bluuebunny/crossref_metadata_2025 huggingface dataset:
The thermoelastic bending and thermal diffusion processes influence on photoacoustic signal generation using open photoacoustic cell technique
Authors: Somer A. , Camilotti F. , Costa G. F. , Bonardi C. , Novatski A. , Andrade A. V. C. , Kozlowski V. A. , Cruz G. K.
Published: August 2013

Thermal diffusion and thermoelastic bending are two consequences of heating generated on the sample surface. Both are employed in Open Photoacoustic Cell (OPC) technique to measure the thermal diffusivity of the sample. In this work, we explore the potential use of the OPC technique to study the effectiveness of thermoelastic bending process and thermal diffusion process on photoacoustic signal (S) generation in solids. More specifically, it is observed that if the thermoelastic bending process becomes more effective while the sample thickness is decreased, this information can be used to obtain a method to self-check the value of the thermal diffusivity parameter measured. The method is based on the measurement of the thermoelastic bending parameter as a function of the sample thickness (ls). The expected dependence of the thermoelastic bending parameter (C2) with the sample thickness, according to the theoretical model, is C2 ∝ ls−3. Our results for aluminum metallic samples give a C2 ∝ ls−2.8 dependence. Also, a thermal diffusivity value of αexp = (8.4 ± 0.3) × 10−5 m2/s was measured for metallic aluminum. This value is in good agreement when compared with the theoretical value αAl = 8.6 × 10−5 m2/s.
Contact resonance force microscopy for nanomechanical characterization: Accuracy and sensitivity
Authors: Zhou Xilong , Fu Ji , Li Faxin
Published: August 2013

Contact Resonance Force Microscopy (CRFM), based on dynamic force microscopy, is a new promising technique for quantitative nanoscale mechanical characterization of various materials. In this work, we systematically investigated the measurement accuracy and sensitivity of CRFM both experimentally and numerically. For the accuracy study, we first evaluated the validity of the Euler-Bernoulli beam model used in CRFM and found that it is accurate enough for practical testing. Then, the influence of the tip location was also analyzed and results show that it can significantly affect the obtained indentation modulus. The measurement accuracy of CRFM was then compared with that of nanoindentation and it shows that CRFM has less relative testing errors than nanoindentation for modulus mapping but a larger data scattering for single-point measurements. As to the sensitivity study, we first conducted the cantilever-stiffness dependent sensitivity analysis using both numerical and experimental approaches, and suggested that a stiffer cantilever (say 30-50 N/m) is required for characterization of hard materials (say modulus larger than 30 GPa). Then, the sensitivity of different flexural modes of a specific cantilever was tested and it is found that higher flexural modes could provide higher sensitivity especially, when the normalized contact stiffness is large. Finally, the effect of laser spot location on the detecting sensitivity was tested and the optimal location is suggested. This work could provide very helpful guidance to nanoscale mechanical characterization using CRFM.
Effect of intermartensite transformation on twinning stress in Ni-Mn-Ga 10 M martensite
Authors: Straka L. , Sozinov A. , Drahokoupil J. , Kopecký V. , Hänninen H. , Heczko O.
Published: August 2013

Intermartensite transformations (IMTs) and temperature dependence of very low twinning stress associated with Type II twin boundaries were studied experimentally in four magnetic shape memory alloys with composition Ni50Mn25 + xGa25 – x (at. %), where x was between 3.2 and 3.9. The slightly different x or Mn content resulted in slightly different martensite transformation temperatures between 309 and 328 K, but in significantly different intermartensite transformation temperatures between 10 K and 251 K, with the transformation temperature being approximately proportional to x. In all four alloys, the initial twinning stress, about 0.1 MPa at room temperature, increases sharply when approaching the IMT at lower temperatures, up to 1 MPa and more. The effect is explained by the instability of 10M martensite near the IMT from which it follows that the twinning stress dependence shall be flat for x≤2.7. That is experimentally confirmed by an additional measurement on Ni50Mn27.7Ga22.3 alloy (x = 2.7), which exhibits just slowly increasing twinning stress with decreasing temperature, with the maximum of only 0.2 MPa at 1.7 K.
Tuning electromechanical resonances in strip-ring magnetoelectric composites structure with dc magnetic field
Authors: Wei Wang , XiaoXiao Xu , LiSheng Zhou , Xiao Bin Luo , Ning Zhang
Published: August 2013

In this paper, we show that electrically excited mechanical resonances can be tuned with a single dc magnetic field in strip-ring magnetoelectric composites, namely, ferrite-lead zirconate titanate (PZT) and nickel-zinc (Ni-Zn) ferrite. A theoretical model is presented to describe the magnetically tuned electromechanical resonances in the piezoelectric-magnetostrictive heterostructure, where the piezoelectric and magnetostrictive phases are coupled through normal stresses instead of shear stresses, which usually act in layered composites. As we have used only dc magnetic field that tuned electromechanical resonances, the adjustment manner can simplify application in transducers for magnetoelectric energy conversion.
Structure of conducting channel of lightning
Authors: Alanakyan Yu. R.
Published: August 2013

The spatial distribution of the plasma density in a lightning channel is studied theoretically. It is shown that the electric-field double layer is formed at the channel boundary. In this case, the electron temperature changes abruptly and ions are accelerated by the electric field of the double layer. The ion momentum flux density is close to the surrounding gas pressure. Cleaning of the channel from heavy particles occurs in particle-exchange processes between the plasma channel and the surrounding air. Hydrogen ions are accumulated inside the expanding channel from the surrounding air, which is enriched by hydrogen-contained molecules. In this case, the plasma channel is unstable and splits to a chain of equidistant bunches of plasma. The hydrogen-enrich bunches burn diffusely after recombination exhibiting the bead lightning behavior.
Hall thruster plasma fluctuations identified as the E×B electron drift instability: Modeling and fitting on experimental data
Authors: Cavalier J. , Lemoine N. , Bonhomme G. , Tsikata S. , Honoré C. , Grésillon D.
Published: August 2013

Microturbulence has been implicated in anomalous transport at the exit of the Hall thruster, and recent simulations have shown the presence of an azimuthal wave which is believed to contribute to the electron axial mobility. In this paper, the 3D dispersion relation of this E×B electron drift instability is numerically solved. The mode is found to resemble an ion acoustic mode for low values of the magnetic field, as long as a non-vanishing component of the wave vector along the magnetic field is considered, and as long as the drift velocity is small compared to the electron thermal velocity. In these conditions, an analytical model of the dispersion relation for the instability is obtained and is shown to adequately describe the mode obtained numerically. This model is then fitted on the experimental dispersion relation obtained from the plasma of a Hall thruster by the collective light scattering diagnostic. The observed frequency-wave vector dependences are found to be similar to the dispersion relation of linear theory, and the fit provides a non-invasive measurement of the electron temperature and density.
High resolution scanning tunnelling microscopy and extended x-ray-absorption fine structure study of the (5 × 3) silicide structure on Cu(001)
Authors: Lalmi B. , Chorro M. , Belkhou R.
Published: August 2013

Using low energy electron diffraction (LEED), scanning tunnelling microscopy (STM), and x-ray absorption spectroscopy (XAS) techniques, we have studied the first steps of silicon adsorption onto Cu (001) single crystal substrate. For low coverage (∼0.5 ML) and after annealing at 100 °C, STM images and LEED patterns reveal the formation of an ordered quasi commensurate (5×3) superstructure. From a quantitative analysis of XAS data, we extract the Si-Cu distance and detail the local atomic arrangement of the (5×3) structure.
Erratum: “Heating and flooding: A unified approach for rapid generation of free energy surfaces” [J. Chem. Phys. 137, 024102 (2012)]
Authors: Chen Ming , Cuendet Michel A. , Tuckerman Mark E.
Published: August 2013

We correct an error in our original paper. Calculations originally reported for the alanine tripeptide were performed using the earlier driven adiabatic free energy dynamics (d-AFED) approach rather than the new unified free energy dynamics (UFED) scheme. When UFED is applied to this system, the rate of convergence of the free energy surface improves significantly over that originally reported for d-AFED.
Optimization of photovoltaics panels area at Serbian zero-net energy building
Authors: Nikolić Danijela , Djordjević Zorica , Bojic Milorad , Radulović Jasna , Skerlić Jasmina
Published: August 2013

In this study, the possibilities to decrease energy consumption of a residential building in Serbian conditions are analyzed. The building uses electricity for space heating system, heating of domestic hot water, lighting, and for other electric equipment. The electrical energy is generated by photovoltaics (PV) system and it may be consumed by the building or may be fed-in to the electricity grid. The major aim of the optimization of PV area is to determine the avoided electricity from the grid (avoided exergy), and to minimize the consumption of primary energy. The residential buildings with variable thermal insulation thickness, hot water consumption, life time, and PV's embodied energy are investigated, in order to achieve zero-net energy building or positive-net energy building. The buildings are presented by a mathematical model, in EnergyPlus environment. Open Studio plug-in in Google SketchUp was used for building virtual design, Hooke-Jeeves algorithm for optimization, and GENOPT software for software execution control. For the different areas of photovoltaics, the investigations gave the results for their optimal values. In that way, the fossil energy consumption and CO2 emission are also minimized.
Sharp variation in coercivity and magnetic interactions in patterned CoxNi1−x nanoarrays
Authors: Yang Chao-Yao , Wang Liang-Wei , Chen Po-An , Lin Hong-Ji , Lai Chih-Huang , Tseng Yuan-Chieh
Published: August 2013

We present a study concerning the unexpectedly large coercivity increase and associated magneto-structural properties of CoxNi1−x patterned arrays. An increase in x led to an face-center-cubic (FCC)→hexagonal-close-packed (HCP) transition in CoxNi1−x arrays, accompanied by a 6-fold increase in coercivity and strong 3d exchange interactions probed by x-ray magnetic circular dichroism. Sum-rule analysis revealed that orbital moment involved very little in the variable coercivity and magnetic anisotropy; this is distinct from other nanostructures displaying variable coercivity. The sharp rise in coercivity can be attributed to the geometrical confinement of the arrays, causing the microstructure of the nano-clusters to switch magnetization reversal mechanism from fanning to coherent with increasing x, based on the chain-of-spheres model. First-order-reversal curves revealed that the FCC and HCP arrays comprised both soft and hard ferromagnetic components; however, the soft component of the FCC was much more pronounced, leading to differences in reversibility. This type of nanostructure provides a sharp control of magnetic hardness that could be tailored in related technologies.
TiO2 nanotube arrays via electrochemical anodic oxidation: Prospective electrode for sensing phenyl hydrazine
Authors: Ameen Sadia , Shaheer Akhtar M. , Seo Hyung-Kee , Shin Hyung-Shik
Published: August 2013

The TiO2 nanotube (NT) arrays were grown on Ti foil substrate by electrochemical anodic oxidation and utilized as working electrode to fabricate a highly sensitive and reproducible chemical sensor for the detection of harmful phenyl hydrazine chemical. The fabricated chemical sensor based on TiO2 NT arrays electrode exhibited high sensitivity of ∼40.9μA mM−1 cm−2 and detection limit of ∼0.22 μM with short response time (10 s). The enhanced sensing properties were attributed to the presence of depleted oxygen layer on the surface of grown TiO2 NT arrays and its high electron transfer process via good electrocatalytic activity towards phenyl hydrazine chemical.
Superhydrophobic copper mesh films with rapid oil/water separation properties by electrochemical deposition inspired from butterfly wing
Authors: Wang Ben , Guo Zhiguang
Published: August 2013

Inspired from butterfly wing, superhydrophobic copper mesh films were fabricated via a facile and environmental friendly method by electroplating Cu nanoparticles on the as-cleaned copper mesh films and followed by a thiol grafting. As-fabricated hierarchical structured copper mesh film showed efficient and rapid oil/water separation ability and could be repeatedly used for numerous times. The key parameters of the fabrication of suitable surface morphologies, including the electroplating time, current, electrolyte temperature, and electrolyte concentration, were particularly studied. The stability of as-prepared copper mesh film was also evaluated by compression, thermal, and ultrasonic tests.
Quantitative analysis of strain distribution in InAs/InAs1−xSbx superlattices
Authors: Mahalingam Krishnamurthy , Steenbergen Elizabeth H. , Brown Gail J. , Zhang Yong-Hang
Published: August 2013

Atomic resolution transmission electron microscopy is performed to examine the strain distribution in an InAs/InAs1−xSbx superlattice grown on a (100)-GaSb substrate. The strain profiles reveal that the thickness of tensile regions in the superlattice is significantly lower than expected, with a corresponding increase in thickness of the compressive regions. Furthermore, significant grading is observed within the tensile regions of the strain profile, indicating Sb intermixing from the InAsSb growth surface. The results signify an effective reduction in the InAs layer thickness due to the anion (As-Sb) exchange process at the InAs-on-InAsSb interface.
Tuning negative thermal expansion in Bi1−x
LnxNiO3 (Ln = La, Nd, Eu, Dy)
Authors: Oka Kengo , Nabetani Koichiro , Sakaguchi Chika , Seki Hayato , Czapski Michal , Shimakawa Yuichi , Azuma Masaki
Published: August 2013

The compositional dependence of the negative thermal expansion (NTE) property of Bi1−xLnxNiO3 (Ln = La, Nd, Eu, Dy) was investigated. All x = 0.05 samples showed large NTE over αL = −70 ppm/K (αL: coefficient of linear thermal expansion) due to intermetallic charge transfer between Bi5+ and Ni2+. The temperature range of NTE shifted upward with decreasing ionic radius of Ln3+. Partial ordering of Bi/Ln is suggested to be the origin of this shift and the suppression of the broadening of the transition.
Dynamical spin reorientation transition in NdFeO3 single crystal observed with polarized terahertz time domain spectroscopy
Authors: Jiang Junjie , Jin Zuanming , Song Gaibei , Lin Xian , Ma Guohong , Cao Shixun
Published: August 2013

Temperature-induced spin reorientation transition in NdFeO3 single crystal is studied by terahertz time-domain spectroscopy in the temperature range from 50 K to 290 K. Following the resonant excitation of quasi-antiferromagnetic (AF) mode, the nature of temperature dependence of emission from AF-mode is investigated systematically in the spin reorientation temperature interval. The emission frequency is observed at 0.485 THz for both Γ4 and Γ24 phases, and it shifts abruptly to 0.456 THz (around 110 K) corresponding to Γ2 phase. The evolution of vector G is obtained from the temperature-dependent polarization changes of the AF-mode excitation. Our results demonstrate that the polarized terahertz time-domain spectroscopy is a sensitive tool to explore the dynamical spin reorientation transition in RFeO3 crystals, and the terahertz magnetic pulse shows potential application for non-thermally manipulating ultrafast spin reorientation.
Memory effect and triplet pairing generation in the superconducting exchange biased Co/CoOx/Cu41Ni59/Nb/Cu41Ni59 layered heterostructure
Authors: Zdravkov V. I. , Lenk D. , Morari R. , Ullrich A. , Obermeier G. , Müller C. , Krug von Nidda H.-A. , Sidorenko A. S. , Horn S. , Tidecks R. , Tagirov L. R.
Published: August 2013

We fabricated a nanolayered hybrid superconductor-ferromagnet spin-valve structure, the resistive state of which depends on the preceding magnetic field polarity. The effect is based on a strong exchange bias (about −2 kOe) on a diluted ferromagnetic copper-nickel alloy and generation of a long range odd in frequency triplet pairing component. The difference of high and low resistance states at zero magnetic field is 90% of the normal state resistance for a transport current of 250 μA and still around 42% for 10 μA. Both logic states of the structure do not require biasing fields or currents in the idle mode.
ZrO2 dielectric-based low-voltage organic thin-film inverters
Authors: Oh Jeong-Do , Seo Hoon-Seok , Shin Eun-Sol , Kim Dae-Kyu , Ha Young-Geun , Choi Jong-Ho
Published: August 2013

In this paper, the authors first report ZrO2-dielectric based low-voltage organic thin-film complementary metal-oxide semiconductor inverters. Two active layers of p-type pentacene and n-type N,N′-dioctyl-3,4,9,10-perylenedicarboximide were successively deposited on the thermally stable, transparent ZrO2 using the neutral cluster beam deposition method. Based on the good balance between p- and n-type transistors, the complementary inverters exhibited ideal characteristics including sharp inversions, complete switching, high gains, and large voltage swings at low operating voltage levels.
Solidification and crystal growth of highly compressed hydrogen and deuterium: Time-resolved study under ramp compression in dynamic-diamond anvil cell
Authors: Tomasino Dane , Yoo Choong-Shik
Published: August 2013

Solidification of hydrogen and deuterium has been studied under dynamic compression using dynamic-diamond anvil cell, time-resolved Raman spectroscopy, and fast micro-photography. Liquid H2 or D2 solidifies into a grain boundary free crystal grown from the outer edge of the sample chamber in 1–30 ms depending on the compression rate. The time scale of solidification agrees well with that of the discontinuous Raman shift across the liquid/solid phase boundary, underscoring a compression rate dependence of the solidification process. The crystal growth rates were measured to be 0.12–0.80 cm/s for H2 and 0.13–1.27 cm/s for D2, varying linearly with the compression rate.
High-throughput inertial particle focusing in a curved microchannel: Insights into the flow-rate regulation mechanism and process model
Authors: Xiang Nan , Yi Hong , Chen Ke , Sun Dongke , Jiang Di , Dai Qing , Ni Zhonghua
Published: August 2013

In this work, we design and fabricate a miniaturized spiral-shaped microchannel device which can be used for high-throughput particle/cell ordering, enrichment, and purification. To probe into the flow rate regulation mechanism, an experimental investigation is carried out on the focusing behaviors of particles with significantly different sizes in this device. A complete picture of the focusing position shifting process is unfolded to clarify the confusing results obtained from flow regimes with different dominant forces in past research. Specifically, with the increase of the flow rate, particles are observed to first move towards the inner wall under the dominant inertial migration, then stabilize at a specific position and finally shift away from the inner wall due to the alternation of the dominant force. Novel phenomena of focusing instability, co-focusing, and focusing position interchange of differently sized particles are also observed and investigated. Based on the obtained experimental data, we develop and validate, for the first time, a five-stage model of the particle focusing process with increasing flow rate for interpreting particle behaviors in terms of the competition between inertial lift and Dean drag forces. These new experimental findings and the proposed process model provide an important supplement to the existing mechanism of inertial particle flow and enable more flexible and precise particle manipulation. Additionally, we examine the focusing behaviors of bioparticles with a polydisperse size distribution to validate the explored mechanisms and thus help realize efficient enrichment and purification of these particles.
How is Space Public? Implications for Spatial Policy and Democracy
Authors: Parkinson John R
Published: August 2013

Battles over public space involve conflicts of values that express themselves in planning policies as well as the built environment. However, the dominant conceptions of public space in planning practice and the academic literature support a limited range of those values. I argue that conceptions based on openness and accessibility play into a particular construction of public life that emphasises casual interactions and downplays purposive, political ones. Following a conceptual analysis of the public–private distinction, the paper offers a novel, threefold account of public space; argues that democracy requires a particular kind of publicness not recognised by the commonly accepted definition; and deploys a simple content analysis to highlight the conceptual emphases and absences in planning policy in the political heart of London. I argue that some advocates of public space are unwittingly supporting restrictive planning and design practices that limit important kinds of democratic expression.
Environmental Responsibility in a Transition Context: Russian NGO Perception and Response
Authors: Crotty Jo , Hall Sarah Marie
Published: August 2013

In this paper we examine the issue of environmental responsibility in the Russian Federation by engaging in responsibility narratives with environmental nongovernmental organisations (NGOs). We do so to examine in more depth the impact of the deinstitutionalisation of environmental responsibility in Russia throughout the transition period. We find that while NGOs regard the state and other key actors to have abdicated in their responsibility for protecting the natural environment, Russian environmental NGOs appear unable to substitute for these actors. Consequently, the Russian environment remains largely unprotected and thus subject to continuing irresponsibility in the field of environmental protection and pollution control.
Social Enterprise and Ethnic Minorities: Exploring the Consequences of the Evolving British Policy Agenda
Authors: Sepulveda Leandro , Syrett Stephen , Calvo Sara
Published: August 2013

Recent years have seen successive British governments move social enterprise centre stage as a policy construct. Yet there remains little understanding as to whether this policy direction provides new opportunities for engagement for migrant and ethnic minority groups or acts to reinforce past processes of exclusion. We address this issue by examining the nature and extent of migrant and ethnic minorities' involvement in social enterprise activity and the resulting implications for policy and practice. Through original empirical analysis of ethnic minority third sector organisations in East London, results are presented in relation to the challenges of defining and measuring this arena of activity, the nature of the current transition towards social enterprise forms, and the extent of engagement in the policy process. We conclude that the narrow arena of action for social enterprise activity as promoted within the current policy discourse provides little scope for engagement for the majority of small-scale ethnic minority organisations.
Dumping Ground or Country-in-Transition? Discourses of E-Waste in South Africa
Authors: Lawhon Mary
Published: August 2013

Electronic waste (e-waste) has become a point of interest for social and technical scientists, activists, and policy makers. In South Africa researchers, consultants, and industry have worked together to develop plans for modernizing the e-waste industry while, at the same time, a group of activists connected to the global environmental justice movement is concerned with the illegal import of e-waste into South Africa. In this paper I show how the discourses of ecological modernization and environmental justice have been mobilized by these two different groups. The discourses have contrasting evaluations of the role of technology, relationship with the state, and the role of political economy which shape interactions between the discourses and discourse coalitions. Despite these differences, productive engagements exist. I suggest that understanding these differences can improve this engagement and contribute to more successful e-waste policy and management in the South African context and more widely.
Pork-Barrel versus Irrelevance Effects in Portuguese Public Spending
Authors: Mourao Paulo Reis
Published: August 2013

Pork-barrel effects are discussed using a specific program of Portuguese investment expenditures (PIDDAC) that has been observed since 1997. My framework adds new insight to this important branch of economics literature. First, my analysis is the first to be based on sequential dictators games, which are more appropriate for studying the strategies of the agents involved in pork-barrel practices. Second, I examine the role of ‘irrelevance effects’, which limit or offset the pork-barrel effect even if the recipient municipality and the Portuguese government are ruled by the same political wing. My empirical estimations confirm that the Portuguese government tends to increase PIDDAC transfers to the municipalities that are being ruled by the same political wing. Municipalities with fewer residents or fewer parishes tend to suffer the most significant irrelevance effects. PIDDAC transfers to all municipalities were found to be more generous during election years.
The Artist's Advantage: Better Integration of Object Information across Eye Movements
Authors: Perdreau Florian , Cavanagh Patrick
Published: August 2013

Over their careers, figurative artists spend thousands of hours analyzing objects and scene layout. We examined what impact this extensive training has on the ability to encode complex scenes, comparing participants with a wide range of training and drawing skills on a possible versus impossible objects task. We used a gaze-contingent display to control the amount of information the participants could sample on each fixation either from central or peripheral visual field. Test objects were displayed and participants reported, as quickly as possible, whether the object was structurally possible or not. Our results show that when viewing the image through a small central window, performance improved with the years of training, and to a lesser extent with the level of skill. This suggests that the extensive training itself confers an advantage for integrating object structure into more robust object descriptions.
Perceived Gesture Dynamics in Nonverbal Expression of Emotion
Authors: Dael Nele , Goudbeek Martijn , Scherer K R
Published: August 2013

Recent judgment studies have shown that people are able to fairly correctly attribute emotional states to others' bodily expressions. It is, however, not clear which movement qualities are salient, and how this applies to emotional gesture during speech-based interaction. In this study we investigated how the expression of emotions that vary on three major emotion dimensions—that is, arousal, valence, and potency—affects the perception of dynamic arm gestures. Ten professional actors enacted 12 emotions in a scenario-based social interaction setting. Participants (N = 43) rated all emotional expressions with muted sound and blurred faces on six spatiotemporal characteristics of gestural arm movement that were found to be related to emotion in previous research (amount of movement, movement speed, force, fluency, size, and height/vertical position). Arousal and potency were found to be strong determinants of the perception of gestural dynamics, whereas the differences between positive or negative emotions were less pronounced. These results confirm the importance of arm movement in communicating major emotion dimensions and show that gesture forms an integrated part of multimodal nonverbal emotion communication.
Selectively Enhanced Motion Perception in Core Video Gamers
Authors: Hutchinson Claire V , Stocks Rachel
Published: August 2013

In this study we examined the effects of action video game play on performance for encoding global motion. There were no significant differences between video game player (VGP) and non-video game player (NVGP) performance for either translational or rotational motion. For radial motion, VGPs were significantly better than NVGPs at discriminating contracting, but not expanding, elements. We postulate that VGPs are selectively sensitive to radial contractions because, while this type of optic flow information is abundant in action video games, it is not encountered in abundance in the real world.
MHC class I molecules are preferentially ubiquitinated on endoplasmic reticulum luminal residues during HRD1 ubiquitin E3 ligase-mediated dislocation
Authors: Burr Marian L. , van den Boomen Dick J. H. , Bye Helen , Antrobus Robin , Wiertz Emmanuel J. , Lehner Paul J.
Published: August 2013

Misfolded MHC class I heavy chains (MHC I HCs) are targeted for endoplasmic reticulum (ER)-associated degradation (ERAD) by the ubiquitin E3 ligase HRD1, and E2 ubiquitin conjugating enzyme UBE2J1, and represent one of the few known endogenous ERAD substrates. The mechanism by which misfolded proteins are dislocated across the ER membrane into the cytosol is unclear. Here, we investigate the requirements for MHC I ubiquitination and degradation and show that endogenous misfolded MHC I HCs are recognized in the ER lumen by EDEM1 in a glycan-dependent manner and targeted to the core SEL1L/HRD1/UBE2J1 complex. A soluble MHC I HC lacking its transmembrane domain and cytosolic tail uses the same ERAD components and is degraded as efficiently as wild-type MHC I. Unexpectedly, HRD1-dependent polyubiquitination is preferentially targeted to the ER luminal domain of full-length MHC I HCs, despite the presence of an exposed cytosolic C-terminal tail. MHC I luminal domain ubiquitination occurs before p97 ATPase-mediated extraction from the ER membrane and can be targeted to nonlysine, as well as lysine, residues. A subset of integral membrane proteins, therefore, requires an early dislocation event to expose part of their luminal domain to the cytosol, before HRD1-mediated polyubiquitination and dislocation.
She’ll Settle It?
Authors: Boyd Christina L.
Published: August 2013

Relying on research that posits that female leaders and managers will be more likely than men to adopt a management style that favors participation, collaboration, and consensus building, I argue that female district court judges, using this style in their case management environments, should be more likely than their male colleagues to successfully foster intracourt case settlements. To test this, I compile data from nearly 18,000 civil rights and tort cases terminated in four federal district courts across 9 years. The regression and duration analyses provide confirmation that the sex of a case’s assigned judge matters, with female judges successfully fostering settlement in their cases more often and more quickly than their male colleagues. In addition to having significance for litigants, these findings have broad implications for female decision makers across different institutions and organizations as well as the future of the judging profession and diversity appointments to the judiciary.
Diversity, Deliberation, and Judicial Opinion Writing
Authors: Haire Susan B. , Moyer Laura P. , Treier Shawn
Published: August 2013

Underlying scholarly interest in diversity is the premise that a representative body contributes to robust decision-making processes. Using an innovative measure of opinion content, we examine this premise by analyzing deliberative outputs in the US courts of appeals (1997–2002). While the presence of a single female or minority did not affect the attention to issues in the majority opinion, panels composed of a majority of women or minorities produced opinions with significantly more points of law compared to panels with three Caucasian males.
Arguing Gunwall
Authors: Price Richard S.
Published: August 2013

Exploring legal development requires more than simply examining the votes of judges because legal development embraces the actions of multiple actors. At a minimum, courts require lawyers to develop and present cases to them for adjudication. While courts need lawyers, lawyers need law; in other words, courts rely on lawyers to develop cases for their review, but the law provided by those courts shapes the actions of lawyers. This article examines the development of state constitutional law by exploring the interactions between lawyers and the Washington Supreme Court after the court required specific briefing practices for state constitutional arguments and the degree to which Washington lawyers responded. Utilizing legal briefs in Washington and some comparative data, I argue that the court was moderately successful at encouraging more thorough constitutional claims. This highlights the importance of considering how lawyers respond to court signals not only in the presence or absence of certain legal arguments but also in the content of those arguments.
The Provision of Insurance?
Authors: Epperly Brad
Published: August 2013

Leading explanations of judicial independence argue political competition incentivizes those in power to create independent courts as insurance against uncertain futures. While much work addresses the role competition plays, little analyzes the fundamental assumption that courts provide political insurance. I offer an original hypothesis as to how independent courts provide insurance against post-tenure punishment and test this using data on the post-tenure fate of leaders from 1960 to 2004. Results show independence is associated with significantly higher probabilities of unpunished post-tenure fate. The article builds on and extends existing political insurance explanations and offers the first test of one of their critical assumptions.
Classical operators on weighted Banach spaces of entire functions
Authors: Beltrán María , Bonet José , Fernández Carmen
Published: August 2013

We study the operators of differentiation and of integration and the Hardy operator on weighted Banach spaces of entire functions. We estimate the norm of the operators, study the spectrum, and analyze when they are surjective, power bounded, hypercyclic, and (uniformly) mean ergodic.
Corrigendum to “Integral Equations, Implicit Functions, and Fixed Points”
Authors: Burton T.
Published: August 2013

In the paper of this title in Proc. Amer. Math. Soc. 124 (1996), no. 8, 2383–2390, we defined a large contraction, proved a fixed point theorem based on it, and then used it to extend Krasnoselskii’s fixed point theorem. In that last-mentioned theorem we neglected to add the assumption that the mapping set be closed. In this correction we state the relevant theorems, add the assumption, and explain why it is necessary.
Cutting Carbon, Take Two: A Brief Guide to Federal Electricity‐Sector Climate Policy without Cap‐and‐Trade
Authors: Linn Joshua , Richardson Nathan
Published: August 2013

This paper explores federal policies, other than a carbon price, for reducing emissions from the electric power sector. These policies fall into two major categories: policies that encourage the development of non‐ or low‐emitting energy sources, and regulatory policies under existing legal authority (primarily the Clean Air Act). The paper provides an overview of policy options and a few concrete proposals, along with a summary of insights from economists on their advantages and disadvantages. Economists generally disfavor investment subsidies, but comparing other policy options, including regulatory approaches, technology mandates, and production subsidies, is complex. Excluding existing clean generation from incentive policies is tempting but can lead to perverse outcomes.
A Natural Resource Theory of U.S. Crop Insurance Contract Choice
Authors: Du Xiaodong , Hennessy David A. , Feng Hongli
Published: August 2013

A large variety of subsidized crop insurance products are available to U.S. crop growers. Distinct and perhaps puzzling patterns in the choices of insurance products and coverage levels can be discerned. Where production conditions are better and yields are less risky then (a) higher insurance coverage levels are chosen; and (b) revenue insurance is preferred over yield insurance. Also, (c) the extent of preference for revenue insurance is stronger in more productive areas. Assuming, as many do, that growers seek to maximize subsidy transfers, point (a) can be explained by the interaction between yield technology and natural resource endowments. Points (b) and (c) can be explained by location in conjunction with the “natural hedge” and a contract design bias in how revenue insurance guarantees are computed. Empirical study of Risk Management Agency data on corn, soybean, and wheat yields, and insurance contract choices lend support to our model inferences.
Profit‐Maximizing Land‐Use Revisited: The Testable Implications of Non‐joint Crop Production Under Land Constraint
Authors: Gorddard Russell
Published: August 2013

This article derives new implications for the land allocation and production decisions of profit‐maximizing farm‐firms where production of different crops is non‐joint but subject to a constraint on the total land area. These implications are observable and thus subject to empirical scrutiny. An estimable model of crop production, land allocation, and input‐use decisions is derived that permits joint production and enables the implications of non‐joint but land‐constrained production to be tested. This may improve econometric estimates of cross‐price elasticities of supply by linking models of land use and production decisions, and allowing non‐jointness to be imposed where appropriate.
WebRASP: a server for computing energy scores to assess the accuracy and stability of RNA 3D structures
Authors: Norambuena Tomas , Cares Jorge F. , Capriotti Emidio , Melo Francisco
Published: August 2013

Summary: The understanding of the biological role of RNA molecules has changed. Although it is widely accepted that RNAs play important regulatory roles without necessarily coding for proteins, the functions of many of these non-coding RNAs are unknown. Thus, determining or modeling the 3D structure of RNA molecules as well as assessing their accuracy and stability has become of great importance for characterizing their functional activity. Here, we introduce a new web application, WebRASP, that uses knowledge-based potentials for scoring RNA structures based on distance-dependent pairwise atomic interactions. This web server allows the users to upload a structure in PDB format, select several options to visualize the structure and calculate the energy profile. The server contains online help, tutorials and links to other related resources. We believe this server will be a useful tool for predicting and assessing the quality of RNA 3D structures.

Availability and implementation: The web server is available at http://melolab.org/webrasp. It has been tested on the most popular web browsers and requires Java plugin for Jmol visualization.

Contact:  fmelo@bio.puc.cl
Predation control of zooplankton dynamics: a review of observations and models
Authors: Daewel Ute , Hjøllo Solfrid Sætre , Huret Martin , Ji Rubao , Maar Marie , Niiranen Susa , Travers-Trolet Morgane , Peck Myron A. , van de Wolfshaar Karen E.
Published: August 2013

Daewel, U., Hjøllo, S. S., Huret, M., Ji, R., Maar, M., Niiranen, S., Travers-Trolet, M., Peck, M. A., van de Wolfshaar, K. E. 2014. Predation control of zooplankton dynamics: a review of observations and models. – ICES Journal of Marine Science, 71: 254–271. We performed a literature review to examine to what degree the zooplankton dynamics in different regional marine ecosystems across the Atlantic Ocean is driven by predation mortality and how the latter is addressed in available modelling approaches. In general, we found that predation on zooplankton plays an important role in all the six considered ecosystems, but the impacts are differently strong and occur at different spatial and temporal scales. In ecosystems with extreme environmental conditions (e.g. low temperature, ice cover, large seasonal amplitudes) and low species diversity, the overall impact of top-down processes on zooplankton dynamics is stronger than for ecosystems having moderate environmental conditions and high species diversity. In those ecosystems, predation mortality was found to structure the zooplankton mainly on local spatial and seasonal time scales. Modelling methods used to parameterize zooplankton mortality range from simplified approaches with fixed mortality rates to complex coupled multispecies models. The applicability of a specific method depends on both the observed state of the ecosystem and the spatial and temporal scales considered. Modelling constraints such as parameter uncertainties and computational costs need to be balanced with the ecosystem-specific demand for a consistent, spatial-temporal dynamic implementation of predation mortality on the zooplankton compartment.
TGF-β type II receptor expression in thymic epithelial cells inhibits the development of Hassall’s corpuscles in mice
Authors: Odaka Chikako , Hauri-Hohl Mathias , Takizawa Kazuya , Nishikawa Yomiko , Yano Masashi , Matsumoto Mitsuru , Boyd Richard , Holländer Georg A.
Published: August 2013

Hassall’s corpuscles are concentric clusters of keratinized epithelial cells located within the thymic medulla of humans and guinea pigs but are scant in mouse and rat. They are considered to be the terminally differentiated stages of medullary thymic epithelial cells (mTECs) but the mechanisms of their origin are unclear. We have previously deleted the TGF-β type II receptor (TGFβRII) specifically in mouse TECs and reported that these mice have mitigated thymic involution and exhibit earlier reconstitution post-irradiation. In this study, we analyzed the differentiation of mTECs in the TGFβRII-knockout mice. Interestingly, the TGFβRII-knockout mice display enhanced development of Hassall’s corpuscles. The expression of Aire, stromal-cell-derived factor 1 and thymic stromal lymphopoietin in the thymi of the TGFβRII-knockout mice was similar to that previously reported for the human thymus. In addition, the putative epithelial progenitor markers MTS20 and MTS24 labeled Hassall’s corpuscles in normal mice, but the extent and intensity of this staining were greatly enhanced in Hassall’s corpuscles of the TGFβRII-knockout mice. The phosphorylated forms of ERK and JNK were also found in Hassall’s corpuscles of the TGFβRII-knockout mice. Taken together, we suggest that TGFβRII-mediated signaling in TECs inhibits their development into Hassall’s corpuscles in mice.
Focusing on warm dark matter with lensed high-redshift galaxies
Authors: Pacucci Fabio , Mesinger Andrei , Haiman Zoltán
Published: August 2013

We propose a novel use of high-redshift galaxies, discovered in deep Hubble Space Telescope (HST) fields around strong lensing clusters. These fields probe small comoving volumes (∼103 Mpc3) at high magnification (μ ≳ 10) and can detect otherwise inaccessible ultra-faint galaxies. Even a few galaxies found in such small volumes require a very high number density of collapsed dark matter (DM) haloes. This implies significant primordial power on small scales, allowing these observations to rule out popular alternatives to standard cold dark matter (CDM) models, such as warm dark matter (WDM). In this work, we analytically compute WDM halo mass functions at z = 10, including the effects of both particle free-streaming and residual velocity dispersion. We show that the two z ≈ 10 galaxies already detected by the Cluster Lensing And Supernova survey with Hubble (CLASH) survey are sufficient to constrain the WDM particle mass to mx > 1 (0.9) keV at 68 per cent (95 per cent) confidence limit (for a thermal relic relativistic at decoupling). This limit depends only on the WDM halo mass function and, unlike previous constraints on mx, is independent of any astrophysical modelling. The forthcoming HST Frontier Fields can significantly tighten these constraints.
Xanthomonas Filamentous Hemagglutinin-Like Protein Fha1 Interacts with Pepper Hypersensitive-Induced Reaction Protein CaHIR1 and Functions as a Virulence Factor in Host Plants
Authors: Choi Hyong Woo , Kim Dae Sung , Kim Nak Hyun , Jung Ho Won , Ham Jong Hyun , Hwang Byung Kook
Published: August 2013

Pathogens have evolved a variety of virulence factors to infect host plants successfully. We previously identified the pepper plasma-membrane-resident hypersensitive-induced reaction protein (CaHIR1) as a regulator of plant disease- and immunity-associated cell death. Here, we identified the small filamentous hemagglutinin-like protein (Fha1) of Xanthomonas campestris pv. vesicatoria as an interacting partner of CaHIR1 using yeast two-hybrid screening. Coimmunoprecipitation and bimolecular fluorescence complementation experiments revealed that Fha1 specifically interacts with CaHIR1 in planta. The endocytic tracker FM4-64 staining showed that the CaHIR1-Fha1 complex localizes in the endocytic vesicle-like structure. The X. campestris pv. vesicatoria Δfha1 mutant strain exhibited significantly increased surface adherence but reduced swarming motility. Mutation of fha1 inhibited the growth of X. campestris pv. vesicatoria and X. campestris pv. vesicatoria ΔavrBsT in tomato and pepper leaves, respectively, suggesting that Fha1 acts as a virulence factor in host plants. Transient expression of fha1 and also infiltration with purified Fha1 proteins induced disease-associated cell death response through the interaction with CaHIR1 and suppressed the expression of pathogenesis-related (PR) genes. Silencing of CaHIR1 in pepper significantly reduced ΔavrBsT growth and Fha1-triggered susceptibility cell death. Overexpression of fha1 in Arabidopsis retarded plant growth and triggered disease-associated cell death, resulting in altered disease susceptibility. Taken together, these results suggest that the X. campestris pv. vesicatoria virulence factor Fha1 interacts with CaHIR1, induces susceptibility cell death, and suppresses PR gene expression in host plants.