bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shear Flow Past a Wing of Circular Plan Form
Authors: Nigam L. N. 
Published: July 2016

The problem of flow past a thin wing of circular plan form when the undisturbed flow is along the x-axis, U(z)=Az+V has been solved.The solutions for potential flow past a wing of circular plan form have been given in terms of spheroidal co-ordinates using the concept of acceleration potential. The solutions can be easily adapted to the case when the undisturbed flow is weakly sheared. In the particular case when the undisturbed velocity U(z) = Az+V, where A and V are constants, the pressure equation can be simplified by a simple substitution and the solution for a thin wing of circular plan form can be easily constructed from the solution for potential flow. If the wings in the two cases develop the same lift, it is found that the wing in shear flow should be slightly cambered (potential wing is un-cambered). The results are shown graphically in Fig. 1.
The Optimum Size of a Rocket Engine
Authors: Dunning J. E. P. 
Published: July 2016

Summary:The paper gives a précis account of studies made at the Rocket Propulsion Establishment of the Ministry of Aviation to determine the relationship between the specific weight and thrust of a liquid bi-propellent rocket engine.Although the need for a better understanding of basic phenomena is established, the conclusion is reached that, within the selected premises, the minimum specific weight is achieved at a thrust level near 50,000 lb. The difference in specific weight between engines of 200,000 lb. thrust and 50,000 lb. thrust is only about 10 per cent and this is shown to be equivalent to only one per cent in propellent specific impulse. Although small, it is considered significant that a minimum has been established and this fact is used as an argument to justify the use of clusters of engines (generally four) to provide levels of thrust greater than 100,000 lb.
Realization of tristability in a multiplicatively coupled dual-loop genetic network
Authors: Huang Bo , Xia Yun , Liu Feng , Wang Wei 
Published: July 2016

AbstractMultistability is a crucial recurring theme in cell signaling. Multistability is attributed to the presence of positive feedback loops, but the general condition and essential mechanism for realizing multistability remain unclear. Here, we build a generic circuit model comprising two transcription factors and a microRNA, representing a kind of core architecture in gene regulatory networks. The circuit can be decomposed into two positive feedback loops (PFLs) or one PFL and one negative feedback loop (NFL), which are multiplicatively coupled. Bifurcation analyses of the model reveal that the circuit can achieve tristability through four kinds of bifurcation scenarios when parameter values are varied in a wide range. We formulate the general requirement for tristability in terms of logarithmic gain of the circuit. The parameter ranges for tristability and possible transition routes among steady states are determined by the combination of gain features of individual feedback loops. Coupling two PFLs with bistability or one NFL with a bistable PFL is most likely to generate tristability, but the underlying mechanisms are largely different. We also interpret published results and make testable predictions. This work sheds new light on interlinking feedback loops to realize tristability. The proposed theoretical framework can be of wide applicability.
Surface effects of vapour-liquid-solid driven Bi surface droplets formed during molecular-beam-epitaxy of GaAsBi
Authors: Steele J. A. , Lewis R. A. , Horvat J. , Nancarrow M. J. B. , Henini M. , Fan D. , Mazur Y. I. , Schmidbauer M. , Ware M. E. , Yu S.-Q. , Salamo G. J. 
Published: July 2016

AbstractHerein we investigate a (001)-oriented GaAs1−xBix/GaAs structure possessing Bi surface droplets capable of catalysing the formation of nanostructures during Bi-rich growth, through the vapour-liquid-solid mechanism. Specifically, self-aligned “nanotracks” are found to exist trailing the Bi droplets on the sample surface. Through cross-sectional high-resolution transmission electron microscopy the nanotracks are revealed to in fact be elevated above surface by the formation of a subsurface planar nanowire, a structure initiated mid-way through the molecular-beam-epitaxy growth and embedded into the epilayer, via epitaxial overgrowth. Electron microscopy studies also yield the morphological, structural and chemical properties of the nanostructures. Through a combination of Bi determination methods the compositional profile of the film is shown to be graded and inhomogeneous. Furthermore, the coherent and pure zincblende phase property of the film is detailed. Optical characterisation of features on the sample surface is carried out using polarised micro-Raman and micro-photoluminescence spectroscopies. The important light producing properties of the surface nanostructures are investigated through pump intensity-dependent micro-PL measurements, whereby relatively large local inhomogeneities are revealed to exist on the epitaxial surface for important optical parameters. We conclude that such surface effects must be considered when designing and fabricating optical devices based on GaAsBi alloys.
Flexible All-organic, All-solution Processed Thin Film Transistor Array with Ultrashort Channel
Authors: Xu Wei , Hu Zhanhao , Liu Huimin , Lan Linfeng , Peng Junbiao , Wang Jian , Cao Yong 
Published: July 2016

AbstractShrinking the device dimension has long been the pursuit of the semiconductor industry to increase the device density and operation speed. In the application of thin film transistors (TFTs), all-organic TFT arrays made by all-solution process are desired for low cost and flexible electronics. One of the greatest challenges is how to achieve ultrashort channel through a cost-effective method. In our study, ultrashort-channel devices are demonstrated by direct inkjet printing conducting polymer as source/drain and gate electrodes without any complicated substrate’s pre-patterning process. By modifying the substrate’s wettability, the conducting polymer’s contact line is pinned during drying process which makes the channel length well-controlled. An organic TFT array of 200 devices with 2 μm channel length is fabricated on flexible substrate through all-solution process. The simple and scalable process to fabricate high resolution organic transistor array offers a low cost approach in the development of flexible and wearable electronics.
A compact tunable polarized X-ray source based on laser-plasma helical undulators
Authors: Luo J. , Chen M. , Zeng M. , Vieira J. , Yu L. L. , Weng S. M. , Silva L. O. , Jaroszynski D. A. , Sheng Z. M. , Zhang J. 
Published: July 2016

AbstractLaser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 1019 photons/s/mm2/mrad2/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications.
Smyd5 plays pivotal roles in both primitive and definitive hematopoiesis during zebrafish embryogenesis
Authors: Fujii Tomoaki , Tsunesumi Shin-ichiro , Sagara Hiroshi , Munakata Miyo , Hisaki Yoshihiro , Sekiya Takao , Furukawa Yoichi , Sakamoto Kazuhiro , Watanabe Sumiko 
Published: July 2016

AbstractMethylation of histone tails plays a pivotal role in the regulation of a wide range of biological processes. SET and MYND domain-containing protein (SMYD) is a methyltransferase, five family members of which have been identified in humans. SMYD1, SMYD2, SMYD3 and SMYD4 have been found to play critical roles in carcinogenesis and/or the development of heart and skeletal muscle. However, the physiological functions of SMYD5 remain unknown. To investigate the function of Smyd5 in vivo, zebrafish were utilised as a model system. We first examined smyd5 expression patterns in developing zebrafish embryos. Smyd5 transcripts were abundantly expressed at early developmental stages and then gradually decreased. Smyd5 was expressed in all adult tissues examined. Loss-of-function analysis of Smyd5 was then performed in zebrafish embryos using smyd5 morpholino oligonucleotide (MO). Embryos injected with smyd5-MO showed normal gross morphological development, including of heart and skeletal muscle. However, increased expression of both primitive and definitive hematopoietic markers, including pu.1, mpx, l-plastin, and cmyb, were observed. These phenotypes of smyd5-MO zebrafish embryos were also observed when we introduced mutations in smyd5 gene with the CRISPR/Cas9 system. As the expression of myeloid markers was elevated in smyd5 loss-of-function zebrafish, we propose that Smyd5 plays critical roles in hematopoiesis.
A dinosaurian facial deformity and the first occurrence of ameloblastoma in the fossil record
Authors: Dumbravă Mihai D. , Rothschild Bruce M. , Weishampel David B. , Csiki-Sava Zoltán , Andrei Răzvan A. , Acheson Katharine A. , Codrea Vlad A. 
Published: July 2016

AbstractDespite documentation of various types of neoplastic pathologies encountered in the vertebrate fossil record, no ameloblastic tumours have been recognised so far. Ameloblastoma is a benign neoplasic tumour with a strong preponderance for the mandible. Here, we report for the first time the presence of an ameloblastoma neoplasm in the lower jaw of a specimen referred to the derived non-hadrosaurid hadrosauroid dinosaur Telmatosaurus transsylvanicus from the uppermost Cretaceous of the Ha"Equation missing"eg Basin in Romania. The location, external appearance and internal structure of the pathological outgrowth provide clear evidence for the diagnosis of ameloblastoma in Telmatosaurus. This report extends the range of pathologies encountered in hadrosauroid dinosaurs. In addition, recognition of an ameloblastoma neoplasm in a taxon lying close to the origin of ‘duck-billed’ hadrosaurid dinosaurs confirms the predisposition of this clade towards neoplasia pathologies already in its basal members.
Zinc Resistance Mechanisms of P1B-type ATPases in Sinorhizobium meliloti CCNWSX0020
Authors: Lu Mingmei , Li Zhefei , Liang Jianqiang , Wei Yibing , Rensing Christopher , Wei Gehong 
Published: July 2016

AbstractThe Sinorhizobium meliloti (S. meliloti) strain CCNWSX0020 displayed tolerance to high levels exposures of multiple metals and growth promotion of legume plants grown in metal-contaminated soil. However, the mechanism of metal-resistant strain remains unknown. We used five P1B-ATPases deletions by designating as ∆copA1b, ∆fixI1, ∆copA3, ∆zntA and ∆nia, respectively to investigate the role of P1B-ATPases in heavy metal resistance of S. meliloti. The ∆copA1b and ∆zntA mutants were sensitive to zinc (Zn), cadmium (Cd) and lead (Pb) in different degree, whereas the other mutants had no significant influence on the metal resistance. Moreover, the expression of zntA was induced by Zn, Cd and Pb whereas copA1b was induced by copper (Cu) and silver (Ag). This two deletions could led to the increased intracellular concentrations of Zn, Pb and Cd, but not of Cu. Complementation of ∆copA1b and ∆zntA mutants showed a restoration of tolerance to Zn, Cd and Pb to a certain extent. Taken together, the results suggest an important role of copA1b and zntA in Zn homeostasis and Cd and Pb detoxification in S. meliloti CCNWSX0020.
Dopamine D2/3- and μ-opioid receptor antagonists reduce cue-induced responding and reward impulsivity in humans
Authors: Weber S C , Beck-Schimmer B , Kajdi M-E , Müller D , Tobler P N , Quednow B B 
Published: July 2016

AbstractIncreased responding to drug-associated stimuli (cue reactivity) and an inability to tolerate delayed gratification (reward impulsivity) have been implicated in the development and maintenance of drug addiction. Whereas data from animal studies suggest that both the dopamine and opioid system are involved in these two reward-related processes, their role in humans is less clear. Moreover, dopaminergic and opioidergic drugs have not been directly compared with regard to these functions, even though a deeper understanding of the underlying mechanisms might inform the development of specific treatments for elevated cue reactivity and reward impulsivity. In a randomized, double-blind, between-subject design we administered the selective dopamine D2/D3 receptor antagonist amisulpride (400 mg, n=41), the unspecific opioid receptor antagonist naltrexone (50 mg, n=40) or placebo (n=40) to healthy humans and measured cue-induced responding with a Pavlovian-instrumental transfer task and reward impulsivity with a delay discounting task. Mood was assessed using a visual analogue scale. Compared with placebo, amisulpride significantly suppressed cue-induced responding and reward impulsivity. The effects of naltrexone were similar, although less pronounced. Both amisulpride and naltrexone decreased average mood ratings compared with placebo. Our results demonstrate that a selective blockade of dopamine D2/D3 receptors reduces cue-induced responding and reward impulsivity in healthy humans. Antagonizing μ-opioid receptors has similar effects for cue-induced responding and to a lesser extent for reward impulsivity.
Multi-device studies of pedestal physics and confinement in the I-mode regime
Authors: Hubbard A.E. , Osborne T. , Ryter F. , Austin M. , Barrera Orte L. , Churchill R.M. , Cziegler I. , Fenstermacher M. , Fischer R. , Gerhardt S. , Groebner R. , Gohil P. , Happel T. , Hughes J.W. , Loarte A. , Maingi R. , Manz P. , Marinoni A. , Marmar E.S. , McDermott R.M. , McKee G. , Rhodes T.L. , Rice J.E. , Schmitz L. , Theiler C. , Viezzer E. , Walk J.R. , White A. , Whyte D. , Wolfe S. , Wolfrum E. , Yan Z. 
Published: July 2016

Abstract
This paper describes joint ITPA studies of the I-mode regime, which features an edge thermal barrier together with L-mode-like particle and impurity transport and no edge localized modes (ELMs). The regime has been demonstrated on the Alcator C-Mod, ASDEX Upgrade and DIII-D tokamaks, over a wide range of device parameters and pedestal conditions. Dimensionless parameters at the pedestal show overlap across devices and extend to low collisionality. When they are matched, pedestal temperature profiles are also similar. Pedestals are stable to peeling–ballooning modes, consistent with lack of ELMs. Access to I-mode is independent of heating method (neutral beam injection, ion cyclotron and/or electron cyclotron resonance heating). Normalized energy confinement H
98,y2  ⩾  1 has been achieved for a range of 3  ⩽  q
95  ⩽  4.9 and scales favourably with power. Changes in turbulence in the pedestal region accompany the transition from L-mode to I-mode. The L–I threshold increases with plasma density and current, and with device size, but has a weak dependence on toroidal magnetic field B
T. The upper limit of power for I-modes, which is set by I–H transitions, increases with B
T and the power range is largest on Alcator C-Mod at B  >  5 T. Issues for extrapolation to ITER and other future fusion devices are discussed.
SwiSpot: modeling riboswitches by spotting out switching sequences
Authors: Barsacchi Marco , Novoa Eva Maria , Kellis Manolis , Bechini Alessio 
Published: July 2016

Abstract
Motivation: Riboswitches are cis-regulatory elements in mRNA, mostly found in Bacteria, which exhibit two main secondary structure conformations. Although one of them prevents the gene from being expressed, the other conformation allows its expression, and this switching process is typically driven by the presence of a specific ligand. Although there are a handful of known riboswitches, our knowledge in this field has been greatly limited due to our inability to identify their alternate structures from their sequences. Indeed, current methods are not able to predict the presence of the two functionally distinct conformations just from the knowledge of the plain RNA nucleotide sequence. Whether this would be possible, for which cases, and what prediction accuracy can be achieved, are currently open questions.
Results: Here we show that the two alternate secondary structures of riboswitches can be accurately predicted once the ‘switching sequence’ of the riboswitch has been properly identified. The proposed SwiSpot approach is capable of identifying the switching sequence inside a putative, complete riboswitch sequence, on the basis of pairing behaviors, which are evaluated on proper sets of configurations. Moreover, it is able to model the switching behavior of riboswitches whose generated ensemble covers both alternate configurations. Beyond structural predictions, the approach can also be paired to homology-based riboswitch searches.
Availability and Implementation: SwiSpot software, along with the reference dataset files, is available at: http://www.iet.unipi.it/a.bechini/swispot/
Supplementary information: Supplementary data are available at Bioinformatics online.
Contact: a.bechini@ing.unipi.it
P2X receptors
Authors: North R. Alan 
Published: July 2016

Extracellular adenosine 5′-triphosphate (ATP) activates cell surface P2X and P2Y receptors. P2X receptors are membrane ion channels preferably permeable to sodium, potassium and calcium that open within milliseconds of the binding of ATP. In molecular architecture, they form a unique structural family. The receptor is a trimer, the binding of ATP between subunits causes them to flex together within the ectodomain and separate in the membrane-spanning region so as to open a central channel. P2X receptors have a widespread tissue distribution. On some smooth muscle cells, P2X receptors mediate the fast excitatory junction potential that leads to depolarization and contraction. In the central nervous system, activation of P2X receptors allows calcium to enter neurons and this can evoke slower neuromodulatory responses such as the trafficking of receptors for the neurotransmitter glutamate. In primary afferent nerves, P2X receptors are critical for the initiation of action potentials when they respond to ATP released from sensory cells such as taste buds, chemoreceptors or urothelium. In immune cells, activation of P2X receptors triggers the release of pro-inflammatory cytokines such as interleukin 1β. The development of selective blockers of different P2X receptors has led to clinical trials of their effectiveness in the management of cough, pain, inflammation and certain neurodegenerative diseases.This article is part of the themed issue ‘Evolution brings Ca2+and ATP together to control life and death’.
The homeostatic astroglia emerges from evolutionary specialization of neural cells
Authors: Verkhratsky Alexei , Nedergaard Maiken 
Published: July 2016

Evolution of the nervous system progressed through cellular diversification and specialization of functions. Conceptually, the nervous system is composed from electrically excitable neuronal networks connected with chemical synapses and non-excitable glial cells that provide for homeostasis and defence. Astrocytes are integrated into neural networks through multipartite synapses; astroglial perisynaptic processes closely enwrap synaptic contacts and control homeostasis of the synaptic cleft, supply neurons with glutamate and GABA obligatory precursor glutamine and contribute to synaptic plasticity, learning and memory. In neuropathology, astrocytes may undergo reactive remodelling or degeneration; to a large extent, astroglial reactions define progression of the pathology and neurological outcome.This article is part of the themed issue ‘Evolution brings Ca2+and ATP together to control life and death’.
Loss of flight in the Galapagos cormorant mirrors human skeletal ciliopathies
Authors: Burga Alejandro , Wang Weiguang , Wolf Paul C. , Ramey Andrew M. , Verdugo Claudio , Lyons Karen , Parker Patricia G. , Kruglyak Leonid 
Published: July 2016

AbstractChanges in the size and proportion of limbs and other structures have played a key role in the adaptive evolution of species. However, despite the ubiquity of these modifications, we have a very limited idea of how these changes occur on the genetic and molecular levels. To fill this gap, we studied a recent and extreme case of wing and pectoral skeleton size reduction leading to flightlessness in the Galapagos cormorant (Phalacrocorax harrisi). We sequenced and de novo assembled the genomes of four closely related cormorant species and applied a joint predictive and comparative genomics approach to find candidate variants. Here we report that function-altering variants in genes necessary for both the correct transcriptional regulation and function of the primary cilium contributed to the evolution of loss of flight inP. harrisi. Cilia are essential for Hedgehog signaling, and humans affected by skeletal ciliopathies suffer from premature arrest of bone growth, mirroring the skeletal features associated with loss of flight.
Anisotropic Correction of Beam-induced Motion for Improved Single-particle Electron Cryo-microscopy
Authors: Zheng Shawn Q. , Palovcak Eugene , Armache Jean-Paul , Cheng Yifan , Agard David A. 
Published: July 2016

AbstractCorrection of electron beam-induced sample motion is one of the major factors contributing to the recent resolution breakthroughs in cryo-electron microscopy. Improving the accuracy and efficiency of motion correction can lead to further resolution improvement. Based on observations that the electron beam induces doming of the thin vitreous ice layer, we developed an algorithm to correct anisotropic image motion at the single pixel level across the whole frame, suitable for both single particle and tomographic images. Iterative, patch-based motion detection is combined with spatial and temporal constraints and dose weighting. The multi-GPU accelerated program, MotionCor2, is sufficiently fast to keep up with automated data collection. The result is an exceptionally robust strategy that can work on a wide range of data sets, including those very close to focus or with very short integration times, obviating the need for particle polishing. Application significantly improves Thon ring quality and 3D reconstruction resolution.
HRM practices and post-promotion managerial performance
Authors: Wickramasinghe Vathsala , Samaratunga Melanie 
Published: July 2016

Purpose– The purpose of this paper is to investigate the relationship between human resource management (HRM) practices and post-promotion performance of managers from subordinates’ perspective.Design/methodology/approach– For the study, survey methodology was used and 391 respondents who fulfilled selection criteria set for the study responded. The hypothesised relationships were examined by regression analysis.Findings– It was found that the job description and promotion practices have significant relationship with post-promotion performance.Practical implications– The findings imply the importance of promotion practices and the need of maintaining and using job descriptions in facilitating post-promotion performance.Originality/value– Several previous studies investigated the post-promotion managerial performance based on mathematical modelling and single firm case studies. However, it is very rare to find academic research that investigated the relationship between HRM practices and post-promotion performance of managers.