bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards an Unstaggered Finite‐Volume Dynamical Core With a Fast Riemann Solver: 1‐D Linearized Analysis of Dissipation, Dispersion, and Noise Control
Authors: Chen Xi , Lin Shiann‐Jiann , Harris Lucas M. 
Published: September 2018

AbstractMany computational fluid dynamics codes use Riemann solvers on an unstaggered grid for finite volume methods, but this approach is computationally expensive compared to existing atmospheric dynamical cores equipped with hyper‐diffusion or other similar relatively simple diffusion forms. We present a simplified Low Mach number Approximate Riemann Solver (LMARS), made computationally efficient through assumptions appropriate for atmospheric flows: low Mach number, weak discontinuities, and locally uniform sound speed. This work will examine the dissipative and dispersive properties of LMARS using Von Neumann linearized analysis to the one‐dimensional linearized shallow water equations. We extend these analyses to higher‐order methods by numerically solving the Fourier‐transformed equations. It is found that the pros and cons due to grid staggering choices diminish with high‐order schemes. The linearized analysis is limited to modal, smooth solutions using simple numerical schemes, and cannot analyze solutions with discontinuities. To address this problem, this work presents a new idealized test of a discontinuous wave packet, a single Fourier mode modulated by a discontinuous square wave. The experiments include studies of well‐resolved and (near) grid‐scale wave profiles, as well as the representation of discontinuous features and the results are validated against the Von Neumann analysis. We find the higher‐order LMARS produces much less numerical noise than do inviscid unstaggered and especially staggered schemes while retaining accuracy for better‐resolved modes.
A 1.9‐Ga Mélange Along the Northern Margin of the North China Craton: Implications for the Assembly of Columbia Supercontinent
Authors: Wu Chen , Zhou Zhiguang , Zuza Andrew V. , Wang Guosheng , Liu Changfeng , Jiang Tian 
Published: September 2018

AbstractThe involvement and location of the Neoarchean‐Paleoproterozoic North China craton in the supercontinent Columbia remains enigmatic, and the tectonic history along its margins impacts our understanding of connections between North China and other continents. Here we present structural observations from a Paleoproterozoic mélange that is located along its northern margin and that we refer to as the Bayan Obo mélange. It is composed of a structurally complex tectonic mixture of metapelites and metasedimentary rocks mixed with exotic blocks of ultramafic‐mafic rocks, metabasalts, metacarbonate and alkaline rocks, and tonalite‐trondhjemite gneisses. New zircon geochronology of the various constituent blocks suggest that it formed, and was subsequently deformed, at ca. 1.9 Ga. The oldest intramélange blocks are 2.45‐ to 2.54‐Ga tonalite‐trondhjemite‐granodiorite rocks and granitoids that signify the stabilization of the northern North China in the Neoarchean‐Paleoproterozoic. A ca. 2.45‐Ga plagiogranite block probably originated by partial melting of the older tonalite‐trondhjemite‐granodiorite rocks. We suggest that this mélange formed in a sedimentary setting near the subduction trench, on the basis of mixing of upper and lower plate volcanic rocks and textural relationships. The Bayan Obo mélange thus represents one of the oldest documented sedimentary mélanges on Earth, yet its fundamental characteristics strongly resemble Phanerozoic subduction complexes. Based on similar ages and styles of deformation, this zone may represent the ca. 1.9‐Ga collisional zone between North China and the southwestern margin of the Siberia craton. In this context, the North China craton became an integral component of the supercontinent Columbia starting at ca. 1.9 Ga.
METRNL attenuates lipid-induced inflammation and insulin resistance via AMPK or PPARδ-dependent pathways in skeletal muscle of mice
Authors: Jung Tae Woo , Lee Sung Hoon , Kim Hyoung-Chun , Bang Joon Seok , Abd El-Aty A. M. , Hacımüftüoğlu Ahmet , Shin Yong Kyoo , Jeong Ji Hoon 
Published: September 2018

AbstractPhysical activity has many beneficial effects on metabolic disorders, such as obesity, insulin resistance, and diabetes. Meteorin-like protein (METRNL), a novel secreted protein homologous to the neurotrophin Metrn, is induced after exercise in the skeletal muscle. Herein, we investigated the effects of METRNL on lipid-mediated inflammation and insulin resistance in skeletal muscle via AMP-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor δ (PPARδ). Treatment with METRNL suppressed inflammatory markers, such as nuclear factor κB (NFκB) nuclear translocation, inhibitory κBα (IκBα) phosphorylation, interleukin-6 (IL-6) expression, and pro-inflammatory cytokines (such as TNFα and MCP-1). METRNL treatment also attenuated the impaired insulin response both in palmitate-treated differentiated C2C12 cells and the skeletal muscle of high-fat diet (HFD)-fed mice. Furthermore, METRNL administration rescued glucose intolerance and reduced HFD-induced body weight gain in mice; however, METRNL did not affect calorie intake. METRNL treatment increased AMPK phosphorylation and PPARδ expression both in differentiated C2C12 cells and mouse skeletal muscle. siRNA-mediated suppression of AMPK and PPARδ abrogated the suppressive effects of METRNL on palmitate-induced inflammation and insulin resistance. Moreover, METRNL augmented the mRNA expression of fatty acid oxidation-associated genes, such as carnitine palmitoyltransferase 1 (CPT1), acyl-CoA oxidase (ACO), and fatty acid binding protein 3 (FABP3). siRNAs for AMPK and PPARδ reversed these changes. In the current study, we report for the first time that METRNL alleviates inflammation and insulin resistance and induces fatty acid oxidation through AMPK or PPARδ-dependent signaling in skeletal muscle.
Exceptional thermoelectric properties of flexible organic−inorganic hybrids with monodispersed and periodic nanophase
Authors: Wang Liming , Zhang Zimeng , Liu Yuchen , Wang Biran , Fang Lei , Qiu Jingjing , Zhang Kun , Wang Shiren 
Published: September 2018

AbstractFlexible organic−inorganic hybrids are promising thermoelectric materials to recycle waste heat in versatile formats. However, current organic/inorganic hybrids suffer from inferior thermoelectric properties due to aggregate nanostructures. Here we demonstrate flexible organic−inorganic hybrids where size-tunable Bi2Te3 nanoparticles are discontinuously monodispersed in the continuous conductive polymer phase, completely distinct from traditional bi-continuous hybrids. Periodic nanofillers significantly scatter phonons while continuous conducting polymer phase provides favored electronic transport, resulting in ultrahigh power factor of ~1350 μW m−1 K−2 and ultralow in-plane thermal conductivity of ~0.7 W m−1 K−1. Consequently, figure-of-merit (ZT) of 0.58 is obtained at room temperature, outperforming all reported organic materials and organic−inorganic hybrids. Thermoelectric properties of as-fabricated hybrids show negligible change for bending 100 cycles, indicating superior mechanical flexibility. These findings provide significant scientific foundation for shaping flexible thermoelectric functionality via synergistic integration of organic and inorganic components.
Zigzag carbon as efficient and stable oxygen reduction electrocatalyst for proton exchange membrane fuel cells
Authors: Xue Longfei , Li Yongcheng , Liu Xiaofang , Liu Qingtao , Shang Jiaxiang , Duan Huiping , Dai Liming , Shui Jianglan 
Published: September 2018

AbstractNon-precious-metal or metal-free catalysts with stability are desirable but challenging for proton exchange membrane fuel cells. Here we partially unzip a multiwall carbon nanotube to synthesize zigzag-edged graphene nanoribbons with a carbon nanotube backbone for electrocatalysis of oxygen reduction in proton exchange membrane fuel cells. Zigzag carbon exhibits a peak areal power density of 0.161 W cm−2 and a peak mass power density of 520 W g−1, superior to most non-precious-metal electrocatalysts. Notably, the stability of zigzag carbon is improved in comparison with a representative iron-nitrogen-carbon catalyst in a fuel cell with hydrogen/oxygen gases at 0.5 V. Density functional theory calculation coupled with experimentation reveal that a zigzag carbon atom is the most active site for oxygen reduction among several types of carbon defects on graphene nanoribbons in acid electrolyte. This work demonstrates that zigzag carbon is a promising electrocatalyst for low-cost and durable proton exchange membrane fuel cells.
The human gut pan-microbiome presents a compositional core formed by discrete phylogenetic units
Authors: Aguirre de Cárcer Daniel 
Published: September 2018

AbstractThe complex community of microbes living in the human gut plays an important role in host wellbeing. However, defining a ‘healthy’ gut microbiome in terms of composition has remained an elusive task, despite its anticipated medical and scientific importance. In this regard, a central question has been if there is a ‘core’ microbiome consisting of bacterial groups common to all healthy humans. Recent studies have been able to define a compositional core in human gut microbiome datasets in terms of taxonomic assignments. However, the description of the core microbiome in terms of taxonomic assignments may not be adequate when considering subsequent analyses and applications. Through the implementation of a dynamic clustering approach in the meta-analyisis of comprehensive 16S rRNA marker gene datasets, this study found that the human gut pan-microbiome presents a preeminent compositional core comprised of discrete units of varying phylogenetic depth present in all individuals studied. Since both microbial traits and ecological coherence show signs of phylogenetic conservation, this outcome provides a new conceptual framework in the study of the ecosystem, as well as important practical considerations which should be taken into account in future research.
Better than DEET Repellent Compounds Derived from Coconut Oil
Authors: Zhu Junwei J. , Cermak Steven C. , Kenar James A. , Brewer Gary , Haynes Kenneth F. , Boxler Dave , Baker Paul D. , Wang Desen , Wang Changlu , Li Andrew Y. , Xue Rui-de , Shen Yuan , Wang Fei , Agramonte Natasha M. , Bernier Ulrich R. , de Oliveira Filho Jaires G. , Borges Ligia M. F. , Friesen Kristina , Taylor David B. 
Published: September 2018

AbstractHematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effective and long-lasting repellent currently available commercially, has long been considered the gold standard in insect repellents, but with reported human health issues, particularly for infants and pregnant women. In the present study, we report fatty acids derived from coconut oil which are novel, inexpensive and highly efficacious repellant compounds. These coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes. The medium-chain length fatty acids from C8:0 to C12:0 were found to exhibit the predominant repellent activity. In laboratory bioassays, these fatty acids repelled biting flies and bed bugs for two weeks after application, and ticks for one week. Repellency was stronger and with longer residual activity than that of DEET. In addition, repellency was also found against mosquitoes. An aqueous starch-based formulation containing natural coconut fatty acids was also prepared and shown to protect pastured cattle from biting flies up to 96-hours in the hot summer, which, to our knowledge, is the longest protection provided by a natural repellent product studied to date.
Multi-unit relations among neural, self-report, and behavioral correlates of emotion regulation in comorbid depression and obesity
Authors: Pines Adam R. , Sacchet Matthew D. , Kullar Monica , Ma Jun , Williams Leanne M. 
Published: September 2018

AbstractDepression is a leading cause of disability and is commonly comorbid with obesity. Emotion regulation is impaired in both depression and obesity. In this study, we aimed to explicate multi-unit relations among brain connectivity, behavior, and self-reported trait measures related to emotion regulation in a comorbid depressed and obese sample (N = 77). Brain connectivity was quantified as fractional anisotropy (FA) of the uncinate fasciculi, a white matter tract implicated in emotion regulation and in depression. Use of emotion regulation strategies was assessed using the Emotion Regulation Questionnaire (ERQ). We additionally measured reaction times to identifying negative emotions, a behavioral index of depression-related emotion processing biases. We found that greater right uncinate fasciculus FA was related to greater usage of suppression (r = 0.27, p = 0.022), and to faster reaction times to identifying negative emotions, particularly sadness (r = −0.30, p = 0.010) and fear (r = −0.35, p = 0.003). These findings suggest that FA of the right uncinate fasciculus corresponds to maladaptive emotion regulation strategies and emotion processing biases that are relevant to co-occurring depression and obesity. Interventions that consider these multi-unit associations may prove to be useful for subtyping and improving clinical outcomes for comorbid depression and obesity.
Effects of ocean warming and coral bleaching on aerosol emissions in the Great Barrier Reef, Australia
Authors: Jackson Rebecca , Gabric Albert , Cropp Roger 
Published: September 2018

AbstractIt is proposed that emissions of volatile sulfur compounds by coral reefs contribute to the formation of a biologically-derived feedback on sea surface temperature (SST) through the formation of marine biogenic aerosol (MBA). The direction and strength of this feedback remains uncertain and constitutes a fundamental constraint on predicting the ability of corals to cope with future ocean warming. We investigate the effects of elevated SST and irradiance on satellite-derived fine-mode aerosol optical depth (AOD) throughout the Great Barrier Reef, Australia (GBR) over an 18-year time period. AOD is positively correlated with SST and irradiance and increases two-fold during spring and summer with high frequency variability. As the influence of non-biogenic and distant aerosol sources are found to be negligible, the results support recent findings that the 2,300 km stretch of coral reefs can be a substantial source of biogenic aerosol and thus, influence local ocean albedo. Importantly however, a tipping point in the coral stress response is identified, whereby thermal stress reaches a point that exceeds the capacity of corals to influence local atmospheric properties. Beyond this point, corals may become more susceptible to permanent damage with increasing stress, with potential implications for mass coral bleaching events.
The ALMA Frontier Fields Survey
Authors: Muñoz Arancibia A. M. , González-López J. , Ibar E. , Bauer F. E. , Carrasco M. , Laporte N. , Anguita T. , Aravena M. , Barrientos F. , Bouwens R. J. , Demarco R. , Infante L. , Kneissl R. , Nagar N. , Padilla N. , Romero-Cañizales C. , Troncoso P. , Zitrin A. 
Published: September 2018

Context. Characterizing the number counts of faint (i.e., sub-mJy and especially sub-100 μJy), dusty star-forming galaxies is currently a challenge even for deep, high-resolution observations in the FIR-to-mm regime. They are predicted to account for approximately half of the total extragalactic background light at those wavelengths. Searching for dusty star-forming galaxies behind massive galaxy clusters benefits from strong lensing, enhancing their measured emission while increasing spatial resolution. Derived number counts depend, however, on mass reconstruction models that properly constrain these clusters.
Aims. We aim to estimate the 1.1 mm number counts along the line of sight of three galaxy clusters, Abell 2744, MACS J0416.1–2403, and MACS J1149.5+2223, which are part of the ALMA Frontier Fields Survey. We have performed detailed simulations to correct these counts for lensing effects, probing down to the sub-mJy flux density level.
Methods. We created a source catalog based on ALMA 1.1 mm continuum detections. We used several publicly available lensing models for the galaxy clusters to derive the intrinsic flux densities of these sources. We performed Monte Carlo simulations of the number counts for a detailed treatment of the uncertainties in the magnifications and adopted source redshifts.
Results. We estimate lensing-corrected number counts at 1.1 mm using source detections down to S/N = 4.5. In each cluster field, we find an overall agreement among the number counts derived for the different lens models, despite their systematic variations regarding source magnifications and effective areas. Combining all cluster fields, our number counts span ∼2.5 dex in demagnified flux density, from several mJy down to tens of μJy. Both our differential and cumulative number counts are consistent with recent estimates from deep ALMA observations at a 3σ level. Below ≈0.1 mJy, however, our cumulative counts are lower by ≈1 dex, suggesting a flattening in the number counts.
Conclusions. We derive 1.1 mm number counts around three well-studied galaxy clusters following a statistical approach. In our deepest ALMA mosaic, we estimate number counts for intrinsic flux densities ≈4 times fainter than the rms level. This highlights the potential of probing the sub-10 μJy population in larger samples of galaxy cluster fields with deeper ALMA observations.
The spiral potential of the Milky Way
Authors: Grosbøl P. , Carraro G. 
Published: September 2018

Context. The location of young sources in the Galaxy suggests a four-armed spiral structure, whereas tangential points of spiral arms observed in the integrated light at infrared and radio wavelengths indicate that only two arms are massive.
Aims. Variable extinction in the Galactic plane and high light-to-mass ratios of young sources make it difficult to judge the total mass associated with the arms outlined by such tracers. The current objective is to estimate the mass associated with the Sagittarius arm by means of the kinematics of the stars across it.
Methods. Spectra of 1726 candidate B- and A-type stars within 3◦ of the Galactic center (GC) were obtained with the FLAMES instrument at the VLT with a resolution of ≈6000 in the spectral range of 396–457 nm. Radial velocities were derived by least-squares fits of the spectra to synthetic ones. The final sample was limited to 1507 stars with either Gaia DR2 parallaxes or main-sequence B-type stars having reliable spectroscopic distances.
Results. The solar peculiar motion in the direction of the GC relative to the local standard of rest (LSR) was estimated to U⊙ = 10.7 ± 1.3kms−1. The variation in the median radial velocity relative to the LSR as a function of distance from the sun shows a gradual increase from slightly negative values near the sun to almost 5 km s−1 at a distance of around 4 kpc. A sinusoidal function with an amplitude of 3.4 ± 1.3kms−1 and a maximum at 4.0 ± 0.6 kpc inside the sun is the best fit to the data. A positive median radial velocity relative to the LSR around 1.8 kpc, the expected distance to the Sagittarius arm, can be excluded at a 99% level of confidence. A marginal peak detected at this distance may be associated with stellar streams in the star-forming regions, but it is too narrow to be associated with a major arm feature.
Conclusions. A comparison with test-particle simulations in a fixed galactic potential with an imposed spiral pattern shows the best agreement with a two-armed spiral potential having the Scutum–Crux arm as the next major inner arm. A relative radial forcing dFr ≈ 1.5% and a pattern speed in the range of 20–30 km s−1 kpc−1 yield the best fit. The lack of a positive velocity perturbation in the region around the Sagittarius arm excludes it from being a major arm. Thus, the main spiral potential of the Galaxy is two-armed, while the Sagittarius arm is an inter-arm feature with only a small mass perturbation associated with it.
Einige Gedanken zur Sentenz: „… aber wir wissen nicht, warum Homöopathie wirkt“
Authors: Würger Wolfgang 
Published: September 2018

ZusammenfassungDas Ziel eines wissenschaftlichen Paradigmas in der Situation der Paradigmenkonkurrenz besteht nicht zuletzt darin, das Selbstvertrauen seiner Gegner systematisch zu schwächen. So verfährt auch die Schulmedizin gegenüber der Homöopathie, indem sie ihr unablässig Defizite an Wissenschaftlichkeit zuzuschreiben versucht. Fatal ist, dass diese Vorwürfe von manchen Homöopathen – entgegen aller wissenschaftstheoretischen Evidenz – noch immer geglaubt werden. Diesen Zustand gilt es wissenschaftstheoretisch zu kritisieren und durch praktisches Handeln aufzulösen.
Wissenschaftliche Homöopathie – eine persönliche Standortbestimmung
Authors: Ivanovas Georg 
Published: September 2018

ZusammenfassungWissenschaftliches Denken ist durch neues Wissen einem ständigen Wandlungsprozess unterworfen. Diese wissenschaftliche Weiterentwicklung hat in der Homöopathie seit Hahnemann nicht angemessen stattgefunden. Dies führte zu einer zunehmenden Inkongruenz von Modell und beobachteter Wirklichkeit. Die Konsequenzen für die therapeutische Praxis sind dabei erheblich. Dies wird anhand des Miasmabegriffs und der Behandlung des Asthmas beispielhaft dargestellt.
Samuel Hahnemann und die Honorarfrage
Authors: Jütte Robert 
Published: September 2018

ZusammenfassungZweifellos machte zur Zeit Hahnemanns das Arzthonorar den größten Teil des ärztlichen Einkommens aus. Weil er von diesen Einkünften in seiner Privatpraxis abhängig war, musste sich ein Arzt darum sorgen, vom Patienten Geld zu bekommen, was damals sehr häufig nicht der Fall war. Nicht nur in England, auch auf dem Kontinent waren Patienten bekannt dafür, zu spät oder gar nicht die Arztrechnung zu begleichen. So wurden Ärzte oft zu Gläubigern. Manchmal löste man das Problem durch Ratenzahlungen. Über die Rechnung vor Gericht zu streiten, erwies sich meist als zu kostspielig. Vor diesem Hintergrund wird verständlich, dass Hahnemann als Erfinder eine neuen Heilkunde, die bereits damals sehr umstritten war, seinen Anhängern den Rat gab, dass Vorauszahlung oder Begleichung der Honorarforderung an Ort und Stelle die Voraussetzung für eine erfolgreiche homöopathische Praxis war. Da Hahnemann Angriffen vonseiten der Allopathen ausgesetzt war, wusste er auch die laxe Zahlungsmoral seiner Patienten richtig einzuschätzen und entsprechende Gegenmaßnahmen zu treffen.
Das Selbstverständnis des homöopathischen Arztes oder Wege der Reifung und Befreiung
Authors: Trebin Ernst 
Published: September 2018

ZusammenfassungDie Behandlung chronischer Krankheiten erfordert einen beachtlichen Zeitraum und ist als dynamischer Prozess zu sehen, der ein zunehmend vertieftes Verstehen des Patienten erlaubt und einen kontinuierlichen Abbau seiner ererbten Krankheitsveranlagungen und seiner belastenden biografischen Prägungen zum Ziel hat. Die Funktion des homöopathischen Behandlers besteht in einer stetigen Begleitung auf dem Weg der Reifung und Befreiung.