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Sample records for mature leaves stems

  1. Comparison of total phenolic content, scavenging activity and HPLC-ESI-MS/MS profiles of both young and mature leaves and stems of Andrographis paniculata.

    Science.gov (United States)

    Chua, Lee Suan; Yap, Ken Choy; Jaganath, Indu Bala

    2013-12-01

    The total phenolic content and radical scavenging activity of Andrographis paniculata has been investigated to estimate the amount of phenolic compounds and diterpene lactones, respectively in the plant extracts. The stem extracts exhibited higher total phenolic content and scavenging activity than those of the leaf extracts from both young and mature plants. A range of 19.6-47.8 mg extract of A. paniculata from different parts of the plant is equivalent to the scavenging activity exhibited by one mg of standard Trolox. HPLC-ESI-MS/MS was also used to identify simultaneously the phytochemicals from the leaves and stems of both young and mature plant samples. Of the identified compounds, seven of the sixteen diterpene lactones, three of the six flavonoids, five of the six phenolic acids and two cyclic acids are reported here for the first time for this species. Multivariate statistical approaches such as Hierarchiral Component Analysis (HCA) and Principle Component Analysis (PCA) have clustered the plant extracts into the leaf and stem groups, regardless of plant age. Further classification based on the phytochemical profiles revealed that mostly phenolic acids and flavonoids were from the young leaf extracts, and diterpenoids and their glycosides from the mature leaf extracts. However, the phytochemical profiles for the stems of both young and mature plants were not significantly different as presented in the dendrogram of HCA and the score plot of PCA. The marker for mature plants might be the m/z 557 ion (dihydroxyl dimethyl 19-[(beta-D-glucopyranosyl)oxy]-19-oxo-ent-labda-8(17),13-dien-16,15-olide), whereas the m/z 521 ion (propyl neoandrographolide) could be the marker for leaf extracts.

  2. Antioxidant activity and phenol content of extracts of bark, stems, and young and mature leaves from Blepharocalyx salicifolius (Kunth O. Berg

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    E. Habermann

    Full Text Available Abstract Phenolic compounds are a group of plant secondary metabolites known to have a variety of bioactivities, including the ability to function as antioxidants. Because of the side effects of the use of synthetic substances, the search for natural and less toxic compounds has increased significantly. This study was designed to evaluate the antioxidant activity and phenol content of hexane, ethyl acetate, and aqueous extracts of the bark (suber and stems as well as the young and mature leaves of Blepharocalyx salicifolius. The extracts were obtained by extraction with organic solvents and subsequent fractionation by chromatographic partition coefficient. Preliminary tests for the presence of antioxidants were performed using bioautography in thin-layer chromatography. The antioxidant activity of the extracts was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH method, and the phenol content of the extracts was quantified using the Folin-Ciocalteu technique. The results showed that 9 of the 12 extracts evaluated displayed very strong antioxidant activity and three displayed moderate activity. Aqueous extracts of the young leaves and bark and the ethyl acetate extract of the young leaves showed the highest levels of antioxidant activity and total phenolic content (TPC. A correlation was observed between TPC and antioxidant activity index (AAI with a correlation coefficient (r2 of 0.7999. Thus, the high phenol content of B. salicifolius extracts and its correlation with antioxidant activity provide substrates for further studies.

  3. Carbon partitioning and export from mature cotton leaves

    International Nuclear Information System (INIS)

    Hendrix, D.L.; Grange, R.I.

    1991-01-01

    The partitioning of carbon in intact, mature cotton (Gossypium hirsutum L.) leaves was examined by steady-state 14 CO 2 labeling. Plants were exposed to dark periods of varying lengths, followed by similar illuminated labeling periods. These treatments produced leaves with a range of starch and soluble sugar contents, carbon exchange, and carbon export rates. Export during the illuminated periods was neither highly correlated with photosynthesis nor was export during the illuminated periods significantly different among the treatments. In contrast, the rate of subsequent nocturnal carbon export from these leaves varied widely and was found to be highly correlated with leaf starch content at the end of the illumination period and with nocturnal leaf respiration. Leaves which had accumulated the highest levels of starch (about 275 micrograms per square centimeter) by the end of the illumination period exhibited nocturnal export rates very similar to those during the daylight hours. Leaves which accumulated starch to only 50 to 75 micrograms per square centimeter virtually ceased nocturnal carbon export. For leaves with starch accumulations of between 50 and 275 micrograms per square centimeter, nocturnal export was directly proportional to leaf starch at the end of the illumination period. After the nocturnal export rate was established, it continued at a constant rate throughout the night even though leaf starch and sucrose contents declined

  4. Carbon partitioning and export from mature cotton leaves.

    Science.gov (United States)

    Hendrix, D L; Grange, R I

    1991-01-01

    The partitioning of carbon in intact, mature cotton (Gossypium hirsutum L.) leaves was examined by steady-state (14)CO(2) labeling. Plants were exposed to dark periods of varying lengths, followed by similar illuminated labeling periods. These treatments produced leaves with a range of starch and soluble sugar contents, carbon exchange, and carbon export rates. Export during the illuminated periods was neither highly correlated with photosynthesis nor was export during the illuminated periods significantly different among the treatments. In contrast, the rate of subsequent nocturnal carbon export from these leaves varied widely and was found to be highly correlated with leaf starch content at the end of the illumination period (r = 0.934) and with nocturnal leaf respiration (r = 0.954). Leaves which had accumulated the highest levels of starch (about 275 micrograms per square centimeter) by the end of the illumination period exhibited nocturnal export rates very similar to those during the daylight hours. Leaves which accumulated starch to only 50 to 75 micrograms per square centimeter virtually ceased nocturnal carbon export. For leaves with starch accumulations of between 50 and 275 micrograms per square centimeter, nocturnal export was directly proportional to leaf starch at the end of the illumination period. After the nocturnal export rate was established, it continued at a constant rate throughout the night even though leaf starch and sucrose contents declined.

  5. Pharmacognostical Studies On Leaves And Stem Of Cocculus ...

    African Journals Online (AJOL)

    The total ash values, acid insoluble ash and water soluble ash were found to be 2.20 %, 0.40 %, 0.60 % and 5.2 %,0.60 %, 1.50 % w/w for leaves and stem respectively. The loss on drying was found to be 1.21 % and 1.30 % w/w for the leaves and stem respectively. The leaf constants such as stomatal index (6.50), vein islet ...

  6. Pharmacognostic Investigation of the Leaves and Stems of ...

    African Journals Online (AJOL)

    Purpose: Some pharmacognostical investigations were carried out on the leaves and stems of Viburnum erubescens Wall.ex DC to record parameters for identifying and differentiating various species of Viburnum. Methods: The research specimens were authenticated and preserved both in fresh and dry forms. The leaves ...

  7. Comparative proteomics of leaves found at different stem positions of maize seedlings.

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    Chen, Yi-Bo; Wang, Dan; Ge, Xuan-Liang; Zhao, Biligen-Gaowa; Wang, Xu-Chu; Wang, Bai-Chen

    2016-07-01

    To better understand the roles of leaves at different stem positions during plant development, we measured the physiological properties of leaves 1-4 on maize seedling stems, and performed a proteomics study to investigate the differences in protein expression in the four leaves using two-dimensional difference gel electrophoresis and tandem mass spectrometry in conjunction with database searching. A total of 167 significantly differentially expressed protein spots were found and identified. Of these, 35% are involved in photosynthesis. By further analysis of the data, we speculated that in leaf 1 the seedling has started to transition from a heterotroph to an autotroph, development of leaf 2 is the time at which the seedling fully transitions from a heterotroph to an autotroph, and leaf maturity was reached only with fully expanded leaves 3 and 4, although there were still some protein expression differences in the two leaves. These results suggest that the different leaves make different contributions to maize seedling growth via modulation of the expression of the photosynthetic proteins. Together, these results provide insight into the roles of the different maize leaves as the plant develops from a heterotroph to an autotroph. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. THE EFFECT OF HARVESTING TIME AND DEGREE OF LEAVES MATURATION ON VITEKSIKARPIN LEVEL IN LEGUNDI LEAVES (Vitex trifolia L.

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    Yosi Bayu Murti

    2015-11-01

    Full Text Available Legundi (Vitex trifolia L. is one of Indonesia’s traditional crops that have not been studied and developed into fitofarmaka. Legundi leaves can be used for therapy in asthmatics with optimum level. Therefore it is necessary for optimization of harvesting Legundi leaves which includes time and degree of maturation of the leaves. Harvesting time optimization by means of harvesting the leaves at the different times i.e. morning, noon, and evening, while the leaf maturation level optimization by way of harvesting leaves numbered one through five of the youngest end, then the time of harvesting and leaves that provide optimum levels of viteksikarpin were assigned. Measurements of viteksikarpin assigned using TLCdensitometry then analyzed using Wincats software and Microsoft Office Excel 2007. The highest viteksikarpin levels in Legundi leaves harvested in the afternoon, then during the day, and the lowest in the morning. The highest viteksikarpin levels of Legundi leaves were on second leaf, first leaf, third leaf, fourth leaf, and the lowest on fifth leaf. Optimum levels of viteksikarpin in Legundi leaves was harvested in the afternoon by picking the first until the third leaf.

  9. Ethanol extracts of Newbouldia laevis stem and leaves modulate ...

    African Journals Online (AJOL)

    The ethanol extracts of N. laevis leaves and stem possessed antioxidant activity as shown by increased activities of superoxide dismutase and catalase, and glutathione levels of the diabetic rats after treatment. High levels of alkaline phosphatase (ALP), and alanine aminotransaminase (ALT), which are typical of oxidative ...

  10. Comparative analgesic activity of the root bark, stem bark, leaves ...

    African Journals Online (AJOL)

    The analgesic activity of the water extracts (50,100 and150 mg/Kg body weight) of the root bark, stem bark, leaves, fruits and seeds of Carissa edulis were evaluated in mice using the mechanical method (tail-chip method) and chemical method (acetic acid induced writhing). The plant was found to have analgesic activity, ...

  11. Quantitative Variation of Flavonoids and Diterpenes in Leaves and Stems of Cistus ladanifer L. at Different Ages

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    Cristina Valares Masa

    2016-02-01

    Full Text Available The compounds derived from secondary metabolism in plants perform a variety of ecological functions, providing the plant with resistance to biotic and abiotic factors. The basal levels of these metabolites for each organ, tissue or cell type depend on the development stage of the plant and they may be modified as a response to biotic and/or abiotic stress. As a consequence, the resistance state of a plant may vary in space and time. The secondary metabolites of Cistus ladanifer have been quantified in leaves and stems throughout autumn, winter, spring and summer, and at different ages of the plant. This study shows that there are significant differences between young leaves, mature leaves and stems, and between individuals of different ages. Young leaves show significantly greater synthesis of flavonoids and diterpenes than mature leaves and stems, with a clear seasonal variation, and the differences between leaves at different growth stages and stems is maintained during the quantified seasons. With respect to age, specimens under one year of age secreted significantly lower amounts of compounds. The variation in the composition of secondary metabolites between different parts of the plant, the season and the variations in age may determine the interactions of Cistus ladanifer with the biotic and abiotic factors to which it is exposed.

  12. Changes in photosynthetic performance and antioxidative strategies during maturation of Norway maple (Acer platanoides L.) leaves.

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    Lepeduš, Hrvoje; Gaća, Vlatka; Viljevac, Marija; Kovač, Spomenka; Fulgosi, Hrvoje; Simić, Domagoj; Jurković, Vlatka; Cesar, Vera

    2011-04-01

    Different structural and functional changes take place during leaf development. Since some of them are highly connected to oxidative metabolism, regulation of reactive oxygen species (ROS) abundance is required. Most of the reactive oxygen species ROS in plant cells are produced in chloroplasts as a result of highly energetic reactions of photosynthesis. The aim of our study was to examine the changes in concentration of oxidative stress parameters (TBARS - thiobarbituric acid-reacting substances and protein carbonyls) as well as antioxidative strategies during development of maple (Acer platanoides L.) leaves in the light of their enhanced photosynthetic performance. We reveal that biogenesis of the photosynthetic apparatus during maple leaf maturation corresponded with oxidative damage of lipids, but not proteins. In addition, antioxidative responses in young leaves differed from that in older leaves. Young leaves had high values of non-photochemical quenching (NPQ) and catalase (CAT, EC 1.11.1.6) activity which declined during the maturation process. Developing leaves were characterized by an increase in TBARS level, the content of non-enzymatic antioxidants as well as ascorbate peroxidase activity (APX, EC 1.11.1.11), while the content of protein carbonyls decreased with leaf maturation. Fully developed leaves had the highest lipid peroxidation level accompanied by a maximum in ascorbic acid content and superoxide dismutase activity (SOD, EC1.15.1.1). These observations imply completely different antioxidative strategies during leaf maturation enabling them to perform their basic function. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  13. Induction of Biomolecules in Mature Leaves of Terminalia arjuna Due to Feeding of Antheraea mylitta Drury

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    G. Abraham

    2004-01-01

    Full Text Available Terminalia arjuna is an important food plant of the tasar silkworm, Antheraea mylitta Drury. In this study, we investigated the induction of biomolecules in mature leaves of these plants subjected to insect feeding. Increase in total tannin content, lipid peroxidation, and trypsin inhibitor activity have been observed in mature leaves damaged by the insects. The growth rate of Vth instar larvae of A. mylitta fed on previously damaged foliage reduced by 87.1%. Induction of biomolecules for defense mechanisms in relation to herbivore damage has been discussed.

  14. Plant-specific volatile organic compound emission rates from young and mature leaves of Mediterranean vegetation

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    Bracho-Nunez, Araceli; Welter, Saskia; Staudt, Michael; Kesselmeier, Jürgen

    2011-08-01

    The seasonality of vegetation, i.e., developmental stages and phenological processes, affects the emission of volatile organic compounds (VOCs). Despite the potential significance, the contributions of seasonality to VOC emission quality and quantity are not well understood and are therefore often ignored in emission simulations. We investigated the VOC emission patterns of young and mature leaves of several Mediterranean plant species in relation to their physiological and developmental changes during the growing period and estimated Es. Foliar emissions of isoprenoids and oxygenated VOCs like methanol and acetone were measured online by means of a proton transfer reaction mass spectrometer (PTR-MS) and offline with gas chromatography coupled with a mass spectrometer and flame ionization detector. The results suggest that VOC emission is a developmentally regulated process and that quantitative and qualitative variability is plant species specific. Leaf ontogeny clearly influenced both the VOC Es and the relative importance of different VOCs. Methanol was the major compound contributing to the sum of target VOC emissions in young leaves (11.8 ± 10.4 μg g-1 h-1), while its contribution was minor in mature leaves (4.1 ± 4.1 μg g-1 h-1). Several plant species showed a decrease or complete subsidence of monoterpene, sesquiterpene, and acetone emissions upon maturity, perhaps indicating a potential response to the higher defense demands of young emerging leaves.

  15. Catalase activity is modulated by calcium and calmodulin in detached mature leaves of sweet potato.

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    Afiyanti, Mufidah; Chen, Hsien-Jung

    2014-01-15

    Catalase (CAT) functions as one of the key enzymes in the scavenging of reactive oxygen species and affects the H2O2 homeostasis in plants. In sweet potato, a major catalase isoform was detected, and total catalase activity showed the highest level in mature leaves (L3) compared to immature (L1) and completely yellow, senescent leaves (L5). The major catalase isoform as well as total enzymatic activity were strongly suppressed by ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). This inhibition could be specifically and significantly mitigated in mature L3 leaves by exogenous CaCl2, but not MgCl2 or CoCl2. EGTA also inhibited the activity of the catalase isoform in vitro. Furthermore, chlorpromazine (CPZ), a calmodulin (CAM) inhibitor, drastically suppressed the major catalase isoform as well as total enzymatic activity, and this suppression was alleviated by exogenous sweet potato calmodulin (SPCAM) fusion protein in L3 leaves. CPZ also inhibited the activity of the catalase isoform in vitro. Protein blot hybridization showed that both anti-catalase SPCAT1 and anti-calmodulin SPCAM antibodies detect a band at the same position, which corresponds to the activity of the major catalase isoform from unboiled, but not boiled crude protein extract of L3 leaves. An inverse correlation between the major catalase isoform/total enzymatic activity and the H2O2 level was also observed. These data suggest that sweet potato CAT activity is modulated by CaCl2 and SPCAM, and plays an important role in H2O2 homeostasis in mature leaves. Association of SPCAM with the major CAT isoform is required and regulates the in-gel CAT activity band. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. A Proteomics Sample Preparation Method for Mature, Recalcitrant Leaves of Perennial Plants

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    Na, Zhang; Chengying, Lao; Bo, Wang; Dingxiang, Peng; Lijun, Liu

    2014-01-01

    Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie). An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants. PMID:25028960

  17. A proteomics sample preparation method for mature, recalcitrant leaves of perennial plants.

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    Deng Gang

    Full Text Available Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie. An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.

  18. [Research on quality changes in ginseng stems and leaves before and after frost].

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    Zhao, Yan; Ma, Shuang; Cai, En-Bo; Liu, Shuang-Li; Yang, He; Zhang, Lian-Xue; Wang, Shi-Jie

    2014-08-01

    The present study is to investigate the quality changes of ginseng stems and leaves before and after frost. The contents changes of ginsenoside, free amino acid, and total phenolic compounds, as well as DPPH radical scavenging effect before and after frost were measured. The content of 9 ginsenoside monomer in ginseng stems was decreased except for Rg, and Re after frost, but in ginseng leaves was all decreased. The total content of amino acids was decreased in ginseng stems after frost, while increased in ginseng leaves. The content of phenolic compounds in ginseng stems and leaves were both decreased after frost while the ability of DPPH radical scavenging was improved. The factor of frost has great impact on the quality of ginseng stems and leaves.

  19. Generation, characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells.

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    Zhang, Zhenzhen; Liu, Jianfang; Liu, Yang; Li, Zheng; Gao, Wei-Qiang; He, Zuping

    2013-02-01

    Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end-stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end-stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra-hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra-hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. Copyright © 2012 Wiley Periodicals, Inc.

  20. Factors affecting levels of some phenolic compounds, digestibility, and nitrogen content of the mature leaves ofBarteria fistulosa (Passifloraceae).

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    Waterman, P G; Ross, J A; McKey, D B

    1984-03-01

    Levels of total phenolics, condensed tannins, acid detergent fiber, pepsin/cellulase digestibility, and nitrogen in mature leaves of 26 individuals of the ant-plant,Barteria fistulosa, have been determined. Analysis of the results in terms of the presence or absence of ants and the position of the branch from which the leaves were collected showed no relationship with concentrations of phenolics or fiber and only a weak relationship with digestibility and nitrogen. By contrast, light intensity strongly influenced levels of phenolics, notably condensed tannins, so that mature leaves of individuals growing in direct sunlight were less digestible and appeared to be of lower quality as food for herbivores than did mature leaves of individuals in shaded positions. Possible reasons for the variation in condensed tannin levels are discussed.

  1. Antioxidant Activity, Colour and Mineral Content Of Herbal Tea Prepared From Cosmos Caudatus Leaves at Different Maturity Stages

    International Nuclear Information System (INIS)

    Dian Nashiela Fatanah; Noriham Abdullah; Nooraain Hashim; Azizah Abd Hamid

    2016-01-01

    In recent years, increasing consumption of herbal tea is a worldwide trend because of their refreshing taste, positive potential health effect, convenience, abundant resources and also cheaper in price. However, different maturity stages of plants being used as raw material could affect the antioxidant activity, colour and mineral content in herbal tea. Thus, this present study was aimed at determining antioxidant activity, colour and mineral content of herbal tea prepared from Cosmos caudatus (C. caudatus) leaves at three different maturity stages namely young, mature and old. All prepared herbal tea were analysed for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, colour and mineral content. The results demonstrated that herbal tea prepared from young leaves had strong (p<0.05) antioxidant activity compared to mature and old leaves for all assays tested. Pearsons correlation coefficient also revealed that TPC and TFC exhibited a strong positive correlation with reducing power but negatively correlated with DPPH scavenging activity indicating that these compounds are major contributors to the antioxidant activity. In fact, the darker (p<0.05) colour of C. caudatus herbal tea prepared from young leaves relates to their higher antioxidant activity as compared to mature and old leaves. However, C. caudatus herbal tea prepared from old leaves showed significantly higher in mineral content compared to mature and young leaves. Hence, it can be concluded that, as maturity increased, antioxidant activity and colour in C. caudatus herbal tea decreased and vice-versa for mineral content. (author)

  2. Age Maturity of Female Japanese Quails Fed Diets Containing Katuk Leave Meal (Sauropus androgynus L.Merr.

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    R Wiradimadja

    2007-05-01

    Full Text Available This experiment was conducted to study the effects of katuk leave meal on sexual maturity in Japanese quail. Three hundred female Japanese quails, with 4 weeks age, were assigned into a completely randomized design with 4 treatments i.e., R1 (diet with neither katuk leave meal nor cholesterin, R2 (diet without katuk leave meal + 0.10% cholesterin, R3 (diet with 15% katuk leave meal without cholesterin, and R4 (diet with 15% katuk leave meal + 0.10% cholesterin. The parameters measured were estradiol hormone in plasma, and age maturity (five percent henday production. Estradiol hormone was measured with Radioimmunoassay. The data were collected and analyzed by using completely randomized design. The results showed that the addition of 15% katuk leave meal in the diet significantly decreased the estrogen concentration (P<0.05, so that slow down on the age maturity of female Japanese quail. (Animal Production 9(2: 67-72 (2007Key Words : Katuk leave meal, estradiol hormone, age maturity, quail

  3. Antioxidant activity and total phenolic content of Moringa oleifera leaves in two stages of maturity.

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    Sreelatha, S; Padma, P R

    2009-12-01

    Antioxidants play an important role in inhibiting and scavenging free radicals, thus providing protection to human against infections and degenerative diseases. Current research is now directed towards natural antioxidants originated from plants due to safe therapeutics. Moringa oleifera is used in Indian traditional medicine for a wide range of various ailments. To understand the mechanism of pharmacological actions, antioxidant properties of the Moringa oleifera leaf extracts were tested in two stages of maturity using standard in vitro models. The successive aqueous extract of Moringa oleifera exhibited strong scavenging effect on 2, 2-diphenyl-2-picryl hydrazyl (DPPH) free radical, superoxide, nitric oxide radical and inhibition of lipid per oxidation. The free radical scavenging effect of Moringa oleifera leaf extract was comparable with that of the reference antioxidants. The data obtained in the present study suggests that the extracts of Moringa oleifera both mature and tender leaves have potent antioxidant activity against free radicals, prevent oxidative damage to major biomolecules and afford significant protection against oxidative damage.

  4. Mature lymphoid malignancies: origin, stem cells, and chronicity

    DEFF Research Database (Denmark)

    Husby, Simon; Grønbæk, Kirsten

    2017-01-01

    after treatment. Lately, the use of next-generation sequencing techniques has revealed essential information on the clonal evolution of lymphoid malignancies. Also, experimental xenograft transplantation point to the possible existence of an ancestral (stem) cell. Such a malignant lymphoid stem cell...... population could potentially evade current therapies and be the cause of chronicity and death in lymphoma patients; however, the evidence is divergent across disease entities and between studies. In this review we present an overview of genetic studies, case reports, and experimental evidence of the source...

  5. Solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation: piece by piece.

    Science.gov (United States)

    Lundy, David J; Lee, Desy S; Hsieh, Patrick C H

    2017-03-01

    There is a growing need for in vitro models which can serve as platforms for drug screening and basic research. Human adult cardiomyocytes cannot be readily obtained or cultured, and so pluripotent stem cell-derived cardiomyocytes appear to be an attractive option. Unfortunately, these cells are structurally and functionally immature-more comparable to foetal cardiomyocytes than adult. A recent study by Ruan et al ., provides new insights into accelerating the maturation process and takes us a step closer to solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation.

  6. Mature adipocytes may be a source of stem cells for tissue engineering

    International Nuclear Information System (INIS)

    Fernyhough, M.E.; Hausman, G.J.; Guan, L.L.; Okine, E.; Moore, S.S.; Dodson, M.V.

    2008-01-01

    Adipose tissue contains a large portion of stem cells. These cells appear morphologically like fibroblasts and are primarily derived from the stromal cell fraction. Mature (lipid-filled) adipocytes possess the ability to become proliferative cells and have been shown to produce progeny cells that possess the same morphological (fibroblast-like) appearance as the stem cells from the stromal fraction. A closer examination of mature adipocyte-derived progeny cells may prove to be an emerging area of growth/metabolic physiology that may modify present thinking about adipose tissue renewal capabilities. Knowledge of these cells may also prove beneficial in cell-based therapies for tissue repair, regeneration, or engineering

  7. Anatomical alterations of Phaseolus vulgaris L. mature leaves irradiated with X-rays.

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    De Micco, V; Arena, C; Aronne, G

    2014-01-01

    The cultivation of higher plants in Space involves not only the development of new agro-technologies for the design of ecologically closed Space greenhouses, but also understanding of the effects of Space factors on biological systems. Among Space factors, ionising radiation is one of the main constraints to the growth of organisms. In this paper, we analyse the effect of low-LET radiation on leaf histology and cytology in Phaseolus vulgaris L. plants subjected to increasing doses of X-rays (0.3, 10, 50, 100 Gy). Leaves irradiated at tissue maturity were compared with not-irradiated controls. Semi-thin sections of leaves were analysed through light and epi-fluorescence microscopy. Digital image analysis was applied to quantify anatomical parameters, with a specific focus on the occurrence of signs of structural damage as well as alterations at subcellular level, such as the accumulation of phenolic compounds and chloroplast size. Results showed that even at high levels of radiation, general anatomical structure was not severely perturbed. Slight changes in mesophyll density and cell enlargement were detected at the highest level of radiation. However, at 100 Gy, higher levels of phenolic compounds accumulated along chloroplast membranes: this accompanied an increase in number of chloroplasts. The reduced content of chlorophylls at high levels of radiation was associated with reduced size of the chloroplasts. All data are discussed in terms of the possible role of cellular modifications in the maintenance of high radioresistance and photosynthetic efficiency. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Mechanosensitivity of dental pulp stem cells is related to their osteogenic maturity.

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    Kraft, David C E; Bindslev, Dorthe A; Melsen, Birte; Abdallah, Basem M; Kassem, Moustapha; Klein-Nulend, Jenneke

    2010-02-01

    For engineering bone tissue, mechanosensitive cells are needed for bone (re)modelling. Local bone mass and architecture are affected by mechanical loading, which provokes a cellular response via loading-induced interstitial fluid flow. We studied whether human dental pulp-derived mesenchymal stem cells (PDSCs) portraying mature (PDSC-mature) or immature (PDSC-immature) bone cell characteristics are responsive to pulsating fluid flow (PFF) in vitro. We also assessed bone formation by PDSCs on hydroxyapatite-tricalcium phosphate granules after subcutaneous implantation in mice. Cultured PDSC-mature exhibited higher osteocalcin and alkaline phosphatase gene expression and activity than PDSC-immature. Pulsating fluid flow (PFF) stimulated nitric oxide production within 5 min by PDSC-mature but not by PDSC-immature. In PDSC-mature, PFF induced prostaglandin E(2) production, and cyclooxygenase 2 gene expression was higher than in PDSC-immature. Implantation of PDSC-mature resulted in more osteoid deposition and lamellar bone formation than PDSC-immature. We conclude that PDSCs with a mature osteogenic phenotype are more responsive to pulsating fluid shear stress than osteogenically immature PDSCs and produce more bone in vivo. These data suggest that PDSCs with a mature osteogenic phenotype might be preferable for bone tissue engineering to restore, for example, maxillofacial defects, because they might be able to perform mature bone cell-specific functions during bone adaptation to mechanical loading in vivo.

  9. Antifungal and antioxidant activities of mature leaves of Myrcia splendens (Sw. DC.

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    F. C. Pontes

    2018-05-01

    Full Text Available Abstract In recent years, natural products with antifungal and antioxidant activities are being increasingly researched for a more sustainable alternative to the chemicals currently used for the same purpose. The plant pathogenic fungus Alternaria alternata is a causative agent of diseases in citrus, leading to huge economic losses. Antioxidants are important for the production of medicines for various diseases that may be related to the presence of free radicals, such as cancer, and in the cosmetic industry as an anti-aging agent and the food industry as preservatives. This study evaluated the antifungal and antioxidant potential of extracts of mature leaves of Myrcia splendens, a tree species that occurs in the Brazilian Cerrado. The antioxidant potential was analyzed by an assay of 1,1-diphenyl-2-picrylhydrazyl radical-scavenging method, and the antifungal activity was assessed through the evaluation of mycelial growth. Majority of the extracts exhibited a strong antioxidant activity, especially the acetonic extract (4A. The antioxidant activity may be related to the presence of phenolic compounds. However, the extracts showed no inhibitory activity of mycelial growth of the fungus tested, with the exception of dichloromethanic extract (2B, which had an inhibitory effect (10.2% at the end of testing.

  10. Cord blood mesenchymal stem cells propel human dendritic cells to an intermediate maturation state and boost interleukin-12 production by mature dendritic cells.

    NARCIS (Netherlands)

    Berk, L.C.J. van den; Roelofs, H.; Huijs, T.; Siebers-Vermeulen, K.G.C.; Raymakers, R.A.P.; Kogler, G.; Figdor, C.G.; Torensma, R.

    2009-01-01

    Pathogen-derived entities force the tissue-resident dendritic cells (DCs) towards a mature state, followed by migration to the draining lymph node to present antigens to T cells. Bone marrow mesenchymal stem cells (MSCs) modulate the differentiation, maturation and function of DCs. In umbilical cord

  11. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    K. Al-Mughrabi

    2003-12-01

    Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

  12. Induction of embryogenic callus and plantlet regeneration from young leaves of high yielding mature oil palm

    Directory of Open Access Journals (Sweden)

    Yeedum, I.

    2004-09-01

    Full Text Available Callus induction and plantlet regeneration from young leaves of high-yielding mature oil palm were carried out using 10-year and 20-year-old trees from Thepa Research Station, Faculty of Natural Resources,Prince of Songkla University, Hat Yai, and Trang Agricultural College, respectively. Culture media used in this experiment were Murashige and Skoog (1962 and Oil Palm supplemented with various concentrations of α-naphthaleneacetic acid (NAA or 2,4- dichlorophenoxy acetic acid (2,4-D or dicamba (Di and antioxidants.Young leaves from 6th to 11st frond were excised, sterilized, cut into 5x5 mm pieces and cultured in the dark at 26±4ºC or 28±0.5ºC for 3 months. The results revealed that MS medium with 200 mg/l ascorbic acid (As and 1 mg/l Di (MS-AsDi gave the highest callus induction percentage (7.93 after culture for 3 months at 28±0.5ºC. Leaf segments from 6th - 8th frond yielded callus forming percentage at 10% (averaged from 1, 2.5 and 5 mg/l Di containing MS medium. Ascorbic acid as an antioxidant at concentration of 200 mg/l supplemented in MS medium in the presence of 2.5 mg/l Di produced the highest callus induction percentage (11.2 and number of nodules (7.06. A high percentage of embryogenic callus formation (66.67 was obtained when the calli were transferred to the same medium component supplemented with 0.5 mg/l Di and 1,000 mg/l casein hydrolysate (CH (MS-AsDiCH. Haustorial-staged embryos were observed to be isolated as an individual embryo and germinated on MS medium without plant growth regulator (MS-free. Development of root could be classified into two distinct types, fibrous and tap root.

  13. Investigating and modeling the pyrolysis kinetic of leaves and stems of pistachio trees for biofuel production

    Directory of Open Access Journals (Sweden)

    M Ostad Hoseini

    2016-09-01

    Full Text Available Introduction The lignocelluloses materials have high potential for producing various types of biofuels. These materials include various parts of plants, especially leaves and stems that are left without a specific usage after annual pruning. These residues can be used through slow or fast pyrolysis process for production of liquid and gaseous biofuels. The slow pyrolysis is taking place at temperatures below 500°C while fast pyrolysis process takes place at a temperature above 700°C. Various studies on production of biofuels from plant residues have shown that the temperature, heating rate and the resident time of pyrolysis process are the main factors that affect the final product quality. At present time, in Iran, there are more than 360 thousands hectares of pistachio growing fields which annually produce over 215 thousands metric tons residues which are mainly leaves and stems. The main objective of this study was to measure the heating properties of the powders prepared from the leaves and the stem of pistachio trees. These properties include higher heating value (HHV, lower heating value (LHV and thermal gravimetric analysis (TGA of the powders. Then the powders were separately pyrolysed and the kinetic of the pyrolysis process for producing charcoal from them was investigated. Materials and Methods In this research, leaves and stems of pistachio trees were initially analyzed to determine their chemical constituents including moisture content, volatile compounds, carbon (C, hydrogen (H, nitrogen (N, sulfur (S and oxygen (O content. Using these constituents the height heating value and low heating value for the leaves and the stems were determined. The thermal gravimetric analysis (TGA of the powders was made to select a proper heating temperature for pyrolysis of the powders. In each experiment about 10 g of powder powders were pyrolyzed to produce char. Based on TGA results, the pyrolysis experiments were performed at 350, 400, 450 and

  14. Engineering adolescence: maturation of human pluripotent stem cell-derived cardiomyocytes.

    Science.gov (United States)

    Yang, Xiulan; Pabon, Lil; Murry, Charles E

    2014-01-31

    The discovery of human pluripotent stem cells (hPSCs), including both human embryonic stem cells and human-induced pluripotent stem cells, has opened up novel paths for a wide range of scientific studies. The capability to direct the differentiation of hPSCs into functional cardiomyocytes has provided a platform for regenerative medicine, development, tissue engineering, disease modeling, and drug toxicity testing. Despite exciting progress, achieving the optimal benefits has been hampered by the immature nature of these cardiomyocytes. Cardiac maturation has long been studied in vivo using animal models; however, finding ways to mature hPSC cardiomyocytes is only in its initial stages. In this review, we discuss progress in promoting the maturation of the hPSC cardiomyocytes, in the context of our current knowledge of developmental cardiac maturation and in relation to in vitro model systems such as rodent ventricular myocytes. Promising approaches that have begun to be examined in hPSC cardiomyocytes include long-term culturing, 3-dimensional tissue engineering, mechanical loading, electric stimulation, modulation of substrate stiffness, and treatment with neurohormonal factors. Future studies will benefit from the combinatorial use of different approaches that more closely mimic nature's diverse cues, which may result in broader changes in structure, function, and therapeutic applicability.

  15. Sex Differences in Maturation of Human Embryonic Stem Cell-Derived β Cells in Mice.

    Science.gov (United States)

    Saber, Nelly; Bruin, Jennifer E; O'Dwyer, Shannon; Schuster, Hellen; Rezania, Alireza; Kieffer, Timothy J

    2018-04-01

    Pancreatic progenitors derived from human embryonic stem cells (hESCs) are now in clinical trials for insulin replacement in patients with type 1 diabetes. Animal studies indicate that pancreatic progenitor cells can mature into a mixed population of endocrine cells, including glucose-responsive β cells several months after implantion. However, it remains unclear how conditions in the recipient may influence the maturation and ultimately the function of these hESC-derived cells. Here, we investigated the effects of (1) pregnancy on the maturation of human stage 4 (S4) pancreatic progenitor cells and (2) the impact of host sex on both S4 cells and more mature stage 7 (S7) pancreatic endocrine cells implanted under the kidney capsule of immunodeficient SCID-beige mice. Pregnancy led to increased proliferation of endogenous pancreatic β cells, but did not appear to affect proliferation or maturation of S4 cells at midgestation. Interestingly, S4 and S7 cells both acquired glucose-stimulated C-peptide secretion in females before males. Moreover, S4 cells lowered fasting blood glucose levels in females sooner than in males, whereas the responses with S7 cells were similar. These data indicate that the host sex may impact the maturation of hESC-derived cells in vivo and that this effect can be minimized by more advanced differentiation of the cells before implantation.

  16. Efficient and Cost-Effective Generation of Mature Neurons From Human Induced Pluripotent Stem Cells

    OpenAIRE

    Badja , Cherif; Maleeva , Galyna; El-Yazidi , Claire; Barruet , Emilie; Lasserre , Manon; Tropel , Philippe; Binetruy , Bernard; Bregestovski , Piotr; Magdinier , Frédérique

    2014-01-01

    The authors describe a feeder-free method of generating induced pluripotent stem cells by relying on the use of a chemically defined medium that overcomes the need for embryoid body formation and neuronal rosette isolation for neuronal precursors and terminally differentiated neuron production. This specific and efficient single-step strategy allows the production of mature neurons in 20–40 days with multiple applications, especially for modeling human pathologies.

  17. Differentiation of Spermatogonia Stem Cells into Functional Mature Neurons Characterized with Differential Gene Expression.

    Science.gov (United States)

    Bojnordi, Maryam Nazm; Azizi, Hossein; Skutella, Thomas; Movahedin, Mansoureh; Pourabdolhossein, Fereshteh; Shojaei, Amir; Hamidabadi, Hatef Ghasemi

    2017-09-01

    Transplantation of embryonic stem cells (ESCs) is a promising therapeutic approach for the treatment of neurodegenerative diseases. However, ESCs are not usable clinically due to immunological and ethical limitations. The identification of an alternative safe cell source opens novel options via autologous transplantation in neuro-regeneration circumventing these problems. Here, we examined the neurogenic capacity of embryonic stem-like cells (ES-like cells) derived from the testis using neural growth factor inducers and utilized them to generate functional mature neurons. The neuronal differentiation of ES-like cells is induced in three stages. Stage 1 is related to embryoid body (EB) formation. To induce neuroprogenitor cells, EBs were cultured in the presence of retinoic acid, N 2 supplement and fibroblast growth factor followed by culturing in a neurobasal medium containing B 27 , N 2 supplements for additional 10 days, to allow the maturation and development of neuronal progenitor cells. The neurogenic differentiation was confirmed by immunostaining for markers of mature neurons. The differentiated neurons were positive for Tuj1 and Tau1. Real-time PCR dates indicated the expression of Nestin and Neuro D (neuroprogenitor markers) in induced cells at the second stage of the differentiation protocol. The differentiated mature neurons exhibited the specific neuron markers Map2 and β-tubulin. The functional maturity of neurons was confirmed by an electrophysiological analysis of passive and active neural membrane properties. These findings indicated a differentiation capacity of ES-like cells derived from the testis to functionally mature neurons, which proposes them as a novel cell source for neuroregenerative medicine.

  18. Heme Oxygenase-1/Carbon Monoxide System and Embryonic Stem Cell Differentiation and Maturation into Cardiomyocytes

    Science.gov (United States)

    Suliman, Hagir B.; Zobi, Fabio

    2016-01-01

    Abstract Aims: The differentiation of embryonic stem (ES) cells into energetically efficient cardiomyocytes contributes to functional cardiac repair and is envisioned to ameliorate progressive degenerative cardiac diseases. Advanced cell maturation strategies are therefore needed to create abundant mature cardiomyocytes. In this study, we tested whether the redox-sensitive heme oxygenase-1/carbon monoxide (HO-1/CO) system, operating through mitochondrial biogenesis, acts as a mechanism for ES cell differentiation and cardiomyocyte maturation. Results: Manipulation of HO-1/CO to enhance mitochondrial biogenesis demonstrates a direct pathway to ES cell differentiation and maturation into beating cardiomyocytes that express adult structural markers. Targeted HO-1/CO interventions up- and downregulate specific cardiogenic transcription factors, transcription factor Gata4, homeobox protein Nkx-2.5, heart- and neural crest derivatives-expressed protein 1, and MEF2C. HO-1/CO overexpression increases cardiac gene expression for myosin regulatory light chain 2, atrial isoform, MLC2v, ANP, MHC-β, and sarcomere α-actinin and the major mitochondrial fusion regulators, mitofusin 2 and MICOS complex subunit Mic60. This promotes structural mitochondrial network expansion and maturation, thereby supporting energy provision for beating embryoid bodies. These effects are prevented by silencing HO-1 and by mitochondrial reactive oxygen species scavenging, while disruption of mitochondrial biogenesis and mitochondrial DNA depletion by loss of mitochondrial transcription factor A compromise infrastructure. This leads to failure of cardiomyocyte differentiation and maturation and contractile dysfunction. Innovation: The capacity to augment cardiomyogenesis via a defined mitochondrial pathway has unique therapeutic potential for targeting ES cell maturation in cardiac disease. Conclusion: Our findings establish the HO-1/CO system and redox regulation of mitochondrial biogenesis as

  19. Generation of mature T cells from human hematopoietic stem and progenitor cells in artificial thymic organoids.

    Science.gov (United States)

    Seet, Christopher S; He, Chongbin; Bethune, Michael T; Li, Suwen; Chick, Brent; Gschweng, Eric H; Zhu, Yuhua; Kim, Kenneth; Kohn, Donald B; Baltimore, David; Crooks, Gay M; Montel-Hagen, Amélie

    2017-05-01

    Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3 + TCR-αβ + single-positive CD8 + or CD4 + cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naive phenotypes, a diverse T cell receptor (TCR) repertoire and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen-specific cytotoxicity and near-complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ-encoding loci. ATOs provide a robust tool for studying human T cell differentiation and for the future development of stem-cell-based engineered T cell therapies.

  20. Stem water storage in five coexisting temperate broad-leaved tree species: significance, temporal dynamics and dependence on tree functional traits.

    Science.gov (United States)

    Köcher, Paul; Horna, Viviana; Leuschner, Christoph

    2013-08-01

    The functional role of internal water storage is increasingly well understood in tropical trees and conifers, while temperate broad-leaved trees have only rarely been studied. We examined the magnitude and dynamics of the use of stem water reserves for transpiration in five coexisting temperate broad-leaved trees with largely different morphology and physiology (genera Fagus, Fraxinus, Tilia, Carpinus and Acer). We expected that differences in water storage patterns would mostly reflect species differences in wood anatomy (ring vs. diffuse-porous) and wood density. Sap flux density was recorded synchronously at five positions along the root-to-branch flow path of mature trees (roots, three stem positions and branches) with high temporal resolution (2 min) and related to stem radius changes recorded with electronic point dendrometers. The daily amount of stored stem water withdrawn for transpiration was estimated by comparing the integrated flow at stem base and stem top. The temporal coincidence of flows at different positions and apparent time lags were examined by cross-correlation analysis. Our results confirm that internal water stores play an important role in the four diffuse-porous species with estimated 5-12 kg day(-1) being withdrawn on average in 25-28 m tall trees representing 10-22% of daily transpiration; in contrast, only 0.5-2.0 kg day(-1) was withdrawn in ring-porous Fraxinus. Wood density had a large influence on storage; sapwood area (diffuse- vs. ring-porous) may be another influential factor but its effect was not significant. Across the five species, the length of the time lag in flow at stem top and stem base was positively related to the size of stem storage. The stem stores were mostly exhausted when the soil matrix potential dropped below -0.1 MPa and daily mean vapor pressure deficit exceeded 3-5 hPa. We conclude that stem storage is an important factor improving the water balance of diffuse-porous temperate broad-leaved trees in moist

  1. Cuticle ultrastructure, cuticular lipid composition, and gene expression in hypoxia-stressed Arabidopsis stems and leaves.

    Science.gov (United States)

    Kim, Hyojin; Choi, Dongsu; Suh, Mi Chung

    2017-06-01

    An increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis and may allow plants to cope with oxygen deficiency. The hydrophobic cuticle layer consisting of cutin polyester and cuticular wax is the first barrier to protect the aerial parts of land plants from environmental stresses. In the present study, we investigated the role of cuticle membrane in Arabidopsis responses to oxygen deficiency. TEM analysis showed that the epidermal cells of hypoxia-treated Arabidopsis stems and leaves possessed a thinner electron-translucent cuticle proper and a more electron-dense cuticular layer. A reduction in epicuticular wax crystal deposition was observed in SEM images of hypoxia-treated Arabidopsis stem compared with normoxic control. Cuticular transpiration was more rapid in hypoxia-stressed leaves than in normoxic control. Total wax and cutin loads decreased by approximately 6-12 and 12-22%, respectively, and the levels of C29 alkanes, secondary alcohols, and ketones, C16:0 ω-hydroxy fatty acids, and C18:2 dicarboxylic acids were also prominently reduced in hypoxia-stressed Arabidopsis leaves and/or stems relative to normoxic control. Genome-wide transcriptome and quantitative RT-PCR analyses revealed that the expression of several genes involved in the biosynthesis and transport of cuticular waxes and cutin monomers were downregulated more than fourfold, but no significant alterations were detected in the transcript levels of fatty acid biosynthetic genes, BCCP2, PDH-E1α, and ENR1 in hypoxia-treated Arabidopsis stems and leaves compared with normoxic control. Taken together, an increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis. The present study elucidates one of the cuticle-related adaptive responses that may allow plants to cope with low oxygen levels.

  2. Effects of mesenchymal stem cells from human induced pluripotent stem cells on differentiation, maturation, and function of dendritic cells.

    Science.gov (United States)

    Gao, Wen-Xiang; Sun, Yue-Qi; Shi, Jianbo; Li, Cheng-Lin; Fang, Shu-Bin; Wang, Dan; Deng, Xue-Quan; Wen, Weiping; Fu, Qing-Ling

    2017-03-02

    Mesenchymal stem cells (MSCs) have potent immunomodulatory effects on multiple immune cells and have great potential in treating immune disorders. Induced pluripotent stem cells (iPSCs) serve as an unlimited and noninvasive source of MSCs, and iPSC-MSCs have been reported to have more advantages and exhibit immunomodulation on T lymphocytes and natural killer cells. However, the effects of iPSC-MSCs on dendritic cells (DCs) are unclear. The aim of this study is to investigate the effects of iPSC-MSCs on the differentiation, maturation, and function of DCs. Human monocyte-derived DCs were induced and cultured in the presence or absence of iPSC-MSCs. Flow cytometry was used to analyze the phenotype and functions of DCs, and enzyme-linked immunosorbent assay (ELISA) was used to study cytokine production. In this study, we successfully induced MSCs from different clones of human iPSCs. iPSC-MSCs exhibited a higher proliferation rate with less cell senescence than BM-MSCs. iPSC-MSCs inhibited the differentiation of human monocyte-derived DCs by both producing interleukin (IL)-10 and direct cell contact. Furthermore, iPSC-MSCs did not affect immature DCs to become mature DCs, but modulated their functional properties by increasing their phagocytic ability and inhibiting their ability to stimulate proliferation of lymphocytes. More importantly, iPSC-MSCs induced the generation of IL-10-producing regulatory DCs in the process of maturation, which was mostly mediated by a cell-cell contact mechanism. Our results indicate an important role for iPSC-MSCs in the modulation of DC differentiation and function, supporting the clinical application of iPSC-MSCs in DC-mediated immune diseases.

  3. Investigation of the profile of phenolic compounds in the leaves and stems of Pandiaka heudelotii using gas chromatography coupled with flame ionization detector.

    Science.gov (United States)

    Ifeanacho, Mercy O; Ikewuchi, Catherine C; Ikewuchi, Jude C

    2017-05-01

    The profile of phenolic compounds in the leaves and stems of Pandiaka heudelotii was investigated using gas chromatography coupled with flame ionization detector. The leaves and stems had high flavonoids and benzoic acid derivatives content, and moderate levels of lignans and hydroxycinnamates. Twenty-eight known flavonoids were detected, which consisted mainly of kaempferol (41.93% in leaves and 47.97% in stems), (+)-catechin (17.12% in leaves and 16.11% in stems), quercetin (13.83% in leaves and 9.39% in stems), luteolin (7.34% in leaves and 7.71% in stems), and artemetin (6.53% in leaves and 4.83% in stems). Of the six known hydroxycinnamates detected, chlorogenic acid (80.79% in leaves and 87.56% in stems) and caffeic acid (18.98% in leaves and 12.30% in stems) were the most abundant, while arctigenin (77.81% in leaves and 83.40% in stems) and retusin (13.82% in leaves and 10.59% in stems) were the most abundant of the nine known lignans detected. Twelve known benzoic acid derivatives were detected, consisting mainly of ellagic acid (65.44% in leaves and 72.89% in stems), p-hydroxybenzoic acid (25.10% in leaves and 18.95% in stems), and vanillic acid (8.80% in leaves and 7.30% in stems). The rich phytochemical profile of the leaves and stems is an indication of their ability to serve as sources of nutraceuticals.

  4. Graphene Sheet-Induced Global Maturation of Cardiomyocytes Derived from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Wang, Jiaxian; Cui, Chang; Nan, Haiyan; Yu, Yuanfang; Xiao, Yini; Poon, Ellen; Yang, Gang; Wang, Xijie; Wang, Chenchen; Li, Lingsong; Boheler, Kenneth Richard; Ma, Xu; Cheng, Xin; Ni, Zhenhua; Chen, Minglong

    2017-08-09

    Human induced pluripotent stem cells (hiPSCs) can proliferate infinitely. Their ability to differentiate into cardiomyocytes provides abundant sources for disease modeling, drug screening and regenerative medicine. However, hiPSC-derived cardiomyocytes (hiPSC-CMs) display a low degree of maturation and fetal-like properties. Current in vitro differentiation methods do not mimic the structural, mechanical, or physiological properties of the cardiogenesis niche. Recently, we present an efficient cardiac maturation platform that combines hiPSCs monolayer cardiac differentiation with graphene substrate, which is a biocompatible and superconductive material. The hiPSCs lines were successfully maintained on the graphene sheets and were able to differentiate into functional cardiomyocytes. This strategy markedly increased the myofibril ultrastructural organization, elevated the conduction velocity, and enhanced both the Ca 2+ handling and electrophysiological properties in the absence of electrical stimulation. On the graphene substrate, the expression of connexin 43 increased along with the conduction velocity. Interestingly, the bone morphogenetic proteins signaling was also significantly activated during early cardiogenesis, confirmed by RNA sequencing analysis. Here, we reasoned that graphene substrate as a conductive biomimetic surface could facilitate the intrinsic electrical propagation, mimicking the microenvironment of the native heart, to further promote the global maturation of hiPSC-CMs. Our findings highlight the capability of electrically active substrates to influence cardiomyocyte development. We believe that application of graphene sheets will be useful for simple, fast, and scalable maturation of regenerated cardiomyocytes.

  5. In vitro differentiation and maturation of mouse embryonic stem cells into hepatocytes

    International Nuclear Information System (INIS)

    Ishii, Takamichi; Yasuchika, Kentaro; Fujii, Hideaki; Hoppo, Toshitaka; Baba, Shinji; Naito, Masato; Machimoto, Takafumi; Kamo, Naoko; Suemori, Hirofumi; Nakatsuji, Norio; Ikai, Iwao

    2005-01-01

    It is difficult to induce the maturation of embryonic stem (ES) cells into hepatocytes in vitro. We previously reported that Thy1-positive mesenchymal cells derived from the mouse fetal liver promote the maturation of hepatic progenitor cells. Here, we isolated alpha-fetoprotein (AFP)-producing cells from mouse ES cells for subsequent differentiation into hepatocytes in vitro by coculture with Thy1-positive cells. ES cells expressing green fluorescent protein (GFP) under the control of an AFP promoter were cultured under serum- and feeder layer-free culture conditions. The proportion of GFP-positive cells plateaued at 41.6 ± 12.2% (means ± SD) by day 7. GFP-positive cells, isolated by flow cytometry, were cultured in the presence or absence of Thy1-positive cells as a feeder layer. Isolated GFP-positive cells were stained for AFP, Foxa2, and albumin. The expression of mRNAs encoding tyrosine amino transferase, tryptophan 2,3-dioxygenase, and glucose-6-phosphatase were only detected following coculture with Thy1-positive cells. Following coculture with Thy1-positive cells, the isolated cells produced and stored glycogen. Ammonia clearance activity was also enhanced following coculture. Electron microscopic analysis indicated that the cocultured cells exhibited the morphologic features of mature hepatocytes. In conclusion, coculture with Thy1-positive cells in vitro induced the maturation of AFP-producing cells isolated from ES cell cultures into hepatocytes

  6. Paracrine Maturation and Migration of SH-SY5Y Cells by Dental Pulp Stem Cells

    OpenAIRE

    Gervois, Pascal; Wolfs, Esther; Dillen, Yörg; Hilkens, Petra; Ratajczak, Jessica; Driesen, Ronald; Vangansewinkel, Tim; Bronckaers, Annelies; Brône, Bert; Struys, Tom; Lambrichts, Ivo

    2017-01-01

    Neurological disorders are characterized by neurodegeneration and/or loss of neuronal function, which cannot be adequately repaired by the host. Therefore, there is need for novel treatment options such as cell-based therapies that aim to salvage or reconstitute the lost tissue or that stimulate host repair. The present study aimed to evaluate the paracrine effects of human dental pulp stem cells (hDPSCs) on the migration and neural maturation of human SH-SY5Y neuroblastoma cells. The hDPSC s...

  7. Why (and how) they decide to leave: A grounded theory analysis of STEM attrition at a large public research university

    Science.gov (United States)

    Minutello, Michael F.

    A grounded theory investigation of STEM attrition was conducted that describes and explains why undergraduates at a large Mid-Atlantic research university decided to leave their initial STEM majors to pursue non-STEM courses of study. Participants ultimately decided to leave their initial STEM majors because they were able to locate preferable non-STEM courses of study that did not present the same kinds of obstacles they had encountered in their original STEM majors. Grounded theory data analysis revealed participants initially enrolled in STEM majors with tenuous motivation that did not withstand the various obstacles that were present in introductory STEM coursework. Obstacles that acted as demotivating influences and prompted participants to locate alternative academic pathways include the following: (1.) disengaging curricula; (2.) competitive culture; (3.) disappointing grades; (4.) demanding time commitments; and (5.) unappealing career options. Once discouraged from continuing along their initial STEM pathways, participants then employed various strategies to discover suitable non-STEM majors that would allow them to realize their intrinsic interests and extrinsic goals. Participants were largely satisfied with their decisions to leave STEM and have achieved measures of personal satisfaction and professional success.

  8. Fungal colonization and decomposition of leaves and stems of Salix arctica on deglaciated moraines in high-Arctic Canada

    Science.gov (United States)

    Osono, Takashi; Matsuoka, Shunsuke; Hirose, Dai; Uchida, Masaki; Kanda, Hiroshi

    2014-06-01

    Fungal colonization, succession, and decomposition of leaves and stems of Salix arctica were studied to estimate the roles of fungi in the decomposition processes in the high Arctic. The samples were collected from five moraines with different periods of development since deglaciation to investigate the effects of ecosystem development on the decomposition processes during the primary succession. The total hyphal lengths and the length of darkly pigmented hyphae increased during decomposition of leaves and stems and were not varied with the moraines. Four fungal morphotaxa were frequently isolated from both leaves and stems. The frequencies of occurrence of two morphotaxa varied with the decay class of leaves and/or stems. The hyphal lengths and the frequencies of occurrence of fungal morphotaxa were positively or negatively correlated with the contents of organic chemical components and nutrients in leaves and stems, suggesting the roles of fungi in chemical changes in the field. Pure culture decomposition tests demonstrated that the fungal morphotaxa were cellulose decomposers. Our results suggest that fungi took part in the chemical changes in decomposing leaves and stems even under the harsh environment of the high Arctic.

  9. Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature

    Directory of Open Access Journals (Sweden)

    Zúñiga-Pflücker Juan

    2011-03-01

    Full Text Available Abstract Background T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully in vitro using human umbilical cord blood (UCB hematopoietic stem cells (HSCs in coculture with OP9-DL1 cells. Results HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3hi CD27hi CD1aneg and thus phenotypically resembled mature functional CD8 single positive thymocytes. These in vitro-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of Eomes and low levels of Plzf, albeit not identical to ex vivo UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, in vitro-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38, secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule. Conclusion Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.

  10. Engineered Microenvironments for the Maturation and Observation of Human Embryonic Stem Cell Derived Cardiomyocytes

    Science.gov (United States)

    Salick, Max R.

    The human heart is a dynamic system that undergoes substantial changes as it develops and adapts to the body's growing needs. To better understand the physiology of the heart, researchers have begun to produce immature heart muscle cells, or cardiomyocytes, from pluripotent stem cell sources with remarkable efficiency. These stem cell-derived cardiomyocytes hold great potential in the understanding and treatment of heart disease; however, even after prolonged culture, these cells continue to exhibit an immature phenotype, as indicated by poor sarcomere organization and calcium handling, among other features. The lack of maturation that is observed in these cardiomyocytes greatly limits their applicability towards drug screening, disease modeling, and cell therapy applications. The mechanical environment surrounding a cell has been repeatedly shown to have a large impact on that cell's behavior. For this reason, we have implemented micropatterning methods to mimic the level of alignment that occurs in the heart in vivo in order to study how this alignment may help the cells to produce a more mature sarcomere phenotype. It was discovered that the level of sarcomere organization of a cardiomyocyte can be strongly influenced by the micropattern lane geometry on which it adheres. Steps were taken to optimize this micropattern platform, and studies of protein organization, gene expression, and myofibrillogenesis were conducted. Additionally, a set of programs was developed to provide quantitative analysis of the level of sarcomere organization, as well as to assist with several other tissue engineering applications.

  11. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China’s forests

    Science.gov (United States)

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-01-01

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China’s forests using both the national forest inventory data (2004–2008) and our field measurements (2011–2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China. PMID:26525117

  12. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

    Science.gov (United States)

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-11-03

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China.

  13. Growth dynamics and cytoskeleton organization during stem maturation and gravity-induced stem bending in Zea mays L

    Science.gov (United States)

    Collings, D. A.; Winter, H.; Wyatt, S. E.; Allen, N. S.; Davies, E. (Principal Investigator)

    1998-01-01

    Characterization of gravitropic bending in the maize stem pulvinus, a tissue that functions specifically in gravity responses, demonstrates that the pulvinus is an ideal system for studying gravitropism. Gravistimulation during the second of three developmental phases of the pulvinus induces a gradient of cell elongation across the non-growing cells of the pulvinus, with the most elongation occurring on the lower side. This cell elongation is spatially and temporally separated from normal internodal cell elongation. The three characterized growth phases in the pulvinus correspond closely to a specialized developmental sequence in which structural features typical of cells not fully matured are retained while cell maturation occurs in surrounding internodal and nodal tissue. For example, the lignification of supporting tissue and rearrangement of transverse microtubules to oblique that occur in the internode when cell elongation ceases are delayed for up to 10 d in the adjacent cells of the pulvinus, and only occurs as a pulvinus loses its capacity to respond to gravistimulation. Gravistimulation does not modify this developmental sequence. Neither wall lignification nor rearrangement of transverse microtubules occurs in the rapidly elongating lower side or non-responsive upper side of the pulvinus until the pulvinus loses the capacity to bend further. Gravistimulation does, however, lead to the formation of putative pit fields within the expanding cells of the pulvinus.

  14. Paracrine Maturation and Migration of SH-SY5Y Cells by Dental Pulp Stem Cells.

    Science.gov (United States)

    Gervois, P; Wolfs, E; Dillen, Y; Hilkens, P; Ratajczak, J; Driesen, R B; Vangansewinkel, T; Bronckaers, A; Brône, B; Struys, T; Lambrichts, I

    2017-06-01

    Neurological disorders are characterized by neurodegeneration and/or loss of neuronal function, which cannot be adequately repaired by the host. Therefore, there is need for novel treatment options such as cell-based therapies that aim to salvage or reconstitute the lost tissue or that stimulate host repair. The present study aimed to evaluate the paracrine effects of human dental pulp stem cells (hDPSCs) on the migration and neural maturation of human SH-SY5Y neuroblastoma cells. The hDPSC secretome had a significant chemoattractive effect on SH-SY5Y cells as shown by a transwell assay. To evaluate neural maturation, SH-SY5Y cells were first induced toward neuronal cells, after which they were exposed to the hDPSC secretome. In addition, SH-SY5Y cells subjected to the hDPSC secretome showed increased neuritogenesis compared with nonexposed cells. Maturated cells were shown to increase immune reactivity for neuronal markers compared with controls. Ultrastructurally, retinoic acid (RA) signaling and subsequent exposure to the hDPSC secretome induced a gradual rise in metabolic activity and neuronal features such as multivesicular bodies and cytoskeletal elements associated with cellular communication. In addition, electrophysiological recordings of differentiating cells demonstrated a transition toward a neuronal electrophysiological profile based on the maximum tetrodotoxin (TTX)-sensitive, Na + current. Moreover, conditioned medium (CM)-hDPSC-maturated SH-SY5Y cells developed distinct features including, Cd 2+ -sensitive currents, which suggests that CM-hDPSC-maturated SH-SY5Y acquired voltage-gated Ca 2+ channels. The results reported in this study demonstrate the potential of hDPSCs to support differentiation and recruitment of cells with neuronal precursor characteristics in a paracrine manner. Moreover, this in vitro experimental design showed that the widely used SH-SY5Y cell line can improve and simplify the preclinical in vitro research on the molecular

  15. The fate of the dry matter, carbohydrates and 14C lost from the leaves and stems of wheat during grain filling

    International Nuclear Information System (INIS)

    Austin, R.B.; Edrich, J.A.; Ford, M.A.; Blackwell, R.D.

    1977-01-01

    In a field study with six winter wheat genotypes losses of dry matter from the stems between 30 June and maturity averaged 172 g m - 2 (range 82 to 256), there being significant differences in loss between genotypes. Respiration from the stems during the same period was estimated to amount to 106 g m -2 (range 104 to 225). The amount of dry matter mobilized from the stems, calculated by difference, was estimated as 66 g m -2 . The loss of ethanol- and water-soluble carbohydrate from the stems (170 g m -2 ; range 124 to 215) was very similar to the dry weight loss. Carbon-14 labelling was used to trace the time course and the amount of the movement of assimilates from the vegetative organs to the grain. Only 14.3 per cent (range 10.3 to 21.0) of the products of photosynthesis over the period 21 May to 20 June were relocated to the grains. This relocation amounted to an average of 7 per cent (range 5.7 to 11.4) of the final grain weight. It was estimated that during the 18 days following anthesis on 20 June photosynthesis contributed 48 per cent (range 39 to 55) of the final grain dry weight. Of this, about half was translocated to the grain within 10 days of initial assimilation. The remainder appeared to be stored temporarily in the stems and leaves and translocated to the grains during the period 17 to 29 July. In general, relocation of dry matter from the vegetative organs to the grains, assessed by carbon-14 labelling, was greatest in those genotypes (Hobbit and Sportsman) which lost most dry weight from the stems and leaves. (author)

  16. Toxicological evaluation of an aqueous suspension from leaves and stems of Petiveria alliacea L. (Phytolaccaceae).

    Science.gov (United States)

    García-Pérez, Martha-Estrella; Alfonso-Castillo, Alfredo; Lores, Onel Fong; Batista-Duharte, Alexander; Lemus-Rodríguez, Zoe

    2018-01-30

    Petiveria alliacea L. (Phytolaccaceae) is used in folk medicine due to its antispasmodic, diuretic, hypoglycemic, abortive, anti-inflammatory and anticancerogenic properties. Although P. alliacea is considered toxic by people, its toxicity remains a concern since it is strongly dependent on the extraction method and the part of the plant used during tests. Even if some healers prefer to use the aerial parts in a liquefied form or by chewing them, instead of decoctions or infusions, no toxicological studies exist using whole dried stems and leaves. The toxicity of a suspension of the powder from the leaves and stems of P. alliacea was assessed in Sprague Dawley rats by oral administration using two tests: 1) the acute toxic class method, which allows classification of substances according to their intrinsic toxicity and 2) the repeated dose 28-day method, following the guidelines 423 and 407 respectively from the Organization for the Economic Cooperation and Development. Chemical characterization of this powder was performed by GC-MS, UV-fluorescence, proximate and elemental analysis. P. alliacea powder from stems and leaves was classed in the hazard category 5 (LD 50 > 2000mg/kg) according to the acute toxicology study. There were no toxicity signs at 1000mg/kg in the repeated dose study, although higher values of total leukocytes were found in the satellite and males of the experimental group, which were attributed to the immunomodulatory properties of this plant. According to GC-MS, the prevailing compounds identified were phytol, (R)-(-)-(Z)-14-methyl-8-hexadecen-1-ol, 1-(2-hydrohyethyl)-1,2,4-triazole and methyl β-dimethylaminoisobutyrate. In conclusion, the oral administration of the P. alliacea powder to Sprague Dawley rats did not result in deaths and was not associated with adverse effects reflected in the general condition, body weights or histopathological abnormalities. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A simplified protocol for differentiation of electrophysiologically mature neuronal networks from human induced pluripotent stem cells.

    Science.gov (United States)

    Gunhanlar, N; Shpak, G; van der Kroeg, M; Gouty-Colomer, L A; Munshi, S T; Lendemeijer, B; Ghazvini, M; Dupont, C; Hoogendijk, W J G; Gribnau, J; de Vrij, F M S; Kushner, S A

    2017-04-18

    Progress in elucidating the molecular and cellular pathophysiology of neuropsychiatric disorders has been hindered by the limited availability of living human brain tissue. The emergence of induced pluripotent stem cells (iPSCs) has offered a unique alternative strategy using patient-derived functional neuronal networks. However, methods for reliably generating iPSC-derived neurons with mature electrophysiological characteristics have been difficult to develop. Here, we report a simplified differentiation protocol that yields electrophysiologically mature iPSC-derived cortical lineage neuronal networks without the need for astrocyte co-culture or specialized media. This protocol generates a consistent 60:40 ratio of neurons and astrocytes that arise from a common forebrain neural progenitor. Whole-cell patch-clamp recordings of 114 neurons derived from three independent iPSC lines confirmed their electrophysiological maturity, including resting membrane potential (-58.2±1.0 mV), capacitance (49.1±2.9 pF), action potential (AP) threshold (-50.9±0.5 mV) and AP amplitude (66.5±1.3 mV). Nearly 100% of neurons were capable of firing APs, of which 79% had sustained trains of mature APs with minimal accommodation (peak AP frequency: 11.9±0.5 Hz) and 74% exhibited spontaneous synaptic activity (amplitude, 16.03±0.82 pA; frequency, 1.09±0.17 Hz). We expect this protocol to be of broad applicability for implementing iPSC-based neuronal network models of neuropsychiatric disorders.Molecular Psychiatry advance online publication, 18 April 2017; doi:10.1038/mp.2017.56.

  18. Quantitative expression analysis of selected transcription factors in pavement, basal and trichome cells of mature leaves from Arabidopsis thaliana.

    Science.gov (United States)

    Schliep, Martin; Ebert, Berit; Simon-Rosin, Ulrike; Zoeller, Daniela; Fisahn, Joachim

    2010-05-01

    Gene expression levels of several transcription factors from Arabidopsis thaliana that were described previously to be involved in leaf development and trichome formation were analysed in trichome, basal and pavement cells of mature leaves. Single cell samples of these three cells types were collected by glass micro-capillaries. Real-time reverse transcription (RT)-PCR was used to analyse expression patterns of the following transcription factors: MYB23, MYB55, AtHB1, FILAMENTOUS FLOWER (FIL)/YABBY1 (YAB1), TRIPTYCHON (TRY) and CAPRICE (CPC). A difference in the expression patterns of TRY and CPC was revealed. Contrary to the CPC expression pattern, no transcripts of TRY could be detected in pavement cells. FIL/YAB1 was exclusively expressed in trichome cells. AtHB1 was highly expressed throughout all three cell types. MYB55 was higher expressed in basal cells than in trichome and pavement cells. MYB23 showed a pattern of low expression in pavement cells, medium in basal cells and high expression in trichomes. Expression patterns obtained by single cell sampling and real-time RT-PCR were compared to promoter GUS fusions of the selected transcription factors. Therefore, we regenerated two transgenic Arabidopsis lines that expressed the GUS reporter gene under control of the promoters of MYB55 and YAB1. In conclusion, despite their function in leaf morphogenesis, all six transcription factors were detected in mature leaves. Furthermore, single cell sampling and promoter GUS staining patterns demonstrated the predominant presence of MYB55 in basal cells as compared to pavement cells and trichomes.

  19. Alternative donor hematopoietic stem cell transplantation for mature lymphoid malignancies after reduced-intensity conditioning regimen

    DEFF Research Database (Denmark)

    Rodrigues, Celso Arrais; Rocha, Vanderson; Dreger, Peter

    2014-01-01

    We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received...... an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97......%, respectively; Pblood than after matched unrelated donor, whereas no differences were observed in grade II-IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28...

  20. Direct Induction and Functional Maturation of Forebrain GABAergic Neurons from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Alfred Xuyang Sun

    2016-08-01

    Full Text Available Gamma-aminobutyric acid (GABA-releasing interneurons play an important modulatory role in the cortex and have been implicated in multiple neurological disorders. Patient-derived interneurons could provide a foundation for studying the pathogenesis of these diseases as well as for identifying potential therapeutic targets. Here, we identified a set of genetic factors that could robustly induce human pluripotent stem cells (hPSCs into GABAergic neurons (iGNs with high efficiency. We demonstrated that the human iGNs express neurochemical markers and exhibit mature electrophysiological properties within 6–8 weeks. Furthermore, in vitro, iGNs could form functional synapses with other iGNs or with human-induced glutamatergic neurons (iENs. Upon transplantation into immunodeficient mice, human iGNs underwent synaptic maturation and integration into host neural circuits. Taken together, our rapid and highly efficient single-step protocol to generate iGNs may be useful to both mechanistic and translational studies of human interneurons.

  1. Steps toward Maturation of Embryonic Stem Cell-Derived Cardiomyocytes by Defined Physical Signals

    Directory of Open Access Journals (Sweden)

    Nian Shen

    2017-07-01

    Full Text Available Cardiovascular disease remains a leading cause of mortality and morbidity worldwide. Embryonic stem cell-derived cardiomyocytes (ESC-CMs may offer significant advances in creating in vitro cardiac tissues for disease modeling, drug testing, and elucidating developmental processes; however, the induction of ESCs to a more adult-like CM phenotype remains challenging. In this study, we developed a bioreactor system to employ pulsatile flow (1.48 mL/min, cyclic strain (5%, and extended culture time to improve the maturation of murine and human ESC-CMs. Dynamically-cultured ESC-CMs showed an increased expression of cardiac-associated proteins and genes, cardiac ion channel genes, as well as increased SERCA activity and a Raman fingerprint with the presence of maturation-associated peaks similar to primary CMs. We present a bioreactor platform that can serve as a foundation for the development of human-based cardiac in vitro models to verify drug candidates, and facilitates the study of cardiovascular development and disease.

  2. Functional Maturation of Human Stem Cell-Derived Neurons in Long-Term Cultures.

    Directory of Open Access Journals (Sweden)

    Rebecca S Lam

    Full Text Available Differentiated neurons can be rapidly acquired, within days, by inducing stem cells to express neurogenic transcription factors. We developed a protocol to maintain long-term cultures of human neurons, called iNGNs, which are obtained by inducing Neurogenin-1 and Neurogenin-2 expression in induced pluripotent stem cells. We followed the functional development of iNGNs over months and they showed many hallmark properties for neuronal maturation, including robust electrical and synaptic activity. Using iNGNs expressing a variant of channelrhodopsin-2, called CatCh, we could control iNGN activity with blue light stimulation. In combination with optogenetic tools, iNGNs offer opportunities for studies that require precise spatial and temporal resolution. iNGNs developed spontaneous network activity, and these networks had excitatory glutamatergic synapses, which we characterized with single-cell synaptic recordings. AMPA glutamatergic receptor activity was especially dominant in postsynaptic recordings, whereas NMDA glutamatergic receptor activity was absent from postsynaptic recordings but present in extrasynaptic recordings. Our results on long-term cultures of iNGNs could help in future studies elucidating mechanisms of human synaptogenesis and neurotransmission, along with the ability to scale-up the size of the cultures.

  3. Chemical composition and anti-inflammatory evaluation of essential oils from leaves and stem barks from Drimys brasiliensis Miers (Winteraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Lago, Joao Henrique G., E-mail: joao.lago@unifesp.b [Universidade Federal de Sao Paulo (UNIFESP-EPM), Diadema, SP (Brazil). Dept. de Ciencias Exatas e da Terra; Carvalho, Larissa A.C.; Silva, Flavia S. da; Romoff, Paulete [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades; Toyama, Daniela de O.; Favero, Oriana A. [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias Biologicas e da Saude

    2010-07-01

    The essential oils from leaves and stem barks from Drimys brasiliensis Miers (Winteraceae) were individually obtained by hydrodistillation and their compounds characterized by use of GC/FID and GC/MS. The main identified derivatives were monoterpenes (leaves 4.31% and stem barks 90.02%) and sesquiterpenes (leaves 52.31% and stem barks 6.35%). Additionally, the sesquiterpene polygodial was isolated from hexane extract from stem barks of D. brasiliensis after chromatographic steps and characterized by spectroscopic means, mainly NMR. Aiming the evaluation of anti-inflammatory potential, the crude essential oils and the sesquiterpene polygodial were subjected to bioassays to evaluate the acute toxicity of these compounds as well as the anti-inflammatory and antinociceptive activities induced by carrageenan and formalin in mice. Ours results showed that essential oil obtained from the stem barks significantly reduced the oedema induced by carrageenan. The anti-inflammatory effect induced by stem barks oil (at 200 mg kg{sup -1}) was similar to observed for indomethacin (at 10 mg kg{sup -1}) and superior for polygodial (at 200 mg kg{sup -1}) in 30 and 60 min after the administration of essential oils. The inflammatory response induced by formalin was effective to the stem barks oil (62.5%) in comparison to polygodial (50.0%). (author)

  4. Chemical composition and anti-inflammatory evaluation of essential oils from leaves and stem barks from Drimys brasiliensis Miers (Winteraceae)

    International Nuclear Information System (INIS)

    Lago, Joao Henrique G.; Carvalho, Larissa A.C.; Silva, Flavia S. da; Romoff, Paulete; Toyama, Daniela de O.; Favero, Oriana A.

    2010-01-01

    The essential oils from leaves and stem barks from Drimys brasiliensis Miers (Winteraceae) were individually obtained by hydrodistillation and their compounds characterized by use of GC/FID and GC/MS. The main identified derivatives were monoterpenes (leaves 4.31% and stem barks 90.02%) and sesquiterpenes (leaves 52.31% and stem barks 6.35%). Additionally, the sesquiterpene polygodial was isolated from hexane extract from stem barks of D. brasiliensis after chromatographic steps and characterized by spectroscopic means, mainly NMR. Aiming the evaluation of anti-inflammatory potential, the crude essential oils and the sesquiterpene polygodial were subjected to bioassays to evaluate the acute toxicity of these compounds as well as the anti-inflammatory and antinociceptive activities induced by carrageenan and formalin in mice. Ours results showed that essential oil obtained from the stem barks significantly reduced the oedema induced by carrageenan. The anti-inflammatory effect induced by stem barks oil (at 200 mg kg -1 ) was similar to observed for indomethacin (at 10 mg kg -1 ) and superior for polygodial (at 200 mg kg -1 ) in 30 and 60 min after the administration of essential oils. The inflammatory response induced by formalin was effective to the stem barks oil (62.5%) in comparison to polygodial (50.0%). (author)

  5. Total flavonoid content and antioxidant activity in leaves and stems extract of cultivated and wild tabat barito (Ficus deltoidea Jack)

    Science.gov (United States)

    Manurung, Hetty; Kustiawan, Wawan; Kusuma, Irawan W.; Marjenah

    2017-02-01

    Tabat barito (Ficus deltoidea Jack) is a name given by Dayak Tribe who lived in Borneo-Kalimantan and it is belongs to the moraceae. Almost all of the parts of F. deltoidea plant is widely used as a medicinal property. The total flavonoid content (TFC) and antioxidant activity from cultivated and wild F. deltoidea leaves and stems extract were assessed. Total flavonoid content was estimated by using Aluminium chloride colorimetric method and expressed as catechin equivalents (mg CE g-1 extract) and the antioxidant activity by the DPPH (2,2-diphenyl-1-picryl hydrazyl) method. The content of total flavonoid of leaves and stems (430.77 and 371.80 µg CE mg-1 extract) of cultivated F. deltoidea were higher than in the wild leaves and stems (114.82 and 66.67 µg CE mg-1 extract). The IC50 of leaves extract of cultivated and wild F. deltoidea, based on the DPPH assay, has a strong antioxidant activity (34.19 and 39.31 µg mL-1 extract) as compared to stems extract. These results showed that the cultivated F. deltoidea are suitable source for medicinal properties and the leaves could be exploited as source of natural antioxidants.

  6. The accumulation of two neolignan in the leaves, stems, and flower of red betel ( Piper crocatum Ruiz and Pav.)

    International Nuclear Information System (INIS)

    Hartini, Y S; Nugroho, L

    2017-01-01

    Organ for the biosynthesis of secondary metabolite is not always a place for its biosynthesis, even the same compound was synthesized in the different organs in different plants. Neolignan is a secondary metabolite, known as an imunostimulant, synthesized through shikimic acid pathway with the important precursor is chorismic acid. The compound was known to be accumulated in the roots, stems and leaves of Piper regnellii with the concentration varies depending on the type of neolignan. It has been investigated the accumulation of two compound neolignans (Pc-1 and Pc-2) isolated from the methanol extract of red betel leaf ( Piper crocatum Ruiz and Pav.) in the leaves, stems, and flowers of red betel. Chromatographic methods used was Gas Chromatography-Mass Spectrometry (GC-MS). Chromatogram of GC-MS showed that the Pc-1 with purity of 100%, m/z 460.3 could be detected at the minute of 29.986, while the Pc-2 with purity of 96.681%, m/z 418.3 was detected at the minute of 29.495. The research was then continued to investigate the existence and accumulation of both compounds in leaves, stems, and flowers of red betel. The GC-MS chromatogram shows that Pc-1 and Pc-2 could be detected in the leaves, stem and flower with various concentration among plant organs. Moreover, leaves contained the highest concentration of Pc-1 and Pc-2 compared to other plant organs. (paper)

  7. The accumulation of two neolignan in the leaves, stems, and flower of red betel (Piper crocatum Ruiz & Pav.)

    Science.gov (United States)

    Hartini, Y. S.; Nugroho, L.

    2017-05-01

    Organ for the biosynthesis of secondary metabolite is not always a place for its biosynthesis, even the same compound was synthesized in the different organs in different plants. Neolignan is a secondary metabolite, known as an imunostimulant, synthesized through shikimic acid pathway with the important precursor is chorismic acid. The compound was known to be accumulated in the roots, stems and leaves of Piper regnellii with the concentration varies depending on the type of neolignan. It has been investigated the accumulation of two compound neolignans (Pc-1 and Pc-2) isolated from the methanol extract of red betel leaf (Piper crocatum Ruiz & Pav.) in the leaves, stems, and flowers of red betel. Chromatographic methods used was Gas Chromatography-Mass Spectrometry (GC-MS). Chromatogram of GC-MS showed that the Pc-1 with purity of 100%, m/z 460.3 could be detected at the minute of 29.986, while the Pc-2 with purity of 96.681%, m/z 418.3 was detected at the minute of 29.495. The research was then continued to investigate the existence and accumulation of both compounds in leaves, stems, and flowers of red betel. The GC-MS chromatogram shows that Pc-1 and Pc-2 could be detected in the leaves, stem and flower with various concentration among plant organs. Moreover, leaves contained the highest concentration of Pc-1 and Pc-2 compared to other plant organs.

  8. Development of model for analysing respective collections of intended hematopoietic stem cells and harvests of unintended mature cells in apheresis for autologous hematopoietic stem cell collection.

    Science.gov (United States)

    Hequet, O; Le, Q H; Rodriguez, J; Dubost, P; Revesz, D; Clerc, A; Rigal, D; Salles, G; Coiffier, B

    2014-04-01

    Hematopoietic stem cells (HSCs) required to perform peripheral hematopoietic autologous stem cell transplantation (APBSCT) can be collected by processing several blood volumes (BVs) in leukapheresis sessions. However, this may cause granulocyte harvest in graft and decrease in patient's platelet blood level. Both consequences may induce disturbances in patient. One apheresis team's current purpose is to improve HSC collection by increasing HSC collection and prevent increase in granulocyte and platelet harvests. Before improving HSC collection it seemed important to know more about the way to harvest these types of cells. The purpose of our study was to develop a simple model for analysing respective collections of intended CD34+ cells among HSC (designated here as HSC) and harvests of unintended platelets or granulocytes among mature cells (designated here as mature cells) considering the number of BVs processed and factors likely to influence cell collection or harvest. For this, we processed 1, 2 and 3 BVs in 59 leukapheresis sessions and analysed corresponding collections and harvests with a referent device (COBE Spectra). First we analysed the amounts of HSC collected and mature cells harvested and second the evolution of the respective shares of HSC and mature cells collected or harvested throughout the BV processes. HSC collections and mature cell harvests increased globally (pcollections and harvests, which showed that only pre-leukapheresis blood levels (CD34+cells and platelets) influenced both cell collections and harvests (CD34+cells and platelets) (pcollections and mature unintended cells harvests (pcollections or unintended mature cell harvests were pre-leukapheresis blood cell levels. Our model was meant to assist apheresis teams in analysing shares of HSC collected and mature cells harvested with new devices or with new types of HSC mobilization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Structure of fructo-oligosaccharides from leaves and stem of Agave tequilana Weber, var. azul.

    Science.gov (United States)

    Praznik, Werner; Löppert, Renate; Cruz Rubio, Josè M; Zangger, Klaus; Huber, Anton

    2013-11-15

    Fructo-oligosaccharides (FOSs) of a six year old agave plant variety, Agave tequilana, were isolated and fractionated by 2D preparative chromatography (SEC and rpHPLC). Structural analyses of different FOS-fractions were performed by reductive methylation analysis connected to GC/FID identification and NMR-analysis. FOSs from leaves (d.p. 3-8) contain single α-d-Glcp residues as well in terminal as internal position, however (2→1)-linked β-d-Fruf residues only. FOSs from stem, however, contain as well (2→1)- and (2→6)-linked β-d-Fruf residues with branched oligomeric repeating units. These characteristics indicate an enzymatically catalyzed metabolic regulation for the biosynthesis and transformation of fructans in A. tequilana which strongly depends on location and transport activities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Cucurbitane-type triterpenoids from the stems and leaves of Momordica charantia.

    Science.gov (United States)

    Zhao, Gao-Ting; Liu, Jie-Qing; Deng, Yuan-Yuan; Li, Hai-Zhou; Chen, Jian-Chao; Zhang, Zhi-Run; Zhou, Lin; Qiu, Ming-Hua

    2014-06-01

    Six new cucurbitane-type triterpenoids, karavilagenin F (1), karavilosides XII and XIII (2, 3), momordicines VI, VII, and VIII (4, 5 and 6), along with four known ones, 5β,19-epoxy-25-methoxycucurbita-6,23-diene-3β,19-diol (7), 5β,19-epoxycucurbita-6, 23-diene-3β,19,25-triol (8), kuguacin R (9), and (19R,23E)-5β,19-epoxy-19-methoxycucurbita-6,23,25-trien-3β-ol (10), were isolated from the stems and leaves of Momordica charantia L. Their chemical structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, COSY, and ROESY), MS experiments, and CD spectrum. Compound 6 showed weak cytotoxicity against five human cancer cells lines with IC50 values of 14.3-20.5μmol/L. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Generation of induced pluripotent stem cell-derived mice by reprogramming of a mature NKT cell.

    Science.gov (United States)

    Ren, Yue; Dashtsoodol, Nyambayar; Watarai, Hiroshi; Koseki, Haruhiko; Quan, Chengshi; Taniguchi, Masaru

    2014-10-01

    NKT cells are characterized by their expression of an NKT-cell-specific invariant antigen-receptor α chain encoded by Vα14Jα18 gene segments. These NKT cells bridge the innate and acquired immune systems to mediate effective and augmented responses; however, the limited number of NKT cells in vivo hampers their analysis. Here, two lines of induced pluripotent stem cell-derived mice (NKT-iPSC-derived mice) were generated by reprogramming of mature NKT cells, where one harbors both rearranged Vα14Jα18 and Vβ7 genes and the other carries rearranged Vα14Jα18 on both alleles but germline Vβ loci. The analysis of NKT-iPSC-derived mice showed a significant increase in NKT cell numbers with relatively normal frequencies of functional subsets, but significantly enhanced in some cases, and acquired functional NKT cell maturation in peripheral lymphoid organs. NKT-iPSC-derived mice also showed normal development of other immune cells except for the absence of γδT cells and disturbed development of conventional CD4 αβT cells. These results suggest that the NKT-iPSC-derived mice are a better model for NKT cell development and function study rather than transgenic mouse models reported previously and also that the presence of a pre-rearranged Vα14Jα18 in the natural chromosomal context favors the developmental fate of NKT cells. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society for Immunology.

  12. Three-dimensional co-culture facilitates the differentiation of embryonic stem cells into mature cardiomyocytes.

    Science.gov (United States)

    Ou, Dong-Bo; He, Yong; Chen, Rui; Teng, Ji-Wei; Wang, Hong-Tao; Zeng, Di; Liu, Xiong-Tao; Ding, Lu; Huang, Jin-Yan; Zheng, Qiang-Sun

    2011-12-01

    The cardiomyocyte (CM) differentiation of embryonic stem cells (ESCs) is routinely cultured as two-dimensional (2D) monolayer, which doesn't mimic in vivo physiological environment and may lead to low differentiated level of ESCs. Here, we develop a novel strategy that enhances CM differentiation of ESCs in collagen matrix three-dimensional (3D) culture combined with indirect cardiac fibroblasts co-culture. ESCs were cultured in hanging drops to form embryoid bodies (EBs) and then applied on collagen matrix. The EBs were indirectly co-cultured with cardiac fibroblasts by the hanging cell culture inserts (PET 1 µm). The molecular expressions and ultrastructural characteristics of ESC-derived CMs (ESCMs) were analyzed by real time RT-PCR, immunocytochemistry, and Transmission Electron Microscopy (TEM). We found that the percentage of beating EBs with cardiac fibroblasts co-culture was significantly higher than that without co-culture after differentiation period of 8 days. Type I collagen used as 3D substrates enhanced the late-stage CM differentiation of ESCs and had effect on ultrastructural mature of ESCMs in late-stage development. The combined effects of 3D and co-culture that mimic in vivo physiological environment further improved the efficiency of CM differentiation from ESCs, resulting in fiber-like structures of cardiac cells with organized sarcomeric structure in ESCMs. This novel 3D co-culture system emphasizes the fact that the ESC differentiation is actively responding to cues from their environment and those cues can drive phenotypic control, which provides a useful in vitro model to investigate CM differentiation of stem cells. Copyright © 2011 Wiley Periodicals, Inc.

  13. Essential oils and crude extracts from Chrysanthemum trifurcatum leaves, stems and roots: chemical composition and antibacterial activity.

    Science.gov (United States)

    Sassi, Ahlem Ben; Skhiri, Fethia Harzallah; Chraief, Imed; Bourgougnon, Nathalie; Hammami, Mohamed; Aouni, Mahjoub

    2014-01-01

    The essential oils from the leaves, stems and roots of Chrysanthemum trifurcatum (Desf.) Batt. and Trab. var. macrocephalum (viv.) were obtained by hydrodistillation and their chemical compositions were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), in order to get insight into similarities and differences as to their active composition. A total of fifty compounds were identified, constituting 97.84%, 99.02% and 98.20% of total oil composition of the leaves, stems and roots, respectively. Monoterpene hydrocarbons were shown to be the main group of constituents of the leaves and stems parts in the ratio of 67.88% and 51.29%, respectively. But, the major group in the roots oil was found to be sesquiterpene hydrocarbons (70.30%). The main compounds in leaves oil were limonene (26.83%), γ-terpinene (19.68%), α-pinene (9.7%) and α-terpenyl acetate (7.16%). The stems oil, contains mainly limonene (32.91%), 4-terpenyl acetate (16.33%) and γ-terpinene (5.93%), whereas the main compounds in roots oil were α-calacorene (25.98%), α-cedrene (16.55%), β-bourbobene (14.91%), elemol (7.45%) and 2-hexenal (6.88%). The crude organic extracts of leaves, stems and roots, obtained by maceration with solvents of increasing polarity: petroleum ether, ethyl acetate and methanol, contained tannins, flavonoids and alkaloids. Meanwhile, essential oils and organic extracts were tested for antibacterial activities against eight Gram-positive and Gram-negative strains, using a microdilution method. The oil and methanolic extact from C. trifurcatum leaves showed a great potential of antibacterial effect against Bacillus subtilis and Staphylococcus epidermidis, with an IC50 range of 31.25-62.5 µg/ml.

  14. [Comparison on polysaccharide content and PMP-HPLC fingerprints of polysaccharide in stems and leaves of Dendrobium officinale].

    Science.gov (United States)

    Zhou, Gui-Fen; Pang, Min-Xia; Chen, Su-Hong; Lv, Gui-Yuan; Yan, Mei-Qiu

    2014-03-01

    In order to provide scientific basics for exploitation and sufficient application of Dendrobium officinale leaves resources, the phenol-sulfuric acid method was applied to determine the polysaccharide content. The monosaccharides were derivated by PMP and the derivatives were identified by HPLC-DAD-ESI-MS(n) and the contents of mannose and glucose were determined simultaneously. Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004A) was employed to generate the mean chromatogram and similarity analysis of the samples was carried out. The results demonstrated that polysaccharide content, monosaccharide compositions and composition ratio had an obvious difference between stems and leaves. The polysaccharide content of stems was higher than that of leaves. Monosaccharide composition in leaf was significantly different from that in stem. The polysaccharide from stems was composed of mannose and glucose, however the polysaccharide of leaves was acid heteropolysaccharide and was mainly composed of five monosaccharides, including mannose, galacturonic acid, glucose, galactose and arabinose. The similarity value of the 14 batches was above 0.9, indicating that similarity of fingerprints among different samples was high. The study can provide evidence for expanding the medicinal parts of D. officinale.

  15. Hydraulic safety margins and embolism reversal in stems and leaves: Why are conifers and angiosperms so different?

    Science.gov (United States)

    Daniel M. Johnson; Katherine A. McCulloh; David R. Woodruff; Frederick C. Meinzer

    2012-01-01

    Angiosperm and coniferous tree species utilize a continuum of hydraulic strategies. Hydraulic safety margins (defined as differences between naturally occurring xylem pressures and pressures that would cause hydraulic dysfunction, or differences between pressures resulting in loss of hydraulic function in adjacent organs (e.g., stems vs. leaves) tend to be much greater...

  16. Extracellular Matrix-Mediated Maturation of Human Pluripotent Stem Cell-Derived Cardiac Monolayer Structure and Electrophysiological Function.

    Science.gov (United States)

    Herron, Todd J; Rocha, Andre Monteiro Da; Campbell, Katherine F; Ponce-Balbuena, Daniela; Willis, B Cicero; Guerrero-Serna, Guadalupe; Liu, Qinghua; Klos, Matt; Musa, Hassan; Zarzoso, Manuel; Bizy, Alexandra; Furness, Jamie; Anumonwo, Justus; Mironov, Sergey; Jalife, José

    2016-04-01

    Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) monolayers generated to date display an immature embryonic-like functional and structural phenotype that limits their utility for research and cardiac regeneration. In particular, the electrophysiological function of hPSC-CM monolayers and bioengineered constructs used to date are characterized by slow electric impulse propagation velocity and immature action potential profiles. Here, we have identified an optimal extracellular matrix for significant electrophysiological and structural maturation of hPSC-CM monolayers. hPSC-CM plated in the optimal extracellular matrix combination have impulse propagation velocities ≈2× faster than previously reported (43.6±7.0 cm/s; n=9) and have mature cardiomyocyte action potential profiles, including hyperpolarized diastolic potential and rapid action potential upstroke velocity (146.5±17.7 V/s; n=5 monolayers). In addition, the optimal extracellular matrix promoted hypertrophic growth of cardiomyocytes and the expression of key mature sarcolemmal (SCN5A, Kir2.1, and connexin43) and myofilament markers (cardiac troponin I). The maturation process reported here relies on activation of integrin signaling pathways: neutralization of β1 integrin receptors via blocking antibodies and pharmacological blockade of focal adhesion kinase activation prevented structural maturation. Maturation of human stem cell-derived cardiomyocyte monolayers is achieved in a 1-week period by plating cardiomyocytes on PDMS (polydimethylsiloxane) coverslips rather than on conventional 2-dimensional cell culture formats, such as glass coverslips or plastic dishes. Activation of integrin signaling and focal adhesion kinase is essential for significant maturation of human cardiac monolayers. © 2016 American Heart Association, Inc.

  17. Analysis of essential oils of leaves, stems, flowers and rhizomes of Etlingera elatior (Jack) R.M. Smith

    International Nuclear Information System (INIS)

    Faridahanim Mohd Jaafar; Che Puteh Osman; Nor Hadiani Ismail; Khalijah Awang

    2007-01-01

    The essential oils from leaves, stems, flowers and rhizomes of Etlingera elatior, an aromatic plant that are widely used in traditional medicine and as a flavour in local dishes were extracted. The essential oils were extracted using the hydro distillation method and analysed by GC-MS. The percentage yield of volatile constituents of the leaves, stems, flowers and rhizomes were 0.0735%, 0.0029%, 0.0334% and 0.0021%, respectively. The leaf essential oil contained β- pinene (19.7%), caryophyllene (15.36%) and (E)-β-farnesene (27.90%) as major compounds whereas the stem essential oil were largely dominated by 1,1-dodecanediol diacetate (34.26%) and (E)-5-dodecane (26.99%). The essential oils of the flowers and rhizomes contained the major compounds 1, 1- dodecanediol diacetate (24.38% and 40.37% respectively) and cyclododecane (47.28% and 34.45% respectively). (author)

  18. Hybrid Sequencing of Full-Length cDNA Transcripts of Stems and Leaves in Dendrobium officinale

    Directory of Open Access Journals (Sweden)

    Liu He

    2017-10-01

    Full Text Available Dendrobium officinale is an extremely valuable orchid used in traditional Chinese medicine, so sought after that it has a higher market value than gold. Although the expression profiles of some genes involved in the polysaccharide synthesis have previously been investigated, little research has been carried out on their alternatively spliced isoforms in D. officinale. In addition, information regarding the translocation of sugars from leaves to stems in D. officinale also remains limited. We analyzed the polysaccharide content of D. officinale leaves and stems, and completed in-depth transcriptome sequencing of these two diverse tissue types using second-generation sequencing (SGS and single-molecule real-time (SMRT sequencing technology. The results of this study yielded a digital inventory of gene and mRNA isoform expressions. A comparative analysis of both transcriptomes uncovered a total of 1414 differentially expressed genes, including 844 that were up-regulated and 570 that were down-regulated in stems. Of these genes, one sugars will eventually be exported transporter (SWEET and one sucrose transporter (SUT are expressed to a greater extent in D. officinale stems than in leaves. Two glycosyltransferase (GT and four cellulose synthase (Ces genes undergo a distinct degree of alternative splicing. In the stems, the content of polysaccharides is twice as much as that in the leaves. The differentially expressed GT and transcription factor (TF genes will be the focus of further study. The genes DoSWEET4 and DoSUT1 are significantly expressed in the stem, and are likely to be involved in sugar loading in the phloem.

  19. Cadmium tolerance and accumulation characteristics of mature flax, cv. Hermes: Contribution of the basal stem compared to the root

    Energy Technology Data Exchange (ETDEWEB)

    Douchiche, Olfa, E-mail: olfa.douchiche@hotmail.fr [Laboratory Glyco-MEV EA 4358, IFRMP 23, University of Rouen, 76821 Mont Saint Aignan Cedex (France); Laboratory Biologie et Physiologie Cellulaires Vegetales, Department of Biology, University of Tunis, 1060 Tunis (Tunisia); Chaiebi, Wided [Laboratory Biologie et Physiologie Cellulaires Vegetales, Department of Biology, University of Tunis, 1060 Tunis (Tunisia); Morvan, Claudine, E-mail: claudine.morvan@univ-rouen.fr [Laboratory PBS-UMR 6270 CNRS, FR 3038, University of Rouen, 76821 Mont Saint Aignan Cedex (France)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cd accumulated in stem bottom part exceeded the defined hyperaccumulator threshold. Black-Right-Pointing-Pointer No toxic symptoms occurred and TI of all growth parameters ranged between 0.7 and 1. Black-Right-Pointing-Pointer The high level of Zn, Mn and Cu may contribute to the absence of chlorosis in stem. Black-Right-Pointing-Pointer Cd/Ca synergistic effect observed in the stem may alleviate Cd toxicity. Black-Right-Pointing-Pointer Hermes variety accumulated more Cd than the other flax varieties ever described. - Abstract: The potential of mature flax plants (cv. Hermes) to tolerate and accumulate cadmium (Cd) was studied to determine which part of the plant would be the key organ for phytoremediation purposes. After 4 month-growth on sand substrate containing 0.1 mM Cd in a greenhouse, the roots and stems were separated and the stems were divided into three parts. The effects of Cd were studied on growth parameters, histology and mineral nutrition. No visible toxic symptoms were observed. Tolerance-index values calculated from growth parameters and nutrients remained relatively high, allowing the development of the plant until maturity and formation of seeds. The roots and bottom stem accumulated the highest quantity of Cd (750 and 360 mg/kg dry matter), values which largely exceeded the threshold defined for hyperaccumulators. On the other hand, basal stem had a high bioconcentration factor (BCF = 32) and translocation factor TF Prime (2.5) but a low TF (0.5), indicating that this basal part would play a major role in phytoremediation (phytostabilization rather than phytorextraction). Therefore, the high tolerance to Cd and accumulation capacity make possible to grow Hermes flax on Cd-polluted soils.

  20. Assessment of the medicinal potentials of the methanol extracts of the leaves and stems of Buddleja saligna.

    Science.gov (United States)

    Adedapo, Adeolu A; Jimoh, Florence O; Koduru, Srinivas; Masika, Patrick J; Afolayan, Anthony J

    2009-07-06

    Buddleja saligna Willd (Loganiaceae) is a small to medium-sized evergreen tree; trunk short, often gnarled and crooked; crown dense, rounded or domed-shaped; foliage greyish green. The wild olives are traditionally used to lower blood pressures in many parts of the world. In southern Africa, bark and leaf decoctions are used to treat colic, coughs, colds, sore eyes, urinary problems and as purgatives. The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Buddleja saligna were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the leaves and stem extracts of Buddleja saligna were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant. The antioxidant activities of the leaves as determined by the ABTS and DPPH were similar to that of the stem. The flavonoids and the flavonols contents of the leaves were higher than that of the stem but the total phenols, proanthocyanidins and FRAP activities were higher in the methanol extracts of the stem. The extracts did show activity against both Gram-positive and Gram-negative bacteria. For instance, while the methanol extract of the leaves showed good activities on all the organisms except Serratia marcescens and Pseudomonas aeruginosa at MICs of between 2.5 and 5.0 mg/ml, the extract of the stem only showed activities on Bacillus cereus, Streptococcus pyrogens and Pseudomonas aeruginosa at the same concentration. The results from this study indicate that the leaves and stem extracts of Buddleja saligna possess antioxidant properties and could serve as

  1. Assessment of the medicinal potentials of the methanol extracts of the leaves and stems of Buddleja saligna

    Directory of Open Access Journals (Sweden)

    Masika Patrick J

    2009-07-01

    Full Text Available Abstract Background Buddleja saligna Willd (Loganiaceae is a small to medium-sized evergreen tree; trunk short, often gnarled and crooked; crown dense, rounded or domed-shaped; foliage greyish green. The wild olives are traditionally used to lower blood pressures in many parts of the world. In southern Africa, bark and leaf decoctions are used to treat colic, coughs, colds, sore eyes, urinary problems and as purgatives. Methods The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Buddleja saligna were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the leaves and stem extracts of Buddleja saligna were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant. Results The antioxidant activities of the leaves as determined by the ABTS and DPPH were similar to that of the stem. The flavonoids and the flavonols contents of the leaves were higher than that of the stem but the total phenols, proanthocyanidins and FRAP activities were higher in the methanol extracts of the stem. The extracts did show activity against both Gram-positive and Gram-negative bacteria. For instance, while the methanol extract of the leaves showed good activities on all the organisms except Serratia marcescens and Pseudomonas aeruginosa at MICs of between 2.5 and 5.0 mg/ml, the extract of the stem only showed activities on Bacillus cereus, Streptococcus pyrogens and Pseudomonas aeruginosa at the same concentration. Conclusion The results from this study indicate that the leaves and stem extracts of

  2. Mechanosensitivity of dental pulp stem cells is related to their osteogenic maturity

    DEFF Research Database (Denmark)

    Kraft, David C E; Bindslev, Dorthe A; Melsen, Birte

    2010-01-01

    -mature exhibited higher osteocalcin and alkaline phosphatase gene expression and activity than PDSC-immature. Pulsating fluid flow (PFF) stimulated nitric oxide production within 5 min by PDSC-mature but not by PDSC-immature. In PDSC-mature, PFF induced prostaglandin E(2) production, and cyclooxygenase 2 gene...

  3. Cooperative transcription activation by Nurr1 and Pitx3 induces embryonic stem cell maturation to the midbrain dopamine neuron phenotype

    DEFF Research Database (Denmark)

    Martinat, Cecile; Bacci, Jean-Jacques; Leete, Thomas

    2006-01-01

    's disease. We sought to identify genes that can potentiate maturation of ES cell cultures to the midbrain DA neuron phenotype. A number of transcription factors have been implicated in the development of midbrain DA neurons by expression analyses and loss-of-function knockout mouse studies, including Nurr1......Midbrain dopamine (DA) neurons play a central role in the regulation of voluntary movement, and their degeneration is associated with Parkinson's disease. Cell replacement therapies, and in particular embryonic stem (ES) cell-derived DA neurons, offer a potential therapeutic venue for Parkinson......, Pitx3, Lmx1b, Engrailed-1, and Engrailed-2. However, none of these factors appear sufficient alone to induce the mature midbrain DA neuron phenotype in ES cell cultures in vitro, suggesting a more complex regulatory network. Here we show that Nurr1 and Pitx3 cooperatively promote terminal maturation...

  4. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots.

    Science.gov (United States)

    Reich, Peter B; Luo, Yunjian; Bradford, John B; Poorter, Hendrik; Perry, Charles H; Oleksyn, Jacek

    2014-09-23

    Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

  5. Osteogenic stimulatory conditions enhance growth and maturation of endothelial cell microvascular networks in culture with mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Torbjorn O Pedersen

    2012-12-01

    Full Text Available To optimize culture conditions for in vitro prevascularization of tissue-engineered bone constructs, the development of organotypic blood vessels under osteogenic stimulatory conditions (OM was investigated. Coculture of endothelial cells and mesenchymal stem cells was used to assess proangiogenic effects of mesenchymal stem cells on endothelial cells. Four different culture conditions were evaluated for their effect on development of microvascular endothelial cell networks. Mineralization, deposition of extracellular matrix, and perivascular gene expression were studied in OM. After 3 days, endothelial cells established elongated capillary-like networks, and upregulated expression of vascular markers was seen. After 15 days, all parameters evaluated were significantly increased for cultures in OM. Mature networks developed in OM presented lumens enveloped by basement membrane-like collagen IV, with obvious mineralization and upregulated perivascular gene expression from mesenchymal stem cells. Our results suggest osteogenic stimulatory conditions to be appropriate for in vitro development of vascularized bone implants for tissue engineering.

  6. Defined MicroRNAs Induce Aspects of Maturation in Mouse and Human Embryonic-Stem-Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Desy S. Lee

    2015-09-01

    Full Text Available Pluripotent-cell-derived cardiomyocytes have great potential for use in research and medicine, but limitations in their maturity currently constrain their usefulness. Here, we report a method for improving features of maturation in murine and human embryonic-stem-cell-derived cardiomyocytes (m/hESC-CMs. We found that coculturing m/hESC-CMs with endothelial cells improves their maturity and upregulates several microRNAs. Delivering four of these microRNAs, miR-125b-5p, miR-199a-5p, miR-221, and miR-222 (miR-combo, to m/hESC-CMs resulted in improved sarcomere alignment and calcium handling, a more negative resting membrane potential, and increased expression of cardiomyocyte maturation markers. Although this could not fully phenocopy all adult cardiomyocyte characteristics, these effects persisted for two months following delivery of miR-combo. A luciferase assay demonstrated that all four miRNAs target ErbB4, and siRNA knockdown of ErbB4 partially recapitulated the effects of miR-combo. In summary, a combination of miRNAs induced via endothelial coculture improved ESC-CM maturity, in part through suppression of ErbB4 signaling.

  7. Bioinspired onion epithelium-like structure promotes the maturation of cardiomyocytes derived from human pluripotent stem cells.

    Science.gov (United States)

    Xu, Cong; Wang, Li; Yu, Yue; Yin, Fangchao; Zhang, Xiaoqing; Jiang, Lei; Qin, Jianhua

    2017-08-22

    Organized cardiomyocyte alignment is critical to maintain the mechanical properties of the heart. In this study, we present a new and simple strategy to fabricate a biomimetic microchip designed with an onion epithelium-like structure and investigate the guided behavior of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) on the substrate. The hiPSC-CMs were observed to be confined by the three dimensional surficial features morphologically, analogous to the in vivo microenvironment, and exhibited an organized anisotropic alignment on the onion epithelium-like structure with good beating function. The calcium imaging of hiPSC-CMs demonstrated a more mature Ca 2+ spark pattern as well. Furthermore, the expression of sarcomere genes (TNNI3, MYH6 and MYH7), potassium channel genes (KCNE1 and KCNH2), and calcium channel genes (RYR2) was significantly up-regulated on the substrate with an onion epithelium-like structure instead of the surface without the structure, indicating a more matured status of cardiomyocytes induced by this structure. It appears that the biomimetic micropatterned structure, analogous to in vivo cellular organization, is an important factor that might promote the maturation of hiPSC-CMs, providing new biological insights to guide hiPSC-CM maturation by biophysical factors. The established approach may offer an effective in vitro model for investigating cardiomyocyte differentiation, maturation and tissue engineering applications.

  8. Anti-inflammatory, antiallodynic effects and quantitative analysis of gallic acid in spray dried powders from Phyllanthus niruri leaves, stems, roots and whole plant

    Directory of Open Access Journals (Sweden)

    Angélica G. Couto

    2012-11-01

    Full Text Available The anti-inflammatory and antiallodynic effects of spray dried powders starting from leaves, stems, roots, the mixture of leaves and stems, as well as the whole plant aqueous solutions of Phyllanthus niruri L., Phyllanthaceae, were assessed. Gallic acid, used as chemical marker, was quantified by HPLC in the spray dried powders. Carrageenan-induced inflammatory and allodynic responses in the mouse paw were used as pharmacological models. Quantitative and qualitative differences among chemical composition of different herb parts were observed. The oral administration of leaves or leaves plus stems spray dried powders (100 mg/kg significantly inhibited the carrageenan-induced allodynic effect (42±5 and 54±3%, respectively. Additionally, the spray dried powders of leaves significantly reduced carrageenan-induced paw oedema (35±6%. The spray dried powders of roots, stems, or the mixture of leaves, stems and roots (100 mg/kg, p.o. did not exhibit antiallodynic or antioedematogenic effect in the same model. In conclusion, differences in the chemical composition of spray dried powders from P. niruri are reflected in their in vivo pharmacological actions. Despite of a direct relationship of anti-inflammatory and antiallodynic effects with the gallic acid content had been observed, especially in the spray dried powders of leaves, the use of spray dried powders of leaves plus stems showed to be more effective, suggesting a synergic effect between their constituents.

  9. Anti-inflammatory, antiallodynic effects and quantitative analysis of gallic acid in spray dried powders from Phyllanthus niruri leaves, stems, roots and whole plant

    Directory of Open Access Journals (Sweden)

    Angélica G. Couto

    2013-02-01

    Full Text Available The anti-inflammatory and antiallodynic effects of spray dried powders starting from leaves, stems, roots, the mixture of leaves and stems, as well as the whole plant aqueous solutions of Phyllanthus niruri L., Phyllanthaceae, were assessed. Gallic acid, used as chemical marker, was quantified by HPLC in the spray dried powders. Carrageenan-induced inflammatory and allodynic responses in the mouse paw were used as pharmacological models. Quantitative and qualitative differences among chemical composition of different herb parts were observed. The oral administration of leaves or leaves plus stems spray dried powders (100 mg/kg significantly inhibited the carrageenan-induced allodynic effect (42±5 and 54±3%, respectively. Additionally, the spray dried powders of leaves significantly reduced carrageenan-induced paw oedema (35±6%. The spray dried powders of roots, stems, or the mixture of leaves, stems and roots (100 mg/kg, p.o. did not exhibit antiallodynic or antioedematogenic effect in the same model. In conclusion, differences in the chemical composition of spray dried powders from P. niruri are reflected in their in vivo pharmacological actions. Despite of a direct relationship of anti-inflammatory and antiallodynic effects with the gallic acid content had been observed, especially in the spray dried powders of leaves, the use of spray dried powders of leaves plus stems showed to be more effective, suggesting a synergic effect between their constituents.

  10. Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems

    Directory of Open Access Journals (Sweden)

    William Patrick Cruiz Buhian

    2017-02-01

    Conclusions: M. calabura exhibited very high antioxidant activity in its leaves and stems ethanol extracts, both of which are used in traditional medicine. The TLC results demonstrated the presence of diverse secondary metabolites in the leaf and stem ethanol extracts, indicating that the antioxidant activity, including other bioactivities may be attributed to these phytochemical constituents. This paper has reported for the first time the TLC fingerprinting of M. calabura using visible light, UV 254 nm, UV 366 and post-derivatization with vanillin-spray to visualize separate spots on TLC plates.

  11. Determination of a various ions such as alkali metals in leaves, stems, roots and seeds of the radish and their distribution

    International Nuclear Information System (INIS)

    Fujino, Osamu; Matsui, Masakazu.

    1995-01-01

    Determination, uptake and distribution of various ions such as alkali metals in three different parts (leaf, stem and root) and seeds of radish (Kaiware daikon) were examined using flame emission spectrometry and ICP-AES. In order to examine the influence of concentration alkali metal ion concentration in the radish culture solution on the uptake and distribution of these metals, the radish was grown at pH 5.6 in solutions containing alkali metal chloride at concentrations ranging from 10 -5 to 10 -1 mol dm -3 . When the radish were grown in culture solution with alkali metal ions of low concentrations (10 -5 and 10 -4 mol dm -3 ), Na, K, Rb and trace Li were detected in leaves, stems and roots while Cs was scarcely detected. However, the contents of Na, K, Li in these organs were the same as those in radish cultivated in pure water. An increase of Rb uptake was observed with an increased Rb concentration. In the case of high concentrations (10 -3 and 10 -2 mol dm -3 ) of alkali metals in culture solution, the all alkali ions uptake of all alkali ions suddenly accelerated. Moreover, at concentrations higher than 0.1 mol dm -3 , the radish germinated poorly and did not completely mature. (author)

  12. Biomass production and essential oil yield from leaves, fine stems and resprouts using pruning the crown of Aniba canelilla (H.B.K.) (Lauraceae) in the Central Amazon

    OpenAIRE

    Manhães,Adriana Pellegrini; Veiga-Júnior,Valdir Florêncio da; Wiedemann,Larissa Silveira Moreira; Fernandes,Karenn Silveira; Sampaio,Paulo de Tarso Barbosa

    2012-01-01

    Aniba canelilla (H.B.K.) Mez. is a tree species from Amazon that produces essential oil. The oil extraction from its leaves and stems can be an alternative way to avoid the tree cutting for production of essential oil. The aim of this study was to analyse factors that may influence the essential oil production and the biomass of resprouts after pruning the leaves and stems of A. canelilla trees. The tree crowns were pruned in the wet season and after nine months the leaves and stems of the re...

  13. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    OpenAIRE

    K. Al-Mughrabi

    2003-01-01

    Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. ...

  14. Quantitative determination of total and individual flavonoids in stems and leaves of Buddleja davidii and Buddleja albiflora

    OpenAIRE

    Ying, Cheng; Wan, Dingrong

    2012-01-01

    Background: Buddleja davidii and B. albiflora are two different original plants of the famous crude medicine "Diaoyangchen." Materials and Methods: An ultraviolet-visible spectrophotometric method and a HPLC method were used for the determination of total and individual flavonoids (luteolin and apigenin) contents from their stems and leaves for the first time. Results: From the comparative evaluation, remarkable differences in flavonoids contents were observed between different origins and di...

  15. Effects of Harvest Maturity on Quality of Cured Tobacco Leaves%采收成熟度对烟叶烤后质量的影响

    Institute of Scientific and Technical Information of China (English)

    王行; 张敏坚; 何振峰

    2017-01-01

    The mature harvest standard of enriched flavour flue-cured tobacco was determined by the test and evaluation of tobacco leaf appearance characteristics and chemical components of tobacco leaves of variety ‘Yueyan 98’,to explore the influence of intensive flue-curing condition on tobacco leaf quality in different harvest maturity periods.Results showed that the best harvested period of upper,middle and lower tobacco leaves in Shaoguan tobacco planting area was the optimum ripeness stage.Through bulk curing,the propotion of orange tobacco leaves increased.The appearance characteristics included brightness of colour and lustre,strong chromaticity and abundant oil content.As to the chemical components of upper,middle and lower taobacco leaves,the sugar alkali ratio and alkali nitrogen ratio were well coordinated.The leaves had sufficient and high quality amora,which manifested the characteristics of enriched flavor flue-cured tobacco.%为明确密集烘烤条件下浓香型烤烟各部位烟叶成熟采收标准,通过对‘粤烟98’品种烟叶外观特性、化学成分感官质量评价,探究其在不同采收成熟度对烟叶品质的影响.结果表明:在韶关烟区烤烟烟叶以下、中、上部达到适熟期采收最佳,烤后烟叶橘黄烟比例增加,色泽光亮、色度强及油分好,各部位烟叶化学成分糖碱比和氮碱比协调性相对较好,香气质好量足,在一定程度上彰显了烟叶浓香型特征.

  16. Chemical diversity of essential oils from flowers, leaves, and stems of Rhanterium epapposum Oliv. growing in northern border region of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Marwa Awad

    2016-09-01

    Conclusions: Essential oils from flowers, leaves and stems of R. epapposum growing in northern border region of Saudi Arabia are considered as a rich source of monoterpenes which have biological activities.

  17. Cytotoxicity of latex and pharmacobotanical study of leaves and stem of Euphorbia umbellata (Janaúba

    Directory of Open Access Journals (Sweden)

    Lívia E.C. Luz

    Full Text Available AbstractIn southern Brazil, the bottled latex of Synadenium grantii Hook f., Euphorbiaceae, is popularly used as a treatment of all types of cancer. Similarly, Synadenium umbellatum Pax. is used in the central western region of Brazil for the same purpose and in the same manner of use. Both plants are popularly known as janaúba or leitosinha. The objectives of this study were to use pharmacobotanical analysis to verify whether these two species, which are considered to be distinct, are actually the same to determine anatomical markers; to assist in the identification and differentiation of other Euphorbia; and to evaluate the cytotoxic activity of the latex in relation to HeLa and HRT-18 cells. Leaves and stems of the species were collected in Goiânia and Ponta Grossa and were investigated using scanning electron microscopy and optical microscopy techniques. The latex was also collected and analyzed in relation to its cytotoxic effect by employing MTT and NR techniques. The pharmacobotanical study of the specimens in both localities showed that they were the same species, namely Euphorbia umbellata (Pax Bruyns, which is the scientific nomenclature accepted and confirmed by an expert taxonomist who specializes in Euphorbia. The pharmacobotanical characteristics highlighted in this study can assist in the identification of the taxon and contribute to the control of the quality of this plant drug. The evaluation of the latex in relation to HRT-18 cells demonstrated action after 48 h of experiment. In contrast, in relation to HeLa cells its induced cytotoxicity in all times and a dose-dependent manner. The IC50 values (72 h observed were 252.58 ± 18.51 µg/ml and 263.42 ± 15.92 µg/ml to MTT experiment and 250.18 ± 19.48 µg/ml and 430.56 ± 19.71 µg/ml to NR experiment for the HeLa and HRT-18 cells, respectively.

  18. Fatty acid composition and antibacterial potential of Cassia tora (leaves and stem collected from different geographic areas of India

    Directory of Open Access Journals (Sweden)

    Shipra Shukla

    2018-01-01

    Full Text Available The comparative analysis of the fatty acid composition of Cassia tora (leaves and stem was determined using gas chromatography–mass spectrometry. Twenty-seven fatty acids were identified in C. tora (leaves and stem which was collected from three different geographical areas of India: Lucknow (Uttar Pradesh, Nainital (Uttarakhand, and Bhavnagar (Gujarat, coded as CT-1, CT-2, and CT-3, respectively. The gas chromatography–mass spectrometry analysis showed the presence of various saturated and unsaturated fatty acids. The major fatty acids found were palmitic acid, linoleic acid, linolenic acid, margaric acid, melissic acid, and behenic acid. The highest amounts of saturated fatty acids were found in leaves of C. tora collected from Bhavnagar (Gujarat (60.7% ± 0.5%. Thus, the study reveals that C. tora has a major amount of nutritionally important fatty acids, along with significant antimicrobial potential. Fatty acids play a significant role in the development of fat products with enhanced nutritional value and clinical application. Remarkable differences were found in the present study between fatty acid profiles of C. tora collected from different locations in India. To the best of our knowledge there is no previously reported comparative study of the fatty acids of C. tora.

  19. Quantification of Catechin in Leaves and Stems of Malaysian Uncaria Gambir (Hunter) ROXB. by HPLC-DAD

    International Nuclear Information System (INIS)

    Nurliayana Ibrahim; Nurul Zulaikha Mohd Yusoff; Rohaya Ahmad; Rohaya Ahmad

    2016-01-01

    Recently, we reported the isolation of a novel flavonoid named uncariechin along with epicatechin and epiafzelechin from the leaf extract of Uncaria longiflora variety pteropoda (Miq.) Ridsd. of the family Rubiaceae. Continuing our investigation on the Uncaria genus, the identification and quantification of its phytoconstituents was carried out. The species of particular interest is the Malaysian Uncaria gambir. This species is distributed mainly in Malaysia and Indonesia and has been cultivated for the flavonoid catechin in Indonesia. Hence, the objective of this study is to determine the quantity of catechin in hexane (Hx), dichloromethane (DCM) and methanol (MeOH) extracts in both stem and leaf parts of the plant via HPLC-DAD. Our findings indicate that catechin is present in higher amounts in the MeOH extract [8.64 % (leaves); 5.12 % (stems)] compared to the DCM extract [0.77 % (leaves); 0.92 % (stems)] with no catechin found in the hexane extract. This is the first report of the quantification of catechin from Malaysian U. gambir using HPLC-DAD. The method can be used for the quantification of flavonoids from other Uncaria and related genus and is useful for targeted isolation of interest flavonoids. (author)

  20. Quantitative elemental localisation in leaves and stems of nickel hyperaccumulating shrub Hybanthusfloribundus subsp. floribundus using micro-PIXE spectroscopy

    International Nuclear Information System (INIS)

    Kachenko, Anthony G; Singh, Balwant; Bhatia, Naveen P; Siegele, Rainer

    2008-01-01

    Hybanthusfloribundus (Lindl.) F.Muell. subsp. floribundus is a native Australian nickel (Ni) hyperaccumulating shrub and a promising species for rehabilitation and phytoremediation of Ni tailings. Spatial localisation and quantification of Ni in leaf and stem tissues of H.floribundus subsp. floribundus was studied using micro-proton-induced X-ray emission (micro-PIXE) spectroscopy. Young plants, grown in a potting mix under controlled glasshouse conditions were exposed to Ni concentrations of 0 and 26 mM kg -1 for 20 weeks. Leaf and stem samples were hand-sectioned and freeze-dried prior to micro-PIXE analysis. Elemental distribution maps of leaves revealed Ni concentration of 7800 mg kg -1 dry weight (DW) in whole leaf sections, which was identical to the bulk tissue analysis. Elemental maps showed that Ni was preferentially localised in the adaxial epidermis (10,000 mg kg -1 DW) and reached a maximum of up to 10,000 mg kg -1 DW in the leaf margin. Freeze-dried stem sections from the same plants contained lower Ni than leaf tissues (1800 mg kg -1 versus 7800 mg kg -1 DW, respectively), however did not resolve a clear pattern of compartmentalisation across different anatomical regions. Our results suggest localisation in epidermal cells is an important physiological mechanism involved in Ni accumulation and tolerance in leaves of H.floribundus subsp. floribundus

  1. Enhanced elastin synthesis and maturation in human vascular smooth muscle tissue derived from induced-pluripotent stem cells.

    Science.gov (United States)

    Eoh, Joon H; Shen, Nian; Burke, Jacqueline A; Hinderer, Svenja; Xia, Zhiyong; Schenke-Layland, Katja; Gerecht, Sharon

    2017-04-01

    Obtaining vascular smooth muscle tissue with mature, functional elastic fibers is a key obstacle in tissue-engineered blood vessels. Poor elastin secretion and organization leads to a loss of specialization in contractile smooth muscle cells, resulting in over proliferation and graft failure. In this study, human induced-pluripotent stem cells (hiPSCs) were differentiated into early smooth muscle cells, seeded onto a hybrid poly(ethylene glycol) dimethacrylate/poly (l-lactide) (PEGdma-PLA) scaffold and cultured in a bioreactor while exposed to pulsatile flow, towards maturation into contractile smooth muscle tissue. We evaluated the effects of pulsatile flow on cellular organization as well as elastin expression and assembly in the engineered tissue compared to a static control through immunohistochemistry, gene expression and functionality assays. We show that culturing under pulsatile flow resulted in organized and functional hiPSC derived smooth muscle tissue. Immunohistochemistry analysis revealed hiPSC-smooth muscle tissue with robust, well-organized cells and elastic fibers and the supporting microfibril proteins necessary for elastic fiber assembly. Through qRT-PCR analysis, we found significantly increased expression of elastin, fibronectin, and collagen I, indicating the synthesis of necessary extracellular matrix components. Functionality assays revealed that hiPSC-smooth muscle tissue cultured in the bioreactor had an increased calcium signaling and contraction in response to a cholinergic agonist, significantly higher mature elastin content and improved mechanical properties in comparison to the static control. The findings presented here detail an effective approach to engineering elastic human vascular smooth muscle tissue with the functionality necessary for tissue engineering and regenerative medicine applications. Obtaining robust, mature elastic fibers is a key obstacle in tissue-engineered blood vessels. Human induced-pluripotent stem cells have

  2. Defining the steps that lead to cancer: replicative telomere erosion, aneuploidy and an epigenetic maturation arrest of tissue stem cells.

    Science.gov (United States)

    Stindl, Reinhard

    2008-01-01

    Recently, an influential sequencing study found that more than 1700 genes had non-silent mutations in either a breast or colorectal cancer, out of just 11 breast and 11 colorectal tumor samples. This is not surprising given the fact that genomic instability is the hallmark of cancer cells. The plethora of genomic alterations found in every carcinoma does not obey the 'law of genotype-phenotype correlation', since the same histological subtype of cancer harbors different gene mutations and chromosomal aberrations in every patient. In an attempt to make sense out of the observed genetic and chromosomal chaos in cancer, I propose a cascade model. According to this model, tissue regeneration depends on the proliferation and serial activation of stem cells. Replicative telomere erosion limits the proliferative life span of adult stem cells and results in the Hayflick limit (M1). However, local tissue exhaustion or old age might promote the activation of M1-deficient tissue stem cells. Extended proliferation of these cells leads to telomere-driven chromosomal instability and aneuploidy (abnormal balance of chromosomes and/or chromosome material). Several of the aforementioned steps have been already described in the literature. However, in contrast to common theories, it is proposed here that the genomic damage blocks the epigenetic differentiation switch. As a result of aneuploidy, differentiation-specific genes cannot be activated by modification of methylation patterns. Consequently, the phenotype of cancer tissue is largely determined by the epigenetic maturation arrest of tissue stem cells, which in addition enables a fraction of cancer cells to proliferate, invade and metastasize, as normal adult stem cells do. The new model combines genetic and epigenetic alterations of cancer cells in one causative cascade and offers an explanation for why identical histologic cancer types harbor a confusing variety of chromosomal and gene aberrations. The Viennese Cascade, as

  3. Access and Definition: Exploring how STEM Faculty, Department Heads, and University Policy Administrators Navigate the Implementation of a Parental Leave Policy

    OpenAIRE

    Schimpf, Corey T; Santiago, Marisol Mercado; Pawley, Alice L.

    2012-01-01

    Access and Definition: Exploring how STEM Faculty, Department Heads and University Policy Administrators Navigate the Enactment of a Parental Leave Policy A key feature in various reports exploring women’s persisting underrepresentation in STEM faculty positions in the US is the need to disseminate policy information to all stakeholders involved in issues relating to women STEM faculty underrepresentation and retention. Indeed, the National Academies of Science Beyond Barriers and Bias: Fulfi...

  4. Establishment of a Novel Lingual Organoid Culture System: Generation of Organoids Having Mature Keratinized Epithelium from Adult Epithelial Stem Cells

    Science.gov (United States)

    Hisha, Hiroko; Tanaka, Toshihiro; Kanno, Shohei; Tokuyama, Yoko; Komai, Yoshihiro; Ohe, Shuichi; Yanai, Hirotsugu; Omachi, Taichi; Ueno, Hiroo

    2013-11-01

    Despite the strong need for the establishment of a lingual epithelial cell culture system, a simple and convenient culture method has not yet been established. Here, we report the establishment of a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Histological analyses showed that the generated organoids had both a stratified squamous epithelial cell layer and a stratum corneum. Very recently, we showed via a multicolor lineage tracing method that Bmi1-positive stem cells exist at the base of the epithelial basal layer in the interpapillary pit. Using our new culture system, we found that organoids could be generated by single Bmi1-positive stem cells and that in the established organoids, multiple Bmi1-positive stem cells were generated at the outermost layer. Moreover, we observed that organoids harvested at an early point in culture could be engrafted and maturate in the tongue of recipient mice and that the organoids generated from carcinogen-treated mice had an abnormal morphology. Thus, this culture system presents valuable settings for studying not only the regulatory mechanisms of lingual epithelium but also lingual regeneration and carcinogenesis.

  5. Returning to STEM: Gendered Factors Affecting Employability for Mature Women Students

    Science.gov (United States)

    Herman, Clem

    2015-01-01

    This paper adds to current discourses around employability by arguing for an explicit recognition of gender, in particular in relation to women's employment in male-dominated sectors such as science, engineering and technology. This is not limited to young first-time graduates but continues and evolves throughout the life course. Mature women…

  6. A simplified protocol for differentiation of electrophysiologically mature neuronal networks from human induced pluripotent stem cells

    NARCIS (Netherlands)

    N. Gunhanlar (Nilhan); G. Shpak (Guy); M. Van Der Kroeg; L.A. Gouty-Colomer; S.T. Munshi (Shashini T.); B. Lendemeijer (Bert); M. Ghazvini (Mehrnaz); C. Dupont (Claire); W.J.G. Hoogendijk (Witte); J.H. Gribnau (Joost); F.M.S. Vrij (Femke); S.A. Kushner (Steven)

    2017-01-01

    textabstractProgress in elucidating the molecular and cellular pathophysiology of neuropsychiatric disorders has been hindered by the limited availability of living human brain tissue. The emergence of induced pluripotent stem cells (iPSCs) has offered a unique alternative strategy using

  7. Mechanosensitivity of dental pulp stem cells is related to their osteogenic maturity

    NARCIS (Netherlands)

    Kraft, D.C.E.; Bindslev, D.A.; Melsen, B.; Abdallah, B.M.; Kassem, K.; Klein-Nulend, J.

    2010-01-01

    For engineering bone tissue, mechanosensitive cells are needed for bone (re)modelling. Local bone mass and architecture are affected by mechanical loading, which provokes a cellular response via loading-induced interstitial fluid flow. We studied whether human dental pulp-derived mesenchymal stem

  8. Mesenchymal stem cells induce mature dendritic cells into a novel Jagged-2-dependent regulatory dendritic cell population.

    Science.gov (United States)

    Zhang, Bin; Liu, Rui; Shi, Dan; Liu, Xingxia; Chen, Yuan; Dou, Xiaowei; Zhu, Xishan; Lu, Chunhua; Liang, Wei; Liao, Lianming; Zenke, Martin; Zhao, Robert C H

    2009-01-01

    Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2-dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.

  9. Cryptogamic stem covers may contribute to nitrous oxide consumption by mature beech trees

    Czech Academy of Sciences Publication Activity Database

    Macháčová, Kateřina; Maier, M.; Svobodová, Kateřina; Lang, F.; Urban, Otmar

    2017-01-01

    Roč. 7, OCT (2017), č. článku 13243. ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061; GA ČR(CZ) GJ17-18112Y Institutional support: RVO:67179843 Keywords : nitrous oxide * N2O * field conditions * cryptogamic stem Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 4.259, year: 2016

  10. Induced Pluripotent Stem Cell-Derived Neural Cells Survive and Mature in the Nonhuman Primate Brain

    Directory of Open Access Journals (Sweden)

    Marina E. Emborg

    2013-03-01

    Full Text Available The generation of induced pluripotent stem cells (iPSCs opens up the possibility for personalized cell therapy. Here, we show that transplanted autologous rhesus monkey iPSC-derived neural progenitors survive for up to 6 months and differentiate into neurons, astrocytes, and myelinating oligodendrocytes in the brains of MPTP-induced hemiparkinsonian rhesus monkeys with a minimal presence of inflammatory cells and reactive glia. This finding represents a significant step toward personalized regenerative therapies.

  11. Chemical diversity of essential oils from flowers,leaves,and stems of Rhanterium epapposum Oliv. growing in northern border region of Saudi Arabia

    Institute of Scientific and Technical Information of China (English)

    Marwa Awad; Abdelrhman Abdelwahab

    2016-01-01

    Objective:To evaluate the medicinal uses of Rhanterium epapposum Oliv.(R.epapposum) growing in northern border region of Saudi Arabia,through the chemical diversity of essential oils extracted from its flowers,leaves and stems.Methods:Aerial parts of R.epapposum were collected in April 2014.Air dried flowers,leaves,and stems were separately subjected to hydrodistillation in a Clevenger-type apparatus for 4 h to extract the essential oils.Gas chromatography-mass spectrometry analysis of the essential oils was carried out using an Agilent 6890 gas chromatograph equipped with an Agilent 5973 mass spectrometric detector.Results:A total of 51 compounds representing 76.35%–94.86% of flowers,leaves and stems oils composition were identified.The chemical profiles of the studied fractions revealed the dominance of monoterpenes,regardless of qualitative and quantitative differences observed.Limonene,linalool,4-terpineol and a-cadinol represented the major constituents of flowers oil.Leaves oil was dominated by limonene,sabinene,a-pinene and b-myrcene whereas linalool,ionole,a-cadinol,b-eudesmol,4-terpineol,and aterpineol were the major constituents of stems oil.Conclusions:Essential oils from flowers,leaves and stems of R.epapposum growing in northern border region of Saudi Arabia are considered as a rich source of monoterpenes which have biological activities.

  12. Multiple Biological Effects of Olive Oil By-products such as Leaves, Stems, Flowers, Olive Milled Waste, Fruit Pulp, and Seeds of the Olive Plant on Skin.

    Science.gov (United States)

    Kishikawa, Asuka; Ashour, Ahmed; Zhu, Qinchang; Yasuda, Midori; Ishikawa, Hiroya; Shimizu, Kuniyoshi

    2015-06-01

    As olive oil production increases, so does the amount of olive oil by-products, which can cause environmental problems. Thus, new ways to utilize the by-products are needed. In the present study, five bioactive characteristics of olive oil by-products were assessed, namely their antioxidant, anti-bacterial, anti-melanogenesis, anti-allergic, and collagen-production-promoting activities. First, the extracts of leaves (May and October), stems (May and October), flowers, olive milled waste, fruit pulp and seeds were prepared using two safe solvents, ethanol and water. According to HPLC and LC/MS analysis and Folin-Ciocalteu assay, the ethanol extracts of the leaves (May and October), stems (May and October) and flowers contained oleuropein, and the ethanol extract of the stems showed the highest total phenol content. Oleuropein may contribute to the antioxidant and anti-melanogenesis activities of the leaves, stems, and flowers. However, other active compounds or synergistic effects present in the ethanol extracts are also likely to contribute to the anti-bacterial activity of the leaves and flowers, the anti-melanogenesis activity of some parts, the anti-allergic activity of olive milled waste, and the collagen-production-promoting activity of the leaves, stems, olive milled waste and fruit pulp. This study provides evidence that the by-products of olive oil have the potential to be further developed and used in the skin care industry. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Neural stem cells in the immature, but not the mature, subventricular zone respond robustly to traumatic brain injury.

    Science.gov (United States)

    Goodus, Matthew T; Guzman, Alanna M; Calderon, Frances; Jiang, Yuhui; Levison, Steven W

    2015-01-01

    necessarily lead to the production of many new neurons. On the contrary, many BrdU+/doublecortin+ cells were observed streaming out of the SVZ into the neocortex 2 weeks after injuries to P11 rats. However, very few new mature neurons were seen adjacent to the lesion 28 days after injury. Altogether, these data indicate that immature SVZ cells mount a more robust proliferative response to a focal brain injury than adult cells, which includes an expansion of stem cells, primitive progenitors and neuroblasts. Nonetheless, this regenerative response does not result in significant neuronal replacement, indicating that new strategies need to be implemented to retain the regenerated neurons and glia that are being produced. © 2014 S. Karger AG, Basel.

  14. Maturation of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) in 3D collagen matrix: Effects of niche cell supplementation and mechanical stimulation.

    Science.gov (United States)

    Zhang, W; Kong, C W; Tong, M H; Chooi, W H; Huang, N; Li, R A; Chan, B P

    2017-02-01

    Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) are regarded as a promising source for regenerative medicine, drug testing and disease modeling. Nevertheless, cardiomyocytes are immature in terms of their contractile structure, metabolism and electrophysiological properties. Here, we fabricate cardiac muscle strips by encapsulating hESC-CMs in collagen-based biomaterials. Supplementation of niche cells at 3% to the number of hESC-CMs enhance the maturation of the hESC-CMs in 3D tissue matrix. The benefits of adding mesenchymal stem cells (MSCs) are comparable to that of adding fibroblasts. These two cell types demonstrate similar effects in promoting the compaction and cell spreading, as well as expression of maturation markers at both gene and protein levels. Mechanical loading, particularly cyclic stretch, produces engineered cardiac tissues with higher maturity in terms of twitch force, elastic modulus, sarcomere length and molecular signature, when comparing to static stretch or non-stretched controls. The current study demonstrates that the application of niche cells and mechanical stretch both stimulate the maturation of hESC-CMs in 3D architecture. Our results therefore suggest that this 3D model can be used for in vitro cardiac maturation study. Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) are regarded as being a promising source of cells for regenerative medicine, drug testing and disease modeling. Nevertheless, cardiomyocytes are immature in terms of their contractile structure, metabolism and electrophysiological properties. In the current study, we have fabricated cardiac muscle strips by encapsulating hESC-CMs in collagen-based biomaterials and demonstrated that supplementation of mesenchymal niche cells as well as provision of mechanical loading particularly stretching have significantly promoted the maturation of the cardiomyocytes and hence improved the mechanical functional characteristics of the tissue strips

  15. Induced pluripotent stem cell-derived neural cells survive and mature in the nonhuman primate brain.

    Science.gov (United States)

    Emborg, Marina E; Liu, Yan; Xi, Jiajie; Zhang, Xiaoqing; Yin, Yingnan; Lu, Jianfeng; Joers, Valerie; Swanson, Christine; Holden, James E; Zhang, Su-Chun

    2013-03-28

    The generation of induced pluripotent stem cells (iPSCs) opens up the possibility for personalized cell therapy. Here, we show that transplanted autologous rhesus monkey iPSC-derived neural progenitors survive for up to 6 months and differentiate into neurons, astrocytes, and myelinating oligodendrocytes in the brains of MPTP-induced hemiparkinsonian rhesus monkeys with a minimal presence of inflammatory cells and reactive glia. This finding represents a significant step toward personalized regenerative therapies. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  16. How to make a tree ring: Coupling stem water flow and cambial activity in mature Alpine conifers

    Science.gov (United States)

    Peters, Richard L.; Frank, David C.; Treydte, Kerstin; Steppe, Kathy; Kahmen, Ansgar; Fonti, Patrick

    2017-04-01

    Inter-annual tree-ring measurements are used to understand tree-growth responses to climatic variability and reconstruct past climate conditions. In parallel, mechanistic models use experimentally defined plant-atmosphere interactions to explain past growth responses and predict future environmental impact on forest productivity. Yet, substantial inconsistencies within mechanistic model ensembles and mismatches with empirical data indicate that significant progress is still needed to understand the processes occurring at an intra-annual resolution that drive annual growth. However, challenges arise due to i) few datasets describing climatic responses of high-resolution physiological processes over longer time-scales, ii) uncertainties on the main mechanistic process limiting radial stem growth and iii) complex interactions between multiple environmental factors which obscure detection of the main stem growth driver, generating a gap between our understanding of intra- and inter-annual growth mechanisms. We attempt to bridge the gap between inter-annual tree-ring width and sub-daily radial stem-growth and provide a mechanistic perspective on how environmental conditions affect physiological processes that shape tree rings in conifers. We combine sub-hourly sap flow and point dendrometer measurements performed on mature Alpine conifers (Larix decidua) into an individual-based mechanistic tree-growth model to simulate sub-hourly cambial activity. The monitored trees are located along a high elevational transect in the Swiss Alps (Lötschental) to analyse the effect of increasing temperature. The model quantifies internal tree hydraulic pathways that regulate the turgidity within the cambial zone and induce cell enlargement for radial growth. The simulations are validated against intra-annual growth patterns derived from xylogenesis data and anatomical analyses. Our efforts advance the process-based understanding of how climate shapes the annual tree-ring structures

  17. Cellular Components, Including Stem-Like Cells, of Preterm Mother's Mature Milk as Compared with Those in Her Colostrum: A Pilot Study.

    Science.gov (United States)

    Kaingade, Pankaj; Somasundaram, Indumathi; Sharma, Akshita; Patel, Darshan; Marappagounder, Dhanasekaran

    2017-09-01

    Whether the preterm mothers' mature milk retains the same cellular components as those in colostrum including stem-like cell, cell adhesion molecules, and immune cells. A total of five preterm mothers were recruited for the study having an average age of 30.2 years and gestational age of 29.8 weeks from the Pristine Women's Hospital, Kolhapur. Colostrum milk was collected within 2-5 days and matured milk was collected 20-30 days after delivery from the same mothers. Integral cellular components of 22 markers including stem cells, immune cells, and cell adhesion molecules were measured using flowcytometry. Preterm mature milk was found to possess higher expressions of hematopoietic stem cells, mesenchymal stem-like cells, immune cells, few cell adhesion molecules, and side population cells than colostrum. The increased level of these different cell components in mature milk may be important in the long-term preterm baby's health growth. Further similar research in a larger population of various gestational ages and lactation stages of preterm mothers is warranted to support these pilot findings.

  18. Comparison study of moisture content, colour properties and essential oil compounds extracted by hydrodistillation and supercritical fluid extraction between stem and leaves of lemongrass (Cymbopogun citratus)

    Science.gov (United States)

    Kamaruddin, Shazlin; Mustapha, Wan Aida Wan; Haiyee, Zaibunnisa Abdul

    2018-04-01

    The objectives of this study were to compare the properties of moisture content, colour and essential oil compounds between stem and leaves of lemongrass (Cymbopogun citratus). The essential oil was extracted using two different methods which are hydrodistillation and supercritical fluid extraction (SFE). There was no significant difference of moisture content between stem and leaves of lemongrass. The lightness (L) and yellowness (+b) values of the stems were significantly higher (pleaves. The highest yield of essential oil was obtained by extraction using supercritical fluid extraction (SFE) in leaves (˜ 0.7%) by treatment at 1700psi and 50°C. The main compound of extracted essential oil was citral (geranial and neral).

  19. Bioactive metabolite profiles and antimicrobial activity of ethanolic extracts from Muntingia calabura L. leaves and stems

    Directory of Open Access Journals (Sweden)

    William Patrick Cruiz Buhian

    2016-08-01

    Conclusions: M. calabura leaf and stem ethanol extracts are potential sources of antibacterial agents against P. aeruginosa and S. aureus. This study reports for the first time the high degree of antifungal activity of M. calabura ethanolic extract, especially against C. albicans.

  20. [The opportunity to use combined stem cells transplantation for haemopoesis activation in the old and mature laboratory animals under the conditions of ionizing radiation].

    Science.gov (United States)

    Grebnev, D Iu; Maklakova, I Iu; Iastrebov, A P

    2014-01-01

    The objective of this work was to study the influence of combined transplantation of stem cells (multypotent mesenchimal stromal and haemopoetic stem cells) on the haemopoesis of old and mature laboratory animals under the condition of ionizing radiation. The result of the experiment shows that under physiological conditions the combined transplantation brings the erithropoesis activation, under the ionizing radiation conditions it brings the erythroid and granulocytopoesis activation. Moreover the combined MMSC and HSC transplantation gives cytoprotective action on the myeloid tissue due to decrease of cyto genically changed cells in the mature animals under the condition of ionizing radiation, but in the old animals this effect can be seen even under physiological condition. Combined transplantation of MMSC and GSC can be used in the mature and old laboratory animals under the conditions of ionising radiation for the haemopoesis activation.

  1. Neofusicoccum parvum Colonization of the Grapevine Woody Stem Triggers Asynchronous Host Responses at the Site of Infection and in the Leaves

    Directory of Open Access Journals (Sweden)

    Mélanie Massonnet

    2017-06-01

    Full Text Available Grapevine trunk diseases cause important economic losses in vineyards worldwide. Neofusicoccum parvum, one of the most aggressive causal agents of the trunk disease Botryosphaeria dieback, colonizes cells and tissues of the grapevine wood, leading to the formation of an internal canker. Symptoms then extend to distal shoots, with wilting of leaves and bud mortality. Our aim was to characterize the transcriptional dynamics of grapevine genes in the woody stem and in the leaves during Neofusicoccum parvum colonization. Genome-wide transcriptional profiling at seven distinct time points (0, 3, and 24 hours; 2, 6, 8, and 12 weeks showed that both stems and leaves undergo extensive transcriptomic reprogramming in response to infection of the stem. While most intense transcriptional responses were detected in the stems at 24 hours, strong responses were not detected in the leaves until the next sampling point at 2 weeks post-inoculation. Network co-expression analysis identified modules of co-expressed genes common to both organs and showed most of these genes were asynchronously modulated. The temporal shift between stem vs. leaf responses affected transcriptional modulation of genes involved in both signal perception and transduction, as well as downstream biological processes, including oxidative stress, cell wall rearrangement and cell death. Promoter analysis of the genes asynchronously modulated in stem and leaves during N. parvum colonization suggests that the temporal shift of transcriptional reprogramming between the two organs might be due to asynchronous co-regulation by common transcriptional regulators. Topology analysis of stem and leaf co-expression networks pointed to specific transcription factor-encoding genes, including WRKY and MYB, which may be associated with the observed transcriptional responses in the two organs.

  2. Effects of Drying Temperature on Flavonoids Extraction Rate from Young Stems and Leaves of Two Cassava Varieties

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    WANG Ding-mei

    2017-01-01

    Full Text Available To improve flavonoids resources utilization level of young cassava stems and leaves, using cassava varieties SC09 and SC205 as ob jects, investigated the effect of different drying temperatures(40~120℃on the flavonoids extraction rate(FERand their stability in 120 d storage period after drying, explored a right drying storage method for postharvest young cassava stems and leaves. The research showed that total FER rised first, and then fell and rised again with the increase of drying temperature. During 40~80℃, the total FER was obviously in fluenced by variety and temperature, but only temperature was main factor affecting total FER during 90~120℃. Extract degree of flavonoids include rutin, amentoflavone or catechin, kaempferol, hesperidin, quercetin minished in order; the effect of cassava variety on the extraction rate of catechin and hesperidin was greater than that of drying temperature, but that contrary to other 4 flavonoids. Variety and temperature had a maximum impact respectively on catechin and rutin extraction rates. Whereas both of variety and temperature had a minimum impact on kaempferol extraction rate. FER reached higher levels of 1.42%and 1.53% respectively in SC09 after 120℃drying and SC205 after 110℃drying, and had best stability during 120 d storage period. The extraction rate of hesperidin increased after drying storage, and that of other 5 ingredients were changing with different varieties and temperatures; the coefficient variation(CV=1.03%~6.86%of kaempferol was minimum and its stability was best; extraction rates of rutin and kaempferol in SC205 after 110℃drying were maximum, whose increasing rates were 44.89%and 7.27%respectively with a small separate degree(CV were 6.94%, 4.59%and good extraction stability. Maximum in creasing rates of catechin, amentoflavone, quercetin and hesperidin were 211.60%,17.60%,186.39% and 538.08% respectively. However,their stabilities of extraction efficiency were poor

  3. Chemical composition of fatty acid and unsaponifiable fractions of leaves, stems and roots of Arbutus unedo and in vitro antimicrobial activity of unsaponifiable extracts.

    Science.gov (United States)

    Diba, Mohamed Amine; Paolini, Julien; Bendahou, Mourad; Varesi, Laurent; Allali, Hocine; Desjobert, Jean-Marie; Tabti, Boufeldja; Costa, Jean

    2010-07-01

    The chemical composition of the fatty acid and unsaponifiable fractions of the leaves, stems and roots of Arbutus unedo L. were determined using gas chromatography and gas chromatography-mass spectrometry. The fatty acid fractions of the leaves, stems and roots contained 38.5%, 31.3% and 14.1% palmitic acid, respectively, along with other long-chain fatty acids (up to C22). The chemical composition of the unsaponifiable fractions differed: the leaf and stem fractions contained high levels of aliphatic (32.1% and 62.6%, respectively) and terpenic compounds (49.6% and 25.7%, respectively), and the root fraction mainly contained esters, of which the most abundant was benzyl cinnamate (36.6%). The antimicrobial activities of the unsaponifiable fractions against nine species of microorganisms were assessed. The unsaponifiable leaf and stem extracts inhibited the growth of Klebsiella pneumoniae, Enterococcus faecalis and Candida albicans.

  4. Control of the synthesis and subcellular targeting of the two GDH genes products in leaves and stems of Nicotiana plumbaginifolia and Arabidopsis thaliana.

    Science.gov (United States)

    Fontaine, Jean-Xavier; Saladino, Francesca; Agrimonti, Caterina; Bedu, Magali; Tercé-Laforgue, Thérèse; Tétu, Thierry; Hirel, Bertrand; Restivo, Francesco M; Dubois, Frédéric

    2006-03-01

    Although the physiological role of the enzyme glutamate dehydrogenase which catalyses in vitro the reversible amination of 2-oxoglutarate to glutamate remains to be elucidated, it is now well established that in higher plants the enzyme preferentially occurs in the mitochondria of phloem companion cells. The Nicotiana plumbaginifolia and Arabidopis thaliana enzyme is encoded by two distinct genes encoding either an alpha- or a beta-subunit. Using antisense plants and mutants impaired in the expression of either of the two genes, we showed that in leaves and stems both the alpha- and beta-subunits are targeted to the mitochondria of the companion cells. In addition, we found in both species that there is a compensatory mechanism up-regulating the expression of the alpha-subunit in the stems when the expression of the beta-subunit is impaired in the leaves, and of the beta-subunit in the leaves when the expression of the alpha-subunit is impaired in the stems. When one of the two genes encoding glutamate dehydrogenase is ectopically expressed, the corresponding protein is targeted to the mitochondria of both leaf and stem parenchyma cells and its production is increased in the companion cells. These results are discussed in relation to the possible signalling and/or physiological function of the enzyme which appears to be coordinated in leaves and stems.

  5. A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer

    Science.gov (United States)

    Arif, Ibrahim A.; Bakir, Mohammad A.; Khan, Haseeb A.; Ahamed, Anis; Al Farhan, Ahmad H.; Al Homaidan, Ali A.; Al Sadoon, Mohammad; Bahkali, Ali H.; Shobrak, Mohammad

    2010-01-01

    Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae) and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl), polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) with the cetyltrimethylammonium bromide (CTAB) method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M) in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification. PMID:20957085

  6. Quantitative determination of total and individual flavonoids in stems and leaves of Buddleja davidii and Buddleja albiflora.

    Science.gov (United States)

    Ying, Cheng; Wan, Dingrong

    2012-10-01

    Buddleja davidii and B. albiflora are two different original plants of the famous crude medicine "Diaoyangchen". An ultraviolet-visible spectrophotometric method and a HPLC method were used for the determination of total and individual flavonoids (luteolin and apigenin) contents from their stems and leaves for the first time. From the comparative evaluation, remarkable differences in flavonoids contents were observed between different origins and different parts of the samples. And content of specific flavonoid did not correspond to the total flavonoids contents in Buddleja davidii and Buddleja albiflora. With a better accuracy and precision, the methods had been proved simple, rapid, and reliable for quantitative determination of the total flavonoids and luteolin and apigenin in the two phytomedicines. Furthermore, our present study will pave the way of guidelines for the differentiation and standardization and exploitation of individual parts of this herb material.

  7. Thin layer chromatography fingerprint, antioxidant, and antibacterial activities of rhizomes, stems, and leaves of Curcuma aeruginosa Roxb.

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    Safitri, A.; Batubara, I.; Khumaida, N.

    2017-05-01

    Fingerprints of 5 temu hitam (Curcuma aeruginosa Roxb.) accessions (Malang, Cirebon, Kuningan 1, Bogor, and Liwa) were determined by thin-layer chromatography (TLC) and compared to fingerprints of turmeric (Curcuma longa L), temu putih (Curcuma zedoaria (Christm.) Roscoe), and temu lawak (Curcuma zanthorriza Roxb.). Maceration method with ethanol as the solvent was used for extraction. The eluent used for fingerprint by TLC was chloroform:dichloromethane (9:1v/v). Five accessions of temu hitam show similar fingerprint patterns, but different in band thickness. Temu hitam rhizomes have bands of curcuminoid (Rf 0.22, 0.10, 0.03), and characteristic bands of Rf 0.42, 0.27, and 0.77, which can be distinguished from turmeric and temu lawak and Rf 0.13, which is different from temu putih. Leaves and stems of temu hitam can be distinguished from temu putih, turmeric, and temu lawak at Rf 0.60. Rhizomes of all plants reveal strong antibacterial activity against Staphylococcus aureus and antioxidant activity on DPPH radicals than its corresponding stems and leaves. Antibacterial and antioxidant activities were determined by microdilution and TLC-bioautography. Antibacterial activity of rhizomes of Cirebon and Kuningan 1 accessions are higher than that of other accessions (MIC = 250 μg/mL MBC = 500 μg/mL, but lower as compared to that of temu lawak (MIC = 62.5 μg/mL, MBC = 250 μg/mL) and tetracycline (MIC = MBC = 15.63 μg/mL). Rhizome of Liwa accession exhibits the highest antioxidant activity (IC50 = 124.88 μg/mL) amongst all accessions, but lower than that of temu lawak (IC50 = 18.45 μg/mL), turmeric (IC50 = 18.82 μg/mL), and temu putih (IC50 = 94.35 μg/mL).

  8. In vitro antileishmanial and cytotoxicity activities of essential oils from Haplophyllum tuberculatum A. Juss leaves, stems and aerial parts.

    Science.gov (United States)

    Hamdi, Assia; Bero, Joanne; Beaufay, Claire; Flamini, Guido; Marzouk, Zohra; Vander Heyden, Yvan; Quetin-Leclercq, Joelle

    2018-02-14

    Plants used for traditional medicine produce diverse and complex secondary metabolites exhibiting various medicinal properties. The medicinal plant Haplophyllum tuberculatum is used by native people against malaria and parasitic infections. In this study and in order to contribute for the search of new natural drugs for leishmaniasis, the essential oils of H. tuberculatum leaves, stems and aerial parts (leaves+stems) collected in two different periods, 2013 and 2015, and their components by GC/FID and GC/MS analyses were investigated. Those collected in 2013 were also re-analyzed two years later. The extracted oils were screened in vitro for anti-leishmanial activity on Leishmania mexicana mexicana (L.m.m.) promastigotes and cytotoxicity on the Chinese Hamster Ovary (CHO) cell line. Limonene (1.5 - 8%), its isomers (R- (+)-limonene and S-(-)-limonene), linalool and octanol were also tested. Results showed that the chemical composition varied according to the year of collection. Though major compounds remain almost the same, qualitative and quantitative variations in the composition of the EOs can be observed between the two years of collection, with some minor compounds identified only in one type of samples. Variation in the composition were also observed in the re-analyzed volatile oils, showing stability concerns. The essential oils and R-(+)-limonene showed moderate anti-leishmanial activity. Their IC 50 range from 6.48 to 50.28 μg/ml. Cytotoxicity assays for theses volatile extracts, R- (+)-limonene and S- (-)-limonene on CHO cells showed relatively potent cytotoxicity with a selectivity index <10. Their CC 50 range from 27.79 to 82.56 μg/ml. The findings of the present study demonstrated that H. tuberculatum might not be considered as a natural source for production of new anti-leishmanial agents without further analyzing its eventual in vivo toxicity as well as that of major pure compounds.

  9. In Situ Dark Adaptation Enhances the Efficiency of DNA Extraction from Mature Pin Oak (Quercus palustris Leaves, Facilitating the Identification of Partial Sequences of the 18S rRNA and Isoprene Synthase (IspS Genes

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    Csengele E. Barta

    2017-10-01

    Full Text Available Mature oak (Quercus spp. leaves, although abundantly available during the plants’ developmental cycle, are rarely exploited as viable sources of genomic DNA. These leaves are rich in metabolites difficult to remove during standard DNA purification, interfering with downstream molecular genetics applications. The current work assessed whether in situ dark adaptation, to deplete sugar reserves and inhibit secondary metabolite synthesis could compensate for the difficulties encountered when isolating DNA from mature leaves rich in secondary metabolites. We optimized a rapid, commercial kit based method to extract genomic DNA from dark- and light-adapted leaves. We demonstrated that in situ dark adaptation increases the yield and quality of genomic DNA obtained from mature oak leaves, yielding templates of sufficiently high quality for direct downstream applications, such as PCR amplification and gene identification. The quality of templates isolated from dark-adapted pin oak leaves particularly improved the amplification of larger fragments in our experiments. From DNA extracts prepared with our optimized method, we identified for the first time partial segments of the genes encoding 18S rRNA and isoprene synthase (IspS from pin oak (Quercus palustris, whose full genome has not yet been sequenced.

  10. Tri-iodo-l-thyronine promotes the maturation of human cardiomyocytes-derived from induced pluripotent stem cells.

    Science.gov (United States)

    Yang, Xiulan; Rodriguez, Marita; Pabon, Lil; Fischer, Karin A; Reinecke, Hans; Regnier, Michael; Sniadecki, Nathan J; Ruohola-Baker, Hannele; Murry, Charles E

    2014-07-01

    Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) have great potential as a cell source for therapeutic applications such as regenerative medicine, disease modeling, drug screening, and toxicity testing. This potential is limited, however, by the immature state of the cardiomyocytes acquired using current protocols. Tri-iodo-l-thyronine (T3) is a growth hormone that is essential for optimal heart growth. In this study, we investigated the effect of T3 on hiPSC-CM maturation. A one-week treatment with T3 increased cardiomyocyte size, anisotropy, and sarcomere length. T3 treatment was associated with reduced cell cycle activity, manifest as reduced DNA synthesis and increased expression of the cyclin-dependent kinase inhibitor p21. Contractile force analyses were performed on individual cardiomyocytes using arrays of microposts, revealing an almost two-fold higher force per-beat after T3 treatment and also an enhancement in contractile kinetics. This improvement in force generation was accompanied by an increase in rates of calcium release and reuptake, along with a significant increase in sarcoendoplasmic reticulum ATPase expression. Finally, although mitochondrial genomes were not numerically increased, extracellular flux analysis showed a significant increase in maximal mitochondrial respiratory capacity and respiratory reserve capability after T3 treatment. Using a broad spectrum of morphological, molecular, and functional parameters, we conclude that T3 is a driver for hiPSC-CM maturation. T3 treatment may enhance the utility of hiPSC-CMs for therapy, disease modeling, or drug/toxicity screens. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Maturation and function of human embryonic stem cell-derived pancreatic progenitors in macroencapsulation devices following transplant into mice.

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    Bruin, Jennifer E; Rezania, Alireza; Xu, Jean; Narayan, Kavitha; Fox, Jessica K; O'Neil, John J; Kieffer, Timothy J

    2013-09-01

    Islet transplantation is a promising cell therapy for patients with diabetes, but it is currently limited by the reliance upon cadaveric donor tissue. We previously demonstrated that human embryonic stem cell (hESC)-derived pancreatic progenitor cells matured under the kidney capsule in a mouse model of diabetes into glucose-responsive insulin-secreting cells capable of reversing diabetes. However, the formation of cells resembling bone and cartilage was a major limitation of that study. Therefore, we developed an improved differentiation protocol that aimed to prevent the formation of off-target mesoderm tissue following transplantation. We also examined how variation within the complex host environment influenced the development of pancreatic progenitors in vivo. The hESCs were differentiated for 14 days into pancreatic progenitor cells and transplanted either under the kidney capsule or within Theracyte (TheraCyte, Laguna Hills, CA, USA) devices into diabetic mice. Our revised differentiation protocol successfully eliminated the formation of non-endodermal cell populations in 99% of transplanted mice and generated grafts containing >80% endocrine cells. Progenitor cells developed efficiently into pancreatic endocrine tissue within macroencapsulation devices, despite lacking direct contact with the host environment, and reversed diabetes within 3 months. The preparation of cell aggregates pre-transplant was critical for the formation of insulin-producing cells in vivo and endocrine cell development was accelerated within a diabetic host environment compared with healthy mice. Neither insulin nor exendin-4 therapy post-transplant affected the maturation of macroencapsulated cells. Efficient differentiation of hESC-derived pancreatic endocrine cells can occur in a macroencapsulation device, yielding glucose-responsive insulin-producing cells capable of reversing diabetes.

  12. Coculturing with endothelial cells promotes in vitro maturation and electrical coupling of human embryonic stem cell-derived cardiomyocytes.

    Science.gov (United States)

    Pasquier, Jennifer; Gupta, Renuka; Rioult, Damien; Hoarau-Véchot, Jessica; Courjaret, Raphael; Machaca, Khaled; Al Suwaidi, Jassim; Stanley, Edouard G; Rafii, Shahin; Elliott, David A; Abi Khalil, Charbel; Rafii, Arash

    2017-06-01

    Pluripotent human embryonic stem cells (hESC) are a promising source of repopulating cardiomyocytes. We hypothesized that we could improve maturation of cardiomyocytes and facilitate electrical interconnections by creating a model that more closely resembles heart tissue; that is, containing both endothelial cells (ECs) and cardiomyocytes. We induced cardiomyocyte differentiation in the coculture of an hESC line expressing the cardiac reporter NKX2.5-green fluorescent protein (GFP), and an Akt-activated EC line (E4 + ECs). We quantified spontaneous beating rates, synchrony, and coordination between different cardiomyocyte clusters using confocal imaging of Fura Red-detected calcium transients and computer-assisted image analysis. After 8 days in culture, 94% ± 6% of the NKX2-5GFP + cells were beating when hESCs embryonic bodies were plated on E4 + ECs compared with 34% ± 12.9% for controls consisting of hESCs cultured on BD Matrigel (BD Biosciences) without ECs at Day 11 in culture. The spatial organization of beating areas in cocultures was different. The GFP + cardiomyocytes were close to the E4 + ECs. The average beats/min of the cardiomyocytes in coculture was faster and closer to physiologic heart rates compared with controls (50 ± 14 [n = 13] vs 25 ± 9 [n = 8]; p < 0.05). The coculture with ECs led to synchronized beating relying on the endothelial network, as illustrated by the loss of synchronization upon the disruption of endothelial bridges. The coculturing of differentiating cardiomyocytes with Akt-activated ECs but not EC-conditioned media results in (1) improved efficiency of the cardiomyocyte differentiation protocol and (2) increased maturity leading to better intercellular coupling with improved chronotropy and synchrony. Copyright © 2017. Published by Elsevier Inc.

  13. Phytochemical and pharmacological variability in Golden Thistle functional parts: comparative study of roots, stems, leaves and flowers.

    Science.gov (United States)

    Marmouzi, Ilias; El Karbane, Miloud; El Hamdani, Maha; Kharbach, Mourad; Naceiri Mrabti, Hanae; Alami, Rachid; Dahraoui, Souhail; El Jemli, Meryem; Ouzzif, Zhor; Cherrah, Yahia; Derraji, Soufiane; Faouzi, My El Abbes

    2017-11-01

    Scolymus hispanicus or the Golden Thistle, locally known as 'Guernina' or 'Taghediwt', is one of the most appreciated wild vegetables in Morocco. This study aims to characterise the functional chemical and pharmacological variability of Scolymus hispanicus parts (roots, stems, leaves and flowers). The chemical analysis revealed higher content of α-tocopherol in the flowers (2.79 ± 0.07 mg/100 g) and lead to the identification of 3 flavonoids and 13 phenolic acids, with high content of gallic acid in leaves (187.01 ± 10.19 mg/kg); chlorogenic (936.18 ± 92.66 mg/kg) and caffeic (4400.14 ± 191.43 mg/kg) acids in flowers, roots were much more higher in sinapic acid (0.25 ± 0.03 mg/kg) compared to the other parts. Moreover, Scolymus hispanicus ethanolic extracts exhibited interesting antioxidant and antimicrobial properties, promising anti-amylase and anti-glucosidase activities and relevant diuretic effect that confirms its traditional uses.

  14. Alterations in carbon and nitrogen metabolism induced by water deficit in the stems and leaves of Lupinus albus L.

    Science.gov (United States)

    Pinheiro, C; Chaves, M M; Ricardo, C P

    2001-05-01

    Water deficit (WD) in Lupinus albus L. brings about tissue-specific responses that are dependent on stress intensity. Carbohydrate metabolism is very sensitive to changes in plant water status. Six days from withholding water (DAW), sucrose, glucose and fructose levels of the leaf blade had already increased over 5-fold, and the activities of SS and INV(A) had increased c. 1.5-2 times. From 9 DAW on, when stress intensity was more pronounced, these effects were reversed with fructose and glucose concentrations as well as INV(A) activity dropping in parallel. The stem (specifically the stele) responded to the stress intensification with striking increases in the concentration of sugars, N and S, and in the induction of thaumatin-like-protein and an increase in chitinase and peroxidase. At 13 DAW, the plants lost most of the leaves but on rewatering they fully recovered. Thus, the observed changes appear to contribute to a general mechanism of survival under drought, the stem playing a key role in that process.

  15. Human embryonic stem cell derived islet progenitors mature inside an encapsulation device without evidence of increased biomass or cell escape.

    Science.gov (United States)

    Kirk, Kaitlyn; Hao, Ergeng; Lahmy, Reyhaneh; Itkin-Ansari, Pamela

    2014-05-01

    There are several challenges to successful implementation of a cell therapy for insulin dependent diabetes derived from human embryonic stem cells (hESC). Among these are development of functional insulin producing cells, a clinical delivery method that eliminates the need for chronic immunosuppression, and assurance that hESC derived tumors do not form in the patient. We and others have shown that encapsulation of cells in a bilaminar device (TheraCyte) provides immunoprotection in rodents and primates. Here we monitored human insulin secretion and employed bioluminescent imaging (BLI) to evaluate the maturation, growth, and containment of encapsulated islet progenitors derived from CyT49 hESC, transplanted into mice. Human insulin was detectable by 7 weeks post-transplant and increased 17-fold over the course of 8 weeks, yet during this period the biomass of encapsulated cells remained constant. Remarkably, by 20 weeks post-transplant encapsulated cells secreted sufficient levels of human insulin to ameliorate alloxan induced diabetes. Further, bioluminescent imaging revealed for the first time that hESCs remained fully contained in encapsulation devices for up to 150 days, the longest period tested. Collectively, the data suggest that encapsulated hESC derived islet progenitors hold great promise as an effective and safe cell replacement therapy for insulin dependent diabetes. Copyright © 2014. Published by Elsevier B.V.

  16. Mesenchymal Stem Cell-Conditioned Medium Modulates Apoptotic and Stress-Related Gene Expression, Ameliorates Maturation and Allows for the Development of Immature Human Oocytes after Artificial Activation

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    Hakimeh Akbari

    2017-12-01

    Full Text Available The aim of the present study was to determine whether mesenchymal stem cell-conditioned medium (MSC-CM modulates apoptotic and stress-related gene expression, and ameliorates maturation and developmental potential of immature human oocytes after artificial activation. A total of 247 surplus immature germinal vesicle (GV oocytes obtained from infertile women were allocated into two in vitro maturation (IVM groups: 1: GV oocytes (n = 116 matured in vitro (fIVM, and 2: GV oocytes (n = 131 that were vitrified, then in vitro matured (vIVM. Also, two maturation media were used: Alpha-minimum essential medium (α-MEM and human umbilical cord-derived MSCs (hUCM. After 36 h of incubation, the IVM oocytes were examined for nuclear maturation. In IVM-matured oocytes, cytoplasmic maturation was evaluated after artificial activation through Ionomycin. Moreover, the quantitative expressions of B-cell CLL/lymphoma 2 (BCL2, BCL2-associated X protein (BAX, superoxide dismutase (SOD, and Heat shock proteins (HSP70 in matured oocytes were assessed by quantitative Real-time polymerase chain reaction (qRT-PCR and compared with fresh and vitrified in vivo matured oocytes, which were used as fIVM and vIVM controls, respectively. The highest maturation rate was found in hUCM in fIVM, and the lowest maturation rate was found using α-MEM in vIVM (85.18% and 71.42%, respectively. The cleavage rate in fIVM was higher than that in vIVM (83.4% vs. 72.0%. In addition, the cleavage rate in α-MEM was lower than that in the hUCM (66.0% vs. 89.4%. Furthermore, the difference between parthenote embryo arrested in 4–8 cells (p < 0.04 and the quality of embryo arrested in 8-cell (p < 0.007 were significant. The developmental stages of parthenote embryos in hUCM versus α-MEM were as follows: 2–4 cell (89.45% vs. 66.00%, respectively, 4–8 cell (44.31% vs. 29.11%, respectively, morula (12.27% vs. 2.63%, respectively, and blastocysts (2.5% vs. 0%, respectively. The messenger

  17. Potential nutritional and antioxidant activity of various solvent extracts from leaves and stem bark of Anisophyllea laurina R. Br ex Sabine used in folk medicine

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    Gbago Onivogui

    2017-07-01

    Full Text Available ABSTRACT Anisophyllea laurina is a plant that has been used in folk medicine to treat malaria, dysentery, diabetes, toothache and various skin diseases. Leaves extract had protein content of 9.68% and a high calcium content of 25084.317 mg/100 g while stem bark extract was found to contain greater amounts of calcium (8560.96 mg/100 g, potassium (7649.47 mg/100 g, magnesium (1462.49 mg/100 g and iron (973.33 mg/100 g. Palmitic acid, linolenic acid, linoleic acid and oleic acid were the most abundant fatty acids in leaves and stem bark extracts. Furthermore, total phenolic (2382.39 mg GAE /100 g and total flavonoid (385.79 mg QE/100 g contents were abundant in stem bark while leaves extract was rich in total tannin content (3466.63 mg CE/100 g. However, both leaves and stem bark contained great amounts of vitamins and amino acids were a good source of antioxidant activities. For the individual polyphenol, stenophyllanin A (45.87 mg/g, casuarinin (24.55 mg/g and digalloyl-HHDP-glucopyranose isomer (15.63 mg/g were found to be the major compounds from the leaves whereas procyanidin tetramer (14.89 mg/g, (--Epicatechin (12.18 mg/g and procyanidin trimer (11.25 mg/g were the most predominant compounds from the stem bark. Additionally, the results revealed a significant and strong correlation between phenolic compounds and antioxidant activities.

  18. TRANSGENIC GDNF POSITIVELY INFLUENCES PROLIFERATION, DIFFERENTIATION, MATURATION AND SURVIVAL OF MOTOR NEURONS PRODUCED FROM MOUSE EMBRYONIC STEM CELLS.

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    Daniel Édgar Cortés

    2016-09-01

    Full Text Available Embryonic stem cells (ESC are pluripotent and thus can differentiate into every cell type present in the body. Directed differentiation into motor neurons has been described for pluripotent cells. Although neurotrophic factors promote neuronal survival, their role in neuronal commitment is elusive. Here, we developed double-transgenic lines of mouse ESC that constitutively produce Glial cell-derived neurotrophic factor (GDNF and also contain a GFP reporter, driven by HB9, which is expressed only by postmitotic motor neurons. After lentiviral transduction, ESC lines integrated and expressed the human GDNF gene without altering pluripotency markers before differentiation. Further, GDNF-ESC showed significantly higher spontaneous release of this neurotrophin to the medium, when compared to controls. To study motor neuron induction, control and GDNF cell lines were grown as embryoid bodies and stimulated with retinoic acid and Sonic Hedgehog. In GDNF-overexpressing cells, a significant increase of proliferative Olig2+ precursors, which are specified as spinal motor neurons, was found. Accordingly, GDNF increases the yield of cells with the pan motor neuronal markers HB9, monitored by GFP expression, and Isl1. At terminal differentiation, almost all differentiated neurons express phenotypic markers of motor neurons in GDNF cultures, with lower proportions in control cells. To test if the effects of GDNF were present at early differentiation stages, exogenous recombinant human GDNF was added to control ESC, also resulting in enhanced motor neuron differentiation. This effect was abolished by the co-addition of neutralizing anti-GDNF antibodies, strongly suggesting that differentiating ESC are responsive to GDNF. Using the HB9::GFP reporter, motor neurons were selected for electrophysiological recordings. Motor neurons differentiated from GDNF-ESC, compared to control motor neurons, showed greater electrophysiological maturation, characterized by

  19. Evaluation of Antioxidant, Anticholinesterase, and Antidiabetic Potential of Dry Leaves and Stems in Tamarix aphylla Growing Wild in Tunisia.

    Science.gov (United States)

    Mahfoudhi, Adel; Grosso, Clara; Gonçalves, Rui F; Khelifi, Eltaief; Hammami, Saoussen; Achour, Sami; Trabelsi-Ayadi, Malika; Valentão, Patrícia; Andrade, Paula B; Mighri, Zine

    2016-12-01

    Tamarix aphylla (L.) Karst. has a wide geographic distribution and was employed in traditional medicine as astringent, anti-rheumatic and to treat fever. T. aphylla leaves and stems extracts were studied from both chemical and biological points of view to assess the antidiabetic, anticholinesterase and antioxidant potential of this species. The HPLC/Diode Array Detector (DAD) analysis showed the presence of 14 phenolic compounds (gallic, caffeic, p-coumaric, ferulic and ellagic acids, kaempferol, quercetin, quercetin 3-O-galactoside and six flavonol derivatives). This is the first study reporting a comparative study of the biological activities of different extracts from T. aphylla. High activities were obtained against DPPH radical, superoxide anion radical (O2∙-) and nitric oxide radical ( • NO) in a concentration-dependent manner, the most active extracts being the polar ones. T. aphylla also showed moderate protective effects against acetylcholinesterase, but no effects were observed against butyrylcholinesterase. Against α-glucosidase the MeOH extracts displayed IC 50 values from 8.41 to 24.81 μg/ml. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  20. The characteristics of pyrophosphate: D-fructose-6-phosphate 1-phosphotransferases from Sansevieria trifasciata leaves and Phaseolus coccineus stems.

    Science.gov (United States)

    Kowalczyk, S

    1987-01-01

    Three different molecular forms of pyrophosphate-dependent phosphofructokinase have been isolated: one from Sansevieria trifasciata leaves and two from Phaseolus coccineus stems. The form isolated from S. trifasciata has the molecular weight of about 115,000. The apparent molecular weights for the two forms from mung bean were approximately 220,000 and 450,000. All three forms have the same pH optima, an absolute requirement for Mg2+ ions both in the forward and reverse reaction, but differ in their sensitivity toward fructose 2,6-bisphosphate. Kinetic properties of the partially purified enzymes have been investigated in the presence and absence of fructose 2,6-bisphosphate. Pyrophosphate-dependent phosphofructokinase from S. trifasciata exhibited hyperbolic kinetics with all substrates tested. The saturation curves of the enzyme (form A) from mung bean for pyrophosphate, fructose 6-phosphate and fructose 1,6-bisphosphate were sigmoidal in the absence of fructose 2,6-bisphosphate. In the presence of fructose 2,6-bisphosphate these kinetics became hyperbolic.

  1. Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae); Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae)

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    Fernandes, Carromberth Carioca [Universidade Federal do Acre (UFAC), Rio Branco, AC (Brazil). Centro de Ciencias Biologicas e da Natureza; Cursino, Lorena Mayara de Carvalho; Novaes, Jussival de Abreu Pinheiro; Demetrio, Camilla Avelino; Pereira Junior, Orlando Liborio; Nunez, Cecilia Veronica [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Produtos Naturais; Amaral, Ieda Leao do [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Botanica

    2009-07-01

    Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas), of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin), were determined through analyses of NMR 1D ({sup 1}H and {sup 13}C) and NMR 2D (gHSQC and gHMBC). These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae). The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active. (author)

  2. Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae

    Directory of Open Access Journals (Sweden)

    Carromberth Carioca Fernandes

    2009-01-01

    Full Text Available Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas, of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin, were determined through analyses of NMR 1D (¹H and 13C and NMR 2D (gHSQC and gHMBC. These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae. The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active.

  3. Phenolic characterization and variability in leaves, stems and roots of Micro-Tom and patio tomatoes, in response to nitrogen limitation.

    Science.gov (United States)

    Larbat, Romain; Paris, Cédric; Le Bot, Jacques; Adamowicz, Stéphane

    2014-07-01

    Phenolics are implicated in the defence strategies of many plant species rendering their concentration increase of putative practical interest in the field of crop protection. Little attention has been given to the nature, concentration and distribution of phenolics within vegetative organs of tomato (Solanum lycopersicum. L) as compared to fruits. In this study, we extensively characterized the phenolics in leaves, stems and roots of nine tomato cultivars using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-MS(n)) and assessed the impact of low nitrogen (LN) availability on their accumulation. Thirty-one phenolics from the four sub-classes, hydroxycinnamoyl esters, flavonoids, anthocyanins and phenolamides were identified, five of which had not previously been reported in these tomato organs. A higher diversity and concentration of phenolics was found in leaves than in stems and roots. The qualitative distribution of these compounds between plant organs was similar for the nine cultivars with the exception of Micro-Tom because of its significantly higher phenolic concentrations in leaves and stems as compared to roots. With few exceptions, the influence of the LN treatment on the three organs of all cultivars was to increase the concentrations of hydroxycinnamoyl esters, flavonoids and anthocyanins and to decrease those of phenolamides. This impact of LN was greater in roots than in leaves and stems. Nitrogen nutrition thus appears as a means of modulating the concentration and composition of organ phenolics and their distribution within the whole plant. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Eucalyptus oleosa Essential Oils: Chemical Composition and Antimicrobial and Antioxidant Activities of the Oils from Different Plant Parts (Stems, Leaves, Flowers and Fruits

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    Mohamed Larbi Khouja

    2011-02-01

    Full Text Available Essential oils obtained by hydrodistillation from the different parts (stems, adult leaves, immature flowers and fruits of Eucalyptus oleosa were screened for their antioxidant and antimicrobial properties and their chemical composition. According to GC-FID and GC-MS, the principal compound of the stem, immature flowers and the fruit oils was 1,8-cineole, representing 31.5%, 47.0% and 29.1%, respectively. Spathulenol (16.1% and γ-eudesmol (15.0% were the two principal compounds of adult leaves oil. In the DPPH (1,1-diphenyl-2-picrylhydrazyl assay, the oils of the four parts showed moderate antioxidant activity. In the ABTS (2,2’-azinobis-3-ethylbenzothiazoline-6-sulphonate assay, the most active part was the adult leaves, with a IC50 value 13.0 ± 0.6 mg/L, followed by stems (IC50 = 43.5 ± 1.4 mg/L. The essential oils showed a better antibacterial activity against Gram-positive and Gram-negative bacteria, and a significant antifungal activity also was observed against yeast-like fungi. A strong correlations between oxygenated monoterpenes and antimicrobial activity (especially 1,8-cineole were noted (R2 = 0.99, 0.97 and 0.79 for B. subtilis, P. aeruginosa and C. albicans, respectively.

  5. Optimization, Purification, and Starch Stain Wash Application of Two New α-Amylases Extracted from Leaves and Stems of Pergularia tomentosa

    Directory of Open Access Journals (Sweden)

    Imen Lahmar

    2017-01-01

    Full Text Available A continuous research is attempted to fulfil the highest industrial demands of natural amylases presenting special properties. New α-amylases extracted from stems and leaves of Pergularia tomentosa, which is widespread and growing spontaneously in Tunisia, were studied by the means of their activities optimization and purification. Some similarities were recorded for the two identified enzymes: (i the highest amylase activity showed a promoted thermal stability at 50°C; (ii the starch substrate at 1% enhanced the enzyme activity; (iii the two α-amylases seem to be calcium-independent; (iv Zn2+, Cu2+, and Ag2+ were considered as important inhibitors of the enzyme activity. Following the increased gradient of elution on Mono Q-Sepharose column, an increase in the specific activity of 11.82-fold and 10.92-fold was recorded, respectively, for leaves and stems with the presence of different peaks on the purification profiles. Pergularia amylases activities were stable and compatible with the tested commercial detergents. The combination of plant amylase and detergent allowed us to enhance the wash performance with an increase of 35.24 and 42.56%, respectively, for stems and leaves amylases. Characterized amylases were reported to have a promoted potential for their implication notably in detergent industry as well as biotechnological sector.

  6. Neural stem cells and neuro/gliogenesis in the central nervous system: understanding the structural and functional plasticity of the developing, mature, and diseased brain.

    Science.gov (United States)

    Yamaguchi, Masahiro; Seki, Tatsunori; Imayoshi, Itaru; Tamamaki, Nobuaki; Hayashi, Yoshitaka; Tatebayashi, Yoshitaka; Hitoshi, Seiji

    2016-05-01

    Neurons and glia in the central nervous system (CNS) originate from neural stem cells (NSCs). Knowledge of the mechanisms of neuro/gliogenesis from NSCs is fundamental to our understanding of how complex brain architecture and function develop. NSCs are present not only in the developing brain but also in the mature brain in adults. Adult neurogenesis likely provides remarkable plasticity to the mature brain. In addition, recent progress in basic research in mental disorders suggests an etiological link with impaired neuro/gliogenesis in particular brain regions. Here, we review the recent progress and discuss future directions in stem cell and neuro/gliogenesis biology by introducing several topics presented at a joint meeting of the Japanese Association of Anatomists and the Physiological Society of Japan in 2015. Collectively, these topics indicated that neuro/gliogenesis from NSCs is a common event occurring in many brain regions at various ages in animals. Given that significant structural and functional changes in cells and neural networks are accompanied by neuro/gliogenesis from NSCs and the integration of newly generated cells into the network, stem cell and neuro/gliogenesis biology provides a good platform from which to develop an integrated understanding of the structural and functional plasticity that underlies the development of the CNS, its remodeling in adulthood, and the recovery from diseases that affect it.

  7. Water dynamics in mango (Mangifera indica L.) fruit during the young and mature fruit seasons as measured by the stem heat balance method

    International Nuclear Information System (INIS)

    Higuchi, H.; Sakuratani, T.

    2006-01-01

    Water flows in the stem and peduncle of mango fruit were monitored, and the surface transpiration from the fruit was measured during the fruit-growing season. The stem heat balance method was used on the peduncle to monitor the inward water flow during the nighttime, and the reverse water flow from the fruit during the daytime when the stem transpiration water flow increased. This diurnal fluctuation pattern in the water flow was more evident in mature fruit than in young fruit. In mature fruit, the daily water loss due to the reverse flow was estimated to be 3% of the fruit weight. The reverse flow water loss and transpired water loss were compensated for by nocturnal inward water flow, through the peduncle, of 30 g over 15 h. These results were well supported by measurements of fruit dimensions, which indicated a circadian rhythm of contraction and expansion. The reverse flow amounted to 80% of the water loss from the daytime contraction of the fruit, a much greater proportion than the fruit surface transpiration

  8. Studies on the antidiabetic effects of Mangifera indica stem-barks and leaves on nondiabetic, type 1 and type 2 diabetic model rats

    Directory of Open Access Journals (Sweden)

    Amrita Bhowmik

    2009-06-01

    Full Text Available Mangifera indica Linn, locally known as mango tree has been claimed to possess antidiabetic properties by many investigators. The present study was undertaken to screen the hypo- and antihyperglycemic activity of both ethanol and water extracts of leaves and stem-barks of M. indica in nondiabetic and diabetic model rats in different prandial states. The results showed that all of the extracts had significant antihyperglycemic effect in type 2 model rats when fed simultaneously with glucose load (p< 0.05-0.01; p< 0.005-0.001. Moreover, the ethanol extract of stem-barks showed significant antihyperglycemic effect when the extract was fed 30 min prior to the glucose load (p< 0.01. Investigations were carried out to evaluate the effect of M. indica on glucose absorption using a rat intestinal preparation in situ. The ethanol extracts of stem-barks reduced glucose absorption gradually during the whole perfusion period in type 2 rats.

  9. A novel culture method reveals unique neural stem/progenitors in mature porcine iris tissues that differentiate into neuronal and rod photoreceptor-like cells.

    Science.gov (United States)

    Royall, Lars N; Lea, Daniel; Matsushita, Tamami; Takeda, Taka-Aki; Taketani, Shigeru; Araki, Masasuke

    2017-11-15

    Iris neural stem/progenitor cells from mature porcine eyes were investigated using a new protocol for tissue culture, which consists of dispase treatment and Matrigel embedding. We used a number of culture conditions and found an intense differentiation of neuronal cells from both the iris pigmented epithelial (IPE) cells and the stroma tissue cells. Rod photoreceptor-like cells were also observed but mostly in a later stage of culture. Neuronal differentiation does not require any additives such as fetal bovine serum or FGF2, although FGF2 and IGF2 appeared to promote neural differentiation in the IPE cultures. Furthermore, the stroma-derived cells were able to be maintained in vitro indefinitely. The evolutionary similarity between humans and domestic pigs highlight the potential for this methodology in the modeling of human diseases and characterizing human ocular stem cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Composition of the essential oil constituents from leaves and stems of Korean Coriandrum sativum and their immunotoxicity activity on the Aedes aegypti L.

    Science.gov (United States)

    Chung, Ill-Min; Ahmad, Ateeque; Kim, Sun-Jin; Naik, Poornanand Madhava; Nagella, Praveen

    2012-02-01

    The leaves and stems of Coriandrum sativum were extracted and the essential oil composition and immunotoxicity effects were studied. The analyses were conducted by gas chromatography-mass spectroscopy (GC-MS), which revealed the essential oils of C. sativum leaves and stems. Thirty-nine components representing 99.62% of the total oil were identified from the leaves. The major components are cyclododecanol (23.11%), tetradecanal (17.86%), 2-dodecenal (9.93%), 1-decanol (7.24%), 13-tetradecenal (6.85%), 1-dodecanol (6.54%), dodecanal (5.16%), 1-undecanol (2.28%), and decanal (2.33%). Thirty-eight components representing 98.46% of the total oil were identified from the stems of the coriander. The major components are phytol (61.86%), 15-methyltricyclo[6.5.2(13,14),0(7,15)]-pentadeca-1,3,5,7,9,11,13-heptene (7.01%), dodecanal (3.18%), and 1-dodecanol (2.47%). The leaf oil had significant toxic effects against the larvae of Aedes aegypti with an LC₅₀ value of 26.93 ppm and an LC₉₀ value of 37.69 ppm and the stem oil has toxic effects against the larvae of A. aegypti with an LC₅₀ value of 29.39 ppm and an LC₉₀ value of 39.95 ppm. Also, the above data indicate that the major compounds may play an important role in the toxicity of essential oils.

  11. Evaluation of the larvicidal efficiency of stem, roots and leaves of the weed, Parthenium hysterophorus (Family: Asteraceae against Aedes aegypti L.

    Directory of Open Access Journals (Sweden)

    Sarita Kumar

    2012-10-01

    Full Text Available Objective: To assess the larvicidal potential of various extracts prepared from the stem, roots and leaves of Parthenium hysterophorus (P. hysterophorus against 3rd and 4th instars of Aedes aegypti (Ae. aegypti. Methods: The extracts from each part were prepared with four solvents; petroleum ether, hexane, acetone and diethyl ether. Each part was dried, powdered and soaked in different solvents, separately, for five days. The crude extracts thus formed were concentrated using rotary evaporator and stored as stock solution of 1 000 mg/L. Results: All the extracts prepared from the leaves were found ineffective against both the instars causing only 10%-40% mortality. Against 3rd instars, the hexane and petroleum ether extracts prepared from the stem of P. hysterophorus were found effective exhibiting LC50 values of 379.76 and 438.57 mg/L, respectively. Likewise the hexane and petroleum ether extracts from the Parthenium roots resulted in LC50 values of 432.38 and 562.50 mg/L, respectively, against 4th instars of Ae. aegypti revealing their larvicidal potential. It was further found that the hexane extracts, whether from roots or stem, were 13-28% more effective than the petroleum ether extracts. The qualitative phytochemical study of the effective extracts from the stems and roots showed the presence of alkaloids, saponins, terpenoids and flavonoids in different combinations. Conclusions: Our investigations demonstrated the potential of P. hysterophorus roots and stems against Ae. aegypti larvae and their benefits as new types of mosquito larvicides. Variety of types and levels of active constituents in each kind of extract may be responsible for the variability in their potential against Ae. aegypti. Further research is needed to identify these components.

  12. In vitro antioxidant activity, phenolic compounds and protective effect against DNA damage provided by leaves, stems and flowers of Portulaca oleracea (Purslane).

    Science.gov (United States)

    Silva, Rúben; Carvalho, Isabel S

    2014-01-01

    This study analyzed the antioxidant properties of Portulaca oleracea L., known as purslane. The samples (leaves, flowers and stems) were collected at two different locations in Portugal: Tavira (L1) and Vendas Novas (L2). Assays for total antioxidant activity, total phenolic content and ferric-reducing antioxidant power were conducted and, for both locations, significantly higher values (P < 0.05) were observed for stems (508.8 and 982.3 mg AAE/100 g DW, 1008.6 and 2285.5 mg GAE/100 g DW, 121.0 and 166.3 mg TE/100 g DW, respectively for each location), than in leaves or flowers. In the DPPH assay, the three-plant parts from L2 reached the 50% inhibition rate in lower concentrations than plants from L1. On the other hand, higher concentrations of total monomeric anthocyanins were found in samples from L1 (95.5, 88.8 and 86.0 mg/L) than in samples from L2 (81.7, 70.5 and 59.8 mg/L). The same was true for phenolic acids, estimated by liquid-chromatography, where methanol extracts were used. Phenolic extracts from all three-plant parts from both locations showed protective effects on DNA against hydroxyl radicals. This work suggests the possibility of benefit to human health from its consumption, related to the high antioxidant activity of purslane, even the stems, usually discarded in daily consumption.

  13. Translocation of radiocesium from stems and leaves of plants and the effect on radiocesium concentrations in newly emerged plant tissues

    International Nuclear Information System (INIS)

    Tagami, Keiko; Uchida, Shigeo; Ishii, Nobuyoshi; Kagiya, Shigeo

    2012-01-01

    An accident occurred at the Fukushima Dai-ichi Nuclear Power Plant in March 2011 at which time large amounts of radionuclides were released into the atmosphere and the sea. In early May 2011, it was found that newly emerged tea (Camellia sinensis) leaves contained radiocesium, both 134 Cs and 137 Cs in some areas more than 300 km away from the Fukushima plant. To understand the mechanisms of radiocesium transfer to newly emerged tissues (shoots, leaves and fruits) of other plants in the future, radiocesium concentrations in newly emerged leaves of 14 plant species collected from the sampling areas in and near National Institute of Radiological Sciences in Chiba, Japan. The studied plant types were: (1) herbaceous plants, (2) woody plants with no old leaves at the time of the March accident, and (3) woody plants with old leaves out before the accident. About 40–50 d after the start of the accident, newly emerged leaves from woody plant with old leaves tended to show higher values than other woody or herbaceous plants. Concentrations of radiocesium in newly emerged tissues of trees decreased with time, but they did not decrease to the level of herbaceous plants. The type of the plant and presence of old leaves at the time of the heavy deposition period affected the radiocesium concentrations in newly emerged tissues.

  14. Human mesenchymal stem cells cultured on silk hydrogels with variable stiffness and growth factor differentiate into mature smooth muscle cell phenotype.

    Science.gov (United States)

    Floren, Michael; Bonani, Walter; Dharmarajan, Anirudh; Motta, Antonella; Migliaresi, Claudio; Tan, Wei

    2016-02-01

    Cell-matrix and cell-biomolecule interactions play critical roles in a diversity of biological events including cell adhesion, growth, differentiation, and apoptosis. Evidence suggests that a concise crosstalk of these environmental factors may be required to direct stem cell differentiation toward matured cell type and function. However, the culmination of these complex interactions to direct stem cells into highly specific phenotypes in vitro is still widely unknown, particularly in the context of implantable biomaterials. In this study, we utilized tunable hydrogels based on a simple high pressure CO2 method and silk fibroin (SF) the structural protein of Bombyx mori silk fibers. Modification of SF protein starting water solution concentration results in hydrogels of variable stiffness while retaining key structural parameters such as matrix pore size and β-sheet crystallinity. To further resolve the complex crosstalk of chemical signals with matrix properties, we chose to investigate the role of 3D hydrogel stiffness and transforming growth factor (TGF-β1), with the aim of correlating the effects on the vascular commitment of human mesenchymal stem cells. Our data revealed the potential to upregulate matured vascular smooth muscle cell phenotype (myosin heavy chain expression) of hMSCs by employing appropriate matrix stiffness and growth factor (within 72h). Overall, our observations suggest that chemical and physical stimuli within the cellular microenvironment are tightly coupled systems involved in the fate decisions of hMSCs. The production of tunable scaffold materials that are biocompatible and further specialized to mimic tissue-specific niche environments will be of considerable value to future tissue engineering platforms. This article investigates the role of silk fibroin hydrogel stiffness and transforming growth factor (TGF-β1), with the aim of correlating the effects on the vascular commitment of human mesenchymal stem cells. Specifically, we

  15. Resveratrol Ameliorates the Maturation Process of β-Cell-Like Cells Obtained from an Optimized Differentiation Protocol of Human Embryonic Stem Cells

    Science.gov (United States)

    Pezzolla, Daniela; López-Beas, Javier; Lachaud, Christian C.; Domínguez-Rodríguez, Alejandro; Smani, Tarik; Hmadcha, Abdelkrim; Soria, Bernat

    2015-01-01

    Human embryonic stem cells (hESCs) retain the extraordinary capacity to differentiate into different cell types of an adult organism, including pancreatic β-cells. For this particular lineage, although a lot of effort has been made in the last ten years to achieve an efficient and reproducible differentiation protocol, it was not until recently that this aim was roughly accomplished. Besides, several studies evidenced the impact of resveratrol (RSV) on insulin secretion, even though the mechanism by which this polyphenol potentiates glucose-stimulated insulin secretion (GSIS) is still not clear. The aim of this study was to optimize an efficient differentiation protocol that mimics in vivo pancreatic organogenesis and to investigate whether RSV may improve the final maturation step to obtain functional insulin-secreting cells. Our results indicate that treatment of hESCs (HS-181) with activin-A induced definitive endoderm differentiation as detected by the expression of SOX17 and FOXA2. Addition of retinoic acid (RA), Noggin and Cyclopamine promoted pancreatic differentiation as indicated by the expression of the early pancreatic progenitor markers ISL1, NGN3 and PDX1. Moreover, during maturation in suspension culture, differentiating cells assembled in islet-like clusters, which expressed specific endocrine markers such as PDX1, SST, GCG and INS. Similar results were confirmed with the human induced Pluripotent Stem Cell (hiPSC) line MSUH-001. Finally, differentiation protocols incorporating RSV treatment yielded numerous insulin-positive cells, induced significantly higher PDX1 expression and were able to transiently normalize glycaemia when transplanted in streptozotocin (STZ) induced diabetic mice thus promoting its survival. In conclusion, our strategy allows the efficient differentiation of hESCs into pancreatic endoderm capable of generating β-cell-like cells and demonstrates that RSV improves the maturation process. PMID:25774684

  16. In Vitro Large Scale Production of Human Mature Red Blood Cells from Hematopoietic Stem Cells by Coculturing with Human Fetal Liver Stromal Cells

    Directory of Open Access Journals (Sweden)

    Jiafei Xi

    2013-01-01

    Full Text Available In vitro models of human erythropoiesis are useful in studying the mechanisms of erythroid differentiation in normal and pathological conditions. Here we describe an erythroid liquid culture system starting from cord blood derived hematopoietic stem cells (HSCs. HSCs were cultured for more than 50 days in erythroid differentiation conditions and resulted in a more than 109-fold expansion within 50 days under optimal conditions. Homogeneous erythroid cells were characterized by cell morphology, flow cytometry, and hematopoietic colony assays. Furthermore, terminal erythroid maturation was improved by cosculturing with human fetal liver stromal cells. Cocultured erythroid cells underwent multiple maturation events, including decrease in size, increase in glycophorin A expression, and nuclear condensation. This process resulted in extrusion of the pycnotic nuclei in up to 80% of the cells. Importantly, they possessed the capacity to express the adult definitive β-globin chain upon further maturation. We also show that the oxygen equilibrium curves of the cord blood-differentiated red blood cells (RBCs are comparable to normal RBCs. The large number and purity of erythroid cells and RBCs produced from cord blood make this method useful for fundamental research in erythroid development, and they also provide a basis for future production of available RBCs for transfusion.

  17. Antioxidant and immunomodulatory properties of polysaccharides from Allanblackia floribunda Oliv stem bark and Chromolaena odorata (L.) King and H.E. Robins leaves.

    Science.gov (United States)

    Boudjeko, Thaddée; Megnekou, Rosette; Woguia, Alice Louise; Kegne, Francine Mediesse; Ngomoyogoli, Judith Emery Kanemoto; Tchapoum, Christiane Danielle Nounga; Koum, Olga

    2015-12-09

    Many plant polysaccharides have shown high antioxidant and immunostimulating properties and can be explored as novel molecules with biological properties that can potentially improve immune function. The objective of this work was to characterize soluble and cell wall polysaccharides isolated from the stem bark of Allanblackia floribunda and Chromolaena odorata leaves and to evaluate their antioxidant and immunomodulatory properties. Three polysaccharide fractions: soluble polysaccharides (PoS), pectins (Pec) and hemicelluloses (Hem) were extracted from A. floribunda stem bark and C. odorata leaves. These samples were analysed for their proteins, phenolic compounds and total sugar contents. The monosaccharide composition was determined by gas chromatography and arabinogalactan proteins content in PoS was evaluated by rocket electrophoresis. The in vitro antioxidant activities were evaluated by 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-bis-3-éthylbenzylthiazoline-6-sulphonic acid (ABTS) radical scavenging assays and ferrous ions chelating activity. Immunomodulatory activities were performed on the peripheral blood mononuclear cells (PBMCs) using proliferation and enzyme linked immunospot (ELISPOT) method to determine the production of an interferon-gamma. The characterization of the various fractions showed varied metabolites in each plant. In PoS fractions, Ara and Gal were the major monosaccharides found, indicating that arabinogalactans are the primary macromolecules. Hem fractions contained predominantly Xyl and GalA for A. floribunda and Xyl (upto 80 %) for and C. odorata. A. floribunda Hem fraction and C. odorata PoS fraction showed significant DPPH and ABTS radical scavenging activities and immunostimulatory activity via stimulation of PBMC and production of IFN-γ in a dose-dependent manner. The results obtained from this study support the ethnomedicinal use of the stem bark of A. floribunda and leaves of C. odorata. Further research is

  18. Development of an in vitro culture method for stepwise differentiation of mouse embryonic stem cells and induced pluripotent stem cells into mature osteoclasts.

    Science.gov (United States)

    Nishikawa, Keizo; Iwamoto, Yoriko; Ishii, Masaru

    2014-05-01

    The development of methods for differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cell (iPSCs) into functional cells have helped to analyze the mechanism regulating cellular processes and to explore cell-based assays for drug discovery. Although several reports have demonstrated methods for differentiation of mouse ESCs into osteoclast-like cells, it remains unclear whether these methods are applicable for differentiation of iPSCs to osteoclasts. In this study, we developed a simple method for stepwise differentiation of mouse ESCs and iPSCs into bone-resorbing osteoclasts based upon a monoculture approach consisting of three steps. First, based on conventional hanging-drop methods, embryoid bodies (EBs) were produced from mouse ESCs or iPSCs. Second, EBs were cultured in medium supplemented with macrophage colony-stimulating factor (M-CSF), and differentiated to osteoclast precursors, which expressed CD11b. Finally, ESC- or iPSC-derived osteoclast precursors stimulated with receptor activator of nuclear factor-B ligand (RANKL) and M-CSF formed large multinucleated osteoclast-like cells that expressed tartrate-resistant acid phosphatase and were capable of bone resorption. Molecular analysis showed that the expression of osteoclast marker genes such as Nfatc1, Ctsk, and Acp5 are increased in a RANKL-dependent manner. Thus, our procedure is simple and easy and would be helpful for stem cell-based bone research.

  19. The effects of replacing Dichantium hay with banana (Musa paradisiaca) leaves and pseudo-stem on carcass traits of Ovin Martinik sheep.

    Science.gov (United States)

    Marie-Magdeleine, Carine; Liméa, Léticia; Etienne, Tatiana; Lallo, Cicero H O; Archimède, Harry; Alexandre, Gisele

    2009-10-01

    A study was done to evaluate banana (Musa paradisiaca) as a forage (leaves and pseudo-stems) for feeding Ovin Martinik lambs (OMK), with the aim to test its impact on carcass quality. Forty four intact OMK male were used after weaning with an initial mean live weight of 14.4 (+/- 3.3) kg, reared in individual pens. Animals were offered either Dichantium hay (control diet, Dh) or cut chopped leaves and pseudo-stems of banana (experimental diet, Blps). They were fed 200-250 g x d(-1) of commercial concentrate. Lambs were slaughtered according to 3 classes of slaughter weight (SW): SW20, SW23 and SW26. Growth and carcass performances of both groups were not significantly different, 77 vs. 81 g x d(-1) and 42% vs. 43% hot carcass yield, for Dh vs. Blps, respectively. There was a significant (P < 0.05) decrease (31.0 vs. 29.7%) for the dry matter content of the shoulder for lambs fed the banana diet. However, there was no effect observed for the other chemical component (CP, lipid and mineral 585, 317 and 95 g x kg(-1) DM, respectively). The shoulder (20% of the carcass whatever the SW) was precocious as demonstrated by the allometry coefficient relative to carcass weight (0.894) significantly (P < 0.01) less than 1. It was concluded that, the use of Blps had no significant effect on growth, carcass weights and yields of the OMK lambs, irrespective of the class of the slaughter weight. From these initial results, the use of banana foliages and pseudo-stems could be recommended as sources of forages.

  20. In vitro schistosomicidal effects of aqueous and dichloromethane fractions from leaves and stems of Piper species and the isolation of an active amide from P. amalago L. (Piperaceae).

    Science.gov (United States)

    Carrara, V S; Vieira, S C H; de Paula, R G; Rodrigues, V; Magalhães, L G; Cortez, D A G; Da Silva Filho, A A

    2014-09-01

    Dichloromethane and aqueous fractions from leaves and stems of Piper arboreum Aubl., P. aduncum L., P. amalago L., P. crassinervium H.B. & K., P. diospyrifolium Kunth, P. hispidum Sw. and P. xylosteoides (Kunth) Steud. were tested against adult worms of Schistosoma mansoni. The in vitro activity was evaluated in terms of mortality, number of separated worms and number of worms with reduced motor activity. Most dichloromethane fractions from all Piper species showed moderate schistosomicidal activity, but aqueous fractions were not active. The dichloromethane fraction of P. amalago leaves (at 100 μg/ml) showed the highest activity, resulting in worm mortality, the separation of worm pairs and reduced motor activity. Chromatographic fractionation of the dichloromethane fraction of P. amalago leaves led to the isolation of its major compound, which was also tested against adults of S. mansoni. The isolated piperamide N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine, at 100 μ m, resulted in the mortality of all adult worms after 24 h of incubation. The findings suggest that species of Piper are potential sources of schistosomicidal compounds.

  1. Studies on the antidiabetic effects of Mangifera indica stem-barks and leaves on nondiabetic, type 1 and type 2 diabetic model rats

    Directory of Open Access Journals (Sweden)

    Amrita Bhowmik, Liakot Ali Khan, Masfida Akhter and Begum Rokeya

    2009-12-01

    Full Text Available Mangifera indica Linn, locally known as mango tree has been claimed to possess antidiabetic properties by many investigators. The present study was undertaken to screen the hypoglycemic and antihyperglycemic activity of both ethanol and water extracts of leaves and stem-barks of M. indica in nondiabetic and diabetic model rats in different prandial state. The results showed that all of the extracts had significant antihyperglycemic effect in type 2 diabetic model rats when fed simultaneously with glucose load (p<0.05-0.01; p<0.005-0.001. Moreover, the ethanol extract of stem-barks showed significant antihyperglycemic effect when the extract was fed 30 min prior to the glucose load (p<0.01. Investigations were carried out to evaluate the effect of M. indica on glucose absorption using a rat intestinal preparation in situ. The ethanol extracts of stem-barks reduced glucose absorption gradually during the whole perfusion period in type 2 diabetic rats.

  2. Characterization of calcium signals in human induced pluripotent stem cell-derived dentate gyrus neuronal progenitors and mature neurons, stably expressing an advanced calcium indicator protein.

    Science.gov (United States)

    Vőfély, Gergő; Berecz, Tünde; Szabó, Eszter; Szebényi, Kornélia; Hathy, Edit; Orbán, Tamás I; Sarkadi, Balázs; Homolya, László; Marchetto, Maria C; Réthelyi, János M; Apáti, Ágota

    2018-04-01

    Pluripotent stem cell derived human neuronal progenitor cells (hPSC-NPCs) and their mature neuronal cell culture derivatives may efficiently be used for central nervous system (CNS) drug screening, including the investigation of ligand-induced calcium signalization. We have established hippocampal NPC cultures derived from human induced PSCs, which were previously generated by non-integrating Sendai virus reprogramming. Using established protocols these NPCs were differentiated into hippocampal dentate gyrus neurons. In order to study calcium signaling without the need of dye loading, we have stably expressed an advanced calcium indicator protein (GCaMP6fast) in the NPCs using the Sleeping Beauty transposon system. We observed no significant effects of the long-term GCaMP6 expression on NPC morphology, gene expression pattern or neural differentiation capacity. In order to compare the functional properties of GCaMP6-expressing neural cells and the corresponding parental cells loaded with calcium indicator dye Fluo-4, a detailed characterization of calcium signals was performed. We found that the calcium signals induced by ATP, glutamate, LPA, or proteases - were similar in these two systems. Moreover, the presence of the calcium indicator protein allowed for a sensitive, repeatable detection of changes in calcium signaling during the process of neurogenesis and neuronal maturation. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Conditional induction of Math1 specifies embryonic stem cells to cerebellar granule neuron lineage and promotes differentiation into mature granule neurons.

    Science.gov (United States)

    Srivastava, Rupali; Kumar, Manoj; Peineau, Stéphane; Csaba, Zsolt; Mani, Shyamala; Gressens, Pierre; El Ghouzzi, Vincent

    2013-04-01

    Directing differentiation of embryonic stem cells (ESCs) to specific neuronal subtype is critical for modeling disease pathology in vitro. An attractive means of action would be to combine regulatory differentiation factors and extrinsic inductive signals added to the culture medium. In this study, we have generated mature cerebellar granule neurons by combining a temporally controlled transient expression of Math1, a master gene in granule neuron differentiation, with inductive extrinsic factors involved in cerebellar development. Using a Tetracyclin-On transactivation system, we overexpressed Math1 at various stages of ESCs differentiation and found that the yield of progenitors was considerably increased when Math1 was induced during embryonic body stage. Math1 triggered expression of Mbh1 and Mbh2, two target genes directly involved in granule neuron precursor formation and strong expression of early cerebellar territory markers En1 and NeuroD1. Three weeks after induction, we observed a decrease in the number of glial cells and an increase in that of neurons albeit still immature. Combining Math1 induction with extrinsic factors specifically increased the number of neurons that expressed Pde1c, Zic1, and GABAα6R characteristic of mature granule neurons, formed "T-shaped" axons typical of granule neurons, and generated synaptic contacts and action potentials in vitro. Finally, in vivo implantation of Math1-induced progenitors into young adult mice resulted in cell migration and settling of newly generated neurons in the cerebellum. These results show that conditional induction of Math1 drives ESCs toward the cerebellar fate and indicate that acting on both intrinsic and extrinsic factors is a powerful means to modulate ESCs differentiation and maturation into a specific neuronal lineage. Copyright © 2012 AlphaMed Press.

  4. Differentiation of human-induced pluripotent stem cell under flow conditions to mature hepatocytes for liver tissue engineering

    DEFF Research Database (Denmark)

    Starokozhko, Viktoriia; Hemmingsen, Mette; Larsen, Layla

    2018-01-01

    Hepatic differentiation of human-induced pluripotent stem cells (hiPSCs) under flow conditions in a 3D scaffold is expected to be a major step forward for construction of bioartificial livers. The aims of this study were to induce hepatic differentiation of hiPSCs under perfusion conditions...... and to perform functional comparisons with fresh human precision-cut liver slices (hPCLS), an excellent benchmark for the human liver in vivo. The majority of the mRNA expression of CYP isoenzymes and transporters and the tested CYP activities, Phase II metabolism, and albumin, urea, and bile acid synthesis...... in the hiPSC-derived cells reached values that overlap those of hPCLS, which indicates a higher degree of hepatic differentiation than observed until now. Differentiation under flow compared with static conditions had a strong inducing effect on Phase II metabolism and suppressed AFP expression but resulted...

  5. Culture conditions have an impact on the maturation of traceable, transplantable mouse embryonic stem cell-derived otic progenitor cells.

    Science.gov (United States)

    Abboud, Nesrine; Fontbonne, Arnaud; Watabe, Isabelle; Tonetto, Alain; Brezun, Jean Michel; Feron, François; Zine, Azel

    2017-09-01

    The generation of replacement inner ear hair cells (HCs) remains a challenge and stem cell therapy holds the potential for developing therapeutic solutions to hearing and balance disorders. Recent developments have made significant strides in producing mouse otic progenitors using cell culture techniques to initiate HC differentiation. However, no consensus has been reached as to efficiency and therefore current methods remain unsatisfactory. In order to address these issues, we compare the generation of otic and HC progenitors from embryonic stem (ES) cells in two cell culture systems: suspension vs. adherent conditions. In the present study, an ES cell line derived from an Atoh1-green fluorescent protein (GFP) transgenic mouse was used to track the generation of otic progenitors, initial HCs and to compare these two differentiation systems. We used a two-step short-term differentiation method involving an induction period of 5 days during which ES cells were cultured in the presence of Wnt/transforming growth factor TGF-β inhibitors and insulin-like growth factor IGF-1 to suppress mesoderm and reinforce presumptive ectoderm and otic lineages. The generated embryoid bodies were then differentiated in medium containing basic fibroblast growth factor (bFGF) for an additional 5 days using either suspension or adherent culture methods. Upon completion of differentiation, quantitative polymerase chain reaction analysis and immunostaining monitored the expression of otic/HC progenitor lineage markers. The results indicate that cells differentiated in suspension cultures produced cells expressing otic progenitor/HC markers at a higher efficiency compared with the production of these cell types within adherent cultures. Furthermore, we demonstrated that a fraction of these cells can incorporate into ototoxin-injured mouse postnatal cochlea explants and express MYO7A after transplantation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons

  6. Chemical Composition of the Essential Oils of the Flowers, Leaves and Stems of Two Senecio polyanthemoides Sch. Bip. Samples from South Africa

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    Lawal A. Oladipupo

    2009-06-01

    Full Text Available The essential oils of the flowers, leaves and stems of Senecio polyanthemoides Sch. Bip. Samples collected from two different localities within the city of uMhlathuze, KwaZulu-Natal Province (South Africa were isolated by hydrodistillation and analyzed using GC and GC/MS. Twenty-six constituents were identified, representing an average of 86.0 - 99.6% of the total oil composition. The chemical profile reveals the dominance of monoterpenoid compounds, although some quantitative variance was noticed. The main constituents of the oils were limonene (3.1 – 43.0%, p-cymene (4.9-36.3%, β-selinene (1.3-32.7%, α-pinene (1.8-21.4%, β-pinene (7.6-16.5% and 1,8-cineole (9.3-11.4%, caryophyllene oxide (4.1-13.4% and humulene epoxide II (8.6-10.3%.

  7. Direct and efficient transfection of mouse neural stem cells and mature neurons by in vivo mRNA electroporation.

    Science.gov (United States)

    Bugeon, Stéphane; de Chevigny, Antoine; Boutin, Camille; Coré, Nathalie; Wild, Stefan; Bosio, Andreas; Cremer, Harold; Beclin, Christophe

    2017-11-01

    In vivo brain electroporation of DNA expression vectors is a widely used method for lineage and gene function studies in the developing and postnatal brain. However, transfection efficiency of DNA is limited and adult brain tissue is refractory to electroporation. Here, we present a systematic study of mRNA as a vector for acute genetic manipulation in the developing and adult brain. We demonstrate that mRNA electroporation is far more efficient than DNA electroporation, and leads to faster and more homogeneous protein expression in vivo Importantly, mRNA electroporation allows the manipulation of neural stem cells and postmitotic neurons in the adult brain using minimally invasive procedures. Finally, we show that this approach can be efficiently used for functional studies, as exemplified by transient overexpression of the neurogenic factor Myt1l and by stably inactivating Dicer nuclease in vivo in adult born olfactory bulb interneurons and in fully integrated cortical projection neurons. © 2017. Published by The Company of Biologists Ltd.

  8. Evaluation of the Acetone and Aqueous Extracts of Mature Stem Bark of Sclerocarya birrea for Antioxidant and Antimicrobial Properties

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    Nicoline F. Tanih

    2012-01-01

    Full Text Available We assayed the antimicrobial activity of acetone and aqueous extracts of the stem bark of Sclerocarya birrea on some selected bacteria and fungi species including; Streptococcus pyogenes, Plesiomonas shigelloides, Aeromonas hydrophila, Salmonella typhimurium, Cryptococcus neoformans, Candida glabrata, Trichosporon mucoides, and Candida krusei using both agar well diffusion and minimum inhibitory concentration (MIC assays. Based on the levels of activity, the acetone extract was examined for total polyphenolic content, radical scavenging and antioxidant activities. Total phenols of the extract were determined spectrophotometrically. The antioxidant activity was determined by the DPPH, ABTS and reducing power. All the bacteria and fungi species were susceptible to the plant extracts. The acetone extract was the most active for the bacterial species with MIC (0.156–0.625 mg/mL while the aqueous extract was the most active for the fungi species with MIC (0.3125–1.25 mg/mL. The polyphenolic compounds were found as 27.2 mg/g tannic acid equivalent, 25.2 mg/g quercetin equivalent, 9.1 mg/g quercetin equivalent for phenols, flavonoid and flavonols respectively. The acetone extract exhibited a remarkable ability to scavenge radicals, strong reducing ability and a potential source of natural antioxidants. Both the acetone and aqueous extracts of S. birrea may provide a target for drug discovery.

  9. The Neutral Detergent Fiber Digestibility of Some Tropical Grasses at Different Stage of Maturity

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    P Mahyuddin

    2009-09-01

    Full Text Available The digestibility of neutral detergent fiber (IVNDFD was determined by Telly and Terry methods in vitro on 5 tropical grasses species, Sorghum, Themeda, Iseilema, Brachyacne and Dicanthium. Stem and leaf samples were harvested at different maturity stages, started from early flowering stage to the stage when the grasses were dried. In general, IVNDFD ranged from 22% to 41%. Stages of maturity affected IVNDFD in 4 species; IVNDFD was higher in the stems than in the leaves for 2 species out of 5 species of grasses; the rest was similar. There was no correlation between NDF and IVNDFD, showing that NDF degradability in the rumen was vary. Digestibility potential of NDF (PDNDF varied from 21% to 44% and has negative correlation with IVNDFD (r=0.75. Growth affected PDNDF in 2 species; and 3 out 5 species observed showed PDNDF in the leaves was higher than that in the stems. Negative correlation was exist between dry matter digestibility (IVDMD, water soluble extract (WSE and protein with PDNDF. Grasses with stated PDNDF values have relatively high NDF retention in the rumen, which will cause low NDF or dry matter consumption. (Animal Production 11(3: 189-195 (2009Key Words: NDF digestibility, tropical grasses, stem, leaves, maturity stage

  10. Cord blood-derived macrophage-lineage cells rapidly stimulate osteoblastic maturation in mesenchymal stem cells in a glycoprotein-130 dependent manner.

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    Tania J Fernandes

    Full Text Available In bone, depletion of osteoclasts reduces bone formation in vivo, as does osteal macrophage depletion. How osteoclasts and macrophages promote the action of bone forming osteoblasts is, however, unclear. Since recruitment and differentiation of multi-potential stromal cells/mesenchymal stem cells (MSC generates new active osteoblasts, we investigated whether human osteoclasts and macrophages (generated from cord blood-derived hematopoietic progenitors induce osteoblastic maturation in adipose tissue-derived MSC. When treated with an osteogenic stimulus (ascorbate, dexamethasone and β-glycerophosphate these MSC form matrix-mineralising, alkaline phosphatase-expressing osteoblastic cells. Cord blood-derived progenitors were treated with macrophage colony stimulating factor (M-CSF to form immature proliferating macrophages, or with M-CSF plus receptor activator of NFκB ligand (RANKL to form osteoclasts; culture medium was conditioned for 3 days by these cells to study their production of osteoblastic factors. Both osteoclast- and macrophage-conditioned medium (CM greatly enhanced MSC osteoblastic differentiation in both the presence and absence of osteogenic medium, evident by increased alkaline phosphatase levels within 4 days and increased mineralisation within 14 days. These CM effects were completely ablated by antibodies blocking gp130 or oncostatin M (OSM, and OSM was detectable in both CM. Recombinant OSM very potently stimulated osteoblastic maturation of these MSC and enhanced bone morphogenetic protein-2 (BMP-2 actions on MSC. To determine the influence of macrophage activation on this OSM-dependent activity, CM was collected from macrophage populations treated with M-CSF plus IL-4 (to induce alternative activation or with GM-CSF, IFNγ and LPS to cause classical activation. CM from IL-4 treated macrophages stimulated osteoblastic maturation in MSC, while CM from classically-activated macrophages did not. Thus, macrophage-lineage cells

  11. Phytochemical analysis and antimicrobial activity of baobab (Adansonia digitata leaves and stem bark extracts on Staphylococcus aureus and Escherichia coli

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    Mohammed Sani Sambo Datsugwai

    2017-05-01

    Full Text Available The phytochemical analysis and antibacterial activity of methanolic and ethanolic leaf and stem bark extracts of baobab tree on Escherichia coli and Staphylococcus aureus were carried out using agar well diffusion method. The clinical bacterial isolates of Escherichia coli and Staphylococcus aureus were obtained from Microbiology laboratory, Kaduna State University, Kaduna. The bacteria isolates were re-confirmed and identified based on their morphology, cultural characteristics and biochemical tests. The bacteria isolates were confirmed to be Escherichia coli and Staphylococcus aureus. The phytochemical analysis revealed the presence of Alkaloids, Saponins, Flavonoids, Tannins and Terpenoids. The methanolic leaf extract showed a wide range of activity on test isolates, with varying zones of inhibitions as 12 mm, 10 mm, 7 mm, and 4 mm against Staphylococcus aureus and 13 mm, 9 mm, 7 mm, and 3 mm against Escherichia coli at concentration of 1000 mg/ml, 500 mg/ml, 200 mg/ml and 100 mg/ml respectively. The ethanolic leaf extract also showed a wide range of activity on test isolates with varying zones of inhibitions, such as 11mm, 6mm, 5mm and 3mm against S. aureus and 8mm, 7mm, 5mm, and 4mm against E. coli at the concentration of 1000 mg/ml, 500mg/ml, 200 mg/ml and 100mg/ml for each respectively. The methanolic stem bark extract showed less antibacterial activity against the test isolates with the inhibition of 5mm and 4mm against S. aureus and 4mm and 3mm against E.coli at concentration of 1000 mg/ml and 500 mg/ml respectively with no zones of inhibition at concentration of 200 mg/ml and 100mg/ml. The ethanolic stem bark extract also showed no antibacterial activity with no zones of inhibition against the test isolates at concentration of 1000 mg/ml, 500 mg/ml, 200mg/ml and 100 mg/ml. The methanolic leaf extract inhibited the growth of S. aureus and E.coli at concentration of 100 mg/ml with minimum bactericidal concentration at 100 mg/ml. The

  12. A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer

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    Mohammad Al Sadoon

    2010-09-01

    Full Text Available Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl, polyvinylpyrrolidone (PVP and lithium chloride (LiCl with the cetyltrimethylammonium bromide (CTAB method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification.

  13. Enrichment of human embryonic stem cell-derived NKX6.1-expressing pancreatic progenitor cells accelerates the maturation of insulin-secreting cells in vivo.

    Science.gov (United States)

    Rezania, Alireza; Bruin, Jennifer E; Xu, Jean; Narayan, Kavitha; Fox, Jessica K; O'Neil, John J; Kieffer, Timothy J

    2013-11-01

    Human embryonic stem cells (hESCs) are considered a potential alternative to cadaveric islets as a source of transplantable cells for treating patients with diabetes. We previously described a differentiation protocol to generate pancreatic progenitor cells from hESCs, composed of mainly pancreatic endoderm (PDX1/NKX6.1-positive), endocrine precursors (NKX2.2/synaptophysin-positive, hormone/NKX6.1-negative), and polyhormonal cells (insulin/glucagon-positive, NKX6.1-negative). However, the relative contributions of NKX6.1-negative versus NKX6.1-positive cell fractions to the maturation of functional β-cells remained unclear. To address this question, we generated two distinct pancreatic progenitor cell populations using modified differentiation protocols. Prior to transplant, both populations contained a high proportion of PDX1-expressing cells (~85%-90%) but were distinguished by their relatively high (~80%) or low (~25%) expression of NKX6.1. NKX6.1-high and NKX6.1-low progenitor populations were transplanted subcutaneously within macroencapsulation devices into diabetic mice. Mice transplanted with NKX6.1-low cells remained hyperglycemic throughout the 5-month post-transplant period whereas diabetes was reversed in NKX6.1-high recipients within 3 months. Fasting human C-peptide levels were similar between groups throughout the study, but only NKX6.1-high grafts displayed robust meal-, glucose- and arginine-responsive insulin secretion as early as 3 months post-transplant. NKX6.1-low recipients displayed elevated fasting glucagon levels. Theracyte devices from both groups contained almost exclusively pancreatic endocrine tissue, but NKX6.1-high grafts contained a greater proportion of insulin-positive and somatostatin-positive cells, whereas NKX6.1-low grafts contained mainly glucagon-expressing cells. Insulin-positive cells in NKX6.1-high, but not NKX6.1-low grafts expressed nuclear MAFA. Collectively, this study demonstrates that a pancreatic endoderm

  14. Differential responses between mature and young leaves of sunflower plants to oxidative stress caused by water deficit Diferentes respostas entre folhas adultas e jovens de plantas de girassol ao estresse oxidativo causado pelo déficit hídrico

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    Inês Cechin

    2010-06-01

    Full Text Available The effects of water stress and rehydration on leaf gas exchange characteristics along with changes in lipid peroxidation and pirogalol peroxidase (PG-POD were studied in mature and in young leaves of sunflower (Helianthus annuus L., which were grown in a greenhouse. Water stress reduced photosynthesis (Pn, stomatal conductance (g s, and transpiration (E in both young and mature leaves. However, the amplitude of the reduction was dependent on leaf age. The intercellular CO2 concentration (Ci was increased in mature leaves but it was not altered in young leaves. Instantaneous water use efficiency (WUE in mature stressed leaves was reduced when compared to control leaves while in young stressed leaves it was maintained to the same level as the control. After 24h of rehydration, most of the parameters related to gas exchange recovered to the same level as the unstressed plants except gs and E in mature leaves. Water stress did not activated PG-POD independently of leaf age. However, after rehydration the enzyme activity was increased in mature leaves and remained to the same as the control in young leaves. Malondialdehyde (MDA content was increased by water stress in both mature and young leaves. The results suggest that young leaves are more susceptible to water stress in terms of gas exchange characteristics than mature leaves although both went through oxidative estresse.Os efeitos do estresse hídrico e da reidratação nas trocas gasosas juntamente com alterações na lipoperoxidação e atividade da pirogalol peroxidase (PG-POD foram estudados em folhas adultas e jovens de plantas de girassol (Helianthus annuus L. cultivadas em casa de vegetação. O estresse hídrico reduziu a fotossíntese (P N, a condutância estomática (g s e a transpiração (E nas folhas adultas e jovens. No entanto, a amplitude da redução foi dependente da idade da folha. A concentração intercelular de CO2 (Ci aumentou nas folhas adultas, mas não apresentou

  15. Antioxidative, anti-inflammatory potentials and phytochemical profile of Commiphora africana(A. Rich.) Engl.(Burseraceae) and Loeseneriella africana(Willd.)(Celastraceae) stem leaves extracts

    Institute of Scientific and Technical Information of China (English)

    Moussa Compaoré; Roland Ng-Tiéro Meda; Sahabi Bakasso; Laurian Vlase; Martin Kiendrebeogo

    2016-01-01

    Objective: To assess the antioxidant and anti-inflammatory activities as well as to determine the flavonoids and phenolic acids content of active fractions.Methods: Two medicinal plant samples were extracted successively in Soxhlet apparatus with n-hexane, dichloromethane, acetonitrile, ethyl acetate, methanol and n-butanol. Five methods were used to evaluate the antioxidant activity. Anti-inflammatory activity was done through the inhibition of the cyclooxygenase enzymes(COX-1 and COX-2).Polyphenolic compounds were analyzed by using a spectrophotometrical and high performance liquid chromatography-mass spectrometry(HPLC-MS) methods.Results: The data showed that the stem leaves extracts of Commiphora africana and Loeseneriella africana possessed significant in vitro antioxidant and anti-inflammatory activities. Polar extracts had radical scavenging effects and they reduced iron(III). The prostaglandin production was significantly stopped by acetonitrile and methanol extracts.These biological activities were supported by some bioactive compounds quantified by using the HPLC-MS. p-Coumaric acid, ferulic acid, isoquercitrin, quercitrin, quercetin,rutin, kaempferol and apigenin were the most metabolites quantified.Conclusions: The present study may explain the effectiveness of plants in traditional medicine of Burkina Faso, singularly Commiphora africana and Loeseneriella africana.The next investigation was to sub-fractionate the methanol fraction in order to isolate new antioxidant and/or anti-inflammatory compounds.

  16. Optimization of dynamic-microwave assisted enzymatic hydrolysis extraction of total ginsenosides from stems and leaves of panax ginseng by response surface methodology.

    Science.gov (United States)

    Wang, Xiao-Yan; Ren, Hui

    2018-03-21

    Ginseng stems and leaves (GSAL) are abundant in ginsenosides compounds. For efficient utilization of GSAL and the enhancement of total ginsenosides (TG) compound yields in GSAL, TG from GSAL were extracted, using dynamic-microwave assisted extraction coupled with enzymatic hydrolysis (DMAE-EH) method. The extraction process has been simulated and its main influencing factors such as ethanol concentration, microwave temperature, microwave time and pump flow rate have been optimized by response surface methodology coupled with a Box-Behnken design(BBD). The experimental results indicated that optimal extraction conditions of TG from GSAL were as follows: ethanol concentration of 75%, microwave temperature of 60°C, microwave time of 20 min and pump flow rate of 38 r/min. After experimental verification, the experimental yields of TG was 60.62 ± 0.85 mg g -1 , which were well agreement with the predicted by the model. In general, the present results demonstrated that DMAE-EH method was successfully used to extract total ginsenosides in GSAL.

  17. Variation in essential oil composition within individual leaves of sweet basil (Ocimum basilicum L.) is more affected by leaf position than by leaf age.

    Science.gov (United States)

    Fischer, Ravit; Nitzan, Nadav; Chaimovitsh, David; Rubin, Baruch; Dudai, Nativ

    2011-05-11

    The aroma in sweet basil is a factor affecting the commercial value of the crop. In previous studies leaf age was considered to be a factor that influences the composition of essential oil (EO). In this study it was hypothesized that a single observation of the EO content in leaves from different positions on the main stem (young vs old) could predict the developmental changes in the plant during its life cycle. Plants harvested at week 16 demonstrated an exponential increase (R(2) = 0.92) in EO concentration in leaves on the main stem and lateral shoots, indicating higher EO concentrations in younger than in older leaves. Eugenol and methyleugenol predominated (28-77%) in the extract. Eugenol levels were higher in younger leaves (∼53%), and methyl-eugenol levels predominated in older leaves (∼68%). Linalool was lower in mature leaves than in younger leaves. This suggested that eugenol converted into methyleugenol and linalool decreased as leaf mature. However, in weekly monitored plants, the levels of these compounds in the EO had limited variation in the maturing leaf regardless of its position on the stem. This proposed that the EO composition in an individual leaf is mostly affected by the leaf position on the stem and not by its maturation process. Because leaf position is related to plant development, it is probable that the plant's physiological age at the time of leaf formation from the primordial tissue is the factor affecting the EO composition. It was concluded that interpretation of scientific observations should be carried out with caution and that hypotheses should be tested utilizing multifaceted approaches.

  18. Abutilon ornamental (Abutilon sp. - Malvaceae mostrando pústulas de Synchytrium australe Pustules on stems, leaves and pods of ornamental abutilon (Abutilon sp. caused by Synchytrium australe

    Directory of Open Access Journals (Sweden)

    Mário Barreto Figueiredo

    2007-06-01

    Full Text Available Plantas de abutilon recebidas para análise fitopatológica pelo Instituto Biológico, São Paulo, Brasil mostrando como sintomas pústulas semelhantes a ferrugem (Uredinales sobre folhas e caule foram estudadas para determinar o agente causal. Numerosos esporângios amarelos característicos de fungos zoospóricos pertencentes à Ordem Chytridiales foram encontrados no interior de galhas superficiais. Com base no estudo de KARLING (1955, o patógeno foi identificado como Synchytrium australe Speg. O material foi herborizado e armazenado no Herbário Micológico do Instituto Biológico sob o número IBI/SP 11975. Esta foi a primeira constatação desta espécie no Brasil.The genus Abutilon includes a large number of ornamental species with nice foliage and flowers. The different species are known under several common names as Indian mallow, China jute, butterprint, etc. Plants of abutilon received for phytopathological analysis by the Instituto Biologico, São Paulo, Brazil showing curious rust like symptoms (pustules on leaves, stems and pods were studied to determine the causal agent. Numerous yellow sporangia characteristic of zoosporic fungi belonging to the Order Chytridiales were found within the superficial intact galls. Based on KARLING (1955 paper the pathogen was identified as Synchytrium australe Speg. The voucher material was saved and settled in the Mycological Herbarium of the Institution under the number IBI/SP 11975. This was the first report of the occurrence of this species in Brazil.

  19. Generation of an induced pluripotent stem cell (iPSC line from a patient with maturity-onset diabetes of the young type 3 (MODY3 carrying a hepatocyte nuclear factor 1-alpha (HNF1A mutation

    Directory of Open Access Journals (Sweden)

    Frank Griscelli

    2018-05-01

    Full Text Available Heterozygous non-synonymous (p.S142F mutation in HNF1A leads to maturity-onset diabetes of the young (MODY type 3, which is a subtype of dominant inherited young-onset non-autoimmune diabetes due to the defect of insulin secretion from pancreatic beta cells. We generated induced pluripotent stem cells (iPSCs from a patient with HNF1A p.S142F mutation. Cells from this patient, which were reprogrammed by non-integrative viral transduction had normal karyotype, harboured the HNF1A p.S142F mutation, expressed pluripotency hallmarks.

  20. Partitioning of current photosynthate to different chemical fractions in leaves, stems, and roots of northern red oak seedlings during episodic growth

    Science.gov (United States)

    Richard E. Dickson; Patricia T. Tomlinson; J. G. Isebrands

    2000-01-01

    The episodic or flushing growth habit of northern red oak (Quercus rubra L.,) has a significant influence on carbon fixation, carbon transport from source leaves, and carbon allocation within the plant; however, the impact of episodic growth on carbon parciprioning among chemical fractions is unknown. Median-flush leaves of the first and second flush...

  1. Naturally Engineered Maturation of Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Gaetano J. Scuderi

    2017-05-01

    Full Text Available Ischemic heart disease remains one of the most prominent causes of mortalities worldwide with heart transplantation being the gold-standard treatment option. However, due to the major limitations associated with heart transplants, such as an inadequate supply and heart rejection, there remains a significant clinical need for a viable cardiac regenerative therapy to restore native myocardial function. Over the course of the previous several decades, researchers have made prominent advances in the field of cardiac regeneration with the creation of in vitro human pluripotent stem cell-derived cardiomyocyte tissue engineered constructs. However, these engineered constructs exhibit a functionally immature, disorganized, fetal-like phenotype that is not equivalent physiologically to native adult cardiac tissue. Due to this major limitation, many recent studies have investigated approaches to improve pluripotent stem cell-derived cardiomyocyte maturation to close this large functionality gap between engineered and native cardiac tissue. This review integrates the natural developmental mechanisms of cardiomyocyte structural and functional maturation. The variety of ways researchers have attempted to improve cardiomyocyte maturation in vitro by mimicking natural development, known as natural engineering, is readily discussed. The main focus of this review involves the synergistic role of electrical and mechanical stimulation, extracellular matrix interactions, and non-cardiomyocyte interactions in facilitating cardiomyocyte maturation. Overall, even with these current natural engineering approaches, pluripotent stem cell-derived cardiomyocytes within three-dimensional engineered heart tissue still remain mostly within the early to late fetal stages of cardiomyocyte maturity. Therefore, although the end goal is to achieve adult phenotypic maturity, more emphasis must be placed on elucidating how the in vivo fetal microenvironment drives cardiomyocyte

  2. Taking Leave?

    CERN Multimedia

    2000-01-01

    Planning a holiday? Then if you're a member of the personnel, you'll need to use the Laboratory's new leave system that will be put in place on 1 October. Leave allocations don't change - you are entitled to just as much holiday as before - but instead of being credited annually, your leave will be credited on a monthly basis, and this information will be communicated on your salary slip. The reason for the change is that with the various new leave schemes such as Recruitment by Saved Leave (RSL) and the Progressive Retirement Programme (PRP), a streamlined procedure was required for dealing with all kinds of leave. In the new system, each member of the personnel will have leave accounts to which leave will be credited monthly from the payroll and debited each time an absence is registered in the CERN Electronic Document Handling system (EDH). Leave balances will appear on monthly pay slips, and full details of leave transactions and balances will be available through EDH at all times. As the leave will be c...

  3. Alternative donor hematopoietic stem cell transplantation for mature lymphoid malignancies after reduced-intensity conditioning regimen: Similar outcomes with umbilical cord blood and unrelated donor peripheral blood

    NARCIS (Netherlands)

    C.A. Rodrigues (Celso Arrais); V. Rocha (Vanderson); P. Dreger (Peter); C.G. Brunstein (Claudio); H. Sengeloev (Henrik); J. Finke (Jürgen); M. Mohty (Mohamad); B. Rio (Bernard); E. Petersen (Eefke); F. Guilhot (François); D. Niederwieser (Dietger); J.J. Cornelissen (Jan); P. Jindra (Pavel); A. Nagler (Arnon); N. Fegueux (Nathalie); H. Schoemans (Hélène); A. Ruggeri (Annelisa); S.P. Robinson (Stephen); E. Gluckman (Eliane); C. Canals (Carmen); A. Sureda (Anna)

    2014-01-01

    textabstractWe have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who

  4. Women 1.5 Times More Likely to Leave STEM Pipeline after Calculus Compared to Men: Lack of Mathematical Confidence a Potential Culprit.

    Science.gov (United States)

    Ellis, Jessica; Fosdick, Bailey K; Rasmussen, Chris

    2016-01-01

    The substantial gender gap in the science, technology, engineering, and mathematics (STEM) workforce can be traced back to the underrepresentation of women at various milestones in the career pathway. Calculus is a necessary step in this pathway and has been shown to often dissuade people from pursuing STEM fields. We examine the characteristics of students who begin college interested in STEM and either persist or switch out of the calculus sequence after taking Calculus I, and hence either continue to pursue a STEM major or are dissuaded from STEM disciplines. The data come from a unique, national survey focused on mainstream college calculus. Our analyses show that, while controlling for academic preparedness, career intentions, and instruction, the odds of a woman being dissuaded from continuing in calculus is 1.5 times greater than that for a man. Furthermore, women report they do not understand the course material well enough to continue significantly more often than men. When comparing women and men with above-average mathematical abilities and preparedness, we find women start and end the term with significantly lower mathematical confidence than men. This suggests a lack of mathematical confidence, rather than a lack of mathematically ability, may be responsible for the high departure rate of women. While it would be ideal to increase interest and participation of women in STEM at all stages of their careers, our findings indicate that if women persisted in STEM at the same rate as men starting in Calculus I, the number of women entering the STEM workforce would increase by 75%.

  5. Women 1.5 Times More Likely to Leave STEM Pipeline after Calculus Compared to Men: Lack of Mathematical Confidence a Potential Culprit

    Science.gov (United States)

    Ellis, Jessica; Fosdick, Bailey K.; Rasmussen, Chris

    2016-01-01

    The substantial gender gap in the science, technology, engineering, and mathematics (STEM) workforce can be traced back to the underrepresentation of women at various milestones in the career pathway. Calculus is a necessary step in this pathway and has been shown to often dissuade people from pursuing STEM fields. We examine the characteristics of students who begin college interested in STEM and either persist or switch out of the calculus sequence after taking Calculus I, and hence either continue to pursue a STEM major or are dissuaded from STEM disciplines. The data come from a unique, national survey focused on mainstream college calculus. Our analyses show that, while controlling for academic preparedness, career intentions, and instruction, the odds of a woman being dissuaded from continuing in calculus is 1.5 times greater than that for a man. Furthermore, women report they do not understand the course material well enough to continue significantly more often than men. When comparing women and men with above-average mathematical abilities and preparedness, we find women start and end the term with significantly lower mathematical confidence than men. This suggests a lack of mathematical confidence, rather than a lack of mathematically ability, may be responsible for the high departure rate of women. While it would be ideal to increase interest and participation of women in STEM at all stages of their careers, our findings indicate that if women persisted in STEM at the same rate as men starting in Calculus I, the number of women entering the STEM workforce would increase by 75%. PMID:27410262

  6. Women 1.5 Times More Likely to Leave STEM Pipeline after Calculus Compared to Men: Lack of Mathematical Confidence a Potential Culprit.

    Directory of Open Access Journals (Sweden)

    Jessica Ellis

    Full Text Available The substantial gender gap in the science, technology, engineering, and mathematics (STEM workforce can be traced back to the underrepresentation of women at various milestones in the career pathway. Calculus is a necessary step in this pathway and has been shown to often dissuade people from pursuing STEM fields. We examine the characteristics of students who begin college interested in STEM and either persist or switch out of the calculus sequence after taking Calculus I, and hence either continue to pursue a STEM major or are dissuaded from STEM disciplines. The data come from a unique, national survey focused on mainstream college calculus. Our analyses show that, while controlling for academic preparedness, career intentions, and instruction, the odds of a woman being dissuaded from continuing in calculus is 1.5 times greater than that for a man. Furthermore, women report they do not understand the course material well enough to continue significantly more often than men. When comparing women and men with above-average mathematical abilities and preparedness, we find women start and end the term with significantly lower mathematical confidence than men. This suggests a lack of mathematical confidence, rather than a lack of mathematically ability, may be responsible for the high departure rate of women. While it would be ideal to increase interest and participation of women in STEM at all stages of their careers, our findings indicate that if women persisted in STEM at the same rate as men starting in Calculus I, the number of women entering the STEM workforce would increase by 75%.

  7. An expandable embryonic stem cell-derived Purkinje neuron progenitor population that exhibits in vivo maturation in the adult mouse cerebellum

    NARCIS (Netherlands)

    Higuera, Gustavo A; Iaffaldano, Grazia; Bedar, Meiwand; Shpak, Guy; Broersen, Robin; Munshi, Shashini T; Dupont, Catherine; Gribnau, Joost; de Vrij, Femke M S; Kushner, Steven A; De Zeeuw, Chris I

    2017-01-01

    The directed differentiation of patient-derived induced pluripotent stem cells into cell-type specific neurons has inspired the development of therapeutic discovery for neurodegenerative diseases. Many forms of ataxia result from degeneration of cerebellar Purkinje cells, but thus far it has not

  8. An expandable embryonic stem cell-derived Purkinje neuron progenitor population that exhibits in vivo maturation in the adult mouse cerebellum

    NARCIS (Netherlands)

    G.A. Higuera (Gustavo A.); Iaffaldano, G. (Grazia); Bedar, M. (Meiwand); G. Shpak (Guy); R. Broersen (Robin); S.T. Munshi (Shashini T.); Dupont, C. (Catherine); J.H. Gribnau (Joost); F.M.S. Vrij (Femke); S.A. Kushner (Steven); C.I. de Zeeuw (Chris)

    2017-01-01

    textabstractThe directed differentiation of patient-derived induced pluripotent stem cells into cell-type specific neurons has inspired the development of therapeutic discovery for neurodegenerative diseases. Many forms of ataxia result from degeneration of cerebellar Purkinje cells, but thus far it

  9. Characterising the developmental profile of human embryonic stem cell-derived medium spiny neuron progenitors and assessing mature neuron function using a CRISPR-generated human DARPP-32WT/eGFP-AMP reporter line.

    Science.gov (United States)

    Hunt, C P J; Pouton, C W; Haynes, J M

    2017-06-01

    In the developing ventral telencephalon, cells of the lateral ganglionic eminence (LGE) give rise to all medium spiny neurons (MSNs). This development occurs in response to a highly orchestrated series of morphogenetic stimuli that pattern the resultant neurons as they develop. Striatal MSNs are characterised by expression of dopamine receptors, dopamine-and cyclic AMP-regulated phosphoprotein (DARPP32) and the neurotransmitter GABA. In this study, we demonstrate that fine tuning Wnt and hedgehog (SHH) signaling early in human embryonic stem cell differentiation can induce a subpallial progenitor molecular profile. Stimulation of TGFβ signaling pathway by activin-A further supports patterning of progenitors to striatal precursors which adopt an LGE-specific gene signature. Moreover, we report that these MSNs also express markers associated with mature neuron function (cannabinoid, adenosine and dopamine receptors). To facilitate live-cell identification we generated a human embryonic stem cell line using CRISPR-mediated gene editing at the DARPP32 locus (DARPP32 WT/eGFP-AMP-LacZ ). The addition of dopamine to MSNs either increased, decreased or had no effect on intracellular calcium, indicating the presence of multiple dopamine receptor subtypes. In summary, we demonstrate greater control over early fate decisions using activin-A, Wnt and SHH to direct differentiation into MSNs. We also generate a DARPP32 reporter line that enables deeper pharmacological profiling and interrogation of complex receptor interactions in human MSNs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Crystal macropattern development in Prunus serotina (Rosaceae, Prunoideae) leaves.

    Science.gov (United States)

    Lersten, Nels R; Horner, Harry T

    2006-05-01

    Prunus, subgenus Padus, exhibits two completely different calcium oxalate crystal macropatterns in mature leaves. Foliar macropattern development has been described previously in P. virginiana, representing one version. Prunus serotina, in the group exhibiting the second macropattern, is described here. The goal was to describe developmental details for comparison with P. virginiana, and to extend the sparse current knowledge of crystal macropatterns. Leaves at various developmental stages were removed from local trees and from herbarium specimens. Early leaf stages and freehand leaf and stem sections were mounted directly in aqueous glycerine; larger leaves were processed whole or in representative pieces in household bleach, dehydrated in alcohol/xylol, and mounted in Permount. Crystals were detected microscopically between crossed polarizers. Bud scales have a dense druse population. Druses appear first at the stipule tip and proliferate basipetally but soon stop forming; growing stipules therefore have a declining density of druses. Druses appear at the tip of leaves virginiana, and shows that two closely related species can develop radically different modes of crystallization. The few detailed macropattern studies to date reveal striking variations that indicate a new level of organization that must be integrated with the anatomical, physiological and molecular approaches that have been dominant so far.

  11. Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi

    2016-01-01

    Recent advancements in set theory and readily available software have enabled social science researchers to bridge the variable-centered quantitative and case-based qualitative methodological paradigms in order to analyze multi-dimensional associations beyond the linearity assumptions, aggregate...... effects, unicausal reduction, and case specificity. Based on the developments in set theoretical thinking in social sciences and employing methods like Qualitative Comparative Analysis (QCA), Necessary Condition Analysis (NCA), and set visualization techniques, in this position paper, we propose...... and demonstrate a new approach to maturity models in the domain of Information Systems. This position paper describes the set-theoretical approach to maturity models, presents current results and outlines future research work....

  12. Vascular wall-resident CD44+ multipotent stem cells give rise to pericytes and smooth muscle cells and contribute to new vessel maturation.

    Directory of Open Access Journals (Sweden)

    Diana Klein

    Full Text Available Here, we identify CD44(+CD90(+CD73(+CD34(-CD45(- cells within the adult human arterial adventitia with properties of multipotency which were named vascular wall-resident multipotent stem cells (VW-MPSCs. VW-MPSCs exhibit typical mesenchymal stem cell characteristics including cell surface markers in immunostaining and flow cytometric analyses, and differentiation into adipocytes, chondrocytes and osteocytes under culture conditions. Particularly, TGFß1 stimulation up-regulates smooth muscle cell markers in VW-MPSCs. Using fluorescent cell labelling and co-localisation studies we show that VW-MPSCs differentiate to pericytes/smooth muscle cells which cover the wall of newly formed endothelial capillary-like structures in vitro. Co-implantation of EGFP-labelled VW-MPSCs and human umbilical vein endothelial cells into SCID mice subcutaneously via Matrigel results in new vessels formation which were covered by pericyte- or smooth muscle-like cells generated from implanted VW-MPSCs. Our results suggest that VW-MPSCs are of relevance for vascular morphogenesis, repair and self-renewal of vascular wall cells and for local capacity of neovascularization in disease processes.

  13. Detection of optimum maturity of maize using image processing and ...

    African Journals Online (AJOL)

    A CCD camera for image acquisition of the different green colorations of the maize leaves at maturity was used. Different color features were extracted from the image processing system (MATLAB) and used as inputs to the artificial neural network that classify different levels of maturity. Keywords: Maize, Maturity, CCD ...

  14. Beyond maturity

    International Nuclear Information System (INIS)

    Tessmer, W.B.

    1990-01-01

    The Nuclear Power Plant Simulator Industry has undergone to decades of evolution in experience, technology and business practices. Link-Miles Simulation Corporation (LMSC) has been contracted to build 68 Full Scope Nuclear Simulators during the 1970's and 1980's. Traditional approaches to design, development and testing have been used to satisfy specifications for initial customer requirements. However, the Industry has matured. All U.S. Nuclear Utilities own, or have under contract, at least one simulator. Other industrial nations have centralized training facilities to satisfy the simulator training needs. The customer of the future is knowledgeable and experienced in the development and service of nuclear simulators. The role of the simulator vendor is changing in order to alter the traditional approach for development. Covenants between the vendors and their customers solidify new complementary roles. This paper presents examples of current simulator project development with recommendations for future endeavors

  15. Early changes of the pH of the apoplast are different in leaves, stem and roots of Vicia faba L. under declining water availability.

    Science.gov (United States)

    Karuppanapandian, T; Geilfus, C-M; Mühling, K-H; Novák, O; Gloser, V

    2017-02-01

    Changes in pH of the apoplast have recently been discussed as an important factor in adjusting transpiration and water relations under conditions of drought via modulatory effect on abscisic acid (ABA) concentration. Using Vicia faba L., we investigated whether changes in the root, shoot and leaf apoplastic pH correlated with (1) a drought-induced reduction in transpiration and with (2) changes in ABA concentration. Transpiration, leaf water potential and ABA in leaves were measured and correlated with root and shoot xylem pH, determined by a pH microelectrode, and pH of leaf apoplast quantified by microscopy-based in vivo ratiometric analysis. Results revealed that a reduction in transpiration rate in the early phase of soil drying could not be linked with changes in the apoplastic pH via effects on the stomata-regulating hormone ABA. Moreover, drought-induced increase in pH of xylem or leaf apoplast was not the remote effect of an acropetal transport of alkaline sap from root, because root xylem acidified during progressive soil drying, whereas the shoot apoplast alkalized. We reason that other, yet unknown signalling mechanism was responsible for reduction of transpiration rate in the early phase of soil drying. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Comparison of Sensitivity to Photoinhibition and UV-B Stress between Developing and Mature Leaves of Red Pepper (Capsicum annuum L.) Plants from Control and Gamma-Irradiated Seeds

    International Nuclear Information System (INIS)

    Kim, J.H.; Baek, M.H.; Chung, B.Y.; Kim, J.S.; Lee, Y.B.

    2004-01-01

    The stress-resistance of red pepper (Capsicum annuum L. cv. Yeomyung and Joheung) plants from the seeds irradiated with low doses of gamma-radiation (2, 4, 8, and 16 Gy) was examined under the conditions of photoinhibition and UV-B stress. To induce photoinhibition, the leaves acclimated overnight with a dim light were exposed to a photon flux density (PFD) of 200 μmol · m-² · s-¹ at 25℃ for 1 h. Then, they were further exposed to the same PFD with supplementary UV-B irradiance at 25℃ for 3 h (UV-B stress). The gamma-irradiation stimulated the early growth of the plants in both cultivars at 2, 4, and 8 Gy

  17. Maturation of the auditory system in clinically normal puppies as reflected by the brain stem auditory-evoked potential wave V latency-intensity curve and rarefaction-condensation differential potentials.

    Science.gov (United States)

    Poncelet, L C; Coppens, A G; Meuris, S I; Deltenre, P F

    2000-11-01

    To evaluate auditory maturation in puppies. Ten clinically normal Beagle puppies. Puppies were examined repeatedly from days 11 to 36 after birth (8 measurements). Click-evoked brain stem auditory-evoked potentials (BAEP) were obtained in response to rarefaction and condensation click stimuli from 90 dB normal hearing level to wave V threshold, using steps of 10 dB. Responses were added, providing an equivalent to alternate polarity clicks, and subtracted, providing the rarefaction-condensation differential potential (RCDP). Steps of 5 dB were used to determine thresholds of RCDP and wave V. Slope of the low-intensity segment of the wave V latency-intensity curve was calculated. The intensity range at which RCDP could not be recorded (ie, pre-RCDP range) was calculated by subtracting the threshold of wave V from threshold of RCDP RESULTS: Slope of the wave V latency-intensity curve low-intensity segment evolved with age, changing from (mean +/- SD) -90.8 +/- 41.6 to -27.8 +/- 4.1 micros/dB. Similar results were obtained from days 23 through 36. The pre-RCDP range diminished as puppies became older, decreasing from 40.0 +/- 7.5 to 20.5 +/- 6.4 dB. Changes in slope of the latency-intensity curve with age suggest enlargement of the audible range of frequencies toward high frequencies up to the third week after birth. Decrease in the pre-RCDP range may indicate an increase of the audible range of frequencies toward low frequencies. Age-related reference values will assist clinicians in detecting hearing loss in puppies.

  18. Effects of drying pretreatment and particle size adjustment on the composting process of discarded flue-cured tobacco leaves.

    Science.gov (United States)

    Zhao, Gui-Hong; Yu, Yan-Ling; Zhou, Xiang-Tong; Lu, Bin-Yu; Li, Zi-Mu; Feng, Yu-Jie

    2017-05-01

    The main characteristic of discarded flue-cured tobacco leaves is their high nicotine content. Aerobic composting is an effective method to decrease the nicotine level in tobacco leaves and stabilize tobacco wastes. However, high levels of nicotine in discarded flue-cured tobacco leaves complicate tobacco waste composting. This work proposes a drying pretreatment process to reduce the nicotine content in discarded flue-cured tobacco leaves and thus enhance its carbon-to-nitrogen ratio to a suitable level for composting. The effect of another pretreatment method, particle size adjustment, on composting efficiency was also tested in this work. The results indicated that the air-dried (nicotine content: 1.35%) and relatively long discarded flue-cured tobacco leaves (25 mm) had a higher composting efficiency than damp (nicotine content: 1.57%) and short discarded flue-cured tobacco leaves (15 mm). When dry/25 mm discarded flue-cured tobacco leaves mixed with tobacco stems in an 8:2 ratio was composted at a temperature above 55 °C for 9 days, the nicotine content dropped from 1.29% to 0.28%. Since the discarded flue-cured tobacco leaves was successfully composted to a fertile and harmless material, the germination index values increased to 85.2%. The drying pretreatment and particle size adjustment offered ideal physical and chemical conditions to support microbial growth and bioactivity during the composting process, resulting in efficient conversion of discarded flue-cured tobacco leaves into a high quality and mature compost.

  19. The maturation and germination of Phytophthora ramorum Chlamydospores

    Science.gov (United States)

    Aaron L. Smith; Everett M. Hansen

    2008-01-01

    Chlamydospores are a distinctive feature of Phytophthora ramorum. They are formed quickly in agar, and within colonized leaves. We followed their development and maturation in vitro and in vivo, and studied conditions affecting their germination. Cell walls of mature P. ramorum chlamydospores...

  20. Quantificação de ácido alfa-linolênico em caules e folhas de linho (Linum usitatissimum L. colhidos em diferentes estágios de desenvolvimento Quantification of alpha-linolenic acid in stems and leaves of flax (Linum usitatissimum L. harvested in different stages of development

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Aguiar

    2010-12-01

    Full Text Available O objetivo deste estudo foi quantificar o ácido alfa-linolênico [LNA, 18:3 (n-3], avaliar a composição centesimal das folhas e caules de linho (Linum usitatissimum L. submetidos à secagem e colhidos em diferentes estágios de desenvolvimento (40, 80 e 120 dias, e determinar o potencial antioxidante das folhas colhidas aos 80 dias através do teste com o radical DPPH. As folhas obtiveram maiores teores de cinzas, proteína e lipídios totais em relação aos caules. Tanto as folhas quanto os caules apresentaram razões de AGPI/AGS e n-6/n-3 dentro dos valores considerados adequados para a alimentação. Os caules colhidos nos diferentes tempos não apresentaram diferenças significativas (PThe objective of this study was to quantify the alpha-linolenic acid [LNA, 18:3 (n-3] and to evaluate the proximate composition of leaves and stems of flax (Linum usitatissimum L. dried and harvested at different stages of development (40, 80 and 120 days, and to determine the antioxidant potential of the leaf harvested at 80 days using the test of DPPH radical. The leaves had higher levels of ash, protein and total lipids when compared to the stems. Both the leaves as the stems had ratios of PUFA/SFA and n-6/n-3 within the values considered suitable for food. Stems in the different stages showed no significant difference (P<0.05 of LNA content. Leaves harvested at 80 days showed the highest concentration of LNA, corresponding to 1,262.36 mg/100g dried leaf. The different extracts (methanol, butanol, acetate and water were efficient in the inhibition of DPPH radical, with emphasis on the butanolic and acetate fractions and the values of IC50 were approximately 42 ppm. These results highlight the nutritional potential and antioxidant activity of leaves and stems of flaxseed for future use in the animal and human feeding.

  1. Maturity and maturity models in lean construction

    Directory of Open Access Journals (Sweden)

    Claus Nesensohn

    2014-03-01

    Full Text Available In recent years there has been an increasing interest in maturity models in management-related disciplines; which reflects a growing recognition that becoming more mature and having a model to guide the route to maturity can help organisations in managing major transformational change. Lean Construction (LC is an increasingly important improvement approach that organisations seek to embed. This study explores how to apply the maturity models to LC. Hence the attitudes, opinions and experiences of key industry informants with high levels of knowledge of LC were investigated. To achieve this, a review of maturity models was conducted, and data for the analysis was collected through a sequential process involving three methods. First a group interview with seven key informants. Second a follow up discussion with the same individuals to investigate some of the issues raised in more depth. Third an online discussion held via LinkedIn in which members shared their views on some of the results. Overall, we found that there is a lack of common understanding as to what maturity means in LC, though there is general agreement that the concept of maturity is a suitable one to reflect the path of evolution for LC within organisations.

  2. Slab replacement maturity guidelines.

    Science.gov (United States)

    2014-04-01

    This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

  3. Structure and function of stem cell pools in mammalian cell renewal systems

    International Nuclear Information System (INIS)

    Fliedner, T.M.; Nothdurft, W.

    1979-01-01

    Stem cells play a key-role in the maintenance of the equilibrium between cell loss and cell production in cell renewal systems as well as in the understanding of the radiation pathophysiology of mammalian organisms. The integrity of mammalian organisms with the need to maintain a constant ''millieu interior'' is depending on the normal functioning of cell renewal systems, especially those of epithelial surfaces and blood cell forming organs. All cell renewal systems of bodies have a very similar functional structure consisting of functional, proliferative - amplifying and stem cell compartments. They differ in transit and cell cycle times and in the number of amplification division - aside from the difference in their functional and biochemical make-up. The stem cell pools are providing the cells capable of differentiation without depleting their own kind. This can be achieved by symmetrical or assymmetrical stem cell division. In normal steady state, 50% of the stem cell division remain in the stem cell pool, while the other 50% leave it to differentiate, proliferate and mature, hemopoietic system is distributed throughout bodies. This is an important factor in the radiation biology of mammalian organisms since the loss of function in one area can be compensated for by more production in other areas, and locally depleted sites can be reseeded with the stem cells migrating in from blood. (Yamashita, S.)

  4. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  5. Alfalfa stem tissues: Cell wall deposition, composition, and degradability

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.

    2002-01-01

    Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue

  6. Absorption and translocation of phosphorus-32 in guava leaves

    International Nuclear Information System (INIS)

    Natale, William

    1997-01-01

    Phosphorus is easily absorbed by the leaves and translocated. The objective of this work was to evaluate the absorption and translocation of P by guava leaves, with time. When a solution containing 2% MAP and specific activity 0.15 μCi/ml was applied. MAP labelled with 32 P was applied in the 3 rd pair of leaves. These and other leaves, roots and stem were collected separately and analyzed accordingly. The results showed that 20 days after application 12% of the applied P was absorbed by the guava leaves. The translocation of P started immediately after its absorption reaching 20% 2fter 20 days. (author). 19 refs., 4 tabs

  7. Parental Leave in Denmark

    DEFF Research Database (Denmark)

    Rostgaard, Tine; Christoffersen, Mogens; Weise, Hanne

    This artcle considders the political aims for different leave schemes and reviews studies af these schemes. The use of parental leave is sensitive to the financial loss involved in taking leave: a decrease in the benefit payments has had a significant influence on take-up, while, in general, fami......, families'' loss of income is less if leave is taken up by the mothers. Only few fathers participate in parental leave....

  8. Metabolite modifications in Solanum lycopersicum roots and leaves ...

    African Journals Online (AJOL)

    During the treatment, Cd accumulated significantly in the roots compared to stems and leaves. Plant growth (root, stem and leaf) decreased when Cd concentration increased. The analysis of 1H-NMR spectra of polar extracts showed clear differences between metabolites amounts (soluble sugars, organic and amino acids) ...

  9. ORGANIZATIONAL PROJECT MANAGEMENT MATURITY

    Directory of Open Access Journals (Sweden)

    Yana Derenskaya

    2017-11-01

    Full Text Available The present article is aimed at developing a set of recommendations for achieving a higher level of organizational project maturity at a given enterprise. Methodology. For the purposes of the current research, the available information sources on the components of project management system are analysed; the essence of “organizational maturity” and the existing models of organizational maturity are studied. The method of systemic and structural analysis, as well as the method of logical generalization, are employed in order to study the existing models of organizational maturity, to describe levels of organizational maturity, and finally to develop a set of methodological recommendations for achieving a higher level of organizational project maturity at a given enterprise. The results of the research showed that the core elements of project management system are methodological, organizational, programtechnical, and motivational components. Project management encompasses a wide range of issues connected with organizational structure, project team, communication management, project participants, etc. However, the fundamental basis for developing project management concept within a given enterprise starts with defining its level of organizational maturity. The present paper describes various models of organizational maturity (staged, continuous, petal-shaped and their common types (H. Кеrzner Organizational Maturity Model, Berkeley PM Maturity Model, Organizational Project Management Maturity Model, Portfolio, Program & Project Management Maturity Model. The analysis of available theoretic works showed that the notion “organizational project maturity” refers to the capability of an enterprise to select projects and manage them with the intention of achieving its strategic goals in the most effective way. Importantly, the level of maturity can be improved by means of formalizing the acquired knowledge, regulating project-related activities

  10. Trace element accumulation and distribution in sunflower plants at the stages of flower bud and maturity

    Directory of Open Access Journals (Sweden)

    Susanna De Maria

    2013-02-01

    Full Text Available The aim of this study was to analyze the accumulation and distribution of cadmium (Cd, zinc (Zn and copper (Cu in different portions of plants of sunflower (Helianthus annuus L., cv. Oleko grown in soil with contaminants (5, 300, 400 mg kg–1 of Cd, Zn and Cu, respectively and without (untreated soil as a control from the emergence of cotyledon leaves until to two phenological stages: flower bud (R-1 and maturity (R- 9. Sunflower accumulated considerable amounts of heavy metals in both phenological stages showing slight reductions of dry matter production. At R-1 stage, Cd, Zn and Cu were accumulated mainly in the roots with concentrations respectively up to 5.4, 233 and 160 mg kg–1 of dry matter with a low translocation from roots to the aerial part. Yet at the R-1 stage, the bioconcentration factor (BCF of Cd showed a significantly higher value in the Cd-Zn-Cu treatment (0.27 with respect to the untreated control (0.02, vice versa was observed for Cu, whereas no significant difference between treatments was observed for Zn (0.12 on average. However among metals, Cd showed the highest value of BCF. Referring only to the epigeous portion, differences in the accumulation and distribution of the three metals in the treated plants were found in both phenological stages; indeed passing from flower bud to the maturity stage, Cd, Zn and Cu concentrations increased in the stems and leaves, particularly in the old ones, whereas decreased in the heads. Metal accumulation in the achenes was very low and never exceed the toxicity threshold value considered for livestock. The high storage of heavy metals in roots and the probable re-translocation of the three metals along the plant during the growing cycle could be considered as a strategy of sunflower to preserve young metabolically-active leaves and reproductive organs from toxic metal concentrations.

  11. [Modeling polarimetric BRDF of leaves surfaces].

    Science.gov (United States)

    Xie, Dong-Hui; Wang, Pei-Juan; Zhu, Qi-Jiang; Zhou, Hong-Min

    2010-12-01

    The purpose of the present paper is to model a physical polarimetric bidirectional reflectance distribution function (pBRDF), which can character not only the non-Lambertian but also the polarized features in order that the pBRDF can be applied to analyze the relationship between the degree of polarization and the physiological and biochemical parameters of leaves quantitatively later. Firstly, the bidirectional polarized reflectance distributions from several leaves surfaces were measured by the polarized goniometer developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The samples of leaves include two pieces of zea mays L. leaves (young leaf and mature leaf) and a piece of E. palcherrima wild leaf. Non-Lambertian characteristics of directional reflectance from the surfaces of these three leaves are obvious. A Cook-Torrance model was modified by coupling the polarized Fresnel equations to simulate the bidirectional polarized reflectance properties of leaves surfaces. The three parameters in the modified pBRDF model, such as diffuse reflectivity, refractive index and roughness of leaf surface were inversed with genetic algorithm (GA). It was found that the pBRDF model can fit with the measured data well. In addition, these parameters in the model are related with both the physiological and biochemical properties and the polarized characteristics of leaves, therefore it is possible to build the relationships between them later.

  12. Goodbye, Mandatory Maternity Leaves

    Science.gov (United States)

    Nation's Schools, 1972

    1972-01-01

    In precedent-setting decrees, courts and federal and State authorities have branded compulsory maternity leaves either unconstitutional or illegal. School administrators are urged to prod boards of education to adopt more lenient maternity leave policies -- now. (Author)

  13. Leaving home in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard

    2015-01-01

    The paper focuses on ethnic differences in the timing and patterns of leaving the parental home. Leaving home is a key transition in the life course of the individual, and extensive research has been conducted on the timing and patterns of leaving it. However, ethnic differences in these patterns...... of leaving home. Results showed that while some differences disappeared when controlling for covariates, others persisted, thus indicating ethnic differences in home-leaving patterns. A strong link between leaving home and marriage was substantiated for Turks, but not for Somalis. The home-leaving patterns...... of Somalis were much more similar to those of Danes. Overall, Turkish descendants were similar to Turkish immigrants but with some differentiation. The analyses identified the existence of ethnic differences in home-leaving patterns but also found evidence of a shift towards less traditional patterns, i...

  14. Generation of an induced pluripotent stem cell (iPSC line from a patient with maturity-onset diabetes of the young type 13 (MODY13 with a the potassium inwardly-rectifying channel, subfamily J, member 11 (KCNJ11 mutation

    Directory of Open Access Journals (Sweden)

    Frank Griscelli

    2017-08-01

    Full Text Available Heterozygous activating mutation (p.Glu227Lys in KCNJ11 leads to maturity-onset diabetes of the young (MODY type 13, that is a subtype of dominant inherited young-onset non-autoimmune diabetes due to a primary defect in pancreatic beta cells. We generated induced pluripotent stem cells (iPSCs from a patient with KCNJ11p.Glu227Lys mutation who developed MODY at 13 years old. KCNJ11p.Glu227Lys-mutated cells that were reprogrammed by non-integrative viral transduction had normal karyotype, harboured the KCNJ11p.Glu227Lys mutation, expressed pluripotency hallmarks and had the differentiation capacity into the three germ layers.

  15. What make them leave and where do they go?

    DEFF Research Database (Denmark)

    Ulriksen, Lars; Madsen, Lene Møller; Holmegaard, Henriette Tolstrup

    2015-01-01

    This chapter presents the results of a quantitative analysis of national data covering Danish students who in the period 1995-2009 completed an uppersecondary school programme and entered a higher-education science, technology, engineering or mathematics (STEM) programme. The analysis focuses...... chance of a male or female student entering a STEM programme. The results suggest that female students are more affected by achieving a high grade-point average and by the educational background of their parents than are the male students. The relative risk of non-completion is higher for women than...... on identifying variables that change the hazard ratio for (1) entering a STEM programme and (2) leaving a STEM programme without completing it. Finally, the chapter explores (3) the destinations of students who leave a STEM higher-education programme. It is found that there has been no change in the relative...

  16. Maturity of the PWR

    International Nuclear Information System (INIS)

    Bacher, P.; Rapin, M.; Aboudarham, L.; Bitsch, D.

    1983-03-01

    Figures illustrating the predominant position of the PWR system are presented. The question is whether on the basis of these figures the PWR can be considered to have reached maturity. The following analysis, based on the French program experience, is an attempt to pinpoint those areas in which industrial maturity of the PWR has been attained, and in which areas a certain evolution can still be expected to take place

  17. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  18. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  19. Caracterización de acelga fresca de Santiago del Estero (Argentina. Comparación del contenido de nutrientes en hoja y tallo. Evaluación de los carotenoides presentes Characterization of fresh Beta vulgaris from Santiago del Estero (Argentina. Nutrient and caroteniod content of stem and leaves

    Directory of Open Access Journals (Sweden)

    Sara Macías de Costa

    2003-04-01

    Full Text Available Se realizaron estudios de caracterización integral de acelga (Beta vulgaris, var. cycla cultivada en la Provincia de Santiago del Estero, Argentina. Por tratarse de un vegetal de importante consumo regional, se realizó la determinación de sus constituyentes básicos, minerales y pigmentos para conocer los valores nutricionales que aporta este alimento en nuestra región. Se analizaron comparando hoja y tallo: humedad, cenizas, proteínas, grasas, hidratos de carbono utilizables, fibra dietaria total, contenido de clorofila y carotenoides. En cuanto a minerales, se determinaron calcio, magnesio, sodio, potasio, manganeso, zinc, hierro, fósforo y boro. Se encontraron diferencias en los aportes de minerales, proteínas, grasas y fibra entre hoja y tallo, así como también el contenido de carotenoides exclusivamente en las hojas. Los resultados marcan importantes diferencias en el contenido energético y en su valor provitamínico A entre la hoja y el tallo de este vegetal, mostrando que este último es una parte aprovechable de la planta, recomendable en dietas hipocalóricas.An integrated characterization study of Swiss chard grown in Santiago del Estero, Argentina, was carried out. As Swiss chard is a vegetable of important regional consumption, the determination of its basic constituents, minerals and pigments was done to appraise the nutritional value offered by this food in our area. Moisture, ash content, proteins, fats, available carbohydrates, total dietary fiber, chlorophylls and carotenoids were analysed, comparing the leaves and the stems. As to minerals, calcium, magnesium, sodium, manganese, zinc, iron, phosphorous, potassium, and boron were determined. Differences in the concentration of minerals, proteins, fats and fiber between the leaves and the stems were found, as well as the carotenoid content mainly in the leaves. These findings revealed important differences in energy content and provitamin A value, showing that the stem

  20. The Temporary Leave Dilemma -

    DEFF Research Database (Denmark)

    Amilon, Anna

    2010-01-01

    Lone mothers have to take care of a sick child with little or no help from the child’s other parent and have to carry all costs connected to leave-taking. This paper empirically tests whether lone mothers take more temporary parental leave to care for sick children than partnered mothers...... and whether parental leave is associated with a signaling cost. The results from this study of Swedish mothers show that lone mothers use more temporary parental leave than partnered mothers. Further, within the group of lone mothers, those with higher socioeconomic status take less temporary parental leave...... than those with lower socioeconomic status, whereas no such differences are found within the group of partnered mothers. One possible interpretation is that signaling costs negatively influence the utilization of temporary parental leave for lone mothers....

  1. Women in STEM hit by discrimination

    Science.gov (United States)

    Randall, Ian

    2016-02-01

    Almost a third of women in science, technology, engineering and mathematics (STEM) in Australia are considering leaving their job within the next five years, according to a survey by the employee association Professionals Australia.

  2. Distribuição da matéria seca e composição química das raízes, caule e folhas de goiabeira submetida a estresse salino Dry matter partitioning and mineral composition of roots, stems and leaves of guava grown under salt stress conditions

    Directory of Open Access Journals (Sweden)

    Raimundo Gonçalves Ferreira

    2001-01-01

    , but decreased in stems and leaves. The K content was reduced with the increased levels of salinity, particularly in the leaves. On the other hand, Mg levels were not affected by salinity in stems and roots but decreased in the leaves. There was a positive relationship between Na and Cl and a negative relationship between Na and K concentration in roots and leaves. Mg concentration in leaves and roots did not vary with the concentration of Na. The concentration of Ca did not vary with Na in the leaves but showed an inverse relationship in the roots.

  3. Age, allocation and availability of nonstructural carbon in mature red maple trees.

    Science.gov (United States)

    Carbone, Mariah S; Czimczik, Claudia I; Keenan, Trevor F; Murakami, Paula F; Pederson, Neil; Schaberg, Paul G; Xu, Xiaomei; Richardson, Andrew D

    2013-12-01

    The allocation of nonstructural carbon (NSC) to growth, metabolism and storage remains poorly understood, but is critical for the prediction of stress tolerance and mortality. We used the radiocarbon ((14) C) 'bomb spike' as a tracer of substrate and age of carbon in stemwood NSC, CO2 emitted by stems, tree ring cellulose and stump sprouts regenerated following harvesting in mature red maple trees. We addressed the following questions: which factors influence the age of stemwood NSC?; to what extent is stored vs new NSC used for metabolism and growth?; and, is older, stored NSC available for use? The mean age of extracted stemwood NSC was 10 yr. More vigorous trees had both larger and younger stemwood NSC pools. NSC used to support metabolism (stem CO2 ) was 1-2 yr old in spring before leaves emerged, but reflected current-year photosynthetic products in late summer. The tree ring cellulose (14) C age was 0.9 yr older than direct ring counts. Stump sprouts were formed from NSC up to 17 yr old. Thus, younger NSC is preferentially used for growth and day-to-day metabolic demands. More recently stored NSC contributes to annual ring growth and metabolism in the dormant season, yet decade-old and older NSC is accessible for regrowth. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  4. Proteomics Coupled with Metabolite and Cell Wall Profiling Reveal Metabolic Processes of a Developing Rice Stem Internode

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fan; Williams, Brad J.; Thangella, Padmavathi A. V.; Ladak, Adam; Schepmoes, Athena A.; Olivos, Hernando J.; Zhao, Kangmei; Callister, Stephen J.; Bartley, Laura E.

    2017-07-13

    Internodes of grass stems function in mechanical support, transport, and, in some species, are a major sink organ for carbon in the form of cell wall polymers. This study reports cell wall composition, proteomic and metabolite analyses of the rice elongating internode. Along eight segments of the second rice internode (internode II) at booting stage, cellulose, lignin, and xylose increase as a percentage of cell wall material from the younger to the older internode segments, indicating active cell wall synthesis. Liquid-chromatography tandem mass spectrometry (LC-MS/MS) of trypsin-digested peptides of size-fractionated proteins extracted from this internode at booting reveals 2547proteins with at least two unique peptides. The dataset includes many glycosyltransferases, acyltransferases, glycosyl hydrolases, cell wall-localized proteins, and protein kinases that have or may have functions in cell wall biosynthesis or remodeling. Phospho-enrichment of the internode II peptides identified 21 unique phosphopeptides belonging to 20 phosphoproteins including an LRR-III family receptor like kinase. GO over-representation and KEGG pathway analyses highlight the abundances of internode proteins involved in biosynthetic processes, especially the synthesis of secondary metabolites such as phenylpropanoids and flavonoids. LC-MS of hot methanol-extracted secondary metabolites from internode II at four stages (elongation, early mature, mature and post mature) indicates that secondary metabolites in stems are distinct from those of roots and leaves, and differ during stem maturation. This work fills a void of knowledge of proteomics and metabolomics data for grass stems, specifically for rice, and provides baseline knowledge for more detailed studies of cell wall synthesis and other biological processes during internode development, toward improving grass agronomic properties.

  5. Phytochemical screening and antimicrobial activity of roots, stem ...

    African Journals Online (AJOL)

    The roots, stem-bark and leaves of Grewia mollis which is used as herbal remedies for the cure of diarrhea and dysentery by natives in northern part of Nigeria were studied. The ethanol and water extracts of roots, stem-bark and leaves of the plant were subjected to phytochemical screening and antimicrobial activity against ...

  6. Asset Stripping in a Mature Market Economy

    DEFF Research Database (Denmark)

    Klarskov Jeppesen, Kim; Møller, Ulrik Gorm

    2011-01-01

    Purpose – The purpose of this paper is to document a Danish fraud scheme, in which a large number of limited companies were stripped of their assets leaving them with nothing but tax debt, eventually causing the Danish Tax and Customs Administration to lose large sums. Furthermore, the purpose...... indicates that asset stripping may take place in mature market economies to the extent that perpetrators are able to circumvent the corporate governance system by giving lawyers, public accountants and banks incentives to act less critically towards dubious business transactions. Research limitations...

  7. Long Maturity Forward Rates

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2001-01-01

    The paper aims to improve the knowledge of the empirical properties of the long maturity region of the forward rate curve. Firstly, the theoretical negative correlation between the slope at the long end of the forward rate curve and the term structure variance is recovered empirically and found...... to be statistically significant. Secondly, the expectations hypothesis is analyzed for the long maturity region of the forward rate curve using "forward rate" regressions. The expectations hypothesis is numerically close to being accepted but is statistically rejected. The findings provide mixed support...... for the affine term structure model....

  8. Stem Cell, Regenerative Medicine and Cancer | Center for Cancer Research

    Science.gov (United States)

    Of the estimated trillion cells that build up our bodies, only a little number can self-renew and give rise to many different cell types. These unspecialized cells are called stem cells. Stem cell division and differentiation is fundamental to the development of the mature organism. Stem cells have recently attracted significant attention largely due to their potential medical

  9. Grammar Maturity Model

    NARCIS (Netherlands)

    Zaytsev, V.; Pierantonio, A.; Schätz, B.; Tamzalit, D.

    2014-01-01

    The evolution of a software language (whether modelled by a grammar or a schema or a metamodel) is not limited to development of new versions and dialects. An important dimension of a software language evolution is maturing in the sense of improving the quality of its definition. In this paper, we

  10. Maturing interorganisational information systems

    NARCIS (Netherlands)

    Plomp, M.G.A.|info:eu-repo/dai/nl/313946809

    2012-01-01

    This thesis consists of nine chapters, divided over five parts. PART I is an introduction and the last part contains the conclusions. The remaining, intermediate parts are: PART II: Developing a maturity model for chain digitisation. This part contains two related studies concerning the development

  11. Jealousy and Moral Maturity.

    Science.gov (United States)

    Mathes, Eugene W.; Deuger, Donna J.

    Jealousy may be perceived as either good or bad depending upon the moral maturity of the individual. To investigate this conclusion, a study was conducted testing two hypothesis: a positive relationship exists between conventional moral reasoning (reference to norms and laws) and the endorsement and level of jealousy; and a negative relationship…

  12. Phloem unloading in developing leaves of sugar beet

    International Nuclear Information System (INIS)

    Schmalstig, J.G.

    1985-01-01

    Physiological and transport data support a symplastic pathway for phloem unloading in developing leaves of sugar beet (Beta vulgaris L. Klein E, multigerm). The sulfhydryl inhibitor parachloromercuribenzene sulfonic acid (PCMBS) inhibited uptake of [ 14 C]-sucrose added to the free space of developing leaves, but did not affect import of [ 14 C]-sucrose during steady-state 14 CO 2 labeling of a source leaf. The passively-transported xenobiotic sugar, [ 14 C]-L-glucose did not readily enter mesophyll cells when supplied through the cut end of the petiole of a sink leaf as determined by whole leaf autoradiography. In contrast, [ 14 C]-L-glucose translocated through the phloem from a mature leaf, rapidly entered mesophyll cells, and was evenly distributed between mesophyll and veins. Autoradiographs of developing leaves following a pulse of 14 CO 2 to a source leaf revealed rapid passage of phloem translocated into progressively higher order veins as the leaf developed. Entry into V order veins occurred during the last stage of import through the phloem. Import into developing leaves was inhibited by glyphosate (N-phosphomethylglycine), a herbicide which inhibits the aromatic amino acid pathway and hence protein synthesis. Glyphosate also stopped net starch accumulation in sprayed mature leaves, but did not affect export of carbon from treated leaves during the time period that import into developed leaves was inhibited

  13. Falling for Clay Leaves.

    Science.gov (United States)

    Kernan, Christine

    2002-01-01

    Describes an art project that integrated science and art education. Explains that students create ceramic bowls by using real leaves. Discusses the process of creating the ceramic bowls, including how to glaze the bowls. Includes a list of materials. (CMK)

  14. Maternity Leave Policies

    Science.gov (United States)

    Strang, Lucy; Broeks, Miriam

    2017-01-01

    Abstract Over recent years many European Union countries have made changes to the design of the maternity leave provision. These policy developments reflect calls for greater gender equality in the workforce and more equal share of childcare responsibilities. However, while research shows that long period of leave can have negative effects on women's labour market attachment and career advancements, early return to work can be seen as a factor preventing exclusive breastfeeding, and therefore, potentially having negative health impacts for babies. Indeed, the World Health Organisation recommends exclusive breastfeeding up to 6 months of age to provide babies with the nutrition for healthy growth and brain development, protection from life-threatening ailments, obesity and non-communicable diseases such as asthma and diabetes. Therefore, labour market demands on women may be at odds with the health benefits for children gained by longer periods of maternity leave. The aim of this article is to examine the relationship between leave provision and health benefits for children. We examine maternity and parental leave provision across European countries and its potential impact on the breastfeeding of very young babies (up to 6-months of age). We also consider economic factors of potential extension of maternity leave provision to 6 months, such as costs to businesses, effects on the female labour market attachment, and wider consequences (benefits and costs) for individuals, families, employers and the wider society. PMID:28983432

  15. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  16. Biomass production and essential oil yield from leaves, fine stems and resprouts using pruning the crown of Aniba canelilla (H.B.K. (Lauraceae in the Central Amazon Produção de biomassa e rendimento de óleo essencial de folhas, galhos finos e rebrotas utilizando poda da copa de Aniba canelilla (H.B.K. (Lauraceae na Amazônia Central

    Directory of Open Access Journals (Sweden)

    Adriana Pellegrini Manhães

    2012-09-01

    Full Text Available Aniba canelilla (H.B.K. Mez. is a tree species from Amazon that produces essential oil. The oil extraction from its leaves and stems can be an alternative way to avoid the tree cutting for production of essential oil. The aim of this study was to analyse factors that may influence the essential oil production and the biomass of resprouts after pruning the leaves and stems of A. canelilla trees. The tree crowns were pruned in the wet season and after nine months the leaves and stems of the remaining crown and the resprouts were collected, in the dry season. The results showed that the essential oil yield and chemical composition differed among the stems, leaves and resprouts. The stems' essential oil production differed between the seasons and had a higher production in the resprouting stems than the old stems of the remaining crown. The production of essential oil and leaf biomass of resprouts were differently related to the canopy openness, indicating that light increases the production of the essential oil and decreases the biomass of resprouting leaves. This study revealed that plant organs differ in their essential oil production and that the canopy openness must be taken into account when pruning the A. canelilla tree crown in order to achieve higher oil productivity.Aniba canelilla (H.B.K. Mez. é uma espécie arbórea da Amazônia que produz óleo essencial. A extração do óleo de suas folhas e galhos pode ser uma forma alternativa de evitar a derrubada do tronco para sua produção de óleo essencial. O objetivo deste estudo foi analisar os fatores que podem influenciar a produção de óleo essencial e sua biomassa da rebrota após a poda de folhas e galhos das árvores de A. canelilla. As copas das árvores foram podadas na estação chuvosa e, após nove meses, as folhas e os galhos da copa remanescente e da rebrota foram coletadas na estação seca. Os resultados mostraram que o rendimento e a composição química de

  17. People Capability Maturity Model. SM.

    Science.gov (United States)

    1995-09-01

    tailored so it consumes less time and resources than a traditional software process assessment or CMU/SEI-95-MM-02 People Capability Maturity Model...improved reputation or customer loyalty. CMU/SEI-95-MM-02 People Capability Maturity Model ■ L5-17 Coaching Level 5: Optimizing Activity 1...Maturity Model CMU/SEI-95-MM-62 Carnegie-Mellon University Software Engineering Institute DTIC ELECTE OCT 2 7 1995 People Capability Maturity

  18. Hypoxia and Stem Cell-Based Engineering of Mesenchymal Tissues

    OpenAIRE

    Ma, Teng; Grayson, Warren L.; Fröhlich, Mirjam; Vunjak-Novakovic, Gordana

    2009-01-01

    Stem cells have the ability for prolonged self-renewal and differentiation into mature cells of various lineages, which makes them important cell sources for tissue engineering applications. Their remarkable ability to replenish and differentiate in vivo is regulated by both intrinsic and extrinsic cellular mechanisms. The anatomical location where the stem cells reside, known as the “stem cell niche or microenvironment,” provides signals conducive to the maintenance of definitive stem cell p...

  19. Maturity effects in energy futures

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos (Calgary Univ., AB (CA). Dept. of Economics)

    1992-04-01

    This paper examines the effects of maturity on future price volatility and trading volume for 129 energy futures contracts recently traded in the NYMEX. The results provide support for the maturity effect hypothesis, that is, energy futures prices to become more volatile and trading volume increases as futures contracts approach maturity. (author).

  20. Toxicological evaluation of methanol leaves extract of Vernonia ...

    African Journals Online (AJOL)

    of hepatocytes, peripheral cramped chromatin, shrinkages (single cell death) of hepatocytes, fragmentation of hepatocytes while no histopathological changes were ... of the stem- bark, the roots, and the leaves of V. amyg- dalina are also reported to be ... Mice of the same sex were grouped into. 8 experimental and 1 control ...

  1. Formation of 14C-asparagine from 14C-precursor in mulberry leaves

    International Nuclear Information System (INIS)

    Yamashita, Tadaaki

    1981-01-01

    Since a remarkable accumulation of asparagine in the young leaves of mulberry has been observed, the formation of 14 C-asparagine from 14 C-labeled substrates in young leaves was examined in comparison with that in the mature leaves. 14 C-aspartic acid and 14 C-succinic acid expected as active precursors for asparagine biosynthesis, and 14 C-sucrose as respiratory substrates were fed respectively to the disks of young or mature leaves of mulberry. Although 14 C-succinic acid was actively converted to 14 C-asparagine, no significant amount of 14 C-asparagine was formed from 14 C-aspartic acid in two hours of feeding period. The rate of formation of 14 C-asparagine from 14 C-succinic acid in the mature leaves was slightly higher than that in the young leaves. Amino acids other than asparagine acquired 14 C from 14 C-labeled substrates were mainly aspartic acid, glutamic acid, alanine and ν-amino butyric acid in both of the leaves. Intending to accelerate the formation of asparagine in the leaves, ammonium ion was supplied to culturing solution as only source of nitrogen and plants were grown for two weeks in that solution before 14 C-labeled substrates feeding experiments. Supplying of ammonium ion brought about enhanced accumulation of asparagine in the young leaves, and caused remarkable formation of 14 C-asparagine from 14 C-aspartic acid in both of the leaves. However, the rate of 14 C-asparagine formation from 14 C-aspartic acid in the young leaves did not exceed that in the mature leaves. (author)

  2. TRAVEL AND HOME LEAVE

    CERN Multimedia

    Human Resources Division

    2002-01-01

    Administrative procedures for : Travel to the home station and home leave (hl) Additional travel to the home station (at) Travel to the home station and home leave for family reasons (hlf) As part of the process of simplifying administrative procedures, HR and AS Divisions have devised a new, virtually automatic procedure for payment of travel expenses to the home station. The changes are aimed at rationalising administrative procedures and not at reducing benefits. The conditions of eligibility are unchanged. The new procedure, which will be operational with effect from 1st June 2002, will greatly simplify the administrative processing of claims for travel expenses and the recording of home leaves. Currently, requests for payment are introduced manually into the Advances and Claims system (AVCL) by divisional secretariats. All travel to the home station starting prior to 1st June 2002 will be processed according to the existing system whereas that starting on 1st June and after will be processed accordi...

  3. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    Yeast surface display is an effective tool for antibody affinity maturation because yeast can be used as an all-in-one workhorse to assemble, display and screen diversified antibody libraries. By employing the natural ability of yeast Saccharomyces cerevisiae to efficiently recombine multiple DNA...... laboratory conditions. A particular emphasis was put on using molecular techniques in conjunction with microenvironmental measurements (O2, pH, irradiance), a combination that is rarely found but provides a much more detailed understanding of “cause and effect” in complex natural systems...

  4. Stem cells

    NARCIS (Netherlands)

    Jukes, Jojanneke; Both, Sanne; Post, Janine; van Blitterswijk, Clemens; Karperien, Marcel; de Boer, Jan; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter defines stem cells and their properties. It identifies the major differences between embryonic and adult stem cells. Stem cells can be defined by two properties: the ability to make identical copies of themselves and the ability to form other cell types of the body. These properties are

  5. Characterization of Sugar Contents and Sucrose Metabolizing Enzymes in Developing Leaves of Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Jinheng Zhu

    2018-02-01

    Full Text Available Sucrose-metabolizing enzymes in plant leaves have hitherto been investigated mainly in temperate plants, and rarely conducted in tandem with gene expression and sugar analysis. Here, we investigated the sugar content, gene expression, and the activity of sucrose-metabolizing enzymes in the leaves of Hevea brasiliensis, a tropical tree widely cultivated for natural rubber. Sucrose, fructose and glucose were the major sugars detected in Hevea leaves at four developmental stages (I to IV, with starch and quebrachitol as minor saccharides. Fructose and glucose contents increased until stage III, but decreased strongly at stage IV (mature leaves. On the other hand, sucrose increased continuously throughout leaf development. Activities of all sucrose-cleaving enzymes decreased markedly at maturation, consistent with transcript decline for most of their encoding genes. Activity of sucrose phosphate synthase (SPS was low in spite of its high transcript levels at maturation. Hence, the high sucrose content in mature leaves was not due to increased sucrose-synthesizing activity, but more to the decline in sucrose cleavage. Gene expression and activities of sucrose-metabolizing enzymes in Hevea leaves showed striking differences compared with other plants. Unlike in most other species where vacuolar invertase predominates in sucrose cleavage in developing leaves, cytoplasmic invertase and sucrose synthase (cleavage direction also featured prominently in Hevea. Whereas SPS is normally responsible for sucrose synthesis in plant leaves, sucrose synthase (synthesis direction was comparable or higher than that of SPS in Hevea leaves. Mature Hevea leaves had an unusually high sucrose:starch ratio of about 11, the highest reported to date in plants.

  6. Stem secondary growth of tundra shrubs

    DEFF Research Database (Denmark)

    Campioli, Matteo; Leblans, Niki; Michelsen, Anders

    2012-01-01

    Our knowledge of stem secondary growth of arctic shrubs (a key component of tundra net primary production, NPP) is very limited. Here, we investigated the impact of the physical elements of the environment on shrub secondary growth by comparing annual growth rates of model species from similar...... growth (stem apical growth, stem length, and apical growth of stem plus leaves), in some cases even with opposite responses. Thus caution should be taken when estimating the impact of the environment on shrub growth from apical growth only. Integration of our data set with the (very limited) previously...

  7. Does Leave Work?

    NARCIS (Netherlands)

    Heleen van Luijn; Saskia Keuzenkamp

    2004-01-01

    More and more people have to combine work and care responsibilities, and work part-time or use daycare and after-school care facilities to help them do so. The Work and Care Act, which came into force on 1 December 2001, combined all the existing schemes - such as parental and maternity leave -

  8. Maternity Leave in Taiwan

    Science.gov (United States)

    Feng, Joyce Yen; Han, Wen-Jui

    2010-01-01

    Using the first nationally representative birth cohort study in Taiwan, this paper examines the role that maternity leave policy in Taiwan plays in the timing of mothers returning to work after giving birth, as well as the extent to which this timing is linked to the amount of time mothers spend with their children and their use of breast milk…

  9. REMINDER: Saved Leave Scheme (SLS)

    CERN Multimedia

    2003-01-01

    Transfer of leave to saved leave accounts Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'* annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that unused leave of all those taking part in the saved leave scheme at the closure of the leave year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2003 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they ar...

  10. Overexpression of Arabidopsis VIT1 increases accumulation of iron in cassava roots and stems.

    Science.gov (United States)

    Narayanan, Narayanan; Beyene, Getu; Chauhan, Raj Deepika; Gaitán-Solis, Eliana; Grusak, Michael A; Taylor, Nigel; Anderson, Paul

    2015-11-01

    Iron is extremely abundant in the soil, but its uptake in plants is limited due to low solubility in neutral or alkaline soils. Plants can rely on rhizosphere acidification to increase iron solubility. AtVIT1 was previously found to be involved in mediating vacuolar sequestration of iron, which indicates a potential application for iron biofortification in crop plants. Here, we have overexpressed AtVIT1 in the starchy root crop cassava using a patatin promoter. Under greenhouse conditions, iron levels in mature cassava storage roots showed 3-4 times higher values when compared with wild-type plants. Significantly, the expression of AtVIT1 showed a positive correlation with the increase in iron concentration of storage roots. Conversely, young leaves of AtVIT1 transgenic plants exhibit characteristics of iron deficiency such as interveinal chlorosis of leaves (yellowing) and lower iron concentration when compared with the wild type plants. Interestingly, the AtVIT1 transgenic plants showed 4 and 16 times higher values of iron concentration in the young stem and stem base tissues, respectively. AtVIT1 transgenic plants also showed 2-4 times higher values of iron content when compared with wild-type plants, with altered partitioning of iron between source and sink tissues. These results demonstrate vacuolar iron sequestration as a viable transgenic strategy to biofortify crops and to help eliminate micronutrient malnutrition in at-risk human populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Correlation between dental maturity and cervical vertebral maturity.

    Science.gov (United States)

    Chen, Jianwei; Hu, Haikun; Guo, Jing; Liu, Zeping; Liu, Renkai; Li, Fan; Zou, Shujuan

    2010-12-01

    The aim of this study was to investigate the association between dental and skeletal maturity. Digital panoramic radiographs and lateral skull cephalograms of 302 patients (134 boys and 168 girls, ranging from 8 to 16 years of age) were examined. Dental maturity was assessed by calcification stages of the mandibular canines, first and second premolars, and second molars, whereas skeletal maturity was estimated by the cervical vertebral maturation (CVM) stages. The Spearman rank-order correlation coefficient was used to measure the association between CVM stage and dental calcification stage of individual teeth. The mean chronologic age of girls was significantly lower than that of boys in each CVM stage. The Spearman rank-order correlation coefficients between dental maturity and cervical vertebral maturity ranged from 0.391 to 0.582 for girls and from 0.464 to 0.496 for boys (P cervical vertebral maturation stage. The development of the mandibular second molar in females and that of the mandibular canine in males had the strongest correlations with cervical vertebral maturity. Therefore, it is practical to consider the relationship between dental and skeletal maturity when planning orthodontic treatment. Copyright © 2010 Mosby, Inc. All rights reserved.

  12. Mature Cystic Renal Teratoma

    International Nuclear Information System (INIS)

    Yavuz, Alpaslan; Ceken, Kagan; Alimoglu, Emel; Akkaya, Bahar

    2014-01-01

    Teratomas are rare germline tumors that originate from one or more embryonic germ cell layers. Teratoma of the kidney is extremely rare, and less than 30 cases of primary intrarenal teratomas have been published to date. We report the main radiologic features of an unusual case of mature cystic teratoma arising from the left kidney in a two-year-old boy. A left-sided abdominal mass was detected on physical examination and B-Mod Ultrasound (US) examination revealed a heterogeneous mass with central cystic component. Computed tomography (CT) demonstrated a lobulated, heterogeneous, hypodense mass extending craniocaudally from the splenic hilum to the level of the left iliac fossa. Nephrectomy was performed and a large, fatty mass arising from the left kidney was excised. The final pathologic diagnosis was confirmed as cystic renal teratoma

  13. Developing maturity grids for assessing organisational capabilities

    DEFF Research Database (Denmark)

    Maier, Anja; Moultrie, James; Clarkson, P John

    2009-01-01

    Keyword: Maturity Model,Maturity Grid,Maturity Matrix,Organisational Capabilities,Benchmarking,New Product Development,Perfirmance Assessment......Keyword: Maturity Model,Maturity Grid,Maturity Matrix,Organisational Capabilities,Benchmarking,New Product Development,Perfirmance Assessment...

  14. Modeling non-maturing liabilities

    OpenAIRE

    von Feilitzen, Helena

    2011-01-01

    Non‐maturing liabilities, such as savings accounts, lack both predetermined maturity and reset dates due to the fact that the depositor is free to withdraw funds at any time and that the depository institution is free to change the rate. These attributes complicate the risk management of such products and no standardized solution exists. The problem is important however since non‐maturing liabilities typically make up a considerable part of the funding of a bank. In this report different mode...

  15. Clerkship maturity: does the idea of training clinical skills work?

    Science.gov (United States)

    Stosch, Christoph; Joachim, Alexander; Ascher, Johannes

    2011-01-01

    With the reformed curriculum "4C", the Medical Faculty of the University of Cologne has started to systematically plan practical skills training, for which Clerkship Maturity is the first step. The key guidelines along which the curriculum was development were developed by experts. This approach has now been validated. Both students and teachers were asked to fill in a questionnaire regarding preclinical practical skills training to confirm the concept of Clerkship Maturity. The Cologne training program Clerkship Maturity can be validated empirically overall through the activities of the students awaiting the clerkship framework and through the evaluation by the medical staff providing the training. The subjective ratings of the advantages of the training by the students leave room for improvement. Apart from minor improvements to the program, the most likely solution providing sustainable results will involve an over-regional strategy for establishing skills training planned as part of the curriculum.

  16. Dehydrin expression in seeds and maturation drying: a paradigm change.

    Science.gov (United States)

    Radwan, A; Hara, M; Kleinwächter, M; Selmar, D

    2014-09-01

    Dehydrins are well known for being expressed in leaves during the course of developmental processes as well as under drought stress, being part of the protective machinery. Moreover, in seed physiology, dehydrins are classified as late embryogenesis-related proteins (LEA protein), where they are thought to be responsible for persistence and longevity of seeds. Although both topics are a focus of modern plant biology, a direct linkage between these both areas is generally lacking. Based on an alignment of the chain of events, this paper will help to generate understanding that the occurrence of dehydrins in maturing seeds and leaves suffering drought stress is part of the same basic principle: basic principle: dehydrins are expressed in response to water shortage. Unfortunately, the related developmental process in seeds, i.e. maturation drying, has not been adequately considered as a part of this process. As a corresponding implication, the chain of events must be adjusted: the differences in dehydrin expression in orthodox, intermediate and recalcitrant seeds could be directly attributed to the occurrence or absence of maturation drying. The differences in dehydrin expression in orthodox, intermediate and recalcitrant seeds, and thus the differences in longevity, could be attributed to the occurrence or absence of a maturation drying. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

    Directory of Open Access Journals (Sweden)

    MARCUS VINICIUS SANDOVAL PAIXÃO

    2016-01-01

    Full Text Available ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: 100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid resulted on avocado plants of better quality. The use of IBA (2000 mg L-1 does not affect the rooting and growth of avocado's multi-stem plants.

  18. Maturation curves of sweet sorghum genotypes

    Directory of Open Access Journals (Sweden)

    Renan Silva e Souza

    2016-02-01

    Full Text Available ABSTRACT Sweet sorghum [Sorghum bicolor (L. Moench] stands out as a complementary crop to sugarcane Saccharum spp. for the production of ethanol, since it has juicy stems with directly fermentable sugars. Due to this fact, there is a need for the analysis of sweet sorghum properties in order to meet the agro-industry demand. This work aimed to develop and study the maturation curves of seven sweet sorghum cultivars in ten harvest dates. The results showed a significant difference between cultivars and harvest dates for all parameters analysed (p≤0.01. Regarding the sugar content, the cultivars BRS508, XBWS80147 and CMSX629 showed the highest means for the total reducing sugars (TRS and recoverable sugar (RS. In the production of ethanol per tonne of biomass (EP, the cultivars BRS508 and CMSX629 presented the best results.

  19. What's So Special about STEM? A Comparison of Women's Retention in STEM and Professional Occupations.

    Science.gov (United States)

    Glass, Jennifer L; Sassler, Sharon; Levitte, Yael; Michelmore, Katherine M

    2013-01-01

    We follow female college graduates in the National Longitudinal Survey of Youth 1979 and compare the trajectories of women in science, technology, engineering, and mathematics (STEM)-related occupations to other professional occupations. Results show that women in STEM occupations are significantly more likely to leave their occupational field than professional women, especially early in their career, while few women in either group leave jobs to exit the labor force. Family factors cannot account for the differential loss of STEM workers compared to other professional workers. Few differences in job characteristics emerge either, so these cannot account for the disproportionate loss of STEM workers. What does emerge is that investments and job rewards that generally stimulate field commitment, such as advanced training and high job satisfaction, fail to build commitment among women in STEM.

  20. Employer Provisions for Parental Leave.

    Science.gov (United States)

    Meisenheimer, Joseph R., II

    1989-01-01

    Slightly more than one-third of full-time employees in medium and large firms in private industry were covered by maternity- or paternity-leave policies; days off were usually leave without pay. (Author)

  1. Whose Maturity is it Anyway?

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi; Mukkamala, Raghava Rao

    2017-01-01

    This paper presents results from an ongoing empirical study that seeks to understand the influence of different quantitative methods on the design and assessment of maturity models. Although there have been many academic publications on maturity models, there exists a significant lack of understa...

  2. Logging damage to residual trees following commercial harvesting to different overstory retention levels in a mature hardwood stand in Tennessee

    Science.gov (United States)

    Wayne K. Clatterbuck

    2006-01-01

    Partial cutting in mature hardwood stands often causes physical damage to residual stems through felling and skidding resulting in a decline in bole quality and subsequent loss of tree value. This study assessed the logging damage to residual trees following commercial harvesting in a fully stocked, mature oak-hickory stand cut to three overstory basal area retention...

  3. REMINDER Saved Leave Scheme (SLS) : Transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2002-01-01

    Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'*) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that, since last year, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2002 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they are still participants in the schem...

  4. Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22 B) can be transferred to the saved leave account at the end of the leave year (30 September). Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the ...

  5. Crystal Macropattern Development in Prunus serotina (Rosaceae, Prunoideae) Leaves

    OpenAIRE

    LERSTEN, NELS R.; HORNER, HARRY T.

    2006-01-01

    • Background and Aims Prunus, subgenus Padus, exhibits two completely different calcium oxalate crystal macropatterns in mature leaves. Foliar macropattern development has been described previously in P. virginiana, representing one version. Prunus serotina, in the group exhibiting the second macropattern, is described here. The goal was to describe developmental details for comparison with P. virginiana, and to extend the sparse current knowledge of crystal macropatterns.

  6. STEM Education.

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-08-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

  7. What’s So Special about STEM? A Comparison of Women’s Retention in STEM and Professional Occupations

    OpenAIRE

    Glass, Jennifer L.; Sassler, Sharon; Levitte, Yael; Michelmore, Katherine M.

    2013-01-01

    We follow female college graduates in the National Longitudinal Survey of Youth 1979 and compare the trajectories of women in science, technology, engineering, and mathematics (STEM)-related occupations to other professional occupations. Results show that women in STEM occupations are significantly more likely to leave their occupational field than professional women, especially early in their career, while few women in either group leave jobs to exit the labor force. Family factors cannot ac...

  8. Isolation of Astilbin from Leaves of Cratoxylum Arborescens

    International Nuclear Information System (INIS)

    Samsiah Jusoh; Samsiah Jusoh; Zuriati Zakaria; Laily Din

    2013-01-01

    Phytochemicals studies was conducted on the leaves of Cratoxylum arborescens that has been collected from Post Brooke, Gua Musang, Kelantan, Malaysia. Traditionally, latex of the stem bark of C. arborescens is being used for the treatment of wound. Extraction of leaves of C. arborescens using organic solvents followed by purification using standard procedure of purification yielded known compound, astilbin. This compound was identified by NMR spectral data using various 2D-techniques and comparison with the literature data. Reports showed that this compound has a unique immunosuppressive activity, a selective inhibition against activated T lymphocytes. This characteristic of astilbin is beneficial for the treatment of human immune diseases. (author)

  9. Parental leave and child health.

    Science.gov (United States)

    Ruhm, C J

    2000-11-01

    This study investigates whether rights to parental leave improve pediatric health. Aggregate data are used for 16 European countries over the 1969 through 1994 period. More generous paid leave is found to reduce deaths of infants and young children. The magnitudes of the estimated effects are substantial, especially where a causal effect of leave is most plausible. In particular, there is a much stronger negative relationship between leave durations and post-neonatal or child fatalities than for perinatal mortality, neonatal deaths, or low birth weight. The evidence further suggests that parental leave may be a cost-effective method of bettering child health.

  10. Human embryonic stem cells handbook

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Redi

    2013-03-01

    Full Text Available After the Nobel prize in physiology or medicine was awarded jointly to Sir John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent it became imperative to write down the review for a book entirely devoted to human embryonic stem cells (hES, those cells that are a urgent need for researchers, those cells that rekindle the ethical debates and finally, last but not least, those cells whose study paved the way to obtain induced pluripotent stem cells by the OSKC’s Yamanaka method (the OSKC acronim refers, for those not familiar with the topic, to the four stemness genes used to transfect somatic fibroblasts: Oct4, Sox2, Klf4 and c-Myc....

  11. The prevalence of sick leave

    DEFF Research Database (Denmark)

    Backhausen, Mette; Damm, Peter; Bendix, Jane

    2018-01-01

    of long-term sick leave. Method Data from 508 employed pregnant women seeking antenatal care was collected by questionnaires from August 2015 to March 2016. The questionnaires, which were filled in at 20 and 32 weeks of gestation, provided information on maternal characteristics, the number of days spent...... on sick leave and the associated reasons. Descriptive statistics and logistic regression analysis were applied. Results The prevalence of sick leave was 56% of employed pregnant women in the first 32 weeks of gestation and more than one in four reported long-term sick leave (>20 days, continuous...... was a negative predictor. Conclusions The prevalence of sick leave was 56% in the first 32 weeks of gestation and more than one in four women reported long-term sick leave. The majority of reasons for sick leave were pregnancy-related and low back pain was the most frequently given reason....

  12. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  13. Effect of Plant Age on the Quantity and Quality of Proteins Extracted from Sugar Beet (Beta vulgaris L.) Leaves

    NARCIS (Netherlands)

    Kiskini, Alexandra; Vissers, Anne; Vincken, Jean Paul; Gruppen, Harry; Wierenga, Peter Alexander

    2016-01-01

    Effects of the developmental stage (e.g., young, mature, or senescent) of leaves on their chemical composition have been described in the literature. This study focuses on the variation in chemical composition and quantity and quality of proteins extracted from leaves due to variation in plant

  14. Paid Family Leave, Fathers' Leave-Taking, and Leave-Sharing in Dual-Earner Households

    OpenAIRE

    Bartel, Ann P.; Rossin-Slater, Maya; Ruhm, Christopher J.; Stearns, Jenna; Waldfogel, Jane

    2015-01-01

    This paper provides quasi-experimental evidence on the impact of paid leave legislation on fathers' leave-taking, as well as on the division of leave between mothers and fathers in dual-earner households. Using difference-in-difference and difference-in-difference-in-difference designs, we study California's Paid Family Leave (CA-PFL) program, which is the first source of government-provided paid parental leave available to fathers in the United States. Our results show that fathers in Califo...

  15. Wnt signaling in the stem cell niche

    NARCIS (Netherlands)

    Rattis, Frédérique Marie; Voermans, Carlijn; Reya, Tannishtha

    2004-01-01

    All the cells present in the blood are derived from the hematopoietic stem cell (HSC). Because mature blood cells have a limited life span, HSCs must perpetuate themselves through self-renewal to maintain a functional hematopoietic compartment for the lifetime of an organism. This review focuses on

  16. Paid Family Leave, Fathers' Leave-Taking, and Leave-Sharing in Dual-Earner Households.

    Science.gov (United States)

    Bartel, Anne P; Rossin-Slater, Maya; Ruhm, Christopher J; Stearns, Jenna; Waldfogel, Jane

    Using difference-in-difference and difference-in-difference-in-difference designs, we study California's Paid Family Leave (CA-PFL) program, the first source of government-provided paid parental leave available to fathers in the Unites States. Relative to the pre-treatment mean, fathers of infants in California are 46 percent more likely to be on leave when CA-PFL is available. In households where both parents work, we find suggestive evidence that CA-PFL increases both father-only leave-taking (i.e., father on leave while mother is at work) and joint leave-taking (i.e., both parents on leave at the same time). Effects are larger for fathers of first-born children than for fathers of later-born children.

  17. Pharmacognostic evaluation of the leaves and stem-bark of ...

    African Journals Online (AJOL)

    The microscopy revealed the dorsiventral nature of the leaf and was observed to be hypostomatic with anomocytic type of stomata, with numerous unicellular covering and glandular trichomes on the abaxial surface. Chemomicroscopic characters present include; lignin, starch, cellulose, tannin, suberin and calcium oxalate ...

  18. Modeling of desorption of Alfalfa (Medicago sativa) stems and leaves.

    NARCIS (Netherlands)

    ArabHosseini, A.; Huisman, W.; Müller, J.

    2011-01-01

    The equilibrium moisture content of agricultural products is necessary to optimize drying process and helps to keep the quality of the product during the period of storage. The main aim of this research was to find the best model which could define well, the exchange of moisture between alfalfa

  19. Phytochemical and antimicrobial studies on the leaves and stem of ...

    African Journals Online (AJOL)

    Administrator

    2006-08-25

    Aug 25, 2006 ... powdered material weighing 79 g was packed into a soxhlet extractor and ... loop to transfer a strand of the organism into the plate followed by ... distilled water which was swirled and mixed thoroughly by heating to allow ... solution was then mixed gently with molten double strength nutrient agar in a ...

  20. Molluscicidal Activity of Aqueous Extract of Leaves, Stem Back and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2018-03-23

    Mar 23, 2018 ... medium, provided the original work is properly cited. Dates: Received: 19 ... of Africa, the Middle East and South Asia. It is ... Bauchi. This work is designed to determine .... the lowest molluscicides within and after 24 hours of.

  1. Pharmacognostic evaluation of the leaves and stem bark of ...

    African Journals Online (AJOL)

    The epidermal walls are straight with distinctively shaped calcium oxalate crystals clustered in the row of parenchymatous cells. The starch grains are of varying sizes and contains eccentric helium. The trichomes are uniserrate and the fibre is spindle – shaped. Chemomicroscopy revealed the presence of cellulose, lignin, ...

  2. Pharmacognostic Investigation of the Leaves and Stems of ...

    African Journals Online (AJOL)

    Erah

    Tropical Journal of Pharmaceutical Research, December 2009; 8 (6): 557-566. © Pharmacotherapy ... The periderm was four-layered followed by homogenous .... in width. The adaxial surface was smooth and .... scalariform perforation plate.

  3. Slab replacement maturity guidelines : [summary].

    Science.gov (United States)

    2014-04-01

    Concrete sets in hours at moderate temperatures, : but the bonds that make concrete strong continue : to mature over days to years. However, for : replacement concrete slabs on highways, it is : crucial that concrete develop enough strength : within ...

  4. SOUL System Maturation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to advance the maturity of an innovative Spacecraft on Umbilical Line (SOUL) System suitable for a wide variety of applications of interest...

  5. SOUL System Maturation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to advance the maturity of an innovative Spacecraft on Umbilical Line (SOUL) System suitable for a wide variety of applications of interest...

  6. Maturation of sugar maple seed

    Science.gov (United States)

    Clayton M., Jr. Carl; Albert G., Jr. Snow; Albert G. Snow

    1971-01-01

    The seeds of a sugar maple tree (Acer saccharum Marsh.) do not mature at the same time every year. And different trees mature their seeds at different times. So time of year is not a reliable measure of when seeds are ripe. Better criteria are needed. In recent studies we have found that moisture content and color are the best criteria for judging when sugar maple...

  7. STEM Education

    Science.gov (United States)

    & Development (LDRD) National Security Education Center (NSEC) Office of Science Programs Richard P Databases National Security Education Center (NSEC) Center for Nonlinear Studies Engineering Institute Scholarships STEM Education Programs Teachers (K-12) Students (K-12) Higher Education Regional Education

  8. Barley HvPAPhy_a as transgene provides high and stable phytase activities in mature barley straw and in grains

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Madsen, Claus Krogh

    2017-01-01

    The phytase purple acid phosphatase (HvPAPhy_a) expressed during barley seed development was evaluated as transgene for overexpression in barley. The phytase was expressed constitutively driven by the cauliflower mosaic virus 35S-promoter, and the phytase activity was measured in the mature grains......, the green leaves and in the dry mature vegetative plant parts left after harvest of the grains. The T2-generation of HvPAPhy_a transformed barley showed phytase activity increases up to 19-fold (29 000 phytase units (FTU) per kg in mature grains). Moreover, also in green leaves and mature dry straw, phytase...... activities were increased significantly by 110-fold (52 000 FTU/kg) and 57-fold (51 000 FTU/kg), respectively. The HvPAPhy_a-transformed barley plants with high phytase activities possess triple potential utilities for the improvement of phosphate bioavailability. First of all, the utilization of the mature...

  9. Description and biology of two new species of Neotropical Liriomyza Mik (Diptera, Agromyzidae, mining leaves of Bocconia (Papaveraceae

    Directory of Open Access Journals (Sweden)

    Stephanie Boucher

    2014-01-01

    Full Text Available Liriomyza mystica Boucher & Nishida, sp. n., and Liriomyza prompta Boucher & Nishida, sp. n. are described from Costa Rica. Both species were reared from leaves of Bocconia frutescens L. (Papaveraceae. The latter species was also reared from B. arborea S. Watson. Larvae of L. mystica mine primary veins of large, relatively old, mature leaves, and L. prompta mine blades of small to large, mature leaves. These represent the first record of agromyzids feeding on Bocconia. Biological information is also given and illustrated.

  10. [Precautionary maternity leave in Tirol].

    Science.gov (United States)

    Ludescher, K; Baumgartner, E; Roner, A; Brezinka, C

    1998-01-01

    Under Austrian law, precautionary maternity leave is a decree issued by the district public health physician. It forbids a pregnant woman to work and mandates immediate maternity leave. Regular maternity leave for all women employed in all jobs begins at 32 weeks of gestation. Women who work in workplaces deemed dangerous and women with a history of obstetric problems such as premature or growth-retarded babies from previous pregnancies are regularly 'sent' into precautionary maternity leave. The public health physicians of Tirol's nine administrative districts were interviewed and supplied data on precautionary maternity leave from their districts. In 100 women who attended the clinic for pregnancies at risk of the Obstetrics/Gynecology Department of Innsbruck University Hospital and who had already obtained precautionary maternity leave, the medical/administrative procedure was studied in each case and correlated with pregnancy outcome. The town district of Innsbruck and the district that comprises the suburbs of the provincial capital had the highest rates of precautionary maternity leave. The town district of Innsbruck had a rate of 24.3% of all pregnant women (employed and not employed) in precautionary maternity leave in 1997, whereas the whole province of Tirol had 13.4%. More than 80% of decrees for precautionary maternity leave are issued by district public health physicians on the basis of written recommendations from gynecologists. One third of women who are sent into precautionary maternity leave are issued the decree prior to 12 weeks of gestation - mostly cases of multiple pregnancies and women with previous miscarriages. The present system of precautionary maternity leave appears to work in the sense that most working pregnant women with risk factors are correctly identified - with most errors on the side of caution. As the system also helps employers - the employee's pay is paid from the federal family support fund and state insurance once she is in

  11. Ossification score is a better indicator of maturity related changes in eating quality than animal age.

    Science.gov (United States)

    Bonny, S P F; Pethick, D W; Legrand, I; Wierzbicki, J; Allen, P; Farmer, L J; Polkinghorne, R J; Hocquette, J-F; Gardner, G E

    2016-04-01

    Ossification score and animal age are both used as proxies for maturity-related collagen crosslinking and consequently decreases in beef tenderness. Ossification score is strongly influenced by the hormonal status of the animal and may therefore better reflect physiological maturity and consequently eating quality. As part of a broader cross-European study, local consumers scored 18 different muscle types cooked in three ways from 482 carcasses with ages ranging from 590 to 6135 days and ossification scores ranging from 110 to 590. The data were studied across three different maturity ranges; the complete range of maturities, a lesser range and a more mature range. The lesser maturity group consisted of carcasses having either an ossification score of 200 or less or an age of 987 days or less with the remainder in the greater maturity group. The three different maturity ranges were analysed separately with a linear mixed effects model. Across all the data, and for the greater maturity group, animal age had a greater magnitude of effect on eating quality than ossification score. This is likely due to a loss of sensitivity in mature carcasses where ossification approached and even reached the maximum value. In contrast, age had no relationship with eating quality for the lesser maturity group, leaving ossification score as the more appropriate measure. Therefore ossification score is more appropriate for most commercial beef carcasses, however it is inadequate for carcasses with greater maturity such as cull cows. Both measures may therefore be required in models to predict eating quality over populations with a wide range in maturity.

  12. Parental Leave Policies and Parents' Employment and Leave-Taking

    Science.gov (United States)

    Han, Wen-Jui; Ruhm, Christopher; Waldfogel, Jane

    2009-01-01

    We describe trends in maternal employment and leave-taking after birth of a newborn and analyze the extent to which these behaviors are influenced by parental leave policies. Data are from the June Current Population Survey (CPS) Fertility Supplements, merged with other months of the CPS, and cover the period 1987 to 1994. This time span is one…

  13. Nutrient allocation among stem, leaf and inflorescence of jatropha plants

    Directory of Open Access Journals (Sweden)

    Rosiane L. S. de Lima

    2015-08-01

    Full Text Available ABSTRACTInformation on the partitioning of nutrients among various organs in jatropha plants, as a complementary tool for the recommendation of fertilization, is still not available. This study aimed to evaluate the contents of macro and micronutrients in stems, leaves and inflorescences of jatropha branches at the beginning of flowering. At the beginning of flowering, adult jatropha plants were sampled and divided into five compartments: inflorescences, leaves from vegetative branches, leaves from flowering branches, stems from vegetative branches and stems from flowering branches. Jatropha inflorescences are a drain of nutrients. Leaves are important sources of nutrients demanded by the inflorescences at the beginning of flowering. The higher allocation of nutrients in the inflorescences suggests the need for preventive/corrective fertilizations, which must be performed at least 30 days before flowering, providing plants with nutrients in adequate amounts for a good yield.

  14. REMINDER Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2)Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the interest of all parties concerned. This automatic transfer procedure has a number of advantages for participants in the SLS scheme. First, staff members will no longer have to take any administrative steps. Secondly, the new proced...

  15. Sustaining Exploration in Mature Basins

    International Nuclear Information System (INIS)

    Bayo, A.

    2002-01-01

    Exploration is a business like any other business driven by opportunity, resources and expectation of profit. Therefore, exploration will thrive anywhere the opportunities are significant, the resources are available and the outlook for profit (or value creation) is good. To sustain exploration activities anywhere, irrespective of the environment, there must be good understanding of the drivers of these key investment criteria. This paper will examine these investment criteria as they relate to exploration business and address the peculiarity of exploration in mature basin. Mature basins are unique environment that lends themselves a mix of fears, paradigms and realities, particularly with respect to the perception of value. To sustain exploration activities in a mature basin, we need to understand these perceptions relative to the true drivers of profitability. Exploration in the mature basins can be as profitable as exploration in emerging basins if the dynamics of value definition-strategic and fiscal values are understood by operators, regulators and co ventures alike. Some suggestions are made in this presentation on what needs to be done in addressing these dynamic investment parameters and sustaining exploration activities in mature basins

  16. Seasonal patterns of reserve and soluble carbohydrates in mature sugar maple (Acer saccharum)

    Science.gov (United States)

    B.L. Wong; K.L. Baggett; A.H. Rye

    2003-01-01

    Sugar maple (Acer saccharum Marsh.) trees exhibit seasonal patterns of production, accumulation, and utilization of nonstructural carbohydrates that are closely correlated with phenological events and (or) physiological processes. The simultaneous seasonal patterns of both reserve and soluble carbohydrates in the leaves, twigs, branches, and trunks of healthy mature...

  17. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...

  18. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    2014-01-01

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...

  19. Expression of a Petunia inflata pectin methyl esterase in Solanum tuberosum L. enhances stem elongation and modifies cation distribution.

    Science.gov (United States)

    Pilling, J; Willmitzer, L; Fisahn, J

    2000-02-01

    Transgenic potato (Solanum tuberosum L.) plants were constructed with a Petunia inflata-derived cDNA encoding a pectin methyl esterase (PME; EC 3.1.1.11) in sense orientation under the control of the cauliflower mosaic virus 35S promoter. The PME activity was elevated in leaves and tubers of the transgenic lines but slightly reduced in apical segments of stems from mature plants. Stem segments from the base of juvenile PME-overexpressing plants did not differ in PME activity from the control, whereas in apical parts PME was less active than in the wild-type. During the early stages of development stems of these transgenic plants elongated more rapidly than those of the wild-type. Further evidence that overexpression of a plant-derived PME has an impact on plant development is based on modifications of tuber yield, which was reduced in the transgenic lines. Cell walls from transgenic tubers showed significant differences in their cation-binding properties in comparison with the wild-type. In particular, cell walls displayed increased affinity for sodium and calcium, while potassium binding was constant. Furthermore, the total ion content of transgenic potatoes was modified. Indications of PME-mediated differences in the distribution of ions in transgenic plants were also obtained by monitoring relaxations of the membrane potential of roots subsequent to changes in the ionic composition of the bathing solution. However, no effects on the chemical structure of pectin from tuber cell walls could be detected.

  20. Public Sector IS Maturity Models

    DEFF Research Database (Denmark)

    Zinner Henriksen, Helle; Andersen, Kim Normann; Medaglia, Rony

    2011-01-01

    Online applications and processing of tax forms, driver licenses, and construction permits are examples of where policy attention and research have been united in efforts aiming to categorize the maturity level of e-services. Less attention has been attributed to policy areas with continuous online...... citizenpublic interaction, such as in public education. In this paper we use a revised version of the Public Sector Process Rebuilding (PPR) maturity model for mapping 200 websites of public primary schools in Denmark. Findings reveal a much less favorable picture of the digitization of the Danish public sector...... compared to the high ranking it has received in the international benchmark studies. This paper aims at closing the gap between the predominant scope of maturity models and the frequency of citizen-public sector interaction, and calls for increased attention to the activities of government where the scale...

  1. Hematopoietic Stem and Progenitor Cells as Effectors in Innate Immunity

    Directory of Open Access Journals (Sweden)

    Jennifer L. Granick

    2012-01-01

    Full Text Available Recent research has shed light on novel functions of hematopoietic stem and progenitor cells (HSPC. While they are critical for maintenance and replenishment of blood cells in the bone marrow, these cells are not limited to the bone marrow compartment and function beyond their role in hematopoiesis. HSPC can leave bone marrow and circulate in peripheral blood and lymph, a process often manipulated therapeutically for the purpose of transplantation. Additionally, these cells preferentially home to extramedullary sites of inflammation where they can differentiate to more mature effector cells. HSPC are susceptible to various pathogens, though they may participate in the innate immune response without being directly infected. They express pattern recognition receptors for detection of endogenous and exogenous danger-associated molecular patterns and respond not only by the formation of daughter cells but can themselves secrete powerful cytokines. This paper summarizes the functional and phenotypic characterization of HSPC, their niche within and outside of the bone marrow, and what is known regarding their role in the innate immune response.

  2. Bicarbonate Transport During Enamel Maturation.

    Science.gov (United States)

    Yin, Kaifeng; Paine, Michael L

    2017-11-01

    Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.

  3. Engineering Hydrogel Microenvironments to Recapitulate the Stem Cell Niche.

    Science.gov (United States)

    Madl, Christopher M; Heilshorn, Sarah C

    2018-06-04

    Stem cells are a powerful resource for many applications including regenerative medicine, patient-specific disease modeling, and toxicology screening. However, eliciting the desired behavior from stem cells, such as expansion in a naïve state or differentiation into a particular mature lineage, remains challenging. Drawing inspiration from the native stem cell niche, hydrogel platforms have been developed to regulate stem cell fate by controlling microenvironmental parameters including matrix mechanics, degradability, cell-adhesive ligand presentation, local microstructure, and cell-cell interactions. We survey techniques for modulating hydrogel properties and review the effects of microenvironmental parameters on maintaining stemness and controlling differentiation for a variety of stem cell types. Looking forward, we envision future hydrogel designs spanning a spectrum of complexity, ranging from simple, fully defined materials for industrial expansion of stem cells to complex, biomimetic systems for organotypic cell culture models.

  4. Drought-Induced Effects on Nitrate Reductase Activity and mRNA and on the Coordination of Nitrogen and Carbon Metabolism in Maize Leaves1

    Science.gov (United States)

    Foyer, Christine H.; Valadier, Marie-Hélène; Migge, Andrea; Becker, Thomas W.

    1998-01-01

    Maize (Zea mays L.) plants were grown to the nine-leaf stage. Despite a saturating N supply, the youngest mature leaves (seventh position on the stem) contained little NO3− reserve. Droughted plants (deprived of nutrient solution) showed changes in foliar enzyme activities, mRNA accumulation, photosynthesis, and carbohydrate and amino acid contents. Total leaf water potential and CO2 assimilation rates, measured 3 h into the photoperiod, decreased 3 d after the onset of drought. Starch, glucose, fructose, and amino acids, but not sucrose (Suc), accumulated in the leaves of droughted plants. Maximal extractable phosphoenolpyruvate carboxylase activities increased slightly during water deficit, whereas the sensitivity of this enzyme to the inhibitor malate decreased. Maximal extractable Suc phosphate synthase activities decreased as a result of water stress, and there was an increase in the sensitivity to the inhibitor orthophosphate. A correlation between maximal extractable foliar nitrate reductase (NR) activity and the rate of CO2 assimilation was observed. The NR activation state and maximal extractable NR activity declined rapidly in response to drought. Photosynthesis and NR activity recovered rapidly when nutrient solution was restored at this point. The decrease in maximal extractable NR activity was accompanied by a decrease in NR transcripts, whereas Suc phosphate synthase and phosphoenolpyruvate carboxylase mRNAs were much less affected. The coordination of N and C metabolism is retained during drought conditions via modulation of the activities of Suc phosphate synthase and NR commensurate with the prevailing rate of photosynthesis. PMID:9576798

  5. 5 CFR 630.1204 - Intermittent leave or reduced leave schedule.

    Science.gov (United States)

    2010-01-01

    ... insurance, health benefits, retirement coverage, and leave accrual). (e) The agency shall determine the... REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1204 Intermittent leave or reduced leave schedule... reduced leave schedule unless the employee and the agency agree to do so. (b) Leave under § 630.1203(a) (3...

  6. Stem photosynthesis in a desert ephemeral, Eriogonum inflatum : Characterization of leaf and stem CO2 fixation and H2O vapor exchange under controlled conditions.

    Science.gov (United States)

    Osmond, C B; Smith, S D; Gui-Ying, B; Sharkey, T D

    1987-07-01

    The gas exchange characteristics of photosynthetic tissues of leaves and stems of Eriogonum inflatum are described. Inflated stems were found to contain extraordinarily high internal CO 2 concentrations (to 14000 μbar), but fixation of this internal CO 2 was 6-10 times slower than fixation of atmospheric CO 2 by these stems. Although the pool of CO 2 is a trivial source of CO 2 for stem photosynthesis, it may result in higher water-use efficiency of stem tissues. Leaf and stem photosynthetic activities were compared by means of CO 2 fixation in CO 2 response curves, light and temperature response curves in IRGA systems, and by means of O 2 exchange at CO 2 saturation in a leaf disc O 2 electrode system. On an area basis leaves contain about twice the chlorophyll and nitrogen as stems, and are capable of up to 4-times the absolute CO 2 and O 2 exchange rates. However, the stem shape is such that lighting of the shaded side leads to a substantial increase in overall stem photosynthesis on a projected area basis, to about half the leaf rate in air. Stem conductance is lower than leaf conductance under most conditions and is less sensitive to high temperature or high VPD. Under most conditions, the ratio C i /C a is lower in stems than in leaves and stems show greater water-use efficiency (higher ratio assimilation/transpiration) as a function of VPD. This potential advantage of stem photosynthesis in a water limited environment may be offset by the higher VPD conditions in the hotter, drier part of the year when stems are active after leaves have senesced. Stem and leaf photosynthesis were similarly affected by decreasing plant water potential.

  7. Stem Cell Basics

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  8. Left or right? Directions to stem cell engraftment : Directions to stem cell engraftment

    NARCIS (Netherlands)

    Belderbos, Mirjam E; Bystrykh, Leonid; de Haan, Gerald

    In this issue of JEM, Wu et al. (https://doi.org/10.1084/jem.20171341) use genetic barcoding of macaque hematopoietic stem cells to demonstrate that, after transplantation, HSCs are very asymmetrically distributed and uncover a thymus-independent pathway for mature T cell production in the bone

  9. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    In his influential essay on markets, An essay on framing and overflowing (1998), Michel Callon writes that `the growing complexity of industrialized societies [is] due in large part to the movements of the technosciences, which are causing connections and interdependencies to proliferate'. This p...... and tantalizing than stem cells, in research, in medicine, or as products.......'. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...

  10. Motivational Maturity and Helping Behavior

    Science.gov (United States)

    Haymes, Michael; Green, Logan

    1977-01-01

    Maturity in conative development (type of motivation included in Maslow's needs hierarchy) was found to be predictive of helping behavior in middle class white male college students. The effects of safety and esteem needs were compared, and the acceptance of responsibility was also investigated. (GDC)

  11. Regulators of growth plate maturation

    NARCIS (Netherlands)

    Emons, Joyce Adriana Mathilde

    2010-01-01

    Estrogen is known to play an important role in longitudinal bone growth and growth plate maturation, but the mechanism by which estrogens exert their effect is not fully understood. In this thesis this role is further explored. Chapter 1 contains a general introduction to longitudinal bone growth

  12. New statement of leave format

    CERN Multimedia

    HR Department

    2009-01-01

    Following the communication of the Standing Concertation Committee published in Weekly Bulletin No. 18-19 of 27 April 2009, the current statement of leave on monthly pay slips has been replaced with the EDH Leave Transactions report that displays the up-to-date situation of individual leave balances at all times. The report is available on EDH. Additionally, the layout of the pay slip has been modernised. The new version of the pay slip will be send out from September 2009 onwards. Finance and Purchasing Department, Personnel Accounting Human Resources Department, Organisation and Procedures General Infrastructure Services Department, Administrative Information Services

  13. Why STEM?

    Science.gov (United States)

    Mitts, Charles R.

    2016-01-01

    The International Technology and Engineering Educators Association (ITEEA) defines STEM as a new transdisciplinary subject in schools that integrates the disciplines of science, technology, engineering, and mathematics into a single course of study. There are three major problems with this definition: There is no consensus in support of the ITEEA…

  14. Tradeoff between Stem Hydraulic Efficiency and Mechanical Strength Affects Leaf–Stem Allometry in 28 Ficus Tree Species

    Directory of Open Access Journals (Sweden)

    Ze-Xin Fan

    2017-09-01

    Full Text Available Leaf–stem allometry is an important spectrum that linked to biomass allocation and life history strategy in plants, although the determinants and evolutionary significance of leaf–stem allometry remain poorly understood. Leaf and stem architectures – including stem area/mass, petiole area/mass, lamina area/mass, leaf number, specific leaf area (LA, and mass-based leafing intensity (LI – were measured on the current-year branches for 28 Ficus species growing in a common garden in SW China. The leaf anatomical traits, stem wood density (WD, and stem anatomical and mechanical properties of these species were also measured. We analyzed leaf–stem allometric relationships and their associations with stem hydraulic ad mechanical properties using species-level data and phylogenetically independent contrasts. We found isometric relationship between leaf lamina area/mass and stem area/mass, suggesting that the biomass allocation to leaf was independent to stem size. However, allometric relationship between LA/mass and petiole mass was found, indicating large leaves invest a higher fractional of biomass in petiole than small ones. LI, i.e., leaf numbers per unit of stem mass, was negatively related with leaf and stem size. Species with larger terminal branches tend to have larger vessels and theoretical hydraulic conductivity, but lower WD and mechanical strength. The size of leaf lamina, petiole, and stem was correlated positively with stem theoretical hydraulic conductivity, but negatively with stem WD and mechanical strength. Our results suggest that leaf–stem allometry in Ficus species was shaped by the trade-off between stem hydraulic efficiency and mechanical stability, supporting a functional interpretation of the relationship between leaf and stem dimensions.

  15. Leaves of Absence. School Law Summary.

    Science.gov (United States)

    National Education Association, Washington, DC. Research Div.

    This report contains State-by-State statutory summaries on three types of leaves of absence relating to teachers -- sick leave, maternity leave, and sabbatical leave. Only State laws that have specific reference to one of these three types of leaves of absence are included. Not included are those statutes granting boards of education the general…

  16. The total antioxidant capacity and fluorescence imaging of selected plant leaves commonly consumed in Brunei Darussalam

    Science.gov (United States)

    Watu, Aswani; Metussin, Nurzaidah; Yasin, Hartini M.; Usman, Anwar

    2018-02-01

    We investigated the total antioxidant capacity and fluorescence imaging of several selected plants, namely Centella asiatica, Aidia borneensis and Anacardium occidentale, which are grown and traditionally consumed in Brunei Darussalam. The total antioxidant capacities of aqueous-methanolic infusions of their leaves were measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and microscopic fluorescence images were measured to identify the fluorescent substances bound in the leaves. We found that the total antioxidant capacity of their infusions is estimated to be 150, 25, 15 folds, respectively, lower compared with that of the standard gallic acid. Accordingly, we demonstrated that the relative antioxidant activity of young and matured leaves agrees with the intensity of red light emission of their fresh leaves upon UV excitation. Thus, this non-invasive spectroscopic method can be potentially utilized to indicate the antioxidants in plant leaves qualitatively.

  17. A study of the factors infuencing the breaking tension of the leaves of ...

    African Journals Online (AJOL)

    The relationship between the breaking tension of the leaves of several indigenous grasses and various possible physical and chemical determinants of this property was examined by means of a multiple linear regression analysis. In this analysis a distinction was drawn between mature and immature herbage and between ...

  18. Neonatal Transplantation Confers Maturation of PSC-Derived Cardiomyocytes Conducive to Modeling Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Gun-Sik Cho

    2017-01-01

    Full Text Available Summary: Pluripotent stem cells (PSCs offer unprecedented opportunities for disease modeling and personalized medicine. However, PSC-derived cells exhibit fetal-like characteristics and remain immature in a dish. This has emerged as a major obstacle for their application for late-onset diseases. We previously showed that there is a neonatal arrest of long-term cultured PSC-derived cardiomyocytes (PSC-CMs. Here, we demonstrate that PSC-CMs mature into adult CMs when transplanted into neonatal hearts. PSC-CMs became similar to adult CMs in morphology, structure, and function within a month of transplantation into rats. The similarity was further supported by single-cell RNA-sequencing analysis. Moreover, this in vivo maturation allowed patient-derived PSC-CMs to reveal the disease phenotype of arrhythmogenic right ventricular cardiomyopathy, which manifests predominantly in adults. This study lays a foundation for understanding human CM maturation and pathogenesis and can be instrumental in PSC-based modeling of adult heart diseases. : Pluripotent stem cell (PSC-derived cells remain fetal like, and this has become a major impediment to modeling adult diseases. Cho et al. find that PSC-derived cardiomyocytes mature into adult cardiomyocytes when transplanted into neonatal rat hearts. This method can serve as a tool to understand maturation and pathogenesis in human cardiomyocytes. Keywords: cardiomyocyte, maturation, iPS, cardiac progenitor, neonatal, disease modeling, cardiomyopathy, ARVC, T-tubule, calcium transient, sarcomere shortening

  19. Chitinase from phaseolus vulgaris leaves

    International Nuclear Information System (INIS)

    Boller, T.; Gehri, A.; Mauch, F.; Vogeli, V.

    1988-01-01

    This paper examines the effect of ethylene on chitinase activity in bean leaves. The authors have purified the enzyme in the course of their work. The purification method is detailed and the colorimetric and radiochemical assays are compared

  20. The Problems of Parental Leave.

    Science.gov (United States)

    Price, Sean

    2017-10-01

    The United States is the only major industrialized country in the world to not require paid parental leave. Numerous studies have shown that allowing parents time with a newborn makes the child and the parents healthier, both physically and mentally. Many physicians, especially those who work in practices with five or fewer doctors, worry about how to pay for parental leave for themselves and their staff.

  1. The happy destiny of frozen haematopoietic stem cells : from immature stem cells to mature applications

    NARCIS (Netherlands)

    de Vries, EGE; Vellenga, E; Kluin-Nelemans, JC; Mulder, NH

    Forty years ago, van Putten described in the European Journal of Cancer (see this issue) quantitative studies on the optimal storage techniques of mouse and monkey bone marrow suspensions. Survival of the animals after irradiation following injection with stored bone marrow cell suspensions was the

  2. Assessment of skeletal maturation using mandibular second molar maturation stages.

    Science.gov (United States)

    Goyal, S; Goyal, S; Gugnani, N

    2014-01-01

    To investigate the relationship between cervical vertebrae maturation and mandibular second molar calcification stages. The study was designed as a retrospective, descriptive and crosssectional research project. Pre-treatment lateral cephalograms and panoramic radiographs of 99 males and 110 females in the age range of 7 to 18 years 7 months were evaluated with Demirjian Index (DI) and cervical vertebrae maturation indicators (CVMI) of Hassel and Farman. A null hypothesis was proposed that there is no relation between CVMI and DI. A highly significant association (Pearson's contingency coefficient 0.713 for males and 0.863 for females) was found between DI and CVMI. In males, the DI stage E corresponded to stage 2 of CVMI (pre-peak of pubertal growth spurt) and DI stages F and G corresponded to stages 3 and 4 of CVMI (peak of pubertal growth spurt). DI stage H was associated with stages 5 and 6 of CVMI (end of pubertal growth spurt). In females, the DI stages C, D corresponded to CVMI stages 1, 2; DI stages E, F with CVMI stages 3, 4; DI stages G, H with CVMI stages 5, 6. Mandibular second molar calcification stages can be used as indicators for assessment of skeletal maturity.

  3. Cervical vertebral maturation as a biologic indicator of skeletal maturity.

    Science.gov (United States)

    Santiago, Rodrigo César; de Miranda Costa, Luiz Felipe; Vitral, Robert Willer Farinazzo; Fraga, Marcelo Reis; Bolognese, Ana Maria; Maia, Lucianne Cople

    2012-11-01

    To identify and review the literature regarding the reliability of cervical vertebrae maturation (CVM) staging to predict the pubertal spurt. The selection criteria included cross-sectional and longitudinal descriptive studies in humans that evaluated qualitatively or quantitatively the accuracy and reproducibility of the CVM method on lateral cephalometric radiographs, as well as the correlation with a standard method established by hand-wrist radiographs. The searches retrieved 343 unique citations. Twenty-three studies met the inclusion criteria. Six articles had moderate to high scores, while 17 of 23 had low scores. Analysis also showed a moderate to high statistically significant correlation between CVM and hand-wrist maturation methods. There was a moderate to high reproducibility of the CVM method, and only one specific study investigated the accuracy of the CVM index in detecting peak pubertal growth. This systematic review has shown that the studies on CVM method for radiographic assessment of skeletal maturation stages suffer from serious methodological failures. Better-designed studies with adequate accuracy, reproducibility, and correlation analysis, including studies with appropriate sensitivity-specificity analysis, should be performed.

  4. DNA methylation and transcriptional trajectories during human development and reprogramming of isogenic pluripotent stem cells

    NARCIS (Netherlands)

    Roost, Matthias S; Slieker, Roderick C; Bialecka, Monika; van Iperen, Liesbeth; Gomes Fernandes, Maria M; He, Nannan; Suchiman, H Eka D; Szuhai, Karoly; Carlotti, Françoise; de Koning, Eelco J P; Mummery, Christine L; Heijmans, Bastiaan T; Chuva de Sousa Lopes, Susana M

    2017-01-01

    Determining cell identity and maturation status of differentiated pluripotent stem cells (PSCs) requires knowledge of the transcriptional and epigenetic trajectory of organs during development. Here, we generate a transcriptional and DNA methylation atlas covering 21 organs during human fetal

  5. Regulation of stem-cell mediated host immunity by the sphingolipid ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Regulation of stem-cell mediated host immunity by the sphingolipid pathway ... in the generation of mature immune cells and the functioning of the surrounding ... methods with human cells and genetically engineered mice to examine how the ...

  6. Quantitative estimates of uptake and internal cycling of 15N-depleted fertilizer in mature walnut trees

    International Nuclear Information System (INIS)

    Weinbaum, S.; Kessel, C. van

    1998-01-01

    In mature fruit trees, internal recycling is an important source of N for the growth of new wood, leaves and fruits. Using 15 N-depleted fertilizer, i.e. 14 N-enriched, N-uptake efficiency and the magnitude of internal N cycling were studied in mature walnut trees. Two kg of 14 N-labelled ammonium sulfate N were applied per tree, and compartmentation of N was followed over a period of 6 years by analyzing catkins, pistillate flowers, leaves and fruits each year for total N content and isotopic composition. Subsequently, two of the six labelled trees were excavated and analyzed for labelled-N content. The data indicate that mature walnut uses most of the N accumulated from soil and fertilizer for storage purposes, to be remobilized for new growth within 2 years, and about half of the total-N pool in a mature tree is present as non-structural compounds, available for recycling. (author)

  7. The DCL gene of tomato is required for chloroplast development and palisade cell morphogenesis in leaves.

    OpenAIRE

    Keddie, J S; Carroll, B; Jones, J D; Gruissem, W

    1996-01-01

    The defective chloroplasts and leaves-mutable (dcl-m) mutation of tomato was identified in a Ds mutagenesis screen. This unstable mutation affects both chloroplast development and palisade cell morphogenesis in leaves. Mutant plants are clonally variegated as a result of somatic excision of Ds and have albino leaves with green sectors. Leaf midribs and stems are light green with sectors of dark green tissue but fruit and petals are wild-type in appearance. Within dark green sectors of dcl-m l...

  8. Displacement of carbon-14 labelled amino acids from leaves

    International Nuclear Information System (INIS)

    Schiller, R.

    1973-01-01

    The displacement of amino acids from nature leaves was investigated. The amino acids (Ala, Asn, Asp, Glu, Gln, Val, Leu, Lys, Ser, Pro) were applied on the leaves in L-form, uniformly labelled with 14 C, and the type and direction of displacement have been observed. Most of the studies have been carried out on bush beans aged 3 to 4 weeks. The experiments were carried out in climatic chambers; in one case, barley plants just reaching maturity were used. In order to find out whether the applied amino acids were also displaced in their original form, freeze-dried plants were extracted and the 14 C activity of the various fraction was determined. The radioactivity of some free amino acids was determined after two-dimensional separation by thin film chromatography. (orig./HK) [de

  9. [Disability leave and sick leave in Spain. 2016 legislative update].

    Science.gov (United States)

    Vicente-Herrero, María Teófila; Terradillos-García, María Jesús; Capdevila-García, Luisa M; Ramírez-Íñiguez de la Torre, María Victoria; Aguilar-Jiménez, Encarna; Aguado-Benedí, María José; López-González, Angel Arturo; Torres-Alberich, José Ignacio

    2018-01-01

    In Spanish, the concepts of discapacidad (disability leave) and incapacidad (sick leave) jointly refer to the impairment of a person due to injuries, diseases or deficiencies that limit their activity in a social, personal or occupational field. However, this common link does not imply that both concepts are the same. Statistical data from INE (Instituto Nacional de Estadística: Statistic National Institute) show that Spain had in 2015 3.85 million persons with a disability (59.8% were women). Statistical data from 2015 from INSS (Instituto Nacional de Seguridad Social: Social Security National Institute) show high levels in the number of processes and in workers affected by temporary sick leave, with social costs to the social security system. Both concepts have been updated: about disability leave, Law 39/2006 adjusted terminology by avoiding the use of concepts with discriminating or pejorative connotation. Regarding sick leave, the Ley General de Seguridad Social (General Social Security Law)has been amended and came into effect in January, 2016. It is necessary to know and distinguish these aspects for a better administrative management, and a more oriented information to the affected patient.

  10. Monocot leaves are eaten less than dicot leaves in tropical lowland rain forests: correlations with toughness and leaf presentation

    DEFF Research Database (Denmark)

    Grubb, P.J.; Jackson, R.V.; Barberis, I.M.

    2008-01-01

    . It was hypothesized that (a) losses of leaf area to herbivorous invertebrates are generally greatest during leaf expansion and smaller for monocots than for dicots, and (b) where losses after expansion are appreciable any difference between monocots and dicots then is smaller than that found during expansion. Methods......: At six sites on four continents, estimates were made of lamina area loss from the four most recently mature leaves of focal monocots and of the nearest dicot shoot. Measurements of leaf mass per unit area, and the concentrations of water and nitrogen were made for many of the species. In Panama...... of leaf mass per unit area, or concentrations of water or nitrogen. At only one site was the increase in loss from first to fourth mature leaf significant (also large and the same in monocots and dicots), but the losses sustained during expansion were much smaller in the monocots. In the leaf-cutter ant...

  11. Maturation of the adolescent brain

    Directory of Open Access Journals (Sweden)

    Arain M

    2013-04-01

    Full Text Available Mariam Arain, Maliha Haque, Lina Johal, Puja Mathur, Wynand Nel, Afsha Rais, Ranbir Sandhu, Sushil Sharma Saint James School of Medicine, Kralendijk, Bonaire, The Netherlands Abstract: Adolescence is the developmental epoch during which children become adults – intellectually, physically, hormonally, and socially. Adolescence is a tumultuous time, full of changes and transformations. The pubertal transition to adulthood involves both gonadal and behavioral maturation. Magnetic resonance imaging studies have discovered that myelinogenesis, required for proper insulation and efficient neurocybernetics, continues from childhood and the brain's region-specific neurocircuitry remains structurally and functionally vulnerable to impulsive sex, food, and sleep habits. The maturation of the adolescent brain is also influenced by heredity, environment, and sex hormones (estrogen, progesterone, and testosterone, which play a crucial role in myelination. Furthermore, glutamatergic neurotransmission predominates, whereas gamma-aminobutyric acid neurotransmission remains under construction, and this might be responsible for immature and impulsive behavior and neurobehavioral excitement during adolescent life. The adolescent population is highly vulnerable to driving under the influence of alcohol and social maladjustments due to an immature limbic system and prefrontal cortex. Synaptic plasticity and the release of neurotransmitters may also be influenced by environmental neurotoxins and drugs of abuse including cigarettes, caffeine, and alcohol during adolescence. Adolescents may become involved with offensive crimes, irresponsible behavior, unprotected sex, juvenile courts, or even prison. According to a report by the Centers for Disease Control and Prevention, the major cause of death among the teenage population is due to injury and violence related to sex and substance abuse. Prenatal neglect, cigarette smoking, and alcohol consumption may also

  12. Estimating chlorophyll content from Eucalyptus dunnii leaves by reflectance values

    Directory of Open Access Journals (Sweden)

    João Alexandre Lopes Dranski

    2016-06-01

    Full Text Available This study aimed to estimate photosynthetic pigments contents from leaves of Eucalyptus dunni Maiden based on values of reflectance spectra of red, green and blue colors obtained with a digital color analyzer. We collected fifty leaves from the lower third of the crown of twenty trees including young as well as mature leaves. From each leaf an area of 14 cm2 of the leaf blade was cut in which we measured reflectance values on the red, green and blue spectra with a portable digital colorimeter, obtained relative index of chlorophyll with a SPAD – 502 and determined the content of the chlorophyll a, b, and a + b by classic method of solvent extraction. We submitted the data to multiple linear regression and nonlinear analysis at 5% of error probability. It was evaluated the occurrence of multicollinearity. The negative exponential model resulted in good fit when data from red spectrum was used for chlorophyll a, green spectrum for chlorophyll b and a + b, making possible correlation coefficients between the estimated values and the extracted above 0.85. Except for the chlorophyll a content, the accuracy in estimates of photosynthetic pigments were higher than estimated by the chlorophyll meter, even with linearity between methods. Therefore, it is possible to estimate photosynthetic pigments on E. dunni leaves through values of red and green wavelengths from a digital color analyser.

  13. Therapeutic Application of Pluripotent Stem Cells: Challenges and Risks

    Directory of Open Access Journals (Sweden)

    Ulrich Martin

    2017-12-01

    Full Text Available Stem-cell-based therapies are considered to be promising and innovative but complex approaches. Induced pluripotent stem cells (iPSCs combine the advantages of adult stem cells with the hitherto unique characteristics of embryonic stem cells (ESCs. Major progress has already been achieved with regard to reprogramming technology, but also regarding targeted genome editing and scalable expansion and differentiation of iPSCs and ESCs, in some cases yielding highly enriched preparations of well-defined cell lineages at clinically required dimensions. It is noteworthy, however, that for many applications critical requirements such as the targeted specification into distinct cellular subpopulations and a proper cell maturation remain to be achieved. Moreover, current hurdles such as low survival rates and insufficient functional integration of cellular transplants remain to be overcome. Nevertheless, PSC technologies obviously have come of age and matured to a stage where various clinical applications of PSC-based cellular therapies have been initiated and are conducted.

  14. RADIO NOISE ADVANCES SEXUAL MATURITY

    African Journals Online (AJOL)

    ansistf-lewis

    Mean age at first egg for the radio birds (143 d) was 13 d significantly earlier than controls, but body weight at ... the first 8 h of a 12-h photoperiod with radio noise, to leave only 4 h of light (4L:20D), supported rates of lay ... Age (AFE) and body weight at, and weight of, first egg were recorded for individual birds, and, after a.

  15. Variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species.

    Science.gov (United States)

    Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

    2008-12-01

    Forest transpiration estimates are frequently based on xylem sap flux measurements in the outer sections of the hydro-active stem sapwood. We used Granier's constant-heating technique with heating probes at various xylem depths to analyze radial patterns of sap flux density in the sapwood of seven broad-leaved tree species differing in wood density and xylem structure. Study aims were to (1) compare radial sap flux density profiles between diffuse- and ring-porous trees and (2) analyze the relationship between hydro-active sapwood area and stem diameter. In all investigated species except the diffuse-porous beech (Fagus sylvatica L.) and ring-porous ash (Fraxinus excelsior L.), sap flux density peaked at a depth of 1 to 4 cm beneath the cambium, revealing a hump-shaped curve with species-specific slopes. Beech and ash reached maximum sap flux densities immediately beneath the cambium in the youngest annual growth rings. Experiments with dyes showed that the hydro-active sapwood occupied 70 to 90% of the stem cross-sectional area in mature trees of diffuse-porous species, whereas it occupied only about 21% in ring-porous ash. Dendrochronological analyses indicated that vessels in the older sapwood may remain functional for 100 years or more in diffuse-porous species and for up to 27 years in ring-porous ash. We conclude that radial sap flux density patterns are largely dependent on tree species, which may introduce serious bias in sap-flux-derived forest transpiration estimates, if non-specific sap flux profiles are assumed.

  16. STUDY OF ORGANIC ACIDS IN ALMOND LEAVES

    Directory of Open Access Journals (Sweden)

    Lenchyk L.V.

    2015-05-01

    Full Text Available Introduction. Almond (Amygdalus communis is a stone fruit, from the Rosaceae family, closest to the peach. It is spread throughout the entire Mediterranean region and afterwards to the Southwestern USA, Northern Africa, Turkey, Iran, Australia and South Africa. It is sensitive to wet conditions, and therefore is not grown in wet climates. Iran is located in the semi-arid region of the world. Because of its special tolerance to water stress, almond is one of the main agricultural products in rainfed condition in Iran. Almond leaves have been investigated for their phenolic content and antioxidant activity. It was found that total antioxidant activity and phenolic compounds exhibited variations according to season, plant organ (leaf and stem and variety. Analysis of previous research on almonds focused on investigating compounds mostly in seeds and phenolic compounds in leaves, but organic acids in leaves have not been studied. Aim of this study was investigation of organic acids in leaves of almond variety which is distributed in Razavi Khorasan province of Iran. Materials and Methods. In August 2012 almond leaves were collected in Iran, dried and grinded. The study of qualitative composition and quantitative determination of carboxylic acids in almond leaves was carried out by gas chromatography with mass spectrometric detection. For determination organic acids content, to 50 mg of dried plant material in 2 ml vial internal standard (50 μg of tridecane in hexane was added and filled up with 1.0 ml of methylating agent (14 % BCl3 in methanol, Supelco 3-3033. The mixture was kept in a sealed vial during 8 hours at 65 °C. At this time fatty oil was fully extracted, and hydrolyzed into its constituent fatty acids and their methylation was done. At the same time free organic and phenolcarbonic acids were methylated too. The reaction mixture was poured from the plant material sediment and was diluted with 1 ml of distilled water. To extract methyl

  17. Why People Leave Their Jobs?

    Directory of Open Access Journals (Sweden)

    Luis R. Domínguez A.

    2014-12-01

    Full Text Available This article aims to show the results of the review of literature of relevant studies of the causal elements of intention to leave in the last five years (2009-2013. The method used to evaluate the literature was based on the seven steps for research synthesis: problem formulation, literature search, obtaining information from studies, quality assessment studies, analysis and integration of results, interpretation of evidence and presentation of results. 48 studies from 15 different countries with a sample of 35804 employees of different companies were evaluated. The findings suggest the existence of 89 different variables influencing the intention to leave of employees in an organization. The results of this study will allow researchers to better understand the variables that can be studied to verify the impact of variables such as causal elements, but also see those that have a mediating effect between them for predicting intention to leave as an element of employee turnover. This study makes three important contributions to literature of turnover. First, in this study all the parameters associated with the intention to leave were checked. Second, this study categorizes and displays in proportion relevant interests to the scientific community whom studying employee turnover across the intention to leave. And thirdly provides clues organizations to improve some of its structural and contextual features to control turnover.

  18. Efficient Generation of Functional Hepatocytes From Human Embryonic Stem Cells and Induced Pluripotent Stem Cells by HNF4α Transduction

    OpenAIRE

    Takayama, Kazuo; Inamura, Mitsuru; Kawabata, Kenji; Katayama, Kazufumi; Higuchi, Maiko; Tashiro, Katsuhisa; Nonaka, Aki; Sakurai, Fuminori; Hayakawa, Takao; Kusuda Furue, Miho; Mizuguchi, Hiroyuki

    2012-01-01

    Hepatocyte-like cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are expected to be a useful source of cells drug discovery. Although we recently reported that hepatic commitment is promoted by transduction of SOX17 and HEX into human ESC- and iPSC-derived cells, these hepatocyte-like cells were not sufficiently mature for drug screening. To promote hepatic maturation, we utilized transduction of the hepatocyte nuclear factor 4α (HNF4α) gene, which is kn...

  19. Stem cell biobanks.

    Science.gov (United States)

    Bardelli, Silvana

    2010-04-01

    Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

  20. Parental leave: the impact of recent legislation on parents' leave taking.

    Science.gov (United States)

    Han, Wen-Jui; Waldfogel, Jane

    2003-02-01

    We use data from the Survey of Income and Program Participation to examine the impact of leave entitlements on unpaid leave usage by men and women after the birth of a child from 1991 to 1999. The results indicate that legislation providing the right to unpaid leave has not affected men's leave usage. The results for women are mixed: in some specifications, leave entitlements are associated with increased leave taking or longer leaves, but the results depend on how we define leave coverage. Our results point to the limited impact of unpaid leave policies and the potential importance of paid-leave policies.

  1. Defined Engineered Human Myocardium with Advanced Maturation for Applications in Heart Failure Modelling and Repair

    Science.gov (United States)

    Tiburcy, Malte; Hudson, James E.; Balfanz, Paul; Schlick, Susanne; Meyer, Tim; Liao, Mei-Ling Chang; Levent, Elif; Raad, Farah; Zeidler, Sebastian; Wingender, Edgar; Riegler, Johannes; Wang, Mouer; Gold, Joseph D.; Kehat, Izhak; Wettwer, Erich; Ravens, Ursula; Dierickx, Pieterjan; van Laake, Linda W.; Goumans, Marie Jose; Khadjeh, Sara; Toischer, Karl; Hasenfuss, Gerd; Couture, Larry A.; Unger, Andreas; Linke, Wolfgang A.; Araki, Toshiyuki; Neel, Benjamin; Keller, Gordon; Gepstein, Lior; Wu, Joseph C.; Zimmermann, Wolfram-Hubertus

    2017-01-01

    Background Advancing structural and functional maturation of stem cell-derived cardiomyocytes remains a key challenge for applications in disease modelling, drug screening, and heart repair. Here, we sought to advance cardiomyocyte maturation in engineered human myocardium (EHM) towards an adult phenotype under defined conditions. Methods We systematically investigated cell composition, matrix and media conditions to generate EHM from embryonic and induced pluripotent stem cell-derived cardiomyocytes and fibroblasts with organotypic functionality under serum-free conditions. We employed morphological, functional, and transcriptome analyses to benchmark maturation of EHM. Results EHM demonstrated important structural and functional properties of postnatal myocardium, including: (1) rod-shaped cardiomyocytes with M-bands assembled as a functional syncytium; (2) systolic twitch forces at a similar level as observed in bona fide postnatal myocardium; (3) a positive force-frequency-response; (4) inotropic responses to β-adrenergic stimulation mediated via canonical β1- and β2-adrenoceptor signaling pathways; and (5) evidence for advanced molecular maturation by transcriptome profiling. EHM responded to chronic catecholamine toxicity with contractile dysfunction, cardiomyocyte hypertrophy, cardiomyocyte death, and NT-proBNP release; all are classical hallmarks of heart failure. Additionally, we demonstrate scalability of EHM according to anticipated clinical demands for cardiac repair. Conclusions We provide proof-of-concept for a universally applicable technology for the engineering of macro-scale human myocardium for disease modelling and heart repair from embryonic and induced pluripotent stem cell-derived cardiomyocytes under defined, serum-free conditions. PMID:28167635

  2. Defined Engineered Human Myocardium With Advanced Maturation for Applications in Heart Failure Modeling and Repair.

    Science.gov (United States)

    Tiburcy, Malte; Hudson, James E; Balfanz, Paul; Schlick, Susanne; Meyer, Tim; Chang Liao, Mei-Ling; Levent, Elif; Raad, Farah; Zeidler, Sebastian; Wingender, Edgar; Riegler, Johannes; Wang, Mouer; Gold, Joseph D; Kehat, Izhak; Wettwer, Erich; Ravens, Ursula; Dierickx, Pieterjan; van Laake, Linda W; Goumans, Marie Jose; Khadjeh, Sara; Toischer, Karl; Hasenfuss, Gerd; Couture, Larry A; Unger, Andreas; Linke, Wolfgang A; Araki, Toshiyuki; Neel, Benjamin; Keller, Gordon; Gepstein, Lior; Wu, Joseph C; Zimmermann, Wolfram-Hubertus

    2017-05-09

    Advancing structural and functional maturation of stem cell-derived cardiomyocytes remains a key challenge for applications in disease modeling, drug screening, and heart repair. Here, we sought to advance cardiomyocyte maturation in engineered human myocardium (EHM) toward an adult phenotype under defined conditions. We systematically investigated cell composition, matrix, and media conditions to generate EHM from embryonic and induced pluripotent stem cell-derived cardiomyocytes and fibroblasts with organotypic functionality under serum-free conditions. We used morphological, functional, and transcriptome analyses to benchmark maturation of EHM. EHM demonstrated important structural and functional properties of postnatal myocardium, including: (1) rod-shaped cardiomyocytes with M bands assembled as a functional syncytium; (2) systolic twitch forces at a similar level as observed in bona fide postnatal myocardium; (3) a positive force-frequency response; (4) inotropic responses to β-adrenergic stimulation mediated via canonical β 1 - and β 2 -adrenoceptor signaling pathways; and (5) evidence for advanced molecular maturation by transcriptome profiling. EHM responded to chronic catecholamine toxicity with contractile dysfunction, cardiomyocyte hypertrophy, cardiomyocyte death, and N-terminal pro B-type natriuretic peptide release; all are classical hallmarks of heart failure. In addition, we demonstrate the scalability of EHM according to anticipated clinical demands for cardiac repair. We provide proof-of-concept for a universally applicable technology for the engineering of macroscale human myocardium for disease modeling and heart repair from embryonic and induced pluripotent stem cell-derived cardiomyocytes under defined, serum-free conditions. © 2017 American Heart Association, Inc.

  3. 7 CFR 51.1904 - Maturity classification.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Maturity classification. 51.1904 Section 51.1904... STANDARDS) United States Consumer Standards for Fresh Tomatoes Size and Maturity Classification § 51.1904 Maturity classification. Tomatoes which are characteristically red when ripe, but are not overripe or soft...

  4. Structural and ultrastructural study of Capsicum annuum leaves after treatment with Uncaria tomentosa bark extracts

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska

    2011-01-01

    Full Text Available The influence of an Uncaria tomentosa extract on the development of Capsicum plants grown in green-house conditions was examined. The effect of the treatment was investigated with microscopic techniques (light and electron microscope in leaves from three levels of control plants and plants after treatment with the extract added to the soil in doses of 0.4 and 16 mg/ml (200 ml per pot/plant. In control leaves, changes typical of the subsequent phases of normal development were observed: nuclear chromatin became slightly condensed, plastoglobuli of chloroplasts increased in number and size, intragranal thylakoids were somewhat dilatated. In addition to such commonly occurring changes, some symptoms typical of pepper were observed in the ontogenesis of the examined plant: an increased number of spherical electron-dense deposits in vacuoles, an increased number of peroxisomes, the occurrence of numerous paracrystalline structures in chloroplasts of mature leaves, and, starting in mature leaves, expulsion of plastoglobuli from chloroplasts. After the treatment, most of those changes, leading to ageing, occurred much earlier and were more distinct. Chloroplasts, already in the youngest examined leaves, showed dilatation of intergranal thylakoids, which intensified with aging of the leaves and degradation of grana in the oldest leaves. Starch grains decreased in size and number and plastoglobuli became large. Vesiculation of ground cytoplasm in all leaves was stronger than in the control. No paracrystalline structures in chloroplasts or expulsion of plastoglobuli were observed. Another unusual phenomenon was the disappearance of spherical electron-dense deposits in the central vacuoles of cells. Those observations suggested that U. tomentosa extract enhanced the natural ontogenesis of Capsicum annuum leaves, by accelerating and enhancing the typical characteristics of ageing, and, additionally, it changed the structure and physiology of cells.

  5. Novel expression patterns of carotenoid pathway-related gene in citrus leaves and maturing fruits

    Science.gov (United States)

    Carotenoids are abundant in citrus fruits and vary among cultivars and species. In the present study, HPLC and real-time PCR were used to investigate the expression patterns of 23 carotenoid biosynthesis gene family members and their possible relation with carotenoid accumulation in flavedo, juice s...

  6. Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin.

    Science.gov (United States)

    Dorn, Isabel; Klich, Katharina; Arauzo-Bravo, Marcos J; Radstaak, Martina; Santourlidis, Simeon; Ghanjati, Foued; Radke, Teja F; Psathaki, Olympia E; Hargus, Gunnar; Kramer, Jan; Einhaus, Martin; Kim, Jeong Beom; Kögler, Gesine; Wernet, Peter; Schöler, Hans R; Schlenke, Peter; Zaehres, Holm

    2015-01-01

    Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34(+) hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34(+) hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells. Although genome-wide DNA methylation profiling at all promoter regions demonstrates that the epigenetic memory of induced pluripotent stem cells is influenced by the somatic cell type of origin of the stem cells, we found a similar hematopoietic induction potential and erythroid differentiation pattern of induced pluripotent stem cells of different somatic cell origin. All human induced pluripotent stem cell lines showed terminal maturation into normoblasts and enucleated reticulocytes, producing predominantly fetal hemoglobin. Differences were only observed in the growth rate of erythroid cells, which was slightly higher in the induced pluripotent stem cells derived from CD34(+) hematopoietic stem cells. More detailed methylation analysis of the hematopoietic and erythroid promoters identified similar CpG methylation levels in the induced pluripotent stem cell lines derived from CD34(+) cells and those derived from neural stem cells, which confirms their comparable erythroid differentiation potential. Copyright© Ferrata Storti Foundation.

  7. An Evaluation of Paid Leave

    DEFF Research Database (Denmark)

    Albæk, Karsten

    This paper analyzes a labor market program which enables workers to leave employment temporarily with a compensation financed by the taxpayers. The main aim of the program was to increase the chances of the unemployed finding a job. However, the empirical analysis reveals a clear negative...... relationship between the unemployment rate and transition rates from employment into the paid leave scheme. Program participation is low, precisely in those labor market states, where the scheme has a potential to perform as a remedy by increasing the transition rate from unemployment to employment. Several...

  8. Evolutionary insights into postembryonic development of adult intestinal stem cells

    Directory of Open Access Journals (Sweden)

    Ishizuya-Oka Atsuko

    2011-11-01

    Full Text Available Abstract In the adult vertebrate intestine, multi-potent stem cells continuously generate all of the epithelial cells throughout the adulthood. While it has long been known that the frog intestine is formed via the development of adult intestinal stem cells during thyroid hormone (TH-dependent metamorphosis, the basic structure of the adult intestine is formed by birth in mammals and it is unclear if the subsequent maturation of the intestine involves any changes in the intestinal stem cells. Two recent papers showing that B lymphocyte-induced maturation protein 1 (Blimp1 regulates postnatal epithelial stem cell reprogramming during mouse intestinal maturation support the model that adult intestinal stem cells are developed during postembryonic development in mammals, in a TH-dependent process similar to intestinal remodeling during amphibian metamorphosis. Since the formation of the adult intestine in both mammals and amphibians is closely associated with the adaptation from aquatic to terrestrial life during the peak of endogenous TH levels, the molecular mechanisms by which the adult stem cells are developed are likely evolutionally conserved.

  9. Academic Achievement of High School Students in Relation to Their Anxiety, Emotional Maturity and Social Maturity

    Science.gov (United States)

    Puar, Surjit Singh

    2013-01-01

    The present study has been designed to investigate the non-cognitive variables like anxiety, emotional maturity and social maturity and their relationship with academic achievement and also to see the locale-wise differences on the basis of their anxiety, emotional maturity and social maturity. The study was conducted over a sample of 400 (200…

  10. Maturity models in supply chain sustainability

    DEFF Research Database (Denmark)

    Correia, Elisabete; Carvalho, Helena; Azevedo, Susana G.

    2017-01-01

    A systematic literature review of supply chain maturity models with sustainability concerns is presented. The objective is to give insights into methodological issues related to maturity models, namely the research objectives; the research methods used to develop, validate and test them; the scope...... of maturity levels. The comprehensive review, analysis, and synthesis of the maturity model literature represent an important contribution to the organization of this research area, making possible to clarify some confusion that exists about concepts, approaches and components of maturity models...

  11. Biomechanical differences in the stem straightening process among Pinus pinaster provenances. A new approach for early selection of stem straightness.

    Science.gov (United States)

    Sierra-de-Grado, Rosario; Pando, Valentín; Martínez-Zurimendi, Pablo; Peñalvo, Alejandro; Báscones, Esther; Moulia, Bruno

    2008-06-01

    Stem straightness is an important selection trait in Pinus pinaster Ait. breeding programs. Despite the stability of stem straightness rankings in provenance trials, the efficiency of breeding programs based on a quantitative index of stem straightness remains low. An alternative approach is to analyze biomechanical processes that underlie stem form. The rationale for this selection method is that genetic differences in the biomechanical processes that maintain stem straightness in young plants will continue to control stem form throughout the life of the tree. We analyzed the components contributing most to genetic differences among provenances in stem straightening processes by kinetic analysis and with a biomechanical model defining the interactions between the variables involved (Fournier's model). This framework was tested on three P. pinaster provenances differing in adult stem straightness and growth. One-year-old plants were tilted at 45 degrees, and individual stem positions and sizes were recorded weekly for 5 months. We measured the radial extension of reaction wood and the anatomical features of wood cells in serial stem cross sections. The integral effect of reaction wood on stem leaning was computed with Fournier's model. Responses driven by both primary and secondary growth were involved in the stem straightening process, but secondary-growth-driven responses accounted for most differences among provenances. Plants from the straight-stemmed provenance showed a greater capacity for stem straightening than plants from the sinuous provenances mainly because of (1) more efficient reaction wood (higher maturation strains) and (2) more pronounced secondary-growth-driven autotropic decurving. These two process-based traits are thus good candidates for early selection of stem straightness, but additional tests on a greater number of genotypes over a longer period are required.

  12. Mismatch repair deficient hematopoietic stem cells are preleukemic stem cells.

    Directory of Open Access Journals (Sweden)

    Yulan Qing

    Full Text Available Whereas transformation events in hematopoietic malignancies may occur at different developmental stages, the initial mutation originates in hematopoietic stem cells (HSCs, creating a preleukemic stem cell (PLSC. Subsequent mutations at either stem cell or progenitor cell levels transform the PLSC into lymphoma/leukemia initiating cells (LIC. Thymic lymphomas have been thought to develop from developing thymocytes. T cell progenitors are generated from HSCs in the bone marrow (BM, but maturation and proliferation of T cells as well as T-lymphomagenesis depends on both regulatory mechanisms and microenvironment within the thymus. We studied PLSC linked to thymic lymphomas. In this study, we use MSH2-/- mice as a model to investigate the existence of PLSC and the evolution of PLSC to LIC. Following BM transplantation, we found that MSH2-/- BM cells from young mice are able to fully reconstitute multiple hematopoietic lineages of lethally irradiated wild-type recipients. However, all recipients developed thymic lymphomas within three and four months post transplantation. Transplantation of different fractions of BM cells or thymocytes from young health MSH2-/- mice showed that an HSC enriched fraction always reconstituted hematopoiesis followed by lymphoma development. In addition, lymphomas did not occur in thymectomized recipients of MSH2-/- BM. These results suggest that HSCs with DNA repair defects such as MSH2-/- are PLSCs because they retain hematopoietic function, but also carry an obligate lymphomagenic potential within their T-cell progeny that is dependent on the thymic microenvironment.

  13. Maturity Models Development in IS Research

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi; Andersen, Kim Normann

    2015-01-01

    Maturity models are widespread in IS research and in particular, IT practitioner communities. However, theoretically sound, methodologically rigorous and empirically validated maturity models are quite rare. This literature review paper focuses on the challenges faced during the development...... literature reveals that researchers have primarily focused on developing new maturity models pertaining to domain-specific problems and/or new enterprise technologies. We find rampant re-use of the design structure of widely adopted models such as Nolan’s Stage of Growth Model, Crosby’s Grid, and Capability...... Maturity Model (CMM). Only recently have there been some research efforts to standardize maturity model development. We also identify three dominant views of maturity models and provide guidelines for various approaches of constructing maturity models with a standard vocabulary. We finally propose using...

  14. Functional Differences in Engineered Myocardium from Embryonic Stem Cell-Derived versus Neonatal Cardiomyocytes

    NARCIS (Netherlands)

    Feinberg, Adam W.; Ripplinger, Crystal M.; van der Meer, Peter; Sheehy, Sean P.; Domian, Ibrahim; Chien, Kenneth R.; Parker, Kevin Kit

    2013-01-01

    Stem cell-derived cardiomyocytes represent unique tools for cell-and tissue-based regenerative therapies, drug discovery and safety, and studies of fundamental heart-failure mechanisms. However, the degree to which stem cell-derived cardiomyocytes compare to mature cardiomyocytes is often debated.

  15. In vivo evaluation of human dental pulp stem cells differentiated towards multiple lineages.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Kuppevelt, A.H.M.S.M. van; Daamen, W.F.; Damme, P.A. van; Bian, Z.; Jansen, J.A.

    2008-01-01

    An increasing number of investigations supports that adult stem cells have the potential to differentiate into matured cell types beyond their origin, a property defined as plasticity. Previously, the plasticity of stem cells derived from dental pulp (DPSC) has been confirmed by culturing cells in

  16. Production Methods for a Mesenchymal Stem Cell Therapeutic as a Medical Defense Countermeasure

    Science.gov (United States)

    2012-02-01

    mesenchymal stem cell (MSC) efficacy in a variety of injury models demonstrate the unique qualities of this reparative cell population to adapt to the...therapeutic product. Characterization of stem cell properties of culture-expanded MSCs is shown by in vitro differentiation to form mature cell types. The

  17. Activities of fructan- and sucrose-metabolizing enzymes in wheat stems subjected to water stress during grain filling.

    Science.gov (United States)

    Yang, Jianchang; Zhang, Jianhua; Wang, Zhiqing; Zhu, Qingsen; Liu, Lijun

    2004-12-01

    This study investigated if a controlled water deficit during grain filling of wheat (Triticum aestivum L.) could accelerate grain filling by facilitating the remobilization of carbon reserves in the stem through regulating the enzymes involved in fructan and sucrose metabolism. Two high lodging-resistant wheat cultivars were grown in pots and treated with either a normal (NN) or high amount of nitrogen (HN) at heading time. Plants were either well-watered (WW) or water-stressed (WS) from 9 days post anthesis until maturity. Leaf water potentials markedly decreased at midday as a result of water stress but completely recovered by early morning. Photosynthetic rate and zeatin + zeatin riboside concentrations in the flag leaves declined faster in WS plants than in WW plants, and they decreased more slowly with HN than with NN when soil water potential was the same, indicating that the water deficit enhanced, whereas HN delayed, senescence. Water stress, both at NN and HN, facilitated the reduction in concentration of total nonstructural carbohydrates (NSC) and fructans in the stems but increased the sucrose level there, promoted the re-allocation of pre-fixed (14)C from the stems to grains, shortened the grain-filling period, and accelerated the grain-filling rate. Grain weight and grain yield were increased under the controlled water deficit when HN was applied. Fructan exohydrolase (FEH; EC 3.2.1.80) and sucrose phosphate synthase (SPS; EC 2.4.1.14) activities were substantially enhanced by water stress and positively correlated with the total NSC and fructan remobilization from the stems. Acid invertase (EC 3.2.1.26) activity was also enhanced by the water stress and associated with the change in fructan concentration, but not correlated with the total NSC remobilization and (14)C increase in the grains. Sucrose:sucrose fructosyltransferase (EC 2.4.1.99) activity was inhibited by the water stress and negatively correlated with the remobilization of carbon reserves

  18. Watch out for the leaves!

    CERN Multimedia

    HSE Unit

    2013-01-01

    Now that autumn is here, dead leaves falling from the trees form a colourful carpet that is pleasing to the eye. However, the reality is less pleasant for pedestrians, since these leaves increase the risk of slipping and falling, especially when the ground is wet.   These conditions are also hazardous for two- and four-wheeled vehicles, whose grip on the ground can be severely reduced, thereby increasing the risk of them skidding out of control. Cyclists are among the most vulnerable road users when faced with these hazards. It is therefore essential to be alert to the dangers, which can be lessened by taking a few simple precautions such as moderating your speed and wearing suitable shoes. We also invite you to notify the Service Desk if you notice a road or pavement where there is a high concentration of dead leaves. The CERN Roads and Drainage Service will then ensure that the leaves are cleared in order to reduce the risk of accidents in the area.

  19. Nutrient resorption from seagrass leaves

    NARCIS (Netherlands)

    Stapel, J.; Hemminga, M.A.

    1997-01-01

    The resorption of nutrients (C, N and P) from senescent leaves of six seagrass species from nine different locations in tropical (Indonesia and Kenya), Mediterranean (Spain) and temperate (The Netherlands) regions has been investigated. Resorption was quantitatively assessed by calculating the

  20. Activation of dormant ovarian follicles to generate mature eggs.

    Science.gov (United States)

    Li, Jing; Kawamura, Kazuhiro; Cheng, Yuan; Liu, Shuang; Klein, Cynthia; Liu, Shu; Duan, En-Kui; Hsueh, Aaron J W

    2010-06-01

    Although multiple follicles are present in mammalian ovaries, most of them remain dormant for years or decades. During reproductive life, some follicles are activated for development. Genetically modified mouse models with oocyte-specific deletion of genes in the PTEN-PI3K-Akt-Foxo3 pathway exhibited premature activation of all dormant follicles. Using an inhibitor of the Phosphatase with TENsin homology deleted in chromosome 10 (PTEN) phosphatase and a PI3K activating peptide, we found that short-term treatment of neonatal mouse ovaries increased nuclear exclusion of Foxo3 in primordial oocytes. After transplantation under kidney capsules of ovariectomized hosts, treated follicles developed to the preovulatory stage with mature eggs displaying normal epigenetic changes of imprinted genes. After in vitro fertilization and embryo transfer, healthy progeny with proven fertility were delivered. Human ovarian cortical fragments from cancer patients were also treated with the PTEN inhibitor. After xeno-transplantation to immune-deficient mice for 6 months, primordial follicles developed to the preovulatory stage with oocytes capable of undergoing nuclear maturation. Major differences between male and female mammals are unlimited number of sperm and paucity of mature oocytes. Thus, short-term in vitro activation of dormant ovarian follicles after stimulation of the PI3K-Akt pathway allows the generation of a large supply of mature female germ cells for future treatment of infertile women with a diminishing ovarian reserve and for cancer patients with cryo-preserved ovaries. Generation of a large number of human oocytes also facilitates future derivation of embryonic stem cells for regenerative medicine.

  1. From stem cell to embryo without centrioles.

    Science.gov (United States)

    Stevens, Naomi R; Raposo, Alexandre A S F; Basto, Renata; St Johnston, Daniel; Raff, Jordan W

    2007-09-04

    Centrosome asymmetry plays a key role in ensuring the asymmetric division of Drosophila neural stem cells (neuroblasts [NBs]) and male germline stem cells (GSCs) [1-3]. In both cases, one centrosome is anchored close to a specific cortical region during interphase, thus defining the orientation of the spindle during the ensuing mitosis. To test whether asymmetric centrosome behavior is a general feature of stem cells, we have studied female GSCs, which divide asymmetrically, producing another GSC and a cystoblast. The cystoblast then divides and matures into an oocyte, a process in which centrosomes exhibit a series of complex behaviors proposed to play a crucial role in oogenesis [4-6]. We show that the interphase centrosome does not define spindle orientation in female GSCs and that DSas-4 mutant GSCs [7], lacking centrioles and centrosomes, invariably divide asymmetrically to produce cystoblasts that proceed normally through oogenesis-remarkably, oocyte specification, microtubule organization, and mRNA localization are all unperturbed. Mature oocytes can be fertilized, but embryos that cannot support centriole replication arrest very early in development. Thus, centrosomes are dispensable for oogenesis but essential for early embryogenesis. These results reveal that asymmetric centrosome behavior is not an essential feature of stem cell divisions.

  2. Proteomic cornerstones of hematopoietic stem cell differentiation

    DEFF Research Database (Denmark)

    Klimmeck, Daniel; Hansson, Jenny; Raffel, Simon

    2012-01-01

    Regenerative tissues such as the skin epidermis, the intestinal mucosa or the hematopoietic system are organized in a hierarchical manner with stem cells building the top of this hierarchy. Somatic stem cells harbor the highest self-renewal activity and generate a series of multipotent progenitors...... which differentiate into lineage committed progenitors and subsequently mature cells. In this report, we applied an in-depth quantitative proteomic approach to analyze and compare the full proteomes of ex vivo isolated and FACS-sorted populations highly enriched for either multipotent hematopoietic stem....../progenitor cells (HSPCs, Lin(neg)Sca-1(+)c-Kit(+)) or myeloid committed precursors (Lin(neg)Sca-1(-)c-Kit(+)). By employing stable isotope dimethyl labeling and high-resolution mass spectrometry, more than 5,000 proteins were quantified. From biological triplicate experiments subjected to rigorous statistical...

  3. 29 CFR 825.202 - Intermittent leave or reduced leave schedule.

    Science.gov (United States)

    2010-07-01

    ... leave schedule is a leave schedule that reduces an employee's usual number of working hours per workweek, or hours per workday. A reduced leave schedule is a change in the employee's schedule for a period of... 29 Labor 3 2010-07-01 2010-07-01 false Intermittent leave or reduced leave schedule. 825.202...

  4. Pathways in STEM: Factors affecting the retention and attrition of talented men and women from the STEM pipeline

    Science.gov (United States)

    Heilbronner, Nancy N.

    Many men and women who are talented in science, technology, engineering, and/or mathematics (STEM) choose not to pursue undergraduate majors or careers in these fields. To develop talents in STEM, educators must understand the factors that contribute to an individual's retention in STEM domains, as well as the factors that act as barriers to success, such as the role that gender plays in the underrepresentation of women in certain STEM fields (e.g., computer science and engineering) and changes in recent decades in the process of selecting STEM majors and careers. The purpose of this study was to explore the influences that guide decisions related to the selection of majors and occupations during high school, post-secondary education, and early careers. Survey methodology was used to explore the perceptions of 360 Science Talent Search (STS) semifinalists and finalists during the years 1987-1989 and 1997-1999, and quantitative procedures were used to analyze the data. A majority (74.2%) of STS participants majored in a STEM field in college, and most (68.6%) currently work in a STEM field. A greater percentage of men selected computer science, engineering, physics, and mathematics majors, and a greater percentage of women selected biological science and chemistry. Belief in one's ability to achieve in STEM was a predictor of STEM majors in college and STEM concentrations in graduate school, but differences were found between men's and women's self-efficacy in STEM during high school and in college, as women had lower self-efficacy. Sex was a predictor of STEM majors in college, but perceived quality of academic courses was not. STEM majors also reported more satisfaction with their STEM courses in high school and college than non-STEM majors. In a departure from the results of previous research, the reasons that men and women selected occupations were similar, as were the reasons they chose to leave or not to enter STEM. The most frequently cited reason for

  5. Chemical profile and antioxidant capacity verification of Psidium guajava (Myrtaceae) fruits at different stages of maturation.

    Science.gov (United States)

    Araújo, Heverton M; Rodrigues, Fabíola F G; Costa, Wégila D; Nonato, Carla de F A; Rodrigues, Fábio F G; Boligon, Aline A; Athayde, Margareth L; Costa, José G M

    2015-01-01

    Psidium guajava (Myrtaceae), a common plant in Cariri region, Ceara, Brazil, as well as in various parts of the world, contains high concentrations of bioactive compounds and in many communities its parts are used for therapeutic purposes. Studies describe antioxidant, antimicrobial and anti-diarrheal actions from extracts obtained from leaves, but information about the activities of the fruits and comparison of these at different maturity stages (immature, partially mature and mature) are scarce. This study aims to evaluate the antioxidant properties by quantifying the levels of phenolic and flavonoid compounds, carotenoids and vitamin C of P. guajava fruits at different stages of maturation. The content of phenolic compounds for the immature fruit, partially mature and mature were: 22.41; 34.61 and 32.92 mg of AG/g fraction. The flavonoid content for immature fruits, intermediate and mature were: 2.83; 5.10 and 5.65 mg RUT/g fraction, respectively. Following the same standards of maturation stages, the ascorbic acid content was determined with values of 0.48; 0.38 and 0.21 mg AA/g fraction, respectively. HPLC analysis identified and quantified the presence of gallic acid, catechin, chlorogenic acid, caffeic acid, epicatechin, rutin, quercitrin, isoquercitrin, quercetin, kaempferol, glycosylated campeferol, tocopherol, β-carotene and lycopene. The antioxidant activity carried out by DPPH method showed the mature fruits bearing the best results, whereas chelation of Fe2+ ions showed higher percentage for the immature fruit. The results obtained by lipidic peroxidation were not satisfactory.

  6. MicroRNA expression profiles of cancer stem cells in head and neck squamous cell carcinoma

    OpenAIRE

    YATA, KAZUYA; BEDER, LEVENT BEKIR; TAMAGAWA, SHUNJI; HOTOMI, MUNEKI; HIROHASHI, YOSHIHIKO; GRENMAN, REIDAR; YAMANAKA, NOBORU

    2015-01-01

    Increasing evidence indicates that cancer stem cells have essential roles in tumor initiation, progression, metastasis and resistance to chemo-radiation. Recent research has pointed out biological importance of microRNAs in cancer stem cell dysregulation. Total number of mature microRNAs in human genome increased to more than 2,500 with the recent up-date of the database. However, currently no information is available regarding microRNA expression profiles of cancer stem cells in head and nec...

  7. Integration of genomics, proteomics, and imaging for cardiac stem cell therapy

    International Nuclear Information System (INIS)

    Chun, Hyung J.; Wilson, Kitch O.; Huang, Mei; Wu, Joseph C.

    2007-01-01

    Cardiac stem cell therapy is beginning to mature as a valid treatment for heart disease. As more clinical trials utilizing stem cells emerge, it is imperative to establish the mechanisms by which stem cells confer benefit in cardiac diseases. In this paper, we review three methods - molecular cellular imaging, gene expression profiling, and proteomic analysis - that can be integrated to provide further insights into the role of this emerging therapy. (orig.)

  8. Fitness consequences of cotyledon and mature-leaf damage in the ivyleaf morning glory.

    Science.gov (United States)

    Stinchcombe, John R

    2002-04-01

    To understand the evolutionary and ecological consequences of natural enemy damage to plants, it is essential to determine how the fitness effects of damage differ depending on the tissues damaged and the subsequent pattern of damage. In a field experiment with the ivyleaf morning glory, the direct and indirect effects on fitness of herbivore damage to cotyledons and mature leaves was evaluated. Damage to mature leaves had negligible direct effects on fitness and no indirect effects on fitness through other correlated traits. Damage to cotyledons also did not directly affect fitness, but did so indirectly through its effects on plant size. These findings suggest that increased resistance to cotyledon damage or increased compensatory growth following cotyledon damage could be effective strategies for plants of this species to counteract the negative effects of herbivory.

  9. System for tracking transplanted limbal epithelial stem cells in the treatment of corneal stem cell deficiency

    Science.gov (United States)

    Boadi, J.; Sangwal, V.; MacNeil, S.; Matcher, S. J.

    2015-03-01

    The prevailing hypothesis for the existence and healing of the avascular corneal epithelium is that this layer of cells is continually produced by stem cells in the limbus and transported onto the cornea to mature into corneal epithelium. Limbal Stem Cell Deficiency (LSCD), in which the stem cell population is depleted, can lead to blindness. LSCD can be caused by chemical and thermal burns to the eye. A popular treatment, especially in emerging economies such as India, is the transplantation of limbal stem cells onto damaged limbus with hope of repopulating the region. Hence regenerating the corneal epithelium. In order to gain insights into the success rates of this treatment, new imaging technologies are needed in order to track the transplanted cells. Optical Coherence Tomography (OCT) is well known for its high resolution in vivo images of the retina. A custom OCT system has been built to image the corneal surface, to investigate the fate of transplanted limbal stem cells. We evaluate two methods to label and track transplanted cells: melanin labelling and magneto-labelling. To evaluate melanin labelling, stem cells are loaded with melanin and then transplanted onto a rabbit cornea denuded of its epithelium. The melanin displays strongly enhanced backscatter relative to normal cells. To evaluate magneto-labelling the stem cells are loaded with magnetic nanoparticles (20-30nm in size) and then imaged with a custom-built, magneto-motive OCT system.

  10. Maturity group classification and maturity locus genotyping of early-maturing soybean varieties from high-latitude cold regions.

    Science.gov (United States)

    Jia, Hongchang; Jiang, Bingjun; Wu, Cunxiang; Lu, Wencheng; Hou, Wensheng; Sun, Shi; Yan, Hongrui; Han, Tianfu

    2014-01-01

    With the migration of human beings, advances of agricultural sciences, evolution of planting patterns and global warming, soybeans have expanded to both tropical and high-latitude cold regions (HCRs). Unlike other regions, HCRs have much more significant and diverse photoperiods and temperature conditions over seasons or across latitudes, and HCR soybeans released there show rich diversity in maturity traits. However, HCR soybeans have not been as well classified into maturity groups (MGs) as other places. Therefore, it is necessary to identify MGs in HCRs and to genotype the maturity loci. Local varieties were collected from the northern part of Northeast China and the far-eastern region of Russia. Maturity group reference (MGR) soybeans of MGs MG000, MG00, and MG0 were used as references during field experiments. Both local varieties and MGR soybeans were planted for two years (2010-2011) in Heihe (N 50°15', E 127°27', H 168.5 m), China. The days to VE (emergence), R1 (beginning bloom) and R7 (beginning maturity) were recorded and statistically analyzed. Furthermore, some varieties were further genotyped at four molecularly-identified maturity loci E1, E2, E3 and E4. The HCR varieties were classified into MG0 or even more early-maturing. In Heihe, some varieties matured much earlier than MG000, which is the most early-maturing known MG, and clustered into a separate group. We designated the group as MG0000, following the convention of MGs. HCR soybeans had relatively stable days to beginning bloom from emergence. The HCR varieties diversified into genotypes of E1, E2, E3 and E4. These loci had different effects on maturity. HCRs diversify early-maturing MGs of soybean. MG0000, a new MG that matures much earlier than known MGs, was developed. HCR soybean breeding should focus more on shortening post-flowering reproductive growth. E1, E2, E3, and E4 function differentially.

  11. Human cytomegalovirus alters localization of MHC class II and dendrite morphology in mature Langerhans cells.

    Science.gov (United States)

    Lee, Andrew W; Hertel, Laura; Louie, Ryan K; Burster, Timo; Lacaille, Vashti; Pashine, Achal; Abate, Davide A; Mocarski, Edward S; Mellins, Elizabeth D

    2006-09-15

    Hemopoietic stem cell-derived mature Langerhans-type dendritic cells (LC) are susceptible to productive infection by human CMV (HCMV). To investigate the impact of infection on this cell type, we examined HLA-DR biosynthesis and trafficking in mature LC cultures exposed to HCMV. We found decreased surface HLA-DR levels in viral Ag-positive as well as in Ag-negative mature LC. Inhibition of HLA-DR was independent of expression of unique short US2-US11 region gene products by HCMV. Indeed, exposure to UV-inactivated virus, but not to conditioned medium from infected cells, was sufficient to reduce HLA-DR on mature LC, implicating particle binding/penetration in this effect. Reduced surface levels reflected an altered distribution of HLA-DR because total cellular HLA-DR was not diminished. Accumulation of HLA-DR was not explained by altered cathepsin S activity. Mature, peptide-loaded HLA-DR molecules were retained within cells, as assessed by the proportion of SDS-stable HLA-DR dimers. A block in egress was implicated, as endocytosis of surface HLA-DR was not increased. Immunofluorescence microscopy corroborated the intracellular retention of HLA-DR and revealed markedly fewer HLA-DR-positive dendritic projections in infected mature LC. Unexpectedly, light microscopic analyses showed a dramatic loss of the dendrites themselves and immunofluorescence revealed that cytoskeletal elements crucial for the formation and maintenance of dendrites are disrupted in viral Ag-positive cells. Consistent with these dendrite effects, HCMV-infected mature LC exhibit markedly reduced chemotaxis in response to lymphoid chemokines. Thus, HCMV impedes MHC class II molecule trafficking, dendritic projections, and migration of mature LC. These changes likely contribute to the reduced activation of CD4+ T cells by HCMV-infected mature LC.

  12. Coordination of leaf and stem water transport properties in tropical forest trees

    Science.gov (United States)

    Frederick C. Meinzer; David R. Woodruff; Jean-Christophe Domec; Guillermo Goldstein; Paula I. Campanello; Genoveva M. Gatti; Randol Villalobos-Vega

    2008-01-01

    Stomatal regulation of transpiration constrains leaf water potential (ψ l) within species-specific ranges that presumably avoid excessive tension and embolism in the stem xylem upstream. However, the hydraulic resistance of leaves can be highly variable over short time scales, uncoupling tension in the xylem of leaves from that in the...

  13. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    Energy Technology Data Exchange (ETDEWEB)

    Olbrich, Maren, E-mail: maren.olbrich@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Gerstner, Elke; Bahnweg, Guenther [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Matyssek, Rainer [Technische Universitaet Muenchen, Ecophysiology of Plants, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Heller, Werner; Ernst, Dieter [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  14. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    International Nuclear Information System (INIS)

    Olbrich, Maren; Gerstner, Elke; Bahnweg, Guenther; Haeberle, Karl-Heinz; Matyssek, Rainer; Welzl, Gerhard; Heller, Werner; Ernst, Dieter

    2010-01-01

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  15. Assessment of Grewia oppositifolia leaves as crude protein supplement to low-quality forage diets of sheep.

    Science.gov (United States)

    Khan, Nazir Ahmad; Habib, Ghulam

    2012-10-01

    In the tropical arid and semi-arid regions of many developing countries, sheep are predominantly grazed on low-quality pastures and stall-fed on crop residues. This study evaluated the potential of Grewia oppositifolia tree leaves as crude protein (CP) supplement to the low-quality diets of sheep in comparison with cottonseed cake (CSC). Changes in the chemical composition of the leaves with progressive maturation (December to March) were studied. The leaves maintained a high CP content (>164 g/kg dry matter (DM)) during the prolonged maturation in the winter feed scarcity period. The leaves were rich in Ca (41 g/kg DM) and K (89 g/kg DM). The rate of degradation and effective degradability of CP were consistently higher (P < 0.001) in CSC than in G. oppositifolia. A balance trial in a 4 × 4 Latin square design with four mature Ramghani wethers showed that DM intake, DM and CP digestibility, and N retention did not differ with the substitution of CSC with G. oppositifolia leaves, as a supplement to a basal diet of sorghum hay. Body weight (BW) gain and wool yield responses to the supplements were examined with 36 lambs (27 ± 3 kg BW; age 11 ± 1 months) for 15 weeks. The lambs were only grazed on local pasture (control group) or supplemented with CSC, G. oppositifolia leaves, and their mixture on iso-N basis. Addition of the supplements increased (P < 0.05) BW gain and wool yield, and the leaves were as effective as CSC. These results demonstrated that G. oppositifolia leaves provide good quality green fodder during the prolonged winter feed scarcity period, and that the leaves can be efficiently utilized as a CP supplement to the low-quality diets of sheep.

  16. The maturity of Nuclear Law

    International Nuclear Information System (INIS)

    Martinez Favini, J.A.

    1985-01-01

    The ever-increasing use of atomic energy since 1950 has generated a set of rules called for practical reasons Nuclear Law. This branch of law covers a wide scope of related activities and, specialized studies have apparently foreseen all conceivable hypotheses. The international character of Nuclear Law explains the basic harmony of international legislation. The methods of comparative Law and International Private Law as well as the joint, indepth work of scientists and jurists will bring about steady progress towards legislative unity and prompt solution to conflicts. The expectable revitalization of nuclear-electric programs early in the 21st. century will give rise to a Nuclear juridical community which can already be perceived through the maturity Nuclear Law has reached. (Author) [es

  17. Differentiation of oligodendrocyte progenitor cells from dissociated monolayer and feeder-free cultured pluripotent stem cells.

    Science.gov (United States)

    Yamashita, Tomoko; Miyamoto, Yuki; Bando, Yoshio; Ono, Takashi; Kobayashi, Sakurako; Doi, Ayano; Araki, Toshihiro; Kato, Yosuke; Shirakawa, Takayuki; Suzuki, Yutaka; Yamauchi, Junji; Yoshida, Shigetaka; Sato, Naoya

    2017-01-01

    Oligodendrocytes myelinate axons and form myelin sheaths in the central nervous system. The development of therapies for demyelinating diseases, including multiple sclerosis and leukodystrophies, is a challenge because the pathogenic mechanisms of disease remain poorly understood. Primate pluripotent stem cell-derived oligodendrocytes are expected to help elucidate the molecular pathogenesis of these diseases. Oligodendrocytes have been successfully differentiated from human pluripotent stem cells. However, it is challenging to prepare large amounts of oligodendrocytes over a short amount of time because of manipulation difficulties under conventional primate pluripotent stem cell culture methods. We developed a proprietary dissociated monolayer and feeder-free culture system to handle pluripotent stem cell cultures. Because the dissociated monolayer and feeder-free culture system improves the quality and growth of primate pluripotent stem cells, these cells could potentially be differentiated into any desired functional cells and consistently cultured in large-scale conditions. In the current study, oligodendrocyte progenitor cells and mature oligodendrocytes were generated within three months from monkey embryonic stem cells. The embryonic stem cell-derived oligodendrocytes exhibited in vitro myelinogenic potency with rat dorsal root ganglion neurons. Additionally, the transplanted oligodendrocyte progenitor cells differentiated into myelin basic protein-positive mature oligodendrocytes in the mouse corpus callosum. This preparative method was used for human induced pluripotent stem cells, which were also successfully differentiated into oligodendrocyte progenitor cells and mature oligodendrocytes that were capable of myelinating rat dorsal root ganglion neurons. Moreover, it was possible to freeze, thaw, and successfully re-culture the differentiating cells. These results showed that embryonic stem cells and human induced pluripotent stem cells maintained in a

  18. In vitro differentiation of primordial germ cells and oocyte-like cells from stem cells.

    Science.gov (United States)

    Costa, José J N; Souza, Glaucinete B; Soares, Maria A A; Ribeiro, Regislane P; van den Hurk, Robert; Silva, José R V

    2018-02-01

    Infertility is the result of failure due to an organic disorder of the reproductive organs, especially their gametes. Recently, much progress has been made on generating germ cells, including oocytes, from various types of stem cells. This review focuses on advances in female germ cell differentiation from different kinds of stem cells, with emphasis on embryonic stem cells, adult stem cells, and induced pluripotent stem cells. The advantages and disadvantages of the derivation of female germ cells from several types of stem cells are also highlighted, as well as the ability of stem cells to generate mature and functional female gametes. This review shows that stem cell therapies have opened new frontiers in medicine, especially in the reproductive area, with the possibility of regenerating fertility.

  19. Do ray cells provide a pathway for radial water movement in the stems of conifer trees?

    Science.gov (United States)

    David M. Barnard; Barbara Lachenbruch; Katherine A. McCulloh; Peter Kitin; Frederick C. Meinzer

    2013-01-01

    The pathway of radial water movement in tree stems presents an unknown with respect to whole-tree hydraulics. Radial profiles have shown substantial axial sap flow in deeper layers of sapwood (that may lack direct connection to transpiring leaves), which suggests the existence of a radial pathway for water movement. Rays in tree stems include ray tracheids and/or ray...

  20. Reinforcement of Bacillus subtilis spores by cross-linking of outer coat proteins during maturation.

    Science.gov (United States)

    Abhyankar, Wishwas; Pandey, Rachna; Ter Beek, Alexander; Brul, Stanley; de Koning, Leo J; de Koster, Chris G

    2015-02-01

    Resistance characteristics of bacterial endospores towards various environmental stresses such as chemicals and heat are in part attributed to their coat proteins. Heat resistance is developed in a late stage of sporulation and during maturation of released spores. Using our gel-free proteomic approach and LC-FT-ICR-MS/MS analysis we have monitored the efficiency of the tryptic digestion of proteins in the coat during spore maturation over a period of eight days, using metabolically (15)N labeled mature spores as reference. The results showed that during spore maturation the loss of digestion efficiency of outer coat and crust proteins synchronized with the increase in heat resistance. This implicates that spore maturation involves chemical cross-linking of outer coat and crust layer proteins leaving the inner coat layer proteins unmodified. It appears that digestion efficiencies of spore surface proteins can be linked to their location within the coat and crust layers. We also attempted to study a possible link between spore maturation and the observed heterogeneity in spore germination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Screening of Bread Wheat Genotypes for Stem Reserves Remobilization, Relative Water Content and Osmotic Adjustment under Drought Stress

    Directory of Open Access Journals (Sweden)

    Z Soleimani

    2015-05-01

    Full Text Available Drought one of the most important global threats against bread wheat production. In order to identify physiological traits associated with drought tolerance, 52 bread wheat varieties were cultured under two normal and drought stress condition in a randomized complete block desigen with three replications. RWC (in three independent times, leaf rolling, leaf silvering, days to flowering, days to maturity and stem reserve remobilization were investigeted. Also in a pot experiment osmotic adjustment of the varieties were measured at seedling stage. varieties Star and Bezostaya had the highest RWC (0.79 and 0.78, respectively. Osmotic adjustment in Rasol and Unknown11 were highest (0.58 and 0.56, respectively. Varieties Tipik, Unknown11 and Azar2 showed the least decrease in thousand grain weight after spraying with KI (4.8, 5.5 and 5.5, respectively. Also varieties Dez, Gaspard and MV-17 have the highest degree of leaf silvering and varieties Niknejad, Star and Kohdasht under drought stress were able than the other varieties bring their leaves to form a rolling and cope with water deficit. Under drought stress, Varieties Alborz, Zagros and Inia were observed premature than the other varieties and Gaspard and Kaslojen varieties were observed late mature than the other varieties. Altogetehr varieties Kohdasht, Star and Bezostaya can be used as genetic resources for leaf water retention under drought stress condition for imjproving other varieties. Also as Azar2 and Unknown11 had highest amount of thousand grain weight under normal condition and simoultanously showed high ability in stem reserves remobilization they can be selected as parents in crosses for improving these traits.

  2. Potency of Stem Cells

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Potency of Stem Cells. Totipotent Stem Cells (Zygote + first 2 divisions). -Can form placenta, embryo, and any cell of the body. Pluripotent (Embryonic Stem Cells). -Can form any cell of the body but can not form placenta, hence no embryo. Multipotent (Adult stem cells).

  3. A maturity model for blockchain adoption

    OpenAIRE

    Wang, Huaiqing; Chen, Kun; Xu, Dongming

    2016-01-01

    Background: The rapid development of the blockchain technology and its various applications has rendered it important to understand the guidelines for adopting it. Methods: The comparative analysis method is used to analyze different dimensions of the maturity model, which is mainly based on the commonly used capability maturity model. Results: The blockchain maturity model and its adoption process have been discussed and presented. Conclusions: This study serves as a guide to institutions to...

  4. Lack of incorporation of tritiated uridine by nuclei of mature sieve elements in Metasequoia glyptostroboides and Sequoiadendron giganteum.

    Science.gov (United States)

    Hébant, C

    1975-01-01

    The majority of nuclei which persist in "mature" sieve elements of Metasequoia glyptostroboides Hu and Chen and Sequoiadendron giganteum Buchholz fail to incorporate tritiated uridine (10 μCi/ml; 7 hours incubation of stem fragments). This is interpreted as further evidence for the degenerated condition of these nuclei.

  5. A Set Theoretical Approach to Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester; Vatrapu, Ravi; Andersen, Kim Normann

    2016-01-01

    characterized by equifinality, multiple conjunctural causation, and case diversity. We prescribe methodological guidelines consisting of a six-step procedure to systematically apply set theoretic methods to conceptualize, develop, and empirically derive maturity models and provide a demonstration......Maturity Model research in IS has been criticized for the lack of theoretical grounding, methodological rigor, empirical validations, and ignorance of multiple and non-linear paths to maturity. To address these criticisms, this paper proposes a novel set-theoretical approach to maturity models...

  6. Leaving the hospital - your discharge plan

    Science.gov (United States)

    ... patientinstructions/000867.htm Leaving the hospital - your discharge plan To use the sharing features on this page, ... once you leave. This is called a discharge plan. Your health care providers at the hospital will ...

  7. Exposure of the mouse perinatal testis to radiation leads to hypospermia at sexual maturity

    International Nuclear Information System (INIS)

    Forand, A.; Messiaen, S.; Habert, R.; Bernardino-Sgherri, J.

    2009-01-01

    The first round of mouse spermatogenesis begins from 3 to 4 days after birth through differentiation of gonocytes into spermatogonial-stem cells and type A spermatogonia. Consequently, this step of differentiation may determine generation of the original population of stem cells and the fertility potential of the adult mouse. We aimed to determine the effect of perinatal exposure to ionizing radiation on the testis at the end of the first wave of spermatogenesis and at sexual maturity. Our results show that, radiation sensitivity of the testis substantially decreases from late foetal life to the end of the first week after birth. In addition, partial or full recovery from radiation induced testicular weight loss occurred between the first round of spermatogenesis and sexual maturity, and this was associated with the stimulation of spermatogonial proliferation. Exposure of mice at 17.5 days after conception or at 1 day after birth to γ-rays decreased the sperm counts at sexual maturity, while exposure of 8 day-old mice had no effect. This suggests that irradiation of late foetal or early neonatal testes has a direct impact on the generation of the neonatal spermatogonial-stem cell pool. (authors)

  8. Does Postsecondary Persistence in STEM Vary by Gender?

    Directory of Open Access Journals (Sweden)

    Barbara King

    2016-09-01

    Full Text Available The underrepresentation of women in science, technology, engineering, and mathematics (STEM is often explained by women’s greater likelihood to leave STEM at each key juncture from elementary school into the workforce. It is important to examine this more closely and look for points in the pipeline where gender equity exists. This study uses nationally representative data from a recent cohort of college students to investigate thoroughly gender differences in STEM persistence. Results indicate that no significant gender differences in persistence exist. This finding holds among those in computer science, engineering, mathematics, and physical science, and for those in life science. Additionally, the results are unchanged if the sample is limited to degree earners and are robust to the inclusion of individual and institutional variables. Although it is clear that women are less likely to choose certain STEM majors, those who do are no less likely to earn a STEM degree.

  9. Childcare and the division of parental leave

    OpenAIRE

    Norén, Anna

    2015-01-01

    Despite several policies aimed at increasing fathers' participation in the caring of children, Swedish mothers still use the bulk of the paid parental leave which may have several negative consequences for the family e.g. in terms of weaker labor market attachment for the mother. Division of parental leave is likely affected by how parents value the costs associated with parental leave. I investigate whether a reduction in the care burden, or a decreased non-monetary cost, of parental leave t...

  10. Springtime Leaf Development of Mature Sessile Oak Trees as Based on Multi-Seasonal Monitoring Data

    Directory of Open Access Journals (Sweden)

    NYITRAI, Balázs

    2012-01-01

    Full Text Available Based on a four year leaf growth data-set we modelled the thermal time-dependent leafontogeny in upper and lower canopy layers of mature sessile oak trees, in a Quercetum petraeae-cerrisforest stand (NE Hungary. Our regression models revealed no considerable differences between thetiming of leaf unfolding and leaf expansion of different canopy layers. On the other hand seasonalcourse in leaf mass-to-area ratio (LMA indicated that sun leaves needed considerably longer thermaltime to fully develop their anatomical structures compared to shade leaves. LMA of sun leaves washigher during the whole leaf maturation process suggesting that ‘sun’ and ‘shade’ characteristicsdevelop in very early stage of leaf ontogeny. Functioning of photosynthetic apparatus (Fv/Fo in shadeleaves have built up faster and performed better in all developmental stages which could be attributedto two main factors: 1 very early determination of leaf traits as a function of light environment and 2evolving shading effect of upper canopy layer eliminates photoinhibition in lower leaves.

  11. Decoupled leaf and stem economics in rain forest trees

    NARCIS (Netherlands)

    Baraloto, C.; Paine, C.E.T.; Poorter, L.; Beauchene, J.; Bonal, D.; Domenach, A.M.; Herault, B.; Patiño, S.; Roggy, J.C.; Chave, J.

    2010-01-01

    Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by

  12. Hyperglycemic effect and hypertotoxicity studies of stem bark of ...

    African Journals Online (AJOL)

    Serum AST, ALT, ALP, glucose, bilirubin (total and direct) showed significant increase (P<0.05) in groups B and C rats but were lower than those of group A. The results indicate that the extract of Khaya senegalensis stem bark and highland (green) tea leaves caused increased activity of the liver enzymes studied which is ...

  13. The influence of stages of maturity on the agronomic traits of fibre flax introduced varieties

    Directory of Open Access Journals (Sweden)

    Jasminka Butorac

    2018-03-01

    Full Text Available The harvest time of fibre flax is influenced by climatic conditions, varieties, stages of maturity and the crop’s final use. In addition, the time of harvesting of fibre flax affects the quality of the fibres. Fibre flax can be harvested in few stages of maturity. So, this paper presents the influence of three stages of maturity (green, yellow and full ripening on the agronomic traits (stem yield, stem yield after retting, total fibre yield, share of total fibre, long fibre yield, share of long fibre of five fibre flax varieties. Varieties trials with fibre flax were set up in two years (2010-2011 and in two locations: at the experimental fields of the Faculty of Agriculture in Zagreb on eutric cambisol and of the College of Agriculture at Križevci on pseudogley on level terrain. The trials were carried out according to the randomized complete block design (RCBD with four replications. According to the results of the two-years research into the agronomic traits of fibre flax, significant differences were established among the varieties and among the stages of maturity under study. The varieties Agatha, Viola and Electra recorded higher values of investigated traits. All varieties achieved higher values of investigated traits at Križevci (production on heavier soil in which some of winter moisture remained available in spring months. The highest values of investigated traits were recorded when the fibre flax were harvested in the green ripening.

  14. The CCCTB Rules on Leaving a Group

    NARCIS (Netherlands)

    van de Streek, J.

    2012-01-01

    The consolidation system proposed in the draft of the CCCTB Directive puts relationships between Member States on edge. This is clearly apparent in the rules that apply when a company leaves a group. In this article the leaving rules are examined. Although the leaving rules are claimed to be

  15. Sugar beet leaves for functional ingredients

    NARCIS (Netherlands)

    Tamayo Tenorio, Angelica

    2017-01-01

    Plant leaves are recognised as a potential source for food applications based on their nutritional profile and interesting technological properties of leaf components, and based on the large availability of plant leaves in agricultural waste streams. Besides proteins, leaves have a rich

  16. Compassionate Care Leave & Benefits. CAUT Briefing Note

    Science.gov (United States)

    Canadian Association of University Teachers, 2016

    2016-01-01

    Compassionate care leave and benefits were introduced in 2003/04 to help employees cope with this difficult work-life balance challenge. Employment Standards legislation and the Employment Insurance program (EI) were amended to provide leave without pay, with payment of EI benefits for compassionate care leave. Collective agreements have been…

  17. On the Sharing of Temporary Parental Leave

    DEFF Research Database (Denmark)

    Amilon, Anna

    2007-01-01

    This paper views temporary parental leave (leave from work to take care of a sick child) as a household public good, produced with time inputs of the parents as the only input. Assuming equal productivities in the production of temporary parental leave and equal utility functions of the spouses...

  18. The maturing of microbial ecology.

    Science.gov (United States)

    Schmidt, Thomas M

    2006-09-01

    A.J. Kluyver and C.B. van Niel introduced many scientists to the exceptional metabolic capacity of microbes and their remarkable ability to adapt to changing environments in The Microbe's Contribution to Biology. Beyond providing an overview of the physiology and adaptability of microbes, the book outlined many of the basic principles for the emerging discipline of microbial ecology. While the study of pure cultures was highlighted, provided a unifying framework for understanding the vast metabolic potential of microbes and their roles in the global cycling of elements, extrapolation from pure cultures to natural environments has often been overshadowed by microbiologists inability to culture many of the microbes seen in natural environments. A combination of genomic approaches is now providing a culture-independent view of the microbial world, revealing a more diverse and dynamic community of microbes than originally anticipated. As methods for determining the diversity of microbial communities become increasingly accessible, a major challenge to microbial ecologists is to link the structure of natural microbial communities with their functions. This article presents several examples from studies of aquatic and terrestrial microbial communities in which culture and culture-independent methods are providing an enhanced appreciation for the microbe's contribution to the evolution and maintenance of life on Earth, and offers some thoughts about the graduate-level educational programs needed to enhance the maturing field of microbial ecology.

  19. Motivational maturity and helping behavior.

    Science.gov (United States)

    Haymes, M; Green, L

    1977-12-01

    This study was undertaken to examine the independent influences of conative development (the Maslow needs hierarchy) upon behavioral aspects of prosocial orientations. It provides a behavioral demonstration of conative effects in a helping paradigm, among college-age men. A comparison of the conative data across the ages of 15-22 provided a cross-sectional view of conative development itself. Conative maturity was found to be predictive of greater helping among college-age men. Situational demands were demonstrated which tended to mask, but not override, these predispositional influences on helping. The cross-sectional data on conative development point to probable movement to early esteem concerns among high school men who have reached the conative level of love and belonging. On the other hand, the stability across the years of 15-22 of proportion of safety concerns suggests fixation of such concerns in those exhibiting them in high school. Results are discussed in terms of conative growth for development of prosocial orientations.

  20. Smart Grid Interoperability Maturity Model

    Energy Technology Data Exchange (ETDEWEB)

    Widergren, Steven E.; Levinson, Alex; Mater, J.; Drummond, R.

    2010-04-28

    The integration of automation associated with electricity resources (including transmission and distribution automation and demand-side resources operated by end-users) is key to supporting greater efficiencies and incorporating variable renewable resources and electric vehicles into the power system. The integration problems faced by this community are analogous to those faced in the health industry, emergency services, and other complex communities with many stakeholders. To highlight this issue and encourage communication and the development of a smart grid interoperability community, the GridWise Architecture Council (GWAC) created an Interoperability Context-Setting Framework. This "conceptual model" has been helpful to explain the importance of organizational alignment in addition to technical and informational interface specifications for "smart grid" devices and systems. As a next step to building a community sensitive to interoperability, the GWAC is investigating an interoperability maturity model (IMM) based on work done by others to address similar circumstances. The objective is to create a tool or set of tools that encourages a culture of interoperability in this emerging community. The tools would measure status and progress, analyze gaps, and prioritize efforts to improve the situation.

  1. Antenatal assessment of fetal maturity

    International Nuclear Information System (INIS)

    Gerstner, G.; Reinold, E.; Wolf, G.

    1979-01-01

    334 ultrasound-cephalometries and 231 X-ray fetographies were performed for antenatal assessment of fetal maturity as well as for exact estimation of gestational age in women with unknown date of confinement. The accuracy of the predictions was compared. Ultrasound-cephalometry gave best results when performed until the 20th week of gestation. A correct prediction was obtained in 80.4% of cases. After the 20th week of gestation, the accuracy of prediction decreased. Radiology on the contrary gave optimal results at the end of pregnancy. A correct prediction of the date of confinement was obtained in 73.8% of cases, when the X-ray fetography was performed between the 37th and 40th week of gestation. At the end of gestation radiography should be performed, if there is a discrepancy between ultrasound and clinical estimation or if ultrasound-cephalometry was not carried out in early pregnancy - especially if induction of labour is necessary. (author)

  2. Immunological characteristics of mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Cíntia de Vasconcellos Machado

    2013-01-01

    Full Text Available Although bone marrow is the main source, mesenchymal stem cells have already been isolated from various other tissues, such as the liver, pancreas, adipose tissue, peripheral blood and dental pulp. These plastic adherent cells are morphologically similar to fibroblasts and have a high proliferative potential. This special group of cells possesses two essential characteristics: self-renewal and differentiation, with appropriate stimuli, into various cell types. Mesenchymal stem cells are considered immunologically privileged, since they do not express costimulatory molecules, required for complete T cell activation, on their surface. Several studies have shown that these cells exert an immunosuppressive effect on cells from both innate and acquired immunity systems. Mesenchymal stem cells can regulate the immune response in vitro by inhibiting the maturation of dendritic cells, as well as by suppressing the proliferation and function of T and B lymphocytes and natural killer cells. These special properties of mesenchymal stem cells make them a promising strategy in the treatment of immune mediated disorders, such as graft-versus-host disease and autoimmune diseases, as well as in regenerative medicine. The understanding of immune regulation mechanisms of mesenchymal stem cells, and also those involved in the differentiation of these cells in various lineages is primordial for their successful and safe application in different areas of medicine.

  3. Human stem cells for craniomaxillofacial reconstruction.

    Science.gov (United States)

    Jalali, Morteza; Kirkpatrick, William Niall Alexander; Cameron, Malcolm Gregor; Pauklin, Siim; Vallier, Ludovic

    2014-07-01

    Human stem cell research represents an exceptional opportunity for regenerative medicine and the surgical reconstruction of the craniomaxillofacial complex. The correct architecture and function of the vastly diverse tissues of this important anatomical region are critical for life supportive processes, the delivery of senses, social interaction, and aesthetics. Craniomaxillofacial tissue loss is commonly associated with inflammatory responses of the surrounding tissue, significant scarring, disfigurement, and psychological sequelae as an inevitable consequence. The in vitro production of fully functional cells for skin, muscle, cartilage, bone, and neurovascular tissue formation from human stem cells, may one day provide novel materials for the reconstructive surgeon operating on patients with both hard and soft tissue deficit due to cancer, congenital disease, or trauma. However, the clinical translation of human stem cell technology, including the application of human pluripotent stem cells (hPSCs) in novel regenerative therapies, faces several hurdles that must be solved to permit safe and effective use in patients. The basic biology of hPSCs remains to be fully elucidated and concerns of tumorigenicity need to be addressed, prior to the development of cell transplantation treatments. Furthermore, functional comparison of in vitro generated tissue to their in vivo counterparts will be necessary for confirmation of maturity and suitability for application in reconstructive surgery. Here, we provide an overview of human stem cells in disease modeling, drug screening, and therapeutics, while also discussing the application of regenerative medicine for craniomaxillofacial tissue deficit and surgical reconstruction.

  4. Concise Review: Stem Cells in Osteoimmunology.

    Science.gov (United States)

    Fierro, Fernando A; Nolta, Jan A; Adamopoulos, Iannis E

    2017-06-01

    Bone remodeling is a lifelong process in which mature bone tissue is removed from the skeleton by bone resorption and is replenished by new during ossification or bone formation. The remodeling cycle requires both the differentiation and activation of two cell types with opposing functions; the osteoclast, which orchestrates bone resorption, and the osteoblast, which orchestrates bone formation. The differentiation of these cells from their respective precursors is a process which has been overshadowed by enigma, particularly because the precise osteoclast precursor has not been identified and because the identification of skeletal stem cells, which give rise to osteoblasts, is very recent. Latest advances in the area of stem cell biology have enabled us to gain a better understanding of how these differentiation processes occur in physiological and pathological conditions. In this review we postulate that modulation of stem cells during inflammatory conditions is a necessary prerequisite of bone remodeling and therefore an essential new component to the field of osteoimmunology. In this context, we highlight the role of transcription factor nuclear factor of activated T cells cytoplasmic 1 (NFATc1), because it directly links inflammation with differentiation of osteoclasts and osteoblasts. Stem Cells 2017;35:1461-1467. © 2017 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  5. Características de produção e qualidade nutricional de genótipos de capim- colonião colhidos em três estádios de maturidade Characteristics of nutritional quality and production of genotypes of guineagrass harvested in three maturity stages

    Directory of Open Access Journals (Sweden)

    Samuel dos Santos Stabile

    2010-07-01

    were considered as the plots, and the genotypes were considered as the sub- plots. Dry matter yield differed among the genotypes only at 90 days of growth, but the percentage of leaves, stems, and senesced material changed at 60 days of growth, as well as at 90 days of growth. Differently from what was observed for the leaves, chemical composition and digestibility of stem showed great variability among genotypes. The stem showed higher concentrations of neutral detergent fiber, acid detergent fiber, and lignin, and lower values of crude protein, when compared to the leaves. It also presented higher digestibility of dry matter at 60 days of growth, and higher digestibility of neutral detergent fiber at 30, and at 60 days of growth. Clustering of the cultivars identified the PM39 and PM47 genotypes as the most promising ones in the breeding program, because they showed high productivity and high nutritional quality. Maturity has little effect on leaf digestibility when compared to the stem. When participation of the stem increases in the total of dry matter, this component becomes the major factor limiting quality of forage plants. Therefore, breeding program must consider, in addition to leaf:stem ratio, the in vitro digestibility of neutral detergent fiber of the stem when selecting genotypes.

  6. Digital Maturity of the Firm's Business Model

    DEFF Research Database (Denmark)

    Groskovs, Sergejs; Vemula, Sreekanth

    We propose a digital maturity assessment model as an instrument for researchers and a strategic tool for managers. Existing literature lacks a conceptually clear way to measure the construct of digital maturity at the level of the firms business model. Our proposed instrument thus opens avenues f...

  7. A maturity model for industrial supply chains

    NARCIS (Netherlands)

    Hameri, A.P.; McKay, K.N.; Wiers, V.C.S.

    2013-01-01

    This article takes an evolutionary view of supply chains to suggest a series of distinct, contextual phases for supply chain execution and what maturity might mean at each phase. For example, what is best practice in a mature industry might not be best practice in a pioneering situation.Three

  8. 7 CFR 1421.101 - Maturity dates.

    Science.gov (United States)

    2010-01-01

    ... filed and disbursed except, for transferred marketing assistance loan collateral. The maturity date for transferred marketing assistance loan collateral will be the maturity date applicable to the original loan... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING...

  9. Cone and Seed Maturation of Southern Pines

    Science.gov (United States)

    James P. Barnett

    1976-01-01

    If slightly reduced yields and viability are acceptable, loblolly and slash cone collections can begin 2 to 3 weeks before maturity if the cones are stored before processing. Longleaf(P. palestris Mill.) pine cones should be collected only when mature, as storage decreased germination of seeds from immature cones. Biochemical analyses to determine reducing sugar...

  10. POSTTREATMENT NEUROBLASTOMA MATURATION TO GANGLIONIC CELL TUMOR

    Directory of Open Access Journals (Sweden)

    M. V. Ryzhova

    2012-01-01

    Full Text Available Tumor cells can differentiate into more mature forms in undifferentiated or poorly differentiated tumors, such as medulloblastomas with increased nodularity, as well as neuroblastomas. The authors describe 2 cases of neuroblastoma maturation into ganglioneuroblastoma 5 months after chemotherapy in a 2-year-old girl and 3 years after radiotherapy in a 16-year-old girl.

  11. Moving towards maturity in business model definitions

    DEFF Research Database (Denmark)

    Nielsen, Christian; Lund, Morten; Bukh, Per Nikolaj

    2014-01-01

    The field of business models has, as is the case with all emerging fields of practice, slowly matured through the development of frameworks, models, concepts and ideas over the last 15 years. New concepts, theories and models typically transcend a series of maturity phases. For the concept of Bus...

  12. Assessing the Harvest Maturity of Brazilian Mangoes

    NARCIS (Netherlands)

    Pereira, T.; Tijskens, L.M.M.; Vanoli, M.; Rizzolo, A.; Eccher Zerbini, P.C.; Torricelli, A.; Filgueiras, H.; Spinelli, L.

    2010-01-01

    No clear criterion exists to determine the optimum time to harvest mango. Some empirical relations are used to assess maturity, such as shoulder development. Moreover, as a result of the typical growing conditions in tropical climates, a huge variation in maturity and ripeness exists, seriously

  13. Decision-Making Style and Vocational Maturity.

    Science.gov (United States)

    Phillips, Susan D.; Strohmer, Douglas C.

    1982-01-01

    Examined the relationship between decision-making style, scholastic achievement, and vocational maturity for college students (N=64). Results did not support the hypothesized relationship between rationality and attitudinal and cognitive maturity. Scholastic achievement and lack of dependent decision style were found to be moderately predictive of…

  14. Correlation of Improved Version of Cervical Vertebral Maturation Indicator with Other Growth Maturity Indicators

    Directory of Open Access Journals (Sweden)

    Tripti Tikku

    2013-01-01

    Conclusion: The correlation between middle phalanx of 3rd finger (MP3 and cervical vertebral maturation method (CVMI and CVMS was higher as compared to the correlation of either of the cervical vertebral maturation method or MP3 with dental maturation indicator.

  15. Assessing healthcare process maturity: challenges of using a business process maturity model

    NARCIS (Netherlands)

    Tarhan, A.; Turetken, O.; van den Biggelaar, F.J.H.M.

    2015-01-01

    Doi: 10.4108/icst.pervasivehealth.2015.259105 The quality of healthcare services is influenced by the maturity of healthcare processes used to develop it. A maturity model is an instrument to assess and continually improve organizational processes. In the last decade, a number of maturity models

  16. Effects of juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics

    Science.gov (United States)

    Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of species are either unknown or limited to leaves and ground material from small stems. Therefore, the objective was to quantify nutritional ch...

  17. Mature Basin Development Portfolio Management in a Resource Constrained Environment

    International Nuclear Information System (INIS)

    Mandhane, J. M.; Udo, S. D.

    2002-01-01

    Nigerian Petroleum industry is constantly faced with management of resource constraints stemming from capital and operating budget, availability of skilled manpower, capacity of an existing surface facility, size of well assets, amount of soft and hard information, etceteras. Constrained capital forces the industry to rank subsurface resource and potential before proceeding with preparation of development scenarios. Availability of skilled manpower limits scope of integrated reservoir studies. Level of information forces technical and management to find low-risk development alternative in a limited time. Volume of either oil or natural gas or water or combination of them may be constrained due to design limits of the existing facility, or an external OPEC quota, requires high portfolio management skills.The first part of the paper statistically analyses development portfolio of a mature basin for (a) subsurface resources volume, (b) developed and undeveloped and undeveloped volumes, (c) sweating of wells, and (d) facility assets. The analysis presented conclusively demonstrates that the 80/20 is active in the statistical sample. The 80/20 refers to 80% of the effect coming from the 20% of the cause. The second part of the paper deals with how 80/20 could be applied to manage portfolio for a given set of constraints. Three application examples are discussed. Feedback on implementation of them resulting in focussed resource management with handsome rewards is documented.The statistical analysis and application examples from a mature basin form a way forward for a development portfolio management in an resource constrained environment

  18. Maturation processes and structures of small secreted peptides in plants

    Directory of Open Access Journals (Sweden)

    Ryo eTabata

    2014-07-01

    Full Text Available In the past decade, small secreted peptides have proven to be essential for various aspects of plant growth and development, including the maintenance of certain stem cell populations. Most small secreted peptides identified in plants to date are recognised by membrane-localized receptor kinases, the largest family of receptor proteins in the plant genome. This peptide-receptor interaction is essential for initiating intracellular signalling cascades. Small secreted peptides often undergo post-translational modifications and proteolytic processing to generate the mature peptides. Recent studies suggest that, in contrast to the situation in mammals, the proteolytic processing of plant peptides involves a number of complex steps. Furthermore, NMR-based structural analysis demonstrated that post-translational modifications induce the conformational changes needed for full activity. In this mini review, we summarise recent advances in our understanding of how small secreted peptides are modified and processed into biologically active peptides and describe the mature structures of small secreted peptides in plants.

  19. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  20. Set-Theoretic Approach to Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan

    Despite being widely accepted and applied, maturity models in Information Systems (IS) have been criticized for the lack of theoretical grounding, methodological rigor, empirical validations, and ignorance of multiple and non-linear paths to maturity. This PhD thesis focuses on addressing...... these criticisms by incorporating recent developments in configuration theory, in particular application of set-theoretic approaches. The aim is to show the potential of employing a set-theoretic approach for maturity model research and empirically demonstrating equifinal paths to maturity. Specifically...... methodological guidelines consisting of detailed procedures to systematically apply set theoretic approaches for maturity model research and provides demonstrations of it application on three datasets. The thesis is a collection of six research papers that are written in a sequential manner. The first paper...

  1. Commercial Space with Technology Maturation

    Science.gov (United States)

    McCleskey, Carey M.; Rhodes, Russell E.; Robinson, John W.

    2013-01-01

    To provide affordable space transportation we must be capable of using common fixed assets and the infrastructure for multiple purposes simultaneously. The Space Shuttle was operated for thirty years, but was not able to establish an effective continuous improvement program because of the high risk to the crew on every mission. An unmanned capability is needed to provide an acceptable risk to the primary mission. This paper is intended to present a case where a commercial space venture could share the large fixed cost of operating the infrastructure with the government while the government provides new advanced technology that is focused on reduced operating cost to the common launch transportation system. A conceivable commercial space venture could provide educational entertainment for the country's youth that would stimulate their interest in the science, technology, engineering, and mathematics (STEM) through access at entertainment parks or the existing Space Visitor Centers. The paper uses this example to demonstrate how growing public-private space market demand will re-orient space transportation industry priorities in flight and ground system design and technology development, and how the infrastructure is used and shared.

  2. Examining the Evolution of Paid Parental Leave.

    Science.gov (United States)

    Sladek, Carol

    While the United States continues to be the only developed nation without mandated paid maternity leave, U.S. employers are blazing their own trail for new parents. This article defines parental leave, explains what's driving the increased interest in paid parental leave among employers offering it and discusses how paid parental leave can benefit employers and employees alike. Finally, the author discusses why not all employers are offering these benefits as well as considerations for employers contemplating whether paid parental leave is right for them.

  3. 5 CFR 630.1015 - Movement between voluntary leave bank and leave transfer programs.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Movement between voluntary leave bank and leave transfer programs. 630.1015 Section 630.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Bank Program § 630.1015 Movement...

  4. 5 CFR 630.1104 - Donations from a leave bank to an emergency leave transfer program.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Donations from a leave bank to an emergency leave transfer program. 630.1104 Section 630.1104 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Emergency Leave Transfer Program § 630.1104 Donations...

  5. 29 CFR 825.205 - Increments of FMLA leave for intermittent or reduced schedule leave.

    Science.gov (United States)

    2010-07-01

    ... intermittent leave or working a reduced leave schedule to commence or end work mid-way through a shift, such as... per week, but works only 20 hours a week under a reduced leave schedule, the employee's ten hours of... 29 Labor 3 2010-07-01 2010-07-01 false Increments of FMLA leave for intermittent or reduced...

  6. Integrating independent research into science curricula to foster STEM leadership

    Science.gov (United States)

    Queenan, Craig; Calabro, Alyssa; Becker, David

    2013-05-01

    Preparing students for college and future careers is one of the main goals of K-12 education, but current STEM teaching methods do not do enough to interest students and leave them prepared to enter into and succeed in STEM careers. While measures to implement unifying standards for science education across the country are aimed at ensuring that all students are taught the same material at each grade level, a shift in the way science is taught to is needed to complete the redesign of science education. The independent research model described here aligns with the new content standards and focuses on developing the principles of perspective, purpose, resources, collaboration, analysis, and presentation. These principles not only engage students in the classroom, but also leave students prepared to enter into science programs in college and succeed in leadership roles in the STEM workforce.

  7. Development of successive cambia and wood structure in stem of Rivea hypocriteriformis (Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Rajput Kishore S.

    2016-07-01

    Full Text Available This study examined the formation of successive rings of cambia in Rivea hypocriteriformis Choisy (Convolvulaceae. The mature stem is composed of four to five rings of xylem alternating with phloem. Successive cambia originate as smaller and larger segments; union and anastomosing of small cambial segments often leads to the formation of discontinuous rings. In the initial stage of growth, several vascular bundles interconnect to form the first ring of vascular cambium. The cambium remains functional for one complete season and becomes dormant during summer; a new ring of cambium is completed prior to the subsequent monsoon season and sprouting of new leaves. Successive cambia are initiated from the pericyclic parenchyma situated three to four cell layers outside of the protophloem. Functionally, all the successive cambia are bidirectional and produce secondary xylem centripetally and phloem centrifugally. The secondary xylem is diffuse-porous, with indistinct growth rings and consisting of wide fibriform vessels, fibre tracheids, and axial and ray parenchyma cells. The xylem rays are uni- to multiseriate and heterocellular. The multiseriate rays contain lignified marginal ray cells and thin-walled, unlignified central cells. The central ray cells also show accumulations of starch and druses. Discrete strands of intraxylary phloem occur at the periphery of the pith, and additional intraxylary phloem develops from adjacent cells as secondary growth progresses. Earlier-formed phloem shows heavy accumulation of callose, followed by its compaction. The development of successive cambia is correlated with extension growth and with the phenology of the plant.

  8. Hormonal regulation of the growth of leaves and inflorescence stalk in Muscari armeniacum Leichtl.

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2016-04-01

    Full Text Available It is known that chilling of Muscari bulbs is necessary for the growth of the inflorescence stalk and flowering, but not for the growth of leaves. Gibberellic acid (GA accelerated stem growth and flowering in chilled Muscari bulbs. In the present experiment it was shown that in unchilled derooted Muscari bulbs the growth of leaves, but not the growth of the inflorescence stalk, was observed when bulbs were stored in water, GA at a concentration of 50 and 100 mg/L, benzyladenine (BA at a concentration of 25 and 50 mg/L, or a mixture of GA+BA (50+25 mg/L, but abscisic acid (ABA at a concentration of 10 mg/L greatly inhibited the growth of leaves. In chilled derooted Muscari bulbs the growth of leaves and inflorescence stalk was observed when bulbs were stored in water or GA, but BA and GA+BA treatments totally inhibited the growth of the inflorescence stalk without an effect on the growth of leaves. These results clearly showed that the growth of leaves and inflorescence stalk in Muscari bulbs are controlled by plant growth regulators in different ways. ABA totally inhibited the growth of leaves and inflorescence stalk in chilled derooted Muscari bulbs. It was shown that after the excision of the inflorescence bud in cultivated chilled Muscari bulbs, the inflorescence stalk died, but application of indole-3-acetic acid (IAA 0.5% in the place of the removed inflorescence bud induced the growth of the inflorescence stalk. IAA applied under the inflorescence bud inhibited the development of flowers (flower-bud blasting and induced the growth of the inflorescence stalk below the treatment site. These results are discussed with reference to hormonal regulation of stem (stalk growth in tulip, narcissus, hyacinth, and Hippeastrum.

  9. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves.

    Science.gov (United States)

    Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

    2016-03-08

    Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.

  10. Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica.

    Science.gov (United States)

    Oñate, Marta; Munné-Bosch, Sergi

    2009-10-01

    Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, alpha-tocopherol and F(v)/F(m) ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of alpha-tocopherol (up to 2.7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants.

  11. Mechanisms of permanent loss of olfactory receptor neurons induced by the herbicide 2,6-dichlorobenzonitrile: Effects on stem cells and noninvolvement of acute induction of the inflammatory cytokine IL-6

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Fang; Fang, Cheng [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States); Schnittke, Nikolai [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Schwob, James E. [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Ding, Xinxin, E-mail: xding@wadsworth.org [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States)

    2013-11-01

    We explored the mechanisms underlying the differential effects of two olfactory toxicants, the herbicide 2,6-dichlorobenzonitrile (DCBN) and the anti-thyroid drug methimazole (MMZ), on olfactory receptor neuron (ORN) regeneration in mouse olfactory epithelium (OE). DCBN, but not MMZ, induced inflammation-like pathological changes in OE, and DCBN increased interleukin IL-6 levels in nasal-wash fluid to much greater magnitude and duration than did MMZ. At 24 h after DCBN injection, the population of horizontal basal cells (HBCs; reserve, normally quiescent OE stem cells) lining the DMM became severely depleted as some of them detached from the basal lamina, and sloughed into the nasal cavity along with the globose basal cells (GBCs; heterogeneous population of stem and progenitor cells), neurons, and sustentacular cells of the neuroepithelium. In contrast, the layer of HBCs remained intact in MMZ-treated mice, as only the mature elements of the neuroepithelium were shed. Despite the respiratory metaplasia accompanying the greater severity of the DCBN lesion, residual HBCs that survived intoxication were activated by the injury and contributed to the metaplastic respiratory epithelium, as shown by tracing their descendants in a K5CreEr{sup T2}::fl(stop)TdTomato strain of mice in which recombination causes HBCs to express TdTomato in advance of the lesion. But, contrary to published observations with MMZ, the HBCs failed to form ORNs. A role for IL-6 in suppressing ORN regeneration in DCBN-treated mice was rejected by the failure of the anti-inflammatory drug dexamethasone to prevent the subsequent respiratory metaplasia in the DMM, suggesting that other factors lead to HBC neuro-incompetence. - Highlights: • The herbicide dichlobenil (DCBN) can damage olfactory epithelium stem cells. • Another olfactory toxicant, methimazole, leaves the olfactory stem cells intact. • DCBN, but not methimazole, induces a prolonged increase in nasal IL-6 levels. • Dexamethasone

  12. GH3::GUS reflects cell-specific developmental patterns and stress-induced changes in wood anatomy in the poplar stem.

    Science.gov (United States)

    Teichmann, Thomas; Bolu-Arianto, Waode Hamsinah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie; Göbel, Cornelia; Grzeganek, Peter; Feussner, Ivo; Hänsch, Robert; Polle, Andrea

    2008-09-01

    GH3 genes related to the auxin-inducible Glycine max (L.) Merr. GmGH3 gene encode enzymes that conjugate amino acids to auxin. To investigate the role of GH3 enzymes in stress responses and normal wood development, Populus x canescens (Ait.) was transformed with the promoter-reporter construct GH3::GUS containing a GH3 promoter and the 5' UTR from soybean. beta-Glucuronidase (GUS) activity was present in the vascular tissues of leaves and in developing lateral roots and was inducible in silent tissues by external auxin application. A decrease in GUS activity from the stem apex to the bottom corresponded to decreases in auxin concentrations in these tissues. High auxin concentration and high GH3::GUS activity were present in the pith tissue, which may provide storage for auxin compounds. GH3 reporter was active in ray cells, paratracheal parenchyma cells, maturing vessels and in cells surrounding maturing phloem fibers but not in the cambium and immature phloem, despite high auxin concentrations in the latter tissues. However, the GH3 promoter in these tissues became active when the plants were exposed to abiotic stresses, like bending or salinity, causing changes in wood anatomy. We suggest that adjustment of the internal auxin balance in wood in response to environmental cues involves GH3 auxin conjugate synthases.

  13. Stem Cell Transplant

    Science.gov (United States)

    ... Graft-versus-host disease: A potential risk when stem cells come from donors If you receive a transplant ... medications and blood products into your body. Collecting stem cells for transplant If a transplant using your own ...

  14. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... here Home » Glossary Back to top Glossary Adult stem cell Astrocyte Blastocoel Blastocyst Bone marrow stromal cells Bone ...

  15. Plant stem cell niches.

    Science.gov (United States)

    Stahl, Yvonne; Simon, Rüdiger

    2005-01-01

    Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

  16. Game Maturity Model for Health Care.

    Science.gov (United States)

    de Boer, Jan C; Adriani, Paul; van Houwelingen, Jan Willem; Geerts, A

    2016-04-01

    This article introduces the Game Maturity Model for the healthcare industry as an extension to the general Game Maturity Model and describes the usage by two case studies of applied health games. The Game Maturity Model for healthcare provides a practical and value-adding method to assess existing games and to determine strategic considerations for application of applied health games. Our forecast is that within 5 years the use and development of applied games will have a role in our daily lives and the way we organize health care that will be similar to the role social media has today.

  17. Service Quality and Process Maturity Assessment

    Directory of Open Access Journals (Sweden)

    Serek Radomir

    2013-12-01

    Full Text Available This article deals with service quality and the methods for its measurement and improvements to reach the so called service excellence. Besides older methods such as SERVQUAL and SERPERF, there are also shortly described capability maturity models based on which the own methodology is developed and used for process maturity assessment in organizations providing technical services. This method is equally described and accompanied by examples on pictures. The verification of method functionality is explored on finding a correlation between service employee satisfaction and average process maturity in a service organization. The results seem to be quite promising and open an arena for further studies.

  18. Maturity grids as tools for change management

    DEFF Research Database (Denmark)

    Maier, Anja; Moultrie, James; Clarkson, P John

    2011-01-01

    A maturity grid is a change management tool. Levels of maturity are assigned against aspects of an area under study, thus creating a grid. Text descriptions at the resulting intersections describe the typical behaviour exhibited by a firm for each area under study and from the basis...... for the assessment scale. It is a flexible assessment technique that is used by practitioners in industry, consultants and researchers in academia for diagnostic, reflective and improvement purposes. A large number of maturity grids have been proposed to assess a range of capabilities including quality management...

  19. RECRUITMENT FINANCED BY SAVED LEAVE (RSL PROGRAMME)

    CERN Multimedia

    Division du Personnel; Tel. 73903

    1999-01-01

    Transfer to the saved leave account and saved leave bonusStaff members participating in the RSL programme may opt to transfer up to 10 days of unused annual leave or unused compensatory leave into their saved leave account, at the end of the leave year, i.e. 30 September (as set out in the implementation procedure dated 27 August 1997).A leave transfer request form, which you should complete, sign and return, if you wish to use this possibility, has been addressed you. To allow the necessary time for the processing of your request, you should return it without delay.As foreseen in the implementation procedure, an additional day of saved leave will be granted for each full period of 20 days remaining in the saved leave account on 31 December 1999, for any staff member participating in the RSL programme until that date.For part-time staff members participating in the RSL programme, the above-mentioned days of leave (annual, compensatory and saved) are adjusted proportionally to their contractual working week as...

  20. The effect of distal ulnar implant stem material and length on bone strains.

    Science.gov (United States)

    Austman, Rebecca L; Beaton, Brendon J B; Quenneville, Cheryl E; King, Graham J W; Gordon, Karen D; Dunning, Cynthia E

    2007-01-01

    Implant design parameters can greatly affect load transfer from the implant stem to the bone. We have investigated the effect of length or material of distal ulnar implant stems on the surrounding bone strains. Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5-30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm-long finely threaded stem was cemented into the canal. After the cement had cured, the 8-cm stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded stems of interest. The loading protocol was then repeated for stainless steel stems that were 7, 5, and 3 cm in length, as well as for a 5-cm-long titanium alloy (TiAl(6)V(4)) stem. Other stainless steel stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. No stem length tested matched the native strains at all gauge locations. No significant differences were found between any stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium stem than the stainless steel stem for each gauge pair that was positioned on the bone overlying the stem. The 3-cm stem results were closer to the native strains than the 7-cm stem for all loads at gauges locations that were on top of the stem. The results from this study suggest that the optimal stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium stems.

  1. Carbon isotopic composition of legumes with photosynthetic stems from Mediterranean and desert habitats

    International Nuclear Information System (INIS)

    Nilsen, E.T.; Sharifi, M.R.

    1997-01-01

    The carbon isotopic compositions of leaves and stems of woody legumes growing in coastal mediterranean and inland desert sites in California were compared. The overall goal was to determine what factors were most associated with the carbon isotope composition of photosynthetic stems in these habitats. The carbon isotope signature (delta 13C) of photosynthetic stems was less negative than that of leaves on the same plants by an average of 1.51 +/- 0.42 per thousand. The delta 13C of bark (cortical chlorenchyma and epidermis) was more negative than that of wood (vascular tissue and pith) from the same plant for all species studied on all dates. Desert woody legumes had a higher delta 13C (less negative) and a lower intercellular CO2 concentration (Ci) (for both photosynthetic tissues) than that of woody legumes from mediterranean climate sites. Differences in the delta 13C of stems among sites could be entirely accounted for by differences among site air temperatures. Thus, the delta 13C composition of stems did not indicate a difference in whole-plant integrated water use efficiency (WUE) among sites. In contrast, stems on all plants had a lower stem Ci and a higher delta 13C than leaves on the same plant, indicating that photosynthetic stems improve long-term, whole-plant water use efficiency in a diversity of species

  2. Creative Teaching in STEM

    Science.gov (United States)

    Pollard, Vikki; Hains-Wesson, Rachael; Young, Karen

    2018-01-01

    If Science, Technology, Engineering and Mathematics (STEM) disciplines in higher education are to retain students, there needs to be a shift towards teaching in more enriching and interesting ways. Creative teaching needs to become more prominent in STEM. This article presents a study that defines creative teaching in the STEM context and…

  3. Acclimation responses to high light by Guazuma ulmifolia Lam. (Malvaceae) leaves at different stages of development.

    Science.gov (United States)

    Calzavara, A K; Rocha, J S; Lourenço, G; Sanada, K; Medri, C; Bianchini, E; Pimenta, J A; Stolf-Moreira, R; Oliveira, H C

    2017-09-01

    The re-composition of deforested environments requires the prior acclimation of seedlings to full sun in nurseries. Seedlings can overcome excess light either through the acclimation of pre-existing fully expanded leaves or through the development of new leaves that are acclimated to the new light environment. Here, we compared the acclimation capacity of mature (MatL, fully expanded at the time of transfer) and newly expanded (NewL, expanded after the light shift) leaves of Guazuma ulmifolia Lam. (Malvaceae) seedlings to high light. The seedlings were initially grown under shade and then transferred to full sunlight. MatL and NewL were used for chlorophyll fluorescence and gas exchange analyses, pigment extraction and morpho-anatomical measurements. After the transfer of seedlings to full sun, the MatL persisted and acclimated to some extent to the new light condition, since they underwent alterations in some morpho-physiological traits and maintained a functional electron transport chain and positive net photosynthesis rate. However, long-term exposure to high light led to chronic photoinhibition in MatL, which could be related to the limited plasticity of leaf morpho-anatomical attributes. However, the NewL showed a high capacity to use the absorbed energy in photochemistry and dissipate excess energy harmlessly, attributes that were favoured by the high structural plasticity exhibited by these leaves. Both the maintenance of mature, photosynthetically active leaves and the production of new leaves with a high capacity to cope with excess energy were important for acclimation of G. ulmifolia seedlings. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Relations between Polyphenols Content and Antioxidative Activity in Vine Grapes and Leaves

    Czech Academy of Sciences Publication Activity Database

    Balík, J.; Kyseláková, M.; Vrchotová, Naděžda; Tříska, Jan; Kumšta, M.; Veverka, J.; Híc, P.; Totušek, J.; Lefnerová, D.

    2008-01-01

    Roč. 26, special (2008), s. 25-35 ISSN 1212-1800. [Quality of Moravian and Czech Wines and their Future. Lednice, 11.09.2008-12.09.2008] R&D Projects: GA ČR(CZ) GA525/06/1757 Institutional research plan: CEZ:AV0Z60870520 Keywords : vine grapes * vine leaves * stems * piceid * resveratrol * caftaric acid * catechin Subject RIV: GM - Food Processing Impact factor: 0.472, year: 2008

  5. Barley HvPAPhy_a as transgene provides high and stable phytase activities in mature barley straw and in grains.

    Science.gov (United States)

    Holme, Inger Baeksted; Dionisio, Giuseppe; Madsen, Claus Krogh; Brinch-Pedersen, Henrik

    2017-04-01

    The phytase purple acid phosphatase (HvPAPhy_a) expressed during barley seed development was evaluated as transgene for overexpression in barley. The phytase was expressed constitutively driven by the cauliflower mosaic virus 35S-promoter, and the phytase activity was measured in the mature grains, the green leaves and in the dry mature vegetative plant parts left after harvest of the grains. The T 2 -generation of HvPAPhy_a transformed barley showed phytase activity increases up to 19-fold (29 000 phytase units (FTU) per kg in mature grains). Moreover, also in green leaves and mature dry straw, phytase activities were increased significantly by 110-fold (52 000 FTU/kg) and 57-fold (51 000 FTU/kg), respectively. The HvPAPhy_a-transformed barley plants with high phytase activities possess triple potential utilities for the improvement of phosphate bioavailability. First of all, the utilization of the mature grains as feed to increase the release of bio-available phosphate and minerals bound to the phytate of the grains; secondly, the utilization of the powdered straw either directly or phytase extracted hereof as a supplement to high phytate feed or food; and finally, the use of the stubble to be ploughed into the soil for mobilizing phytate-bound phosphate for plant growth. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. 7 CFR 1710.115 - Final maturity.

    Science.gov (United States)

    2010-01-01

    ... Basic Policies § 1710.115 Final maturity. (a) RUS is authorized to make loans and loan guarantees with a... due, in part, to obsolescence. Operating loans to finance working capital required for the initial...

  7. Geospatial Information System Capability Maturity Models

    Science.gov (United States)

    2017-06-01

    To explore how State departments of transportation (DOTs) evaluate geospatial tool applications and services within their own agencies, particularly their experiences using capability maturity models (CMMs) such as the Urban and Regional Information ...

  8. Pristipomoides filamentosus Size at Maturity Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains information used to help determine median size at 50% maturity for the bottomfish species, Pristipomoides filamentosus in the Main Hawaiian...

  9. Paternity leave experiences of NHS doctors.

    Science.gov (United States)

    Gordon, Hannah; Szram, Joanna

    2013-10-01

    This study assesses NHS doctors' experiences of paternity leave and evaluates whether practices have changed since the introduction of additional paternity leave (APL) in April 2011. An anonymised online survey designed to discover experiences and uptake of APL and ordinary paternity leave (OPL) was distributed to all members of the London Deanery Synapse® network. In total, 364 fathers responded. Their seniority ranged from foundation trainees to consultants. Following the formal introduction of OPL in 2003, the number of fathers taking any paternity leave increased (from 50% to 95.6%). The majority of respondents (76.7%) felt well supported by their employer. Since the introduction of APL, 3% of respondents took additional leave. Reasons for the low uptake of APL included the impracticalities of the law, poor awareness and perceived attitudes and implications for training. Problems with OPL included the inadequate provision of cover and difficulties in timing the leave appropriately.

  10. Recent Advances in Intestinal Stem Cells.

    Science.gov (United States)

    McCabe, Laura R; Parameswaran, Narayanan

    2017-09-01

    The intestine is a dynamic organ with rapid stem cell division generating epithelial cells that mature and apoptose in 3-5 days. Rapid turnover maintains the epithelial barrier and homeostasis. Current insights on intestinal stem cells (ISCs) and their regulation are discussed here. The Lgr5+ ISCs maintain intestinal homeostasis by dividing asymmetrically, but also divide symmetrically to extinguish or replace ISCs. Following radiation or mucosal injury, reserve BMI1+ ISCs as well as other crypt cells can de-differentiate into Lgr5+ ISCs. ISC niche cells, including Paneth, immune and myofibroblast cells secrete factors that regulate ISC proliferation. Finally, several studies indicate that the microbiome metabolites regulate ISC growth. ISC cells can be plastic and integrate a complexity of environmental/niche cues to trigger or suppress proliferation as needed.

  11. Mature teratoma of the posterior mediastinum

    Energy Technology Data Exchange (ETDEWEB)

    Kurosaki, Y.; Tanaka, Y.O.; Itai, Y. [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba-shi, Ibaraki-ken 305 (Japan)

    1998-02-01

    The vast majority of germ cell tumors in the thorax arise at or near the thymus. We report a case of a 41-year-old man with mature teratoma of the posterior mediastinum. He was asymptomatic and was incidentally found to have a posterior mediastinal mass. Computed tomography was helpful in suggesting a diagnosis of mature teratoma by demonstrating the presence of fat and calcification. The differential diagnosis included neurogenic tumors, liposarcoma, and extramedullary hematopoiesis. (orig.) With 2 figs., 18 refs.

  12. Mature teratoma of the posterior mediastinum

    International Nuclear Information System (INIS)

    Kurosaki, Y.; Tanaka, Y.O.; Itai, Y.

    1998-01-01

    The vast majority of germ cell tumors in the thorax arise at or near the thymus. We report a case of a 41-year-old man with mature teratoma of the posterior mediastinum. He was asymptomatic and was incidentally found to have a posterior mediastinal mass. Computed tomography was helpful in suggesting a diagnosis of mature teratoma by demonstrating the presence of fat and calcification. The differential diagnosis included neurogenic tumors, liposarcoma, and extramedullary hematopoiesis. (orig.)

  13. Radiation induced early maturing mutants in barley

    International Nuclear Information System (INIS)

    Kumar, R.; Chauhan, S.V.S.; Sharma, R.P.

    1978-01-01

    In M 2 generation, two early maturing plants were screened from a single spike progeny of a plant obtained from 20 kR of gamma-ray irradiation of a six-rowed barley (Hordeum vulgare L. var. Jyoti). Their true breeding nature was confirmed in M 3 generation. These mutants flower and mature 38 and 22 days earlier than those of control. (auth.)

  14. Intra-follicular interactions affecting mammalian oocyte maturation

    NARCIS (Netherlands)

    van Tol, H.T.A.|info:eu-repo/dai/nl/313871817

    2009-01-01

    Nuclear oocyte maturation is defined as reinitiation and progression of the first meiotic division and subsequently formation of the methaphase II (MII) plate. Concomitantly with nuclear maturation, cytoplasmic maturation which is essential for proper fertilization and early embryo development is

  15. Paid Maternity Leave and Breastfeeding Outcomes.

    Science.gov (United States)

    Mirkovic, Kelsey R; Perrine, Cria G; Scanlon, Kelley S

    2016-09-01

    Despite the benefits of breastfeeding, rates in the United States are low. Shorter maternity leave is associated with lower initiation and shorter durations of breastfeeding; however, little is known about how paid maternity leave may influence breastfeeding rates. We used data from the 2006-2010 U.S. National Survey of Family Growth on the most recent birth to employed women who delivered a child within the previous 5 years. Separate multivariable logistic regression models were used to describe the associations between paid leave duration (0, 1-5, 6-11, ≥ 12 weeks, maternity leave not taken) and three outcomes: 1) breastfeeding initiation, 2) 6-month duration, and 3) 6-month duration among initiators. Twenty-eight percent of prenatally employed women received no paid leave. Women who received 12 or more weeks of paid leave were more likely to initiate breastfeeding compared to women with no paid leave (87.3% vs 66.7%, adjusted odds ratio [aOR] 2.83 [95% confidence interval {CI} 1.23-6.48]). Similarly, women with 12 or more weeks of paid leave were more likely to breastfeed at 6 months, compared to women with no paid leave (24.9% vs 50.1%, aOR 2.26 [95% CI 1.20-4.26]). Among women who initiated breastfeeding, having received 12 or more weeks' paid leave increased the odds of breastfeeding for 6 or more months; however, the association was not statistically significant in the adjusted model (aOR 1.81 [95% CI 0.93-3.52]). Employed women who received 12 or more weeks of paid maternity leave were more likely to initiate breastfeeding and be breastfeeding their child at 6 months than those without paid leave. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  16. [New cerebroside from leaves of pineapple].

    Science.gov (United States)

    Wang, Jin-Ping; Wang, Hong-Ying; Du, Li-Jun; Ding, Yi; Xing, Dong-Ming; Wang, Wei

    2007-03-01

    To study the chemical constituents of the leaves of pineapple. Chromatographic methods were used to isolate compounds from the leaves of pineapple and spectral methods were used to identify the structures of the isolated compounds. Compound 1 was isolated from the leaves of pineapple. It was identified as 1-O-beta-D-glucopyranosyl-(2S, 3R, 4E, 11E)-2-[(2(R)-hydroxydocosanoyl) amido]-4, 11-hexadecanediene-1, 3-diol. Compound 1 was a new compound.

  17. New record of Phytophthora root and stem rot of Lavandula angustifolia

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  18. Generation and Characterization of Erythroid Cells from Human Embryonic Stem Cells and Induced Pluripotent Stem Cells: An Overview

    Directory of Open Access Journals (Sweden)

    Kai-Hsin Chang

    2011-01-01

    Full Text Available Because of the imbalance in the supply and demand of red blood cells (RBCs, especially for alloimmunized patients or patients with rare blood phenotypes, extensive research has been done to generate therapeutic quantities of mature RBCs from hematopoietic stem cells of various sources, such as bone marrow, peripheral blood, and cord blood. Since human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs can be maintained indefinitely in vitro, they represent potentially inexhaustible sources of donor-free RBCs. In contrast to other ex vivo stem-cell-derived cellular therapeutics, tumorigenesis is not a concern, as RBCs can be irradiated without marked adverse effects on in vivo function. Here, we provide a comprehensive review of the recent publications relevant to the generation and characterization of hESC- and iPSC-derived erythroid cells and discuss challenges to be met before the eventual realization of clinical usage of these cells.

  19. Mature students' perspectives of studying radiography

    International Nuclear Information System (INIS)

    Williams, M.; Decker, S.

    2009-01-01

    The study set out to explore the experiences of all final year mature students on a diagnostic radiography course, in one United Kingdom University. The aims were to identify any difficulties they may have had and to make recommendations to improve mature students' learning experiences with the hope of lowering attrition rates in this group. A qualitative study involving one-to-one audio recorded interviews was utilised. Analysis of the transcripts of interviews suggested that the group believed that their maturity and previous experiences helped them in the clinical environment and put them in a good position, when asked, to counsel younger students. However for some of the mature students these experiential skills did not extend fully into seeking appropriate support for themselves. The mature students were found to be highly motivated but there was a conflict between balancing clinical and academic aspects of studying as well as balancing studying with home life. The group was found to be unprepared for the volume of academic work and its detrimental effect on family life as they sacrificed other aspects of their lives in order to complete the course. It is recommended that forewarning and forearming prospective mature students be considered by radiography education providers. Setting up and utilising an on-line forum providing a 24/7 peer support environment would aid in coping with academic, clinical or personal problems

  20. Color back projection for fruit maturity evaluation

    Science.gov (United States)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    In general, fruits and vegetables such as tomatoes and dates are harvested before they fully ripen. After harvesting, they continue to ripen and their color changes. Color is a good indicator of fruit maturity. For example, tomatoes change color from dark green to light green and then pink, light red, and dark red. Assessing tomato maturity helps maximize its shelf life. Color is used to determine the length of time the tomatoes can be transported. Medjool dates change color from green to yellow, and the orange, light red and dark red. Assessing date maturity helps determine the length of drying process to help ripen the dates. Color evaluation is an important step in the processing and inventory control of fruits and vegetables that directly affects profitability. This paper presents an efficient color back projection and image processing technique that is designed specifically for real-time maturity evaluation of fruits. This color processing method requires very simple training procedure to obtain the frequencies of colors that appear in each maturity stage. This color statistics is used to back project colors to predefined color indexes. Fruit maturity is then evaluated by analyzing the reprojected color indexes. This method has been implemented and used for commercial production.

  1. Breeding of cocksfoot cultivars with different maturity

    Directory of Open Access Journals (Sweden)

    Babić Snežana

    2017-01-01

    Full Text Available One of the most important criteria in breeding process of perennial grasses is maturity. Cultivars with different maturity play a very important role in utilization of perennial grasses, by providing the ability to create a mixture of different aspects utilization and time. The first grass species in Serbia whose breeding program involved this criterion was cocksfoot (Dactylis glomerata L.. In general cocksfoot is early to medium-early in maturity in comparison with other grasses and legumes, and that is mayor problem since in the optimum phase for cutting, cocksfoot is often earlier then other species in mixtures. As a result of this work, in the previous period, two cultivars of different maturity were released, Kruševačka 24 (K-24 and Kruševačka 25 (K-25. K-24 is medium and K-25 is late in maturity. New material is adapted to local agro-ecological conditions and productive in the same time. In breeding process of both cultivars initial material originated from autochthonous populations collected in eastern and central Serbia. Material from the wild flora is selected based on medium and late maturity which is already adapted and has good productivity. We applied the standard method of phenotypic recurrent selection with the creation of synthetic varieties by polycross.

  2. Nurses' leaving intentions: antecedents and mediating factors.

    Science.gov (United States)

    Takase, Miyuki; Yamashita, Noriko; Oba, Keiko

    2008-05-01

    This paper is a report of a study to investigate how nurses' work values, perceptions of environmental characteristics, and organizational commitment are related to their leaving intentions. Nurse leaving is a serious international problem as it contributes to the nursing shortage that threatens the welfare of society. The characteristics of nurses, the work environment and nurses' feelings towards their jobs (or organizations) have an impact on their leaving intentions. A convenience sample of 849 Registered Nurses was recruited from three public hospitals in the central-west region of Japan during 2006 and 319 completed questionnaires were returned (response rate 39%). Data were analysed using regression analysis. Nurses' work values and their perceptions of their workplace environment interacted to influence leaving intentions. When there was a match between the importance nurses placed on being able to challenge current clinical practices and the number of the actual opportunities to do so, leaving intentions were low. When there was a mismatch, intention to quit the job became stronger. In addition, organizational commitment intervened between nurses' perceptions of the match in clinical challenges and leaving intention. Nurses' leaving intentions, deserve extensive exploration of their causes. Such exploration should include attending to both nurses' needs and organizational characteristics, investigating how the match between them could affect nurses' leaving intention, and exploring factors that intervene between nurses' perceptions of the match and leaving intention.

  3. Automated rose cutting in greenhouses with 3D vision and robotics : analysis of 3D vision techniques for stem detection

    NARCIS (Netherlands)

    Noordam, J.C.; Hemming, J.; Heerde, van C.J.E.; Golbach, F.B.T.F.; Soest, van R.; Wekking, E.

    2005-01-01

    The reduction of labour cost is the major motivation to develop a system for robot harvesting of roses in greenhouses that at least can compete with manual harvesting. Due to overlapping leaves, one of the most complicated tasks in robotic rose cutting is to locate the stem and trace the stem down

  4. Assessment of cortical maturation with prenatal MRI. Part I: normal cortical maturation

    International Nuclear Information System (INIS)

    Fogliarini, Celine; Chaumoitre, Katia; Chapon, Frederique; Levrier, Olivier; Girard, Nadine; Fernandez, Carla; Figarella-Branger, Dominique

    2005-01-01

    Cortical maturation, especially gyral formation, follows a temporospatial schedule and is a good marker of fetal maturation. Although ultrasonography is still the imaging method of choice to evaluate fetal anatomy, MRI has an increasingly important role in the detection of brain abnormalities, especially of cortical development. Knowledge of MRI techniques in utero with the advantages and disadvantages of some sequences is necessary, in order to try to optimize the different magnetic resonance sequences to be able to make an early diagnosis. The different steps of cortical maturation known from histology represent the background necessary for the understanding of maturation in order to be then able to evaluate brain maturation through neuroimaging. Illustrations of the normal cortical maturation are given for each step accessible to MRI for both the cerebral hemispheres and the posterior fossa. (orig.)

  5. Assessment of cortical maturation with prenatal MRI. Part I: normal cortical maturation

    Energy Technology Data Exchange (ETDEWEB)

    Fogliarini, Celine [Faculte Timone, Centre de Resonance Magnetique Biologique et Medicale, Marseille (France); Chaumoitre, Katia [Hopital Nord, Department of Radiology, Marseille (France); Chapon, Frederique; Levrier, Olivier; Girard, Nadine [Hopital Timone, Department of Neuroradiology, Marseille Cedex 5 (France); Fernandez, Carla; Figarella-Branger, Dominique [Hopital Timone, Department of Pathology, Marseille (France)

    2005-08-01

    Cortical maturation, especially gyral formation, follows a temporospatial schedule and is a good marker of fetal maturation. Although ultrasonography is still the imaging method of choice to evaluate fetal anatomy, MRI has an increasingly important role in the detection of brain abnormalities, especially of cortical development. Knowledge of MRI techniques in utero with the advantages and disadvantages of some sequences is necessary, in order to try to optimize the different magnetic resonance sequences to be able to make an early diagnosis. The different steps of cortical maturation known from histology represent the background necessary for the understanding of maturation in order to be then able to evaluate brain maturation through neuroimaging. Illustrations of the normal cortical maturation are given for each step accessible to MRI for both the cerebral hemispheres and the posterior fossa. (orig.)

  6. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  7. Stem Cell Pathology.

    Science.gov (United States)

    Fu, Dah-Jiun; Miller, Andrew D; Southard, Teresa L; Flesken-Nikitin, Andrea; Ellenson, Lora H; Nikitin, Alexander Yu

    2018-01-24

    Rapid advances in stem cell biology and regenerative medicine have opened new opportunities for better understanding disease pathogenesis and the development of new diagnostic, prognostic, and treatment approaches. Many stem cell niches are well defined anatomically, thereby allowing their routine pathological evaluation during disease initiation and progression. Evaluation of the consequences of genetic manipulations in stem cells and investigation of the roles of stem cells in regenerative medicine and pathogenesis of various diseases such as cancer require significant expertise in pathology for accurate interpretation of novel findings. Therefore, there is an urgent need for developing stem cell pathology as a discipline to facilitate stem cell research and regenerative medicine. This review provides examples of anatomically defined niches suitable for evaluation by diagnostic pathologists, describes neoplastic lesions associated with them, and discusses further directions of stem cell pathology.

  8. Study on the doubling effect of colchicine on leaves in vitro of apple seedlings

    International Nuclear Information System (INIS)

    Wang Changquan; Li Yazhi; Cui Decai; Su Huairui

    1997-01-01

    Leaves in vitro of two diploid apple cultivars were treated with different concentrations of colchicine and 2% DMSO solution. Among all treatments, 0.5% of colchicine treating for 4 days showed the best effect with variation frequency of 56.1%. Obvious changes occurred in the morphological and cytological aspects of the induced tetraploidy apple plants. In comparison with normal plants, variant plants showed the following features: the stem became dwarf and thick; node was shorten; the leaves' colour appeared dark green. The stomata cell size was larger than that of diploid plants. The number of the stomata per unit area of the leaves in variant plants distinctly reduced. The chromosome number were determined to be 2n = 2x = 34 for diploid plants and 2n = 4x = 68 for variant plants. The nucleolus number of variant plants increased. By the means of section of paraffin-embedded shoot auspices, 86% of variant plants have been identified as solid tetraploidy

  9. Mind the Gap: Women in STEM Career Breaks

    Directory of Open Access Journals (Sweden)

    Catherine Mavriplis

    2010-03-01

    Full Text Available There are two issues related to women and pathways to STEM careers. Recruitment to the field is one aspect. The second issue is the retention of women in STEM fields. This paper reports on the structured interviews with 14 women who have taken career breaks sometime after receiving their PhD in order to understand the pressures in place to take such breaks, how women remain connected (or not to their field during the break and issues related to re-entering the field after a career break. Suggestions based on the interviews include enhancements for women’s preparation for STEM fields and changes to the STEM culture itself. We suggest the inclusion workshops to detail what they might expect in their career and a provision for networking opportunities. We urge changes in the fee structure for society membership, differences in how resumes are reviewed as well as changes in maternity and child care leave.

  10. Distribution of radionuclides in different parts of a mushroom: Influence of the degree of maturity

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, Antonio [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain)]. E-mail: ymiralle@unex.es; Guillen, Fco. Javier [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain); Salas, Alejandro [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain); Manjon, Jose Luis [Department of Plant Biology, Faculty of Sciences, University of Alcala, 28871 Alcala de Henares, Madrid (Spain)

    2006-04-15

    Mushrooms are known to be bioaccumulators of radionuclides, but little is known about their distribution within the fruiting bodies or the influence of the degree of maturity on uptake. We carried out a series of cultures of the species Pleurotus eryngii under controlled laboratory conditions to analyze these variables. The maximal uptake of {sup 134}Cs and {sup 85}Sr was found to occur in mature fruiting bodies, and with the growth of the mushroom the distribution of radionuclides within the fruiting bodies became inhomogeneous. In particular, there was an exponential increase in the percentage of the total activity of {sup 134}Cs, {sup 85}Sr, and {sup 6}Co in the cap + gills as the fruiting bodies matured, accompanied by a complementary decrease in the stem. Radiocaesium, potassium, calcium, {sup 239+24}Pu, {sup 234,238}U, {sup 228,230,232}Th, and {sup 226}Ra were assayed in the cap, gills, and stem of fruiting bodies of Tricholoma equestre collected in a natural ecosystem and cultured P. eryngii. Potassium and radiocaesium were mainly located in the cap + gills, and {sup 226}Ra in the gills. There was a disequilibrium between {sup 230,232}Th and {sup 228}Th in the different parts of the fungi, probably due to uptake of {sup 228}Ra and subsequent decay to {sup 228}Th. Finally, the distribution pattern of{sup 239+24}Pu, {sup 234,238}U, and {sup 230,232}Th seemed to be species dependent.

  11. Structural phenotyping of stem cell-derived cardiomyocytes.

    Science.gov (United States)

    Pasqualini, Francesco Silvio; Sheehy, Sean Paul; Agarwal, Ashutosh; Aratyn-Schaus, Yvonne; Parker, Kevin Kit

    2015-03-10

    Structural phenotyping based on classical image feature detection has been adopted to elucidate the molecular mechanisms behind genetically or pharmacologically induced changes in cell morphology. Here, we developed a set of 11 metrics to capture the increasing sarcomere organization that occurs intracellularly during striated muscle cell development. To test our metrics, we analyzed the localization of the contractile protein α-actinin in a variety of primary and stem-cell derived cardiomyocytes. Further, we combined these metrics with data mining algorithms to unbiasedly score the phenotypic maturity of human-induced pluripotent stem cell-derived cardiomyocytes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Tinospora cordifolia stem supplementation in diabetic dyslipidemia: an open labelled randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kuhu Roy

    2015-08-01

    Full Text Available Background: Medicinal plants are powerful health promoting nutritional agents. Among the vast library of medicinal plants Tinospora cordifolia (Willd. has been meagrely explored. It belongs to the family Menispermaceae and is a rich source of alkaloid and terpenes. It has hepatoprotective, antioxidant, immunostimulatory, hyperlipidemic, anticancer and antidiabetic properties. The stem contains berberine, palmatine, tembetarine, magnoflorine, tinosporin, tinocordifolin. The stem starch is highly nutritive and digestive. In modern medicine it is called the magical rejuvenating herb owing to its properties to cure many diseases. The stem contains higher alkaloid content than the leaves because of which it is approved for medicinal usage. With a host of phytochemical properties present in the stem, it may hold potential to manage dyslipidemia and dysglycemia, which otherwise has been proven only in pre-clinical studies. Objective: To study the impact of tinospora cordifolia stem supplementation on the glycemic and lipemic profile of subjects with diabetic dyslipidemia. Methods: Type 2 diabetics with dyslipidemia on oral hypoglycemic agents were enrolled. Baseline data on medical history, family history of lifestyle diseases, duration of diabetes diagnosis, drug profile, anthropometric data, dietary data and physical activity data was obtained along with a fasting blood sample for estimating high sensitivity C reactive protein (hs-CRP, hepatic, renal, lipid profile and glycated hemoglobin. The participants were randomized into either of the two groups; intervention group (n=29 received 250mg of encapsulated mature stem of tinospora cordifolia pre meal twice a day along with prescribed dyslipidemic agent and control group (n=30 only on dyslipidemic agents for a period of 60 days. After 60 days all the parameters were re-assessed to analyse the impact of the intervention. Results: Majority of the subjects in both the arms were in the 50-60 years age

  13. Morfoanatomia de folha e caule de Genipa americana L., Rubiaceae Leaf and stem morpho-anatomy of Genipa americana L., Rubiaceae

    Directory of Open Access Journals (Sweden)

    Marianna Erbano

    2010-12-01

    Full Text Available Genipa americana L., conhecida como jenipapo, é uma Rubiaceae nativa do Brasil e as suas folhas são utilizadas pela população como antidiarreico e febrífugo, e o caule como anti-hemorrágico, contra luxações e contusões. Com o objetivo de caracterizar macro e microscopicamente folhas adultas e caules jovens para o controle de qualidade farmacognóstico, essa planta medicinal foi analisada segundo a metodologia clássica de morfoanatomia vegetal. Genipa americana apresenta folhas simples, opostas, de formato obovado a oblanceolado e pecíolos curtos. A epiderme foliar é uniestratificada e revestida por cutícula delgada e levemente estriada. Os estômatos são paracíticos e restritos à superfície abaxial. Há tricomas tectores uni e pluricelulares predominantemente na superfície abaxial. O mesofilo é dorsiventral. Em secção transversal, a nervura central é plano-convexa e o pecíolo é circular, ambos apresentando um feixe vascular colateral em disposição cilíndrica e outros menores. O caule possui felogênio localizado nas camadas subepidérmicas, colênquima anelar e um cilindro floemático externo ao de xilema, sendo ambos percorridos por raios parenquimáticos estreitos. Ocorrem idioblastos contendo compostos fenólicos, areia cristalina e drusas de oxalato de cálcio na folha e no caule.Genipa americana L., known as jenipapo, is a Rubiaceae species native to Brazil. Its leaves are used by the population as anti-diarrheic and febrifuge, and its stem as anti-hemorrhagic and for trauma injuries. Aiming to identify macro and microscopically mature leaves and young stems for the pharmacognostic quality control, this medicinal plant was investigated according to standard morpho-anatomical techniques. The leaves are simple, opposite, obovate-oblanceolate, presenting short petiole. The epidermis is uniseriate and coated with thin and slightly striate cuticle. The stomata are paracytic and restricted to the abaxial surface. It

  14. Are stem nectaries common in Gentianaceae Juss.?

    Directory of Open Access Journals (Sweden)

    Valdnéa Casagrande Dalvi

    Full Text Available ABSTRACT Extrafloral nectaries (EFNs are specialized structures that produce and release nectar and are located on leaves, cotyledons and, more seldomly, stems. Peculiar leaf nectaries have been described for thirty-three Neotropical species of Gentianaceae, while stem nectaries have been reported for only nine. The aim of this study was to verify the occurrence of stem EFNs within Gentianaceae and investigate the existence of a correlation between their occurrence and the geographical distribution of species. Samples of internodal regions from field and herbarium specimens were submitted to standard light microscopy techniques. Data regarding the geographical distribution of species were acquired from herbarium specimens and the literature. A total of 37 species were investigated, representing 25 genera distributed among five tribes. Nectaries, composed of modified epidermal cells, were observed in 16 species restricted to the Neotropical tribes Helieae, Saccifolieae, Potalieae and Coutoubeinae; exceptions were Cicendia quadrangularis and Zygostigma australe, which both occur in the Neotropics but do not possess EFNs. These results demonstrate that stem EFNs are common among Neotropical taxa of Gentianaceae, and are typically absent from taxa in temperate regions.

  15. Generation of eggs from mouse embryonic stem cells and induced pluripotent stem cells.

    Science.gov (United States)

    Hayashi, Katsuhiko; Saitou, Mitinori

    2013-08-01

    Oogenesis is an integrated process through which an egg acquires the potential for totipotency, a fundamental condition for creating new individuals. Reconstitution of oogenesis in a culture that generates eggs with proper function from pluripotent stem cells (PSCs) is therefore one of the key goals in basic biology as well as in reproductive medicine. Here we describe a stepwise protocol for the generation of eggs from mouse PSCs, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs are first induced into primordial germ cell-like cells (PGCLCs) that are in turn aggregated with somatic cells of female embryonic gonads, the precursors for adult ovaries. Induction of PGCLCs followed by aggregation with the somatic cells takes up to 8 d. The aggregations are then transplanted under the ovarian bursa, in which PGCLCs grow into germinal vesicle (GV) oocytes in ∼1 month. The PGCLC-derived GV oocytes can be matured into eggs in 1 d by in vitro maturation (IVM), and they can be fertilized with spermatozoa by in vitro fertilization (IVF) to obtain healthy and fertile offspring. This method provides an initial step toward reconstitution of the entire process of oogenesis in vitro.

  16. Translocation of 11C from leaves of Helianthus: preliminary results

    International Nuclear Information System (INIS)

    Fensom, D.S.; Aikman, D.; Scobie, J.; Drinkwater, A.; Ledingham, K.W.O.

    1977-01-01

    11 C fed to leaves as 11 CO 2 was used to study the dynamics of short-term translocation of photosynthate in Helianthus. As in 14 C studies small amounts of tracer were often detected in the stem close to the fed leaf in th first 5 min, followed by a larger mass flow after 15 min. The speed of mass flow of tracer movement was calculated to be 60 to 400 cm.h -1 depending on the method of calculation. There was no evidence in the premass flow for discrete spots along the stem or petiole where tracer accumulated. Neither was there firm evidence for pulses of tracer moving steadily forward, but there were point fluctuations of greater variability than would be expected by chance alone, which suggest the possibility of aberrations of movement superimposed on the mass flow. Details of these aberrations could not be assessed with certainty from these preliminary experiments owing to the rather low tracer activity. The translocation profiles were sensitive to the prior light conditioning of the plant and above all to chilling. In Helianthus the latter produced temporary restrictions in translocation which lasted for some 10-12 min. (author)

  17. Cytotoxic Constituents from the Leaves of Zanthoxylum schinifolium

    International Nuclear Information System (INIS)

    Fang, Zhe; Min, Byung Sun; Kim, Ae Kyong; Woo, Mi Hee; Jun, Do Youn; Kim, Young Ho

    2010-01-01

    The roots, stems, pericarps, and seeds of Z. schinifolium were each extracted with MeOH, and the leaves were extracted with 80% MeOH and concentrated. These extracts were examined on MTT for cytotoxicity against Jurkat T cell clone E6.1. The results showed that the leaves extract had the strongest MTT cytotoxicity. The MeOH extract of Z. schinifolium leaves was subsequently fractionated into four parts: methylene chloride, ethyl acetate, n-butanol and water. These fractions were examined on MTT for cytotoxicity. The results showed that the methylene chloride fraction exhibited the strongest MTT cytotoxicity. Chromatographic separation of the methylene chloride and butanol fractions had yielded a quinolin (1), three phenylpropanoids (2, 3, 12), four coumarins (4 ∼ 7), three triterpenoids (8 ∼ 10), an alkaloid (11), an alcohol glucoside (13) and three monoterpene glucosides (14, 15, 16). One of these compounds were identified as new threo-6-amino-5-hydroxy-5-methyl-1,3-oxazinan-4-one (11) together with fifteen known, 3-heptyl-2-methylisoquinolin-1(2H)-one (1), integrifoliodiol (2), cuspidiol (3), bergapten (4), aurapten (5), 8-hydroxy-7-methoxy-chromen-2-one (6), 6,7-dimethoxy-2H-naphthalen-1-one (7), lupeol (8), lupeone (9), β-sitosterol (10), syringin (12), 2-propyl alchol β-D-glucopyranoside (13), vomifoliol-9-O-β-D-glucopyranoside (14), betulalbuside A (15) and cnidioside C (16) on the basis of spectroscopic and chemical evidences. All of the compounds were isolated for the first time from this plant except 5 and 7. In the MTT cytotoxicity assay against Jurkat T cell clone E6.1, IC 50 values of cuspidiol (3) and auraptene (5) were obtained at 7.3 μg/mL and 16.5 μg/mL, respectively

  18. Cytotoxic Constituents from the Leaves of Zanthoxylum schinifolium

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhe; Min, Byung Sun; Kim, Ae Kyong; Woo, Mi Hee [Catholic Univ. of Daegu, Gyeongsan (Korea, Republic of); Jun, Do Youn; Kim, Young Ho [Kyungpook National Univ., Daegu (Korea, Republic of)

    2010-04-15

    The roots, stems, pericarps, and seeds of Z. schinifolium were each extracted with MeOH, and the leaves were extracted with 80% MeOH and concentrated. These extracts were examined on MTT for cytotoxicity against Jurkat T cell clone E6.1. The results showed that the leaves extract had the strongest MTT cytotoxicity. The MeOH extract of Z. schinifolium leaves was subsequently fractionated into four parts: methylene chloride, ethyl acetate, n-butanol and water. These fractions were examined on MTT for cytotoxicity. The results showed that the methylene chloride fraction exhibited the strongest MTT cytotoxicity. Chromatographic separation of the methylene chloride and butanol fractions had yielded a quinolin (1), three phenylpropanoids (2, 3, 12), four coumarins (4 ∼ 7), three triterpenoids (8 ∼ 10), an alkaloid (11), an alcohol glucoside (13) and three monoterpene glucosides (14, 15, 16). One of these compounds were identified as new threo-6-amino-5-hydroxy-5-methyl-1,3-oxazinan-4-one (11) together with fifteen known, 3-heptyl-2-methylisoquinolin-1(2H)-one (1), integrifoliodiol (2), cuspidiol (3), bergapten (4), aurapten (5), 8-hydroxy-7-methoxy-chromen-2-one (6), 6,7-dimethoxy-2H-naphthalen-1-one (7), lupeol (8), lupeone (9), β-sitosterol (10), syringin (12), 2-propyl alchol β-D-glucopyranoside (13), vomifoliol-9-O-β-D-glucopyranoside (14), betulalbuside A (15) and cnidioside C (16) on the basis of spectroscopic and chemical evidences. All of the compounds were isolated for the first time from this plant except 5 and 7. In the MTT cytotoxicity assay against Jurkat T cell clone E6.1, IC{sub 50} values of cuspidiol (3) and auraptene (5) were obtained at 7.3 μg/mL and 16.5 μg/mL, respectively.

  19. Pharmacognostical studies of leaves of Combretum albidum G. Don

    Directory of Open Access Journals (Sweden)

    Ashish S Zalke

    2013-01-01

    Full Text Available Background: Combretum albidum Don belonging to family Combretaceae is an unexplored medicinal plant in the Indian medicinal system. According to ethnobotanical information, the leaves are used in the treatment of peptic ulcer and its fruits are used in diarrhoea and dysentery. Stem bark is used in the treatment of jaundice and skin diseases. The problem encountered in standardisation of this medicinal plant is its identification by source. Materials and Methods: The pharmacognostical studies were carried out in terms of organoleptic, macroscopic, microscopic, physicochemical, florescence and phytochemical analysis. Physicochemical parameters such as total ash, moisture content and extractive values are determined by World Health Organization guidelines. The microscopic features of leaf components are observed with Nikon lab photo device with microscopic units. Results: Macroscopically, the leaves are simple, obovate in shape, acuminate apex, entire margin and smooth surface. Microscopically, the leaves showed a large vascular strand that consists of thick walled xylem elements mixed with xylem fibres and phloem which is present in a thin layer along inner and outer portions of xylem. External to the xylem occur a thin line of sclerenchyma. Powder microscopy revealed glandular trichomes in the adaxial epidermal peelings also shows the non-glandular trichomes fairly common in powder and epidermis with anisocytic stomata. Vessels elements are narrow, long, cylindrical and dense multi-seriate bordered pits. Xylem fibres are thin and long, with thick walls, which are lignified. Preliminary phytochemical screening showed the presence of carbohydrate, glycoside, saponin, flavonoid, phytosterols and phenolic compounds. Conclusions: The results of the study can serve as a valuable source of pharmacognostic information as suitable standards for identification of this plant material in future investigations and applications.

  20. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Multimedia

    DIVISION HR

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programs) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave. They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave a...

  1. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Document Server

    HR Division

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programmes) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave.They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system 1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave...

  2. Antioxidant activity of Arbutus unedo leaves.

    Science.gov (United States)

    Pabuçcuoğlu, A; Kivçak, B; Baş, M; Mert, T

    2003-09-01

    The ethanol and methanol extracts of Arbutus unedo leaves were screened for antioxidant activity. The antioxidant activity was determined by an improved assay based on the decolorization of the radical monocation of [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS). The ethanol and methanol extract of A. unedo leaves displayed potent antioxidant activity.

  3. Grass leaves as potential hominin dietary resources.

    Science.gov (United States)

    Paine, Oliver C C; Koppa, Abigale; Henry, Amanda G; Leichliter, Jennifer N; Codron, Daryl; Codron, Jacqueline; Lambert, Joanna E; Sponheimer, Matt

    2018-04-01

    Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C 4 component in the diets of most taxa, and grass leaves are the single most abundant C 4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of grass leaves with the plants growing alongside them in African savanna habitats. We also compare grass leaves to the leaves consumed by other hominoids and demonstrate that many, though by no means all, compare favorably with the nutritional and mechanical properties of known primate foods. Our data reveal that grass leaves exhibit tremendous variation and suggest that future reconstructions of hominin dietary ecology take a more nuanced approach when considering grass leaves as a potential hominin dietary resource. Copyright © 2017. Published by Elsevier Ltd.

  4. When and Why Dropouts Leave High School

    Science.gov (United States)

    Stearns, Elizabeth; Glennie, Elizabeth J.

    2006-01-01

    Teens may leave school because of academic failure, disciplinary problems, or employment opportunities. In this article, the authors test whether the reasons dropouts leave school differ by grade level and age. We compare dropout rates and reasons across grade levels and ages for all high school students, ethnic groups, and gender groups. Across…

  5. Effects of phyllotaxy on biomechanical properties of stems of Cercis occidentalis (Fabaceae).

    Science.gov (United States)

    Caringella, Marissa A; Bergman, Brett A; Stanfield, Ryan C; Ewers, Madeleine M; Bobich, Edward G; Ewers, Frank W

    2014-01-01

    Phyllotaxy, the arrangement of leaves on a stem, may impact the mechanical properties of woody stems several years after the leaves have been shed. We explored mechanical properties of a plant with alternate distichous phyllotaxy, with a row of leaves produced on each side of the stem, to determine whether the nodes behave as spring-like joints. Flexural stiffness of 1 cm diameter woody stems was measured in four directions with an Instron mechanical testing system; the xylem of the stems was then cut into node (former leaf junction) and nonnode segments for measurement of xylem density. Stems had 20% greater flexural stiffness in the plane perpendicular to the original leaf placement than in the parallel plane. The xylem in the node region was more flexible, but it had significantly greater tissue density than adjacent regions, contradicting the usual correlation between wood density and stiffness. Nodes can behave as spring-like joints in woody plants. For plagiotropic shoots, distichous phyllotaxy results in stems that resist up-and-down bending more than lateral back-and-forth movement. Thus, they may more effectively absorb applied loads from fruits, animals, wind, rain, and snow and resist stresses due to gravity without cracking and breaking. Under windy conditions, nodes may improve damping by absorbing vibrational energy and thus reducing oscillation damage. The effect of plant nodes also has biomimetic design implications for architects and material engineers.

  6. Phenylpropanoid biosynthesis in leaves and glandular trichomes of basil (Ocimum basilicum L.).

    Science.gov (United States)

    Deschamps, Cícero; Simon, James E

    2010-01-01

    Basil (Ocimum basilicum L.) essential oil phenylpropenes are synthesized and accumulate in peltate glandular trichomes and their content and composition depend on plant developmental stage. Studies on gene expression and enzymatic activity indicate that the phenylpropene biosynthetic genes are developmentally regulated. In this study, the methylchavicol accumulation in basil leaves and the enzyme activities and gene expression of both chavicol O-methyltransferase (CVOMT) and eugenol O-methyltransferase (EOMT) were investigated in all leaves at four plant developmental stages. Methylchavicol accumulation decreased over time as leaves matured. There was a significant correlation between methylchavicol accumulation and CVOMT (r(2) = 0.88) enzyme activity, suggesting that the levels of biosynthetic enzymes control the essential oil content. CVOMT and EOMT transcript expression levels, which decreased with leaf age, followed the same pattern in both whole leaves and isolated glandular trichomes, providing evidence that CVOMT transcript levels are developmentally regulated in basil glandular trichomes themselves and that differences in CVOMT expression observed in whole leaves are not solely the result of differences in glandular trichome density.

  7. [Beneficial effect of maternity leave on delivery].

    Science.gov (United States)

    Xu, Qian; Séguin, Louise; Goulet, Lise

    2002-01-01

    To identify the contribution of the duration of the prenatal maternity leave on term delivery. Characteristics of the prenatal maternity leave and delivery among 363 working women who had delivered a full-term infant at 1 of 4 hospitals in Montreal during 1996 were studied. The presence of an intervention or complication during delivery was observed in 68.9% of the participants. The average duration of the prenatal maternity leave was about 8 weeks (SD = 7). The adjusted risk of a difficult delivery decreased significantly with the duration of the prenatal maternity leave (OR = 0.96; 95% CI: 0.93-0.99). The duration of the maternity leave before delivery is associated with an easier term delivery for working women.

  8. Maturity Model for Advancing Smart Grid Interoperability

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Mark; Widergren, Steven E.; Mater, J.; Montgomery, Austin

    2013-10-28

    Abstract—Interoperability is about the properties of devices and systems to connect and work properly. Advancing interoperability eases integration and maintenance of the resulting interconnection. This leads to faster integration, lower labor and component costs, predictability of projects and the resulting performance, and evolutionary paths for upgrade. When specifications are shared and standardized, competition and novel solutions can bring new value streams to the community of stakeholders involved. Advancing interoperability involves reaching agreement for how things join at their interfaces. The quality of the agreements and the alignment of parties involved in the agreement present challenges that are best met with process improvement techniques. The GridWise® Architecture Council (GWAC) sponsored by the United States Department of Energy is supporting an effort to use concepts from capability maturity models used in the software industry to advance interoperability of smart grid technology. An interoperability maturity model has been drafted and experience is being gained through trials on various types of projects and community efforts. This paper describes the value and objectives of maturity models, the nature of the interoperability maturity model and how it compares with other maturity models, and experiences gained with its use.

  9. Maturity acceleration of Italian dried sausage by Staphylococcus carnosus - Relationship between maturity and flavor compounds

    DEFF Research Database (Denmark)

    Stahnke, Louise Heller; Holck, A.; Jensen, Anni

    2002-01-01

    . Sausages with S. carnosus 833 matured more than 2 wk faster than control sausages. Maturity correlated significantly with higher amounts of branched-chain aldehydes and alcohols and both branched- and straight-chain methyl ketones-compounds arising from the breakdown of the amino acids leucine, isoleucine...

  10. IT Governance Maturity: Developing a Maturity Model Using the Delphi Method

    NARCIS (Netherlands)

    Smits, Daniël; van Hillegersberg, Jos

    2015-01-01

    To advance in maturity, organizations should pay attention to both the hard and soft sides of IT governance (ITG). The hard side is related to processes and structure, the soft side to social aspects like behavior and organizational culture. This paper describes a study to develop an ITG maturity

  11. Global Collaborative STEM Education

    Science.gov (United States)

    Meabh Kelly, Susan; Smith, Walter

    2016-04-01

    Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

  12. Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus.

    Directory of Open Access Journals (Sweden)

    Jie Dong

    Full Text Available After a tightly regulated developmental program in the thymus, "mature" single positive (SP thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4(+ pre-RTEs, a population of CD4(+ SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4(+ pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs' better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4(+ pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4(+ pre-RTEs is independent of MHC class II and Aire molecules.

  13. [Maturation diagnosis in full term hypotrophic fetuses].

    Science.gov (United States)

    Scharnke, H D; Gartzke, J; Fleischer, G; Isbruch, E

    1977-01-01

    Foam-Test by Clements is a valuable method for determining the foetus maturity of lungs. We introduce this test along with other parameters for the maturity-diagnosis since one year. In 15% result, the Foam-Test was not applicable because of blood, or meconic amniotic fluid, other wise wrong negative and in 0% wrong positive results. By unmatured child, there was doubtable results with Foam-Test. Since it is important to determine the early delivery of unmatured children, particularly the case of foetus maturity of lungs must be exact, we therefore decided to use the Lecithin/Sphingomyelinquotients in some cases. The results of Lecithin/Sphingomyelinquotient in unmatured children are almost with the approximated date under two. From this, one must deduce from these children, that the intrauterine unmatured lungs lately took place.

  14. Capability maturity models for offshore organisational management.

    Science.gov (United States)

    Strutt, J E; Sharp, J V; Terry, E; Miles, R

    2006-12-01

    The goal setting regime imposed by the UK safety regulator has important implications for an organisation's ability to manage health and safety related risks. Existing approaches to safety assurance based on risk analysis and formal safety assessments are increasingly considered unlikely to create the step change improvement in safety to which the offshore industry aspires and alternative approaches are being considered. One approach, which addresses the important issue of organisational behaviour and which can be applied at a very early stage of design, is the capability maturity model (CMM). The paper describes the development of a design safety capability maturity model, outlining the key processes considered necessary to safety achievement, definition of maturity levels and scoring methods. The paper discusses how CMM is related to regulatory mechanisms and risk based decision making together with the potential of CMM to environmental risk management.

  15. Mature Oocyte Cryopreservation for Fertility Preservation.

    Science.gov (United States)

    Liang, Tina; Motan, Tarek

    2016-01-01

    In recent decades, advances in cancer treatment have led to a dramatic improvement in long term survival. This has led to an increasing focus on quality of life after surviving cancer treatment, with fertility being an important aspect. Given the known reproductive risks of cancer therapies, there has been a growing interest in the field of fertility preservation (also referred to as oncofertility). Mature oocyte cryopreservation is no longer considered experimental and has become a realistic option for reproductive aged women prior to undergoing cancer treatment. Additionally, as cryopreservation techniques improve, mature oocyte cryopreservation is increasing being marketed to healthy women without cancer wishing to delay child bearing, also termed "social egg freezing". This chapter provides a review of the current technology, use, and outcomes of mature oocyte cryopreservation. It also outlines the ethical debate surrounding social egg freezing and directions for future research in female fertility preservation.

  16. Genetic transformation of mature citrus plants.

    Science.gov (United States)

    Cervera, Magdalena; Juárez, José; Navarro, Luis; Peña, Leandro

    2005-01-01

    Most woody fruit species have long juvenile periods that drastically prolong the time required to analyze mature traits. Evaluation of characteristics related to fruits is a requisite to release any new variety into the market. Because of a decline in regenerative and transformation potential, genetic transformation procedures usually employ juvenile material as the source of plant tissue, therefore resulting in the production of juvenile plants. Direct transformation of mature material could ensure the production of adult transgenic plants, bypassing in this way the juvenile phase. Invigoration of the source adult material, establishment of adequate transformation and regeneration conditions, and acceleration of plant development through grafting allowed us to produce transgenic mature sweet orange trees flowering and bearing fruits in a short time period.

  17. Minoritized Students In STEM Pathways at Community Colleges

    Science.gov (United States)

    Babcock, Michael Jason

    Community colleges are a prominent academic pathway for future scientists, engineers, and mathematicians, and serve as a gateway to higher education for traditionally marginalized student populations. Because of this, community colleges are uniquely positioned to combat the underrepresentation of African American, Latino/a, Native American, and Pacific Islander students in STEM. Research on students of color in STEM, however, has traditionally focused on K-12 schools and four-year colleges and universities, leaving a gap in our understanding about the role of community colleges in shaping student intentions to pursue STEM careers. To address that gap, this study examined students as they pursued a degree in STEM at a community college, for the purposes of contributing to our understandings of students of color in these environments. Utilizing science identity framing and longitudinal multi-case study methods, this study followed thirteen students as they navigated the community college and made decisions regarding their pursuit of a future in STEM fields. Specifically, this study illuminates the racialized nature of STEM at a community college, student thinking around choices to opt into or out of STEM, and the decision-making around choices to persist. Insight into the social and contextual factors underlying students' persistence demonstrates that students of color (especially women of color) do encounter hostile experiences within STEM contexts at community colleges, but how they respond to those hostilities influences persistence. Students who attribute hostilities such as micro-aggressions to the biases of others are more likely to persist. Students who do not attribute those hostilities to others are more likely to assume their experiences are attributable to the fact they do not belong in STEM. The findings establish the importance of recognizing and acknowledging the racialized and gendered nature of STEM, both in academic settings and at home, for those

  18. Total phenols and antioxidant activities of leaf and stem extracts from coriander, mint and parsley grown in Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Juhaimi, F.; Ghafoorr, K.

    2011-01-01

    Leaves and stems of three different herbs from two different families were used to extract phenolic compounds and the bioactivity of the extracts was evaluated by using 1, 1-diphenyl-2-picrylhydrazyl or DPPH scavenging ability or their antioxidant activities. Extract from leaves of mint, which belongs to Lamiaceae family contained 1.24 mgGAE/100 mL of total phenolic compounds and 34.21% antioxidant activity which were significantly higher than those in extracts from coriander and parsley, both of which belong to Apiaceae family. Extracts of leaves from these herbs showed more quantity of total phenols and higher antioxidant activities than extracts from stem parts, however both leaves and stems of these three herbs grown in Saudi Arabia contained good quantities of total phenols (>1.02 mgGAE/100 mL) and showed more than 18.3% free radical scavenging activity. (author)

  19. Bioenergetic Changes during Differentiation of Human Embryonic Stem Cells along the Hepatic Lineage

    DEFF Research Database (Denmark)

    Hopkinson, Branden M; Madsen, Claus Desler; Kalisz, Mark

    2017-01-01

    Mitochondrial dysfunction has been demonstrated to result in premature aging due to its effects on stem cells. Nevertheless, a full understanding of the role of mitochondrial bioenergetics through differentiation is still lacking. Here we show the bioenergetics profile of human stem cells...... of embryonic origin differentiating along the hepatic lineage. Our study reveals especially the transition between hepatic specification and hepatic maturation as dependent on mitochondrial respiration and demonstrates that even though differentiating cells are primarily dependent on glycolysis until induction...

  20. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....