bluuebunny/crossref_metadata_2025 huggingface dataset:
Power conversion efficiency and resistance tunability in coil-magnetoelectric gyrators
Authors: Leung Chung Ming , Zhuang Xin , Xu Junran , Srinivasan G. , Li Jiefang , Viehland D.
Published: November 2016

The power efficiency and resistance tunability of magnetoelectric (ME) gyrators consisting of two-phase magnetostrictive-piezoelectric ME longitudinal-transverse (L-T) mode sandwich laminates and coils, have been studied. The copper wire coil provided an inductance-based coil port (CoilP) and the piezoelectric layer of the ME laminate provided a capacitance-based ME port (MEP). The device behaved as a 2-port 4-wire ME gyrator. The current-to-voltage and voltage-to-current (I-V and V-I, respectively) conversion ratios, resistance-inductance/capacitance tunabilities (TR-L and TR-C, respectively) and direct/converse power efficiencies (PED and PEC, respectively) were measured. Maximum values of 1454 V/A and 0.468 mA/V for the I-V and V-I conversion ratios, 76 μH/Ω and 0.17 pF/Ω for TR-L and TR-C coefficients, and ∼35% for both PED and PEC were found by measuring the performance characteristics. Compared with the electromagnetic and piezoelectric transformers, ME gyrators have good input and output characteristics that change the capacitance and inductance features of the input and output ports. Our findings open a promising direction for developing a generation of converters for power electronics.
On synchronization in power-grids modelled as networks of second-order Kuramoto oscillators
Authors: Grzybowski J. M. V. , Macau E. E. N. , Yoneyama T.
Published: November 2016

This work concerns analytical results on the role of coupling strength in the phenomenon of onset of complete frequency locking in power-grids modelled as a network of second-order Kuramoto oscillators. Those results allow estimation of the coupling strength for the onset of complete frequency locking and to assess the features of network and oscillators that favor synchronization. The analytical results are evaluated using an order parameter defined as the normalized sum of absolute values of phase deviations of the oscillators over time. The investigation of the frequency synchronization within the subsets of the parameter space involved in the synchronization problem is also carried out. It is shown that the analytical results are in good agreement with those observed in the numerical simulations. In order to illustrate the methodology, a case study is presented, involving the Brazilian high-voltage transmission system under a load peak condition to study the effect of load on the syncronizability of the grid. The results show that both the load and the centralized generation might have concurred to the 2014 blackout.
Analysis of polarization speckle for imaging through random birefringent scatterer
Authors: Roy Abhijit , Singh Rakesh K. , Brundavanam Maruthi M.
Published: November 2016

Propagation of a coherent light through an anisotropic random medium generates randomly polarized field, known as polarization speckle. In this paper, an experimental technique is proposed and demonstrated to recover the transmittance of a polarized object from polarization speckle. Recovery of the polarized object from polarization speckle is made possible by combining the far-field intensity correlation of the object speckle with off-axis holography to determine the complex coherence function of the speckle. The desired object speckle which is uniformly polarized is filtered from the polarization speckle using a polarizer. The results are compared with the case where the complex coherence function is determined in the absence of the polarizer.
Symmetry and diffusivity of the interstitial hydrogen shallow-donor center in In2O3
Authors: Weiser Philip , Qin Ying , Yin Weikai , Stavola Michael , Fowler W. Beall , Boatner Lynn A.
Published: November 2016

Uniaxial-stress experiments performed for the 3306 cm−1 vibrational line assigned to the interstitial-hydrogen, shallow-donor center in In2O3 reveal its symmetry and transition-moment direction. The defect alignment that can be produced by a [001] stress applied at 165 K is due to a process that is also a hydrogen-diffusion jump, providing a microscopic determination of the diffusion constant for H in In2O3 and its mechanism. Our experimental results strongly complement the theoretical predictions for the structure and diffusion of the interstitial hydrogen donor center in In2O3.
Numerical conversion efficiency of thermally isolated Seebeck nanoantennas
Authors: Briones Edgar , Kuri Carlos , Cortes-Mestizo Irving , Briones Joel , Vilchis Heber
Published: November 2016

In this letter, we evaluate the conversion efficiency of thermally isolated Seebeck nanoantennas by numerical simulations and discuss their uses and scope for energy harvesting applications. This analysis includes the simple case of titanium-nickel dipoles suspended in air above the substrate by a 200 nm silicon dioxide membrane to isolate the heat dissipation. Results show that substantially thermal gradients are induced along the devices leading to a harvesting efficiency around 10-4 %, 400 % higher than the previously reported Seebeck nanoantennas. In the light of these results, different optimizing strategies should be considered in order to make the Seebeck nanoantennas useful for harvesting applications.
Separation of superparamagnetic particles through ratcheted Brownian motion and periodically switching magnetic fields
Authors: Liu Fan , Jiang Li , Tan Huei Ming , Yadav Ashutosh , Biswas Preetika , van der Maarel Johan R. C. , Nijhuis Christian A. , van Kan Jeroen A.
Published: November 2016

Brownian ratchet based particle separation systems for application in lab on chip devices have drawn interest and are subject to ongoing theoretical and experimental investigations. We demonstrate a compact microfluidic particle separation chip, which implements an extended on-off Brownian ratchet scheme that actively separates and sorts particles using periodically switching magnetic fields, asymmetric sawtooth channel sidewalls, and Brownian motion. The microfluidic chip was made with Polydimethylsiloxane (PDMS) soft lithography of SU-8 molds, which in turn was fabricated using Proton Beam Writing. After bonding of the PDMS chip to a glass substrate through surface activation by oxygen plasma treatment, embedded electromagnets were cofabricated by the injection of InSn metal into electrode channels. This fabrication process enables rapid production of high resolution and high aspect ratio features, which results in parallel electrodes accurately aligned with respect to the separation channel. The PDMS devices were tested with mixtures of 1.51 μm, 2.47 μm, and 2.60 μm superparamagnetic particles suspended in water. Experimental results show that the current device design has potential for separating particles with a size difference around 130 nm. Based on the promising results, we will be working towards extending this design for the separation of cells or biomolecules.
Strain controlled valley filtering in multi-terminal graphene structures
Authors: Milovanović S. P. , Peeters F. M.
Published: November 2016

Valley-polarized currents can be generated by local straining of multi-terminal graphene devices. The pseudo-magnetic field created by the deformation allows electrons from only one valley to transmit, and a current of electrons from a single valley is generated at the opposite side of the locally strained region. We show that valley filtering is most effective with bumps of a certain height and width. Despite the fact that the highest contribution to the polarized current comes from electrons from the lowest sub-band, contributions of other sub-bands are not negligible and can significantly enhance the output current.
In-situ real-space imaging of single crystal surface reconstructions via electron microscopy
Authors: Xu Weizong , Bowes Preston C. , Grimley Everett D. , Irving Douglas L. , LeBeau James M.
Published: November 2016

Here, we report a high temperature in-situ atomic resolution scanning transmission electron microscopy (STEM) study of single crystal surface structure dynamics. With the approach, we gain direct insight into a double layer reconstruction that occurs on the polar SrTiO3 (110) surface. We find that structural details of this reconstruction can be directly attributed to charge redistribution and the thermal mismatch between the surface and the bulk material. Periodic surface defects, similar to dislocations, are found, which act to relieve stress as the temperature is lowered. Combining STEM observations, electron energy loss spectroscopy, and density functional theory, we highlight the combined role of lattice misfit and charge compensation to determine the structure and chemistry of the observed polar surface reconstruction.
Band slope in CdS layer of ZnO:Ga/CdS/Cu2ZnSnS4 photovoltaic cells revealed by hard X-ray photoelectron spectroscopy
Authors: Kataoka Keita , Tajima Shin , Umehara Mitsutaro , Takahashi Naoko , Isomura Noritake , Kitazumi Kosuke , Kimoto Yasuji
Published: November 2016

For compound semiconductor photovoltaic cells with a common structure of the window-layer (WL)/buffer-layer (BL)/absorbing-layer (AL), the band slope in BLs, affecting the conversion efficiency, was directly and non-destructively measured by hard X-ray photoelectron spectroscopy. We demonstrated that the band slope in CdS-BLs sandwiched between WLs and Cu2ZnSnS4 (CZTS)-ALs reflected the trend of the work functions of WLs (ϕWL). This result implies that the larger downward band slope to the WL can be achieved using a smaller ϕWL. The relatively large downward band slope of ∼0.5 eV to the WL was estimated in our ZnO:Ga/CdS/CZTS sample with a higher conversion efficiency of 9.4%, which indicates that the conversion efficiency of CZTS cells can be improved by a larger downward band slope to the WL.
Voltage-impulse-induced dual-range nonvolatile magnetization modulation in metglas/PZT heterostructure
Authors: Tang Xiaoli , Su Hua , Zhang Huaiwu , Sun Nian X.
Published: November 2016

Dual-range, nonvolatile magnetization modulation induced by voltage impulses was investigated in the metglas/lead zirconate titanate (PZT) heterostructure at room temperature. The heterostructure was obtained by bonding a square metglas ribbon on the top electrode of the PZT substrate, which contained defect dipoles resulting from acceptor doping. The PZT substrate achieved two strain hysteretic loops with the application of specific voltage impulse excitation modes. Through strain-mediated magnetoelectric coupling between the metglas ribbon and the PZT substrate, two strain hysteretic loops led to a dual-range nonvolatile magnetization modulation in the heterostructure. Reversible and stable voltage-impulse-induced nonvolatile modulation in the ferromagnetic resonance field and magnetic hysteresis characteristics were also realized. This method provides a promising approach in reducing energy consumption in magnetization modulation and other related devices.
High performance photodetector based on Pd-single layer MoS2 Schottky junction
Authors: Wang Xue-Feng , Zhao Hai-Ming , Shen Shu-Hong , Pang Yu , Shao Peng-Zhi , Li Yu-Tao , Deng Ning-Qin , Li Yu-Xing , Yang Yi , Ren Tian-Ling
Published: November 2016

Due to excellent photoelectric property of single layer molybdenum disulphide (SL MoS2), different kinds of photodetectors based on SL MoS2 have been reported. Although high photosensitivity was obtained, the rising and decay time of photocurrent were relatively large (>300 ms) when the current reached up to μA order. In this paper, we demonstrate a high sensitive and fast barrier type photodetector based on Pd-SL MoS2 Schottky junction. The photosensitivity can reach up to 0.88 A/W at 425 nm laser. Compared with SL MoS2 photodetectors based on ohmic contact, our device shows much shorter rising and a decay time of 24.7 ms and 24.5 ms, respectively, exhibiting the merit of barrier type photodetector.
Lattice vibrations and electrical transport in (Bi1−xInx)2Se3 films
Authors: Zhu Jiajun , Liu Fang , Zhou Shengqiang , Franke C. , Wimmer S. , Volobuev V. V. , Springholz G. , Pashkin A. , Schneider H. , Helm M.
Published: November 2016

We present Raman, terahertz transmission, and transport measurements on (Bi1−xInx)2Se3 films to study the evolution of phonon modes and resistivity with an increasing indium content across the metal-insulator phase transition. The frequencies of two Raman-active modes Eg2 and A1g2 as well as an infrared-active mode Eu increase with an increasing indium content due to the smaller atomic weight of indium compared to bismuth. Terahertz data are fitted by a Drude-Lorentz model. Drude scattering rates increase from 47 to 75 cm−1 with an increasing indium content from 0% to 16% due to stronger impurity scattering. The carrier concentration drops significantly for x = 24%. The temperature dependence of the resistivity switches from metallic at x = 16% to insulating at x = 24%, indicating a metal-insulator transition in between.
Optimized electrocaloric effect by field reversal: Analytical model
Authors: Ma Yang-Bin , Novak Nikola , Albe Karsten , Xu Bai-Xiang
Published: November 2016

Applying a negative field on a positively poled ferroelectric sample can enhance the electrocaloric cooling and is a promising method to optimize the electrocaloric cycle. Experimental measurements show that the maximal cooling is not obtained, when the electric field is removed, but reversed to a value corresponding to the shoulder of the P-E loop. This phenomenon cannot be explained if a constant total entropy is assumed under adiabatic conditions. Thus, a direct analysis of entropy changes based on work loss is proposed in this work, which takes the entropy contribution of the irreversible process into account. The optimal reversed field determined by this approach agrees with the experimental observations. This study signifies the importance of considering irreversible process in the electrocaloric cycles.
Magnetization reversal in ferromagnetic spirals via domain wall motion
Authors: Schumm Ryan D. , Kunz Andrew
Published: November 2016

Domain wall dynamics have been investigated in a variety of ferromagnetic nanostructures for potential applications in logic, sensing, and recording. We present a combination of analytic and simulated results describing the reliable field driven motion of a domain wall through the arms of a ferromagnetic spiral nanowire. The spiral geometry is capable of taking advantage of the benefits of both straight and circular wires. Measurements of the in-plane components of the spirals' magnetization can be used to determine the angular location of the domain wall, impacting the magnetoresistive applications dependent on the domain wall location. The spirals' magnetization components are found to depend on the spiral parameters: the initial radius and spacing between spiral arms, along with the domain wall location. The magnetization is independent of the parameters of the rotating field used to move the domain wall, and therefore the model is valid for current induced domain wall motion as well. The speed of the domain wall is found to depend on the frequency of the rotating driving field, and the domain wall speeds can be reliably varied over several orders of magnitude. We further demonstrate a technique capable of injecting multiple domain walls and show the reliable and unidirectional motion of domain walls through the arms of the spiral.
Influence of GaN column diameter on structural properties for InGaN nanocolumns grown on top of GaN nanocolumns
Authors: Oto Takao , Mizuno Yutaro , Yanagihara Ai , Miyagawa Rin , Kano Tatsuya , Yoshida Jun , Sakakibara Naoki , Kishino Katsumi
Published: November 2016

The influence of GaN column diameter DGaN on structural properties was systematically investigated for InGaN nanocolumns (NCs) grown on top of GaN NCs. We demonstrated a large critical layer thickness of above 400 nm for In0.3Ga0.7N/GaN NCs. The structural properties were changed at the boundary of DGaN=D0 (∼120 nm). Homogeneous InGaN NCs grew axially on the GaN NCs with DGaN≤D0, while InGaN-InGaN core-shell structures were spontaneously formed on the GaN NCs with DGaN>D0. These results can be explained by a growth system that minimizes the total strain energy of the NCs.
Sol-gel synthesis and characterization of undoped and Al-doped ZnO thin films for memristive application
Authors: Ayana Dawit G. , Prusakova Valentina , Collini Cristian , Nardi Marco V. , Tatti Roberta , Bortolotti Mauro , Lorenzelli Leandro , Chiappini Andrea , Chiasera Alessandro , Ferrari Maurizio , Lunelli Lorenzo , Dirè Sandra
Published: November 2016

The Sol-gel route is a versatile method to fabricate multi-layer, dense and homogeneous ZnO thin films with a controlled thickness and defects for a memristive application. In this work, sol-gel derived multi-layer undoped and Al-doped ZnO thin films were prepared by a spin-coating technique on SiO2/Ti/Pt and silica glass substrates. The effect of both Al doping and curing conditions on the structural and morphological features of ZnO films was investigated by complementary techniques, including electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction analysis. Electrical measurements were performed on SiO2/Ti/Pt/ZnO/Pt(dishes) and SiO2/Ti/Pt/ZnO(Al)/Pt(dishes) fabricated memristive cells and preliminary current-voltage curves were acquired.
Unreasonable effectiveness of learning neural networks: From accessible states and robust ensembles to basic algorithmic schemes
Authors: Baldassi Carlo , Borgs Christian , Chayes Jennifer T. , Ingrosso Alessandro , Lucibello Carlo , Saglietti Luca , Zecchina Riccardo
Published: November 2016

Significance

Artificial neural networks are some of the most widely used tools in data science. Learning is, in principle, a hard problem in these systems, but in practice heuristic algorithms often find solutions with good generalization properties. We propose an explanation of this good performance in terms of a nonequilibrium statistical physics framework: We show that there are regions of the optimization landscape that are both robust and accessible and that their existence is crucial to achieve good performance on a class of particularly difficult learning problems. Building on these results, we introduce a basic algorithmic scheme that improves existing optimization algorithms and provides a framework for further research on learning in neural networks.
Trypanosoma bruceimetabolite indolepyruvate decreases HIF-1α and glycolysis in macrophages as a mechanism of innate immune evasion
Authors: McGettrick Anne F. , Corcoran Sarah E. , Barry Paul J. G. , McFarland Jennifer , Crès Cécile , Curtis Anne M. , Franklin Edward , Corr Sinéad C. , Mok K. Hun , Cummins Eoin P. , Taylor Cormac T. , O’Neill Luke A. J. , Nolan Derek P.
Published: November 2016

Significance

The parasiteTrypanosoma bruceicauses African sleeping sickness. This disease, which lacks effective treatments, affects millions of humans and livestock in sub-Saharan Africa. This paper reveals a mechanism by which the parasite can evade our immune response. Indolepyruvate is a metabolite produced by the parasite and it manipulates the immune cells, called macrophages, preventing them from becoming fully active. The selective advantage for the parasite of excretion of indolepyruvate is possible modulation of host inflammatory responses to prolong host survival, thereby potentiating transmission of the parasite to the tsetse fly vector and ensuring completion of the life cycle. This discovery could lead to new drug targets and better treatments.
Control of seed dormancy in
Arabidopsis
by a
cis
-acting noncoding antisense transcript
Authors: Fedak Halina , Palusinska Malgorzata , Krzyczmonik Katarzyna , Brzezniak Lien , Yatusevich Ruslan , Pietras Zbigniew , Kaczanowski Szymon , Swiezewski Szymon
Published: November 2016

Significance

Sequential developmental transitions in plant life cycle are tightly controlled by dynamic regulation of key genes. Seed dormancy release is probably the first developmental transition in a plant’s life cycle, and it is regulated by the Delay of Germination 1 (
DOG1
) gene. Here we demonstrate that a nonprotein-coding antisense transcript originating from a conserved at DNA—but not protein level—
DOG1
region is a negative regulator of
DOG1
expression and seed dormancy establishment. We show that this antisense transcript negatively regulates
DOG1
expression in
cis
. This mechanism is presumably conserved across the Brassicaceae, given the evolutionary conservation of the antisense
DOG1
promoter.
Global transformation of erythrocyte properties via engagement of an SH2-like sequence in band 3
Authors: Puchulu-Campanella Estela , Turrini Francesco M. , Li Yen-Hsing , Low Philip S.
Published: November 2016

Significance

Src homology 2 (SH2) domains regulate signaling by binding phosphotyrosines. While all known SH2 domains consist of contiguous sequences of ∼100 aa, we describe a highly conserved SH2-like sequence motif located in the second cytoplasmic loop of membrane-spanning domain of erythrocyte membrane band 3. Upon tyrosine phosphorylation of the cytoplasmic domain of band 3, the domain rotates to bind the SH2 signature sequence within the membrane-spanning domain of band 3, promoting significant changes in erythrocyte properties. Because sequence homology searches do not recognize SH2-like sequence motifs, the possibility arises that many other SH2-like structures remain undetected in membrane-spanning proteins where they perform critical steps in kinase-facilitated signaling pathways.
Control of
Hoxd
gene transcription in the mammary bud by hijacking a preexisting regulatory landscape
Authors: Schep Ruben , Necsulea Anamaria , Rodríguez-Carballo Eddie , Guerreiro Isabel , Andrey Guillaume , Nguyen Huynh Thi Hanh , Marcet Virginie , Zákány Jozsef , Duboule Denis , Beccari Leonardo
Published: November 2016

Significance

During vertebrate evolution,
Hox
gene function was coopted through the emergence of global enhancers outside the
Hox
gene clusters. Here, we analyze the regulatory modalities underlying
Hoxd
gene transcription into the developing mammary glands where
Hox
proteins are necessary. We report the existence of a long-distance acting mammary bud enhancer located near sequences involved in controlling
Hox
genes in the limbs. We argue that the particular constitutive chromatin structure found at this locus facilitated the emergence of this enhancer element in mammals by hijacking a regulatory context at work in other cell types, supporting a model wherein enhancer sequences tend to cluster into large regulatory landscapes due to an increased probability to evolve within a preexisting regulatory structure.
Achieving high power factor and output power density in p-type half-Heuslers Nb
1-x
Ti
x
FeSb
Authors: He Ran , Kraemer Daniel , Mao Jun , Zeng Lingping , Jie Qing , Lan Yucheng , Li Chunhua , Shuai Jing , Kim Hee Seok , Liu Yuan , Broido David , Chu Ching-Wu , Chen Gang , Ren Zhifeng
Published: November 2016

Significance

Thermoelectric technology can boost energy consumption efficiency by converting some of the waste heat into useful electricity. Heat-to-power conversion efficiency optimization is mainly achieved by decreasing the thermal conductivity in many materials. In comparison, there has been much less success in increasing the power factor. We report successful power factor enhancement by improving the carrier mobility. Our successful approach could suggest methods to improve the power factor in other materials. Using our approach, the highest power factor reaches ∼106 μW⋅cm
−1
⋅K
−2
at room temperature. Such a high power factor further yields a record output power density in a single-leg device tested between 293 K and 868 K, thus demonstrating the importance of high power factor for power generation applications.
Dampened antiviral immunity to intravaginal exposure to RNA viral pathogens allows enhanced viral replication
Authors: Khan Shahzada , Woodruff Erik M. , Trapecar Martin , Fontaine Krystal A. , Ezaki Ashley , Borbet Timothy C. , Ott Melanie , Sanjabi Shomyseh
Published: November 2016

Understanding the host immune response to vaginal exposure to RNA viruses is required to combat sexual transmission of this class of pathogens. In this study, using lymphocytic choriomeningitis virus (LCMV) and Zika virus (ZIKV) in wild-type mice, we show that these viruses replicate in the vaginal mucosa with minimal induction of antiviral interferon and inflammatory response, causing dampened innate-mediated control of viral replication and a failure to mature local antigen-presenting cells (APCs). Enhancement of innate-mediated inflammation in the vaginal mucosa rescues this phenotype and completely inhibits ZIKV replication. To gain a better understanding of how this dampened innate immune activation in the lower female reproductive tract may also affect adaptive immunity, we modeled CD8 T cell responses using vaginal LCMV infection. We show that the lack of APC maturation in the vaginal mucosa leads to a delay in CD8 T cell activation in the draining lymph node and hinders the timely appearance of effector CD8 T cells in vaginal mucosa, thus further delaying viral control in this tissue. Our study demonstrates that vaginal tissue is exceptionally vulnerable to infection by RNA viruses and provides a conceptual framework for the male to female sexual transmission observed during ZIKV infection.
A Modeling Approach for Mechanisms Featuring Causal Cycles
Authors: Gebharter Alexander , Schurz Gerhard
Published: November 2016

Mechanisms play an important role in many sciences when it comes to questions concerning explanation, prediction, and control. Answering such questions in a quantitative way requires a formal representation of mechanisms. Gebharter’s “A Formal Framework for Representing Mechanisms?” suggests to represent mechanisms by means of arrows in an acyclic causal net. In this article we show how this approach can be extended in such a way that it can also be fruitfully applied to mechanisms featuring causal feedback.
The CCL-K11 ongoing key comparison. Final report for the year 2015
Authors: Matus Michael , Berg Steven van den , Czulek Dariusz , Seppä Jeremias , Robertsson Lennart
Published: November 2016

Lasers from two national metrological institutes (NMIs) were compared in 2015 as part of the CCL-K11 ongoing key comparison, initiated by the 13th meeting of the Comité Consultative des Longuers (CCL) in 2007. The absolute frequency of R(127) 11-5 transitions of molecular iodine was measured for these lasers following the technical protocol for CCL-K11. The results of these measurements are compiled in the present report. The comparison reports, as communicated by each participant, are included as appendices.

This document constitutes the seventh final report for the ongoing key comparison CCL-K11.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Efficiency Impacts of Utilizing Soil Data in the Pricing of the Federal Crop Insurance Program
Authors: Woodard Joshua D. , Verteramo‐Chiu Leslie J.
Published: November 2016

Since the Agricultural Act of 2014, the federal crop insurance program (FCIP) has been the cornerstone agricultural policy in the United States, and is the largest such program globally, with about $100 billion in coverage annually. Given its scale and scope, the FCIP has the potential to have pervasive impacts on incentives and policy functioning if not designed and priced properly. Surprisingly, soil data are not considered by the government when establishing insurance guarantees or rates. Using soil data that could easily and feasibly be scaled nationally, we find that the pricing differentials caused by the government′s failure to handle soil information leads to large errors in rating.
Role of Nitric Oxide Synthase on Blood Pressure Regulation and Vascular Function in Pregnant Rats on a High-Fat Diet
Authors: Palei Ana C. , Spradley Frank T. , Granger Joey P.
Published: November 2016

BACKGROUND

While obesity is a leading risk factor for preeclampsia, the mechanisms whereby obese women are more susceptible to pregnancy-induced hypertension are unclear. As high-fat diet (HFD) is an important contributor to the development of obesity, we tested the hypothesis that pregnant rats on HFD have hypertension and endothelial dysfunction due to reduced nitric oxide synthase (NOS).

METHODS

Twelve-week-old Sprague-Dawley female rats were fed normal diet (ND, 13% fat kcal) or HFD (40% fat kcal) for 9 weeks. Timed-pregnant rats were then generated and the effect of HFD on mean arterial blood pressure (MAP) and vascular function was assessed on gestational day (GD) 19.

RESULTS

MAP was not different between HFD and ND pregnant rats. Intriguingly, sensitivity to acetylcholine-induced endothelium-dependent vasorelaxation was enhanced in small mesenteric arteries of HFD dams compared to ND controls (logEC50 −7.9 ± 0.3 vs. −6.7 ± 0.3 M; P < 0.05). Additionally, HFD dams exhibited higher mesenteric artery expression of NOS3 and plasma levels of NO metabolites than ND controls (1738.0 ± 316.4 vs. 1094.0 ± 82.5 pg/mg and 72.5 ± 8.7 vs. 39.7 ± 4.5 µM, respectively; both P < 0.05). Further, to determine the role of NOS in modulating blood pressure in HFD pregnant rats, animals were treated with the nonselective inhibitor Nω-Nitro-l-arginine methyl ester hydrochloride (100 mg/l, drinking water) from GD 14 to 19. It was found that NOS inhibition increased MAP equally in HFD and ND groups.

CONCLUSIONS

Contrary to our initial hypothesis, HFD dams were normotensive and presented increased endothelial function and NO/NOS3 levels. This enhanced NOS-mediated vascular function does not appear to have a major impact on blood pressure regulation of HFD-fed pregnant rats.
DACE: a scalable DP-means algorithm for clustering extremely large sequence data
Authors: Jiang Linhao , Dong Yichao , Chen Ning , Chen Ting
Published: November 2016

Motivation

Advancements in next-generation sequencing technology have produced large amounts of reads at low cost in a short time. In metagenomics, 16S and 18S rRNA gene have been widely used as marker genes to profile diversity of microorganisms in environmental samples. Through clustering of sequencing reads we can determine both number of OTUs and their relative abundance. In many applications, clustering of very large sequencing data with high efficiency and accuracy is essential for downstream analysis.

Results

Here, we report a scalable Dirichlet Process Means (DP-means) algorithm for clustering extremely large sequencing data, termed DACE. With an efficient random projection partition strategy for parallel clustering, DACE can cluster billions of sequences within a couple of hours. Experimental results show that DACE runs between 6 and 80 times faster than state-of-the-art programs, while maintaining overall better clustering accuracy. Using 80 cores, DACE clustered the Lake Taihu 16S rRNA gene sequencing data (∼316M reads, 30 GB) in 25 min, and the Ocean TARA Eukaryotic 18S rRNA gene sequencing data (∼500M reads, 88 GB) into ∼100 000 clusters within an hour. When applied to the IGC gene catalogs in human gut microbiome (∼10M genes), DACE produced 9.8M clusters with 52K redundant genes in 1.5 hours of running time.

Availability and Implementation

DACE is available at https://github.com/tinglab/DACE.

Supplementary information

Supplementary data are available at Bioinformatics online.
A comprehensive benchmark of RNA–RNA interaction prediction tools for all domains of life
Authors: Umu Sinan Uğur , Gardner Paul P
Published: November 2016

Motivation

The aim of this study is to assess the performance of RNA–RNA interaction prediction tools for all domains of life.

Results

Minimum free energy (MFE) and alignment methods constitute most of the current RNA interaction prediction algorithms. The MFE tools that include accessibility (i.e. RNAup, IntaRNA and RNAplex) to the final predicted binding energy have better true positive rates (TPRs) with a high positive predictive values (PPVs) in all datasets than other methods. They can also differentiate almost half of the native interactions from background. The algorithms that include effects of internal binding energies to their model and alignment methods seem to have high TPR but relatively low associated PPV compared to accessibility based methods.

Availability and Implementation

We shared our wrapper scripts and datasets at Github (github.com/UCanCompBio/RNA_Interactions_Benchmark). All parameters are documented for personal use.

Supplementary information

Supplementary data are available at Bioinformatics online.
Systemic Elevation of Proinflammatory Interleukin-18 in Human Immunodeficiency Virus (HIV)/Hepatitis C Virus (HCV) Coinfection Versus HIV or HCV Monoinfection
Authors: Veenhuis Rebecca T. , Astemborski Jacquie , Chattergoon Michael A. , Greenwood Paige , Jarosinski Marissa , Moore Richard D. , Mehta Shruti H. , Cox Andrea L.
Published: November 2016

Background.

Human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection and elevated interleukin (IL)-18 levels are both associated with enhanced progression of hepatic inflammation and increased risk of diabetes, kidney disease, and cardiovascular disease. IL-18 is a proinflammatory cytokine made upon activation of the inflammasome, an innate sensing system. We assessed whether increased IL-18 could explain the increased incidence and progression of inflammatory conditions seen with HIV/HCV coinfection.

Methods.

Serum samples from 559 subjects with HIV monoinfection, HCV monoinfection, HIV/HCV coinfection, or people who inject drugs with neither infection were tested for IL-18 by enzyme-linked immunosorbent assay and for 16 other analytes by electrochemiluminescence immunoassay. IL-18 levels were measured in 14 additional chronically HCV-infected subjects who developed incident HIV infection to determine if IL-18 increases with coinfection.

Results.

IL-18 was significantly elevated in coinfected individuals vs both monoinfections (P < .0001) independent of age, sex, and race. IL-18 levels were significantly higher in HIV monoinfection than in HCV monoinfection. High IL-18 levels were correlated with detectable HIV viremia and inversely with CD4 cell count (P < .0001), consistent with HIV activation of the inflammasome resulting in CD4 T-cell depletion. Incident HIV infection of chronically HCV-infected subjects resulted in increased IL-18 (P < .001), while HIV suppression was associated with normal IL-18 levels. Four additional analytes (IP-10, IL-12/23p40, IFN-γ, IL-15) were found to be elevated in HIV/HCV coinfection when compared to both monoinfections.

Conclusions.

HIV/HCV coinfection results in significantly elevated serum IL-18. The elevated levels of this proinflammatory cytokine may explain the increased incidence and progression of inflammatory illnesses seen in coinfected individuals.
A ghostly damped Ly α system revealed by metal absorption lines
Authors: Fathivavsari H. , Petitjean P. , Zou S. , Noterdaeme P. , Ledoux C. , Krühler T. , Srianand R.
Published: November 2016

We report the discovery of the first ‘ghostly’ damped Ly α absorption system (DLA), which is identified by the presence of absorption from strong low-ion species at zabs = 1.704 65 along the line of sight to the quasar SDSS J113341.29−005740.0 with zem = 1.704 41. No Ly α absorption trough is seen associated with these absorptions because the DLA trough is filled with the leaked emission from the broad emission-line region of the quasar. By modelling the quasar spectrum and analysing the metal lines, we derive log N(H i)(cm−2) ∼21.0 ± 0.3. The DLA cloud is small (≤0.32 pc), thus not covering entirely the broad-line region and is located at ≥39 pc from the central active galactic nucleus (AGN). Although the DLA is slightly redshifted relative to the quasar, its metallicity ([S/H] = −0.41 ± 0.30) is intermediate between what is expected from infalling and outflowing gas. It could be possible that the DLA is part of some infalling material accreting on to the quasar host galaxy through filaments, and that its metallicity is raised by mixing with the enriched outflowing gas emanating from the central AGN. Current DLA surveys miss these ‘ghostly’ DLAs, and it would be important to quantify the statistics of this population by searching the Sloan Digital Sky Survey (SDSS) data base using metal absorption templates.
Shukla–Spatschek diffusion effects on surface plasma waves in astrophysical turbulent plasmas
Authors: Lee Myoung-Jae , Jung Young-Dae
Published: November 2016

The effects of Shukla–Spatschek turbulent diffusion on a temporal mode of surface waves propagating at the interface of an astrophysical turbulent plasma are investigated. The damping rates for high and low modes of surface wave are kinetically derived by employing the Vlasov–Poisson equation and the specular reflection boundary condition. We found that the diffusion caused by the fluctuating electric fields leads to damping for both high and low modes of surface waves. The high-mode damping is enhanced with an increase of the wavenumber and the diffusion coefficient, but suppressed by an increase of electron thermal energy. By contrast, the low-mode damping is suppressed as the wavenumber and the thermal energy increase although it is enhanced as the diffusion increases. The variation of the damping rate due to the Shukla–Spatschek turbulent diffusion is also discussed.
Analyses of Yield and Economic Response from Foliar Fungicide and Insecticide Applications to Soybean in the North Central United States
Authors: Kandel Yuba R. , Mueller Daren S. , Hart Chad E. , Bestor Nathan R. C. , Bradley Carl A. , Ames Keith A. , Giesler Loren J. , Wise Kiersten A.
Published: November 2016

Foliar disease and insect management on soybean (Glycine max L. Merrill) in the North Central region of the United States has been increasingly accomplished through foliar fungicide and insecticide application. Data from research trials conducted in Illinois, Indiana, Iowa, and Nebraska were compiled from 2008 to 2014 to determine the impact of fungicide, insecticide, and fungicide + insecticide applications on soybean yield and profitability. In each state, field experiments occurred each year in two to seven locations. All treatments were applied at the R3 growth stage. Disease and insect pressure were very low in all states and years. A foliar application of fungicide, insecticide, or the combination, increased yield in seven out of 14 total site-years (P < 0.10). Economic analysis using an average soybean price of $0.42 per kilogram and average application cost of $62 per hectare indicated that fungicide applications were only profitable in 14% of the trial site-years. Insecticide alone and fungicide + insecticide was profitable in 39% and 45% of site-years, respectively. Effect of fungicide class on yield was inconsistent. Our results indicate that although yield increases can occur with foliar fungicide and/or insecticide treatments, current market prices and application costs may limit profitability when disease and/or insect pressure is low.

Accepted for publication 22 September 2016.
Identifying Soybean Rust-resistant and Susceptible Populations of Kudzu to Increase Disease Monitoring Efficiency in Alabama
Authors: Sikora Edward J. , Delaney Mary A.
Published: November 2016

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is considered to be one of the most damaging diseases of soybean worldwide. Monitoring for the disease in Alabama relies heavily on scouting kudzu on a biweekly basis in south and central portions of the state from late January through the end of July in areas where soybean production is minimal and is critical to help growers avoid significant yield losses from SBR. Previous studies have reported that some kudzu populations are naturally resistant or immune to infection from the pathogen which can complicate early disease detection. This study will apply that knowledge to determine locations of kudzu populations that are either resistant or susceptible to P. pachyrhizi in order to increase monitoring efficiency and reduce costs associated with the scouting program. Results show that approximately 34% of the 162 kudzu sites tested in Alabama were resistant to P. pachyrhizi. By focusing scouting efforts on SBR-susceptible kudzu sites, we will reduce costs associated with the monitoring program by approximately 25% which is critical at a time when funding for such efforts is decreasing.

Accepted for publication 24 October 2016.
Quality Assessment of the Commercially Available Predator Amblyseius swirskii (Acari: Phytoseiidae)
Authors: Lopez Lorena , Smith Hugh A.
Published: November 2016

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is a commercially available predatory mite used to control thrips, whiteflies, and broad mites in horticultural production. The inconsistent quality of mass-produced biocontrol agents is a major concern in augmentative biological control and only a few studies have tested the post-shipment quality of commercial phytoseiids. We evaluated the post-shipment quality of A. swirskii purchased from a commercial provider in the United States. Guidelines for quality control of commercially produced natural enemies, established by the International Organization for Biological Control (IOBC), were followed. Quantity, survival, fecundity, and establishment in ornamenttal peppers (‘Explosive Ember’) were measured. The estimated quantity of A. swirskii motiles (immatures and adults) was quite variable among bran containers (20,968 ± 7,391 mites) but close to the number claimed in the label. Numbers of living A. swirskii females evaluated (n = 30) declined by less than 40% (26 ± 1.25 females) within two days of arrival and declined more than 50% by day eight (15 ± 1.23 females). No significant differences among days sampled were identified for female fecundity; however, fecundity varied considerably among containers. There was no population increase in the ornamental peppers during the two weeks following inoculation with A. swirskii.

Accepted for publication 3 September 2016.
The Development of an Indigenous Health Curriculum for Medical Students
Authors: Lewis Melissa , Prunuske Amy
Published: November 2016

Indigenous populations experience dramatic health disparities; yet, few medical schools equip students with the skills to address these inequities. At the University of Minnesota Medical School, Duluth campus, a project to develop an Indigenous health curriculum began in September 2013. This project used collaborative and decolonizing methods to gather ideas and opinions from multiple stakeholders, including students, community members, faculty, and administration, to guide the process of adding Indigenous health content to the curriculum to prepare students to work effectively with Indigenous populations. A mixed-methods needs assessment was implemented to inform the instructional design of the curriculum. In June 2014, stakeholders were invited to attend a retreat and complete a survey to understand their opinions of what should be included in the curriculum and in what way. Retreat feedback and survey responses indicated that the most important topics to include were cultural humility, Indigenous culture, social/political/economic determinants of health, and successful tribal health interventions. Stakeholders also emphasized that this content should be taught by tribal members, medical school faculty, and faculty in complementary departments (e.g., American Indian Studies, Education, Social Work) in a way that incorporates experiential learning.

Preliminary outcomes include the addition of a seven-hour block of Indigenous content for first-year students taught primarily by Indigenous faculty from several departments. To address the systemic barriers to health and well-being and provider bias that Indigenous patients experience, this project sought to gather data and opinions regarding the training of medical students through a process of Indigenizing research and education.
The Correlation Between Recordable MEPs and Motor Function During Spinal Surgery for Resection of Thoracic Spinal Cord Tumor
Authors: Guo LanJun , Li Yan , Han Ruquan , Gelb Adrian W.
Published: November 2016

Background:

Motor evoked potentials (MEPs) are commonly used during surgery for spinal cord tumor resection. However, it can be difficult to record reliable MEPs from the muscles of the lower extremities during surgery in patients with preoperative weakness due to spinal cord compression. In this study, motor function of patients’ lower extremities and their association with intraoperative MEP recording were compared.

Patients and Methods:

Patients undergoing thoracic spinal cord tumor resection were studied. Patients’ motor function was checked immediately before the surgical procedure. MEP responses were recorded from the tibialis anterior and foot muscles, and the hand muscles were used as control. Electrical current with train of eight pulses, 200 to 500 V was delivered through 2 corkscrews placed at C3’ and C4’ sites. Anesthesia was maintained by total intravenous anesthesia using a combination of propofol and remifentanil after induction with intravenous propofol, remifentanil, and rocuronium. Rocuronium was not repeated. Bispectral Index was maintained between 40 to 50.

Results:

From 178 lower limbs of 89 patients, myogenic MEPs could be recorded from 100% (105/105) of the patients with 5 of 5 motor strength in lower extremity; 90% (36/40) from the patients with 4/5 motor strength; only 25% (5/20) with 3/5; and 12.5% (1/8) with 2/5 motor strength; none (0/5) were able to be recorded if the motor strength was 1/5.

The ability to record myogenic MEPs is closely associated with the patient’s motor function. They are difficult to obtain if motor function is 3/5 motor strength in the lower extremity. They are almost impossible to record if motor function is worse than 3/5.
Which Technique Is Better Option for C3 Segment in Multilevel Open-Door Laminoplasty of the Cervical Spine?
Authors: Lee Gun Woo , Cho Chang Woo , Shin Ji-Hoon , Ahn Myun-Whan
Published: November 2016

Study Design.

A post-hoc comparative study.

Objective.

To evaluate postoperative clinical, radiological, and surgical outcomes after laminoplasty (LP) involving the C3 segment and to compare outcomes with those of patients who underwent LP with C3 laminectomy (LN).

Summary of Background Data.

In many of the pathologies that require LP involving C3 segment, most spine surgeons perform LP at C3 and other cervical segments. Considering the peculiarities of the C2-C3 level, spine surgeons should take into account those in LP involving the C3 segment, but the particular aspects of the C2-C3 levels have not been fully evaluated.

Methods.

Of 93 patients, 66 patients (39 in group A, LP involving C3; 27 in group B, LP with C3 LN) were enrolled in the study. The primary outcome measure was pain intensity of the posterior neck measured with visual analog scale. Secondary endpoints included the following: (1) radiologic outcomes based on the cervical range of motion and rate of bony impingement and spontaneous fusion between C2 and C3, (2) clinical outcomes based on the 12-item short-form health survey and Japanese Orthopedic Association scale, and (3) surgical outcomes.

Results.

The primary end-point of the present study, posterior neck pain, exhibited a greater improvement in the group with C3 LN than in the group with C3 LP at 6 months and 1 year after surgery (P = 0.03 and 0.01, respectively). The cervical range of motion of C3 LN group was significantly greater than C3 LP group at postoperative 1 year (P = 0.02). Radiologic evidences of bony impingement and spontaneous fusion between C2 and C3 were significantly greater in C3 LP group than in C3 LN group. Clinical outcomes and surgical outcomes did not differ significantly between groups.

Conclusion.

We recommend performing LN instead of LP for the C3 segment in cases requiring multilevel LP surgery involving C3.

Level of Evidence: 3