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1

Natural DNA variation at candidate loci is associated with potato chip color, tuber starch content, yield and starch yield  

Microsoft Academic Search

Complex characters of plants such as starch and sugar content of seeds, fruits, tubers and roots are controlled by multiple\\u000a genetic and environmental factors. Understanding their molecular basis will facilitate diagnosis and combination of superior\\u000a alleles in crop improvement programs (“precision breeding”). Association genetics based on candidate genes is one approach\\u000a toward this goal. Tetraploid potato varieties and breeding clones

Li Li; Maria-João Paulo; Josef Strahwald; Jens Lübeck; Hans-Reinhard Hofferbert; Eckhart Tacke; Holger Junghans; Jörg Wunder; Astrid Draffehn; Fred van Eeuwijk; Christiane Gebhardt

2008-01-01

2

Regulation of starch synthesis in potato tubers  

SciTech Connect

Following tuber excision from the mother plant sucrose synthase activity fell from 3,120 to 960 nmol/g.f. wt./h within 7 days and starch synthesis ({sup 14}C sucrose incorporated into isolated discs) from 23 to 7 nmol/g.f. wt./h. While the maximum catalytic activity of sucrose synthase was more than sufficient to account for the observed rate of starch synthesis a maximum of 27% of sucrose incorporated by discs was converted into starch within 3 h. This compared with 80% conversion of {sup 14}C glucose incorporated. Tuber excision also reduced the rate of starch biosynthesis with glucose as a substrate (from 206 to 64 nmol/g.f. wt./h). The activities of UDPG-pyrophosphorylase, PPi-PFK, ATP-PFK, starch synthase and hexokinase (glucose or fructose substrates) were unaffected by tuber removal. ADPG pyrophosphorylase activity was reduced from 8,000 to 4,500 nmol/g.f. wt./h. Preliminary experiments indicate that the decline in sucrose synthease activity is prevented by maintaining sucrose flux into tubers through the cut stolon.

Davies, H.; Oparka, K.; Viola, R.; Wright, K.; Ross, H. (Scottish Crop Res. Inst., Dundee (Scotland))

1990-05-01

3

Experiment 9: ASTROCULTURE: Growth and Starch Accumulation of Potato Tuber  

NASA Technical Reports Server (NTRS)

Potato explants (leaf, small stem section, and axillary bud) flown on STS-73 developed tubers of 1.5 cm diameter and 1.7 g mass during the 16-day period of space flight. The experiment was undertaken in the ASTROCULTURE(TM) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers that formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was similar in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in space flight and ground controls, but activity of ADP-glucose pyrophosphorylase was reduced in the space flight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in space flight as on the ground. Thus, this data provides the potential for effective utilization of potatoes in life support systems of space bases.

Tibbitts, Theodore W.; Brown, Christopher S.; Croxdale, Judith G.; Wheeler, Raymond M.

1998-01-01

4

Space Experiment on Tuber Development and Starch Accumulation for CELSS  

NASA Technical Reports Server (NTRS)

Potato explants (leaf, small stem section, and axillary bud), flown on STS-73, developed tubers of 1.5 cm diameter and 1.7 g mass during the 16 day period of spaceflight. The experiment was undertaken in the ASTROCULTURE(Trademark) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was singular in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in spaceflight and ground controls but activity of ADP-glucose pyrophosphorylase was reduced in the spaceflight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in spaceflight as on the ground and thus this data provides the potential for effective utilization of potatoes in life support systems of space bases.

Tibbitts,Theodore W.; Croxdale, Judith C.; Brown, Christopher S.

1997-01-01

5

Functional Properties of Hydroxypropylated, Cross-Linked, and Hydroxypropylated Cross-Linked Tuber and Root Starches  

Microsoft Academic Search

Cereal Chem. 84(1):30-37 Functional properties of some underexploited tuber and root starches (true yam, gourd yam, taro, lotus, and sweet potato) were investigated before and after hydroxypropylation, cross-linking, and hydroxypropylation and cross-linking using potato starch as the reference. Low swelling ability, poor viscosity development but high shear stability, gel hardness, and resistance to enzyme hydrolysis was observed in starches from

Anil Gunaratne; Harold Corke

2007-01-01

6

Manipulation of starch granule size distribution in potato tubers by modulation of plastid division.  

PubMed

Starch granule size is an important parameter for starch applications in industry. Starch granules are formed in amyloplasts, which are, like chloroplasts, derived from proplastids. Division processes and associated machinery are likely to be similar for all plastids. Essential roles for FtsZ proteins in plastid division in land plants have been revealed. FtsZ forms the so-called Z ring which, together with inner and outer plastid division rings, brings about constriction of the plastid. It has been shown that modulation of the expression level of FtsZ may result in altered chloroplast size and number. To test whether FtsZ is also involved in amyloplast division and whether this, in turn, may affect the starch granule size in crop plants, FtsZ protein levels were either reduced or increased in potato. As shown previously in other plant species, decreased StFtsZ1 protein levels in leaves resulted in a decrease in the number of chloroplasts in guard cells. More interestingly, plants with increased StFtsZ1 protein levels in tubers resulted in less, but larger, starch granules. This suggests that the stoichiometry between StFtsZ1 and other components of the plastid division machinery is important for its function. Starch from these tubers also had altered pasting properties and phosphate content. The importance of our results for the starch industry is discussed. PMID:17177791

de Pater, Sylvia; Caspers, Martien; Kottenhagen, Marijke; Meima, Henk; ter Stege, Renaldo; de Vetten, Nick

2006-01-01

7

SNPs in Genes Functional in Starch-Sugar Interconversion Associate with Natural Variation of Tuber Starch and Sugar Content of Potato (Solanum tuberosum L.).  

PubMed

Starch accumulation and breakdown are vital processes in plant storage organs such as seeds, roots, and tubers. In tubers of potato (Solanum tuberosum L.) a small fraction of starch is converted into the reducing sugars glucose and fructose. Reducing sugars accumulate in response to cold temperatures. Even small quantities of reducing sugars affect negatively the quality of processed products such as chips and French fries. Tuber starch and sugar content are inversely correlated complex traits that are controlled by multiple genetic and environmental factors. Based on in silico annotation of the potato genome sequence, 123 loci are involved in starch-sugar interconversion, approximately half of which have been previously cloned and characterized. By means of candidate gene association mapping, we identified single-nucleotide polymorphisms (SNPs) in eight genes known to have key functions in starch-sugar interconversion, which were diagnostic for increased tuber starch and/or decreased sugar content and vice versa. Most positive or negative effects of SNPs on tuber-reducing sugar content were reproducible in two different collections of potato cultivars. The diagnostic SNP markers are useful for breeding applications. An allele of the plastidic starch phosphorylase PHO1a associated with increased tuber starch content was cloned as full-length cDNA and characterized. The PHO1a-HA allele has several amino acid changes, one of which is unique among all known starch/glycogen phosphorylases. This mutation might cause reduced enzyme activity due to impaired formation of the active dimers, thereby limiting starch breakdown. PMID:25081979

Schreiber, Lena; Nader-Nieto, Anna Camila; Schönhals, Elske Maria; Walkemeier, Birgit; Gebhardt, Christiane

2014-01-01

8

SNPs in Genes Functional in Starch-Sugar Interconversion Associate with Natural Variation of Tuber Starch and Sugar Content of Potato (Solanum tuberosum L.)  

PubMed Central

Starch accumulation and breakdown are vital processes in plant storage organs such as seeds, roots, and tubers. In tubers of potato (Solanum tuberosum L.) a small fraction of starch is converted into the reducing sugars glucose and fructose. Reducing sugars accumulate in response to cold temperatures. Even small quantities of reducing sugars affect negatively the quality of processed products such as chips and French fries. Tuber starch and sugar content are inversely correlated complex traits that are controlled by multiple genetic and environmental factors. Based on in silico annotation of the potato genome sequence, 123 loci are involved in starch-sugar interconversion, approximately half of which have been previously cloned and characterized. By means of candidate gene association mapping, we identified single-nucleotide polymorphisms (SNPs) in eight genes known to have key functions in starch-sugar interconversion, which were diagnostic for increased tuber starch and/or decreased sugar content and vice versa. Most positive or negative effects of SNPs on tuber-reducing sugar content were reproducible in two different collections of potato cultivars. The diagnostic SNP markers are useful for breeding applications. An allele of the plastidic starch phosphorylase PHO1a associated with increased tuber starch content was cloned as full-length cDNA and characterized. The PHO1a-HA allele has several amino acid changes, one of which is unique among all known starch/glycogen phosphorylases. This mutation might cause reduced enzyme activity due to impaired formation of the active dimers, thereby limiting starch breakdown. PMID:25081979

Schreiber, Lena; Nader-Nieto, Anna Camila; Schonhals, Elske Maria; Walkemeier, Birgit; Gebhardt, Christiane

2014-01-01

9

Comparative transcriptome analysis coupled to X-ray CT reveals sucrose supply and growth velocity as major determinants of potato tuber starch biosynthesis  

Microsoft Academic Search

BACKGROUND: Even though the process of potato tuber starch biosynthesis is well understood, mechanisms regulating biosynthesis are still unclear. Transcriptome analysis provides valuable information as to how genes are regulated. Therefore, this work aimed at investigating transcriptional regulation of starch biosynthetic genes in leaves and tubers of potato plants under various conditions. More specifically we looked at gene expression diurnally

Stephanus J Ferreira; Melanie Senning; Sophia Sonnewald; Petra-Maria Keßling; Ralf Goldstein; Uwe Sonnewald

2010-01-01

10

Regulation of sucrose and starch metabolism in potato tubers in response to short-term water deficit  

Microsoft Academic Search

.   To investigate the effect of water stress on carbon metabolism in growing potato tubers (Solanum tuberosum L.), freshly cut and washed discs were incubated in a range of mannitol concentrations corresponding to external water potential\\u000a between 0 and ?1.2 MPa. (i) Incorporation of [14C]glucose into starch was inhibited in water-stressed discs, and labeling of sucrose was increased. High glucose

Peter Geigenberger; Ralph Reimholz; Michael Geiger; Lucia Merlo; Vittoria Canale; Mark Stitt

1997-01-01

11

Field evaluation of transgenic potato plants expressing an antisense granule-bound starch synthase gene: increase of the antisense effect during tuber growth  

Microsoft Academic Search

Transgenic plants of a tetraploid potato cultivar were obtained in which the amylose content of tuber starch was reduced via antisense RNA-mediated inhibition of the expression of the gene encoding granule-bound starch synthase (GBSS). GBSS is one of the key enzymes in the biosynthesis of starch and catalyses the formation of amylose. The antisense GBSS genes, based on the full-length

Anja G. J. Kuipers; Wim J. J. Soppe; Evert Jacobsen; Richard G. F. Visser

1994-01-01

12

Effects of starches on the textural, rheological, and color properties of surimi-beef gels with microbial tranglutaminase.  

PubMed

In order to evaluate effects of starches (corn starch, potato starch, and tapioca starch) on the characteristics of surimi-beef gels with microbial transglutaminase, the cooking loss, gel strength, color and rheological properties of samples were investigated. Results demonstrated that starches gave negative effects on the cooking loss of surimi-beef gels. The gel with corn starch had the highest cooking loss while that with tapioca starch showed the lowest value. The gel with potato starch obtained the highest gel strength. During the sol-gel transitions, surimi-beef complexes with 3% corn starch exhibited the highest storage modulus value, while that with 3% tapioca starch had the lowest one. The addition of starch caused the increase of L* values of surimi-beef gels. Results showed that the excessive amount of starch resulted in the decrease in gel strength of surimi-beef gels. PMID:23273461

Zhang, Fenghui; Fang, Ling; Wang, Chenjie; Shi, Liu; Chang, Tong; Yang, Hong; Cui, Min

2013-03-01

13

Decreasing the Mitochondrial Synthesis of Malate in Potato Tubers Does Not Affect Plastidial Starch Synthesis, Suggesting That the Physiological Regulation of ADPglucose Pyrophosphorylase Is Context Dependent1[W][OA  

PubMed Central

Modulation of the malate content of tomato (Solanum lycopersicum) fruit by altering the expression of mitochondrially localized enzymes of the tricarboxylic acid cycle resulted in enhanced transitory starch accumulation and subsequent effects on postharvest fruit physiology. In this study, we assessed whether such a manipulation would similarly affect starch biosynthesis in an organ that displays a linear, as opposed to a transient, kinetic of starch accumulation. For this purpose, we used RNA interference to down-regulate the expression of fumarase in potato (Solanum tuberosum) under the control of the tuber-specific B33 promoter. Despite displaying similar reductions in both fumarase activity and malate content as observed in tomato fruit expressing the same construct, the resultant transformants were neither characterized by an increased flux to, or accumulation of, starch, nor by alteration in yield parameters. Since the effect in tomato was mechanistically linked to derepression of the reaction catalyzed by ADP-glucose pyrophosphorylase, we evaluated whether the lack of effect on starch biosynthesis was due to differences in enzymatic properties of the enzyme from potato and tomato or rather due to differential subcellular compartmentation of reductant in the different organs. The results are discussed in the context both of current models of metabolic compartmentation and engineering. PMID:23064409

Szecowka, Marek; Osorio, Sonia; Obata, Toshihiro; Araujo, Wagner L.; Rohrmann, Johannes; Nunes-Nesi, Adriano; Fernie, Alisdair R.

2012-01-01

14

Tuberous sclerosis  

MedlinePLUS

... new mutations, so there usually is no family history of tuberous sclerosis. This condition is one of a ... if: Either side of your family has a history of tuberous sclerosis You notice symptoms of tuberous sclerosis ...

15

Amylase activity in potato tubers  

Microsoft Academic Search

Summary  Amylase activity in extracts of sprouted tubers was optimised at final concentrations of soluble starch in the incubation\\u000a medium of 0.6–2.0 mg cm?3. Optimum pH was 6. The exclusion of calcium ions from extraction and incubation media did not result in reduced enzyme activity.\\u000a This, together with a shift in the absorption maximum of the starch-iodine complex almost identical to

Heather A. Ross; H. V. Davies

1987-01-01

16

Consequences of antisense RNA inhibition of starch branching enzyme activity on properties of potato starch  

Microsoft Academic Search

Antisense constructs containing cDNAs for potato starch branching enzyme (SBE) were introduced into potato (Solanum tuberosum L.). A population of transgenic plants were generated in which tuber SBE activity was reduced by between 5 and 98% of control values. No significant differences in amylose content or amylopectin branch length profiles of transgenic tuber starches were observed as a function of

Richard Safford; Steve A. Jobling; Chris M. Sidebottom; Roger J. Westcott; David Cooke; Karen J. Tober; Barbara H. Strongitharm; Alison L. Russell; Michael J. Gidley

1998-01-01

17

Color Formation in Wheat Starch Based Glucose Syrups and Use of Commercially Available and Laboratory?Prepared Agricultural Waste?based Activated Carbons for Decolorization  

Microsoft Academic Search

Glucose syrups were produced from wheat starch using ??amylase at 97°C for 45–90 min liquefaction times, followed by saccharification with amyloglucosidase at 60°C for 18 h to study the color formation. This was followed by decolorization studies using 0.25 to 1.00 g activated carbon per g of syrup of the commercially available NORIT and several activated carbons prepared from apricot stones and hazelnut shells

?pek Çelebi; N. Suzan Kincal

2007-01-01

18

Tubers and rhizome fragments as propagules: competence for vegetative reproduction in Equisetum arvense  

Microsoft Academic Search

Rhizome fragments (referred to as “fragments”) and tubers of Equisetum arvense L. were cultured in order to investigate their competence with respect to vegetative reproduction. The starch concentration of the fragments was lower than that of the tubers, but the initial growth of new individuals from these fragments was superior to that from tubers obtained from the same dry mass.

Yoshiaki Sakamaki; Yoshio Ino

2006-01-01

19

Physicochemical and binder properties of starch obtained from Cyperus esculentus.  

PubMed

The purpose of this study was to isolate starch from the tubers of Cyperus esculentus L. and evaluate its physicochemical and binder properties. Extraction of starch using sodium metabisulfite yielded 37 g of starch per 100 g of the tubers. Scanning electron microscopy indicated that Cyperus starch consists of oval to elliptical particles with a smooth surface. Cyperus starch demonstrates a narrow particle size distribution with a mean of 8.25 ?m. Cyperus starch conforms well to United States Pharmacopeia standards established for widely used starches like maize and potato. The X-ray powder diffraction pattern and moisture sorption profile of Cyperus starch were comparable to that of maize starch. Cyperus starch had lower swelling power than maize and potato starch, indicative of stronger associative forces within the granules. Carr's index and Hausner ratio indicate that Cyperus starch should have comparable flow properties with respect to maize and potato starch. Cyperus starch was employed as binder for the formulation of metronidazole tablets. Formulations containing 5%, 7.5%, and 10% Cyperus starch were compared with those containing 10% potato starch. At 10% binder concentration, the tablets containing Cyperus starch exhibited better hardness and negligible friability as compared with those with potato starch. Although the binder concentration had a significant effect on the disintegration time of the tablets, it did not seem to affect the dissolution profile. These results indicate that Cyperus starch provides excellent binding properties without compromising drug release characteristics and should be explored in pharmaceutical formulations. PMID:22350737

Manek, Rahul V; Builders, Philip F; Kolling, William M; Emeje, Martins; Kunle, Olobayo O

2012-06-01

20

Tuberous Sclerosis  

MedlinePLUS

... and surgery can remove any growths. If your child has developmental problems, occupational therapy can help. Most people who have tuberous sclerosis have a normal life span. Other Organizations ... Questions to Ask Your Doctor My child is having seizures. Does he or she have ...

21

Starch metabolism in Arabidopsis.  

PubMed

Starch is the major non-structural carbohydrate in plants. It serves as an important store of carbon that fuels plant metabolism and growth when they are unable to photosynthesise. This storage can be in leaves and other green tissues, where it is degraded during the night, or in heterotrophic tissues such as roots, seeds and tubers, where it is stored over longer time periods. Arabidopsis accumulates starch in many of its tissues, but mostly in its leaves during the day. It has proven to be a powerful genetic system for discovering how starch is synthesised and degraded, and new proteins and processes have been discovered. Such work has major significance for our starch crops, whose yield and quality could be improved by the application of this knowledge. Research into Arabidopsis starch metabolism has begun to reveal how its daily turnover is integrated into the rest of metabolism and adapted to the environmental conditions. Furthermore, Arabidopsis mutant lines deficient in starch metabolism have been employed as tools to study other biological processes ranging from sugar sensing to gravitropism and flowering time control. This review gives a detailed account of the use of Arabidopsis to study starch metabolism. It describes the major discoveries made and presents an overview of our understanding today, together with some as-yet unresolved questions. PMID:23393426

Streb, Sebastian; Zeeman, Samuel C

2012-01-01

22

Physicochemical and degradative properties of in-planta re-structured potato starch  

Microsoft Academic Search

Starch re-structured directly in potato tubers by antisense suppression of starch branching enzyme (SBE), granule bound starch synthase (GBSS) or glucan water dikinase (GWD) genes was studied with the aim at disclosing the effects on resulting physico-chemical and enzyme degradative properties. The starches were selected to provide a combined system with specific and extensive alterations in amylose and covalently esterified

Hetti Arachchige Mangalika Wickramasinghe; Andreas Blennow; Takahiro Noda

2009-01-01

23

Color  

NSDL National Science Digital Library

Using this project will expose you to concepts of color, color wheels, color combinations, and techniques of using color. Use the following links, follow the directions to define color terms, create color schemes and explore the use of color in creating designs. Color Scheme Generator 2 This site identifiesbasic terms related to color, using acolor wheeland making color schemes. Color Theory This site explains terminology of color. Color Theory Tutorial This site gives excellent examples and information about ...

Dent, Mrs.

2010-03-23

24

Changes in rheological properties and amylase activities of trifoliate yam, Dioscorea dumetorum, starch after harvest  

Microsoft Academic Search

Changes in rheological properties and amylase activities occurring in trifoliate yam, Dioscorea dumetorum, starch after harvest were investigated. Trifoliate yam tubers were harvested and stored under tropical ambient (28 °C) and cold room conditions (4 °C) for 12, 24 and 36 h. The D. dumetorum starches were extracted from the tubers under study and samples were evaluated for changes in their rheological

Emmanuel Ohene Afoakwa; Samuel Sefa-Dedeh

2002-01-01

25

Acid degradation of starch. The effect of acid and starch type  

Microsoft Academic Search

Starch from cereals (wheat, maize and finger millet) pulses (chick pea and green gram), tuber (potato) and root (tapioca) was modified with different acids (0.5N, 1.5h, 50°C). Molecular weight (number average, M?n) of these starches decreased after modification, H3PO4 causing the least and HCl and HNO3 the highest reduction. Gel permeation chromatography of native starches using Sepharose CL 4B gave

V. Singh; S. Z. Ali

2000-01-01

26

Subcellular pyrophosphate metabolism in developing tubers of potato ( Solanum tuberosum )  

Microsoft Academic Search

PPi has previously been implicated specifically in the co-ordination of the sucrose–starch transition and in the broader context of its role as co-factor in heterotrophic plant metabolism. In order to assess the compartmentation of pyrophosphate (PPi) metabolism in the potato tuber we analysed the effect of expressing a bacterial pyrophosphatase in the amyloplast of wild type tubers or in the

Eva M. Farré; Richard N. Trethewey; Alisdair R. Fernie; Lothar Willmitzer

2006-01-01

27

Investigating Starch  

NSDL National Science Digital Library

In this activity (on pages 10-15), learners investigate starch in human diets and how plants make starch (carbohydrates) to use as their food source. Testing with a dropper of iodine in Part One, learners discover that starch content differs from food to food. In Part Two, learners taste chewed and unchewed food and compare the starch content.

Museum, University O.; Nebraska Cooperative Extension 4-H Youth Development

2001-01-01

28

Physical and functional properties of arrowroot starch extrudates.  

PubMed

Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food. PMID:19323747

Jyothi, A N; Sheriff, J T; Sajeev, M S

2009-03-01

29

Morphological and molecular characterization of a spontaneously tuberizing potato mutant: an insight into the regulatory mechanisms of tuber induction  

PubMed Central

Background Tuberization in potato (Solanum tuberosum L.) represents a morphogenetic transition of stolon growth to tuber formation, which is under complex environmental and endogenous regulation. In the present work, we studied the regulatory mechanisms and the role of different morphogenetic factors in a newly isolated potato mutant, which exhibited spontaneous tuberization (ST). The ST mutant was characterized in detail at morphological, physiological and biochemical levels. Results Tuberization of the ST mutant grown in the soil was photoperiod-insensitive; predominantly sessile tubers formed directly from axillary buds even under continuous light. Single-node cuttings of the ST mutant cultured in vitro frequently formed tubers or basal tuber-like swellings instead of normal shoots under conditions routinely used for shoot propagation. The tuberization response of ST cuttings under light was dependent on sucrose, the concentration of which had to exceed certain threshold that inversely correlated with irradiance. Gibberellic acid prevented tuberization of ST cuttings, but failed to restore normal shoot phenotype and caused severe malformations. Carbohydrate analysis showed increased levels of both soluble sugars and starch in ST plants, with altered carbohydrate partitioning and metabolism. Comparative proteomic analysis revealed only a few differences between ST- and wild-type plants, primary amongst which seemed to be the absence of an isoform of manganese-stabilizing protein, a key subunit of photosystem II. Conclusion ST mutant exhibits complex developmental and phenotypic modifications, with features that are typical for plants strongly induced to tuberize. These changes are likely to be related to altered regulation of photosynthesis and carbohydrate metabolism rather than impaired transduction of inhibitory gibberellin or photoperiod-based signals. The effect of gibberellins on tuberization of ST mutant suggests that gibberellins inhibit tuberization downstream of the inductive effects of sucrose and other positive factors. PMID:19025587

Fischer, Lukas; Lipavska, Helena; Hausman, Jean-Francois; Opatrny, Zdenek

2008-01-01

30

Autism and Tuberous Sclerosis  

Microsoft Academic Search

The co-occurrence of autism spectrum disorder and tuberous sclerosis complex has been recognized for decades. The prevalence of tuberous sclerosis complex in the autism spectrum disorder population is 1 to 4%, whereas features of autism spectrum disorder are present in 25 to 50% of individuals with tuberous sclerosis complex. The underlying reason for this association might be a nonspecific disruption

Max Wiznitzer

2004-01-01

31

Tubers and rhizome fragments as propagules: competence for vegetative reproduction in Equisetum arvense.  

PubMed

Rhizome fragments (referred to as "fragments") and tubers of Equisetum arvense L. were cultured in order to investigate their competence with respect to vegetative reproduction. The starch concentration of the fragments was lower than that of the tubers, but the initial growth of new individuals from these fragments was superior to that from tubers obtained from the same dry mass. This superior growth was due to the large number of buds (grown from nodes) and aerial shoots on the fragments. The competence for vegetative reproduction depended on the relationship between the stored starch and the number of buds. PMID:16937024

Sakamaki, Yoshiaki; Ino, Yoshio

2006-11-01

32

Altering Trehalose-6-Phosphate Content in Transgenic Potato Tubers Affects Tuber Growth and Alters Responsiveness to Hormones during Sprouting1[C][W  

PubMed Central

Trehalose-6-phosphate (T6P) is a signaling metabolite that regulates carbon metabolism, developmental processes, and growth in plants. In Arabidopsis (Arabidopsis thaliana), T6P signaling is, at least in part, mediated through inhibition of the SNF1-related protein kinase SnRK1. To investigate the role of T6P signaling in a heterotrophic, starch-accumulating storage organ, transgenic potato (Solanum tuberosum) plants with altered T6P levels specifically in their tubers were generated. Transgenic lines with elevated T6P levels (B33-TPS, expressing Escherichia coli osmoregulatory trehalose synthesis A [OtsA], which encodes a T6P synthase) displayed reduced starch content, decreased ATP contents, and increased respiration rate diagnostic for high metabolic activity. On the other hand, lines with significantly reduced T6P (B33-TPP, expressing E. coli OtsB, which encodes a T6P phosphatase) showed accumulation of soluble carbohydrates, hexose phosphates, and ATP, no change in starch when calculated on a fresh weight basis, and a strongly reduced tuber yield. [14C]Glucose feeding to transgenic tubers indicated that carbon partitioning between starch and soluble carbohydrates was not altered. Transcriptional profiling of B33-TPP tubers revealed that target genes of SnRK1 were strongly up-regulated and that T6P inhibited potato tuber SnRK1 activity in vitro. Among the SnRK1 target genes in B33-TPP tubers, those involved in the promotion of cell proliferation and growth were down-regulated, while an inhibitor of cell cycle progression was up-regulated. T6P-accumulating tubers were strongly delayed in sprouting, while those with reduced T6P sprouted earlier than the wild type. Early sprouting of B33-TPP tubers correlated with a reduced abscisic acid content. Collectively, our data indicate that T6P plays an important role for potato tuber growth. PMID:21670224

Debast, Stefan; Nunes-Nesi, Adriano; Hajirezaei, Mohammad R.; Hofmann, Jörg; Sonnewald, Uwe; Fernie, Alisdair R.; Börnke, Frederik

2011-01-01

33

The effects of storage on starch characteristics and chip quality of Texas Irish potatoes  

E-print Network

of potato varieties at different storage temperatures and relative humidities 14 4. Changes in dry matter percent of potatoes stored at dii'ferent temperatures snd relative humitities 18 5. Potato starch grains. (4) Large starch grains (B) Small starch.... CHAPTER I INTRODUCTION The Irish potato is one of the more important agricultural products in the world. Starch, comprising some 65 to 80 percent of the dry weight of the potato tuber, is calorically the most important nutritional component. Since...

McDonald, Roy E

2012-06-07

34

COLORS!  

NSDL National Science Digital Library

In this project, students will learn about primary, secondary, and complementary colors. After exploring a few sites and participating in a few deep questions as a class, they will create an optical illusion using complimentary colors. Younger students who are learning this unit will need to do this activity with a parent or as a class with a teacher or aide. INTRODUCTION: Questions to discuss with the students: 1. What colors do you see in this room? 2. What are some jobs that use colors? An Artist? Decorator? ...

Sarah

2009-09-28

35

Plant age and genotype affect the bacterial community composition in the tuber rhizosphere of field-grown sweet potato plants.  

PubMed

The hypothesis that sweet potato genotypes containing different starch yields in their tuberous roots can affect the bacterial communities present in the rhizosphere (soil adhering to tubers) was tested in this study. Tuberous roots of field-grown sweet potato of genotypes IPB-149 (commercial genotype), IPB-052, and IPB-137 were sampled three and six months after planting and analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analysis of 16S rRNA genes PCR-amplified from total community DNA. The statistical analysis of the DGGE fingerprints showed that both plant age and genotypes influenced the bacterial community structure in the tuber rhizosphere. Pyrosequencing analysis showed that the IPB-149 and IPB-052 (both with high starch content) displayed similar bacterial composition in the tuber rhizosphere, while IPB-137 with the lowest starch content was distinct. In comparison with bulk soil, higher 16S rRNA gene copy numbers (qPCR) and numerous genera with significantly increased abundance in the tuber rhizosphere of IPB-137 (Sphingobium, Pseudomonas, Acinetobacter, Stenotrophomonas, Chryseobacterium) indicated a stronger rhizosphere effect. The genus Bacillus was strongly enriched in the tuber rhizosphere samples of all sweet potato genotypes studied, while other genera showed a plant genotype-dependent abundance. This is the first report on the molecular identification of bacteria being associated with the tuber rhizosphere of different sweet potato genotypes. PMID:24597529

Marques, Joana M; da Silva, Thais F; Vollu, Renata E; Blank, Arie F; Ding, Guo-Chun; Seldin, Lucy; Smalla, Kornelia

2014-05-01

36

In situ observation of crystallinity disruption patterns during starch gelatinization.  

PubMed

Twelve starches were isolated from the tuberous root of sweet potato, the rhizomes of lotus and yam, the tuber of potato, the corm of water chestnut, and the seeds of pea, bean, barley, wheat, lotus, water caltrop, and ginkgo. Their gelatinization processes were in situ viewed using a polarizing microscope in combination with a hot stage. Four patterns of crystallinity disruption during heating were proposed. The crystallinity disruption initially occurred on the proximal surface of the eccentric hilum, on the distal surface of the eccentric hilum, from the central hilum, or on the surface of the central hilum starch granule. The patterns of initial disruption on the distal surface of the eccentric hilum and on the surface of the central hilum starch were reported for the first time. The heterogeneous distribution of amylose in starch granule might partly explain the different patterns of crystallinity disruption and swelling during gelatinization. PMID:23218322

Cai, Canhui; Wei, Cunxu

2013-01-30

37

Effects of viruses and other potato diseases on chip color  

Microsoft Academic Search

Conclusions  Leaf roll and spindle tuber virus infected tubers can be processed into potato chips as light and uniform in color as those\\u000a of apparently healthy controls. Tubers from hills showing vine symptoms of mosaic and calico virus also made equally light\\u000a colored chips as the checks. Haywire and giant hill infected plants can be expected to produce tubers that will

H. W. Chapman; C. W. Frutchey

1960-01-01

38

Starch Slime  

NSDL National Science Digital Library

Learners mix liquid water with solid cornstarch. They investigate the slime produced, which has properties of both a solid and a liquid. When they press hard on the starch slime with their fingers, the slime acts like a solid. Starch in water is a suspension of solid particles in water. When learners leave the starch slime alone, it flows like a liquid. A great opportunity to discuss states of matter. This activity is currently used in the Nature of Matter Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.

Industry, Oregon M.

1997-01-01

39

Improved method for detection of starch hydrolysis  

SciTech Connect

A new starch hydrolysis detection method which does not rely on iodine staining or the use of color-complexed starch is described. A linear relationship was obtained with agar-starch plates when net clearing zones around colonies of yeasts were plotted against enzyme levels (semilogarithm scale) produced by the same yeast strains in liquid medium. A similar relationship between starch clearing zones and alpha-amylase levels from three different sources was observed. These observations suggest that the method is useful in mutant isolations, strain improvement programs, and the prediction of alpha-amylase activities in culture filtrates or column effluents. (Refs. 18).

Ohawale, M.R.; Wilson, J.J.; Khachatourians, G.G.; Ingledew, W.M.

1982-09-01

40

Changes in main nutrients and medicinal composition of Chinese yam (Dioscorea opposita) tubers during storage.  

PubMed

The changes in the main nutrient and medicinal components during the storage of the Chinese yam (Dioscorea opposita) tubers were studied. The harvested tubers were stored under ambient conditions (10 °C to 18 °C, 60 % to 80 % Relative Humidity) and cold temperature and packaged conditions (4 °C, 60 % to 65 % Relative Humidity) for 45 day. The allantoin, starch, total alcohol-soluble sugar, reducing sugar, protein, and moisture contents of the samples were evaluated. Their amylase activities were also investigated. Results of ambient conditions indicated that, during storage, moisture decreased by 67.96 % to 56.51 %, and total sugars, reducing sugars, and protein increased by 6.49 % to 9.81 %, 1.7 % to 2.27 %, and 13.02 % to 14.55 %, respectively. Starch and enzyme activities increased during the early days of storage and progressively decreased, and the content of allantoin changed in volatility. The changes were more significant at cold temperatures and packaged conditions than at ambient conditions. This result suggests that after-ripening occurred in the early stages of Chinese yam tubers, which positively affected the nutritional potential of the tubers by a marked increase in nutrients. Low-temperature sweetening greatly affects the nutritional potential of tubers by a series of complicated interactions between starch and sugars at 4 °C. PMID:25328193

Zhang, Zhidan; Gao, Wenyuan; Wang, Renfang; Huang, Luqi

2014-10-01

41

Tuberous Sclerosis Alliance  

MedlinePLUS

... celebration of our 40th anniversary. The Rare Epilepsy Network Registry (REN) will be opening for enrollment in about a month. Find a walk near you to help us Step Forward to Cure Tuberous Sclerosis Complex. Clinicians: Complete a new online CME activity featuring ...

42

Starch biosynthetic genes and enzymes are expressed and active in the absence of starch accumulation in sugar beet tap-root  

PubMed Central

Background Starch is the predominant storage compound in underground plant tissues like roots and tubers. An exception is sugar beet tap-root (Beta vulgaris ssp altissima) which exclusively stores sucrose. The underlying mechanism behind this divergent storage accumulation in sugar beet is currently not fully known. From the general presence of starch in roots and tubers it could be speculated that the lack in sugar beet tap-roots would originate from deficiency in pathways leading to starch. Therefore with emphasis on starch accumulation, we studied tap-roots of sugar beet using parsnip (Pastinaca sativa) as a comparator. Results Metabolic and structural analyses of sugar beet tap-root confirmed sucrose as the exclusive storage component. No starch granules could be detected in tap-roots of sugar beet or the wild ancestor sea beet (Beta vulgaris ssp. maritima). Analyses of parsnip showed that the main storage component was starch but tap-root tissue was also found to contain significant levels of sugars. Surprisingly, activities of four main starch biosynthetic enzymes, phosphoglucomutase, ADP-glucose pyrophosphorylase, starch synthase and starch branching enzyme, were similar in sugar beet and parsnip tap-roots. Transcriptional analysis confirmed expression of corresponding genes. Additionally, expression of genes involved in starch accumulation such as for plastidial hexose transportation and starch tuning functions could be determined in tap-roots of both plant species. Conclusion Considering underground storage organs, sugar beet tap-root upholds a unique property in exclusively storing sucrose. Lack of starch also in the ancestor sea beet indicates an evolved trait of biological importance. Our findings in this study show that gene expression and enzymatic activity of main starch biosynthetic functions are present in sugar beet tap-root during storage accumulation. In view of this, the complete lack of starch in sugar beet tap-roots is enigmatic. PMID:24758347

2014-01-01

43

Cortical tubers, cognition, and epilepsy in tuberous sclerosis.  

PubMed

Tuberous sclerosis complex is an autosomal-dominant genetic disorder characterized by hamartomatous growth in various organs. Patients who have this disorder exhibit a high rate of epilepsy and cognitive problems. We investigated number of tubers, location, seizure types, and cognitive outcome, and we analyzed the relationships among them in our tuberous sclerosis patients in the Comprehensive Epilepsy Program at the University of Alberta. We also examined the seizure outcome after tuber resection. Our study cohort included 24 patients with tuberous sclerosis complex. We obtained seizure history, electroencephalogram, and neuropsychologic parameters. Magnetic resonance imaging was used to examine tuber numbers and locations. Ten patients underwent surgical removal of tubers responsible for intractable epilepsy. A negative correlation was found between the number of tubers and intelligent quotient score. Epilepsy surgery led to freedom from seizures in this patient group. We demonstrated that the total number and location of cortical tubers play a significant role in the extent of mental retardation in patients with tuberous sclerosis complex. In addition, patients with intractable seizures and well-defined epileptic focus had excellent surgical outcome. PMID:21481739

Kassiri, Janani; Snyder, Thomas J; Bhargava, Ravi; Wheatley, B Matt; Sinclair, D Barry

2011-05-01

44

Purification and substrate specificity of peroxidase from sweet potato tubers  

Microsoft Academic Search

Previously the screening of tropical plants demonstrated a high peroxidase activity in sweet potato (Ipomoeabatatas) tubers. The major peroxidase pool is localized in peel. Using peel of sweet potato as a source, the sweet potato peroxidase (SPP) has been isolated and purified to homogeneity. The enzyme purification included homogenization, extraction of colored compounds and consecutive chromatographies on Phenyl-Sepharose and DEAE-Toyopearl.

J. Castillo Leon; I. S Alpeeva; T. A Chubar; I. Yu Galaev; E Csoregi; I. Yu Sakharov

2002-01-01

45

Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz).  

PubMed

In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,167 bp) was cloned into binary vectors to drive expression of the firefly luciferase gene. Cassava cultivar Adira 4 was transformed with this construct or a control construct in which the luciferase gene was cloned behind the 35S promoter. Luciferase activity was measured in leaves, stems, roots and tuberous roots. As expected, the 35S promoter induced luciferase activity in all organs at similar levels, whereas the GBSSI promoter showed very low expression in leaves, stems and roots, but very high expression in tuberous roots. These results show that the cassava GBSSI promoter is an excellent candidate to achieve tuberous root-specific expression in cassava. PMID:23132522

Koehorst-van Putten, Herma J J; Wolters, Anne-Marie A; Pereira-Bertram, Isolde M; van den Berg, Hans H J; van der Krol, Alexander R; Visser, Richard G F

2012-12-01

46

Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner  

ERIC Educational Resources Information Center

The procedure to produce standard curve for starch concentration measurement by image analysis using a color scanner and computer for data acquisition and color analysis is described. Color analysis is performed by a Visual Basic program that measures red, green, and blue (RGB) color intensities for pixels within the scanner image.

Matthews, Kurt R.; Landmark, James D.; Stickle, Douglas F.

2004-01-01

47

Differences in sucrose-to-starch metabolism of Solanum tuberosum and Solanum brevidens  

Microsoft Academic Search

Sucrose-to-starch metabolism of the tuberising species Solanum tuberosum and that of the non-tuberising Solanum brevidens was studied using in vitro stem cuttings cultured under tuber inducing conditions. The shoots growing from axillary buds of S. brevidens and the in vitro induced stolons and tubers of S. tuberosum were characterised with respect to their carbohydrate composition by measuring the glucose, fructose,

Zsófia Bánfalvi; Attila Molnár; Lóránt Lakatos; Holger Hesse; Rainer Höfgen

1999-01-01

48

Autism and Tuberous Sclerosis  

Microsoft Academic Search

Autism and pervasive developmental disorders (PDD) are common in tuberous sclerosis (TSC). The frequency of autism is about 25%, with 40–45% of TSC cases meeting criteria for autism or PDD. Among autistic populations, the frequency of TSC is 1–4% and perhaps as high as 8–14% among the subgroup of autistic individuals with a seizure disorder. Mental retardation (MR) and seizures,

Susan L. Smalley

1998-01-01

49

Tuber Storage Proteins  

PubMed Central

A wide range of plants are grown for their edible tubers, but five species together account for almost 90 % of the total world production. These are potato (Solanum tuberosum), cassava (Manihot esculenta), sweet potato (Ipomoea batatus), yams (Dioscorea spp.) and taro (Colocasia, Cyrtosperma and Xanthosoma spp.). All of these, except cassava, contain groups of storage proteins, but these differ in the biological properties and evolutionary relationships. Thus, patatin from potato exhibits activity as an acylhydrolase and esterase, sporamin from sweet potato is an inhibitor of trypsin, and dioscorin from yam is a carbonic anhydrase. Both sporamin and dioscorin also exhibit antioxidant and radical scavenging activity. Taro differs from the other three crops in that it contains two major types of storage protein: a trypsin inhibitor related to sporamin and a mannose?binding lectin. These characteristics indicate that tuber storage proteins have evolved independently in different species, which contrasts with the highly conserved families of storage proteins present in seeds. Furthermore, all exhibit biological activities which could contribute to resistance to pests, pathogens or abiotic stresses, indicating that they may have dual roles in the tubers. PMID:12730067

SHEWRY, PETER R.

2003-01-01

50

Novel candidate genes influencing natural variation in potato tuber cold sweetening identified by comparative proteomics and association mapping  

PubMed Central

Background Higher plants evolved various strategies to adapt to chilling conditions. Among other transcriptional and metabolic responses to cold temperatures plants accumulate a range of solutes including sugars. The accumulation of the reducing sugars glucose and fructose in mature potato tubers during exposure to cold temperatures is referred to as cold induced sweetening (CIS). The molecular basis of CIS in potato tubers is of interest not only in basic research on plant adaptation to environmental stress but also in applied research, since high amounts of reducing sugars affect negatively the quality of processed food products such as potato chips. CIS-tolerance varies considerably among potato cultivars. Our objective was to identify by an unbiased approach genes and cellular processes influencing natural variation of tuber sugar content before and during cold storage in potato cultivars used in breeding programs. We compared by two-dimensional polyacrylamide gel electrophoresis the tuber proteomes of cultivars highly diverse for CIS. DNA polymorphisms in genomic sequences encoding differentially expressed proteins were tested for association with tuber starch content, starch yield and processing quality. Results Pronounced natural variation of CIS was detected in tubers of a population of 40 tetraploid potato cultivars. Significant differences in protein expression were detected between CIS-tolerant and CIS-sensitive cultivars before the onset as well as during cold storage. Identifiable differential proteins corresponded to protease inhibitors, patatins, heat shock proteins, lipoxygenase, phospholipase A1 and leucine aminopeptidase (Lap). Association mapping based on single nucleotide polymorphisms supported a role of Lap in the natural variation of the quantitative traits tuber starch and sugar content. Conclusions The combination of comparative proteomics and association genetics led to the discovery of novel candidate genes for influencing the natural variation of quantitative traits in potato tubers. One such gene was a leucine aminopeptidase not considered so far to play a role in starch sugar interconversion. Novel SNP’s diagnostic for increased tuber starch content, starch yield and chip quality were identified, which are useful for selecting improved potato processing cultivars. PMID:23919263

2013-01-01

51

Colors, Colors?  

NSDL National Science Digital Library

In this activity related to the famous "Stroop Effect," learners explore how words influence what we see and how the brain handles "mixed messages." Learners read colored words and are asked to say the color of the word, not what the word says. Learners use a data table to keep track of where they have trouble reading the colors. They analyze this data by answering questions and drawing conclusions. Learners can also take this test using the online version.

Songstad, Susan

2009-01-01

52

REVIEW ARTICLE The diurnal metabolism of leaf starch  

E-print Network

Starch is a primary product of photosynthesis in leaves. In most plants, a large fraction of the carbon assimilated during the day is stored transiently in the chloroplast as starch for use during the subsequent night. Photosynthetic partitioning into starch is finely regulated, and the amount of carbohydrate stored is dependent on the environmental conditions, particularly day length. This regulation is applied at several levels to control the flux of carbon from the Calvin cycle into starch biosynthesis. Starch is composed primarily of branched glucans with an architecture that allows the formation of a semi-crystalline insoluble granule. Biosynthesis has been most intensively studied in non-photosynthetic starchstoring organs, such as developing seeds and tubers. Biosynthesis in leaves has received less attention, but recent reverse-genetic studies of Arabidopsis (thale cress) have produced data generally consistent with what is known for storage tissues. The pathway involves starch synthases, which elongate the glucan chains, and branching enzymes. Remarkably, enzymes that partially debranch glucans are also required for normal amylopectin synthesis. In the last decade, our understanding of starch breakdown in leaves has advanced considerably. Starch is hydrolysed to maltose and glucose at night via a pathway that requires recently discovered proteins in addition to well-known enzymes. These sugars are exported from the plastid to support sucrose synthesis, respiration and growth. In the present review we provide an overview of starch biosynthesis, starch structure and starch degradation in the leaves of plants. We focus on recent advances in each area and highlight outstanding questions.

Samuel C. Zeeman; Steven M. Smith; Alison M. Smith

53

The potato amylase inhibitor gene SbAI regulates cold-induced sweetening in potato tubers by modulating amylase activity.  

PubMed

Potato cold-induced sweetening (CIS) is critical for the postharvest quality of potato tubers. Starch degradation is considered to be one of the key pathways in the CIS process. However, the functions of the genes that encode enzymes related to starch degradation in CIS and the activity regulation of these enzymes have received less attention. A potato amylase inhibitor gene known as SbAI was cloned from the wild potato species Solanum berthaultii. This genetic transformation confirmed that in contrast to the SbAI suppression in CIS-resistant potatoes, overexpressing SbAI in CIS-sensitive potatoes resulted in less amylase activity and a lower rate of starch degradation accompanied by a lower reducing sugar (RS) content in cold-stored tubers. This finding suggested that the SbAI gene may play crucial roles in potato CIS by modulating the amylase activity. Further investigations indicated that pairwise protein-protein interactions occurred between SbAI and ?-amylase StAmy23, ?-amylases StBAM1 and StBAM9. SbAI could inhibit the activities of both ?-amylase and ?-amylase in potato tubers primarily by repressing StAmy23 and StBAM1, respectively. These findings provide the first evidence that SbAI is a key regulator of the amylases that confer starch degradation and RS accumulation in cold-stored potato tubers. PMID:24985879

Zhang, Huiling; Liu, Jun; Hou, Juan; Yao, Ying; Lin, Yuan; Ou, Yongbin; Song, Botao; Xie, Conghua

2014-09-01

54

Nitrogen and potassium fertilization of potatoes: Sugars and starch  

Microsoft Academic Search

Considerable evidence exists that both N and K influence potato (Solanum tuberosum L.) yields and quality. The impact of nutrients on tuber quality parameters under field conditions should be identified so\\u000a optimum management practices can be utilized. We evaluated the N and K fertilization by K-sources effects on concentrations\\u000a of nutrients, reducing sugars, sucrose and starch in the stem and

D. T. Westermann; D. W. James; T. A. Tindall; R. L. Hurst

1994-01-01

55

Ultrastructural Changes in Potato Tuber Pith Cells during Brown Center Development 1  

PubMed Central

Electron microscopy revealed that subjecting `Russet Burbank' potato (Solanum tuberosum L.) plants to 2 days of cool temperature growing conditions (18°C days/10°C nights) did not produce visible damage or changes in tuber pith tissue when compared to warm-grown tubers (23°C days/18°C nights). However, damage to some tuber pith cells was observed after 5 days of cool treatment. Eight days of cool treatment produced extensive alterations in cell structure. The cytoplasm of the cool-treated tuber pith cells had become highly vesiculated and there was evidence of complete destruction of amyloplast membranes and tonoplasts. In many cases the starch grains appeared to be undergoing hydrolysis suggesting total disruption of normal cell function. Sixteen days of cool treatment were sufficient to produce visible brown center development in all cool-grown tubers examined. Electron microscopy of these tissues revealed that, although some organelles were still present, the cytoplasm had become extremely vesiculated and lacked any resemblance to that of tissue from warm-grown tubers. Gross, irregular thickening of cell walls was also detected. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:16664768

Van Denburgh, Roy W.; Hiller, Larry K.; Koller, David C.

1986-01-01

56

Physicochemical, morphological, and rheological characterization of Xanthosoma robustum Lego-like starch.  

PubMed

This work presents the physicochemical and pasting characterization of isolated mafafa starch and mafafa flour (Xanthosoma robustum). According to SEM images of mafafa starches in the tuber, these starches form Lego-like shaped structures with diameters between 8 and 35 ?m conformed by several starch granules of wedge shape that range from 2 to 7 ?m. The isolated mafafa starch is characterized by its low contents of protein, fat, and ash. The starch content in isolated starch was found to be 88.58% while the amylose content obtained was 35.43%. X-ray diffraction studies confirm that isolated starch is composed mainly by amylopectin. These results were confirmed by differential scanning calorimetry and thermo gravimetric analysis. This is the first report of the molecular parameters for mafafa starch: molar mass that ranged between 2×10(8) and 4×10(8) g/mol, size (Rg) value between 279 and 295 nm, and molecular density value between 9.2 and 9.7 g/(mol nm(3)). This study indicates that mafafa starch shows long chains of amylopectin this fact contributes to higher viscosity development and higher gel stability. The obtained gel phase is transparent in the UV-vis region. The viscosity, gel stability and optical properties suggest that there is potential for mafafa starch applications in the food industry. PMID:24463263

Londoño-Restrepo, Sandra M; Rincón-Londoño, Natalia; Contreras-Padilla, Margarita; Acosta-Osorio, Andrés A; Bello-Pérez, Luis A; Lucas-Aguirre, Juan C; Quintero, Víctor D; Pineda-Gómez, Posidia; del Real-López, Alicia; Rodríguez-García, Mario E

2014-04-01

57

Heterologous expression of AtPAP2 in transgenic potato influences carbon metabolism and tuber development.  

PubMed

Changes in carbon flow and sink/source activities can affect floral, architectural, and reproductive traits of plants. In potato, overexpression (OE) of the purple acid phosphatase 2 of Arabidopsis (AtPAP2) resulted in earlier flowering, faster growth rate, increased tubers and tuber starch content, and higher photosynthesis rate. There was a significant change in sucrose, glucose and fructose levels in leaves, phloem and sink biomass of the OE lines, consistent with an increased expression of sucrose transporter 1 (StSUT1). Furthermore, the expression levels and enzyme activity of sucrose-phosphate synthase (SPS) were also significantly increased in the OE lines. These findings strongly suggest that higher carbon supply from the source and improved sink strength can improve potato tuber yield. PMID:25173632

Zhang, Youjun; Sun, Feng; Fettke, Joerg; Schöttler, Mark Aurel; Ramsden, Lawrence; Fernie, Alisdair R; Lim, Boon Leong

2014-10-16

58

Cerebellar pathology in tuberous sclerosis.  

PubMed

Cerebellar involvement in tuberous sclerosis is rare and generally nonsymptomatic. The authors describe a cerebellar tuber in a 5-year-old boy with tuberous sclerosis. A CT scan at age 2 years showed the characteristic cortical, white matter, and subependymal lesions of tuberous sclerosis. At 5 years, when the patient was symptomatic with ataxia, the CT and MRI scans revealed additionally the presence of a right cerebellar enhancing lesion with edema. A total surgical resection was undertaken. The cerebellar lesion was very firm and demonstrated marked disorganization of neuronal architecture in the cerebellar folia, with bizzare ectopic neurons in the molecular and granule cell layers and white matter, along with calcification, gliosis, and Rosenthal fiber deposition. Balloon cells with glassy, pale, eosinophilic cytoplasm were also present. There was a marked loss of myelin in the white matter, with significant vacuolation and gliosis. Electron microscopy documented abundant lysosomal inclusions, prominent rough endoplasmic reticulum and Golgi complexes, microtubules, intermediate filaments, and synaptic contacts. While there is much speculation as to the precise nature of cerebellar pathology in tuberous sclerosis, this case demonstrates conclusively that the cerebellar lesions reflect anomolous neuronal development and migration akin to supratentorial lesions and can rarely be symptomatic. PMID:9805358

Jay, V; Edwards, V; Musharbash, A; Rutka, J T

1998-01-01

59

Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions  

NASA Technical Reports Server (NTRS)

Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

Cook, Martha E.; Croxdale, Judith G.; Tibbitts, T. W. (Principal Investigator)

2003-01-01

60

Regulation of potato tuber sprouting.  

PubMed

Following tuber induction, potato tubers undergo a period of dormancy during which visible bud growth is inhibited. The length of the dormancy period is under environmental, physiological and hormonal control. Sucrose availability is one prerequisite for bud break. In the absence of sucrose, no bud break occurs. Thus, sucrose is likely to serve as nutrient and signal molecule at the same time. The mode of sucrose sensing is only vaguely understood, but most likely involves trehalose-6-phosphate and SnRK1 signalling networks. This conclusion is supported by the observation that ectopically manipulation of trehalose-6-phosphate levels influences the length of the dormancy period. Once physiological competence is achieved, sprouting is controlled by the level of phytohormones. Two phytohormones, ABA and ethylene, are supposed to suppress tuber sprouting; however, the exact role of ethylene remains to be elucidated. Cytokinins and gibberellins are required for bud break and sprout growth, respectively. The fifth classical phytohormone, auxin, seems to play a role in vascular development. During the dormancy period, buds are symplastically isolated, which changes during bud break. In parallel to the establishment of symplastic connectivity, vascular tissue develops below the growing bud most likely to support the outgrowing sprout with assimilates mobilised in parenchyma cells. Sprouting leads to major quality losses of stored potato tubers. Therefore, control of tuber sprouting is a major objective in potato breeding. Although comparative transcriptome analysis revealed a large number of genes differentially expressed in growing versus dormant buds, no master-regulator of potato tuber sprouting has been identified so far. PMID:24100410

Sonnewald, Sophia; Sonnewald, Uwe

2014-01-01

61

$gamma$RAY PROCESSING OF RICE. (I.) THE EFFECT OF $gamma$IRRADIATION ON IMPORTED RICE STARCH  

Microsoft Academic Search

A study of the effect of gamma irradiation on imported rice starch ; showed that the intrinsic viscosity and blue value of starch-iodine color ; reaction decreased, while the reducing power, alkali liability number, and ; digestibility increased. A change in the viscogram curve was also noted. Gamma ; irradiation degraded the straight chain components of the imported rice starch

Takaoka

1960-01-01

62

Starch Metabolism in Leaves  

Microsoft Academic Search

Starch is a carbohydrate reserve used by many higher plants. Transitory starch is synthesized in the chloroplasts of higher\\u000a plants both as an overflow for newly-assimilated carbon and as a reserve of carbohydrate for periods of darkness when photosynthesis\\u000a is not possible. Starch is present in the chloroplast as insoluble granules consisting of two types of glucose polymer: amylopectin\\u000a and

Richard N. Trethewey; Alison Smith

63

Synthesis of Rosin Acid Starch Catalyzed by Lipase  

PubMed Central

Rosin, an abundant raw material from pine trees, was used as a starting material directly for the synthesis of rosin acid starch. The esterification reaction was catalyzed by lipase (Novozym 435) under mild conditions. Based on single factor experimentation, the optimal esterification conditions were obtained as follows: rosin acid/anhydrous glucose unit in the molar ratio 2?:?1, reaction time 4?h at 45°C, and 15% of lipase dosage. The degree of substitution (DS) reaches 0.098. Product from esterification of cassava starch with rosin acid was confirmed by FTIR spectroscopy and iodine coloration analysis. Scanning electron microscopy and X-ray diffraction analysis showed that the morphology and crystallinity of the cassava starch were largely destroyed. Thermogravimetric analysis indicated that thermal stability of rosin acid starch decreased compared with native starch. PMID:24977156

Lin, Rihui; Li, He; Long, Han; Su, Jiating; Huang, Wenqin

2014-01-01

64

Ahipa ( Pachyrhizus ahipa [Wedd.] Parodi): an alternative legume crop for sustainable production of starch, oil and protein  

Microsoft Academic Search

Ahipa (Pachyrhizus ahipa [Wedd.] Parodi) is a tuberous root producing legume which can be used for the production of raw materials such as starch, sugar and protein in a sustainable agriculture system. In this study, we studied root and pod production of available landraces grown at two different locations for making preliminary yield assessments and analyzed root and seed composition

E. O Leidi; R Sarmiento; D. N Rodr??guez-Navarro

2003-01-01

65

Regulation of Starch Biosynthesis  

Microsoft Academic Search

Transient or long-term storage of photosynthate in starch granules can be considered as the last step of eukaryotic photosynthesis. Storage of glucose into structures larger than the size of an individual bacterial cell is slowly uncovering as an exceedingly complex mechanism, which distinguishes the chloroplast from its ancestor prochloron or cyanobacterial-like cell. There is no question that starch biosynthesis has

Steven G. Ball

66

Preparation and characterization of new and improved soluble-starches, -amylose, and -amylopectin by reaction with benzaldehyde/zinc chloride.  

PubMed

Seven different starches from potato, rice, maize, waxymaize, amylomaize-VII, shoti, and tapioca, and potato amylose and potato amylopectin have been reacted with benzaldehyde, catalyzed by ZnCl(2), to give new water-soluble starches and water soluble-amylose and soluble-amylopectin. In contrast to the native starches, aqueous solutions of the modified starches could not be precipitated with 2-, 3-, or 4-volumes of ethanol. ?-Amylase gave no reaction with the modified starches, in contrast to the native starches, indicating that the modification occurred exclusively at the nonreducing-ends, giving 4,6-benzylidene-D-glucopyranose at the nonreducing-ends. Reactions of ?-amylase with native and modified potato and rice starches gave a decrease in the triiodide blue color and an increase in the reducing-value that were similar for the native- and modified-starches, indicating the modified starches had not been significantly altered by the modification. The benzaldehyde-modified starches and benzaldehyde-modified potato amylose and potato amylopectin components, therefore, have a starch structure very much like their native counterparts, in contrast to the Lintner, Small, and the alcohol/acid-hydrolyzed soluble-starches that have undergone acid hydrolysis. The benzaldehyde-modified starches and starch components have significantly higher water solubility than their native counterparts even though the structures of the modified starches had only been slightly altered from the structures of their native counterparts. They all gave crystal-clear solutions that did not retrograde. PMID:22055814

Johnston, David A; Mukerjea, Rupendra; Robyt, John F

2011-12-13

67

New Perspectives on Starch and Starch Derivatives for Snack Applications  

Microsoft Academic Search

In nature, starch is available in an abundance, surpassed only by cellulose as a naturally occurring organic compound. Starch is located in many parts of green leafed plants, such as roots, stems, seeds, and fruits. Starch serves as food for energy during dormancy and germination in plants and functions similarly for humans and animals. However, uses for starch extend far

D. P. Huang

68

Influence of oxidized starch on the properties of thermoplastic starch.  

PubMed

Thermoplastic starch was prepared by adding oxidized starches and glycerol together into starch. The addition of oxidized starch improved the rheological properties and also increased the toughness of thermoplastic starch. Compared with TPS30, the elongation at break increased from 126.8% to 152.5% when 5wt% OS 117% was added. Good compatibility of thermoplastic starch between the matrix and oxidized starch was confirmed by SEM. The addition of oxidized starch lowered the storage modulus and glass transition temperature (Tg) of thermoplastic starch, decreasing Tg from 34.1 to 30°C when 10 wt% OS117% was added. The thermal stability of blending was improved by adding oxidized starches, i.e. when 5 wt% OS70% was added, T5% increased from 134 to 156°C. PMID:23688492

Zhang, Yu-Rong; Wang, Xiu-Li; Zhao, Guo-Ming; Wang, Yu-Zhong

2013-07-01

69

Glioma-like proliferation within tissues excised as tubers in patients with tuberous sclerosis complex  

Microsoft Academic Search

We describe diffuse glioma-like infiltrates in excised tubers in five out of forty Tuberous sclerosis complex (TSC) patients\\u000a undergoing excision of a tuber at our institution within the last 10 years. All patients presented with refractory seizures.\\u000a Resection specimens from four patients had the pathognomonic histologic features of neuroglial hamartomas (tubers) and in\\u000a one case there was cortical microdysgenesis lacking cells

Ingeborg Fischer; Clare Cunliffe; Robert J. Bollo; Howard L. Weiner; Orrin Devinsky; Martha-Eugenia Ruiz-Tachiquin; Toni Venuto; Alexander Pearlman; Luis Chiriboga; Robert J. Schneider; Harry Ostrer; Douglas C. Miller

2008-01-01

70

Lymphangioleiomyomatosis and Tuberous Sclerosis Complex  

Microsoft Academic Search

Lymphangioleiomyomatosis (LAM) is a rare multisystemic disease of women of child-bearing age and affects mainly the lungs,\\u000a promoting cystic destruction of lung parenchyma or leading to abdominal tumor formation (e.g., angiomyolipomas, lymphangioleiomyomas).\\u000a LAM can arise sporadically or in association with tuberous sclerosis complex (TSC), an autosomal inherited syndrome characterized\\u000a by hamartoma-like tumor growth and pathologic features that are distinct from

Dimitrios Chorianopoulos; Grigoris Stratakos

2008-01-01

71

Characterization of starch nanoparticles  

NASA Astrophysics Data System (ADS)

Nanomaterials already attract great interest because of their potential applications in technology, food science and medicine. Biomaterials are biodegradable and quite abundant in nature, so they are favoured over synthetic polymer based materials. Starch as a nontoxic, cheap and renewable raw material is particularly suitable for preparation of nanoparticles. In the paper, the structure and some physicochemical properties of potato and cassava starch particles of the size between 50 to 100 nm, obtained by mechanical treatment of native starch, were presented. We demonstrated, with the aim of the Scanning Electron Microscopy (SEM) and the non-contact Atomic Force Microscopy (nc-AFM), that the shape and dimensions of the obtained nanoparticles both potato and cassava starch fit the blocklets - previously proposed as basic structural features of native starch granules. This observation was supported by aqueous solubility and swelling power of the particles as well as their iodine binding capacity similar to those for amylopectin-type short branched polysaccharide species. Obtained results indicated that glycosidic bonds of the branch linkage points in the granule amorphous lamellae might be broken during the applied mechanical treatment. Thus the released amylopectin clusters could escape out of the granules. The starch nanoparticles, for their properties qualitatively different from those of native starch granules, could be utilized in new applications.

Szymo?ska, J.; Targosz-Korecka, M.; Krok, F.

2009-01-01

72

Influence of starch structure and starch granule-associated proteins on rheological properties of starch pastes  

Microsoft Academic Search

Components of starch granules were investigated to reveal the roles of components in the overall rheology of starch pastes and gels. In a reconstitution study, replacement of insoluble starch with soluble starch decreased the viscosity of pastes and reduced the stickiness of gels. Rice amylopectin fine structure was found to significantly correlate with paste breakdown. Proportion of long chains of

Xian-Zhong Han

2001-01-01

73

MRI findings reveal three different types of tubers in patients with tuberous sclerosis complex  

PubMed Central

Cortical tubers are very common in tuberous sclerosis complex (TSC) and widely vary in size, appearance and location. The relationship between tuber features and clinical phenotype is unclear. The aim of the study is to propose a classification of tuber types along a spectrum of severity, using magnetic resonance imaging (MRI) characteristics in 35 patients with TSC and history of epilepsy, and to investigate the relationship between tuber types and genetics, as well as clinical manifestations. Three types of tubers were identified based on the MRI signal intensity of their subcortical white matter component. (1) Tubers Type A are isointense on volumetric T1 images and subtly hyperintense on T2 weighted and fluid-attenuated inversion recovery (FLAIR); (2) Type B are hypointense on volumetric T1 images and homogeneously hyperintense on T2 weighted and FLAIR; (3) Type C are hypointense on volumetric T1 images, hyperintense on T2 weighted, and heterogeneous on FLAIR characterized by a hypointense central region surrounded by a hyperintense rim. Based on the dominant tuber type present, three distinct patient groups were also identified: Patients with Type A tuber dominance have a milder phenotype. Patients with Type C tuber dominance have more MRI abnormalities such as subependymal giant cell tumors, and were more likely to have an autism spectrum disorder, a history of infantile spasms, and a higher frequency of epileptic seizures, compared to patients who have a dominance in Type B tubers, and especially to those with a Type A dominance. PMID:20352250

Gallagher, Anne; Grant, Ellen P.; Madan, Neel; Jarrett, Delma Y.; Lyczkowski, David A.

2011-01-01

74

Laser treatment of angiofibromas in tuberous sclerosis.  

PubMed

Tuberous sclerosis complex is an autosomal dominant disorder that can cause nonmalignant hamartomas in any organ. Angiofibromas are the most disturbing marker of the disease because they are conspicuously present on the face. We report the case of a 15-year-old girl affected by tuberous sclerosis, whose facial angiofibromas were satisfactorily treated by a green light vascular laser (532 nm). PMID:25336102

Pignatti, M; Spaggiari, A; Sala, P; Loschi, P; Fiumana, E; Faggioli, R

2014-12-01

75

Production of Cyclodextrins by CGTase from Bacillus clausii Using Different Starches as Substrates  

NASA Astrophysics Data System (ADS)

Cyclodextrins (CDs) are cyclic oligasaccharides composed by d-glucose monomers joined by ?-1,4-d glicosidic linkages. The main types of CDs are ?-, ?- and ?-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a ?-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for ?/?/?. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

Alves-Prado, H. F.; Carneiro, A. A. J.; Pavezzi, F. C.; Gomes, E.; Boscolo, M.; Franco, C. M. L.; da Silva, R.

76

Starch mutants of Chlamydomonas  

SciTech Connect

Wild type Chlamydomonas accumulates starch and triglycerides when grown under nitrogen limiting conditions. Toward elucidation of the mechanisms for control of starch biosynthesis, we isolated mutants impaired int he accumulation of storage carbohydrates. Chlamydomonas reinhardtii (strain ya-12) was mutagenized by UV irradiation and colonies were screened by iodine staining after growth in darkness. Mutants, denoted ais for altered in iodine staining, have been characterized by electron microscopy and assays for starch synthease, ADPG-pyrophosphorylase, phosphoglucose isomerase (PGI), phosphoglucomutase and fructose 1,6-bisphosphatase, and amylase activities. Transcript analysis of wild type and mutant RNAs with PGI, ADPG-pyrophosphorylase, and waxy probes have also been carried out. No deficiencies of any of these components have been detected. Furthermore, long-term cultures of ya-12 and ais-1d in nitrogen-limited chemostats have been studied; starch also does not accumulate in ais-1d under these conditions. Thus, the lesion affects an essential factor of unknown identity that is required for starch synthesis.

Berry-Lowe, S.L.; Schmidt, G.W. (Univ. of Georgia, Athens (USA))

1990-05-01

77

Metabolomic analysis of the potato tuber life cycle  

Microsoft Academic Search

An analysis of the potato (Solanum tuberosum L.) tuber life cycle has been completed using a range of mass-spectrometry (MS) based approaches. Six stages have been examined\\u000a which included developing and mature tubers, sprouting mature tubers and mature tubers stored at 5 or 10°C. The impact of\\u000a excising developing tubers from the mother plant (source-sink manipulation) was also determined. Data

L. V. T. Shepherd; C. A. Alexander; J. A. Sungurtas; J. W. McNicol; D. Stewart; H. V. Davies

2010-01-01

78

Specialty starches for snack foods  

Microsoft Academic Search

Specialty starches in snack foods serve as functional ingredients, contributing to desirable attributes such as increased expansion, improved crispness, reduced oil pick up and better overall eating quality. Starch-based coatings and adhesives can replace fat or oil in low-fat baked snacks. Dry hot melt starch-based adhesives are cost-effective tacking agents, while resistant starch provides high fiber nutritional claims for snack

M. G. Sajilata; Rekha S. Singhal

2005-01-01

79

Genetics Home Reference: Tuberous sclerosis complex  

MedlinePLUS

... are also common beginning in childhood. Tuberous sclerosis complex often affects the brain, causing seizures, behavioral problems such as hyperactivity and aggression, and intellectual disability or learning problems. Some affected children have the characteristic features ...

80

High-Resolution Metabolic Phenotyping of Genetically and Environmentally Diverse Potato Tuber Systems. Identification of Phenocopies  

PubMed Central

We conducted a comprehensive metabolic phenotyping of potato (Solanum tuberosum L. cv Desiree) tuber tissue that had been modified either by transgenesis or exposure to different environmental conditions using a recently developed gas chromatography-mass spectrometry profiling protocol. Applying this technique, we were able to identify and quantify the major constituent metabolites of the potato tuber within a single chromatographic run. The plant systems that we selected to profile were tuber discs incubated in varying concentrations of fructose, sucrose, and mannitol and transgenic plants impaired in their starch biosynthesis. The resultant profiles were then compared, first at the level of individual metabolites and then using the statistical tools hierarchical cluster analysis and principal component analysis. These tools allowed us to assign clusters to the individual plant systems and to determine relative distances between these clusters; furthermore, analyzing the loadings of these analyses enabled identification of the most important metabolites in the definition of these clusters. The metabolic profiles of the sugar-fed discs were dramatically different from the wild-type steady-state values. When these profiles were compared with one another and also with those we assessed in previous studies, however, we were able to evaluate potential phenocopies. These comparisons highlight the importance of such an approach in the functional and qualitative assessment of diverse systems to gain insights into important mediators of metabolism. PMID:11706160

Roessner, Ute; Willmitzer, Lothar; Fernie, Alisdair R.

2001-01-01

81

Sampling potato tubers to determine peel loss  

Microsoft Academic Search

A simple marker was fabricated for the purpose of rapidly labeling tubers that are to be used for determining the amount of\\u000a peel loss. The effect of tuber size and shape on quantity of peel removed, and its significance to continuous in-plant monitoring\\u000a of peel loss, is discussed. A standardized peel removal testing procedure for plant use is described.

M. L. Weaver; K. C. Ng; C. C. Huxsoll

1979-01-01

82

Physicochemical, rheological and structural characteristics of starch in maize tortillas.  

PubMed

Fresh and stored maize (white and blue) tortillas were evaluated for physicochemical, rheological and structural characteristics assessed by calorimetry, x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, dynamic viscoelastic tests, and high-performance size-exclusion chromatography. Two endotherms were found in studies of fresh and stored tortillas. The low temperature endotherm (50-56 degrees C) was due to reorganized (retrograded) amylopectin, while the high temperature endotherm (105-123 degrees C) was attributed to retrograded amylose. The enthalpy value for the lower temperature transition was minor than that of the high temperature transition. Fresh tortillas showed an amorphous starch arrangement by x-ray diffraction study. Stored samples showed the presence of peaks at 2theta = 17 masculine and 23 masculine, indicating re-crystallization of starch components. FTIR results confirmed the development of higher levels of starch crystals during storage. Differences in the viscoelastic parameters were also observed between fresh and stored samples. At the longest storage times, white tortillas were more rigid than blue tortillas. Molar mass values for starch increased for both white and blue tortillas as storage time progressed, though relatively higher values were obtained for white tortillas. More starch reorganization occurred in white tortillas, in accordance to calorimetric, x-ray diffraction, FTIR and rheological results. These results corroborate that changes occurring in tortillas during storage are related to reorganization of starch components, and the maize variety more than the color plays an important role. PMID:20396953

Hernández-Uribe, Juan P; Ramos-López, Gonzalo; Yee-Madeira, Hernani; Bello-Pérez, Luis A

2010-06-01

83

Tuberous Sclerosis Complex Diagnostic Criteria Update: Recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference  

PubMed Central

BACKGROUND Tuberous sclerosis complex is highly variable in clinical presentation and findings. Disease manifestations continue to develop over the lifetime of an affected individual. Accurate diagnosis is fundamental to implementation of appropriate medical surveillance and treatment. Although significant advances have been made in the past 15 years in the understanding and treatment of tuberous sclerosis complex, current clinical diagnostic criteria have not been critically evaluated or updated since the last clinical consensus conference in 1998. METHODS The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important diagnostic implications and was charged with reviewing prevalence and specificity of disease-associated clinical findings and their impact on suspecting and confirming the diagnosis of tuberous sclerosis complex. RESULTS Clinical features of tuberous sclerosis complex continue to be a principal means of diagnosis. Key changes compared with 1998 criteria are the new inclusion of genetic testing results and reducing diagnostic classes from three (possible, probable, and definite) to two (possible, definite). Additional minor changes to specific criterion were made for additional clarification and simplification. CONCLUSIONS The 2012 International Tuberous Sclerosis Complex Diagnostic Criteria provide current, updated means using best available evidence to establish diagnosis of tuberous sclerosis complex in affected individuals. PMID:24053982

Northrup, Hope; Krueger, Darcy A.

2014-01-01

84

Effect of tuber skin on the thermal properties of whole tubers of potato and sweet potato  

NASA Astrophysics Data System (ADS)

Temperature-dependent thermal coefficients of mathematical models of the postharvest storage process play an important role in determining the models accuracy. Thermal properties of tubers under storage available in literature are generally of those in semi processed form (skinless) such as those having undergone peeling, dicing and cutting actions. This study investigates the effect of tuber skin on the thermal properties of whole tubers of potato and sweet potato. A direct approach was used to measure the tubers' density and thermal conductivity and thermal diffusivity by the transient heat transfer method. Indirect approach was used to measure the tubers' specific heat. Experimental data were used to develop empirical models of the thermal coefficients as a function of temperature. Results of the study should find great use in the modeling of potato and sweet potato storage process.

Oluwo, A. A.; Khan, R. M.; Salami, M. J. E.

2013-12-01

85

Starch biosynthesis in cereal endosperm.  

PubMed

Stored starch generally consists of two d-glucose homopolymers, the linear polymer amylose and a highly branched glucan amylopectin that connects linear chains. Amylopectin structurally contributes to the crystalline organization of the starch granule in cereals. In the endosperm, amylopectin biosynthesis requires the proper execution of a coordinated series of enzymatic reactions involving ADP glucose pyrophosphorylase (AGPase), soluble starch synthase (SS), starch branching enzyme (BE), and starch debranching enzyme (DBE), whereas amylose is synthesized by AGPase and granule-bound starch synthase (GBSS). It is highly possible that plastidial starch phosphorylase (Pho1) plays an important role in the formation of primers for starch biosynthesis in the endosperm. Recent advances in our understanding of the functions of individual enzyme isoforms have provided new insights into how linear polymer chains and branch linkages are synthesized in cereals. In particular, genetic analyses of a suite of mutants have formed the basis of a new model outlining the role of various enzyme isoforms in cereal starch production. In our current review, we summarize the recent research findings related to starch biosynthesis in cereal endosperm, with a particular focus on rice. PMID:20400324

Jeon, Jong-Seong; Ryoo, Nayeon; Hahn, Tae-Ryong; Walia, Harkamal; Nakamura, Yasunori

2010-06-01

86

Apple Maturity Protocol Tests for apple flesh firmness and starch conversion are important tools for monitoring crop  

E-print Network

and should not be used in composts or as animal feed. Testing procedure for starch conversion Cut the applesApple Maturity Protocol Tests for apple flesh firmness and starch conversion are important tools and the blue color is not produced. Pressure testing for fruit firmness Standard mechanical pressure gauges

87

BIODEGRADABLE PLASTICS FROM CASSAVA STARCH IN THAILAND  

Microsoft Academic Search

The paper reviews the role of starch and biodegradable plastics production in Thailand, emphasizing the potential contribution of cassava starch in these products. Types of biodegradable plastics and their manufacturing processes are described. The major types of biodegradable plastics discussed are directly-expanded starch products and various starch-polymer blends (PCL, PLA, PVA and PHA). Research focusing on cassava starch incorporation into

Klanarong Sriroth; Rungsima Chollakup; Kuakoon Piyachomkwan; Christopher G. Oates

88

Tuberous sclerosis, deep vein thrombosis and lack of C and S proteins: A case report  

PubMed Central

Introduction: Tuberous sclerosis, an autosomal dominant disorder, is characterized by hamartomas in different organs of body. Kidney involvement is quite common in this disorder and sometimes it is accompanied by adult polycystic kidney disease. Case: A 46-year-old woman who was being treated for adult polycystic kidney disease and systemic hypertension was admitted to this hospital because of acute lower limb edema. Color Doppler sonography study showed deep vein thrombosis of lower limbs and also left iliac vein. Despite the initiation of hourly heparin infusion, the patient involved by pulmonary emboli on the 2ndday of admission. Lab tests revealed protein C and S deficiency. The patient had already experienced episodes of pneumothorax too. Cutaneous lesions due to sebaceous adenoma were seen on her cheeks, nose and neck. She had also periungual fibroma suggestive of tuberous sclerosis. Conclusion: Although, according to our patient with both tuberous sclerosis and protein C and S deficiency, a significant relation between these two diseases, cannot confirmed, however, evaluation of other patients who have tuberous sclerosis can help to confirm or rule out this relation.

Beladi-Mousavi, Seyed Seifollah; Zeraati, Abbasali; Sharifipour, Farzaneh; Naghibi, Masih; Kalani, Farnaz; Moussavinik, Sara; Beladi-Mousavi, Marzieh

2012-01-01

89

Engineering starch accumulation by manipulation of phosphate metabolism of starch.  

PubMed

A new understanding of leaf starch degradation has emerged in the last 10 years. It has been shown that starch phosphorylation and dephosphorylation are critical components of this process. Glucan, water dikinase (GWD) (and phosphoglucan, water dikinase) adds phosphate to starch, and phosphoglucan phosphatase (SEX4) removes these phosphates. To explore the use of this metabolism to manipulate starch accumulation, Arabidopsis (Arabidopsis thaliana) plants were engineered by introducing RNAi constructs designed to reduce expression of AtGWD and AtSEX4. The timing of starch build-up was altered with ethanol-inducible and senescence-induced gene promoters. Ethanol induction of RNAi lines reduced transcript for AtGWD and AtSEX4 by 50%. The transgenic lines had seven times more starch than wild type at the end of the dark period but similar growth rates and total biomass. Elevated leaf starch content in maize leaves was engineered by making an RNAi construct against a gene in maize that appeared to be homologous to AtGWD. The RNAi construct was expressed using the constitutive ubiquitin promoter. Leaf starch content at the end of a night period in engineered maize plants was 20-fold higher than in untransformed plants with no impact on total plant biomass. We conclude that plants can be engineered to accumulate starch in the leaves with little impact on vegetative biomass. PMID:22321580

Weise, Sean E; Aung, Kimberly; Jarou, Zach J; Mehrshahi, Payam; Li, Ziru; Hardy, Anna C; Carr, David J; Sharkey, Thomas D

2012-06-01

90

Starch digestion capacity of poultry.  

PubMed

Starch is quantitatively the most important nutrient in poultry diets and will to a large extent be present as intact starch granules due to very limited extent of gelatinization during pelleting. Although native starch is difficult to digest due to a semi-crystalline structure, even fast-growing broiler chickens appears to be able to digest this starch more or less completely during passage through the jejunum. However, reduced starch digestibility has been observed, particularly in pelleted diets containing large quantities of wheat. Although properties of the starch granule such as size and components on the granule surface may affect digestibility, the entrapment of starch granules in cell walls and a protein matrix may be even more important factors impeding starch digestion. In that case, this and the fact that amylase secretion is normally very high in poultry may explain the lack of convincing effects of exogenous ?-amylase added to the diet. However, few well-designed experiments assessing mechanisms of starch digestion and the effect of ?-amylase supplementation have been carried out, and thus more research is needed in this important area. PMID:25012853

Svihus, B

2014-09-01

91

Thermoplastic starch composites and blends.  

E-print Network

??The central theme of this thesis was the development of thermoplastic starch materials and composites, their characterization and analysis of mechanical properties. X-ray diffraction methodology… (more)

Frost, K

2010-01-01

92

PLANT RESISTANCE Evaluation of Potato Tuber Moth (Lepidoptera: Gelechiidae)  

E-print Network

. The purpose of this study was to evaluate the ef�cacy of a Bt-cry5 transgene to control the potato tuber moth of Bt-cry5 Transgenic Potato Lines AHMED MOHAMMED,1 D. S. DOUCHES,2 W. PETT,3 E. GRAFIUS,3 J. COOMBS,2 in tuber tissues. Tuber bioassays using stored (11-12 mo old) and newly harvested tubers of Bt-cry5-Lemhi

Douches, David S.

93

Giant Tuberous Xanthomas in a Case of Type IIA Hypercholesterolemia  

PubMed Central

Tuberous xanthomas are papulonodular skin lesions present in lipoprotein metabolism disorders. A patient presented with multiple large swellings (up to 20 cm in size) all over the body, which on excision were found to be tuberous xanthomas. Investigations revealed the diagnosis of familial hypercholesterolemia. This case is reported to document the unusual presentation of giant tuberous xanthomas. PMID:23112520

Babu, Rajashekara; Venkataram, Aniketh; Santhosh, Shivashankar; Shivaswamy, Sadashivaiah

2012-01-01

94

Phases of Dormancy in Yam Tubers (Dioscorea rotundata)  

Microsoft Academic Search

Background and Aims The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which

E. I. ILE; P. Q. CRAUFURD; N. H. BATTEY; R. ASIEDU

2006-01-01

95

The three-dimensional distribution of minerals in potato tubers  

PubMed Central

Background and Aims The three-dimensional distributions of mineral elements in potato tubers provide insight into their mechanisms of transport and deposition. Many of these minerals are essential to a healthy human diet, and characterizing their distribution within the potato tuber will guide the effective utilization of this staple foodstuff. Methods The variation in mineral composition within the tuber was determined in three dimensions, after determining the orientation of the harvested tuber in the soil. The freeze-dried tuber samples were analysed for minerals using inductively coupled plasma-mass spectrometry (ICP-MS). Minerals measured included those of nutritional significance to the plant and to human consumers, such as iron, zinc, copper, calcium, magnesium, manganese, phosphorus, potassium and sulphur. Key Results The concentrations of most minerals were higher in the skin than in the flesh of tubers. The potato skin contained about 17 % of total tuber zinc, 34 % of calcium and 55 % of iron. On a fresh weight basis, most minerals were higher in tuber flesh at the stem end than the bud end of the tuber. Potassium, however, displayed a gradient in the opposite direction. The concentrations of phosphorus, copper and calcium decreased from the periphery towards the centre of the tuber. Conclusions The distribution of minerals varies greatly within the potato tuber. Low concentrations of some minerals relative to those in leaves may be due to their low mobility in phloem, whereas high concentrations in the skin may reflect direct uptake from the soil across the periderm. In tuber flesh, different minerals show distinct patterns of distribution in the tuber, several being consistent with phloem unloading in the tuber and limited onward movement. These findings have implications both for understanding directed transport of minerals in plants to stem-derived storage organs and for the dietary implications of different food preparation methods for potato tubers. PMID:21289026

Subramanian, Nithya K.; White, Philip J.; Broadley, Martin R.; Ramsay, Gavin

2011-01-01

96

Isolation and characterization of polysaccharides with the antitumor activity from Tuber fruiting bodies and fermentation system.  

PubMed

Fifty-two polysaccharides were isolated from the fermentation systems of Tuber melanosporum, Tuber indicum, Tuber sinense, Tuber aestivum and the fruiting bodies of Tuber indicum, Tuber himalayense, Tuber sinense by elution with an activated carbon column. Polysaccharides from Tuber fermentation system exhibited relatively higher in vitro antitumor activity against HepG2, A549, HCT-116, SK-BR-3, and HL-60 cells than those from Tuber fruiting bodies. All polysaccharides were mainly composed of D-mannose, D-glucose, and D-galactose, which suggested that the polysaccharides from Tuber fruiting bodies and fermentation system have identical chemical compositions. The results of antitumor activity and structural identification indicated that the polysaccharide fractions could promote antitumor activity. Tuber polysaccharides from Tuber fermentation system exhibited relatively higher than that from Tuber fruiting bodies. These results confirm the potential of Tuber fermentation mycelia for use as an alternative resource for its fruiting bodies. PMID:24272369

Zhao, Wei; Wang, Xiao-Hua; Li, Hong-Mei; Wang, Shi-Hua; Chen, Tao; Yuan, Zhan-Peng; Tang, Ya-Jie

2014-03-01

97

Developing Biodegradable Plastics from starch  

Microsoft Academic Search

The diversity and ubiquity of plastic products substantially testify to the versatility of the special class of engineering materials known as polymers. However, the non-biodegradability of these petrochemical-based materials has been a source of environmental concerns and hence, the driving force in the search for 'green' alternatives for which starch remains the frontliner. Starch is a natural biopolymer consisting predominantly

Olayide O. Fabunmi; Lope G. Tabil Jr; Satyanarayan Panigrahi; Peter R. Chang

98

Starch — Value Addition by Modification  

Microsoft Academic Search

Starch is one of the most important but flexible food ingredients possessing value added attributes for innumerable industrial applications. Its various chemically modified derivatives offer a great scope of high technological value in both food and non-food industries. Modified starches are designed to overcome one or more of the shortcomings, such as loss of viscosity and thickening power upon cooking

Rudrapatnam N. Tharanathan

2005-01-01

99

Damaged starch characterisation by ultracentrifugation  

Microsoft Academic Search

The relative molecular size distributions of a selection of starches (waxy maize, pea and maize) that had received differing amounts of damage from ball milling (as quantified by susceptibility to ?-amylase) were compared using analytical ultracentrifugation. Starch samples were solubilised in 90% dimethyl sulfoxide, and relative size distributions were determined in terms of the apparent distribution of sedimentation coefficients g?(s)

Richard F. Tester; Trushar Patel; Stephen E. Harding

2006-01-01

100

Microbial starch-binding domain.  

PubMed

Glucosidic bonds from different non-soluble polysaccharides such as starch, cellulose and xylan are hydrolyzed by amylases, cellulases and xylanases, respectively. These enzymes are produced by microorganisms. They have a modular structure that is composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. Starch-binding modules are present in microbial enzymes that are involved in starch metabolism; these are classified into several different families on the basis of their amino acid sequence similarities. Such binding domains promote attachment to the substrate and increase its concentration at the active site of the enzyme, which allows microorganisms to degrade non-soluble starch. Fold similarities are better conserved than sequences; nevertheless, it is possible to notice two evolutionary clusters of microbial starch-binding domains. These domains have enormous potential as tags for protein immobilization, as well as for the tailoring of enzymes that play a part in polysaccharide metabolism. PMID:15939348

Rodríguez-Sanoja, Romina; Oviedo, Norma; Sánchez, Sergio

2005-06-01

101

Ezrin and moesin expression within the developing human cerebrum and tuberous sclerosis-associated cortical tubers  

Microsoft Academic Search

The ERM (ezrin, radixin, and moesin) proteins belong to the band-4.1 superfamily of membrane-cytoskeleton-linking proteins which bind to the actin cytoskeleton via their C-terminal sequences and bind ERM binding membrane proteins (ERMBMPs). We investigated the immunohistochemical expression of two of the ERM proteins (ezrin and moesin) in developing human cerebral cortex and in cortical tubers from patients with tuberous sclerosis

Michael W. Johnson; Hajime Miyata; Harry V. Vinters

2002-01-01

102

Cell-Specific Alterations of Glutamate Receptor Expression in Tuberous Sclerosis Complex Cortical Tubers  

PubMed Central

Objective Genetic loss of TSC1/TSC2 function in tuberous sclerosis complex (TSC) results in overactivation of the mammalian target of rapamycin complex 1 pathway, leading to cellular dysplasia. We hypothesized that the dysplastic cells in TSC tubers are heterogeneous, including separable classes on a neuronal-glial spectrum, and that these dysplastic cells express glutamate receptor (GluR) patterns consistent with increased cortical network excitability. Methods Surgically resected human cortical tubers and nondysplastic epileptic cortical samples were analyzed by double-label immunocytochemistry for coexpression of neuronal and glial markers, the TSC1/TSC2 pathway downstream molecule phospho-S6 (pS6) and GluR subunits, and compared with control cortical tissue. Western blotting was used to quantify changes in GluR subunit expression in tubers versus controls. Results We demonstrate that cortical tubers contain a broad spectrum of cell types including disoriented pyramidal cells, dysplastic neurons, giant neuroglial cells, dysplastic astroglia, and reactive astrocytes. Dysplastic neurons, giant cells, and dysplastic astroglia express high levels of pS6 and demonstrate altered GluR subunit composition, resembling those of normal immature neurons and glia. In contrast, nondysplastic neurons in TSC and non-TSC epileptic lesions express lower pS6 levels and display changes in GluR subunit expression that are distinct from the patterns seen in tuber dysplastic cells. Interpretation This work significantly expands the spectrum of abnormal cells recognized in tubers beyond the classic tuber giant cell and demonstrates cell-specific abnormalities in GluR expression that may contribute to seizure pathogenesis in TSC. Furthermore, these results suggest that subunit-specific antagonists may be of potential use in the treatment of epilepsy in TSC. PMID:18350576

Talos, Delia M.; Kwiatkowski, David J.; Cordero, Kathia; Black, Peter M.; Jensen, Frances E.

2009-01-01

103

Symptomatic osteolipoma of the tuber cinereum.  

PubMed

Intracranial osteolipomas are rare lesions which occur in the region of the tuber cinereum. All cases reported to date have been incidental autopsy findings. We describe a patient who presented with a variety of neurological symptoms and had a typical osteolipoma surgically removed. PMID:8998859

Mackenzie, I R; Girvin, J P; Lee, D

1996-01-01

104

Structure and morphology of baked starch foams  

Microsoft Academic Search

Baked starch foams were characterized by several physical methods in order to better understand the relationship between process parameters and starch foam structure. In this process, a thin-walled object such as a plate is formed by heating a starch batter inside a closed mould. Normal corn and potato starches are gelatinized by this treatment but some swollen granules remain. The

R. L Shogren; J. W Lawton; W. M Doane; K. F Tiefenbacher

1998-01-01

105

Hydroxyeyhyl starch: Controversies revisited  

PubMed Central

Hydroxyethyl starch (HES) family has been one of the cornerstones in fluid management for over four decades. Recent evidence from clinical studies and meta-analyses has raised few concerns about the safety of these fluids, especially in certain subpopulations of patients. High-quality clinical trials and meta-analyses have emphasized nephrotoxic effects, increased risk of bleeding, and a trend toward higher mortality in these patients after the use of HES solutions. Scientific evidence was derived from international guidelines, aggregated research literature, and opinion-based evidence was obtained from surveys and other activities (e.g., internet postings). On critical analysis of the current data available, it can be summarized that further large scale trials are still indicated before HES can be discarded. PMID:25425769

Datta, Rashmi; Nair, Rajeev; Pandey, Anil; Kumar, Nitish; Sahoo, Tapan

2014-01-01

106

Powder and compaction characteristics of pregelatinized starches.  

PubMed

Pregelatinized starch is widely used as a pharmaceutical aid, especially as a filler-binder. It is known that the tableting performance of excipients could be affected by their source. The aim of this study was to evaluate the powder and tableting properties of pregelatinized starches obtained from yucca, corn and rice and compare those properties with those of Starch 1500. This material had the lowest particle size, and porosity and largest density and best flow. However, yucca starch and corn starch showed an irregular granule morphology, better compactibility and compressibility than Starch 1500. Their onset of plastic deformation and their strain rate sensitivity was comparable to that of Starch 1500. These two materials showed compact disintegration slower that Starch 1500. Conversely, rice starch showed a high elasticity, and friability, low compactibility, which are undesirable for direct compression. This study demonstrated the potential use of pregelatinized starches, especially those obtained from yucca and corn as direct compression filler-binders. PMID:22822539

Rojas, J; Uribe, Y; Zuluaga, A

2012-06-01

107

Sorghum tannins: Interaction with Starch and its Effects on in vitro Starch Digestibility  

E-print Network

compounds with starch molecules and their effect on in vitro starch digestibility. High tannin (predominant in large molecular weight PA, 80%), black (monomeric polyphenols) and white (low in polyphenols) sorghum phenolic extracts were cooked with starches...

Ribeiro de Barros, Frederico

2012-12-10

108

Identification of Armillaria nabsnona in gastrodia tubers.  

PubMed

The symbiosis between Armillaria species and an achlorophylous orchid Gastrodia elata BLUME has been reported. The main species described as a symbiont is Armillaria mellea (VAHL: FR.) KUMMER, known widely as a primary root rot pathogen. Samples collected from the rhizomorphs attached to the tuber of G. elata were separated and analyzed. Molecular analysis based on sequencing of the intergenic spacer 1 (IGS-1) and internal transcribed spacer (ITS) regions of the ribosomal DNA (rDNA) was performed, coupled with restriction fragment length polymorphism (RFLP) of the IGS-1 region. Cultural morphology and features of basidiomata were also used to characterize the isolates. Phylogenetic analysis and morphological data strongly suggested that the fungus present in the tubers of G. elata is Armillaria nabsnona. This is the first report of occurrence of this Armillaria species in association with G. elata. PMID:18591784

Sekizaki, Haruo; Kuninaga, Shiro; Yamamoto, Mizuho; Asazu, Sandra Naomi; Sawa, Satoko; Kojoma, Mareshige; Yokosawa, Ryozo; Yoshida, Naotoshi

2008-07-01

109

Antiretrogradation in cooked starch-based product application of tea polyphenols.  

PubMed

Retrogradation in cooked starch-based products is a significant hindrance in extending the shelf life of these products as they become progressively hard to bite over short time periods (say 1 or 2 months). In this study, the effects of tea polyphenols (TPs) on cooked amylopectin-rich cassava starch have been investigated. Cassava starch was mixed with TPs and then gelatinized to form starch gels. The obtained gels were stored for up to 80 d and characterized by X-ray diffraction (XRD), hardness test, color analysis, and Fourier transform infrared spectroscopy (FT-IR). The results of XRD show that the formation of long-range ordered structure of amylopectin was retarded by the interaction of TPs with amylopectin via hydrogen bond. The results of hardness test show that the accelerating increase in the hardness of cassava starch gel was retarded by the addition of TPs. The increase in hardness versus time can be correlated well using a single-parameter exponential equation. The increase in hardness, variations in color, and FT-IR spectrum of the TPs treated samples during storage with TPs were relatively small, suggesting that the retrogradation of starch is inhibited by TPs. This work presents an opportunity of antiretrogradation in the related products. PMID:25155643

Wu, Lijing; Che, Liming; Chen, Xiao Dong

2014-10-01

110

TUBEROUS SCLEROSIS COMPLEX: FROM GENES TO BEHAVIOURAL AND COGNITIVE PHENOTYPES  

Microsoft Academic Search

Tuberous sclerosis complex (TSC) is a disorder of cell migration, proliferation, and differentiation, resulting from mutations in TSC1, the gene on chromosome 9q34, and in TSC2, the gene on chromosome l6pl3. Cortical tubers constitute the hallmark of the disease and are pathognomonic of cerebral TSC. The number and the localisation of cortical tubers may account for the variability in the

Paolo Curatolo; Roberta Bombardieri; Caterina Cerminara; Cinzia Galasso

111

Functional genomic analysis of potato tuber life-cycle  

Microsoft Academic Search

Summary  Potato tuber life-cycle is composed of many individual developmental stages including tuber formation, tuber development,\\u000a dormancy and sprouting. We have used cDNA-AFLP fingerprinting to analyse gene expression in 24 individual stages of development,\\u000a over the period from stolon formation through sprouting. In addition to these developmental stages, different tissues were\\u000a analysed to assess tissue specificity and various controls were incorporated

Christian Bachem; Rutger van der Hoeven; Joost Lucker; Ronald Oomen; Emanuela Casarini; Evert Jacobsen; Richard Visser

2000-01-01

112

Accumulation of PrLeg, a Perilla legumin protein in potato tuber results in enhanced level of sulphur-containing amino acids.  

PubMed

Potato is the fourth staple food in the world, following rice, wheat, and maize, whereas tubers contain high quality of starch, relatively high amounts of vitamin C and many other important substances. It also contains relatively good quality of protein (about 3 to 6% of the dried weight) and patatin, and 11S globulin is a major storage protein with high level of lysine. However, tuber protein contains relatively low amounts of sulphur-containing amino acids, which may result in low nutritional value. Recently, we cloned a gene encoding PrLeg polypeptide, a seed storage protein from Perilla, which contains relatively higher levels of sulphur-containing amino acids. We transformed PrLeg cDNA into a potato plant to over-express under the direction of the tuber-specific promoter, patatin. Most of the transgenic lines identified through PCR and RT-PCR analyses were able to accumulate high amount of prLeg transcript in their tuber tissue, while very little or no transcript that were detected in their leaf tissues. The level of methionine content was elevated up to three-fold compared to non-transgenic parental line, without any significant changes in other amino acids, suggesting that further research is required to get a deeper insight into their nutritional value. PMID:24161240

Goo, Young-Min; Kim, Tae-Won; Lee, Min-Kyung; Lee, Shin-Woo

2013-09-01

113

Tuberous sclerosis complex without tubers and subependymal nodules: a phenotype-genotype study.  

PubMed

Tuberous sclerosis complex (TSC) is caused by a mutation in the TSC1 or TSC2 genes. However, 15% of patients have no mutation identified. Tubers and subependymal nodules (SENs) are the typical brain lesions in TSC and are present in 90-95% of patients. The objective of this study is to characterize the specific genotype-phenotype of patients without these lesions. We analyzed the features of 11 patients without typical TSC neuroanatomic features. Ten had TSC1/TSC2 mutational analysis, which was negative. Clinically they had lesions thought to be of neural crest (NC) origin, such as hypomelanotic macules, facial angiofibromas, cardiac rhabdomyomas, angiomyolipomas, and lymphangioleiomyomatosis. We hypothesize that patients without tubers and SENs reflect mosaicism caused by a mutation in TSC1 or TSC2 in a NC cell during embryonic development. This may explain the negative results in TSC1 and TSC2 testing in DNA from peripheral leukocytes. PMID:23909698

Boronat, S; Shaaya, E A; Doherty, C M; Caruso, P; Thiele, E A

2014-08-01

114

Genotypic and environmental factors influencing flesh color, carotene content, total carotenoids, total phenolics and antioxidant activity in potato (Solanum tuberosum L.)  

E-print Network

The influence of variety and location on flesh color, pigment content and total carotenoid content was studied using Texas and Colorado grown tubers from ten yellow flesh and two white flesh potato varieties. Antioxidant activity and total phenolics...

Al-Saikhan, Mohamed Salem

2012-06-07

115

Color Thieves  

NSDL National Science Digital Library

This story poses a challenge to its readers to solve the mystery of light, color, and how we see color. It also asks the question, "What is color?" After investigating the phenomena of color and color filters, students should realize that light is made up

Konicek-Moran, Richard

2009-04-01

116

Slowly Digestible Starch: Concept, Mechanism, and Proposed Extended Glycemic Index  

Microsoft Academic Search

Starch is the major glycemic carbohydrate in foods, and its nutritional property is related to its rate and extent of digestion and absorption in the small intestine. A classification of starch into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) based on the in vitro Englyst test is used to specify the nutritional quality of starch.

Genyi Zhang; Bruce R. Hamaker

2009-01-01

117

Characterization of Nubet and Franubet barley starches  

Microsoft Academic Search

Franubet, a mutant of Nubet, had grains of smaller weight, less starch, but greater protein content than did Nubet. Nubet starch had simple granules with bimodal granule size distribution (diameters of 9–22 and 1.2–4 ?m for the A and B granules, respectively), whereas Franubet starch had smaller (diameters of 1–4 ?m) and irregular-shaped granules, and some displayed compound starch granules.

Dong Soon Suh; Tamara Verhoeven; Kay Denyer; Jay-lin Jane

2004-01-01

118

Physical properties of cryomilled rice starch  

Microsoft Academic Search

Cryomilling of rice starch was evaluated as a non-chemical way to modify starch structure and properties. Cryomilling in a liquid nitrogen bath (63–77.2K) was done to Quest (10.80% amylose) and Pelde (20.75% amylose) rice starch at five different time frames (0, 15, 30, 45, and 60min). The viscosity of the cryomilled rice starch decreased significantly (p<0.05) with increasing milling duration,

A. F. Devi; K. Fibrianto; P. J. Torley; B. Bhandari

2009-01-01

119

Starch Formation in the Cereal Endosperm  

Microsoft Academic Search

Starch comprises ?70% of the dry weight of a cereal seed. Because the vast majority of\\u000a this starch is in the cereal endosperm and cereals are the major agricultural plants grown world-wide, endosperm\\u000a starch is the largest single contributor to the world's calorie supply. Starch biosynthesis in the endosperm\\u000a is described herein. Emphasis is placed on classical “biochemical genetics”, with the

L. Curtis Hannah

120

Diffusion tensor imaging in children and adolescents with tuberous sclerosis  

Microsoft Academic Search

Background: Tuberous sclerosis (TS) is characterised by benign hamartomatous lesions in many organs. Diffusion tensor imaging (DTI) can detect microstructural changes in pathological processes. Objective: To determine apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps in children with TS and to investigate the diffusion properties in cortical tubers, white-matter lesions, perilesional white matter, and contralateral normal-appearing white matter, and

Demet Karadag; Hans-J. Mentzel; Daniel Güllmar; Tina Rating; Ulrike Löbel; Ulrich Brandl; Jürgen R. Reichenbach; Werner A. Kaiser

2005-01-01

121

Psychiatric symptoms in an individual with tuberous sclerosis  

PubMed Central

Abstract Tuberous sclerosis is a rare disorder with no specific treatment. In some cases psychological symptoms are the initial presenting symptoms, making the differential diagnosis difficult. We describe a patient with tuberous sclerosis who developed psychiatric symptoms and discuss the use of low-dose quetiapine to control her emotional and behavioral symptoms.

Liu, Qiaojin; Gao, Jinli

2012-01-01

122

Neuroepileptic Correlates of Autistic Symptomatology in Tuberous Sclerosis  

ERIC Educational Resources Information Center

Tuberous sclerosis is a genetic condition that is strongly associated with the development of an autism spectrum disorder. However, there is marked variability in expression, and only a subset of children with tuberous sclerosis develop autism spectrum disorder. Clarification of the mechanisms that underlie the association and variability in…

Bolton, Patrick F.

2004-01-01

123

Color realism and color science  

E-print Network

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, ...

Byrne, Alex

124

Modeling of Lactose Crystallization and Color Changes in Model Infant Foods  

Microsoft Academic Search

Lactose crystallization and color changes in formu- las containing ?-lactoglobulin and gelatinized starch were investigated. Model infant formulas were pre- pared by colyophilization of 3 components (lactose, ?- lactoglobulin, and gelatinized starch). A mixture de- sign was used to choosethe percentage of each mixture component. These formulas were stored for 3 mo at different relative humidities (RH), ranging from ap-

A. Nasirpour; J. Scher; M. Linder; S. Desobry

2006-01-01

125

Colored lattices  

PubMed Central

Combinations of translations and color permutations are derived that leave a periodic array of colored points—a colored lattice—apparently unchanged. It is found that there are three types of colored lattices: (1) those in which all rows and nets have more than one color, (2) those in which there are rows with only one color, and (3) those in which there are both rows and nets with only one color. The color permutation groups of colored lattices are all Abelian. The direct product of three independent cyclic subgroups is required by type 1, but only two are required by type 2; in type 3 the color permutation group consists of the n powers of a cyclic permutation of all n colors present—i.e., the group consists of a single cycle. PMID:16592585

Harker, David

1978-01-01

126

The diurnal metabolism of leaf starch  

Microsoft Academic Search

Starch is a primary product of photosynthesis in leaves. In most plants, a large fraction of the carbon assimilated during the day is stored transiently in the chloroplast as starch for use during the subsequent night. Photosynthetic partitioning into starch is finely regulated, and the amount of carbohydrate stored is dependent on the environmental conditions, particularly day length. This regulation

2007-01-01

127

Cationic starches as gas hydrate kinetic inhibitors  

Microsoft Academic Search

This work investigated the kinetic inhibiting effect of a number of cationic starches in hydrate formation experiments with methane and methane\\/ethane and methane\\/propane gas mixtures. The starches were found to exhibit a very weak inhibiting effect except for tapioca starch which increased the induction time (delay of onset of crystallization) by an order of magnitude. The addition of polyethylene oxide

Ju Dong Lee; Huijie Wu; Peter Englezos

2007-01-01

128

Alterations in Cytosolic Glucose-Phosphate Metabolism Affect Structural Features and Biochemical Properties of Starch-Related Heteroglycans1[W  

PubMed Central

The cytosolic pools of glucose-1-phosphate (Glc-1-P) and glucose-6-phosphate are essential intermediates in several biosynthetic paths, including the formation of sucrose and cell wall constituents, and they are also linked to the cytosolic starch-related heteroglycans. In this work, structural features and biochemical properties of starch-related heteroglycans were analyzed as affected by the cytosolic glucose monophosphate metabolism using both source and sink organs from wild-type and various transgenic potato (Solanum tuberosum) plants. In leaves, increased levels of the cytosolic phosphoglucomutase (cPGM) did affect the cytosolic heteroglycans, as both the glucosyl content and the size distribution were diminished. By contrast, underexpression of cPGM resulted in an unchanged size distribution and an unaltered or even increased glucosyl content of the heteroglycans. Heteroglycans prepared from potato tubers were found to be similar to those from leaves but were not significantly affected by the level of cPGM activity. However, external glucose or Glc-1-P exerted entirely different effects on the cytosolic heteroglycans when added to tuber discs. Glucose was directed mainly toward starch and cell wall material, but incorporation into the constituents of the cytosolic heteroglycans was very low and roughly reflected the relative monomeric abundance. By contrast, Glc-1-P was selectively taken up by the tuber discs and resulted in a fast increase in the glucosyl content of the heteroglycans that quantitatively reflected the level of the cytosolic phosphorylase activity. Based on 14C labeling experiments, we propose that in the cytosol, glucose and Glc-1-P are metabolized by largely separated paths. PMID:18805950

Fettke, Joerg; Nunes-Nesi, Adriano; Alpers, Jessica; Szkop, Michal; Fernie, Alisdair R.; Steup, Martin

2008-01-01

129

Colorful Chemistry.  

ERIC Educational Resources Information Center

Described is an color-making activity where students use food coloring, eyedroppers, and water to make various colored solutions. Included are the needed materials and procedures. Students are asked to write up the formulas for making their favorite color. (KR)

Williams, Suzanne

1991-01-01

130

Effect of farming systems on the yield, quality parameters and sensory properties of conventionally and organically grown potato (Solanum tuberosum L.) tubers.  

PubMed

The objectives of this two-year research were to study the impact of two different farming types, conventional and organic, on the yield and sensory properties of five Lithuanian varieties of potato tuber. The parameters and properties examined were: phenolic acids; dry matter and starch content; and the spread and intensity of Phytophthora infestans growth. It was determined that potato yield fluctuates with the variety, but for conventional farming it is significantly (p<0.05) higher than that obtained by organic farming. The farming type has no significant effect (p>0.05) on the content of phenolic acids. No significant effect (p>0.05) of farming type on dry matter and starch content, or sensory properties was found. No significant relation (p>0.05) was found between the content of phenolic acids and P. infestans spread. The spread of P. infestans was faster and infection was heavier in organically grown potatoes. PMID:24128562

Brazinskiene, V; Asakaviciute, R; Miezeliene, A; Alencikiene, G; Ivanauskas, L; Jakstas, V; Viskelis, P; Razukas, A

2014-02-15

131

Color Mixing  

NSDL National Science Digital Library

This is an online activity where learners can virtually mix different colors of light or paint (you can switch between them) and see how the colors combine. It demonstrates how millions of colors are created on computer monitors and TVs, and in art and printing. Learners can try to match a given target color ("Mix to Match"), or simply play around with mixtures ("Mix for Fun"). Background information explains how light is additive (more colors tends towards white), whereas paint absorbs color and is subtractive (more colors tends towards black). There's also information about how the human eye works.

Industry, Oregon M.

2002-01-01

132

Solvent effects on starch dissolution and gelatinization.  

PubMed

The disruption of starch granular structure during dissolution in varying concentrations of N-methyl morpholine N-oxide (NMMO) has been studied using three maize starches with varying ratios of amylose and amylopectin. Behavior in NMMO has been characterized by differential scanning calorimetry (DSC), microscopy, rapid viscosity analysis (RVA), and rheometry. Exothermic transitions were observed for the three starches in both 78 and 70% NMMO; the transition changed to an endotherm at 60 and 50% NMMO. Consistent with DSC, hot stage microscopy showed that starch granules dissolved at NMMO concentrations of 78 and 70%, whereas in 60 and 50% NMMO, gelatinization behavior similar to that found for starch in water was observed. Mechanical spectroscopy revealed the dominant viscous behavior (G? > G') of starch at NMMO concentrations of 70 and 78% and more elastic behavior (G' > G?) at lower concentrations. Starch solutions in 78% NMMO obey the Cox-Merz rule, suggesting that the solutions are homogeneous on a molecular level. PMID:21696171

Koganti, Nagamani; Mitchell, John R; Ibbett, Roger N; Foster, Tim J

2011-08-01

133

Physicochemical properties of starches and proteins in alkali-treated mungbean and cassava starch granules.  

PubMed

This study explored the influences of envelope integrity of cooked starch granules on physicochemical and thermophysical properties of mungbean and cassava starches. Alkali treatment was used to selectively leach amylose from the amorphous region of both starches and partially fragmented starch molecules into lower-molecular-weight polymers. It was found that despite the loss of 40% of the original content of amylose, both mungbean and cassava starches retained similar crystallinities, gelatinization temperature ranges, and pasting profiles compared to the native starches. However, the loss of granule-bound starch synthases during alkali treatment and subsequent alkali cooking in excess water played significant roles in determining granular disintegration. The alterations in envelope integrity due to the negative charge repulsion among polymers within the envelope of swollen granules, and the fragmentation of starch molecules, were responsible for the alterations in thermophysical properties of mungbean and cassava starches cooked under alkaline conditions. PMID:24708949

Israkarn, Kamolwan; Na Nakornpanom, Nantarat; Hongsprabhas, Parichat

2014-05-25

134

Changes in potato phenylpropanoid metabolism during tuber development.  

PubMed

Phenylpropanoid metabolite and transcript expression during different developmental stages were examined in field grown potatoes. Carbohydrate and shikimic acid metabolism was assessed to determine how tuber primary metabolism influences phenylpropanoid metabolism. Phenylpropanoid concentrations were highest in immature tubers, as were some transcript levels and enzyme activities including phenylalanine ammonia lyase (PAL). Phenylpropanoid concentration differences between mature and immature tubers varied by genotype, but in some cases were approximately three-fold. The most abundant phenylpropanoid was chlorogenic acid (5CGA), which decreased during tuber maturation. Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) transcripts were highly expressed relative to other phenylpropanoid genes, but were not well correlated with 5CGA concentrations (r = -0.16), whereas HQT enzyme activity was. In contrast to 5CGA, less abundant chlorogenic isomers increased during development. Concentrations of hydroxycinnamic acid amides were higher in immature tubers, as was expression of arginine- and ornithine decarboxylases. Expression of several genes involved in carbohydrate or shikimate metabolism, including sucrose synthase and DAHP, showed similar developmental patterns to phenylpropanoid pools, as did shikimate dehydrogenase enzyme activity. Sucrose, glucose and fructose concentrations were highest in immature tubers. Exogenous treatment of potatoes with sugars stimulated phenylpropanoid biosynthesis, suggesting sugars contribute to the higher phenylpropanoid concentrations in immature tubers. These changes in phenylpropanoid expression suggest the nutritional value of potatoes varies during development. PMID:23434926

Navarre, Duroy A; Payyavula, Raja S; Shakya, Roshani; Knowles, N Richard; Pillai, Syamkumar S

2013-04-01

135

Inheritance of tuber traits from phureja in diploid phureja - Tuberosum hybrids  

Microsoft Academic Search

Heterosis and combining ability for tuber number, average tuber weight, and total yield were evaluated in Phureja - haploid\\u000a Tuberosum diploid hybrids. Heterosis estimates suggest dominance for high tuber number and low average tuber weight in Phureja.\\u000a Total yield of the hybrid population exceeded the high parent. The higher-yielding segment of hybrids had a significantly\\u000a higher number of smaller tubers

N. A. McHale; F. I. Lauer

1981-01-01

136

Starch-Based Plastic Foams From Various Starch Sources1  

Microsoft Academic Search

Cereal Chem. 73(5):601-604 Corn, tapioca, wheat, rice, and potato starches were extruded with grafted as was confirmed by X-ray diffraction patterns of extrudates and 30% polystyrene and 5% magnesium silicate or 1% polycarbonate or water solubility indexes. The expansion, unit density and water solubility 0.5% azodicarbonamide in a single screw C. W. Brabender laboratory index of the extrudates depended on

S. BHATNAGAR; MILFORD A. HANNA

137

Improved resolution of major clades within Tuber and taxonomy of species within the Tuber gibbosum complex.  

PubMed

Tuber gibbosum Harkn., described from northern California, originally was thought to be a single, variable species that fruited from autumn through winter to spring. It has become popular as a culinary truffle in northwestern USA, where it is commercially harvested. Morphological studies suggested it might be a complex that includes at least two species. We conducted morphological and phylogenetic studies of the complex to determine how many species it might contain and how they differed morphologically, geographically and seasonally. We also provide the first LSU phylogeny for the genus Tuber. Phylogenetic analyses resolve nine major clades in the genus with high bootstrap support and distinguish the Gibbosum clade from the Aestivum, Excavatum, Macrosporum, Magnatum, Melanosporum, Puberulum, Rufum and Spinoreticulatum clades. Further analyses of ITS and LSU regions revealed four distinct species in the Gibbosum complex. Although morphologically similar the four species differ in spore size and shape and in peridial anatomy. These species share the synapomorphy of having suprapellis hyphae with distinctive, irregular wall swellings at maturity; we have not seen this hyphal type in any other Tuber spp. worldwide. The three new species are named and described as T. bellisporum Bonito & Trappe, T. castellanoi Bonito & Trappe and T. oregonense Trappe, Bonito & Rawlinson. PMID:20943504

Bonito, Gregory; Trappe, James M; Rawlinson, Pat; Vilgalys, Rytas

2010-01-01

138

Physical association of starch biosynthetic enzymes with starch granules of maize endosperm. Granule-associated forms of starch synthase I and starch branching enzyme II.  

PubMed Central

Antibodies were used to probe the degree of association of starch biosynthetic enzymes with starch granules isolated from maize (Zea mays) endosperm. Graded washings of the starch granule, followed by release of polypeptides by gelatinization in 2% sodium dodecyl sulfate, enables distinction between strongly and loosely adherent proteins. Mild aqueous washing of granules resulted in near-complete solubilization of ADP-glucose pyrophosphorylase, indicating that little, if any, ADP-glucose pyrophosphorylase is granule associated. In contrast, all of the waxy protein plus significant levels of starch synthase I and starch branching enzyme II (BEII) remained granule associated. Stringent washings using protease and detergent demonstrated that the waxy protein, more than 85% total endosperm starch synthase I protein, and more than 45% of BEII protein were strongly associated with starch granules. Rates of polypeptide accumulation within starch granules remained constant during endosperm development. Soluble and granule-derived forms of BEII yielded identical peptide maps and overlapping tryptic fragments closely aligned with deduced amino acid sequences from BEII cDNA clones. These observations provide direct evidence that BEII exits as both soluble and granule-associated entities. We conclude that each of the known starch biosynthetic enzymes in maize endosperm exhibits a differential propensity to associate with, or to become irreversibly entrapped within, the starch granule. PMID:8754683

Mu-Forster, C; Huang, R; Powers, J R; Harriman, R W; Knight, M; Singletary, G W; Keeling, P L; Wasserman, B P

1996-01-01

139

Thermal and rheological properties of breadfruit starch.  

PubMed

The thermal and rheological properties of breadfruit starch were studied using DSC and 2 different rheometers. It was found that the gelatinization temperature of starch with excess moisture content (>70%) was at approximately 75 °C. A new endotherm was detected at about 173 °C when the moisture content was lower than required for full gelatinization of the starch. A detailed examination revealed that this endotherm represented the melting of amylose-lipid complexes. Breadfruit starch paste exhibited shear-thinning fluid characteristics, and good thermal and pH stability. The setback viscosity of the breadfruit starch was lower than that of potato and corn starches. The rheological properties of the breadfruit starch paste was well described by the Herschel-Bulkley model at a shear rate of 0 to 100 s(-1), where R(2) is greater than 0.95, and it behaved like a yield-pseudoplastic fluid. Both the storage modulus and loss modulus of the paste initially increased sharply, then dropped after reaching the gelatinization peak. Breadfruit starch gel showed both flexibility and viscosity. Suspension with 6% starch content exhibited very weak gel rigidity; however, this increased significantly at starch contents above 20%. PMID:21535676

Wang, Xueyu; Chen, Ling; Li, Xiaoxi; Xie, Fengwei; Liu, Hongshen; Yu, Long

2011-01-01

140

Color realism and color science.  

PubMed

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in the mind." The article has two other purposes: First, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. The first part explains the problem of color realism and makes some useful distinctions. These distinctions are then used to expose various confusions that often prevent people from seeing that the issues are genuine and difficult, and that the problem of color realism ought to be of interest to anyone working in the field of color science. The second part explains the various leading answers to the problem of color realism, and (briefly) argues that all views other than our own have serious difficulties or are unmotivated. The third part explains and motivates our own view, that colors are types of reflectances and defends it against objections made in the recent literature that are often taken as fatal. PMID:14598439

Byrne, Alex; Hilbert, David R

2003-02-01

141

The simultaneous abolition of three starch hydrolases blocks transient starch breakdown in Arabidopsis.  

PubMed

In this study, we investigated which enzymes are involved in debranching amylopectin during transient starch degradation. Previous studies identified two debranching enzymes, isoamylase 3 (ISA3) and limit dextrinase (LDA), involved in this process. However, plants lacking both enzymes still degrade substantial amounts of starch. Thus, other enzymes/mechanisms must contribute to starch breakdown. We show that the chloroplastic ?-amylase 3 (AMY3) also participates in starch degradation and provide evidence that all three enzymes can act directly at the starch granule surface. The isa3 mutant has a starch excess phenotype, reflecting impaired starch breakdown. In contrast, removal of AMY3, LDA, or both enzymes together has no impact on starch degradation. However, removal of AMY3 or LDA in addition to ISA3 enhances the starch excess phenotype. In plants lacking all three enzymes, starch breakdown is effectively blocked, and starch accumulates to the highest levels observed so far. This provides indirect evidence that the heteromultimeric debranching enzyme ISA1-ISA2 is not involved in starch breakdown. However, we illustrate that ISA1-ISA2 can hydrolyze small soluble branched glucans that accumulate when ISA3 and LDA are missing, albeit at a slow rate. Starch accumulation in the mutants correlates inversely with plant growth. PMID:23019330

Streb, Sebastian; Eicke, Simona; Zeeman, Samuel C

2012-12-01

142

The Simultaneous Abolition of Three Starch Hydrolases Blocks Transient Starch Breakdown in Arabidopsis*  

PubMed Central

In this study, we investigated which enzymes are involved in debranching amylopectin during transient starch degradation. Previous studies identified two debranching enzymes, isoamylase 3 (ISA3) and limit dextrinase (LDA), involved in this process. However, plants lacking both enzymes still degrade substantial amounts of starch. Thus, other enzymes/mechanisms must contribute to starch breakdown. We show that the chloroplastic ?-amylase 3 (AMY3) also participates in starch degradation and provide evidence that all three enzymes can act directly at the starch granule surface. The isa3 mutant has a starch excess phenotype, reflecting impaired starch breakdown. In contrast, removal of AMY3, LDA, or both enzymes together has no impact on starch degradation. However, removal of AMY3 or LDA in addition to ISA3 enhances the starch excess phenotype. In plants lacking all three enzymes, starch breakdown is effectively blocked, and starch accumulates to the highest levels observed so far. This provides indirect evidence that the heteromultimeric debranching enzyme ISA1-ISA2 is not involved in starch breakdown. However, we illustrate that ISA1-ISA2 can hydrolyze small soluble branched glucans that accumulate when ISA3 and LDA are missing, albeit at a slow rate. Starch accumulation in the mutants correlates inversely with plant growth. PMID:23019330

Streb, Sebastian; Eicke, Simona; Zeeman, Samuel C.

2012-01-01

143

Molecular disassembly of starch granules during gelatinization and its effect on starch digestibility: a review.  

PubMed

Starch is the most important glycemic carbohydrate in foods. The relationship between the rate and extent of starch digestion to produce glucose for absorption into the bloodstream and risk factors for diet-related diseases is of considerable nutritional interest. Native starch is attacked slowly by enzymes, but after hydrothermal processing its susceptibility to enzymatic breakdown is greatly increased. Most starch consumed by humans has undergone some form of processing or cooking, which causes native starch granules to gelatinize, followed by retrogradation on cooling. The extent of gelatinization and retrogradation are major determinants of the susceptibility of starch to enzymatic digestion and its functional properties for food processing. The type and extent of changes that occur in starch as a result of gelatinization, pasting and retrogradation are determined by the type of the starch, processing and storage conditions. A mechanistic understanding of the molecular disassembly of starch granules during gelatinization is critical to explaining the effects of processing or cooking on starch digestibility. This review focuses on the molecular disassembly of starch granules during starch gelatinization over a wide range of water levels, and its consequential effect on in vitro starch digestibility and in vivo glycemic index. PMID:24096569

Wang, Shujun; Copeland, Les

2013-11-01

144

Color notations  

E-print Network

This study presents research regarding the language of colors and of computers. The focus was color: translated through personal imagery, transferred and changed through media, and programmed through the computer. The ...

Gardner, Nancy

1981-01-01

145

Bubble Colors  

NSDL National Science Digital Library

This Exploratorium site provides an explanation of how soap films produce color bands. Wave interference is used to explain the colors observed without mathematics. Photos illustrate the phenomenon and drawings help make the explanation clear.

2008-06-19

146

Detection of Tuber melanosporum DNA in soil.  

PubMed

Our objectives were (i) to develop a molecular method to detect mycelia of Tuber melanosporum (black truffle) in soil and (ii) to test for mycelial distribution around two truffle-bearing Quercus ilex trees in a truffle orchard. Isolation of total DNA from soil was performed, followed by PCR amplification with T. melanosporum-specific primers and restriction analysis. To address the detection sensitivity level, soil samples were inoculated with known amounts of gleba of T. melanosporum. The detection limit was >/=11.4 mug of hyphae g(-1) of soil. Mycelium was detected primarily within the area defined by the truffle burn and within the top 35 cm of the soil in all directions from the trees. PMID:16445753

Suz, Laura M; Martín, María P; Colinas, Carlos

2006-01-01

147

Dialdehyde starch and zein plastic: Mechanical properties and biodegradability  

Microsoft Academic Search

Dialdehyde starch (DAS) and zein, a hydrophobic corn protein, were investigated to produce biodegradable plastics with improved water resistance and mechanical properties. In the study, dialdehyde starch and zein ratio, plasticizers, and degree of starch oxidation were examined. Increased molding temperature and level of starch oxidation decreased water absorption of the plastic. Tensile strength and Young's modulus increased with starch

Kris E. Spence; Jay-lin Jane; Anthony L. Pometto

1995-01-01

148

Seeing Color  

ERIC Educational Resources Information Center

Colors are powerful tools for engaging children, from the youngest years onward. We hang brightly patterned mobiles above their cribs and help them learn the names of colors as they begin to record their own ideas in pictures and words. Colors can also open the door to an invisible world of electromagnetism, even when children can barely imagine…

Texley, Juliana

2005-01-01

149

New North American truffles (Tuber spp.) and their ectomycorrhizal associations.  

PubMed

Recent surveys of belowground fungal biodiversity in México and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the Maculatum group, an understudied clade of small truffles with little apparent economic value. These species are among the more taxonomically challenge-ing in the genus. We collected Tuber castilloi, T. mexiusanum and T. guevarai as fruit bodies and ectomycorrhizae on Quercus spp. in forests of eastern México. Tuber mexiusanum has a particularly broad geographic range, being collected in eastern USA under Populus deltoides and in Minnesota and Iowa in mixed hardwood forests. T. walkeri is described from the upper midwestern USA, and T. lauryi and T. beyerlei occur in the western USA. PMID:22962353

Guevara, Gonzalo; Bonito, Gregory; Trappe, James M; Cázares, Efren; Williams, Gwendolyn; Healy, Rosanne A; Schadt, Christopher; Vilgalys, Rytas

2013-01-01

150

The expression of a recombinant glycolate dehydrogenase polyprotein in potato (Solanum tuberosum) plastids strongly enhances photosynthesis and tuber yield.  

PubMed

We have increased the productivity and yield of potato (Solanum tuberosum) by developing a novel method to enhance photosynthetic carbon fixation based on expression of a polyprotein (DEFp) comprising all three subunits (D, E and F) of Escherichia coli glycolate dehydrogenase (GlcDH). The engineered polyprotein retained the functionality of the native GlcDH complex when expressed in E. coli and was able to complement mutants deficient for the D, E and F subunits. Transgenic plants accumulated DEFp in the plastids, and the recombinant protein was active in planta, reducing photorespiration and improving CO2 uptake with a significant impact on carbon metabolism. Transgenic lines with the highest DEFp levels and GlcDH activity produced significantly higher levels of glucose (5.8-fold), fructose (3.8-fold), sucrose (1.6-fold) and transitory starch (threefold), resulting in a substantial increase in shoot and leaf biomass. The higher carbohydrate levels produced in potato leaves were utilized by the sink capacity of the tubers, increasing the tuber yield by 2.3-fold. This novel approach therefore has the potential to increase the biomass and yield of diverse crops. PMID:24605946

Nölke, Greta; Houdelet, Marcel; Kreuzaler, Fritz; Peterhänsel, Christoph; Schillberg, Stefan

2014-08-01

151

Effects of ?-amylolysis on the resistant starch formation of debranched corn starches.  

PubMed

Retrograded amylose is resistant to digestion by amylolytic enzymes, which is known as resistant starch type III (RS3). In this study we investigated the effect of ?-amylase hydrolysis on the formation and physicochemical properties of RS3 from debranched corn starches. Three types of corn starch (Hylon VII, Hylon V, and common corn) were first gelatinized and then hydrolyzed using ?-amylase to varying degrees. The resultant hydrolyzed starch was debranched with isoamylase and then exposed to temperature cycling to promote RS formation. A broad endotherm from approximately 45 to 120 °C and a small endotherm above 150 °C were noted for all retrograded starches. All three corn starches had increased RS contents after moderate ?-amylolysis, with Hylon V having the highest RS content at 70.7% after 4 h of ?-amylolysis. The results suggest that RS3 formation is affected by the starch composition as well as the starch structure and can be increased by moderate ?-amylolysis. PMID:22524584

Luckett, Curtis R; Wang, Ya-Jane

2012-05-01

152

Post-translational regulation of acid invertase activity by vacuolar invertase inhibitor affects resistance to cold-induced sweetening of potato tubers.  

PubMed

Cold-induced sweetening (CIS) is a serious post-harvest problem for potato tubers, which need to be stored cold to prevent sprouting and pathogenesis in order to maintain supply throughout the year. During storage at cold temperatures (below 10?°C), many cultivars accumulate free reducing sugars derived from a breakdown of starch to sucrose that is ultimately cleaved by acid invertase to produce glucose and fructose. When affected tubers are processed by frying or roasting, these reducing sugars react with free asparagine by the Maillard reaction, resulting in unacceptably dark-coloured and bitter-tasting product and generating the probable carcinogen acrylamide as a by-product. We have previously identified a vacuolar invertase inhibitor (INH2) whose expression correlates both with low acid invertase activity and with resistance to CIS. Here we show that, during cold storage, overexpression of the INH2 vacuolar invertase inhibitor gene in CIS-susceptible potato tubers reduced acid invertase activity, the accumulation of reducing sugars and the generation of acrylamide in subsequent fry tests. Conversely, suppression of vacuolar invertase inhibitor expression in a CIS-resistant line increased susceptibility to CIS. The results show that post-translational regulation of acid invertase by the vacuolar invertase inhibitor is an important component of resistance to CIS. PMID:22734927

McKenzie, Marian J; Chen, Ronan K Y; Harris, John C; Ashworth, Matthew J; Brummell, David A

2013-01-01

153

Grafting of 2-butenyl acrylate onto starch  

SciTech Connect

The monomer 2-butenyl acrylate was reacted with starch by exposure to either /sup 60/Co irradiation or ceric ion initiation. Monomer conversion in the presence of starch is greater than in the absence of starch, indicating that a starch initiating mechanism takes place for /sup 60/Co irradiated samples. Acetone extraction indicates little or no soluble homopolymer in the grafts. Portions of the samples soluble in dimethyl sulfoxide (DMSO) appear to be low-level 2-butenyl acrylate-grafted starch by infrared analysis. DMSO-insoluble portions (usually more than 50% of each sample) are somewhat more soluble in 1N NaOH at room temperature. This indicates that the 2-butenyl acrylate acts as an easily hydrolyzed crosslink for starch in samples containing as low as 5 wt% grafted poly(2-butenyl acrylate).

Abbott, T.P.; James, C.

1981-01-01

154

Symptomatic unilateral renal angiomyolipoma in a child with tuberous sclerosis.  

PubMed

We report a case of unilateral renal angiomyolipoma in a 10-year-old boy with tuberous sclerosis. The case is worthy of attention because the symptoms occurred at an early age and because the lesion was unilateral, the latter confirmed at 11-year follow-up. The presentation and treatment are discussed, and the pertinent literature is reviewed. The case demonstrates that it is of clinical importance to monitor renal involvement in children with tuberous sclerosis. PMID:11598456

Avolio, L; Savasta, S; Matteotti, C; Fusillo, M; Bragheri, R

2001-01-01

155

Symptomatic osteolipoma of the tuber cinereum. Case report.  

PubMed

The authors present a case of an ossified lipoma located at the tuber cinereum. Intracranial osteolipomas are rare lesions that occur in the region of the tuber cinereum. Almost all reported cases have been incidental autopsy findings. This report, however, involves a young girl who presented with an ovarian cyst and signs of precocious puberty, in whom a typical osteolipoma was surgically removed. This is the first case of hypothalamic osteolipoma presenting with endocrinological disturbances that has been published to date. PMID:11838812

Bognár, László; Bálint, Katalin; Bárdóczy, Zsolt

2002-02-01

156

Effect of cadmium on glutathione reductase in potato tubers  

Microsoft Academic Search

Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione reductase (GR) activity depending on cadmium ions concentrations, kind of tuber and time of incubation.\\u000a The increase of GR activity at 10 and 100 µmol·dcm?3 of CdCl2 solutions was marked in less resistant tissues of cv. Bintje after 24 hrs, and was slight in more resistant tissues

Andrzej Stroi?ski; Jan Kubi?; Ma?gorzata Zielezi?ska

1999-01-01

157

Color Quiz  

NSDL National Science Digital Library

Please take this Quiz. It is not that hard. Remember If you understand color, you will be able to use color in your artwork more effectively. For your Quiz please answer the 18 questions below. Here are some sites you have already seen that will help you answer the questions. Color Theory Color Vocabulary Wikipedia color theory You may write your answers down on a piece of paper or you can type the answers up. Make sure name, period, and date are on assignment ...

Freeman, Ms.

2006-02-14

158

Color Quiz  

NSDL National Science Digital Library

Please take this Quiz. It is not that hard. Remember If you understand color, you will be able to use color in your artwork more effectively. For your Quiz please answer the 18 questions below. Here are some sites you have already seen that will help you answer the questions. Color Theory Color Vocabulary Wikipedia color theory You may write your answers down on a piece of paper or you can type the answers up. Make sure name, period, and date are on assignment ...

Jolene

2008-09-29

159

Sucrose-to-Starch Metabolism in Tomato Fruit Undergoing Transient Starch Accumulation  

Microsoft Academic Search

lmmature green tomato (Lycopersicon esculenfum) fruits un- dergo a period of transient starch accumulation characterized by developmental changes in the activities of key enzymes in the sucrose (Suc)-to-starch metabolic pathway. Activities of Suc syn- thase, fructokinase, ADP-glucose (Clc) pyrophosphorylase, and sol- uble and insoluble starch synthases decline dramatically in parallel to the decrease in starch levels in the developing fruit.

Arthur A. Schaffer; Marina Petreikov

160

Flocculation of microalgae using cationic starch  

Microsoft Academic Search

Due to their small size and low concentration in the culture medium, cost-efficient harvesting of microalgae is a major challenge.\\u000a We evaluated the potential of cationic starch as a flocculant for harvesting microalgae using jar test experiments. Cationic\\u000a starch was an efficient flocculant for freshwater (Parachlorella, Scenedesmus) but not for marine microalgae (Phaeodactylum, Nannochloropsis). At high cationic starch doses, dispersion

Dries Vandamme; Imogen Foubert; Boudewijn Meesschaert; Koenraad Muylaert

2010-01-01

161

Color Terms and Color Concepts  

ERIC Educational Resources Information Center

In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

Davidoff, Jules

2006-01-01

162

Color Categories and Color Appearance  

ERIC Educational Resources Information Center

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

Webster, Michael A.; Kay, Paul

2012-01-01

163

A starch-accumulating mutant ofArabidopsis thalianadeficient in a chloroplastic starch-hydrolysing enzyme  

Microsoft Academic Search

Summary The aim of this work was to identify enzymes that partici- pate in the degradation of transitory starch in Arabidopsis. A mutant line was isolated by screening leaves at the end of the night for the presence of starch. The mutant had a higher starch content than the wild-type throughout the diurnal cycle. This accumulation was due to a

Samuel C. Zeeman; Fred Northrop; Alison M. Smith; Tom ap Rees

1998-01-01

164

Tubers from patients with tuberous sclerosis complex are characterized by changes in microtubule biology through ROCK2 signalling.  

PubMed

Most patients with tuberous sclerosis complex (TSC) develop cortical tubers that cause severe neurological disabilities. It has been suggested that defects in neuronal differentiation and/or migration underlie the appearance of tubers. However, the precise molecular alterations remain largely unknown. Here, by combining cytological and immunohistochemical analyses of tubers from nine TSC patients (four of them diagnosed with TSC2 germline mutations), we show that alteration of microtubule biology through ROCK2 signalling contributes to TSC neuropathology. All tubers showed a larger number of binucleated neurons than expected relative to control cortex. An excess of normal and altered cytokinetic figures was also commonly observed. Analysis of centrosomal markers suggested increased microtubule nucleation capacity, which was supported by the analysis of an expression dataset from cortical tubers and control cortex, and subsequently linked to under-expression of Rho-associated coiled-coil containing kinase 2 (ROCK2). Thus, augmented microtubule nucleation capacity was observed in mouse embryonic fibroblasts and human fibroblasts deficient in the Tsc2/TSC2 gene product, tuberin. Consistent with ROCK2 under-expression, microtubule acetylation was found to be increased with tuberin deficiency; this alteration was abrogated by rapamycin treatment and mimicked by HDAC6 inhibition. Together, the results of this study support the hypothesis that loss of TSC2 expression can alter microtubule organization and dynamics, which, in turn, deregulate cell division and potentially impair neuronal differentiation. PMID:24604753

Ferrer, Isidre; Mohan, Pooja; Chen, Helen; Castellsague, Joan; Gómez-Baldó, Laia; Carmona, Marga; García, Nadia; Aguilar, Helena; Jiang, Jihong; Skowron, Margaretha; Nellist, Mark; Ampuero, Israel; Russi, Antonio; Lázaro, Conxi; Maxwell, Christopher A; Pujana, Miguel Angel

2014-07-01

165

Color Analysis  

NASA Astrophysics Data System (ADS)

Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

Wrolstad, Ronald E.; Smith, Daniel E.

166

Color categories and color appearance  

PubMed Central

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

Webster, Michael A.; Kay, Paul

2011-01-01

167

Processing of Color Words Activates Color Representations  

ERIC Educational Resources Information Center

Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

Richter, Tobias; Zwaan, Rolf A.

2009-01-01

168

Measurement of the Water Potential of Stored Potato Tubers 1  

PubMed Central

A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential. Pressure chamber measurements, while useful for tubers with functional stolons, cannot be made on stored tubers. Measurements could be made on excised tissue pieces in a hygrometer chamber and with hygrometers implanted into tubers. We report here our evaluation of these hygrometric methods using a comparison with the pressure chamber on tubers harvested with stolons intact. In tubers of high water potential, measurements on excised tissue were as much as 0.5 megapascals lower than the pressure chamber, probably due to turgor-driven expansion of the sample when freed from constraints imposed by surrounding tissue. Good agreement (±0.05 megapascals) was found between the implanted hygrometer and the pressure chamber at potentials higher than ?0.5 megapascals. At lower water potentials, both hygrometer measurements were higher than the pressure chamber. Respirational heating of the tissue contributed to the increase in the excised tissue samples, but not with the implanted hygrometers because of the hygrometer design. The osmotic pressure balanced the pressure chamber measurement of potential at ?0.7 megapascals, but was too small to do so at lower potentials. At most, 25% of this discrepancy can be accounted for by dilution by apoplastic water. We believe that the pressure chamber measurement is too low at low water potentials and that the error is associated with air bubbles in the xylem. At low potentials air emerged from xylem vessels along with sap, and fewer xylem emitted sap as potentials decreased. PMID:16664511

Bland, William L.; Tanner, Champ B.

1985-01-01

169

Rheology and pressurised gyration of starch and starch-loaded poly(ethylene oxide).  

PubMed

This work investigates the rheology and spinning of starch and starch-loaded poly(ethylene oxide) (PEO) by pressurised gyration in order to prepare nanofibres. The spinning dope's rheological properties played a crucial role in fibre formation. Newtonian behaviour is observed in 1-20wt% starch suspensions and non-Newtonian behaviour is found in all the PEO-starch mixtures. Pressurised gyration of the starch suspensions produced beads only but PEO-starch mixtures generated fibres. The fibre diameter of the PEO-starch samples is shown to be a function of polymer concentration and rotating speed of the gyration system. Fibre formation can only be facilitated below a certain working pressure. The concentration of starch in the PEO-starch mixtures is crucial in defining whether beaded or continuous fibres were generated and this is related to the composition of the spinning dope. FT-IR, XRD and microscopy studies indicated very good miscibility of starch and PEO in the nanofibres. The storage modulus of the PEO-starch were also studied as a function of temperature (30-150°C) and showed interesting results but it was not possible to deduce general trends valid for the entire temperature range. PMID:25263892

Mahalingam, S; Ren, G G; Edirisinghe, M J

2014-12-19

170

Starch characterization and ethanol production of sorghum.  

PubMed

This study aimed to characterize and compare the chemical structures, physical properties, and enzymatic hydrolysis rates of five sorghum starches (6B73, 6C21, 6C69, 7R34, and X789) with that of corn starch (B73). Sorghum kernels consisted of 68.7-70.6% starch, more than the B73 corn (67.4%). Sorghum starches displayed higher gelatinization temperatures (66.6-67.4 °C), greater gelatinization enthalpy changes (13.0-14.0 J/g), and greater percentages of retrogradation (60.7-69.1%), but slower enzymatic hydrolysis rates (83.8-87.8% at 48 h) than the B73 corn starch (61.7 °C, 10.1 J/g, 51.5%, and 88.5%, respectively). These differences could result from the sorghum amylopectins consisting of fewer short branch chains (DP 6-12) (12.8-14.0%) than the corn amylopectin (15.0%). The sorghum starches showed greater peak and breakdown viscosities but lower setback viscosities than the B73 corn starch, resulting from the lower amylose content of the sorghum starches. After 96 h of fermentation, most ground sorghums exhibited lower ethanol yields (30.5-31.8%) than the ground B73 corn (31.8%). PMID:21604720

Ai, Yongfeng; Medic, Jelena; Jiang, Hongxin; Wang, Donghai; Jane, Jay-Lin

2011-07-13

171

Plasticization of corn starch by polyol mixtures  

Microsoft Academic Search

Polyol mixtures including mixture of conventional plasticizer glycerol and higher molecular weight polyol (HP) such as xylitol, sorbitol and maltitol were used to plasticize corn starch by melt-blending method, and effect of the polyol mixture on the pocessibility, microstructures, thermal stability and mechanical properties of these starch composites (SC) were investigated. The introduction of HP providing greater processing torque can

Xiuying Qiao; Zhongzhu Tang; Kang Sun

2011-01-01

172

Starch Wastewater Treatment with Effective Microorganisms Bacteria  

Microsoft Academic Search

Starch wastewater has high turbidity and COD, heavy odor after anaerobic processing. Discharging this kind of sewage could cause serious environmental pollution, and therefore it need to be treated and reached the national standard before discharge. This experiment based on the specific characteristics of starch wastewater. The process was designed as follows: after anaerobic hydrolysis prior to degradation of refractory

Zhou Guizhong; Li Jia; Fan Huiju; Sun Jing; Zhao Xiaoqing

2010-01-01

173

Tuberous Sclerosis Complex: A Brave New World?  

PubMed Central

Purpose of review Tuberous sclerosis complex (TSC) is a multiorgan genetic disease caused by mutations in the TSC1 or TSC2 genes. TSC has been recognized for many years as an important cause of severe neurological disease with patients suffering from epilepsy, developmental delay, autism, and psychiatric problems. During the last year there has been enormous advances in basic and translational research pertaining to TSC. Recent findings In this review, I discuss the basic science findings that position the TSC1 and TSC2 genes as critical regulators of the mTOR kinase within mTORC1. In addition, I will discuss the development of new animal models, translational data, and recent clinical trials using mTORC1 inhibitors such as rapamycin. Summary The past few years have seen spectacular advances that have energized TSC related research and challenged existing symptomatic treatments. While it remains to be seen whether use of mTORC1 inhibitors will revolutionize the care of patients with TSC, the application of basic and translational research towards a specific clinical disorder emphasizes the potential and promise of molecular medicine. PMID:20087180

Ess, Kevin C.

2010-01-01

174

Analysis of starch metabolism in chloroplasts.  

PubMed

Starch is a primary product of photosynthesis in the chloroplasts of many higher plants. It plays an important role in the day-to-day carbohydrate metabolism of the leaf, and its biosynthesis and degradation represent major fluxes in plant metabolism. Starch serves as a transient reserve of carbohydrate which is used to support respiration, metabolism, and growth at night when there is no production of energy and reducing power through photosynthesis, and no net assimilation of carbon. The chapter includes techniques to measure starch amount and its rate of biosynthesis, to determine its structure and composition, and to monitor its turnover. These methods can be used to investigate transitory starch metabolism in Arabidopsis, where they can be applied in combination with genetics and systems-level approaches to yield new insight into the control of carbon allocation generally, and starch metabolism specifically. The methods can also be applied to the leaves of other plants with minimal modifications. PMID:21863455

Hostettler, Carmen; Kölling, Katharina; Santelia, Diana; Streb, Sebastian; Kötting, Oliver; Zeeman, Samuel C

2011-01-01

175

Fed-batch fermentation of Tuber melanosporum for the hyperproduction of mycelia and bioactive Tuber polysaccharides.  

PubMed

For the first time, a fed-batch fermentation process of Tuber melanosporum was developed for the efficient production of bioactive mycelia and Tuber polysaccharides. Each 1.67 g/L of peptone and 8.33 g/L of yeast extract were added on day 3, 6, and 9, respectively, and sucrose was fed to maintain its concentration around 35-5 g/L when its residual level decreased to 10-5 g/L. Then, the maximal biomass, the production of extracellular polysaccharides (EPS) and intracellular polysaccharides (IPS) reached 53.72+/-2.57 g DW/L, 7.09+/-0.62 and 4.43+/-0.21 g/L, respectively. Compared with the batch culture conducted in the enriched medium, the biomass, the production of EPS and IPS were enhanced by 55.8%, 222.3% and 103.2%, respectively. Not only the cell density but also the production of EPS and IPS were the highest ever reported in truffle fermentation, and the biomass was also the highest as ever reported in mushroom fermentation. PMID:19303769

Liu, Qiao-Ning; Liu, Rui-Sang; Wang, Yi-Hua; Mi, Zhi-Yuan; Li, Dong-Sheng; Zhong, Jian-Jiang; Tang, Ya-Jie

2009-07-01

176

Diffusion features of white matter in tuberous sclerosis with tractography.  

PubMed

Normal-appearing white matter has been shown via diffusion tensor imaging to be affected in tuberous sclerosis complex. Under the hypothesis that some systems might be differentially affected, including the visual pathways and systems of social cognition, diffusion properties of various regions of white matter were compared. For 10 patients and 6 age-matched control subjects, 3 T magnetic resonance imaging was assessed using diffusion tensor imaging obtained in 35 directions. Three-dimensional volumes corresponding to the geniculocalcarine tracts were extracted via tractography, and two-dimensional regions of interest were used to sample other regions. Regression analysis indicated lower fractional anisotropy in the splenium of corpus callosum and geniculocalcarine tracts in tuberous sclerosis complex group, as well as lower axial diffusivity in the internal capsule, superior temporal gyrus, and geniculocalcarine tracts. Mean and radial diffusivity of the splenium of corpus callosum were higher in the tuberous sclerosis complex group. The differences in diffusion properties of white matter between tuberous sclerosis complex patients and control subjects suggest disorganized and structurally compromised axons with poor myelination. The visual and social cognition systems appear to be differentially involved, which might in part explain the behavioral and cognitive characteristics of the tuberous sclerosis complex population. PMID:20117745

Krishnan, Michelle L; Commowick, Olivier; Jeste, Shafali S; Weisenfeld, Neil; Hans, Arne; Gregas, Matthew C; Sahin, Mustafa; Warfield, Simon K

2010-02-01

177

Contamination of progeny tubers of potato plants by seed- and leaf-borne Erwinia carotovora  

Microsoft Academic Search

Marker strains ofE. carotovora var.carotovora and var.atroseptica spread from inoculated rotting tubers, buried at seed tuber level under potato plants in the field, to rhizosphere soil and progeny tubers late in the 1983 and 1984 growing seasons when weather conditions were wet. In 1982, tuber rotting was arrested in the dry soil conditions which prevailed after their burial and little

M. C. M. Pérombelon

1986-01-01

178

Evaluation of procedures for detection of pectolytic Erwinia spp. on potato tubers  

Microsoft Academic Search

The effectiveness of a tuber incubation method for detection ofErwinia carotovora var.atroseptica andE. carotovora var.carotovora in potato tubers was compared with a lenticel sampling procedure. In the first method, tubers were injured by puncturing\\u000a lenticels with sterile toothpicks, then wrapped in moist paper towels and polyvinylidene film, and placed in closed chambers\\u000a flushed with N2. In later experiments, wrapping tubers

S. H. De Boer; A. Kelman

1975-01-01

179

Interaction of tannins and other sorghum phenolic compounds with starch and effects on in vitro starch digestibility.  

PubMed

This study investigated interactions of sorghum proanthocyanidins (PAs) with starch molecules and the effect on in vitro starch digestibility. High tannin (predominant in PA), black (monomeric polyphenols), and white (low in polyphenols) sorghum phenolic extracts were mixed and cooked with starches varying in amylose content. Starch pasting properties, polyphenol profile, and resistant starch (RS) were determined. PAs decreased setback of normal starch and were least extractable after cooking with all starches. Pure amylose interacted more strongly with oligomeric and polymeric PA compared to amylopectin. The PA extract increased the net RS in normal starch by about 2 times more than the monomeric polyphenol extract; debranching amylopectin increased the difference by 4.3 times. Only treatments with PA increased RS in high amylose starch (52% higher than the control). Sorghum PAs interact strongly with starch, decreasing starch digestibility. The interactions appear to be specific to amylose and linear fragments of amylopectin, suggesting hydrophobic interactions are involved. PMID:23126482

Barros, Frederico; Awika, Joseph M; Rooney, Lloyd W

2012-11-21

180

Barley grain constituents, starch composition, and structure affect starch in vitro enzymatic hydrolysis.  

PubMed

The relationship between starch physical properties and enzymatic hydrolysis was determined using ten different hulless barley genotypes with variable carbohydrate composition. The ten barley genotypes included one normal starch (CDC McGwire), three increased amylose starches (SH99250, SH99073, and SB94893), and six waxy starches (CDC Alamo, CDC Fibar, CDC Candle, Waxy Betzes, CDC Rattan, and SB94912). Total starch concentration positively influenced thousand grain weight (TGW) (r(2) = 0.70, p < 0.05). Increase in grain protein concentration was not only related to total starch concentration (r(2) = -0.80, p < 0.01) but also affected enzymatic hydrolysis of pure starch (r(2) = -0.67, p < 0.01). However, an increase in amylopectin unit chain length between DP 12-18 (F-II) was detrimental to starch concentration (r(2) = 0.46, p < 0.01). Amylose concentration influenced granule size distribution with increased amylose genotypes showing highly reduced volume percentage of very small C-granules (<5 ?m diameter) and significantly increased (r(2) = 0.83, p < 0.01) medium sized B granules (5-15 ?m diameter). Amylose affected smaller (F-I) and larger (F-III) amylopectin chains in opposite ways. Increased amylose concentration positively influenced the F-III (DP 19-36) fraction of longer DP amylopectin chains (DP 19-36) which was associated with resistant starch (RS) in meal and pure starch samples. The rate of starch hydrolysis was high in pure starch samples as compared to meal samples. Enzymatic hydrolysis rate both in meal and pure starch samples followed the order waxy > normal > increased amylose. Rapidly digestible starch (RDS) increased with a decrease in amylose concentration. Atomic force microscopy (AFM) analysis revealed a higher polydispersity index of amylose in CDC McGwire and increased amylose genotypes which could contribute to their reduced enzymatic hydrolysis, compared to waxy starch genotypes. Increased ?-glucan and dietary fiber concentration also reduced the enzymatic hydrolysis of meal samples. An average linkage cluster analysis dendrogram revealed that variation in amylose concentration significantly (p < 0.01) influenced resistant starch concentration in meal and pure starch samples. RS is also associated with B-type granules (5-15 ?m) and the amylopectin F-III (19-36 DP) fraction. In conclusion, the results suggest that barley genotype SH99250 with less decrease in grain weight in comparison to that of other increased amylose genotypes (SH99073 and SH94893) could be a promising genotype to develop cultivars with increased amylose grain starch without compromising grain weight and yield. PMID:21462932

Asare, Eric K; Jaiswal, Sarita; Maley, Jason; Båga, Monica; Sammynaiken, Ramaswami; Rossnagel, Brian G; Chibbar, Ravindra N

2011-05-11

181

Assessing potato tubers for susceptibility to bacterial soft rot ( erwinia carotovora subsp. atroseptica )  

Microsoft Academic Search

A laboratory method is described of assessing the susceptibility of tubers to soft rot (Erwinia carotovora subsp.atroseptica). A bacterial suspension is placed in a hole drilled into the tuber cortex, the weighed tubers are placed in damp airtight boxes that are then gassed with nitrogen and incubated for 5 days at 25°C. The rotted tissue is washed out and the

W. F. Bourne; D. C. McCalmont; R. L. Wastie

1981-01-01

182

Burial depth distribution of fennel pondweed tubers ( Potamogeton pectinatus) in relation to foraging by Bewick's swans  

Microsoft Academic Search

Deep burial in the sediment of tubers of fennel pondweed (Potamogeton pectinatus) has been explained in terms of avoidance by escape against consumption by Bewick's swans (Cygnus columbianus bewickii) in autumn. We therefore expected changes in foraging pressure to ultimately result in a change in the tuber distribution across sediment depth. A trade-off underlies this idea: deep tubers are less

Bert Hidding; Bart A. Nolet; Mennobart R. van Eerden; Matthieu Guillemain; Marcel Klaassen

2009-01-01

183

Rapid estimation of potato tuber total protein content with coomassie brilliant blue G-250  

Microsoft Academic Search

A new method for measuring protein with Coo-massie Brilliant Blue G-250 has been adapted for use as a screening method in a potato tuber protein improvement breeding program. The method is simple, fast and inexpensive, and has successfully estimated the total protein content of a broad range of tuber genotypes having dissimilar amino acid profiles and tuber maturities. Correlation between

J. C. Snyder; S. L. Desborough

1978-01-01

184

[Case of colchicine intoxication caused by tubers of Gloriosa superba].  

PubMed

Gloriosa superba is one of the poisonous plants growing in Japan. It contains potent alkaloid such as colchicine which binds to tubulin and prevents it from forming microtubules that are part of the cytoskeleton in human cells. Ingestion of Gloriosa superba tubers causes severe and potentially fatal toxic effects. We report here a case of colchicine intoxication caused by tubers of Gloriosa superba. A 58-year-old male ingested about 25 g of Gloriosa superba tubers by mistake. He believed that it was wild yam. He developed abdominal pain, vomiting and diarrhea 30 minutes after the ingestion of the plant. Forty five hours later he was taken to the emergency department. Unfortunately he died due to progressive multiple organ failure about one hour after the admission. It was two days after Gloriosa superba ingestion. The clinical features and the aspect of the poisonous plants should be acquainted with people. PMID:20865911

Ide, Naohito; Suzuki, Ayumi; Suzuki, Eriko; Gotou, Seiichi

2010-09-01

185

Color Blind or Color Conscious?  

ERIC Educational Resources Information Center

A color-blind approach often signifies that an educator has not considered what racial/ethnic identity means to youngsters. Students want to find themselves reflected in the faces of teachers and other students. Color-conscious teachers seek out materials that positively reflect students' identities and initiate discussions about race and racism.…

Tatum, Beverly Daniel

1999-01-01

186

Effect of sorghum flour addition on in vitro starch digestibility, cooking quality, and consumer acceptability of durum wheat pasta.  

PubMed

Whole grain sorghum is a valuable source of resistant starch and polyphenolic antioxidants and its addition into staple food like pasta may reduce the starch digestibility. However, incorporating nondurum wheat materials into pasta provides a challenge in terms of maintaining cooking quality and consumer acceptability. Pasta was prepared from 100% durum wheat semolina (DWS) as control or by replacing DWS with either wholegrain red sorghum flour (RSF) or white sorghum flour (WSF) each at 20%, 30%, and 40% incorporation levels, following a laboratory-scale procedure. Pasta samples were evaluated for proximate composition, in vitro starch digestibility, cooking quality, and consumer acceptability. The addition of both RSF and WSF lowered the extent of in vitro starch digestion at all substitution levels compared to the control pasta. The rapidly digestible starch was lowered in all the sorghum-containing pastas compared to the control pasta. Neither RSF or WSF addition affected the pasta quality attributes (water absorption, swelling index, dry matter, adhesiveness, cohesiveness, and springiness), except color and hardness which were negatively affected. Consumer sensory results indicated that pasta samples containing 20% and 30% RSF or WSF had acceptable palatability based on meeting one or both of the preset acceptability criteria. It is concluded that the addition of wholegrain sorghum flour to pasta at 30% incorporation level is possible to reduce starch digestibility, while maintaining adequate cooking quality and consumer acceptability. PMID:25047068

Khan, Imran; Yousif, Adel M; Johnson, Stuart K; Gamlath, Shirani

2014-08-01

187

Color Theory  

NSDL National Science Digital Library

This Web site, developed by the Exploratories Project at Brown University, provides a series of applets to help users understand the various concepts in Color Theory. In the combined Color Mixing applet, undergraduate and high school students can discover how lights, paints, and filters interact. Users can learn about the properties of incoming light, frequency, and reflectance. The site also provides activities for metamers, Triple Cell Response, and much more. Anyone seeking help with color concepts will benefit from this educational, interactive Web site.

188

Familial bilateral periventricular nodular heterotopia mimics tuberous sclerosis.  

PubMed Central

A mother and daughter with an initial diagnosis of tuberous sclerosis are described. The daughter presented with partial seizures at the age of 8 months. Computed tomography showed uncalcified periventricular nodules which on magnetic resonance imaging were ovoid, almost contiguous, of grey matter density, and did not enhance with gadolinium. Brain imaging of her asymptomatic mother was similar. Absence of severe mental retardation, extracranial hamartomas, and depigmented patches distinguishes familial bilateral periventricular nodular heterotopia (FNH) from tuberous sclerosis. FNH is probably inherited as an X linked dominant with lethality in males. Images Figure 1 Figure 2 PMID:8787433

Jardine, P E; Clarke, M A; Super, M

1996-01-01

189

STARCH-EXCESS4 Is a Laforin-Like Phosphoglucan Phosphatase Required for Starch Degradation in Arabidopsis thaliana  

Microsoft Academic Search

Starch is the major storage carbohydrate in plants. It is comprised of glucans that form semicrystalline granules. Glucan phosphorylation is a prerequisite for normal starch breakdown, but phosphoglucan metabolism is not understood. A putative protein phosphatase encoded at the Starch Excess 4 (SEX4) locus of Arabidopsis thaliana was recently shown to be required for normal starch breakdown. Here, we show

Oliver Kotting; Diana Santelia; Christoph Edner; Simona Eicke; Tina Marthaler; Matthew S. Gentry; Sylviane Comparot-Moss; Jychian Chen; Alison M. Smith; Martin Steup; Gerhard Ritte; S. C. Zeeman

2009-01-01

190

Effects of starch synthase IIa gene dosage on grain, protein and starch in endosperm of wheat  

Microsoft Academic Search

Starch synthases (SS) are responsible for elongating the ?-1,4 glucan chains of starch. A doubled haploid population was generated\\u000a by crossing a line of wheat, which lacks functional ssIIa genes on each genome (abd), and an Australian wheat cultivar, Sunco, with wild type ssIIa alleles on each genome (ABD). Evidence has been presented previously indicating that the SGP-1 (starch granule

Christine Konik-Rose; Jenny Thistleton; Helene Chanvrier; Ihwa Tan; Peter Halley; Michael Gidley; Behjat Kosar-Hashemi; Hong Wang; Oscar Larroque; Joseph Ikea; Steve McMaugh; Ahmed Regina; Sadequr Rahman; Matthew Morell; Zhongyi Li

2007-01-01

191

Colorful Electrophoresis  

NSDL National Science Digital Library

In this activity, learners follow step-by-step instructions to build a gel electrophoresis chamber using inexpensive materials from local hardware and electronic stores. Then, learners follow instructions to simulate DNA electrophoresis using food colors from the kitchen pantry.

Utah, University O.

2012-01-01

192

Starch Synthesis in Arabidopsis. Granule Synthesis, Composition, and Structure1  

PubMed Central

The aim of this work was to characterize starch synthesis, composition, and granule structure in Arabidopsis leaves. First, the potential role of starch-degrading enzymes during starch accumulation was investigated. To discover whether simultaneous synthesis and degradation of starch occurred during net accumulation, starch was labeled by supplying 14CO2 to intact, photosynthesizing plants. Release of this label from starch was monitored during a chase period in air, using different light intensities to vary the net rate of starch synthesis. No release of label was detected unless there was net degradation of starch during the chase. Similar experiments were performed on a mutant line (dbe1) that accumulates the soluble polysaccharide, phytoglycogen. Label was not released from phytoglycogen during the chase indicating that, even when in a soluble form, glucan is not appreciably degraded during accumulation. Second, the effect on starch composition of growth conditions and mutations causing starch accumulation was studied. An increase in starch content correlated with an increased amylose content of the starch and with an increase in the ratio of granule-bound starch synthase to soluble starch synthase activity. Third, the structural organization and morphology of Arabidopsis starch granules was studied. The starch granules were birefringent, indicating a radial organization of the polymers, and x-ray scatter analyses revealed that granules contained alternating crystalline and amorphous lamellae with a periodicity of 9 nm. Granules from the wild type and the high-starch mutant sex1 were flattened and discoid, whereas those of the high-starch mutant sex4 were larger and more rounded. These larger granules contained “growth rings” with a periodicity of 200 to 300 nm. We conclude that leaf starch is synthesized without appreciable turnover and comprises similar polymers and contains similar levels of molecular organization to storage starches, making Arabidopsis an excellent model system for studying granule biosynthesis. PMID:12068097

Zeeman, Samuel C.; Tiessen, Axel; Pilling, Emma; Kato, K. Lisa; Donald, Athene M.; Smith, Alison M.

2002-01-01

193

Distribution of branches in whole starches from maize mutants deficient in starch synthase III.  

PubMed

An earlier study explored the possibility of analyzing the distribution of branches directly in native, whole starch without isolating the amylopectin component. The aim of this study was to explore if this approach can be extended to include starch mutants. Whole starches from du1 maize mutants deficient in starch synthase III (SSIII) with amylose content of ?30-40% were characterized and compared with the wild type of the common genetic background W64A. Clusters were produced from whole starch by hydrolysis with ?-amylase of Bacillus amyloliquefaciens. Their compositions of building blocks and chains were analyzed further by complete ?-amylolysis and by debranching, respectively, whereafter the products were subjected to gel permeation and anion exchange chromatography. The size and structure of the clusters were compared with those of their isolated amylopectin component. Whereas the whole starch of the wild type sample had a branched structure similar to that of its amylopectin component, the results showed that the du1 mutation resulted in more singly branched building blocks in the whole starch compared to the isolated amylopectin. This suggested that amylose and/or intermediate materials in whole du1 starches likely contributed to the composition of branches. This study explored an alternative procedure to characterize the composition of branches in the whole starch without fractionating the components. PMID:24684540

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2014-05-21

194

Electron microscopy and composition of raw acorn starch in relation to in vivo starch digestibility.  

PubMed

The structure and composition of starch play an important role as co-factors affecting raw starch digestibility: such features were investigated in raw acorn starch from the most diffused oak trees in the Mediterranean basin. A total of 620 whole ripe acorns from Holm (Quercus ilex L., n = 198), Downy (Quercus pubescens Willd., n = 207) and Cork (Quercus suber L., n = 215) oaks sampled on the Sardinia Isle (40° 56' 0'' N; 9° 4' 0'' E; 545 m above the mean sea level) in the same geographical area, were analyzed for their chemical composition. The starch contents ranged between 51.2% and 53.5% of dry matter. The starch granules displayed a spheroid/ovoid and cylindrical shape; on scanning electron microscopic (SEM) analyses, a bimodal distribution of starch granule size was observed both for Holm and Cork oak acorns, whereas the starch granules of Downy oak acorns showed diameters between 10.2 and 13.8 ?m. The specific amylose to amylopectin ratio of acorn starch was 25.8%, 19.5% and 34.0% in the Holm, Downy and Cork oaks, respectively. The (13)C Nuclear Magnetic Resonance (NMR) signal analysis displayed a pivotal spectrum for the identification of the amylose peaks in raw acorn starch, as a basis for the amylose to amylopectin ratio determination. PMID:23660700

Cappai, Maria Grazia; Alesso, Giuseppe Andrea; Nieddu, Giuseppa; Sanna, Marina; Pinna, Walter

2013-06-01

195

Biotechnological relevance of starch-degrading enzymes  

SciTech Connect

Traditional enzymes, such as the amylases and the proteases, have been improved, novel applications have been found and new and valuable products have been marketed. The enzymatic hydrolysis of starch is described in some detail. (Refs. 8).

Stewart, G.G.

1987-01-01

196

Modification of starch during malting of sorghum  

E-print Network

STARCH DEGRADATION AND LOSS STARCH QUANTIFICATION USING HPSEC. . . . . . . . . . . . LOW MOLECULAR WEIGHT CARBOHYDRATE QUANTIFICATION USING HPLC EFFECT OF MALTING ON NUTRITIVE VALUE OF SORGHUM OPAQUE BEER PRODUCTION LAGER BEER PRODUCTION LAGER... 38. Apparent molecular weight standard curve for HPSEC . 139 39. Glucose, fructose, maltose, and standard curves for HPLC analysis . . 142 40. Oligosaccharide standard curve for HPLC analysis . . 147 LIST OF FIGURES Figure 1. Dry matter losses...

Floyd, Cherie Diane

2012-06-07

197

Hamartomas of the Tuber cinereum and Precocious Puberty  

Microsoft Academic Search

5 cases of true precocious puberty (TPP) of cerebral origin are presented. The clinical and radiological features and the protracted follow-up allow, also in view of the literature, a highly presumptive diagnosis of a hamartoma of the tuber cinereum. The high incidence of these lesions in cases of TPP is emphasized, together with the importance of early neuroradiological assessment.

Giorgio Frank; Emanuele Cacciari; Gianfranco Cristi; Elisabetta Frejaville; Ercole Galassi; Piero Pirazzoli; Franco Frank; Giulio Gaist; Alessandro Cicognani; Antonio Balsamo

1982-01-01

198

Colchicine cardiotoxicity following ingestion of Gloriosa superba tubers.  

PubMed

The clinical features of colchicine toxicity in a patient following ingestion of Gloriosa superba tubers are described. Gastroenteritis, acute renal failure, cardiotoxicity and haematological abnormalities were the main toxic manifestations. There was no hypotension and no neurological manifestations. Electrocardiographic changes were noteworthy and have not been reported previously. PMID:2694138

Mendis, S

1989-10-01

199

Colchicine cardiotoxicity following ingestion of Gloriosa superba tubers.  

PubMed Central

The clinical features of colchicine toxicity in a patient following ingestion of Gloriosa superba tubers are described. Gastroenteritis, acute renal failure, cardiotoxicity and haematological abnormalities were the main toxic manifestations. There was no hypotension and no neurological manifestations. Electrocardiographic changes were noteworthy and have not been reported previously. Images Figure 1 Figure 2 PMID:2694138

Mendis, S.

1989-01-01

200

Endometrial Adenocarcinoma Presenting in a Premenopausal Patient with Tuberous Sclerosis  

ERIC Educational Resources Information Center

Background: Endometrial adenocarcinoma is very uncommon in women under 40 years of age. Case: A 39-year-old woman with tuberous sclerosis and severe intellectual disability presented with irregular bleeding unresponsive to oral contraceptive therapy. She was subsequently found to have a deeply invasive endometrial adenocarcinoma. Conclusion:…

Jaffe, J. S.; Chambers, J. T.

2005-01-01

201

Soluble Sugar Concentrations Associated with Tuber and Winter Bud Sprouting  

Microsoft Academic Search

Many aquatic weeds rely on vegetative structures for surviv- al and propagation, rather than seeds. American pondweed ( Potamogeton nodosus Poiret) winter buds , and hydrilla ( Hydril- la verticillata (L.f.) Royle, monoecious and dioecious types) tubers were allowed to sprout in water in the dark. At two-to- three day intervals individual propagules and dependent shoots were analyzed for soluble

D. F. SPENCER; F. J. RYAN; L. AUNG; G. G. KSANDER

2001-01-01

202

Genetics and Molecular Biology of Tuberous Sclerosis Complex  

PubMed Central

Tuberous Sclerosis Complex is a multisystem disorder exhibiting a wide range of manifestations characterized by tumour-like lesions called hamartomas in the brain, skin, eyes, heart, lungs and kidneys. Tuberous Sclerosis Complex is genetically determined with an autosomal dominant inheritance and is caused by inactivating mutations in either the TSC1 or TSC2 genes. TSC1/2 genes play a fundamental role in the regulation of phosphoinositide 3-kinase (PI3K) signalling pathway, inhibiting the mammalian target of rapamycin (mTOR) through activation of the GTPase activity of Rheb. Mutations in TSC1/2 genes impair the inhibitory function of the hamartin/tuberin complex, leading to phosphorylation of the downstream effectors of mTOR, p70 S6 kinase (S6K), ribosomal protein S6 and the elongation factor binding protein 4E-BP1, resulting in uncontrolled cell growth and tumourigenesis. Despite recent promising genetic, diagnostic, and therapeutic advances in Tuberous Sclerosis Complex, continuing research in all aspects of this complex disease will be pivotal to decrease its associated morbidity and mortality. In this review we will discuss and analyse all the important findings in the molecular pathogenesis of Tuberous Sclerosis Complex, focusing on genetics and the molecular mechanisms that define this multisystemic disorder. PMID:19506736

Napolioni, Valerio; Curatolo, Paolo

2008-01-01

203

Color vision test  

MedlinePLUS

... test checks your ability to distinguish between different colors. ... Eye test - color; Vision test - color; Ishihara color vision test ... be asked to determine the intensity of a color, especially in one eye compared to the other. This is often tested ...

204

Characterization of edible starch-chitosan film and its application in the storage of Mongolian cheese.  

PubMed

The physicochemical, mechanical, optical and structural properties based on different amylose content starch-chitosan films with the addition of hydrophilic glycerol and hydrophobic perilla oil were investigated, and the effects of the starch-chitosan coating on the physicochemical and microbial properties of Mongolian cheese were evaluated. The films were formed by casting method. Results showed that the incorporation of perilla oil resulted in a decrease in moisture content, solubility and mechanical properties and an increase in total color difference (?E*). High water vapor permeability (WVP), good transparency and low solubility were observed with the addition of glycerol. Meanwhile, the film based on mung bean starch-chitosan (MSC) exhibited higher moisture content, WVP values, ?E* and less transparency than that based on water chestnut starch-chitosan (WSC). The morphology of films was also different based on MSC/WSC. The shelf life extension of Mongolian cheese was evaluated at 8 °C. The results showed that the cheese coated by WSC film containing perilla oil presented better treatment performance in terms of microbial growth delay, weight loss and shelf life length. PMID:23500443

Mei, Jun; Yuan, Yilin; Wu, Yan; Li, Yunfei

2013-06-01

205

Radiation grafting of styrene on starch with high efficiency  

NASA Astrophysics Data System (ADS)

Wheat starch grafted with polystyrene (PS-g-starch) was synthesized via polymerization grafting of styrene on starch by gamma-ray. The effects of starch/styrene weight ratio, and amount of applied doses (5-40 kGy) on the percentage of grafting, G (%), were investigated. The results showed that G (%) increased with increasing starch content. The optimum condition, starch/styrene weight ratio 1/3 and the applied dose 10 kGy, led to 252.9% of grafting. The obtained graft copolymer was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, and scanning electron microscopy. FTIR spectroscopy as well as the XRD analysis exhibited the changes in chemical and crystalline structure of starch after grafting reaction. TGA demonstrated the changes in thermal stability of PS-g-starch copolymer. SEM micrographs indicated porous patches of PS adhering on the starch.

Sheikh, N.; Akhavan, A.; Ataeivarjovi, E.

2013-04-01

206

Psychopathology in Tuberous Sclerosis: An Overview and Findings in a Population-Based Sample of Adults with Tuberous Sclerosis  

ERIC Educational Resources Information Center

Background: Tuberous sclerosis (TS) is a multi- system disorder with complex genetics. The neurodevelopmental manifestations of TS are responsible for considerable morbidity. The prevalence of epilepsy and intellectual disabilities among individuals with TS have been well described. Ours is the first study that explores the prevalence and pattern…

Raznahan, A.; Joinson, C.; O'Callaghan, F.; Osborne, J. P.; Bolton, P. F.

2006-01-01

207

Plantain and banana starches: granule structural characteristics explain the differences in their starch degradation patterns.  

PubMed

Different banana cultivars were used to investigate the influences of starch granule structure and hydrolases on degradation. The highest degrees of starch degradation were observed in dessert bananas during ripening. Scanning electron microscopy images revealed smooth granule surface in the green stage in all cultivars, except for Mysore. The small and round granules were preferentially degraded in all of the cultivars. Terra demonstrated a higher degree of crystallinity and a short amylopectin chain length distribution, resulting in high starch content in the ripe stage. Amylose content and the crystallinity index were more strongly correlated than the distribution of amylopectin branch chain lengths in banana starches. ?- and ?-amylase activities were found in both forms, soluble in the pulp and associated with the starch granule. Starch-phosphorylase was not found in Mysore. On the basis of the profile of ?-amylase in vitro digestion and the structural characteristics, it could be concluded that the starch of plantains has an arrangement of granules more resistant to enzymes than the starch of dessert bananas. PMID:21591784

Soares, Claudinéia Aparecida; Peroni-Okita, Fernanda Helena Gonçalves; Cardoso, Mateus Borba; Shitakubo, Renata; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

2011-06-22

208

Starches from different botanical sources II: Contribution of starch structure to swelling and pasting properties  

Microsoft Academic Search

Swelling and pasting properties of 15 starches from different plant origins were studied to elucidate their relationship with structural features using simple and multiple regression analyses. Avoidance of additional effects of starch minor components showed that swelling power and pasting parameters were associated with the ratio of the relative molar distribution of amylopectin branch-chains with a degree of polymerization (DP)

Sathaporn Srichuwong; Titi Candra Sunarti; Takashi Mishima; Naoto Isono; Makoto Hisamatsu

2005-01-01

209

Heterogeneity of starch granules and the effect of granule channelization on starch modification  

Microsoft Academic Search

This paper reviews the discovery of channels ID starch granules and progress of research on their effects on granule modification and digestibility, their nature, hypotheses on how they are formed and why they are present, and genetic control of their occurrence. Emphasized ID the relationship of channels to starch derivatization. Channelization ID presented as additional evidence of the heterogenous nature

John E. Fannon; Jonathan A. Gray; Ninik Gunawan; Kerry C. Huber; James N. BeMiller

2004-01-01

210

Preparation and characterization of resistant starch III from elephant foot yam (Amorphophallus paeonifolius) starch.  

PubMed

The purpose of this study was to assess the properties of resistant starch (RS) III prepared from elephant foot yam starch using pullulanase enzyme. Native and gelatinized starches were subjected to enzymatic hydrolysis (pullulanase, 40 U/g per 10h), autoclaved (121°C/30 min), stored under refrigeration (4°C/24h) and then lyophilized. After preparation of resistant starch III, the morphological, physical, chemical and functional properties were assessed. The enzymatic and retrogradation process increased the yield of resistant starch III from starch with a concomitant increase increase in its water absorption capacity and water solubility index. A decrease in swelling power was observed due to the hydrolysis and thermal process. Te reduced pasting properties and hardness of resistant starch III were associated with the disintegration of starch granules due to the thermal process. The viscosity was found to be inversely proportional to the RS content in the sample. The thermal properties of RS increased due to retrogradation and recrystallization (P<0.05). PMID:24594151

Reddy, Chagam Koteswara; Haripriya, Sundaramoorthy; Noor Mohamed, A; Suriya, M

2014-07-15

211

Cecropia peltata accumulates starch or soluble glycogen by differentially regulating starch biosynthetic genes.  

PubMed

The branched glucans glycogen and starch are the most widespread storage carbohydrates in living organisms. The production of semicrystalline starch granules in plants is more complex than that of small, soluble glycogen particles in microbes and animals. However, the factors determining whether glycogen or starch is formed are not fully understood. The tropical tree Cecropia peltata is a rare example of an organism able to make either polymer type. Electron micrographs and quantitative measurements show that glycogen accumulates to very high levels in specialized myrmecophytic structures (Müllerian bodies), whereas starch accumulates in leaves. Compared with polymers comprising leaf starch, glycogen is more highly branched and has shorter branches--factors that prevent crystallization and explain its solubility. RNA sequencing and quantitative shotgun proteomics reveal that isoforms of all three classes of glucan biosynthetic enzyme (starch/glycogen synthases, branching enzymes, and debranching enzymes) are differentially expressed in Müllerian bodies and leaves, providing a system-wide view of the quantitative programming of storage carbohydrate metabolism. This work will prompt targeted analysis in model organisms and cross-species comparisons. Finally, as starch is the major carbohydrate used for food and industrial applications worldwide, these data provide a basis for manipulating starch biosynthesis in crops to synthesize tailor-made polyglucans. PMID:23632447

Bischof, Sylvain; Umhang, Martin; Eicke, Simona; Streb, Sebastian; Qi, Weihong; Zeeman, Samuel C

2013-04-01

212

Colored Shadows  

NSDL National Science Digital Library

This activity demonstrates the additive properties of light. Different-colored lights are shown on the same spot on a screen so that the reflecting light is white. Colored shadows, however, can be made by holding an object between the light sources and the screen. The site provides an explanation for how this occurs along with extension activities and information about the eyeâÂÂs retina. Materials needed and assembly instructions are also included. This activity is part of Exploratorium's Science Snacks series.

2008-06-19

213

Potential aromatic compounds as markers to differentiate between Tuber melanosporum and Tuber indicum truffles.  

PubMed

The Tuber indicum (Chinese truffle) and Tuber melanosporum (Black truffle) species are morphologically very similar but their aromas are very different. The black truffle aroma is much more intense and complex, and it is consequently appreciated more gastronomically. This work tries to determine whether the differences between the aromatic compounds of both species are sufficiently significant so as to apply them to fraud detection. An olfactometric evaluation (GC-O) of T. indicum was carried out for the first time. Eight important odorants were identified. In order of aromatic significance, these were: 1-octen-3-one and 1-octen-3-ol, followed by two ethyl esters (ethyl isobutyrate and ethyl 2-methylbutyrate), 3-methyl-1-butanol, isopropyl acetate, and finally the two sulfides dimethyldisulfide (DMDS) and dimethylsulfide (DMS). A comparison of this aromatic profile with that of T. melanosporum revealed the following differences: T. indicum stood out for the significant aromatic contribution of 1-octen-3-one and 1-octen-3-ol (with modified frequencies (MF%) of 82% and 69%, respectively), while in the case of T. melanosporum both had modified frequencies of less than 30%. Ethyl isobutyrate, ethyl 2-methylbutyrate and isopropyl acetate were also significantly higher, while DMS and DMDS had low MF (30-40%) compared to T. melanosporum (>70%). The volatile profiles of both species were also studied by means of headspace solid-phase microextraction (HS-SPME-GC-MS). This showed that the family of C8 compounds (3-octanone, octanal, 1-octen-3-one, 3-octanol and 1-octen-3-ol) is present in T. indicum at much higher levels. The presence of 1-octen-3-ol was higher by a factor of about 100, while 1-octen-3-one was detected in T. indicum only (there was no chromatographic signal in T. melanosporum). As well as showing the greatest chromatographic differences, these two compounds were also the most powerful from the aromatic viewpoint in the T. indicum olfactometry. Therefore, either of the two chromatographic methods (GC-O or HS-SPME-GC-MS), together or separately, could be used as a screening technique to distinguish between T. indicum and T. melanosporum and thus avoid possible fraud. PMID:23768334

Culleré, Laura; Ferreira, Vicente; Venturini, María E; Marco, Pedro; Blanco, Domingo

2013-11-01

214

No Latex Starch Utilization in Euphorbia esula L.  

PubMed

Utilization of leaf, stem, root, and latex starch was monitored in Euphorbia esula L. plants. Leaf, stem, and root starch decreased rapidly during a 52 day light starvation period while latex starch did not. Scanning electron and light microscope studies provided additional evidence that no changes in latex starch granules had occurred. Amylase activity (6.6 units per milligram protein) could be isolated from latex. However, latex starch granules were extremely resistant to enzymic hydrolysis by latex amylases, Bacillus subtilis alpha-amylase, and by amyloglucosidase from Aspergillus niger. Results indicate that latex starch grains do not function as utilizable carbohydrate in this species under these conditions. PMID:16664883

Nissen, S J; Foley, M E

1986-06-01

215

Effects of cooking methods and starch structures on starch hydrolysis rates of rice.  

PubMed

This study aimed to understand effects of different cooking methods, including steamed, pilaf, and traditional stir-fried, on starch hydrolysis rates of rice. Rice grains of 3 varieties, japonica, indica, and waxy, were used for the study. Rice starch was isolated from the grain and characterized. Amylose contents of starches from japonica, indica, and waxy rice were 13.5%, 18.0%, and 0.9%, respectively. The onset gelatinization temperature of indica starch (71.6 °C) was higher than that of the japonica and waxy starch (56.0 and 56.8 °C, respectively). The difference was attributed to longer amylopectin branch chains of the indica starch. Starch hydrolysis rates and resistant starch (RS) contents of the rice varieties differed after they were cooked using different methods. Stir-fried rice displayed the least starch hydrolysis rate followed by pilaf rice and steamed rice for each rice variety. RS contents of freshly steamed japonica, indica, and waxy rice were 0.7%, 6.6%, and 1.3%, respectively; those of rice pilaf were 12.1%, 13.2%, and 3.4%, respectively; and the stir-fried rice displayed the largest RS contents of 15.8%, 16.6%, and 12.1%, respectively. Mechanisms of the large RS contents of the stir-fried rice were studied. With the least starch hydrolysis rate and the largest RS content, stir-fried rice would be a desirable way of preparing rice for food to reduce postprandial blood glucose and insulin responses and to improve colon health of humans. PMID:23772830

Reed, Michael O; Ai, Yongfeng; Leutcher, Josh L; Jane, Jay-lin

2013-07-01

216

Profiling Color  

Microsoft Academic Search

This paper examines philosophically the nature and possible moral justification of racial profiling in terms of color profiling.\\u000a Precisely what is such profiling, and can it ever be morally justified? If so, under what conditions is it morally justified?

J. Angelo Corlett

2011-01-01

217

Skin Color, Scab Sensitivity and Field Performance of Lines Derived from Spontaneous Chimeras of Red Norland Potato  

Microsoft Academic Search

On the Canadian prairies, consumers favor red-skinned potatoes (Solanum tuberosum), with Red Norland representing the most widely grown red-skinned cultivar. However, the skin color of Red Norland is not\\u000a as red as desired, particularly after extended storage. In 2004 three Red Norland tubers which appeared to have zones of darker\\u000a skin color were discovered. Plants were grown from sprouts taken

Doug Waterer; Hanny Elsadr; Mary-Lee McArthur

2011-01-01

218

Induction of vacuolar invertase inhibitor mRNA in potato tubers contributes to cold-induced sweetening resistance and includes spliced hybrid mRNA variants  

PubMed Central

Cold storage of tubers of potato (Solanum tuberosum L.) compromises tuber quality in many cultivars by the accumulation of hexose sugars in a process called cold-induced sweetening. This is caused by the breakdown of starch to sucrose, which is cleaved to glucose and fructose by vacuolar acid invertase. During processing of affected tubers, the high temperatures involved in baking and frying cause the Maillard reaction between reducing sugars and free amino acids, resulting in the accumulation of acrylamide. cDNA clones with deduced proteins homologous to known invertase inhibitors were isolated and the two most abundant forms, termed INH1 and INH2, were shown to possess apoplastic and vacuolar localization, respectively. The INH2 gene showed developmentally regulated alternative splicing, so, in addition to the INH2? transcript encoding the full-length protein, two hybrid mRNAs (INH2?*A and INH2?*B) that encoded deduced vacuolar invertase inhibitors with divergent C-termini were detected, the result of mRNA splicing of an upstream region of INH2 to a downstream region of INH1. Hybrid RNAs are common in animals, where they may add to the diversity of the proteome, but are rarely described in plants. During cold storage, INH2? and the hybrid INH2? mRNAs accumulated to higher abundance in cultivars resistant to cold-induced sweetening than in susceptible cultivars. Increased amounts of invertase inhibitor may contribute to the suppression of acid invertase activity and prevent cleavage of sucrose. Evidence for increased RNA splicing activity was detected in several resistant lines, a mechanism that in some circumstances may generate a range of proteins with additional functional capacity to aid adaptability. PMID:21393382

Brummell, David A.; Chen, Ronan K. Y.; Harris, John C.; Zhang, Huaibi; Hamiaux, Cyril; Kralicek, Andrew V.; McKenzie, Marian J.

2011-01-01

219

Functionality of porous starch obtained by amylase or amyloglucosidase treatments.  

PubMed

Porous starch is attracting very much attention for its absorption and shielding ability in many food applications. The effect of two different enzymes, fungal ?-amylase (AM) or amyloglucosidase (AMG), on corn starch at sub-gelatinization temperature was studied as an alternative to obtain porous starch. Biochemical features, thermal and structural analyses of treated starches were studied. Microscopic analysis of the granules confirmed the enzymatic modification of the starches obtaining porous structures with more agglomerates in the case of AMG treated starches. Several changes in thermal properties and hydrolysis kinetics were observed in enzymatically modified starches. Hydration properties were significantly affected by enzymatic modification being greater influenced by AMG activity, and the opposite trend was observed in the pasting properties. Overall, results showed that enzymatic modification at sub-gelatinization temperatures really offer an attractive alternative for obtaining porous starch granules to be used in a variety of foods applications. PMID:24299846

Dura, A; B?aszczak, W; Rosell, C M

2014-01-30

220

[Manifestation of tuberous sclerosis in the ENT area].  

PubMed

Tuberous sclerosis (Bourneville-Pringle's disease) is a rare, largely autosomal dominant neurocutaneous disease. The disease can also result from spontaneous mutations. Although strongly variable in its manifestation, manifestations are typically characterized by involvement of the central nervous system (early childhood seizures), skin (facial angiofibromas) and kidneys (angiomyolipomas). In the case described, a 67-year-old female patient complained exclusively of obstructed nasal breathing that was found to be due to angiofibromas in the nasal vestibule. Oral fibromas were asymptomatic, while fibromas in the facial region resulted in some cosmetic changes. This exclusively ENT manifestation of a patient with tuberous sclerosis has not been described previously. As treatment, the fibromas were ablated by an Nd:YAG laser under local anesthesia. Other therapeutic options are described. Additional clarification of all organ manifestations is advisable in view of numerous possible pathologies present. Genetic consultation is also recommended, particularly for patients with an oligosymptomatic variant. PMID:8707632

Helling, K; Flöttmann, T; Schmitt-Gräff, A; Scherer, H

1996-05-01

221

Thermoplastic starch films reinforced with talc nanoparticles.  

PubMed

Nanocomposite films of thermoplastic corn starch (TPS) with talc particles were obtained by thermo-compression in order to study the effect of filler on structure, optical, and thermal properties. Talc increased the films rigid phase, thus their cross-sections resulted more irregular. Talc preferential orientation within matrix and good compatibility between particles and TPS was observed by SEM. Slight crystalline structure changes in TPS matrix were measured by XRD and DSC, due to talc nucleating effect. Randomly dispersed talc nanoagglomerates and individual platelets were assessed by TEM. Laminar morphology and nano-sized particles allowed that nanocomposite films were optically transparent. TPS-talc films resulted heterogeneous materials, presenting domains rich in glycerol and others rich in starch. Talc incorporation higher than 3%, w/w increased softening resistance of the nanocomposites as stated by DMA. Relaxation temperatures of glycerol-rich phase shifted to higher values since talc reduces the mobility of starch chains. PMID:23648028

Castillo, Luciana; López, Olivia; López, Cintia; Zaritzky, Noemí; García, M Alejandra; Barbosa, Silvia; Villar, Marcelo

2013-06-20

222

Initiation and culture of potato tuber callus tissue with picloram  

Microsoft Academic Search

Callus cultures of 7 potato cultivars were initiated from tuber tissue and maintained on Gelrite-solidified media with 1–20 µM picloram as the only PGR. Ten µM picloram was the optimal concentration for callus induction. By 4–6 weeks after explanting, there was sufficient callus produced for subculture to maintenance media which contained 1–20 µM picloram as the only PGR. When grown

Steven R. Hagen; Duane LeTourneau; Paul Muneta; Janice Brown

1990-01-01

223

TuberQ: a Mycobacterium tuberculosis protein druggability database.  

PubMed

In 2012 an estimated 8.6 million people developed tuberculosis (TB) and 1.3 million died from the disease [including 320?000 deaths among human immunodeficiency virus (HIV)-positive people]. There is an urgent need for new anti-TB drugs owing to the following: the fact that current treatments have severe side effects, the increasing emergence of multidrug-resistant strains of Mycobacterium tuberculosis (Mtb), the negative drug-drug interactions with certain HIV (or other disease) treatments and the ineffectiveness against dormant Mtb. In this context we present here the TuberQ database, a novel resource for all researchers working in the field of drug development in TB. The main feature of TuberQ is to provide a druggability analysis of Mtb proteins in a consistent and effective manner, contributing to a better selection of potential drug targets for screening campaigns and the analysis of targets for structure-based drug design projects. The structural druggability analysis is combined with features related to the characteristics of putative inhibitor binding pockets and with functional and biological data of proteins. The structural analysis is performed on all available unique Mtb structures and high-quality structural homology-based models. This information is shown in an interactive manner, depicting the protein structure, the pockets and the associated characteristics for each protein. TuberQ also provides information about gene essentiality information, as determined from whole cell-based knockout experiments, and expression information obtained from microarray experiments done in different stress-related conditions. We hope that TuberQ will be a powerful tool for researchers working in TB and eventually will lead to the identification of novel putative targets and progresses in therapeutic activities. Database URL: http://tuberq.proteinq.com.ar/ PMID:24816183

Radusky, Leandro; Defelipe, Lucas A; Lanzarotti, Esteban; Luque, Javier; Barril, Xavier; Marti, Marcelo A; Turjanski, Adrián G

2014-01-01

224

Expression and activity of antioxidant enzymes during potato tuber dormancy  

Microsoft Academic Search

Summary  The expression of antioxidant genes has been analyzed in a potato plant and during tuber dormancy. Manganese superoxide dismutase\\u000a (MnSOD), cytosolic copper and zinc superoide dismutase (Cu\\/ZnSOD), catalase class II, cytosolic ascorbate peroxidase (APX)\\u000a and glutathione peroxidase (GPX) are expressed at the RNA level in all the contexts analyzed. By contrast, the expression\\u000a of the iron superoxide dismutase (FeSOD) and

J. A. Rojas-Beltran; F. Dejaeghere; M. Abd Alla Kotb; P. Du Jardin

2000-01-01

225

Hepatotoxicity of tubers of Indian Kudzu ( Pueraria tuberosa) in rats  

Microsoft Academic Search

Methanolic extract of tubers of Pueraria tuberosa Linn. (Fabaceae) (PTME) has been tested for hepatoxicity in rats. In acute study, PTME (100–400mg\\/100g BW, given orally) showed LD50 at 227.5mg. For sub-chronic study, its repeated doses (5–100mg\\/100g BW, for 30days), significantly increased hepatic enzymes in blood, sinusoidal congestion, disruption of central vein, inflammatory cell infiltration and hepatocellular necrosis in liver in

Nagwani Santosh; Kumar Mohan; Singh Royana; Tripathi B. Yamini

2010-01-01

226

Herbicide Residues and Nitrate Concentration in Tubers of Table Potatoes  

Microsoft Academic Search

This study examined Wiking-cultivar table potato tubers in a field experiment conducted between 2002 and 2004 using a rye complex soil. The experimental factors included (a) two methods of tillage, including traditional and simplified, as well as (b) seven methods of cultivation with the use of herbicides as follows: 1, control without herbicides; 2, Plateen 41.5 WG; 3, Plateen 41.5

Krystyna Zarzecka; Marek Guga?a; Iwona Mystkowska

2010-01-01

227

TuberQ: a Mycobacterium tuberculosis protein druggability database  

PubMed Central

In 2012 an estimated 8.6 million people developed tuberculosis (TB) and 1.3 million died from the disease [including 320?000 deaths among human immunodeficiency virus (HIV)-positive people]. There is an urgent need for new anti-TB drugs owing to the following: the fact that current treatments have severe side effects, the increasing emergence of multidrug-resistant strains of Mycobacterium tuberculosis (Mtb), the negative drug–drug interactions with certain HIV (or other disease) treatments and the ineffectiveness against dormant Mtb. In this context we present here the TuberQ database, a novel resource for all researchers working in the field of drug development in TB. The main feature of TuberQ is to provide a druggability analysis of Mtb proteins in a consistent and effective manner, contributing to a better selection of potential drug targets for screening campaigns and the analysis of targets for structure-based drug design projects. The structural druggability analysis is combined with features related to the characteristics of putative inhibitor binding pockets and with functional and biological data of proteins. The structural analysis is performed on all available unique Mtb structures and high-quality structural homology-based models. This information is shown in an interactive manner, depicting the protein structure, the pockets and the associated characteristics for each protein. TuberQ also provides information about gene essentiality information, as determined from whole cell–based knockout experiments, and expression information obtained from microarray experiments done in different stress-related conditions. We hope that TuberQ will be a powerful tool for researchers working in TB and eventually will lead to the identification of novel putative targets and progresses in therapeutic activities. Database URL: http://tuberq.proteinq.com.ar/ PMID:24816183

Radusky, Leandro; Lanzarotti, Esteban; Luque, Javier; Barril, Xavier; Marti, Marcelo A.; Turjanski, Adrian G.

2014-01-01

228

Progress in Arabidopsis starch research and potential biotechnological applications.  

PubMed

For the past decade, Arabidopsis has been the model higher plant of choice. Research into leaf starch metabolism has demonstrated that Arabidopsis is a useful system in which to make fundamental discoveries about both starch biosynthesis and starch degradation. This review describes recent discoveries in these fields and illustrates how such discoveries might be applied in the green biotechnology sector to improve and diversify our starch crops. PMID:21185717

Santelia, Diana; Zeeman, Samuel C

2011-04-01

229

Resistant starch in the Italian diet.  

PubMed

Resistant starch (RS) has been defined as the sum of starch and starch-degradation products that reach the human large intestine (Champ, 1994), and it is now regarded as a sub-fraction of starch with a positive impact on colonic welfare and lipid metabolism. An early estimate of the RS intake in Europe gave an average value of approximately 4 g/d (Dyssler & Hoffem, 1994a). However, since no information is available for Italy, the aim of the present study was to estimate the intake of RS in the Italian diet by direct analysis of RS in a range of typical foods representing the main sources of starch intake in the country. The selection of representative foods and of food consumption data were based on published results of the National Food Consumption Study conducted during the 1980s by the National Institute of Nutrition on 10,000 households, using weighed-food records plus inventory methodologies (Saba et al. 1990; Turrini et al. 1991). Three main groups of foods were considered: cereals (pasta, rice, bread and bread products, and pastries), potatoes, legumes. Different commercial brands for each sample were purchased, according to the known presence on the market. Samples were prepared 'as eaten' and submitted to simulated chewing, followed by total and resistant starch determination using the enzymic procedure published as a result of the EC Concerted Action EURESTA (Champ, 1992). From these results, the estimated average intake of RS in Italy was found to be 8.5 g/d, with regional differences (from 7.2 g/d in the north-west to 9.2 g/d in the south) mainly due to the different consumption of some typical Italian starchy food (bread, pasta, legumes). PMID:9924275

Brighenti, F; Casiraghi, M C; Baggio, C

1998-10-01

230

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens  

Microsoft Academic Search

Summary  The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive.\\u000a \\u000a Potato tubers were exposed to 55C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated\\u000a seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of

E. P. Dashwood; E. M. Burnett; M. C. M. Perombelon

1991-01-01

231

Volatile organic compounds from a Tuber melanosporum fermentation system.  

PubMed

A total of 59 volatile organic compounds (VOCs) were identified from Tuber melanosporum fermentation: 53 from its fermented mycelia and 32 from the fermentation broth. Alcohol-derived compounds were predominant in both the fermentation mycelia and the broth, although long chain fatty acids and isoprenoids were, for the first time, also found in the mycelia. The intense wine bouquet properties of the broth arose from several specific flavor substances, including sulfur compounds, pyrazines, furans and jasmones. Comparing the VOCs identified in this work with those previously reported, our results are more similar to the composition of the Tuber fruiting-body than previous Tuber fermentations. The composition and accumulation of flavor volatiles (e.g., pyrazines, sulfur compounds, and esters) and major constituents (e.g., 3-methyl-1-butanol and 2-phenylethanol) in this fermentation were significantly influenced by the sucrose concentration in the medium. The obtained information could therefore be useful in applications to convert the flavors of truffle mycelia similar to those of the fruiting-body by optimising the fermentation process. PMID:22980851

Li, Yuan-Yuan; Wang, Guan; Li, Hong-Mei; Zhong, Jian-Jiang; Tang, Ya-Jie

2012-12-15

232

Generic Delimitations in Tuberous Periplocoideae (Apocynaceae) from Africa and Madagascar  

PubMed Central

• Background and Aims The number of genera included in Apocynaceae subfamily Periplocoideae is a matter of debate. DNA sequences are used here as an independent dataset to clarify generic relationships and classification of the tuberous periplocoid genera and to address the question of the phylogenetic interpretation of pollinia formation in Schlechterella. • Methods Representatives of nearly all African and Malagasy genera of Periplocoideae possessing root tubers were analysed using ITS and plastid DNA sequence characters. • Key Results Sequence data from non?coding molecular markers (ITS of nrDNA and the trnT?L and trnL?F spacers as well as the trnL intron of plastid DNA) give support for a broad taxonomic concept of Raphionacme including Pentagonanthus. Together with Schlechterella, which is sister to Raphionacme, all Raphionacme?like taxa form a derived monophyletic group of somewhat diverse species. Sister to the Schlechterella/Raphionacme clade is a clade comprising Stomatostemma and the not truly tuberous vine Mondia. In the combined analysis, sister to these two clades combined is a clade formed by Petopentia natalensis and Periploca. • Conclusions The recent inclusion of the monotypic South African Petopentia in the monotypic Malagasy endemic Ischnolepis is to be rejected. The Malagasy Camptocarpus is sister to the remainder of Periplocoideae in the ITS and combined analyses, and a Malagasy origin for the subfamily is discussed. PMID:14980976

MEVE, ULRICH; LIEDE, SIGRID

2004-01-01

233

Deformation mechanisms of plasticized starch materials.  

PubMed

The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch. PMID:25263913

Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P

2014-12-19

234

75 FR 879 - National Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers...  

Federal Register 2010, 2011, 2012, 2013

...Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers From Page Employment, Island Falls, ME; Amended Certification Regarding Eligibility To Apply for Worker Adjustment Assistance and Alternative Trade Adjustment...

2010-01-06

235

Content of starch and sugars and in vitro digestion of starch by alpha-amylase in five minor millets.  

PubMed

Five varieties of minor millets were studied for their amylose, soluble amylose, amylopectin, soluble amylopectin, reducing sugar, total sugar and starch contents. Pure starch was isolated from each variety and the enzymic degradation of starch by porcine pancreatic alpha-amylase were examined with and without gelatinisation. Gelatinised sample of Echinochloa frumentacea (var. K2) showed minimal hydrolysis and gelatinised sample of Panicum miliaceum (var. CO3) showed maximum hydrolysis of starch by porcine pancreatic alpha-amylase. Gelatinised starch was highly susceptible to enzymic digestion when compared to ungelatinised starch. The extent of starch degradation varied from 71 to 85 percent in gelatinised samples and starch degradation in ungelatinised sample varied from 10 to 18 percent. PMID:8882370

Krishnakumari, S; Thayumanavan, B

1995-12-01

236

Morphology and physicochemical properties of mechanically activated rice starch  

Microsoft Academic Search

The morphology and physicochemical properties of mechanically activated rice starch (MARS) isolated from three rice cultivars were investigated by scanning electron microscopy, X-ray diffractometry, gel permeation chromatography and Rapid Visco Analysis. The shape of rice starch granule changed from native polyhedron to anomalistic state during mechanical activation. It was suggested that the hydration of starch and moisture was an important

Zhengmao Zhang; Siming Zhao; Shanbai Xiong

2010-01-01

237

Starch metabolism in developing embryos of oilseed rape  

Microsoft Academic Search

.   The aim of this work was to characterise the metabolism of starch in developing embryos of oilseed rape (Brassica napus L. cv. Topaz). The accumulation of starch in embryos in siliques which were darkened or had been exposed to the light was\\u000a similar, suggesting that the starch is synthesised from imported sucrose rather than via photosynthesis in the embryo.

Paulo M. F. R. da Silva; Peter J. Eastmond; Lionel M. Hill; Alison M. Smith; Stephen Rawsthorne

1997-01-01

238

Original article Digestion of starch and glycaemic response  

E-print Network

and subsequent metabolic responses are due to two principal parameters: the suscepti- bility of starchOriginal article Digestion of starch and glycaemic response to mixed meals in pigs Lionel Noah 160 kJ) containing either native (NS) or pregelatinized (PS) maize starches (= 200 g

Paris-Sud XI, Université de

239

Acetylated starch-polylactic acid loose-fill packaging materials  

Microsoft Academic Search

Different genetic and botanical sources of starches are available for use in hydrophobic starch-based packaging materials. The objectives of this study were to evaluate the effects of the type of acetylated starch and the presence of polylactic acid (PLA) and ethanol on the functional properties of extruded foams, and to compare the specific mechanical energy requirements for preparing these foams.

Junjie Guan; Kent M. Eskridge; Milford A. Hanna

2005-01-01

240

Evidence for Distinct Mechanisms of Starch Granule Breakdown in Plants *  

E-print Network

The aim of this work was to understand the initial steps of starch breakdown inside chloroplasts. In the non-living endosperm of germinating cereal grains, starch breakdown is initiated by ?-amylase secreted from surrounding cells. However, loss of ?-amylase from Arabidopsis does not prevent chloroplastic starch breakdown (Yu,

Thierry Delatte; Martin Umhang; Martine Trevisan; Simona Eicke; David Thorneycroft; Steven M. Smith; Samuel C. Zeeman

241

Characteristics of Volatile Compounds of Starches Extracted with Aqueous Solutions  

Microsoft Academic Search

Volatile compounds of wheat, corn, and potato starches were determined prior to and upon extraction of the starches with aqueous solutions of sodium hydroxide (NaOH), ethanol, and sodium dodecyl sulfate (SDS). Aqueous NaOH extraction was effective in reducing the level of total volatiles and removing certain volatiles from both wheat and corn starches without increasing the level of hexanal, an

Abdulvahit Sayaslan

2006-01-01

242

Biodegradable packages development from starch based heat sealable films  

Microsoft Academic Search

Heat sealing capacity of native and acetylated corn starch based films was evaluated to develop biodegradable packages, such as bags. Thermo-mechanical properties were analyzed since they condition their handling and applications. Acetylated starch addition reinforced 80% sealing resistance of starch films. Unplasticized heat-sealed films presented adhesive failures while those containing glycerol showed a rupture near the zip. Unplasticized films exhibited

Olivia V. López; Carlos J. Lecot; Noemí E. Zaritzky; María A. García

2011-01-01

243

Characterization of rice starches extracted from Indian cultivars.  

PubMed

Physicochemical, morphological and pasting properties of starches isolated from four rice cultivars grown in India were studied. The amylose content ranged between 4.7 and 30.2% of starch, highest in K332 starch and lowest in SR1 starch. Swelling power, water solubility and water absorption capacity of starches increased with increase in temperature from 50 to 90?°C at 10?°C intervals. Highest swelling and water absorption was found in SR1 and lowest in K332 starches but reverse was observed in case of solubility that was highest for K332 and lowest for SR1 starch. The microstructure of starch granules from different rice cultivars showed the presence of mainly polyhedral granules having average size in the range of 4.0-5.2?µm. K332 showed the presence of smallest granules, whereas SR1 starch showed the presence of largest granules. X-ray diffraction pattern of rice starch from different cultivars showed typical A-type crystallinity. Pasting properties of starches differed significantly. Pasting temperature was highest for K332 and lowest for SR1, while peak viscosity was highest for aromatic rice and lowest for K448 starches. Higher setback was observed in K332 and lowest in SR1. PMID:23291829

Gani, Adil; Wani, S M; Masoodi, F A; Salim, Rehana

2013-04-01

244

Starch Damage in Soft Wheats of the Pacific Northwest  

Microsoft Academic Search

The effect of broad growing conditions in the Pacific Northwest and varietal differences on starch damage (191 samples) of soft white winter (SWW) and club wheat flours were investigated. Starch damage was measured enzymatically by the Megazyme method and iodometrically by a Chopin Rapid Flour Tester (RFT). The overall average of starch dam- age (cultivars, years, and locations) showed a

P.-Y. LIN; Z. CZUCHAJOWSKA

245

Size of tuber propagule influences injury of 'Kennebec' potato plants by constant light  

NASA Technical Reports Server (NTRS)

Chlorosis and necrotic spotting develop on the foliage of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light. 'Kennebec', a cultivar severely injured by constant light when propagated from tissue-cultured plantlets, also was injured when plants were propagated from small tuber pieces (approximately 1 g). However, plants did not develop injury when propagated from large tuber pieces (approximately 100 g). Plants from large tuber pieces grew more rapidly than plants from small tuber pieces. The role of plant vigor and carbohydrate translocation in controlling injury development is discussed.

Cushman, K. E.; Tibbitts, T. W.

1996-01-01

246

Effect of pre-planting temperature and light treatments of seed tubers on potato yield and tuber size distribution  

Microsoft Academic Search

Summary  From 1985 to 1987 field experiments were caried out to test the influence of different pre-planting storage treatments on\\u000a yield and size distribution of potato crops. The storage treatments included 4, 8 and 12C in the light and in the dark, for\\u000a different periods before planting. Subjecting the seed tubers to light at low temperatures induced crops to produce a

A. J. Haverkort; M. Van De Waart; K. B. A. Bodlaender

1990-01-01

247

Shelf-life extension of fresh Tuber aestivum and Tuber melanosporum truffles by modified atmosphere packaging with microperforated films.  

PubMed

The aim of this study was to design a modified atmosphere packaging suitable for Tuber melanosporum and Tuber aestivum truffles that extend their shelf life and their availability as a fresh product. Their respiration rates were determined by O(2) depletion and CO(2) formation in closed systems performed at different temperatures: 4, 10, and 23 degrees C. The results were fitted by exponential equations and derivatives of these equations were used to obtain the experimental respiration rates. Our results revealed high respiration rates in both species of truffles and respiratory quotients (RQ) higher than 1 in all the cases studied. A linear dependence of respiration rate, both R(O2) and R(CO2), on O(2) concentration was revealed. A mathematical model was used to predict the evolution of the gaseous composition at 4 degrees C in the interior of polypropylene trays (250 mL) heat sealed with 4 microperforated films of different transmission rates. A microperforated film with 2 holes (90 x 50 microm) was selected to produce an internal atmosphere of 15%CO(2)/7%O(2) at 4 degrees C. The predicted atmosphere composition was confirmed by the experimental results. The quality and microbiological characteristics of fresh truffles, packaged in these conditions, revealed that the microbial counts of pseudomonads and Enterobacteriaceae were decreased, the weight loss was reduced, the typical hard texture was maintained, and the development of mycelium growth was delayed, enabling good scores for aroma and flavor, and therefore prolonging the shelf life of T. melanosporum and T. aestivum truffles to 28 and 21 d, respectively. Practical Application: This study describes the benefits of using MAP with microperforated films in the postharvest storage of Tuber melanosporum and Tuber aestivum fresh truffles. The shelf life of T. aestivum is prolonged to 21 d and of T. melanosporum to beyond 28 d increasing the possibilities for a foreign market. PMID:20546403

Rivera, Carmen Susana; Blanco, Domingo; Salvador, María Luisa; Venturini, María Eugenia

2010-05-01

248

Seasonal adaptations of the tuberous roots of Ranunculus asiaticus to desiccation and resurrection by changes in cell structure and protein content.  

PubMed

The annual developmental cycle of tuberous roots of Ranunculus asiaticus was studied with respect to structure and content of their cells, to understand how these roots are adapted to desiccation, high temperature and rehydration. Light microscopy, histochemical analysis, and protein analyses by SDS-PAGE were employed at eight stages of annual root development. During growth and maturation of the roots, cortical cells increased in size and their cell walls accumulated pectin materials in a distinct layer to the inside of the primary walls, with pits between adjoining cells. The number of starch granules and protein bodies also increased within the cells. Several discrete proteins accumulated. Following quiescence and rehydration of the roots there was a loss of starch and proteins from the cells, and cell walls decreased in thickness. The resurrection geophyte R. asiaticus possesses desiccation-tolerant annual roots. They store carbon and nitrogen reserves within their cells, and pectin within the walls to support growth of the plant following summer quiescence and rehydration. PMID:15760363

Kamenetsky, Rina; Peterson, R Larry; Melville, Lewis H; Machado, Cibele F; Bewley, J Derek

2005-04-01

249

Genes coding for starch branching enzymes are major contributors to starch viscosity characteristics in waxy rice ( Oryza sativa L.)  

Microsoft Academic Search

Granule-bound starch synthase (GBSS) encoded by the Waxy (Wx) gene determines the synthesis of amylose; while, starch branching enzymes encoded by Sbe genes are involved in the formation of amylopectin. Both amylose and amylopectin form starch in the endosperm of seeds. Here, we report on the effects of the wx gene and the two Sbe genes, Sbe1 and Sbe3, on

Yuepeng Hana; Mingliang Xu; Xingyan Liu; Changjie Yan; Schuyler S. Korban; Xiulan Chen; Minghong Gua

250

Study on the properties of ethylenebisformamide plasticized corn starch (EPTPS) with various original water contents of corn starch  

Microsoft Academic Search

EPTPSs were prepared based on various original water contents of corn starch (10%, 13%, 16% and 19%). The structure and mechanical performance of resulting TPSs were studied in detail. The hydrogen bond between plasticizer and starch was detected by FT-IR. By scanning electron microscope (SEM), native corn starch granules were proved to transfer to a continuous phase. The crystallinity and

Jin-Hui Yang; Jiu-Gao Yu; Yan Feng; Xiao-Fei Ma

2007-01-01

251

PERCEIVING COLOR Visual Perception  

E-print Network

also on the response of the eye Multiplication of color spectrum with the luminous efficacy function X's Additive Color Wheel Three colors to create a reasonable subset Devices Even Eye Same color can be created1 PERCEIVING COLOR Visual Perception Slide 2 Aditi Majumder, UCI Functions of Color Vision Object

Majumder, Aditi

252

Effects of homoeologous wheat starch synthase IIa genes on starch properties.  

PubMed

Near-isogenic lines (NILs) of the eight haplotypes of starch synthase IIa (SSIIa) were used to analyze the effects of SSIIa gene dosage on branch chain length, gelatinization, pasting, retrogradation, and enzymatic hydrolysis of starches. Compared to wild-type, the amylopectin of lines missing one or more active SSIIa enzymes had increases in the proportion of short branch chains (DP6-10) and decreases in midlength chains (DP11-24), and the size of these differences depended on the dosage of active SSIIa enzymes. Of the three loci, SSIIa-A1 had the smallest contribution to amylopectin structure and SSIIa-B1 the largest. The different effects of the three SSIIa enzymes on starch properties were also seen in gelatinization, retrogradation, pasting, and enzymatic hydrolysis properties. Such differences in starch properties might be useful in influencing the texture and shelf life of food products. PMID:23136891

Shimbata, Tomoya; Ai, Yongfeng; Fujita, Masaya; Inokuma, Takayuki; Vrinten, Patricia; Sunohara, Ai; Saito, Mika; Takiya, Toshiyuki; Jane, Jay-lin; Nakamura, Toshiki

2012-12-01

253

Development and characterization of starch nanoparticles by gamma radiation: potential application as starch matrix filler.  

PubMed

Gamma radiation arises as an advantageous alternative to obtain starch nanoparticles given its low cost, simple methodology and scalability. Starch nanoparticles (SNP) with sizes around 20 and 30 nm were obtained applying a dose of 20 kGy from cassava (CNP-?) and waxy maize (WNP-?) starch, respectively. They showed the same thermal degradation behavior and their maximum mass loss zone was similar to those nanoparticles obtained from acid hydrolysis (WNP-h). Additionally, CNP-? and WNP-? were used as nanofillers in a cassava matrix. Increments of 102% in storage modulus were obtained with the addition of only 2.5 wt.% of WNP-?, showing that gamma radiation is a successful methodology to obtain SNP able to be used as starch reinforcement. PMID:23769521

Lamanna, Melisa; Morales, Noé J; García, Nancy Lis; Goyanes, Silvia

2013-08-14

254

Slowly Digestible Starch from Debranched Waxy Sorghum Starch: Preparation and Properties  

Microsoft Academic Search

Cereal Chem. 81(3):404-408 Effects of debranching time, storage time, and storage temperature on production and structural properties of slowly digestible starch (SDS) were investigated. Waxy sorghum starch was hydrolyzed by isoamylase for various times (0-24 hr), and the variously debranched products were stored at -30, 1, and 30°C for 1-6 days. Optimal conditions for SDS production were isoamylase treatment for

Sang Ick Shin; Hea Jin Choi; Koo Min Chung; Bruce R. Hamaker; Kwan Hwa Park; Tae Wha Moon

2004-01-01

255

Hidden Color  

NASA Astrophysics Data System (ADS)

With the acceptance of QCD as the fundamental theory of strong interactions, one of the basic problems in the analysis of nuclear phenomena became how to consistently account for the effects of the underlying quark/gluon structure of nucleons and nuclei. Besides providing more detailed understanding of conventional nuclear physics, QCD may also point to novel phenomena accessible by new or upgraded nuclear experimental facilities. We discuss a few interesting applications of QCD to nuclear physics with an emphasis on the hidden color degrees of freedom.

Ji, C.-R.

2014-10-01

256

Laser spectral analysis of starch products  

NASA Astrophysics Data System (ADS)

We have developed laser spectral analysis (LSA) methods for quality control of starch products in the raw material stage and after thermomechanical processing (extrusion). We show that it is possible to plot a common calibration curve for analyte elements in different types of analyte samples, i.e., we have established that there is no matrix effect on the analysis results.

Burakov, V. S.; Tarasenko, N. V.; Zhuravlova, V. I.; Kiris, V. V.; Litvjak, V. V.; Stepanenko, A. B.

2012-01-01

257

LOW WASTEWATER POTATO STARCH/PROTEIN PRODUCTION  

EPA Science Inventory

While potato starch has been an item of commerce for many years, traditional processing methods have incurred large volumes of high BOD effluents. The research summarized by this report has lead to a modified process which upgrades the soluble components formerly discarded in the...

258

Resistant Starch: Promise for Improving Human Health12  

PubMed Central

Ongoing research to develop digestion-resistant starch for human health promotion integrates the disciplines of starch chemistry, agronomy, analytical chemistry, food science, nutrition, pathology, and microbiology. The objectives of this research include identifying components of starch structure that confer digestion resistance, developing novel plants and starches, and modifying foods to incorporate these starches. Furthermore, recent and ongoing studies address the impact of digestion-resistant starches on the prevention and control of chronic human diseases, including diabetes, colon cancer, and obesity. This review provides a transdisciplinary overview of this field, including a description of types of resistant starches; factors in plants that affect digestion resistance; methods for starch analysis; challenges in developing food products with resistant starches; mammalian intestinal and gut bacterial metabolism; potential effects on gut microbiota; and impacts and mechanisms for the prevention and control of colon cancer, diabetes, and obesity. Although this has been an active area of research and considerable progress has been made, many questions regarding how to best use digestion-resistant starches in human diets for disease prevention must be answered before the full potential of resistant starches can be realized. PMID:24228189

Birt, Diane F.; Boylston, Terri; Hendrich, Suzanne; Jane, Jay-Lin; Hollis, James; Li, Li; McClelland, John; Moore, Samuel; Phillips, Gregory J.; Rowling, Matthew; Schalinske, Kevin; Scott, M. Paul; Whitley, Elizabeth M.

2013-01-01

259

Evaluation of a High Throughput Starch Analysis Optimised for Wood  

PubMed Central

Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11) was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood) of four species (coniferous and flowering plants). The optimised protocol proved to be remarkably precise and accurate (3%), suitable for a high throughput routine analysis (35 samples a day) of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes. PMID:24523863

Bellasio, Chandra; Fini, Alessio; Ferrini, Francesco

2014-01-01

260

Continuous enzymatic liquefaction of starch for saccharification  

SciTech Connect

A process was explored for continuous enzymatic liquefaction of corn starch at high concentration and subsequent saccharification to glucose. The process appears to be quite efficient for conversion of starch to glucose and enzymatic liquefaction and should be readily adaptable to industrial fermentation processes. Preliminary work indicated that milled corn or other cereal grains also can be suitably converted by such a process. Essentially, the process involved incorporation of a thermostable, bacterial alpha-amylase for liquefaction and, subsequently, of a glucoamylase into the continuous mixer under conditions conductive to rapid enzymatic hydrolyses. Also studied was the effect on substrate liquefaction of variables such as starch concentration (40-70%), level of alpha-amylase (0.14-0.4%, dry starch basis), temperature (70-100 degrees C), pH (5.8-7.1), and residence time (6 and 12 minutes). The degree of liquefaction was assessed by determining 1) the Brookfield viscosity, 2) the amount of reducing groups, and 3) the rate and extent of glucose formed after glucoamylase treatment. Best liquefaction processing conditions were achieved by using 50-60% starch concentration, at 95 degrees C, with 0.4% alpha-amylase, and a 6 minute residence period in the mixer. Under these conditions, rates and extents of glucose obtained after glucoamylase treatment approached those obtained in longer laboratory batch liquefactions. The amount of glucose formed in 24 hours with the use of 0.4% glucoamylase was 86% of theory after a 6-min continuous liquefaction, compared to 90% for a 30-min laboratory batch liquefaction (95 degrees C, 0.4% alpha-amylase). (Refs. 15).

Carr, M.E.; Black, L.T.; Bagby, M.O.

1982-01-01

261

Characterization of normal and waxy corn starch for bioethanol production.  

PubMed

Objectives of this study were to compare ethanol production between normal and waxy corn using a cold fermentation process and to understand effects of starch structures and properties on ethanol production. Ethanol yields positively correlated (p < 0.01) with starch contents of kernels of the normal and waxy corn. The average starch-ethanol conversion efficiency of waxy corn (93.0%) was substantially greater than that of normal corn (88.2%). Waxy corn starch consisted of very little amylose and mostly amylopectin that had a shorter average branch chain length than normal corn amylopectin. Regression analyses showed that average amylopectin branch chain lengths and percentage of long branch chains (DP > 37) of waxy corn starch negatively correlated with the starch hydrolysis rate and the ethanol yield. These results indicated that starch structures and properties of the normal and waxy corn had significant effects on the ethanol yield using a cold fermentation process. PMID:23241103

Yangcheng, Hanyu; Jiang, Hongxin; Blanco, Michael; Jane, Jay-lin

2013-01-16

262

deficient in a chloroplastic starch-hydrolysing enzyme  

E-print Network

The aim of this work was to identify enzymes that participate in the degradation of transitory starch in Arabidopsis. A mutant line was isolated by screening leaves at the end of the night for the presence of starch. The mutant had a higher starch content than the wild-type throughout the diurnal cycle. This accumulation was due to a reduction in starch breakdown, leading to an imbalance between the rates of synthesis and degradation. No reduction in the activity of endo-amylase (?-amylase), ?-amylase, starch phosphorylase, maltase, pullulanase or D-enzyme could be detected in crude extracts of leaves of the mutant. However, native PAGE in gels containing amylopectin revealed that a starch-hydrolysing activity, putatively identified as an endo-amylase and present in wild-type chloroplasts, was absent or appreciably reduced in the mutant. This is the first time that a specific enzyme required for starch degradation has been identified in leaves.

Samuel C. Zeeman; Fred Northrop; Alison M. Smith; Tom Ap Rees; John Innes Centre; Norfolk Nr Uh

263

Starch turnover: pathways, regulation and role in growth.  

PubMed

Many plants store part of their photosynthate as starch during the day and remobilise it to support metabolism and growth at night. Mutants unable to synthesize or degrade starch show strongly impaired growth except in long day conditions. In rapidly growing plants, starch turnover is regulated such that it is almost, but not completely, exhausted at dawn. There is increasing evidence that premature or incomplete exhaustion of starch turnover results in lower rates of plant growth. This review provides an update on the pathways for starch synthesis and degradation. We discuss recent advances in understanding how starch turnover and the use of carbon for growth is regulated during diurnal cycles, with special emphasis on the role of the biological clock. Much of the molecular and genetic research on starch turnover has been performed in the reference system Arabidopsis. This review considers to what extent information gained in this weed species maybe applicable to annual crops and perennial species. PMID:22541711

Stitt, Mark; Zeeman, Samuel C

2012-06-01

264

Some rheological properties of sodium caseinate-starch gels.  

PubMed

The influence of sodium caseinate on the thermal and rheological properties of starch gels at different concentrations and from different botanical sources was evaluated. In sodium caseinate-starch gels, for all starches with the exception of potato starch, the sodium caseinate promoted an increase in the storage modulus and in the viscosity of the composite gel when compared with starch gels. The addition of sodium caseinate resulted in an increase in the onset temperature, the gelatinization temperature, and the end temperature, and there was a significant interaction between starch and sodium caseinate for the onset temperature, the peak temperature, and the end temperature. Microscopy results suggested that sodium caseinate promoted an increase in the homogeneity in the matrix of cereal starch gels. PMID:15769164

Bertolini, Andrea C; Creamer, Lawrence K; Eppink, Mieke; Boland, Mike

2005-03-23

265

Effect of resistant starch on the cooking quality of yam (Dioscorea spp.) and cassava (Manihot esculenta) based paste products.  

PubMed

Total starch (TS) and resistant starch (RS) contents in pasty edible product of mealy and hard cooking tubers of three yam varieties and four cassava varieties were determined to evaluate their contribution in their cooking quality. TS and RS contents appeared as the main components in determining yam cooking quality. Mealy cooking yam varieties were characterized by a significant higher TS content (75.2 ± 7.7 g/100 g d.m.) and lower RS content (13.8 ± 3.4 g/100 g d.m.) than hard cooking yam varieties, which, in contrast, contained less TS (61.7 ± 12.1 g/100 g d.m.) and particularly high RS (21.8 ± 9.9 g/100 g d.m.), possibly as a consequence of the prevalence of large granules (35-40 ?m) observed by light microscope. Conversely, TS and RS contents appeared not determinant on the cooking quality of cassava. Moreover, higher amylose contents were associated with substantially elevated percentages of RS in yam and cassava, and high RS content in samples modulates their pasting properties by reducing the peak viscosity and the breakdown and requiring higher temperature and longer time to the peak. PMID:23215529

Kouadio, Olivier Kouadio; N'dri, Denis Yao; Nindjin, Charlemagne; Marti, Alessandra; Casiraghi, Maria Cristina; Faoro, Franco; Erba, Daniela; Bonfoh, Bassirou; Amani, N'guessan Georges

2013-06-01

266

Starch-Water Relationships in the Sugar-Snap Cookie Dough System  

Microsoft Academic Search

Cereal Chem. 75(5):660-664 Prime starch was extracted from soft and hard wheat flours and ball- milled to produce 100% damaged starch. Small amounts of the ball-milled starch or a pregelatinized starch were added to sugar-snap cookie formu- lations. Other cookie doughs were produced from prime starch only (no flour) with small amounts of the ball-m illed starch added. Starch damages

J. R. Donelson; C. S. Gaines

1998-01-01

267

Color Theory for Design  

NSDL National Science Digital Library

This lesson will introduce students to color theory with a focus on the use of color in digital design. Students will discover the color wheel, and color harmonies. Color is a very powerful tool in design. It can, enhance a message, give an object visual weight and emphasis, and add richness and depth to a design. We can use color to signify data, to draw attention to a particular object, or to set a mood. Color ...

Jensen, Mr.

2009-10-04

268

Learning About Color  

NSDL National Science Digital Library

In this project, students will learn about primary, secondary, and complementary colors. Students will also learn about warm & cool colors, along with tints & shades. Lastly, they will create an optical illusion using complimentary colors. INTRODUCTION: Welcome students! Begin by watching this fun video about colors. LEARNING ABOUT COLOR: Now, that you've had an introduction to colors, lets play a little game! Click on the link below. Carmine s Introduction to Color Awesome! Click on the links below ...

Erickson, Whitni

2009-04-18

269

The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development.  

PubMed

· Strigolactones (SLs) are a class of phytohormones controlling shoot branching. In potato (Solanum tuberosum), tubers develop from underground stolons, diageotropic stems which originate from basal stem nodes. As the degree of stolon branching influences the number and size distribution of tubers, it was considered timely to investigate the effects of SL production on potato development and tuber life cycle. · Transgenic potato plants were generated in which the CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) gene, key in the SL biosynthetic pathway, was silenced by RNA interference (RNAi). · The resulting CCD8-RNAi potato plants showed significantly more lateral and main branches than control plants, reduced stolon formation, together with a dwarfing phenotype and a lack of flowering in the most severely affected lines. New tubers were formed from sessile buds of the mother tubers. The apical buds of newly formed transgenic tubers grew out as shoots when exposed to light. In addition, we found that CCD8 transcript levels were rapidly downregulated in tuber buds by the application of sprout-inducing treatments. · These results suggest that SLs could have an effect, solely or in combination with other phytohormones, in the morphology of potato plants and also in controlling stolon development and maintaining tuber dormancy. PMID:23496288

Pasare, Stefania A; Ducreux, Laurence J M; Morris, Wayne L; Campbell, Raymond; Sharma, Sanjeev K; Roumeliotis, Efstathios; Kohlen, Wouter; van der Krol, Sander; Bramley, Peter M; Roberts, Alison G; Fraser, Paul D; Taylor, Mark A

2013-06-01

270

Pithiness and Growth of Radish Tubers as Affected by Irradiance and Plant Density  

Microsoft Academic Search

Pithiness in radish tubers (Raphanus sativusL.) is a syndrome where xylem parenchyma cells die and are filled with air. Features associated with rapid tuber growth such as large cells, great distances between strands of vascular tissue and rupture of xylem vessels have been suggested to induce pithiness. The objective of this study was to analyse the extent to which pithiness

L. F. M. MARCELIS; E. HEUVELINK; D. VAN DIJK

1997-01-01

271

Pithiness and Growth of Radish Tubers as Aected by Irradiance and Plant Density  

Microsoft Academic Search

Pithiness in radish tubers (Raphanus satiäus L.) is a syndrome where xylem parenchyma cells die and are filled with air. Features associated with rapid tuber growth such as large cells, great distances between strands of vascular tissue and rupture of xylem vessels have been suggested to induce pithiness. The objective of this study was to analyse the extent to which

L. F. M. MARCELIS; E. HEUVELINKãand; D. VAN

1997-01-01

272

Aquatic plant shows flexible avoidance by escape from tuber predation by swans  

Microsoft Academic Search

Deeper burial of bulbs and tubers has been suggested as an escape against below-ground herbivory by vertebrates, but experimental evidence is lacking. As deep propagule burial can incur high costs of emergence after dormancy, burial depth may represent a trade-off between sprouting survival and herbivore avoidance. We tested whether burial depth of subterraneous tubers is a flexible trait in fennel

B. Hidding; M. R. J. Klaassen; T. De Boer; P. P. De Vries; B. A. Nolet

2012-01-01

273

The influence of early soil moisture stress on tuber numbers in potato  

Microsoft Academic Search

The relationship between water shortage and tuber initiation and development in the cv. Maris Piper was examined in glasshouse experiments with several severities of water-stress induced by withholding water at different stages of plant growth. There was a direct reduction in tuber numbers per stem with increasing duration of water stress in plants deprived of water from the time when

D. K. L. MacKerron; R. A. Jefferies

1986-01-01

274

Ultrastructure of entry and spread of Erwinia carotovora var. atroseptica into potato tubers  

Microsoft Academic Search

Bacterial entry into potato tubers through wounds and lenticels was affected by the environment, especially by the prevailing relative humidity. Light and electron microscope examination of tubers inoculated withErwinia carotovora var.atroseptica under various environmental conditions showed that resistance to invasion was apparently due to the laying down of a barrier of suberin in the intercellular spaces and in two bands

R. T. V. Fox; J. G. Manners; A. Myers

1971-01-01

275

The Effect of Temperature and Daylength on the Germination of Potamogeton nodosus Tubers  

Microsoft Academic Search

The effects of temperature and daylength were studied in the germination of American pondweed (Potamogeton nodosus Poir.) tubers. Germination was examined at temperatures ranging from 5 to 30°C in conjunction with light treatments of short and long daylength and continuous darkness. Greatest percentage of tuber germination occurred between 15 and 20°C. Within this temperature range, daylength did not significantly affect

Nicole A. Flint; John D. Madsen

1995-01-01

276

Ethnobotanical Observation on Tuberous Plants from Tribal Area of Rajasthan (India)  

Microsoft Academic Search

The present paper gives an account of 42 tuberous plants of Ethnobotanical interest from Aravalli hills of Rajasthan. Main tribes inhabiting the study area are Bhil, Meena, Garasia, Damor and Kathodi. These tribes use the tuberous plants for various purposes in their daily life. Health, vitality and longevity enjoyed by the tribals have been attributed by them to these wild

Shweta Swarnkar; S. S. Katewa

2008-01-01

277

COLORS Magazine  

NSDL National Science Digital Library

COLORS Magazine was willed into existence in 1991 by photographer Oliviero Toscani and art director Tibor Kalman. Its goal was simple: "to show the world to the world.â The publication looks at social issues around the world through thoughtful prose and meaningful visuals. Visitors can click on the Stories tab to click through a visual field of photos that lead to such stories as military service in South Korea and cuts to public spending in the United Kingdom. The Notebooks area brings together commentaries from all over the world as part of a collaboration with Reporters sans Frontieres. The Projects area contains links to special issues and projects, such as the News Machine that "churns your tweets through different media filters.â Interested users can learn about obtaining a print subscription or explore the corresponding blog.

278

Disruptive Coloration  

NSDL National Science Digital Library

Most animals are patterned. While some markings may serve as an advertisement, many appear to function in concealment. Because of the principal way in which they seem to function, such markings are often termed disruptive coloration . Although there are a number of characteristics that may influence the effectiveness of markings in disruption; this study will only focus on two aspects: (1) the effectiveness of the position of markings in blurring or enhancing outline, and (2) the degree to which strongly contrasting markings may interfere with or aid recognition. In regard to the former, it must be kept in mind that the profile changes with change in viewing angle. Thus the pattern seen in relation to the profile most commonly presented to predator (or prey) is of most interest to us here.

Ipsen, David; Gillfillan, Gretchen L.; Judy Diamond (Revised New Edition); Judy Scotchmoor (Revised New Edition); Stebbins, Robert

2009-04-01

279

Physicochemical, functional, and macromolecular properties of waxy yam starches discovered from "Mapuey" (Dioscorea trifida) genotypes in the Venezuelan Amazon.  

PubMed

"Mapuey" tubers in Venezuela are staple food for indigenous peoples from the Caribbean coast and Amazon regions. Noticeable differences between genotypes of yam starches were observed. Granules were large, triangular, or shell-shaped with monomodal particle size distribution between 24.5 and 35.5 ?m. Differential scanning calorimetry (DSC) analyses revealed onset gelatinization temperatures from 69.1 to 73.4 °C with high gelatinization enthalpy changes from 22.4 to 25.3 J g(-1). All X-ray diffractograms of starches exhibit B-type crystallinity. Crystallinity degrees varied from 24% to 40%. The highest crystallinity was found for the genotype having the highest amylose content. Iodo-colorimetric, amperometric, and DSC amylose determinations varied from 1.4 to 8.7%, 2.2 to 5.9%, and 1.4 to 3.5% for Amazonian genotypes, in comparison with commercial Mapuey starches: 12.0, 9.5, and 8.7%, respectively. Solubility and swelling power at 90 °C varied from 2.1 to 4.4% and 20.5 to 37.0%, respectively. Gel clarity fluctuated from 22.4 to 79.2%, and high rapid visco analyzer (RVA) viscosity was developed at 5% starch suspension (between 1430 and 2250 cP). Amylopectin weight average molar mass M(w), radius of gyration R(G), hydrodynamic coefficient ?(G), and apparent molecular density d(Gapp) were determined using high-performance size exclusion chromatography (HPSEC) and asymmetrical flow field flow fractionation (A4F) techniques coupled with multiangle laser light scattering (MALLS) on the Dioscorea trifida genotypes exhibiting the lowest and highest amylose contents. Amylopectins showed very similar molecular conformations. M(w) values were 1.15 × 10(8) and 9.06 × 10(7) g mol(-1) using HPSEC and A4F, respectively, thus, 3-5 times lower than those reported with the same techniques for other yam species, and very close to those of potato and cassava amylopectins. This discovery of a new natural amylose-free starch in the neglected yam "Mapuey" could present some potential for the food industry. PMID:21158430

Pérez, Elevina; Gibert, Olivier; Rolland-Sabaté, Agnès; Jiménez, Yarlezka; Sánchez, Teresa; Giraldo, Andrés; Pontoire, Bruno; Guilois, Sophie; Lahon, Marie-Christine; Reynes, Max; Dufour, Dominique

2011-01-12

280

Inhibition of potato tuber sprouting: Low levels of cytosolic pyrophosphate lead to non-sprouting tubers harvested from transgenic potato plants  

Microsoft Academic Search

Summary  ExpressingE. coli inorganic pyrophosphatase in transgenic plants demonstrated that long distance sucrose transport is dependent on cytosolic\\u000a pyrophosphate. It was speculated that removal of cytosolic pyrophosphate would impair sucrose utilization during storage of\\u000a potato tubers and thereby prevent tuber sprouting. To explore this hypothesisSolanum tuberosum var. Dsire plants were transformed with a chimeric PPa gene. FollowingAgrobacterium mediated transformation, metabolite and

Mohamad Hajirezaei; Uwe Sonnewald

1999-01-01

281

Structure, morphology and functionality of acetylated and oxidised barley starches.  

PubMed

Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical-chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production. PMID:25172707

El Halal, Shanise Lisie Mello; Colussi, Rosana; Pinto, Vânia Zanella; Bartz, Josiane; Radunz, Marjana; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2015-02-01

282

Starch bioengineering affects cereal grain germination and seedling establishment.  

PubMed

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. PMID:24642850

Shaik, Shahnoor S; Carciofi, Massimiliano; Martens, Helle J; Hebelstrup, Kim H; Blennow, Andreas

2014-06-01

283

Structure of starch synthase I from barley: insight into regulatory mechanisms of starch synthase activity.  

PubMed

Starch, a polymer of glucose, is the major source of calories in the human diet. It has numerous industrial uses, including as a raw material for the production of first-generation bioethanol. Several classes of enzymes take part in starch biosynthesis, of which starch synthases (SSs) carry out chain elongation of both amylose and amylopectin. Plants have five classes of SS, each with different roles. The products of the reaction of SS are well known, but details of the reaction mechanism remain obscure and even less is known of how different SSs select different substrates for elongation, how they compete with each other and how their activities are regulated. Here, the first crystal structure of a soluble starch synthase is presented: that of starch synthase I (SSI) from barley refined to 2.7 Å resolution. The structure captures an open conformation of the enzyme with a surface-bound maltooligosaccharide and a disulfide bridge that precludes formation of the active site. The maltooligosaccharide-binding site is involved in substrate recognition, while the disulfide bridge is reflective of redox regulation of SSI. Activity measurements on several SSI mutants supporting these roles are also presented. PMID:23695246

Cuesta-Seijo, Jose A; Nielsen, Morten M; Marri, Lucia; Tanaka, Hidenori; Beeren, Sophie R; Palcic, Monica M

2013-06-01

284

Starch biosynthesis in rice endosperm requires the presence of either starch synthase I or IIIa.  

PubMed

Starch synthase (SS) I and IIIa are the first and second largest components of total soluble SS activity, respectively, in developing japonica rice (Oryza sativa L.) endosperm. To elucidate the distinct and overlapping functions of these enzymes, double mutants were created by crossing the ss1 null mutant with the ss3a null mutant. In the F(2) generation, two opaque seed types were found to have either the ss1ss1/SS3ass3a or the SS1ss1/ss3ass3a genotype. Phenotypic analyses revealed lower SS activity in the endosperm of these lines than in those of the parent mutant lines since these seeds had different copies of SSI and SSIIIa genes in a heterozygous state. The endosperm of the two types of opaque seeds contained the unique starch with modified fine structure, round-shaped starch granules, high amylose content, and specific physicochemical properties. The seed weight was ?90% of that of the wild type. The amount of granule-bound starch synthase I (GBSSI) and the activity of ADP-glucose pyrophosphorylase (AGPase) were higher than in the wild type and parent mutant lines. The double-recessive homozygous mutant prepared from both ss1 and ss3a null mutants was considered sterile, while the mutant produced by the leaky ss1 mutant×ss3a null mutant cross was fertile. This present study strongly suggests that at least SSI or SSIIIa is required for starch biosynthesis in rice endosperm. PMID:21730357

Fujita, Naoko; Satoh, Rui; Hayashi, Aki; Kodama, Momoko; Itoh, Rumiko; Aihara, Satomi; Nakamura, Yasunori

2011-10-01

285

Physicochemical Properties of Canna edulis Ker Starch on Heat-Moisture Treatment  

Microsoft Academic Search

Canna edulis Ker starch was modified by heat-moisture treatment at moisture levels ranging from 18 to 27 g\\/100 g starch and its physicochemical properties were investigated. Amylose content, swelling power, solubility as well as water and oil absorption capacity in native starch were higher than in all treated starches. However, alkaline water retention and acid susceptibility of native starch were

Juan Zhang; Zheng-Wu Wang; Jun-An Yang

2010-01-01

286

Physicochemical properties of common and waxy corn starches oxidized by different levels of sodium hypochlorite  

Microsoft Academic Search

Structure and physicochemical properties of oxidized common and waxy corn starches by different levels of sodium hypochlorite (0.25–3.0% active chlorine based on dry starch weight) were studied. The oxidized common corn starch generally had a higher carboxyl content but a similar carbonyl content compared with the oxidized waxy corn starch. The introduction of carboxyl and carbonyl groups promoted starch hydration

Ya-Jane Wang; Linfeng Wang

2003-01-01

287

Interactions between cationic starch and anionic surfactants  

Microsoft Academic Search

The surface tensions and the phase equilibria of dilute aqueous cationic starch (CS)\\/surfactant systems were investigated. The degree of substitution of the CS varied from 0.014 to 0.772. The surfactants investigated were sodium dodecyl sulphate (SDS), potassium octanoate (KOct), potassium dodecanoate (KDod) and sodium oleate (NaOl). The concentrations of CS were 0.001, 0.01 and 0.1 w%.

Juha Merta; Per Stenius

1995-01-01

288

Wastewater purification in the potato starch industry  

Microsoft Academic Search

Deproteinized and protein-containing wastewater from the potato starch industry was purified by anaerobic digestion followed by aerobic treatment. Inhibition of methanation by NH3 in concentrated deproteinized wastewater can be prevented by lowering the pH. SO32- was removed by reduction in an acidification-reactor. SO42- reduction was hydraulic retention time-dependent during acidification. Further elimination of SO42- can take place in the CH4

D. J. Wijbenga; J. B. M. Meiberg; K. Brunt

1984-01-01

289

Functional Properties of Extruded Starch Acetate Blends  

Microsoft Academic Search

Starch acetate, with degree of substitution of 2, was blended with 0, 7.5 and 15% polylactic acid (PLA), Eastar Bio Copolyester 14766 (EBC) or Mater-Bi ZF03U (MBI) and 10%, 13%, or 16% (d.b.) ethanol and twin-screw extruded at 160°C barrel temperature. Physical characteristics of the extrudates, such as radial expansion ratio, unit and bulk densities, and of the mechanical properties,

J. Guan; Q. Fang; M. A. Hanna

2004-01-01

290

Thermoplastic starch\\/natural rubber blends  

Microsoft Academic Search

Thermoplastic starch\\/natural rubber polymer blends were prepared using directly natural latex and cornstarch. The blends were prepared in an intensive batch mixer at 150°C, with natural rubber content varying from 2.5 to 20%. The blends were characterised by mechanical analysis (stress-strain) and by scanning electron microscopy. The results revealed a reduction in the modulus and in tensile strength, becoming the

A. J. F Carvalho; A. E Job; N Alves; A. A. S Curvelo; A Gandini

2003-01-01

291

Color Blindness Simulations  

MedlinePLUS

Color blindness Simulations Normal Color Vision Deuteranopia Color blindness marked by confusion of purplish red and green Tritanopia A dichromatism in ... and green and reduced sensitivity to monochromatic lights. Simulations created using Image J 1.22d, National Institutes ...

292

Soybean cotyledon starch metabolism is sensitive to altered gravity conditions  

NASA Technical Reports Server (NTRS)

We have demonstrated that etiolated soybean seedlings grown under the altered gravity conditions of clinorotation (1 rpm) and centrifugation (5xg) exhibit changes in starch metabolism. Cotyledon starch concentration was lower (-28%) in clinorotated plants and higher (+24%) in centrifuged plants than in vertical control plants. The activity of ADP-glucose pyrophosphorylase in the cotyledons was affected in a similar way, i.e. lower (-37%) in the clinorotated plants and higher (+22%) in the centrifuged plants. Other starch metabolic enzyme activities, starch synthase, starch phosphorylase and total hydrolase were not affected by the altered gravity treatments. We conclude that the observed changes in starch concentrations were primarily due to gravity-mediated differences in ADP-glucose pyrophosphorylase activity.

Brown, C. S.; Piastuch, W. C.; Knott, W. M.

1994-01-01

293

Soybean cotyledon starch metabolism is sensitive to altered gravity conditions  

NASA Astrophysics Data System (ADS)

We have demonstrated that etiolated soybean seedlings grown under the altered gravity conditions of clinorotation (1 rpm) and centrifugation (5xg) exhibit changes in starch metabolism. Cotyledon starch concentration was lower (-28%) in clinorotated plants and higher (+24%) in centrifuged plants than in vertical control plants. The activity of ADP-glucose pyrophosphorylase in the cotyledons was affected in a similar way, i.e. lower (-37%) in the clinorotated plants and higher (+22%) in the centrifuged plants. Other starch metabolic enzyme activities, starch synthase, starch phosphorylase and total hydrolase were not affected by the altered gravity treatments. We conclude that the observed changes in starch concentrations were primarily due to gravity-mediated differences in ADP-glucose pyrophosphorylase activity.

Brown, C. S.; Piastuch, W. C.; Knott, W. M.

1994-08-01

294

Development of highly-transparent protein/starch-based bioplastics.  

PubMed

Striving to achieve cost-competitive biomass-derived materials for the plastics industry, the incorporation of starch (corn and potato) to a base formulation of albumen and glycerol was considered. To study the effects of formulation and processing, albumen/starch-based bioplastics containing 0-30 wt.% starch were prepared by thermo-plastic and thermo-mechanical processing. Transmittance measurements, DSC, DMTA and tensile tests were performed on the resulting bioplastics. Optical and tensile properties were strongly affected by starch concentration. However, DMTA at low deformation proved to be insensitive to starch addition. Thermo-mechanical processing led to transparent albumen/starch materials with values of strength at low deformation comparable to commodity plastics. Consequently, albumen biopolymers may become a biodegradable alternative to oil-derived plastics for manufacturing transparent packaging and other plastic stuffs. PMID:19900806

Gonzalez-Gutierrez, J; Partal, P; Garcia-Morales, M; Gallegos, C

2010-03-01

295

Regulation of starch metabolism: the age of enlightenment?  

PubMed

Starch and sucrose are the primary products of photosynthesis in the leaves of most plants. Starch represents the major plant storage carbohydrate providing energy during the times of heterotrophic growth. Starch metabolism has been studied extensively, leading to a good knowledge of the numerous enzymes involved. In contrast, understanding of the regulation of starch metabolism is fragmentary. This review summarises briefly the known steps in starch metabolism, highlighting recent discoveries. We also focus on evidence for potential regulatory mechanisms of the enzymes involved. These mechanisms include allosteric regulation by metabolites, redox regulation, protein-protein interactions and reversible protein phosphorylation. Modern systems biology and bioinformatic approaches are uncovering evidence for extensive post-translational protein modifications that may underlie enzyme regulation and identify novel proteins which may be involved in starch metabolism. PMID:20171927

Kötting, Oliver; Kossmann, Jens; Zeeman, Samuel C; Lloyd, James R

2010-06-01

296

Structure characterization and hypoglycemic effects of dual modified resistant starch from indica rice starch.  

PubMed

Hypoglycemic effects of indica rice resistant starch (IR-RS) were investigated. We prepared IR-RS using a method that combined physical modification and enzyme modification, and the RS content was 47.0%. Differential scanning calorimetry--thermal gravimetric analysis showed that IR-RS have higher enthalpy and less loss of mass than single modified RS, heat-moisture RS and native starch. Scanning electron microscopy revealed that IR-RS displayed more compact spatial structure. IR-RS products displayed a mixture of B-and V-type x-ray diffraction patterns and the cyrstallinity was 51.0%. IR-RS significantly affected body weight, blood glucose, organ indices and serum lipid levels. These results demonstrated that dual modification changed the structure of indica rice starch and affected its digestibility as well as the blood glucose levels of the diabetic mice who consumed it. PMID:24528703

Zhou, Ying; Meng, Shaohua; Chen, Deyi; Zhu, Xiping; Yuan, Huaibo

2014-03-15

297

Variability in Starch Acetylation Efficiency from Commercial Waxy Corn Hybrids  

Microsoft Academic Search

Cereal Chem. 80(1):68-71 Raw material variability is common for starch processors and is responsible for increased processing costs. In this study, variability of starch acetylation due to hybrid influence was quantified. Six waxy corn (maize) hybrids from 1998 and five waxy corn hybrids from 1999 were wet-milled in the laboratory. Starch obtained from each hybrid was modified according to a

M. R. Wilkins; P. Wang; L. Xu; Y. Niu; M. E. Tumbleson; K. D. Rausch

2003-01-01

298

Cultivation of Mediterranean species of Tuber (Tuberaceae) in British Columbia, Canada.  

PubMed

Based on an assessment of soil and climatic conditions in British Columbia (BC), the Truffle Association of British Columbia (TABC) determined that the cultivation of Mediterranean Tuber melanosporum and Tuber aestivum might be possible in the warmer parts of the province. With the cooperation of independent truffle growers, TABC assessed the colonization of host tree roots collected from eight truffle orchards planted 2-7 years earlier using morphological and molecular criteria. Both Tuber species persisted on the roots of inoculated trees in six of the eight truffle orchards studied. The identity of Tuber ectomycorrhizas that had been characterized morphologically as differing from those of T. melanosporum and T. aestivum were determined using DNA sequence analysis to belong to three species of truffles native to the Pacific Northwest. One of those species, Tuber anniae, had been previously reported from BC, but the other two, Tuber menseri nom. prov. and Tuber beyerlei, are reported here from BC for the first time. Recently, production of three Périgord black truffles in one truffle orchard and one Burgundy truffle in another orchard demonstrates that these truffles are able to fruit in BC. PMID:24496857

Berch, Shannon M; Bonito, Gregory

2014-08-01

299

Novel polymer blends with thermoplastic starch  

NASA Astrophysics Data System (ADS)

A new class of polymers known as "bioplastics" has emerged and is expanding rapidly. This class consists of polymers that are either bio-based or biodegradable, or both. Among these, polysaccharides, namely starch, are of great interest for several reasons. By gelatinizing starch via plasticizers, it can be processed in the same way as thermoplastic polymers with conventional processing equipment. Hence, these bio-based and biodegradable plastics, with their low source and refinery costs, as well as relatively easy processability, have made them ideal candidates for incorporation into various current plastic products. Four different plasticizers have been chosen here for gelatinization of thermoplastic starch (TPS): glycerol, sorbitol, diglycerol and polyglycerol, with the latter two being used for the first time in such a process. Two methodological categories are used. The first involves a calorimetric method (Differential Scanning Calorimetry) as well as optical microscopy; these are "static" methods where no shear is applied A wide range of starch/water/plasticizer compositions were prepared to explore the gelatinization regime for each plasticizer. The onset and conclusion gelatinization temperatures for sorbitol and glycerol were found to be in the same vicinity, while diglycerol and polyglycerol showed significantly higher transition temperatures. The higher molecular weight and viscosity of polyglycerol allow this transition to occur at an even higher temperature than with diglycerol. This is due to the increase in molecular weight and viscosity of the two new plasticizers, as well as their significant decrease in water solubility. It is demonstrated that the water/plasticizer ratio has a pronounced effect on gelatinization temperatures. When plasticizer content was held constant and water content was increased, it was found that the gelatinization temperature decreased for all the plasticizers. Meanwhile, when the water content was held constant and the plasticizer content was increased, the gelatinization temperature increased for glycerol, sorbitol and diglycerol, but it moved in the opposite direction in the case of polyglycerol. The gelatinization temperature variation for glycerol, sorbitol and diglycerol caused by changing water and plasticizer content indicates that water is the primary agent causing granular swell and plasticization in the gelatinization process. Due to the high molecular weight and viscosity, as well as the low hydroxyl group density (~ one --OH per two carbon) and borderline solubility of polyglycerol in water, it is believed that water-aided penetration of the plasticizer among the crystalline structure of starch molecules is significantly decelerated. So it is proposed that in the case of low-water solubility of the plasticizers, gelatinization temperature is determined more by the total amount of the plasticizer and water, rather than the water/plasticizer ratio. Increasing the miscibility of polyglycerol in water by increasing the temperature of the initial slurry, results in a return of the system to the typical thermal dependence of gelatinization with plasticizer/water ratio. Secondly, the gelatinization of starch under "dynamic conditions" was studied. In this case, a constant shear is applied to the slurry, along with a temperature ramp to induce gelatinization. This is, in fact, a rheological technique that heats up the slurry, while a mechanical shear is applied throughout. The reason for using this method is that in the plastic industry, thermoplastic starch is produced via processes involving shear such as extrusion, but, to date, there has not yet been a thorough study on the effect of pure shear on the gelatinization process. Glycerol, diglycerol and sorbitol were subjected to different dynamic gelatinization treatments in a couette flow system, and the results were compared with static gelatinization. Applying shear showed virtually no effect on the onset gelatinization temperature. However, the conclusion temperature was remarkably reduced

Taghizadeh, Ata

300

Available starch pools in mature soybean leaves. [Glycine max  

SciTech Connect

Soybeans, Glycine max, were grown in the greenhouse and in the field under conditions that varied CO/sub 2/ levels, irradiance, and photosynthetic period. Photosynthesis, sucrose export rate, starch accumulation, and starch mobilization were measured in mature leaves and compared to expansion of developing leaves two nodes above. Measurements were made daily over a twelve day period. Measured parameters in mature leaves varied daily with night expansion of the growing leaves. Starch accumulation and photosynthesis were affected by the environmental factors while sucrose export rate and starch mobilization were affected only if growth of the expanding leaves changed. The data indicated that influence of night expansion of developing leaves and influence of the environmental factors on photosynthesis caused two pools of starch to be formed in mature leaves. Concentration of each starch pool was calculated. The pool associated with night growth of expanding leaves was positively correlated with photosynthesis and sucrose export rate. The other pool, a storage, was negatively correlated with these parameters. Starch mobilization was comprised of starch from either pool, depending on the plant's environment or it was comprised of starch from both pools.

Highsmith, M.

1987-04-01

301

Diversity of culturable microorganisms and occurrence of Listeria monocytogenes and Salmonella spp. in Tuber aestivum and Tuber melanosporum ascocarps.  

PubMed

The aim of this study was to investigate the total mesophilic microorganisms, Pseudomonas genus, Enterobacteriaceae family, mold and yeast counts and the presence of Listeria monocytogenes and Salmonella spp on Tuber aestivum and Tuber melanosporum ascocarps. The results confirmed that the major percentage of the microorganisms, approximately 9.0 log ufc/g, were present in the peridium, the glebas of healthy truffles being practically free of microorganisms. The predominant microbial group was the Pseudomonas averaging 8.3 and 8.4 log cfu/g on T. aestivum and T. melanosporum whole ascocarps, respectively. The Enterobacteriaceae also achieved high populations, especially in T. aestivum truffles, with 6.3 log cfu/g. Molds and yeasts never exceeded 5.0 log cfu/g. The characterization of the isolates revealed that the fluorescens pseudomonads were the most prevalent. Raoultella terrigena and Enterobacter intermedius were the dominant Enterobacteriaceae. The identification of the yeast isolates revealed five species: Debaryomyces hansenii, Issatchenkia scutulata, Rhodotorula aurantiaca, Saccharomyces dairensis and Trichosporon beigelii subspecies A and B. The mold genera detected in both species of truffles were Aspergillus, Cladosporium, Penicillium and Fusarium, Trichoderma being present only in T. aestivum. L. monocytogenes was found in 10% of the samples of T. aestivum analysed but Salmonella spp. was not detected. Knowledge of the microbial population in terms of possible food borne and pathogen microorganisms is very useful for establishing successful disinfection and storage methods to prolong the shelf-life of ascocarps of T. aestivum and T. melanosporum. PMID:20141948

Rivera, Carmen Susana; Blanco, Domingo; Oria, Rosa; Venturini, María Eugenia

2010-04-01

302

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2014-07-01

303

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2013-07-01

304

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2010-07-01

305

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2012-07-01

306

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2011-07-01

307

77 FR 43601 - Risks and Benefits of Hydroxyethyl Starch Solutions; Public Workshop  

Federal Register 2010, 2011, 2012, 2013

...Risks and Benefits of Hydroxyethyl Starch Solutions; Public Workshop AGENCY: Food and Drug...Risks and Benefits of Hydroxyethyl Starch Solutions.'' The purpose of this public workshop...FDA-approved hydroxyethyl starch (HES) solutions. The public workshop has been...

2012-07-25

308

Inhibition of buckwheat starch digestion by the formation of starch/bile salt complexes: possibility of its occurrence in the intestine.  

PubMed

During the digestion of starch in foods, starch is mixed with bile in the duodenum. Because fatty acids and some kinds of polyphenols could bind to starch, it was postulated that bile salts might also bind to starch. The purpose of this paper is to study the effects of bile and bile salts on starch/iodine complex formation and pancreatin-induced starch digestion. Bile suppressed starch/iodine complex formation and inhibited pancreatin-induced starch digestion slightly in control buckwheat starch, but did so significantly in buckwheat starch from which fatty acids and polyphenols had been extracted. Such significant suppression and inhibition by bile were also observed in a reagent soluble starch. The effects of cholate and taurocholate on the starch/iodine complex formation and the pancreatin-induced starch digestion were essentially the same as those of bile. Bile, cholate, and taurocholate suppressed amylose/iodine complex formation more significantly than amylopectin/iodine complex formation and inhibited pancreatin-induced amylose digestion more effectively than the digestion of amylopectin. It is concluded from the results that bile salts could bind to starch, especially amylose, the helical structures of which were not occupied by other molecules such as fatty acids and polyphenols, and that the binding resulted in the inhibition of starch digestion by pancreatin. The conclusion suggests that the function of bile salts can be discussed from the point of not only lipid digestion but also starch digestion. PMID:21528929

Takahama, Umeo; Hirota, Sachiko

2011-06-01

309

Microsatellites, single nucleotide polymorphisms and a sequence tagged site in starch-synthesizing genes in relation to starch physicochemical properties in nonwaxy rice ( Oryza sativa L.)  

Microsoft Academic Search

Starch characteristics determine the quality of various products of rice, e.g., eating, cooking and processing qualities. Our previous study indicated that molecular markers inside or close to starch synthesizing genes can differentiate the starch properties of 56 waxy rices. Here we report microsatellite (or simple sequence repeat, SSR) polymorphism in the Waxy (Wx) gene, soluble starch synthase I gene (SS1)

J. S. Bao; H. Corke; M. Sun

2006-01-01

310

Inhibition of the expression of the starch synthase II gene leads to lower pasting temperature in sweetpotato starch  

Microsoft Academic Search

The sweetpotato cultivar Quick Sweet (QS) with a lower pasting temperature of starch is a unique breeding material, but the\\u000a biochemical background of this property has been unknown. To assess the physiological impact of the reduced isoform II activity\\u000a of starch synthase (SSII) on the starch properties in sweetpotato storage root, transgenic sweetpotato plants with reduced expressions of the SSII

Yasuhiro Takahata; Masaru Tanaka; Motoyasu Otani; Kenji Katayama; Kanefumi Kitahara; Osamu Nakayachi; Hiroki Nakayama; Masaru Yoshinaga

2010-01-01

311

Tuberous Sclerosis and Cardiac Tumors: New Electrocardiographic Finding in an Infant  

PubMed Central

Cardiac rhabdomyoma, the primary cardiac tumor most often diagnosed in children, is frequently present in patients with tuberous sclerosis. Most pediatric patients with rhabdomyoma are asymptomatic; however, various electrocardiographic abnormalities can be detected, such as Wolff-Parkinson-White syndrome, ectopic atrial tachycardia, and atrioventricular node dysfunction. We describe the case of a 10-month-old infant girl who had tuberous sclerosis and multiple cardiac rhabdomyomas. Her electrocardiographic presentation was notable for dome-shaped T waves and no ST segment in some leads. To our knowledge, this electrocardiographic finding has not been described in patients with tuberous sclerosis and cardiac masses. PMID:25425989

Sap, Fatih; Sert, Ahmet; Odabas, Dursun

2014-01-01

312

[Effect of jasmonic acid on Ca+2 transport through the plasmalemma of potato tuber cells].  

PubMed

The rate of Ca2+ accumulation in plasmalemma vesicles isolated from quiescent and sprouting potato (Solanum tuberosum L.) tubers and the effect of 10(-5) - 10(-10) M jasmonic acid on the accumulation of Ca+2 in plasmalemma vesicles and its efflux were studied. It was found that potato tuber plasmalemma contains a Ca+2, Mg+2-ATPase whose activity decreases upon the transition from forced quiescence to growth. The direction of the effect ofjasmonic acid on Ca+2, Mg+2-ATPase (stimulation or suppression) depends on the physiological state of tubers and the phytohormone concentration. PMID:19145980

Ladyzhenskaia, E P; Korableva, N P

2008-01-01

313

Rare association of Turner syndrome with neurofibromatosis type 1 and tuberous sclerosis complex  

PubMed Central

We report a rare association of Turner syndrome with both Neurofibromatosis type I and Tuberous Sclerosis. The patient had XOkaryotype with Turners stigmata and also had features of Neurofibromatosis 1 in the form of significant café-au-lait spots and Plexiform neurofibroma along with typical features of Tuberous Sclerosis complex. Pedigree analysis revealed that the elder brother of the proband in the family also suffered from Tuberous Sclerosis without the manifestation of Neurofibromatosis or any other genetic disorders. We hypothesize that these associations could be due to new independent mutations and also increased maternal and paternal age in a pre-disposition of Turner syndrome. PMID:20680156

Suttur, Malini S.; Mysore, Savitha R.; Krishnamurthy, Balasundaram; Nallur, Ramachandra B.

2009-01-01

314

Uniform color space based on color matching  

NASA Astrophysics Data System (ADS)

This research intends to explore with a uniform color space based on the CIE 1931 x-y chromatic coordinate system. The goal is to improve the non-uniformity of the CIE 1931 x-y chromaticity diagram such as to approach the human color sensation as possible; however, its simple methodology still can be kept. In spite of the existence of various kinds of the uniform color coordinate systems built up early (CIE u'-v', CIE Lab, CIE LUV, etc.), the establishment of a genuine uniform color space is actually still an important work both for the basic research in color science and the practical applications of colorimetry, especially for recent growing request in illumination engineering and in display technology. In this study, the MacAdam ellipses and the Munsell color chips are utilized for the comparison with the human color sensation. One specific linear transformation matrix is found for the CIE 1931 color matching functions (see manuscript) to become the novel uniform ones. With the aid of the optimization method, the transformation matrix can be easily discovered and makes the 25 MacAdam ellipses are similar to each other in the novel uniform color space. On the other hand, the perfectiveness of the equal-hue curves and the equal-chroma contours from the Mnusell color chips evaluates for the best optimization conditions among several different definitions for the similarity of all the MacAdam ellipses. Finally, the color difference between any two colors can be simply measured by the Euclidean distance in the novel uniform color space and is still fitted to the human color sensation.

Liao, Shih-Fang; Yang, Tsung-Hsun; Lee, Cheng-Chung

2007-09-01

315

Organisation of the external region of the starch granule as determined by infrared spectroscopy  

Microsoft Academic Search

Attenuated total reflectance–Fourier transform infrared (ATR–FTIR) was used to study the external regions of starch granules. Native starches (wheat, potato, maize, waxy maize and amylomaize) were analysed and compared to gelatinised and acid-hydrolysed starches. The IR spectra of potato and amylomaize starches were closer to that of highly ordered acid-hydrolysed starch than the other starches. FTIR was not able to

O Sevenou; S. E Hill; I. A Farhat; J. R Mitchell

2002-01-01

316

Multigene engineering of starch biosynthesis in maize endosperm increases the total starch content and the proportion of amylose.  

PubMed

Maize (Zea mays spp. mays) is a staple crop for more than 900 million people. The seeds or kernels provide a rich source of calories because ~70% of the weight is carbohydrate, mostly in the form of starch. The content and composition of starch are complex traits controlled by many genes, offering multiple potential targets for intervention. We used a multigene engineering approach combining the overexpression of Bt2, Sh2, Sh1 and GbssIIa (to enhance the activity of sucrose synthase, AGPase and granule-bound starch synthase) with the suppression of SbeI and SbeIIb by RNA interference (to reduce the activity of starch branching enzyme). Maize plants expressing all six genes plus the selectable marker showed a 2.8-7.7% increase in the endosperm starch content and a 37.8-43.7% increase in the proportion of amylose, which was significant compared to untransformed control plants. We also observed improvements in other agronomic traits, such as a 20.1-34.7% increase in 100-grain weight, a 13.9-19.0% increase in ear weight, and larger kernels with a better appearance, presumably reflecting the modified starch structure within the kernels. Our results confirm that multigene engineering applied to the starch biosynthesis pathway can not only modulate the quality and quantity of starch but can also improve starch-dependent agronomic traits. PMID:23740205

Jiang, Lili; Yu, Xiaoming; Qi, Xin; Yu, Qian; Deng, Sen; Bai, Bing; Li, Ning; Zhang, Ai; Zhu, Changfu; Liu, Bao; Pang, Jinsong

2013-12-01

317

Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion.  

PubMed

Arabidopsis thaliana mutants lacking the SS4 isoform of starch synthase have strongly reduced numbers of starch granules per chloroplast, suggesting that SS4 is necessary for the normal generation of starch granules. To establish whether it plays a direct role in this process, we investigated the circumstances in which granules are formed in ss4 mutants. Starch granule numbers and distribution and the accumulation of starch synthase substrates and products were investigated during ss4 leaf development, and in ss4 mutants carrying mutations or transgenes that affect starch turnover or chloroplast volume. We found that immature ss4 leaves have no starch granules, but accumulate high concentrations of the starch synthase substrate ADPglucose. Granule numbers are partially restored by elevating the capacity for glucan synthesis (via expression of bacterial glycogen synthase) or by increasing the volumes of individual chloroplasts (via introduction of arc mutations). However, these granules are abnormal in distribution, size and shape. SS4 is an essential component of a mechanism that coordinates granule formation with chloroplast division during leaf expansion and determines the abundance and the flattened, discoid shape of leaf starch granules. PMID:23952675

Crumpton-Taylor, Matilda; Pike, Marilyn; Lu, Kuan-Jen; Hylton, Christopher M; Feil, Regina; Eicke, Simona; Lunn, John E; Zeeman, Samuel C; Smith, Alison M

2013-12-01

318

New Starch Phenotypes Produced by TILLING in Barley.  

PubMed

Barley grain starch is formed by amylose and amylopectin in a 1?3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications. PMID:25271438

Sparla, Francesca; Falini, Giuseppe; Botticella, Ermelinda; Pirone, Claudia; Talamè, Valentina; Bovina, Riccardo; Salvi, Silvio; Tuberosa, Roberto; Sestili, Francesco; Trost, Paolo

2014-01-01

319

The deposition and characterization of starch in Brachypodium distachyon.  

PubMed

Brachypodium distachyon is a non-domesticated cereal. Nonetheless, Brachypodium was recently introduced as a model plant for temperate cereals. This study compares grain starch metabolism in Brachypodium and barley (Hordeum vulgare). In Brachypodium, we identified and annotated 28 genes involved in starch metabolism and identified important motifs including transit peptides and putative carbohydrate-binding modules (CBMs) of the families CBM20, CBM45, CBM48, and CBM53. Starch content was markedly lower in Brachypodium grains (12%) compared to barley grains (47%). Brachypodium starch granules were doughnut shaped and bimodally distributed into distinct small B-type (2.5-10 µm) and very small C-type (0.5-2.5 µm) granules. Large A-type granules, typical of cereals, were absent. Starch-bound phosphate, important for starch degradation, was 2-fold lower in Brachypodium compared with barley indicating different requirements for starch mobilization. The amylopectin branch profiles were similar and the amylose content was only slightly higher compared with barley cv. Golden Promise. The crystallinity of Brachypodium starch granules was low (10%) compared to barley (20%) as determined by wide-angle X-ray scattering (WAXS) and molecular disorder was confirmed by differential scanning calorimetry (DSC). The expression profiles in grain for most genes were distinctly different for Brachypodium compared to barley, typically showing earlier decline during the course of development, which can explain the low starch content and differences in starch molecular structure and granule characteristics. High transitory starch levels were observed in leaves of Brachypodium (2.8% after 14h of light) compared to barley (1.9% after 14h of light). The data suggest important pre-domesticated features of cereals. PMID:25056772

Tanackovic, Vanja; Svensson, Jan T; Jensen, Susanne L; Buléon, Alain; Blennow, Andreas

2014-10-01

320

New Starch Phenotypes Produced by TILLING in Barley  

PubMed Central

Barley grain starch is formed by amylose and amylopectin in a 1?3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications. PMID:25271438

Sparla, Francesca; Falini, Giuseppe; Botticella, Ermelinda; Pirone, Claudia; Talame, Valentina; Bovina, Riccardo; Salvi, Silvio; Tuberosa, Roberto; Sestili, Francesco; Trost, Paolo

2014-01-01

321

Color Me Understood.  

ERIC Educational Resources Information Center

Describes the "color system" as a way of grouping children into different personality types based on a certain color: orange, blue, green, and gold. Lists stress producers for specific color people. Asserts that, through making groups of different colors, children begin to see the various specialties others can bring to the group and learn to…

Harris, Judy J.

2000-01-01

322

Color Transfer between Images  

Microsoft Academic Search

Often this means removing a dominant and undesirable color cast, such as the yellow in photos taken under incandescent illumination. This article describes a method for a more general form of color correction that borrows one image's color characteristics from anoth-er. Figure 1 shows an example of this process, where we applied the colors of a sunset photograph to a

Erik Reinhard; Michael Ashikhmin; Bruce Gooch; Peter Shirley

2001-01-01

323

The starch granule associated proteomes of commercially purified starch reference materials from rice and maize  

Microsoft Academic Search

Commercially available reference materials are integral components of many experimental protocols, as it is critical to compare one's results to those derived from well-characterized standards. Most reference materials are well defined, with all their components being cataloged. However, certain reference materials, such as commercially prepared starch samples, can have undefined components, potentially limiting their usefulness as standards. The proteome of

Adam G. Koziol; Benazir K. Marquez; Matthew P. Huebsch; Jeffrey C. Smith; Illimar Altosaar

324

New data on ectomycorrhizae and soils of the Chinese truffles Tuber pseudoexcavatum and Tuber indicum, and their impact on truffle cultivation.  

PubMed

Chinese truffles serve as a good complement to the market for Tuber melanosporum (Périgord black truffle). However, Chinese truffles could be introduced accidentally or fraudulently into the plantations of Mediterranean truffles, and they could have a negative effect on truffle production and natural ecosystems. The study of Tuber species from China which are commercialized in Europe began 14 years ago. Tuber pseudoexcavatum was proposed as a new species, and this has been validated by some authors based on molecular and phylogenetic studies. We synthesize their ectomycorrhizae using samples from the type collection, and we compare T. pseudoexcavatum and Tuber indicum ectomycorrhizae. The ectomycorrhizae of these species have a morphology which is related to the ectomycorrhizae of T. melanosporum. We provide useful information for the rapid screening of the above-mentioned Chinese truffles ectomycorrhizae, for the quality control of commercial plants mycorrhized with Tuber. Moreover, we analyze the soil tolerance and the host plant affinity of T. pseudoexcavatum and T. indicum, in order to assess the capacity of both Chinese truffles to penetrate T. melanosporum plantations and habitats. PMID:18813959

García-Montero, Luis G; Di Massimo, Gabriella; Manjón, José L; García-Abril, Antonio

2008-12-01

325

The lungs in lymphangiomyomatosis and in tuberous sclerosis.  

PubMed Central

Two cases of pulmonary lymphangiomyomatosis (PL) are described and 33 other cases from the literature are reviewed. These are compared with one case of tuberous sclerosis with pulmonary involvement (PTS) and 32 other cases from the literature. There are no differences in lung function between these two conditions, both of which show airways obstruction associated with diffuse radiological lung changes. There are, however, both clinical and radiological differences and also differences in the distribution of the lesions and the histological location of the excessive smooth muscle; these indicate that PL and PTS are probably different entities and not polar forms of one condition. Finally, the strictly female incidence of PL suggests a sex-linked disorder, and it is postulated that this may be related to congenital pulmonary lymphangiectases. Images PMID:1198388

Stovin, P G; Lum, L C; Flower, C D; Darke, C S; Beeley, M

1975-01-01

326

Precocious puberty produced by an osteolipoma of the tuber cinereum.  

PubMed

Central precocious puberty (CPP) is fairly common in girls. In most girls, the etiology for the CPP is unknown. Among the more rare causes of CPP in girls are central nervous system tumors and hamartomas. Osteolipoma of the tuber cinereum, which is the most commonly diagnosed at autopsy, has been reported as a cause of CPP. We describe an 8-year-old girl with central precocious puberty in whom MRI demonstrated a lesion compatible with osteolipoma. Her symptom was breast development that begun at age 7 years and 9 months. Her case history, laboratory studies and imaging are presented. Her puberty was rapidly progressive. She was treated successfully with a GnRHa (Triptorelin 3.75 mg IM q 4 weeks). Her case brings to the forefront the need to perform an MRI in children with rapidly progressing puberty. PMID:23329765

Vivanco-Allende, Ana; García-González, Mónica; González-Jiménez, David; Pérez-Guirado, Alejandro; Fernández, Isela; Gómez-Illan, Rafael

2012-01-01

327

RGB Additive Color  

NSDL National Science Digital Library

Color is all around us. RGB is the color system that is used when mixing light. The RGB system is what we use in computers, televisions, stage lighting, displays and more. It is also called the additive color system because the colors are combined or added to each other to make the colors that we see. What wavelength goes with a color? Remember that a a nanometer is a unit of length in the metric system equal to one billionth of a meter. NASA What is a wave? NASA Color Why is the sky blue? What is RGB and how and where is it used? RGB World 21st Century Color Theory RGB colors are identified on computers by a color value that ranges for R, G, and B, ...

Engelman, Mr.

2010-12-05

328

Correction of tuberous breasts using the unfolded subareolar gland flap.  

PubMed

In this retrospective study, the authors present 12 years of experience using a modified Puckett's technique with a double unfolded strictly subareolar glandular flap for surgical correction of the deformity known as "tuberous breast." In 1976, Rees and Aston documented this congenital malformation of the mammary glands in women. Its cause is unknown, and it affects adolescent girls with varying severity uni- or bilaterally. The condition is characterized by a lack of development, primarily in the lower quadrants of the breast plus a rising of the inframammary fold, together with herniation and increased diameter of the areola. Many varied surgical techniques for correction of this malformation in its different degrees of severity have been documented in the available literature. This study examined the treatment of 42 breasts in 26 patients with a high percentage of full correction of the deformity. The advantages and achievements of the double unfolded strictly subareolar glandular flap include restructuring of the breast's lower pole in volume, length, and shape; reduction and even removal of the double-bubble effect as the flap covers the implant fitted; lowering of inframammary fold height; and correction of areola size and herniation. The procedure is performed through a hemi- or periareolar incision. The technique is versatile for managing the different variations of tuberous breasts, making it another interesting option for correction of the deformity. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . PMID:24902914

Oroz-Torres, Javier; Pelay-Ruata, María-Josefa; Escolán-Gonzalvo, Nieves; Jordán-Palomar, Elena

2014-08-01

329

Altered inhibition in Tuberous Sclerosis and Type IIb cortical dysplasia  

PubMed Central

Objective The most common neurological symptom of tuberous sclerosis complex (TSC) and focal cortical dysplasia (FCD) is early-life refractory epilepsy. As previous studies have shown enhanced excitatory glutamatergic neurotransmission in TSC and FCD brains, we hypothesized that neurons associated with these lesions may also express altered GABAA receptor (GABAAR)-mediated inhibition. Methods Expression of the GABAAR subunits?1 and ?4, the Na+-K+-2Cl? (NKCC1), and the K+?Cl? (KCC2) transporters in human TSC and FCD Type II specimens were analyzed by Western blot and double label immunocytochemistry. GABAAR responses in dysplastic neurons from a single case of TSC were measured by perforated-patch recording and compared to normal-appearing cortical neurons from a non-TSC epilepsy case. Results TSC and FCD Type IIb lesions demonstrated decreased expression of the GABAAR ?1, increased NKCC1 and decreased KCC2 levels. In contrast, FCD Type IIa lesions showed decreased ?4, and increased expression of both NKCC1 and KCC2 transporters. Patch clamp recordings from dysplastic neurons in acute slices from TSC tubers demonstrated excitatory GABAAR responses that were significantly attenuated by the NKCC1 inhibitor bumetanide, in contrast to hyperpolarizing GABAAR-mediated currents in normal neurons from non-TSC cortical slices. Interpretation Expression and function of GABAARs in TSC and FCD IIb suggests the relative benzodiazepine insensitivity and more excitatory action of GABA compared to FCD IIa. These factors may contribute to resistance of seizure activity to anticonvulsants that increase GABAergic function, and may justify add-on trials of the NKCC1 inhibitor bumetanide for the treatment of TSC and FCD Type IIb related epilepsy. PMID:22447678

Talos, Delia M.; Sun, Hongyu; Kosaras, Bela; Joseph, Annelise; Folkerth, Rebecca D.; Poduri, Annapurna; Madsen, Joseph R.; Black, Peter M.; Jensen, Frances E.

2012-01-01

330

Synesthesia: When colors count  

Microsoft Academic Search

A tacitly held assumption in synesthesia research is the unidirectionality of digit–color associations. This notion is based on synesthetes' report that digits evoke a color percept, but colors do not elicit any numerical impression. In a random color generation task, we found evidence for an implicit co-activation of digits by colors, a finding that constrains neurological theories concerning cross-modal associations

Daria Knoch; Lorena R. R. Gianotti; Christine Mohr; Peter Brugger

2005-01-01

331

Development of a Starch Iodide Method for the Determination of Phosphite in Natural Waters.  

NASA Astrophysics Data System (ADS)

Phosphorus (P) is believed to occur almost exclusively in the environment as fully oxidized phosphate (H3PO4, oxidation state +V). Recent developments in the field of microbiology and research on the origin of life have suggested a possibly significant role for reduced, inorganic forms of P such as phosphorus acid [H3PO3, P(+III)], hypophosphorus acid [H3PO2, P(+I)] and various forms of phosphides [P(-III)] in the biogeochemical cycling of P. In order to confirm the importance of reduced forms of P, we need to develop new and better methods for the detection of these compounds in the environment, often at levels below 1 mM. Traditional methods of P determination are based on the reaction of P with acidified molybdate in aqueous solution to yield phosphomolybdate heteropolyacid, which is then reduced and analyzed spectrophotometrically to quantify the total amount of P in the sample. Limitations in this technique have resulted in our development of a new method using a starch iodide complex for the detection of phosphorus acid or phosphite. Under laboratory conditions, phosphite [P (+III)] is oxidized to phosphate [P (+V)] by tri-iodide (I3). Starch reacts with excess tri-iodide present in solution to form a blue colored complex having a ? max of 580 nm. The I3, as well as other species such as I5, are responsible for the formation of the complex when they fit inside the coiled amylose structure of starch. Linear determination is possible in water samples containing 1 - 80 mM of P (+III). Measurement of the loss of blue color complex can then be correlated with phosphite concentration in the starting sample. Current efforts to optimize this method in order to reach limits of detection below 1 mM are underway. We believe that with better detection methods, the evidence for reduced P in the environment will increase. Due to chemical kinetics, microbial activity, surface catalyzed reactions and possible storage effects, it is difficult to effectively measure the low concentrations present after removing the samples from their natural environments for laboratory analysis. Therefore, to fully understand the importance of reduced P, ultimately, we hope to develop the starch iodide method into an in situ detection technique for measuring phosphite directly in natural waters where sensitive and reliable field-based methods of analysis are needed.

Barco, R. A.; Patil, D.; Salmassi, T. M.; Hanrahan, G.

2004-12-01

332

A Review on Physicochemical and Thermorheological Properties of Sago Starch  

Microsoft Academic Search

This study was a part of a research project aiming to investigate the texture characteristics of protein - starch interaction in fish based product keropok lekor. Accordingly, the current review study focused on some physicochemical (molecular weight, viscosity, chemical composition and swelling power) and thermorheological (gelatinization, retrogradation and viscoelsticity) characteristics of sago starch alone and in mixtures with other ingredients

A. Mohamed; B. Jamilah; K. A. Abbas; R. Abdul Rahman; K. Roselina

333

Starch-metabolic growth characteristics of Humicola grisea var. thermoidea  

Microsoft Academic Search

Very low extracellular amylase levels measured during the growth of Humicola grisea var. thermoidea in starch-yeast medium appeared to be sufficient to metabolize the starch relatively rapidly. A maximum mycelial dry weight of about 65 mg was measure after six days of incubation.

P. R. Adams

1985-01-01

334

Photosynthesis and starch metabolism of chloroplasts during prolonged illumination  

Microsoft Academic Search

The starch metabolism of the chloroplasts in the leaves of Stellaria media was studied by means of electron microscopy. During the night the starch grains diminished in size but did not disappear entirely. In the light they grew due to photosynthesis. After prolonged illumination of the plant the grains almost filled up the chloroplasts. However, after an illumination of 26–27

Heikki Haapala

1969-01-01

335

Alternative utilization of wheat starch, Grafton, North Dakota  

SciTech Connect

In 1978, North Dakota State University (NDSU), in cooperation with the Economic Development Administration, completed a study of the feasibility of a vital wheat gluten starch processing plant in North Dakota. The overall objective of this study is to determine the most feasible alternatives for utilizing the by-product starch slurry from a vital wheat gluten processing plant.

Not Available

1981-02-01

336

In vitro starch digestion in sorghum flour from Algerian cultivars  

PubMed Central

This work aims to evaluate starch digestion in whole sorghum grains. Nine sorghum cultivars were sampled from the Sahara of Algeria. The structural characteristics of sorghum grains were measured. Total starch (TS) varied between 67.67% and 74.82%, digestible starch (DS) between 64.34% and 69.70%, and resistant starch (RS) ranged from 2.55% to 7.98%. The kinetic of starch digestion displayed first-order model. For all sorghum cultivars, starch were digested with different extents, DS at infinite time (D?) ranged from 52.58 to 102.13 g/100 g dry starch, while the hydrolysis index (HI) ranged from 41.55% to 76.93% and high average glycemic index (GIavg) ranged from 65.97 to 94.14. The results showed that there are differences in grain quality of Algerian sorghum cultivars. The starch fractions have acceptable nutritional value with good in vitro digestibility characteristics suitable for human health and nutrition. PMID:24936295

Souilah, Rachid; Djabali, Djaffar; Belhadi, Badreddine; Mokrane, Hind; Boudries, Nadia; Nadjemi, Boubekeur

2014-01-01

337

In vitro starch digestion in sorghum flour from Algerian cultivars.  

PubMed

This work aims to evaluate starch digestion in whole sorghum grains. Nine sorghum cultivars were sampled from the Sahara of Algeria. The structural characteristics of sorghum grains were measured. Total starch (TS) varied between 67.67% and 74.82%, digestible starch (DS) between 64.34% and 69.70%, and resistant starch (RS) ranged from 2.55% to 7.98%. The kinetic of starch digestion displayed first-order model. For all sorghum cultivars, starch were digested with different extents, DS at infinite time (D ?) ranged from 52.58 to 102.13 g/100 g dry starch, while the hydrolysis index (HI) ranged from 41.55% to 76.93% and high average glycemic index (GIavg) ranged from 65.97 to 94.14. The results showed that there are differences in grain quality of Algerian sorghum cultivars. The starch fractions have acceptable nutritional value with good in vitro digestibility characteristics suitable for human health and nutrition. PMID:24936295

Souilah, Rachid; Djabali, Djaffar; Belhadi, Badreddine; Mokrane, Hind; Boudries, Nadia; Nadjemi, Boubekeur

2014-05-01

338

Physicochemical properties of cassava starch oxidized by sodium hypochlorite.  

PubMed

In this work, cassava starch was modified by treatment with sodium hypochlorite (NaClO) at different concentrations (0.8, 2.0 and 5.0 % of active chlorine) and selected physicochemical properties of the oxidized starches were investigated. The native and modified samples were evaluated considering moisture, carboxyl content, apparent viscosity, susceptibility to syneresis, mid-infrared spectroscopy and crystallinity index. The treatment with NaClO resulted in alterations in carboxyl content of the oxidized starches that increased with increasing concentration of the oxidant. Oxidized starches also showed higher susceptibility to syneresis, as assessed by the release of liquid during freezing and thawing. Apparent viscosity analysis showed decrease in peak viscosity of the oxidized starches. X-ray diffractograms showed that the oxidation influenced the extent of cassava starch relative crystallinity found to lie between 34.4 % (native) and 39.9 % (2.0 % active chlorine). The infrared spectra are sensitive to structural changes on starch macromolecules and presented characteristic peaks as C-O-C of the six carbon glucose ring absorbs at 1,150-1,085 cm(-1) and due to axial deformation these bands changed with the crystal structure of the starch samples. PMID:25328206

Garrido, Lúcia Helena; Schnitzler, Egon; Zortéa, Manoela Estefânea Boff; de Souza Rocha, Thaís; Demiate, Ivo Mottin

2014-10-01

339

68 CEREAL CHEMISTRY Variability in Starch Acetylation Efficiency  

E-print Network

hybrids also were observed for native samples. Modified starches are common ingredients in food influences numerous processes associated with corn milling. Peplinski et al (1989) dry-milled corn from content and drying temperature on starch yield during postharvest handling were hybrid- dependent. De Boer

340

Starch utilization by yeasts: mutants resistant of carbon catabolite repression  

Microsoft Academic Search

Twenty-seven yeasts were screened for starch breakdown; the three with the highest rate were strains of Filobasidium capsuligenum, Lipomyces starkeyi and Schwanniomyces occidentalis. Of these, only the last gave mutants with diminished carbon catabolite repression and, hence, enhanced amylase activity. Unlike those yeasts previously reported to break down starch rapidly, these mutants had the commercially advantageous characteristic of growing only

A. Kate McCann; J. A. Barnett

1984-01-01

341

Cationic starches on cellulose surfaces. A study of polyelectrolyte adsorption  

Microsoft Academic Search

Cationic starches are used on a large scale in paper industry as wet-end additives. They improve dry strength. retention of fines and fillers, and drainage. Closure of the white water systems in the paper mills hase increased the concentration of detrimental substances. This might be the reason for the poor retention of cationic starches observed in the last few years.The

Steeg van de H. G. M

1992-01-01

342

Pseudoaneurysm After Spontaneous Rupture of Renal Angiomyolipoma in Tuberous Sclerosis: Successful Treatment with Percutaneous Thrombin Injection  

SciTech Connect

We report a case of a large perinephric pseudoaneurysm due to spontaneous rupture of renal angiomyolipoma, occluded by percutaneous thrombin injection under ultrasound guidance in a young woman affected by tuberous sclerosis.

Corso, Rocco, E-mail: roccocorso@jumpy.it; Carrafiello, Gianpaolo; Rampoldi, Antonio [Niguarda 'Ca Granda' Hospital, Department of Diagnostic and Interventional Radiology (Italy); Leni, Davide [University of Milan, Institute of Radiology (Italy); Ticca, Cristiana [Niguarda 'Ca Granda' Hospital, Department of Diagnostic and Interventional Radiology (Italy); Vercelli, Ruggero [University of Milan, Institute of Radiology (Italy); Vanzulli, Angelo [Niguarda 'Ca Granda' Hospital, Department of Diagnostic and Interventional Radiology (Italy)

2005-04-15

343

Multiple Cardiac Rhabdomyomas, Wolff-Parkinson-White Syndrome, and Tuberous Sclerosis: An Infrequent Combination  

PubMed Central

Cardiac rhabdomyomas are benign cardiac tumours and are often associated with tuberous sclerosis. They are often asymptomatic with spontaneus regresion but can cause heart failure, arrhythmias, and obstruction. There have also been a few isolated reports of Wolff-Parkinson-White syndrome occurring in association with tuberous sclerosis and the great majority has been detected in patients with concomitant rhabdomyomas. We report a 12-day-old infant girl with tuberous sclerosis who presented with intraparietal and intracavitary rhabdomyomas with a Wolff-Parkinson-White syndrome (WPW). She represents one of the few published cases of WPW syndrome and tuberous sclerosis and particularly interesting because of intramural rhabdomyomas regression with persistent intracavitary rhabdomyomas after two years of followup.

Castilla Cabanes, Elena; Lacambra Blasco, Isaac

2014-01-01

344

Structures of octenylsuccinylated starches: effects on emulsions containing ?-carotene.  

PubMed

Starches with different amylopectin contents and different molecular sizes prepared using acid hydrolysis were hydrophobically modified using octenylsuccinic anhydride (OSA). The OSA-modified starches were used as surfactants to stabilize emulsions of ?-carotene and canola oil dispersed in water. The objective of this study is to investigate the relationship between starch molecular structure and the chemical stability of the emulsified ?-carotene, as well as the colloidal stability of emulsion droplets during storage. The oil droplet size in emulsions was smaller when starch had (a) lower hydrodynamic volume (Vh) and (b) higher amylopectin content. The oxidative stability of ?-carotene was similar across samples, with higher results at increased amylopectin content but higher Vh. Steric hindrance to coalescence provided by adsorbed OSA-modified starches appears to be improved by more rigid molecules of higher degree of branching. PMID:25129720

Sweedman, Michael C; Hasjim, Jovin; Schäfer, Christian; Gilbert, Robert G

2014-11-01

345

Biocontrol of black scurf on potato by seed tuber treatment with Pythium oligandrum  

Microsoft Academic Search

The biological control activity of Pythiumoligandrum against black scurf of potato caused by Rhizoctoniasolani AG-3 was evaluated in field experiments after treatment of potato seed tubers with P.oligandrum. Seed tubers infected with black scurf sclerotia were dipped for a few seconds in a suspension of 103, 104 or 105 mL-1P.oligandrum oospores and were then air-dried. Each level of P. oligandrum-treatment

Sachiko Ikeda; Ayano Shimizu; Motoshige Shimizu; Hideki Takahashi; Shigehito Takenaka

346

Catalase inhibition accelerates dormancy release and sprouting in potato (Solanum tuberosum L.) tubers  

Microsoft Academic Search

The involvement of hydrogen peroxide (H2O2) metabolism in dormancy release and sprouting of potato (Solanum tuberosum L.) tubers has been investigated using three complementary approaches. In the fi rst approach, the evolution of the sprouting kinetics, H2O2 content and antioxidant enzyme activities were examined during tuber storage. The most important changes occurred at the « bud\\/sprout » level. In particular,

Mohammed Bajji; Frédéric Gastiny

2007-01-01

347

Detection of Erwinia carotovora var. atroseptica in potato tubers with immunofluorescence following induction of decay  

Microsoft Academic Search

Summary  The simplest method of inducing tubers to decay in order to detect contamination by the blackleg organism,Erwinia carotovora var.atroseptica, was to wound them and place them in a mist chamber for four days. Incubating the decayed tubers in air for a further two\\u000a days improved detection of the blackleg organism by immunofluorescence, which was a more sensitive test than the

H. Vruggink; S. H. De Boer

1978-01-01

348

Resistance of tubers from different potato cultivars to soft rot caused by Erwinia carotovora subsp. atroseptica  

Microsoft Academic Search

Mechanically harvested tubers of 14 potato cultivars grown on both loamy sand and silt loam soils were evaluated for resistance\\u000a to bacterial soft rot caused byErwinia carotovora subsp.atroseptica. Cultivars were also assayed for calcium and dry matter content to determine possible correlations with soft rot resistance.\\u000a \\u000a Resistance of potato tubers to bacterial soft rot was assayed after harvest by inoculating

Kuo-Ching Tzeng; Raymond G. McGuire; Arthur Kelman

1990-01-01

349

Polyamine titer and biosynthetic enzymes during tuber formation of Helianthus tuberosus  

Microsoft Academic Search

During the formation ofHelianthus tuberosus tubers the activities of arginine decarboxylase (ADC) and S-adenosylmethionine decarboxylase (SAMDC), examined in medullary\\u000a parenchyma cells, increase with the increase in weight of the tuber. The ornithine decarboxylase (ODC) activity is about 100-fold\\u000a less with respect to ADC activity, and it was detected only during the deceleration phase of the growth curve. Spermidine\\u000a and spermine

N. Bagni; P. Barbieri; P. Torrigiani

1983-01-01

350

Distribution of oxidase enzymes in potato tubers relative to blackspot susceptibility II. Peroxidase and Catalase  

Microsoft Academic Search

Peroxidase and catalase activities in selected potato tuber tissue were studied for differences and possible association with\\u000a resistance or susceptibility to blackspot. Unbruised stem-end tissue had significantly greater peroxidase activity than did\\u000a unbruised bud-end tissue. However, there was no significant difference between catalase activity at either end of the tuber;\\u000a between blackspot susceptibility and peroxidase or catalase activity; and between

M. L. Weaver; E. Hautala; R. M. Reeve

1971-01-01

351

Molecular cloning of ascorbate peroxidase in potato tubers and its response during storage at low temperature  

Microsoft Academic Search

To investigate the response of ascorbate peroxidase (APx; EC 1.11.1.11) to low-temperature stress in potato tubers, a cDNA clone encoding APx was isolated from a potato tuber cDNA library. The full-length clone contains a cDNA that is 1039 bp in length and has an open reading frame of 750 bp coding for 250 amino acids. The deduced amino acid sequence

Sachiko Kawakami; Yoshio Matsumoto; Akiko Matsunaga; Shigeyuki Mayama; Masashi Mizuno

2002-01-01

352

Amylolytic activity in stored potato tubers. 1. Estimation using p -nitrophenyloligosaccharides  

Microsoft Academic Search

Summary  Methods for the estimation of amylolytic activity are reviewed. A procedure for the routine extraction of amylolytic activity\\u000a from freeze-dried powder prepared from potato tubers is described. The extraction medium is buffered at pH 7.0 and contains\\u000a glycerol, dithiothreitol, calcium chloride and the non-ionic detergent, nonidet P-40. ?-Amylase activity and exoamylolytic\\u000a activity were estimated in crude extracts of potato tubers

M. Patricia Cochrane; Carol M. Duffus; M. J. Allison; G. R. Mackay

1991-01-01

353

Substrate specificity and product inhibition of different forms of fructokinases and hexokinases in developing potato tubers  

Microsoft Academic Search

The substrate dependence and product inhibition of three different fructokinases and three different hexokinases from growing potato (Solanum tuberosum L.) tubers was investigated. The tubers contained three specific fructokinases (FK1, FK2, FK3) which had a high affinity for fructose Km=64, 90 and 100 (µM) and effectively no activity with glucose or other hexose sugars. The affinity for ATP (Km=26, 25

Andreas Renz; Mark Stitt

1993-01-01

354

Oral immunisation of naive and primed animals with transgenic potato tubers expressing LT-B  

Microsoft Academic Search

The efficacy of edible vaccines produced in potato tubers was examined in mice. Transgenic plants were developed by Agrobacterium tumefaciens-mediated transformation. The antigen selected was the non-toxic B subunit of the Escherichia coli enterotoxin (recLT-B). A synthetic gene coding for recLT-B was made and optimised for expression in potato tubers and accumulation in the endoplasmic reticulum. Introduction of this gene

T. G. M. Lauterslager; D. E. A. Florack; T. J. van der Wal; J. W. Molthoff; J. P. M. Langeveld; D. Bosch; L. A. Th. Hilgers

2001-01-01

355

Porous starch extracted from Chinese rice wine vinasse: characterization and adsorption properties.  

PubMed

Chinese rice wine vinasse (the fermentation residue after removal of the crude wine or beer) contains 20-30% residual native starch. These starches are partly hydrolyzed by amylase and glucoamylase during rice wine fermentation, indicating that it is a potential source of porous starch, which is a value-added material. In the present study, morphological, short-range order, crystalline, and thermal studies were determined to characterize the structural and chemical properties of vinasse starch. The results showed that vinasse starch granule had a rough and porous shape and was much more ordered than native starch. Vinasse starch also could tolerate a higher temperature than native starch. The water and oil adsorptive capacities of vinasse starch were 1.89 and 4.14 times higher than that of native rice starch. These results suggest that vinasse is an effective and economical source of porous starch for using as adsorbent. PMID:23850681

Li, Hongyan; Jiao, Aiquan; Wei, Benxi; Wang, Yong; Wu, Chunsen; Jin, Zhengyu; Tian, Yaoqi

2013-10-01

356

Dynamic vapor sorption properties of sodium starch glycolate disintegrants.  

PubMed

Dynamic vapor sorption (DVS) was used to determine the moisture sorption properties of sodium starch glycolates. The results were compared to similarly obtained data for potato starch, pregelatinized starch, microcrystalline cellulose (MCC), and crystalline lactose. As expected, sodium starch glycolates exhibit a large mass gain at 90% relative humidity (RH), compared to the other anhydroglucose-based excipients. However, the sorption capacities of potato starch and the modified starches between 10%-70% RH were similar. Analysis of the DVS data using the Brunauer-Emmett-Teller (BET) and Guggenheim, Anderson, and deBoer (GAB) theories to obtain the so-called monolayer (Xm), as expected, showed that there was an increasing Xm with apparent mass gain that is probably related to crystallinity, purity, and surface area and represents the number and accessibility of amorphous anhydroglucose units present. The value of x(m) was related to the degree of crystallinity or order as determined by X-ray diffraction, suggesting that x(m) can be used to further describe the amorphous nature of semi-crystalline polymers containing anhydroglucose units, in particular the chemically modified sodium starch glycolate. Additionally, it appears that the sorption capacity between 10%-70% RH is not dramatically affected by the presence or type of cross-linking and sodium carboxymethylation (in sodium starch glycolates) and gelatinization (in pregelatinized starch) and that the superdisintegrant properties of the sodium starch glycolates are a consequence of some water-structure interaction that is well beyond the available number of hydration sites, as represented by x(m). Further evaluation of the structure and sorption properties of excipients may aid the development of disintegrants for solid dosage forms. PMID:15926674

Young, Paul M; Edge, Stephen; Staniforth, John N; Steele, D Fraser; Price, Robert

2005-01-01

357

Shear thickening of corn starch suspensions: does concentration matter?  

PubMed

Suspensions of corn starch and water are the most common example of a shear thickening system. Investigations into the non-Newtonian flow behavior of corn starch slurries have ranged from simplistic elementary school demonstrations to in-depth rheological examinations that use corn starch to further elucidate the mechanisms that drive shear thickening. Here, we determine how much corn starch is required for the average person to ‘‘walk on water’’ (or in this case, run across a pool filled with corn starch and water). Steady shear rate rheological measurements were employed to monitor the thickening of corn starch slurries at concentrations ranging from 0 to 55 wt.% (0-44 vol.%). The steady state shear rate ramp experiments revealed a transition from continuous to discontinuous thickening behavior that exists at 52.5 wt.%. The rheological data was then compared to macro-scopic (~5 gallon) pool experiments, in which thickening behavior was tested by dropping a 2.1 kg rock onto the suspension surface. Impact-induced thickening in the ‘‘rock drop’’ study was not observed until the corn starch concentration reached at least 50 wt.%. At 52.5 wt.%, the corn starch slurry displayed true solid-like behavior and the falling rock ‘‘bounced’’ as it impacted the surface. The corn starch pool studies were fortified by steady state stress ramps which were extrapolated out to a critical stress value of 67,000 Pa (i.e., the force generated by an 80 kg adult while running). Only the suspensions containing at least 52.5 wt.% (42 vol.%) thickened to high enough viscosities (50-250 Pa s) that could reasonably be believed to support the impact of a man’s foot while running. Therefore, we conclude that at least 52.5 wt.% corn starch is required to induce strong enough thickening behavior to safely allow the average person to ‘‘walk on water’’. PMID:23484772

Crawford, Nathan C; Popp, Lauren B; Johns, Kathryn E; Caire, Lindsey M; Peterson, Brittany N; Liberatore, Matthew W

2013-04-15

358

Comparison of ectomycorrhizal communities in natural and cultivated Tuber melanosporum truffle grounds.  

PubMed

Truffles are hypogeous ectomycorrhizal (EM) fungi belonging to the genus Tuber. Although outplanting of truffle-inoculated host plants has enabled the realization of productive orchards, truffle cultivation is not yet standardized. Therefore, monitoring the distribution of fungal species in different truffle fields may help us to elucidate the factors that shape microbial communities and influence the propagation and fruiting of Tuber spp. In this study, we compared the fungal biodiversity in cultivated and natural Tuber melanosporum truffle fields located in Central Italy. To this end, ectomycorrhizas (ECM) and soil samples were molecularly analyzed, and an inventory of the fungi associated with Quercus pubescens plants colonized by T. melanosporum, Tuber aestivum or Tuber brumale was compiled. T. melanosporum and T. aestivum were dominant on the cultivated plants, and the number of EM species was markedly lower in the cultivated sites than in the natural sites. However, in the same site, EM biodiversity was higher in T. brumale-colonized plants than in T. melanosporum-colonized plants. These results suggest that different Tuber spp. may have different competitive effects on the other mycobionts. Additionally, in keeping with our previous findings, we found that the number of T. melanosporum genotypes recovered from the soil samples was higher than that of the underlying ECM. PMID:22469019

Belfiori, Beatrice; Riccioni, Claudia; Tempesta, Sabrina; Pasqualetti, Marcella; Paolocci, Francesco; Rubini, Andrea

2012-09-01

359

Anaerobic Nitrate Respiration by Erwinia carotovora subsp. atroseptica during Potato Tuber Invasion  

PubMed Central

The in planta induction of anaerobic nitrate respiration by Erwinia carotovora subsp. atroseptica in relation to the in situ oxygen status in soft rotting potato tubers has been investigated. In vitro experiments have shown that nitrate was required for the induction of respiratory nitrate reductase activity in E. carotovora. In addition, oxygen was found to repress this activity. Expression of respiratory nitrate reductase was found in E. carotovora cells extracted from soft rotting potato tuber tissue. However, the rate of nitrite production in these cells was approximately 70-fold lower than the rate recorded in fully induced anaerobic cultures. Oxygen measurements in soft rotting potato tubers indicated that the invading bacteria encounter the lowest oxygen concentration at the interphase between healthy and macerated tissue. Consequently, growth of bacteria present in this specific zone will be stimulated by nitrate which is present in sufficient amounts in tuber tissue. A high nitrate content of the tuber will most likely facilitate the proliferation of E. carotovora in the tuber tissue. PMID:16349082

Smid, Eddy J.; Jansen, Antonius H. J.; Tuijn, Cees J.

1993-01-01

360

Yellow nutsedge (Cyperus esculentus L. ) control with herbicides: the role of tuberization  

SciTech Connect

Trials were carried out under greenhouse, growth chamber, laboratory, outdoor pot, and field conditions to characterize stages of yellow nutsedge tuberization and to investigate the influence of herbicides. The effects of herbicides on tuberization and phytotoxicity at several growth stages, as well as on sprouting, growth characteristics, and survival of new tubers were determined. Tuberization was a continuous process, but was modulated by plant age and environmental conditions. The growth stage that included the time of first tuber initiation was the best for applying glyphosate (N-(phosphonomethyl)glycine) and oxyfluorfen (2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluromethyl)benzene). Plant-age and length of period after spraying influenced glyphosate and oxyfluorfen absorption and translocation. Addition of unlabelled oxyfluorfen as a tank mixture can glyphosate increased absorption of /sup 14/C-glyphosate to 27% after 1 day and 46% after 8 days and increased translocation into other plant parts. Timing of postemergence herbicide applications relative to tuberization is crucial for overall control of yellow nutsedge. When soil applied herbicides were compared in the field, consecutive applications of dichlobenil (2,6-dichlorobenzonitrile) and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide) for two years provided the best control of nutsedge.

Pereira, W.

1985-01-01

361

Rapamycin reverses impaired social interaction in mouse models of tuberous sclerosis complex  

PubMed Central

Impairment of reciprocal social interaction is a core symptom of autism spectrum disorder. Genetic disorders frequently accompany autism spectrum disorder, such as tuberous sclerosis complex caused by haploinsufficiency of the TSC1 and TSC2 genes. Accumulating evidence implicates a relationship between autism spectrum disorder and signal transduction that involves tuberous sclerosis complex 1, tuberous sclerosis complex 2 and mammalian target of rapamycin. Here we show behavioural abnormalities relevant to autism spectrum disorder and their recovery by the mammalian target of rapamycin inhibitor rapamycin in mouse models of tuberous sclerosis complex. In Tsc2+/? mice, we find enhanced transcription of multiple genes involved in mammalian target of rapamycin signalling, which is dependent on activated mammalian target of rapamycin signalling with a minimal influence of Akt. The findings indicate a crucial role of mammalian target of rapamycin signalling in deficient social behaviour in mouse models of tuberous sclerosis complex, supporting the notion that mammalian target of rapamycin inhibitors may be useful for the pharmacological treatment of autism spectrum disorder associated with tuberous sclerosis complex and other conditions that result from dysregulated mammalian target of rapamycin signalling. PMID:23250422

Sato, Atsushi; Kasai, Shinya; Kobayashi, Toshiyuki; Takamatsu, Yukio; Hino, Okio; Ikeda, Kazutaka; Mizuguchi, Masashi

2012-01-01

362

Antisense downregulation of the barley limit dextrinase inhibitor modulates starch granule size distribution, starch composition and amylopectin structure  

Microsoft Academic Search

Summary The barley protein limit dextrinase inhibitor (LDI), structurally related to the a-amylase\\/trypsin inhibitor family, is an inhibitor of the starch debranching enzyme limit dextrinase (LD). In order to investigate the function of LDI, and the consequences for starch metabolism of reduced LDI activity, transgenic barley plants designed to downregulate LDI by antisense were generated. Homozygous antisense lines with reduced

Yvonne Stahl; Steve Coates; James H. Bryce; Peter C. Morris

2004-01-01

363

Biotechnological production of colorants.  

PubMed

The color of food and drinks is important, as it is associated with freshness and taste. Despite that natural colorants are more expensive to produce, less stable to heat and light, and less consistent in color range, natural colorants have been gaining market share in recent years. The background is that artificial colorants are often associated with negative health aspects. Considerable progress has been made towards the fermentative production of some colorants. Because colorant biosynthesis is under close metabolic control, extensive strain and process development are needed in order to establish an economical production process. Another approach is the synthesis of colors by means of biotransformation of adequate precursors. Algae represent a promising group of microorganisms that have shown a high potential for the production of different colorants, and dedicated fermentation and downstream technologies have been developed. This chapter reviews the available information with respect to these approaches. PMID:24037500

de Boer, Lex

2014-01-01

364

From A Physical Color Stimulus To A Psychological Color Percept  

NASA Astrophysics Data System (ADS)

The paper discusses the complexity of color vision in humans, considering the main aspects involved: the physical aspect, the psychophysical aspect, the physiological aspect and the psychological aspect. The meanings of the term color associated to each such aspect (asfor example, color stimulus, color valence, neural color signal and color percept) are introduced. Some types of color defective vision, relevant for color display users, are indicated. The methods to generate color stimuli in modern display devices, employing different technologies, are compared.

Sporea, Dan G.; Tonnquist, Gunnar

1989-08-01

365

Effect of cultivar, location and year on total starch, amylose, phosphorus content and starch grain size of high starch potato cultivars for food and industrial processing.  

PubMed

In recent time the interest of industry increases particularly in processing and use of potato high amylopectin (AMP) starches. Therefore the plant breeders effort to obtain "waxy" potato cultivars with low amylose (AMS) content. In this four-year study sixteen potato cultivars grown on five experimental locations were evaluated on the percentage of AMS/AMP by enzymatic method, starch content by the underwater weight method, phosphorus (P) content in starch digests spectrophotometrically, and starch granule size determined by laser diffraction method. Between enzymatic and iodine-potassium iodide method good correlation has been revealed (r=0.71). The correlation analysis between AMS and P levels showed a clear negative correlation. For all measured parameters (starch, AMS, P, starch granule size) significant impact of cultivar has been determined. Location and year have lower, but significant impact. No statistically significant effect of year on AMS has been found. The cultivar Amado distinguished with the highest AMP and P contents and the cultivar Westamyl showed all positive values interesting for growers and processors. PMID:23993560

Šimková, Dagmar; Lachman, Jaromír; Hamouz, Karel; Vokál, Bohumil

2013-12-15

366

Colors of maximal saturation.  

PubMed

The spectrum locus on the CIE Chromaticity Diagram represents monochromatic stimuli which have been exposed to a dark adapted fovea. Some of these colors can be made to appear more saturated by chromatic adaptation. The colors both inside the spectrum locus and the supersaturated colors outside are bounded by a four-sided boundary line which constitutes the locus of colors of maximal saturation. An attempt has been made to show how this quadrilateral is related to the fundamental colors and to a zone theory of color vision. PMID:8539020

Fry, G A

1995-08-01

367

Radiation coloration resistant glass  

DOEpatents

A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

Tomozawa, Minoru (Troy, NY); Watson, E. Bruce (Troy, NY); Acocella, John (Troy, NY)

1986-01-01

368

Radiation coloration resistant glass  

DOEpatents

A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

Tomozawa, M.; Watson, E.B.; Acocella, J.

1986-11-04

369

Architectural analysis of root system of sexually vs. vegetatively propagated yam ( Dioscorea rotundata Poir.), a tuber monocot  

Microsoft Academic Search

Architectural descriptors were used to understand root system structure and development in white yam (Dioscorea rotundata\\u000a Poir., Dioscoreaceae), a tuber monocot. Observations were made on seedlings and plant derived from tuber fragments, cultivated\\u000a in greenhouses over a developmental cycle. This study demonstrated that both seedlings and plants derived from tubers have\\u000a two distinct root systems that are highly organized. The

Tristan Charles-Dominique; Thomas Mangenet; Hervé Rey; Christophe Jourdan; Claude Edelin

2009-01-01

370

The role of the seed tuber in the contamination by Erwinia carotovora of potato crops in Scotland  

Microsoft Academic Search

Some mother tubers rotted as early as July and most were extensively rotted by the end of August.Erwinia carotovora var.carotovora andE. carotovora var.atroseptica were frequently isolated from them and from the soil in their vicinity. Daughter tubers became contaminated only after the rotting mother tubers had liberated bacteria into the soil. By the end of August and early September most

M. C. M. Pérombelon

1974-01-01

371

Effect of infection by Phytophthora infestans on phenolics in potato tubers with various degrees of field resistance  

Microsoft Academic Search

Browning of potato tubers infected withPhytophthora infestans was correlated with field resistance. The composition of brown material extracted from tubers was investigated by preparing alkaline-neutral difference spectra, which were similar to those obtained from a model system of tuber cell walls incubated with ferulic or p-coumaric acids and H2O2. The activities of L-phenylalanine ammonia lyase, peroxidase and phenolase in wounded

J. McLauchlin

1983-01-01

372

Physicochemical and Functional Properties of Sour Starches from Different Cassava Varieties  

Microsoft Academic Search

This article reports our investigation on the effect of cassava varieties on the physicochemical and functional properties of sour starches. There were significant differences (P < 0.05) in the ash, pH, amylose, amylopectin, starch damage, total titratable acidity (TTA), sugar, and starch content but not moisture contents of various cassava sour starches. There were no significant differences (P > 0.05)

M. O. Onitilo; L. O. Sanni; O. B. Oyewole; B. Maziya-Dixon

2007-01-01

373

Impact of Starch Properties on Hearth Bread Characteristics. II. Purified A- and B-granule Fractions  

Microsoft Academic Search

Starch and A- and B-granule fractions were purified from 6 different bread wheat flours with similar protein content. For each starch fraction the starch granular size distribution, gelatinisation, pasting, and gelation properties were measured. In addition the chain length of amylopectin was obtained. The results from the analyses of flour and purified starch fractions were related to the properties of

S. Sahlström; A. B. Bævre; E. Bråthen

2003-01-01

374

Effects of Amylomaize Starch on Mineral Metabolism in the Adult Rat: Role of the Microflora  

Microsoft Academic Search

The effects of amylomaize starch on rat mineral metabolism were studied. To elucidate the role of bacterial fermentation, the effects of amylomaize starch were compared in germfree (GF) and conventional (CV) rats. A purified diet, sterilized by irradiation and containing either maize starch (M) or amylomaize starch (A), was fed to the rats. Feed intake was similar in all groups

CLAUDE ANDRIEUX

375

Transient starch metabolism in ornamental tobacco floral nectaries regulates nectar composition and release  

Microsoft Academic Search

Enlargement of the floral nectary gland of ornamental tobacco during its development is accompanied by a major accumulation of starch granules in nectary amyloplasts. Quantification of starch in the nectary at various developmental stages showed little starch accumulation at early stages but increasing amounts of starch over the course of nectary development that reached a peak approximately 24h prior to

Gang Ren; Rosanne A. Healy; Anna M. Klyne; Harry T. Horner; Martha G. James; Robert W. Thornburg

2007-01-01

376

Antisense RNA mediated inhibition of granule-bound starch synthase gene expression in potato  

Microsoft Academic Search

Potato starch and its derivatives are widely used in several fields of application. The manufacturing of most products requires the modification of native starch with respect to, for example, viscosity and physical stability. In addition to the currently used physical, chemical and biochemical derivatization and gelatinization of extracted starch, modification of the starch biosynthetic pathway in planta is regarded as

G. J. Kuipers

1994-01-01

377

Study on the properties of ethylenebisformamide and sorbitol plasticized corn starch (ESPTPS)  

Microsoft Academic Search

A mixed plasticizer (ethylenebisformamide and sorbitol) was used to the preparation of thermoplastic starch (TPS). And the other three TPSs were prepared as a contradistinction, including glycerol plasticized starch (GPTPS), ethylenebisformamide plasticized starch (EPTPS), and sorbitol plasticized starch (SPTPS). FT-IR expressed that the microcosmic chemical environments of the group in all these TPSs mentioned above shifted to lower frequency compared

Jin-hui Yang; Jiu-gao Yu; Xiao-fei Ma

2006-01-01

378

Chemical compositions, fine structure and physicochemical properties of kudzu ( Pueraria lobata) starches from different regions  

Microsoft Academic Search

Three commercial kudzu starches from Vietnam, Japan and Korea were used to determine chemical compositions, isoflavone compounds, fine structure and physicochemical properties. The kudzu starch from Vietnam had polygonal granules, whereas the kudzu starches from Japan and Korea contained both polygonal and spherical granules. Total protein, lipid, ash and phosphorus contents present in these kudzu starches were less than 1%

Pham Van Hung; Naofumi Morita

2007-01-01

379

Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation  

Microsoft Academic Search

In most plants, a large fraction of photo-assimilated carbon is stored in the chloroplasts during the day as starch and remobilized during the subsequent night to support metabolism. Mutations blocking either starch synthesis or starch breakdown in Arabidopsis thaliana reduce plant growth. Maltose is the major product of starch breakdown exported from the chloroplast at night. The maltose excess 1

Michaela Stettler; Simona Eicke; Tabea Mettler; Gaelle Messerli; Stefan Hortensteiner; Samuel C. Zeeman

2009-01-01

380

Starch hydrolysis modeling: application to fuel ethanol production.  

PubMed

Efficiency of the starch hydrolysis in the dry grind corn process is a determining factor for overall conversion of starch to ethanol. A model, based on a molecular approach, was developed to simulate structure and hydrolysis of starch. Starch structure was modeled based on a cluster model of amylopectin. Enzymatic hydrolysis of amylose and amylopectin was modeled using a Monte Carlo simulation method. The model included the effects of process variables such as temperature, pH, enzyme activity and enzyme dose. Pure starches from wet milled waxy and high-amylose corn hybrids and ground yellow dent corn were hydrolyzed to validate the model. Standard deviations in the model predictions for glucose concentration and DE values after saccharification were less than ± 0.15% (w/v) and ± 0.35%, respectively. Correlation coefficients for model predictions and experimental values were 0.60 and 0.91 for liquefaction and 0.84 and 0.71 for saccharification of amylose and amylopectin, respectively. Model predictions for glucose (R2 = 0.69-0.79) and DP4+ (R2 = 0.8-0.68) were more accurate than the maltotriose and maltose for hydrolysis of high-amylose and waxy corn starch. For yellow dent corn, simulation predictions for glucose were accurate (R2 > 0.73) indicating that the model can be used to predict the glucose concentrations during starch hydrolysis. PMID:21487699

Murthy, Ganti S; Johnston, David B; Rausch, Kent D; Tumbleson, M E; Singh, Vijay

2011-09-01

381

Drying and cracking mechanisms in a starch slurry.  

PubMed

Starch-water slurries are commonly used to study fracture dynamics. Drying starch cakes benefit from being simple, economical, and reproducible systems, and have been used to model desiccation fracture in soils, thin-film fracture in paint, and columnar joints in lava. In this paper, the physical properties of starch-water mixtures are studied, and used to interpret and develop a multiphase transport model of drying. Starch cakes are observed to have a nonlinear elastic modulus, and a desiccation strain that is comparable to that generated by their maximum achievable capillary pressure. It is shown that a large material porosity is divided between pore spaces between starch grains, and pores within starch grains. This division of pore space leads to two distinct drying regimes, controlled by liquid and vapor transport of water, respectively. The relatively unique ability for drying starch to generate columnar fracture patterns is shown to be linked to the unusually strong separation of these two transport mechanisms. PMID:19905189

Goehring, Lucas

2009-09-01

382

Modeling of lactose crystallization and color changes in model infant foods.  

PubMed

Lactose crystallization and color changes in formulas containing beta-lactoglobulin and gelatinized starch were investigated. Model infant formulas were prepared by colyophilization of 3 components (lactose, beta-lactoglobulin, and gelatinized starch). A mixture design was used to choose the percentage of each mixture component. These formulas were stored for 3 mo at different relative humidities (RH), ranging from approximately 0 to 94.6%, to study the lactose crystallization and color changes. Crystallization kinetics was studied by gravimetric methods, and lactose state (crystalline vs. amorphous) was verified before and after storage by differential scanning calorimetry. Before storage, lyophilized lactose was amorphous, but during storage it crystallized, depending on the RH. The lactose crystallization RH depended on the quantity of beta-lactoglobulin and gelatinized starch, and by increasing these quantities, the crystallization RH increased. For some formulas, the crystallization RH was noted at 3 different RH during storage. The first was noted after 1 d of storage and the second and third were observed later on, showing that crystallization is a time-dependent phenomenon. Nonenzymatic browning was studied in model infant formulas by yellow color changes of samples at 11.3, 43.2, 54.5, and 75.4% RH. In this study, 7 mathematical models were proposed to predict the moisture sorption properties and color changes at different RH, and the models were validated by experimental results. PMID:16772552

Nasirpour, A; Scher, J; Linder, M; Desobry, S

2006-07-01

383

Selection of a set of specific primers for the identification of Tuber rufum: a truffle species with high genetic variability.  

PubMed

Tuber rufum is a truffle widely distributed throughout Europe, which forms mycorrhizal associations with numerous species of broadleaf and coniferous trees. The possibility of T. rufum contamination in commercial truffle-infected plants makes its detection important. To facilitate the identification of T. rufum from mycorrhiza and fruitbodies, species-specific primers were designed and tested. To overcome the high intraspecific genetic variability within the internal transcribed spacer (ITS) regions of T. rufum, as demonstrated by phylogenetic analysis, two forward primers, Ru1f and Ru2f, located on the ITS1 region were designed to be used in concert with the reverse primer ITS4. Only T. rufum was amplified with this primer combination, while DNA of Tuber magnatum, Tuber brumale, Tuber maculatum, Tuber borchii, Tuber excavatum and Tuber melanosporum was not. These primers give a specific amplicon ranging between 566 and 572 bp and are able to discriminate between T. rufum, T. borchii and T. magnatum in multiplex PCR. In addition, T. rufum-specific amplicons were obtained from both spore suspensions and mycorrhiza by direct PCR. Tuber rufum mycorrhiza obtained in the greenhouse using mycelial inoculation techniques had morphological features similar to those of other species of Tuber, stressing the importance of molecular tools for their identification. PMID:18031344

Iotti, Mirco; Amicucci, Antonella; Bonito, Gregory; Bonuso, Enrico; Stocchi, Vilberto; Zambonelli, Alessandra

2007-12-01

384

Flavonoid profiling and transcriptome analysis reveals new gene-metabolite correlations in tubers of Solanum tuberosum L.  

PubMed Central

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns associated with the accumulation of purple tuber anthocyanins. The advanced potato selections, CO97216-3P/PW and CO97227-2P/PW, developed by conventional breeding procedures, produced tubers with incomplete expression of tuber flesh pigmentation. This feature permits sampling pigmented and non-pigmented tissues from the same tubers, in essence, isolating the factors responsible for pigmentation from confounding genetic, environmental, and developmental effects. An examination of the transcriptome, coupled with metabolite data from purple pigmented sectors and from non-pigmented sectors of the same tuber, was undertaken to identify these genes whose expression correlated with elevated or altered polyphenol composition. Combined with a similar study using eight other conventional cultivars and advanced selections with different pigmentation, it was possible to produce a refined list of only 27 genes that were consistently differentially expressed in purple tuber tissues compared with white. Within this list are several new candidate genes that are likely to impact on tuber anthocyanin accumulation, including a gene encoding a novel single domain MYB transcription factor. PMID:20110266

Stushnoff, Cecil; Ducreux, Laurence J. M.; Hancock, Robert D.; Hedley, Pete E.; Holm, David G.; McDougall, Gordon J.; McNicol, James W.; Morris, Jenny; Morris, Wayne L.; Sungurtas, Julie A.; Verrall, Susan R.; Zuber, Tatiana; Taylor, Mark A.

2010-01-01

385

Wheat genome specific granule-bound starch synthase I differentially influence grain starch synthesis.  

PubMed

Wheat grain development is a complex process and is characterized by changes in physicochemical and structural properties of starch. The present study deals with endosperm starch physicochemical properties and structure during development in different granule-bound starch synthase I (GBSSI) null also known as waxy (Wx) genotypes. The study was conducted with pure starch isolated from wheat grains at 3-30 days post anthesis (DPA), at 3-day intervals. Amylose concentration increased throughout grain development in non-waxy (7.2-30.5%) and partial waxy genotypes (6.0-26.8%). Completely waxy genotype showed 7.0% amylose at 3 and 6DPA, which declined during development and reached non-detectable quantities by 30DPA. Amylopectin structure had a higher content of short chains at 3DPA, which decreased continuously until 12DPA, after which there were only minor changes in amylopectin chain length distribution. Similarly, the average degree of polymerization (DP) increased from 3DPA (12.3) to 12DPA (15.0), and then did not differ significantly up to 30DPA (15.0). This suggests the formation of basic amylopectin architecture in wheat by 12DPA. Wx-B and Wx-D affected amylopectin short chains mostly of DP 6-8 at 3 and 6DPA. Wx-A affected the same fraction of chains at 9 and 12DPA, and Wx-D affected DP 18-25 chains from 18 to 30DPA, suggesting differential effect of waxy isoproteins on amylopectin structure formation. PMID:25263868

Ahuja, Geetika; Jaiswal, Sarita; Hucl, Pierre; Chibbar, Ravindra N

2014-12-19

386

Show Your Colors!  

NSDL National Science Digital Library

In this family or group activity, learners conduct a chromatography experiment to reveal the colors that leaves "hide" under their green pigments. Use this experiment to predict what colors the leaves will "turn" in the fall.

Park, Smithsonian N.

2011-08-20

387

Color realism redux  

E-print Network

Our reply is in three parts. The first part concerns some foundational issues in the debate about color realism. The second part addresses the many objections to the version of physicalism about color (“productance ...

Byrne, Alex

388

The Trouble with Color.  

ERIC Educational Resources Information Center

Discusses problems with color quality in Web sites. Topics include differences in monitor settings, including contrast; amount of video RAM; user preference settings; browser-safe colors; cross-platform readability; and gamma values. (LRW)

Merchant, David

1999-01-01

389

Light, Color, and Mirrors.  

ERIC Educational Resources Information Center

Describes an exercise in which students can use flashlights, mirrors, and colored paper to discover scientific principles regarding optics. Addresses the concepts of angles of incidence and reflection, colored vs. white light, and mirror images. (WRM)

Tiburzi, Brian; Tamborino, Laurie; Parker, Gordon A.

2000-01-01

390

Molecular structure of starches from maize mutants deficient in starch synthase III.  

PubMed

Molecular structures of starches from dull1 maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were characterized and compared with the wild type. Amylose content with altered structure was higher in the nonwaxy mutants (25.4-30.2%) compared to the wild type maize (21.5%) as revealed by gel permeation chromatography. Superlong chains of the amylopectin component were found in all nonwaxy samples. Unit chain length distribution of amylopectins and their ?,?-limit dextrins (reflecting amylopectin internal structure) from dull1 mutants were also characterized by anion-exchange chromatography after debranching. Deficiency of SSIII led to an increased amount of short chains (DP ?36 in amylopectin), whereas the content of long chains decreased from 8.4% to between 3.1 and 3.7% in both amylopectin and ?,?-limit dextrins. Moreover, both the external and internal chain lengths decreased, suggesting a difference in their cluster structures. Whereas the molar ratio of A:B-chains was similar in all samples (1.1-1.2), some ratios of chain categories were affected by the absence of SSIII, notably the ratio of "fingerprint" A-chains to "clustered" A-chains. This study highlighted the relationship between SSIII and the internal molecular structure of maize starch. PMID:23967805

Zhu, Fan; Bertoft, Eric; Källman, Anna; Myers, Alan M; Seetharaman, Koushik

2013-10-16

391

Quantum Dots and Colors  

NSDL National Science Digital Library

Students are introduced to the physical concept of the colors of rainbows as light energy in the form of waves with distinct wavelengths, but in a different manner than traditional kaleidoscopes. Looking at different quantum dot solutions, they make observations and measurements, and graph their data. They come to understand how nanoparticles interact with absorbing photons to produce colors. They learn the dependence of particle size and color wavelength and learn about real-world applications for using these colorful liquids.

National Science Foundation GK-12 and Research Experience for Teachers (RET) Programs,

392

Down to Earth: Colors  

NSDL National Science Digital Library

Students identify the actual colors of objects bathed in monochromatic light and learn how three colors of light can be combined to produce colors ranging from black to white. Students see how space observatories make use of monochromatic filters to collect data on the color of objects in space. The activity is in unit four of the "Space-Based Astronomy" guide that contains background information, worksheets, assessment activities, extensions, and alignment to national education standards.

393

Wastewater purification in the potato starch industry  

SciTech Connect

Deproteinized and protein-containing wastewater from the potato starch industry was purified by anaerobic digestion followed by aerobic treatment. Inhibition of methanation by NH3 in concentrated deproteinized wastewater can be prevented by lowering the pH. SO32- was removed by reduction in an acidification-reactor. SO42- reduction was hydraulic retention time-dependent during acidification. Further elimination of SO42- can take place in the CH4 reactor. With both deproteinized and protein-containing wastewater, high CH4 production rates were obtained (more than or equal to 26 kg COD/cubic m-day). Aerobic treatment of the anaerobic effluent resulted in extensive deodorization and concomitant elimination of BOD and PO4(-3).

Wijbenga, D.J.; Meiberg, J.B.M.; Brunt, K.

1984-01-01

394

Effects of grain development on formation of resistant starch in rice.  

PubMed

Three rice mutants with different contents of resistant starch (RS) were selected to investigate the effects of grain filling process on the formation of resistant starch. During grain development, the content of RS was increased with grain maturation and showed negative correlations with the grain weight and the starch molecular weight (Mn, Mw) and a positive correlation with the distribution of molecular mass (polydispersity, Pd). The morphologies of starch granules in high-RS rice were almost uniform in single starch granules and exhibited different proliferation modes from common rice. The lower activities of ADP-glucose pyrophosphorylase and starch branching enzyme and the higher activity of starch synthase and starch de-branching enzyme observed in high-RS rice might be responsible for the formation of small irregular starch granules with large spaces between them. In addition, the lower molecular weight and the broad distribution of molecular weights lead to differences in the physiochemical properties of starch. PMID:24996310

Shu, Xiaoli; Sun, Jian; Wu, Dianxing

2014-12-01

395

Synthesis of starch derivatives with labile cationic groups.  

PubMed

A new route to starch derivatives bearing hydrolyzable cationic groups was developed. This was based on reacting starch compounds with betaine derivatives in the presence of diisopropylcarbodiimide and 4-dimethylaminopyridine as coupling reagents in an aprotic polar solvent. Water-soluble starches with a perfectly controlled degree of substitution were thus obtained which were fully characterized by infrared, 1H and 13C spectroscopy and viscosity measurements. The cationic groups grafted on the polysaccharides are shown to hydrolyze slowly upon storage at room temperature. PMID:12568919

Auzély-Velty, Rachel; Rinaudo, Marguerite

2003-01-15

396

Spinning Your (Color) Wheels  

NSDL National Science Digital Library

In this optics activity, learners use everyday materials to make a color wheel. When learners spin the wheel like a top, they will be surprised to see all the colors mixing together to appear white. Use this activity to introduce learners to color and the visible spectrum.

America, Optical S.

2008-01-01

397

Color imaging for multimedia  

Microsoft Academic Search

To a significant degree, multimedia applications derive their effectiveness from the use of color graphics, images, and video. However, the requirements for accurate color reproduction and for the preservation of this information across display and print devices that have very different characteristics and may be geographically apart are often not clearly understood. This paper describes the basics of color science,

GAURAV SHARMA; MICHAEL J. VRHEL; H. JOEL TRUSSELL

1998-01-01

398

Strong Colorings of Hypergraphs  

Microsoft Academic Search

A strong vertex coloring of a hypergraph assigns distinct col- ors to vertices that are contained in a common hyperedge. This captures many previously studied graph coloring problems. We present nearly tight upper and lower bound on approximating general hypergraphs, both oine and online. We then consider various parameters that make coloring easier, and give a unied treatment. In particular,

Geir Agnarsson; Magnús M. Halldórsson

2004-01-01

399

Color Discrimination Work Sample.  

ERIC Educational Resources Information Center

This manual contains a work sample intended to assess a handicapped student's ability to see likenesses or differences in colors or shades, identifying or matching certain colors, and selecting colors that go together. Section 1 describes the assessment and lists related occupations and DOT codes. Instructions to the evaluator are provided in the…

Shawsheen Valley Regional Vocational-Technical High School, Billerica, MA.

400

Biology of Skin Color.  

ERIC Educational Resources Information Center

Information from scientific journals on the biology of skin color is discussed. Major areas addressed include: (1) biology of melanin, melanocytes, and melanosomes; (2) melanosome and human diversity; (3) genetics of skin color; and (4) skin color, geography, and natural selection. (JN)

Corcos, Alain

1983-01-01

401

Reimagining the Color Wheel  

ERIC Educational Resources Information Center

Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

Snyder, Jennifer

2011-01-01

402

Response of potato tuber cell division and growth to shade and elevated CO2.  

PubMed

Plants adjust their sink-organ growth rates, development and distribution of dry matter in response to whole-plant photosynthate status. To advance understanding of these processes, potato (Solanum tuberosum L.) plants were subjected to CO(2) and light flux treatments, and early tuber growth was assessed. Atmospheric CO(2) (700 or 350 micro mol mol(-1)) and light flux (shade and control illumination) treatments were imposed at two growth stages: tuber initiation (TI) and tuber bulking (TB). Elevated CO(2) increased accumulation of total net biomass when imposed at both stages, and increased tuber growth rate by about 36 %, but did not increase the number of tubers. Elevated CO(2) increased the number of cells in tubers at both TI and TB stages, whereas shade substantially decreased the number of cells at both stages. Generally, treatments did not affect cell volume or the proportion of nuclei endoreduplicating (repeated nuclear DNA replication in the absence of cell division), but the shade treatment led to a decrease in cell volume at TB and a decrease in endoreduplication at TI. Elevated CO(2) increased, and shade decreased, glucose concentration and soluble invertase activity in the cambial zones at both TI and TB, whereas sucrose concentration and activities of glucokinase, fructokinase, cell-wall-bound invertase and thymidine kinase were unaffected. Modulation of tuber cell division was responsible for much of the growth response to whole-plant photosynthate status, and treatments affected cambial-zone glucose and soluble invertase in a pattern suggesting involvement of a glucose signalling pathway. PMID:12547690

Chen, Chien-Teh; Setter, Tim L

2003-02-01

403

Response of Potato Tuber Cell Division and Growth to Shade and Elevated CO2  

PubMed Central

Plants adjust their sink?organ growth rates, development and distribution of dry matter in response to whole?plant photosynthate status. To advance understanding of these processes, potato (Solanum tuberosum L.) plants were subjected to CO2 and light flux treatments, and early tuber growth was assessed. Atmospheric CO2 (700 or 350 µmol mol–1) and light flux (shade and control illumination) treatments were imposed at two growth stages: tuber initiation (TI) and tuber bulking (TB). Elevated CO2 increased accumulation of total net biomass when imposed at both stages, and increased tuber growth rate by about 36 %, but did not increase the number of tubers. Elevated CO2 increased the number of cells in tubers at both TI and TB stages, whereas shade substantially decreased the number of cells at both stages. Generally, treatments did not affect cell volume or the proportion of nuclei endoreduplicating (repeated nuclear DNA replication in the absence of cell division), but the shade treatment led to a decrease in cell volume at TB and a decrease in endoreduplication at TI. Elevated CO2 increased, and shade decreased, glucose concentration and soluble invertase activity in the cambial zones at both TI and TB, whereas sucrose concentration and activities of glucokinase, fructokinase, cell?wall?bound invertase and thymidine kinase were unaffected. Modulation of tuber cell division was responsible for much of the growth response to whole?plant photosynthate status, and treatments affected cambial?zone glucose and soluble invertase in a pattern suggesting involvement of a glucose signalling pathway. PMID:12547690

CHEN, CHIEN?TEH; SETTER, TIM L.

2003-01-01

404

Reactivation of meristem activity and sprout growth in potato tubers require both cytokinin and gibberellin.  

PubMed

Reactivation of dormant meristems is of central importance for plant fitness and survival. Due to their large meristem size, potato (Solanum tuberosum) tubers serve as a model system to study the underlying molecular processes. The phytohormones cytokinins (CK) and gibberellins (GA) play important roles in releasing potato tuber dormancy and promoting sprouting, but their mode of action in these processes is still obscure. Here, we established an in vitro assay using excised tuber buds to study the dormancy-releasing capacity of GA and CK and show that application of gibberellic acid (GA(3)) is sufficient to induce sprouting. In contrast, treatment with 6-benzylaminopurine induced bud break but did not support further sprout growth unless GA(3) was administered additionally. Transgenic potato plants expressing Arabidopsis (Arabidopsis thaliana) GA 20-oxidase or GA 2-oxidase to modify endogenous GA levels showed the expected phenotypical changes as well as slight effects on tuber sprouting. The isopentenyltransferase (IPT) from Agrobacterium tumefaciens and the Arabidopsis cytokinin oxidase/dehydrogenase1 (CKX) were exploited to modify the amounts of CK in transgenic potato plants. IPT expression promoted earlier sprouting in vitro. Strikingly, CKX-expressing tubers exhibited a prolonged dormancy period and did not respond to GA(3). This supports an essential role of CK in terminating tuber dormancy and indicates that GA is not sufficient to break dormancy in the absence of CK. GA(3)-treated wild-type and CKX-expressing tuber buds were subjected to a transcriptome analysis that revealed transcriptional changes in several functional groups, including cell wall metabolism, cell cycle, and auxin and ethylene signaling, denoting events associated with the reactivation of dormant meristems. PMID:21163959

Hartmann, Anja; Senning, Melanie; Hedden, Peter; Sonnewald, Uwe; Sonnewald, Sophia

2011-02-01

405

Amyloplast-localized SUBSTANDARD STARCH GRAIN4 protein influences the size of starch grains in rice endosperm.  

PubMed

Starch is a biologically and commercially important polymer of glucose and is synthesized to form starch grains (SGs) inside amyloplasts. Cereal endosperm accumulates starch to levels that are more than 90% of the total weight, and most of the intracellular space is occupied by SGs. The size of SGs differs depending on the plant species and is one of the most important factors for industrial applications of starch. However, the molecular machinery that regulates the size of SGs is unknown. In this study, we report a novel rice (Oryza sativa) mutant called substandard starch grain4 (ssg4) that develops enlarged SGs in the endosperm. Enlargement of SGs in ssg4 was also observed in other starch-accumulating tissues such as pollen grains, root caps, and young pericarps. The SSG4 gene was identified by map-based cloning. SSG4 encodes a protein that contains 2,135 amino acid residues and an amino-terminal amyloplast-targeted sequence. SSG4 contains a domain of unknown function490 that is conserved from bacteria to higher plants. Domain of unknown function490-containing proteins with lengths greater than 2,000 amino acid residues are predominant in photosynthetic organisms such as cyanobacteria and higher plants but are minor in proteobacteria. The results of this study suggest that SSG4 is a novel protein that influences the size of SGs. SSG4 will be a useful molecular tool for future starch breeding and biotechnology. PMID:24335509

Matsushima, Ryo; Maekawa, Masahiko; Kusano, Miyako; Kondo, Hideki; Fujita, Naoko; Kawagoe, Yasushi; Sakamoto, Wataru

2014-02-01

406

Mutants of Arabidopsis Lacking Starch Branching Enzyme II Substitute Plastidial Starch Synthesis by Cytoplasmic Maltose Accumulation[W  

PubMed Central

Three genes, BE1, BE2, and BE3, which potentially encode isoforms of starch branching enzymes, have been found in the genome of Arabidopsis thaliana. Although no impact on starch structure was observed in null be1 mutants, modifications in amylopectin structure analogous to those of other branching enzyme II mutants were detected in be2 and be3. No impact on starch content was found in any of the single mutant lines. Moreover, three double mutant combinations were produced (be1 be2, be1 be3, and be2 be3), and the impact of the mutations on starch content and structure was analyzed. Our results suggest that BE1 has no apparent function for the synthesis of starch in the leaves, as both be1 be2 and be1 be3 double mutants display the same phenotype as be2 and be3 separately. However, starch synthesis was abolished in be2 be3, while high levels of ?-maltose were assayed in the cytosol. This result indicates that the functions of both BE2 and BE3, which belong to class II starch branching enzymes, are largely redundant in Arabidopsis. Moreover, we demonstrate that maltose accumulation depends on the presence of an active ADP-glucose pyrophosphorylase and that the cytosolic transglucosidase DISPROPORTIONATING ENZYME2, required for maltose metabolization, is specific for ?-maltose. PMID:17028209

Dumez, Sylvain; Wattebled, Fabrice; Dauvillee, David; Delvalle, David; Planchot, Veronique; Ball, Steven G.; D'Hulst, Christophe

2006-01-01

407

Polymorphism in the barley granule bound starch synthase 1 (gbss1) gene associated with grain starch variant amylose concentration.  

PubMed

Granule bound starch synthase 1 (GBSS1) accumulation within starch granules and structure of Gbss1 alleles were determined for nine barley ( Hordeum vulgare L.) genotypes producing amylose-free (undetectable), near-waxy (1.6-4.5%), normal (25.8%), and increased (38.0-40.8%) amylose grain starches. Compared to normal starch granules, GBSS1 accumulation was severely reduced in three near-waxy, slightly reduced in two waxy, and slightly elevated in three increased amylose starches. Gbss1 nucleotide sequence analysis for the nine genotypes distinguished them into three Gbss1 groups with several single-nucleotide polymorphisms. A new unique Q312H substitution within GBSS1 was discovered in near-waxy genotype SB94912 with reduced amylose (1.6%) concentration relative to the other two near-waxy lines, CDC Rattan and CDC Candle (4.5%). The two waxy genotype GBSS1 showed a previously described D287V change for CDC Alamo and a new G513W change for CDC Fibar. Both amino acid alterations are conserved residues within starch synthase domains involved in glucan interaction. The increased amylose genotypes showed several unique nucleotide changes within the second and fourth Gbss1 introns, but only SB94893 GBSS1 showed a unique amino acid substitution, A250T in exon 6. The Gbss1 nucleotide differences were used to design genetic markers to monitor Gbss1 alleles in genotypes with various amylose grain starches. PMID:22950712

Asare, Eric K; Båga, Monica; Rossnagel, Brian G; Chibbar, Ravindra N

2012-10-10

408

Tuber melanosporum, when dominant, affects fungal dynamics in truffle grounds.  

PubMed

The fruiting bodies of the ectomycorrhizal (ECM) fungus Tuber melanosporum are usually collected in an area devoid of vegetation which is defined as a 'burnt area' (brulé in French). Here, the soil fungal populations of inside and outside brulé were compared in order to understand whether the scanty plant cover was related to a change in fungal biodiversity. Both denaturing gradient gel electrophoresis (DGGE) and molecular cloning of the internal transcribed spacer (ITS) marker were employed on soil DNA to obtain profiles from nine truffle grounds and fungal sequences from one selected truffle ground sampled in two years. Denaturant gradient gel electrophoresis profiles from the two areas formed two distinct clusters while molecular cloning allowed 417 fungal sequences to be identified. T. melanosporum was the dominant fungus within the brulé. There were nine new haplotypes, which had never been detected in fruiting bodies. The Basidiomycota ECM fungi decreased within the brulé, indicating a competitive effect of T. melanosporum on the other ECM fungi. Among other factors, the dynamics of fungal populations seems to be correlated to brulé formation. PMID:19825014

Napoli, Chiara; Mello, Antonietta; Borra, Ambrogio; Vizzini, Alfredo; Sourzat, Pierre; Bonfante, Paola

2010-01-01

409

Phylogeny and phylogeography of the Tuber brumale aggr.  

PubMed

The Tuber brumale (winter truffle) is a black truffle reported from most European countries, belonging to the Melanosporum group. Its significance in the economy is ambivalent as the winter truffle has been shown to be a frequent contaminant species in the orchards of the Perigord truffle and occasionally in those of the summer truffle, yet owing to its delicate fragrance, its trade is worthy of note. The phylogeny and phylogeography of economically important truffles are relatively well-explored; however, no thorough research has been published on these aspects of the winter truffle. Therefore, here, we report the first phylogeographic analyses based on samples representing the entire distribution of the species. ITS sequences were used in this survey for haplotype and coalescent analyses, while phylogenetic analyses were based on the ITS, LSU and PKC loci. According to all loci, the samples clustered into two big clades imply the existence of two phylogenetic species. Based on our results, one of these appears to be endemic to the Carpathian Basin. In the other more widespread species, two main phylogeographic groups can be distinguished that show east-west separation with a zone of overlap in the Carpathian Basin, suggesting that they survived the latest glacial period in separate refugia. PMID:24604084

Merényi, Zsolt; Varga, Torda; Geml, József; Orczán, Ákos Kund; Chevalier, Gerard; Bratek, Zoltán

2014-04-01

410

Homologous inhibitors from potato tubers of serine endopeptidases and metallocarboxypeptidases.  

PubMed Central

A potent polypeptide inhibitor of chymotrypsin has been purified from Russett Burbank potatoes. The inhibitor has no effect on bovine carboxypeptidases A or B but exhibits homology with a carboxypeptidase inhibitor that is also present in potato tubers. The chymotrypsin inhibitor has a molecular weight of approximately 5400 as estimated by gel filtration, amino acid analysis, and titration with chymotrypsin. The polypeptide chain consists of 49 amino acid residues, of which six are half-cystine, forming three disulfide bonds. Its size is similar to that of the carboxypeptidase inhibitor, which contains 39 amino acid residues and also has three disulfide bridges. In immunological double diffusion assays, the chymotrypsin inhibitor and the carboxypeptidase inhibitor do not crossreact; however, automatic Edman degradation of reduced and alkylated derivatives of the chymotrypsin inhibitor, yielding a partial sequence of 18 amino acid residues at the NH2-terminus, reveals a similarity in sequence to that of the carboxypeptidase inhibitor. Thus, inhibitors directed toward two distinct classes of proteases, the serine endopeptidases and the metallocarboxypeptidases, appear to have evolved from a common ancestor. Images PMID:1064864

Hass, C M; Venkatakrishnan, R; Ryan, C A

1976-01-01

411

Tuber aestivum association with non-host roots.  

PubMed

Mycorrhizal fungi provide direct and functional interconnection of soil environment with their host plant roots. Colonization of non-host plants have occasionally been described, but its intensity and functional significance in complex plant communities remain generally unknown. Here, the abundance of ectomycorrhizal fungus Tuber aestivum was measured in the roots of host and non-host (non-ectomycorrhizal) plants in a naturally occurring T. aestivum colony using a quantitative PCR approach. The roots of non-host plant species found inside the brûlé area were extensively colonized by T. aestivum mycelium, although the levels were significantly lower than those found in host Carpinus betulus roots. However, fungal biomass concentration in the non-host roots was one to two orders of magnitude higher than that in the surrounding soil. This indicates existence of an important biotic interaction between T. aestivum mycelium and the non-host, mostly herbaceous plants. Roots, either host or non-host, thus probably constitute hot spots of T. aestivum activity in the soil ecosystem with as yet uncovered functional significance. PMID:24756631

Gryndler, Milan; Cerná, Lucie; Bukovská, Petra; Hršelová, Hana; Jansa, Jan

2014-11-01

412

Impaired synaptic plasticity in a rat model of tuberous sclerosis.  

PubMed

Tuberous sclerosis complex (TSC) is a common hereditary disorder caused by mutations in either the TSC1 or TSC2 genes, and characterized by severe epilepsy, cerebral hamartomas and mental retardation. We have used rats that are heterozygous for an autosomal-dominant germline mutation in the TSC2 gene (TSC2+/- rats) to examine the consequences of TSC2 mutations for hippocampal synaptic plasticity. While basal synaptic transmission in the Schaffer collateral-CA1 synapse was not altered, paired-pulse plasticity was significantly enhanced in TSC2+/- rats (interpulse intervals 20-200 ms). Moreover, TSC2+/- rats exhibited a marked reduction of different forms of synaptic plasticity. Long-term potentiation (LTP) elicited following high-frequency tetanization of Schaffer collaterals was significantly decreased from 1.45 +/- 0.05-fold potentiation to 1.15 +/- 0.04 (measured after 60 min). This difference in LTP levels between TSC2+/- and wild-type rats also persisted in the presence of the gamma-aminobutyric acid (GABA)(A) receptor antagonist bicuculline. In addition to changed LTP, the level of long-term depression (LTD) elicited by different forms of low-frequency stimulation was significantly less in TSC2+/- rats. These results suggest that TSC2 mutations may cause hippocampal synapses to lose much of their potential for activity-dependent synaptic modification. An understanding of the underlying molecular pathways may suggest new therapeutic approaches aimed at inhibiting the development of the profound mental retardation in TSC. PMID:16487150

von der Brelie, Christian; Waltereit, Robert; Zhang, Lian; Beck, Heinz; Kirschstein, Timo

2006-02-01

413

Nitrogen recycling during phenylpropanoid metabolism in sweet potato tubers  

NASA Technical Reports Server (NTRS)

In the first step of the phenylpropanoid metabolic pathway, L-phenylalanine (L-Phe) is deaminated to form E-cinnamate, in a conversion catalyzed by phenylalanine ammonia-lyase (PAL; EC 4.3.1.5). The metabolic fate of the ammonium ion (NH4+) produced in this reaction was investigated in sweet potato (Ipomoea batatas) tuber discs. [15N]-Labeled substrates including L-Phe, in the presence or absence of specific enzyme inhibitors, were administered to sweet potato discs in light under aseptic conditions. 15N-Nuclear magnetic resonance spectroscopic analyses revealed that the 15NH4+ liberated during the PAL reaction is first incorporated into the amide nitrogen of L-glutamine (L-Gln) and then into L-glutamate (L-Glu). These results extend our previous observations in pine and potato that PAL-generated NH4+ is assimilated by the glutamine synthetase (GS; EC 6.3.1.2)/glutamate synthase (GOGAT; EC 1.4.1.13) pathway, with the NH4+ so formed ultimately being recycled back to L-Phe via L-Glu as aminoreceptor and donor.

Singh, S.; Lewis, N. G.; Towers, G. H.

1998-01-01

414

Rheological Properties of Dough Made with Starch and Gluten from Several Cereal Sources  

Microsoft Academic Search

Cereal Chem. 72(l):53-58 The range in moduli for isolated starch and vital gluten doughs showed action of the starch with the gluten. The source of gluten also had a the existence of starch-gluten or starch-gluten-water interactions in dough. significant effect on dough rheology, as indicated by the range of elastic Starches isolated from different wheat cultivars and mixed into dough

K. E. PETROFSKY; R. C. HOSENEY

415

N -(2-Hydroxyethyl)formamide as a new plasticizer for thermoplastic starch  

Microsoft Academic Search

N-(2-Hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new plasticizer for corn starch to prepare thermoplastic\\u000a starch (TPS). The hydrogen bond interaction between HF and starch was proved by Fourier-transform infrared (FT-IR) spectroscopy.\\u000a Scanning electron microscope (SEM) revealed that starch granules were completely disrupted and a continuous phase was obtained.\\u000a The crystallinity of corn starch and HF-plasticized TPS (HTPS)

Hongguang Dai; Peter R. Chang; Fei Peng; Jiugao Yu; Xiaofei Ma

2009-01-01

416

Effect of granular characteristics on the viscoelastic properties of composites of amylose and waxy starches  

Microsoft Academic Search

For elucidating the influence of granular properties on the viscoelastic characteristics of starch gel, in this study waxy corn and waxy rice starches pre-heated at different temperatures were mixed with amylose isolated from normal corn starch to form amylose–waxy starch composites. Rheological properties of the amylose, the waxy starches and the composites during aging at 25°C were determined and compared.

Ting-Jang Lu; Chi-Shen Duh; Jheng-Hua Lin; Yung-Ho Chang

2008-01-01

417

Integrated functions among multiple starch synthases determine both amylopectin chain length and branch linkage location in Arabidopsis leaf starch.  

PubMed

This study assessed the impact on starch metabolism in Arabidopsis leaves of simultaneously eliminating multiple soluble starch synthases (SS) from among SS1, SS2, and SS3. Double mutant ss1- ss2- or ss1- ss3- lines were generated using confirmed null mutations. These were compared to the wild type, each single mutant, and ss1- ss2- ss3- triple mutant lines grown in standardized environments. Double mutant plants developed similarly to the wild type, although they accumulated less leaf starch in both short-day and long-day diurnal cycles. Despite the reduced levels in the double mutants, lines containing only SS2 and SS4, or SS3 and SS4, are able to produce substantial amounts of starch granules. In both double mutants the residual starch was structurally modified including higher ratios of amylose:amylopectin, altered glucan chain length distribution within amylopectin, abnormal granule morphology, and altered placement of ?(1?6) branch linkages relative to the reducing end of each linear chain. The data demonstrate that SS activity affects not only chain elongation but also the net result of branch placement accomplished by the balanced activities of starch branching enzymes and starch debranching enzymes. SS3 was shown partially to overlap in function with SS1 for the generation of short glucan chains within amylopectin. Compensatory functions that, in some instances, allow continued residual starch production in the absence of specific SS classes were identified, probaby accomplished by the granule bound starch synthase GBSS1. PMID:21624979

Szydlowski, Nicolas; Ragel, Paula; Hennen-Bierwagen, Tracie A; Planchot, Véronique; Myers, Alan M; Mérida, Angel; d'Hulst, Christophe; Wattebled, Fabrice

2011-08-01

418

Molecular Expressions: Color Separation  

NSDL National Science Digital Library

This item is an interactive Java simulation for introductory physics students on the topic of color. It explores how individual subtractive primary colors can be separated from a full-color photograph and then be reassembled to create the original scene. The mouse cursor may be used to superimpose color separations over one another. As additional separations are added, the resulting image exhibits the realism of a color photograph. This item is part of a larger collection of materials on optics and microscopy developed by the National High Magnetic Field Laboratory and Florida State University.

Davidson, Michael; Parry-Hill, Matthew J.; Sutter, Robert

2008-08-21

419

Color quality inspection and compensation for color LED display modules  

Microsoft Academic Search

The paper presents an automated color inspection and compensation solutions for color LED modules which are main components of a color LED display panel. Initially, a self-developed color optical sensing module and a colorimeter were used to measure the colors of LED pixels. After the color matching functions from the collected data was corrected by least-squares approximation method, the calibrated

Ming-Jong Tsai; Shu-Huai Chang; Chia-Liang Lee; Chia-Te Chou

2011-01-01

420

Color planner for designers based on color emotions  

Microsoft Academic Search

During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of

Ka-Man Cheng; John H. Xin; Gail Taylor

2002-01-01

421

Rainbow Coloring of Graphs Rainbow Coloring of Graphs  

E-print Network

Rainbow Coloring of Graphs Rainbow Coloring of Graphs L. Sunil Chandran Computer Science and Automation Indian Institute of Science, Bangalore Email: sunil@csa.iisc.ernet.in #12;Rainbow Coloring of Graphs What is Rainbow Coloring? Consider an edge coloring, not necessarily proper. #12;Rainbow Coloring

Narasayya, Vivek

422

Color Classification of Coordination Compounds.  

ERIC Educational Resources Information Center

Proposes that colored compounds be classified by reference to a standard color-order system incorporating a color dictionary. Argues that the colors of new compounds could be incorporated into the characterization process and into computer storage systems. (TW)

Poncini, Laurence; Wimmer, Franz L.

1987-01-01

423

Color Use in Design  

NSDL National Science Digital Library

In this activity, you will learn a little bit about color theory and how it can effect the colors that you choose for a design. This activity covers the Arizona State CTE Standard for demonstrating drawing and visualization skills required for graphic communications (Standard #13). Read each section below carefully and follow the links provided to find more information on the topics discussed. When you are finished with the lesson, complete the assignment at the bottom of the screen. Introduction There are certain colors that look good together in designs and there is a reason for it. Colors that look good together are based on their relationship to each other on a color wheel. In the following lesson, you are going explore the color wheel and the color relationships ...

Pope

2008-10-07

424

The in vitro effects of retrograded starch (resistant starch type 3) from lotus seed starch on the proliferation of Bifidobacterium adolescentis.  

PubMed

Prebiotics such as oligosaccharides, fructans, and resistant starch (RS) stimulate the growth of beneficial bacteria in large bowel and modify the human gastrointestinal environment. In this study, compared with glucose (GLU) and high amylose maize starch (HAMS), the in vitro effects of LRS3 and P-LRS3 (RS3 and purified RS3 prepared from lotus seed starch) on the proliferation of bifidobacteria were assessed by assessing the changes in optical density (OD), pH values, short chain fatty acid (SCFA) production, and tolerance ability to gastrointestinal conditions. Significantly higher OD values were obtained from media containing LRS3 and P-LRS3, and especially in the medium containing P-LRS3, the OD value of which reached 1.36 when the concentration of the carbon source was 20 g L(-1). Additionally, the lag phase of bifidobacteria was 8 h in the medium with LRS3 or P-LRS3, whereas it was 16 h in the medium with GLU or HAMS. What is more, a higher content of butyric acid was obtained in the P-LRS3 medium. Compared with GLU and HAMS media, bifidobacteria had a higher tolerance to gastrointestinal conditions in LRS3 and P-LRS3 media. It shows that lotus seed resistant starch, especially P-LRS3, could stimulate the growth of bifidobacteria. The rough surface of resistant starch and the SCFAs produced during fermentation might influence the proliferation of bifidobacteria. PMID:24056635

Zhang, Yi; Wang, Ying; Zheng, Baodong; Lu, Xu; Zhuang, Weijing

2013-11-01

425

21 CFR 172.892 - Food starch-modified.  

...percent, followed by treatment with a beta -amylase enzyme that is either an approved food additive of is generally...starch may be modified by treatment with the following enzymes: Enzyme Limitations Alpha-amylase (E.C....

2014-04-01

426

Properties of starch from potatoes differing in glycemic index.  

PubMed

Potatoes are a popular source of dietary carbohydrate worldwide and are generally considered to be a high glycemic index (GI) food. Potato starch characteristics play a key role in determining their rate of digestion and resulting glycemic response. Starches isolated from seven potato cultivars with different GI values, including a low GI cultivar (Carisma), were examined for relative crystallinity, granule size distribution, amylopectin chain length, and thermal and pasting properties. Starch from the Carisma cultivar was more thermally stable and more resistant to gelatinization, with significantly higher (p < 0.05) pasting temperature and differential scanning calorimetry (DSC) gelatinization onset, peak and conclusion temperatures, compared to the other cultivars. Differences between the potatoes in the other properties measured did not align with the GI ranking. Thermal analysis and starch pasting properties may be useful indicators for preliminary identification of potato cultivars that are digested slowly and have a lower GI. PMID:25124366

Lin Ek, Kai; Wang, Shujun; Brand-Miller, Jennie; Copeland, Les

2014-10-24

427

Hydration and the phase diagram of acid hydrolyzed potato starch.  

PubMed

We investigated hydration of acid hydrolyzed potato starch (maltodextrin) employing a multi-method approach. In particular, synchrotron radiation X-ray scattering and differential scanning calorimetry were used, and, for the first time, the material was investigated with sorption calorimetry and a newly developed quartz crystal microbalance with humidity scanning. The dry starch was found to be in an amorphous state. During hydration it exhibits a glass transition in both bulk and thin film samples, followed by an exothermic event where the starch crystallized. Recrystallized bulk samples displayed neither a pronounced glass transition nor crystallization upon hydration whereas both events occurred in thin film samples. The hydration-driven crystallization resulted in an X-ray pattern consistent with the coexistence of A and B type crystallites; however, at higher water concentrations only the B form occurred. The results were used to construct the first ever acid hydrolyzed starch-water phase diagram. PMID:25129783

Carlstedt, Jonas; Wojtasz, Joanna; Fyhr, Peter; Kocherbitov, Vitaly

2014-11-01

428

Engineering Escherichia coli K12 MG1655 to use starch  

PubMed Central

Background To attain a sustainable bioeconomy, fuel, or valuable product, production must use biomass as substrate. Starch is one of the most abundant biomass resources and is present as waste or as a food and agroindustry by-product. Unfortunately, Escherichia coli, one of the most widely used microorganisms in biotechnological processes, cannot use starch as a carbon source. Results We engineered an E. coli strain capable of using starch as a substrate. The genetic design employed the native capability of the bacterium to use maltodextrins as a carbon source plus expression and secretion of its endogenous ?-amylase, AmyA, in an adapted background. Biomass production improved using 35% dissolved oxygen and pH 7.2 in a controlled bioreactor. Conclusion The engineered E. coli strain can use starch from the milieu and open the possibility of optimize the process to use agroindustrial wastes to produce biofuels and other valuable chemicals. PMID:24886307

2014-01-01

429

21 CFR 172.892 - Food starch-modified.  

Code of Federal Regulations, 2010 CFR

...by treatment with hydrochloric acid or sulfuric acid or both. (b) Food starch...hydrogen peroxide and/or peracetic acid, not to exceed 0.45 percent...calculated as phosphorus. 1-Octenyl succinic anhydride, not to exceed 3...

2010-04-01

430

Starch modification with microbial alpha-glucanotransferase enzymes.  

PubMed

Starch is an agricultural raw material used in many food and industrial products. It is present in granules that vary in shape in the form of amylose and amylopectin. Starch-degrading enzymes are used on a large scale in the production of sweeteners (high fructose corn syrup) and concentrated glucose syrups as substrate for the fermentative production of bioethanol and basic chemicals. Over the last two decades ?-glucanotransferases (EC 2.4.1.xx), such as branching enzyme (EC 2.4.1.18) and 4-?-glucanotransferase (EC 2.4.1.25), have received considerable attention. These enzymes do not hydrolyze the starch as amylases do. Instead, ?-glucanotransferases remodel parts of the amylose and amylopectin molecules by cleaving and reforming ?-1,4- and ?-1,6-glycosidic bond. Here we review the properties of ?-glucanotransferases and discuss the emerging use of these enzymes in the generation of novel starch derivatives. PMID:23465909

van der Maarel, Marc J E C; Leemhuis, Hans

2013-03-01

431

Starch utilization by yeasts: mutants resistant of carbon catabolite repression.  

PubMed

Twenty-seven yeasts were screened for starch breakdown; the three with the highest rate were strains of Filobasidium capsuligenum, Lipomyces starkeyi and Schwanniomyces occidentalis. Of these, only the last gave mutants with diminished carbon catabolite repression and, hence, enhanced amylase activity. Unlike those yeasts previously reported to break down starch rapidly, these mutants had the commercially advantageous characteristic of growing only slowly on the products of starch break-down and gave rise to readily-inducible auxotrophs. Like hex1 mutants of Saccharomyces cerevisiae, these mutants of Schwanniomyces occidentalis (i) had diminished hexokinase activity, (ii) retained high levels of glucokinase and (iii) resisted carbon catabolite repression of invertase and ?-D-glucokinase. In one mutant, isomaltase was induced in the late exponential phase of growth on starch, and this isomaltase was also resistant to repression. PMID:24177953

McCann, A K; Barnett, J A

1984-09-01

432

Characterization of modified pearl millet (Pennisetum typhoides) starch.  

PubMed

Pearl millet starch (Pennisetum typhoides) was isolated and subjected to hydrothermal, acidic and enzymatic modifications. Native and various modified starches were characterized in terms of yield, moisture, protein, ash, bulk density, swelling power, solubility, colour, sediment volume, gel consistency, water binding capacity, pasting properties, freeze thaw stability and paste clarity. Hydrothermal modification (HTMS) caused an increase in swelling power and solubility. L value was higher for acid and enzymatically modified starches (EMS). A significant reduction (p???0.05) in sediment volume and water binding capacity was observed for acid modified starch (AMS) and EMS. Peak viscosity values declined for all modifications. However, EMS and AMS showed an improved freeze-thaw stability and paste clarity. PMID:24493886

Balasubramanian, S; Sharma, R; Kaur, J; Bhardwaj, N

2014-02-01

433

Hydrolysis of starch and fermentable hydrolysates obtained therefrom  

SciTech Connect

Starch in slurry was liquefied by strong acid and a-amylase, saccharified in the presence of acid cation exchanger, and neutralized with NH/sub 4/OH to obtain an aqueous solution of fermentable sugar.

Muller, W.C.; Miller, F.D.

1981-05-05

434

Gibberellin A1 Metabolism Contributes to the Control of Photoperiod-Mediated Tuberization in Potato  

PubMed Central

Some potato species require a short-day (SD) photoperiod for tuberization, a process that is negatively affected by gibberellins (GAs). Here we report the isolation of StGA3ox2, a gene encoding a GA 3-oxidase, whose expression is increased in the aerial parts and is repressed in the stolons after transfer of photoperiod-dependent potato plants to SD conditions. Over-expression of StGA3ox2 under control of constitutive or leaf-specific promoters results in taller plants which, in contrast to StGA20ox1 over-expressers previously reported, tuberize earlier under SD conditions than the controls. By contrast, StGA3ox2 tuber-specific over-expression results in non-elongated plants with slightly delayed tuber induction. Together, our experiments support that StGA3ox2 expression and gibberellin metabolism significantly contribute to the tuberization time in strictly photoperiod-dependent potato plants. PMID:21961036

Bou-Torrent, Jordi; Martinez-Garcia, Jaime F.; Garcia-Martinez, Jose Luis; Prat, Salome

2011-01-01

435

Relationship among lipoperoxides, jasmonates and indole-3-acetic acid formation in potato tuber after wounding.  

PubMed

Plant responses to biotic and abiotic stress can be mediated by oxidised products and in this study we analysed the relation among some of them and the growth factor indole-3-acetic acid (IAA). The plant material used was potato tuber sliced below bud and incubated for different lengths of time before analysis. Wounding in potato tuber leads, in a very short time (0-30?min), to the generation of lipid hydroperoxides (LOOH) from polyunsaturated fatty acids (PUFA). These reactive species could cause a subsequent increase of 9 and 13-lipoxygenase (LOX, E.C.1.13.12.12.), analysed by RT-PCR and spectrophotometric assay, LOOH, Jasmonates and IAA all quantified by GC-MS analysis. The activation of 9 and 13-LOX, using different timing, leads to the formation of LOOH with a subsequent generation of jasmonates and IAA as highlighted by the addition on the potato tuber slices of salicylhydroxamic acid (SHAM), an inhibitor of LOX activity. A correlation between jasmonates and IAA resulted by testing their reciprocal influence during wounding in potato tuber. The relationship occurring among each hormone analysed during wounding underlines the fact that the jasmonates level can be regulated in situ and this can suggest a role for these compounds in potato tuber which has been underestimated up to now. PMID:16036342

Reverberi, Massimo; Fanelli, Corrado; Zjalic, Slaven; Briganti, Stefania; Picardo, Mauro; Ricelli, Alessandra; Fabbri, Anna Adele

2005-06-01

436

Localization of Branching Enzyme in Potato Tuber Cells with the Use of Immunoelectron Microscopy.  

PubMed Central

Potato branching enzyme, a key enzyme in the biosynthesis of starch, was localized in amyloplasts in starch-storage cells of potato (Solanum tuberosum L.) with the use of immunogold electron microscopy. Branching enzyme was found in the amyloplast stroma, concentrated at the interface of the stroma and the surface of the starch granule. ADP-glucose pyrophosphorylase, a key regulatory enzyme in starch synthesis, was localized for comparison to exclude possible artifacts. ADP-glucose pyrophosphorylase, in contrast with branching enzyme, proved to be evenly distributed throughout the stroma. Branching enzyme also appears to be present in a membrane-bounded inclusion body in the stroma, whereas ADP-glucose pyrophosphorylase is not. The presence of branching enzyme predominantly at the surface of the starch granule indicates that branching takes place at that surface and not throughout the amyloplast stroma. PMID:12231679

Kram, A. M.; Oostergetel, G. T.; Van Bruggen, EFJ.

1993-01-01

437

Thermoplastic Starch Films with Vegetable Oils of Brazilian Cerrado  

NASA Astrophysics Data System (ADS)

Biodegradable polymers are one of the most promising ways to replace non-degradable polymers. TPS films were prepared by casting from cassava starch and three different vegetable oils of Brazilian Cerrado as plasticizer: buriti, macaúba and pequi. In this preliminary work it was investigated materials thermal characteristics by TG and TMA. Thermal properties of oils depends on their chemical structures. Starch and vegetable oils are natural resources that can be used how alternative to producing materials that cause minor environmental impact.

Schlemmer, D.; Sales, M. J. A.

2008-08-01

438

Molecular and pasting properties of some wheat starches  

Microsoft Academic Search

Molecular structures and pasting properties of starches from four wheat varieties, (Egret and Rosella, soft grain; Vasco and Halberd, hard grain) were characterized and the relationships between pasting and molecular properties were analyzed. The starches (10%, w\\/w) showed pasting temperatures in the range of 63.4–67.6 °C, maximum viscosities (Vmax) 201–323 RVU, breakdown 54–176 RVU, and consistency 118–198 RVU measured by

Y. Shibanuma; Y. Takeda; S. Hizukuri

1996-01-01

439

Physicochemical changes of starch in refrigerated dough during storage  

Microsoft Academic Search

Refrigerated dough is a flour-based, unbaked product that is stored between 4 and 7°C. Maintaining the dough quality during storage is very crucial. Starch functionalities have important effects on flour and dough quality. The objective of this research was to determine the physicochemical changes of starch in refrigerated dough during extended storage. Two wheat flours with different amylose\\/amylopection ratio were

Yu Zhang; Senay Simsek

2009-01-01

440

Properties of Starches from Several Low-Amylose Rice Cultivars  

Microsoft Academic Search

Cereal Chem. 80(2):193-197 The starch properties of five low-amylose rice cultivars, Yawarako- machi, Soft 158, Hanabusa, Aya, and Snow Pearl, were compared with those of two normal amylose rice cultivars, Nipponbare and Hinohikari. There were no large differences in the distributions of the amylopectin chain length determined by high-performance anion-exchange chroma- tography, and the starch gelatinization properties determined by dif-

Takahiro Noda; Yoichi Nishiba; Tetsuo Sato; Ikuo Suda

2003-01-01

441

Dietary resistant starch and chronic inflammatory bowel diseases  

Microsoft Academic Search

These studies were performed to test the benefit of resistant starch on ulcerative colitis via prebiotic and butyrate effects.\\u000a Butyrate, propionate, and acetate are produced in the colon of mammals as a result of microbial fermentation of resistant\\u000a starch and other dietary fibers. Butyrate plays an important role in the colonic mucosal growth and epithelial proliferation.\\u000a A reduction in the

Gisela Jacobasch; Detlef Schmiedl; Martin Kruschewski; Katrin Schmehl

1999-01-01

442

Gamma-irradiation synthesis of quaternary phosphonium cationic starch flocculants.  

PubMed

Quaternary phosphonium cationic starch (St-g-AM/ATPPB) flocculant was synthesized by using corn starch and acrylamide (AM), allyl triphenyl phosphonium bromide binary (ATPPB) through simultaneous gamma-irradiation. The chemical structure of the copolymer was characterized by FTIR (Fourier transform infrared spectroscopy) and (1)H NMR (nuclear magnetic resonance) technologies. The effects of the absorbed dose in the range of 1 to 6 kGy, AM/ATPPB ratio and starch/(AM + ATPPB) ratio on grafting and flocculation were investigated. At a starch:AM:ATPPB wt ratio of 1:1.4:0.93, the graft ratio of AM/ATPPB reached maximum values at 3 and 6 kGy, and the cationic degree of St-g-AM/ATPPB increased with absorbed dose, while the turbidity reduction reached a maximum value at 5 kGy. At 3 kGy using a starch:(AM + ATPPB) wt. ratio of 1:2.33, the graft ratio of AM and ATPPB increased with AM/ATPPB ratio, while the cationic degree and turbidity reduction reached maximum values at AM:ATPPB wt. ratios of 1:0.67 and 1:0.5, respectively. At a constant AM:ATPPB wt. ratio of 1:0.67 and 3 kGy, the grafting ratio increased with starch/(AM + ATPPB), while the cationic degree and turbidity reduction simultaneously reached maximum values at a starch:(AM + ATPPB) wt. ratio of 1:2.67. Further study revealed that the higher the absorbed dose or the lower the starch/(AM + ATPPB) ratio, the lower the optimal flocculant concentration. PMID:24185060

Song, Weiqiang; Zhao, Zhiwei; Zheng, Hongjuan; Wang, Gaimin

2013-01-01

443

Color Reproduction with a Smartphone  

ERIC Educational Resources Information Center

The world is full of colors. Most of the colors we see around us can be created on common digital displays simply by superposing light with three different wavelengths. However, no mixture of colors can produce a fully pure color identical to a spectral color. Using a smartphone, students can investigate the main features of primary color addition…

Thoms, Lars-Jochen; Colicchia, Giuseppe; Girwidz, Raimund

2013-01-01

444

Colors Change Appearance Crayola Supplies  

E-print Network

wonder about how your eyes perceive color and shape? Form a question about your experience. Use books color looks different to your eye when surrounded by other colors. Adaptations Older students work students. Find out more about color. Are there colors the human eye does not see? What colors do different

Zanibbi, Richard

445

Effect of additives on physicochemical properties in amorphous starch matrices.  

PubMed

The effect of the addition of non-reducing sugars or methylcellulose on the matrix physical properties and rate of non-enzymatic browning (NBR) between exogenous glucose+lysine in a starch-based glassy matrix were studied, using the methods of luminescence and FTIR. Amorphous starch-based matrices were formulated by rapidly dehydrating potato starch gel mixed with additives at weight ratios of 7:93 (additive:starch). Data on the phosphorescence emission energy and lifetime from erythrosin B dispersed in the matrices indicated that sugars decreased starch matrix mobility in a Tg-dependent manner, except for trehalose that interacted with starch in a unique mode, while methylcellulose, the additive with the highest Tg, increased the molecular mobility. Using FTIR, we found that methylcellulose decreased the strength of hydrogen bond network and sugars enhanced the hydrogen bond strength in the order: trehalose>maltitol>sucrose. Comparing those changes with the rate of NBR between exogenous glucose+lysine, we suggest that NBR rates are primarily influenced by matrix mobility, which is modulated by the hydrogen bond network, and interactions among components. PMID:25308673

Liang, Jun; Wang, Simon; Ludescher, Richard D

2015-03-15

446

Mutants of Arabidopsis with altered regulation of starch degradation  

SciTech Connect

Mutants of Arabidopsis thaliana (L.) Heynh. with altered regulation of starch degradation were identified by screening for plants that retained high levels of leaf starch after a period of extended darkness. The mutant phenotype was also expressed in seeds, flowers, and roots, indicating that the same pathway of starch degradation is used in these tissues. In many respects, the physiological consequences of the mutations were equivalent to the effects observed in previously characterized mutants of Arabidopsis that are unable to synthesize starch. One mutant line, which was characterized in detail, had normal levels of activity of the starch degradative enzymes {alpha}-amylase, {beta}-amylase, phosphorylase, D-enzyme, and debranching enzyme. Thus, it was not possible to establish a biochemical basis for the phenotype, which was due to a recessive mutant at a locus designated sex 1 at position 12.2 on chromosome 1. This raises the possibility that hitherto unidentified factors, altered by the mutation, play a key role in regulating or catalyzing starch degradation.

Caspar, T.; Lin, Tsanpiao; Kakefuda, G.; Benbow, L.; Preiss, J.; Somerville, C. (Michigan State Univ., East Lansing (USA))

1991-04-01

447

Modeling of display color parameters and algorithmic color selection  

NASA Astrophysics Data System (ADS)

An algorithmic approach to color selection, which is based on psychophysical models of color processing, is described. The factors that affect color differentiation, such as wavelength separation, color stimulus size, and brightness adaptation level, are discussed. The use of the CIE system of colorimetry and the CIELUV color difference metric for display color modeling is examined. The computer program combines the selection algorithm with internally derived correction factors for color image field size, ambient lighting characteristics, and anomalous red-green color vision deficiencies of display operators. The performance of the program is evaluated and uniform chromaticity scale diagrams for six-color and seven-color selection problems are provided.

Silverstein, Louis D.; Lepkowski, James S.; Carter, Robert C.; Carter, Ellen C.

1986-01-01

448

Diurnal Changes in the Transcriptome Encoding Enzymes of Starch Metabolism Provide Evidence for Both Transcriptional and Posttranscriptional Regulation of Starch Metabolism in Arabidopsis Leaves1  

Microsoft Academic Search

To gain insight into the synthesis and functions of enzymes of starch metabolism in leaves of Arabidopsis L. Heynth, Affymetrix microarrays were used to analyze the transcriptome throughout the diurnal cycle. Under the conditions employed, transitory leaf starch is degraded progressively during a 12-h dark period, and then accumulates during the following 12-h light period. Transcripts encoding enzymes of starch

Steven M. Smith; Daniel C. Fulton; Tansy Chia; David Thorneycroft; Andrew Chapple; Hannah Dunstan; Christopher Hylton; Samuel C. Zeeman; Alison M. Smith

449

Diurnal Changes in the Transcriptome Encoding Enzymes of Starch Metabolism Provide Evidence for Both Transcriptional and Posttranscriptional Regulation of Starch Metabolism in Arabidopsis Leaves1  

PubMed Central

To gain insight into the synthesis and functions of enzymes of starch metabolism in leaves of Arabidopsis L. Heynth, Affymetrix microarrays were used to analyze the transcriptome throughout the diurnal cycle. Under the conditions employed, transitory leaf starch is degraded progressively during a 12-h dark period, and then accumulates during the following 12-h light period. Transcripts encoding enzymes of starch synthesis changed relatively little in amount over 24 h except for two starch synthases, granule bound starch synthase and starch synthase II, which increased appreciably during the transition from dark to light. The increase in RNA encoding granule-bound starch synthase may reflect the extensive destruction of starch granules in the dark. Transcripts encoding several enzymes putatively involved in starch breakdown showed a coordinated decline in the dark followed by rapid accumulation in the light. Despite marked changes in their transcript levels, the amounts of some enzymes of starch metabolism do not change appreciably through the diurnal cycle. Posttranscriptional regulation is essential in the maintenance of amounts of enzymes and the control of their activities in vivo. Even though the relationships between transcript levels, enzyme activity, and diurnal metabolism of starch metabolism are complex, the presence of some distinctive diurnal patterns of transcripts for enzymes known to be involved in starch metabolism facilitates the identification of other proteins that may participate in this process. PMID:15347792

Smith, Steven M.; Fulton, Daniel C.; Chia, Tansy; Thorneycroft, David; Chapple, Andrew; Dunstan, Hannah; Hylton, Christopher; Zeeman, Samuel C.; Smith, Alison M.

2004-01-01

450

Mutation Spectrum of the 9q34 Tuberous Sclerosis Gene TSC1 in Transitional Cell Carcinoma of the Bladder  

Microsoft Academic Search

Deletions of the long arm of chromosome 9 are the most common genetic alteration in transitional cell carcinoma (TCC) of the bladder. Several regions of deletion on 9q have been mapped by loss of heterozygosity (LOH) analysis, one of which encompasses one of the two loci for tuberous sclerosis, TSC1 ,a t 9q34. Tuberous sclerosis complex (TSC) is an autosomal

Margaret A. Knowles; Tomonori Habuchi; Wendy Kennedy; Darren Cuthbert-Heavens

2003-01-01