bluuebunny/crossref_metadata_2025 huggingface dataset:
Unidirectional plasmonic Bragg reflector based on longitudinally asymmetric nanostructures*
Authors: Chen Mingsong , Pan Lulu , Lu Yuanfu , Li Guangyuan
Published: July 2019

Plasmonic Bragg reflectors are essential components in plasmonic circuits. Here we propose a novel type of plasmonic Bragg reflector, which has very high reflectance for the right-side incidence and meanwhile has extremely large absorption for the left-side incidence. This device is composed of longitudinally asymmetric nanostructures in a metal–insulator–metal waveguide. In order to efficiently analyze, design, and optimize the reflection and transmission characteristics of the proposed device, we develop a semi-analytic coupled-mode model. Results show that the reflectance extinction ratio between plasmonic modes incident from the right-side and the left-side reaches 11 dB. We expect this device with such striking unidirectional reflection performance can be used as insulators in nanoplasmonic circuits.
Direct simulation Monte Carlo study of metal evaporation with collimator in e-beam physical vapor deposition
Authors: Lu Xiaoyong , Chai Junjie
Published: July 2019

The flow properties and substrate deposition rate profile, which are the important parameters in electron beam physical vapor deposition, are investigated computationally in this article. Collimators are used to achieve the desired vapor beam and deposition rate profile in some applications. This increases the difficulty measuring boundary conditions and the size of the liquid metal pool inside the collimators. It is accordingly hard to obtain accurate results from numerical calculations. In this article, two-dimensional direct simulation Monte Carlo (DSMC) codes are executed to quantify the influence of uncertainties of boundary conditions and pool sizes. Then, three-dimensional DSMC simulations are established to simulate cerium and neodymium evaporation with the collimator. Experimental and computational results of substrate deposition rate profile are in excellent agreement at various evaporation rates and substrate heights. The results show that the DSMC method can assist in metal evaporation with a collimator.
Measuring the flexibility matrix of an eagle’s flight feather and a method to estimate the stiffness distribution*
Authors: Tang Di , Zhu Hai , Yuan Wei , Fan Zhongyong , Lei Mingxia
Published: July 2019

Flight feathers stand out with extraordinary mechanical properties for flight because they are lightweight but stiff enough. Their elasticity has great effects on the aerodynamics, resulting in aeroelasticity. Our primary task is to figure out the stiffness distribution of the feather to study the aeroelastic effects. The feather shaft is simplified as a beam, and the flexibility matrix of an eagle flight feather is tested. A numerical method is proposed to estimate the stiffness distributions along the shaft length based on an optimal Broyden–Fletcher–Goldfarb–Shanno (BFGS) method with global convergence. An analysis of the compressive behavior of the shaft based on the beam model shows a good fit with experimental results. The stiffness distribution of the shaft is finally presented using a 5th order polynomial.
Formation of electron depletion layer and parallel electric field in the separatrix region of anti-parallel magnetic reconnection*
Authors: Li Zisheng , Wang Huanyu , Gao Xinliang
Published: July 2019

It is generally accepted that during collisionless magnetic reconnection, electrons flow toward the X line in the separatrix region, and then an electron depletion layer is formed. In this paper, with two-dimensional (2D) particle-in-cell (PIC) simulation, we investigate the characteristics of the separatrix region during magnetic reconnection. In addition to the electron depletion layer, we find that there still exists an electric field parallel to the magnetic field in the separatrix region. Because a reduced ion-to-electron mass ratio and light speed are usually used in PIC simulation models, we also change these parameters to analyze the characteristics of the separatrix region. It is found that the increase in the ion-to-electron mass ratio makes the electron depletion layer and the parallel electric field more obvious, while the influence of light speed is less pronounced.
Impact of proton-induced alteration of carrier lifetime on single-event transient in SiGe heterojunction bipolar transistor*
Authors: Wei Jia-Nan , He Chao-Hui , Li Pei , Li Yong-Hong , Guo Hong-Xia
Published: July 2019

This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the single-event transient (SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor (SiGe HBT). The ion-induced current transients and integrated charge collections under different proton fluences are obtained based on technology computer-aided design (TCAD) simulation. The results indicate that the impact of carrier lifetime alteration is determined by the dominating charge collection mechanism at the ion incident position and only the long-time diffusion process is affected. With a proton fluence of 5×1013 cm−2, almost no change is found in the transient feature, and the charge collection of events happened in the region enclosed by deep trench isolation (DTI), where prompt funneling collection is the dominating mechanism. Meanwhile, for the events happening outside DTI where diffusion dominates the collection process, the peak value and the duration of the ion-induced current transient both decrease with increasing proton fluence, leading to a great decrease in charge collection.
Isostructural phase transition-induced bulk modulus multiplication in dopant-stabilized ZrO2 solid solution*
Authors: Wang Min , Shen Wen-Shu , Li Xiao-Dong , Li Yan-Chun , Zhang Guo-Zhao , Liu Cai-Long , Zhao Lin , Lv Shu-Peng , Gao Chun-Xiao , Han Yong-Hao
Published: July 2019

The electrical transport properties and structures of Y2O3/ZrO2 solid solution have been studied under high pressure up to 23.2 GPa by means of in situ impedance spectroscopy and x-ray diffraction (XRD) measurements. In the impedance spectra, it can be found that the pressure-dependent resistance of Y2O3/ZrO2 presents two different change trends before and after 13.3 GPa, but the crystal symmetry still remains stable in the cubic structure revealed by the XRD measurement and Rietveld refinement. The pressure dependence of the lattice constant and unit cell volume shows that the Y2O3/ZrO2 solid solution undergoes an isostructural phase transition at 13.1 GPa, which is responsible for the abnormal change in resistance. By fitting the volume data with the Birch–Murnaghan equation of state, we found that the bulk modulus B
0 of the Y2O3/ZrO2 solid solution increases by 131.9% from 125.2 GPa to 290.3 GPa due to the pressure-induced isostructural phase transition.
Adsorption behavior of triphenylene on Ru(0001) investigated by scanning tunneling microscopy*
Authors: Jing Li-Wei , Song Jun-Jie , Zhang Yu-Xi , Chen Qiao-Yue , Huang Kai-Kai , Zhang Han-Jie , He Pi-Mo
Published: July 2019

As a representative of small aromatic molecules, triphenylene (TP) has markedly high carrier mobility and is an ideal precursor for building graphene nanostructures. We mainly investigated the adsorption behavior of TP molecules on Ru(0001) by using scanning tunneling microscopy (STM). In submonolayer regime, TP molecules are randomly dispersed on Ru(0001) and the TP overlayer can be thoroughly dehydrogenated and converted into graphene islands at 700 K. Due to weak interaction between TP molecules and graphene, the grooves formed among graphene islands have confinement effect on TP molecules. TP adopts a flat-lying adsorption mode and has two adsorption configurations with the 3-fold molecular axis aligned almost parallel or antiparallel to the

[
1

1

¯

00] direction of the substrate. At TP coverages of 0.6 monolayer (ML) and 0.8 ML, the orientational distributions of the two adsorption configurations are equal. At about 1.0 ML, we find the coexistence of locally ordered and disordered phases. The ordered phase includes two sets of different superstructures with the symmetries of

(

19

×

19

)
R
23.41
°

and p(4×4), respectively. The adsorption behavior of TP on Ru(0001) can be attributed to the delicate balance between molecule–substrate and molecule–molecule interactions.
Global phase diagram of a spin–orbit-coupled Kondo lattice model on the honeycomb lattice*
Authors: Li Xin , Yu Rong , Si Qimiao
Published: July 2019

Motivated by the growing interest in the novel quantum phases in materials with strong electron correlations and spin–orbit coupling, we study the interplay among the spin–orbit coupling, Kondo interaction, and magnetic frustration of a Kondo lattice model on a two-dimensional honeycomb lattice. We calculate the renormalized electronic structure and correlation functions at the saddle point based on a fermionic representation of the spin operators. We find a global phase diagram of the model at half-filling, which contains a variety of phases due to the competing interactions. In addition to a Kondo insulator, there is a topological insulator with valence bond solid correlations in the spin sector, and two antiferromagnetic phases. Due to the competition between the spin–orbit coupling and Kondo interaction, the direction of the magnetic moments in the antiferromagnetic phases can be either within or perpendicular to the lattice plane. The latter antiferromagnetic state is topologically nontrivial for moderate and strong spin–orbit couplings.
The n-type Si-based materials applied on the front surface of IBC-SHJ solar cells*
Authors: Bao Jianhui , Tao Ke , Lin Yiren , Jia Rui , Liu Aimin
Published: July 2019

Interdigitated back contact silicon hetero-junction (IBC-SHJ) solar cells exhibit excellent performance owing to the IBC and SHJ structures. The front surface field (FSF) layer composed of electric field passivation and chemical passivation has been proved to play an important role in IBC-SHJ solar cells. The electric field passivated layer n+-a-Si: H, an n-type Si alloy with carbon or oxygen in amorphous phase, is simulated in this study to investigate its effect on IBC-SHJ. It is indicated that the n+-a-Si: H layer with wider band gap can reduce the light absorption on the front side efficaciously, which hinders the surface recombination of photo-generated carriers and thus contributes to the improvement of the short circuit current density J
sc. The highly doped n+-a-Si: H can result in the remakable energy band bending, which makes it outstanding in the field passivation, while it makes little contribution to the chemical passivation. It is noteworthy that when the electric field intensity exceeds 1.3 × 105 V/cm, the efficiency decrease caused by the inferior chemical passivation is only 0.16%. In this study, the IBC-SHJ solar cell with a front n+-a-Si: H field passivation layer is simulated, which shows the high efficiency of 26% in spite of the inferior chemical passivation on the front surface.
An overview of progress in Mg-based hydrogen storage films*
Authors: Jinzhe Lyu , M Lider Andrey , N Kudiiarov Viktor
Published: July 2019

Mg-based hydrogen storage materials are considered to be one of the most promising solid-state hydrogen storage materials due to their large hydrogen storage capacity and low cost. However, slow hydrogen absorption/desorption rate and excessive hydrogen absorption/desorption temperature limit the application of Mg-based hydrogen storage materials. The present paper reviews the advances in the research of Mg-based hydrogen storage film in recent years, including the advantage of the film, the function theory of fabricating method and its functional theory, and the influencing factors in the technological process. The research status worldwide is introduced in detail. By comparing pure Mg, Pd-caped Mg, non-palladium capped Mg, and Mg alloy hydrogen storage films, an ideal tendency for producing Mg-based film is pointed out, for example, looking for a cheap metal element to replace the high-priced Pd, compositing Mg film with other hydrogen storage alloy of catalytic elements, and so on.
Passively Q-switched diode-pumped Tm, Ho:LuVO4 laser with a black phosphorus saturable absorber*
Authors: Li Linjun , Li Tianxin , Zhou Long , Fan Jianying , Yang Yuqiang , Xie Wenqiang , Li Shasha
Published: July 2019

We presented a passively Q-switched (PQS) diode-pumped c-cut Tm, Ho:LuVO4 laser with a black phosphorus saturable absorber for the first time. Under PQS mode, an average output power of 0.86 W and a peak power of 2.32 W were acquired from the Tm, Ho:LuVO4 laser with the pump power of 14.55 W, corresponding to a pulse width of

2.89

μ
s

, a pulse repetition rate of 71.84 kHz, and a pulse energy of about

6.70

μ
J

.
Coherent control of fragmentation of methyl iodide by shaped femtosecond pulse train*
Authors: Tong Qiu-Nan , Fei De-Hou , Lian Zhen-Zhong , Qi Hong-Xia , Zhou Sheng-Peng , Luo Si-Zuo , Chen Zhou , Hu Zhan
Published: July 2019

Coherent control of fragmentation of CH3I using shaped femtosecond pulse train is investigated. The dissociation processes can be modulated by changing the separation of the shaped pulse train, and the yield of I+ under the irradiation of the optimal pulse is significantly increased compared with that using the transform-limited pulse. We discuss the control mechanism of dissociation processes with coherent interference in time domain. A three-pulse control model is proposed to explain the counterintuitive experimental results.
Josephson effect in the strontium titanate/lanthanum aluminate junction*
Authors: Yang Xing , Chen Jie , Yu Yabin , Liu Quanhui
Published: July 2019

We report theoretical studies on the newly discovered novel Josephson effect and scanning tunneling spectroscopy (STS) at the interface of strontium titanate/lanthanum aluminate (STO/LAO). With a phenomenological boson–fermion model, the density of states is calculated and the results are consistent with the STS experiments. A typical calculation of Josephson effect is performed, and it is in qualitative agreement with the experiments. The calculations indicate that the gap states come from the pairing of quasi-particles with a finite total momentum and the Josephson current comes from the tunneling of quasi-particle pairs with zero momentum. The quasi-particles are Bogoliubov quasi-particles. Moreover, the fits using Kulikʼs formula imply that the Josephson junction at the STO/LAO interface has a point contact with the clean superconductor limit.
Full-scale 3D remote sensing of wake turbulence - a taster
Authors: Larsen G.C. , Pedersen A.T. , Hansen K.S. , Larsen T.J. , Courtney M. , Sjöholm M.
Published: July 2019

The aim of the present paper is to investigate the wake turbulence as based on advanced full-scale measurements which, for the first time, makes it possible directly to resolve all three turbulence components in the wake behind an operating wind turbine with high spatial- and temporal resolution. The experimental setup will be described, and analysis of selected runs will be presented with a focus on the expected inhomogeneity of this turbulence field. The analyses are performed in a meandering frame of reference, and in addition to afore mentioned wake turbulence field, the wake deficit field will be resolved and analysed. Atmospheric stability is not considered but is, however, not expected to contribute noticeably to wake turbulence nor to the wake deficit field when expressed in the meandering frame of reference.
Wakes and wake interaction between rotors and discs in an experimental model array
Authors: Okulov V L , Kabardin I K , Litvinov I V , Mikkelsen R F , Naumov I V , Sørensen J N
Published: July 2019

The aim of the present paper is to obtain a better understanding of wakes generated by 2, 3 and 4 elements (disks and/or rotors) modeling an array of wind turbines in a wind farm. We here extend the results from our previous experimental model studies on the correlation between the behavior of the wake behind dual configurations of passive disks and active rotors to establish new knowledge regarding the wake development behind the 3rd and 4th rotor operating in a wake. To accomplish this, 2D PIV velocity measurements were carried out to investigate the flow properties upstream and downstream the tested rotors and discs in the array. The study also provides measured values of power and thrust coefficients of the model turbines using strain gauges installed directly on the rotors. The aim of the laboratory experiment is to provide data to calibrate and validate wake models for design and analysis arrays of wind turbines located in wind farms.
Investigating the impact of wakes on single turbine availability
Authors: Roscher B. , Redder F. , Schelenz R. , Jacobs G.
Published: July 2019

The current trend in wind energy leads to closely packed wind farms. These short distances result in a higher turbulence and consequently higher loads. In this paper an approach is proposed to evaluate single turbine availability losses due to the wake effect by modeling material fatigue behavior of selected turbine components. First, a characteristic wake scenario is defined: While one turbine is exposed to a wind field conforming to wind class IIB, another turbine experiences higher turbulence intensities according to Frandsen’s wake model. Using a dynamic multibody simulation, turbine loads are calculated which then are analyzed using the rainflow counting algorithm (giving load range and cycle counts) before being extrapolated to design lifetime of 20 years. Subsequently, artificial material curves are estimated representing the minimum load cycles to withstand during design lifetime. The slope of these curves is determined using the slope of a representative S-N-curve for each component. Position is then determined applying Miner’s rule with unity damage at the end of design lifetime. Lastly, failure behavior is approached by using a lognormal probability distribution. As a result increased failure probabilities for the rotor hub unit (main bearing and rotor hub) are found in the wake case. First results for an annual time in wake fraction of 20 % show an increase in total failure probability from 2.30 % to up to 41.85 % at a distance between the two turbines of 3D. Applying a mean down time per failure from literature (based on modern EU wind farms) finally leads to an overall technical availability decrease due to hub unit failure of 0. 035 % in the wake case compared to the free stream case.
Tip-vortex instabilities of two in-line wind turbines
Authors: Kleine V G , Kleusberg E , Hanifi A , Henningson D S
Published: July 2019

The hydrodynamic stability of a vortex system behind two in-line wind turbines operating at low tip-speed ratios is investigated using the actuator-line method in conjunction with the spectral-element flow solver Nek5000. To this end, a simplified setup with two identical wind turbine geometries rotating at the same tip-speed ratio is simulated and compared with a single turbine wake. Using the rotating frame of reference, a steady solution is obtained, which serves as a base state to study the growth mechanisms of induced perturbations to the system. It is shown that, already in the steady state, the tip vortices of the two turbines interact with each other, exhibiting the so-called overtaking phenomenon. Hereby, the tip vortices of the upstream turbine overtake those of the downstream turbine repeatedly. By applying targeted harmonic excitations at the upstream turbine’s blade tips a variety of modes are excited and grow with downstream distance. Dynamic mode decomposition of this perturbed flow field showed that the unstable out-of-phase mode is dominant, both with and without the presence of the second turbine. The perturbations of the upstream turbine’s helical vortex system led to the destabilization of the tip vortices shed by the downstream turbine. Two distinct mechanisms were observed: for certain frequencies the downstream turbine’s vortices oscillate in phase with the vortex system of the upstream turbine while for other frequencies a clear out-of-phase behaviour is observed. Further, short-wave instabilities were shown to grow in the numerical simulations, similar to existing experimental studies [1].
Large eddy simulations of floating offshore wind turbine wakes with coupled platform motion
Authors: Johlas H M , Martí­nez-Tossas L A , Schmidt D P , Lackner M A , Churchfield M J
Published: July 2019

The growing prospect for large farms of floating offshore wind turbines requires a better understanding of wake effects for floating turbines, particularly the differences when compared to fixed-bottom turbine wakes. The increased range of motion of floating platforms can influence wake characteristics, affecting downstream turbines. In this work, large eddy simulations with an actuator line model are used to study downstream wake characteristics of the NREL 5 MW reference turbine mounted on the OC3-UMaine spar platform for several different metocean conditions. The simulations are carried out in the Simulator fOr Wind Farm Applications (SOWFA) coupled with OpenFAST for the platform and turbine motion. The downstream wake characteristics of the floating platform are compared to equivalent fixed-bottom cases for different wind speeds, wave heights, wind-wave alignments, and turbine yaw angles. Overall, the differences in wake shape between floating and fixed platforms are associated with mean platform displacements, while differences in turbulence are associated with time-varying platform motion. However, these observed wake differences between fixed and floating platforms are small, especially for higher wind speeds and lower wave heights.
The wake of an actuator line with a vortex-based tip/smearing correction in uniform and turbulent inflow
Authors: Meyer Forsting Alexander R , Pirrung Georg R. , Ramos-García Néstor
Published: July 2019

The force smearing in the actuator line technique ensures its numerical stability, but also breaks its intended similarity to the lifting line by similarly smearing its vorticity in the flow domain. The wake thus induces lower velocities at the blade, linking the blade forces to the force smearing. A recently developed tuning-free, vortex-based correction recovers this missing induction, regaining the lifting-line behaviour of the actuator line. The interplay of this new smearing correction with grid and blade resolution is studied in uniform and turbulent inflow with respect to the blade forces and wake behaviour. With only 10 grid cells along the blade, the thrust is within 2.8% and the power within 5.7% of the high-resolution reference. With 20 grid cells the difference drops to 1.5% and 2.5%, respectively. The influence of the force smearing on the wake velocities dominates over the choice of correction, yet under turbulent inflow the wake characteristics become nearly independent of force smearing 6 rotor radii downstream of the turbine.
Optimal open loop wind farm control
Authors: Vitulli J.A. , Larsen G.C. , Pedersen M.M. , Ott S. , Friis-Møller M.
Published: July 2019

This paper presents a general purpose platform for optimal open loop control of wind power plants as seen from a power production perspective. The general idea is to change the controller design criteria from greedy individual wind turbines to a controller design facilitating cooperative and interdependent elements of a wind power plant, with the overall aim to improve the wind power plant power production conditioned on ambient mean wind speed and mean wind direction.

The flow within the wind power plant, including all essential interactions between the wind turbines, is modelled using a very fast linearized CFD RANS solver. The wind turbines are modelled as actuator discs, and two design variables per wind turbine – collective pitch, α, and tip speed ratio, λ – are initially defined for the optimization problem. However, a priory we expect one design variable to suffice – i.e. the unique set of (α, λ) representing the lowest thrust coefficient, CT
, for a given power coefficient Cp
. The conjectured collapse of the design space is justified in this paper.

Optimized control schemes for the Lillgrund offshore wind farm are derived conditioned on ambient mean wind direction and wind speed. Aggregated over a year, using the site sector Weibull distributions, an increase in the annual energy production of 1% is demonstrated.
NAM 2019: stars align in Lancaster
Authors: Bowler Sue
Published: July 2019

Lancaster University played host to a very successful National Astronomy Meeting at the start of July. Sue Bowler reports on both the conference and the news from NAM 2019.
Embedding our sciences in the National Eisteddfod
Authors: Tsiakaliari Eleni
Published: July 2019

Eleni Tsiakaliari takes a look at what the RAS 200 outreach project embedding science in to Welsh culture has achieved at the National Eisteddfod.
The founding of the RAS: E Troughton and G Dollond
Authors: Edmunds Michael
Published: July 2019

Mike Edmunds continues his survey of the origins of the RAS, with two renowned instrument-makers who were stalwarts of the Society through its early years.
Uncovering hidden treasures at the RAS
Authors: Prosser Siân
Published: July 2019

Librarian Siân Prosser selects highlights from some lesser-known and long-hidden parts of the RAS collections.
The Centre d'Accueil Nord-Africain: social welfare and the ‘problem' of Muslim youth in Marseille, 1950–1975
Authors: Harris Dustin Alan
Published: July 2019

In recent years, historians have paid increasing attention to social welfare initiatives undertaken in post-Second World War France to integrate Muslim Algerian migrants into French society and the legacies of these initiatives after decolonization. This article engages with this field of research by focusing on a topic it has largely ignored—the so-called ‘problem' of the integration of Muslim youth. The central point of focus is the Centre d'Accueil Nord-Africain (CANA), a private welfare association founded in Marseille in 1950 that well into the mid-1970s considered the integration of male Muslim North African youth its central objective. In exploring the origins and operations of the CANA over a roughly twenty-five-year period, this article offers new insights into issues of continuity and change related to the target, approach and objectives of integrationist social welfare for Muslim North Africans in France before and after decolonization.
The effects of a temporary lysine restriction in newly weaned pigs on growth performance and body composition1
Authors: Totafurno Adam D , Huber Lee-Anne , Mansilla Wilfredo D , Wey Douglas , Mandell Ira B , De Lange Cornelis F M
Published: July 2019

A serial slaughter study was conducted to determine the effects of a temporary Lys restriction immediately following weaning on growth performance and body composition. One hundred forty-four Yorkshire × Landrace × Duroc pigs (initial BW: 6.9 ± 0.2 kg) were randomly allocated to one of three dietary treatments (six pens per treatment with eight pigs per pen; four barrows and four gilts). For a 3-wk restriction period, pigs were fed diets that were 110% (Control) of the estimated required standardized ileal digestible (SID) Lys for nursery pigs or 20% (Lys20) or 40% (Lys40) below the estimated required SID Lys. Thereafter, all pigs were fed a common grower diet containing 120% of the estimated required SID Lys for 6 wk (recovery period). During the restriction period, ADG and G:F decreased with decreasing dietary Lys concentration (linear; P < 0.01). At the end of the restriction period, BW and whole-body protein concentrations decreased (linear; P < 0.01) and carcass lipid concentrations increased (linear; P < 0.01) with decreasing dietary Lys concentration. During the first 3 wk of the recovery period, ADG and G:F increased (linear; P < 0.05 and P < 0.01, respectively) and whole-body protein concentration at week 3 of the recovery period decreased (linear; P < 0.01) with decreasing dietary Lys concentration. There were no dietary treatment differences in whole-body lipid concentration after 3 wk of the recovery period. During the second half of the recovery period (weeks 7 through 9), there were no differences in ADG or G:F; after week 6, there were no differences in final BW (50.3 ± 0.5 kg) or whole-body protein (16.9 ± 0.2%) or lipid (14.9 ± 0.7%) concentrations. In conclusion, newly weaned pigs previously fed a Lys-limiting diet for 3 wk immediately after weaning achieved full compensatory growth with no differences in BW or body composition after a 6-wk recovery period. Reducing dietary Lys concentration early after weaning is a potential means to reduce the cost of (early) nursery diets without impacting overall growth and carcass composition.
Phylogenetic position of Alternochelata lizardensis Kornicker, 1982 within Rutidermatidae (Ostracoda: Myodocopida), with an investigation into its green coloration
Authors: Peniston James H , Ellis Emily A , Churchill Celia K C , Ramirez M Desmond , Oakley Todd H
Published: July 2019

We collected the ostracod Alternochelata lizardensis Kornicker 1982 via sediment sampling and evening plankton tows at Lizard Island, Queensland, Australia. While only previously described from samples that lost their natural color, we report males of the species to have bright green bundles of pigment throughout the inner carapace membrane and at specific locations on the ostracod’s body and an unusually colorless and translucent carapace. Females have a heavier carapace and some green pigmentation. We found, in a morphological phylogenetic analysis of Rutidermatidae, that A. lizardensis is part of a paraphyletic grade with other species of Alternochelata Kornicker, 1958 and Scleraner Kornicker, 1975. The analysis also supports a monophyletic Rutiderma Brady & Norman, 1896. We also explored with microscopic and bioinformatic techniques the nature of the unusual green coloration of A. lizardensis and tested the hypothesis that it harbors photosynthetic symbionts. We first sequenced RNA extracted from the entire body of females and searched for genetic markers of possible photobionts. We found genetic matches for two species of cyanobacteria commonly found in seawater. Using fluorescent confocal microscopy to search for chlorophyll autofluorescence in the green patches, we nevertheless found no evidence for the presence of chlorophyll. From these analyses, we concluded there is no evidence that A. lizardensis harbors photosynthetic symbionts suggesting the green coloration is due to something besides photosynthetic symbionts. The framework we present here is nevertheless applicable for other taxa where photobionts are suspected.
Trade and Women—Opportunities for Women in the Framework of the World Trade Organization
Authors: Acharya Rohini , Falgueras Alamo Olga , Al-Battashi Salma Mohamed Thabit , der Boghossian Anoush , Ghei Naghm , Parcero Herrera Tania , Jackson Lee Ann , Kask Ulla , Locatelli Claudia , Marceau Gabrielle , Motoc Ioana-Virginia , Müller Anna Caroline , Neufeld Nora , Padilla Simon , Pardo de Léon Josefita , Perantakou Stella , Sporysheva Nadezhda , Wolff Christiane
Published: July 2019

Empowering women is a significant step on the road towards achieving sustainable development, one the of the World Trade Organization’s (WTO) main goals. Today, 124 WTO Members and Observers (representing more than 75% of world trade and two-thirds of the WTO membership) support the Buenos Aires Declaration on Trade and Women’s Economic Empowerment endorsed in the margins of the 11th WTO Ministerial Conference, which seeks to remove trade barriers women face and foster their economic empowerment. This Declaration has made the WTO a key contributor, and even a leader, on the issue of women’s empowerment, in support of development and the 2030 Sustainable Development Goals. At the same time, it is important to note that inclusive trade is, and always has been, at the heart of the WTO’s work.

The paper therefore offers a preliminary analysis of the various areas of the WTO where women considerations can be used to contribute to building a more inclusive trade system, whether through the numerous provisions of the WTO covered agreements or within the ‘policy space’ that currently exists in the WTO framework. By lowering trade barriers, the WTO can help everyone to participate. Supporting the integration of women into international trade is fundamental to ensuring that everyone can reap the benefits of global trade.
The activation of the chymotrypsin-like activity of the proteasome is regulated by soluble adenyl cyclase/cAMP/protein kinase A pathway and required for human sperm capacitation
Authors: Zapata-Carmona Héctor , Barón Lina , Zuñiga Lidia M , Díaz Emilce Silvina , Kong Milene , Drobnis Erma Z , Sutovsky Peter , Morales Patricio
Published: July 2019

One of the first events of mammalian sperm capacitation is the activation of the soluble adenyl cyclase/cAMP/protein kinase A (SACY/cAMP/PKA) pathway. Here, we evaluated whether the increase in PKA activity at the onset of human sperm capacitation is responsible for the activation of the sperm proteasome and whether this activation is required for capacitation progress. Viable human sperm were incubated with inhibitors of the SACY/cAMP/PKA pathway. The chymotrypsin-like activity of the sperm proteasome was evaluated using a fluorogenic substrate. Sperm capacitation status was evaluated using the chlortetracycline assay and tyrosine phosphorylation. To determine whether proteasomal subunits were phosphorylated by PKA, the proteasome was immunoprecipitated and tested on a western blot using an antibody against phosphorylated PKA substrates. Immunofluorescence microscopy analysis and co-immunoprecipitation (IPP) were used to investigate an association between the catalytic subunit alpha of PKA (PKA-Cα) and the proteasome. The chymotrypsin-like activity of the sperm proteasome significantly increased after 5 min of capacitation (P < 0.001) and remained high for the remaining incubation time. Treatment with H89, KT5720 or KH7 significantly decreased the chymotrypsin-like activity of the proteasome (P < 0.001). IPP experiments indicated that PKA inhibition significantly modified phosphorylation of proteasome subunits. In addition, PKA-Cα colocalized with the proteasome in the equatorial segment and in the connecting piece, and co-immunoprecipitated with the proteasome. This is the first demonstration of sperm proteasome activity being directly regulated by SACY/PKA-Cα. This novel discovery extends our current knowledge of sperm physiology and may be used to manage sperm capacitation during assisted reproductive technology procedures.
My business is your business: the Court of Appeal’s decision in MN v OP
Authors: Fletcher Thomas
Published: July 2019

This article considers the decision of the Court of Appeal in England in MN v OP [2019] EWCA Civ 679 on the circumstances in which an anonymity order will be made in connection with an application under the Variation of Trusts Act 1958. It looks at the legal framework for the decision, in particular the basis for the contention that an analogy should be drawn with proceedings under Rule 21.10 of the Civil Procedure Rules, with the result that anonymity orders should be the norm. It then sets out the conclusion and reasoning of the Court of Appeal and provides some commentary on the possible ramifications of the decision for practitioners in England and other jurisdictions.
Draft Genome Sequence Resources of Three Strains (TOS4, TOS5, and TOS14) of Xylella fastidiosa Infecting Different Host Plants in the Newly Discovered Outbreak in Tuscany, Italy
Authors: Giampetruzzi Annalisa , D’Attoma Giusy , Zicca Stefania , Abou Kubaa Raied , Rizzo Domenico , Boscia Donato , Saldarelli Pasquale , Saponari Maria
Published: July 2019

An outbreak of Xylella fastidiosa was discovered in late 2018 in northern Italy affecting several plant species. Multilocus sequence typing analyses detected the presence of strains clustering in X. fastidiosa subsp. multiplex and harboring a hitherto uncharacterized sequence type, ST87. Three cultured strains (TOS4, TOS5, and TOS14) were subjected to high-throughput sequencing and the draft genomes assembled. Phylogenetic analysis conclusively indicated that they belong to the subspecies multiplex. The genetic information generated for these newly discovered strains further supports the evidence that sequence types are associated with the emergence of X. fastidiosa in Europe, posing major challenges for predicting the main threatened European and Mediterranean crops and plant species.
Mycoplasma genitalium: A Review
Authors: Gnanadurai Roshina , Fifer Helen
Published: July 2019

Mycoplasma genitalium

is a fastidious organism of the class Mollicutes, the smallest prokaryote capable of independent replication. First isolated in 1981, much is still unknown regarding its natural history in untreated infection. It is recognized as a sexually transmitted pathogen causing acute and chronic non-gonococcal urethritis (NGU) in men, with a growing body of evidence to suggest it also causes cervicitis and pelvic inflammatory disease in women. Its role in several other clinical syndromes is uncertain. The majority of people infected remain asymptomatic and clear infection without developing disease; asymptomatic screening is therefore not recommended. Prevalence rates are higher in patients attending sexual health clinics and in men with NGU. Limited availability of diagnostics has encouraged syndromic management, resulting in widespread antimicrobial resistance and given that few antimicrobial classes have activity against

M. genitalium

, there is significant concern regarding the emergence of untreatable strains. There is a need for wider availability of testing, which should include detection of macrolide resistance mediating mutations. Expertise in interpretation of microbiological results with clinical correlation ensures targeted treatment avoiding unnecessary antibiotic exposure. Public health surveillance nationally and internationally is vital in monitoring and responding to changing epidemiology trends. In this review, we summarize current knowledge of

M. genitalium

, including epidemiology, clinical and microbiological data, and discuss treatment challenges in the era of rising multidrug resistance.
Cardiac nitric oxide synthase 1 worsens heart failure with preserved ejection fraction through S-nitrosylation of histone deacetylase 2
Authors: Yoon Somy , Kim Mira , Lee Hangyeol , Kang Gaeun , Nam Kwang-Il , Kook Hyun , Eom Gwang Hyeon
Published: July 2019

Although the clinical importance of heart failure with preserved ejection fraction (HFpEF), which makes up half of heart failure, has been extensively explored, most therapeutic regimens, including nitric oxide (NO) donors, lack therapeutic benefit1-12. Here we report that neuronal nitric oxide synthase (nNOS, also known as NOS1) induces HFpEF by S-nitrosylation of histone deacetylase 2 (HDAC2). HFpEF animal models—SAUNA (SAlty drinking water/Unilateral Nephrectomy/Aldosterone)13,14 and mild transverse aortic constriction (TAC) mice14,15—showed increased nNOS expression and NO production, which resulted in the S-nitrosylation of HDAC2. HFpEF was alleviated in S-nitrosylation-dead HDAC2 knock-in mice. Pharmacologic intervention by either nNOS inhibition or HDAC2 denitrosylation attenuated HFpEF. Our observations are the first to demonstrate a completely new mechanistic aspect in HFpEF, which may provide a novel therapeutic approach to HFpEF. In addition, our results provide evidence for why conventional NO-enhancement trials have not been effective for improving HFpEF.
Auditory Activity is Diverse and Widespread Throughout the Central Brain ofDrosophila
Authors: Pacheco Diego A , Thiberge Stephan Y , Pnevmatikakis Eftychios , Murthy Mala
Published: July 2019

Sensory pathways are typically studied by starting at receptor neurons and following postsynaptic neurons into the brain. However, this leads to a bias in analysis of activity towards the earliest layers of processing. Here, we present new methods for volumetric neural imaging with precise across-brain registration, to characterize auditory activity throughout the entire central brain ofDrosophilaand make comparisons across trials, individuals, and sexes. We discover that auditory activity is present in most central brain regions and in neurons known to carry responses to other modalities. Auditory responses are temporally diverse, but the majority of activity, regardless of brain region, is tuned to aspects of courtship song. We find that auditory responses are stereotyped across trials and animals in early mechanosensory regions, becoming more variable at higher layers of the putative pathway, and that this variability is largely independent of spontaneous movements. This study highlights the power of using an unbiased, brain-wide approach for mapping the functional organization of sensory activity.
A catalog of cis-regulatory mutations in 12 major cancer types
Authors: Cheng Zhongshan , Vermeulen Michael , Rollins-Green Micheal , DeVeale Brian , Babak Tomas
Published: July 2019

Despite the recent availability of complete genome sequences of tumors from thousands of patients, isolating disease-causing (driver) non-coding mutations from the plethora of somatic variants is notoriously challenging, and only a handful of validated examples exist. By integrating whole-genome sequencing, gene expression, chromatin accessibility, and genetic data from TCGA, we identified 301 non-coding somatic mutations that affect gene expression in cis. These mutations cluster into 36 hotspot regions with diverse molecular mechanisms of gene expression regulation. We further show that these mutations have hallmark features of noncoding drivers; namely, that they confer a positive selection on growth, functionally disrupt transcription factor binding sites, and contribute to disease progression reflected in decreased overall patient survival.
Molecular Insights on exquisitely Selective SrtA inhibitors towards active site loop forming open/close lid conformations in SrtA from Bacillus anthracis
Authors: Selvaraj Chandrabose , Selvaraj Gurudeeban , Kaliamurthi Satyavani , Wei Dong-Qing , Singh Sanjeev Kumar
Published: July 2019

The present study clearly explains the dependency of inhibitory activities in SrtA inhibitors is closely related to protein conformational changes of SrtA from Bacillus anthracis B. anthracisSortase A (SrtA) protein anchors proteins by recognizing a cell wall sorting signal containing the amino acid sequence LPXTG In order to analyze conformational changes and the role of SrtA enzyme, especially the loop motions which situated proximal to the active site molecular dynamic simulation was carried out for 100ns. Particular loop is examined for its various conformations from the MD trajectories and the open/close lid conformations are considered for the enzyme activity validations. Experimentally verified SrtA inhibitors activity was analyzed through 3D-QSAR and Molecular docking approaches. Results indicate that, biological activity of SrtA inhibitors is closely related to the closed lid conformation of SrtA from Bacillus anthracis. This work may lead to a better understanding of the mechanism of action and aid to design a novel and more potent SrtA inhibitors.
Molecular correlates of topiramate andGRIK1rs2832407 genotype in pluripotent stem cell-derived neural cultures
Authors: Lieberman Richard , Jensen Kevin P. , Clinton Kaitlin , Levine Eric S. , Kranzler Henry R. , Covault Jonathan
Published: July 2019

There is growing evidence that the anticonvulsant topiramate is efficacious in reducing alcohol consumption. Further, an intronic single nucleotide polymorphism (rs2832407, C ➔ A) in theGRIK1gene, which encodes the GluK1 subunit of the excitatory kainate receptor, predicted topiramate’s effectiveness in reducing heavy drinking in a clinical trial. In the current study, we differentiated a total of 22 induced pluripotent stem cell (iPSCs) lines characterized byGRIK1rs2832407 genotype (10 A/A and 12 C/C) into forebrain-lineage neural cultures to explore molecular correlates ofGRIK1genotype that may relate to topiramate’s ability to reduce drinking. Our differentiation protocol yielded mixed neural cultures enriched for glutamatergic neurons. Characterization of theGRIK1locus revealed no effect of rs2832407 genotype onGRIK1isoform mRNA expression, however a significant difference was observed onGRIK1antisense-2, with higher expression in C/C neural cultures. Differential effects of acute exposure to 5 μM topiramate were observed on the frequency of spontaneous synaptic activity in A/A vs. C/C neurons, with a smaller reduction in excitatory event frequency and a greater reduction in inhibitory event frequency observed in C/C donor neurons. This work highlights the use of iPSC technologies to study pharmacogenetic treatment effects in psychiatric disorders and furthers our understanding of the molecular effects of topiramate exposure in human neural cells.
An in silico exploration of combining Interleukin-12 with Oxaliplatin to treat liver-metastatic colorectal cancer
Authors: Wang Qing , Wang Zhijun , Wu Yan , Klinke David J
Published: July 2019

Background

Combining anti-cancer therapies with orthogonal modes of action, such as direct cytotoxicity and immunostimulatory, hold promise for expanding clinical benefit to patients with metastatic disease. For instance, a chemotherapy agent Oxaliplatin (OXP) in combination with Interleukin-12 (IL-12) can eliminate pre-existing liver metastatic colorectal cancer and protect from relapse in a murine model. However, the underlying dynamics associated with the targeted biology and the combinatorial space consisting of possible dosage and timing of each therapy present challenges for optimizing treatment regimens. To address some of these challenges, we developed a predictive simulation platform for optimizing dose and timing of the combination therapy involving Mifepristone-induced IL-12 and chemotherapy agent OXP.

Methods

A multi-scale mathematical model comprised of impulsive ordinary differential equations was developed to describe the interaction between the immune system and tumor cells in response to the combined IL-12 and OXP therapy. An ensemble of model parameters were calibrated to published experimental data using a genetic algorithm and used represent three different phenotypes: responders, partial-responders, and non-responders.

Results

The multi-scale model captures tumor growth patterns of the three phenotypic responses observed in mice in response to the combination therapy against a tumor re-challenge and was used to explore changing the dose and timing of the mixed immune-chemotherapy on tumor growth subjected to a tumor re-challenge in mice. An increased ratio of CD8+ T effectors to regulatory T cells during and after treatment was key to improve tumor control in the responder cohort. Sensitivity analysis indicates that combined OXP and IL-12 therapy worked more efficiently in responders by increased priming of T cells, enhanced CD8+ T cell-mediated killing, and functional inhibition of regulatory T cells. In a virtual cohort that mimics non-responders and partial-responders, simulations show that an increased dose of OXP alone would improve the response. In addition, enhanced IL-12 expression alone or an increased number of treatment cycles of the mixed immune-chemotherapy can barely improve tumor control for non-responders and partial responders.

Conclusions

Overall, this study illustrates how mechanistic models can be used for in silico screening of the optimal therapeutic dose and timing in combined cancer treatment strategies.