bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating conical intersection dynamics in the condensed phase with hybrid quantum master equations
Authors: Schile Addison J. , Limmer David T.
Published: July 2019

We present a framework for simulating relaxation dynamics through a conical intersection of an open quantum system that combines methods to approximate the motion of degrees of freedom with disparate time and energy scales. In the vicinity of a conical intersection, a few degrees of freedom render the nuclear dynamics nonadiabatic with respect to the electronic degrees of freedom. We treat these strongly coupled modes by evolving their wavepacket dynamics in the absence of additional coupling exactly. The remaining weakly coupled nuclear degrees of freedom are partitioned into modes that are fast relative to the nonadiabatic coupling and those that are slow. The fast degrees of freedom can be traced out and treated with second-order perturbation theory in the form of the time-convolutionless master equation. The slow degrees of freedom are assumed to be frozen over the ultrafast relaxation and treated as sources of static disorder. In this way, we adopt the recently developed frozen-mode extension to second-order quantum master equations. We benchmark this approach to numerically exact results in models of pyrazine internal conversion and rhodopsin photoisomerization. We use this framework to study the dependence of the quantum yield on the reorganization energy and the characteristic time scale of the bath in a two-mode model of photoisomerization. We find that the yield is monotonically increasing with reorganization energy for a Markovian bath but monotonically decreasing with reorganization energy for a non-Markovian bath. This reflects the subtle interplay between dissipation and decoherence in conical intersection dynamics in the condensed phase.
Settling dynamics of two spheres in a suspension of Brownian rods
Authors: Kumar Gaurav , Natale Giovanniantonio
Published: July 2019

We investigate via numerical simulations the settling dynamics of two non-Brownian rigid spheres in a dilute suspension of Brownian rods at low Reynolds numbers. Specifically, this work focuses on how the overall settling dynamics is affected by the coupling between the flow field around the spheres and the orientation of the rods. The Brownian motion introduces a finite relaxation time in the suspending medium which is modeled as a continuum. When the spheres fall along their centerline, the spheres experience two contributions: one Newtonian and a non-Newtonian contribution due to the presence of the Brownian rods. The interactions between the two settling spheres are evaluated as a function of Péclet number (Pe) and the distance between the centers of the spheres. Repulsive interactions are found, and these interactions are affected by Pe and the distance between the centers of the spheres. An analysis of the flow fields highlights the origin of these repulsive interactions in non-Newtonian elongational effects.
Aspects of semiconductivity in soft, porous metal-organic framework crystals
Authors: Muschielok Christoph , Oberhofer Harald
Published: July 2019

Metal-organic frameworks (MOFs) are known for their vast design space of possible structures, covering a wide range of often porous crystal structures and physical properties. Electrical conductivity, though, was—until very recently—not a feature usually associated with MOFs. On the other hand, well defined porous media such as MOFs, showing some measure of conductivity, could find uses in a huge number of fields ranging from electrochemistry to electronics and sensing. In this work, we therefore investigate the different aspects contributing to the bad conductivity in MOFs. Using Bardeen–Shockley deformation potential theory, we devise an approach that allows us to gauge all factors influencing the conductivity, including the availability of free charge carriers and their mobility. The latter itself is determined by the effective masses of the charge carriers, the material’s elastic constants, and the deformation potential constants, which measure an effective electron-phonon coupling. Based on these parameters, we study charge carrier mobility in metal (1,2,3)-triazolate MOF crystals, M(ta)2, where the metal is either iron, zinc, or ruthenium. Thereby, Zn(ta)2 was experimentally shown to have little to no conductivity, while Fe(ta)2 is one of the best currently known MOF semiconductors. Disregarding the fact that all three investigated MOFs show near-zero carrier densities due to their large bandgaps, our calculations reproduce the trends between Zn(ta)2 and Fe(ta)2. In contrast to that we find the Ru(ta)2 MOF, which to date has not been synthesized experimentally, to yield even better performance than iron triazolate. In summary, assuming, fox example, light doping to counter the large bandgap, our analysis of the factors influencing conductivity in MOFs allows us not only to confirm experimental trends but also to predict new, as yet unknown semiconducting MOF crystals.
Micki: A python-based object-oriented microkinetic modeling code
Authors: Hermes Eric D. , Janes Aurora N. , Schmidt J. R.
Published: July 2019

We have developed a flexible, general-purpose microkinetic modeling code, Micki, to analyze complex, heterogeneously catalyzed chemical reactions based upon first-principles calculations. This Python-based code is modular and object oriented, framing the development of microkinetic models in familiar chemical terms. We also present novel approaches, incorporated into Micki, to describe diffusion limited reactions, multidentate bindings, thermodynamically consistent lateral interactions, and Brønsted-Evans-Polanyi estimates of changes in barrier heights. Micki has built-in modules for subsequent analysis of microkinetic models, including degree of rate control and rate order. As a demonstration of the power and flexibility of the code, we build a microkinetic model for the water-gas shift reaction and compare to previously published experimental results and microkinetic models, showing that Micki can quantitatively reproduce experimental turnover frequencies with minimal empirical optimization.
Identification of fish families and species from the western Arabian Gulf by otolith shape analysis and factors affecting the identification process
Authors: Lin Yu-Jia , Al-Abdulkader Khaled
Published: July 2019

Otolith shape analysis was used to identify 16 fish species belong to 5 families from the western Arabian Gulf to construct a cost-effective method of delineating fish taxonomic groups. We further tested the factors potentially affecting the identification process, including using different dataset sources, sex, the number of candidate species, different sample sizes and different sampling procedures. No specific dataset outperformed any other in the identification of fish families and species. Using all data sources yielded the best performance. Otolith shape parameters were significantly affected by somatic length, but not by sex. The correct prediction rate declined as the number of candidate species increased. An insufficient sample size led to a reduction in correct prediction rates with increased variability. The effects of size-biased sampling were species specific and could greatly reduce the correct prediction rate if the species of interest exhibits strong allometric changes in otolith shape. Having multiple sources of data, information a priori to reduce the number of candidate species and sufficiently large sample sizes across wide size classes so as to include possible variations in otolith shape are key to the precise identification of fish families and species using otolith shape analysis.
Effects of DEM resolutions on LS and hillslope erosion estimation in a burnt landscape
Authors: Shan Linxin , Yang Xihua , Zhu Qinggaozi
Published: July 2019

The combined slope length and slope steepness factor (LS) is crucial in soil erosion models such as the revised universal soil loss equation (RUSLE), and is often calculated from digital elevation models (DEMs). With high-resolution DEMs becoming increasingly available in recent years, we face considerable challenges in selecting the optimal DEM for erosion modelling. In this paper, we present a case study on LS factor computation using various DEMs at resolutions ranging from 1 to 90 m over a burnt national park in New South Wales, Australia, aiming to assess the effects of DEM resolution on LS and hillslope erosion estimation. The LS was calculated based on RUSLE specifications and incorporated a variable cutoff slope angle that improves the detection of the beginning and the end of each slope length. Results show the trend of an increase in the estimated LS value as the DEM resolution became coarser. We consider 5–10-m DEMs to have optimal resolution because the LS values calculated at this range were closer to the LS values measured at the 12 soil plots over the study area. We also assessed different sampling methods for LS value extraction and statistical analysis. The sampling method based on contributing area was more representative compared with point-based and buffer sampling methods. Findings from this study will be useful for choosing the optimal DEM resolution and sampling method in hillslope erosion modelling.
Variational implicit-solvent predictions of the dry–wet transition pathways for ligand–receptor binding and unbinding kinetics
Authors: Zhou Shenggao , Weiß R. Gregor , Cheng Li-Tien , Dzubiella Joachim , McCammon J. Andrew , Li Bo
Published: July 2019

Significance

The kinetics of ligand–receptor (un)binding—how fast a ligand binds into and resides in a receptor—cannot be inferred solely from the binding affinity which describes the thermodynamic stability of the bound complex. A bottleneck in understanding such kinetics, which is critical to drug efficacy, lies in the modeling of the collective water fluctuations in apolar confinement. We develop a theoretical approach that couples a variational implicit-solvent model with the string method to describe the dry–wet transition pathways, which then serve as input for the ligand multistate Brownian dynamics. Without explicit descriptions of individual water molecules, our theory predicts the key thermodynamic and kinetic properties of unbinding and binding, the latter in quantitative agreement with explicit-water molecular dynamics simulations.
Cellular responses to reactive oxygen species are predicted from molecular mechanisms
Authors: Yang Laurence , Mih Nathan , Anand Amitesh , Park Joon Ho , Tan Justin , Yurkovich James T. , Monk Jonathan M. , Lloyd Colton J. , Sandberg Troy E. , Seo Sang Woo , Kim Donghyuk , Sastry Anand V. , Phaneuf Patrick , Gao Ye , Broddrick Jared T. , Chen Ke , Heckmann David , Szubin Richard , Hefner Ying , Feist Adam M. , Palsson Bernhard O.
Published: July 2019

Catalysis using iron–sulfur clusters and transition metals can be traced back to the last universal common ancestor. The damage to metalloproteins caused by reactive oxygen species (ROS) can prevent cell growth and survival when unmanaged, thus eliciting an essential stress response that is universal and fundamental in biology. Here we develop a computable multiscale description of the ROS stress response in
Escherichia coli
, called OxidizeME. We use OxidizeME to explain four key responses to oxidative stress: 1) ROS-induced auxotrophy for branched-chain, aromatic, and sulfurous amino acids; 2) nutrient-dependent sensitivity of growth rate to ROS; 3) ROS-specific differential gene expression separate from global growth-associated differential expression; and 4) coordinated expression of iron–sulfur cluster (ISC) and sulfur assimilation (SUF) systems for iron–sulfur cluster biosynthesis. These results show that we can now develop fundamental and quantitative genotype–phenotype relationships for stress responses on a genome-wide basis.
Toxicity drives facilitation between 4 bacterial species
Authors: Piccardi Philippe , Vessman Björn , Mitri Sara
Published: July 2019

Significance

Microbial communities play a major role in our lives, but we understand little about how species within them interact. Here, we studied 4 bacterial species that could degrade toxic industrial fluids. We expected these species to compete, but instead found that they all benefited from each other: Alone, only 1 species could survive, while together they all grew and degraded the fluid. However, this result depended on the environment. Positive interactions were most common in the toxic fluid, and, if we made survival easier, for example by adding nutrients, bacteria began to compete. Our findings provide a simple intuition: In a harsh environment where single species are unable to grow, the only option becomes to work together.
Diachronic frame analysis
Authors: Law James
Published: July 2019

Frame Semantics offers a valuable perspective on mechanisms of semantic change, particularly metonymy. However, corpus-based frame analysis has rarely been applied to diachronic data. The potential of this approach is illustrated with a diachronic description of the Purpose frame in French, based on 1,429 tokens of 17 frame-evoking words. Metonymic mappings in the frame allow Means and Medium to replace Agent. A multinomial logistic regression model shows that usage of these mappings has increased since 1600 and is conditioned by genre and the frequency and grammatical category of the frame-evoking word. The approach may inform how metonymy leads to lexicalized semantic change.
The alternating predicate puzzle
Authors: Barðdal Jóhanna , Eythórsson Thórhallur , Dewey Tonya Kim
Published: July 2019

A long-standing divide between Icelandic and German in the literature takes for granted that there are non-nominative subjects in Icelandic, while corresponding arguments in German have been analyzed as objects (Zaenen et al. 1985;Sigurðsson 1989). This is based on two differences between these languages: (a) differences with regard to control and conjunction reduction and (b) apparent subject behavior of the nominative indat-nomconstructions in German. This article focuses on the latter, introducing into the discussion the concept of alternating predicates, that is,dat-nompredicates that systematically alternate between two diametrically-opposed argument structure constructions,dat-nomandnom-dat. A comparison between Icelandic and German shows that Icelandicdat-nompredicates are of two types, a non-alternatinglíkatype and an alternatingfalla í geðtype, whereas German seems to exhibit only the alternating type. On this assumption, the apparent subject behavior of the nominative in German is easily explained, since such occurrences in fact involve thenom-datconstruction and not thedat-nomconstruction. Therefore, the subject behavior of the nominative innom-datconstructions does not invalidate a subject analysis of the dative indat-nomconstructions in German. The analysis is couched in the framework of construction grammar.
Two-way interaction between switching arc and solid surfaces: distribution of ablated contact and nozzle materials
Authors: Kadivar Ali , Niayesh Kaveh
Published: July 2019

This paper is devoted to two-way plasma-surface interactions by investigating how the plasma arc ablates the nozzle and contacts and how the distribution of ablated materials changes the plasma parameters.

For this purpose, a two-dimensional time-dependent model, in axial symmetric coordinates, for an arc at atmospheric pressure burning within a polytetrafluoroethylene nozzle is created. A computational fluid dynamics equations system is solved for plasma velocity, pressure, temperature, magnetic vector potential, and electrical potential. Radiation is modeled based on net emission coefficient and contacts, and nozzle ablation is also considered to better describe the arc formation, contact cooling, and arc temperatures, more precisely. The sublimated materials from contacts and nozzle will be used to calculate the distribution of plasma composition (i.e. ablated mixture ratio). The calculated ratio is used to change the plasma parameters, and data processing techniques are utilized to derive particle distribution and temperature profiles of the arc to investigate its thermo-electrical behavior. The simulation results show good agreement with the measurements obtained in an experimental setup already designed and published. This study provides support to the experimental work and contrariwise. The presence of ablated points on nozzle and contacts, which further modify plasma parameters and therefore the arc voltage are discussed.
Switching between deterministic and accidental Dirac degeneracy by rotating scatterers and the multi-channel topological transport of sound
Authors: Xie Xiang , Li Honglang , Peng Yugui , Zhu Xuefeng , Luo Wei , Zhao Degang
Published: July 2019

In this study, a Dirac cone is yielded at the corner of the Brillouin zone of a two-dimensional solid phononic crystal, which consists of a triangular array of hexagonal steel with a trilobal hole drilled in the center. With the rotation of the trilobal hole, the Dirac degeneracy switches between the deterministic form and accidental form. Every Dirac point is the critical state of a topological phase transition process, which occurs six times within an angular period of

120
°
.

This structure offers a flexible way to achieve topological transitions and provides multiple routes to construct an interface that supports valley-dependent edge states between two topologically distinct PCs. The associated backscattering suppressed wave propagation along the multiple curved interface channels is also demonstrated. In addition, our design shows the robust propagation of topological interface states against the perturbation of the structure. This study could potentially be significant in the design of acoustic devices for practical applications, such as acoustic signal lossless transport and tunable multi-channel sound transmission.
An International Survey of Front-end Receivers and Observing Performance of Telescopes for Radio Astronomy
Authors: Bolli P. , Orfei A. , Zanichelli A. , Prestage R. , Tingay S. J. , Beltrán M. , Burgay M. , Contavalle C. , Honma M. , Kraus A. , Lindqvist M. , Perez J. Lopez , Marongiu P. , Minamidani T. , Navarro S. , Pisanu T. , Shen Z.-Q. , Sohn B. W. , Stanghellini C. , Tzioumis T. , Zacchiroli G.
Published: July 2019

This paper presents a survey of microwave front-end receivers installed at radio telescopes throughout the world. This unprecedented analysis was conducted as part of a review of front-end developments for Italian radio telescopes, initiated by the Italian National Institute for Astrophysics in 2016. Fifteen international radio telescopes have been selected to be representative of the instrumentation used for radio astronomical observations in the frequency domain from 300 MHz to 116 GHz. A comprehensive description of the existing receivers is presented and their characteristics are compared and discussed. The observing performances of the complete receiving chains are also presented. An overview of ongoing developments illustrates and anticipates future trends in front-end projects to meet the most ambitious scientific research goals.
Benchmark estimates for aboveground litterfall data derived from ecosystem models
Authors: Li Shihua , Yuan Wenping , Ciais Philippe , Viovy Nicolas , Ito Akihiko , Jia Bingrui , Zhu Dan
Published: July 2019

Litter production is a fundamental ecosystem process, which plays an important role in regulating terrestrial carbon and nitrogen cycles. However, there are substantial differences in the litter production simulations among ecosystem models, and a global benchmarking evaluation to measure the performance of these models is still lacking. In this study, we generated a global dataset of aboveground litterfall production (i.e. cLitter), a benchmark as the defined reference to test model performance, by combining systematic measurements taken from a substantial number of surveys (1079 sites) with a machine learning technique (i.e. random forest, RF). Our study demonstrated that the RF model is an effective tool for upscaling local litterfall production observations to the global scale. On average, the model predicted 23.15 Pg C yr−1 of aboveground litterfall production. Our results revealed substantial differences in the aboveground litterfall production simulations among the five investigated ecosystem models. Compared to the reference data at the global scale, most of models could reproduce the spatial patterns of aboveground litterfall production, but the magnitude of simulations differed substantially from the reference data. Overall, ORCHIDEE-MICT performed the best among the five investigated ecosystem models.
Effect of Heat Treatment on Microstructure and mechanical hardness of aluminum alloy AA7075
Authors: Aliyah A N , Anawati A
Published: July 2019

The mechanical properties of high strength aluminum alloy AA7075 were greatly affected by heat treatment. This paper was intended to clarify the effect of heat treatment on the microstructure and the mechanical hardness of commercial alloy AA7075-T651. Heat treatment was performed at a variation temperature of 300, 400, 500, and 600°C for 1 h in a vacuum furnace followed by a water quench. The surface observation was done by using optical and electron microscopy and the mechanical hardness was measured by the Vickers Hardness test. The XRD result on as-received alloy revealed the precipitates in the alloy was MgZn2, Al7Cu2Fe, and Al2CuMg. The average hardness of the as-received alloy was 136 HV. The hardness became significantly lower (78.5 HV) after heat treatment at 400°C while heat treatment at others temperature gave hardness in the range 116-122 HV. Heat treatment induced grain growth and dissolution of metastable precipitates. Reduction in the number of MgZn2 and Fe-rich phase decreased the hardness significantly. Heat treatment above 400°C promoted segregation of fresh precipitates which enhanced the metal hardness again. The metallic grain size increased with heat treatment temperature. At 600°C, most of the precipitates were segregated along the equiaxed grain boundaries.
Study on Phases Development and Mechanical Properties in a Fe-Ni-Al Carbide Free Bainitic Steel Based on Lateritic Steel After Warm Rolling
Authors: Meryanalinda  , Ariati M , Citrawati F
Published: July 2019

The abundant reserve of lateritic ores in Indonesia is currently processed and studied to fulfil the national steel demand in several sectors, one of which is for railway application. The development of lateritic steel (Fe-Ni) as carbide free bainitic steel is carried out by adding Al to the Fe-Ni alloy. In this research, the effect of warm rolling and Al addition to the formation of carbide, phases development and mechanical properties was studied. The warm-rolled thermomechanical process (TMCP) was carried out by heating the material at 945°C for 20 minutes followed by second heating to 400°C, 450°C and 500°C with holding time for 30 minutes. The materials then warm rolled with 50% and 70% reductions using 20 tons capacity roller machine and then air cooled outside the furnace chamber. The microstructure of the as-rolled materials was characterized using optical microscope (OM) and scanning electron microscope (SEM), while the phases, the chemical distribution and the possibility of carbide formation were examine using X-Ray Diffraction (XRD) pattern and energy dispersive X-Ray spectroscopy (EDS). The mechanical properties of the material were observed using macro Rockwell hardness test. It was revealed that the addition of Al altered the phases of Fe-Ni lateritic steel significantly. Furthermore, Al addition gives positive effects to the Fe-Ni lateritic steel by increasing hardness. The reductions applied during warm rolling were observed to have effect on the growth of the grains in the Fe-Ni-Al lateritic steel.
Synthesis of immobilized nanostructured ZnO grown on glass and its photocatalytic activity for cyanide degradation
Authors: Mohar R S , Isnaeni  , Hadiko G
Published: July 2019

Nanostructured ZnO has been synthesized by using two simple steps, i.e. ultrasonic spray pyrolysis (USP) and chemical bath deposition (CBD) methods on glass substrates. The crystal structure, morphology, photoluminescence (PL) emission, and photocatalytic activity for cyanide degradation were studied. From the X-ray diffraction (XRD) examination, it was observed that the ZnO had the hexagonal wurtzite structure with the preferred orientation of (100). The field emission scanning electron microscopy (FESEM) image displayed that the ZnO had grass-like and bush-like nanostructures. The PL spectrum exhibited the near band-edge emission (NBE) peak at ∼380 nm. The photocatalytic activity of the nanostructured ZnO for cyanide degradation in aqueous solution was evaluated under warm-white lamp (color temperature of 2700 K) and cool-daylight lamp (color temperature of 6500 K) irradiations, resulting enhanced cyanide degradation rates in presence of the nanostructured ZnO.
Experimental study on crack propagation of stainless steel 304 material under amplitude overloads
Authors: Hartanto Andreas , Himawan Roziq , Sutanto Hadi
Published: July 2019

Fatigue mechanisms caused by dynamic loadings starts with cracks that occurred in a material. Under conditions such as transient conditions, an earthquake or instantaneous external loads, some parts of nuclear reactor that initially receive operating loads can be overloaded. The purpose of this research is to investigate the change of crack propagation in stainless steel 304 material related with amplitude overloads. The crack propagation test used the axial dynamic testing with the maximum stress (σ max) of 145 MPa, stress ratio R = 0.1 and over loading ratio (OVR) of 1.5, 1.75, 2. The results showed that the amplitude overloads caused the crack to propagate slowly as the crack tip formed a branch. The higher crack growth rate also showed the higher stress intensity factors in the crack tip.
Effect of samarium on microstructure and intermetallic formation in Al-5Zn-0.5Si alloy
Authors: Ferdian D , Pratama J R , Pratesa Y
Published: July 2019

Aluminium-Zinc-Silicon alloy is a material candidate for low voltage sacrificial anode. Nevertheless, iron-rich intermetallic phase that formed in the interdendritic region can reduce its efficiency due to the self-corrosion phenomenon. Samarium addition is expected to modify the formation of iron-rich intermetallic phase. The alloying process was conducted with melting of aluminium and other additional element in mini electric resistance furnace. Furthermore, characterization of the alloys was performed using optical emission spectrometer, differential scanning calorimetry, optical metallography and scanning electron microscopy equipped with energy dispersive spectrometer. The result showed that samarium can refined the secondary dendrite arm spacing (SDAS) from 89.6 μm to 61.4 μm. Samarium also shifted the solidification temperature of the alloy which affected the size of SDAS and formation of Al2Si2Sm intermetallic phase.
Modification of ledeburite microstructure on impeller blades by mean of heat treatment
Authors: Purwadi W , Idamayanti D
Published: July 2019

Water pump machine impeller is made of gray cast iron with some variation of wall thickness. The thin part undergoes consequently a very rapid cooling and promotes the formation of hard ledeburite, This study removes the already formed ledeburite ((α + Fe3C) + Fe3C) by mean of heat treatment. By calculating the mass fraction of iron carbide at the level of 5%, heating the material at the austenite temperature, holding it for 2 hours and cooling it subsequently in the air, ledeburite changes to ferrite and graphite. Graphite is formed discrete along the grain boundaries of previous pearlite after the completion of heat treatment. The graphite resembles a randomly oriented eutectic undercooling type D and this is associated with a decrease of hardness to 115HV at the tip of the impeller blade.
The Effect of Slow Evaporation on Ca, Na, K, and Mg Concentration in Natural Brine from Ciseeng, West Java
Authors: Rhamdani A R , Lalasari L H , Sulistyono E , Setiawan I , Firdiyono F
Published: July 2019

Indonesia’s location in the ring of fire gives Indonesia a lot of natural resources such as natural brine water from Ciseeng, West Java. Natural brine contains a lot of minerals such as Na, K, Ca, Mg. and could potentially be the source of those elements. One of the common process for recovering minerals in brine water is through solar evaporation process. This process is ineffective because the evaporation stops in the night time. The purposes of this study are to find another method for concentrating brine, characterize natural brine from Ciseeng, West Java, and investigate the effect of new evaporation method to the brine. In this work, the author conducted the evaporation using electric heater to keep the solution in the desired temperature coupled with blowers to blow air to the surface of the solution for 10 days. The volume of the system was maintained by making up the evaporated water with fresh brine. The results indicate that the evaporation can increase the Mg, Na, and K concentration up to 282%, 283%, and 207%, respectively, while the Ca concentration stays relatively constant compared to the fresh brine. The brine’s °Bé increase from 2.5 to 6. In the process, about 158% of Ca and 51% of Na were recovered as precipitate.
Comment on ‘The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals’
Authors: Maździarz Marcin
Published: July 2019

Recently Haastrup et al 2018 (2D Mater. 5 042002) introduced the Computational 2D Materials Database (C2DB), which organises a variety of structural, thermodynamic, elastic, electronic, magnetic, and optical properties of around 1500 two-dimensional materials distributed over more than 30 different crystal structures. Unfortunately, the work contains serious and fundamental flaws in the field of elasticity and mechanical stability tests that make it unreliable.
Adaptor protein-3 complex is required for Vangl2 trafficking and planar cell polarity of the inner ear
Authors: Tower-Gilchrist Cristy , Zlatic Stephanie A. , Yu Dehong , Chang Qing , Wu Hao , Lin Xi , Faundez Victor , Chen Ping
Published: July 2019

Planar cell polarity (PCP) regulates coordinated cellular polarity among neighboring cells to establish a polarity axis parallel to the plane of the tissue. Disruption in PCP results in a range of developmental anomalies and diseases. A key feature of PCP is the polarized and asymmetric localization of several membrane PCP proteins, which is essential to establish the polarity axis to orient cells coordinately. However, the machinery that regulates the asymmetric partition of PCP proteins remains largely unknown. In the present study, we show Van gogh-like 2 (Vangl2) in early and recycling endosomes as made evident by colocalization with diverse endosomal Rab proteins. Vangl2 biochemically interacts with adaptor protein-3 complex (AP-3). Using short hairpin RNA knockdown, we found that Vangl2 subcellular localization was modified in AP-3–depleted cells. Moreover, Vangl2 membrane localization within the cochlea is greatly reduced in AP-3–deficient mocha mice, which exhibit profound hearing loss. In inner ears from AP-3–deficient mocha mice, we observed PCP-dependent phenotypes, such as misorientation and deformation of hair cell stereociliary bundles and disorganization of hair cells characteristic of defects in convergent extension that is driven by PCP. These findings demonstrate a novel role of AP-3–mediated sorting mechanisms in regulating PCP proteins.
Free Indirect Discourse
Authors: Gunn Daniel P.
Published: July 2019

In free indirect discourse (FID), the narrative discourse of a text incorporates the language and subjectivity of a character, including emotional coloring, deictics, judgments, and style, without an introductory attributing frame like “she thought that” and without shifts in the pronouns or the tense sequence to accord with the character’s perspective. By combining the immediacy of direct quotation and the flexibility of indirect discourse, FID allows for the seamless integration of a character’s thought or speech, with all of its distinctive markers, into the narratorial discourse. Because FID occurs in the context of narratorial discourse and allows for a fluid movement back and forth between narratorial and figural subjectivities, it characteristically entails a mixture or interplay of two voices—the narrator’s and the character’s—in the same utterance, as in parody or mimicry. The evocation of a character’s thought or speech through FID and its relation to narratorial commentary and report can be subtle and nuanced, and identifying and making sense of FID sentences requires significant interpretive activity on the part of the reader. FID has been a crucially important technique for the representation of consciousness in the English novel, particularly in the tradition which runs from Jane Austen through George Eliot to Henry James, Virginia Woolf, and James Joyce, which concerns itself increasingly with the imagined thought-lives of characters. Depending on the context, FID passages can be presented sympathetically, inviting the reader to immerse herself or himself unreservedly in the character’s thought or speech, or ironically, with the language of the character creating a dissonant effect against the background of the narrator’s discourse and the novel’s design. FID is also sometimes referred to as style indirect libre, free indirect style, represented speech and thought, or narrated monologue.
Space
Authors: Prieto Eric
Published: July 2019

Space is a fundamental, ineliminable dimension of existence, which manifests itself in every aspect of material, psychological, and social life. It is also a purely dimensional category, in the sense that it cannot be directly perceived. All representations, therefore, have a necessary spatial dimension and all representations of space require a medium (like objects and events) through which its presence can be made manifest. Moreover, spatial concepts are essential tools for rational thought, indeed, quite possibly a foundational element of rationality itself. Spatial metaphors consequently permeate every aspect of thinking, including topics that are not usually taken to have an intrinsically spatial dimension—from the spatialization of time that Zeno exploited and Henri Bergson complained about to the heavily spatialized vocabulary of information technology (with its computer domains, IP addresses, etc.). This combination of existential importance and cognitive adaptability helps to explain space’s enduring appeal as a focus of critical attention in literary studies but also the difficulty of the subject: the multifariousness and polysemy of spatial terms leads to much confusion between different modes of spatiality and much reliance on loose and often mixed metaphors. It is important, then, for literary critics and theorists to attend closely to the zones of overlap and confusion that might cloud spatial analyses in order to maximize the explanatory potential of the cluster of analytic tools that fall under the heading of spatial analysis. This has become especially apparent in the wake of the spatial turn that took place in literary theory and criticism toward the end of the 20th century.
Ekphrasis
Authors: Rippl Gabriele
Published: July 2019

Ekphrasis is a Greek term whose etymological meaning is “to speak out” or “to show in full.” Debates on ekphrasis go back to classical antiquity and Homer’s lines on Hephaestos making Achilles’ shield in Book 18 of the epic The Iliad (8th century bce). Ekphrasis was considered a mode of speaking capable of bringing absent things before the listener’s inner eye by aiming at enargeia, a vivid quality of language producing evidentia (evidence) and rousing emotions through lively, precise, and detailed verbal descriptions. Over the centuries, the term underwent a considerable narrowing-down of its original meaning and eventually, during the Second Sophistic, came to designate the description of works of art. However, ancient ekphrasis, in the broader sense of detailed and lively description, had a rich afterlife throughout the Middle Ages (e.g., in Geoffrey Chaucer), the Renaissance (e.g., in Shakespeare), Neoclassicism (in Joseph Addison’s essays and Gotthold Ephraim Lessing’s “Laocoön”), and even into the Romantic Age (e.g., in William Wordsworth and George Gordon Byron). In its narrower sense as verbal representation/evocation of or response to a work of art or visual object, it is a ubiquitous phenomenon in 19th-, 20th-, and 21st-century literature, be it poetry or narrative fiction. Many modernist, postmodernist, and post-postmodernist literary texts are replete with ekphrases, but these ekphrases very often question any mimetic or illusionist aesthetic and no longer exclusively follow the paragonal model: instead of competing with one another, ekphrastic word-image configurations are more adequately described as intermedial constellations and collaborations. As a pertinent feature of 20th- and 21st-century poetry and narrative fiction—examples are novels by Julian Barnes, Antonia Susan Byatt, Teju Cole, Siri Hustvedt, or Donna Tartt—ekphrasis has also attracted the attention of literary scholars and theoreticians of culture. Due to the many attempts to conceptualize and theorize ekphrasis, any attempt to give a simple definition will not suffice. In the 1980s and 1990s scholars such as Murray Krieger, William John Thomas Mitchell, and James Heffernan theorized ekphrasis: while Krieger saw ekphrasis as a symptom of the semiotic desire for the natural sign and Mitchell discussed ekphrasis within a paragonal framework of socio-cultural power relations, Heffernan defined ekphrasis as the verbal representation of visual representation. Included among the seminal concepts and definitions of ekphrasis in the early 21st century are approaches from phenomenology and cognitive poetics or new reception aesthetics, the digital humanities, postcolonial and transcultural studies, and the environmental humanities. By going beyond questions of representation that have dominated ekphrastic criticism for a long time, functions of ekphrasis, in particular socio-cultural and ethical functions, have gained new attention.
Late 19th-Century Periodical Print Culture in the US–Mexico Border Region
Authors: Kabalen de Bichara Donna M.
Published: July 2019

Hundreds of 19th-century newspapers and magazines published in the region of the US–Mexico border are housed in archival collections in Mexico and the United States, and they provide access to historical, cultural, and ideological perspectives involving two world spheres that are intimately connected. Archival collections in the following databases provide access to periodicals published in the United States as well as in Mexico: the Newspaper and Periodicals Collection at the National Autonomous University of Mexico; the Readex Collection of Hispanic American Newspapers, 1808–1980; the Nettie Lee Benson Library’s microfilmed collection of 19th-century independent newspapers; the digital collection of periodicals and magazines from the Capilla Alfonsina Biblioteca Universitaria and the Biblioteca Universitaria Raúl Rangel Frias, at the Universidad Autónoma de Nuevo León; and the EBSCO Arte Público Hispanic Historical Collections, Series 1 and 2. These collections house digitized and microfilmed newspapers that include those published in the US states of California, Arizona, Nevada, New Mexico, and Texas, as well as Mexican states such as Baja California, Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas. The region includes areas that share not only a physical border but also a cultural memory based on the effects of historical collisions that have contributed to the formation of new meanings regarding these world spheres that can be understood as two intersecting semiotic systems that exist as a continuum. The intersection of these spaces represents the transnational aspect of periodical print culture of the late 19th century that communicates worldviews that are semiotically and ideologically heterogeneous. Indeed, cultural spaces that exist in the borderland (or that symbolic space that forms a border or frontier in a cultural sense), are semiotic realities that unfold in unpredictable and indeterminate ways as a result of historical processes. Periodical print culture produced in the border region provides access to diverse social, cultural, political, and religious perspectives. Furthermore, the history of print culture involves a process of communication of both social and cultural history. As objects of study, borderland newspapers ultimately provide the basis for understanding the circulation of ideas.
Queerness in Latina/o/x Literature
Authors: González Liliana C.
Published: July 2019

To think about queerness in Latina/o/x literature necessarily entails a consideration of how queerness is regarded within Latina/o/x cultural expressions. But within popular Latino/a/x queer expressions, it would be difficult not to invoke the image of Mexican singer/ and composer Juan Gabriel and his unabashed gestures and sensuality. Juan Gabriel became a symbol of Latino/a queer subjectivity by “being” and “being seen” as “queer” but never explicitly “coming out” in the US mainstream sense. His unwillingness to conform to masculine gendered expectations within Mexican ranchera music and his reluctance to accept globalized gay modalities in many respects continues to embody the Latina/o racialized sexual experience in the United States. “Queerness” herein refers to a position of being queer in defiance of social norms within a given sociopolitical context rather than articulating a fixed state with a single understanding of what it means to be queer. As an expression with political impetus, queer has the capacity to mobilize resistance against sexual and gender norms, and is as much a political identity as it is a way to read society. The “ness” in “queerness” enables queer’s ability to modify conventional analysis and enhance readings of social relations as difference but, more important, as relations of power. That is, queerness as a relational mode of analysis unfolds the disruption of hierarchical binaries such as man/woman, masculine/feminine, and homosexual/heterosexual. The emergence of Chicana lesbian theory in the 1980s and queer of color critique in literary and cultural studies signaled a significant shift in thinking queer within Latina/o/x culture and thinking race, ethnicity, and class as integral to queer analysis, which had been previously overlooked by queer scholarship. As such, queerness has come to be understood as a critical lens that is capable of reading antagonizing associations not only against what is deemed as the sexual norm but precisely the way in which sexuality interacts with racialized, gendered, and class-based discourses. As a corpus, Latina/o literature reflects a range of topics that grapple with what it means to be a US Latina/o and to hold an ambiguous place in American racial and cultural politics and an often nostalgic yet contentious relationship with Latin America. Queerness, specifically in relation to Latina/o literature, is to imagine and create between and beyond these rigid delineations of gay and lesbian identity but at the same time breaking with assumptions of US Latina/o/x experience as exclusively heteronormative. In this sense, queerness within Latina/o/x literature imparts an unequivocal motion of being, thinking, and feeling against the grain of both Latina/o patriarchal literary traditions and the white US literary canon.
Cuadros, Gil
Authors: Pérez-Torres Rafael
Published: July 2019

Writer Gil Cuadros (1962–1996) composed an influential collection of short stories and poems, City of God (1994), that recounts the experiences of gay Chicano life in the age of AIDS. Learning he was HIV-positive after the death of his lover due to AIDS, he wrote to grapple with the enormity of his loss. Cuadros developed an aesthetic vocabulary for relating the richly complex experience of a seropositive queer Latinidad. Seeking to represent the unrepresentable, his work ranges from unflinchingly stark and minimalist to amorphously dark and surreal, exposing and exploring the cross-currents of race, violence, love, and sex ever haunted by an awareness of mortality. Concerned with making visible a queer literary chicanidad, Cuadros crafted poems and stories that are grounded in physicality and developed a vocabulary of sensation and sensuality. The stories reveal the body as a source of knowledge. While not the subject of extensive critical work, Cuadros’s writing is drawing more extensive attention. Earlier criticism focuses on the tension that Cuadros’s writing generates as it explores the racial and social ambivalence of queer Latinx desire. These analyses privilege the formation of queer mestizo subjectivity and read the body as a contested text. Following developments in queer theory, more recent critics foreground aesthetic and thematic ambiguity as part of a complicated dynamic between legibility and disciplinary social repression. Cuadros’s darkly ambivalent aesthetics perform what it means to be gay, Chicano, and living with AIDS, foregrounding new relations as aesthetics, politics, form, and content bleed into each other.
Cuban American Literatures
Authors: Ortiz Ricardo L.
Published: July 2019

Cuba’s historical relationship with the United States predates both countries’ emergence into full political sovereignty and consists of forms of political, economic, and cultural interaction and exchange that have intimately bound the two societies since well before the 19th century. The United States spent the 1800s emerging as an independent nation and increasingly as a regional power in the western hemisphere. Populations from smaller neighboring societies were emerging from colonial rule and often sought protection in the United States from colonial oppression, even as they saw the United States’ own imperial ambitions as a looming threat. Cuban-American literature therefore can trace its roots to a collection of key figures who sought refuge in the United States in the 19th century, but it did not flourish until well into the 20th when geopolitical conditions following World War II and extending into the Cold War era made the United States a natural destination for a significant population of Cubans fleeing Fidel Castro’s Communist Revolution. Most arrived first as refugees, then as exiles, and finally as immigrants settling into homes and making families and lives in their new country. This population has also produced a robust literary culture all its own with deep ties and important contributions to the greater US literary tradition. Cuban-American literary production has proliferated into the 21st century, exploring complex themes beyond national and cultural identity, including gender, sexuality, race, class, and ideology.