bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of sub- and super-solar metallicities on the composition of solid planetary building blocks
Authors: Bitsch Bertram , Battistini Chiara
Published: November 2019

The composition of the protoplanetary disc is thought to be linked to the composition of the host star, where a higher overall metallicity provides the building blocks for planets. However, most of the planet formation simulations only link the stellar iron abundance [Fe/H] to planet formation and the iron abundance in itself is used as a proxy to scale all elements. On the other hand, large surveys of stellar abundances show that this is not true. Here we use stellar abundances from the GALAH surveys to determine the average detailed abundances of Fe, Si, Mg, O, and C for a broad range of host star metallicities with [Fe/H] spanning from −0.4 to +0.4. Using an equilibrium chemical model that features the most important rock-forming compounds as well as volatile contributions of H2O, CO2, CH4, and CO, we calculate the chemical composition of solid planetary building blocks around stars with different metallicities. Solid building blocks that are formed entirely interior to the water ice line (T > 150 K) only show an increase in Mg2SiO4 and a decrease in MgSiO3 for increasing host star metallicity, which is related to the increase of [Mg/Si] for higher [Fe/H]. Solid planetary building blocks forming exterior to the water ice line (T < 150 K), on the other hand, show dramatic changes in their composition. In particular, the water ice content decreases from around ~50% at [Fe/H] = −0.4 to ~6% at [Fe/H] = 0.4 in our chemical model. This is mainly caused by the increasing C/O ratio with increasing [Fe/H], which binds most of the oxygen in gaseous CO and CO2, resulting in a small water ice fraction. Planet formation simulations coupled with the chemical model confirm these results by showing that the water ice content of super-Earths decreases with increasing host star metallicity due to the increased C/O ratio. This decrease of the water ice fraction has important consequences for planet formation, planetary composition, and the eventual habitability of planetary systems formed around these high-metallicity stars.
Time-resolved photometry of the young dipper RX J1604.3-2130A
Authors: Sicilia-Aguilar A. , Manara C. F. , de Boer J. , Benisty M. , Pinilla P. , Bouvier J.
Published: November 2019

Context. RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk, with respect to its face-on outer disk.

Aims. We aim to study the eclipses to constrain the inner disk properties.

Methods. We used time-resolved photometry from the Rapid Eye Mount telescope and Kepler 2 data to study the multi-wavelength variability, and archival optical and infrared data to track accretion, rotation, and changes in disk structure.

Results. The observations reveal details of the structure and matter transport through the inner disk. The eclipses show 5 d quasi-periodicity, with the phase drifting in time and some periods showing increased/decreased eclipse depth and frequency. Dips are consistent with extinction by slightly processed dust grains in an inclined, irregularly-shaped inner disk locked to the star through two relatively stable accretion structures. The grains are located near the dust sublimation radius (~0.06 au) at the corotation radius, and can explain the shadows observed in the outer disk. The total mass (gas and dust) required to produce the eclipses and shadows is a few % of a Ceres mass. Such an amount of mass is accreted/replenished by accretion in days to weeks, which explains the variability from period to period. Spitzer and WISE infrared variability reveal variations in the dust content in the innermost disk on a timescale of a few years, which is consistent with small imbalances (compared to the stellar accretion rate) in the matter transport from the outer to the inner disk. A decrease in the accretion rate is observed at the times of less eclipsing variability and low mid-IR fluxes, confirming this picture. The v sin i = 16 km s−1 confirms that the star cannot be aligned with the outer disk, but is likely close to equator-on and to be aligned with the inner disk. This anomalous orientation is a challenge for standard theories of protoplanetary disk formation.
Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry
Authors: Gu H. , Cui J. , Lavvas P. P. , Niu D.-D. , Wu X.-S. , Guo J.-H. , He F. , Wei Y.
Published: November 2019

Context. Atmospheric escape has an appreciable impact on the long-term climate evolution on terrestrial planets. Exothermic chemistry serves as an important mechanism driving atmospheric escape and the role of such a mechanism is of great interest for Titan due to its extremely complicated atmospheric and ionospheric composition.

Aims. This study is devoted to a detailed investigation of neutral N and C escape on the dayside of Titan, which is driven by exothermic neutral–neutral, ion–neutral, and dissociative recombination (DR) reactions. It was carried out based on the extensive measurements of Titan’s upper atmospheric structure by a number of instruments on board Cassini, along with an improved understanding of the chemical network involved.

Methods. A total number of 14 C- and N-containing species are investigated based on 146 exothermic chemical reactions that release hot neutrals with nascent energies above their respective local escape energies. For each species and each chemical channel, the hot neutral production rate profile is calculated, which provides an estimate of the corresponding escape rate when combined with the appropriate escape probability profile obtained from a test particle Monte Carlo model.

Results. Our calculations suggest a total N escape rate of 9.0 × 1023 s−1 and a total C escape rate of 4.2 × 1023 s−1, driven by exothermic chemistry and appropriate for the dayside of Titan. The former is primarily contributed by neutral-neutral reactions, whereas the latter is dominated by ion–neutral reactions; however, contributions from neutral–neutral and DR reactions to the latter cannot be ignored either. Our calculations further reveal that the bulk of N escape is driven by hot N(4S) production from the collisional quenching of N(2D) by ambient N2, while C escape is mainly driven by hot CH3 and CH4 production via a number of important ion–neutral and neutral–neutral reactions.

Conclusions. Considered in the context of prior investigations of other known escape mechanisms, we suggest that exothermic chemistry is likely to contribute appreciably to non-thermal C escape on the dayside of Titan, although it plays an insignificant role in N escape.
Orthopaedic research in low-income countries: A bibliometric analysis of the current literature
Authors: Graham Simon Matthew , Brennan Ciaran , Laubscher Maritz , Maqungo Sithombo , Lalloo David G. , Perry Daniel C. , Mkandawire Nyengo , Harrison William J.
Published: November 2019

Background: To perform a bibliometric analysis and quantify the amount of orthopaedic and trauma literature published from low-income countries (LICs).

Methods and methods: The Web of Science database was utilised to identify all indexed orthopaedic journals. All articles published in the 76 orthopaedics journals over the last 10 years were reviewed, to determine their geographic origin.

Results: A total of 131 454 articles were published across 76 orthopaedic journals over the last 10 years. Of these, 132 (0.1%) were published from LICs and 3515 (2.7%) were published from lower middle-income countries (LMICs); 85.7% (n = 112 716) of published orthopaedic research was undertaken in a high-income setting. The majority of the studies (n = 90, 74.4%) presented level IV evidence. Only 7.4% (n = 9) were high-quality evidence (level I or II). Additionally, the majority of research (74 articles, 56%) was published in partnership with high-income countries (HICs).

Conclusions: There is a stark mismatch between the publication of scientific reports on orthopaedic research and the geographical areas of greatest clinical need. We believe there is an urgent need for orthopaedic research to be carried out in low-income settings to guide treatment and improve outcomes, rather than assuming that evidence from high-income settings will translate into this environment.

Level of evidence: IV
Interagieren statt belehren – Motivational Interviewing in die Praxis integrieren
Authors: Messner Thomas
Published: November 2019

Noch immer ist die Bedeutung interaktiver Prozesse in der Physiotherapie relativ gering. Thomas Messner will das ändern. Er plädiert dafür, einen besseren Rahmen für professionelle Gespräche zu schaffen. Profitieren können Therapeuten und Patienten.
Terminators – Maier-Kolumne
Authors: Maier Ulrike
Published: November 2019

Mit der Terminvergabe in einer Physiopraxis ist das manchmal so eine Sache. Es gibt Patienten, die sich geduldig einen Termin geben lassen, und es gibt solche, die nicht einmal vor nächtlichen Behandlungen Halt machen, wenn es sie denn geben würde. Da bleibt einem als Therapeut oft nur, an seine innere Mitte und Gelassenheit zu appellieren – auch wenn das manchmal schwerfällt.
Vitamin D Status and Thyroid Autoantibodies in Autoimmune Thyroiditis
Authors: Koehler Viktoria F. , Filmann Natalie , Mann W. Alexander
Published: November 2019

A lack of vitamin D seems to be related to autoimmune diseases including autoimmune thyroiditis (AIT). This study intends to determine the correlation between improvement of 25-hydroxyvitamin D [25(OH)D] levels and AIT in patients from an outpatient endocrine clinic in Frankfurt, Germany. This study included 933 patients with thyroid peroxidase antibodies (anti-TPO-Ab) ≥34 kIU/l, including most patients with clear AIT due to a concurrent sonographic evidence of reduced echogenicity. We performed clinical evaluation and laboratory analysis at five points in time within two years retrospectively. Due to a high dropout rate within the observation period, we excluded the last two time points from analysis. Data from 933 AIT patients revealed 89% having vitamin D deficiency or insufficiency [25(OH)D <75 nmol/l] with a median 25(OH)D level of 39.7 nmol/l. At baseline, a weak inverse correlation between 25(OH)D and anti-TPO-Ab was observed during winter (rs=–0.09, p=0.048*), but not during summer time (p>0.2). We discovered 58 patients having initially a 25(OH)D level < 75 nmol/l (median: 40.2 nmol/l), which improved over time to a 25(OH)D level ≥ 75 nmol/l (median: 83.2 nmol/l, p<0.0005***). Simultaneously, the median anti-TPO-Ab level showed a significant decrease of 25% from 245.8 to 181.3 kIU/l (p=0.036*). A significant reduction of the median anti-TPO-Ab level of 9% was also observed in the control group, which consisted of patients having constantly a 25(OH)D level <75 nmol/l. The result may suggest that in particular patients with 25(OH)D levels < 75 nmol/l benefit from an increase of 25(OH)D levels ≥ 75 nmol/l. Further prospective randomized controlled clinical trials are needed to finally evaluate if vitamin D has immunmodulatory effects in AIT.
Endolichenic fungal diversity associated with some lichens of the Western Ghats
Authors: Rajulu Meenavalli Babu Govinda , Thirunavukkarasu Nagamani , Kumar Subramanya Shravan , Kaur Tanveer , Reddy Mondem Sudhakara , Suryanarayanan Trichur Subramanian
Published: November 2019

A total of 389 strains of fungi belonging to 38 species were isolated from 10 lichen species of the Western Ghats, southern India. All the lichens screened, irrespective of their growth forms or location, harboured endolichenic fungi. Most of the fungi belonged to the Ascomycotina. Chaetomium sp. 1, Hypoxylon investiens, Nemania bipapillata, Nodulisporium sp., Paecilomyces sp., and Sporormiella intermedia were the most common ones and were present in 5 or more lichen species. Of the 28 sporulating fungi, 7 belonged to Xylariales, and their total colonization frequency in all the lichens was also high. This observation further substantiates the high ecological amplitude of Xylariales, possibly due to overlapping ecological niches and their ability to inhibit co-occurring endolichenic fungi.
Site-Specific Synthesis of Carbazole Derivatives through Aryl Homocoupling and Amination
Authors: Ban Jaeyoung , Lim Minkyung , Shabbir Saira , Baek Junghyun , Rhee Hakjune
Published: November 2019

We synthesized various carbazoles from anilines through a three-step process with good overall yields (up to 48%). This process comprises N-acetylation, copper(0)-mediated Ullmann homocoupling, and acid-mediated intramolecular amination. It permits various functional­ groups on the substrate. Scale-up of the developed three-step synthetic route to carbazoles was also demonstrated.
Marginal Discrepancy of Single Implant-Supported Metal Copings Fabricated by Various CAD/CAM and Conventional Techniques Using Different Materials
Authors: Ghodsi Safoura , Alikhasi Marzieh , Soltani Nika
Published: November 2019

Objective Framework patterns can be formed using various materials such as wax, acrylic resin, or composite. Frameworks can be fabricated using either conventional or computerized techniques, using additive or subtractive method. This study aimed to compare the marginal adaptation of metal copings fabricated by two computerized technologies (milling and rapid prototyping) and additive conventional methods using different materials.

Materials and Methods Seventy-two fixture analogs were mounted vertically in acrylic resin. One-piece abutments with 5.5 mm in length and 6 degrees of convergence were secured into the analogs. The experimental frameworks were fabricated using either subtractive CAD/CAM milling (by wax, soft or hard metal), additive rapid prototyping (by wax), or conventional pattern fabrication (by wax [control] or acrylic resin). Wax and acrylic resin patterns were casted in Ni-Cr alloy. Marginal discrepancy was measured in 12 points by video measuring machine.

Statistical Analysis One-way ANOVA and posthoc tests were used to detect any significant difference among the groups at α= 0.05.

Results There was a statistically significant difference among the marginal discrepancy of six groups (p = 0.018). The Tukey test indicated a significant difference between CAD/milling of soft metal and conventional wax pattern groups (p = 0.011); a significant difference was also reported between CAD/milling of wax patterns and control group (p = 0.046).

Conclusions Frameworks fabricated by conventional wax-up showed the largest marginal gaps, while the marginal gap created by frameworks made of soft metal CAD/milling were the smallest. In addition, frameworks fabricated by rapid prototyping showed clinically acceptable adaptations.
Computed Tomography Evaluation of Brain in Chronic Alcoholics
Authors: Sandhu Gurpreet S. , Nagrale Hiresh R.
Published: November 2019

Background Chronic alcoholism causes brain damage. Published data from rural India is scant. Our aim is to determine computed tomography (CT) changes in the brain of rural chronic alcoholics.

Methods This prospective cross-sectional study was done in our tertiary care hospital on chronic alcoholic patients referred from deaddiction center over a period of 2 years. Age- and sex-matched nonalcoholic controls were included and Student’s t-test and chi-square test comparison was done. Correlation coefficient was obtained by Pearson’s correlation coefficient. Patients and the controls were studied in two age groups: 30 to 45 and 46 to 60 years. Noncontrast CT scan of head was done in each case and CT indices of brain damage were measured.

Results The study included 106 alcoholics out of which 55 were in the younger age group (30–45 years) and 51 in the older age group (46–60 years). Seven hundred age-matched, nonalcoholic controls were included. Mean values of ethanol were higher in the older age group than in the younger age group. As compared with controls, various CT scan indices of ventricular changes, cortical changes, and subcortical changes were significantly higher in both age groups. In both age groups, there was a significant decrease in the mean values of hemoglobin and a significant increase in the mean values of indices of brain damage with increase in the grade of alcoholism.

Conclusion The results of this prospective epidemiological study showed marked alterations in all CT indices of brain atrophy and were correlated to the duration and amount of ethanol consumption. This study highlights that chronic alcoholism is a significant risk factor for brain atrophy.
Correction to: Comparing engagement by migrants in domestic and in country-of-origin political activities across European cities
Authors: Pilati Katia , Herman Barbara
Published: November 2019

The article Comparing engagement by migrants in domestic and in country-of-origin political activities across European cities, written by Katia Pilati and Barbara Herman, was originally published electronically on the publisher’s internet portal on 16 July 2018 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 21 November 2019 to © The Author(s) 2018 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected.
Unveiling pathways for the fissure among secessionists and unionists in Catalonia: identities, family language, and media influence
Authors: Oller José M. , Satorra Albert , Tobeña Adolf
Published: November 2019

Catalonian secessionism acquired prominence from 2010 onwards. During the last decade secessionist parties won three regional elections and sustained Governments by tiny majorities at the Autonomous Parliament. Two illegal consultations about self-determination were called and around 2 million (38% of population census) supported secession from Spain. An “Independence Declaration” was proclaimed on 27th Oct. 2017, followed by suspension of Home Rule sanctioned by Spanish Parliament that endured till mid-2018. The main consequence of the secessionist push was the build-up of a confrontation between two large segments of Catalan citizenry, unionists and secessionists, which was absent before. This study aims to shed light on the rise of secessionism and the appearance of a deep fissure between these communities. By building upon the complete series of data from iterated official polls (88.538 respondents, 45 surveys), the paper displays the evolving changes along the period 2006–2019 of national identity feelings (“sense of belonging”). Along that period, there were increases exceeding 15 percentage points of “only Catalan” national identity and analogous decreases of "equally Catalan and Spanish" dual national identity. The findings disclosed highly significant covariations between changing trends on national identity feelings with: (1) family/mother language, Catalan vs. Spanish; (2) following regional media versus other media. Since language/ascendancy origins and media consumption trends are closely interrelated, within Catalonia, our discussion focuses on the role played by such ethno-cultural cleavage. Further, statistical analysis for longitudinal data identified several turning points linked to singular political events that likely accentuated polarization around the issue of secession. The findings unveil evolving tracks that could help in the understanding of a process that, in a very short time, produced a severe social division within a fully open and democratic society at the heart of Europe.
Correction: Metrics for the sustainable development goals: renewable energy and transportation
Authors: Buonocore Jonathan J. , Choma Ernani , Villavicencio Aleyda H. , Spengler John D. , Koehler Dinah A. , Evans John S. , Lelieveld Jos , Klop Piet , Sanchez-Pina Ramon
Published: November 2019

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
A U-shaped microwave resonator for flexible mechanical sensors application
Authors: Tang Jun , Zhu Qiang , Li Changlong , Chen Yulei , Zhang Zhenrong , Guo Hao , Nian Fushun , Liu Wenyao , Cai Anjiang , Yang Baoguo , Liu Jun
Published: November 2019

A flexible mechanical deformation test system, which is a combination of the microwave and the flexible film, is proposed. The system consists of a U-shaped microwave resonator, coaxial transmission line, and PDMS flexible substrate. Microwave signals are generated from the vector network analyzer and loaded to the coaxial transmission line and then coupled to the U-shaped resonator through the coupling loop. The resonator works at the gigahertz band with the test range from 3 GHz to 40 GHz. The resonant frequency of the resonator can be adjusted by changing the shape of PDMS, and the related signals can be detected by using the S11 parameter of the microwave. The response time of the U-shaped resonator is less than 20 ms, and the sensitivity on the curved surface is 12.5 Hz/nm.
Solving fluid flow problems using semi-supervised symbolic regression on sparse data
Authors: El Hasadi Yousef M. F. , Padding Johan T.
Published: November 2019

The twenty first century is the century of data. Machine learning data and driven methods start to lead the way in many fields. In this contribution, we will show how symbolic regression machine learning methods, based on genetic programming, can be used to solve fluid flow problems. In particular, we will focus on the fluid drag experienced by ellipsoidal and spherocylinder particles of arbitrary aspect ratio. The machine learning algorithm is trained semisupervised by using a very limited amount of data for a specific single aspect ratio of 2.5 for ellipsoidal and 4 for spherocylindrical particles. The effect of the aspect ratio is informed to the algorithm through what we call previous knowledge, for example, known analytical solutions in certain limits, or through interbreeding of different flow solutions from the literature. Our results show good agreement with literature results, while they are obtained computationally faster and with less computing resources. Also, the machine learning algorithm discovered that for the case of prolate spheroids, the difference between the drag coefficients perpendicular and parallel to the flow in the high Reynolds number regime only depend on the aspect ratio of the geometry, even when the individual drag coefficients still decrease with increasing Re.
Mechanical properties of hydrogenated amorphous silicon (a-Si:H) particles
Authors: Jiang Taizhi , Khabaz Fardin , Marne Aniket , Wu Chenglin , Gearba Raluca , Bodepudi Revanth , Bonnecaze Roger T. , Liechti Kenneth M. , Korgel Brian A.
Published: November 2019

A nanoindenter was used to compress individual particles of hydrogenated amorphous silicon (a-Si:H) ranging in diameter from 290 nm to 780 nm. The colloidal synthesis used to produce the particles enables the hydrogen content to be manipulated over a wide range, from about 5 at. % to 50 at. %, making these a-Si:H particles promising for applications in lithium ion batteries, hydrogen storage, and optical metamaterials. Force-displacement curves generated using a tungsten probe flattened with focused ion beam exhibited elastic and then plastic deformations, followed by fracture and crushing of the particles. For particles with 5% and 50% H, Young's moduli, yield strengths, and compressive strengths were 73.5(±19.5) GPa, 5.8 GPa, and 3.2(±0.1)–9.3(±0.6) GPa and 31.2(±9.0) GPa, 2.5 GPa, and 1.8 (±0.3)–5.3(±0.8) GPa, respectively. Particles with more hydrogen were significantly more compliant and weaker. This is consistent with atomistically detailed molecular dynamics simulations, which revealed compression forms of an interphase of H atom clusters that weakens the material.
Adiabatic connection in density functional theory in two-dimensions: A semi-analytic wavefunction based study for two-electron atomic systems
Authors: Singh Rabeet , Patra Bikash , Patra Abhilash , Harbola Manoj K. , Samal Prasanjit
Published: November 2019

This work focuses on studying the adiabatic-connection in density functional theory in two dimensions. It employs a recently developed accurate form of wavefunction for two-electron systems. The explicit semianalytic form of the wavefunction makes it possible to calculate ground state wavefunctions, energies, densities, and the resulting properties for the scaled Coulomb interaction between the electrons at fixed density accurately. The results so obtained for the correlation energies are then used as the reference values for studying the performance of two-dimensional correlation energy functionals.
Numerical and experimental investigation of dough kneading in a three-dimensional spiral kneader
Authors: Abu-Farah Laila , Goudoulas Thomas B. , Hooshyar Soroush , Germann Natalie
Published: November 2019

This work reports on the first three-dimensional viscoelastic dough kneading simulation performed in a spiral kneader. Unstructured tetrahedral grids were generated using ICEM CFD 17.1. Viscoelastic volume-of-fluid simulations were performed using OpenFOAM v.4.0 in combination with the RheoTool package v.2.0. The White-Metzner model with a Bird-Carreau type of shear-rate dependency of the viscosity and relaxation time was utilized to describe the rheology of the dough matrix. We validated our numerical method by simulating the viscoelastic rod climbing benchmark problem in a cylindrical bowl. The temporal evolution of the dough surface was compared with screenshots obtained with a high-speed video camera during laboratory kneading. We found that the curvature of the free surface matches the experimental data well. With our numerical approach, we were able to predict the formation, extension, and breakup of dough pockets. The dough is convected around the inner stationary rod by the rotation of the outer cylindrical bowl, whereas the spiral arm located in between these two parts produces spiral flow patterns. Vertical mixing is not as good as radial mixing and may be enhanced by utilizing two spiral arms similar to hand kneading. Industrial kneading geometries and processes may be further optimized by performing such types of simulations.
Enhancing the efficiency of PTB7-Th:COi8DFIC-based ternary solar cells with versatile third components
Authors: Li Wei , Xiao Zuo , Smith Joel A. , Cai Jinlong , Li Donghui , Kilbride Rachel C. , Spooner Emma L. K. , Game Onkar S. , Meng Xianyi , Liu Dan , Jones Richard A. L. , Lidzey David G. , Ding Liming , Wang Tao
Published: November 2019

Traditional single-junction binary organic solar cells suffer from narrow absorption windows, limiting their ability to harvest photons. One promising approach to avoid this issue is through the construction of a ternary system to enhance the spectral response and efficiency. However, the complex morphology and photophysical processes within ternary blends leave the criteria of an effective third component unclear, and so they remain a challenge. In this work, we report on the fabrication of PTB7-Th:COi8DFIC-based ternary solar cells with enhanced efficiency by employing either a polymer donor or a nonfullerene acceptor as the third component. We demonstrate that the third component is highly associated with the condensed state of the host acceptor and is the primary factor in determining efficiency improvement. The π-π stacking molecular packing of COi8DFIC helps to maintain the optimal phase separation within the ternary blends and improves both the hole and electron charge mobilities, resulting in enhanced power conversion efficiency of over 14%, compared to 13.1% in binary devices. We also found an excessive amount of polymer donor or nonfullerene acceptor increases the phase separation and encourages lamellar crystallization with the host acceptor domain, resulting in reduced light-harvesting and external quantum efficiencies at long wavelengths. Our results provide a rational guide to selecting the third component to fabricate high-performance nonfullerene-based ternary solar cells.
Electron spin polarization in an Al(III) porphyrin complex with an axially bound nitroxide radical
Authors: Poddutoori Prashanth K. , Kandrashkin Yuri E. , Karr Paul , van der Est Art
Published: November 2019

The generation and transfer of electron spin polarization and coherence plays an important role in quantum information technologies and spintronics. In this context, the excited state spin dynamics of molecular systems in which a stable free radical is attached to a chromophore are of particular interest. In such complexes, the coupling between the electron spin on the free radical with those on the chromophore generates excited states referred to as sing-doublet, trip-doublet, and trip-quartet. Here, we study the light-induced electron spin polarization in an aluminum(iii) porphyrin (AlPor) complex in which the nitroxide (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) is covalently bound to the Al center via an ester linkage. In addition to the covalent bond to the TEMPO moiety, the Al center in AlPor also acts as a Lewis acid and can coordinate Lewis bases such as pyridine. Without pyridine bound, the spin polarized transient electron paramagnetic resonance spectrum of the complex at 80 K is unusual and displays a strong absorptive pattern with a Lorentzian lineshape. Coordination of pyridine to AlPor-TEMPO results in a dramatic change in the spin polarization pattern and a spectrum typical of the quartet state with broad wings from the ms = ±1/2 ↔ ±3/2 transitions with emissive/absorptive polarization and a narrow absorptive peak from the ms = ±1/2 ↔ ±1/2 transitions. At later times, the pattern evolves to a purely absorptive spectrum similar to that observed without pyridine. These changes are discussed in terms of a model in which back and forth transitions between the nearly degenerate lowest trip-doublet and trip-quartet states occur. It is argued that these transitions lead to the observed net polarization in AlPor-TEMPO and are fast enough that the outer lines are broadened. Density functional theory computations and the UV/Vis spectra suggest that the exchange interaction between TEMPO and the triplet state of AlPor increases when pyridine is bound, and the near degeneracy of the lowest excited states is lifted. It is argued that this slows the back and forth transitions which results in the strong change in the polarization pattern.
X-ray diffraction and Raman characterization of β-Ga2O3 single crystal grown by edge-defined film-fed growth method
Authors: Yao Yongzhao , Ishikawa Yukari , Sugawara Yoshihiro
Published: November 2019

The crystallinity and wafer uniformity of (2¯01) and (010) oriented β-Ga2O3 substrates grown by edge-defined film-fed growth (EFG) were investigated by laboratory X-ray diffraction (XRD), synchrotron XRD, polarized Raman spectroscopy, and Raman mapping. XRD results indicated that the EFG substrates had superior crystallinity and high uniformity. Position-dependent XRD ω-rocking curves recorded across a 50.8-mm-diameter substrate had small standard deviations of δF = 1.6% for the full width at half maximum and δP = 2.8% for the peak intensity. The radius of curvature was measured to be 37.7 m for the (2¯01) substrate and 16.4 m for the (010) substrate. The results of synchrotron XRD with various beam sizes suggested that the curving of crystal planes was mainly along the [010] growth direction rather than along the [102] direction. Raman spectra showed that Sn doping up to 3.3 × 1018 cm−3 did not give rise to a notable Raman peak shift. The strain distribution evaluated by Raman mapping implied the high uniformity of both (2¯01) and (010) substrates. From these results, it was concluded that β-Ga2O3 ingots grown by EFG have high crystallinity and can be treated as three-dimensionally uniform bulk crystals in the cases of both undoped and Sn-doped growth.
Photoelectron spectroscopy of para-benzoquinone cluster anions
Authors: Mensa-Bonsu Golda , Wilson Mark R. , Tozer David J. , Verlet Jan R. R.
Published: November 2019

The photoelectron spectra of para-benzoquinone radical cluster anions, (pBQ)n− (n = 2–4), taken at hv = 4.00 eV are presented and compared with the photoelectron spectrum of the monomer (n = 1). For all clusters, a direct detachment peak can be identified, and the incremental increase in the vertical detachment energy of ∼0.4 eV n−1 predominantly reflects the increase in cohesion energy as the cluster size increases. For all clusters, excitation also leads to low energy electrons that are produced by thermionic emission from ground electronic state anionic species, indicating that resonances are excited at this photon energy. For n = 3 and 4, photoelectron features at lower binding energy are observed which can be assigned to photodetachment from pBQ− for n = 3 and both pBQ− and (pBQ)2− for n = 4. These observations indicate that the cluster dissociates on the time scale of the laser pulse (∼5 ns). The present results are discussed in the context of related quinone cluster anions.
Flying in groups saves energy and enhances wing performance
Authors: Mandel Savannah
Published: November 2019

The mechanical benefits of birds schooling together encourages unique, energy-efficient, aeronautical designs.
The IκB-protein BCL-3 controls Toll-like receptor-induced MAPK activity by promoting TPL-2 degradation in the nucleus
Authors: Collins Patricia E. , Somma Domenico , Kerrigan David , Herrington Felicity , Keeshan Karen , Nibbs Robert J. B. , Carmody Ruaidhrí J.
Published: November 2019

Significance

The NF-ĸB and mitogen-activated protein kinase (MAPK) pathways coordinate the cellular response to most immune stimuli. Toll-like (TLR) and TNF receptor activation of the MAPK pathway requires activation of the TPL-2 kinase. Active TPL-2 is an unstable, short-lived protein, which limits MAPK activity and controls inflammatory responses. Here we report the surprising discovery that active TPL-2 shuttles between the cytoplasm and the nucleus, where it is degraded by the proteasome. BCL-3, a nuclear regulator of NF-ĸB, promotes the nuclear localization and degradation of TPL-2 in order to limit MAPK activity and determines the amount of TLR ligand required to initiate an inflammatory response. Thus, the nucleus is a key site for the integrated regulation of NF-ĸB– and MAPK-driven inflammatory responses.
The association between serotonin transporter availability and the neural correlates of fear bradycardia
Authors: Schipper Pieter , Hiemstra Marlies , Bosch Kari , Nieuwenhuis Desiree , Adinolfi Annalisa , Glotzbach Sabine , Borghans Bart , Lopresto Dora , Fernández Guillén , Klumpers Floris , Hermans Erno J. , Roelofs Karin , Henckens Marloes J. A. G. , Homberg Judith R.
Published: November 2019

Susceptibility to stress-related psychopathology is associated with reduced expression of the serotonin transporter (5-HTT), particularly in combination with stress exposure. Aberrant physiological and neuronal responses to threat may underlie this increased vulnerability. Here, implementing a cross-species approach, we investigated the association between 5-HTT expression and the neural correlates of fear bradycardia, a defensive response linked to vigilance and action preparation. We tested this during threat anticipation induced by a well-established fear conditioning paradigm applied in both humans and rodents. In humans, we studied the effect of the common 5-HTT-linked polymorphic region (5-HTTLPR) on bradycardia and neural responses to anticipatory threat during functional magnetic resonance imaging scanning in healthy volunteers (n= 104). Compared with homozygous long-allele carriers, the 5-HTTLPR short-allele carriers displayed an exaggerated bradycardic response to threat, overall reduced activation of the medial prefrontal cortex (mPFC), and increased threat-induced connectivity between the amygdala and periaqueductal gray (PAG), which statistically mediated the effect of the 5-HTTLPR genotype on bradycardia. In parallel, 5-HTT knockout (KO) rats also showed exaggerated threat-related bradycardia and behavioral freezing. Immunohistochemistry indicated overall reduced activity of glutamatergic neurons in the mPFC of KO rats and increased activity of central amygdala somatostatin-positive neurons, putatively projecting to the PAG, which—similarly to the human population—mediated the 5-HTT genotype’s effect on freezing. Moreover, the ventrolateral PAG of KO rats displayed elevated overall activity and increased relative activation of CaMKII-expressing projection neurons. Our results provide a mechanistic explanation for previously reported associations between 5-HTT gene variance and a stress-sensitive phenotype.
A universal transportin protein drives stochastic choice of olfactory neurons via specific nuclear import of a
sox-2
-activating factor
Authors: Alqadah Amel , Hsieh Yi-Wen , Xiong Rui , Lesch Bluma J. , Chang Chieh , Chuang Chiou-Fen
Published: November 2019

Significance

Stochastic cell fate decisions are conserved and prominent processes during development, but the underlying molecular mechanisms are only partly understood. In the nematode
Caenorhabditis elegans
, the AWC sensory neuron pair asymmetrically differentiates into 2 distinct identities in a stochastic manner. Through identification of a unique transportin allele, we elucidate a mechanism by which a homeodomain-like factor couples voltage- and calcium-activated potassium channels to transactivation of a HMG-box transcription factor expression for the stochastic choice of AWC identities. We show that transportin drives nuclear import of the homeodomain-like factor to activate the expression of the HMG-box transcription factor for stochastic AWC identities. Our findings also provide structure-function insight into a conserved amino acid residue of transportins in cell type diversification.
The extracellular DNA lattice of bacterial biofilms is structurally related to Holliday junction recombination intermediates
Authors: Devaraj Aishwarya , Buzzo John R. , Mashburn-Warren Lauren , Gloag Erin S. , Novotny Laura A. , Stoodley Paul , Bakaletz Lauren O. , Goodman Steven D.
Published: November 2019

Significance

Most chronic and recurrent bacterial infections are the result of biofilms. Extracellular DNA (eDNA) is a ubiquitous and pivotal structural component of biofilms that protects the resident bacteria from the host immune system and antimicrobial agents. It is of the highest priority to characterize the structure of the eDNA to understand the development of bacterial biofilm communities. Here, we employed the prototypic Holliday junction-specific (HJ) DNA-binding protein RuvA and demonstrated that eDNA within biofilms formed by 3 human pathogens, uropathogenicEscherichia coli, nontypeableHaemophilus influenzae, andStaphylococcus epidermidiswas structurally related to HJ recombination intermediates. We further demonstrated that this HJ-like structure was critical to the structural and mechanical integrity of the bacterial biofilm matrix.
Status anxiety mediates the positive relationship between income inequality and sexualization
Authors: Blake Khandis R. , Brooks Robert C.
Published: November 2019

Income inequality generates and amplifies incentives, particularly incentives for individuals to elevate or maintain their status, with important consequences for the individuals involved and aggregate outcomes for their societies [R. G. Wilkinson, K. E. Pickett,
Annu. Rev. Sociol.
35, 493–511 (2009)]. Economically unequal environments intensify men’s competition for status, respect, and, ultimately, mating opportunities, thus elevating aggregate rates of violent crime and homicide [M. Daly, M. Wilson, Evolutionary Psychology and Motivation (2001)]. Recent evidence shows that women are more likely to post “sexy selfies” on social media and that they spend more on beautification in places where inequality is high rather than low [K. R. Blake, B. Bastian, T. F. Denson,
et al.
,
Proc. Natl. Acad. Sci. U.S.A.
115, 8722–8727 (2018)]. Here we test experimentally for causal links between income inequality and individual self-sexualization and status-related competition. We show that manipulating income inequality in a role-playing task indirectly increases women’s intentions to wear revealing clothing and that it does so by increasing women’s anxiety about their place in the social hierarchy. The effects are not better accounted for by wealth/poverty than by inequality or by modeling anxiety about same-sex competitors in place of status anxiety. The results indicate that women’s appearance enhancement is partly driven by status-related goals.
HISTONE DEACETYLASE 9 stimulates auxin-dependent thermomorphogenesis in
Arabidopsis thaliana
by mediating H2A.Z depletion
Authors: van der Woude Lennard C. , Perrella Giorgio , Snoek Basten L. , van Hoogdalem Mark , Novák Ondřej , van Verk Marcel C. , van Kooten Heleen N. , Zorn Lennert E. , Tonckens Rolf , Dongus Joram A. , Praat Myrthe , Stouten Evelien A. , Proveniers Marcel C. G. , Vellutini Elisa , Patitaki Eirini , Shapulatov Umidjon , Kohlen Wouter , Balasubramanian Sureshkumar , Ljung Karin , van der Krol Alexander R. , Smeekens Sjef , Kaiserli Eirini , van Zanten Martijn
Published: November 2019

Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the
YUCCA8
locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with
YUCCA8
, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis.
Extreme bradycardia and tachycardia in the world’s largest animal
Authors: Goldbogen J. A. , Cade D. E. , Calambokidis J. , Czapanskiy M. F. , Fahlbusch J. , Friedlaender A. S. , Gough W. T. , Kahane-Rapport S. R. , Savoca M. S. , Ponganis K. V. , Ponganis P. J.
Published: November 2019

The biology of the blue whale has long fascinated physiologists because of the animal’s extreme size. Despite high energetic demands from a large body, low mass-specific metabolic rates are likely powered by low heart rates. Diving bradycardia should slow blood oxygen depletion and enhance dive time available for foraging at depth. However, blue whales exhibit a high-cost feeding mechanism, lunge feeding, whereby large volumes of prey-laden water are intermittently engulfed and filtered during dives. This paradox of such a large, slowly beating heart and the high cost of lunge feeding represents a unique test of our understanding of cardiac function, hemodynamics, and physiological limits to body size. Here, we used an electrocardiogram (ECG)-depth recorder tag to measure blue whale heart rates during foraging dives as deep as 184 m and as long as 16.5 min. Heart rates during dives were typically 4 to 8 beats min
−1
(bpm) and as low as 2 bpm, while after-dive surface heart rates were 25 to 37 bpm, near the estimated maximum heart rate possible. Despite extreme bradycardia, we recorded a 2.5-fold increase above diving heart rate minima during the powered ascent phase of feeding lunges followed by a gradual decrease of heart rate during the prolonged glide as engulfed water is filtered. These heart rate dynamics explain the unique hemodynamic design in rorqual whales consisting of a large-diameter, highly compliant, elastic aortic arch that allows the aorta to accommodate blood ejected by the heart and maintain blood flow during the long and variable pauses between heartbeats.
Crystal structure of the M
5
muscarinic acetylcholine receptor
Authors: Vuckovic Ziva , Gentry Patrick R. , Berizzi Alice E. , Hirata Kunio , Varghese Swapna , Thompson Geoff , van der Westhuizen Emma T. , Burger Wessel A. C. , Rahmani Raphaël , Valant Celine , Langmead Christopher J. , Lindsley Craig W. , Baell Jonathan B. , Tobin Andrew B. , Sexton Patrick M. , Christopoulos Arthur , Thal David M.
Published: November 2019

The human M
5
muscarinic acetylcholine receptor (mAChR) has recently emerged as an exciting therapeutic target for treating a range of disorders, including drug addiction. However, a lack of structural information for this receptor subtype has limited further drug development and validation. Here we report a high-resolution crystal structure of the human M
5
mAChR bound to the clinically used inverse agonist, tiotropium. This structure allowed for a comparison across all 5 mAChR family members that revealed important differences in both orthosteric and allosteric sites that could inform the rational design of selective ligands. These structural studies, together with chimeric swaps between the extracellular regions of the M
2
and M
5
mAChRs, provided structural insight into kinetic selectivity, where ligands show differential residency times between related family members. Collectively, our study provides important insights into the nature of orthosteric and allosteric ligand interaction across the mAChR family that could be exploited for the design of selective drugs.
Mechanisms for bacterial gliding motility on soft substrates
Authors: Tchoufag Joël , Ghosh Pushpita , Pogue Connor B. , Nan Beiyan , Mandadapu Kranthi K.
Published: November 2019

The motility mechanism of certain prokaryotes has long been a mystery, since their motion, known as gliding, involves no external appendages. The physical principles behind gliding still remain poorly understood. Using myxobacteria as an example of such organisms, we identify here the physical principles behind gliding motility and develop a theoretical model that predicts a 2-regime behavior of the gliding speed as a function of the substrate stiffness. Our theory describes the elasto-capillary–hydrodynamic interactions between the membrane of the bacteria, the slime it secretes, and the soft substrate underneath. Defining gliding as the horizontal translation under zero net force, we find the 2-regime behavior is due to 2 distinct mechanisms of motility thrust. On mildly soft substrates, the thrust arises from bacterial shape deformations creating a flow of slime that exerts a pressure along the bacterial length. This pressure in conjunction with the bacterial shape provides the necessary thrust for propulsion. On very soft substrates, however, we show that capillary effects must be considered that lead to the formation of a ridge at the slime–substrate–air interface, thereby creating a thrust in the form of a localized pressure gradient at the bacterial leading edge. To test our theory, we perform experiments with isolated cells on agar substrates of varying stiffness and find the measured gliding speeds in good agreement with the predictions from our elasto-capillary–hydrodynamic model. The mechanisms reported here serve as an important step toward an accurate theory of friction and substrate-mediated interactions between bacteria proliferating in soft media.
Measurement of the fractional orbital angular momentum of asymmetric laser beams by using two cylindrical lenses
Authors: Kotlyar V V , Kovalev A A , Porfirev A P
Published: November 2019

Here we propose and study both theoretically and experimentally a simple and high-efficient technique for measuring the orbital angular momentum (OAM) of paraxial laser beams. The technique uses two intensity distributions measured in the foci of two perpendicular cylindrical lenses. For these distributions, first-order intensity moments are calculated, which allow the OAM to be easily obtained. The experimental error increases from ~1% for small fractional OAM (up to 4) to ~8% for large fractional OAM (up to 30). We also show numerically that the proposed technique allows to determine the OAM if the beam is distorted by a phase diffuser in the initial plane.