bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of modeling in drawing up guidelines for the exploitation of the Khankala geothermal field (Chechen Republic)
Authors: Farkhutdinov A. M. , Goblet P. , Farkhutdinov I. M. , Cherkasov S. V. , Ismagilov R. A. , Khairulina L. A.
Published: December 2018

Nowadays, geothermal waters have become an important form of energy and many researchers have put to the forefront the issue of “sustainability” of the geothermal reservoir development. Reinjection of the used fluid during exploitation allows minimizing the possible negative effect on the environment and maintaining the reservoir pressure and therefore the initial high flow rates. However, it has a major disadvantage—a gradual temperature decrease in an aquifer, which needs to be taken into account. The most effective methods assessing this disadvantage are based on numerical modeling, which has been actively implemented in all areas of science. In the current paper, mathematical modeling is applied for the Khankala geothermal field in the Chechen Republic to forecast changes in the temperature regime of the resource and define the optimal exploitation scenario to achieve its sustainable development.
Comprehensive evaluation of supercritical power cycle system using non-azeotropic mixtures driven by medium-temperature solar heat source
Authors: Gu Yujiong , Geng Zhi
Published: December 2018

Aimed at the medium-temperature solar energy heat source, the use of low-boiling binary non-azeotropic organic mixtures as the supercritical cycle working fluids to generate power was put forward. On the premises of meeting the requirements of thermal property, safety, and economic efficiency, 8 working fluids combining R245fa with R152a according to different mass ratios were used and the supercritical thermal system mathematical model was established based on the first and second laws of thermodynamics. The cycle characteristics were contrasted from the multi-angle aspects including seven indices like thermal efficiency, exergy efficiency, and so on. Considering various factors, the multi-index comprehensive evaluation model of energy efficiency was constructed by using the analytic hierarchy process method. Through simulation calculations, the results show that properly increasing the proportion of R245fa promotes effective improvement of the supercritical cycle characteristics and working fluid R245fa/R152a(0.96/0.04) can improve the indexes including net output power, economy, and environmental performance of the system. The proposed one has the optimal evaluation index value among the candidates.
On the uniqueness of L∞ bootstrap: Quasi-isomorphisms are Seiberg-Witten maps
Authors: Blumenhagen Ralph , Brinkmann Max , Kupriyanov Vladislav , Traube Matthias
Published: December 2018

In the context of the recently proposed L∞ bootstrap approach, the question arises whether the so constructed gauge theories are unique solutions of the L∞ relations. Physically, it is expected that two gauge theories should be considered equivalent if they are related by a field redefinition described by a Seiberg-Witten map. To clarify the consequences in the L∞ framework, it is proven that Seiberg-Witten maps between physically equivalent gauge theories correspond to certain relations of quasi-isomorphisms of the underlying L∞ algebras. The proof suggests an extension of the definition of a Seiberg-Witten map to the closure conditions of two gauge transformations and the dynamical equations of motion.
A novel method and system for calibrating the spring constant of atomic force microscope cantilever based on electromagnetic actuation
Authors: Tian Yanling , Zhou Chongkai , Wang Fujun , Zhang Jinyi , Guo Zhiyong , Zhang Dawei
Published: December 2018

It is crucial to calibrate atomic force microscope (AFM) cantilevers for the development and further applications of AFM in precision engineering such as nanonewton force measurement. This paper presents a novel approach to calibrate the spring constant of an AFM cantilever based on electromagnetic actuation and null position measurement. According to the method, a calibration system was designed. In order to optimize the static and dynamic characteristics of the calibration system, the analytical models for the electromagnetic force and the suspension mechanism stiffness have been developed. Finite element analysis has been utilized to further investigate the precision of analytical modeling. The null position measurement method was utilized to monitor the deformation of the flexible beam, and then the deformation was compensated by the electromagnetic force. Experiments were carried out based on the developed prototype, and the results show that the electromagnetic force conversion rate is 40.08 µN/mA. Finally, a typical AFM cantilever was calibrated and the spring constant is (30.83 ± 0.24) N/m. The uncertainty of the proposed null position measurement method is better than 0.78%, which verifies the effectiveness and feasibility of the calibration method and system.
Quantitative comparison of adaptive sampling methods for protein dynamics
Authors: Hruska Eugen , Abella Jayvee R. , Nüske Feliks , Kavraki Lydia E. , Clementi Cecilia
Published: December 2018

Adaptive sampling methods, often used in combination with Markov state models, are becoming increasingly popular for speeding up rare events in simulation such as molecular dynamics (MD) without biasing the system dynamics. Several adaptive sampling strategies have been proposed, but it is not clear which methods perform better for different physical systems. In this work, we present a systematic evaluation of selected adaptive sampling strategies on a wide selection of fast folding proteins. The adaptive sampling strategies were emulated using models constructed on already existing MD trajectories. We provide theoretical limits for the sampling speed-up and compare the performance of different strategies with and without using some a priori knowledge of the system. The results show that for different goals, different adaptive sampling strategies are optimal. In order to sample slow dynamical processes such as protein folding without a priori knowledge of the system, a strategy based on the identification of a set of metastable regions is consistently the most efficient, while a strategy based on the identification of microstates performs better if the goal is to explore newer regions of the conformational space. Interestingly, the maximum speed-up achievable for the adaptive sampling of slow processes increases for proteins with longer folding times, encouraging the application of these methods for the characterization of slower processes, beyond the fast-folding proteins considered here.
Optical bandgap tuning of ferroelectric semiconducting BiFeO3-based oxide perovskites via chemical substitution for photovoltaics
Authors: Jiang Yinglong , Ning Huanpo , Yu Jian
Published: December 2018

Ferroelectrics exhibit bulk photovoltaic effect, of which spontaneous electric polarization separates photo-excited carriers and results in above-bandgap open-circuit voltage. Compared with organometal halide perovskites, ferroelectric oxide perovskites are much more stable in a wide range of mechanical, chemical and thermal conditions and able to fabricate using low-cost facilities. The bottlenecks for ferroelectric photovoltaic applications are their poor optical absorption of visible light and high electric resistivity owing to wide bandgap. In this work, bandgap of BiFeO3-based oxide perovskites was judiciously tuned in a range of 1.10-2.06 eV through B-site chemistry, which makes ferroelectric semiconducting oxide perovskites feasible for photovoltaic solar cell applications with wide light absorption and high efficient energy conversion. In particular, La and Mn co-substituted BiFeO3 solid solution exhibits a narrow direct bandgap around 1.20 eV, which extends photon absorptions over ∼80% sunlight spectrum covering ultraviolet-visible-infrared region and increases electrical conductivity (σdc) up to about 10-5 S/m. The electronic subshell configuration, the reduced mass of unit cell, and the tolerant factor/octahedral factor related to ionic size were attempted as descriptors to classify and map out the relationship between compositions and bandgap properties of BiFeO3-based oxide perovskites. This essay paves the road for ferroelectric semiconducting oxide perovskites to make photovoltaic solar cells with power conversion efficiency promising beyond the Shockley-Queisser limit of conventional p-n junction solar cells.
A novel Π-type linear ultrasonic motor driven by a single mode
Authors: Jian Yue , Yao Zhiyuan , Zhang Bailiang , Liu Zhen
Published: December 2018

In order to meet the demand of a linear ultrasonic motor with large thrust in narrow space, a novel Π-type linear ultrasonic motor with double driving feet is proposed. In this paper, the structure of a stator is designed. The working mode and structure size are determined by finite element simulation. To amplify the amplitude of driving foot, an optimization design for the stator is performed. After that, a novel pre-load device that separates from the stator is put forward, which can not only improve the output but also help to improve the operation stability and prolong the life of motor. Additionally, a prototype of the proposed motor with the novel pre-load device was fabricated and the performance tests were implemented. The experimental results show that the suggested motor has structural stability and high dynamic performance, such as a no-load speed of 273 mm/s and 238 mm/s in two directions, corresponding to a maximal thrust of 80 N and 110 N.
Exploring wide bandgap metal oxides for perovskite solar cells
Authors: Shin S. S. , Lee S. J. , Seok S. I.
Published: December 2018

The heterojunction formed when wide bandgap oxides come into contact with perovskite solar cells is essential for high efficiency as it minimizes charge leakage along with charge separation and charge transfer. Therefore, the electrical and optical properties of wide bandgap oxides, including the bandgap, charge mobility, and energy level, directly determine the efficiency of perovskite solar cells. In addition, the surface properties of the wide bandgap oxide act as an important factor that determines the efficiency through the wettability and penetration of the precursor solution during perovskite layer deposition and long-term stability through the intimate interfacial bonding with the perovskite. Although a great variety of wide bandgap oxides are known, the number that can be used for perovskite solar cells is considerably reduced in view of the limitations that the light absorber (here, perovskite) for solar cells is fixed, and the oxides must be uniformly coated at low temperature onto the substrate. Herein, a review of the results from several broad bandgap oxides used in perovskite solar cells is presented, and a direction for discovering new photoelectrodes is proposed.
Transient evolution of the heat transfer and the vapor film thickness at the drop impact in the regime of film boiling
Authors: Castanet G. , Chaze W. , Caballina O. , Collignon R. , Lemoine F.
Published: December 2018

When a drop impinges onto a wall heated above the Leidenfrost temperature, a very thin vapor film is formed at the interface between the liquid and the solid substrate. This vapor layer modifies the impact behavior of the drop and induces a significant decrease in heat transfer. A model is proposed for the growth of this vapor layer and its resistance to the heat transfer. The main assumptions are as follows: (i) a uniform but time varying thickness of the vapor film, (ii) a quasi-steady Poiseuille flow inside the vapor film, and (iii) a constant wall temperature. Heat energy and momentum balances are employed to obtain an ordinary differential equation describing the evolution of the vapor film thickness during the drop impact. For droplets injected at a temperature sufficiently lower than the saturation temperature, this equation predicts that the impact velocity has no influence on the thickness of the vapor film. This latter is solely governed by the local heat flux transferred to the liquid, which predominates over the heat flux used for liquid evaporation. An accurate description of the droplet heating is therefore required to complement this model. As an attempt, this description is based upon a one-dimensional analysis, which includes some effects due to the complex fluid flow inside the spreading droplet. Finally, the theoretical model is validated against experiments dealing with millimeter-sized ethanol droplets. Two optical measurement techniques, based on laser-induced fluorescence and infrared thermography, are combined to characterize the heat transfer as well as the thickness of the vapor film.
Pressure effects on the inductive loop, mixed conduction, and photoresponsivity in formamidinium lead bromide perovskite
Authors: Ou Tianji , Ma Xinjun , Yan Huacai , Shen Wenshu , Liu Hao , Han Yonghao , Liu Xizhe , Liu Cailong , Ma Yanzhang , Gao Chunxiao
Published: December 2018

Further efficiency boost of organic-inorganic perovskite solar cells is hampered by limited knowledge on ion migration, inductive loops, and the relationship between structures and properties in organometal halide perovskites. In this work, in situ alternating current impedance spectroscopy measurements on CH(NH2)2PbBr3 (FAPbBr3) have been carried out under high pressure up to 4.8 GPa. The inductive loop has been discovered at low frequencies and can be tuned dramatically by applying pressure, which is attributed to large FA ion migration in FAPbBr3. Two discontinuous changes are observed in both ionic and electronic resistances around phase transition pressure. The pressure dependent photoresponse of FAPbBr3 has also been studied by in situ photocurrent measurements under high pressure up to 3.8 GPa. It indicates that the photocurrent of FAPbBr3 can be enhanced remarkably at 1.3 GPa and the largest photocurrent value in FAPbBr3 is nearly 10 times larger than that in CH3NH3PbBr3 and about 3 times larger than that in CH3NH3PbI3.
The three-dimensional impulse response of a boundary layer to different types of wall excitation
Authors: Sundaram Prasannabalaji , Sengupta Tapan K. , Bhaumik Swagata
Published: December 2018

Here we report a study of the physical mechanism behind the creation of perturbation of a boundary layer by direct numerical simulation (DNS) of an incompressible Navier-Stokes equation (NSE) that leads to eventual three-dimensional (3D) transition. By considering two different types of impulsive wall-excitations which are similar to dip-slip and strike-slip events in the seismological terminology for a zero pressure gradient (ZPG) boundary layer, we show that initial events and the evolution of the resultant wave-packet bear a close resemblance with the physical mechanism for the creation of tsunamis. This is due to the significant differences in the characteristics and dynamics of the wall-bounded and oceanic boundary layer at deep-ocean. Here we particularly seek out the impulse response of a ZPG boundary layer as demonstrated recently in the work of S. Bhaumik and T. K. Sengupta [“Impulse response and spatio-temporal wave-packets: The common feature of rogue waves, tsunami, and transition to turbulence,” Phys. Fluids 29, 124103 (2017)], by considering a specific boundary motion similar to dip-slip events for the creation of tsunamis. The precursor of flow transition, noted as the spatiotemporal wave front, has been shown to be very effectively created by the dip-slip type of boundary motion, first reported in the work of Sengupta et al. [“Spatiotemporal growing wave-fronts in spatially stable boundary layers,” Phys. Rev. Lett. 96, 224504 (2006)], from both linear and nonlinear analyses of NSE. In this study, receptivity of the boundary layer to these two types of subduction motions is contrasted. This is performed for the first time using 3D DNS of NSE. It is shown that the dip-slip event displays stronger receptivity than the strike-slip event.
Formation of polar phase in Fe-doped ZrO2 epitaxial thin films
Authors: Choi S. , Shiraishi T. , Kiguchi T. , Shimizu T. , Funakubo H. , Konno T. J.
Published: December 2018

The existence of a polar phase in epitaxially grown Fe-doped ZrO2 thin films has been demonstrated. The films were prepared on yttria-stabilized zirconia substrates by ion-beam sputtering and subsequent annealing, where the composition was controlled by changing the FeO1.5-ZrO2 ratio of the sputtering target. The chemical states of elements in the 30 nm-thick xFeO1.5-(1−x)ZrO2 thin films (x = 0, 0.06, 0.10, and 0.14 nominal composition) have been measured by X-ray photoelectron spectroscopy, and the crystal structure has been examined by using X-ray diffraction and scanning transmission electron microscopy. These observations revealed that the undoped ZrO2 thin film (x = 0) is dominated by the monoclinic phase (space group: P21/c), while the films containing Fe exhibit multi-domain structures consisting of monoclinic and orthorhombic (Pbc21) phases, the latter being a polar phase, showing that the orthorhombic phase is stabilized by the addition of Fe. Concurrently, the polarization-electric field loops of the Fe-doped films exhibited hysteresis for the film with x = 0.06.
Squeezing-enhanced rotating-angle measurement beyond the quantum limit
Authors: Liu Kui , Cai Chunxiao , Li Juan , Ma Long , Sun Hengxin , Gao Jiangrui
Published: December 2018

Aided by quantum sources, quantum metrology helps to enhance measurement precision. Here, we introduce a method to enhance the measurement of a rotation angle. As a proof of principle, assisted by a quantum state called the squeezed orbital-angular-position (OAP) state and balance homodyne detection, we demonstrate in experiments 3 dB-enhanced measurements of a rotation-angle beyond the shot noise limit. A precision of up to 17.7 nrad/Hz is obtained. Furthermore, we discuss means to further improve the measurement with a high-order precision OAP squeezed state. The method holds promise for future practical applications, such as in high-sensitive Sagnac interferometry.
Evidence for pheomelanin sheet structure
Authors: Davy A. D. , Birch D. J. S.
Published: December 2018

Melanin remains one of the most enigmatic of pigments. It occurs in a variety of forms but is perhaps best known for its role in providing ultra-violet protection of skin as brown/black eumelanin and red/yellow pheomelanin. Despite decades of research, many questions remain about the structure, spectroscopy, and biology of both forms. For example, their unusually broad optical absorption spectra have attracted different explanations, no protomolecule has ever been identified, and pheomelanin has been implicated in melanoma, the most virulent form of skin cancer. Knowing more about the structure and spectroscopy of melanin is of paramount importance, not only in biology and medicine but also in the design of biomimetic functional devices. There is general consistency across a variety of techniques that eumelanin's building blocks arrange in π-stacked sheets analogous to graphite. By comparison, pheomelanin has been the neglected sibling and here we present evidence from fluorescence spectroscopy for pheomelanin also displaying sheet-like behavior. As pheomelanin is synthesized, the temporal response of the fluorescence intensity of the sheet-sensing probe thioflavin T (ThT) follows a similar sigmoidal increase as previously reported for eumelanin. Consistent with such intercalation, fluorescence decay measurements reveal evidence for close coupling between melanin and ThT excited states.
Surface modification of polyethylene terephthalate films by direct fluorination
Authors: Liu Yaqiang , Chen Qingqing , Du Xuelian , Li Liqiang , Li Peng
Published: December 2018

Polyethylene terephthalate (PET) films were surface fluorinated in a reaction kettle using a F2/N2 blend with 12.5% F2 by volume for the different time of 15, 30, 60, and 90 min at the same temperature of 30 °C. The chemical composition, surface morphology, wettability and thermal properties were characterized by attenuated total reflection fourier transform infrared spectroscopy (ATR-IR), field emission scanning electron microscopy (FE-SEM), contact angle and surface energy measurement, and thermogravimetry-differential thermal analysis (TG–DTA). It is found that surface chemical composition and structure was substantially altered due to fluorination and surface morphology evolved continuously with fluorination time. The results indicate that the surface hydrophilicity of the fluorinated PET films is much higher than that of the unfluorinated PET films and increases significantly with fluorination time, as the fluorination led to a large decrease in water contact and a dramatic increase in surface energy. An increase in the number of polar groups is regarded as the main reason for the increases of hydrophilicity with fluorination time. The surface fluorination causes a slight decrease in the thermal stability of PET films because of the introduction of chain scission.
Human RIPK1 deficiency causes combined immunodeficiency and inflammatory bowel diseases
Authors: Li Yue , Führer Marita , Bahrami Ehsan , Socha Piotr , Klaudel-Dreszler Maja , Bouzidi Amira , Liu Yanshan , Lehle Anna S. , Magg Thomas , Hollizeck Sebastian , Rohlfs Meino , Conca Raffaele , Field Michael , Warner Neil , Mordechai Slae , Shteyer Eyal , Turner Dan , Boukari Rachida , Belbouab Reda , Walz Christoph , Gaidt Moritz M. , Hornung Veit , Baumann Bernd , Pannicke Ulrich , Al Idrissi Eman , Ali Alghamdi Hamza , Sepulveda Fernando E. , Gil Marine , de Saint Basile Geneviève , Hönig Manfred , Koletzko Sibylle , Muise Aleixo M. , Snapper Scott B. , Schwarz Klaus , Klein Christoph , Kotlarz Daniel
Published: December 2018

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a critical regulator of cell death and inflammation, but its relevance for human disease pathogenesis remains elusive. Studies of monogenic disorders might provide critical insights into disease mechanisms and therapeutic targeting of RIPK1 for common diseases. Here, we report on eight patients from six unrelated pedigrees with biallelic loss-of-function mutations in
RIPK1
presenting with primary immunodeficiency and/or intestinal inflammation. Mutations in
RIPK1
were associated with reduced NF-κB activity, defective differentiation of T and B cells, increased inflammasome activity, and impaired response to TNFR1-mediated cell death in intestinal epithelial cells. The characterization of RIPK1-deficient patients highlights the essential role of RIPK1 in controlling human immune and intestinal homeostasis, and might have critical implications for therapies targeting RIPK1.
Arrestin-3 scaffolding of the JNK3 cascade suggests a mechanism for signal amplification
Authors: Perry Nicole A. , Kaoud Tamer S. , Ortega Oscar O. , Kaya Ali I. , Marcus David J. , Pleinis John M. , Berndt Sandra , Chen Qiuyan , Zhan Xuanzhi , Dalby Kevin N. , Lopez Carlos F. , Iverson T. M. , Gurevich Vsevolod V.
Published: December 2018

Significance

Scaffold proteins are key regulators of signal transduction that bind multiple proteins of a signaling pathway. This simple tethering model explains how the scaffold colocalizes the components for signal propagation, but it is unclear whether scaffolds ensure signal amplification. Here, we use arrestin-3 and the ASK1-MKK4/7-JNK3 kinase cascade as a model system to explore whether scaffolding amplifies signaling. Our studies suggest a model of scaffold-dependent signal amplification that may be conceptually applicable to other scaffold-dependent signaling pathways.
A promising fuel cell catalyst using non-precious metal oxide
Authors: Mohamed Hamdy F M , Abdel-Hady E E , Hmamm M F M , Ibrahim M , Ahmed H , Mondy M , Yehia H
Published: December 2018

Fuel cell has two essential problems, its cost and the durability, which hinder its commercialization. Platinum is the ideal catalyst that has high activity, stability and selectivity but has high cost. An attempt has been done to find a cheaper catalyst instead of platinum. Zinc oxide nanoparticles were synthesized via sol-gel method using zinc acetate and citric acid in basic media with different calcination temperatures (420, 520 and 620 °C). From X-ray diffraction (XRD) patterns, the calculated particles size is 7.7, 15.6 and 19.3 nm as the calcination temperature of 420, 520 and 620°C, respectively, indicating that the particles size increases with increasing the calcination temperature. Different concentrations (5 and 10 wt.%) of ZnO nanoparticles with 10 wt.% polyvinyl alcohol (PVA) were prepared and calcinated at 750 °C to get carbon/ZnO as a catalyst for fuel cell applications. A carbon core-shell surrounding by mono-disperse ZnO nanoparticles with large surface area that required for the new catalyst with believable morphology was shown by transmission electron microscope (TEM). Also, XRD presents high purity of the new composite with uniformly distinguishable peaks. Fourier transformation infrared (FTIR) spectroscopy shows the change in the carbon/ZnO nanoparticles spectra due to ZnO characteristic vibration band at 440-460 cm−1. Cyclic voltammetry (CV) exhibits a good promising catalytic activity and current density with oxidation behaviour is reported. Finally, ZnO used to enhance carbon electrochemically performance as a result of a novel non-precious catalyst.
Water quality assessment of Qarun Lake and heavy metals decontamination from its drains using nanocomposites
Authors: Goher M E , El-Rouby W M A , El-Dek S I , El-Sayed S M , Noaemy S G
Published: December 2018

Qarun Lake is one of the most important lakes in Egypt; it is the shrunken remnant of Moeris Lake. It is a closed ecosystem represented as a tank for discharged agricultural wastewater of El-Fayoum province. To assess the quality of the lake water for fishing and aquatic live utilization, Oregon water quality and metal pollution indices are computed. Based on the obtained results, water of the Qarun Lake is classified as very poor for the fishing utilization, where water quality index changed from 17.05 to 67.4 at the different stations. The metal indices; Pollution index (PI) and metal index (MI); showed that Qarun Lake water undergoes from a several grade of contamination for usage of aquatic life because of the enormous amount of wastes that discharging into the lake. Novel synthesized alginate nanocomposites (alginate, chitosan-alginate, and LDH-alginate and LDH-chitosan-alginate beads) were applied to remove heavy metal such as (Cd2+, Cu2+, Cr6+, Mn2+, Fe2+, Ni2+, Pb2+, and Zn2+) from different wastewater discharging into Qarun Lake. LDH-chitosan-alginate beads the exhibited the maximum removal efficiency that varied between 92.253 and 98.833 % for Cr6+ and Fe2+, respectively; in contrast, the alginate beads recorded the lowest one. The study indicated that the nanocomposite adsorbents, especially, LDH-chitosan-alginate beads are an effective substance for metal removal from different wastewater.
A Genetically Informed Study of Neighborhoods and Health: Results From the MIDUS Twin Sample
Authors: Robinette Jennifer W , Beam Christopher R
Published: December 2018

Objectives

To examine whether neighborhood income and neighborhood safety concerns influence multisystem physiological risk after adjusting for genetic and environmental selection effects that may have biased previous tests of this association.

Methods

We used structural equation modeling with a genetically informed sample of 686 male and female twin pairs in the Midlife in the United States Study II (2004).

Results

Controlling for additive genetic and shared environmental processes that may have biased neighborhood–health links in previous examinations, higher neighborhood safety concerns were associated with less physiological risk among women but not men.

Discussion

Our findings suggest a possible causal role of neighborhood features for a measure of physiological risk that is associated with the development of disease. Efforts to increase neighborhood safety, perhaps through increased street lighting or neighborhood watch programs, may improve community-level health.
Approximating Simple Locally Compact Groups by Their Dense Locally Compact Subgroups
Authors: Caprace Pierre-Emmanuel , Reid Colin , Wesolek Phillip
Published: December 2018

The class $\mathscr{S}$ of totally disconnected locally compact (tdlc) groups that are non-discrete, compactly generated, and topologically simple contains many compelling examples. In recent years, a general theory for these groups, which studies the interaction between the compact open subgroups and the global structure, has emerged. In this article, we study the non-discrete tdlc groups $H$ that admit a continuous embedding with dense image into some $G\in \mathscr{S}$; that is, we consider the dense locally compact subgroups of groups $G\in \mathscr{S}$. We identify a class $\mathscr{R}$ of almost simple groups that properly contains $\mathscr{S}$ and is moreover stable under passing to a non-discrete dense locally compact subgroup. We show that $\mathscr{R}$ enjoys many of the same properties previously obtained for $\mathscr{S}$ and establish various original results for $\mathscr{R}$ that are also new for the subclass $\mathscr{S}$, notably concerning the structure of the local Sylow subgroups and the full automorphism group.
Single-cell transcriptomes reveal molecular specializations of neuronal cell types in the developing cerebellum
Authors: Peng Jian , Sheng Ai-li , Xiao Qi , Shen Libing , Ju Xiang-Chun , Zhang Min , He Si-Ting , Wu Chao , Luo Zhen-Ge
Published: December 2018

The cerebellum is critical for controlling motor and non-motor functions via cerebellar circuit that is composed of defined cell types, which approximately account for more than half of neurons in mammals. The molecular mechanisms controlling developmental progression and maturation processes of various cerebellar cell types need systematic investigation. Here, we analyzed transcriptome profiles of 21119 single cells of the postnatal mouse cerebellum and identified eight main cell clusters. Functional annotation of differentially expressed genes revealed trajectory hierarchies of granule cells (GCs) at various states and implied roles of mitochondrion and ATPases in the maturation of Purkinje cells (PCs), the sole output cells of the cerebellar cortex. Furthermore, we analyzed gene expression patterns and co-expression networks of 28 ataxia risk genes, and found that most of them are related with biological process of mitochondrion and around half of them are enriched in PCs. Our results also suggested core transcription factors that are correlated with interneuron differentiation and characteristics for the expression of secretory proteins in glia cells, which may participate in neuronal modulation. Thus, this study presents a systematic landscape of cerebellar gene expression in defined cell types and a general gene expression framework for cerebellar development and dysfunction.
Managing the Behavior of Public Frontline Employees through Change-Oriented Training: Evidence from a Randomized Field Experiment
Authors: Jakobsen Morten , Jacobsen Christian Bøtcher , Serritzlew Søren
Published: December 2018

Most public frontline employees work out of sight of management. Direct management through authority and incentives is therefore often challenging. We argue that managers can rely on change-oriented training as an effective management tool that can affect employee behavior and work as an alternative or supplement to commands and incentives. First, we outline the concept of change-oriented training and explain how it can direct the behavior of public employees towards organizational goals and political priorities. Second, we test the effect of change-oriented training on employee behavior in a large-scale field experiment of teachers in Danish public schools. We show that training has a substantial effect on teachers’ behavior in the classroom and infer from this that training should be seen as a valuable management tool with the ability to influence the behavior of frontline employees.
Effects of environmental conditions and space on species turnover for three plant functional groups in Brazilian savannas
Authors: Menegat Hélio , Silvério Divino Vicente , Mews Henrique A , Colli Guarino R , Abadia Ana Clara , Maracahipes-Santos Leonardo , Gonçalves Lorrayne A , Martins Jhany , Lenza Eddie
Published: December 2018

Aims

Different plant functional groups display diverging responses to the same environmental gradients. Here, we assess the effects of environmental and spatial predictors on species turnover of three functional groups of Brazilian savannas (Cerrado) plants—trees, palms and lianas—across the transition zone between the Cerrado and Amazon biomes in central Brazil.

Methods

We used edaphic, climatic and plant composition data from nine one-hectare plots to assess the effects of the environment and space on species turnover using a Redundancy Analysis and Generalized Dissimilarity Modeling (GDM), associated with variance partitioning.

Important Findings

We recorded 167 tree species, 5 palms and 4 liana species. Environmental variation was most important in explaining species turnover, relative to geographic distance, but the best predictors differed between functional groups: geographic distance and silt for lianas; silt for palms; geographic distance, temperature and elevation for trees. Geographic distances alone exerted little influence over species turnover for the three functional groups. The pure environmental variation explained most of the liana and palm turnover, while tree turnover was largely explained by the shared spatial and environmental contribution. The effects of geographic distance upon species turnover leveled off at about 300 km for trees, and 200 km for lianas, whereas they were unimportant for palm species turnover. Our results indicate that environmental factors that determine floristic composition and species turnover differ substantially between plant functional groups in savannas. Therefore, we recommend that studies that aim to investigate the role of environmental conditions in determining plant species turnover should examine plant functional groups separately.
scCapsNet: a deep learning classifier with the capability of interpretable feature extraction, applicable for single cell RNA data analysis
Authors: Wang Lifei , Nie Rui , Xin Ruyue , Zhang Jiang , Cai Jun
Published: December 2018

Recently deep learning methods have been applied to process biological data and greatly pushed the development of the biological research forward. However, the interpretability of the deep learning methods still needs to improve. Here for the first time, we present scCapsNet, a totally interpretable deep learning model adapted from CapsNet. The scCapsNet model retains the capsule parts of CapsNet but replaces the part of convolutional neural networks with several parallel fully connected neural networks. We apply scCapsNet to scRNA-seq data. The results show that scCapsNet performs well as a classifier and also that the parallel fully connected neural networks function like feature extractors as we supposed. The scCapsNet model provides contribution of each extracted feature to the cell type recognition. Evidences show that some extracted features are nearly orthogonal to each other. After training, through analysis of the internal weights of each neural network connected inputs and primary capsule, and with the information about the contribution of each extracted feature to the cell type recognition, the scCapsNet model could relate gene sets from inputs to cell types. The specific gene set is responsible for the identification of its corresponding cell types but does not affect the recognition of other cell types by the model. Many well-studied cell type markers are in the gene set with corresponding cell type. The internal weights of neural network for those well-studied cell type markers are different for different primary capsules. The internal weights of neural network connected to a primary capsule could be viewed as an embedding for genes, convert genes to real value low dimensional vectors. Furthermore, we mix the RNA expression data of two cells with different cell types and then use the scCapsNet model trained with non-mixed data to predict the cell types in the mixed data. Our scCapsNet model could predict cell types in a cell mixture with high accuracy.
Assessing the bioenergy potential of grassland biomass from conservation areas in England
Authors: French Katherine E.
Published: December 2018

Bioenergy may be one of the ‘ecosystem services of the future’ for grasslands managed for conservation as the concept of bio-based economies is embraced worldwide. Although the idea of producing biogas and bioethanol from lignocellulosic material is not new, there are currently few regional-level comparisons of the bioenergy potential of high-diversity grasslands that would establish whether this could be a competitive bioenergy feedstock for farmers. Comparing the chemical composition and biogas yields of biomass samples from 13 grasslands in England and 73 other bioenergy feedstocks reveals that the lignin content of biomass from grasslands managed for conservation was up to 50% less than other bioenergy crops. Grasslands managed for conservation yielded up to 160% more biogas per ton dry matter than cereals or crop waste and only slightly less than Miscanthus. GIS modeling of the estimated biogas yields of grasslands managed for conservation and fields currently sown with Miscanthus show that grasslands are larger (20.57 ha) than Miscanthus fields (5.95 ha) and are projected to produce up to 117% more biogas per average field. Future incorporation of high-diversity grasslands into local and nation-wide energy plans may help reduce global fossil-fuel use in the 21st century.
BRG1 is a prognostic indicator and a potential therapeutic target for prostate cancer
Authors: Muthuswami Rohini , Bailey LeeAnn , Rakesh Radhakrishnan , Imbalzano Anthony , Nickerson Jeffrey , Hockensmith Joel W
Published: December 2018

BRG1 is one of two mutually exclusive ATPases that function as the catalytic subunit of human SWI/SNF chromatin remodeling enzymes. BRG1 has been identified as a tumor suppressor in some cancer types but has been shown to be expressed at elevated levels, relative to normal tissue, in other cancers. Using the TCGA (The Cancer Genome Atlas) prostate cancer database, we determined that BRG1 mRNA and protein expression is elevated in prostate tumors relative to normal prostate tissue. Only 3 of 491 (0.6%) sequenced tumors showed amplification of the locus or mutation in the protein coding sequence, arguing against the idea that elevated expression due to amplification or expression of a mutant BRG1 protein is associated with prostate cancer. Kaplan-Meier survival curves showed that BRG1 expression in prostate tumors inversely correlated with survival. However, BRG1 expression did not correlate with Gleason score/ISUP Grade Group, indicating it is an independent predictor of tumor progression/patient outcome. To experimentally assess BRG1 as a possible therapeutic target, we treated prostate cancer cells with a biologic inhibitor called ADAADi that targets the activity of the SNF2 family of ATPases in biochemical assays but showed specificity for BRG1 in prior tissue culture experiments. The inhibitor decreased prostate cancer cell proliferation and induced apoptosis. When directly injected into xenografts established by injection of prostate cancer cells in mouse flanks, the inhibitor decreased tumor growth and increased survival. These results indicate the efficacy of pursuing BRG1 as both an indicator of patient outcome and as a therapeutic target.
LEMMI: A continuous benchmarking platform for metagenomics classifiers
Authors: Seppey Mathieu , Manni Mose , Zdobnov Evgeny M
Published: December 2018

Studies of microbiomes are booming, as well as the diversity of computational tools to make sense out of the sequencing data and the volumes of accumulated microbial genotypes. LEMMI (https://lemmi.ezlab.org) is a novel concept of a benchmarking platform of computational tools for metagenome composition assessments that introduces: a continuous integration of tools, their multi-objective ranking, and an effective distribution through software containers. Here, we detail the workflow and discuss the evaluation of some recently released methods. We see this platform eventually as a community-driven effort: where method developers can showcase novel approaches and get unbiased benchmarks for publications, while users can make informed choices and obtain standardized and easy-to-use tools.
Premeiotic and meiotic failures lead to hybrid male sterility in theAnopheles gambiaecomplex
Authors: Liang Jiangtao , Sharakhov Igor V.
Published: December 2018

Hybrid male sterility contributes to speciation by restricting gene flow between related taxa. Detailed cytological characterizations of reproductive organs in hybrid males is important for identifying phenotypes that can help guide searches of speciation genes. To investigate possible cellular causes of hybrid male sterility, we performed crosses between closely related species of theAnopheles gambiaecomplex:An. meruswithAn. gambiaeorAn. coluzzii. We demonstrate that hybrid male sterility in African malaria mosquitoes involves two defects in the reciprocal crosses: a premeiotic arrest of germline stem cells in degenerate testes and a failure of the reductional meiotic division of primary spermatocytes in normal-like testes. The premeiotic arrest in degenerate testes of hybrids is accompanied by a strong suppression of meiotic and postmeiotic genes. Unlike pure species, sex chromosomes in normal-like testes of F1 hybrids are largely unpaired during meiotic prophase I and all chromosomes show various degrees of insufficient condensation. Instead of entering reductional division in meiosis I, primary spermatocytes prematurely undergo an equational mitotic division producing nonmotile diploid sperm. Thus, our study identified cytogenetic errors in interspecies hybrids that arise during the early stages of postzygotic isolation.
Genetically regulated gene expression underlies lipid traits in Hispanic cohorts
Authors: Andaleon Angela , Mogil Lauren S. , Wheeler Heather E.
Published: December 2018

Plasma lipid levels are risk factors for cardiovascular disease, a leading cause of death worldwide. While many studies have been conducted in genetic variation underlying lipid levels, they mainly comprise individuals of European ancestry and thus their transferability to non-European populations is unclear. We performed genome-wide (GWAS) and imputed transcriptome-wide association studies of four lipid traits in the Hispanic Community Health Study/Study of Latinos cohort (HCHS/SoL, n = 11,103), replicated top hits in the Multi-Ethnic Study of Atherosclerosis (MESA, n = 3,855), and compared the results to the larger, predominantly European ancestry meta-analysis by the Global Lipids Genetics Consortium (GLGC, n = 196,475). In our GWAS, we found significant SNP associations in regions within or near known lipid genes, but in our admixture mapping analysis, we did not find significant associations between local ancestry and lipid phenotypes. In the imputed transcriptome-wide association study in multiple tissues and in different ethnicities, we found 59 significant gene-tissue-phenotype associations (P < 3.61×10−8) with 14 unique significant genes, many of which occurred across multiple phenotypes, tissues, and ethnicities and replicated in MESA (45/59) and in GLGC (44/59). These include well-studied lipid genes such as SORT1, CETP, and PSRC1, as well as genes that have been implicated in cardiovascular phenotypes, such as CCL22 and ICAM1. The majority (40/59) of significant associations colocalized with expression quantitative trait loci (eQTLs), indicating a possible mechanism of gene regulation in lipid level variation. To fully characterize the genetic architecture of lipid traits in diverse populations, larger studies in non-European ancestry populations are needed.
RLIM enhances BMP signalling mediated fetal lung development in mice
Authors: Kammoun Molka , Maas Elke , Criem Nathan , Gribnau Joost , Zwijsen An , Vermeesch Joris Robert
Published: December 2018

RLIM, also called RNF12, is an X-linked E3 ubiquitin ligase. It is a pleotropic protein acting as a negative regulator of LIM-homeodomain transcription factors and of SMAD7, an antagonist of the BMP and TGFβ pathways. Mutations in RLIM are associated with variable congenital malformations in human. The molecular mechanism causing these malformations is still poorly understood.
In this study, we used a conventional knockout (KO) mouse model to phenotypically characterize male mutants and to investigate the effect of Rlim mutation on BMP pathway signalling. Only 50% of KO male neonates survive and are significantly smaller. We show that Rlim deletion alters lung branching and maturation resulting in severe respiratory distress and neonatal death. Except for a single case of cardiac interventricular septal defect, no other malformations that mimic the human condition were observed. Western blot analysis shows that RLIM deficiency is associated with an increase of its target SMAD7 levels and a loss of SMAD1/5/9 activation. Interestingly, SMAD5 levels were diminished, suggesting another regulatory loop between RLIM and the BMP pathway.
In conclusion, RLIM is important for lung development in mice and exerts this function in part through intracellular propagation of BMP signalling.
Two single-enantiomer amidophosphoesters: a database study on the chirality of (O)2P(O)(N)-based structures
Authors: Sabbaghi Fahimeh , Pourayoubi Mehrdad , Nečas Marek , Damodaran Krishnan
Published: December 2018

The crystal structures of two single-enantiomer amidophosphoesters with an (O)2P(O)(N) skeleton, i.e. diphenyl [(R)-(+)-α-methylbenzylamido]phosphate, (I), and diphenyl [(S)-(−)-α-methylbenzylamido]phosphate, (II), both C20H20NO3P, are reported. In both structures, chiral one-dimensional hydrogen-bonded architectures, along [010], are mediated by N—H...OP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P21. As a result of synergistic co-operation from C—H...O interactions, a two-dimensional superstructure is built including a noncentrosymmetric R
4
4(22) hydrogen-bonded motif. A Cambridge Structural Database survey was performed on (O)2P(O)(N)-based structures in order to review the frequency of space groups observed in this family of compounds; the hydrogen-bond motifs in structures with chiral space groups and the types of groups inducing chirality are discussed. The 2,3
JX

–P (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C6H5O groups are different, which is reflected in the different chemical shifts and some coupling constants.
Process owners in business process management: a systematic literature review
Authors: Danilova Kjersti Berg
Published: December 2018

Purpose

The purpose of this paper is to determine the state-of-the-art in research on process owners, a key role within business process management and process governance, and thus to increase our understanding of the role of process owners.

Design/methodology/approach

The author conducts a systematic literature review of research shedding light on the role of process owners. The review includes 100 academic papers and 10 books on BPM.

Findings

Findings from the review demonstrate the significance of appointing process owners and showcase process owners’ role and responsibilities, as well as obstacles to and enablers of effective process ownership.

Originality/value

Based on the findings from the review, the author proposes a comprehensive framework on process ownership. The review provides a knowledge base for future research to build upon and can serve as a guide for practitioners. The review also identifies several research gaps and opportunities for future research.