Bioconversion of Agave tequilana fructans by exo-inulinases from indigenous Aspergillus niger CH-A-2010 enhances ethanol production from raw Agave tequilana juice.

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Huitrón, Carlos; Pérez, Rosalba; Gutiérrez, Luís; Lappe, Patricia; Petrosyan, Pavel; Villegas, Jesús; Aguilar, Cecilia; Rocha-Zavaleta, Leticia; Blancas, Abel

2013-01-01

Agave tequilana fructans are the source of fermentable sugars for the production of tequila. Fructans are processed by acid hydrolysis or by cooking in ovens at high temperature. Enzymatic hydrolysis is considered an alternative for the bioconversion of fructans. We previously described the isolation of Aspergillus niger CH-A-2010, an indigenous strain that produces extracellular inulinases. Here we evaluated the potential application of A. niger CH-A-2010 inulinases for the bioconversion of A. tequilana fructans, and its impact on the production of ethanol. Inulinases were analyzed by Western blotting and thin layer chromatography. Optimal pH and temperature conditions for inulinase activity were determined. The efficiency of A. niger CH-A-2010 inulinases was compared with commercial enzymes and with acid hydrolysis. The hydrolysates obtained were subsequently fermented by Saccharomyces cerevisiae to determine the efficiency of ethanol production. Results indicate that A. niger CH-A-2010 predominantly produces an exo-inulinase activity. Optimal inulinase activity occurred at pH 5.0 and 50 °C. Hydrolysis of raw agave juice by CH-A-2010 inulinases yielded 33.5 g/l reducing sugars, compared with 27.3 g/l by Fructozyme(®) (Novozymes Corp, Bagsværd, Denmark) and 29.4 g/l by acid hydrolysis. After fermentation of hydrolysates, we observed that the conversion efficiency of sugars into ethanol was 97.5 % of the theoretical ethanol yield for enzymatically degraded agave juice, compared to 83.8 % for acid-hydrolyzed juice. These observations indicate that fructans from raw Agave tequilana juice can be efficiently hydrolyzed by using A. niger CH-A-2010 inulinases, and that this procedure impacts positively on the production of ethanol.

Nuclear genome size analysis of Agave tequilana Weber

Czech Academy of Sciences Publication Activity Database

Palomino, G.; Doležel, Jaroslav; Méndez, I.; Rubluo, A.

2003-01-01

Roč. 56, č. 1 (2003), s. 37-46 ISSN 0008-7114 Grant - others:Itálie(IT) Z5038910 Institutional research plan: CEZ:AV0Z5038910 Keywords : Flow cytometry * nuclear genome size * Agave tequilana Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.337, year: 2003

Polymorphism and methylation patterns in Agave tequilana Weber var. 'Azul' plants propagated asexually by three different methods.

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Díaz-Martínez, Miriam; Nava-Cedillo, Alejandro; Guzmán-López, José Alfredo; Escobar-Guzmán, Rocío; Simpson, June

2012-04-01

Genetic variation in three forms of asexually propagated Agave tequilana Weber var. 'Azul' plants namely offsets, bulbils and in vitro cultured individuals was studied by AFLP analysis. Low levels of variation were observed between mother plants and offsets and a higher level between mother plant and bulbils. Families obtained from commercial plantations showed lower levels of variation in comparison to families grown as ornamentals. No variation was observed between the original explant and four generations of in vitro cultured plants. Epigenetic variation was also studied by analyzing changes in methylation patterns between mother plants and offspring in each form of asexual reproduction. Offsets and bulbils showed an overall decrease in methylation whereas in vitro cultured plants showed patterns specific to each generation: Generations 1 and 4 showed overall demethylation whereas Generations 2 and 3 showed increased methylation. Analysis of ESTs associated with transposable elements revealed higher proportions of ESTs from Ty1-copia-like, Gypsy and CACTA transposable elements in cDNA libraries obtained from pluripotent tissue suggesting a possible correlation between methylation patterns, expression of transposable element associated genes and somaclonal variation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

De novo transcriptome assembly of drought tolerant CAM plants, Agave deserti and Agave tequilana.

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Gross, Stephen M; Martin, Jeffrey A; Simpson, June; Abraham-Juarez, María Jazmín; Wang, Zhong; Visel, Axel

2013-08-19

Agaves are succulent monocotyledonous plants native to xeric environments of North America. Because of their adaptations to their environment, including crassulacean acid metabolism (CAM, a water-efficient form of photosynthesis), and existing technologies for ethanol production, agaves have gained attention both as potential lignocellulosic bioenergy feedstocks and models for exploring plant responses to abiotic stress. However, the lack of comprehensive Agave sequence datasets limits the scope of investigations into the molecular-genetic basis of Agave traits. Here, we present comprehensive, high quality de novo transcriptome assemblies of two Agave species, A. tequilana and A. deserti, built from short-read RNA-seq data. Our analyses support completeness and accuracy of the de novo transcriptome assemblies, with each species having a minimum of approximately 35,000 protein-coding genes. Comparison of agave proteomes to those of additional plant species identifies biological functions of gene families displaying sequence divergence in agave species. Additionally, a focus on the transcriptomics of the A. deserti juvenile leaf confirms evolutionary conservation of monocotyledonous leaf physiology and development along the proximal-distal axis. Our work presents a comprehensive transcriptome resource for two Agave species and provides insight into their biology and physiology. These resources are a foundation for further investigation of agave biology and their improvement for bioenergy development.

Heterologous expression of Fusarium oxysporum tomatinase in Saccharomyces cerevisiae increases its resistance to saponins and improves ethanol production during the fermentation of Agave tequilana Weber var. azul and Agave salmiana must.

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Cira, Luis Alberto; González, Gloria Angélica; Torres, Juan Carlos; Pelayo, Carlos; Gutiérrez, Melesio; Ramírez, Jesús

2008-03-01

This paper describes the effect of the heterologous expression of tomatinase from Fusarium oxysporum f. sp lycopersici in Saccharomyces cerevisiae. The gene FoTom1 under the control of the S. cerevisiae phosphoglycerate kinase (PGK1) promoter was cloned into pYES2. S. cerevisiae strain Y45 was transformed with this vector and URA3 transformant strains were selected for resistance to alpha-tomatine. Two transformants were randomly selected for further study (designated Y45-1 and Y45-2). Control strain Y45 was inhibited at 50 muM alpha-tomatine, in contrast, transformants Y45-1 and Y45-2 did not show inhibition at 200 muM. Tomatinase activity was detected by HPLC monitoring tomatine disappearance and tomatidine appearance in the supernatants of culture medium. Maximum tomatinase activity was observed in the transformants after 6 h, remaining constant during the following 24 h. No tomatinase activity was detected in the parental strain. Moreover, the transformants were able to grow and produce ethanol in a mix of Agave tequilana Weber var. azul and Agave salmiana must, contrary to the Y45 strain which was unable to grow and ferment under these conditions.

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

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González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

2014-01-01

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

Class I KNOX genes are associated with organogenesis during bulbil formation in Agave tequilana.

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Abraham-Juárez, María Jazmín; Martínez-Hernández, Aída; Leyva-González, Marco Antonio; Herrera-Estrella, Luis; Simpson, June

2010-09-01

Bulbil formation in Agave tequilana was analysed with the objective of understanding this phenomenon at the molecular and cellular levels. Bulbils formed 14-45 d after induction and were associated with rearrangements in tissue structure and accelerated cell multiplication. Changes at the cellular level during bulbil development were documented by histological analysis. In addition, several cDNA libraries produced from different stages of bulbil development were generated and partially sequenced. Sequence analysis led to the identification of candidate genes potentially involved in the initiation and development of bulbils in Agave, including two putative class I KNOX genes. Real-time reverse transcription-PCR and in situ hybridization revealed that expression of the putative Agave KNOXI genes occurs at bulbil initiation and specifically in tissue where meristems will develop. Functional analysis of Agave KNOXI genes in Arabidopsis thaliana showed the characteristic lobed phenotype of KNOXI ectopic expression in leaves, although a slightly different phenotype was observed for each of the two Agave genes. An Arabidopsis KNOXI (knat1) mutant line (CS30) was successfully complemented with one of the Agave KNOX genes and partially complemented by the other. Analysis of the expression of the endogenous Arabidopsis genes KNAT1, KNAT6, and AS1 in the transformed lines ectopically expressing or complemented by the Agave KNOX genes again showed different regulatory patterns for each Agave gene. These results show that Agave KNOX genes are functionally similar to class I KNOX genes and suggest that spatial and temporal control of their expression is essential during bulbil formation in A. tequilana.

Functionally different PIN proteins control auxin flux during bulbil development in Agave tequilana.

Science.gov (United States)

Abraham Juárez, María Jazmín; Hernández Cárdenas, Rocío; Santoyo Villa, José Natzul; O'Connor, Devin; Sluis, Aaron; Hake, Sarah; Ordaz-Ortiz, José; Terry, Leon; Simpson, June

2015-07-01

In Agave tequilana, reproductive failure or inadequate flower development stimulates the formation of vegetative bulbils at the bracteoles, ensuring survival in a hostile environment. Little is known about the signals that trigger this probably unique phenomenon in agave species. Here we report that auxin plays a central role in bulbil development and show that the localization of PIN1-related proteins is consistent with altered auxin transport during this process. Analysis of agave transcriptome data led to the identification of the A. tequilana orthologue of PIN1 (denoted AtqPIN1) and a second closely related gene from a distinct clade reported as 'Sister of PIN1' (denoted AtqSoPIN1). Quantitative real-time reverse transcription-PCR (RT-qPCR) analysis showed different patterns of expression for each gene during bulbil formation, and heterologous expression of the A. tequilana PIN1 and SoPIN1 genes in Arabidopsis thaliana confirmed functional differences between these genes. Although no free auxin was detected in induced pedicel samples, changes in the levels of auxin precursors were observed. Taken as a whole, the data support the model that AtqPIN1 and AtqSoPIN1 have co-ordinated but distinct functions in relation to auxin transport during the initial stages of bulbil formation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Effect of Agave tequilana juice on cell wall polysaccharides of three Saccharomyces cerevisiae strains from different origins.

Science.gov (United States)

Aguilar-Uscanga, Blanca; Arrizon, Javier; Ramirez, Jesús; Solis-Pacheco, Josué

2007-02-01

In this study, a characterization of cell wall polysaccharide composition of three yeasts involved in the production of agave distilled beverages was performed. The three yeast strains were isolated from different media (tequila, mezcal and bakery) and were evaluated for the beta(1,3)-glucanase lytic activity and the beta-glucan/ mannan ratio during the fermentation of Agave tequilana juice and in YPD media (control). Fermentations were performed in shake flasks with 30 g l(-1) sugar concentration of A. tequilana juice and with the control YPD using 30 g l(-1) of glucose. The three yeasts strains showed different levels of beta-glucan and mannan when they were grown in A. tequilana juice in comparison to the YPD media. The maximum rate of cell wall lyses was 50% lower in fermentations with A. tequilana juice for yeasts isolated from tequila and mezcal than compared to the bakery yeast.

Effects of Agave tequilana fructans with different degree of polymerization profiles on the body weight, blood lipids and count of fecal Lactobacilli/Bifidobacteria in obese mice.

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Márquez-Aguirre, Ana Laura; Camacho-Ruiz, Rosa Maria; Arriaga-Alba, Myriam; Padilla-Camberos, Eduardo; Kirchmayr, Manuel Reinhart; Blasco, José Luis; González-Avila, Marisela

2013-08-01

Fructans are dietary fibers with beneficial effects on the gastrointestinal physiology and offer a promising approach for the treatment of some metabolic disorders associated with obesity. In vitro and in vivo studies were developed to test the safety of fructans obtained from Agave tequilana Weber var. azul. Additionally, an in vivo experiment using a diet-induced obesity model was performed to compare the effect of agave fructans with different degree of polymerization (DP) profiles: agave fructans with DP > 10 (LcF), agave FOS with DP agave fructans with and without demineralization (dTF, TF) versus commercial chicory fructans (OraftiSynergy1™) on the body weight change, fat, total cholesterol, triglycerides and count of fecal Lactobacillus spp. and Bifidobacterium spp. Results showed that A. tequilana fructans were not mutagenic and were safe even at a dose of 5 g per kg b.w. Obese mice that received ScF showed a significant decrease in body weight gain, fat tissue and total cholesterol without increasing the count of fecal Bifidobacteria. Whereas, obese mice that received LcF and TF showed decreased triglycerides and an increased count of fecal Bifidobacteria. Interestingly, although obese mice that received dTF did not show changes in body weight gain, fat tissue, total cholesterol or triglycerides, they showed an increase in the count of Bifidobacteria. These results demonstrate that both the degree of polymerization and the demineralization process can influence the biological activity of agave fructans.

Meiotic restitution mechanisms involved in the formation of 2n pollen in Agave tequilana Weber and Agave angustifolia Haw.

Science.gov (United States)

Gómez-Rodríguez, Víctor Manuel; Rodríguez-Garay, Benjamín; Barba-Gonzalez, Rodrigo

2012-01-01

A cytological analysis of the microsporogenesis was carried out in the Agave tequilana and A. angustifolia species. Several abnormalities such as chromosomal bridges, lagging chromosomes, micronuclei, monads, dyads and triads were found. The morphological analysis of the pollen, together with the above-mentioned 2n microspores, allowed us to confirm the presence of 2n pollen as well as its frequency. In both A. tequilana and A. angustifolia two different mechanisms were observed: the first mechanism, a failure in the cytokinesis in meiosis II caused the formation of dyads with two 2n cells and triads containing two n cells and one 2n cell; the second mechanism, involves an abnormal spindle, which caused the formation of triads with two n cells and one 2n cell. Likewise, the presence of monads was detected in both species, these, might be caused by a failure of the cytokinesis in both meiotic divisions. This is the first report about the presence of a Second Division Restitution mechanism (SDR) which causes the formation of 2n pollen in the genus Agave. The genetic implications of the presence of 2n pollen in the genus Agave are discussed.

Small heat-shock proteins and leaf cooling capacity account for the unusual heat tolerance of the central spike leaves in Agave tequilana var. Weber.

Science.gov (United States)

Luján, Rosario; Lledías, Fernando; Martínez, Luz María; Barreto, Rita; Cassab, Gladys I; Nieto-Sotelo, Jorge

2009-12-01

Agaves are perennial crassulacean acid metabolism (CAM) plants distributed in tropical and subtropical arid environments, features that are attractive for studying the heat-shock response. In agaves, the stress response can be analysed easily during leaf development, as they form a spirally shaped rosette, having the meristem surrounded by folded leaves in the centre (spike) and the unfolded and more mature leaves in the periphery. Here, we report that the spike of Agave tequilana is the most thermotolerant part of the rosette withstanding shocks of up to 55 degrees C. This finding was inconsistent with the patterns of heat-shock protein (Hsp) gene expression, as maximal accumulation of Hsp transcripts was at 44 degrees C in all sectors (spike, inner, middle and outer). However, levels of small HSP (sHSP)-CI and sHSP-CII proteins were conspicuously higher in spike leaves at all temperatures correlating with their thermotolerance. In addition, spike leaves showed a higher stomatal density and abated more efficiently their temperature several degrees below that of air. We propose that the greater capacity for leaf cooling during the day in response to heat stress, and the elevated levels of sHSPs, constitute part of a set of strategies that protect the SAM and folded leaves of A. tequilana from high temperatures.

EL Agave tequilana Weber Y LA PRODUCCIÓN DE TEQUILA EL Agave tequilana Weber Y LA PRODUCCIÓN DE TEQUILA

Directory of Open Access Journals (Sweden)

J. E. Barboza Corona

2012-02-01

Full Text Available Tequila is one of the most famous drinks on a national and worldwide level. It is obtained from the Agave tequilana Weber plant, better known as Agave Azul. The part of the plant used for making tequila is the core. Once the cores are cut, they are taken away to an oven where a cooking operation is made, this with the object of degrading the complex sugars of the core into simple sugars that can be used as yeasts in the fermentation process. The principal complex carbohydrate present in agave is inulin, which is a polymeric fructose with a terminal glucose residue. When the inulin is degraded by action of the juice´s acidity and the heat of cooking, fructose and glucose are obtained. Next, the cores are milled to extract the juice which is placed in vats and inoculated with a yeast culture of Saccharomyces cerevisiae, responsible for the fermentation of the sugars present in the juice. After fermentation, the juice is distilled to obtain ethanol and vinazes (a mixture of dead yeasts, nonfermentable sugars, and minerals. Tequila can be bottled immediately after distillation or it can be aged in the wooden casks wich confer characteristic flavor and color to tequila.El tequila es una de las bebidas más famosas a nivel nacional y mundial. Se obtiene de la planta Agave tequilana Weber, mejor conocido como Agave azul. La parte de la planta que es utilizada para la elaboración del tequila es la piña. Una vez que las piñas son cortadas, se llevan a un horno en donde se realiza la operación del cocimiento; éste tiene la finalidad de degradar los azúcares complejos presentes en la piña en azúcares simples para que puedan ser utilizados por la levadura en la operación de fermentación. El principal carbohidrato complejo presente en el agave es la inulina, el cual es un polímero de fructosa con un residuo terminal de glucosa. Cuando la inulina se degrada por la acción de la acidez del jugo y del calor en el cocimiento, se obtienen

Fermentation behaviour and volatile compound production by agave and grape must yeasts in high sugar Agave tequilana and grape must fermentations.

Science.gov (United States)

Arrizon, Javier; Fiore, Concetta; Acosta, Guillermina; Romano, Patrizia; Gschaedler, Anne

2006-01-01

Few studies have been performed on the characterization of yeasts involved in the production of agave distilled beverages and their individual fermentation properties. In this study, a comparison and evaluation of yeasts of different origins in the tequila and wine industries were carried out for technological traits. Fermentations were carried out in high (300 g l(-1)) and low (30 g l(-1)) sugar concentrations of Agave tequilana juice, in musts obtained from Fiano (white) and Aglianico (red) grapes and in YPD medium (with 270 g l(-1) of glucose added) as a control. Grape yeasts exhibited a reduced performance in high-sugar agave fermentation, while both agave and grape yeasts showed similar fermentation behaviour in grape musts. Production levels of volatile compounds by grape and agave yeasts differed in both fermentations.

Irritant contact dermatitis caused by needle-like calcium oxalate crystals, raphides, in Agave tequilana among workers in tequila distilleries and agave plantations.

Science.gov (United States)

Salinas, M L; Ogura, T; Soffchi, L

2001-02-01

It was found that needle-like calcium oxalate crystals, raphides, are found abundantly in all tissues of Agave tequilana plants; thus, 1 droplet (0.03 ml) of juice pressed from leaves contains 100-150 crystals, 30-500 microm in length, sharpened at both ends. In tequila distilleries, 5/6 of the workers who handle the agave stems have experienced the characteristic irritation. In contrast, only 1/3 of workers in agave plantations who harvest agave plants, complain of the irritation. It is confirmed that all the irritation suffered in both distilleries and plantations takes place at bodily locations where the plants come into contact with the worker's skin in the course of their work.

Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation.

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Casas-Godoy, Leticia; Arrizon, Javier; Arrieta-Baez, Daniel; Plou, Francisco J; Sandoval, Georgina

2016-08-01

Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Effect of Agave tequilana Weber Inulin on Postprandial Ghrelin Concentration in Obese Patients.

Science.gov (United States)

Contreras-Haro, Betsabe; Robles-Cervantes, Jose A; Gonzalez-Ortiz, Manuel; Martinez-Abundis, Esperanza; Espinel-Bermudez, Claudia; Gallegos-Arreola, Martha P; Morgado-Castillo, Karina C

2017-02-01

This study was performed to investigate the effect of Agave tequilana Weber inulin on postprandial ghrelin levels in obese patients. A randomized, double-blind, cross-over design was performed. A total of 14 patients were allocated into two groups: one group received a drink that contained 500 mL lemon water, 24 g of A. tequilana Weber inulin, and 75 g glucose and the other group received a placebo drink with 500 mL lemon drink and 75 g of glucose. After a 7-day washout period, the groups were crossed. The primary outcome measure was postprandial ghrelin levels between minute 240 and minute 270. A. tequilana Weber inulin did not change postprandial ghrelin concentration in obese patients.

Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

Science.gov (United States)

Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

2009-05-01

The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

Fermentation of Agave tequilana juice by Kloeckera africana: influence of amino-acid supplementations.

Science.gov (United States)

Valle-Rodríguez, Juan Octavio; Hernández-Cortés, Guillermo; Córdova, Jesús; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

2012-02-01

This study aimed to improve the fermentation efficiency of Kloeckera africana K1, in tequila fermentations. We investigated organic and inorganic nitrogen source requirements in continuous K. africana fermentations fed with Agave tequilana juice. The addition of a mixture of 20 amino-acids greatly improved the fermentation efficiency of this yeast, increasing the consumption of reducing sugars and production of ethanol, compared with fermentations supplemented with ammonium sulfate. The preference of K. africana for each of the 20 amino-acids was further determined in batch fermentations and we found that asparagine supplementation increased K. africana biomass production, reducing sugar consumption and ethanol production (by 30, 36.7 and 45%, respectively) over fermentations supplemented with ammonium sulfate. Therefore, asparagine appears to overcome K. africana nutritional limitation in Agave juice. Surprisingly, K. africana produced a high concentration of ethanol. This contrasts to poor ethanol productivities reported for other non-Saccharomyces yeasts indicating a relatively high ethanol tolerance for the K. africana K1 strain. Kloeckera spp. strains are known to synthesize a wide variety of volatile compounds and we have shown that amino-acid supplements influenced the synthesis by K. africana of important metabolites involved in the bouquet of tequila. The findings of this study have revealed important nutritional limitations of non-Saccharomyces yeasts fermenting Agave tequilana juice, and have highlighted the potential of K. africana in tequila production processes.

Expression of the 1-SST and 1-FFT genes and consequent fructan accumulation in Agave tequilana and A. inaequidens is differentially induced by diverse (a)biotic-stress related elicitors.

Science.gov (United States)

Suárez-González, Edgar Martín; López, Mercedes G; Délano-Frier, John P; Gómez-Leyva, Juan Florencio

2014-02-15

The expression of genes coding for sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99) and fructan:fructan 1-fructosyltransferase (1-FFT; EC 2.4.1.100), both fructan biosynthesizing enzymes, characterization by TLC and HPAEC-PAD, as well as the quantification of the fructo-oligosaccharides (FOS) accumulating in response to the exogenous application of sucrose, kinetin (cytokinin) or other plant hormones associated with (a)biotic stress responses were determined in two Agave species grown in vitro, domesticated Agave tequilana var. azul and wild A. inaequidens. It was found that elicitors such as salicylic acid (SA), and jasmonic acid methyl ester (MeJA) had the strongest effect on fructo-oligosaccharide (FOS) accumulation. The exogenous application of 1mM SA induced a 36-fold accumulation of FOS of various degrees of polymerization (DP) in stems of A. tequilana. Other treatments, such as 50mM abscisic acid (ABA), 8% Sucrose (Suc), and 1.0 mg L(-1) kinetin (KIN) also led to a significant accumulation of low and high DP FOS in this species. Conversely, treatment with 200 μM MeJA, which was toxic to A. tequilana, induced an 85-fold accumulation of FOS in the stems of A. inaequidens. Significant FOS accumulation in this species also occurred in response to treatments with 1mM SA, 8% Suc, and 10% polyethylene glycol (PEG). Maximum yields of 13.6 and 8.9 mg FOS per g FW were obtained in stems of A. tequilana and A. inaequidens, respectively. FOS accumulation in the above treatments was tightly associated with increased expression levels of either the 1-FFT or the 1-SST gene in tissues of both Agave species. Copyright © 2013 Elsevier GmbH. All rights reserved.

Fructan active enzymes (FAZY) activities and biosynthesis of fructooligosaccharides in the vacuoles of Agave tequilana Weber Blue variety plants of different age.

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Mellado-Mojica, Erika; González de la Vara, Luis E; López, Mercedes G

2017-02-01

Biosynthesis of agave fructans occurs in mesontle vacuoles which showed fluctuations in FAZY activities and synthesized a diverse spectrum of fructooligosaccharide isomers. Agave tequilana Weber Blue variety is an important agronomic crop in Mexico. Fructan metabolism in A. tequilana exhibits changes in fructan content, type, degree of polymerization (DP), and molecular structure. Specific activities of vacuolar fructan active enzymes (FAZY) in A. tequilana plants of different age and the biosynthesis of fructooligosaccharides (FOSs) were analyzed in this work. Vacuoles from mesontle (stem) protoplasts were isolated and collected from 2- to 7-year-old plants. For the first time, agave fructans were identified in the vacuolar content by HPAEC-PAD. Several FAZY activities (1-SST, 6-SFT, 6G-FFT, 1-FFT, and FEH) with fluctuations according to the plant age were found in protein vacuolar extracts. Among vacuolar FAZY, 1-SST activities appeared in all plant developmental stages, as well as 1-FFT and FEH activities. The enzymes 6G-FFT and 6-SST showed only minimal activities. Lowest and highest FAZY activities were found in 2- and 6-year-old plants, respectively. Synthesized products (FOS) were analyzed by TLC and HPAEC-PAD. Vacuolar FAZYs yielded large FOS isomers diversity, being 7-year-old plants the ones that synthesized a greater variety of fructans with different DP, linkages, and molecular structures. Based on the above, we are proposing a model for the FAZY activities constituting the FOS biosynthetic pathways in Agave tequilana Weber Blue variety.

Diversity and structure of landraces of Agave grown for spirits under traditional agriculture: A comparison with wild populations of A. angustifolia (Agavaceae) and commercial plantations of A. tequilana.

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Vargas-Ponce, Ofelia; Zizumbo-Villarreal, Daniel; Martínez-Castillo, Jaime; Coello-Coello, Julián; Colunga-Garcíamarín, Patricia

2009-02-01

Traditional farming communities frequently maintain high levels of agrobiodiversity, so understanding their agricultural practices is a priority for biodiversity conservation. The cultural origin of agave spirits (mezcals) from west-central Mexico is in the southern part of the state of Jalisco where traditional farmers cultivate more than 20 landraces of Agave angustifolia Haw. in agroecosystems that include in situ management of wild populations. These systems, rooted in a 9000-year-old tradition of using agaves as food in Mesoamerica, are endangered by the expansion of commercial monoculture plantations of the blue agave variety (A. tequilana Weber var. Azul), the only agave certified for sale as tequila, the best-known mezcal. Using intersimple sequence repeats and Bayesian estimators of diversity and structure, we found that A. angustifolia traditional landraces had a genetic diversity (H(BT) = 0.442) similar to its wild populations (H(BT) = 0.428) and a higher genetic structure ((B) = 0.405; (B) =0. 212). In contrast, the genetic diversity in the blue agave commercial system (H(B) = 0.118) was 73% lower. Changes to agave spirits certification laws to allow the conservation of current genetic, ecological and cultural diversity can play a key role in the preservation of the traditional agroecosystems.

Effects of Agave fructans (Agave tequilana Weber var. azul) on Body Fat and Serum Lipids in Obesity.

Science.gov (United States)

Padilla-Camberos, Eduardo; Barragán-Álvarez, Carla P; Diaz-Martinez, Nestor E; Rathod, Vineet; Flores-Fernández, José Miguel

2018-03-01

Obesity affects millions of people worldwide, constituting a public health problem associated with premature mortality. Agave fructans decrease fat mass, body and liver weight, and generate satiety in rodents. In the present study the effects of agave fructans on weight control, lipid profile, and physical tolerability were evaluated in obese people. Twenty-eight obese volunteers were randomly divided into two groups. In the first group, 96 mg/bw of agave fructans was administered for 12 weeks; in the second group, maltodextrin as a placebo was administered for 12 weeks. All participants consumed a low-calorie diet of 1500 kcal/day. Anthropometric and biochemical measurements were taken at baseline and at the end of the study. The body mass index (BMI) of the agave fructans treated group was reduced significantly from the baseline to the final measurements. Hip and waist circumferences decreased statistically in both groups. A decrease of 10% in total body fat was observed in the agave fructans treated group, resulting in a statistically significant difference in the final versus baseline measurements between the Agave fructans treated group and the placebo treated group. Triglycerides were reduced significantly in the agave fructans treated group. Glucose values did not change in either group. Agave fructans intake was safe and well tolerated throughout the study. The results showed that the ingestion of agave fructans enhanced the decrease in BMI, the decrease in total body fat, and the decrease in triglycerides in obese individuals who consume a low-calorie diet.

TOLERANCE OF AGAVE TEQUILANA TO HIGH LEVELS OF DIVALENT METAL CATIONS

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Elmi Roseida Cen-Cen

2015-11-01

Full Text Available Los agaves son plantas que pertenecen a un género constituido por numerosas especies, adaptadas para crecer en muy diversos hábitats, algunos con condiciones ambientales extremas. Distintas especies de agave crecen sobre distintos tipos de suelos, algunas en suelos con muy bajo contenido de nutrientes minerales y otras en suelos salinos o en suelos contaminados con iones metálicos. La relación planta-suelo ha sido escasamente estudiada en este género por lo que se desconoce, entre otras cuestiones, cuál es la capacidad de los agaves para absorber, transportar y almacenar nutrientes minerales, cuáles son los mecanismos celulares y bioquímicos que utilizan, o si poseen especial sensibilidad o tolerancia a los iones metálicos. Este estudio reporta el efecto de diversas concentraciones de sulfato de cadmio, cobalto, cobre, zinc o de manganeso sobre plántulas deAgave tequilana, bajo condiciones controladas de laboratorio; la concentración mínima de esos iones metálicos requerida para inducir un efecto tóxico visualmente detectable en tiempos cortos (ocho días; describimos los efectos tóxicos que estos metales generan sobre las plántulas de agave; y reportamos la cantidad de Cu2+, Cd2+ y Co2+ que se acumula en las hojas de plántulas de agave tratadas con altas concentraciones (milimolares de esos metales. Nuestros resultados muestran que, en experimentos de toxicidad aguda y bajo las condiciones aquí establecidas, elA. tequilanaposee una notable tolerancia a altas concentraciones de los distintos metales iónicos probados, incluyendo tanto micronutrientes como metales tóxicos, así como la capacidad de transportar en altas cantidades estos metales a tejido aéreo.

Characterization of three agave species by gas chromatography and solid-phase microextraction-gas chromatography-mass spectrometry.

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Peña-Alvarez, Araceli; Díaz, Laura; Medina, Alejandra; Labastida, Carmen; Capella, Santiago; Vera, Luz Elena

2004-02-20

Steam distillation (SD) extraction-solid-phase microextraction coupled to GC-MS was developed for the determination of terpenes and Bligh-Dyer extraction-derivatization coupled with GC for the determination of fatty acids such as ethyl esters were used. It was found that the three different Agave species have the same profile of fatty acids; the quantity of these compounds is different in each Agave variety. On the other hand, different terpenes were identified in the three Agave plants studied: nine in A. salmiana, eight in A. angustifolia and 32 in A. tequilana Weber var. azul.

Propuesta de una cosechadora-desmenuzadora de Agave tequilana Weber para la producción de bioetanol y revisión de los procedimientos existentes

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Salvador García Barrón

2012-03-01

Full Text Available Agave crop (Agave tequilana Weber is an option to produce bioethanol as biofuel. By-hand-harvesting of agave is 75 % of crop production costs, resulting in a higher production cost of bioethanol than for other crops. This paper presents a proposal of agave shredder-harvester, for which are considered: existing proposals, the methodology of current crop harvest, agricultural machines and mechanisms of interest, requirements of the raw material for bioethanol production. Agave harvester proposed considers shredding of leaves and pineapple retaking ideas of gridding mechanisms such as milling of agave, shredding crop residues machines. The mechanization of the harvest of agave for production of bioethanol presents feasibility that will require a research to design, the crushing mechanism, its blades, geometry and dimensions, and the power required to measure different elements of the combine harvester in the crushing operation, as well as other variables.El Agave tequilana Weber es una opción para la producción de bioetanol combustible. La cosecha manual del agave representa el 75 % de los costos de producción del cultivo, lo que ocasiona un mayor costo de producción del bioetanol que para otros cultivos. En este trabajo se presenta una propuesta de cosechadora-desmenuzadora de agave, para lo cual se consideran: propuestas existentes, la metodología de cosecha actual, máquinas agrícolas con mecanismos de interés y los requerimientos de la materia prima para producir bioetanol. La cosechadora propuesta considera el desmenuzado de hojas y piña en campo, retomando ideas de mecanismos empleados en molinos de piña de agave y desmenuzadoras agrícolas. La cosecha mecanizada de agave para producción de bioetanol presenta viabilidad técnica que requerirá una investigación para diseñar el mecanismo desmenuzador, su disposición geométrica y dimensiones, así como la potencia requerida en el desmenuzado, con el fin de dimensionar distintos

Effect of gamma rays in embryogenic callus of agave tequilana weber var. blue and in vitro selection for resistance to pathogens

International Nuclear Information System (INIS)

Rubluo, A.; Brunner, I.; Rodriguez-Garay, B.; Rodriguez-Dominguez, J.M.; Santacruz-Ruvalcava, F.; De la Cruz, E.; Gonzalez, J.

1999-01-01

Agave tequilana from which tequila is done, suffers genetic erosion leaving the plant susceptible to pathogens. Recently, a pest invades the tequilana fields. To face this problem we designed experiments to induce mutations for disease resistance. Our aims were: to analyse the in vitro responses of embryogenic callus exposed to gamma rays, to determine the LD50 and challenge surviving embryos to crude bacterial extracts (CBE). Axillary buds were cultured in vitro. Leaves from the former plant lets were used as explants to induce embryogenic callus. Samples of 1g embryogenic callus were irradiated from 5 to 40 Gy of CO 60 gamma rays. Effects were recorded at 15, 30 and 45 days after irradiation. The CBE was obtained from isolated bacteria collected from sick field plants. Embryogenic calli were irradiated at 0, 15, 25 and 40 Gy and challenged with the CBE at 0, 10 and 20 % v/v. Embryo expression (globular, white and green cucumber shaped) were affected as a function of the dose. However at low doses (5-15 Gy) globular forms increased its production. On the contrary , green cucumber shaped embryos were severely affected. However, even at high doses (30, 35 and 40 Gy) healthy green forms were recorded. When the embryogenic callus was challenged to the CBE, high mortality was recorded, although, some green forms survived at high radiation doses and high CBE concentrations. Because of the unicellular origin of the somatic embryos, solid mutants can be expected

Agave tequilana MADS genes show novel expression patterns in meristems, developing bulbils and floral organs.

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Delgado Sandoval, Silvia del Carmen; Abraham Juárez, María Jazmín; Simpson, June

2012-03-01

Agave tequilana is a monocarpic perennial species that flowers after 5-8 years of vegetative growth signaling the end of the plant's life cycle. When fertilization is unsuccessful, vegetative bulbils are induced on the umbels of the inflorescence near the bracteoles from newly formed meristems. Although the regulation of inflorescence and flower development has been described in detail for monocarpic annuals and polycarpic species, little is known at the molecular level for these processes in monocarpic perennials, and few studies have been carried out on bulbils. Histological samples revealed the early induction of umbel meristems soon after the initiation of the vegetative to inflorescence transition in A. tequilana. To identify candidate genes involved in the regulation of floral induction, a search for MADS-box transcription factor ESTs was conducted using an A. tequilana transcriptome database. Seven different MIKC MADS genes classified into 6 different types were identified based on previously characterized A. thaliana and O. sativa MADS genes and sequences from non-grass monocotyledons. Quantitative real-time PCR analysis of the seven candidate MADS genes in vegetative, inflorescence, bulbil and floral tissues uncovered novel patterns of expression for some of the genes in comparison with orthologous genes characterized in other species. In situ hybridization studies using two different genes showed expression in specific tissues of vegetative meristems and floral buds. Distinct MADS gene regulatory patterns in A. tequilana may be related to the specific reproductive strategies employed by this species.

Physiological effects of dietary fructans extracted from Agave tequilana Gto. and Dasylirion spp.

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Urías-Silvas, Judith E; Cani, Patrice D; Delmée, Evelyne; Neyrinck, Audrey; López, Mercedes G; Delzenne, Nathalie M

2008-02-01

Recent data reported that inulin-type fructans extracted from chicory roots regulate appetite and lipid/glucose metabolism, namely, by promoting glucagon-like peptide-1 (GLP-1) production in the colon. The Agave genus growing in different regions of Mexico also contains important amounts of original fructans, with interesting nutritional and technological properties, but only few data report their physiological effect when added in the diet. Therefore, we decided to evaluate in parallel the effect of supplementation with 10 % agave or chicory fructans on glucose and lipid metabolism in mice. Male C57Bl/6J mice were fed a standard (STD) diet or diet supplemented with Raftilose P95 (RAF), fructans from Agave tequilana Gto. (TEQ) or fructans from Dasylirion spp. (DAS) for 5 weeks. The body weight gain and food intake in mice fed fructans-containing diets were significantly lower than the ones of mice fed the STD diet, TEQ leading to the lowest value. Serum glucose and cholesterol were similarly lower in all fructans-fed groups than in the STD group and correlated to body weight gain. Only RAF led to a significant decrease in serum TAG. As previously shown for RAF, the supplementation with agave fructans (TEQ and DAS) induced a higher concentration of GLP-1 and its precursor, proglucagon mRNA, in the different colonic segments, thus suggesting that fermentable fructans from different botanical origin and chemical structure are able to promote the production of satietogenic/incretin peptides in the lower part of the gut, with promising effects on glucose metabolism, body weight and fat mass development.

Molecular and functional characterization of novel fructosyltransferases and invertases from Agave tequilana.

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Celso Cortés-Romero

Full Text Available Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and structure/function relationships, two different genes were predicted to encode 1-SST and 6G-FFT type fructosyltransferases, in addition, 4 genes encoding putative cell wall invertases and 4 genes encoding putative vacuolar invertases were also identified. Probable functions for each gene, were assigned based on conserved amino acid sequences and confirmed for 2 fructosyltransferases and one invertase by analyzing the enzymatic activity of recombinant Agave protein s expressed and purified from Pichia pastoris. The genome organization of the fructosyltransferase/invertase genes, for which the corresponding cDNA contained the complete open reading frame, was found to be well conserved since all genes were shown to carry a 9 bp mini-exon and all showed a similar structure of 8 exons/7 introns with the exception of a cell wall invertase gene which has 7 exons and 6 introns. Fructosyltransferase genes were strongly expressed in the storage organs of the plants, especially in vegetative stages of development and to lower levels in photosynthetic tissues, in contrast to the invertase genes where higher levels of expression were observed in leaf tissues and in mature plants.

Molecular and functional characterization of novel fructosyltransferases and invertases from Agave tequilana.

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Cortés-Romero, Celso; Martínez-Hernández, Aída; Mellado-Mojica, Erika; López, Mercedes G; Simpson, June

2012-01-01

Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and structure/function relationships, two different genes were predicted to encode 1-SST and 6G-FFT type fructosyltransferases, in addition, 4 genes encoding putative cell wall invertases and 4 genes encoding putative vacuolar invertases were also identified. Probable functions for each gene, were assigned based on conserved amino acid sequences and confirmed for 2 fructosyltransferases and one invertase by analyzing the enzymatic activity of recombinant Agave protein s expressed and purified from Pichia pastoris. The genome organization of the fructosyltransferase/invertase genes, for which the corresponding cDNA contained the complete open reading frame, was found to be well conserved since all genes were shown to carry a 9 bp mini-exon and all showed a similar structure of 8 exons/7 introns with the exception of a cell wall invertase gene which has 7 exons and 6 introns. Fructosyltransferase genes were strongly expressed in the storage organs of the plants, especially in vegetative stages of development and to lower levels in photosynthetic tissues, in contrast to the invertase genes where higher levels of expression were observed in leaf tissues and in mature plants.

Identificación del agente causal del anillo rojo del agave tequilero (Agave tequilana Weber var. Azul).

OpenAIRE

Mezo Villalobos, Miriam

2014-01-01

El cultivo del agave tequilero es parte de una larga tradición del estado de Jalisco, México. Esta actividad que culmina con la obtención del tequila, un tipo de mezcal tan característico, que se ha legislado su producción bajo la Denominación de Origen. La cadena producto agave-tequila es de suma importancia económica y social, no sólo para la región productora, sino para el país, dadas las elevadas cantidades de tequila que se exportan a todo el mundo. Esta investigación tuvo como objetivo ...

Effects of consuming diets containing Agave tequilana dietary fibre and jamaica calyces on body weight gain and redox status in hypercholesterolemic rats.

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Sáyago-Ayerdi, Sonia G; Mateos, Raquel; Ortiz-Basurto, Rosa I; Largo, Carlota; Serrano, José; Granado-Serrano, Ana Belén; Sarriá, Beatriz; Bravo, Laura; Tabernero, María

2014-04-01

Dietary fibre (DF) obtained from Agave tequilana, which is rich in fructans and insoluble DF, and jamaica calyces (Hibiscus sabdariffa), which is rich in DF and phenolic compounds, were assessed as new potential functional ingredients using the hypercholesterolemic animal model. Wistar rats (200-250 g) were divided into 3 groups (n=8) and fed with cholesterol-rich diets supplemented with cellulose (CC, control), agave DF (ADF) or ADF with jamaica calyces (ADF-JC). After consuming the test diets for 5 weeks, weight gain in the ADF-JC group was significantly lower than in the other groups. The ADF and ADF-JC groups had a reduced concentration of cholesterol transporters in the caecum tissue, although no changes were observed in the plasma lipid profile. Both treatments improved the redox status by reducing the malondialdehyde serum levels and protein oxidative damage, compared to the CC group. DF from A. tequilana alone, or in combination with jamaica calyces, shows promising potential as a bioactive ingredient. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of sodium hypochlorite on Agave tequilana Weber bagasse fibers used to elaborate cyto and biocompatible hydrogel films.

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Tovar-Carrillo, Karla Lizette; Nakasone, Kazuki; Sugita, Satoshi; Tagaya, Motohiro; Kobayashi, Takaomi

2014-09-01

Waste bagasse of Agave tequilana-Weber fibers treated with sodium hydroxide was used to elaborate hydrogel films. The bagasse was offered in an alternative use for the preparation of hydrogel films by phase inversion method without crosslinking and further purification of cellulose. The effect on the properties of the obtained films was studied when the chemical treatment of the agave fibers was changed. It was found that the resultant hydrogels showed increment in tensile from 40 N/mm(2) to 56 N/mm(2) with the increase of sodium hypochlorite concentration from 1 to 10 vol.%, respectively. With regard to biocompatibility properties of the hydrogel films, platelet adhesion, clotting time and protein adsorption were investigated. Analysis of the morphology of adherent NIH3T3 fibroblast indicated that the projected cell area, aspect ratio and long axis gradually increased with the increment of sodium hypochlorite content in the agave treatment. It was presented that the chemical treatment affects cell adhesion and morphology and lignin content remains in the brown fibers. Copyright © 2014 Elsevier B.V. All rights reserved.

Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

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Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

2013-04-01

In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

AGRONOMIC MANAGEMENT PRACTICES FOR SUSTAINABILITY: CHARACTERISTICS AND MEASUREMENT IN Agave tequilana Weber IN THE SIERRA DE AMULA REGION, JALISCO

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Arturo Moreno Hernández

2010-10-01

Full Text Available This article qualitative evaluation of the sustainable management in blue agave (Agave tequilana Weber agroecosystems, in Sierra Amula region of the Jalisco state, Mexico. Sixteen sites were evaluated in an altitudinal gradient ranging from 777 to 1345 masl. Six principles considered by Altieri (1999 as the basic elements of a sustainable management of the agroecosystem, were used to construct an Index of Agroecosystem Sustainable Management (IMSA. Four levels of this index were identified: values lower than 50 % were considered unsustainable management, 51 to 66.6 % scarcely sustainable management, 66.7 to 83.2 % mediumly sustainable management and 83.3 to 100 % highly sustainable management. Of the 16 sites evaluated, two were classified as unsustainable management, six was scarcely sustainable management, five as medially sustainable management and three as highly sustainable management.

Cellular and molecular changes associated with somatic embryogenesis induction in Agave tequilana.

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Portillo, L; Olmedilla, A; Santacruz-Ruvalcaba, F

2012-10-01

In spite of the importance of somatic embryogenesis for basic research in plant embryology as well as for crop improvement and plant propagation, it is still unclear which mechanisms and cell signals are involved in acquiring embryogenic competence by a somatic cell. The aim of this work was to study cellular and molecular changes involved in the induction stage in calli of Agave tequilana Weber cultivar azul in order to gain more information on the initial stages of somatic embryogenesis in this species. Cytochemical and immunocytochemical techniques were used to identify differences between embryogenic and non-embryogenic cells from several genotypes. Presence of granular structures was detected after somatic embryogenesis induction in embryogenic cells; composition of these structures as well as changes in protein and polysaccharide distribution was studied using Coomassie brilliant blue and Periodic Acid-Schiff stains. Distribution of arabinogalactan proteins (AGPs) and pectins was investigated in embryogenic and non-embryogenic cells by immunolabelling using anti-AGP monoclonal antibodies (JIM4, JIM8 and JIM13) as well as an anti-methyl-esterified pectin-antibody (JIM7), in order to evaluate major modifications in cell wall composition in the initial stages of somatic embryogenesis. Our observations pointed out that induction of somatic embryogenesis produced accumulation of proteins and polysaccharides in embryogenic cells. Presence of JIM8, JIM13 and JIM7 epitopes were detected exclusively in embryogenic cells, which supports the idea that specific changes in cell wall are involved in the acquisition of embryogenic competence of A. tequilana.

Use of Agave tequilana-lignin and zinc oxide nanoparticles for skin photoprotection.

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Gutiérrez-Hernández, José Manuel; Escalante, Alfredo; Murillo-Vázquez, Raquel Nalleli; Delgado, Ezequiel; González, Francisco Javier; Toríz, Guillermo

2016-10-01

The use of sunscreens is essential for preventing skin damage and the potential appearance of skin cancer in humans. Inorganic active components such as zinc oxide (ZnO) have been used commonly in sunscreens due to their ability to block UVA radiation. This ultraviolet (UV) protection might be enhanced to cover the UVB and UVC bands when combined with other components such as titanium dioxide (TiO2). In this work we evaluate the photoprotection properties of organic nanoparticles made from lignin in combination with ZnO nanoparticles as active ingredients for sunscreens. Lignin nanoparticles were synthesized from Agave tequilana lignin. Two different pulping methods were used for dissolving lignin from agave bagasse. ZnO nanoparticles were synthesized by the precipitation method. All nanoparticles were characterized by SEM, UV-Vis and FT-IR spectroscopy. Nanoparticles were mixed with a neutral vehicle in different concentrations and in-vitro sun protection factor (SPF) values were calculated. Different sizes of spherical lignin nanoparticles were obtained from the spent liquors of two different pulping methods. ZnO nanoparticles resulted with a flake shape. The mixture of all components gave SPF values in a range between 4 and 13. Lignin nanoparticles showed absorption in the UVB and UVC regions which can enhance the SPF value of sunscreens composed only of zinc oxide nanoparticles. Lignin nanoparticles have the added advantage of being of organic nature and its brown color can be used to match the skin tone of the person using it. Copyright © 2016 Elsevier B.V. All rights reserved.

Improvement on the productivity of continuous tequila fermentation by Saccharomyces cerevisiae of Agave tequilana juice with supplementation of yeast extract and aeration.

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Hernández-Cortés, Guillermo; Valle-Rodríguez, Juan Octavio; Herrera-López, Enrique J; Díaz-Montaño, Dulce María; González-García, Yolanda; Escalona-Buendía, Héctor B; Córdova, Jesús

2016-12-01

Agave (Agave tequilana Weber var. azul) fermentations are traditionally carried out employing batch systems in the process of tequila manufacturing; nevertheless, continuous cultures could be an attractive technological alternative to increase productivity and efficiency of sugar to ethanol conversion. However, agave juice (used as a culture medium) has nutritional deficiencies that limit the implementation of yeast continuous fermentations, resulting in high residual sugars and low fermentative rates. In this work, fermentations of agave juice using Saccharomyces cerevisiae were put into operation to prove the necessity of supplementing yeast extract, in order to alleviate nutritional deficiencies of agave juice. Furthermore, continuous fermentations were performed at two different aeration flow rates, and feeding sterilized and non-sterilized media. The obtained fermented musts were subsequently distilled to obtain tequila and the preference level was compared against two commercial tequilas, according to a sensorial analysis. The supplementation of agave juice with air and yeast extract augmented the fermentative capacity of S. cerevisiae S1 and the ethanol productivities, compared to those continuous fermentations non supplemented. In fact, aeration improved ethanol production from 37 to 40 g L(-1), reducing sugars consumption from 73 to 88 g L(-1) and ethanol productivity from 3.0 to 3.2 g (Lh)(-1), for non-aerated and aerated (at 0.02 vvm) cultures, respectively. Supplementation of yeast extract allowed an increase in specific growth rate and dilution rates (0.12 h(-1), compared to 0.08 h(-1) of non-supplemented cultures), ethanol production (47 g L(-1)), reducing sugars consumption (93 g L(-1)) and ethanol productivity [5.6 g (Lh)(-1)] were reached. Additionally, the effect of feeding sterilized or non-sterilized medium to the continuous cultures was compared, finding no significant differences between both types of cultures. The overall effect

Immunomodulatory Effect of Agave tequilana Evaluated on an Autoimmunity Like-SLE Model Induced in Balb/c Mice with Pristane.

Science.gov (United States)

Gutiérrez Nava, Zúlima Jannette; Jiménez-Aparicio, Antonio Ruperto; Herrera-Ruiz, Maribel Lucila; Jiménez-Ferrer, Enrique

2017-05-25

In this work, the immunomodulatory activity of the acetone extract and the fructans obtained from Agave tequilana were evaluated, on the systemic autoimmunity type-SLE model generated by the administration of 2,6,10,14-tetramethylpentadecane (TMPD, also known as pristane) on Balb/c female mice. The systemic autoimmunity type-SLE was observed seven months after the application of TMPD, in which the animals from the negative control group (animals with damage and without any other treatment) developed articular inflammation, proteinuria, an increment of the antinuclear antibody titters and tissue pro-inflammatory cytokines levels (IL-1β, IL-6, TNF-α e IFN-γ) as well as the anti-inflammatory cytokine IL-10. The administration of the different treatments and the extracts of A. tequilana , provoked the decrease of: articular inflammation, the development of proteinuria, ssDNA/dsDNA antinuclear antibody titters and cytokines IL-1β, IL-6, TNF-α, IFN-γ and IL-10. The phytochemical analysis of the acetone extract identified the presence of the following compounds: β-sitosterol glycoside; 3,7,11,15-tetramethyl-2-hexadecen-1-ol (phytol); octadecadienoic acid-2,3-dihydroxypropyl ester; stigmasta-3,5-dien-7-one; cycloartenone and cycloartenol. Therefore, A. tequilana contains active compounds with the capacity to modify the evolution of the systemic autoimmunity type-SLE on a murine model.

Immunomodulatory Effect of Agave tequilana Evaluated on an Autoimmunity Like-SLE Model Induced in Balb/c Mice with Pristane

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Zúlima Jannette Gutiérrez Nava

2017-05-01

Full Text Available In this work, the immunomodulatory activity of the acetone extract and the fructans obtained from Agave tequilana were evaluated, on the systemic autoimmunity type-SLE model generated by the administration of 2,6,10,14-tetramethylpentadecane (TMPD, also known as pristane on Balb/c female mice. The systemic autoimmunity type-SLE was observed seven months after the application of TMPD, in which the animals from the negative control group (animals with damage and without any other treatment developed articular inflammation, proteinuria, an increment of the antinuclear antibody titters and tissue pro-inflammatory cytokines levels (IL-1β, IL-6, TNF-α e IFN-γ as well as the anti-inflammatory cytokine IL-10. The administration of the different treatments and the extracts of A. tequilana, provoked the decrease of: articular inflammation, the development of proteinuria, ssDNA/dsDNA antinuclear antibody titters and cytokines IL-1β, IL-6, TNF-α, IFN-γ and IL-10. The phytochemical analysis of the acetone extract identified the presence of the following compounds: β-sitosterol glycoside; 3,7,11,15-tetramethyl-2-hexadecen-1-ol (phytol; octadecadienoic acid-2,3-dihydroxypropyl ester; stigmasta-3,5-dien-7-one; cycloartenone and cycloartenol. Therefore, A. tequilana contains active compounds with the capacity to modify the evolution of the systemic autoimmunity type-SLE on a murine model.

Cytophotometric and biochemical analyses of DNA in pentaploid and diploid Agave species.

Science.gov (United States)

Cavallini, A; Natali, L; Cionini, G; Castorena-Sanchez, I

1996-04-01

Nuclear DNA content, chromatin structure, and DNA composition were investigated in four Agave species: two diploid, Agave tequilana Weber and Agave angustifolia Haworth var. marginata Hort., and two pentaploid, Agave fourcroydes Lemaire and Agave sisalana Perrine. It was determined that the genome size of pentaploid species is nearly 2.5 times that of diploid ones. Cytophotometric analyses of chromatin structure were performed following Feulgen or DAPI staining to determine optical density profiles of interphase nuclei. Pentaploid species showed higher frequencies of condensed chromatin (heterochromatin) than diploid species. On the other hand, a lower frequency of A-T rich (DAPI stained) heterochromatin was found in pentaploid species than in diploid ones, indicating that heterochromatin in pentaploid species is made up of sequences with base compositions different from those of diploid species. Since thermal denaturation profiles of extracted DNA showed minor variations in the base composition of the genomes of the four species, it is supposed that, in pentaploid species, the large heterochromatin content is not due to an overrepresentation of G-C repetitive sequences but rather to the condensation of nonrepetitive sequences, such as, for example, redundant gene copies switched off in the polyploid complement. It is suggested that speciation in the genus Agave occurs through point mutations and minor DNA rearrangements, as is also indicated by the relative stability of the karyotype of this genus. Key words : Agave, DNA cytophotometry, DNA melting profiles, chromatin structure, genome size.

Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

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Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

2014-11-06

Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes.

Fructans from Agave tequilana with a Lower Degree of Polymerization Prevent Weight Gain, Hyperglycemia and Liver Steatosis in High-Fat Diet-Induced Obese Mice.

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Márquez-Aguirre, A L; Camacho-Ruíz, R M; Gutiérrez-Mercado, Y K; Padilla-Camberos, E; González-Ávila, M; Gálvez-Gastélum, F J; Díaz-Martínez, N E; Ortuño-Sahagún, D

2016-12-01

Fructans from agave have received specific attention because of their highly branched fructan content. We have previously reported that the degree of polymerization (dp) influences their biological activity. Therefore, the aim of this study was to investigate the effect of unfractionated and fractionated fructans (higher and lower dps) from Agave tequilana in high-fat diet-induced (HFD) obese mice. Fructans with a lower dp (HFD+ScF) decreased weight gain by 30 %, body fat mass by 51 %, hyperglycemia by 25 % and liver steatosis by 40 %. Interestingly, unfractionated fructans (HFD+F) decreased glucose and triglycerides (TG), whereas fractionated fructans with a higher dp (HFD+LcF) decreased TG but not glucose; in contrast, HFD+ScF decreased glucose but not TG. Our findings suggest that both higher and lower dp agave fructans have complementary effects in metabolic disorders related to obesity. These findings may contribute to the development of improved food supplements with a specific ratio combination of fructans with different dps.

Conversion of lignocellulosic agave residues into liquid biofuels using an AFEX™-based biorefinery.

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Flores-Gómez, Carlos A; Escamilla Silva, Eleazar M; Zhong, Cheng; Dale, Bruce E; da Costa Sousa, Leonardo; Balan, Venkatesh

2018-01-01

Agave-based alcoholic beverage companies generate thousands of tons of solid residues per year in Mexico. These agave residues might be used for biofuel production due to their abundance and favorable sustainability characteristics. In this work, agave leaf and bagasse residues from species Agave tequilana and Agave salmiana were subjected to pretreatment using the ammonia fiber expansion (AFEX) process. The pretreatment conditions were optimized using a response surface design methodology. We also identified commercial enzyme mixtures that maximize sugar yields for AFEX-pretreated agave bagasse and leaf matter, at ~ 6% glucan (w/w) loading enzymatic hydrolysis. Finally, the pretreated agave hydrolysates (at a total solids loading of ~ 20%) were used for ethanol fermentation using the glucose- and xylose-consuming strain Saccharomyces cerevisiae 424A (LNH-ST), to determine ethanol yields at industrially relevant conditions. Low-severity AFEX pretreatment conditions are required (100-120 °C) to enable efficient enzymatic deconstruction of the agave cell wall. These studies showed that AFEX-pretreated A. tequilana bagasse, A. tequilana leaf fiber, and A. salmiana bagasse gave ~ 85% sugar conversion during enzyme hydrolysis and over 90% metabolic yields of ethanol during fermentation without any washing step or nutrient supplementation. On the other hand, although lignocellulosic A. salmiana leaf gave high sugar conversions, the hydrolysate could not be fermented at high solids loadings, apparently due to the presence of natural inhibitory compounds. These results show that AFEX-pretreated agave residues can be effectively hydrolyzed at high solids loading using an optimized commercial enzyme cocktail (at 25 mg protein/g glucan) producing > 85% sugar conversions and over 40 g/L bioethanol titers. These results show that AFEX technology has considerable potential to convert lignocellulosic agave residues to bio-based fuels and chemicals in a biorefinery.

Agave: a biofuel feedstock for arid and semi-arid environments

Energy Technology Data Exchange (ETDEWEB)

Gross, Stephen; Martin, Jeffrey; Simpson, June; Wang, Zhong; Visel, Axel

2011-05-31

Efficient production of plant-based, lignocellulosic biofuels relies upon continued improvement of existing biofuel feedstock species, as well as the introduction of newfeedstocks capable of growing on marginal lands to avoid conflicts with existing food production and minimize use of water and nitrogen resources. To this end, specieswithin the plant genus Agave have recently been proposed as new biofuel feedstocks. Many Agave species are adapted to hot and arid environments generally unsuitable forfood production, yet have biomass productivity rates comparable to other second-generation biofuel feedstocks such as switchgrass and Miscanthus. Agavesachieve remarkable heat tolerance and water use efficiency in part through a Crassulacean Acid Metabolism (CAM) mode of photosynthesis, but the genes andregulatory pathways enabling CAM and thermotolerance in agaves remain poorly understood. We seek to accelerate the development of agave as a new biofuelfeedstock through genomic approaches using massively-parallel sequencing technologies. First, we plan to sequence the transcriptome of A. tequilana to provide adatabase of protein-coding genes to the agave research community. Second, we will compare transcriptome-wide gene expression of agaves under different environmentalconditions in order to understand genetic pathways controlling CAM, water use efficiency, and thermotolerance. Finally, we aim to compare the transcriptome of A.tequilana with that of other Agave species to gain further insight into molecular mechanisms underlying traits desirable for biofuel feedstocks. These genomicapproaches will provide sequence and gene expression information critical to the breeding and domestication of Agave species suitable for biofuel production.

Improvement of growth, fermentative efficiency and ethanol tolerance of Kloeckera africana during the fermentation of Agave tequilana juice by addition of yeast extract.

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Díaz-Montaño, Dulce M; Favela-Torres, Ernesto; Córdova, Jesus

2010-01-30

The aim of this work was to improve the productivity and yield of tequila fermentation and to propose the use of a recently isolated non-Saccharomyces yeast in order to obtain a greater diversity of flavour and aroma of the beverage. For that, the effects of the addition of different nitrogen (N) sources to Agave tequilana juice on the growth, fermentative capacity and ethanol tolerance of Kloeckera africana and Saccharomyces cerevisiae were studied and compared. Kloeckera africana K1 and S. cerevisiae S1 were cultured in A. tequilana juice supplemented with ammonium sulfate, diammonium phosphate or yeast extract. Kloeckera africana did not assimilate inorganic N sources, while S. cerevisiae utilised any N source. Yeast extract stimulated the growth, fermentative capacity and alcohol tolerance of K. africana, giving kinetic parameter values similar to those calculated for S. cerevisiae. This study revealed the importance of supplementing A. tequilana juice with a convenient N source to achieve fast and complete conversion of sugars in ethanol, particularly in the case of K. africana. This yeast exhibited similar growth and fermentative capacity to S. cerevisiae. The utilisation of K. africana in the tequila industry is promising because of its variety of synthesised aromatic compounds, which would enrich the attributes of this beverage. (c) 2009 Society of Chemical Industry.

Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

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Corbin, Kendall R; Byrt, Caitlin S; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A M; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T; Bacic, Antony; Fincher, Geoffrey B; Betts, Natalie S; Burton, Rachel A

2015-01-01

Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w) and non-cellulosic polysaccharides (16-22% w/w), and whole leaves were low in lignin (9-13% w/w). Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition.

Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

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Kendall R Corbin

Full Text Available Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w and non-cellulosic polysaccharides (16-22% w/w, and whole leaves were low in lignin (9-13% w/w. Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition.

Simple methods for in vitro pollen germination and pollen preservation of selected species of the genus Agave

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Sigifredo López Díaz

2008-01-01

Full Text Available Simple methods to evaluate the viability and to preserve Agave tequilana Weber var. azul and A. angustifolia Haw pollen were established. Pollen viability was assessed by improving a growing media and evaluating three common pollen germination media components: sucrose, boric acid, and calcium ion. Optimal germination of pollen was obtained at 0.300 M sucrose, 0.324 mM boric acid, and 1.219 mM calcium nitrate and incubated at a temperature of 25°C. Agave pollen was preserved in olive oil and organic solvents. Olive oil, which is immiscible with water, provides an anhydrous environment and limits available oxygen, conditions similar to those provided by some organic solvents. Fresh pollen was put into eppendorf tubes containing n-butanol, n-propanol, isopropanol, extra virgin olive oil and preserved at -20, 4, and 25°C. The germination of the preserved pollen was scored at different time periods during preservation employing the optimal germination medium. The viability of pollen grains preserved at -20°C in olive oil, proved olive oil as an efficient medium for agave pollen preservation for at least 6 months.

Transcriptome analysis identifies genes involved in ethanol response of Saccharomyces cerevisiae in Agave tequilana juice.

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Ramirez-Córdova, Jesús; Drnevich, Jenny; Madrigal-Pulido, Jaime Alberto; Arrizon, Javier; Allen, Kirk; Martínez-Velázquez, Moisés; Alvarez-Maya, Ikuri

2012-08-01

During ethanol fermentation, yeast cells are exposed to stress due to the accumulation of ethanol, cell growth is altered and the output of the target product is reduced. For Agave beverages, like tequila, no reports have been published on the global gene expression under ethanol stress. In this work, we used microarray analysis to identify Saccharomyces cerevisiae genes involved in the ethanol response. Gene expression of a tequila yeast strain of S. cerevisiae (AR5) was explored by comparing global gene expression with that of laboratory strain S288C, both after ethanol exposure. Additionally, we used two different culture conditions, cells grown in Agave tequilana juice as a natural fermentation media or grown in yeast-extract peptone dextrose as artificial media. Of the 6368 S. cerevisiae genes in the microarray, 657 genes were identified that had different expression responses to ethanol stress due to strain and/or media. A cluster of 28 genes was found over-expressed specifically in the AR5 tequila strain that could be involved in the adaptation to tequila yeast fermentation, 14 of which are unknown such as yor343c, ylr162w, ygr182c, ymr265c, yer053c-a or ydr415c. These could be the most suitable genes for transforming tequila yeast to increase ethanol tolerance in the tequila fermentation process. Other genes involved in response to stress (RFC4, TSA1, MLH1, PAU3, RAD53) or transport (CYB2, TIP20, QCR9) were expressed in the same cluster. Unknown genes could be good candidates for the development of recombinant yeasts with ethanol tolerance for use in industrial tequila fermentation.

Simultaneous saccharification and fermentation of Agave tequilana fructans by Kluyveromyces marxianus yeasts for bioethanol and tequila production.

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Flores, Jose-Axel; Gschaedler, Anne; Amaya-Delgado, Lorena; Herrera-López, Enrique J; Arellano, Melchor; Arrizon, Javier

2013-10-01

Agave tequilana fructans (ATF) constitute a substrate for bioethanol and tequila industries. As Kluyveromyces marxianus produces specific fructanases for ATF hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. In this work, fifteen K. marxianus yeasts were evaluated to develop inoculums with fructanase activity on ATF. These inoculums were added to an ATF medium for simultaneous saccharification and fermentation. All the yeasts, showed exo-fructanhydrolase activity with different substrate specificities. The yeast with highest fructanase activity in the inoculums showed the lowest ethanol production level (20 g/l). Five K. marxianus strains were the most suitable for the simultaneous saccharification and fermentation of ATF. The volatile compounds composition was evaluated at the end of fermentation, and a high diversity was observed between yeasts, nevertheless all of them produced high levels of isobutyl alcohol. The simultaneous saccharification and fermentation of ATF with K. marxianus strains has potential for industrial application. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methane production from acid hydrolysates of Agave tequilana bagasse: evaluation of hydrolysis conditions and methane yield.

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Arreola-Vargas, Jorge; Ojeda-Castillo, Valeria; Snell-Castro, Raúl; Corona-González, Rosa Isela; Alatriste-Mondragón, Felipe; Méndez-Acosta, Hugo O

2015-04-01

Evaluation of diluted acid hydrolysis for sugar extraction from cooked and uncooked Agave tequilana bagasse and feasibility of using the hydrolysates as substrate for methane production, with and without nutrient addition, in anaerobic sequencing batch reactors (AnSBR) were studied. Results showed that the hydrolysis over the cooked bagasse was more effective for sugar extraction at the studied conditions. Total sugars concentration in the cooked and uncooked bagasse hydrolysates were 27.9 g/L and 18.7 g/L, respectively. However, 5-hydroxymethylfurfural was detected in the cooked bagasse hydrolysate, and therefore, the uncooked bagasse hydrolysate was selected as substrate for methane production. Interestingly, results showed that the AnSBR operated without nutrient addition obtained a constant methane production (0.26 L CH4/g COD), whereas the AnSBR operated with nutrient addition presented a gradual methane suppression. Molecular analyses suggested that methane suppression in the experiment with nutrient addition was due to a negative effect over the archaeal/bacterial ratio. Copyright © 2015. Published by Elsevier Ltd.

[Description of Melolonthidae (Coleoptera) third instar larvae associated to Agave tequilana var. Azul and their population fluctuation in Jalisco, Mexico].

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García, Gabriel L; Ortega-Arenas, Laura; Hernández, Héctor G; García, Agustín A; Nápoles, Jesús R; Cortés, Ramón R

2009-01-01

Third instars of white grubs of six species associated to agave tequilero in Jalisco, México were described from 1,145 specimens collected from soil samples from September 2006 to August 2007, in the municipalities of Ixtlahuacán del Río, Tepatitlán de Morelos and San Juan de Escobedo, Jalisco, México. Diagnostic characters were illustrated and a key was also included. Cyclocephala comata (Bates) was the most abundant species (63.2%), followed by Phyllophaga ravida (Blanchard) (21.9%), Phyllophaga polyphylla (Bates) (9.4%), Phyllophaga misteca (Bates) (4.1%), Strategus aloeus (L.) (1.1%) and Anomala hoepfneri (Bates) (0.3%). Phyllophaga ravida and A. hoepfneri are reported for the first time on the agave plant and the latter is a new record for the State of Jalisco. All Melolonthidae species showed a marked seasonality with lower number of larvae in June 2007 and high number in August 2007, which is associated with the region's rainy season and the agave plant age, respectively.

Construction and characterization of a partial binary bacterial ...

African Journals Online (AJOL)

The structure and organization of the genome of Agave is still unknown. To provide a genomic tool for searching sequences of the genus, we built and characterized a binary (BIBAC2) genomic library of Agave tequilana Weber var. azul. Clones of the library had an average insert size of 170 Kb. The frequency of inserts with ...

Detection of bacterial infection of agave plants by laser-induced fluorescence

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Cervantes-Martinez, Jesus; Flores-Hernandez, Ricardo; Rodriguez-Garay, Benjamin; Santacruz-Ruvalcaba, Fernando

2002-05-01

Greenhouse-grown plants of Agave tequilana Weber var. azul were inoculated with Erwinia carotovora, the causal agent of stem soft rot. We investigated the laser-induced fluorescence (LIF) of agave plants to determine whether LIF can be used as a noninvasive sensing tool for pathological studies. The LIF technique was also investigated as a means of detecting the effect of the polyamine biosynthesis inhibitor beta-hydroxyethylhydrazine as a bactericide against the pathogenic bacterium Erwinia carotovora. A He-Ne laser at 632.8 nm was used as the excitation source, and in vivo fluorescence emission spectra were recorded in the 660-790-range. Fluorescence maxima were at 690 and 740 nm. The infected plants that were untreated with the bactericide showed a definite increase in fluorescence intensity at both maxima within the first three days after infection. Beginning on the fifth day, a steady decrease in fluorescence intensity was observed, with a greater effect at 740 than at 690 nm. After 30 days there was no fluorescence. The infected plants that had been treated with the bactericide showed no significant change in fluorescence compared with that of the uninfected plants. The ratio of fluorescence intensities was determined to be F 690 nm/F 740 nm for all treatments. These studies indicate that LIF measurements of agave plants may be used for the early detection of certain types of disease and for determining the effect of a bactericide on bacteria. The results also showed that fluorescence intensity ratios can be used as a reliable indicator of the progress of disease.

New insights into plant glycoside hydrolase family 32 in Agave species.

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Avila de Dios, Emmanuel; Gomez Vargas, Alan D; Damián Santos, Maura L; Simpson, June

2015-01-01

In order to optimize the use of agaves for commercial applications, an understanding of fructan metabolism in these species at the molecular and genetic level is essential. Based on transcriptome data, this report describes the identification and molecular characterization of cDNAs and deduced amino acid sequences for genes encoding fructosyltransferases, invertases and fructan exohydrolases (FEH) (enzymes belonging to plant glycoside hydrolase family 32) from four different agave species (A. tequilana, A. deserti, A. victoriae-reginae, and A. striata). Conserved amino acid sequences and a hypervariable domain allowed classification of distinct isoforms for each enzyme type. Notably however neither 1-FFT nor 6-SFT encoding cDNAs were identified. In silico analysis revealed that distinct isoforms for certain enzymes found in a single species, showed different levels and tissue specific patterns of expression whereas in other cases expression patterns were conserved both within the species and between different species. Relatively high levels of in silico expression for specific isoforms of both invertases and fructosyltransferases were observed in floral tissues in comparison to vegetative tissues such as leaves and stems and this pattern was confirmed by Quantitative Real Time PCR using RNA obtained from floral and leaf tissue of A. tequilana. Thin layer chromatography confirmed the presence of fructans with degree of polymerization (DP) greater than DP three in both immature buds and fully opened flowers also obtained from A. tequilana.

Morphological features of different polyploids for adaptation and molecular characterization of CC-NBS-LRR and LEA gene families in Agave L.

Science.gov (United States)

Tamayo-Ordóñez, M C; Rodriguez-Zapata, L C; Narváez-Zapata, J A; Tamayo-Ordóñez, Y J; Ayil-Gutiérrez, B A; Barredo-Pool, F; Sánchez-Teyer, L F

2016-05-20

Polyploidy has been widely described in many Agave L. species, but its influence on environmental response to stress is still unknown. With the objective of knowing the morphological adaptations and regulation responses of genes related to biotic (LEA) and abiotic (NBS-LRR) stress in species of Agave with different levels of ploidy, and how these factors contribute to major response of Agave against environmental stresses, we analyzed 16 morphological trials on five accessions of three species (Agave tequilana Weber, Agave angustifolia Haw. and Agave fourcroydes Lem.) with different ploidy levels (2n=2x=60 2n=3x=90, 2n=5x=150, 2n=6x=180) and evaluated the expression of NBS-LRR and LEA genes regulated by biotic and abiotic stress. It was possible to associate some morphological traits (spines, nuclei, and stomata) to ploidy level. The genetic characterization of stress-related genes NBS-LRR induced by pathogenic infection and LEA by heat or saline stresses indicated that amino acid sequence analysis in these genes showed more substitutions in higher ploidy level accessions of A. fourcroydes Lem. 'Sac Ki' (2n=5x=150) and A. angustifolia Haw. 'Chelem Ki' (2n=6x=180), and a higher LEA and NBS-LRR representativeness when compared to their diploid and triploid counterparts. In all studied Agave accessions expression of LEA and NBS-LRR genes was induced by saline or heat stresses or by infection with Erwinia carotovora, respectively. The transcriptional activation was also higher in A. angustifolia Haw. 'Chelem Ki' (2n=6x=180) and A. fourcroydes 'Sac Ki' (2n=5x=150) than in their diploid and triploid counterparts, which suggests higher adaptation to stress. Finally, the diploid accession A. tequilana Weber 'Azul' showed a differentiated genetic profile relative to other Agave accessions. The differences include similar or higher genetic representativeness and transcript accumulation of LEA and NBS-LRR genes than in polyploid (2n=5x=150 and 2n=6x=180) Agave accessions

Contextualización socioambiental del agave en Tonaya, Jalisco, México

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Francia Elizabeth Rodríguez Contreras

2017-07-01

Full Text Available In Tonaya, the Agave angustifolia Haw has been cultivated since 1845, but today has been replaced almost entirely by the Agave tequilana Weber. This replacement and the increase in the demand for agave liquor caused environmental damages. The historical context and the socio-environmental effects generated by the agave distiller industry are described in this article, and the role played by the government institutions is analyzed, a study on the region that was nonexistent until today. Information from bibliographic archives and from interviews to key actors, using the snowball technique, was obtained. Moreover, the effects on biodiversity and water quality by the dumping of liquid waste or vinasse into the Tuxcacuesco river were examined. Decisions were made reducing environmental pollution; however, many of these actions have been abandoned, putting at risk again the water system’s integrity and what it represents.

Physical-Chemical and non-linear rheological properties of aqueous solutions of agave fructans

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Jamné A. Ponce S.

2008-01-01

Full Text Available Los fructanos son carbohidratos de reserva formados por unidades fructofuranosil con enlaces tipo B principalmente, que se encuentran presentes en diversas variedades de plantas. Los fructanos empleados en el presente estudio, fueron obtenidos mediante una extracción acuosa a partir de piñas maduras de Agave tequilana Weber var. azul. Se sabe que las moléculas de fructanos derivados del agave, poseen una configuración ramificada a diferencia de la configuración lineal presente en la inulina comercial (derivada de la Cichorium intybus, lo que les podría otorgar diferentes propiedades y aplicaciones tecnológicas. La composición de los fructanos de agave obtenidos en éste estudio, mostró una mezcla con diferentes tamaños y pesos moleculares promedio de 3,182 Da así como un grado de polimerización promedio de 18. Las soluciones acuosas de fructanos de agave fueron preparadas (de 5-90% p/p y sometidas a una serie de pruebas como pH y densidad a 30, 40, 50 y 60 °C; adicionalmente, la conductividad y el tamaño de partícula (QLS por sus siglas en inglés fueron analizadas a temperatura ambiente. Los resultados de las pruebas mencionadas anteriormente sugieren que, los fructanos derivados del agave pueden formar agregados a concentraciones superiores al 28% p/p. Por otro lado, las mediciones reológicas no lineales de las soluciones acuosas de fructanos de agave se llevaron a cabo a 30, 40, 50 y 60 °C (previa estabilización de la muestra a la temperatura de medición mostrando que presentan comportamientos Newtonianos excepto aquellas a 80 y 90 % p/p, donde comportamientos de adelgazamiento y espesamiento al corte fueron observados. Finalmente, los resultados reológicos aportan valiosa información sobre la formación de agregados en las soluciones acuosas de fructanos de agave en el intervalo de concentraciones de 30 a 70 % p/p, por medio de mediciones de velocidad de corte en estado estacionario efectuadas a 30, 40, 50 y 60°C.

Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

Science.gov (United States)

Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

2016-04-01

The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. Copyright © 2016. Published by Elsevier Ltd.

New insights into plant glycoside hydrolase family 32 in Agave species

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Emmanuel eAvila-de Dios

2015-08-01

Full Text Available In order to optimize the use of agaves for commercial applications, an understanding of fructan metabolism in these species at the molecular and genetic level is essential. Based on transcriptome data, this report describes the identification and molecular characterization of cDNAs and deduced amino acid sequences for genes encoding fructosyltransferases, invertases and fructan exohydrolases (enzymes belonging to plant glycoside hydrolase family 32 from four different agave species (A. tequilana, A. deserti, A. victoriae-reginae and A. striata. Conserved amino acid sequences and a hypervariable domain allowed classification of distinct isoforms for each enzyme type. Notably however neither 1-FFT nor 6-SFT encoding cDNAs were identified. In silico analysis revealed that distinct isoforms for certain enzymes found in a single species, showed different levels and tissue specific patterns of expression whereas in other cases expression patterns were conserved both within the species and between different species. Relatively high levels of in silico expression for specific isoforms of both invertases and fructosyltransferases were observed in floral tissues in comparison to vegetative tissues such as leaves and stems and this pattern was confirmed by Quantitative Real Time PCR using RNA obtained from floral and leaf tissue of A. tequilana. Thin layer chromatography confirmed the presence of fructans with degree of polymerization (DP greater than DP three in both immature buds and fully opened flowers also obtained from A. tequilana.

Application of agave subproducts for production of microbial inulinases

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Huerta Alcocer, S.A.

2014-07-01

Full Text Available Mexico is the center of origin of the genus Agave spp. with 159 endemic species, 75 % of all known species. The main use of these plants is in the production of alcoholic beverages, mainly tequila, which is obtained from the “pines” of A. tequilana Weber var. Azul. During tequila production, a huge amount of waste is produced, including leaves that are not used. Main compounds found in these subproducts are polysaccharides, specifically inulin. Current review focuses on the use of these agricultural wastes to obtain inulinase production, and in the production of high fructose syrup using these enzymes in these wastes. Currently, high fructose syrups, especially oligosaccharides, have prompted much interest for their benefits to health due to its low glycemic index and their function as prebiotic in the intestinal flora. The main microorganisms involved with inulinases production belong to the genera Aspergillus and Kluyveromyces. The latter is preferred in the industry due to its high growth rate, high temperature tolerance (52 °C and by having the GRAS (Generally Recognized As Safe status. This review emphasizes on the advances achieved in the production of inulinases by yeast K. marxianus.

African Journal of Biotechnology - Vol 11, No 93 (2012)

African Journals Online (AJOL)

Construction and characterization of a partial binary bacterial artificial chromosome (BIBAC) of Agave tequilana var. azul (2X) and its application for gene identification · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M Tamayo-Ordoñez, LC Rodríguez-Zapata, ...

In vitro evaluation of the fermentation properties and potential prebiotic activity of Agave fructans.

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Gomez, E; Tuohy, K M; Gibson, G R; Klinder, A; Costabile, A

2010-06-01

This study was carried out to evaluate in vitro the fermentation properties and the potential prebiotic activity of Agave-fructans extracted from Agave tequilana (Predilife). Five different commercial prebiotics were compared using 24-h pH-controlled anaerobic batch cultures inoculated with human faecal slurries. Measurement of prebiotic efficacy was obtained by comparing bacterial changes, and the production of short-chain fatty acids (SCFA) was also determined. Effects upon major groups of the microbiota were monitored over 24 h incubations by fluorescence in situ hybridization. SCFA were measured by HPLC. Fermentation of the Agave fructans (Predilife) resulted in a large increase in numbers of bifidobacteria and lactobacilli. Under the in vitro conditions used, this study has shown the differential impact of Predilife on the microbial ecology of the human gut. This is the first study reporting of a potential prebiotic mode of activity for Agave fructans investigated which significantly increased populations of bifidobacteria and lactobacilli compared to cellulose used as a control.

Fructan metabolism in A. tequilana Weber Blue variety along its developmental cycle in the field.

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Mellado-Mojica, Erika; López, Mercedes G

2012-11-28

Fructan, as reserve carbohydrate, supplies energy needs during vegetative development, thereby exhibiting variations in its content and composition. Fructan metabolism in Agave tequilana Blue variety from 2- to 7-year-old plants was analyzed in this work. Soluble carbohydrates were determined at all ages. Fructan (328-711 mg/g), sucrose (14-39 mg/g), fructose (11-20 mg/g), glucose (4-14 mg/g), and starch (0.58-4.98 mg/g) were the most abundant carbohydrates. Thin-layer chromatography exhibited that 2-5-year-old plants mainly stored fructooligosaccharides, while 6-7-year-old plants mainly contained long-chain fructans. The fructan degree of polymerization (DP) increased from 6 to 23 throughout plant development. The 7-year-old plants mainly stored highly branched agavins. Partially methylated alditol acetate analyzed by gas chromatography-mass spectrometry reveals that fructan molecular structures became more complex with plant age. For the first time, we report the presence of a large number of DP3 (seven forms), DP4 (eight forms), and DP5 (six forms) isomers for agave fructans. Overall, fructan metabolism in A. tequilana displays changes in its soluble carbohydrates, DP, type, and fructan structures stored, along its developmental cycle in the field.

Genetic and morphological contrasts between wild and anthropogenic populations of Agave parryi var. huachucensis in south-eastern Arizona.

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Parker, Kathleen C; Trapnell, Dorset W; Hamrick, J L; Hodgson, Wendy C

2014-05-01

At least seven species of Agave, including A. parryi, were cultivated prehistorically in Arizona, serving as important sources of food and fibre. Many relict populations from ancient cultivation remain in the modern landscape, offering a unique opportunity to study pre-Columbian plant manipulation practices. This study examined genetic and morphological variation in six A. p. var. huachucensis populations of unknown origin to compare them with previous work on A. parryi populations of known origin, to infer their cultivation history and to determine whether artificial selection is evident in populations potentially managed by early agriculturalists. Six A. p. var. huachucensis and 17 A. parryi populations were sampled, and morphometric, allozyme and microsatellite data were used to compare morphology and genetic structure in purportedly anthropogenic and wild populations, as well as in the two taxa. Analysis of molecular variance and Bayesian clustering were performed to partition variation associated with taxonomic identity and hypothesized evolutionary history, to highlight patterns of similarity among populations and to identify potential wild sources for the planting stock. A p. var. huachucensis and A. parryi populations differed significantly both morphologically and genetically. Like A. parryi, wild A. p. var. huachucensis populations were more genetically diverse than the inferred anthropogenic populations, with greater expected heterozygosity, percentage of polymorphic loci and number of alleles. Inferred anthropogenic populations exhibited many traits indicative of past active cultivation: greater morphological uniformity, fixed heterozygosity for several loci (non-existent in wild populations), fewer multilocus genotypes and strong differentiation among populations. Where archaeological information is lacking, the genetic signature of many Agave populations in Arizona can be used to infer their evolutionary history and to identify potentially fruitful

Identification, classification, and discrimination of agave syrups from natural sweeteners by infrared spectroscopy and HPAEC-PAD.

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Mellado-Mojica, Erika; López, Mercedes G

2015-01-15

Agave syrups are gaining popularity as new natural sweeteners. Identification, classification and discrimination by infrared spectroscopy coupled to chemometrics (NIR-MIR-SIMCA-PCA) and HPAEC-PAD of agave syrups from natural sweeteners were achieved. MIR-SIMCA-PCA allowed us to classify the natural sweeteners according to their natural source. Natural syrups exhibited differences in the MIR spectra region 1500-900 cm(-1). The agave syrups displayed strong absorption in the MIR spectra region 1061-1,063 cm(-1), in agreement with their high fructose content. Additionally, MIR-SIMCA-PCA allowed us to differentiate among syrups from different Agave species (Agavetequilana and Agavesalmiana). Thin-layer chromatography and HPAEC-PAD revealed glucose, fructose, and sucrose as the principal carbohydrates in all of the syrups. Oligosaccharide profiles showed that A. tequilana syrups are mainly composed of fructose (>60%) and fructooligosaccharides, while A. salmiana syrups contain more sucrose (28-32%). We conclude that MIR-SIMCA-PCA and HPAEC-PAD can be used to unequivocally identify and classified agave syrups. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Anti-inflammatory activity of different agave plants and the compound cantalasaponin-1.

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Monterrosas-Brisson, Nayeli; Ocampo, Martha L Arenas; Jiménez-Ferrer, Enrique; Jiménez-Aparicio, Antonio R; Zamilpa, Alejandro; Gonzalez-Cortazar, Manases; Tortoriello, Jaime; Herrera-Ruiz, Maribel

2013-07-10

Species of the agave genus, such as Agave tequilana, Agave angustifolia and Agave americana are used in Mexican traditional medicine to treat inflammation-associated conditions. These plants' leaves contain saponin compounds which show anti-inflammatory properties in different models. The goal of this investigation was to evaluate the anti-inflammatory capacity of these plants, identify which is the most active, and isolate the active compound by a bio-directed fractionation using the ear edema induced in mice with 12-O-tetradecanoylphorbol-13-acetate (TPA) technique. A dose of 6 mg/ear of acetone extract from the three agave species induced anti-inflammatory effects, however, the one from A. americana proved to be the most active. Different fractions of this species showed biological activity. Finally the F5 fraction at 2.0 mg/ear induced an inhibition of 85.6%. We identified one compound in this fraction as (25R)-5α-spirostan-3β,6α,23α-triol-3,6-di-O-β-D-glucopyranoside (cantalasaponin-1) through 1H- and 13C-NMR spectral analysis and two dimensional experiments like DEPT NMR, COSY, HSQC and HMBC. This steroidal glycoside showed a dose dependent effect of up to 90% of ear edema inhibition at the highest dose of 1.5 mg/ear.

Overexpression of smORF YNR034W-A/EGO4 in Saccharomyces cerevisiae increases the fermentative efficiency of Agave tequilana Weber must.

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Vargas-Maya, Naurú Idalia; González-Hernández, Gloria Angélica; Padilla-Guerrero, Israel Enrique; Torres-Guzmán, Juan Carlos

2017-01-01

Fermentative processes are widely used to produce food, beverages and biofuels. Saccharomyces cerevisiae is an efficient ethanol-producing microorganism. However, a concentration of high ethanol and other metabolites can affect yeast viability and decrease the ethanol yield. Many studies have focused on improving the fermentative efficiency, mostly through the genetic engineering of genes that have a direct impact on specific metabolic pathways. In the present study, we characterized a small open reading frame encoding a protein with an unknown function and biological role termed YNR034W-A. We analyzed the expression profile of the YNR034W-A gene during growth and glucose treatment, finding that it is expressed during the diauxic shift and stationary phase and is negatively regulated by glucose. We overexpressed the YNR034W-A gene in the BY4741 laboratory strain and a wild-type yeast strain (AR5) isolated during the Tequila fermentation process. Transformant derivatives of the AR5 strain showed an improved fermentative efficiency during fermentation of Agave tequilana Weber juice. We suggest that the improved fermentative efficiency is the result of a higher stress tolerance response in the YNR034W-A overexpressing transformant.

Efficient chemical and enzymatic saccharification of the lignocellulosic residue from Agave tequilana bagasse to produce ethanol by Pichia caribbica.

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Saucedo-Luna, Jaime; Castro-Montoya, Agustin Jaime; Martinez-Pacheco, Mauro Manuel; Sosa-Aguirre, Carlos Ruben; Campos-Garcia, Jesus

2011-06-01

Bagasse of Agave tequilana (BAT) is the residual lignocellulosic waste that remains from tequila production. In this study we characterized the chemical composition of BAT, which was further saccharified and fermented to produce ethanol. BAT was constituted by cellulose (42%), hemicellulose (20%), lignin (15%), and other (23%). Saccharification of BAT was carried out at 147 °C with 2% sulfuric acid for 15 min, yielding 25.8 g/l of fermentable sugars, corresponding to 36.1% of saccharificable material (cellulose and hemicellulose contents, w/w). The remaining lignocellulosic material was further hydrolyzed by commercial enzymes, ~8.2% of BAT load was incubated for 72 h at 40 °C rendering 41 g/l of fermentable sugars corresponding to 73.6% of the saccharificable material (w/w). Mathematic surface response analysis of the acid and enzymatic BAT hydrolysis was used for process optimization. The results showed a satisfactory correlation (R (2) = 0.90) between the obtained and predicted responses. The native yeast Pichia caribbica UM-5 was used to ferment sugar liquors from both acid and enzymatic hydrolysis to ethanol yielding 50 and 87%, respectively. The final optimized process generated 8.99 g ethanol/50 g of BAT, corresponding to an overall 56.75% of theoretical ethanol (w/w). Thus, BAT may be employed as a lignocellulosic raw material for bioethanol production and can contribute to BAT residue elimination from environment.

Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

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Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

2016-01-01

Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions. No claim to US Government works. New Phytologist © 2015 New Phytologist Trust.

Agricultural waste from the tequila industry as substrate for the production of commercially important enzymes.

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Huitron, C; Perez, R; Sanchez, A E; Lappe, P; Rocha Zavaleta, L

2008-01-01

Approximately 1 million tons of Agave tequilana plants are processed annually by the Mexican Tequila industry generating vast amounts of agricultural waste. The aim of this study was to investigate the potential use of Agave tequilana waste as substrate for the production of commercially important enzymes. Two strains of Aspergillus niger (CH-A-2010 and CH-A-2016), isolated from agave fields, were found to grow and propagate in submerged cultures using Agave tequilana waste as substrate. Isolates showed simultaneous extracellular inulinase, xylanase, pectinase, and cellulase activities. Aspergillus CH-A-2010 showed the highest production of inulinase activity (1.48 U/ml), whereas Aspergillus niger CH-A-2016 produced the highest xylanase (1.52 U/ml) and endo-pectinase (2.7U/ml) activities. In both cases production of enzyme activities was significantly higher on Agave tequilana waste than that observed on lemon peel and specific polymeric carbohydrates. Enzymatic hydrolysis of raw A. tequilana stems and leaves, by enzymes secreted by the isolates yielded maximum concentrations of reducing sugars of 28.2 g/l, and 9.9 g/l respectively. In conclusion, Agave tequilana waste can be utilized as substrate for the production of important biotechnological enzymes.

Anti-Inflammatory Activity of Different Agave Plants and the Compound Cantalasaponin-1

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Jaime Tortoriello

2013-07-01

Full Text Available Species of the agave genus, such as Agave tequilana, Agave angustifolia and Agave americana are used in Mexican traditional medicine to treat inflammation-associated conditions. These plants’ leaves contain saponin compounds which show anti-inflammatory properties in different models. The goal of this investigation was to evaluate the anti-inflammatory capacity of these plants, identify which is the most active, and isolate the active compound by a bio-directed fractionation using the ear edema induced in mice with 12-O-tetradecanoylphorbol-13-acetate (TPA technique. A dose of 6 mg/ear of acetone extract from the three agave species induced anti-inflammatory effects, however, the one from A. americana proved to be the most active. Different fractions of this species showed biological activity. Finally the F5 fraction at 2.0 mg/ear induced an inhibition of 85.6%. We identified one compound in this fraction as (25R-5α-spirostan-3β,6α,23α-triol-3,6-di-O-β-D-glucopyranoside (cantalasaponin-1 through 1H- and 13C-NMR spectral analysis and two dimensional experiments like DEPT NMR, COSY, HSQC and HMBC. This steroidal glycoside showed a dose dependent effect of up to 90% of ear edema inhibition at the highest dose of 1.5 mg/ear.

Utilization of by-products from the tequila industry. Part 2: Potential value of Agave tequilana Weber azul leaves.

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Iñiguez-Covarrubias, G; Díaz-Teres, R; Sanjuan-Dueñas, R; Anzaldo-Hernández, J; Rowell, R M

2001-04-01

The leaves of the agave plant are left in the field after harvesting the heads for tequila production. Different types of agave leaves were isolated, classified, and their content in the total plant determined. The usable fractions were collected and their properties determined. Of the total wet weight of the agave plant, 54% corresponds to the agave head, 32% corresponds to materials which could be usable for sugar and fiber production which leaves 14% of the wet plant without apparent utility. The fractions with higher total reducing sugars (TRS) content were the fresh fraction of partially dry leaves stuck to the head and the leaf bases with a TRS content of 16.1% and 13.1%, respectively. The highest TRS concentration (16-28%) is in the agave head which is used for tequila production. The leaves are 90-120 cm long and 8-12 cm wide and contain fiber bundles that are 23-52 cm long and 0.6-13 mm wide. The ultimate fiber length is approximately 1.6 mm with an average width of 25 microns. There are several types of leaf fibers that can be utilized depending on what part of the plant they come from and what product is desired. Agave leaf fibers were pulped using a soda pulping process and the pulp was hand formed into test sheets. Test sheets made from pulped agave leaf fibers had a breaking length comparable to paper made from both pine and eucalyptus fibers, but the tear index and burst index were lower than the other two papers.

Physical mapping of 5S and 18S ribosomal DNA in three species of Agave (Asparagales, Asparagaceae).

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Gomez-Rodriguez, Victor Manuel; Rodriguez-Garay, Benjamin; Palomino, Guadalupe; Martínez, Javier; Barba-Gonzalez, Rodrigo

2013-01-01

Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country's economy. Cytogenetic analysis was carried out in Agave tequilana Weber, 1902 'Azul', Agave cupreata Trelease et Berger, 1915 and Agave angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH) was used for physical mapping of 5S and 18S ribosomal DNA (rDNA). All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.

Agave azul y el desarrollo sustentable en la cuenca baja del río Ayuquila, Costa Sur de Jalisco (1994-2004

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Peter R.W. Gerritsen

2011-01-01

Full Text Available El agave azul (Agave tequilana Weber es un cultivo nuevo para la cuenca del río Ayuquila en la Costa Sur de Jalisco, y es importante para su progreso agropecuario. Sin embargo, se observan efectos socioambientales negativos. Desde 2003 se han estudiado las condiciones del cultivo y su expansión, así como alternativas posibles. Los resultados muestran un crecimiento acelerado desde su introducción, a mitad de la década de 1990. Se destaca una concentración de propietarios privados y a través de contratos. Si bien sembrar esta planta puede ser redituable, las tendencias cíclicas de sobreproducción y escasez han originado una falta de incentivos para hacerlo y un deterioro de la capacidad productiva. Se discuten las perspectivas del avance agropecuario basado en el cultivo del agave azul, y se ofrecen algunas recomendaciones para fomentar la sustentabilidad de su sistema de producción comercial.

Production of fructanase by a wild strain of Saccharomyces cerevisiae on tequila agave fructan.

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Corona-González, R I; Pelayo-Ortiz, C; Jacques, G; Guatemala, G; Arriola, E; Arias, J A; Toriz, G

2015-01-01

A new wild strain of Saccharomyces cerevisiae (CF3) isolated from tequila must was evaluated for production of fructanase on Agave tequilana Weber fructan (FT). Fructanase activity (F) was assessed by a 3(3) factorial design (substrate, temperature and pH). High enzymatic activity (31.1 U/ml) was found at 30 °C, pH 5, using FT (10 g/l) as substrate. The effect of initial substrate concentration on F (FT0, 5.7-66 g/l) was studied and it was found that F was highest (44.8 U/ml) at FT0 25 g/l. A 2(2) factorial experimental design with five central points was utilized to study the effect of stirring and aeration on fructanase activity; stirring exhibited a stronger effect on F. The ratio fructanase to invertase (F/S) was 0.57, which confirms that the enzymes are fructanase. Crude fructanase reached high substrate hydrolysis (48 wt%) in 10 h. It is shown that S. cerevisiae CF3 was able to produce large amounts of fructanase by growing it on fructan from A. tequilana.

In-vivo electrochemical monitoring of H2O2 production induced by root-inoculated endophytic bacteria in Agave tequilana leaves.

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Lima, Alex S; Prieto, Kátia R; Santos, Carla S; Paula Valerio, Hellen; Garcia-Ochoa, Evelyn Y; Huerta-Robles, Aurora; Beltran-Garcia, Miguel J; Di Mascio, Paolo; Bertotti, Mauro

2018-01-15

A dual-function platinum disc microelectrode sensor was used for in-situ monitoring of H 2 O 2 produced in A. tequilana leaves after inoculation of their endophytic bacteria (Enterobacter cloacae). Voltammetric experiments were carried out from 0.0 to -1.0V, a potential range where H 2 O 2 is electrochemically reduced. A needle was used to create a small cavity in the upper epidermis of A. tequilana leaves, where the fabricated electrochemical sensor was inserted by using a manual three-dimensional micropositioner. Control experiments were performed with untreated plants and the obtained electrochemical results clearly proved the formation of H 2 O 2 in the leaves of plants 3h after the E. cloacae inoculation, according to a mechanism involving endogenous signaling pathways. In order to compare the sensitivity of the microelectrode sensor, the presence of H 2 O 2 was detected in the root hairs by 3,3-diaminobenzidine (DAB) stain 72h after bacterial inoculation. In-situ pH measurements were also carried out with a gold disc microelectrode modified with a film of iridium oxide and lower pH values were found in A. tequilana leaves treated with bacteria, which may indicate the plant produces acidic substances by biosynthesis of secondary metabolites. This microsensor could be an advantageous tool for further studies on the understanding of the mechanism of H 2 O 2 production during the plant-endophyte interaction. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of five typical agave plants used to produce mezcal through their simple lipid composition analysis by gas chromatography.

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Martínez-Aguilar, Juan Fco; Peña-Alvarez, Araceli

2009-03-11

Five agave plants typically used in Mexico for making mezcal in places included in the Denomination of Origin (Mexican federal law that establishes the territory within which mezcal can be produced) of this spirit were analyzed: Agave salmiana ssp. crassispina, A. salmiana var. salmiana, Agave angustifolia, Agave cupreata, and Agave karwinskii. Fatty acid and total simple lipid profiles of the mature heads of each plant were determined by means of a modified Bligh-Dyer extraction and gas chromatography. Sixteen fatty acids were identified, from capric to lignoceric, ranging from 0.40 to 459 microg/g of agave. Identified lipids include free fatty acids, beta-sitosterol, and groups of mono-, di-, and triacylglycerols, their total concentration ranging from 459 to 992 microg/g of agave. Multivariate analyses performed on the fatty acid profiles showed a close similarity between A. cupreata and A. angustifolia. This fact can be ascribed to the taxa themselves or differences in growing conditions, an issue that is still to be explored. These results help to characterize the agaves chemically and can serve to relate the composition of mezcals from various states of Mexico with the corresponding raw material.

Raphide crystal structure in agave tequilana determined by x-ray originating from synchrotron radiation

International Nuclear Information System (INIS)

Tadokoro, Makoto; Ozawa, Yoshiki; Mitsumi, Minoru; Toriumi, Kohshiro; Ogura, Tetsuya

2005-01-01

The first single crystal structure of small natural raphides in an agave plant is completely determined using an intense X-ray originating from a synchrotron radiation. The SEM image shows that the tip of the crystal is approximately hundreds of nanometer in width sharply grow to stick to the tissue of herbivorous vermin. Furthermore, the crystal develops cracks that propagate at an inclination of approximately 45deg towards the direction of crystal growth such that the crystal easily splits into small pieces in the tissue. (author)

variedad azul

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R. I. Corona González

2005-01-01

Full Text Available En este trabajo se muestra un estudio del efecto del pH, la temperatura y la concentración de polifructosas de Agave tequilana weber variedad azul sobre la producción de inulinasas, con una cepa de Saccharomyces sp. en un reactor de 16 litros. Las condiciones óptimas del proceso se obtuvieron al aplicar un diseño factorial 23 en el cual temperatura, pH y concentración de azúcares de Agave tequilana se probaron con dos niveles 15 y 30°C, 4 y 5.5 y 20 y 30 g/L respectivamente. Las condiciones con las que se alcanzó la concentración más alta de inulinasas (240.6 U/ml fueron: temperatura 30°C, pH 5.5 y 30 g/L de polifructosas de Agave tequilana

Pulping and papermaking properties of the leaf fiber and fibrous residue from Agave tequilana

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Kurita, T.; Mitsuhashi, S.; Kanetsuna, H.; Iguchi, M.; Shirota, T.; Trujillo, J.J.; Herrera, T.

1981-01-01

The leaves and fibrous residue of A. tequilana had fibriles with parallel orientation and helical arrangement to the fiber axis and contained fibers in average length and width of 1.7 mm and 10.3 mu m and 0.8 mm and 25.5 mu m, respectively. The cell wall in leaves was thicker and narrower than those in fibrous residue, and leaves contained cellulose and lignin lower than fibrous residue did. Alkali sulfite cooking of leaves gave pulp, the yield of which was lower than that from fibrous residue. The H/sub 2/On retention and bulk density of leaf pulps increased rapidly on beating suggesting that an internal fibrillation in pulp occurs easily during beating. The breaking length and burst and tear factors of paper from leaf pulp were higher than those from fibrous residue.

Extraction and characterization of Agave salmiana Otto ex Salm-Dyck fructans

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César I. Godínez-Hernández

2016-01-01

Full Text Available Los fructanos son polímeros de fructosa con grandes aplicaciones en la industria de alimentos funcionales. Aunque los fructanos de Agave angustifolia spp. tequilana ya se producen industrialmente y comienzan a tener demanda en EE. UU., para su extracción se sigue utilizando la cabeza o piña de maguey (tallo y bases foliares con madurez variable, lo cual repercute en la calidad y en procesos que encarecen la producción. En este trabajo se describe un método alternativo para la extracción de fructanos de tallos de Agave salmiana, el cual es más simple y facilita la obtención de manera natural u orgánica. Se evaluaron los rendimientos absoluto y relativo del concentrado de fructanos (CF, referidos tanto al tallo como a la cabeza de maguey, así como su calidad mediante el análisis por cromatografía líquida de alta resolución (HPLC. El rendimiento de CF (95 % MS de materia seca del tallo fresco fue de 21 % y casi 80 % del tallo seco. El CF libre de humedad está compuesto por cerca de 80 % de fructanos y el resto por trisacáridos (cerca de 9.5 %, cenizas (5 %, sacarosa (1 % y sapogeninas (0.85 %; cantidades de glucosa y fructosa no fueron detectables (< 0.002 %.

Effects of Fructans from Mexican Agave in Newborns Fed with Infant Formula: A Randomized Controlled Trial

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Gabriel López-Velázquez

2015-10-01

Full Text Available Background: The importance of prebiotics consumption is increasing all over the world due to their beneficial effects on health. Production of better prebiotics from endemic plants raises possibilities to enhance nutritional effects in vulnerable population groups. Fructans derived from Agave Plant have demonstrated their safety and efficacy as prebiotics in animal models. Recently, the safety in humans of two fructans obtained from Agave tequilana (Metlin® and Metlos® was demonstrated. Methods: This study aimed to demonstrate the efficacy as prebiotics of Metlin® and Metlos® in newborns of a randomized, double blind, controlled trial with a pilot study design. Biological samples were taken at 20 ± 7 days, and three months of age from healthy babies. Outcomes of efficacy include impact on immune response, serum ferritin, C-reactive protein, bone metabolism, and gut bacteria changes. Results: There were differences statistically significant for the groups of infants fed only with infant formula and with formula enriched with Metlin® and Metlos®. Conclusions: Our results support the efficacy of Metlin® and Metlos® as prebiotics in humans, and stand the bases to recommend their consumption. Trial Registration: ClinicalTrials.gov, NCT 01251783.

Effects of Fructans from Mexican Agave in Newborns Fed with Infant Formula: A Randomized Controlled Trial.

Science.gov (United States)

López-Velázquez, Gabriel; Parra-Ortiz, Minerva; Mora, Ignacio De la Mora-De la; García-Torres, Itzhel; Enríquez-Flores, Sergio; Alcántara-Ortigoza, Miguel Angel; Angel, Ariadna González-Del; Velázquez-Aragón, José; Ortiz-Hernández, Rosario; Cruz-Rubio, José Manuel; Villa-Barragán, Pablo; Jiménez-Gutiérrez, Carlos; Gutiérrez-Castrellón, Pedro

2015-10-29

The importance of prebiotics consumption is increasing all over the world due to their beneficial effects on health. Production of better prebiotics from endemic plants raises possibilities to enhance nutritional effects in vulnerable population groups. Fructans derived from Agave Plant have demonstrated their safety and efficacy as prebiotics in animal models. Recently, the safety in humans of two fructans obtained from Agave tequilana (Metlin(®) and Metlos(®)) was demonstrated. This study aimed to demonstrate the efficacy as prebiotics of Metlin(®) and Metlos(®) in newborns of a randomized, double blind, controlled trial with a pilot study design. Biological samples were taken at 20 ± 7 days, and three months of age from healthy babies. Outcomes of efficacy include impact on immune response, serum ferritin, C-reactive protein, bone metabolism, and gut bacteria changes. There were differences statistically significant for the groups of infants fed only with infant formula and with formula enriched with Metlin(®) and Metlos(®). Our results support the efficacy of Metlin(®) and Metlos(®) as prebiotics in humans, and stand the bases to recommend their consumption. ClinicalTrials.gov, NCT 01251783.

Extracción de fibras de agave para elaborar papel y artesanías Extracción de fibras de agave para elaborar papel y artesanías

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Antonio Prieto Rodríguez

2012-02-01

Full Text Available Investigación aplicada para el aprovechamiento integral sustentable de vegetales nativos regionales, en la cual se extrajo fibra de seis especies de Agave (maguey; tres de hoja angosta (A. lechuguilla, A. angustifolia y A. tequilana y tres de hoja ancha (A. americana, A. salmiana y A. mapisaga, utilizando tres métodos; 1 inmersión en agua a cielo abierto, 2 fermentación con y sin “aguamiel”, y 3 cocción de pencas. Se evaluó: color, olor, suavidad, enguiche, facilidad de desfibración, y tiempo empleado. En conclusión, el tratamiento más práctico fue el cocimiento de pencas, aunque no el más económico y ecológico. Los resultados obtenidos hasta esta etapa indican que de cada especie analizada se puede obtener papel y que éste presenta características distintivas que lo hacen atractivo para diferentes usos artesanales. Particularmente, las especies que produjeron los tipos de papel de mayor calidad para la escritura y el dibujo fueron A. salmiana y A. mapisaga.   Applied research for the sustainable integral use of regional native plants, which was extracted fiber from six species of Agave (common name maguey, three narrow-leaved (A. lechuguilla, A. angustifolia and A. tequilana and three wide-leaved (A. americana, A. salmiana and A. mapisaga by using three methods: 1 cooking of pads, 2 fermentation with and without aguamiel (maguey sweet juice and 3 immersion in water open sky. By considering the variables color, odor, softness, enguiche, easiness of defibration and time spent. In conclusion, most practical treatment was the boiling of the fleshy leaves, but not the most economical and environmentally friendly one. The results got up to this stage indicate that paper can be obtained from each of the six species and that it shows characteristic features which make it attractive to be applied in various craft uses. In particular, the species pro­ducing the most paper with the best quality, i.e., for writing and drawing, were A

Effect of Agave americana and Agave salmiana Ripeness on Saponin Content from Aguamiel (Agave Sap).

Science.gov (United States)

Leal-Díaz, Ana María; Santos-Zea, Liliana; Martínez-Escobedo, Hilda Cecilia; Guajardo-Flores, Daniel; Gutiérrez-Uribe, Janet Alejandra; Serna-Saldivar, Sergio Othón

2015-04-22

Steroidal saponins have shown beneficial health effects. Agave spp. leaves and rhizomes are sources of these compounds, but their presence has not been reported in the aguamiel. Aguamiel is the sweet edible sap from mature agave, and its quality is influenced by the plant ripening stage. The purpose of this research was to identify and quantitate saponins in aguamiel from Agave americana and Agave salmiana at two ripening stages. Saponins and sapogenins were identified with HPLC/ESI-MS/TOF and quantitated with HPLC/ELSD. Results proved the presence of saponins derived from kammogenin, manogenin, gentrogenin, and hecogenin. The saponin content in aguamiel from immature A. salmiana was 2-fold higher (478.3 protodioscin equivalents (PE) μg/g aguamiel (DM)) compared with A. americana (179.0 PE μg/g aguamiel (DM)). In both species, saponin content decreased when plants reached sexual maturity. This should be considered before evaluating the effects of Agave spp. as a source of bioactive saponins.

Autohydrolysis pretreatment assessment in ethanol production from agave bagasse.

Science.gov (United States)

Rios-González, Leopoldo J; Morales-Martínez, Thelma K; Rodríguez-Flores, María F; Rodríguez-De la Garza, José A; Castillo-Quiroz, David; Castro-Montoya, Agustín J; Martinez, Alfredo

2017-10-01

The aim of the present work was to assess the autohydrolysis pretreatment of Agave tequilana bagasse for ethanol production. The pretreatment was conducted using a one-liter high pressure Parr reactor under different severity factors (SF) at a 1:6w/v ratio (solid:liquid) and 200rpm. The solids obtained under the selected autohydrolysis conditions were subjected to enzymatic hydrolysis with a commercial cellulase cocktail, and the enzymatic hydrolysate was fermented using Saccharomyces cerevisiae. The results obtained from the pretreatment process showed that the glucan content in the pretreated solid was mostly preserved, and an increase in the digestibility was observed for the case with a SF of 4.13 (190°C, 30min). Enzymatic hydrolysis of the pretreated solids showed a yield of 74.3%, with a glucose concentration of 126g/L, resulting in 65.26g/L of ethanol after 10h of fermentation, which represent a 98.4% conversion according to the theoretical ethanol yield value. Copyright © 2017 Elsevier Ltd. All rights reserved.

compuestos fenólicos

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Yolanda González García

2005-01-01

Full Text Available En este trabajo se presenta una revisión bibliográfica que tiene como objetivo identificar y analizar alternativas de aprovechamiento del bagazo de Agave tequilana Weber var. Azul. Se proponen dos líneas de investigación para obtener productos de valor agregado a partir de este residuo: 1utilización como fuente de carbono de bajo costo para la producción de biopolímeros y carbohidrasas, con bacterias celulolíticas del género Microbulbifer, Marinobacterium y Sagittula; 2obtención de compuestos fenólicos a partir de la lignina presente en sus fibras. Se concluye, que el bagazo de agave tequilero es un material viable para ser usado como substrato en procesos fermentativos, por lo que existen grandes oportunidades de investigación para desarrollar procesos de bioconversión técnicamente factible, eficiente y económicamente atractivo

Agave biotechnology: an overview.

Science.gov (United States)

Nava-Cruz, Naivy Y; Medina-Morales, Miguel A; Martinez, José L; Rodriguez, R; Aguilar, Cristóbal N

2015-01-01

Agaves are plants of importance both in Mexican culture and economy and in other Latin-American countries. Mexico is reported to be the place of Agave origin, where today, scientists are looking for different industrial applications without compromising its sustainability and preserving the environment. To make it possible, a deep knowledge of all aspects involved in production process, agro-ecological management and plant biochemistry and physiology is required. Agave biotechnology research has been focusing on bio-fuels, beverages, foods, fibers, saponins among others. In this review, we present the advances and challenges of Agave biotechnology.

Eddy covariance captures four-phase crassulacean acid metabolism (CAM) gas exchange signature in Agave.

Science.gov (United States)

Owen, Nick A; Choncubhair, Órlaith Ní; Males, Jamie; Del Real Laborde, José Ignacio; Rubio-Cortés, Ramón; Griffiths, Howard; Lanigan, Gary

2016-02-01

Mass and energy fluxes were measured over a field of Agave tequilana in Mexico using eddy covariance (EC) methodology. Data were gathered over 252 d, including the transition from wet to dry periods. Net ecosystem exchanges (FN,EC ) displayed a crassulacean acid metabolism (CAM) rhythm that alternated from CO2 sink at night to CO2 source during the day, and partitioned canopy fluxes (FA,EC ) showed a characteristic four-phase CO2 exchange pattern. Results were cross-validated against diel changes in titratable acidity, leaf-unfurling rates, energy exchange fluxes and reported biomass yields. Projected carbon balance (g C m(-2)  year(-1) , mean ± 95% confidence interval) indicated the site was a net sink of -333 ± 24, of which contributions from soil respiration were +692 ± 7, and FA,EC was -1025 ± 25. EC estimated biomass yield was 20.1 Mg (dry) ha(-1)  year(-1) . Average integrated daily FA,EC was -234 ± 5 mmol CO2  m(-2)  d(-1) and persisted almost unchanged after 70 d of drought conditions. Regression analyses were performed on the EC data to identify the best environmental predictors of FA . Results suggest that the carbon acquisition strategy of Agave offers productivity and drought resilience advantages over conventional semi-arid C3 and C4 bioenergy candidates. © 2015 John Wiley & Sons Ltd.

Use of agave bagasse for production of an organic fertilizer by pretreatment with Bjerkandera adusta and vermicomposting with Eisenia fetida.

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Moran-Salazar, Rene G; Marino-Marmolejo, Erika N; Rodriguez-Campos, Jacobo; Davila-Vazquez, Gustavo; Contreras-Ramos, Silvia M

2016-01-01

Agave tequilana Weber is used in tequila and fructans production, with agave bagasse generated as a solid waste. The main use of bagasse is to produce compost in tequila factories with a long traditional composting that lasts 6-8 months. The aim of this study was to evaluate the degradation of agave bagasse by combining a pretreatment with fungi and vermicomposting. Experiments were carried out with fractionated or whole bagasse, sterilized or not, subjecting it to a pretreatment with Bjerkandera adusta alone or combined with native fungi, or only with native bagasse fungi (non-sterilized), for 45 days. This was followed by a vermicomposting with Eisenia fetida and sewage sludge, for another 45 days. Physicochemical parameters, lignocellulose degradation, stability and maturity changes were measured. The results indicated that up to 90% of the residual sugars in bagasse were eliminated after 30 days in all treatments. The highest degradation rate in pretreatment was observed in non-sterilized, fractionated bagasse with native fungi plus B. adusta (BNFns) (71% hemicellulose, 43% cellulose and 71% lignin) at 45 days. The highest total degradation rates after vermicomposting were in fractionated bagasse pre-treated with native fungi (94% hemicellulose, 86% cellulose and 91% lignin). However, the treatment BNFns showed better maturity and stability parameters compared to that reported for traditional composts. Thus, it seems that a process involving vermicomposting and pretreatment with B. adusta could reduce the degradation time of bagasse to 3 months, compared to the traditional composting process, which requires from 6 to 8 months.

Overexpression of ADH1 and HXT1 genes in the yeast Saccharomyces cerevisiae improves the fermentative efficiency during tequila elaboration.

Science.gov (United States)

Gutiérrez-Lomelí, Melesio; Torres-Guzmán, Juan Carlos; González-Hernández, Gloria Angélica; Cira-Chávez, Luis Alberto; Pelayo-Ortiz, Carlos; Ramírez-Córdova, Jose de Jesús

2008-05-01

This work assessed the effect of the overexpression of ADH1 and HXT1 genes in the Saccharomyces cerevisiae AR5 strain during fermentation of Agave tequilana Weber blue variety must. Both genes were cloned individually and simultaneously into a yeast centromere plasmid. Two transformant strains overexpressing ADH1 and HXT1 individually and one strain overexpressing both genes were randomly selected and named A1, A3 and A5 respectively. Overexpression effect on growth and ethanol production of the A1, A3 and A5 strains was evaluated in fermentative conditions in A. tequilana Weber blue variety must and YPD medium. During growth in YPD and Agave media, all the recombinant strains showed lower cell mass formation than the wild type AR5 strain. Adh enzymatic activity in the recombinant strains A1 and A5 cultivated in A. tequilana and YPD medium was higher than in the wild type. The overexpression of both genes individually and simultaneously had no significant effect on ethanol formation; however, the fermentative efficiency of the A5 strain increased from 80.33% to 84.57% and 89.40% to 94.29% in YPD and Agave medium respectively.

Mass Spectrometry-Based Metabolomics of Agave Sap (Agave salmiana after Its Inoculation with Microorganisms Isolated from Agave Sap Concentrate Selected to Enhance Anticancer Activity

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Luis M. Figueroa

2017-11-01

Full Text Available Saponins have been correlated with the reduction of cancer cell growth and the apoptotic effect of agave sap concentrate. Empirical observations of this artisanal Mexican food have shown that fermentation occurs after agave sap is concentrated, but little is known about the microorganisms that survive after cooking, or their effects on saponins and other metabolites. The aim of this study was to evaluate the changes in metabolites found in agave (A. salmiana sap after its fermentation with microorganisms isolated from agave sap concentrate, and demonstrate its potential use to enhance anticancer activity. Microorganisms were isolated by dilution plating and identified by 16S rRNA analysis. Isolates were used to ferment agave sap, and their corresponding butanolic extracts were compared with those that enhanced the cytotoxic activity on colon (Caco-2 and liver (Hep-G2 cancer cells. Metabolite changes were investigated by mass spectrometry-based metabolomics. Among 69 isolated microorganisms, the actinomycetes Arthrobacter globiformis and Gordonia sp. were used to analyze the metabolites, along with bioactivity changes. From the 939 ions that were mainly responsible for variation among fermented samples at 48 h, 96 h, and 192 h, four were correlated to anticancer activity. It was shown that magueyoside B, a kammogenin glycoside, was found at higher intensities in the samples fermented with Gordonia sp. that reduced Hep-G2 viability better than controls. These findings showed that microorganisms from agave sap concentrate change agave sap metabolites such as saponins. Butanolic extracts obtained after agave sap fermentation with Arthrobacter globiformis or Gordonia sp. increased the cancer cell growth inhibitory effect on colon or liver cancer cells, respectively.

ANÁLISIS GENÉTICO PARA LA CONSERVACIÓN DE Agave cupreata TREL. & BERGER (AGAVACEAE).

OpenAIRE

Gómez Sierra, Juan Manuel

2012-01-01

Agave cupreata (maguey chino o papalote), es una planta solitaria, se distribuye principalmente en bosques de pino-encino, en altitudes que varían de 1220 a 1850 msnm en la depresión del Balsas de los estados de Guerrero y Michoacán, en los municipios de Tzitzio, Villa Madero, Morelia, Jungapeo, Turicato y Charo en Michoacán., y en Xochipala, Tixtla, Atlixtac, Chilapa de Alvarez entre otros en Guerrero (Gentry 1982, Martínez-Palacios comun. pers). Las comunidades marginadas ase...

Effect of dilution rate and nutrients addition on the fermentative capability and synthesis of aromatic compounds of two indigenous strains of Saccharomyces cerevisiae in continuous cultures fed with Agave tequilana juice.

Science.gov (United States)

Morán-Marroquín, G A; Córdova, J; Valle-Rodríguez, J O; Estarrón-Espinosa, M; Díaz-Montaño, D M

2011-11-15

Knowledge of physiological behavior of indigenous tequila yeast used in fermentation process is still limited. Yeasts have significant impact on the productivity fermentation process as well as the sensorial characteristics of the alcoholic beverage. For these reasons a better knowledge of the physiological and metabolic features of these yeasts is required. The effects of dilution rate, nitrogen and phosphorus source addition and micro-aeration on growth, fermentation and synthesis of volatile compounds of two native Saccharomyces cerevisiae strains, cultured in continuous fed with Agave tequilana juice were studied. For S1 and S2 strains, maximal concentrations of biomass, ethanol, consumed sugars, alcohols and esters were obtained at 0.04 h⁻¹. Those concentrations quickly decreased as D increased. For S. cerevisiae S1 cultures (at D=0.08 h⁻¹) supplemented with ammonium phosphate (AP) from 1 to 4 g/L, concentrations of residual sugars decreased from 29.42 to 17.60 g/L and ethanol increased from 29.63 to 40.08 g/L, respectively. The S1 culture supplemented with AP was then micro-aerated from 0 to 0.02 vvm, improving all the kinetics parameters: biomass, ethanol and glycerol concentrations increased from 5.66, 40.08 and 3.11 g/L to 8.04, 45.91 and 4.88 g/L; residual sugars decreased from 17.67 g/L to 4.48 g/L; and rates of productions of biomass and ethanol, and consumption of sugars increased from 0.45, 3.21 and 7.33 g/L·h to 0.64, 3.67 and 8.38 g/L·h, respectively. Concentrations of volatile compounds were also influenced by the micro-aeration rate. Ester and alcohol concentrations were higher, in none aerated and in aerated cultures respectively. Copyright © 2011. Published by Elsevier B.V.

Quantitative characterization of nonstructural carbohydrates of mezcal Agave (Agave salmiana Otto ex Salm-Dick).

Science.gov (United States)

Michel-Cuello, Christian; Juárez-Flores, Bertha Irene; Aguirre-Rivera, Juan Rogelio; Pinos-Rodríguez, Juan Manuel

2008-07-23

Fructans are the reserve carbohydrates in Agave spp. plants. In mezcal factories, fructans undergoes thermal hydrolysis to release fructose and glucose, which are the basis to produce this spirit. Carbohydrate content determines the yield of the final product, which depends on plant organ, ripeness stage, and thermal hydrolysis. Thus, a qualitative and quantitative characterization of nonstructural carbohydrates was conducted in raw and hydrolyzed juices extracted from Agave salmiana stems and leaves under three ripeness stages. By high-performance liquid chromatography (HPLC), fructose, glucose, sucrose, xylose, and maltose were identified in agave juice. Only the plant fraction with hydrolysis interaction was found to be significant in the glucose concentration plant. Interactions of the fraction with hydrolysis and ripeness with hydrolysis were statistically significant in fructose concentration. Fructose concentration rose considerably with hydrolysis, but only in juice extracted from ripe agave stems (early mature and castrated). This increase was statistically significant only with acid hydrolysis.

Purification and substrate specificities of a fructanase from Kluyveromyces marxianus isolated from the fermentation process of Mezcal.

Science.gov (United States)

Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

2011-02-01

A fructanase, produced by a Kluyveromyces marxianus strain isolated during the fermentation step of the elaboration process of "Mezcal de Guerrero" was purified and biochemically characterized. The active protein was a glycosylated dimer with a molecular weight of approximately 250 kDa. The specific enzymatic activity of the protein was determined for different substrates: sucrose, inulin, Agave tequilana fructan, levan and Actilight® and compared with the activity of Fructozyme®. The hydrolysis profile of the different substrates analyzed by HPAEC-PAD showed that the enzyme has different affinities over the substrates tested with a sucrose/inulin enzymatic activity ratio (S/I) of 125. For the hydrolysis of Agave tequilana fructans, the enzyme also showed a higher enzymatic activity and specificity than Fructozyme®, which is important for its potential application in the tequila industry. Copyright © 2010 Elsevier Ltd. All rights reserved.

African Journal of Biotechnology - Vol 10, No 47 (2011)

African Journals Online (AJOL)

Biofertilization of micropropagated Agave tequilana: Effect on plant growth and production of hydrolytic enzymes · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. S Ruiz, L Adriano, I Ovando, C Navarro, M Salvador, 9631-9639 ...

Pulp and paper from blue agave waste from tequila production.

Science.gov (United States)

Idarraga, G; Ramos, J; Zuñiga, V; Sahin, T; Young, R A

1999-10-01

Pulping of blue agave waste, from the production of tequila, was evaluated by both chemical and biomechanical pulping processes. Two conventional and two organosolv systems were used to pulp the agave waste under a standard set of conditions. The soda-ethanol process was superior in terms of delignification and pulp properties in comparison to the soda and ethanol organosolv processes for pulping of agave waste; however, the kraft process gave the best strength properties. In general, the strength of the agave waste pulps was rather poor in comparison to wood and other agro-based pulps; however, the tear strength was relatively high. This result is typical of poorly bonded sheets and may be due to the coarseness of the agave fibers and/or loss of hemicelluloses in the steaming process for the tequila production. Fungal treatment of the agave waste with Ceriporiopsis subvermispora reduced the energy consumption for mechanical refining but gave biomechanical pulps with inferior strength properties. The blue agave chemical pulps should be suitable for blending with softwood kraft pulps for publication grade paper.

Agave Chewing and Dental Wear: Evidence from Quids.

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Emily E Hammerl

Full Text Available Agave quid chewing is examined as a potential contributing behavior to hunter-gatherer dental wear. It has previously been hypothesized that the contribution of Agave quid chewing to dental wear would be observed in communities wherever phytolith-rich desert succulents were part of subsistence. Previous analysis of coprolites from a prehistoric agricultural site, La Cueva de los Muertos Chiquitos in Durango, Mexico, showed that Agave was a consistent part of a diverse diet. Therefore, quids recovered at this site ought to be useful materials to test the hypothesis that dental wear was related to desert succulent consumption. The quids recovered from the site were found to be largely derived from chewing Agave. In this study, the quids were found to be especially rich in phytoliths, and analysis of dental casts made from impressions left in the quids revealed flat wear and dental attrition similar to that of Agave-reliant hunter-gatherers. Based on evidence obtained from the analysis of quids, taken in combination with results from previous studies, it is determined that Agave quid chewing was a likely contributing factor to dental wear in this population. As such, our method provides an additional avenue of dental research in areas where quids are present.

Sustainability analysis of agave production in Mexico

NARCIS (Netherlands)

Ibarrola Rivas, Maria Jose

2010-01-01

Worldwide food production is done in different types of agricultural production systems. The main difference is whether it is an intensive or extensive system. The agave production in Mexico has been developed in these two different ways. Firstly, agave f

Physical mapping of 5S and 18S ribosomal DNA in three species of Agave (Asparagales, Asparagaceae

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Victor Manuel Gomez-Rodriguez

2013-08-01

Full Text Available Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country’s economy. Cytogenetic analysis was carried out in A. tequilana Weber, 1902 ‘Azul’, A. cupreata Trelease et Berger, 1915 and A. angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH was used for physical mapping of 5S and 18S ribosomal DNA (rDNA. All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.

Mining the Agave Microbiome for adaptions to arid environments

Energy Technology Data Exchange (ETDEWEB)

Coleman-Derr, Devin; Wojke, Tanja; North, Gretchen; Partida-Martinez, Laila; DeAngeli, Kristen; Clingenpeel, Scott; Gross, Stephen; Tringe, Susannah; Visel, Axel

2013-03-25

A major challenge facing the biofuels industry is the identification of high-yield plant feedstocks that can be cultivated with minimal resource inputs without competing for land and water supplies with existing food crops. Recent research has demonstrated that the Agave plant, cultivated in Mexico and Southwestern United States for the production of fiber and alcohol, meets these criteria1. Agaves grow on non-arable rocky soils in regions characterized by prolonged drought and extreme temperatures, due in part to physiological adaptions that prevent excess water-loss in arid environments2. Plant-microbial symbioses can play a role in helping plants adapt to heat and drought stress, increasing the accessibility of soil nutrients, or compete with plant pathogens3. Whether agaves have similar beneficial microbe interactions in their native environment is unknown. We aim to provide a comprehensive characterization of the Agave microbiome, with the goal of identifying specific community members that may contribute to Agave biotic and abiotic stress tolerance

Agave Americana Leaf Fibers

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Ashish Hulle

2015-02-01

Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

Performance evaluation of Pichia kluyveri, Kluyveromyces marxianus and Saccharomyces cerevisiae in industrial tequila fermentation.

Science.gov (United States)

Amaya-Delgado, L; Herrera-López, E J; Arrizon, Javier; Arellano-Plaza, M; Gschaedler, A

2013-05-01

Traditionally, industrial tequila production has used spontaneous fermentation or Saccharomyces cerevisiae yeast strains. Despite the potential of non-Saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. Therefore, in this work, Agave tequilana juice was fermented at an industrial level using two non-Saccharomyces yeasts (Pichia kluyveri and Kluyveromyces marxianus) with fermentation efficiency higher than 85 %. Pichia kluyveri (GRO3) was more efficient for alcohol and ethyl lactate production than S. cerevisiae (AR5), while Kluyveromyces marxianus (GRO6) produced more isobutanol and ethyl-acetate than S. cerevisiae (AR5). The level of volatile compounds at the end of fermentation was compared with the tequila standard regulation. All volatile compounds were within the allowed range except for methanol, which was higher for S. cerevisiae (AR5) and K. marxianus (GRO6). The variations in methanol may have been caused by the Agave tequilana used for the tests, since this compound is not synthesized by these yeasts.

Determination of chromosomal ploidy in Agave ssp. | Lingling ...

African Journals Online (AJOL)

Chromosome observation is necessary to elucidate the structure, function and organization of Agave plants' genes and genomes. However, few researches about chromosome observation of Agave ssp. were done, not only because their chromosome numbers are large, but also because their ploidies are complicated.

Multivariate analysis of FTIR and ion chromatographic data for the quality control of tequila.

Science.gov (United States)

Lachenmeier, Dirk W; Richling, Elke; López, Mercedes G; Frank, Willi; Schreier, Peter

2005-03-23

Principal component analysis (PCA) was applied to the chromatographic and spectroscopic data of authentic Mexican tequilas (n = 14) and commercially available samples purchased in Mexico and Germany (n = 24). The scores scatter plot of the first two principal components (PC) of the anions chloride, nitrate, sulfate, acetate, and oxalate accounting for 78% of the variability allowed a classification between tequilas bottled in Mexico and overseas; however, no discrimination between tequila categories was possible. Mexican products had a significantly (p = 0.0014) lower inorganic anion concentration (range = 1.5-5.1 mg/L; mean = 2.5 mg/L) than the products bottled in the importing countries (range = 3.3-62.6 mg/L; mean = 26.3 mg/L). FTIR allowed a rapid screening of density and ethanol as well as the volatile compounds methanol, ethyl acetate, propanol-1, isobutanol, and 2-/3-methyl-1-butanol using partial least-squares regression (precisions = 5.3-29.3%). Using PCA of the volatile compounds, a differentiation between tequila derived from "100% agave" (Agave tequilana Weber var. azul, Agavaceae) and tequila produced with other fermentable sugars ("mixed"tequila) was possible. The first two PCs describe 89% of the total variability of the data. Methanol and isobutanol influenced the variability in PC1, which led to discrimination. The concentrations of methanol and isobutanol were significantly higher (methanol, p = 0.004; isobutanol, p = 0.005) in the 100% agave (methanol, 297.9 +/- 49.5; isobutanol, 251.3 +/- 34.9) than in the mixed tequilas (methanol, 197.8 +/- 118.5; isobutanol, 151.4 +/- 52.8).

Methylene blue biosorption by pericarp of corn, alfalfa, and agave bagasse wastes.

Science.gov (United States)

Rosas-Castor, José M; Garza-González, María T; García-Reyes, Refugio B; Soto-Regalado, Eduardo; Cerino-Córdova, Felipe J; García-González, Alcione; Loredo-Medrano, José A

2014-01-01

The presence of dyes in effluent is a matter of concern due to their toxicologic and aesthetical effects. In this research, locally available agro-industrial wastes (Zea mays pericarp, ZMP; Agave tequilana bagasse, ATB; and Medicago sativa waste, MSW) were used as alternative low-cost adsorbents for the removal of methylene blue (MB) from aqueous solutions. The adsorbents were characterized physically and chemically by Fourier transform infrared, scanning electron microscopy, potentiometric titrations, and N2 physisorption. MB adsorption experiments were carried out in batch systems and experimental data were used to calculate the adsorption isotherm model parameters (Langmuir, Freundlich, and Temkin) and the adsorption kinetic model parameters (pseudo-first- and pseudo-second-order models). MB-loaded biosorbents were desorbed with deionized water, ethanol (10% and 50% v/v), hydrochloric acid (0.01 and 0.05 N), and sodium hydroxide (0.1 N) at room temperature, and the best eluent was used in various adsorption-desorption cycles. The selected agricultural wastes can be considered as promising adsorbents for dye uptake from water since they exhibit considerable MB adsorption capacity (MSW 202.6 mg g(-1), ATB 156.2mg g(-1), and ZMP 110.9mg g(-1)), but it is lower than that reported for activated carbon; however, the biosorbents show higher adsorption rate than powdered activated carbon. Furthermore, the adsorbents can be economically regenerated with HCl solutions and reused for seven adsorption-desorption cycles.

Diazotrophic potential among bacterial communities associated with wild and cultivated Agave species.

Science.gov (United States)

Desgarennes, Damaris; Garrido, Etzel; Torres-Gomez, Miryam J; Peña-Cabriales, Juan J; Partida-Martinez, Laila P

2014-12-01

Agaves are major biotic resources in arid and semi-arid ecosystems. Despite their ecological, economical and cultural relevance, many aspects of the microbial communities associated with agaves are still unknown. Here, we investigated the bacterial communities associated with two Agave species by 16S rRNA- Denaturing gradient gel electrophoresis fingerprinting and sequencing. We also evaluated the effects of biotic and abiotic factors in the structure of the bacterial communities. In parallel, we isolated and characterized diazotrophic bacteria associated with agaves, as Agave soils are characterized by their low nitrogen content. Our results demonstrate that in Agave, the structure of prokaryotic assemblages was mostly influenced by the community group, where the soil, episphere, and endosphere were clearly distinct. Proteobacteria (γ and α), Actinobacteria, and Acidobacteria were the dominant phyla. Bacterial communities in the episphere of agaves were mainly influenced by the host species, whereas in the endosphere were affected by the season. Fifteen bacterial taxa were common and abundant in the endosphere of both Agave species during the dry season. Notably, some of the confirmed diazotrophic strains belonged to this group, suggesting a possible beneficial role in planta. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Continuous hydrogen and methane production from Agave tequilana bagasse hydrolysate by sequential process to maximize energy recovery efficiency.

Science.gov (United States)

Montiel Corona, Virginia; Razo-Flores, Elías

2018-02-01

Continuous H 2 and CH 4 production in a two-stage process to increase energy recovery from agave bagasse enzymatic-hydrolysate was studied. In the first stage, the effect of organic loading rate (OLR) and stirring speed on volumetric hydrogen production rate (VHPR) was evaluated in a continuous stirred tank reactor (CSTR); by controlling the homoacetogenesis with the agitation speed and maintaining an OLR of 44 g COD/L-d, it was possible to reach a VHPR of 6 L H 2 /L-d, equivalent to 1.34 kJ/g bagasse. In the second stage, the effluent from CSTR was used as substrate to feed a UASB reactor for CH 4 production. Volumetric methane production rate (VMPR) of 6.4 L CH 4 /L-d was achieved with a high OLR (20 g COD/L-d) and short hydraulic retention time (HRT, 14 h), producing 225 mL CH 4 /g-bagasse equivalent to 7.88 kJ/g bagasse. The two-stage continuous process significantly increased energy conversion efficiency (56%) compared to one-stage hydrogen production (8.2%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of the fructose and glucose concentration on the rheological ...

African Journals Online (AJOL)

The objective of this work was to study the effect of fructose and glucose content on the rheological behavior of syrups. Initially, high fructose syrup from the fructans present in leaves, bases and head of Agave tequilana Weber blue was obtained. Then, its contents of moisture, ash, fructose, glucose and direct and total ...

Fast Centrifugal Partition Chromatography Fractionation of Concentrated Agave (Agave salmiana) Sap to Obtain Saponins with Apoptotic Effect on Colon Cancer Cells.

Science.gov (United States)

Santos-Zea, Liliana; Fajardo-Ramírez, Oscar R; Romo-López, Irasema; Gutiérrez-Uribe, Janet A

2016-03-01

Separation of potentially bioactive components from foods and plant extracts is one of the main challenges for their study. Centrifugal partition chromatography has been a successful technique for the screening and identification of molecules with bioactive potential, such as steroidal saponins. Agave is a source of steroidal saponins with anticancer potential, though the activity of these compounds in concentrated agave sap has not been yet explored. In this study, fast centrifugal partition chromatography (FCPC) was used coupled with in vitro tests on HT-29 cells as a screening procedure to identify apoptotic saponins from an acetonic extract of concentrated agave sap. The three most bioactive fractions obtained by FCPC at partition coefficients between 0.23 and 0.4 contained steroidal saponins, predominantly magueyoside b. Flow cytometry analysis determined that the fraction rich in kammogenin and manogenin glycosides induced apoptosis, but when gentrogenin and hecogenin glycosides were also found in the fraction, a necrotic effect was observed. In conclusion, this study provides the evidence that steroidal saponins in concentrated agave sap were potential inductors of apoptosis and that it was possible to separate them using fast centrifugal partition chromatography.

Tequila production.

Science.gov (United States)

Cedeño, M

1995-01-01

Tequila is obtained from the distillation of fermented juice of agave plant, Agave tequilana, to which up to 49% (w/v) of an adjunct sugar, mainly from cane or corn, could be added. Agave plants require from 8 to 12 years to mature and during all this time cleaning, pest control, and slacken of land are required to produce an initial raw material with the appropriate chemical composition for tequila production. Production process comprises four steps: cooking to hydrolyze inulin into fructose, milling to extract the sugars, fermentation with a strain of Saccharomyces cerevisiae to convert the sugars into ethanol and organoleptic compounds, and, finally, a two-step distillation process. Maturation, if needed, is carried out in white oak barrels to obtain rested or aged tequila in 2 or 12 months, respectively.

Agave as a model CAM crop system for a warming and drying world.

Science.gov (United States)

Stewart, J Ryan

2015-01-01

As climate change leads to drier and warmer conditions in semi-arid regions, growing resource-intensive C3 and C4 crops will become more challenging. Such crops will be subjected to increased frequency and intensity of drought and heat stress. However, agaves, even more than pineapple (Ananas comosus) and prickly pear (Opuntia ficus-indica and related species), typify highly productive plants that will respond favorably to global warming, both in natural and cultivated settings. With nearly 200 species spread throughout the U.S., Mexico, and Central America, agaves have evolved traits, including crassulacean acid metabolism (CAM), that allow them to survive extreme heat and drought. Agaves have been used as sources of food, beverage, and fiber by societies for hundreds of years. The varied uses of Agave, combined with its unique adaptations to environmental stress, warrant its consideration as a model CAM crop. Besides the damaging cycles of surplus and shortage that have long beset the tequila industry, the relatively long maturation cycle of Agave, its monocarpic flowering habit, and unique morphology comprise the biggest barriers to its widespread use as a crop suitable for mechanized production. Despite these challenges, agaves exhibit potential as crops since they can be grown on marginal lands, but with more resource input than is widely assumed. If these constraints can be reconciled, Agave shows considerable promise as an alternative source for food, alternative sweeteners, and even bioenergy. And despite the many unknowns regarding agaves, they provide a means to resolve disparities in resource availability and needs between natural and human systems in semi-arid regions.

Agave as a model CAM crop system for a warming and drying world

Directory of Open Access Journals (Sweden)

J. Ryan eStewart

2015-09-01

Full Text Available As climate change leads to drier and warmer conditions in semi-arid regions, growing resource-intensive C3 and C4 crops will become more challenging. Such crops will be subjected to increased frequency and intensity of drought and heat stress. However, agaves, even more than pineapple (Ananas comosus and prickly pear (Opuntia ficus-indica and related species, typify highly productive plants that will respond favorably to global warming, both in natural and cultivated settings. With nearly 200 species spread throughout the U.S., Mexico, and Central America, agaves have evolved traits, including crassulacean acid metabolism (CAM, that allow them to survive extreme heat and drought. Agaves have been used as sources of food, beverage, and fiber by societies for hundreds of years. The varied uses of Agave, combined with its unique adaptations to environmental stress, warrant its consideration as a model CAM crop. Besides the damaging cycles of surplus and shortage that have long beset the tequila industry, the relatively long maturation cycle of Agave, its monocarpic flowering habit, and unique morphology comprise the biggest barriers to its widespread use as a crop suitable for mechanized production. Despite these challenges, agaves exhibit potential as crops since they can be grown on marginal lands, but with more resource input than is widely assumed. If these constraints can be reconciled, Agave shows considerable promise as an alternative source for food, alternative sweeteners, and even bioenergy. And despite the many unknowns regarding agaves, they provide a means to resolve disparities between natural and human systems in semi-arid regions.

Physical properties of agave cellulose graft polymethyl methacrylate

Energy Technology Data Exchange (ETDEWEB)

Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan [Polymer Research Centre (PORCE), School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor (Malaysia)

2013-11-27

The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

Agaves as a raw material: recent technologies and applications.

Science.gov (United States)

Narváez-Zapata, J A; Sánchez-Teyer, L F

2009-01-01

Agave plants are a valuable source of raw material due to its fibrous and complex sugar content of their leaves and core, and their bagasse waste can be use for several aims. This plant genus belongs to the Agavaceae family and until now more than 200 species have been described. A large number of Agave species are currently used as raw material in several biotechnological processes. This review shows the reported applications and patents on fields like alcoholic brewages with special reference to Tequila and Mezcal, the isolation and use of compounds such as saponins and agave fructans, and their potential biotechnological application on several human demands. The process to obtain fibers and cellulose, stock feeds, and several miscellaneous extractives are also reviewed. Some possibilities and problems of cultivation are discussed.

Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

International Nuclear Information System (INIS)

Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

2014-01-01

The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

Influence of thermal effect on sugars composition of Mexican Agave syrup

NARCIS (Netherlands)

Muniz-Marquez, D.B.; Contreras, J.C.; Rodriguez, R.; Mussatto, S.I.; Wong-Paz, J.E.; Teixeira, J.A.; Aguilar, C.N.

2015-01-01

Agave syrup is a fermentable by-product from the Agave industry that is used for pulque production, a typical Mexican fermented beverage. However, to date, the information available on its physicochemical composition is scarce, with this study being one of the first contributions on the subject.

Effects of the addition of different nitrogen sources in the tequila fermentation process at high sugar concentration.

Science.gov (United States)

Arrizon, J; Gschaedler, A

2007-04-01

To study the effect of the addition of different nitrogen sources at high sugar concentration in the tequila fermentation process. Fermentations were performed at high sugar concentration (170 g l(-1)) using Agave tequilana Weber blue variety with and without added nitrogen from different sources (ammonium sulfate; glutamic acid; a mixture of ammonium sulfate and amino acids) during the exponential phase of growth. All the additions increased the fermentation rate and alcohol efficiency. The level of synthesis of volatile compounds depended on the source added. The concentration of amyl alcohols and isobutanol were decreased while propanol and acetaldehyde concentration increased. The most efficient nitrogen sources for fermentation rate were ammonium sulfate and the mixture of ammonium sulfate and amino acids. The level of volatile compounds produced depended upon types of nitrogen. The synthesis of some volatile compounds increased while others decreased with nitrogen addition. The addition of nitrogen could be a strategy for improving the fermentation rate and efficiency in the tequila fermentation process at high sugar Agave tequilana concentration. Furthermore, the sensory quality of the final product may change because the synthesis of the volatile compounds is modified.

Fermentative capabilities and volatile compounds produced by Kloeckera/Hanseniaspora and Saccharomyces yeast strains in pure and mixed cultures during Agave tequilana juice fermentation.

Science.gov (United States)

González-Robles, Ivonne Wendolyne; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

2015-09-01

The fermentative and aromatic capabilities of Kloeckera africana/Hanseniaspora vineae K1, K. apiculata/H. uvarum K2, and Saccharomyces cerevisiae S1 and S2 were studied in pure and mixed culture fermentations using Agave tequila juice as the culture medium. In pure and mixed cultures, Kloeckera/Hanseniaspora strains showed limited growth and sugar consumption, as well as low ethanol yield and productivity, compared to S. cerevisiae, which yielded more biomass, ethanol and viable cell concentrations. In pure and mixed cultures, S. cerevisiae presented a similar behaviour reaching high biomass production, completely consuming the sugar, leading to high ethanol production. Furthermore, the presence of S. cerevisiae strains in the mixed cultures promoted the production of higher alcohols, acetaldehyde and ethyl esters, whereas Kloeckera/Hanseniaspora strains stimulated the production of ethyl acetate and 2-phenyl ethyl acetate compounds.

Establishing of Agave Americana industry in South Africa

CSIR Research Space (South Africa)

Boguslavsky, A

2007-09-01

Full Text Available of the sisal decorticator was therefore modified to make it more suitable for the processing of Agave Americana leaves. Steel side plates were attached to the rotor to prevent the blockage of the machine. The feeding tray and beater bars were modified... to accommodate the side plates of the enlarged rotor. For added operator safety, a “tunnel” guard was also added the feeding tray through which the leaves are fed. The size of this was such that the Agave leaf could fit into it but without any space...

Notes on Agave in the Netherlands West Indies and North Venezuela

NARCIS (Netherlands)

Wagenaar Hummelinck, P.

1938-01-01

In Curaçao, Aruba and Bonaire the most common species of Agave is A. vivipara. Although the variability is rather great, this species is nearly always easily recognizable. In Aruba, however, in two localities agaves are found, namely A. Rutteniae and A. arubensis, which differ from A. vivipara in

Enzymatic hydrolysis at high-solids loadings for the conversion of agave bagasse to fuel ethanol

International Nuclear Information System (INIS)

Caspeta, Luis; Caro-Bermúdez, Mario A.; Ponce-Noyola, Teresa; Martinez, Alfredo

2014-01-01

Highlights: • Conversion of agave bagasse to fuel ethanol. • Ethanosolv-pretreatment variables were statistically adjusted. • 91% of total sugars found in agave bagasse were recovered. • 225 g/L glucose from 30%-consistency hydrolysis using mini-reactors with peg-mixers. • 0.25 g of ethanol per g of dry agave bagasse was obtained. - Abstract: Agave bagasse is the lignocellulosic residue accumulated during the production of alcoholic beverages in Mexico and is a potential feedstock for the production of biofuels. A factorial design was used to investigate the effect of temperature, residence time and concentrations of acid and ethanol on ethanosolv pretreatment and enzymatic hydrolysis of agave bagasse. This method and the use of a stirred in-house-made mini-reactor increased the digestibility of agave bagasse from 30% observed with the dilute-acid method to 98%; also allowed reducing the quantity of enzymes used to hydrolyze samples with solid loadings of 30% w/w and glucose concentrations up to 225 g/L were obtained in the enzymatic hydrolysates. Overall this process allows the recovery of 91% of the total fermentable sugars contained in the agave bagasse (0.51 g/g) and 69% of total lignin as co-product (0.11 g/g). The maximum ethanol yield under optimal conditions using an industrial yeast strain for the fermentation was 0.25 g/g of dry agave bagasse, which is 86% of the maximum theoretical (0.29 g/g). The effect of the glucose concentration and solid loading on the conversion of cellulose to glucose is discussed, in addition to prospective production of about 50 million liters of fuel ethanol using agave bagasse residues from the tequila industry as a potential solution to the disposal problems

Increasing fermentation efficiency at high sugar concentrations by supplementing an additional source of nitrogen during the exponential phase of the tequila fermentation process.

Science.gov (United States)

Arrizon, Javier; Gschaedler, Anne

2002-11-01

In the tequila industry, fermentation is traditionally achieved at sugar concentrations ranging from 50 to 100 g x L(-1). In this work, the behaviour of the Saccharomyces cerevisiae yeast (isolated from the juices of the Agave tequilana Weber blue variety) during the agave juice fermentation is compared at different sugar concentrations to determine if it is feasible for the industry to run fermentation at higher sugar concentrations. Fermentation efficiency is shown to be higher (above 90%) at a high concentration of initial sugar (170 g x L(-1)) when an additional source of nitrogen (a mixture of amino acids and ammonium sulphate, different than a grape must nitrogen composition) is added during the exponential growth phase.

Effects of different sources of fructans on body weight, blood metabolites and fecal bacteria in normal and obese non-diabetic and diabetic rats.

Science.gov (United States)

Rendón-Huerta, Juan A; Juárez-Flores, Bertha; Pinos-Rodríguez, Juan M; Aguirre-Rivera, J Rogelio; Delgado-Portales, Rosa E

2012-03-01

Fructans contribute significantly to dietary fiber with beneficial effects on gastrointestinal physiology in healthy individuals and offer a promising approach to treating some diseases. Two experiments (Experiment 1 = rats with normal weight; Experiment 2 = obese rats) were developed to compare the effects of three fructan sources (Cichorium intybus L. Asteraceae, Helianthus tuberosus L. Asteraceae and Agave angustifolia ssp. tequilana Haw, Agavaceae) on body weight change, blood metabolites and fecal bacteria in non-diabetic (ND) and diabetic (D) rats. In Experiment 1 total body weight gain and daily feed intake in D and ND rats decreased (P tequilana decreased blood cholesterol and LDL and liver steatosis. For both ND and D rats, fecal Lactobacillus spp. and Bifidobacterium spp. counts were higher (P < 0.05) with fructan supplements.

Estudo comparativo entre espécies de agave Field trial on agave species

Directory of Open Access Journals (Sweden)

Dirceu Ciaramello

1975-01-01

Full Text Available Agave sisalana e A. fourcroydes, responsáveis pela produção de praticamente 90% das fibras duras consumidas no mundo, foram estudadas comparativamente em relação a A. amaniensis, A. letonae, A. zapupe e A. sisalana f. marginata, de 1965 a 1974, em experimento conduzido na E.E. de Tatui, do Instituto Agronômico. Ao completar nove anos de plantio no campo, a espécie A. fourcroydes ainda se encontrava com todas as plantas em produção, tendo as demais espécies concluído o ciclo vegetativo em períodos que variaram de quatro a oito anos. A. fourcroydes produziu a maior quantidade total de fibras por planta, com 5.044 gramas, enquanto A. sisalana apresentou a maior produção média anual, com 582 gramas de fibras secas por planta. Agave sisalana, tanto em sua forma normal como na variegada, deu, aproximadamente, o mesmo número de folhas que o obtido, até ao presente, para A. fourcroydes; as demais espécies produziram menor número de folhas.A trial designed to compare the fiber production of Agave sisalana, A. fourcroydes, A. amaniensis, A. letonae, A. zapupe, and A. sisalana f. marginatawas conducted from 1966 to 1974, at the Tatui Experimental Station, of the Instituto Agronômico, S. Paulo State, Brazil. A. zapupe was the first to pole, at the fourth year, being followed by A. letonae, A. amaniensis, A. sisalana, and A. sisalana f. marginata. A. fourcroydesdid not pole until the ninth year. The spacing adopted was 3 m x 1 m and each species produced per plant respectively: 2 kg for A. zapupe, 3 kg for A. amaniensis and A. letonae, 4 kg for A. sisalana and A. sisalana f. marginata, and 5 kg for A. fourcroydes of dried fiber. Considering the poling age A. sisalana gave the highest production, with the average of 582 g of dried fibers per year by plant.

Self-assembled ZnO agave-like nanowires and anomalous superhydrophobicity

Energy Technology Data Exchange (ETDEWEB)

Yang, Y H; Li, Z Y; Wang, B; Wang, C X; Chen, D H; Yang, G W [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics Science and Engineering, Zhongshan University, Guangzhou 510275 (China)

2005-09-07

Thin films of ZnO agave-like nanowires were prepared on amorphous carbon thin layers on silicon substrates using thermal chemical vapour transport and condensation without any metal catalysts. The unusual superhydrophobicity of the fabricated surface was measured; the water contact angle reaches 151.1 deg. On the basis of experimental and theoretical analyses, it appears likely that the biomimetic microcomposite and nanocomposite surfaces of the prepared thin films of ZnO agave-like nanowires are responsible for the excellent superhydrophobicity.

Oligosaccharides isolated from Agave vera cruz

NARCIS (Netherlands)

Vliegenthart, J.F.G.; Dorland, L.; Kamerling, J.P.; Satyanarayana, M.N.

1977-01-01

The structures of naturally occurring and enzymically synthesized oligosaccharides, consisting of fructose and glucose residues and having d.p. 3–8, in the stem of Agave vera cruz have been investigated by using methylation analysis, mass spectrometry, and p.m.r. spectroscopy. The naturally

Biological activities of Agave by-products and their possible applications in food and pharmaceuticals.

Science.gov (United States)

López-Romero, Julio Cesar; Ayala-Zavala, Jesús Fernando; González-Aguilar, Gustavo Adolfo; Peña-Ramos, Etna Aida; González-Ríos, Humberto

2018-05-01

Agave leaves are considered a by-product of alcoholic beverage production (tequila, mezcal and bacanora) because they are discarded during the production process, despite accounting for approximately 50% of the total plant weight. These by-products constitute a potential source of Agave extracts rich in bioactive compounds, such as saponins, phenolic compounds and terpenes, and possess different biological effects, as demonstrated by in vitro and in vivo tests (e.g. antimicrobial, antifungal, antioxidant, anti-inflammatory, antihypertensive, immunomodulatory, antiparasitic and anticancer activity). Despite their positive results in biological assays, Agave extracts have not been widely evaluated in food systems and pharmaceutical areas, and these fields represent a potential route to improve the usage of Agave plants as food additives and agents for treating medical diseases. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

Directory of Open Access Journals (Sweden)

Sascha Siebenhaller

2018-02-01

Full Text Available Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES. Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

Science.gov (United States)

Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

2018-02-01

Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents. Since it has been shown that it is possible to synthesize sugar esters in these deep eutectic solvents, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography and compared to a sugar ester which was synthesized in a conventional deep eutectic solvent. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

CARACTERIZAÇÃO TECNOLÓGICA DE HÍBRIDOS DE AGAVE

Directory of Open Access Journals (Sweden)

ANISIO AZZINI

1998-01-01

Full Text Available Determinou-se a produção de fibras e os teores de matéria seca e os de fibras e frações não fibrosas em folhas de 152 hibridos de Agave, comparando-se esses dados com os da espécie típica (Agave sisalana. Os híbridos foram obtidos do retrocruzamento (A. amaniensis x A. angustifolia x A. amaniensis. As produções de fibra (0,2 a 2,5 kg/planta e os teores de matéria seca (142,3 a 216,0 g/kg, de fibras (189,9 a 361,9 g/kg e de frações não fibrosas (219,2 a 365,1 g/kg em folhas, variaram acentuadamente entre os híbridos, em comparação com os resultados da espécie típica. A produção média de fibras (1,4 kg/planta dos 58 híbridos mais produtivos foi o dobro da produção da espécie A. sisalana (0,7 kg/planta.Fiber production per plant and leaf dry matter content as well as leaf fiber and non-fibrous fraction levels have been scored in 152 Agave hybrids, and the results compared with those of Agave sisalana (common species. Those hybrids were derived from the backcross (A. amaniensis x A. angustifolia x A. amaniensis. Fiber production (0.2 to 2.5 kg/plant, leaf dry matter content (142.3 to 216.0 g/kg, leaf fiber (189.9 to 361.9 g/kg and leaf non-fibrous fraction (219.2 to 365.1 g/kg varied sharply among the hybrids tested, as compared with the values obtained in Agave sisalana. Average fiber production (1.4 kg/plant from the 58 highest yielding hybrids significantly outscored that of the common species (0.7 kg/plant.

Fabrication of polystyrene/agave particle biocomposites using ...

Indian Academy of Sciences (India)

Polystyrene (PS) composites reinforced with ungrafted and acrylonitrile (AN) grafted agave particles (AgP) have been prepared with 10–30% particle content by weight using compression molding technique. The composite specimens thus prepared were subjected to the evaluation of mechanical, chemical, flammability and ...

Identification of the temperature- induced larvicidal efficacy of Agave angustifolia against Aedes, Culex and Anopheles larvae

Directory of Open Access Journals (Sweden)

Mithilesh eKajla

2016-01-01

Full Text Available Synthetic insecticides are generally employed to control the mosquito population. However, their injudicious over usage and non-biodegradability are associated with many adverse effects on the environment and mosquitoes. The application of environment-friendly mosquitocidals might be an alternate to overcome these issues. In this study, we found that organic or aqueous extracts of Agave angustifolia leaves exhibited a strong larvicidal activity (LD50 28.27 µg/ml against Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi larvae within a short exposure of 12h. The larvicidal activity of Agave angustifolia is inherited and independent of the plants vegetative growth. Interestingly, the plant larvicidal activity was observed exclusively during the summer season (April-August, when outside temperature is between 30oC to 50oC and it was significantly reduced during winter season (December-February, when the outside temperature falls to ~4oC or lower. Thus, we hypothesized that the larvicidal components of Agave angustifolia might be induced by the manipulation of environmental temperature and should be resistant to the hot conditions. We found that the larvicidal activity of Agave angustifolia was induced when plants were maintained at 37oC in a semi-natural environment against the controls that were growing outside in cold weather. Pre-incubation of Agave angustifolia extract at 100oC for 1h killed 60% larvae in 12h, which gradually increased to 100% mortality after 24h. In addition, the dry powder formulation of Agave angustifolia, also displayed a strong larvicidal activity after a long shelf life. Together, these findings revealed that Agave angustifolia is an excellent source of temperature induced bioactive metabolites that may assist the preparedness for vector control programs competently.

Revisión del agave y el mezcal

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María Del Carmen Chavez-Parga

2016-01-01

Full Text Available En el presente trabajo, se efectuó una compilación de investigaciones realizadas sobre las diferentes etapas del proceso productivo del mezcal a partir de agave en algunas regiones productoras de México; con el propósito de explicar las problemáticas que enfrenta la cadena productiva agave-mezcal y las estrategias científicas que se han desarrollado para solucionarlas. Con ello se pretende lograr su resistencia y persistencia productiva en el mercado, elaborando un producto que cumpla con las características químicas establecidas por las normas oficiales mexicanas de producción y certificación de calidad, además de ofrecer posibles medidas de control en los procesos para estandarizar el producto y finalmente lograr etapas más eficientes en el proceso de producción.

Quantification of selected volatile constituents and anions in Mexican Agave spirits (Tequila, Mezcal, Sotol, Bacanora).

Science.gov (United States)

Lachenmeier, Dirk W; Sohnius, Eva-Maria; Attig, Rainer; López, Mercedes G

2006-05-31

A large collection (n = 95) of Mexican Agave spirits with protected appellations of origin (Tequila, Mezcal, Sotol, and Bacanora) was analyzed using ion and gas chromatography. Because of their production from oxalate-containing plant material, all Agave spirits contained significant concentrations of oxalate (0.1-9.7 mg/L). The two Tequila categories ("100% Agave" and "mixed") showed differences in the methanol, 2-/3-methyl-1-butanol, and 2-phenylethanol concentrations with lower concentrations in the mixed category. Mezcal showed no significant differences in any of the evaluated parameters that would allow a classification. Sotol showed higher nitrate concentrations and lower 2-/3-methyl-1-butanol concentrations. Bacanora was characterized by exceptionally high acetaldehyde concentrations and a relatively low ethyl lactate content. The methanol content was the most problematic compound regarding the Mexican standards: two Tequilas (4%), five Sotols (31%), and six Bacanoras (46%) had levels above the maximum methanol content of 300 g/hL of alcohol. In conclusion, the composition of Mexican Agave spirits was found to vary over a relatively large range.

Prebiotic Potential of Agave angustifolia Haw Fructans with Different Degrees of Polymerization

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José Rodolfo Velázquez-Martínez

2014-08-01

Full Text Available Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans have a branched structure with both β-(2→1 and β-(2→6 linked fructosyl chains attached to the sucrose start unit with a degree of polymerization (DP of up to 80 fructose units. The objective of this work was to assess the prebiotic potential of three Agave angustifolia Haw fructan fractions (AFF with different degrees of polymerization. The three fructan fractions were extracted from the agave stem by lixiviation and then purified by ultrafiltration and ion exchange chromatography: AFF1, AFF2 and AFF3 with high (3–60 fructose units, medium (2–40 and low (2–22 DP, respectively. The fructan profile was determined with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD, which confirmed a branched fructan structure. Structural elucidation was performed by Fourier Transform Infra-Red Spectroscopy. The AFF spectrum shows characteristic fructan bands. The prebiotic effect of these fractions was assessed in vitro through fermentation by Bifidobacterium and Lactobacillus strains. Four growth patterns were observed. Some bacteria did not grow with any of the AFF, while other strains grew with only AFF3. Some bacteria grew according to the molecular weight of the AFF and some grew indistinctly with the three fructan fractions.

Biofertilization of micropropagated Agave tequilana : Effect on plant ...

African Journals Online (AJOL)

Microscopic analysis showed dense root colonization in the AMF treated plants. Pal 5 treatment produced taller plants, indicating a better plant nitrogen nutrition and possibly phytohormone production by Gluconoacetobacter. Treatment Pachaz 008 presented the highest values of the most important agronomic variables, ...

The mechanical properties, deformation and thermomechanical properties of alkali treated and untreated Agave continuous fibre reinforced epoxy composites

International Nuclear Information System (INIS)

Mylsamy, K.; Rajendran, I.

2011-01-01

Research highlights: → New renewable and biodegradable Agave americana fibre. → Environmentally free materials. → Good mechanical properties of Agave fibre reinforced epoxy composite materials. → Surface modification of the fibre (Alkali treatment) imported good mechanical properties. → Future scope in light weight materials manufacture. -- Abstract: The mechanical properties such as tensile, compressive, flexural, impact strength and water absorption of the alkali treated continuous Agave fibre reinforced epoxy composite (TCEC) and untreated continuous Agave fibre reinforced epoxy composite (UTCEC) were analysed. A comparison of the surfaces of TCEC and UTCEC composites was carried out by dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermomechanical properties of the composite reinforced with sodium hydroxide (NaOH) treated Agave fibres were considerably good as the shrinkage of the fibre during alkali treatment had facilitated more points of fibre resin interface. The SEM micrograph and FTIR spectra of the impact fracture surfaces of TCEC clearly demonstrate the better interfacial adhesion between fibre and the matrix. In both analyses the TCEC gave good performance than UTCEC and, thus, there is a scope for its application in light weight manufacture in future.

Agave nonwovens in polypropylene composites: mechanical and thermal studies

CSIR Research Space (South Africa)

John, MJ

2015-03-01

Full Text Available Blends of agave fibres with wool waste, pineapple leaf fibres and polypropylene fibres were manufactured by needle-punching technique. Composites were prepared with polypropylene matrix by the process of compression moulding. The effects of blend...

Presence and distribution of two sub-species of Eurema agave (Lepidoptera, Pieridae in Costa Rica

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Jim Cordoba-Alfaro

2011-06-01

Full Text Available Austin (1992 reported Eurema a. agave (Cramer 1775 to the Caribbean of Costa Rica. However, he actually had found E. a. millerorum, described by Bousquets & Luis-Martinez (1987 for the Caribbean of Mexico. The presence of Eurema a. agave is confirmed on this paper with information of specimens collected in the Pacific and Atlantic slopes of Costa Rica. Aspects on distribution of both subspecies are included.

Variability in Saponin Content, Cancer Antiproliferative Activity and Physicochemical Properties of Concentrated Agave Sap.

Science.gov (United States)

Santos-Zea, Liliana; Rosas-Pérez, Aratza Mireya; Leal-Díaz, Ana María; Gutiérrez-Uribe, Janet A

2016-08-01

Concentrated agave sap (CAS) has gained popularity as an unrefined sweetener. It is obtained by boiling "aguamiel" that contains phytochemicals with diverse bioactivities. Saponins have been the most widely studied agave phytochemicals due to their cancer antiproliferative effect but their concentration may vary due to maturity of the agave plant and collection site. In this study, 18 CAS samples produced in different states of Mexico were analyzed using multivariate methods to determine which physicochemical or phytochemical parameters were responsible for variation. Additionally, extracts with different saponin profiles were tested to determine possible correlations with antiproliferative activity. Total soluble solids, pH, and water activity were similar to those reported for other agave sweeteners. Antioxidant capacity of samples was correlated to browning index. Eleven steroidal saponins were found in CAS samples and they were the main source of variability. Magueyoside B, a kammogenin tetraglycoside, was the most abundant saponin in all samples. With respect to bioactivity, multivariate analysis indicated that magueyoside B and a gentrogenin tetraglycoside were compounds strongly related with bioactivity. CAS from Hidalgo, Puebla, and Veracruz had higher concentration of magueyoside B than from the other kamogenin tetraglycoside found in the samples from other Mexican states. These results could be used as a first approach to characterize and standardize CAS to validate the potential health benefits derived from its consumption. © 2016 Institute of Food Technologists®

VALORIZACIÓN DE RESIDUOS AGROINDUSTRIALES DEL TEQUILA PARA ALIMENTACION DE RUMIANTES

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Clementina R. Ramírez-Cortina

2012-01-01

Full Text Available El objetivo de este trabajo fue investigar una tecnología adecuada para el uso del bagazo de Agave tequilana W. var. azul en raciones alimenticias para rumiantes. Las características físicas y químicas del bagazo fueron evaluadas. De acuerdo con dichas caracterizaciones, éste puede ser utilizado como complemento en la alimentación de rumiantes. Sin embargo, un inconveniente es la baja digestibilidad del bagazo, debido a su alto contenido de lignina; para disminuirlo se usó un tratamiento con hidróxido de calcio. El tratamiento químico se realizó en un reactor de vidrio (50 L con las siguientes condiciones: concentraciones de Ca(OH2 de 2, 5 y 10 %, humedad del bagazo de 20 y 80 %, temperaturas de 30 y 50 °C. Las pruebas de digestibilidad se realizaron en el bagazo tratado químicamente. La digestibilidad aumentó de 36 % (bagazo no tratado a 54.5 % con el mejor tratamiento (humedad 80 %, Ca(OH2 10 %, y 50 °C. Con base en los resultados de digestibilidad, se puede concluir que el bagazo tratado con Ca(OH2 puede ser utilizado como suplemento en la composición de las raciones alimenticias de los rumiantes.

Seed treatment with an aqueous extract of Agave sisalana improves seed health and seedling growth of sorghum

DEFF Research Database (Denmark)

Andresen, Marianne; Wulff, Ednar Gadelha; Mbega, Ernest R.

2015-01-01

An aqueous extract of the sisal agave, A. sisalana, was prepared from dried stem tissue by boiling in water. The sisal extract (SE) displayed a broad inhibition of the seed-borne mycoflora when applied to farmer-saved seeds of Sorghum bicolor. Species of Fusarium (belonging to the Gibberella......-old plants (p agave, Yucca schidigera. Both extracts were found to reduce seed-borne Fusarium and crown rot more efficiently than fungicides based on tebuconazole, enilconazole...... and fludioxonil (p agave is a waste product in fiber production. From our findings A. sisalana stem appears to represent an abundant source of antifungal activity, simple to extract, easy to store and with a promising potential in biological seed treatment....

Cytotoxic activity of Agave lechuguilla Torr | Casillas | African ...

African Journals Online (AJOL)

The cytotoxic activity of extract and isolated saponin from leaves of Agave lechuguilla was investigated. Ethanol extract from leaves of A. lechuguilla exhibited cytotoxic activity against HeLa cells in vitro (50% inhibitory concentration (IC50) = 89 μg/ml). Bioassay-guided fractionation of this extract had led to the isolation of 5-β ...

Effects of agave nectar versus sucrose on weight gain, adiposity, blood glucose, insulin, and lipid responses in mice.

Science.gov (United States)

Hooshmand, Shirin; Holloway, Brittany; Nemoseck, Tricia; Cole, Sarah; Petrisko, Yumi; Hong, Mee Young; Kern, Mark

2014-09-01

Agave nectar is a fructose-rich liquid sweetener derived from a plant, and is often promoted as a low glycemic alternative to refined sugar. However, little scientific research has been conducted in animals or humans to determine its metabolic and/or health effects. The aim of this study was to explore the influence of agave nectar versus sucrose on weight gain, adiposity, fasting plasma blood glucose, insulin, and lipid levels. Eighteen (n=18) male ICR mice (33.8±1.6 g) were divided into two groups (n=6 for agave nectar and n=12 for sucrose) and provided free access to one of two diets of equal energy densities differing only in a portion of the carbohydrate provided. Diets contained 20% carbohydrate (by weight of total diet) from either raw agave nectar or sucrose. Epididymal fat pads were excised, and blood was collected after 34 days. Weight gain (4.3±2.2 vs. 8.4±3.4 g), fat pad weights (0.95±0.54 vs. 1.75±0.66 g), plasma glucose (77.8±12.2 vs. 111.0±27.9 mg/dL), and insulin (0.61±0.29 vs. 1.46±0.81 ng/mL) were significantly lower (P≤.05) for agave nectar-fed mice compared to sucrose-fed mice respectively. No statistically significant differences in total cholesterol or triglycerides were detected. These results suggest that in comparison to sucrose, agave nectar may have a positive influence on weight gain and glucose control. However, more research with a larger sample of animals and/or with human subjects is warranted.

Environmental Assessment Report: Geotechnical Field Investigations.

Science.gov (United States)

1975-06-30

EOARGUEV NVOJOPOOLLACLAC PHACFJ,1A FILIFcjRMIS ARIZONA ENOANGEREO I4YORlOPHYLLACEAC PHACELIA WCESMIJ ARI IONA ENOA004EXD LILJACEAE AGAVE ARIZONI1CA...Jim WaliNAL.innsB-3 STATE STATUS FAM ILY SPECIES AAfrIIONA EhOANOLACU LiIACLAI, AG.AVE MCMfLV~fAhA ARIZONA t NDANCfkLu LILjActAL AGAVE !CHOTTII VAR...ARIZONA THREATENE) ONAC.NACEAL CAM15SONIA ExILI1. ARIZONA THREATENED ONAWACCAE CA,4ISSONIA PARRYI ARIZONA THREATENED ONAC.RACEAL CAMI55ONIA SPECUICOLA

Carácterización reológica de fructanos de agave y achicoria

OpenAIRE

Parra Montes de Oca, Marco Antonio

2015-01-01

Los fructanos son polímeros de fructosa que pueden modificar las propiedades reológicas del medio donde se encuentran, de tal forma que proporcionan textura y palatabilidad a los alimentos; entre estos se destaca la inulina de achicoria, ya que es el fructano más utilizado en la industria alimentaria. En México, los fructanos se obtienen principalmente de las plantas del género Agave, sin embargo, la estructura química de los fructanos de agave es diferente a la de la inulina y en consecuenci...

Characterization of Volatile Compounds from Ethnic Agave Alcoholic Beverages by Gas Chromatography-Mass Spectrometry

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Pilar Escalante-Minakata

2008-01-01

Full Text Available Ethnic Agave alcoholic beverages such as raicilla, sisal, tequila, mezcal, bacanora, sotol and pulque have been analyzed by gas chromatography and headspace solid-phase microextraction- gas chromatography-mass spectrometry (HS-SPME-GC-MS. There were 105 compounds identified, eleven were classified as major compounds and the others were classified as minor compounds. Seventeen minor compounds could be used as authenticity markers since they were beverage specific. Cluster analysis (CA showed that Agave alcoholic beverages could be distinguished by multivariate analysis of major compounds; however, the analysis of minor compounds provided a better fingerprinting.

Evaluation of Treatments to Reduce Hardness of Agave americana Core

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José A. Ramírez

2006-01-01

Full Text Available Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass or sodium hydroxide 1 % (by mass were tested and optimized. The pretreatment of the core of A. americana with sulphuric acid 1 % allowed the reduction of hardness from 30 000 g to 2000 g of breaking force. The mathematical model obtained predicts an optimum processing at 84 °C during 75 min. The treatment with sulphuric acid 1 % also allows white core of A. americana to be obtained, while the other treatments provide yellow core. These results open a good alternative to obtain value added products from this resource.

Agave Inulin Supplementation Affects the Fecal Microbiota of Healthy Adults Participating in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.

Science.gov (United States)

Holscher, Hannah D; Bauer, Laura L; Gourineni, Vishnupriya; Pelkman, Christine L; Fahey, George C; Swanson, Kelly S

2015-09-01

Prebiotics resist digestion, providing fermentable substrates for select gastrointestinal bacteria associated with health and well-being. Agave inulin differs from other inulin type fibers in chemical structure and botanical origin. Preclinical animal research suggests these differences affect bacterial utilization and physiologic outcomes. Thus, research is needed to determine whether these effects translate to healthy adults. We evaluated agave inulin utilization by the gastrointestinal microbiota by measuring fecal fermentative end products and bacterial taxa. A randomized, double-blind, placebo-controlled, 3-period, crossover trial was undertaken in healthy adults (n = 29). Participants consumed 0, 5.0, or 7.5 g agave inulin/d for 21 d with 7-d washouts between periods. Participants recorded daily dietary intake; fecal samples were collected during days 16-20 of each period and were subjected to fermentative end product analysis and 16S Illumina sequencing. Fecal Actinobacteria and Bifidobacterium were enriched (P inulin/d, respectively, compared with control. Desulfovibrio were depleted 40% with agave inulin compared with control. Agave inulin tended (P inulin (g/kcal) and Bifidobacterium (r = 0.41, P inulin/d) per kilocalorie was positively associated with fecal butyrate (r = 0.30, P = 0.005), tended to be positively associated with Bifidobacterium (r = 0.19, P = 0.08), and was negatively correlated with Desulfovibrio abundance (r = -0.31, P = 0.004). Agave inulin supplementation shifted the gastrointestinal microbiota composition and activity in healthy adults. Further investigation is warranted to determine whether the observed changes translate into health benefits in human populations. This trial was registered at clinicaltrials.gov as NCT01925560. © 2015 American Society for Nutrition.

Quail egg yield and quality of the Coturnix coturnix response to the addition level of agave inulin to the drinking water

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Luis Jorge Pérez de la Mora

2014-05-01

Full Text Available To assess the effect of agave inulin addition to drinking water, one hundred (65 days old Coturnix coturnix japonica hens were divided randomly into four groups with five birds per cage. Twenty five birds were assigned to each of the following treatments: i control; addition of agave inulin in the drinking water at; ii 2.0% (w/w, iii 4.0%; and iv 6%. The feeding trial lasted for six weeks. Inulin increased (P0.05. The egg weight was similar among treatments (average 12.70 g and varied slightly with the inulin level (P=0.0537. The egg shell (percentage of the egg was not influenced by the inulin. But, the calcium concentration in the eggshell of the present trial varied with the level on the agave inulin in the drinking water (P0.05. Then, the agave inulin addition to the drinking water increases the egg yield of Japanese quails.

In vitro evaluation of the effect of aqueous extracts of Agave sisalana ...

African Journals Online (AJOL)

SARAH

2015-05-30

May 30, 2015 ... inhibitory concentration (MIC) of Agave sisalana extracts was 3% (PI ≤ 97%).For the C. citratus ... posts, lumbar support belts, rugs, slippers, and cloths (FAO .... statistical analysis revealed statistically significant differences ...

Measurement of the CP-violation parameter Re(var-epsilon '/var-epsilon)

International Nuclear Information System (INIS)

Gibbons, L.K.; Barker, A.R.; Briere, R.A.; Makoff, G.; Papadimitriou, V.; Patterson, J.R.; Schwingenheuer, B.; Somalwar, S.V.; Wah, Y.W.; Winstein, B.; Winston, R.; Woods, M.; Yamamoto, H.; Swallow, E.C.; Bock, G.J.; Coleman, R.; Enagonio, J.; Hsiung, Y.B.; Ramberg, E.; Stanfield, K.; Tschirhart, R.; Yamanaka, T.; Gollin, G.D.; Karlsson, M.; Okamitsu, J.K.; Debu, P.; Peyaud, B.; Turlay, R.; Vallage, B.

1993-01-01

A measurement of the CP-violation parameter Re(var-epsilon '/var-epsilon) has been made using the full E731 data set. We find Re(var-epsilon '/var-epsilon)=(7.4±5.2±2.9)x10 -4 where the first error is statistical and the second systematic

Vulnerability and risk management of Agave species in the Tehuacán Valley, México.

Science.gov (United States)

Delgado-Lemus, América; Torres, Ignacio; Blancas, José; Casas, Alejandro

2014-07-03

Our study analysed the vulnerability of the useful Agave species of the Tehuacán Valley, Mexico, considering ecological, cultural and economic aspects, and management types. We hypothesized that management intensity is proportional to the degree of risk of a species in order to decrease its vulnerability. Distribution of Agave species was monitored in 36 types of plant associations. Ethnobotanical studies were conducted in 13 villages and six markets. The vulnerability of each species was calculated by assigning risk values to the variables analysed. The vulnerability and management intensity indexes were estimated through the scores of the first principal component of PCA. Variation of management data explained by ecological, cultural and economic information were analysed through canonical correspondence analyses (CCA). A linear regression analysis identified the relation between vulnerability and management intensity. We recorded presence of agave species in 20 of 36 vegetation types. Out of 34 Agave species, 28 were recorded to have one to 16 use types; 16 species are used as food, 13 for live fences, 13 for producing 'pulque', 11 for fibre and ornamental, 9 for construction. Seven species are used for preparing mescal, activity representing the highest risk. Seven Agave species are exclusively extracted from the wild and the others receive some management type. Incipient cultivation was identified in A. potatorum whose seedlings are grown in nurseries. Intensive cultivation through vegetative propagation occurs with domesticated species of wide distribution in Mexico. The highest management intensity values were recorded in widely distributed, cultivated and domesticated species, but the regionally native species more intensively managed were those with higher demand and economic value, protected by collective regulations because of their scarcity. The regression analysis indicated significant relation (R2=0.677, P<0.001) between vulnerability and management

Novel microsatellite loci for Agave parryi and cross-amplification in Agave palmeri (Agavaceae).

Science.gov (United States)

Lindsay, Denise L; Edwards, Christine E; Jung, Michael G; Bailey, Pamela; Lance, Richard F

2012-07-01

To examine the foraging behavior of nectarivorous bats in southeastern Arizona, we developed microsatellite primers in Agave parryi. These markers were also tested for cross-amplification and applicability to assess patterns of genetic diversity and structure in A. palmeri. Utilizing DNA sequence data from 454 shotgun sequencing, we identified seven novel polymorphic microsatellite loci in A. parryi and screened them for cross-amplification in A. palmeri. These markers were characterized in two populations of 30 individuals each for each species. In A. parryi, all primers were polymorphic and amplified between three and 12 alleles per population. In A. palmeri, all primers amplified, six were polymorphic, and allelic diversity ranged from one to 16 alleles per population. Our results demonstrate the applicability of these microsatellite primers for population genetics studies in both A. parryi and A. palmeri.

arXiv Observation of the $\\varXi^{-}_{b}\\to J/\\psi\\varLambda K^{-}$ decay

CERN Document Server

Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Bordyuzhin, Igor; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kosmyntseva, Alena; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Tenglin; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevens, Holger; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

2017-09-10

The observation of the decay $\\varXi_{b}^{-}\\to J/\\psi\\varLambda K^{-}$ is reported, using a data sample corresponding to an integrated luminosity of $3~\\mathrm{fb}^{-1}$, collected by the LHCb detector in $pp$ collisions at centre-of-mass energies of $7$ and $8~\\mathrm{TeV}$. The production rate of $\\varXi_{b}^{-}$ baryons detected in the decay $\\varXi_{b}^{-}\\to J/\\psi\\varLambda K^{-}$ is measured relative to that of $\\varLambda_{b}^{0}$ baryons using the decay $\\varLambda_{b}^{0}\\to J/\\psi \\varLambda$. Integrated over the $b$-baryon transverse momentum $p_{\\rm T}<25~\\mathrm{GeV/}c $ and rapidity $2.0 < y < 4.5$, the measured ratio is \\begin{equation*} \\frac{f_{\\varXi_{b}^{-}}}{f_{\\varLambda_{b}^{0}}}\\frac{\\mathcal{B}(\\varXi_{b}^{-}\\to J/\\psi\\varLambda K^{-})}{\\mathcal{B}(\\varLambda_{b}^{0}\\to J/\\psi \\varLambda)}=(4.19\\pm 0.29~(\\mathrm{stat})\\pm0.14~(\\mathrm{syst}))\\times 10^{-2}, \\end{equation*}where $f_{\\varXi_{b}^{-}}$ and $f_{\\varLambda_{b}^{0}}$ are the fragmentation fractions of $b\\to\\varXi_{...

Agave salmiana Plant Communities in Central Mexico as Affected by Commercial Use

Science.gov (United States)

Martínez Salvador, Martin; Mata-González, Ricardo; Morales Nieto, Carlos; Valdez-Cepeda, Ricardo

2012-01-01

Agave salmiana is a native plant species harvested for the commercial production of mezcal ( Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha-1) in the short-use areas and less (892 plants ha-1) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha-1) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).

Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

Directory of Open Access Journals (Sweden)

Neyser De La Torre-Ruiz

Full Text Available ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA, solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p < 0.05 on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop1[OPEN

Science.gov (United States)

Shivhare, Devendra

2017-01-01

To maintain metabolic flux through the Calvin-Benson-Bassham cycle in higher plants, dead-end inhibited complexes of Rubisco must constantly be engaged and remodeled by the molecular chaperone Rubisco activase (Rca). In C3 plants, the thermolability of Rca is responsible for the deactivation of Rubisco and reduction of photosynthesis at moderately elevated temperatures. We reasoned that crassulacean acid metabolism (CAM) plants must possess thermostable Rca to support Calvin-Benson-Bassham cycle flux during the day when stomata are closed. A comparative biochemical characterization of rice (Oryza sativa) and Agave tequilana Rca isoforms demonstrated that the CAM Rca isoforms are approximately10°C more thermostable than the C3 isoforms. Agave Rca also possessed a much higher in vitro biochemical activity, even at low assay temperatures. Mixtures of rice and agave Rca form functional hetero-oligomers in vitro, but only the rice isoforms denature at nonpermissive temperatures. The high thermostability and activity of agave Rca mapped to the N-terminal 244 residues. A Glu-217-Gln amino acid substitution was found to confer high Rca activity to rice Rca. Further mutational analysis suggested that Glu-217 restricts the flexibility of the α4-β4 surface loop that interacts with Rubisco via Lys-216. CAM plants thus promise to be a source of highly functional, thermostable Rca candidates for thermal fortification of crop photosynthesis. Careful characterization of their properties will likely reveal further protein-protein interaction motifs to enrich our mechanistic model of Rca function. PMID:28546437

In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop.

Science.gov (United States)

Shivhare, Devendra; Mueller-Cajar, Oliver

2017-07-01

To maintain metabolic flux through the Calvin-Benson-Bassham cycle in higher plants, dead-end inhibited complexes of Rubisco must constantly be engaged and remodeled by the molecular chaperone Rubisco activase (Rca). In C3 plants, the thermolability of Rca is responsible for the deactivation of Rubisco and reduction of photosynthesis at moderately elevated temperatures. We reasoned that crassulacean acid metabolism (CAM) plants must possess thermostable Rca to support Calvin-Benson-Bassham cycle flux during the day when stomata are closed. A comparative biochemical characterization of rice ( Oryza sativa ) and Agave tequilana Rca isoforms demonstrated that the CAM Rca isoforms are approximately10°C more thermostable than the C3 isoforms. Agave Rca also possessed a much higher in vitro biochemical activity, even at low assay temperatures. Mixtures of rice and agave Rca form functional hetero-oligomers in vitro, but only the rice isoforms denature at nonpermissive temperatures. The high thermostability and activity of agave Rca mapped to the N-terminal 244 residues. A Glu-217-Gln amino acid substitution was found to confer high Rca activity to rice Rca Further mutational analysis suggested that Glu-217 restricts the flexibility of the α4-β4 surface loop that interacts with Rubisco via Lys-216. CAM plants thus promise to be a source of highly functional, thermostable Rca candidates for thermal fortification of crop photosynthesis. Careful characterization of their properties will likely reveal further protein-protein interaction motifs to enrich our mechanistic model of Rca function. © 2017 American Society of Plant Biologists. All Rights Reserved.

Molecular and morphological tools to distinguish Scyphophorus acupunctatus Gyllenhal, 1838: a new weevil pest of the endangered Eggers Agave from St Croix, US Virgin Islands

Science.gov (United States)

The Agave Snout Weevil (ASW) or Sisal Weevil, Scyphophorus acupunctatus Gyllenhal, is one of the most destructive pests of agave plants, capable of destroying up to 70% of commercial crops, costing millions of dollars in damage to global industries including tequila, mezcal, perfume, henequen, nardo...

Inferring ancient Agave cultivation practices from contemporary genetic patterns.

Science.gov (United States)

Parker, Kathleen C; Trapnell, Dorset W; Hamrick, J L; Hodgson, Wendy C; Parker, Albert J

2010-04-01

Several Agave species have played an important ethnobotanical role since prehistory in Mesoamerica and semiarid areas to the north, including central Arizona. We examined genetic variation in relict Agave parryi populations northeast of the Mogollon Rim in Arizona, remnants from anthropogenic manipulation over 600 years ago. We used both allozymes and microsatellites to compare genetic variability and structure in anthropogenically manipulated populations with putative wild populations, to assess whether they were actively cultivated or the result of inadvertent manipulation, and to determine probable source locations for anthropogenic populations. Wild populations were more genetically diverse than anthropogenic populations, with greater expected heterozygosity, polymorphic loci, effective number of alleles and allelic richness. Anthropogenic populations exhibited many traits indicative of past active cultivation: fixed heterozygosity for several loci in all populations (nonexistent in wild populations); fewer multilocus genotypes, which differed by fewer alleles; and greater differentiation among populations than was characteristic of wild populations. Furthermore, manipulated populations date from a period when changes in the cultural context may have favoured active cultivation near dwellings. Patterns of genetic similarity among populations suggest a complex anthropogenic history. Anthropogenic populations were not simply derived from the closest wild A. parryi stock; instead they evidently came from more distant, often more diverse, wild populations, perhaps obtained through trade networks in existence at the time of cultivation.

Propiedades químicas, estructurales y funcionales de la lechuguilla (Agave lechuguilla Torr.)

DEFF Research Database (Denmark)

Carmona, Juan E.; Morales-Martínez, Thelma K.; Mussatto, Solange I.

2017-01-01

Agave lechuguilla Torr. Is a non-timber forest resource in the arid and semi-arid zones of northeastern Mexico, due to its range of distribution, it is interesting to evaluate the potential of this raw material for biotechnological applications such as the production of second generation biofuels...

Distribution, abundance and traditional management of Agave potatorum in the Tehuacán Valley, Mexico: bases for sustainable use of non-timber forest products.

Science.gov (United States)

Delgado-Lemus, América; Casas, Alejandro; Téllez, Oswaldo

2014-09-03

Agave species have been used for thousands of years in the Tehuacán Valley, but the current mescal production has great impact on populations of the most used species. Harvesting of A. potatorum takes place before sexual reproduction and the over-extraction put local populations at high risk. In the community of San Luis Atolotilán (SLA), mescal has been produced for one century but the growing mescal trade is leading to intensified agave extraction. Our study evaluated distribution and abundance of A. potatorum, extraction rates, management practices and economic importance for SLA households. The unbalanced relation between availability and extraction rates would be an indicator of risk requiring sustainable management strategies. Our case study aspires contributing to analyze general patterns for sustainable use for this and other forest products highly extracted. We used bioclimatic modeling to project a map of potential distribution of the species, and ecological sampling to estimate the total availability of harvestable agaves within the territory of SLA. We used participant observation, surveys and semi-structured interviews with producers and households of SLA to document agave uses, technological and socio-economic aspects of mescal production, and to estimate extraction rates of agaves. Mescal production, medicine and fodder are the most important uses of A. potatorum. Its distribution area is nearly 608 ha where annually occur on average 7,296 harvestable plants, nearly 54 to 87% of them being harvested. Mescal production currently is a non-sustainable activity, requiring great changes in patterns of extraction and management adopting sustainable criteria. Local people started management planning to ensure the future availability of agaves, and the ecological information of this study has been helpful in constructing their decisions. Technical support for improving local experiences for managing populations' recovering is a priority. Interaction of

Identification of yeast and bacteria involved in the mezcal fermentation of Agave salmiana.

Science.gov (United States)

Escalante-Minakata, P; Blaschek, H P; Barba de la Rosa, A P; Santos, L; De León-Rodríguez, A

2008-06-01

To identify the yeast and bacteria present in the mezcal fermentation from Agave salmiana. The restriction and sequence analysis of the amplified region, between 18S and 28S rDNA and 16S rDNA genes, were used for the identification of yeast and bacteria, respectively. Eleven different micro-organisms were identified in the mezcal fermentation. Three of them were the following yeast: Clavispora lusitaniae, Pichia fermentans and Kluyveromyces marxianus. The bacteria found were Zymomonas mobilis subsp. mobilis and Zymomonas mobilis subsp. pomaceae, Weissella cibaria, Weissella paramesenteroides, Lactobacillus pontis, Lactobacillus kefiri, Lactobacillus plantarum and Lactobacillus farraginis. The phylogenetic analysis of 16S rDNA and ITS sequences showed that microbial diversity present in mezcal is dominated by bacteria, mainly lactic acid bacteria species and Zymomonas mobilis. Pichia fermentans and K. marxianus could be micro-organisms with high potential for the production of some volatile compounds in mezcal. We identified the community of bacteria and yeast present in mezcal fermentation from Agave salmiana.

In vitro evaluation of the effect of aqueous extracts of Agave sisalana ...

African Journals Online (AJOL)

Objectives: To evaluate the effects of aqueous extracts of Agave sisalana (sisal) and Cymbopogon citratus (lemon grass) on mycelial growth and conidia production of Pyricularia oryzae, causal agent of Rice Blast. Methodology and Results: The plants aqueous extracts were used at concentrations 0.1; 0.2; 0.3; 0.4; 0.5;1; 2; ...

Synthesis of silver nanoparticles using aqueous extracts of Heterotheca inuloides as reducing agent and natural fibers as templates: Agave lechuguilla and silk

Energy Technology Data Exchange (ETDEWEB)

Morales-Luckie, Raúl A., E-mail: rmoralesl@uaemex.mx [Universidad Autónoma del Estado de México, Centro Conjunto de Investigación en Quı́mica Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, San Cayetano, 50200 Toluca, Estado de México (Mexico); Lopezfuentes-Ruiz, Aldo Adrián; Olea-Mejía, Oscar F.; Liliana, Argueta-Figueroa [Universidad Autónoma del Estado de México, Centro Conjunto de Investigación en Quı́mica Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, San Cayetano, 50200 Toluca, Estado de México (Mexico); Sanchez-Mendieta, Víctor [Facultad de Química, Universidad Autónoma del Estado de México. Paseo Colón y Paseo Tollocan, Toluca, Estado de México 50120 (Mexico); Brostow, Witold [Laboratory of Advanced Polymers & Optimized Materials (LAPOM), Department of Materials Science and Engineering, University of North Texas, 1150 Union Circle #305310, Denton, TX (United States); Hinestroza, Juan P. [Department of Fiber Science and Apparel Design, Cornell University, 242 Van Rensselaer Hall, Ithaca, New York 14853-4203 (United States)

2016-12-01

Silver nanoparticles (Ag NPs) were synthesized using a one-pot green methodology with aqueous extract of Heterotheca inuloides as a reducing agent, and the support of natural fibers: Agave lechuguilla and silk. UV–Vis spectroscopy, X-Ray photoelectron spectroscopy XPS and transmission electron microscopy TEM were used to characterize the resulting bionanocomposite fibers. The average size of the Ag NPs was 16 nm and they exhibited low polydispersity. XPS studies revealed the presence of only metallic Ag in the nanoparticles embedded in Agave. lechuguilla fibers. Significant antibacterial activities against gram-negative Escherichia coli and gram-positive Staphylococcus aureus were determined. AgO as well as metallic Ag phases were detected when silk threads were used as a substrates hinting at the active role of substrate during the nucleation and growth of Ag NPs. These bionanocomposites have excellent mechanical properties in tension which in addition to the antibacterial properties indicate the potential use of these modified natural fibers in surgical and biomedical applications. - Highlights: • Heterotheca inuloides was used to synthesize Ag NPs on Agave lechuguilla and silk fibers. • Both threads bearing Ag NPs show antibacterial activity against gram(+) and gram(−) bacteria. • The mechanical properties of Agave lechuguilla and silk threads bearing Ag NPs are improved.

IN VITRO CYTOTOXICITY STUDY OF AGAVE AMERICANA, STRYCHNOS NUX-VOMICA AND ARECA CATECHU EXTRACTS USING MCF-7 CELL LINE

Directory of Open Access Journals (Sweden)

Anajwala Chetan C.

2010-06-01

Full Text Available Research is focusing on the search for new types of natural chemotherapeutic agent that is plant based medicines which are proving to be excellent sources of new compounds. In present research study, an attempt was made to prove cytotoxicity activity of various parts of medicinal plants such as Agave americana, Strychnos nux-vomica and Areca catechu using MCF-7 and Vero cell line. Various parts of the medicinal plants were extracted by soxhlet apparatus using solvents likes methanol and water. By trypan blue dye exclusion method, Viability of MCF-7 and Vero cell lines were 85.50 and 81.13%, respectively. IC50 value of methanol extract of Agave americana leaves and aqueous extract of Areca catechu fruits were found to be 545.9 & 826.1 µg/ml by SRB assay and 775.1 & 1461µg/ml by MTT assay, respectively, against MCF-7 cell line. From cytotoxicity study data by SRB and MTT assay, it revealed that methanol extract of Agave americana and aqueous extract of Areca catechu are potent cytotoxic.

Weinig VVT-instellingen met VAR : onderzoek naar VAR's in Nederland

NARCIS (Netherlands)

Corina de Feijter; Pieterbas Lalleman

V&VN is op zoek gegaan naar alle actieve Verpleegkundige en/of Verzorgende Adviesraden (VAR) in Nederland. Het blijkt dat in totaal 144 zorginstellingen (24%) een VAR hebben. Vooral in de VVT-sector is het aantal VAR’s laag: 13%.

Yeast communities associated with artisanal mezcal fermentations from Agave salmiana.

Science.gov (United States)

Verdugo Valdez, A; Segura Garcia, L; Kirchmayr, M; Ramírez Rodríguez, P; González Esquinca, A; Coria, R; Gschaedler Mathis, A

2011-11-01

The aims of this work were to characterize the fermentation process of mezcal from San Luis Potosi, México and identify the yeasts present in the fermentation using molecular culture-dependent methods (RFLP of the 5.8S-ITS and sequencing of the D1/D2 domain) and also by using a culture-independent method (DGGE). The alcoholic fermentations of two separate musts obtained from Agave salmiana were analyzed. Sugar, ethanol and major volatile compounds concentrations were higher in the first fermentation, which shows the importance of having a quality standard for raw materials, particularly in the concentration of fructans, in order to produce fermented Agave salmiana must with similar characteristics. One hundred ninety-two (192) different yeast colonies were identified, from those present on WL agar plates, by RFLP analysis of the ITS1-5.8S- ITS2 from the rRNA gene, with restriction endonucleases, HhaI, HaeIII and HinfI. The identified yeasts were: Saccharomyces cerevisiae, Kluyveromyces marxianus, Pichia kluyveri, Zygosaccharomyces bailii, Clavispora lusitaniae, Torulaspora delbrueckii, Candida ethanolica and Saccharomyces exiguus. These identifications were confirmed by sequencing the D1-D2 region of the 26S rRNA gene. With the PCR-DGGE method, bands corresponding to S. cerevisiae, K. marxianus and T. delbrueckii were clearly detected, confirming the results obtained with classic techniques.

Water Absorption and Thermomechanical Characterization of Extruded Starch/Poly(lactic acid/Agave Bagasse Fiber Bioplastic Composites

Directory of Open Access Journals (Sweden)

F. J. Aranda-García

2015-01-01

Full Text Available Water absorption and thermomechanical behavior of composites based on thermoplastic starch (TPS are presented in this work, wherein the concentration of agave bagasse fibers (ABF, 0–15 wt% and poly(lactic acid (PLA, 0–30 wt% is varied. Glycerol (G is used as starch (S plasticizer to form TPS. Starch stands as the polymer matrix (70/30 wt/wt, S/G. The results show that TPS hygroscopicity decreases as PLA and fiber content increase. Storage, stress-strain, and flexural moduli increase with PLA and/or agave bagasse fibers (ABF content while impact resistance decreases. The TPS glass transition temperature increases with ABF content and decreases with PLA content. Micrographs of the studied biocomposites show a stratified brittle surface with a rigid fiber fracture.

New var reconstruction algorithm exposes high var sequence diversity in a single geographic location in Mali.

Science.gov (United States)

Dara, Antoine; Drábek, Elliott F; Travassos, Mark A; Moser, Kara A; Delcher, Arthur L; Su, Qi; Hostelley, Timothy; Coulibaly, Drissa; Daou, Modibo; Dembele, Ahmadou; Diarra, Issa; Kone, Abdoulaye K; Kouriba, Bourema; Laurens, Matthew B; Niangaly, Amadou; Traore, Karim; Tolo, Youssouf; Fraser, Claire M; Thera, Mahamadou A; Djimde, Abdoulaye A; Doumbo, Ogobara K; Plowe, Christopher V; Silva, Joana C

2017-03-28

Encoded by the var gene family, highly variable Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) proteins mediate tissue-specific cytoadherence of infected erythrocytes, resulting in immune evasion and severe malaria disease. Sequencing and assembling the 40-60 var gene complement for individual infections has been notoriously difficult, impeding molecular epidemiological studies and the assessment of particular var elements as subunit vaccine candidates. We developed and validated a novel algorithm, Exon-Targeted Hybrid Assembly (ETHA), to perform targeted assembly of var gene sequences, based on a combination of Pacific Biosciences and Illumina data. Using ETHA, we characterized the repertoire of var genes in 12 samples from uncomplicated malaria infections in children from a single Malian village and showed them to be as genetically diverse as vars from isolates from around the globe. The gene var2csa, a member of the var family associated with placental malaria pathogenesis, was present in each genome, as were vars previously associated with severe malaria. ETHA, a tool to discover novel var sequences from clinical samples, will aid the understanding of malaria pathogenesis and inform the design of malaria vaccines based on PfEMP1. ETHA is available at: https://sourceforge.net/projects/etha/ .

Eddy covariance measurements of net C exchange in the CAM bioenergy crop, Agave tequiliana

Science.gov (United States)

Owen, Nick A.; Choncubhair, Órlaith Ní; Males, Jamie; del Real Laborde, José Ignacio; Rubio-Cortés, Ramón; Griffiths, Howard; Lanigan, Gary

2016-04-01

Bioenergy crop cultivation may focus more on low grade and marginal lands in order to avoid competition with food production for land and water resources. However, in many regions, this would require improvements in plant water-use efficiency that are beyond the physiological capacity of most C3 and C4 bioenergy crop candidates. Crassulacean acid metabolism (CAM) plants, such as Agave tequiliana, can combine high above-ground productivity with as little as 20% of the water demand of C3 and C4 crops. This is achieved through temporal separation of carboxylase activities, with stomata opening at night to allow gas exchange and minimise transpirational losses. Previous studies have employed 'bottom-up' methodologies to investigate carbon (C) accumulation and productivity in Agave, by scaling leaf-level gas exchange and titratable acidity (TA) with leaf area index or maximum productivity. We used the eddy covariance (EC) technique to quantify ecosystem-scale gas exchange over an Agave plantation in Mexico ('top-down' approach). Measurements were made over 252 days, including the transition from wet to dry periods. Results were cross-validated against diel changes in titratable acidity, leaf-unfurling rates, energy exchange fluxes and reported biomass yields. Net ecosystem exchange of CO2 displayed a CAM rhythm that alternated from a net C sink at night to a net C source during the day and partitioned canopy fluxes (gross C assimilation, FA,EC) showed a characteristic four-phase CO2 exchange pattern. The projected ecosystem C balance indicated that the site was a net sink of -333 ± 24 g C m-2 y-1, comprising cumulative soil respiration of 692 ± 7 g C m-2 y-1 and FA,EC of -1025 ± 25 g C m-2 y-1. EC-estimated biomass yield was 20.1 Mg ha-1 y-1. Average integrated daily FA,EC was -234 ± 5 mmol CO2 m-2 d-1 and persisted almost unchanged after 70 days of drought conditions. Our results suggest that the carbon acquisition strategy of drought avoidance employed by Agave

The uses of AFLP for detecting DNA polymorphism, genotype identification and genetic diversity between yeasts isolated from Mexican agave-distilled beverages and from grape musts.

Science.gov (United States)

Flores Berrios, E P; Alba González, J F; Arrizon Gaviño, J P; Romano, P; Capece, A; Gschaedler Mathis, A

2005-01-01

The objectives were to determine the variability and to compare the genetic diversity obtained using amplified fragment length polymorphism (AFLP) markers in analyses of wine, tequila, mezcal, sotol and raicilla yeasts. A molecular characterization of yeasts isolated from Mexican agave musts, has been performed by AFLP marker analysis, using reference wine strains from Italian and South African regions. A direct co-relation between genetic profile, origin and fermentation process of strains was found especially in strains isolated from agave must. In addition, unique molecular markers were obtained for all the strains using six combination primers, confirming the discriminatory power of AFLP markers. This is the first report of molecular characterization between yeasts isolated from different Mexican traditional agave-distilled beverages, which shows high genetic differences with respect to wine strains.

Delice(Olea europea var. oleaster L.) ile zeytin (Olea europea var.sativa) arasında anatomik ve palinojik ayrıcalıklar (The Anatomic And Palynological Differences Between Olea europea var. oleaster L. AND Olea europea var.sativa)

OpenAIRE

Kaya, Zafer

1991-01-01

Delice(Olea europea var. oleaster L.) ile zeytin (Olea europea var.sativa) arasında anatomik ve palinojik ayrıcalıklar (The Anatomic And Palynological Differences Between Olea europea var. oleaster L. AND Olea europea var.sativa)

Effect of prebiotics of Agave salmiana fed to healthy Wistar rats.

Science.gov (United States)

Jasso-Padilla, Iliana; Juárez-Flores, Bertha; Alvarez-Fuentes, Gregorio; De la Cruz-Martínez, Alejandro; González-Ramírez, José; Moscosa-Santillán, Mario; González-Chávez, Marco; Oros-Ovalle, Cuauhtemoc; Prell, Florian; Czermak, Peter; Martinez-Gutierrez, Fidel

2017-01-01

Inulin and other fructans are synthesized and stored in mezcal agave (Agave salmiana). Fructans provide several health benefits and have excellent technological properties, but only few data report their physiological effect when added in the diet. Here, we studied the physiological effects of fructans obtained from A. salmiana when added in the diet of Wistar rats. Results showed favorable changes on Wistar rats when the fructans was added to their diet, including the decrease of the pH in the feces and the increase of the number of lactic acid bacteria (CFU g -1 ) (Lactobacillus spp. and Bifidobacterium spp.), even these changes were enhanced with the synbiotic diet (fructans plus B. animalis subsp. lactis). Synbiotic diet, developed changes in the reduction of cholesterol and triglycerides concentrations in serum, with statistical differences (P < 0.05). Histological analysis of colon sections showed that synbiotic diet promoted colon cells growth suggesting that fructans from A. salmiana confer beneficial health effects through gut microbiota modulation. Our data underline the advantage of targeting the gut microbiota by colonic nutrients like specific structure of fructans from A. salmiana, with their beneficial effects. More studies are necessary to define the role of fructans to develop more solid therapeutic solutions in humans. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

78 FR 62560 - Endangered and Threatened Wildlife and Plants; Endangered Status for Agave eggersiana and...

Science.gov (United States)

2013-10-22

..., 1980, Agave eggersiana, Gonocalyx concolor, and Varronia rupicola (as Cordia rupicola) were identified... Federal Register a CNOR (64 FR 57535) that added Gonocalyx concolor and Varronia rupicola (as Cordia... rupicola (as Cordia rupicola) was assigned an LPN of 2 because it faced threats of a high magnitude that...

Kinetic study of the thermal hydrolysis of Agave salmiana for mezcal production.

Science.gov (United States)

Garcia-Soto, M J; Jimenez-Islas, H; Navarrete-Bolanos, J L; Rico-Martinez, R; Miranda-Lopez, R; Botello-Alvarez, J E

2011-07-13

The kinetics of the thermal hydrolysis of the fructans of Agave salmiana were determined during the cooking step of mezcal production in a pilot autoclave. Thermal hydrolysis was achieved at different temperatures and cooking times, ranging from 96 to 116 °C and from 20 to 80 h. A simple kinetic model of the depolymerization of fructans to monomers and other reducing sugars and of the degradation of reducing sugars to furans [principally 5-(hydroxymethyl)furfural, HMF] was developed. From this model, the rate constants of the reactions were calculated, as well as the pre-exponential factors and activation energies of the Arrhenius equation. The model was found to fit the experimental data well. The tradeoff between a maximum fructan hydrolysis and a critical furan concentration in allowing for the best ethanol yield during fermentation was investigated. The results indicated that the thermal hydrolysis of agave was optimal, from the point of view of ethanol yield in the ensuing fermentation, in the temperature range of 106-116 °C and the cooking range time of 6-14 h. The optimal conditions corresponded to a fructan hydrolysis of 80%, producing syrups with furan and reducing sugar concentrations of 1 ± 0.1 and 110 ± 10 g/L, respectively.

Molecular and physiological diversity among Verticillium fungicola var. fungicola and var. aleophilum

NARCIS (Netherlands)

Largeteau, M.L.; Baars, J.J.P.; Savoie, J.M.

2006-01-01

The genetic and physiological variability of Verticillium fungicola var. aleophilum responsible for Agaricus bisporus dry bubble disease in North America is well documented but little is known about the var. fungicola affecting European crops. Variability was assessed within this variety and

Chemicals from Agave sisalana Biomass: Isolation and Identification

Science.gov (United States)

Santos, Jener David Gonçalves; Vieira, Ivo Jose Curcino; Braz-Filho, Raimundo; Branco, Alexsandro

2015-01-01

Agave sisalana (sisal) is known worldwide as a source of hard fibers, and Brazil is the largest producer of sisal. Nonetheless, the process of removing the fibers of the sisal leaf generates 95% waste. In this study, we applied chemical sequential steps (hydrothermal extraction, precipitation, liquid-liquid extraction, crystallization, SiO2 and Sephadex LH 20 column chromatography) to obtain pectin, mannitol, succinic acid, kaempferol and a mixture of saponins as raw chemicals from sisal biomass. The structural identification of these compounds was performed though spectrometric methods, such as Infrared (IR), Ultraviolet (UV), Mass spectrometry (MS) and Nuclear magnetic resonance (NMR). All the sisal chemicals found in this work are used by both the chemical and pharmaceutical industries as excipients or active principles in products. PMID:25903149

Taxonomical studies on endemic scorzonera pygmaea var. pygmaea and var. nutans stat. nov. (asteraceae) from turkey

International Nuclear Information System (INIS)

Koyuncu, O.; Kus, G.

2014-01-01

The taxonomic status of Scorzonera pygmaea var. pygmaea and var. nutans belonging to the tribe. cichoreae (Asteraceae). S. pygmaea samples were collected from Arayit mountain. We suggest that these two subspecies should be classified as varietes because of their morphological and anatomical characteristics, ecological and geographical similarities. Moreover being together in the same localities of these under species taxa supports our opinion, i.e. S. pygmaea Sibth. and Sm. var. pygmaea stat. nov. and S. pygmaea Sibth. and Sm. var. nutans (Czeczott) O. Koyuncu and Yaylac, stat. nov. (author)

Analysis list: Su(var)205 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Su(var)205 Adult,Embryo,Larvae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3.../target/Su(var)205.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Su(var)205.5.tsv http://dbarc...hive.biosciencedbc.jp/kyushu-u/dm3/target/Su(var)205.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/c...olo/Su(var)205.Adult.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(var)205.Embryo.tsv,http:...//dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Su(var)205.Larvae.tsv http://dbarchive

4D-Var Developement at GMAO

Science.gov (United States)

Pelc, Joanna S.; Todling, Ricardo; Akkraoui, Amal El

2014-01-01

The Global Modeling and Assimilation Offce (GMAO) is currently using an IAU-based 3D-Var data assimilation system. GMAO has been experimenting with a 3D-Var-hybrid version of its data assimilation system (DAS) for over a year now, which will soon become operational and it will rapidly progress toward a 4D-EnVar. Concurrently, the machinery to exercise traditional 4DVar is in place and it is desirable to have a comparison of the traditional 4D approach with the other available options, and evaluate their performance in the Goddard Earth Observing System (GEOS) DAS. This work will also explore the possibility for constructing a reduced order model (ROM) to make traditional 4D-Var computationally attractive for increasing model resolutions. Part of the research on ROM will be to search for a suitably acceptable space to carry on the corresponding reduction. This poster illustrates how the IAU-based 4D-Var assimilation compares with our currently used IAU-based 3D-Var.

Chemicals from Agave sisalana Biomass: Isolation and Identification

Directory of Open Access Journals (Sweden)

Jener David Gonçalves Santos

2015-04-01

Full Text Available Agave sisalana (sisal is known worldwide as a source of hard fibers, and Brazil is the largest producer of sisal. Nonetheless, the process of removing the fibers of the sisal leaf generates 95% waste. In this study, we applied chemical sequential steps (hydrothermal extraction, precipitation, liquid-liquid extraction, crystallization, SiO2 and Sephadex LH 20 column chromatography to obtain pectin, mannitol, succinic acid, kaempferol and a mixture of saponins as raw chemicals from sisal biomass. The structural identification of these compounds was performed though spectrometric methods, such as Infrared (IR, Ultraviolet (UV, Mass spectrometry (MS and Nuclear magnetic resonance (NMR. All the sisal chemicals found in this work are used by both the chemical and pharmaceutical industries as excipients or active principles in products.

Caracterização química e estrutural de fibra de sisal da variedade Agave sisalana Chemical and structural characterization of sisal fibers from Agave sisalana variety

Directory of Open Access Journals (Sweden)

Adriana R. Martin

2009-01-01

Full Text Available Nos últimos anos, o interesse pelo uso de fibras naturais em materiais compósitos poliméricos tem aumentado significativamente. Neste trabalho foram investigadas as propriedades, químicas, físicas, térmicas e estruturais da fibra de sisal brasileira da variedade Agave sisalana. Nosso objetivo foi avaliar a qualidade e o desempenho desta fibra para aplicações industriais. Foram realizados ensaios de resistência à tração, análise da composição química, difração de raios X, e estudos por microscopia eletrônica de varredura (MEV ao longo do comprimento da fibra. A fibra de sisal brasileira apresentou propriedades mecânicas e térmicas dentro da faixa relatada na literatura, mostrando-se adequada para ser utilizada em materiais compósitos poliméricos.In recent years, the interest in the use of natural fibers in polymeric composite materials has increased significantly. In this work were investigated the structural, thermal, chemical, and physical properties of Brazilian sisal fiber from Agave sisalana variety. Our aim was to evaluate the quality and the performance of this fiber for industrial applications. Mechanical properties, chemical composition, X ray diffraction, and scanning electron microscopy (SEM have been investigated with fibers along their length. The Brazilian sisal fibers studied have exhibited mechanical and thermal properties within the range reported in the literature and were suitable for use in polymeric composites.

New prediction for the direct CP-violating parameter var-epsilon prime/var-epsilon and the ΔI=1/2 rule

International Nuclear Information System (INIS)

Wu, Yue-Liang

2001-01-01

The low-energy dynamics of QCD is investigated with special attention paid to the matching between QCD and chiral perturbation theory (ChPT), and also to some useful algebraic chiral operator relations which survive even when we include chiral loop corrections. It then allows us to evaluate the hadronic matrix elements below the energy scale Λ χ ≅1GeV. Based on the new analyses, we present a consistent prediction for both the direct CP-violating parameter var-epsilonprime/var-epsilon and the ΔI=1/2 rule in kaon decays. In the leading 1/N c approximation, the isospin amplitudes A 0 and A 2 are found to agree well with the data, and the direct CP-violating parameter var-epsilonprime/var-epsilon is predicted to be large, which also confirms our earlier conclusion. Its numerical value is var-epsilonprime/var-epsilon=23.6 -7.8 +12.4 x10 -4 (Imλ t /= 1.2x10 -4 ) which is no longer sensitive to the strange quark mass due to the matching conditions. Taking into account a simultaneous consistent analysis on the isospin amplitudes A 0 and A 2 , the ratio var-epsilonprime/var-epsilon is in favor of the values var-epsilonprime/var-epsilon=(20±9)x10 -4

Survival and infectivity of Sarcoptes scabiei var. canis and var. hominis.

Science.gov (United States)

Arlian, L G; Runyan, R A; Achar, S; Estes, S A

1984-08-01

Sarcoptes scabiei var. canis served as a suitable model for the study of S. scabiei var. hominis survival. S. scabiei var. canis and var. hominis mites were found to survive off the host for 24 to 36 hours at room conditions (21 degrees C and 40% to 80% relative humidity [RH]), and the canine variety survived 19 days at 10 degrees C and 97% RH. Female mites survived decidedly longer than male mites at comparable conditions. Generally, higher RH values and lower temperatures favored survival, whereas higher temperature and lower RH led to early death. Most canine scabies mites that were held off the host for 36 hours at 75% RH and 22 degrees to 24 degrees C remained infective and penetrated when returned to the host. Live mites of the human variety that were recovered from bed linen slept on by infested patients would also penetrate a host after being held off a host for 96 hours in alternating 12-hour periods of room conditions and refrigeration. Penetration required less than 30 minutes for all life stages of both varieties, and it was accomplished by a mite secretion that dissolved the host tissue. Dislodged mites, particularly those in close proximity to the source, can be a likely source of infestation.

Teucrium pruinosum var. aksarayense var. nov. (Lamiaceae from Central Anatolia, Turkey

Directory of Open Access Journals (Sweden)

Muhittin Dinç

2016-06-01

Full Text Available Teucrium pruinosum var. aksarayense M. Dinç & S. Doğu (Lamiaceae, a new variety from Aksaray in Central Anatolia, is described and illustrated. The new variety is similar to the typical one in its calyx teeth uncinate at tip and subequal to the tube with conspicious midvein. It is readily distinguished from var. pruinosum by its general appearance, indumentum, and floral organ pigmentation. The map showing the distributions of the varieties was given.

8. Bebidas alcohólicas mexicanas extraídas de agaves, 19071

OpenAIRE

Diguet, Léon

2013-01-01

Desde una época probablemente bastante remota, los agaves o magueyes han proporcionado a las poblaciones mexicanas valiosos recursos económicos, entre los cuales destacaban las bebidas. Cuando llegaron los conquistadores españoles, la fabricación de estas bebidas tenía un auge considerable; el gobierno español consideraba el cultivo de las viñas en México como contrario a los intereses de la metrópoli, y lo prohibió terminantemente en toda la extensión del territorio conquistado. Con esta pro...

Saponinas esteroidales de la planta Agave brittoniana (Agavaceae con actividad contra el parásito Trichomona vaginalis

Directory of Open Access Journals (Sweden)

José Orestes Guerra

2008-12-01

Full Text Available El género Agave, familia Agavaceae, tiene más de 300 especies, con aproximadamente 16 distribuidas en toda Cuba. Una de ellas, el Agave brittoniana Trel. (ssp. brachypus, es una subespecie endémica y sus hojas son tradicionalmente utilizadas en el tratamiento de enfermedades parasitarias. Se realizaron estudios "in vitro" de la actividad de productos de esta planta frente a Trichomona vaginalis. Las hojas secas y pulverizadas fueron extraídas tres veces con una mezcla de etanol-agua (7: 3 mediante maceración a temperatura ambiente. El disolvente fue evaporado a presión reducida y el extracto fue suspendido en agua destilada, desengrasado con n-hexano, y extraído con n-butanol saturado con agua. Luego de una extracción con acetato de etilo, los productos de la hidrólisis fueron comparados con patrones de sapogeninas mediante la cromatografía de capa fina (CCD. Aislamos las sapogeninas mayoritarias (yuccagenina y diosgenina y confirmamos sus estructuras utilizando técnicas de resonancia magnética nuclear. Por otra parte, el extracto n-butanólico fue sometido a un proceso de separación biodirigido mediante cromatografía de columna, obteniéndose cinco fracciones. Después de múltiples separaciones, la más activa rindió una fracción purificada con dos sapogeninas con el mismo aglicón (diosgenina y un glicósido de yucagenina. Los mejores resultados de esta actividad fueron obtenidos con el glicósido derivado de la yucageninaSteroidal saponins from the plant Agave brittoniana with activity against the parasite Trichomona vaginalis. The genus Agave (Agavaceae, includes more than 300 species; around 16 of them show an homogeneous distribution throughout Cuba. Agave brittoniana (ssp. brachypus, is an endemic subspecies that grows in the central region of the country and its leaves are traditionally used in the treatment of parasitic diseases. The parasite Trichomonas vaginalis causes the disease known as trichomoniasis, that infects

75 FR 57720 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List Agave...

Science.gov (United States)

2010-09-22

... that have not been developed are used for cattle or hay production, minimizing the recovery of native... the exotic Megathyrsus maximus (guinea grass) in the area make the population Agave eggersiana... pest to St Croix. On Mona Island (Puerto Rico), feral pigs are known to uproot juveniles and destroy...

Notes on Agave in Aruba, Curaçao, Bonaire and some parts of the South American continent

NARCIS (Netherlands)

Wagenaar Hummelinck, P.

1936-01-01

This publication deals with some agaves which were collected by me participating as biologist in a geological excursion under Prof. Dr. L. M. R. Rutten and Mrs. Dr. C. J. Rutten-Pekelharing, in the beginning of 1930, to the West Indies. From 14 April to 4 May we camped in the western part of

Effect of ultrasound pre-treatment on the physicochemical composition of Agave durangensis leaves and potential enzyme production.

Science.gov (United States)

Contreras-Hernández, M G; Ochoa-Martínez, L A; Rutiaga-Quiñones, J G; Rocha-Guzmán, N E; Lara-Ceniceros, T E; Contreras-Esquivel, J C; Prado Barragán, L A; Rutiaga-Quiñones, O M

2018-02-01

Approximately 1 million tons of agave plants are processed annually by the Mexican tequila and mezcal industry, generating vast amounts of agroindustrial solid waste. This type of lignocellulosic biomass is considered to be agroindustrial residue, which can be used to produce enzymes, giving it added value. However, the structure of lignocellulosic biomass makes it highly recalcitrant, and results in relatively low yield when used in its native form. The aim of this study was to investigate an effective pre-treatment method for the production of commercially important hydrolytic enzymes. In this work, the physical and chemical modification of Agave durangensis leaves was analysed using ultrasound and high temperature as pre-treatments, and production of enzymes was evaluated. The pre-treatments resulted in modification of the lignocellulosic structure and composition; the ultrasound pre-treatment improved the production of inulinase by 4 U/mg and cellulase by 0.297 U/mg, and thermal pre-treatment improved β-fructofuranosidase by 30 U/mg. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hvem var morderen?

DEFF Research Database (Denmark)

Andersen, Lene Vinther

2014-01-01

Folkemindesamleren og forfatteren Helene Strange (1874-1943) skrev flere gange om et giftmord på en præst på Nordfalster i 1755. Hun satte spørgsmålstegn ved højesteretsdommen og hævdede, at en uskyldig pige blev dømt, mens den virkelige morder slap fri. Det var folkets uskrevne dom, som i over...... hundrede år var blevet fortalt mundtligt videre på egnen, og hun forsøgte – med forskellige midler – at få bragt denne version af historien frem i offentligheden....

The Vibrio cholerae var regulon encodes a metallo-β-lactamase and an antibiotic efflux pump, which are regulated by VarR, a LysR-type transcription factor.

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Hong-Ting Victor Lin

Full Text Available The genome sequence of V. cholerae O1 Biovar Eltor strain N16961 has revealed a putative antibiotic resistance (var regulon that is predicted to encode a transcriptional activator (VarR, which is divergently transcribed relative to the putative resistance genes for both a metallo-β-lactamase (VarG and an antibiotic efflux-pump (VarABCDEF. We sought to test whether these genes could confer antibiotic resistance and are organised as a regulon under the control of VarR. VarG was overexpressed and purified and shown to have β-lactamase activity against penicillins, cephalosporins and carbapenems, having the highest activity against meropenem. The expression of VarABCDEF in the Escherichia coli (ΔacrAB strain KAM3 conferred resistance to a range of drugs, but most significant resistance was to the macrolide spiramycin. A gel-shift analysis was used to determine if VarR bound to the promoter regions of the resistance genes. Consistent with the regulation of these resistance genes, VarR binds to three distinct intergenic regions, varRG, varGA and varBC located upstream and adjacent to varG, varA and varC, respectively. VarR can act as a repressor at the varRG promoter region; whilst this repression was relieved upon addition of β-lactams, these did not dissociate the VarR/varRG-DNA complex, indicating that the de-repression of varR by β-lactams is indirect. Considering that the genomic arrangement of VarR-VarG is strikingly similar to that of AmpR-AmpC system, it is possible that V. cholerae has evolved a system for resistance to the newer β-lactams that would prove more beneficial to the bacterium in light of current selective pressures.

El mezcal en Sonora, México, más que una bebida espirituosa. Etnobotánica de Agave angustifolia Haw

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Noemí Bañuelos Flores

2012-01-01

Full Text Available ¿Cómo sería la vida de los sonorenses sin el mezcal? La interrogante guía el propósito general del trabajo, orientado a identificar la importancia que tradicionalmente ha revestido el Agave angustifolia en la vida cotidiana de los sonorenses. En su mayor parte, los estudios existentes en Sonora en torno a esta especie se enfocan, básicamente, en su uso para la elaboración industrial del licor, popularmente conocido como bacanora. La investigación pretende contribuir, en alguna medida, al mayor conocimiento del valor biológico y cultural de la planta. Con ese objetivo se recurre a la etnobotánica para obtener una mirada más completa de las formas en las que los hombres y mujeres se han relacionado con el agave. La región de estudio comprende dos zonas mezcaleras: la sierra orien-te, donde la mayor parte de la población es mestiza, y la zona sur, donde los grupos indígenas Mayo y Guarijío cohabitan con mestizos. Se realizaron entrevistas a profundidad a diversos pobladores, así como a investigadores y otros estudiosos de la planta. Se consultaron las fuentes históricas disponibles. Los resultados muestran la existencia de diferencias regionales en los usos del agave y técnicas de preparación, determinadas por un número de factores estrechamente vinculados con el grupo étnico de los pobladores y su historia.

VaR Methodology Application for Banking Currency Portfolios

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Daniel Armeanu

2007-02-01

Full Text Available VaR has become the standard measure that financial analysts use to quantify market risk. VaR measures can have many applications, such as in risk management, to evaluate the performance of risk takers and for regulatory requirements, and hence it is very important to develop methodologies that provide accurate estimates. In particular, the Basel Committee on Banking Supervision at the Bank for International Settlements imposes to financial institutions such as banks and investment firms to meet capital requirements based on VaR estimates. In this paper we determine VaR for a banking currency portfolio and respect rules of National Bank of Romania regarding VaR report.

Size-exclusion chromatography (HPLC-SEC) technique optimization by simplex method to estimate molecular weight distribution of agave fructans.

Science.gov (United States)

Moreno-Vilet, Lorena; Bostyn, Stéphane; Flores-Montaño, Jose-Luis; Camacho-Ruiz, Rosa-María

2017-12-15

Agave fructans are increasingly important in food industry and nutrition sciences as a potential ingredient of functional food, thus practical analysis tools to characterize them are needed. In view of the importance of the molecular weight on the functional properties of agave fructans, this study has the purpose to optimize a method to determine their molecular weight distribution by HPLC-SEC for industrial application. The optimization was carried out using a simplex method. The optimum conditions obtained were at column temperature of 61.7°C using tri-distilled water without salt, adjusted pH of 5.4 and a flow rate of 0.36mL/min. The exclusion range is from 1 to 49 of polymerization degree (180-7966Da). This proposed method represents an accurate and fast alternative to standard methods involving multiple-detection or hydrolysis of fructans. The industrial applications of this technique might be for quality control, study of fractionation processes and determination of purity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carbon isotopes from fossil packrat pellets and elevational movements of Utah agave plants reveal the Younger Dryas cold period in Grand Canyon, Arizona

Science.gov (United States)

Cole, K.L.; Arundel, S.T.

2005-01-01

Carbon isotopes in rodent fecal pellets were measured on packrat (Neotoma spp.) middens from the Grand Canyon, Arizona. The pellet samples reflect the abundance of cold-intolerant C4 and Crassulacean acid metabolism (CAM) plant species relative to the predominant C3 vegetation in the packrat diet. The temporal sequence of isotopic results suggests a temperature decline followed by a sharp increase corresponding to the B??lling/Aller??d-Younger Dryas - early Holocene sequence. This pattern was then tested using the past distribution of Utah agave (Agave utahensis). Spatial analyses of the range of this temperature-sensitive CAM species demonstrate that its upper elevational limit is controlled by winter minimum temperature. Applying this paleotemperature proxy to the past elevational limits of Utah agave suggests that minimum winter temperatures were ???8??C below modern values during the Last Glacial Maximum, 4.5-6.5 ??C below modern during the B??lling/Aller??d, and 7.5-8.7 ??C below modern during the early Younger Dryas. As the Younger Dryas terminated, temperatures warmed ???4 ??C between ca. 11.8 ka and 11.5 ka. These extreme fluctuations in winter minimum temperature have not been generally accepted for terrestrial paleoecological records from the arid southwestern United States, likely because of large statistical uncertainties of older radiocarbon results and reliance on proxies for summer temperatures, which were less affected. ?? 2005 Geological Society of America.

[Physiological characteristics of Pinus densiflora var. zhangwuensis and Pinus sylvestris var. mongolica seedlings on sandy lands under salt-alkali stresses].

Science.gov (United States)

Meng, Peng; Li, Yu-Ling; Zhang, Bai-xi

2013-02-01

For the popularization of Pinus densiflora var. zhangwuensis, a new afforestation tree species on the desertified and salinized-alkalized lands in Northern China, and to evaluate the salinity-alkalinity tolerance of the tree species and to better understand the tolerance mechanisms, a pot experiment with 4-year old P. densiflora var. zhangwuensis and P. sylvestris var. mongolica was conducted to study their seedlings growth and physiological and biochemical indices under the effects of three types salt (NaCl, Na2CO3, and NaHCO3 ) stresses and of alkali (NaOH) stress. Under the salt-alkali stresses, the injury level of P. densiflora var. zhangwuensis was lower, and the root tolerance index was higher. The leaf catalase (CAT) activity increased significantly by 22. 6 times at the most, as compared with the control; the leaf malondialdehyde (MDA) content had no significant increase; the leaf chlorophyll (Chl) content had a smaller decrement; and the leaf water content (LWC) increased slightly. P. sylvestris var. mongolica responded differently to the salt-alkali stresses. Its leaf CAT activity had less change, MDA content increased significantly, Chl content had significant decrease, and LWC decreased slightly. It was suggested that P. densi-flora var. zhangwuensis had a greater salinity-alkalinity tolerance than P. sylvestris var. mongolica. The higher iron concentration in P. densiflora var. zhangwuensis needles enhanced the CAT activity and Chl content, whereas the higher concentrations of zinc and copper were associated with the stronger salinity-alkalinity tolerance.

dbVar

Data.gov (United States)

U.S. Department of Health & Human Services — dbVar is a database of genomic structural variation. It accepts data from all species and includes clinical data. It can accept diverse types of events, including...

Effect of aguamiel (agave sap) on hematic biometry in rabbits and its antioxidant activity determination

OpenAIRE

Héctor Silos-Espino; José Luis Moreno Hernández-Duque; Fidel Guevara-Lara; Juan Florencio Gómez-Leyva; Luis Lorenzo Valera-Montero; Alejandro Nava-Cedillo; Catarino Perales-Segovia; Clara Lourdes Tovar-Robles

2011-01-01

In this work, we analysed the effect of aguamiel (sap from Agave salmiana) on haematic biometry in rabbits as well as its antioxidant activity with the objective of determining its nutritional value. Nine male Landrace 55-day-old rabbits were sorted into three groups of three rabbits each, which had access to fresh aguamiel, boiled aguamiel and water instead of aguamiel. Commercial rabbit food was supplied ad libitum to each experimental unit. Fresh aguamiel promoted weight increases of about...

Micropropagation of Agave salmiana: Means to Production of Antioxidant and Bioactive Principles.

Science.gov (United States)

Puente-Garza, César A; Gutiérrez-Mora, Antonia; García-Lara, Silverio

2015-01-01

Maguey, Agave salmiana, is an important plant for the "pulque" beverage and functional food industries; however, it has several constraints for elite and homogeneous plant production. In this study, a micropropagation process was established to generate in vitro plants. The effect of the method on metabolite content and antioxidant (AOX) activity in regenerated plants was evaluated. Young germinated plantlets were micropropagated from axillary shoots using Murashige and Skoog medium supplemented with L2 vitamins, 0.04 mg/L 2,4-dichlorophenoxyacetic acid and 10 mg/L 6-benzylaminopurine. Total soluble sugars from the aqueous fraction and total phenolic acids, total saponins, and AOX activity of the methanol fraction were determined in wild-type (WT) plants, in in vitro (IN) plants, and ex vitro acclimated plants (EN). The results showed that IN plants have a 50% lower soluble sugar content compared to WT, and EN. The total phenolic acids content was at least 30% higher in micropropagated (IN) and regenerated (EN) plants compared to WT. The total saponin content in IN, and EN plants was 36 and 25 times higher compared to WT. The AOX capacity of IN plants was on average three times higher compared to other treatments. However, no correlation was found between the AOX activity and total phenolic acids or total saponins. A negative and significant correlation (r = -0.927; p = 0.003) was found between the AOX activity and the total soluble sugars content. Micropropagated plants of A. salmiana have a different phytochemical content and bioactivity after the in vitro process compared to WT plants. The micropropagation process could be used as a platform for phytochemical enhancement of Agave plants.

Micropropagation of Agave salmiana: Means to production of antioxidant and bioactive principles.

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César Armando Puente-Garza

2015-11-01

Full Text Available Maguey, Agave salmiana, is an important plant for the pulque beverage and functional food industries; however, it has several constraints for elite and homogeneous plant production. In this study, a micropropagation process was established to generate in vitro plants. The effect of the method on metabolite content and antioxidant (AOX activity in regenerated plants was evaluated. Young germinated plantlets were micropropagated from axillary shoots using Murashige and Skoog medium supplemented with L2 vitamins, 0.04 mg/L 2,4-dichlorophenoxyacetic acid and 10 mg/L 6-benzylaminopurine. Total soluble sugars from the aqueous fraction and total phenolic acids, total saponins, and AOX activity of the methanol fraction were determined in wild type (WT plants, in in vitro (IN plants, and ex vitro acclimated plants (EN. The results showed that IN plants have a 50% lower soluble sugar content compared to WT and EN. The total phenolic acids content was at least 30% higher in micropropagated (IN and regenerated (EN plants compared to WT. The total saponin content in IN and EN plants was 36 and 25 times higher compared to WT. The AOX capacity of IN plants was on average three times higher compared to other treatments. However, no correlation was found between the AOX activity and total phenolic acids or total saponins. A negative and significant correlation (r = -0.927; p = 0.003 was found between the AOX activity and the total soluble sugars content. Micropropagated plants of A. salmiana have a different phytochemical content and bioactivity after the in vitro process compared to wild plants. The micropropagation process could be used as a platform for phytochemical enhancement of Agave plants.

Paulus var kristendommens Lenin

DEFF Research Database (Denmark)

Thyssen, Ole

2017-01-01

En af Luthers inspirationskilder var Paulus, hvis løsning på lokale problemer fik globale konsekvenser. Han trak en skarp grænse mellem det snavsede kød og den rene sjæl og mellem vantro og tro.......En af Luthers inspirationskilder var Paulus, hvis løsning på lokale problemer fik globale konsekvenser. Han trak en skarp grænse mellem det snavsede kød og den rene sjæl og mellem vantro og tro....

B. oleracea var. capitata monosomic and disomic alien

Indian Academy of Sciences (India)

Five monosomic alien addition lines (MAALs) of Brassica rapa ssp. pekinensis – B. oleracea var. capitata were obtained by hybridization and backcrossing between B. rapa ssp. pekinensis (female parent) and B. oleracea var. capitata. The alien linkage groups were identified using 42 B. oleracea var. capitata linkage ...

Da Danmark var en slavenation

DEFF Research Database (Denmark)

Peters, Rikke Louise Alberg; Brunbech, Peter Johan Yding; Poulsen, Jens Aage

I mere end 250 år var Danmark en stor kolonimagt. Skt. Jan, Skt. Thomas og Skt. Croix, eller U.S. Virgin Islands, som de kaldes i dag, var danske kolonier, hvor der bl.a. blev dyrket sukkerrør og bomuld. Det hårde arbejde blev udført af slaver, som man fra slutningen af 1600-tallet begyndte at tr...

Screening of native yeast from Agave duranguensis fermentation for isoamyl acetate production

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Gerardo Hernández-Carbajal

2013-06-01

Full Text Available In this work, fifty yeast strains, isolated from the spontaneous alcoholic fermentation of Agave duranguensis to produce mezcal, were tested using the double coupling system. These yeasts were from the genera Pichia, Torulaspora, Saccharomyces, Kluyveromyces, Deckera, Hanseniaspora, and Candida. P. fermentans ITD00165 was the best isoamyl acetate producer, yielding 0.38 g/L of ester after incubation for 24 h, while K. marxianus ITD00211 produced 0.32 g/L of ester. Thus P. fermentans TD00165 could be considered as an excellent choice for use in optimization studies of the culture medium and bioreactor operating conditions to develop a process for biotechnological production of isoamyl acetate.

ESTIMASI NILAI VaR PORTOFOLIO MENGGUNAKAN FUNGSI ARCHIMEDEAN COPULA

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AULIA ATIKA PRAWIBTA SUHARTO

2017-01-01

Full Text Available Value at Risk explains the magnitude of the worst losses occurred in financial products investments with a certain level of confidence and time interval. The purpose of this study is to estimate the VaR of portfolio using Archimedean Copula family. The methods for calculating the VaR are as follows: (1 calculating the stock return; (2 calculating descriptive statistics of return; (3 checking for the nature of autocorrelation and heteroscedasticity effects on stock return data; (4 checking for the presence of extreme value by using Pareto tail; (5 estimating the parameters of Achimedean Copula family; (6 conducting simulations of Archimedean Copula; (7 estimating the value of the stock portfolio VaR. This study uses the closing price of TLKM and GGRM. At 90% the VaR obtained using Clayton, Gumbel, Frank copulas are 0.9562%, 1.0189%, 0.9827% respectively. At 95% the VaR obtained using Clayton, Gumbel, Frank copulas are 1.2930%, 1.2522%, 1.3152% respectively. At 99% the VaR obtained using Clayton, Gumbel, Frank copulas are 2.0327%, 1.9164%, is 1.8678% respectively. In conclusion estimation of VaR using Clayton copula yields the highest VaR.

KNOX1 is expressed and epigenetically regulated during in vitro conditions in Agave spp

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De-la-Peña Clelia

2012-11-01

Full Text Available Abstract Background The micropropagation is a powerful tool to scale up plants of economical and agronomical importance, enhancing crop productivity. However, a small but growing body of evidence suggests that epigenetic mechanisms, such as DNA methylation and histone modifications, can be affected under the in vitro conditions characteristic of micropropagation. Here, we tested whether the adaptation to different in vitro systems (Magenta boxes and Bioreactors modified epigenetically different clones of Agave fourcroydes and A. angustifolia. Furthermore, we assessed whether these epigenetic changes affect the regulatory expression of KNOTTED1-like HOMEOBOX (KNOX transcription factors. Results To gain a better understanding of epigenetic changes during in vitro and ex vitro conditions in Agave fourcroydes and A. angustifolia, we analyzed global DNA methylation, as well as different histone modification marks, in two different systems: semisolid in Magenta boxes (M and temporary immersion in modular Bioreactors (B. No significant difference was found in DNA methylation in A. fourcroydes grown in either M or B. However, when A. fourcroydes was compared with A. angustifolia, there was a two-fold difference in DNA methylation between the species, independent of the in vitro system used. Furthermore, we detected an absence or a low amount of the repressive mark H3K9me2 in ex vitro conditions in plants that were cultured earlier either in M or B. Moreover, the expression of AtqKNOX1 and AtqKNOX2, on A. fourcroydes and A. angustifolia clones, is affected during in vitro conditions. Therefore, we used Chromatin ImmunoPrecipitation (ChIP to know whether these genes were epigenetically regulated. In the case of AtqKNOX1, the H3K4me3 and H3K9me2 were affected during in vitro conditions in comparison with AtqKNOX2. Conclusions Agave clones plants with higher DNA methylation during in vitro conditions were better adapted to ex vitro conditions. In addition

Histology study of the somatic embryogenesis in Agave fourcroydes Lem.

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Silvia Alemán García

2002-01-01

Full Text Available A histological study of the structures embryogenic formed from meristem of Agave fourcroydes, with the objective of observing the behavior of the somatic embryogenesis from the induction until the formation of the embryo was carried out. The meristem cultivated in vitro was subculture in modified MS medium the induction. The samples to be included intheresinJB–4weretakenperiodically.Thehistologicalscutsof5-10µmwerecarriedoutwithrotatorymicrotome and strained in 2% toluidine blue. The sections were observed and photographed in light microscopy Axioplan Zeiis with increases of 20X. The results show to the 60 days of culture the presence of cells meristematic pre-embrygenic. Embryos in different phases of formation globular and scutellum were observed in all the mass of the callus in the following subculture. Key words: Agavaceae, in vitro culture, embryo, histology

Over de verspreiding binnen Nederland van Bidens connata var. fallax (Warnst.) Sherf en var. anomala Farw

NARCIS (Netherlands)

Ballintijn, Koos (J.) F.

1997-01-01

On the basis of recent observations and study of herbarium material it might tentatively be concluded that var. anomala (with erecto-patent barb hairs on achenes as well as on the bristles) is becoming more common since 1954 and might be locally replacing the hitherto more common var. fallax (with

Ethanol yield and volatile compound content in fermentation of agave must by Kluyveromyces marxianus UMPe-1 comparing with Saccharomyces cerevisiae baker's yeast used in tequila production.

Science.gov (United States)

López-Alvarez, Arnoldo; Díaz-Pérez, Alma Laura; Sosa-Aguirre, Carlos; Macías-Rodríguez, Lourdes; Campos-García, Jesús

2012-05-01

In tequila production, fermentation is an important step. Fermentation determines the ethanol productivity and organoleptic properties of the beverage. In this study, a yeast isolated from native residual agave must was identified as Kluyveromyces marxianus UMPe-1 by 26S rRNA sequencing. This yeast was compared with the baker's yeast Saccharomyces cerevisiae Pan1. Our findings demonstrate that the UMPe-1 yeast was able to support the sugar content of agave must and glucose up to 22% (w/v) and tolerated 10% (v/v) ethanol concentration in the medium with 50% cells survival. Pilot and industrial fermentation of agave must tests showed that the K. marxianus UMPe-1 yeast produced ethanol with yields of 94% and 96% with respect to fermentable sugar content (glucose and fructose, constituting 98%). The S. cerevisiae Pan1 baker's yeast, however, which is commonly used in some tequila factories, showed 76% and 70% yield. At the industrial level, UMPe-1 yeast shows a maximum velocity of fermentable sugar consumption of 2.27g·L(-1)·h(-1) and ethanol production of 1.38g·L(-1)·h(-1), providing 58.78g ethanol·L(-1) at 72h fermentation, which corresponds to 96% yield. In addition, the major and minor volatile compounds in the tequila beverage obtained from UMPe-1 yeast were increased. Importantly, 29 volatile compounds were identified, while the beverage obtained from Pan1-yeast contained fewer compounds and in lower concentrations. The results suggest that the K. marxianus UMPe-1 is a suitable yeast for agave must fermentation, showing high ethanol productivity and increased volatile compound content comparing with a S. cerevisiae baker's yeast used in tequila production. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Morphological and genetic divergence between Agave inaequidens, A. cupreata and the domesticated A. hookeri. Analysis of their evolutionary relationships.

Directory of Open Access Journals (Sweden)

Carmen J Figueredo-Urbina

Full Text Available Agave inaequidens and A. cupreata are wild species with some populations under incipient management, while A. hookeri is exclusively cultivated, used for producing the fermented beverage pulque. These species are closely related and sympatric members of the Crenatae group, but taxonomists have previously hypothesized that A. inaequidens is the most probable ancestor of A. hookeri. Our study aims at evaluating patterns of morphological and genetic divergence among populations of the three species, in order to analyze their ecological and possible evolutionary relationships. We studied 24 agave populations, 16 of them of Agave inaequidens, four of A. cupreata and four of A. hookeri. Population morphometric and genetics studies were performed using 39 morphological characters and 10 nuclear microsatellites, respectively. We estimated levels of morphological and genetic diversity and dissimilarity, as well as genetic structure and gene flow among populations and species. The three species were clearly differentiated by general plant size, lateral teeth, terminal spines, flowers and fruit size. The largest plants were those of A. hookeri followed by A. inaequidens and the smallest were A. cupreata. Multivariate analyses indicated greater morphological similarity between A. hookeri and cultivated A. inaequidens, while A. cupreata consistently appeared as a separate group. We identified similar levels of morphological diversity index (MDI in the three species, but higher genetic diversity in A. inaequidens (MDI = 0.401-0.435; HE = 0.704-0.733, than in A. cupreata (MDI = 0.455-0.523; HE = 0.480-0.510 and the predominantly vegetative propagated crop A. hookeri (MDI = 0.335-0.688; HE = 0.450-0.567, a pattern consistent with our expectations. The morphological and genetic similarities between cultivated A. inaequidens and A. hookeri support the hypothetical evolutionary relationships among these species, but studies with cpDNA and SNPs, and including other

Morphological and genetic divergence between Agave inaequidens, A. cupreata and the domesticated A. hookeri. Analysis of their evolutionary relationships.

Science.gov (United States)

Figueredo-Urbina, Carmen J; Casas, Alejandro; Torres-García, Ignacio

2017-01-01

Agave inaequidens and A. cupreata are wild species with some populations under incipient management, while A. hookeri is exclusively cultivated, used for producing the fermented beverage pulque. These species are closely related and sympatric members of the Crenatae group, but taxonomists have previously hypothesized that A. inaequidens is the most probable ancestor of A. hookeri. Our study aims at evaluating patterns of morphological and genetic divergence among populations of the three species, in order to analyze their ecological and possible evolutionary relationships. We studied 24 agave populations, 16 of them of Agave inaequidens, four of A. cupreata and four of A. hookeri. Population morphometric and genetics studies were performed using 39 morphological characters and 10 nuclear microsatellites, respectively. We estimated levels of morphological and genetic diversity and dissimilarity, as well as genetic structure and gene flow among populations and species. The three species were clearly differentiated by general plant size, lateral teeth, terminal spines, flowers and fruit size. The largest plants were those of A. hookeri followed by A. inaequidens and the smallest were A. cupreata. Multivariate analyses indicated greater morphological similarity between A. hookeri and cultivated A. inaequidens, while A. cupreata consistently appeared as a separate group. We identified similar levels of morphological diversity index (MDI) in the three species, but higher genetic diversity in A. inaequidens (MDI = 0.401-0.435; HE = 0.704-0.733), than in A. cupreata (MDI = 0.455-0.523; HE = 0.480-0.510) and the predominantly vegetative propagated crop A. hookeri (MDI = 0.335-0.688; HE = 0.450-0.567), a pattern consistent with our expectations. The morphological and genetic similarities between cultivated A. inaequidens and A. hookeri support the hypothetical evolutionary relationships among these species, but studies with cpDNA and SNPs, and including other member of the

Strategy for the extraction of yeast DNA from artisan agave must for quantitative PCR analysis.

Science.gov (United States)

Kirchmayr, Manuel Reinhart; Segura-Garcia, Luis Eduardo; Flores-Berrios, Ericka Patricia; Gschaedler, Anne

2011-11-01

An efficient method for the direct extraction of yeast genomic DNA from agave must was developed. The optimized protocol, which was based on silica-adsorption of DNA on microcolumns, included an enzymatic cell wall degradation step followed by prolonged lysis with hot detergent. The resulting extracts were suitable templates for subsequent qPCR assays that quantified mixed yeast populations in artisan Mexican mezcal fermentations. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Sistema radicular do fórmio, sisal e bambu imperial Root systems of new zealand flax, sisal, and imperial bamboo

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Júlio César Medina

1963-01-01

Full Text Available Os autores apresentam e discutem os resultados de estudos preliminares sôbre o sistema radicular do fórmio (Phormium tenax Forster, sisal (Agave sisalana Perrine e bambu .imperial (Bambusa vulgaris Schrad. var. vittata A. ,& C, Riv.. Concluem, que o sistema radicular do fórmio é relativamente raso, o do sisal bastante superficial é o do bambu imperial se limitada às primeiras carnadas do solo.Results of preliminary studies on root-systems of New Zealand flax (Phormium tenax Forster, sisal (Agave sisalana Perrine, and imperial bamboo (Bambusa vulgaris Schrad. var. vittata A. & C. Riv. plants by the method of soil block, are apresented and discussed by the authors. According to local soil conditions, it is concluded that the root-system of New Zealand flax is relatively superficial, with the main concentration of roots in the 12 in. soil top layer. In sisal, the root-systems of the three plants investigated were found to occur in the soil surface layer, with more of 90% of the roots in the top 6 in. Finally, in the imperial bamboo clump atudied, the main concentration of roots was found in the layer 6-12 in. deep.

Hybrid VAR compensator with improved efficiency

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V. V. Burlaka

2015-03-01

Full Text Available In modern electrical networks thyristor-switched capacitors (TSC are most used devices for VAR compensation. These devices don’t contain rotating parts and mechanical contacts, provide a stepwise control of reactive power and no generation of harmonics to the network. However, with the help of TSC it’s not possible to ensure smooth control of reactive power and capacitor banks (CB are exposed to the negative impact of higher harmonic components of the network voltage. Hybrid VAR compensator don’t have such drawbacks. It consists of active filter (AF and capacitor bank with discrete regulation. The main drawback of such systems is the necessity of accessing all six terminals of CB, while most of them are manufactured with three terminals, internally delta-connected. In the article, the topology and control system of hybrid VAR compensator free from beforementioned drawback, is proposed. The control system provides operating modes of overcompensation or undercompensation reactive power. VAR distribution regulator performs redistribution of reactive power between active filter and capacitor banks with the condition to minimize active filter’s power. Scheme of the hybrid VAR compensator, which includes a three-phase three-terminal delta-connected capacitor banks, is shown. Proposed approach allows to provide smooth control of reactive power, isolate the capacitor bank from harmonic currents and use a more effective low-voltage power components

Var der noget kapløb?

DEFF Research Database (Denmark)

Gimpel, Denise; Nielsen, Bent

2006-01-01

Hvorfor faldt Kina bagud i kapløbet med Vesten?« spørger David Favrholdt i sidste nummer af Weekendavisen. Var der overhovedet noget kapløb? Forudsætter et kapløb ikke, at man har et fælles mål? Spørgsmålet implicerer, at Vesten har vundet og indplacerer samtidig klodens øvrige kulturer i forhold....... Som en af 1900-tallets største sinologer A. C. Graham skriver i sin bog Disputers of the Tao (La Salle, Ill., 1989) var den videnskabelige revolution »en unik og kompleks begivenhed, som var afhængig af en mangfoldighed af sociale og andre betingelser, herunder et sammenfald af opdagelser (græske......, indiske, kinesiske, arabiske, næsten ingen romerske) koncentreret om kombinationen af indiske tal og aritmetik og græsk logik og geometri« (s. 317). En unik begivenhed, som er forekommet én gang i verdenshistorien. Det giver derfor ingen mening at spørge, hvorfor det ikke skete andre steder. Hvis det var...

Anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidea and var. angustifolia on 3T3-L1 adipocytes.

Science.gov (United States)

Woon, Shiau Mei; Seng, Yew Wei; Ling, Anna Pick Kiong; Chye, Soi Moi; Koh, Rhun Yian

2014-03-01

This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes. Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content (TFC) and total phenolic content (TPC), respectively. The study was initiated by determining the maximum non-toxic dose (MNTD) of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD (½MNTD), after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density (OD) at 520 nm, respectively. The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents (QE)/100 g dry weight (DW), while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents (GAE)/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were (300.0 ± 28.3) and (225.0 ± 21.2) µg/ml, respectively, for var. deltoidea, while much lower MNTDs [(60.0 ± 2.0) µg/ml for methanol extracts and (8.0 ± 1.0) µg/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or ½MNTD significantly inhibited the maturation of preadipocytes. The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects.

Comparison between 3D-Var and 4D-Var data assimilation methods for the simulation of a heavy rainfall case in central Italy

Science.gov (United States)

Mazzarella, Vincenzo; Maiello, Ida; Capozzi, Vincenzo; Budillon, Giorgio; Ferretti, Rossella

2017-08-01

This work aims to provide a comparison between three dimensional and four dimensional variational data assimilation methods (3D-Var and 4D-Var) for a heavy rainfall case in central Italy. To evaluate the impact of the assimilation of reflectivity and radial velocity acquired from Monte Midia Doppler radar into the Weather Research Forecasting (WRF) model, the quantitative precipitation forecast (QPF) is used.The two methods are compared for a heavy rainfall event that occurred in central Italy on 14 September 2012 during the first Special Observation Period (SOP1) of the HyMeX (HYdrological cycle in Mediterranean EXperiment) campaign. This event, characterized by a deep low pressure system over the Tyrrhenian Sea, produced flash floods over the Marche and Abruzzo regions, where rainfall maxima reached more than 150 mm 24 h-1.To identify the best QPF, nine experiments are performed using 3D-Var and 4D-Var data assimilation techniques. All simulations are compared in terms of rainfall forecast and precipitation measured by the gauges through three statistical indicators: probability of detection (POD), critical success index (CSI) and false alarm ratio (FAR). The assimilation of conventional observations with 4D-Var method improves the QPF compared to 3D-Var. In addition, the use of radar measurements in 4D-Var simulations enhances the performances of statistical scores for higher rainfall thresholds.

VAR Methodology Used for Exchange Risk Measurement and Prevention

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Florentina Balu

2006-05-01

Full Text Available In this article we discuss one of the modern risk measuring techniques Value-at-Risk (VaR. Currently central banks in major money centers, under the auspices of the BIS Basle Committee, adopt the VaR system to evaluate the market risk of their supervised banks. Banks regulators ask all commercial banks to report VaRs with their internal models. Value at risk (VaR is a powerful tool for assessing market risk, but it also imposes a challenge. Its power is its generality. Unlike market risk metrics such as the Greeks, duration and convexity, or beta, which are applicable to only certain asset categories or certain sources of market risk, VaR is general. It is based on the probability distribution for a portfolio’s market value. Value at Risk (VAR calculates the maximum loss expected (or worst case scenario on an investment, over a given time period and given a specified degree of confidence. There are three methods by which VaR can be calculated: the historical simulation, the variance-covariance method and the Monte Carlo simulation. The variance-covariance method is easiest because you need to estimate only two factors: average return and standard deviation. However, it assumes returns are well-behaved according to the symmetrical normal curve and that historical patterns will repeat into the future. The historical simulation improves on the accuracy of the VAR calculation, but requires more computational data; it also assumes that “past is prologue”. The Monte Carlo simulation is complex, but has the advantage of allowing users to tailor ideas about future patterns that depart from historical patterns.

VAR Methodology Used for Exchange Risk Measurement and Prevention

Directory of Open Access Journals (Sweden)

Ion Stancu

2006-03-01

Full Text Available In this article we discuss one of the modern risk measuring techniques Value-at-Risk (VaR. Currently central banks in major money centers, under the auspices of the BIS Basle Committee, adopt the VaR system to evaluate the market risk of their supervised banks. Banks regulators ask all commercial banks to report VaRs with their internal models. Value at risk (VaR is a powerful tool for assessing market risk, but it also imposes a challenge. Its power is its generality. Unlike market risk metrics such as the Greeks, duration and convexity, or beta, which are applicable to only certain asset categories or certain sources of market risk, VaR is general. It is based on the probability distribution for a portfolio’s market value. Value at Risk (VAR calculates the maximum loss expected (or worst case scenario on an investment, over a given time period and given a specified degree of confidence. There are three methods by which VaR can be calculated: the historical simulation, the variance-covariance method and the Monte Carlo simulation. The variance-covariance method is easiest because you need to estimate only two factors: average return and standard deviation. However, it assumes returns are well-behaved according to the symmetrical normal curve and that historical patterns will repeat into the future. The historical simulation improves on the accuracy of the VAR calculation, but requires more computational data; it also assumes that “past is prologue”. The Monte Carlo simulation is complex, but has the advantage of allowing users to tailor ideas about future patterns that depart from historical patterns.

Morphological and genetic differences between Coptis japonica var. anemonifolia H. Ohba and Coptis japonica var. major Satake in Hokuriku area.

Science.gov (United States)

Kitamura, Masashi; Ando, Hirokazu; Sasaki, Yohei

2018-03-01

Coptis japonica is widely distributed in Japan, and its dried rhizome is a source of the domestic herbal medicine Coptidis Rhizoma ( Oren). There are three varieties of C. japonica, two of which, namely, C. japonica var. anemonifolia and C. japonica var. major, are important as sources of traditional medicines. Coptis japonica var. anemonifolia and C. japonica var. major are distinguishable on the basis of their ternate or biternate compound leaves, respectively. In the Hokuriku area, where both C. japonica var. anemonifolia and C. japonica var. major grow naturally, some individual plants cannot be identified unambiguously on the basis of leaf morphology because changes in leaf morphology may occur due to intra-variety variation or crossbreeding between the two varieties. In addition, genetic differences between the two varieties have remained unclear. In this study, we employed new genetic and morphological classification approaches to discriminate between the two varieties. Based on the single nucleotide polymorphisms of the tetrahydroberberine oxidase gene, we found four conserved SNPs between the two varieties and were able to classify C. japonica into two varieties and crossbreeds. Furthermore, we introduced a new leaf type index based on the overall degree of leaflet dissection calculated by surface area of a leaflet and length of leaflet margin and petiolule. Using our new index we were able to discriminate between the two varieties and their crossbreeds more accurately than is possible with the conventional discrimination method. Our genetic and morphological classification methods may be used as novel benchmarks to discriminate between the two varieties and their crossbreeds.

Some tests for parameter constancy in cointegrated VAR-models

DEFF Research Database (Denmark)

Hansen, Henrik; Johansen, Søren

1999-01-01

Some methods for the evaluation of parameter constancy in vector autoregressive (VAR) models are discussed. Two different ways of re-estimating the VAR model are proposed; one in which all parameters are estimated recursively based upon the likelihood function for the first observations, and anot...... be applied to test the constancy of the long-run parameters in the cointegrated VAR-model. All results are illustrated using a model for the term structure of interest rates on US Treasury securities. ......Some methods for the evaluation of parameter constancy in vector autoregressive (VAR) models are discussed. Two different ways of re-estimating the VAR model are proposed; one in which all parameters are estimated recursively based upon the likelihood function for the first observations......, and another in which the cointegrating relations are estimated recursively from a likelihood function, where the short-run parameters have been concentrated out. We suggest graphical procedures based on recursively estimated eigenvalues to evaluate the constancy of the long-run parameters in the model...

Foliar flavonoids from Tanacetum vulgare var. boreale and their geographical variation.

Science.gov (United States)

Uehara, Ayumi; Akiyama, Shinobu; Iwashina, Tsukasa

2015-03-01

Foliar flavonoids of Tanacetum vulgare var. boreale were isolated. Eight flavonoid glycosides, 7-O-glucosides of apigenin, luteolin, scutellarein and 6- hydroxyluteolin, and 7-O-glucuronides of apigenin, luteolin, chrysoeriol and eriodictyol were identified. Moreover, eight flavonoid aglycones, apigenin, luteolin, hispidulin, nepetin, eupatilin, jaceosidin, pectolinarigenin and axillarin were also isolated and identified. The flavonoid composition of two varieties of T. vulgare, i.e. var. boreale and var. vulgare, were compared. All samples of var. boreale and one sample of var. vulgare had the same flavonoid pattern, and could be distinguished from almost all the samples of var. vulgare. Thus, the occurrence of chemotypes, which are characterized by either the presence or absence of scutellarein 7-O-glucoside, eriodictyol 7-O-glucuronide and pectolinarigenin was shown in T. vulgare sensu lato.

Activation and clustering of a Plasmodium falciparum var gene are affected by subtelomeric sequences.

Science.gov (United States)

Duffy, Michael F; Tang, Jingyi; Sumardy, Fransisca; Nguyen, Hanh H T; Selvarajah, Shamista A; Josling, Gabrielle A; Day, Karen P; Petter, Michaela; Brown, Graham V

2017-01-01

The Plasmodium falciparum var multigene family encodes the cytoadhesive, variant antigen PfEMP1. P. falciparum antigenic variation and cytoadhesion specificity are controlled by epigenetic switching between the single, or few, simultaneously expressed var genes. Most var genes are maintained in perinuclear clusters of heterochromatic telomeres. The active var gene(s) occupy a single, perinuclear var expression site. It is unresolved whether the var expression site forms in situ at a telomeric cluster or whether it is an extant compartment to which single chromosomes travel, thus controlling var switching. Here we show that transcription of a var gene did not require decreased colocalisation with clusters of telomeres, supporting var expression site formation in situ. However following recombination within adjacent subtelomeric sequences, the same var gene was persistently activated and did colocalise less with telomeric clusters. Thus, participation in stable, heterochromatic, telomere clusters and var switching are independent but are both affected by subtelomeric sequences. The var expression site colocalised with the euchromatic mark H3K27ac to a greater extent than it did with heterochromatic H3K9me3. H3K27ac was enriched within the active var gene promoter even when the var gene was transiently repressed in mature parasites and thus H3K27ac may contribute to var gene epigenetic memory. © 2016 Federation of European Biochemical Societies.

Fructanase and fructosyltransferase activity of non-Saccharomyces yeasts isolated from fermenting musts of Mezcal.

Science.gov (United States)

Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

2012-04-01

Fructanase and fructosyltransferase are interesting for the tequila process and prebiotics production (functional food industry). In this study, one hundred thirty non-Saccharomyces yeasts isolated from "Mezcal de Oaxaca" were screened for fructanase and fructosyltransferase activity. On solid medium, fifty isolates grew on Agave tequilana fructans (ATF), inulin or levan. In liquid media, inulin and ATF induced fructanase activities of between 0.02 and 0.27U/ml depending of yeast isolate. High fructanase activity on sucrose was observed for Kluyveromyces marxianus and Torulaspora delbrueckii, while the highest fructanase activity on inulin and ATF was observed for Issatchenkia orientalis, Cryptococcus albidus, and Candida apicola. Zygosaccharomyces bisporus and Candida boidinii had a high hydrolytic activity on levan. Sixteen yeasts belonging to K. marxianus, T. delbrueckii and C. apicola species were positive for fructosyltransferase activity. Mezcal microbiota proved to showed to be a source for new fructanase and fructosyltransferases with potential application in the tequila and food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification of a novel vitivirus from grapevines in New Zealand.

Science.gov (United States)

Blouin, Arnaud G; Keenan, Sandi; Napier, Kathryn R; Barrero, Roberto A; MacDiarmid, Robin M

2018-01-01

We report a sequence of a novel vitivirus from Vitis vinifera obtained using two high-throughput sequencing (HTS) strategies on RNA. The initial discovery from small-RNA sequencing was confirmed by HTS of the total RNA and Sanger sequencing. The new virus has a genome structure similar to the one reported for other vitiviruses, with five open reading frames (ORFs) coding for the conserved domains described for members of that genus. Phylogenetic analysis of the complete genome sequence confirmed its affiliation to the genus Vitivirus, with the closest described viruses being grapevine virus E (GVE) and Agave tequilana leaf virus (ATLV). However, the virus we report is distinct and shares only 51% amino acid sequence identity with GVE in the replicase polyprotein and 66.8% amino acid sequence identity with ATLV in the coat protein. This is well below the threshold determined by the ICTV for species demarcation, and we propose that this virus represents a new species. It is provisionally named "grapevine virus G".

Rediscovery of Impatiens laevigata var. grandifolia (Balsaminaceae from NE India

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R. Gogoi

2013-12-01

Full Text Available Impatiens laevigata var. grandifolia Hook.f. rediscovered after a lapse of 139 years from Lohit district of Arunachal Pradesh. Earlier it was known only – from its type locality in Manipur. Detailed morphological description of I. laevigata var. laevigata and var. grandifolia have been provided based on fresh plant collections.

Genetic analisys of a cross of gaillon (Brassica oleracea var. alboglabra) with cauliflower (B.oleracea var. botrytis)

OpenAIRE

Spini, Vanessa B.M.G.; Kerr, Warwick Estevam

2000-01-01

The cauliflower (Brassica oleracea var. botrytis) is an annual vegetable cultivated in Southern and Southwestern Brazil with limited production in the Northeast and Centralwest. A variety of Chinese kale, "kaai laan" or "gaillon" (Brassica oleracea var. alboglabra), produces seeds at high temperatures and therefore can do so in North and Northeastern Brazil. Gaillon and cauliflower were crossed 55 times using 10 gaillon plants as mothers and 4 cauliflower plants as pollen donors. From these c...

A system dynamics model integrating physiology and biochemical regulation predicts extent of crassulacean acid metabolism (CAM) phases.

Science.gov (United States)

Owen, Nick A; Griffiths, Howard

2013-12-01

A system dynamics (SD) approach was taken to model crassulacean acid metabolism (CAM) expression from measured biochemical and physiological constants. SD emphasizes state-dependent feedback interaction to describe the emergent properties of a complex system. These mechanisms maintain biological systems with homeostatic limits on a temporal basis. Previous empirical studies on CAM have correlated biological constants (e.g. enzyme kinetic parameters) with expression over the CAM diel cycle. The SD model integrates these constants within the architecture of the CAM 'system'. This allowed quantitative causal connections to be established between biological inputs and the four distinct phases of CAM delineated by gas exchange and malic acid accumulation traits. Regulation at flow junctions (e.g. stomatal and mesophyll conductance, and malic acid transport across the tonoplast) that are subject to feedback control (e.g. stomatal aperture, malic acid inhibition of phosphoenolpyruvate carboxylase, and enzyme kinetics) was simulated. Simulated expression for the leaf-succulent Kalanchoë daigremontiana and more succulent tissues of Agave tequilana showed strong correlation with measured gas exchange and malic acid accumulation (R(2)  = 0.912 and 0.937, respectively, for K. daigremontiana and R(2)  = 0.928 and 0.942, respectively, for A. tequilana). Sensitivity analyses were conducted to quantitatively identify determinants of diel CO2 uptake. The transition in CAM expression from low to high volume/area tissues (elimination of phase II-IV carbon-uptake signatures) was achieved largely by the manipulation three input parameters. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Larvicidal Activity of Isodon japonicus var. glaucocalyx (Maxim ...

African Journals Online (AJOL)

HP

Purpose: To determine the larvicidal activity of the essential oil derived from Isodon japonicus var. ... Methods: The essential oil of I. japonicus var. glaucocalyx aerial parts was obtained by ..... µg/mL; G. silvatica leaves, LC50 = 117.9 µg/mL.

Evaluation of anthelmintic activity of liquid waste of Agave sisalana (sisal in goats Avaliação da atividade anti-helmíntica do resíduo líquido de Agave sisalana (sisal em caprinos

Directory of Open Access Journals (Sweden)

Luciana Ferreira Domingues

2010-12-01

Full Text Available It was evaluated the anthelmintic activity of Agave sisalana (sisal juice against gastrointestinal nematodes and its potential toxic effects in goats. In vitro tests showed more than 95% reduction in larval counts of the genus Haemonchus spp. at concentrations between 86.5 and 146.3 mg.mL-1. In vivo the percent reduction of larvae of the fourth (L4 and fifth (L5 stages of Haemonchus, Oesophagostomum and Trichostrongylus was less than 95% in groups GI and GII, and between 80 and 90% in group GIII. A. sisalana juice at the concentrations tested in vitro was effective against gastrointestinal nematodes in goats; however, its anthelmintic efficacy was reduced when administered to animals.Foi avaliada a atividade anti-helmíntica do suco de Agave sisalana (sisal contra nematódeos gastrintestinais e possíveis efeitos tóxicos em caprinos. Nos testes in vitro, encontrou-se redução superior a 95% na contagem de larvas do gênero Haemonchus spp. nas concentrações entre 86,5 e 146,3 mg.mL-1. In vivo, o percentual de redução de larvas de quarto (L4 e quinto (L5 estágios de Haemonchus, Oesophagostomum e Trichostrongylus foi inferior a 95% para o GI e GII, e entre 80 e 90% para o GIII. O suco de A. sisalana nas concentrações testadas in vitro foi efetivo contra nematódeos gastrintestinais de caprinos, apresentando, no entanto, reduzida eficácia anti-helmíntica quando administrado nos animais.

ClinVar data parsing [version 1; referees: 2 approved

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Xiaolei Zhang

2017-05-01

Full Text Available This software repository provides a pipeline for converting raw ClinVar data files into analysis-friendly tab-delimited tables, and also provides these tables for the most recent ClinVar release. Separate tables are generated for genome builds GRCh37 and GRCh38 as well as for mono-allelic variants and complex multi-allelic variants. Additionally, the tables are augmented with allele frequencies from the ExAC and gnomAD datasets as these are often consulted when analyzing ClinVar variants. Overall, this work provides ClinVar data in a format that is easier to work with and can be directly loaded into a variety of popular analysis tools such as R, python pandas, and SQL databases.

Pitfalls in VAR based return decompositions: A clarification

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

in their analysis is not "cashflow news" but "inter- est rate news" which should not be zero. Consequently, in contrast to what Chen and Zhao claim, their decomposition does not serve as a valid caution against VAR based decompositions. Second, we point out that in order for VAR based decompositions to be valid......Based on Chen and Zhao's (2009) criticism of VAR based return de- compositions, we explain in detail the various limitations and pitfalls involved in such decompositions. First, we show that Chen and Zhao's interpretation of their excess bond return decomposition is wrong: the residual component...

What is Orobanche haenseleri var. deludens Beck?

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Pujadas Salvà, Antonio J.

2004-12-01

Full Text Available Orobanche haenseleri var. deludens Beck (Orobanchaceae, a problematic taxon described from Algeciras (Cádiz, S Spain is here identified after studying the original material of Wolley-Dod (BM 4476. It is considered to be the same as O. austrohispanica M.J.Y. Foley and better included, as a variety, under O. gracilis Sm. The new combination O. gracilis var. deludens (Beck A. Pujadas is consequently proposed. It mainly parasites Ulex (Fabaceae in the western Mediterranean Region (Iberian Peninsula and NW Africa.Se identifica Orobanche haenseleri var. deludens Beck (Orobanchaceae, un taxon conflictivo descrito de Algeciras (Cádiz, sur de España, a partir del análisis del material original de Wolley-Dod (BM 4476. Se considera que es lo mismo que O. austrohispanica M.J.Y. Foley, y se incluye en O. gracilis Sm. con rango varietal. Se propone la nueva combinación O. gracilis var. deludens (Beck A. Pujadas. Parasita principalmente a especies del género Ulex (Fabaceae en la Región Mediterránea Occidental (Península Ibérica y noroeste de África.

Growth and provenance variation of Pinus caribaea var ...

African Journals Online (AJOL)

CAMCORE has visited 33 populations of Pinus caribaea var. hondurensis in Belize, Guatemala, Honduras, El Salvador, Nicaragua, and Quintana Roo, Mexico. Seed collections have been made in 29 provenances from 1, 325 mother trees. A total of 21 provenances and sources of Pinus caribaea var. hondurensis were ...

Empirical analysis on future-cash arbitrage risk with portfolio VaR

Science.gov (United States)

Chen, Rongda; Li, Cong; Wang, Weijin; Wang, Ze

2014-03-01

This paper constructs the positive arbitrage position by alternating the spot index with Chinese Exchange Traded Fund (ETF) portfolio and estimating the arbitrage-free interval of futures with the latest trade data. Then, an improved Delta-normal method was used, which replaces the simple linear correlation coefficient with tail dependence correlation coefficient, to measure VaR (Value-at-risk) of the arbitrage position. Analysis of VaR implies that the risk of future-cash arbitrage is less than that of investing completely in either futures or spot market. Then according to the compositional VaR and the marginal VaR, we should increase the futures position and decrease the spot position appropriately to minimize the VaR, which can minimize risk subject to certain revenues.

Quercetin - A Flavonoid Compound from Sarcopyramis bodinieri var ...

African Journals Online (AJOL)

DAPI staining and PARP SDS-PAGE tests showed 60 μM quercetin could induce potential apoptotic activity in HepG2 liver cancer cells. Conclusion: Quercetin was the major cytotoxicity constituent in S. bodinieri var. delicate. Keywords: Apoptotic activity, Quercetin, Sarcopyramis bodinieri var. delicate, HepG2 liver cancer ...

Identification of the relationship between Chinese Adiantum reniforme var. sinense and Canary Adiantum reniforme.

Science.gov (United States)

Wang, Ai-Hua; Sun, Ye; Schneider, Harald; Zhai, Jun-Wen; Liu, Dong-Ming; Zhou, Jin-Song; Xing, Fu-Wu; Chen, Hong-Feng; Wang, Fa-Guo

2015-02-05

There are different opinions about the relationship of two disjunctively distributed varieties Adiantum reniforme L. var. sinense Y.X.Lin and Adiantum reniforme L. Adiantum reniforme var. sinense is an endangered fern only distributed in a narrowed region of Chongqing city in China, while Adiantum reniforme var. reniforme just distributed in Canary Islands and Madeira off the north-western African coast. To verify the relationship of these two taxa, relative phylogenetic analyses, karyotype analyses, microscopic spore observations and morphological studies were performed in this study. Besides, divergence time between A. reniforme var. sinense and A. reniforme var. reniforme was estimated using GTR model according to a phylogeny tree constructed with the three cpDNA markers atpA, atpB, and rbcL. Phylogenetic results and divergence time analyses--all individuals of A. reniforme var. sinense from 4 different populations (representing all biogeographic distributions) were clustered into one clade and all individuals of A. reniforme var. reniforme from 7 different populations (all biogeographic distributions are included) were clustered into another clade. The divergence between A. reniforme var. reniforme and A. reniforme var. sinense was estimated to be 4.94 (2.26-8.66) Myr. Based on karyotype analyses, A. reniforme var. reniforme was deduced to be hexaploidy with 2n = 180, X = 30, while A. reniforme var. sinense was known as tetraploidy. Microscopic spore observations suggested that surface ornamentation of A. reniforme var. reniforme is psilate, but that of A. reniforme var. sinense is rugate. Leaf blades of A. reniforme var. sinense are membranous and reniform and with several obvious concentric rings, and leaves of A. reniforme var. reniforme are pachyphyllous and coriaceous and are much rounder and similar to palm. Adiantum reniforme var. sinense is an independent species rather than the variety of Adiantum reniforme var. reniforme. As a result, we

Foco de leishmaniasis en El Hobo, municipio de El Carmen de Bolívar, Bolívar, Colombia

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Luis Alberto Cortés

2006-10-01

Full Text Available Introducción. Se describen las características epidemiológica e importancia de la especies de Lutzomyia presentes en un foco de leishmaniasis en la vereda El Hobo Carmen de Bolívar, departamento de Bolívar. Objetivos. Obtener un conocimiento preliminar de la transmisión de leishmaniasis en la vereda El Hobo Carmen de Bolívar. Materiales y métodos. Se analizaron datos epidemiológicos y se realizaron capturas de flebótomos con trampas CDC y cebo humano en la vereda El Hobo. Para establecer la sero prevalencia de leishmaniasis visceral canina se hizo un estudio en perros mediante la técnica de inmunofluorescencia indirecta. Resultados. Se capturaron nueve especies de Lutzomyia: L. trinidadensis, L. evansi, L .cayennensis, L. venezuelensis, L. gomezi,L. dubitans, L. ylephiletor, L. yuilli, y L. walkeri. Las especie de mayor importancia por sus implicaciones en la transmisión de leishmaniasis cutánea y visceral fueron L. gomezi, y L. evansi respectivamente. Se reporta por primera vez para Bolívar especimenes de L. venezuelensis, L. dubitans, L. ylephiletor, L. yuilli, y L. walkeri. Se determinó una prevalencia de leishmaniasis visceral del 36% en los caninos estudiados. Según los reportes epidemiológicos, en el 2002 en el municipio de Carmen de Bolívar la leishmaniasis cutánea mostró un aumento del 40% y la leishmaniasis visceral canina del 80% de los casos con respecto al 2001, debido al brote presentado en la vereda El Hobo Conclusiones. Los resultados determinan a la vereda El Hobo como una zona de riesgo potencial de transmisión de leishmaniasis cutánea y visceral.

Phosphorylation of SU(VAR3-9 by the chromosomal kinase JIL-1.

Directory of Open Access Journals (Sweden)

Joern Boeke

2010-04-01

Full Text Available The histone methyltransferase SU(VAR3-9 plays an important role in the formation of heterochromatin within the eukaryotic nucleus. Several studies have shown that the formation of condensed chromatin is highly regulated during development, suggesting that SU(VAR3-9's activity is regulated as well. However, no mechanism by which this may be achieved has been reported so far. As we and others had shown previously that the N-terminus of SU(VAR3-9 plays an important role for its activity, we purified interaction partners from Drosophila embryo nuclear extract using as bait a GST fusion protein containing the SU(VAR3-9 N-terminus. Among several other proteins known to bind Su(VAR3-9 we isolated the chromosomal kinase JIL-1 as a strong interactor. We show that SU(VAR3-9 is a substrate for JIL-1 in vitro as well as in vivo and map the site of phosphorylation. These findings may provide a molecular explanation for the observed genetic interaction between SU(VAR3-9 and JIL-1.

21 CFR 173.145 - Alpha-Galactosidase derived from Mortierella vinaceae var. raffinoseutilizer.

Science.gov (United States)

2010-04-01

... vinaceae var. raffinoseutilizer. 173.145 Section 173.145 Food and Drugs FOOD AND DRUG ADMINISTRATION... Alpha-Galactosidase derived from Mortierella vinaceae var. raffinoseutilizer. The food additive alpha-galactosidase and parent mycelial microorganism Mortierella vinaceae var. raffinoseutilizer may be safely used...

Comparative ozone responses of cutleaf coneflowers (Rudbeckia laciniata var. digitata, var. ampla) from Rocky Mountain and Great Smoky Mountains National Parks, USA.

Science.gov (United States)

Neufeld, Howard S; Johnson, Jennifer; Kohut, Robert

2018-01-01

Cutleaf coneflower (Rudbeckia laciniata L. var. digitata) is native to Great Smoky Mountains National Park (GRSM) and an ozone bioindicator species. Variety ampla, whose ozone sensitivity is less well known, is native to Rocky Mountain National Park (ROMO). In the early 2000s, researchers found putative ozone symptoms on var. ampla and rhizomes were sent to Appalachian State University to verify that the symptoms were the result of ozone exposure. In 2011, potted plants were exposed to ambient ozone from May to August. These same plants were grown in open-top chambers (OTCs) in 2012 and 2013, and exposed to charcoal-filtered (CF), non-filtered (NF), elevated ozone (EO), NF+50ppb in 2012 for 47days and NF+30/NF+50ppb ozone in 2013 for 36 and 36days, respectively. Ozone symptoms similar to those found in ROMO (blue-black adaxial stippling) were reproduced both in ambient air and in the OTCs. Both varieties exhibited foliar injury in the OTCs in an exposure-dependent manner, verifying that symptoms resulted from ozone exposure. In two of the three study years, var. digitata appeared more sensitive than var. ampla. Exposure to EO caused reductions in ambient photosynthetic rate (A) and stomatal conductance (g s ) for both varieties. Light response curves indicated that ozone reduced A, g s , and the apparent quantum yield while it increased the light compensation point. In CF air, var. ampla had higher light saturated A (18.2±1.04 vs 11.6±0.37μmolm -2 s -1 ), higher light saturation (1833±166.7 vs 1108±141.7μmolm -2 s -1 ), and lower Ci/Ca ratio (0.67±0.01 vs 0.77±0.01) than var. digitata. Coneflowers in both Parks are adversely affected by exposure to ambient ozone and if ozone concentrations increase in the Rocky Mountains, greater amounts of injury on var. ampla can be expected. Copyright © 2017 Elsevier B.V. All rights reserved.

VAr reserve concept applied to a wind power plant

DEFF Research Database (Denmark)

Martinez, Jorge; Kjær, Philip C.; Rodriguez, Pedro

2011-01-01

to wind power plants. This paper proposes two different VAr reserve control strategies for a wind power plant. The amount of dynamic VAr available most of the operation time, makes the wind power plant (WPP) a good candidate to include a VAr reserve management system. Two different ways of implementing...... a VAr management system are proposed and analyzed. Such a reactive power reserve may be provided by the wind power plant since the amount of reactive power installed for most active power working points exceeds the demand required by the grid operator. Basically, this overrated reactive power capacity...... is a consequence of sizing wind turbine facilities for maximum active power level. The reactive power losses, due to active power transportation inside the plant (normally two transformers), and P-Q wind turbine characteristics define the P-Q reserve chart. By utilizing the intrinsic overrated reactive power...

A comprehensive market-based scheme for VAR management and pricing in the electricity markets

Energy Technology Data Exchange (ETDEWEB)

El-Araby, E.E. [Qassim Univ., Alqassim, Meldia (Saudi Arabia). Dept. of Electrical Engineering

2009-07-01

In order to enable a power system to operate within an acceptable degree of reliability and security, the provision of VAR ancillary services from the VAR sources in electricity markets is the most effective method. The procurement of VAR services is particularly problematic for transmission operators as it relates to pricing mechanism and various technical issues during system operation. This paper proposed an integrated market-based approach for pricing VAR service in the electricity market. The paper was an extension of the authors' proposal for the provision of the VAR service from dynamic VAR sources in a competitive market-based environment. The formulation was modified to include VAR utilization payment and possible power system transition states multiple base cases and contingencies with their associated occurrence probabilities. The paper discussed the basic terms of the proposed approach including the VAR market objective and generator VAR output and its compensation. The mathematical formulation that considered VAR capacity payment, utilization payment and operating costs under the previous transition states in a unified single problem were introduced. The overall problem formulation and solution algorithm were also presented as a large-scale mixed integer nonlinear optimization problem. It was concluded that the proposed method was suited for the simulation and analysis of the existing VAR market. 8 refs., 3 tabs., 5 figs., 2 appendices.

METODE VECTOR AUTOREGRESSIVE (VAR DALAM PERAMALAN JUMLAH WISATAWAN MANCANEGARA KE BALI

Directory of Open Access Journals (Sweden)

TJOK GDE SAHITYAHUTTI RANANGGA

2018-05-01

Full Text Available The purposes of this research were to model and to forecast the number of foreign tourists (Australia, China, and Japan arrival to Bali using vector autoregressive (VAR method. The estimated of VAR model obtained to forecast the number of foreign tourists to Bali is the sixth order VAR (VAR(6.We used multivariate least square method to estimate the VAR(6’s parameters.The mean absolute percentage error (MAPE in this model were as follows 6.8% in predicting the number of Australian tourists, 15.9% in predicting the number of Chinese tourists, and 9% in predicting the number of Japanese tourists. The prediction of Australian, Chinese, and Japanese tourists arrival to Bali for July 2017 to December 2017 tended  to experience up and downs that were not too high compared to the previous months.

To the issue of increasing efficiency of VAR compensation

Directory of Open Access Journals (Sweden)

Світлана Костянтинівна Поднебенна

2015-11-01

Full Text Available This article describes the features of VAR compensation of variable loads. One of the most common non-symmetric non-linear power consumers are welding power sources. Time and duration of the work of these sources vary randomly. To compensate the consumption of reactive power on the basis of consumption data from the three-phase electricity meters is inefficient. Compensation devices power should be calculated taking into account the asymmetrical consumption/generation of reactive power per phase and changing consumption patterns. Thyristor-controlled reactor, thyristor-switched capacitors, hybrid VAR compensators, active compensators (STATCOMs, «dynamic capacitors» can be used as the VAR compensation devices. Thyristor-controlled reactors can provide smooth regulation of reactive power, but they have high weight and size parameters and are additional sources of higher harmonics. Thyristor-switched capacitors provide stepwise adjustment of reactive power and are subject to the current higher harmonics. Hybrid VAR compensators make it possible to isolate capacitors from the higher harmonics and ensure smooth regulation, which is achieved by active filter introduction to the reactive power compensation devices based on thyristor-switched capacitors. However, this increases the cost of a compensator and complicates its control system. STATCOMs provide smooth regulation of reactive power, but they are too expensive.Perspective direction in the development of effective VAR compensation devices is «dynamic capacitor». As a result of a feasibility study the prospects for further research of electrical grids power efficiency through the development of effective devices for VAR compensation have been established

How can the origin of the decay var-phi →3π be determined?

International Nuclear Information System (INIS)

Achasov, N.N.; Kozhevnikov, A.A.

1992-01-01

It is shown that the interference pattern in the region √s = 1.05 GeV in the reaction e + e - →ω, var-phi →3π can be used to determine unambiguously whether the decay var-phi →3π occurs because of var-phi ω mixing, var-phi →ω→3π, or because of the direct transition var-phi →3π. 8 refs., 3 figs., 1 tab

VAR, stress-testing and supplementary methodologies: uses and constraints in energy risk management

International Nuclear Information System (INIS)

Senior, Brian

1999-01-01

This chapter lists some of the special risks associated with a range of energy markets, and questions what is risk. Market risk, the use of value-at-risk (VAR) for measuring and managing market risk, use of VAR in the banking sector, back-testing of VAR, the corporate sector, making investment decisions, and the need for additional methods of risk analysis are discussed. Scenario analysis and stress testing, liquidity, and combining VAR and stress-testing are described. Credit risk and the quantitative analysis of credit risk are addressed, and operational risk, and organisational challenges are considered. Panels present examples of a simple VAR calculation and give descriptions of VAR in corporate decisions, the measurement of liquidity, and the use of the Greeks in decisions on day to day trading and risk management

The effect of agave fructan products on the activity and composition of the microbiota determined in a dynamic in vitro model of the human proximal large intestine

NARCIS (Netherlands)

Koenen, M.E.; Cruz Rubio, J.M.; Mueller, M.; Venema, K.

2016-01-01

Inulin and trans-galactooligosaccharides have so far fully met the criteria for prebiotics. This study shows the effect of putative prebiotics Metlos and Metlin (short and medium chain branched fructans from agave) on the activity and composition of the gut microbiota compared to the effects of two

Computing level-impulse responses of log-specified VAR systems

NARCIS (Netherlands)

Wieringa, J.E.; Horvath, C.

2005-01-01

Impulse response functions (IRFs) are often used to analyze the dynamic behavior of a vector autoregressive (VAR) system. In many applications of VAR modelling, the variables are log-transformed before the model is estimated. If this is the case, the results of the IRFs do not have a direct

EFEITO FUNGITÓXICO DO ÓLEO DE NIM SOBRE Metarhizium anisopliae var. acridum e Metarhizium anisopliae var. anisopliae

Directory of Open Access Journals (Sweden)

Álison Bruno da Silva Santos

2009-01-01

Full Text Available Plague control is based almost exclusively on application of chemical substances, however these products are toxic to men and animals and cause odd effects on environment quality. In Plague Integrated Management (PIM, the use of selected insecticides and entomopathogenic fungi should be considered as one viable strategy for plague control in agriculture. This work aimed to evaluate, in laboratory, the compatibility of the entomopathogenic fungi Metarhizium anisopliae var. acridum and Metarhizium anisopliae var. anisopliae with the oil of Nim. The addition of the product was made to the potato-dextrose-agar medium still liquid (±45°C, in a way that the final concentration obeyed 50% of the producer's recommendation. After fungi inoculation, the dishes were incubated in a cimatized room at 28°C, photophase of 12 hours and relative humidity of 75±5% for 12 day period. The number of conidia per colonie was counted with a Neubauer chamber. Statistic delineament was entirely in random, with two treatments (PDA with insecticide, and a control group (PDA without insecticide, and 9 repetitions for each treatment. The results showed that the insecticide inhibited conidial production in Metarhizium anisopliae var. anisopliae strains when compared to the control group. The diameter of Metarhizium anisopliae var. acridum colonies suffered significative reduction in its size, compared to control. The tested insecticide, in the concentration and formulation used, presented compatibility with the tested strains.

Sincronía reproductiva interpoblacional de Agave cocui (Agavaceae en Venezuela

Directory of Open Access Journals (Sweden)

Carmen J Figueredo

2011-09-01

Full Text Available cocui (Agavaceae es una especie de amplia distribución en zonas áridas y semiáridas de Venezuela y Colombia. A pesar de su importancia ecológica como fuente de recursos para la fauna silvestre y de su potencial valor económico como materia prima para la producción del licor “Cocuy de Penca”, los estudios sobre su ecología reproductiva son muy escasos. En este estudio se evaluó la fenología de floración y fructificación de A. cocui en ocho localidades de Venezuela. La fase reproductiva se inició al finalizar el periodo de lluvias. Las flores se producen durante cinco meses. Para la Región Noroccidental del país y los Andes los máximos de floración ocurrieron en enero, mientras que las localidades en la costa central y oriental exhibieron un desface de cerca de dos meses, a principios de marzo. La mayor sincronía floral ocurrió entre todas las poblaciones censadas en el occidente del país, incluyendo las localidades andinas. Dicha sincronía reproductiva potenciaría la conformación de un corredor de néctar para aves y murciélagos, que se extendería desde el Norte de Falcón, en la Costa Occidental, hasta los bolsones andinos, en el Suroeste del país.Interpopulation reproductive synchrony of Agave cocui (Agavaceae in Venezuela. Agave cocui (Agavaceae is a species with broad distribution in arid and semiarid areas of Venezuela and Colombia. Despite of its ecological importance as a source of food for wildlife, and its economic value for production of a spirit drink, studies on the reproductive ecology of the species are relatively rare. In this study, we conducted a oneyear evaluation of the flowering and fruiting phenology of A. cocui in the eight representative localities of the species’ distribution in Venezuela. Within each study site, we chose an area with a minimum of 50 reproductive individuals and followed their reproductive phenophases with the help of binoculars, using six qualitative cathegories (emerging

Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment

OpenAIRE

Appel-da-Silva, Marcelo C.; Narvaez, Gabriel A.; Perez, Leandro R.R.; Drehmer, Laura; Lewgoy, Jairo

2017-01-01

Probiotics are commonly prescribed as an adjuvant in the treatment of antibiotic-associated diarrhea caused by Clostridium difficile. We report the case of an immunocompromised 73-year-old patient on chemotherapy who developed Saccharomyces cerevisiae var. boulardii fungemia in a central venous catheter during treatment of antibiotic-associated pseudomembranous colitis with the probiotic Saccharomyces cerevisiae var. boulardii. Fungemia was resolved after interruption of probiotic administrat...

Genomic resources and draft assemblies of the human and porcine varieties of scabies mites, Sarcoptes scabiei var. hominis and var. suis.

Science.gov (United States)

Mofiz, Ehtesham; Holt, Deborah C; Seemann, Torsten; Currie, Bart J; Fischer, Katja; Papenfuss, Anthony T

2016-06-02

The scabies mite, Sarcoptes scabiei, is a parasitic arachnid and cause of the infectious skin disease scabies in humans and mange in other animal species. Scabies infections are a major health problem, particularly in remote Indigenous communities in Australia, where secondary group A streptococcal and Staphylococcus aureus infections of scabies sores are thought to drive the high rate of rheumatic heart disease and chronic kidney disease. We sequenced the genome of two samples of Sarcoptes scabiei var. hominis obtained from unrelated patients with crusted scabies located in different parts of northern Australia using the Illumina HiSeq. We also sequenced samples of Sarcoptes scabiei var. suis from a pig model. Because of the small size of the scabies mite, these data are derived from pools of thousands of mites and are metagenomic, including host and microbiome DNA. We performed cleaning and de novo assembly and present Sarcoptes scabiei var. hominis and var. suis draft reference genomes. We have constructed a preliminary annotation of this reference comprising 13,226 putative coding sequences based on sequence similarity to known proteins. We have developed extensive genomic resources for the scabies mite, including reference genomes and a preliminary annotation.

[Autotoxicity of aqueous extracts from plant of cultivated Astragalus membranaceus var. mongholicus].

Science.gov (United States)

Zhang, Xin-Hui; Lang, Duo-Yong; Chen, Jing; Zhao, Yun-Sheng; Wu, Xiu-Li; Fu, Xue-Yan

2014-02-01

To exploring the relationship between continuous cropping obstacle and autotoxicity of Astragalus membranaceus var. mongholicus, autotoxic effect of plant aqueous extract were determined. Distilled water (CK), aqueous extract of plant, including root, stem and leaf (12.5, 25, 50 and 100 mg/mL respectively)were applied to testing their effect on early growth of Astragalus membranaceus var. mongholicus. Specifically, seed germination rate, germination index, emergence rate, elongation of radical and embryo, and seedling vigor index were determined. The aqueous extract of root, stem, and leaf at 25 mg/mL significantly inhibited the seed germination and seedling growth of Astragalus membranaceus var. mongholicus, and this inhibitory effect generally increased with the increase of the concentration of aqueous extracts. To the comprehensive allelopathic effect, the extracts from Astragalus membranaceus var. mongholicus stem were more inhibitory than those from leaf and root. The germination index and seedling vigor index were more sensitive to extract than other determined parameters. Aqueous extracts from Astragalus membranaceus var. mongholicus plant gave inhibitory effects on Astragalus. membranaceus var. mongholicus germination and seedling growth, and this inhibitory effect generally increased with the increases of aqueous extract concentration at a certain ranges. In conclusion, there is an autotoxicity in continuous cropping of Astragalus membranaceus var. mongholicus.

Physiological differences and changes in global DNA methylation levels in Agave angustifolia Haw. albino variant somaclones during the micropropagation process.

Science.gov (United States)

Duarte-Aké, Fátima; Castillo-Castro, Eduardo; Pool, Felipe Barredo; Espadas, Francisco; Santamaría, Jorge M; Robert, Manuel L; De-la-Peña, Clelia

2016-12-01

Global DNA methylation changes caused by in vitro conditions are associated with the subculturing and phenotypic variation in Agave angustifolia Haw. While the relationship between the development of albinism and in vitro culture is well documented, the role of epigenetic processes in this development leaves some important questions unanswered. During the micropropagation of Agave angustifolia Haw., we found three different phenotypes, green (G), variegated (V) and albino (A). To understand the physiological and epigenetic differences among the somaclones, we analyzed several morphophysiological parameters and changes in the DNA methylation patterns in the three phenotypes during their in vitro development. We found that under in vitro conditions, the V plantlets maintained their CAM photosynthetic capacity, while the A variant showed no pigments and lost its CAM photosynthetic ability. Epigenetic analysis revealed that global DNA methylation increased in the G phenotype during the first two subcultures. However, after that time, DNA methylation levels declined. This hypomethylation correlated with the appearance of V shoots in the G plantlets. A similar correlation occurred in the V phenotype, where an increase of 2 % in the global DNA methylation levels was correlated with the generation of A shoots in the V plantlets. This suggests that an "epigenetic stress memory" during in vitro conditions causes a chromatin shift that favors the generation of variegated and albino shoots.

[Photosynthetic parameters and physiological indexes of Paris polyphylla var. yunnanensis influenced by arbuscular mycorrhizal fungi].

Science.gov (United States)

Wei, Zheng-xin; Guo, Dong-qin; Li, Hai-feng; Ding, Bo; Zhang, Jie; Zhou, Nong; Yu, Jie

2015-10-01

Through potted inoculation test at room temperature and indoor analysis, the photosynthetic parameters and physiological and biochemical indexes of Paris polyphylla var. yunnanensis were observed after 28 arbuscular mycorrhizal (AM) fungi were injected into the P. polyphylla var. yunnanensis growing in a sterile soil environment. The results showed that AM fungi established a good symbiosis with P. polyphylla var. yunnanensis. The AM fungi influenced the photosynthetic parameters and physiological and biochemical indexes of P. polyphylla var. yunnanensis. And the influences were varied depending on different AM fungi. The application of AM fungi improved photosynthesis intensity of P. polyphylla var. yunnanensis mesophyll cells, the contents of soluble protein and soluble sugar, protective enzyme activity of P. polyphylla var. yunnanensis leaf, which was beneficial to resist the adverse environment and promote the growth of P. polyphylla var. yunnanensis. Otherwise, there was a certain mutual selectivity between P. polyphylla var. yunnanensis and AM fungi. From the comprehensive effect of inoculation, Racocetra coralloidea, Scutellospora calospora, Claroideoglomus claroideum, S. pellucida and Rhizophagus clarus were the most suitable AM fungi to P. polyphylla var. yunnanensis when P. polyphylla var. yunnanensis was planted in the field.

Morphological variation, management and domestication of 'maguey alto' (Agave inaequidens) and 'maguey manso' (A. hookeri) in Michoacán, México.

Science.gov (United States)

Figueredo, Carmen Julia; Casas, Alejandro; Colunga-GarcíaMarín, Patricia; Nassar, Jafet M; González-Rodríguez, Antonio

2014-09-16

Agave inaequidens and A. hookeri are anciently used species for producing the fermented beverage 'pulque', food and fiber in central Mexico. A. inaequidens is wild and cultivated and A. hookeri only cultivated, A. inaequidens being its putative wild relative. We analysed purposes and mechanisms of artificial selection and phenotypic divergences between wild and managed populations of A. inaequidens and between them and A. hookeri, hypothesizing phenotypic divergence between wild and domesticated populations of A. inaequidens in characters associated to domestication, and that A. hookeri would be phenotypically similar to cultivated A. inaequidens. We studied five wild and five cultivated populations of A. inaequidens, and three cultivated populations of A. hookeri. We interviewed agave managers documenting mechanisms of artificial selection, and measured 25 morphological characters. Morphological similarity and differentiation among plants and populations were analysed through multivariate methods and ANOVAs. People recognized 2-8 variants of A. inaequidens; for cultivation they select young plants collected in wild areas recognized as producing the best quality mescal agaves. Also, they collect seeds of the largest and most vigorous plants, sowing seeds in plant beds and then transplanting the most vigorous plantlets into plantations. Multivariate methods classified separately the wild and cultivated populations of A. inaequidens and these from A. hookeri, mainly because of characters related with plant and teeth size. The cultivated plants of A. inaequidens are significantly bigger with larger teeth than wild plants. A. hookeri are also significatly bigger plants with larger leaves but lower teeth density and size than A. inaequidens. Some cultivated plants of A. inaequidens were classified as A. hookeri, and nearly 10% of A. hookeri as cultivated A. inaequidens. Wild and cultivated populations of A. inaequidens differed in 13 characters, whereas A. hookeri

Characterization of volatile compounds of Mezcal, an ethnic alcoholic beverage obtained from Agave salmiana.

Science.gov (United States)

De León-Rodríguez, Antonio; González-Hernández, Lidia; Barba de la Rosa, Ana P; Escalante-Minakata, Pilar; López, Mercedes G

2006-02-22

Commercial mezcals (white, white with worm, rested, rested with worm, and aged) produced from Agave salmiana were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). Thirty-seven compounds were identified, and nine of them were classified as major compounds of mezcal (MCM). Saturated alcohols, ethyl acetate, ethyl 2-hydroxypropanoate, and acetic acid form the MCM group. Minor compounds of mezcal group include other alcohols, aldehydes, ketones, large chain ethyl esters, organic acids, furans, terpenes, alkenes, and alkynes. Most of the compounds found in mezcals in this study are similar to those present in tequilas and other alcoholic beverages. However, mezcals contain unique compounds such as limonene and pentyl butanoate, which can be used as markers for the authenticity of mezcal produced from A. salmiana.

Haavelmo's Probability Approach and the Cointegrated VAR

DEFF Research Database (Denmark)

Juselius, Katarina

Some key econometric concepts and problems addressed by Trygve Haavelmo and Ragnar Frisch are discussed within the general frame- work of a cointegrated VAR. The focus is on problems typical of time- series data such as multicollinearity, spurious correlation and regres- sion results, time......) the plausibility of the multivari- ate normality assumption underlying the VAR, (3) cointegration as a solution to the problem of spurious correlation and multicollinearity when data contain deterministic and stochastic trends, (4) the exis- tence of a universe, (5) the association between Frisch’s con...

Comparison of historically simulated VaR: Evidence from oil prices

International Nuclear Information System (INIS)

Costello, Alexandra; Asem, Ebenezer; Gardner, Eldon

2008-01-01

Cabedo and Moya [Cabedo, J.D., Moya, I., 2003. Estimating oil price 'Value at Risk' using the historical simulation approach. Energy Economics 25, 239-253] find that ARMA with historical simulation delivers VaR forecasts that are superior to those from GARCH. We compare the ARMA with historical simulation to the semi-parametric GARCH model proposed by Barone-Adesi et al. [Barone-Adesi, G., Giannopoulos, K., Vosper, L., 1999. VaR without correlations for portfolios of derivative securities. Journal of Futures Markets 19 (5), 583-602]. The results suggest that the semi-parametric GARCH model generates VaR forecasts that are superior to the VaR forecasts from the ARMA with historical simulation. This is due to the fact that GARCH captures volatility clustering. Our findings suggest that Cabedo and Moya's conclusion is mainly driven by the normal distributional assumption imposed on the future risk structure in the GARCH model. (author)

Antisense long noncoding RNAs regulate var gene activation in the malaria parasite Plasmodium falciparum.

Science.gov (United States)

Amit-Avraham, Inbar; Pozner, Guy; Eshar, Shiri; Fastman, Yair; Kolevzon, Netanel; Yavin, Eylon; Dzikowski, Ron

2015-03-03

The virulence of Plasmodium falciparum, the causative agent of the deadliest form of human malaria, is attributed to its ability to evade human immunity through antigenic variation. These parasites alternate between expression of variable antigens, encoded by members of a multicopy gene family named var. Immune evasion through antigenic variation depends on tight regulation of var gene expression, ensuring that only a single var gene is expressed at a time while the rest of the family is maintained transcriptionally silent. Understanding how a single gene is chosen for activation is critical for understanding mutually exclusive expression but remains a mystery. Here, we show that antisense long noncoding RNAs (lncRNAs) initiating from var introns are associated with the single active var gene at the time in the cell cycle when the single var upstream promoter is active. We demonstrate that these antisense transcripts are incorporated into chromatin, and that expression of these antisense lncRNAs in trans triggers activation of a silent var gene in a sequence- and dose-dependent manner. On the other hand, interference with these lncRNAs using complement peptide nucleic acid molecules down-regulated the active var gene, erased the epigenetic memory, and induced expression switching. Altogether, our data provide evidence that these antisense lncRNAs play a key role in regulating var gene activation and mutually exclusive expression.

Somatic embryogenesis in Agave sisalana Perrine: induction, characterization and anatomical regeneration

Directory of Open Access Journals (Sweden)

Fernando dos Santos Carneiro

2014-09-01

Full Text Available Sisal (Agave sisalana Perrine is used for the extraction of fibers present in their leaves, being considered the main hard fiber produced in the world. However, a decline has been observed for this crop, due to a disease caused by the soil fungus Aspergillus niger. Biotechnology, particularly tissue culture techniques, represents a viable alternative for propagating this species. Among these techniques, the somatic embryogenesis can be pointed out. Thus, this study aimed to characterize the in vitro morphogenesis, during somatic embryogenesis, in A. sisalana Perrine. In all experiments, bulblets were used as explants and also ½ MS medium plus sucrose (30.0 g L-1, solidified with agar (7.0 g L-1 supplemented with different concentrations of auxin and cytokinin. The explants formed callus with compact and semi-compact aspects, pointing out the embryogenic cells converted into somatic embryos with the use of 2,4-D and BAP. The anatomic analyzes showed embryos in globular and torpedo stages and no connection with the mother callus.

Mosquito Passage Dramatically Changes var Gene Expression in Controlled Human Plasmodium falciparum Infections.

Science.gov (United States)

Bachmann, Anna; Petter, Michaela; Krumkamp, Ralf; Esen, Meral; Held, Jana; Scholz, Judith A M; Li, Tao; Sim, B Kim Lee; Hoffman, Stephen L; Kremsner, Peter G; Mordmüller, Benjamin; Duffy, Michael F; Tannich, Egbert

2016-04-01

Virulence of the most deadly malaria parasite Plasmodium falciparum is linked to the variant surface antigen PfEMP1, which is encoded by about 60 var genes per parasite genome. Although the expression of particular variants has been associated with different clinical outcomes, little is known about var gene expression at the onset of infection. By analyzing controlled human malaria infections via quantitative real-time PCR, we show that parasite populations from 18 volunteers expressed virtually identical transcript patterns that were dominated by the subtelomeric var gene group B and, to a lesser extent, group A. Furthermore, major changes in composition and frequency of var gene transcripts were detected between the parental parasite culture that was used to infect mosquitoes and Plasmodia recovered from infected volunteers, suggesting that P. falciparum resets its var gene expression during mosquito passage and starts with the broad expression of a specific subset of var genes when entering the human blood phase.

Genome-wide analysis of SU(VAR)3-9 distribution in chromosomes of Drosophila melanogaster.

Science.gov (United States)

Maksimov, Daniil A; Laktionov, Petr P; Posukh, Olga V; Belyakin, Stepan N; Koryakov, Dmitry E

2018-03-01

Histone modifications represent one of the key factors contributing to proper genome regulation. One of histone modifications involved in gene silencing is methylation of H3K9 residue. Present in the chromosomes across different eukaryotes, this epigenetic mark is controlled by SU(VAR)3-9 and its orthologs. Despite SU(VAR)3-9 was discovered over two decades ago, little is known about the details of its chromosomal distribution pattern. To fill in this gap, we used DamID-seq approach and obtained high-resolution genome-wide profiles for SU(VAR)3-9 in two somatic (salivary glands and brain ganglia) and two germline (ovarian nurse cells and testes) tissues of Drosophila melanogaster. Analysis of tissue and developmental expression of SU(VAR)3-9-bound genes indicates that in the somatic tissues tested, as well as in the ovarian nurse cells, SU(VAR)3-9 tends to associate with transcriptionally silent genes. In contrast, in the testes, SU(VAR)3-9 shows preferential association with testis-specific genes, and its binding appears dynamic during spermatogenesis. In somatic cells, the mere presence/absence of SU(VAR)3-9 binding correlates with lower/higher expression. No such correlation is found in the male germline. Interestingly, transcription units in piRNA clusters (particularly flanks thereof) are frequently targeted by SU(VAR)3-9, and Su(var)3-9 mutation affects the expression of select piRNA species. Our analyses suggest a context-dependent role of SU(VAR)3-9. In euchromatin, SU(VAR)3-9 may serve to fine-tune the expression of individual genes, whereas in heterochromatin, chromosome 4, and piRNA clusters, it may act more broadly over large chromatin domains.

Twenty novel polymorphic microsatellite primers in the critically endangered Melastoma tetramerum var. tetramerum (Melastomataceae).

Science.gov (United States)

Narita, Ayu; Izuno, Ayako; Komaki, Yoshiteru; Tanaka, Takefumi; Murata, Jin; Isagi, Yuji

2016-09-01

Microsatellite markers were identified for Melastoma tetramerum var. tetramerum (Melastomataceae), a critically endangered shrub endemic to the Bonin Islands, to reveal genetic characteristics in wild and restored populations. Using next-generation sequencing, 27 microsatellite markers were identified. Twenty of these markers were polymorphic in M. tetramerum var. tetramerum, with two to nine alleles per locus and expected heterozygosity ranging from 0.10 to 0.71. Among the 20 polymorphic markers, 15 were applicable to other closely related taxa, namely M. tetramerum var. pentapetalum, M. candidum var. candidum, and M. candidum var. alessandrense. These markers can be potentially useful to investigate the genetic diversity, population genetic structure, and reproductive ecology of M. tetramerum var. tetramerum as well as of the three related taxa to provide appropriate genetic information for conservation.

Semi-nonparametric VaR forecasts for hedge funds during the recent crisis

Science.gov (United States)

Del Brio, Esther B.; Mora-Valencia, Andrés; Perote, Javier

2014-05-01

The need to provide accurate value-at-risk (VaR) forecasting measures has triggered an important literature in econophysics. Although these accurate VaR models and methodologies are particularly demanded for hedge fund managers, there exist few articles specifically devoted to implement new techniques in hedge fund returns VaR forecasting. This article advances in these issues by comparing the performance of risk measures based on parametric distributions (the normal, Student’s t and skewed-t), semi-nonparametric (SNP) methodologies based on Gram-Charlier (GC) series and the extreme value theory (EVT) approach. Our results show that normal-, Student’s t- and Skewed t- based methodologies fail to forecast hedge fund VaR, whilst SNP and EVT approaches accurately success on it. We extend these results to the multivariate framework by providing an explicit formula for the GC copula and its density that encompasses the Gaussian copula and accounts for non-linear dependences. We show that the VaR obtained by the meta GC accurately captures portfolio risk and outperforms regulatory VaR estimates obtained through the meta Gaussian and Student’s t distributions.

Comparative anatomy of the leaves of Piper lepturum(Kunth) C.DC. var. lepturum and Piper lepturum var. angustifolium (C.DC.) Yunck.

OpenAIRE

Machado, Nelson Santana de Oliveira; Pereira, Flaviane Gomes; Santos, Paulo Roberto Dias dos; Costa, Cecília Gonçalves; Guimarães, Elsie Franklin

2015-01-01

This study showed anatomical differences related to Piper lepturumvar. lepturum and P. lepturum var. angustifolium species, sometimes considered varieties and in other cases synonyms. For histological analysis, fully expanded leaves were collected and for analysis by scanning electron microscope (SEM), fragments from the midrib were fixed on both leaf surfaces. The two species revealed differences in plant anatomy and it was observed that the stem of P. lepturum var. lepturum showed persisten...

Resistance to Southern Root-knot Nematode (Meloidogyne incognita) in Wild Watermelon (Citrullus lanatus var. citroides).

Science.gov (United States)

Thies, Judy A; Ariss, Jennifer J; Kousik, Chandrasekar S; Hassell, Richard L; Levi, Amnon

2016-03-01

Southern root-knot nematode (RKN, Meloidogyne incognita) is a serious pest of cultivated watermelon (Citrullus lanatus var. lanatus) in southern regions of the United States and no resistance is known to exist in commercial watermelon cultivars. Wild watermelon relatives (Citrullus lanatus var. citroides) have been shown in greenhouse studies to possess varying degrees of resistance to RKN species. Experiments were conducted over 2 yr to assess resistance of southern RKN in C. lanatus var. citroides accessions from the U.S. Watermelon Plant Introduction Collection in an artificially infested field site at the U.S. Vegetable Laboratory in Charleston, SC. In the first study (2006), 19 accessions of C. lanatus var. citroides were compared with reference entries of Citrullus colocynthis and C. lanatus var. lanatus. Of the wild watermelon accessions, two entries exhibited significantly less galling than all other entries. Five of the best performing C. lanatus var. citroides accessions were evaluated with and without nematicide at the same field site in 2007. Citrullus lanatus var. citroides accessions performed better than C. lanatus var. lanatus and C. colocynthis. Overall, most entries of C. lanatus var. citroides performed similarly with and without nematicide treatment in regard to root galling, visible egg masses, vine vigor, and root mass. In both years of field evaluations, most C. lanatus var. citroides accessions showed lesser degrees of nematode reproduction and higher vigor and root mass than C. colocynthis and C. lanatus var. lanatus. The results of these two field evaluations suggest that wild watermelon populations may be useful sources of resistance to southern RKN.

ESTIMATING RISK ON THE CAPITAL MARKET WITH VaR METHOD

Directory of Open Access Journals (Sweden)

Sinisa Bogdan

2015-06-01

Full Text Available The two basic questions that every investor tries to answer before investment are questions about predicting return and risk. Risk and return are generally considered two positively correlated sizes, during the growth of risk it is expected increase of return to compensate the higher risk. The quantification of risk in the capital market represents the current topic since occurrence of securities. Together with estimated future returns it represents starting point of any investment. In this study it is described the history of the emergence of VaR methods, usefulness in assessing the risks of financial assets. Three main Value at Risk (VaR methodologies are decribed and explained in detail: historical method, parametric method and Monte Carlo method. After the theoretical review of VaR methods it is estimated risk of liquid stocks and portfolio from the Croatian capital market with historical and parametric VaR method, after which the results were compared and explained.

Comparison of historically simulated VaR: Evidence from oil prices

Energy Technology Data Exchange (ETDEWEB)

Costello, Alexandra [Seminole Canada Energy, Calgary, AB (Canada); Asem, Ebenezer; Gardner, Eldon [Faculty of Management, University of Lethbridge, Lethbridge, AB (Canada)

2008-09-15

Cabedo and Moya [Cabedo, J.D., Moya, I., 2003. Estimating oil price 'Value at Risk' using the historical simulation approach. Energy Economics 25, 239-253] find that ARMA with historical simulation delivers VaR forecasts that are superior to those from GARCH. We compare the ARMA with historical simulation to the semi-parametric GARCH model proposed by Barone-Adesi et al. [Barone-Adesi, G., Giannopoulos, K., Vosper, L., 1999. VaR without correlations for portfolios of derivative securities. Journal of Futures Markets 19 (5), 583-602]. The results suggest that the semi-parametric GARCH model generates VaR forecasts that are superior to the VaR forecasts from the ARMA with historical simulation. This is due to the fact that GARCH captures volatility clustering. Our findings suggest that Cabedo and Moya's conclusion is mainly driven by the normal distributional assumption imposed on the future risk structure in the GARCH model. (author)

PREVALENCIA DE Strongyloides stercoralis Y OTROS PARÁSITOS INTESTINALES EN INDIGENTES ALCOHÓLICOS DE CIUDAD BOLÍVAR, ESTADO BOLÍVAR, VENEZUELA | PREVALENCE OF Strongyloides stercoralis AND OTHER INTESTINAL PARASITES IN ALCOHOLIC HOMELESS FROM CIUDAD BOLÍVAR, BOLÍVAR STATE, VENEZUELA

Directory of Open Access Journals (Sweden)

Rodolfo Devera

2015-11-01

Full Text Available Between may and july 2010 a study was performed in order to determine the prevalence of Strongyloides stercoralis and other intestinal parasites in alcoholic homeless who attend two Alcoholics Anonymous Centers in Ciudad Bolívar, Bolívar State, Venezuela. Eighty stool samples were collected, which were analyzed using the techniques of direct examination, Kato, micro-Baermann, Rugai and agar plate culture. An estimate of 61.3% of the evaluated population was parasitized. The intestinal parasite most prevalent was the chromist Blastocystis (33.8%. Among the protozoan, the most common was Endolimax nana (21.3% and among the helminths it was Strongyloides stercoralis (12.5%.

EFFECTS OF MONETARY POLICY IN ROMANIA - A VAR APPROACH

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Iulian Popescu

2012-10-01

Full Text Available Understanding how monetary policy decisions affect inflation and other economic variables is particularly important. In this paper we consider the implications of monetary policy under the inflation targeting regime in Romania, based on an autoregressive vector method including recursive VAR and structural VAR (SVAR. Therefore, we focus on assessing the extent and persistence of monetary policy effects on gross domestic product (GDP, price level, extended monetary aggregate (M3 and exchange rate. The main results of VAR analysis reflect a negative response of consumer price index (CPI, GDP and M3 and positive nominal exchange rate behaviour to a monetary policy shock, and also a limited impact of a short-term interest rate shock in explaining the consumer prices, production and exchange rate fluctuations.

Da abort ikke var en sag for kvinden

DEFF Research Database (Denmark)

Schultz, Annette Østergaard

2013-01-01

Case fra tiden før 1973, hvor der ikke var fri abort i Danmark. Sagen er fundet i Mødrehjælpens arkiv og giver som andre sager indblik i kvindens situation. Led i serien: Nyt i arkivet.......Case fra tiden før 1973, hvor der ikke var fri abort i Danmark. Sagen er fundet i Mødrehjælpens arkiv og giver som andre sager indblik i kvindens situation. Led i serien: Nyt i arkivet....

Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta.

Science.gov (United States)

Quiroz-Castañeda, Rosa E; Martínez-Anaya, Claudia; Cuervo-Soto, Laura I; Segovia, Lorenzo; Folch-Mallol, Jorge L

2011-02-11

Expansins and expansin-like proteins loosen cellulose microfibrils, possibly through the rupture of intramolecular hydrogen bonds. Together with the use of lignocellulolytic enzymes, these proteins are potential molecular tools to treat plant biomass to improve saccharification yields. Here we describe a new type of expansin-related fungal protein that we have called loosenin. Its corresponding gene, loos1, from the basidiomycete Bjerkandera adusta, was cloned and heterologously expressed in Saccharomyces cerevisiae. LOOS1 is distantly related to plant expansins through the shared presence of a DPBB domain, however domain II found in plant expansins is absent. LOOS1 binds tightly to cellulose and chitin, and we demonstrate that cotton fibers become susceptible to the action of a commercial cellulase following treatment with LOOS1. Natural fibers of Agave tequilana also become susceptible to hydrolysis by cellulases after loosenin treatment. LOOS1 is a new type of protein with disrupting activity on cellulose. LOOS1 binds polysaccharides, and given its enhancing properties on the action of hydrolytic enzymes, LOOS1 represents a potential additive in the production of fermentable sugars from lignocellulose.

Optimizing expression of the pregnancy malaria vaccine candidate, VAR2CSA in Pichia pastoris.

Science.gov (United States)

Avril, Marion; Hathaway, Marianne J; Cartwright, Megan M; Gose, Severin O; Narum, David L; Smith, Joseph D

2009-06-29

VAR2CSA is the main candidate for a vaccine against pregnancy-associated malaria, but vaccine development is complicated by the large size and complex disulfide bonding pattern of the protein. Recent X-ray crystallographic information suggests that domain boundaries of VAR2CSA Duffy binding-like (DBL) domains may be larger than previously predicted and include two additional cysteine residues. This study investigated whether longer constructs would improve VAR2CSA recombinant protein secretion from Pichia pastoris and if domain boundaries were applicable across different VAR2CSA alleles. VAR2CSA sequences were bioinformatically analysed to identify the predicted C11 and C12 cysteine residues at the C-termini of DBL domains and revised N- and C-termimal domain boundaries were predicted in VAR2CSA. Multiple construct boundaries were systematically evaluated for protein secretion in P. pastoris and secreted proteins were tested as immunogens. From a total of 42 different VAR2CSA constructs, 15 proteins (36%) were secreted. Longer construct boundaries, including the predicted C11 and C12 cysteine residues, generally improved expression of poorly or non-secreted domains and permitted expression of all six VAR2CSA DBL domains. However, protein secretion was still highly empiric and affected by subtle differences in domain boundaries and allelic variation between VAR2CSA sequences. Eleven of the secreted proteins were used to immunize rabbits. Antibodies reacted with CSA-binding infected erythrocytes, indicating that P. pastoris recombinant proteins possessed native protein epitopes. These findings strengthen emerging data for a revision of DBL domain boundaries in var-encoded proteins and may facilitate pregnancy malaria vaccine development.

Optimizing expression of the pregnancy malaria vaccine candidate, VAR2CSA in Pichia pastoris

Directory of Open Access Journals (Sweden)

Narum David L

2009-06-01

Full Text Available Abstract Background VAR2CSA is the main candidate for a vaccine against pregnancy-associated malaria, but vaccine development is complicated by the large size and complex disulfide bonding pattern of the protein. Recent X-ray crystallographic information suggests that domain boundaries of VAR2CSA Duffy binding-like (DBL domains may be larger than previously predicted and include two additional cysteine residues. This study investigated whether longer constructs would improve VAR2CSA recombinant protein secretion from Pichia pastoris and if domain boundaries were applicable across different VAR2CSA alleles. Methods VAR2CSA sequences were bioinformatically analysed to identify the predicted C11 and C12 cysteine residues at the C-termini of DBL domains and revised N- and C-termimal domain boundaries were predicted in VAR2CSA. Multiple construct boundaries were systematically evaluated for protein secretion in P. pastoris and secreted proteins were tested as immunogens. Results From a total of 42 different VAR2CSA constructs, 15 proteins (36% were secreted. Longer construct boundaries, including the predicted C11 and C12 cysteine residues, generally improved expression of poorly or non-secreted domains and permitted expression of all six VAR2CSA DBL domains. However, protein secretion was still highly empiric and affected by subtle differences in domain boundaries and allelic variation between VAR2CSA sequences. Eleven of the secreted proteins were used to immunize rabbits. Antibodies reacted with CSA-binding infected erythrocytes, indicating that P. pastoris recombinant proteins possessed native protein epitopes. Conclusion These findings strengthen emerging data for a revision of DBL domain boundaries in var-encoded proteins and may facilitate pregnancy malaria vaccine development.

Waarnemingen aan Equisetum arvense L. var. serotinum F.W. Meyer

NARCIS (Netherlands)

Hoek, van L.

1978-01-01

Observations during six successive years in a cultivated clone of Equisetum arvense L. var. serotinum F. W. Meyer made it possible to study various types of fertile, sterile, and homophyadic stems developing in this clone. As E. arvense var. varium Milde, E. arvense f. sanguineum Luerss., and E.

Een nieuwe naam voor Arenaria serpyllifolia L. var. macrocarpa Lloyd

NARCIS (Netherlands)

Gutermann, W.; Mennema, J.

1983-01-01

The name Arenaria serpyllifoiia L. var. macrocarpa Lloyd is illegitimate, because of the existence of the earlier non-synonymous A. serpyllifolia0 macrocarpa Godron. As on the level of variety no other name is available, we call the taxon A renaria serpylli/olia L. var. Iloydn (Jord.) Gutermann et

Exact eigenstates and open-quotes trivialityclose quotes of λ(var-phi *var-phi)2 theory in the Feshbach-Villars formulation

International Nuclear Information System (INIS)

Darewych, J.W.

1997-01-01

The complex scalar (Klein-Gordon) quantum field theory (QFT) with a λ(var-phi * var-phi) 2 interaction is considered in the Feshbach-Villars formulation. It is shown that exact few-particle eigenstates of the QFT Hamiltonian can be obtained. The resulting relativistic few-body equations correspond to Klein-Gordon particles interacting via delta-function, or open-quotes contact,close quotes potentials. Momentum-space solutions of the two-body equation yield a open-quotes trivialclose quotes unity S matrix. copyright 1997 The American Physical Society

Phyllactinia mali and Podosphaera tridactyla var. tridactyla – new hosts of Ampelomyces quisqualis

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Beata Czerniawska

2014-08-01

Full Text Available In 2002, the occurrence of fungi of the order Erysiphales on plants of the Słowiański Park located in Goorzów Wielkopolski was investigated. Plant samples were collected once a month, from August to November. The samples examined were above ground plant parts colonized by powdery mildew fungi. A total of 78 samples were collected. Apart from 14 species of the order Erysiphales, Ampelomyces quisqualis parasitizing on Erysiphe cichoracearum var. cichoracearum, Phyllactinia mali and Podosphaera tridactyl var. tridactyla was found. Ampelomyces quisqualis affected hyphae, oidia, and young cleistothecia of P. mali. In contrast, in E. cichoracearum var. cichoracearum, Po. tridactyle var. tridactyla, this hyperparasite colonized only hyphae and oidia. This paper for the first trime informs of A. quisqualis parasitizing on P. mali and Po. tridactyla var. tridactyla.

"Var Teatre"--A Pioneer Turns 40.

Science.gov (United States)

Jones, Pamela L.

1984-01-01

Describes the Stockholm Municipal Youth and Children's theatre ("Var Teatre"), an institution of 14 theatres and attendant professional staff devoted exclusively to drama activities for children and teenagers. (PD)

Somatic Embryogenesis in Olive (Olea europaea L. subsp. europaea var. sativa and var. sylvestris).

Science.gov (United States)

Rugini, Eddo; Silvestri, Cristian

2016-01-01

Protocols for olive somatic embryogenesis from zygotic embryos and mature tissues have been described for both Olea europaea sub. europaea var. sativa and var. sylvestris. Immature zygotic embryos (no more than 75 days old), used after fruit collection or stored at 12-14 °C for 2-3 months, are the best responsive explants and very slightly genotype dependent, and one single protocol can be effective for a wide range of genotypes. On the contrary, protocols for mature zygotic embryos and for mature tissue of cultivars are often genotype specific, so that they may require many adjustments according to genotypes. The use of thidiazuron and cefotaxime seems to be an important trigger for induction phase particularly for tissues derived from cultivars. Up to now, however, the application of this technique for large-scale propagation is hampered also by the low rate of embryo germination; it proves nonetheless very useful for genetic improvement.

VAR Portfolio Optimal: Perbandingan Antara Metode Markowitz dan Mean Absolute Deviation

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R. Agus Sartono

2009-05-01

Full Text Available Portfolio selection method which have been introduced by Harry Markowitz (1952 used variance or deviation standard as a measure of risk. Kanno and Yamazaki (1991 introduced another method and used mean absolute deviation as a measure of risk instead of variance. The Value-at Risk (VaR is a relatively new method to capitalized risk that been used by financial institutions. The aim of this research is compare between mean variance and mean absolute deviation of two portfolios. Next, we attempt to assess the VaR of two portfolios using delta normal method and historical simulation. We use the secondary data from the Jakarta Stock Exchange – LQ45 during 2003. We find that there is a weak-positive correlation between deviation standard and return in both portfolios. The VaR nolmal delta based on mean absolute deviation method eventually is higher than the VaR normal delta based on mean variance method. However, based on the historical simulation the VaR of two methods is statistically insignificant. Thus, the deviation standard is sufficient measures of portfolio risk.Keywords: optimalisasi portofolio, mean-variance, mean-absolute deviation, value-at-risk, metode delta normal, metode simulasi historis

Efficient transformation and expression of gfp gene in Valsa mali var. mali.

Science.gov (United States)

Chen, Liang; Sun, Gengwu; Wu, Shujing; Liu, Huixiang; Wang, Hongkai

2015-01-01

Valsa mali var. mali, the causal agent of valsa canker of apple, causes great loss of apple production in apple producing regions. The pathogenic mechanism of the pathogen has not been studied extensively, thus a suitable gene marker for pathogenic invasion analysis and a random insertion of T-DNA for mutants are desirable. In this paper, we reported the construction of a binary vector pKO1-HPH containing a positive selective gene hygromycin phosphotransferase (hph), a reporter gene gfp conferring green fluorescent protein, and an efficient protocol for V. mali var. mali transformation mediated by Agrobacterium tumefaciens. A transformation efficiency up to about 75 transformants per 10(5) conidia was achieved when co-cultivation of V. mali var. mali and A. tumefaciens for 48 h in A. tumefaciens inductive medium agar plates. The insertions of hph gene and gfp gene into V. mali var. mali genome verified by polymerase chain reaction and southern blot analysis showed that 10 randomly-selected transformants exhibited a single, unique hybridization pattern. This is the first report of A. tumefaciens-mediated transformation of V. mali var mali carrying a 'reporter' gfp gene that stably and efficiently expressed in the transformed V. mali var. mali species.

Effect of an admixture from Agave americana on the physical and mechanical properties of plaster

Directory of Open Access Journals (Sweden)

Ochoa, J. C.

2013-03-01

Full Text Available Physical and mechanical properties of a plaster paste added with an organic admixture, of the leaves of Agave americana, were studied. Plastic consistency behavior was evaluated and the water/gypsum(w/g ratio was determined for each dosage of the admixture. Admixtur eeffect on setting was evaluated too. The chemical transformation of the hemihydrated form to gypsum (dihydrated form was studied using a novel technique based on a moisture analyzer by halogen light. Flexural and compressive strengths were measured. The results show that ,for the same consistency, accordingly mechanical strengths were improved too. The setting times were increased which would enhance the application time of plaster and would reduce plastic shrinkage, common problems in this type of material. The changes in these physical properties not substantially affect the final mechanical strengths.

Se estudiaron algunas propiedades físicas y mecánicas de pastas de yeso de construcción adicionadas con un aditivo de origen orgánico, producto de las hojas de la planta Agave americana. Se evaluó el comportamiento plástico de la pasta mediante ensayos de consistencia y se determinó, para cada dosificación, su relación agua/ yeso (a/y. Se evaluó la incidencia del aditivo en los tiempos de fraguado. La transformación química del hemihidrato a yeso dihidrato se estudió mediante una novedosa técnica basada en un analizador de humedad por luz halógena. Se midieron las resistencias mecánicas a flexo-tracción y a compresión. Los resultados del estudio muestran que, para una misma consistencia, se mejoran las resistencias mecánicas. Los tiempos de fraguado de la pasta se aumentaron lo que ayudaría mejorar los tiempos de aplicación del yeso y a disminuir las retracciones plásticas. Las modificaciones de estas propiedades físicas no afectan considerablemente las resistencias mecánicas finales.

Dynamics of anti-VAR2CSA immunoglobulin G response in a cohort of senegalese pregnant women

DEFF Research Database (Denmark)

Tuikue Ndam, N G; Salanti, A; Le-Hesran, J-Y

2006-01-01

demonstrated that a single P. falciparum infection was able to trigger a VAR2CSA-specific antibody response. Among women with infected placentas, women with high anti-VAR2CSA IgG levels at enrollment were more likely to present with a past infection than with an acute/chronic infection. CONCLUSIONS: Anti-VAR2...... (VSAPAM). Several studies have shown that 1 var gene, var2csa, is transcribed at high levels and expressed in CSA-binding Plasmodium falciparum parasites. METHODS: Plasma levels of anti-VAR2CSA immunoglobulin G (IgG) in Senegalese women were measured during pregnancy by enzyme-linked immunosorbent assay......, using 3 recombinant proteins representing 3 domains of the var2csa gene product. RESULTS: The 3 recombinant proteins were specifically recognized by plasma from pregnant women but not by control plasma. A parity-dependent recognition pattern was observed with 2 of the 3 VAR2CSA antigens. A kinetic study...

Murine Model for Preclinical Studies of Var2CSA-Mediated Pathology Associated with Malaria in Pregnancy

Science.gov (United States)

Dechavanne, Sebastien; Sousa, Patrícia M.; Barateiro, André; Cunha, Sónia F.; Nunes-Silva, Sofia; Lima, Flávia A.; Murillo, Oscar; Marinho, Claudio R. F.; Gangnard, Stephane; Srivastava, Anand; Braks, Joanna A.; Janse, Chris J.; Gamain, Benoit; Penha-Gonçalves, Carlos

2016-01-01

Plasmodium falciparum infection during pregnancy leads to abortions, stillbirth, low birth weight, and maternal mortality. Infected erythrocytes (IEs) accumulate in the placenta by adhering to chondroitin sulfate A (CSA) via var2CSA protein exposed on the P. falciparum IE membrane. Plasmodium berghei IE infection in pregnant BALB/c mice is a model for severe placental malaria (PM). Here, we describe a transgenic P. berghei parasite expressing the full-length var2CSA extracellular region (domains DBL1X to DBL6ε) fused to a P. berghei exported protein (EMAP1) and characterize a var2CSA-based mouse model of PM. BALB/c mice were infected at midgestation with different doses of P. berghei-var2CSA (P. berghei-VAR) or P. berghei wild-type IEs. Infection with 104 P. berghei-VAR IEs induced a higher incidence of stillbirth and lower fetal weight than P. berghei. At doses of 105 and 106 IEs, P. berghei-VAR-infected mice showed increased maternal mortality during pregnancy and fetal loss, respectively. Parasite loads in infected placentas were similar between parasite lines despite differences in maternal outcomes. Fetal weight loss normalized for parasitemia was higher in P. berghei-VAR-infected mice than in P. berghei-infected mice. In vitro assays showed that higher numbers of P. berghei-VAR IEs than P. berghei IEs adhered to placental tissue. Immunization of mice with P. berghei-VAR elicited IgG antibodies reactive to DBL1-6 recombinant protein, indicating that the topology of immunogenic epitopes is maintained between DBL1-6–EMAP1 on P. berghei-VAR and recombinant DBL1-6 (recDBL1-6). Our data suggested that impairments in pregnancy caused by P. berghei-VAR infection were attributable to var2CSA expression. This model provides a tool for preclinical evaluation of protection against PM induced by approaches that target var2CSA. PMID:27045035

Fast Responding Voltage Regulator and Dynamic VAR Compensator

Energy Technology Data Exchange (ETDEWEB)

Divan, Deepak [Varentec, Incorporated, San Jose, CA (United States); Moghe, Rohit [Varentec, Incorporated, San Jose, CA (United States); Tholomier, Damien [Varentec, Incorporated, San Jose, CA (United States)

2014-12-31

The objectives of this project were to develop a dynamic VAR compensator (DVC) for voltage regulation through VAR support to demonstrate the ability to achieve greater levels of voltage control on electricity distribution networks, and faster response compared to existing grid technology. The goal of the project was to develop a prototype Fast Dynamic VAR Compensator (Fast DVC) hardware device, and this was achieved. In addition to developing the dynamic VAR compensator device, Varentec in partnership with researchers at North Carolina State University (NCSU) successfully met the objectives to model the potential positive impact of such DVCs on representative power networks. This modeling activity validated the ability of distributed dynamic VAR compensators to provide fast voltage regulation and reactive power control required to respond to grid disturbances under high penetration of fluctuating and intermittent distributed energy resources (DERs) through extensive simulation studies. Specifically the following tasks were set to be accomplished: 1) Development of dynamic VAR compensator to support dynamic voltage variations on the grid through VAR control 2) Extensive testing of the DVC in the lab environment 3) Present the operational DVC device to the DOE at Varentec’s lab 4) Formulation of a detailed specification sheet, unit assembly document, test setup document, unit bring-up plan, and test plan 5) Extensive simulations of the DVC in a system with high PV penetration. Understanding the operation with many DVC on a single distribution system 6) Creation and submittal of quarterly and final reports conveying the design documents, unit performance data, modeling simulation charts and diagrams, and summary explanations of the satisfaction of program goals. This report details the various efforts that led to the development of the Fast DVC as well as the modeling & simulation results. The report begins with the introduction in Section II which outlines the

Physiological integration of parents and ramets of Agave deserti: Carbon relations during vegetative and sexually reproductive growth

International Nuclear Information System (INIS)

Tissue, D.T.

1989-01-01

Agave deserti is a semelparous perennial occurring in the northwestern Sonoran Desert that flowers after 50-55 years, but propagates primarily vegetatively by ramets. Shading ramets in the field to light compensation for two years did not decrease their relative growth rate compared with unshaded ramets. However, parents experienced a 30% decrease in total nonstructural carbohydrate (TNC) level, indicating that carbohydrates were translocated from parents to ramets. Parents were also shaded in the field for two years and about 10% of the growth of the shaded parents was attributed to TNC received from their attached, unshaded ramets indicating bidirectional translocation of carbohydrates between parents and ramets. The amount of carbon imported by a ramet from its parent, measured using 14 CO 2 techniques, was related to its photosynthetically active radiation environment, shaded ramets received 2.1 times more carbon than unshaded ramets, and was inversely related to the mass of the ramet, small ramets received up to 4.5 times more carbon than large ramets. The physiological integration of parents and ramets allows ramets to draw upon the reserves of the parent, thereby facilitating ramet growth and establishment in a resource-limited environment. Rosettes of Agave deserti must attain a minimum size (> 1,000 g dry mass) to initiate flowering, unless they are connected to a large flowering parent. Ramets that flower precociously can not complete formation of their inflorescence unless partially supported by carbon supplied by their attached parent. TNC reserves of the parent provided 70% of the carbon required to produce its own inflorescence, typically 4 m tall and 1.5 kg in dry mass, and CO 2 uptake by the leaves and the inflorescence provided the remaining 30%

Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment

Directory of Open Access Journals (Sweden)

Marcelo C. Appel-da-Silva

2017-12-01

Full Text Available Probiotics are commonly prescribed as an adjuvant in the treatment of antibiotic-associated diarrhea caused by Clostridium difficile. We report the case of an immunocompromised 73-year-old patient on chemotherapy who developed Saccharomyces cerevisiae var. boulardii fungemia in a central venous catheter during treatment of antibiotic-associated pseudomembranous colitis with the probiotic Saccharomyces cerevisiae var. boulardii. Fungemia was resolved after interruption of probiotic administration without the need to replace the central venous line. Keywords: Saccharomyces, Probiotics, Fungemia, Critical illness, Clostridium difficile

Characterization of leaf area of Agave fourcroydes Lem. plants obtained from asexual propagation

Directory of Open Access Journals (Sweden)

Maryla Sosa del Castillo

2014-01-01

Full Text Available The henequen (Agave fourcroydes Lem. is a crop of great economic importance. This study was aimed to characterize the leaf surface of henequen plants variety `Sac Ki' obtained by asexual propagation methods. In vitro plants, shoots of bulbils of in vitro plants, shoots of rhizomes of in vitro plants, shoots of bulbils of field plants and shoots of field rhizomes were used. At 7 and 15 months after planting in the nursery, the epidermis was characterized through the stomatal index and stomatal density. Moreover, the conductor vessels and fiber bundles in leaf mesophyll, were characterized. It was found that the leaf surface of henequen plants variety `Sac Ki' obtained by different methods of asexual propagation showed similar anatomical structures. However, it was observed that in vitro plants were different from the rest in terms of stomatal index and stomatal density in both time points. It was suggesting a accommodate response to environmental conditions. Key words: stomatic density, stomatic index, in vitro plants

Influence of Hybridizing Flax and Hemp-Agave Fibers with Glass Fiber as Reinforcement in a Polyurethane Composite

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Pankaj Pandey

2016-05-01

Full Text Available In this study, six combinations of flax, hemp, and glass fiber were investigated for a hybrid reinforcement system in a polyurethane (PU composite. The natural fibers were combined with glass fibers in a PU composite in order to achieve a better mechanical reinforcement in the composite material. The effect of fiber hybridization in PU composites was evaluated through physical and mechanical properties such as water absorption (WA, specific gravity (SG, coefficient of linear thermal expansion (CLTE, flexural and compression properties, and hardness. The mechanical properties of hybridized samples showed mixed trends compared to the unhybridized samples, but hybridization with glass fiber reduced water absorption by 37% and 43% for flax and hemp-agave PU composites respectively.

Computing Conditional VaR using Time-varying CopulasComputing Conditional VaR using Time-varying Copulas

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Beatriz Vaz de Melo Mendes

2005-12-01

Full Text Available It is now widespread the use of Value-at-Risk (VaR as a canonical measure at risk. Most accurate VaR measures make use of some volatility model such as GARCH-type models. However, the pattern of volatility dynamic of a portfolio follows from the (univariate behavior of the risk assets, as well as from the type and strength of the associations among them. Moreover, the dependence structure among the components may change conditionally t past observations. Some papers have attempted to model this characteristic by assuming a multivariate GARCH model, or by considering the conditional correlation coefficient, or by incorporating some possibility for switches in regimes. In this paper we address this problem using time-varying copulas. Our modeling strategy allows for the margins to follow some FIGARCH type model while the copula dependence structure changes over time.

MODEL NON LINIER GARCH (NGARCH UNTUK MENGESTIMASI NILAI VALUE at RISK (VaR PADA IHSG

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I KOMANG TRY BAYU MAHENDRA

2015-06-01

Full Text Available In investment, risk measurement is important. One of risk measure is Value at Risk (VaR. There are many methods that can be used to estimate risk based on VaR framework. One of them Non Linier GARCH (NGARCH model. In this research, determination of VaR used NGARCH model. NGARCH model allowed for asymetric behaviour in the volatility such that “good news” or positive return and “bad news” or negative return. Based on calculations of VaR, the higher of the confidence level and the longer the investment period, the risk was greater. Determination of VaR using NGARCH model was less than GARCH model.

[Gene cloning and bioinformatics analysis of SABATH methyltransferase in Lonicera japonica var. chinensis].

Science.gov (United States)

Yu, Xiao-Dan; Jiang, Chao; Huang, Lu-Qi; Qin, Shuang-Shuang; Zeng, Xiang-Mei; Chen, Ping; Yuan, Yuan

2013-08-01

To clone SABATH methyltransferase (rLjSABATHMT) gene in Lonicera japonica var. chinensis, and compare the gene expression and intron sequence of SABATH methyltransferase orthologous in L. japonica with L. japonica var. chinensis. It provide a basis for gene regulate the formation of L. japonica floral scents. The cDNA and genome sequences of LjSABATHMT from L. japonica var. chinensis were cloned according to the gene fragments in cDNA library. The LjSABATHMT protein was characterized by bioinformatics analysis. SABATH family phylogenetic tree were built by MEGA 5.0. The transcripted level of SABATHMT orthologous were analyzed in different organs and different flower periods of L. japonica and L. japonica var. chinensis using RT-PCR analysis. Intron sequences of SABATHMT orthologous were also analyzied. The cDNA of LjSABATHMT was 1 251 bp, had a complete coding frame with 365 amino acids. The protein had the conservative SABATHMT domain, and phylogenetic tree showed that it may be a salicylic acid/benzoic acid methyltransferase. Higher expression of SABATH methyltransferase orthologous was found in flower. The intron sequence of L. japonica and L. japonica var. chinensis had rich polymorphism, and two SNP are unique genotype of L. japonica var. chinensis. The motif elements in two orthologous genes were significant differences. The intron difference of SABATH methyltransferase orthologous could be inducing to difference of gene expression between L. japonica and L. japonica var. chinensis. These results will provide important base on regulating active compounds of L. japonica.

A hybrid PSO technique for procuring VAR ancillary service in the deregulated electricity markets

Energy Technology Data Exchange (ETDEWEB)

El-Araby, E.E. [Department of Electrical Engineering, Suez Canal University (Egypt); Yorino, Naoto [Department of Artificial Complex Systems Engineering, Hiroshima University (Japan)

2010-07-15

This paper develops a new market-based technique for acquiring VAR ancillary service in the electricity market. The main objective of the developed market is to enable transmission operator ''TO'' to procure VAR service in a long term contract from the critical VAR providers that satisfy minimum VAR service payment while maintaining system security. Reactive power control problem for voltage stability is introduced into the VAR market problem in an explicit manner for normal and emergency states. An integration of particle swarm optimization ''PSO'' is presented with successive linear programming ''SLP'' for dealing with the VAR ancillary service problem. The problem is formulated as a large-scale nonlinear constrained optimization problem with a non-differentiable objective function representing VAR payment and operational costs. This type of problem is hard to be treated straightforwardly by the classical optimization methods. Therefore, we propose here a two-layer hybrid PSO/SLP approach, which is suited for carrying out the difficulties associated with non-differentiable and discontinuous objective functions. The proposed method has been examined on the standard IEEE 57 bus-system and compared with GA/SLP method to demonstrate its capability. (author)

Adenosine 3':5'-cyclic monophosphate in higher plants: Isolation and characterization of adenosine 3':5'-cyclic monophosphate from Kalanchoe and Agave.

Science.gov (United States)

Ashton, A R; Polya, G M

1977-01-01

1.3':5'-Cyclic AMP was extensively purified from Kalanchoe daigremontiana and Agave americana by neutral alumina and anion- and cation-exchange column chromatography. Inclusion of 3':5'-cyclic [8-3H]AMP from the point of tissue extraction permitted calculation of yields. The purification procedure removed contaminating material that was shown to interfere with the 3':5'-cyclic AMP estimation and characterization procedures. 2. The partially purified 3':5'-cyclic AMP was quantified by means of a radiochemical saturation assay using an ox heart 3':5'-cyclic AMP-binding protein and by an assay involving activation of a mammalian protein kinase. 3. The plant 3':5'-cyclic AMP co-migrated with 3':5'-cyclic [8-3H]AMP on cellulose chromatography, poly(ethyleneimine)-cellulose chromatography and silica-gel t.l.c. developed with several solvent systems. 4. The plant 3':5'-cyclic AMP was degraded by ox heart 3':5'-cyclic nucleotide phosphodiesterase at the same rates as authentic 3':5'-cyclic AMP. 1-Methyl-3-isobutylxanthine (1 mM), a specific inhibitor of the 3':5'-cyclic nucleotide phosphodieterase, completely inhibited such degradation. 5. The concentrations of 3':5'-cyclic AMP satisfying the above criteria in Kalanchoe and Agave were 2-6 and 1 pmol/g fresh wt. respectively. Possible bacterial contribution to these analyses was estimated to be less than 0.002pmol/g fresh wt. Evidence for the occurrence of 3':5'-cyclic AMP in plants is discussed. PMID:196595

Nuevos taxones vegetales alóctonos de jardinería en el área continental de NE de España: comportamiento e historia

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GUILLOT, D

2010-01-01

Full Text Available This paper provides information about two topics rarely found in literature on invasions: 1-the record of succulent species naturalised within a continental-type climate area (Teruel, NE Spain, 2-the distinction between taxonomical varieties of invasive taxa. Besides, historical information on introduction, area of origin and taxonomical consideration is provided for each taxa. A. americana var. marginata Trel, Agave ingens Berger, Malephora purpureo-crocea (Haw. Schwantes and Sedum dendroideum DC. subsp. praealtum (A. DC. R. T. Clausen are recorded for the first time in the area.

Arundina graminifolia var. revoluta (Arethuseae, Orchidaceae) has fern-type rheophyte characteristics in the leaves.

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Yorifuji, Eri; Ishikawa, Naoko; Okada, Hiroshi; Tsukaya, Hirokazu

2015-03-01

Morphological and molecular variation between Arundina graminifolia var. graminifolia and the dwarf variety, A. graminifolia var. revoluta, was examined to assess the validity of their taxonomic characteristics and genetic background for identification. Morphological analysis in combination with field observations indicated that A. graminifolia var. revoluta is a rheophyte form of A. graminifolia characterized by narrow leaves, whereas the other morphological characteristics described for A. graminifolia var. revoluta, such as smaller flowers and short stems, were not always accompanied by the narrower leaf phenotype. Molecular analysis based on matK sequences indicated that only partial differentiation has occurred between A. graminifolia var. graminifolia and A. graminifolia var. revoluta. Therefore, we should consider the rheophyte form an ecotype rather than a variety. Anatomical observations of the leaves revealed that the rheophyte form of A. graminifolia possessed characteristics of the rheophytes of both ferns and angiosperms, such as narrower palisade tissue cells and thinner spongy tissue cells, as well as fewer cells in the leaf-width direction and fewer mesophyll cell layers.

An orientin derivative isolated from Passiflora tripartita var. mollissima

OpenAIRE

Ramos, Freddy A.; Castellanos, Leonardo; López, César; Palacios, Lizeth; Duque, Carmenza; Pacheco, Ricardo; Guzmán, Antonio

2010-01-01

Passiflora tripartita var. mollisima (banana passion fruit) is an edible fruit widespread in the Andean highlands of Colombia and Ecuador. The fruit is used for juices as well as for the sedative properties of the leaves. As a contribution to the chemical characterization of this species, a new compound, 4'- methoxyluteolin-8-C-6”acetylglucopyranoside, was isolated from the ethanolic extract of Passiflora tripartita var. mollisima leaves and identified by spectroscopical data (NMR, MS, UV).

Plasmodium falciparum var Gene Silencing Is Determined by cis DNA Elements That Form Stable and Heritable Interactions ▿

Science.gov (United States)

Swamy, Lakshmi; Amulic, Borko; Deitsch, Kirk W.

2011-01-01

Antigenic variation in the human malaria parasite Plasmodium falciparum depends on the transcriptional regulation of the var gene family. In each individual parasite, mRNA is expressed exclusively from 1 var gene out of ∼60, while the rest of the genes are transcriptionally silenced. Both modifications to chromatin structure and DNA regulatory elements associated with each var gene have been implicated in the organization and maintenance of the silent state. Whether silencing is established at the level of entire chromosomal regions via heterochromatin spreading or at the level of individual var promoters through the action of a silencing element within each var intron has been debated. Here, we consider both possibilities, using clonal parasite lines carrying chromosomally integrated transgenes. We confirm a previous finding that the loss of an adjacent var intron results in var promoter activation and further show that transcriptional activation of a var promoter within a cluster does not affect the transcriptional activity of neighboring var promoters. Our results provide more evidence for the hypothesis that var genes are primarily silenced at the level of an individual gene, rather than by heterochromatin spreading. We also tested the intrinsic directionality of an intron's silencing effect on upstream or downstream var promoters. We found that an intron is capable of silencing in either direction and that, once established, a var promoter-intron pair is stably maintained through many generations, suggesting a possible role in epigenetic memory. This study provides insights into the regulation of endogenous var gene clusters. PMID:21317310

Can reported VaR be used as an indicator of the volatility of share prices? Evidence from UK banks.

OpenAIRE

Ou, Shian Kao

2006-01-01

Value at Risk (VaR) is used as an indicator to measure the risks contained in a firm. With the uprising development of VaR theory and computational techniques, the VaR is nowadays adopted by banks and reported in annual reports. Since the method to calculate VaR is questioned, and the reported VaR can not be thoroughly audited, this paper attempts to find the relationship between the reported VaR and the volatility of share price for UK listed banks. This paper reviews literature about VaR an...

A novel virus-like particle based vaccine platform displaying the placental malaria antigen VAR2CSA

DEFF Research Database (Denmark)

Thrane, Susan; Janitzek, Christoph M; Agerbæk, Mette Ø

2015-01-01

, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of parasites to CSA. This study demonstrates that the described Avi-L1 VLP-platform may serve as a versatile system for facilitating optimal VLP......SA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however...

iVAR: a program for imputing missing data in multivariate time series using vector autoregressive models.

Science.gov (United States)

Liu, Siwei; Molenaar, Peter C M

2014-12-01

This article introduces iVAR, an R program for imputing missing data in multivariate time series on the basis of vector autoregressive (VAR) models. We conducted a simulation study to compare iVAR with three methods for handling missing data: listwise deletion, imputation with sample means and variances, and multiple imputation ignoring time dependency. The results showed that iVAR produces better estimates for the cross-lagged coefficients than do the other three methods. We demonstrate the use of iVAR with an empirical example of time series electrodermal activity data and discuss the advantages and limitations of the program.

Population genomics of the immune evasion (var genes of Plasmodium falciparum.

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Alyssa E Barry

2007-03-01

Full Text Available Var genes encode the major surface antigen (PfEMP1 of the blood stages of the human malaria parasite Plasmodium falciparum. Differential expression of up to 60 diverse var genes in each parasite genome underlies immune evasion. We compared the diversity of the DBLalpha domain of var genes sampled from 30 parasite isolates from a malaria endemic area of Papua New Guinea (PNG and 59 from widespread geographic origins (global. Overall, we obtained over 8,000 quality-controlled DBLalpha sequences. Within our sampling frame, the global population had a total of 895 distinct DBLalpha "types" and negligible overlap among repertoires. This indicated that var gene diversity on a global scale is so immense that many genomes would need to be sequenced to capture its true extent. In contrast, we found a much lower diversity in PNG of 185 DBLalpha types, with an average of approximately 7% overlap among repertoires. While we identify marked geographic structuring, nearly 40% of types identified in PNG were also found in samples from different countries showing a cosmopolitan distribution for much of the diversity. We also present evidence to suggest that recombination plays a key role in maintaining the unprecedented levels of polymorphism found in these immune evasion genes. This population genomic framework provides a cost effective molecular epidemiological tool to rapidly explore the geographic diversity of var genes.

Sporozoite Route of Infection Influences In Vitro var Gene Transcription of Plasmodium falciparum Parasites From Controlled Human Infections.

Science.gov (United States)

Dimonte, Sandra; Bruske, Ellen I; Hass, Johanna; Supan, Christian; Salazar, Carmen L; Held, Jana; Tschan, Serena; Esen, Meral; Flötenmeyer, Matthias; Koch, Iris; Berger, Jürgen; Bachmann, Anna; Sim, Betty K L; Hoffman, Stephen L; Kremsner, Peter G; Mordmüller, Benjamin; Frank, Matthias

2016-09-15

Antigenic variation in Plasmodium falciparum is mediated by the multicopy var gene family. Each parasite possesses about 60 var genes, and switching between active var loci results in antigenic variation. In the current study, the effect of mosquito and host passage on in vitro var gene transcription was investigated. Thirty malaria-naive individuals were inoculated by intradermal or intravenous injection with cryopreserved, isogenic NF54 P. falciparum sporozoites (PfSPZ) generated from 1 premosquito culture. Microscopic parasitemia developed in 22 individuals, and 21 in vitro cultures were established. The var gene transcript levels were determined in early and late postpatient cultures and in the premosquito culture. At the early time point, all cultures preferentially transcribed 8 subtelomeric var genes. Intradermal infections had higher var gene transcript levels than intravenous infections and a significantly longer intrahost replication time (P = .03). At the late time point, 9 subtelomeric and 8 central var genes were transcribed at the same levels in almost all cultures. Premosquito and late postpatient cultures transcribed the same subtelomeric and central var genes, except for var2csa  The duration of intrahost replication influences in vitro var gene transcript patterns. Differences between premosquito and postpatient cultures decrease with prolonged in vitro growth. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Disruption of var2csa gene impairs placental malaria associated adhesion phenotype.

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Nicola K Viebig

Full Text Available Infection with Plasmodium falciparum during pregnancy is one of the major causes of malaria related morbidity and mortality in newborn and mothers. The complications of pregnancy-associated malaria result mainly from massive adhesion of Plasmodium falciparum-infected erythrocytes (IE to chondroitin sulfate A (CSA present in the placental intervillous blood spaces. Var2CSA, a member of the P. falciparum erythrocyte membrane protein 1 (PfEMP1 family is the predominant parasite ligand mediating CSA binding. However, experimental evidence suggests that other host receptors, such as hyaluronic acid (HA and the neonatal Fc receptor, may also support placental binding. Here we used parasites in which var2csa was genetically disrupted to evaluate the contribution of these receptors to placental sequestration and to identify additional adhesion receptors that may be involved in pregnancy-associated malaria. By comparison to the wild-type parasites, the FCR3delta var2csa mutants could not be selected for HA adhesion, indicating that var2csa is not only essential for IE cytoadhesion to the placental receptor CSA, but also to HA. However, further studies using different pure sources of HA revealed that the previously observed binding results from CSA contamination in the bovine vitreous humor HA preparation. To identify CSA-independent placental interactions, FCR3delta var2csa mutant parasites were selected for adhesion to the human placental trophoblastic BeWo cell line. BeWo selected parasites revealed a multi-phenotypic adhesion population expressing multiple var genes. However, these parasites did not cytoadhere specifically to the syncytiotrophoblast lining of placental cryosections and were not recognized by sera from malaria-exposed women in a parity dependent manner, indicating that the surface molecules present on the surface of the BeWo selected population are not specifically expressed during the course of pregnancy-associated malaria. Taken

Does animal-mediated seed dispersal facilitate the formation of Pinus armandii-Quercus aliena var. acuteserrata forests?

Science.gov (United States)

Yu, Fei; Wang, Dexiang; Yi, Xianfeng; Shi, Xiaoxiao; Huang, Yakun; Zhang, Hongwu; Zhang, XinPing

2014-01-01

The Pinus armandii and Quercus aliena var. acuteserrata mixed forest is one of the major forest types in the Qinling Mountains, China. P. armandii is considered to be a pioneer species during succession and it is usually invaded by late successional Q. aliena var. acuteserrata. However, the mechanism that underlies its invasion remains unclear. In the present study, we tracked seed dispersal of P. armandii and Q. aliena var. acuteserrata using coded plastic tags in the western, middle and eastern Qinling Mountains to elucidate the invasion process in the mixed forests. Our results indicated that the seeds of both P. armandii and Q. aliena var. acuteserrata were removed rapidly in the Qinling Mountains, and there were no differences in the seed removal rates between the two species. There were significant differences in rodent seed-eating and caching strategies between the two tree species. For P. armandii, seeds were more likely to be eaten in situ than those of Q. aliena var. acuteserrata in all plots. By contrast, the acorns of Q. aliena var. acuteserrata were less frequently eaten in situ, but more likely to be removed and cached. Q. aliena var. acuteserrata acorns had significantly longer dispersal distances than P. armandii seeds in all plots. Although P. armandii seeds were less likely to be dispersed into the Q. aliena var. acuteserrata stands, over 30% of the released acorns were transported into the P. armandii stands where they established five seedlings. Based on the coupled recruitment patterns of P. armandii and Q. aliena var. acuteserrata, we suggest that the animal-mediated seed dispersal contributes to the formation of Pinus armandii-Quercus aliena var. acuteserrata forests.

[Negative air ions generated by plants upon pulsed electric field stimulation applied to soil].

Science.gov (United States)

Wu, Ren-ye; Deng, Chuan-yuan; Yang, Zhi-jian; Weng, Hai-yong; Zhu, Tie-jun-rong; Zheng, Jin-gui

2015-02-01

This paper investigated the capacity of plants (Schlumbergera truncata, Aloe vera var. chinensis, Chlorophytum comosum, Schlumbergera bridgesii, Gymnocalycium mihanovichii var. friedrichii, Aspidistra elatior, Cymbidium kanran, Echinocactus grusonii, Agave americana var. marginata, Asparagus setaceus) to generate negative air ions (NAI) under pulsed electric field stimulation. The results showed that single plant generated low amounts of NAI in natural condition. The capacity of C. comosum and G. mihanovichii var. friedrichii generated most NAI among the above ten species, with a daily average of 43 ion · cm(-3). The least one was A. americana var. marginata with the value of 19 ion · cm(-3). When proper pulsed electric field stimulation was applied to soil, the NAI of ten plant species were greatly improved. The effect of pulsed electric field u3 (average voltage over the pulse period was 2.0 x 10(4) V, pulse frequency was 1 Hz, and pulse duration was 50 ms) was the greatest. The mean NAI concentration of C. kanran was the highest 1454967 ion · cm(-3), which was 48498.9 times as much as that in natural condition. The lowest one was S. truncata with the value of 34567 ion · cm(-3), which was 843.1 times as much as that in natural condition. The capacity of the same plants to generate negative air ion varied extremely under different intensity pulsed electric fields.

Kalman Filter or VAR Models to Predict Unemployment Rate in Romania?

Directory of Open Access Journals (Sweden)

Simionescu Mihaela

2015-06-01

Full Text Available This paper brings to light an economic problem that frequently appears in practice: For the same variable, more alternative forecasts are proposed, yet the decision-making process requires the use of a single prediction. Therefore, a forecast assessment is necessary to select the best prediction. The aim of this research is to propose some strategies for improving the unemployment rate forecast in Romania by conducting a comparative accuracy analysis of unemployment rate forecasts based on two quantitative methods: Kalman filter and vector-auto-regressive (VAR models. The first method considers the evolution of unemployment components, while the VAR model takes into account the interdependencies between the unemployment rate and the inflation rate. According to the Granger causality test, the inflation rate in the first difference is a cause of the unemployment rate in the first difference, these data sets being stationary. For the unemployment rate forecasts for 2010-2012 in Romania, the VAR models (in all variants of VAR simulations determined more accurate predictions than Kalman filter based on two state space models for all accuracy measures. According to mean absolute scaled error, the dynamic-stochastic simulations used in predicting unemployment based on the VAR model are the most accurate. Another strategy for improving the initial forecasts based on the Kalman filter used the adjusted unemployment data transformed by the application of the Hodrick-Prescott filter. However, the use of VAR models rather than different variants of the Kalman filter methods remains the best strategy in improving the quality of the unemployment rate forecast in Romania. The explanation of these results is related to the fact that the interaction of unemployment with inflation provides useful information for predictions of the evolution of unemployment related to its components (i.e., natural unemployment and cyclical component.

PERHITUNGAN VaR PORTOFOLIO SAHAM MENGGUNAKAN DATA HISTORIS DAN DATA SIMULASI MONTE CARLO

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WAYAN ARTHINI

2012-09-01

Full Text Available Value at Risk (VaR is the maximum potential loss on a portfolio based on the probability at a certain time.  In this research, portfolio VaR values calculated from historical data and Monte Carlo simulation data. Historical data is processed so as to obtain stock returns, variance, correlation coefficient, and variance-covariance matrix, then the method of Markowitz sought proportion of each stock fund, and portfolio risk and return portfolio. The data was then simulated by Monte Carlo simulation, Exact Monte Carlo Simulation and Expected Monte Carlo Simulation. Exact Monte Carlo simulation have same returns and standard deviation  with historical data, while the Expected Monte Carlo Simulation satistic calculation similar to historical data. The results of this research is the portfolio VaR  with time horizon T=1, T=10, T=22 and the confidence level of 95 %, values obtained VaR between historical data and Monte Carlo simulation data with the method exact and expected. Value of VaR from both Monte Carlo simulation is greater than VaR historical data.

CALIDAD SANITARIA DE ALIMENTOS ELABORADOS CON GUSANO ROJO DE AGAVE (Comadia redtembacheri H.) EN SAN JUAN TEOTIHUACÁN, ESTADO DE MÉXICO, MÉXICO

OpenAIRE

Beverly Ramos-Rostro

2016-01-01

La tendencia de que la gastronomía y los alimentos regio - nales sean parte de las experiencias turísticas es creciente. El gusano rojo de maguey o agave ( Comadia redtembacheri Hammershmidt , 1848 Lepidóptera Cossidae) es un insecto comestible recolectado en algunas entidades de México y se emplea para elaborar especialidades gastronómicas comercia - lizadas en corredores turísticos y gastronómicos por lo que la calidad sanitaria de este...

Generation of antigenic diversity in Plasmodium falciparum by structured rearrangement of Var genes during mitosis.

Science.gov (United States)

Claessens, Antoine; Hamilton, William L; Kekre, Mihir; Otto, Thomas D; Faizullabhoy, Adnan; Rayner, Julian C; Kwiatkowski, Dominic

2014-12-01

The most polymorphic gene family in P. falciparum is the ∼60 var genes distributed across parasite chromosomes, both in the subtelomeres and in internal regions. They encode hypervariable surface proteins known as P. falciparum erythrocyte membrane protein 1 (PfEMP1) that are critical for pathogenesis and immune evasion in Plasmodium falciparum. How var gene sequence diversity is generated is not currently completely understood. To address this, we constructed large clone trees and performed whole genome sequence analysis to study the generation of novel var gene sequences in asexually replicating parasites. While single nucleotide polymorphisms (SNPs) were scattered across the genome, structural variants (deletions, duplications, translocations) were focused in and around var genes, with considerable variation in frequency between strains. Analysis of more than 100 recombination events involving var exon 1 revealed that the average nucleotide sequence identity of two recombining exons was only 63% (range: 52.7-72.4%) yet the crossovers were error-free and occurred in such a way that the resulting sequence was in frame and domain architecture was preserved. Var exon 1, which encodes the immunologically exposed part of the protein, recombined in up to 0.2% of infected erythrocytes in vitro per life cycle. The high rate of var exon 1 recombination indicates that millions of new antigenic structures could potentially be generated each day in a single infected individual. We propose a model whereby var gene sequence polymorphism is mainly generated during the asexual part of the life cycle.

[Correlation between distribution of rhizospheric microorganisms and contents of steroidal saponins of Paris polyphylla var. yunnanensis].

Science.gov (United States)

Zhou, Nong; Qi, Wen-hua; Xiao, Guo-sheng; Ding, Bo; Zhang, Hua; Guo, Dong-qin; Shen, Wei

2015-03-01

In this paper, the varying pattern of the amount of rhizospheric microorganisms, including bacteria, actinomycetes and fungus, was observed during the cultivation of Paris polyphylla var. yunnanensis. And the correlations between number of rhizospheric microorganisms and the quality of P. polyphylla var. yunnanensis were also studied. The results showed that the rhizospheric microorganism source of P. polyphylla var. yunnanensis was rich. The distribution of rhizospheric microorganisms (soil bacteria, fungus, actinomycetes, potassium-solubilizing bacteria, inorganic phosphorus-solubilizing bacteria, organic phosphorus-solubilizing bacteria) collected from different origin places existed significant difference (P the amount of actinomycetes > the amount of fungus. The medicinal quality of P. polyphylla var. yunnanensis was influenced by their habits, and the increase of cultivation years caused the obvious decrease of the quality of P. polyphylla var. yunnanensis. Therefore, the increase of cultivation years will cause the variation of the soil micro-ecology flora, and decrease the nutrient absorption and the utilization of P. polyphylla var. yunnanensis, which will make the decrease of the medical quality of P. polyphylla var. yunnanensis.

A molecular epidemiological study of var gene diversity to characterize the reservoir of Plasmodium falciparum in humans in Africa.

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Donald S Chen

2011-02-01

Full Text Available The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to mosquito.We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1% var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences.Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population exists.

A Molecular Epidemiological Study of var Gene Diversity to Characterize the Reservoir of Plasmodium falciparum in Humans in Africa

Science.gov (United States)

Leliwa-Sytek, Aleksandra; Smith, Terry-Ann; Peterson, Ingrid; Brown, Stuart M.; Migot-Nabias, Florence; Deloron, Philippe; Kortok, Moses M.; Marsh, Kevin; Daily, Johanna P.; Ndiaye, Daouda; Sarr, Ousmane; Mboup, Souleymane; Day, Karen P.

2011-01-01

Background The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to mosquito. Methodology/Principal Findings We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1%) var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences. Conclusions/Significance Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population

Feasibility of Stochastic Voltage/VAr Optimization Considering Renewable Energy Resources for Smart Grid

Science.gov (United States)

Momoh, James A.; Salkuti, Surender Reddy

2016-06-01

This paper proposes a stochastic optimization technique for solving the Voltage/VAr control problem including the load demand and Renewable Energy Resources (RERs) variation. The RERs often take along some inputs like stochastic behavior. One of the important challenges i. e., Voltage/VAr control is a prime source for handling power system complexity and reliability, hence it is the fundamental requirement for all the utility companies. There is a need for the robust and efficient Voltage/VAr optimization technique to meet the peak demand and reduction of system losses. The voltages beyond the limit may damage costly sub-station devices and equipments at consumer end as well. Especially, the RERs introduces more disturbances and some of the RERs are not even capable enough to meet the VAr demand. Therefore, there is a strong need for the Voltage/VAr control in RERs environment. This paper aims at the development of optimal scheme for Voltage/VAr control involving RERs. In this paper, Latin Hypercube Sampling (LHS) method is used to cover full range of variables by maximally satisfying the marginal distribution. Here, backward scenario reduction technique is used to reduce the number of scenarios effectively and maximally retain the fitting accuracy of samples. The developed optimization scheme is tested on IEEE 24 bus Reliability Test System (RTS) considering the load demand and RERs variation.

The Burr X Pareto Distribution: Properties, Applications and VaR Estimation

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Mustafa Ç. Korkmaz

2017-12-01

Full Text Available In this paper, a new three-parameter Pareto distribution is introduced and studied. We discuss various mathematical and statistical properties of the new model. Some estimation methods of the model parameters are performed. Moreover, the peaks-over-threshold method is used to estimate Value-at-Risk (VaR by means of the proposed distribution. We compare the distribution with a few other models to show its versatility in modelling data with heavy tails. VaR estimation with the Burr X Pareto distribution is presented using time series data, and the new model could be considered as an alternative VaR model against the generalized Pareto model for financial institutions.

Testing popular VaR models in EU new member and candidate states

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Saša Žiković

2007-12-01

Full Text Available The impact of allowing banks to calculate their capital requirement based on their internal VaR models, and the impact of regulation changes on banks in transitional countries has not been well studied. This paper examines whether VaR models that are created and suited for developed markets apply to the volatile stock markets of EU new member and candidate states (Bulgaria, Romania, Croatia and Turkey. Nine popular VaR models are tested on five stock indexes from EU new member and candidate states. Backtesting results show that VaR models commonly used in developed stock markets are not well suited for measuring market risk in these markets. Presented findings bear very important implications that have to be addressed by regulators and risk practitioners operating in EU new member andcandidate states. Risk managers have to start thinking outside the frames set by their parent companies or else investors present in these markets may find themselves in serious trouble, dealing with losses that they have not been expecting. National regulators have to take into consideration that simplistic VaR models that are widely used in some developed countries are not well suited for these illiquid and developing stock markets.

Comparison of the specificity of antibodies to VAR2CSA in Cameroonian multigravidae with and without placental malaria

DEFF Research Database (Denmark)

Babakhanyan, Anna; Fang, Rui; Wey, Andrew

2015-01-01

BACKGROUND: Antibodies (Ab) to VAR2CSA prevent Plasmodium falciparum-infected erythrocytes from sequestrating in the placenta, i.e., prevent placental malaria (PM). The specificity of Ab to VAR2CSA associated with absence of PM is unknown. Accordingly, differences in the specificity of Ab to VAR2......CSA were compared between multigravidae with and without PM who had Ab to VAR2CSA. METHODS: In a retrospective case-control study, plasma collected from Cameroonian multigravidae with (n = 96) and without (n = 324) PM were screened in 21 assays that measured antibody levels to full length VAR2CSA (FV2......), individual VAR2CSA DBL domains, VAR2CSA domains from different genetic backgrounds (variants), as well as proportion of high avidity Ab to FV2. RESULTS: Multigravidae with and without PM had similar levels of Ab to FV2, the six VAR2CSA DBL domains and different variants, while the proportion of high avidity...

Cloning of the Repertoire of Individual Plasmodium falciparum var Genes Using Transformation Associated Recombination (TAR)

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Schmid, Christoph D.; Bühlmann, Tobias; Louis, Edward J.; Beck, Hans-Peter

2011-01-01

One of the major virulence factors of the malaria causing parasite is the Plasmodium falciparum encoded erythrocyte membrane protein 1 (PfEMP1). It is translocated to It the membrane of infected erythrocytes and expressed from approximately 60 var genes in a mutually exclusive manner. Switching of var genes allows the parasite to alter functional and antigenic properties of infected erythrocytes, to escape the immune defense and to establish chronic infections. We have developed an efficient method for isolating VAR genes from telomeric and other genome locations by adapting transformation-associated recombination (TAR) cloning, which can then be analyzed and sequenced. For this purpose, three plasmids each containing a homologous sequence representing the upstream regions of the group A, B, and C var genes and a sequence homologous to the conserved acidic terminal segment (ATS) of var genes were generated. Co-transfection with P. falciparum strain ITG2F6 genomic DNA in yeast cells yielded 200 TAR clones. The relative frequencies of clones from each group were not biased. Clones were screened by PCR, as well as Southern blotting, which revealed clones missed by PCR due to sequence mismatches with the primers. Selected clones were transformed into E. coli and further analyzed by RFLP and end sequencing. Physical analysis of 36 clones revealed 27 distinct types potentially representing 50% of the var gene repertoire. Three clones were selected for sequencing and assembled into single var gene containing contigs. This study demonstrates that it is possible to rapidly obtain the repertoire of var genes from P. falciparum within a single set of cloning experiments. This technique can be applied to individual isolates which will provide a detailed picture of the diversity of var genes in the field. This is a powerful tool to overcome the obstacles with cloning and assembly of multi-gene families by simultaneously cloning each member. PMID:21408186

Complete mitochondrial genome of Xingguo red carp (Cyprinus carpio var. singuonensis) and purse red carp (Cyprinus carpio var. wuyuanensis).

Science.gov (United States)

Hu, Guang-Fu; Liu, Xiang-Jiang; Li, Zhong; Liang, Hong-Wei; Hu, Shao-Na; Zou, Gui-Wei

2016-01-01

The complete mitochondrial genomes of Xingguo red carp (Cyprinus carpio var. singuonensis) and purse red carp (Cyprinus carpio var. wuyuanensis) were sequenced. Comparison of these two mitochondrial genomes revealed that the mtDNAs of these two common carp varieties were remarkably similar in genome length, gene order and content, and AT content. However, size variation between these two mitochondrial genomes presented here showed 39 site differences in overall length. About 2 site differences were located in rRNAs, 3 in tRNAs, 3 in the control region, 31 in protein-coding genes. Thirty-one variable bases in the protein-coding regions between the two varieties mitochondrial sequences led to three variable amino acids, which were mainly located in the protein ND5 and ND4.

Anti-Inflammatory Effect of 3-O-[(6'-O-Palmitoyl-β-D-glucopyranosyl Sitosterol] from Agave angustifolia on Ear Edema in Mice

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Elizabeth Hernández-Valle

2014-09-01

Full Text Available In Mexico Agave angustifolia has traditionally been used to treat inflammation. The aim of this study was to measure the anti-inflammatory effect of the extract of A. angustifolia, the isolation and identification of active compounds. From the acetone extract two active fractions were obtained, (AsF13 and AaF16. For the characterization of pharmacological activity, the acute inflammatory model of mouse ear edema induced with TPA was used. The tissue exposed to TPA and treatments were subjected to two analysis, cytokine quantification (IL-1β, IL-6, IL-10 and TNF-α and histopathological evaluation. The active fraction (AaF16 consisted principally of 3-O-[(6'-O-palmitoyl-β-D-glucopyranpsyl] sitosterol. In AaF13 fraction was identified β-sitosteryl glucoside (2 and stigmasterol (3. The three treatments tested showed a concentration-dependent anti-inflammatory effect (AaAc Emax = 33.10%, EC50 = 0.126 mg/ear; AaF13 Emax = 54.22%, EC50 = 0.0524 mg/ear; AaF16 Emax = 61.01%, EC50 = 0.050 mg/ear. The application of TPA caused a significant increase on level of IL-1β, IL-6 and TNFα compared with basal condition, which was countered by any of the experimental treatments. Moreover, the experimental treatments induced a significant increase in the levels of IL-4 and IL-10, compared to the level observed when stimulated with TPA. Therefore, the anti-inflammatory effect of Agave angustifolia, is associated with the presence of 3-O-[(6'-O-palmitoyl-β-D-glucopyranosyl] sitosterol.

CO{sub 2} exchange, environmental productivity indices, and productivity of Agaves and Cacti under current and elevated atmospheric CO{sub 2} concentrations. Terminal report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

The research described in the proposal investigated net CO{sub 2} uptake and biomass accumulation for an extremely productive CAM plant, the prickly pear cactus Opuntia ficus-indica, under conditions of elevated CO{sub 2} concentrations for relatively long periods. The influences of soil water status, air temperature, and the photosynthetic photon flux (PPF) on net CO{sub 2} uptake over 24-h periods were evaluated to enable predictions to be made based on an Environmental Productivity Index (EPI). Specifically, EPI predicts the fraction of maximal daily net CO{sub 2} uptake based on prevailing environmental conditions. It is the product of indices for temperature, soil water, and intercepted PPF, each of which range from 0.00 when that index factor completely inhibits net CO{sub 2} uptake to 1.00 when no limitation occurs. For instance, the Water Index is 1.00 under wet conditions and decreases to 0.00 during prolonged drought. Although the major emphasis of the research was on net CO{sub 2} uptake and the resulting biomass production for O. ficus-indica, effects of elevated CO{sub 2} concentrations on root: shoot ratios and on the activities of the two carboxylating enzymes were also investigated. Moreover, experiments were also done on other CAM plants, including Agave deserti, Agave salmiana, and Hylocereus undatus, and Stenocereus queretaroensis.

CO{sub 2} exchange environmental productivity indices, and productivity of agaves and cacti under current and elevated atmospheric CO{sub 2} concentrations. Final report

Energy Technology Data Exchange (ETDEWEB)

Nobel, P.S.

1994-12-31

The research described in the proposal investigated net CO{sub 2} uptake and biomass accumulation for an extremely productive CAM plant, the prickly pear cactus Opuntia ficus-indica, under conditions of elevated CO{sub 2} concentrations for relatively long periods. The influences of soil water status, air temperature, and the photosynthetic photon flux (PPF) on net CO{sub 2} uptake over 24-h periods were evaluated to enable predictions to be made based on an Environmental Productivity Index (EPI). Specifically, EPI predicts the fraction of maximal daily net CO{sub 2} uptake based on prevailing environmental conditions. It is the product of indices for temperature, soil water, and intercepted PPF, each of which range from 0.00 when that index factor completely inhibits net CO{sub 2} uptake to 1.00 when no limitation occurs. For instance, the Water Index is 1.00 under wet conditions and decreases to 0.00 during prolonged drought. Although the major emphasis of the research was on net C0{sub 2} uptake and the resulting biomass production for O. ficus-indica, effects of elevated CO{sub 2} concentrations on root: shoot ratios and on the activities of the two carboxylating enzymes were also investigated. Moreover, experiments were also done on other CAM plants, including Agave deserti, Agave salmiana, and Hylocereus undatus, and Stenocereus queretaroensis.

Trans-acting GC-rich non-coding RNA at var expression site modulates gene counting in malaria parasite.

Science.gov (United States)

Guizetti, Julien; Barcons-Simon, Anna; Scherf, Artur

2016-11-16

Monoallelic expression of the var multigene family enables immune evasion of the malaria parasite Plasmodium falciparum in its human host. At a given time only a single member of the 60-member var gene family is expressed at a discrete perinuclear region called the 'var expression site'. However, the mechanism of var gene counting remains ill-defined. We hypothesize that activation factors associating specifically with the expression site play a key role in this process. Here, we investigate the role of a GC-rich non-coding RNA (ncRNA) gene family composed of 15 highly homologous members. GC-rich genes are positioned adjacent to var genes in chromosome-central gene clusters but are absent near subtelomeric var genes. Fluorescence in situ hybridization demonstrates that GC-rich ncRNA localizes to the perinuclear expression site of central and subtelomeric var genes in trans. Importantly, overexpression of distinct GC-rich ncRNA members disrupts the gene counting process at the single cell level and results in activation of a specific subset of var genes in distinct clones. We identify the first trans-acting factor targeted to the elusive perinuclear var expression site and open up new avenues to investigate ncRNA function in antigenic variation of malaria and other protozoan pathogens. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Orientation of the Fiscal Policy in Tunisia: Structural VAR Analysis

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Wissem Khanfir

2017-06-01

Full Text Available The objective of this paper is to indicate the orientation of fiscal policy in Tunisia, using the structural budget balance, during the period 1972-2014. For this purpose, we estimate a structural VAR model consisting of the fiscal deficit to current GDP ratio and the volume of economic activity represented by the real GDP. We estimate bivariate structural VAR in order to decompose fiscal deficit fluctuations into different disturbances.

Generation of antigenic diversity in Plasmodium falciparum by structured rearrangement of Var genes during mitosis.

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Antoine Claessens

2014-12-01

Full Text Available The most polymorphic gene family in P. falciparum is the ∼60 var genes distributed across parasite chromosomes, both in the subtelomeres and in internal regions. They encode hypervariable surface proteins known as P. falciparum erythrocyte membrane protein 1 (PfEMP1 that are critical for pathogenesis and immune evasion in Plasmodium falciparum. How var gene sequence diversity is generated is not currently completely understood. To address this, we constructed large clone trees and performed whole genome sequence analysis to study the generation of novel var gene sequences in asexually replicating parasites. While single nucleotide polymorphisms (SNPs were scattered across the genome, structural variants (deletions, duplications, translocations were focused in and around var genes, with considerable variation in frequency between strains. Analysis of more than 100 recombination events involving var exon 1 revealed that the average nucleotide sequence identity of two recombining exons was only 63% (range: 52.7-72.4% yet the crossovers were error-free and occurred in such a way that the resulting sequence was in frame and domain architecture was preserved. Var exon 1, which encodes the immunologically exposed part of the protein, recombined in up to 0.2% of infected erythrocytes in vitro per life cycle. The high rate of var exon 1 recombination indicates that millions of new antigenic structures could potentially be generated each day in a single infected individual. We propose a model whereby var gene sequence polymorphism is mainly generated during the asexual part of the life cycle.

Reversal of cisplatin resistance in non-small cell lung cancer stem cells by Taxus chinensis var.

Science.gov (United States)

Jiang, Y Q; Xu, X P; Guo, Q M; Xu, X C; Liu, Q Y; An, S H; Xu, J L; Su, F; Tai, J B

2016-09-02

Drug resistance in cells is a major impedance to successful treatment of lung cancer. Taxus chinensis var. inhibits the growth of tumor cells and promotes the synthesis of interleukins 1 and 2 and tumor necrosis factor, enhancing immune function. In this study, T. chinensis var.-induced cell death was analyzed in lung cancer cells (H460) enriched for stem cell growth in a defined serum-free medium. Taxus-treated stem cells were also analyzed for Rhodamine 123 (Rh-123) expression by flow cytometry, and used as a standard functional indicator of MDR. The molecular basis of T. chinensis var.-mediated drug resistance was established by real-time PCR analysis of ABCC1, ABCB1, and lung resistance-related protein (LRP) mRNA, and western blot analysis of MRP1, MDR1, and LRP. Our results revealed that stem cells treated with higher doses of T. chinensis var. showed significantly lower growth inhibition rates than did H460 cells (P var. and cisplatin was also significantly inhibited (P var. (P var.-treated stem cells showed significant downregulation of the ABCC1, ABCB1, and LRP mRNA and MRP1, MDR1, and LRP (P var.-mediated downregulation of MRP1, MDR1, and LRP might contribute to the reversal of drug resistance in non-small cell lung cancer stem cells.

Metabolomic variation of brassica rapa var. rapa (var. raapstelen) and raphanus sativus l. at different developmental stages

International Nuclear Information System (INIS)

Jahangir, M.; Farid, I.B.A.

2014-01-01

Brassica rapa (var. raapstelen) and Raphanus sativus (red radish) are being used as food and fodder while also known as model in recent plant research due to the diversity of metabolites as well as genetic resemblance to Arabidopsis. This study explains the change in metabolites (amino acids, organic acids, chlorophyll, carotenoids, tocopherols, ascorbic acid, sucrose, phenylpropanoids and glucosinolates) during plant development. In present study the metabolomic variation in relation to plant growth has been evaluated, for Brassica rapa (var. raapstelen) and red radish (Raphanus sativus) at three different developmental stages. A non-targeted and targeted metabolomic approach by NMR and HPLC in combination with Principal component analysis (PCA) of the data was used to identify phytochemicals being influenced by plant growth. The results lead to the better understanding of metabolic changes during plant development and show the importance of plant age with respect to the metabolomic profile of vegetables. (author)

Production of cellulose nanoparticles from blue agave waste treated with environmentally friendly processes.

Science.gov (United States)

Robles, Eduardo; Fernández-Rodríguez, Javier; Barbosa, Ananda M; Gordobil, Oihana; Carreño, Neftali L V; Labidi, Jalel

2018-03-01

Tequila elaboration leaves two main byproducts that are undervalued (bagasse and leaves). Organosolv pulping and Total Chlorine Free bleaching were integrated to obtain cellulose fibers from agricultural waste which consisted of blue agave bagasse and leaf fibers; together they represent a green process which valorizes biomass waste. The obtained celluloses were characterized by FT-IR, colorimetry, and SEM and their extraction yields were evaluated. These celluloses were used to produce cellulose nanocrystals and cellulose nanofibers. First, an acid hydrolysis was performed in a sonication bath to induce cavitation during the reaction to produce cellulose nanocrystals. Then a high-pressure homogenization was selected to produce cellulose nanofibers. These nanocelluloses were characterized by powder XRD, Nanosizer, zeta potential, NMR, and electronic microscopy. Results showed that cellulose from organosolv pulps bleached with TCF bleaching is suitable for nanocellulose production. Moreover, the use of a new step to separate cellulose nanocrystals resulted in yields almost doubling traditional yields, while the rest of the properties remained within the expected. Copyright © 2018 Elsevier Ltd. All rights reserved.

Genetic diversity of Clavispora lusitaniae isolated from Agave fourcroydes Lem, as revealed by DNA fingerprinting.

Science.gov (United States)

Pérez-Brito, Daisy; Magaña-Alvarez, Anuar; Lappe-Oliveras, Patricia; Cortes-Velazquez, Alberto; Torres-Calzada, Claudia; Herrera-Suarez, Teófilo; Larqué-Saavedra, Alfonso; Tapia-Tussell, Raul

2015-01-01

This study characterized Clavispora lusitaniae strains isolated from different stages of the processing and early fermentation of a henequen (Agave fourcroydes) spirit produced in Yucatan, Mexico using a molecular technique. Sixteen strains identified based on morphological features, obtained from different substrates, were typed molecularly. Nine different versions of the divergent D1/D2 domain of the large-subunit ribosomal DNA sequence were identified among the C. lusitaniae strains. The greatest degree of polymorphism was found in the 90-bp structural motif of the D2 domain. The MSP-PCR technique was able to differentiate 100% of the isolates. This study provides significant insight into the genetic diversity of the mycobiota present during the henequen fermentation process, especially that of C. lusitaniae, for which only a few studies in plants have been published. The applied MSP-PCR markers were very efficient in revealing olymorphisms between isolates of this species.

Clinical development of a VAR2CSA-based placental malaria vaccine PAMVAC

DEFF Research Database (Denmark)

Gbédandé, Komi; Fievet, Nadine; Viwami, Firmine

2017-01-01

Background  The antigen VAR2CSA plays a pivotal role in the pathophysiology of pregnancy-associated malaria (PAM) caused by Plasmodium falciparum. A VAR2CSA-based vaccine candidate, PAMVAC, is under development by an EU-funded multi-country consortium (PlacMalVac project). As part of PAMVAC...

In vitro antioxidant and anticancer effects of solvent fractions from Prunella vulgaris var. lilacina.

Science.gov (United States)

Hwang, Yu-Jin; Lee, Eun-Ju; Kim, Haeng-Ran; Hwang, Kyung-A

2013-11-09

Recently, considerable attention has been focused on exploring the potential antioxidant properties of plant extracts or isolated products of plant origin. Prunella vulgaris var. lilacina is widely distributed in Korea, Japan, China, and Europe, and it continues to be used to treat inflammation, eye pain, headache, and dizziness. However, reports on the antioxidant activities of P. vulgaris var. lilacina are limited, particularly concerning the relationship between its phenolic content and antioxidant capacity. In this study, we investigated the antioxidant and anticancer activities of an ethanol extract from P. vulgaris var. lilacina and its fractions. Dried powder of P. vulgaris var. lilacina was extracted with ethanol, and the extract was fractionated to produce the hexane fraction, butanol fraction, chloroform fraction and residual water fraction. The phenolic content was assayed using the Folin-Ciocalteu colorimetric method. Subsequently, the antioxidant activities of the ethanol extract and its fractions were analyzed employing various antioxidant assay methods including DPPH, FRAP, ABTS, SOD activity and production of reactive oxygen species. Additionally, the extract and fractions were assayed for their ability to exert cytotoxic activities on various cancer cells using the MTT assay. We also investigated the expression of genes associated with apoptotic cell death by RT-PCR. The total phenolic contents of the ethanol extract and water fraction of P. vulgaris var. lilacina were 303.66 and 322.80 mg GAE/g dry weight (or fractions), respectively. The results showed that the ethanol extract and the water fraction of P. vulgaris var. lilacina had higher antioxidant content than other solvent fractions, similar to their total phenolic content. Anticancer activity was also tested using the HepG2, HT29, A549, MKN45 and HeLa cancer cell lines. The results clearly demonstrated that the P. vulgaris var. lilacina ethanol extract induced significant cytotoxic effects

Subcellular distribution and chemical forms of thorium in Brassica juncea var. foliosa

International Nuclear Information System (INIS)

Zhou, Sai; Kai, Hailu; Zha, Zhongyong; Fang, Zhendong; Wang, Dingna; Du, Liang; Zhang, Dong; Feng, Xiaojie; Jin, Yongdong; Xia, Chuanqin

2016-01-01

Brassica juncea var. foliosa (B. juncea var. foliosa) is a promising species for thorium (Th) phytoextraction due to its large biomass, fast growth rate and high tolerance toward Th. To further understand the mechanisms of Th tolerance, the present study investigated the subcellular distribution and chemical forms of Th found in B. juncea var. foliosa Our results indicated that in both roots and leaves, Th contents in different parts of the cells follow the order of cell wall > membranes and soluble fraction > organelles. In particular, Transmission Electron Microscope (TEM) analysis showed that Th was abundantly located in cell walls of the roots. Additionally, when plants were exposed to different concentrations of Th, we have found that Th existed in B. juncea var. foliosa with different chemical forms. Much of the Th extracted by 2% acetic acid (HAc), 1 M NaCl and HCl in roots with the percentage distribution varied from 47.2% to 62.5%, while in leaves, most of the Th was in the form of residue and the subdominant amount of Th was extracted by HCl, followed by 2% HAc. This suggested that Th compartmentation in cytosol and integration with phosphate or proteins in cell wall might be responsible for the tolerance of B. juncea var. foliosa to the stress of Th. - Highlights: • Brassica juncea var. foliosa can adapt to the stress of Th(<200 μM) under hydroponic condition. • Th was selectively distributed on cell wall, membranes and soluble fraction. • Th mainly existed in low-toxicity forms which were benefit for Th tolerance.

Biochemical and histological characterization of Agave fourcroydes Lem. plants in vitro acclimatized

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Yunel Pérez Hernández

2016-10-01

Full Text Available Henequen (Agave fourcroydes Lem. is a representative crop of the province of Matanzas, Cuba, which has been exploited extensively for the quality of its fibers. The present work aimed to characterize from the biochemical and histological point of view henequen plants cv. 'Sac Ki' in vitro acclimatized. The biochemical indicators analyzed were concentration of soluble phenols, total soluble carbohydrates, reducing sugars, soluble proteins and total chlorophylls, as well as the relative contents of flavonoids, terpins and anthocyanins. In addition, a histological analysis of the epidermis was performed and the results were compared with plants of one month in rooting culture medium. In vitro acclimatized plants were subsequently transferred to the ex vitro conditions. The contents of total soluble carbohydrates, reducing sugars and chlorophylls decreased, whereas the levels of soluble phenols, proteins and secondary metabolites were higher in relation to in vitro plants rooted for 30 days. The epidermis of the in vitro acclimatized plants showed a greater development of the stomatal apparatus that could positively affect the ex vitro acclimatization, where a survival rate of 87% and a reduction of the acclimatization time were obtained.   Keywords: chlorophyll, henequen, phenol, reducing sugar

Silence, Metaperformance, and Communication in Pedro Almodóvar's "Hable con ella"

Science.gov (United States)

Fellie, Maria C.

2016-01-01

Many scenes in Pedro Almodóvar's "Hable con ella" (2002) include shots of metaperformances such as silent films, dances, television shows, concerts, and bullfights. Spectators often observe passive characters who are in turn observing. By presenting these performances within cinematic performance, Almodóvar highlights our role as viewers…

Chemopreventive and Anticancer Activities of Allium victorialis var. platyphyllum Extracts.

Science.gov (United States)

Kim, Hyun-Jeong; Park, Min Jeong; Park, Hee-Juhn; Chung, Won-Yoon; Kim, Ki-Rim; Park, Kwang-Kyun

2014-09-01

Allium victorialis var. platyphyllum is an edible perennial herb and has been used as a vegetable or as a Korean traditional medicine. Allium species have received much attention owing to their diverse pharmacological properties, including antioxidative, anti-inflammatory, and anticancer activities. However, A. victorialis var. platyphyllum needs more study. The chemopreventive potential of A. victorialis var. platyphyllum methanol extracts was examined by measuring 12-O-tetra-decanoylphorbol 13-acetate (TPA)-induced superoxide anion production in the differentiated HL-60 cells, TPA-induced mouse ear edema, and Ames/Salmonella mutagenicity. The apoptosis-inducing capabilities of the extracts were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, 4',6-diamidino-2-phenylindole staining, and the DNA fragmentation assay in human colon cancer HT-29 cells. Antimetastatic activities of the extracts were also investigated in an experimental mouse lung metastasis model. The methanol extracts of A. victorialis var. platyphyllum rhizome (AVP-R) and A. victorialis var. platyphyllum stem (AVP-S) dose-dependently inhibited the TPA-induced generation of superoxide anion in HL-60 cells and TPA-induced ear edema in mice, as well as 7,12-dimethylbenz[a]anthracene (DMBA) and tert-butyl hydroperoxide (t-BOOH) -induced bacterial mutagenesis. AVP-R and AVP-S reduced cell viability in a dose-related manner and induced apoptotic morphological changes and internucleosomal DNA fragmentation in HT-29 cells. In the experimental mouse lung metastasis model, the formation of tumor nodules in lung tissue was significantly inhibited by the treatment of the extracts. AVP-R and AVP-S possess antioxidative, anti-inflammatory, antimutagenic, proapoptotic, and antimetastatic activities. Therefore, these extracts can serve as a beneficial supplement for the prevention and treatment of cancer.

Amanitin and phallotoxin concentration in Amanita phalloides var. alba mushroom.

Science.gov (United States)

Kaya, Ertugrul; Yilmaz, Ismail; Sinirlioglu, Zeynep Aydin; Karahan, Selim; Bayram, Recep; Yaykasli, Kursat Oguz; Colakoglu, Serdar; Saritas, Ayhan; Severoglu, Zeki

2013-12-15

Although rarely seen, Amanita phalloides var. alba, a variety of A. phalloides type mushrooms, causes mushroom poisoning resulting in death. Since it is frequently confused with some edible mushrooms due to its white colored cap and macroscopic appearance, it becomes important in toxicological terms. Knowledge of the toxin amount contained in this mushroom type is invaluable in the treatment of cases involving poisoning. In this study, we examined the toxin levels of various parts of the A. phalloides var. alba mushroom growing Duzce region of Turkey. Toxin analyses were carried out for A. phalloides var. alba, which were collected from the forests Duzce region of Turkey in 2011, as a whole and also separately in its spore, pileus, gills, stipe and volva parts. The alpha amanitin, beta amanitin, gamma amanitin, phalloidin and phallacidine analyses of the mushrooms were carried out using the RP-HPLC method. A genetic analysis of the mushroom showed that it had similar genetic characteristics as A. phalloides and was a variety of it. The lowest toxins quantity was detected in spores, volva and stipe among all parts of the mushroom. The maximum amount of amatoxins was measured in the gills. The pileus also contained a high amount of amatoxins. Generally, amatoxins and phallotoxin concentrations were lower as compared to A. phalloides, but interestingly all toxins other than gamma toxin were higher in the spores of A. phalloides var. alba. The amount of toxin in all of its parts had sufficient concentrations to cause death. With this study, the amatoxin and phallotoxin concentrations in A. phalloides var. alba mushroom and in its parts have been revealed in detail for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Subcellular distribution and chemical forms of thorium in Brassica juncea var. foliosa.

Science.gov (United States)

Zhou, Sai; Kai, Hailu; Zha, Zhongyong; Fang, Zhendong; Wang, Dingna; Du, Liang; Zhang, Dong; Feng, Xiaojie; Jin, Yongdong; Xia, Chuanqin

2016-06-01

Brassica juncea var. foliosa (B. juncea var. foliosa) is a promising species for thorium (Th) phytoextraction due to its large biomass, fast growth rate and high tolerance toward Th. To further understand the mechanisms of Th tolerance, the present study investigated the subcellular distribution and chemical forms of Th found in B. juncea var. foliosa Our results indicated that in both roots and leaves, Th contents in different parts of the cells follow the order of cell wall > membranes and soluble fraction > organelles. In particular, Transmission Electron Microscope (TEM) analysis showed that Th was abundantly located in cell walls of the roots. Additionally, when plants were exposed to different concentrations of Th, we have found that Th existed in B. juncea var. foliosa with different chemical forms. Much of the Th extracted by 2% acetic acid (HAc), 1 M NaCl and HCl in roots with the percentage distribution varied from 47.2% to 62.5%, while in leaves, most of the Th was in the form of residue and the subdominant amount of Th was extracted by HCl, followed by 2% HAc. This suggested that Th compartmentation in cytosol and integration with phosphate or proteins in cell wall might be responsible for the tolerance of B. juncea var. foliosa to the stress of Th. Copyright © 2016 Elsevier Ltd. All rights reserved.

Taxonomic study on Japanese Salvia (Lamiaceae): Phylogenetic position of S. akiensis, and polyphyletic nature of S. lutescens var. intermedia.

Science.gov (United States)

Takano, Atsuko

2017-01-01

Both Salvia akiensis and S. lutescens (Lamiaceae) are endemic to Japan. Salvia akiensis was recently described in 2014 in the Chugoku (= SW Honshu) region, and each four varieties of S. lutescens distributed allopatrically. Among varieties in S. lutescens , var. intermedia show a disjunctive distribution in the Kanto (=E Honshu) and Kinki (= W Honshu) regions. Recent field studies of S. lutescens var. intermedia revealed several morphological differences between the Kanto and Kinki populations. Here, I evaluated these differences among Salvia lutescens var. intermedia and its allies with morphological analysis and molecular phylogenetic analyses of nuclear ribosomal DNA (internal and external transcribed spacer regions) and plastid DNA ( ycf1-rps15 spacer, rbcL , and trnL-F ) sequences. Both morphological analysis and molecular phylogenetic analyses showed that S. lutescens var. intermedia from the Kinki region and var. lutescens were closely related to each other. However, var. intermedia from the Kanto region exhibited an association with S. lutescens var. crenata and var. stolonifera, which also grew in eastern Japan, rather than var. intermedia in the Kinki region. These results indicated that S. lutescens var. intermedia is not a taxon with a disjunctive distribution, but a combination of two or more allopatric taxa. Present study also suggested that S. akiensis was most closely related to S. omerocalyx .

Assessment of goods and valuation of ecosystem services (AGAVES) San Pedro River Basin, United States and Mexico

Science.gov (United States)

Semmens, Darius; Kepner, William; Goodrich, David

2010-01-01

A consortium of federal, academic, and nongovernment organization (NGO) partners have established a collaborative research enterprise in the San Pedro River Basin to develop methods, standards, and tools to assess and value ecosystem goods and services. The central premise of ecosystem services research is that human condition is intrinsically linked to the environment. Human health and well-being (including economic prosperity) depend on important supporting, regulating, provisioning, and cultural services that we derive from our surrounding ecosystems. The AGAVES project is intended as a demonstration study for incorporating ecosystem services information into resource management policy and decisionmaking. Accordingly, a nested, multiscale project design has been adopted to address a range of stakeholder information requirements. This design will further facilitate an evaluation of how well methods developed in this project can be transferred to other areas.

Metabolomic variation of brassica rapa var. rapa (var. raapstelen) and raphanus sativus l. at different developmental stages

NARCIS (Netherlands)

Jahangir, M.; Abdel-Farid, I.B.; Vos, de C.H.R.; Jonker, H.H.; Choi, Y.H.; Verpoorte, R.

2014-01-01

Brassica rapa (var. raapstelen) and Raphanus sativus (red radish) are being used as food and fodder while also known as model in recent plant research due to the diversity of metabolites as well as genetic resemblance to Arabidopsis. This study explains the change in metabolites (amino acids,

A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA.

Directory of Open Access Journals (Sweden)

Susan Thrane

Full Text Available Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have failed during clinical testing, virus-like particle (VLP based vaccines (e.g., the licensed human papillomavirus vaccines have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response. We have developed a VLP vaccine display platform by identifying regions of the HPV16 L1 coat protein where a biotin acceptor site (AviTagTM can be inserted without compromising VLP-assembly. Subsequent biotinylation of Avi-L1 VLPs allow us to anchor monovalent streptavidin (mSA-fused proteins to the biotin, thereby obtaining a dense and repetitive VLP-display of the vaccine antigen. The mSA-VAR2CSA antigen was delivered on the Avi-L1 VLP platform and tested in C57BL/6 mice in comparison to two soluble protein-based vaccines consisting of naked VAR2CSA and mSA-VAR2CSA. The mSA-VAR2CSA Avi-L1 VLP and soluble mSA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of

Parasitosis intestinales en vendedores ambulantes de comida en Ciudad Bolívar, estado Bolívar, Venezuela | Intestinal parasitosis in food handlers from ciudad Bolívar, Bolívar state, Venezuela

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Ixora Requena

2017-11-01

Full Text Available A descriptive study was performed to determine the prevalence of intestinal parasites in a sample of apparently healthy individuals who sold food in streets in Los Proceres of Ciudad Bolívar, Bolívar State. Fecal samples were collected from 85 individuals, which were analyzed by means of direct examination, qualitative Kato, spontaneous sedimentation and Kinyoun staining. Each individual was filled a clinical epidemiological record and underwent anamnesis and oriented clinical examination. The assessed group comprised 50 women and 35 men with ages 14 to 57 years (mean 15.25 ± 4.21 years. From this group, 50 persons (58.82% were parasitized mainly by Blastocystis spp. (42.22%, Endolimax nana (11.11%, Entamoeba coli (6.67%, Giardia intestinalis (11.11%, Cryptosporidium spp. (11.11% and Cystoisospora belli (4.44%. There was no preference for gender or age (p > 0.05, and persons aged 20 to 25 years were the most affected group. Monoparasitism was observed in 56% (n = 28 cases and 44% (n = 22 of cases had other associated parasites, being the most frequent association between Blastocystis spp with Entamoeba coli and Endolimax nana. It is concluded that there is a high prevalence of intestinal parasitosis among street food handlers.

Evidence for in vitro and in vivo expression of the conserved VAR3 (type 3) plasmodium falciparum erythrocyte membrane protein 1

DEFF Research Database (Denmark)

Wang, Christian W; Lavstsen, Thomas; Bengtsson, Dominique C

2012-01-01

ABSTRACT: BACKGROUND: Members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) adhesion antigen family are major contributors to the pathogenesis of P. falciparum malaria infections. The PfEMP1-encoding var genes are among the most diverse sequences in nature, but three genes......, var1, var2csa and var3 are found conserved in most parasite genomes. The most severe forms of malaria disease are caused by parasites expressing a subset of antigenically conserved PfEMP1 variants. Thus the ubiquitous and conserved VAR3 PfEMP1 is of particular interest to the research field. Evidence...... of VAR3 expression on the infected erythrocyte surface has never been presented, and var3 genes have been proposed to be transcribed and expressed differently from the rest of the var gene family members. METHODS: In this study, parasites expressing VAR3 PfEMP1 were generated using anti-VAR3 antibodies...

Influence of LAR and VAR on Para-Aminopyridine Antimalarials Targetting Haematin in Chloroquine-Resistance.

Science.gov (United States)

Warhurst, David C; Craig, John C; Raheem, K Saki

2016-01-01

Antimalarial chloroquine (CQ) prevents haematin detoxication when CQ-base concentrates in the acidic digestive vacuole through protonation of its p-aminopyridine (pAP) basic aromatic nitrogen and sidechain diethyl-N. CQ export through the variant vacuolar membrane export channel, PFCRT, causes CQ-resistance in Plasmodium falciparum but 3-methyl CQ (sontochin SC), des-ethyl amodiaquine (DAQ) and bis 4-aminoquinoline piperaquine (PQ) are still active. This is determined by changes in drug accumulation ratios in parasite lipid (LAR) and in vacuolar water (VAR). Higher LAR may facilitate drug binding to and blocking PFCRT and also aid haematin in lipid to bind drug. LAR for CQ is only 8.3; VAR is 143,482. More hydrophobic SC has LAR 143; VAR remains 68,523. Similarly DAQ with a phenol substituent has LAR of 40.8, with VAR 89,366. In PQ, basicity of each pAP is reduced by distal piperazine N, allowing very high LAR of 973,492, retaining VAR of 104,378. In another bis quinoline, dichlorquinazine (DCQ), also active but clinically unsatisfactory, each pAP retains basicity, being insulated by a 2-carbon chain from a proximal nitrogen of the single linking piperazine. While LAR of 15,488 is still high, the lowest estimate of VAR approaches 4.9 million. DCQ may be expected to be very highly lysosomotropic and therefore potentially hepatotoxic. In 11 pAP antimalarials a quadratic relationship between logLAR and logResistance Index (RI) was confirmed, while log (LAR/VAR) vs logRI for 12 was linear. Both might be used to predict the utility of structural modifications.

BRINE SHRIMP LETHALITY BIOASSAY OF GLAUCIUM GRANDIFLORUM VAR. GRANDIFLORUM

OpenAIRE

A. SARI, Ç. ÜNSAL, İ. SARIOĞLU, A. SARI, Ç. ÜNSAL, İ. SARIOĞLU

2013-01-01

Türkiye'nin 3 farklı bölgesinden toplanan Glaucium grandiflorum Boiss. et Huet var. grandiflorum örneklerinin toprak üstü kısımlarından elde edilen alkaloit ekstreleri ve bu ekstrelerden elde edilen majör alkaloitler allokriptopin, protopİn, (+)-izokoridin, (+)-korİdin üzerinde brİne shrimp lethality testi yapılarak sitotoksisiteleri İncelenmiştir. Glaucium grandiflorum var. grandiflorum türünün 3 örneği de önemli oranda sitotoksik aktİvite göstermiştir. Allokriptopin, protopin, (+)-izok...

Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta

Directory of Open Access Journals (Sweden)

Segovia Lorenzo

2011-02-01

Full Text Available Abstract Background Expansins and expansin-like proteins loosen cellulose microfibrils, possibly through the rupture of intramolecular hydrogen bonds. Together with the use of lignocellulolytic enzymes, these proteins are potential molecular tools to treat plant biomass to improve saccharification yields. Results Here we describe a new type of expansin-related fungal protein that we have called loosenin. Its corresponding gene, loos1, from the basidiomycete Bjerkandera adusta, was cloned and heterologously expressed in Saccharomyces cerevisiae. LOOS1 is distantly related to plant expansins through the shared presence of a DPBB domain, however domain II found in plant expansins is absent. LOOS1 binds tightly to cellulose and chitin, and we demonstrate that cotton fibers become susceptible to the action of a commercial cellulase following treatment with LOOS1. Natural fibers of Agave tequilana also become susceptible to hydrolysis by cellulases after loosenin treatment. Conclusions LOOS1 is a new type of protein with disrupting activity on cellulose. LOOS1 binds polysaccharides, and given its enhancing properties on the action of hydrolytic enzymes, LOOS1 represents a potential additive in the production of fermentable sugars from lignocellulose.

In vitro antagonism of Thielaviopsis paradoxa by Trichoderma longibrachiatum.

Science.gov (United States)

Sánchez, Vladimir; Rebolledo, Oscar; Picaso, Rosa M; Cárdenas, Elizabeth; Córdova, Jesús; González, Orfil; Samuels, Gary J

2007-01-01

Seventy-nine Trichoderma strains were isolated from soil taken from 28 commercial plantations of Agave tequilana cv. 'Azul' in the State of Jalisco, Mexico. Nine of these isolates produced nonvolatile metabolites that completely inhibited the growth of Thielaviopsis paradoxa on potato dextrose agar plates. These isolates were identified as Trichoderma longibrachiatum on the basis of their morphology and DNA sequence analysis of two genes (ITS rDNA and translation elongation factor EF-1alpha). Mycoparasitism of Th. paradoxa by T. longibrachiatum strains in dual cultures was examined by scanning electron microscopy. The Trichoderma hyphae grew alongside the Th. paradoxa hyphae, but penetration of Thielaviopsis hyphae by Trichoderma was no apparent. Aleurioconidia of Th. paradoxa were parasitized by Trichoderma. Both hyphae and aleurioconidia of Th. paradoxa lost turgor pressure, wrinkled, collapsed and finally disintegrated. In liquid cultures, all nine Trichoderma isolates produced proteases, beta-1,3-glucanases and chitinases that would be responsible for the degradation of Thielaviopsis hyphae. These results demonstrate that the modes of action of T. longibrachiatum involved against Th. paradoxa in vitro experiments are mycoparasitism and the production of nonvolatile toxic metabolites.

Antioxidant potency of white (Brassica oleracea L. var. capitata) and Chinese (Brassica rapa L. var. pekinensis (Lour.)) cabbage: The influence of development stage, cultivar choice and seed selection

Czech Academy of Sciences Publication Activity Database

Šamec, D.; Piljac-Žegarac, J.; Bogovic, M.; Habjanic, K.; Grúz, Jiří

2011-01-01

Roč. 128, č. 2 (2011), s. 78-83 ISSN 0304-4238 R&D Projects: GA AV ČR KAN200380801; GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Antimicrobial activity * Antioxidant capacity * Brassica oleracea L. var. capitata * rapa L. var. pekinensis Lour * Cabbage Subject RIV: EF - Botanics Impact factor: 1.527, year: 2011

Influence of beetroot (Beta vulgaris var. cruenta) on mice leukocytes increase

OpenAIRE

Amaro, Jony

2014-01-01

Background: Beetroot is a flavonoid-containing Mediterranean plant used for food and medicinal purposes. Objectives: To determine the influence of Beta vulgaris var. cruenta extract consumption in increasing albino mice leukocytes. Design: Experimental study. Setting: School N° 1182 bioterium. Biologic material: Twenty male Balb/c albino mice weighing 24 g average. Interventions: Two groups of ten mice each were formed; the experimental group received Beta vulgaris var. cruenta extract at 250...

[Content and distribution of active components in cultivated and wild Taxus chinensis var. mairei plants].

Science.gov (United States)

Yu, Shao-Shuai; Sun, Qi-Wu; Zhang, Xiao-Ping; Tian, Sheng-Ni; Bo, Pei-Lei

2012-10-01

Taxus chinensis var. mairei is an endemic and endangered plant species in China. The resources of T. chinensis var. mairei have been excessively exploited due to its anti-cancer potential, accordingly, the extant T. chinensis var. mairei population is decreasing. In this paper, ultrasonic extraction and HPLC were adopted to determine the contents of active components paclitaxel, 7-xylosyltaxol and cephalomannine in cultivated and wild T. chinensis var. mairei plants, with the content distribution of these components in different parts of the plants having grown for different years and at different slope aspects investigated. There existed obvious differences in the contents of these active components between cultivated and wild T. chinensis var. mairei plants. The paclitaxel content in the wild plants was about 0.78 times more than that in the cultivated plants, whereas the 7-xylosyltaxol and cephalomannine contents were slishtly higher in the cultivated plants. The differences in the three active components contents between different parts and tree canopies of the plants were notable, being higher in barks and upper tree canopies. Four-year old plants had comparatively higher contents of paclitaxel, 7-xylosyltaxol and cephalomannine (0.08, 0.91 and 0.32 mg x g(-1), respectively), and the plants growing at sunny slope had higher contents of the three active components, with significant differences in the paclitaxel and 7-xylosyltaxol contents and unapparent difference in the cephalomannine content of the plants at shady slope. It was suggested that the accumulation of the three active components in T. chinensis var. mairei plants were closely related to the sunshine conditions. To appropriately increase the sunshine during the artificial cultivation of T. chinensis var. mairei would be beneficial to the accumulation of the three active components in T. chinensis var. mairei plants.

Scleria neesii Kunth var. gadchiroliensis (Cyperaceae, a New Variety from Central India

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Milind M. Sardesai

2015-12-01

Full Text Available A new variety of Scleria P. J. Bergius (Cyperaceae S. neesii Kunth var. gadchiroliensis from Central India is described here with description, line-drawing, photographic illustration and notes. It resembles with S. neesii Kunth var. neesii in overall morphology but differs in having milky white nuts covered with ribbon like hairs on distinct stalk.

Hydrophobic modification of cellulose isolated from Agave angustifolia fibre by graft copolymerisation using methyl methacrylate.

Science.gov (United States)

Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan; Mohamed, Faizal

2015-07-10

Graft copolymerisation of methyl methacrylate (MMA) onto Agave angustifolia was conducted with ceric ammonium nitrate (CAN) as the redox initiator. The maximum grafting efficiency was observed at CAN and MMA concentrations of 0.91 × 10(-3) and 5.63 × 10(-2)M, respectively, at 45°C for 3h reaction time. Four characteristic peaks at 2995, 1738, 1440, and 845 cm(-1), attributed to PMMA, were found in the IR spectrum of grafted cellulose. The crystallinity index dropped from 0.74 to 0.46, while the thermal stability improved upon grafting. The water contact angle increased with grafting yield, indicating increased hydrophobicity of cellulose. SEM images showed the grafted cellulose to be enlarged and rougher. The changes in the physical nature of PMMA-grafted cellulose can be attributed to the PMMA grafting in the amorphous regions of cellulose, causing it to expand at the expense of the crystalline component. Copyright © 2015 Elsevier Ltd. All rights reserved.

Utilizing nanobody technology to target non-immunodominant domains of VAR2CSA.

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Sisse B Ditlev

Full Text Available Placental malaria is a major health problem for both pregnant women and their fetuses in malaria endemic regions. It is triggered by the accumulation of Plasmodium falciparum-infected erythrocytes (IE in the intervillous spaces of the placenta and is associated with foetal growth restriction and maternal anemia. IE accumulation is supported by the binding of the parasite-expressed protein VAR2CSA to placental chondroitin sulfate A (CSA. Defining specific CSA-binding epitopes of VAR2CSA, against which to target the immune response, is essential for the development of a vaccine aimed at blocking IE adhesion. However, the development of a VAR2CSA adhesion-blocking vaccine remains challenging due to (i the large size of VAR2CSA and (ii the extensive immune selection for polymorphisms and thereby non-neutralizing B-cell epitopes. Camelid heavy-chain-only antibodies (HcAbs are known to target epitopes that are less immunogenic to classical IgG and, due to their small size and protruding antigen-binding loop, able to reach and recognize cryptic, conformational epitopes which are inaccessible to conventional antibodies. The variable heavy chain (VHH domain is the antigen-binding site of camelid HcAbs, the so called Nanobody, which represents the smallest known (15 kDa intact, native antigen-binding fragment. In this study, we have used the Nanobody technology, an approach new to malaria research, to generate small and functional antibody fragments recognizing unique epitopes broadly distributed on VAR2CSA.

Controlling Kuka Industrial Robots : Flexible Communication Interface JOpenShowVar.

OpenAIRE

Sanfilippo, Filippo; Hatledal, Lars Ivar; Zhang, Houxiang; Fago, Massimiliano; Pettersen, Kristin Ytterstad

2015-01-01

JOpenShowVar is a Java open-source cross-platform communication interface to Kuka industrial robots. This novel interface allows for read-write use of the controlled manipulator variables and data structures. JOpenShowVar, which is compatible with all the Kuka industrial robots that use KUKA Robot Controller version 4 (KR C4) and KUKA Robot Controller version 2 (KR C2), runs as a client on a remote computer connected with the Kuka controller via TCP/IP. Even though only soft real-time applica...

Working alliance inventory applied to virtual and augmented reality (WAI-VAR): psychometrics and therapeutic outcomes.

Science.gov (United States)

Miragall, Marta; Baños, Rosa M; Cebolla, Ausiàs; Botella, Cristina

2015-01-01

This study examines the psychometric properties of the Working Alliance Inventory-Short (WAI-S) adaptation to Virtual Reality (VR) and Augmented Reality (AR) therapies (WAI-VAR). The relationship between the therapeutic alliance (TA) with VR and AR and clinically significant change (CSC) is also explored. Seventy-five patients took part in this study (74.7% women, M age = 34.41). Fear of flying and adjustment disorder patients received VR therapy, and cockroach phobia patients received AR therapy. Psychometric properties, CSC, one-way ANOVA, Spearman's Correlations and Multiple Regression were calculated. The WAI-VAR showed a unidimensional structure, high internal consistency and adequate convergent validity. "Not changed" patients scored lower on the WAI-VAR than "improved" and "recovered" patients. Correlation between the WAI-VAR and CSC was moderate. The best fitting model for predicting CSC was a linear combination of the TA with therapist (WAI-S) and the TA with VR and AR (WAI-VAR), due to the latter variable slightly increased the percentage of variability accounted for in CSC. The WAI-VAR is the first validated instrument to measure the TA with VR and AR in research and clinical practice. This study reveals the importance of the quality of the TA with technologies in achieving positive outcomes in the therapy.

On Setting Day-Ahead Equity Trading Risk Limits: VaR Prediction at Market Close or Open?

Directory of Open Access Journals (Sweden)

Ana-Maria Fuertes

2016-09-01

Full Text Available This paper investigates the information content of the ex post overnight return for one-day-ahead equity Value-at-Risk (VaR forecasting. To do so, we deploy a univariate VaR modeling approach that constructs the forecast at market open and, accordingly, exploits the available overnight close-to-open price variation. The benchmark is the bivariate VaR modeling approach proposed by Ahoniemi et al. that constructs the forecast at the market close instead and, accordingly, it models separately the daytime and overnight return processes and their covariance. For a small cap portfolio, the bivariate VaR approach affords superior predictive ability than the ex post overnight VaR approach whereas for a large cap portfolio the results are reversed. The contrast indicates that price discovery at the market open is less efficient for small capitalization, thinly traded stocks.

Koolipärimuse kogumisest Noarootsis ja Vormsis 2006. aasta kevadel : Rootsi-Eesti lastenaljade kogumik Det var en ko och det var poängen / Piret Voolaid

Index Scriptorium Estoniae

Voolaid, Piret, 1971-

2007-01-01

Autor käsitleb artiklis Ahvenamaa Põhjamaade Instituudi (Nordens Institut på Åland) eestvedamisel korraldatud lastepärimuse projekti, mille käigus koguti koolipärimust Soomest Ahvenamaalt ja Rootsist Gotlandilt ning Eestist endistelt rannarootsi aladelt. Kogutu põhjal ilmus rootsikeelne antoloogiline naljakogumik Det var en ko och det var poängen. Artiklis keskendutakse välitööde kogumismetoodikale ja tulemustele Eestis. Välitööd toimusid Noarootsi Koolis ja Vormsi Põhikoolis

Penetration, Post-penetration Development, and Reproduction of Meloidogyne incognita on Cucumis melo var. texanus.

Science.gov (United States)

Faske, T R

2013-03-01

Cucumis melo var. texanus, a wild melon commonly found in the southern United States and two accessions, Burleson Co. and MX 1230, expressed resistance to Meloidogyne incognita in preliminary experiments. To characterize the mechanism of resistance, we evaluated root penetration, post-penetration development, reproduction, and emigration of M. incognita on these two accessions of C. melo var. texanus. Additionally, we evaluated 22 accessions of C. melo var. texanus for their reaction against M. incognita in a greenhouse experiment. Fewer (P ≤ 0.05) J2 penetrated the root system of C. melo var. texanus accessions (Burleson Co. and MX 1230) and C. metuliferus (PI 482452) (resistant control), 7 days after inoculation (DAI) than in C. melo 'Hales Best Jumbo' (susceptible control). A delayed (P ≤ 0.05) rate of nematode development was observed at 7, 14, and 21 DAI that contributed to lower (P ≤ 0.05) egg production on both accessions and C. metuliferus compared with C. melo. Though J2 emigration was observed on all Cucumis genotypes a higher (P ≤ 0.05) rate of J2 emigration was observed from 3 to 6 DAI on accession Burleson Co. and C. metuliferus than on C. melo. The 22 accessions of C. melo var. texanus varied relative to their reaction to M. incognita with eight supporting similar levels of nematode reproduction to that of C. metuliferus. Cucumis melo var. texanus may be a useful source of resistance against root-knot nematode in melon.

INDUCING RESISTANCE IN COTTON AGAINST COLLETOTRICHUM GOSSYPII VAR. CEPHALOSPORIOIDES WITH ESSENTIAL OILS

Directory of Open Access Journals (Sweden)

B. T. Santos

2016-11-01

Full Text Available This study aimed to evaluate the potential of essential oils of rosemary (Rosmarinus officinalis, baccharis (Baccharis trimera, lemon grass (Cymbopogon citratus, basil (Ocimum basilicum and eucalyptus (Corymbia citriodora in inducing resistance in cotton plants against C. gossypii var. cephalosporioides. The inductive effect of the essential oils was evaluated in plants growing in pots in the environment, which were treated with 1% essential oil at 47 days of age. 24 hours after elicitor treatment the plants were inoculated with a suspension of 1.5 x 105 conidia mL-1 of C. gossypii var. cephalosporioides. Five evaluations were performed disease and calculated the area under the disease progress curve. All essential oils showed potential for inducing resistance against cotton C. gossypii var. cephalosporioides.

Application of superconducting coils to VAR control in electric power systems: a proposal

International Nuclear Information System (INIS)

Boenig, H.J.; Hassenzahl, W.V.

1979-11-01

During the last eight years, static VAR-control systems with thyristor-controlled, room-temperature reactors have been used in electrical systems for voltage control and system stabilization. In this proposal, we describe a new static VAR-control system that uses an asymmetrically controlled Graetz bridge and a superconducting dc coil. Preliminary studies indicate that the proposed system will have lower overall losses and that its capital cost and electrical characteristics are comparable to those of a conventional system. Three- and four-year programs for developing the electronic circuitry and superconducting coils for VAR control, culminating in the installation and testing of an approx. 40-MVAR system, are proposed

Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana

NARCIS (Netherlands)

Ji, X.

2014-01-01

Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana.

I studied numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and

Analysis of the main components of the aguamiel produced by the maguey-pulquero (Agave mapisaga) throughout the harvest period.

Science.gov (United States)

Ortiz-Basurto, Rosa Isela; Pourcelly, Gérald; Doco, Thierry; Williams, Pascale; Dornier, Manuel; Belleville, Marie-Pierre

2008-05-28

The main characteristics of the aguamiel (maguey-pulquero sap) during the harvest period of the Agave mapisaga plants were assessed to establish its stability through time and the industrial potential of its components. Only minor differences in aguamiel composition were detected among samples collected at different time points of the harvest period. The aguamiel analyzed contained 11.5 wt % of dry matter, which was composed mainly of sugars (75 wt %). Among these sugars, 10 wt % were fructo-oligosaccharides (FOS), which are known to be important in the food industry for their prebiotic properties. Other components include 0.3 wt % of free amino acids (with most essential amino acids and four neurotransmitters: GABA, GLY, GLX, and ASX), 3 wt % of proteins, and 3 wt % of ashes.

THE EFFECT OF FUMIGATION TREATMENT TOWARDS AGAVE CANTALA ROXB FIBRE STRENGTH AND MORPHOLOGY

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MUSA BONDARIS PALUNGAN

2017-05-01

Full Text Available The objective of this study is to reveal the morphology, physical properties and strength of the king pineapple leaf fibre (Agave Cantala Roxb after fumigation treatment. The king pineapple leaf fibres (KPLF before and after the fumigation treatment are then separated into groups. The fumigation treatment on KPLF is given in different durations, and the smoke comes from burning coconut shells. Before and after fumigation, the surface morphology, chemical content, and functional group character of KPLF were observed by SEM, XRD, and FTIR, respectively. While the physical characteristics were identified by measuring fibre density, moisture content and fibre strength were tested by a single fibre tensile strength test. The results show that chemical contents of KPLF were cellulose, hemicellulose and lignin, accounting for as much as 55.8%, 21.27%, and 7.66%, respectively. After fumigation, the KPLF surface morphology becomes rough and grooved, the fibre density increased, and the single fibre tensile strength increased notably at the base of the king pineapple leaf. With the tensile strength increase and a rough and grooved KPLF surface morphology due to fumigation, fumigated KPLF would have the potential to be used as a strengthened composite.

[Diversity and community structure of endophytic fungi from Taxus chinensis var. mairei].

Science.gov (United States)

2014-07-01

A total of 628 endophytic fungi were isolated from 480 tissue segments of needles and branches of Taxus chinensis var. mairei. According to morphological characteristics and ITS sequences, they represented 43 taxa in 28 genera, of which 10 Hyphomycetes, 20 Coelomycetes, 12 Ascomycetes and 1 unknown fungus. Phomopsis mali was confirmed as the dominant species. In accordance with relative frequency, Alternaria alternata, Aureobasidium pullulans, Colletotrichum boninense, C. gloeosporioides, Epicoccum nigrum , Fungal sp., Fusarium lateritium, Glomerella cingulata, Magnaporthales sp. , Nigrospora oryzae, Pestalotiopsis maculiformans, P. microspora, Peyronellaea glomerata and Xylaria sp. 1 were more common in T. chinensis var. mairei. T. chinensis var. mairei were severely infected by endophytic fungi. Endophytic fungi were found in 81 percent of plant tissues with a high diversity. Distribution ranges of endophytic fungi were influenced by tissue properties. The colonization rate, richness, diversity of endophytic fungi in needles were obviously lower than in branches, and kinds of endophytic fungi between branches were more similar than those in needles, thus endophytic fungi had tissue preference. In addition, tissue age influenced the community structure of endophytic fungi. The elder branch tissues were, the higher colonization rate, richness, diversity of endophytic fungi were. Systematic studying the diversity and community structure of endophytic fungi in T. chinensis var. mairei and clarifying their distribution regularity in plant tissues would offer basic data and scientific basis for their development and utilization. Discussing the presence of fungal pathogens in healthy plant tissues would be of positive significance for source protection of T. chinensis var. mairei.

Essays on Imperfect Knowledge Economics, Structural Change, and Persistence in the Cointegrated VAR Model

DEFF Research Database (Denmark)

Tabor, Morten Nyboe

2014-01-01

conrm the original intuition behind the attempt to combine IKE and the econometric approach based on the cointegrated VAR model, that the parameter-instability of IKE models could potentially be an important source of the persistence found empirically in estimated cointegrated VAR models...

Water Relations and Photosynthesis of a Desert CAM Plant, Agave deserti1

Science.gov (United States)

Nobel, Park S.

1976-01-01

The water relations and photosynthesis of Agave deserti Engelm., a plant exhibiting Crassulacean acid metabolism, were measured in the Colorado desert. Although no natural stomatal opening of A. deserti occurred in the summer of 1975, it could be induced by watering. The resistance for water vapor diffusion from a leaf (RWV) became less than 20 sec cm−1 when the soil water potential at 10 cm became greater than −3 bars, as would occur after a 7-mm rainfall. As a consequence of its shallow root system (mean depth of 8 cm), A. deserti responded rapidly to the infrequent rains, and the succulent nature of its leaves allowed stomatal opening to continue for up to 8 days after the soil became drier than the plant. When the leaf temperature at night was increased from 5 to 20 C, RWV increased 5-fold, emphasizing the importance of cool nighttime temperatures for gas exchange by this plant. Although most CO2 uptake occurred at night, a secondary light-dependent rise in CO2 influx generally occurred after dawn. The transpiration ratio (mass of water transpired/mass of CO2 fixed) had extremely low values of 18 for a winter day, and approximately 25 for an entire year. PMID:16659721

[A survey on ecological environment of wild Adiantum reniforme var. sinense in Three Gorges Reservoir region].

Science.gov (United States)

Xie, Zhong-de; Jia, Han; Fu, Shao-Zhi; Gao, Wen-Yuan; Zhang, Zhi-Wei; Sun, Wei

2017-11-01

The study aims at investigating the ecological environment Adiantum reniforme var. sinense of in Three Gorges Reservoir region, and providing a reference basis for the protection of resources and artificial cultivation of A. reniforme var. sinense. By using the method of investigation, field survey and experimental analysis, the vegetation, natural geographical environment, climate, soil nutrients of A. reniforme var. sinense were studied and analyzed. The survey found that A. reniforme var. sinense distribution area reduced fast in Three Gorges region, a lot of distribution has diminished and vanished due to excessive digging, currently only in 3 towns of Wanzhou there exist 4 wild distribution areas. The growth of A. reniforme var. sinense needs an environment with low altitude, steep slope and thin soil, northeast slope, canopy height and warm and humid climate characteristics, and the soil in distribution has the characteristics of high organic matter, available nitrogen, available potassium, and low available phosphorus content. Copyright© by the Chinese Pharmaceutical Association.

Potential for wind extraction from 4D-Var assimilation of aerosols and moisture

Science.gov (United States)

Zaplotnik, Žiga; Žagar, Nedjeljka

2017-04-01

We discuss the potential of the four-dimensional variational data assimilation (4D-Var) to retrieve the unobserved wind field from observations of atmospheric tracers and the mass field through internal model dynamics and the multivariate relationships in the background-error term for 4D-Var. The presence of non-linear moist dynamics makes the wind retrieval from tracers very difficult. On the other hand, it has been shown that moisture observations strongly influence both tropical and mid-latitude wind field in 4D-Var. We present an intermediate complexity model that describes nonlinear interactions between the wind, temperature, aerosols and moisture including their sinks and sources in the framework of the so-called first baroclinic mode atmosphere envisaged by A. Gill. Aerosol physical processes, which are included in the model, are the non-linear advection, diffusion and sources and sinks that exist as dry and wet deposition and diffusion. Precipitation is parametrized according to the Betts-Miller scheme. The control vector for 4D-Var includes aerosols, moisture and the three dynamical variables. The former is analysed univariately whereas wind field and mass field are analysed in a multivariate fashion taking into account quasi-geostrophic and unbalanced dynamics. The OSSE type of studies are performed for the tropical region to assess the ability of 4D-Var to extract wind-field information from the time series of observations of tracers as a function of the flow nonlinearity, the observations density and the length of the assimilation window (12 hours and 24 hours), in dry and moist environment. Results show that the 4D-Var assimilation of aerosols and temperature data is beneficial for the wind analysis with analysis errors strongly dependent on the moist processes and reliable background-error covariances.

[Investigation on Main Cultivation of Astragalus membranaceus var. mongholicus and Commercial Specifications Grades].

Science.gov (United States)

Zhang, He-ting; Wang, Jian; Cheng, Ming-en; Duan, Hai-yan; Peng, Hua-sheng

2015-12-01

To investigate the main cultivation areas of Astragalus membranaceus var. mongholicus, and to clarify its present cultivation status and commercial specification grades. Astragalus membranaceus var. mongholicus cultivated in Hunyuan and Ying County of Shanxi, Longxi, Weiyuan and Min County of Gansu and Wuchuan, Guyang and Chifeng of Inner Mongolia were investigated, including their ecological environment, cultivation history and present situation, harvesting and processing as well as commercial specification grades. The cultivation methods of Astragalus membranaceus var. mongholicus changed greatly in the main cultivation areas. In Gansu and Inner Mongolia, the current major cultivation method was 2 - 3 years of seedling transplantation method, while the 3 - 5 years of seed-directly-sowed method in Inner Mongolia had been almost abandoned, and the 6 - 8 years of mountain direct seeding method was still in application in Hunyuan county of Shanxi province. On the other hand, the harvest method of Astragalus membranaceus var. mongholicus had been gradually changed from manual harvesting in ancient times to the current mechanical harvesting although the latter method did more damage to environment of cultivation areas and the resource of Astragalus membranaceus var. mongholicus in regions Hunyuan county of Shanxi. Through investigating the processing methods of Astragalus membranaceus var. mongholicus in different cultivation areas, it was found that processing method varied from area to area, and no unified specifications had been formulated on processing methods in market. In addition, the current processing method was too complicated in processing the slices of prepared Astragali Radix and most were self processing by farmers themselves, creating market disorders. Moreover, the Astragali Radix products were basically without grading classification but sold as bulk cargo. It is urgent to unify the specifications and grades of Astragali Radix product, and standardize

Anatomical element localization by EDXS in Grevillea exul var. exul under nickel stress

International Nuclear Information System (INIS)

Rabier, J.; Laffont-Schwob, I.; Notonier, R.; Fogliani, B.; Bouraima-Madjebi, S.

2008-01-01

Grevillea exul var. exul, an endemic serpentinic Proteaceae of New Caledonia, was chosen to study the spatial distribution of Ni because this species supports strong content of metals, which can allow important absorptions thus detectable by microanalysis. Fine transversal sections of axenic G. exul var. exul plants grown during 15 days on nickel sulphate medium were examined by EDXS microanalysis. It showed that in Ni treated plants, Ni was concentrated mostly in the phloem compared to the xylem and the epidermis, either in roots or in the basal part of the stems and was mostly in the epidermis in the upper part of the stems and not detectable in the leaves. This metal took the place of P and K in the treated plants whereas the localization of these macroelements was quite uniform in control sections. We assume that a mechanism of phloem loading is implicated to restrict Ni accumulation in G. exul var. exul. - Ni resistance mechanism in Grevillea exul var. exul plants depends on a basipetal export mechanism

Anatomical element localization by EDXS in Grevillea exul var. exul under nickel stress

Energy Technology Data Exchange (ETDEWEB)

Rabier, J. [Equipe Biomarqueurs et Bioindicateurs Environnementaux, Institut Mediterraneen d' Ecologie et de Paleoecologie, UMR CNRS 6116, Universite de Provence, Case 17, 3 Place Victor Hugo, 13331 Marseille Cedex 3 (France)], E-mail: Jacques.Rabier@univ-provence.fr; Laffont-Schwob, I. [Equipe Biomarqueurs et Bioindicateurs Environnementaux, Institut Mediterraneen d' Ecologie et de Paleoecologie, UMR CNRS 6116, Universite de Provence, Case 17, 3 Place Victor Hugo, 13331 Marseille Cedex 3 (France)], E-mail: Isabelle.Schwob@univ-provence.fr; Notonier, R. [Service commun de microscopie electronique, Universite de Provence, Case 76, 3 Place Victor Hugo, 13331 Marseille Cedex 3 (France)], E-mail: Roger.Notonier@univ-provence.fr; Fogliani, B. [MABioM, Universite de la Nouvelle-Caledonie, BP R4, 98847 Noumea, New Caledonia (France)], E-mail: bfoglian@univ-nc.nc; Bouraima-Madjebi, S. [MABioM, Universite de la Nouvelle-Caledonie, BP R4, 98847 Noumea, New Caledonia (France)], E-mail: bouraima@univ-nc.nc

2008-12-15

Grevillea exul var. exul, an endemic serpentinic Proteaceae of New Caledonia, was chosen to study the spatial distribution of Ni because this species supports strong content of metals, which can allow important absorptions thus detectable by microanalysis. Fine transversal sections of axenic G. exul var. exul plants grown during 15 days on nickel sulphate medium were examined by EDXS microanalysis. It showed that in Ni treated plants, Ni was concentrated mostly in the phloem compared to the xylem and the epidermis, either in roots or in the basal part of the stems and was mostly in the epidermis in the upper part of the stems and not detectable in the leaves. This metal took the place of P and K in the treated plants whereas the localization of these macroelements was quite uniform in control sections. We assume that a mechanism of phloem loading is implicated to restrict Ni accumulation in G. exul var. exul. - Ni resistance mechanism in Grevillea exul var. exul plants depends on a basipetal export mechanism.

Forecasting VaR and ES of stock index portfolio: A Vine copula method

Science.gov (United States)

Zhang, Bangzheng; Wei, Yu; Yu, Jiang; Lai, Xiaodong; Peng, Zhenfeng

2014-12-01

Risk measurement has both theoretical and practical significance in risk management. Using daily sample of 10 international stock indices, firstly this paper models the internal structures among different stock markets with C-Vine, D-Vine and R-Vine copula models. Secondly, the Value-at-Risk (VaR) and Expected Shortfall (ES) of the international stock markets portfolio are forecasted using Monte Carlo method based on the estimated dependence of different Vine copulas. Finally, the accuracy of VaR and ES measurements obtained from different statistical models are evaluated by UC, IND, CC and Posterior analysis. The empirical results show that the VaR forecasts at the quantile levels of 0.9, 0.95, 0.975 and 0.99 with three kinds of Vine copula models are sufficiently accurate. Several traditional methods, such as historical simulation, mean-variance and DCC-GARCH models, fail to pass the CC backtesting. The Vine copula methods can accurately forecast the ES of the portfolio on the base of VaR measurement, and D-Vine copula model is superior to other Vine copulas.

Abelmoschus manihot var. pungens (Roxburgh Hochreutiner (Malvaceae, A Newly Naturalized Plant in Taiwan

Directory of Open Access Journals (Sweden)

Szu-I Hsieh

2013-06-01

Full Text Available Abelmoschus manihot var. pungens (Roxburgh Hochreutiner is naturalized in abandoned land of central Taiwan. The distinguished characteristics of A. manihot var. pungens include the ovate-lanceolate epicalyx lobes, distinct prickly hairs all over the plant, and even over the margins of its epicalyx lobes. Descriptions, line drawings and photos of this species are provided.

[Study on quality standard of Mucuna pruriens var. utilis].

Science.gov (United States)

Wu, Shi-Hong; Jiang, Wei-Zhe; Lv, Li; Wu, Ling-Ling; Lv, Cong; Shi, Xiao-Xia; Su, Gui-Liang

2009-03-01

To provide scientific basis for the utilization and development of Mucuna pruriens var. utilis by establishing its quality control standard. The bioactive constituents were analyzed by TLC and HPLC. Moisture, ash and the extracts of Mucuna pruriens var. utilis were all determined. The TLC spots of levodopa had similar color with the control group at the same position. The results of HPLC quantitative analysis showed that the linear range of levodopa was 26.45 to approximately 132.25 microg/mL, r = 0.9992, and the average recovery rate was 103.8%, RSD = 1.85%. This method is convenient, accurate, reliable with good reproducibility, so it can be used to establish quality standard for the medicinal material.

A Stochastic Dominance Approach to the Basel III Dilemma: Expected Shortfall or VaR?

NARCIS (Netherlands)

C-L. Chang (Chia-Lin); J.A. Jiménez-Martín (Juan-Ángel); E. Maasoumi (Esfandiar); M.J. McAleer (Michael); T. Pérez-Amaral (Teodosio)

2015-01-01

markdownabstract__Abstract__ The Basel Committee on Banking Supervision (BCBS) (2013) recently proposed shifting the quantitative risk metrics system from Value-at-Risk (VaR) to Expected Shortfall (ES). The BCBS (2013) noted that “a number of weaknesses have been identified with using VaR for

Genetic analisys of a cross of gaillon (Brassica oleracea var. alboglabra with cauliflower (B.oleracea var. botrytis

Directory of Open Access Journals (Sweden)

Vanessa B.M.G. Spini

2000-03-01

Full Text Available The cauliflower (Brassica oleracea var. botrytis is an annual vegetable cultivated in Southern and Southwestern Brazil with limited production in the Northeast and Centralwest. A variety of Chinese kale, "kaai laan" or "gaillon" (Brassica oleracea var. alboglabra, produces seeds at high temperatures and therefore can do so in North and Northeastern Brazil. Gaillon and cauliflower were crossed 55 times using 10 gaillon plants as mothers and 4 cauliflower plants as pollen donors. From these crosses, in the F2 generation, 612 plants with inflorescence like gaillon and 48 plants with inflorescence like cauliflower were obtained, in a proportion similar to 15:1, implying that 2 pairs of genes entered into formation of the cauliflower inflorescence type. In order to study flower color, 339 plants were analyzed: 274 presented white flowers and 65, yellow flowers, denoting that this caracter is determined by 1 pair of genes, white being dominant over yellow; white flowers had a slighly higher adaptive value in our population. The characteristic waxy leaf showed a proportion of 3 waxy plants for 1 not waxy, indicating the action of one pair of genes.A couve-flor (Brassica oleracea var. botrytis é um vegetal anual e tem seu cultivo no Brasil limitado às regiões Sul e Sudeste, com pequena produção no Nordeste e Centro-Oeste. Uma variedade de couve da China, "kaai laan" ou "gaillon" (Brassica oleracea var. alboglabra, produz sementes em altas temperaturas e, portanto, é apta a produzir sementes no Norte e Nordeste do Brasil. Gaillon e couve-flor foram cruzados. Foram feitos 55 cruzamentos usando 10 plantas de gaillon como mãe e 4 plantas de couve-flor como doadores de pólen. Desses cruzamentos, na geração F2, 612 plantas com inflorescência tipo gaillon e 48 plantas com inflorescência tipo couve-flor foram obtidas, em proporção similar a 15:1, demonstrando que 2 pares de genes estão envolvidos na formação da inflorescência em couve

Larvicidal activity of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus.

Science.gov (United States)

DE Lara, Ana Paula DE Souza Stori; Lorenzon, Lucas Bigolin; Vianna, Ana Muñoz; Santos, Francisco Denis Souza; Pinto, Luciano Silva; Aires Berne, Maria Elisabeth; Leite, Fábio Pereira Leivas

2016-10-01

Effective control of gastrointestinal parasites is necessary in sheep production. The development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. Biological control strategies present an alternative to this problem. In the current study, we tested the larvicidal effects of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus larvae. Bacterial suspensions [2 × 108 colony-forming units (CFU) g-1 of the feces] of B. thuringiensis var. israelensis and recombinant Escherichia coli expressing Cry11Aa toxin were added to naturally H. contortus egg-contaminated feces. The larvae were quantified, and significant reductions of 62 and 81% (P var. israelensis and recombinant E. coli expressing Cry11Aa toxin were then orally administered to lambs naturally infected with H. contortus. Twelve hours after administration, feces were collected and submitted to coprocultures. Significant larvae reductions (P var. israelensis is a promising new class of biological anthelmintics for treating sheep against H. contortus.

Sequential enzymatic saccharification and fermentation of ionic liquid and organosolv pretreated agave bagasse for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Pérez-Pimienta, Jose A. [Univ. Autonoma de Nayarit, Tepic (Mexico); Vargas-Tah, Alejandra [Univ. Nacional Autonoma de Mexico (UNAM), Cuernavaca (Mexico).; López-Ortega, Karla M. [Univ. Autonoma de Nayarit, Tepic (Mexico); Medina-López, Yessenia N. [Univ. Autonoma de Nayarit, Tepic (Mexico); Mendoza-Pérez, Jorge A. [Inst. Politecnico Nacional (IPN), Mexico City (Mexico); Avila, Sayeny [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Singh, Seema [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Simmons, Blake A. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Loaces, Inés [Univ. Nacional Autonoma de Mexico (UNAM), Cuernavaca (Mexico).; Martinez, Alfredo [Univ. Nacional Autonoma de Mexico (UNAM), Cuernavaca (Mexico).

2016-11-16

Agave bagasse (AGB) has gained recognition as a drought-tolerant biofuel feedstock with high productivity in semiarid regions. A comparative analysis of ionic liquid (IL) and organosolv (OV) pretreatment technologies in AGB was performed using a sequential enzymatic saccharification and fermentation (SESF) strategy with cellulolytic enzymes and the ethanologenic Escherichia coli strain MS04. After pretreatment, 86% of xylan and 45% of lignin were removed from OV-AGB, whereas IL-AGB reduced lignin content by 28% and xylan by 50% when compared to the untreated biomass. High glucan ( > 90%) and xylan ( > 83%) conversion was obtained with both pretreated samples. During the fermentation stage (48 h), 12.1 and 12.7 kg of ethanol were produced per 100 kg of untreated AGB for IL and OV, respectively. These comparative analyses showed the advantages of SESF using IL and OV in a biorefinery configuration where a better understanding of AGB recalcitrance is key for future applications.

Efeito da omissão de macronutrientes em sisal Macronutrients deficiency on sisal (Agave sisalana perr.

Directory of Open Access Journals (Sweden)

Antonio Luiz de Barbos Salgado

1982-01-01

Full Text Available Plantas de sisal (Agave sisalana Perr. foram cultivadas em casa de vegetação, em vasos contendo areia lavada e irrigados com solução nutritiva completa e com soluções nutritivas com a omissão de cada macronutriente. As plantas mostraram, na ausência de cada nutriente, os sintomas típicos de sua carência, relacionados com baixos teores do respectivo elemento nas folhas, e redução no seu crescimento e desenvolvimento.Sisal plants were cultivated in washed sand during twenty-one months. The plants were irrigated with complete nutrient solution and solutions with absence of each macronutrient (N, P, K, Ca, Mg e S. The plants, in the absence of each macronutrient, showed typical symptoms which were related to the low level of the respective element in the leaf. The growing of the leaves was reduced by the absence of the macronutrients.

Characterization of the antigenicity of Cpl1, a surface protein of Cryptococcus neoformans var. neoformans.

Science.gov (United States)

Cai, Jian-Piao; Liu, Ling-Li; To, Kelvin K W; Lau, Candy C Y; Woo, Patrick C Y; Lau, Susanna K P; Guo, Yong-Hui; Ngan, Antonio H Y; Che, Xiao-Yan; Yuen, Kwok-Yung

2015-01-01

Cryptococcus neoformans var. neoformans is an important fungal pathogen. The capsule is a well established virulence factor and a target site for diagnostic tests. The CPL1 gene is required for capsular formation and virulence. The protein product Cpl1 has been proposed to be a secreted protein, but the characteristics of this protein have not been reported. Here we sought to characterize Cpl1. Phylogenetic analysis showed that the Cpl1 of C. neoformans var. neoformans and the Cpl1 orthologs identified in C. neoformans var. grubii and C. gattii formed a distinct cluster among related fungi; while the putative ortholog found in Trichosporon asahii was distantly related to the Cryptococcus cluster. We expressed Cpl1 abundantly as a secreted His-tagged protein in Pichia pastoris. The protein was used to immunize guinea pigs and rabbits for high titer mono-specific polyclonal antibody that was shown to be highly specific against the cell wall of C. neoformans var. neoformans and did not cross react with C. gattii, T. asahii, Aspergillus spp., Candida spp. and Penicillium spp. Using the anti-Cpl1 antibody, we detected Cpl1 protein in the fresh culture supernatant of C. neoformans var. neoformans and we showed by immunostaining that the Cpl1 protein was located on the surface. The Cpl1 protein is a specific surface protein of C. neoformans var. neoformans. © 2015 by The Mycological Society of America.

Carbon dioxide evolution and temperature factors in early growth of plastic mulched plants. [Cucumis melo L. var. reticulatus; Lactuca sativa L. var. crispa

Energy Technology Data Exchange (ETDEWEB)

Betts, C.; Ruf, R.H. Jr.

1966-01-01

Cantaloupe (Cucumis melo L. var. reticulatus) and lettuce (Lactuca sativa L. var. crispa) were grown in the greenhouse in redwood boxes with bare and plastic mulched soil. Soil temperature in the bare boxes was equated to the plastic mulch with buried temperature coils. Bottled CO/sub 2/ was used to bring the concentration around the plants in bare soil up to the concentration around mulched plants. Carbon dioxide was sampled in leaf canopy. The temperature treatment increased the yields of the bare soil so that they were comparable to those of the plastic mulched soil. Yields from the soil with the auxiliary CO/sub 2/ were lower than those of the mulched treatment.

Bioactivity-guided isolation of antioxidant triterpenoids from Betula platyphylla var. japonica bark.

Science.gov (United States)

Eom, Hee Jeong; Kang, Hee Rae; Kim, Ho Kyong; Jung, Eun Bee; Park, Hyun Bong; Kang, Ki Sung; Kim, Ki Hyun

2016-06-01

The bark of Betula platyphylla var. japonica (Betulaceae) has been used to treat pneumonia, choloplania, nephritis, and chronic bronchitis. This study aimed to investigate the bioactive chemical constituents of the bark of B. platyphylla var. japonica. A bioassay-guided fractionation and chemical investigation of the bark of B. platyphylla var. japonica resulted in the isolation and identification of a new lupane-type triterpene, 27-hydroxybetunolic acid (1), along with 18 known triterpenoids (2-19). The structure of the new compound (1) was elucidated on the basis of 1D and 2D NMR spectroscopic data analysis as well as HR-ESIMS. Among the known compounds, chilianthin B (17), chilianthin C (18), and chilianthin A (19) were triterpene-lignan esters, which are rarely found in nature. Compounds 4, 6, 7, 17, 18, and 19 showed significant antioxidant activities with IC50 values in the range 4.48-43.02μM in a DPPH radical-scavenging assay. However, no compound showed significant inhibition of acetylcholine esterase (AChE). Unfortunately, the new compound (1) exhibited no significance in both biological activities. This study strongly suggests that B. platyphylla var. japonica bark is a potential source of natural antioxidants for use in pharmaceuticals and functional foods. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of Water Extracts from Rhizosphere Soil of Cultivated Astragalus membranaceus var. mongholicus on It's Seed Germination and Physiological Characteristics].

Science.gov (United States)

Lang, Duo-yong; Fu, Xue-yan; Rong, Jia-wang; Zhang, Xin-hui

2015-01-01

To explore the relationship between continuous cropping obstacle and autotoxicity of Astragalus membranaceus var. mongholicus. Distilled water(CK), water extracts of rhizosphere soil(50, 100, 200 and 400 mg/mL) were applied to test their effect on early growth and physiological characteristics of Astragalus membranaceus var. mongholicus. The water extracts from rhizospher soil of cultivated Astragalus membranaceus var. mongholicus significantly increased seedling emergence rate, root length and vigor index of Astragalus membranaceus var. mongholicus seedling when at the concentration of 100 mg/mL or below, however,there was no significant effect at 200 mg/mL or higher. The water extracts from rhizosphere soil of cultivated Astragalus membranaceus var. mongholicus significantly reduced the SOD activity in Astragalus membranaceus var. mongholicus seedling at 400 mg/mL and POD activity at 200 mg/mL and 400 mg/mL,while significantly increased the MDA content. Water extracts from Astragalus membranaceus var. mongholicus rhizosphere soil significantly affected Astragalus membranaceus var. mongholicus germination and seedling growth in a concentration-dependent manner, generally, low concentrations increased the SOD and POD activity which improved seed germination and seedling growth, while high concentrations caused cell membrane damage of the seedling.

Cryptococcus neoformans in the koala (Phascolarctos cinereus): colonization by C n. var. gattii and investigation of environmental sources.

Science.gov (United States)

Krockenberger, M B; Canfield, P J; Malik, R

2002-06-01

This study is the one in a series looking at the relationship among Cryptococcus neoformans var. gattii, koalas and the environment. The koala was used as a natural biological sampler in an attempt to understand the dynamics of C. neoformans var. gattii in Australian environments. Evidence of asymptomatic nasal and skin colonization for extended periods by large numbers of C. n. var. gattii was obtained and geographical factors assessed. The key finding was the ability of koalas to amplify numbers of C. n. var. gattii in certain environments. Koalas were not found to be obligatory for the survival of the organism in all environments. Geographical factors alone could not explain differing rates of nasal and skin colonization in koalas in different environments. A strong association between healthy koalas and C. n. var. gattii was confirmed and C n. var. gattii was isolated from novel sources, including the turpentine gum tree (Syncarpia glomulifera), tallowwood (Eucalyptus microcorys) and flooded gum (E. grandis). It seems likely that as yet undiscovered environmental sources of C. n. var. gattii exist in eastern Australia. Further investigation of host, environmental and organism factors integral to the hostpathogen relationship will assist an understanding of the progression from colonization to tissue invasion and cryptococcosis in all species.

Effect of antibiotics on Agave fourcroydes Lem in vitro propagation

Directory of Open Access Journals (Sweden)

Enildo Abreu

2016-01-01

Full Text Available High microbial contamination on henequen (Agave fourcroydes Lem in vitro propagation reduces its efficiency. This work aimed to determine the effect of the use of antibiotics in the control of bacterial contaminants of this culture. Bacterial contaminants were identified and their susceptibility to different antibiotics it were determined. The two best-acting antibiotics were added to the propagation medium and the number of explants contaminated with bacteria and necrotics was quantified. The antibiotic and concentration that did not cause phytotoxicity to the explants and where the lowest percentage of contamination was obtained it was used to continue the propagation of the plants. These were transferred to the acclimatization stage and at 30 days of culture the number of live plants and the number of roots per plant were quantified. In addition, the length of the roots (cm was measured and the leaf area was calculated. Micrococcus spp., Pseudomonas spp., Agrobacterium spp., Bacillus subtilis and Bacillus licheniformis were found. The antibiotics tested inhibited the in vitro growth of the isolated contaminants and the best results were obtained with Ticar and Cefotaxime. Added to the plant propagation medium, Ticar was phytotoxic over 50 mg l-1 and cefotaxime could be used at 100 mg l-1 without causing damage to the explants. The results showed that the plants that came from the culture medium with cefotaxime 100 mg l-1 showed a significant increase of the variables evaluated in the acclimatization stage.   Key words: betalactamic, henequen, micropropagation

Occurrence of pathotypes of Phoma medicaginis var. pinodella (Jones Boerema in the Olsztyn district

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Helena Furgał-Węgrzycka

2013-12-01

Full Text Available The causal agents of leaves and pods spot-pot of peas and field peas in the Olsztyn district was the fungus Phoma medicaginis var. pinodella. Investigated isolates of P. medicaginis var. pinodella differed by macroscopic and microscopic features. From diseases leaves and pods of peas and field peas obtained also saprophytic fungi among which Alternaria alternata, Botrytis cinerea, Cladosporium cladosporioides, Epicoccum purpurascens, Stemphylium botryosum, Sordaria fimicola and mycelia sterilia were dominated. In the study on the identification and distribution of pathotypes of P. medicaginis var. pinodella six pathotypes were identified among which pathotype 3 were dominated. The identified pathotypes differed by macroscopic and microscopic features.

Is Solanum ferox var. ferox (Solanaceae) extinct?

NARCIS (Netherlands)

Heiser, C.B.

2001-01-01

In 1995 I wrote letters to over 50 people (botanists, agricultural scientists, and former students of Indiana University) in south-eastern Asia trying to obtain a few seeds of Solanumferox L. var. ferox (S. involucratum Blume). I had over 25 replies, five of which included seeds, but none of the

Erasing the Epigenetic Memory and Beginning to Switch—The Onset of Antigenic Switching of var Genes in Plasmodium falciparum

Science.gov (United States)

Fastman, Yair; Noble, Robert; Recker, Mario; Dzikowski, Ron

2012-01-01

Antigenic variation in Plasmodium falciparum is regulated by transcriptional switches among members of the var gene family, each expressed in a mutually exclusive manner and encoding a different variant of the surface antigens collectively named PfEMP1. Antigenic switching starts when the first merozoites egress from the liver and begin their asexual proliferation within red blood cells. By erasing the epigenetic memory we created parasites with no var background, similar to merozoites that egress from the liver where no var gene is expressed. Creating a null-var background enabled us to investigate the onset of antigenic switches at the early phase of infection. At the onset of switching, var transcription pattern is heterogeneous with numerous genes transcribed at low levels including upsA vars, a subtype that was implicated in severe malaria, which are rarely activated in growing cultures. Analysis of subsequent in vitro switches shows that the probability of a gene to turn on or off is not associated with its chromosomal position or promoter type per se but on intrinsic properties of each gene. We concluded that var switching is determined by gene specific associated switch rates rather than general promoter type or locus associated switch rates. In addition, we show that fine tuned reduction in var transcription increases their switch rate, indicating that transcriptional perturbation can alter antigenic switching. PMID:22461905

[Effects of low-light stress on photosynthetic characteristics of Paris polyphylla var. chinensis in artificial domestication cultivation].

Science.gov (United States)

Zheng, Shun-lin; Tian, Meng-liang; Liu, Jin-liang; Zhao, Ting-ting; Zhang, Zhong

2014-09-01

To decide on the optimum artificial domestication cultivation light environment for Paris polyphylla var. chinensis through investigating the effect of light intensity on leaf's gas exchange parameters, photosynthetic parameters, light saturation point and compensation point of Paris polyphylla var. chinensis. Different low-light stress gradients' effect on the growth of Paris polyphylla var. chinensis was compared with no low-light stress treatment through calculating leaf's gas exchange parameters, photosynthetic parameters, light saturation point and compensation point, and then all these parameters were statistically analyzed. Light intensity had significant influence on the photosynthetic characteristics of Paris polyphylla var. chinensis. With the strengthening of the low-light stress, chlorophyll content, gas exchange parameters, photosynthetic parameters P., AQY and light saturation point all gradually increased at first, and then decreased. However, both photosynthetic parameters Rd and light compensation point firstly decreased and then rose again. These results showed that too strong or too weak light intensity affected the optimization of photosynthetic parameters of Paris polyphylla var. chinensis. The optimal illuminance for each parameter was not completely same, but they could all reach a relative ideal state when the shading ranges between 40% and 60%. However, photosynthetic parameters deteriorated rapidly when the shading surpass 80%. For artificially cultivating Paris polyphylla var. chinensis in Baoxing,Sichuan or the similar ecological region, shading 40%-60% is the optimal light environment, which can enhance the photosynthesis of Paris polyphylla var. chinensis and promote the accumulation of photosynthetic products.

Antidepressant-like Effect of Kaempferol and Quercitirin, Isolated from Opuntia ficus-indica var. saboten.

Science.gov (United States)

Park, Soo-Hyun; Sim, Yun-Beom; Han, Pyung-Lim; Lee, Jin-Koo; Suh, Hong-Won

2010-06-01

Opuntia ficus-indica var. saboten. is widely cultivated in Jeju Island (South Korea) for use in manufacture of health foods. This study described antidepressant effect of two flavonoids (kaempferol and quercitrin) isolated from the Opuntia ficus-indica var. saboten. The expression of the hypothalamic POMC mRNA or plasma β-endorphin levels were increased by extract of Opuntia ficus-indica var. saboten or its flavoniods administered orally. In addition, antidepressant activity was studied using tail suspension test (TST), forced swimming test (FST) and rota-rod test in chronically restraint immobilization stress group in mice. After restraint stress (2 hrs/day for 14 days), animals were kept in cage for 14 days without any further stress, bet with drugs. Mice were fed with a diet supplemented for 14 days and during the behavioral test period with kaempferol or quercitrin (30 mg/kg/day). POMC mRNA or plasma β-endorphin level was increased by extract of Opuntia ficus-indica var. saboten and its flavoniods. In addition, immobility time in TST and FST was significantly reduced by kaempferol or quercitrin. In rota-rod test, the time of permanence was maintained to the semblance of control group in turning at 15 rpm. Our results suggest that two flavonoids (kaempferol and quercitrin) isolated from the Opuntia ficus-indica var. saboten. show a potent antidepressant effect.

Antidepressant-like Effect of Kaempferol and Quercitirin, Isolated from Opuntia ficus-indica var. saboten

Science.gov (United States)

Park, Soo-Hyun; Sim, Yun-Beom; Han, Pyung-Lim; Lee, Jin-Koo

2010-01-01

Opuntia ficus-indica var. saboten. is widely cultivated in Jeju Island (South Korea) for use in manufacture of health foods. This study described antidepressant effect of two flavonoids (kaempferol and quercitrin) isolated from the Opuntia ficus-indica var. saboten. The expression of the hypothalamic POMC mRNA or plasma β-endorphin levels were increased by extract of Opuntia ficus-indica var. saboten or its flavoniods administered orally. In addition, antidepressant activity was studied using tail suspension test (TST), forced swimming test (FST) and rota-rod test in chronically restraint immobilization stress group in mice. After restraint stress (2 hrs/day for 14 days), animals were kept in cage for 14 days without any further stress, bet with drugs. Mice were fed with a diet supplemented for 14 days and during the behavioral test period with kaempferol or quercitrin (30 mg/kg/day). POMC mRNA or plasma β-endorphin level was increased by extract of Opuntia ficus-indica var. saboten and its flavoniods. In addition, immobility time in TST and FST was significantly reduced by kaempferol or quercitrin. In rota-rod test, the time of permanence was maintained to the semblance of control group in turning at 15 rpm. Our results suggest that two flavonoids (kaempferol and quercitrin) isolated from the Opuntia ficus-indica var. saboten. show a potent antidepressant effect. PMID:22110339

The cross-ecosystem impact of deer on an endangered submerged macrophyte, Ranunculus nipponicus var. submersus

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Hino Takafumi

2015-07-01

Full Text Available Macrophytes are a critical component of freshwater ecosystems and are often eaten by cervids. However, the impact of cervids on macrophytes is not well known. In this study, we investigated the effect of sika deer (Cervus nippon yesoensis on the endangered macrophyte Ranunculus nipponicus var. submersus in a spring stream in southwestern Hokkaido, Japan. We monitored the frequency of stream habitat use by deer by using sensor cameras in photography mode for four seasons. We also monitored deer feeding behavior on R. nipponicus var. submersus using sensor cameras in movie mode. To quantitatively evaluate the impact of deer on R. nipponicus var. submersus, we conducted a field experiment in which deer were excluded from part of the stream. We selected 10 pairs of adjacent patches of R. nipponicus var. submersus and set up exclosures covering one patch in each pair. We assessed the frequency of deer feeding and trampling on the control patches using the sensor cameras in photography mode and measured the mean macrophyte stem length in the exclosure and control patches every month for four seasons. To compare abiotic conditions between the exclosure and control patches, we investigated canopy openness, water depth, water temperature, electrical conductivity, pH, current velocity, and water quality at each patch during the growing season. The frequency of deer in the stream habitat was higher from spring to summer than in other seasons. Direct evidence of deer feeding behavior on R. nipponicus var. submersus was recorded using the sensor cameras. Deer often fed on and trampled on the control patches, particularly from spring to summer. The R. nipponicus var. submersus stem length was longer in the exclosure patches than in control patches (P 0.189. Stem growth of R. nipponicus var. submersus differed among seasons (P <0.001, and was low from winter to spring. In addition, exclosure and seasonality significantly affected stem length (P <0.001, and the

Probiotic Activity of Saccharomyces cerevisiae var. boulardii Against Human Pathogens

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Katarzyna Rajkowska

2012-01-01

Full Text Available Infectious diarrhoea is associated with a modification of the intestinal microflora and colonization of pathogenic bacteria. Tests were performed for seven probiotic yeast strains of Saccharomyces cerevisiae var. boulardii, designated for the prevention and treatment of diarrhoea. To check their possible effectiveness against diarrhoea of different etiologies, the activity against a variety of human pathogenic or opportunistic bacteria was investigated in vitro. In mixed cultures with S. cerevisiae var. boulardii, a statistically significant reduction was observed in the number of cells of Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus, by even 55.9 % in the case of L. monocytogenes compared with bacterial monocultures. The influence of yeasts was mostly associated with the shortening of the bacterial lag phase duration, more rapid achievement of the maximum growth rates, and a decrease by 4.4–57.1 % (L. monocytogenes, P. aeruginosa, or an increase by 1.4–70.6 % (Escherichia coli, Enterococcus faecalis, Salmonella Typhimurium in the exponential growth rates. Another issue included in the research was the ability of S. cerevisiae var. boulardii to bind pathogenic bacteria to its cell surface. Yeasts have shown binding capacity of E. coli, S. Typhimurium and additionally of S. aureus, Campylobacter jejuni and E. faecalis. However, no adhesion of L. monocytogenes and P. aeruginosa to the yeast cell wall was noted. The probiotic activity of S. cerevisiae var. boulardii against human pathogens is related to a decrease in the number of viable and active cells of bacteria and the binding capacity of yeasts. These processes may limit bacterial invasiveness and prevent bacterial adherence and translocation in the human intestines.

Determination of thermodynamic parameters of Cr(VI) adsorption from aqueous solution onto Agave lechuguilla biomass

Energy Technology Data Exchange (ETDEWEB)

Romero-Gonzalez, J. [Environmental Science and Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Peralta-Videa, J.R. [Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968 (United States); Rodriguez, E. [Environmental Science and Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Ramirez, S.L. [Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968 (United States); Gardea-Torresdey, J.L. [Environmental Science and Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States) and Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968 (United States)]. E-mail: jgardea@utep.edu

2005-04-15

The temperature dependence of the Cr(VI) bioadsorption and its possible reduction to Cr(III) by Agave lechuguilla biomass were studied. The experimental data obtained in batch experiments at different temperatures were fitted to the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. The adsorption equilibrium data fitted well with the Freundlich model. The average model parameters calculated from Freundlich's isotherms (adsorption capacity K{sub F} = 4 . 10{sup -2} mol . g{sup -1} and an average adsorption intensity value n = 13.07) showed that A. lechuguilla can be considered as an effective biomaterial for Cr(VI) removal from aqueous solution. Thermodynamic parameters ({delta}G{sup .}, {delta}H{sup .}, and {delta}S{sup .}) for Cr(VI) adsorption determined in the temperature range from (283 to 313) K suggest that a portion of Cr(VI) may be bound to functional groups on the surface of the adsorbent and then reduced to Cr(III). Additionally, the parameters of the Dubinin-Radushkevick equation indicated that the sorption of chromium species onto lechuguilla biomass mainly proceeds through binding surface functional groups.

The complete chloroplast genome sequence of Dianthus superbus var. longicalycinus.

Science.gov (United States)

Gurusamy, Raman; Lee, Do-Hyung; Park, SeonJoo

2016-05-01

The complete chloroplast genome (cpDNA) sequence of Dianthus superbus var. longicalycinus is an economically important traditional Chinese medicine was reported and characterized. The cpDNA of Dianthus superbus var. longicalycinus is 149,539 bp, with 36.3% GC content. A pair of inverted repeats (IRs) of 24,803 bp is separated by a large single-copy region (LSC, 82,805 bp) and a small single-copy region (SSC, 17,128 bp). It encodes 85 protein-coding genes, 36 tRNA genes and 8 rRNA genes. Of 129 individual genes, 13 genes encoded one intron and three genes have two introns.

Anogeissus sericea var. nummalaria King ex Duthie

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 4. Anogeissus sericea var. nummalaria King ex Duthie. Flowering Trees Volume 8 Issue 4 April 2003 pp 89-89. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/008/04/0089-0089. Resonance ...

Identification and characterization of microsatellite markers in Pinus kesiya var. langbianensis (Pinaceae).

Science.gov (United States)

Cai, Nian-Hui; Xu, Yu-Lan; Wang, Da-Wei; Chen, Shi; Li, Gen-Qian

2017-02-01

Microsatellite primers were developed in Pinus kesiya var. langbianensis (Pinaceae), a species native to southwestern China, to investigate its genetic diversity and population structure in order to provide information for the conservation and management of this species. Using next-generation sequencing, a total of 2349 putative simple sequence repeat primer pairs were designed. Eighteen polymorphic markers in 60 individuals belonging to four populations of P. kesiya var. langbianensis were identified and characterized with two to 11 alleles per locus. The observed and expected heterozygosity ranged from 0.000 to 0.800 and 0.000 to 0.840, respectively. Each of these loci cross-amplified in the closely related species P. massoniana , P. densata , P. tabuliformis , and P. yunnanensis , with one to seven alleles per locus. The new markers are promising tools to study the population genetics of P. kesiya var. langbianensis and related species.

Positive selection of Plasmodium falciparum parasites with multiple var2csa-type PfEMP1 genes during the course of infection in pregnant women

DEFF Research Database (Denmark)

Sander, Adam F; Salanti, Ali; Lavstsen, Thomas

2011-01-01

multiple genes coding for different VAR2CSA proteins, and parasites with >1 var2csa gene appear to be more common in pregnant women with placental malaria than in nonpregnant individuals. We present evidence that, in pregnant women, parasites containing multiple var2csa-type genes possess a selective...... advantage over parasites with a single var2csa gene. Accumulation of parasites with multiple copies of the var2csa gene during the course of pregnancy was also correlated with the development of antibodies involved in blocking VAR2CSA adhesion. The data suggest that multiplicity of var2csa-type genes...

VaR: Exchange Rate Risk and Jump Risk

Directory of Open Access Journals (Sweden)

Fen-Ying Chen

2010-01-01

Full Text Available Incorporating the Poisson jumps and exchange rate risk, this paper provides an analytical VaR to manage market risk of international portfolios over the subprime mortgage crisis. There are some properties in the model. First, different from past studies in portfolios valued only in one currency, this model considers portfolios not only with jumps but also with exchange rate risk, that is vital for investors in highly integrated global financial markets. Second, in general, the analytical VaR solution is more accurate than historical simulations in terms of backtesting and Christoffersen's independence test (1998 for small portfolios and large portfolios. In other words, the proposed model is reliable not only for a portfolio on specific stocks but also for a large portfolio. Third, the model can be regarded as the extension of that of Kupiec (1999 and Chen and Liao (2009.

[Effects of mycorrhizal colonization and medicine quality of Paris polyphylla var. yunnanensis inoculated by different foreign AM fungi species].

Science.gov (United States)

Zhou Nong; Ding, Bo; Feng, Yuan; Qi, Wen-hua; Zhang, Hua; Guo, Dong-qin; Xiang, Jun

2015-08-01

After 28 foreign species of AM fungi were inoculated in sterilized soil, the effects of the AM mycorrhizal colonization and the medicine quality of Paris polyphylla var. yunnanensis were observed by combination of inoculation test in pot at room temperature and instrumental analysis. The results showed that, compared with control group (CK), the inoculation of foreign AM fungi in the soil influenced the spore density, mycorrhizal infection rate, and colonization intensity of AM fungi in root system of P. polyphylla var. yunnanensis. The inoculation of foreign AM fungi enhanced the mycorrhiza viability of P. polyphylla var. yunnanensis by increasing the activity of succinic dehydrogenase (SDH) and alkaline phosphatase (ALP) in intraradical hyphae. The content of single steroid saponin in rhizome of P. polyphylla var. yunnanensis showed variation after P. polyphylla var. yunnanensis was inoculated by different foreign species of AM fungi, which was beneficial for increasing the medicine quality; however, the kinds of steroid saponin showed no difference. In a degree, there was a selectivity of symbiosis between P. polyphylla var. yunnanensis and foreign AM fungi. And we found that the Claroideoglomus claroideum and Racocetra coralloidea were best foreign AM fungi species for cultivating P. polyphylla var. yunnanensis under field condition.

The effect of extract of Punica granatum var. pleniflora for treatment of minor recurrent aphthous stomatitis.

Science.gov (United States)

Gavanji, Shahin; Larki, Behrouz; Bakhtari, Azizollah

2014-06-01

Herbal drugs are considered alternative agents and have been used for several years around the world. Recurrent aphthous stomatitis (RAS) is one of the most common problems recognized by dentists and skin specialists. This problem is characterized by recurring, painful, small oral mucosal ulcers with a round or oval aspect that mostly appear in keratinized mucosa, cheeks, and on the surface of the mouth under the tongue. In our experiment, the alcoholic and water extracts of Punica granatum var. pleniflora, P. granatum var. Sweet Alak, and P. granatum var. Saveh Black were tested on minor RAS. The study was carried out using the double-blind method. The study population consisted of 210 participants, of whom 69 were females (32%) and 141 were males (68%). In addition to checking several factors, the pain and the degree of the participant's satisfaction had been determined based on visual analog scale. Data analysis was done in the form of a nonparametric method using Kruskal-Wallis test and SPSS version 20 software. The results show that the alcoholic and water extracts of P. granatum var. pleniflora have a meaningful therapeutic effect on minor RAS. Results from the antioxidant activity and its relation to total phenolics show that P. granatum var. pleniflora and P. granatum var. Sweet Alak are rich in phenols. The water and alcoholic extracts of P. granatum varpleniflora decreased the entire time of complete treatment, and the treatment was meaningfully satisfactory for patients who participated in this experiment.

LitVar: a semantic search engine for linking genomic variant data in PubMed and PMC.

Science.gov (United States)

Allot, Alexis; Peng, Yifan; Wei, Chih-Hsuan; Lee, Kyubum; Phan, Lon; Lu, Zhiyong

2018-05-14

The identification and interpretation of genomic variants play a key role in the diagnosis of genetic diseases and related research. These tasks increasingly rely on accessing relevant manually curated information from domain databases (e.g. SwissProt or ClinVar). However, due to the sheer volume of medical literature and high cost of expert curation, curated variant information in existing databases are often incomplete and out-of-date. In addition, the same genetic variant can be mentioned in publications with various names (e.g. 'A146T' versus 'c.436G>A' versus 'rs121913527'). A search in PubMed using only one name usually cannot retrieve all relevant articles for the variant of interest. Hence, to help scientists, healthcare professionals, and database curators find the most up-to-date published variant research, we have developed LitVar for the search and retrieval of standardized variant information. In addition, LitVar uses advanced text mining techniques to compute and extract relationships between variants and other associated entities such as diseases and chemicals/drugs. LitVar is publicly available at https://www.ncbi.nlm.nih.gov/CBBresearch/Lu/Demo/LitVar.

Further elucidation of the taxonomic relationships and geographic distribution of Escobaria sneedii var. sneedii, E. sneedii var. leei, and E. guadalupensis (Cactaceae)

Science.gov (United States)

Marc A. Baker

2007-01-01

Individuals of E. sneedii var. sneedii were found to occur in greater abundance within the Guadalupe Mountains than was previously recorded. No additional populations morphologically intermediate between E. guadalupensis and E. sneedii were found. Taxonomic affiliation and geographic...

Evaluación no destructiva de la patogenicidad de Cercospora agavicola en vitroplántulas de agave azul tequilero irradiadas con rayos gamma Co60

OpenAIRE

Ángeles-Espino, A.; Virgen-Calleros, G.; Valencia-Botín, J.; Ramírez-Serrano, C.; Paredes-Gutiérrez, L.; Hurtado-De la Peña, S.

2016-01-01

Resumen: El cultivo del agave y el tequila tienen importancia económica y social por los empleos en campo y la industria, además por las divisas de la exportación. El tizón foliar causado por Cercospora agavicola representa un alto riesgo en la zona de Los Altos de Jalisco, debido a que el clima favorece la dispersión y germinación de las esporas. Se inocularon plántulas obtenidas a partir de yemas axilares, mismas que se irradiaron con rayos gamma Co60 a 0 Gy (testigo), 5 Gy, 10 Gy, 15 Gy, 2...

Efficient gene replacements in ku70 disruption strain of Aspergillus chevalieri var. intermedius

Directory of Open Access Journals (Sweden)

Qingqing Huang

2017-01-01

Full Text Available Aspergillus chevalieri var. intermedius is a dominant filamentous fungal species in Fuzhuan tea and is associated with the quality and health benefits of this tea. The sexual or asexual reproduction of this fungus depends on the osmotic pressure of the tea. Efforts to enhance the beneficial effects of A. chevalieri var. intermedius are hampered by difficulties in disrupting its genes. To address this issue, we identified the A. chevalieri var. intermedius homolog (Acku70 of human Ku70 and generated an Acku70 disruption strain (ΔAcku70, aiming to improve the gene replacement efficiency. ΔAcku70 grew at a slightly lower rate in vitro than the wild-type strain; however, the two strains exhibited similar sensitivity to temperature, osmotic pressure and the effects of ethyl methane sulphonate and H2O2. The replacement efficiency of veA and flbA dramatically increased in ΔAcku70 compared to that in the wild type. The efficiency of flbA replacement increased from 2.6% to 80%, whereas the frequency of veA disruption increased from 15.2% to 83.9% and from 30.8% to 86.8%. Thus, ΔAcku70 is suitable for use as a type strain for large-scale functional genomic analysis of A. chevalieri var. intermedius.

RBF neural network prediction on weak electrical signals in Aloe vera var. chinensis

Science.gov (United States)

Wang, Lanzhou; Zhao, Jiayin; Wang, Miao

2008-10-01

A Gaussian radial base function (RBF) neural network forecast on signals in the Aloe vera var. chinensis by the wavelet soft-threshold denoised as the time series and using the delayed input window chosen at 50, is set up to forecast backward. There was the maximum amplitude at 310.45μV, minimum -75.15μV, average value -2.69μV and Aloe vera var. chinensis respectively. The electrical signal in Aloe vera var. chinensis is a sort of weak, unstable and low frequency signals. A result showed that it is feasible to forecast plant electrical signals for the timing by the RBF. The forecast data can be used as the preferences for the intelligent autocontrol system based on the adaptive characteristic of plants to achieve the energy saving on the agricultural production in the plastic lookum or greenhouse.

Mutations in the Arabidopsis AtMRS2-11/AtMGT10/VAR5 Gene Cause Leaf Reticulation

Directory of Open Access Journals (Sweden)

Shuang Liang

2017-11-01

Full Text Available In higher plants, the development of functional chloroplasts is essential for photosynthesis and many other physiological processes. With a long-term goal of elucidating the genetic regulation of chloroplast development, we identified two allelic leaf variegation mutants, variegated5-1 (var5-1 and var5-2. Both mutants showed a distinct leaf reticulation phenotype of yellow paraveinal regions and green interveinal regions, and the leaf reticulation phenotype correlated with photosynthetic defects. Through the identification of mutation sites in the two mutant alleles and the molecular complementation, we confirmed that VAR5 encodes a CorA family of Mg2+ transporters also known as AtMRS2-11/AtMGT10. Using protoplast transient expression and biochemical fractionation assays, we demonstrated that AtMRS2-11/AtMGT10/VAR5 likely localizes to the chloroplast envelope. Moreover, we established that AtMRS2-11/AtMGT10/VAR5 forms large molecular weight complexes in the chloroplast and the sizes of these complexes clearly exceed those of their bacterial counterparts, suggesting the compositions of CorA Mg2+ transporter complex is different between the chloroplast and bacteria. Our findings indicate that AtMRS2-11/AtMGT10/VAR5 plays an important role in the tissue specific regulation of chloroplast development.

RİSK ÖLÇÜMÜNDE ALTERNATİF YAKLAŞIMLAR: RİSKE MARUZ DEĞER (VaR ve BEKLENEN KAYIP (ES UYGULAMALARI

Directory of Open Access Journals (Sweden)

SEZER BOZKUŞ

2013-06-01

Full Text Available This article shows that Value-at-Risk (VaR, the most popular risk measure in practice, has a considerable positive bias when used for a portfolio with fat-tail distribution. Numerical examples, i.e. USD/Euro daily prices and ISE-100 Index monthly returns, are given to demonstrate the use of our method. In the search for a suitable alternative to VaR, Expected Shortfall (ES or conditional VaR has been characterized as the coherent risk measure to dominate VaR. We discuss properties of VaR and ES and compare them in terms of consistency with elimination of tail risk, strengths and weaknesses. We conclude that ES is more applicable than VaR since ES is free of tail risk and consistent under more lenient conditions than VaR is.

Micropropagation of Caralluma stalagmifera var. longipetala : A rare ...

African Journals Online (AJOL)

An efficient in vitro protocol has been developed for the multiplication of shoots and conservation of a rare succulent medicinal plant Caralluma stalagmifera var. longipetala growing wildly in Karnataka State. Proliferation of multiple shoots was achieved on Murashige and Skoog's (MS) medium supplemented with various ...

A measurement of the $C\\!P$ asymmetry difference in $\\varLambda_{c}^{+} \\to pK^{-}K^{+}$ and $p\\pi^{-}\\pi^{+}$ decays

CERN Document Server

Aaij, Roel; LHCb Collaboration; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Alfonso Albero, Alejandro; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Atzeni, Michele; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Baranov, Alexander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Beiter, Andrew; Bel, Lennaert; Beliy, Nikita; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Beranek, Sarah; Berezhnoy, Alexander; Bernet, Roland; Berninghoff, Daniel; Bertholet, Emilie; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Birnkraut, Alex; Bizzeti, Andrea; Bjørn, Mikkel; Blake, Thomas; Blanc, Frederic; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bordyuzhin, Igor; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brodzicka, Jolanta; Brundu, Davide; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Byczynski, Wiktor; Cadeddu, Sandro; Cai, Hao; Calabrese, Roberto; Calladine, Ryan; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Chapman, Matthew George; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu Faye; Chitic, Stefan-Gabriel; Chobanova, Veronika; Chrzaszcz, Marcin; Chubykin, Alexsei; Ciambrone, Paolo; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collins, Paula; Colombo, Tommaso; Comerma-Montells, Albert; Contu, Andrea; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Da Silva, Cesar Luiz; Dall'Occo, Elena; Dalseno, Jeremy; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Del Buono, Luigi; Dembinski, Hans Peter; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Nezza, Pasquale; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Douglas, Lauren; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Durante, Paolo; Durham, John Matthew; Dutta, Deepanwita; Dzhelyadin, Rustem; Dziewiecki, Michal; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fazzini, Davide; Federici, Luca; Ferguson, Dianne; Fernandez, Gerard; Fernandez Declara, Placido; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Lopes, Lino; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gabriel, Emmy; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Govorkova, Ekaterina; Grabowski, Jascha Peter; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greim, Roman; Griffith, Peter; Grillo, Lucia; Gruber, Lukas; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hancock, Thomas Henry; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Hasse, Christoph; Hatch, Mark; He, Jibo; Hecker, Malte; Heinicke, Kevin; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hopchev, Plamen Hristov; Hu, Wenhua; Huang, Wenqian; Huard, Zachary; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Ibis, Philipp; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kazeev, Nikita; Kecke, Matthieu; Keizer, Floris; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Klimkovich, Tatsiana; Koliiev, Serhii; Kolpin, Michael; Kopecna, Renata; Koppenburg, Patrick; Kosmyntseva, Alena; Kotriakhova, Sofia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreps, Michal; Kress, Felix Johannes; Krokovny, Pavel; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Pei-Rong; Li, Tenglin; Li, Yiming; Li, Zhuoming; Liang, Xixin; Likhomanenko, Tatiana; Lindner, Rolf; Lionetto, Federica; Lisovskyi, Vitalii; Liu, Xuesong; Loh, David; Loi, Angelo; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Macko, Vladimir; Mackowiak, Patrick; Maddrell-Mander, Samuel; Maev, Oleg; Maguire, Kevin; Maisuzenko, Dmitrii; Majewski, Maciej Witold; Malde, Sneha; Malecki, Bartosz; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Marangotto, Daniele; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Mead, James Vincent; Meadows, Brian; Meaux, Cedric; Meier, Frank; Meinert, Nis; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Millard, Edward James; Minard, Marie-Noelle; Minzoni, Luca; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Mombächer, Titus; Monroy, Igancio Alberto; Monteil, Stephane; Morandin, Mauro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Ossowska, Anna; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palutan, Matteo; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Pereima, Dmitrii; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pietrzyk, Guillaume; Pikies, Malgorzata; Pinci, Davide; Pisani, Flavio; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poli Lener, Marco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Ponce, Sebastien; Popov, Alexander; Popov, Dmitry; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Pullen, Hannah Louise; Punzi, Giovanni; Qian, Wenbin; Qin, Jia-Jia; Quagliani, Renato; Quintana, Boris; Rachwal, Bartlomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Ravonel Salzgeber, Melody; Reboud, Meril; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Robbe, Patrick; Robert, Arnaud; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Ruiz Vidal, Joan; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarpis, Gediminas; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schreiner, HF; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepulveda, Eduardo Enrique; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavomira; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stepanova, Margarita; Stevens, Holger; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Stramaglia, Maria Elena; Straticiuc, Mihai; Straumann, Ulrich; Sun, Jiayin; Sun, Liang; Swientek, Krzysztof; Syropoulos, Vasileios; Szumlak, Tomasz; Szymanski, Maciej Pawel; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Tourinho Jadallah Aoude, Rafael; Tournefier, Edwige; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Usachov, Andrii; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagner, Alexander; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Verlage, Tobias Anton; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Walsh, John; Wang, Jianchun; Wang, Yilong; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Weisser, Constantin; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Winn, Michael Andreas; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wyllie, Kenneth; Xie, Yuehong; Xu, Menglin; Xu, Qingnian; Xu, Zehua; Xu, Zhirui; Yang, Zhenwei; Yang, Zishuo; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zonneveld, Jennifer Brigitta; Zucchelli, Stefano

2017-01-01

The difference between the $C\\!P$ asymmetries in the decays $\\varLambda_{c}^{+} \\to pK^{-}K^{+}$ and $\\varLambda_{c}^{+} \\to p\\pi^{-}\\pi^{+}$ is presented. Proton-proton collision data taken at centre-of-mass energies of $7$ and $8\\,\\mathrm{TeV}$ collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of $3\\,\\mathrm{fb}^{-1}$. The $\\varLambda_{c}^{+}$ candidates are reconstructed as part of the $\\varLambda_{b}^{0} \\to \\varLambda_{c}^{+}\\mu^{-}X$ decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the \\mbox{$\\varLambda_{c}^{+} \\to p\\pi^{-}\\pi^{+}$} sample. This alters the definition of the integrated $C\\!P$ asymmetry to $A_{C\\!P}^{\\text{wgt}}(p\\pi^{-}\\pi^{+})$. Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional $\\varLambda_{c}^{+}$ decay phase s...

VarR controls colonization and virulence in the marine macroalgal pathogen Nautella italica R11

Directory of Open Access Journals (Sweden)

Melissa eGardiner

2015-10-01

Full Text Available There is increasing evidence to suggest that macroalgae (seaweeds are susceptible to infectious disease. However, to date, little is known about the mechanisms that facilitate the colonization and virulence of microbial seaweed pathogens. One well-described example of a seaweed disease is the bleaching of the red alga Delisea pulchra, which can be caused by the bacterium Nautella italica R11, a member of the Roseobacter clade. This pathogen contains a unique luxR-type gene, varR, which we hypothesize controls its colonization and virulence. We show here that a varR knock-out strain is deficient in its ability to cause disease in D. pulchra and is defective in biofilm formation and attachment to a common algal polysaccharide. Moreover complementation of the varR gene in trans can restore these functions to the wild type levels. Proteomic analysis of bacterial cells in planktonic and biofilm growth highlight the potential importance of nitrogen scavenging, mobilization of energy reserves, and stress resistance in the biofilm lifestyle of N. italica R11. Moreover, we show that VarR regulates the expression of a specific subset of biofilm-associated proteins. Taken together these data suggest that VarR controls colonization and persistence of N. italica R11 on the surface of a macroalgal host and that it is an important regulator of virulence.

VAR IPP-IPC Model Simulation

Directory of Open Access Journals (Sweden)

Juan P. Pérez Monsalve

2014-12-01

Full Text Available This work analyzed the relationship of the two main Price indicators in the Colombian economy, the IPP and the IPC. For this purpose, we identified the theory comprising both indexes to then develop a vector autoregressive model, which shows the reaction to shocks both in itself as in the other variable, whose impact continues propagating in the long term. Additionally, the work presents a simulation of the VAR model through the Monte Carlo method, verifying the coincidence in distributions of probability and volatility levels, as well as the existence correlation over time

Induction of adhesion-inhibitory antibodies against placental Plasmodium falciparum parasites by using single domains of VAR2CSA

DEFF Research Database (Denmark)

Nielsen, Morten A; Pinto, Vera V; Resende, Mafalda

2009-01-01

between a parasite protein expressed on erythrocytes named variant surface antigen 2-chondroitin sulfate A (VAR2CSA) and CSA on syncytiotrophoblasts. VAR2CSA is a large polymorphic protein consisting of six Duffy binding-like (DBL), domains and with current constraints on recombinant protein production...... which induce antibodies that inhibit CSA binding of different parasite strains. In this study, we produced a large panel of VAR2CSA proteins and raised antibodies against these antigens. We show that antibodies against the DBL4 domain effectively inhibit parasite binding. As the inhibition...... was not limited to homologous parasite strains, it seems feasible to base a protective malaria vaccine on a single VAR2CSA DBL domain....

[Leishmaniasis transmission focus in El Hobo, Carmen de Bolívar, Bolívar, Colombia].

Science.gov (United States)

Cortés, Luis Alberto

2006-10-01

The epidemiological characteristics and the importance of the Lutzomyia species present in a leishmaniasis focus in the village El Hobo, Carmen de Bolívar, Department of Bolivar, Colombia, are described. To obtain a preliminary assessment of leishmaniasis transmission in the village of El Hobo, Carmen de Bolívar. Epidemiological data were analyzed and sandflies were collected with CDC traps and on protected human volunteers in the village of El Hobo. Sero prevalence of canine visceral leishmaniasis in dogs was evaluated using indirect inmunofluorescence (IFAT). Nine Lutzomyia species were collected: L. trinidadensis, L. evansi, L. cayennensis, L. venezuelensis, L. gomezi, L. dubitans, L. ylephiletor, L. yuilli, and L. walkeri. The species of greater importance based on their implication in the transmission of cutaneous and visceral leishmaniasis were L. gomezi, and L. evansi respectively. Specimens of L. venezuelensis, L. dubitans, L. ylephiletor, L. yuilli, and L. walkeri are reported for the first time for the Department of Bolivar. The sero prevalence of visceral leishmaniasis in dogs was 36%. According to the epidemiological records, in 2002 the municipality of Carmen de Bolivar presented a 40% increase in cases of cutaneous leishmaniasis and an 80% increase in canine visceral leishmaniasis as compared to 2001, due to the outbreak in the village of El Hobo. The results indicate that the village of El Hobo is an area of potential risk for transmission of both cutaneous and visceral leishmaniasis.

Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter

Science.gov (United States)

Petter, Michaela; Lee, Chin Chin; Byrne, Timothy J.; Boysen, Katja E.; Volz, Jennifer; Ralph, Stuart A.; Cowman, Alan F.; Brown, Graham V.; Duffy, Michael F.

2011-01-01

Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are

Impacts of Bacillus thuringiensis var. israelensis and Bacillus ...

African Journals Online (AJOL)

The study assessed the impact of bio-larvicides- Bacillus thuringiensis var. israelensis (Bti) and B. sphaericus (Bs) on anopheline mosquito larval densities in four selected areas of Lusaka urban district. Larval densities were determined using a standard WHO protocol at each study area prior to and after larviciding.

Scalable and Flexible Multiview MAX-VAR Canonical Correlation Analysis

Science.gov (United States)

Fu, Xiao; Huang, Kejun; Hong, Mingyi; Sidiropoulos, Nicholas D.; So, Anthony Man-Cho

2017-08-01

Generalized canonical correlation analysis (GCCA) aims at finding latent low-dimensional common structure from multiple views (feature vectors in different domains) of the same entities. Unlike principal component analysis (PCA) that handles a single view, (G)CCA is able to integrate information from different feature spaces. Here we focus on MAX-VAR GCCA, a popular formulation which has recently gained renewed interest in multilingual processing and speech modeling. The classic MAX-VAR GCCA problem can be solved optimally via eigen-decomposition of a matrix that compounds the (whitened) correlation matrices of the views; but this solution has serious scalability issues, and is not directly amenable to incorporating pertinent structural constraints such as non-negativity and sparsity on the canonical components. We posit regularized MAX-VAR GCCA as a non-convex optimization problem and propose an alternating optimization (AO)-based algorithm to handle it. Our algorithm alternates between {\\em inexact} solutions of a regularized least squares subproblem and a manifold-constrained non-convex subproblem, thereby achieving substantial memory and computational savings. An important benefit of our design is that it can easily handle structure-promoting regularization. We show that the algorithm globally converges to a critical point at a sublinear rate, and approaches a global optimal solution at a linear rate when no regularization is considered. Judiciously designed simulations and large-scale word embedding tasks are employed to showcase the effectiveness of the proposed algorithm.

Influence of additional coupling agent on the mechanical properties of polyester–agave cantala roxb based composites

Energy Technology Data Exchange (ETDEWEB)

Ubaidillah, E-mail: ubaidillah@uns.ac.id [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia); Raharjo, Wijang W.; Wibowo, A. [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Harjana [Iwany Acoustic Research Group, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Mazlan, S. A., E-mail: amri.kl@utm.my [Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia)

2016-03-29

The mechanical and morphological properties of the unsaturated polyester resins (UPRs)-agave cantala roxb based composite are investigated in this paper. The cantala fiber woven in 3D angle interlock was utilized as the composite reinforcement. Surface grafting of the cantala fiber through chemical treatment was performed by introducing silane coupling agent to improving the compatibility with the polymer matrix. The fabrication of the composite specimens was conducted using vacuum bagging technique. The effect of additional coupling agent to the morphological appearance of surface fracture was observed using scanning electron microscopy. Meanwhile, the influence of additional silane to the mechanical properties was examined using tensile, bending and impact test. The photograph of surface fracture on the treated specimens showed the residual matrix left on the fibers in which the phenomenon was not found in the untreated specimens. Based on mechanical tests, the treated specimens were successfully increased their mechanical properties by 55%, 9.67%, and 92.4% for tensile strength, flexural strength, and impact strength, respectively, at 1.5% silane coupling agent.

Molt disruption and mortality of Locusta migratoria var. manilensis ...

African Journals Online (AJOL)

IGRs) on the oriental migratory locust Locusta migratoria var. manilensis were assessed. Under laboratory conditions, at the highest tested dose rate of 300 ppm, the percent mortality and molt inhibition after two weeks for the five tested ...

Immunogenic Properties of Ricinus Communis Var Minor Seed on ...

African Journals Online (AJOL)

Prof. Ogunji

1College of Health Technology, Zawan, Plateau State.2Department of ... Ricinus communis var minor seed included in their feed (5g/100g body weight). ... White Blood cell Count (WBC) count and lymphocytosis in the differential count.

A var gene promoter implicated in severe malaria nucleates silencing and is regulated by 3' untranslated region and intronic cis-elements.

Science.gov (United States)

Muhle, Rebecca A; Adjalley, Sophie; Falkard, Brie; Nkrumah, Louis J; Muhle, Michael E; Fidock, David A

2009-11-01

Questions surround the mechanism of mutually exclusive expression by which Plasmodium falciparum mediates activation and silencing of var genes. These encode PfEMP1 proteins, which function as cytoadherent and immunomodulatory molecules at the surface of parasitised erythrocytes. Current evidence suggests that promoter silencing by var introns might play a key role in var gene regulation. To evaluate the impact of cis-acting regulatory regions on var silencing, we generated P. falciparum lines in which luciferase was placed under the control of an UpsA var promoter. By utilising the Bxb1 integrase system, these reporter cassettes were targeted to a genomic region that was not in apposition to var subtelomeric domains. This eliminated possible effects from surrounding telomeric elements and removed the variability inherent in episomal systems. Studies with highly synchronised parasites revealed that the UpsA element possessed minimal activity in comparison with a heterologous (hrp3) promoter. This may result from the integrated UpsA promoter being largely silenced by the neighbouring cg6 promoter. Our analyses also revealed that the DownsA 3' untranslated region further decreased the luciferase activity from both cassettes, whereas the var A intron repressed the UpsA promoter specifically. By applying multivariate analysis over the entire cell cycle, we confirmed the significance of these cis-elements and found the parasite stage to be the major factor regulating UpsA-promoter activity. Additionally, we observed that the UpsA promoter was capable of nucleating reversible silencing that spread to a downstream promoter. We believe these studies are the first to analyse promoter activity of Group A var genes, which have been implicated in severe malaria, and support the model that var introns can further suppress var expression. These data also suggest an important suppressive role for the DownsA terminator. Our findings imply the existence of multiple levels of var

Assimilation of Atmospheric InfraRed Sounder (AIRS) Profiles using WRF-Var

Science.gov (United States)

Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

2008-01-01

The Weather Research and Forecasting (WRF) model contains a three-dimensional variational (3DVAR) assimilation system (WRF-Var), which allows a user to join data from multiple sources into one coherent analysis. WRF-Var combines observations with a background field traditionally generated using a previous model forecast through minimization of a cost function. In data sparse regions, remotely-sensed observations may be able to improve analyses and produce improved forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The combined AIRS/AMSU system provides radiance measurements used as input to a sophisticated retrieval scheme which has been shown to produce temperature profiles with an accuracy of 1 K over 1 km layers and humidity profiles with accuracy of 15% in 2 km layers in both clear and partly cloudy conditions. The retrieval algorithm also provides estimates of the accuracy of the retrieved values at each pressure level, allowing the user to select profiles based on the required error tolerances of the application. The purpose of this paper is to describe a procedure to optimally assimilate high-resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type using gen_be and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics in the WRF-Var. The AIRS thermodynamic profiles are obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators are used to select the highest quality temperature and moisture

Several domains from VAR2CSA can induce Plasmodium falciparum adhesion-blocking antibodies

DEFF Research Database (Denmark)

Salanti, Ali; Resende, Mafalda; Ditlev, Sisse B

2010-01-01

. In this study, it is demonstrated that other domains of VAR2CSA also can induce antibodies with inhibitory activity. METHODS: All VAR2CSA domains from the 3D7 and HB3 parasites were produced in Baculovirus-transfected insect cells. Groups of three rats per protein were immunized and anti-sera were tested...

Transcription of the var genes from a freshly-obtained field isolate of Plasmodium falciparum shows more variable switching patterns than long laboratory-adapted isolates.

Science.gov (United States)

Ye, Run; Zhang, Dongmei; Chen, Biaobang; Zhu, Yongqiang; Zhang, Yilong; Wang, Shengyue; Pan, Weiqing

2015-02-07

Antigenic variation in Plasmodium falciparum involves switching among multicopy var gene family and is responsible for immune evasion and the maintenance of chronic infections. Current understanding of var gene expression and switching patterns comes from experiments conducted on long laboratory-adapted strains, with little known about their wild counterparts. Genome sequencing was used to obtain 50 var genes from a parasite isolated from the China-Myanmar border. Four clones with different dominant var genes were cultured in vitro in replicates for 50 generations. Transcription of the individual var gene was detected by real-time PCR and then the switching process was analysed. The expression of multicopy var genes is mutually exclusive in clones of a wild P. falciparum isolate. The activation of distinct primary dominant var genes leads to different and favoured switching patterns in the four clones. The on/off rates of individual var genes are variable and the choice of subsequent dominant var genes are random, which results in the different switching patterns among replicates of each clonal wild P. falciparum isolate with near identical initial transcription profiles. This study suggests that the switching patterns of var genes are abundant, which consist of both conserved and random parts.

A re-assessment of gene-tag classification approaches for describing var gene expression patterns during human Plasmodium falciparum malaria parasite infections.

Science.gov (United States)

Githinji, George; Bull, Peter C

2017-01-01

PfEMP1 are variant parasite antigens that are inserted on the surface of Plasmodium falciparum infected erythrocytes (IE). Through interactions with various host molecules, PfEMP1 mediate IE sequestration in tissues and play a key role in the pathology of severe malaria. PfEMP1 is encoded by a diverse multi-gene family called var . Previous studies have shown that that expression of specific subsets of var genes are associated with low levels of host immunity and severe malaria. However, in most clinical studies to date, full-length var gene sequences were unavailable and various approaches have been used to make comparisons between var gene expression profiles in different parasite isolates using limited information. Several studies have relied on the classification of a 300 - 500 base-pair "DBLα tag" region in the DBLα domain located at the 5' end of most var genes. We assessed the relationship between various DBLα tag classification methods, and sequence features that are only fully assessable through full-length var gene sequences. We compared these different sequence features in full-length var gene from six fully sequenced laboratory isolates. These comparisons show that despite a long history of recombination,   DBLα sequence tag classification can provide functional information on important features of full-length var genes. Notably, a specific subset of DBLα tags previously defined as "group A-like" is associated with CIDRα1 domains proposed to bind to endothelial protein C receptor. This analysis helps to bring together different sources of data that have been used to assess var gene expression in clinical parasite isolates.

Putative DNA G-quadruplex formation within the promoters of Plasmodium falciparum var genes

Directory of Open Access Journals (Sweden)

Rowe J

2009-08-01

Full Text Available Abstract Background Guanine-rich nucleic acid sequences are capable of folding into an intramolecular four-stranded structure called a G-quadruplex. When found in gene promoter regions, G-quadruplexes can downregulate gene expression, possibly by blocking the transcriptional machinery. Here we have used a genome-wide bioinformatic approach to identify Putative G-Quadruplex Sequences (PQS in the Plasmodium falciparum genome, along with biophysical techniques to examine the physiological stability of P. falciparum PQS in vitro. Results We identified 63 PQS in the non-telomeric regions of the P. falciparum clone 3D7. Interestingly, 16 of these PQS occurred in the upstream region of a subset of the P. falciparum var genes (group B var genes. The var gene family encodes PfEMP1, the parasite's major variant antigen and adhesin expressed at the surface of infected erythrocytes, that plays a key role in malaria pathogenesis and immune evasion. The ability of the PQS found in the upstream regions of group B var genes (UpsB-Q to form stable G-quadruplex structures in vitro was confirmed using 1H NMR, circular dichroism, UV spectroscopy, and thermal denaturation experiments. Moreover, the synthetic compound BOQ1 that shows a higher affinity for DNA forming quadruplex rather than duplex structures was found to bind with high affinity to the UpsB-Q. Conclusion This is the first demonstration of non-telomeric PQS in the genome of P. falciparum that form stable G-quadruplexes under physiological conditions in vitro. These results allow the generation of a novel hypothesis that the G-quadruplex sequences in the upstream regions of var genes have the potential to play a role in the transcriptional control of this major virulence-associated multi-gene family.

Transient Stability Enhancement in Power System Using Static VAR Compensator (SVC

Directory of Open Access Journals (Sweden)

Youssef MOULOUDI

2012-12-01

Full Text Available In this paper, an indirect adaptive fuzzy excitation and static VAR (unit of reactive power, volt-ampere reactive compensator (SVC controller is proposed to enhance transient stability for the power system, which based on input-output linearization technique. A three-bus system, which contains a generator and static VAR compensator (SVC, is considered in this paper, the SVC is located at the midpoint of the transmission lines. Simulation results show that the proposed controller compared with a controller based on tradition linearization technique can enhance the transient stability of the power system under a large sudden fault, which may occur nearly at the generator bus terminal.

MANAGEMENT OF Amburana cearensis var. acreana IN ACRE STATE, BRAZIL

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Evaldo Muñoz Braz

2014-06-01

Full Text Available http://dx.doi.org/10.5902/1980509814586This work has as its objectives: a to assess the geographical distribution and population structure of Amburana cearensis var. acreana; b to calculate sustainable cutting rates, according to stipulated cutting cycles, and c to simulate the projected recovery potential in volume based on the calculated cutting rate. It was used data from sustainable forest management plans, and the results will contribute for future decisions about its endangered condition. The results did not corroborate the information that Amburana cearensis var. acreana is endangered in Acre state. However the management sustainability will only be feasible if considered the ideal remaining population structure and the estimative of the optimal cutting rate according to the cutting cycle.

Anogeissus sericea var. nummalaria King ex Duthie (Combretaceae ...

Indian Academy of Sciences (India)

Anogeissus sericea var. nummalaria King ex Duthie (Combretaceae) is moderate sized multipurpose hard wood tree of dry deciduous forests with drooping branches and yellow to brownish-yellow flowers. it is endemic to Rajasthan and is considered to be a threatened tree of the region due to over exploitation for timber ...

Spatial and temporal variations of Cocconeis placentula var. euglypta (Ehrenb. 1854 Grunow, 1884 in drift and periphyton

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EN. Gari

Full Text Available Spatial and temporal variations of Cocconeis placentula var. euglypta in drift and periphyton were studied in mountain streams of the Córdoba Province (Argentina. The sampling program was conducted in study sites located on a confluence between different order streams during an annual cycle. Samples were also taken every two hours during the daylight period in high and low water conditions. The relationship between drift and cellular reproduction was evaluated by valve length biometrics analysis. C. placentula var. euglypta drift was continuous; its density was not always dependent on periphyton density in each locality. C. placentula var. euglypta drift could be related to abiotic factors such as temperature and flow during the annual cycle. There were significant differences between periphyton and drift valve lengths. Moreover, drift can be associated with cellular reproduction because density was higher when valve lengths were shorter at different hours of the day. C. placentula var. euglypta epiphytims on Cladophora glomerata also influenced drift density and size distribution, modifying the relationship between periphyton and drift during the late spring when C. placentula var. euglypta was detached from senescent mats.

Clinical laboratories collaborate to resolve differences in variant interpretations submitted to ClinVar.

Science.gov (United States)

Harrison, Steven M; Dolinsky, Jill S; Knight Johnson, Amy E; Pesaran, Tina; Azzariti, Danielle R; Bale, Sherri; Chao, Elizabeth C; Das, Soma; Vincent, Lisa; Rehm, Heidi L

2017-10-01

Data sharing through ClinVar offers a unique opportunity to identify interpretation differences between laboratories. As part of a ClinGen initiative, four clinical laboratories (Ambry, GeneDx, Partners Healthcare Laboratory for Molecular Medicine, and University of Chicago Genetic Services Laboratory) collaborated to identify the basis of interpretation differences and to investigate if data sharing and reassessment resolve interpretation differences by analyzing a subset of variants. ClinVar variants with submissions from at least two of the four participating laboratories were compared. For a subset of identified differences, laboratories documented the basis for discordance, shared internal data, independently reassessed with the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) guidelines, and then compared interpretations. At least two of the participating laboratories interpreted 6,169 variants in ClinVar, of which 88.3% were initially concordant. Laboratories reassessed 242/724 initially discordant variants, of which 87.2% (211) were resolved by reassessment with current criteria and/or internal data sharing; 12.8% (31) of reassessed variants remained discordant owing to differences in the application of the ACMG-AMP guidelines. Participating laboratories increased their overall concordance from 88.3 to 91.7%, indicating that sharing variant interpretations in ClinVar-thereby allowing identification of differences and motivation to resolve those differences-is critical to moving toward more consistent variant interpretations.Genet Med advance online publication 09 March 2017.

Value at risk (VaR in uncertainty: Analysis with parametric method and black & scholes simulations

Directory of Open Access Journals (Sweden)

Humberto Banda Ortiz

2014-07-01

Full Text Available VaR is the most accepted risk measure worldwide and the leading reference in any risk management assessment. However, its methodology has important limitations which makes it unreliable in contexts of crisis or high uncertainty. For this reason, the aim of this work is to test the VaR accuracy when is employed in contexts of volatility, for which we compare the VaR outcomes in scenarios of both stability and uncertainty, using the parametric method and a historical simulation based on data generated with the Black & Scholes model. VaR main objective is the prediction of the highest expected loss for any given portfolio, but even when it is considered a useful tool for risk management under conditions of markets stability, we found that it is substantially inaccurate in contexts of crisis or high uncertainty. In addition, we found that the Black & Scholes simulations lead to underestimate the expected losses, in comparison with the parametric method and we also found that those disparities increase substantially in times of crisis. In the first section of this work we present a brief context of risk management in finance. In section II we present the existent literature relative to the VaR concept, its methods and applications. In section III we describe the methodology and assumptions used in this work. Section IV is dedicated to expose the findings. And finally, in Section V we present our conclusions.

Sub-grouping of Plasmodium falciparum 3D7 var genes based on sequence analysis of coding and non-coding regions

DEFF Research Database (Denmark)

Lavstsen, Thomas; Salanti, Ali; Jensen, Anja T R

2003-01-01

and organization of the 3D7 PfEMP1 repertoire was investigated on the basis of the complete genome sequence. METHODS: Using two tree-building methods we analysed the coding and non-coding sequences of 3D7 var and rif genes as well as var genes of other parasite strains. RESULTS: var genes can be sub...

JIL-1 and Su(var)3-7 Interact Genetically and Counteract Each Other's Effect on Position-Effect Variegation in Drosophila

Science.gov (United States)

Deng, Huai; Cai, Weili; Wang, Chao; Lerach, Stephanie; Delattre, Marion; Girton, Jack; Johansen, Jørgen; Johansen, Kristen M.

2010-01-01

The essential JIL-1 histone H3S10 kinase is a key regulator of chromatin structure that functions to maintain euchromatic domains while counteracting heterochromatization and gene silencing. In the absence of the JIL-1 kinase, two of the major heterochromatin markers H3K9me2 and HP1a spread in tandem to ectopic locations on the chromosome arms. Here we address the role of the third major heterochromatin component, the zinc-finger protein Su(var)3-7. We show that the lethality but not the chromosome morphology defects associated with the null JIL-1 phenotype to a large degree can be rescued by reducing the dose of the Su(var)3-7 gene and that Su(var)3-7 and JIL-1 loss-of-function mutations have an antagonistic and counterbalancing effect on position-effect variegation (PEV). Furthermore, we show that in the absence of JIL-1 kinase activity, Su(var)3-7 gets redistributed and upregulated on the chromosome arms. Reducing the dose of the Su(var)3-7 gene dramatically decreases this redistribution; however, the spreading of H3K9me2 to the chromosome arms was unaffected, strongly indicating that ectopic Su(var)3-9 activity is not a direct cause of lethality. These observations suggest a model where Su(var)3-7 functions as an effector downstream of Su(var)3-9 and H3K9 dimethylation in heterochromatic spreading and gene silencing that is normally counteracted by JIL-1 kinase activity. PMID:20457875

Multiple var2csa-type PfEMP1 genes located at different chromosomal loci occur in many Plasmodium falciparum isolates

DEFF Research Database (Denmark)

Sander, Adam F; Salanti, Ali; Lavstsen, Thomas

2009-01-01

in the VAR2CSA protein, sequence variation in the DBL2X region of var2csa genes in 54 P.falciparum samples was analyzed. Chromosome mapping of var2csa loci was carried out and a quantitative PCR assay was developed to estimate the number of var2csa genes in P.falciparum isolates from the placenta of pregnant....... falciparum isolates. One gene is on chromosome 12 but additional var2csa-type genes are on different chromosomes in different isolates. Multiplicity of var2csa genes appears more common in infected placentae than in samples from non-pregnant donors indicating a possible advantage of this genotype...

New xenophytes from Gran Canaria (Canary Islands, Spain, with emphasis on naturalized and (potentially invasive species

Directory of Open Access Journals (Sweden)

Verloove, F.

2013-12-01

Full Text Available Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum chrysotrichum, Tecoma stans, Tipuana tipu, Urochloa mutica, U. plantaginea y Washingtonia se citan por primera vez para las Islas Canarias, mientras que Alopecurus myosuroides, Amaranthus blitoides, Bothriochloa ischaemum var. songarica, Cardamine flexuosa subsp. debilis, Heliotropium curassavicum, Leonotis nepetifolia, Medicago lupulina, Parkinsonia aculeata, Physalis peruviana, Phytolacca americana y Turnera ulmifolia son nuevas para la flora de la isla de Gran Canaria. Finalmente, se confirma la presencia de Paspalum vaginatum, P. distichum y Cortaderia selloana en Gran Canaria.Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum

Analysis of simple sequence repeats in the Gaeumannomyces graminis var. tritici genome and the development of microsatellite markers.

Science.gov (United States)

Li, Wei; Feng, Yanxia; Sun, Haiyan; Deng, Yuanyu; Yu, Hanshou; Chen, Huaigu

2014-11-01

Understanding the genetic structure of Gaeumannomyces graminis var. tritici is essential for the establishment of efficient disease control strategies. It is becoming clear that microsatellites, or simple sequence repeats (SSRs), play an important role in genome organization and phenotypic diversity, and are a large source of genetic markers for population genetics and meiotic maps. In this study, we examined the G. graminis var. tritici genome (1) to analyze its pattern of SSRs, (2) to compare it with other plant pathogenic filamentous fungi, such as Magnaporthe oryzae and M. poae, and (3) to identify new polymorphic SSR markers for genetic diversity. The G. graminis var. tritici genome was rich in SSRs; a total 13,650 SSRs have been identified with mononucleotides being the most common motifs. In coding regions, the densities of tri- and hexanucleotides were significantly higher than in noncoding regions. The di-, tri-, tetra, penta, and hexanucleotide repeats in the G. graminis var. tritici genome were more abundant than the same repeats in M. oryzae and M. poae. From 115 devised primers, 39 SSRs are polymorphic with G. graminis var. tritici isolates, and 8 primers were randomly selected to analyze 116 isolates from China. The number of alleles varied from 2 to 7 and the expected heterozygosity (He) from 0.499 to 0.837. In conclusion, SSRs developed in this study were highly polymorphic, and our analysis indicated that G. graminis var. tritici is a species with high genetic diversity. The results provide a pioneering report for several applications, such as the assessment of population structure and genetic diversity of G. graminis var. tritici.

Optimization of alkaline and dilute acid pretreatment of agave bagasse by response surface methodology

Directory of Open Access Journals (Sweden)

Abimael I. Ávila-Lara

2015-09-01

Full Text Available Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA and alkaline (AL catalyst providing specific effects on the physicochemical structure of the biomass such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15% since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification which will be reflected in lower capital costs, however this data is currently limited. In this study, several variables such as catalyst loading, retention time and solids loading, were studied using Response Surface Methodology (RSM based on a factorial Central Composite Design (CCD of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS yield. Pretreated biomass

Fiscal developments and financial stress: a threshold VAR analysis

Czech Academy of Sciences Publication Activity Database

Afonso, A.; Baxa, Jaromír; Slavík, M.

2011-01-01

Roč. 2011, č. 1319 (2011), s. 1-60 ISSN 1725-2806 Institutional research plan: CEZ:AV0Z10750506 Keywords : fiscal policy * financial markets * threshold VAR Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2011/E/baxa-0364091.pdf

Technology of VAr Compensators for Induction Generator Applications in Wind Energy Conversion Systems

Directory of Open Access Journals (Sweden)

A. F. Zobaa

2006-09-01

Full Text Available Many of today utility interconnected wind farms use induction generator (IG to convert the captured wind mechanical power into electricity. Induction generator has some advantages over the synchronous generator (SG. The main advantages are its robustness and its capability to be synchronized directly to the grid. The main disadvantage, however, is its dependency on the grid for supplying its own reactive power ‘VAr’. Whether fixed or adjustable VAr systems are connected across its terminal, IG must operate at unity power factor at the rated loading while the wind power varies. With supervised control and appropriate coordination, VAr can be used to the benefits of both the wind farm developer and the hosting utility. The incorporation of today adjustable reactive power compensators such as the Static VAr Compensation (SVC and Static Synchronous Compensator (STATCOM with IG are vital ingredient toward a successful penetration of wind energy in today distribution grid to ensure voltage stability during the steady state and transient periods.

Antioxidant properties and global metabolite screening of the probiotic yeast Saccharomyces cerevisiae var. boulardii.

Science.gov (United States)

Datta, Suprama; Timson, David J; Annapure, Uday S

2017-07-01

Saccharomyces cerevisiae var. boulardii is the only yeast species with probiotic properties. It is considered to have therapeutic significance in gastrointestinal disorders. In the present study, a comparative physiological study between this yeast and Saccharomyces cerevisiae (BY4742) was performed by evaluating two prominent traits of probiotic species, responses to different stress conditions and antioxidant capacity. A global metabolite profile was also developed aiming to identify which therapeutically important secondary metabolites are produced. Saccharomyces cerevisiae var. boulardii showed no significant difference in growth patterns but greater stress tolerance compared to S. cerevisiae. It also demonstrated a six- to 10-fold greater antioxidant potential (judged by the 1,1-diphenyl-2-picrylhydrazyl assay), with a 70-fold higher total phenolic content and a 20-fold higher total flavonoid content in the extracellular fraction. These features were clearly differentiated by principal component analysis and further indicated by metabolite profiling. The extracellular fraction of the S. cerevisiae var. boulardii cultures was found to be rich in polyphenolic metabolites: vanillic acid, cinnamic acid, phenyl ethyl alcohol (rose oil), erythromycin, amphetamine and vitamin B 6 , which results in the antioxidant capacity of this strain. The present study presents a new perspective for differentiating the two genetically related strains of yeast, S. cerevisiae and S. cerevisiae var. boulardii by assessing their metabolome fingerprints. In addition to the correlation of the phenotypic properties with the secretory metabolites of these two yeasts, the present study also emphasizes the potential to exploit S. cerevisiae var. boulardii in the industrial production of these metabolites. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Transcriptome analysis of Panax vietnamensis var. fuscidicus discovers putative ocotillol-type ginsenosides biosynthesis genes and genetic markers.

Science.gov (United States)

Zhang, Guang-Hui; Ma, Chun-Hua; Zhang, Jia-Jin; Chen, Jun-Wen; Tang, Qing-Yan; He, Mu-Han; Xu, Xiang-Zeng; Jiang, Ni-Hao; Yang, Sheng-Chao

2015-03-08

P. vietnamensis var. fuscidiscus, called "Yesanqi" in Chinese, is a new variety of P. vietnamensis, which was first found in Jinping County, the southern part of Yunnan Province, China. Compared with other Panax plants, this species contains higher content of ocotillol-type saponin, majonoside R2. Despite the pharmacological importance of ocotillol-type saponins, little is known about their biosynthesis in plants. Hence, P. vietnamensis var. fuscidiscus is a suitable medicinal herbal plant species to study biosynthesis of ocotillol-type saponins. In addition, the available genomic information of this important herbal plant is lacking. To investigate the P. vietnamensis var. fuscidiscus transcriptome, Illumina HiSeq™ 2000 sequencing platform was employed. We produced 114,703,210 clean reads, assembled into 126,758 unigenes, with an average length of 1,304 bp and N50 of 2,108 bp. Among these 126,758 unigenes, 85,214 unigenes (67.23%) were annotated based on the information available from the public databases. The transcripts encoding the known enzymes involved in triterpenoid saponins biosynthesis were identified in our Illumina dataset. A full-length cDNA of three Squalene epoxidase (SE) genes were obtained using reverse transcription PCR (RT-PCR) and the expression patterns of ten unigenes were analyzed by reverse transcription quantitative real-time PCR (RT-qPCR). Furthermore, 15 candidate cytochrome P450 genes and 17 candidate UDP-glycosyltransferase genes most likely to involve in triterpenoid saponins biosynthesis pathway were discovered from transcriptome sequencing of P. vietnamensis var. fuscidiscus. We further analyzed the data and found 21,320 simple sequence repeats (SSRs), 30 primer pairs for SSRs were randomly selected for validation of the amplification and polymorphism in 13 P. vietnamensis var. fuscidiscus accessions. Meanwhile, five major triterpene saponins in roots of P. vietnamensis var. fuscidicus were determined using high performance

Utilizing nanobody technology to target non-immunodominant domains of VAR2CSA

DEFF Research Database (Denmark)

Ditlev, Sisse B; Florea, Raluca; Nielsen, Morten A

2014-01-01

adhesion. However, the development of a VAR2CSA adhesion-blocking vaccine remains challenging due to (i) the large size of VAR2CSA and (ii) the extensive immune selection for polymorphisms and thereby non-neutralizing B-cell epitopes. Camelid heavy-chain-only antibodies (HcAbs) are known to target epitopes...... that are less immunogenic to classical IgG and, due to their small size and protruding antigen-binding loop, able to reach and recognize cryptic, conformational epitopes which are inaccessible to conventional antibodies. The variable heavy chain (VHH) domain is the antigen-binding site of camelid HcAbs, the so...

Differential recognition of terminal extracellular Plasmodium falciparum VAR2CSA domains by sera from multigravid, malaria-exposed Malian women.

Science.gov (United States)

Travassos, Mark A; Coulibaly, Drissa; Bailey, Jason A; Niangaly, Amadou; Adams, Matthew; Nyunt, Myaing M; Ouattara, Amed; Lyke, Kirsten E; Laurens, Matthew B; Pablo, Jozelyn; Jasinskas, Algis; Nakajima, Rie; Berry, Andrea A; Takala-Harrison, Shannon; Kone, Abdoulaye K; Kouriba, Bourema; Rowe, J Alexandra; Doumbo, Ogobara K; Thera, Mahamadou A; Laufer, Miriam K; Felgner, Philip L; Plowe, Christopher V

2015-06-01

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediates parasite sequestration in small capillaries through tissue-specific cytoadherence. The best characterized of these proteins is VAR2CSA, which is expressed on the surface of infected erythrocytes that bind to chondroitin sulfate in the placental matrix. Antibodies to VAR2CSA prevent placental cytoadherence and protect against placental malaria. The size and complexity of the VAR2CSA protein pose challenges for vaccine development, but smaller constitutive domains may be suitable for subunit vaccine development. A protein microarray was printed to include five overlapping fragments of the 3D7 VAR2CSA extracellular region. Malian women with a history of at least one pregnancy had antibody recognition of four of these fragments and had stronger reactivity against the two distal fragments than did nulliparous women, children, and men from Mali, suggesting that the C-terminal extracellular VAR2CSA domains are a potential focus of protective immunity. With carefully chosen sera from longitudinal studies of pregnant women, this approach has the potential to identify seroreactive VAR2CSA domains associated with protective immunity against pregnancy-associated malaria. © The American Society of Tropical Medicine and Hygiene.

A var gene promoter implicated in severe malaria nucleates silencing and is regulated by 3’ untranslated region and intronic cis-elements

Science.gov (United States)

Muhle, Rebecca A.; Adjalley, Sophie; Falkard, Brie; Nkrumah, Louis J.; Muhle, Michael E.; Fidock, David A.

2009-01-01

Questions surround the mechanism of mutually exclusive expression by which Plasmodium falciparum mediates activation and silencing of var genes. These encode PfEMP1 proteins, which function as cytoadherent and immunomodulatory molecules at the surface of parasitized erythrocytes. Current evidence suggests that promoter silencing by var introns might play a key role in var gene regulation. To evaluate the impact of cis-acting regulatory regions on var silencing, we generated P. falciparum lines in which luciferase was placed under the control of an UpsA var promoter. By utilizing the Bxb1 integrase system, these reporter cassettes were targeted to a genomic region that was not in apposition to var sub-telomeric domains. This eliminated possible effects from surrounding telomeric elements and removed the variability inherent in episomal systems. Studies with highly synchronized parasites revealed that the UpsA element possessed minimal activity in comparison with a heterologous (hrp3) promoter. This may well result from the integrated UpsA promoter being largely silenced by the neighboring cg6 promoter. Our analyses also revealed that the DownsA 3’ untranslated region further decreased the luciferase activity from both cassettes, whereas the var A intron repressed the UpsA promoter specifically. By applying multivariate analysis over the entire cell cycle, we confirmed the significance of these cis-elements and found the parasite stage to be the major factor regulating UpsA promoter activity. Additionally, we observed that the UpsA promoter was capable of nucleating reversible silencing that spread to a downstream promoter. We believe these studies are the first to analyze promoter activity of Group A var genes which have been implicated in severe malaria, and support the model that var introns can further suppress var expression. These data also suggest an important suppressive role for the DownsA terminator. Our findings imply the existence of multiple levels of

Characterization of flavonoids in Millettia nitida var. hirsutissima by HPLC/DAD/ESI-MS n

OpenAIRE

Ye, Min; Yang, Wen-Zhi; Liu, Ke-Di; Qiao, Xue; Li, Bei-Jia; Cheng, Jun; Feng, Jie; Guo, De-An; Zhao, Yu-Ying

2011-01-01

Millettia nitida var. hirsutissima is a Chinese herbal medicine used for the treatment of gynecological diseases. An HPLC/DAD/ESI-MSn method was established for the rapid separation and characterization of bioactive flavonoids in M. nitida var. hirsutissima. A total of 32 flavonoids were detected, of which 14 compounds were unambiguously characterized by comparing their retention time, UV, and MS spectra with those of the reference standards, and the others were tentatively identified based o...

Description of rainfall variability in Br hat -samhita of Varâha-mihira

OpenAIRE

Iyengar, RN

2004-01-01

Br hat -samhita of Varâha-mihira (5–6th century AD) provides valuable information on the approach in ancient India towards monsoon rainfall, including its measurement and forecasting. In this context, we come across a description of the expected amount of total seasonal rainfall depending on the first rains under the 27 naks atras of Indian astronomy. This provides a rough statistical picture of what might have been the rainfall and its variability in the region around Ujjain, where Varâha-mi...

Bolívar, primer diplomático de la libertad americana

Directory of Open Access Journals (Sweden)

Rafael Gómez Hoyos

1969-03-01

Full Text Available Don Miguel Luis Amunátegui, primer biógrafo de don Andrés Bello, recopilador y comentarista meritorio de sus obras, nos dejó una falsa visión de Bolívar como diplomático de la libertad. Basado en los recuerdos del anciano humanista, cuando ya le flaqueaba la memoria, o gracias a un error suyo de apreciación, al comentar los incidentes de la misión encomendada ante el gobierno británico por la Junta Suprema de Caracas, nos relata increíble falta de tacto y descuido imperdonable en Simón Bolívar, Jefe de la Misión.

Evidence that the human pathogenic fungus Cryptococcus neoformans var. grubii may have evolved in Africa.