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  • Evolution  (47)
  • oxidation  (47)
  • Springer  (94)
  • American Meteorological Society
  • 1995-1999  (94)
  • 1970-1974
  • 1999  (94)
Collection
Keywords
Publisher
  • Springer  (94)
  • American Meteorological Society
Years
  • 1995-1999  (94)
  • 1970-1974
Year
  • 1
    Electronic Resource
    Electronic Resource
    Factors affecting bioleaching kinetics of sulfide ores using acidophilic micro-organisms (1999)
    Springer
    BioMetals 12 (1999), S. 1-10 
    Details
    ISSN: 1572-8773
    Keywords: acidophilic ; strain ; oxidation ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Recovery of metal values from sulfide ores by use of acidophilic microorganisms is gaining importance. A number of commercial/pilot plants are setup to find out the techno-economic feasibility of the overall process. The main drawback in the process is the slow kinetics of dissolution of metal values from the sulfide ores. To make the technology e attractive the kinetics should be improved considerably. There are various factors which determine the overall kinetics such as bacterial activity and concentration, iron and sulfur oxidation, oxygen consumption, reactor design and nature of ore. A brief review has been made dealing with the above parameters
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009228210654
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  • 2
    Electronic Resource
    Electronic Resource
    Alkene selectivity enhancement in the oxidation of propane on calcium-based catalysts (1999)
    Springer
    Catalysis letters 59 (1999), S. 67-72 
    Details
    ISSN: 1572-879X
    Keywords: propane ; oxidation ; calcium-based catalysts ; tetrachloromethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation of propane has been investigated in the presence and absence of tetrachloromethane (TCM) on calcium hydroxyapatite (CaHAp), Ca3(PO4)2, CaSO4 and CaO at 723 K. In the absence of TCM, the conversion of C3H8 on CaHAp was 7.7–9.2% during 6 h on-stream while that on Ca3(PO4)2, CaSO4 and CaO was 0.6, 0 and 0.2–0.4%, respectively. The principal products on all catalysts in the absence of TCM were CO and CO2 with small selectivities to C3H6 and C2H4 (both 5–6%) observed on CaHAp. Upon addition of TCM, the selectivity to C3H6 on all catalysts and the conversion of C3H8 on CaSO4 increased while, with increasing time-on-stream, the changes in the conversion and selectivity were dependent upon the nature of the catalysts. XPS and XRD analyses provide evidence for the presence of chlorine in the surface and/or bulk of three of the catalysts, suggesting that chlorinated species on the solids play a role in the selectivity enhancement, but the absence of chlorine from the sulphate demonstrates the dissimilarities of the catalysts in their abilities to sorb and decompose TCM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019091731368
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  • 3
    Electronic Resource
    Electronic Resource
    Synergistic effects in the oxidation of methane on strontium and lead hydroxyapatites (1999)
    Springer
    Catalysis letters 57 (1999), S. 161-165 
    Details
    ISSN: 1572-879X
    Keywords: methane ; oxidation ; strontium hydroxyapatite ; lead hydroxyapatite ; tetrachloromethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation of methane has been investigated on lead hydroxyapatite (PbHAp), strontium hydroxyapatite (SrHAp) and their binary mixtures at 873 K. PbHAp showed no activity for the oxidation of methane, while SrHAp produced carbon monoxide selectively at 2–4% conversion. On binary mixtures of the hydroxyapatites the conversion of methane and the selectivity to C2 compounds reached values higher than those of the separate constituents of the mixture. With tetrachloromethane in the feed stream a similar synergistic effect was observed with conversions of methane and selectivities to CH3Cl higher on the binary mixtures than those on either SrHAp or PbHAp. The strontium-containing hydroxyapatite appears to play a crucial role in the activation of methane, while the presence of the lead-containing analogue is apparently required for the minimization of undesirable processes involving methyl radicals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019024421857
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  • 4
    Electronic Resource
    Electronic Resource
    A new process for acetic acid production by direct oxidation of ethylene (1999)
    Springer
    Catalysis surveys from Japan 3 (1999), S. 55-60 
    Details
    ISSN: 1572-8803
    Keywords: acetic acid ; oxidation ; Pd ; heteropoly acid ; ethylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new process for acetic acid production by direct oxidation of ethylene which was established and commercialized is described. The catalyst system consisting of Pd and heteropoly acid exhibits excellent activity and selectivity. The addition of Se or Te to the catalyst system is effective to suppress the formation of carbon dioxide. This new process is applicable to a plant of a wide range of size corresponding to the local demand. Because this new process produces little waste water, it is very friendly to the environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019003230537
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  • 5
    Electronic Resource
    Electronic Resource
    Purification and characterization of an ADP-dependent phosphofructokinase from Thermococcus zilligii (1999)
    Springer
    Extremophiles 3 (1999), S. 121-129 
    Details
    ISSN: 1433-4909
    Keywords: Key words Thermococcus ; Pyrococcus ; Thermophilic ; Phosphofructokinase ; Evolution ; ADP ; Glycolysis ; ATP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ADP-dependent phosphofructokinase (PFK) from Thermococcus zilligii has been purified 950 fold; it had a specific activity of 190 U mg−1. The enzyme required Mg2+ ions for optimal activity and was specific for ADP. The forward reaction kinetics were hyperbolic for both cosubstrates (pH optimum of 6.4), and the apparent K m values for ADP and fructose-6-phosphate were 0.6 mM (apparent V max of 243 U mg−1) and 1.47 mM (apparent V max of 197 U mg−1), respectively. Significantly, the enzyme is indicated to be nonallosteric but was slightly activated by some monovalent cations including Na+ and K+. The protein had a subunit size of 42.2 kDa and an estimated native molecular weight of 66 kDa (gel filtration). Maximal reaction rates for the reverse reaction were attained at pH 7.5–8.0, and the apparent K m values for fructose-1,6-bisphosphate and AMP were 0.56 mM (apparent V max of 2.9 U mg−1) and 12.5 mM, respectively. The biochemical characteristics of this unique ADP-dependent enzymatic activity are compared to ATP and pyrophosphate-dependent phosphofructokinases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007920050107
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  • 6
    Electronic Resource
    Electronic Resource
    Isolation of a chymotrypsinogen B-like enzyme from the archaeon Natronomonas pharaonis and other halobacteria (1999)
    Springer
    Extremophiles 3 (1999), S. 153-161 
    Details
    ISSN: 1433-4909
    Keywords: Key wordsNatronomonas pharaonis ; Natronobacteria ; Archaea ; Serine protease ; Chymotrypsinogen ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A protease of a molecular mass of approximately 30 kDa was isolated and purified from the haloalkaliphilic archaeon Natronomonas (formerly Natronobacterium) pharaonis. The enzyme hydrolyzed synthetic peptides, preferentially at the carboxyl terminus of phenylalanine or leucine, as well as large proteins. Hydrolysis occurred over the range of pH from 6 to 12, with an optimum at pH 10. The temperature optimum was 61°C. The enzyme was nearly equally active over the range of salt concentration from 0.5 to 4 M (NaCl or KCl). A strong cross-reaction with a polyclonal antiserum against human chymotrypsin was observed. Enzymatic activity was inhibited by typical serine protease inhibitors. There was significant homology between N-terminal and internal sequences from autolytic fragments and the sequence of bovine chymotrypsinogen B; the overall amino acid composition was similar to that of vertebrate chymotrypsinogens. Evidence for a zymogen-like processing of the protease was obtained. Cell extracts from other halobacteria exhibited similar proteolytic activity and immunoreactivity. The data suggested a widespread distribution of a chymotrypsinogen B-like protease among halo- and haloalkaliphilic Archaea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007920050111
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  • 7
    Electronic Resource
    Electronic Resource
    A study of “superacidic” MoO3/ZrO2 catalysts for methane oxidation (1999)
    Springer
    Catalysis letters 57 (1999), S. 109-113 
    Details
    ISSN: 1572-879X
    Keywords: superacid ; zirconia ; molybdenum oxide ; methane ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of zirconia-supported molybdenum oxide catalysts with different molybdenum loadings prepared using conditions reported to generate “superacidity” have been evaluated for their performance as catalysts for methane oxidation. A marked dependence of Mo content on activity has been observed, with the most active material being that with intermediate molybdenum content. 5 wt% MoO3/ZrO2 compares favourably with ZrxCe1-xO2 for methane combustion. The presence of MoO3 is observed to stabilise the tetragonal polymorph of ZrO2 and, as Mo content is increased, dispersed MoO3 crystallites are formed as evidenced by Raman spectroscopy. Temperature-programmed reduction studies evidence differences in the reduction behaviour of the materials as a function of loading. The results indicate that molybdenum oxide supported on monoclinic zirconia gives rise to the most active catalyst. It is tentatively suggested that the formation of a MoO3 monolayer during reaction may be of importance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019047632335
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  • 8
    Electronic Resource
    Electronic Resource
    A new strategy for alkane oxidation with O2 using N‐hydroxyphthalimide (NHPI) as a radical catalyst (1999)
    Springer
    Catalysis surveys from Japan 3 (1999), S. 27-35 
    Details
    ISSN: 1572-8803
    Keywords: oxidation ; oxygen ; alkane ; N‐hydroxyphthalimide ; radical catalyst
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A practical catalytic method to convert alkanes into the corresponding oxygen‐containing compounds with O2 under mild conditions using N‐hydroxyphthalimide (NHPI) in the presence or absence of a transition metal was developed. Thus, cyclohexane was successfully converted into adipic acid in good conversion and selectivity by a combined catalytic system consisting of NHPI and Mn(acac)2. Lower alkane such as isobutane was converted into t‐butyl alcohol (83%) under 10 atm of air by NHPI‐Co(OAc)2 system. Alkylbenzene such as toluene was oxidized to benzoic acid in high yield (81%) under normal temperature and pressure of dioxygen in the presence of a catalytic amount of NHPI and Co(OAc)2. ESR measurements showed that phthalimide‐N‐oxyl generated from NHPI under dioxygen atmosphere is a key species in this oxidation and functions as a radical catalyst.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019059315516
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  • 9
    Electronic Resource
    Electronic Resource
    Multiple class I loci expressed by the quail Mhc (1999)
    Springer
    Immunogenetics 49 (1999), S. 456-460 
    Details
    ISSN: 1432-1211
    Keywords: Key words Antigen processing ; Evolution ; Cell surface molecules ; Mhc ; Class I antigens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050519
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  • 10
    Electronic Resource
    Electronic Resource
    Identification and characterization of a fish natural resistance-associated macrophage protein (NRAMP) cDNA (1999)
    Springer
    Immunogenetics 50 (1999), S. 60-66 
    Details
    ISSN: 1432-1211
    Keywords: Key words NRAMP ; Fish ; Carp ; Evolution ; Expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The mouse Lsh/Ity/Bcg locus regulates natural resistance to intracellular pathogens, and the Nramp1 gene was isolated as its candidate. Nramp is part of a small family of at least two genes, Nramp1 and Nramp2. In the present study, a full-length cDNA for carp NRAMP has been isolated and characterized. Nucleotide and predicted amino acid sequence analysis indicate that the carp NRAMP encodes a 548 amino acid membrane protein with 12 putative transmembrane domains, two N-linked glycosylation sites, and an evolutionarily conserved consensus transport motif. The peptide sequence identity among carp and human NRAMP2 is 78%, and 65% with human NRAMP1. Reverse transcription-polymerase chain reaction revealed that carp NRAMP is ubiquitously expressed. Phylogenetic analysis, using neigbor-joining, showed that the carp NRAMP protein clustered together with mammalian NRAMP2 proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050686
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  • 11
    Electronic Resource
    Electronic Resource
    Diversity and evolution of T-cell receptor variable region genes in mammals and birds (1999)
    Springer
    Immunogenetics 50 (1999), S. 301-308 
    Details
    ISSN: 1432-1211
    Keywords: Key words T-cell receptors ; Variable region genes ; Evolution ; Phylogeny ; Diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The receptor of a T lymphocyte (TCR) recognizes nonself antigens in the company of major histocompatibility complex (MHC) molecules presented to it by the antigen-presenting cell. The variable region of TCR is encoded by either a concatenation of variable region (TCR-V), diversity region (TCR-D), and joining region (TCR-J) genes, or a concatenation of TCR-V and TCR-J genes. The TCR-V genes exist as a multigene family in vertebrate species. Here we study the evolutionary relationships of TCR-V genes from humans, sheep, cattle, rabbits, mice, and chicken. These six species can be classified into two groups according to the frequency of γδ T-cells in their peripheral T-cell populations. The "γδ low" group of species includes humans and mice, in which γδ T-cells constitute very limited portion of the T-cell population. The "γδ high" group includes sheep, cattle, rabbits, and chicken, in which γδ T-cells comprise up to 60% of the T-cell population. Here, we compiled TCR-V sequences from the six species and conducted a phylogenetic analysis. We identified various TCR-V gene subgroups based on the analysis. We found that humans and mice have representatives from nearly all of the subgroups identified, while other species have lost subgroups to different extent. Therefore, the γδ low species have a high degree of diversity of TCR-V genes, while γδ high species all have limited diversity of TCR-V genes. This pattern is similar to that found for immunoglobulin variable region (IGV) genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050606
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  • 12
    Electronic Resource
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    Marsupial light chains: IGK with four V families in the opossum Monodelphis domestica (1999)
    Springer
    Immunogenetics 50 (1999), S. 329-335 
    Details
    ISSN: 1432-1211
    Keywords: Key words Marsupials ; Light chains ; Variable regions ; IGK ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A full-length and several partial cDNAs encoding IGK light chains from the marsupial South American opossum, Monodelphis domestica, were isolated and characterized. Using these clones as a starting point, the expressed IGKV repertoire was sampled by anchored polymerase chain reaction using an IGKC-specific primer. Based on nucleotide sequences of twenty unique, expressed IGKV-J combinations, there are at least four IGKV families and two J segments. Southern blot analysis revealed each IGK-V family contains multiple gene segments totaling at least thirty-five IGKV in the opossum genome. No evidence for particular, recurrent IGKV-J combinations in the opossum IGK repertoire was seen, rather the V-J combinations appeared random and diverse. Each of the four IGKV families appear more closely related to V segments from placental mammals than to each other, suggesting the duplication of the IGKV families prior to the separation of marsupials and placental mammals more than one-hundred-million years ago. Overall, the complexity of opossum light chain V segments appears greater than that found in the heavy chain, and light chains are likely to contribute significantly to Ig diversity in this species.With this report, the homologues encoding all three classes of eutherian Ig chains, IGH, IGL, and IGK, have been described in a non-placental mammal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050609
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  • 13
    Electronic Resource
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    Major histocompatibility complex-linked MIC genes in rhesus macaques and other primates (1999)
    Springer
    Immunogenetics 50 (1999), S. 358-362 
    Details
    ISSN: 1432-1211
    Keywords: Key words MHC ; MIC ; Nonhuman primates ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050614
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  • 14
    Electronic Resource
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    Isolation and mapping of the rabbit DM genes (1999)
    Springer
    Immunogenetics 49 (1999), S. 295-302 
    Details
    ISSN: 1432-1211
    Keywords: Key words Major histocompatibility complex ; Class II ; Antigen processing ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Proper peptide presentation by major histocompatibility complex (MHC)-encoded class II antigens is dependent on the products of the MHC DM loci. We identified the rabbit orthologues (RLA-DMA and -DMB) of human HLA-DMA and -DMB and found that they have 76.9% and 78.8% identity with HLA-DMA and -DMB, respectively. Like classical class II MHC genes, RLA-DM genes are more closely related to human HLA-DM genes than to mouse H2-DM. Among the DM family, there is a high degree of variability at the amino terminus of the DMa chains, and length variability in the cytoplasmic tails of both DMα and DMβ. The rabbit DM genes are coexpressed with class II genes in lymphoid tissues, as are the DM genes of other mammals. The RLA-DM locus maps to the class II region of the rabbit MHC, and is flanked by the DP and DOB loci. Despite having some similarities to class II genes of bony fishes, the DM family represents a separate branch of the MHC class II family.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050496
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  • 15
    Electronic Resource
    Electronic Resource
    New family of Mhc class II A genes identified from cDNA sequences in the cichlid fish Aulonocara hansbaenschi (1999)
    Springer
    Immunogenetics 49 (1999), S. 544-548 
    Details
    ISSN: 1432-1211
    Keywords: Key words Mhc ; Class II A ; Cichlid ; Fish ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050533
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  • 16
    Electronic Resource
    Electronic Resource
    Characterization of beta2-microglobulin in a primitive fish, the Siberian sturgeon (Acipenser baeri) (1999)
    Springer
    Immunogenetics 50 (1999), S. 79-83 
    Details
    ISSN: 1432-1211
    Keywords: Key words Beta2-microglobulin ; Evolution ; Sturgeon ; cDNA ; Genomic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050690
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  • 17
    Electronic Resource
    Electronic Resource
    A nose that looks like a hand and acts like an eye: the unusual mechanosensory system of the star-nosed mole (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 367-372 
    Details
    ISSN: 1432-1351
    Keywords: Key words Cortical magnification ; Somatosensory cortex ; Development ; Evolution ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The star-nosed mole (Condylura cristata) has a snout surrounded by 22 fleshy and mobile appendages. This unusual structure is not an olfactory organ, as might be assumed from its location, nor is it used to manipulate objects as might be guessed from its appearance. Rather, the star is devoted to the sense of touch, and for this purpose the appendages are covered with thousands of small mechanoreceptive Eimer's organs. Recent behavioral studies find that the star acts much like a tactile eye, having a small behavioral focus, or “fovea” at the center – used for detailed explorations of objects of interest. The peripheral and central nervous systems of the mole reflect these behavioral specializations, such that the small behavioral focus on the nose is more densely innervated in the periphery, and has a greatly enlarged representation in the somatosensory cortex. This somatosensory representation of the tactile fovea is not correlated with anatomical parameters (innervation density) as found in other species, but rather is highly correlated with patterns of behavior. The many surprising parallels between the somatosensory system of the mole, and the visual systems of other mammals, suggest a convergent and perhaps common organization for highly developed sensory systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050396
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  • 18
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    Peripheral frequency mis-match in the primitive ensiferan Cyphoderris monstrosa (Orthoptera: Haglidae) (1999)
    Springer
    Journal of comparative physiology 184 (1999), S. 543-551 
    Details
    ISSN: 1432-1351
    Keywords: Key words Auditory physiology ; Insect ; Frequency discrimination ; Evolution ; Song recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Peripheral auditory frequency tuning in the ensiferan insect Cyphoderris monstrosa (Orthoptera: Haglidae) was examined by comparing tympanal vibrations and primary auditory receptor responses. In this species there is a mis-match between the frequency of maximal auditory sensitivity and the frequency content of the species' acoustic signals. The mis-match is not a function of the mechanical properties of the tympanum, but is evident at the level of primary receptors. There are two classes of primary receptors: low-tuned and broadly tuned. Differences in the absolute sensitivity of the two receptor types at the male song frequency would allow the auditory system to discriminate intraspecific signals from sounds containing lower frequencies. Comparisons of tympanal and receptor tuning indicated that the sensitivity of the broadly tuned receptors did not differ from that of the tympanum, while low-tuned receptors had significantly narrower frequency tuning. The results suggest that the limited specialization for the encoding of intraspecific signals in the auditory system of C. monstrosa is a primitive rather than a degenerate condition. The limited specialization of C. monstrosa may reflect the evolutionary origin of communication-related hearing from a generalized precursor through the addition of peripheral adaptations (tympana, additional receptors) to enhance frequency sensitivity and discrimination.
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    URL: http://dx.doi.org/10.1007/s003590050354
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  • 19
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    Comparison of morphology and physiology of two plurisegmental sound-activated interneurones in a bushcricket (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 199-205 
    Details
    ISSN: 1432-1351
    Keywords: Key words Hearing ; Orthoptera ; Phaneropteridae ; Cercal system ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The unusual morphology of a sound-activated plurisegmental ascending interneurone (AN5-AG7) in an insect (Ancistrura nigrovittata, Ensifera, Phaneropteridae) is described. This neurone's soma is located in the penultimate abdominal ganglion. The most prominent arborisations with smooth endings are found in the prothoracic ganglion. The neurone terminates with numerous beaded endings in the brain (protocerebrum). All abdominal ganglia including the penultimate contain only tiny side branches of beaded appearance. The neurone's morphology is compared to the morphology of a `typical' sound-activated plurisegmental neurone of bushcrickets with its soma in the prothorax. In the prothoracic ganglion and in the brain the arborisations of the two cells are very similar. Graded potentials and action potentials are generated in the prothoracic portion of both neurones. Both receive excitation mainly by ultrasound, and inhibition by soma-ipsilateral stimuli. Neither wind, substrate vibration nor touch of the abdomen evoke responses in AN5-AG7. It is assumed that early in evolution this neurone had its dendrites in the ganglion which houses the cell body (like cercal interneurones of this neuromere). Profound evolutionary changes probably have taken place to bring about this neuron's modern morphology.
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    URL: http://dx.doi.org/10.1007/s003590050378
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  • 20
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    Spatial discrimination of pheromones and behavioural antagonists by the tortricid moths Cydia pomonella and Adoxophyes orana (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 419-425 
    Details
    ISSN: 1432-1351
    Keywords: Key wordsCydia pomonella ; Adoxophyes orana ; Sex pheromone ; Interspecific interruption ; Evolution ; AbbreviationsZ9-14:Ac (Z9)-tetradecenylacetate Z11-14:Ac (Z11)-tetradecenylacetate ; E8, E10-12:OH (E8, E10)-dodecadienol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Male moths responding to their species-specific sex pheromone, may cease their upwind flight when pheromone components of sympatric species are added to the mixture. The interspecific interaction between the pheromone response of the tortricid moths Cydia pomonella and Adoxophyes orana was investigated in field-trapping and wind-tunnel studies. Addition of the A. orana pheromone [(Z9)-tetradecenylacetate and (Z11)-tetradecenylacetate] to a source containing the C. pomonella pheromone [(E8, E10)-dodecadienol] resulted in a significant inhibition of attraction by male C. pomonella. It is demonstrated that this behavioural antagonist for C. pomonella must be emitted from the same point source to induce this inhibitory effect. A spatial separation of the two interspecific pheromones (at 14 cm, 5 cm and 0.5 cm crosswind) restored the attraction of the conspecific pheromone for male C. pomonella. In contrast to C. pomonella, male A. orana were not inhibited by point sources releasing both the C. pomonella and A. orana pheromone. We suggest that the discrepancy in the interspecific pheromone interaction between these two tortricids can be explained if we consider the evolutionary ecology of interspecific pheromone communication in C. pomonella and A. orana.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050402
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  • 21
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    Electrochemical oxidation of a carbon black loaded polymer electrode in aqueous electrolytes (1999)
    Springer
    Journal of solid state electrochemistry 3 (1999), S. 179-186 
    Details
    ISSN: 1433-0768
    Keywords: Key words Cathodic protection system ; Carbon ; oxidation ; Composite carbon/polymer anode ; Lifetime
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The suitability of a polymeric composite material for use as part of an anode structure in a cathodic protection system has been examined. The composite material was a conductive blend (volume resistivity typically 1.5 Ω cm) of carbon black in a polyethylene binder. A long operational lifetime for the material demands that the rate of carbon loss must be low. In the work reported here, electrochemical and in situ analytical techniques were employed to characterise the performance of the material over a wide range of anodic current densities in a variety of aqueous electrolytes. The predominant anodic electrochemical reaction on the polymeric material is CO2 formation in acid and neutral solutions, which causes loss of carbon from the surface and the development of a non-conducting layer of polyethylene. The characteristics of the reaction suggest that it occurs via the discharge of H2O. In alkaline pH, however, the anodic reactions are more complex. A high OH− concentration (pH 12 or higher) favours the formation of oxygen rather than CO2, particularly at low anodic potentials. The presence of CO3 2− in the electrolyte catalyses the evolution of oxygen at pH values as low as 9. The electrochemical formation of oxygen always occurs in parallel with the generation of some humic acid in the solution.
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    Risk and evolution (1999)
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    Economic theory 13 (1999), S. 329-343 
    Details
    ISSN: 1432-0479
    Keywords: Keywords and Phrases: Risk ; Evolution ; Entrepreneur. ; JEL Classification Numbers: C72 ; D81.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Summary. I examine a Knightian (1921) model of risk using a general equilibrium model of investment and trade. A population of agents with various preference types can choose between a safe production technology and a risky production technology. In addition, the distribution of types of agents changes through a standard evolutionary dynamic. For a given population distribution, the equilibrium is in general inefficient, however, by allowing the population distribution to change in response to market generated rewards, the population will converge to one where the equilibrium is efficient and where the population as a whole behaves as if all agents were risk neutral.
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    Evolution of groundwater chemical composition under human activity in an oilfield (1999)
    Springer
    Environmental geology 38 (1999), S. 34-46 
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    ISSN: 1432-0495
    Keywords: Key words Alkaline/acid/neutral water ; Acid rain ; Geochemical modeling ; Brine ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Analysis and hydrogeochemical modeling of hydrocarbonate groundwater, including its buffering geochemical properties, have demonstrated that this water has undergone a geochemical transformation almost throughout the whole of one industrial region. It is known that hydrocarbonate groundwater possesses a high protective natural geochemical potential, supporting neutralization of acid atmospheric precipitation. Natural hydrocarbonate water undergoes three stages of anthropogenic transformation caused by acid atmospheric precipitation over more than 50 years. The first stage is transformation of neutral hydrocarbonate water into alkaline water, accompanied by calcite precipitation and sodium carbonate dissolution from the unsaturated zone. The second stage is transformation of alkaline water into neutral hydrocarbonate water; the hydrocarbonate content, being less than the lower limit for background concentrations, showed reduced water buffering properties or protective potential relative to acid precipitation. The third stage is transformation of neutral hydrocarbonate water into acidic water, with a complete loss of protective geochemical potential. This unfavorable ecological situation with natural geochemically hydrocarbonate groundwater shows that natural groundwater less protected from the impact of acid atmospheric precipitation is in a worse ecological condition, which is confirmed by observations in northern and Western Europe and other regions of the world.
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    Evolution of homeobox genes: Q50 Paired-like genes founded the Paired class (1999)
    Springer
    Development genes and evolution 209 (1999), S. 186-197 
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    ISSN: 1432-041X
    Keywords: Key words Cnidaria ; Paired class ; Paired-like ; Homeobox gene ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The genes belonging to the Paired class exert primary developmental functions. They are characterized by six invariant amino acid residues in the homeodomain, while the residue at position 50 can be a serine, glutamine or lysine as in the Pax-type, Q50 Paired-like or the K50 Paired-like homeodomains respectively. Genes in this class emerged early in animal evolution: three distinct Pax genes and two Q50 Paired-like genes have recently been characterised from cnidarians. Phylogenetic molecular reconstructions taking into account homeodomain and paired-domain sequences provide some new perspectives on the evolution of the Paired-class genes. Analysis of 146 Paired-class homeodomains from a wide range of metazoan taxa allowed us to identify 18 families among the three sub-classes from which the aristaless family displays the least diverged position. Both Pax-type and K50 families branch within the Q50 Paired-like sequences implying that these are the most ancestral. Consequently, most Pax genes arose from a Paired-like ancestor, via fusion of a Paired-like homebox gene with a gene encoding only a paired domain; the Cnidaria appear to contain genes representing the ’before’ and ’after’ fusion events.
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    Rapid divergence in the course of Drosophila evolution reveals structural important domains of the Notch antagonist Hairless (1999)
    Springer
    Development genes and evolution 209 (1999), S. 155-164 
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    ISSN: 1432-041X
    Keywords: Key words Notch pathway ; Antagonist ; Hairless ; Orthologue ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Hairless is a member of the Notch signalling pathway, where it acts as antagonist by binding to Suppressor of Hairless [Su(H)], thereby inhibiting Notch target gene activation. The pathway and its members are highly conserved in metazoans from worms to humans. However, a Hairless orthologue from another species has not yet been identified. The identification of Hairless in largely diverged species by cross-hybridization has failed so far probably due to a low degree of conservation. Therefore, we turned to D. hydei where a Hairless mutation has been described before. The D. hydei Hairless orthologue is reasonably well conserved with regard to gene structure and expression. The prospective Hairless protein orthologues share several highly conserved regions which are separated by quite diverged stretches. As to be expected, the largest region of high conservation corresponds to the Su(H) binding domain. This region is also functionally conserved, since this D. hydei protein domain binds very strongly to the D. melanogaster Su(H) protein. The other conserved regions support our earlier structure-function analysis since they nicely correspond to previously defined, functionally important protein domains. Most notably, the very C-terminal domain which is very sensitive to structural alterations, is nearly identical between the two species. In summary, this evolutionary study improves the knowledge on functionally significant domains of the Hairless protein, and may be helpful for the future identification of homologues in other animals, especially in vertebrates.
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    Maternal factors and the evolution of developmental mode: Evolution of oogenesis in Heliocidaris erythrogramma (1999)
    Springer
    Development genes and evolution 209 (1999), S. 275-283 
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    ISSN: 1432-041X
    Keywords: Key words Echinoid ; Oogenesis ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Evolutionary change in developmental mode in sea urchins is closely tied to an increase in maternal provisioning. We examined the oogenic modifications involved in production of a large egg by comparison of oogenesis in congeneric sea urchins with markedly different sized oocytes and divergent modes of development. Heliocidaris tuberculata has small eggs (95 µm diameter) and the ancestral mode of development through feeding larvae, whereas H. erythrogramma has large eggs (430 µm diameter) and highly modified non-feeding lecithotrophic larvae. Production of a large egg in H. erythrogramma involved both conserved and divergent mechanisms. The pattern and level of vitellogenin gene expression is similar in the two species. Vitellogenin processing is also similar with the gonads of both species incorporating yolk protein from coelomic and hemal stores into nutritive cells with subsequent transfer of this protein into yolk granules in the developing vitellogenic oocyte. Immunocytology of the eggs of both Heliocidaris species indicates they incorporate similar levels of yolk protein. However, H. erythrogramma has evolved a highly divergent second phase of oogenesis characterised by massive deposition of non-vitellogenic material including additional maternal protein and lipid. Maternal provisioning in H. erythrogramma exhibits recapitulation of the ancestral vitellogenic program followed by a novel oogenic phase with hypertrophy of the lipogenic program being a major contributor to the increase in egg size.
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    Identification and genetic mapping of Xenopus TAP2 genes (1999)
    Springer
    Immunogenetics 49 (1999), S. 171-182 
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    ISSN: 1432-1211
    Keywords: Key words MHC ; Transporter ; Evolution ; PCR cloning ; Allelic lineage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The amphibian Xenopus laevis is one non-mammalian vertebrate in which the major histocompatibility complex (MHC) has been analyzed extensively. Class IIβ, class Ia, LMP2, LMP7, HSP70, C4, Factor B, and Ring3 genes have been identified and mapped to the MHC. Here, we report the isolation of a transporter associated with antigen processing (TAP) gene, TAP2, and demonstrate its linkage to the MHC. While the ATP-binding region of Xenopus TAP2 is highly conserved in evolution, amino acid identity to other vertebrate TAP proteins was not detected in the N-terminal region. Segregation analysis of 34 individuals from two families showed exact restriction fragment length polymorphism matching between the MHC class Ia gene and the one TAP2 gene demonstrating linkage conservation since the mammalian/amphibian divergence ∼350 million years ago. In addition, one non-MHC-linked TAP2–hybridizing fragment was detected in approximately half of the individuals tested. Interestingly, TAP2 allelic lineages appear to match those of LMP7 and classical class I, which previously were categorized into two highly divergent groups that emerged at least 60 million years ago. Similar to LMP7 and class Ia,TAP2 is expressed ubiquitously with highest levels in intestine and spleen.
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    Organization of the genes encoding the human proteasome activators PA28α and β (1999)
    Springer
    Immunogenetics 49 (1999), S. 438-445 
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    ISSN: 1432-1211
    Keywords: Key words PA28 ; Proteasome ; Gene structure ; Evolution ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Two proteasome activators PA28α and β, which have been implicated in antigen processing for loading class I MHC molecules, are synthesized in response to Ifn-γ. The human genes encoding these activators (PSME1 and PSME2, respectively) were analyzed by sequencing. Each gene comprised 11 exons, consistent with gene duplication during vertebrate evolution. The intron/exon organization of both genes was highly conserved, the major difference being the absence of the exon encoding the lysine and glutamic acid-rich 'KEKE' motif in PA28β. Two other genes of relevance to the immune system were located close to those for PA28 at 14q11.2 including ISGF3G, a protein involved in transcription after IFNα signalling. These sequences were also characterized.
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    Variation in the number of expressed MHC genes in different cattle class I haplotypes (1999)
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    Immunogenetics 50 (1999), S. 319-328 
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    ISSN: 1432-1211
    Keywords: Key words Cattle ; MHC class I ; Haplotypes ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Analysis of cattle major histocompatibility complex (MHC) (BoLA) class I gene expression using serological and biochemical methods has demonstrated a high level of polymorphism. However, analysis of class I cDNA sequences has failed to produce conclusive evidence concerning the number and nature of expressed genes. Such information is essential for detailed studies of cattle immune responses, and to increase our understanding of the mechanisms of MHC evolution. In this study a selective breeding programme has been used to generate a number of MHC homozygous cattle expressing common serologically defined class I specificities. Detailed analysis of five class I haplotypes was carried out, with transcribed class I genes identified and characterized by cDNA cloning, sequence analysis, and transfection/expression studies. Surface expression of the gene products (on lymphocytes) was confirmed using monoclonal antibodies of defined BoLA specificity. Phylogenetic analysis of available transcribed cattle MHC class I sequences revealed complex evolutionary relationships including possible evidence for recombination. The study of individual haplotypes suggests that certain groupings of related sequences may correlate with loci, but overall it was not possible to define the origin of individual alleles using this approach. The most striking finding of this study is that none of the cattle class I genes is consistently expressed, and that in contrast to human, haplotypes differ from one another in both the number and composition of expressed classical class I genes.
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    A divergent non-classical class I gene conserved in salmonids (1999)
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    Immunogenetics 49 (1999), S. 479-490 
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    ISSN: 1432-1211
    Keywords: Key words Comparative immunology ; Evolution ; MHC class I ; Molecular biology ; Salmonids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Complementary DNA for two class I genes of the rainbow trout, Oncorhynchus mykiss, were characterized. MhcOnmy-UBA*01 is similar to Onmy-UA-C32 and the classical major histocompatibility complex class I genes of other fish species, whereas Onmy-UAA*01 is divergent from all class I genes so far characterized. Onmy-UAA*01 is expressed at lower levels than Onmy-UBA*01. Although Onmy-UAA*01 exhibits restriction fragment length polymorphism on Southern blotting, the encoded protein is highly conserved. Two allotypes, which differ only by substitution at amino acid position 223 of the α3 domain, have been defined. Onmy-UAA*01 has an exon-intron organization like other class I genes and contains a Tc1-like transposon element in intron III. Orthologues of Onmy-UAA*01 have been characterized in four other species of salmonid. Between four species of Oncorhynchus, UAA*01 proteins differ by only 2–6 amino acids, whereas comparison of Oncorhynchus with Salmo trutta (brown trout) reveals 14–16 amino acid differences. The Onmy-UAA*01 gene has properties indicative of a particularly divergent non-classical class I gene.
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    Evolution of the Mhc class I region: the framework hypothesis (1999)
    Springer
    Immunogenetics 49 (1999), S. 362-367 
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    ISSN: 1432-1211
    Keywords: Key words Major histocompatibility complex ; Class I region ; Evolution ; Orthology ; Olfactory receptor genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A comparison of the major histocompatibility complex (Mhc) region between human and mouse highlights both stability and differences. The class II and class III regions are orthologous; they probably existed in the ancestor in a similar organization and were not subjected to major rearrangement. The class I genes, by contrast, are definitely paralogous, having been reorganized several times. As long as only class I genes were identified, the class I regions of human and mouse were difficult to compare directly. The identification of non-class I genes has allowed a comparative map to be drawn, which shows that the class I region is orthologous between human and mouse as well. The lack of orthology specifically applies to the class I sequences. However, the comparative map shows that the non-orthologous class I sequences occupy homologous locations with regard to the conserved genes. I propose a model to explain this paradox. The conserved genes may represent samples of a dense "framework" of genes whose alterations are deleterious. The homologous positions occupied by class I genes would thus represent the few permissive places allowing major perturbations. The evolution of the class I sequences, by duplication and deletion, independently in the two species, has taken place within the scope defined by the framework: insertion at the permissive places, and expansion by creation of class I-related DNA by duplication, thus pushing back the boundaries of the framework.
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    Gene organization of the quail major histocompatibility complex (MhcCoja) class I gene region (1999)
    Springer
    Immunogenetics 49 (1999), S. 384-394 
    Details
    ISSN: 1432-1211
    Keywords: Key words Antigen processing ; Evolution ; Cell surface ; molecules ; Mhc ; Transporters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Class I genomic clones of the quail (Coturnix japonica) major histocompatibility complex (MhcCoja) were isolated and characterized. Two clusters spanning the 90.8 kilobase (kb) and 78.2 kb class I gene regions were defined by overlapping cosmid clones and found to contain at least twelve class I loci. However, unlike in the chicken Mhc, no evidence for the existence of any Coja class II gene was obtained in these two clusters. Based on comparative analysis of the genomic sequences with those of the cDNA clones, Coja-A, Coja-B, Coja-C, and Coja-D (Shiina et al. 1999), these twelve loci were assigned to represent one Coja-A gene, two Coja-B genes (Coja-B1 and -B2), four Coja-C genes (Coja-C1-C4), four Coja-D genes (Coja-D1-D4), and one new Coja-E gene. A class I gene-rich segment of 24.6 kb in which five of these genes (Coja-B1, -B2, -D1, -D2 and -E) are densely packed were sequenced by the shotgun strategy. All of these five class I genes are very compact in size [2089 base pairs (bp)–2732 bp] and contain no apparent genetic defect for functional expression. A transporter associated with the antigen processing (TAP) gene was identified in this class I gene-rich segment. These results suggest that the quail class I region is physically separated from the class II region and characterized by a large number of the expressible class I loci (at least seven) in contrast to the chicken Mhc, where the class I and class II regions are not clearly differentiated and only at most three expressed class I loci so far have been recognized.
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    MHC class I genes in a New World primate, the cotton-top tamarin (Saguinus oedipus), have evolved by an active process of loci turnover (1999)
    Springer
    Immunogenetics 49 (1999), S. 196-205 
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    ISSN: 1432-1211
    Keywords: Key words New world primates ; MHC ; Evolution ; Gene duplication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Lymphocytes of a New World primate, the cotton-top tamarin (Saguinus oedipus), express classical G–related major histocompatibility complex (MHC) class I molecules with unusually limited polymorphism and variability. Three G-related loci, an F locus, an E locus, and two pseudogenes (So-N1 and So-N3) have been identified by cDNA library screening and extensive PCR analysis of both cDNA and genomic DNA from the cotton-top tamarin. Furthermore, each genus of the subfamily Callitrichinae (tamarins and marmosets) appears to express its own unique set of MHC class I genes, likely due to a rapid turnover of loci. The rapid emergence of unique MHC class I genes in the Callitrichinae genera, resulting from an active process of duplication and inactivation of loci, may account for the limited diversity of the MHC class I genes in the cotton-top tamarin. To determine the nature of the entire complement of MHC class I genes in the cotton-top tamarin, we synthesized a genomic DNA library and screened it with MHC class I-specific probes. We isolated nine new MHC class I pseudogenes from this library. These newly isolated tamarin G–related MHC class I pseudogenes are not closely related to any of their functional counterparts in the tamarin, suggesting that they do not share a recent common ancestral gene with the tamarin's currently expressed MHC class I loci. In addition, these tamarin sequences display a high rate of nonsynonymous substitutions in their putative peptide binding region. This indicates that the genes from which they have derived were likely subject to positive selection and, therefore, were once functional. Our data support the notion that an extremely high rate of loci turnover is largely responsible for the limited diversity of the MHC class I genes in the cotton-top tamarin.
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    Evolution of a new nonclassical MHC class I locus in two Old World primate species (1999)
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    Immunogenetics 49 (1999), S. 86-98 
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    ISSN: 1432-1211
    Keywords: Key words MHC ; Primates ; Reproduction ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  HLA-G is a nonclassical major histocompatibility complex (MHC) class I molecule that is expressed only in the human placenta, suggesting that it plays an important role at the fetal-maternal interface. In rhesus monkeys, which have similar placentation to humans, the HLA-G orthologue is a pseudogene. However, rhesus monkeys express a novel placental MHC class I molecule, Mamu-AG, which has HLA-G-like characteristics. Phylogenetic analysis of AG alleles in two Old World primate species, the baboon and the rhesus macaque, revealed limited diversity characteristic of a nonclassical MHC class I locus. Gene trees constructed using classical and nonclassical primate MHC class I alleles demonstrated that the AG locus was most closely related to the classical A locus. Interestingly, gene tree analyses suggested that the AG alleles were most closely related to a subset of A alleles which are the products of an ancestral interlocus recombination event between the A and B loci. Calculation of the rates of synonymous and nonsynonymous substitution at the AG locus revealed that positive selection was not acting on the codons encoding the peptide binding region. In exon 4, however, the rate of nonsynonymous substitution was significantly lower than the rate of synonymous substitution, suggesting that negative selection was acting on these codons.
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    Opposite orientation of the α- and υ-chain constant region genes in the immunoglobulin heavy chain locus of the duck (1999)
    Springer
    Immunogenetics 49 (1999), S. 692-695 
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    ISSN: 1432-1211
    Keywords: Key words Duck ; Immunoglobulin genes ; IgH locus ; Class switching ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    Sequences and evolution of mammalian RH gene transcripts and proteins (1999)
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    Immunogenetics 49 (1999), S. 15-25 
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    ISSN: 1432-1211
    Keywords: Key words Rh blood group system ; Phylogenesis ; RH genes ; Evolution ; Nonhuman primates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The presence of Rh30-like polypeptides with an apparent relative molecular mass of 33 000 in the erythrocyte membranes from nonhuman primates and nonprimate mammals (mouse, rat, and dog) was demonstrated by immunoblotting. Nonhuman primates (orangutan, baboon, New World monkeys, lemur) and mouse Rh-like transcripts were amplified and sequenced. Analysis of the deduced amino acids sequences allowed us to determine the amino acid variability of Rh-like polypeptides which correlated with the hydrophylicity indexes. Hence, the putative transmembrane domains exhibited low indexes of variability, while the highest indexes were observed on extramembrane loops with a maximum on the sixth external loop. The cDNA sequences were compared with those previously reported in human, nonhuman primates, and cattle. The time of coalescence of mammalian Rh cDNA sequences was estimated by phylogenetic analysis to be 100 million years.
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    The catalytic group-I introns of the psbA gene of Chlamydomonas reinhardtii : core structures, ORFs and evolutionary implications (1999)
    Springer
    Current genetics 36 (1999), S. 69-78 
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    ISSN: 1432-0983
    Keywords: Key wordsChlamydomonas ; Chloroplast ; Evolution ; Group-I introns ; psbA gene ; Self-splicing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sequences and predicted secondary structures of the four catalytic group-I introns in the psbA gene of Chlamydomonas reinhardtii, Cr.psbA-1–Cr.psbA-4, have been determined. Cr.psbA-1 and Cr.psbA-4 are subgroup-IA1 introns and have similar secondary structures, except at the 3′ end where Cr.psbA-1 contains a large inverted-repeat domain. Cr.psbA-4 is closely related to intron 1 of the Chlamydomonas moewusii psbA gene, with which it shares the same location, high nucleotide identity in the core, and an identically placed ORF that shows 58% amino-acid identity. Cr.psbA-2 is a subgroup-IA3 intron, and shows similarities to the Chlamydomonas eugametos rRNA intron, Ce.LSU-1. Cr.psbA-3 is a subgroup-IA2 intron, and is remarkably similar to the T4 phage intron, sunY. Interestingly, a degenerate version of Cr.psbA-3 is located in the intergenic region between the chloroplast petA and petD genes. All four introns contain ORFs, which potentially code for basic proteins of 11–38 kDa. The ORFs in introns 2 and 3 contain variants of the GIY-YIG motif; however, the Cr.psbA-2 ORF is free-standing, whereas the Cr.psbA-3 ORF is contiguous and in-frame with the upstream exon. The Cr.psbA-4 ORF contains an H-N-H motif, and possibly a GIY-YIG motif. These data indicate that the C. reinhardtiipsbA introns have multiple origins, and illustrate some of the evolutionary DNA dynamics associated with group-I introns in Chlamydomonas.
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    Heterologous expression of soluble methane monooxygenase genes in methanotrophs containing only particulate methane monooxygenase (1999)
    Springer
    Archives of microbiology 171 (1999), S. 364-370 
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    ISSN: 1432-072X
    Keywords: Key words Heterologous expression ; Methane ; oxidation ; Methane monooxygenase ; Methanotroph ; Regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The methanotrophs Methylococcus capsulatus (Bath) and Methylosinus trichosporium OB3b contain particulate methane monooxygenase (pMMO) and soluble methane monooxygenase (sMMO) genes. Other methanotrophs such as Methylomicrobium album BG8 and Methylocystis parvus OBBP contain only pMMO genes. Although molecular genetic techniques are poorly developed in methanotrophs, sMMO genes were expressed in methanotrophs normally containing only pMMO genes. This was achieved by conjugation using broad-host-range plasmids containing the native promoter and sMMO genes from Mc. capsulatus (Bath) and Ms. trichosporium OB3b. sMMO genes derived from Ms. trichosporium OB3b were expressed in an active form in Mcy. parvus OBBP and in Mm. album BG8. Therefore, all of the genes required for active sMMO synthesis were contained on the broad-host-range plasmids and were expressed in the heterologous hosts. Constitutive synthesis of pMMO was observed in Mm. album BG8 when grown at high and low copper-to-biomass ratios, while transcription of the recombinant sMMO genes was only observed under growth conditions of low copper-to-biomass ratios. Therefore, the regulatory protein(s) for sMMO synthesis was also present on the plasmid used, or the heterologous host contained a regulatory system for sMMO. Expression of sMMO genes in methanotrophs containing only pMMO will assist further investigations on the expression and regulation of MMO genes in methanotrophs.
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    The [2Fe-2S] protein I (Shetna protein I) from Azotobacter vinelandii is homologous to the [2Fe-2S] ferredoxin from Clostridium pasteurianum (1999)
    Springer
    JBIC 4 (1999), S. 311-317 
    Details
    ISSN: 1432-1327
    Keywords: Key words Iron-sulfur ; Nitrogen fixation ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The [2Fe-2S] protein from Azotobacter vinelandii that was previously known as iron-sulfur protein I, or Shethna protein I, has been shown to be encoded by a gene belonging to the major nif gene cluster. Overexpression of this gene in Escherichia coli yielded a dimeric protein of which each subunit comprises 106 residues and contains one [2Fe-2S] cluster. The sequence of this protein is very similar to that of the [2Fe-2S] ferredoxin from Clostridium pasteurianum (2FeCpFd), and the four cysteine ligands of the [2Fe-2S] cluster occur in the same positions. The A. vinelandii protein differs from the C. pasteurianum one by the absence of the N-terminal methionine, the presence of a five-residue C-terminal extension, and a lesser number of acidic and polar residues. The UV-visible absorption and EPR spectra, as well as the redox potentials of the two proteins, are nearly identical. These data show that the A. vinelandii FeS protein I, which is therefore proposed to be designated 2FeAvFdI, is the counterpart of the [2Fe-2S] ferredoxin from C. pasteurianum. The occurrence of the 2FeAvFdI-encoding gene in the nif gene cluster, together with the previous demonstration of a specific interaction between the 2FeCpFd and the nitrogenase MoFe protein, suggest that both proteins might be involved in nitrogen fixation, with possibly similar roles.
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    URL: http://dx.doi.org/10.1007/s007750050317
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    Charge Transfer Between Oxygen and Zirconia (1999)
    Springer
    Journal of thermal analysis and calorimetry 57 (1999), S. 875-881 
    Details
    ISSN: 1572-8943
    Keywords: charge transfer ; Kelvin probe ; oxidation ; work function ; zirconia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The extent of the surface charge, that develops during oxidation of zirconia, is determined using work function measurements for both bulk specimen and thin films. The bulk specimen of yttria-doped zirconia (10 mol%) exhibits maxima of the surface electrical effect at 373 and 973 K (130 and 280 mV, respectively) that can be considered in terms of oxygen chemisorption and oxygen non-stoichiometry. Thin film of undoped zirconia exhibits a maximum at 473 K (260 eV). Addition of yttria (10 mol%) to the thin film results in a substantial reduction of the maximum, to about 140 eV, that is shifted up to 600 K.
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    URL: http://dx.doi.org/10.1023/A:1010119014821
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    Inhibited Oxidation of Cumene and Polymerization of Styrene Investigated by Solution Microcalorimetry (1999)
    Springer
    Journal of thermal analysis and calorimetry 57 (1999), S. 473-486 
    Details
    ISSN: 1572-8943
    Keywords: cumene ; oxidation ; polymerization ; quinone-amine inhibitors ; solution microcalorimetry ; styrene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The application of solution microcalorimetry was demonstrated on two model examples – inhibited oxidation of cumene and radical polymerization of styrene. From the experimental dependences of the rate of heat release on time, the rate constants k 7 of the interaction of an inhibitor with radicals of substrate (RO 2 . or R.) in oxidation or in polymerization were determined for the set of inhibitors of N-aryl N-(2-quinone) amine series. It was shown that these compounds are weak inhibitors of oxidation of cumene and rather efficient inhibitor of polymerization of styrene.
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    URL: http://dx.doi.org/10.1023/A:1010116024873
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    Oxidation of Styrene in a Silent Discharge Plasma (1999)
    Springer
    Plasma chemistry and plasma processing 19 (1999), S. 131-151 
    Details
    ISSN: 1572-8986
    Keywords: Styrene ; oxidation ; silent discharge ; plasma ; dielectric barrier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A silent discharge plasma reactor has been developed to study the oxidation of styrene vapor in argon/oxygen mixtures. A number of analytical techniques were employed to determine the destruction efficiency and to characterize the intermediate products. The destruction efficiency was measured as a function of initial styrene concentration, temperature, and energy density of the plasma. The formation of solid products was observed in most experiments. At low temperature (100°C), the solid deposit was polymeric in nature, while at high temperature (300°C) the solid appeared to be amorphous carbon. A combination of high temperature and high energy density resulted in high destruction efficiency and minimal production of solid films. The destruction efficiency vs. energy density is shown to be more complex than a simple model predicting exponential behavior. Several reasons for the discrepancy are suggested. The “e-folding” energy density for the destruction of styrene is compared to literature values for other organic compounds, measured using similar types of plasma reactors.
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    URL: http://dx.doi.org/10.1023/A:1021812201545
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    Oxidation of Dilute Benzene in an Alumina Hybrid Plasma Reactor at Atmospheric Pressure (1999)
    Springer
    Plasma chemistry and plasma processing 19 (1999), S. 383-394 
    Details
    ISSN: 1572-8986
    Keywords: Nonthermal plasma ; benzene ; Al2O3 ; BaTiO3 ; oxidation ; absorption ; atmospheric pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The combination of plasma discharge and adsorption was examined for oxidation of dilute benzene in air in a plasma reactor packed with a mixture of BaTiO 3 pellets and porous Al 2 O 3 pellets (i.e., an alumina hybrid reactor). The oxidative decomposition of benzene was enhanced by the benzene concentrating on the Al 2 O 3 pellets. Furthermore, there was a higher selectivity to CO 2 in the products from the hybrid than from a plasma reactor packed with BaTiO 3 pellets alone. The presence of the Al 2 O 3 pellets suppressed the formation of N 2 O.
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    URL: http://dx.doi.org/10.1023/A:1021820403362
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    Oxidation and Reduction Processes During NO x Removal with Corona-Induced Nonthermal Plasma (1999)
    Springer
    Plasma chemistry and plasma processing 19 (1999), S. 421-443 
    Details
    ISSN: 1572-8986
    Keywords: Streamer corona ; NO x removal ; nonthermal plasma ; oxidation ; reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract In this paper, the NO-to-NO 2 conversion in various gaseous mixtures is experimentally investigated. Streamer coronas are produced with a dc-superimposed high-frequency ac power supply (10–60 kHz). According to NO x removal experiments in N 2 +NO x and N 2 +O 2 +NO x gaseous mixtures, it is supposed that the reverse reaction NO 2 +O→NO+O 2 may not only limit NO 2 production in N 2 +NO x mixtures, but also increase the energy cost for NO removal. Oxygen could significantly suppress reduction reactions and enhance oxidation processes. The reduction reactions, such as N+NO→N 2 +O, induce negligible NO removal provided the O 2 concentration is larger than 3.6%. With adding H 2 O into the reactor, the produced NO 2 per unit removed NO can be significantly reduced due to NO 2 oxidation. NH 3 injection could also significantly decrease the produced NO 2 via NH and NH 2 - related reduction reactions. Almost 100% of NO 2 can be removed in gaseous mixtures of N 2 +O 2 +H 2 O+NO 2 with negligible NO production.
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    URL: http://dx.doi.org/10.1023/A:1021824504271
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    An in vitro study on the role of metal catalyzed oxidation in glyeation and crosslinking of collagen (1999)
    Springer
    Molecular and cellular biochemistry 194 (1999), S. 257-263 
    Details
    ISSN: 1573-4919
    Keywords: glycation ; oxidation ; collagen ; diabetes ; free radicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The present investigation was carried out to understand the effect of metal catalyzed oxidation on glycation and crosslinking of collagen. Tail tendons obtained from rats weighing 200-225 g were incubated with glucose (250 mM) and increasing concentrations of copper ions (5, 25, 50 and 100 μM) under physiological conditions of temperature and pH. Early glycation, crosslinking and late glycation (fluorescence) of collagen samples were analyzed periodically. Early glycation was estimated by phenol sulfuric acid method, and the crosslinking was assessed by pepsin and cyanogen bromide digestion. A concentrationdependent effect of metal ions on the rate of glycation and crosslinking of collagen was observed. Tendon collagen incubated with glucose and 100 μM copper ions showed 80% reduction in pepsin digestion within seven days, indicating extensive crosslinking, whereas collagen incubated with glucose alone for the same period showed only 7% reduction. The presence of metal ions in the incubation medium accelerated the development of Maillard reaction fluorescence on collagen, and the increase was dependent on the concentration of metal ions used. The metal chelator Diethylene triamine penta-acetate significantly prevented the increase in collagen crosslinking by glucose and copper ions. Free radical scavengers benzoate and mannitol effectively prevented the increased crosslinking and browning of collagen by glucose. The results indicate that the metal catalyzed oxidation reactions play a major role in the crosslinking of collagen by glucose. It is also suggested that the prevention of increased oxidative stress in diabetes may prevent the accelerated advanced glycation and crosslinking of collagen.
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    URL: http://dx.doi.org/10.1023/A:1006988719374
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    Attenuation of sugar cataract by ethyl pyruvate (1999)
    Springer
    Molecular and cellular biochemistry 200 (1999), S. 103-109 
    Details
    ISSN: 1573-4919
    Keywords: sugar cataract ; dulcitol ; glycation ; oxidation ; pyruvate ; ethyl pyruvate ; attenuation effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Studies describe an attenuation of sugar cataract formation by topical administration of ethyl pyruvate. Cataract formation was induced by feeding young rats a 30% galactose diet. Mature cataracts appeared in about thirty days. Instillation of the eye drops containing 5% ethyl pyruvate decelerated the process significantly. Biochemically, the effect was reflected by lowering in the contents of dulcitol and glycated proteins. The ATP levels were also higher in comparison to the placebo treated group. The effects are hence attributable to the effect of pyruvate in inhibiting dulcitol synthesis and protein glycation, in addition to its antioxidant properties and metabolic support. The use of esterified pyruvate instead of the unesterified pyruvate was preferred because of its greater penetration through the cornea and consequently a higher concentration attained in the aqueous humor.
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    URL: http://dx.doi.org/10.1023/A:1007055503748
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    Ellipsometric study of a palladium catalyst during the oxidation of carbon monoxide and methane (1999)
    Springer
    Topics in catalysis 8 (1999), S. 35-43 
    Details
    ISSN: 1572-9028
    Keywords: ellipsometry ; carbon monoxide ; methane ; palladium ; palladium oxide ; oxidation ; oscillations ; catalyst
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Spectroscopic ellipsometry is used to monitor the surface of a thick Pd‐film catalyst during the oxidation of either carbon monoxide or methane. Dense PdO layers form under sufficiently lean conditions (excess oxygen) for both reactions. A stable metal surface exists in the case of CO, but a very porous PdO layer develops in the case of methane, under rich conditions. There is a large hysteresis in the conditions for PdO formation in the case of CO oxidation. Spontaneous oscillations in catalytic activity and Pd‐surface composition occur for both reactions, the higher activities corresponding to O‐atom‐rich or PdO‐rich surfaces for CO or methane oxidation, respectively.
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    URL: http://dx.doi.org/10.1023/A:1019128203919
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    Laser Raman spectroscopy – a powerful tool for in situ studies of catalytic materials (1999)
    Springer
    Topics in catalysis 8 (1999), S. 45-55 
    Details
    ISSN: 1572-9028
    Keywords: Raman spectroscopy ; surface‐enhanced Raman spectroscopy ; oxidation ; synergy effects ; oxygen exchange ; oxidative coupling of methane ; nitric oxide decomposition ; methanol oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Advantages and limitations of laser Raman spectroscopy (LRS) as an in situ vibrational spectroscopy for the study of catalytic materials and surfaces under working conditions are discussed. Measurements can be carried out at temperatures as high as 1200 K in controlled atmospheres. Modern instrumentation permits time resolutions in the sub‐second regime for materials with high Raman cross sections. Transient studies are thus possible. Several examples are presented of in situ LRS studies including the phase analysis of bismuth molybdate and VPO oxidation catalysts, synergy effects and oxygen exchange in Sb2O3/MoO3 oxide mixtures, intermediates in oxidative coupling of methane, NO decomposition on Ba/MgO catalysts, and transient SERS studies of partial oxidation of methanol on Ag single crystal surfaces and of the reduction of oxide overlayers on electrodeposited Rh layers.
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    URL: http://dx.doi.org/10.1023/A:1019184321666
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    Tailoring Silicon Oxycarbide Glasses for Oxidative Stability (1999)
    Springer
    Journal of sol gel science and technology 14 (1999), S. 75-86 
    Details
    ISSN: 1573-4846
    Keywords: silicon oxycarbide ; BlackglasTM ; ceramic matrix composites ; 29Si NMR ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract BlackglasTM polysiloxane systems produce silicon oxycarbide glasses by pyrolysis in inert atmosphere. The silicon oxycarbides evidence oxidative degradation that limits their lifetime as composite matrices. The present study characterizes bonding rearrangements in the oxycarbide network accompanying increases in pyrolysis temperature. It also addresses the changes in susceptibility to oxidation due to variations in the distribution of Si bonded species obtained under different processing conditions. The study is carried out using 29Si nuclear magnetic resonance (NMR) spectroscopy and a design of experiments approach to model the oxidation behavior. The NMR results are compared with those obtained by thermogravimetric analysis (TGA). Samples pyrolyzed under inert conditions are compared to those pyrolyzed in reactive ammonia environments.
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    URL: http://dx.doi.org/10.1023/A:1008727914900
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    Insights into the Oxidation Chemistry of SiOC Ceramics Derived from Silsesquioxanes (1999)
    Springer
    Journal of sol gel science and technology 14 (1999), S. 49-68 
    Details
    ISSN: 1573-4846
    Keywords: silicon oxycarbide ; oxidation ; silsesquioxane ; preceramic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We have undertaken a systematic study of the oxidation chemistry for a range of SiOC ceramics derived from silsesquioxane polymeric precursors. This study examines the oxidation for 500 hours at 600, 800, 1000 and 1200°C for four SiOC powders. The material changes upon oxidation were characterized qualitatively by color change and optical microscopy and quantitatively by weight and composition change. In this study we employ a very easy method that uses the weight change upon oxidation and a carbon analysis after oxidation to arrive at the composition of the oxidized SiOC. Combined these qualitative and quantitative techniques have shown that on oxidation at 800 and 600°C the SiOC composition is more rapidly changed to that of silica than oxidation over the same time frame at 1000 or 1200°C. The data indicates that this difference is due to the relative rates of oxidation of the excess carbon versus the Si—C bonds in the SiOC. At lower temperatures initially the carbon oxidation predominates which leads to higher porosity throughout the material and an increase in the surface area with eventually ‘complete’ oxidation to silica. At higher temperatures the Si—C bond oxidation rate is comparable to the rate of oxidation of carbon. This allows a silica-like surface to build up on the SiOC, which slows all subsequent reactions due to the necessity to diffuse O2 in and COx out of the bulk. Under these oxidation conditions materials that originally contain high amounts of excess carbon are more quickly oxidized to silica than those that contain minimal amounts of excess carbon, as confirmed by elemental analysis and optical microscopy. Regardless of the time or temperature of the oxidation conditions no materials were found to be completely stable to oxidation. SiOC materials with low levels of excess carbon showed the best resistance to change upon oxidation.
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    URL: http://dx.doi.org/10.1023/A:1008723813991
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    Mössbauer effect study of anapaite, Ca2Fe2+(PO4)2 · 4H2O, and of its oxidation products (1999)
    Springer
    Physics and chemistry of minerals 26 (1999), S. 506-512 
    Details
    ISSN: 1432-2021
    Keywords: Key words Anapaite ; Mössbauer spectroscopy ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract Mössbauer spectra (MS) of anapaite (Ca2 Fe2+(PO4)2 · 4H2O) and of a sample after being immersed in a 4% H2O2 solution at room temperature (RT) over 12 days (hereafter an4ox) were collected at temperatures in the range 4.2 to 420 K and 11 to 300 K respectively. All MS consist of symmetrical doublets, hence magnetic ordering was not observed. The temperature dependencies of the Fe2+ centre shifts of anapaite and an4ox were analysed with the Debye model for the lattice vibrations. The characteristic Mössbauer temperatures were found as 370 K ± 25 K and 340 K ± 25 K, and the intrinsic isomer shifts as 1.427 ± 0.005 mm/s and 1.418 ± 0.005 mm/s respectively. From the external-field (60 kOe) MS recorded at 4.2 and 189 K for the non-treated sample, the principal component V zz of the electric field gradient (EFG) is determined to be positive and the asymmetry parameter η ≈ 0.2 and 0.4 respectively. The temperature variations of the quadrupole splittings, ΔE Q(T), cannot be interpreted on the basis of the thermal population of the 5 D electronic levels resulting from the tetragonal compression of the O6 co-ordination. The low-temperature linear behaviour of ΔE Q(T) is attributed to a strong orbit-lattice coupling. A field of 60 kOe applied to anapaite at 4.2 K produces magnetic hyperfine splitting with effective hyperfine fields of −136, −254 and −171 kOe along the principal axes Ox, Oy and Oz of the EFG tensor respectively. Additional oxidation treatments in solutions with various H2O2 concentrations up to 20% and subsequent Mössbauer experiments at room temperature, have revealed that the anapaite structure is not sensitive to oxidation since eventually only a small amount of Fe2+ (∼6.5%) is converted into Fe3+.
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    Detecting self-organisational change in economic processes exhibiting logistic growth (1999)
    Springer
    Journal of evolutionary economics 9 (1999), S. 109-133 
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    ISSN: 1432-1386
    Keywords: Key words: Discontinuity ; Evolution ; Logistic diffusion ; Non-linearity ; Non-stationarity ; Self-organisation ; Spectral methods ; JEL-classification: C4; C5; N1; N2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. This paper offers an econometric methodology for the detection of self-organisational change (defined in terms of the presence of time irreversibility, structural change and fundamental uncertainty) in economic processes that follow logistic diffusion growth paths in historical time. The approach we adopted is built upon recent developments in `moving window' spectral methods which are applied to the scaled residuals generated by estimated logistic diffusion models. We illustrate the use of such methods by examining the case of a financial instrument, namely, the Australian Building Society Deposit, which experienced logistic growth in its market share until bank deregulation was enacted in the 1980s. We show that there is clear evidence that self-organisational change is present over the historical period considered.
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    URL: http://dx.doi.org/10.1007/s001910050077
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    A note on evolutionary stability of Bertrand equilibrium (1999)
    Springer
    Journal of evolutionary economics 9 (1999), S. 367-371 
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    ISSN: 1432-1386
    Keywords: Key words: Bertrand ; Oligopoly ; Evolution ; Evolutionary stability ; JEL-classification: D43 ; L13 ; C72
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. It is shown that the equilibrium notion of an evolutionary stable strategy (ESS) does have predictive power for standard models of Bertrand competition. This is in contrast to a recent claim by Qin and Stuart (1997). The claim is based on the observation that the solution concept ESS behaves discontinuously when finite (discrete) action games approach an infinite (continuous) action game in the limit. Furthermore, it is argued that from a model-theoretic point of view evolutionary stability in prices (i.e. in the Bertrand model) is quite different from evolutionary stability in quantities (i.e. in the Cournot model).
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    Phylogenetic classification and molecular evolution of knotted1 homeobox genes (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 203-209 
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    ISSN: 1432-2242
    Keywords: Key words Homeobox gene ; KNOTTED1 ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Homeobox genes encode a family of DNA-binding regulatory proteins which are crucial for development. The first plant homeobox gene identified was knotted1 which plays a major role in leaf development. The knotted1 gene has a homeobox which encodes a homeodomain (HD) and HD proteins have been shown to function as transcription factors. A phylogenetic classification of the KNOTTED1 HD is presented. Here, we report six kn1 HDs from the cereals oat, barley, wheat, rye and rice. The KN1 class-I and -II genes can be divided into two distinct clades. Further, we hypothesize that KN1 and BELL1/MEIS HDs, (the closest non-KN1 class HDs) evolved from a common ancestor after divergence from the common precursor of all the homeobox genes. Our analysis clearly shows the presence of an ancestral KN1 HD from which all the known plant kn1 class of genes evolved.
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    Identification of genetic factors controlling domestication-related traits of rice using an F2 population of a cross between Oryza sativa and O. rufipogon (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 243-251 
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    ISSN: 1432-2242
    Keywords: Key words Common wild rice ; Cultivated rice ; Evolution ; Genetic analysis ; Molecular marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Domesticated rice differs from the wild progenitor in large arrays of morphological and physiological traits. The present study was conducted to identify the genetic factors controlling the differences between cultivated rice and its wild progenitor, with the intention to assess the genetic basis of the changes associated with the processes of rice domestication. A total of 19 traits, including seven qualitative and 12 quantitative traits, that are related to domestication were scored in an F2 population from a cross between a variety of the Asian cultivated rice (Oryza sativa) and an accession of the common wild rice (O. rufipogon). Loci controlling the inheritance of these traits were determined by making use of a molecular linkage map consisting of 348 molecular-marker loci (313 RFLPs, 12 SSRs and 23 AFLPs) based on this F2 population. All seven qualitative traits were each controlled by a single Mendelian locus. Analysis of the 12 quantitative traits resolved a total of 44 putative QTLs with an average of 3.7 QTLs per trait. The amount of variation explained by individual QTLs ranged from a low of 6.9% to a high of 59.8%, and many of the QTLs accounted for more than 20% of the variation. Thus, genes of both major and minor effect were involved in the differences between wild and cultivated rice. The results also showed that most of the genetic factors (qualitative or QTLs) controlling the domestication-related traits were concentrated in a few chromosomal blocks. Such a clustered distribution of the genes may provide explanations for the genetic basis of the “domestication syndrome” observed in evolutionary studies and also for the “linkage drag” that occurs in many breeding programs. The information on the genetic basis of some desirable traits possessed by the wild parent may also be useful for facilitating the utilization of these traits in rice-breeding programs.
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    Structural chromosome differentiation between Triticum timopheevii and T. turgidum and T. aestivum (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 744-750 
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    ISSN: 1432-2242
    Keywords: Key words Chromosome pairing ; Translocations ; T. timopheevii ; T. turgidum ; T. aestivum ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract.  Chromosome pairing at metaphase-I was analyzed in F1 hybrids among T. turgidum (AABB), T. aestivum (AABBDD), and T. timopheevii (AtAtGG) to study the chromosome structure of T. timopheevii relative to durum (T. turgidum) and bread (T. aestivum) wheats. Individual chromosomes and their arms were identified by means of C-banding. Homologous pairing between the A-genome chromosomes was similar in the three hybrid types AAtBG, AAtBGD, and AABBD. However, associations of B-G were less frequent than B-B. Homoeologous associations were also observed, especially in the AAtBGD hybrids. T. timopheevii chromosomes 1At, 2At, 5At, 7At, 2G, 3G, 5G, and 6G do not differ structurally from their counterpart in the A and B genomes. Thus, these three polyploid species inherited translocation 5AL/4AL from the diploid A-genome donor. Chromosome rearrangements that occurred at the tetraploid level were different in T. turgidum and T. timopheevii. Translocation 4AL/7BS and a pericentric inversion of chromosome 4A originated only in the T. turgidum lineage. The two lines of T. timophevii studied carry four different translocations, 6AtS/1GS, 1GS/4GS, 4GS/4AtL, and 4AtL/3AtL, which most likely arose in that sequence. These structural differences support a diphyletic origin of polyploid wheats.
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    URL: http://dx.doi.org/10.1007/s001220051130
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    p-SINE1-like intron of the CatA catalase homologs and phylogenetic relationships among AA-genome Oryza and related species (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 853-861 
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    ISSN: 1432-2242
    Keywords: Key words Catalase ; Oryza ; Rice ; Evolution ; p-SINE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Intron-2 of the Oryza sativa CatA catalase gene is similar in nucleotide sequence to p-SINE1, a retroposon, and seems to have been added to the ancestral genome of rice. To examine when the p-SINE1-like intron was inserted into CatA during the evolutionary divergence of Oryza species, and to elucidate the evolutionary relationships among Oryza species using the sequence of the intron as a marker, we performed polymerase chain reaction (PCR) analyses of 32 accessions of 17 Oryza species with various genome types. Agarose-gel electrophoresis of the PCR products revealed that all the Oryza species with an AA genome have the CatA homolog with the intron, whereas other Oryza species have the CatA homolog without the intron. These results indicate that intron-2 of CatA is a good marker for distinguishing species with an AA genome among Oryza species. Sequencing of the PCR products showed that all the introns are similar to p-SINE1, though with slight variations in length. We also performed PCR analyses using four accessions of three species in genera related to Oryza, and found that there is an intron in the CatA homolog of Leersia perrieri. On the other hand, the CatA homolog of Porteresia coarctata has no intron. Sequence data showed that the L. perrieri homolog has a p-SINE1-like intron similar to that in Oryza species with an AA genome. These results suggest that the p-SINE1-like intron was already present in the common ancestor of Oryza and L. perrieri and was then lost in the ancestors of P. coarctata and of the Oryza species other than those with an AA genome. The phylogenetic tree of Oryza species with an AA genome based on the nucleotide sequences of the introns leads us to propose that Oryza species with an AA genome evolved from an ancestor of Oryza longistaminata.
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    URL: http://dx.doi.org/10.1007/s001220051144
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    Uses and usefulness of endosperm balance number (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 478-484 
    Details
    ISSN: 1432-2242
    Keywords: Key words Endosperm development ; Evolution ; 2n gametes ; Breeding ; Potato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The Endosperm Balance Number (EBN) hypothesis was developed in the early ’80s to explain the basis for normal seed development after intra- and inter-specific crosses, first in the potato and then in several other crop species. According to this hypothesis, each species has a genome-specific effective ploidy, the EBN, which must be in a 2 : 1 maternal to paternal ratio in the hybrid endosperm for normal development of the endosperm itself. This paper reviews how the EBN may act as a powerful isolating mechanism in sexual reproduction, maintaining the genome integrity of the species and playing an important role in the speciation of polyploids from diploids. We also provide further evidence that EBN is more important than chromosome ploidy in determining the success or failure of interspecific crosses. In fact, results from inter-ploidy and inter-EBN crosses to infuse 1EBN Solanum commersonii into 4EBN S. tuberosum demonstrated that the knowledge and manipulation of EBN is a useful tool in designing breeding schemes and in predicting the offspring ploidy and EBN. In this paper we also discuss the exceptions to the 2 : 1 EBN ratio, and report the evidence for endomitosis in the polar nuclei to explain exceptions to the EBN model in the potato.
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    URL: http://dx.doi.org/10.1007/s001220051095
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    Evolution of extreme polyandry in the honeybee Apis mellifera L. (1999)
    Springer
    Behavioral ecology and sociobiology 45 (1999), S. 269-275 
    Details
    ISSN: 1432-0762
    Keywords: Key words Polyandry ; Evolution ; Social insects ; Apis mellifera ; Task allocation ; Division of labor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A number of hypotheses have been proposed to explain the evolution of multiple mating in the honeybee queen. In particular, the consequences of reduced intracolonial relatedness provide plausible explanations for multiple mating with up to ten drones, but fail to account for the much higher mating frequencies observed in nature. In this paper, we propose an alternative mechanism which builds on non-linear relationships between intracolonial frequencies in genotypic worker specialization and colony fitness. If genes for any worker specialization confer an advantage on colony fitness only when they are rare, this would require a stable mix of sperm from a few drones which contribute that trait, and many which do not. To ensure both specific, low within-colony proportions of “rare specialist” genes, and to reduce random variation of these proportions would require mating with high numbers of drones. The quantitative implementation shows that moderate to very high numbers of matings are required to exploit colony advantages from genotypic allocation of workers to rare tasks. Extreme polyandry thus could result from colony selection dependent on the intracolonial frequency of rare genetic specialists.
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    URL: http://dx.doi.org/10.1007/s002650050561
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    Hox genes in digit development and evolution (1999)
    Springer
    Cell & tissue research 296 (1999), S. 19-25 
    Details
    ISSN: 1432-0878
    Keywords: Key wordsHoxA ; HoxD ; Limb ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Homeobox genes located in the 5’ part of the HoxA and HoxD complexes are required for proliferation of skeletal progenitor cells of the vertebrate limb. Specific combinations of gene products determine the length of the upper arm (genes belonging to groups 9 and 10), the lower arm (groups 10, 11 and 12) and the digits (groups 11, 12 and 13). In these different domains, individual gene products quantitatively contribute to an overall protein dose, with predominant roles for groups 11 and 13. Quantitative reduction in the gene dose in each set results in truncations of the corresponding anatomical regions. The physical order of the genes in the HoxA and HoxD complexes, as well as a unidirectional sequence in gene activation, allow for completion of the process in a precise order, which in turn makes possible the sequential outgrowth of the respective primordia. While the skeletal patterns of upper and lower limb are relatively stable throughout the tetrapods, more variation is seen in the digits. Molecular analysis of the underlying regulatory processes promises further exciting insights into the genetic control of development, pathology and the course of evolution.
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    URL: http://dx.doi.org/10.1007/s004410051262
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    Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium (1999)
    Springer
    Cell & tissue research 296 (1999), S. 395-404 
    Details
    ISSN: 1432-0878
    Keywords: Key words Metabotropic glutamate/GABA-like receptor ; Evolution ; Geodia cydonium (Porifera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium[Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-α-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mGluR-like protein. A cDNA encoding rat mGluR subtype 1 has been used to identify the complete nucleotide sequence of G. cydonium cDNA coding for a 528-amino-acid-long protein (59 kDa) that displays marked overall similarity to mGluRs and to γ-amino-butyric acid B receptors. The deduced sponge polypeptide, termed putative mGlu/GABA-like receptor, displays the highest similarity to the two families of metabotropic receptors within the transmembrane segment. The N-terminal part of the sponge sequence shows similarity to mGluR4 and mGluR5. These findings suggest that the earliest evolutionary metazoan phylum, the Porifera, possesses a sophisticated intercellular communication and signaling system, as seen in the neuronal network of higher Metazoa.
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    URL: http://dx.doi.org/10.1007/s004410051299
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    Isolation and functional characterisation of a novel type of carotenoid biosynthetic gene from Xanthophyllomyces dendrorhous (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 453-461 
    Details
    ISSN: 1617-4623
    Keywords: Key words Phytoene synthase ; Lycopene cyclase ; Complementation ; Astaxanthin ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The red heterobasidiomycetous yeast Xanthophyllomyces dendrorhous (perfect state of Phaffia rhodozyma) contains a novel type of carotenoid biosynthetic enzyme. Its structural gene, designated crtYB, was isolated by functional complementation in a genetically modified, carotenogenic Escherichia coli strain. Expression studies in different carotenogenic E. coli strains demonstrated that the crtYB gene encodes a bifunctional protein involved both in synthesis of phytoene from geranylgeranyl diphosphate and in cyclisation of lycopene to β-carotene. By sequence comparison with other phytoene synthases and complementation studies in E. coli with various deletion derivatives of the crtYB gene, the regions responsible for phytoene synthesis and lycopene cyclisation were localised within the protein.
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    URL: http://dx.doi.org/10.1007/s004380051105
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    The cost of selfing inEncyclia cochleata (Orchidaceae) (1999)
    Springer
    Plant systematics and evolution 219 (1999), S. 55-64 
    Details
    ISSN: 1615-6110
    Keywords: Evolution ; Encyclia cochleata ; inbreeding depression ; isozymes ; Orchidaceae ; outcrossing ; phenotype ; population genetics ; selfing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To determine whether inbreeding depression accounts for the maintenance of outcrossing in populations of the self-compatible orchidEncyclia cochleata, the estimated selective advantage of selfing was compared to a measure of inbreeding depression. Individuals from three populations ofE. cochleata and some of their progeny were phenotyped using isozyme analysis. The electrophoretic data were used to estimate the outcrossing rate and the theoretical cost of outcrossing. Inbreeding depression was estimated by comparing the fitness of the progeny resulting from both types of pollinations. The seeds from outcrossed and selfed hand-pollinations and naturally pollinated seeds from a population of the triandrous form ofE. cochleata were grown aseptically on culture media, and their development over the next three years recorded. Inbreeding was common, particularly in one population (outcrossing rate 40%). However, the level of inbreeding depression was only 1–2%, considerably less inbreeding depression than expected.
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    URL: http://dx.doi.org/10.1007/BF01090299
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    The species fitness method for the evolution of cooperative behavior in a group task (1999)
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    Artificial life and robotics 3 (1999), S. 127-132 
    Details
    ISSN: 1614-7456
    Keywords: Evolution ; Cooperative behavior ; Communication ; Species fitness ; Reciprocative
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper considers the evolution of cooperative behaviors as the interaction among agents using a genetic algorithm to improve the performance of the task in a group (group performance). Previous research often usedthe group fitness method, which evaluates group performance for the evolution of multiple groups in parallel. However, this entails large simulation costs and the evolution speed is slow.The individual fitness method that evaluates theindividual performance of the task entails a smaller simulation cost. However, it can not improve the group performance since each agent behaves selfishly. To optimize the group performance, it is important to include bothcompetition andsharing. Therefore, this paper presentsthe species fitness method, which shares the individual performances of agents belonging to the same species in a group that all have the same chromosomes. We show comparative experiments on these three methods on the evolutionary simulation of a foraging task in a group. To test the interaction among the agents, four kinds of species are evolved which show their communication ability by demonstrating whether the agent can send or receive the signal for food. Experimental results show that evaluating the species variance fitness leads the agents into reciprocative actions.
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    URL: http://dx.doi.org/10.1007/BF02481127
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    Computational evolution of human bipedal walking by a neuro-musculo-skeletal model (1999)
    Springer
    Artificial life and robotics 3 (1999), S. 133-138 
    Details
    ISSN: 1614-7456
    Keywords: Bipedal walking ; Evolution ; Neuro-musculoskeletal model ; Genetic algorithms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The acquisition process of bipedal walking in humans was simulated using a neuro-musculo-skeletal model and genetic algorithms, based on the assumption that the shape of the body has been adapted for locomotion. The model was constructed as 10 two-dimensional rigid links with 26 muscles and 18 neural oscillators. Bipedal walking was generated as a mutual entrainment between neural oscillations and the pendulous movement of body dynamics. Evolutionary strategies incorporated, for example, as fitness in the genetic algorithms were assumed to decrease energy consumption, muscular fatigue, and load on the skeletal system. An initial population of 50 individuals was created, and an evolutionary simulation of 5000 steps was conducted. As a result, the shape of the body changed from that of a chimpanzee to that of a modern human, and the body size nearly reached the size of a modern human. These simulation results show that improving locomotive efficiency and reducing the load on the musculo-skeletal system are important factors affecting the evolution of the human body shape and bipedal walking. Such computer simulations help us to understand the process of evolution and adaptation for locomotion in humans.
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    Universal Correlation of Nitrogen 1s and Oxygen 1s Photoelectron Binding Energies with Chemical Composition in Nitrogen-Containing Plasma Polymers (1999)
    Springer
    Plasmas and polymers 4 (1999), S. 283-307 
    Details
    ISSN: 1572-8978
    Keywords: Plasma polymers ; oxidation ; XPS ; photoelectron binding energy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The incorporation of oxygen into nitrogen-containing plasma deposited polymers was studied by X-ray Photoelectron Spectroscopy (XPS). As the oxygen content of the plasma polymer increased, the binding energy of the N 1s photoelectrons increased. Conversely, the binding energy of the O 1s photoelectrons was inversely proportional to the nitrogen content of the plasma polymer. The data from a large number of samples all obeyed the same “universal” correlations of photoelectron binding energy versus chemical composition. The data were described by the same curve regardless of whether the oxygen was incorporated rapidly into the thin film during plasma deposition or whether the oxygen was added slowly during spontaneous oxidation of the film in air. This implies that the same thermodynamic principles of radical reactions governed the addition of oxygen to the plasma polymer. The shift in the O 1s and N 1s photoelectron binding energies as a function of chemical composition was used to monitor the proximity of nitrogen and oxygen. By contrasting the experimental data with a simple binomial model which described the random addition of oxygen to a lattice containing carbon and nitrogen, we were able to show that oxygen was preferentially added near nitrogen-containing groups in plasma polymers.
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    URL: http://dx.doi.org/10.1023/A:1021831527895
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    A Tourist element in the 5′-flanking region of the catalase gene CatA reveals evolutionary relationships among Oryza species with various genome types (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 493-500 
    Details
    ISSN: 1617-4623
    Keywords: Key words Catalase ; Oryza ; Rice ; Evolution ; Tourist
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tourist-OsaCatA, a transposable element, was found in the 5′-flanking region of the rice gene CatA. The characteristics of this element are similar to those of the other Tourist elements so far found in Oryza sativa. PCR and sequence analyses of 37 accessions of 18 species revealed that all the Oryza species examined, except for one accession, have either a full-length or a partial Tourist element at this locus. Unlike the Tourist elements previously reported, this Tourist element is found in all four Oryza species complexes in the Oryzeae tribe. All AA genome Oryza species, except O. longistaminata, contain the full-length Tourist element. O. longistaminata and the species of the O. officinalis, O. meyeriana and O. ridleyi complexes contain the partial element. A phylogenetic tree of Oryza species based on the nucleotide sequences of these Tourist elements was constructed. The O. longistaminata accessions were placed near the neighboring cluster of the officinalis complex. We propose that the ancestor of O. longistaminata and that of other species with the AA genome diverged, and the ancestor(s) of the O. officinalis, O. ridleyi and O. meyeriana complexes then diverged from the ancestor of O. longistaminata in the course of the evolution of the Oryza species. The Tourist elements associated with CatA and its orthologs thus provide useful tools for examining evolutionary relationships among Oryza species.
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    URL: http://dx.doi.org/10.1007/s004380051110
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    Representational difference analysis identifies a strain-specific LPS biosynthesis locus in Bordetella spp. (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 189-198 
    Details
    ISSN: 1617-4623
    Keywords: Key wordsBordetella spp. ; Evolution ; Lipopolysaccharide biosynthesis ; Pulsed-field gel electrophoresis ; Representational difference analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bordetella pertussis and B. bronchiseptica are genetically very closely related but differ significantly in their virulence properties. Using Representational Difference Analysis (RDA), 11 DNA fragments specific for B. pertussis Tohama I or B. bronchiseptica BB7865 were identified. All B. bronchiseptica BB7865-derived fragments also hybridized with chromosomal DNA from B. parapertussis but not from the B. pertussis strains Tohama I and W28, underlining the close phylogenetic relationship between B. bronchiseptica and B. parapertussis. The B. pertussis type strain BP18323 is a special case, as it contains DNA sequences characteristic for both B. pertussis and B. bronchiseptica. As demonstrated by pulsed-field gel electrophoresis, several of the BB7865-derived fragments are present on a single 30-kb XbaI fragment. Based on the sequences of putative coding regions, four of these fragments may code for proteins involved in carbohydrate metabolism or transport. In agreement with this notion, a mutant for one of these loci synthesizes a significantly altered lipopolysaccharide that lacks the O-specific side chains. The analysis of the corresponding genomic region in various Bordetella species showed that this locus is present in B. bronchiseptica and B. parapertussis but not in B. pertussis. This confirms that the RDA approach has identified a novel strain-specific LPS biosynthesis locus which accounts for the differences between the LPS structures elaborated by different Bordetella species.
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    URL: http://dx.doi.org/10.1007/s004380051074
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    The Fate and Effects of Ingested Hydrolyzable Tannins in Porcellio scaber (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 611-628 
    Details
    ISSN: 1573-1561
    Keywords: Terrestrial isopods ; Oniscidea ; Porcellio scaber ; phenolics ; hydrolysis ; oxidation ; detoxification ; hindgut cuticle ; gut microbiota ; hepatopancreatic bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract When adults of Porcellio scaber fed on litter prior to an artificial diet containing 5% of commercially available tannic acid, 55% of the ingested galloylglucose esters was excreted unchanged, about 25% was hydrolyzed, and 20% was oxidized during the gut passage. After reducing the counts of microorganisms in the gut of P. scaber, the data obtained indicated an important role of ingested platable microorganisms in hydrolyzing gallotannins. Oxidation of phenolics appeared to be mainly due to the endosymbiotic bacteria of the hepatopancreas. Microbial counts in the hindgut were strongly reduced by ingested galloylglucose esters, while gallic acid in the diet (2%) reduced the number of palatable fungi and bacteria less strikingly, and increased the total number of the gut microbiota. Hepatopancreatic bacteria were only slightly affected by ingested tannic acid, since the hepatopancreas contained only few galloylglucose esters. This may be due to the permeability of the hindgut cuticle: the cuticle of the anterior hindgut was freely permeable to gallic acid, while it was nearly impermeable to larger polyphenols. The cuticle of the posterior hindgut was permeable to only about 4% of the gallic acid present in the hindgut lumen. The results are discussed with respect to potentially harmful effects of ingested hydrolyzable tannins and their digestion in Porcellio scaber.
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    URL: http://dx.doi.org/10.1023/A:1020962105931
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    Temperature effects on soil organic sulphur mineralization and elemental sulphur oxidation in subtropical soils of varying pH (1999)
    Springer
    Nutrient cycling in agroecosystems 54 (1999), S. 175-182 
    Details
    ISSN: 1573-0867
    Keywords: elemental sulphur ; oxidation ; organic S ; mineralization ; immobilization ; S fertilizers ; semiarid soils ; subtropical region
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The increasing sulphur (S) deficiency in soils of several parts of world has led to the use of fertilizer S, an important factor in enhancing the production and quality of crops. Very limited information is available on the use of elemental sulphur (S0) as a fertilizer, its oxidation into SO42- and transformation into organic S in semiarid subtropical soils. We studied the impact of three temperature regimes on the mineralization of soil organic S, and the oxidation and immobilization of S0 in acidic (pH 4.9), neutral (pH 7.1) and alkaline (pH 10.2) subtropical soils of north-western India. Repacked soil cores were incubated under aerobic conditions (60% water-filled pore space) for 0, 14, 28 and 42 d with and without incorporated S0 (500 μg g-1 soil). Temperature had profound effects on all three soils processes, the rates of mineralization of native soil organic S, oxidation of applied S0 and transformation of S0 into soil organic S being greatest at 36 °C, irrespective of soil pH. Mineralization of native soil organic S (without added S0) resulted in the accumulation of 39, 66 and 47 μg SO42-–S g-1 soil in acidic, neutral and alkaline soil in 42 d period at 36 °C. Of the total mineralization, the majority (62 – 74%) occurred during the first 14 d period. Oxidation rate of added S0 during initial 14 d period at 36 °C was highest in alkaline soil (292 μg S cm-2 d-1), followed by neutral soil ((180 μg S cm-2 d-1) and lowest in acidic soil (125 μg S cm-2 d-1). Of the applied 500 μg S0 g-1 soil, 3.2 – 10.0%, 6.8 – 15.4% and 10.0 – 23.0% oxidized to SO42-, and 13.4 – 28.6%, 16.0 – 29.0% and 14.6 – 29.0% were transformed into organic S in 42 d period in acidic, neutral and alkaline soil, respectively. The results of our study suggest that in order to synchronize the availability of S with plant need, elemental S may be applied well before the seeding of crops, especially in acidic soil and in regions where temperature remains low. Substantial mineralization of native soil organic S in the absence of applied S0 and immobilization of applied S0 into organic S suggest that the role of soil biomass as source and sink could be exploited in long term S management.
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    Transformation of diphenyl ethers by Trametes versicolor and characterization of ring cleavage products (1999)
    Springer
    Biodegradation 10 (1999), S. 279-286 
    Details
    ISSN: 1572-9729
    Keywords: Diphenyl ether ; ligninolytic enzymes ; metabolites ; oxidation ; Trametes versicolor ; white-rot fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The white-rot fungi Trametes versicolor SBUG 1050, DSM 11269 and DSM 11309 are able to oxidize diphenyl ether and its halogenated derivatives 4-bromo- and 4-chlorodiphenyl ether. The products formed from diphenyl ether were 2- and 4-hydroxydiphenyl ether. Both 4-bromo- and 4-chlorodiphenyl ether were transformed to the corresponding products hydroxylated at the non-halogenated ring. Additionally, ring-cleavage products were detected by high perfomance liquid chromatography and characterized by gas chromatography/mass spectrometry and proton nuclear magnetic resonance spectroscopy. Unhalogenated diphenyl ether was degraded to 2-hydroxy-4-phenoxymuconic acid and 6-carboxy-4-phenoxy-2-pyrone. Brominated derivatives of both these compounds were formed from 4-bromodiphenyl ether, and 4-chlorodiphenyl ether was transformed in the same way to the analogous chlorinated ring cleavage products. Additionally, 4-bromo- and 4-chlorophenol were detected as intermediates from 4-bromo- and 4-chlorodiphenyl ether, respectively. In the presence of the cytochrome-P450 inhibitor 1-aminobenzotriazole, no metabolites were formed by cells of Trametes versicolor from the diphenyl ethers investigated. Cell-free supernatants of whole cultures with high laccase and manganese peroxidase activities were not able to transform the unhydroxylated diphenyl ethers used.
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    TG Measurements of the Oxidation Kinetics of Fe-Cr Alloy with Regard to its Application as a Separator in SOFC (1999)
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 681-690 
    Details
    ISSN: 1572-8943
    Keywords: chromia ; Fe-Cr alloy ; gas-solid reaction kinetics ; H2/H2O gas mixtures ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The high-temperature oxidation behavior of a ferritic alloy (SUS 430) in a SOFC environment, corresponding to the anode (H2/H2O gas mixture) and cathode (air) operating conditions, was determined with regard to application of the alloy as a metallic separator material in SOFC. The oxidation kinetics of Fe-16Cr alloy (SUS 430), was studied by thermogravimetry in H2/H2O gas mixtures with pH/pHO=94/6 and 97/3 and in air, in the temperature range 1023-1223 K, for 3.6 up to 1080 ks. It was found that the protective oxide scale, composed mainly of Cr2O3 with uniform thickness and excellent adhesion to the metal substrate, grows in accordance with the parabolic rate law. The dependence of the parabolic rate constant, kp, of the scale on temperature obeys the Arrhenius equation: kp=6.8×10-4 exp (-202.3 kJ mol-1R-1T-1) for H2/H2O gas mixtures with pH/pHO=94/6. The determined kp was independent of the oxygen partial pressure in the range from 5.2×10-22 to 0.21 atm at 1073 K, which means that the rates of growth of the scale on Fe-16Cr alloy in the above-mentioned atmospheres are comparable. The oxidation test results on Fe-16Cr alloy in H2/H2O gas mixtures and air demonstrate the applicability of SUS 430 alloys as a separator for SOFC.
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    The Detailed Mechanism of Oxidation of Ni-P Alloys (1999)
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 981-987 
    Details
    ISSN: 1572-8943
    Keywords: nickel phosphates ; nickel phosphides ; Ni-P alloys ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract DTA in conjuction with X-ray diffraction analysis with a high-temperature camera and infrared spectroscopy was employed to determine the mechanism of oxidation of Ni-P alloys. Amorphous Ni-P powders were obtained from a nickel(II) sulphate bath as a nickel source and sodium dihydrophosphate(I) as a reducing agent. The crystallization product is composed of two phases: (f.c.c.) Ni and (b.c.t.) Ni3P. The amorphous to crystalline transformation takes place in the temperature range 280–330°C. Ni3P samples were heated from room temperature to 1050°C in air atmosphere at 5°C min−1. It was found that the first stage of oxidation of Ni3P goes through the intermediate phase of Ni12P5 formation to Ni2P. Some exothermic reactions were observed. Heating runs were interrupted after each reaction for crystal structure determination by IR spectrometry. Infrared spectra are reported and it is shown that the structure units present in the amorphous products at about 700°C were the oxoanions PO3 − and P2O7 −. The final products of the oxidation process are NiO and Ni3(PO4)2.
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    URL: http://dx.doi.org/10.1023/A:1010106506249
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    A Database of Normal Spectral Emissivities of Metals at High Temperatures (1999)
    Springer
    International journal of thermophysics 20 (1999), S. 299-308 
    Details
    ISSN: 1572-9567
    Keywords: high temperature ; metal ; spectral emissivity ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The normal spectral emissivity and its time variation were measured systematically for a total of thirty kinds of pure metals and alloys at temperatures between 780 and 1200°C. The spectral data were obtained at about 100 wavelengths from 0.55 to 5.3 μm under different environmental conditions including oxidation. The spectral data were stored in a database with supplementary information on the specimens. Clear oscillations of the spectral emissivity with time and wavelength were observed for nickel, Inconel, and SUS444 as surface oxidation progressed, while emissivity variations were rather monotonic for other metals such as titanium, cold-rolled steel, and SUS310S. The surface roughness was measured for all specimens by a contact-type instrument before the measurements, and recorded as supplementary information in the database. The database was built on a personal computer operating system (Windows95) to facilitate the dissemination to researchers and engineers interested in the emissivity of metals. Indexes to the emissivity data are metal name, wavelength, temperature, time, and degree of oxidation represented by an effective thickness of oxide film on the specimen surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021467322442
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    System for Measuring the Spectral Distribution of Normal Emissivity of Metals with Direct Current Heating (1999)
    Springer
    International journal of thermophysics 20 (1999), S. 289-298 
    Details
    ISSN: 1572-9567
    Keywords: high temperature ; metal ; spectral emissivity ; oxidation ; radiation thermometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A system for measuring time variations of the normal spectral emissivity at wavelengths ranging from 0.55 to 5.3 μm was developed and applied to metal specimens in vacuum and oxidizing environments in the temperature range from 780 to 1200° C. The specimen was heated to high temperatures by passing a direct current in a vacuum chamber, and the surface oxidation was controlled by a low-pressure oxidizing gas. The specimen temperature was measured by a single-band (0.9-μm) radiation thermometer viewing at a cavity formed in the specimen from the rear side. The front surface of the specimen was observed by a multiband (112-wavelength) radiation thermometer to measure the normal spectral emissivity. The effective normal spectral emissivity of the specimen cavity was evaluated to be 0.94±0.05 at a wavelength of 0.9 μm in comparison with a metal tube having a small blackbody hole on the rear. The measurement uncertainty of the normal spectral emissivitiy by the system was estimated to be 5 to 10% of the emissivity value in most of the interesting ranges of emissivities, temperatures, and wavelengths.
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    URL: http://dx.doi.org/10.1023/A:1021415305603
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    Metabolism of Anxiolytics and Hypnotics: Benzodiazepines, Buspirone, Zoplicone, and Zolpidem (1999)
    Springer
    Cellular and molecular neurobiology 19 (1999), S. 533-552 
    Details
    ISSN: 1573-6830
    Keywords: benzodiazepines ; cytochromes P450 ; oxidation ; reduction ; conjugation ; drug interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. The benzodiazepines are among the most frequently prescribed of all drugs and have been used for their anxiolytic, anticonvulsant, and sedative/hypnotic properties. Since absorption rates, volumes of distribution, and elimination rates differ greatly among the benzodiazepine derivatives, each benzodiazepine has a unique plasma concentration curve. Although the time to peak plasma levels provides a rough guide, it is not equivalent to the time to clinical onset of effect. The importance of α and β half-lives in the actions of benzodiazepines is discussed. 2. The role of cytochrome P450 isozymes in the metabolism of benzodiazepines and in potential pharmacokinetic interactions between the benzodiazepines and other coadministered drugs is discussed. 3. Buspirone, an anxiolytic with minimal sedative effects, undergoes extensive metabolism, with hydroxylation and dealkylation being the major pathways. Pharmacokinetic interactions of buspirone with other coadministered drugs seem to be minimal. 4. Zopiclone and zolpidem are used primarily as hypnotics. Both are extensively metabolized; N-demethylation, N-oxidation, and decarboxylation of zopiclone occur, and zolpidem undergoes oxidation of methyl groups and hydroxylation of a position on the imidazolepyridine ring system. Zopiclone has a chiral centre, and demonstrates stereoselective pharmacokinetics. Metabolic drug–drug interactions have been reported with zopiclone and erythromycin, trimipramine, and carbamazepine. Reports to date indicate minimal interactions of zolpidem with coadministered drugs; however, it has been reported to affect the C max and clearance of chlorpromazepine and to decrease metabolism of the antiviral agent ritonavin. Since CYP3A4 has been reported to play an important role in metabolism of zolpidem, possible interactions with drugs which are substrates and/or inhibitors of that CYP isozyme should be considered.
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    URL: http://dx.doi.org/10.1023/A:1006943009192
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    Oxidative Resistance of Na/K-ATPase (1999)
    Springer
    Cellular and molecular neurobiology 19 (1999), S. 133-140 
    Details
    ISSN: 1573-6830
    Keywords: Na/K-ATPase ; SH groups ; oxidation ; hydrogen peroxide ; hypochlorite ; antioxidants ; carnosine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Oxidative modification of Na/K-ATPase from brain and kidney has been studied. Brain enzyme has been found to be more sensitive than kidney enzyme to inhibition by both H2O2 and NaOCl. 2. The inhibition of Na/K-ATPase correlates well with the decrease in a number of SH groups, suggesting that the latter belong mainly to ATPase protein and are essential for the enzyme activity. We suggest that the differences in the number, location, and accessibility of SH groups in Na/K-ATPase isozymes predict their oxidative stability. 3. The hydrophilic natural antioxidant carnosine, the hydrophobic natural antioxidant α-tocopherol, and the synthetic antioxidant ionol as well as the ferrous ion chelating agent deferoxamine were found to protect Na/K-ATPase from oxidation by different concentrations of H2O2. The data suggest that these antioxidants are effective due to their ability to neutralize or to prevent formation of hydroxyl radicals.
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    URL: http://dx.doi.org/10.1023/A:1006976810642
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    Soil Covers for Controlling Acid Generation in Mine Tailings: a Laboratory Evaluation of the Physics and Geochemistry (1999)
    Springer
    Water, air & soil pollution 114 (1999), S. 347-375 
    Details
    ISSN: 1573-2932
    Keywords: diffusion coefficient ; gaseous oxygen ; mine tailings ; oxidation ; water content
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract To evaluate the effectiveness of soil covers, column experiments were conducted on tailings protected by a three-layer soil cover and tailings directly exposed in the open laboratory for a period of 760 days. Periodic rain application was performed to simulate field conditions, and at four times during the experiments the pore water was completely flushed out of each column for analysis. Profiles of oxygen, temperature, and volumetric water content were measured throughout the experiment, and the post-testing pore water quality was also characterized. A one-dimensional semi-analytic diffusion model was used to simulate oxygen profiles in the uncovered tailings. Modelling performed using the geochemical code MINTEQ showed that in the laboratory, aluminium concentrations in the tailings pore water were controlled by Al(OH)SO4, sulphate by gypsum and Al(OH)SO4and iron by lepidocrocite in the upper half and by ferrihydrite in the lower half. In the field, however, the iron oxyhydroxide minerals formed in the oxidized zone appear to be dissolving. It was found that the cover was effective in preventing significant desaturation of the clay, even over a 150-day drying period. The covered tailings did not oxidize much during the experiments. In the uncovered tailings, oxygen modelling and examination of the geochemistry show that the rate of gross oxidation and the advancement of the oxidation front decreases with time. However, pore water quality is controlled by geochemical processes other than oxidation, as reported in the field.
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    URL: http://dx.doi.org/10.1023/A:1005187613503
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    Study of the selectivity of a V2O5−ZrO2 catalyst for partial oxidation ofo-xylene at high temperatures (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 237-243 
    Details
    ISSN: 1588-2837
    Keywords: V2O5−ZrO2 catalyst ; oxidation ; o-xylene ; temperature stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It has been established that at high temperatures (above 450°C) the V2O5−ZrO2 catalyst exhibits a higher selectivity in the oxidation ofo-xylene to phthalic anhydride than does the conventional V2O5−TiO2(a) catalyst. The catalyst selectivity is found to increase with respect to partial oxidation ofo-xylene, the valuable by-product maleic anhydride being obtained. Studies by different physicochemical methods have shown that V2O5−ZrO2 undergoes no significant phase and structural changes under high-temperature conditions.
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    Temperature hysteresis in CO oxidation on catalysts of various nature (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 97-104 
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    ISSN: 1588-2837
    Keywords: Heterogeneous catalysis ; oxidation ; temperature hysteresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The temperature hysteresis observed in the oxidation of CO on both supported and unsupported catalysts can be explained by the local overheating of active centers rather than by transitions from one steady state to another.
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    URL: http://dx.doi.org/10.1007/BF02475747
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    Influence of Nox on soot combustion with supported molten salt catalysts (1999)
    Springer
    Reaction kinetics and catalysis letters 67 (1999), S. 3-7 
    Details
    ISSN: 1588-2837
    Keywords: Catalyst ; ceramic foam ; molten salt ; Nox ; oxidation ; soot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Diesel soot is combusted simultaneously by two reactions: combustion with NO2 and combustion with O2 with the aid of a molten salt catalyst. Both reaction pathways should always be considered to avoid misinterpretation of experimental data.
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    URL: http://dx.doi.org/10.1007/BF02475819
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    Enthalpies of elementary chain propagation steps in the oxidation of organic compounds (1999)
    Springer
    Reaction kinetics and catalysis letters 68 (1999), S. 285-289 
    Details
    ISSN: 1588-2837
    Keywords: Enthalpy ; chain propagation ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A calculation of the enthalpies of elementary steps of the intra- and intermolecular chain propagation for model oxidation reactions of ethers, esters, ketones and hydrocarbons has been carried out. The heats of the intermolecular and intramolecular transfer of free valence with participation of peroxy radicals and C−H bond of the oxygen-containing compounds are shown to be comparable.
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    Effect of vitrification method on the formation of deep traps for gas molecules inn-butanol glass (1999)
    Springer
    Reaction kinetics and catalysis letters 68 (1999), S. 325-330 
    Details
    ISSN: 1588-2837
    Keywords: vitrification ; glass structure ; oxidation ; solid phase kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The capture of oxygen molecules by deep traps during oxygen diffusion in butanol glasses has been studied at 77 K as the kinetics of thetert-butyl radical oxidation. Slow glass formation in the samples increases the concentration of deep traps in the matrix. The total value of nonrelaxed free volume has no effect on the concentration of deep traps. It is assumed that trap formation is due to the formation of certain molecular structures below room temperature, most probably, with dissolved gas molecules.
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    Oxidation of 1,3-pentadiene on vanadium containing HZSM-5 (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 169-175 
    Details
    ISSN: 1588-2837
    Keywords: 1,3-pentadiene ; oxidation ; vanadyl ion ; HZMS-5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Different methods and vanadium compounds have been used to carry out proton exchange of zeolite HZSM-5 by vanadium cations. The catalysts are characterized by specific surface area, XRD, IR spectroscopy and TPD of ammonia. The catalysts’ activity in the oxidation of 1,3-pentadiene and the selectivity to carbonyl compounds are compared.
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    Non-stationary kinetic model for deep oxidation of aromatic hydrocarbons on oxide catalysts (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 63-70 
    Details
    ISSN: 1588-2837
    Keywords: Non-stationary kinetics ; alkylbenzene ; oxidation ; oxide catalysts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A non-stationary kinetic model for deep oxidation of aromatic hydrocarbons based on the fragmentation theory approach is proposed. The model is simple and provides qualitative adequacy and good quantitative description of experimental results.
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    URL: http://dx.doi.org/10.1007/BF02475742
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    Kinetics of oxidation of diols by ozone in aqueous solution (1999)
    Springer
    Reaction kinetics and catalysis letters 68 (1999), S. 237-242 
    Details
    ISSN: 1588-2837
    Keywords: Diols ; oxidation ; ozone ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of the oxidation of diols by ozone was investigated by a spectrophotometric method in the temperature interval of 277–304 K. The activation parameters of the reaction were determined.
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    URL: http://dx.doi.org/10.1007/BF02475507
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    Kinetics of oxidation of aliphatic alcohols by ozone in aqueous solutions (1999)
    Springer
    Reaction kinetics and catalysis letters 68 (1999), S. 257-263 
    Details
    ISSN: 1588-2837
    Keywords: Alphatic alcohols ; oxidation ; ozone ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of oxidation of aliphatic alcohols by ozone in aqueous solutions was investigated in the temperature interval of 292–317 K. The activation parameters of the reaction were determined. The dissociation energies of CH-bonds of the studied substrates were calculated with the use of the AM1 semiempirical method.
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    P−Mo−V heteropoly acids as catalysts for oxidation of 2,6-dialkylphenols to the corresponding 2,6-dialkyl-1,4-benzoquinones by molecular oxygen (1999)
    Springer
    Reaction kinetics and catalysis letters 68 (1999), S. 339-346 
    Details
    ISSN: 1588-2837
    Keywords: Heteropoly acids ; dialkylquinones ; preparation ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new method is proposed for synthesis of 2,6-dialkyl-1,4-benzoquinones by oxidation of 2,6-dimethyl and 2,6-di-tert-butylphenols with oxygen in a two-phase “water-organic” system in the presence of P−Mo−V heteropoly acids.
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    Role of protons in methyl phenyl sulfide oxidation with hydrogen peroxide catalyzed by Ti(IV)-monosubstituted heteropolytungstates (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 311-317 
    Details
    ISSN: 1588-2837
    Keywords: Mechanism ; oxidation ; methyl phenyl sulfide ; hydrogen peroxide ; titanium-substituted heteropolytungstates ; peroxo complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Acid tetrabutylammonium salts of Ti(IV)-monosubstituted heteropolytungstate, PW11TiO40 5−, show high catalytic acitivity in the oxidation of methyl phenyl sulfide with hydrogen peroxide, while the corresponding tetrabutylammonium salts containing no protons are poor catalysts for this reaction.
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    URL: http://dx.doi.org/10.1007/BF02475806
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    Oxidation of alcohols using clay-supported potassium peroxodiphosphate (1999)
    Springer
    Reaction kinetics and catalysis letters 66 (1999), S. 245-249 
    Details
    ISSN: 1588-2837
    Keywords: Montmorillonite clay ; peroxodiphosphate ; oxidation ; benzylic alcohols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Clay-supported potassium peroxodiphosphate efficiently oxidizes benzylic alcohols to the corresponding aldehydes without overoxidation to acids. H3P2Og − as the active species.
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    Catalytic oxyfunctionalization of alkanes by manganese and ruthenium clusters (1999)
    Springer
    Reaction kinetics and catalysis letters 67 (1999), S. 83-88 
    Details
    ISSN: 1588-2837
    Keywords: Manganese/ruthenium catalysts ; oxidation ; alkanes ; tert-butyl hydroperoxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Di- and trinuclear clusters of manganese and ruthenium were used as catalysts in the oxidation of alkanes in the presence oftert-butyl hydroperoxide as oxidant. The investigations reveal marked differences in the reactivity of the manganese and ruthenium catalysts though structurally they have similar coordination environment. The probable mechanism of hydroxylation in these systems is discussed.
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    13C and1H NMR spectroscopic characterization of titanium(IV) alkylperoxo complexes Ti(OOtBu)n(OiPr)4−n with n=1, 2, 3, 4 (1999)
    Springer
    Reaction kinetics and catalysis letters 67 (1999), S. 359-364 
    Details
    ISSN: 1588-2837
    Keywords: Mechanism ; oxidation ; alkylperoxo complexes of titanium(IV) ; 13C NMR spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Using13C and1H NMR spectroscopy, titanium(IV) alkylperoxo complexes Ti(OOtBu)n(OiPr)4−n with n=1, 2, 3 and 4 were characterized in the reaction of Ti(OiPr)4 withtBuOOH in CH2Cl2 and CDCl3.
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    Structure/function studies of S100A8/A9 (1999)
    Springer
    International journal of peptide research and therapeutics 6 (1999), S. 359-369 
    Details
    ISSN: 1573-3904
    Keywords: chemotaxis ; inflammation ; oxidation ; post-translational ; S100
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The functional importance of members of the S100 Ca2+-binding protein family is recently emerging. A variety of activities, several of whcih are apparently opposing, are attributed to S100A8, a protein implicated in embryogenesis, growth, differentiation, and immune and inflammatory processes. Murine (m) S100A8 was initially described as a chemoattractant (CP-10) for myeloid cells. It is coordinately expressed with mS100A9 (MRP14) in neutrophils and the non-covalent heterodimer is presumed to be the functional intracellular species. The extracellular chemotactic activity of mS100A8, however, is not dependent on mS100A9 and occurs at concentrations (10−13-10−11 M) at which the non-covalent heterodimer would probably dissociate. This review focuses on the structure and post-translational modifications of mS100A8/A9 and their effects on function, particularly chemotaxis.
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    URL: http://dx.doi.org/10.1007/BF02443433
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    Structure/function studies of S100A8/A9 (1999)
    Springer
    International journal of peptide research and therapeutics 6 (1999), S. 359-369 
    Details
    ISSN: 1573-3904
    Keywords: chemotaxis ; inflammation ; oxidation ; post-translational ; S100
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The functional importance of members of the S100 Ca2+-binding protein family is recently emerging. A variety of activities, several of which are apparently opposing, are attributed to S100A8, a protein implicated in embryogenesis, growth, differentiation, and immune and inflammatory processes. Murine (m) S100A8 was initially described as a chemoattractant (CP-10) for myeloid cells. It is coordinately expressed with mS100A9 (MRP14) in neutrophils and the non-covalent heterodimer is presumed to be the functional intracellular species. The extracellular chemotactic activity of mS100A8, however, is not dependent on mS100A9 and occurs at concentrations (10-13–10-11 M) at which the non-covalent heterodimer would probably dissociate. This review focuses on the structure and post-translational modifications of mS100A8/A9 and their effects on function, particularly chemotaxis.
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    URL: http://dx.doi.org/10.1023/A:1008971021016
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