LLukas22/scidocs huggingface dataset:
Modelling feedback from stars and black holes in galaxy mergers

We describe techniques for incorporating feedback from star formation and black hole accretion into simulations of isolated and merging galaxies. At present, the details of these processes cannot be resolved in simulations on galactic scales. Our basic approach therefore involves forming coarse-grained representations of the properties of the interstellar medium and black hole accretion starting from basic physical assumptions, so that the impact of these effects can be included on resolved scales. We illustrate our method using a multiphase description of star-forming gas. Feedback from star formation pressurises highly overdense gas, altering its effective equation of state. We show that this allows the construction of stable galaxy models with much larger gas fractions than possible in earlier numerical work. We extend the model by including a treatment of gas accretion onto central supermassive black holes in galaxies. Assuming thermal coupling of a small fraction of the bolometric luminosity of accreting black holes to the surrounding gas, we show how this feedback regulates the growth of black holes. In gas-rich mergers of galaxies, we observe a complex interplay between starbursts and central AGN activity when the tidal interaction triggers intense nuclear inflows of gas. Once an accreting supermassive black hole has grown to a critical size, feedback terminates its further growth, and expels gas from the central region in a powerful quasar-driven wind. Our simulation methodology is therefore able to address the coupled processes of gas dynamics, star formation, and black hole accretion during the formation of galaxies.
Exploring consumers' impulse buying behavior on social commerce platform: The role of parasocial interaction

Social commerce, a recent branch of e-commerce, has made the experience of consumers on social commerce platform (SCP) different from other contexts, as the consumers have social interactions with each other. Growing evidence also shows that consumers on these platforms are prone to impulse buying behavior owing to the social interactions. However, existing research on online impulse buying was limited when illustrating the behavior of consumers on SCPs as social relationship constructs were not included. New theoretical developments are needed in regard to fill the research gap. In this research, parasocial interaction (PSI) theory is introduced in this research to examine the influence of social relationship factors on the formation of impulse buying behavior. An empirical research has been conducted mpulse buying tendency on Mogujie (www.mogujie.com), one of the most popular image-sharing SCPs in China. Results indicate that PSI exerts an impact on impulse buying tendency, the social-relevant features of the SCP determine PSI, and perceived usefulness and PSI both significantly affect perceived enjoyment. In addition, consumers’ perceived enjoyment and impulse buying tendencies significantly affect their urge to buy impulsively. The implications, limitations, and discussions are provided. © 2015 Elsevier Ltd. All rights reserved.
STRATEGIC MARKETING PLANNING FOR MOBILE COMMERCE DIFFUSION AND CONSUMER ADOPTION

Recognizing the need for consumer behaviour research initiatives in business-to-consumer mobile commerce (m-commerce), this paper investigates consumer attitudes and behaviours in this fast evolving business landscape. An online consumer survey was conducted in Finland, Germany and Greece and a major classification between “mobile users” and “mobile shoppers” was attempted, using as a tool the consumer adoption and diffusion of innovation theory. Mobile shoppers are characterized as “innovators” and mobile users as “early adopters”. Significant differences between these groups from the same country and between different countries were observed regarding the importance they attach to security, ease of use interface, customer service, price, and comfort of device. Correspondingly, m-commerce service providers should design their strategic marketing planning by adapting their marketing mix elements to the specific requirements of each target market towards supporting m-commerce diffusion and consumer adoption in Europe.
Time Variation of Photons' Velocity in a "Dark" Universe

We discuss the non-minimal interaction between gravitation and electromagnetism. It is shown that the velocity of photons varies with time in a Universe with zero matter density, zero cosmological constant but is filled only with “dark matter”. One of the great physical problems of this century is to unify general relativity and quantum mechanics. Together they can explain a vast storehouse of physical knowledge, from the subatomic realm to the large-scale structure of the universe. However, attempts to unify quantum mechanics with general relativity have all met with frustration. Ideally, we could like to see gravitational interactions and GUT theory emerge from a higher unified field theory from geometrical or group theoretical arguments, rather than being put in by hand. The search for a more sophisticated theory embracing both guage theory and general relativity has led to a re-examination of the old theory of Kaluza-Klein. Kaluza [1] originally proposed uniting both Maxwell’s theory of electromagnetism and Einstein’s theory of general relativity by embeding both theories into a generally covarient fivedimensional space-time. Kaluza assumed that the fifth dimension was curled up into a tiny ring so small that it could not be experimentally observed by any instrument. Klein [2] then assumed that quantum corrections caused the fifth dimension to curl up. In quantum gravity, there is only one dimensionful parameter, which is the Planck length, or 10 cm. Since this sets the scale for quantum gravity, it means that the fifth dimension might have curled up with approximately this radius, which is
Framework for methodical review of literature on leadership competencies

The purpose of this paper is to examine and discuss scholarly literature on leadership competencies (LCs) through a multi-dimensional framework. This research adopts qualitative research method using scholarly literature. An attempt is made to combine the outcomes of these literatures into a more integrative framework of competency studies, offering a suggestion for further research. The findings reveal that the literature on LCs can be categorised using structured framework for better understanding. The literature has been categorised in different perspectives—Leadership levels, Function specific, Job specific, Geography specific, Generic Competency Specific. This framework provides the basis for future research to test the efficacy of framework. The framework provided in this paper incorporates main findings of previous research and as such it may serve as a starting point of practitioners in planning of different extended research in each of the dimensions identified. Subjects: Leadership; Human Resource Management; Human Resource Development
Deep Reinforcement Learning

We discuss deep reinforcement learning in an overview style. We draw a big picture, filled with details. We discuss six core elements, six important mechanisms, and twelve applications, focusing on contemporary work, and in historical contexts. We start with background of artificial intelligence, machine learning, deep learning, and reinforcement learning (RL), with resources. Next we discuss RL core elements, including value function, policy, reward, model, exploration vs. exploitation, and representation. Then we discuss important mechanisms for RL, including attention and memory, unsupervised learning, hierarchical RL, multiagent RL, relational RL, and learning to learn. After that, we discuss RL applications, including games, robotics, natural language processing (NLP), computer vision, finance, business management, healthcare, education, energy, transportation, computer systems, and, science, engineering, and art. Finally we summarize briefly, discuss challenges and opportunities, and close with an epilogue. 1
Hypercomputation by definition

Hypercomputation refers to computation surpassing the Turing model, not just exceeding the von Neumann architecture. Algebraic constructions yield a finitely based pseudorecursive equational theory (Internat. J. Algebra Comput. 6 (1996) 457-510). It is not recursive, although for each given number n, its equations in n variables form a recursive set. Hypercomputation is therefore required for an algorithmic answer to the membership problem of such a theory. Yet Alfred Tarski declared these theories to be decidable. The dilemma of a decidable but not recursive set presents an impasse to standard computability theory. One way to break the impasse is to predicate that the theory is computable--in other words, hypercomputation by definition.
Animating Interview Narratives

This chapter discusses the implications of viewing the interview as an actively constructed conversation through which narrative data are produced. It explores the ramifications of framing the interview and resulting data as by-products of interpretive practice the whats and hows of an animated process involving active subjects behind interview participants. Matters of reliability, validity, bias, and rigor are considered.
Diastolic function improvement is associated with favourable outcomes in patients with acute non-ischaemic cardiomyopathy: insights from the multicentre IMAC-2 trial.

AIMS
Patients with recent onset non-ischaemic cardiomyopathy have a variable clinical course with respect to recovery of left ventricular ejection fraction (LVEF). The aim of this study was to understand whether temporal changes in diastolic function (DF) are associated with clinical outcomes independent of LVEF recovery.


METHODS AND RESULTS
The Intervention in Myocarditis and Acute Cardiomyopathy (IMAC)-2 study was a prospective, multicentre trial investigating myocardial recovery in subjects with symptoms onset of <6 months and LVEF ≤40% of non-ischaemic dilated cardiomyopathy related to idiopathic cardiomyopathy or myocarditis. LVEF and DF were measured at presentation and at 6-month follow-up. Of 147 patients (mean age 46 ± 14 years, 40% female), baseline LVEF was 23 ± 8%. At 6 months, LVEF improved to 41 ± 12%, with 71% increasing by at least 10% ejection fraction units. DF improved in 58%, was unchanged in 28%, and worsened in 14%. Over a mean follow-up of 1.8 ± 1.2 years, there were 18 events: 11 heart failure (HF) hospitalizations, 3 deaths, and 4 heart transplants. LVEF (HR = 0.94, 95% CI 0.91-0.98, P = 0.002) and DF improvements at 6 months (HR = 0.32, 95% CI 0.11-0.92, P = 0.03) were independently associated with lower likelihood for the combined end point of death, transplantation, and HF hospitalization. Diastolic functional improvement at 6-month follow-up was as prognostically important as LVEF recovery for these patients, and provided incremental prognostic value to the risk stratification (X(2) increased from 12.6 to 18, P = 0.02).


CONCLUSION
In patients with recent onset non-ischaemic cardiomyopathy, DF recovery was associated with favourable outcomes independent of LVEF improvement, adding incremental prognostic value to these patients.
Multi-objective parametric optimization of powder mixed electro-discharge machining using response surface methodology and non-dominated sorting genetic algorithm

Powder mixed electro-discharge machining (EDM) is being widely used in modern metal working industry for producing complex cavities in dies and moulds which are otherwise difficult to create by conventional machining route. It has been experimentally demonstrated that the presence of suspended particle in dielectric fluid significantly increases the surface finish and machining efficiency of EDM process. Concentration of powder (silicon) in the dielectric fluid, pulse on time, duty cycle, and peak current are taken as independent variables on which the machining performance was analysed in terms of material removal rate (MRR) and surface roughness (SR). Experiments have been conducted on an EZNC fuzzy logic Die Sinking EDM machine manufactured by Electronica Machine Tools Ltd. India. A copper electrode having diameter of 25 mm is used to cut EN 31 steel for one hour in each trial. Response surface methodology (RSM) is adopted to study the effect of independent variables on responses and develop predictive models. It is desired to obtain optimal parameter setting that aims at decreasing surface roughness along with larger material removal rate. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying both the objectives in any one solution. Therefore, it is essential to explore the optimization landscape to generate the set of dominant solutions. Non-sorted genetic algorithm (NSGA) has been adopted to optimize the responses such that a set of mutually dominant solutions are found over a wide range of machining parameters.
The market reaction to social responsibility disclosures: The case of the Sullivan principles signings☆

Abstract Few studies to date have tested for investor use of social responsibility information disclosures. This paper examines the stock trading volume and price return reaction to the 1977 disclosures that certain United States companies doing business in South Africa had agreed to the Sullivan Principles. Results indicate that non-signing firms experienced significantly higher unexpected trading volume than signing firms around the announcement date. As such, the findings represent further evidence of investor use of social responsibility information.
Theory Review of Exclusive Rare Radiative Decays

Experimental measurements of B → V γ decays, with V a light vector meson such as K, ρ, ω, φ, have continued to improve and will become more precise at the end of the B-factories and at LHC-b. Given their rich CKM phenomenology and potential to constrain new physics models, having reliable theory predictions for these decays is increasingly relevant. In this talk I briefly review the status of this area. The starting point is the effective weak Hamiltonian, which for B → V γ decays is [1]:
Pulmonary vein ostium geometry: analysis by magnetic resonance angiography.

BACKGROUND
During a catheter ablation procedure for selective electrical isolation of pulmonary vein (PV) ostia, the size of these ostia is usually estimated using fluoroscopic angiography. This measurement may be misleading, however, because only the projected supero/inferior ostium diameters can be measured. In this study, we analyzed 3-dimensional magnetic resonance angiographic (MRA) images to measure the minimal and maximal cross-sectional diameter of PV ostia in relation to the diameter that would have been projected on fluoroscopic angiograms during a catheter ablation procedure.


METHODS AND RESULTS
In 42 patients with idiopathic atrial fibrillation who were scheduled for selective electrical isolation of PV ostia, the minimal and maximal diameters of these ostia were measured from 3-dimensional MRA images. Thereafter, these images were oriented in a 45 degrees right or left anterior oblique direction and the projected diameter of the PV ostia were measured again. The average ratio between maximal and minimal diameter was 1.5+/-0.4 for the left and 1.2+/-0.1 for the right pulmonary vein ostia. Because of the orientation and oval shape of especially the left pulmonary vein ostia, their minimal diameters were significantly smaller than the projected diameters.


CONCLUSION
Pulmonary vein ostia, especially those at the left, are oval with the short axis oriented approximately in the antero/posterior direction. Consequently, PV ostia may sometimes be very narrow despite a rather normal appearance on angiographic images obtained during a catheter ablation procedure.
Augmentation of macular pigment following implantation of blue light-filtering intraocular lenses at the time of cataract surgery.

PURPOSE
(Photo)-oxidative stress is believed to play a role in the pathogenesis of age-related macular degeneration (AMD), with the threshold for retinal damage being lowest for short-wavelength (blue) light. Macular pigment (MP), consisting of the carotenoids lutein (L), zeaxanthin (Z) and meso-Z, has a maximum absorption at 460 nm and protects the retina from (photo)-oxidative injury. This study was designed to investigate whether the blue light-filtering properties of the Alcon AcrySof Natural intraocular lens (ANIOL) implanted during cataract surgery affects MP optical density (MPOD).


METHODS
Forty-two patients scheduled for cataract surgery were recruited for the study. These patients all had a preoperative best corrected visual acuity rating (BCVAR) of at least 0.5 (logMAR) in the study eye. The patients were randomized to have either the standard Alcon AcrySof three-piece acrylic intraocular lens (AIOL) (controls) or the ANIOL implanted at the time of cataract surgery. The spatial profile of MPOD (i.e., at 0.25 degrees, 0.5 degrees, 1.0 degrees, and 1.75 degrees eccentricity) was measured with customized heterochromatic flicker photometry (cHFP) 1 week before and 1 week after surgery, and at 3, 6, and 12 months after surgery. Serum concentrations of L and Z were also measured at each study visit.


RESULTS
There was a highly significant and positive correlation between all MPODs (e.g., at 0.25 degrees) recorded 1 week before and after surgery in eyes with an AIOL implant (r = 0.915, P < 0.01; paired samples t-test, P = 0.631) and in those ANIOL implants (r = 0.868, P < 0.01; paired samples t-test, P = 0.719). Average MPOD across the retina increased significantly with time (after 3 months) in the ANIOL group (repeated-measures, general linear model, P < 0.05), but remained stable in the AIOL group (repeated-measures, general linear model, P > 0.05). There were no significant time or lens effects observed for serum L over the study period (P > 0.05). There was a significant time effect for serum Z over the study period (P < 0.05), but not a significant time/lens interaction (P > 0.05).


CONCLUSIONS
Customized HFP can reliably measure the MPOD spatial profile in the presence of lens opacity, and cataract surgery does not artifactually alter MPOD readings. This study also provides evidence that implanting an IOL that filters blue light is associated with augmentation of MPOD in the absence of raised serum concentrations of L and Z. However, further and longitudinal study is needed to assess whether the observed increase in MPOD after implantation of blue-filtering IOLs is associated with reduced risk of AMD development and/or progression.
TISSUE PLASMINOGEN ACTIVATOR IN CARDIAC ARREST WITH PULSELESS ELECTRICAL ACTIVITY

A BSTRACT Background Coronary thrombosis and pulmonary thromboembolism are common causes of cardiac arrest. We assessed whether the administration of tissue plasminogen activator (t-PA) during cardiopulmonary resuscitation would benefit patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause. Methods Patients who were older than 16 years of age and who had more than one minute of pulseless electrical activity that was unresponsive to initial therapy outside the hospital or in the emergency department were eligible. Patients were randomly assigned to receive 100 mg of t-PA or placebo intravenously over a 15-minute period in a double-blind fashion. Standard resuscitation was then continued for at least 15 minutes. The primary outcome was survival to hospital discharge. Results During the study period, 1583 patients with cardiac arrest were treated and 233 patients were enrolled (117 in the t-PA group and 116 in the placebo group). The characteristics of the patients in the two groups were similar. One patient in the t-PA group survived to hospital discharge, as compared with none in the placebo group (absolute difference between groups, 0.9; 95 percent confidence interval, ¡2.6 to 4.8; P=0.99). The proportion of patients with return of spontaneous circulation was 21.4 percent in the t-PA group and 23.3 percent in the placebo group (absolute difference between groups, ¡1.9; 95 percent confidence interval, ¡12.6 to 8.8; P=0.85). Conclusions We found no evidence of a beneficial effect of fibrinolysis in patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause. Our study had limited statistical power, and it remains unknown whether there is a small treatment effect or whether selected subgroups may benefit. (N Engl J Med 2002;346:1522-8.)
Padrão de qualidade de mudas de Trema micrantha (L.) Blume, produzidas sob diferentes períodos de sombreamento

This work aimed to verify the influence of the under shading period in the parameters employed to evaluate Trema micrantha (crindiúva) seedling quality pattern. The research was carried out using a randomized design, with four replications per treatment and 88 plants per replication. Three evaluations were performed at 90, 120 and 150 days after emergence. The following treatments were used in the evaluation: Evaluation I, 45, 60, 75 and 90; Evaluation II, 45, 60, 75, 90, 105 and 120 and Evaluation III, 45, 60, 75, 90, 105, 120, 135 and 150 days under shading with 48% of solar radiation retention, respectively. The morphological parameters of the seedlings, their relationships, and the Dickson quality index were evaluated. Seedlings developed under the longer shading periods presented higher shoot heights and leaf area but the lowest values for seedling quality, such as smaller stem diameter, root dry mass and the Dickson quality index. They also presented an increase in shoot height/stem diameter and shoot/root ratios. Period under shading did not affect significantly the parameters for leaf area, leaf dry mass, shoot and total. Seedlings showed better quality patterns at 120 days, when grown under 45 and 60 days under shading. The Dickson’s quality index was the best and the most suitable parameter to evaluate the target seedling grown in a suspended nursery.
Probabilistic Analysis of Small-Signal Stability of Large-Scale Power Systems as Affected by Penetration of Wind Generation

This paper proposes a method of probabilistic analysis to investigate the impact of stochastic uncertainty of grid-connected wind generation on power system small-signal stability. The proposed method is “analytical” in contrast to the numerical method of Monte Carlo simulation which relies on large number of random computations. It can directly calculate the probabilistic density function (PDF) of critical eigenvalues of a large-scale power system from the PDF of grid-connected multiple sources of wind power generation, thus to determine the probabilistic small-signal stability of the power system as affected by the wind generation. In the paper, an example of 16-machine power system with three grid-connected wind farms is used to demonstrate the application of the proposed method. The results of probabilistic stability analysis of the example power system are confirmed by the Monte Carlo simulation. It is shown that the stochastic variation of grid-connected wind generation can cause the system to lose stability even though the system is stable deterministically. The higher the level of wind penetration is, the more the probability that the system becomes unstable could be. Hence indeed penetration of stochastically variable wind generation threatens stable operation of power systems as far as system small-signal stability is concerned.