bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Synthesis of C1-Chiral THIQs with Imines in Isoquinoline Rings
Authors: Li Dan , Gao Wei , Chen Xiaochao
Published: July 2020

Tetrahydroisoquinoline (THIQ) scaffolds are important structural units that widely exist in a variety of natural alkaloids and synthetic analogues. Asymmetric synthesis of C1-chiral THIQ is of particular importance due to its significant pharmaceutical, agrochemical, and other biological activities, and the usually distinct bioactivities exhibited by the two enantiomers. In this review, we highlight the significant advances achieved in this field, present recent asymmetric synthesis with imines in isoquinoline rings ordered according to the sequence of various substrate types. New strategies could be inspired and more types of substrates need further development.

1 Introduction

2 Catalytic Asymmetric Reaction of Dihydroisoquinolines

2.1 Asymmetric Reactions of 3,4-Dihydroisoquinolines

2.2 Asymmetric Reactions of Dihydroisoquinolinium Salts

2.3 Asymmetric Reactions of C,N-Cyclic N′-Acyl Azomethine Imines

2.3.1 NED [3+2] Cycloaddition of C,N-Cyclic N′-Acyl Azomethine Imines

2.3.2 IED [3+2] Cycloaddition of C,N-Cyclic N′-Acyl Azomethine Imines

2.3.3 [3+3] Cycloaddition of C,N-Cyclic N′-Acyl Azomethine Imines

2.3.4 [4+3] Cycloaddition of C,N-Cyclic N′-Acyl Azomethine Imines

2.3.5 Asymmetric Addition Reactions to C,N-Cyclic N′-Acyl Azomethine Imines

2.4 Asymmetric Reactions of C,N-Cyclic Nitrones

3 Catalytic Asymmetric Mannich Reactions of Isoquinolines

4 Conclusions and Perspectives
Biocatalytic and Chemo-Enzymatic Approaches for the Synthesis of Heterocycles
Authors: Castagnolo Daniele , Zhao Fei , Masci Domiziana , Tomarelli Elena
Published: July 2020

Heterocycles are ubiquitous structures in nature and can be found in many drugs and chemicals. Biocatalysts, alone or in combination with other metal catalysts, can be exploited for the construction of various heterocyclic rings under mild reaction conditions. This Short Review highlights the recent advances in the development of biocatalytic and chemo-enzymatic methods for the synthesis of both aliphatic and aromatic heterocyclic rings.

1 Introduction

2 Synthesis of Aliphatic Heterocycles

2.1 Piperidines, Pyrrolidines and Piperazines

2.2 Other Nitrogen-Containing Aliphatic Heterocycles

2.3 Lactones and Lactams

2.4 Other Oxygen-Containing Heterocycles

3 Synthesis of Aromatic Heterocycles

3.1 Pyrroles, Pyridines and Pyrazines

3.2 Furans

3.3 Bicyclic Aromatic Heterocycles

4 Conclusion
Spatial reading: evaluative frameworks and the making of literary authority
Authors: Leypoldt Günter
Published: July 2020

This essay uses Charles Taylor’s theory of evaluative frameworks to solve a problem that has challenged literary theory and historiography for some time: how do we square the tension between the private uses and the public authority of reading? Taylor’s notion of strong value brings out literature’s often-overlooked similarities with religious-moral or civil-sacred domains, while his concept of weak value helps us to understand more mundane moods of purpose-rational reading. Combining the concept of evaluative frameworks with a socio-institutional account of literary authority, this essay sketches an alternative history of reading, with a focus on the shifting authority of “spatial reading” (defined as attention to formal and intertextual depth). Looking at developments from the 1780s to the present, I will show how the distinction between spatial and flat reading emerges in the eighteenth century, is transformed by the modernist institutionalization of high- and middlebrow notions of spatial form, and continues to provoke tensions between the civil sphere and the literary-artistic field (as the recent scandal around Peter Handke’s Nobel Prize attests).
Concentration behavior of solutions for fractional Schrödinger equations involving critical exponent
Authors: Li Quanqing , Teng Kaimin , Zhang Jian , Wang Wenbo
Published: July 2020

In this paper, we study the following fractional Schrödinger equation involving critical exponent ε2s(−Δ)su+V(x)u=|u|2s*−2u+λf(u), x∈RN, where 0 < s < 1, N > 2s, 2s*=2NN−2s, λ > 0, and f is a continuous superlinear but subcritical function. Under some suitable conditions, we obtain the concentration behavior of solutions for the above equation. This improves the results in the work of Shang and Zhang [Nonlinearity 27, 187–207 (2014)].
Current and future advancements for integrated perovskite/organic solar cells
Authors: Mandel Savannah
Published: July 2020

The future of integrated perovskite/organic solar cells may lie in the material choice and morphological control of the organic layer.
Symmetry and equivalence in teleparallel gravity
Authors: Coley A. A. , van den Hoogen R. J. , McNutt D. D.
Published: July 2020

In theories such as teleparallel gravity and its extensions, the frame basis replaces the metric tensor as the primary object of study. A choice of coordinate system, frame basis, and spin-connection must be made to obtain a solution from the field equations of a given teleparallel gravity theory. It is worthwhile to express solutions in an invariant manner in terms of torsion invariants to distinguish between different solutions. In this paper, we discuss the symmetries of teleparallel gravity theories, describe the classification of the torsion tensor and its covariant derivative, and define scalar invariants in terms of the torsion. In particular, we propose a modification of the Cartan–Karlhede algorithm for geometries with torsion (and no curvature or nonmetricity). The algorithm determines the dimension of the symmetry group for a solution and suggests an alternative frame-based approach to calculating symmetries. We prove that the only maximally symmetric solution to any theory of gravitation admitting a non-zero torsion tensor is Minkowski space. As an illustration, we apply the algorithm to six particular exact teleparallel geometries. From these examples, we notice that the symmetry group of the solutions of a teleparallel gravity theory is potentially smaller than their metric-based analogs in general relativity.
Relaxation in a phase-separating two-dimensional active matter system with alignment interaction
Authors: Chakraborty Saikat , Das Subir K.
Published: July 2020

Via computer simulations, we study kinetics of pattern formation in a two-dimensional active matter system. Self-propulsion in our model is incorporated via the Vicsek-like activity, i.e., particles have the tendency of aligning their velocities with the average directions of motion of their neighbors. In addition to this dynamic or active interaction, there exists passive inter-particle interaction in the model for which we have chosen the standard Lennard-Jones form. Following quenches of homogeneous configurations to a point deep inside the region of coexistence between high and low density phases, as the systems exhibit formation and evolution of particle-rich clusters, we investigate properties related to the morphology, growth, and aging. A focus of our study is on the understanding of the effects of structure on growth and aging. To quantify the latter, we use the two-time order-parameter autocorrelation function. This correlation, as well as the growth, is observed to follow power-law time dependence, qualitatively similar to the scaling behavior reported for passive systems. The values of the exponents have been estimated and discussed by comparing with the previously obtained numbers for other dimensions as well as with the new results for the passive limit of the considered model. We have also presented results on the effects of temperature on the activity mediated phase separation.
Water mediated electron attachment to nucleobases: Surface-bound vs bulk solvated electrons
Authors: Mukherjee Madhubani , Tripathi Divya , Dutta Achintya Kumar
Published: July 2020

We have presented a mechanism for electron attachment to solvated nucleobases using accurate wave-function based hybrid quantum/classical (QM/MM) simulations and uracil as a test case. The initial electron attached state is found to be localized in the bulk water, and this water-bound state acts as a doorway to the formation of the final nucleobase bound state. The electron transfer from water to uracil takes place because of the mixing of electronic and nuclear degrees of freedom. The water molecules around the uracil stabilize the uracil-bound anion by creating an extensive hydrogen-bonding network and accelerate the rate of electron attachment to uracil. The complete transfer of the electron from water to the uracil occurs in a picosecond time scale, which is consistent with the experimentally observed rate of reduction of nucleobases in the presence of water. The degree of solvation of the aqueous electron can lead to a difference in the initial stabilization of the uracil-bound anion. However, the anions formed due to the attachment of both surface-bound and bulk-solvated electrons behave similarly to each other at a longer time scale.
Inertial effects on trapped active matter
Authors: Gutierrez-Martinez Luis L. , Sandoval Mario
Published: July 2020

In this work, the dynamics of inertial (mass and moment of inertia) active Brownian particles trapped in a harmonic well is studied. This scenario has seen success when characterizing soft passive and active overdamped matter. Motivated by the variety of applications of this system, we analytically find the effect of translational and rotational inertia on the mean-square displacement (MSD), mean-square speed (MSS), swim, Reynolds, and total pressures of a system of inertial active Brownian particles subject to a weak and a strong harmonic trap. Following a Langevin formalism, we explicitly find that as inertia grows, the systems’ MSD and total pressure are enhanced, but its MSS and swim pressure decrease. The use of Langevin dynamics simulations enables us to observe that as inertia grows, inertial active matter under a strong trap no longer “condensates” at the “border” of the trap, but it rather tends to uniformly spread in space. Our analytical results are also numerically validated.
Configurational thermodynamics of a 1/2〈111〉 screw dislocation core in Mo–W solid solutions using cluster expansion
Authors: Casillas-Trujillo Luis , Alling Björn
Published: July 2020

In this work, we have developed a methodology to obtain an ab initio cluster expansion of a system containing a dislocation and studied the effect of configurational disorder on the 1/2〈111〉 screw dislocation core structure in disordered Mo1−xWx alloys. Dislocation cores control the selection of glide planes, cross slip, and dislocation nucleation. Configurational disorders in alloys can impact the dislocation core structure and affect dislocation mobility. For our calculations, we have used a quadrupolar periodic array of screw dislocation dipoles and obtained the relaxed structures and energies using density functional theory. We have obtained the dislocation core structure as a function of composition and the interaction energies of solutes with the dislocation as a function of position with respect to the core. With these energies, we performed mean-field calculations to assess segregation toward the core. Finally, with the calculated energies of 1848 alloy configurations with different compositions, we performed a first principle cluster expansion of the configurational energetics of Mo1−xWx solid solutions containing dislocations.
Surface-state-mediated interfacial charge dynamics between carbon dots and ZnO toward highly promoting photocatalytic activity
Authors: Long Liyuan , Wu Qifan , Chao Qingyuan , Dong Yi , Wu Liqian , Zhang Qizhen , Zhou Yong , Wang Dunhui
Published: July 2020

Design of hybrid systems for photocatalytic application tends to be restricted by lacking interfacial coupling and fast charge recombination in the body competing with interface dynamics. In this work, the reduced carbon dots (rCDs) with numerous surface hydroxyl groups were deliberately anchored onto flower-like ZnO spheres with a highly exposed surface area to form heterointerfaces with sufficient interfacial electronic coupling. The incorporated rCDs evidently promote the light harvesting and charge separation of the binary hybrid system, resulting in highly enhanced photocatalytic Cr(VI) degradation performance. Ultrafast time-resolved spectra reveal that the surface C—OH bonds of rCDs play a crucial role at the heterointerfaces to regulate the charge dynamics. The long-lived surface C—OH states not only act as electron donors but also become electron mediators to rapidly capture the photoelectrons from the intrinsic state in the time-domain of 1 ps and induce a much longer lifetime for achieving highly efficient photoelectron injection from rCDs to ZnO. These results manifest that rCDs can be a promising photosensitizer to apply in photocatalytic pollutant treatment and energy conversion fields.
Spin polarization as an electronic cooperative effect
Authors: Ben Amor Nadia , Noûs Camille , Trinquier Georges , Malrieu Jean-Paul
Published: July 2020

Taking as an example the simple CH3 radical, this work demonstrates the cooperative character of the spin-polarization phenomenon of the closed-shell core in free radicals. Spin polarization of CH σ bonds is not additive here, as spin polarization of one bond enhances that of the next bond. This cooperativity is demonstrated by a series of configuration interaction calculations converging to the full valence limit and is rationalized by analytic developments. The same phenomenon is shown to take place in those diradicals where spin polarization plays a major role, as illustrated in square planar carbo-cyclobutadiene C12H4. The treatment of cooperativity represents a challenge for usual post-Hatree–Fock methods.
About electron transfer over long distances with tunable sub/supersonic velocities
Authors: Velarde M. G. , Chetverikov A. P. , Launay J.-P. , Ebeling W. , Wilson E. G.
Published: July 2020

Provided in this paper is a theory of long-range electron transfer with near sound (supersonic or subsonic) velocity along one-dimensional crystal lattices. The theory represents the development of an earlier work by introducing Marcus formulation. To illustrate its application to a realistic case, the theory is used to offer an explanation of two puzzling observations made by Donovan and Wilson in transient photoconduction experiments with non-dopable perfectly crystalline polydiacetylene crystals in the presence of an electric field: transport velocity value close to sound velocity being independent of field for four orders of magnitude of field (102 V/m–106 V/m) and, in the low field values, an ultra-high mobility greater than 20 m2/V s. We also study factors eventually leading to lowering of the transport velocity.
The electrocaloric effect in doped hafnium oxide: Comparison of direct and indirect measurements
Authors: Mart C. , Kämpfe T. , Czernohorsky M. , Eßlinger S. , Kolodinski S. , Wiatr M. , Weinreich W. , Eng L. M.
Published: July 2020

The accurate determination of electrocaloric coefficients in nanometer-thin, polycrystalline doped HfO2 is challenging and has led to very different values reported in the literature. Here, we apply two different methods in order to compare and analyze reversible and irreversible or metastable contributions to the electrocaloric effect. The indirect method is based on temperature-dependent ferroelectric hysteresis characteristics. Furthermore, we apply a direct method, where electrocaloric temperature variations are observed using a specialized test structure. A comparison of both methods reveals that the indirect method dramatically overestimates the response due to thermal fatigue effects, which are caused by the migration of charged defects to the electrode interfaces. The partial transition to the antiferroelectric-like tetragonal phase is not immediately reversed to the polar Pca21 phase upon cooling. An electrocaloric coefficient of −107 μC m−2 K−1 is determined for a 20 nm thick Si-doped HfO2 film with the direct method, which corresponds to a ΔT of 4.4 K.
Low-frequency Raman spectrum of 2D layered perovskites: Local atomistic motion or superlattice modes?
Authors: Dahod Nabeel S. , France-Lanord Arthur , Paritmongkol Watcharaphol , Grossman Jeffrey C. , Tisdale William A.
Published: July 2020

We report the low-frequency Raman spectrum (ω = 10 cm−1–150 cm−1) of a wide variety of alkylammonium iodide based 2D lead halide perovskites (2D LHPs) as a function of A-site cation (MA = methylammonium and FA = formamidinium), octahedral layer thickness (n = 2–4), organic spacer chain length (butyl-, pentyl-, hexyl-), and sample temperature (T = 77 K–293 K). Using density functional theory calculations under the harmonic approximation for n = 2 BA:MAPbI, we assign several longitudinal/transverse optical phonon modes between 30 cm−1 and 100 cm−1, the eigendisplacements of which are analogous to that observed previously for octahedral twists/distortions in bulk MAPbI. Additionally, we propose an alternative assignment for low-frequency modes below this band (<30 cm−1) as zone-folded longitudinal acoustic phonons corresponding to the periodicity of the entire layered structure. We compare measured spectra to predictions of the Rytov elastic continuum model for zone-folded dispersion in layered structures. Our results are consistent across the various 2D LHPs studied herein, with energetic shifts of optical phonons corresponding to microscopic structural differences between materials and energetic shifts of acoustic phonons according to changes in the periodicity and elastic properties of the perovskite/organic subphases. This study highlights the importance of both the local atomic order and the superlattice structure on the vibrational properties of layered 2D materials.
Nanoantennas embedded in zinc oxide for second harmonic generation enhancement
Authors: Volmert Ruth , Weber Nils , Meier Cedrik
Published: July 2020

Plasmonic nanoantennas for visible and infrared radiation strongly improve the interaction of light with the matter on the nanoscale due to their strong near-field enhancement. In this study, we investigate a double-resonant plasmonic nanoantenna, which makes use of plasmonic field enhancement, enhanced outcoupling of second harmonic light, and resonant lattice effects. Using this design, we demonstrate how the efficiency of second harmonic generation can be increased significantly by fully embedding the nanoantennas into nonlinear dielectric material ZnO, instead of placing them on the surface. Investigating two different processes, we found that the best fabrication route is embedding the gold nanoantennas in ZnO using an MBE overgrowth process where a thin ZnO layer was deposited on nanoantennas fabricated on a ZnO substrate. In addition, second harmonic generation measurements show that the embedding leads to an enhancement compared to the emission of nanoantennas placed on the ZnO substrate surface. These promising results facilitate further research to determine the influence of the periodicity of the nanoantenna arrangement of the resulting SHG signal.
Spectral neural network potentials for binary alloys
Authors: Zagaceta David , Yanxon Howard , Zhu Qiang
Published: July 2020

In this work, we present a numerical implementation to compute the atom-centered descriptors introduced by Bartok et al. [Phys. Rev. B 87, 184115 (2013)] based on the harmonic analysis of the atomic neighbor density function. Specifically, we focus on two types of descriptors, the smooth SO(3) power spectrum with the explicit inclusion of a radial basis and the SO(4) bispectrum obtained through mapping the radial component onto a polar angle of a four dimensional hypersphere. With these descriptors, various interatomic potentials for binary Ni–Mo alloys are obtained based on linear and neural network regression models. Numerical experiments suggest that both descriptors produce similar results in terms of accuracy. For linear regression, the smooth SO(3) power spectrum is superior to the SO(4) bispectrum when a large band limit is used. In neural network regression, better accuracy can be achieved with even less number of expansion components for both descriptors. As such, we demonstrate that spectral neural network potentials are feasible choices for large scale atomistic simulations.
Surmounting potential barriers: Hydrodynamic memory hedges against thermal fluctuations in particle transport
Authors: Seyler Sean L. , Pressé Steve
Published: July 2020

Recently, trapped-particle experiments have probed the instantaneous velocity of Brownian motion revealing that, at early times, hydrodynamic history forces dominate Stokes damping. In these experiments, nonuniform particle motion is well described by the Basset–Boussinesq–Oseen (BBO) equation, which captures the unsteady Basset history force at a low Reynolds number. Building off of these results, earlier we showed that, at low temperature, BBO particles could exploit fluid inertia in order to overcome potential barriers (generically modeled as a tilted washboard), while its Langevin counter-part could not. Here, we explore the behavior of neutrally buoyant BBO particles at finite temperature for moderate Stokes damping. Remarkably, we find that the transport of particles injected into a bumpy potential with sufficiently high barriers can be completely quenched at intermediate temperatures, whereas itinerancy may be possible above and below that temperature window. This effect is present for both Langevin and BBO dynamics, though these occur over drastically different temperature ranges. Furthermore, hydrodynamic memory mitigates these effects by sustaining initial particle momentum, even in the difficult intermediate temperature regime.
Mobility of large ions in water
Authors: Samanta Tuhin , Matyushov Dmitry V.
Published: July 2020

Mobility of ions in polar liquids is diminished when the ionic charge is increased. This phenomenon, known as dielectric friction, is caused by the retarded response of the liquid’s dipoles to the charge movement. Linear response theories predict linear scaling of the inverse diffusion coefficient with the squared ionic charge. This prediction is analyzed here by molecular dynamics simulations of model ions with fractional charge q in the simple point charge water and by microscopic theory formulated in terms of the dynamic electric-field susceptibility of the solvent. The results of the analytical theory, and of its dielectric continuum limit, are in excellent agreement with simulations at sufficiently small charges q < 0.5 when linear response holds. At higher ionic charges, the hydration shell contracts, resulting in deviations from linear response in both static and dynamic properties of the electric field produced by water at the ion. Nevertheless, dielectric friction continues to rise in the nonlinear regime, resulting in an overall factor of 3.7 slower diffusion upon placing a single charge q = 1 on the solute. An approximately linear scaling of the inverse diffusion coefficient with the squared ionic charge comes from a mutual compensation between nonlinear solvation and correlations between non-electrostatic and electrostatic forces. Mobility of common electrolyte ions in water is predicted to occur in the regime of nonlinear dielectric friction.
External cavity terahertz quantum cascade laser with a metamaterial/graphene optoelectronic mirror
Authors: Almond Nikita W. , Qi Xiaoqiong , Degl'Innocenti Riccardo , Kindness Stephen J. , Michailow Wladislaw , Wei Binbin , Braeuninger-Weimer Philipp , Hofmann Stephan , Dean Paul , Indjin Dragan , Linfield Edmund H. , Davies A. Giles , Rakić Aleksandar D. , Beere Harvey E. , Ritchie David A.
Published: July 2020

Photonic engineering of the terahertz emission from a quantum cascade laser (QCL) is fundamental for the exploitation of this unique source in a myriad of applications where it can be implemented, such as spectroscopy, imaging, and sensing. Active control of the frequency, power, polarization, and beam profile has been achieved through a variety of approaches. In particular, the active control of the emitted frequency, which is difficult to determine a priori, has been achieved through the integration of a photonic structure and/or by using external cavity arrangements. In this work, an external cavity arrangement, which implements a metamaterial/graphene optoelectronic mirror as an external feedback element, is proposed and demonstrated. The reflectivity and dispersion properties of the external active mirror were tuned via electrostatically gating graphene. It was possible to electronically reproduce the mode-switch occurring in a QCL emitting ∼2.8 THz by mechanically changing the external cavity length formed by an Au mirror. The external cavity arrangement was investigated and described in the framework of the self-mixing theory. These results open a way for the all-electronic engineering of the QCL emission by the use of a fast reconfigurable external mirror. This approach can uniquely address both power and frequency control, with ∼100 MHz reconfiguration speeds, using an integrated external element. Furthermore, the metamaterial/graphene mirror's strong dispersive properties might be implemented for the active mode locking of THz QCLs. Finally, this approach offers a unique opportunity to study the laser dynamics and mode competition in THz QCLs in the self-mixing feedback regime.
Nonlinear losses in magnon transport due to four-magnon scattering
Authors: Hula Tobias , Schultheiss Katrin , Buzdakov Aleksandr , Körber Lukas , Bejarano Mauricio , Flacke Luis , Liensberger Lukas , Weiler Mathias , Shaw Justin M. , Nembach Hans T. , Fassbender Jürgen , Schultheiss Helmut
Published: July 2020

We report on the impact of nonlinear four-magnon scattering on magnon transport in microstructured Co25Fe75 waveguides with low magnetic damping. We determine the magnon propagation length with microfocused Brillouin light scattering over a broad range of excitation powers and detect a decrease in the attenuation length at high powers. This is consistent with the onset of nonlinear four-magnon scattering. Hence, it is critical to remain in the linear regime when deriving damping parameters from the magnon propagation length. Otherwise, the intrinsic nonlinearity of magnetization dynamics may lead to a misinterpretation of magnon propagation lengths and, thus, to incorrect values of the magnetic damping of the system.
In-situ fabrication and transport properties of (111) Y2Ir2O7 epitaxial thin film
Authors: Liu Xiaoran , Wen Fangdi , Karapetrova E. , Kim J.-W. , Ryan P. J. , Freeland J. W. , Terilli M. , Wu T.-C. , Kareev M. , Chakhalian J.
Published: July 2020

We report on the successful fabrication of (111) oriented thin films of pyrochlore iridate Y2Ir2O7 by means of solid phase epitaxy. Essentially, we developed an entirely in situ annealing protocol, which is superior to the conventional ex-situ routine that requires multi-hour annealing to stabilize the proper pyrochlore structure. The morphological quality of the films has been confirmed by x-ray diffraction, reflectivity, and reciprocal space mapping, demonstrating their high crystallinity with a pure pyrochlore phase and an expected epitaxial relation to the substrate. Strikingly, below the magnetic phase transition, the temperature dependence of resistivity shows a power-law behavior with the power exponent of ∼3/2, characteristic of a Weyl semimetal in the presence of impurities and electron–electron correlations. Below 10 K, the magneto-transport measurements reveal the emergence of a non-saturated negative magnetoresistance up to 9 T with a small “valley” around zero field. These findings are further interpreted in relation to the weak anti-localization effect and the non-collinear antiferromagnetic ordering on the Ir sublattice.
Spatial ecology of an endangered carnivore, the Pilbara northern quoll
Authors: Hernandez-Santin Lorna , Henderson Melinda , Molloy Shaun W. , Dunlop Judy A. , Davis Robert A.
Published: July 2020

Understanding the spatial requirements of a species allows one to tailor actions that can help protect species and their habitats. We investigated the spatial needs of the endangered northern quoll (Dasyurus hallucatus) in the Pilbara. We analysed field data based on GPS-telemetry or a combination of GPS and VHF telemetry for 11 northern quolls with data collected over two week periods. Using MCP and Kernel methods, we found average short-term ranges of 193 ha and 115 ha for males, and for the only female with reliable data the estimates were 34 ha and 23 ha, respectively, with Kernel-based core areas that were between five and three times smaller for males and the female, respectively. We found support for our hypothesis that ranges differ between seasons, but with a seasonal trend that was different from that expected. The ranges of males during the premating/mating season were smaller than during the pouch-young season. Our study provides the first detailed attempt to define and understand short-term movement behaviour of the Pilbara northern quoll. The information derived from our study can help to increase the accuracy of predictive outputs and better inform habitat prioritisation and conservation management of the Pilbara northern quoll population.
No room to move: bat response to rainforest expansion into long-unburnt eucalypt forest
Authors: Baker Andrew G. , Catterall Claudia , Benkendorff Kirsten , Law Bradley
Published: July 2020

The expansion of rainforest trees into long-unburnt open forests is widespread globally, including in high-rainfall regions of eastern Australia. Increased tree density can reduce insectivorous bat activity and species richness by constraining echolocation and foraging success. Yet it is unknown whether sclerophyll and rainforest trees differ in their effects on open forest bat communities. We sampled insectivorous bats and nocturnal flying insects at two heights (understorey, canopy) in dry sclerophyll forest of eastern Australia with contrasting fire histories and levels of rainforest pioneer invasion. We found that both time since fire and functional identity of midstorey trees influenced the local bat community, whereas insect biomass had little effect. Long-unburnt forests with a rainforest pioneer midstorey had lower bat activity (63% lower) and species richness (35% lower) than recently burnt forests with a more open midstorey. Bat species richness also declined beneath the dense sclerophyll midstorey in long-unburnt forests, although was unaffected in the canopy above. Strong negative correlations between rainforest tree density and bat community activity and richness indicate that rainforest trees, in contrast with sclerophyll trees, exert additional negative control over open forest bat communities. Our results show that habitat suitability for clutter-intolerant bats declined well before the often-recommended maximum fire-intervals for dry open forest, providing evidence of an upper threshold for fauna conservation in rainforest-invaded open forests. To conserve bat communities in dry open forests vulnerable to rainforest invasion, fire should occur with sufficient frequency to prevent rainforest pioneers developing a dense midstorey that displaces clutter-intolerant bats.
Algorithms as discrimination detectors
Authors: Kleinberg Jon , Ludwig Jens , Mullainathan Sendhil , Sunstein Cass R.
Published: July 2020

Preventing discrimination requires that we have means of detecting it, and this can be enormously difficult when human beings are making the underlying decisions. As applied today, algorithms can increase the risk of discrimination. But as we argue here, algorithms by their nature require a far greater level of specificity than is usually possible with human decision making, and this specificity makes it possible to probe aspects of the decision in additional ways. With the right changes to legal and regulatory systems, algorithms can thus potentially make it easier to detect—and hence to help prevent—discrimination.
Biased hate crime perceptions can reveal supremacist sympathies
Authors: Leander N. Pontus , Kreienkamp Jannis , Agostini Maximilian , Stroebe Wolfgang , Gordijn Ernestine H. , Kruglanski Arie W.
Published: July 2020

Significance

Some mass shooters openly express intent to target ethnic and racial minorities, but members of the public still do not agree on whether the gunman was indeed motivated by prejudice and/or hatred. The present research finds that members of a dominant majority often express uncertainty about hate crimes when they privately sympathize with the perpetrator’s cause; specifically, aggrieved members of a dominant majority do not want to acknowledge the victimhood of minority groups. The tendency to deemphasize hate crimes can be traced back to each individual’s own frustrations with society and resentment of other groups. Ultimately, the same general process that explains support for violent extremism, around the world, may also explain supremacist sympathies in modern Western democracies.
Machine learning uncovers the most robust self-report predictors of relationship quality across 43 longitudinal couples studies
Authors: Joel Samantha , Eastwick Paul W. , Allison Colleen J. , Arriaga Ximena B. , Baker Zachary G. , Bar-Kalifa Eran , Bergeron Sophie , Birnbaum Gurit E. , Brock Rebecca L. , Brumbaugh Claudia C. , Carmichael Cheryl L. , Chen Serena , Clarke Jennifer , Cobb Rebecca J. , Coolsen Michael K. , Davis Jody , de Jong David C. , Debrot Anik , DeHaas Eva C. , Derrick Jaye L. , Eller Jami , Estrada Marie-Joelle , Faure Ruddy , Finkel Eli J. , Fraley R. Chris , Gable Shelly L. , Gadassi-Polack Reuma , Girme Yuthika U. , Gordon Amie M. , Gosnell Courtney L. , Hammond Matthew D. , Hannon Peggy A. , Harasymchuk Cheryl , Hofmann Wilhelm , Horn Andrea B. , Impett Emily A. , Jamieson Jeremy P. , Keltner Dacher , Kim James J. , Kirchner Jeffrey L. , Kluwer Esther S. , Kumashiro Madoka , Larson Grace , Lazarus Gal , Logan Jill M. , Luchies Laura B. , MacDonald Geoff , Machia Laura V. , Maniaci Michael R. , Maxwell Jessica A. , Mizrahi Moran , Muise Amy , Niehuis Sylvia , Ogolsky Brian G. , Oldham C. Rebecca , Overall Nickola C. , Perrez Meinrad , Peters Brett J. , Pietromonaco Paula R. , Powers Sally I. , Prok Thery , Pshedetzky-Shochat Rony , Rafaeli Eshkol , Ramsdell Erin L. , Reblin Maija , Reicherts Michael , Reifman Alan , Reis Harry T. , Rhoades Galena K. , Rholes William S. , Righetti Francesca , Rodriguez Lindsey M. , Rogge Ron , Rosen Natalie O. , Saxbe Darby , Sened Haran , Simpson Jeffry A. , Slotter Erica B. , Stanley Scott M. , Stocker Shevaun , Surra Cathy , Ter Kuile Hagar , Vaughn Allison A. , Vicary Amanda M. , Visserman Mariko L. , Wolf Scott
Published: July 2020

Significance

What predicts how happy people are with their romantic relationships? Relationship science—an interdisciplinary field spanning psychology, sociology, economics, family studies, and communication—has identified hundreds of variables that purportedly shape romantic relationship quality. The current project used machine learning to directly quantify and compare the predictive power of many such variables among 11,196 romantic couples. People’s own judgments about the relationship itself—such as how satisfied and committed they perceived their partners to be, and how appreciative they felt toward their partners—explained approximately 45% of their current satisfaction. The partner’s judgments did not add information, nor did either person’s personalities or traits. Furthermore, none of these variables could predict whose relationship quality would increase versus decrease over time.
Cumulative mechanism of several major imatinib-resistant mutations in Abl kinase
Authors: Hoemberger Marc , Pitsawong Warintra , Kern Dorothee
Published: July 2020

Significance

One obstacle for the prolonged success of the wonder drug imatinib in leukemia has been the emergence of resistance mutations within the Abl kinase domain. Here, we elucidate the molecular mechanism for resistance of three major mutations in patients treated with imatinib. Unpredictably, the single-site resistance mutations act via a cumulative effect of an only modest decrease in drug affinity, combined with an increase in enzyme activity and altered substrate affinity/cooperativity. Strikingly, this combination indeed leads to at least an order-of-magnitude higher IC
50
values for imatinib, but only under cellular ATP concentrations. Our findings settle a longstanding controversy, and concepts found here are likely to play a role in drug resistance in other targets.
Aggresomal sequestration and STUB1-mediated ubiquitylation during mammalian proteaphagy of inhibited proteasomes
Authors: Choi Won Hoon , Yun Yejin , Park Seoyoung , Jeon Jun Hyoung , Lee Jeeyoung , Lee Jung Hoon , Yang Su-A , Kim Nak-Kyoon , Jung Chan Hoon , Kwon Yong Tae , Han Dohyun , Lim Sang Min , Lee Min Jae
Published: July 2020

Significance

The ubiquitin–proteasome system and autophagy are two major intracellular proteolytic pathways, and both remove misfolded and proteotoxic proteins from eukaryotic cells. This study describes the detailed regulatory pathway of proteasome degradation by autophagy for its own quality control. We discovered that a portion of inhibited proteasomes is actively sequestered into the aggresome, an insoluble fraction of the mammalian cell. The aggresome functions as a triage point for proteasome recovery and autophagic degradation. This mainly distinguishes proteasome quality control in mammals from that in other organisms. STUB1/CHIP E3 Ub ligase has a critical role in targeting inhibited proteasomes into the aggresome. These results provide strong insights into protein catabolism in various pathological conditions originating from impaired proteasomes.
A genome-wide case-only test for the detection of digenic inheritance in human exomes
Authors: Kerner Gaspard , Bouaziz Matthieu , Cobat Aurélie , Bigio Benedetta , Timberlake Andrew T. , Bustamante Jacinta , Lifton Richard P. , Casanova Jean-Laurent , Abel Laurent
Published: July 2020

Significance

Despite a growing number of reports of rare disorders not fully explained by monogenic lesions, digenic inheritance has been reported for only 54 diseases to date. The very few existing methods for detecting gene × gene interactions from next-generation sequencing data were generally examined in rare-variant association studies with limited simulation analyses for short genomic regions, under a case-control design. We describe a case-only approach designed specifically to search for digenic inheritance, which avoids recruitment of controls. We show, through both extensive simulation studies on real whole-exome sequencing datasets and application to a real example of craniosynostosis, that our method is robust and powerful for the genome-wide identification of digenic lesions.
Hedgehog signaling is necessary and sufficient to mediate craniofacial plasticity in teleosts
Authors: Navon Dina , Male Ira , Tetrault Emily R. , Aaronson Benjamin , Karlstrom Rolf O. , Albertson R. Craig
Published: July 2020

Significance

Phenotypic plasticity has emerged as an important concept in evolutionary biology. It is thought to contribute to an organism’s ability to adapt to environmental change within a single generation, which may facilitate survival and increase fitness. Furthermore, plasticity has the potential to bias the direction and/or speed of evolution by changing patterns of phenotypic variation and exposing new genetic variation to selection (i.e., flexible stem evolution). Our understanding of this important phenomenon is incomplete owing to limited knowledge of the molecular underpinnings of reaction norm evolution. Using the teleost feeding apparatus as a model, we explore this open question and show that the Hh signaling pathway underlies the ability of this structure to respond plastically to alternate feeding regimes.
The hemispheric contrast in cloud microphysical properties constrains aerosol forcing
Authors: McCoy Isabel L. , McCoy Daniel T. , Wood Robert , Regayre Leighton , Watson-Parris Duncan , Grosvenor Daniel P. , Mulcahy Jane P. , Hu Yongxiang , Bender Frida A.-M. , Field Paul R. , Carslaw Kenneth S. , Gordon Hamish
Published: July 2020

Significance

Enhancement of aerosol that can nucleate cloud droplets increases the droplet number concentration and albedo of clouds. This increases the amount of sunlight reflected to space. Uncertainty in how aerosol−cloud interactions over the industrial period have increased planetary albedo by this mechanism leads to significant uncertainty in climate projections. Our work presents a method for observationally constraining the change in albedo due to anthropogenic aerosol emissions: a hemispheric difference in remotely sensed cloud droplet number between the pristine Southern Ocean (a preindustrial proxy) and the polluted Northern Hemisphere. Application of this constraint to climate models reduces the range of estimated albedo change since industrialization and suggests current models underpredict cloud droplet number concentration in the preindustrial era.
Elevated energy requirement of cone photoreceptors
Authors: Ingram Norianne T. , Fain Gordon L. , Sampath Alapakkam P.
Published: July 2020

Significance

From recent measurements of mammalian cone physiology, we have calculated cone ATP utilization in darkness and in the light. We show that single cones consume ATP at a much higher rate than single rods, a difference that is greatly increased during the day. This high metabolic rate is especially prominent in the primate fovea, which may make this part of the human eye particularly sensitive to decreases in glucose uptake or other metabolic alterations.
The moral barrier effect: Real and imagined barriers can reduce cheating
Authors: Zhao Li , Zheng Yi , Compton Brian J. , Qin Wen , Zheng Jiaxin , Fu Genyue , Lee Kang , Heyman Gail D.
Published: July 2020

Significance

Dishonest behavior undermines the trust that is required for strong relationships and institutions. The present study offers an approach to discouraging dishonesty that involves a subtle environmental intervention. Specifically, we test the moral barrier hypothesis, which posits that moral violations can be inhibited by the introduction of spatial boundaries, including ones that do not physically impede the act of transgressing. We found that both real and imagined barriers, when placed strategically, were able to reduce cheating among 5- to 6-y-olds. These findings link spatial cognition to moral behavior and show that even seemingly unremarkable features of children’s environments can nudge them to act honestly.
Mechanistic basis of substrate–O2coupling within a chitin-active lytic polysaccharide monooxygenase: An integrated NMR/EPR study
Authors: Courtade Gaston , Ciano Luisa , Paradisi Alessandro , Lindley Peter J. , Forsberg Zarah , Sørlie Morten , Wimmer Reinhard , Davies Gideon J. , Eijsink Vincent G. H. , Walton Paul H. , Aachmann Finn L.
Published: July 2020

Significance

Lytic polysaccharide monooxygenases (LPMOs) have unique catalytic centers, at which a single copper catalyzes the oxidative cleavage of a glycosidic bond. The mechanism by which LPMOs activate molecular oxygen is key to understanding copper (bio)catalysis but remains poorly understood, largely because the insoluble and heterogeneous nature of LPMO substrates precludes the use of usual laboratory techniques. Using an integrated NMR/EPR approach, we have unraveled structural and electronic details of the interactions of an LPMO fromBacillus licheniformisand β-chitin. EPR spectroscopy on uniformly isotope15N-labeled63Cu(II)-LPMO provided insight into substrate-driven rearrangement of the copper coordination sphere that predisposes the enzyme for O2activation.
Randomized trial shows healthcare payment reform has equal-sized spillover effects on patients not targeted by reform
Authors: Einav Liran , Finkelstein Amy , Ji Yunan , Mahoney Neale
Published: July 2020

Significance

In the US healthcare system, most medical providers treat patients covered by multiple insurers. As a result, changes in the way one health insurer pays for medical services could, by changing provider behavior, spill over onto patients covered by other insurers. In this article, we present evidence of such spillovers in the context of a large Medicare payment reform that was implemented in some areas of the country but not in others, via random assignment. We show that the payment reform had effects of similar magnitude on both the directly covered patients and on patients covered by other insurers. We discuss implications of these findings for our interpretation of existing estimates as well as for the design of healthcare policy.
Two distinct amphipathic peptide antibiotics with systemic efficacy
Authors: Lakshmaiah Narayana Jayaram , Mishra Biswajit , Lushnikova Tamara , Wu Qianhui , Chhonker Yashpal S. , Zhang Yingxia , Zarena D. , Salnikov Evgeniy S. , Dang Xiangli , Wang Fangyu , Murphy Caitlin , Foster Kirk W. , Gorantla Santhi , Bechinger Burkhard , Murry Daryl J. , Wang Guangshun
Published: July 2020

Significance

It is the dream of many scientists to develop antimicrobial peptides (AMPs) into potent antibiotics to combat resistant pathogens and their biofilms. However, the success is low due to limited knowledge on peptide design. Natural AMPs are diverse in sequence, activity, and source. We found a linear relationship between the averaged contents of arginine (R) and hydrophobic amino acids (Pho) of over 3,000 AMPs in the current Antimicrobial Peptide Database (
http://aps.unmc.edu/AP
). Based on this R–Pho relationship, we identified a peptide template and designed two representative amphipathic peptides with distinct structures and activities. Remarkably, horine and verine showed systemic efficacy in mice, but no nephrotoxicity to rodents. Our study advances peptide design and provides two antibiotics to combat drug-resistant pathogens.
Cxcl9l and Cxcr3.2 regulate recruitment of osteoclast progenitors to bone matrix in a medaka osteoporosis model
Authors: Phan Quang Tien , Tan Wen Hui , Liu Ranran , Sundaram Sudha , Buettner Anita , Kneitz Susanne , Cheong Benedict , Vyas Himanshu , Mathavan Sinnakaruppan , Schartl Manfred , Winkler Christoph
Published: July 2020

Significance

Bone remodeling requires a balanced interplay of osteoblasts and osteoclasts. While the intercellular signaling that triggers bone cell differentiation is well understood, it remains unclear how bone progenitor cells are recruited to remodeling sites. Various chemokines are upregulated under osteoporotic conditions. However, whether they are involved in progenitor recruitment or instead have inflammatory roles is unknown. Here we used a medaka fish osteoporosis model to identify the chemokine ligand Cxcl9l and receptor Cxcr3.2 as essential to control osteoclast progenitor recruitment and differentiation at bone resorption sites. Cxcr3.2 activity can be blocked by small-molecule inhibitors that protect bone from osteoporotic insult. Our study demonstrates the potential of fish for osteoporosis drug discovery and opens avenues for future osteoporosis therapy.