bluuebunny/crossref_metadata_2025 huggingface dataset:
Revealing spatially heterogeneous relaxation in a model nanocomposite
Authors: Cheng Shiwang , Mirigian Stephen , Carrillo Jan-Michael Y. , Bocharova Vera , Sumpter Bobby G. , Schweizer Kenneth S. , Sokolov Alexei P.
Published: November 2015

The detailed nature of spatially heterogeneous dynamics of glycerol-silica nanocomposites is unraveled by combining dielectric spectroscopy with atomistic simulation and statistical mechanical theory. Analysis of the spatial mobility gradient shows no “glassy” layer, but the α-relaxation time near the nanoparticle grows with cooling faster than the α-relaxation time in the bulk and is ∼20 times longer at low temperatures. The interfacial layer thickness increases from ∼1.8 nm at higher temperatures to ∼3.5 nm upon cooling to near bulk Tg. A real space microscopic description of the mobility gradient is constructed by synergistically combining high temperature atomistic simulation with theory. Our analysis suggests that the interfacial slowing down arises mainly due to an increase of the local cage scale barrier for activated hopping induced by enhanced packing and densification near the nanoparticle surface. The theory is employed to predict how local surface densification can be manipulated to control layer dynamics and shear rigidity over a wide temperature range.
Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS
Authors: Thomae R. , Conradie J. , Fourie D. , Mira J. , Nemulodi F. , Kuechler D. , Toivanen V.
Published: November 2015

At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.
Comparison of dust charging between orbital-motion-limited theory and particle-in-cell simulations
Authors: Delzanno Gian Luca , Tang Xian-Zhu
Published: November 2015

The Orbital-Motion-Limited (OML) theory has been modified to predict the dust charge and the results were contrasted with the Whipple approximation [X. Z. Tang and G. L. Delzanno, Phys. Plasmas 21, 123708 (2014)]. To further establish its regime of applicability, in this paper, the OML predictions (for a non-electron-emitting, spherical dust grain at rest in a collisionless, unmagnetized plasma) are compared with particle-in-cell simulations that retain the absorption radius effect. It is found that for large dust grain radius rd relative to the plasma Debye length λD, the revised OML theory remains a very good approximation as, for the parameters considered (rd/λD ≤ 10, equal electron and ion temperatures), it yields the dust charge to within 20% accuracy. This is a substantial improvement over the Whipple approximation. The dust collected currents and energy fluxes, which remain the same in the revised and standard OML theories, are accurate to within 15%–30%.
Preliminary design of a RFQ direct injection scheme for the IsoDAR high intensity H2+ cyclotron
Authors: Winklehner D. , Hamm R. , Alonso J. , Conrad J. M. , Axani S.
Published: November 2015

IsoDAR (Isotope Decay-At-Rest) is a novel experiment designed to measure neutrino oscillations through ν̄e disappearance, thus providing a definitive search for sterile neutrinos. In order to generate the necessary anti-neutrino flux, a high intensity primary proton beam is needed. In IsoDAR, H2+ is accelerated and is stripped into protons just before the target, to overcome space charge issues at injection. As part of the design, we have refined an old proposal to use a RFQ to axially inject bunched H2+ ions into the driver cyclotron. This method has several advantages over a classical low energy beam transport (LEBT) design: (1) The bunching efficiency is higher than for the previously considered two-gap buncher and thus the overall injection efficiency is higher. This relaxes the constraints on the H2+ current required from the ion source. (2) The overall length of the LEBT can be reduced. (3) The RFQ can also accelerate the ions. This enables the ion source platform high voltage to be reduced from 70 kV to 15 kV, making underground installation easier. We are presenting the preliminary RFQ design parameters and first beam dynamics simulations from the ion source to the spiral inflector entrance.
RF synchronized short pulse laser ion source
Authors: Fuwa Yasuhiro , Iwashita Yoshihisa , Tongu Hiromu , Inoue Shunsuke , Hashida Masaki , Sakabe Shuji , Okamura Masahiro , Yamazaki Atsushi
Published: November 2015

A laser ion source that produces shortly bunched ion beam is proposed. In this ion source, ions are extracted immediately after the generation of laser plasma by an ultra-short pulse laser before its diffusion. The ions can be injected into radio frequency (RF) accelerating bucket of a subsequent accelerator. As a proof-of-principle experiment of the ion source, a RF resonator is prepared and H2 gas was ionized by a short pulse laser in the RF electric field in the resonator. As a result, bunched ions with 1.2 mA peak current and 5 ns pulse length were observed at the exit of RF resonator by a probe.
On-chip recalcification of citrated whole blood using a microfluidic herringbone mixer
Authors: Lehmann Marcus , Wallbank Alison M. , Dennis Kimberly A. , Wufsus Adam R. , Davis Kara M. , Rana Kuldeepsinh , Neeves Keith B.
Published: November 2015

In vitro assays of platelet function and coagulation are typically performed in the presence of an anticoagulant. The divalent cation chelator sodium citrate is among the most common because its effect on coagulation is reversible upon reintroduction of divalent cations. Adding divalent cations into citrated blood by batch mixing leads to platelet activation and initiation of coagulation after several minutes, thus limiting the time blood can be used before spontaneously clotting. In this work, we describe a herringbone microfluidic mixer to continuously introduce divalent cations into citrated blood. The mixing ratio, defined as the ratio of the volumetric flow rates of citrated blood and recalcification buffer, can be adjusted by changing the relative inlet pressures of these two solutions. This feature is useful in whole blood assays in order to account for differences in hematocrit, and thus viscosity. The recalcification process in the herringbone mixer does not activate platelets. The advantage of this continuous mixing approach is demonstrated in microfluidic vascular injury model in which platelets and fibrin accumulate on a collagen-tissue factor surface under flow. Continuous recalcification with the herringbone mixer allowed for flow assay times of up to 30 min, more than three times longer than the time achieved by batch recalcification. This continuous mixer allows for measurements of thrombus formation, remodeling, and fibrinolysis in vitro over time scales that are relevant to these physiological processes.
Comparative study of local atomic structures in Zr2CuxNi1−x (x = 0, 0.5, 1) metallic glasses
Authors: Huang Yuxiang , Huang Li , Wang C. Z. , Kramer M. J. , Ho K. M.
Published: November 2015

Extensive analysis has been performed to understand the key structural motifs accounting for the difference in glass forming ability in the Zr-Cu and Zr-Ni binary alloy systems. Here, the reliable atomic structure models of Zr2CuxNi1−x (x = 0, 0.5, 1) are constructed using the combination of X-ray diffraction experiments, ab initio molecular dynamics simulations and a constrained reverse Monte Carlo method. We observe a systematic variation of the interatomic distance of different atomic pairs with respect to the alloy composition. The ideal icosahedral content in all samples is limited, despite the high content of five-fold symmetry motifs. We also demonstrate that the population of Z-clusters in Zr2Cu glass is much higher than that in the Zr2Ni and Zr2Cu0.5Ni0.5 samples. And Z12 ⟨0, 0, 12, 0⟩ Voronoi polyhedra clusters prefer to form around Cu atoms, while Ni-centered clusters are more like Z11 ⟨0, 2, 8, 1⟩ clusters, which is less energetically stable compared to Z12 clusters. These two different structural properties may account for the higher glass forming ability of Zr2Cu alloy than that of Zr2Ni alloy.
Numerical validation of axial plasma momentum lost to a lateral wall induced by neutral depletion
Authors: Takao Yoshinori , Takahashi Kazunori
Published: November 2015

Momentum imparted to a lateral wall of a compact inductively coupled plasma thruster is numerically investigated for argon and xenon gases by a particle-in-cell simulation with Monte Carlo collisions (PIC-MCC). Axial plasma momentum lost to a lateral wall is clearly shown when axial depletion of the neutrals is enhanced, which is in qualitative agreement with the result in a recent experiment using a helicon plasma source [Takahashi et al., Phys. Rev. Lett. 114, 195001 (2015)]. The PIC-MCC calculations demonstrate that the neutral depletion causes an axially asymmetric profile of the plasma density and potential, leading to axial ion acceleration and the non-negligible net axial force exerted to the lateral wall in the opposite direction of the thrust.
A new interpretation for performance improvement of high-efficiency vertical blue light-emitting diodes by InGaN/GaN superlattices
Authors: Quan Zhijue , Liu Junlin , Fang Fang , Wang Guangxu , Jiang Fengyi
Published: November 2015

The effect of InGaN/GaN superlattices (SLs) on quantum efficiency and forward voltage of vertical blue InGaN/GaN multiple quantum well (MQW) light-emitting diodes (LED) grown on Si substrate has been experimentally and theoretically investigated. We have prepared two LED samples, in which the 30 and 45 periods of SLs are inserted between MQW active layers and n-GaN layer, respectively. Electroluminescence measurement shows that the LED with 45 periods of SLs has higher quantum efficiency but lower forward voltage. It is observed that V-shaped pits grow up in size with an increase in SLs period number by means of scan transmission electron microscope and secondary ion mass spectrometry. Further numerical simulations confirm that the performance improvement of LED by SLs is mainly ascribed to enhancing hole injection from the V-shaped pits.
Response of asymmetric carbon nanotube network devices to sub-terahertz and terahertz radiation
Authors: Gayduchenko I. , Kardakova A. , Fedorov G. , Voronov B. , Finkel M. , Jiménez D. , Morozov S. , Presniakov M. , Goltsman G.
Published: November 2015

Demand for efficient terahertz radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. It was maintained that photothermoelectric effect under certain conditions results in strong response of such devices to terahertz radiation even at room temperature. In this work, we investigate different mechanisms underlying the response of asymmetric carbon nanotube (CNT) based devices to sub-terahertz and terahertz radiation. Our structures are formed with CNT networks instead of individual CNTs so that effects probed are more generic and not caused by peculiarities of an individual nanoscale object. We conclude that the DC voltage response observed in our structures is not only thermal in origin. So called diode-type response caused by asymmetry of the device IV characteristic turns out to be dominant at room temperature. Quantitative analysis provides further routes for the optimization of the device configuration, which may result in appearance of novel terahertz radiation detectors.
Border trap reduction in Al2O3/InGaAs gate stacks
Authors: Tang Kechao , Winter Roy , Zhang Liangliang , Droopad Ravi , Eizenberg Moshe , McIntyre Paul C.
Published: November 2015

The effect of Al2O3 atomic layer deposition (ALD) temperature on the border trap density (Nbt) of Al2O3/InGaAs gate stacks is investigated quantitatively, and we demonstrate that lowering the trimethylaluminum (TMA)/water vapor ALD temperature from 270 °C to 120 °C significantly reduces Nbt. The reduction of Nbt coincides with increased hydrogen incorporation in low temperature ALD-grown Al2O3 films during post-gate metal forming gas annealing. It is also found that large-dose (∼6000 L) exposure of the In0.53Ga0.47As (100) surface to TMA immediately after thermal desorption of a protective As2 capping layer is an important step to guarantee the uniformity and reproducibility of high quality Al2O3/InGaAs samples made at low ALD temperatures.
Realization of an all optical exciton-polariton router
Authors: Marsault Félix , Nguyen Hai Son , Tanese Dimitrii , Lemaître Aristide , Galopin Elisabeth , Sagnes Isabelle , Amo Alberto , Bloch Jacqueline
Published: November 2015

We report on the experimental realization of an all optical router for exciton-polaritons. This device is based on the design proposed by Flayac and Savenko [Appl. Phys. Lett. 103, 201105 (2013)], in which a zero-dimensional island is connected through tunnel barriers to two periodically modulated wires of different periods. Selective transmission of polaritons injected in the island, into either of the two wires, is achieved by tuning the energy of the island state across the band structure of the modulated wires. We demonstrate routing of ps polariton pulses using an optical control beam which controls the energy of the island quantum states, thanks to polariton-exciton interactions.
Direct observation of oxygen-vacancy-enhanced polarization in a SrTiO3-buffered ferroelectric BaTiO3 film on GaAs
Authors: Qiao Qiao , Zhang Yuyang , Contreras-Guerrero Rocio , Droopad Ravi , Pantelides Sokrates T. , Pennycook Stephen J. , Ogut Serdar , Klie Robert F.
Published: November 2015

The integration of functional oxide thin-films on compound semiconductors can lead to a class of reconfigurable spin-based optoelectronic devices if defect-free, fully reversible active layers are stabilized. However, previous first-principles calculations predicted that SrTiO3 thin films grown on Si exhibit pinned ferroelectric behavior that is not switchable, due to the presence of interfacial vacancies. Meanwhile, piezoresponse force microscopy measurements have demonstrated ferroelectricity in BaTiO3 grown on semiconductor substrates. The presence of interfacial oxygen vacancies in such complex-oxide/semiconductor systems remains unexplored, and their effect on ferroelectricity is controversial. Here, we use a combination of aberration-corrected scanning transmission electron microscopy and first-principles density functional theory modeling to examine the role of interfacial oxygen vacancies on the ferroelectric polarization of a BaTiO3 thin film grown on GaAs. We demonstrate that interfacial oxygen vacancies enhance the polar discontinuity (and thus the single domain, out-of-plane polarization pinning in BaTiO3), and propose that the presence of surface charge screening allows the formation of switchable domains.
Solar-blind field-emission diamond ultraviolet detector
Authors: Mendoza Frank , Makarov Vladimir , Weiner Brad R. , Morell Gerardo
Published: November 2015

We report our studies on the responsivity of sulfur-doped diamond films to ultraviolet radiation using two types of device configurations: the planar configuration with electrodes directly on the diamond surface, and the electron field emission configuration with a bias electrode suspended above the diamond surface. Diamond films of different grain sizes were employed: microcrystalline diamond, sub-microcrystalline diamond, and nanocrystalline diamond. The responsivity values of diamond films in the field emission configuration reached ∼10 mA/W at around 220 nm, which is ∼40% higher than that of the planar configuration. These responsivity values of diamond films are comparable to those of commercially available photodiodes in the wavelength range of 210–300 nm, but with the advantage of being solar blind. The responsivity data were correlated with the bandgap structure of sulfur-doped diamond.
Strong domain configuration dependence of the nonlinear dielectric response in (K,Na)NbO3-based ceramics
Authors: Huan Yu , Wang Xiaohui , Li Longtu , Koruza Jurij
Published: November 2015

The nonlinear dielectric response in (Na0.52K0.4425Li0.0375)(Nb0.92−xTaxSb0.08)O3 ceramics with different amounts of Ta was measured using subcoercive electric fields and quantified by the Rayleigh model. The irreversible extrinsic contribution, mainly caused by the irreversible domain wall translation, was strongly dependent on the domain configuration. The irreversible extrinsic contributions remained approximately the same within the single-phase regions, either orthorhombic or tetragonal, due to the similar domain morphology. However, in the polymorphic phase transition region, the domain wall density was increased by minimized domain size, as observed by transmission electron microscopy. This resulted in constrained domain wall motion due to self-clamping and reduced the irreversible extrinsic contribution.
Large low-field positive magnetoresistance in nonmagnetic half-Heusler ScPtBi single crystal
Authors: Hou Zhipeng , Wang Yue , Liu Enke , Zhang Hongwei , Wang Wenhong , Wu Guangheng
Published: November 2015

High-quality nonmagnetic half-Heusler ScPtBi single crystals were synthesized by a Bi self-flux method. This compound was revealed to be a hole-dominated semimetal with a large low-field magnetoresistance up to 240% at 2 K in a magnetic field of 1 T. Magneto-transport measurements demonstrated that the large low-field magnetoresistance effect resulted from the coexistence of field-induced metal-semiconductor transition and weak-antilocalization effect. Moreover, Hall measurements indicated that ScPtBi single crystal showed a high mobility over a wide temperature region even up to room temperature (4050 cm2V−1s−1 at 2 K–2016 cm2V−1s−1 at 300 K). These findings not only suggest the nonmagnetic ScPtBi semimetal a potential material candidate for applications in high-sensitivity magnetic sensors but also are of great significance to comprehensively understand the rare-earth based half-Heusler compounds.
Giant permittivity and electrostriction induced by dynamic Jahn-Teller and pseudo Jahn-Teller effects
Authors: Bersuker Isaac B.
Published: November 2015

We revealed specific properties of molecular systems and solids with dynamic Jahn-Teller effect (JTE) or pseudo JTE (PJTE) that enhance permittivity and electrostriction by several orders of magnitude. These effects occur due to the spontaneous symmetry breaking at the JTE or PJTE centers resulting in several equivalent minima of the adiabatic potential energy surface in which the system is dipolar-distorted in different directions. In the absence of external perturbations the distortions resonate between the equivalent orientations via tunneling between the minima, but an external electric field, similar to external strain considered earlier [I. B. Bersuker, Appl. Phys. Lett. 106, 022903 (2015)], makes the minima nonequivalent, trapping all the centers polar-distorted along one direction. This results in an orientational contribution to the polarization and electrostriction of the system which is much stronger than the displacive one. Under this effect, the estimated permittivity and electrostriction of paraelectric BaTiO3 and similar crystals is enhanced by approximately three orders of magnitude, in agreement with experimental data. A variety of many other systems are expected to possess similar properties.
Mobility enhancement in graphene transistors on low temperature pulsed laser deposited boron nitride
Authors: Uddin Md Ahsan , Glavin Nicholas , Singh Amol , Naguy Rachel , Jespersen Michael , Voevodin Andrey , Koley Goutam
Published: November 2015

Low temperature pulsed laser deposited (PLD) ultrathin boron nitride (BN) on SiO2 was investigated as a dielectric for graphene electronics, and a significant enhancement in electrical transport properties of graphene/PLD BN compared to graphene/SiO2 has been observed. Graphene synthesized by chemical vapor deposition and transferred on PLD deposited and annealed BN exhibited up to three times higher field effect mobility compared to graphene on the SiO2 substrate. Graphene field effect transistor devices fabricated on 5 nm BN/SiO2 (300 nm) yielded maximum hole and electron mobility of 4980 and 4200 cm2/V s, respectively. In addition, significant improvement in carrier homogeneity and reduction in extrinsic doping in graphene on BN has been observed. An average Dirac point of 3.5 V and residual carrier concentration of 7.65 × 1011 cm−2 was observed for graphene transferred on 5 nm BN at ambient condition. The overall performance improvement on PLD BN can be attributed to dielectric screening of charged impurities, similar crystal structure and phonon modes, and reduced substrate induced doping.
The extent of functional redundancy changes as species’ roles shift in different environments
Authors: Fetzer Ingo , Johst Karin , Schäwe Robert , Banitz Thomas , Harms Hauke , Chatzinotas Antonis
Published: November 2015

Significance

It is currently unclear how biodiversity loss affects ecosystem functioning. The concept of functional redundancy implies that species loss is compensated by other species contributing similarly to functioning. Functional redundancy can be revealed by the relationship between biodiversity and ecosystem functioning (e.g., biomass growth). The functioning of an ecosystem remains unaffected if redundant species are removed but decreases if the removed species have unique roles. Most research on biodiversity-ecosystem functioning (BEF) relationships hitherto was restricted to one single set of environmental conditions. Using a microbial model system, we explored this relationship in different environments. We found that the environmental conditions are pivotal when drawing conclusions about functional redundancy because BEF relationships drastically differ due to changing species roles and interactions.
Defective histone supply causes changes in RNA polymerase II elongation rate and cotranscriptional pre-mRNA splicing
Authors: Jimeno-González Silvia , Payán-Bravo Laura , Muñoz-Cabello Ana M. , Guijo Macarena , Gutierrez Gabriel , Prado Félix , Reyes José C.
Published: November 2015

Significance

The study of the role of histones in transcription in mammals has been hindered by the existence of large gene families encoding every histone subunit. Here we reduce the level of canonical histones in a human cell line by silencing stem-loop–binding protein, a histone mRNA regulatory factor. We show that canonical histone depletion increases the RNA polymerase II (RNAPII) elongation rate and temporally separates transcription and splicing. Furthermore, histone depletion also causes several pre-mRNA splicing defects, including skipping of alternative exons and intron retention. Thus we demonstrate that the correct histone supply is required to control the RNAPII elongation rate and pre-mRNA splicing.
Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins
Authors: Meng Xiangzhi , Krumm Brian , Li Yongchao , Deng Junpeng , Xiang Yan
Published: November 2015

Significance

Productive viral replication requires overcoming many barriers posed by the host innate immune system. Human sterile alpha motif domain-containing 9 (SAMD9) is a newly identified antiviral factor that is specifically targeted by poxvirus proteins belonging to the C7 family of host-range factors. Here we provide the first, to our knowledge, atomic view of two functionally divergent proteins from the C7 family and determine the molecular basis that dictates whether they can target SAMD9 effectively. Our studies of distantly related C7 family members suggest that SAMD9 is an evolutionally conserved immune barrier that has been overcome successfully by diverse mammalian poxviruses.
Tatarstan: Adjusting to life in Putin's Russia
Authors: Graney Kate
Published: November 2015

A little-noted but interesting aspect of the Russian annexation of Crimea in March 2014 was Vladimir Putin's government's attempt to enlist officials from the Republic of Tatarstan to smooth the transition of Crimea back to Russian rule. It makes sense — the Crimean and Volga Tatars are ethnic, linguistic, and religious kin, and both trace their history of statehood back to the Golden Horde successor khanates of the fifteenth and sixteenth centuries. The Crimean Khanate maintained its independence far longer than Kazan was able to; while the defeat of Kazan in 1552 marked the beginning of the expansion of the modern Russian Empire under Ivan IV, the Crimean Khanate retained some form of autonomy until nearly the end of the eighteenth century. During the ensuing years, the fortunes of the two peoples and their states reversed yet again; Tatarstan emerged from Soviet rule as a powerful actor determined to make the new Russian Federation truly a federal state in practice as well as on paper (in part by invoking the heritage of the Kazan Khanate). In contrast the Crimean Tatars, never having recovered demographically or politically from their forced exile to Central Asia by Stalin during World War II, struggled to establish some form of cultural and political autonomy as part of a newly independent Ukraine.
Incorporating Ecology into Survey Design: Monitoring the Recruitment of Age-0 Gags in the Eastern Gulf of Mexico
Authors: Switzer Theodore S. , Keenan Sean F. , Stevens Phillip W. , McMichael Robert H. , MacDonald Timothy C.
Published: November 2015

We developed a multiple-gear survey (183-m haul seine and 6.1-m otter trawl) that was designed to supplement long-term, fishery-independent survey data on age-0 Gags Mycteroperca microlepis in Apalachicola Bay, Tampa Bay, and Charlotte Harbor, Florida. The supplemental survey design specifically considered juvenile Gag recruitment ecology and thus targeted the deep, polyhaline seagrass habitats that are utilized by age-0 Gags yet infrequently sampled. It also expanded the spatial coverage of ongoing surveys to include two unsampled estuaries (St. Andrew Bay and Big Bend [Apalachee Bay]) where Gag recruitment had been documented. Analyses of data collected in long-term and supplemental surveys (2008–2012) demonstrated the effectiveness of this sampling approach. The size ranges of Gags collected in long-term and supplemental surveys were similar, but age-0 individuals were captured more frequently and CPUE was significantly higher in the supplemental surveys. Interannual patterns of variability in Gag recruitment were similar between gear types and among sampling designs, although the coefficient of variation was lowest for the combined data from long-term and supplemental seine surveys. Data from these complementary surveys will improve our ability to characterize age-0 Gag recruitment. Nevertheless, additional information on habitat availability—combined with a better understanding of the estuarine systems' relative contributions to nearshore Gag populations—will be required to maximize the utility of these data in predicting fisheries productivity.

Received July 24, 2014; accepted August 3, 2015
Political utopia or Potemkin village? Italian travellers to the Soviet Union in the early Cold War
Authors: Lee Joanne
Published: November 2015

Situated on the border between the capitalist West and Communist East, and with the largest Communist party in Western Europe, Italy found itself at the centre of global ideological struggles in the early Cold War years. A number of Italian writers and intellectuals who had joined the PCI (Partito Comunista Italiano) during the Resistance had hoped that the party would play a central role in the post-war reconstruction of Italy and were attracted to the Soviet Union as an example of Communism in action. This article centres on accounts of journeys to the USSR by Sibilla Aleramo, Renata Viganò and Italo Calvino. It will argue that although their writings portray a largely positive vision of the USSR, they should not be dismissed as naive, or worse, disingenuous travellers whose willingness to embrace Soviet-style Communism was based on a wholescale rejection of Western society and its values (see P. Hollander's 1998 [1981] work,Political Pilgrims: Western Intellectuals in Search of the Good Society). Rather, the article shows how their accounts of the USSR shed light on the writers' relationship with the PCI and argues that the views expressed in the travelogues emerge from the writers' personal experiences of war and resistance, a fervent desire to position themselves as anti-Fascist intellectuals, and their concerns regarding the direction that Italian politics was taking at a pivotal moment in the nation's history.
The Anatomy of Growth and Development in Sub-Saharan Africa
Authors: Thorbecke Erik
Published: November 2015

The major objectives of this chapter are, first, to analyse the interrelationship among economic growth, inequality, and poverty; and, second, to propose a typology of countries within sub-Saharan Africa (SSA) based on the different initial conditions they face and that can be used to derive appropriate development strategies. The typology of countries proposed in this chapter is derived from four distinct hierarchically ordered criteria: first, the role and quality of institutions (failed and functioning states); second, the role of agriculture for development and its contribution to growth and poverty reduction (high vs. low potential); third, the role of resources (resource-scarce vs. resource-rich countries); and, fourth, the role of geography (coastal vs. landlocked countries). These criteria yielded a classification consisting of six relatively distinct categories of countries. In turn, different development strategies adapted to the initial conditions of each of the six categories of countries are presented.
Is Poverty a Binding Constraint on Growth in Sub-Saharan Africa?
Authors: Duclos Jean-Yves , O’Connell Stephen A.
Published: November 2015

Is poverty a binding constraint on economic growth in sub-Saharan Africa? Plausible theories of economy-wide poverty traps abound, but the empirical cross-country growth literature is indecisive on the existence of multiple equilibria and is likely to remain so. This chapter introduces the weaker concept of development traps, defined as intervals of income over which growth is low and conditional convergence fails. The chapter argues that development traps are of broader empirical relevance than poverty traps, both at the aggregate level and for households. The chapter argues that the most promising directions for research involve microeconomic investigations of the effects of poverty on productivity. The chapter reviews the dominant mechanisms through which these effects may emerge and suggests specific avenues for country-based research.
Spatial Inequality and its Implications for Growth–Poverty-Reduction Relations
Authors: McKay Andy , Perge Emilie
Published: November 2015

This chapter focuses on the interrelation between spatial inequality and growth. A key insight of the new economic geography literature is that agglomeration, urbanization, and migration are often key features associated with growth, but create the risk that growth may be spatially unequal, at least in the short to medium term. The chapter then discusses the measurement of spatial inequality, and reviews a significant body of evidence about the association between spatial inequality and economic development. In the context of sub-Saharan Africa, a particular concern is that changes in spatial inequality may align with pre-existing ethnic, religious, and other divides. Sub-Saharan Africa faces a difficult challenge in balancing the need for continued growth, often facilitated by forces of concentration of production and population, with the need to take policy actions to check the rise of potentially destructive forms of spatial inequality.
Existentials and Locatives in Romance Dialects of Italy
Authors: Bentley Delia , Ciconte Francesco Maria , Cruschina Silvio
Published: November 2015

This volume provides the first ever large-scale comparative treatment of there sentences (there copula NP), reporting the results of a survey of Italo-Romance and Sardinian dialects of Italy. The volume comprises detailed discussions of focus structure, predication and argument realization, the definiteness effects, and the linking from semantics to syntax in there sentences, advancing novel proposals in each case. The testing of influential hypotheses on existential constructions against first-hand dialect evidence leads the book to argue that existential and locative there sentences differ in focus structure and semantics, although their not being predicate focus constructions and the non-canonicality of the predicate—which is typically referential—is reflected in their shared morphosyntactic features. The hypothesis that the pivot is the predicate of the existential construction is adopted in the analysis, although a distinction is drawn between referential and non-referential pivots, which explains variation in pivot behaviour in morphosyntax. The volume also provides the historical background of Romance there sentences, relying on the findings of the analysis of a substantial corpus of early Italo-Romance vernacular texts.
Global copy number profiling of cancer genomes
Authors: Wang Xuefeng , Chen Mengjie , Yu Xiaoqing , Pornputtapong Natapol , Chen Hao , Zhang Nancy R. , Powers R. Scott , Krauthammer Michael
Published: November 2015

Summary: In this article, we introduce a robust and efficient strategy for deriving global and allele-specific copy number alternations (CNA) from cancer whole exome sequencing data based on Log R ratios and B-allele frequencies. Applying the approach to the analysis of over 200 skin cancer samples, we demonstrate its utility for discovering distinct CNA events and for deriving ancillary information such as tumor purity.

Availability and implementation:  https://github.com/xfwang/CLOSE

Contact:  xuefeng.wang@stonybrook.edu or michael.krauthammer@yale.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
JSpeciesWS: a web server for prokaryotic species circumscription based on pairwise genome comparison
Authors: Richter Michael , Rosselló-Móra Ramon , Oliver Glöckner Frank , Peplies Jörg
Published: November 2015

Summary: JSpecies Web Server (JSpeciesWS) is a user-friendly online service for in silico calculating the extent of identity between two genomes, a parameter routinely used in the process of polyphasic microbial species circumscription. The service measures the average nucleotide identity (ANI) based on BLAST+ (ANIb) and MUMmer (ANIm), as well as correlation indexes of tetra-nucleotide signatures (Tetra). In addition, it provides a Tetra Correlation Search function, which allows to rapidly compare selected genomes against a continuously updated reference database with currently about 32 000 published whole and draft genome sequences. For comparison, own genomes can be uploaded and references can be selected from the JSpeciesWS reference database. The service indicates whether two genomes share genomic identities above or below the species embracing thresholds, and serves as a fast way to allocate unknown genomes in the frame of the hitherto sequenced species.

Availability and implementation: JSpeciesWS is available at http://jspecies.ribohost.com/jspeciesws.

Supplementary information: Supplementary data are available at Bioinformatics online.

Contact:  mrichter@ribocon.com
Baudelaire and Feminine Singularity
Authors: Chatterjee Ronjaunee
Published: November 2015

This article revisits the representation of gender and femininity in Baudelaire's poems about the city, arguing that these works reveal a vision of femininity that cannot be reduced to the particularity through which the nineteenth-century individual is codified. While feminine figures abound in Baudelaire's œuvre, most critical readings of the poet have concentrated on the tendency towards objectification, and even denigration, in his portrayal of women. By contrast, in its early stages this article reads ‘À une passante’ in conjunction with Baudelaire's observations from
Mon Cœur mis à nu
,
Fusées
, and
Le Peintre de la vie moderne
, suggesting that a form of femininity that I shall call ‘feminine singularity’ crystallizes in his work, and that it resists collectivization under the broader tenets of urban capital and political liberalism. The subsequent stages of the article discuss ‘Les Sept Vieillards’ and ‘Les Petites Vieilles’, arguing that there is a redrawing of gendered individuation in the
Tableaux parisiens
. Both of these poems approach gender ironically, using a grotesque mode of serialization to dissolve a conventional understanding of sexual difference predicated on binaries, reproduction, and heterosexual desire.
On Garréta on Proust
Authors: Baldwin Thomas
Published: November 2015

This article explores Anne F. Garréta's engagements with Marcel Proust's
À la recherche du temps perdu
in
La Décomposition
(1999). I argue that Garréta's various ‘rewritings’ of Proust's novel supply a new image of the productive tensions between literary works and critical or novelistic approaches to them and simultaneously resist a tendency to reproduce and consume Proust's work as a cultural fetish. In examining Garréta's creation of a series of interfaces with passages in
À la recherche
, I suggest that some readers of
La Décomposition
encounter a ‘virtual’ text that shares some of the features of both authors' novels but is identical to neither. I also consider the ways in which Roland Barthes's understanding of Proust and of Proust criticism more generally can help us to appreciate the significance of what Garréta has done.
csaw: a Bioconductor package for differential binding analysis of ChIP-seq data using sliding windows
Authors: Lun Aaron T.L. , Smyth Gordon K.
Published: November 2015

Chromatin immunoprecipitation with massively parallel sequencing (ChIP-seq) is widely used to identify binding sites for a target protein in the genome. An important scientific application is to identify changes in protein binding between different treatment conditions, i.e. to detect differential binding. This can reveal potential mechanisms through which changes in binding may contribute to the treatment effect. The csaw package provides a framework for the de novo detection of differentially bound genomic regions. It uses a window-based strategy to summarize read counts across the genome. It exploits existing statistical software to test for significant differences in each window. Finally, it clusters windows into regions for output and controls the false discovery rate properly over all detected regions. The csaw package can handle arbitrarily complex experimental designs involving biological replicates. It can be applied to both transcription factor and histone mark datasets, and, more generally, to any type of sequencing data measuring genomic coverage. csaw performs favorably against existing methods for de novo DB analyses on both simulated and real data. csaw is implemented as a R software package and is freely available from the open-source Bioconductor project.
Multiple Cis-acting elements modulate programmed -1 ribosomal frameshifting in Pea enation mosaic virus
Authors: Gao Feng , Simon Anne E.
Published: November 2015

Programmed -1 ribosomal frameshifting (-1 PRF) is used by many positive-strand RNA viruses for translation of required products. Despite extensive studies, it remains unresolved how cis-elements just downstream of the recoding site promote a precise level of frameshifting. The Umbravirus Pea enation mosaic virus RNA2 expresses its RNA polymerase by -1 PRF of the 5′-proximal ORF (p33). Three hairpins located in the vicinity of the recoding site are phylogenetically conserved among Umbraviruses. The central Recoding Stimulatory Element (RSE), located downstream of the p33 termination codon, is a large hairpin with two asymmetric internal loops. Mutational analyses revealed that sequences throughout the RSE and the RSE lower stem (LS) structure are important for frameshifting. SHAPE probing of mutants indicated the presence of higher order structure, and sequences in the LS may also adapt an alternative conformation. Long-distance pairing between the RSE and a 3′ terminal hairpin was less critical when the LS structure was stabilized. A basal level of frameshifting occurring in the absence of the RSE increases to 72% of wild-type when a hairpin upstream of the slippery site is also deleted. These results suggest that suppression of frameshifting may be needed in the absence of an active RSE conformation.
Impact of Genetic Mutations and Health Plan Access to Therapies on Treatment Response and Drug Costs Related to Tyrosine Kinase Inhibitor Treatment Among Patients With Chronic Myelogenous Leukemia
Authors: Jabbour Elias , Makenbaeva Dinara , Lingohr-Smith Melissa , Lin Jay
Published: November 2015

Objectives:

This study assessed treatment responses and economic consequences of limiting access to the second-generation BCR-ABL1 tyrosine kinase inhibitors (2G-TKI), dasatinib and nilotinib, for treatment of chronic myelogenous leukemia, while taking into account frequencies of genetic mutations that exhibit different sensitivities to the 2G-TKIs.

Methods:

Frequencies of BCR-ABL1 mutations and the impact of mutations on responses to 2G-TKIs were obtained from published literature and used as inputs in a decision analytics model. Complete hematologic response (CHR) and major cytogenetic response (MCyR) were estimated after 12 months of 2G-TKI treatment. Total annual 2G-TKI drug costs per CHR and MCyR were estimated and compared among 3 2G-TKI access scenarios: (1) open access to both 2G-TKIs; (2) access restricted to dasatinib (DASA-only); and (3) access restricted to nilotinib (NILO-only).

Results:

Among a hypothetical cohort of 1000 2G-TKI-treated chronic myelogenous leukemia patients, the percentage of patients with CHR and MCyR were greatest for the open access plan (CHR: 93%, MCyR: 56%), followed by DASA-only (88%, 53%) and NILO-only (67%, 47%). Compared with the 2G-TKI costs per CHR in open access ($120,706/CHR), the costs were 5% higher ($126,753/CHR) in DASA-only and 41% higher ($169,990/CHR) in NILO-only. Likewise, compared with the 2G-TKI costs per MCyR in open access ($198,284/MCyR), the costs were 6% higher ($209,259/MCyR) in DASA-only and 22% higher ($241,515/MCyR) in NILO-only.

Conclusion:

Open access to both 2G-TKIs is associated with improved clinical and economic outcomes: greater treatment response rates (CHR and MCyR) and lower drug costs compared with restricted access to 2G-TKIs.
The Application of the CRASH-CT Prognostic Model for Older Adults With Traumatic Brain Injury: A Population-Based Observational Cohort Study
Authors: Staples John A. , Wang Jin , Mills Brianna , Temkin Nancy , Zaros Mark C. , Jurkovich Gregory J. , Rivara Frederick P.
Published: November 2015

Objective:

To examine the performance of the Corticosteroid Randomization After Significant Head injury (CRASH) trial prognostic model in older patients with traumatic brain injury.

Setting:

The National Study on Costs and Outcomes of Trauma cohort, established at 69 hospitals in the United States in 2001 and 2002.

Participants:

Adults with traumatic brain injury and an initial Glasgow Coma Scale score of 14 or less.

Design:

The CRASH-CT model predicting death within 14 days was deployed in all patients. Model performance in older patients (aged 65-84 years) was compared with that in younger patients (aged 18-64 years).

Main Measures:

Model discrimination (as defined by the c-statistic) and calibration (as defined by the Hosmer-Lemeshow P value).

Results:

CRASH-CT model discrimination was not significantly different between the older (n = 356; weighted n = 524) and younger patients (n = 981; weighted n = 2602) and was generally adequate (c-statistic 0.83 vs 0.87, respectively; P = .11). CRASH-CT model calibration was adequate for the older patients and inadequate for younger patients (Hosmer-Lemeshow P values .12 and .001, respectively), possibly reflecting differences in sample size. Calibration-in-the-large showed no systematic under- or overprediction in either stratum.

Conclusion:

The CRASH-CT model may be valid for use in a geriatric population.
Feasibility of a Cognitive Behavioral Intervention to Manage Fatigue in Individuals With Traumatic Brain Injury: A Pilot Study
Authors: Raina Ketki D. , Morse Jennifer Q. , Chisholm Denise , Leibold Mary Lou , Shen Jennifer , Whyte Ellen
Published: November 2015

Objective:

To evaluate the feasibility of conducting a randomized clinical trial of an Internet-based manualized intervention to teach individuals with traumatic brain injury to manage their fatigue.

Setting:

Community dwelling.

Participants:

Forty-one participants randomized to Maximizing Energy (MAX) intervention group (n = 20) and Health Education group (n = 21).

Intervention:

The experimental group (MAX intervention) received an 8-week program that combined education and Problem-Solving Therapy to teach individuals to manage fatigue-related problems. The attention control group received health education.

Measures:

Primary outcome measures pertained to the feasibility of conducting the trial. Secondary outcomes were fatigue impact and fatigue severity assessed at baseline and postintervention.

Results:

Of the 65 participants referred, 41 were enrolled (63% recruitment rate), of which 3 withdrew (92% retention rate). Participants in the experimental and control groups completed their homework 75% and 85% of the time, respectively, and were equally engaged in the sessions. Participants in the experimental group were able to learn and implement the MAX intervention steps. Effect sizes for all measures ranged from small (−0.17) to medium (−0.58) in favor of the intervention group.

Conclusion:

Findings from the study suggest that the MAX intervention is feasible to administer to individuals with post–traumatic brain injury fatigue.
The Nature and Clinical Significance of Preinjury Recall Bias Following Mild Traumatic Brain Injury
Authors: Silverberg Noah D. , Iverson Grant L. , Brubacher Jeffrey R. , Holland Elizabeth , Hoshino Lisa Casagrande , Aquino Angela , Lange Rael T.
Published: November 2015

Objective:

Patients with mild traumatic brain injury (MTBI) often underestimate their preinjury symptoms. This study aimed to clarify the mechanism underlying this recall bias and its contribution to MTBI outcome.

Setting:

Level I trauma center.

Participants:

Patients with uncomplicated MTBI (N = 88) and orthopedic injury (N = 67).

Design:

Prospective longitudinal.

Main Measures:

Current and retrospective ratings on the British Columbia Postconcussion Symptom Inventory, completed at 6 weeks and 1 year postinjury.

Results:

Preinjury symptom reporting was comparable across groups, static across time, and associated with compensation-seeking. High preinjury symptom reporting was related to high postinjury symptom reporting in the orthopedic injury group but less so in the MTBI group, indicating a stronger positive recall bias in highly symptomatic MTBI patients. Low preinjury symptom reporting was not a risk factor for poor MTBI outcome.

Conclusion:

The recall bias was stronger and more likely clinically significant in MTBI patients with high postinjury symptoms. Multiple mechanisms appear to contribute to recall bias after MTBI, including the reattribution of preexisting symptoms to MTBI as well as processes that are not specific to MTBI (eg, related to compensation-seeking).