bluuebunny/crossref_metadata_2025 huggingface dataset:
Cycloaddition versus Cleavage of the C=S Bond of Isothiocyanates Promoted by Digallane Compounds with Noninnocent α‐Diimine Ligands
Authors: Zhang Wei , Dodonov Vladimir A. , Chen Weixing , Zhao Yanxia , Skatova Alexandra A. , Fedushkin Igor L. , Roesky Peter W. , Wu Biao , Yang Xiao‐Juan
Published: July 2018

Whereas the chemistry of single‐bond activation by compounds of the main group elements has undergone some development in recent years, the cleavage of multiple bonds remains underexplored. Herein, the reactions of two digallanes bearing α‐diimine ligands, namely, [L1Ga−GaL1] (1, L1=dpp‐dad=[(2,6‐iPr2C6H3)NC(CH3)]2) and [L2Ga−GaL2] (2, L2=dpp‐bian=1,2‐[(2,6‐iPr2C6H3)NC]2C10H6), with isothiocyanates are reported. Reactions of 1 or 2 with isothiocyanates in 1:2 molar ratio proceeded with [2+4] cycloaddition of the C=S bond across the C2N2Ga metallacycle with formation of C−C and S−Ga single bonds to afford [L1(RN=C−S)Ga−Ga(S−C=NR)L1] (3, R=Me; 4, R=Ph) and [L2(RN=C−S)Ga−Ga(S−C=NR)L2] (8, R=allyl; 9, R=Ph). In the cases of 8 and 9, this cycloaddition is reversible. The digallanes reacted with 2 equiv of PhNCS in the presence of Na metal or at high temperatures through a unique reductive cleavage of the C=S bond to yield the disulfide‐bridged digallium species [Na(THF)3]2[L1Ga(μ‐S)2GaL1] (5), [L2Ga(μ‐S)2GaL2] (10), and [Na(DME)3][L2Ga(μ‐S)2GaL2] (11). Moreover, products 4 and 5 can further react with an excess of isothiocyanate, through cleavage of the C=S bond or cycloaddition, to give the bis‐ or mono‐S‐bridged complexes [Na(THF)2]2[L1(PhN=C−S)Ga(μ‐S)2Ga(S−C=NPh)L1] (6) and [L1(PhN=C−S)Ga(μ‐S)Ga(S−C=NPh)L1] (7). All the newly prepared compounds were characterized by elemental analysis, single‐crystal X‐ray diffraction, IR spectroscopy, NMR (3–9) or ESR spectroscopy (11), and DFT calculations.
Pressure‐Induced Spin‐Crossover Features at Variable Temperature Revealed by In Situ Synchrotron Powder X‐ray Diffraction
Authors: Tailleur Elodie , Marchivie Mathieu , Itié Jean‐Paul , Rosa Patrick , Daro Nathalie , Guionneau Phillippe
Published: July 2018

An accurate high‐pressure X‐ray diffraction investigation, at various temperatures, on a powder of a spin‐crossover (SCO) complex has allowed the rare deconvolution of the structural features of the high‐spin and low‐spin phases. As a result, the pressure dependence of the structural parameters of the high‐spin and low‐spin phases can be discussed independently in the pressure domain where both phases co‐exist within the powder. Consequently, crucial unprecedented information is given, such as the variation of bulk moduli with temperature, similar here in amplitude for both spin phases, the temperature‐dependence of the pressure‐induced SCO abruptness, the temperature dependence of the pressure at which SCO occurs, and arguments for a possible piezo‐hysteresis. Performed on the molecular complex [Fe(PM‐PeA)2(NCSe)2] (PM‐PeA=N‐(2′‐pyridylmethylene)‐4‐(phenylethynyl) aniline), this study reveals a pressure‐induced SCO at 0.16 GPa and demonstrates that, when increasing temperature, the pressure of transition increases linearly, the abruptness of the pressure‐induced SCO strongly increases, and the bulk moduli decrease.
Involvement of sonic hedgehog and notch signaling in regenerative neurogenesis in adult zebrafish optic tectum after stab injury
Authors: Ueda Yuto , Shimizu Yuki , Shimizu Nobuyuki , Ishitani Tohru , Ohshima Toshio
Published: July 2018

Unlike humans and other mammals, adult zebrafish have the superior capability to recover from central nervous system (CNS) injury. We previously found that proliferation of radial glia (RG) is induced in response to stab injury in optic tectum and that new neurons are generated from RG after stab injury. However, molecular mechanisms which regulate proliferation and differentiation of RG are not well known. In the present study, we investigated Shh and Notch signaling as potential mechanisms regulating regeneration in the optic tectum of adult zebrafish. We used Shh reporter fish and confirmed that canonical Shh signaling is activated specifically in RG after stab injury. Moreover, we have shown that Shh signaling promotes RG proliferation and suppresses their differentiation into neurons after stab injury. In contrast, Notch signaling was down‐regulated after stab injury, indicated by the decrease in the expression level of her4 and her6, a target gene of Notch signaling. We also found that inhibition of Notch signaling after stab injury induced more proliferative RG, but that inhibition of Notch signaling inhibited generation of newborn neurons from RG after stab injury. These results suggest that high level of Notch signaling keeps RG quiescent and that appropriate level of Notch signaling is required for generation of newborn neurons from RG. Under physiological condition, activation of Shh signaling or inhibition of Notch signaling also induced RG proliferation. In adult optic tectum of zebrafish, canonical Shh signaling and Notch signaling play important roles in proliferation and differentiation of RG in physiological and regenerative conditions.
A Unified Integral Equation Scheme for Doubly Periodic Laplace and Stokes Boundary Value Problems in Two Dimensions
Authors: Barnett Alex H. , Marple Gary R. , Veerapaneni Shravan , Zhao Lin
Published: July 2018

We present a spectrally accurate scheme to turn a boundary integral formulation for an elliptic PDE on a single unit cell geometry into one for the fully periodic problem. The basic idea is to use a small least squares solve to enforce periodic boundary conditions without ever handling periodic Green's functions. We describe fast solvers for the two‐dimensional (2D) doubly periodic conduction problem and Stokes nonslip fluid flow problem, where the unit cell contains many inclusions with smooth boundaries. Applications include computing the effective bulk properties of composite media (homogenization) and microfluidic chip design.

We split the infinite sum over the lattice of images into a directly summed “near” part plus a small number of auxiliary sources that represent the (smooth) remaining “far” contribution. Applying physical boundary conditions on the unit cell walls gives an expanded linear system, which, after a rank‐1 or rank‐3 correction and a Schur complement, leaves awell‐conditionedsquare system that can be solved iteratively using fast multipole acceleration plus a low‐rank term. We are rather explicit about the consistency and nullspaces of both the continuous and discretized problems. The scheme is simple (no lattice sums, Ewald methods, or particle meshes are required), allows adaptivity, and is essentially dimension‐ and PDE‐independent, so it generalizes without fuss to 3D and to other elliptic problems. In order to handle close‐to‐touching geometries accurately we incorporate recently developed spectral quadratures. We include eight numerical examples and a software implementation. We validate against high‐accuracy results for the square array of discs in Laplace and Stokes cases (improving upon the latter), and show linear scaling for up to 104randomly located inclusions per unit cell. © 2018 Wiley Periodicals, Inc.
The Equilibrium Measure for a Nonlocal Dislocation Energy
Authors: Mora Maria Giovanna , Rondi Luca , Scardia Lucia
Published: July 2018

In this paper we characterize the equilibrium measure for a nonlocal and anisotropic weighted energy describing the interaction of positive dislocations in the plane. We prove that the minimum value of the energy is attained by a measure supported on the vertical axis and distributed according to the semicircle law, a well‐known measure that also arises as the minimizer of purely logarithmic interactions in one dimension. In this way we give a positive answer to the conjecture that positive dislocations tend to form vertical walls. This result is one of the few examples where the minimizer of a nonlocal energy is explicitly computed and the only one in the case of anisotropic kernels. © 2018 Wiley Periodicals, Inc.
Heat Flow on Time‐Dependent Metric Measure Spaces and Super‐Ricci Flows
Authors: Kopfer Eva , Sturm Karl‐Theodor
Published: July 2018

We study the heat equation on time‐dependent metric measure spaces (as well as the dual and the adjoint heat equation) and prove existence, uniqueness, and regularity. Of particular interest are properties that characterize the underlying space as a super‐Ricci flow as previously introduced by the second author [51]. Our main result yields the equivalence of

dynamic convexity of the Boltzmann entropy on the (time‐dependent) L2‐Wasserstein space,

monotonicity of L2‐Kantorovich‐Wasserstein distances under the dual heat flow acting on probability measures (backward in time),

gradient estimates for the heat flow acting on functions (forward in time), and

a Bochner inequality involving the time‐derivative of the metric.

Moreover, we characterize the heat flow on functions as the unique forward EVI flow for the (time‐dependent) energy in L2‐Hilbert space and the dual heat flow on probability measures as the unique backward EVI~flow for the (time‐dependent) Boltzmann entropy in L2‐Wasserstein space.© 2018 Wiley Periodicals, Inc.
On the effects of allocation strategies for exascale computing systems with distributed storage and unified interconnects
Authors: Pascual Jose A. , Lant Joshua , Concatto Caroline , Attwood Andrew , Navaridas Javier , Luján Mikel , Goodacre John
Published: July 2018

The convergence between computing‐ and data‐centric workloads and platforms is imposing new challenges on how to best use the resources of modern computing systems. In this paper, we investigate alternatives for the storage subsystem of a novel exascale‐capable system with special emphasis on how allocation strategies would affect the overall performance. We consider several aspects of data‐aware allocation such as the effect of spatial and temporal locality, the affinity of data to storage sources, and the network‐level traffic prioritization for different types of flows. In our experimental set‐up, temporal locality can have a substantial effect on application runtime (up to a 10% reduction), whereas spatial locality can be even more significant (up to one order of magnitude faster with perfect locality). The use of structured access patterns to the data and the allocation of bandwidth at the network level can also have a significant impact (up to 20% and 17% reduction of runtime, respectively). These results suggest that scheduling policies exposing data‐locality information can be essential for the appropriate utilization of future large‐scale systems. Finally, we found that the distributed storage system we are implementing can outperform traditional SAN architectures, even with a much smaller (in terms of I/O servers) back‐end.
Density Functional Characterization of the 4f‐Relevant Electronic Transitions of Lanthanide‐Doped Lu2O3 Luminescence Materials
Authors: Meng Junling , Zhang Lifang , Yao Fen , Liu Xiaojuan , Meng Jian , Zhang Hongjie
Published: July 2018

Herein, we present a theoretical study on trivalent‐lanthanide‐substituted luminescence materials (Lu2O3 : Ln; with Ln=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) by using first‐principles calculations based on the Coulomb‐corrected density functional theory (DFT+U). Large‐scale calculations of electronic the structure are carried out with the goal of pinpointing the 4f‐relevant electronic transition rule and optical features of Lu2O3 : Ln systems. A characteristic double “zigzag” pattern for Ln3+ and Ln2+ energy levels is observed. Accordingly, four types of electric‐dipole allowed transition modes are predicted in the lanthanide‐doped Lu2O3 family, with Lu2O3 : Eu and Lu2O3 : Yb showing superior absorption features. Finally, this 4f‐controlled electronic transition image provides useful guidance for designing new luminescence materials with desired properties.
Building a Thermostable Metabolon for Facilitating Coenzyme Transport and In Vitro Hydrogen Production at Elevated Temperature
Authors: Chen Hui , Huang Rui , Kim Eui‐Jin , Zhang Yi‐Heng P. Job
Published: July 2018

To facilitate coenzyme transport and in vitro enzymatic hydrogen production, a multi‐enzyme metabolon comprising a miniscaffoldin containing three cohesins, a dockerin‐containing mutant dehydrogenase, a dockerin‐containing diaphorase, and a Histidine‐tagged (His‐tagged) NiFe hydrogenase was constructed. As the NiFe hydrogenase has very complicated structure and cannot be fused directly with a dockerin, a bifunctional peptide was designed. The bifunctional peptide, in which one terminus contains a modified dockerin binding the cohesin of the miniscaffoldin and the other, after chemical modification, binds the His‐tag of NiFe hydrogenase, enabled His‐tagged proteins to be integrated into the cohesin–dockerin‐based metabolon. The metabolon exhibited an initial reaction rate 4.5 times that of the enzyme cocktail at the same enzyme loading, which indicated enhanced coenzyme transport of the metabolon. However, this metabolon was unstable owing to the degradation of the miniscaffoldin at elevated temperature. Glutaraldehyde was used to cross‐link the metabolon for locking its spatial organization. The cross‐linked metabolon not only exhibited 2.5 times the reaction rate of the enzyme cocktail, but also retained its stability at 70 °C. The amount of hydrogen production catalyzed by the cross‐linked metabolon was nearly twice that of the metabolon without glutaraldehyde cross‐linking and four times that of the enzyme cocktail at 70 °C after 22 h of reaction.
Low‐Weight 3D Al2O3 Network as an Artificial Layer to Stabilize Lithium Deposition
Authors: Tian Ran , Feng Xiaoqian , Duan Huanan , Zhang Peng , Li Hua , Liu Hezhou , Gao Lian
Published: July 2018

Lithium metal has been regarded as an ideal anode for high‐energy‐density batteries. However, safety and efficiency concerns still linger due to dendrite formation, reactions between the liquid electrolyte and lithium, high resistance with lithium metal, and the weight of interface layer. A new nanometer‐thick, hollow, Al2O3 fiber network with an elastic and porous 3D structure has been prepared through an atomic‐layer deposition process by using cotton sacrificial templates. Through a comparison study of the lithium deposition behavior by employing artificial layers with different structures, the low‐weight 3D layer with lithiophilic properties overcomes the issues resulting from the 2D rigid Al2O3 layer and provides a low overpotential and dendrite‐free growth of lithium metal. Moreover, stable lithium deposition enables Li–Li symmetric cells with a 3D artificial layer to be stably cycled 300 times in carbonate‐based electrolyte, with superior rate capability, and with a LiNi1/3Co1/3Mn1/3O2 cathode.
The Effect of Organic Additives on the Activity and Selectivity of CO2 Electroreduction: The Role of Functional Groups
Authors: Xu Wenbin , Qiu Yanling , Zhang Taotao , Li Xianfeng , Zhang Huamin
Published: July 2018

Electrochemical reduction of CO2 (ERC) to useful chemicals is an environmentally and technologically significant process. The process is confronted with significant challenges to simultaneously enhance the catalyst activity and product selectivity. In this paper, the effects of organic additives on the ERC process were systematically investigated by using DFT to screen additives with different functional groups for enhanced activity and selectivity. In particular, the additives with −NH3+ and −SO3H groups had a remarkably positive effect on the ERC activity and hydrocarbon selectivity, which were predicted to impart a positive shift on onset potential of approximately 162 and 108 mV, respectively. Importantly, the additive can accelerate the electron transfer of the intermediate and tune the electronic structure of the catalyst surface, resulting in a clear deviation from transition‐metal scaling lines. Combining bonding energy of crucial intermediates with partial atomic charge analysis, we rationalized the negative effect of high concentration additives and confirmed the proposed electron transfer model. Furthermore, additive molecules containing functional groups with positive charges and maximizing the deviation from transition‐metal scaling lines are meaningful strategies to design and choose organic additives to enhance activity and selectivity of ERC.
Dissipative ion acoustic solitary waves in collisional, magneto‐rotating, non‐thermal electron–positron–ion plasma
Authors: Farooq M. , Mushtaq A. , Qasim J.
Published: July 2018

The linear and non‐linear dynamics of ion acoustic waves are investigated in three‐component magnetized plasma consisting of cold inertial ions and non‐thermal electrons and positrons. The non‐thermal components are modelled by the hybrid distribution, representing the combination of two (kappa and Cairn's) non‐thermal distributions. The relevant processes, including the slow rotation of plasma along the magnetic field axis and collision between ions and neutrals, are taken into consideration. It is shown that the non‐linear dynamics of the considered system are governed by the Zakharov–Kuznetsov equation in modified form. In the general dissipation regime, the effects of the two non‐thermal distributions on the solitary waves are compared. The effects of other plasma parameters, such as collisional and rotational frequency, are also discussed in detail.
Dual‐enrollment programs bring increased college enrollments and challenges
Authors: Hodges Dawn Z.
Published: July 2018

Dual enrollment is more popular than ever throughout the country. It has many benefits for students, parents, and institutions. Students can gain college credits or earn a credential before ever leaving high school. Parents can save a lot of money if their children take courses via dual enrollment. In many states, dual‐enrollment courses are free to high school students, so there is a great incentive to earn as much college credit as possible while still in high school. For institutions, dual‐enrollment programs create seamless pathways for students to enter colleges after high school graduation, plus the programs mean growth in enrollment. Some colleges are experiencing growth solely due to dual enrollment.
President shares 5 building blocks for success
Authors: McCarthy Claudine
Published: July 2018

CLEARWATER, FLORIDA — Colleges and universities face tenuous times full of daunting challenges, according to E. Gordon Gee, J.D., Ed.D. But in this atmosphere of havoc, higher ed officials must embrace the opportunity to establish building blocks for a havoc‐resistant future for higher education, he said at Stetson University's National Conference on Law and Higher Education, when he accepted the William A. Kaplin Award for Excellence in Higher Education Law & Policy Scholarship.
Assessing the role of ontogenetic movement in maintaining population structure in fish using otolith microchemistry
Authors: Wright Peter J. , Régnier Thomas , Gibb Fiona M. , Augley Julian , Devalla Sandhya
Published: July 2018

Identifying the mechanisms maintaining population structure in marine fish species with more than a single dispersing life stage is challenging because of the difficulty in tracking all life stages. Here, a two‐stage otolith microchemistry approach to examining life‐stage movement was adopted, tracking a year‐class from the juvenile to adult stage and inferring larval sources from clustering, in order to consider the mechanisms maintaining population structuring in North Sea cod. Clustering of near‐core chemistry identified four clusters, two of which had either a southern or northern affinity and were similar to juvenile edge chemistry. The other two clusters, common to the central North Sea, had intermediate chemical composition and may have reflected either larval mixing in this region or a lack of geographic heterogeneity in the elemental signature. From the comparison of whole juvenile and the corresponding component of adult otoliths, adults from the southern North Sea mostly recruited from adjacent nursery grounds. In contrast, many adults in the northern North Sea had a juvenile chemistry consistent with the Skagerrak and juveniles from the northern Skagerrak site had a near‐core chemistry consistent with the northern North Sea. Similarities in otolith chemistry were consistent with retention of early life stages at a regional level and also juvenile and adult fidelity. The links between the northern North Sea and Skagerrak indicate natal homing, which when considered in the context of genetic evidence is suggestive of philopatry. The approach used here should be useful in exploring the mechanisms underlying population structuring in other species with multiple dispersive life stages and calcified hard parts.
Local trampling disturbance effects on alpine plant populations and communities: Negative implications for climate change vulnerability
Authors: Chardon Nathalie Isabelle , Wipf Sonja , Rixen Christian , Beilstein Annabarbara , Doak Daniel Forest
Published: July 2018

Global change is modifying species communities from local to landscape scales, with alterations in the abiotic and biotic determinants of geographic range limits causing species range shifts along both latitudinal and elevational gradients. An important but often overlooked component of global change is the effect of anthropogenic disturbance, and how it interacts with the effects of climate to affect both species and communities, as well as interspecies interactions, such as facilitation and competition. We examined the effects of frequent human trampling disturbances on alpine plant communities in Switzerland, focusing on the elevational range of the widely distributed cushion plant Silene acaulis and the interactions of this facilitator species with other plants. Examining size distributions and densities, we found that disturbance appears to favor individual Silene growth at middle elevations. However, it has negative effects at the population level, as evidenced by a reduction in population density and reproductive indices. Disturbance synergistically interacts with the effects of elevation to reduce species richness at low and high elevations, an effect not mitigated by Silene. In fact, we find predominantly competitive interactions, both by Silene on its hosted and neighboring species and by neighboring (but not hosted) species on Silene. Our results indicate that disturbance can be beneficial for Silene individual performance, potentially through changes in its neighboring species community. However, possible reduced recruitment in disturbed areas could eventually lead to population declines. While other studies have shown that light to moderate disturbances can maintain high species diversity, our results emphasize that heavier disturbance reduces species richness, diversity, as well as percent cover, and adversely affects cushion plants and that these effects are not substantially reduced by plant–plant interactions. Heavily disturbed alpine systems could therefore be at greater risk for upward encroachment of lower elevation species in a warming world.
Stage duration distributions in matrix population models
Authors: Okuyama Toshinori
Published: July 2018

Matrix population models are a standard tool for studying stage‐structured populations, but they are not flexible in describing stage duration distributions. This study describes a method for modeling various such distributions in matrix models. The method uses a mixture of two negative binomial distributions (parametrized using a maximum likelihood method) to approximate a target (true) distribution. To examine the performance of the method, populations consisting of two life stages (juvenile and adult) were considered. The juvenile duration distribution followed a gamma distribution, lognormal distribution, or zero‐truncated (over‐dispersed) Poisson distribution, each of which represents a target distribution to be approximated by a mixture distribution. The true population growth rate based on a target distribution was obtained using an individual‐based model, and the extent to which matrix models can approximate the target dynamics was examined. The results show that the method generally works well for the examined target distributions, but is prone to biased predictions under some conditions. In addition, the method works uniformly better than an existing method whose performance was also examined for comparison. Other details regarding parameter estimation and model development are also discussed.
CHIIMP: An automated high‐throughput microsatellite genotyping platform reveals greater allelic diversity in wild chimpanzees
Authors: Barbian Hannah J. , Connell Andrew Jesse , Avitto Alexa N. , Russell Ronnie M. , Smith Andrew G. , Gundlapally Madhurima S. , Shazad Alexander L. , Li Yingying , Bibollet‐Ruche Frederic , Wroblewski Emily E. , Mjungu Deus , Lonsdorf Elizabeth V. , Stewart Fiona A. , Piel Alexander K. , Pusey Anne E. , Sharp Paul M. , Hahn Beatrice H.
Published: July 2018

Short tandem repeats (STRs), also known as microsatellites, are commonly used to noninvasively genotype wild‐living endangered species, including African apes. Until recently, capillary electrophoresis has been the method of choice to determine the length of polymorphic STR loci. However, this technique is labor intensive, difficult to compare across platforms, and notoriously imprecise. Here we developed a MiSeq‐based approach and tested its performance using previously genotyped fecal samples from long‐term studied chimpanzees in Gombe National Park, Tanzania. Using data from eight microsatellite loci as a reference, we designed a bioinformatics platform that converts raw MiSeq reads into locus‐specific files and automatically calls alleles after filtering stutter sequences and other PCR artifacts. Applying this method to the entire Gombe population, we confirmed previously reported genotypes, but also identified 31 new alleles that had been missed due to sequence differences and size homoplasy. The new genotypes, which increased the allelic diversity and heterozygosity in Gombe by 61% and 8%, respectively, were validated by replicate amplification and pedigree analyses. This demonstrated inheritance and resolved one case of an ambiguous paternity. Using both singleplex and multiplex locus amplification, we also genotyped fecal samples from chimpanzees in the Greater Mahale Ecosystem in Tanzania, demonstrating the utility of the MiSeq‐based approach for genotyping nonhabituated populations and performing comparative analyses across field sites. The new automated high‐throughput analysis platform (available at https://github.com/ShawHahnLab/chiimp) will allow biologists to more accurately and effectively determine wildlife population size and structure, and thus obtain information critical for conservation efforts.
Genome‐wide SNP analysis unveils genetic structure and phylogeographic history of snow sheep (Ovis nivicola) populations inhabiting the Verkhoyansk Mountains and Momsky Ridge (northeastern Siberia)
Authors: Dotsev Arsen V. , Deniskova Tatiana E. , Okhlopkov Innokentiy M. , Mészáros Gabor , Sölkner Johann , Reyer Henry , Wimmers Klaus , Brem Gottfried , Zinovieva Natalia A.
Published: July 2018

Insights into the genetic characteristics of a species provide important information for wildlife conservation programs. Here, we used the OvineSNP50 BeadChip developed for domestic sheep to examine population structure and evaluate genetic diversity of snow sheep (Ovis nivicola) inhabiting Verkhoyansk Range and Momsky Ridge. A total of 1,121 polymorphic SNPs were used to test 80 specimens representing five populations, including four populations of the Verkhoyansk Mountain chain: Kharaulakh Ridge–Tiksi Bay (TIK, n = 22), Orulgan Ridge (ORU, n = 22), the central part of Verkhoyansk Range (VER, n = 15), Suntar‐Khayata Ridge (SKH, n = 13), and Momsky Ridge (MOM, n = 8). We showed that the studied populations were genetically structured according to a geographic pattern. Pairwise FST values ranged from 0.044 to 0.205. Admixture analysis identified K = 2 as the most likely number of ancestral populations. A Neighbor‐Net tree showed that TIK was an isolated group related to the main network through ORU. TreeMix analysis revealed that TIK and MOM originated from two different ancestral populations and detected gene flow from MOM to ORU. This was supported by the f3 statistic, which showed that ORU is an admixed population with TIK and MOM/SKH heritage. Genetic diversity in the studied groups was increasing southward. Minimum values of observed (Ho) and expected (He) heterozygosity and allelic richness (Ar) were observed in the most northern population—TIK, and maximum values were observed in the most southern population—SKH. Thus, our results revealed clear genetic structure in the studied populations of snow sheep and showed that TIK has a different origin from MOM, SKH, and VER even though they are conventionally considered a single subspecies known as Yakut snow sheep (Ovis nivicola lydekkeri). Most likely, TIK was an isolated group during the Late Pleistocene glaciations of Verkhoyansk Range.
Diagnosing and grading heart failure with tomographic perfusion lung scintigraphy: validation with right heart catheterization
Authors: Jögi Jonas , Al‐Mashat Mariam , Rådegran Göran , Bajc Marika , Arheden Håkan
Published: July 2018

Aims

Pulmonary congestion remains a diagnostic challenge in patients with heart failure (HF). The recommended method, chest X‐ray (CXR), lacks in accuracy, whereas quantitative tomographic lung scintigraphy [ventilation/perfusion single‐photon emission computed tomography (V/P SPECT)] has shown promising results but needs independent validation. The aim of this study is to evaluate V/P SPECT as a non‐invasive method to assess and quantify pulmonary congestion in HF patients, using right heart catheterization as reference method. The secondary objective was to investigate the performance of V/P SPECT in the clinical setting compared with CXR.

Methods and results

Forty‐six consecutive patients with HF that were under consideration for heart transplantation were studied prospectively. All participants were examined with V/P SPECT, CXR, and right heart catheterization. Pulmonary artery wedge pressure served as reference method. Quantitative perfusion gradients were derived from V/P SPECT images. Ventilation/perfusion single‐photon emission computed tomography images were also assessed both by expert readers and clinical nuclear medicine physicians. Expert readers correctly identified 87% of all patients with an elevated pulmonary artery wedge pressure > 15 mmHg. The average sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for V/P SPECT assessed by the expert readers were 87%, 72%, 85%, and 75%, respectively. In the clinical nuclear medicine setting, V/P SPECT had 87% sensitivity, 63% specificity, 81% PPV, and 71% NPV. Clinically, V/P SPECT outperformed CXR, which had 27% sensitivity, 75% specificity, 67% PPV, and 35% NPV.

Conclusions

Ventilation/perfusion single‐photon emission computed tomography can be used as a non‐invasive method to diagnose and quantify pulmonary congestion in patients with HF and is more accurate than CXR in diagnosing pulmonary congestion in the clinical setting.
Physical and Electrochemical Modulation of Polyoxometalate Ionic Liquids via Organic Functionalization
Authors: Kibler Alexander J. , Martín Carmen , Cameron Jamie M. , Rogalska Agata , Dupont Jairton , Walsh Darren A. , Newton Graham N.
Published: July 2018

The synthesis and characterization of two new organic/inorganic hybrid polyoxometalate ionic liquids (POM‐ILs) is described. The POM‐ILs were formed by pairing bulky trihexyl(tetradecyl)phosphonium cations [THTP]+ with organosiloxane and organophosphonate‐functionalized Keggin‐type POMs [PW11O39(SiPh)2O]3– and [PW11O39{P(O)Ph}2]3–. The functionalized POM‐ILs were found to be more thermally stable than their molecular precursors and comparison of their electrochemical properties showed that the tunable electronic structures of the POM anions determined the redox chemistry of the hybrid materials.
Low‐complexity heuristics to beam selection and rate adaptation in sparse massive MIMO systems
Authors: Valduga Samuel T. , Deneire Luc , Aparicio‐Pardo Ramon , de Almeida André L. F. , Maciel Tarcisio F. , Mota João C. M.
Published: July 2018

In this work, we propose a novel formulation for a precoder design considering practical rate assignment based on the modulation and coding scheme of the long‐term evolution table, beam selection, and power optimization, which exploits the geometric sparsity of the multiuser massive multiple‐input–multiple‐output channel. We consider two different channel models and provide an optimal solution for the joint beam selection and power optimization as well as a heuristic using Lagrangian relaxation. Assuming knowledge of the beamspace channel, the beamspace precoder consists in selecting and optimizing the power of the beams steered to the user equipments (UEs) in order to maximize the signal‐to‐interference‐plus‐noise ratio at the UE. Furthermore, we propose three additional simple heuristics with low complexity. For these three heuristics, we solve the problem in two steps: (1) selection of beams based on the maximal ratio transmission principle and (2) power allocation per UE. Simulation results show that our optimal solution can achieve a better performance than the zero‐forcing beamforming scheme in the high‐sparsity scenarios. Besides, compared to the linear maximal ratio transmission precoder, the proposed low‐complexity heuristics improve the performance under a scenario with channel sparsity.
A Slope Right‐angle Turn Applied in the Flow Channel Promotes Water Management in Proton Exchange Membrane Fuel Cells
Authors: Liu H. C. , Tan J. , Cheng L. S. , Yang W. M.
Published: July 2018

Effective water removal and transport in the flow field is significantly important to the critical water management in proton exchange membrane fuel cells (PEMFCs). In this work, a slope turn was proposed in the hydrophobic channel of the multi‐serpentine flow field, and the transport and dynamics of water in the modified flow channel were numerically investigated with the volume‐of‐fluid method. The simulation results indicated that, with the presence of the slope turn, the water droplet can be effectively detached from the surface of the gas diffusion layer although the channel walls are hydrophobic. Meanwhile, the hydrophobic channel walls are beneficial to decrease interfacial resistance of water transport, avoiding water accumulation in the flow channel. The wall contact angle, slope angle and gas flow velocity are three important factors which significantly affect water behavior and pressure drop in the flow channel. For considered cases in this work, the appropriate wall contact angle, slope angle, and gas flow velocity were proved to be 140°, 110°, and higher than 2 m s−1, respectively.
MicroRNA Sequencing Identifies a Serum MicroRNA Panel, Which Combined With Aspartate Aminotransferase to Platelet Ratio Index Can Detect and Monitor Liver Disease in Pediatric Cystic Fibrosis
Authors: Calvopina Diego A. , Chatfield Mark D. , Weis Anna , Coleman Miranda A. , Fernandez‐Rojo Manuel A. , Noble Charlton , Ramm Louise E. , Leung Daniel H. , Lewindon Peter J. , Ramm Grant A.
Published: July 2018

Cystic fibrosis (CF)‐associated liver disease (CFLD) is a hepatobiliary complication of CF. Current diagnostic modalities rely on nonspecific assessments, whereas liver biopsy is the gold standard to assess severity of fibrosis. MicroRNAs (miRNAs) regulate liver disease pathogenesis and are proposed as diagnostic biomarkers. We investigated the combined use of serum miRNAs and aspartate aminotransferase (AST) to platelet ratio (APRI) to diagnose and assess CFLD severity. This was a cross‐sectional cohort study of the circulatory miRNA signature of 124 children grouped by clinical, biochemical, and imaging assessments as follows: CFLD (n = 44), CF patients with no evidence of liver disease (CFnoLD; n = 40), and healthy controls (n = 40). Serum miRNAs were analyzed using miRNA sequencing (miRNA‐Seq). Selected differentially expressed serum miRNA candidates were further validated by qRT‐PCR and statistical analysis performed to evaluate utility to predict CFLD and fibrosis severity validated by liver biopsy, alone or in combination with APRI. Serum miR‐122‐5p, miR‐365a‐3p, and miR‐34a‐5p levels were elevated in CFLD compared to CFnoLD, whereas miR‐142‐3p and let‐7g‐5p were down‐regulated in CFLD compared to CFnoLD. Logistic regression analysis combining miR‐365a‐3p, miR‐142‐3p, and let‐7g‐5p with APRI showed 21 times greater odds of accurately predicting liver disease in CF with an area under the receiver operating characteristics curve (AUROC) = 0.91 (sensitivity = 83%, specificity = 92%; P < 0.0001). Expression levels of serum miR‐18a‐5p were correlated with increasing hepatic fibrosis (HF) stage in CFLD (rs = 0.56; P < 0.0001), showing good diagnostic accuracy for distinguishing severe (F3‐F4) from mild/moderate fibrosis (F0‐F2). A unit increase of miR‐18a‐5p showed a 7‐fold increased odds of having severe fibrosis with an AUROC = 0.82 (sensitivity = 93%, specificity = 73%; P = 0.004), indicating its potential to predict fibrosis severity. Conclusion: We identified a distinct circulatory miRNA profile in pediatric CFLD with potential to accurately discriminate liver disease and fibrosis severity in children with CF.
Heat Shock Protein 90α–Dependent B‐Cell‐2–Associated Transcription Factor 1 Promotes Hepatocellular Carcinoma Proliferation by Regulating MYC Proto‐Oncogene c‐MYC mRNA Stability
Authors: Zhou Xueqiong , Wen Ying , Tian Ye , He Meiling , Ke Xiangyu , Huang Zhizhou , He Yangfan , Liu Lixia , Scharf Annette , Lu Meiting , Zhang Guowei , Deng Yaotang , Yan Yuxia , Mayer Matthias P. , Chen Xuemei , Zou Fei
Published: July 2018

B‐cell lymphoma 2 (Bcl‐2)‐associated transcription factor 1 (Bclaf1) is known to be involved in diverse biological processes, but, to date, there has been no evidence for any functional role of Bclaf1 in hepatocellular carcinoma (HCC) progression. Here, we demonstrate that Bclaf1 is frequently up‐regulated in HCC and that Bclaf1 up‐regulation is associated with Edmondson grade, lower overall survival rates, and poor prognosis. Overexpression of Bclaf1 in HCC cell lines HepG2 and Huh7 promoted proliferation considerably, whereas Bclaf1 knockdown had the opposite effect. Xenograft tumors grown from Bclaf1 knockdown Huh7 cells had smaller tumor volumes than tumors grown from control cells. Furthermore, our study describes MYC proto‐oncogene (c‐Myc) as a downstream target of Bclaf1, given that Bclaf1 regulates c‐MYC expression posttranscriptionally by its RS domain. To exert this function, Bclaf1 must interact with the molecular chaperone, heat shock protein 90 alpha (Hsp90α). In HCC tissue samples, Hsp90α levels were also increased significantly and Hsp90α‐Bclaf1 interaction was enhanced. Bclaf1 interacts with the C‐terminal domain of Hsp90α, and this interaction is disrupted by the C‐terminal domain inhibitor, novobiocin (NB), resulting in proteasome‐dependent degradation of Bclaf1. Moreover, NB‐induced disruption of Hsp90α‐Bclaf1 interaction dampened the production of mature c‐MYC mRNA and attenuated tumor cell growth in vitro and in vivo. Conclusion: Our findings suggest that Bclaf1 affects HCC progression by manipulating c‐MYC mRNA stability and that the Hsp90α/Bclaf1/c‐Myc axis might be a potential target for therapeutic intervention in HCC.
Personality characteristics that are valued in teams: Not always “more is better”?
Authors: Curşeu Petru Lucian , Ilies Remus , Vîrgă Delia , Maricuţoiu Laurenţiu , Sava Florin A.
Published: July 2018

This study investigates the relationships between personality traits and contributions to teamwork that are often assumed to be linear. We use a theory‐driven approach to propose that extraversion, agreeableness and conscientiousness have inverted U‐shaped relationships with contributions to teamwork. In a sample of 220 participants asked to perform a creative task in teams, we found that extraversion, agreeableness and conscientiousness were curvilinearly associated with peer‐rated contributions to teamwork in such a way that the associations were positive, with a decreasing slope, up to a peak, and then they became negative as personality scores further increased. We replicated the results concerning the non‐linear association between extraversion, conscientiousness and peer‐rated contributions to teamwork in a sample of 314 participants engaged in a collaborative learning exercise. Our results support recent claims and empirical evidence that explorations of personality–work‐related behaviours relationships should move beyond the linearity assumptions. We conclude by discussing the implications of our research for personnel selection.
Role of exosomal competing endogenous RNA in patients with hepatocellular carcinoma
Authors: Abd El Gwad Asmaa , Matboli Marwa , El‐Tawdi Ahmed , Habib Eman K. , Shehata Hanan , Ibrahim Doaa , Tash Fathy
Published: July 2018

Recent research has tried to use exosomal RNAs (coding and noncoding) as potential diagnostic markers for hepatocellular carcinoma (HCC). Initially, by using bioinformatics, we selected an HCC‐exosomal RNA‐based biomarker panel. The choice of this panel depends on the integration of Ras‐related in brain (RAB11A) gene expression and its competing endogenous network. This network includes long noncoding RNA RP11‐513I15.6 (lncRNA‐RP11‐513I15.6) and microRNA‐1262 (miR‐1262). Secondly, we tried to validate the expression of this network in the sera of 60 patients with HCC in comparison with 42 chronic hepatitis C virus‐infected patients and 18 healthy controls. Then we assessed the diagnostic efficiency of this panel using a receiver operating characteristic curve analysis. The panel of 3 exosomal RNA‐based biomarkers (lncRNA‐RP11‐513I15.6, miR‐1262, and RAB11A) showed excellent sensitivity and specificity in discriminating patients with HCC from patients with chronic hepatitis C virus and healthy controls. Among these 3 RNAs, serum RAB11A mRNA was the most independent prognostic factor. The selected circulatory exosomal RNA‐based biomarker panel showed its ability to be used as a diagnostic and prognostic biomarker tool for HCC. Moreover, these biomarkers could be therapeutic targets.
Feasibility of using ultra‐low pulse rate fluoroscopy during routine diagnostic coronary angiography
Authors: Badawy Mohamed Khaldoun , Scott Matthew , Farouque Omar , Horrigan Mark , Clark David J. , Chan Robert K.
Published: July 2018

Introduction

Coronary angiogram, while a powerful diagnostic tool in coronary artery disease, is not without an associated risk from ionising radiation. There are a number of factors that influence the amount of radiation the patient receives during the procedure, some of which are under the control of the operator. One of these is an adjustment of the fluoroscopic pulse rate. This study aims to assess the feasibility of using ultra‐low pulse rate (3 pulses per second(pps)) fluoroscopy during routine diagnostic coronary angiogram procedures and the effect it has on fluoroscopy time, diagnostic clarity and radiation dose.

Methods

A retrospective study of three operators each undertaking 50 coronary angiogram procedures was performed. One of the operators used a pulse rate of 3 pps and 6 pps for fluoroscopic screening while the control groups used the standard 10 pps mode utilised at this centre.

Results

Results demonstrated no reduction of diagnostic clarity, up to a 58% reduction in Dose Area Product and no increase in fluoroscopy time with the 3 pps setting.

Conclusions

Findings from this pilot study suggest that utilisation of ultra‐low pulse rate fluoroscopy in routine transfemoral diagnostic coronary angiography in the catheterisation laboratory is feasible.
Programmed cell death‐1 3′‐untranslated region polymorphism is associated with spontaneous clearance of hepatitis B virus infection
Authors: Chihab Hajar , Jadid Fatima‐Zahra , Foka Pelagia , Zaidane Imane , El Fihry Raouia , Georgopoulou Urania , Marchio Agnes , Elhabazi Abdellah , Chair Mohammed , Pineau Pascal , Ezzikouri Sayeh , Benjelloun Soumaya
Published: July 2018

Hepatitis B virus (HBV)‐specific CD8+ T cells play an important role in the clearance of HBV infection. Programmed cell death‐1 (PD‐1), an immunosuppressive molecule that regulates T‐cell activation and peripheral immune tolerance, is increasingly shown to influence the outcome of HBV infection. rs10204525, a single‐nucleotide polymorphism in the 3′‐untranslated region (3′‐UTR) of PD‐1, has been associated with susceptibility and disease progression of chronic HBV infection in far‐eastern patients. The aim of our study was to assess the impact of rs10204525 variation on HBV infection in Moroccan patients. A total of 236 patients with chronic HBV infection and 134 individuals with spontaneous HBV resolution were genotyped using a Taqman assay. In addition, PD‐1 mRNA expression in peripheral blood nuclear cells was determined by quantitative reverse‐transcription polymerase chain reaction. We found that the AA genotype is protective (odds ratio, 0.43; 95% confidence interval, 0.19 to 0.97; P = 0.038) against HBV infection. Interestingly, PD‐1 messenger RNA (mRNA) expression analysis has revealed that chronic HBV carriers with GG and GA displayed higher levels of PD‐1 mRNA compared with corresponding genotypes in resolved subjects (P = 0.031 and 0.014, respectively). Our data suggest that Mediterranean HBV‐infected patients carrying PD‐1 GG and GA genotypes at rs10204525 have high PD‐1 mRNA expression and may be more prone to installation of chronicity.
Fate of phosphorus in soil during a long‐term fertilization experiment in Finland
Authors: Rodríguez Ignacio González , Yli-Halla Markku , Jaakkola Antti
Published: July 2018

Accumulation and depletion of soil phosphorus (P) was studied in a long‐term (37 y) field experiment in Southern Finland. The loam soil had a high pH (7.5–7.7) due to an earlier liming. Spring barley, spring wheat, oat, and ryegrass, grown in rotation, were annually fertilized with 0, 32, or 67 kg P ha−1 y−1 (P0, P1, and P2K) and sufficient N. The average dry matter grain yield 2,600 kg ha−1 of the P0 plots increased by about 500 kg ha−1 at P1 treatment and another 600 kg ha−1 by P2K. Soil samples were collected in 1978 (beginning), 1995, 2005, and 2015. According to the Chang and Jackson sequential extraction, the P2K and P1 treatments increased the inorganic soil P by 732 and 32 kg P ha −1 in 37 years, respectively, while the P0 plots were depleted by –459 kg P ha −1. The P2K treatment increased all four P fractions, extracted with NH4Cl (easily soluble), NH4F (Al‐P), NaOH (Fe‐P), and H2SO4 (Ca‐P). Continuous depletion (P0) decreased the NH4Cl‐P and NH4F‐P pools, NaOH‐P and H2SO4‐P pools remaining stable. None of the P pools changed significantly at P1. The remarkable gap between the measured change and the balance for the P2K and P1 treatments cannot be explained solely by lateral soil movement, meaning that a significant proportion of the applied P was lost either in surface runoff or transported below the investigated depth of 40 cm. Despite large P applications, the degree of P saturation reached only 20% in the P2K topsoil, assuming a 50% reactivity of Fe and Al oxides. As derived from sorption isotherms, a high EPC0 (i.e., equilibrium P concentration at zero net P sorption or desorption) of 1.30 mg L−1 had been built up in the P2K treatment, while in the P1 treatment EPC0 (0.33 mg L−1) had remained unchanged and P depletion (P0) had caused a decrease to 0.12 mg L−1. These results demonstrate that P sorption and desorption properties respond strongly to both P fertilization and null fertilization treatments and that in a long‐term field experiment only a low proportion of the residual fertilizer P can be recovered from soil.