bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of the properties of nano-modified concretes
Authors: Sharanova A V , Dmitrieva M A , Zakharov A A
Published: November 2019

Nanomodified concrete is obtained from multicomponent dry building mixes based on Portland cement containing nanoscale filler particles. This paper examines the cement-sand mixture activated in a high-energy mill as a nanomodifier. The result is the gain in strength of concrete in the initial hardening time. The influence of fractional characteristics of sand on the activation process is analyzed. Three sand samples of different deposits of the Kaliningrad region characterized by different size and content of dust and clay particles were studied. The results of tests of samples of fine-grained concrete with activated and non-activated components for the initial compressive strength at the age of 0-90 minutes after the preparation of the mixture are presented. It is noted that the mechanical activation of cement-sand mixture is most effective when there are large fractions in the activated sand.
Weak adhesion and delamination of hydrogenated diamond like carbon coating on a rough surface of tappet valve substrate
Authors: Kolawole F O , Varela L B , Kolawole S K , Ramirez M A , Tschiptschin A P
Published: November 2019

DLC(a-C:H) film are known for their excellent tribological properties however, possess poor adhesion on metallic substrate causing film delamination. Introduction of adhesive silicon interlayer has showed improvement in the adhesion of DLC-H on metallic substrate. In the present study DLC-H was deposited on tappet valve and silicon wafer using PECVD. The as-deposited DLC-H was characterized using XRD, EDS and Raman spectroscopy. SEM was also used to measure the thickness of the DLC-H coating and the average surface roughness (Ra) was measured using 3D Profilometry. Scratch test was used to determine the COF, adhesion and hardness of the DLC-H coating. The DLC-H coating on tappet valve had weak adhesion compared with DLC-H coating deposited on silicon substrate, which had good adhesion. The result of the Raman spectroscopy revealed a sp3 fraction of 0.43 for the DLC-H deposited on silicon substrate. The thickness of the as-deposited DLC-H film was 1.78 µm, which was measured using SEM to view the cross-section of the as-deposited DLC-H coating on the silicon substrate. The surface roughness of the as-deposited DLC-H coating on silicon substrate was 26.59 nm. Silicon substrate coated with DLC-H had the lowest COF, ranging from 0.06 to 0.09.
Fast Switching Valve Utilization to Control Pneumatic Cylinder Speed
Authors: Adel Elkashef M. , Aly Mohamed , Mahmoud Osama E. , Hossamel-din Yehia H.
Published: November 2019

The position and speed of the piston of pneumatic cylinder are very important parameters in evaluating the pneumatic system performance. Utilization of Pulse Width Modulation (PWM) technique to control the Fast Switching Valve (FSV) usually causes fluctuation in the piston motion and accordingly, the system performance deteriorates. The objective of this work is to introduce a novel PWM control technique considering the suitable duty cycles according to the switching frequency in order to improve the FSV characteristics and reduce piston speed fluctuation. A test rig for a simple pneumatic circuit with an FSV as a control element has been designed and realized. The displacement of the piston is measured using a Linear Wire Potentiometer Transducer (LWPT), while its derivative is used to estimate the speed considering a low pass filter to reduce the effect of piston position signal noise. A nonlinear mathematical model is introduced and experimentally validated. The results of both computer simulation and experimental measurements show that the integration between fast switching valve and PWM control signal leads to a quasi-linear relationship between duty cycle and piston speed. Moreover; results proved the successful control of piston speed based on the correct duty cycle and valve switching frequency.
The performance of structured and unstructured grids on wind simulations around a high-rise building
Authors: Hågbo T-O , Giljarhus K E T , Qu S , Hjertager B H
Published: November 2019

In this study, computational fluid dynamics has been applied to analyze the performance of both structured and unstructured meshes when used in steady-state simulations of wind in an urban area. This case specifically examines the wind environment around a single high-rise building with the geometry of 1: 1: 2 (length, width, height) within the atmospheric boundary layer.The Reynolds-averaged Navier-Stokes simulations were conducted using OpenFOAM, with grids generated withblockMesh, snappyHexMesh,andPointwise.A set of coarse meshes and a set of fine meshes were used for comparison.Minor differences in the flow pattern were observed depending on the mesh type used, including the reattachment lengths, the drag coefficients, the velocity profiles, and the positioning of the vortex leeward of the high-rise building. However, the main flow features were the same, indicating that for simulations where overall flow features are of importance there is high flexibility in choice of meshing technique.
Analysis of the alkali-activated fly ashes from electrostatic precipitators by impedance measurements
Authors: Walter J , Mierzwiński D , Kosiba K
Published: November 2019

Curing the fly ash materials with addition of sand activated by 8 M sodium hydroxide (NaOH) was analysed by impedance spectroscopy. The measurements were carried out for 6 hours from the moment the samples were put into the oven at 75 °C. It was found characteristic similar shape of impedance curves recorded versus time of solidification process. Starting from the curve obtained after 52 min to longer times impedance curve crossed at about 30 Hz. The first lower than 30 Hz frequencies range showed continues decreasing of impedance values with increasing the time. Changes in impedance curve versus time looks different for second frequencies higher than 30 Hz. Temperature of the material increases slightly over temperature of the oven as a result of exothermic reactions which can be seen at impedance vs. time curve as a bulge. The starting of these reactions can be seen more precisely in the second range of the frequency as a continuous increase of impedance value preceded by its initial fast decline. The main purpose of the article is the possibility of using the described method, it can be particularly useful for assessing the starting point of an exothermic reaction and its progress in the case of different masses of heated material.
Development of a stabilized natural fiber-reinforced earth composite for construction applications using 3D printing
Authors: Silva G , Quispe L , Kim S , Nakamatsu J , Aguilar R
Published: November 2019

The application of additive manufacturing technologies to the construction industry has a wide range of advantages from the economic, social and design flexibility point of view. However, most of up to date research studies have been performed using ordinary Portland cement (OPC)-based mortars and concretes. Therefore, the objective of this article is to explore the development of an eco-friendly earth composite reinforced with natural sisal fibers and chemically stabilized with a hydraulic binder. Analysis of the workability by shear vane tests was performed on fresh earth samples to find the optimum water content in sisal fiber-reinforced earth stabilized with OPC. Afterward, the effect of the addition of OPC on the hardening process was evaluated through shear vane and Vicat needle tests from 0 to 180 min after mixing. The results indicate that water content, fiber addition and OPC replacement have a strong influence on the shear yield strength. Furthermore, the presence of chemical stabilizers as OPC accelerates the hardening process allowing a faster layer-by-layer deposition. This low cost and eco-friendly preliminary earth-based composite can be used for 3D printing applications in the construction industry.
Genesis of non-uniformity of plasma fluxes over emissive wall in low-temperature plasmas
Authors: Schweigert I V , Walker M L R , Keidar M
Published: November 2019

Origins of spatial modulation of stationary electron and ion currents to the wall in discharge plasma with/without magnetic field at low gas pressure are studied in the experiments and 2D PIC MCC simulations. It is shown that a non-uniformity of ion and electron fluxes to the wall is induced by (a) a non-planar topology on the emissive wall, (b) a difference in the secondary electron emission yields of materials in segmented wall or (c) an inclination of the external magnetic field. The transition in the sheath structure over the grooved emissive surface from a developed sheath to a collapsed one caused by the increase of electron energy enlarges the alteration of the ion and electron currents over the grooved or segmented surfaces. The experimental study of the plasma-emissive wall sheath transition was carried out with hexagonal boron nitride wall samples grooved with the characteristic size of 1 mm and 5 mm, which is about of the Debye length. In kinetic simulations, this phenomenon is analyzed in terms of the electron and ion energy distribution functions. An external oblique magnetic field applyed to the dc discharge is found to redistribute the plasma and the periodical structure with the spikes of electron and ion densities forms This phenomena causes the non-uniform spatial distribution of electron and ion currents to the wall. The spikes in electron and ion densities became more pronounced with an increase of magnetic field incidence angle.
Sonographic Analysis of the Upper Labial Orbicularis Oris and Its Clinical Implications
Authors: Park Hyun Jin , Lee Kyu-Lim , Gil Young-Chun , Lee Ji-Hyun , Hu Kyung-Seok , Kim Hee-Jin
Published: November 2019

Background

Purse string lips, which include the vertical wrinkles over the lips, are frequently observed in aged individuals. Botulinum toxin and fillers are routinely injected into these areas to remove the wrinkles; however, the anatomy of the orbicularis oris muscle (OOr) near the vermilion border area has not been well defined.

Objectives

The aim of this study was therefore to identify any morphological differences of the upper OOr via sonographic imaging.

Methods

The upper lip muscles as observed utilizing an ultrasound device were divided into 2 muscles (pars peripheralis and pars marginalis) that were subsequently divided into a further 2 types (Type I and Type II) associated with the development of the pars marginalis. Type II was further divided into Type IIa and Type IIb depending on whether the muscle fibers were well developed and connected.

Results

On the midline of the lip, Type I, in which the pars marginalis was rarely observed and only appeared in traces, was observed in 20.0% of the volunteers. Type IIa, in which the pars marginalis was well-developed and appeared continuous, was observed in 42.9% of the volunteers. Type IIb, in which the pars marginalis was observed but appeared discontinuous, was observed in 37.1% of the volunteers.

Conclusions

The shapes of the upper pars marginalis of the OOr varied markedly between volunteers. Type classification of the OOr based on its shape and the lip appearance serves as a reliable source of reference information to be utilized when injecting botulinum toxin into the upper lip.
MotifCNN-fold: protein fold recognition based on fold-specific features extracted by motif-based convolutional neural networks
Authors: Li Chen-Chen , Liu Bin
Published: November 2019

Protein fold recognition is one of the most critical tasks to explore the structures and functions of the proteins based on their primary sequence information. The existing protein fold recognition approaches rely on features reflecting the characteristics of protein folds. However, the feature extraction methods are still the bottleneck of the performance improvement of these methods. In this paper, we proposed two new feature extraction methods called MotifCNN and MotifDCNN to extract more discriminative fold-specific features based on structural motif kernels to construct the motif-based convolutional neural networks (CNNs). The pairwise sequence similarity scores calculated based on fold-specific features are then fed into support vector machines to construct the predictor for fold recognition, and a predictor called MotifCNN-fold has been proposed. Experimental results on the benchmark dataset showed that MotifCNN-fold obviously outperformed all the other competing methods. In particular, the fold-specific features extracted by MotifCNN and MotifDCNN are more discriminative than the fold-specific features extracted by other deep learning techniques, indicating that incorporating the structural motifs into the CNN is able to capture the characteristics of protein folds.
Mass spectrometry–based protein identification in proteomics—a review
Authors: Noor Zainab , Ahn Seong Beom , Baker Mark S , Ranganathan Shoba , Mohamedali Abidali
Published: November 2019

Statistically, accurate protein identification is a fundamental cornerstone of proteomics and underpins the understanding and application of this technology across all elements of medicine and biology. Proteomics, as a branch of biochemistry, has in recent years played a pivotal role in extending and developing the science of accurately identifying the biology and interactions of groups of proteins or proteomes. Proteomics has primarily used mass spectrometry (MS)-based techniques for identifying proteins, although other techniques including affinity-based identifications still play significant roles. Here, we outline the basics of MS to understand how data are generated and parameters used to inform computational tools used in protein identification. We then outline a comprehensive analysis of the bioinformatics and computational methodologies used in protein identification in proteomics including discussing the most current communally acceptable metrics to validate any identification.
Estimation of marginal causal effects in the presence of confounding by cluster
Authors: Sjölander Arvid
Published: November 2019

A popular way to control for unmeasured confounders is to utilize clusters (e.g. sets of siblings), in which a potentially large set of confounders are constant. By estimating the exposure–outcome association within clusters, rather than between unrelated subjects, all cluster-constant confounders are implicitly controlled for. To analyze such clustered data, it is common to use fixed effects models, which absorb all cluster-constant confounders into a cluster-specific intercept. In this article, we show how linear and log-linear fixed effects models can be used to estimate marginal counterfactual means. These counterfactual means can be estimated and presented for each exposure level separately, or contrasted to form a wide range of marginal causal effects. For binary outcomes, we propose to estimate marginal causal effects with marginal logistic between-within models. These models include a constant intercept common for all clusters, and control for unmeasured cluster-constant confounders by adding the mean exposure level in each cluster to the model. We illustrate the proposed methods by re-analyzing data from a co-twin control study on birth weight and Attention-Deficit/Hyperactivity Disorder.
Fluorescent Flags: Black Power, Publicity, and Counternarratives in Go-Go Street Posters in the 1980s
Authors: Hopkinson Natalie
Published: November 2019

This semiotic landscape analysis probes urban patterns of racial placement and displacement through an archive of music publicity posters. The music poster archive is a site to map the so-called “Chocolate City” of Washington, D.C., in the 1980s, explore its calendars, rhythms, textures, communication technology, history and movements of segregated black life. These posters advertising go-go music, the city's indigenous black popular music, asserted a territory of black economic, cultural and political power. They resisted the narrative of a sanitized “White City” designed for white tourists. The city's cultural entrepreneurs challenged false dominant narratives and public policies that marginalized black urban culture as dangerous and deviant. A crack-down on postering in the late 1990s was an early harbinger of gentrification.
Effectiveness and safety of edoxaban in patients with atrial fibrillation: data from the Danish Nationwide Cohort
Authors: Nielsen Peter Brønnum , Larsen Torben Bjerregaard , Skjøth Flemming , Søgaard Mette , Lip Gregory Y H
Published: November 2019

Aims 

Edoxaban treatment for stroke prevention in atrial fibrillation (AF) has mainly been investigated in randomized controlled trials, and data reflecting clinical practice are limited. We ascertained the clinical effectiveness and safety of edoxaban 30 and 60 mg once daily among Danish patients with AF.

Methods and results 

This was an observational study based on Danish nationwide registries collecting information for administrative purposes. From June 2016 through November 2018, we identified 3405 patients initiating edoxaban. After exclusions, 2285 AF patients were followed for the effectiveness outcome of thromboembolism (ischaemic stroke and/or systemic embolism) and bleeding outcomes (composite of major bleeding, gastrointestinal bleeding, and intracranial haemorrhage), as well as bleeding requiring hospitalization. Population mean age was 75 years and 43% were female; 643 patients received the 30 mg edoxaban dosage regimen and 1642 initiated 60 mg edoxaban. During follow-up, we observed 41 thromboembolic events and 89 bleeding events of which 40 events required hospitalization. Among patients with 30 mg edoxaban, the rate (per 100 person-years) of thromboembolism was 2.07 vs. 1.62 for 60 mg edoxaban. Rates of bleeding were similar for the two dosages at ∼3.85. Bleeding requiring hospitalization occurred at a rate of 1.74 for 30 mg edoxaban and 1.69 with 60 mg edoxaban.

Conclusion 

In this nationwide cohort of Caucasian AF patients treated with edoxaban for stroke prevention, the clinical effectiveness and safety were in line with data from the ENGAGE AF-TIMI 48 trial. Studies investigating comparative effectiveness and safety for edoxaban in comparison with other choices of antithrombotic treatment options are needed.
Bioinformatic and genetic characterization of three genes localized adjacent to the major replication origin of Haloferax volcanii
Authors: Wolters Maike , Borst Andreas , Pfeiffer Friedhelm , Soppa Jörg
Published: November 2019

In haloarchaea, a cluster of three genes is localized directly adjacent to the major replication origin, and, hence, the encoded proteins were annotated as ‘origin-associated proteins’ (Oap). However, prior to this study, no experimental data were available for these conserved hypothetical proteins. Bioinformatic analyses were performed, which unraveled, 1) that the amino acid composition of all three proteins deviate from the average, 2) that OapA is a GTP-binding protein, 3) that OapC has an N-terminal zinc-finger motif, and 4) that the sequences of OapA and OapB are highly conserved while OapC conservation is restricted to short terminal regions. Surprisingly, transcript analyses revealed a complex expression pattern of the oap genes, despite their close proximity. Based on the high degree of conservation in haloarchaea it could be expected that one or more of the oap genes might be essential. However, in frame deletion mutants of all three genes could be readily generated, were viable, and had no growth phenotype. In addition, quantification of the chromsome copy numbers revealed no significant differences between the wild-type and the three mutants. In summary, experimental evidence is inconsistent with Oap proteins being essential for or involved in key steps of DNA replication.
Detection of carotenoids of halophilic prokaryotes in solid inclusions inside laboratory-grown chloride and sulfate crystals using a portable Raman spectrometer: applications for Mars exploration
Authors: Culka Adam , Košek Filip , Oren Aharon , Mana Lily , Jehlička Jan
Published: November 2019

Inclusions in evaporitic minerals sometimes contain remnants of microorganisms or biomarkers, which can be considered as traces of life. Raman spectroscopy with resonance enhancement is one of the best analytical methods to search for such biomarkers in places of interest for astrobiology, including the surface and near subsurface of planet Mars. Portable Raman spectrometers are used as training tools for detection of biomarkers. Investigations of the limits and challenges of detecting biomolecules in crystals using Raman spectroscopy is important because natural occurrences often involve mineral assemblages as well as their fluid and solid inclusions. A portable Raman spectrometer with 532 nm excitation was used for detection of carotenoid biomarkers: salinixanthin of Salinibacter ruber (Bacteroidetes) and α-bacterioruberin of Halorubrum sodomense (Halobacteria) in laboratory-grown artificial inclusions in compound crystals of several chlorides and sulfates, simulating entrapment of microorganisms in evaporitic minerals. Crystals of halite (NaCl), sylvite (KCl), arcanite (K2SO4) and tschermigite ((NH4)Al(SO4)2·12H2O) were grown from synthetic solutions that contained microorganisms. A second crystalline layer of NaCl or K2SO4 was grown subsequently so that primary crystals containing microorganisms are considered as solid inclusions. A portable Raman spectrometer with resonance enabling excitation detected signals of both carotenoid pigments. Correct positions of diagnostic Raman bands corresponding to the specific carotenoids were recorded.
Diet and Nutrition Risk Affect Mobility and General Health in Osteoarthritis: Data from the Canadian Longitudinal Study on Aging
Authors: Chopp-Hurley Jaclyn N , Wiebenga Emily G , Keller Heather H , Maly Monica R
Published: November 2019

Background

This study examined whether aspects of diet and nutrition risk explain variance in physical capacity and general health, after controlling for covariates, in Canadian adults with osteoarthritis (OA).

Methods

This was a cross-sectional study of baseline data from the Canadian Longitudinal Study on Aging (CLSA). Data from 1,404 participants with hand, hip, and/or knee OA were included. A series of regression analyses were conducted with independent variables of food intake (fiber and high calorie snack intake) and nutrition risk; and dependent variables of physical capacity and general health. Physical capacity was characterized through grip strength and a pooled index of four mobility tests. General health was characterized through an index of self-reported general health, mental health, and healthy aging.

Results

Higher fiber intake was related to greater mobility (p = .01). Food intake was not related to any other outcome. Nutrition risk was significantly associated with mobility (p < .001) and general health (p < .001); those with a high nutrition risk classification had poorer general health (p < .001, d = 0.65) than those at low nutrition risk. As well, those with moderate nutrition risk had poorer general health than those with low nutrition risk (p = .001, d = 0.31).

Conclusions

Nutrition risk screening for older adults with OA provides insight into behavioral characteristics associated with reduced mobility and poorer general health. Also, those consuming greater amounts of fiber demonstrated better mobility. Thus, this research suggests that quality of diet and nutritional behaviors can impact both physical and mental aspects of health in those with OA.
Detection of 3-D inhomogeneities of the medium at magnetotelluric sounding in the Arctic (numerical experiment)
Authors: Plotkin Valery V , Mogilatov Vladimir S , Gurev Vladimir A , Potapov Vladimir V
Published: November 2019

The magnetotelluric sounding (MTS) conducted on drifting ice floes in the Arctic is of particular interest for detection of 3-D inhomogeneities in crustal conductivity. Their manifestations in behaviour of standard magnetotelluric curves are shielded by the well conducting layers of seawater and sediment. As target objects, these inhomogeneities are shown as small changes (only hundredths of per cent) in apparent resistivity, and as very weak variations of vertical magnetic field component. Therefore, accounting for additional data on the vertical electric field component or the electric field potential of the transverse magnetic (TM) mode is of interest. For recording the TM-mode potential, we offer to use the circular electric dipole (CED) located on the ice surface as a receiver in MTS. We investigate possibilities of crustal 3-D inhomogeneity detection using the TM-mode potential received with the CED. A numerical experiment showed that the potential of electric field of the TM-mode on the ice surface reaches values suitable for detection. Examples of the inverse problem solution using synthetic data on the TM-mode field are presented. We found that the information on the depth of 3-D object could be obtained by the analytical continuation of the profile data on the TM-mode potential. Using the MTU-5 Phoenix Geophysics stations for the CED system, we carried out preliminary measurements on the ice surface on the Ob river. We checked the measurement results of the TM-mode potential using the MTS data obtained earlier near the CED system. We compared results of the TM-mode potential calculation for the found 3-D-medium model to the CED experimental data. Our results showed that the potential dependences on the period measured by the СED and those obtained for the 3-D model have similar characteristics. We believe recording the TM-mode potential in the Arctic allows to reveal the existence and characteristics of crustal conductivity 3-D heterogeneities.
Memory of Violence and Drama in Peru: The Experience of the Truth Commission and Grupo Cultural Yuyachkani – Violence and Dehumanization
Authors: Lerner Febres Salomón
Published: November 2019

ABSTRACT∞

The theater collective Yuyachkani, a Quechua word meaning ‘I am remembering,’ were not strangers to the history the Peruvian Truth and Reconciliation Commission was rediscovering when they offered to contribute to the transitional justice process. They had been following the violence in Peru through their various performances and felt highly committed to the process of truth seeking and the search for reconciliation. The performances of Yuyachkani do not seek to reproduce the facts. They do not commit the naive error of certain realist art efforts, to portray social violence per se in a supposedly concrete way. Their tools are rather the symbols through which culture is expressed. It is not a matter so much of reproducing the facts as of producing effects, to reveal and convey the tragedies of Peruvian society. Performance heightens the senses and opens our imaginations to the deep truths that have been lost among the facts.
“Just tell me what’s going on”: The views of parents of children with genetic conditions regarding the research use of their child’s electronic health record
Authors: Andrews Sara M , Raspa Melissa , Edwards Anne , Moultrie Rebecca , Turner-Brown Lauren , Wagner Laura , Alvarez Rivas Alexandra , Frisch Mary Katherine , Wheeler Anne C
Published: November 2019

Objective

The purpose of this study was to understand the ethical, legal, and social issues described by parents of children with known or suspected genetic conditions that cause intellectual and developmental disabilities regarding research use of their child’s electronic health record (EHR).

Materials and Methods

We conducted 4 focus groups with parents of children with a known (n = 12) or suspected (n = 11) genetic condition, as well as 2 comparison groups with parents who had a child with no known genetic condition (n = 15). Focus group transcripts were coded and analyzed using directed content analysis.

Results

After weighing the risks and benefits, parents of children with known or suspected genetic conditions were willing to share their child’s EHR for research studies under certain conditions. Preferences were for studies conducted by universities or nonprofits that might benefit their child or others with the same condition. Parents also valued return of research results.

Discussion

Trust, transparency, altruism, and concerns about privacy emerged as factors that affect parents’ willingness to allow research use of their child’s EHR.

Conclusion

Researchers should consider how to build trust with parents by increasing transparency of the research process and explaining specifically how they will ensure the confidentiality of EHR data.
The three-dimensional finite element forward modelling of complex excitation source NMR
Authors: Qi Zhipeng , Li Xiu , Fan Kerui , Zhi Qingquan
Published: November 2019

Traditional nuclear magnetic resonance (NMR) is mainly applied to horizontal ground and one-dimensional electrical structures. However, calculations of the excitation fields rarely consider the three-dimensional electrical changes of the subsurface medium and undulating terrain, or the deformations caused by emission sources. Therefore, to analyse the influences of terrain fluctuations, emission source deformations and three-dimensional electrical changes on NMR, three-dimensional finite element forward modelling of undulating terrain NMR was conducted in this study. First, based on a scalar finite element method, the direct calculations of the excited magnetic fields of a three-dimensional electrical medium were realised, which improved calculation accuracy by avoiding the finite element calculations of magnetic vector potential and vector on the magnetic field. During the source loading process, the equivalent thin wire source of the pseudo δ function was used to load the source function directly into the equation for the purpose of achieving total field calculations. This was completed to enable the calculations to be applied to any shape of the transmitting loop and undulating terrain. Then, the components of the excitation magnetic fields perpendicular to the geomagnetic fields were calculated using the rotation matrix. Finally, the NMR sensitivity function and 3D responses were calculated. The calculations of the excitation magnetic fields were verified using a uniform half-space model. The overall algorithm was tested by the nuclear magnetic responses of the layered medium. Also, a typical undulating terrain model was adopted and the complex excitation source NMR was simulated using the algorithm proposed in this study. The algorithm provided a three-dimensional forward basis for the NMR inversion in the cases of determining the electrical medium for the subsequent undulating terrain.
Did Premodern Muslims Distinguish the Religious and Secular? The Dīn–Dunyā Binary in Medieval Islamic Thought
Authors: Abbasi Rushain
Published: November 2019

This article challenges the widely-held belief, within and outside academia, that premodern Muslims did not make a distinction between the religious and secular. I explore the issue by examining several usages of the dīn–dunyā binary across diverse genres of medieval Islamic writings and assessing to what extent it accords with or diverges from the categories of the religious and secular as commonly used in the modern Western world. I situate my particular counter-claim vis-à-vis the argument against the relevance of the religious–secular distinction to Islam made by Shahab Ahmed in his, What is Islam? The Importance of Being Islamic. My findings show that contrary to Ahmed and the broader consensus, premodern Muslims did in fact view the world in terms of distinct spheres of religion and non-religion and that this distinction was used to understand phenomena as diverse and significant as politics and prophethood. Nevertheless, the two categories interacted in a way distinct from the common understanding of the two in the modern world insofar as, under the medieval Islamic conception, it was religion that regulated the secular. My article will make sense of these similarities and differences in an effort to present an indigenous account of the religious–secular dialectic in medieval Islam, one that problematizes the current standard account which holds that these categories were invented within the modern West.
Ileectomy performed on a case of adult intussusception due to inversion of Meckel’s diverticulum
Authors: Abe Iku , Saito Masaaki , Ikeda Taro , Fukuda Rintaro , Tanaka Akira , Rikiyama Toshiki
Published: November 2019

We report a rare case of adult intussusception caused by an inverted Meckel’s diverticulum with ectopic pancreatic tissue. A 43-year-old woman was referred to our hospital with complaints of abdominal distention, intermittent abdominal pain and nausea that she experienced 3 months ago. Abdominal computed tomography scans demonstrated ileo-ileal intussusception that contained a tumor with fat density as the lead point. Laparoscopic-assisted partial resection of the small intestine was performed. The surgical specimen showed an elongated polypoid lesion invaginated into the intestinal tract indicating an inverted Meckel’s diverticulum. Pathological findings showed a true diverticulum that ran antimesentrically, with tall columnar epithelium, a mucous gland and an islet of Langerhans. The postoperative period was uneventful, and she was discharged on the ninth postoperative day.
Suprathermal plasma distribution functions with relativistic cut-offs
Authors: Fahr H-J , Heyl M
Published: November 2019

In typical plasma physics scenarios, when treated on kinetic levels, distribution functions with suprathermal wings are obtained. This raises the question of how the associated typical velocity moments, which are needed to arrive at magnetohydrodynamic plasma descriptions, may appear. It has become evident that the higher velocity moments in particular, for example the pressure or heat transport, which are constructed as integrations of the distribution function, contain unphysical contributions from particles with velocities greater than the velocity of light. In what follows, we discuss two possibilities to overcome this problem. One is to calculate a maximal, physically permitted, upper velocity, which can be realized in view of the underlying energization processes, and to stop the integration there. The other is to modify the distribution function relativistically so that no particles with superluminal (v ≥ c) velocities appear. On the basis of a typical collision-free plasma scenario, like the plasma in the heliosheath, we obtain the corresponding expressions for electron and proton pressures and can show that in both cases the pressures are reduced compared with their classical values; however, electrons experience a stronger reduction than protons. When calculating pressure ratios, it turns out that these are of the same order of magnitude regardless of which of the two methods is used. The electron, as the low-mass particle, undergoes the more pronounced pressure reduction. It may turn out that electrons and protons constitute about equal pressures in the heliosheath, implying that no pressure deficit need be claimed here.
On the origin of the chemical bimodality of disc stars: a tale of merger and migration
Authors: Buck Tobias
Published: November 2019

The Milky Way’s (MW) stellar disc exhibits a bimodality in the [Fe/H] versus [α/Fe] plane, showing a distinct high- and low-α sequences whose origin is still under debate. We examine the [Fe/H]–[α/Fe] abundance plane in cosmological hydrodynamical simulations of MW-like galaxies from the NIHAO-UHD project and show that the bimodal α-sequence is a generic consequence of a gas-rich merger at some time in the Galaxy’s evolution. The high-α sequence evolves first in the early galaxies, extending to high metallicities, while it is the low-α sequence that is formed after the gas-rich merger. The merger brings in fresh metal-poor gas diluting the interstellar medium’s metallicity while keeping the [α/Fe] abundance almost unchanged. The kinematic, structural, and spatial properties of the bimodal α-sequence in our simulations reproduces that of observations. In all simulations, the high-α disc is old, radially concentrated towards the galaxy’s centre and shows large scale heights. In contrast, the low-α disc is younger, more radially extended and concentrated to the disc mid-plane. Our results show that the abundance plane is well described by these two populations that have been distributed radially across the disc by migration: at present day in the solar neighbourhood, low-α stars originate from both the inner and outer discs, while most of the high-α stars have migrated from the inner disc. We show that age dating the stars in the [Fe/H]–[α/Fe] plane can constrain the time of the low-α sequence forming merger and conclude that α-bimodality is likely a not uncommon feature of disc galaxies.
Examining the physical conditions of a warm corona in active galactic nuclei accretion discs
Authors: Ballantyne D R
Published: November 2019

A warm corona at the surface of an accretion disc has been proposed as a potential location for producing the soft excess commonly observed in the X-ray spectra of active galactic nuclei (AGNs). In order to fit the observed data, the gas must be at temperatures of ∼1 keV and have an optical depth of τT ≈ 10–20. We present one-dimensional calculations of the physical conditions and emitted spectra of a τT = 10 or 20 gas layer subject to illumination from an X-ray power law (from above), a blackbody (from below), and a variable amount of internal heating. The models show that a warm corona with kT ∼ 1 keV can develop, producing a strong Comptonized soft excess, but only if the internal heating flux is within a relatively narrow range. Similarly, if the gas density of the layer is too large then efficient cooling will stop a warm corona from forming. The radiation from the hard X-ray power law is crucial in producing a warm corona, indicating that a warm and hot corona may coexist in AGN accretion discs, and their combined effect leads to the observed soft excess. Intense heating of a warm corona leads to steep X-ray spectra with ionized Fe K α lines, similar to those seen in some narrow-line Seyfert 1 galaxies.
Estimating redshift distributions using hierarchical logistic Gaussian processes
Authors: Rau Markus Michael , Wilson Simon , Mandelbaum Rachel
Published: November 2019

This work uses hierarchical logistic Gaussian processes to infer true redshift distributions of samples of galaxies, through their cross-correlations with spatially overlapping spectroscopic samples. We demonstrate that this method can accurately estimate these redshift distributions in a fully Bayesian manner jointly with galaxy-dark matter bias models. We forecast how systematic biases in the redshift-dependent galaxy-dark matter bias model affect redshift inference. Using published galaxy-dark matter bias measurements from the Illustris simulation, we compare these systematic biases with the statistical error budget from a forecasted weak gravitational lensing measurement. If the redshift-dependent galaxy-dark matter bias model is mis-specified, redshift inference can be biased. This can propagate into relative biases in the weak lensing convergence power spectrum on the 10–30 per cent level. We, therefore, showcase a methodology to detect these sources of error using Bayesian model selection techniques. Furthermore, we discuss the improvements that can be gained from incorporating prior information from Bayesian template fitting into the model, both in redshift prediction accuracy and in the detection of systematic modelling biases.
Automatic detection of full ring galaxy candidates in SDSS
Authors: Shamir Lior
Published: November 2019

A full ring is a form of galaxy morphology that is not associated with a specific stage on the Hubble sequence. Digital sky surveys can collect many millions of galaxy images, and therefore even rare forms of galaxies are expected to be present in relatively large numbers in image data bases created by digital sky surveys. Sloan Digital Sky Survey (SDSS) data release (DR) 14 contains ∼2.6 × 106 objects with spectra identified as galaxies. The method described in this paper applied automatic detection to identify a set of 443 ring galaxy candidates, 104 of them were already included in the Buta  + 17 catalogue of ring galaxies in SDSS, but the majority of the galaxies are not included in previous catalogues. Machine analysis cannot yet match the superior pattern recognition abilities of the human brain, and even a small false positive rate makes automatic analysis impractical when scanning through millions of galaxies. Reducing the false positive rate also increases the true negative rate, and therefore the catalogue of ring galaxy candidates is not exhaustive. However, due to its clear advantage in speed, it can provide a large collection of galaxies that can be used for follow-up observations of objects with ring morphology.
Mechanism of conditional partner selectivity in MITF/TFE family transcription factors with a conserved coiled coil stammer motif
Authors: Pogenberg Vivian , Ballesteros-Álvarez Josué , Schober Romana , Sigvaldadóttir Ingibjörg , Obarska-Kosinska Agnieszka , Milewski Morlin , Schindl Rainer , Ögmundsdóttir Margrét Helga , Steingrímsson Eiríkur , Wilmanns Matthias
Published: November 2019

Interrupted dimeric coiled coil segments are found in a broad range of proteins and generally confer selective functional properties such as binding to specific ligands. However, there is only one documented case of a basic-helix–loop–helix leucine zipper transcription factor—microphthalmia-associated transcription factor (MITF)—in which an insertion of a three-residue stammer serves as a determinant of conditional partner selectivity. To unravel the molecular principles of this selectivity, we have analyzed the high-resolution structures of stammer-containing MITF and an engineered stammer-less MITF variant, which comprises an uninterrupted symmetric coiled coil. Despite this fundamental difference, both MITF structures reveal identical flanking in-phase coiled coil arrangements, gained by helical over-winding and local asymmetry in wild-type MITF across the stammer region. These conserved structural properties allow the maintenance of a proper functional readout in terms of nuclear localization and binding to specific DNA-response motifs regardless of the presence of the stammer. By contrast, MITF heterodimer formation with other bHLH-Zip transcription factors is only permissive when both factors contain either the same type of inserted stammer or no insert. Our data illustrate a unique principle of conditional partner selectivity within the wide arsenal of transcription factors with specific partner-dependent functional readouts.
Heterochromatin protein 1α interacts with parallel RNA and DNA G-quadruplexes
Authors: Roach Ruby J , Garavís Miguel , González Carlos , Jameson Geoffrey B , Filichev Vyacheslav V , Hale Tracy K
Published: November 2019

The eukaryotic genome is functionally organized into domains of transcriptionally active euchromatin and domains of highly compact transcriptionally silent heterochromatin. Heterochromatin is constitutively assembled at repetitive elements that include the telomeres and centromeres. The histone code model proposes that HP1α forms and maintains these domains of heterochromatin through the interaction of its chromodomain with trimethylated lysine 9 of histone 3, although this interaction is not the sole determinant. We show here that the unstructured hinge domain, necessary for the targeting of HP1α to constitutive heterochromatin, recognizes parallel G-quadruplex (G4) assemblies formed by the TElomeric Repeat-containing RNA (TERRA) transcribed from the telomere. This provides a mechanism by which TERRA can lead to the enrichment of HP1α at telomeres to maintain heterochromatin. Furthermore, we show that HP1α binds with a faster association rate to DNA G4s of parallel topology compared to antiparallel G4s that bind slowly or not at all. Such G4–DNAs are found in the regulatory regions of several oncogenes. This implicates specific non-canonical nucleic acid structures as determinants of HP1α function and thus RNA and DNA G4s need to be considered as contributors to chromatin domain organization and the epigenome.
Composition and processing activity of a semi-recombinant holo U7 snRNP
Authors: Bucholc Katarzyna , Aik Wei Shen , Yang Xiao-cui , Wang Kaituo , Zhou Z Hong , Dadlez Michał , Marzluff William F , Tong Liang , Dominski Zbigniew
Published: November 2019

In animal cells, replication-dependent histone pre-mRNAs are cleaved at the 3′ end by U7 snRNP consisting of two core components: a ∼60-nucleotide U7 snRNA and a ring of seven proteins, with Lsm10 and Lsm11 replacing the spliceosomal SmD1 and SmD2. Lsm11 interacts with FLASH and together they recruit the endonuclease CPSF73 and other polyadenylation factors, forming catalytically active holo U7 snRNP. Here, we assembled core U7 snRNP bound to FLASH from recombinant components and analyzed its appearance by electron microscopy and ability to support histone pre-mRNA processing in the presence of polyadenylation factors from nuclear extracts. We demonstrate that semi-recombinant holo U7 snRNP reconstituted in this manner has the same composition and functional properties as endogenous U7 snRNP, and accurately cleaves histone pre-mRNAs in a reconstituted in vitro processing reaction. We also demonstrate that the U7-specific Sm ring assembles efficiently in vitro on a spliceosomal Sm site but the engineered U7 snRNP is functionally impaired. This approach offers a unique opportunity to study the importance of various regions in the Sm proteins and U7 snRNA in 3′ end processing of histone pre-mRNAs.
The Risk of Peripheral Nerve Tumor Biopsy in Suspected Benign Etiologies
Authors: Perez-Roman Roberto J , Shelby Burks S , Debs Luca , Cajigas Iahn , Levi Allan D
Published: November 2019

BACKGROUND

Peripheral nerve sheath tumors (PNSTs) are tumors with unique clinical and imaging features that present to a variety of physicians. These lesions are often referred for biopsy, which can put nerve fascicles at risk. Preoperative biopsy may cause distortion of normal anatomic planes, making definitive resection difficult.

OBJECTIVE

To evaluate the neurological risks of preoperative biopsy in benign PNSTs.

METHODS

Surgical cases collected retrospectively using a prospectively established database of PNSTs treated by a single surgeon between 1997 and 2019. Patients were dichotomized depending on preoperative biopsy. The effects of biopsy were assessed via history and physical examination both pre- and postdefinitive resection.

RESULTS

A total of 151 cases were included. Only 23.2% (35) of patients underwent preoperative biopsy, but 42.9% of these experienced new or worsening neurological examination immediately following biopsy. After definitive resection, the rate of neurological deficit was significantly different between the 2 groups with 60% of biopsy patients and 19% of those patients not biopsied experiencing decline in examination (F = 25.72, P < .001). Odds ratio for any postoperative deficit for biopsy was 6.40 (CI [2.8, 14.55], P < .001). Univariate logistic regression of neurological deficit with patient age, sex, tumor type, and biopsy status showed that only biopsy was associated with the occurrence of any postoperative deficit.

CONCLUSION

Biopsy of benign PNSTs is associated with a high rate of neurological deficit both immediately following the procedure and after definitive resection. Careful selection is imperative prior to proceeding with biopsy of nerve sheath tumors exhibiting benign features given the unacceptably high rate of neurological decline.