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The transcription factor ATF2 was previously shown to be an ATM substrate. Upon phosphorylation by ATM, ATF2 exhibits a transcription-independent function in the DNA damage response through localization to DNA repair foci and control of cell cycle arrest. To assess the physiological significance of this phosphorylation, we generated ATF2 mutant mice in which the ATM phosphoacceptor sites (S472/S480) were mutated (ATF2KI). ATF2KImice are more sensitive to ionizing radiation (IR) than wild-type (ATF2 WT) mice: following IR, ATF2KImice exhibited higher levels of apoptosis in the intestinal crypt cells and impaired hepatic steatosis. Molecular analysis identified impaired activation of the cell cycle regulatory protein p21Cip/Waf1in cells and tissues of IR-treated ATF2KImice, which was p53 independent. Analysis of tumor development in p53KOcrossed with ATF2KImice indicated a marked decrease in amount of time required for tumor development. Further, when subjected to two-stage skin carcinogenesis process, ATF2KImice developed skin tumors faster and with higher incidence, which also progressed to the more malignant carcinomas, compared with the control mice. Using 3 mouse models, we establish the importance of ATF2 phosphorylation by ATM in the acute cellular response to DNA damage and maintenance of genomic stability.

Optimizing the catalyst layer of polymer electrolyte membrane fuel cells and water electrolyzers requires a good understanding of its properties. The in-plane electrical resistance of the catalyst layer is a key property, which impacts the overall cell performance. In this work, we present a simple method to measure the in-plane electrical resistance of catalyst layers under various conditions based on the transfer length method. The applicability of the method was demonstrated on four examples: 1) Placing the compact setup in a climate chamber, showed that reducing the relative humidity from 95% to 40% yields a reduction of the resistivity of 15% in a fuel cell cathode catalyst layer; 2) graphitizing CNovel™ carbon support reduces the resistivity by 98% in a fuel cell cathode catalyst layer; 3) adding an electrically conductive polymer as electrode binder lowers the in-plane resistivity of a water electrolyzer anode by 50%; 4) adding IrO2-nanofibers to a low-loaded IrO2-nanoparticle anode lowers its resistivity by 60%. The broad range of applications in this work confirms the versatility of the setup enabling widespread application. The method hence contributes to an improved deconvolution of different loss mechanisms including electrical in-plane resistivity.

AFLP profiles, nuclear ITS sequences, and chloroplast psbA-trnH intergenic spacer sequences for representative samples of the New Zealand edelweiss species Leucogenes grandiceps, L. leontopodium, L. neglecta, and L. tarahaoa were examined. Analysis of AFLP profiles from a small number of populations strongly groups samples of each species, and in turn samples of diploid (2n = 2x = 28) L. leontopodium and tetraploid (2n = 4x = 56) L. neglecta cluster together, consistent with a derivation of the latter from the former by auto-polyploidy. However, octoploid (2n = 8x = 112) L. tarahaoa does not cluster closely with either L. neglecta or L. leontopodium, indicating this species has an independent origin. Analyses of chloroplast DNA sequences show that although the majority of Leucogenes samples share similar chloroplast sequences not sampled from other species of New Zealand Gnaphalieae, a single accession of L. grandiceps and North island populations of L. leontopodium share chloroplast sequences more similar to other species of New Zealand Gnaphalieae. ITS sequence variation is more complex, with sequences sampled from Leucogenes not constituting a monophyletic group, and striking intraspecific variation detected within L. grandiceps.

Craspedia(Asteraceae: Gnaphalieae) is a genus of 23 species found only in Australia and New Zealand. Maximum parsimony and maximum likelihood analyses of ITS and ETS intergenic spacers from the nuclear genome recovered three main lineages. The first lineage consists solely of the Australian species C. haplorrhiza, the relationships of which are unresolved, and the second includes species that are also exclusively Australian in distribution. The third lineage comprises two monophyletic groups; one including all the remaining Australian species sampled and the other, all New Zealand entities sampled. Monophyly of New Zealand Craspediais also supported by analysis of psbA-trnHintergenic spacer sequences. Australian alpine species are independently derived from within the two larger Australian lineages. Both major Australian lineages are present in Tasmania suggesting multiple colonisations from mainland Australia. The single lineage of New Zealand Craspediaand the low divergences between Australian and New Zealand Craspediasamples are consistent with the derivation of New Zealand Craspediavia a single dispersal event from south-east Australia in the Late Tertiary or Quaternary. Compared with Australian Craspedia, the New Zealand species show extensive morphological divergence but little sequence divergence, suggesting a recent and rapid species radiation.

Helichrysum lanceolatum is a widespread and variable New Zealand species that has been regarded as a species complex. A survey of genetic variation in Helichrysum lanceolatum using AFLP, nrDNA ITS sequence, and cpDNA psbA-trnH sequences is presented. No evidence to support segregate taxa at any rank was found. Geographic structure in genetic diversity is weak and consistent with a model of increasing genetic isolation with distance.

Relationships of the small austral genus Abrotanella are uncertain. It was previously included in the Anthemideae or more recently in the Senecioneae. We conducted a phylogenetic analysis of 39 accessions that included most species of Abrotanella and putative relatives including Blennosperma, Crocidium and Ischnea. These four genera have been considered to form subtribe Blennospermatinae. Our results suggest that the Blennospermatinae are polyphyletic; Blennosperma, Crocidium and Ischnea form a well-supported clade nested within the Senecioneae, while Abrotanella forms another well-supported clade that is distinct from these genera and its sister is not resolved. Molecular dating of Abrotanella suggests that the lineage initially diverged during the early Miocene. Secondary species radiations in Australasia and in southern South America that occurred 3 million years ago undoubtedly reflect long-distance dispersal, colonization and speciation. Both the ITS region and the 5' trnK/matK chloroplast DNA intron gave similar divergence estimates. The estimates were also robust to changes in the tree topology and to the different methods used to calculate divergence times.

Haastia, an alpine genus of three species endemic to New Zealand, has been of uncertain tribal affiliation within the Asteraceae subfamily Asteroideae. On the basis of morphological evidence it has been variously assigned to Gnaphalieae and Astereae, split between tribes, and unassigned to a tribe. Here morphological characters that have been used to delimit tribes of Asteroideae are reviewed. These characters are described for Haastia and evidence for its tribal position is assessed. The weight of the evidence favours inclusion in Senecioneae and suggests affiliation to Brachyglottis. This is in accordance with recent phylogenetic analyses of ITS and 5' trnK/matK intron sequences that place Haastia in a Senecioneae clade with Brachyglottis and allied genera.

Euchiton mackayi and E. nitidulus lack the definitive characters of Euchiton, namely stolons and paired papillae on the cypsela epidermis. A morphological comparison of species of Euchiton from New Zealand and Australia, supplemented by published data on other species and genera, demonstrates that E. fordianus, E. mackayi, E. nitidulus, and E. poliochlorus are morphologically distinct from the remainder of Euchiton and from all other genera of Gnaphalieae. This is supported by published evidence from ITS sequences. Euchiton fordianus, E. mackayi, E. nitidulus, and E. poliochlorus are transferred to a new genus, Argyrotegium, and new combinations are made.

Objective: A variety of medical robots have been developed in recent years. MRI, including MR angiography and morphological imaging, with its excellent soft-tissue contrast is attractive for the development of interventional MRI-guided therapies and operations. This paper presents a telerobotic device for use in CT- and/or MR-guided radiological interventions. A robotic device for precise needle insertion during MR-guided therapy of spinal diseases will be briefly described.Materials and Methods: Actuation of robots in an MRI environment is difficult due to the presence of strong magnetic fields. Therefore, the robot was constructed of nonmagnetic materials. The system frame was built from polyether ether ketone (PEEK) and fiber-reinforced epoxy, and actuated using ultrasonic and pneumatic motors. Completely MR-compatible sensors were developed for positioning control.Results: Accuracy evaluation procedures and phantom tests were performed, with the required accuracy of approximately 1 mm being achieved and no significant artifacts being caused by the robotic device during MR image acquisition.

Activation of the calcium sensing receptor (CaR) by small increments in extracellular calcium (Ca2+e) induces intracellular calcium (Ca2+i) oscillations that are dependent on thapsigargin-sensitive intracellular calcium stores. Phenylalkylamines such as NPS R-568 are allosteric modulators (calcimimetics) that activate CaR by increasing the apparent affinity of the receptor for calcium. We determined, by fluorescence imaging with fura-2, whether the calcimimetic NPS R-568 could activate Ca2+ioscillations in HEK-293 cells expressing human CaR. NPS R-568 was more potent than Ca2+eat eliciting Ca2+ioscillations, particularly at low [Ca2+]e(as low as 0.1 mm). The oscillation frequencies elicited by NPS R-568 varied over a 2-fold range from peak to peak intervals of 60–70 to 30–45 s, depending upon the concentrations of both Ca2+eand NPS R-568. Finally, NPS R-568 induced sustained (>15 min after drug removal) Ca2+ioscillations, suggesting slow release of the drug from its binding site. We exploited the potency of NPS R-568 for eliciting Ca2+ioscillations for structural studies. Truncation of the CaR carboxyl terminus from 1077 to 886 amino acids had no effect on the ability of Ca2+or NPS R-568 to induce Ca2+ioscillations, but further truncation (to 868 amino acids) eliminated both highly cooperative Ca2+-dependent activation and regular Ca2+ioscillations. Alanine scanning within the amino acid sequence from Arg873to His879reveals a linkage between the cooperativity for Ca2+-dependent activation and establishment and maintenance of intracellular Ca2+oscillations. The amino acid residues critical to both functions of CaR may contribute to interactions with either G proteins or between CaR monomers within the functional dimer.

The mature crystalline bacterial cell surface (S-layer) protein SbsC of Bacillus stearothermophilus ATCC 12980 comprises amino acids 31–1099 and assembles into an oblique lattice type. As the deletion of up to 179 C-terminal amino acids did not interfere with the self-assembly properties of SbsC, the sequence encoding the major birch pollen allergen (Bet v1) was fused to the sequence encoding the truncated form rSbsC31–920. The S-layer fusion protein, termed rSbsC/Bet v1, maintained the ability to self-assemble into flat sheets and open-ended cylinders. The presence and the functionality of the fused Bet v1 sequence was proved by blot experiments using BIP1, a monoclonal antibody against Bet v1 and Bet v1-specific IgE-containing serum samples from birch pollen allergic patients. The location and accessibility of the allergen moiety on the outer surface of the S-layer lattice were demonstrated by immunogold labeling of the rSbsC/Bet v1 monolayer, which was obtained by oriented recrystallization of the S-layer fusion protein on native cell wall sacculi. Thereby, the specific interactions between the N-terminal part of SbsC and a distinct type of secondary cell wall polymer were exploited. This is the first S-layer fusion protein described that had retained the specific properties of the S-layer protein moiety in addition to those of the fused functional peptide sequence.

Calcium sensing (CaR) and Group I metabotropic glutamate receptors exhibit overlapping expression patterns in brain, and share common signal transduction pathways. To determine whether CaR and Group I metabotropic glutamate receptors (mGluRs) (mGluR1α and mGluR5) can form heterodimers, we immunoprecipitated CaR from bovine brain and observed co-precipitation of mGluR1α. CaR and mGluR1α co-localize in hippocampal and cerebellar neurons, but are expressed separately in other brain regions. In vitrotransfection studies in HEK-293 cells established the specificity and disulfide-linked nature of the CaR:mGluR1α (CaR:mGluR5) interactions. CaR:mGluR1α (CaR:mGluR5) heterodimers exhibit altered trafficking via Homer 1c when compared with CaR:CaR homodimers. CaR becomes sensitive to glutamate-mediated internalization when present in CaR:mGluR1α heterodimers. These results demonstrate cross-family covalent heterodimerization of CaR with Group I mGluRs, and increase the potential role(s) for CaR in modulating neuronal function.

Species Plantarum: Flora of the World. Australian Biological Resources Study. ISSN1441-1393 (series). Address for registering Standing Orders: ABRS (Publications), GPO Box 787, Canberra ACT 2601, Australia. (www.anbg.gov.au/abrs). Standing Order customers receive a 20% discount on the Rec ommended Retail Price of the booklets. Price for the first two parts of Species Plantarum (Introduction and Irvingiaceae): A$20.Species plantarum: Flora of the World. Introduction to the series by A. E. Orchard. Australian Biological Resources Study. 1999.91 p. ISBN 0-642-56804-9 (paperback).Species Plantarum: Flora of the World. Part 1, Irvingiaceae by D. J. Harris. Australian Biological Resources Study. 1999. 25 P. ISBN 0-642-56800-6 (paperback).Species Plantarum: Flora of the World. Part 2, Stangeriaceae by E. M. A. Steyn, G. F. Smith, and K. D. Hill. Australian Biological Resources Study. 1999. 9 p. ISBN 0-642-56805-7 (paperback).Species Plantarum: F1ora Of the Wor1d. Part 3, We1witschiaceae by E' M* A. Steyn and G. F. Smith. Australian Biological Resources Study. 1999. 8 p. ISBN 0-642-56806-5 (paperback).Flora of Australia Volume 48. Ferns, Gymnosperms and Allied Groups edited by p. M. McCarthy. CSIRO Publishing and Australian Bio logical Resources Study, Melbourne. 1998. xxii & 766 p. Hardback ISBN 0-643-059717, price A$94.95. Paperback ISBN 0-643-05972-5, price A$59.95.Methods in plant electron microscopy and cytochemistry edited by William V. Daskek. Humana press, Totowa, New Jersey. 20.312 p. Paperback. US$89.50. ISBN 0-896-03809-2.

Many automation tasks require human intervention and guidance. A control system architecture combining work units and master units by software interfaces is described. OSCAR2is incorporated as a universal transform service. It is regarding dynamic properties of work units. Implementing the transform at the master site eases integration of new robot types. The dynamic behaviour when crossing singular points is compared with a closed form standard transform. The control system has also been applied in medical manipulator systems.

Statistics for the composition of the New Zealand seed plant flora are presented. The information provided is based on the number of wild speties listed in the New Zealand Plant Names Database Landcare Research' New Zealand' The statistics include the number of wild species, genera, and families; the number of species in the largest genera and families; and species numbers according to biostatus categories.

SummaryThe research activities of the Forschungszentrum Karlsruhe on minimally-invasive surgery (MIS) have for several years improved techniques and instrumentation for different types of MIS. Many types of instruments and robotic devices have been developed and new techniques implemented. In this paper we present the most recent results from our different projects, such as endoscopic heart surgery, tracking systems, a camera guidance device, telemanipulator systems, minimally-invasive breast biopsy in closed-bore MRI, endoscopic training simulators and developments using smart materials (e.g. Nitinol).

Calcium-sensing receptors are present in membranes as dimers that can be reduced to monomers with sufhydryl reagents. All studies were carried out on the human calcium-sensing receptor tagged at the carboxyl terminus with green fluorescent protein (hCaR-GFP) to permit identification and localization of expressed proteins. Truncations containing either the extracellular agonist binding domain plus transmembrane helix 1 (ECD/TMH1-GFP) or the transmembrane domain plus the intracellular carboxyl terminus (TMD/carboxyl terminus-GFP) were used to identify the dimerization domain. ECD/TMH1-GFP was a dimer in the absence of reducing reagents, whereas TMD/carboxyl-terminal GFP was a monomer in the absence or presence of reducing agents, suggesting that dimerization occurs via the ECD. To identify the residue(s) involved in dimerization within the ECD, cysteine --> serine point mutations were made in residues that are conserved between hCaR and metabotropic glutamate receptors. Mutations at positions 60 and 131 were expressed at levels comparable to wild type in HEK 293 cells, had minimal effects on hCaR function, and did not eliminate dimerization, whereas mutations at positions 101 and 236 greatly decreased receptor expression and resulted in significant amounts of monomer in the absence of reducing agents. The double point mutant hCaR(C101S/C236S)-GFP was expressed more robustly than either C101S or C236S and covalent dimerization was eliminated. hCaR(C101S/C236S)-GFP had a decreased affinity for extracellular Ca2+ and slower response kinetics upon increases or decreases in agonist concentration. These results suggest that covalent, disulfide bond-mediated dimerization of the calcium-sensing receptor contributes to stabilization of the ECD and to acceleration of the transitions between inactive and active receptor conformations.

Nine species are reported as additional or newly substantiated fully naturalised records for the flora of New Zealand during the 2-year period 1997-1998. Notable additions are the invasive Eupatorium cannabinum and Acacia sophorae, which are well established in the Wanganui area, and Myricaria germanica which is relatively common along parts of the Waimakariri River, Canterbury. Thirty-seven species, including two ferns, are considered to be new records of casual naturalised plants. Thirty-eight additional species that were previously known from few collections are given extended distributions.

AbstractAnalyses of ITS sequences of Australasian Gnaphalieae reveal at least six distinct lineages of Gnaphalieae in New Zealand. Our results suggest that the New Zealand species of Craspediaform a monophyletic group, which originated in Australia. The stoloniferous species of Euchitonare clearly separated from the non‐stoloniferous species. They are not closely related to any other New Zealand gnaphalioid taxon. The Australian species of Ewartiaare a polyphyletic group and are not closely related to the sole New Zealand species, Ewartia sinclairii. An almost endemic New Zealand Glade consists of species currently included in Anaphalioides, Ewartia, Helichrysum, Leucogenes, Rachelia, and Raoulia. It appears that the New Zealand Glade diversified rapidly soon after the arrival of its ancestor in New Zealand. The relationships of Ozothamnus leptophyllusare poorly resolved. Pseudognaphalium luteoalbumemerges with mainly Asian and South American Gnaphalieae.

The effects of independently varying intracellular and extracellular pH on sodium pump fluxes were studied in the squid giant axon. By means of intracellular dialysis, we found that changes of intracellular pH (pHi), but not of extracellular pH, affected ouabain-sensitive Na+ efflux and K+ influx over the pH range of 6.0-8.6. Both fluxes were maximum at a pHi of 7.2-7.4. Variations away from this optimal pHi in either the acidic or alkaline direction resulted in a graded inhibition of both ouabain-sensitive fluxes. The kinetic basis for the inhibitory effect of acidic pHi was examined by comparing the kinetic parameters of activation of ouabain-sensitive sodium efflux by intracellular Na+ (Na+i) and extracellular K+ (K+o) at normal pHi with those at acidic pHi. We found that the inhibitory effect of intracellular acidity results from a reversible decrease in maximum velocity (Vmax), without an effect on the activation parameters for Na+i (K1/2 Na+i) or K+o (K1/2 K+o).

The effects of vanadate and fluoride on the Na+-K+-Cl- cotransporter of the squid giant axon were assessed. In axons not treated with these agents, intracellular dialysis with ATP-depleting fluids caused bumetanide-inhibitable 36Cl influx to fall with a half time of approximately 16 min. In the presence of either 40 microM vanadate or 5 mM fluoride, the decay of bumetanide-inhibitable 36Cl influx was significantly slowed; half time for vanadate-treated axons is 45 min and for fluoride-treated axons is 37 min. These agents are not exerting their effects on Na+-K+-Cl- cotransport by influencing the rate of ATP depletion of the axon, since they had no effect on the ATP hydrolysis rate of an optic ganglia homogenate. We therefore suggest that these data support the hypothesis that Na+-K+-Cl- cotransport in squid axons is regulated by a phosphorylation-dephosphorylation mechanism and that vanadate and fluoride reduce the rate of dephosphorylation by inhibiting a protein phosphatase.

AbstractThe genus Racheliaand its single species, R. gloria, are described and illustrated. Rachelia glariais a rhizomatous perennial occurring on fine argillite scree on the dry mountains of Marlborough and the extreme north of Canterbury in the South Island of New Zealand. Its taxonomic affinities lie with the gnaphalioid Compositae. R. glariais evidently very local and is classed as vulnerable, but it is not considered to be endangered.

Solvolysis of N-methyl-3-thioethoxy-4-azahomoadamantane (4c) in ethanolic sodium ethoxide followed first order kinetics. Reaction presumably proceeds via an SN1 mechanism with resonance stabilization of the bridgehead carbonium ion by the electrons on adjacent nitrogen. Addition of ethoxide to the bridgehead carbonium ion yields N-methyl-3-ethoxy-4-azahomoadamantane (4c). Solvolysis of N-protio compound (4b) under similar conditions was much more rapid, and followed first order kinetics for both substrate and base. The mechanism apparently involves an elimination-addition pathway in which ethoxide promoted elimination of ethyl mercaptan is followed by net addition of ethanol across the bridgehead imine to form ether 4d.

The relaxation dynamics of hot excitons was studied in (Zn,Cd)Se/ZnSe quantum wells and quantum dots. A fast population of the radiative excitonic ground state occurs for an excitation excess energy corresponding to an integer number of optical phonon energies. This is indicated by a spectrally narrow photoluminescence peak observed immediately after the exciting laser pulse. Spatial diffusion of excitons, controlled by the interaction between excitons and acoustic phonons, causes a distinct linewidth broadening with increasing delay time in quantum wells. In contrast, this process is found to be strongly suppressed in quantum dots.

Acetylcholine (ACh) binding to atrial muscarinic receptors activates an inwardly rectifying K+ current (IK[ACh]) via a pertussis toxin-sensitive GTP-binding protein (GK). The muscarinic K+ channel (termed GIRK1) has been cloned, and the nucleotide sequence contains nine consensus sites for protein kinase C (PKC) phosphorylation (16). Dephosphorylation of the muscarinic K+ channel has been implicated in rapid IK[ACh] desensitization in the presence of agonist (13). Staurosporine is a widely used membrane-permeant inhibitor of PKC and other protein kinases (7), including G protein-coupled receptor kinases. We investigated the role of phosphorylation in the regulation of IK[ACh] by examining the effect of a variety of protein kinase inhibitors. Staurosporine produced a rapid and reversible dose-dependent decrease in IK[ACh], activated by either GTP or guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S). Other PKC inhibitors, including calphostin C and K-252b, were without effect on GTP gamma S-activated IK[ACh]. In excised patches of atrial membrane under nonphosphorylating conditions (0 ATP, 1 mM 5'-adenylylimidodiphosphate), staurosporine reversibly reduced muscarinic K+ channel activity without altering single-channel current amplitude. These results suggest that staurosporine inhibits IK[ACh] by a mechanism independent of intracellular protein kinases.

The Na(+)-K(+)-Cl- cotransporter of the squid giant axon requires ATP and is inhibited by intracellular Cl- (Cli-) in a concentration-dependent manner ([Cl-]i > or = 200 mM completely inhibits the cotransporter). In the present study we address the question of whether inhibition of cotransport by Cli- is due to a Cl(i-)-induced increase of protein phosphatase activity. Intracellular dialysis was used to apply the phosphatase inhibitor okadaic acid (OKA) under conditions of [Cl-]i at 0, 150, or 300 mM during measurement of cotransporter-mediated unidirectional Cl- influx into axons. At 0 mM [Cl-]i, the application of 250 nM OKA had no effect on the cotransport-mediated Cl- influx when axons were dialyzed with the normal intracellular ATP concentration ([ATP]i = 4 mM). Reduction of [ATP] to 50 microM resulted in a significant decrease of the bumetanide-sensitive CL- influx, which could be partially reversed by OKA treatment. Similarly, in ATP-limited axons with [Cl-]i at 150 mM, cotransporter influx was partially stimulated by treatment with OKA. However, axons dialyzed with 300 mM [Cl-]i ([ATP]i = 50 microM) had no measurable cotransport influx, nor was subsequent treatment with OKA able to induce a cotransport-mediated Cl- influx. We conclude that the inhibition of cotransport caused by Cli- is not the result of an increase in the OKA-sensitive protein phosphatase activity.

In the present study, the applicability of crystalline bacterial cell-surface layers (Slayers) as novel immobilization matrices and reaction zones for dipstick-style immunoassays was investigated. For this purpose, S-layer-carrying cell-wall fragments from Bacillus sphaericus CCM 2120 were deposited on a microporous support, and the Slayer protein was cross-linked with glutaraldehyde. For developing appropriate test systems, either human IgG was directly linked to the carboxylic acid groups from the S-layer protein or it was immobilized using Protein A or, after biotinylation, using streptavidin. A clear correlation was obtained between the amount of anti-human IgG applied and the absorbance values in the immunoassays. S-layers with covalently bound recombinant major birch pollen allergen were used for quantitative and semiquantitative determination of an antibody raised against it. Using S-layers as an immobilization matrix in comparison to amorphous polymers has advantages in that the closed monolayers of functional macromolecules on their outermost surface allows for strong signals in immunoassays, almost completely eliminates background and prevents diffusion.

Six taxa are reported as additional or newly substantiated naturalised records for the weed flora of New Zealand during the 3-year period 1994-1996. Thirty-six species are considered to be new records of casual adventive plants. Eleven additional species that were previously poorly known are given extended distributions. Most records are in the Fabaceae (6).

An evaluation is presented of the exceptionally large number of name changesJunparticularly of generic attribution, proposed for New Zealand gnaphalioid taxa, principally in the past decade. The transfer of certain New Zealand species to AnaphalioidesNovEuchiton, and Pseudognaphalium is supported, but some other changes, including the establishment of Ewartiothamnus, the resurrection of Psychrophyton, and the relocation of New Zealand species of Helichrysum, require (and are now receiving) further study.

AbstractThe sole New Zealand species attributed to Cassinia, C. leptophylla, is shown to have its closest relatives within Ozothamnusrather than Cassinia. Cassinia leptophyllais therefore transferred to Ozothamnus.

Pollen ultrastructure has been investigated in 35 taxa of Gnaphalieae (Compositae), predominantly from New Zealand. Pollen grains of all taxa examined are tectate-columellate and caveate. The characters regarded as particularly distinctive include variability of columellar form and internal organisation of the columellae. The importance of pollen characters in the classification of the New Zealand Gnaphalieae is discussed. The species of Haastia, characterised by senecioid pollen and internal tecta, do not belong to the Gnaphalieae. In the species with helianthoid pollen and sub-columellae five different columellae types can be distinguished.

The external pollen morphology has been investigated in 45 taxa of Gnaphalieae (Compositae), predominantly from New Zealand, by means of light microscopy and SEM. Pollen grains of all taxa examined are more or less spheroidal and echinate. Features regarded as particularly distinctive include size, spine density, spine length, spine shape and nature of perforations. It is shown that the pollen grains provide characters which are taxonomically useful in classification of New Zealand Gnaphalieae. Based on pollen morphology, Haastia does not belong to the tribe Gnaphalieae, and Gnaphalium (including the Tasmanian Ewartia planchonii) is distinct from the other New Zealand genera.

The paper presents a philosophy, an architecture and an implementation of a distributed manipulator control system whereby the controllers are to be interconnected by standard LAN-means. MONSUN focusses on manual control in the sense of telepresence systems but also includes semiautonomous operation modes. The application protocols are of prime importance for MONSUN to be an open system. An important finding is that a motorized master arm is of significant help giving natural cues for the limits of the actual working envelope.

The wealth of information existing on the general principle of S‐layers has revealed a broad application potential. The most relevant features exploited in applied S‐layer research are: (i) pores passing through S‐layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well‐defined positions and orientations and accessible for binding functional molecules in very precise fashion; (iii) isolated S‐layer subunits from many organisms are capable of recrystallizing as closed monolayers onto solid supports at the air‐water interface, on lipid monolayers or onto the surface of liposomes. Particularly their repetitive physicochemical properties down to the subnanometer scale make S‐layers unique structures for functionalization of surfaces and interfaces down to the ultimate resolution limit. The following review focuses on selected applications in biotechnology, diagnostics, vaccine development, biomimetic membranes, supramolecular engineering and nanotechnology. Despite progress in the characterization of S‐layers and the exploitation of S‐layers for the applications described in this chapter, it is clear that the field lags behind others (e.g. enzyme engineering) in applying recent advances in protein engineering. Genetic modification and targeted chemical modification would allow several possibilities including the manipulation of pore permeation properties, the introduction of switches to open and close the pores, and the covalent attachment to surfaces or other macromolecules through defined sites on the S‐layer protein. The application of protein engineering to S‐layers will require the development of straightforward expression systems, the development of simple assays for assembly and function that are suitable for the rapid screening of numerous mutants and the acquisition of structural information at atomic resolution. Attention should be given to these areas in the coming years.

At the posterior pole of the Drosophila oocyte, oskar induces a tightly localized assembly of pole plasm. This spatial restriction of oskar activity has been thought to be achieved by the localization of oskar mRNA, since mislocalization of the RNA to the anterior induces anterior pole plasm. However, ectopic pole plasm does not form in mutant ovaries where oskar mRNA is not localized, suggesting that the unlocalized mRNA is inactive. As a first step towards understanding how oskar activity is restricted to the posterior pole, we analyzed oskar translation in wild type and mutants. We show that the targeting of oskar activity to the posterior pole involves two steps of spatial restriction, cytoskeleton-dependent localization of the mRNA and localization-dependent translation. Furthermore, our experiments demonstrate that two isoforms of Oskar protein are produced by alternative start codon usage. The short isoform, which is translated from the second in-frame AUG of the mRNA, has full oskar activity. Finally, we show that when oskar RNA is localized, accumulation of Oskar protein requires the functions of vasa and tudor, as well as oskar itself, suggesting a positive feedback mechanism in the induction of pole plasm by oskar.

We investigated in detail the previously described capacity of pseudohyphae of Candida albicans to bind C3-coated particles. We show that the expression of the C3bi receptor of C. albicans was dependent upon the growth temperature of the fungi. C. albicans grown at 30 degrees C bound strongly to EAC1423bi, whereas those cells grown at 38.5 degrees C were completely devoid of this capacity. The molecule responsible for the attachment of EAC1423bi was heat labile and trypsin sensitive. Several, but not all, monoclonal antibodies to the alpha-chain of human complement receptor type 3 (CR3) stained C. albicans, and this reactivity was expressed in parallel with the capacity of C. albicans to bind EAC1423bi, i.e., both were dependent on the growth temperature of the fungi and were trypsin sensitive. In contrast to CR3, the binding of EAC1423bi to C. albicans did not require the presence of divalent cations. Rabbit immunoglobulin G antibodies directed against C. albicans inhibited the binding of EAC1423bi to C. albicans but not to human CR3. These inhibiting IgG antibodies recognized antigens expressed on the surface of pseudohyphae but not those of yeast cells. OKM-1, a monoclonal antibody to human CR3 inhibited the attachment of EAC1423bi to CR3 and also to C. albicans. OKM-1 precipitated a 130-kilodalton band from solubilized 125I-labeled C. albicans. We conclude that the complement receptors on C. albicans and human CR3 were antigenically related but not identical and that they differed in their functional characteristics.

Leaf anatomy is compared for 47 taxa of the tribe Inulcae (Compositae) from New Zealand and Tasmania. The taxa are tabulated according to their lamina structure. Noteworthy anatomical features are lamina type and grade of differentiation, stomatal position, epidermis and cuticle thickness, shape of palisade cells, number of bundle-sheath layers; presence or absence of sclerenchyma caps, water storage cells, secretory canals, abaxial collenchyma and protruding midrib. It is shown that leaf anatomy data provide characters which are taxonomically useful in classification of Inuleae.

AbstractForty-five species of Inuleae (Compositae), predominantly from New Zealand and Tasmania, were subjected to numerical phenetic analysis using 49 leaf anatomy and 38 leaf flavonoid characters. Results indicate that on the basis of overall similarity in this suite of characters: (1) Leucogenesis a good genus; (2) an undescribed taxon of Inuleae is a distinct monotypic genus; (3) New Zealand species currently placed in Anaphalis, Cassinia, and Ewartiaare generically distinct but are referred to the wrong genera; (4) similarity between species of Ewartiaand Gnaphaliumindicates that the boundary between these genera needs to be reassessed; (5) both Helichrysumand Raouliaare heterogeneous and need revision; (6) in New Zealand, Pseudognaphaliumis distinct from other gnaphalioid genera.

Intact cells of Bacillus stearothermophilus PV72 revealed, after conventional thin-sectioning procedures, the typical cell wall profile of S-layer-carrying gram-positive eubacteria consisting of a ca. 10-nm-thick peptidoglycan-containing layer and a ca. 10-nm-thick S layer. Cell wall preparations obtained by breaking the cells and removing the cytoplasmic membrane by treatment with Triton X-100 revealed a triple-layer structure, with an additional S layer on the inner surface of the peptidoglycan. This profile is characteristic for cell wall preparations of many S-layer-carrying gram-positive eubacteria. Among several variants of strain PV72 obtained upon single colony isolation, we investigated the variant PV72 86-I, which does not exhibit an inner S layer on isolated cell walls but instead possesses a profile identical to that observed for intact cells. In the course of a controlled mild autolysis of isolated cell walls, S-layer subunits were released from the peptidoglycan of the variant and assembled into an additional S layer on the inner surface of the walls, leading to a three-layer cell wall profile as observed for cell wall preparations of the parent strain. In comparison to conventionally processed bacteria, freeze-substituted cells of strain PV72 and the variant strain revealed in thin sections a ca. 18-nm-wide electron-dense peptidoglycan-containing layer closely associated with the S layer. The demonstration of a pool of S-layer subunits in such a thin peptidoglycan layer in an amount at least sufficient for generating one coherent lattice on the cell surface indicated that the subunits must have occupied much of the free space in the wall fabric of both the parent strain and the variant. It can even be speculated that the rate of synthesis and translation of the S-layer protein is influenced by the packing density of the S-layer subunits in the periplasm of the cell wall delineated by the outer S layer and the cytoplasmic membrane. Our data indicate that the matrix of the rigid wall layer inhibits the assembly of the S-layer subunits which are in transit to the outside.

Calcium sensing receptors are part of a growing G protein-coupled receptor family, which includes metabotropic glutamate, γ-aminoisobutyric acid, and pheromone receptors. The distinctive structural features of this family include large extracellular domains that bind agonist and large intracellular, carboxyl-terminal domains of as yet undefined function(s). We have explored the contribution(s) of the carboxyl terminus of the human calcium sensing receptor (CaR) by assessing extracellular Ca2+-mediated changes in intracellular Ca2+in individual HEK-293 cells transfected with CaR clones. In-frame fusion of EGFP to the carboxyl terminus of CaR had no effect on either the dose response for extracellular Ca2+activation or CaR desensitization. Carboxyl-terminal truncations, fused in-frame with EGFP (CaRΔ1024-EGFP, CaRΔ908-EGFP, CaRΔ886-EGFP, and CaRΔ868-EGFP), were assessed for alterations in Ca2+-dependent activation or desensitization. Significant effects on the dose-response relation for extracellular Ca2+were observed only for the CaRΔ868 truncation, which exhibited a decreased affinity for extracellular Ca2+anda decrease in the apparent cooperativity for Ca2+-dependent activation. The alterations in extracellular Ca2+affinity and cooperativity observed with CaRΔ868 were recapitulated by a point mutation, T876D, in the full-length CaR-EGFP background. All truncations with wild type dose-response relations exhibited desensitization time courses that were comparable to the full-length CaR, whereas the CaRΔ868 receptor desensitized completely after two exposures to 10 mmCa2+. Interestingly, the CaR point mutation T876D exhibited desensitization comparable to wild type CaR, suggesting that this mutation specifically modifies CaR cooperativity. In conclusion, these studies suggest that amino acid residues between 868 and 886 are critical to the apparent cooperativity of Ca2+-mediated activation of G proteins and to CaR desensitization.

Leaf anatomy is compared for all species ofRaoulia.The species are tabulated according to their lamina structure. Noteworthy anatomical features are lamina type and grade of differentiation, stomatal position, epidermal and cuticle thickness, shape of mesophyll cells, presence or absence of central clear cells, sclerenchyma caps, abaxial collenchyma and protruding midrib. It is shown that leaf anatomy data provide characters which are taxonomically useful inRaoulia.The main subgenera are supported except that the leaf anatomy ofR. haastiiis anomalous and that ofR. youngiiis typical ofR.subg.Raouliarather thanR.subg.Psychrophyton.The leaf anatomy ofR. petriensisis unique in the genus.