bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational study of textured ferroelectric polycrystals: Texture development during templated grain growth
Authors: Zhou Jie E. , Yan Yongke , Priya Shashank , Wang Yu U.
Published: February 2017

Quantitative relationships between processing, microstructure, and properties in textured ferroelectric polycrystals and the underlying responsible mechanisms are investigated by phase field modeling and computer simulation. This study focuses on three important aspects of textured ferroelectric ceramics: (i) grain microstructure evolution during templated grain growth processing, (ii) crystallographic texture development as a function of volume fraction and seed size of the templates, and (iii) dielectric and piezoelectric properties of the obtained template-matrix composites of textured polycrystals. Findings on the first two aspects are presented here, while an accompanying paper of this work reports findings on the third aspect. In this paper, grain microstructure evolution in the polycrystalline matrix with different template volume fractions and seed sizes is simulated. To quantitatively characterize the crystallographic texture development during templated grain growth processing, a numerical algorithm is developed to compute the diffraction peak intensities and Lotgering factor of the simulated polycrystals during grain microstructure evolution. This novel approach provides a direct link between phase field simulation and diffraction experiment. This computational study clarifies the effects of the template volume fraction and template seed size on the final grain microstructure and texture. It is found that, while the degree of crystallographic texture generally increases with increasing template volume fraction, it is the average distance between template seeds that plays an important role. This finding suggests that reducing the template seed size and shortening the seed distance is an effective way to achieve higher texture at a lower template volume fraction, which is highly desired for enhancing the piezoelectric properties of ferroelectric polycrystals. The computational results are compared with complementary experiments, where good agreement is obtained.
Controlled electrochemical growth of ultra-long gold nanoribbons
Authors: Basnet Gobind , Panta Krishna R. , Thapa Prem S. , Flanders Bret N.
Published: February 2017

This paper describes the electrochemical growth of branchless gold nanoribbons with ∼40 nm × ∼300 nm cross sections and >100 μm lengths (giving length-to-thickness aspect ratios of >103). These structures are useful for opto-electronic studies and as nanoscale electrodes. The 0.75–1.0 V voltage amplitude range is optimal for branchless ribbon growth. Reduced amplitudes induce no growth, possibly due to reversible redox chemistry of gold at reduced amplitudes, whereas elevated amplitudes, or excess electrical noise, induce significant side-branching. The inter-relatedness of voltage-amplitude, noise, and side-branching in electrochemical nanoribbon growth is demonstrated.
Phase transitions in BaTiO3 under uniaxial compressive stress: Experiments and phenomenological analysis
Authors: Schader Florian H. , Khakpash Nasser , Rossetti George A. , Webber Kyle G.
Published: February 2017

The relative permittivity of polycrystalline BaTiO3 was measured from –150 °C to 250 °C at compressive bias stresses up to −500 MPa. Mechanical loading shifted the rhombohedral-orthorhombic, orthorhombic-tetragonal, and tetragonal-cubic phase transition temperatures and produced a pronounced broadening of the dielectric softening in the vicinity of all three transitions. The inter-ferroelectric rhombohedral-orthorhombic and orthorhombic-tetragonal phase transitions were found to be less stress sensitive than the ferroelectric-paraelectric transition occurring between tetragonal and cubic phases at the Curie point. The application of compressive stress resulted in a strong suppression of the relative permittivity, such that at the highest applied stress of −500 MPa, the permittivity in the single phase regions away from the phase transitions was found to display only a weak dependence on temperature between −100 °C and 125 °C. The experimental observations closely followed the predictions of a 2-4-6 Landau polynomial wherein the dielectric stiffness and higher-order dielectric stiffness coefficients are linear functions of uniaxial stress.
Effect of oblique channel on discharge characteristics of 200-W Hall thruster
Authors: Ding Yongjie , Peng Wuji , Sun Hezhi , Xu Yu , Wei Liqiu , Li Hong , Zeng Ming , Wang Fufeng , Yu Daren
Published: February 2017

In an experiment involving a 200-W Hall thruster, partial ionization occurs in the plume area because of the extrapolation of the magnetic field. To improve the thruster performance, the concept of an oblique channel is proposed for improving the ionization degree in the plume area. Calculations performed using a Particle-in-cell (PIC) simulator and the experimental results both show that an oblique channel structure can reduce the wall loss. Compared with a straight channel under similar conditions of the discharge voltage and current, the ionization degree in the plume area, thrust, specific impulse, propellant utilization, and anode efficiency are improved by ∼20%. The oblique channel is an important design consideration for improving the partial ionization of the plume area in the thruster.
Advanced polymer targets for TNSA regime producing 6 MeV protons at 1016 W/cm2 laser intensity
Authors: Torrisi L.
Published: February 2017

High intensity laser pulses, at an intensity of the order of 1016 W/cm2, are employed to irradiate in vacuum polyethylene terephthalate thin foils in the target normal sheath acceleration (TNSA) regime. The plasma obtained in the forward emission is investigated using ion collectors and semiconductor detectors connected in a time-of-flight configuration, Thomson parabola spectrometer, and X-ray streak camera. The results indicate that the foil thickness of 1 micron is optimal to accelerate protons of up to 6.5 MeV. The high ion acceleration can be due to different effects such as the high absorption in the advanced semicrystalline polymer containing spherulite centers, the high resonant absorption in gold nanoparticles embedded in the polymer, the optimal thickness of the used polymer to enhance the electron density in the forward plasma, and the self-focusing effect induced by preplasma created in front of the irradiated target.
In/GaN(0001)-(3×3)R30° adsorbate structure as a template for embedded (In, Ga)N/GaN monolayers and short-period superlattices
Authors: Chèze C. , Feix F. , Anikeeva M. , Schulz T. , Albrecht M. , Riechert H. , Brandt O. , Calarco R.
Published: February 2017

We explore an alternative way to fabricate (In, Ga)N/GaN short-period superlattices on GaN(0001) by plasma-assisted molecular beam epitaxy. We exploit the existence of an In adsorbate structure manifesting itself by a (3×3)R30° surface reconstruction observed in-situ by reflection high-energy electron diffraction. This In adlayer accommodates a maximum of 1/3 monolayer of In on the GaN surface and, under suitable conditions, can be embedded into GaN to form an In0.33Ga0.67N quantum sheet whose width is naturally limited to a single monolayer. Periodically inserting these quantum sheets, we synthesize (In,Ga)N/GaN short-period superlattices with abrupt interfaces and high periodicity as demonstrated by x-ray diffractometry and scanning transmission electron microscopy. The embedded quantum sheets are found to consist of single monolayers with an In content of 0.25–0.29. For a barrier thickness of 6 monolayers, the superlattice gives rise to a photoluminescence band at 3.16 eV, close to the theoretically predicted values for these structures.
Direct evidence of entropy driven fluid-like – glass-like transition in microgel suspensions
Authors: Guo Yun Xia , Liu Ying Dan , Liu Riping , Tian Yongjun , Chen Ke , Wang Li-Min
Published: February 2017

The phase transitions in poly (N-isopropylacrylamide) (PNIPAM) microgel suspensions are studied using rheological and calorimetric measurements at various concentrations. Two transitions are resolved, one being the hydrophilic-hydrophobic transition imposed by the gain/release of H2O molecules in PNIPAM particles via H-bond interactions, the other the fluid-like – glass-like transition of the hydrated microgels. The relaxation behaviors in the frozen glass-like states are observed by monitoring the shear modulus upon aging. Nevertheless, no enthalpic signature is detected in the relaxation process, suggesting entropy-driven relaxation dynamics.
Pyroelectric response in crystalline hafnium zirconium oxide (Hf1-xZrxO2) thin films
Authors: Smith S. W. , Kitahara A. R. , Rodriguez M. A. , Henry M. D. , Brumbach M. T. , Ihlefeld J. F.
Published: February 2017

Pyroelectric coefficients were measured for 20 nm thick crystalline hafnium zirconium oxide (Hf1-xZrxO2) thin films across a composition range of 0 ≤ x ≤ 1. Pyroelectric currents were collected near room temperature under zero applied bias and a sinusoidal oscillating temperature profile to separate the influence of non-pyroelectric currents. The pyroelectric coefficient was observed to correlate with zirconium content, increased orthorhombic/tetragonal phase content, and maximum polarization response. The largest measured absolute value was 48 μCm−2 K−1 for a composition with x = 0.64, while no pyroelectric response was measured for compositions which displayed no remanent polarization (x = 0, 0.91, and 1).
Energy consumption analysis of graphene based all spin logic device with voltage controlled magnetic anisotropy
Authors: Zhang Zhizhong , Zhang Yue , Zheng Zhenyi , Wang Guanda , Su Li , Zhang Youguang , Zhao Weisheng
Published: February 2017

All spin logic device (ASLD) is a promising option to realize the ultra-low power computing systems. However, the low spin transport efficiency and the non-local switching of the detector have become two key challenges of the ASLD. In this paper, we analyze the energy consumption of a graphene based ASLD with the ferromagnetic layer switching assistance by voltage control magnetic anisotropy (VCMA) effect. This structure has significant potential towards ultra-low power consumption: the applied voltage can not only shorten switching time of the ferromagnetic layer, but also decreases the critical injection current; the graphene channel enhances greatly the spin transport efficiency. By applying the approximate circuit model, the impact of material configurations, interfaces and geometry can be synthetically studied. An accurate physic model was also developed, based on which, we carry out the micro-magnetic simulations to analyze the magnetization dynamics. Combining these electrical and magnetic investigations, the energy consumption of the proposed ASLD can be estimated. With the optimizing parameters, the energy consumption can be reduced to 2.5 pJ for a logic operation.
Color and Kerr rotation in a dielectric/ferromagnetic double layers structure
Authors: Zhang Jing , Wang Hai , Qu Xin , Zhou Yunsong
Published: February 2017

By the multiple reflections and transmissions in a dielectric on a ferromagnetic metal, color and Kerr rotation correlate with each other. It is revealed that the real refractive index of dielectric plays a major role on the variations of color and Kerr signal, while the absorbing term adjusts the intensive color exhibition and Kerr enhancement at much thinner dielectric thickness. The intensive Kerr signal variation is always accompanied by the color transition with the dielectric thickness changing. Experimental results observed in silicon(or silica)/iron samples are well consistent with calculations. Nanometer dielectric optical coating can not only enhance Kerr effect but also endow magnetic surface with chromatics, which has promising potential applications in anti-fake brands, colorful decorations, camouflages, and even bionics.
Single crystalline silicon solar cells with rib structure
Authors: Yoshiba Shuhei , Hirai Masakazu , Abe Yusuke , Konagai Makoto , Ichikawa Yukimi
Published: February 2017

To improve the conversion efficiency of Si solar cells, we have developed a thin Si wafer-based solar cell that uses a rib structure. The open-circuit voltage of a solar cell is known to increase with deceasing wafer thickness if the cell is adequately passivated. However, it is not easy to handle very thin wafers because they are brittle and are subject to warpage. We fabricated a lattice-shaped rib structure on the rear side of a thin Si wafer to improve the wafer’s strength. A silicon nitride film was deposited on the Si wafer surface and patterned to form a mask to fabricate the lattice-shaped rib, and the wafer was then etched using KOH to reduce the thickness of the active area, except for the rib region. Using this structure in a Si heterojunction cell, we demonstrated that a high open-circuit voltage (VOC) could be obtained by thinning the wafer without sacrificing its strength. A wafer with thickness of 30 μm was prepared easily using this structure. We then fabricated Si heterojunction solar cells using these rib wafers, and measured their implied VOC as a function of wafer thickness. The measured values were compared with device simulation results, and we found that the measured VOC agrees well with the simulated results. To optimize the rib and cell design, we also performed device simulations using various wafer thicknesses and rib dimensions.
The influence of the edge effect on the skyrmion generation in a magnetic nanotrack
Authors: Ran N. , Zhao G. P. , Tang H. , Shen L. C. , Lai P. , Xia J. , Zhang X. , Zhou Y.
Published: February 2017

Magnetic skyrmions might be used for building next-generation nanomagnetic and spintronic devices, as they have several perspective properties, such as topologically protected stability, nanoscale size, and ultra-low depinning current density. Here we study the influence of the edge effect on the current-induced generation of a magnetic skyrmion in a finite-length thin-film ferromagnetic nanotrack with interface-induced Dzyaloshinskii-Moriya interaction. It shows that a stable skyrmion or a bunch of skyrmions can be successfully generated as long as the distance between the current injection region and the nanotrack terminal is larger than a certain threshold. We investigate the failed skyrmion generation caused by the edge effect, which will lead to an error writing event. We also present the phase diagrams of the skyrmion generation obtained for different material and geometric parameters. Our results could be useful for designing skyrmion-based information storage devices.
Observation of high T
c one dimensional superconductivity in 4 angstrom carbon nanotube arrays
Authors: Zhang Bing , Liu Yang , Chen Qihong , Lai Zhiping , Sheng Ping
Published: February 2017

The only known approach to fabricate large, uniform arrays of 4-Å single wall carbon nanotubes (SWNTs) is by using zeolite crystals as the template, in which the nanotubes are formed by chemical vapor deposition inside the linear channels of the AlPO4-5 (AFI for short) zeolite. However, up to now the pore filling factor has been very low, as evidenced by the weight percentage of carbon in thermal gravimetric analysis (TGA) measurements. In this work, we show that by using a new, micro-platelet AFI crystals as the template, combined with the use of a new CVD process, we can increase the TGA result to 22.5wt%, which translates to a pore filling factor of 91%. We have observed one dimensional (1D) superconductivity in such samples. The temperature dependence of resistance shows a smooth decreasing trend below 60 K, and the differential resistance displays a gap that disappears above the 1D superconducting initiation temperature. The observed behaviour is shown to agree very well with the theoretical predictions of 1D superconductivity.
Maternal body composition in seedstock herds. 2. Relationships between cow body composition and BREEDPLAN EBVs for Angus and Hereford cows
Authors: Lee S. J. , Donoghue K. A. , Pitchford W. S.
Published: February 2017

Relationships between BREEDPLAN estimated breeding values (EBVs) for 600-day weight, maternal effect on calf weaning weight (Milk), fat depth at P8 site (Rump), 12/13th rib fat depth (Rib), eye muscle area (EMA), and intramuscular fat (IMF) with body composition measures in first- and second-parity Angus and Hereford cows were investigated. More than 4000 Angus and 1000 Hereford cows were measured for weight, height, ultrasound P8 fat depth (P8), 12/13th rib fat depth (RIB), loin EMA and IMF (%) at pre-calving and weaning. The body composition measurements were then regressed against mid-parent BREEDPLAN EBVs. Increased 600-day weight EBV was associated with increased weight and height but decreased P8 and rib fat depths and EMA when considered on a weight-constant basis. BREEDPLAN EBVs for Rump, Rib, EMA and IMF were closely related to the equivalent ultrasound measure in Angus and Hereford cows at pre-calving and weaning in the first two parities. These results indicate that current BREEDPLAN carcass EBVs are associated with cow body composition, so if producers want to change the body composition of their cows, they can do so using existing BREEDPLAN carcass EBVs, and there appears no requirement for additional EBVs to describe cow body-composition traits for subcutaneous fat, EMA and IMF.
Polydatin improves the developmental competence of bovine embryos in vitro via induction of sirtuin 1 (Sirt1)
Authors: Khan Imran , Kim Sung Woo , Lee Kyung-Lim , Song Seok-Hwan , Mesalam Ayman , Chowdhury M. M. R. , Uddin Zia , Park Ki Hun , Kong Il-Keun
Published: February 2017

The aim of the present study was to investigate the beneficial effect of polydatin (PD), the glycoside form of resveratrol, on embryo development in vitro. Oocytes were aspirated from ovaries of Korean Hanwoo cows and cultured until Day 8 in a humidified atmosphere of 5% CO2 in air at 38.5°C. Protein and gene expression levels were determined through confocal microscopy and reverse transcription–polymerase chain reaction respectively, whereas the number of total and apoptotic cells in Day 8 blastocysts was determined using Hoechst 33342 staining and terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling. Of the different concentrations of PD (0.5, 1.0 and 2.0 µM) added to the IVM medium, only 1.0 µM PD significantly improved blastocyst development. Immunofluorescence analysis confirmed that protein levels of sirtuin 1 (Sirt1) increased significantly (P < 0.05) after PD treatment, whereas levels of reactive oxygen species (ROS) were significantly (P < 0.05) decreased, as evidenced by reductions in 8-oxoguanine immunoreactivity. Similarly, protein levels of nuclear factor (NF)-κB and cyclo-oxygenase (COX)-2  were significantly (P < 0.05) lower in the PD-treated group than in the control group. Treatment with 1.0 µM PD reduced gene expression of BCL2-associated X protein, inducible nitric oxide synthase, COX2 and Nfkb, but increased the expression of Sirt1, supporting the immunofluorescence data. PD possesses antioxidant activity and is useful for embryo development in vitro. We conclude that supplementation of IVM medium with PD improves embryo developmental competence via Sirt1.
Two types of amorphous protein particles facilitate crystal nucleation
Authors: Yamazaki Tomoya , Kimura Yuki , Vekilov Peter G. , Furukawa Erika , Shirai Manabu , Matsumoto Hiroaki , Van Driessche Alexander E. S. , Tsukamoto Katsuo
Published: February 2017

Significance

The formation of the nuclei of protein crystals has been suggested to occur within protein-rich mesoscopic clusters. The existence of such clusters has been revealed for many proteins; however, their role in crystallization is still unclear. Our live images in a protein crystallization solution using transmission electron microscopy reveal that protein-rich mesoscopic clusters are solid amorphous particles that work as heterogeneous nucleation sites. The nucleation event for the crystal starts via another noncrystalline particle, which appears only a few seconds before crystal nucleation, that is, there are two types of amorphous particles that have different roles in protein crystallization.
NFκB–Pim-1–Eomesodermin axis is critical for maintaining CD8 T-cell memory quality
Authors: Knudson Karin M. , Pritzl Curtis J. , Saxena Vikas , Altman Amnon , Daniels Mark A. , Teixeiro Emma
Published: February 2017

Significance

Mice and humans whose T cells are deficient in NFκB signaling lack memory T cells, but the mechanism behind this is unclear. We found that NFκB signaling is required during the resolution phase of the immune response to maintain long-term CD8 memory. NFκB signaling is necessary for preserving expression of Eomesodermin and prosurvival Bcl-2 in memory T cells, in a cell-intrinsic process where T-cell receptor (TCR) signals and Pim-1 kinase are involved. Our study defines an unexpected role of NFκB and Pim-1 signaling in the maintenance of T-cell memory quality. Furthermore, it identifies targets and specific times of intervention where protective T-cell memory could be reinforced in vaccines and cancer immunotherapies by manipulation of the NFκB–Pim-1–Eomesodermin axis.
The ETS-5 transcription factor regulates activity states in
Caenorhabditis elegans
by controlling satiety
Authors: Juozaityte Vaida , Pladevall-Morera David , Podolska Agnieszka , Nørgaard Steffen , Neumann Brent , Pocock Roger
Published: February 2017

Significance

Animals constantly monitor their internal energy levels and modify their eating and foraging behavior as required. Our work defines a role for the ETS-5 transcription factor in the control of body fat levels and thereby the activity of animals. We have defined the responses controlled by ETS-5 at the genetic, cellular, and organismal levels and identified how ETS-5 interacts with known pathways that regulate food-regulated behavioral states. These findings provide insight into how fat levels are regulated and how satiety controls organismal activity.
Dopamine in the medial amygdala network mediates human bonding
Authors: Atzil Shir , Touroutoglou Alexandra , Rudy Tali , Salcedo Stephanie , Feldman Ruth , Hooker Jacob M. , Dickerson Bradford C. , Catana Ciprian , Barrett Lisa Feldman
Published: February 2017

Significance

Early life bonding in humans has critical long-term implications for health, productivity, and well-being in society. Nonetheless, neural mechanisms of bonding are typically studied in rodents, and no studies to date had examined the neurochemistry of human social affiliation. This study utilizes a state-of-the-art technology to demonstrate that human maternal bonding is associated with striatal dopamine function and the recruitment of a cortico–striatal–amygdala brain network that supports affiliation. The simultaneous probing of neurochemical responses and whole-brain network function in mothers watching their infants provides a unique observation into an “affiliating brain.” These results advance the mechanistic understanding of human social bonding and promote basic and clinical research in social neuroscience, development, and psychopathology.
Structure of a lipid A phosphoethanolamine transferase suggests how conformational changes govern substrate binding
Authors: Anandan Anandhi , Evans Genevieve L. , Condic-Jurkic Karmen , O’Mara Megan L. , John Constance M. , Phillips Nancy J. , Jarvis Gary A. , Wills Siobhan S. , Stubbs Keith A. , Moraes Isabel , Kahler Charlene M. , Vrielink Alice
Published: February 2017

Significance

At this time, multidrug-resistant gram-negative bacteria are estimated to cause approximately 700,000 deaths per year globally, with a prediction that this figure could reach 10 million a year by 2050. Antivirulence therapy, in which virulence mechanisms of a pathogen are chemically inactivated, represents a promising approach to the development of treatment options. The family of lipid A phosphoethanolamine transferases in gram-negative bacteria confers bacterial resistance to innate immune defensins and colistin antibiotics. The development of inhibitors to block lipid A phosphoethanolamine transferase could improve innate immune clearance and extend the usefulness of colistin antibiotics. The solved crystal structure and biophysical studies suggest that the enzyme undergoes large conformational changes to enable binding and catalysis of two very differently sized substrates.
THADA
fusion is a mechanism of IGF2BP3 activation and IGF1R signaling in thyroid cancer
Authors: Panebianco Federica , Kelly Lindsey M. , Liu Pengyuan , Zhong Shan , Dacic Sanja , Wang Xiaosong , Singhi Aatur D. , Dhir Rajiv , Chiosea Simion I. , Kuan Shih-Fan , Bhargava Rohit , Dabbs David , Trivedi Sumita , Gandhi Manoj , Diaz Rachel , Wald Abigail I. , Carty Sally E. , Ferris Robert L. , Lee Adrian V. , Nikiforova Marina N. , Nikiforov Yuri E.
Published: February 2017

Significance

Thyroid cancer is the fastest-growing cancer type in the United States, yet its molecular mechanisms are not fully understood. Here we report the identification and characterization of a gene fusion involving the thyroid adenoma-associated (
THADA
) and
LOC389473
genes in papillary thyroid cancers, which leads to strong overexpression of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) and signaling via the IGF2/IGF1 receptor (IGF1R) pathway. As a result, we report a previously unknown structural mechanism responsible for IGF2BP3 overexpression in cancer. We also show that IGF2BP3 overexpression via different mechanisms can be found in 5 to 15% of several cancer types, and demonstrate that growth of these tumors can be blocked by IGF1R inhibitors. This raises the possibility that IGF2BP3 overexpression may be used to predict therapeutic response to IGF1R inhibition in cancer cells.
Vulnerability of primitive human placental trophoblast to Zika virus
Authors: Sheridan Megan A. , Yunusov Dinar , Balaraman Velmurugan , Alexenko Andrei P. , Yabe Shinichiro , Verjovski-Almeida Sergio , Schust Danny J. , Franz Alexander W. , Sadovsky Yoel , Ezashi Toshihiko , Roberts R. Michael
Published: February 2017

Significance

We have tested the hypothesis that the placenta of early pregnancy might be more easily breached by the Zika virus (ZIKV) than the relatively resistant outer cells of the mature placenta. Colonies of placental lineage cells derived from embryonic stem cells, which are probably analogous to the primitive placenta at implantation, were lysed more rapidly by an African strain of ZIKV, considered relatively benign, than by an Asian strain linked to fetal brain abnormalities. We conclude that the human fetus may be most vulnerable to ZIKV very early in pregnancy and that the African strain may threaten a pregnancy more strongly than previously believed.
Rules of RNA specificity of hnRNP A1 revealed by global and quantitative analysis of its affinity distribution
Authors: Jain Niyati , Lin Hsuan-Chun , Morgan Christopher E. , Harris Michael E. , Tolbert Blanton S.
Published: February 2017

Significance

Human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a key protein that functions in RNA metabolism both under normal and diseased cellular conditions. Despite playing a central role in eukaryotic biology, the mechanisms by which hnRNP A1 discriminates between cognate and noncognate RNA targets remain poorly understood. Here, we combined high-throughput sequencing analysis of equilibrium binding (HTS-EQ) experiments with independent biophysical measurements to reveal the complete hnRNP A1 specificity landscape. The data show that RNA sequence, motif copy number, spacing, and secondary structure determine specificity by modulating rates of productive hnRNP A1-RNA encounters. Thus, our work provides significant insights into the combinatorial factors that determine how hnRNP A1 identifies functional binding sites in vivo.
Regulatory cascade and biological activity of
Beauveria bassiana
oosporein that limits bacterial growth after host death
Authors: Fan Yanhua , Liu Xi , Keyhani Nemat O. , Tang Guirong , Pei Yan , Zhang Wenwen , Tong Sheng
Published: February 2017

Significance

Since the discovery of oosporein more than 70 years ago, there have been conflicting reports on its potential antimicrobial and insecticidal activities. Our results indicate that oosporein is unlikely to function as an insect toxin or to be involved in early to mid-infection processes, including penetration and immune evasion. Instead, oosporein most likely functions after death of the host to thwart bacterial competition on a host cadaver, allowing the fungus to maximally use host nutrients and complete its life cycle. Our data also reveal that oosporein production is regulated by a cascade of transcription factors, with BbSmr1 acting as an upstream negative regulator, targeting the expression of OpS3, which in turn acts as a positive regulator of the oosporein biosynthetic gene cluster.
Contribution of epigenetic mechanisms to variation in cancer risk among tissues
Authors: Klutstein Michael , Moss Joshua , Kaplan Tommy , Cedar Howard
Published: February 2017

Significance

It is well-known that the risk of cancer varies widely between different tissues of the body with some cell types (e.g., colon, breast) being prone to cancer, whereas others (e.g., brain, bone) only rarely develop tumors, but the mechanism of this phenomenon has not been elucidated. Recently, it was shown that this risk coefficient may actually be related to the inherent number of stem-cell divisions that go into generating each individual cell type during development. In this work, we demonstrate that cancer risk is highly correlated with the degree of aberrant age-dependent methylation in normal tissues, clearly supporting the idea that cell-type tumor susceptibility may be influenced by biologically intrinsic epigenetic factors.
Neuronal hyperexcitability in a mouse model of
SCN8A
epileptic encephalopathy
Authors: Lopez-Santiago Luis F. , Yuan Yukun , Wagnon Jacy L. , Hull Jacob M. , Frasier Chad R. , O’Malley Heather A. , Meisler Miriam H. , Isom Lori L.
Published: February 2017

Significance

Patients with early infantile epileptic encephalopathy experience severe seizures and cognitive impairment and are at increased risk for sudden unexpected death in epilepsy (SUDEP). Here, we investigated the neuronal phenotype of a mouse model of early infantile epileptic encephalopathy (EIEE) 13 caused by a mutation in the sodium channel gene
SCN8A
. We found that excitatory and inhibitory neurons from mutant mice had increased persistent sodium current density. Measurement of action potential firing in brain slices from mutant mice revealed hyperexcitability with spontaneous firing in a subset of neurons. These changes in neurons are predicted to contribute to the observed seizure phenotype in whole animals. Our results provide insights into the disease mechanism and future treatment of patients with EIEE13.
Multiple-scale neuroendocrine signals connect brain and pituitary hormone rhythms
Authors: Romanò Nicola , Guillou Anne , Hodson David J. , Martin Agnès O , Mollard Patrice
Published: February 2017

Significance

The hypothalamo–pituitary axis controls a wide range of homeostatic processes, including growth, stress, and reproduction. Despite this fact, the hypothalamic neuron firing patterns that lead to slowly evolving pituitary hormone rhythms remain enigmatic. Here, we used in vivo amperometric recordings in freely behaving mice to investigate how tuberoinfundibular neurons release dopamine (DA) at the median eminence (ME) to control pituitary prolactin secretion. Using this approach, we show that DA release occurs as multiple locally generated and time-scaled secretory events, which are integrated over a range of minutes across the ME. These results provide a broad physiological mechanism for the dialogue that occurs between the brain and pituitary to dictate hormone rhythms over multiple timescales, from ultradian to seasonal.
Ontogeny of collective behavior reveals a simple attraction rule
Authors: Hinz Robert C. , de Polavieja Gonzalo G.
Published: February 2017

Significance

Different interaction rules among animals can produce patterns of collective motion similar to those observed in bird flocks or fish schools. To help distinguish which rules are implemented in animal collectives, we studied the birth of the interaction rule in zebrafish during development from hatching to the juvenile stage. We used newly developed machine vision algorithms to track each animal in a group without mistakes. A weak attraction starts after hatching and gets stronger every day during development. Attraction consists in each larva moving toward one other larva chosen effectively at random and then switching to another one. This rule, simply by statistics, makes each individual move to regions of high density of individuals to produce collective motion.
Interleukin 37 reverses the metabolic cost of inflammation, increases oxidative respiration, and improves exercise tolerance
Authors: Cavalli Giulio , Justice Jamie N. , Boyle Kristen E. , D’Alessandro Angelo , Eisenmesser Elan Z. , Herrera Jonathan J. , Hansen Kirk C. , Nemkov Travis , Stienstra Rinke , Garlanda Cecilia , Mantovani Alberto , Seals Douglas R. , Dagna Lorenzo , Joosten Leo A. B. , Ballak Dov B. , Dinarello Charles A.
Published: February 2017

Significance

Interleukin 1 family member IL-37 is a naturally occurring inhibitor of inflammation. In this study, exogenous administration of recombinant human IL-37 reversed the decrease in exercise performance observed during systemic inflammation. IL-37 also increased exercise performance in healthy mice. IL-37 treatment acted through a dual mechanism of suppression of inflammation and modulation of metabolic pathways. The implications of the present findings impact on patients with chronic inflammatory diseases spanning from rheumatoid arthritis to cancer, in which fatigue is often incapacitating, and provide rationale for exploring recombinant IL-37 in the treatment of inflammation-mediated fatigue.
Exceedingly small iron oxide nanoparticles as positive MRI contrast agents
Authors: Wei He , Bruns Oliver T. , Kaul Michael G. , Hansen Eric C. , Barch Mariya , Wiśniowska Agata , Chen Ou , Chen Yue , Li Nan , Okada Satoshi , Cordero Jose M. , Heine Markus , Farrar Christian T. , Montana Daniel M. , Adam Gerhard , Ittrich Harald , Jasanoff Alan , Nielsen Peter , Bawendi Moungi G.
Published: February 2017

Significance

Gadolinium (Gd)-based contrast agents (GBCAs) are currently the mainstream clinical MRI contrast agents. Some GBCAs have shown a long-term toxicity—nephrogenic systemic fibrosis (NSF)—and Gd depositions in the brain. The NSF has triggered a Food and Drug Administration (FDA) black-box warning and a contraindication of some GBCAs. The finding of Gd depositions led to an ongoing FDA investigation to monitor their possible long-term adverse effects. Here, we present T
1
-weighted contrast-enhanced MR imaging and angiography using zwitterion-coated exceedingly small superparamagnetic iron oxide nanoparticles (ZES-SPIONs) in mice and rats. Renal clearance and biodistribution results further demonstrate that ZES-SPIONs are qualitatively different from previously reported SPIONs. This work may open up opportunities to develop exceedingly small SPIONs that show effective T
1
contrast as Gd-free alternatives to GBCAs.
Genetic signature of natural selection in first Americans
Authors: G. Amorim Carlos Eduardo , Nunes Kelly , Meyer Diogo , Comas David , Bortolini Maria Cátira , Salzano Francisco Mauro , Hünemeier Tábita
Published: February 2017

Significance

There is much interest in understanding the role of natural selection in shaping physiological adaptations to climate, diet, and diseases in humans. We investigated this issue by analyzing genomic data from Native American populations inhabiting different ecological regions and ancient Native Americans. We found signals of natural selection at the fatty acid desaturases (
FADS
) genes not only in an Arctic population, as was previously found, but throughout the Americas, suggesting a single and strong adaptive event that occurred in Beringia, before the range expansion of the first Americans within the American continent and Greenland.
Spontaneous expression of mirror self-recognition in monkeys after learning precise visual-proprioceptive association for mirror images
Authors: Chang Liangtang , Zhang Shikun , Poo Mu-ming , Gong Neng
Published: February 2017

Significance

Self-awareness is a higher intelligence that can be revealed by mirror self-recognition (MSR) in humans. Testing MSR has become the main approach to examining the existence of self-recognition in animals, and only a few species have passed the test. However, it remains controversial whether failing the MSR test is a result of the lack of an animal’s self-recognition ability or the inadequacy of the mirror test. We found that MSR spontaneously appeared in rhesus monkeys after training for precise visual-proprioceptive association for mirror images. Thus, bodily self-consciousness may be a cognitive ability present in many more species than previously thought, and could be revealed by MSR when the animal acquired visual-proprioceptive association for the images in the mirror.
Systems analysis of protective immune responses to RTS,S malaria vaccination in humans
Authors: Kazmin Dmitri , Nakaya Helder I. , Lee Eva K. , Johnson Matthew J. , van der Most Robbert , van den Berg Robert A. , Ballou W. Ripley , Jongert Erik , Wille-Reece Ulrike , Ockenhouse Christian , Aderem Alan , Zak Daniel E. , Sadoff Jerald , Hendriks Jenny , Wrammert Jens , Ahmed Rafi , Pulendran Bali
Published: February 2017

Significance

The RTS,S malaria vaccine is the most advanced malaria vaccine candidate to be tested in humans. Despite its promise, there is little understanding of its mechanism of action. In this work, we describe the use of a systems biological approach to identify “molecular signatures” that are induced rapidly after the standard RTS,S vaccination regimen, consisting of three RTS,S immunizations, or with a different regimen consisting of a primary immunization with recombinant adenovirus 35 (Ad35) expressing the circumsporozoite malaria antigen followed by two immunizations with RTS,S. These results reveal important insights about the innate and adaptive responses to vaccination and identify signatures of protective immunity against malaria.
BMP signaling controls buckling forces to modulate looping morphogenesis of the gut
Authors: Nerurkar Nandan L. , Mahadevan L. , Tabin Clifford J.
Published: February 2017

Significance

During embryogenesis, the dramatic transformation from a seemingly disorganized mass of cells into the fully patterned adult form necessitates stereotyped regulation of forces at the genetic and molecular level. Although great progress has been made in understanding how gene expression and signaling generate biological pattern, little is known about how molecular cues organize forces to sculpt physical patterns during development. The present work identifies BMP signaling as a key pathway in controlling looping of the small intestine, a process driven by mechanical buckling due to elongation of the intestine against the constraint of a neighboring tissue, the dorsal mesentery.
Postural stability, clicker reaction time and bow draw force predict performance in elite recurve archery
Authors: Spratford Wayne , Campbell Rhiannon
Published: February 2017

Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre‐ and post‐arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty‐nine elite‐level recurve archers (23 male and 16 female; mean age = 24.7 ± 7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post‐arrow release. High‐speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post‐arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers.
Trajectories of illegality and informality in conflict protraction: the Abkhaz-Georgian case
Authors: Oltramonti Giulia Prelz
Published: February 2017

This article explores how the protraction of conflict shapes the management of economic activities and, more specifically, the illegality/informality divide. Its main argument is that, in contexts of conflict protraction, informal activities are managed and criminalized by a range of actors in function of their capacity and their strategies to project their authority and sovereignty. It identifies an “informality/illegality divide” that runs largely parallel to the gap between de jure and de facto regulation of activities in areas affected by conflict protraction. This relationship between regulation and conflict protraction is then triangulated with the issues of disputed sovereignty and legal voids. These topics are explored against the backdrop of the Abkhaz-Georgian protracted conflict, analysing Georgian and Abkhaz (de facto) authorities’ stakes in processes of informality, illegality, regulation, and criminalization of a variety of economic activities.
Symptom Development in Response to Combined Infection of In Vitro-grown Lilium longiflorum with Pratylenchus penetrans and Soilborne Fungi Collected from Diseased Roots of Field-grown Lilies
Authors: Lakshman Dilip , Vieira Paulo , Pandey Ruchi , Slovin Janet , Kamo Kathryn
Published: February 2017

Eight fungal isolates (ELRF 1 to 8) were recovered from necrotic roots of Easter lilies, Lilium longiflorum cv. Nellie White, grown in a field in the U.S. Pacific Northwest. The eight fungal isolates were identified by sequencing and molecular phylogenetic analyses based on their ITS rDNA region. Five isolates were identified as Fusarium oxysporum, two as F. tricinctum, and one as Rhizoctonia sp. AG-I. This constitutes the first report of Rhizoctonia sp. AG-I infecting lilies worldwide and the first report of F. tricinctum infecting lilies in the United States. To study and validate their pathogenicity, pure cultures of each isolate were used to infect the roots of Easter lily plants growing in vitro. In addition, Easter lily plants growing in vitro were infected either with or without Pratylenchus penetrans, the root lesion nematode, prior to placing a culture plug of fungus 1 cm from a lily root. Pratylenchus penetrans is a nematode species commonly found in the sampled fields. The presence of both nematode and Rhizoctonia sp. AG-I isolate ELRF 3 in infected lilies was evaluated by molecular analyses, confirming the infection of roots 3 days after inoculation, prior to development of disease symptoms. Necrosis and root rot developed more rapidly with all eight fungal isolates when there had been prior infection with P. penetrans, the major nematode parasitizing Easter lily roots in the field in Oregon.
Effect of Abamectin on the Cereal Cyst Nematode (CCN, Heterodera avenae) and Wheat Yield
Authors: Zhang Dianli , Wang Hongyan , Ji Xiaoxue , Wang Kaiyun , Wang Dong , Qiao Kang
Published: February 2017

The cereal cyst nematode (CCN, Heterodera avenae) is a major pest in wheat and until now there is no pesticide registered to control this pest in China. Development of effective methods of controlling CCN is urgently needed. Abamectin is a biological pesticide that has a high nematicide activity. However, the efficacy of abamectin soil application to control CCN in wheat and its effect on yield in China remains unknown. Therefore, laboratory, greenhouse, and field tests were carried out to evaluate the potential of abamectin soil applications for CCN control and improvement of wheat yield. Laboratory tests showed that abamectin exhibited knockdown toxicity to CCN, with LC50 and LC90 values 9.8 and 59.4 mg liter–1. Greenhouse experiment and field trials showed that soil applications of abamectin provided significant CCN control and higher straw dry weights and wheat grain yields. There was an 8.5 to 19.3% yield increase from the various abamectin treatments compared with the control. The results of this study demonstrated that abamectin exhibited a high nematicidal activity to H. avenae and adequate performance to enhance wheat crop yields.
Phytophthora infestans Effectors IPI-O1 and IPI-O4 Each Contribute to Pathogen Virulence
Authors: Chen Yu , Halterman Dennis A.
Published: February 2017

Potato late blight, caused by the oomycete pathogen Phytophthora infestans, is one of the most destructive plant diseases. Despite decades of intensive breeding efforts, it remains a threat to potato production worldwide, because newly evolved pathogen strains have overcome major resistance genes quickly. The RB protein, from the diploid wild potato species Solanum bulbocastanum, confers partial resistance to most P. infestans strains through its recognition of members of the corresponding pathogen effector protein family IPI-O. IPI-O comprises a multigene family and while some variants are recognized by RB to elicit host resistance (e.g., IPI-O1 and IPI-O2), others are able to elude detection (e.g., IPI-O4). IPI-O1 is almost ubiquitous in global P. infestans strains while IPI-O4 is more rare. No direct experimental evidence has been shown to demonstrate the effect of IPI-O on pathogen virulence in the P. infestans−potato pathosystem. Here, our work has demonstrated that in planta expression of both IPI-O1 and IPI-O4 increases P. infestans aggressiveness resulting in enlarged lesions in potato leaflets. We have previously shown that IPI-O4 has gained the ability to suppress the hypersensitive response induced by IPI-O1 in the presence of RB. In this study, our work has shown that this gain-of-function of IPI-O4 does not compromise its virulence effect, as IPI-O4 overexpression results in larger lesions than IPI-O1. We have also found that higher expression of IPI-O effectors correlates with enlarged lesions, indicating that IPI-O can contribute to virulence quantitatively. In summary, this study has provided accurate and valuable information on IPI-O’s virulence effect on the potato host.