bluuebunny/crossref_metadata_2025 huggingface dataset:
Carrier trapping and scattering in amorphous organic hole transporter
Authors: Tsung K. K. , So S. K.
Published: March 2008

The effects of dopants on the hole transporting properties of N,N′-diphenyl-N,N′-bis(1-naphthyl)(1,1’-biphenyl)-4,4’diamine (NPB) have been studied by time of flight. Five dopants: copper phthalocyanine (CuPc), 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyrle)-4H-pyran (DCM1), 4-dicyanomethylene-2-methyl-6-[2-(2,3,6,7-tetra-hydro-1H,5H-benzo[ij] quinolizin-8-yl)vinyl]-4H-pyran (DCM2), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) are used in this study. The dopant molecules behave like hole traps or scatterers. Their detailed behaviors are determined by their highest occupied molecular orbital relative to that of NPB. Generally, traps are found to induce significant reduction in hole mobility while there is a slight reduction for scattering. Two different underlying charge transport mechanisms are proposed.
Fluorination-induced magnetism in boron nitride nanotubes from ab initio calculations
Authors: Li Feng , Zhu Zhonghua , Yao Xiangdong , Lu Gaoqing , Zhao Mingwen , Xia Yueyuan , Chen Ying
Published: March 2008

Ab initio calculations were conducted to investigate the electronic structures and magnetic properties of fluorinated boron nitride nanotube (F-BNNT). It was found that the chemisorption of F atoms on the B atoms of BNNT can induce spontaneous magnetization, whereas no magnetism can be produced when the B and N atoms are equally fluorinated. This provides a different approach to tune the magnetic properties of BNNTs as well as a synthetic route toward metal-free magnetic materials.
NMR chemical shifts of molecules encapsulated in single walled carbon nanotubes
Authors: Besley Nicholas A. , Noble Adam
Published: March 2008

We present density functional theory calculations of the nuclear magnetic resonance spectroscopy of molecules encapsulated within single walled carbon nanotubes. Ring currents in the nanotube induce shifts in the chemical shift of the nuclei comprising the encapsulated molecule. These changes in the chemical shifts are shown to have characteristic dependence on the chirality of the surrounding nanotubes.
Rectifying current-voltage characteristics of BiFeO3∕Nb-doped SrTiO3 heterojunction
Authors: Yang H. , Luo H. M. , Wang H. , Usov I. O. , Suvorova N. A. , Jain M. , Feldmann D. M. , Dowden P. C. , DePaula R. F. , Jia Q. X.
Published: March 2008

Epitaxial c-axis oriented BiFeO3 (BFO) thin films were deposited on (001) Nb-doped SrTiO3 (Nb-STO) substrates by pulsed laser deposition. Introducing Bi vacancies caused the BFO thin film to evolve to a p-type semiconductor and formed a p-n heterojunction with an n-type semiconductor Nb-STO. The current density versus voltage (J-V) and capacitance versus voltage (C-V) characteristics of the heterojunction were investigated. A typical rectifying J-V effect was observed with a large rectifying ratio of 5×104. Reverse C-V characteristics exhibited a linear 1∕C2 versus V plot, from which a built-in potential of 0.6V was deduced. The results show a potential application of BFO/Nb-STO heterojunction for oxide electronics.
Optimal electrode shape and size of doubly rotated quartz plate thickness mode piezoelectric resonators
Authors: Yang Zengtao , Yang Jiashi , Hu Yuantai
Published: March 2008

Using the Stevens–Tiersten equation for slowly varying thickness modes in doubly rotated quartz plate piezoelectric resonators, we determine optimal electrode shape and size for these resonators. The electrodes obtained are optimal in that they satisfy Bechmann’s number in every direction.
Current-induced persistent magnetization in a relaxorlike manganite
Authors: Sakai H. , Tokura Y.
Published: March 2008

A single crystal of 7% Fe-doped (La0.7Pr0.3)0.65Ca0.35MnO3 shows up as a typical relaxor ferromagnet, where ferromagnetic metallic (FM) and charge-orbital-ordered insulating clusters coexist with controllable volume fraction by external stimuli. There, the persistent FM state can be produced by an electric-current excitation as the filamentary region, the magnetization in which is increased by ∼0.4μB per Mn. A clear distinction from the current heating effect in a magnetic field, which conversely leads to a decrease in FM fraction, enables us to bidirectionally switch both the magnetization and resistance by applying the voltages with different magnitudes.
Demonstration of a refractometric sensor based on optical microfiber coil resonator
Authors: Xu Fei , Brambilla Gilberto
Published: March 2008

We experimentally demonstrated a refractometric sensor based on a coated optical microfiber coil resonator. It is robust, compact, and comprises an intrinsic fluidic channel. A sensitivity of about 40nm/RIU (refractive index unit) has been measured, in agreement with predictions.
Nonlinear long-period gratings in As2Se3 chalcogenide fiber for all-optical switching
Authors: Nguyen H. C. , Yeom D.-I. , Mägi E. C. , Fu L. B. , Kuhlmey B. T. , Martijn de Sterke C. , Eggleton B. J.
Published: March 2008

We present experimental demonstration of all-optical switching using long-period gratings (LPGs) in highly nonlinear As2Se3 chalcogenide fiber. We use a 135mm grating which is generated using acoustic waves. We characterize the nonlinear pulse propagation through the LPG using picosecond pulses tuned to different wavelengths with respect to the grating resonance. We compare the results with numerical simulations and observe switching at pulse peak powers around 50W, two orders of magnitude smaller than previously demonstrated in silica.
Quantized level transitions and modification in InGaN∕GaN multiple quantum wells
Authors: Li Jinchai , Li Shuping , Kang Junyong
Published: March 2008

A detailed study of emission mechanism is performed in undoped and Mg-doped InGaN∕GaN multiple quantum wells (MQWs) by means of injection-current- and temperature-dependent electroluminescence measurements. Two emission peaks corresponding to the recombination in InGaN quantum well are observed at high injection-current level in both MQWs. According to the emission behaviors with increasing injection current and decreasing temperature, in conjunction with the numerical calculations, these two peaks are tentatively assigned to be the interband transitions from the first quantized electron level to the first and second quantized heavy-hole levels (1e-1hh and 1e-2hh), respectively. Moreover, the energy separation of the interband transitions is reduced from 200to130meV by Mg dopant, which indicates that the quantized levels have been modified as a result of weakening of the polarization field.
Mechanical characterization of individual Ni∕Au coated microsize polymer particles
Authors: Dou Guangbin , Whalley David C. , Liu Changqing
Published: March 2008

We report on a mechanical characterization technique for individual Ni∕Au coated microsize polymer particles. This technique allows a clearer understanding of the effects of load force and rate on the particle deformation. This has been achieved through measurements of the deformation against force using a specially configured nanoindenter machine, where the “indenters,” instead of being pointed, had a flat tip of 20μm in diameter. The results show that the particle deformation process is nonlinear and that the force/deformation at which particle crushing occurs is affected by the load rate. The technique could be used to design/manufacture more effective conductive particles.
Efficient light coupling from integrated single-mode waveguides to supercollimating photonic crystals on silicon-on-insulator platforms
Authors: Vynck K. , Centeno E. , Le Vassor d’Yerville M. , Cassagne D.
Published: March 2008

We propose a practical and efficient solution for the coupling of light from integrated single-mode waveguides to supercollimating planar photonic crystals (PhCs) on conventional silicon-on-insulator platforms. The device consists of a rib waveguide, designed to sustain spatially extended single modes and matched to a supercollimating PhC, which has been truncated at its boundary to improve impedance matching between the two photonic components. Three-dimensional simulations show transmission efficiencies up to 96% and reflections below 0.2% at wavelengths close to 1.55μm. This approach constitutes a significant step toward the integration of supercollimating structures on photonic chips.
High-power single mode (>1W) continuous wave operation of longitudinal photonic band crystal lasers with a narrow vertical beam divergence
Authors: Novikov I. I. , Gordeev N. Yu. , Shernyakov Yu. M. , Kiselev Yu. Yu. , Maximov M. V. , Kop’ev P. S. , Sharon A. , Duboc R. , Arbiv D. B. , Ben-Ami U. , Shchukin V. A. , Ledentsov N. N.
Published: March 2008

We report on 980nm InGaAs∕AlGaAs lasers with a broad waveguide based on a longitudinal photonic band crystal concept. The beam divergence measured as full width at half maximum was as narrow as <5° (vertical). Broad area 100μm multimode devices demonstrated >15W pulsed operation as limited by the current source. Significantly increased modal spot size enabled stable single lateral mode operation in broad ridge 10μm stripes. Maximum continuous wave power in single mode regime of 1.3W for 10μm wide stripe lasers was obtained, being limited by the catastrophic degradation of the unpassivated laser facets.
Loss of phosphorus and nitrogen in runoff and subsurface drainage from high and low input pastures grazed by sheep in southern Australia
Authors: Melland A. R. , Mc Caskill M. R. , White R. E. , Chapman D. F.
Published: March 2008

High rates of fertiliser applied to boost pasture growth in the southern Australian sheep industry may lead to eutrophication of waterways and groundwater degradation. A field study was used to investigate whether higher fertiliser and stocking rates would increase nutrient loss in runoff and subsurface flow from pastures. Phosphorus (P) and nitrogen (N) concentrations in surface and subsurface flow were measured from 1998–2000 in four 0.5-ha hillslope plots. Surface flow volume was measured directly and subsurface water flux was estimated using soil moisture data and a water balance model. A simulated rainfall study was also conducted using 0.64-m2 plots. The treatments represented were: a low-P set-stocked sown pasture (SS low P), a high-P set-stocked sown pasture (SS high P), a high-P sown pasture in a 4-paddock rotation (RG 4-pdk), and an unsown set-stocked pasture (Low P volunteer).
No runoff from the hillslope occurred in 1999, while the volume of runoff in 1998 and 2000 varied from 0.1 to 68 mm/year across the 4 hillslope plots. More P was lost via surface runoff (up to 0.25 kg P/ha.year) than subsurface flow (up to 0.027 kg P/ha.year). However, N loads were greater in subsurface flows (3.2–10.6 kg N/ha.year) than surface runoff (0.04–2.74 kg N/ha.year). Phosphorus concentrations were higher in runoff from the high P treatments (0.34–0.83 mg P/L) than the set-stocked low P treatment (0.19–0.22 mg P/L). Higher TP concentrations in runoff from the high P treatments were associated with greater labile P contents in the soil, dung, and herbage. However, the volume of runoff, rather than the pasture treatment, was the primary determinant of nutrient loss. Avoiding high nutrient inputs in seasonally waterlogged areas, sowing perennial pastures, and minimising stock camping helps minimise P losses to waterways and N losses to groundwater.
Protein phosphatase 2A controls the activity of histone deacetylase 7 during T cell apoptosis and angiogenesis
Authors: Martin Maud , Potente Michael , Janssens Veerle , Vertommen Didier , Twizere Jean-Claude , Rider Mark H. , Goris Jozef , Dimmeler Stefanie , Kettmann Richard , Dequiedt Franck
Published: March 2008

Class IIa histone deacetylases (HDACs) act as key transcriptional regulators in several important developmental programs. Their activities are controlled via phosphorylation-dependent nucleocytoplasmic shuttling. Phosphorylation of conserved serine residues triggers association with 14-3-3 proteins and cytoplasmic relocalization of class IIa HDACs, which leads to the derepression of their target genes. Although a lot of effort has been made toward the identification of the inactivating kinases that phosphorylate class IIa HDAC 14-3-3 motifs, the existence of an antagonistic protein phosphatase remains elusive. Here we identify PP2A as a phosphatase responsible for dephosphorylating the 14-3-3 binding sites in class IIa HDACs. Interestingly, dephosphorylation of class IIa HDACs by PP2A is prevented by competitive association of 14-3-3 proteins. Using both okadaic acid treatment and RNA interference, we demonstrate that PP2A constitutively dephosphorylates the class IIa member HDAC7 to control its biological functions as a regulator of T cell apoptosis and endothelial cell functions. This study unravels a dynamic interplay among 14-3-3s, protein kinases, and PP2A and provides a model for the regulation of class IIa HDACs.
Temperature-induced switch to the pathogenic yeast form of
Histoplasma capsulatum
requires Ryp1, a conserved transcriptional regulator
Authors: Nguyen Van Q. , Sil Anita
Published: March 2008

Histoplasma capsulatum
, a fungal pathogen of humans, switches from a filamentous spore-forming mold in the soil to a pathogenic budding-yeast form in the human host. This morphologic switch, which is exhibited by
H. capsulatum
and a group of evolutionarily related fungal pathogens, is regulated by temperature. Using insertional mutagenesis, we identified a gene,
RYP1
(required for yeast phase growth), which is required for yeast-form growth at 37°C.
ryp1
mutants are constitutively filamentous irrespective of temperature. Ryp1 is a member of a family of fungal proteins that includes Wor1, a master transcriptional regulator of the white-opaque transition required for mating in
Candida albicans
. Ryp1 associates with its own upstream regulatory region, consistent with a direct role in transcriptional control, and both the protein and its transcript accumulate to high levels in wild-type yeast-phase cells. Microarray analysis demonstrated that Ryp1 is required for the expression of the vast majority of yeast-specific genes, including two genes linked to virulence. Thus, Ryp1 appears to be a critical transcriptional regulator of a temperature-regulated morphologic switch in
H. capsulatum
.
Reassessing a sparse energetic network within a single protein domain
Authors: Chi Celestine N. , Elfström Lisa , Shi Yao , Snäll Tord , Engström Åke , Jemth Per
Published: March 2008

Understanding the molecular principles that govern allosteric communication is an important goal in protein science. One way allostery could be transmitted is via sparse energetic networks of residues, and one such evolutionary conserved network was identified in the PDZ domain family of proteins by multiple sequence alignment [Lockless SW, Ranganathan R (1999)
Science
286:295–299]. We have reassessed the energetic coupling of these residues by double mutant cycles together with ligand binding and stability experiments and found that coupling is not a special property of the coevolved network of residues in PDZ domains. The observed coupling for ligand binding is better explained by a distance relationship, where residues close in space are more likely to couple than distal residues. Our study demonstrates that statistical coupling from sequence analysis is not necessarily a reporter of energetic coupling and allostery.
X-inactivation in female human embryonic stem cells is in a nonrandom pattern and prone to epigenetic alterations
Authors: Shen Yin , Matsuno Youko , Fouse Shaun D. , Rao Nagesh , Root Sierra , Xu Renhe , Pellegrini Matteo , Riggs Arthur D. , Fan Guoping
Published: March 2008

X chromosome inactivation (XCI) is an essential mechanism for dosage compensation of X-linked genes in female cells. We report that subcultures from lines of female human embryonic stem cells (hESCs) exhibit variation (0–100%) for XCI markers, including
XIST
RNA expression and enrichment of histone H3 lysine 27 trimethylation (H3K27me3) on the inactive X chromosome (Xi). Surprisingly, regardless of the presence or absence of XCI markers in different cultures, all female hESCs we examined (H7, H9, and HSF6 cells) exhibit a monoallelic expression pattern for a majority of X-linked genes. Our results suggest that these established female hESCs have already completed XCI during the process of derivation and/or propagation, and the XCI pattern of lines we investigated is already not random. Moreover,
XIST
gene expression in subsets of cultured female hESCs is unstable and subject to stable epigenetic silencing by DNA methylation. In the absence of
XIST
expression, ≈12% of X-linked promoter CpG islands become hypomethylated and a portion of X-linked alleles on the Xi are reactivated. Because alterations in dosage compensation of X-linked genes could impair somatic cell function, we propose that XCI status should be routinely checked in subcultures of female hESCs, with cultures displaying XCI markers better suited for use in regenerative medicine.
X-chromosome inactivation and epigenetic fluidity in human embryonic stem cells
Authors: Silva Susana S. , Rowntree Rebecca K. , Mekhoubad Shila , Lee Jeannie T.
Published: March 2008

With the potential to give rise to all somatic cell types, human embryonic stem cells (hESC) have generated enormous interest as agents of cell replacement therapy. One potential limitation is their safety
in vivo
. Although several studies have focused on concerns over genomic stability
ex vivo
, few have analyzed epigenetic stability. Here, we use tools of the epigenetic phenomenon, X-chromosome inactivation (XCI), to investigate their epigenetic properties. Among 11 distinct hESC lines, we find a high degree of variability. We show that, like mouse ESC, hESC in principle have the capacity to recapitulate XCI when induced to differentiate in culture (class I lines). However, this capacity is seen in few hESC isolates. Many hESC lines have already undergone XCI (class II and III). Unexpectedly, there is a tendency to lose XIST RNA expression during culture (class III). Despite losing H3-K27 trimethylation, the inactive X of class III lines remains transcriptionally suppressed, as indicated by Cot-1 RNA exclusion. We conclude that hESC lines are subject to dynamic epigenetic reprogramming
ex vivo
. Given that XCI and cell differentiation are tightly linked, we consider implications for hESC pluripotency and differentiation potential.
Inositol trisphosphate 3-kinase B (InsP3KB) as a physiological modulator of myelopoiesis
Authors: Jia Yonghui , Loison Fabien , Hattori Hidenori , Li Yitang , Erneux Christophe , Park Shin-Young , Gao Chong , Chai Li , Silberstein Leslie E. , Schurmans Stephane , Luo Hongbo R.
Published: March 2008

Inositol trisphosphate 3-kinase B (InsP3KB) belongs to a family of kinases that convert inositol 1,4,5-trisphosphate (Ins(1,4,5)P3 or IP3) to inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P4). Previous studies have shown that disruption of InsP3KB leads to impaired T cell and B cell development as well as hyperactivation of neutrophils. Here, we demonstrate that InsP3KB is also a physiological modulator of myelopoiesis. The InsP3KB gene is expressed in all hematopoietic stem/progenitor cell populations. In InsP3KB null mice, the bone marrow granulocyte monocyte progenitor (GMP) population was expanded, and GMP cells proliferated significantly faster. Consequently, neutrophil production in the bone marrow was enhanced, and the peripheral blood neutrophil count was also substantially elevated in these mice. These effects might be due to enhancement of PtdIns(3,4,5)P3/Akt signaling in the InsP3KB null cells. Phosphorylation of cell cycle-inhibitory protein p21
cip1
, one of the downstream targets of Akt, was augmented, which can lead to the suppression of the cell cycle-inhibitory effect of p21.
Maintenance of the plasma cell pool is independent of memory B cells
Authors: Ahuja Anupama , Anderson Shannon M. , Khalil Ashraf , Shlomchik Mark J.
Published: March 2008

Humoral memory to an antigen (Ag) is maintained for several decades in the form of memory B cells and serum Ab. In fact, plasma cells (PCs) that secrete Ab are known to be long-lived and could be solely responsible for maintaining the long-lived Ab titers. Alternatively, it has been proposed that the PC compartment is maintained for long periods by the differentiation of memory cells into long-lived PCs as a result of nonspecific stimulation. This model predicts accelerated decay of PC numbers in the absence of memory cells for the same Ag. To address this prediction, we have developed a mouse model system that combined the ability to deplete B cells with the ability to detect Ag-specific memory and PCs. After establishing an immune response, we depleted Ag-specific memory B cells with an anti-hCD20 mAb and determined the effect on the PC compartment over 16 weeks. Using a combination of surface markers, we demonstrated that memory B cells remained depleted over the course of the experiment. However, despite this absence of memory cells for an extended duration, PC numbers in spleen and bone marrow did not decline, which indicates that the PC compartment does not require a significant contribution from memory B cells for its maintenance and instead that PCs are sufficiently long-lived to maintain Ab titers over a long period without renewal. This observation settles an important controversy in B cell biology and has implications for the design of vaccines and for B cell depletion therapy in patients.
The “complex first” paradox
Authors: Werning Markus
Published: March 2008

The Complex-First Paradox regards the semantics of nouns and consists of a set of together incompatible, but individually well confirmed propositions about the evolution and development of language, the semantics of word classes and the cortical realization of word meaning. Theoretical and empirical considerations support the view that the concepts expressed by concrete nouns are more complex and their neural realizations more widely distributed in cortex than those expressed by other word classes. For a cortically implemented syntax–semantics interface, the more widely distributed a concept’s neural realization is, the more effort it takes to establish a link between the concept and its expression. If one assumes the principle that in ontogeny and phylogeny capabilities demanding more effort develop, respectively, evolve later than those demanding less effort, the empirical observation seems paradoxical that the meanings of concrete nouns, in ontogeny and phylogeny, are acquired earlier than those of other word classes.
Siyāvoš as a Vegetation Deity
Authors: Tavousi Maryam Nemat
Published: March 2008

Because of annual communal lamentations dedicated to Siyāvoš, he is considered to be a unique character among heroes of the Šāhnāmeh. The elements of the rituals revolving around Siyāvoš are compatible to those of vegetation deities in some other religions. Of particular interest is the cycle of birth-death-rebirth of vegetation deity that takes place according to a specific sequence of events. In the present article, the author attempts to trace conformities and nonconformities in the Siyāvoš tale as described in the Šāhnāmeh and correlates them with the life-death-rebirth cycle of vegetation deity.
Ta'ârof as a Writer's Tool in Twentieth Century Persian Literary Prose
Authors: Németh Ágnes
Published: March 2008

The present study tries to show a wider-than-usual use of ta'ârof, that is the deliberate play with the so-called “ritual courtesy, or politeness” formulas that can alter the readers' opinion about a character, for instance that result in prejudice, sympathy, etc. towards the characters. Politeness, in both everyday conversations and literary texts, is an excellent device for expressing certain individual opinions. Depending on or irrespective of the conversation partner, individual interests or opinions can be expressed or withdrawn. What I try to prove is that their use— quantity, types etc.—can be a form of expressing the author's direct attitude. I have chosen works of the “classics” of modern fiction (Sâdeq Hedâyat, Bozorg ‘Alavi, Sâdeq Čubak and Jalâl Âl Ahmad). Based on the selected examples from the works of the writers I have chosen, I attempt to demonstrate and prove my presumption. The exaggerated insistence on a certain style or just the exaggerated refusal to use a certain style can be a tool for the writer to influence—beforehand—the readers’ impression of a certain character or characters. This effect can be rough, sarcastic, etc.
From Evangelizing to Modernizing Iranians: The American Presbyterian Mission and its Iranian Students
Authors: Rostam-Kolayi Jasamin
Published: March 2008

This article examines the American Presbyterian education project in Iran from the early nineteenth century to 1940. While most literature on the subject concerns Iranian state-missionary relations and Presbyterian boys' schools in Iran, this article seeks to address the interactions between American Presbyterians, the Iranian state, and students and families of Iranian girls' schools. A study of the Presbyterians' flagship girls' school in Iran Bethel/Nurbakhsh and its sixty-six-year history reveals missionary intentions, tactics, and accomplishments, as well as the adaptations and accommodations pressed upon them by the Iranians they served. Despite the school's promotion of modern American norms and Christian teachings, the young graduates of Iran Bethel/Nurbakhsh developed a strong sense of loyalty to both Iran and Islam, thus turning an evangelist mission into an important feature of the construction of Iranian nationalism and modernity.
Myths and Bombs: War, State Popularity and the Collapse of National Mythology
Authors: Mandić Danilo
Published: March 2008

“Belgrade ‘Targets’ Find Unity ‘From Heaven,’” read the front-page headline of a somewhat staggeredNew York Times, only five days after NATO bombs began falling on Serbia. Instead of hiding in bomb shelters or, as US officials had hoped, rebelling against their government, Serbs were busy singing patriotic songs at public squares, throwing rocks at the Goethe Institute, wearing medieval Serbian military uniforms and carrying signs equating Bill Clinton to Ottoman emperors, Croatian fascists and Napoleon. Thus a population which had for years expressed nothing but discontent with its government suddenly became “unified from heaven—but by the bombs, not by God.” Uniting them “behind their soldiers, their Kosovo and even President Slobodan Milošević” was, Belgrade's then-Mayor explained, a seemingly incomprehensible mélange of “myth and superstition.”
Gender as Survival: Women's Experiences of Deportation from Romania to the Soviet Union, 1945–1950
Authors: Massino Jill
Published: March 2008

And the second day my mother came with my brother and my sister and they brought food because we didn't have anything, and she kept on shouting “Sofi, Sofi, Sofi” … there was an entire convoy, many wagons, and they had those small kind of windows like for animals … and she kept yelling,… “Sofi, Sofi, Misi, Misi” … a military man was there, at the door, and I pleaded with the officer “Please, let our mother give me some food because we have nothing” and he opened the door a tiny bit so we could pull the sack with everything through … and the next day they took us … they took us … they said they were taking us to Siberia but they took us to Donbass, and there, in Donbass, they put us in a camp.
Localness and Mobility in Belarusian Nationalism: The Tactic of Tuteishaść*
Authors: Pershai Alexander
Published: March 2008

Every nation has its own ways of telling its national story. Such narratives attempt to incorporate and explain the terms of a nation's history, culture, language, territory, economic welfare, and its citizens' sense of belonging. Some national stories are more complicated than others and require specific terminology to describe their nation and its “other.” Belarus is one of these complicated cases. Belarusian national character is often defined by the concept of tuteishaść, or “localness,” by which the people of Belarus identify themselves in relation to other nations and countries.
The “Imperial Minority”: An Interpretative Framework of the Russians in Kazakhstan in the 1990s
Authors: Peyrouse Sébastien
Published: March 2008

This paper is devoted to the Russian minorities living in Central Asia (nearly 10 million people in 1989, about 5.5 million today), and more specifically to the Russians living in Kazakhstan, who constitute the main Russian minority in the near abroad, apart from Ukraine. Unlike the Russians living in the other Central Asian republics, Russians in Kazakhstan created political parties. Kazakhstan even experienced some significant secessionist trends in the mid-1990s. Today, the political, social and economic situation of the Russian minority is rather different. Since about 2 million Russians have left the country, those who remain have tried to find their niche within the economic growth that Kazakhstan has experienced since the 2000s. The political parties and associations that represented the interests of the Russian minority have largely disappeared from the political scene. The “Russian question” no longer threatens to destabilize the territorial integrity of the country.
Case Studies: Types, Designs, and Logics of Inference
Authors: Levy Jack S.
Published: March 2008

I focus on the role of case studies in developing causal explanations. I distinguish between the theoretical purposes of case studies and the case selection strategies or research designs used to advance those objectives. I construct a typology of case studies based on their purposes: idiographic (inductive and theory-guided), hypothesis-generating, hypothesis-testing, and plausibility probe case studies. I then examine different case study research designs, including comparable cases, most and least likely cases, deviant cases, and process tracing, with attention to their different purposes and logics of inference. I address the issue of selection bias and the “single logic” debate, and I emphasize the utility of multi-method research.
Temporal Analysis of Political Instability through Descriptive Subgroup Discovery
Authors: Lambach Daniel , Gamberger Dragan
Published: March 2008

This paper analyzes the Political Instability Task Force (PITF) data set using a new methodology based on machine learning tools for subgroup discovery. While the PITF used static data, this study employs both static and dynamic descriptors covering the 5-year period before onset. The methodology provides several descriptive models of countries especially prone to political instability. For the most part, these models corroborate the PITF's findings and support earlier theoretical works. The paper also shows the value of subgroup discovery as a tool for developing a unified concept of political instability as well as for similar research designs.
At What Price Victory? The Effects of Uncertainty on Military Intervention Duration and Outcome
Authors: Sullivan Patricia L.
Published: March 2008

I extend the implications of a rationalist model of war initiation to explore the effects of uncertainty about the cost of prosecuting a war to victory on the duration and outcome of military operations. When the attributes of a potential armed conflict create uncertainty about the human and material costs of attaining a state's war aims, states are at risk of selecting themselves into long, costly, and ultimately unsuccessful military engagements. The more the actual costs of fighting exceed a state's prewar expectations, the greater the likelihood that it will eventually be pushed beyond its cost-tolerance threshold and forced to unilaterally withdraw from the conflict before it attains its war aims. At the same time, states must fight longer before they arrive at accurate estimates of what it will cost to attain their objectives when the attributes of a conflict contribute to high levels of uncertainty.
The Peace Scale: Conceptualizing and Operationalizing Non-Rivalry and Peace
Authors: Klein James P. , Goertz Gary , Diehl Paul F.
Published: March 2008

Most efforts in international relations scholarship focus on understanding war and conflict. To the extent that peace is considered, it is often treated as an afterthought or a control condition. In this paper, we construct a five-level scale of dyadic peace. We then operationalize the scale using indicators suggested by different scholarly literatures as well as measures derived from case studies. Further, we advocate the use of “anchor cases” and pair-wise comparisons to code dyadic peace in non-rivalry periods. We conclude with a pilot study of the scale, as applied to pairs of states over the period From 1816 to 2006.
A Reassessment of Democratic Pacifism at the Monadic Level of Analysis
Authors: Boehmer Charles R.
Published: March 2008

Are democracies generally peaceful? Studies have produced mixed evidence, both for and against this proposition. I review and update the literature on this topic and explore reasons why some scholars have come to emphasize those studies showing that democracies are no more or less conflict-prone than other states. This paper re-examines democracy and conflict at the state level of analysis from 1884 to 1999 using a broad sample of states and appropriate statistical estimators. The results show that democracies are less likely to initiate militarized conflicts. I also find that political competition has a stronger pacifying effect than executive constraints when disaggregating the Polity IV democracy index.
Diversity and identity in societal context: introductory remarks
Authors: Kiwan Dina
Published: March 2008

This introductory piece highlights key themes raised by Sir Bernard Crick and Professor Tariq Ramadan. Firstly I consider why citizenship is on the agenda and how these discourses are increasingly linked to discourses of diversity and identity. Secondly, I consider understandings of
integration, especially with respect to Muslims, and thirdly, multiple identities and the public/private sphere debate. I propose the concept of 'institutional multiculturalism' which entails firstly, a recognition that public institutions are not culture-neutral domains, and secondly, promoting
the process of a diverse 'authoring' in public sphere institutions to reflect the UK's diversity today.
Neural stem cells: involvement in adult neurogenesis and CNS repair
Authors: Okano Hideyuki , Sawamoto Kazunobu
Published: March 2008

Recent advances in stem cell research, including the selective expansion of neural stem cells (NSCs)in vitro, the induction of particular neural cells from embryonic stem cellsin vitro, the identification of NSCs or NSC-like cells in the adult brain and the detection of neurogenesis in the adult brain (adult neurogenesis), have laid the groundwork for the development of novel therapies aimed at inducing regeneration in the damaged central nervous system (CNS). There are two major strategies for inducing regeneration in the damaged CNS: (i) activation of the endogenous regenerative capacity and (ii) cell transplantation therapy. In this review, we summarize the recent findings from our group and others on NSCs, with respect to their role in insult-induced neurogenesis (activation of adult NSCs, proliferation of transit-amplifying cells, migration of neuroblasts and survival and maturation of the newborn neurons), and implications for therapeutic interventions, together with tactics for using cell transplantation therapy to treat the damaged CNS.
Phase contrast electron microscopy: development of thin-film phase plates and biological applications
Authors: Nagayama Kuniaki , Danev Radostin
Published: March 2008

Phase contrast transmission electron microscopy (TEM) based on thin-film phase plates has been developed and applied to biological systems. Currently, development is focused on two techniques that employ two different types of phase plates. The first technique uses a Zernike phase plate, which is made of a uniform amorphous carbon film that completely covers the aperture of an objective lens and can retard the phase of electron waves byπ/2, except at the centre where a tiny hole is drilled. The other technique uses a Hilbert phase plate, which is made of an amorphous carbon film that is twice as thick as the Zernike phase plate, covers only half of the aperture and retards the electron wave phase byπ. By combining the power of efficient phase contrast detection with the accurate preservation achieved by a cryotechnique such as vitrification, macromolecular complexes and supermolecular structures inside intact bacterial or eukaryotic cells may be visualized without staining. Phase contrast cryo-TEM has the potential to bridge the gap between cellular and molecular biology in terms of high-resolution visualization. Examples using proteins, viruses, cyanobacteria and somatic cells are provided.
Type-1 metabotropic glutamate receptor in cerebellar Purkinje cells: a key molecule responsible for long-term depression, endocannabinoid signalling and synapse elimination
Authors: Kano Masanobu , Hashimoto Kouichi , Tabata Toshihide
Published: March 2008

The cerebellum is a brain structure involved in the coordination, control and learning of movements, and elucidation of its function is an important issue. Japanese scholars have made seminal contributions in this field of neuroscience. Electrophysiological studies of the cerebellum have a long history in Japan since the pioneering works by Ito and Sasaki. Elucidation of the basic circuit diagram of the cerebellum in the 1960s was followed by the construction of cerebellar network theories and finding of their neural correlates in the 1970s. A theoretically predicted synaptic plasticity, long-term depression (LTD) at parallel fibre to Purkinje cell synapse, was demonstrated experimentally in 1982 by Ito and co-workers. Since then, Japanese neuroscientists from various disciplines participated in this field and have made major contributions to elucidate molecular mechanisms underlying LTD. An important pathway for LTD induction is type-1 metabotropic glutamate receptor (mGluR1) and its downstream signal transduction in Purkinje cells. Sugiyama and co-workers demonstrated the presence of mGluRs and Nakanishi and his pupils identified the molecular structures and functions of the mGluR family. Moreover, the authors contributed to the discovery and elucidation of several novel functions of mGluR1 in cerebellar Purkinje cells. mGluR1 turned out to be crucial for the release of endocannabinoid from Purkinje cells and the resultant retrograde suppression of transmitter release. It was also found that mGluR1 and its downstream signal transduction in Purkinje cells are indispensable for the elimination of redundant synapses during post-natal cerebellar development. This article overviews the seminal works by Japanese neuroscientists, focusing on mGluR1 signalling in cerebellar Purkinje cells.
Towards understanding of the cortical network underlying associative memory
Authors: Osada Takahiro , Adachi Yusuke , Kimura Hiroko M , Miyashita Yasushi
Published: March 2008

Declarative knowledge and experiences are represented in the association cortex and are recalled by reactivation of the neural representation. Electrophysiological experiments have revealed that associations between semantically linked visual objects are formed in neural representations in the temporal and limbic cortices. Memory traces are created by the reorganization of neural circuits. These regions are reactivated during retrieval and contribute to the contents of a memory. Two different types of retrieval signals are suggested as follows: automatic and active. One flows backward from the medial temporal lobe during the automatic retrieval process, whereas the other is conveyed as a top-down signal from the prefrontal cortex to the temporal cortex during the active retrieval process. By sending the top-down signal, the prefrontal cortex manipulates and organizes to-be-remembered information, devises strategies for retrieval and monitors the outcome. To further understand the neural mechanism of memory, the following two complementary views are needed: how the multiple cortical areas in the brain-wide network interact to orchestrate cognitive functions and how the properties of single neurons and their synaptic connections with neighbouring neurons combine to form local circuits and to exhibit the function of each cortical area. We will discuss some new methodological innovations that tackle these challenges.
Characterization of interleukin-1β mRNA expression in chicken macrophages in response to avian reovirus
Authors: Wu Yung Fu , Liu Hung Jen , Shien Jui Huang , Chiou Shiow Her , Lee Long Huw
Published: March 2008

Inhibitors of viral disassembly or RNA and protein synthesis, viral disassembly intermediates (infectious subviral particles, ISVP), binary ethylenimine-inactivated virions, and viral particles lacking genomic double-stranded (ds) RNA (empty particles) were used to assess the expression of interleukin-1β (IL-1β) mRNA in chicken (chIL-1β) macrophages in response to avian reovirus. The results demonstrate that two distinct expression patterns of chIL-1β mRNA mediated by different steps in viral replication were found. Viral disassembly was required for the induction of a rapid, transient expression pattern of chIL-1β mRNA that was rapidly induced at 30 min, with maximal levels reached by 2 h, and fell to a low level within 6 h post-inoculation, while viral RNA synthesis rather than protein translation, which was subsequent to membrane penetration, was required to induce a stable, sustained expression pattern of chIL-1β mRNA that occurred at and after 6 h post-inoculation. In addition, the induction of chIL-1β mRNA expression by the empty particles and ISVP was extremely weak, compared with the active dsRNA+ virions or binary ethylenimine-inactivated virions, suggesting that the presence of dsRNA, even if transcriptionally inactive, may be an important factor in this response.
Identification of residues in the receptor-binding domain (RBD) of the spike protein of human coronavirus NL63 that are critical for the RBD–ACE2 receptor interaction
Authors: Lin Han-Xin , Feng Yan , Wong Gillian , Wang Liping , Li Bei , Zhao Xuesen , Li Yan , Smaill Fiona , Zhang Chengsheng
Published: March 2008

Human coronavirus NL63 (NL63), a member of the group I coronaviruses, may cause acute respiratory diseases in young children and immunocompromised adults. Like severe acute respiratory syndrome coronavirus (SARS-CoV), NL63 also employs the human angiotensin-converting enzyme 2 (hACE2) receptor for cellular entry. To identify residues in the spike protein of NL63 that are important for hACE2 binding, this study first generated a series of S1-truncated variants, examined their associations with the hACE2 receptor and subsequently mapped a minimal receptor-binding domain (RBD) that consisted of 141 residues (aa 476–616) towards the C terminus of the S1 domain. The data also demonstrated that the NL63 RBD bound to hACE2 more efficiently than its full-length counterpart and had a binding efficiency comparable to the S1 or RBD of SARS-CoV. A further series of RBD variants was generated using site-directed mutagenesis and random mutant library screening assays, and identified 15 residues (C497, Y498, V499, C500, K501, R518, R530, V531, G534, G537, D538, S540, E582, W585 and T591) that appeared to be critical for the RBD–hACE2 association. These critical residues clustered in three separate regions (designated RI, RII and RIII) inside the RBD, which may represent three receptor-binding sites. These results may help to delineate the molecular interactions between the S protein of NL63 and the hACE2 receptor, and may also enhance our understanding of the pathogenesis of NL63 and SARS-CoV.
Thiopurines inhibit bovine viral diarrhea virus production in a thiopurine methyltransferase-dependent manner
Authors: Hoover Spencer , Striker Rob
Published: March 2008

The family Flaviviridae comprises positive-strand RNA viral pathogens of humans and livestock with few treatment options. We have previously shown that azathioprine (AZA) has in vitro activity against bovine viral diarrhea virus (BVDV). While the mechanism of inhibition is unknown, AZA and related thiopurine nucleoside analogues have been used as immunosuppressants for decades and both AZA metabolites and cellular genes involved in AZA metabolism have been extensively characterized. Here, we show that only certain riboside metabolites have antiviral activity and identify the most potent known antiviral AZA metabolite as 6-methylmercaptopurine riboside (6MMPr). The antiviral activity of 6MMPr is antagonized by adenosine, and is specific to BVDV and not to the related yellow fever virus. An essential step in the conversion of AZA to 6MMPr is the addition of a methyl group onto the sulfur atom attached to position six of the purine ring. Intracellularly, the methyl group is added by thiopurine methyltransferase (TPMT), an S-adenosyl methionine-dependent methyltransferase. Either chemically bypassing or inhibiting TPMT modulates antiviral activity of AZA metabolites. TPMT exists in several variants with varying levels of activity and since 6MMPr is a potent antiviral, the antiviral activity of AZA may be modulated by host genetics.
Epstein–Barr virus nuclear antigen (EBNA) 3A induces the expression of and interacts with a subset of chaperones and co-chaperones
Authors: Young Paul , Anderton Emma , Paschos Kostas , White Rob , Allday Martin J.
Published: March 2008

Viral nuclear oncoproteins EBNA3A and EBNA3C are essential for the efficient immortalization of B cells by Epstein–Barr virus (EBV) in vitro and it is assumed that they play an essential role in viral persistence in the human host. In order to identify cellular genes regulated by EBNA3A expression, cDNA encoding EBNA3A was incorporated into a recombinant adenoviral vector. Microarray analysis of human diploid fibroblasts infected with either adenovirus EBNA3A or an empty control adenovirus consistently showed an EBNA3A-specific induction of mRNA corresponding to the chaperones Hsp70 and Hsp70B/B′ and co-chaperones Bag3 and DNAJA1/Hsp40. Analysis of infected fibroblasts by real-time quantitative RT-PCR and Western blotting confirmed that EBNA3A, but not EBNA3C, induced expression of Hsp70, Hsp70B/B′, Bag3 and DNAJA1/Hsp40. This was also confirmed in a stable, inducible expression system. EBNA3A activated transcription from the Hsp70B promoter, but not multimerized heat-shock elements in transient transfection assays, consistent with specific chaperone and co-chaperone upregulation. Co-immunoprecipitation experiments suggest that EBNA3A can form a complex with the chaperone/co-chaperone proteins in both adenovirus-infected cells and EBV-immortalized lymphoblastoid cell lines. Consistent with this, induction of EBNA3A resulted in redistribution of Hsp70 from the cytoplasm to the nucleus. EBNA3A therefore specifically induces (and then interacts with) all of the factors necessary for an active Hsp70 chaperone complex.