bluuebunny/crossref_metadata_2025 huggingface dataset:
Diamond encapsulated silicon optical fibers synthesized by chemical vapor deposition
Authors: Hendrickson Alex T. , Hemawan Kadek W. , Coco Michael G. , Aro Steve C. , McDaniel Sean A. , Sazio Pier J. , Cook Gary , Badding John V. , Hemley Russell J.
Published: September 2020

Semiconductor optical fibers encapsulated in a protective diamond coating can theoretically lead to immense power handling capabilities and infrared functionality. Here, silicon optical fibers are grown using high pressure chemical vapor deposition before being coated by 50 μm–300 μm of diamond by microwave plasma-assisted chemical vapor deposition. This coating extends conformally around the fiber cross section with diamond crystallites in the film on the order of several micrometers. Complete coating of high-quality diamond around the fiber is indicated by scanning electron microscopy and Raman measurements. The encapsulated silicon fibers are durable enough to survive the diamond deposition process, as demonstrated by their ability to guide infrared light.
Enhancement of EMI shielding effectiveness of flexible Co2U-type hexaferrite (Ba4Co2Fe36O60)-poly(vinylidene fluoride) heterostructure composite materials: An improved radar absorbing material to combat against electromagnetic pollution
Authors: Chakraborty Tanmoy , Debnath Tanumoy , Bhowmick Somashree , Bandyopadhyay Atul , Karmakar Arup , Das Sukhen , Mahapatra Abhik Sinha , Sutradhar Soumyaditya
Published: September 2020

In this report, for the first time, Co2U-type hexaferrite (Ba4Co2Fe36O60) nanomaterials have been considered along with their conjugation with a poly(vinylidene fluoride) (PVDF) matrix for the fabrication of heterostructure composite materials with superior electromagnetic interference shielding effectiveness (SE) that can produce better attenuation of microwave radiation. The high value of magnetizations of ∼7.21 and 10.63 emu/g is significant for the improvement of the shielding effectiveness due to absorption (SEA) of the composite materials. The unique combination of magnetic and dielectric responses of these Co2U-type hexaferrite nanomaterials helps to get significantly high total shielding effectiveness (SET) in their PVDF composite states within the frequency range of 8–18 GHz. A very high value of SET of approximately −83 dB at 14.2 GHz with >99.999 999% of attenuation of incident radiation has been observed for the Co2U-type hexaferrite–PVDF composite materials. The β-phase modified PVDF structure also plays the most important role to generate induced polarization inside the structure of composite materials. Also, this PVDF matrix provides the application friendly laminated structure of Co2U-type hexaferrite–PVDF composite materials. Structural, morphological, and chemical studies reveal the presence of the polycrystalline phase of Co2U-type hexaferrite and β-phase crystallization of polar PVDF in the multi-phase Co2U-type hexaferrite–PVDF composite materials. This study has helped us to understand the importance of magnetic Co2U-type hexaferrite nanomaterials for the fabrication of lightweight, large area, flexible, and thickness-controlled radar absorbing materials to combat against electromagnetic pollution.
Optical coherence tomography with a nonlinear interferometer in the high parametric gain regime
Authors: Machado Gerard J. , Frascella Gaetano , Torres Juan P. , Chekhova Maria V.
Published: September 2020

We demonstrate optical coherence tomography based on an SU(1,1) nonlinear interferometer with high-gain parametric downconversion. For imaging and sensing applications, this scheme promises to outperform previous experiments working at low parametric gain, since higher photon fluxes provide lower integration times for obtaining high-quality images. In this way, one can avoid using single-photon detectors or CCD cameras with very high sensitivities, and standard spectrometers can be used instead. Other advantages are higher sensitivity to small loss and amplification before detection so that the detected light power considerably exceeds the probing one.
Sound propagation in porous materials containing rough tubes
Authors: Xu Zhimin , He Wei , Xin Fengxian , Lu Tian Jian
Published: September 2020

A theoretical model is developed to quantify the influence of surface roughness on sound propagation in porous materials containing rough tubes by extending the Johnson–Champoux–Allard–Lafarge (JCAL) model. The five transport parameters of the JCAL model, including the viscous permeability, thermal permeability, tortuosity, viscous characteristic length, and thermal characteristic length, are calculated by modeling the rough tubes in the porous material as parallel rough tubes having idealized sinusoidal morphologies. The transport parameters obtained using the proposed model are validated by full finite element simulations. Based on these transport parameters, the sound absorption coefficient of the porous material containing idealized rough tubes is calculated, which agrees well with the FE result. The roughness effect is investigated by comparing sound absorption performance between parallel smooth tubes and parallel rough tubes. The existence of tube roughness weakens the thermal effect but dramatically strengthens the viscous effect in sound energy dissipation, resulting in enhanced sound absorption. This work provides fundamental insights on how surface roughness affects the acoustic performance of sound-absorbing porous materials.
Experimental investigation of the effect of a step and wedge on the performance of a high-speed craft in calm water and statistical analysis of its seakeeping in irregular waves
Authors: Sajedi Sayyed Mahdi , Ghadimi Parviz
Published: September 2020

Analysis of the hydrodynamic performance of a high-speed craft in calm water and seakeeping in irregular waves have attracted the attention of many researchers. In the current paper, experimental tests have been conducted on three mono-hull high-speed crafts in calm water and in the presence of irregular waves. The overall geometry of the tested vessels is the same with a length of 2.64 m and a beam of 0.551 m. They only differ in the presence of a wedge or transverse step. These vessels are stepped vessels and bare vessels with no appendage. Different parameters of trim, rise-up, and resistance are measured in calm water. In addition, heave and pitch motions, fore acceleration, and the center of gravity are extracted as time series. The irregular wave, which is modeled in sea force of 3, has a height of 12 cm and a peak to peak time period of 1.66 s. The tests are conducted for five different speeds ranging from 4 m/s to 8 m/s (equivalent of longitudinal Froude numbers between 0.857 and 1.71). Comprehensive comparisons have been presented between the stepped, wedged, and bare hulls. Based on the obtained results, it is concluded that the stepped vessel has less resistance in calm water compared to the two other models. The trim and resistance of the stepped model are 20% and 3% less than those of the models with no appendage, respectively. In terms of stability, the bare hull is longitudinally unstable at 8 m/s speed. However, the other two models are stable at this speed. On the other hand, the wedge mounted vessel exhibits less motion and acceleration than the other two models in irregular waves. Furthermore, the bow acceleration of the stepped and wedged models is 9% and 18% lower than that of the model with no appendage, respectively.
Convergence acceleration of Monte Carlo many-body perturbation methods by using many control variates
Authors: Doran Alexander E. , Hirata So
Published: September 2020

The use of many control variates is proposed as a method to accelerate the second- and third-order Monte Carlo (MC) many-body perturbation (MC-MP2 and MC-MP3) calculations. A control variate is an exactly integrable function that is strongly correlated or anti-correlated with the target function to be integrated by the MC method. Evaluating both integrals and their covariances in the same MC run, one can effect a mutual cancellation of the statistical uncertainties and biases in the MC integrations, thereby accelerating its convergence considerably. Six and thirty-six control variates, whose integrals are known a priori, are generated for MC-MP2 and MC-MP3, respectively, by systematically replacing one or more two-electron-integral vertices of certain configurations by zero-valued overlap-integral vertices in their Goldstone diagrams. The variances and covariances of these control variates are computed at a marginal cost, enhancing the overall efficiency of the MC-MP2 and MC-MP3 calculations by a factor of up to 14 and 20, respectively.
Hamiltonian and alias-free hybrid particle–field molecular dynamics
Authors: Bore Sigbjørn Løland , Cascella Michele
Published: September 2020

Hybrid particle–field molecular dynamics combines standard molecular potentials with density-field models into a computationally efficient methodology that is well-adapted for the study of mesoscale soft matter systems. Here, we introduce a new formulation based on filtered densities and a particle–mesh formalism that allows for Hamiltonian dynamics and alias-free force computation. This is achieved by introducing a length scale for the particle–field interactions independent of the numerical grid used to represent the density fields, enabling systematic convergence of the forces upon grid refinement. Our scheme generalizes the original particle–field molecular dynamics implementations presented in the literature, finding them as limit conditions. The accuracy of this new formulation is benchmarked by considering simple monoatomic systems described by the standard hybrid particle–field potentials. We find that by controlling the time step and grid size, conservation of energy and momenta, as well as disappearance of alias, is obtained. Increasing the particle–field interaction length scale permits the use of larger time steps and coarser grids. This promotes the use of multiple time step strategies over the quasi-instantaneous approximation, which is found to not conserve energy and momenta equally well. Finally, our investigations of the structural and dynamic properties of simple monoatomic systems show a consistent behavior between the present formulation and Gaussian core models.
Microstructure of YBa2Cu3Oy coated conductor using {100} ⟨001⟩ textured Cu tape with dual functions of metal substrate and electric stabilizing layer in order to develop low-cost high-TC superconducting wires
Authors: Ichinose Ataru , Hamada Tsuyoshi , Ota Keisuke , Kawayama Iwao , Doi Toshiya
Published: September 2020

A new configuration of coated conductors (CCs), REBa2Cu3Oy (RE: rare earth elements such as Sm, Eu, Gd, and Y)/(Sr, La)TiO3 conductive buffer/Ni-electroplated {100}⟨001⟩ textured Cu and SUS316 lamination tape, has been proposed to reduce material costs. This conductive buffer layer is slightly modified from the previously reported Sr (Ti, Nb)O3 conductive buffer layers by changing the substitution element and site. However, a drastic change is found in the electric resistivity of the conductive buffer layers after oxygen annealing of YBa2Cu3Oy. The resistivity of Sr(Ti, Nb)O3 conductive buffer layers increases by more than three orders of magnitude, while the resistivity of (Sr, La)TiO3 is almost maintained and only minimally increases. Microscopic structural analysis of the CCs using the newly proposed conductive buffer layer is conducted using transmission electron microscopy (TEM). A very clean interface between the metal tape and the conductive buffer layer in the 600 nm thick (Sr, La)TiO3 buffer layers is confirmed by the TEM analysis, which has no reactive layers as well as no inter-diffusion of oxygen and metal elements. This result will soon lead to the development of low-cost and high-performance CCs.
Unified simplified multiphase lattice Boltzmann method for ferrofluid flows and its application
Authors: Li Qiao-Zhong , Lu Zhi-Liang , Zhou Di , Niu Xiao-Dong , Guo Tong-Qin , Du Bing-Chen
Published: September 2020

A unified simplified multiphase lattice Boltzmann method (USMLBM) is constructed in this work for simulating complex multiphase ferrofluid flows with large density and viscosity ratios. In USMLBM, the Navier–Stokes equations, the Poisson equation of the magnetic potential, and the phase-field equation are utilized as the ferrohydrodynamics behavior modeling and interface tracking algorithm. Solutions of the macroscopic governing equations are reconstructed with the lattice Boltzmann framework and resolved in a predictor–corrector scheme. Various benchmark tests demonstrate the efficiency and accuracy of USMLBM in simulating multiphase ferrofluid flows. We further adopt USMLBM to analyze in detail the mechanisms of bubble merging inside a ferrofluid under a uniform external magnetic field. The numerical results indicate that the bubbles tend to move toward each other and further merge together, even for a large initial separation between the bubbles. Due to complex interaction between the bubbles and the ferrofluid during the magnetophoretic acceleration process, the nonlinear effect on bubble merging is observed when the initial separation increases. Moreover, at a larger initial separation, the shape of bubbles seems to be not sensitive to the initial separation.
Insight into Al2O3/B-doped diamond interface states with high-temperature conductance method
Authors: Zhang Xufang , Matsumoto Tsubasa , Sakurai Ukyo , Makino Toshiharu , Ogura Masahiko , Sometani Mitsuru , Yamasaki Satoshi , Nebel Christoph E. , Inokuma Takao , Tokuda Norio
Published: September 2020

We employed a high temperature conductance method to investigate the interface state properties of the Al2O3/B-doped diamond MOS structure by considering the surface potential fluctuation. Based on Gaussian approximation of Nicollian's model and Brew's graphical approach, we analyzed the frequency dependent characteristics of parallel conductance (Gp/ω–f) at various gate voltages and extracted the energy distribution of interface state density (Dit), capture cross section (σp), time constant (τit), and the standard deviation of surface potential fluctuation (σs). The Dit extracted by the conductance method exhibited good agreement with that by the high-low method, whereas there exist large errors when surface potential fluctuation was not considered by using the conductance method. The capture cross section extracted by the conductance method was on the order of 10−17 cm2. From the energy dependence of the interface state time constant, the hole capture and emission follow the Shockley–Read–Hall statistics. σs decreases with the energy position away from the valence band edge (Ev) of diamond, indicating that donor-like traps are distributed in the Ev side of diamond.
Monodispersed microbubble production using modified micro-Venturi bubble generator
Authors: Bhadran Vishnu , Goharzadeh Afshin
Published: September 2020

This paper presents an innovative method to produce controlled monodispersed bubbles using a modified micro-Venturi channel. The influence of flow control parameters such as liquid pressure and gas flow rate on the controlled generation of micro-bubbles was investigated. Experiments were conducted in a transparent modified micro-Venturi channel, having a depth of 40 μm, in which monodispersed gas bubbles were generated. The proposed design provides a new configuration to produce monodispersed microbubbles. Image analysis focused at the vena-contracta region showed that the geometry of generated microbubbles change suddenly from an ellipsoidal shape to a circular shape having a constant diameter. The dynamics of the bubble breakup mechanism in a modified micro-Venturi channel has been described. It was observed that the velocity and the size of the micro-bubbles were strongly dependent on the flow control parameters. The bubble frequency was linearly increasing with respect to gas mass flow rates.
Teaching About Electrostatics
Authors: Morse Robert A.
Published: September 2020

This book describes construction and use of reliable electrostatics equipment from inexpensive materials.

Appendix A: Electrostatics Activities for Students is a sample sequence of activities designed to help students build an initial understanding of electrostatics.

Appendix B: Ben Franklin’s Electrostatic Experiments recreates Franklin’s experiments for the classroom.
INTRODUCTION FOR WORKSHOP LEADERS
Authors: Morse Robert A.
Published: September 2020

The study of electrostatic phenomena has fascinated people since Greek times. Today, it is an important area of study in both science and technology. The large intrinsic strength of the electrical interaction means that relatively large forces can be obtained with relatively small charges, allowing students fairly direct experience with a fundamental force. The “magical” nature of the phenomena are exciting, but caution should be taken not to let the fun eclipse the physics. It is my belief that careful design of student activities in electrostatics can build the deeper fun of understanding nature through experiment. An excellent historical example lies in the work of Benjamin Franklin, who describes experiments and experiences which were clearly entertaining, but which had an underlying serious purpose, and led Franklin to a viable model of electrostatic phenomena. An excellent teaching unit by Rodney LaBrecque based on Franklin’s experiments is available in the AAPT Electrostatics Workshop (Morse, Toth & LaBrecque, 1991), and reprinted as Appendix B.
TEST QUESTIONS FOR ELECTROSTATICS
Authors: Morse Robert A.
Published: September 2020

There are several good sources of multiple choice test questions on electrostatics.
Graphs
Authors: Swartz Clifford E.
Published: September 2020

There are some general conventions about drawing graphs, most of them sensible. These are illustrated in the following pages. Adherence to the conventions is easy and is guaranteed to save time.

Data should usually be graphed as soon as they are obtained. Gross mistakes are not always apparent when the data are entered in tabular form. If, however, a graph of the data is being plotted while it is coming in, a point that is radically out of line is immediately obvious.
Statistics
Authors: Swartz Clifford E.
Published: September 2020

It is well known that figures can lie and liars can figure. The method most commonly used is called statistics. Statistics is the mathematical treatment and analysis of large quantities of data. It provides us with ways of characterizing the distribution of such data with a few parameters, such as averages. It also establishes rules for drawing samples from large amounts of data. All these rules are based on certain laws of probability and on requirements about the random nature of obtaining particular values of the variables. When the prior conditions on the data are not satisfied, the magnificent mathematical paraphernalia can produce errant nonsense. Statistics is the main analytical tool of some of the social sciences, particularly those connected with research in education.
Integration
Authors: Swartz Clifford E.
Published: September 2020

For every function useful in introductory science there is a derivative: dF(x)/dx = f(x). We call f(x) the derivative of F(x), and could also define F(x) as the antiderivative of f(x). By itself, however, F(x) is not unique. We could add any constant, so that d(F(x) + C)/dx = f(x). The total antiderivative of f(x) is thus F(x) + C.
Series and Approximations
Authors: Swartz Clifford E.
Published: September 2020

In most applications of science, as well as in everyday life, we seldom need precision better than one or two significant figures. (One exception is in reconciling bank statements.) Usually we can use approximations to functions if it is awkward to handle the function itself. In this section we present some examples of how simple functions can be used as approximations to complex ones.
OPTICS
Authors: Frier G. D. , Anderson F. J.
Published: September 2020

A commercial point source is used to project shadows of apparatus. There is a neglible penumbra, so that many experiments may be done in projection. For contrast the same objects may be projected by an ordinary light bulb. One can make a very good point source from some of the small auto lamps or pilot light lamps which have tightly wound filaments.
Women Physicists in Past Generations
Authors: Sopka Katherine Russell
Published: September 2020

For centuries, individual women in various countries have been attracted to the study of physics. Despite limited educational and employment opportunities, some of these women have succeeded in making significant contributions to the discipline through teaching, research, or, in at least one case, translation. The lives of the dozen female physicists whose work I will discuss span some twenty-four centuries, and they represent eight countries.
Lise Meitner’s Scientific Legacy
Authors: Watkins Sallie A.
Published: September 2020

Following her hasty flight from Nazi Germany to Sweden, Lise Meitner wrote to her former colleague, Otto Hahn: “One point which has not yet been discussed in detail is the question of my scientific ‘legacy.’ From my point of view, this is a central concern.” The discussion below will set forth the Meitner legacy. It will present accounts of the many contributions of Lise Meitner to physics, in particular to the field of nuclear physics. Where her work overlapped or complemented that of others, historical perspectives of the interplay will be dealt with.
Cecilia Payne-Gaposchkin: The Making of an Astrophysicist
Authors: Kidwell Peggy A.
Published: September 2020

This article will examine several aspects of the life and work of Cecilia Payne-Gaposchkin, a woman who was not a physicist but an astrophysicist. Payne was born in England in 1900 and studied physics as well as astronomy as an undergraduate at Cambridge University. She came to the United States in 1923 for a year’s postgraduate study at the Harvard College Observatory. Here she promptly began an investigation of the temperature and composition of stellar atmospheres that secured her the first Ph.D. in astronomy granted by Radcliffe College, a permanent post at the Harvard College Observatory, and an international reputation as an astrophysicist. Payne remained at Harvard for her entire career, achieving, at the ripe age of 56, a promotion from a lectureship to the rank of professor of astronomy, the first woman ever to be promoted to the rank of professor at Harvard. Payne-Gaposchkin wrote seven books as well as an autobiography and a host of technical papers and was quite probably the most eminent woman astronomer of all time. She married the Russian-born astronomer Sergei Gaposchkin in 1933 and mothered three children. In 1979, she died in Lexington, Massachusetts.
The Lady Wanted to Purchase a Wheatstone Bridge: Sarah Frances Whiting and Her Successor
Authors: Guernsey Janet B.
Published: September 2020

In the latter half of the nineteenth century, arguments raged about the education of women for anything other than wifehood and motherhood. Certainly there were isolated cases of parents, particularly fathers, who wanted their daughters to have as much “book learning” as their sons, and who recognized equal abilities among women and men. The general feeling, however, was that “woman’s brain was too delicate and fragile a thing to attempt the mastery of Greek and Latin …” It was said with some asperity that there would be two insane asylums and three hospitals for every women’s college.
Physics Laboratory Activity #1a Measurement of Speed
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

The purpose of the laboratory activity is to determine the average speed of a toy car moving with constant speed, and to compare the average speed to the final speed of the car.
Physics Laboratory Activity #21a Atomic Spectra of an Unknown Gas
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

In this laboratory activity observations are made of known and unknown spectra from elements. Two unknown gases are identified by measuring the wavelength of their spectral lines.
Physics Laboratory Activity #25a Electric Current and Magnetic Fields
Authors: Nelson Jim , Nelson Jane Bray
Published: September 2020

The purpose of this laboratory activity is to investigate the magnetic field produced by an electric current.
Computer Applications
Authors: Davids Mark , Rea R. Stephen , Zitzewitz Paul W.
Published: September 2020

At this time we do not know of any computer programs that would be useful in teaching about lightwave communications.
Background Material Transparency Masters
Authors: Franklin Bill
Published: September 2020

What you should learn from this section on color vision:
Demonstrations Displays
Authors: Franklin Bill
Published: September 2020

When first presenting the subject of bright-line spectra to my high-school chemistry class, I found that the concept of a color spectrum, not to mention the use of a spectroscope, was unfamiliar to the majority of students. I also found that physics students had some difficulty relating primary color addition concepts to what they had experienced with spectra generated by prisms and diffraction gratings. The overhead spectroscope described here introduces my chemistry students to the concept of spectrography and is also a useful demonstration tool for color analysis in my physics class.
Assignments Homework
Authors: Franklin Bill
Published: September 2020

The chapters in this manual divide color and color vision into four major topics:The eye and color vision; colors from mixing light or pigmentsThe colors of surfaces and light sources; absorption and emission, refraction, scattering, and diffraction and interferenceColors from interference involving diffraction and thin filmsColors from interference involving polarization
INTRODUCTION FOR WORKSHOP LEADERS
Authors: Reiland Robert J.
Published: September 2020

It is common for physics and physical science teachers to avoid the subject of magnetism because they are not comfortable with it. There are at least two obstacles that contribute to this discomfort. The first is that much of the magnetic phenomena that can be investigated in a school laboratory is counter-intuitive. In particular, action-at-a-distance effects and forces are often produced in unexpected directions. Given time, a teacher could produce experiments that would help students around this first obstacle if it wasn’t for the perceived dangers of such experiments. This is the second obstacle. The study of magnetism can, but need not, involve the use of dangerous amounts of electrical energy.
Properties of protein unfolded states suggest broad selection for expanded conformational ensembles
Authors: Bowman Micayla A. , Riback Joshua A. , Rodriguez Anabel , Guo Hongyu , Li Jun , Sosnick Tobin R. , Clark Patricia L.
Published: September 2020

Significance

Amino acid sequences are known to be crucial for specifying the folded structure of a protein. Here we show that sequences also play an important role in specifying the properties of a protein’s unfolded ensemble. For an autotransporter protein, rearranging the order of only a few percent of amino acid residues can lead to more collapsed unfolded ensembles which have enhanced aggregation in vitro and degradation in vivo. Sequences that remain expanded, however, are more compatible with proper function. Most significantly, we show that the well-mixed sequence patterns that lead to expanded ensembles are broadly conserved amongst foldable, water-soluble proteins, suggesting expanded disordered states are under selection.
Stable unmethylated DNA demarcates expressed genes and their cis-regulatory space in plant genomes
Authors: Crisp Peter A. , Marand Alexandre P. , Noshay Jaclyn M. , Zhou Peng , Lu Zefu , Schmitz Robert J. , Springer Nathan M.
Published: September 2020

Significance

Crop genomes can be very large, with many repetitive elements and pseudogenes. Distilling a genome down to the relatively small fraction of regions that are functionally valuable for trait variation can be like looking for needles in a haystack. The location of these regions is often not obvious, and current detection technologies are impractically expensive and intensive for many research projects. The unmethylated regions in a genome are highly stable during vegetative development and can reveal the locations of potentially expressed genes or cis-regulatory elements. This approach provides a framework toward complete annotation of genes and discovery of cis-regulatory elements using methylation profiles from only a single tissue.
Facilitating hydrogen atom migration via a dense phase on palladium islands to a surrounding silver surface
Authors: O’Connor Christopher R. , Duanmu Kaining , Patel Dipna A. , Muramoto Eri , van Spronsen Matthijs A. , Stacchiola Dario , Sykes E. Charles H. , Sautet Philippe , Madix Robert J. , Friend Cynthia M.
Published: September 2020

Significance

The energy efficiency of catalytic processes hinges on achieving high selectivity and activity; bimetallic catalysts have potential to increase both by exploiting different chemical properties of the components. Transport of intermediates between the two metals, for example, transport of hydrogen atoms for selective hydrogenation, is required to capitalize on this bifunctionality. A mechanism for the migration of hydrogen atoms to silver from palladium is demonstrated here. Dihydrogen first dissociates on palladium, then forms a dense hydrogen phase on the palladium island. The dense phase includes weakly bound hydrogen atoms that are nearly isoenergetic with hydrogen on silver, rendering migration nearly energy neutral. The efficiency for hydrogen migration across the palladium−silver is maximized for small ensembles of palladium atoms.
A rapid technique to integrate micro-components on released MEMS dies using SU-8
Authors: Gour Amit , Nabki Frederic , Ménard Michaël
Published: September 2020

This technical note reports a rapid technique to post-process and assemble micro-components onto dies including released movable microstructures. The method is applied to microelectromechanical systems (MEMS) chips that were fabricated using a commercial process, PolyMUMPs from MEMSCAP. It allows the assembly of a micro-polyhedron over released micromotors and ensures that the micromotors remain fully functional. The micro-polyhedrons are fabricated using laser ablation and are spin coated with a thin layer of SU-8, acting as a bonding layer. Then, they are bonded to chips that are placed on a 3D integration platform with a navigating mask, which protects the released structure during the subsequent assembly steps. The resulting micro-polyhedron-integrated-micromotors were tested and found to rotate similarly to devices without micro-polyhedrons, demonstrating that the developed procedure can be applied for post-release 3D integration of MEMS without significantly affecting the mechanical performance of the devices.
Between a rock and a hard place: State-led territorial stigmatization, informal care practices and the interstitiality of local community workers in Denmark
Authors: Birk Rasmus H , Arp Fallov Mia
Published: September 2020

The purpose of this paper is to explore the relation between territorial stigmatization and community work in Denmark. In the paper, we firstly explore territorial stigmatization, relating it to the Danish context. We show how territorial stigmatization in Denmark happens via a complex amalgamation of bureaucratic practices which identify particular areas as problematic ‘ghettos’, and how this leads to top–down interventions upon many local residential areas, including local community work. Following this, we draw on participant observations in practices of local community work, and interviews with local community workers, to explore how they practically negotiate these particular political constructions of their work. We argue that local community workers come to take on interstitial roles—that is, they come to be in-between the state and authorities and the local communities themselves. This complex double role is what we call an interstitial position, meant to signify how Danish local community workers are both part of territorial stigmatization and simultaneously trying to escape from and undo this very role.
Epic Victories and Failures: Homer and Vergil in Russia
Authors: Kalb Judith E. , Torlone Zara M.
Published: September 2020

This article focuses on selected complete Russian verse translations of Homer’s Iliad and Odyssey and of Vergil’s Aeneid produced over a period of nearly two centuries. By focusing on translation approach and goals, historical and cultural circumstances, and the literary talent of the translators, the authors explore the reasons for a particular translation’s success or failure. Further, they address the question of how Russian translators achieved canonical, or generally accepted, translations of the Homeric epics, while translations of Vergil’s epic found no such success.
Pleiotropic actions of factor Xa inhibition in cardiovascular prevention: mechanistic insights and implications for anti-thrombotic treatment
Authors: ten Cate Hugo , Guzik Tomasz J , Eikelboom John , Spronk Henri M H
Published: September 2020

Atherosclerosis is a chronic inflammatory disease in which atherothrombotic complications lead to cardiovascular morbidity and mortality. At advanced stages, myocardial infarction, ischaemic stroke, and peripheral artery disease, including major adverse limb events, are caused either by acute occlusive atherothrombosis or by thromboembolism. Endothelial dysfunction, vascular smooth muscle cell activation, and vascular inflammation are essential in the development of acute cardiovascular events. Effects of the coagulation system on vascular biology extend beyond thrombosis. Under physiological conditions, coagulation proteases in blood are pivotal in maintaining haemostasis and vascular integrity. Under pathological conditions, including atherosclerosis, the same coagulation proteases (including factor Xa, factor VIIa, and thrombin) become drivers of atherothrombosis, working in concert with platelets and vessel wall components. While initially atherothrombosis was attributed primarily to platelets, recent advances indicate the critical role of fibrin clot and plasma coagulation factors. Mechanisms of atherothrombosis and hypercoagulability vary depending on plaque erosion or plaque rupture. In addition to contributing to thrombus formation, factor Xa and thrombin can affect endothelial dysfunction, oxidative stress, vascular smooth muscle cell function as well as immune cell activation and vascular inflammation. By these mechanisms, they promote atherosclerosis and contribute to plaque instability. In this review, we first discuss the postulated vasoprotective mechanisms of protease-activated receptor signalling induced by coagulation enzymes under physiological conditions. Next, we discuss preclinical studies linking coagulation with endothelial cell dysfunction, thromboinflammation, and atherogenesis. Understanding these mechanisms is pivotal for the introduction of novel strategies in cardiovascular prevention and therapy. We therefore translate these findings to clinical studies of direct oral anticoagulant drugs and discuss the potential relevance of dual pathway inhibition for atherothrombosis prevention and vascular protection.
Sirtuin 5 promotes arterial thrombosis by blunting the fibrinolytic system
Authors: Liberale Luca , Akhmedov Alexander , Vlachogiannis Nikolaos I , Bonetti Nicole R , Nageswaran Vanasa , Miranda Melroy X , Puspitasari Yustina M , Schwarz Lena , Costantino Sarah , Paneni Francesco , Beer Jürg H , Ruschitzka Frank , Montecucco Fabrizio , Lüscher Thomas F , Stamatelopoulos Kimon , Stellos Konstantinos , Camici Giovanni G
Published: September 2020

Aims

Arterial thrombosis as a result of plaque rupture or erosion is a key event in acute cardiovascular events. Sirtuin 5 (SIRT5) belongs to the lifespan-regulating sirtuin superfamily and has been implicated in acute ischaemic stroke and cardiac hypertrophy. This project aims at investigating the role of SIRT5 in arterial thrombus formation.

Methods and results

Sirt5 transgenic (Sirt5Tg/0) and knock-out (Sirt5−/−) mice underwent photochemically induced carotid endothelial injury to trigger arterial thrombosis. Primary human aortic endothelial cells (HAECs) were treated with SIRT5 silencing-RNA (si-SIRT5) as well as peripheral blood mononuclear cells from acute coronary syndrome (ACS) patients and non-ACS controls (case–control study, total n = 171) were used to increase the translational relevance of our data. Compared to wild-type controls, Sirt5Tg/0 mice displayed accelerated arterial thrombus formation following endothelial-specific damage. Conversely, in Sirt5−/− mice, arterial thrombosis was blunted. Platelet function was unaltered, as assessed by ex vivo collagen-induced aggregometry. Similarly, activation of the coagulation cascade as assessed by vascular and plasma tissue factor (TF) and TF pathway inhibitor expression was unaltered. Increased thrombus embolization episodes and circulating D-dimer levels suggested augmented activation of the fibrinolytic system in Sirt5−/− mice. Accordingly, Sirt5−/− mice showed reduced plasma and vascular expression of the fibrinolysis inhibitor plasminogen activator inhibitor (PAI)-1. In HAECs, SIRT5-silencing inhibited PAI-1 gene and protein expression in response to TNF-α. This effect was mediated by increased AMPK activation and reduced phosphorylation of the MAP kinase ERK 1/2, but not JNK and p38 as shown both in vivo and in vitro. Lastly, both PAI-1 and SIRT5 gene expressions are increased in ACS patients compared to non-ACS controls after adjustment for cardiovascular risk factors, while PAI-1 expression increased across tertiles of SIRT5.

Conclusion

SIRT5 promotes arterial thrombosis by modulating fibrinolysis through endothelial PAI-1 expression. Hence, SIRT5 may be an interesting therapeutic target in the context of atherothrombotic events.
Wealth in Spain 1900–2017 A Country of Two Lands
Authors: Blanco Miguel Artola , Bauluz Luis , Martínez-Toledano Clara
Published: September 2020

This study reconstructs Spain’s national wealth from 1900 to 2017. By combining new sources with existing accounts, we estimate the wealth of both private and government sectors and use a new asset-specific decomposition of the long-run accumulation of wealth. We find that, during the twentieth century, the national wealth-to-income ratio remained within a relatively narrow range—between 400% and 600%—until the housing boom of the early 2000s led to an unprecedented rise to 800% in 2007. Our results highlight the importance of land, housing capital gains and international capital flows as key elements of wealth accumulation.
Bacteriophages as drivers of bacterial virulence and their potential for biotechnological exploitation
Authors: Schroven Kaat , Aertsen Abram , Lavigne Rob
Published: September 2020

Bacteria-infecting viruses (phages) and their hosts maintain an ancient and complex relationship. Bacterial predation by lytic phages drives an ongoing phage-host arms race, whereas temperate phages initiate mutualistic relationships with their hosts upon lysogenization as prophages. In human pathogens, these prophages impact bacterial virulence in distinct ways: by secretion of phage-encoded toxins, modulation of the bacterial envelope, mediation of bacterial infectivity and the control of bacterial cell regulation. This review builds the argument that virulence-influencing prophages hold extensive, unexplored potential for biotechnology. More specifically, it highlights the development potential of novel therapies against infectious diseases, to address the current antibiotic resistance crisis. First, designer bacteriophages may serve to deliver genes encoding cargo proteins which repress bacterial virulence. Secondly, one may develop small molecules mimicking phage-derived proteins targeting central regulators of bacterial virulence. Thirdly, bacteria equipped with phage-derived synthetic circuits which modulate key virulence factors could serve as vaccine candidates to prevent bacterial infections. The development and exploitation of such antibacterial strategies will depend on the discovery of other prophage-derived, virulence control mechanisms and, more generally, on the dissection of the mutualistic relationship between temperate phages and bacteria, as well as on continuing developments in the synthetic biology field.
Incentives or restrictions: policy choices in farmers’ chemical fertilizer reduction and substitution behaviors
Authors: Yang Yurong , Li Zhaoliang , Zhang Yan
Published: September 2020

Based on 804 samples of farmers in Hubei Province, a typical major grain-producing area in China, this study empirically analyzed the effects of two different policy tools, i.e. economic incentives (subsidies) and order enforcements (regulatory restrictions), as well as the effects of their interaction, on farmers’ chemical fertilizer reduction and substitution behaviors. Samples were grouped according to the degree of concurrent employment to analyze the effects on different groups. The results show that (1) the influences of these policies on the behaviors were significantly positive; (2) after constructing the interactive variables of the policies, the influence of the order enforcement policy was no longer significant, but the influence of the interaction was significantly positive; (3) the low-degree concurrent employment farmers were more likely to be affected by the order enforcement policy, whereas the high-degree ones were more affected by the economic incentive policy; and (4) the behaviors of the low-degree ones were strongly affected by family management characteristics, whereas the high-degree ones were more affected by the farmers’ individual characteristics.
LC–QTOF-MS Presumptive Identification of Synthetic Cannabinoids without Reference Chromatographic Retention/Mass Spectral Information. II. Evaluation of a Computational Approach for Predicting and Identifying Unknown High-Resolution Product Ion Mass Spectra
Authors: Polettini Aldo E , Kutzler Johannes , Sauer Christoph , Guber Susanne , Schultis Wolfgang
Published: September 2020

Despite liquid chromatography–high-resolution tandem mass spectrometry (MS2) enables untargeted acquisition, data processing in toxicological screenings is almost invariably performed in targeted mode. We developed a computational approach based on open source chemometrics software that, starting from a suspected synthetic cannabinoid (SC) determined formula, searches for isomers in different new psychoactive substances web databases, predicts retention time (RT) and high-resolution MS2 spectrum, and compares them with the unknown providing a rank-ordered candidates list. R was applied on 105 SC measured data to develop and validate a multiple linear regression quantitative structure–activity relationship model predicting RT. Competitive Fragmentation Modeling for Metabolite Identification (CFM-ID) freeware was used to predict/compare spectra with Jaccard similarity index. Data-dependent acquisition was performed with an Agilent Infinity 1290 LC-6550 iFunnel Q-TOF MS with ZORBAX Eclipse-Plus C18 (100 × 2.1 mm2/1.8 µm) in water/acetonitrile/ammonium formate gradient. Ability of the combined RT/MS2 prediction to identify unknowns was evaluated on SC standards (with leave-one-out from the RT model) and on unexpected SC encountered in real cases. RT prediction reduced the number of isomers retrieved from a group of new psychoactive substances web databases to one-third (2,792 ± 3,358→845 ± 983) and differentiated between SC isomers when spectra were not selective (4F-MDMB-BUTINACA, 4F-MDMB-BUTINACA 2ʹ-indazole isomer) or unavailable (4CN-Cumyl-B7AICA, 4CN-Cumyl-BUTINACA). When comparing 30/40 eV measured spectra of 99 SC against RT-selected, CFM-ID predicted spectra of isomers, the right candidate ranked 1st on median and 4th on average; 54% and 88% of times the right match ranked 1st or within the first 5 matches, respectively. To our knowledge, this is the first case of extensive chemometrics application to toxicological screening. In most cases, presumptive identification (being based on computation, it requires further information for confirmation) of unexpected SC was achieved without reference measured information. This method is currently the closest possible to true unbiased/untargeted screening. The bottleneck of the method is the processing time required to predict mass spectra (ca. 30–35 s/compound using a 64-bit 2.50-GHz Intel® Core™ i5-7200U CPU). However, strategies can be implemented to reduce prediction processing time.
The Fact-Law Distinction: Strategic Factfinding and Lawmaking in a Judicial Hierarchy
Authors: Shahshahani Sepehr
Published: September 2020

A fundamental but understudied procedural institution of American law is that appellate courts defer more to trial courts’ findings of fact than to their conclusions of law. I formally model this procedural institution, showing how trial courts use factfinding to achieve their preferred outcome and how appellate courts craft rules in anticipation of trial courts’ strategic factfinding. Trial courts do not always report facts truthfully. Appellate courts do not commit to consistent rules, but consistent rules may emerge in equilibrium, creating a misleading appearance of judicial commitment to legal consistency. Preference divergence between trial and appellate courts has a nonmonotonic effect on factfinding. Fact deference can explain suboptimal rulemaking and reversals even when there is no uncertainty about the likelihood of review or the reviewing court’s ideal rule. The model is also useful in understanding why the institution of fact deference persists. Applications to policing and other domains are discussed. (JEL K40, K41, D02)
The disintegrating old open cluster Czernik 3
Authors: Sharma Saurabh , Ghosh Arpan , Ojha D K , Pandey R , Sinha T , Pandey A K , Ghosh S K , Panwar N , Pandey S B
Published: September 2020

We have performed a detailed analysis of the Czernik 3 (Cz3) open cluster by using deep near-infrared photometry taken with TIRCAM2 on the 3.6 m Devasthal optical telescope along with the recently available high-quality proper motion data from the Gaia DR2 and deep photometric data from Pan-STARRS1. The cluster has a highly elongated morphology with fractal distribution of stars. The core and cluster radii of the cluster are estimated as 0.5 and 1.2 pc, respectively. We have identified 45 stars as cluster members using the Gaia proper motion data. The distance and age of the cluster are found to be 3.5 ± 0.9 kpc and $0.9^{+0.3}_{-0.1}$ Gyr, respectively. The slope of the mass function `Γ′ in the cluster region, in the mass range ∼0.95 <M/M⊙ < 2.2, is found to be −1.01 ± 0.43. The cluster shows the signatures of mass segregation and is dynamically relaxed (dynamical age = 10 Myr). This along with its small size, big tidal radius, low density/large separation of stars, and elongated and distorted morphology indicates that the Cz3 is a loosely bound disintegrating cluster under the influence of external tidal interactions.