bluuebunny/crossref_metadata_2025 huggingface dataset:
International business negotiations in a regulated and incomplete information market
Authors: Peleckis Kęstutis , Peleckienė Valentina , Peyravi Bahman , Leonavičienė Edita
Published: June 2020

Regulations and government interventions often restrict competition in the market and rise cer-tain challenges in business negotiations, when competition in the market is more or less distorted. Remov-ing unnecessary restrains to competition and developing alternatives which still achieve the same policy objectives can bring substantial benefits for negotiation power of market business entities. Competition as-sessment is most effective when business negotiation entities have a clear sufficient information for com-paring options, sufficient resources for conducting an analysis, and sufficient technical skills for perform-ing the analysis. The aim of this article is to analyze in complex the unfolding theory and practice of development and implementation of business negotiating strategies in a regulated and incomplete infor-mation market, to reveal opportunities on development and implementing improvements of these strate-gies. Object of the research is the search of balance on negotiating powers in business negotiations in a regulated and incomplete information market. The scientific problem – negotiation theory lacks measures for assessment and balancing the negotiating powers between negotiation participants in a regulated and incomplete information market.
Models of implementing innovative technologies into industry
Authors: Walasik Marzena , Poteralska Beata
Published: June 2020

The paper is aimed at identifying the state-of-the-art in the field of traditional and innovative management of a new product (the result of R&D works). Against this background, key elements of the management process of new product development (NPD) at R&D organisations, are identified. The main components of the management process comprise the developed implementation models and dedicated marketing tools, with taking into account the specific character of an R&D organisation, whose activities should be focused on the commercialisation of obtained research results.
Decoupling in the perspective of responsibility
Authors: Adamus-Matuszyńska Anna , Polok Grzegorz
Published: June 2020

The principal objective of the article is to examine responsibility as a value helping to enhance the ability of organisation to deal with highly institutionalised environment in which it operates, and which has an impact on the decoupling process. The authors put forward a hypothesis that the development of the sphere of responsibility may support to deal with the complexity of organisation and its environment. To verify the hypothesis the review of literature was undertaken as the research method. Decoupling process is neither good nor bad although it bears ethical dilemmas. The results of the literature examination let to make the conclusion that responsibility is a value that allows organization to solve dilemmas resulting from the complexity and controversy of the decoupling phenomenon. The authors propose to concentrate on the individuals managing and co-forming the organisation in the light of responsibility.
Evaluation of knowledge transfer internationalisation level
Authors: Misiūnaite Rasa , Žemaitis Eigirdas
Published: June 2020

Knowledge and the ability to transfer it effectively becomes a valuable skill, that goes beyond a particular business sector. In 2015 United Nations developed the 2030 Agenda for Sustainable Develop-ment Goals (SDG), which emphasize global partnership and collaboration as some of the key criteria in order to achieve tangible results. Authors raise the hypothesis about a set of national level criteria, which help to forecast the level of European Union countries contribution to SDG. Research aims to evaluate EU countries’ potential to contribute to 17 SDG, by measuring the level of international knowledge transfer. Authors analyze scientific approaches to knowledge transfer, its measurement, match selected measure-ment aspects with corresponding data from Global Competitiveness Index and rank EU countries by using TOPSIS multi-criteria decision making method.
Assessment of influence of management transformations and risk for tourism business
Authors: Dzemydienė Dalė , Ragab Mohamed Hamdy-Elmeselhy-Aly
Published: June 2020

The reality of development of tourism business is faced with problems of unsuspected events and unsustainable management issues. This research explores the need to evaluate the types of risk in tourism business sector. The aim of this research is to analyze the situations of local and global business in the area of management transformations in tourism sector. For empirical evaluation of situation the statistical data are analyzed in case study of Egypt tourism sector during the period of 10 years. The models are proposed for application, such as environmentally sustainable tourism planning, adapting roles of tourism stakeholders, integration of private investors, action plans. The results demonstrate the lack of signiﬁcant sustainable development practices under the conditions of unsuspectability and show interest in this area by needs for further contribution involving triple bottom line of objectives. The some factors are found as risk of political changes, lack of skills, ﬁnance etc.
Financial indicators in the system of economic security of the world countries
Authors: Hrybinenko Olha Hrybinenko , Bulatova Olena , Zakharova Olha
Published: June 2020

The paper is aimed at quantitative evaluation of the level of countries’ financial solvency based on the use of a multidimensional methodical toolkit for evaluating financial indicators of a country’s development, which results in the construction of the appropriate integral security indices. Unlike other methods to assess the level of security, the proposed approach makes it possible to determine not only the integrated level of a financial component of the economic security but also to calculate the quantitative thresholds of the financial indicators aggregated in the integral index (gold and currency reserves, external debt per capita, changes in the official local currency rate, budget deficit/surplus to GDP); going beyond the threshold values is a signal of the increased risk and lack of solvency. Comprehensive consideration of the financial indicators, taken from the official statictic databases or calculated basing on the official statictics, in the structure of the integral index helps quantify the level of a financial component in the system of ensuring countries’ economic security. The proposed approach is approbated in terms of the countries for which the level of a component of the financial solvency (critical, dangerous, unsatisfactory, safe, and optimal) has been calculated. From the practical viewpoint, the proposed toolkit makes it possible to identify actual and potential threats to the countries’ sustainable development. The obtained integral indices of security can be used as the variables in economic and mathematical models while evaluating the effect of security status on the global economic development and positions of certain countries, communities, and regions in the system of world economic relationships.
Sources of Bipolar Outflows and Model Challenges for the Egg Nebula
Authors: Dinh-V-Trung  , Lim Jeremy , Ohyama Youichi
Published: June 2020

The striking features of the Egg Nebula—searchlight beams that illuminate a pair of bipolar lobes, quadrupolar outflows, and arcs imprinted on an expanding spherical envelope—have long defied a coherent explanation. Here we present images at high angular resolutions of emission from dust and dense molecular gas in the nebula. Away from the systemic velocity, the molecular gas primarily traces the walls of the bipolar lobes, where bipolar outflows collide with the envelope ejected by the progenitor AGB star. At and close to the systemic velocity, both the molecular gas and dust trace the walls of a cylindrical channel swept aside by these bipolar outflows; in addition, the dust also traces a channel orthogonal to the bipolar lobes, swept aside by the orthogonal set of bipolar outflows. Close to the center, the dense gas traces an expanding spherical shell, corresponding to a very dense final puff from the progenitor AGB star. The center of this shell lies within the channel aligned with the optical lobes but is displaced to the south of the channel orthogonal to these lobes, and it closely coincides with the illumination center of the nebula (location of post-AGB star), as well as the expansion center of the bipolar lobes. We highlight difficulties faced by models whereby a binary companion both induces arcs in the wind of the progenitor AGB star and gives rise to the quadrupolar outflows. Instead, we suggest that the addition of a second companion, thus forming a triple-star system, can naturally produce all the features seen.
Testing Rotating Regular Metrics as Candidates for Astrophysical Black Holes
Authors: Kumar Rahul , Kumar Amit , Ghosh Sushant G.
Published: June 2020

The Event Horizon Telescope, a global submillimeter wavelength very long baseline interferometry array, produced the first image of supermassive black hole M87* showing a ring of diameter θ

d
 = 42 ± 3 μas, inferred a black hole mass of M = (6.5 ± 0.7) × 109
M
⊙, and allowed us to investigate the nature of strong-field gravity. The observed image is consistent with the shadow of a Kerr black hole, which according to the Kerr hypothesis describes the background spacetimes of all astrophysical black holes. The hypothesis, a strong-field prediction of general relativity, may be violated in the modified theories of gravity that admit non-Kerr black holes. Here, we use the black hole shadow to investigate the constraints when rotating regular black holes (non-Kerr) can be considered as astrophysical black hole candidates, paying attention to three leading regular black hole models with additional parameters g related to nonlinear electrodynamics charge. Our interesting results based on the systematic bias analysis are that rotating regular black holes shadows may or may not capture Kerr black hole shadows, depending on the values of the parameter g. Indeed, the shadows of Bardeen black holes (g ≲ 0.26M), Hayward black holes (g ≲ 0.65M) and non-singular black holes (g ≲ 0.25M) are indistinguishable from Kerr black hole shadows within the current observational uncertainties, and thereby they can be strong viable candidates for the astrophysical black holes. Whereas Bardeen black holes (g ≤ 0.30182M), Hayward black holes (g ≤ 0.73627M), and non-singular black holes (g ≤ 0.30461M), within the 1σ region for θ

d
 = 39 μas, are consistent with the observed angular diameter of M87*.
HST Survey of the Orion Nebula Cluster in the H2O 1.4 μm Absorption Band. III. The Population of Substellar Binary Companions
Authors: Strampelli Giovanni M. , Aguilar Jonathan , Pueyo Laurent , Aparicio Antonio , Gennaro Mario , Ubeda Leonardo , Robberto Massimo
Published: June 2020

We present new results concerning the substellar binary population in the Orion Nebula Cluster (ONC). Using the Karhunen–Loève Image Projection algorithm, we have reprocessed images taken with the IR channel of the Wide Field Camera 3 mounted on the Hubble Space Telescope to unveil faint, close companions in the wings of the stellar point-spread functions. Starting with a sample of 1392 bona fide unsaturated cluster members, we detect 39 close-pair cluster candidates with separation 0.″16–0.″77. The primary masses span a range M

p
 ∼ 0.015–1.27 M
☉, whereas for the companions we derive M

c
 ∼ 0.004–0.54 M
☉. Of these 39 binary systems, 18 were already known, while the remaining 21 are new detections. Correcting for completeness and combining our catalog with previously detected ONC binaries, we obtain an overall binary fraction of 11.5% ± 0.9%. Compared to other star-forming regions, our multiplicity function is ∼2 times smaller than, for example, Taurus, while compared to the binaries in the field we obtain comparable values. We analyze the mass functions of the binaries, finding differences between the mass distributions of binaries and single stars and between primary and companion mass distributions. The mass ratio shows a bottom-heavy distribution with median value M

c
/M

p
 ∼ 0.25. Overall, our results suggest that ONC binaries may represent a template for the typical population of field binaries, supporting the hypothesis that the ONC may be regarded as a most typical star-forming region in the Milky Way.
Very Long Baseline Astrometry of PSR J1012+5307 and its Implications on Alternative Theories of Gravity
Authors: Ding Hao , Deller Adam T. , Freire Paulo , Kaplan David L. , W. Lazio T. Joseph , Shannon Ryan , Stappers Benjamin
Published: June 2020

PSR J1012+5307, a millisecond pulsar in orbit with a helium white dwarf (WD), has been timed with high precision for about 25 yr. One of the main objectives of this long-term timing is to use the large asymmetry in gravitational binding energy between the neutron star and the WD to test gravitational theories. Such tests, however, will be eventually limited by the accuracy of the distance to the pulsar. Here, we present very long baseline interferometry (VLBI) astrometry results spanning approximately 2.5 yr for PSR J1012+5307, obtained with the Very Long Baseline Array as part of the

project. These provide the first proper motion and absolute position for PSR J1012+5307 measured in a quasi-inertial reference frame. From the VLBI results, we measure a distance of

kpc (all the estimates presented in the abstract are at 68% confidence) for PSR J1012+5307, which is the most precise obtained to date. Using the new distance, we improve the uncertainty of measurements of the unmodeled contributions to orbital period decay, which, combined with three other pulsars, places new constraints on the coupling constant for dipole gravitational radiation

and the fractional time derivative of Newton’s gravitational constant

in the local universe. As the uncertainties of the observed decays of orbital period for the four leading pulsar-WD systems become negligible in ≈10 yr, the uncertainties for

and κ

D
will be improved to ≤1.5 × 10−13 yr−1 and ≤1.0 × 10−4, respectively, predominantly limited by the distance uncertainties.
The Three Young Nuclear Super Star Clusters in NGC 5253
Authors: Smith Linda J. , Bajaj Varun , Ryon Jenna , Sabbi Elena
Published: June 2020

The blue compact dwarf galaxy NGC 5253 hosts a very young central starburst. The center contains intense radio thermal emission from a massive ultracompact H ii region (or supernebula) and two massive and very young super star clusters (SSCs), which are seen at optical and infrared wavelengths. The spatial correspondence between these three objects over an area of

is very uncertain, and it is usually assumed that one of the optically detected SSCs coincides with the supernebula. Using the Gaia Data Release 2 catalog, we improve the absolute astrometry of Hubble Space Telescope ultraviolet, optical, and infrared images by a factor of ∼10 and match them to the radio observations with an accuracy of 10–20 mas. We find that there are three SSCs at the center of NGC 5253. At optical wavelengths, the two SSCs lie on either side of the supernebula, which coincides with a highly obscured region. In the infrared, all three SSCs are seen with the supernebula dominating at the longest wavelengths. We examine the properties of the SSCs, which have ages of ∼1 Myr, are very compact (

pc), and are separated by projected distances of only 1.5 and 5.8 pc. It seems likely that they will merge and may form the building blocks for nuclear star clusters.
Discovery of a Universal Correlation for Long and Short GRBs and Its Application for the Study of Luminosity Function and Formation Rate
Authors: Guo Qi , Wei Da-Ming , Wang Yuan-Zhu , Jin Zhi-Ping
Published: June 2020

Gamma-ray bursts (GRBs) are known to be the most violent explosions in the universe, and a variety of correlations between observable GRB properties have been proposed in the literature, but none of these correlations are valid for both long and short GRBs. In this paper we report the discovery of a universal correlation that is suitable for both long and short GRBs using three prompt emission properties of GRBs, i.e., the isotropic peak luminosity L
iso, the peak energy of the time-integrated prompt emission spectrum E
peak, and the “high signal” timescale T
0.45,

. This universal correlation involves properties of GRB prompt emission and does not require knowledge of the afterglow phase, which can be used as a relatively unbiased redshift estimator. Here we use this correlation to estimate the pseudoredshifts for short GRBs and then use the Lynden–Bell method to obtain a nonparametric estimate of their luminosity function and formation rate. The luminosity function is

for dim SGRBs and

for bright SGRBs, with the break point

. The local formation rate of SGRBs is about 15 events Gpc−3 yr−1 . This universal correlation may have important implications for GRB physics, implying that the long and short GRBs should share similar radiation processes.
HST Survey of the Orion Nebula Cluster in the H2O 1.4 μm Absorption Band. I. A Census of Substellar and Planetary-mass Objects
Authors: Robberto Massimo , Gennaro Mario , Ubeira Gabellini Maria Giulia , Hillenbrand Lynne A. , Pacifici Camilla , Ubeda Leonardo , Andersen Morten , Barman Travis , Bellini Andrea , Rio Nicola Da , de Mink Selma E. , Lodato Giuseppe , Manara Carlo Felice , Platais Imants , Pueyo Laurent , Strampelli Giovanni Maria , Tan Jonathan C. , Testi L.
Published: June 2020

In order to obtain a complete census of the stellar and substellar population, down to a few

 in the ∼1 Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4 μm H2O absorption feature and an adjacent line-free continuum region. Out of 4504 detected sources, 3352 (about 75%) appear fainter than m
130 = 14 (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass (

) at ∼1 Myr. Of these, however, only 742 sources have a negative F130M–F139N color index, indicative of the presence of H2O vapor in absorption, and can therefore be classified as bona fide M and L dwarfs, with effective temperatures T ≲ 2850 K at an assumed 1 Myr cluster age. On our color–magnitude diagram (CMD), this population of sources with H2O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M–F139N color index and can be traced down to the sensitivity limit of our survey, m
130 ≃ 21.5, corresponding to a 1 Myr old ≃3

planetary-mass object under about 2 mag of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of 1, 2, and 3 Myr down to ∼1

fail to reproduce the observed H2O color index at M ≲ 20

. We perform a Bayesian analysis to determine extinction, mass, and effective temperature of each substellar member of our sample, together with its membership probability.
Effects of General Relativistic Spin Precessions on the Habitability of Rogue Planets Orbiting Supermassive Black Holes
Authors: Iorio Lorenzo
Published: June 2020

Recently, the possibility that several starless telluric planets may form around supermassive black holes (SMBHs) and receive energy input from the hole’s accretion disk, which, under certain plausible circumstances, may make them habitable in a terrestrial sense, has gained increasing attention. In particular, an observer on a planet orbiting at distance r = 100 Schwarzschild radii from a maximally rotating Kerr SMBH with mass M
• = 1 × 108
M
⊙ in a plane slightly outside the equator of the latter, would see the gravitationally lensed accretion disk the same size as the Sun as seen from Earth. Moreover, the accretion rate might be imagined to be set in such a way that the apparent disk’s temperature would be identical to that of the solar surface. We demonstrate that the post-Newtonian (pN) de Sitter and Lense–Thirring precessions of the spin axis of such a world would rapidly change, among other things, its tilt, ε, to its orbital plane by tens to hundreds of degrees over a time span of, say, just Δt = 400 yr, strongly depending on the obliquity η
• of the SMBH’s spin to the orbital plane. Thus, such relativistic features would have per se a relevant impact on the long-term habitability of the considered planet. Other scenarios are examined as well.
Pulsar Glitch Detection with a Hidden Markov Model
Authors: Melatos A. , Dunn L. M. , Suvorova S. , Moran W. , Evans R. J.
Published: June 2020

Pulsar timing experiments typically generate a phase-connected timing solution from a sequence of times of arrival (TOAs) by absolute pulse numbering, i.e., by fitting an integer number of pulses between TOAs in order to minimize the residuals with respect to a parameterized phase model. In this observing mode, rotational glitches are discovered, when the residuals of the no-glitch phase model diverge after some epoch, and glitch parameters are refined by Bayesian follow-up. Here, we present an alternative, complementary approach which tracks the pulse frequency f and its time derivative

with a hidden Markov model (HMM), whose dynamics include stochastic spin wandering (timing noise) and impulsive jumps in f and

(glitches). The HMM tracks spin wandering explicitly, as a specific realization of a discrete-time Markov chain. It discovers glitches by comparing the Bayes factor for glitch and no-glitch models. It ingests standard TOAs for convenience, and being fully automated, allows performance bounds to be calculated quickly via Monte Carlo simulations. Practical, user-oriented plots of the false-alarm probability and detection threshold (e.g., minimum resolvable glitch size) versus observational scheduling parameters (e.g., TOA uncertainty, mean delay between TOAs) and glitch parameters (e.g., transient and permanent jump sizes, exponential recovery timescale) are presented. The HMM is also applied to ∼1 yr of real data bracketing the 2016 December 12 glitch in PSR J0835−4510 as a proof of principle. It detects the known glitch and confirms that no other glitch exists in the same data with size ≳10−7
f.
The PHLEK Survey: A New Determination of the Primordial Helium Abundance
Authors: Hsyu Tiffany , Cooke Ryan J. , Prochaska J. Xavier , Bolte Michael
Published: June 2020

We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the He i λ10830 Å emission line, due to its sensitivity to the physical conditions of the gas in H ii regions. We use these NIR observations, combined with optical spectroscopy, to determine the helium abundance of sixteen galaxies across a metallicity range

 = 7.13–8.00. This data set is combined with two other samples where metallicity and helium abundance measurements can be secured: star-forming galaxies selected from the Sloan Digital Sky Survey spectroscopic database, and existing low-metallicity systems in the literature. We calculate a linear fit to these measurements, accounting for intrinsic scatter, and report a new determination of the primordial helium number abundance,

, which corresponds to a primordial helium mass fraction

. Using our determination of the primordial helium abundance in combination with the latest primordial deuterium measurement,

, we place a bound on the baryon density

and the effective number of neutrino species

. These values are in 1.3σ agreement with those deduced from the Planck satellite observations of the temperature fluctuations imprinted on the cosmic microwave background.
On the Origin of the Gamma-Ray Emission toward SNR CTB 37A with Fermi-LAT
Authors: Abdollahi Soheila , Ballet Jean , Fukazawa Yasushi , Katagiri Hideaki , Condon Benjamin
Published: June 2020

The middle-aged supernova remnant (SNR) CTB 37A is known to interact with several dense molecular clouds through the detection of shocked H2 and OH 1720 MHz maser emission. In the present work, we use eight years of Fermi-LAT Pass 8 data, with an improved point-spread function and an increased acceptance, to perform detailed morphological and spectral studies of the γ-ray emission toward CTB 37A from 200 MeV to 200 GeV. The best fit of the source extension is obtained for a very compact Gaussian model with a significance of 5.75σ and a 68% containment radius of 0.°116 ± 0.°014stat  ± 0.°017sys above 1 GeV, which is larger than the TeV emission size. The energy spectrum is modeled as a LogParabola, resulting in a spectral index α = 1.92 ± 0.19 at 1 GeV and a curvature β = 0.18 ± 0.05, which becomes softer than the TeV spectrum above 10 GeV. The SNR properties, including a dynamical age of 6000 yr, are derived assuming the Sedov phase. From the multiwavelength modeling of emission toward the remnant, we conclude that the nonthermal radio and GeV emission is mostly due to the reacceleration of preexisting cosmic rays (CRs) by radiative shocks in the adjacent clouds. Furthermore, the observational data allow us to constrain the total kinetic energy transferred to the trapped CRs in the clouds. Based on these facts, we infer a composite nature for CTB 37A to explain the broadband spectrum and to elucidate the nature of the observed γ-ray emission.
The SAMI Galaxy Survey: Stellar Population Gradients of Central Galaxies
Authors: Santucci Giulia , Brough Sarah , Scott Nicholas , Montes Mireia , Owers Matt S. , van Sande Jesse , Bland-Hawthorn Joss , Bryant Julia J. , Croom Scott M. , Ferreras Ignacio , Lawrence Jon S. , López-Sánchez Ángel R. , Richards Samuel N.
Published: June 2020

We examine the stellar population radial gradients (age, metallicity, and [α/Fe]) of 96 passive central galaxies up to ∼2 R

e
in the SAMI Galaxy Survey. The targeted groups have a halo mass range of

. The main goal of this work is to determine whether central galaxies have different stellar population properties when compared to similarly massive satellite galaxies. For the whole sample, we find negative metallicity radial gradients, which show evidence of becoming shallower with increasing stellar mass. The age and [α/Fe] gradients are slightly positive and consistent with zero, respectively. The [α/Fe] gradients become more negative with increasing mass, while the age gradients do not show any significant trend with mass. We do not observe a significant difference between the stellar population gradients of central and satellite galaxies at fixed stellar mass. The mean metallicity gradients are

for central galaxies and

for satellites. The mean age and [α/Fe] gradients are consistent between central and satellite galaxies, within the uncertainties, with a mean value of

for centrals and

for satellites and

for centrals and

for satellites. The stellar population gradients of central and satellite galaxies show no difference as a function of halo mass. This evidence suggests that the inner regions of central passive galaxies form in a similar fashion to those of satellite passive galaxies, in agreement with a two-phase formation scenario.
Possible Evidence from the Flaring Activity of Sgr A* for a Star at a Distance of ∼3.3 Schwarzschild Radii from the Black Hole
Authors: Leibowitz Elia
Published: June 2020

The frequent flaring events in the X-ray and the near-IR (NIR) radiation of Sgr A* seem not to be periodic in time. However, statistical regularities, here termed “modulations by a pacemaker,” are found in the recorded arrival times of both types of events. The characteristic time of the X-ray pacemaker is 149 minutes, and that of the NIR pacemaker is 40 minutes. Their reality as derived from observed data can be accepted at larger than 4.6σ and 3.8σ levels of statistical confidence, respectively. These results can be interpreted as evidence for a star that revolves around the black hole (BH) of Sgr A* in a slightly elliptical precessing orbit, at a distance of 3–3.5 Schwarzschild radii of the BH. The period of the X-ray pacemaker, which is not a periodicity of the flare occurrences themselves, is the epicyclic period of the star orbital motion. This is the time interval between two successive passages of the star through the pericenter of its orbit. The NIR pacemaker period is the mean sidereal binary period of the star revolution. The origin of the X-ray flares is in episodes of intense mass loss from the star that occur preferably near the pericenter phase of the binary revolution. The NIR flares originate or are triggered by processes that are internal to the star. The radiation emitted in the direction of Earth is slightly modulated by the changing aspect ratio of the two components of the BH/star binary to the line of sight from Earth at the sidereal binary frequency.
Stochastic Fragmentation in Protoplanetary Disks under External Irradiation
Authors: Tang Pengfei , Jin Liping , Zhong Jiayong
Published: June 2020

It has been shown that disk fragmentation within several tens of au from the star is very difficult when the gravitational instability and cooling time criterion are considered. However, in the stochastic fragmentation scenario, things may be different. We investigate stochastic fragmentation in protoplanetary disks. In the stochastic fragmentation model, we consider the effects of the external irradiation on the fragmentation process. For the stochastic fragmentation, owing to the probability of generating bound fragments at longer cooling times relative to the critical value and the short collapsing times in the external irradiation region, the inner boundary of the fragmentation region extends inward to 19 au. We find that the required self-gravitating lifetime for fragmentation in the external irradiation region is far less than the self-gravitating lifetime of the disk. Therefore, once a radius is in the external irradiation region, the fragmentation probability increases quickly to 1 after gravitational instability sets in, and fragmentation occurs within a short period of time. We also find that the self-gravitating lifetime required for fragmentation decreases significantly as the radius increases in the external irradiation region.
Grasslands on Coastal Headlands in New South Wales, south eastern Australia
Authors: Hunter John
Published: June 2020

Aims: To use unsupervised techniques to produce a hierarchical classification of grasslands on coastal headlands of New South Wales in eastern Australia.Methods: A dataset of 520 vegetation plots scored on cover and placed across grasslands on coastal headlands (ca. 2000 km of coastline). Vegetation assemblages were identified with the aid of a clustering method based on group averaging and tested using similarity profile analysis (SIMPROF) using Bray-Curtis similarity. A hierarchical schema was developed based on EcoVeg hierarchy and was circumscribed using positive and negative diagnostic taxa via similarity percentage analysis (SIMPER) and importance based on summed cover scores and frequency. Mapping the occurrences grasslands was initially constructed using remote sensing which was verified and modified with on ground observations.Results: One groupThemeda – Pultenaea – Zoysia – Cynodongrasslands and heathy grasslands was defined to include all coastal headland grassland vegetation of the New South Wales, and within this, three alliances and ten associations. Only one of the circumscribed associations is represented within the current state classification schema. In total 107 ha were mapped of which 68 ha occurred within secure conservation tenure.Conclusions: A number of unique and rare grassland assemblages on coastal headlands have to date gone undescribed. The most common alliance constitutes approximately 87% of extant grassland occurrences but is currently the only type listed as endangered and afforded protection. AlthoughPoaspp. are listed as a threat toThemedadominated assemblages on headlands data from this study suggest that this is unlikely to be the case.

Taxonomic reference: PlantNET (http://plantnet/10rbgsyd.nsw.gov.au/; accessed June 2019).

Abbreviations: BC Act = Biodiversity Conservation Act; NMDS = non-metric multidimensional scaling; NSW = New South Wales; PCT = Plant Community Type; SIMPER = similarity percentage analysis; SIMPROF = Similarity profile analysis.
Textures de la surface : le sol et la page
Authors: Ingold Tim , Goyet Samuel , Descouens Martine , Souchier Emmanuël
Published: June 2020

En partant de l’intérêt renouvelé pour les surfaces en tant que lieu de production du sens, cet article compare deux types de surface : la page et le sol. Dans l’Europe médiévale, la lecture était vue comme une promenade dans un paysage, les lignes inscrites sur le parchemin similaires aux chemins tracés sur le sol. Suivant cette analogie, le sol est comme un parchemin utilisé à de nombreuses reprises : un palimpseste. Mais en tant que surface, le palimpseste se construit en enlevant des couches. Il obéit à un principe anti-stratigraphique. Comment se fait-il, alors, que les Modernes ont tendance à considérer la page et le sol en des termes stratigraphiques ? La réponse à cette question se trouve dans les technologies du pavage et de l’imprimerie. Ces dernières opèrent une séparation entre notre imagination et notre façon d’habiter la terre. Est-il alors possible de réunir les deux ? La conclusion de cet article propose deux manières de faire, en passant par des exemples littéraires. Ce qui est en jeu, ce sont des façons différentes de penser l’esprit : comme un palimpseste ou comme un substrat. Peut-être qu’en revenant à la conception médiévale de la lecture comme promenade, on peut finalement redonner à la géographie son sens littéral : celui d’une écriture de la terre.
Pourquoi Illich n’a-t-il pas formulé une vision alternative de l’informatique ?
Authors: Aigrain Philippe
Published: June 2020

L’article pose la question suivante : pourquoi Illich n’a pas développé une vision alternative de l’informatique alors qu’il aurait pu y être poussé par son approche des techniques ? On commence par étayer l’affirmation selon laquelle Illich disposait notamment avec son concept de monopole radical des outils nécessaires à la construction d’une vision alternative de l’informatique, si ce n’est dans les années 1970, du moins dans les années 1980 après la naissance de l’informatique personnelle. Analysant les raisons qui ont pu pousser Illich à conserver une vision essentialiste et négative de l’informatique, on pointe en particulier sa vision de la lecture, profondément enracinée dans ses positions religieuses, et le fait qu’il persiste à considérer l’informatique comme une technologie et non comme vecteur d’une mutation anthropologique.
Liens d’attachement : une autre perspective pour une autre culture. Étude exploratoire sur des enfants libanais
Authors: Nahas Nayla
Published: June 2020

Cet article s’interroge sur la validité et les limites de l’utilisation des théories et des outils d’évaluation des liens d’attachement développés dans des contextes américains et européens pour l’évaluation de la qualité de l’attachement dans d’autres cultures comme celle du Moyen-Orient. Il présente une étude exploratoire d’un outil de mesure de l’attachement, les Cartes de modèles individuels de relations (CaMir) sur un échantillon d’enfants libanais (N = 410) parlant la langue arabe. L’analyse factorielle en composante principale sur une version simplifiée (37 items) du CaMir a permis de trouver des catégories d’attachement proches de celles développées par la théorie de l’attachement mais leur expression se trouve être nuancée en fonction de la culture examinée. Cet article discute de la relation entre l’attachement et le mode d’interaction sociale caractérisé par la connectivité relationnelle.
Comportements de désinhibition sociale et d’attachement d’enfants d’âge préscolaire consultant en pédo-psychiatrie
Authors: Delbarre Marthe , Dubois-Comtois Karine , Achim Julie , Lebel Alain
Published: June 2020

Contexte  : Les études récentes ont contribué à distinguer les comportements de désinhibition du contact social (CDCS) du concept d’attachement. Certains auteurs, en s’appuyant sur de rares études qui ont observé une corrélation entre les CDCS et l’attachement insécure chez de jeunes enfants, soutiennent qu’il pourrait tout de même exister une association entre les deux, notamment lors de la constitution des premiers liens avec la mère. À ce jour, très peu d’études ont examiné cette association chez des enfants vivant avec leur mère biologique et aucune auprès d’enfants issus d’un échantillon pédopsychiatrique. Objectif : Le but de cette étude exploratoire est d’examiner s’il existe un lien entre l’attachement mère-enfant de type insécure et la présence de CDCS chez des enfants consultant en service de pédopsychiatrie. Méthode : Vingt-neuf enfants (âgés entre 23 et 71 mois) et leur mère ont participé à l’étude. Les CDCS et l’attachement mère-enfant ont été examinés lors d’une procédure de séparations et de réunions avec la présence d’une étrangère. Résultats : Plus les scores de CDCS sont élevés chez les enfants, plus leurs comportements d’attachement sont de type désorganisé/contrôlant et moins ils présentent des comportements d’attachement de type sécure. Conclusion : Ces résultats sont en accord avec ceux d’études antérieures qui avaient montré l’existence d’un lien significatif entre l’attachement mère-enfant de type insécure et la présence de CDCS chez de jeunes enfants vivant dans des milieux à risque psychosocial élevé.
Cash Holdings and the Selection Effect in the Eurozone
Authors: Dupuy Philippe , Albouy Michel , Bonnet Christophe , Mchawrab Safwan
Published: June 2020

Nous mettons en évidence un accroissement des liquidités moyennes détenues par les sociétés cotées de l’Eurozone entre 1986 et 2015. Cet accroissement est principalement dû à un saut significatif à la fin des années 1990 lié à une modification soudaine de la population des sociétés cotées (effet de sélection). Nous observons notamment une augmentation de la proportion de firmes intensives en R&D, dotées de fortes perspectives de croissance et fortement détentrices de liquidités. La plupart de ces entreprises appartiennent aux secteurs de la santé et de la technologie et semblent avoir bénéficié de conditions favorables d’introduction en bourse durant cette période. Ni les changements des caractéristiques des entreprises, ni ceux de leurs politiques de trésorerie, n’expliquent de façon significative la tendance observée (absence d’effet intra-population). Les différences de niveaux de liquidités moyens entre pays de l’Eurozone sont principalement expliquées par les différences de proportions de firmes intensives en R&D, et non par les différences d’environnements juridiques ou financiers.
The Ups and Downs of European Real Estate Markets’ Integration
Authors: Carpantier Jean-François , Sapata Christelle
Published: June 2020

Les marchés immobiliers nationaux sont généralement considérés comme étant segmentés les uns des autres. Les avantages de la diversification internationale se sont avérés dans le passé plus importants dans l’immobilier que dans les marchés d’actions ou d’obligations. Les nouveaux développements en Europe (marché unique, union monétaire et coordination des politiques macroprudentielles depuis la crise) devraient renforcer l’intégration et réduire ces avantages. Nous étudions le degré d’intégration variable des marchés immobiliers européens sur la période 1971-2017 en estimant le pouvoir explicatif d’un modèle linéaire multifactoriel. Nous constatons que l’intégration a été relativement stable dans le temps, avec une augmentation temporaire au cours de la crise financière de 2008. Nous notons également que les dynamiques d’intégration révèlent une évolution mondiale plutôt qu’européenne, dès lors que l’intégration des marchés nationaux européens avec les facteurs non-européens suit la même trajectoire que l’intégration intra-européenne. Nous ne détectons pas non plus de grappes d’intégration régionales stables. La diversification internationale des investissements immobiliers reste bénéfique.
Premier secrétaire, informateur et intime serviteur. Denis Charpentier à la tête du cabinet privé du cardinal de Richelieu
Authors: Boyko Maxim
Published: June 2020

« Votre mémoire chargée des plus importants secrets du royaume » écrivait François Le Métel de Boisrobert dans une lettre, adressée à Denis Charpentier (v.1580-1647), premier secrétaire du cardinal de Richelieu. En effet, dans cette première moitié du xvii e  siècle, le titre de premier secrétaire faisait de son détenteur non seulement un scribe ou un copiste, mais également un intime, dont on se servait dans les affaires de confiance et secrètes. L’objectif de cet article est de dévoiler au lecteur le fonctionnement et l’organisation du cabinet privé de Richelieu ainsi que de lui montrer la place que Charpentier, l’un des doyens, y occupait. L’existence de sa correspondance personnelle permettra également de faire émerger d’autres fonctions exercées par Charpentier au service du cardinal-ministre.
Encadrement du crédit et contrôle bancaire dans les années 1970 : la résistance des banques nationales (1968-1980). L’exemple de la Société Générale
Authors: Mastin Jean-Luc
Published: June 2020

Les événements du printemps 1968 puis la crise économique remettent en question certaines formes de libéralisation en cours depuis 1966. Outil central de la politique monétaire, l’encadrement du crédit est rétabli, d’abord temporairement (novembre 1968-octobre 1970) puis définitivement (novembre 1972). Mais le durcissement de la contrainte suscite le développement des contestations, de la fraude et des stratégies de contournement, y compris de la part des banques nationales. À la Société Générale, un « encadrement interne » est l’alibi de l’affaiblissement puis du dévoiement du contrôle interne. Outre les manipulations comptables, les opérations illicites de « désencadrement » contribuent in fine à faire primer le marché sur la réglementation.
L’ afición au flamenco : une passion au carré
Authors: Riegler Anne-Sophie
Published: June 2020

L’objet de cet article est de chercher à dissiper le flou dont souffre le concept d’afición dans le champ du flamenco. L’une des raisons de ce flou est que le concept d’afición s’avère porteur des mêmes ambiguïtés que celui d’amateurisme. On commence alors par rappeler les deux thèses dominantes au sujet de l’afición : une première l’assimile à la passion, une deuxième en fait un mélange de passion et de respect. On montre cependant les limites communes à ces deux thèses : à savoir, un sensualisme qui réduit l’afición à un mode de relation exclusivement sensoriel, sensible et émotionnel au flamenco, et un purisme qui masque l’hybridité des pratiques. On en vient ensuite à recenser les quelques typologies qui ont pu être établies pour rendre compte de la réalité complexe et variée qu’est l’afición. Mais au constat relativiste auquel elles conduisent, on oppose finalement la construction d’une définition prototypique de l’afición. Celle-ci apparaît comme une tendance à éprouver la passion pour un art tendant à exprimer lui-même la passion, soit ce qu’on peut appeler une passion au carré.
Le haïku au Japon est-il une activité d’amateurs ?
Authors: Akiba Minami
Published: June 2020

Le haïku est une poésie japonaise de seulement 17 syllabes. Le Japon compterait 10 millions de haïkistes principalement non professionnels. Chacun compose des haïkus et les montre à des confrères en recherchant une reconnaissance. Mais est-il judicieux de qualifier le haïku d’activité d’amateurs ?
Le film de famille : une poétique de l’accident
Authors: Olcèse Rodolphe
Published: June 2020

À partir de l’examen d’un ensemble de films amateurs conservé à la Cinémathèque de Saint-Étienne, identifié sous le titre de « dépôt Gourbeyre », ce texte se propose d’établir quelques caractéristiques de ce qu’a pu être le film de famille pratiqué au moyen de caméras argentiques. Outre la disponibilité à l’acte de filmer que demandent les outils de prise de vue pellicule, la pratique du 8 mm relève d’une exposition à l’imprévu et à l’accident. Quelques exemples d’incidents sont examinés ici, qui relèvent soit de l’usage, soit du fonctionnement de la caméra, mais qui élaborent ensemble les contours d’une poétique de l’accident.
Du mourir de la statue aux procédés justes de l’oblitération : Levinas face à l’œuvre de Sosno
Authors: Del Mastro Cesare
Published: June 2020

Cet article se donne pour tâche d’étudier la manière dont l’exposition à l’art d’oblitération du sculpteur Sacha Sosno conduit Levinas à décrire les portées ontologique et éthique de la pratique de la rature appliquée à des sculptures archétypales de l’art classique : oblitération par le vide (découpe, percée, trouée) et oblitération par le plein (obtusion, enserrement). Quarante-deux ans après avoir considéré – dans « La réalité et son ombre » (1948) – que seule l’exégèse philosophique de l’art peut réintégrer l’œuvre dans le monde humain, Levinas reconnaît une prise de position éthique au sein même de la technique d’oblitération. En effet, dans De l’oblitération (1990), le philosophe affirme que les blessures infligées par la défaite des belles formes interrompent notre obstination inter-essée de persévérer dans l’être, révèlent la finitude et l’ambiguïté d’un visage à la fois visible et invisible, dénoncent les abus de la vie sociale, et suscitent la compassion et la responsabilité du spectateur.
L’incidence de l’inclusion financière sur la croissance économique au Congo
Authors: Kabikissa F. Jean Désiré
Published: June 2020

Les récentes crises financières ont relancé le débat sur les interactions entre la sphère financière et la sphère réelle. Aussi bien dans les pays développés qu’en développement, l’inclusion financière devient un enjeu majeur. Elle est perçue comme un véritable outil de développement économique et de lutte contre la pauvreté. L’analyse des interactions entre la sphère financière et la sphère réelle se trouve dès lors renouvelée. L’objet de cette étude est d’analyser l’incidence de l’inclusion financière sur la croissance économique au Congo, en s’appuyant sur le modèle AutoRegressive Distributed Lag (ARDL) et l’analyse descriptive. Il ressort de cette étude que l’inclusion financière a une influence significative et positive sur la croissance économique au Congo, notamment sur la croissance du Produit Intérieur Brut (PIB) hors pétrole.
Une estimation non paramétrique de la régression par la méthode du régressogramme avec application au taux de change dollar US - franc CFA
Authors: Samba Bruno
Published: June 2020

Cet article fournit une analyse de la prévision du taux de change en usant des données journalières couvant la période 02 janvier 2013-31 décembre 2016. La qualité des prévisions de divers modèles de type régressogramme, est investiguée sur la base des critères statistiques de qualité de la prévision, tels que les tests fondés sur le MAPE, le RMSE et le U de Theil. L’article documente l’évidence que le lissage par la moyenne mobile et par la droite mobile produit les meilleures performances que le lissage par la médiane mobile. Les résultats empiriques indiquent que la qualité des prévisions se détériore fortement à mesure que l’horizon temporel des prévisions s’allonge. L’environnement international, très difficile à prévoir, semble affecter les prévisions des horizons les plus éloignés.