bluuebunny/crossref_metadata_2025 huggingface dataset:
Encapsulation of dihydrogenphosphate ions as a cyclic dimer to the cavities of site-specifically modified indolocarbazole-pyridine foldamers
Authors: Lee Chaeeun , Lee Hyemi , Lee Seungwon , Jeon Hae-Geun , Jeong Kyu-Sung
Published: December 2018

Site-specifically modified aromatic foldamers can encapsulate dihydrogen phosphate ions as a cyclic dimer via the formation of twelve hydrogen bonds.
RAFT copolymerization of oppositely charged monomers and its use to tailor the composition of nonfouling polyampholytes with an UCST behaviour
Authors: Sponchioni Mattia , Capasso Palmiero Umberto , Manfredini Nicolò , Moscatelli Davide
Published: December 2018

The RAFT copolymerization of oppositely-charged monomers is studied to optimize the composition of polyampholytes with an UCST behaviour and nonfouling properties.
Femtosecond laser-induced scratch ablation as an efficient new method to evaluate the self-healing behavior of supramolecular polymers
Authors: Abend Marcus , Kunz Clemens , Stumpf Steffi , Gräf Stephan , Zechel Stefan , Müller Frank A. , Hager Martin D. , Schubert Ulrich S.
Published: December 2018

A supramolecular self-healing metallopolymer was ablated with a femtosecond laser to realize reproducible scratches. These are studied using 3D-profilometry in combination with scratch testing experiments. Healing efficiencies are determined..
Atomic Fe hetero-layered coordination between g-C3N4 and graphene nanomeshes enhances the ORR electrocatalytic performance of zinc–air batteries
Authors: Wang Congwei , Zhao Huifang , Wang Jie , Zhao Zheng , Cheng Miao , Duan Xiaoyong , Zhang Qin , Wang Junying , Wang Junzhong
Published: December 2018

Hetero-layered iron–nitrogen coordination between g-C3N4 and graphene nanomeshes was developed for superior electrocatalytic activity in the oxygen reduction reaction.
A flexible pressure sensor based on an MXene–textile network structure
Authors: Li Tongkuai , Chen Longlong , Yang Xiang , Chen Xin , Zhang Zhihan , Zhao Tingting , Li Xifeng , Zhang Jianhua
Published: December 2018

High-performance pressure sensors have attracted considerable attention recently due to their promising applications in touch displays, wearable electronics, human–machine interfaces, and real-time physiological signal perception.
Broadband near-infrared persistent luminescence of Ba[Mg2Al2N4] with Eu2+ and Tm3+ after red light charging
Authors: Ueda Jumpei , Leaño Julius L. , Richard Cyrille , Asami Kazuki , Tanabe Setsuhisa , Liu Ru-Shi
Published: December 2018

A near infrared (NIR) persistent luminescent Ba[Mg2Al2N4]:Eu2+–Tm3+ phosphor chargeable by red light was prepared via a solid state reaction from all-nitride starting materials.
Fermi bubbles from stochastic acceleration of electrons in a Galactic outflow
Authors: Mertsch P. , Petrosian V.
Published: December 2018

The discovery of the Fermi bubbles – a huge bilobular structure seen in GeV gamma-rays above and below the Galactic centre – implies the presence of a large reservoir of high energy particles at ~10 kpc from the disk. The absence of evidence for a strong shock coinciding with the edge of the bubbles, and constraints from multi-wavelength observations point towards stochastic acceleration by turbulence as a likely mechanism of acceleration. We have investigated the time-dependent acceleration of electrons in a large-scale outflow from the Galactic centre. For the first time, we present a detailed numerical solution of the particle kinetic equation that includes the acceleration, transport and relevant energy loss processes. We also take into account the addition of shock acceleration of electrons at the bubble’s blast wave. Fitting to the observed spectrum and surface brightness distribution of the bubbles allows determining the transport coefficients, thereby shedding light on the origin of the Fermi bubbles.
Detecting the signatures of helium in type Iax supernovae
Authors: Magee M. R. , Sim S. A. , Kotak R. , Maguire K. , Boyle A.
Published: December 2018

Recent studies have argued that the progenitor system of type Iax supernovae must consist of a carbon-oxygen white dwarf accreting from a helium star companion. Based on existing explosion models invoking the pure deflagration of carbon-oxygen white dwarfs, we investigate the likelihood of producing spectral features due to helium in type Iax supernovae. From this scenario, we select those explosion models producing ejecta and 56Ni masses that are broadly consistent with those estimated for type Iax supernovae (0.014–0.478 M⊙ and ∼0.003–0.183 M⊙, respectively). To this end, we present a series of models of varying luminosities (−18.4 ≲ MV ≲ −14.5 mag) with helium abundances accounting for up to ∼36% of the ejecta mass, and covering a range of epochs beginning a few days before B-band maximum to approximately two weeks after maximum. We find that the best opportunity for detecting He I features is at near-infrared wavelengths, and in the post-maximum spectra of the fainter members of this class. We show that the optical spectrum of SN 2007J is potentially consistent with a large helium content (a few 10−2 M⊙), but argue that current models of accretion and material stripping from a companion struggle to produce compatible scenarios. We also investigate the presence of helium in all objects with near-infrared spectra. We show that SNe 2005hk, 2012Z, and 2015H contain either no helium or their helium abundances are constrained to much lower values (≲10−3 M⊙). For the faint type Iax supernova, SN 2010ae, we tentatively identify a small helium abundance from its near-infrared spectrum. Our results demonstrate the differences in helium content among type Iax supernovae, perhaps pointing to different progenitor channels. Either SN 2007J is an outlier in terms of its progenitor system, or it is not a true member of the type Iax supernova class.
Kinetic modeling of the electromagnetic precursor from an axisymmetric binary pulsar coalescence
Authors: Crinquand B. , Cerutti B. , Dubus G.
Published: December 2018

Context. The recent detection of gravitational waves associated with a binary neutron star merger revives interest in interacting pulsar magnetospheres. Current models predict that a significant amount of magnetic energy should be released prior to the merger, leading to electromagnetic precursor emission.

Aims. In this paper, we revisit this problem in the light of the recent progress in kinetic modeling of pulsar magnetospheres. We limit our work to the case of aligned magnetic moments and rotation axes, and thus neglect the orbital motion.

Methods. We perform global two-dimensional axisymmetric particle-in-cell simulations of two pulsar magnetospheres merging at a rate consistent with the emission of gravitational waves. Both symmetric and asymmetric systems are investigated.

Results. Simulations show a significant enhancement of magnetic dissipation within the magnetospheres as the two stars approach one another. Even though the magnetospheric configuration depends on the relative orientations of the pulsar spins and magnetic axes, all configurations present nearly the same radiative signature, indicating that a common dissipation mechanism is at work. The relative motion of both pulsars drives magnetic reconnection at the boundary between the two magnetospheres, leading to efficient particle acceleration and high-energy synchrotron emission. Polar-cap discharge is also strongly enhanced in asymmetric configurations, resulting in vigorous pair production and potentially additional high-energy radiation.

Conclusions. We observe an increase in the pulsar radiative efficiency by two orders of magnitude over the last orbit before the merger, exceeding the spindown power of an isolated pulsar. The expected signal is too weak to be detected at high energies even in the nearby universe. However, if a small fraction of this energy is channeled into radio waves, it could be observed as a non-repeating fast radio burst.
Traumatic Unilateral Sixth to Seventh Cervical Vertebral Facet Luxation in a Dog
Authors: Karli Philemon , Bass Martin , Inauen Roman , Bass Danielle
Published: December 2018

We describe the surgical reduction of a traumatic, unilateral cervical vertebral facet joint luxation in a large breed dog. Computed tomography (CT) including CT myelography revealed complete luxation of the left articular processes C6 to C7 without fracture of the main weight-bearing structures. There was marked spinal cord compression secondary to the malalignment. Due to the non-ambulatory tetraparetic status, open reduction was chosen as the treatment of choice. After making a dorsal surgical approach to the caudal cervical spine, the luxated articular processes were visible and repositioned. Owing to marked mobility of this joint, temporary stabilization with a nonabsorbable suture between the spinous processes of C6 and C7 was performed and good stability was obtained. The dog recovered uneventfully from the surgery and regained normal ambulation. Follow-up examination including a second CT 9 months after surgery showed no neurological abnormalities and unrestricted motion of the neck. Normal cervical vertebral alignment with moderate osteoarthritis of the right facet joint and mild spondylosis deformans C6 to C7 were present. The present case report shows successful management of a traumatic cervical facet joint luxation without persistent neurological deficits. Open reduction and temporary stabilization with suture material seem to be a valuable method of treatment. The dorsal approach allowed direct inspection of the facet joints with concurrent access to place suture material for temporary stabilization.
Selective area growth of AlGaN nanopyramid arrays on graphene by metal-organic vapor phase epitaxy
Authors: Munshi A. Mazid , Kim Dong-Chul , Heimdal Carl Philip , Heilmann Martin , Christiansen Silke H. , Vullum Per Erik , van Helvoort Antonius T. J. , Weman Helge
Published: December 2018

Wide-bandgap group III-nitride semiconductors are of special interest for applications in ultraviolet light emitting diodes, photodetectors, and lasers. However, epitaxial growth of high-quality III-nitride semiconductors on conventional single-crystalline substrates is challenging due to the lattice mismatch and differences in the thermal expansion coefficients. Recently, it has been shown that graphene, a two-dimensional material, can be used as a substrate for growing high-quality III–V semiconductors via quasi-van der Waals epitaxy and overcome the named challenges. Here, we report selective area growth of AlGaN nanopyramids on hole mask patterned single-layer graphene using metal-organic vapor phase epitaxy. The nanopyramid bases have a hexagonal shape with a very high nucleation yield. After subsequent AlGaN/GaN/AlGaN overgrowth on the six 101¯1 semi-polar side facets of the nanopyramids, intense room-temperature cathodoluminescence emission is observed at 365 nm with whispering gallery-like modes. This work opens up a route for achieving III-nitride opto-electronic devices on graphene substrates in the ultraviolet region for future applications.
Photoacoustic micropipette
Authors: Miranda Christopher , Sampath Kumar Swathy , Muthuswamy Jitendran , Smith Barbara S.
Published: December 2018

Glass micropipette electrodes are commonly used to target neurons, either in vivo or in vitro. They acquire electrophysiological recordings for the purpose of developing a further understanding of the behavior of neurons at the single cell and network levels. The success rate of acquiring adequate recordings during these procedures, however, is largely limited. Here, we demonstrate how a photoacoustic micropipette (PMP) electrode is capable of providing real-time photoacoustic feedback, useful in navigation towards intended targets. The PMP is fabricated from standard pulled borosilicate glass micropipettes, coated with aluminum. Light introduced into the wall of the micropipette, parallel to the axis, travels along the entire length of the device before exiting the tip, where it can induce the photoacoustic effect.
Capillary-tube package devices for the quantitative performance evaluation of nuclear magnetic resonance spectrometers and pulse sequences
Authors: Chi Lingyu , Huang Ming , Pfaff Annalise R. , Huang Jie , Gerald Rex E. , Woelk Klaus
Published: December 2018

With the increased sensitivity of modern nuclear magnetic resonance (NMR) spectrometers, the minimum amount needed for chemical-shift referencing of NMR spectra has decreased to a point where a few microliters can be sufficient to observe a reference signal. The reduction in the amount of required reference material is the basis for the NMR Capillary-tube Package (CapPack) platform that utilizes capillary tubes with inner diameters smaller than 150 µm as NMR-tube inserts for external reference standards. It is shown how commercially available electrophoresis capillary tubes with outer diameters of 360 µm are filled with reference liquids or solutions and then permanently sealed by the arc discharge plasma of a commercially available fusion splicer normally employed for joining optical fibers. The permanently sealed capillaries can be used as external references for chemical-shift, signal-to-noise, resolution, and concentration calibration. Combining a number of permanently sealed capillaries to form CapPack devices leads to additional applications such as performance evaluation of NMR spectrometers and NMR pulse sequences. A 10-capillary-tube side-by-side Gradient CapPack device is used in combination with one or two constant gradients, produced by room-temperature shim coils, to monitor the excitation profiles of shaped pulses. One example illustrates the performance of hyperbolic secant (sech) pulses in the EXponentially Converging Eradication Pulse Train (EXCEPT) solvent suppression sequence. The excitation profile of the pulse sequence is obtained in a single gradient NMR experiment. A clustered T1 CapPack device is introduced consisting of a coaxial NMR-tube insert that holds seven capillary tubes filled with aqueous solutions of different concentrations of the paramagnetic relaxation agent copper(ii) sulfate (CuSO4). The different CuSO4 concentrations lead to spin-lattice relaxation times in the seven capillary tubes that cover a range which extends to more than an order of magnitude. Clustered T1 CapPack devices are best suited to quantify the effects that relaxation has on magnetizations and coherences during the execution of NMR experiments, which is demonstrated for the order-of-magnitude T1 insensitivity of signal suppression with EXCEPT.
Size-controlled, high optical quality ZnO nanowires grown using colloidal Au nanoparticles and ultra-small cluster catalysts
Authors: Lynam M. F. , Ke N.-J. , Bradley S. J. , Nann T. , Neiman A. , Reeves R. J. , Downard A. J. , Golovko V. B. , Allen M. W.
Published: December 2018

Size-controlled ZnO nanowires were grown by eclipse pulsed laser deposition using Au colloids and ultra-small (sub 2 nm) Au101 and Au9 clusters as catalysts, tethered to c-plane sapphire substrates using aminopropyltrimethoxysilane (APTMS). A strong correlation was observed between ZnO nanowire tip diameter and Au catalyst size, with no apparent lower limit to the size of Au nanoparticles able to catalyze nanowire growth. All ZnO nanowires produced intense ultraviolet photoluminescence with almost no visible defect band emission that is commonly observed in ZnO-based materials, including nanowires. A correlation was also observed between the quality of the ultraviolet photoluminescence (in terms of decreasing exciton line widths and surface-related emission) and decreasing ZnO nanowire diameter, with the highest quality emission obtained using Au9 atomically precise cluster catalysts, used here as catalysts for ZnO growth for the first time.
Modeling of Globus-M2 spherical tokamak edge with nitrogen seeding
Authors: Sorokina D. S. , Senichenkov I. Yu. , Rozhansky V. A. , Vekshina E. O.
Published: December 2018

The reduction of heat fluxes to the tokamak divertor targets is a crucial problem of future thermonuclear devices, such as ITER and DEMO. According to the present understanding of the Scrape-Off Layer physics, such devices should operate in a detached divertor regime, when most of the exhaust power coming to a divertor region is dissipated by radiation. Recent experiments using ASDEX Upgrade (AUG), JET, and other tokamaks demonstrated that the transition to the detachment may be achieved by the intensive puff of radiative impurities. Spherical tokamaks can give a contribution to the understanding of mechanisms, which defines the impurity circulation in the tokamak volume. A fusion neutron source for a hybrid fusion–fission reactor is considered to be based on a spherical tokamak, and in a steady state, it can face the problem of critical heat loads. Simple estimates of power fluxes to the divertor of the Globus-M2 tokamak (which is an upgraded Globus-M tokamak) result in that they will exceed the limit of 10 MW/m2 at both inner and outer divertor targets, so the impurity seeding might be required. In the present paper, the modeling of different regimes of the Globus-M2 tokamak is performed by the SOLPS-ITER code with varying nitrogen seeding rates. It is demonstrated that with a seeding rate almost equal to the deuterium puff (as measured in electrons/s), a significant reduction of the peak power density at the outer target plate may be achieved, while the inner target plate goes to a detachment with a formation of High Field Side High Density. This result is similar to what is observed in the experiments using ASDEX Upgrade. However, in contrast to AUG, further increasing the seeding rate leads to a radiative collapse rather than to a formation of the radiative spot near the X-point. This is caused by a smaller machine size, which allows the impurity neutrals to penetrate easier into the confined region.
Two-way detection of image features and immunolabeling of lymphoma cells with one-step microarray analysis
Authors: Yang Yu , Zhao Meng , Liu Xiaodan , Ge Peng , Zheng Fang , Chen Tao , Sun Xuguo
Published: December 2018

Detecting the number of pathological lymphoma cells and lymphocyte subtypes in blood is helpful for clinical diagnosis and typing of lymphoma. In the current study, cell type is identified by cell morphological features and immunolabeled lymphocyte subtypes. Red blood cells and leukocytes were separated using a microfluidic cell chip based on physical blood cell parameters, and leukocytes were identified using five characteristic parameters: energy variance, entropy variance, moment of inertia variance, color mean, and cell area individually. The number of red blood cells that could come into contact with the leukocyte membrane was ≤2 based on the microfluidic injection flow rate of microfluidic chips. Anti-CD3 and anti-CD19 antibodies were used for immunofluorescence staining of T-lymphocyte and B-lymphocyte surface antigens, respectively. The results suggested that the microfluidic assay could detect lymphocyte surface antigen markers and intact leukocytes. Therefore, we report a one-step microfluidic chip for classifying hematological lymphoma cells based on the physical parameters of cells, which can simultaneously measure the overall morphology of blood cells and immunolabeling of lymphocyte surface antigens in one step, solving the current problem of detecting subtypes of hematological lymphoma cells based on multiple methods and multi-step detection.
Crop responses to subsoil manuring. I. Results in south-western Victoria from 2009 to 2012
Authors: Sale Peter W. , Gill Jaikirat S. , Peries Renick R. , Tang Caixian
Published: December 2018

Subsoil manuring is a practice that involves placing high rates of organic amendments in bands at the base of rip-lines that extend down into the subsoil to a depth of 30–40cm, in order to ameliorate poorly structured clay subsoils. The objective of this study was to determine whether the increases in crop yield from this practice, which occurred at one site in the high-rainfall zone in Victoria from 2005 to 2007, would occur at other sites and in other seasons in south-western Victoria. On-farm field experiments were therefore carried out at three sites in south-western Victoria between 2009 and 2012 to measure the yield responses to subsoil manuring. The study found that subsoil manuring with poultry litter resulted in consistent and recurring increases in estimated grain yield at these sites, with responses occurring with consecutive crops. Increases in estimated grain yield continued for 4 years, with average increases in hand-harvested yield of 3.5 t ha–1 for wheat, 1.6 t ha–1 for canola and 2.3 t ha–1 for faba beans. The estimated increases in grain yield were frequently associated with the increased extraction of deep subsoil water after anthesis. A treatment involving deep-banded nitrogen (N) and phosphorus (P) fertilisers and additional in-crop N, which matched the N and P in the poultry litter, yielded less than the full rate of subsoil manuring in seven of the eight site-years. This suggests that yield responses from subsoil manuring were not solely due to the release of N and P from the deep-banded poultry litter.
Cropping practices influence incidence of herbicide resistance in annual ryegrass (Lolium rigidum) in Australia
Authors: Broster J. C. , Pratley J. E. , Ip R. H. L. , Ang L. , Seng K. P.
Published: December 2018

Herbicide resistance is a common occurrence in southern Australia. The evolution of herbicide resistance is influenced by the selection pressure placed on the weed species controlled by that herbicide. Results from resistance screening of ~4500 annual ryegrass (Lolium rigidum Gaud.) samples were entered in a GIS database, together with several agricultural parameters used in the Australian Bureau of Statistics Agricultural Surveys. This allowed a study of the associations between mode of action of resistance, geographic distribution of resistance across southern Australia, and farming practices employed in particular regions. Cultivation was negatively associated with resistances in acetyl-CoA carboxylase (ACCase)-inhibiting cyclohexanedione and acetolactate synthase (ALS)-inhibiting herbicides. Higher proportions of wheat sown were associated with higher incidences of resistance. ACCase-inhibiting aryloxyphenoxypropionate and cyclohexanedione and ALS-inhibiting resistances were higher in those shires where soils were predominantly acidic. This study demonstrates the association between farm practice and the evolution of herbicide resistance. The analysis provides reinforcement to the principle of rotating chemical modes of action with non-chemical weed control measures to minimise the risk of herbicide resistance evolution in any farming system.
Growth traits associated with drought survival, recovery and persistence of cocksfoot (Dactylis glomerata) under prolonged drought treatments
Authors: Bakhtiari M. Abdollahi , Saeidnia F. , Majidi M. M. , Mirlohi A.
Published: December 2018

The effect of prolonged drought treatments on persistence, growth traits, drought survival and post-drought recovery was investigated in two sets of differently managed genotypes of cocksfoot (Dactylis glomerata L.). In total, 72 genotypes (two sets of 36 managed for seed and forage harvest, respectively) were evaluated for agro-morphological traits in the field during 2013–15 under normal and deficit irrigation regimes. In the fourth year (2016), irrigation was withheld in both irrigation treatments for 2 months and then plants were re-watered to investigate the effect of prolonged drought regimes on traits related to post-drought recovery. The deficit irrigation regime decreased persistence and recovery. These reductions were lower in the seed-management than the forage set, which indicates that delaying the first harvest of the seed-management treatment to maximise seed production led to lower impact of drought stress. The seed-management treatment also had lower persistence. The forage-management treatment had higher recovery under normal irrigation, whereas under deficit irrigation, the seed-management treatment had higher recovery. Association analysis showed the possibility of selecting genotypes having high values of persistence and drought tolerance. Results also showed a negative correlation between days to flowering and recovery after drought, indicating that selection for earliness may improve survivability and persistence of these plants. Superior genotypes with higher forage production and better recovery, persistence and drought tolerance may be recommended for development of synthetic cultivars.
A salivary effector enables whitefly to feed on host plants by eliciting salicylic acid-signaling pathway
Authors: Xu Hong-Xing , Qian Li-Xin , Wang Xing-Wei , Shao Ruo-Xuan , Hong Yue , Liu Shu-Sheng , Wang Xiao-Wei
Published: December 2018

Phloem-feeding insects feed on plant phloem using their stylets. While ingesting phloem sap, these insects secrete saliva to circumvent plant defenses. Previous studies have shown that, to facilitate their feeding, many phloem-feeding insects can elicit the salicylic acid- (SA-) signaling pathway and thus suppress effective jasmonic acid defenses. However, the molecular basis for the regulation of the plant's defense by phloem-feeding insects remains largely unknown. Here, we show that Bt56, a whitefly-secreted low molecular weight salivary protein, is highly expressed in the whitefly primary salivary gland and is delivered into host plants during feeding. Overexpression of the
Bt56
gene
in planta
promotes susceptibility of tobacco to the whitefly and elicits the SA-signaling pathway. In contrast, silencing the whitefly
Bt56
gene significantly decreases whitefly performance on host plants and interrupts whitefly phloem feeding with whiteflies losing the ability to activate the SA pathway. Protein-protein interaction assays show that the Bt56 protein directly interacts with a tobacco KNOTTED 1-like homeobox transcription factor that decreases whitefly performance and suppresses whitefly-induced SA accumulation. The
Bt56
orthologous genes are highly conserved but differentially expressed in different species of whiteflies. In conclusion, Bt56 is a key salivary effector that promotes whitefly performance by eliciting salicylic acid-signaling pathway.
Estimation of emigration, return migration, and transit migration between all pairs of countries
Authors: Azose Jonathan J. , Raftery Adrian E.
Published: December 2018

Significance

Despite the importance of international migration, estimates of between-country migration flows are still imprecise. Reliable record keeping of migration events is typically available only in the developed world, and the best existing methods to produce global migration flow estimates are burdened by strong assumptions. We produce estimates of migration flows between all pairs of countries at 5-year intervals, revealing patterns obscured by previous estimation methods. In particular, our estimates reveal large bidirectional movements in all global regions, with roughly one-quarter of migration events consisting of returns to an individual’s country of birth.
Decline in climate resilience of European wheat
Authors: Kahiluoto Helena , Kaseva Janne , Balek Jan , Olesen Jørgen E. , Ruiz-Ramos Margarita , Gobin Anne , Kersebaum Kurt Christian , Takáč Jozef , Ruget Francoise , Ferrise Roberto , Bezak Pavol , Capellades Gemma , Dibari Camilla , Mäkinen Hanna , Nendel Claas , Ventrella Domenico , Rodríguez Alfredo , Bindi Marco , Trnka Mirek
Published: December 2018

Significance

Food security under climate change depends on the yield performance of staple food crops. We found a decline in the climate resilience of European wheat in most countries during the last 5 to 15 y, depending on the country. The yield responses of all the cultivars to different weather events were relatively similar within northern and central Europe, within southern European countries, and specifically regarding durum wheat. We also found serious Europe-wide gaps in wheat resilience, especially regarding yield performance under abundant rain. Climate resilience is currently not receiving the attention it deserves by breeders, seed and wheat traders, and farmers. Consequently, the results provide insights into the required learning tools, economic incentives, and role of public actors.
Climate change and residential electricity consumption in the Yangtze River Delta, China
Authors: Li Yating , Pizer William A. , Wu Libo
Published: December 2018

Significance

Estimating the impacts of climate change is essential for analysis of both mitigation and adaptation policies. Our principal finding, that annual electricity consumption increases by 9.2% per +1 °C in annual global mean surface temperature (GMST) in the Yangtze River Delta, represents one of the few estimates of impacts outside Western countries. This estimate can contribute to analyses of global mitigation efforts, helping to determine what level of emissions best balances costs and benefits. We note that energy consumption is often one of the larger categories of monetized climate change impacts. We also estimate that annual peak electricity use increases by 36.1% per +1 °C in annual GMST, assisting planning efforts for additional grid capacity that will be needed in the future.
Precise timing of abrupt increase in dust activity in the Middle East coincident with 4.2 ka social change
Authors: Carolin Stacy A. , Walker Richard T. , Day Christopher C. , Ersek Vasile , Sloan R. Alastair , Dee Michael W. , Talebian Morteza , Henderson Gideon M.
Published: December 2018

Significance

A speleothem geochemical record from northern Iran captures significant climate fluctuations during the mid-to-late Holocene at high resolution. Two abrupt shifts in Mg/Ca last for more than a century and are interpreted as enhanced dust activity, indicating a threshold behavior in response to aridity. Coincident gradual peaks in δ
18
O support the interpretation of regional drying. The precise chronology shows the later event, 4.26 ka to 3.97 ka, is coincident within decades of the period of abandonment of advanced urban settlements in northern Mesopotamia, strengthening the argument for association between societal and climatic change. The record demonstrates the abrupt onset of dust production in the region and ability to maintain this dry climate state for multiple centuries naturally.
DNA damage and genome instability by G-quadruplex ligands are mediated by R loops in human cancer cells
Authors: De Magis Alessio , Manzo Stefano G. , Russo Marco , Marinello Jessica , Morigi Rita , Sordet Olivier , Capranico Giovanni
Published: December 2018

G quadruplexes (G4s) and R loops are noncanonical DNA structures that can regulate basic nuclear processes and trigger DNA damage, genome instability, and cell killing. By different technical approaches, we here establish that specific G4 ligands stabilize G4s and simultaneously increase R-loop levels within minutes in human cancer cells. Genome-wide mapping of R loops showed that the studied G4 ligands likely cause the spreading of R loops to adjacent regions containing G4 structures, preferentially at 3′-end regions of expressed genes, which are partially ligand-specific. Overexpression of an exogenous human RNaseH1 rescued DNA damage induced by G4 ligands in
BRCA2
-proficient and
BRCA2
-silenced cancer cells. Moreover, even if the studied G4 ligands increased noncanonical DNA structures at similar levels in nuclear chromatin, their cellular effects were different in relation to cell-killing activity and stimulation of micronuclei, a hallmark of genome instability. Our findings therefore establish that G4 ligands can induce DNA damage by an R loop-dependent mechanism that can eventually lead to different cellular consequences depending on the chemical nature of the ligands.
SENCRstabilizes vascular endothelial cell adherens junctions through interaction with CKAP4
Authors: Lyu Qing , Xu Suowen , Lyu Yuyan , Choi Mihyun , Christie Christine K. , Slivano Orazio J. , Rahman Arshad , Jin Zheng-Gen , Long Xiaochun , Xu Yawei , Miano Joseph M.
Published: December 2018

SENCRis a human-specific, vascular cell-enriched long-noncoding RNA (lncRNA) that regulates vascular smooth muscle cell and endothelial cell (EC) phenotypes. The underlying mechanisms of action ofSENCRin these and other cell types is unknown. Here, levels ofSENCRRNA are shown to be elevated in several differentiated human EC lineages subjected to laminar shear stress. Increases inSENCRRNA are also observed in the laminar shear stress region of the adult aorta of humanizedSENCR-expressing mice, but not in disturbed shear stress regions.SENCRloss-of-function studies disclose perturbations in EC membrane integrity resulting in increased EC permeability. Biotinylated RNA pull-down and mass spectrometry establish an abundantSENCR-binding protein, cytoskeletal-associated protein 4 (CKAP4); this ribonucleoprotein complex was further confirmed in an RNA immunoprecipitation experiment using an antibody to CKAP4. Structure–function studies demonstrate a noncanonical RNA-binding domain in CKAP4 that bindsSENCR. UponSENCRknockdown, increasing levels of CKAP4 protein are detected in the EC surface fraction. Furthermore, an interaction between CKAP4 and CDH5 is enhanced inSENCR-depleted EC. This heightened association appears to destabilize the CDH5/CTNND1 complex and augment CDH5 internalization, resulting in impaired adherens junctions. These findings supportSENCRas a flow-responsive lncRNA that promotes EC adherens junction integrity through physical association with CKAP4, thereby stabilizing cell membrane-bound CDH5.
Mitochondria modulate programmed neuritic retraction
Authors: Baranov Sergei V. , Baranova Oxana V. , Yablonska Svitlana , Suofu Yalikun , Vazquez Alberto L. , Kozai Takashi D. Y. , Cui X. Tracy , Ferrando Lisa M. , Larkin Timothy M. , Tyurina Yulia Y. , Kagan Valerian E. , Carlisle Diane L. , Kristal Bruce S. , Friedlander Robert M.
Published: December 2018

Significance

Neuritic retraction in the absence of overt neuronal death occurs during aging and early in neurodegenerative disorders. However, mechanisms responsible for physiologic and pathologic neuritic retraction are unknown. We demonstrate that progressive distal mitochondrial protein damage, resulting in impaired mitochondrial protein import in distal neuronal compartments, leads to the neurite loss-related focal caspase-3 activation. This import defect amplifies mitochondrial vulnerability by slowing incorporation of newly produced proteins, affecting mitochondrial physiology indicated by loss of membrane potential, increased reactive oxygen species production, and focal caspase-3 activation. We describe this fundamental physiologic mechanism that controls neurite plasticity/vulnerability and is further amplified during neurodegeneration as “neuritosis.” This neuronal regulatory mechanism is likely important for neurodevelopment and is exacerbated during aging and pathologically in neurodegenerative diseases.
Genetic legacy of state centralization in the Kuba Kingdom of the Democratic Republic of the Congo
Authors: van Dorp Lucy , Lowes Sara , Weigel Jonathan L. , Ansari-Pour Naser , López Saioa , Mendoza-Revilla Javier , Robinson James A. , Henrich Joseph , Thomas Mark G. , Nunn Nathan , Hellenthal Garrett
Published: December 2018

Significance

State centralization occurs when previously separate communities are united, forming a single political system often associated with economy, trade, warfare, and culture. One example is the precolonial Kuba Kingdom of the Democratic Republic of the Congo (DRC). Using genetic data from over 690 individuals from the DRC, we compared individuals whose ancestors were part of the Kingdom to individuals from other neighboring groups. We found a genetic legacy of state formation that can be explained by the joining and subsequent mixing of groups at the time of state centralization, as well as evidence of gene flow facilitated by the Kingdom’s infrastructure. We characterize the genetic history of this region and show the power of DNA to reveal information on societal systems where few written records exist.
Integration in emerging social networks explains academic failure and success
Authors: Stadtfeld Christoph , Vörös András , Elmer Timon , Boda Zsófia , Raabe Isabel J.
Published: December 2018

Significance

Understanding the factors that explain academic failure and success of university students is a core interest of educational researchers, teachers, and managers. We demonstrate how the dynamic social networks that informally evolve between students can affect their academic performance. We closely followed the emergence of multiple social networks within a cohort of 226 undergraduate university students. They were strangers to each other on their first day at university, but developed densely knit social networks through time. We show that functional studying relationships tended to evolve from informal friendship relations. In a critical examination period after one year, these networks proved to be crucial: Socially isolated students had significantly lower examination grades and were more likely to drop out of university.
Two-step pathway for isoprenoid synthesis
Authors: Chatzivasileiou Alkiviadis Orfefs , Ward Valerie , Edgar Steven McBride , Stephanopoulos Gregory
Published: December 2018

Significance

Isoprenoids are a class of natural products with applications in many fields, including medicine and agriculture. Biosynthesis of isoprenoids has emerged as the most commercially viable option for their mass production. We report the creation of an enzymatic pathway for the biological production of isoprenoids, which uses externally provided isoprenol as its substrate instead of a glucose-derived catabolite, making it radically different from naturally occurring pathways or their engineered variants. The pathway is only two steps long and uses a single cofactor, ATP. Our results show that it is decoupled from central carbon metabolism and can sustain a very high flux. These advantages make it a noteworthy alternative to known isoprenoid pathways.
Tropical forests can maintain hyperdiversity because of enemies
Authors: Levi Taal , Barfield Michael , Barrantes Shane , Sullivan Christopher , Holt Robert D. , Terborgh John
Published: December 2018

Significance

Biologists have long sought to explain how tropical forests can support as many as 1,000 tree species at a single site. Such high diversity presents a paradox in that two well-documented mechanisms, competition and drift, both erode diversity over time. Much imagination has gone into the quest to find a countervailing force of sufficient strength to counterbalance competition and drift. We show here that the 48-year-old Janzen−Connell mechanism, in which natural enemies restrict tree recruitment near conspecific adults, is capable of maintaining high levels of diversity indefinitely via a stabilizing mechanism that favors rare species and hinders common ones. Diversity maintenance requires only a small zone around conspecific adults in which saplings fail to recruit.
Epigenetic editing by CRISPR/dCas9 in
Plasmodium falciparum
Authors: Xiao Bo , Yin Shigang , Hu Yang , Sun Maoxin , Wei Jieqiong , Huang Zhenghui , Wen Yuhao , Dai Xueyu , Chen Huiling , Mu Jianbing , Cui Liwang , Jiang Lubin
Published: December 2018

Genetic manipulation remains a major obstacle for understanding the functional genomics of the deadliest malaria parasite
Plasmodium falciparum
. Although the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 9) system has been successfully applied to introduce permanent changes in the parasite genome, its use is still limited. Here we show that fusing different epigenetic effector domains to a Cas9 null mutant efficiently and specifically reprograms the expression of target genes in
P. falciparum
. By precisely writing and erasing histone acetylation at the transcription start site regions of the invasion-related genes
reticulocyte binding protein homolog 4
(
rh4
) and
erythrocyte binding protein 175
(
eba-175
), respectively, we achieved significant activation of
rh4
and repression of
eba-175
, leading to the switch of the parasite invasion pathways into human erythrocytes. By using the epigenetic knockdown system, we have also characterized the effects of
PfSET1
, previously identified as an essential gene, on expression of mainly trophozoite- and schizont-specific genes, and therefore regulation of the growth of the mature forms of
P. falciparum
. This epigenetic CRISPR/dCas9 system provides a powerful approach for regulating gene expression at the transcriptional level in
P. falciparum
.
Multiomics of azacitidine-treated AML cells reveals variable and convergent targets that remodel the cell-surface proteome
Authors: Leung Kevin K. , Nguyen Aaron , Shi Tao , Tang Lin , Ni Xiaochun , Escoubet Laure , MacBeth Kyle J. , DiMartino Jorge , Wells James A.
Published: December 2018

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are diseases of abnormal hematopoietic differentiation with aberrant epigenetic alterations. Azacitidine (AZA) is a DNA methyltransferase inhibitor widely used to treat MDS and AML, yet the impact of AZA on the cell-surface proteome has not been defined. To identify potential therapeutic targets for use in combination with AZA in AML patients, we investigated the effects of AZA treatment on four AML cell lines representing different stages of differentiation. The effect of AZA treatment on these cell lines was characterized at three levels: the DNA methylome, the transcriptome, and the cell-surface proteome. Untreated AML cell lines showed substantial overlap at all three omics levels; however, while AZA treatment globally reduced DNA methylation in all cell lines, changes in the transcriptome and surface proteome were subtle and differed among the cell lines. Transcriptome analysis identified five commonly up-regulated coding genes upon AZA treatment in all four cell lines, TRPM4 being the only gene encoding a surface protein, and surface proteome analysis found no commonly regulated proteins. Gene set enrichment analysis of differentially regulated RNA and surface proteins showed a decrease in metabolic pathways and an increase in immune defense response pathways. As such, AZA treatment led to diverse effects at the individual gene and protein levels but converged to common responses at the pathway level. Given the heterogeneous responses in the four cell lines, we discuss potential therapeutic strategies for AML in combination with AZA.
Climate shapes and shifts functional biodiversity in forests worldwide
Authors: Wieczynski Daniel J. , Boyle Brad , Buzzard Vanessa , Duran Sandra M. , Henderson Amanda N. , Hulshof Catherine M. , Kerkhoff Andrew J. , McCarthy Megan C. , Michaletz Sean T. , Swenson Nathan G. , Asner Gregory P. , Bentley Lisa Patrick , Enquist Brian J. , Savage Van M.
Published: December 2018

Much ecological research aims to explain how climate impacts biodiversity and ecosystem-level processes through functional traits that link environment with individual performance. However, the specific climatic drivers of functional diversity across space and time remain unclear due largely to limitations in the availability of paired trait and climate data. We compile and analyze a global forest dataset using a method based on abundance-weighted trait moments to assess how climate influences the shapes of whole-community trait distributions. Our approach combines abundance-weighted metrics with diverse climate factors to produce a comprehensive catalog of trait–climate relationships that differ dramatically—27% of significant results change in sign and 71% disagree on sign, significance, or both—from traditional species-weighted methods. We find that (
i
) functional diversity generally declines with increasing latitude and elevation, (
ii
) temperature variability and vapor pressure are the strongest drivers of geographic shifts in functional composition and ecological strategies, and (
iii
) functional composition may currently be shifting over time due to rapid climate warming. Our analysis demonstrates that climate strongly governs functional diversity and provides essential information needed to predict how biodiversity and ecosystem function will respond to climate change.
Mechanistic insights from plant heteromannan synthesis in yeast
Authors: Voiniciuc Cătălin , Dama Murali , Gawenda Niklas , Stritt Fabian , Pauly Markus
Published: December 2018

Significance

Heteromannans are ancient plant cell wall polysaccharides, ubiquitous throughout the plant kingdom. In plants, these hemicellulosic polymers strengthen the cell wall and facilitate energy storage, and are involved in cell expansion and developmental signaling. Heteromannans are used extensively by humans, as healthy dietary fibers and as thickening agents in food, cosmetic, pharmaceutical, and mining industries. The fine structure of heteromannan is important for the polysaccharide’s biophysical properties, and thus its function and application. However, the biosynthesis of different heteromannan structures remains mechanistically unclear. We demonstrate that plant mannan and glucomannan can be synthesized heterologously in the yeast
Pichia pastoris
, and the polysaccharide’s structure can be modulated by specific plant cofactors, allowing for the synthesis of tailored mannan structures.
Mutational landscape of primary, metastatic, and recurrent ovarian cancer reveals c-MYC gains as potential target for BET inhibitors
Authors: Li Charles , Bonazzoli Elena , Bellone Stefania , Choi Jungmin , Dong Weilai , Menderes Gulden , Altwerger Gary , Han Chanhee , Manzano Aranzazu , Bianchi Anna , Pettinella Francesca , Manara Paola , Lopez Salvatore , Yadav Ghanshyam , Riccio Francesco , Zammataro Luca , Zeybek Burak , Yang-Hartwich Yang , Buza Natalia , Hui Pei , Wong Serena , Ravaggi Antonella , Bignotti Eliana , Romani Chiara , Todeschini Paola , Zanotti Laura , Zizioli Valentina , Odicino Franco , Pecorelli Sergio , Ardighieri Laura , Silasi Dan-Arin , Litkouhi Babak , Ratner Elena , Azodi Masoud , Huang Gloria S. , Schwartz Peter E. , Lifton Richard P. , Schlessinger Joseph , Santin Alessandro D.
Published: December 2018

Significance

Ovarian cancer has the propensity for early dissemination of microscopic metastases, making early detection challenging. Development of treatments for patients with advanced/recurrent chemotherapy-resistant disease remains an unmet need. We sequenced primary, synchronous bilateral ovarian cancer (SBOC), metastatic, and recurrent ovarian tumors. We found primary and metastatic tumors to be remarkably similar and SBOC to be clonally related in all cases, suggesting early dissemination to represent an intrinsic feature of ovarian cancer. c-MYC and PIK3CA amplifications were prevalent and maintained in progression to metastasis and enriched in tumor recurrence. c-MYC amplified chemotherapy-resistant cell lines and xenografts were sensitive to JQ1 and GS-626510, suggesting Bromodomain and Extra-Terminal motif (BET) inhibitors as effective targeted agents in patients with c-MYC–amplified recurrent/chemotherapy-resistant ovarian tumors.