bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid-infrared (4.6μm) emission properties of Pr3+ doped KPb2Br5
Authors: Hömmerich U. , Brown E. , Amedzake P. , Trivedi S. B. , Zavada J. M.
Published: December 2006

The mid-infrared (MIR) emission from Pr-doped KPb2Br5 was investigated for possible applications in solid-state lasers. Under optical pumping at 1.55 and 1.907μm, Pr-doped KPb2Br5 exhibited a broad MIR emission centered at 4.6μm, with a bandwidth of 0.9μm at full width half maximum. The dominant contribution of the MIR emission was assigned to the H53→H43 transition of Pr3+ ions. The decay time of the H53 level was measured to be 26.5ms at room temperature and remained nearly unchanged when cooling the sample to 77K. Consistent with the energy-gap law, multiphonon emission quenching is expected to be small in Pr-doped KPb2Br5. A Judd-Ofelt analysis was performed and yielded a radiative lifetime of 40.7ms for the H53 level, which suggests a radiative quantum efficiency of ∼65%. The slightly reduced quantum efficiency is most likely due to residual impurities in the crystal providing nonradiative relaxation channels. The peak emission cross section for the 4.6μm emission was calculated to be ∼0.4×10−20cm2, which compares favorable to other MIR laser transitions.
Single phase formation of Co-implanted ZnO thin films by swift heavy ion irradiation: Optical studies
Authors: Kumar Ravi , Singh Fouran , Angadi Basavaraj , Choi Ji-Won , Choi Won-Kook , Jeong Kwangho , Song Jong-Han , Khan M. Wasi , Srivastava J. P. , Kumar Ajay , Tandon R. P.
Published: December 2006

Low temperature photoluminescence and optical absorption studies on 200MeV Ag+15 ion irradiated Co-implanted ZnO thin films were studied. The Co clusters present in as implanted samples were observed to be dissolved using 200MeV Ag+15 ion irradiation with a fluence of 1×1012ions∕cm2. The photoluminescence spectrum of pure ZnO thin film was characterized by the I4 peak due to the neutral donor bound excitons and the broad green emission. The Co-doped ZnO films show three sharp levels and two shoulders corresponding to 3t2g and 2eg levels of crystal field splitted Co d orbitals, respectively. The ultraviolet-visible absorption spectroscopy also shows the systematic variation of band gap after 200MeV Ag+15 ion irradiation.
Combinational template-assisted fabrication of hierarchically ordered nanowire arrays on substrates for device applications
Authors: Chong Maria A. S. , Zheng Yue Bing , Gao Han , Tan Lee Kheng
Published: December 2006

By combining two self-organized templates, the authors fabricate hierarchically ordered nanowire arrays on substrates. The nanowire arrays consist of periodic voids at the microscale and hexagonally packed nanowires at the nanoscale. The nanowires are created by selective electrodeposition using nanoporous anodic alumina as a template and a porous gold film as a working electrode that is patterned by microsphere monolayers. In addition to in-plane hierarchical structure, they have sequentially varied the vertical structure of the nanowires. This approach is simple, inexpensive, and high throughput to fabricate nanostructures on substrates.
Methyl monolayers improve the fracture strength and durability of silicon nanobeams
Authors: Alan Tuncay , Zehnder Alan T. , Sengupta Debodhonyaa , Hines Melissa A.
Published: December 2006

Monolayer-thick coatings have a significant effect on the fracture strength and durability of 210-nm-thick, smooth (∼0.4nm rms roughness), single crystal silicon nanobeams. The initial Weibull fracture strength of beams terminated with a methyl (CH3) monolayer was 18.2GPa. This strength did not degrade after a 23-day exposure to air. In contrast, beams terminated with a monolayer of hydrogen atoms were initially weaker than methyl-terminated beams, and their strength degraded rapidly in air. After a 23-day air exposure, the strength of H-terminated beams was reduced by at least 30%. Since strength durability is correlated with the oxidation resistance of the monolayers, the degradation of H-terminated beams is attributed to the formation of oxide nuclei that act as local stress concentrators.
Concentration and saturation effects of tethered polymer chains on adsorbing surfaces
Authors: Descas Radu , Sommer Jens-Uwe , Blumen Alexander
Published: December 2006

We consider end-grafted chains at an adsorbing surface under good solvent conditions using Monte Carlo simulations and scaling arguments. Grafting of chains allows us to fix the surface concentration and to study a wide range of surface concentrations from the undersaturated state of the surface up to the brushlike regime. The average extension of single chains in the direction parallel and perpendicular to the surface is analyzed using scaling arguments for the two-dimensional semidilute surface state according to Bouchaud and Daoud [J. Phys. (Paris) 48, 1991 (1987)]. We find good agreement with the scaling predictions for the scaling in the direction parallel to the surface and for surface concentrations much below the saturation concentration (dense packing of adsorption blobs). Increasing the grafting density we study the saturation effects and the oversaturation of the adsorption layer. In order to account for the effect of excluded volume on the adsorption free energy we introduce a new scaling variable related with the saturation concentration of the adsorption layer (saturation scaling). We show that the decrease of the single chain order parameter (the fraction of adsorbed monomers on the surface) with increasing concentration, being constant in the ideal semidilute surface state, is properly described by saturation scaling only. Furthermore, the simulation results for the chains’ extension from higher surface concentrations up to the oversaturated state support the new scaling approach. The oversaturated state can be understood using a geometrical model which assumes a brushlike layer on top of a saturated adsorption layer. We provide evidence that adsorbed polymer layers are very sensitive to saturation effects, which start to influence the semidilute surface scaling even much below the saturation threshold.
Radiative relaxation and fragmentation dynamics of S 2p-excited hydrogen sulfide
Authors: Meyer M. , O’Keeffe P. , Plenge J. , Flesch R. , Rühl E.
Published: December 2006

Radiative relaxation of S 2p-excited hydrogen sulfide (H2S) is investigated by dispersed ultraviolet and visible fluorescence spectroscopies. We observe distinct changes in the fluorescence spectra as a function of excitation energy. Excitation to Rydberg states below the S 2p ionization threshold yields intense fluorescence from neutral and ionic atomic fragments (H, S+, and S2+). In addition to the atomic emission, fluorescence of the molecular fragment ion HS+ is preferably found after excitation of the S 2p electron into the unoccupied 6a1 and 3b2 orbitals with σ* character. This is interpreted as evidence for ultrafast dissociation of the core-excited molecule prior to electronic relaxation. The rotationally resolved fluorescence spectra of the AΠ3→XΣ−3 transition are analyzed in terms of the fragmentation dynamics leading to the formation of the excited molecular fragment ion, where changes in bond angle are discussed in terms of the rotational population.
Madness, Memory, Time, and Space: The Eminent Psychological Physician and the Unnamed Artist – Patient
Authors: Philo Chris
Published: December 2006

In this paper I explore the geography in the ideas of one 19th-century psychological physician, Thomas Laycock, seeking to show how his understanding of ‘madness’ rested upon an ‘imaginative historical geography’ that explained the contents of a mad person's consciousness as reversions to the mental worlds of other peoples living in other periods and places. I reconstruct Laycock's ideas about memory, notably what he understood by ‘ancestral memory’ rooted in ancestral times and spaces, and I relate these ideas to his deeper conceptualisations of the time – space fabric of creation. I also examine Laycock's approach to the letters and drawings of one unnamed artist – patient, showing that it is possible from other sources to give this patient a name (William James Blacklock) and even a ‘voice’ of sorts; and I suggest that Laycock was guilty of failing to engage properly with this evidence, yet also of overinterpreting it at the same time. Acknowledging the dangers of ‘presentism’ in this paper, I critique how Laycock's ideas captured ‘otherness’ in a grid of ‘sameness’ largely indifferent to the very different, perhaps unknowable, imaginings present in madness (and in all who depart from established norms). My contribution should be taken as a circumspect effort to write a ‘critical and effective history’ inspired by Foucault's claims in the introduction to The Order of Things (1970, Tavistock Publications, London) about the relationship between ‘the Same and the Other’.
Measuring the Soul: Psychological Technologies and the Production of Physical Health in Progressive Era America
Authors: Gagen Elizabeth A
Published: December 2006

This paper is concerned with the establishment of child psychology at the end of the 19th century and with its applied uses in the field of physical education. During this period psychology evolved from a philosophical field content with generalised statements about the human soul to a scientific field concerned with measuring and individuating the psyche. This paper focuses on how while psychology quickly laid claim to establishing the contours of normative mental health it was simultaneously deployed in the service of identifying and bolstering normative physical health. As interiority was systematically brought within the realm of science, the traditional metonymic connection between physicality and morality materialised into a new relationship between the self and its numerical existence. This relationship is explored here through an examination of physical-health testing in New York schools during the Progressive Era. My aim is to draw out the manifold ways in which psychological technologies were absorbed into spatial practice, supporting the claim of this theme issue that the proliferation of psychology can be traced through multiple governing practices and into specific geographies.
Science, Nature, and Hatred: ‘Finding Out’ at the Malting House Garden School, 1924–29
Authors: Cameron Laura
Published: December 2006

In reconfigurations of the ‘nature’ of the English child and childhood in the early 20th century a key role was played by the Malting House Garden School in Cambridge, England, founded by the unorthodox trader and inventor Geoffrey Pyke and codirected by pioneer educator and psychoanalyst Susan Isaacs. Known scurrilously in the town of Cambridge as ‘a pregenital brothel’, the Malting House School was supported by ecologist A G Tansley and psychologist Jean Piaget amongst others for its ‘copious and careful record of phenomena’. Though short lived, the Malting House School experiment became widely known through popular and influential books, written by Isaacs on early childhood development and education, based largely on data collected at the school. Less is known concerning Pyke's applications of psychoanalytic knowledge, his powerful scientific networks, and his grand vision for a new form of education. With recently recovered records and other archival documents, I seek to contribute to a historical geography of localized psychoanalytic knowledge by exploring the tangle of disciplinary relations in the mutual and imaginative constitution of two pillars of the Malting House School: natural science and psychoanalysis. In particular, I examine what Isaacs referred to as ‘the ecological point of view’ as well as the place of hatred in relation to the nursery school's attempted manufacture of infant scientists eager to ‘find out’. For Pyke, the main threat to the “vigorous survival of an intelligent bourgeoisie” was the Oedipus situation, as described by Sigmund Freud. Through new educational techniques that recognized powerful emotion between generations, Pyke sought to help mould a race that would be able to survive the great changes which he expected science to create in our environment.
“The Sensation of Infinite Vastness”; Or, the Emergence of Agoraphobia in the Late 19th Century
Authors: Callard Felicity
Published: December 2006

Agoraphobia—literally fear of the agora, the Greek place of assembly or marketplace— emerged as a named disorder in 1871 and, from the start, stymied physicians who attempted to explain its cause. They found it difficult to explain why overwhelming anxiety overtook otherwise ‘sane’ individuals in particular settings. In this paper I argue that the affective nature of agoraphobic anxiety could neither be explained by nor captured within the accounts of space perception and representation put forward in the late-19th-century clinical literature. Those accounts relied on a ‘specular’ model in which the individual was able to represent to himself or herself that which he or she perceived; in contrast, the patients' experiences of overwhelming anxiety were characterized by a temporary loss of the symbolization of spatial relations and could not, therefore, be understood within a specular economy. I read late-19th-century attempts to account for agoraphobia, then, not as exemplars in a typology of ‘psy’ practices, but, rather, as a failure of the psy complex to map the spatial coordinates of agoraphobic anxiety adequately.
Insight into the mechanism of biological methanol activation based on the crystal structure of the methanol-cobalamin methyltransferase complex
Authors: Hagemeier Christoph H. , Kr̈er Markus , Thauer Rudolf K. , Warkentin Eberhard , Ermler Ulrich
Published: December 2006

Some methanogenic and acetogenic microorganisms have the catalytic capability to cleave heterolytically the C

O bond of methanol. To obtain insight into the elusive enzymatic mechanism of this challenging chemical reaction we have investigated the methanol-activating MtaBC complex from
Methanosarcina barkeri
composed of the zinc-containing MtaB and the 5-hydroxybenzimidazolylcobamide-carrying MtaC subunits. Here we report the 2.5-Å crystal structure of this complex organized as a (MtaBC)
2
heterotetramer. MtaB folds as a TIM barrel and contains a novel zinc-binding motif. Zinc(II) lies at the bottom of a funnel formed at the C-terminal β-barrel end and ligates to two cysteinyl sulfurs (Cys-220 and Cys-269) and one carboxylate oxygen (Glu-164). MtaC is structurally related to the cobalamin-binding domain of methionine synthase. Its corrinoid cofactor at the top of the Rossmann domain reaches deeply into the funnel of MtaB, defining a region between zinc(II) and the corrinoid cobalt that must be the binding site for methanol. The active site geometry supports a S
N
2 reaction mechanism, in which the C

O bond in methanol is activated by the strong electrophile zinc(II) and cleaved because of an attack of the supernucleophile cob(I)amide. The environment of zinc(II) is characterized by an acidic cluster that increases the charge density on the zinc(II), polarizes methanol, and disfavors deprotonation of the methanol hydroxyl group. Implications of the MtaBC structure for the second step of the reaction, in which the methyl group is transferred to coenzyme M, are discussed.
Classical transient receptor potential channel 6 (TRPC6) is essential for hypoxic pulmonary vasoconstriction and alveolar gas exchange
Authors: Weissmann Norbert , Dietrich Alexander , Fuchs Beate , Kalwa Hermann , Ay Mahmut , Dumitrascu Rio , Olschewski Andrea , Storch Ursula , Mederos y Schnitzler Michael , Ghofrani Hossein Ardeschir , Schermuly Ralph Theo , Pinkenburg Olaf , Seeger Werner , Grimminger Friedrich , Gudermann Thomas
Published: December 2006

Regional alveolar hypoxia causes local vasoconstriction in the lung, shifting blood flow from hypoxic to normoxic areas, thereby maintaining gas exchange. This mechanism is known as hypoxic pulmonary vasoconstriction (HPV). Disturbances in HPV can cause life-threatening hypoxemia whereas chronic hypoxia triggers lung vascular remodeling and pulmonary hypertension. The signaling cascade of this vitally important mechanism is still unresolved. Using transient receptor potential channel 6 (TRPC6)-deficient mice, we show that this channel is a key regulator of acute HPV as this regulatory mechanism was absent inTRPC6−/−mice whereas the pulmonary vasoconstrictor response to the thromboxane mimetic U46619 was unchanged. Accordingly, induction of regional hypoventilation resulted in severe arterial hypoxemia inTRPC6−/−but not in WT mice. This effect was mirrored by a lack of hypoxia-induced cation influx and currents in smooth-muscle cells from precapillary pulmonary arteries (PASMC) ofTRPC6−/−mice. In both WT andTRPC6−/−PASMC hypoxia caused diacylglycerol (DAG) accumulation. DAG seems to exert its action via TRPC6, as DAG kinase inhibition provoked a cation influx only in WT but not inTRPC6−/−PASMC. Notably, chronic hypoxia-induced pulmonary hypertension was independent of TRPC6 activity. We conclude that TRPC6 plays a unique and indispensable role in acute hypoxic pulmonary vasoconstriction. Manipulation of TRPC6 function may thus offer a therapeutic strategy for the control of pulmonary hemodynamics and gas exchange.
The Spemann organizer gene,
Goosecoid
, promotes tumor metastasis
Authors: Hartwell Kimberly A. , Muir Beth , Reinhardt Ferenc , Carpenter Anne E. , Sgroi Dennis C. , Weinberg Robert A.
Published: December 2006

The process of invasion and metastasis during tumor progression is often reminiscent of cell migration events occurring during embryonic development. We hypothesized that genes controlling cellular changes in the Spemann organizer at gastrulation might be reactivated in tumors. The Goosecoid homeobox transcription factor is a known executer of cell migration from the Spemann organizer. We found that indeed
Goosecoid
is overexpressed in a majority of human breast tumors. Ectopic expression of Goosecoid in human breast cells generated invasion-associated cellular changes, including an epithelial–mesenchymal transition. TGF-β signaling, known to promote metastasis, induced
Goosecoid
expression in human breast cells. Moreover, Goosecoid significantly enhanced the ability of breast cancer cells to form pulmonary metastases in mice. These results demonstrate that
Goosecoid
promotes tumor cell malignancy and suggest that other conserved organizer genes may function similarly in human cancer.
Epidermal growth factor receptor tyrosine kinase is modulated by GM3 interaction with N-linked GlcNAc termini of the receptor
Authors: Yoon Seon-Joo , Nakayama Ken-ichi , Hikita Toshiyuki , Handa Kazuko , Hakomori Sen-itiroh
Published: December 2006

Epidermal growth factor receptor (EGFR) at membrane microdomains plays an essential role in the growth control of epidermal cells, including cancer cells derived therefrom. Ligand-dependent activation of EGFR tyrosine kinase is known to be inhibited by ganglioside GM3, but to a much lesser degree by other glycosphingolipids. However, the mechanism of the inhibitory effect of GM3 on EGFR tyrosine kinase has been ambiguous. The mechanism is now defined by binding of N-linked glycan having multiple GlcNAc termini to GM3 through carbohydrate-to-carbohydrate interaction, based on the following data: (
i
) EGFR (molecular mass, ≈170 kDa) has N-linked glycan with GlcNAc termini, as probed by mAb (J1) or lectin (GS-II); (
ii
) GS-II-bound EGFR also bound to anti-EGFR Ab as well as to GM3-coated beads; (
iii
) GM3 inhibitory effect on EGFR tyrosine kinase was abrogated
in vitro
by coincubation with glycan having multiple GlcNAc termini and in cell culture
in situ
incubated with the same glycan; and (
iv
) cells treated with swainsonine, which increased expression of complex-type and hybrid-type glycans with GlcNAc termini, displayed higher inhibition of EGFR kinase by GM3 than swainsonine-untreated control cells. A similar effect was observed with 1-deoxymannojirimycin, which increased hybrid-type structure in addition to major accumulation of high mannose-type glycan. These findings indicate that N-linked glycan with GlcNAc termini linked to EGFR is the target to interact with GM3, causing inhibition of EGF-induced EGFR tyrosine kinase.
Theorising Power Relationships in Multi-owned Residential Developments: Unpacking the Bundle of Rights
Authors: Blandy Sarah , Dixon Jennifer , Dupuis Ann
Published: December 2006

This article foregrounds the complex connections between property and law in the multi-owned residential sites which are becoming increasingly common in many countries. Empirical research into intensive housing developments in New Zealand and gated communities in England found that, despite differences in legal structures, individual owners often expressed frustration at their lack of control over the on-going management of such developments. This article suggests an analytical framework for considering and explaining issues of power and control amongst developers, residents and managing agents of these sites. We use the concept of the 'bundle of rights' approach to property interests and ownership to explore the importance of the right to manage. Drawing on the work of Foucault, Bourdieu, Clegg and Callon, the article tracks the transfer of power and legal rights through the critical legal events identified as taking place in the process of development and sale of multi-owned residential sites. It is suggested that these analytical tools might be useful in illuminating power relationships and legal arrangements in other urban property configurations.
Housing Commodities, Context and Meaning: Transformations in Japan's Urban Condominium Sector
Authors: Ronald Richard , Hirayama Yosuke
Published: December 2006

Japan's condominium sector expanded rapidly along with post-war urbanisation and high-speed economic growth. However, the bursting of the bubble economy in the 1990s undermined land and housing markets. Capital losses on condominiums have been disproportionate, especially in cases of older, smaller or non-centrally located condominiums. This analysis incorporates socio-cultural elements in explaining emerging patterns of fragmentation among homeowners and property values. It illustrates relationships between the meaning of housing commodities and the context of indigenous production and consumption processes in urban Japan. The paper specifically draws upon data from interviews with Japanese homeowners to illustrate the significance of values and perceptions in the modern condominium sector and their relationship to changing socioeconomic conditions.
Fourier Transform Spectroscopy of the B2Σ-X2Σ Transition of BaH
Authors: O Appelblad  , L-E Berg  , L Klynning  , J W C Johns
Published: December 2006

TheB2Σ-X2Σ band system of gaseous barium hydride in the wave length region 8900-11200 Å has been examined in absorption using a King furnace. The spectrum has been obtained by means of Fourier transform spectroscopy. Seven bands have been rotationally analyzed. Term values and molecular constants of theB2Σ andX2Σ states have been determined by standard least-squares analysis. The following molecular constants have been derived (cm-1):

TeωeωexeωeyeBeαe104×DeB2Σ+11092.5931088.89815.4710.02373.268790.070611.1585X2Σ+0.1168.43314.6110.02763.382260.065681.1234
Hibiscus sabdariffa Affects Ammonium Chloride‐Induced Hyperammonemic Rats
Authors: Essa M. Mohamed , Subramanian P.
Published: December 2006

Hibiscus sabdariffa (HS) is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt) was studied for its anti‐hyperammonemic and antioxidant effects in brain tissues of ammonium chloride‐induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight) significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non‐protein nitrogen in the blood. HSEt significantly reduced brain levels of lipid peroxidation products such as thiobarbituric acid and reactive substances (TBARS) and hydroperoxides (HP). However, the administered extract significantly increased the levels of antioxidants such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) in brain tissues of hyperammonemic rats. This investigation demonstrates significant anti‐hyperammonemic and antioxidant activity of HS.
A Diffusible Signal from Arbuscular Mycorrhizal Fungi Elicits a Transient Cytosolic Calcium Elevation in Host Plant Cells
Authors: Navazio Lorella , Moscatiello Roberto , Genre Andrea , Novero Mara , Baldan Barbara , Bonfante Paola , Mariani Paola
Published: December 2006

The implication of calcium as intracellular messenger in the arbuscular mycorrhizal (AM) symbiosis has not yet been directly demonstrated, although often envisaged. We used soybean (Glycine max) cell cultures stably expressing the bioluminescent Ca2+ indicator aequorin to detect intracellular Ca2+ changes in response to the culture medium of spores of Gigaspora margarita germinating in the absence of the plant partner. Rapid and transient elevations in cytosolic free Ca2+ were recorded, indicating that diffusible molecules released by the mycorrhizal fungus are perceived by host plant cells through a Ca2+-mediated signaling. Similar responses were also triggered by two Glomus isolates. The fungal molecules active in generating the Ca2+ transient were constitutively released in the medium, and the induced Ca2+ signature was not modified by the coculture of germinating spores with plant cells. Even ungerminated spores were able to generate the signaling molecules, as proven when the germination was blocked by a low temperature. The fungal molecules were found to be stable to heat treatment, of small molecular mass (<3 kD), and, on the basis of extraction with an organic solvent, partially lipophilic. Evidence for the specificity of such an early fungal signal to the AM symbiosis is suggested by the lack of a Ca2+ response in cultured cells of the nonhost plant Arabidopsis (Arabidopsis thaliana) and by the up-regulation in soybean cells of genes related to Medicago truncatula DMI1, DMI2, and DMI3 and considered essential for the establishment of the AM symbiosis.
Discrimination in the Dark. Resolving the Interplay between Metabolic and Physical Constraints to Phosphoenolpyruvate Carboxylase Activity during the Crassulacean Acid Metabolism Cycle
Authors: Griffiths Howard , Cousins Asaph B. , Badger Murray R. , von Caemmerer Susanne
Published: December 2006

A model defining carbon isotope discrimination (Δ13C) for crassulacean acid metabolism (CAM) plants was experimentally validated using Kalanchoe daigremontiana. Simultaneous measurements of gas exchange and instantaneous CO2 discrimination (for 13C and 18O) were made from late photoperiod (phase IV of CAM), throughout the dark period (phase I), and into the light (phase II). Measurements of CO2 response curves throughout the dark period revealed changing phosphoenolpyruvate carboxylase (PEPC) capacity. These systematic changes in PEPC capacity were tracked by net CO2 uptake, stomatal conductance, and online Δ13C signal; all declined at the start of the dark period, then increased to a maximum 2 h before dawn. Measurements of Δ13C were higher than predicted from the ratio of intercellular to external CO2 (p  i/p  a) and fractionation associated with CO2 hydration and PEPC carboxylations alone, such that the dark period mesophyll conductance, g  i, was 0.044 mol m−2 s−1 bar−1. A higher estimate of g  i (0.085 mol m−2 s−1 bar−1) was needed to account for the modeled and measured Δ18O discrimination throughout the dark period. The differences in estimates of g  i from the two isotope measurements, and an offset of −5.5‰ between the 18O content of source and transpired water, suggest spatial variations in either CO2 diffusion path length and/or carbonic anhydrase activity, either within individual cells or across a succulent leaf. Our measurements support the model predictions to show that internal CO2 diffusion limitations within CAM leaves increase Δ13C discrimination during nighttime CO2 fixation while reducing Δ13C during phase IV. When evaluating the phylogenetic distribution of CAM, carbon isotope composition will reflect these diffusive limitations as well as relative contributions from C3 and C4 biochemistry.
Heat Stress Induces an Aggregation of the Light-Harvesting Complex of Photosystem II in Spinach Plants
Authors: Tang Yunlai , Wen Xiaogang , Lu Qingtao , Yang Zhipan , Cheng Zhukuan , Lu Congming
Published: December 2006

Whole spinach (Spinacia oleracea) plants were subjected to heat stress (25°C–50°C) in the dark for 30 min. At temperatures higher than 35°C, CO2 assimilation rate decreased significantly. The maximal efficiency of photosystem II (PSII) photochemistry remained unchanged until 45°C and decreased only slightly at 50°C. Nonphotochemical quenching increased significantly either in the absence or presence of dithiothreitol. There was an appearance of the characteristic band at around 698 nm in 77 K fluorescence emission spectra of leaves. Native green gel of thylakoid membranes isolated immediately from heat-stressed leaves showed that many pigment-protein complexes remained aggregated in the stacking gel. The analyses of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting demonstrated that the aggregates were composed of the main light-harvesting complex of PSII (LHCIIb). To characterize the aggregates, isolated PSII core complexes were incubated at 25°C to 50°C in the dark for 10 min. At temperatures over 35°C, many pigment-protein complexes remained aggregated in the stacking gel of native green gel, and immunoblotting analyses showed that the aggregates were composed of LHCIIb. In addition, isolated LHCII was also incubated at 25°C to 50°C in the dark for 10 min. LHCII remained aggregated in the stacking gel of native green gel at temperatures over 35°C. Massive aggregation of LHCII was clearly observed by using microscope images, which was accompanied by a significant increase in fluorescence quenching. There was a linear relationship between the formation of LHCII aggregates and nonphotochemical quenching in vivo. The results in this study suggest that LHCII aggregates may represent a protective mechanism to dissipate excess excitation energy in heat-stressed plants.
Functional Analysis of SPINDLY in Gibberellin Signaling in Arabidopsis
Authors: Silverstone Aron L. , Tseng Tong-Seung , Swain Stephen M. , Dill Alyssa , Jeong Sun Yong , Olszewski Neil E. , Sun Tai-ping
Published: December 2006

The Arabidopsis (Arabidopsis thaliana) SPINDLY (SPY) protein negatively regulates the gibberellin (GA) signaling pathway. SPY is an O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) with a protein-protein interaction domain consisting of 10 tetratricopeptide repeats (TPR). OGTs add a GlcNAc monosaccharide to serine/threonine residues of nuclear and cytosolic proteins. Determination of the molecular defects in 14 new spy alleles reveals that these mutations cluster in three TPRs and the C-terminal catalytic region. Phenotypic characterization of 12 spy alleles indicates that TPRs 6, 8, and 9 and the catalytic domain are crucial for GA-regulated stem elongation, floral induction, and fertility. TPRs 8 and 9 and the catalytic region are also important for modulating trichome morphology and inflorescence phyllotaxy. Consistent with a role for SPY in embryo development, several alleles affect seedling cotyledon number. These results suggest that three of the TPRs and the OGT activity in SPY are required for its function in GA signal transduction. We also examined the effect of spy mutations on another negative regulator of GA signaling, REPRESSOR OF ga1-3 (RGA). The DELLA motif in RGA is essential for GA-induced proteolysis of RGA, and deletion of this motif (as in rga-Δ17) causes a GA-insensitive dwarf phenotype. Here, we demonstrate that spy partially suppresses the rga-Δ17 phenotype but does not reduce rga-Δ17 or RGA protein levels or alter RGA nuclear localization. We propose that SPY may function as a negative regulator of GA response by increasing the activity of RGA, and presumably other DELLA proteins, by GlcNAc modification.
Extracellular Proteins in Pea Root Tip and Border Cell Exudates
Authors: Wen Fushi , VanEtten Hans D. , Tsaprailis George , Hawes Martha C.
Published: December 2006

Newly generated plant tissue is inherently sensitive to infection. Yet, when pea (Pisum sativum) roots are inoculated with the pea pathogen, Nectria haematococca, most newly generated root tips remain uninfected even though most roots develop lesions just behind the tip in the region of elongation. The resistance mechanism is unknown but is correlated spatially with the presence of border cells on the cap periphery. Previously, an array of >100 extracellular proteins was found to be released while border cell separation proceeds. Here we report that protein secretion from pea root caps is induced in correlation with border cell separation. When this root cap secretome was proteolytically degraded during inoculation of pea roots with N. haematococca, the percentage of infected root tips increased from 4% ± 3% to 100%. In control experiments, protease treatment of conidia or roots had no effect on growth and development of the fungus or the plant. A complex of >100 extracellular proteins was confirmed, by multidimensional protein identification technology, to comprise the root cap secretome. In addition to defense-related and signaling enzymes known to be present in the plant apoplast were ribosomal proteins, 14-3-3 proteins, and others typically associated with intracellular localization but recently shown to be extracellular components of microbial biofilms. We conclude that the root cap, long known to release a high molecular weight polysaccharide mucilage and thousands of living cells into the incipient rhizosphere, also secretes a complex mixture of proteins that appear to function in protection of the root tip from infection.
SEF, a New Protein Required for Flowering Repression in Arabidopsis, Interacts with PIE1 and ARP6
Authors: March-Díaz Rosana , García-Domínguez Mario , Florencio Francisco J. , Reyes José C.
Published: December 2006

The SWR1/SRCAP complex is a chromatin-remodeling complex that has been shown to be involved in substitution of histone H2A by the histone variant H2A.Z in yeast (Saccharomyces cerevisiae) and animals. Here, we identify and characterize SERRATED LEAVES AND EARLY FLOWERING (SEF), an Arabidopsis (Arabidopsis thaliana) homolog of the yeast SWC6 protein, a conserved subunit of the SWR1/SRCAP complex. SEF loss-of-function mutants present a pleiotropic phenotype characterized by serrated leaves, frequent absence of inflorescence internodes, bushy aspect, and flowers with altered number and size of organs. sef plants flower earlier than wild-type plants both under inductive and noninductive photoperiods. This correlates with strong reduction of FLOWERING LOCUS C and MADS-AFFECTING FLOWERING4 transcript levels and up-regulation of FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 gene expression. The sef phenotype is similar to that of the photoperiod-independent early flowering1 (pie1) and the actin-related protein 6 (arp6) mutants. PIE1 and ARP6 proteins are also homologs of SWR1/SRCAP complex subunits. Analysis of sef pie1 double mutants demonstrates genetic interaction between these two genes. We also show physical interactions between SEF, ARP6, and PIE1 proteins. Taken together, our data indicate that SEF, ARP6, and PIE1 might form a molecular complex in Arabidopsis related to the SWR1/SRCAP complex identified in other eukaryotes.
Conservation of the Salt Overly Sensitive Pathway in Rice
Authors: Martínez-Atienza Juliana , Jiang Xingyu , Garciadeblas Blanca , Mendoza Imelda , Zhu Jian-Kang , Pardo José M. , Quintero Francisco J.
Published: December 2006

The salt tolerance of rice (Oryza sativa) correlates with the ability to exclude Na+ from the shoot and to maintain a low cellular Na+/K+ ratio. We have identified a rice plasma membrane Na+/H+ exchanger that, on the basis of genetic and biochemical criteria, is the functional homolog of the Arabidopsis (Arabidopsis thaliana) salt overly sensitive 1 (SOS1) protein. The rice transporter, denoted by OsSOS1, demonstrated a capacity for Na+/H+ exchange in plasma membrane vesicles of yeast (Saccharomyces cerevisiae) cells and reduced their net cellular Na+ content. The Arabidopsis protein kinase complex SOS2/SOS3, which positively controls the activity of AtSOS1, phosphorylated OsSOS1 and stimulated its activity in vivo and in vitro. Moreover, OsSOS1 suppressed the salt sensitivity of a sos1-1 mutant of Arabidopsis. These results represent the first molecular and biochemical characterization of a Na+ efflux protein from monocots. Putative rice homologs of the Arabidopsis protein kinase SOS2 and its Ca2+-dependent activator SOS3 were identified also. OsCIPK24 and OsCBL4 acted coordinately to activate OsSOS1 in yeast cells and they could be exchanged with their Arabidopsis counterpart to form heterologous protein kinase modules that activated both OsSOS1 and AtSOS1 and suppressed the salt sensitivity of sos2 and sos3 mutants of Arabidopsis. These results demonstrate that the SOS salt tolerance pathway operates in cereals and evidences a high degree of structural conservation among the SOS proteins from dicots and monocots.
‘GATEWAY CITIES’ IN ECONOMIC GLOBALISATION: HOW BANKS ARE USING BRAZILIAN CITIES
Authors: ROSSI ELIANA C. , TAYLOR PETER J.
Published: December 2006

The purpose of this study is to explore the concept of gateway cities as it applies under conditions of contemporary economic globalisation. A case study of Brazilian cities within domestic and global banking circles is used to show that city gateway functions in Brazil are more complex than is generally supposed. Principle components analysis of banking activity across both leading Brazilian cities and world cities generates six ‘common’ banking location strategies comprising separate subnets of cities: there are three largely regional strategies, two transnational strategies, and one national strategy. Although Sao Paulo is confirmed as the dominant gateway city in Brazil, the city subsets show a range of uses of cities by banks in Brazil including a Curitiba subnet emerging as an incipient strategy that actually bypasses Sao Paulo. The general finding is that under conditions of contemporary globalisation concentration and dispersion processes in Brazil are operating simultaneously.
Capacity of People with Intellectual Disabilities to Consent to Take Part in a Research Study
Authors: Dye Linda , Hare Dougal Julian , Hendy Steve
Published: December 2006

Background  Within the context of current legislation relating to mental capacity in adults, the capacity of people with intellectual disabilities to consent to take part in research studies and the impact of different forms of information provision was experimentally investigated.

Materials and methods  A questionnaire measure of ability to consent to take part in this research study was administered individually to participants. A total of 102 participants with intellectual disabilities were recruited from three day services for adults with intellectual disabilities. Consent information appertaining to taking part in an actual research project was presented to participants and their capacity assessed using a questionnaire. Three experimental conditions were used:

 Control (n = 34) – consent information was presented followed by the questionnaire.

 Section (n = 34) – consent information was broken into sections and the appropriate questions were asked following each section.

 Photograph (n = 34) – consent information was accompanied by six colour photographs, followed by the questionnaire.

Participants also completed measures of memory ability, verbal ability and non‐verbal problem‐solving ability.

Results  Seventeen participants withdrew from the study at some point. Of the remaining 85 participants, no significant differences in ability to consent scores were found between the experimental conditions. Using this measure, only five participants (5.9%) were deemed able to consent, i.e. scored the minimum required on each aspect of consent.

Conclusions  The validity and usefulness of the current dichotomous concept of consent is challenged as only a small proportion of participants were deemed able to consent.
A Tournament Model of Fund Management
Authors: Acker Daniella , Duck Nigel W.
Published: December 2006

Abstract:  We develop a tournament model of portfolio management and test it on UK investment trusts. Our model extends the literature by analysing middle‐ranking funds who aim to beat a benchmark; spanning two periods; focusing on ‘extreme’ portfolios; and using a signal‐extraction framework. We predict that ‘losing’ managers will adopt extreme portfolios, and increasingly so, the further behind the fund is and the nearer the ranking date. Losing managers will choose high/low market exposure depending both on anticipated market movements and on whether they have sufficient assets to take advantage of a rising market. Our empirical tests support these predictions.
Assessment and management of the severely polytraumatized small animal patient
Authors: Crowe Dennis T. (Tim)
Published: December 2006

Objective: To review the current recommendations for the care of the seriously injured polytraumatized small animal patient, including team organization and facility readiness; scene assessment and care; transport; and hospital assessment and care.

Data sources: Original research articles, scientific reviews, book chapters, and clinical experience.

Human data synthesis: The care of the seriously injured patient is demanding and requires adequate preparation, rapid access to organized resources and equipment, and skilled personnel. Second in urgency only to stabilization of the airway and breathing is shock. In many, surgical intervention to provide improved and continued stability is required. Evidence is provided by data published comparing survival for humans with high injury scores being cared for at level I trauma centers compared with small rural hospitals. Personal experience as a member of an emergency medical team in the care of multiple injured human patients in both level I trauma centers and small hospitals is also used in this review.

Veterinary data synthesis: Publications reporting large clinical series of seriously injured dogs and cats are minimal. Experimental animal models of shock caused by blood loss and the study of various organ injuries and their management are numerous. These and 35 years of the author's experience in managing severely injured dogs and cats (estimated to be >750) is also used in this review for generation of guidelines.

Conclusions: Guidelines for care of severe multiple injury patients are presented and are recommended to be used in clinical veterinary medical practice to improve outcome.
Aplasia Cutis Congenita in a Defined Population from Northwest Spain
Authors: Martinez‐Regueira Soledad , Vazquez‐Lopez Maria E. , Somoza‐Rubio Carlos , Morales‐Redondo Ramon , Gonzalez‐Gay Miguel A.
Published: December 2006

Abstract:  Aplasia cutis congenita is a rare condition characterized by congenital absence of the epidermis, dermis, and subcutaneous tissue. It may occur as an isolated defect or associated with other anomalies. This study sought to determine the frequency of this condition over a 10‐year‐period at the single hospital for a well‐defined population. A literature review of potential mechanisms implicated in the development of this condition was also conducted. A retrospective review of all case records of patients diagnosed with aplasia cutis congenita between January 1994 and December 2003 at Hospital Xeral‐Calde, in the Lugo region of northwest Spain was undertaken. During the period of study four patients were diagnosed with this condition. Three of them were of the gypsy race. These three had aplasia cutis congenita associated with epidermolysis bullosa and deformed nails. The incidence of aplasia cutis congenita in our region was 2.8 cases per 10,000 newborns. It was found that the incidence of this disorder in northwest Spain was similar to that described in the literature. Careful study due to the frequent association of aplasia cutis congenita with other congenital anomalies and a complete obstetric and family history of all affected individuals are required to identify possible specific teratogens, intrauterine infections, chromosomal abnormalities, or history of this condition among relatives.
Clinical Resolution of a Neonatally Eroded Giant Congenital Melanocytic Nevus
Authors: Gass Julia K. , Grant John W. , Hall Per N. , Atherton David J. , Burrows Nigel P.
Published: December 2006

Abstract:  We report an unusual occurrence of spontaneous pigmentary regression with a desmoplastic reaction in a neonatally eroded giant congenital melanocytic nevus. This process has been documented with photographs and skin biopsy specimens. Neonatal histology demonstrated connective tissue proliferation. Histology at age 5 years also demonstrated a very high proportion of amelanotic dermal nevus cells. Regression of pigmentation in our patient may be due to a decrease in melanin production by dermal nevus cells rather than a decrease in their number.
Effect of soluble glass bolus administration on the blood selenium concentration in grazing Philippine goats under backyard conditions
Authors: HAYASHIDA Maki , ORDEN Edgar A. , CRUZ Emilio M. , CRUZ Libertado C. , FUJIHARA Tsutomu
Published: December 2006

The present study was conducted to determine the effects of selenium (Se) soluble glass bolus (SGB) on blood Se concentrations of mixed‐bred (native × Anglo Nubian) pregnant does weighing between 15 and 52 kg and grazing on natural pastures in the Philippines. The control group, consisting of 28 does, was not administered with SGB, while 23 does were administered with SGB every 6 months for a period of 12 months. Forage and blood samples in both groups were collected every 2 months. Their Se, sulfur, calcium, phosphorus, magnesium, copper and zinc concentrations were analyzed using the wet digestion method. The results showed that the grazed forage had concentrations of all these minerals that were far higher than the accepted critical lower levels. The Se concentration was higher (P < 0.05) in the dry season than in the rainy season, especially in the whole blood collected from the does and newborn kids. In both groups the Se concentration in the kids tended to increase during the suckling period but decreased after weaning. Kids born to the SGB does had higher whole blood Se concentrations (P < 0.05) than those born to the control does. However, the administration of SGB to the does did not affect any blood mineral concentrations except for Se in the grazing does and their kids. The animals did not exhibit any clinical signs of mineral deficiencies or toxicities during the experimental period.