bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical behavior and AE and EMR characteristics of natural and saturated coal samples in the indirect tensile process
Authors: Shen Rongxi , Li Hongru , Wang Enyuan , Li Dexing , Hou Zhenhai , Zhang Xuan , Han Xu 
Published: July 2019

AbstractThe differences between mechanical properties and acoustic emission (AE) and electromagnetic radiation (EMR) characteristics of natural coal samples and saturated coal samples were analyzed by performing indirect tensile experiments. The experimental results show that coal samples go through four stages: compaction, elastic deformation, plastic deformation and failure. There is good correspondence between AE and EMR signals and the damage to coal samples. Under the action of water, tension strength of samples is reduced, while the plasticity is enhanced; also, the softening coefficient of tensile strength becomes 0.65. The saturated coal samples have a longer plastic stage and a more obvious AE quiet period. The damage to natural coal samples is tension damage, while that of saturated coal samples is due to tension and shear damage, which is more sufficient and irregular. EMR is still remarkable when AE is in a quiet period, and EMR is better for the precursor of rupture. Water weakens the generation and propagation of AE and EMR signals, especially in the earlier stage. AE and EMR damage factor D, defined by AE and EMR counts, has a better description of the damage degree in the indirect tensile process. This study is of great significance for research on the damage mechanism of water-bearing coal, the stability monitoring of water-bearing coals in the actual engineering process and the effect evaluation of hydraulic flushing.
Description of a New Species of Forcipomyia (Forcipomyia) (Diptera: Ceratopogonidae) and a Key to Species of the Subgenus From the Chinese Mainland
Authors: Duan Chen , Jiang Xiao Hong , Han Xiao Jing , Hou Xiao Hui 
Published: July 2019

Abstract
Forcipomyia (Forcipomyia) makanensis Hou sp. n. (Diptera: Ceratopogonidae) is described and illustrated based on male and female specimens from China. It is characterized by the male aedeagus triangular, with large cone-shaped process at apex, basal arch high, basal arm slender and curved, parameres separate narrower distance at base, cone-shaped apically, and the female subgenital plate pliers-shaped, without lateral process, with two spermathecae, oval, nearly equal. The new species is compared with the similar congener F. (Forcipomyia) lochmocola Zou and Yu, 1991. We provide separate keys for identification of the males and females of the species of subgenus F. (Forcipomyia) Meigen in China.
The evolution of kicked stellar-mass black holes in star cluster environments - II. Rotating star clusters
Authors: Webb Jeremy J , Leigh Nathan W C , Serrano Roberto , Bellovary Jillian , Ford K E Saavik , McKernan Barry , Spera Mario , Trani Alessandro A 
Published: July 2019

Abstract
In this paper, we continue our study on the evolution of black holes (BHs) that receive velocity kicks at the origin of their host star cluster potential. We now focus on BHs in rotating clusters that receive a range of kick velocities in different directions with respect to the rotation axis. We perform N-body simulations to calculate the trajectories of the kicked BHs and develop an analytic framework to study their motion as a function of the host cluster and the kick itself. Our simulations indicate that for a BH that is kicked outside of the cluster’s core, as its orbit decays in a rotating cluster the BH will quickly gain angular momentum as it interacts with stars with high rotational frequencies. Once the BH decays to the point where its orbital frequency equals that of local stars, its orbit will be circular and dynamical friction becomes ineffective since local stars will have low relative velocities. After circularization, the BH’s orbit decays on a longer time-scale than if the host cluster was not rotating. Hence BHs in rotating clusters will have longer orbital decay times. The time-scale for orbit circularization depends strongly on the cluster’s rotation rate and the initial kick velocity, with kicked BHs in slowly rotating clusters being able to decay into the core before circularization occurs. The implication of the circularization phase is that the probability of a BH undergoing a tidal capture event increases, possibly aiding in the formation of binaries and high-mass BHs.
Ultra-deep tidal disruption events: prompt self-intersections and observables
Authors: Darbha Siva , Coughlin Eric R , Kasen Daniel , Nixon Chris 
Published: July 2019

ABSTRACT
A star approaching a supermassive black hole (SMBH) can be torn apart in a tidal disruption event (TDE). We examine ultra-deep TDEs, a new regime in which the disrupted debris approaches close to the black hole’s Schwarzschild radius, and the leading part intersects the trailing part at the first pericentre passage. We calculate the range of penetration factors β versus SMBH masses M that produce these prompt self-intersections using a Newtonian analytic estimate and a general relativistic (GR) geodesic model. We find that significant self-intersection of Solar-type stars requires β ∼ 50–127 for M/M⊙ = 104, down to β ∼ 5.6–5.9 forM/M⊙ = 106. We run smoothed particle hydrodynamic (SPH) simulations to corroborate our calculations and find close agreement, with a slightly shallower dependence on M. We predict that the shock from the collision emits an X-ray flare lasting t ∼ 2 s with L ∼ 1047 erg s−1 at E ∼ 2 keV, and the debris has a prompt accretion episode lasting t ∼ several minutes. The events are rare and occur with a rate $\dot{N} \lesssim 10^{-7}$ Mpc−3 yr−1. Ultra-deep TDEs can probe the strong gravity and demographics of low-mass SMBHs.
Clues to the nature of dark matter from first galaxies
Authors: Stoychev Boyan K , Dixon Keri L , Macciò Andrea V , Blank Marvin , Dutton Aaron A 
Published: July 2019

ABSTRACT
We use 38 high-resolution simulations of galaxy formation between redshift 10 and 5 to study the impact of a 3 keV warm dark matter (WDM) candidate on the high-redshift Universe. We focus our attention on the stellar mass function and the global star formation rate and consider the consequences for reionization, namely the neutral hydrogen fraction evolution and the electron scattering optical depth. We find that three different effects contribute to differentiate warm and cold dark matter (CDM) predictions: WDM suppresses the number of haloes with mass less than few 109 M⊙; at a fixed halo mass, WDM produces fewer stars than CDM, and finally at halo masses below 109 M⊙, WDM has a larger fraction of dark haloes than CDM post-reionization. These three effects combine to produce a lower stellar mass function in WDM for galaxies with stellar masses at and below 107 M⊙. For z > 7, the global star formation density is lower by a factor of two in the WDM scenario, and for a fixed escape fraction, the fraction of neutral hydrogen is higher by 0.3 at z ∼ 6. This latter quantity can be partially reconciled with CDM and observations only by increasing the escape fraction from 23 per cent to 34 per cent. Overall, our study shows that galaxy formation simulations at high redshift are a key tool to differentiate between dark matter candidates given a model for baryonic physics.
Formation and material supply of an active-region filament associated with newly emerging flux
Authors: Wang Jincheng , Yan Xiaoli , Guo Qiaoling , Kong Defang , Xue Zhike , Yang Liheng , Li Qiaoling 
Published: July 2019

ABSTRACT
With the observations of Solar Dynamics Observatory(SDO)/Atmospheric Imaging Assembly (AIA) 304 $\rm \mathring{\rm A}$ and New Vacuum Solar Telescope (NVST) H α bands, we present the formation of an active-region filament in active region NOAA 11903 during the period from 02:00 to 10:00 ut on 2013 November 25. A series of jets occurring in the vicinity of the south-western footpoint of the filament directly ejected cool and hot plasmas to filament height and supplied material for the filament. Some newly emerging flux is found in the vicinity of the south-western footpoint of the filament during these jets. In this paper, we mainly focus on the material supply for the formation of the filament. The plasma mass uploaded by the jets and the mass of the filament are estimated, which manifest the fact that the mass carried by the jets can supply sufficient material for the formation of the filament. We found two types of jets; one is H α jet, and the other is EUV jet. The significant finding is that some cool jets seen in the H α band but not in the SDO/AIA bands could also eject the cool material for the filament. These results suggest that cool plasma in the low atmosphere can be directly injected into the upper atmosphere and become the filament material by two types of jets. Moreover, the newly emerging flux with the non-potential field plays an important role in the appearance of the jets and the magnetic structure of the filament.
The first power spectrum limit on the 21-cm signal of neutral hydrogen during the Cosmic Dawn at z = 20–25 from LOFAR
Authors: Gehlot B K , Mertens F G , Koopmans L V E , Brentjens M A , Zaroubi S , Ciardi B , Ghosh A , Hatef M , Iliev I T , Jelić V , Kooistra R , Krause F , Mellema G , Mevius M , Mitra M , Offringa A R , Pandey V N , Sardarabadi A M , Schaye J , Silva M B , Vedantham H K , Yatawatta S 
Published: July 2019

ABSTRACT
Observations of the redshifted 21-cm hyperfine line of neutral hydrogen from early phases of the Universe such as Cosmic Dawn and the Epoch of Reionization promise to open a new window onto the early formation of stars and galaxies. We present the first upper limits on the power spectrum of redshifted 21-cm brightness temperature fluctuations in the redshift range z = 19.8–25.2 (54–68 MHz frequency range) using 14 h of data obtained with the LOFAR-Low Band Antenna (LBA) array. We also demonstrate the application of a multiple pointing calibration technique to calibrate the LOFAR-LBA dual-pointing observations centred on the North Celestial Pole and the radio galaxy 3C220.3. We observe an unexplained excess of $\sim 30\!-\!50{{\ \rm per\ cent}}$ in Stokes / noise compared to Stokes V for the two observed fields, which decorrelates on ≳12 s and might have a physical origin. We show that enforcing smoothness of gain errors along frequency direction during calibration reduces the additional variance in Stokes I compared Stokes V introduced by the calibration on sub-band level. After subtraction of smooth foregrounds, we achieve a 2σ upper limit on the 21-cm power spectrum of $\Delta _{21}^2 \lt (14561\, \text{mK})^2$ at $k\sim 0.038\, h\, \text{cMpc}^{-1}$ and $\Delta _{21}^2 \lt (14886\, \text{mK})^2$ at $k\sim 0.038 \, h\, \text{cMpc}^{-1}$ for the 3C220 and NCP fields respectively and both upper limits are consistent with each other. The upper limits for the two fields are still dominated by systematics on most k modes.
Planetesimals around stars with TESS (PAST) – I. Transient dimming of a binary solar analogue at the end of the planet accretion era
Authors: Gaidos E , Jacobs T , LaCourse D , Vanderburg A , Rappaport S , Berger T , Pearce L , Mann A W , Weiss L , Fulton B , Behmard A , Howard A W , Ansdell M , Ricker G R , Vanderspek R K , Latham D W , Seager S , Winn J N , Jenkins J M 
Published: July 2019

ABSTRACT
We report detection of quasi-periodic (1.5-d) dimming of HD 240779, the solar-mass primary in a 5 arcsec visual binary (also TIC 284730577), by the Transiting Exoplanet Survey Satellite. This dimming, as has been shown for other ‘dipper’ stars, is likely due to occultation by circumstellar dust. The barycentric space motion, lithium abundance, rotation, and chromospheric emission of the stars in this system point to an age of ≈125 Myr, and possible membership in the AB Doradus moving group. As such it occupies an important but poorly explored intermediate regime of stars with transient dimming between young stellar objects in star-forming regions and main-sequence stars, and between UX Orionis-type Ae/Be stars and M-type ‘dippers’. HD 240779, but not its companion BD+10 714B, has Wide-field Infrared Survey Explorer (WISE)-detected excess infrared emission at 12 and 22 μm indicative of circumstellar dust. We propose that infrared emission is produced by collisions of planetesimals during clearing of a residual disc at the end of rocky planet formation, and that quasi-periodic dimming is produced by the rapid disintegration of a ≳100 km planetesimal near the silicate evaporation radius. Further studies of this and similar systems will illuminate a poorly understood final phase of rocky planet formation like that which produced the inner Solar system.
The Battle of Muhammad Mahmoud Street in Cairo: The Politics and Poetics of Urban Violence in Revolutionary Time*
Authors: Ryzova Lucie 
Published: July 2019

Abstract
The battle of Muhammad Mahmoud Street in November 2011, pitching protestors against security forces in a five-day long stand-off, represented a crucial episode of Egypt's 25 January Revolution. Part riot and part carnival, this event opens up a number of questions for historians. This article examines the battle on three distinct scales, paying particular attention to time and temporality. The first scale is the battle's position within the temporality of the Egyptian revolution. The article argues that revolutionary situations are best understood through concepts of liminal time, and that the winter of 2011, rather than the initial stage of the Tahrir Square sit-in in January–February, represented the crucial phase of the revolutionary process in Egypt. A second scale zooms in on street action, focusing on the nexus of class, masculinity and urban violence. Here, raw experiences on the ground inform subjective meanings of ‘violence', ‘politics' and ‘revolution' from the perspective of those who were most directly involved in their making. These experiences also reveal different temporal horizons experienced by diverse participants, which, however, did not remain unchanged as events unfolded. The third scale is historically comparative, delving into spontaneously enacted riotous and carnivalesque urban violence as reflected in classic literature on riots and carnivals in different contexts. The battle of November 2011 allow us to see the generic affinity between these liminal events and the persistence of the riotous and carnivalesque within modern revolutionary situations, as it may help us understand the resurgence of riots within the contemporary world.
The Effect of Exercise on Cancer-Related Cognitive Impairment and Applications for Physical Therapy: Systematic Review of Randomized Controlled Trials
Authors: Campbell Kristin L , Zadravec Kendra , Bland Kelcey A , Chesley Elizabeth , Wolf Florian , Janelsins Michelle C 
Published: July 2019

Abstract

Background
Cancer-related cognitive impairment (CRCI), often called “chemo-brain” or “chemo-fog,” is a common side effect among adults with cancer, which can persist well after treatment completion. Accumulating evidence demonstrates exercise can improve cognitive function in healthy older adults and adults with cognitive impairments, suggesting exercise may play a role in managing CRCI.

Purpose
The purpose was to perform a systematic review of randomized controlled trials (RCTs) to understand the effect of exercise on CRCI.

Data Sources
Relevant literature was retrieved from CINAHL, Medline (Ovid), and EMBASE.

Study Selection
Eligible articles were RCTs that prescribed aerobic, resistance, combined aerobic/resistance, or mind-body (eg, yoga or Qigong) exercise during or following cancer treatment and included cognitive function outcome measures.

Data Extraction
Descriptive information and Cohen d effect sizes were directly extracted or calculated for included trials.

Data Synthesis
Twenty-nine trials were included in the final analysis. A statistically significant effect of exercise on self-reported cognitive function, both during and postadjuvant treatment, was reported in 12 trials (41%) (Cohen d range: 0.24–1.14), most commonly using the EORTC QLQ-C30. Ten trials (34%) performed neuropsychological testing to evaluate cognitive function; however, only 3 trials in women with breast cancer reported a significant effect of exercise (Cohen d range: 0.41–1.47).

Limitations
Few RCTs to date have evaluated the effect of exercise on CRCI as a primary outcome. Twenty-six trials (90%) in this review evaluated CRCI as secondary analyses.

Conclusions
Evidence supporting exercise as a strategy to address CRCI is limited. Future research evaluating CRCI as a primary outcome, including self-reported and objective measures, is needed to confirm the possible role of exercise in preventing and managing cognitive impairments in adults with cancer.
Scholarly understanding, mediating artefacts and the social impact of research in the educational sciences
Authors: Esko Terhi , Miettinen Reijo 
Published: July 2019

Abstract
This article focuses on the social impact of educational sciences. It introduces a framework for studying the social impact of research and uses it to analyze the social impact of the work of a research group studying learning difficulties at the University of Jyväskylä, Finland. The framework suggests that the social impact of research can be understood in terms of the context of impact. This context is composed of four interacting dimensions: epistemic, artefactual, social-institutional, and spatial-geographical dimensions. In addition, the paper suggests that the understanding of the phenomena to be studied and mediating artefacts based on this understanding play a key role in the expansion of the social impact in the educational sciences. The article provides a means of analyzing the narratives of longer-term impact of research and suggests that even in education—a classical area of advancing public good—the distribution of mediating artefacts is increasingly likely to be realized through markets.
Cognitive reserve-mediated neural modulation of emotional control and regulation in people with late-life depression
Authors: Huang Chih-Mao , Fan Yang-Teng , Lee Shwu-Hua , Liu Ho-Ling , Chen Yao-Liang , Lin Chemin , Lee Tatia M C 
Published: July 2019

AbstractLate-life depression (LLD) is an affective disorder that is highly prevalent among older people. Cognitive reserve (CR) refers to an active process that facilitates the flexibility and efficiency of the neural networks to compensate for impairments that emerge in consequence of brain pathology. The current functional magnetic resonance imaging study investigated whether and how CR affects emotional regulation, level of depression severity and neural activity associated with affective control during emotional Stroop (eStroop) task. Altogether, 90 older people participated in this study, 50 of whom suffered from LLD. We used years of education and verbal fluency capacity as proxies for CR. Clinical participants with relatively higher CR presented with milder degrees of depression, better eStroop performance and stronger neural activity in the middle frontal gyrus (MFG) involved with exercising affective control. Results of the mediation analysis indicated that both education and verbal fluency significantly mediated the association between the depression severity and MEG activity. These results suggest a negative association between CR and age-related clinical symptoms of emotional dysregulation. Our neurobehavioral findings provide supportive evidence that CR implies efficiency of top-down emotional regulation and operates as a protective factor against emotional and cognitive vulnerability in the aging brain.
The Extension of Particularized Trust to Generalized and Out-Group Trust: The Constraining Role of Collectivism
Authors: Glanville Jennifer L , Shi Qianyi 
Published: July 2019

AbstractA central line of inquiry into the sources of generalized trust concerns how particularized trust (trust in known others) extends to generalized trust (default expectations about the trustworthiness of people in general). While we know that there is considerable cross-national variability in the strength of the relationship between particularized and generalized trust, little is known about the contextual factors that shape the degree to which particularized trust spills over to more diffuse forms of trust. We argue that collectivism plays a key role in the extension of trust. The nature of social interactions in low collectivism societies is conducive to the trust and distrust built up within social interactions extending to generalized and out-group trust, whereas high levels of collectivism should dampen the ability of particularized trust to extend. Analyzing data on over 52,000 respondents from 39 countries from Waves 5 and 6 of the World Values Survey, we find that the predicted effects particularized trust on generalized and out-group trust are substantially smaller in more collectivist countries. Our results also suggest that collectivism and individualism matter more for generalized and out-group trust for individuals who have higher levels of particularized trust.
Unmasking Racism: Students of Color and Expressions of Racism in Online Spaces
Authors: Eschmann Rob 
Published: July 2019

AbstractExpressions of racism in the post-Civil Rights Era are expected to be more covert than overt and more unconscious than conscious. But some internet-based communication takes place in technological contexts that are not bound by the same norms as face-to-face interactions, and can structure more explicit presentations of racist ideologies. I explore the changing expressions of racism in online spaces and their effects on students of color using in-depth interviews with 27 undergraduate students of color and their reactions to and interpretations of an online, anonymous student forum. I argue that covert racism is unmasked in online environments, and that exposure to unmasked racial ideologies can challenge students’ racial worldviews, adaptive coping responses to racism, relationships to White students and institutions, and dominant racial narratives.