bluuebunny/crossref_metadata_2025 huggingface dataset:
Alleviation of lead toxicity and phytostimulation in perennial ryegrass by the Pb-resistant fungus Trichoderma asperellum SD-5
Authors: Sun Xin , Sun Mingjie , Chao Ying , Wang Hui , Pan Hong , Yang Quangang , Cui Xiumin , Lou Yanhong , Zhuge Yuping
Published: December 2020

Lead (Pb), a highly toxic metal ion, is detrimental to plants and humans. Existing botanical techniques for Pb-contaminated soil remediation are limited in their efficiency. Here, we investigated the use of the fungus Trichoderma asperellum Samuels, Lieckf & Nirenberg SD-5, which we identified previously as being Pb-resistant, for phytoremediation and for its effects on plant growth, Pb adsorption, and physiological responses in perennial ryegrass (Lolium perenne L. ‘Lark’). We set up four soil treatments: CK (uncontaminated by Pb), T1 (1000 mg kg–1 Pb), T2 (1:9 ratio of sawdust to T1), and T3 (T2 inoculated with T. asperellum SD-5). A pot experiment revealed that the addition of the Pb-resistant microorganism promoted growth and increased biomass in ryegrass under Pb stress, in addition to significantly enhancing photosynthesis by increasing the leaf chlorophyll content and improving the total protein content and expression of the pAPX, POD, SOD, and GPX genes, evidence of an improved antioxidant system and the alleviation of Pb stress. We demonstrated that Pb-resistant microorganisms can enhance Pb extraction from the soil, thus improving remediation. Mitigation mechanisms operating at the physiological and gene expression levels were also determined, providing a scientific basis for the role of combined plant–microorganism methods in remediating Pb-contaminated soil.
An angular motion of a conserved four-helix bundle facilitates alternating access transport in the TtNapA and EcNhaA transporters
Authors: Masrati Gal , Mondal Ramakanta , Rimon Abraham , Kessel Amit , Padan Etana , Lindahl Erik , Ben-Tal Nir
Published: December 2020

Significance

Membrane-embedded cation/proton antiporters (CPAs) exchange monovalent cations with protons by alternating between two extreme states: inward- and outward-facing. Although atomic-resolution structures are available, there is still an ongoing debate regarding these antiporters’ transport mechanism. Here, we use computer simulations to explore the dynamics of two bacterial antiporters along two axes of motion: a tilting movement and a vertical translation of the antiporters’ two functional domains. By analyzing these dynamic changes, rather than comparing the two extreme states that CPAs adopt, we determine that it is the tilting movement of the antiporters’ mobile domain that drives the relevant conformational changes. Finally, by applying the knowledge gained from these simulations, we predict an unknown outward-facing conformation and verify it experimentally.
The origin, supply chain, and deforestation risk of Brazil’s beef exports
Authors: zu Ermgassen Erasmus K. H. J. , Godar Javier , Lathuillière Michael J. , Löfgren Pernilla , Gardner Toby , Vasconcelos André , Meyfroidt Patrick
Published: December 2020

Significance

The trade in agricultural commodities is a mainstay of the globalized economy, though the complex nature of commodity supply chains makes it difficult to identify the origin of and impact embedded in products. We brought together detailed data on trade, agriculture, and logistics to produce a subnational map of the origin of Brazil’s exports of beef, offal, and live cattle. Brazil is the world’s largest beef exporter, exporting one-fifth of its total production, and the sector is a major driver of deforestation. We traced cattle from 2,800 municipalities through to 152 importing countries, via thousands of companies handling their export and import. Our work gives an unprecedented insight into the origin of food and impacts embedded in global supply chains.
Oxygen limitation may affect the temperature and size dependence of metabolism in aquatic ectotherms
Authors: Rubalcaba Juan G. , Verberk Wilco C. E. P. , Hendriks A. Jan , Saris Bart , Woods H. Arthur
Published: December 2020

Significance

Organismal responses to climate change are mediated through its effects on physiology and metabolism. In aquatic environments, both water temperature and oxygen availability may modulate these responses by altering the aerobic metabolism fueling physiological performance. However, ecological models aimed at predicting how environmental factors shape aerobic metabolism disregard the role of oxygen supply. Here, we expand on these models by explicitly incorporating oxygen supply. Our results show that warmer water increases oxygen demand relative to supply, and the resulting reduction in aerobic scope appears to be stronger in larger individuals. Smaller aerobic scopes in warming water imply that climate change will reduce energy budgets needed to support the activities of aquatic animals and their physiological performance in the future.
Vibration enhanced cell growth induced by surface acoustic waves as in vitro wound-healing model
Authors: Brugger Manuel S. , Baumgartner Kathrin , Mauritz Sophie C. F. , Gerlach Stefan C. , Röder Florian , Schlosser Christine , Fluhrer Regina , Wixforth Achim , Westerhausen Christoph
Published: December 2020

Significance

Ultrasonic pressure fields have been proven to be beneficial for cell growth in vitro and in patients. However, conventional therapeutic-ultrasound treatment is subjected to limitations such as time restriction, external application, or energy loss. The application of surface acoustic waves (SAWs) can help to overcome some drawbacks. To understand the underlying mechanism, the adjusting parameters of SAWs and the intracellular response to the stimulation are evaluated. We identified a dependence of cell growth on SAW intensity and the presence of a vertical substrate deflection. While the cellular stress (reactive oxygen species) remains in the normal range, both cell migration and proliferation are increased. Due to the experimental design, the effect of enhanced cell growth is dominated by increased cell migration.
Driving integrative structural modeling with serial capture affinity purification
Authors: Liu Xingyu , Zhang Ying , Wen Zhihui , Hao Yan , Banks Charles A. S. , Lange Jeffrey J. , Slaughter Brian D. , Unruh Jay R. , Florens Laurence , Abmayr Susan M. , Workman Jerry L. , Washburn Michael P.
Published: December 2020

Significance

Determining the three-dimensional structures of protein complexes is critically important to guide biological research. Structural models of complexes can be built using powerful integrative approaches that combine emerging technologies in mass spectrometry, molecular modeling, and protein docking; however, preparing enriched biochemical samples suitable for analysis remains a major challenge. Here we describe serial capture affinity purification (SCAP), which can be used for the study of protein interactions in live cells and, when combined with cross-linking mass spectrometry, contribute distance restraints for integrative structural modeling. This broadly applicable technology can be used to study any protein complex in human tissue culture cells. We demonstrate SCAP capabilities on a poorly characterized epigenetic protein complex with roles in human cancer.
Atomic-scale evidence for highly selective electrocatalytic N−N coupling on metallic MoS
2
Authors: He Daoping , Ooka Hideshi , Kim Yujeong , Li Yamei , Jin Fangming , Kim Sun Hee , Nakamura Ryuhei
Published: December 2020

Significance

Molybdenum sulfide (MoS
2
) is the most studied two-dimensional (2D) material bar graphene. Current research on crystal-phase engineering focuses almost exclusively on the improvement of catalytic activity. However, the potential advantages of phase engineering toward regulation of selectivity control during multistep catalytic processes remain unexplored. Here, we report atomic-scale evidence on how metallic MoS
2
shows significantly higher selectivity compared to the semiconducting phase during multielectron reduction of nitrite to nitrous oxide. Namely, a reaction intermediate specific to metallic MoS
2
increases the selectivity by decoupling the proton and electron transfer steps. This has previously been shown to be a universal mechanism to enhance selectivity, and therefore, our work opens directions of the application of 2D materials toward selective electrocatalysis.
Actin flow-dependent and -independent force transmission through integrins
Authors: Driscoll Tristan P. , Ahn Sang Joon , Huang Billy , Kumar Abhishek , Schwartz Martin A.
Published: December 2020

Significance

The current paradigm for force transmission between cells and the extracellular matrix is the focal adhesion clutch, in which highly dynamic bonds involving the cytoskeletal linker proteins talin and vinculin transmit tension between moving actin filaments and immobile integrins. We found, however, that while dynamic bonds dominate at cell edges where actin flow is rapid, force transfer in adhesions further from the edge that may be linked to actin bundles is transmitted mainly through more stable interactions. Vinculin contributes to stable and not dynamic bonds as previously thought. We identify the protein interactions that mediate these mechanisms and demonstrate modulation by matrix stiffness. These data therefore substantially revise our view of force transmission in cell-matrix adhesions.
Pattern-induced local symmetry breaking in active-matter systems
Authors: Denk Jonas , Frey Erwin
Published: December 2020

Significance

Propelled agents that align their orientations upon collisions can give rise to macroscopic order. Depending on the details of the agents’ collisions, this ordering process can lead to spatiotemporal patterns, including traveling polar waves and nematic lanes. Recent experiments suggest that such patterns can also coexist and dynamically interconvert. Here we propose a general mechanism for such a phenomenology, which is based on patterned-induced local symmetry breaking. We show that macroscopic order in active-matter systems is linked to spatiotemporal density patterns, which in turn can lead to local symmetry breaking if the agent density exceeds the relevant threshold values. Our study sheds light on the principles of pattern formation and the emergence of symmetry in biological active-matter systems.
Refined measurement of SecA-driven protein secretion reveals that translocation is indirectly coupled to ATP turnover
Authors: Allen William J. , Watkins Daniel W. , Dillingham Mark S. , Collinson Ian
Published: December 2020

Significance

The transport of proteins across membranes is fundamental to all life. The biological machinery responsible for this process has been known for some time, but exactly how it works is still contested. In this paper, we describe how a new, high-precision method for measuring protein transport, combined with careful data analysis, can be used to solve this problem. We find that our transport data are best described by a ratchet-type mechanism, in which the protein can diffuse one way but not the other, rather than by physical pushing of the protein.
A thermogenic fat-epithelium cell axis regulates intestinal disease tolerance
Authors: Man Kevin , Bowman Christopher , Braverman Kristina N. , Escalante Veronica , Tian Yuan , Bisanz Jordan E. , Ganeshan Kirthana , Wang Biao , Patterson Andrew , Bayrer James R. , Turnbaugh Peter J. , Chawla Ajay
Published: December 2020

Significance

Disease tolerance is a host defense strategy that protects tissues from damage caused by pathogens or the immune system. While the importance of disease tolerance is well established in pathogenic infections, its role in tissue protection in noninfectious diseases remains less well understood. Here, we provide a framework for investigating the mechanisms of disease tolerance in experimental models of colitis. We find that the program of disease tolerance is preferentially expressed in thermoneutral mice, which protects them from injury-induced colitis and inflammation-induced colon cancer. The expression of intestinal disease tolerance is mediated by an unexpected cross-talk between thermogenic adipocytes and intestinal epithelial cells, suggesting that disease tolerance programs are metabolically expensive and dependent on the energetic state of the host.
Regulatory mechanisms of tau protein fibrillation under the conditions of liquid–liquid phase separation
Authors: Boyko Solomiia , Surewicz Krystyna , Surewicz Witold K.
Published: December 2020

Significance

One of the major pathogenic events in Alzheimer’s disease and several other neurodegenerative disorders is the aggregation of tau protein into fibrillar structures. Recent reports demonstrated that tau can undergo liquid–liquid phase separation, forming liquid droplets. The key finding of the present study is that liquid–liquid phase separation uniquely regulates the rate of tau fibrillation in mixtures containing tau isoforms with different aggregation propensities. Given that, due to alternative splicing, the proportions of fast and slowly aggregating tau isoforms in brain vary substantially in different tauopathies, this previously unrecognized regulatory mechanism may play an important role as one of the major determinants of phenotypic variability within this class of neurodegenerative diseases.
Targeting progesterone signaling prevents metastatic ovarian cancer
Authors: Kim Olga , Park Eun Young , Kwon Sun Young , Shin Sojin , Emerson Robert E. , Shin Yong-Hyun , DeMayo Francesco J. , Lydon John P. , Coffey Donna M. , Hawkins Shannon M. , Quilliam Lawrence A. , Cheon Dong-Joo , Fernández Facundo M. , Nephew Kenneth P. , Karpf Adam R. , Widschwendter Martin , Sood Anil K. , Bast Robert C. , Godwin Andrew K. , Miller Kathy D. , Cho Chi-Heum , Kim Jaeyeon
Published: December 2020

Significance

Why women carrying a pathogenic germlineBRCA1mutation are predisposed to ovarian and breast cancer remains elusive. This study points to ovarian progesterone as a culprit. Generally,BRCA1-mutation carriers exhibit high yet individually varying levels of progesterone during the menstrual cycle. Although not allBRCA1-mutation carriers develop these cancers, all of them are advised to undergo prophylactic surgeries at a young age (under 40 y to 45 y) to prevent ovarian and breast cancer. Insights from robust in vivo findings in this study offer a novel concept: Targeting progesterone signaling with antiprogestins could be an effective nonsurgical prophylactic option for ovarian and breast cancer prevention for these high-risk women.
Viewing rare conformations of the β
2
adrenergic receptor with pressure-resolved DEER spectroscopy
Authors: Lerch Michael T. , Matt Rachel A. , Masureel Matthieu , Elgeti Matthias , Kumar Kaavya Krishna , Hilger Daniel , Foys Bryon , Kobilka Brian K. , Hubbell Wayne L.
Published: December 2020

Significance

The molecular origin of basal activity in G protein coupled receptors and its suppression by inverse agonists are poorly understood. Here we employ pressure-resolved DEER spectroscopy to explore the structural origin of basal activity and the mechanism of inverse agonism in the β
2
adrenergic receptor. Collectively, the results support a conformational selection model wherein basal activity is due to a preexisting equilibrium between inactive and active conformations in the unliganded receptor, and inverse agonists stabilize the inactive conformation. Furthermore, the results illustrate the importance of rare states in molecular mechanisms of protein function and the capability of pressure-resolved DEER for revealing structural features of sparsely populated conformations of membrane proteins and for determining their thermodynamic properties.
Functional characterization of 67 endocytic accessory proteins using multiparametric quantitative analysis of CCP dynamics
Authors: Bhave Madhura , Mino Rosa E. , Wang Xinxin , Lee Jeon , Grossman Heather M. , Lakoduk Ashley M. , Danuser Gaudenz , Schmid Sandra L. , Mettlen Marcel
Published: December 2020

Significance

Clathrin-mediated endocytosis (CME), the major pathway for uptake into cells, is a multistep process involving a myriad of endocytic accessory proteins (EAPs). Although the biochemical activities of many EAPs have been extensively studied, their stage-specific role(s) during clathrin-coated pit (CCP) initiation, stabilization, and/or maturation are poorly defined. Here, using quantitative total internal reflection fluorescence microscopy and a rigorous experimental and multiparametric analytical pipeline, we study the effect of CRISPR interference (CRISPRi)- or small interfering RNA (siRNA)-mediated knockdown of 67 individual EAPs on CCP dynamics. Our comprehensive analyses combined with unsupervised phenotypic clustering reveal the complex and overlapping roles of EAPs during early, critical stages of CME, providing a valuable resource to spur further research into their function.
Typology of functional domains
Authors: Frajzyngier Zygmunt
Published: December 2020

The aim of this study is to advocate one of the aims of linguistic typology, viz. the discovery of how languages are similar or different with respect to the functions they encode and consequently for the development of a typology based solely on the functions encoded in the grammatical systems of individual languages. Such a typology has the advantage of not requiring or depending on aprioristic definitions.1 Such a typology also has the following additional advantages: it can serve as a tool in explaining the forms of utterances in individual languages and in explaining why certain languages have functions that other languages do not.
The non-universality of linguistic categories
Authors: Mattiola Simone
Published: December 2020

This paper aims at giving a typological overview of pluractionality in order to show how grammatical categories, in cross-linguistic perspective, cannot be considered as universally valid entities. After having defined the phenomenon, I will present the main functions and some formal characteristics that pluractional markers have in the languages of the world. Then, I will describe the diachronic sources from which pluractional markers probably come from. Finally, I will discuss the grammatical status that pluractionality has in cross-linguistic perspective in the light of the broad variety it shows in the languages of the world and also taking into consideration data from specific languages.
Dynamics in wormhole spacetimes: a Jacobi metric approach
Authors: Argañaraz Marcos , Andino Oscar Lasso
Published: December 2020

This article deals with the study of the dynamics of particles in different wormhole geometries. Using the Jacobi metric approach we study the geodesic motion on the Morris–Thorne wormhole. We found the only stable circular orbit located at the throat. We show that the Gaussian curvature of the Jacobi metric is directly related with the wormhole flare-out condition. We provide a simple test for determining the existence of a throat in a spacetime by using the Gaussian curvature of the associated Jacobi metric only. We discuss about the trajectories in the Kepler problem in a wormhole background. Finally, we discuss about the restrictions over the stress–energy tensor imposed by the existence of elliptic orbits in the Kepler problem.
Electron–phonon coupling in APd3O4: A = Ca, Sr, and Sr0.85Li0.15
Authors: Poojitha Bommareddy , Reddy B H , Joshi Aprajita , Kumar Ankit , Ali Asif , Singh R S , Saha Surajit
Published: December 2020

Here we have investigated the role of electron phonon coupling on the Raman spectrum of narrow bandgap semiconductors APd3O4 (A = Ca, Sr) and hole-doped system Sr0.85Li0.15Pd3O4. Four Raman active phonons are observed at room temperature for all three compounds as predicted by factor group analysis. The lowest energy phonon (∼190/202 cm−1) associated with Pd vibrations is observed to exhibit an asymmetric Fano-like lineshape in all the three compounds, indicating the presence of an interaction between the phonon and the electronic continuum. The origin of the electronic continuum states and electron–phonon coupling are discussed based on our laser power- and temperature-dependent Raman results. We have observed an enhanced strength of electron–phonon coupling in Sr0.85Li0.15Pd3O4 at low temperatures which can be attributed to the metallicity in this doped compound.
Perovskite-inspired materials for photovoltaics and beyond—from design to devices
Authors: Huang Yi-Teng , Kavanagh Seán R , Scanlon David O , Walsh Aron , Hoye Robert L Z
Published: December 2020

Lead-halide perovskites have demonstrated astonishing increases in power conversion efficiency in photovoltaics over the last decade. The most efficient perovskite devices now outperform industry-standard multi-crystalline silicon solar cells, despite the fact that perovskites are typically grown at low temperature using simple solution-based methods. However, the toxicity of lead and its ready solubility in water are concerns for widespread implementation. These challenges, alongside the many successes of the perovskites, have motivated significant efforts across multiple disciplines to find lead-free and stable alternatives which could mimic the ability of the perovskites to achieve high performance with low temperature, facile fabrication methods. This Review discusses the computational and experimental approaches that have been taken to discover lead-free perovskite-inspired materials, and the recent successes and challenges in synthesizing these compounds. The atomistic origins of the extraordinary performance exhibited by lead-halide perovskites in photovoltaic devices is discussed, alongside the key challenges in engineering such high-performance in alternative, next-generation materials. Beyond photovoltaics, this Review discusses the impact perovskite-inspired materials have had in spurring efforts to apply new materials in other optoelectronic applications, namely light-emitting diodes, photocatalysts, radiation detectors, thin film transistors and memristors. Finally, the prospects and key challenges faced by the field in advancing the development of perovskite-inspired materials towards realization in commercial devices is discussed.
Improved wettability and enhanced ionic transport in highly porous CNT sponge
Authors: Yao Sicheng , Zhou Shenglin , Zhang Jiapeng , Yang Zhaohui , Zhang Xiaohua
Published: December 2020

We investigated the effect of an electric treatment on the wettability of aqueous solution on carbon nanotubes (CNT) and ion transport behaviors in superhydrophobic porous carbon nanotube sponges (CNTS). This electric activation treatment where an electric voltage was applied across highly porous CNT sponge induced an electrowetting effect. This effect significantly reduced interfacial tensions between CNT sidewalls and aqueous liquids. Meanwhile, polar functional groups were also introduced on CNTs. Both electrowetting effect and polar functional groups greatly improved the wettability of aqueous solutions on CNT sidewalls. After the electric treatment, we observed a dramatic increase in the overall rate of ion flow across porous CNT sponges. The formation of solution channels during the electric treatment is responsible for the enhanced ionic transport in porous CNT sponges. The overall rate of ion flow increased with the increases in electric treatment time and voltage. The crucial role of electric treatment parameters in the ion transport provides a new strategy for precisely controlling the ion transport across CNT sponges by tuning electric treatment time or voltage. Importantly, the good wettability of aqueous solution on CNT sidewalls greatly increased the effective surface area of CNT sponges and thus significantly improved the performance of CNTS-based supercapacitors after the electric treatment.
The calculation of kinetic and static friction coefficient and friction graph analysis using Arduino
Authors: Çoban Atakan , Boyacı Seher
Published: December 2020

In this study, with the help of the Arduino UNO and load-cell force sensor, a simple experimental material has been developed to calculate kinetic and static friction coefficients and analyse the friction force in detail. The system with a force sensor mounted on it is placed on the plane. With the help of the rope attached to the force sensor, a force, whose magnitude increased over time, was applied on the sensor. After the force applied was large enough to move the system, the force was applied to move the system at a constant speed. Since the net force acting on the system is zero while the system is stationary and moving with a constant speed, in these cases the magnitudes of force read through the sensor are equal to the static and kinetic friction forces acting on the object. Using these static and kinetic friction forces values, the maximum value of the static friction coefficient and the kinetic friction coefficient were calculated as 0.484 and 0.313, respectively.
Absence of Severe Acute Respiratory Syndrome Coronavirus 2 Neutralizing Activity in Prepandemic Sera From Individuals With Recent Seasonal Coronavirus Infection
Authors: Poston Daniel , Weisblum Yiska , Wise Helen , Templeton Kate , Jenks Sara , Hatziioannou Theodora , Bieniasz Paul
Published: December 2020

Cross-reactive immune responses elicited by seasonal coronaviruses might affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) susceptibility and disease outcomes. We measured neutralizing activity against SARS-CoV-2 in prepandemic sera from patients with prior polymerase chain reaction scan-confirmed seasonal coronavirus infection. Although neutralizing activity against seasonal coronaviruses was detected in nearly all sera, cross-reactive neutralizing activity against SARS-CoV-2 was undetectable.
Comparison of Estimated Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Through Commercial Laboratory Residual Sera Testing and a Community Survey
Authors: Bajema Kristina L , Dahlgren F Scott , Lim Travis W , Bestul Nicolette , Biggs Holly M , Tate Jacqueline E , Owusu Claudio , Szablewski Christine M , Drenzek Cherie , Drobeniuc Jan , Semenova Vera , Li Han , Browning Peter , Desai Rita , Epperson Monica , Jia Lily T , Thornburg Natalie J , Edens Chris , Fry Alicia M , Hall Aron J , Schiffer Jarad , Havers Fiona P
Published: December 2020

We compared severe acute respiratory syndrome coronavirus 2 seroprevalence estimated from commercial laboratory residual sera and a community household survey in metropolitan Atlanta during April and May 2020 and found these 2 estimates to be similar (4.94% vs 3.18%). Compared with more representative surveys, commercial sera can provide an approximate measure of seroprevalence.
Knowledge, opinions and attitudes of primary care physicians about generic drugs: a cross-sectional study
Authors: Oncu Seyma , Bayram Dilara , Aydin Volkan , Isli Fatma , Aksoy Mesil , Akici Ahmet , Ucku Reyhan , Gelal Ayse
Published: December 2020

Background

Generic drug (GD) use is affected by many factors, including physicians’ approach.

Objective

This study aimed to investigate the knowledge, opinions and attitudes of primary care physicians (PCPs) about GDs and potentially associated factors.

Methods

An adequately representative sample (n = 354) of PCPs was determined via stratified and simple random sample selection method in this descriptive, cross-sectional study. The research data were collected through a face-to-face 40-item survey, where the knowledge, opinions and attitudes about GDs were questioned. The prescribing percentage of GDs overall was also examined.

Results

The survey was completed by 305 PCPs (mean age: 49.2 ± 7.9 years; 57.4% male). The rate of correct responses about GDs was 67.6% for basic knowledge and 46.6% for the development process. The percentages of PCPs who declared that GDs were ‘less efficacious’, ‘of lower quality’ and ‘less safe’ than original drugs were 65.2%, 53.4% and 35.4%, respectively. More than half (60.3%) of the PCPs declared not to pay attention to whether the drug is generic while prescribing. It was observed that, as the knowledge level of the physicians increased, negative opinions and prescribing attitudes regarding the effectiveness, quality and safety of the GDs decreased. The rate of GD prescribing (51.6%) in Izmir was lower than the rest of the country (54.6%; P < 0.001).

Conclusion

This study shows that the knowledge of PCPs about GDs is generally inadequate, which reflects negatively on their opinions and attitudes regarding the use of GDs. Educational activities can help establish awareness that GDs can be used without doubt of their effectiveness, quality and safety.
The 25 October 2018 Zakynthos (Greece) earthquake: seismic activity at the transition between a transform fault and a subduction zone
Authors: Papadimitriou P , Kapetanidis V , Karakonstantis A , Spingos I , Pavlou K , Kaviris G , Kassaras I , Sakkas V , Voulgaris N
Published: December 2020

The properties of the Mw = 6.7 earthquake that took place on 25 October 2018, 22:54:51 UTC, ∼50 km SW of the Zakynthos Island, Greece, are thoroughly examined. The main rupture occurred on a dextral strike-slip, low-angle, east-dipping fault at a depth of 12 km, as determined by teleseismic waveform modelling. Over 4000 aftershocks were manually analysed for a period of 158 d. The events were initially located with an optimal 1D velocity model and then relocated with the double-difference method to reveal details of their spatial distribution. The latter spreads in an area spanning 80 km NNW–SSE and ∼55 km WSW–ENE. Certain parts of the aftershock zone present strong spatial clustering, mainly to the north, close to Zakynthos Island, and at the southernmost edge of the sequence. Focal mechanisms were determined for 61 significant aftershocks using regional waveform modelling. The results revealed characteristics similar to the main shock, with few aftershocks exhibiting strike-slip faulting at steeper dip angles, possibly related to splay faults on the accretionary prism. The slip vectors that correspond to the east-dipping planes are compatible with the long-term plate convergence and with the direction of coseismic displacement on the Zakynthos Island. Fault-plane solutions in the broader study area were inverted for the determination of the regional stress-field. The results revealed a nearly horizontal, SW–NE to E–W-trending S1 and a more variable S3 axis, favouring transpressional tectonics. Spatial clusters at the northern and southern ends of the aftershock zone coincide with the SW extension of subvertical along-dip faults of the segmented subducting slab. The main shock occurred in an area where strike-slip tectonics, related to the Cephalonia Transform Fault and the NW Peloponnese region, gradually converts into reverse faulting at the western edge of the Hellenic subduction. Plausible scenarios for the 2018 Zakynthos earthquake sequence include a rupture on the subduction interface, provided the slab is tilted eastwards in that area, or the reactivation of an older east-dipping thrust as a low-angle strike-slip fault that contributes to strain partitioning.
Geodynamic tomography: constraining upper-mantle deformation patterns from Bayesian inversion of surface waves
Authors: Magali J K , Bodin T , Hedjazian N , Samuel H , Atkins S
Published: December 2020

In the Earth’s upper mantle, seismic anisotropy mainly originates from the crystallographic preferred orientation (CPO) of olivine due to mantle deformation. Large-scale observation of anisotropy in surface wave tomography models provides unique constraints on present-day mantle flow. However, surface waves are not sensitive to the 21 coefficients of the elastic tensor, and therefore the complete anisotropic tensor cannot be resolved independently at every location. This large number of parameters may be reduced by imposing spatial smoothness and symmetry constraints to the elastic tensor. In this work, we propose to regularize the tomographic problem by using constraints from geodynamic modelling to reduce the number of model parameters. Instead of inverting for seismic velocities, we parametrize our inverse problem directly in terms of physical quantities governing mantle flow: a temperature field, and a temperature-dependent viscosity. The forward problem consists of three steps: (1) calculation of mantle flow induced by thermal anomalies, (2) calculation of the induced CPO and elastic properties using a micromechanical model, and (3) computation of azimuthally varying surface wave dispersion curves. We demonstrate how a fully nonlinear Bayesian inversion of surface wave dispersion curves can retrieve the temperature and viscosity fields, without having to explicitly parametrize the elastic tensor. Here, we consider simple flow models generated by spherical temperature anomalies. The results show that incorporating geodynamic constraints in surface wave inversion help to retrieve patterns of mantle deformation. The solution to our inversion problem is an ensemble of models (i.e. thermal structures) representing a posterior probability, therefore providing uncertainties for each model parameter.
The impact of economic recessions on health workers: a systematic review and best-fit framework synthesis of the evidence from the last 50 years
Authors: Russo Giuliano , Silva Tiago Jesus , Gassasse Zakariah , Filippon Jonathan , Rotulo Arianna , Kondilis Elias
Published: December 2020

Economic crises carry a substantial impact on population health and health systems, but little is known on how these transmit to health workers (HWs). Addressing such a gap is timely as HWs are pivotal resources, particularly during pandemics or the ensuing recessions. Drawing from the empirical literature, we aimed to provide a framework for understanding the impact of recessions on HWs and their reactions. We use a systematic review and best-fit framework synthesis approach to identify the relevant qualitative, quantitative and mixed-methods evidence, and refine an a priori, theory-based conceptual framework. Eight relevant databases were searched, and four reviewers employed to independently review full texts, extract data and appraise the quality of the evidence retrieved. A total of 57 peer-reviewed publications were included, referring to six economic recessions. The 2010–15 Great Recession in Europe was the subject of most (52%) of the papers. Our consolidated framework suggests that recessions transmit to HWs through three channels: (1) an increase in the demand for services; (2) the impacts of austerity measures; and (3) changes in the health labour market. Some of the evidence appeared specific to the context of crises; demand for health services and employment increased during economic recessions in North America and Oceania, but stagnated or declined in Europe in connection with the austerity measures adopted. Burn-out, lay-offs, migration and multiple jobholding were the reactions observed in Europe, but job opportunities never dwindled for physicians during recessions in North America, with nurses re-entering labour markets during such crises. Loss of motivation, absenteeism and abuse of health systems were documented during recessions in low-income countries. Although the impacts of recessions may vary across economic events, health systems, labour markets and policy responses, our review and framework provide an evidence base for policies to mitigate the effects on HWs.
‘Sweet talk’: framing the merits of a sugar tax in Australia
Authors: Anaf Julia , Fisher Matthew , Handsley Elizabeth , Baum Fran , Friel Sharon
Published: December 2020

Although rising rates of obesity are recognized as a major concern for Australian public health, debate on what (if any) responsive action should be undertaken is conceptually and normatively complex. It is shaped by diverse values and interests; different representations of the problem; and many options for action by government, the private sector or individuals. This paper presents research documenting arguments for and against implementing a sugar tax in Australia. It is based on semi-structured interviews with representatives from industry (n = 4), public health (n = 4), policy think tanks (n = 2); and document and media analyses. The research design was informed by framing and agenda setting theory with results reported under four main themes: framing economic impacts, framing equity, framing obesity and framing the ‘nanny state’ versus individual liberty argument. We found that proposals for a sugar tax as part of policy responses to the issue of overweight and obesity in Australia are framed very differently by actors who either support or oppose it. A conclusion is that policy makers and public health advocates involved in policy debates on a sugar tax need to understand the role of problem and ‘solution’ framing, and develop positions based on protecting the public interest as a basic ethical responsibility of governments and public agencies.
Drug–drug interaction between itraconazole capsule and efavirenz in adults with HIV for talaromycosis treatment
Authors: Kaewpoowat Quanhathai , Chaiwarith Romanee , Yasri Saowaluck , Worasilchai Navaporn , Chindamporn Ariya , Sirisanthana Thira , Cressey Tim R
Published: December 2020

Objectives

To assess the pharmacokinetic of itraconazole capsule formulation and its active metabolite, hydroxyitraconazole, in adults with HIV diagnosed with talaromycosis in an endemic area, and to evaluate the drug–drug interaction between itraconazole/hydroxyitraconazole (ITC/OH-ITC) and efavirenz.

Methods

Open-label, single arm, sequential pharmacokinetic study. Eligible subjects were adults with HIV, ≥18 years old, with confirmed talaromycosis, initiating itraconazole capsule as part of standard talaromycosis treatment, in whom efavirenz-based ART was anticipated. Steady-state pharmacokinetic assessments (pre-dose and at 1, 3, 4, 5, 6, 8 and 12 h post dose) were performed for itraconazole/hydroxyitraconazole without and with efavirenz use. Mid-dose efavirenz concentrations were also assessed. Pharmacokinetics parameters were calculated using non-compartmental analysis.

Results

Ten subjects (70% male) were enrolled. At entry, median (range) age was 29.5 years (22–64), and CD4 cell count was 18.0 (1–39) cells/mm3. Geometric mean (95% CI) of itraconazole and hydroxyitraconazole AUC0–12 without efavirenz were 9097 (6761–12 239) and 11 705 (8586-15 959) ng·h/mL, respectively, with a median metabolic ratio of OH-ITC : ITC of 1.3 (95% CI 0.9–1.9). Intra-subject comparison revealed that both itraconazole and hydroxyitraconazole exposures were significantly reduced with concomitant efavirenz use, with the mean AUC0–12 of itraconazole and hydroxyitraconazole being 86% (71%–94%) and 84% (64%–97%) lower, respectively. With efavirenz, itraconazole trough concentrations were also below the recommended therapeutic level (0.5 μg/mL). All subjects had mid-dose efavirenz concentrations >1000 ng/mL.

Conclusions

Concomitant administration of itraconazole capsule with efavirenz significantly reduced itraconazole and hydroxyitraconazole exposures. The clinical impact of this drug–drug interaction on talaromycosis treatment or prophylaxis in the era of potent ART needs further evaluation.
Beyond-Newtonian dynamics of a planar circular restricted three-body problem with Kerr-like primaries
Authors: De Shounak , Roychowdhury Suparna , Banerjee Roopkatha
Published: December 2020

The dynamics of the planar circular restricted three-body problem with Kerr-like primaries in the context of a beyond-Newtonian approximation is studied. The beyond-Newtonian potential is developed by using the Fodor–Hoenselaers–Perjés procedure. An expansion in the Kerr potential is performed and terms up to the first non-Newtonian contribution of both the mass and spin effects are included. With this potential, a model for a test particle of infinitesimal mass orbiting in the equatorial plane of the two primaries is examined. The introduction of a parameter, ϵ, allows examination of the system as it transitions from the Newtonian to the beyond-Newtonian regime. The evolution and stability of the fixed points of the system as a function of the parameter ϵ is also studied. The dynamics of the particle is studied using the Poincaré map of section and the Maximal Lyapunov Exponent as indicators of chaos. Intermediate values of ϵ seem to be the most chaotic for the two cases of primary mass ratios (=0.001, 0.5) examined. The amount of chaos in the system remains higher than the Newtonian system as well as for the planar circular restricted three-body problem with Schwarzschild-like primaries for all non-zero values of ϵ.
The awakening beast in the Seyfert 1 Galaxy KUG 1141+371 – I
Authors: Jiang Jiachen , Cheng Huaqing , Gallo Luigi C , Ho Luis C , Buisson Douglas J K , Fabian Andrew C , Harrison Fiona A , Parker Michael L , Reynolds Christopher S , Steiner James F , Tomsick John A , Walton Dominic J , Yuan Weimin
Published: December 2020

KUG 1141+371 is a Seyfert 1 galaxy that shows a simultaneous flux increase in the optical and UV bands in the past decade. For instance, the latest Swift observation in 2019 shows that the UVW2 flux of the active galactic nucleus in KUG 1141+371 has increased by over one order of magnitude since 2009. Meanwhile, the soft X-ray flux of KUG 1141+371 also shows a steady increase by one order of magnitude since 2007. The significant multiwavelength luminosity change is likely due to a boost of mass accretion rate from approximately $0.6{{\ \rm per\ cent}}$ of the Eddington limit to $3.2{{\ \rm per\ cent}}$, assuming a black hole mass of 108 M⊙. In this work, we conduct detailed multi-epoch X-ray spectral analysis focusing on the variability of the X-ray continuum emission and the puzzling soft excess emission. In addition, our SED models also suggest a simultaneous increase of disc temperature and a decreasing inner disc radius along with the increasing accretion rate. Finally, we discuss possible connection between KUG 1141+371 and black hole transients in outburst.
Galaxy clustering in the DESI Legacy Survey and its imprint on the CMB
Authors: Hang Qianjun , Alam Shadab , Peacock John A , Cai Yan-Chuan
Published: December 2020

We use data from the DESI Legacy Survey imaging to probe the galaxy density field in tomographic slices covering the redshift range 0 < z < 0.8. After careful consideration of completeness corrections and galactic cuts, we obtain a sample of 4.9 × 107 galaxies covering 17 739 deg2. We derive photometric redshifts with precision σz/(1 + z) = 0.012−0.015, and compare with alternative estimates.1 Cross-correlation of the tomographic galaxy maps with Planck maps of cosmic microwave background (CMB) temperature and lensing convergence probe the growth of structure since z = 0.8. The signals are compared with a fiducial Planck ΛCDM model, and require an overall scaling in amplitude of Aκ = 0.901 ± 0.026 for the lensing cross-correlation and AISW = 0.984 ± 0.349 for the temperature cross-correlation, interpreted as the integrated Sachs–Wolfe effect. The ISW amplitude is consistent with the fiducial Λ cold dark matter (ΛCDM) prediction, but lies significantly below the prediction of the AvERA model of Rácz et al., which has been proposed as an alternative explanation for cosmic acceleration. Within ΛCDM, our low amplitude for the lensing cross-correlation requires a reduction either in fluctuation normalization or in matter density compared to the Planck results, so that $\Omega _\mathrm{ m}^{0.78}\sigma _8=0.297\pm 0.009$. In combination with the total amplitude of CMB lensing, this favours a shift mainly in density: Ωm = 0.274 ± 0.024. We discuss the consistency of this figure with alternative evidence. A conservative compromise between lensing and primary CMB constraints would require Ωm = 0.296 ± 0.006, where the 95 per cent confidence regions of both probes overlap.
Starlight coupling through atmospheric turbulence into few-mode fibres and photonic lanterns in the presence of partial adaptive optics correction
Authors: Diab Momen , Dinkelaker Aline N , Davenport John , Madhav Kalaga , Roth Martin M
Published: December 2020

Starlight corrupted by atmospheric turbulence cannot couple efficiently into astronomical instruments based on integrated optics as they require light of high spatial coherence to couple into their single-mode waveguides. Low-order adaptive optics in combination with photonic lanterns offer a practical approach to achieve efficient coupling into multiplexed astrophotonic devices. We investigate, aided by simulations and an experimental testbed, the trade-off between the degrees of freedom of the adaptive optics system and those of the input waveguide of an integrated optic component leading to a cost-effective hybrid system that achieves a signal-to-noise ratio higher than a standalone device fed by a single-mode fibre.
Cloud-by-cloud, multiphase, Bayesian modelling: application to four weak, low-ionization absorbers
Authors: Sameer  , Charlton Jane C , Norris Jackson M , Gebhardt Matthew , Churchill Christopher W , Kacprzak Glenn G , Muzahid Sowgat , Narayanan Anand , Nielsen Nikole M , Richter Philipp , Wakker Bart P
Published: December 2020

We present a new method aimed at improving the efficiency of component by component ionization modelling of intervening quasar absorption-line systems. We carry out cloud-by-cloud, multiphase modelling making use of cloudy and Bayesian methods to extract physical properties from an ensemble of absorption profiles. Here, as a demonstration of method, we focus on four weak, low-ionization absorbers at low redshift, because they are multiphase but relatively simple to constrain. We place errors on the inferred metallicities and ionization parameters for individual clouds, and show that the values differ from component to component across the absorption profile. Our method requires user input on the number of phases and relies on an optimized transition for each phase, one observed with high resolution and signal-to-noise ratio. The measured Doppler parameter of the optimized transition provides a constraint on the Doppler parameter of H i, thus providing leverage in metallicity measurements even when hydrogen lines are saturated. We present several tests of our methodology, demonstrating that we can recover the input parameters from simulated profiles. We also consider how our model results are affected by which radiative transitions are covered by observations (for example, how many H i transitions) and by uncertainties in the b parameters of optimized transitions. We discuss the successes and limitations of the method, and consider its potential for large statistical studies. This improved methodology will help to establish direct connections between the diverse properties derived from characterizing the absorbers and the multiple physical processes at play in the circumgalactic medium.