bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermionic current densities from first principles
Authors: Voss Johannes , Vojvodic Aleksandra , Chou Sharon H. , Howe Roger T. , Bargatin Igor , Abild-Pedersen Frank
Published: May 2013

We present a density functional theory-based method for calculating thermionic emission currents from a cathode into vacuum using a non-equilibrium Green's function approach. It does not require semi-classical approximations or crude simplifications of the electronic structure used in previous methods and thus provides quantitative predictions of thermionic emission for adsorbate-coated surfaces. The obtained results match well with experimental measurements of temperature-dependent current densities. Our approach can thus enable computational design of composite electrode materials.
Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics
Authors: Sheng Lina , Du Guanghua , Guo Jinlong , Wu Ruqun , Song Mingtao , Yuan Youjin , Xiao Guoqing
Published: May 2013

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of 12C6+ with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 μm × 5 μm on target in air. Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.
Energy transfer process between exciton and surface plasmon: Complete transition from Forster to surface energy transfer
Authors: Kumar Arunandan , Tyagi Priyanka , Srivastava Ritu , Mehta D. S. , Kamalasanan M. N.
Published: May 2013

The energy transfer process between surface plasmons and excitons was studied by varying the filling fraction of gold (Au) nano-clusters (NCs) and by placing a spacer of different thickness between Au NC and organic semiconductor layer. The intensity enhancement has occurred for 10%-50% filling fractions and 4-14 nm spacer thicknesses. Energy transfer mechanism was found to switch from Forster type to surface type by increase in filling fraction. Transverse electric field for Au NCs was simulated and we observed that for filling fraction <30%, Au NCs behave like 1-dimensional dipole and for >60%, they behave like 2-dimensional dipoles.
The microphysics and macrophysics of cosmic rays
Authors: Zweibel Ellen G.
Published: May 2013

This review paper commemorates a century of cosmic ray research, with emphasis on the plasma physics aspects. Cosmic rays comprise only ∼10−9 of interstellar particles by number, but collectively their energy density is about equal to that of the thermal particles. They are confined by the Galactic magnetic field and well scattered by small scale magnetic fluctuations, which couple them to the local rest frame of the thermal fluid. Scattering isotropizes the cosmic rays and allows them to exchange momentum and energy with the background medium. I will review a theory for how the fluctuations which scatter the cosmic rays can be generated by the cosmic rays themselves through a microinstability excited by their streaming. A quasilinear treatment of the cosmic ray–wave interaction then leads to a fluid model of cosmic rays with both advection and diffusion by the background medium and momentum and energy deposition by the cosmic rays. This fluid model admits cosmic ray modified shocks, large scale cosmic ray driven instabilities, cosmic ray heating of the thermal gas, and cosmic ray driven galactic winds. If the fluctuations were extrinsic turbulence driven by some other mechanism, the cosmic ray background coupling would be entirely different. Which picture holds depends largely on the nature of turbulence in the background medium.
Reaction of initially distant scalars in a cylinder wake
Authors: Crimaldi John P. , Kawakami Tanaya R.
Published: May 2013

We used analytical and numerical techniques to investigate the effect of a quasi-steady-state laminar wake behind a circular cylinder on the second-order reaction between two initially distant scalars. The scalars are released continuously from locations upstream of the cylinder, and are separated from each other by a lateral distance that initially impedes the reaction. By comparing the laterally integrated reaction evolution for cases with and without the cylinder wake, the direct effect of the wake on reaction enhancement is determined. We compute the reaction for a range of reaction speeds, scalar diffusivities, and scalar release geometries. The presence of the cylinder wake generates significant reaction enhancement for all cases; the ratio of the reaction with and without the cylinder increases with the initial scalar separation distance. We identify the mechanism for the reaction enhancement, and demonstrate that the reaction rate in the cylinder wake can be predicted by a simple analytical model of a stretched scalar interface.
Non-equilibrium pressure control of the height of a large-scale, ground-coupled, rotating fluid column
Authors: Ash R. L. , Zardadkhan I. R.
Published: May 2013

When a ground-coupled, rotating fluid column is modeled incorporating non-equilibrium pressure forces in the Navier-Stokes equations, a new exact solution results. The solution has been obtained in a similar manner to the classical equilibrium solution. Unlike the infinite-height, classical solution, the non-equilibrium pressure solution yields a ground-coupled rotating fluid column of finite height. A viscous, non-equilibrium Rankine vortex velocity distribution, developed previously, was used to demonstrate how the viscous and non-equilibrium pressure gradient forces, arising in the vicinity of the velocity gradient discontinuity that is present in the classical Rankine vortex model, effectively isolate the rotating central fluid column from the outer potential vortex region. Thus, the non-equilibrium region acts to confine and shield the central, rigid-body-like, rotating fluid core, justifying this examination of how such a rotating fluid column can interact with the ground. The resulting non-equilibrium ground-coupled, rotating fluid column solution was employed to estimate the central column heights of three well-documented dust devils, and the central column height predictions were consistent with published dust devil height statistics.
Distribution of spanwise enstrophy in the near wake of three symmetric elongated bluff bodies at high Reynolds number
Authors: Taylor Zachary J. , Kopp Gregory A. , Gurka Roi
Published: May 2013

Three elongated bluff bodies with a chord-to-thickness ratio of seven have been studied experimentally at a Reynolds number based on body thickness of 3 × 104. The defining feature of elongated bluff bodies is the interaction between trailing edge Kármán vortex shedding and leading edge separation-reattachment. We have used particle image velocimetry with different body geometries to investigate this interaction for three distinct cases: (i) small leading edge separation-reattachment length; (ii) large leading edge separation-reattachment length; and (iii) one case in between these bounds. The leading edge separation-reattachment is a significant source of spanwise enstrophy. Thus, changes in the wake enstrophy distribution are of particular interest. We have examined the time-averaged distribution and production of both the turbulent kinetic energy and the spanwise enstrophy in the near wake region utilizing proper orthogonal decomposition on the vorticity field to distinguish between turbulence and the periodic contribution of the trailing edge vortex shedding. A significant increase in the lateral distribution of spanwise enstrophy is observed – exceeding the typical bounds of the near wake – which is due to the leading edge separation-reattachment and the resulting scale of the flow at the trailing edge. As a result, strengthening the leading edge flow, which tends to weaken the trailing edge vortex shedding, may lead to enhanced mixing in the wake.
On infinite-dimensional state spaces
Authors: Fritz Tobias
Published: May 2013

It is well known that the canonical commutation relation [x, p] = i can be realized only on an infinite-dimensional Hilbert space. While any finite set of experimental data can also be explained in terms of a finite-dimensional Hilbert space by approximating the commutation relation, Occam's razor prefers the infinite-dimensional model in which [x, p] = i holds on the nose. This reasoning one will necessarily have to make in any approach which tries to detect the infinite-dimensionality. One drawback of using the canonical commutation relation for this purpose is that it has unclear operational meaning. Here, we identify an operationally well-defined context from which an analogous conclusion can be drawn: if two unitary transformations U, V on a quantum system satisfy the relation V−1U2V = U3, then finite-dimensionality entails the relation UV−1UV = V−1UVU; this implication strongly fails in some infinite-dimensional realizations. This is a result from combinatorial group theory for which we give a new proof. This proof adapts to the consideration of cases where the assumed relation V−1U2V = U3 holds only up to ε and then yields a lower bound on the dimension.
Construction of point processes for classical and quantum gases
Authors: Nehring Benjamin
Published: May 2013

We propose a construction of point processes via the method of cluster expansion. The important role of the class of infinitely divisible point processes is noted. Examples are permanental and determinantal processes as well as the classical Gibbs point processes, where the interaction is given by a stable and regular pair potential.
Note: Thickness determination of freestanding ultra-thin foils using a table top laboratory extreme ultraviolet source
Authors: Braenzel J. , Pratsch C. , Hilz P. , Kreuzer C. , Schnürer M. , Stiel H. , Sandner W.
Published: May 2013

We present a versatile and handy method allowing a thickness determination of freestanding thin plastic foils by its transmission characteristics in the extreme ultraviolet (EUV) spectrum. The method is based on a laser induced plasma source, emitting light in the EUV region, a compact double-mirror EUV monochromator operating at a fixed wavelength of 18.9 nm, and a CCD camera. The measurement delivers transmission values with a standard deviation of ΔT = 0.005 enabling foils thickness characterization with nm-accuracy at a given foil density and stoichiometric composition. Well characterized freestanding ultra-thin foils can be directly implemented in, e.g., high intensity laser matter experiments without further manipulation.
Simulation and experiment of substrate aluminum grain orientation dependent self-ordering in anodic porous alumina
Authors: Cheng Chuan , Ng K. Y. , Aluru N. R. , Ngan A. H. W.
Published: May 2013

Recent experiments have indicated a strong influence of the substrate grain orientation on the self-ordering in anodic porous alumina. Anodic porous alumina with straight pore channels grown in a stable, self-ordered manner is formed on (001) oriented Al grain, while disordered porous pattern is formed on (101) oriented Al grain with tilted pore channels growing in an unstable manner. In this work, numerical simulation of the pore growth process is carried out to understand this phenomenon. The rate-determining step of the oxide growth is assumed to be the Cabrera-Mott barrier at the oxide/electrolyte (o/e) interface, while the substrate is assumed to determine the ratio β between the ionization and oxidation reactions at the metal/oxide (m/o) interface. By numerically solving the electric field inside a growing porous alumina during anodization, the migration rates of the ions and hence the evolution of the o/e and m/o interfaces are computed. The simulated results show that pore growth is more stable when β is higher. A higher β corresponds to more Al ionized and migrating away from the m/o interface rather than being oxidized, and hence a higher retained O:Al ratio in the oxide. Experimentally measured oxygen content in the self-ordered porous alumina on (001) Al is indeed found to be about 3% higher than that in the disordered alumina on (101) Al, in agreement with the theoretical prediction. The results, therefore, suggest that ionization on (001) Al substrate is relatively easier than on (101) Al, and this leads to the more stable growth of the pore channels on (001) Al.
Expanding the longitudinal magnetoimpedance sensor range by direct bias current
Authors: Ipatov M. , Zhukova V. , Zhukov A. , Gonzalez J.
Published: May 2013

We investigated the effects of induced helical anisotropy and application of dc bias current IB on longitudinal magnetoimpedance (MI) in amorphous microwires both separately and together. We demonstrated that when both parameters are present, i.e., a dc bias current IB is applied to the microwire with induced helical anisotropy, the longitudinal MI sensor range can be considerably extended up to the fields considerably higher than its anisotropy field as the slope of MI curve dZ/dHE remains rather high. A highly asymmetric longitudinal MI dependence with a rather high slope at the zero-field point was obtained. Reversing the bias current IB causes reversal of the bias field direction and results in a mirroring of the MI dependence. This gives a possibility to determine both the sign and the magnitude of the external magnetic field. The obtained results can be used in development of the longitudinal MI sensors with increased sensitivity and/or range.
Hydrodynamics of the molten metal in a vacuum arc cathode spot at near-threshold currents
Authors: Mesyats G. A. , Zubarev N. M.
Published: May 2013

The extrusion of the molten metal from a microcrater formed on a metal cathode during the operation of a vacuum arc is considered. The problem is thought to be similar to the classical hydrodynamic problem of a liquid drop impact on a solid surface. Based on this analogy, the conditions are analyzed under which the liquid will change its regular behavior (spreading over the cathode surface) into a singular behavior (formation of microjets and droplets). It is shown that the conditions realized in vacuum arc cathode spots at near-threshold currents are close to the threshold conditions for splashing of the molten metal. This points to a considerable contribution of hydrodynamic processes to the self-sustained operation of a vacuum arc and, in particular, gives grounds to relate the existence of a threshold arc current to the existence of a splashing threshold for liquid metal.
Effective thermal conductivity in thermoelectric materials
Authors: Baranowski Lauryn L. , Jeffrey Snyder G. , Toberer Eric S.
Published: May 2013

Thermoelectric generators (TEGs) are solid state heat engines that generate electricity from a temperature gradient. Optimizing these devices for maximum power production can be difficult due to the many heat transport mechanisms occurring simultaneously within the TEG. In this paper, we develop a model for heat transport in thermoelectric materials in which an “effective thermal conductivity” (κeff) encompasses both the one dimensional steady-state Fourier conduction and the heat generation/consumption due to secondary thermoelectric effects. This model is especially powerful in that the value of κeff does not depend upon the operating conditions of the TEG but rather on the transport properties of the TE materials themselves. We analyze a variety of thermoelectric materials and generator designs using this concept and demonstrate that κeff predicts the heat fluxes within these devices to 5% of the exact value.
Theoretical and experimental characterization of promising new scintillators: Eu2+ doped CsCaCl3 and CsCaI3
Authors: Tyagi Mohit , Zhuravleva M. , Melcher C. L.
Published: May 2013

An integrated approach was used to characterize Eu2+ doped CsCaCl3 and CsCaI3 crystals theoretically and experimentally. The temperature dependence of photoluminescence excitation, emission, and decay time was studied to better understand the energy transport and migration mechanism in these materials. The broadening and redshift of emission with increasing temperature was explained for both crystals by simultaneous quenching of emission and interaction of emission states with lattice vibration. The unusual increase of photoluminescence decay time with increasing temperature was ascribed to the presence of states with a lowered radiative rate slightly above the emitting states. The electronic and optical properties were also calculated theoretically with the help of Density functional theory in order to explain the Eu2+ emission properties in these crystals. The calculation explains the better scintillation light output and proportionality in CsCaI3. The promising cross-luminescent efficiency of these materials is also explained with the help of electronic band structure and dispersion of the partial density of the states of constituent atoms. Despite structural anisotropy, the calculated optical properties of CsCaI3 are nearly isotropic, and therefore the synthesis of optically transparent polycrystalline ceramics may be possible.
Characteristics of ultrafast optical responses originating from non-equilibrium carrier transport in undoped GaAs/n-type GaAs epitaxial structures
Authors: Hasegawa Takayuki , Takagi Yoshihiro , Takeuchi Hideo , Yamada Hisashi , Hata Masahiko , Nakayama Masaaki
Published: May 2013

We have investigated the characteristics of ultrafast optical responses originating from a carrier transport process in undoped GaAs/n-type GaAs (i-GaAs/n-GaAs) epitaxial structures with the use of a reflection-type pump-probe technique at room temperature. The built-in electric field in the i-GaAs top layer, whose strength is controlled by its thickness d, accelerates the transit of photogenerated carriers through the i-GaAs layer. We systematically observed that the decay time of a carrier-induced reflectivity change shortens with an increase in built-in electric field strength resulting from a decrease in d: 6.1, 12, and 28 kV/cm for d = 1200, 500, and 200 nm, respectively. In the i-GaAs/n-GaAs sample with d = 200 nm, which has the highest built-in electric field strength, the decay time is much shorter than the oscillation period of longitudinal optical (LO) phonon. From the spectrally resolved detection of the reflected light, it was found that the energy relaxation of the photogenerated carriers by the LO-phonon scattering hardly occurs in the i-GaAs layer, which indicates a quasiballistic transport. This finding demonstrates that the i-GaAs/n-GaAs structure with the non-equilibrium carrier transport process is useful for ultrafast optical applications.
Surface plasma pretreatment for enhanced diamond nucleation on AlN
Authors: Pobedinskas P. , Degutis G. , Dexters W. , Janssen W. , Janssens S. D. , Conings B. , Ruttens B. , D'Haen J. , Boyen H.-G. , Hardy A. , Van Bael M. K. , Haenen K.
Published: May 2013

The surface of polycrystalline aluminum nitride (AlN) thin films is exposed to different gas discharge plasmas (N2, O2, and CF4) followed by a water-based colloidal seeding of ultra-dispersed nanodiamond particles. Fluorination of the AlN surface enhances the seeding density, whereas the oxidized surface does not yield any nucleation sites. In the former case, the seeding density improves by almost three orders of magnitude as compared to the untreated and N2 pretreated samples, and allows to grow pinhole-free nanocrystalline diamond film on AlN. Finally, we demonstrate a route towards selective diamond growth on AlN thin films by employing CF4 plasma pretreatment together with photolithography.
A methodology for nanosecond (or better) time resolved thermoreflectance imaging with coherence control of laser pulses
Authors: Soni Alok , Sundaram Vijay M. , Wen Sy-Bor
Published: May 2013

A time-domain thermoreflectance imaging methodology with pulsed laser illumination is developed to achieve nanosecond time resolution with diffraction limited spatial resolution. Validation of the proposed methodology through a transient temperature measurement of a micro gold resistor under ∼110 ns pulsed heating is demonstrated, which shows consistency with the corresponding numerical simulation. This approach allows us to determine the transient energy transport in miniature structures, such as microelectronic and nano-photonic devices.
Chemical patterns in translating vortices: Inter- and intra-cellular mixing effects
Authors: Vallatos Antoine , Evans Rhys , Thompson Barnaby W. , Taylor Annette F. , Britton Melanie M.
Published: May 2013

Stationary chemical patterns—flow distributed oscillations (FDOs)—are obtained when the Belousov-Zhabotinsky reaction is coupled with translating vortex flow in a Vortex Flow Reactor. For certain conditions, the FDOs are unstable with the observation of disappearing bands or complex patterns. The transitions between modes of pattern formation are reproduced in a modified Oregonator model consisting of two-zone cells connected in series. We show that increasing inter-cellular mixing of the outer zones results in a transition from FDO to absolute instabilities (AI) and increasing intra-cellular mixing between the core and outer zones can drive the reverse transition between modes (AI to FDO).
Pulsed electron holography
Authors: Germann Matthias , Latychevskaia Tatiana , Escher Conrad , Fink Hans-Werner
Published: May 2013

A technique of pulsed low-energy electron holography is introduced, which allows for recording highly resolved holograms within reduced exposure times. Therefore, stacks of holograms are accumulated in a pulsed mode with individual acquisition times as short as 50 μs. Subsequently, these holograms are aligned and finally superimposed. The resulting holographic record reveals previously latent high-order interference fringes and thereby pushing interference resolution into the sub-nanometer regime. In view of the non-damaging character of low-energy electrons, the method is of particular interest for structural analysis of fragile biomolecules.
Interaction and diffusion of gold nanoparticles in bovine serum albumin solutions
Authors: Kohli Indermeet , Alam Sharmine , Patel Bhavdeep , Mukhopadhyay Ashis
Published: May 2013

We studied the interactions of small sized, radius of 2.5–10 nm, gold nanoparticles (AuNPs) with bovine serum albumin (BSA). Fluctuation correlation spectroscopy (FCS) was used to monitor the changes in the Brownian diffusion of these NPs. Our results indicate a BSA monolayer formation at the NP surface with a thickness of 3.8 nm. The thickness of the adsorbed layer was independent of NP size. Best fit was obtained by the anticooperative binding model with the Hill coefficient of n = 0.63. Dissociation constant (KD) increases with particle size indicating stronger interaction of BSA with smaller sized NPs.
Conical second harmonic generation in one-dimension nonlinear photonic crystal
Authors: An Ning , Zheng Yuanlin , Ren Huaijin , Deng Xuewei , Chen Xianfeng
Published: May 2013

We observed conical second-harmonic generation in a one-dimension anomalous-dispersion-like medium, which manifests itself as scattering-assisted nonlinear interaction via quasi-phase-matching sum frequency process. The parameters for the ring-shaped second harmonic beam are analyzed experimentally and theoretically, which disclose the structure information of the nonlinear photonic crystal and imply potential applications as characterization methods. Furthermore, by varying the angles of incident beam, the conical beam can be significantly enhanced owing to collinear nonlinear coupling between the input beam and the scattering light.
Investigation of the sulfur doping profile in femtosecond-laser processed silicon
Authors: Guenther Kay-Michael , Gimpel Thomas , Kontermann Stefan , Schade Wolfgang
Published: May 2013

In this letter, we demonstrate that silicon can be doped with electrically active sulfur donors beyond the solubility limit of 3 × 1016 cm−3. We investigate the sulfur doping profile at the surface of femtosecond-laser processed silicon with secondary ion mass spectroscopy (SIMS) and capacitance-voltage measurements. SIMS confirms previous observations that the fs-laser process can lead to a sulfur hyperdoping of 5×1019 cm−3 at the surface. Nevertheless, the electrical measurements show that less than 1% of the sulfur is electrically active as a donor.
Evanescent-wave comb spectroscopy of liquids with strongly dispersive optical fiber cavities
Authors: Avino S. , Giorgini A. , Salza M. , Fabian M. , Gagliardi G. , De Natale P.
Published: May 2013

We demonstrate evanescent-wave fiber cavity-enhanced spectroscopy in the liquid phase using a near-infrared frequency comb. Exploiting strong fiber-dispersion effects, we show that liquid absorption spectra can be recorded without any external dispersive element. The fiber cavity is used both as sensor and spectrometer. The resonance modes are frequency locked to the comb teeth while the cavity photon lifetime is measured over 155 nm, from 1515 nm to 1670 nm, where absorption bands of liquid polyamines are detected as a proof of concept. Our fiber spectrometer lends itself to in situ, real-time chemical analysis in environmental monitoring, biomedical assays, and micro-opto-fluidic systems.
Temperature dependence of the interband transition in a V2O5 film
Authors: Kang Manil , Kim Sok Won , Hwang Younghun , Um Youngho , Ryu Ji-Wook
Published: May 2013

The temperature dependence of the interband transition in an α-V2O5 film was investigated using absorption and photoluminescence spectral measurements at a temperature range of 10–300 K. Transmission measurements in the experimental temperature range indicate that the α-V2O5 film has two distinct interband transitions, implying indirect and direct transitions. This result was confirmed by spectroscopic ellipsometry. The blue shift of both the transitions in the α-V2O5 film with decreasing temperature was explained by a reduction in the lattice-dilatation effect and the electron-phonon interaction. The PL measurements in the experimental temperature range showed that the emission near 530 nm is due to the indirect transition in the α-V2O5 film.
Representations and Policy Change: Evidence from the Canadian-Flag Shipping Industry
Authors: Guy Emmanuel
Published: May 2013

The paper explores change in shipping nexuses via the Canadian example. Two dimensions of this institutional framework are contrasted. On one hand, the industry segment of Canadian-flag vessels operate under a regime that reserves domestic trade to national carriers. On the other hand, more recent initiatives seek to develop long-term connectivity with international shipping networks through a trade corridor planning approach. Derived from new institutionalisms and cognitive policy analysis, the interpretation of the case studies is achieved through a conceptual framework that emphasises the influence of representations. The paper underlines how actors refer to ideational frameworks to build credibility when working towards desired institutional change or reacting to proposed amended policies.
Placental Surfaces and the Geographies of Bodily Interiors
Authors: Colls Rachel , Fannin Maria
Published: May 2013

Within geographical research on ‘the body’, a focus on the surfaces of bodies has been useful for considering how body boundaries, most often implied to begin and end at the skin, (de)limit, (de)regulate, and (de)stabilise what we come to know as ‘a body’. Such work draws attention to how meaning is inscribed ‘upon’ such surfaces and on the fluids that move across, within, and through those surfaces: for example blood, breast milk, and excrement. This paper, however, considers the potential for thinking geographically about interior bodily surfaces by engaging with the placenta. The placenta is a temporary organ that forms in a woman's body only during pregnancy and whose purpose is to mediate the flow of substances between a woman's body and the foetus. It is often considered to have two surfaces, the maternal and foetal surface, or to be ‘a’ surface in and of itself. Our intention is to think geographically ‘with’ ‘the placenta’ in order to focus on what interior surfaces can ‘do’ rather than ‘what they mean’. In so doing our contribution is twofold. Firstly, we will focus on the ‘resurfacing’ of the placenta when it moves outside of the body to be placed upon other (bodily) surfaces, taken back inside the body of origin, or put to use in research. This is significant for highlighting the specific mobilities and temporalities of interior bodily surfaces. Secondly, we consider the theoretical and ethical significance of the placenta for geography by engaging with Luce Irigaray's account of the placental relation between mother and foetus understood as a space of mediation or ‘space between two’. In particular we are interested in considering the geographical potential of the sexed specificities of interior body surfaces, or their ‘morpho-logics’, for understandings of relationality, between self and other, and body and world; in short, we work with the placenta as a ‘relational organ’ in order to uncover new and potentially enlivening ethical spaces of exchange.
Shipping Container Mobilities, Seamless Compatibility, and the Global Surface of Logistical Integration
Authors: Martin Craig
Published: May 2013

Recent notions of surface emanating from poststructuralist theories posit surface as an ‘event’: expressionistic, restless, turbulent. In this paper I focus on a different idea of surface: one where the multiplicity of such restlessness is apparently immobilised. This perspective is tellingly advocated by the logistically driven movement of commodities on a global scale. Steinberg has argued that postmodern capitalism utilises a spatial logic that is redolent of earlier forms of capitalism, viewing ocean space in particular as a controllable void. Building on this debate, I set out to interrogate the construction of a ‘global surface of logistical integration’: those spatiotemporal mechanisms of control employed by the commercial logistics sector, which attempt to create an integrated and continuous global surface devoid of differences between ocean and land. In particular, the intermodal shipping container and its attendant apparatus of standardisation is taken as a paradigm of producing surface compatibility.
The Socionatural Engineering of Reductionist Metaphors: A Political Ecology of Synthetic Biology
Authors: Rossi Jairus
Published: May 2013

Political ecologists and biomedical anthropologists influenced by science and technology studies view genes as socionatural articulation points, or boundary objects, in the reshaping of societies, natures, and economies. Many of these scholars portray genetic technology as a tool for producing a new class of commodities. Scientists working for biotechnology corporations, they argue, mobilize the reductive metaphor that genes are information or code. They do this to stabilize genes for trade and ownership. Social scientists note that social negotiations involved in this reductive work, along with contingencies in the biological functioning of genes, limit and pattern how genetic material can be commodified. In this paper I critically review and extend these empirical analyses with attention to how current legal battles are redefining how genes can be owned. I then identify places where political ecologists can contribute to detailing the social, legal, and biological mutations motivated by the commodification of genes. This attention is crucial as traditional genetic technologies are being replaced by synthetic biology. Synthetic biology is a set of scientific practices that attempt to actualize the reductive informational code metaphor. Synthetic biologists seek to strip genes and organisms of their unpredictable behaviors by building organisms from the ground up, according to engineering design principles. By detailing synthetic biologists' attempts to reengineer both the structure of genetic code, and the cellular systems that give this code material expression, I first argue that synthetic technologies are producing standardized organisms and molecular parts that are extremely conducive to commodification. Additionally, I assert that the sociotechnical strategies employed by synthetic biologists to find and create useful genetic material intentionally avoid ambiguities in gene-ownership regimes as they are currently constituted. Finally, I examine situations where political ecologists can contribute to the critical analysis and transformation of synthetic biology's social and technical terrains.
Unscripted (in)Justice: Exposure to Ecological Hazards in Metropolitan Accra
Authors: Oteng-Ababio Martin
Published: May 2013

The author examines geographies of environmental hazards in Accra, declared a Millennium City on I5 January 2010. With the aid of both primary and secondary data, it is shown how environmental governance has shifted under neoliberalism, and the author demonstrates how a review of Accra's waste disposal problems could elucidate how such paradigm shift has contributed to urban social injustice. Current practices are seen as a symptom of poor governance and the value of understanding intraurban differentials is interrogated. It is posited that the current representations as to who bears the brunt of any possible health-risk outcomes appear abstract, incomplete, and poorly understood. The author illustrates how ineffective and insufficiently attentive governance can exacerbate health risks facing the entire society, and suggests that addressing inequalities may be among the most effective interventions to ensure sustainable environmental management, improve health, and guarantee social cohesion in the urban space.
The Quarry as Sculpture: The Place of Making
Authors: Paton David A
Published: May 2013

This paper traces a geographical reading of worked Cornish granite, evidenced by a sustained period of research in Trenoweth Dimension Granite quarry near Penryn, in Cornwall. As a sculptor exploring a practice of geography, I weave a narration of my auto-ethnographic research as an apprentice sawman and mason into a discourse on time and materiality. I focus on processes of accumulating familiarity with material subjects, leading to the erosion of fixed surface structures. I address issues arising from this research related to place making; identifying modes of representation, craft, labour practices, and the relational activities of worked matter within the context of a working quarry. Taking Ingold's call to redress material culture's emphasis on materiality over materials, I argue for an appreciation of matter as sentient, where the destabilised surface forms the conduit for richer relations to form and grow.
Adaptational significance of variations in DNA methylation in clonal plant Hierochloe glabra (Poaceae) in heterogeneous habitats
Authors: Bian Rujin , Nie Dandan , Xing Fu , Zhou Xiaoling , Gao Ying , Bai Zhenjian , Liu Bao
Published: May 2013

As a prominent epigenetic modification, cytosine methylation may play a critical role in the adaptation of plants to different environments. The present study sought to investigate possible impacts of differential levels of nitrogen (N) supply on cytosine-methylation levels of a clonal plant, Hierochloe glabra Trin. (Poaceae). For this purpose, nitrate was applied at concentrations of 0, 0.15, 0.30 and 0.45 g N kg–1 soil, and ecologically important morphological traits were measured. The methylation-sensitive amplification polymorphism method was also conducted to analyse the variations in DNA cytosine methylation. Our results showed that N addition reduced CHG cytosine-methylation levels markedly compared with control plants growing in homogeneous pots (P = 0.026). No substantial differences were observed in morphological traits at the end of the growing stage, except for the highest ratio of leaf area to leaf dry mass in the medium-N patch (P = 0.008). However, significant linear regression relationships were found between cytosine-methylation levels and morphological traits, such as bud number and rhizome length and biomass. In conclusion, the higher cytosine-methylation level may activate asexual reproduction to produce more offspring and expand plant populations, possibly helping clonal plants to adapt to heterogeneous habitats.
Numerical calculations for diffusion effects in the well-of-the-well culture system for mammalian embryos
Authors: Matsuura Koji
Published: May 2013

Recent studies suggest that the microenvironment and embryo density used during embryo culture considerably affect development to the blastocyst stage. High embryo density allows for autocrine secretions to diffuse to neighbouring embryos during group culture, with a positive effect on further development. A variation of group culture is the well-of-the-well (WOW) culture system, allowing for individual identification of embryos cultured in small holes in a microdroplet. Bovine blastocyst development is higher in the WOW culture system than in conventional group culture. To compare the concentration of chemical factors between conventional and WOW culture, a model was constructed to calculate the concentration of secreted factors based on Fick’s second law of diffusion using spreadsheet software. Furthermore, model was used to determine the concentration of growth factors and waste materials adjacent to the embryo periphery. The results of these calculations suggest that the highest difference in the concentration of secreted small molecules and macromolecules was at the most two- to threefold, with the concentrations reduced more and diffusion kinetics facilitated to a greater extent in the WOW culture system. The average ratio of the concentration of secreted macromolecules (10 nm diameter) around the embryos was also compared between systems with well widths of 0.1 and 0.3 mm. The concentration of secreted materials surrounding embryos increased in a narrow tapered well. The findings suggest that the WOW culture system is better than conventional group culture because of the increased final concentration of autocrine factors and higher diffusion kinetics of waste materials.
A Report on the British Premiere of Death of Yazdgerd: A Cross-cultural Adaptation?
Authors: Kalami Proshot
Published: May 2013

In the spring semester of 2010, the students of the module “Non Western Performances” at Loughborough University were directed by Sudipto Chatterjee to stage the UK premiere of Bahram Beyzaie's canonical play, Death of Yazdgerd (1979). The play, which was initially supposed to be a student-led workshop as part of the module's practice, took a life of its own and turned into a full-blown production. The production consisted of all the registered students of the module who formed the cast and the crew, the main tutor and director Sudipto Chatterjee, the co-tutor and dramaturge Proshot Kalam) and the two technical tutors (Dave Hill and Mark Simpson). The present essay is an attempt to analyze the cross-cultural aspects and the practical approaches undertaken by the crew for the production of the play.
I Heard about it from a Friend: Assessing Interest in Buprenorphine Treatment
Authors: Fox Aaron D. , Shah Pooja A. , Sohler Nancy L. , Lopez Carolina M. , Starrels Joanna L. , Cunningham Chinazo O.
Published: May 2013

Background

In the United States, opioid abuse and dependence continue to be a growing problem, whereas treatment for opioid abuse and dependence remains fairly static. Buprenorphine treatment for opioid dependence is safe and effective but underutilized. Prior research has demonstrated low awareness and use of buprenorphine among marginalized groups. This study investigates syringe exchange participants’ awareness of, exposure to, and interest in buprenorphine treatment.

Methods

Syringe exchange participants were recruited from a mobile unit performing outreach to 9 street-side sites in New York City. Computer-based interviews were conducted to determine (1) opioid users’ awareness of, exposure to, and interest in buprenorphine treatment; and (2) the association between awareness or exposure and interest in buprenorphine treatment. Logistic regression models were used to examine the associations between awareness of, direct exposure (i.e., having taken buprenorphine) or indirect exposure (i.e., knowing someone who had taken buprenorphine)S to, and interest in buprenorphine treatment.

Results

Of 158 opioid users, 70% were aware of, 32% had direct exposure to, and 31% had indirect exposure to buprenorphine; 12% had been prescribed buprenorphine. Of 138 opioid users who had never been prescribed buprenorphine, 57% were interested in buprenorphine treatment. In multivariate models, indirect exposure was associated with interest in buprenorphine treatment (adjusted odds ratio [AOR] = 2.65, 95% confidence interval [CI]: 1.22–5.77), but awareness and direct exposure were not.

Conclusions

Syringe exchange participants were mostly aware of buprenorphine and interested in treatment, but few had actually been prescribed buprenorphine. Because indirect exposure to buprenorphine was associated with interest in treatment, future interventions could capitalize on indirect exposure, such as through peer mentorship, to address underutilization of buprenorphine treatment.
Therapeutic Alliance in Justice-Involved Adolescents Undergoing Mental Health Treatment: The Role of Callous-Unemotional Traits
Authors: Simpson TiffanyP. , Frick PaulJ. , Kahn RachelE. , Evans LisaJ.
Published: May 2013

The current study tested factors that could influence both youth and therapist-reported therapeutic alliance in 58 male adolescents ranging in age from 15 to 18 years old ( M = 16.81, SD = 1.02) who were adjudicated for a delinquent offense and identified as needing mental health treatment. Therapeutic alliance was assessed through self-report by both the adolescent and therapist. Callous-unemotional (CU) traits and antisocial history were assessed through self-report and official record review respectively. Results indicated that the number of previous offenses was negatively associated with adolescent-reported therapeutic alliance but this was qualified by an interaction between antisocial history and CU traits. In those low on CU traits, there was a negative but non-significant association between number of previous offenses and the quality of the therapeutic alliance, whereas the association was significant and positive for those high on CU traits. In addition, CU traits were associated with violent institutional infractions during treatment. Thus, the combination of high CU traits and a high number of previous offenses seemed to reflect a group of adolescents who reported more positive therapeutic alliances but still had violent institutional infractions. These results provide support for tailored interventions for youth high on CU traits which consider the quality of the therapeutic relationship.
Gender, Psychiatric Symptomatology, Problem Behaviors and Mental Health Treatment in a Canadian Provincial Correctional Population: Disentangling the Associations between Care and Institutional Control
Authors: Archambault Kyle , Joubert David , Brown Greg
Published: May 2013

Efforts to increase the provision of mental health care for prisoners have been met with criticism suggesting that mental health treatment in prison is likely to serve institutional rather than inmates’ interests. In this context, the present study seeks to explore the use of various forms of mental health treatment with mentally ill offenders as a function of diagnosis, problem behavior in the institution, and gender among a sample of 513 Canadian inmates. The data was obtained from a review of institutional files as well as face-to-face interviews with inmates. Associations between the main variables were examined using multivariate logit analysis. Results indicate that the provision of mental health care in Canadian provincial institutions is still minimal. Furthermore, women inmates are significantly more likely to receive mental health services compared with their male counterparts. Psychiatrists appear to have a particularly important role in managing conduct problems in the institution. Finally, the presence of dysphoria or social withdrawal in inmates is associated with an increased probability of being provided with individual or group therapy. The results suggest that factors other than psychiatric symptomatology, such as gender and institutional misconduct, may influence the provision of mental health care services in correctional settings.
The Relationship between Sentence Meaning and Word Order: Evidence from Structural Priming in German
Authors: Köhne Judith , Pickering Martin J. , Branigan Holly P.
Published: May 2013

Most theories of human language production assume that generating a sentence involves several stages, including an initial stage where the prelinguistic message is determined and a subsequent stage of grammatical encoding. However, it is contentious whether grammatical encoding involves separate stages of grammatical-function assignment and linearization. To address this question, we examined the mapping between the message level and grammatical encoding in two structural priming experiments in which German speakers choose between three different structures expressing ditransitive events. Although speakers showed a tendency to repeat the order of constituents (noun phrase–prepositional phrase, NP–PP, vs. NP–NP), they were additionally primed to repeat the order of thematic roles when constituent structure was constant (NPRECIPIENT–NPTHEME vs. NPTHEME–NPRECIPIENT). Experiment 2 found that the latter effect could not be due to persistence of the order of phrases referring to animate and inanimate entities. These results suggest a direct mapping of thematic roles to word order, consistent with a model in which the message is mapped onto syntactic structure in a single stage.
Ethical Considerations: Cogniceuticals in the Military
Authors: Russo Michael B. , Stetz Melba C. , Stetz Thomas A.
Published: May 2013

This chapter discusses the ethical and cross-cultural considerations in military environments of psychopharmaceutical agents that alter alertness, attention, perception, and sleep. Collectively these psychotropics are referred to as cogniceuticals. The chapter presents six questions to guide in their ethical use: Have all available non-pharmacologic alternatives been fully utilized?; is the circumstance such that not using a cogniceutical risks life or health?; is the medication safe for use in this individual, and safe within the operational environment?; is the use of the medication consistent with its dosage and pharmacological function; is use truly voluntary and informed?; and is appropriate medical supervision and oversight provided? If the answers are yes to all of these questions, then the chapter suggests that use of a cogniceutical is ethically supportable.
Competence and Autonomy: The Cases of Driving, Voting, and Financial Independence
Authors: Karlawish Jason
Published: May 2013

The goal of this chapter is to examine various issues at the intersection of ethics and measurement of competency. The chapter uses three distinct decisions as case studies: driving, voting, and financial management. The point of this chapter is that while we have cast off the chains of the tyranny of status, we hazard shackling ourselves with a new tyranny: measurement. If competency is a numbers game, then whoever controls the numbers controls capacity and, in turn, autonomy.