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By a comparative thin layer chromatographic screening of the methanol-soluble leaf exudates from more than 400 Aloe plants (183 species), 5-hydroxyaloin A was identified in 20 species. Whilst 13 of the 20 species revealed interindividual variations concerning to the occurrence of 5-hydroxyaloin A, this anthrone-C-glucosyl was unambiguously detected in each individual of 6 Aloe species. In the leaf exudates from A. marlothii Berger 5-hydroxyaloin A was only traceable in the aloin-containing chemivars. The complete anthrone-C-glucosyl pattern of these 7 clearly characterized species has been determined additionally by qualitative and quantitative high performance liquid chromatography: The results obtained demonstrate that 5-hydroxyaloin only occurs in the more stable A-configuration (10 R, 1′S), thus being till now the only anthrone-C-glycosyl which has not been found as diastereomeric pair genuinely in plants. As well, 5-hydroxyaloin A characterizes a quantitatively significant hydroxylating pathway in biosynthesis of anthranoids. It is discussed as a chemotaxonomic marker of the genus Aloe, especially of the sections Pachydendron and Eualoe.
Formation of major prenylquinones and carotenoids was investigated by comparing the incorporation of [14C]mevalonate into segments of different age from green and etiolated leaves of 22 C-grown rye seedlings (Secale cereale L.) and from 32 C-grown rye leaves which contained bleached and proplastid-like ribosome-deficient plastids, due to a heat-sensitivity of 70S ribosome formation. The contents of plastidic isoprenoids were much lower (between 2 - 30%) in the achlorophyllous than in green leaves. In green leaves [14C]mevalonate incorporation into non-polar lipids and into plastoquinone was partially inhibited in the presence of gabaculin, an inhibitor of chlorophyll synthesis. However, except for β-carotene, [14C]mevalonate incorporation into isoprenoids continuously increased with age also in achlorophyllous etiolated or 32 °C-grown, as in green, leaves and was, except for P-carotene and plastoquinone, higher in etiolated than in green leaves. In bleached °32 C-grown leaves [14C]mevalonate incorporation into all plastidic isoprenoids was strikingly (up to 45-fold) higher than in green control leaves. While degradation of P-carotene was greatly enhanced in bleached 32 °C-grown leaves, relative to green control leaves, and could thus compensate for a higher apparent synthesis, chase experiments did not reveal any marked differences of the turnover of other isoprenoids. The half times of plastoquinone. phylloquinone and lutein were in the order of 2-3 days. Within a 24 h chase period a-tocopherol degradation did not become apparent. Uptake of [14C]mevalonate and [14C]isopentenyl pyrophosphate by isolated bleached plastids from 32 °C-grown leaves was much more rapid than by chloroplasts and resulted in higher precursor accumulation within the organelle. While mevalonate incorporation into isoprenoid lipids was not detected, isopentenyl pyrophosphate was incorporated into isoprenoid lipids, including plastoquinone. Rates of incorporation by isolated chloroplasts or bleached plastids were of similar order. The results illustrate that divergent types of plastid differentiation are associated with fundamental developmental changes of the metabolic flow of isoprenoid precursors between different products and compartments and, in particular, with changes of import into the plastid compartment.
The radiative lifetimes of the C3Il-X3II transition of the CSi radical have been calculated from highly correlated electronic wavefunctions and compared with available experimental data. For this transition, the Franck-Condon approximation fails due to the strong R-dependency of the transition moment function.
The reading of Kafka's "Metamorphosis" that I propose on the following pages is based on two assumptions that are derived from widely divergent approaches to Kafka's writings. The first is the offspring of psychological interpretation and recognizes that homologous unconscious strategies are operative in the "Letter to his father" and Kafka's tale. Josef Rattner, writing about the "Ur-Situationen", the "primal situations" that Kafka experienced as a child and which produced in him his most basic psychological attitudes (Rattner calls them Grundhaltungen), concludes: "Kafka's life is an incessant attempt to cope with his father-experience. His father is at the base of his anxiety of life and his crippling hypochondria. … Sadism and masochism are distinctive features of Kafka's works."
In his lifetime Daniil Charms only succeeded in publishing two of his poems for adults. Publicly he was a children's author: a job in the Soviet Union which traditionally attracted many writers whose literature for adults was either rejected by the official literary system or had to be hidden altogether if its creators wanted to avoid trouble.
In fact up to the present day it is still Charms the children's author who is best known and loved, although finally under new historical and political conditions the writer for adults has also been allowed to make his debut. However, whatever he wrote, Charms' work was always dominated by an absurdist world view, a view that usually denied all dogma or ideology. His only aim seems to have been to present a world upside down and play around with literary and other conventions, i.e. more than anything else he wanted to be different, acting as a sort of literary "punk".
Although Charms and his associates were preceded by European absurdist authors, such as A. Jarry (1873-1907), it is very difficult to establish any relationship of influence between examples of Western European absurdism and Daniil Charms. Nonetheless, Charms' work, as well as that of Jarry, Ionesco and Beckett, all share the "grotesquely comic as well as irrational" (Abrams 1981: 1) quality of the absurdist movement in its larger modernist context.
This species is very variable in form, and Jones (1977) reduced the above-cited four species to synonymy of R. appressa. Jones (1977) cited “it is likely that R. appressa will prove to be identical with R. javanica Gottsche. ....” However, R. appressa differs from R. javanica in many characters. In general appearance, R. appressa resembles R. reflexa known from SE Asia.
Widely distributed holarctic species, extending to Africa, South America and Tasmania. In
Africa known from the Azores, Madeira, Canary Is., central African mountains, Réunion, Natal and Cape, and also from Marion I., Crozet I. and Tristan da Cunha. In the area it occurs in the subalpine belt from 2500 to 3560 m, on soil and rocks.
The total number of currently accepted species of Cladoniaceae in the Hawaiian Islands is 22. Several taxonomic problems still exist, however. The effects of isolation are clear among Cladoniaceae. Endemism is high (c. 40%); and, the number of species low. The species must have reached the archipelago via long-distance trans-oceanic dispersal, probably aided by the abundant production of lichen propagules, such as soredia and microsquamules. Although most of the species found in Hawaii are widely distributed, the Hawaiian Cladoniaceae show slight affinities to those of E and SE Asia. Cladonia polyphylla Mont. & v.d. Bosch is an older name for C. fruticulosa Krempelh., and is lectotypified from authentic material. C. leprosula H. Magn. is included in C. ochrochlora Flörke.
If a species is not listed in Kis (1985) for a specific country, nor present in the literature cited below for a special genus or species, I have given that species an indication: new for a country (*). When for a species or group of taxa no special literature is cited, the identification can usually (also) be made with Magill (1981). If a remark is given on the distribution in (C.) Africa, also material seen from institutes and private herbaria was considered.
Lichens from Mount Kinabalu
(1993)
286 species of lichenized fungi on Mount Kinabalu are recorded by field survey and investigation of literature records and herbarium material. An annotated catalogue is presented, together with habitat notes, and a list of collectors. The summit area has a saxicolous lichen flora of boreal affinities, while the lower zones are more closely related to other SE Asian mountains. Eleven species appear to be restricted to the mountain, and four new species are described: Phaeographis kinabalensis, Stereocaulon granulans, Pertusaria epitheciifera and Thelotrema subweberi.
Plants glaucous green, in loose to dense turfs; stems sparingly branched; leaves lanceolate from a broad to narrow base, slightly to strongly keeled, + overlapping when dry, slightly spreading when moist, acuminate, acute apiculate to truncate-retuse and revolute; hyaline lamina occupying 1/5-1/3 length of leaves; hyalocysts quadrate, oblong rectangular to hexagonal in 1- 3(-4) layers on the abaxial and adaxial sides of the central chlorophyllous layer; costa narrow or broad, spinose at apex or smooth; margins serrate to smooth.
Vanden Berghen (1948) who himself described two new species (1951, 1953) and supplied a key for the Central African taxa (Vanden Berghen 1960). Kuwahara described Metzgeria agnewii from the Aberdare Mts. in Kenya (1973), established the classification of subgeneric taxa (1978) and synonymized several African taxa with other known species (1986), so the known distribution of several African Metzgeria considerably widened.
The first species list of the examined countries was published by Demaret (1940,1946) and the revision of the Syrrhopodon species of this area were made by Demaret and Leroy (1947). Further additional data were published on the basis of the collection of S. Lisowski (Orbán 1987). The tropical African species of the genera were revised by the Author (Orbán 1981) and later the key for the species was prepared by Orbán and Reese (1986). This key is suitable to identify practically all tropical African taxa, therefore I do not supply a key here for the 7 species collected in Central Africa. The world ranges of Syrrhopodon species was given by Reese (1987).
For worldwide monograph see Bremer (1980a, b, 1981). Unfortunately, this treatment is not particularly useful because the author accepted an exceedingly broad species concept and actually very many distinct and easily recognizable exotic species has simply been lumped with S. apocarpum (Hedw.) Bruch & Schimp. in B., S. & G. In tropical East Africa at least five distinct species have so far been recorded (Kis 1985), but it is very likely that this number will increase with progress in taxonomic study of the genus and floristic exploration of the bryologically undercollected areas.
Adistinct species easily recognized by the long exserted, narrow cylindric capsules. The peristome has 8 teeth and 8 segments which distinguishes this taxon from the closely related O. firmum. They both belong to the section Leiocarpa within the subgenus Phaneroporum. Species closely related to the two African taxa are common throughout the Southern Hemisphere. Orthotrichum arborescens is an epiphyte reported from Arundinaria alpina, giant Senecio and Philippia. It is an alpine species occuring between 2.500 and 4.000 m altitude. The geographic distribution is restricted to Central East Africa.
The specimen represents a rather typical African form of this taxon. The marginal teeth of the leaf are small and the leaf cells near isodiametric, but on the basis of the clearly differentiated juxtacostal cells, the specimen belongs to var. rhynchophyrum. Two other tropical African species are Plagiomnium cuspidatum (Hedw.) T. Kop. and P. undulatum (Hedw.) T. Kop. which differ by having an acute or cuspidate leaf apex, which in P. rhynchophorum tends to be emarginate and apiculate, and having sharper and larger projecting marginal teeth on their leaves. The distribution of P. rhynchophyrum is mapped and African specimens listed in Koponen (1981).
The Bryotrop project was planned in 1981 by several bryologists from Germany. Aim of this project was a comparative study of the bryoflora and -vegetation of rain forest areas in different parts of the tropics. In contrast to other bryological research in the tropics, this project should not be limited to pure floristic studies at various collecting sites but consist of interdisciplinary work of researchers from different fields together in a small region, an attempt which was not made before in bryology.
Since Stephani (1911, 1916) described this species from “Kiwu See” in “Ruanda”, no records of the species have been published. This is the second record for the species. A. myriandroecium is easily recognized by its deeply forked, strap-shaped thallus whose margins are densely dissected into narrow-rectangular lobules, and its globose, large spores whose distal surfaces are covered with numerous, long baculate outgwoths. It occurs on roadcut in Ericaceous heath on the drier slopes of valley at about 2500 m altitude.
Procumbent to ascendent, with terminal branching irregular and usually infrequent (sometimes even lacking). Midrib of well-developed fronds never more than 1/3 of frond width Androecial scales (in the local species) on each side of midrib, the latter remaining free of scales (or with a few at proximal and distal end of androecium).
Thirteen new records of species of Andreaea, Trematodon, Campylopus and Rhabdoweisia for Rwanda viz. Zaire are published. Campylopus cerradensis Vital and Paraleucobryum longifolium (Hedw.) Loeske ssp. brasiliense (Broth.) P. Müller & J.-P. Frahm, previously only known from Brazil, are reported for Africa for the first time. Campylopus schmidii C. Müll. is reported for the first time for the African continent. Campylopus leucochlorus is regarded as synonymous with C. hildebrandtii (C. Müll.) Jaeg. Atractylocarpus capillifolius Dix. is regarded as synonymous with A. alticaulis (Broth.) Williams. Based on a different spore size, spore ornamentation and growth form as well as cultivation experiments, Antitrichia kilimandscharica Broth. is regarded as separate species and not as synonymous with A. curtipendula (Hedw.) Brid. Acrocryphaea robusta Broth. in Mildbr. is combined new to the genus Schoenobryum.
A survey of the families Trichocoleaceae, Geocalycaceae, Acrobolbaceae, Balantiopsidaceae, Lepidoziaceae (Telaranea, Arachniopsis), Calypogeiaceae, Adelanthaceae, Porellaceae, Jubulaceae, Marchantiaceae (Dumortiera) (Hepaticae) and Polytrichaceae (Musci) for Central Africa (Zaire and Rwanda) is presented. Leptoscyphus infuscatus, Tylimanthus ruwenzoriensis, Calypogeia fissa, Adelanthus lindenbergianus and Porella subdentata are recorded as new to Rwanda. Telaranea trifida and Calypogeia fusca are new to Zaire. Leptoscyphus hedbergii and Calypogeia afrocaerulea are new records for Zaire and Rwanda.
During the BRYOTROP-Expedition in 1991, 71 collecting sites could be visited. These are situated in the Kahuzi-Biega-National Park/Zaire, the Nyungwe Forest and the Virunga volcanoes/Rwanda. This paper provides a short description of the vegetation in these three areas and a detailed list of all collecting sites.
A short survey of the bryological exploration of Rwanda and Zaire is provided. The first to collect bryophytes in the area was Stuhlmann in 1891 on Ruwenzori. The first bryological collections from Rwanda were made by Mildbraed in 1907. In 1929 Humbert made the first gatherings on Mt. Kahuzi and Mt. Biega. Since then a lot of botanist have collected mosses and liverworts so that Rwanda and eastern Zaire can be regarded as well known. From most parts of Zaire and from Burundi however only few data are hitherto available.
A check-list of the Hepaticae and Anthocerotae from Central Africa (Zaire, Rwanda, Burundi) is presented. 267 liverwort species and 4 hornworts are recognized for the area. For Zaire 215 Hepaticae and 3 species of Anthocerotae are recorded. In Rwanda 150 liverworts and one hornwort have been found. Burundi is far less known and only 48 Hepaticae are recorded.
Neckera submacrocarpa may be recognized by the numerous paraphyllia to ca. 2 mm long, and distally rugose perichaetial leaves. According to De Sloover (1977), it occurs in montane forests and Senecio heaths between 2 400 and 3 650 m. The present material was collected between 3 400 and 3 700 m; one specimen was growing on rotten wood and the others on Senecio. Neckera submacrocarpa is endemic to Africa, being mainly distributed on the mountains of East Africa (Uganda, Kenya, Tanzania, Zaire, Rwanda). A disjunct occurrence is located on Mt. Cameroon.
Six species and one variety of Sphagnum have been recorded from Rwanda and Zaire. Three of these were collected during the BRYOTROP field studies and are annotated below. A key is given to all the species known to occur in the region with the addition of one extra species (S. truncatum Hornsch.) which is likely, on ecological and distributional grounds, to be found there in the future. Authorship and complete synonymies are given in Eddy (1985).
This very distinctive and easily recognized moss has terete foliation when dry, and has leaves spreading when moist. The leaves are ovate, abruptly broad-acuminate, about 1.5-2 mm long, and strongly plicate. The single costa extends to the base of the acumen, and the laminal cells are 1-2(-3):1 and low unipapillose.
For locality data and a description of the collecting sites see the contribution by E. Fischer on the vegetation of the study area in this volume (Tropical Bryology 8: 13-37, 1993). The specimens are deposited at the Botanical MuseumBerlin (B) as well as in the herbarium of the author (except for unicates).
Central Africa was one of the first regions in the tropics, if not the first, for which a checklist of mosses was compiled. In 1940, Demaret published the "Prodrome des Bryophytes du Congo Belge et du Ruanda-Urundi", followed by a supplement in 1946. In the 50 years since that time, numerous new contributions to the bryophyte flora of Central Africa have been made. Demaret added seven more publications on Zaire (formerly Belgian Congo). Potier de la Varde studied the bryophyte collections made during the surveys of the flora of the Central African volcanoes by Hedberg.
Taxonomic results of the Bryotrop expedition to Zaire and Rwanda : 6., Aytoniaceae, Marchantiaceae
(1993)
A subspecies known with certainty only from Europe. Its electrophoretic pattern separates it clearly from the other subspecies of M. polymorpha , but its morphological characteristics are not clearly distinctive (Boisselier & Bischler 1989) . However, the tropical African specimens from Kenya and Tanzania, together with those of Rwanda, probably belong to this subspecies. It grows on wet soil in Senecio refractisquamata paramo and on cliffs in Hagenia- Dombeya forests, between 2700 and 3600 m. M. polymorpha has not yet been recorded from Rwanda.
Lecanora leprosa and L. sulphurescens are two commonly misidentified pantropical lichens. A detailed circumscription is presented to help overcome such difficulties. Both species contain a chemosyndrome of chlorodepsidones based on gangaleoidin. The new depsidone chlorolecideoidin (methyl 2,4,9-trichloro-3,8-dihydroxy-1,6-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]-dioxepin- 7-carboxylate) has been shown to be a minor component of both species.
Upon examination of type material, the following new synonymies are proposed: Macromitrium altituberculosum Bartr. with M. carionis C. Muell.; M. aureum C. Muell. with M. longifolium (Hook.) Brid.; M. crumianum Steere & Buck with M. leprieurii Mont.; M. semimarginatum C. Muell. with Groutiella chimborazense (Spruce ex Mitten) Florsch.; M. standleyi Bartr. var. subundulatum Bartr. with M. fulgescens Bartr. In addition, the following synonymies were confirmed: M. brevipes C. Muell. with Groutiella apiculata (Hook. & Grev.) Crum & Steere; M. sartorii C. Muell. with M. punctatum (Hook. & Grev.) Brid. Floristic reports include M. leprieurii new to Dominica, Guadeloupe, and Panama, and M. ulophyllum Mitten is reported for the first time from Central America (Panama) and Venezuela. A complete description including illustration is provided for the first time for the latter species. Lectotypes are chosen for all types examined.
Bibliographic records are presented of 324 scientific papers on foliicolous lichenized fungi published subsequent to Santesson’s survey of 1952. The 482 species presently known are listed in an alphabetical checklist, with references to important descriptions, keys and illustrations published by or after Santesson (1952), and an indication of the distribution. Also added are all synonyms used after 1952. Introductory chapters deal with the present state of research on foliicolous lichens and its history. The following new combination is proposed: Strigula smaragdula Fr. var. stellata (Nyl. & Cromb.) Farkas.
Thirty-seven species of mosses are reported from the Mascarenes and three are republished under new names. Didymodon michiganensis (Steere) K. Saito is new to Africa. Campylopus bartramiaceus (C. Muell.) Thér., Pogonatum proliferum (Griff.) Mitt. and Zygodon intermedius B.S.G. are new to the Mascarenes. Calymperes palisotii ssp. palisotii Schwaegr. is new to Mauritius.
The West Indies have strong continental affinities, but the strongest are with South America, not Central America as was once thought. Moss diversity is the result of migration after the Miocene; the patterns of distribution involving the West Indies and South or North America indicate both migration as well as floristic flows through the Antillean Arc. Speciation due to selective pressures in the changing climate of the Pleistocene gave rise to endemic taxa, but paleoendemics may have resulted in a previous archipelago condition.
Field and herbarium studies of the lichen family Cladoniaceae in the states of Paraíba, Pernambuco and Sergipe, Northeast Brazil, yielded 22 species, many of them being new reports for the region. The phenolic compounds identified in each species are reported. Cladonia clathrata Ahti & Xavier Filho, Cladonia polita Ahti, Cladonia polyscypha Ahti & Xavier Filho, and Cladonia rugicaulis Ahti are described as new. C. clathrata, C. rhodoleuca Vainio, C. rugicaulis, C. salzmannii Nyl., and C. subminiata Stenroos appear to represent an element confined to northeastern Brazil.
It is well known that artificial neural nets can be used as approximators of any continuous functions to any desired degree and therefore be used e.g. in high - speed, real-time process control. Nevertheless, for a given application and a given network architecture the non-trivial task remains to determine the necessary number of neurons and the necessary accuracy (number of bits) per weight for a satisfactory operation which are critical issues in VLSI and computer implementations of nontrivial tasks. In this paper the accuracy of the weights and the number of neurons are seen as general system parameters which determine the maximal approximation error by the absolute amount and the relative distribution of information contained in the network. We define as the error-bounded network descriptional complexity the minimal number of bits for a class of approximation networks which show a certain approximation error and achieve the conditions for this goal by the new principle of optimal information distribution. For two examples, a simple linear approximation of a non-linear, quadratic function and a non-linear approximation of the inverse kinematic transformation used in robot manipulator control, the principle of optimal information distribution gives the the optimal number of neurons and the resolutions of the variables, i.e. the minimal amount of storage for the neural net. Keywords: Kolmogorov complexity, e-Entropy, rate-distortion theory, approximation networks, information distribution, weight resolutions, Kohonen mapping, robot control.