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  • 1
    Electronic Resource
    Electronic Resource
    Comparisons of phylogenetic hypotheses among different data sets in dwarf dandelions (Krigia, Asteraceae): Additional information from internal transcribed spacer sequences of nuclear ribosomal DNA (1994)
    Springer
    Plant systematics and evolution 190 (1994), S. 157-185 
    Details
    ISSN: 1615-6110
    Keywords: Asteraceae ; Lactuceae ; Microseridinae ; Krigia ; Internal transcribed spacer (ITS) ; ITS region (ITS 1, 5.8 S rDNA, and ITS 2) ; intergenic spacer (IGS) region ; nuclear ribosomal DNA (nrDNA) ; chloroplast DNA (cpDNA) ; sequence divergence ; polymerase chain reaction (PCR) ; maximum parsimony (MP) tree ; neighbor joining (NJ) tree
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The internal transcribed spacer (ITS) region of the 18 S–25 S nuclear ribosomal DNA repeat was sequenced from 19 populations of the tribeLactuceae, including all species of dwarf dandelion (Krigia) and five outgroup genera. The incidence of length changes and base substitutions was at least two times higher for ITS 1 than ITS 2. Interspecific sequence divergence withinKrigia averaged 9.62% (1.61%–15.19%) and 4.26% (0%–6.64%) in ITS 1 and ITS 2, respectively. Intergeneric sequence divergence ranged from 15.6% to 44.5% in ITS 1 and from 8.0% to 28.6% in ITS 2. High sequence divergence and homoplasy among genera of tribeLactuceae suggest that the phylogenetic utility of ITS sequence data is limited to interspecific studies or comparisons among closely related genera. Trees generated from ITS sequences are essentially identical to those from restriction site comparisons of the entire nuclear ribosomal (nr) DNA region. The degree of tree resolution differed depending on how gaps were treated in phylogenetic analyses. The ITS trees were congruent with the chloroplast DNA and morphological phylogenies in three major ways: 1) the sister group relationship betweenKrigia andPyrrhopappus; 2) the recognition of two monophyletic sections,Krigia andCymbia, in genusKrigia; and 3) the monophyly of theK. occidentalis-K. cespitosa clade in sect.Cymbia. However, the two nrDNA-based trees are not congruent with morphology/chloroplast DNA-based trees for the interspecific relationships in sect.Krigia. An average of 22.5% incongruence was observed among fourKrigia data sets. The relatively high degree of incongruence among data sets is due primarily to conflict between trees based on nrDNA and morphological/cpDNA data. The incongruence is probably due to the concerted evolution of nrDNA repeating units. The results fromKrigia and theLactuceae suggest that nrDNA data may have limited utility in phylogenetic studies of plants, especially in groups which exhibit high levels of sequence divergence. Our combined phylogenetic analysis as a total evidence shows the least conflict to each of the individual data sets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00986191
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  • 2
    Electronic Resource
    Electronic Resource
    Phylogenetic and evolutionary implications of nuclear ribosomal DNA variation in dwarf dandelions (Krigia, Lactuceae, Asteraceae) (1991)
    Springer
    Plant systematics and evolution 177 (1991), S. 53-69 
    Details
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Lactuceae ; Krigia ; Nuclear ribosomal DNA (nrDNA) ; inter-cistronic spacer (ITS) ; intergenic spacer (IGS) ; subrepeating unit ; chloroplast DNA (cpDNA) ; allopolyploid ; restriction site mapping ; methylation ; bootstrap resampling analysis ; sequence divergence value ; cladistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Restriction site and length variations of nrDNA were examined for 51 populations of seven species ofKrigia. The nrDNA repeat ranged in size from 8.7 to 9.6 kilobase (kb). The transcribed region, including the two ITSs, was 5.35 kb long in all examinedKrigia populations. In contrast, the size of the nontranscribed IGS varied from 3.35 to 4.25 kb. Eight different types of length-variations were identified among the 51 populations, including distinct nrDNA lengths in the tetraploid and diploid populations of bothK. biflora andK. virginica. However, a few variations were detected among populations of the same species or within a cytotype. All populations ofKrigia sect.Cymbia share a 600 bp insertion in IGS near the 18 S gene, and this feature suggests monophyly of the section. AllKrigia spp. had a conjugated type of subrepeat composed of approximately 75 basepairs (bp) and 125 bp. Base modifications in the gene coding regions were highly conserved among species. Forty-five restriction sites from 15 enzymes were mapped, 24 of which were variable among populations. Only four of the variable sites occurred in the rRNA coding region while 20 variable sites were detected in the noncoding regions. Collectively, 25 enzymes generated about 66 restriction sites in each nrDNA; this amounts to about 4.3% of the nrDNA repeat. A total of 50 restriction sites was variable, 28 of which were phylogenetically informative. Phylogenetic analyses of site mutations indicated that two sections ofKrigia, sect.Cymbia and sect.Krigia, are monophyletic. In addition, relationships among several species were congruent with other sources of data, such as cpDNA restriction site variation and morphology. Both length and restriction site variation supported an allopolyploid origin of the hexaploidK. montana. The average sequence divergence value inKrigia nrDNA was 40 times greater than that of the chloroplast DNA. The rapid evolution of nrDNA sequences was primarily due to changes of the IGS sequences.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00937826
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  • 3
    Electronic Resource
    Electronic Resource
    Simultaneous determination of parathion and metabolites in serum by HPLC with column switching (1997)
    Springer
    Chromatographia 44 (1997), S. 473-476 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Column-switching ; Parathion, and metabolites in serum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new high-performance liquid chromatographic method with column-switching has been developed for the simultaneous determination of parathion and its metabolites such asp-nitrophenol and paraoxon in serum. Serum samples were injected onto a precolumn packed with LiChroprep RP-8 after simple dilution with 20% phosphoric acid. Polar plasma components were washed with 0.02 M phosphate buffer (pH 3.0). After valve switching, the concentrated compounds were eluted in back-flush mode and separated on a Ultracarb ODS 30 column with a gradient of acetonitrile −0.01 M phosphate buffer (pH 3.0) as mobile phase. The method showed excellent precision, accuracy and speed with detection limit of 0.1 μg mL−1. Total analysis time per sample was 〈40 min and coefficients of variation for intra-and inter-assay were 〈4.5%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02466739
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  • 4
    Electronic Resource
    Electronic Resource
    Determination of myristicin in rat serum samples using microbore high performance liquid chromatography with column-switching (1998)
    Springer
    Chromatographia 48 (1998), S. 365-368 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Microbore columns ; Column-switching ; Myristicin ; Serum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A microbore high-performance liquid chromatographic method with column-switching was developed for the analysis of myristicin from rat serum without prepurification. Deproteinization, fractionation, concentration and separation of analyte were carried out by appropriate switching of columns and using solvent mixtures. The method showed excellent precision, accuracy and speed with a detection limit of 10 ng mL−1 from 25 μL of serum. The total analysis time per sample was 25 min and the coefficients of variation for intra- and inter-assay were less than 1.8%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467705
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  • 5
    Electronic Resource
    Electronic Resource
    Some factors determining protein aggregation during ultrafiltration (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 260-265 
    Details
    ISSN: 0006-3592
    Keywords: fouling ; ultrafiltration ; protein aggregates ; field emission scanning electron microscopy (FESEM) ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The factors contributing to protein aggregation in albumin ultrafiltration were investigated as a function of operation conditions. The nature of protein deposits was examined by electron microscopy. Protein aggregation appears to occur as a result of rapid supersaturation of protein molecules and high solvent velocity (shear) in the concentrated layer near the membrane surface. The shear occurring in the solvent flow on the membrane surface probably unfolds protein molecules and thus promotes flocculation due to collision between particles. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420216
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of membrane morphology and operation on protein deposition in ultrafiltration membranes (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 47 (1995), S. 174-180 
    Details
    ISSN: 0006-3592
    Keywords: ultrafiltration membranes ; protein fouling ; BET measurements ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Membrane morphology is compared to protein depostion under passive adsorption and ultrafiltration conditions. Solute resistance of protein deposits for membranes of varying roughness, structure, and permeability can vary dramatically with operating conditions. Using Brunauer-Emmett-Teller adsorption isotherm (BET), study of the internal area and accessibility of several uttrafiltration membranes to protein deposition allows better understanding of the fouling mechanisms and interpretation of adsorbed protein quantities. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260470208
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  • 7
    Electronic Resource
    Electronic Resource
    Acid hydrolysis of sweet potato for ethanol production (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 316-320 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Studies were conducted to establish optimal conditions for the acid hydrolysis of sweet potato for maximal ethanol yield. The starch contents of two sweet potato cultivars (Georgia Red and TG-4), based on fresh weight, were 21.1 ± 0.6% and 27.5 ± 1.6%, respectively. The results of acid hydrolysis experiments showed the following: (1) both hydrolysis rate and hydroxymethylfurfural (HMF) concentration were a function of HCL concentration, temperature, and time; (2) the reducing sugars were rapidly formed with elevated concentrations of HCl and temperature, but also destroyed quickly; and (3) HMF concentration increased significantly with the concentration of HCl, temperature, and hydrolysis time.Maximum reducing sugar value of 84.2 DE and 0.056% HMF (based on wet weight) was achieved after heating 8% SPS for 15 min in 1N HCl at 110°C. Degraded 8% SPS (1N HCl, 97°C for 20 min or 110°C for 10 min) was utilized as substrate for ethanol fermentation and 3.8% ethanol (v/v) was produced from 1400 mL fermented wort. This is equal to 41.6 g ethanol (200 proof) from 400 g of fresh sweet potato tuber (Georgia Red) or an ethanol yield potential of 431 gal of 200-proof ethanol/acre (from 500 bushel tubers/acre).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260270316
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  • 8
    Electronic Resource
    Electronic Resource
    Acid hydrolysis of Jerusalem artichoke for ethanol fermentation (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 138-141 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260280124
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