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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Integral equations and operator theory 3 (1980), S. 515-528 
    ISSN: 1420-8989
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In [4] I. Gohberg and M.A. Kaashoek formulated the question how the partial multiplicities of the product AB of two holomorphic matrix (or operator) functions are related to those of the factors A and B. E.I. Sigal presented a set of necessary relations in [7], and recently L. Rodman and M. Schaps ([6]) obtained another set of relations which must hold. Here we prove a generalization of Sigal's rules which form a proper superset of the rules obtained by Sigal, Rodman and Schaps. Unlike Rodman and Schaps we formulate all results for matrix functions of fixed nxn-size; this leads to another set of relations which are derived for fixed n at first; however, we prove that such rules must hold independently of n, once they are derived for fixed n. Finally we show that this new set of relations completely determines the case of 3×3-matrices.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Integral equations and operator theory 1 (1978), S. 567-579 
    ISSN: 1420-8989
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract It is proved that on a simply connected region the solutions of the elliptic partial differential equation $$(A_o \frac{{\partial ^s }}{{\partial x^s }} + A_1 \frac{{\partial ^s }}{{\partial x^{s - 1} \partial y}} + \ldots + A_{s - 1} \frac{{\partial ^s }}{{\partial x\partial y^{s - 1} }} + \frac{{{\rm I}\partial ^s }}{{\partial y^s }} ) U(x, y) = 0$$ have representations U(x,y) = QV(x,y), where V admits local power series expansion in the "operator variable" xI + yI and (Q,T) forms a standard pair for the monic operator polynomial A0 + λA1 + ⋯ + λs-1As-1 + λsI.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Integral equations and operator theory 3 (1980), S. 23-42 
    ISSN: 1420-8989
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Integral equations and operator theory 3 (1980), S. 1-22 
    ISSN: 1420-8989
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Let X be a Banach space, J $$ \subseteq $$ L(X) a Fréchet ideal and G a region in ℂN. If J is non-locally-convex, then it is a problem whether A ∈H(G,L(X)), B ∈H(G,J) implies A·B,B·A ∈H(G,J). A positive answer to this question would sharpen an additive decomposition theorem of B. Gramsch [6] and B. Gramsch-W. Kaballo [8] for resolvents of semi-Fredholm functions. Here it is proved that if J is contained in another ideal J1 such that the inclusion map i : J → J1 is the product of N exponentially galbed maps in the sense of P. Turpin [18], [19], then A·B,B·A ∈H(G,J1). An example shows that this is false if i is only a product of N-1 exponentially galbed maps. Thus a sharpening of the decomposition result mentioned above is obtained. Finally, for N=1, a sharper version of a multiplicative decomposition theorem of G.Ph.A. Thijsse [17] for FG-meromorphic functions is proved.
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  • 5
    ISSN: 1572-9699
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Antonie van Leeuwenhoek 29 (1963), S. 89-100 
    ISSN: 1572-9699
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pseudomonas aeruginosa cells pre-grown on a particular hydrocarbon will oxidize other hydrocarbons as well. Degradation of these hydrocarbons proceeds to a point — depending on their structure — where new enzymes are needed for further degradation. Lack of these enzymes causes accumulation of products. However, secondary adaptation processes tend to decrease yields of intermediates, in particular when adaptation rates are high. By inhibiting these secondary adaptation processes with chloramphenicol (CAM), the amounts of various intermediates could be increased. Propionic acid was accumulated from heptane by hexane-grown cells in yields up to 60% (molar) calculated on heptane converted. The effect of CAM suggests that propionic acid is not subject to β-oxidation (acrylate pathway) but is degraded via methylmalonate by adaptive enzymes. 2-Methylhexane was converted for 30–40% (molar) intoiso-valeric acid by heptane-grown cells. A known pathway ofiso-valeric acid oxidation incorporates a carbon dioxide fixation step, and lack of this enzyme in heptane-grown cells probably causesiso-valeric acid accumulation. Heptene-1 incubation with heptane-grown cells resulted in a 30–40% conversion into 4-pentenoic plus 2, 4-pentadienoic acids. 6-Heptenoic acid was detected occasionally. A predominant attack at C7 of the heptene-1 molecule is indicated at least for heptane-grown cells. Attack on the saturated end of the molecule seems well in line with the assumption that alkane oxidation by these bacteria is effected by oxygen transferring enzymes operating on a methyl group, as opposed to the action of a dehydrogenase and formation of an α-olefin as the intermediate.
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  • 7
    facet.materialart.
    Unknown
    In:  Blumea - Biodiversity, Evolution and Biogeography of Plants (0006-5196) vol.30 (1984) nr.1 p.89
    Publication Date: 2015-03-06
    Description: In Southeast Asia (excluding India) 44 taxa are recognized, 39 species, of which four are newly described ( I. kerrii, I. luzoniensis, I. emmae, and one unnamed species A, which will be treated by Nguyen Van Thuan, Paris), four subspecies, one of which is new (I. sootepensis subsp. acutifolia) and three are new combinations ( (I. suffruticosa subsp. guatemalensis, I. trifoliata subsp. unifoliata, I. trita subsp. scabra) ), and one variety which is a new combination I. spicata var. siamensis). A key, descriptions and full synonymy are given as well as 4 distribution maps and 5 figures.
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
    Format: application/pdf
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  • 8
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    Unknown
    Naturalis Biodiversity Center
    In:  Blumea: Biodiversity, Evolution and Biogeography of Plants vol. 66 no. 3, pp. 263-274
    Publication Date: 2024-01-12
    Description: One of the objects of the Municipal Museum Zierikzee (Province of Zealand, The Netherlands) is a \nhistorical herbarium referred to by the name the \xe2\x80\x98Zierikzee Herbarium\xe2\x80\x99. The characteristics of the specimens in the \nZierikzee Herbarium are so similar to those in a herbarium at Naturalis Biodiversity Center, Leiden (L), that both must \noriginate from the same place and time. About the latter herbarium little is known, except that it was once owned by \nthe army-surgeon Simon(e) d\xe2\x80\x99Oignies (1740\xe2\x80\x931782). The Zierikzee Herbarium was recently described and analysed \nin detail by Offerhaus et al. (2021). It is hypothesised that the Zierikzee Herbarium is part of a herbarium made by \nProfessor Martinus Wilhelmus Schwencke (1707\xe2\x80\x931785) and was used during his lectures for future pharmacists \nin his botanical garden in The Hague in the 1750s, and auctioned in Leiden in 1785. The presence in the Zierikzee \nHerbarium of a virtually complete set of medicinal plants mentioned in the \xe2\x80\x98Pharmacopoea Hagana\xe2\x80\x99 (Anonymous \n1738) eventually led to the conclusion that these could not have been assembled before 1730. Based on the \nprinted ornaments that are used to mount the plants in these, and the major Dutch herbaria of the 18th century, \nI argue that the plants in the Zierikzee Herbarium and the herbarium of D\xe2\x80\x99Oignies were remounted at a later date. \nThe hypothesis by Offerhaus et al. (2021: 12) that the Zierikzee Herbarium was started between 1710 and 1720 is \nrejected. Arguments are given why it is unlikely that the Zierikzee Herbarium, as is suggested by Offerhaus et al. \n(2021: 12), is the herbarium of the head gardener of the Leiden botanic garden, Jacob Ligtvoet (1684\xe2\x80\x931752) and \nwas auctioned in 1752.
    Keywords: Plant Science ; Ecology ; Evolution ; Behavior and Systematics ; 18th century Dutch herbaria ; Jacob Ligtvoet ; Pharmacopoea Hagana ; printed herbarium ornaments ; Martinus Wilhelmus Schwencke
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 9
    facet.materialart.
    Unknown
    In:  Blumea: Biodiversity, Evolution and Biogeography of Plants vol. 30 no. 1, pp. 89-151
    Publication Date: 2024-01-12
    Description: In Southeast Asia (excluding India) 44 taxa are recognized, 39 species, of which four are newly described ( I. kerrii, I. luzoniensis, I. emmae, and one unnamed species A, which will be treated by Nguyen Van Thuan, Paris), four subspecies, one of which is new (I. sootepensis subsp. acutifolia) and three are new combinations ( (I. suffruticosa subsp. guatemalensis, I. trifoliata subsp. unifoliata, I. trita subsp. scabra) ), and one variety which is a new combination I. spicata var. siamensis). A key, descriptions and full synonymy are given as well as 4 distribution maps and 5 figures.
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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