknesses ranged from 2 to 8 cm, in steps of 2 cm. The fractional energy absorption increases (up to 44

  5. Flexible Capitalism

    DEFF Research Database (Denmark)

    Approaching “work” as at heart a practice of exchange, this volume explores sociality in work environments marked by the kind of structural changes that have come to define contemporary “flexible” capitalism. It introduces anthropological exchange theory to a wider readership, and shows how the...... perspective offers new ways to enquire about the flexible capitalism’s social dimensions. The essays contribute to a trans-disciplinary scholarship on contemporary economic practice and change by documenting how, across diverse settings, “gift-like” socialities proliferate, and even sustain the intensified...... flexible commoditization that more commonly is touted as tearing social relations apart. By interrogating a keenly debated contemporary work regime through an approach to sociality rooted in a rich and distinct anthropological legacy, the volume also makes a novel contribution to the anthropological...

  6. Understanding Capitalism

    DEFF Research Database (Denmark)

    du Gay, Paul; Morgan, Glenn

    2013-01-01

    they are to be sustained. Such logics are stabilized to the degree that they can pass the tests which they set themselves. The chapter shows how the projective city has increasingly failed these tests. It has instead created a privileged group of ‘mobile citizens’ working with mobile, global capital in...... ways that increasingly depend on a static, immobile group who are poorly paid, whose employment rights have been undermined and whose political voice is increasingly ignored. The chapter shows how Boltanski's pragmatist approach to critique as emergent from the experience of the actors themselves...... rather than being imposed by the analyst provides the basis for an understanding of how social and artistic critiques emerge. Whilst recognizing that New Spirits inevitably bears the marks of its origins in the particular context of France in the late 1990s, the chapter argues that there are key aspects...

  7. Evaluation of average glandular dose in digital and conventional systems of the mammography; Avaliacao da dose glandular media em sistemas digitais e convencionais de mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Aline C.S.; Barros, Vinicius S.M.; Khoury, Hellen J., E-mail: alinecx90@gmail.com, E-mail: vsmdbarros@gmail.com, E-mail: hjkhoury@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Mello, Francisca A. de, E-mail: francissamello@yahoo.com.br [Hospital das Clinicas do Recife (HCR/UFPE), PE (Brazil)

    2014-07-01

    Mammography is currently the most effective method of diagnosis and detection of breast pathologies. The main interest in this kid of exam comes from the high incidence rate of breast cancer and necessity of high quality images for accurate diagnosis. Digital mammography systems have several advantages compared to conventional systems, however the use of digital imaging systems is not always integrated to an image acquisition protocol. Therefore, it is questionable if digital systems truly reduce the dose received by the patient, because many times is introduced in the clinics without optimization of the image acquisition protocols. The aim of this study is to estimate the value of incident air Kerma and average glandular dose (AGD) in patients undergoing conventional and digital mammography systems in Recife. This study was conducted with 650 patients in three hospitals. The value of incident air Kerma was estimated from the measurement of the yield of equipment and irradiation parameters used for each patient. From these results and using the methodology proposed by Dance et al. the value of the average glandular dose was calculated. The results obtained show that the lowest value of AGD was found with conventional screen-film system, indicating that the parameters for image acquisition with digital systems are not optimized. It was also observed that the institutions with digital systems use lower breast compression values than the conventional. (author)

  8. Placing social capital

    OpenAIRE

    G Mohan; J Mohan

    2002-01-01

    Metadata only record This paper looks at the relevance and contributions of social capital analysis to human geography and vise versa. The authors start by defining social capital and clarifying and distinguishing concepts, and critiques of Putnam's work. Social capital is simultaneously an economic, sociological, political, and geographical concept, but it must be distinguished from human capital, cultural capital, and networks. Social capital can be relevant to human geographers because ...

  9. Comparison of mean glandular dose values provided by a digital breast tomosynthesis system in Brazil

    International Nuclear Information System (INIS)

    Studies are needed to determine the radiation dose of patients that are undergoing Digital breast tomosynthesis (DBT) procedures. Mean glandular dose (DG) values were derived from the incident air kerma (Ki) measurements and tabulated conversion coefficients. Ki values were obtained through an ionization chamber positioned in a Hologic Selenia Dimensions system using appropriate exposure parameters. This work contributes to determine the reliable radiation dose received by the patients and compare DG values provided by this DBT system images. - Highlights: • Studies are needed to determine the dose of tomosynthesis (DBT) procedures. • Mean glandular dose (DG) results derived from the incident air kerma (Ki). • Ki values were obtained through an ionization chamber. • A DBT system was used with appropriate exposure parameters. • This work contributes to compare DG values provided by this DBT system images

  10. Histological Correlation of Glandular Abnormalities in Cervical Liquid-Based Cytology

    Directory of Open Access Journals (Sweden)

    Yosuke Kawakami

    2011-01-01

    Full Text Available Conventional Papanicolaou smear method is still commonly used for cervical cancer screening in Japan, despite the liquid-based cytology (LBC that has become a global tendency in the world recently. One of the obstacles in the way of popularization of this method seems to be the confusion as to diagnosis upon cervical glandular lesions. We performed comparison study between LBC and conventional Papanicolaou smear about cytological diagnosis using split-sample method in 4522 patients. In 13 cases analyses, which were reported with either AGC or adenocarcinoma by either method, LBC tends to be milder than that by conventional smear, however, the credibility of LBC is considered to be near to that of conventional smear with regard to screening for glandular abnormalities. These results indicate that cervical cancer screening should shift to LBC under the enough experience and appropriate dealing with the cytological diagnosis.

  11. The Study of Mean Glandular Dose in Mammography in Yazd and the Factors Affecting It

    Directory of Open Access Journals (Sweden)

    F. Bouzarjomehri

    2006-08-01

    Full Text Available Backgrounds/Objective: The objective of this study was to determine the mean glandular dose (MGD resulting from mammography examinations in Yazd, southeastern Iran and to identify the factors affecting it. Patients and Methods: This survey was conducted during May to December 2005 to estimate the MGD for women undergoing mammography and to report the distribution of dose, com-pressed breast thickness, glandular tissue content, and mammography technique used. The clinical data were collected from 946 mammograms taken from 246 women who were referred to four mammography centers. The mammography instruments in these centers were four modern units with a molybdenum anode and either molybdenum or rhodium filter. The exposure conditions of each mammogram were recorded. The breast glandular content of each mammogram was estimated by a radiologist. The MGD was calculated based on measuring the normalized entrance skin dose (ESD in air, Half Value Layer (HVL, kVp, mAs, breast thickness and glandular content. HVL, kVp and ESD were measured by a solid-state detector. The analytical method of Sobol et al. was used for calculation of MGD. Results: The mean±SD MGD per film was 1.2±0.6 mGy for craniocaudal and 1.63±0.9 mGy for mediolateral oblique views. The mean±SD MGD per woman was 5.57±3.1 mGy. A positive correlation was found between the beam HVL with MGD (r=0.38 and the breast thickness with MGD (r=0.5. Conclusion: The mean±SD MGD per film of 1.42±0.8 mGy in present study was lower than most of similar reports. However, the mean MGD per woman was higher than that in other studies.

  12. Thymomas with prominent glandular differentiation: a clinicopathologic and immunohistochemical study of 12 cases.

    Science.gov (United States)

    Weissferdt, Annikka; Moran, Cesar A

    2013-08-01

    Twelve cases of thymomas with prominent glandular differentiation are presented. The patients were 7 men and 5 women aged between 45 and 68 years (average, 56.5 years). Clinically, the patients presented with nonspecific symptoms of chest pain, cough, and fatigue. None of the patients had a history of myasthenia gravis or other autoimmune syndrome. Thymectomy was performed in all patients. The tumor size ranged from 4 to 7 cm in greatest diameter. Macroscopically, the tumors were described as firm and light tan without areas of necrosis, hemorrhage, or cystic change. Histologically, 7 tumors were classified as spindle cell (World Health Organization type A), 2 as mixed spindle cell and conventional (A+B1), 2 as conventional (B1), and 1 as atypical thymoma (B3). In 4 cases, the tumors showed invasion into periadipose thymic tissue. All cases showed the typical growth patterns of their particular subtypes. In addition, a distinct glandular component was present in all cases showing mucinous differentiation in 4 of them. Immunohistochemical studies showed tumor cells positive for CAM5.2, cytokeratin 5/6, and Pax8 and negative for carcinoembryonic antigen, thyroid transcription factor 1, and epithelial membrane antigen. Calretinin showed focal weak staining in the nonmucinous glandular components in 3 cases. Follow-up information obtained in 8 patients showed that all were alive and well in a period ranging from 2 to 5 years. The possibility of a glandular component in thymomas should be kept in mind in the assessment of mediastinoscopic biopsies to avoid misdiagnosis for other neoplasms that may require different treatment modalities. PMID:23528863

  13. Analysis of patient exposure dose for mammography. Estimation of average glandular dose in 1998 questionnaire

    International Nuclear Information System (INIS)

    Recently, patient exposure dose for mammography are varied because of a great demand for mammography, which non-palpable lesion can be detected, diffusion of special X-ray equipment, progress of CR and enlightenment or study on mammography in Japanese society of radiological technology. Therefore, the newest patient exposure dose obtained from '98 questionnaire carried out to the whole country in Japan was investigated. Furthermore, the average glandular dose based on '98 was compared with that of '93. The average glandular dose can be calculated from the product of the breast entrance skin exposure and DgN (the average glandular dose per unit entrance skin exposure). The breast entrance skin dose was estimated from the dose of 782 institutions in '98, which was calculated from data measured at 51 institutions in Tokai and Hokuriku area. DgN was used published table of 50% adipose-50% glandular breast composition and 4.2 cm breast thickness corresponding to measured half-value layer (HVL) on each tube voltages. Then, patient exposure dose for mammography was estimated from exposure condition (tube voltage, mAs value) obtained '98 questionnaire. The dose in '98 estimated 1.422 mGy was reduced that compared with in '93 estimated 1.610 mGy. The dose of '98 without grid was reduced about 30% of '93. The dose of 98 with grid was not any reduced than the dose of '93. However, the number of institution of '98 with grid was about 2.8 times than '93. The patient exposure dose for mammography was reduced approximately 10% during 5 years. There are probability that mammography with grid for guidance level will be 1.5 mGy. (author)

  14. Histological Correlation of Glandular Abnormalities in Cervical Liquid-Based Cytology

    OpenAIRE

    Yosuke Kawakami; Tamaki Toda; Toshinao Nishimura; Junichi Sakane; Kazuya Kuraoka; Kazuhiro Takehara; Tomoya Mizunoe; Kiyomi Taniyama

    2011-01-01

    Conventional Papanicolaou smear method is still commonly used for cervical cancer screening in Japan, despite the liquid-based cytology (LBC) that has become a global tendency in the world recently. One of the obstacles in the way of popularization of this method seems to be the confusion as to diagnosis upon cervical glandular lesions. We performed comparison study between LBC and conventional Papanicolaou smear about cytological diagnosis using split-sample method in 4522 patients. In 13 ca...

  15. Long acting β2-agonist and corticosteroid restore airway glandular cell function altered by bacterial supernatant

    Directory of Open Access Journals (Sweden)

    Nawrocki-Raby Béatrice

    2010-01-01

    Full Text Available Abstract Background Staphylococcus aureus releases virulence factors (VF that may impair the innate protective functions of airway cells. The aim of this study was to determine whether a long-acting β2 adrenergic receptor agonist (salmeterol hydroxynaphthoate, Sal combined with a corticosteroid (fluticasone propionate, FP was able to regulate ion content and cytokine expression by airway glandular cells after exposure to S. aureus supernatant. Methods A human airway glandular cell line was incubated with S. aureus supernatant for 1 h and then treated with the combination Sal/FP for 4 h. The expression of actin and CFTR proteins was analyzed by immunofluorescence. Videomicroscopy was used to evaluate chloride secretion and X-ray microanalysis to measure the intracellular ion and water content. The pro-inflammatory cytokine expression was assessed by RT-PCR and ELISA. Results When the cells were incubated with S. aureus supernatant and then with Sal/FP, the cellular localisation of CFTR was apical compared to the cytoplasmic localisation in cells incubated with S. aureus supernatant alone. The incubation of airway epithelial cells with S. aureus supernatant reduced by 66% the chloride efflux that was fully restored by Sal/FP treatment. We also observed that Sal/FP treatment induced the restoration of ion (Cl and S and water content within the intracellular secretory granules of airway glandular cells and reduced the bacterial supernatant-dependent increase of pro-inflammatory cytokines IL8 and TNFα. Conclusions Our results demonstrate that treatment with the combination of a corticosteroid and a long-acting β2 adrenergic receptor agonist after bacterial infection restores the airway glandular cell function. Abnormal mucus induced by defective ion transport during pulmonary infection could benefit from treatment with a combination of β2 adrenergic receptor agonist and glucocorticoid.

  16. Mayolenes: labile defensive lipids from the glandular hairs of a caterpillar (Pieris rapae).

    Science.gov (United States)

    Smedley, Scott R; Schroeder, Frank C; Weibel, Douglas B; Meinwald, Jerrold; Lafleur, Katie A; Renwick, J Alan; Rutowski, Ronald; Eisner, Thomas

    2002-05-14

    Larvae of the European cabbage butterfly, Pieris rapae (Pieridae), are beset with glandular hairs, bearing droplets of a clear oily secretion at their tip. The fluid consists primarily of a series of chemically labile, unsaturated lipids, the mayolenes, which are derived from 11-hydroxylinolenic acid. In bioassays with the ant Crematogaster lineolata, the secretion was shown to be potently deterrent, indicating that the fluid plays a defensive role in nature. PMID:11997469

  17. A computational approach to resolve cell level contributions to early glandular epithelial cancer progression

    OpenAIRE

    Park Sunwoo; Mostov Keith; Debnath Jayanta; Kim Sean HJ; Hunt C Anthony

    2009-01-01

    Abstract Background Three-dimensional (3D) embedded cell cultures provide an appropriate physiological environment to reconstruct features of early glandular epithelial cancer. Although these are orders of magnitude simpler than tissues, they too are complex systems that have proven challenging to understand. We used agent-based, discrete event simulation modeling methods to build working hypotheses of mechanisms of epithelial 3D culture phenotype and early cancer progression. Starting with a...

  18. Glandular odontogenic cyst associated with ameloblastoma occupying maxillary sinus: A rare case report

    Directory of Open Access Journals (Sweden)

    Riaz Abdulla

    2016-01-01

    Full Text Available The glandular odontogenic cyst (GOC is a rare entity with around 111 cases available in the literature. The occurrence of GOC with ameloblastoma as a collision tumor is rarest, and such a case poses problems in the form of diagnostic dilemma and management. The present case report describes and discusses a rare case of GOC with ameloblastomatous component occurring in right maxilla of a 54-year-old male patient with a chief complaint of painful swelling.

  19. Epithelial cell proliferation and glandular atrophy in lymphocytic gastritis: Effect of H pylori treatment

    OpenAIRE

    Mäkinen, Johanna M; Niemelä, Seppo; Kerola, Tuomo; Lehtola, Juhani; Karttunen, Tuomo J

    2003-01-01

    AIM: Lymphocytic gastritis is commonly associated with Helicobacter pylori infection. The presence of glandular atrophy and foveolar hyperplasia in lymphocytic gastritis suggests abnormalities in cell proliferation and differentiation, forming a potential link with the suspected association with gastric cancer. Our aim was to compare epithelial proliferation and morphology in H pylori associated lymphocytic gastritis and H pylori gastritis without features of lymphocytic gastritis, and to eva...

  20. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation

    International Nuclear Information System (INIS)

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed. (authors)

  1. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation.

    Science.gov (United States)

    Marques, T; Ribeiro, A; Di Maria, S; Belchior, A; Cardoso, J; Matela, N; Oliveira, N; Janeiro, L; Almeida, P; Vaz, P

    2015-07-01

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed. PMID:25836692

  2. Average glandular dose with amorphous silicon full-field digital mammography - clinical results

    International Nuclear Information System (INIS)

    Purpose: Determination of average glandular dose with a full-field digital mammography system using a flat-panel X-ray detector based on amorphous silicon technology for a large group of patients. Material and Methods: The patient group includes women who were examined in a 4-month period with the digital mammographic system Senographe 2000D. The number of women was 591 and the number of exposures was 1116; only cranio-caudal projections were considered. Various quantities, including entrance surface air kerma, tube loading, and compressed breast thickness, were determined during actual mammography. Average glandular dose was determined using conversion factors g for standard breast composition. Results: The mean average glandular dose was 1.51 mGy (0.66-4.05 mGy) for a single view. The mean compressed breast thickness was 55.7 mm. The mean age of patients was 55 years (34-81 years). Conclusion: The results demonstrate that full-field digital mammography with a flat-panel detector based on amorphous silicon needs about 25% less dose in comparison with conventional screen-film mammography. (orig.)

  3. Determination of a method for calculating mean glandular dose in conventional mammography exams

    International Nuclear Information System (INIS)

    We present the application of a numerical model to estimate the mean glandular dose for mammography.A General Electric mammography system, tube voltage of 20-35 kV with increments of 1 kV, tube current of 10-250 mAs, anode/filter combinations molybdenum/molybdenum was used. Over a period of two months, data from 162 scans with craniocaudal and mediolateral oblique projections in both breasts were recorded. The thickness of the compressed breast ranged from 2.5 to 6.5 cm. The mean glandular dose for each craniocaudal projection ranged from 0.4 to 0.7 mGy for a thickness of 2.5 cm and 1.9 to 2.8 mGy for a thickness of 6.5 cm. All average values of mean glandular dose estimated by cranio-caudal projection were found to be below the international reference dose value of 3 mGy recommended by the American College of Radiology

  4. Analysis of QTLs for the Trichome Density on the Upper and Downer Surface of Leaf Blade in Soybean [Glycine max (L.) Merr.

    Institute of Scientific and Technical Information of China (English)

    DU Weijun; YU Deyue; FU Sanxiong

    2009-01-01

    Trichomes (plant hairs) are present on nearly all land plants and are known to play important roles in plant protection,specifically against insect herbivory,drought,and UV radiation.The identification of quantitative trait loci (QTL) associated with trichome density should help to interpret the molecular genetic mechanism of soybean trichome density.184 recombinant inbred lines (RILs),derived from a cross between soybean cultivars Kefeng 1 and Nannong 1138-2 were used as segregating population for evaluation of TDU (trichome density on the upper surface of leaf blade) and TDD (trichome density on the downer surface of leaf blade).A total of 15 QTL were detected on molecular linkage groups (MLG) A2,Dla,Dlb,E and H by composite interval mapping (CIM) and among all the QTL,qtuA2-1,qtuD 1a-1,qaK)lb-2,qtuH-2 qtuE-1,qtdD1b-2,and qtdH-2 were affirmed by multiple interval mapping (MIM).The contribution of phenotypic variance of qtuH-2 was 31.81 and 29.4% by CIM and MIM,respectively,suggesting it might be major gene Ps loci.Only 10 pairs of main QTL interactions for TDU were detected,explained a range of 0.2-5.1% of phenotypic variations for each pair for a total of 22.8%.The QTL on MLG D 1 b affecting trichome density were mapped near to Rsc-7 conditioning resistance to SMV (soybean mosaic virus).This study showed that the genetic mechanism of trichome density was the mixed major gene and polygene inheritance,and also suggested that the causal nature between trichome density and other agronomic traits.

  5. Calculation of absorbed glandular dose using a Fortran program based on Monte Carlo X-ray spectra in mammography

    International Nuclear Information System (INIS)

    Average glandular dose calculation in mammography with Mo-Rh target-filter and dose calculation for different situations is accurate and fast. Material and Methods: In this research, first of all, x-ray spectra of a Mo target bombarded by a 28 keV electron beam with and without a Rh filter were calculated using the MCNP code. Then, we used the Sobol-Wu parameters to write a FORTRAN code to calculate average glandular dose. Results: Average glandular dose variation was calculated against the voltage of the mammographic x-ray tube for d = 5 cm, HVL= 0.35 mm Al, and different value of g. Also, the results related to average glandular absorbed dose variation per unit roentgen radiation against the glandular fraction of breast tissue for kV = 28 and HVL = 0.400 mmAl and different values of d are presented. Finally, average glandular dose against d for g = 60% and three values of kV (23, 27,35 kV) with corresponding HVLs have been calculated. Discussion and Conclusion: The absorbed dose computational program is accurate, complete, fast and user friendly. This program can be used for optimization of exposure dose in mammography. Also, the results of this research are in good agreement with the computational results of others.

  6. National accounting and capital

    OpenAIRE

    John M. Hartwick

    2012-01-01

    National Accounting and Capital presents definitive solutions to current problems in national accounting practice. Professor Hartwick deals expertly with problems in accounting natural capital, financial capital and skills capital and communicates his solutions in specially designed national accounting tables or matrices.

  7. RNA-seq discovery, functional characterization, and comparison of sesquiterpene synthases from Solanum lycopersicum and Solanum habrochaites trichomes

    OpenAIRE

    Bleeker, Petra M.; Spyropoulou, Eleni A; Diergaarde, Paul J.; Volpin, Hanne; De Both, Michiel T. J.; Zerbe, Philipp; Bohlmann, Joerg; Falara, Vasiliki; Matsuba, Yuki; Pichersky, Eran; Haring, Michel A.; Schuurink, Robert C.

    2011-01-01

    Solanum lycopersicum and Solanum habrochaites (f. typicum) accession PI127826 emit a variety of sesquiterpenes. To identify terpene synthases involved in the production of these volatile sesquiterpenes, we used massive parallel pyrosequencing (RNA-seq) to obtain the transcriptome of the stem trichomes from these plants. This approach resulted initially in the discovery of six sesquiterpene synthase cDNAs from S. lycopersicum and five from S. habrochaites. Searches of other databases and the S...

  8. Capitalism and human flourishing?

    OpenAIRE

    Gasper, D.R.

    2009-01-01

    What interpretation of human flourishing, what ideas of value does capitalism in practice embody and promote? To address this question the paper clarifies first that "capitalism" must be understood as more than merely a system of private property and markets. It contains "the prerogative of capital", in which surplus remains with the owners of capital, and "the perspective of capital", in which hired work is defined as a cost. The question must also be distinguished from more conventional one...

  9. Capitalism and justification

    OpenAIRE

    Birešev Ana

    2009-01-01

    Weber's thesis that the spirit of capitalism was preexistent to the rise of capitalism itself inspired many sociologist to search for the cultural background of contemporary forms of capitalism. In this paper, the author focuses on and makes comparisons of three approaches of such kind. The one approach draws from Luc Boltanski and Ève Chiapello who examine the development of 'new spirit of capitalism' by focusing on the interrelation of two macroactors - capitalism and critique; the other on...

  10. Cistite glandular evoluindo com uropatia obstrutiva Cystitis glandularis evolving with obstructive uropathy

    Directory of Open Access Journals (Sweden)

    Humberto Elias Lopes

    2009-12-01

    Full Text Available INTRODUÇÃO: Cistite glandular é um processo proliferativo benigno e infrequente da mucosa vesical, caracterizado por proliferação do epitélio e, em alguns casos, formação de glândulas intestinais. Alterações metaplásicas na cistite glandular são bem documentadas na literatura, embora sua etiologia não seja totalmente esclarecida. RELATO DO CASO: Relatamos um caso de cistite glandular em um paciente de 55 anos, apresentando sintomas miccionais irritativos e obstrutivos persistentes sem resposta à terapia com alfabloqueadores. Ultrassonografia evidenciou lesão vegetante no trígono vesical e o paciente foi submetido à ressecção endoscópica por duas vezes e evoluiu com ureterohidronefrose bilateral. Dado o extenso acometimento vesical e a persistência dos sintomas, o paciente foi submetido a cistoprostatectomia e neobexiga ileal com boa evolução pós-operatória. DISCUSSÃO: Há duas formas de cistite glandular: típica e intestinal. A forma típica é a mais comum e a intestinal é marcada pela produção de mucina, mais frequentemente associada ao adenocarcinoma de bexiga. A maioria dos casos de cistite glandular é assintomática, sendo que os pacientes sintomáticos normalmente apresentam hematúria, sintomas urinários irritativos e típicos de cistite crônica. Há controvérsias sobre o tratamento precoce agressivo, sendo que vários estudos propõem a ressecção transuretral e o acompanhamento com biópsias.INTRODUCTION: Cystitis glandularis is a rare, benign, proliferative process of the mucosa of the urinary bladder characterized by epithelial proliferation and occasional formation of intestinal glands. Although its etiology is unknown, cystitis glandularis has been associated with chronic stimulation of the mucosa of the urinary bladder due to urinary tract infection, obstruction, and indwelling catheters, which may lead to overproductive changes in mucosal cells and glandular metaplasia of transitional epithelial

  11. Preliminary results of the average glandular dose to the breast with TLDS measure is computed as the conversion factors; Resultados preliminares da dose glandular media na mama medida com TLDS e calculada atraves de fatores de conversao

    Energy Technology Data Exchange (ETDEWEB)

    Sardo, Luiz T.L.; Almeida, Claudio D.; Coutinho, Celia M.C., E-mail: ltsardo@yahoo.com.br, E-mail: claudio@ird.gov.br, E-mail: celia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    At mammography exams there is a risk of a breast cancer induced from the absorbed dose by the glandular tissue. According to the National Institute of Cancer, INCA, breast cancer is the second type most frequent in the world and the most common among women, therefore the necessity of monitoring the mean glandular dose, D{sub G}. Measuring methods of D{sub G} were established by some authors. Among the established methods the method of Dance is one of the most known. In this study was utilized a measurement method realized with TL dosimeters inserted in a breast tissue equivalent phantom, BTE, with 46% of glandularity and exposed using Mo/Mo and Mo/Rh target/filter combination and 28kV. To ensure this measurement method the results were compared with a calculation method, used by Dance, of D{sub G} from the measurement of incident air kerma, K{sub i}, and conversion factors to consider mainly the beam quality, the compressed thickness and the glandularity of the breast. The results of the comparison of the D{sub G} measurement with the obtained dose by the method of Dance demonstrated that for the thickness of 4.0 and 6.0 cm the doses were consistent. For the thickness of 5.0 cm the difference was higher, indicating that the glandularity may influence, suggesting further investigation. (author)

  12. Capital disadvantage: America's failing capital investment system.

    Science.gov (United States)

    Porter, M E

    1992-01-01

    The U.S. system of allocating investment capital is failing, putting American companies at a serious disadvantage and threatening the long-term growth of the nation's economy. The problem, says Michael Porter, goes beyond the usual formulation of the issue: accusations of "short-termism" by U.S. managers, ineffective corporate governance by directors, or a high cost of capital. The problem involves the external capital allocation system by which capital is provided to companies, as well as the system by which companies allocate capital internally. America's system is marked by fluid capital and a financial focus. Other countries--notably Japan and Germany--have systems with dedicated capital and a focus on corporate position. In global competition, where investment increasingly determines a company's capacity to upgrade and innovate, the U.S. system does not measure up. These conclusions come out of a two-year research project sponsored by the Harvard Business School and the Council on Competitiveness. Porter recommends five far-reaching reforms to make the U.S. system superior to Japan's and Germany's: 1. Improve the present macroeconomic environment. 2. Expand true ownership throughout the system so that directors, managers, employees, and even customers and suppliers hold positions as owners. 3. Align the goals of capital providers, corporations, directors, managers, employees, customers, suppliers, and society. 4. Improve the information used in decision making. 5. Foster more productive modes of interaction and influence among capital providers, corporations, and business units. PMID:10121317

  13. Intangible Capital and Ramsey Capital Taxation (updated)

    OpenAIRE

    Juan Carlos Conesa; Begoña Domínguez

    2009-01-01

    The standard analysis of optimal fiscal policy in the neoclassical growth model, e.g. Chamley (1986) and Judd (1985), aggregates different types of assets into a unique capital good and all sorts of capital taxes into a unique capital tax. There, the optimal capital tax rate is very high in the short-run and zero in the long-run and, inevitably, time-inconsistent. This paper shows that this classic result does not hold in a more disaggregated framework. As proposed in McGrattan and Prescott (...

  14. Public Capital, Private Capital and Economic Growth

    OpenAIRE

    Alberto Bucci

    2012-01-01

    A growth model is presented in which productive government expenditure takes the form of a stock. Private and public capital interact with each other in two ways. The first is related to the specification of the aggregate production function (Cobb-Douglas vs. CES). The second has to do with the rates of investment in the two types of capital, and arises from the law of motion of public capital. The share of public capital devoted to output production can be exogenous or endogenous. In this fr...

  15. Human Capital a Part of Social Capital

    OpenAIRE

    Inna Fedoryshina

    2014-01-01

    The article considers the content and the structure of human capital. The term “human capital” is viewed as people’s abilities toparticipate in the production process in order to make use of their potential skills. A particular attention is paid to the meaning ofsocial capital and its role in the formation of human capital. It is proven that there is not much research on the connection betweenhuman and social capital. Human development index in Ukraine and 20 leading counties of the global ra...

  16. Effect of anode/filter combination on average glandular dose in mammography

    OpenAIRE

    Michal Biegala; Teresa Jakubowska; Karolina Markowska

    2015-01-01

    A comparative analysis of the mean glandular doses was conducted in 100 female patients who underwent screening mammography in 2011 and 2013. Siemens Mammomat Novation with the application of the W/Rh anode/filter combination was used in 2011, whereas in 2013 anode/filter combination was Mo/Mo or Mo/Rh. The functioning of mammography was checked and the effectiveness of the automatic exposure control (AEC) system was verified by measuring compensation of changes in the phantom thickness and m...

  17. Epithelial cell proliferation and glandular atrophy in lymphocytic gastritis: Effect of H pylori treatment

    Institute of Scientific and Technical Information of China (English)

    Johanna M. Makinen; Seppo Niemela; Tuomo Kerola; Juhani Lehtola; Tuomo J. Karttunen

    2003-01-01

    AIM: Lymphocytic gastritis is commonly ass ociated with Helicobacter pylori infection. The presence of glandular atrophy and foveolar hyperplasia in lymphocytic gastritis suggests abnormalities in cell proliferation and differentiation,forming a potential link with the suspected association with gastric cancer. Our aim was to compare epithelial cell proliferation and morphology in H pylori associated lymphocytic gastritis and H pylori gastritis without features of lymphocytic gastritis,and to evaluate the effect of H pylori treatment.METHODS: We studied 14 lymphocytic gastritis patients with H pylori infection. For controls, we selected 14 matched dyspeptic patients participating in another treatment trial whose H pylori infection had successfully been eradicated.Both groups were treated with a triple therapy and followed up with biopsies for 6-18 months (patients) or 3 months (controls). Blinded evaluation for histopathological features was carried out. To determine the cell proliferation index,the sections were labeled with Ki-67 antibody.RESULTS: Before treatment, lymphocytic gastritis was characterized by foveolar hyperplasia (P=0.001) and glandular atrophy in the body (P=0.008), and increased proliferation in both the body (P=0.001) and antrum (P=0.002). Proliferation correlated with foveolar hyperplasia and inflammation activity. After eradication therapy, the number of intraepithelial lymphocytes decreased in the body (P=0.004)and antrum (P=0.065), remaining higher than in controls (P<0.001). Simultaneously, the proliferation index decreased in the body from 0.38 to 0.15 (P=0.043), and in the antrum from 0.34 to 0.20 (P=0.069), the antral index still being higher in lymphocytic gastritis than in controls (P=0.010).Foveolar hyperplasia and glandular atrophy in the body improved (P=0.021), reaching the non-LG level.CONCLUSION: In lymphocytic gastritis, excessive epithelial cell proliferation is predominantly present in the body, where it associates with

  18. Estimation of the average glandular dose on a team of tomosynthesis

    International Nuclear Information System (INIS)

    Seeking to improve the information that gives us an image of mammography the manufacturers have implemented tomosynthesis. With this method of acquisition and reconstruction of image we went from having a 2D to a 3D image image, in such a way that it reduces or eliminates the effect of overlap of tissues. The estimate of the dose, which is always a fundamental parameter in the control of quality of radiology equipment, is more in the case of mammography by the radiosensitivity of this body and the frequency of their use. The objective of this work is the determination of the mean in a team glandular dose of with tomosynthesis mammography. (Author)

  19. Administration of trimethoprim-sulphadimidine does not improve healing of glandular gastric ulceration in horses receiving omeprazole: a randomised, blinded, clinical study

    OpenAIRE

    Sykes, Ben W; Sykes, Katja M; Hallowell, Gayle D

    2014-01-01

    Background Interest in Equine Gastric Ulcer Syndrome (EGUS) has recently increased in part due to a growing awareness of the differences between squamous and glandular disease. The pathophysiology and epidemiology of squamous and glandular disease are different and recently it has been shown that the response of glandular gastric ulceration to monotherapy with omeprazole is poor. Given these differences it has been recommended that specific treatment guidelines be formulated for equine glandu...

  20. Measurement of breast entrance exposure and mean glandular dose during screen-film mammography examination at our centre

    International Nuclear Information System (INIS)

    Radiation based imaging modalities have been of great benefit to mankind due to their ability to help in diagnosis. Mammography is recognized as the most optimized imaging modality for early detection of breast cancer. However there has been a growing concern among the general public, as well as the scientific and medical communities regarding the ill effect of radiation exposure from diagnostic X-ray examination. Therefore increased attention has recently been directed towards radiation dose to the patient. Several years ago the radiation dose received during mammography was measured as the entrance dose to the skin of the breast. Now, it is presumed that it is the breast glandular tissue that is at risk for developing cancer in future therefore measurement of mean glandular dose (MGD) is the quantity recommended by ICRP and European Protocol for performance assessment of the system. With optimization technique and continued quality assurance programme the breast dose can be kept at lower levels without sacrificing diagnostic value. Our objective intends to evaluate the Breast Entrance Exposure (BEE) and Mean Glandular Dose (MGD) received by the patients during mammography examination. According to the Mammography Quality Standard Act (MQSA, 2002), USA, the average glandular dose to an average (4.2 cm compressed) breast must not exceed 3 mGy per view for film-screen image receptors. The European protocol specifies the average glandular dose for a 4.5 cm thick breast typically less than 2.0 mGy

  1. Preliminary results of the average glandular dose to the breast with TLDS measure is computed as the conversion factors

    International Nuclear Information System (INIS)

    At mammography exams there is a risk of a breast cancer induced from the absorbed dose by the glandular tissue. According to the National Institute of Cancer, INCA, breast cancer is the second type most frequent in the world and the most common among women, therefore the necessity of monitoring the mean glandular dose, DG. Measuring methods of DG were established by some authors. Among the established methods the method of Dance is one of the most known. In this study was utilized a measurement method realized with TL dosimeters inserted in a breast tissue equivalent phantom, BTE, with 46% of glandularity and exposed using Mo/Mo and Mo/Rh target/filter combination and 28kV. To ensure this measurement method the results were compared with a calculation method, used by Dance, of DG from the measurement of incident air kerma, Ki, and conversion factors to consider mainly the beam quality, the compressed thickness and the glandularity of the breast. The results of the comparison of the DG measurement with the obtained dose by the method of Dance demonstrated that for the thickness of 4.0 and 6.0 cm the doses were consistent. For the thickness of 5.0 cm the difference was higher, indicating that the glandularity may influence, suggesting further investigation. (author)

  2. Financing working capital

    OpenAIRE

    Vasile Popengă; Mirela Popescu

    2002-01-01

    The paper presents some particularities regarding the following aspects: what is working capital; shows alternative net working capital financing strategies, ranging from the most to least risky; also some sources of short-term finance

  3. Triads of capital

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase

    Within current research on social capital, a gap exists between political history analyses at the macro level and classical, sociological analyses at the meso and micro levels. Following up on  earlier work, the main purpose of this paper is to mediate between the two conflicting stances...... represented by Putnam and Portes. The paper raises the following question: Is it possible to detect the historical driving forces behind the building of both beneficial and harmful social capital? Driving forces are defined as structural determinants, which change human organization at all levels. The...... hypothesis is that three forms of capital have the potential to act as driving forces: social capital, cultural capital and physical capital, the latter operationaliz­ed as buildings. A new concept, triad of capital, is introduced to analyze the interrelationship between these three forms of capital. A triad...

  4. Evaluation of average glandular dose in digital and conventional systems of the mammography

    International Nuclear Information System (INIS)

    Mammography is currently the most effective method of diagnosis and detection of breast pathologies. The main interest in this kid of exam comes from the high incidence rate of breast cancer and necessity of high quality images for accurate diagnosis. Digital mammography systems have several advantages compared to conventional systems, however the use of digital imaging systems is not always integrated to an image acquisition protocol. Therefore, it is questionable if digital systems truly reduce the dose received by the patient, because many times is introduced in the clinics without optimization of the image acquisition protocols. The aim of this study is to estimate the value of incident air Kerma and average glandular dose (AGD) in patients undergoing conventional and digital mammography systems in Recife. This study was conducted with 650 patients in three hospitals. The value of incident air Kerma was estimated from the measurement of the yield of equipment and irradiation parameters used for each patient. From these results and using the methodology proposed by Dance et al. the value of the average glandular dose was calculated. The results obtained show that the lowest value of AGD was found with conventional screen-film system, indicating that the parameters for image acquisition with digital systems are not optimized. It was also observed that the institutions with digital systems use lower breast compression values than the conventional. (author)

  5. Immunohistochemical evidence: testicular and scented glandular androgen synthesis in muskrats (Ondatra zibethicus during the breeding season

    Directory of Open Access Journals (Sweden)

    Q. Li

    2011-10-01

    Full Text Available In order to elucidate the relationship between androgens and the function of the muskrat (Ondatra zibethicus scented glands during the breeding season, we investigated immunolocalization of steroidogenic enzymes P450scc, 3βHSD and P450c17 in the muskrat testes and scented glands. Nine adult muskrats were obtained in March (n=3, May (n=3 and July (n=3 2010. Steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal P450scc, human placental 3βHSD and porcine testicular P450c17. Histologically, all types of spermatogenic cells including mature–phase spermatozoa in seminiferous tubules were observed in all testes. Glandular cells, interstitial cells, epithelial cells and excretory tubules were identified in scented glands during the breeding season. P450scc, 3βHSD and P450c17 were only identified in Leydig cells during the breeding season; P450scc and P450c17 were observed in glandular cells of scented glands, however, 3βHSD was not found in scented glands during the breeding season. These novel findings provide the first evidence showing that scented glands of the muskrats are capable of locally synthesizing androgens and androgens acting via an endocrine, autocrine or paracrine manner may play an important role in scented gland function during the breeding season.

  6. Average glandular dose in routine mammography screening using a Sectra Microdose Mammography unit

    International Nuclear Information System (INIS)

    The Sectra MicroDose Mammography system is based on direct photon counting (with a solid-state detector), and a substantially lower dose to the breast than when using conventional system can be expected. In this work absorbed dose measurements have been performed for the first unit used in routine mammography screening (at the Hospitals of Helsingborg (Sweden)). Two European protocols on dosimetry in mammography have been followed. Measurement of half value layer (HVL) cannot be performed as prescribed, but this study has demonstrated than non-invasive measurements of HVL can be performed accurately with a sensitive and well collimated solid-state detector with simultaneous correction for the energy dependence. The average glandular dose for a 50 mm standard breast with 50% glandularity, simulated by 45 mm polymethylmethacrylate, was found to be 0.21 and 0.28 mGy in March and December 2004, respectively. These values are much lower than for any other mammography system on the market today. It has to be stressed that the measurement were made using the current clinical settings and that no systematic optimisation of the relationship between absorbed dose and diagnostic image quality has been performed within the present study. In order to further increase the accuracy of absorbed dose measurements for this unit, the existing dose protocols should be revised to account also for the tungsten/aluminium anode/filter combination, the multi-slit pre-collimator device and the occurrence of a dose profile in the scanning direction. (authors)

  7. A mammographic phantom to measure mean glandular dose by thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    We have designed a phantom to evaluate mean glandular dose (MGD) as part of the regulatory dosimetry control for mammographic equipment. The phantom is constituted by TLD-100 thermoluminescent dosemeters (TLDs) inserted within semicircular plates of acrylic. Different groups of TLDs are used to determine entrance surface air kerma and half-value layer (HVL). Calibration of both tasks has been performed using a Senographe 2000D system and an ionization chamber. The phantom has been tested in five clinical systems. The HVL and MGD obtained by this method agree, on average, within 3%, with those from standard procedures based on the use of ionization chambers. The phantom MGD measurements have a combined uncertainty better than 10% (k = 1). - Highlights: • We have designed a phantom to evaluate mean glandular dose (MGD). • We used TLD-100 dosemeters inserted within semicircular plates of acrylic. • The system has been tested in five clinical systems. • MGD obtained by this method agrees within 3% with ionization chambers. • MGD measurements have a combined uncertainty better than 10% (k = 1)

  8. Measuring Irish capital

    OpenAIRE

    Keeney, Mary J.

    2007-01-01

    Irish National Income and Expenditure Accounts do not contain information on capital stocks or capital services estimation. Estimates of the national capital stock and the depreciation of its fixed assets are basic macroeconomic aggregates and are integral components for many modelling exercises. This paper will present a detailed asset-level analysis of the stocks and depreciation of Irish fixed assets and the capital formation flows used to derive them. It will apply an improved perpetual i...

  9. Welfare Enhancing Capital Imports

    OpenAIRE

    Masao Oda; Koji Shimomura; Ryuhei Wakasugi

    2007-01-01

    This paper provides a model to consider the conditions under which an acceptance of foreign capital is welfare enhancing in a multi-commodity multi-factor framework. Contrary to the pessimistic conventional wisdom of capital imports and welfare, we provide a justification for the acceptance of foreign capital and the diversification of industrial structure in developing countries. A sufficient condition for the acceptance of foreign capital to be welfare enhancing is that all domestic factors...

  10. Institutions, Capital, and Growth

    OpenAIRE

    2010-01-01

    The international development community has encouraged investment in physical and human capital as a precursor to economic progress. Recent evidence shows, however, that increases in capital do not always lead to increases in output. We develop a growth model where the allocation and productivity of capital depends on a country's institutions. We find that increases in physical and human capital lead to output growth only in countries with good institutions. In countries with bad institutions...

  11. Acceptance of the EU regulations on mean doses of glandular on women's during mammographic examination in the Czech Republic

    International Nuclear Information System (INIS)

    Diagnostic reference levels (further DRU) are on indications for medical irradiation regulation. DRU = 3 mGy per pictures and standard breast thickness 45 mm was used for cc projection during mammographic examination in the Czech Republic. However the examinations in EU country indicated that the mean glandular dose for standard breast thickness 45 mm was reduced to a Dg =2 mGy per picture. At the same time there was a change of standard breast thickness from 45 mm to 53 mm, new standard for glandular dose was set up to Dg = 2.5 mGy. The aim is to estimate, whether glandular dose measured during examinations in cz fulfil recommended levels for particular PMMA equivalent thickness as stated above. (authors)

  12. Assessment of glandular dose and image quality in mammography using computerised radiography employing a polymethylmetacrilate breast simulator

    International Nuclear Information System (INIS)

    In Brazil there are around 600 mammography equipment with CR system. Taking into account the quality of image is essential to evaluate the mean glandular dose so you can optimize the radiation protection of patients evaluated with this type of system. Therefore, this study aimed to determine the mean glandular dose and quality of image for the CR system of laboratory of radioprotection applied to mammography of the Centre of Development of Nuclear Technology (CDTN). For this, we evaluated the linearity of the detector’s response, contrast to noise ratio and signal to noise ratio, which, according to European protocol, showed results within acceptable limits. Next, evaluated the quality of image with the CDMAM Phantom and mean glandular dose to the detector Fluke Biomedical TNT 12000WD, where they presented, respectively, within the results expected by the manufacturer and the limits of acceptable and desirable by the European protocol. then, the CR system of CDTN is optimized.

  13. CONTROLS ON CAPITAL MOVEMENTS

    Directory of Open Access Journals (Sweden)

    Petris Sorina

    2012-12-01

    Full Text Available Until recently, capital mobility was encouraged across national borders, because it was considered that such capital can seek the highest rate of return. However, recent global financial developments have shown that, due to contagion, the mobility of capital flows can cause severe financial imbalances. In the context of globalization, liberalization or maintaining controls on capital flows is a current topic, more debated by economists. This topic is very important, due to the impact of liberalization decision or maintaining controls on capital flows has on the overall macroeconomic framework. The paper analyzes the relationship between capital flows’ control and the income per capita, the degree of central bank independence, democracy country, the foreign exchange regime. Also, it analyzes the effectiveness in time of capital controls, taking account of financial system development and potential risks of instability. Over time, it was observed that a period in which they have imposed restrictions on capital movements was followed by a removal of such restrictions, and vice versa. Cyclic change of capital movements regime corresponds to the cyclic evolution of the global economy. Full capital account liberalization led to the emergence of currency and financial crises, so that the idea of maintaining controls on capital is not rejected by economists. After a full liberalization of capital flows, there is a change in the mentality of an increasing number of economists, who support the maintenance of controls, in a gradual liberalization.

  14. Four Books on Capitalism

    OpenAIRE

    Streeck, W.

    2009-01-01

    Christoph Deutschmann Kapitalistische Dynamik: Eine gesellschaftstheoretische Perspektive. Wiesbaden, VS Verlag, 2008 Geoffrey Ingham Capitalism. Oxford, Polity, 2008 John McMurtry The Cancer Stage of Capitalism. London, Pluto, 1999 Frederic L. Pryor The Future of U.S. Capitalism. New York, Cambridge University Press, 2002

  15. Estimation of average glandular dose depending on the thickness of the breast; Estimativa da dose glandular media em funcao da espessura da mama

    Energy Technology Data Exchange (ETDEWEB)

    Real, Jessica V.; Luz, Renata M. da, E-mail: jessica.real@pucrs.br, E-mail: renata.luz@pucrs.br [Hospital Sao Lucas (HSL/PUCRS), Porto Alegre, RS (Brazil); Fröhlich, Bruna D.; Pertile, Alessandra S.; Silva, Ana Maria Marques da, E-mail: bruna.frohlich@acad.pucrs.br, E-mail: lessandra.pertile@acad.pucrs.br, E-mail: ana.marques@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil)

    2014-07-01

    Breast cancer is the most common type of cancer in women worldwide. Mammography is, to date, the most efficient method for detecting an abnormality in the patient's breast. It is a technique of imaging diagnostic that requires special care because radiographs without adequate quality may lead to a false diagnosis and lead to the need for a repeat examination, increasing the dose of radiation in the patient. This study aimed to evaluate the average glandular dose (AGD), depending on the breast thickness in patients undergoing routine tests, with a digital computer radiography processing system. Analyzed 30 exhibitions in patients aged (65 ± 12) years, in the right and left caudal skull projections, for breasts with thicknesses between 45 mm and 50 mm. The calculated value of the AGD for this track thickness was (1.600 ± 0.009) mGy. The performance of mammography quality control tests was satisfactory and the AGD values obtained for the chosen thickness range is acceptable, since the threshold achievable is 1.6 mGy and the acceptable is 2 mGy. In Brazil, it is only required the input dose calculation in skin for 45 mm breasts. However, the calculation of AGD is required for different thicknesses of the breast, to identify the best mammographic pattern aiming at better image quality at the lowest dose provided the patient.

  16. TU-F-18C-05: Evaluation of a Method to Calculate Patient-Oriented MGD Coefficients Using Estimates of Glandular Tissue Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Porras-Chaverri, M [University of Wisconsin-Madison, Madison, WI (United States); University of Costa Rica, San Jose (Costa Rica); Galavis, P [NYU Langone Medical Center, New York, NY (United States); Bakic, P [University of Pennsylvania, Philadelphia, PA (United States); Vetter, J [University of Wisconsin-Madison, Madison, WI (United States)

    2014-06-15

    Purpose: Evaluate mammographic mean glandular dose (MGD) coefficients for particular known tissue distributions using a novel formalism that incorporates the effect of the heterogeneous glandular tissue distribution, by comparing them with MGD coefficients derived from the corresponding anthropomorphic computer breast phantom. Methods: MGD coefficients were obtained using MCNP5 simulations with the currently used homogeneous assumption and the heterogeneously-layered breast (HLB) geometry and compared against those from the computer phantom (ground truth). The tissue distribution for the HLB geometry was estimated using glandularity map image pairs corrected for the presence of non-glandular fibrous tissue. Heterogeneity of tissue distribution was quantified using the glandular tissue distribution index, Idist. The phantom had 5 cm compressed breast thickness (MLO and CC views) and 29% whole breast glandular percentage. Results: Differences as high as 116% were found between the MGD coefficients with the homogeneous breast core assumption and those from the corresponding ground truth. Higher differences were found for cases with more heterogeneous distribution of glandular tissue. The Idist for all cases was in the [−0.8{sup −}+0.3] range. The use of the methods presented in this work results in better agreement with ground truth with an improvement as high as 105 pp. The decrease in difference across all phantom cases was in the [9{sup −}105] pp range, dependent on the distribution of glandular tissue and was larger for the cases with the highest Idist values. Conclusion: Our results suggest that the use of corrected glandularity image pairs, as well as the HLB geometry, improves the estimates of MGD conversion coefficients by accounting for the distribution of glandular tissue within the breast. The accuracy of this approach with respect to ground truth is highly dependent on the particular glandular tissue distribution studied. Predrag Bakic discloses

  17. TU-F-18C-05: Evaluation of a Method to Calculate Patient-Oriented MGD Coefficients Using Estimates of Glandular Tissue Distribution

    International Nuclear Information System (INIS)

    Purpose: Evaluate mammographic mean glandular dose (MGD) coefficients for particular known tissue distributions using a novel formalism that incorporates the effect of the heterogeneous glandular tissue distribution, by comparing them with MGD coefficients derived from the corresponding anthropomorphic computer breast phantom. Methods: MGD coefficients were obtained using MCNP5 simulations with the currently used homogeneous assumption and the heterogeneously-layered breast (HLB) geometry and compared against those from the computer phantom (ground truth). The tissue distribution for the HLB geometry was estimated using glandularity map image pairs corrected for the presence of non-glandular fibrous tissue. Heterogeneity of tissue distribution was quantified using the glandular tissue distribution index, Idist. The phantom had 5 cm compressed breast thickness (MLO and CC views) and 29% whole breast glandular percentage. Results: Differences as high as 116% were found between the MGD coefficients with the homogeneous breast core assumption and those from the corresponding ground truth. Higher differences were found for cases with more heterogeneous distribution of glandular tissue. The Idist for all cases was in the [−0.8−+0.3] range. The use of the methods presented in this work results in better agreement with ground truth with an improvement as high as 105 pp. The decrease in difference across all phantom cases was in the [9−105] pp range, dependent on the distribution of glandular tissue and was larger for the cases with the highest Idist values. Conclusion: Our results suggest that the use of corrected glandularity image pairs, as well as the HLB geometry, improves the estimates of MGD conversion coefficients by accounting for the distribution of glandular tissue within the breast. The accuracy of this approach with respect to ground truth is highly dependent on the particular glandular tissue distribution studied. Predrag Bakic discloses current funding

  18. Is Capitalism Ethical?

    Directory of Open Access Journals (Sweden)

    Suciu T.

    2009-12-01

    Full Text Available The author of this paper have set off from the question: is the present capitalism ethical? We started with the delimitation and correlation of the concepts of ethics, morals, morality. Further on, we analysed the evolution of capitalism in connection with morals. Based on this research, we came to the conclusion that the capitalist system has undergone through three stages: moral capitalism, amoral capitalism, and immoral capitalism. We concluded by implying that the corporate capitalist society is immoral, that it cannot regulate itself and that the government’s assistance is needed to inoculate the ethics.

  19. Penetration of UV-A, UV-B and blue light through the leaf trichome layers of two xeromorphic plants, olive and oak, measured by optical fibre microprobes

    International Nuclear Information System (INIS)

    Quartz fibre-optic microprobes were used to monitor the light microenvironment beneath trichome layers of the xeromorphic leaves of two Mediterranean evergreen sclerophylls, Olea europaea and Quercus ilex. Young developing leaves of both plants were densely pubescent on both surfaces of the lamina, whereas the mature leaves were pubescent only on the abaxial side. Trichome layers of young as well as of mature leaves of both plants attenuated almost all incident ultraviolet (UV)-B (310 nm) and UV-A (360 nm) radiation and a considerable portion of blue light (430 nm). Abaxial trichome layers of young leaves were more effective in screening out the incident radiation compared to the adaxial ones of the same leaves and also compared to the abaxial layer of the mature leaves. The abaxial epidermis of dehaired mature leaves of O. europaea was ineffective in absorbing most of the incident UV-B and UV-A radiation. UV and visible spectra beneath trichome layers of O. europaea in mature leaves confirmed that the light microenvironment on the epidermis was deprived in the UV-B, UV-A and partly in the blue spectral regions. It is proposed that the occurrence of a dense trichome layer, especially in young leaves, may play a protective role against not only UV-B radiation damage, but also against high visible irradiance. This function is performed irrespective of the differing anatomy of individual hairs of both plants. The protection provided by the trichomes could afford advantages under stress conditions, especially during leaf development. (author)

  20. Viability of dried vegetative trichomes, formation of akinetes and heterocysts and akinete germination in some blue-green algae under water stress.

    Science.gov (United States)

    Agrawal, S C; Singh, V

    1999-01-01

    Almost all dried vegetative trichomes ofAnabaena iyengarii, Westiellopsis prolifica andNostochopsis lobatus died within 1 h, while those ofOscillatoria acuminata retained viability to some extent for 1 d under similar storage conditions. The viability of dried vegetative trichomes ofO. acuminata decreased about equally on storage at 20 degrees C in the light or in the dark, but dropped rapidly at 12 and 0 degrees C in the dark. Vegetative trichomes ofA. iyengarii, N. lobatus andW. prolifica were more sensitive to frost than those ofO. acuminata, and this correlated with their low resistance to desiccation because both types of exposure involved osmotic stress. Both dried and wet akinetes ofA. iyengarii, W. prolifica andN. lobatus were about equally viable when stored at 20 degrees C in the light or the dark or at 12 and 0 degrees C in the dark, but their germination ability decreased on storage at 0 degrees C. The water stress imposed on growing vegetative trichomes either in high-agar media or in NaCl-supplemented liquid media reduced the survival ofO. acuminata trichomes, decreased or totally suppressed akinete and heterocyst formation and akinete germination inA. iyengarii, W. prolifica andN. lobatus. The sensitivity decreased in the sequenceA. iyengarii green algae was more sensitive to physiological water stress than their formation. In all of them, akinetes formed under water stress were equally viable as those formed under normal conditions. Trichomes ofO. acuminata became broader when grown in 0.5-0.8 mol/L NaCl-supplemented media, probably due to polyol accumulation, and they also developed a thin sheath-like structure. PMID:18461490

  1. INTERPRETING OVERALL INEQUALITY IN CHINA: THE ROLES OF PHYSICAL CAPITAL, HUMAN CAPITAL AND SOCIAL CAPITAL

    OpenAIRE

    Yuheng LI; Westlund, Hans

    2013-01-01

    This paper investigates the relationship between overall inequality in China and the contributions of physical capital, human capital and social capital. The investment in physical capital tends to enlarge overall inequality while human capital helps to reduce the inequality. Human capital appears to be more influential than physical capital in overall inequality reduction in the research period. Social capital (people's social networks) however, does not seem to exert any impact on overall i...

  2. UV‐B is Required for Normal Development of Oil Glands in Ocimum basilicum L. (Sweet Basil)

    OpenAIRE

    IOANNIDIS, DAPHNE; Bonner, Lynda; Johnson, Christopher B.

    2002-01-01

    Plants of Ocimum basilicum L. grown under glass were exposed to short treatments with supplementary UV‐B. The effect of UV‐B on volatile essential oil content was analysed and compared with morphological effects on the peltate and capitate glandular trichomes. In the absence of UV‐B, both peltate and capitate glands were incompletely developed in both mature and developing leaves, the oil sacs being wrinkled and only partially filled. UV‐B was found to have two main effects on the glandular t...

  3. Functional characterization of TRICHOMELESS2, a new single-repeat R3 MYB transcription factor in the regulation of trichome patterning in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Gan Lijun

    2011-12-01

    Full Text Available Abstract Background Single-repeat R3 MYB transcription factors (single-repeat MYBs play important roles in controlling trichome patterning in Arabidopsis. It was proposed that single-repeat MYBs negatively regulate trichome formation by competing with GLABRA1 (GL1 for binding GLABRA3/ENHANCER OF GLABRA3 (GL3/EGL3, thus inhibiting the formation of activator complex TTG1(TRANSPARENT TESTA GLABRA1-GL3/EGL3-GL1 that is required for the activation of GLABRA2 (GL2, whose product is a positive regulator of trichome formation. Previously we identified a novel single-repeat MYB transcription factor, TRICHOMELESS1 (TCL1, which negatively regulates trichome formation on the inflorescence stems and pedicels by directly suppressing the expression of GL1. Results We analyzed here the role of TRICHOMELESS2 (TCL2, a previously-uncharacterized single-repeat MYB transcription factor in trichome patterning in Arabidopsis. We showed that TCL2 is closely related to TCL1, and like TCL1 and other single-repeat MYBs, TCL2 interacts with GL3. Overexpression of TCL2 conferred glabrous phenotype while knockdown of TCL2 via RNAi induced ectopic trichome formation on the inflorescence stems and pedicels, a phenotype that was previously observed in tcl1 mutants. These results suggested that TCL2 may have overlapping function with TCL1 in controlling trichome formation on inflorescences. On the other hand, although the transcription of TCL2, like TCL1, is not controlled by the activator complex formed by GL1 and GL3, and TCL2 and TCL1 proteins are more than 80% identical at the amino acid level, the expression of TCL2 under the control of TCL1 promoter only partially recovered the mutant phenotype of tcl1, implying that TCL2 and TCL1 are not fully functional equivalent. Conclusions TCL2 function redundantly with TCL1 in controlling trichome formation on inflorescences, but they are not fully functional equivalent. Transcription of TCL2 is not controlled by activator complex

  4. Human Capital, Bankruptcy and Capital Structure

    OpenAIRE

    Jonathan B. Berk; Richard Stanton; Josef Zechner

    2007-01-01

    We derive a firm's optimal capital structure and managerial compensation contract when employees are averse to bearing their own human capital risk, while equity holders can diversify this risk away. In the presence of corporate taxes, our model delivers optimal debt levels consistent with those observed in practice. It also makes a number of predictions for the cross-sectional distribution of firm leverage. Consistent with existing empirical evidence, it implies persistent idiosyncratic diff...

  5. Capital Utilization and Capital Accumulation: Theory and Evidence

    OpenAIRE

    Shapiro, Matthew D.

    1986-01-01

    A firm may acquire additional capital input by purchasing new capital or by increasing the utilization of its current capital. The margin between capita accumulation and capital utilization is studied in a model of dynamic factor demand where the firm chooses capital, labor, and their rates of utilization. A direct measure of capital utilization -- the work week of capital -- is incorporated into the theory and estimates. The methodology advocated by Hansen and Singleton (1982) is used to obt...

  6. THE EFFECT OF HUMAN CAPITAL ON SOCIAL CAPITAL AMONG ENTREPRENEURS

    OpenAIRE

    HANNES OTTÓSSON; KIM KLYVER

    2010-01-01

    Using data collected from 714 entrepreneurs in a random sample of 10,000 Danes, this study provides an investigation of the effect of human capital on social capital among entrepreneurs. Previous entrepreneurship research has extensively investigated the separated effect of human capital and social capital on different entrepreneurial outputs. The study takes a step back and investigates how these two capital concepts are related — specifically how human capital influences social capital. In ...

  7. Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias

    DEFF Research Database (Denmark)

    Holl, Katsiaryna; Nowakowski, Andrzej M; Powell, Ned;

    2015-01-01

    Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providing......: 0%). The most common HPV types were restricted to HPV16/18/45, accounting for 98.3% of all HPV-positive ADC. There were variations in HPV prevalence and ADC type-distribution by country. Age at diagnosis differed by ADC subtype, with usual-type diagnosed in younger women (median: 43 years) compared...... uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type-distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461...

  8. A Quality Assurance programme in mammography and an evaluation of the mean glandular dose

    International Nuclear Information System (INIS)

    The use of X-ray in medicine for diagnosis represents the largest man-made sources of public exposure to ionizing radiation. Therefore a reduction of medical exposure is desired without reduction of the diagnostic capability. Dose and image quality are essential component of a Quality Assurance (QA) programme in mammography where the characteristic of diagnostic signs, represented by microcalcifications and low contrast structures, and the radiosensitivity of the glandular tissue of the breast stress the need of QA programme. The paper describes QA procedures in mammography and reports the results obtained in more than 120 periodic tests, performed on 63 mammographic units of 41 centers. Moreover individual evaluation of entrance exposure are presented for 340 patients. The experimental data permits to evaluate the mean grandular absorbed dose in the single exams using different procedures based on Monte Carlo simulations. (author)

  9. Evaluation of mean glandular dose in a full-field digital mammography unit in Tabriz (IR)

    International Nuclear Information System (INIS)

    This study was aimed at evaluating the mean glandular dose (MGD) and affecting factors during mammography examinations by a full-field digital mammography unit. An extensive quality control program was performed to assure that the unit is properly working. Required information including compressed breast thickness (CBT), breast parenchymal pattern and technical factors used for imaging were recorded. An entrance skin exposure measurement was also performed using slabs of polymethylmethacrylate with 2-8 cm thickness. On the basis of recorded information and measured data, the MGD was estimated for 1145 mammography examinations obtained from 298 patients. Mean CBTs of 4.9 and 5.8 cm and MGDs of 2 and 2.4 mGy were observed for cranio-caudal and medio-lateral oblique views, respectively. Significant correlation was seen between MGD and CBT, breast parenchymal pattern and applied kVp and mAs. (authors)

  10. Effect of filter on average glandular dose and image quality in digital mammography

    Science.gov (United States)

    Songsaeng, C.; Krisanachinda, A.; Theerakul, K.

    2016-03-01

    To determine the average glandular dose and entrance surface air kerma in both phantoms and patients to assess image quality for different target-filters (W/Rh and W/Ag) in digital mammography system. The compressed breast thickness, compression force, average glandular dose, entrance surface air kerma, peak kilovoltage and tube current time were recorded and compared between W/Rh and W/Ag target filter. The CNR and the figure of merit were used to determine the effect of target filter on image quality. The mean AGD of the W/Rh target filter was 1.75 mGy, the mean ESAK was 6.67 mGy, the mean CBT was 54.1 mm, the mean CF was 14 1bs. The mean AGD of W/Ag target filter was 2.7 mGy, the mean ESAK was 12.6 mGy, the mean CBT was 75.5 mm, the mean CF was 15 1bs. In phantom study, the AGD was 1.2 mGy at 4 cm, 3.3 mGy at 6 cm and 3.83 mGy at 7 cm thickness. The FOM was 24.6, CNR was 9.02 at thickness 6 cm. The FOM was 18.4, CNR was 8.6 at thickness 7 cm. The AGD from Digital Mammogram system with W/Rh of thinner CBT was lower than the AGD from W/Ag target filter.

  11. Glandular Proteome Identifies Antiprotease Cystatin C as a Critical Modulator of Airway Hydration and Clearance.

    Science.gov (United States)

    Evans, T Idil Apak; Joo, Nam Soo; Keiser, Nicholas W; Yan, Ziying; Tyler, Scott R; Xie, Weiliang; Zhang, Yulong; Hsiao, Jordy J; Cho, Hyung-Ju; Wright, Michael E; Wine, Jeffrey J; Engelhardt, John F

    2016-04-01

    Defects in the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel lead to viscous secretions from submucosal glands that cannot be properly hydrated and cleared by beating cilia in cystic fibrosis (CF) airways. The mechanisms by which CFTR, and the predominant epithelial sodium channel (ENaC), control the hydration and clearance of glandular secretions remain unclear. We used a proteomics approach to characterize the proteins contained in CF and non-CF submucosal gland fluid droplets and found that differentially regulated proteases (cathepsin S and H) and their antiprotease (cystatin C) influenced the equilibration of fluid on the airway surface and tracheal mucociliary clearance (MCC). Contrary to prevailing models of airway hydration and clearance, cystatin C, or raising the airway surface liquid (ASL) pH, inhibited cathepsin-dependent ENaC-mediated fluid absorption and raised the height of ASL, and yet decreased MCC velocity. Importantly, coupling of both CFTR and ENaC activities were required for effective MCC and for effective ASL height equilibration after volume challenge. Cystatin C-inhibitable cathepsins controlled initial phases of ENaC-mediated fluid absorption, whereas CFTR activity was required to prevent ASL dehydration. Interestingly, CF airway epithelia absorbed fluid more slowly owing to reduced cysteine protease activity in the ASL but became abnormally dehydrated with time. Our findings demonstrate that, after volume challenge, pH-dependent protease-mediated coupling of CFTR and ENaC activities are required for rapid fluid equilibration at the airway surface and for effective MCC. These findings provide new insights into how glandular fluid secretions may be equilibrated at the airway surface and how this process may be impaired in CF. PMID:26334941

  12. PTEN Phosphatase-Independent Maintenance of Glandular Morphology in a Predictive Colorectal Cancer Model System

    Directory of Open Access Journals (Sweden)

    Ishaan C. Jagan

    2013-11-01

    Full Text Available Organotypic models may provide mechanistic insight into colorectal cancer (CRC morphology. Three-dimensional (3D colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN coupling of cell division cycle 42 (cdc42 to atypical protein kinase C (aPKC. This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3 were ineffective. The isolated PTEN C2 domain (C2 accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na+/H+ exchanger regulatory factor-1 (NHERF-1 in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.

  13. Atypical glandular cells in conventional cervical smears: Incidence and follow-up

    Directory of Open Access Journals (Sweden)

    Knolle Ulrich

    2004-07-01

    Full Text Available Abstract Background Atypical glandular cells on cervical smears are often associated with clinically significant uterine lesions. The frequency and accuracy of AGC-NOS (i.e. atypical glandular cells, not otherwise specified diagnoses, regardless of the gland cell type or the degree of suspicion, and their outcome were investigated. Methods From January 1, 1990 to December 31, 1999 a total of 261 patients had an AGC-NOS diagnosis made by conventional cervical Papanicolaou smear interpretation representing 0.05% of all Pap-smears analyzed at the national level. 191 (73.2% patients had a subsequent histological examination, 8 samples were not representative by origin and were excluded. Results Out of 183 AGC-NOS diagnosed, 56.3% (103/183 were associated with tissue-proven precancerous and/or cancerous lesions, 44% being of endocervical and 56% of endometrial origin. 75% of all AGC-patients were asymptomatic. 66.7% (6/9 of the patients with subsequent invasive endocervical adenocarcinoma (AC and 56% (28/50 of those patients with invasive endometrial AC were without clinical symptoms. 3 patients out of 9 with an invasive endocervical AC were 35 years of age or less. 10.1% and 12.3% of all 'new' tissue-proven invasive endocervical or endometrial AC respectively recorded by the national Morphologic Tumour Registry (MTR were first identified by a cytological AGC-NOS diagnosis. Conclusion Our findings emphasize the importance of the cytological AGC-category even in the absence of a precise origin or cell type specification. 56% of the AGC-diagnoses being associated with significant cancerous or precancerous conditions, a complete and careful evaluation is required.

  14. Clinical implications and histological correlation of atypical glandular cells found in cervicovaginal smears

    Directory of Open Access Journals (Sweden)

    Beliza Loos

    2014-08-01

    Full Text Available Introduction: Atypical glandular cells (AGC are carriers of insufficient nuclear abnormalities for the diagnosis of adenocarcinoma, but exceed the criteria for classification as reactive glandular cells. This is an uncommon diagnosis, which may be associated with neoplastic lesions. Objective: To evaluate the clinical significance of primary cytological diagnosis of AGC through correlation with results of subsequent cyto-histologic examination. Materials and methods: 10 years retrospective study based on cervical cytologic results indicating AGC, classified as "possibly non-neoplastic" or "cannot exclude high-grade intraepithelial lesion". It was performed cyto-histopathological correlation in cases that were submitted to subsequent histopathological examination up to two years after cervical cytology analysis. Results: AGC were reported in 380 (0.06% exams, providing 160 cases with subsequent biopsy. 85 (53.1% of these, presented benign changes and 75 (46.9% neoplastic lesions. From 114 "possibly non-neoplastic" cytological results, 71 (62.3% had benign histological changes, and 43 (37.7% neoplastic lesions, corresponding to a negative predictive value (NPV of 62.3%. In contrast, among the 46 AGC "cannot exclude high-grade intraepithelial lesion" results, 14 (30.4% presented benign changes and 32 (69.6% neoplastic lesions (positive predictive value [PPV] = 69.6%. Discussion: The high rate of cancer associated with the diagnosis of AGC reassures the importance of recognizing these atypical cells in pap smears. The classification of "possibly non-neoplastic" and "cannot exclude high-grade intraepithelial lesion" may suggest the origin of cytological changes. Conclusion: Our results reinforce the importance of adequate follow-up of patients with AGC diagnosis on cervical cytology.

  15. Estimation of glandular content rate and statistical analysis of the influence of age group and compressed breast thickness on the estimated value

    International Nuclear Information System (INIS)

    Because the glandular content rate is an important factor in evaluating breast cancer detection and average glandular dose, it is important in mammography research to estimate and analyze this rate. The purpose of this study was to obtain a formula for statistical estimation of the glandular content rate, to clarify statistically the influence of age group and compressed breast thickness (CBT) on estimating the glandular content rate, and to show statistically the general relation between glandular content rate and the factors of age and CBT. The subjects were 740 Japanese women aged 20-91 years (mean±SD: 48.3±12.8 years) who had undergone mammography. In our study, the glandular content rate was statistically estimated from age group, mAs-value, and CBT when subjects underwent mammography, from a phantom simulation, and from MR images of the breast. In addition, multivariate analysis was carried to examine statistically the influence of age group and CBT on glandular content rate. The mean glandular content rate as estimated by age group was as follows: 35.6% for those in their 20s, 33.4% in the 30s, 27.5% in the 40s, 23.8% in the 50s, and 21.8% in those 60 and over. The rate for the subjects as a whole was 27.1%. This study indicated that overestimation occurred if the estimated value of the glandular content rate was not corrected in the 3D-measurement by MRI. In addition, this study showed that the statistical influence on glandular content rate was significantly larger for CBT than age. (author)

  16. Estimates of Average Glandular Dose with Auto-modes of X-ray Exposures in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Izdihar Kamal

    2015-05-01

    Full Text Available Objectives: The aim of this research was to examine the average glandular dose (AGD of radiation among different breast compositions of glandular and adipose tissue with auto-modes of exposure factor selection in digital breast tomosynthesis. Methods: This experimental study was carried out in the National Cancer Society, Kuala Lumpur, Malaysia, between February 2012 and February 2013 using a tomosynthesis digital mammography X-ray machine. The entrance surface air kerma and the half-value layer were determined using a 100H thermoluminescent dosimeter on 50% glandular and 50% adipose tissue (50/50 and 20% glandular and 80% adipose tissue (20/80 commercially available breast phantoms (Computerized Imaging Reference Systems, Inc., Norfolk, Virginia, USA with auto-time, auto-filter and auto-kilovolt modes. Results: The lowest AGD for the 20/80 phantom with auto-time was 2.28 milliGray (mGy for two dimension (2D and 2.48 mGy for three dimensional (3D images. The lowest AGD for the 50/50 phantom with auto-time was 0.97 mGy for 2D and 1.0 mGy for 3D. Conclusion: The AGD values for both phantoms were lower against a high kilovolt peak and the use of auto-filter mode was more practical for quick acquisition while limiting the probability of operator error.

  17. Optimizing the anode-filter combination in the sense of image quality and average glandular dose in digital mammography

    Science.gov (United States)

    Varjonen, Mari; Strömmer, Pekka

    2008-03-01

    This paper presents the optimized image quality and average glandular dose in digital mammography, and provides recommendations concerning anode-filter combinations in digital mammography, which is based on amorphous selenium (a-Se) detector technology. The full field digital mammography (FFDM) system based on a-Se technology, which is also a platform of tomosynthesis prototype, was used in this study. X-ray tube anode-filter combinations, which we studied, were tungsten (W) - rhodium (Rh) and tungsten (W) - silver (Ag). Anatomically adaptable fully automatic exposure control (AAEC) was used. The average glandular doses (AGD) were calculated using a specific program developed by Planmed, which automates the method described by Dance et al. Image quality was evaluated in two different ways: a subjective image quality evaluation, and contrast and noise analysis. By using W-Rh and W-Ag anode-filter combinations can be achieved a significantly lower average glandular dose compared with molybdenum (Mo) - molybdenum (Mo) or Mo-Rh. The average glandular dose reduction was achieved from 25 % to 60 %. In the future, the evaluation will concentrate to study more filter combinations and the effect of higher kV (>35 kV) values, which seems be useful while optimizing the dose in digital mammography.

  18. Histochemical Investigation and Kinds of Alkaloids in Leaves of Different Developmental Stages in Thymus quinquecostatus

    Directory of Open Access Journals (Sweden)

    Haiting Jing

    2014-01-01

    Full Text Available Thymus quinquecostatus, with more medical value, is a kind of wild plants. In order to exploit and utilize this plant, we studied the species and locations of alkaloids in its leaves. In this paper, histochemical study of leaves at different developing stages was taken to localize the alkaloids. Meanwhile, the kinds and content of alkaloids in leaves were identified using GC-MS technique. It was found that there were two kinds of glandular trichomes, namely, peltate trichomes and capitate trichomes, on the surface of leaves, and their secretory cells could secrete alkaloids. Results showed that trichomes could secrete alkaloids as soon as the first pair of leaves formed, and there were altogether 18 kinds of alkaloids identified by GC-MS. Nearly all of these alkaloids of leaves at different developing stages were distinct from each other, except one, 3-methoxy-a-methyl-benzeneethanamine, persists at different developing stages with high concentration.

  19. Capital mobility. An overview

    OpenAIRE

    Arndt, H. W.

    2000-01-01

    The article analyses the problem of international capital mobility which the Asian crisis has highlighted. It points out that the problem of capital mobility ("hot money" panics) has a long history, but globalization, the opening up of national economies and technological advance have increased the risks. The article discusses four policy debated which are being pursued in the large Asian crisis literature: (i) the pros and cons of capital controls; (ii) the choice of exchange rate regime; (i...

  20. Development and Social Capital

    OpenAIRE

    Fafchamps, Marcel

    2005-01-01

    This paper examines social capital and its relation with economic development. We focus on the role that interpersonal relationships play in social exchange, whether through the market or through the provision of public goods. By facilitating search and trust, social capital can increase the efficiency of social exchange where formal institutions are weak. But the benefits from social capital are likely to be unequally distributed. Given these features, documenting empirically the benefits of...

  1. Determinants of Soil Capital

    OpenAIRE

    Ekbom, Anders

    2008-01-01

    This paper combines knowledge from soil science and economics to estimate economic determinants of soil capital. Explaining soil capital facilitates a better understanding of constraints and opportunities for increased agricultural production and reduced land degradation. This study builds on an unusually rich data set that combines data on soil capital (represented by chemical and physical properties) and economic data on household characteristics, labor supply, crop allocation, and conserva...

  2. ACCOUNT INSTRUMENT CAPITAL BORROWED

    Directory of Open Access Journals (Sweden)

    Holt Gheorghe

    2012-03-01

    Full Text Available Setting up business capital is made from different sources and their use coordinates its policy aims, issues that affect the overall efficiency and thus differentiate companies with the same profile of activity and a similar level of capital advanced in the economic cycle. Thus financial structure, the average cost of capital used in the mechanism how the financial management of the company, of particular importance for this.

  3. Human capital and productivity

    OpenAIRE

    Fuente, Ángel de la

    2011-01-01

    This paper surveys the empirical literature on human capital and productivity and summarizes the results of my own work on the subject. On balance, the available evidence suggests that investment in education has a positive, significant and sizable effect on productivity growth. According to my estimates, moreover, the social returns to investment in human capital are higher than those on physical capital in most EU countries and in many regions of Spain.

  4. KVA: Capital Valuation Adjustment

    OpenAIRE

    Andrew Green; Chris Kenyon

    2014-01-01

    Credit (CVA), Debit (DVA) and Funding Valuation Adjustments (FVA) are now familiar valuation adjustments made to the value of a portfolio of derivatives to account for credit risks and funding costs. However, recent changes in the regulatory regime and the increases in regulatory capital requirements has led many banks to include the cost of capital in derivative pricing. This paper formalises the addition of cost of capital by extending the Burgard-Kjaer (2013) semi-replication approach to C...

  5. Intangible Capital Accounting

    OpenAIRE

    Mihalache Arsenie-Samoil

    2010-01-01

    The new economy based on globalization is increasingly important, which shows the decisive role played by intangible capital in achieving the competitive advantage of companies. However, this intangible capital is the hidden side of a company's value, as it represents the company's intangible resources, which cannot be measured by the financial metrics used to measure tangible resources. Given the functional importance of intangible capital, several models several models were proposed by the ...

  6. Human Capital and Retirement

    OpenAIRE

    Alders, P.

    1999-01-01

    textabstractThis paper investigates the relation between human capital and retirement when the age of retirement is endogenous. This relation is examined in a life-cycle earnings model. An employee works full time until retirement. The worker accumulates human capital by training- on-the-job and by learning-by-doing. The human capital of an employee is subject to depreciation when knowledge of technologies becomes obsolete. After a shock in technology, the worker depreciates on his human capi...

  7. Institutions and Venture Capital

    OpenAIRE

    Lerner, Josh; Tåg, Joacim

    2012-01-01

    We survey the literature on venture capital and institutions and present a case study comparing the development of the venture capital market in the US to Sweden. Our literature survey underscores that the legal environment, financial market development, the tax system, labor market regulations, and public spending on research and development correlates with venture capital activities across countries. Our case study suggests these institutional differences led to the later development of an ...

  8. Social Capital Database

    DEFF Research Database (Denmark)

    Paldam, Martin; Svendsen, Gert Tinggaard

    2005-01-01

      This report has two purposes: The first purpose is to present our 4-page question­naire, which measures social capital. It is close to the main definitions of social capital and contains the most successful measures from the literature. Also it is easy to apply as discussed. The second purpose ...... to present the social capital database we have collected for 21 countries using the question­naire. We do this by comparing the level of social capital in the countries covered. That is, the report compares the marginals from the 21 surveys....

  9. Ectopic expression of R3 MYB transcription factor gene OsTCL1 in Arabidopsis, but not rice, affects trichome and root hair formation

    Science.gov (United States)

    Zheng, Kaijie; Tian, Hainan; Hu, Qingnan; Guo, Hongyan; Yang, Li; Cai, Ling; Wang, Xutong; Liu, Bao; Wang, Shucai

    2016-01-01

    In Arabidopsis, a MYB-bHLH-WD40 (MBW) transcriptional activator complex activates the homeodomain protein gene GLABRA2 (GL2), leading to the promotion of trichome formation and inhibition of root hair formation. The same MBW complex also activates single-repeat R3 MYB genes. R3 MYBs in turn, play a negative feedback role by competing with R2R3 MYB proteins for binding bHLH proteins, thus blocking the formation of the MBW complex. By BLASTing the rice (Oryza sativa) protein database using the entire amino acid sequence of Arabidopsis R3 MYB transcription factor TRICHOMELESS1 (TCL1), we found that there are two genes in rice genome encoding R3 MYB transcription factors, namely Oryza sativa TRICHOMELESS1 (OsTCL1) and OsTCL2. Expressing OsTCL1 in Arabidopsis inhibited trichome formation and promoted root hair formation, and OsTCL1 interacted with GL3 when tested in Arabidopsis protoplasts. Consistent with these observations, expression levels of GL2, R2R3 MYB transcription factor gene GLABRA1 (GL1) and several R3 MYB genes were greatly reduced, indicating that OsTCL1 is functional R3 MYB. However, trichome and root hair formation in transgenic rice plants overexpressing OsTCL1 remained largely unchanged, and elevated expression of OsGL2 was observed in the transgenic rice plants, indicating that rice may use different mechanisms to regulate trichome formation. PMID:26758286

  10. Cervical squamous and glandular intraepithelial neoplasia: identification and current management approaches Neoplasia intraepitelial cervical escamosa y glandular: identificación y estrategias de manejo

    Directory of Open Access Journals (Sweden)

    V Cecil Wright

    2003-01-01

    realiza mediante la biopsia de cono, y el espécimen debe tener márgenes negativos para enfermedad. La histerectomía es un tratamiento probable, a menos que la fertilidad esté siendo buscada. La escisión, particularmente por electrocirugía (loop, puede interferir con la interpretación histológica en algunos casos o de ambos, particularmente en enfermedades escamosas y adenocarcinoma in situ. En este artículo se describe ampliamente el manejo de la neoplasia intraepitelial escamosa y glandular.

  11. Capital-Skill Complementarity: Does capital disaggregation matter?

    OpenAIRE

    Correa, Juan; Lorca, Miguel; Parro, Francisco

    2014-01-01

    Using Chilean manufacturing plants data, we�find: (1) the elasticity of substitution between capital and skilled labor is lower than the elasticity of substitution between capital and unskilled labor, and (2) the higher the technological component of the capital stock the larger the size of complementarity between capital and skilled labor. Our�findings show that capital, as an aggregate input, may under(over) state the complementarity between labor and the type of capital these workers actua...

  12. Capital Flows to Brazil: The Endogeneity of Capital Controls

    OpenAIRE

    Eliane A. Cardoso; Ilan Goldfajn

    1998-01-01

    This paper creates an index of capital controls to analyze the determinants of capital flows to Brazil, accounting for the endogeneity of capital controls by considering a government that sets controls in response to capital flows. It finds that the government reacts strongly to capital flows by increasing controls on inflows during booms and relaxing them in moments of distress. The paper estimates a vector autoregression with capital flows, controls, and interest differentials. It shows tha...

  13. Linguistic Capital Pays Dividends

    Science.gov (United States)

    Linse, Caroline

    2013-01-01

    Some 37 million U.S. residents speak Spanish at home and more than 55% of them say they also speak English. That creates what is called linguistic capital. Although linguistic capital is difficult to quantify, it is enormously valuable and is determined by an individual's language competency, and is too frequently wasted instead of being…

  14. Human Capital and Retirement

    NARCIS (Netherlands)

    P. Alders

    1999-01-01

    textabstractThis paper investigates the relation between human capital and retirement when the age of retirement is endogenous. This relation is examined in a life-cycle earnings model. An employee works full time until retirement. The worker accumulates human capital by training- on-the-job and by

  15. Social Capital in Asia

    DEFF Research Database (Denmark)

    Li, Peter Ping; Redding, Gordon

    2014-01-01

    usually larger, transactions backed by law. For economic development, the systemic form becomes crucial but needs to be compatible with relational norms. The dimensions of social capital are often dual in nature. This article employs a theory that accepts this and analyses the phenomena as yin......This article provides an overview of social capital in Asia. Social capital is trust and appears in two main forms: relational, based on societal norms, and systemic, based on societal institutions. The relational encourages personalistic transactions; and systemic trust, supports more formal, and......–yang balancing, seeing trust as a culturally determined enabler of social cooperation. The evolutions of trustworthiness in Japan, China, and the Philippines are analysed. This article contributes to the literature on varieties of capitalism and business systems as well as that on social capital. It raises the...

  16. Handbook of Social Capital

    DEFF Research Database (Denmark)

    The Handbook of Social Capital balances the ‘troika' of sociology, political science and economics by offering important contributions to the study of bonding and bridging social capital networks. This inter-disciplinary Handbook intends to serve as a bridge for students and scholars within all t...... social sciences. The contributors explore the different scientific approaches that are all needed if international research is to embrace both the bright and the more shadowy aspects of social capital.......The Handbook of Social Capital balances the ‘troika' of sociology, political science and economics by offering important contributions to the study of bonding and bridging social capital networks. This inter-disciplinary Handbook intends to serve as a bridge for students and scholars within all the...

  17. Glandular dose and image quality control in mammography facilities with computerized radiography systems

    International Nuclear Information System (INIS)

    Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

  18. Real-time estimation system for mean glandular dose in mammography

    International Nuclear Information System (INIS)

    The purpose of this study was to construct a system that calculates mean glandular dose (MGD) in mammography in real-time on the radiology information system (RIS) network. Measurement of the half-value layer (HVL) and exposure dose were measured according to the Japanese mammographic quality control manual. A parallel plate chamber (10X5-6M; soft X-rays only) was used for measurement. Exposure dose was measured from 26 to 32 kV. Effective energy (Eeff [keV]) could be determined from tube voltage (V [kV]) using the measure of the HVL according to the following equations: for the Mo/Mo combination, Eeff=0.1325V+11.80; for the Mo/Rh combination, Eeff=0.1435V+12.20; for the Rh/Rh combination, Eeff=0.1724V+11.29. Exposure output (XmAs [mR/mAs]), which can be determined from dosimetry per 1 mAs, becomes the following equation if effective energy is expressed as a variable: for the Mo/Mo combination, XmAs=2.1329 Eeff2-57.784 Eeff+392.71; for the Mo/Rh combination, XmAs=1.1919 Eeff2-31.924 Eeff+212.23; and for the Rh/Rh combination, XmAs=2.6929 Eeff2-82.831 Eeff+643.54. The MGD conversion factor (DgN [mGy/mR]) can be determined from effective energy using the American College of Radiology (ACR) protocol according to the following equation: for the Mo/Mo combination, DgN=(0.3962 Eeff-4.3178)·10-3; for the Mo/Rh combination, DgN=(0.3495 Eeff-3.5479)·10-3; and for the Rh/Rh combination, DgN=(0.4498 Eeff-5.0448)·10-3. However, in these cases, compression breast thickness (CBT) was 4.2 cm, and the ratio of adipose and glandular tissue was 50/50. MGD can be determined using mAs obtained from mammography, exposure output (XmAs), MGD conversion factor (DgN), and source-skin distance compensation factor (SSDcf) according to the following equation: MGD [mGy]=mAs·XmAs [mR/mAs]·DgN [mGy/mR]· SSDcf where SSDcf={64/(64-CBT [cm]){2. (author)

  19. DETERMINACIÓN DE UN MÉTODO DE CALCULO DE DOSIS GLANDULAR PROMEDIO EN EXAMENES DE MAMOGRAFIA CONVENCIONAL DETERMINATION OF A METHOD FOR CALCULATING MEAN GLANDULAR DOSE IN CONVENTIONAL MAMMOGRAPHY EXAMS

    OpenAIRE

    Oswaldo Ramos N; Manuel Villarreal U

    2009-01-01

    Presentamos la aplicación de un modelo numérico para estimarla dosis glandular promedio en mamografía. Hemos utilizado un mamógrafo General Electric, tensión del tubo: 20-35 kV con incrementos de 1 kV; carga del tubo: 10-250 mAs; combinación ánodo-filtro de Molibdeno-Molibdeno. Durante dos meses datos de 162 exploraciones con proyecciones cráneo-caudal y medio lateral oblicua en ambas mamas. El espesor de mama comprimida se encuentra en el rango de 2,5 a 6,5 cm. Los rangos de dosis glandular ...

  20. Cistitis quística glandular presentada como cistopatía quística

    Directory of Open Access Journals (Sweden)

    Claudio Orlich-Castelán

    2015-03-01

    Full Text Available Se presenta el caso de una mujer de 73 años, con historia de hematuria macroscópica de aparición reciente, con presencia de quistes en toda la extensión de la mucosa vesical, y con diagnóstico por biopsias de vejiga, de una cistitis glandular. Se habla de cistopatía quística cuando los quistes se encuentran difusamente en la vejiga, y frecuentemente coexiste con lipomatosis pélvica en pacientes obesas, como la que reportada aquí. Es considerada una lesión premaligna y por eso es importante un seguimiento cuidadoso con cistoscopias periódicas. La cistitis quística se presenta más frecuentemente en hombres y en personas de mayor edad. Macroscópicamente, se manifiesta con nódulos submucosos únicos o múltiples, y los hallazgos histológicos son la presencia de nidos uroteliales redondeados, con dilatación quística dentro de la lámina propia, y paralelos a la superficie urotelial.

  1. Single-cell analysis of glandular T cell receptors in Sjögren’s syndrome

    Science.gov (United States)

    Joachims, Michelle L.; Leehan, Kerry M.; Lawrence, Christina; Pelikan, Richard C.; Moore, Jacen S.; Pan, Zijian; Rasmussen, Astrid; Radfar, Lida; Lewis, David M.; Grundahl, Kiely M.; Kelly, Jennifer A.; Wiley, Graham B.; Shugay, Mikhail; Chudakov, Dmitriy M.; Lessard, Christopher J.; Stone, Donald U.; Scofield, R. Hal; Montgomery, Courtney G.; Sivils, Kathy L.; Thompson, Linda F.; Farris, A. Darise

    2016-01-01

    CD4+ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren’s syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4+CD45RA− T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies. PMID:27358913

  2. Glandular odontogenic cyst mimicking ameloblastoma in a 78 year old female: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Do; Lee, Wan; Kwon, Kyung Hwan; Choi, Moon Ki; Choi, Eun Joo [College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Yoon, Jung Hoon [Dept. of Oral and Maxillofacial Pathology, College of Dentistry, Daejeon Dental Hospital, Wonkwang University, Daejeon (Korea, Republic of)

    2014-09-15

    Glandular odontogenic cyst (GOC) is a rare, potentially aggressive jaw lesion. The common radiographic features include a well-defined radiolucency with distinct borders, presenting a uni- or multilocular appearance. A cystic lesion in the posterior mandible of a 78-year-old female was incidentally found. Radiographs showed a unilocular lesion with a scalloped margin, external root resorption of the adjacent tooth, and cortical perforation. This lesion had changed from a small ovoid shape to a more expanded lesion in a period of four years. The small lesion showed unilocularity with a smooth margin and a well-defined border, but the expanded lesion produced cortical perforation and a lobulated margin. The provisional diagnosis was an ameloblastoma, whereas the histopathological examination revealed a GOC. This was a quite rare case, given that this radiographic change was observed in the posterior mandible of an elderly female. This case showed that a GOC can grow even in people in their seventies, changing from the unilocular form to an expanded, lobulated lesion. Here, we report a case of GOC with characteristic radiographic features.

  3. Mean glandular dose in six digital mammography services in Santiago, Chile: preliminary reference levels

    International Nuclear Information System (INIS)

    The purpose of this paper was to estimate mean glandular dose levels (DG) in six digital mammography systems in Santiago, Chile, and to propose preliminary reference levels to execute mammography in Chile. The study was carried out assessing two direct digital systems and four computer-based radiography (CR) systems. Estimates of DG were calculated for different thicknesses of polymethyl methacrylate according to the quality control protocol in digital mammography of the Spanish Society of Medical Physics and NHSBSP Equipment Report 0604 Version 3. DG values ranged between 0.64 and 7.26 mGy for a range of 20- to 70-mm thickness, respectively. Thirty-six per cent of DG was higher than the acceptable dose level and 100 % of DG was higher than the desirable level. It is therefore necessary to optimise doses. The initial proposal to establish dose reference levels for DG would range between 0.90 and 6.40 mGy for a thickness range of 20 to 70 mm. (authors)

  4. Crypto-glandular fistulous paraproctites--is the surgical prophylaxis of reccurences imperative?

    Science.gov (United States)

    Radionov, M; Ziya, D D; Sechanov, I

    2013-01-01

    It is done an analysis of 191 patients operated on for crypto-glandular chronic fistulous paraproctitis. The age of the patients vary 21 to 76 years and the male:female proportion is 2,25 to 1. In 164 patients it was first operation for fistula-in-ano and in 27 cases it was a consecutive one for reccurence. There was intervened a concomitant other disease of the anal channel which pathogenetically predispose the development of fistula in 54 (28%) cases. The patients were discharged 1-3 days after surgery. Ambulant control and ligature procedures up to the 30th day were done. A follow up was done of 118 patients (68%) for period of 3 to 12 months. In all the followed up patients was registered full continence and good tonus of the anal sphincters. Recurrences were registered in 8 cases with fibrin glue occlusion of the fistula. There are no registered cases of recurrences by the followed up patients after fistulotomy and excision-ligature methods. The authors review in the discussion the pathogenetical predisposition for paraproctitis in consequence of other diseases of the anal channel and the necessity of surgical prophylaxis of recurrences. PMID:23847806

  5. Preliminary Studies into the Determination of Mean Glandular Dose During Diagnostic Mammography Procedure in Ghana

    Directory of Open Access Journals (Sweden)

    Irene Nsiah-Akoto

    2011-08-01

    Full Text Available The objective of this project was to determine the mean glandular dose (MGD from Craniocaudal (CC and Mediolateral Oblique (MLO views to the breast during diagnostic mammography and the total dose per woman. The study was conducted at the Mammography Unit of Komfo Anokye Teaching Hospital and Peace and Love Hospital, Oduom. Data such as age, weight, height, bust size, compressed breast thickness, time of exposure, milli-ampere second (mAs, kilovoltage peak (KVp and half value layer (HVL were recorded from 440 films from 110 women. The MGD per film was 1.17± 0.02 mGy and 1.25±0.03 mGy for the craniocaudal (CC and mediolateral oblique (MLO views, respectively. The mean MGD per woman was 1.80±0.03mGy. The only factors that were found to affect MGD were mAs and the compressed breast thickness. No significant relationships were seen between MGD per woman with respect to ethnicity and educational background. The dose values obtained fall within the internationally acceptable dose range of 1-3 mGy. This suggests mammography x-ray generators at the two hospitals are capable of achieving acceptable dose levels for patient safety and this prompted us to rule out the fact that all other factors considered, they are not at risk of induced cancer from mammography.

  6. Characterization of contrast - to noise ration and mean glandular dose for digital mammography system in Tanzania

    International Nuclear Information System (INIS)

    The aim of this study was to investigate if the current exposure parameters in clinical use at sole CR mammography facility in Tanzania are optimal. For this purpose, the European protocol for quality control in mammography screening was applied to characterize the contrast-to-noise ratio (CNR) and mean glandular dose (D) values of model iCR3600 with iCRco image plates (RADIEQ: South Korea). The characterization was performed at 30 kVp under manual mode exposure conditions for standard PMMA phantom thicknesses ranging from 20 to70 mm. The figure of merit (FOM) expressed in terms of CNR2/MGD was derived to assess the level of optimization. The results show that FOM was highest 30 cm PMMA thickness and roughly decreased with increasing 11 PMMA thickness as expected. The D values were 0.7, 0.81, 0.69, 0.7, 0.74, 0.64 and 0.56 mGy for 20, 30, 40, 45, 50, 60 and 70 mm PMMA respectively. The dose values were much lower than the European limiting values. Although there is no evidence for deteriorated image quality as a result of low dose levels, non use of automatic exposure control device suggest the need for improvement. As a starting point, the defective automatic exposure system should be repaired and put in practice followed by comprehensive optimization studies. Therefore further studies may be necessary for conclusive optimization status (author)

  7. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Directory of Open Access Journals (Sweden)

    Allison L Speer

    Full Text Available The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10 and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b, in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22 except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  8. Loss of vitamin D receptor signaling from the mammary epithelium or adipose tissue alters pubertal glandular development

    OpenAIRE

    Johnson, Abby L.; Zinser, Glendon M.; Waltz, Susan E.

    2014-01-01

    Vitamin D3 receptor (VDR) signaling within the mammary gland regulates various postnatal stages of glandular development, including puberty, pregnancy, involution, and tumorigenesis. Previous studies have shown that vitamin D3 treatment induces cell-autonomous growth inhibition and differentiation of mammary epithelial cells in culture. Furthermore, mammary adipose tissue serves as a depot for vitamin D3 storage, and both epithelial cells and adipocytes are capable of bioactivating vitamin D3...

  9. The capital budgeting manual

    OpenAIRE

    Segelod, Esbjörn

    1995-01-01

    There has been very many postal surveys of capital budgeting practice, but almost no studies of the written routines that fix the practice of those groups that use a capital budgeting manual. This article fills this vacuum by describing and analysing the capital budgeting manuals used by major Swedish groups, most of whom are multinationals. Changes in the manuals during the last 30 years are studied using hvo earlier Swedish studies of manuals from the 60’s and 70’s. Comparisons are made wit...

  10. Capital Humano y Productividad

    OpenAIRE

    Ángel de la Fuente

    2015-01-01

    Este trabajo contiene un breve panorama de la literatura empírica sobre capital humano y productividad y resume los resultados de mi propio trabajo sobre el tema. En conjunto, la evidencia disponible sugiere que la inversión en educación tiene un efecto positivo, significativo y cuantitativamente importante sobre el crecimiento de la productividad. De acuerdo con mis estimaciones, además, la rentabilidad social de la inversión en capital humano es mayor que la del capital físico en la mayor p...

  11. The alveolar epithelial differentiation of glandular inner lining cells in a mucoepidermoid carcinoma of the lung: a case report

    Directory of Open Access Journals (Sweden)

    Xu Hong-Tao

    2012-10-01

    Full Text Available Abstract Mucoepidermoid carcinoma is a common malignant epithelial tumor of salivary glands, but relatively rare in lung. The histological features of mucoepidermoid carcinoma of the lung are similar to its counterpart arising from the salivary glands. Here, we reported a special tumor that occurred in the medial segment of the right lower lobe in a 22-year-old man. This tumor exhibited typical features of mucoepidermoid carcinoma with 3 cell types: squamoid cells, mucin-secreting cells and cells of intermediate type. These 3 types of cells organized into cysts, nests, glands and solid patterns. Specially, the inner lining cells of some glandular structures were uniform cuboidal and hobnail-like, similar to the alveolar epithelial cells. Immunohistochemistry staining revealed that the inner lining cells of glandular structures were positive for thyroid transcription factor-1 and surfactant protein-B, used as markers of alveolar epithelial cells, and were negative for p63. These findings for the first time demonstrated a rare alveolar epithelial differentiation of glandular inner lining cells in a mucoepidermoid carcinoma of the lung. Virtual Slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7095988968057804

  12. Estimation of mean glandular dose for breast tomosynthesis: factors for use with the UK, European and IAEA breast dosimetry protocols

    International Nuclear Information System (INIS)

    A formalism is proposed for the estimation of mean glandular dose for breast tomosynthesis, which is a simple extension of the UK, European and IAEA protocols for dosimetry in conventional projection mammography. The formalism introduces t-factors for the calculation of breast dose from a single projection and T-factors for a complete exposure series. Monte Carlo calculations of t-factors have been made for an imaging geometry with full-field irradiation of the breast for a wide range of x-ray spectra, breast sizes and glandularities. The t-factors show little dependence on breast glandularity and tables are provided as a function of projection angle and breast thickness, which may be used for all x-ray spectra simulated. The T-factors for this geometry depend upon the choice of projection angles and weights per projection, but various example calculations gave values in the range 0.93-1.00. T-factors are also provided for the Sectra tomosynthesis system, which employs a scanned narrow-beam imaging geometry. In this quite different configuration, the factor (denoted TS) shows an important dependence on breast thickness, varying between 0.98 and 0.76 for 20 and 110 mm thick breasts, respectively. Additional data are given to extend the current tabulations of g-, c- and s-factors used for dosimetry of conventional 2D mammography.

  13. Breast cancer and ductal carcinoma in situ among women with prior squamous or glandular precancer in the cervix: a register-based study

    OpenAIRE

    B. T. Hansen; Nygård, M.; Falk, R S; Hofvind, S

    2012-01-01

    Background: Human papillomavirus and hormonal contraceptives may be risk factors for cervical precancer and malignant breast tumours. Methods: Standardised incidence ratios (SIRs) of malignant breast tumours during 1970–2008 were estimated separately for women with prior squamous and glandular cervical precancer. Results: Women with squamous precancer and women with glandular precancer in the cervix had a significantly higher risk of malignant breast tumours than the general female population...

  14. On capital gain taxation

    OpenAIRE

    Anton Miglo

    2008-01-01

    This note provides an explanation for why tax rates on capital gains are usually lower than ordinary income tax rates based on manager's agency problem related to "empire-building" or the underinvestment problem.

  15. Capital Projects Application (CPA)

    Data.gov (United States)

    General Services Administration — Capital Projects application (CPA) provides users with the ability to maintain project related financial data for Budget Activity (BA) 51, 55, 64, 01, 02, 03, 04....

  16. Cultural Capital Today

    DEFF Research Database (Denmark)

    Prieur, Annick; Skjøtt-Larsen, Jakob; Rosenlund, Lennart

    2008-01-01

    Based on Danish survey data subjected to correspondence analysis, this article aims at carrying out a critical assessment of Pierre Bourdieu's theory of social differentiation in advanced societies as a multi-dimensional phenomenon. As his theory goes, capital volume (economic + cultural capital......) and capital composition (the relative weight of the two) are the main dimensions of social differentiation, which structure the space of social positions as well as the space of lifestyles. The central discussion of the article concerns the character of cultural capital, and the role it plays in the formation...... of social divisions. This leads to a discussion of four core questions: first, are there signs of a strong individualism and, correspondingly, a weak social structuring of lifestyles? The study does not find support for this view. Second, does classical highbrow culture play a central role as a marker...

  17. HUMAN CAPITAL INVESTMENT

    Directory of Open Access Journals (Sweden)

    Ph. D. Student Ioana - Julieta Josan

    2012-05-01

    Full Text Available Once with the development of the human capital theory, the education received an economic value. Leading theorists and specialists in the field have shown that the remarkable economic effects of the investments in education influence the chances of acquiring a job and earnings, demonstrating how the theory justifies such an investment. At the hand, the allocation of resources in human capital brings performance and benefits to companies investing in their employees. Also, the investment in human capital is strategic for any country that seeks to create a knowledge economy. Considering the above arguments, the aim of this paper is to highlight the characteristics of investment in human capital, the types of investment, the factors of education investment and the entities interested in investing and their benefits.

  18. Thin Capitalization Rules and Multinational Firm Capital Structure

    OpenAIRE

    Blouin, J.; Huizinga, H.P.; Laeven, L.; Nicodeme, G.

    2014-01-01

    This paper examines the impact of thin capitalization rules that limit the tax deductibility of interest on the capital structure of the foreign affiliates of US multinationals. We construct a new data set on thin capitalization rules in 54 countries for the period 1982-2004. Using confidential data on the (internal) leverage of foreign affiliates of US multinationals, we find that thin capitalization rules affect multinational firm capital structure in a significant way. Specifically, restri...

  19. Capital mobility, tax competition, and lobbying for redistributive capital taxation

    OpenAIRE

    Lorz, Jens Oliver

    1996-01-01

    This paper analyzes the impact of international capital mobility on redistributive capital taxation and on lobbying activities by interest groups. It employs a model where different capital endowments lead to a conflict between households concerning their most preferred capital tax rate. Three main results are derived: First, redistributive source based capital taxes or subsidies decline as international tax competition intensifies. Second, lobbying activities of certain interest groups may e...

  20. Cultural capital and demand

    OpenAIRE

    Victoria Ateca - Amestoy

    2007-01-01

    In this paper we develop a theoretical model that investigates the demand for cultural goods under the assumption of cultural capital and rational addiction. We also consider the effect of a policy intervention in order to raise the initial stock of cultural capital of a given individual, both on individual demand and on supply. Finally, we discuss on the effectiveness of such policies by translating our model to a dynamic framework.

  1. Religion, Science and Capitalisms

    OpenAIRE

    Rehbein, Boike

    2014-01-01

    This paper enquires into the relation between capitalism, religion and the philosophy of science. We would tend to suppose that there are only superficial and accidental links between them. A closer analysis reveals, however, that the epistemology of contemporary science is still based on a certain interpretation of Christianity and linked to a particular type of capitalism. Science developed after Galileo and Descartes aims at universal truth but was founded on the notion of the Christian ...

  2. Embodied human capital unemployment

    OpenAIRE

    Kumaraku, Klajdi; Naqvi, Nadeem; Rexhepi, Sara

    2011-01-01

    Adam Smith (1776) devoted the first three chapters to the division of labor in his Inquiry into the Nature and Causes of the Wealth of Nations. This process, carried far enough, eventually results in a divergence between the distributions of supplies and demands of such horizontally-differentiated distinct types of human capital embodied in different persons, leading to the emergence of Embodied Human Capital Unemployment. We illustrate the relevance of this new concept of unemployment to the...

  3. Social Capital and Conflict

    OpenAIRE

    Alia Aghajanian

    2012-01-01

    Conflict is either caused by, or brings about, drastic changes in the underlying social relationships between members of a community involved in the conflict. The conflict literature has taken note, and a growing number of studies attempt to determine the relationship between conflict and social capital. Unfortunately, there are many problems that have plagued the social capital literature, and conflict studies have failed to address these. This paper aims to provide a critical analysis of th...

  4. Empreendedorismo na capital amazonense

    OpenAIRE

    Filho, Aécio Flávio Ferreira da Silva

    2010-01-01

    This research was elaborated to evaluate entrepreneurship in the Capital of the Amazon State, Brazil. Its relevance is due to the non-existent literature in the subject of entrepreneurship, in the Northern Region of Brazil. The available Brazilian literary archive comprehends only the main cities located in the Southern and Northeastern Regions of the country. There is no research in the Northern Region – where the Amazon State and its Capital, Manaus, are found – and thus lies the reason for...

  5. The global capital leviathan

    OpenAIRE

    Robinson, William I.

    2011-01-01

    The money mandarins of global capitalism and their political agents are utilizing the global crisis to impose brutal austerity and attempting to dismantle what is left of welfare systems and social states in Europe, North America and elsewhere. The budgetary and fiscal crises that supposedly justify spending cuts and austerity are contrived. They are a consequence of the unwillingness or inability of states to challenge capital and their disposition to transfer the burden of the crisis to wor...

  6. Entrepreneurship and heterogeneous capital

    OpenAIRE

    Foss, Nicolai J.; Klein, Peter G.

    2008-01-01

    Entrepreneurship is ultimately about the arrangement of resources into productive activi-ties. Much of the entrepreneurship literature, however, has focused on the demand side of the market. While resource heterogeneity is a feature of many theories of the firm, such theories are not built on a systematic theory of capital. We show how the approach to capital developed by the Austrian school of economics provides a natural bridge between theory of entrepreneurship and the theory of the firm. ...

  7. Venture capital and internationalization

    OpenAIRE

    Schertler, Andrea; Tykvová, Tereza

    2009-01-01

    Cross-border investments represent a substantial share of venture capital activities. We use a new and comprehensive dataset on worldwide investments to analyze the internationalization of venture capital financing. Our results from the perspectives of (i) venture capitalists, (ii) portfolio companies, (iii) portfolio companies' countries and (iv) pairs of venture capitalists' and portfolio companies' countries suggest that some factors, such as viable stock markets, boost investments by dome...

  8. Measuring Natural Capital

    OpenAIRE

    Dariana Tani

    2014-01-01

    The purpose of this paper is to highlight the importance of establishing a system of natural capital accounting. Natural capital is integral to the economy and yet it is routinely taken for granted because the goods and services it provides are generally freely available. The consequence is that without prices, these resources are not being allocated efficiently within the economy and opportunities for significant gains in well-being and the possibility of long-term future growth are being lo...

  9. Measuring Social Capital

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Bjørnskov, Christian

    2007-01-01

    How to construct a robust measure of social capital? This paper contains two contributions. The first is an attempt to establish a broad social capital measure based on four indicators, the Freedom House Index, an index of perceived corruption from Transparency International, and scores on civic ...... serve as institutional models for countries and regions aiming to increase their future level of social capital. More rigorous empirical research is needed within this field.......How to construct a robust measure of social capital? This paper contains two contributions. The first is an attempt to establish a broad social capital measure based on four indicators, the Freedom House Index, an index of perceived corruption from Transparency International, and scores on civic...... participation and generalized trust. This measure is then applied by comparing the level of social capital in 25 countries from Western and Eastern Europe. Our nine cluster analysis shows that Switzerland has the highest score, followed by the Netherlands and Scandinavia. At the other end of the continuum we...

  10. The Performance of Intellectual Capital

    DEFF Research Database (Denmark)

    Murthy, Vijaya; Mouritsen, Jan

    2011-01-01

    Purpose – This paper aims to analyse the relationship between intellectual capital and financial capital using a case study. This makes it possible to discuss how intellectual capital is related to value creation with a degree of nuance that is absent from most statistical studies of relationships...... between human, organisational, relational and financial capital. Design/methodology/approach – The paper uses a case study of a firm that invests in intellectual capital in order to develop financial capital. It traces the relationship between intellectual capital elements and financial capital via...... interviews. This allows the development of a nuanced account of the performance of intellectual capital. This account questions the universality of the linear model typically found in statistical studies. The model makes it possible to show how items of intellectual capital not only interact but also compete...

  11. Entrepreneurs’ human and social capital

    DEFF Research Database (Denmark)

    Rezaei, Shahamak; Schøtt, Thomas; Ashourizadeh, Shayegheh;

    2014-01-01

    It is widely acknowledged that entrepreneurs' human capital in form of education and social capital in form of networking are mutually beneficial and also that both human and social capital benefit their performance. Here, the hypothesis is that human and social capital, in combination, provide......, that human capital and social capital (specifically networking in the international environment, work-place, professions and market, but not in the private sphere) both benefit export directly and that human capital amplifies the benefit of social capital, especially through international networking....... added value and jointly add a further boost to performance, specifically if the form of exporting. Global Entrepreneurship Monitor provides data on 52,946 entrepreneurs, who reported on exporting and networking for advice. Hierarchical linear modelling shows that human capital promotes social capital...

  12. Oncoplastic Resection of Retroareolar Breast Cancer: Central Quadrantectomy and Reconstruction by Local Skin-Glandular Flap

    International Nuclear Information System (INIS)

    Background: Patients with central breast neoplasms account for 5 to 20% of breast cancer cases and, for a long time, they have been denied Breast Conservation Surgery (BCS) and conventionally treated with mastectomy. The high incidence of Nipple-Areola-Complex (NAC) involvement usually associated with these tumors necessitates nipple and areolar resection together with an adequate safety margin around the tumor, which yields an unacceptable cosmetic result. With the help of Oncoplastic Surgical Techniques, BCS can be offered to these patients. In this study central quadrantectomy and breast reconstruction by an infero-Iaterally based pedicled flap were evaluated. Patients and Methods: This study comprised 23 women with central breast tumors treated at the National Cancer Institute (NC]), Cairo University and at the Aswan Cancer Center, Egyptian Ministry of Health. Their ages ranged from 31 to 62 years (mean: 48.4±10.2 years). Twenty-two had a palpable mass, while only I had Paget's disease of the nipple without mass. The size of their tumors ranged from 4 to 33mm (mean: 16.9±8.6mm). Only 9 women showed clinical suspicion of NAC involvement in the form of nipple retraction. Seventeen cases had their tumors strictly in the retro-areolar region, while 5 had tumors extending for a maximum of I.5Cm beyond the areolar edge. All patients underwent central quadrantec-tomy with NAC resection removing a cylinder of breast tissue reaching down to the pectoral muscle together with axillary dissection. Advancement of an infero-Iaterally based skin-glandular flap was then carried out. All patients received adjuvant radiotherapy with or without chemotherapy or hormonal therapy. Results: Fourteen patients showed pathological evidence of nipple infiltration (60.8%). The free safety margin (SM) ranged from 9 to 13mm (mean: 10. 0.9mm). This could be accomplished from the first attempt in 18 patients; however, in 5 patients a second wider excision was needed to obtain an adequate

  13. SU-E-I-04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pineda, E; Ruiz-Trejo, C; E, Brandan M [Instituto de Fisica UNAM, Mexico City, DF (Mexico)

    2014-06-01

    Purpose: To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert. Methods: The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD-100 chips, some under Al foils, to determine air kerma and half-value-layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1). Results: MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full-field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR). Conclusion: The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography.

  14. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    Science.gov (United States)

    Bouwman, R. W.; van Engen, R. E.; Young, K. C.; den Heeten, G. J.; Broeders, M. J. M.; Schopphoven, S.; Jeukens, C. R. L. P. N.; Veldkamp, W. J. H.; Dance, D. R.

    2015-10-01

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last decades the automatic exposure control (AEC) increased in complexity and became more sensitive to (local) differences in breast composition. The question is how well the AGD estimated using these simple dosimetry phantoms agrees with the average patient AGD. In this study the AGDs for both dosimetry phantoms and for patients have been evaluated for 5 different x-ray systems in DM and DBT modes. It was found that the ratios between patient and phantom AGD did not differ considerably using both dosimetry phantoms. These ratios averaged over all breast thicknesses were 1.14 and 1.15 for the PMMA and PMMA-PE dosimetry phantoms respectively in DM mode and 1.00 and 1.02 in the DBT mode. These ratios were deemed to be sufficiently close to unity to be suitable for dosimetry evaluation in quality control procedures. However care should be taken when comparing systems for DM and DBT since depending on the AEC operation, ratios for particular breast thicknesses may differ substantially (0.83-1.96). Although the predictions of both phantoms are similar we advise the use of PMMA  +  PE slabs for both DM and DBT to harmonize dosimetry protocols and avoid any potential issues with the use of spacers with the PMMA phantoms.

  15. SU-E-I-04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality

    International Nuclear Information System (INIS)

    Purpose: To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert. Methods: The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD-100 chips, some under Al foils, to determine air kerma and half-value-layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1). Results: MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full-field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR). Conclusion: The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography

  16. Results of a 2011 national questionnaire for investigation of mean glandular dose from mammography in Japan

    International Nuclear Information System (INIS)

    Diagnostic reference levels (DRLs) for mammography have yet to be created in Japan. A national questionnaire investigation into radiographic conditions in Japan was carried out for the purpose of creating DRLs. Items investigated included the following: tube voltage; tube current; current–time product; source–image distance; craniocaudal view; automatic exposure control (AEC) settings; name of mammography unit; image receptor system (computed radiography (CR), flat panel detector (FPD), or film/screen (F/S)); and supported or unsupported monitor diagnosis (including monitor resolution). Estimation of the mean glandular dose (MGD) for mammography was performed and compared with previous investigations. The MGD was 1.58(0.48) mGy, which did not significantly differ from a 2007 investigation. In relation to image receptors, although no difference in average MGD values was observed between CR and FPD systems, F/S systems had a significantly decreased value compared to both CR and FPDs. Concerning digital systems (FPDs), the MGD value of the direct conversion system was significantly higher than the indirect conversion system. No significant difference in MGD value was evident concerning type of monitor diagnosis for either the CR or the FPD digital systems; however, hard copies were used more often in CR. No significant difference in the MGD value was found in relation to monitor resolution. This report suggests ways to lower the doses patients undergoing mammography receive in Japan, and serves as reference data for 4.2 cm compressed breast tissue of 50% composition DRLs. Furthermore, our findings suggest that further optimisation of FPD settings can promote a reduction in the MGD value. (paper)

  17. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    International Nuclear Information System (INIS)

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last decades the automatic exposure control (AEC) increased in complexity and became more sensitive to (local) differences in breast composition. The question is how well the AGD estimated using these simple dosimetry phantoms agrees with the average patient AGD. In this study the AGDs for both dosimetry phantoms and for patients have been evaluated for 5 different x-ray systems in DM and DBT modes. It was found that the ratios between patient and phantom AGD did not differ considerably using both dosimetry phantoms. These ratios averaged over all breast thicknesses were 1.14 and 1.15 for the PMMA and PMMA-PE dosimetry phantoms respectively in DM mode and 1.00 and 1.02 in the DBT mode. These ratios were deemed to be sufficiently close to unity to be suitable for dosimetry evaluation in quality control procedures. However care should be taken when comparing systems for DM and DBT since depending on the AEC operation, ratios for particular breast thicknesses may differ substantially (0.83–1.96). Although the predictions of both phantoms are similar we advise the use of PMMA  +  PE slabs for both DM and DBT to harmonize dosimetry protocols and avoid any potential issues with the use of spacers with the PMMA phantoms. (paper)

  18. Mean glandular doses for women undergoing mammographic breast screening in Oyo state, Nigeria

    International Nuclear Information System (INIS)

    In this work, thermoluminescent dosimeters have been used to measure entrance surface doses (ESDs) of patients undergoing mammographic screening at the University College Hospital, Ibadan, Oyo state. The mean glandular doses (MGDs) were also calculated using the measured ESDs. The results showed that the ESDs ranged from 0.26 mGy to 21.26 mGy for the mediolateral oblique (MLO) views and 0.08 mGy to 5.36 mGy for the craniocaudal (CC) views. The calculated MGD ranged from 0.07 mGy to 3.57 mGy for the MLO views and 0.02 mGy to 0.98 mGy for the CC views. The possible reasons for the large variations in the individual ESD values and MGD values for both views are discussed using patients' data, equipment specific data and the technical parameters used for the examinations. Comparison showed that the mean ESD values and MGD values reported in this work are below published values. The mean of the calculated MGD values is also found to be lower than the recommended guidance level of 3.0 mGy when using grid. 92.5% of the patients had MGD values that are less than 2.5 mGy, hence a national reference MGD value of 2.5 mGy is proposed for Nigeria. Implementation of a dose reduction program in mammographic screening is also suggested because of the observed large variations in patients MGD values.

  19. A computational approach to resolve cell level contributions to early glandular epithelial cancer progression

    Directory of Open Access Journals (Sweden)

    Park Sunwoo

    2009-12-01

    Full Text Available Abstract Background Three-dimensional (3D embedded cell cultures provide an appropriate physiological environment to reconstruct features of early glandular epithelial cancer. Although these are orders of magnitude simpler than tissues, they too are complex systems that have proven challenging to understand. We used agent-based, discrete event simulation modeling methods to build working hypotheses of mechanisms of epithelial 3D culture phenotype and early cancer progression. Starting with an earlier software analogue, we validated an improved in silico epithelial analogue (ISEA for cardinal features of a normally developed MDCK cyst. A set of axiomatic operating principles defined simulated cell actions. We explored selective disruption of individual simulated cell actions. New framework features enabled recording detailed measures of ISEA cell activities and morphology. Results Enabled by a small set of cell operating principles, ISEA cells multiplied and self-organized into cyst-like structures that mimicked those of MDCK cells in a 3D embedded cell culture. Selective disruption of "anoikis" or directional cell division caused the ISEA to develop phenotypic features resembling those of in vitro tumor reconstruction models and cancerous tissues in vivo. Disrupting either process, or both, altered cell activity patterns that resulted in morphologically similar outcomes. Increased disruption led to a prolonged presence of intraluminal cells. Conclusions ISEA mechanisms, behaviors, and morphological properties may have biological counterparts. To the extent that in silico-to-in vitro mappings are valid, the results suggest plausible, additional mechanisms of in vitro cancer reconstruction or reversion, and raise potentially significant implications for early cancer diagnosis based on histology. Further ISEA development and use are expected to provide a viable platform to complement in vitro methods for unraveling the mechanistic basis of

  20. Trade Barriers on Capital Goods

    OpenAIRE

    VURAL, Gülfer

    2015-01-01

    Capital goods play a major role in international trade. World production of capital goods and R&D activity are highly concentrated in some developed countries. Most of the countries, especially developing countries import the most of their capital equipment from some leading capital goods exporter countries. Therefore technological advances can be transmitted across borders through trade in capital goods. In international trade countries face trade costs. Trade costs can be in the form of...

  1. Communication Capital Productivity: National Aspect

    OpenAIRE

    Naumik Ekaterina G.

    2012-01-01

    The article offers suggestions for assessing communication capital productivity; the contradictions that affect the value of the communication efficiency of capital (the union of the agents of the market of communication services and products allows them to increase the communication capital productivity and to decrease communication capital productivity of competitors) are formulated; the dependence of productivity on the number of communication capital customers of the communication network...

  2. Social Capital Access and Entrepreneurship

    OpenAIRE

    Stefan Bauernschuster; Oliver Falck; Stephan Heblich

    2010-01-01

    We investigate the effect of social capital access on entrepreneurship. Social capital helps entrepreneurs to overcome resource constraints. This is especially important in small communities where we often see a lack of market-oriented institutions such as venture capital firms. Entrepreneurs gain access to social capital via club memberships. Combining differences in the number of individual club memberships with differences in the importance of social capital across communities, we identify...

  3. Human capital and optimal positive taxation of capital Income

    OpenAIRE

    Jacobs, B.; Bovenberg, A.L.

    2005-01-01

    This paper analyzes optimal linear taxes on capital and labor incomes in a life-cyclemodel of human capital investment, financial savings, and labor supply with heteroge-nous individuals. A dual income tax with a positive marginal tax rate on not onlylabor income but also capital income is optimal. The positive tax on capital incomeserves to alleviate the distortions of the labor tax on human capital accumulation.The optimal marginal tax rate on capital income is lower than that on labor inco...

  4. Organizational networks and social capital

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Waldstrøm, Christian

    2013-01-01

    This chapter presents a framework for understanding organizational networks and social capital through the lens of “social capital ownership” as well as the private and collective goods provided through this ownership. More specifically, it argues that ownership of social capital in organizations...... is closely connected to four types of social capital – two belonging to the bridging social capital type, and two belonging to the bonding social capital type. The chapter first reviews literature on organizational social capital and then directly focuses on ownership of social capital in organizations......, as well as the derived benefits, or losses. Next, the chapter presents an empirical case apt to illustrate the theoretical findings in part one, namely the nineteenth-century Danish Cooperative Dairy Movement (Svendsen and Svendsen 2004). It is demonstrated how social capital among Danish peasants...

  5. Risk capital allocation

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Smilgins, Aleksandrs

    sum of the risks of the individual sub-units. The question is how to allocate the risk capital of the company among the subunits in a fair way. In this paper we propose to use the Lorenz set as an allocation method. We show that the Lorenz set is operational and coherent. Moreover, we propose a set of......Risk capital allocation problems have been widely discussed in the academic literature. We consider a company with multiple subunits having individual portfolios. Hence, when portfolios of subunits are merged, a diversification benefit arises: the risk of the company as a whole is smaller than the...... new axioms related directly to the problem of risk capital allocation and show that the Lorenz set satisfies these new axioms in contrast to other well-known coherent methods. Finally, we discuss how to deal with non-uniqueness of the Lorenz set....

  6. Validation of mean glandular dose values provided by a digital breast tomosynthesis system in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Beraldo O, B.; Paixao, L.; Donato da S, S. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Post-graduation in Sciences and Technology of Radiations Minerals and Materials, Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte (Brazil); Araujo T, M. H. [Dr Maria Helena Araujo Teixeira Clinic, Guajajaras 40, 30180-100 Belo Horizonte (Brazil); Nogueira, M. S., E-mail: bbo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte (Brazil)

    2014-08-15

    Digital breast tomosynthesis (DBT) is an emerging imaging modality that provides quasi-three-dimensional structural information of the breast and has strong promise to improve the differentiation of normal tissue and suspicious masses reducing the tissue overlaps. DBT images are reconstructed from a sequence of low-dose X-ray projections of the breast acquired at a small number of angles over a limited angular range. The Ho logic Selen ia Dimensions system is equipped with an amorphous Selenium (a-Se) detector layer of 250 μm thickness and a 70 μm pixel pitch. Studies are needed to determine the radiation dose of patients that are undergoing this emerging procedure to compare with the results obtained in DBT images. The mean glandular dose (D{sub G}) is the dosimetric quantity used in quality control of the mammographic systems. The aim of this work is to validate D{sub G} values for different breast thicknesses provided by a Ho logic Selen ia Dimensions system using a DBT mode in comparison with the same results obtained by a calibrated 90 X 5-6M-model Radcal ionization chamber. D{sub G} values were derived from the incident air kerma (K{sub i}) measurements and tabulated conversion coefficients that are dependent on the half value layer (HVL) of the X-ray spectrum. Voltage and tube loading values were recorded in irradiations using W/Al anode/filter combination, automatic exposure control mode and polymethyl methacrylate (PMMA) slabs which simulate different breast thicknesses. For K{sub i} measurements, the ionization chamber was positioned at 655 mm from the focus and the same radiographic technique values were selected with the manual mode. D{sub G} values for a complete procedure ranged from 0.9 ± 0.1 to 3.7 ± 0.4 mGy. The results for different breast thicknesses are in accordance with values obtained by DBT images and with acceptable levels established by the Commission of the European Communities (Cec) and the International Atomic Energy Agency (IAEA

  7. Papel da 2-tridecanona e dos tricomas glandulares tipo VI na resistência do tomateiro a Tuta absoluta

    Directory of Open Access Journals (Sweden)

    Gilardón Elsa

    2001-01-01

    Full Text Available O metabólito secundário 2-tridecanona, secretado pelos tricomas glandulares tipo VI das folhas de tomateiro silvestre, Lycopersicon hirsutum L., confere-lhe resistência a uma grande variedade de insetos, inclusive a traça-do-tomateiro, Tuta absoluta (Meyrick. O objetivo do trabalho foi avaliar a concentração de 2- tridecanona, a densidade de tricomas glandulares tipo VI e o grau de infestação da traça-do-tomateiro na cultivar suscetível 'Uco Plata' (Lycopersicon esculentum Mill., na linhagem resistente PI 134417 (L. hirsutum f. glabratum e em suas progênies F1 e F2. Foram avaliadas ainda as possíveis associações entre a concentração de 2-tridecanona, a densidade de tricomas glandulares tipo VI e o grau de infestação da traça-do-tomateiro. O grau médio de infestação da traça-do-tomateiro em 'Uco Plata' foi significativamente superior ao obtido em PI 134417. Ainda que a concentração de 2-tridecanona tenha sido significativamente superior no parental resistente, a presença deste metabólito somente explicaria parcialmente a resistência (R² = 8,17%. Não se detectaram diferenças significativas na densidade de tricomas tipo VI entre o parental suscetível e o resistente. Este comportamento ocorreu independentemente do conteúdo de 2-tridecanona e do grau de infestação da traça-do-tomateiro.

  8. Bank Capital Management

    OpenAIRE

    Jokipii, T.K.

    2009-01-01

    The work undertaken in this study empirically explores the determinants of regulatory bank capital bu®ers, and how they in°uence bank decisions. Focusing on bank capital management under the Basel I framework, this thesis serves to address some of the con- cerns that have been voiced regarding the implementation of the new regulation (Basel II) and the broader economic e®ects that could result. In particular, the research chapters of this thesis examine the cyclical behavior of European bank ...

  9. Governing Global Capital

    DEFF Research Database (Denmark)

    Harrington, Brooke

    in helping elites avoid taxes and other forms of regulation. The study documents how the means through which they achieve this objective - shifting billions in private capital wealth between Asia, Africa, India and Europe - and how this affects the balance of regional economic power. Drawing from an...... institutionalist perspective, the paper examines three ways in which wealth managers, both individually and through their professional society, influence regional competition for power and wealth: 1) by finding loopholes in existing policies that limit the global flow of capital; 2) by lobbying national and...

  10. Five models of capitalism

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Bresser-Pereira

    2012-03-01

    Full Text Available Besides analyzing capitalist societies historically and thinking of them in terms of phases or stages, we may compare different models or varieties of capitalism. In this paper I survey the literature on this subject, and distinguish the classification that has a production or business approach from those that use a mainly political criterion. I identify five forms of capitalism: among the rich countries, the liberal democratic or Anglo-Saxon model, the social or European model, and the endogenous social integration or Japanese model; among developing countries, I distinguish the Asian developmental model from the liberal-dependent model that characterizes most other developing countries, including Brazil.

  11. Capital Structure and Assets

    DEFF Research Database (Denmark)

    Flor, Christian Riis

    2008-01-01

    This paper analyzes a firm's capital structure choice when assets have outside value. Valuable assets implicitly provide a collateral and increase tax shield exploitation. The key feature in this paper is asset value uncertainty, implying that it is unknown ex ante whether the equity holders ex...... post optimally sell the assets or re-optimize the capital structure. Ex ante, more uncertain asset value decreases leverage, but not firm value, and selling the assets becomes less likely. Firms should tend to invest in assets whose value is less correlated to changes in earnings and, in addition...

  12. Randomized study of gefitinib versus pemetrexed as maintenance treatment in patients with advanced glandular non-small cell lung cancer

    OpenAIRE

    Xu, Yan-Hua; Mei, Jing-Song; Zhou, Juan

    2015-01-01

    Gefitinib was compared with pemetrexed as maintenance therapy in Patients with Advanced Glandular Non-small Cell Lung Cancer, mainly regarding clinical effect and side effect. A randomized trial of pemetrexed as study group (500 mg/m2, dl) versus gefitinib as the control group [250 mg on night 1, 250 mg on morning 2 (every day)] was conducted in 188 patients, 94 cases in each group with a therapy cycle of 21 days. In addition, the study group was also treated with folic acid, vitB12 and dexam...

  13. The Characterization of SaPIN2b, a Plant Trichome-Localized Proteinase Inhibitor from Solanum americanum

    Directory of Open Access Journals (Sweden)

    Zeng-Fu Xu

    2012-11-01

    Full Text Available Proteinase inhibitors play an important role in plant resistance of insects and pathogens. In this study, we characterized the serine proteinase inhibitor SaPIN2b, which is constitutively expressed in Solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor II (PIN2 family. The recombinant SaPIN2b (rSaPIN2b, which was expressed in Escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin A, chymotrypsin and trypsin. Moreover, rSaPIN2b also effectively inhibited the proteinase activities of midgut trypsin-like proteinases that were extracted from the devastating pest Helicoverpa armigera. Furthermore, the overexpression of SaPIN2b in transgenic tobacco plants resulted in enhanced resistance against H. armigera. Taken together, our results demonstrated that SaPIN2b is a potent serine proteinase inhibitor that may act as a protective protein in plant defense against insect attacks.

  14. Chemical forms of calcium in CA,Zn- and Ca,Cd-containing grains excreted by tobacco trichomes

    Energy Technology Data Exchange (ETDEWEB)

    Sarret, G.; Isaure, M.-P. [Environmental Geochemistry Group, LGIT, Univ. of Grenoble and CNRS, Grenoble cedex 9 (France)], E-mail: geraldine.sarret@ujf-grenoble.fr; Marcus, M.A. [Advanced Light Source (ALS), Lawrence Berkeley National Lab, Berkeley, California (United States); Harada, E. [Environmental Geochemistry Group, LGIT, Univ. of Grenoble and CNRS, Grenoble cedex 9 (France); Div. of Forest Resources, College of Forest Sciences, Kangwon National Univ., Chunchon, Kangwon-do (Korea, Republic of); Choi, Y.-E. [Div. of Forest Resources, College of Forest Sciences, Kangwon National Univ., Kangwon-do (Korea, Republic of); Pairis, S. [Inst. Neel CNRS-UJF, Dept. Matiere Condensee, Materiaux et Fonctions, Pole Instrumentation (Microscopie Electronique), Grenoble cedex 9 (France); Fakra, S. [Advanced Light Source (ALS), Lawrence Berkeley National Lab, Berkeley, California (United States); Manceau, A. [Environmental Geochemistry Group, LGIT, Univ. of Grenoble and CNRS, Grenoble cedex 9 (France)

    2007-10-15

    Tobacco (Nicotiana tabacum L. cv. Xanthi) plants exposed to toxic levels of zinc and cadmium excrete metals through their leaf trichomes (epidermal hairs) as Zn,Ca- and Cd,Ca-containing grains. Little is known about the nature and formation mechanism of these precipitates. The chemical, crystalline, and noncrystalline compositions of individual grains produced by tobacco were studied by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDX), micro-X-ray diffraction ({mu}XRD), and calcium K-edge micro X-ray absorption near edge structure ({mu}XANES) spectroscopy. Zinc is predominantly incorporated in calcite and cadmium in calcite and vaterite. Aragonite, which occurs occasionally, does not seem to contain trace metals. In addition to being precipitated in its three possible polymorphic forms, calcite, aragonite, and vaterite, calcium is also speciated as amorphous CaCO{sub 3} and possibly organic Ca in some grains. Most often, a particular grain consists of two or more crystalline and noncrystalline phases. The observed variability of intra- and inter-grain elemental and phase composition suggests that this biomineralization process is not constrained by biological factors but instead results from thermodynamically and kinetically controlled reactions. This study illustrates the potential of laterally resolved X-ray synchrotron radiation techniques ({mu}XRD and {mu}XANES) to study biomineralization and metal immobilization processes in plants. (author)

  15. Effect of heat shock on the chilling sensitivity of trichomes and petioles of African violet (Saintpaulia ionantha).

    Science.gov (United States)

    Saltveit, Mikal E.; Hepler, Peter K.

    2004-05-01

    Chilling at 6 degrees C caused an immediate cessation of protoplasmic streaming in trichomes from African violets (Saintpaulia ionantha), and a slower aggregation of chloroplasts in the cells. Streaming slowly recovered upon warming to 20 degrees C, reaching fairly stable rates after 4, 15, 25 and 35 min for tissue chilled for 2 min and for 2, 14 and 24 h, respectively. The rate of ion leakage from excised petioles into an isotonic 0.2 M mannitol solution increased after 12 h of chilling and reached a maximum after 3 days of chilling. A heat shock at 45 degrees C for 6 min reduced chilling-induced rates of ion leakage from excised 1-cm petiole segments by over 50%, namely to levels near that from non-chilled control tissue. Heat-shock treatments themselves had no effect on the rate of ion leakage from non-chilled petiole segments. Protoplasmic streaming was stopped by 1 min of heat shock at 45 degrees C, but slowly recovered to normal levels after about 30 min Chloroplasts aggregation was prevented by a 1 or 2 min 45 degrees C heat-shock treatment administered 1.5 h before chilling, but heat-shock treatments up to 6 min only slightly delayed the reduction in protoplasmic streaming caused by chilling. Tradescantia virginiana did not exhibit symptoms associated with chilling injury in sensitive species (i.e. cessation of protoplasmic streaming in stamen hairs and increased ion leakage from leaf tissue). PMID:15086815

  16. Trichomes as dangerous lollipops: do lizards also use caterpillar body and frass odor to optimize their foraging?

    Science.gov (United States)

    Stork, William F J; Weinhold, Alexander; Baldwin, Ian T

    2011-12-01

    When attacked by herbivores, plants produce toxic secondary metabolites that function as direct defenses, as well as indirect defenses that attract and reward predators of the offending herbivores. These indirect defenses include both nutritive rewards such as extra floral nectar, as well as informational rewards, such as the production and release of volatile compounds that betray the location of feeding herbivores to predators. Herbivory of Nicotiana attenuata by the tobacco hornworm (Manduca larvae) alters the volatile profiles of both the plant and larval headspace. Herbivory-elicited specific changes in the volatile profiles are detected by arthropod predators of Manduca larvae. The known predators that perceive volatile cues induced by Manduca herbivory of N. attenuata are insects that target Manduca at early developmental stages, when the larvae are still small; large, late-instar larvae may have outgrown these predation risks. However, here we offer evidence that branched chain aliphatic acids derived from the digestion of plant O-acyl sugars from trichomes may betray Manduca larvae to lizard predators during late developmental stages as well. PMID:22095147

  17. Chemical forms of calcium in CA,Zn- and Ca,Cd-containing grains excreted by tobacco trichomes

    International Nuclear Information System (INIS)

    Tobacco (Nicotiana tabacum L. cv. Xanthi) plants exposed to toxic levels of zinc and cadmium excrete metals through their leaf trichomes (epidermal hairs) as Zn,Ca- and Cd,Ca-containing grains. Little is known about the nature and formation mechanism of these precipitates. The chemical, crystalline, and noncrystalline compositions of individual grains produced by tobacco were studied by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDX), micro-X-ray diffraction (μXRD), and calcium K-edge micro X-ray absorption near edge structure (μXANES) spectroscopy. Zinc is predominantly incorporated in calcite and cadmium in calcite and vaterite. Aragonite, which occurs occasionally, does not seem to contain trace metals. In addition to being precipitated in its three possible polymorphic forms, calcite, aragonite, and vaterite, calcium is also speciated as amorphous CaCO3 and possibly organic Ca in some grains. Most often, a particular grain consists of two or more crystalline and noncrystalline phases. The observed variability of intra- and inter-grain elemental and phase composition suggests that this biomineralization process is not constrained by biological factors but instead results from thermodynamically and kinetically controlled reactions. This study illustrates the potential of laterally resolved X-ray synchrotron radiation techniques (μXRD and μXANES) to study biomineralization and metal immobilization processes in plants. (author)

  18. Contingent Capital with a Capital-Ratio Trigger

    OpenAIRE

    Paul Glasserman; Behzad Nouri

    2012-01-01

    Contingent capital in the form of debt that converts to equity when a bank faces financial distress has been proposed as a mechanism to enhance financial stability and avoid costly government rescues. Specific proposals vary in their choice of conversion trigger and conversion mechanism. We analyze the case of contingent capital with a capital-ratio trigger and partial and ongoing conversion. The capital ratio we use is based on accounting or book values to approximate the regulatory ratios t...

  19. Thin Capitalization Rules and Entrepreneurial Capital Structure Decisions

    OpenAIRE

    Alexandra Maßbaum; Caren Sureth

    2009-01-01

    Tax planners often choose debt over equity financing. As this has led to increased corporate debt financing, many countries have introduced thin capitalization rules to secure their tax revenues. In a general capital structure model we analyze if thin capitalization rules affect dividend and financing decisions, and whether they can partially explain why corporations receive both debt and equity capital. We model the Belgian, German and Italian rules as examples. We find that the so-called Mi...

  20. Thin Capitalization Rules and Multinational Firm Capital Structure

    NARCIS (Netherlands)

    Blouin, J.; Huizinga, H.P.; Laeven, L.; Nicodeme, G.

    2014-01-01

    Abstract: This paper examines the impact of thin capitalization rules that limit the tax deductibility of interest on the capital structure of the foreign affiliates of US multinationals. We construct a new data set on thin capitalization rules in 54 countries for the period 1982-2004. Using confide

  1. Human Capital and Optimal Positive Taxation of Capital Income

    NARCIS (Netherlands)

    B. Jacobs (Bas); A.L. Bovenberg (Lans)

    2005-01-01

    textabstractThis paper analyzes optimal linear taxes on capital and labor incomes in a life-cycle model of human capital investment, financial savings, and labor supply with heteroge- nous individuals. A dual income tax with a positive marginal tax rate on not only labor income but also capital inco

  2. NANNING China's Green Capital

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Nanning,the capital city of Guangxi province,is not only the political,economic and cultural center of the province,but also plays an important role in the economic development of southwest China.Nanning's advantageous location makes the city a commercial and communication center,opening China to Southeast Asia.

  3. Human Capital and Sustainability

    Directory of Open Access Journals (Sweden)

    Garry Jacobs

    2011-01-01

    Full Text Available A study of sustainability needs to consider the role of all forms of capital—natural, biological, social, technological, financial, cultural—and the complex ways in which they interact. All forms of capital derive their value, utility and application from human mental awareness, creativity and social innovation. This makes human capital, including social capital, the central determinant of resource productivity and sustainability. Humanity has entered the Anthropocene Epoch in which human changes have become the predominant factor in evolution. Humanity is itself evolving from animal physicality to social vitality to mental individuality. This transition has profound bearing on human productive capabilities, adaptability, creativity and values, the organization of economy, public policy, social awareness and life styles that determine sustainability. This article examines the linkages between population, economic development, employment, education, health, social equity, cultural values, energy intensity and sustainability in the context of evolving human consciousness. It concludes that development of human capital is the critical determinant of long-term sustainability and that efforts to accelerate the evolution of human consciousness and emergence of mentally self-conscious individuals will be the most effective approach for ensuring a sustainable future. Education is the primary lever. Human choice matters.

  4. Corruption and Social Capital

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    2003-01-01

    I examine the causal relation between social capiatl and corruption. A simple model illustrates potential mechanisms and yields testable implications, which I estimate in a sample of European countries. The estimated effect of social capital on corruption is found to be robust to the inclusion of a...... redistribution, which in turn reduces corruption....

  5. Microfoundations of Social Capital

    DEFF Research Database (Denmark)

    Thöni, Christian; Tyran, Jean-Robert; Wengström, Erik Roland

    We show that the standard trust question routinely used in social capital research is importantly related to cooperation behavior and we provide a microfoundation for this relation. We run a large-scale public goods experiment over the internet in Denmark and find that the trust question is a proxy...

  6. Is capitalism possible?

    NARCIS (Netherlands)

    Gaay Fortman, B. de

    1998-01-01

    In the two ages of its existence capitalism has given proof of its reformability. It was, however, anti-capitalist blueprints and ideas that constituted a continuous spiritual driving force towards reform. Today, after the collapse of real existing socialism there is an urgent need for new alternati

  7. Microfoundations of Social Capital

    DEFF Research Database (Denmark)

    Thöni, Christian; Tyran, Jean-Robert Karl; Wengström, Erik Roland

    2012-01-01

    Research on social capital routinely relies on survey measures of trust which can be collected in large and heterogeneous samples at low cost. We validate such survey measures in an incentivized public good experiment and show that they are importantly related to cooperation behavior in a large and...

  8. Towards Transnational Academic Capitalism

    Science.gov (United States)

    Kauppinen, Ilkka

    2012-01-01

    This paper contributes to current debates on the relationship between globalisation and higher education. The main argument of the paper is that we are currently witnessing transnationalisation of academic capitalism. This argument is illustrated by examining the collaboration between transnational corporations and research universities, and how…

  9. Revitalizing ecological capital

    NARCIS (Netherlands)

    Swagemakers, P.; Wiskerke, J.S.C.

    2011-01-01

    The modernization of agricultural food production has diminished and is diminishing the sustainable use of the local natural resource base, resulting in the fragmentation of landscapes and the decline of biodiversity. In this paper we analyze the revitalization of ecological capital, which provides

  10. Manage "Human Capital" Strategically

    Science.gov (United States)

    Odden, Allan

    2011-01-01

    To strategically manage human capital in education means restructuring the entire human resource system so that schools not only recruit and retain smart and capable individuals, but also manage them in ways that support the strategic directions of the organization. These management practices must be aligned with a district's education improvement…

  11. Venture Capital Backed Growth

    OpenAIRE

    Keuschnigg, Christian

    2002-01-01

    The paper proposes a simple equilibrium model of venture capital, entrepreneurship and innovation. Venture capitalists not only finance but also advise start-up entrepreneurs and thereby add value to new firms. The paper demonstrates how a productive and active VC industry boosts innovation driven growth.

  12. Auditing and bank capital regulation

    OpenAIRE

    Edward Simpson Prescott

    2004-01-01

    Auditing is introduced into a model of bank capital regulation. Deterministic and stochastic auditing strategies are studied. Contrary to intuition, auditing of bank risk should be focused on the safest banks because they hold the least amount of capital. Risky banks, which hold more capital, need to be audited less. The importance of auditing by regulators and penalties for non-compliance are discussed in light of the Basel II capital regulation proposals. Emphasis is placed on the importanc...

  13. Capitalism: A System of Conspiracy

    OpenAIRE

    Das, Subhendu

    2010-01-01

    There are some myths about American capitalism. Some of them are (1) Capitalism made America the richest nation, (2) Capitalism is based on self interest, and (3) America has democracy. We show that the survival of capitalism is based on several powerful conspiracy theories. We briefly describe these conspiracies. Our analysis is based on the following principles: (a) Laws of conservation, (b) System theoretic concepts, and (c) The global space time (GST) environment. Using these princip...

  14. Crony Capitalism: Caricature or Category?

    OpenAIRE

    Mazumdar, Surajit

    2008-01-01

    This paper, part of a series on Crony Capitalism and Contemporary India, examines the conceptual meaning of the term crony capitalism, which has acquired considerable popularity since it was used as an explanation for the East Asian crisis. The paper argues that the conception of crony capitalism as a description of a distinct kind of capitalism associated with the State playing a key role in the allocation process suffers from serious deficiencies and therefore does not provide a suitable fr...

  15. Entrepreneurship capital and economic performance

    OpenAIRE

    Audretsch, David B; Keilbach, Max

    2004-01-01

    The neoclassical model of the production function, as applied by Robert Solow to build the neoclassical model of growth, linked labor and capital to output. More recently, Romer and others have expanded the model to include measures of knowledge capital. In this paper we introduce a new factor, entrepreneurship capital, and link it to output in the context of a production function model. This paper explains what is meant by entrepre-neurship capital and why it should influence economic output...

  16. Technology Differences and Capital Flows

    OpenAIRE

    Sebastian Claro

    2004-01-01

    The one-to-one mapping between cross-country differences in capital returns and the direction of international capital flows is broken in a multisector world where international factor price differences are driven by technology differences. A technology-backward or low-return-to-capital country will face capital inflows or outflows after financial integration depending on whether non-tradable demand is bossted or not

  17. Market Timing and Capital Structure

    OpenAIRE

    Jeffrey A. Wurgler; Baker, Malcolm P.

    2001-01-01

    It is well known that firms tend to raise equity when their market values are high relative to book and past market values. We document that the resulting effects on capital structure are very persistent. As a consequence, current capital structure is strongly related to past market valuations. The results are difficult to explain within traditional theories of capital structure and suggest that capital structure is the cumulative outcome of past attempts to time the equity market.

  18. Risk, capital and financial crisis

    OpenAIRE

    Ghosh, Saibal

    2014-01-01

    Employing data on over 100 banks for Gulf Cooperation Council (GCC) countries during 1996-2011, we test the relation between risk and capital. The findings indicate that banks generally increase capital in response to an increase in risk, and not vice versa. Second, there is an uneven impact of regulatory pressure and market discipline on banks attitude towards risk and capital. Additionally, Islamic banks increased their capital as compared to conventional banks.

  19. Capital Taxation and Rent Seeking

    OpenAIRE

    Arefiev, Nikolay; Baron, Tatyana

    2006-01-01

    We find the optimal capital income tax rate in an imperfectly competitive economy, where some part of recourses is devoted to rent-seeking activity. Optimal tax offsets the difference between marginal social and marginal private return to capital, which is a result of rent seeking, and the difference between the before tax interest rate and the marginal productivity of capital, which arises from imperfect competition. Optimal capital income tax rate depends neither on other tax rates nor on o...

  20. Extended Measures of Capital Transactions

    OpenAIRE

    Jorge Selaive; Beatriz Velásquez; José Miguel Villena

    2008-01-01

    In this work, we extend de jure measures of capital account restrictions previously assembled by Miniane (2004) to a set of 181 economies for the period 1996-2005. Additionally, we propose two new measures of capital account restrictions. The first excludes prudential regulation and the second weights the indices by a proxy for the enforcement of capital restrictions. We analyze global tendencies and the process of capital account liberalization in Chile. For the group of economies, we observ...

  1. MODELLING SOCIAL CAPITAL AND GROWTH

    OpenAIRE

    Yuan K. Chou

    2002-01-01

    This paper proposes three theoretical growth models incorporating social capital, based on varied expositions on the concept of social capital and the empirical evidence gathered to date. In these models, social capital impacts growth by assisting in the accumulation of human capital, by affecting financial development through its effects on collective trust and social norms, and by facilitating networking between firms that result in the creation and diffusion of business and technological i...

  2. What Drives Venture Capital Fundraising?

    OpenAIRE

    Paul A. Gompers; Josh Lerner

    1999-01-01

    We examine the determinants of venture capital fundraising in the U.S. over the past twenty-five years. We study industry aggregate, state-level, and firm-specific fundraising to determine if macroeconomic, regulatory, or performance factors affect venture capital activity. We find that shifts in demand for venture capital appear to have a positive and important impact on commitments to new venture capital funds. Commitments by taxable and tax-exempt investors seem equally sensitive to change...

  3. Capital Mobility and Asset Pricing

    OpenAIRE

    Duffie, Darrell; Strulovici, Bruno

    2009-01-01

    We present a model for the equilibrium movement of capital between asset markets that are distinguished only by the levels of capital invested in each. Investment in that market with the greatest amount of capital earns the lowest risk premium. Intermediaries optimally trade off the costs of intermediation against fees that depend on the gain they can offer to investors for moving their capital to the market with the higher mean return. Those fees also depend on the bargaining power of the in...

  4. How venture capital works.

    Science.gov (United States)

    Zider, B

    1998-01-01

    The popular mythology surrounding the U.S. venture-capital industry derives from a previous era. Venture capitalists who nurtured the computer industry in its infancy were legendary both for their risk taking and for their hands-on operating experience. But today things are different, and separating the myths from the realities is crucial to understanding this important piece of the U.S. economy. Today's venture capitalists are more like conservative bankers than the risk takers of days past. They have carved out a specialized niche in the capital markets, filling a void that other institutions cannot serve. They are the linch-pins in an efficient system for meeting the needs of institutional investors looking for high returns, of entrepreneurs seeking funding, and of investment bankers looking for companies to sell. Venture capitalists must earn a consistently superior return on investments in inherently risky businesses. The myth is that they do so by investing in good ideas and good plans. In reality, they invest in good industries--that is, industries that are more competitively forgiving than the market as a whole. And they structure their deals in a way that minimizes their risk and maximizes their returns. Although many entrepreneurs expect venture capitalists to provide them with sage guidance as well as capital, that expectation is unrealistic. Given a typical portfolio of ten companies and a 2,000-hour work year, a venture capital partner spends on average less than two hours per week on any given company. In addition to analyzing the current venture-capital system, the author offers practical advice to entrepreneurs thinking about venture funding. PMID:10187243

  5. Intellectual Capital: Comparison and Contrast.

    Science.gov (United States)

    Madsen, Susan R.

    2001-01-01

    Suggests that one of the most important keys for improving individual and organizational performance is in developing and strengthening intellectual capital (IC) and explores the similarities and differences between the concepts of intellectual capital, human capital, and knowledge management. Presents four IC characteristics and addresses the…

  6. Working Paper on Social capital

    DEFF Research Database (Denmark)

    Lassen Hanan, Anne

    2013-01-01

    This paper outlines the major schools within social capital theory. Contemporary authors such as Coleman, Putnam and Bourdieu are elaborated on. The paper also presents a non-exhaustive review on studies of social capital. Furthermore, a criticial discussion on social capital is reviewed, before...

  7. Pension funds and capital accumulation

    OpenAIRE

    Belan, Pascal; Michel, Philippe; Wigniolle, Bertrand

    2001-01-01

    This note presents a model in which pension funds, by holding a signifiant share of capital assets, can exert a non competitive behavior on labor market. This leads to lower wages and higher capital returns, and can reduce capital accumulation and Long-run welfare.

  8. Thin Capitalization Rules and Entrepreneurial Capital Structure Decisions

    Directory of Open Access Journals (Sweden)

    Alexandra Maßbaum

    2009-12-01

    Full Text Available Tax planners often choose debt over equity financing. As this has led to increased corporate debt financing, many countries have introduced thin capitalization rules to secure their tax revenues. In a general capital structure model we analyze if thin capitalization rules affect dividend and financing decisions, and whether they can partially explain why corporations receive both debt and equity capital. We model the Belgian, German and Italian rules as examples. We find that the so-called Miller equilibrium and definite financing effects depend significantly on the underlying tax system. Further, our results are useful for the treasury to decide what thin capitalization type to implement.

  9. Comparative evaluation of average glandular dose and image of digital mammography and film mammography in Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. Mammography is the best method for breast-cancer screening and is capable of reducing mortality rates To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. Digital mammography has been proposed as a substitute for film mammography given the benefits inherent to digital technology. The purpose of our study was to compare the technical performance of digital mammographic and screen-film mammography. A PMMA phantom with objects to simulate breast structures. For the screen/film (SF) technique the results showed that 54% mammography units did not achieve the minimum acceptable performance as far the image quality. Besides, 67% services showed inadequate performance in their processing systems, which had significant influence on the image quality. At the mean glandular dose only 44% of digital systems evaluated were compliant in all thicknesses of PMMA. The average glandular dose AGD was 90 % higher than in screen/film systems. (authors)

  10. Sôbre o órgão abdominal glandular de Arilus carinatus (Forster, 1771: (Heteroptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    Rudolf Barth

    1961-04-01

    Full Text Available Descreve-se um órgão glandular, encontrado na fêmea de Arilus carinatus, de um tipo ainda desocnhecido em insetos. Localiza-se, em forma de um saco membranoso, nos dois lados da linha ventral, entre os 8º e 9º segmentos abdominais. O órgão é expulso por um aumento da pressão interna da cavidade abdominal e volta ao estado de repouso, no interior do corpo, por meio de contração muscular. A vesícula retal volumosa forma, em direção distal, um amplo divertículo, do qual partem dois "tubos retais" que penetram nas vesículas membranosas, tendo na superfície destas uma abertura em forma de fenda. A hipoderme do divertículo, bem como a de uma região da vesícula retal e da parte basal dos tubos retais é glandular. A secreção possui um cheiro intenso e ardido que lembra o gás de acetileno. Trata-se, provàvelmente, de uma glândula repugnatória. Não se sabe nada sôbra a ocorrência do aparelho no macho e em outras espécies de Reduviídeos.

  11. Evidence for estrogen-dependent uterine serpin (SERPINA14) expression during estrus in the bovine endometrial glandular epithelium and lumen.

    Science.gov (United States)

    Ulbrich, Susanne E; Frohlich, Thomas; Schulke, Katy; Englberger, Eva; Waldschmitt, Nadine; Arnold, Georg J; Reichenbach, Horst-Dieter; Reichenbach, Myriam; Wolf, Eckhard; Meyer, Heinrich H D; Bauersachs, Stefan

    2009-10-01

    Uterine secretions have a dominant impact on the environment in which embryo development takes place. The uterine serpins (SERPINA14, previously known as UTMP) are found most abundantly during pregnancy in the uterus of ruminants. Although progesterone is currently assumed to be the major regulator of SERPINA14 expression, our recent study of transcriptome changes in bovine endometrium during the estrous cycle unexpectedly detected a marked upregulation of SERPINA14 mRNA levels at estrus. The present study describes the full-length mRNA sequence, genomic organization, and putative promoter elements of the SERPINA14 gene. The SERPINA14 mRNA abundance was quantified by real-time RT-PCR in intercaruncular endometrium at several time points during the estrous cycle and early pregnancy. Highest levels were found at estrus, followed by a dramatic decrease and a moderate expression during the luteal phase. Transcript levels were higher in pregnant endometrium compared with controls at Day 18. At estrus, immunoreactive protein was localized in deep glandular epithelium, and Western blotting concomitantly showed the 52-kDa form in uterine flushings. SERPINA14 mRNA was significantly upregulated in glandular endometrial cells in vitro after stimulation with estradiol-17beta and progesterone, but not after interferon-tau treatment. Our results clearly demonstrate that SERPINA14 appears distinctly in bovine endometrium during the estrus phase. A supporting role toward providing a well-prepared endometrial environment for passing gametes, especially sperm, is assumed. PMID:19494250

  12. Salivary gland acinar cells regenerate functional glandular structures in modified hydrogels

    Science.gov (United States)

    Pradhan, Swati

    Xerostomia, a condition resulting from irradiation of the head and neck, affects over 40,000 cancer patients each year in the United States. Direct radiation damage of the acinar cells that secrete fluid and protein results in salivary gland hypofunction. Present medical management for xerostomia for patients treated for upper respiratory cancer is largely ineffective. Patients who have survived their terminal diagnosis are often left with a diminished quality of life and are unable to enjoy the simple pleasures of eating and drinking. This project aims to ultimately reduce human suffering by developing a functional implantable artificial salivary gland. The goal was to create an extracellular matrix (ECM) modified hyaluronic acid (HA) based hydrogel culture system that allows for the growth and differentiation of salivary acinar cells into functional acini-like structures capable of secreting large amounts of protein and fluid unidirectionally and to ultimately engineer a functional artificial salivary gland that can be implanted into an animal model. A tissue collection protocol was established and salivary gland tissue was obtained from patients undergoing head and neck surgery. The tissue specimen was assessed by histology and immunohistochemistry to establish the phenotype of normal salivary gland cells including the native basement membranes. Hematoxylin and eosin staining confirmed normal glandular tissue structures including intercalated ducts, striated ducts and acini. alpha-Amylase and periodic acid schiff stain, used for structures with a high proportion of carbohydrate macromolecules, preferentially stained acinar cells in the tissue. Intercalated and striated duct structures were identified using cytokeratins 19 and 7 staining. Myoepithelial cells positive for cytokeratin 14 were found wrapped around the serous and mucous acini. Tight junction components including ZO-1 and E-cadherin were present between both ductal and acinar cells. Ductal and acinar

  13. Selection of intellectual capital management strategies

    OpenAIRE

    Shcherbachenko Viktoriia Oleksiivna

    2016-01-01

    This article deals with the selection of intellectual capital management strategy. The attention is paid to the structure of intellectual capital, which consists of human capital, customer capital, process capital, intellectual property, intangible assets. The algorithm of selection of intellectual capital management strategy was created by author.

  14. Social Capital in Rural Denmark

    OpenAIRE

    Svendsen, G.L.; Svendsen, Gert Tinggaard

    1999-01-01

    What are the roots of social capital and how can it be measured and built? Social capital is considered as a new production factor which must be added to the conventional concepts of human and physical capital. Social capital is productive because it increases the level of trust in a society and allows more transactions to take place without third-party enforcement. Theory and lessons from empirical evidence lead to the general recommendation that any loss in social capital must be deducted f...

  15. Performance systems and social capital

    DEFF Research Database (Denmark)

    Rasmussen, Grane Mikael Gregaard; Edwards, Kasper

    2014-01-01

    Performance systems and social capital are considered mutually exclusive. Contemporary studies show that social capital is essential in generating performance improvement. This raises an important question: “How do performance systems and social capital correspond?” This study draws on findings...... from a study on implementation of a performance system in Danish construction. The results show causalities between implementing the performance system and the emergence of social capital in construction projects. Results indicate that performance systems and social capital is not mutually exclusive...

  16. Social Capital in Rural Denmark

    DEFF Research Database (Denmark)

    Svendsen, G.L.; Svendsen, Gert Tinggaard

    1999-01-01

    What are the roots of social capital and how can it be measured and built? Social capital is considered as a new production factor which must be added to the conventional concepts of human and physical capital. Social capital is productive because it increases the level of trust in a society and ......-sized groups in the Danish Cooperative Dairy Movement was eliminated due to economies of scale. It may be so that an alternative way of production, taking social capital into account, could have increased economic growth further....

  17. Ensayo sobre el Capital Social

    Directory of Open Access Journals (Sweden)

    Ramón Frediani

    2011-08-01

    Full Text Available En la teoría económica existen distintas definiciones de capital: capital físico, el capital en recursos naturales, el capital financiero, el capital en infraestructura económica, el capital en infraestructura social y el capital humano. Todos ellos son condiciones necesarias para que un país alcance el desarrollo económico y social y un alto estándar y calidad de vida de sus habitantes, pero no suficientes puesto que hace falta una categoría adicional de capital. En los últimos años ha surgido el análisis de una nueva categoría: el Capital Social. El concepto se ha convertido en uno de los temas más debatidos de las ciencias sociales y políticas. Se refiere a un elemento invisible, etéreo, menos tangible que el capital humano (conocimientos y/o habilidades de los individuos o el capital físico (bienes materiales, pero que resulta decisivo para la actividad productiva, la satisfacción de las necesidades personales y el desarrollo comunitario y de una sociedad toda.

  18. Capital theory and rational choice

    Directory of Open Access Journals (Sweden)

    Golubović Nataša

    2009-01-01

    Full Text Available Almost from the very beginning of economic science the notion of capital has been the subject of numerous controversies. The main reason for the concept's controversial nature is that it explains interest and profit. In Marxian theory, where 'manner of production' determines forms of activities, mutual relationships and life of individuals, capital appears as a social phenomenon i.e. social relation. Goods and money are not capital by themselves but become capital in the capitalist way of production. Economics mainstream is based on methodological individualism upon which explanation of social phenomena and processes must be derived from individual behavior and motivation. Capital, therefore, is not a product of capitalism as a socially and historically specific form of economic organization, but is rather perceived as connected to the individual and his or her rational behavior. Rational choice is the basic and sometimes the only explanatory factor in the neoclassic theories of capital. Although theories of human and cultural capital point out the interdependence between individual activity and choice on the one hand, and social position on the other hand in the process of capitalization, the connection remains in the background and somehow unclear. A more explicit indication of the interdependence between social structure and choice can be found in the theory of social capital. The goal of this paper is to explore the role of rational choice theory in explaining the nature of capital.

  19. Capital Requirements and Banks' Leniency

    DEFF Research Database (Denmark)

    Dietrich, J. Kimball; Wihlborg, Clas

    2003-01-01

    We investigate the effect of changes in capital regulation on the strictness(leniency) of loan terms using a simple model of bank capital requirements andasset quality examinations. Banks offer different levels of `leniency' in the senseof willingness to offer automatic extensions of loans in the...... presence of temporarypayment difficulties of borrowers. Banks offering lenient (less strict) loan termsmust have higher initial levels of capital and charge higher loan rates. Whencapital requirements are increased, both strict and lenient banks hold higher levelsof initial capital and they raise loan...... rates. As capital requirements increase thedifference between initial capital levels and between interest rates of strict andlenient banks decrease. Thus, higher capital requirements in recessions tend toreduce the interest rate premium paid for leniency. If a recession is interpreted asan increase in...

  20. Colonization of tomato plants by Salmonella enterica is cultivar dependent, and type 1 trichomes are preferred colonization sites.

    Science.gov (United States)

    Barak, Jeri D; Kramer, Lara C; Hao, Ling-yun

    2011-01-01

    Nontyphoid salmonellosis caused by Salmonella enterica is the most common bacterial food-borne illness in humans, and fresh produce, including tomatoes, is a common vehicle. Accumulating data indicate that human enteric pathogenic bacteria, including S. enterica, interact actively with plants. Tomato plants were inoculated with S. enterica to evaluate plausible contamination routes and to determine if the tomato cultivar affects S. enterica colonization. S. enterica population levels on tomato leaves were cultivar dependent. S. enterica levels on Solanum pimpinellifolium (West Virginia 700 [WVa700]) were lower than on S. lycopersicum cultivars. S. enterica preferentially colonized type 1 trichomes and rarely interacted with stomata, unlike what has been reported for cut lettuce leaves. Early S. enterica leaf colonization led to contamination of all fruit, with levels as high as 10(5) CFU per fruit. Reduced bacterial speck lesion formation correlated with reduced S. enterica populations in the phyllosphere. Tomato pedicels and calyxes also harbored large S. enterica populations following inoculation via contaminated water postharvest. WVa700 green fruit harbored significantly smaller S. enterica populations than did red fruit or S. lycopersicum fruit. We found that plants irrigated with contaminated water had larger S. enterica populations than plants grown from seeds planted in infested soil. However, both routes of contamination resulted in detectable S. enterica populations in the phyllosphere. Phyllosphere S. enterica populations pose a risk of fruit contamination and subsequent human disease. Restricting S. enterica phyllosphere populations may result in reduced fruit contamination. We have identified WVa700 as a tomato cultivar that can restrict S. enterica survival in the phyllosphere. PMID:21075871

  1. Contabilidad del capital intelectual

    OpenAIRE

    Myriam Ruiz Tibaná; Ramon Elias Jimenez Arias; Tito Duarte

    2007-01-01

    El capital intelectual es un valor intangible que debe incorporarse a los estados financieros, como parte de la generación de valor de todos los trabajadores de una organización. Existen algunos modelos que permiten cuantificarlo, aunque es preciso reconocer que debemos ahondar con más precisión con el objeto de contar con un mayor número de adeptos a esta importante referencia.

  2. Capital cost estimate

    Science.gov (United States)

    1975-01-01

    The capital cost estimate for the nuclear process heat source (NPHS) plant was made by: (1) using costs from the current commercial HTGR for electricity production as a base for items that are essentially the same and (2) development of new estimates for modified or new equipment that is specifically for the process heat application. Results are given in tabular form and cover the total investment required for each process temperature studied.

  3. Social capital and education

    OpenAIRE

    Timur Natkhov

    2012-01-01

    Timur Natkhov, Ph.D. in Economics, Associate Professor in the Subdepartment of Institutional Economics, National Research University - Higher School of Economics, Moscow, Russian Federation. Email: The paper presents a brief evolution of studies on the relationship between education and social capital in different countries. A distinctive feature of these studies is their interdisciplinary nature, as they combine theories and methods of different social sciences.To ide...

  4. Entrepreneurial Human Capital

    OpenAIRE

    Iversen, Jens; Malchow-Møller, Nikolaj; Sørensen, Anders

    2009-01-01

    We argue that formal schooling and wage-work experience are complementary types of human capital for entrepreneurs. Strong empirical support is found for this hypothesis as the interaction term between schooling and actual wage-work experience enters positively and significantly in a Mincer equation, whereas the effect of schooling in the absence of wage-work experience is insignificant. These results are extremely robust towards more flexible specifications, including fixed-effects estimatio...

  5. Managers and Market Capitalism

    OpenAIRE

    Rebecca Henderson; Karthik Ramanna

    2013-01-01

    In a capitalist system based on free markets, do managers have responsibilities to the system itself? If they do, should these responsibilities shape their behavior when they are engaging in the political process in an attempt to structure the institutions of capitalism? The prevailing view-perhaps most eloquently argued by Milton Friedman-is that the first duty of managers is to maximize shareholder value, and thus that they should take every opportunity (within the bounds of the law) to str...

  6. Investments in human capital

    OpenAIRE

    Milost, Franko; Novak, Matic

    2016-01-01

    Investments in human capital (employees) include investments in the direct assurance of working abilities, investments in health and well-being and investments in loyalty to the company. These investments are crucial for the long-term existence and development of a company, but their value is not disclosed on the assets side of the classical balance sheet. The most important argument given by the proponents of this approach is that the economic benefits stemming from such investments are unce...

  7. Outside Entrepreneurial Capital

    OpenAIRE

    Andy Cosh; Douglas Cumming; Alan Hughes

    2005-01-01

    This paper investigates the internal versus external financing decisions among 1900 early stage privately held UK firms in 1996-1997. We study the factors that affect rejection rates in applications for outside finance among the different types of investors, taking into account the non-randomness in a firm’s decision to seek outside finance. The data support the traditional pecking order theory; firms with greater capital expenditures / profits are more likely to seek finance and apply for mo...

  8. 与黄瓜有毛基因紧密连锁的 SSR 标记%SSR Marker Linked to Cucumber Trichomes Characteristic Related Gene

    Institute of Scientific and Technical Information of China (English)

    王惠哲; 李淑菊; 杨瑞环; 管炜

    2013-01-01

    以有毛亲本F80为母本,无毛突变体F80WM为父本杂交,配制F1、F2、BC1群体,通过对6世代群体有无刚毛特征的观察和统计分析,研究有刚毛性状的遗传规律,并利用BSA法、SSR技术筛选与刚毛性状基因紧密连锁的分子标记。结果表明,黄瓜无毛性状是由1对核基因控制的稳定遗传的隐性性状,有刚毛相对于无毛为完全显性。通过BSA法和SSR分子标记,应用1193对引物组合对无毛、有毛亲本进行筛选,筛选到了1个与黄瓜有毛性状相关的显性标记SSR01647。测序结果表明,片段长度为164 bp,在有毛个体中扩增出了164 bp的特异片段,具有13个TC重复序列,无毛个体中未扩增出条带。经组外其他F2单株验证发现鉴定结果符合率高达100%。该性状可以作为苗期遗传标记性状,在杂交育种和品种纯度鉴定上有极大的利用价值。%The glabrous mutant F80WM was found in the inbred line F80 and can be inherited stably .F2 and BC1 population derived from F1 of F80(trichomes female)and F80WM(glabrous male)was used as materials to study the inheritance and molecular marker associated to the trichomes and glabrous trait .The results indicated that the glabrous trait was controlled by a pair of recessive gene ,and the character of trichomes was dominant to that of glabrous .The polymorphism between trichomes and glabrous parents of cucumber were studied using BSA method and SSR technology.1 193 SSR markers were screened,and a dominant marker SSR01647 was obtained.Sequen-cing of the fragment indicated that the lengths were 164 bp.The trichomes F2 plants possessed the 164 bp frag-ments,and the glabrous F2plants were no fragments.The marker was closely linked to the cucumber trichomes trait-related gene ,and the marker was confirmed to be 100%accurate by F 2 individuals .The trait was a useful marker for hybridization and purity identification of F 1 hybrids .

  9. Comportamento da dose glandular versus contraste do objeto em mamografia: determinação de formalismo semi-empírico para diferentes combinações alvo-filtro Behavior of subject contrast versus glandular dose in mammography: determination of a semi-empirical formalism for different target-filter combinations

    Directory of Open Access Journals (Sweden)

    Gabriela Hoff

    2006-06-01

    Full Text Available OBJETIVO: Verificar o efeito da mudança no contraste do objeto, tempo de exposição e dose de radiação quando diferentes espessuras de filtração de molibdênio (Mo e ródio (Rh são empregadas em mamógrafos. MATERIAIS E MÉTODOS: Realizaram-se medidas da exposição na entrada da pele com uma câmara de ionização para diferentes espessuras para os filtros de Mo e Rh. Para determinar a dose glandular média foi utilizado simulador de BR12 (50% tecido adiposo e 50% tecido glandular de diferentes espessuras (4 cm e 8 cm. Energias na faixa de 24 kVp a 34 kVp foram empregadas e filmes Kodak MinR 2000 foram utilizados. RESULTADOS: Os resultados evidenciaram dados de contraste do objeto, dose glandular e tempo de exposição para diferentes espessuras de filtros adicionais e diferentes tensões. Esses dados indicaram aumento nos valores de contraste do objeto e tempo de exposição, com o aumento da espessura dos filtros. A dose glandular apresentou comportamento com diferentes tendências para cada caso analisado. Equações foram definidas para possibilitar a estimativa do contraste do objeto, dose glandular e tempo de exposição para os casos estudados. CONCLUSÃO: Os resultados possibilitaram a estimativa de equações que auxiliam na verificação do comportamento do contraste do objeto e da dose glandular para simuladores com espessura de 4 cm e 8 cm e para os filtros de Rh e Mo. Dessa forma, torna-se possível estimar a figura de mérito (razão entre o contraste do objeto e a dose glandular, podendo auxiliar na análise da relação risco-benefício dos casos estudados.OBJECTIVE: Our purpose was to verify the effect of changes in subject contrast, exposure time and radiation dose when different thicknesses of molybdenum (Mo and rhodium (Rh filters are used in mammography equipments. MATERIALS AND METHODS: Entrance skin exposure measurements were performed with an ionization chamber for different thicknesses of Mo and Rh filters

  10. Células glandulares atípicas e câncer de colo uterino: revisão sistemática Atypical glandular cells and cervical cancer: systematic review

    OpenAIRE

    Juliana Pedrosa de Holanda Marques; Lívia Bandeira Costa; Ana Paula de Souza e Pinto; Anacássia Fonseca de Lima; Maria Eugênia Leite Duarte; Ana Paula Fernandes Barbosa; Paloma Lys de Medeiros

    2011-01-01

    Atipias de células glandulares em esfregaços cervicovaginais é um achado citológico na rotina de rastreamento do câncer cervical, que aumentou nas últimas décadas. Sua constatação é importante clinicamente, pois é alta a percentagem de casos associados com doença cervical e endometrial de alto grau e câncer. Este trabalho avaliou, por meio de uma revisão sistemática, estudos que investigaram o perfil das lesões de colo uterino em avaliações histológicas de seguimento de pacientes já diagnosti...

  11. False positive reaction due to endogenous biotin activity in glandular epithelium of decidua Reação falso positiva em epitélio glandular da decídua devido a atividade endógena de biotina

    Directory of Open Access Journals (Sweden)

    Liliana Cruz Spano

    2005-06-01

    Full Text Available Biotin-labeled probe was used in an in situ hybridisation assay to localize virus infection in formalin-fixed, paraffin embedded tissues taken from eleven abortion cases. Probes for human cytomegalovirus (HCMV, human Parvovirus B19 (B19 and human adenovirus type 2 (HAd2, were labeled with biotin-11-dUTP by nick-translation reaction. Streptavidin-alkaline-phosphatase (SAP was used to detect biotin, followed by 4-nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP solution. Positive reaction was observed in nucleus of glandular ephitelium cells of decidua either in positive or in negative control at first and second gestational trimester. The reaction was not inhibited with blocking solution for alkaline phosphatase endogenous activity and it persisted even with probes omission. The use of adequate negative control permitted to reveal the presence of nuclear biotin in glandular epithelium of decidua, responsible for false positivity in detection systems involving streptavidin biotin system (StrepABC. The stained cells resembled to cytophatic effect due to herpesvirus, which could induce further misinterpretation. The results obtained in this study strongly recommend that DNA detection by in situ hybridisation reaction in gestational endometrium should be done without using StrepABC system.Sondas marcadas com biotina foram utilizadas neste trabalho para detecção de infecção viral por hibridização in situ em tecidos fixados com formalina e embebidos em parafina de 11 casos obtidos de abortamento. Sondas para citomegalovírus humano (HCMV, parvovírus B19 humano (B19 e adenovírus humano tipo 2 (HAd2, foram marcadas com biotina-11-dUTP através da reação de nick-translation. Estreptavidina conjugada com fosfatase alcalina (SAP seguida por solução de 4-nitro-azul de tetrazolio/5-bromo-4-cloro-3-indolil fosfato (NBT/BCIP foram utilizadas para detecção da biotina após a reação de hibridização. Reação positiva foi

  12. fuente de capital humano

    Directory of Open Access Journals (Sweden)

    Ligia Becerra

    2005-01-01

    Full Text Available El capital intelectual es una concepción novedosa, tipificada como un activo intangible que agrega valor a la empresa; está formado por tres componentes: el capital organizacional, el humano y el relacional. El capital humano está relacionado con el desarrollo y los conocimientos del individuo, que permite diferenciar a un profesional de otro. El objetivo de este trabajo es analizar la formación del Contador Público egresado de la Universidad de Los Andes (ULA de Trujillo, como fuente de capital humano para su desempeño profesional. Los datos se recolectaron aplicando un cuestionario a una muestra aleatoria de 47 de estos profesionales, empleando para el análisis y presentación de los resultados técnicas estadísticas. La investigación evidencia que la mayoría de los encuestados poseen un nivel de satisfacción de medio a bajo con su formación de pregrado, señalando como principales debilidades del Plan de Estudio las áreas tributaria y cambiaria, el manejo instrumental del inglés y el conocimiento de las normativas que rigen el sistema económico. La formación en algunas de estas áreas la han mejorado a través de otras actividades de capacitación. No obstante reconocen algunas fortalezas tales como: el aprendizaje y dominio de conceptos y Principios Contables de Aceptación General, las matemáticas y estadística, el manejo de la contabilidad computarizada y las habilidades para analizar e interpretar problemas contables. Se concluye que a pesar de las deficiencias, la realización de cursos de actualización, junto con las fortalezas en la formación de la carrera, ha contribuido a que el contador público egresado de la ULA de Trujillo constituya un capital humano con ventaja competitiva.

  13. Venture Capital, Private Firms, and the Capital Acquisition Process

    OpenAIRE

    Mull, Rick H.

    1994-01-01

    This paper presents an empirical examination of the incentives motivating venture capitalists and sample of growth option intensive private firms with acute capital requirements to interact, the gains each group achieves through this association, the types of private firms successfully attracting venture capital, and mechanisms used in this funding process. Results show that venture capital backed firms achieve growth rates (1) greater than expected, and (2) greater than a matched sample of n...

  14. Capital Gains Taxes, Irreversible Investment, and Capital Structure

    OpenAIRE

    Norman Schuerhoff

    2004-01-01

    Personal taxation can be an important determinant of corporate investment and financing decisions if the marginal investor is taxed. I develop a dynamic capital budgeting model under realization-based capital gains taxation that highlights distinct cross-sectional and time-series implications. Capital gains taxation creates an embedded tax timing option that reduces investors’ uncertainty about after-tax payoffs in downstates. The inherent asymmetry in personal taxation diminishes the value...

  15. Capital Income Taxation and Tax Criteria in International Capital Markets

    OpenAIRE

    Hannu Piekkola

    1995-01-01

    The study analyses the capital income taxation of foreign-source income, where residence and source criteria are the two well-known tax criteria. The study presents a globally optimal tax rule which equalizes the shadow price of capital in the countries and which is assumed to be a weighted average of the return on savings and on investment, i.e. depending on the gross rate of return to the extent that capital contributes to the capital used, and on the net interest rate to the extent that ca...

  16. An audit of cervicovaginal cytology in a teaching hospital: Are atypical glandular cells under-recognised on cytological screening?

    Directory of Open Access Journals (Sweden)

    Crasta Julian

    2009-01-01

    Full Text Available Background: Cervical cytology screening for carcinoma of the cervix in India is mainly opportunistic in nature and is practiced mainly in urban centres. The effectiveness of cervical cytology screening depends on various factors. The quality of cervicovaginal cytology service is assessed by various quality indices and by cyto-histology correlation, which is the most important quality assurance measure. Aims: To describe the cervical cytology diagnoses, estimate the quality indices, and evaluate the discrepant cases on cytohistological correlation. Settings and Design: Retrospective observational study from a tertiary care centre in South India. Materials and Methods: Using a database search, all the cervicovaginal cytology reported during the period of 2002-2006 was retrieved and various diagnoses were described. The data was analysed to assess the quality indices. The cytohistologically discrepant cases were reviewed. Results: A total of 10,787 cases were retrieved, of which 98.14% were labeled negative and 1.36% were unsatisfactory for evaluation. A few (0.81% of the cases were labeled as squamous intraepithelial lesions and 0.38% as atypical squamous cells. The ASCUS: SIL ratio was 0.5. Cytohistological correlation revealed a total of ten cases with significant discrepancy. The majority of these were carcinomas that were misdiagnosed as atypical glandular cells. These cytology smears and the subsequent biopsies were reviewed to elucidate the reasons for the discrepancies. Conclusions: The cervical cytology service at our centre is well within the accepted standards. An increased awareness of cytological features, especially of glandular lesions, a good clinician-laboratory communication and a regular cytohistological review would further improve the diagnostic standards.

  17. Digital breast tomosynthesis and digital mammography: A comparison of figures of merit for various average glandular doses

    Science.gov (United States)

    Kim, Ye-seul; Park, Hye-Suk; Park, SuJin; Kim, Hee-Joung; Choi, Jae-Gu; Choi, Young-Wook; Park, Jun-Ho; Lee, Jae-Jun

    2013-05-01

    Previous studies on the application of tomosynthesis to breast imaging have demonstrated the potential of digital breast tomosynthesis (DBT). DBT can improve the specificity of digital mammography (DM) through improved marginal visibility of lesions and early breast cancer detection for women with dense breasts. To investigate possible improvements in the accuracy of lesion detection with DBT systems as compared to DM, we conducted a quantitative evaluation by using simulated lesions embedded in a breast phantom. A prototype DBT and dedicated DM system were used in this study. For the DBT system, the average glandular dose (AGD) was calculated using a formalism that was a simple extension of mammography dosimetry. The DBT and the DM images were acquired with average glandular doses (AGDs) ranging from 1 to 4 mGy. To analyze the results objectively, we calculated metrics for in-plane lesion visibility in the form of the contrast-to-noise ratio for the in-focus plane from the DBT reconstruction image and from the craniocaudal (CC) image from the DM system. The imaging performance of DBT was quantitatively compared with that of DM in terms of the figure of merit. Although the DM showed better results in terms of the contrast-to-noise ratio (CNR) of the mass due to the reduced overlapping of tissue and lesion, an increase in breast thickness of over 3 cm increased the CNR of the mass with the DBT system. For microcalcification detection, the DBT system showed significantly higher CNR than the DM system and gave better predictions of the microcalcification size. We compared the performances of the DM and the DBT systems for various AGDs and breast thicknesses. In conclusion, the results indicate that the DBT systems can play an important role in the detection of masses or microcalcifications without severe compression.

  18. Capital social et anthroponomie

    OpenAIRE

    Peaucelle, Irina

    2002-01-01

    Dans ce texte j'analyse les relations entre la composante Santé du capital social et la reproduction élargie de l'économie. Il s'agit aussi de discuter des méthodes d'évaluation de santé des populations pour apprécier leur potentiel de travail. En s'appuyant sur des travaux en psychologie sociale, je cherche à appréhender les rythmes anthroponomiques de l'évolution économique.

  19. Knight Capital Americas LLC

    DEFF Research Database (Denmark)

    Austin, Robert D.; Meister, Darren

    2015-01-01

    It took 19 years to build Knight Capital Americas LLC into the largest market maker on the New York Stock Exchange, but on August 1, 2012, it took only 45 minutes for the firm to be wiped out by an information technology (IT) problem: a change in the company's software caused it to lose more than...... officer, other managers and the board of directors have done differently? What lessons does this story hold for how firms should be managed and governed? And what does it say about our ability to manage risk in large modern corporations operating in increasingly fast-moving and complex global markets?...

  20. Capital social comunicativo

    Directory of Open Access Journals (Sweden)

    Darío Ángel

    2011-01-01

    Full Text Available En este artículo se buscan establecer las bases para una transformación del tradicional triángulo comunicativo emisor-mensaje-receptor, por un esquema que haga alusión a la dinámica social de la comunicación relacionada con lo público: actores-escenarios-sentidos. De esta forma, es posible conformar guías para la acción y encontrar en los actores ciudadanos de comunicación, la conformaciónde un capital social para la democracia.

  1. The Genesis of Capitalism

    DEFF Research Database (Denmark)

    Li, Xing

    2004-01-01

    foremost a transformative process involving political repercussions as being dealt with here (enforced variation, reshaping, selection and distortion). In sum, the paper intends to problematize the significance of the evolutionary explanation, the culturalist approach as well as the economistic...... (historical, divine, spiritual, miraculous), the establishment of capitalism is less the result of a force for cultural and economic dynamism than the realization of a political project. In other words, from being an enterprise within defined geographical boundaries to becoming a global project is first and...

  2. Contratos de capital humano

    Directory of Open Access Journals (Sweden)

    Oscar Alejandro Goyes Viteri

    2005-01-01

    Full Text Available Este documento busca dar a conocer el tema de la inversión en capital humano a través de la celebración de contratos atípicos y utilizando la fiducia mercantil y la titularización como vehículos financieros. Por medio de estos contratos un estudiante obtiene los recursos que requiere para financiar su educación superior, a cambio de entregar un porcentaje de sus ingresos después de su graduación a quien financió la operación.

  3. Contratos de capital humano

    OpenAIRE

    Oscar Alejandro Goyes Viteri

    2005-01-01

    Este documento busca dar a conocer el tema de la inversión en capital humano a través de la celebración de contratos atípicos y utilizando la fiducia mercantil y la titularización como vehículos financieros. Por medio de estos contratos un estudiante obtiene los recursos que requiere para financiar su educación superior, a cambio de entregar un porcentaje de sus ingresos después de su graduación a quien financió la operación.

  4. Developing Moral Capital in Schools

    OpenAIRE

    Çelik, Vehbi; Mevlana Üniversitesi, Eğitim Fakültesi, Eğitim Bilimleri Bölümü

    2014-01-01

    An abundance of models and approaches have been formed to develop school effectiveness. Schools have been analyzed with respect to psychological, sociological, cultural and administrative dimensions. Social and cultural capitals- as the recently developed nonmonetary forms of capital-have been investigated with respect to school organizations. Nonetheless so far there has been no in-depth research on moral capital in schools as an original concept. In the present research, the concept of mora...

  5. Worker Remittances and Capital Flows

    OpenAIRE

    Buch, Claudia M; Kuckulenz, Anja; Le Manchec, Marie-Helene

    2002-01-01

    The debate on the risks and benefits of the globalisation of international capital markets has focused on the volume and the volatility of the main capital flows — foreign direct investment (FDI), portfolio investment, and foreign bank lending. Financial transfers in the form of worker remittances have received less attention in this context. This paper provides an analysis on the magnitude of remittances, their volatility, and their relationship to other capital flows. Moreover, we provide ...

  6. Re-Thinking Social Capital

    Directory of Open Access Journals (Sweden)

    Zlatko Bukač

    2011-06-01

    Full Text Available The concept of social capital has been used very often in sociological researches over the last two decades. Measuring social capital in civil society, neighborhoods and educational systems is merely a part of its popular usage. Many sociologists tend to use the concept of social capital very freely and therefore expand the definition of social capital. The author’s personal experience indicates that there have been a great number of academic discussions, research planning and public speeches implementing the notion of social capital without taking a detailed consideration of what that concept truly entails. By overviewing the available literature on social capital, it is actually no wonder that both sociologists and the noted concept were in this confusing situation. As Field stated in his book Social Capital (Key Ideas, published in 2008, his work was “the first attempt to provide an extended introduction on increasingly influential concept of social capital” (Field 1. Quibria notes that even though there is a vast number of research conducted on social capital in many academic fields and with various approaches ‘the concept of social capital remains largely elusive’’(1. That obviously is not an obstacle because there is a constantly growing interest in social capital. A vast body of research concerning, measuring, and defining social capital is available today, which helps a researcher to analyze and compare all of the perspectives concerning social capital. This can be of great importance when researchers approach a somewhat new subject of research such as online communication and, more specifically, online games.

  7. Crises and human capital accumulation

    OpenAIRE

    Freddy Heylen; Lorenzo Pozzi

    2007-01-01

    This paper studies the effects of crises on human capital formation. Theoretically, a crisis undermines total factor productivity, which reduces the return to working and to accumulating physical capital. If the crisis is temporary, young agents will study now and work later. Human capital rises. To test our model we rely on inflation crises as our main empirical proxy. Using GMM panel procedures, our analysis for 86 countries in 1970-2000 confirms the positive effects of crises on human capi...

  8. APPLICATIONS OF SOCIAL CAPITAL THEORY

    OpenAIRE

    Schmid, A. Allan; Robison, Lindon J.

    1995-01-01

    Experiments and studies were conducted to investigate the role of social capital. Social capital (relationship to others) is a productive asset which is a substitute for and complement to other productive assets. The productivity of social capital leads to the expectation that firms and individuals invest in relationships. Data were collected to answer the following questions: Does the identity (relationship) of trading partners affect selling and buying prices; the acceptance of catastrophic...

  9. Capitalism and African business cultures

    OpenAIRE

    Taylor, Scott D.

    2014-01-01

    Scholars and practitioners once commonly linked 'African culture' to a distinctive 'African capitalism', at odds with genuine capitalism and the demands of modern business. Yet contemporary African business cultures reveal that a capitalist ethos has taken hold within both state and society. The success and visibility of an emergent, and celebrated, class of African big business reveals that business and profit are culturally acceptable. Existing theories of African capitalism are ill-equippe...

  10. Capital Flows and Central Banking

    OpenAIRE

    Gupta, Poonam

    2016-01-01

    Because of the steady liberalization of the capital account since the early 1990s and increased financial integration of the Indian economy, capital flows to India have moved in tandem with broad global trends. This paper looks at the extent to which India’s monetary policy has been affected by the ebbs and flows of the capital it receives. For ease of narration, the paper divides the post...

  11. Venture Capital and Innovation Strategies

    OpenAIRE

    Da Rin, M.; Penas, M.F.

    2015-01-01

    Venture capital is a specialized form of financial intermediation that often provides funding for costly technological innovation. Venture capital firms need to exit portfolio companies within about five years from the investment to generate returns for institutional investors. This paper is the first to examine the association of venture capital funding with a company’s choice of innovation strategies. We employ a unique dataset of over 10,000 innovative Dutch companies, some of which receiv...

  12. Human Capital and Genetic Diversity

    OpenAIRE

    Sequeira, Tiago; Santos, Marcelo,; Ferreira-Lopes, Alexandra

    2013-01-01

    The determinants of human capital have been studied sparsely in the literature. Although there is a huge literature on the determinants of schooling linked with the quality of schooling, there are not many contributions that explore the deep determinants of investment in, quantity and quality of human capital. This paper investigates the relationship between human capital and the ancestral genetic diversity of populations. It highlights a strong hump-shaped relationship between genetic divers...

  13. EUROPEAN VENTURE CAPITAL MARKET CHARACTERIZATION

    OpenAIRE

    Félix, Elisabete Gomes Santana

    2005-01-01

    In this work it was intended to carry through an analysis of the European venture capital market in the last eight years. Also it was done a summary of the venture capital industry history, carrying through a comparison between U.S.A. and Europe. In the European venture capital market analysis it was pointed out aspects about the investment totals, fundraising, investors types and investments types. Among others conclusions, it was found that the banks and pension funds are the main sup...

  14. A Capital Adequacy Buffer Model

    OpenAIRE

    David Allen; Michael McAleer

    2013-01-01

    In this paper, we develop a new capital adequacy buffer model (CABM) which is sensitive to dynamic economic circumstances. The model, which measures additional bank capital required to compensate for fluctuating credit risk, is a novel combination of the Merton structural model which measures distance to default and the timeless capital asset pricing model (CAPM) which measures additional returns to compensate for additional share price risk.

  15. 77 FR 52977 - Regulatory Capital Rules: Advanced Approaches Risk-Based Capital Rule; Market Risk Capital Rule

    Science.gov (United States)

    2012-08-30

    ... must assume a margin period of risk under the IMM of 20 business days for netting sets where: (1) The... Regulatory Capital Rules: Advanced Approaches Risk-Based Capital Rule; Market Risk Capital Rule; Proposed... 325 RIN 3064-AD97 Regulatory Capital Rules: Advanced Approaches Risk-Based Capital Rule; Market...

  16. Social Capital and Economic Growth

    OpenAIRE

    Reino Hjerppe

    1998-01-01

    It is argued in order to explain large differences in the level of the development and the growth of economies cannot be adequately explained only by looking the traditional inputs of labour, capital and natural resources. The hypothesis is that also the role of social capital needs to be taken into account. First the concept of social capital is defined and discussed. Then the role of social capital in the development process is explained. Empirical test based on the cross-country data of 27...

  17. Exploring the social capital grid

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Patulny, Roger

    2007-01-01

    The purpose of this paper is to show that numerous studies have advanced social capital research over the past decade. Most studies have accepted the theoretical distinction between bonding and bridging social capital networks. Many, however, tend to agglomerate empirical research under the one...... catch-all social capital concept, rather than classifying it according to the bonding/bridging distinction. Furthermore, most studies make little distinction on the basis of methodology, between qualitative and quantitative approaches to investigating social capital. These omissions need to be addressed....

  18. MODELS OF CAPITAL COSTS QUANTIFICATION

    OpenAIRE

    Tomáš KLIEŠTIK; Katarína VALÁŠKOVÁ

    2013-01-01

    The present contribution deals with the quantification of capital costs. The contribution is written on a theoretical basis. The costs will be particularly quantified in financing only by equity and only by debt capital and particularly in the so-called mixed financing in which weighted average costs of capital will be quantified. The cost of capital can be seen from three different perspectives: in the assets part of a company, in the liability part of a company and in the part of potential ...

  19. Building A Venture Capital Index

    OpenAIRE

    Liang Peng

    2001-01-01

    This paper builds a venture capital index from 1987 to 1999 that consists of 12,946 rounds of venture financing with 5,643 venture-backed firms. The paper uses two innovative techniques, a re-weighting procedure and a method of moment repeat sales regression, to mitigates three problems - missing data, censored data, and sample selection. We report the time series of capital flows, net asset value, and returns of the venture capital index. We find that the venture capital industry experienced...

  20. Social Capital, Value, and Measure: Antonio Negri's Challenge to Capitalism.

    Science.gov (United States)

    Day, Ronald E.

    2002-01-01

    Considers one concept in knowledge management, that of social capital, focusing on the problem of measure and value in capitalism, specifically within the period and conditions of post-Fordist production. Discusses the work of Antonio Negri and suggests the importance of knowledge management as a symptom of a turn in political economy. (Author/LRW)

  1. Human capital and optimal positive taxation of capital income

    NARCIS (Netherlands)

    B. Jacobs (Bas); A.L. Bovenberg (Lans)

    2010-01-01

    textabstractThis paper analyzes optimal linear and non-linear taxes on capital and labor incomes in a life-cycle model of human capital investment, financial savings, and labor supply with heterogenous individuals. A dual income tax with a positive marginal tax rate on not only labor income but also

  2. Comprehensive wealth, intangible capital, and development

    OpenAIRE

    Ferreira, Susana; Hamilton, Kirk

    2010-01-01

    Existing wealth estimates show that in most countries intangible capital is the largest share of total wealth. Intangible capital is calculated as the difference between total wealth and tangible (produced and natural) capital. This paper uses new estimates of total wealth, natural capital, and physical capital for a panel of countries to shed light on the constituents of the intangible ca...

  3. Growth Strategy with Social Capital and Physical Capital

    OpenAIRE

    Le Van, Cuong; Nguyen, Anh Ngoc; Nguyen, Ngoc-Minh

    2014-01-01

    Dans ce papier, nous étudions l'impact du capital social dans un modèle simple à la fois théorique et empirique. L'hypothèse cruciale est que le coût du capital physique, grâce aux contacts sociaux diminue par rapport aux dépenses en capital social. Dans le modèle théorique, nous montrons qu'il existe un seuil critique de l'épargne destinée aux dépenses en capital social. Les firmes dont l'épargne est inférieur à ce seuil ne vont pas investir en capital social. Nous montrons de plus que les p...

  4. 12 CFR 565.4 - Capital measures and capital category definitions.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Capital measures and capital category... PROMPT CORRECTIVE ACTION § 565.4 Capital measures and capital category definitions. (a) Capital measures. For purposes of section 38 and this part, the relevant capital measures shall be: (1) The total...

  5. 76 FR 11668 - Minimum Capital

    Science.gov (United States)

    2011-03-03

    ... amended. See 74 FR 5597 (January 30, 2009). As a result, the definition of ``minimum capital level'' as... by HERA. Final Rule: Capital Requirements for the Federal Home Loan Banks, 66 FR 8262, 8282-83... 12 U.S.C. 4612(d). The 60-day comment period closed on April 9, 2010. See Federal Register 75 FR...

  6. 75 FR 6151 - Minimum Capital

    Science.gov (United States)

    2010-02-08

    ... Cease and Desist Order, as amended. See 74 FR 5597 (January 30, 2009). As a result, the definition of... AGENCY 12 CFR Part 1225 RIN 2590-AA01 Minimum Capital AGENCY: Federal Housing Finance Agency. ACTION... Soundness Act that provides for a temporary increase in the minimum capital level for entities regulated...

  7. Business model and Intellectual Capital

    DEFF Research Database (Denmark)

    Lindgren, Peter; Saghaug, Kristin Margrethe

    2012-01-01

    When practicing business model (BM) innovation releasing intellectual capital (IC) strategically from SME´s BMs through the innovation process can be extremely difficult and complex to carry out especially to small and medium size enterprises (SME). There are so many opportunities and resources in...... SME´s Intellectual Capital – but how to release them?...

  8. Taxes and Venture Capital Support

    DEFF Research Database (Denmark)

    Keuschnigg, Christian; Nielsen, Søren Bo

    2003-01-01

    's success, but is not verifiable. Asa result, the market equilibrium is biased towards inefficiently low venture capitalsupport. The capital gains tax becomes especially harmful, as it further impairsadvice and causes a first-order welfare loss. Once the capital gains tax is in place,limitations on loss off...

  9. Operational risk economic capital allocation

    Science.gov (United States)

    Nikonov, Oleg I.; Vlasov, Vladimir E.; Medvedeva, Marina A.

    2013-10-01

    In the paper we describe a model of operational risk of economic capital estimation and allocation based on Loss Distribution Approach (LDA). Bank's total losses are modeled through Monte-Carlo simulations of its business units' losses. It allows to fairly distributing the corresponding capital between business units in order to assess and manage their risk adjusted performance.

  10. Solow Residuals Without Capital Stocks

    DEFF Research Database (Denmark)

    Burda, Michael C.; Severgnini, Battista

    2014-01-01

    investment expenditures: one eliminates the capital stock by direct substitution, while the other employs generalized differences of detrended data and the Malmquist index. In short samples, these measures can exhibit consistently lower root mean squared errors than the Solow–Törnqvist counterpart. Capital...

  11. ROMANIA’S CAPITAL MARKET

    OpenAIRE

    ROBERT SZABO; ILIE RĂSCOLEAN

    2008-01-01

    The book presents the features and the evolution of the capital market in Romania and also presents its role and efficiency in financing the economy. Also the book presents the participants in the capital market, which are defined as regulated entities, investors and issuers.

  12. Universities Venture into Venture Capitalism.

    Science.gov (United States)

    Desruisseaux, Paul

    2000-01-01

    Reports that some universities are starting their own venture-capital funds to develop campus companies, or are investing endowment funds with established venture-capital firms inclined to finance potential spinoffs from campus research. Examples cited are from the University of Alabama, Vanderbilt University (Tennessee), University of…

  13. Sand in the Wheels of Capitalism

    DEFF Research Database (Denmark)

    Bersem, Mario; Perotti, Enrico; von Thadden, Ernst-Ludwig

    rest receives only lab or income; and (ii) voters have different vintages of human capital. We identify young workers as the decisive voter group, with preferences in between capitalists who favor a free capital market, and old workers, who favor restricted capital mobility. We show that capital market......We present a positive theory of capital market frictions that raise the cost of capital for new firms and lower the cost of capital for incumbent firms. Capital market frictions arise from a political conflict across voters who differ in two dimensions: (i) a fraction of voters owns capital, the...... frictions do not naturally arise in a static framework, or even in a dynamic framework if capital market frictions are reversible. But if capital market frictions can be made to p ersist over time, we show that young workers favor capital market frictions as a way to smo oth income, especially if wealth is...

  14. A successful capital treadmill

    International Nuclear Information System (INIS)

    A summary of the operating economics of the Winter Cummings Sand Pool, a horizontal well development project with a sustained rate of development, was presented. A total of 58 horizontal wells have been drilled over a time span of seven years. The production performance of the first pilot wells indicated that development of the pool by horizontal wells could be economically viable. Since its inception the Winter field development was considered to have become a capital treadmill with an incremental rate of return on the incremental investment of 240 percent (a 24 million dollar net operating cash flow for a 10 million dollar investment). Current development status and production forecasts were also discussed. 21 figs

  15. Culture as Capital

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    A collection of essays 2011-2014 By following, and reproducing, the cultural turn, the rhetoric of cultural mix and hybridism is disseminated today primarily in its crossing of trade barriers. Cultures reduced to their exchange value function as capital - an accumulative, speculative and......, ultimately, financial affair. In some of its media and site-(un)specific manifestations, process art - which aims to encompass both old and new media art - seems to resist this pressure, despite, nonetheless, not being protected from regulations and incorporations. In the present collection of his recent...... essays, Slavko Kacunko discusses the process art by crossing the disciplines of art history and comparative media-, visual- and -cultural studies. As a first approximation, several historiographical remarks on closed-circuit video installations underline their importance as a core category of process art...

  16. International venture capital perspective

    International Nuclear Information System (INIS)

    'Full text:' The emerging fuel cell industry is characterized by global cooperation and partnerships in commercial, technical, and financial aspects. In this talk, we would like to provide observations about international venture capital focused on fuel cells globally. The talk will refer to experiences Conduit Ventures has had with its portfolio companies and other investors in various countries. We discuss our approach to working with portfolio companies who are geographically remote from our main office in London. We also discuss the process of making investment decisions on possible investments in various countries. The talk will conclude with insights and 'lessons learned' which may be of interest to fellow members of Fuel Cells Canada. (author)

  17. Capital Account Liberalization as a Signal

    OpenAIRE

    1996-01-01

    We present a model in which a government's current capital controls policy signals future policies. Controls on capital outflows evolve in response to news on technology, conditional on government attitudes towards taxation of capital. When there is uncertainty over government types, a policy of liberal capital outflows sends a favorable signal that may trigger a capital inflow. This prediction is consistent with the experience of several countries that have liberalized their capital account

  18. Uninsurable investment risks and capital income taxation

    OpenAIRE

    Césaire A. Meh; Terajima, Yaz

    2009-01-01

    This paper studies the capital accumulation and welfare implications of reducing capital income taxation in a general equilibrium economy with uninsurable investment risks. It has been shown that, with uninsurable investment risks, under-accumulation of capital may result compared to the complete markets economy. We show that reducing somewhat the capital income tax rate increases the capital stock and leads to a welfare gain. The complete elimination of the capital income tax, however, is no...

  19. Corruption, Public Expenditure, and Human Capital Accumulation

    OpenAIRE

    Spyridon Boikos

    2013-01-01

    In this paper we investigate the effect of corruption on human capital accumulation through two channels. The first channel is through the effect of corruption on the public expenditure on education and the second channel is through the effect of corruption on the physical capital investment. Public expenditure on education affects positively human capital, while physical capital can obsolete human capital. Initially, we construct an endogenous two-sector growth model with human capital accum...

  20. Capital regulation and banks' financial decisions

    OpenAIRE

    Zhu, Haibin

    2015-01-01

    This paper develops a stochastic dynamic model to examine the impact of capital regulation on banks' financial decisions. In equilibrium, lending decisions, capital buffer and the probability of bank failure are endogenously determined. Compared to a flat-rate capital rule, a risk-sensitive capital standard causes the capital requirement to be much higher for small (and riskier) banks and much lower for large (and less risky) banks. Nevertheless, changes in actual capital holdings are less pr...

  1. Intellectual capital: Evidence from banking industry

    OpenAIRE

    Somayeh Boostani; Shabnam Fotovvat; Karam Safari

    2014-01-01

    This paper investigates different components on intellectual capital including human capital, structural capital and customer capital in banking industry in city of Salmas, Iran. The study uses the questionnaire developed by Bontis (1998) [Bontis, N. (1998). Intellectual capital: an exploratory study that develops measures and models. Management Decision, 36(2), 63-76.] to measure the effects of human capital. The questionnaire consists of 42 questions and all of them are designed in Likert s...

  2. 78 FR 55339 - Regulatory Capital Rules: Regulatory Capital, Implementation of Basel III, Capital Adequacy...

    Science.gov (United States)

    2013-09-10

    ... Methodology a. Recognition of Wrong-Way Risk b. Increased Asset Value Correlation Factor 4. Credit Valuation... requirement for a ratio of common equity tier 1 capital to risk-weighted assets (common equity tier 1 capital... Provisions, Prompt Corrective Action, Standardized Approach for Risk-weighted Assets, Market Discipline...

  3. 78 FR 62417 - Regulatory Capital Rules: Regulatory Capital, Implementation of Basel III, Capital Adequacy...

    Science.gov (United States)

    2013-10-22

    ... comments that appeared in the Federal Register of September 10, 2013 (78 FR 55340), regarding Regulatory... NW., Washington, DC 20429. SUPPLEMENTARY INFORMATION: In FR Doc. 2013-21357, appearing on page 55518... Part 324 RIN 3064-AD95 Regulatory Capital Rules: Regulatory Capital, Implementation of Basel...

  4. National Capital Planning Commission Meeting Transcripts

    Data.gov (United States)

    National Capital Planning Commission — Transcripts of the monthly (with the exception of August) National Capital Planning Commission meeting transcripts are provided for research to confirm actions...

  5. Evaluation of the influence of parameters that determine the mean glandular dose in mammography using different detectors; Evaluacion de la influencia de los parametros que determinan la dosis glandular media en Mamografia utilizando diferentes detectores

    Energy Technology Data Exchange (ETDEWEB)

    Costa, K.; Nogueira, M. S., E-mail: katicostabh@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear, Pos-graduacao em Ciencias e Tecnologia das Radiacoes, Minerais e Materiais / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Mammography is a test used for early detection of breast cancer. The mean glandular dose (MGD) is dosimetric greatness accepted as indicative of carcinogenic risk induced by ionizing radiation in the breasts of women undergoing mammography exams. MGD value is estimated from the incident air kerma (k i), associated with conversion factors which depend on the half-value layer (HVL), the breast composition and thickness compressed breast. This study aims to evaluate the influence of the parameters used to determine the MGD using different measurement detectors. Measurements were performed on a Siemens Mammomat Model 300 Nova mammography equipment; this has the combinations Anode/Filter of Mo/Mo, Mo/Rh and W/Rh. Detectors used were the ionization chamber Model 10X6-6M manufactured by Radcal Co., two solid-state detectors, one Model AGMS-M manufactured by Radcal Co. and other Model Xi Mammo manufactured by UNFORS. The detectors measures were compared and the MGD value was estimated; differences between measurements and the reference values were higher in HVL and k i parameters. The results are displayed according to other published works. (Author)

  6. Immigrant Capital and Entrepreneurial Opportunities

    Directory of Open Access Journals (Sweden)

    Malavika Sundararajan

    2016-01-01

    Full Text Available Objective: The main objective of this study is to define and operationalize the concept of immigrant capital, a key factor that differentiates immigrant from host country entrepreneurs in how they recognize and start new ventures. Research Design & Methods: A detailed analysis of contemporary immigrant entrepreneurship and opportunity recognition literature was carried out. Using grounded theory, we synthesized the outcomes from the analysis of eight Canadian and U.S. case studies of successful immigrant entrepreneurs with the key findings from the literature to define and develop a model of immigrant capital. Findings: Based on our grounded theory development process we show that the concept of immigrant capital as a distillate of human, cultural, economic and social capital that goes beyond expected opportunity recognition (OR drivers like prior knowledge and prior experience to differentiate and enhance the immigrant entrepreneur’s ability to recognize business opportunities compared to host country entrepreneurs. We found immigrant capital to be a consequence of being boundary spanners in host and home country networks. Implications & Recommendations: Understanding a unique resource like immigrant capital, will help immigrant as well as host country entrepreneurs further develop their opportunity recognition ability by bridging gaps and fulfilling the needs for both, immigrant and host country consumers. Contribution & Value Added: The main contribution is the theoretical development, identification and definition of the immigrant capital model and propositions that will articulate the factors that lead to the conceptualization and operationalization of immigrant capital. Furthermore, the immigrant capital model can serve host country entrepreneurs to develop cross-cultural networks and jump-start entrepreneurial activities in their home countries as well as learn how to expand their operations into global markets.

  7. Intellectual capital: Evidence from banking industry

    Directory of Open Access Journals (Sweden)

    Somayeh Boostani

    2014-09-01

    Full Text Available This paper investigates different components on intellectual capital including human capital, structural capital and customer capital in banking industry in city of Salmas, Iran. The study uses the questionnaire developed by Bontis (1998 [Bontis, N. (1998. Intellectual capital: an exploratory study that develops measures and models. Management Decision, 36(2, 63-76.] to measure the effects of human capital. The questionnaire consists of 42 questions and all of them are designed in Likert scale. Cronbach alphas for human capital, structural capital and relationship capital were calculated as 0.79, 0.76 and 0.72, respectively. The implementation of Kolmogorov-Smirnov test has indicated that the data were normally distributed. Using t-student test, the study determined that while management team did not pay enough attention on human capital, there were some statistically significant evidence that social and relationship capitals gained good attention.

  8. Social capital in engineering education

    Science.gov (United States)

    Brown, Shane

    A theoretical argument is presented to suggest that engineering curriculum be designed to develop social capital. Additionally, the value of social capital in the retention of students in the College of Engineering, and the development, role, and value of social capital in an electrical engineering laboratory is evaluated. Data collected includes participant observations, informal and formal student interviews, and a researcher-designed survey. Social capital consists of interaction among individuals (networks), social rules that encourage interactions such as trust and reciprocity (norms), and the value of these networks and norms to the individual and the group. A large body of evidence suggests that social capital is valuable in terms of retention and multiple measures of academic achievement. The importance of social capital in retention was verified by students that have left engineering and those that remain, in terms of interactions with peers, teaching assistants, and engineering faculty; and a lack of sense of community in freshman engineering courses. Students that have left engineering differed in their perceptions of social capital from those that remain in their frustrations with teaching methods that encourage little discussion or opportunities to ask questions about assumptions or approaches. The open-ended nature of laboratory assignments, extensive required troubleshooting, and lack of specific directions from the teaching assistants were found to encourage the development of social capital in the laboratory setting. Degree centrality, a network measure of social capital as the number of ties an individual has within a social network, was found to be positively correlated with laboratory grade. Student perceptions of the importance of interactions with other students on success in the laboratory setting has a negative model effect on academic achievement in the laboratory. In contrast, student perceptions of the quality of interactions with

  9. Social capital and localised learning

    DEFF Research Database (Denmark)

    Lorenzen, Mark

    2007-01-01

      This conceptual paper analyses why social capital is important for learning and economic development, how it is created and its geography. It argues that with the rise of globalisation and learning-based competition, social capital is becoming valuable because it organises markets, lowering...... business firms' costs of co-ordinating and allowing them flexibly to connect and reconnect. The paper defines social capital as a matrix of various social relations, combined with particular normative and cognitive social institutions that facilitate co-operation and reciprocity, and suggests that social...

  10. Capital-imperialismo e neoliberalismo

    OpenAIRE

    Campagnaro, Yuri Gabriel

    2014-01-01

    Resumo: O marxismo interpreta o imperialismo desde Hilferding, com sua análise do capital financeiro em 1910. Lenin sintetizou o primeiro debate, caracterizando o imperialismo como uma nova fase do capitalismo, com monopólios e maior centralização do capital. O debate se estende à década de 1970 com Mandel, que identificou uma alteração na morfologia do capital de então. Os autores contemporâneos debatem o período do capitalismo após os anos 1970, entre eles David Harvey e Virgínia Fontes. Ch...

  11. Emerging Forms of Cultural Capital

    DEFF Research Database (Denmark)

    Prieur, Annick; Savage, Mike

    2013-01-01

    This paper takes stock of recent research on patterns of cultural engagement in various European nations, with specific reference to British and Danish research. It argues that Bourdieu's original theorisation of cultural capital in ‘Distinction’ needs to be significantly updated to register the...... decline of ‘highbrow’ culture which these studies reveal. However, we argue that this shift does not entail the erosion of cultural capital itself, or the rise of the ‘cultural omnivore’, so much as the emergence of a form of ‘cosmopolitan cultural capital’. We argue that this emerging cultural capital...

  12. Capitalism, Socialism and Public Choice

    Directory of Open Access Journals (Sweden)

    Adrián Osvaldo Ravier

    2010-10-01

    Full Text Available The essay examines Schumpeter’s understanding of the capitalist process and develops a critical analysis of his explanation of why capitalism cannot survive. Part I deals with how Schumpeter understood capitalism. Part II studies why –- from his point of view — capitalism couldn’t survive. Part III analysis why it is actually socialism, as a socio-political alternative, that is impractical and must collapse from contradictions inherent in it. Part IV presents some final reflections, presenting the public choice and the thought of James M. Buchanan, as an alternative to the pessimist Schumpeterian view.

  13. Morphological variation of non-glandular hairs in cultivated Epimedium sagittatum (Berberidaceae populations and implications for taxonomy

    Directory of Open Access Journals (Sweden)

    Yanqin Xu

    2013-03-01

    Full Text Available We investigated the morphological variations of non-glandular hairs across 16 cultivated Epimedium sagittatum (Berberidaceae populations using digital photomicrography. The main features examined included the total numbers of cells, the full-length and ratio of the first cell, the angle and connection pattern between the first and adjacent cells, the presence of elongated cell(s, and the shape, diameter and cell wall thickness of the first cell. Of these, the shape of the first cell was the most important variable and was associated with such characters as the full length, the presence of elongated cell(s, the ratio of the first cell, and the diameter and cell wall thickness of the first cell. Morphological diversity among populations was significant with two main groups identified, namely as sword-shaped group and a fusiform group. However, variations of the main characters was continuous among individuals and populations, suggesting that E. sagittatum was possibly a polytypic species. Adaptive divergence of key traits between populations caused by natural selection was also possible. The genetic basis of variation was evidenced by morphological differences maintained among populations cultivated in a common garden. Phenotypic divergence between ecologically separated populations could be the result of local adaptation.

  14. Evaluation of the influence of parameters that determine the mean glandular dose in mammography using different detectors

    International Nuclear Information System (INIS)

    Full text: Mammography is a test used for early detection of breast cancer. The mean glandular dose (MGD) is dosimetric greatness accepted as indicative of carcinogenic risk induced by ionizing radiation in the breasts of women undergoing mammography exams. MGD value is estimated from the incident air kerma (k i), associated with conversion factors which depend on the half-value layer (HVL), the breast composition and thickness compressed breast. This study aims to evaluate the influence of the parameters used to determine the MGD using different measurement detectors. Measurements were performed on a Siemens Mammomat Model 300 Nova mammography equipment; this has the combinations Anode/Filter of Mo/Mo, Mo/Rh and W/Rh. Detectors used were the ionization chamber Model 10X6-6M manufactured by Radcal Co., two solid-state detectors, one Model AGMS-M manufactured by Radcal Co. and other Model Xi Mammo manufactured by UNFORS. The detectors measures were compared and the MGD value was estimated; differences between measurements and the reference values were higher in HVL and k i parameters. The results are displayed according to other published works. (Author)

  15. Capital humain, mobilité du capital et commerce international

    OpenAIRE

    Pierre VILLA

    1998-01-01

    The outsourcing of activities have been taking a peculiar shape recently. Human capital has remote control of the factories which are produced according to the local technology, and it defines the home technology in which it commits these factories and is committed itself. We introduce this idea in a hierarchical model of international trade with two countries, three factors and two final goods: the traditional one produced with labour and capital and the modern one produced with a non traded...

  16. Human Capital Investment, Cash Flow Risk and Capital Structure Dynamics

    OpenAIRE

    Zhang, Xiaolan

    2014-01-01

    My dissertation explores the financial effects of firms' growing reliance on intangible capital in their production technology. I examine the fundamental link between the cash flow risk, financial decision-making and the accumulation of firm-level intangible capital both in theory and in empirics. In Chapter one, I document that public firms in the United States that provide better insurance against productivity shocks to their workers experience higher cash flow volatility. Difference in i...

  17. Conventional capital, criminal capital, and criminal careers in drug trafficking

    OpenAIRE

    Wang, Wei

    2013-01-01

    Although the criminal career paradigm has explored various crime types, little effort has been conducted to systematically examine the pattern of drug trafficking careers. Ethnographic studies on drug trafficking have proposed that different forms of capital have an impact on the patterns of drug trafficking careers. The effects of conventional and criminal capital, however, have been the subject of much less empirical attention. Drawing from information on the criminal careers of 182 incarce...

  18. Internal capital markets and capital structure: bank versus internal debt.

    OpenAIRE

    Dewaelheyns, Nico; Van Hulle, Cynthia

    2007-01-01

    Recent empirical evidence has shown that internal capital markets within multinational corporations are used to reduce overall financing costs by optimizing the mix of internal and external debt of affiliates in different countries. We show that this cost saving use of internal capital markets is not limited to multinationals, but that domestic business groups actively optimize the internal/external debt mix across their subsidiaries as well. We use both subsidiary and group level financial s...

  19. Triage of Atypical Glandular Cell by SOX1 and POU4F3 Methylation: A Taiwanese Gynecologic Oncology Group (TGOG) Study

    OpenAIRE

    Chang, Cheng-Chang; Ou, Yu-Che; Wang, Kung-Liahng; Chang, Ting-Chang; Cheng, Ya-Min; Chen, Chi-Hau; Chu, Tang-Yuan; Hsu, Shih-Tien; Liou, Wen-Shiung; Chang, Yin-Yi; Wu, Hua-Hsi; Chen, Tze-Ho; Lai, Hung-Cheng

    2015-01-01

    Introduction Invasive procedures including loop electrosurgical excision, cervical conization, and endometrial sampling are often recommended when atypical glandular cells (AGC) are detected on Pap smear with unsatisfactory colposcopy. These invasive procedures may result in patient anxiety, increased medical expense, and increasing the risk of preterm delivery in subsequent pregnancies. This study was performed to assess methylation biomarkers in the triage of AGC on Pap smear for invasive p...

  20. Two IIIf Clade-bHLHs from Freesia hybrida Play Divergent Roles in Flavonoid Biosynthesis and Trichome Formation when Ectopically Expressed in Arabidopsis

    Science.gov (United States)

    Li, Yueqing; Shan, Xiaotong; Gao, Ruifang; Yang, Song; Wang, Shucai; Gao, Xiang; Wang, Li

    2016-01-01

    The MBW complex, comprised by R2R3-MYB, basic helix-loop-helix (bHLH) and WD40, is a single regulatory protein complex that drives the evolution of multiple traits such as flavonoid biosynthesis and epidermal cell differentiation in plants. In this study, two IIIf Clade-bHLH regulator genes, FhGL3L and FhTT8L, were isolated and functionally characterized from Freesia hybrida. Different spatio-temporal transcription patterns were observed showing diverse correlation with anthocyanin and proanthocyanidin accumulation. When overexpressed in Arabidopsis, FhGL3L could enhance the anthocyanin accumulation through up-regulating endogenous regulators and late structural genes. Unexpectedly, trichome formation was inhibited associating with the down-regulation of AtGL2. Comparably, only the accumulation of anthocyanins and proanthocyanidins was strengthened in FhTT8L transgenic lines. Furthermore, transient expression assays demonstrated that FhGL3L interacted with AtPAP1, AtTT2 and AtGL1, while FhTT8L only showed interaction with AtPAP1 and AtTT2. In addition, similar activation of the AtDFR promoter was found between AtPAP1-FhGL3L/FhTT8L and AtPAP1- AtGL3/AtTT8 combinations. When FhGL3L was fused with a strong activation domain VP16, it could activate the AtGL2 promoter when co-transfected with AtGL1. Therefore, it can be concluded that the functionality of bHLH factors may have diverged, and a sophisticated interaction and hierarchical network might exist in the regulation of flavonoid biosynthesis and trichome formation. PMID:27465838

  1. Two IIIf Clade-bHLHs from Freesia hybrida Play Divergent Roles in Flavonoid Biosynthesis and Trichome Formation when Ectopically Expressed in Arabidopsis.

    Science.gov (United States)

    Li, Yueqing; Shan, Xiaotong; Gao, Ruifang; Yang, Song; Wang, Shucai; Gao, Xiang; Wang, Li

    2016-01-01

    The MBW complex, comprised by R2R3-MYB, basic helix-loop-helix (bHLH) and WD40, is a single regulatory protein complex that drives the evolution of multiple traits such as flavonoid biosynthesis and epidermal cell differentiation in plants. In this study, two IIIf Clade-bHLH regulator genes, FhGL3L and FhTT8L, were isolated and functionally characterized from Freesia hybrida. Different spatio-temporal transcription patterns were observed showing diverse correlation with anthocyanin and proanthocyanidin accumulation. When overexpressed in Arabidopsis, FhGL3L could enhance the anthocyanin accumulation through up-regulating endogenous regulators and late structural genes. Unexpectedly, trichome formation was inhibited associating with the down-regulation of AtGL2. Comparably, only the accumulation of anthocyanins and proanthocyanidins was strengthened in FhTT8L transgenic lines. Furthermore, transient expression assays demonstrated that FhGL3L interacted with AtPAP1, AtTT2 and AtGL1, while FhTT8L only showed interaction with AtPAP1 and AtTT2. In addition, similar activation of the AtDFR promoter was found between AtPAP1-FhGL3L/FhTT8L and AtPAP1- AtGL3/AtTT8 combinations. When FhGL3L was fused with a strong activation domain VP16, it could activate the AtGL2 promoter when co-transfected with AtGL1. Therefore, it can be concluded that the functionality of bHLH factors may have diverged, and a sophisticated interaction and hierarchical network might exist in the regulation of flavonoid biosynthesis and trichome formation. PMID:27465838

  2. Use of a new breast phantom for dosimetric determination of incident air kerma and mean glandular dose in digital mammography system

    International Nuclear Information System (INIS)

    Mammography aims to achieve a high image quality associated with a dose in the patient as low as feasible. Values of average glandular dose, DG, can be obtained by means of two dosimetric methods: one based on the measurement of incident air kerma, Ki, associated with tables of conversion factors that depend on the half value layer, the thickness and the glandular composition of the breast. And the one that makes the measure directly to thermoluminescent dosimeters, TLDs, placed in a new dosimetric phantom. Thus, this study aims to determine the incident air kerma (Ki) and average glandular dose (DG) applied on patients in a digital mammography system (DR) using the phantom dosimetric developed. Another objective is to compare the results with the values of DG determined from Ki and also with the values of Ki and DG indicated in the examination of each patient by the digital mammography unit. The result of the average values measured in 77 patients with compressed breast thickness within the range of 5.5 cm and 6.5 cm, shows that the Ki values ranged around 7.9% between the methods of action. The result of the values of DG ranged around 14.7% between the two methods of action. It is observed that the estimate of DG by the software is higher than the values measured with the dosimetric phantom. (author)

  3. The Valuation of Organizational Capital

    Directory of Open Access Journals (Sweden)

    Fiala Roman, Borůvková Jana

    2012-12-01

    Full Text Available The authors’ aim was to create a model suitable for measuring organization capital. This model was produced by means of the Forward and Backward Stepwise methods, on the basis of company information. Low p-levels (approaching 0 show the statistical significance of all regression coefficients, including the intercept. Organizational capital of 2,796 companies in the Czech Republic was quantified. A statistically significant correlation between organizational capital and return on equity (ROE, as well as between organizational capital and return on assets (ROA, has been established. This article is a part of the results of the project No. 402/09/2057 ‘‘Measurement and Management of Intangible Assets Impact on Firm Performance’’ financed by Czech Science Foundation.

  4. Corporate governance and intellectual capital

    Directory of Open Access Journals (Sweden)

    Rahmat Alizadeh

    2014-01-01

    Full Text Available The purpose of this paper is to examine the association between corporate governance and Intellectual capital in the pharmaceutical companies accepted in Tehran Stock Exchange over the period 2004-2009 using a regression based model. The study investigates the impacts of three some independent variables of the corporate governance (i.e. the number of board members, the relative extent of nonexecutive to executive directors, the auditing committee. The results suggest that corporate governance had no special effect on intellectual capital in the pharmaceutical companies. Furthermore among corporate governance's variables, the first one (i.e. board size had negative impact on firms' intellectual capital and the second and the third variables had no effects on intellectual capital.

  5. Emerging Forms of Cultural Capital

    DEFF Research Database (Denmark)

    Prieur, Annick; Savage, Mike

    activities themselves - the claims that there are forms of emotional, subcultural or national cultural capital at work - The claim about cosmopolitanism or an international orientation as a distinctive feature of the culturally privileged classes The paper responds to the first theme announced in the call......This paper reviews recent European studies to assess whether cultural capital now has the same characteristics – or may be rather the same functions - as when Distinction was written. The paper will examine empirical applications of the concept of cultural capital in leading European studies in...... hence are highly appropriate for direct comparisons with that study. This paper will begin by raising general issues regarding the meaning of the concept, and about how one may make assessments and claims about cultural capital. Here we consider how the legitimacy of certain cultural competencies or...

  6. Oligopoly banking and capital accumulation

    OpenAIRE

    Nicola Cetorelli; Pietro F. Peretto

    2000-01-01

    We develop a dynamic general equilibrium model of capital accumulation where credit is intermediated by banks operating in a Cournot oligopoly. The number of banks affects capital accumulation through two channels. First, it affects the quantity of credit available to entrepreneurs. Second, it affects banks' decisions to collect costly information about entrepreneurs, and thus determines the efficiency of the credit market. We show that under plausible conditions, the market structure that ma...

  7. International Capital Movements Under Uncertainty

    OpenAIRE

    1983-01-01

    In this paper, we analyze the determinants of international movements of physical capital in a model with uncertainty and international trade in goods and securities.In our model, the world allocation of capital is governed, to some extent, by the asset preferences of risk averse consumer-investors. In a one-good variant in the spirit of the MacDougall model, we find that relative factor abundance, relative labor force size and relative production riskiness have separate but interrelated infl...

  8. Capital budgeting and procurement practices

    OpenAIRE

    Philippe Burger; Ian Hawkesworth

    2013-01-01

    Capital investment is a key function of government. However, for a number of reasons it has proven difficult for governments to ensure that capital investment represents value for money, is affordable, and is budgeted and accounted for in a prudent and transparent manner. This article discusses these challenges facing governments. Using the findings of a survey conducted among OECD countries and enhanced engagement countries in 2012, this article provides an overview of what governments are d...

  9. Linguistic Capitalism and Algorithmic Mediation

    OpenAIRE

    Kaplan, Frédéric

    2014-01-01

    Google’s highly successful business model is based on selling words that appear in search queries. Organizing several million auctions per minute, the company has created the first global linguistic market and demonstrated that linguistic capitalism is a lucrative business domain, one in which billions of dollars can be realized per year. Google’s services need to be interpreted from this perspective. This article argues that linguistic capitalism implies not an economy of attention but an ec...

  10. OVERVIEW OF CAPITAL STRUCTURE THEORY

    OpenAIRE

    Taha, Roshaiza; SANUSI Nur Azura

    2014-01-01

    The aim of this paper is to provide a comprehensive review on two major theories of capital structure; pecking order theory and static-trade off theory in regard with achieving an optimal capital structure. Researchers believed bankruptcy costs, transactions costs, agency conflicts, adverse selection and taxes has been attribute as major explanations of the corporate used of debt financing which has been used as an argument in both theory. To date there is no consensus on the existing of opti...

  11. The hypothesis of cognitive capitalism

    OpenAIRE

    Vercellone, Carlo

    2005-01-01

    The aim of this presentation is to introduce some aspects of the research programme on Cognitive Capitalism. The main point that characterises this research program resides in the fact that it assume as its main pillar the social crisis of Fordism. Such a crisis manifests itself as a break with respect to the polarising tendency of the forms of knowledge informing Industrial Capitalism, thereby, realising some aspects of Marx's hypotheses concerning the notion of General Intellect. Accordingl...

  12. THE IMPORTANCE OF VENTURE CAPITAL

    Directory of Open Access Journals (Sweden)

    IRINA ANGHEL-ENESCU

    2013-05-01

    Full Text Available Created in the United States of America, Venture Capital is an asset class which attracted recently the attention of the policy makers all over the world. But the concept is still not clearly defined and understood. This paper attempts at introducing in the concept, its characteristics, and reviewing some of the benefits Venture Capital investments can bring at both the macroeconomic level, by looking at the correlation with the economic growth, and at the microeconomic level, for the portfolio companies.

  13. Capital, finance, and trade collapse

    OpenAIRE

    Yang Jiao; Yi Wen

    2012-01-01

    This paper proposes a model of international trade with capital accumulation and financial intermediation. This is achieved by embedding the Melitz (2003) model into an incomplete-markets neoclassical framework with an endogenous credit market. The model preserves the analytical tractability of the original Melitz model despite non-trivial distribution of firms’ net worth and capital stocks. We use the model to examine the differential effects of financial and non-financial shocks on aggregat...

  14. The Era of Super Capitalism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The world has entered the "super capitalism" era when one third of its economic activities are controlled by less than 3 percent of global financial capital. This year,a global economic recession,triggered by the U.S. subprime mortgage crisis,seems unavoidable. To tackle international financial problems,Tao Dong,Chief Economist for Asia at Credit Suisse First Boston in Hong Kong,shared his insights with China Business Journal. Excerpts follow.

  15. Insider Ownership and Capital Constraints

    OpenAIRE

    Hobdari, Bersant

    2007-01-01

    We analyze the impact of corporate governance structures on access to capital using a unique and rich panel data for a large and representative sample of Estonian firms over the period 1993 through 1999. We distinguish among five different governance structures and provide estimates on the impact of each of them on capital constraints. Our results indicate that: (i) separate regimes exist in investment behavior; (ii) the likelihood of being financially constrained is higher in firms that are ...

  16. Stock market and capital market

    OpenAIRE

    Dziková, Iveta

    2012-01-01

    The bachelor thesis provides an overview of selected topics related to the capital market. For completeness, the first part deals with the financial market whose characteristics can then be applied to the capital market. Furthermore, the stock exchange with its important features is introduced as well as the over-the-counter market, which is recently undergoing dramatic changes. Investment instruments are also listed in the thesis and the nature of the individual groups that make up the finan...

  17. Asset Pricing with Home Capital

    OpenAIRE

    Michal Pakos

    2008-01-01

    I analyze a stylized consumption-based asset pricing model that features heterogeneous agents and household capital, and discover a novel recession risk factor related to the cross-sectional second moments of the corresponding investments into such home capital. In order to fully isolate the orthogonal effects at work, I completely shut off the well-known mechanism of Constantinides and Duffie (1996) by explicitly stipulating homoscedastic cross-sectional distribution of nondurable goods and ...

  18. Bridges in social capital: A review of the definitions and the social capital of social capital researchers

    OpenAIRE

    Akcomak, Semih

    2009-01-01

    There has been a recent surge of interest in social economics and social capital. Articles on social capital that are published in the last five years constitute more than 60 percent of all articles on social capital. Research on social capital is now massive and spans sociology, economics, management, political science and health sciences. Despite this interest there is still not a consensus on the definition and the measurement of social capital. This paper argues that this is due to lack o...

  19. 12 CFR 208.4 - Capital adequacy.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Capital adequacy. 208.4 Section 208.4 Banks and... Requirements § 208.4 Capital adequacy. (a) Adequacy. A member bank's capital, as defined in appendix A to this... light of all the circumstances, the bank's capital appears inadequate in relation to its...

  20. 47 CFR 32.4540 - Other capital.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Other capital. 32.4540 Section 32.4540... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.4540 Other capital. This... capital stock, capital recorded upon the reorganization or recapitalization of the company and...

  1. Social Capital and Economic Well-being

    OpenAIRE

    Munshi Sulaiman; Farhad Ameen

    2007-01-01

    The proposition that social capital expands household welfare is tested by estimating the effects of social interactions on per capita expenditure among a sample of 810 households in northern Bangladesh. Using data from BRAC’s 2004 Social Capital Survey, ordinary least square (OLS) estimates isolate the differential effects of physical assets, human capital, and social capital [CFPR WP 16].

  2. RETROSPECTIVE OF FINANCIAL REPORTING ON CAPITAL MARKET

    OpenAIRE

    Diana Muresan

    2012-01-01

    The purpose of this paper is to develop a conceptual framework for the evolution offinancial reporting on capital market. Due to the worlwide changes, the role of financial reportingin capital market is constantly growing. Financial reporting analyzed through market perspective isstrongly correlated with issues like: capital allocation, financial statements, internationalaccounting standards and informational valences. Capital market research emphasizes the need forqualitative and transparent...

  3. Effect of Capital Markets on Environment

    OpenAIRE

    Dr. Rohit N. Desai

    2012-01-01

    Capital market is the market which gives capital to the business and individual enterprises. It generates capitalfor the long term and short term requirements of the capital market.There are three components of the Capital Market:1. Stock Market,2. Money Market,3. Foreign Exchange Market.

  4. Transmission line capital costs

    International Nuclear Information System (INIS)

    The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy's Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs

  5. 12 CFR 303.241 - Reduce or retire capital stock or capital debt instruments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Reduce or retire capital stock or capital debt... RULES OF PRACTICE FILING PROCEDURES Other Filings § 303.241 Reduce or retire capital stock or capital... or preferred stock, or to retire any part of its capital notes or debentures pursuant to section...

  6. Distributional consequences of capital tax coordination

    OpenAIRE

    2005-01-01

    This paper has two ambitions. First, we review the economic literature on tax coordination. Second, we argue that the taxation of capital is not an issue of efficiency, but instead an issue of equity. In particular, capital tax coordination can alter the vertical distribution of income between the production factors capital and labour. Capital is in perfectly elastic supply in a small open economy. Therefore the tax incidence falls to the immobile factor, labour. By contrast, capital is in in...

  7. Dynamic Programming, Maximum Principle and Vintage Capital

    OpenAIRE

    Fabbri, Giorgio; Iacopetta, Maurizio

    2007-01-01

    We present an application of the Dynamic Programming (DP) and of the Maximum Principle (MP) to solve an optimization over time when the production function is linear in the stock of capital (Ak model). Two views of capital are considered. In one, which is embraced by the great majority of macroeconomic models, capital is homogeneous and depreciates at a constant exogenous rate. In the other view each piece of capital has its own finite productive life cycle (vintage capital). The interpretatio...

  8. Financial Integration, Technology Differences and Capital Flows

    OpenAIRE

    Sebastián Claro

    2005-01-01

    The one-to-one mapping between cross-country differences in capital returns and the size and direction of international capital flows after financial integration vanishes in a multi-sector world with a laborintensive non-tradable sector if financial liberalization generates significant swings in the demand for the non-tradable good. For example, a high return to capital country may become an exporter of capital after financial integration if access to world capital markets enhances demand for...

  9. Indian Banks’ Methods for Assessing Working Capital

    OpenAIRE

    Malhotra Gunjan; Shastry Vikram; Sinharay Soumyadeep

    2010-01-01

    Working Capital is the capital required for by a firm to sustain its day to day activities. Different firms have different approaches to finance their working capital needs. After receiving proposals for working capital loans, as a precaution banks need to assess the amount of working capital loan which can be granted and also to determine the interest rate at which the loan can be provided. The RBI and its committees have introduced new methods for the calculation of credit eligibility for t...

  10. Natural Capital: From Metaphor to Measurement

    OpenAIRE

    FENICHEL, ELI P.; Abbott, Joshua K.

    2014-01-01

    Current efforts to value ecosystem services have contributed little to the valuation of natural capital, suggesting that in practice "nature is capital" primarily serves as a metaphor. We provide a theoretically motivated approach for recovering natural capital prices that expands beyond idealized management to encompass current, likely inefficient, management institutions. Theoretically consistent capital valuation requires adjusting for the net marginal productivity of the natural capital a...

  11. Intellectual Capital Management in Transport Sector

    OpenAIRE

    Asta Znakovaitė; Arnoldina Pabedinskaitė

    2011-01-01

    This article presents an analysis of intellectual capital; its management, features and processes by which intellectual capital of a company can be evaluated. The main elements of intellectual capital (human, structural and relationship capital) are presented and used in research. After surveying bibliography, intellectual capital evaluation model, which applies to Lithuanian and Latvian companies operating in the transport sector, is created. The research is based on the value-added intellec...

  12. Measuring Community Strength and Social Capital

    OpenAIRE

    Stimson, Robert; Western, John; Baum, Scott; Gellecum, Yolanda Van

    2003-01-01

    In 2001/02 five case study communities in both metropolitan and regional urban locations in Australia were chosen as test sites to develop measures of community strength on four domains: natural capital; produced economic capital; human capital; and social and institutional capital. Secondary data sources were used to develop measures on the first three domains. For the fourth domain?social and institutional capital?primary data collection was undertaken through sample surveys of households. ...

  13. When Should Firms Invest in Old Capital?

    OpenAIRE

    Boyan Jovanovic

    2008-01-01

    This paper studies optimal investment policies when the production function depends on capital of various vintages. In such an environment it is natural to ask whether the firm will invest in old-vintage capital at all. In this paper I derive such a condition. Predictably, investment in old capital takes place if the elasticity of substitution between old and new capital is low, and when the depreciation of capital is high. But other parameters such as the rates of technological progress and ...

  14. Toward A Reliable Cost of Capital

    OpenAIRE

    Jeremiah U. Idialu; Amos O. Arowoshegbe

    2013-01-01

    This is study is designed to provide basis for determining a reliable cost of capital. Corporate finance textbooks typically devote several chapters to the problems of capital budgeting, cash flow estimation and the determination of a firm’s cost of capital. However, it can be difficult in practice to obtain reliable estimates of the inputs required to perform capital budgeting as recommended by the textbooks. Also, the Weighted Average Cost of Capital (WACC) is commonly presented in a way th...

  15. Illegal Immigration: Optimal Enforcement and Capital Mobility

    OpenAIRE

    Subhayu Bandyopadhyay

    2005-01-01

    This paper analyzes the effectiveness of enforcement in controlling illegal immigration in two scenarios, capital mobility and capital immobility in the host nation (for illegal immigrants). The source nation is assumed throughout to have immobility of capital. We show that the net enforcement expenditure is higher (lower) in the presence of capital mobility if the host nation is an importer (exporter) of capital at the target immigration level. Furthermore, we show that if the host nation is...

  16. Impact of venture capital on economic development

    OpenAIRE

    Laurinavičius, Antanas

    2014-01-01

    Object of the research is public venture capital as a tool of venture capital market incentive, innovative business start-up financing, and state policy, which helps addressing imperfect/inefficient market situations where private venture capital does not access all market players. Purpose of the research is to reveal the importance of public venture capital to the national venture capital sector, its impact on the economy and, based on the experience of European countries, to create a hypoth...

  17. Intangible Capital, Corporate Valuation and Asset Pricing

    OpenAIRE

    Danthine, Jean-Pierre; Xiangrong JIN

    2006-01-01

    Recent studies have found unmeasured intangible capital to be large and important. In this paper we observe that by nature intangible capital is also very different from physical capital. We find it plausible to argue that the accumulation process for intangible capital differs significantly from the process by which physical capital accumulates. We study the implications of this hypothesis for rational firm valuation and asset pricing using a two-sector general equilibrium model. Our main fi...

  18. Mapping Italy’s social capital

    OpenAIRE

    Fabio Sabatini

    2007-01-01

    The contribution of this paper to the social capital literature is threefold. It first develops an innovative framework for measuring social capital, which allows for quantification of five different components of the multidimensional concept of social capital. Secondly, it provides a single, synthetic measure capturing that particular configuration of social capital which the literature generally associates with positive economic outcomes. Thirdly, it maps Italian social capital endowments f...

  19. Mammography radiation dose: Initial results from Serbia based on mean glandular dose assessment for phantoms and patients

    International Nuclear Information System (INIS)

    The primary objective of this study is to investigate the actual mammography dose levels in Serbia and establish a baseline dose database for the future screening programme. The mean glandular dose (MGD) was assessed for standard size breast substituted by 45 mm polymethyl methacrylate (PMMA) phantom and imaged under typical clinical conditions at 30 screen film mammography facilities. Average MGD was (1.9 ± 1.0) mGy, with a range of 0.12-5.2 mGy. These results were used for the calculation of the initial diagnostic reference levels in mammography in Serbia, which was set to 2.1 mGy for a standard breast. At some facilities, high doses were observed and the assessed MGD was supplemented by a patient dose survey. MGD was measured for 53 women having a diagnostic mammography in cranio-caudal (CC) and medio-lateral oblique (MLO) projections at the largest mammography facilities in Serbia. The parameters recorded were: age, compressed breast thickness, tube potential (in kV), tube loading (in mAs) and the MLO projection angle. The average MGD per image was 2.8 mGy for the CC projection and 4.3 mGy for the MLO projection. Dose to breast was compared with dose for PMMA phantoms of various sizes, assessed at the same facilities. The results have indicated that phantom dose values can assist in setting optimisation activities in mammography. Both phantom and patient dose values indicated unnecessary high doses in facilities with an extremely high mammography workload. For these facilities, urgent dose-reduction measures and follow-up actions were recommended. (authors)

  20. Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias: Results from a European multinational epidemiological study.

    Science.gov (United States)

    Holl, Katsiaryna; Nowakowski, Andrzej M; Powell, Ned; McCluggage, W Glenn; Pirog, Edyta C; Collas De Souza, Sabrina; Tjalma, Wiebren A; Rosenlund, Mats; Fiander, Alison; Castro Sánchez, Maria; Damaskou, Vasileia; Joura, Elmar A; Kirschner, Benny; Koiss, Robert; O'Leary, John; Quint, Wim; Reich, Olaf; Torné, Aureli; Wells, Michael; Rob, Lukas; Kolomiets, Larisa; Molijn, Anco; Savicheva, Alevtina; Shipitsyna, Elena; Rosillon, Dominique; Jenkins, David

    2015-12-15

    Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providing uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type-distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461) from 17 European countries, using centralised pathology review and sensitive HPV testing. The highest HPV-positivity rates were observed in AIS (93.9%), ASC (85.6%), and usual-type ADC (90.4%), with much lower rates in rarer ADC subtypes (clear-cell: 27.6%; serous: 30.4%; endometrioid: 12.9%; gastric-type: 0%). The most common HPV types were restricted to HPV16/18/45, accounting for 98.3% of all HPV-positive ADC. There were variations in HPV prevalence and ADC type-distribution by country. Age at diagnosis differed by ADC subtype, with usual-type diagnosed in younger women (median: 43 years) compared to rarer subtypes (medians between 57 and 66 years). Moreover, HPV-positive ADC cases were younger than HPV-negative ADC. The six years difference in median age for women with AIS compared to those with usual-type ADC suggests that cytological screening for AIS may be suboptimal. Since the great majority of CGN are HPV16/18/45-positive, the incorporation of prophylactic vaccination and HPV testing in cervical cancer screening are important prevention strategies. Our results suggest that special attention should be given to certain rarer ADC subtypes as most appear to be unrelated to HPV. PMID:26096203