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A number of new moenomycin A derivatives have been prepared. Their antibiotic properties highlight the very specific recognition of moenomycin A at the transglycosylase binding site which is the basis of the transglycosylase inhibiting property of moenomycin A (4a).

This paper reviews the origin, nature, systematic distribution, and the respective function of the highly variable and diverse thread-forming structures in angiosperm anthers (including somewhat similar, rare features in ferns and gymnosperms). On one hand, such threads may function as pollen-connecting vectors in forming pollen dispersal units, as sporopollenin threads (viscin threads), e.g. in Onagraceae, or sporopollenin-less threads in surprisingly many other angiosperm families. On the other hand, as is known from the Impatiens — “pollen basket”, threads or ropes may be involved in pollen presentation. In addition, for the first time two new examples of “pollen baskets” in Boraginaceae and Scrophulariaceae are reported. In Echium the basket is formed by cellular elements from the modified septal regions, whereas in Esterhazya a similar effect is achieved in an analogous manner by trichomes of the epidermal layer of the thecal wall. There is obviously a different function of these seemingly very similar baskets: in Echium the feature acts preferably as a pollen presentation agent, whereas in Esterhazya the primary function is to prevent all the pollen from being dispersed too soon.

DNA-encoding of solid nanoparticles requires surfacechemistry,which is often tedious and not generallyapplicable. In the present study non-covalently attachedDNA are used to assemble soft nanoparticles(liposomes) in solution. This process displaysremarkably sharp thermal transitions from assembledto disassembled state for which reason this methodallows easy and fast detection of polynucleotides (e.g.DNA or RNA), including single nucleotidepolymorphisms as well as insertions and deletions.

DNA detection systems based on encoded solidparticles have been reported but require often tediousand not generally applicable surface chemistry. In thepresent study a system comprised of a lipid-modifiedDNA probe sequence and unmodified DNA targetsequences is used to non-covalently assemble liposomes.The process results in large liposome aggregates withdramatically different optical properties compared toindividual liposomes in solution. The presented methodenables fast and easy detection of target polynucleotides.Furthermore, the system displays remarkably sharpthermal transitions which enable detection of singlenucleotide polymorphisms with greatly enhancedresolution compared to flourescence based methods.

As the plant taxonomist Karl Suessenguth once wrote, there are two kinds of discoveries: Detecting a thing nobody has seen before, or thinking what no one has thought before about something that everybody sees. A discovery of the second kind, and one of great moments in our science, was Sprengel’s theory of the flower. This theory clearly expressed for the first time the notion that flowers are designed for the transmission of pollen by foreign vectors, that is, animals or wind, and they can be understood only from this perspective.

An approach to the rapid development of complex mechatronic systems based on the comprehensive use of computer-simulation techniques is presented. Mechatronic systems with mechanical and non-mechanical components including discontinuous behaviour and varying structure are modelled as collections of dynamic transmission-elements using object-oriented programming techniques. The control system and user-interface, including the input-devices, are modelled in the same environment, allowing a realistic simulation of the complete controlled system at an early stage. Subsequently, the control system is ported to the final real-time processor without changes. This approach is demonstrated in an ongoing project to develop the control system of a balance-crane.

Crown ether 4 as a receptor core for protonated primary amines such as amino acids has been synthesized and incorporated into oligodeoxynucleotides as dangling ends. Crown ether 4 as a receptor core for protonated primary amines such as amino acids has been synthesized and incorporated into oligodeoxynucleotides as dangling ends.

A survey is given of the ecological constraints which affect the process of pollen transfer — and hence the gene flow — within a biocenosis. Wind pollination (anemophily) plays a dominant role in species-poor communities only. The quantity of zoophilous species increases equator-ward to up to 100 % and so does the degree of integration in animal-plant interactions. Biotic pollination is pinpointed. Manifoldness and specifity of methods reduce pollen waste and mispollinations. Saturated ecosystems dispose of a complete set of pollination syndromes and the respective pollinator guilds, narrow niche widths, a high percentage of eutropic flowers, shorter flowering times, and a temporal and spatial partitioning of floral resources. In pioneer communities generalists (allotropic flowers) or autogamy prevail. Flowering times are extended and there is less biotic integration. — Usually, floral contrivances favour allogamy. Genetic heterogeneity of potential sexual partners is effected by seed dispersal while gene flow results from pollen transfer. The mean range of the latter and thus the sizes of an individual’s interaction sphere within a population (neighbourhood) are species-specific and depend on, e.g., gregariousness; efficiency of the pollination apparatus; nectar quantity; kind of pollinator, its flying range, and flight direction as well as terrain features. Usually, it amounts to a few meters only. Anemophilic and generalist species suffer from a more intense pollen waste than do specialists, but compensate for it by high pollen/ovule ratios. Habitually sparse species are pollinated by trapliners or benefit synergistically from the presence of a similar dominating species. Synergism by vicariating flowering times secures the continuity of a common pool of polylectic pollinators. An oligolectic pollinator’s dependency of certain flowers is often more obligatory than vice versa. Establishment of species with specialized flowers requires additional prerequisites for the existence of respective oligolectic pollinators: nectar and pollen in due proportion, nesting facilities, foodplants or prey for the larvae, climatic conditions, etc. These dependencies and minimum population sizes are critical factors for the survival of a biocenosis.

This text approaches floral odour analysis using thin layer chromatography. It includes illustrations of flora morphology and anatomy.

Summary of part I and II Observations covering a period of several years have shown that Asarum caudatum is regularly pollinated by fungus gnats. Thereby attention was directed to certain appendages resembling mushrooms or parts thereof, occurring on perianths, axes, or bracts of ecologically related flowers. A hypothesis is being put forward that these appendages are dummies for deceptive attraction of fungivorous Diptera such as Mycetophilids, Sciarids, etc., to ensure cross pollination by these insects. In Asarum spp. as well as in the Aroids Arisarum proboscideum and Arisaema utile, this function has been substantiated by direct proof. By analogy, or from observations of related, non-mimetic species, the visit of fungus gnats is equally predicted for Aristolochia arborea, species of the Orchid genera Masdevallia (sect. Chimaeroideae), Cypripedium and Corybas, the section Trisecta of Arisaema, and Arachnitis uniflora, member of Corsiaceae, all of them mimicking fungus parts, too. The fungus mimetes - as fungus gnat flowers, in general, a hitherto undescribed subclass of the myiophilous style - are dwellers of the dark forest floor, with blossoms close to the bottom (geophily), of dark purple brown hues as a rule and white or translucent patterns, of seeming scentlessness or mushroom-like and musky odors, and intensive local transpiration of the fungus-like parts. They are urn-shaped or kettle-traps of a simple type. The fungus gnats whose relation to mushrooms is discussed regarding its parasitic ultilization by the deception flowers, approach the latter on account of their breeding instincts. Misled by their releasing system involving olfactory, light, tactile and humidity perception, the midges lay their eggs (or try to do so) into the lamella or pore imitations and thus they pollinate the flower. Eggs and larvae, incapable of eating the flower tissue, die before anthesis is finished. Mating males of the gnats also contribute to pollination. Counts of the eggs and larvae in Asarum caudatum flowers resulted in visit rates up to 76 % of the flowers in cultivation and up to 35 % in natural surroundings. Infected flowers contained 4 eggs on the average. Mostly not more than one egg is laid per oviposition. Fungus gnat visits in Asarum caudatum continue during the first five days, fade then, and finish completely, after anthesis - of 9—12 days total duration — has come to an end. Allogamy by the help of fungus gnats is presumed to be a general feature of Asarum (incl. Heterotropa), a genus in which fungus-like structures occur in 8 of its sections

As has been formerly shown, the double-spurred flowers of the South African genus Diascia (Scrophulariaceae) produce fatty oil as a primary attractant. Their oil-collecting pollinators have so far remained unknown. It is concluded from the morphology and from direct evidence of flower visitation that the recently established Melittid genus Rediviva represents the co-evolved pollinator group of these plants, at the same time demonstrating the presence of “manual” oil collectors in Southern Africa. The bees must introduce their especially equipped forelegs into the paired spurs of Diascia for harvesting the oil, thereby pollinating the flower. In the described case, a new species, Rediviva emdeorum, has extremely elongate front legs which perfectly fit the spurs of Diascia longicornis.

The reproductive structures ofDeplanchea tetraphylla (Bignoniaceae) exhibit a significant number of unusual features: inflorescence with an apical “platform”; flowers yellow, short-tubed, strongly zygomorphic; mouth closed through lateral compression; stamens and style long-exserted, erect or slightly reclined; nectar dark brown, exposed in the spoon-shaped lowermost corolla lobe and apparently acting also as a visual cue. These features suggest a highly elaborate syndrome for bird pollination: the birds (probably lorikeets) perch on the inflorescence platform and bend downwards to take up the exposed nectar, thus touching the exserted anthers and stigmas with the throat or breast. The likely evolution of this syndrome by additive steps, effecting a change from “head up” to “head down” position of the pollinator, can be traced from the floral structure of the remaining four species of the genus.

The highly specialized, two-celled hairs fringing the anthers ofCyclanthera pedata (L.)Schrad. and its relatives aid in pollination by producing a glue which sticks the coarse pollen grains onto insect visitors. This was proven by direct observations, confirming older assumptions. The adhesive is extruded from the big basal cell which bursts upon the slightest touch to the small top cell.—Turgor and, possibly, swelling pressure of the sticky material, are responsible for plasmoptysis and ejaculation. Cell contraction is due to tension of cuticular clips and, to a minor degree, to elasticity of the pectinic wall. A preformed apical dehiscence line disrupts when the top cell is bent aside.—The anthers hairs of a flower develop synchronously. From light and electron microscopic observations, the adhesive appears not to be a product of internal secretion. It originates from the endopolyploid giant nucleus of the basal cell, which finally degenerates by liquefying and swelling. The numerous peculiar elaioplasts apparently do not contribute to the hair's function.—The anther hairs are homologous to, and possibly have evolved from the so-called explosion hairs occurring on the green parts of manyCucurbitaceae.

The many-flowered, brush-like spikes ofEncholirium glaziovii, a ground-dwelling pitcairnioid bromeliad of the “campo rupestre” formation of southeastern Brazil, was observed being pollinated by the glossophagine bat,Lonchophylla bokermanni, in the Serra do Cipo (Minas Gerais). Nectar feeding was while hovering, and the pollen was preferentially transferred by the bat's snout. The floral pattern is chiropterophilous; unlike known tillandsioid bat flowers, stamens and style are protrusive beyond a small, persistent perigon, and anthesis, apparently protogynous, extends over several nights, with gradual onset and cease. Although various other flower-visitingChiroptera are known to occur in the area and are not mechanically precluded from exploitingEncholirium glaziovii, no one seems to compete withLonchophylla bokermanni. This species, a trap-liner, habitually forages in open habitats, a possible reason for its exclusiveness.—Flower details of two other species ofEncholirium from the same locality including one with the bat pollination syndrome, are given.

This study was carried out in Bhodkhore Community Forest Users Group in Parbat district, Nepal with the overall objective to develop a clearer understanding of the challenges for service providers while working towards improving the Community Forestry governance. The primary data were collected through personal interviews, group discussions, key informant interviews and direct observations using a series of questionnaires and check lists. Similarly, the secondary data were gathered from reports and records from Community Forestry User Group and service providers, and from relevant scientific literature. The data were analyzed using qualitative and quantitative tools. The results show that the existing challenges for service providers mainly include financial resource management, time management and inadequate technical support for forest management. Key words: Community Forestry, Governance, Service Providers, Challenges doi: 10.3126/banko.v18i2.2169 Banko Janakari, Vol. 18, No. 2, 18-24

Es werden einige Orchideenbluten mit Spornbildungen besprochen, die durch Synorganisation (Koaptation) heterogener Perigonteile entstehen. 1. Bei einigenRodriguezia-Arten bildet sich das nektarfuhrende Spornorgan aus den verwachsenen und mit ihren freien Langsrandern scheidenformig zusammenneigenden seitlichen Sepalen, die einen sezernierenden hypopeltaten Labellumfortsatz umschliesen. 2. BeiBatemania, Cochleanthes undChondrorhyncha formt sich jedes der seitlichen Sepalen getrennt durch Langsfaltung zu je einem Scheinsporn. Das Spornpaar, durch Eigensekretion nektarfuhrend oder mit Safthaaren ausgekleidet, korrespondiert mit dem Bluteninnern. 3. Der Nektarapparat vonComparettia undNeokoehleria entsteht durch Koaptation eines aus dem Sepalenpaar gebildeten echten Sporns und nectarogenen Anhangen des Labellums. 4. Der Sporn vonCryptocentrum ist als kongenitale, einseitige Verwachsung eines Lippensporns mit der Innenwand eines aus den seitlichen Sepalen zusammengesetzten Sporns aufzufassen.

Die geologischen Einsichten der letzten Jahrzehnte haben unsere Vorstellungen von der Palaogeographie der Erde umwalzend verandert. Die Biologen beginnen erst, die Folgerungen daraus zu ziehen und die Entstehungsgeschichte der heutigen Floren- und Faunenreiche neu zu uberdenken. Letztlich bleibt kaum eine biologische Disziplin davon unberuhrt. Auch die Blutenokologie, ein Wissensgebiet, das auf den ersten Blick von dieser Neuorientierung wenig tangiert erscheint, vermag ihr neue Aspekte abzugewinnen und ihrerseits einen nicht unwichtigen Beitrag zur Rekonstruktion der biogeographischen Veranderungen zu leisten. Denn diese haben ihre Spuren unzweifelhaft auch in der Physiognomie der Bluten hinterlassen.

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Summary The flowers of Basistemon spinosus, a Neotropic shrubby member of the tribe Hemimerideae, were found to secrete fatty oil as an attractant. The pollinators, oil-collecting bees of the exomalopsine genus Paratetrapedia, were observed in the Chaco forest of northern Argentina. In contrast to related genera, the carpet of Oil-producing glandular hairs (elaiophore) is single, and the cavity that bears it, is only slightly bisaccate. Flower features suggest less close affinity to Angelonia than has previously been assumed, but rather tending towards Old World relatives.

Udgivelsesdato: 2003 Synthesis of an asymmetrically substituted triaza crown ether, its incorporation into the 3′-end and 5′-end of nine-mer oligonucleotides, and the influence of various alkanediamine ligands on duplex thermostabilities are reported.