julilili42/papers huggingface dataset:
Detection of very-high-energy γ-ray emission from the colliding wind binary η Car with H.E.S.S.
2020-02-08

Aims. Colliding wind binary systems have long been suspected to be high-energy (HE; 100 MeV &lt; E &lt; 100 GeV) γ -ray emitters. η Car is the most prominent member of this object class and is confirmed to emit phase-locked HE γ rays from hundreds of MeV to ~100 GeV energies. This work aims to search for and characterise the very-high-energy (VHE; E &gt;100 GeV) γ -ray emission from η Car around the last periastron passage in 2014 with the ground-based High Energy Stereoscopic System (H.E.S.S.). Methods. The region around η Car was observed with H.E.S.S. between orbital phase p = 0.78−1.10, with a closer sampling at p ≈ 0.95 and p ≈ 1.10 (assuming a period of 2023 days). Optimised hardware settings as well as adjustments to the data reduction, reconstruction, and signal selection were needed to suppress and take into account the strong, extended, and inhomogeneous night sky background (NSB) in the η Car field of view. Tailored run-wise Monte-Carlo simulations (RWS) were required to accurately treat the additional noise from NSB photons in the instrument response functions. Results. H.E.S.S. detected VHE γ -ray emission from the direction of η Car shortly before and after the minimum in the X-ray light-curve close to periastron. Using the point spread function provided by RWS, the reconstructed signal is point-like and the spectrum is best described by a power law. The overall flux and spectral index in VHE γ rays agree within statistical and systematic errors before and after periastron. The γ -ray spectrum extends up to at least ~400 GeV. This implies a maximum magnetic field in a leptonic scenario in the emission region of 0.5 Gauss. No indication for phase-locked flux variations is detected in the H.E.S.S. data.
Perception of Urban Green Areas Associated with Sociodemographic Affiliation, Structural Elements, and Acceptance Stripes
2020-02-08

The extensification (opposite of intensification) of urban public green spaces offers great potential for conservation. One major issue for the long-term success of such a measure is, however, its acceptance by the urban population. This contribution presents the results of an image-based online questionnaire that we set to elucidate the role of sociodemographic affiliations regarding the perception of urban green areas. We also asked whether acceptability can be increased by the presence of additional structural elements (sculptures, benches) and “acceptance stripes”, i.e., stripes regularly mowed only at the margins of a natural green space. Regarding structural elements, 40- to 60-year-olds consistently rejected intensely maintained lawns and perceived a lawn as positive only in combination with a sculpture. A regularly mowed acceptance stripe resulted in a positive perception of natural meadows by people with an affinity for city life, classified based on their actual place of residence and/or their social dimension including aspects such as sense of place, familiarity, profession, and interests. Thus, decision-making processes of policy makers must be evaluated together with the urban population and should be assessed multidimensionally, i.e., by considering various criteria (e.g., ecological, social, and aesthetic aspects) in order to meet the requirements of residents and achieve an increase in biodiversity.
The giant outburst of 4U 0115+634 in 2011 with Suzaku and RXTE Minimizing cyclotron line biases
2020-02-08

We present an analysis of X-ray spectra of the high mass X-ray binary 4U 0115+634 as observed with Suzaku and RXTE in 2011 July, during the fading phase of a giant X-ray outburst. We used a continuum model consisting of an absorbed cutoff power-law and an ad-hoc Gaussian emission feature centered around 8.5 keV, which we discuss to be due to cyclotron emission. Our results are consistent with a fundamental cyclotron absorption line centered at ∼10.2 keV for all observed flux ranges. At the same time we rule out significant influence of the 8.5 kev Gaussian on the CRSF parameters, which are not consistent with the cyclotron line energies and depths of previously reported flux-dependent descriptions. We also show that some continuum models can lead to artificial line-like residuals in the analyzed spectra, which are then misinterpreted as unphysically strong cyclotron lines. Specifically, our results do not support the existence of a previously claimed additional cyclotron feature at ∼15 keV. Apart from these features, we find for the first time evidence for a He-like Fe XXV emission line at ∼6.7 keV and weak H-like Fe XXVI emission close to ∼7.0 keV.
Retinal oedema in central retinal artery occlusion develops as a function of time
2020-02-10

Abstract Purpose Time is the key criterion in the management of non‐arteritic central retinal artery occlusion (NA‐CRAO). However, the precise onset of vision loss is often difficult to determine. This study aimed to evaluate the temporal changes of retinal thickness in acute NA‐CRAO and the potential of this parameter to be used as a surrogate marker to estimate the onset of retinal ischaemia. Methods Optical coherence tomography was used to continuously assess retinal thickness and oedema progression rate in six porcine eyes. Additionally, a retrospective analysis of 12 patients with acute NA‐CRAO was performed to determine association strength and progression rate between retinal thickness and onset of ischaemia. All Optical coherence tomography (OCT) scans (pigs and NA‐CRAO patients) were performed within an ischaemic time frame of up to 9 hr. Results Retinal oedema progression rate in pigs was 25.32 μm/hr [CI 95%: 24.24–26.40 μm/hr]. Retrospective analysis of the patients revealed a strong correlation between retinal oedema and duration of ischaemia (Spearman's rho = 0.77, p = 0.004) with an estimated progression rate of 10.02 μm/hr [CI 95%: 3.30–16.74 μm/hr]. Conclusion Retinal thickness increases with oedema formation, and ischaemia onset is strongly correlated with this structural biomarker in both, pigs and NA‐CRAO patients. Prospective clinical trials will have to determine the clinical feasibility of retinal thickness measurements as a biomarker to support clinical management of NA‐CRAO.
Evolution of the Accretion Disk–Corona during the Bright Hard-to-soft State Transition: A Reflection Spectroscopic Study with GX 339–4
2020-02-10

Abstract We present the analysis of several observations of the black hole binary GX 339–4 during its bright intermediate states from two different outbursts (2002 and 2004), as observed by the RXTE /Proportional Counter Array. We perform a consistent study of its reflection spectrum by employing the relxill family of relativistic reflection models to probe the evolutionary properties of the accretion disk including the inner disk radius ( R in ), ionization parameter ( ξ ), temperatures of the inner disk ( T in ), corona ( kT e ), and its optical depth ( τ ). Our analysis indicates that the disk inner edge approaches the innermost stable circular orbit during the early onset of the bright hard state, and that the truncation radius of the disk remains low (&lt;9 R g ) throughout the transition from hard to soft state. This suggests that the changes observed in the accretion disk properties during the state transition are driven by variation in accretion rate, and not necessarily due to changes in the inner disk’s radius. We compare the aforementioned disk properties in two different outbursts with state transitions occurring at dissimilar luminosities and find identical evolutionary trends in the disk properties, with differences only seen in the corona’s kT e and τ . We also perform an analysis by employing a self-consistent Comptonized accretion disk model accounting for the scatter of disk photons by the corona, and measure the low inner disk truncation radius across the bright intermediate states, using the temperature-dependent values of the spectral hardening factor, thereby independently confirming our results from the reflection analysis.
Finite element error analysis of wave equations with dynamic boundary conditions:L2 estimates
2020-02-10

Abstract norm error estimates of semi- and full discretizations of wave equations with dynamic boundary conditions, using bulk–surface finite elements and Runge–Kutta methods, are studied. The analysis rests on an abstract formulation and error estimates, via energy techniques, within this abstract setting. Four prototypical linear wave equations with dynamic boundary conditions are analysed, which fit into the abstract framework. For problems with velocity terms or with acoustic boundary conditions we prove surprising results: for such problems the spatial convergence order is shown to be less than 2. These can also be observed in the presented numerical experiments.
A Field Evidence Model: How to Predict Transport in a Heterogeneous Aquifers at Low Investigation Level?
2020-02-10

Abstract. Aquifer heterogeneity in combination with data scarcity is a major challenge for reliable solute transport prediction. Velocity fluctuations cause non-regular plume shapes with potentially long tailing and/or fast traveling mass fractions. High monitoring cost and presumably missing simple concepts have limited the incorporation of heterogeneity to many field transport models up to now. We present a hierarchical aquifer model which combines large-scale deterministic structures and simple stochastic approaches. Such a heterogeneous conductivity can easily be integrated into a numerical models. Depending on the modeling aim, the required structural complexity can be adapted. The same holds for the amount of available field data. The conductivity model is constructed step-wise following field evidence from observations; though relying on as minimal data as possible. Starting point are deterministic blocks, derived from head profiles and pumping tests. Then, sub-scale heterogeneity in form of random binary inclusions are introduced to each block. Structural parameters can be determined e.g. from flowmeter measurements. As proof of concept, we implemented a predictive transport model for the heterogeneous MADE site. The proposed hierarchical aquifer structure reproduces the plume development of the MADE-1 transport experiment without calibration. Thus, classical ADE models are able to describe highly skewed tracer plumes by incorporating deterministic contrasts and effects of connectivity in a stochastic way even without using uni-modal heterogeneity models with high variances. The reliance of the conceptual model on few observations makes it appealing for a goal-oriented site specific transport analysis of less well investigated heterogeneous sites.
Microbial Weathering of Minerals and Rocks in Natural Environments
2020-02-10

Microbes are active agents of environmental change. From the depths of the Earth's crust to the heights of the upper atmosphere, microorganisms alter the physicochemical conditions surrounding them. Their activity provides important ecosystem services to the wider biosphere, making essential elements such as carbon, sulfur, phosphorus, and iron available for higher organisms. One such environmental interaction is the weathering of minerals and rocks by microbial communities, a key process that underpins soil formation and global biogeochemical cycles. By facilitating mineral dissolution and rock degradation, microbes enhance the release of elements from their geological reservoirs and perform significant elemental transformations. Under what conditions microbes perform these activities and to what extent they impact their surrounding environment, are key topics in geobiology. In this chapter, various aspects of microbial mineral and rock weathering will be explored. Key concepts and terminology will be introduced, followed by an overview of the mechanisms used by microorganisms to perform weathering activity. Sections covering the methodological approaches used by researchers to study microbial rock weathering processes, including detecting the traces or "biosignatures" such microbial activity leaves behind on geological materials, will be provided. The effect of microbial rock weathering on the wider microbial ecosystem, including the endurance and functional capacity of microbial communities, is also explored. Finally, this chapter will discuss the emerging field of microbial biogeomorphology, the study of how biological activity at the micron scale can impact the environment at meter to kilometer scales, contributing to the processes that shape Earth's landscapes.
Conditional freedom : free soil and fugitive slaves from the US South to Mexico's Northeast, 1803-1861
2020-02-10

While the literature on slave flight in nineteenth-century North America has commonly focused on fugitive slaves escaping to the northern states and Canada through the “Underground Railroad”, Conditional Freedom aims to provide new insights into the evolving social and political geography of freedom and slavery in nineteenth-century North America, particularly by exploring the development of southern routes of escape from slavery in the US South and the experiences of self-emancipated slaves in the US-Mexican borderlands. First, Conditional Freedom provides a social history of enslaved freedom-seekers. Second, it also provides a political history of the contest between Mexican free soil and the spread of slavery west of the Mississippi river valley between 1803 and 1861. Its main question is: what was the nature of slave flight in the Mexican borderlands, and how and why did Mexico develop into a site of “conditional freedom” for slave refugees from the American South? In order to reconstruct the entangled stories of slave refugees and free soil in the US-Mexico borderlands, this study draws mostly upon municipal, county and state archives, military and judicial records, diplomatic and personal correspondence, newspaper articles, “runaway slave” advertisements, petitions, memoirs and travel accounts.
Short stem hip arthroplasty provides a more physiological load transfer: a comparative finite element analysis study
2020-02-10

Abstract Background Short stem total hip arthroplasty (SHA) preserves femoral bone stock and is supposed to provide a more natural load transfer compared to standard stem total hip arthroplasty (THA). As comparative biomechanical reference data are rare we used a finite element analysis (FEA) approach to compare cortical load transfer after implantations of a cementless short and standard stem in native biomechanical femora. Methods The subject specific finite element models of biomechanical femora, one native and two with implanted SHA (Metha, B.Braun Aesculap) and standard THA (CLS, Zimmer-Biomet), were generated from computed tomography datasets. The loading configuration was performed with an axial force of 1400 N. Von Mises stress was used to investigate the change of cortical stress distribution. Results Compared to the native femur, a considerable reduction of cortical stress was recorded after implantation of SHA and standard THA. The SHA showed less reduction proximally with a significant higher metaphyseal cortical stress compared to standard THA. Moreover, the highest peak stresses were observed metaphyseal for the SHA stem while for the standard THA high stress pattern was observed more distally. Conclusion Both, short and standard THA, cause unloading of the proximal femur. However, SHA features a clearly favorable pattern in terms of a lower reduction proximally and improved metaphyseal loading, while standard THA shows a higher proximal unloading and more distal load transfer. These load pattern implicate a reduced stress shielding proximally for SHA and might be able to translate in a better bone preservation.
Spinning and excited black holes in Einstein-scalar-Gauss–Bonnet theory
2020-02-11

We construct rotating black holes in Einstein-scalar-Gauss-Bonnet theory with\\na quadratic coupling function. We map the domain of existence of the rotating\\nfundamental solutions, we construct radially excited rotating black holes\\n(including their existence lines), and we show that there are angularly excited\\nrotating black holes. The bifurcation points of the radially and angularly\\nexcited solutions branching out of the Schwarzschild solution follow a regular\\npattern.\\n
Neuropsychological and neurophysiological aspects of brain‐computer‐interface (BCI) control in paralysis
2020-02-11

Abstract Brain‐computer interfaces (BCIs) aim to help paralysed patients to interact with their environment by controlling external devices using brain activity, thereby bypassing the dysfunctional motor system. Some neuronal disorders, such as amyotrophic lateral sclerosis (ALS), severely impair the communication capacity of patients. Several invasive and non‐invasive brain‐computer interfaces (BCIs), most notably using electroencephalography (EEG), have been developed to provide a means of communication to paralysed patients. However, except for a few reports, all available BCI literature for the paralysed (mostly ALS patients) describes patients with intact eye movement control, i.e. patients in a locked‐in state (LIS) but not a completely locked‐in state (CLIS). In this article we will discuss: (1) the fundamental neuropsychological learning factors and neurophysiological factors determining BCI performance in clinical applications; (2) the difference between LIS and CLIS; (3) recent development in BCIs for communication with patients in the completely locked‐in state; (4) the effect of BCI‐based communication on emotional well‐being and quality of life; and (5) the outlook and the methodology needed to provide a means of communication for patients who have none. Thus, we present an overview of available studies and recent results and try to anticipate future developments which may open new doors for BCI communication with the completely paralysed. image
Financial literacy and entrepreneurial risk aversion
2020-02-11

We explore the interaction effects of financial literacy and risk aversion on becoming an entrepreneur. We use two independent datasets to provide evidence that the difference in risk aversion between entrepreneurs and wage earners is conditional on their financial literacy. First, we use the De Nederlandsche Bank's Household Survey and find lower risk aversion only for entrepreneurs with lower financial literacy. The difference disappears for entrepreneurs with higher financial literacy. Second, we show that the results are robust in a fully incentivized field experiment with high-tech startups from three European countries. The results reveal a potential channel of how financial literacy can promote entrepreneurship.
Surgical necrotizing enterocolitis but not spontaneous intestinal perforation is associated with adverse neurological outcome at school age
2020-02-11

Abstract Gastrointestinal complications during the neonatal period, i.e. necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP), are associated with adverse short-term outcome in very-low-birthweight infants (VLBWI, &lt;1500 g birth weight). However, little is known about the neurological outcome of survivors at school age. We analysed data of 2241 infants followed-up at the age of 6 years. To determine the effect of NEC and SIP on cognitive outcome in consideration of other important confounding factors, we used multivariable logistic regression models. In addition, infants with surgical diagnosis of NEC (n = 43) or SIP (n = 41) were compared to NEC (n = 43) or SIP (n = 41) negative controls using Mahalanobis distance matching. Infants with a history for NEC had a three times increased risk (RR 3.0 [1.8–4.2], p &lt; 0.001) to develop IQ scores &lt;85 while history of surgical SIP did not increase the relative risk for lower IQs at school age (RR 1.0 [0.4–2.1], p = 1.000). In a matched-cohort analysis, we confirmed that infants with surgical NEC had lower mean IQ results than unaffected controls (±SD) (85±17 vs. 94±14, p = 0.023) while no differences were found for history of SIP. Our results reflect that the different aetiology and inflammatory extent of NEC and SIP may lead to disparate neurodevelopment trajectories. Hence, our data suggest a potential role of early gut-brain axis distortion in infants with NEC which needs to be further explored.
Anti-austerity between militant materialism and real democracy: exploring pragmatic prefigurativism
2020-02-11

The anti-austerity movement that emerged in the wake of the 2008 global economic crisis and 2010 Eurozone crisis, and which forms part of the ‘age of austerity’ that came after those crises, was underpinned by a set of ideas and practices that we refer to here as ‘pragmatic prefigurativism’. Whilst the anti-austerity movements typically rejected formal ideologies such as Marxism and anarchism, nevertheless pragmatic prefigurativism can be understood as a ‘left convergence’ of sorts. The paper explores the features of this pragmatic prefigurativism, comparing the anti-austerity movements in the UK and Spain. In particular, we note the role of unresponsive institutions of democracy in prompting the move towards pragmatic prefigurativism, the adoption of techniques of direct democracy and direct action as the means through which to express a voice and to refuse austerity, and the pragmatic nature of the subsequent (re)turn to political institutions when this became a possibility.
The Zandmotor data do not resolve the question whether Middle Paleolithic birch tar making was complex or not
2020-02-11

Niekus et al. (1) present a find of Neanderthal birch tar from Zandmotor (The Netherlands), concluding that a cognitively complex underground production method was used. However, Schmidt et al. (2) recently showed that birch tar production can be simple [burning bark near stones: the condensation method (2)]. Two arguments are used by Niekus et al. (1) to claim that the Zandmotor tar was produced with a complex method: The efficiency of simpler techniques was too low, and their tar’s composition indicates a complex technique. As we will argue, these arguments are invalid. Producing 0.6 g of tar took 3 h with the condensation method (2), leading Niekus et al. ... [↵][1]1To whom correspondence may be addressed. Email: patrick.schmidt{at}uni-tuebingen.de. [1]: #xref-corresp-1-1
Voltage-gated calcium channel subunit α2δ-3 shapes light responses of mouse retinal ganglion cells mainly in low and moderate light levels
2020-02-11

Abstract Little is known about the function of the auxiliary α 2 δ subunits of voltage-gated calcium channels in the retina. We investigated the role of α 2 δ-3 ( Cacna2d3 ) using a mouse in which α 2 δ-3 was knocked out by LacZ insertion. Behavior experiments indicated a normal optokinetic reflex in α 2 δ-3 knockout animals. Strong expression of α 2 δ-3 could be localized to horizontal cells using the LacZ-reporter, but horizontal cell mosaic and currents carried by horizontal cell voltage-gated calcium channels were unchanged by the α 2 δ-3 knockout. In vivo electroretinography revealed unaffected photoreceptor activity and signal transmission to depolarizing bipolar cells. We recorded visual responses of retinal ganglion cells with multi-electrode arrays in scotopic to photopic luminance levels and found subtle changes in α 2 δ-3 knockout retinas. Spontaneous activity in OFF ganglion cells was elevated in all luminance levels. Differential response strength to high- and low-contrast Gaussian white noise was compressed in ON ganglion cells during mesopic ambient luminance and in OFF ganglion cells during scotopic and mesopic ambient luminances. In a subset of ON ganglion cells, we found a sharp increase in baseline spiking after the presentation of drifting gratings in scotopic luminance. This increase happened after gratings of different spatial properties in knockout compared to wild type retinas. In a subset of ON ganglion cells of the α 2 δ-3 knockout, we found altered delays in rebound-like spiking to full-field contrast steps in scotopic luminance. In conclusion, α 2 δ-3 seems to participate in shaping visual responses mostly within brightness regimes when rods or both rods and cones are active.