bluuebunny/crossref_metadata_2025 huggingface dataset:
A short‐duration global cloud‐resolving simulation with a realistic land and sea distribution
Authors: Miura Hiroaki , Satoh Masaki , Tomita Hirofumi , Noda Akira T. , Nasuno Tomoe , Iga Shin‐ichi
Published: January 2007

A global cloud‐resolving simulation with horizontal grid spacing of approximately 3.5 km was performed using a realistic land and sea distribution. Reanalysis data for 00:00 UTC on 1 April 2004 were input as the initial data. Convective systems were organized spontaneously from the coarser‐resolution data, and the development of a typhoon was reproduced; the minimum central pressure of the typhoon was approximately the same as observed. While extratropical cyclones and their fine structures were well simulated, convective clouds in the tropics were overpredicted in some regions. A sensitivity test with a horizontal grid spacing of approximately 14 km suggested that the extent of cloud organization depends on vertical moisture transport at the subgrid scale. This result suggests that appropriate representation of moisture transport from the boundary layer to the free troposphere may be essential for simulating realistic cloud systems by global cloud‐resolving models.
Diagnosing the energy cascade in a model of the North Atlantic
Authors: Schlösser F. , Eden C.
Published: January 2007

Spectral potential and kinetic energy densities and fluxes in horizontal wavenumber space are estimated in an eddy‐resolving model of the North Atlantic. In agreement to recent observational results near surface kinetic energy fluxes are negative over wide regions of the North Atlantic, indicative of an inverse energy cascade. This inverse kinetic energy cascade is found over a wide depth range but both the spectral kinetic energy density and the corresponding flux show no clear dependency on Rossby radius or Rhines scale. Potential energy fluxes tend to be positive and show a direct potential energy cascade towards a scale which is related to the Rossby radius in the subtropical North Atlantic.
Is vehicle exhaust a significant primary source of oxalic acid in ambient aerosols?
Authors: Huang Xiao‐Feng , Yu Jian Zhen
Published: January 2007

Oxalic acid is the single most abundant organic compound identified in ambient aerosols. In a previous study it was suggested that vehicular emissions were an important primary source of oxalic acid in an urban atmosphere. We here present size‐segregated measurements of oxalic acid in a road‐way tunnel and in an ambient urban environment in the Pearl River Delta Region, China, to demonstrate clearly that vehicular emissions are not a significant primary source for oxalic acid in urban aerosols. Evidence in support of this assertion includes: (1) no enhancement in oxalate levels in the tunnel aerosol was seen in comparison with the oxalate levels in the ambient environment, (2) oxalate in the tunnel samples bore little resemblance in its size distribution to that of elemental carbon and had no correlation with elemental carbon, and (3) the ratio of oxalate/elemental carbon in the tunnel samples was more than 15 times lower than that in the ambient samples.
Progressive dolomitization of Florida limestone recorded by alkaline earth element concentrations in saline, geothermal, submarine springs
Authors: Schijf Johan , Byrne Robert H.
Published: January 2007

Studies in the late 1970s revealed that the effluents of saline, geothermal, submarine springs on the West Florida Shelf have compositions nearly identical to seawater, except for distinct Ca enrichments and Mg depletions, probably resulting from dolomitization. During annual visits between 1996 and 2003 we collected high‐purity effluents from four submarine springs and from Warm Mineral Springs (WMS), which is located on land. Filtered effluents were analyzed for major ions and for Sr and Ba. These analyses confirm the seawater‐like composition of the effluents as well as the Ca enrichment and Mg depletion. The alkaline earth elements Sr and Ba, like Ca and Ra, are significantly enriched in the effluents compared to ambient seawater, by average factors of 1.6 and 3.8, respectively (about 9 and 12 for WMS). The Mg depletion, and the Sr and Ba enrichments, while invariant over the 7‐year sampling period, increase gradually from south to north, consistent with progressive dolomitization of limestone along the purported convective flow path of the warm seawater. The Ca enrichment shows no obvious trend because, besides dolomitization, gypsum dissolution is an independent source of Ca. A simple mass balance indicates that the Ca excess is fully accounted for by these two processes in all four submarine springs. This is not the case for WMS, where a residual Ca excess points to a third source of Ca, presumably limestone dissolution that occurs upon mixing of the modified seawater with fresh groundwater from the Floridan Aquifer System.
Visible and near‐infrared reflectance spectroscopy of pyroxene‐bearing rocks: New constraints for understanding planetary surface compositions
Authors: Pompilio Loredana , Sgavetti Maria , Pedrazzi Giuseppe
Published: January 2007

Laboratory visible and near‐infrared reflectance spectra of solid rock slabs, mineral separates and systematic mixtures were simultaneously investigated. We apply an empirical approach to evaluate spectra, in order to achieve qualitative and quantitative information. We use cumulates (mostly norites, leuconorites, melanorites and anorthosites) belonging to the Bjerkreim‐Sokndal Layered Intrusion, a sequence of genetically related rocks with simple textures. Laboratory spectra are measured on slightly polished rock slabs in the 350‐ to 2500‐nm interval and directional‐hemispherical reflectance geometry. Composition is determined using traditional techniques other than reflectance spectroscopy. We find that: (1) band minima measured on rock spectra are strongly influenced by the concurrent effects due to modal abundance of the spectroscopically active mineral and mineral chemistry; (2) band depths can be used for semiquantitative analyses, limited to the set of rocks investigated; (3) the spectral parameters derived from powdered pyroxene are in agreement with previously published calibrations; (4) the mineral mixture systematics can be reasonably considered as linear, when pyroxene is mixed with neutral components; and (5) the empirical evaluation of solid rock surface spectra needs further insights to give a great improvement to planetary researches. In addition, genetic sequences of rocks should be investigated in detail to help the geological interpretation of planetary evolution. Therefore more laboratory and analytical studies are required in order to understand the influence of composition and petrographic textures on the spectral analysis.
The Upregulation of Glial Glutamate Transporter-1 Participates in the Induction of Brain Ischemic Tolerance in Rats
Authors: Zhang Min , Li Wen-Bin , Geng Jin-Xia , Li Qing-Jun , Sun Xiao-Cai , Xian Xiao-Hui , Qi Jie , Li Shu-Qin
Published: January 2007

Glial glutamate transporter-1 (GLT-1) plays an essential role in removing glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. To explore whether GLT-1 plays a role in the acquisition of brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP), the present study was undertaken to observe in vivo changes in the expression of GLT-1 and glial fibrillary acidic protein (GFAP) in the CA1 hippocampus during the induction of BIT, and the effect of dihydrokainate (DHK), an inhibitor of GLT-1, on the acquisition of BIT in rats. Immunohistochemistry for GFAP showed that the processes of astrocytes were prolonged after a CIP 2 days before the lethal ischemic insult, which could protect pyramidal neurons in the CA1 hippocampus against delayed neuronal death induced normally by lethal ischemic insult. The prolonged processes extended into the area between the pyramidal neurons and tightly surrounded them. These changes made the pyramidal layer look like a ‘shape grid’. Simultaneously, the prolonged and extended processes showed a great deal of GLT-1. Western blotting analysis showed significant upregulation of GLT-1 expression after the CIP, especially when it was administered 2 days before the subsequent lethal ischemic insult. Neuropathological evaluation by thionin staining showed that DHK dose-dependently blocked the protective role of CIP against delayed neuronal death induced normally by lethal brain ischemia. It might be concluded that the surrounding of pyramidal neurons by astrocytes and upregulation of GLT-1 induced by CIP played an important role in the acquisition of the BIT induced by CIP.
Transfer printing methods for the fabrication of flexible organic electronics
Authors: Hines D. R. , Ballarotto V. W. , Williams E. D. , Shao Y. , Solin S. A.
Published: January 2007

A transfer printing method for fabricating organic electronics onto flexible substrates has been developed. The method relies primarily on differential adhesion for the transfer of a printable layer from a transfer substrate to a device substrate. The works of adhesion and cohesion for successful printing are discussed and developed for a model organic thin-film transistor device consisting of a polyethylene terephthalate (PET) substrate, gold (Au) gate and source/drain electrodes, a polymethylmethacrylate (PMMA) [or poly(4-vinylphenol)] dielectric layer, and a pentacene (Pn) organic semiconductor layer. The device components are sequentially printed onto the PET device substrate with no mixed processing steps performed on the device substrate. Optimum printing conditions for the Pn layer were determined to be 600psi and 120°C for 3min. A set of devices with a PMMA dielectric layer was measured as a function of channel length and exhibited a contact resistance corrected mobility of 0.237cm2∕Vs. This is larger than the mobility measured for a control device consisting of Pn thermally deposited onto the thermally oxidized surface of a silicon substrate (SiO2∕Si) with e-beam deposited Au top source/drain contacts. The structure of transfer printed Pn films was also investigated using x-ray diffraction. The basal spacing correlation length for a 50nm Pn film printed at 600psi and 120°C for 3min onto a PMMA surface showed a 35% increase as compared to an unprinted film on a thermally oxidized silicon substrate. The crystalline size was seen to correlate with the mobility as a function of printing conditions.
On contour arguments for the three state Potts model with competing interactions on a semi-infinite Cayley tree
Authors: Mukhamedov Farrukh , Rozikov Utkir , Mendes José F. F.
Published: January 2007

We consider the Potts model with competing two-step interactions and spin values 1, 2, 3 on a semi-infinite Cayley tree of order 2. We describe ground states and verify the Peierls condition for the model. Using a contour argument we show the existence of three different Gibbs measures associated with translation invariant ground states.
Two pathways for photon upconversion in model organic compound systems
Authors: Baluschev S. , Yakutkin V. , Wegner G. , Minch B. , Miteva T. , Nelles G. , Yasuda A.
Published: January 2007

We have studied the phenomenon of photon upconversion in systems of two model compounds as highly efficient blue emitters sensitized with metallated macrocycle molecules in thin films. The bimolecular upconversion process in these systems is based on the presence of a metastable triplet excited state of the macrocycles giving rise to dramatically different photophysical characteristics relative to the other known methods for photon upconversion such as two-photon absorption, parametric processes, second harmonic generation, and sequential multiphoton absorption. The chosen blue emitter molecules have suitably positioned triplet levels: in the case of an oligofluorine—essentially higher and in the case of diphenylanthracene—lower than the sensitizer porphyrin platinum triplet level and thus two excitation pathways for photon upconversion were observed and investigated.
Electrical and optical properties of ZnO (0001¯) wafers implanted with argon
Authors: Adekore B. T. , Davis R. F. , Barlage D. W.
Published: January 2007

The electrical and optical properties of (0001¯)-oriented ZnO wafers, implanted with argon at 230keV and dosage of 1015cm−2 have been determined to establish a baseline by which to compare these properties in similar ZnO materials implanted with other dopants. Capacitance-voltage measurements of unimplanted and implanted wafers, annealed in oxygen at 1atm at 50°C intervals between 250 and 850°C for 30min at each temperature, indicated contributions of charged point defects to the overall conductivity of the latter material. Photoluminescence data acquired at 8K of the same two material sets revealed defect bands in the implanted wafers at 2.4 and 2.25eV related to mobile point defects. The results of both studies indicated crystallographic repair of Ar-implanted ZnO commences at 400°C.
Interface roughness evolution in sputtered WSi2∕Si multilayers
Authors: Wang Yi-Ping , Zhou Hua , Zhou Lan , Headrick Randall L. , Macrander Albert T. , Özcan Ahmet S.
Published: January 2007

We report on the growth of WSi2 and Si amorphous thin films by dc magnetron sputtering. In situ synchrotron x-ray scattering with high temporal resolution has been employed to probe the surface and interface roughness during film deposition. It is found that the WSi2∕Si multilayer surface alternately roughens and smoothes during deposition; while the Si layer roughness monotonically, the WSi2 layer is observed to smooth out when deposited on an initially rough surface. Subsequent deposition of the next layer effectively freezes in the surface morphology of the previous layer in each case. Energetic neutrals and ions assisting the growth may play a role in inducing this pronounced alternating pattern in the roughness.
Steady-state isothermal bounded plasma with neutral dynamics
Authors: Raimbault J.-L. , Liard L. , Rax J.-M. , Chabert P. , Fruchtman A. , Makrinich G.
Published: January 2007

The Tonks-Langmuir, Godyak, and Schottky steady-state isothermal models are extended when the dynamics of the neutral gas is taken into account. Exact analytic quadratures for the electron temperature, densities, and potential profiles are obtained for these three models within the plasma approximation. It is shown that, contrary to the uniform neutral pressure case, the particle and the power balance are both necessary to determine the electron temperature when neutral dynamics is included. When neutral dynamics is governed by collisions with ions, the neutral density that results from ionization is predicted to have a minimum at the center of the discharge, as indeed is observed in experiment. It is found that even a small amount of ionization can result in a rather strong neutral depletion. However, when the drag on neutrals due to collisions with ions is negligible, the predicted profile of the neutral density that results from intense ionization is reversed and exhibits an unexpected maximum at the center of the discharge.
Hydration of alkali ions from first principles molecular dynamics revisited
Authors: Ikeda Takashi , Boero Mauro , Terakura Kiyoyuki
Published: January 2007

Structural and dynamical properties of the hydration of Li+, Na+, and K+ in liquid water at ambient conditions were studied by first principles molecular dynamics. Our simulations successfully captured the different hydration behavior shown by the three alkali ions as observed in experiments. The present analyses of the dependence of the self-diffusion coefficient and rotational correlation time of water on the ion concentration suggest that Li+ (K+) is certainly categorized as a structure maker (breaker), whereas Na+ acts as a weak structure breaker. An analysis of the relevant electronic structures, based on maximally localized Wannier functions, revealed that the dipole moment of H2O molecules in the first solvation shell of Na+ and K+ decreases by about 0.1 D compared to that in the bulk, due to a contraction of the oxygen lone pair orbital pointing toward the metal ion.
Implosion in water medium and its possible application for the inertial confinement fusion target ignition
Authors: Grinenko A. , Gurovich V. Tz. , Krasik Ya. E.
Published: January 2007

A numerical and self-similar analysis of the generation of implosion in water medium in cylindrical and spherical geometries is presented. The following interaction of the implosion wave with a deuterium-tritium mixture target is analyzed. It was found that the established converging cumulative water flow is self-similar, in spite of the complexity of the implied equations of state. Results of an idealized model indicate that, using a spherical geometry setup with 7.5mm external radius of the water layer and ∼35kJ total deposited energy, a ∼1.5×1014 neutron yield during ∼1.5ns time can be achieved. The obtained results suggest that ignition of deuterium-tritium target by implosion in water medium can be considered as a promising method for inertial confinement fusion.
Test charge response for a dusty plasma with both grain size distribution and dynamical charging
Authors: Raadu Michael A. , Shafiq Muhammad
Published: January 2007

The form of the grain size distribution strongly influences the linear dielectric response of a dusty plasma. For a class of size distributions and a thermal velocity distribution, there is an equivalence to a Lorentzian distribution of monosized particles. The electrostatic response to a slowly moving test charge can then be found. Dynamical charging of grains in a dusty plasma leads to an enhanced time-dependent shielding of a test charge. Here the combined effect of both grain size distribution and dynamical grain charging on the response to a slowly moving test charge is analyzed. The dynamical charging contribution to the plasma dielectric has a complicated dependence on the parameters for the size distribution and on the charging rate. However, this dependence can be expressed in terms of known functions. Series expansions are used to derive the potential response to a slowly moving test charge. Previously known results may be recovered as special limiting cases of this investigation. The analytical expression for the plasma dielectric may be used for more general cases and is applicable to the study of electrostatic waves.
Cyclotron localization in a sub-10-nm silicon quantum dot single electron transistor
Authors: Lin M. C. , Aravind K. , Wu C. S. , Wu Y. P. , Kuan C. H. , Kuo Watson , Chen C. D.
Published: January 2007

The authors have fabricated and measured a lateral Si single electron transistor consisting of a succession of a big island and small quantum dots. The big island gives rise to a small period Coulomb oscillation riding on the large irregular oscillation arising from the small quantum dots. The peaks of the latter shift in the presence of a magnetic field, which is analyzed in the context of field-induced Landau level shift with a soft-wall confinement potential. Furthermore, the current peak was suppressed for fields beyond a threshold value. An explanation based on cyclotron localization at noninteracting Landau levels is presented.
Sliding of zinc oxide nanowires on silicon substrate
Authors: Desai A. V. , Haque M. A.
Published: January 2007

Adhesion and friction forces between zinc oxide nanowires and silicon substrate were studied in situ inside a scanning electron microscope. A procedure for measuring these forces from the bending profiles of the nanowires was developed and the van der Waals and friction forces were found to be about 81.05pN and 7.7nN, respectively. The pronounced friction was explained using nanoscale adhesion-friction coupling mechanisms. Immediate implication of the findings is on the accuracy of nanomechanical characterization using bending experiments.
Broadband Mo∕Si multilayer transmission phase retarders for the extreme ultraviolet
Authors: Wang Zhanshan , Wang Hongchang , Zhu Jingtao , Zhang Zhong , Xu Yao , Zhang Shumin , Wu Wenjuan , Wang Fengli , Wang Bei , Liu Liqin , Chen Lingyan , Michette Alan G. , Pfauntsch Slawka J. , Keith Powell A. , Schäfers Franz , Gaupp Andreas , MacDonald Mike
Published: January 2007

Experimental results on aperiodic broadband transmission molybdenum/silicon multilayer phase retarders for the extreme ultraviolet range are presented. The broadband phase retarders were designed using a numerical method and made using direct current magnetron sputtering on silicon nitride membrane. The polarization properties of these aperiodic transmission phase retarders have been investigated using the soft x-ray polarimeter at BESSY-II. The measured phase shift was about 42° in the wavelength range of 13.8–15.5nm, and the corresponding s-component transmission (Ts) decreased from 6% to 2% with increasing wavelength.
Mesoscopic conductance effects in InMnAs structures
Authors: Lee S. , Trionfi A. , Schallenberg T. , Munekata H. , Natelson D.
Published: January 2007

Quantum corrections to the electrical conduction of magnetic semiconductors are comparatively unexplored. The authors report measurements of time-dependent universal conductance fluctuations (TDUCFs) and magnetic field dependent universal conductance fluctuations (MFUCFs) in micron-scale structures fabricated from two different In1−xMnxAs thin films. TDUCF and MFUCF increasing in magnitude with decreasing temperature are observed. At 4K and below, TDUCFs are suppressed at finite magnetic fields independent of field orientation.
Genetic diversity of the rare Asian plant, Trigonobalanus doichangensis (Fagaceae)
Authors: Sun Weibang , Han Chunyan , Gao Lianming , Wilson Carol A.
Published: January 2007

Trigonobalanus doichangensis is a national rare and endangered fagaceous plant of China. It is currently restricted to five sites, four in Yunnan province in south-western China and one in northern Thailand. We investigated the genetic diversity of T. doichangensis to provide information for the effective preservation of the genetic diversity of the species. Randomly amplified polymorphic DNA (RAPD) markers were used to assess the genetic variation and structure in each of the five extant populations. Sixteen primers produced 157 fragments, of which 83 (53%) were polymorphic. The estimated species diversity of T. doichangensis, although lower than for most fagaceous species, was within the range of values that have been reported for the family. The presence of private and/or uncommon fragments in each population, the presence of unique phenotypes in all individuals sampled, and estimates of relatively high populational fixation and low gene flow indicated that the species diversity present was mostly distributed among the five isolated extant populations. Pairwise genetic distances between populations were not correlated with geographical distances as depicted by the resolution of one of the Chinese populations as most similar to the Thailand population. Conservation of this species should include preservation of each of the five distinct extant populations.
Late Holocene vegetation and environments of the Mersey Valley, Tasmania
Authors: Moss Patrick T. , Thomas Ian , Macphail Michael
Published: January 2007

A record of vegetation and environmental change over the past 3000 years was obtained through pollen and charcoal analysis of sediments from a grassy plain in the Mersey Valley, Tasmania. The results tentatively suggest that Aborigines had an impact on the environment of the Mersey Valley, although the scale of the impact is difficult to quantify owing to complexities associated with the fire history and sedimentary processes. In addition, a strong regional climate signal (drier late Holocene environments) was observed, suggesting that both anthropogenic and climatic factors are required to explain pre-European environments. The study also showed the dramatic impact European settlers had on the Australian environment, with massive land clearance, introduction of exotic plant types and increased sedimentation rates.
Seed germination and seedling emergence of herbs in sand
Authors: Tobe Kazuo , Gao Yong
Published: January 2007

Laboratory experiments were carried out to examine the effects of temperature, irrigation and the depth of seed burial in sand on seed germination and seedling emergence of Astragalus adsurgens Pall. and Melilotus albus Desr. (Fabaceae), which are herbs often used to rehabilitate desertified sand dunes in China. Seeds of both species germinated well between 5 and 35°C, indicating that temperature is not a determinant of seed germination in the field for either species. For both species, seedling emergence from sand was favoured when seeds were buried at depths of 5–30 mm. Because an increase in the amount of irrigation resulted in a higher moisture content in sand and persistence of moisture in sand for a longer period, a larger amount of irrigation resulted in a larger number of seedlings emerging. Seedlings stimulated to emerge by a larger amount of irrigation survived for a longer period. It appeared in the field that light and infrequent precipitation in spring would result only in futile germination of buried seeds, and that frequent and relatively heavy precipitation in the summer rainy season would enable seedling establishment of these species.
Progressive parkinsonism in mice with respiratory-chain-deficient dopamine neurons
Authors: Ekstrand Mats I. , Terzioglu Mügen , Galter Dagmar , Zhu Shunwei , Hofstetter Christoph , Lindqvist Eva , Thams Sebastian , Bergstrand Anita , Hansson Fredrik Sterky , Trifunovic Aleksandra , Hoffer Barry , Cullheim Staffan , Mohammed Abdul H. , Olson Lars , Larsson Nils-Göran
Published: January 2007

Mitochondrial dysfunction is implicated in the pathophysiology of Parkinson′s disease (PD), a common age-associated neurodegenerative disease characterized by intraneuronal inclusions (Lewy bodies) and progressive degeneration of the nigrostriatal dopamine (DA) system. It has recently been demonstrated that midbrain DA neurons of PD patients and elderly humans contain high levels of somatic mtDNA mutations, which may impair respiratory chain function. However, clinical studies have not established whether the respiratory chain deficiency is a primary abnormality leading to inclusion formation and DA neuron death, or whether generalized metabolic abnormalities within the degenerating DA neurons cause secondary damage to mitochondria. We have used a reverse genetic approach to investigate this question and created conditional knockout mice (termed MitoPark mice), with disruption of the gene for mitochondrial transcription factor A (
Tfam
) in DA neurons. The knockout mice have reduced mtDNA expression and respiratory chain deficiency in midbrain DA neurons, which, in turn, leads to a parkinsonism phenotype with adult onset of slowly progressive impairment of motor function accompanied by formation of intraneuronal inclusions and dopamine nerve cell death. Confocal and electron microscopy show that the inclusions contain both mitochondrial protein and membrane components. These experiments demonstrate that respiratory chain dysfunction in DA neurons may be of pathophysiological importance in PD.
A trap-and-release integrated microfluidic system for dynamic microarray applications
Authors: Tan Wei-Heong , Takeuchi Shoji
Published: January 2007

Dynamic microarrays hold great promise for advancing research in proteomics, diagnostics and drug discovery. However, this potential has yet to be fully realized due to the lack of reliable multifunctional platforms to transport and immobilize particles, infuse reagents, observe the reaction, and retrieve selected particles. We achieved all these functions in a single integrated device through the combination of hydrodynamic and optical approaches. Hydrodynamic forces allow simultaneous transportation and immobilization of large number of particles, whereas optical-based microbubble technique for bead retrieval gives dexterity in handling individual particles without complicated circuitry. Based on the criterion derived in this paper, the device was designed, and fabricated using standard photolithography and soft lithography methods. We examined the dynamics of bubble formation and dissipation in the device, and parametric studies revealed that higher power settings at short intervals were more efficient than low power settings at longer intervals for bead retrieval. We also demonstrated the capabilities of our device and its potential as a tool for screening methods such as the “one-bead-one-compound” (OBOC) combinatorial library method. Although both approaches, hydrodynamic confinement and optical-based microbubbles, are presented in one device, they can also be separately used for other applications in microchip devices.
Androgen receptor decoy molecules block the growth of prostate cancer
Authors: Quayle Steven N. , Mawji Nasrin R. , Wang Jun , Sadar Marianne D.
Published: January 2007

The androgen receptor (AR) is activated by both ligand-dependent and -independent mechanisms. Current therapies for prostate cancer target the ligand-binding domain in the C terminus of the AR. However, ligand-independent activation of the AR occurs by the N-terminal domain (NTD), making the NTD a potential novel target for the treatment of hormone refractory prostate cancer. A possible therapeutic approach is to overexpress an AR NTD peptide to create decoy molecules that competitively bind the interacting proteins required for activation of the endogenous full-length AR. We provide evidence that
in vivo
expression of AR NTD decoys decreased tumor incidence and inhibited the growth of prostate cancer tumors. This growth inhibition was characterized by a 10-fold decrease in serum levels of prostate-specific antigen (PSA) (46.7 ng/ml ± 19.9 vs. 432.4 ng/ml ± 201.3;
P
= 0.0299) and a 4-fold decrease in tumor volume (92.2 mm
3
± 43.4 vs. 331.4 mm
3
± 85.5;
P
= 0.011). AR NTD decoy molecules also delayed hormonal progression, as determined by time to rising PSA levels after castration of the host. The tumors treated with AR NTD decoys contained more apoptotic cells and fewer proliferating cells, whereas no effect was seen on the viability of cells that did not depend on the AR. This work provides further evidence of the importance of the NTD of the AR in the progression of prostate cancer and presents a target for the development of antagonists of the AR in the clinical management of this disease.
Restoration of connexin26 protein level in the cochlea completely rescues hearing in a mouse model of human connexin30-linked deafness
Authors: Ahmad Shoeb , Tang Wenxue , Chang Qing , Qu Yan , Hibshman Jill , Li Yuhua , Söhl Goran , Willecke Klaus , Chen Ping , Lin Xi
Published: January 2007

Mutations in genes coding for connexin26 (Cx26) and/or Cx30 are linked to approximately half of all cases of human autosomal nonsyndromic prelingual deafness. Cx26 and Cx30 are the two major Cx isoforms found in the cochlea, and they coassemble to form hybrid (heteromeric and heterotypic) gap junctions (GJs). This molecular arrangement implies that homomeric GJs would remain in the cochlea if one of the coassembly partners were mutated resulting in null expression. We generated mice in which extra copies of the Cx26 gene were transgenically expressed from a modified bacterial artificial chromosome in a Cx30
−/−
background. In the absence of the Cx30 gene, Cx26 expressed from extra alleles completely restored hearing sensitivity and prevented hair cell death in deaf Cx30
−/−
mice. The results indicated that hybrid GJs consisting of Cx26 and Cx30 were not essential for normal hearing in mice and suggested that up-regulation of Cx26 or slowing down its protein degradation might be a therapeutic strategy to prevent and treat deafness caused by Cx30 mutations.
Induction of inducible NO synthase in bystander human T cells increases allogeneic responses in the vasculature
Authors: Choy Jonathan C. , Wang Yinong , Tellides George , Pober Jordan S.
Published: January 2007

Inducible NO synthase (iNOS) in human T cells is implicated in the pathogenesis of graft arteriosclerosis. Here we analyze the regulation and role of iNOS in human peripheral blood T cells. Allogeneic endothelial cells (EC) or dermal fibroblasts induce iNOS mRNA and protein expression, as well as enzymatic activity in primary human CD8 T cells. Although human EC activate T cells through the presentation of alloantigen, iNOS induction is confined to nonactivated T cells and does not depend on MHC molecules or costimulators. iNOS induction does involve new transcription and depends on NF-κB. JAK signaling, initiated during T cell activation, inhibits iNOS expression. Even though iNOS is confined to bystander T cells, inhibition of iNOS activity reduces T cell proliferation in response to allogeneic EC, and addition of low levels of a NO donor rescues T cell responses. Similarly, iNOS is preferentially expressed by nonproliferating T cells within allografted arteries
in vivo
, and inhibition of iNOS activity reduces the number of activated T cells in these artery segments. These data identify a previously undescribed mechanism for enhanced activation of alloreactive T cells, namely stromal cell-mediated induction of iNOS in bystander T cells.
Histoplasma capsulatumα-(1,3)-glucan blocks innate immune recognition by the β-glucan receptor
Authors: Rappleye Chad A. , Eissenberg Linda Groppe , Goldman William E.
Published: January 2007

Successful infection by fungal pathogens depends on subversion of host immune mechanisms that detect conserved cell wall components such as β-glucans. A less common polysaccharide, α-(1,3)-glucan, is a cell wall constituent of most fungal respiratory pathogens and has been correlated with pathogenicity or linked directly to virulence. However, the precise mechanism by which α-(1,3)-glucan promotes fungal virulence is unknown. Here, we show that α-(1,3)-glucan is present in the outermost layer of theHistoplasma capsulatumyeast cell wall and contributes to pathogenesis by concealing immunostimulatory β-glucans from detection by host phagocytic cells. Production of proinflammatory TNFα by phagocytes was suppressed either by the presence of the α-(1,3)-glucan layer on yeast cells or by RNA interference based depletion of the host β-glucan receptordectin-1. Thus, we have functionally defined key molecular components influencing the initial host–pathogen interaction in histoplasmosis and have revealed an important mechanism by whichH. capsulatumthwarts the host immune system. Furthermore, we propose that the degree of this evasion contributes to the difference in pathogenic potential between dimorphic fungal pathogens and opportunistic fungi.
Aberrant localization and underglycosylation of highly accumulating single-chain Fv-Fc antibodies in transgenicArabidopsisseeds
Authors: Van Droogenbroeck Bart , Cao Jingyuan , Stadlmann Johannes , Altmann Friedrich , Colanesi Sarah , Hillmer Stefan , Robinson David G. , Van Lerberge Els , Terryn Nancy , Van Montagu Marc , Liang Mifang , Depicker Ann , Jaeger Geert De
Published: January 2007

Production of high-value recombinant proteins in transgenic seeds is an attractive and economically feasible alternative to conventional systems based on mammalian cells and bacteria. In contrast to leaves, seeds allow high-level accumulation of recombinant proteins in a relatively small volume and a stable environment. We demonstrate that single-chain variable fragment (scFv)-Fc antibodies, with N-terminal signal sequence and C-terminal KDEL tag, can accumulate to very high levels as bivalent IgG-like antibodies inArabidopsis thalianaseeds and illustrate that a plant-produced anti-hepatitis A virus scFv-Fc has similar antigen-binding andin vitroneutralizing activities as the corresponding full-length IgG. As expected, most scFv-Fc produced in seeds contained only oligomannose-typeN-glycans, but, unexpectedly, 35–40% was never glycosylated. A portion of the scFv-Fc was found in endoplasmic reticulum (ER)-derived compartments delimited by ribosome-associated membranes. Additionally, consistent with the glycosylation data, large amounts of the recombinant protein were deposited in the periplasmic space, implying a direct transport from the ER to the periplasmic space between the plasma membrane and the cell wall. Aberrant localization of the ER chaperones calreticulin and binding protein (BiP) and the endogenous seed storage protein cruciferin in the periplasmic space suggests that overproduction of recombinant scFv-Fc disturbs normal ER retention and protein-sorting mechanisms in the secretory pathway.
All four CatSper ion channel proteins are required for male fertility and sperm cell hyperactivated motility
Authors: Qi Huayu , Moran Magdalene M. , Navarro Betsy , Chong Jayhong A. , Krapivinsky Grigory , Krapivinsky Luba , Kirichok Yuriy , Ramsey I. Scott , Quill Timothy A. , Clapham David E.
Published: January 2007

Mammalian spermatozoa become motile at ejaculation, but before they can fertilize the egg, they must acquire more thrust to penetrate the cumulus and zona pellucida. The forceful asymmetric motion of hyperactivated spermatozoa requires Ca
2+
entry into the sperm tail by an alkalinization-activated voltage-sensitive Ca
2+
-selective current (
I
CatSper
). Hyperactivation requires
CatSper1
and
CatSper2
putative ion channel genes, but the function of two other related genes (
CatSper3
and
CatSper4
) is not known. Here we show that targeted disruption of murine
CatSper3
or
CatSper4
also abrogated
I
CatSper
, sperm cell hyperactivated motility and male fertility but did not affect spermatogenesis or initial motility. Direct protein interactions among CatSpers, the sperm specificity of these proteins, and loss of
I
CatSper
in each of the four
CatSper
−/−
mice indicate that CatSpers are highly specialized flagellar proteins.
Peştera cu Oase 2 and the cranial morphology of early modern Europeans
Authors: Rougier Hélène , Milota Ştefan , Rodrigo Ricardo , Gherase Mircea , Sarcinǎ Laurenţiu , Moldovan Oana , Zilhão João , Constantin Silviu , Franciscus Robert G. , Zollikofer Christoph P. E. , Ponce de León Marcia , Trinkaus Erik
Published: January 2007

Between 2003 and 2005, the Peştera cu Oase, Romania yielded a largely complete early modern human cranium, Oase 2, scattered on the surface of a Late Pleistocene hydraulically displaced bone bed containing principally the remains of
Ursus spelaeus
. Multiple lines of evidence indicate an age of ≈40.5 thousand calendar years before the present (≈35 ka
14
C B.P.). Morphological comparison of the adolescent Oase 2 cranium to relevant Late Pleistocene human samples documents a suite of derived modern human and/or non-Neandertal features, including absence of a supraorbital torus, subrectangular orbits, prominent canine fossae, narrow nasal aperture, level nasal floor, angled and anteriorly oriented zygomatic bones, a high neurocranium with prominent parietal bosses and marked sagittal parietal curvature, superiorly positioned temporal zygomatic root, vertical auditory porous, laterally bulbous mastoid processes, superiorly positioned posterior semicircular canal, absence of a nuchal torus and a suprainiac fossa, and a small occipital bun. However, these features are associated with an exceptionally flat frontal arc, a moderately large juxtamastoid eminence, extremely large molars that become progressively larger distally, complex occlusal morphology of the upper third molar, and relatively anteriorly positioned zygomatic arches. Moreover, the featureless occipital region and small mastoid process are at variance with the large facial skeleton and dentition. This unusual mosaic in Oase 2, some of which is paralleled in the Oase 1 mandible, indicates both complex population dynamics as modern humans dispersed into Europe and significant ongoing human evolution once modern humans were established within Europe.
Involvement of zebrafish Na+,K+ ATPase in myocardial cell junction maintenance
Authors: Cibrián-Uhalte Elena , Langenbacher Adam , Shu Xiaodong , Chen Jau-Nian , Abdelilah-Seyfried Salim
Published: January 2007

Na+,K+ ATPase is an essential ion pump involved in regulating ionic concentrations within epithelial cells. The zebrafish heart and mind (had) mutation, which disrupts the α1B1 subunit of Na+,K+ ATPase, causes heart tube elongation defects and other developmental abnormalities that are reminiscent of several epithelial cell polarity mutants, including nagie oko (nok). We demonstrate genetic interactions between had and nok in maintaining Zonula occludens-1 (ZO-1)–positive junction belts within myocardial cells. Functional tests and pharmacological inhibition experiments demonstrate that Na+,K+ ATPase activity is positively regulated via an N-terminal phosphorylation site that is necessary for correct heart morphogenesis to occur, and that maintenance of ZO-1 junction belts requires ion pump activity. These findings suggest that the correct ionic balance of myocardial cells is essential for the maintenance of epithelial integrity during heart morphogenesis.
Nucleoplasmic LAP2α–lamin A complexes are required to maintain a proliferative state in human fibroblasts
Authors: Pekovic Vanja , Harborth Jens , Broers Jos L.V. , Ramaekers Frans C.S. , van Engelen Baziel , Lammens Martin , von Zglinicki Thomas , Foisner Roland , Hutchison Chris , Markiewicz Ewa
Published: January 2007

In human diploid fibroblasts (HDFs), expression of lamina-associated polypeptide 2 α (LAP2α) upon entry and exit from G0 is tightly correlated with phosphorylation and subnuclear localization of retinoblastoma protein (Rb). Phosphoisoforms of Rb and LAP2α are down-regulated in G0. Although RbS780 phosphoform and LAP2α are up-regulated upon reentry into G1 and colocalize in the nucleoplasm, RbS795 migrates between nucleoplasmic and speckle compartments. In HDFs, which are null for lamins A/C, LAP2α is mislocalized within nuclear aggregates, and this is correlated with cell cycle arrest and accumulation of Rb within speckles. Nuclear retention of nucleoplasmic Rb during G1 phase but not of speckle-associated Rb depends on lamin A/C. siRNA knock down of LAP2α or lamin A/C in HDFs leads to accumulation of Rb in speckles and G1 arrest, probably because of activation of a cell cycle checkpoint. Our results suggest that LAP2α and lamin A/C are involved in controlling Rb localization and phosphorylation, and a lack or mislocalization of either protein leads to cell cycle arrest in HDFs.
Mechanism of thioamide drug action against tuberculosis and leprosy
Authors: Wang Feng , Langley Robert , Gulten Gulcin , Dover Lynn G. , Besra Gurdyal S. , Jacobs William R. , Sacchettini James C.
Published: January 2007

Thioamide drugs, ethionamide (ETH) and prothionamide (PTH), are clinically effective in the treatment of Mycobacterium tuberculosis, M. leprae, and M. avium complex infections. Although generally considered second-line drugs for tuberculosis, their use has increased considerably as the number of multidrug resistant and extensively drug resistant tuberculosis cases continues to rise. Despite the widespread use of thioamide drugs to treat tuberculosis and leprosy, their precise mechanisms of action remain unknown. Using a cell-based activation method, we now have definitive evidence that both thioamides form covalent adducts with nicotinamide adenine dinucleotide (NAD) and that these adducts are tight-binding inhibitors of M. tuberculosis and M. leprae InhA. The crystal structures of the inhibited M. leprae and M. tuberculosis InhA complexes provide the molecular details of target–drug interactions. The purified ETH-NAD and PTH-NAD adducts both showed nanomolar Kis against M. tuberculosis and M. leprae InhA. Knowledge of the precise structures and mechanisms of action of these drugs provides insights into designing new drugs that can overcome drug resistance.
Stimulated Scattering Processes in Magnetized Plasmas
Authors: L Stenflo
Published: January 2007

Stimulated scattering off low frequency modes is considered for the case where the pump wave, which is assumed to be circularly polarized and to propagate parallel to an external magnetic field, is relativistically strong. The results are compared with those of non-relativistic theory in order to extend their range of validity.
Influence of Electrostatic Electron Waves on the Incoherent Scattering Cross-section
Authors: Jan Trulsen  , Noralv Bjørnå
Published: January 2007

The electrostatic dispersion relation for a magnetized electron plasma has two solutions, one of which reduces to the plasma oscillations for parallel propagation and gives rise to the wellknown plasma lines in the power spectrum of incoherent scattering. The other solution gives rise to an extra set of lines in the spectrum. Under suitable conditions these new "resonance lines" have an energy content comparable to the corresponding plasma lines and are easily observable. The enhancement of these lines due to secondary electrons is calculated.
Fine Structure Investigation for the Lower States of the Rubidium D Series
Authors: L Nilsson  , S Rydberg
Published: January 2007

The fine structure splittings for the states with principal quantum number 5 through 9 of the rubidiumDseries have been measured with high precision using a pressure-scanned Fabry-Pérot interferometer.
The Electromagnetic Field Near a Metal Surface
Authors: G Mukhopadhyay  , S Lundqvist
Published: January 2007

We have given here a formulation for calculating the electromagnetic fields near a metal surface exposed to an external radiation. For the sake of simplicity, the metal has been treated as a semi-infinite jellium with no restriction on the surface profile. The solutions of Maxwell's wave equations have been considered separately in three regions, vacuum, bulk and surface. In the first two regions, the solutions have simple forms and correspond to asymptotic forms of the electromagnetic fields. In the surface region, introducing "surface solutions" as the modifications in the fields over their asymptotic forms, an exact procedure for their determination has been developed. It is a computationally tractable method and has allowed discussions of various approximations. In particular, we have examined in detail the "surface solutions" and their physical origin, and as illustration, discussed extensively the limiting cases of semi-classical infinite barrier model, and long wavelength limit. We have shown explicitly that the surface solutions arise essentially from the particle-hole excitations.
The Continuous Optical Spectra of Active Nuclei
Authors: P A Strittmatter
Published: January 2007

The optical continuum properties of the nuclei of radio galaxies, Seyfert galaxies, N systems, BL Lac Objects, and QSOs are reviewed. The observations are in the main consistent with the hypothesis of contributions in varying degrees for a stellar component and a small non-thermal source. The presence of dust strongly influences the continuum spectrum and polarization in the case of Seyferts. The observations have not as yet led to an understanding of the nature of the non-thermal continuum source but offer prospects of so doing.
Infrared Observations of Seyfert Galaxies and Quasars
Authors: G Neugebauer
Published: January 2007

The infrared energy distributions of the Seyfert galaxies apparently contain three components: a galactic stellar component, a thermal component from heated dust, plus a nonthermal component. The appearance of the infrared energy distribution depends on which component dominates. There is also a correlation observed between the infrared energy distribution and the Khachikian Weedman class.

Preliminary data on bright quasars are given. The infrared energy distributions generally increase into the infrared with a power law slope of ∼ 1. In detail they differ from power laws with a significant fraction emitting most of their energy near 3 μm. No differences in radio loud and radio quiet are obvious from the infrared energy distributions. The variability of the quasars in the infrared is generally correlated with the variability in the visible, although significant exceptions have been observed.