bluuebunny/crossref_metadata_2025 huggingface dataset:
Study explores space weather risk to natural gas pipeline in Finland
Authors: Pirjola Risto , Pulkkinen Antti , Viljanen Ari , Nevanlinna Heikki , Pajunpää Kari
Published: October 2006

Data being collected on the Finnish natural gas pipeline are providing a basis for estimating the space weather risk for the pipeline and for designing possible countermeasures. Finland's high latitude location makes such systems prone to problems caused by geomagnetically induced currents (GICs),but so far no harm has been detected.

The statistical GIC risk in the Finnish high‐voltage power system has already been estimated [Viljanen and Pirjola, 1989semi;Makinen, 1993],and the recent 8‐month project in 1998 to 1999, involving the Gasum Oy Company and the Finnish Meteorological Institute, has been gathering similar statistics on the pipeline. The work is based on theoretical model calculations of the geoelectric field, on observatory recordings of magnetic variations, on measurements of GICs in the pipeline, and on an extension of distributed‐source transmission line (DSTL) theory.
Accurate Antarctic dating technique sought by Quaternary community
Authors: Domack Eugene , Hall Brenda , Hayes John M.
Published: October 2006

Late Quaternary paleoenvironmental records from the circum‐Antarctic and Southern Ocean play an increasing role in deciphering the interplay among the atmosphere, ocean, and cryosphere climate systems. Correlating such records at increasing time resolution is vital for evaluating the global phasing of scenarios that involve rapid climate changes in the tropics and at one or both poles. Because interhemispheric correlations are subject to greater scrutiny [Crowley, 1999] and a higher level of detail than in the past, we must be certain that our chronologies are both accurate and precise.

Although radiocarbon dating remains the single best chronologic tool for marine and terrestrial sequences, the technique has serious problems when applied to Antarctic samples. To assess the state of the problem (s), to consider potential solutions, and to review new continuous time series, a workshop was convened earlier this year.
Analysis links Pacific decadal variability to drought and streamflow in United States
Authors: Nigam Sumant , Barlow Mathew , Berbery Ernesto H.
Published: October 2006

The two leading patterns of Pacific decadal sea surface temperature (SST) variability are strongly linked to large‐scale patterns of warm‐season drought and streamflow in the United States, recent analysis shows. The predictive potential of this link may contribute to the development of warm‐season hydroclimate forecasts in the United States. Understanding of low‐frequency variations in drought and streamflow would be important for both agriculture and water resources management.

The two leading patterns are what we call the Pacific Decadal Oscillation (PDO) and the North Pacific mode. Their link with drought and streamflow patterns was notably expressed in the 1960s when severe drought in the northeast (the 1962–66 “Northeastern” drought) and exceptional positive SST anomalies in the North Pacific Ocean (Figures 1a, 1b) both occurred. Analysis of upper tropospheric circulation anomalies showed the North Pacific to be a source region of wave activity affecting the drought area in these summers. The anomalous circulation was vertically coherent and opposed the climatological low‐level moisture inflow over the eastern United States associated with the western extension of the Bermuda High.
Violent explosions yield new insights into dynamics of Stromboli volcano
Authors: Bertagnini A. , Coltelli M. , Landi P. , Pompilio M. , Rosi M.
Published: October 2006

Crystal‐poor magma may be a chief factor in the steadiness of activity at the Stromboli volcano in Italy. This was one of the findings to emerge from the documentation of a number of violent explosions there last year. The findings are giving scientists new insights into the dynamics of the volcano.

Stromboli, on an island of the same name in the Aeolian Archipelago, is known as “the lighthouse of the Mediterranean” because of its persistent explosive activity, which is visible from great distances. The well‐documented explosions, however, were more violent than normal “strombolian” activity, and we call them “paroxysmal” explosions.
New map lays out global seismic hazard values
Authors: Showstack Randy
Published: October 2006

The first‐ever quantitative Global Seismic Hazard Map, issued on December 16, provides updated seismic hazard values for nearly half of the world's nations. The map also adjusts hazard values along some politically charged international boundaries where different methods for determining seismicity had led to dissimilar values on either side of a border.

Eight percent of Earth's land mass falls within a range of high or very high seismic hazard zones on the map. That hazard is defined as a 10% or greater probability of violent shaking— which is 25% or more acceleration of gravity— within the next 50 years. About 70% of the land mass lies in a low hazard range.
Inducible Escherichia coli fermentation for increased plasmid DNA production
Authors: Carnes Aaron E. , Hodgson Clague P. , Williams James A.
Published: October 2006

Bacterial plasmids are the vectors of choice for DNA vaccines and short‐term gene therapeutics. Growing plasmid DNA by microbial (Escherichia coli) fermentation is usually combined with alkaline lysis/chromatography methods of purification. To date, typical plasmid fermentation media and processes result in yields of 100–250 mg of plasmid DNA/l of culture medium, using standard high‐copy pUC origin‐containing plasmids. In order to address this initial and yield‐limiting upstream step, we identified novel fermentation control parameters for fed‐batch fermentation. The resulting fermentation strategies significantly increased specific plasmid yield with respect to cell mass while enhancing plasmid integrity and maintaining supercoiled DNA content. Fed‐batch fermentation yield exceeding 1000 mg of plasmid DNA/l was obtained after reduction of plasmid‐mediated metabolic burden during growth, and yields up to 1500 mg of plasmid DNA/l have been achieved with optimized plasmid backbones. Interestingly, by inducing high plasmid levels after sufficient biomass accumulation at low temperature and restricted growth, cells were able to tolerate significantly higher plasmid quantities than cells grown by conventional processes. This 5–10‐fold increase in plasmid yield dramatically decreases plasmid manufacturing costs and improves the effectiveness of downstream purification by reducing the fraction of impurities.
Optimization of the conjugation method for a serogroup B/C meningococcal vaccine
Authors: Fukasawa Lucila O. , Schenkman Rocilda P. F. , Perciani Catia T. , Carneiro Sylvia M. , Dias Waldely O. , Tanizaki Martha M.
Published: October 2006

A conjugate meningococcal vaccine against serogroup B/C consisting of capsular PS (polysaccharide) from serogroup C conjugated to OMV (outer membrane vesicle) from serogroup B would be a very useful vaccine in regions where there is a prevalence of both serogroups, for example in Brazil. For this purpose, the conjugation method that uses ADHy (adipic acid dihydrazide) as spacer and a carbodi‐imide derivative, EDAC [1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodi‐imide], as catalyser was optimized looking for synthesis yield and maintenance of the antigenicity of both components. The best synthesis conditions preserving the vaccine immunogenicity resulted in a final yield of approx. 17%. Immunogenicity of the vaccine was highest when 10% of the sialic acid residues of the PS were occupied by the ADHy spacer. Sterilization of the conjugate by filtration through a 0.22‐μm‐pore‐size membrane resulted in a low recovery of protein and PS (∼50%), although the vaccine immunogenicity was maintained. Using γ irradiation on freeze‐dried sample, it was possible to maintain the integrity of OMV structure and, consequently, its ability to induce bactericidal antibodies.
The effect of shear stress on human endothelial cells seeded on cylindrical viscoelastic conduits: an investigation of gene expression
Authors: Vara Dina S. , Punshon Geoffrey , Sales Kevin M. , Hamilton George , Seifalian Alexander M.
Published: October 2006

The present study assesses the effect of physiological shear stress on gene expression from human ECs (endothelial cells) seeded on a small‐diameter cylindrical bypass graft constructed from nanocomposite based on poly(carbonate‐silsesquioxane‐bridge‐urea)urethane. ECs were seeded on to 5‐mm‐diameter conduits, placed in a physiological flow circuit and exposed to 1 or 4 h of shear stress at 1.4±0.3 Pa. Subsets of conduits were incubated at 37 °C and 5% CO2/95% O2 for a further 4 h to determine if gene expression returned to basal levels. PCR was conducted for glyceraldehyde‐3‐phosphate dehydrogenase, TGFβ‐1 (transforming growth factor β‐1), COL‐1 (collagen‐1) and PECAM‐1 (platelet/EC adhesion molecule‐1). Increases in gene expression were seen following flow in nanocomposite conduits. These were significant at 4 h for TGFβ‐1, COL‐1 and PECAM‐1. After a 4 h recovery period, there were no significant differences in gene intensity, suggesting that this change is transient. These data prove that mRNA can be obtained from ECs seeded on tubular conduits and exposed to shear stress and that gene‐expression studies can be successfully carried out. We believe this is a substantial improvement on studies based on flat sheets.
Fusion of chemotactic peptide to a single‐chain bi‐specific antibody (scBsAb) potentiates its cytotoxicity to target tumour cells
Authors: Song Jingzhen , Wang Xiangbin , Lei Chun , Piao Jinhua , Yin Changcheng , Zhang Zhong , Lin Qing , Huang Hualiang
Published: October 2006

Anti‐tumour BsAb (bi‐specific antibody) has been proved very effective in killing tumour cells both in vitro and in vivo. In order to enhance its ability to recruit and activate T‐lymphocytes and then improve tumour‐specific cytolysis, an anti‐ovarian carcinoma/CD3 BsAb, BHL‐I, was fused to N‐terminal 18 peptide of CCL21 (CC chemokine ligand 21) to produce a new chemotactic BsAb, named 18TBHL. It was expressed in soluble form in the cytoplasm of Escherichia coli and purified with DEAE anion‐exchange chromatography and immobilized‐metal‐ion affinity chromatography. The chemotactic ability of 18TBHL to PBLs (peripheral‐blood lymphocytes) was detected by Boyden chamber chemotaxis assay. The specific ability to bind to ovarian carcinoma cells, SKOV3, and PBLs was tested by ELISA and flow cytometry. Just as expected, the enhanced tumour‐specific cytolysis of 18TBHL was validated by MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide] method and flow cytometry. The results indicated that fusion of chemotactic peptide to BsAb potentiated its cytotoxicity to tumour cells in vitro. It suggests that 18TBHL may be a promising candidate agent in cancer immunotherapy.
Selective purification of supercoiled plasmid DNA from clarified cell lysates with a single histidine–agarose chromatography step
Authors: Sousa Fani , Freitas Sindélia , Azzoni Adriano R. , Prazeres Duarte Miguel F. , Queiroz João
Published: October 2006

The ability to isolate sc (supercoiled) pDNA (plasmid DNA) isoform should be one of the features of a pDNA purification process, eliminating sample contaminants such as RNA, gDNA (genomic DNA), proteins and endotoxins. A process is described that uses a single histidine–agarose chromatography step to purify sc pDNA from other isoforms and Escherichia coli impurities present in a clarified lysate. The histidine–agarose support combines the mild hydrophobic characteristics of an epoxy spacer arm with a pseudo‐affinity histidine ligand. The 6 kb DNA vaccine backbone pVAX1‐LacZ was used as a model target. Following loading at high salt [2.3 M (NH4)2SO4], the different species were eluted by a series of reverse salt step gradients (2.0, 1.5 and 0 M (NH4)2SO4). Open circular pDNA and gDNA was eluted at 2.3 M, sc pDNA was isolated as a single peak at 2.0 M and RNA was eluted at 1.5 M (NH4)2SO4 and lower. The underlying mechanism is thought to involve not only hydrophobic interactions between the support and pDNA molecules, but also non‐specific biorecognition of nucleic acid bases by the histidine ligand. Control analysis showed that the isolated sc pDNA conforms to specifications in terms of gDNA (3.4 ng/μg of pDNA), endotoxins (0.02 endotoxin unit/μg of pDNA), RNA and proteins (undetectable) and pDNA homogeneity (∼100% sc). Furthermore, the transfection efficiency of Chinese‐hamster ovary cells (50%) was significantly higher when compared with the efficiency (25%) of a pDNA control. The present study confirms the possibility of using a single histidine–agarose chromatography step to purify sc pDNA from other isoforms and host contaminants present in a clarified E. coli lysate.
Oligomerization of EDEN‐BP is required for specific mRNA deadenylation and binding
Authors: Cosson Bertrand , Gautier‐Courteille Carole , Maniey Dominique , Aït‐Ahmed Ounissa , Lesimple Michelle , Osborne H. Beverley , Paillard Luc
Published: October 2006

Background information. mRNA deadenylation [shortening of the poly(A) tail] is often triggered by specific sequence elements present within mRNA 3′ untranslated regions and generally causes rapid degradation of the mRNA. In vertebrates, many of these deadenylation elements are called AREs (AU‐rich elements). The EDEN (embryo deadenylation element) sequence is a Xenopus class III ARE. EDEN acts by binding a specific factor, EDEN‐BP (EDEN‐binding protein), which in turn stimulates deadenylation.

Results. We show here that EDEN‐BP is able to oligomerize. A 27‐amino‐acid region of EDEN‐BP was identified as a key domain for oligomerization. A mutant of EDEN‐BP lacking this region was unable to oligomerize, and a peptide corresponding to this region competitively inhibited the oligomerization of full‐length EDEN‐BP. Impairing oligomerization by either of these two methods specifically abolished EDEN‐dependent deadenylation. Furthermore, impairing oligomerization inhibited the binding of EDEN‐BP to its target RNA, demonstrating a strong coupling between EDEN‐BP oligomerization and RNA binding.

Conclusions. These data, showing that the oligomerization of EDEN‐BP is required for binding of the protein on its target RNA and for EDEN‐dependent deadenylation in Xenopus embryos, will be important for the identification of cofactors required for the deadenylation process.
Variations with altitude in reproductive traits and resource allocation of three Tibetan species of Ranunculaceae
Authors: Zhigang Zhao , Guozhen Du , Xianhui Zhou , Mantang Wang , Qingji Ren
Published: October 2006

We investigated the adaptive response of alpine plants to elevational gradients by examining reproductive traits and resource allocation of three species of Ranunculaceae with contrasting mating systems in alpine and subalpine populations on the eastern QinhaiTibetan Plateu. The results showed that (i) at alpine sites, the self-incompatible Trollius ranunculoides Hemsley tended to become limited by pollination rather than by nutrient availability, although the self-compatible Anemone rivularis var. flore-minore Maxim. Fl. Tang. and A. obtusiloba D.Don. seemed not to be limited by pollen availability; (ii) influences on the reproduction of these three species induced by high altitude were seen in different reproductive characters, and the influences were, to some extent, dependent on the plant. Female investment in the self-compatible A. rivularis and A. obtusiloba was influenced by altitude and plant size; with a much lower carpel number per flower and larger mean seed size in A. rivularis, and a much higher carpel number per flower and smaller mean seed size in A. obtusiloba, at a higher altitude. Floral investment in the self-incompatible T. ranunculoides was also influenced by altitude and plant size, with a smaller single-flower size and larger seed at the higher altitude. Results also showed that (iii) reproductive allocation to flowering and fruiting did not always decrease with altitude as predicted. This may be due to higher nutrient availability in soil at alpine sites. (iv) Although self-pollination may be an assurance mechanism alleviating pollination limitation, changes in allocation pattern, (i.e. the male-biased floral sexual allocation in A. rivularis and the higher allocation to attractive structure in A. obtusiloba) seem to promote pollinator visits at the high altitude.
Basic chromosome number in Boronia (Rutaceae)—competing hypotheses examined
Authors: Shan Fucheng , Yan Guijun , Plummer Julie A.
Published: October 2006

Rutaceae have attracted considerable attention because of the wide chromosome-number variation. Cytoevolution of the genus Boronia, with n = 7–36, has been controversial. The critical issue is whether the base chromosome number is x = 18 or x = 9 in this genus and in the family Rutaceae. Phylogenetic analysis based on random amplified polymorphic DNA (RAPD) markers was used to evaluate the hypothesis. Twenty decamer arbitrary primers were used to produce RAPD markers in 25 accessions of 18 Boronia species and a total of 559 DNA fragments was generated. UPGMA distance analysis and Wagner parsimony analysis on the DNA data produced two phylogenetic trees with very similar topology. The two trees generally supported the present classification of Boronia species. The exception was B. tenuis, which may be better treated as a new section or genus. Chromosome numbers of all the genotypes used in the analysis were counted with n = 7, 8, 9, 11, 16–36. Evolutionary distances between species were determined on the basis of branch length of the Wagner cladogram. Regression analysis indicated that Boronia chromosome number has a significant negative relationship with evolutionary distance. Chromosome number in Boronia evolved from higher to lower. The basic chromosome number for Boronia is suggested to be 18.
Pollination of Diuris maculata (Orchidaceae) by male Trichocolletes venustus bees
Authors: Indsto James O. , Weston Peter H. , Clements Mark A. , Dyer Adrian G. , Batley Michael , Whelan Robert J.
Published: October 2006

In a previous study, the Australian terrestrial orchid Diuris maculata sensu lato, from a site near Melbourne in Victoria, was suggested to be a floral mimic of several sympatric legume species. The widespread distribution of this orchid species (or species complex) suggests that there may be a number of different model and pollinator species throughout this range, and that additional studies are necessary to characterise its pollination adequately. In this study, the pollination of D. maculata in the Sydney region, mainly at Scheyville National Park, was compared with the results previously obtained in Victoria. At Scheyville National Park, Trichocolletes venustus was the only native bee species found in significant numbers, and the flowers it visited were almost exclusively the legumes Hardenbergia violacea and Daviesia ulicifolia ssp. ulicifolia. Fifty per cent (14 of 28) of captured male bees carried D. maculata orchid pollinaria, or remnants, which were identified by AFLP fingerprinting. Female bees, which appeared about 10–14 days after males, were not observed visiting the orchid or carrying orchid pollinaria. We confirmed that D. maculata flowers lack nectar, and noted that the pea-like flowers possess an UV false nectar guide comparable to the true UV nectar guide of the legume flowers. Colorimetric analysis showed the colour separation between D. ulicifolia ssp. ulicifolia and the orchid is small enough to be likely to produce foraging errors, consistent with mimicry. We conclude that guild mimicry of a diversity of ‘egg and bacon’ legumes best explains the pollination of D. maculata s.l., rather than precise mimicry of any one pea species. Preliminary observations suggest that pea-flower mimicry may range from being highly precise in some species, through to being much more generalised, but still retaining elements of mimicry. The novel finding of comparable UV patterns in Diuris species and putative pea models applies to most species in the genus and we found that the rare D. aequalis shows remarkable similarity in colour, shape and UV patterns to the sympatric legume Gompholobium huegelii, and is likely to be a mimic of this species.
It was no accident: deliberate plant introductions by Australian government agencies during the 20th century
Authors: Cook Garry D. , Dias Lesley
Published: October 2006

The weedy potential of deliberately introduced plants has been a growing concern in Australia since the late 1980s. Although introduced plants are critical to Australia’s agricultural and livestock production, many species that were praised in the past are now declared agricultural and environmental weeds. Nevertheless, weeds researchers appear largely ignorant of the magnitude and intent of plant introductions for agricultural purposes as well as the legacy of unwanted plants. Across more than 70 years, Commonwealth Plant Introductions comprised 145 000 accessions of more than 8200 species. These species include more than 2200 grass (Poaceae) and 2200 legume species (Fabaceae sensu stricto), representing about twice the indigenous flora in those families and about 22 and 18%, respectively, of the global flora of grasses and legumes. For most of the 20th century, these and other introductions supported research into continental-scale transformation of Australian landscapes to support greatly increased pastoral productivity in order to achieve policy goals of maximum density of human population. This paper documents some of the scientific developments and debates that affected the plant-introduction program. We argue that recent developments in weed science and policy need to be informed by a better understanding of plant-introduction history.
Heteropolymetallic Supramolecular Solid-State Architectures Constructed from Dicyanoaurate Ion, Phen, and 3d Metals
Authors: Xu Gong-Feng , Liu Zhan-Quan , Zhou Hui-Bo , Guo Yang , Liao Dai-Zheng
Published: October 2006

Two new supramolecular polymeric coordination complexes, {Zn(phen)2[Au2(CN)4](H2O)}·1.5H2O 1 and {Mn(phen)[Au2(CN)4](H2O)}·PriOH 2, have been obtained through a self-assembly process. The three-dimensional supramolecular architectures of compounds 1 and 2 are sustained by aurophilic, hydrogen-bonding, and/or π–π interactions. Gold atoms linked with aurophilic bonds arrange in a pattern not frequently observed.
[Zn3(HCOO)6]: A Porous Diamond Framework Conformable to Guest Inclusion
Authors: Wang Zheming , Zhang Yanjuan , Kurmoo Mohamedally , Liu Tao , Vilminot Serge , Zhao Bin , Gao Song
Published: October 2006

We report the syntheses, crystal structures, and the thermal properties of [Zn3(HCOO)6](CH3OH)1.5(H2O)0.5 (1parent), [Zn3(HCOO)6] (2empty), and six guest-inclusion compounds [Zn3(HCOO)6](I2) (3iodine), [Zn3(HCOO)6](C4H8O) (4THF), [Zn3(HCOO)6](C4H4O) (5furan), [Zn3(HCOO)6](C6H6) (6benzene), [Zn3(HCOO)6](CH3CN) (7acetonitrile), and [Zn3(HCOO)6]((CH3)2CO) (8acetone) as well as the H2 and N2 adsorption of 2empty. The frameworks of all the compounds are similar, and consist of Zn-centred ZnZn4 tetrahedral nodes of a distorted diamond structure. It is robust by virtue of the diamond structure and it displays permanent porosity in which the pores, occupying about 30% of the volume, can be reversibly emptied and refilled with solvents and gases without loss of crystallinity. The crystal-to-crystal transformation is assured by performing the guest-inclusion process by exposure of 2empty to the vapours of the guests following the complete desolvation of 1parent. Conformity is evidenced by the change in the lattice parameters proportional to the size of the guests. The framework is thermally stable up to 140°C at which it is transformed exothermically to a more compact form, β-Zn(HCOO)2, that is stable to 270°C. Due to the flexibility and amphiphilic nature of the pores, consisting of both C–H and O arrays at the surface, 2empty can take up a wide spectrum of both polar and non-polar guests of different size. The guests are confined in zig-zag molecular arrays within the channels where weak hydrogen bonds provide the main host–guest interaction. Except for acetonitrile, which sits in the central part of the channels, all the guests appear to line the wall of the channels.
Syntheses, Structures, and Luminescent Properties of Isomorphous Hydroxo-Bridged Aluminum(III) and Indium(III) Compounds with 2-(2-Hydroxyphenyl)benzimidazole
Authors: Tong Yi-Ping , Zheng Shao-Liang , Chen Xiao-Ming
Published: October 2006

Two new neutral isomorphous AlIII and InIII complexes [(M(pbm)2(μ-OH))2]·8C2H5OH·2H2O [Hpbm = 2-(2-hydroxylphenyl)benzimidazole, M = Al (1) and In (2)] featuring [M2(μ-OH)2] cores have been synthesized. The molecular orbital calculations show that the luminescent properties are π→π* transition-like in nature. The spectroscopic variations along with the effect of the metal core are also discussed.
The Absolute Stereochemistry of the Galbulimima Alkaloids
Authors: Willis Anthony C. , O'Connor Patrick D. , Taylor Walter C. , Mander Lewis N.
Published: October 2006

The X-ray crystal structures have been determined for three alkaloids isolated from the bark of the rainforest tree Galbulimima belgraveana, namely himbosine, himandrine, and himgaline, thereby allowing the absolute configuration to be established for these three compounds and 15 further alkaloids from this source.
Single Crystal to Single Crystal Structural Transformations in Molecular Framework Materials
Authors: Halder Gregory J. , Kepert Cameron J.
Published: October 2006

The rapid advance in the synthesis and characterization of molecular frameworks over the past decade has opened an entirely new approach for the generation of nanoporous materials. With this advance has come an increasingly pressing need for the development of new techniques to characterize the guest-dependent structures of these novel and highly complex materials. In this review we highlight some of the relatively rare cases where single crystal diffraction has been used to characterize the flexible structures of molecular frameworks through the investigation of single crystal to single crystal (SC-SC) transformations.
The Corallinaceae, subfamily Mastophoroideae (Corallinales, Rhodophyta) in south-eastern Australia
Authors: Harvey A. S. , Phillips L. E. , Woelkerling W. J. , Millar A. J. K.
Published: October 2006

The first monographic account of the south-eastern Australian representatives of the Corallinaceae, subfamily Mastophoroideae (Corallinales, Rhodophyta) is presented. The Mastophoroideae contains eight extant genera, four of which [Hydrolithon, Mastophora, Neogoniolithon, Pneophyllum] were confirmed to occur in south-eastern Australia. Hydrolithon is represented by six species (H. farinosum, H. improcerum, H. munitum, H. onkodes, H. rupestre and H. samoënse). Pneophyllum is represented by three species (P. coronatum, P. fragile and P. submersiporum) while Mastophora and Neogoniolithon are represented by a single species each (Mastophora pacifica and Neogoniolithon brassica-florida). Morphological and anatomical accounts are provided, including keys to genera and species, comparisons with related south-eastern Australian mastophoroid species, information on distribution, seasonality, habitat and nomenclature. Brief biogeographical comparisons between south-eastern Australia and other Australasian regions are also made.
Inner-sphere two-electron reduction leads to cleavage and functionalization of coordinated dinitrogen
Authors: Spencer Liam P. , MacKay Bruce A. , Patrick Brian O. , Fryzuk Michael D.
Published: October 2006

Activation of molecular nitrogen by transition metal complexes is an area of current interest as investigations using the inert N
2
molecule to produce higher-value organonitrogen compounds intensify. In an attempt to extend the addition of hydride reagents E-H (where E = BR
2
, AlR
2
, and SiR
3
) to the dinitrogen complex ([NPN]Ta)
2
(μ-H)
2
(μ-η
1
:η
2
-N
2
) [1; where NPN = (PhNSiMe
2
CH
2
)
2
PPh], the reaction with zirconocene chlorohydride, [Cp
2
Zr(Cl)H]
x
, was examined. The crystalline product formed in 35% yield was determined to be ([NP(N)N]Ta)(μ-H)
2
(μ-N)(Ta[NPN])(ZrCp
2
) (
2
) in which the coordinated N
2
has been cleaved to form a phosphinimide bridging between Ta and Zr and a triply bridging nitride. The mechanism of this reaction was examined to determine the fate of the chloride and hydride ligands attached to Zr in the starting zirconocene reagent. Using the zirconocene dihydride dimer ([Cp
2
ZrH
2
]
2
), a higher yield of 2 was obtained (76%), and H
2
was also observed by
1
H NMR spectroscopy. To probe the origin of the eliminated H
2
, the dideuterated dinitrogen complex ([NPN]Ta)
2
(μ-D)
2
(μ-η
1
:η
2
-N
2
) (
d
2
-1) was allowed to react with ([Cp
2
ZrH
2
]
2
), which resulted in the formation of ([NP(N)N]Ta)(μ-D)
2
(μ-N)(Ta[NPN])(ZrCp
2
), (
d
2
-2), with no evidence of hydrogen for deuterium scrambling between the starting zirconocene dihydride and the ditantalum dinitrogen complex. Studies into the use of preformed Zr(II) and Ti(II) reagents were also performed. The proposed mechanism involves initial adduct formation that facilitates inner-sphere electron transfer to cleave the N-N bond to form a species with bridging nitrides, one of which is transformed by nucleophilic attack of a phosphine donor to generate the observed phosphinimide.
FeMo cofactor maturation on NifEN
Authors: Hu Yilin , Corbett Mary C. , Fay Aaron W. , Webber Jerome A. , Hodgson Keith O. , Hedman Britt , Ribbe Markus W.
Published: October 2006

FeMo cofactor (FeMoco) biosynthesis is one of the most complicated processes in metalloprotein biochemistry. Here we show that Mo and homocitrate are incorporated into the Fe/S core of the FeMoco precursor while it is bound to NifEN and that the resulting fully complemented, FeMoco-like cluster is transformed into a mature FeMoco upon transfer from NifEN to MoFe protein through direct protein–protein interaction. Our findings not only clarify the process of FeMoco maturation, but also provide useful insights into the other facets of nitrogenase chemistry.
Caspar, a suppressor of antibacterial immunity in
Drosophila
Authors: Kim Myungjin , Lee Jun Hee , Lee Soo Young , Kim Eunhee , Chung Jongkyeong
Published: October 2006

Drosophila
has a primitive yet highly effective innate immune system. Although the infection-dependent activation mechanisms of the
Drosophila
immune system are well understood, its inhibitory regulation remains elusive. To find novel suppressors of the immune system, we performed a genetic screening for
Drosophila
mutants with hyperactivated immune responses and isolated a loss-of-function mutant of
caspar
whose product is homologous to Fas-associating factor 1 in mammals. Interestingly,
caspar
mutant flies showed increased antibacterial immune responses including increased resistance to bacterial infection and a constitutive expression of
diptericin
, a representative antibacterial peptide gene. Conversely, ectopic expression of
caspar
strongly suppressed the infection-dependent gene expression of
diptericin
, which allowed bacterial outgrowth. Consistent with these physiological phenotypes, Caspar negatively regulated the immune deficiency (Imd)-mediated immune responses by blocking nuclear translocation of Relish, an NF-κB transcription factor. In addition, we further demonstrated that Dredd-dependent cleavage of Relish, a prerequisite event for the nuclear entry of Relish, is the target of the Caspar-mediated suppression of the Imd pathway. Remarkably, Caspar was highly specific for the Imd pathway and did not affect the Toll pathway, which is crucial for antifungal immunity. Collectively, our elucidation of an inhibitory mechanism of the Imd pathway by Caspar will provide a valuable insight into understanding complex regulatory mechanisms of the innate immune systems in both
Drosophila
and mammals.
Role of ABCC1 in export of sphingosine-1-phosphate from mast cells
Authors: Mitra Poulami , Oskeritzian Carole A. , Payne Shawn G. , Beaven Michael A. , Milstien Sheldon , Spiegel Sarah
Published: October 2006

Mast cells play a pivotal role in inflammatory and immediate-type allergic reactions by secreting a variety of potent inflammatory mediators, including sphingosine-1-phosphate (S1P). However, it is not known how S1P is released from cells. Here, we report that S1P is exported from mast cells independently of their degranulation and demonstrate that it is mediated by ATP binding cassette (ABC) transporters. Constitutive and antigen-stimulated S1P release was inhibited by MK571, an inhibitor of ABCC1 (MRP1), but not by inhibitors of ABCB1 (MDR-1, P-glycoprotein). Moreover, down-regulation of ABCC1 with small interfering RNA, which decreased its cell surface expression, markedly reduced S1P export from both rat RBL-2H3 and human LAD2 mast cells. Transport of S1P by ABCC1 influenced migration of mast cells toward antigen but not degranulation. These findings have important implications for S1P functions in mast cell-mediated immune responses.
Sog/Chordin is required for ventral-to-dorsal Dpp/BMP transport and head formation in a short germ insect
Authors: Zee Maurijn van der , Stockhammer Oliver , Levetzow Cornelia von , Fonseca Rodrigo Nunes da , Roth Siegfried
Published: October 2006

Bone morphogenetic protein (BMP) signaling plays a major role in dorsoventral patterning in vertebrates and in
Drosophila
. Remarkably, in
Tribolium
, a beetle with an ancestral type of insect development, early BMP/
dpp
exhibits differential expression along the anteroposterior axis. However, the BMP/Dpp inhibitor Sog/chordin is expressed ventrally and establishes a dorsal domain of BMP/Dpp activity by transporting BMPs toward the dorsal side, like in
Drosophila
. Loss of
Tribolium
Sog not only abolishes dorsoventral polarity in the ectoderm, but also leads to the complete absence of the CNS. This phenotype suggests that
sog
is the main BMP antagonist in
Tribolium
, in contrast to vertebrates and
Drosophila
, which possess redundant antagonists. Surprisingly, Sog also is required for head formation in
Tribolium
, as are the BMP antagonists in vertebrates. Thus, in
Tribolium
, the system of BMP and its antagonists is less complex than in
Drosophila
or vertebrates and combines features from both, suggesting that it might represent an ancestral state.
Macrophage inhibitory cytokine 1 mediates a p53-dependent protective arrest in S phase in response to starvation for DNA precursors
Authors: Agarwal Mukesh K. , Hastak Kedar , Jackson Mark W. , Breit Samuel N. , Stark George R. , Agarwal Munna L.
Published: October 2006

p53 is essential for the cellular responses to DNA damage that help to maintain genomic stability. Protective p53-dependent cell-cycle checkpoints are activated in response to a wide variety of stresses, including not only DNA damage but also arrest of DNA synthesis and of mitosis. In addition to its role in activating the G
1
and G
2
checkpoints, p53 also helps to protect cells in S phase when they are starved for DNA precursors by treatment with the specific aspartate transcarbamylase inhibitor
N
-phosphonacetyl-
l
-aspartate (PALA), which blocks the synthesis of pyrimidine nucleotides. Even though p53 is activated, PALA-treated cells expressing low levels of p53 or lacking expression of p21 do not arrest in G
1
or G
2
but are blocked in S phase instead. In the complete absence of p53, PALA-treated cells continue to synthesize DNA slowly and eventually progress through S phase, suffering severe DNA damage that in turn triggers apoptosis. Expression of the secreted protein macrophage inhibitory cytokine 1 (MIC-1), a member of the TGF-β superfamily, increases substantially after PALA treatment, and application of exogenous MIC-1 or its constitutive expression from a cDNA provides remarkable protection of p53-null cells from PALA-mediated apoptosis, arguing that the p53-dependent secretion of MIC-1 provides a major part of such protection. Stimulation of MIC-1-dependent S phase arrest in normal gut epithelial cells might help to revitalize the clinical use of PALA, which has been limited by gut toxicity.
Three strategically placed hydrogen-bonding residues convert a proton pump into a sensory receptor
Authors: Sudo Yuki , Spudich John L.
Published: October 2006

In haloarchaea, light-driven ion transporters have been modified by evolution to produce sensory receptors that relay light signals to transducer proteins controlling motility behavior. The proton pump bacteriorhodopsin and the phototaxis receptor sensory rhodopsin II (SRII) differ by 74% of their residues, with nearly all conserved residues within the photoreactive retinal-binding pocket in the membrane-embedded center of the proteins. Here, we show that three residues in bacteriorhodopsin replaced by the corresponding residues in SRII enable bacteriorhodopsin to efficiently relay the retinal photoisomerization signal to the SRII integral membrane transducer (HtrII) and induce robust phototaxis responses. A single replacement (Ala-215–Thr), bridging the retinal and the membrane-embedded surface, confers weak phototaxis signaling activity, and the additional two (surface substitutions Pro-200–Thr and Val-210–Tyr), expected to align bacteriorhodopsin and HtrII in similar juxtaposition as SRII and HtrII, greatly enhance the signaling. In SRII, the three residues form a chain of hydrogen bonds from the retinal's photoisomerized C
13

C
14
double bond to residues in the membrane-embedded α-helices of HtrII. The results suggest a chemical mechanism for signaling that entails initial storage of energy of photoisomerization in SRII's hydrogen bond between Tyr-174, which is in contact with the retinal, and Thr-204, which borders residues on the SRII surface in contact with HtrII, followed by transfer of this chemical energy to drive structural transitions in the transducer helices. The results demonstrate that evolution accomplished an elegant but simple conversion: The essential differences between transport and signaling proteins in the rhodopsin family are far less than previously imagined.
Saturated fatty acids inhibit induction of insulin gene transcription by JNK-mediated phosphorylation of insulin-receptor substrates
Authors: Solinas Giovanni , Naugler Willscott , Galimi Francesco , Lee Myung-Shik , Karin Michael
Published: October 2006

JNKs are attractive targets for treatment of obesity and type-2 diabetes. A sustained increase in JNK activity was observed in dietary and genetic models of obesity in mice, whereas JNK deficiency prevented obesity-induced insulin resistance. A similar insulin-sensitizing effect was seen upon treatment of obese mice with JNK inhibitors. We now demonstrate that treatment with the saturated fatty acid palmitic acid results in sustained JNK activation and insulin resistance in primary mouse hepatocytes and pancreatic β-cells. In the latter, palmitic acid treatment inhibits glucose-induced insulin gene transcription, in part, by interfering with autocrine insulin signaling through phosphorylation of insulin-receptor substrates 1 and 2 at sites that interfere with binding to activated insulin receptors. This mechanism may account for the induction of central insulin resistance by free fatty acids.
Residential Location By Occupational Status
Authors: Wheeler James O.
Published: October 2006

Based on existing theory and limited empirical findings, it is hypothesised that groups of similar occupational status will have similar residential patterns; and, as the status level widens, location of residence will become increasingly dissimilar. To measure residential status differentiation, locational indices and correlation techniques are employed. Using Pittsburgh data, the study finds little relationship between the relative concentration of an occupational group's residence and distance from the central business district. Nevertheless, the study corroborates the generalisations of other researchers that the most segregated occupations are those at the highest and lowest ends of the socio-economic scale. Furthermore, occupations that are most alike in residential location are also similar in socio-economic rank; those with the greatest locational differences represent the extremes of status levels.
Social Class and the New Towns
Authors: Heraud B.J.
Published: October 2006

The New Towns were designed to avoid mainly working class housing and aimed to bring the social classes together in 'balanced' towns and to achieve actual social mixing at neighbourhood level. In the controversy about changes in social stratification, in particular the so called embourgeoisement of the working class, the New Towns have been held up as models in which this process is at work.

This paper examines the occupational class structures of New Towns, in particular Crawley New Town, in the light of such policies. A considerable degree of class balance has been achieved in the town as a whole but neighbourhoods have begun to take on distinctive class characteristics. However, the evidence as a whole does not justify the indiscriminate use of New Towns as 'models' for changes in the class structure. Finally, changes in policy in the New Towns are discussed in terms of the theory that British town planning is characterised by an 'adaptive mechanism' which facilitates such changes.
Threshold Analysis-an Economic Tool for Town and Regional Planning
Authors: Hughes J.T. , Kozlowski J.
Published: October 2006

This article deals with a method of increasing co-operation between physical planners and economists by development of the technique of threshold analysis. This form of analysis of planning decisions is based on the fact that the development of an urban area encounters obstacles caused by topography, the public utilities network and existing land uses. These obstacles, easily conceived of spatially, also have an economic significance in two respects; (a) capital expenditure will be necessary to overcome the threshold, (b) the threshold may mark a new, higher-cost period of development for the area.

The threshold, therefore, is a concept with significance for both planning and economic analysis. It can improve communication between the disciplines because a threshold may be designated by a line on a planning map or an inflexion point on a cost curve. Analysis of costs based on thresholds makes possible a number of insights into the efficiency of investment planning associated with development but, perhaps more important, it accommodates the economists' methodology of comparing alternatives.
Effects of Consumer Income Differences On the Business Provisions of Small Shopping Centres
Authors: Davies Ross L.
Published: October 2006

A case study is presented of the ways in which income differences between two outlying residential areas of Leeds affect the quantity and quality of shopping facilities found within them. Cursory appraisal of the stores in each area suggests their functional range of provisions and mode of business are highly similar; but more detailed classifications show important distinctions. Although there are slightly fewer establishments in the low income area than in the high income area, a much greater variety of goods and services are actually offered since the stores are less specialised in any particular trade. Broad differences in threshold values between the stores in each area are therefore perceived and varying patterns of consumer behaviour inferred. Implications for the central place farmework of a hierarchy of shopping centres are also discussed.
Tema 1951-1962: the Evolution of a Planned City in West Africa
Authors: Kirchherr E.C.
Published: October 2006

This study traces the development of a modern planned city in tropical Africa, during its first twelve years of growth. The construction of an artificial harbour and town was undertaken after World War II in connexion with the Volta River Project, though it fulfilled a long-recognised need for a port in south-eastern Ghana. Tema, a typical coastal village, was selected in 1951 because of its favourable site characteristics and its nearness to Accra. Actual development of the new city was, however, beset by a variety of problems, e.g. the lack of a single authority to integrate the planning of the harbour area and the city proper, an uncertain commitment with regard to the growth of the industrial sector, the resistance of the original Tema villagers to a government scheme for their resettlement, and constant revisions in projections of optimum population size. The port of Tema was officially opened in 1962, and the city's future as an entrepot and industrial centre now seems assured.
Code Enforcement in Urban Renewal
Authors: Case F.E.
Published: October 2006

The city of Los Angeles has used code enforcement since 1951 to rehabilitate decayed properties and to conserve older neighbourhoods. Analysis of the records from this programme provides an opportunity to examine the costs and the accomplishments of urban renewal based on building code enforcement. Quantification of the costs and benefits of the code enforcement programme indicate that measurable costs do outweigh measurable benefits but no satisfactory methods have yet been developed for measuring many kinds of important but unmeasurable costs and benefits.

Code enforcements emerges as a useful supplement to large scale land clearance and as a possible substitute under some conditions. Enforcement is most effective in areas where properties have not been neglected for too long a period of time. In older neighbourhoods of neglected properties code enforcement usually results in a high rate of property demolition. Code enforcements do offer great promise of providing a less costly and somewhat more effective means than 'bulldozer' renewal for halting and curing extensive urban blight.
Decentralisation, Decision Rules and Residential Construction in Yugoslavia
Authors: Smolensky E.
Published: October 2006

Yugoslav planners have not been able to organise the volume of residental construction to their satisfaction. This paper notes two fundamental reasons for their difficulty.

One route to an optimal amount of residential construction requires that decision-making be vested in administrative units which would not accord with political boundaries and which would have no historical antecedents. In the absence of such districts, existing administrative units would always build the correct amount of housing if they followed a particular decision rule, to maximise the social rate of return on the savings, including taxes, of their constituents. Planners have good, economic reasons, however, for choosing a different decision rule, maximising the income of their constituents. Both routes to an optimal housing policy are, therefore, effectively blocked, which is the first reason for the dissatisfaction of the planners.

A second reason must lie in the relatively high cost of construction. The empirical estimates of this paper, crude though they are, suggest that the planner must stifle his wish to encourage housing construction, for, at current costs, this would lower the national growth rate.
Private Residential Expansion in Kent 1956-64: a Study of Pattern and Process in Urban Growth
Authors: Craven Edward
Published: October 2006

This article examines the residential growth of part of the London Metropolitan Region in which the private developer has been the main supplier of housing over the last decade. American studies suggest that changes in the spatial and temporal patterns of private residential development are associated with changes in the size structure of the housebuilding industry. Therefore data from planning applications in Kent was used to discover variations in the size of sites and the type of house being built, and in the types of developer involved.

A clear trend towards larger sites and more medium density house types was found to be closely linked with the growing importance of large non-local developers throughout the county. The implications of these trends for land-use planners are discussed. Geographical dispersal of housebuilding seems an important element in the behaviour of developers. While the land market is of explanatory value in this respect, the variety of response to the same structural situation requires consideration of both the resources and values of the development companies themselves.