bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of ACL Laxity Tests with Arthroscopic Findings in Chronic ACL and PCL Deficient Knees
Authors: Sazali S. , Rusdi A. , Siti H.
Published: March 2018

An anterior cruciate ligament (ACL) injury may be diagnosed by clinical examination and radiological investigation using magnetic resonance imaging or by arthroscopy.1,2 Based on our experience, the ACL tear in concomitant chronic ACL and posterior cruciate ligament (PCL) deficient knees may produce knee laxity, which is more difficult to assess on clinical examination, which in turn may affect the management algorithm of the patient. Our hypothesis is that, in a concomitant chronic ACL and PCL injury, posterior capsular contracture and abnormal reattachment of torn ACL will result in less clinical and subjective laxity, preoperatively. The aim of this study is to review a cohort of patients who had undergone PCL reconstructive surgery and compare the preoperative clinical assessments with and without anesthesia with arthroscopic finding of ACL. This is to assess the accuracy and reliability of clinical ACL laxity tests in detecting ACL tear in chronic ACL and PCL injury.
Glucose Gel in Infants at Risk for Transitional Neonatal Hypoglycemia
Authors: Alissa Rana , Dudek Christopher , Travers Laura , Smotherman Carmen , Hudak Mark , Makker Kartikeya
Published: March 2018

Objective To evaluate whether glucose gel as a supplement to feedings in infants admitted to the newborn nursery at risk for neonatal hypoglycemia (NH) reduces the frequency of transfer to a higher level of care for intravenous dextrose treatment.

Study Design We revised our newborn nursery protocol for management of infants at risk for NH to include use of 40% glucose gel (200 mg/kg). Study population included late preterm, small and large for gestational age infants, and infants of diabetic mothers. We compared outcomes before (4/1/14–3/31/15: Year 1) and after (4/1/15–3/31/16: Year 2) initiation of the revised protocol. Our prospective primary outcome was transfer to the neonatal intensive care unit (NICU) for treatment with a continuous infusion of dextrose.

Results NICU transfer for management of NH fell from 8.1% in Year 1 (34 of 421 at-risk infants screened) to 3.7% in Year 2 (14 of 383 at-risk infants screened). Rate of exclusive breastfeeding increased from 6% in Year 1 to 19% in Year 2. Hospital charges for the study population decreased from 801,276 USD to 387,688 USD in Year 1 and Year 2, respectively.

Conclusion Our study supports the adjunctive use of glucose gel to reduce NICU admissions and total hospitalization expense.
Late Coil Migration after Embolization of Cerebral Aneurysms – Case Series
Authors: Antunes Maranha Gatto Luana , Bandeira Rocha Luana , Koppe Gelson , Demartini Jr Zeferino
Published: March 2018

Background Coil migration after cerebral aneurysm embolization is a very rare complication. It can take place early or late in the postoperative period, evolving asymptomatic and causing severe neurological deficits. Ruptured aneurysms of anterior communicant artery were the most frequent reported examples in the literature.

Case Report We report three cases of patients with unruptured aneurysms treated with coils and remodeling balloon technique. The first case was that of a left posterior communicating artery aneurysm with coil migration to a distal cortical branch of ipsilateral middle cerebral artery (MCA). The patient had mild paresthesia in the arm for a few days. The second one was a fenestrated basilar artery aneurysm with coil migration to the P2 segment of the left posterior cerebral artery. The patient was fully asymptomatic. The third case was a MCA aneurysm with coil migration to the M3 segment. There were no ischemic complications, and all patients underwent a new endovascular procedure.

Conclusions Coil migration is a rare but not always severe complication. Antiplatelet agents are recommended even if the coil migration is asymptomatic.
Padé approximant for normal stress differences in large-amplitude oscillatory shear flow
Authors: Poungthong P. , Saengow C. , Giacomin A. J. , Kolitawong C. , Merger D. , Wilhelm M.
Published: March 2018

Analytical solutions for the normal stress differences in large-amplitude oscillatory shear flow (LAOS), for continuum or molecular models, normally take the inexact form of the first few terms of a series expansion in the shear rate amplitude. Here, we improve the accuracy of these truncated expansions by replacing them with rational functions called Padé approximants. The recent advent of exact solutions in LAOS presents an opportunity to identify accurate and useful Padé approximants. For this identification, we replace the truncated expansion for the corotational Jeffreys fluid with its Padé approximants for the normal stress differences. We uncover the most accurate and useful approximant, the [3,4] approximant, and then test its accuracy against the exact solution [C. Saengow and A. J. Giacomin, “Normal stress differences from Oldroyd 8-constant framework: Exact analytical solution for large-amplitude oscillatory shear flow,” Phys. Fluids 29, 121601 (2017)]. We use Ewoldt grids to show the stunning accuracy of our [3,4] approximant in LAOS. We quantify this accuracy with an objective function and then map it onto the Pipkin space. Our two applications illustrate how to use our new approximant reliably. For this, we use the Spriggs relations to generalize our best approximant to multimode, and then, we compare with measurements on molten high-density polyethylene and on dissolved polyisobutylene in isobutylene oligomer.
The barrier to ice nucleation in monatomic water
Authors: Prestipino Santi
Published: March 2018

Crystallization from a supercooled liquid initially proceeds via the formation of a small solid embryo (nucleus), which requires surmounting an activation barrier. This phenomenon is most easily studied by numerical simulation, using specialized biased-sampling techniques to overcome the limitations imposed by the rarity of nucleation events. Here, I focus on the barrier to homogeneous ice nucleation in supercooled water, as represented by the monatomic-water model, which in the bulk exhibits a complex interplay between different ice structures. I consider various protocols to identify solidlike particles on a computer, which perform well enough for the Lennard-Jones model, and compare their respective impact on the shape and height of the nucleation barrier. It turns out that the effect is stronger on the nucleus size than on the barrier height. As a by-product of the analysis, I determine the structure of the nucleation cluster, finding that the relative amount of ice phases in the cluster heavily depends on the method used for classifying solidlike particles. Moreover, the phase which is most favored during the earlier stages of crystallization may happen, depending on the nucleation coordinate adopted, to be different from the stable polymorph. Therefore, the quality of a reaction coordinate cannot be assessed simply on the basis of the barrier height obtained. I explain how this outcome is possible and why it just points out the shortcoming of collective variables appropriate to simple fluids in providing a robust method of particle classification for monatomic water.
Evolution of sausage and helical modes in magnetized thin-foil cylindrical liners driven by a Z-pinch
Authors: Yager-Elorriaga D. A. , Lau Y. Y. , Zhang P. , Campbell P. C. , Steiner A. M. , Jordan N. M. , McBride R. D. , Gilgenbach R. M.
Published: March 2018

In this paper, we present experimental results on axially magnetized (Bz = 0.5 – 2.0 T), thin-foil (400 nm-thick) cylindrical liner-plasmas driven with ∼600 kA by the Michigan Accelerator for Inductive Z-Pinch Experiments, which is a linear transformer driver at the University of Michigan. We show that: (1) the applied axial magnetic field, irrespective of its direction (e.g., parallel or anti-parallel to the flow of current), reduces the instability amplitude for pure magnetohydrodynamic (MHD) modes [defined as modes devoid of the acceleration-driven magneto-Rayleigh-Taylor (MRT) instability]; (2) axially magnetized, imploding liners (where MHD modes couple to MRT) generate m = 1 or m = 2 helical modes that persist from the implosion to the subsequent explosion stage; (3) the merging of instability structures is a mechanism that enables the appearance of an exponential instability growth rate for a longer than expected time-period; and (4) an inverse cascade in both the axial and azimuthal wavenumbers, k and m, may be responsible for the final m = 2 helical structure observed in our experiments. These experiments are particularly relevant to the magnetized liner inertial fusion program pursued at Sandia National Laboratories, where helical instabilities have been observed.
Understanding luminescence properties of grain boundaries in GaN thin films and their atomistic origin
Authors: Yoo Hyobin , Yoon Sangmoon , Chung Kunook , Kang Seoung-Hun , Kwon Young-Kyun , Yi Gyu-Chul , Kim Miyoung
Published: March 2018

We report our findings on the optical properties of grain boundaries in GaN films grown on graphene layers and discuss their atomistic origin. We combine electron backscatter diffraction with cathodoluminescence to directly correlate the structural defects with their optical properties, enabling the high-precision local luminescence measurement of the grain boundaries in GaN films. To further understand the atomistic origin of the luminescence properties, we carefully probed atomic core structures of the grain boundaries by exploiting aberration-corrected scanning transmission electron microscopy. The atomic core structures of grain boundaries show different ordering behaviors compared with those observed previously in threading dislocations. Energetics of the grain boundary core structures and their correlation with electronic structures were studied by first principles calculation.
Effects of a reentry plasma sheath on the beam pointing properties of an array antenna
Authors: Bai Bowen , Liu Yanming , Lin Xiaofang , Li Xiaoping
Published: March 2018

The reduction in the gain of an on-board antenna caused by a reentry plasma sheath is an important effect that contributes to the reentry “blackout” problem. Using phased array antenna and beamforming technology could provide higher gain and an increase in the communication signal intensity. The attenuation and phase delay of the electromagnetic (EM) waves transmitting through the plasma sheath are direction-dependent, and the radiation pattern of the phased array antenna is affected, leading to a deviation in the beam pointing. In this paper, the far-field pattern of a planar array antenna covered by a plasma sheath is deduced analytically by considering both refraction and mutual coupling effects. A comparison between the analytic results and the results from an electromagnetic simulation is carried out. The effect of the plasma sheath on the radiation pattern and the beam pointing errors of the phased array antenna is studied systematically, and the derived results could provide useful information for the correction of pointing errors.
Numerical simulation of dark envelope soliton in plasma
Authors: Wang Fang-Ping , Han Juan-fang , Zhang Jie , Gao Dong-Ning , Li Zhong-Zheng , Duan Wen-Shan , Zhang Heng
Published: March 2018

One-dimensional (1-D) particle-in-cell simulation is used to study the propagation of dark envelop solitons described by the nonlinear Schrödinger equation (NLSE) in electron-ion plasmas. The rational solution of the NLSE is presented, which is proposed as an effective tool for studying the dark envelope soliton in plasma. It is demonstrated by our numerical simulation that there is dark envelope soliton in electron-ion plasmas. The numerical results are in good agreements with the analytical ones from the NLSE which is obtained from the reductive perturbation method. The limitation of the amplitude of dark envelop solitons in plasma is noticed.
Investigation of ionic conduction in PEO–PVDF based blend polymer electrolytes
Authors: Patla Subir Kumar , Ray Ruma , Asokan K. , Karmakar Sanat
Published: March 2018

We investigate the effect of blend host polymer on solid polymer electrolyte (SPE) films doped with ammonium iodide (NH4I) salt using a variety of experimental techniques. Structural studies on the composite SPEs show that the blending of Poly(ethylene oxide) (PEO)–Poly(vinylidene fluoride) (PVDF) polymers in a suitable ratio enhances the amorphous fraction of the polymer matrix and facilitates fast ion conduction through it. We observe that the addition of a small amount of PVDF in the PEO host polymer enhances the ion – polymer interaction leading to more ion dissociation. As a result, the effective number of mobile charge carriers within the polymer matrix increases. Systematic investigation in these blend SPEs shows that the maximum conductivity (1.01 × 10–3 S/cm) is obtained for PEO – rich (80 wt. % PEO, 20 wt. % PVDF) composites at 35 wt. % NH4I concentration at room temperature. Interestingly, at higher salt concentrations (above 35 wt. %), the conductivity is found to decrease in this system. The reduction of conductivity at higher salt concentrations is the consequence of decrease in the carrier concentration due to the formation of an ion pair and ion aggregates. PVDF–rich compositions (20 wt. % PEO and 80 wt. % PVDF), on the other hand, show a very complex porous microstructure. We also observe a much lower ionic conductivity (maximum ∼ 10–6 S/cm at 15 wt. % salt) in these composite systems relative to PEO-rich composites.
Photoacoustic signal attenuation analysis for the assessment of thin layers thickness in paintings
Authors: Tserevelakis George J. , Dal Fovo Alice , Melessanaki Krystalia , Fontana Raffaella , Zacharakis Giannis
Published: March 2018

This study introduces a novel method for the thickness estimation of thin paint layers in works of art, based on photoacoustic signal attenuation analysis (PAcSAA). Ad hoc designed samples with acrylic paint layers (Primary Red Magenta, Cadmium Yellow, Ultramarine Blue) of various thicknesses on glass substrates were realized for the specific application. After characterization by Optical Coherence Tomography imaging, samples were irradiated at the back side using low energy nanosecond laser pulses of 532 nm wavelength. Photoacoustic waves undergo a frequency-dependent exponential attenuation through the paint layer, before being detected by a broadband ultrasonic transducer. Frequency analysis of the recorded time-domain signals allows for the estimation of the average transmitted frequency function, which shows an exponential decay with the layer thickness. Ultrasonic attenuation models were obtained for each pigment and used to fit the data acquired on an inhomogeneous painted mock-up simulating a real canvas painting. Thickness evaluation through PAcSAA resulted in excellent agreement with cross-section analysis with a conventional brightfield microscope. The results of the current study demonstrate the potential of the proposed PAcSAA method for the non-destructive stratigraphic analysis of painted artworks.
Graphene-induced modulation effects on magnetic plasmon in multilayer metal-dielectric-metal metamaterial
Authors: Li Daimin , Wang Wei , Zhang Hong , Zhu Yuhang , Zhang Song , Zhang Zhiyi , Zhang Xinpeng , Yi Juemin , Wei Wei
Published: March 2018

Motivated by the increasing interest in active control of the optical response in magnetic metamaterials, we theoretically demonstrate that monolayer graphene, even only a single atom thick, can provide an efficient modulation on the magnetic plasmon (MP) resonance, including over 10 meV resonance shift and over 25% modulation of resonance absorption intensity. We show that the resonance shift is distinctly different from the graphene-induced change in electrically excited surface plasmon resonances in plasmonic systems. Our analysis based on the equivalent nanocircuit method reveals that the MP resonance shift is governed by both the real and imaginary parts of graphene permittivity. Importantly, we find that an additional dissipation channel relevant to the graphene-induced resistance governs the MP absorption and that even the dissipation channel of interband transition is blocked. The interplay between both channels results in a pronounced modification of MP absorption intensities. The findings will offer a promising way to realize the dynamic control of the magnetic response, which holds great potential applications in graphene-based active metamaterials.
A binary collision Monte Carlo model for electron-ion temperature relaxation
Authors: Zhao Yinjian
Published: March 2018

Monte Carlo models have been widely used in particle simulations to efficiently solve Coulomb collisions in plasma systems. A binary collision Monte Carlo model is proposed for electron-ion temperature relaxation, which involves all types of collisions and uses the effective maximum and minimum impact parameters that are found previously from Particle-Particle simulations. This binary model and a commonly used model, Nanbu's model, are compared with a Particle-Particle model which serves as a baseline. The results of the binary model match very well with those of the Particle-Particle, but not with those of Nanbu's, meaning that the binary model is more accurate than Nanbu's model for the plasma condition considered. An additional finding is that the effective maximum and minimum impact parameters can be used to calculate the Coulomb logarithm to improve the accuracy of Nanbu's model.
Numerical model simulates dynamics of levitating droplet evaporation
Authors: Liebendorfer Adam
Published: March 2018

With an eye on applications in pharmaceuticals, new simulations can characterize several features of evaporating droplets as they are suspended in an ultrasonic field.
HealthNavigator: a mobile application for chronic disease screening and linkage to services at an urban Primary Health Network
Authors: Seneviratne Martin G. , Hersch Fred , Peiris David P.
Published: March 2018

Mobile applications (apps) are promising tools to support chronic disease screening and linkage to health services. They have the potential to increase healthcare access for vulnerable populations. The HealthNavigator app was developed to provide chronic disease risk assessments, linkage to local general practitioners (GPs) and lifestyle programs, and a personalised health report for discussion with a GP. Assessments were either self-administered or facilitated by community health workers through a Primary Health Network (PHN) initiative targeting ethnically diverse communities. In total, 1492 assessments (80.4% self-administered, 19.6% facilitated) were conducted over a 12-month period in Queensland, Australia. Of these, 26% of people screened came from postcodes representing the lowest quartile of socioeconomic disadvantage. When compared against self-administered assessments, subjects screened by the facilitated program were more likely to be born outside Australia (80.5 v. 33.2%, P<0.001), and to fall within a high risk category based on cardiovascular risk scores (19.8 v. 13.7%, P<0.01) and type 2 diabetes mellitus risk scores (58.0 v. 40.1%, P<0.001). Mobile apps embedded into PHN programs may be a useful adjunct for the implementation of community screening programs. Further research is needed to determine their effect on health service access and health outcomes.
IRF9 and unphosphorylated STAT2 cooperate with NF-κB to drive IL6 expression
Authors: Nan Jing , Wang Yuxin , Yang Jinbo , Stark George R.
Published: March 2018

Significance

We describe unexpected cooperation between two cytokines that are important in regulating the growth of cancers, namely, type I interferons (IFNs) and interleukin 6 (IL6). It is well established that IL6 is vital for the ability of many tumor types to prosper, and the work in the current paper reveals that the signaling pathway driven by IFN, which is also evident in many cancers, increases the expression of IL6 through a direct effect on theIL6gene. The findings may help to identify new antitumor targets for therapy.
Reduction of lipid accumulation rescues Bietti’s crystalline dystrophy phenotypes
Authors: Hata Masayuki , Ikeda Hanako O. , Iwai Sachiko , Iida Yuto , Gotoh Norimoto , Asaka Isao , Ikeda Kazutaka , Isobe Yosuke , Hori Aya , Nakagawa Saori , Yamato Susumu , Arita Makoto , Yoshimura Nagahisa , Tsujikawa Akitaka
Published: March 2018

Significance

Bietti’s crystalline dystrophy (BCD) is an autosomal recessive, progressive chorioretinal degenerative disease. Retinal pigment epithelium (RPE) cells are impaired in patients with BCD, but the underlying mechanisms of RPE cell damage have not yet been determined because cells from lesions cannot be readily acquired from patients with BCD. In the present study, we successfully generated a human in vitro model of BCD, BCD patient-specific iPSC-RPE cells, and demonstrated that the accumulation of free cholesterol caused RPE cell damage and subsequent cell death via the induction of lysosomal dysfunction and impairment of autophagy flux in BCD-affected cells. We believe these findings provide evidence of the possible therapeutic efficacy of reducing intracellular free cholesterol in BCD.
Embryophyte stress signaling evolved in the algal progenitors of land plants
Authors: de Vries Jan , Curtis Bruce A. , Gould Sven B. , Archibald John M.
Published: March 2018

Significance

The evolution of land plants from algae is an age-old question in biology. The entire terrestrial flora stems from a grade of algae, the streptophyte algae. Recent phylogenomic studies have pinpointed the Zygnematophyceae as the modern-day streptophyte algal lineage that is most closely related to the algal land plant ancestor. Here, we provide insight into the biology of this ancestor that might have aided in its conquest of land. Specifically, we uncover the existence of stress-signaling pathways and the potential for intimate plastid-nucleus communication. Plastids act as environmental sensors in land plants; our data suggest that this feature was present in a common ancestor they shared with streptophyte algae.
Structural determinants and cellular environment define processed actin as the sole substrate of the N-terminal acetyltransferase NAA80
Authors: Goris Marianne , Magin Robert S. , Foyn Håvard , Myklebust Line M. , Varland Sylvia , Ree Rasmus , Drazic Adrian , Bhambra Parminder , Støve Svein I. , Baumann Markus , Haug Bengt Erik , Marmorstein Ronen , Arnesen Thomas
Published: March 2018

Significance

N-terminal acetylation performed by N-terminal acetyltransferases (NATs) is a common protein modification in human cells. A unique NAT, NAA80, was recently found to control actin N-terminal acetylation and cytoskeletal dynamics. In this study, we developed potent and specific bisubstrate inhibitors against NAA80 and determined the crystal structure of NAA80 in complex with an inhibitor mimicking the β-actin N terminus, thus revealing molecular determinants for the substrate specificity and selective inhibition of NAA80. A yeast model uncovered how a cellular determinant, the NatB enzyme, acts to restrict the number of in vivo NAA80 substrates relative to the broader intrinsic capacity of NAA80. Our data provide a starting point for further development of inhibitors for the regulation of actin and cytoskeletal functions.
Divergent trends of open-surface water body area in the contiguous United States from 1984 to 2016
Authors: Zou Zhenhua , Xiao Xiangming , Dong Jinwei , Qin Yuanwei , Doughty Russell B. , Menarguez Michael A. , Zhang Geli , Wang Jie
Published: March 2018

Significance

Strong variations in open-surface water body areas have impacted United States agriculture, economy, society, and ecosystems. This study presents the uneven water-resource distribution across the contiguous United States with the western half of the United States having less water body area but stronger interannual variability compared with the eastern half. Divergent trends of open-surface water body area in the last three decades, mainly driven by climate, indicated that the water-poor regions of the Southwest and Northwest United States were getting poorer, while the water-rich regions of Southeast and far north Great Plains were getting richer. Surface water body shrinkage in drought years led to massive groundwater mining and the rapid decrease of land water storage in California and the southern Great Plains.
Circadian clock activity of cryptochrome relies on tryptophan-mediated photoreduction
Authors: Lin Changfan , Top Deniz , Manahan Craig C. , Young Michael W. , Crane Brian R.
Published: March 2018

Significance

This work resolves a long-standing controversy regarding the activation mechanism and photocycle of cryptochromes (CRYs), a broadly represented group of photosensors. We demonstrate a high degree of correspondence between the capability of the tryptophan (Trp) chain to photoreduce the flavin cofactor and biological activity. These results establish that the evolutionary pressure to conserve the Trp chain derives from maintaining a flavin photocycle that, in this case, entrains the fly circadian clock. Furthermore, we reengineer CRY to be more biologically photoresponsive by manipulating photoreduction by the Trp chain. As CRYs are important signaling molecules in animals, plants, and bacteria, and are increasingly used as optogenetic tools, the defined mechanism is relevant to many signaling processes and will enable novel applications.
Chloroplast SRP43 acts as a chaperone for glutamyl-tRNA reductase, the rate-limiting enzyme in tetrapyrrole biosynthesis
Authors: Wang Peng , Liang Fu-Cheng , Wittmann Daniel , Siegel Alex , Shan Shu-ou , Grimm Bernhard
Published: March 2018

Significance

During the biogenesis of light-harvesting complexes, the posttranslational chloroplast signal recognition particle (cpSRP) pathway is highly coordinated with chlorophyll (Chl) biosynthesis. To ensure the required supply of newly synthesized Chl for the assembly of light-harvesting Chl a/b-binding proteins (LHCPs) while avoiding the accumulation of photoreactive tetrapyrrole intermediates, Chl synthesis is tightly regulated at the level of glutamyl-tRNA reductase (GluTR), the initial enzyme of rate-limiting 5-aminolevolinic acid (ALA) synthesis. Here, we found that the chaperone for LHCPs, the chloroplast SRP43, directly binds to and prevents aggregation of GluTR, thereby enhancing the stability of active GluTR. This finding reveals a posttranslational control of ALA synthesis, which helps plants to adjust their Chl synthesis rate in response to fluctuating environmental conditions.
Continuous plating/stripping behavior of solid-state lithium metal anode in a 3D ion-conductive framework
Authors: Yang Chunpeng , Zhang Lei , Liu Boyang , Xu Shaomao , Hamann Tanner , McOwen Dennis , Dai Jiaqi , Luo Wei , Gong Yunhui , Wachsman Eric D. , Hu Liangbing
Published: March 2018

Significance

Solid-state lithium metal anode possesses great promise owing to its high energy density and improved safety. This work introduces a strategy for constructing a 3D Li metal anode, which is hosted in a solid-state ion-conducting host and shows a safe and dendrite-free plating/stripping behavior. The host is based on a garnet-type ion-conductive framework and a bottom-deposited Cu current collector. The Li anode is plated within the solid garnet framework from the bottom Cu layer and shows a dendrite-free deposition behavior, effectively averting the dendrite penetration issue. Owing to the 3D ion-conductive host, the volume change and interface contact problem of the Li anode have been significantly mitigated, realizing a high-capacity and safe Li metal anode for solid-state high-energy-density batteries.
Water-mediated conformational preselection mechanism in substrate binding cooperativity to protein kinase A
Authors: Setny Piotr , Wiśniewska Marta D.
Published: March 2018

Significance

Cooperativity in substrate binding to a protein often involves some kind of interaction between distant binding sites mediated by the protein structure. Experimental studies indicate that the cooperative effect in protein kinase A relies on a shift in conformational equilibrium of the catalytic subunit, but its exact molecular basis remains unclear. Our molecular dynamics simulations provide atomistic insight into conformational states visited by the enzyme and its complexes and suggest a plausible mechanistic model contributing to cooperative substrate binding. Intriguingly, an important role seems to be played by water molecules that occupy two conserved hydration sites within the catalytic subunit.
Cooption of an appendage-patterning gene cassette in the head segmentation of arachnids
Authors: Setton Emily V. W. , Sharma Prashant P.
Published: March 2018

Significance

In the fruit fly, ventral appendage (leg) identity is specified by a gene network includingWnt-1/wg,Sp6-9, andDll, but little is known about the conservation of this network beyond insects. We disrupted Wnt signaling andSp6-9in a spider, a member of Chelicerata, the sister group to all remaining arthropods. Our results provide support for the conservation of a leg development gene regulatory network across Arthropoda.Dllhas previously been reported to have a role in head segmentation that is restricted to spiders, and we show here that theSp6-9/Dllcassette has been independently coopted for arachnid head segmentation.
Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca
2+
dynamics in
Arabidopsis
Authors: Corso Massimiliano , Doccula Fabrizio G. , de Melo J. Romário F. , Costa Alex , Verbruggen Nathalie
Published: March 2018

Significance

Given the lack of a nervous system in plants, signaling molecules, such as Ca
2+
, are of vital importance for perceiving environmental stimuli. However, little information on the genes that control this network is available. Our demonstration that
Arabidopsis
CCX2, localized to the endoplasmic reticulum, modulates osmotic stress responses through the regulation of cytosolic and endoplasmic reticulum Ca
2+
concentrations is one more step toward identifying all the players involved in plant stress responses. The elucidation of these pathways will help to meet the necessary requirements to face global challenges, such as high salinity on the world’s surface, including arable land. This work sheds light on an as yet uncharacterized and key player that tunes intracellular Ca
2+
homeostasis, with particular significance for plants under salt stress.
Reversal of orbital angular momentum arising from an extreme Doppler shift
Authors: Gibson Graham M. , Toninelli Ermes , Horsley Simon A. R. , Spalding Gabriel C. , Hendry Euan , Phillips David B. , Padgett Miles J.
Published: March 2018

Significance

The emergence of “negative” frequencies in physical systems is often accompanied by intriguing consequences. For example, supersonic motion between a source and an observer leads to a negative Doppler-shifted frequency, the physical meaning of which is time reversal of the received signal. To our knowledge, the rotational analogue of this situation—the consequences of generating negative rotationally Doppler-shifted waves—has not been studied. Here we show, using an acoustic source, that a negative rotational Doppler shift is associated with a handedness reversal of the orbital angular momentum carried by the wave. We demonstrate that this handedness reversal can occur even at significantly subsonic velocities, making our findings relevant to interactions of ultrafast rotating systems with optical frequency radiation.
Cross-linking of Orai1 channels by STIM proteins
Authors: Zhou Yandong , Nwokonko Robert M. , Cai Xiangyu , Loktionova Natalia A. , Abdulqadir Raz , Xin Ping , Niemeyer Barbara A. , Wang Youjun , Trebak Mohamed , Gill Donald L.
Published: March 2018

Significance

The work presents a unique understanding of the organization and function of two ubiquitously expressed proteins, central in generating calcium signals in all cell types. These are the intracellular calcium sensing “STIM” proteins, and the highly selective cell surface “Orai” calcium channels. We reveal that STIM proteins can cross-link Orai channels, resulting in a reorganized microenvironment within the membrane junctions in which they function, with important consequences in the generation of oscillatory calcium signals. Interestingly, we show a variant STIM protein widely expressed in cells functions to prevent the STIM–Orai cross-linking and clustering of channels. This provides important modulation of calcium signal generation and can serve to protect cells from overstimulation of the calcium signaling machinery.
Recombinant immunotoxins with albumin-binding domains have long half-lives and high antitumor activity
Authors: Wei Junxia , Bera Tapan K. , Liu Xiu Fen , Zhou Qi , Onda Masanori , Ho Mitchell , Tai Chin-Hsien , Pastan Ira
Published: March 2018

Significance

Recombinant immunotoxins are anticancer agents consisting of Fv of an antibody that targets a cancer cell and a protein toxin that kills the cell. Despite its short half-life in the circulation, Moxetumomab pasudotox is a recombinant immunotoxin that has produced many complete regressions in patients with leukemia, because the leukemia cells are readily accessible to the agent. Immunotoxins targeting solid tumors are less active, because it takes many hours to enter bulky tumors and by then the blood levels have fallen to ineffective levels. To overcome this deficiency, we have designed and produced a generation of immunotoxins containing albumin-binding domains that dramatically increase their half-life in the circulation and antitumor activity in mice.
Binding site for coenzyme A revealed in the structure of pyruvate:ferredoxin oxidoreductase from
Moorella thermoacetica
Authors: Chen Percival Yang-Ting , Aman Heather , Can Mehmet , Ragsdale Stephen W. , Drennan Catherine L.
Published: March 2018

Significance

In part due to concerns over greenhouse gas levels, interest in enzymes that fix carbon dioxide is considerable. The 2-oxoacid:ferredoxin oxidoreductases are essential enzymes in three of six of the known pathways of biological CO
2
fixation. Only one member of this enzyme superfamily has been extensively characterized by spectroscopy, kinetic analyses, and computation, and that is the pyruvate:ferredoxin oxidoreductase (PFOR) from the model acetogen
Moorella thermoactica
. Remarkably, electron transfer between cofactors in PFOR is gated by coenzyme A (CoA) such that CoA binding accelerates electron transfer from 4 min to 1 ms. Here we present the structure of this well-characterized PFOR and reveal the binding mode of CoA with the accompanying domain movements and conformational rearrangements.
Sortase ligation enables homogeneous GPCR phosphorylation to reveal diversity in β-arrestin coupling
Authors: Staus Dean P. , Wingler Laura M. , Choi Minjung , Pani Biswaranjan , Manglik Aashish , Kruse Andrew C. , Lefkowitz Robert J.
Published: March 2018

Significance

β-Arrestin regulates G protein-coupled receptor (GPCR) signaling by interacting with two regions of agonist-activated receptors—the phosphorylated C terminus and the seven transmembrane helix bundle. The phosphorylation pattern on GPCRs is thought to be the primary driver of β-arrestin binding affinity and functional consequences. To more effectively delineate the relative contributions of these two interactions, we present an innovative strategy to homogeneously phosphorylate purified GPCRs—enzymatic ligation of a synthetic phosphopeptide. This approach unexpectedly revealed that different receptors with identical phosphorylation patterns exhibit dramatic variability in their ability to couple to β-arrestin through the transmembrane core. These differences could play an important role in tuning the balance of G protein- and β-arrestin–mediated cellular signaling pathways stimulated by each GPCR.
Internal states and extrinsic factors both determine monkey vocal production
Authors: Liao Diana A. , Zhang Yisi S. , Cai Lili X. , Ghazanfar Asif A.
Published: March 2018

Significance

Understanding how human speech evolved requires investigating how our closest extant relatives—nonhuman primates—use and produce their vocalizations. However, some believe that primate vocalizations are driven purely by internal states such as arousal and thus have little or no relationship with human speech. We show that, in marmoset monkeys, vocal production varies systematically as a function of social distance and—via measures of heart rate—with arousal levels. However, arousal is not inextricably linked with primate vocal production. Rather, it interacts in complex ways with external cues, revealing the interplay between communication and energetic demands.
Endothelial GqPCR activity controls capillary electrical signaling and brain blood flow through PIP
2
depletion
Authors: Harraz Osama F. , Longden Thomas A. , Dabertrand Fabrice , Hill-Eubanks David , Nelson Mark T.
Published: March 2018

Significance

Capillaries, the smallest blood vessels, mediate the on-demand delivery of oxygen and nutrients required to support the function of active cells throughout the brain. But how blood flow is directed to cells in active brain regions to satisfy their energy needs is poorly understood. We demonstrate that the plasma membrane phospholipid, PIP
2
, is fundamental to sustaining the activity of inwardly rectifying potassium channels—the molecular feature that allows capillary endothelial cells to sense ongoing neuronal activity and trigger an increase in local blood flow. We further show that chemical factors released in the brain, including those associated with neuronal activity, cause changes in the levels of PIP
2
, thereby altering endothelial potassium channel signaling and controlling cerebral blood flow.
BACE1 SUMOylation increases its stability and escalates the protease activity in Alzheimer’s disease
Authors: Bao Jian , Qin Min , Mahaman Yacoubou Abdoul Razak , Zhang Bin , Huang Fang , Zeng Kuan , Xia Yiyuan , Ke Dan , Wang Qun , Liu Rong , Wang Jian-Zhi , Ye Keqiang , Wang Xiaochuan
Published: March 2018

Significance

BACE1 is a rate-limiting enzyme for amyloid beta polypeptide production, which plays a crucial role in Alzheimer’s disease (AD) pathogenesis. However, how this essential protease is posttranslationally regulated remains incompletely understood. In the current study, we show that K501 residue on BACE1, a ubiquitin modification site, is also competitively SUMOylated. We discovered that SUMOylation of BACE1 augments its stability and enzymatic activity, resulting in senile plaque formation and cognitive defect. Identification of the posttranslational modification on BACE1 provides insight into the molecular mechanism in AD.
LTP requires postsynaptic PDZ-domain interactions with glutamate receptor/auxiliary protein complexes
Authors: Sheng Nengyin , Bemben Michael A. , Díaz-Alonso Javier , Tao Wucheng , Shi Yun Stone , Nicoll Roger A.
Published: March 2018

Significance

Long-term potentiation (LTP) is the most compelling cellular and molecular model for learning and memory. Both AMPARs and KARs, two separate classes of glutamate receptor with very limited homology, express normal LTP in pyramidal neurons. However, the general underlying molecular mechanism remains a mystery. Here, with the strategy of single-cell molecular replacement we show that the PDZ-binding domains of AMPAR/TARP and KAR/Neto receptor complexes are essential for basal synaptic transmission and LTP. Our work suggests that the glutamate receptors share the same postsynaptic requirement for LTP.
Debussy's Speculative Idea: Orchestration and the Substance of Jeux
Authors: Clarke Simon
Published: March 2018

This article seeks to determine the extent to which timbral and textural concerns inform the musical substance of Debussy's Jeux. Of particular interest are passages in which foreground detail effaces itself in the interests of orchestral qualities, those where an overabundance of surface detail is preconfigured so as to maximize orchestral efficacy, and sections where a more traditional distinction between compositional content and orchestrational attributes seems to obtain. It is Hegelian substance ultimately that I have in mind, however, on which basis I seek to distinguish between unification and synthesis – I argue that Jeux's immediacy is overcome through negating (orchestrational) activity, arriving thus at the objectively real (realized and posited) product. On this basis, Jeux's substance, including its orchestral aspects, is best understood speculatively.
Constraining the mass of dark photons and axion-like particles through black-hole superradiance
Authors: Cardoso Vitor , Dias Óscar J.C. , Hartnett Gavin S. , Middleton Matthew , Pani Paolo , Santos Jorge E.
Published: March 2018

Ultralight bosons and axion-like particles appear naturally in different scenarios and could solve some long-standing puzzles. Their detection is challenging, and all direct methods hinge on unknown couplings to the Standard Model of particle physics. However, the universal coupling to gravity provides model-independent signatures for these fields. We explore here the superradiant instability of spinning black holes triggered in the presence of such fields. The instability taps angular momentum from and limits the maximum spin of astrophysical black holes. We compute, for the first time, the spectrum of the most unstable modes of a massive vector (Proca) field for generic black-hole spin and Proca mass. The observed stability of the inner disk of stellar-mass black holes can be used to derivedirectconstraints on the mass of dark photons in the mass range  10−13 eV≲ mV ≲ 3× 10−12 eV. By including also higher azimuthal modes, similar constraints apply to axion-like particles in the mass range 6×10−13 eV≲ mALP ≲ 10−11 eV. Likewise, mass and spin distributions of supermassive BHs—as measured through continuum fitting, Kα iron line, or with the future space-based gravitational-wave detector LISA – imply indirect bounds in the mass range approximately 10−19 eV≲ mV, mALP ≲ 10−13 eV, for both axion-like particles and dark photons. Overall, superradiance allows to explore a region of approximately 8 orders of magnitude in the mass of ultralight bosons.
Demonstration of multi-Watt all-fiber superfluorescent source operating near 980 nm*
Authors: Ren Yankun , Cao Jianqiu , Ying Hanyuan , Chen Heng , Pan Zhiyong , Du Shaojun , Chen Jinbao
Published: March 2018

The superfluorescent Yb-doped fiber source operating near 980 nm is studied. The design requirement is theoretically discussed aiming to suppress the amplified spontaneous emission around 1030 nm in the 980-nm superfluorescent fiber source. Based on the theoretical study, a multi-Watt, all-fiber, bi-directional, pumped, superfluorescent source operating near 980 nm is designed and experimentally demonstrated for the first time, to the best of our knowledge. The recorded 8.38-W combined output power is obtained with a 3-dB bandwidth about 3.5 nm. The power scaling of the 980-nm superfluorescent fiber source is limited by the parasitic laser oscillation.
Developer-led gentrification and legacies of urban policy failure in Post-Riot Tottenham
Authors: Dillon Denis , Fanning Bryan
Published: March 2018

This article is a sequel to an analysis of diagnoses of the causes of the 2011 Tottenham Riots published in this journal (2012) which charts the emergence of a predominant focus on developer-led gentrification in the area. We locate this focus on gentrification within United Kingdom urban policy and political debates and through a historical analysis of regeneration policy and community development as this played out in Northumberland Park, the most deprived area of Tottenham.
Demographic-Specific Rates for Life Events in the Cardiovascular Health Study and Comparisons With Other Studies
Authors: Vitaliano Peter P , Fitzpatrick Annette L , Williams Lee E , Montano Michalina A , Russo Joan E
Published: March 2018

Purpose of the Study

(1a) We use the Cardiovascular Health Study (CHS), a multi-site heterogeneous sample of Medicare enrollees (N = 5,849) to provide rates for specific life events experienced within 6 months; (1b) We present rates for 29 other studies of community-residing older adults (N = 41,308); (2) For the CHS, we provide demographic-specific rates and predicted probabilities for age [young-old (65–75) vs old-old (≥75)], gender, race, marital status, and education.

Design/Methods

The CHS sample is 57.6% women, 84.2% white (15.8% black), and 66.3% married. Mean age is 72.8 years (standard deviation [SD] = 5.6, range = 65–100) and education is 13.7 years (SD = 4.8). Life events were interviewer-assessed. Regressions estimated associations of life event rates with demographic groups (e.g., age), controlling for other demographic variables (e.g., gender, etc.).

Results

(1a) CHS rates ranged from 44.7% (death of someone close) to 1.1% (retirement/work changes). (1b) Most life event studies used total scores and only 5 that met our inclusion criteria used time intervals <1 year; longer intervals were associated with higher rates. (2) In the CHS, the life event for illnesses was related to 5 demographic variables (net the other 4 demographic variables), difficulties caregiving to 4, and worse relationships to 3 demographic variables. Race was related to 8 life events, marital status to 7, education to 6, and age to 4 events.

Implications

By identifying demographic groups at highest risk for life events, this research focuses on older adults at greatest risk for health problems. These data are necessary for translating research into interventions, practice, and policy.
Multinational Enterprises and Investment Treaties
Authors: Mark Feldman
Published: March 2018

Over the past few decades, a few thousand international investment agreements have been concluded. One cornerstone of those treaties has been a straightforward model of foreign investment: an investor based in a home state that has made an investment located in the territory of a host state. Under that model, treaty protections operate reciprocally, protecting the investments of each treaty party’s nationals made in the territory of another treaty party. That model, however, often does not capture current economic reality. Foreign investments by multinational enterprises routinely involve multiple jurisdictions in which inputs are traded and through which capital is channeled. The reliance by multinational enterprises on international production networks and transit investment has challenged the reciprocal foundation of investment treaties. This chapter responds to that risk by developing strategies for policymakers and decision makers to preserve the reciprocal foundation of investment treaties in a twenty-first-century global economy.
When Some are More Equal than Others
Authors: Eve Bain
Published: March 2018

The equality of parties is a fundamental procedural norm. Investor-state arbitration poses novel challenges to the proper application of this principle, particularly in regulating the presentation of evidence and the exercise of state sovereign authority. While investors and states are nominally equal, there can be a vast discrepancy between their respective coercive and economic power. In light of this, the principle of equality of the parties must be given more substantive content, reflecting true equality of treatment, rather than being limited to a strict notion of formal equality. This chapter argues that arbitral tribunals should have regard to wider considerations as part of the inherent power and duty to safeguard the integrity of their proceedings, and to ensure procedural equality.