bluuebunny/crossref_metadata_2025 huggingface dataset:
Results of flight demonstration of terrestrial solar cells in space
Authors: Imaizumi Mitsuru , Sumita Taishi , Kawakita Shirou , Aoyama Kazuhiro , Anzawa Osamu , Aburaya Takashi , Hisamatsu Tadashi , Matsuda Sumio
Published: February 2005

Radiation resistance of six types of solar cells developed for terrestrial use has been demonstrated in space by the MDS‐1 Tsubasa satellite which flew in a geostationary transfer orbit where the radiation environment is severe. Open‐circuit voltage and short‐circuit current of the cells were monitored for duration of about 400 days after launch. Super radiation tolerance of the CuInGaSe2solar cell was demonstrated in actual space. Also, most of the cells were determined to have capability or applicability for space use. A comparison of the degradation trend of the flight data with that of ground irradiation test results using the displacement damage dose method demonstrated good agreement, indicating sufficient validity of ground‐test techniques and accuracy of the end‐of‐life prediction. Copyright © 2005 John Wiley & Sons, Ltd.
Single‐wall carbon nanotube–polymer solar cells
Authors: Landi Brian J. , Raffaelle Ryne P. , Castro Stephanie L. , Bailey Sheila G.
Published: February 2005

Investigation of single‐wall carbon nanotube (SWNT)–polymer solar cells has been conducted towards developing alternative lightweight, flexible devices for space power applications. Photovoltaic devices were constructed with regioregular poly(3‐octylthiophene)‐(P3OT) and purified, >95% w/w, laser‐generated SWNTs. The P3OT composites were deposited on ITO‐coated polyethylene terapthalate (PET) and I–V characterization was performed under simulated AM0 illumination. Fabricated devices for the 1.0% w/w SWNT–P3OT composites showed a photoresponse with an open‐circuit voltage Voc of 0.98 V and a short‐circuit current density (Isc) of 0.12 mA/cm2. Future optimization of carrier transport and exciton dissociation within these novel photovoltaic systems is proposed to derive from incorporation of nanostructure–SWNT complexes into the polymer. Copyright © 2005 John Wiley & Sons, Ltd.
Super‐high‐efficiency multi‐junction solar cells
Authors: Yamaguchi M. , Takamoto T. , Khan A. , Imaizumi M. , Matsuda S. , Ekins‐Daukes N. J.
Published: February 2005

The status of Japanese development of super‐high‐efficiency In0.49Ga0.51P/In0.01GaAs/Ge multi‐junction solar cells is reviewed. Key issues for a successful cell design are discussed, together with the technologies that have led to efficiency values of 29.1% AM0 and >36% under concentrated 400×AM1.5 illumination. The radiation resistance of the multi‐junction solar cell is discussed, showing the degradation in performance for the InGaP, InGaAs and Ge junctions. Finally, some perspectives for further multi‐junction cell development and alternative approaches to high efficiency are outlined. Copyright © 2005 John Wiley & Sons, Ltd.
Recent advances in high‐efficiencyIII–Vmulti‐junction solar cells for space applications: ultra triple junction qualification
Authors: Yoon Hojun , Granata Jennifer E. , Hebert Peter , King Richard R. , Fetzer Christopher M. , Colter Peter C. , Edmondson Kenneth M. , Law Daniel , Kinsey Geoffrey S. , Krut Dmitri D. , Ermer James H. , Gillanders Mark S. , Karam Nasser H.
Published: February 2005

Recent advances in Spectrolab's high efficiencyIII–Vmulti‐junction space solar cells are reported. The latest generation GaInP/GaAs/Ge solar cells under production—the Ultra Triple Junction (UTJ)—have an average efficiency at maximum power of 28.0% (AM0, 28°C, 135.3 mW/cm2) at beginning of life (BOL), and 22.6% at 60°C at end of life (EOL, 15 years in GEO orbit). This represents a 5.5% relative higher efficiency at EOL, compared with the previous generation Improved Triple Junction (ITJ) cells. The P/P0—for 1 MeV electrons after 1015 cm−2fluence has also improved to 0.86, compared with 0.84 for the ITJ cells. These and other performance results of UTJ solar cells are reviewed in comparison with ITJ solar cells. Copyright © 2005 John Wiley & Sons, Ltd.
Academic achievement of children in China: The 2002 Fulbright experience
Authors: Phelps LeAdelle
Published: February 2005

The 2002 Fulbright team, led by Zheng Zhou of St. John's University, consisted of 12 professionals in the fields of education, counseling psychology, and school psychology. Spending one month visiting elementary schools, universities, governmental bodies, hospitals, and private schools throughout China, the Fulbright team had an opportunity to observe educational systems and mental health services to children in multiple sites (Beijing, Kunming, Shanghai, and Suzhou). This article outlines the educational system currently utilized in China and explores the cultural factors and key variables that impact Asian children. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 233–239, 2005.
Perceptions of mathematics curricula and teaching in China
Authors: Moy Robert , Peverly Stephen T.
Published: February 2005

China and other East Asian countries (Japan, South Korea, Taiwan) have consistently outperformed the United States and other Western countries in mathematics achievement. As part of a Fulbright‐sponsored trip to China in the Summer of 2002, a New York City public school teacher and a trainer of school psychologists offer their impressions of some of the reasons for these differences. Their impressions are based on observations of schools and classrooms, review of curricula, and a review of the literature. Four areas are covered: textbooks, curricula, teaching practices, and teacher knowledge. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 251–258, 2005.
Loneliness, peer acceptance, and family functioning of Chinese children with learning disabilities: Characteristics and relationships
Authors: Yu Guoliang , Zhang Yaming , Yan Rong
Published: February 2005

Although children with learning disabilities are often considered to be a heterogeneous group, they are always situated in specific social surroundings such as schools and families with which they interact dynamically in everyday life. Therefore, peer acceptance and family functioning may be related to the loneliness experienced by children with learning disabilities. This study explores the characteristics of loneliness and peer acceptance among children with learning disabilities and discusses the relationships among loneliness, peer acceptance, and family functioning. The results indicate that children with learning disabilities reported higher degrees of loneliness, but lower levels of peer acceptance; significant correlations existed between peer acceptance and loneliness, and between peer acceptance and family functioning; however, no significant correlations were found between loneliness and family functioning. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 325–331, 2005.
Helicobacter pylori protein HP0222 belongs to Arc/MetJ family of transcriptional regulators
Authors: Popescu Andrei , Karpay Anne , Israel Dawn A. , Peek Richard M. , Krezel Andrzej M.
Published: February 2005

Helicobacter pylori is a widespread human bacterial pathogen responsible for inducing gastric and duodenal ulcers and gastric cancers. To date, only 16 protein structures from this organism have been determined, and more than 30% of its 1500 protein functions remain unknown. We report the biochemical characterization, the tertiary structure determined by solution nuclear magnetic resonance (NMR) methods and the putative function of the previously uncharacterized protein HP0222 (JHP0208) from H. pylori. Recombinant HP0222 behaves as a dimer in crosslinking and size exclusion chromatography experiments. The structure consists of a ribbon–helix–helix fold characteristic of transcription factors of the Arc/MetJ family, which all bind DNA as higher order oligomers. Electrophoretic mobility shift assays reveal that HP0222 binds to double‐stranded DNA. Previous studies have shown significant increases in transcription levels of HP0222 in response to acid shock and adherence to gastric epithelial cells. To assess possible involvement of HP0222 in acid resistance, we constructed and assayed an H. pylori HP0222 null mutant. We propose that HP0222 is a novel transcriptional regulator in H. pylori. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Thermal unfolding simulations of a multimeric protein—Transition state and unfolding pathways
Authors: Duan Jianxin , Nilsson Lennart
Published: February 2005

The folding of an oligomeric protein poses an extra challenge to the folding problem because the protein not only has to fold correctly; it has to avoid nonproductive aggregation. We have carried out over 100 molecular dynamics simulations using an implicit solvation model at different temperatures to study the unfolding of one of the smallest known tetramers, p53 tetramerization domain (p53tet). We found that unfolding started with disruption of the native tetrameric hydrophobic core. The transition state for the tetramer to dimer transition was characterized as a diverse ensemble of different structures using Φ value analysis in quantitative agreement with experimental data. Despite the diversity, the ensemble was still native‐like with common features such as partially exposed tetramer hydrophobic core and shifts in the dimer–dimer arrangements. After passing the transition state, the secondary and tertiary structures continued to unfold until the primary dimers broke free. The free dimer had little secondary structure left and the final free monomers were random‐coil like. Both the transition states and the unfolding pathways from these trajectories were very diverse, in agreement with the new view of protein folding. The multiple simulations showed that the folding of p53tet is a mixture of the framework and nucleation‐condensation mechanisms and the folding is coupled to the complex formation. We have also calculated the entropy and effective energy for the different states along the unfolding pathway and found that the tetramerization is stabilized by hydrophobic interactions. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Molecular dynamics simulation of sucrose‐ and trehalose‐coated carboxy‐myoglobin
Authors: Cottone G. , Giuffrida S. , Ciccotti G. , Cordone L.
Published: February 2005

We performed a room temperature molecular dynamics (MD) simulation on a system containing 1 carboxy‐myoglobin (MbCO) molecule in a sucrose–water matrix of identical composition (89% [sucrose/(sucrose + water)] w/w) as for a previous trehalose–water–MbCO simulation (Cottone et al., Biophys J 2001;80:931–938). Results show that, as for trehalose, the amplitude of protein atomic mean‐square fluctuations, on the nanosecond timescale, is reduced with respect to aqueous solutions also in sucrose. A detailed comparison as a function of residue number evidences mobility differences along the protein backbone, which can be related to a different efficacy in bioprotection. Different heme pocket structures are observed in the 2 systems. The joint distribution of the magnitude of the electric field at the CO oxygen atom and of the angle between the field and the CO unit vector shows a secondary maximum in sucrose, absent in trehalose. This can explain the CO stretching band profile (A substates distribution) differences evidenced by infrared spectroscopy in sucrose‐ and trehalose‐coated MbCO (Giuffrida et al., J Phys Chem B 2004;108:15415–15421), and in particular the appearance of a further substate in sucrose. Analysis of hydrogen bonds at the protein–solvent interface shows that the fraction of water molecules shared between the protein and the sugar is lower in sucrose than in trehalose, in spite of a larger number of water molecules bound to the protein in the former system, thus indicating a lower protein–matrix coupling, as recently observed by Fourier transform infrared (FTIR) experiments (Giuffrida et al., J Phys Chem B 2004;108:15415–15421). Proteins 2005. © 2005 Wiley‐Liss, Inc.
Control of 3C–SiC/Si wafer bending by the “checker‐board” carbonization method
Authors: Chassagne T. , Ferro G. , Haas H. , Mank H. , Leycuras A. , Monteil Y. , Soares F. , Balloud C. , Arcade Ph. , Blanc C. , Peyre H. , Juillaguet S. , Camassel J.
Published: February 2005

Due to the large difference in lattice parameters and thermal expansion coefficients, the hetero‐epi‐ taxial growth of 3C–SiC on Si mainly results in highly defective layers on strongly bent wafers. The defects may not be detrimental for very basic applications, but the bow is. In order to solve this problem, we have developed a technique called “checker‐board” carbonization which, basically, balances a compressive (interfacial) stress by a tensile one. In this way, the overall bending is effectively reduced. In this work, we will report on the effect of polishing the thick, as‐grown, 3C–SiC layers deposited on top and results from, both, infrared and Raman spectroscopy collected on 35 mm diameter wafers will be presented. From DDX and low temperature photoluminescence measurements, we will show that a similar 3C–SiC quality can be achieved on, both, parts of the initially compressive and tensile re‐grown layers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical mapping of aluminum doped p‐type SiC wafers
Authors: Wellmann P. J. , Straubinger T. , Künecke U. , Müller R. , Sakwe S. A. , Pons M. , Thuaire A. , Crisci A. , Mermoux M. , Auvray L. , Camassel J.
Published: February 2005

We discuss the application of optical techniques to address the spatial distribution of electronic properties of highly aluminum doped p‐type SiC wafers; optical techniques are superior over their electrical counterparts in a sense that they are non‐destructive. While absorption and birefringence mapping are powerful tools to determine the homogeneity of charge carrier concentration and defects in n‐type SiC, respectively, the same methods fail in highly p‐type doped SiC due to the opaque nature of the latter. Therefore reflective methods like Raman spectroscopy and low temperature photoluminescence have to be applied in order to address electronic properties by optical techniques. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization of InAsSb photodetector for non‐cryogenic operation in the mid‐infrared range
Authors: Aït‐Kaci H. , Nieto J. , Rodriguez J. B. , Grech P. , Chevrier F. , Salesse A. , Joullié A. , Christol P.
Published: February 2005

We present an InAsSb interband photodetector grown by molecular beam epitaxy on GaSb substrate which operates in the mid‐infrared domain (3–5 µm). To achieve uncooled high performance detection, the design of the structure was optimized to reduce the noise‐inducing currents due to generation‐recombination processes and diffusion currents. The technological procedure was further improved by using alkali sulfur passivation that suppresses surface leakage currents along the mesa edges. As a first result, the room temperature detectivity D* of the InAsSb photodiode, extracted from measurements, is comparable to the commercial HgCdTe device with a detectivity equals to 1 × 1010 cm Hz1/2 W–1 at about 3.5 µm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Increasing throughput and information content for in vitro drug metabolism experiments using ultra‐performance liquid chromatography coupled to a quadrupole time‐of‐flight mass spectrometer
Authors: Castro‐Perez Jose , Plumb Robert , Granger Jennifer H. , Beattie Iain , Joncour Karine , Wright Andrew
Published: February 2005

The field of drug metabolism has been revolutionized by liquid chromatography/mass spectrometry (LC/MS) applications with new technologies such as triple quadrupoles, ion traps and time‐of‐flight (ToF) instrumentation. Over the years, these developments have often relied on the improvements to the mass spectrometer hardware and software, which has allowed users to benefit from lower levels of detection and ease‐of‐use. One area in which the development pace has been slower is in high‐performance liquid chromatography (HPLC). In the case of metabolite identification, where there are many challenges due to the complex nature of the biological matrices and the diversity of the metabolites produced, there is a need to obtain the most accurate data possible. Reactive or toxic metabolites need to be detected and identified as early as possible in the drug discovery process, in order to reduce the very costly attrition of compounds in late‐phase development. High‐resolution, exact mass measurement plays a very important role in metabolite identification because it allows the elimination of false positives and the determination of non‐trivial metabolites in a much faster throughput environment than any other standard current methodology available to this field. By improving the chromatographic resolution, increased peak capacity can be achieved with a reduction in the number of co‐eluting species leading to superior separations. The overall enhancement in the chromatographic resolution and peak capacity is transferred into a net reduction in ion suppression leading to an improvement in the MS sensitivity. To investigate this, a number of in vitro samples were analyzed using an ultra‐performance liquid chromatography (UPLC) system, with columns packed with porous 1.7 μm particles, coupled to a hybrid quadrupole time‐of‐flight (ToF) mass spectrometer. This technique showed very clear examples for fundamental gains in sensitivity, chromatographic resolution and speed of analysis, which are all important factors for the demands of today's HTS in discovery. Copyright © 2005 John Wiley & Sons, Ltd.
Further results on global stabilization of uncertain nonlinear systems by output feedback
Authors: Yang Bo , Lin Wei
Published: February 2005

For a family of uncertain nonlinear systems dominated by a triangular system that satisfies linear growth condition with an output dependent growth rate, we prove that global robust stabilization can be achieved by smooth output feedback. This conclusion has incorporated and generalized the recent output feedback stabilization results, for instance, the work (IEEE Trans. Automat. Control2002;47:2068–2073) where the same conclusion was already shown to be true for planar systems, and the work (Proceedings of the 42nd IEEE, CDC, 2003; 1544–1549) where the growth rate is required to be a polynomial function of the system output. There are two key ingredients in the present contribution. One of them is the introduction of a rescaling transformation with a dynamic factor that is tuned on‐line through a Riccati‐like differential equation, which turns out to be extremely effective in dealing with the system uncertainty. The other one is the development of a recursive observer design algorithm making it possible to assign the robust observer gains in a step‐by‐step fashion. Both a smooth state feedback controller and a robust observer are explicitly constructed for the rescaled system using only the knowledge of the bounding system. Copyright © 2005 John Wiley & Sons, Ltd.
On the synthesis of robust PID controllers for plants with structured and unstructured uncertainty
Authors: Ho Ming‐Tzu , Huang Sheng‐Tsai
Published: February 2005

In this paper, we consider the problems of synthesizing PID controllers for robust stability and performance for a given linear time‐invariant plant subject to both parametric andH∞‐norm‐bounded perturbations. Using results from the area of parametric robust control, synthesis problems are converted into simultaneous stabilization of a family of complex segment polynomials. The results onH∞PID synthesis are then used to devise a design procedure for determining the admissible PID gain values. One of the important features of the proposed method is that it constructively characterizes the approximated set of all admissible PID controllers. This characterization can facilitate the optimal design of any additional design requirements. Copyright © 2005 John Wiley & Sons, Ltd.
ToF‐SIMS studies of the oxidation of Fe by D2O vapour: comparison with XPS
Authors: Grosvenor A. P. , Francis J. T. , Kobe B. A. , McIntyre N. S.
Published: February 2005

The oxidation of iron (Fe) by water (D2O) vapour at low pressures and room temperature was investigated using time‐of‐flight (ToF) SIMS. The results supported those found previously using XPS and the QUASES™ program in that a duplex oxide structure was found containing a thin outer surface hydroxide (Fe(OD)2) layer over an inner oxide (FeO) layer. The extraordinary depth resolution of the ToF‐SIMS profiles assisted in identifying the two phases; this resolution was achieved by compensation for surface roughness. A substantial concentration of deuterium was found in the subsurface oxide layer. This observation confirmed previous assessments that the formation of FeO was from the reaction of Fe(OD)2 with outward‐diffusing Fe, leaving deuterium as a reaction product. Copyright © 2005 John Wiley & Sons, Ltd.
Modulation of maize roots H+-ATPase by sulfated polysaccharides
Authors: Landeira-Fernandez Ana Maria , Costa Maricilia S. , de Meis Leopolde
Published: February 2005

Vesicles derived from maize roots retain a membrane bound H+-ATPase that is able to pump H+ at the expense of ATP hydrolysis. In this work it is shown that heparin, fucose-branched chondroitin sulfate and dextran sulfate 8000 promote a shift of the H+-ATPase optimum pH from 6.0 to 7.0. This shift is a result of a dual effect of the sulfated polysaccharides, inhibition at pH 6.0 and activation at pH 7.O. At pH 6.0 dextran 8000 promotes an increase of the apparent Km for ATP from 0.28 to 0.95 mM and a decrease of the Vmax from 14.5 to 7.1 μmol Pi/mg · 30 min−1. At pH 7.0 dextran 8000 promotes an increase in Vmax from 6.7 to 11.7 μmol Pi/mg · 30 min−1. In the presence of lysophosphatidylcholine the inhibitory effect of the sulfated polysaccharides observed at pH 6.0 was not altered but the activation of pH 7.0 decreased. It was found that in the presence of sulfated polysaccharides the ATPase became highly sensitive to K+ and Na+. Both the inhibition at pH 6.0 and the activation promoted by the polysaccharide were antagonized by monovalent cations (K+>Na+≫Li+).
Semliki forest virus capsid protein inhibits the initiation of translation by upregulating the double-stranded RNA-activated protein kinase (PKR)
Authors: Favre Daniel , Studer Erwin , Michel Marcel R.
Published: February 2005

We investigated the possible translational role which elevated concentrations of highly purified Semliki Forest virus (SFV) capsid (C)-protein molecules may play in a cell-free translation system. Here we decomonstrate that in the absence of double-stranded RNA high concentrations of C protein triggered the phosphorylation of the interferon-induced, double-stranded RNA-activated protein kinase, PKR. Activated PKR in turn phosphorylated its natural substrate, the α subunit of eukaryotic initiation factor 2 (eIF-2), thereby inhibiting initiation of host cell translation. These findings were further strengthened by experiments showing that during natural infection with SFV the maximum phosphorylation of PKR coincided with the maximum synthesis of C protein 4–9 hours post infection. Thus, our results demonstrate that high concentrations of C-protein molecules may act in a hitherto novel mechanism on PKR to inhibit host cell protein synthesis during viral infection.
Dimethyl sulphoxide: A review of its applications in cell biology
Authors: Yu Zhi -Wu , Quinn Peter J.
Published: February 2005

Dimethyl sulphoxide is a water miscible solvent that has wide applications in cell biology. It acts as a cryoprotective agent in a variety of cells and tissues allowing prolonged storage at subzero temperatures. The action of dimethyl sulphoxide on the stability of the liquid matrix of cell membranes appears to be responsible for its effects and this appears also to be true for related effects on membrane permeability and fusion. Dimethyl sulphoxide is also known to act as an inducer of cellular differentiation and as a free radical scavenger and radioprotectant. A review of the underlying molecular basis of all these effects of dimethyl sulphoxide is presented.
Inhibition of cell cycle progression by sodium butyrate in normal rat kidney fibroblasts is altered by expression of the adenovirus 5 early 1A gene
Authors: Joensuu Timo , Mester Jan
Published: February 2005

The effect of sodium butyrate (NaBut) on cell growth was studied in normal rat kidney (NRK) fibroblasts, and in NRK cells stably transfected with either the adenoviral gene E1A (wild-type), or mutated E1A (E1Amut; with a deletion in the CR1 domain), or with the transforming Ha-ras (EJ) gene. The growth of all these cell lines was inhibited by milimolar concentrations of sodium butyrate (NaBut). However, whereas the NRK cells as well as the NRK-E1Amut and NRK-ras cells were arrested in the G1 phase of the cell cycle, the NRK-E1A cells progressively accumulated in the G2 phase, suggesting that the E1A gene expression caused a “leaky” inhibition of G1 phase progression. The expression of late cell cycle-related genes cdc2 and PCNA (proliferating cell nuclear antigen) was not affected by NaBut in the NRK-E1A cells while it was totally suppressed in the other NRK-derived cell lines.
G proteins and regulation of adenylyl cyclase
Authors: Gilman Alfred G.
Published: February 2005

The function and structures of G proteins and their role in the regulation of adenylyl cyclase is reviewed.
A proper transmembrane Ca2+ gradient is essential for the stimulation of adenylate cyclase activity by stimulatory GTP-binding protein
Authors: Huang Youguo , Fan Gaofeng , Yang Fuyu
Published: February 2005

Stimulatory GTP-binding Protein (Gs) and adenylate cyclase prepared from bovine brain cortices were co-reconstituted into asolectin vesicles with or without 1000-fold transmembrane Ca2+ gradient. The results showed that both basal activity and Gs-stimulated activity of adenylate cyclase were highest in proteoliposomes with a transmembrane Ca2+ gradient similar to physiological condition (1 μM Ca2+ outside and 1 mM Ca2+ inside) and lowest when the transmembrane Ca2+ gradient was in the inverse direction. Such a difference could be diminished following dissipation of the transmembrane Ca2+ gradient by A23187. Comparable conformational changes of Gs in proteoliposomes were also observed when Gs was labeled with the fluorescence probe, acrylodan. These results may indicate that a proper transmembrane Ca2+ gradient is essential not only for higher adenylate cyclase activity but also for its stimulation by Gs.
Trafficking of glucose transporters-signals and mechanisms
Authors: Baldwin Stephen A. , Barros L. Felipe , Griffiths Mark
Published: February 2005

The uptake of glucose into mammalian cells, catalysed by members of the GLUT family of glucose transporters, is regulated by a variety of hormones, growth factors and other agents. In adipocytes, skeletal muscle and heart the principal regulator is the hormone insulin, which rapidly stimulates glucose uptake by bringing about the translocation of the GLUT4 glucose transporter isoform from an intracellular vesicular compartment to the cell surface. Recent studies have implicated the C-terminal hydrophilic region of this protein as being primarily responsible for its insulin-regulated trafficking. In an attempt to identify the protein machinery involved in this trafficking, we have used glutathione S-transferase fusion proteins bearing hydrophilic domains of various GLUT transporters in affinity purification experiments on detergent-solubilized extracts of 3T3-L1 adipocyte intracellular membranes. The C-terminal region of GLUT4 was found specifically to bind a number of polypeptides in these extracts, which are therefore candidates for components of the trafficking machinery. Although these proteins did not bind to the corresponding region of the more widely-distributed GLUT1 glucose transporter isoform, regulation of this transporter also appears to be of physiological importance in some cell types. To study such regulation we have used as a model system the interleukin-3 (IL-3)-dependent haemopoietic cell line IC.DP. These cells express a temperature-sensitive mutane of the v-abl tyrosine kinase, whose activation at the permissive temperature permits cell survival in the absence of IL-3 by suppression of apoptosis, although the growth factor is still required for proliferation. Both IL-3 and activation of the kinase were found to stimulate glucose transport by promoting the translocation of GLUT1 to the cell surface. Moreover, inhibition of glucose uptake by addition of transport inhibitors markedly increased the rate of apoptosis, an effect which could be reversed by the provision of alternative energy sources. These observations suggest that the trafficking of GLUT1, regulated by growth factors or oncogenes, may play an important role in the suppression of apoptosis in haemopoietic cells.
Computable processes and bisimulation equivalence
Authors: Ponse Alban
Published: February 2005

A process is called
computable
if it can be modelled by a transition system that has a recursive structure—implying finite branching. The equivalence relation between transition systems considered is strong bisimulation equivalence. The transition systems studied in this paper can be associated to processes specified in common specification languages such as CCS, LOTOS, ACP and PSF. As a means for defining transition systems up to bisimulation equivalence, the specification language
μ
CRL is used. Two simple fragments of,
μ
CRL are singled out, yielding universal expressivity with respect to recursive and primitive recursive transition systems. For both these domains the following properties are classified in the arithmetical hierarchy:
bisimilarity, perpetuity
(both ∏
1
0
),
regularity
(having a bisimilar, finite representation, Σ
2
0
),
acyclic regularity
(Σ
1
0
), and
deadlock freedom
(distinguishing deadlock from successful termination, ∏
1
0
). Finally, it is shown that in the domain of primitive recursive transition systems over a fixed, finite label set, a genuine hierarchy in bisimilarity can be defined by the complexity of the witnessing relations, which extends r.e. bisimilarity. Hence, primitive recursive transition systems already form an interesting class.
Synthetic modular systems – reverse engineering of signal transduction
Authors: Pawson Tony , Linding Rune
Published: February 2005

During the last decades, biology has decomposed cellular systems into genetic, functional and molecular networks. It has become evident that these networks consist of components with specific functions (e.g., proteins and genes). This has generated a considerable amount of knowledge and hypotheses concerning cellular organization. The idea discussed here is to test the extent of this knowledge by reconstructing, or reverse engineering, new synthetic biological systems from known components. We will discuss how integration of computational methods with proteomics and engineering concepts might lead us to a deeper and more abstract understanding of signal transduction systems. Designing and successfully introducing synthetic proteins into cellular pathways would provide us with a powerful research tool with many applications, such as development of biosensors, protein drugs and rewiring of biological pathways.
Palaeobotanical evidence for warm summers in the East Siberian Arctic during the last cold stage
Authors: Kienast Frank , Schirrmeister Lutz , Siegert Christine , Tarasov Pavel
Published: February 2005

Plant macrofossils from the “Mamontovy Khayata” permafrost sequence (71°60′N, 129°25′E) on the Bykovsky Peninsula reflect climate and plant biodiversity in west Beringia during the last cold stage. 70 AMS and 20 conventional14C dates suggest sediment accumulation between about 60,000 and 750014C yr B.P. The plant remains prove that during the last cold-stage arctic species (Minuartia arctica,Drabaspp.,Kobresia myosuroides) coexisted with aquatic (Potamogeton vaginatus,Callitriche hermaphroditica), littoral (Ranunculus reptans,Rumex maritimus), meadow (Hordeum brevisubulatum,Puccinellia tenuiflora) and steppe taxa (Alyssum obovatum,Silene repens,Koeleria cristata,Linum perenne). The reconstructed vegetation composition is similar to modern vegetation mosaics in central and northeast Yakutian relict steppe areas. Thus, productive meadow and steppe communities played an important role in the Siberian Arctic vegetation during the late Pleistocene and could have served as food resource for large populations of herbivores. The floristic composition reflects an extremely continental, arid climate with winters colder and summers distinctly warmer than at present. Holocene macrofossil assemblages indicate a successive paludification possibly connected with marine transgression, increased oceanic influence and atmospheric humidity. Although some steppe taxa were still present in the early Holocene, they disappeared completely before ∼290014C yr B.P.
MATERNAL, NEONATAL AND COMMUNITY FACTORS INFLUENCING NEONATAL MORTALITY IN BRAZIL
Authors: JORGE MACHADO CARLA , HILL KENNETH
Published: February 2005

Child mortality (the mortality of children less than five years old) declined considerably in the developing world in the 1990s, but infant mortality declined less. The reductions in neonatal mortality were not impressive and, as a consequence, there is an increasing percentage of infant deaths in the neonatal period. Any further reduction in child mortality, therefore, requires an understanding of the determinants of neonatal mortality. 209,628 birth and 2581 neonatal death records for the 1998 birth cohort from the city of São Paulo, Brazil, were probabilistically matched. Data were from SINASC and SIM, Information Systems on Live Births and Deaths of Brazil. Logistic regression was used to find the association between neonatal mortality and the following risk factors: birth weight, gestational age, Apgar scores at 1 and 5 minutes, delivery mode, plurality, sex, maternal education, maternal age, number of prior losses, prenatal care, race, parity and community development. Infants of older mothers were less likely to die in the neonatal period. Caesarean delivery was not found to be associated with neonatal mortality. Low birth weight, pre-term birth and low Apgar scores were associated with neonatal death. Having a mother who lives in the highest developed community decreased the odds of neonatal death, suggesting that factors not measured in this study are behind such association. This result may also indicate that other factors over and above biological and more proximate factors could affect neonatal death.
What the People Want: State Planning and Political Participation in Peronist Argentina, 1946–1955
Authors: ELENA EDUARDO
Published: February 2005

This study examines an episode in the social history of state planning by focusing on the 1951 Peronist letter writing campaign. Perón's request for popular suggestions to the Second Five-Year Plan was met with enthusiasm from men and women across Argentina. As with other cases of state planning in the postwar world, the Peronist model of planned progress inspired many popular sector individuals and organisations, in part by offering them an intimate mode of political participation within an increasingly restrictive order. This appeal cannot be attributed to Peronist mass politics alone; rather, the regime's ideal of macro-level national planning also reinforced pre-existing practices of social activism in Argentine local communities.
Freedom, human and divine
Authors: MAWSON T. J.
Published: February 2005

In this paper I seek to show how God's freedom is not reduced or His power diminished by His inability to be less than perfectly good even though ours would be. That ours would be explains why it might prima facie appear to us that there is a ‘conceptual tension’ between some of the claims of traditional theism and reveals some interesting (well, to me anyway) differences between human freedom and divine freedom.
The meaning of mystical ‘darkness’
Authors: KÜGLER PETER
Published: February 2005

Arguments by W. T. Stace and C. J. Insole show that metaphorical descriptions of God presuppose literal descriptions of God. This poses a problem for the metaphor of darkness which has often been used, for instance by Pseudo-Dionysius, in the context of negative theology and apophatic mysticism. Three strategies of dealing with the problem are discussed in this article. The negative, apophatic approach can be seen either as subverting itself, or as being restricted to certain properties, or as resting on a self-excluding principle. Whereas the first two strategies have their difficulties, self-exclusion is linguistically founded and adequate to the purposes of negative theology.
Submerging or Clinging On Again? József Antall, Father and Son, in Hungary after 1956
Authors: RAINE JÁNOS M.
Published: February 2005

The aim of this case study of the two Antalls, father and son (the latter became the first Hungarian prime minister after the free elections in 1990) is to present and analyse the period that coincided with the post-1956 development of the Kádár system. Its apparent success, efficiency and partial, surrogate, legitimacy has often been explained by the so-called ‘compromise’ of the Kádárist leadership with Hungarian society after 1956, particularly the ‘old intelligentsia’ or ‘old middle classes’. In fact, while there was an obvious continuity in institutions and ideology between the classic Stalinist regime and that of Kádár, the societal and political practice of the system gradually changed. The Antalls were representative of the inter-war upper middle class (the father) and the participants in the 1956 revolution (the son). Discrimination according to their social background, prevalent in the early 1950s, diminished at the turn of the 1960s, so that someone descended from the former Christian middle class, like the younger József Antall, could be recruited into the intelligentsia.
Comment on Kershaw
Authors: SMITH STEVE
Published: February 2005

In his wide-ranging and thought-provoking analysis of war and political violence in twentieth-century Europe, Ian Kershaw contrasts the immense violence wrought in Europe in the first half of the century with its relatively pacific history in the second half. Resisting the temptation to think of the violence of the first half of the century as a dysfunctional interruption to an underlying tale of economic, social and political progress, the author poses three astute questions concerning: (i) the causes of state-sponsored violence; (ii) the reasons why some states presided over low levels of violence while others presided over levels that ‘soared into the stratosphere’; and (iii) whether there was something qualitatively new – or ‘modern’ – about that violence. Kershaw describes his piece as ‘thinking aloud’ and I read it in that spirit. I find myself in broad agreement with what he has to say, although we probably disagree over matters of emphasis – for example in respect of the significance of violence perpetrated by European states in their colonies, or the propensity for violence of liberal democratic states. I suspect that there is more principled disagreement about the salience of ‘ideology’ in fomenting the mass violence of the twentieth century. I have organised my responses according to the three stages of his argument; I end by considering the nature of ‘peace’ in Europe in the second half of the century and by offering a few reflections on the conceptualisation of political violence.
Morphology of basaltic lava channels during the Mt. Etna September 2004 eruption from airborne laser altimeter data
Authors: Mazzarini Francesco , Pareschi Maria Teresa , Favalli Massimiliano , Isola Ilaria , Tarquini Simone , Boschi Enzo
Published: February 2005

The morphological features of active lava channels acquired over Mt. Etna by means of airborne laser altimeter data are presented. The data were acquired on 16th September 2004, using an Optech ALTM 3033 laser altimeter. The flight height was about 2000 m above ground. During the flight, the lava, erupted from the eastern part of the Mt. Etna summit area, flowed into the Valle del Bove. The measured morphologic features are: channel width (Wc), flow width (Wf), levee height (Hl), flow thickness (Tf), and channel depth (Dc). The main lava flow shows a well‐developed channel with levees. The average measured values for the morphologic features of this flow are: Wc = 16 m, Wf = 52 m, Hl = 7 m, Tf = 5 m and Dc = 2 m. The Wc parameter shows linear increase from about 7 m near the vent up to about 25 m close to the front (∼1600 m in length).
A search for142Nd evidence of primordial mantle heterogeneities in plume basalts
Authors: Boyet Maud , Garcia Michael O. , Pik Raphaël , Albarède Francis
Published: February 2005

In order to assess whether material differentiated shortly after terrestrial accretion is still present in the deep mantle, we investigated hot spot basalts for142Nd/144Nd anomalies that could attest for the presence of live146Sm (T1/2= 103 My) at the time the mantle source of these basalts formed. We analyzed high3He/4He basalts from Loihi and Ethiopia and normal3He/4He basalts from Iceland. Although the143Nd/144Nd ratios of these basalts reflect a source with long‐term LREE (light rare earth elements) depletion, no resolvable142Nd anomalies were detected. Taking the analytical uncertainties (10–20 ppm) into account, however, the present results do not rule out the possibility that a large proportion of material fractionated very early in the Earth's history may still be hidden in the deep mantle.
Energy deposition by Alfvén waves into the dayside auroral oval: Cluster and FAST observations
Authors: Chaston C. C. , Peticolas L. M. , Carlson C. W. , McFadden J. P. , Mozer F. , Wilber M. , Parks G. K. , Hull A. , Ergun R. E. , Strangeway R. J. , Andre M. , Khotyaintsev Y. , Goldstein M. L. , Acuña M. , Lund E. J. , Reme H. , Dandouras I. , Fazakerley A. N. , Balogh A.
Published: February 2005

We report in situ observations from the Cluster and FAST spacecraft showing the deposition of energy into the auroral ionosphere from broadband ULF waves in the cusp and low‐latitude boundary layer. A comparison of the wave Poynting flux with particle energy and flux at both satellites indicates that energy transfer from the broadband waves to the plasma occurs through field‐aligned electron acceleration, transverse ion acceleration, and Joule heating. These processes are shown to result in precipitating electron fluxes sufficient to drive bright aurora and cause outflows of energized electrons and O+ ions from the ionosphere into the low‐latitude boundary layer. By solving an eigenmode equation for Alfvén waves in the observed plasma environment, it is shown that the broadband waves observed at Cluster and FAST are dispersive Alfvén waves. It is demonstrated that these waves have wavelengths perpendicular to the geomagnetic field extending from significant fractions of an L shell down to ion gyroradii and electron inertial lengths and wave frequencies in the plasma frame from 1 mHz up to 50 mHz. These waves are shown to have wavelengths along the geomagnetic field of the order of the field line length between the ionosphere and the equatorial plane and become field line resonances (FLRs) when on closed field lines. It is shown that the inclusion of nonlinear and/or nonlocal kinetic effects is required in the description of these waves to account for accelerated particles observed. On the basis of the wave polarization and spectral properties observed from Cluster and FAST it is speculated that these waves are generated through the mode conversion of surface Alfvén waves driven by tailward flows in the low‐latitude boundary layer.
Plasma sheet and (nonstorm) ring current formation from solar and polar wind sources
Authors: Moore T. E. , Fok M.‐C. , Chandler M. O. , Chappell C. R. , Christon S. P. , Delcourt D. C. , Fedder J. , Huddleston M. , Liemohn M. , Peterson W. K. , Slinker S.
Published: February 2005

We consider the formation of the plasma sheet and geosynchronous region (nonstorm) ring current in the framework of collisionless test particle motions in three‐dimensional magnetospheric fields obtained from self‐consistent MHD simulations. Simulation results are compared with observations of the near‐Earth plasma sheet from the Polar spacecraft during 2001 and 2002. Many particles were initiated in two regions representative of the solar wind source upstream of the bow shock and the polar wind source outside the plasmasphere, both of which are dominated by protons (H+). Proton trajectories are run until they precipitate into the atmosphere, escape from the simulation space, or become stably trapped. These calculations produce a database of proton characteristics in each 1 RE3 volume element of the magnetosphere and yield velocity distributions as well as bulk plasma properties. We report results reflecting steady growth phase conditions after 45 min of southward interplanetary field, BZ = −5 nT (BY = 0), and for conditions resulting after 2 hours of northward BZ = +5 nT. The results for simulated velocity distributions are consistent with the Polar soundings of the current sheet from lobe to lobe and with AMPTE/CCE observations of (nonstorm) ring current region protons. The simulations help us identify the differentiation between solar and polar wind H+ ions in observations. The weak NBZ ring current‐like pressure is primarily polar wind protons, while the moderately active SBZ ring current‐like pressure is primarily solar wind protons. The solar and polar wind contributions to the SBZ ring current are comparable in density, but the solar protons have a higher average energy. For SBZ, solar wind protons enter the nonstorm ring current region primarily via the dawn flank and to a lesser degree via the midnight plasma sheet. For NBZ, solar wind protons enter the ring current‐like region via the cusp and flanks. Polar wind protons enter the nonstorm ring current through the midnight plasma sheet in both cases. Solar and ionospheric plasmas thus take different transport paths to the geosynchronous (nonstorm) ring current region and may thus be expected to respond differently to substorm dynamics of the magnetotail.
The polar mesospheric cloud mass in the Arctic summer
Authors: Stevens Michael H. , Englert Christoph R. , DeLand Matthew T. , Hervig Mark
Published: February 2005

We infer the polar mesospheric cloud (PMC) mass throughout the Arctic summer using results from two sets of satellite observations and a microphysical model. Solar backscatter ultraviolet (SBUV) PMC observations in July 1999 indicate a burst of activity persisting for ∼8 days after a space shuttle launch and averaging 262 ± 52 t near 4.7 local time. This mass is consistent with the propellant mass available from the shuttle's main engines and accounts for 22% of the total SBUV PMC mass over the season between 65° and 75°N. This is the first evidence that PMCs formed by space shuttle water exhaust can contribute significantly to both the number of observed PMCs and the total PMC mass in a season. In another approach, 11 years of observations by the Halogen Occultation Experiment (HALOE) indicate that on average 90 ± 12 t of water ice is present near local midnight between 65° and 75°N. Using simultaneous HALOE water vapor observations, we find that a one‐dimensional microphysical model reproduces the start and end of the PMC season but overpredicts the ice mass by about a factor of 1.8 when compared with the observations. This overprediction is within the time‐dependent variability of ice formation and the uncertainties of temperature, water vapor, and vertical winds used to initialize the model.