bluuebunny/crossref_metadata_2025 huggingface dataset:
Common Bermudagrass (Cynodon dactylon) Competition in Cotton (Gossypium hirsutum)
Authors: Brown Steven M. , Whitwell Ted , Street Joe E.
Published: February 2018

Experiments were conducted to evaluate effects of various densities of bermudagrass [Cynodon dactylon(L.) Pers. ♯ CYNDA] in cotton (Gossypium hirsutumL. ‘Stoneville 213’) during the initial and second seasons following grass establishment and to evaluate bermudagrass competition in three cotton row spacings. During the season of grass establishment, densities of 1 to 16 plugs/7.5 m of cotton row had minimal effects on yield. Established, perennated bermudagrass was much more competitive. During second-season competition, 1 plug/7.5 m had formed a 76% ground cover and reduced yields by 600 kg/ha (25%) or more. The highest densities reduced yields 60 to 80%. In separate experiments, a cotton row spacing of 0.5 m reduced bermudagrass ground cover compared to 1.5 m row spacing.
Weed Control and Revegetation Following Western Juniper (Juniperus occidentalis) Control
Authors: Young James A. , Evans Raymond A. , Rimbey Carl
Published: February 2018

The control of western juniper (Juniperus occidentalisHook.) trees released shrub and herbaceous vegetation from dominance of the tree overstory. Revegetation of the woodland with desirable browse and forage species required weed control of both shrub and herbaceous species. The method of tree control (herbicidal, mechanical, or wood harvesting) influenced subsequent weed control-revegetation options in the understory. Physical restraints imposed by standing dead trees resulting from picloram (4-amino-3,5,6-trichloropicolinic acid) treatment limited the use of weed control and seeding equipment. Accumulation of litter interfered with the use of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] for annual grass control on both the picloram and wood harvest plots. Establishment of forage species was most successful on the mechanically cleared plots. Attempts to revegetate with browse species were largely foiled by native herbivores, and selective predation occurred on herbaceous species.
Parametric excitation of surface plasma waves over a metallic surface by laser in an external magnetic field
Authors: Chauhan Prashant , Goel Deepika , Varshney Anshu , Singh D. B. , Sajal Vivek
Published: February 2018

Effects of external static magnetic field (applied in$\hat y$-direction) on resonant excitation of surface plasma waves (SPW) have been investigated over the metal free space interface. The high power laser$({\rm \omega} _0,\;\vec k_{0z})$is incident over the metal surface and exerts a ponderomotive force on the metal electrons in the skin layer. The ponderomotive force disturbs the quasi-neutrality of plasma which results into the excitation of space charge field at the frequency 2ω0. The electron density perturbation at frequency 2ω0driven by self-consistent space charge potential couples with the oscillatory velocity due to the seed SPW$({\rm \omega}, \;\vec k_z)$and produces nonlinear current to drive another counter propagating SPW$({\rm \omega} _1,\;\vec k_{1z})$at the phase matching conditions of frequency ω = ω1− 2ω0and wavenumber$\vec k_z = \vec k_{1z} - 2\vec k{}_{0z}$(by feedback mechanism). The parametric process becomes resonant at 2ω0≈ ωpand the maximum growth rate is achieved for an incidence angle of laser θ = 40°. The growth rate of the process reduces to half on increasing the magnetic field from 0.49 to 2.45 MG. The present study may be significant to the laser absorption experiments where surface rippling can strongly affect the laser energy absorption.
Direction/Distance/Velocity Measurements Deeply Integrated Navigation for Venus Capture Period
Authors: Liu Jin , Ning Xiao-lin , Ma Xin , Fang Jian-cheng , Liu Gang
Published: February 2018

In the Venus capture period, it is difficult for celestial autonomous navigation to satisfy the requirement of high precision. To improve autonomous navigation performance, a Direction, Distance and Velocity (DDV) measurements deeply integrated navigation method is proposed. The “deeply” integrated navigation reflects the fact that the direction and velocity measurements suppress the Doppler effects in the pulsar signals. In the pulsar observation period, the direction and velocity measurements are utilised to compensate for Doppler effects in the pulsar signals. By these means, the residual effects can be ignored. When the direction, distance or velocity measurements are obtained, they are fused to improve the navigation performance. Simulation results demonstrate that the DDV measurements deeply integrated navigation filter converges very well, and provides highly accurate position estimation without a high quality requirement on navigation sensors.
Real-Time Precise Point Positioning Using Orbit and Clock Corrections as Quasi-Observations for Improved Detection of Faults
Authors: El-Mowafy Ahmed
Published: February 2018

Real-time Precise Point Positioning (PPP) relies on the use of accurate satellite orbit and clock corrections. If these corrections contain large errors or faults, either from the system or by meaconing, they will adversely affect positioning. Therefore, such faults have to be detected and excluded. In traditional PPP, measurements that have faulty corrections are typically excluded as they are merged together. In this contribution, a new PPP model that encompasses the orbit and clock corrections as quasi-observations is presented such that they undergo the fault detection and exclusion process separate from the observations. This enables the use of measurements that have faulty corrections along with predicted values of these corrections in place of the excluded ones. Moreover, the proposed approach allows for inclusion of the complete stochastic information of the corrections. To facilitate modelling of the orbit and clock corrections as quasi-observations, International Global Navigation Satellite System Service (IGS) real-time corrections were characterised over a six-month period. The proposed method is validated and its benefits are demonstrated at two sites using three days of data.
Herbicides for Reduced Tillage Production in Peanut (Arachis hypogaea) in the Southwest
Authors: Grichar W. James , Colburn A. Edwin , Kearney Noble S.
Published: February 2018

Field studies were conducted in 1988 and 1989 under dryland and irrigated conditions to determine effects of various herbicides for use in peanuts on weed control and peanut yield under a reduced tillage system. Under dryland and irrigated conditions, sethoxydim + acifluorfen consistently controlled Texas panicum. Paraquat + bentazon controlled Texas panicum poorly under dryland conditions. Pendimethalin + metolachlor provided ≥ 80% Texas panicum control under irrigated conditions.
Photosynthesis and Transpiration Response of Redroot Pigweed (Amaranthus retroflexus)
Authors: Nielsen David C. , Anderson Randy L.
Published: February 2018

Redroot pigweed is a major weed worldwide. Increasing emphasis on modeling physiological processes of weeds for use in weed control decision support systems requires a knowledge of the response of weeds to resource levels and environmental conditions. The purpose of this study was to determine functional relationships for carbon exchange rate (CER) and transpiration based on photosynthetic photon flux density (PPFD) and temperature from measurements made on field-grown redroot pigweed. Measurements were made using a portable photosynthesis system on four dates. An equation that had the form of a power function on PPFD and a quadratic polynomial on temperature was fit to the data. The equation fit the measured CER data better than the measured transpiration data. The equations should be useful in modeling the physiological processes of pigweed within crop canopies.
Percentage-Driven Government Mandates for Pesticide Reduction: The Swedish Model
Authors: Bellinder Robin R. , Gummesson Gunnar , Karlsson Christer
Published: February 2018

In 1985, the Swedish government mandated a 50% reduction in agricultural pesticide use by 1990. The reference point was based on the average of total pesticide sales (kg ai) between 1981 and 1985. The goal was to halve the risks to users and to the environment. A two-pronged approach dealing with risk and with the actual reduction in agricultural pesticide use was developed. By 1991, 215 ‘unsafe’ or less effective pesticide products were withdrawn by producers or cancelled by the National Chemical Inspectorate, leaving only 322 registered. Additionally, the government was able to report a 47% reduction in agricultural pesticide use where 64, 54, and 2% reductions occurred in insecticides, herbicides, and fungicides, respectively. However, the treated area did not decrease. Pesticide reduction was achieved largely in cereal grain production by switching from high-dose to low-dose herbicides, reducing rates of herbicides, removal of inactive isomers from racemic mixtures, cancellation of TCA for quackgrass control, increased set-aside, and improved sprayer precision. During the same 5-yr period, Scotland achieved an equivalent reduction without government intervention, indicating that the reductions were largely due to changing herbicide technology. Determining the need for similar programs must take into account: 1. initial use rates (in 1987, average total pesticide use rates in the U.S. and in Sweden were 1.8 and 1.5 kg ai/ha, respectively, and following the mandate period, Swedish use has decreased to 0.8 kg ai/ha); 2. measurement criteria; and 3. the long-term effect of reducing herbicide rates on replenishing the soil weed seed bank reserves.
Herbicide Reduction in North America: In Canada, an Opportunity for Motivation and Growth in Weed Management
Authors: Hamill Allan S. , Surgeoner Gordon A. , Roberts Wayne P.
Published: February 2018

Pesticide registration in Canada is a Federal responsibility. Authority to recommend and use a pesticide often is Provincially controlled. A survey on “the status of pesticide reduction” within the various provinces of Canada revealed that only 3 of 10 had a policy to reduce pesticide use. In Ontario is an example of a successful non-mandatory program toward the reduced use of pesticides. A coordinated effort among government, industry, and growers has resulted in increased research, education, and extension for pesticide use. Licensing for sellers and users of pesticides has been effective in assisting the reduction of active ingredient pesticide sales.
New Technologies and Approaches for Weed Management in Sustainable Agriculture Systems
Authors: Wyse Donald L.
Published: February 2018

Weed science has a long history of solving weed management problems for farmers. Over the last four decades most of the solutions to weed problems have been based on herbicide technology. Thus, most crop production systems in the United States rely heavily on herbicides as the primary method of weed management. During the last decade environmentalists, farmers, agricultural scientists, policy makers, and the general public have begun to question the long-term sustainability of conventional farming systems. The sustainability of these systems is being questioned because of environmental, social, and economic concerns caused by global competition, cost of production, soil erosion, water pollution, and concern over the quality of rural life. Weeds are the major deterrent to the development of more sustainable agriculture systems. Since weeds dictate most of the crop production practices (e.g., tillage, herbicides, cultivation, row spacing) weed scientists must become the leaders of collaborative integrated approaches to agriculture systems research. New crop production systems must be developed that are less destructive to the environment, are profitable, conserve energy, and support rural community development. The goal is to facilitate the development of ecologically based alternative methods of weed management that will support crop production systems that require less tillage and herbicide inputs. To accomplish this goal, research efforts must be radically expanded in weed/crop ecology and in the development of ecologically based technologies for weed management.
Displacement, Repetition and Repression: Die Meistersinger von Nürnberg on Stage in the Weimar Republic
Authors: Sheil Áine
Published: February 2018

Relatively little scholarly attention has been paid to the performance and reception history of Die Meistersinger von Nürnberg during the Weimar Republic (1919–33), but as this article will demonstrate, the opera played an indispensable role in the repertories of Weimar-era opera houses. Despite an evident desire on the part of some Weimar Republic directors and designers of Die Meistersinger to draw on staging innovations of the time, productions of the work from this period are characterised by scenic conservatism and repetition of familiar naturalistic imagery. This was not coincidental, I will argue, since Die Meistersinger served as a comforting rite for many opera-going members of the Weimar-era middle classes, at least some of whom felt economically or socially beleaguered in the aftermath of World War I. But no matter how secure the conservative theatrical conventions surrounding the Weimar Republic Meistersinger appeared, the repressed turmoil of the period seeped into ideas about the work, haunting the performance and reception of constructed German stability.
Homogenization of a non-stationary non-Newtonian flow in a porous medium containing a thin fissure
Authors: ANGUIANO MARÍA
Published: February 2018

We consider a non-stationary incompressible non-Newtonian Stokes system in a porous medium with characteristic size of the pores ϵ and containing a thin fissure of width ηϵ. The viscosity is supposed to obey the power law with flow index$\frac{5}{3}\leq q\leq 2$. The limit when size of the pores tends to zero gives the homogenized behaviour of the flow. We obtain three different models depending on the magnitude ηϵwith respect to ϵ: if ηϵ≪$\varepsilon^{q\over 2q-1}$the homogenized fluid flow is governed by a time-dependent non-linear Darcy law, while if ηϵ≫$\varepsilon^{q\over 2q-1}$is governed by a time-dependent non-linear Reynolds problem. In the critical case, ηϵ≈$\varepsilon^{q\over 2q-1}$, the flow is described by a time-dependent non-linear Darcy law coupled with a time-dependent non-linear Reynolds problem.
BON PRIX, PROFIT, AND CAPITAL ACCUMULATION IN QUESNAY
Authors: Menegatti Matteo
Published: February 2018

The article discusses François Quesnay’s dynamics of capital accumulation. First, we analyze the notion of bon prix to highlight the central analytical role played by profits in Quesnay’s growth dynamics. This leads us to challenge Ronald Meek’s interpretation ([1962] 2003) and to (re)propose Peter Groenewegen’s suggestion (1974 and 1983) that profits are not included in the net product for policy reasons. We also show that profits display features resembling a stable income component such as supervision wages (see Marx [1863] 1963). Second, we contest Steven Pressman’s argument (1994, pp. 143–154) that Quesnay missed the distinction between nominal and real variables by modeling how the farmers’ monetary interest (and profit) initiates the capital accumulation process (see Vaggi 1985), which over time leads to an increase of the (physical) surplus rate and thus of the net product in real terms.
INDUSTRY, IMPROVEMENT, AND INTELLECTUAL DISABILITY: FINDING THE HOPES AND FEARS OF PARENTS AND SUPERINTENDENTS AT THE PENNSYLVANIA TRAINING SCHOOL
Authors: Ruswick Brent , Simon Elliott W.
Published: February 2018

This article examines late nineteenth-century preadmission records taken at the Pennsylvania Training School in order to better understand the biographical and medical characteristics of persons seeking admission to this prominent school for the “feeble-minded.” It draws on those records to then explore how guardians and the superintendent assessed the likelihood and nature of educational improvement. A pioneering institution for the education of people with intellectual disability, the Training School, generally known as “Elwyn,” kept extensive biographical and etiological records that contain a previously untapped wealth of data. These records offer valuable insight into parents’ understanding of their children's disability, their hopes for improvement, and opinions of what would constitute a successful, productive life. The authors use the records to develop a statistical profile of the characteristics of applicants that superintendent Dr. Martin Barr would deem most likely to improve from instruction, and a similar profile for those deemed incapable of improvement. We situate our analysis of the records within the Gilded Age context of anxieties surrounding the state of public education and worker productivity in an industrial economy. In the field of disability studies, the article adds to our understanding of how superintendents constructed and applied the “medical model” of disability and its tension with the lived social experience of disability.
GeoHealth: Connecting Earth, Ocean, Climate, and Health Sciences
Authors: Sandifer Paul
Published: February 2018

AGU’s newest journal, GeoHealth, welcomes papers on a wide range of issues relating to how environmental change is affecting the health and well-being of humans and other organisms on Earth.
The Uncertain Future of the West Antarctic Ice Sheet
Authors: Hughes Terence
Published: February 2018

A recent paper in Reviews of Geophysics discusses how climate change could affect ice streams, ice sheets, ice shelves, and sea ice in Antarctica.
Concepts for Dealing with the Complexity of Weather and Climate
Authors: Straus David
Published: February 2018

A recent article in Reviews of Geophysics describes how a nonlinear approach and the concept of regimes helps our understanding.
Harassment in Astronomy and Planetary Science
Authors: Hauck II Steven
Published: February 2018

New data reveal the prevalence of gender- and race-related harassment in astronomy and planetary sciences.
Pof8 is a La-related protein and a constitutive component of telomerase in fission yeast
Authors: Páez-Moscoso Diego J. , Pan Lili , Sigauke Rutendo F. , Schroeder Morgan R. , Tang Wen , Baumann Peter
Published: February 2018

Telomerase reverse transcriptase (TERT) and the non-coding telomerase RNA subunit (TR) constitute the core of telomerase. Here we now report that the putative F-box protein Pof8 is also a constitutive component of active telomerase in fission yeast. Pof8 functions in a hierarchical assembly pathway by promoting the binding of the Lsm2-8 complex to telomerase RNA, which in turn promotes binding of the catalytic subunit. Loss of Pof8 reduces TER1 stability, causes a severe assembly defect, and results in critically short telomeres. Structure profile searches identified similarities between Pof8 and telomerase subunits from ciliated protozoa, making Pof8 next to TERT the most widely conserved telomerase subunits identified to date.
The IAP family member BRUCE regulates autophagosome–lysosome fusion
Authors: Ebner Petra , Poetsch Isabella , Deszcz Luiza , Hoffmann Thomas , Zuber Johannes , Ikeda Fumiyo
Published: February 2018

Autophagy has an important role in cellular homeostasis by degrading and recycling cytotoxic components. Ubiquitination is known to target cargoes for autophagy; however, key components of this pathway remain elusive. Here we performed an RNAi screen to uncover ubiquitin modifiers that are required for starvation-induced macroautophagy in mammalian cells. Our screen uncovered BRUCE/Apollon/Birc6, an IAP protein, as a new autophagy regulator. Depletion of BRUCE leads to defective fusion of autophagosomes and lysosomes. Mechanistically, BRUCE selectively interacts with two ATG8 members GABARAP and GABARAPL1, as well as with Syntaxin 17, which are all critical regulators of autophagosome–lysosome fusion. In addition, BRUCE colocalizes with LAMP2. Interestingly, a non-catalytic N-terminal BRUCE fragment that is sufficient to bind GABARAP/GABARAPL1 and Syntaxin 17, and to colocalize with LAMP2, rescues autolysosome formation in Bruce
−/−
cells. Thus, BRUCE promotes autolysosome formation independently of its ubiquitin-conjugating activity and is a regulator of both macroautophagy and apoptosis.
Statistical modeling of RNA structure profiling experiments enables parsimonious reconstruction of structure landscapes
Authors: Li Hua , Aviran Sharon
Published: February 2018

RNA plays key regulatory roles in diverse cellular processes, where its functionality often derives from folding into and converting between structures. Many RNAs further rely on co-existence of alternative structures, which govern their response to cellular signals. However, characterizing heterogeneous landscapes is difficult, both experimentally and computationally. Recently, structure profiling experiments have emerged as powerful and affordable structure characterization methods, which improve computational structure prediction. To date, efforts have centered on predicting one optimal structure, with much less progress made on multiple-structure prediction. Here, we report a probabilistic modeling approach that predicts a parsimonious set of co-existing structures and estimates their abundances from structure profiling data. We demonstrate robust landscape reconstruction and quantitative insights into structural dynamics by analyzing numerous data sets. This work establishes a framework for data-directed characterization of structure landscapes to aid experimentalists in performing structure-function studies.
Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma
Authors: Tzeferacos P. , Rigby A. , Bott A. F. A. , Bell A. R. , Bingham R. , Casner A. , Cattaneo F. , Churazov E. M. , Emig J. , Fiuza F. , Forest C. B. , Foster J. , Graziani C. , Katz J. , Koenig M. , Li C.-K. , Meinecke J. , Petrasso R. , Park H.-S. , Remington B. A. , Ross J. S. , Ryu D. , Ryutov D. , White T. G. , Reville B. , Miniati F. , Schekochihin A. A. , Lamb D. Q. , Froula D. H. , Gregori G.
Published: February 2018

Magnetic fields are ubiquitous in the Universe. The energy density of these fields is typically comparable to the energy density of the fluid motions of the plasma in which they are embedded, making magnetic fields essential players in the dynamics of the luminous matter. The standard theoretical model for the origin of these strong magnetic fields is through the amplification of tiny seed fields via turbulent dynamo to the level consistent with current observations. However, experimental demonstration of the turbulent dynamo mechanism has remained elusive, since it requires plasma conditions that are extremely hard to re-create in terrestrial laboratories. Here we demonstrate, using laser-produced colliding plasma flows, that turbulence is indeed capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. These results support the notion that turbulent dynamo is a viable mechanism responsible for the observed present-day magnetization.
Patterns of island change and persistence offer alternate adaptation pathways for atoll nations
Authors: Kench Paul S. , Ford Murray R. , Owen Susan D.
Published: February 2018

Sea-level rise and climatic change threaten the existence of atoll nations. Inundation and erosion are expected to render islands uninhabitable over the next century, forcing human migration. Here we present analysis of shoreline change in all 101 islands in the Pacific atoll nation of Tuvalu. Using remotely sensed data, change is analysed over the past four decades, a period when local sea level has risen at twice the global average (~3.90 ± 0.4 mm.yr−1). Results highlight a net increase in land area in Tuvalu of 73.5 ha (2.9%), despite sea-level rise, and land area increase in eight of nine atolls. Island change has lacked uniformity with 74% increasing and 27% decreasing in size. Results challenge perceptions of island loss, showing islands are dynamic features that will persist as sites for habitation over the next century, presenting alternate opportunities for adaptation that embrace the heterogeneity of island types and their dynamics.
Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation action
Authors: Mengel Matthias , Nauels Alexander , Rogelj Joeri , Schleussner Carl-Friedrich
Published: February 2018

Sea-level rise is a major consequence of climate change that will continue long after emissions of greenhouse gases have stopped. The 2015 Paris Agreement aims at reducing climate-related risks by reducing greenhouse gas emissions to net zero and limiting global-mean temperature increase. Here we quantify the effect of these constraints on global sea-level rise until 2300, including Antarctic ice-sheet instabilities. We estimate median sea-level rise between 0.7 and 1.2 m, if net-zero greenhouse gas emissions are sustained until 2300, varying with the pathway of emissions during this century. Temperature stabilization below 2 °C is insufficient to hold median sea-level rise until 2300 below 1.5 m. We find that each 5-year delay in near-term peaking of CO2 emissions increases median year 2300 sea-level rise estimates by ca. 0.2 m, and extreme sea-level rise estimates at the 95th percentile by up to 1 m. Our results underline the importance of near-term mitigation action for limiting long-term sea-level rise risks.
Leucine-rich repeat receptor-like gene screen reveals that Nicotiana RXEG1 regulates glycoside hydrolase 12 MAMP detection
Authors: Wang Yan , Xu Yuanpeng , Sun Yujing , Wang Huibin , Qi Jiaming , Wan Bowen , Ye Wenwu , Lin Yachun , Shao Yuanyuan , Dong Suomeng , Tyler Brett M. , Wang Yuanchao
Published: February 2018

Activation of innate immunity by membrane-localized receptors is conserved across eukaryotes. Plant genomes contain hundreds of such receptor-like genes and those encoding proteins with an extracellular leucine-rich repeat (LRR) domain represent the largest family. Here, we develop a high-throughput approach to study LRR receptor-like genes on a genome-wide scale. In total, 257 tobacco rattle virus-based constructs are generated to target 386 of the 403 identified LRR receptor-like genes in Nicotiana benthamiana for silencing. Using this toolkit, we identify the LRR receptor-like protein Response to XEG1 (RXEG1) that specifically recognizes the glycoside hydrolase 12 protein XEG1. RXEG1 associates with XEG1 via the LRR domain in the apoplast and forms a complex with the LRR receptor-like kinases BAK1 and SOBIR1 to transduce the XEG1-induced defense signal. Thus, this genome-wide silencing assay is demonstrated to be an efficient toolkit to pinpoint new immune receptors, which will contribute to developing durable disease resistance.
Three-dimensional structural dynamics of DNA origami Bennett linkages using individual-particle electron tomography
Authors: Lei Dongsheng , Marras Alexander E. , Liu Jianfang , Huang Chao-Min , Zhou Lifeng , Castro Carlos E. , Su Hai-Jun , Ren Gang
Published: February 2018

Scaffolded DNA origami has proven to be a powerful and efficient technique to fabricate functional nanomachines by programming the folding of a single-stranded DNA template strand into three-dimensional (3D) nanostructures, designed to be precisely motion-controlled. Although two-dimensional (2D) imaging of DNA nanomachines using transmission electron microscopy and atomic force microscopy suggested these nanomachines are dynamic in 3D, geometric analysis based on 2D imaging was insufficient to uncover the exact motion in 3D. Here we use the individual-particle electron tomography method and reconstruct 129 density maps from 129 individual DNA origami Bennett linkage mechanisms at ~ 6–14 nm resolution. The statistical analyses of these conformations lead to understanding the 3D structural dynamics of Bennett linkage mechanisms. Moreover, our effort provides experimental verification of a theoretical kinematics model of DNA origami, which can be used as feedback to improve the design and control of motion via optimized DNA sequences and routing.
Molecular-channel driven actuator with considerations for multiple configurations and color switching
Authors: Mu Jiuke , Wang Gang , Yan Hongping , Li Huayu , Wang Xuemin , Gao Enlai , Hou Chengyi , Pham Anh Thi Cam , Wu Lianjun , Zhang Qinghong , Li Yaogang , Xu Zhiping , Guo Yang , Reichmanis Elsa , Wang Hongzhi , Zhu Meifang
Published: February 2018

The ability to achieve simultaneous intrinsic deformation with fast response in commercially available materials that can safely contact skin continues to be an unresolved challenge for artificial actuating materials. Rather than using a microporous structure, here we show an ambient-driven actuator that takes advantage of inherent nanoscale molecular channels within a commercial perfluorosulfonic acid ionomer (PFSA) film, fabricated by simple solution processing to realize a rapid response, self-adaptive, and exceptionally stable actuation. Selective patterning of PFSA films on an inert soft substrate (polyethylene terephthalate film) facilitates the formation of a range of different geometries, including a 2D (two-dimensional) roll or 3D (three-dimensional) helical structure in response to vapor stimuli. Chemical modification of the surface allowed the development of a kirigami-inspired single-layer actuator for personal humidity and heat management through macroscale geometric design features, to afford a bilayer stimuli-responsive actuator with multicolor switching capability.
Cellular imaging by targeted assembly of hot-spot SERS and photoacoustic nanoprobes using split-fluorescent protein scaffolds
Authors: Köker Tuğba , Tang Nathalie , Tian Chao , Zhang Wei , Wang Xueding , Martel Richard , Pinaud Fabien
Published: February 2018

The in cellulo assembly of plasmonic nanomaterials into photo-responsive probes is of great interest for many bioimaging and nanophotonic applications but remains challenging with traditional nucleic acid scaffolds-based bottom-up methods. Here, we address this quandary using split-fluorescent protein (FP) fragments as molecular glue and switchable Raman reporters to assemble gold or silver plasmonic nanoparticles (NPs) into photonic clusters directly in live cells. When targeted to diffusing surface biomarkers in cancer cells, the NPs self-assemble into surface-enhanced Raman-scattering (SERS) nanoclusters having hot spots homogenously seeded by the reconstruction of full-length FPs. Within plasmonic hot spots, autocatalytic activation of the FP chromophore and near-field amplification of its Raman fingerprints enable selective and sensitive SERS imaging of targeted cells. This FP-driven assembly of metal colloids also yields enhanced photoacoustic signals, allowing the hybrid FP/NP nanoclusters to serve as contrast agents for multimodal SERS and photoacoustic microscopy with single-cell sensitivity.
Deficiency of a triterpene pathway results in humidity-sensitive genic male sterility in rice
Authors: Xue Zheyong , Xu Xia , Zhou Yuan , Wang Xiaoning , Zhang Yingchun , Liu Dan , Zhao Binbin , Duan Lixin , Qi Xiaoquan
Published: February 2018

In flowering plants, the pollen coat protects the released male germ cells from desiccation and damage during pollination. However, we know little about the mechanism by which the chemical composition of the pollen coat prevents dehydration of pollen grains. Here we report that deficiency of a grass conserved triterpene synthase, OsOSC12/OsPTS1, in rice leads to failure of pollen coat formation. The mutant plants are male sterile at low relative humidity (RH < 60%), but fully male fertile at high relative humidity (>80%). The lack of three major fatty acids in the pollen coat results in rapid dehydration of pollen grains. We show that applying mixtures of linolenic acid and palmitic acid or stearic acid are able to prevent over-dehydration of mutant pollen grains. We propose that humidity-sensitive genic male sterility (HGMS) could be a desirable trait for hybrid breeding in rice, wheat, maize, and other crops.
Minimising efficiency roll-off in high-brightness perovskite light-emitting diodes
Authors: Zou Wei , Li Renzhi , Zhang Shuting , Liu Yunlong , Wang Nana , Cao Yu , Miao Yanfeng , Xu Mengmeng , Guo Qiang , Di Dawei , Zhang Li , Yi Chang , Gao Feng , Friend Richard H. , Wang Jianpu , Huang Wei
Published: February 2018

Efficiency roll-off is a major issue for most types of light-emitting diodes (LEDs), and its origins remain controversial. Here we present investigations of the efficiency roll-off in perovskite LEDs based on two-dimensional layered perovskites. By simultaneously measuring electroluminescence and photoluminescence on a working device, supported by transient photoluminescence decay measurements, we conclude that the efficiency roll-off in perovskite LEDs is mainly due to luminescence quenching which is likely caused by non-radiative Auger recombination. This detrimental effect can be suppressed by increasing the width of quantum wells, which can be easily realized in the layered perovskites by tuning the ratio of large and small organic cations in the precursor solution. This approach leads to the realization of a perovskite LED with a record external quantum efficiency of 12.7%, and the efficiency remains to be high, at approximately 10%, under a high current density of 500 mA cm−2.
The NSIGHT1-randomized controlled trial: rapid whole-genome sequencing for accelerated etiologic diagnosis in critically ill infants
Authors: Petrikin Josh E. , Cakici Julie A. , Clark Michelle M. , Willig Laurel K. , Sweeney Nathaly M. , Farrow Emily G. , Saunders Carol J. , Thiffault Isabelle , Miller Neil A. , Zellmer Lee , Herd Suzanne M. , Holmes Anne M. , Batalov Serge , Veeraraghavan Narayanan , Smith Laurie D. , Dimmock David P. , Leeder J. Steven , Kingsmore Stephen F.
Published: February 2018

Genetic disorders are a leading cause of morbidity and mortality in infants in neonatal and pediatric intensive care units (NICU/PICU). While genomic sequencing is useful for genetic disease diagnosis, results are usually reported too late to guide inpatient management. We performed an investigator-initiated, partially blinded, pragmatic, randomized, controlled trial to test the hypothesis that rapid whole-genome sequencing (rWGS) increased the proportion of NICU/PICU infants receiving a genetic diagnosis within 28 days. The participants were families with infants aged <4 months in a regional NICU and PICU, with illnesses of unknown etiology. The intervention was trio rWGS. Enrollment from October 2014 to June 2016, and follow-up until November 2016. Of all, 26 female infants, 37 male infants, and 2 infants of undetermined sex were randomized to receive rWGS plus standard genetic tests (n = 32, cases) or standard genetic tests alone (n = 33, controls). The study was terminated early due to loss of equipoise: 73% (24) controls received genomic sequencing as standard tests, and 15% (five) controls underwent compassionate cross-over to receive rWGS. Nevertheless, intention to treat analysis showed the rate of genetic diagnosis within 28 days of enrollment (the primary end-point) to be higher in cases (31%, 10 of 32) than controls (3%, 1 of 33; difference, 28% [95% CI, 10–46%]; p = 0.003). Among infants enrolled in the first 25 days of life, the rate of neonatal diagnosis was higher in cases (32%, 7 of 22) than controls (0%, 0 of 23; difference, 32% [95% CI, 11–53%];p = 0.004). Median age at diagnosis (25 days [range 14–90] in cases vs. 130 days [range 37–451] in controls) and median time to diagnosis (13 days [range 1–84] in cases, vs. 107 days [range 21–429] in controls) were significantly less in cases than controls (p = 0.04). In conclusion, rWGS increased the proportion of NICU/PICU infants who received timely diagnoses of genetic diseases.
Rice matrix metalloproteinase OsMMP1 plays pleiotropic roles in plant development and symplastic-apoplastic transport by modulating cellulose and callose depositions
Authors: Das Prabir Kumar , Biswas Rupam , Anjum Nazma , Das Amit Kumar , Maiti Mrinal K.
Published: February 2018

Matrix metalloproteinases (MMPs) are well-known proteolytic enzymes in animal systems and play roles in tissue differentiation, growth, and defence. Although a few plant MMPs have been reported, their exact functions in development and growth remain elusive. In this study, we characterized the promoter and coding sequence of OsMMP1, one of the putative MMP genes in rice (Oryza sativa). The OsMMP1 catalytic domain is structurally similar to human MMPs with respect to cofactor orientation as predicted by homology modeling. Bacterially expressed recombinant OsMMP1 showed protease activity with bovine serum albumin and gelatin as substrates. Analyses of transcript accumulation and promoter-reporter gene expression revealed that OsMMP1 is spatio-temporally expressed in vegetative and reproductive parts of plants. The plasma membrane-localized OsMMP1 protease affected plant development upon heterologous expression in tobacco and endogenous gene silencing in rice. Transgenic tobacco plants expressing OsMMP1 showed enhanced deposition of cellulose and callose, leading to impairment of symplastic and apoplastic translocations. Moreover, transgenic tobacco tissues exhibited tolerance to oxidative stress-inducing agent by confining the area of tissue death owing to callose lining. Collectively, these findings demonstrate the involvement of a plant MMP in growth, organ differentiation, and development in relation to cell wall modification.
Altered DNA methylation indicates an oscillatory flow mediated epithelial-to-mesenchymal transition signature in ascending aorta of patients with bicuspid aortic valve
Authors: Björck Hanna M. , Du Lei , Pulignani Silvia , Paloschi Valentina , Lundströmer Karin , Kostina Alexandra S. , Österholm Cecilia , Malashicheva Anna , Kostareva Anna , Evangelista Arturo , Teixidó-Tura Gisela , Maleki Shohreh , Franco-Cereceda Anders , Eriksson Per ,   Mechanistic Interrogation of Bicuspid Aortic Valve associated Aortopathy (MIBAVA) Leducq Consortium, Dietz Harry C. , Loeys Bart , Van Laer Lut , McCallion Andrew S. , Mertens Luc , Mital Seema , Mohamed Salah A. , Andelfinger Gregor
Published: February 2018

Disturbed flow has been suggested to contribute to aneurysm susceptibility in bicuspid aortic valve (BAV) patients. Lately, flow has emerged as an important modulator of DNA methylation. Hear we combined global methylation analysis with in vitro studies of flow-sensitive methylation to identify biological processes associated with BAV-aortopathy and the potential contribution of flow. Biopsies from non-dilated and dilated ascending aortas were collected from BAV (n = 21) and tricuspid aortic valve (TAV) patients (n = 23). DNA methylation and gene expression was measured in aortic intima-media tissue samples, and in EA.hy926 and primary aortic endothelial cells (ECs) isolated from BAV and TAV exposed to oscillatory (±12 dynes/cm2) or laminar (12 dynes/cm2) flow. We show methylation changes related to epithelial-mesenchymal-transition (EMT) in the non-dilated BAV aorta, associated with oscillatory flow related to endocytosis. The results indicate that the flow-response in BAV ECs involves hypomethylation and increased expression of WNT/β-catenin genes, as opposed to an angiogenic profile in TAV ECs. The EMT-signature was exasperated in dilated BAV aortas. Aberrant EMT in BAV aortic walls could contribute to increased aneurysm susceptibility, and may be due to disturbed flow-exposure. Perturbations during the spatiotemporally related embryonic development of ascending aorta and semilunar valves can however not be excluded.
The impact of reconstructed soils following oil sands exploitation on aspen and its associated belowground microbiome
Authors: Stefani Franck , Isabel Nathalie , Morency Marie-Josée , Lamothe Manuel , Nadeau Simon , Lachance Denis , Li Edith H. Y. , Greer Charles , Yergeau Étienne , Pinno Bradley D. , Séguin Armand
Published: February 2018

The objective of this study was to investigate the impact of different soil covers used to reclaim decommissioned oil sands mining sites on the genetic diversity of aspen and their associated belowground microbiota. Aspen genotyping showed that trees mostly originated from sexual reproduction on sites reclaimed with soil covers made of upland forest floor-mineral mix (FFMM) and lowland peat-mineral mix (PMM). In contrast, most individuals in mature and burned stands sampled as benchmarks for natural disturbances originated from vegetative reproduction. Nonetheless, aspen populations in the FFMM and PMM sites were not genetically different from those in mature and burned stands. DNA metabarcoding of bacteria and fungi in root and soil samples revealed that the diversity of the belowground microbiota associated with aspen and the relative abundance of putative symbiotic taxa in PMM were significantly lower than for FFMM and naturally disturbed sites. Despite similar aspen genetic diversity between FFMM and PMM sites, trees were not associated with the same belowground microbiota. Because the soil microbiome and more specifically the mycorrhizal communities are variable both in space and time, long-term monitoring is particularly important to better understand the ecological trajectory of these novel ecosystems.
Comparative genomics reveals new single-nucleotide polymorphisms that can assist in identification of adherent-invasive Escherichia coli
Authors: Camprubí-Font Carla , Lopez-Siles Mireia , Ferrer-Guixeras Meritxell , Niubó-Carulla Laura , Abellà-Ametller Carles , Garcia-Gil Librado Jesús , Martinez-Medina Margarita
Published: February 2018

Adherent-invasive Escherichia coli (AIEC) have been involved in Crohn’s disease (CD). Currently, AIEC are identified by time-consuming techniques based on in vitro infection of cell lines to determine their ability to adhere to and invade intestinal epithelial cells as well as to survive and replicate within macrophages. Our aim was to find signature sequences that can be used to identify the AIEC pathotype. Comparative genomics was performed between three E. coli strain pairs, each pair comprised one AIEC and one non-AIEC with identical pulsotype, sequence type and virulence gene carriage. Genetic differences were further analysed in 22 AIEC and 28 non-AIEC isolated from CD patients and controls. The strain pairs showed similar genome structures, and no gene was specific to AIEC. Three single nucleotide polymorphisms displayed different nucleotide distributions between AIEC and non-AIEC, and four correlated with increased adhesion and/or invasion indices. Here, we present a classification algorithm based on the identification of three allelic variants that can predict the AIEC phenotype with 84% accuracy. Our study corroborates the absence of an AIEC-specific genetic marker distributed across all AIEC strains. Nonetheless, point mutations putatively involved in the AIEC phenotype can be used for the molecular identification of the AIEC pathotype.
Drivers of spatio-temporal changes in paddy soil pH in Jiangxi Province, China from 1980 to 2010
Authors: Guo Xi , Li Hongyi , Yu Huimin , Li Weifeng , Ye Yingcong , Biswas Asim
Published: February 2018

The spatio-temporal distribution soil pH is critical for understanding the productivity and long-term sustainability of our agri-ecosystem. This study quantified the spatio-temporal distribution of paddy soil pH in Jiangxi province, China, and the potential driver of the change between 1980 and 2010. Data from the Soil Survey Information of Jiangxi province (1980s) and Jiangxi Soil Testing and Fertilizer Recommendation study (2010s) were collected and categorized into six pH ranges from strongly-acidic to strongly-alkaline with unit pH differences. Changes were calculated from the maps developed using the Pedological Knowledge base for 1980s data (without geolocation) and geostatistical methods for the 2010s data (geolocated). An overall 0.6-unit decrease and a major shift of soil pH from weakly-acidic (54% → 18%) to acidic (35% → 74%) was observed over the province in a scattered fashion with concentration in the central part and the Poyang Lake area. About half of the area under paddy cultivation went through acidification by at least one pH unit and 7% by at least 2 pH units, while 40% of the area remained unchanged. Excessive fertilizer application and acid-rain intensity contributed to the acidification. Thus, a more knowledge-based and comprehensive fertilizer management should be adopted to make paddy production sustainable in the province.
African ancestry of New World, Bemisia tabaci-whitefly species
Authors: Mugerwa Habibu , Seal Susan , Wang Hua-Ling , Patel Mitulkumar V. , Kabaalu Richard , Omongo Christopher A. , Alicai Titus , Tairo Fred , Ndunguru Joseph , Sseruwagi Peter , Colvin John
Published: February 2018

Bemisia tabaci whitefly species are some of the world’s most devastating agricultural pests and plant-virus disease vectors. Elucidation of the phylogenetic relationships in the group is the basis for understanding their evolution, biogeography, gene-functions and development of novel control technologies. We report here the discovery of five new Sub-Saharan Africa (SSA) B. tabaci putative species, using the partial mitochondrial cytochrome oxidase 1 gene: SSA9, SSA10, SSA11, SSA12 and SSA13. Two of them, SSA10 and SSA11 clustered with the New World species and shared 84.8‒86.5% sequence identities. SSA10 and SSA11 provide new evidence for a close evolutionary link between the Old and New World species. Re-analysis of the evolutionary history of B. tabaci species group indicates that the new African species (SSA10 and SSA11) diverged from the New World clade c. 25 million years ago. The new putative species enable us to: (i) re-evaluate current models of B. tabaci evolution, (ii) recognise increased diversity within this cryptic species group and (iii) re-estimate divergence dates in evolutionary time.
Open-Label Placebo Treatment for Cancer-Related Fatigue: A Randomized-Controlled Clinical Trial
Authors: Hoenemeyer Teri W. , Kaptchuk Ted J. , Mehta Tapan S. , Fontaine Kevin R.
Published: February 2018

The purpose of this 21-day assessor blinded, randomized-controlled trial was to compare an open-label placebo (OLP) to treatment as usual (TAU) for cancer survivors with fatigue. This was followed by an exploratory 21-day study in which TAU participants received OLPs while OLP participants in the main study were followed after discontinuing placebos. Cancer survivors (N = 74) who completed cancer treatment 6 months to 10 years prior to enrollment reporting at least moderate fatigue (i.e., ≥4 on a 0–10 scale) were randomized to OLP or TAU. Those randomized to OLP took 2 placebo pills twice a day for 21 days. Compared to those randomized to TAU, OLP participants reported a 29% improvement in fatigue severity (average difference in the mean change scores (MD) 12.47, 95% CI 3.32, 21.61; P = 0.008), medium effect (d = 0.63), and a 39% improvement in fatigue-disrupted quality of life (MD = 11.76, 95% CI 4.65, 18.86; P = 0.002), a large effect (d = 0.76). TAU participants who elected to try OLP for 21-days after the main study reported reductions in fatigue of a similar magnitude for fatigue severity and fatigue-disrupted quality of life (23% and 35%, respectively). OLP may reduce fatigue symptom severity and fatigue-related quality of life disruption in cancer survivors.