julilili42/papers huggingface dataset:
In-depth study of long-term variability in the X-ray emission of the Be/X-ray binary system AX J0049.4−7323
2018-02-24

AX J0049.4−7323 is a Be/X-ray binary in the Small Magellanic Cloud hosting a ~750 s pulsar which has been observed over the last ~17 years by several X-ray telescopes. Despite numerous observations, little is known about its X-ray behaviour. Therefore, we coherently analysed archival Swift , Chandra , XMM-Newton , RXTE, and INTEGRAL data, and we compared them with already published ASCA data, to study its X-ray long-term spectral and flux variability. AX J0049.4−7323 shows a high X-ray variability, spanning more than three orders of magnitudes, from L ≈ 1.6 × 10 37 erg s −1 (0.3−8 keV, d = 62 kpc) down to L ≈ 8 × 10 33 erg s −1 . RXTE, Chandra , Swift , and ASCA observed, in addition to the expected enhancement of X-ray luminosity at periastron, flux variations by a factor of ~270 with peak luminosities of ≈2.1 × 10 36 erg s −1 far from periastron. These properties are difficult to reconcile with the typical long-term variability of Be/XRBs, traditionally interpreted in terms of type I and type II outbursts. The study of AX J0049.4−7323 is complemented with a spectral analysis of Swift , Chandra , and XMM-Newton data which showed a softening trend when the emission becomes fainter, and an analysis of optical/UV data collected by the UVOT telescope on board Swift . In addition, we measured a secular spin-up rate of Ṗ = (−3.00 ± 0.12) × 10 −3 s day −1 , which suggests that the pulsar has not yet achieved its equilibrium period. Assuming spherical accretion, we estimated an upper limit for the magnetic field strength of the pulsar of ≈3 × 10 12 G.
Transitory microbial habitat in the hyperarid Atacama Desert
2018-02-26

Significance It has remained an unresolved question whether microorganisms recovered from the most arid environments on Earth are thriving under such extreme conditions or are just dead or dying vestiges of viable cells fortuitously deposited by atmospheric processes. Based on multiple lines of evidence, we show that indigenous microbial communities are present and temporally active even in the hyperarid soils of the Atacama Desert (Chile). Following extremely rare precipitation events in the driest parts of this desert, where rainfall often occurs only once per decade, we were able to detect episodic incidences of biological activity. Our findings expand the range of hyperarid environments temporarily habitable for terrestrial life, which by extension also applies to other planetary bodies like Mars.
Sleep Does Not Promote Solving Classical Insight Problems and Magic Tricks
2018-02-26

During creative problem solving, initial solution attempts often fail because of self-imposed constraints that prevent us from <i>thinking out of the box</i>. In order to solve a problem successfully, the problem representation has to be restructured by combining elements of available knowledge in novel and creative ways. It has been suggested that sleep supports the reorganization of memory representations, ultimately aiding problem solving. In this study, we systematically tested the effect of sleep and time on problem solving, using classical insight tasks and magic tricks. Solving these tasks explicitly requires a restructuring of the problem representation and may be accompanied by a subjective feeling of insight. In two sessions, 77 participants had to solve classical insight problems and magic tricks. The two sessions either occurred consecutively or were spaced 3 h apart, with the time in between spent either sleeping or awake. We found that sleep affected neither general solution rates nor the number of solutions accompanied by sudden subjective insight. Our study thus adds to accumulating evidence that sleep does not provide an environment that facilitates the qualitative restructuring of memory representations and enables problem solving.
Eye-Hand Behavior in Human-Robot Shared Manipulation
2018-02-26

Shared autonomy systems enhance people's abilities to perform activities of daily living using robotic manipulators. Recent systems succeed by first identifying their operators' intentions, typically by analyzing the user's joystick input. To enhance this recognition, it is useful to characterize people's behavior while performing such a task. Furthermore, eye gaze is a rich source of information for understanding operator intention. The goal of this paper is to provide novel insights into the dynamics of control behavior and eye gaze in human-robot shared manipulation tasks. To achieve this goal, we conduct a data collection study that uses an eye tracker to record eye gaze during a human-robot shared manipulation activity, both with and without shared autonomy assistance. We process the gaze signals from the study to extract gaze features like saccades, fixations, smooth pursuits, and scan paths. We analyze those features to identify novel patterns of gaze behaviors and highlight where these patterns are similar to and different from previous findings about eye gaze in human-only manipulation tasks. The work described in this paper lays a foundation for a model of natural human eye gaze in human-robot shared manipulation.
How well can ultracompact bodies imitate black hole ringdowns?
2018-02-26

The ongoing observations of merging black holes by the instruments of the\\nfledging gravitational wave astronomy has opened the way for testing the\\ngeneral relativistic Kerr black hole metric and, at the same time, for probing\\nthe existence of more speculative horizonless ultracompact objects. In this\\npaper we quantify the difference that these two classes of objects may exhibit\\nin the post-merger ringdown signal. By considering rotating systems in general\\nrelativity and assuming an eikonal limit and a third-order Hartle-Thorne slow\\nrotation approximation, we provide the first calculation of the early ringdown\\nfrequency and damping time as a function of the body's multipolar structure.\\nUsing the example of a gravastar, we show that the main ringdown signal may\\ndiffer as much as a few percent with respect to that of a Kerr black hole, a\\ndeviation that could be probed by near future Advanced LIGO/Virgo searches.\\n
Does evaluative conditioning depend on awareness? Evidence from a continuous flash suppression paradigm.
2018-02-26

The role of awareness in evaluative learning has been thoroughly investigated with a variety of theoretical and methodological approaches. We investigated evaluative conditioning (EC) without awareness with an approach that conceptually provides optimal conditions for unaware learning - the Continuous Flash Suppression paradigm (CFS). In CFS, a stimulus presented to one eye can be rendered invisible for a prolonged duration by presenting a high-contrast dynamic pattern to the other eye. The suppressed stimulus is nevertheless processed. First, Experiment 1 established EC effects in a pseudo-CFS setup without suppression. Experiment 2 then employed CFS to suppress conditioned stimuli (CSs) from awareness while the unconditioned stimuli (USs) were visible. While Experiment 1 and 2 used a between-participants manipulation of CS suppression, Experiments 3 and 4 both manipulated suppression within participants. We observed EC effects when CSs were not suppressed, but found no EC effects when the CS was suppressed from awareness. We relate our finding to previous research and discuss theoretical implications for EC. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Valence‐Tuned Lithium Titanate Nanopowder for High‐Rate Electrochemical Energy Storage
2018-02-26

Abstract In recent years, numerous studies have explored ways to overcome the low intrinsic electrical conductivity of lithium titanate (Li 4 Ti 5 O 12 , LTO) for energy storage with lithium‐ion batteries. These approaches almost exclusively considered element doping and elaborate LTO‐carbon nanocomposites, whereas simple adjustment of the defect concentration remains largely unexplored. In our study, we tune the Ti 3+ /Ti 4+ concentration of a commercial LTO nanopowder through oxygen vacancy formation during thermal annealing in hydrogen atmosphere. We investigate the impact of the treatment on material properties like energy band structure, electrical conductivity, crystallinity, phase distribution, surface chemistry, and particle morphology, and correlate these parameters to the electrochemical performance. At optimum treatment conditions, the intrinsic electrical conductivity can be greatly improved, while circumventing LTO phase transformations or amorphization. This enables the reduction of the carbon concentration to 5 mass%, while yielding a high electrode capacity of about 70 mAh/g (82 mAh/g based on active mass) at ultrahigh C‐rates of 100C. When combined with an activated carbon/lithium manganese oxide composite cathode, an excellent energy and power performance of 70 Wh/kg and 47 kW/kg were obtained (82 Wh/kg and 55 kW/kg based on active mass), while maintaining 83 % of its energy ratings after 5000 cycles at 10C (78 % after 15000 cycles at 100C).
Tunable Charge Transport in Hybrid Superlattices of Indium Tin Oxide Nanocrystals and Metal Phthalocyanines—Toward Sensing Applications
2018-02-26

Abstract Macroscopic superlattices of tin‐doped indium oxide (ITO) nanocrystals (NCs) are prepared by self‐assembly at the air/liquid interface followed by simultaneous ligand exchange with the organic semiconductors M‐4,4′,4′′,4′′′‐tetraaminophthalocyanine (M4APc, M = Cu, Co, Fe, Ni, Zn). Transport measurements, focusing on the effect of the metal center of the ligand, reveal a ligand‐dependent increase in electrical conductance by six to nine orders of magnitude, suggesting that M4APc provides efficient electronic coupling for neighboring ITO NCs. The resulting I–V characteristics as well as the temperature dependence (7–300 K) of the zero‐voltage conductance indicates that at low temperatures, transport across the arrays occurs via a sequence of inelastic cotunneling events, each involving ≈3 ITO NCs. At higher temperatures, a crossover to 3D Mott‐variable range hopping mechanism is observed. Finally, the vapor sensitivity of chemiresistors is investigated made from ITO NCs coupled via Cu‐ and Zn4APc by dosing the sensors with 4‐methyl‐2‐pentanone (4M2P), toluene, 1‐propanol, and water in the concentration range of 100–5000 ppm at 0% relative humidity. The nanocrystal superlattices respond with an increase in resistance to these analytes with the highest sensitivity to 4M2P.
Approaching The Double‐Nominal Construction In Mandarin Chinese Through The Semantic‐Cognitive Interaction
2018-02-26

Abstract The double‐nominal construction ( DNC ), also called ‘topic construction’, is a common occurrence in Chinese and other East Asian languages. It is characterized by two initial NP s which appear before the predicate verb. The construction has mostly been analyzed using the syntactic angle singly approach. The topic (the initial nominal phrase, abbreviated as NP 1) needs to syntactically establish some connection with the comment (the rest of the construction) but this has, unfortunately, not been the case due to numerous counterexamples. This construction is so complex that other factors have to be taken into account. This paper addresses the major concern about the problem of the two Initial NP s’ transposition in various DNC s, an area that does not appear to have previously been sufficiently explored. Compared with other languages, the transposition of two initial NP s in DNC is unique to Chinese. The transposition with two initial NP s in each type of DNC performs quite differently, so we should make finer classification for DNC reasonably. In order to propose reasonable classification of DNC , we need to clarify the relationship between NP 1 and the rest of the construction. Meanwhile, in order to tackle the problem of the two NP s’ transposition in a special type of DNC called dangling topic construction, we propose a more reasonable and precise interpretation of the relationship between topic and comment in this construction using the event‐based model and the event integration. This study shows how, depending on the syntactic‐semantic behavior of NP 1, Chinese DNC s can be classified into three types. Finally, based on the three types of DNC proposed, a semantic‐cognitive interaction helps to explain and resolve the problem of NP s’ transposition for each type. This study, therefore, provides a unified and more developed account of Chinese DNC . Consequently, a semantic‐cognitive approach is likely to shed more light on the notion of topic construction and help understand how Chinese native speakers comprehend its structure and construct the meaning.
A modified shark-fin test simulating the single-step/double-mix technique: A comparison of three groups of elastomers
2018-02-26

The shark-fin test was modified to convey the clinical application of a single-step/double-mix technique assessing the behavior of two viscosities applied at one point in time. A medium and light body polyether (PE), a medium and light body polyvinylsiloxane (PVS), and a medium as well as heavy and light body vinyl polyether silicone (PVXE) impression material were analyzed solely, and in a layered mixture of 1:1 and 3:1 at working times of 50, 80, and 120 s. The fin heights were measured with a digital ruler. The wettability was measured 50 and 80 s after mixing by drop shape analysis. The results showed a synergistic effect of the medium and light body PE. This was not observed in PVXE and PVS. Interestingly, PVXE showed an antagonistic flow behavior in 3:1 mixture with medium body. PVXE was more hydrophilic than PE and PVS. Future rheological studies should clarify the detected flow effects.
A Signature of Passivity? An Explorative Study of the N3 Event-Related Potential Component in Passive Oddball Tasks
2018-02-26

Abstract Background Many passive oddball experiments show a sharp negative deflection N3 after P3b, peaking between 400 and 500 ms, but this wave has never been analyzed properly. We conducted five passive oddball experiments, in which the number of deviants (i.e., one or two), their alleged meaning, and their distinctiveness varied. Results Mastoid- or common-referenced waveforms showed a fronto-central N3 in all experiments. The data were CSD (Current Source Density) transformed and underwent a Principal Component Analysis (PCA). The PCA revealed N3 containing two subcomponents with very stable peak latencies of about 415 and 455 ms, respectively. Both topography of the subcomponents and their variation with experimental conditions were very similar, indicating a midfrontal sink and a posterior temporal source. An analysis of P3a and P3b components replicated previously known effects. Conclusions We discuss the similarities and differences between the passive N3 and other components including the MMN, N1, late positive Slow Wave, and reorienting negativity. We also make general hypotheses about a possible functional meaning of N3; on this basis, specific hypotheses are formulated and further experiments are suggested to test these hypotheses.
Robust singlet fission in pentacene thin films with tuned charge transfer interactions
2018-02-27

Abstract Singlet fission, the spin-allowed photophysical process converting an excited singlet state into two triplet states, has attracted significant attention for device applications. Research so far has focused mainly on the understanding of singlet fission in pure materials, yet blends offer the promise of a controlled tuning of intermolecular interactions, impacting singlet fission efficiencies. Here we report a study of singlet fission in mixtures of pentacene with weakly interacting spacer molecules. Comparison of experimentally determined stationary optical properties and theoretical calculations indicates a reduction of charge-transfer interactions between pentacene molecules with increasing spacer molecule fraction. Theory predicts that the reduced interactions slow down singlet fission in these blends, but surprisingly we find that singlet fission occurs on a timescale comparable to that in pure crystalline pentacene. We explain the observed robustness of singlet fission in such mixed films by a mechanism of exciton diffusion to hot spots with closer intermolecular spacings.
Effects of resveratrol supplementation on liver fat content in overweight and insulin‐resistant subjects: A randomized, double‐blind, placebo‐controlled clinical trial
2018-02-27

We performed the largest randomized, placebo‐controlled clinical trial to date (N = 112, 12‐week intervention) to investigate the effects and safety of resveratrol supplementation on liver fat content and cardiometabolic risk parameters in overweight and obese and insulin‐resistant subjects. At baseline the variability in liver fat content was very large, ranging from 0.09% to 37.55% (median, 7.12%; interquartile range, 3.85%‐12.94%). Mean (SD) liver fat content was 9.22 (6.85) % in the placebo group and 9.91 (7.76) % in the resveratrol group. During the study liver fat content decreased in the placebo group (−0.7%) but not in the resveratrol group (−0.03%) (differences between groups: P = .018 for the intention‐to‐treat [ITT] population; N = 54, resveratrol, N = 54, placebo and P = .0077 for the per protocol [PP] population). No effects of resveratrol supplementation on cardiometabolic risk parameters were observed. Resveratrol supplementation was well tolerated and safe. In conclusion, these data suggest that resveratrol supplementation is safe and that it does not considerably impact liver fat content or cardiometabolic risk parameters in humans.
Growth and Population Dynamics of the Anaerobic Fe(II)-Oxidizing and Nitrate-Reducing Enrichment Culture KS
2018-02-27

ABSTRACT Most isolated nitrate-reducing Fe(II)-oxidizing microorganisms are mixotrophic, meaning that Fe(II) is chemically oxidized by nitrite that forms during heterotrophic denitrification, and it is debated to which extent Fe(II) is enzymatically oxidized. One exception is the chemolithoautotrophic enrichment culture KS, a consortium consisting of a dominant Fe(II) oxidizer, Gallionellaceae sp., and less abundant heterotrophic strains (e.g., Bradyrhizobium sp., Nocardioides sp.). Currently, this is the only nitrate-reducing Fe(II)-oxidizing culture for which autotrophic growth has been demonstrated convincingly for many transfers over more than 2 decades. We used 16S rRNA gene amplicon sequencing and physiological growth experiments to analyze the community composition and dynamics of culture KS with various electron donors and acceptors. Under autotrophic conditions, an operational taxonomic unit (OTU) related to known microaerophilic Fe(II) oxidizers within the family Gallionellaceae dominated culture KS. With acetate as an electron donor, most 16S rRNA gene sequences were affiliated with Bradyrhizobium sp. Gallionellaceae sp. not only was able to oxidize Fe(II) under autotrophic and mixotrophic conditions but also survived over several transfers of the culture on only acetate, although it then lost the ability to oxidize Fe(II). Bradyrhizobium spp. became and remained dominant when culture KS was cultivated for only one transfer under heterotrophic conditions, even when conditions were reverted back to autotrophic in the next transfer. This study showed a dynamic microbial community in culture KS that responded to changing substrate conditions, opening up questions regarding carbon cross-feeding, metabolic flexibility of the individual strains in KS, and the mechanism of Fe(II) oxidation by a microaerophile in the absence of O 2 . IMPORTANCE Nitrate-reducing Fe(II)-oxidizing microorganisms are present in aquifers, soils, and marine and freshwater sediments. Most nitrate-reducing Fe(II) oxidizers known are mixotrophic, meaning that they need organic carbon to continuously oxidize Fe(II) and grow. In these microbes, Fe(II) was suggested to be chemically oxidized by nitrite that forms during heterotrophic denitrification, and it remains unclear whether or to what extent Fe(II) is enzymatically oxidized. In contrast, the enrichment culture KS was shown to oxidize Fe(II) autotrophically coupled to nitrate reduction. This culture contains the designated Fe(II) oxidizer Gallionellaceae sp. and several heterotrophic strains (e.g., Bradyrhizobium sp.). We showed that culture KS is able to metabolize Fe(II) and a variety of organic substrates and is able to adapt to dynamic environmental conditions. When the community composition changed and Bradyrhizobium became the dominant community member, Fe(II) was still oxidized by Gallionellaceae sp., even when culture KS was cultivated with acetate/nitrate [Fe(II) free] before being switched back to Fe(II)/nitrate.
Surgical treatment of hidradenitis suppurativa: an analysis of postoperative outcome, cosmetic results and quality of life in 255 patients
2018-02-27

Abstract Background Hidradenitis suppurativa ( HS ) is a chronic inflammatory skin disease with increasing incidence. Severe disease stages are seen as a therapeutic challenge and pose the threat of significant restrictions on patients' life quality. Objectives We evaluated postoperative outcome after wide local excision for HS as well as postoperative course, cosmetic results, disease recurrence and quality of life. Methods All patients receiving radical surgical treatment for HS (Hurley III ) between 2006 and 2015 were identified and received a letter‐based survey. They were asked about postoperative course, cosmetic results, recurrence and life quality. Results Two hundred and fifty‐five patients (103 men, 152 women) answered the questionnaire. Ninety‐five percentage of patients reported disease‐specific restrictions on everyday life. Seventy‐five percentage of patients did not experience any postoperative adverse events; however, postoperative pain with need for analgesics was reported in 38%. The majority of patients (80%) were very satisfied or satisfied after surgery, and 85% of patients would recommend surgery to other affected persons. Limitations The retrospective design of the study was a limitation. Conclusions The well‐known negative psychological and social effects are a relevant part of HS and emphasize the importance of immediate therapy. As long‐lasting local disease‐control can be achieved, surgery should be considered as first‐line therapy.
Protoaurignacian Core Reduction Procedures: Blade and Bladelet Technologies at Fumane Cave
2018-02-27

The Protoaurignacian is one of the European techno-complexes that marks the beginning of the Upper Paleolithic. During this time bladelet implements, frequently intended to be hafted in composite tools, become the primary goal of lithic production. The growing number of technological investigations carried out on several assemblages has revealed that, in most cases, bladelets are not the result of the reduction of blade cores. However, the detailed procedures involved in the production of blades and bladelets have rarely been reconstructed. Here we report on diacritic investigations of early stage and exhausted cores from the Protoaurignacian layers of Fumane Cave in northeastern Italy. We show that core reduction is influenced by two distinct operational concepts that relate to the manufacture of different predetermined products. The first is characterized by a linear and consecutive knapping progression that aims to obtain blades and, to a minor extent, bladelets with sub-parallel edges. The second is characterized instead by an alternated knapping progression that is exclusively used to produce slender bladelets with a convergent shape. We also show that carinated cores do not significantly differ, technologically, from semicircumferential bladelet cores. We conclude by suggesting that there existed strong technological traditions shared between hunter-gatherers across the geographical extent of the Protoaurignacian.