Constraints on the formation mechanism of the planetary mass companion of 2MASS 1207334-393254

In this paper we discuss the nature and the possible formation scenarios of the companion of the brown dwarf 2MASS 1207334-393254. We initially discuss the basic physical properties of this object and conclude that, although from its absolute mass ($5M_{\rm Jup}$), it is a planetary object, in terms of its mass ratio $q$ and of its separation $a$ with respect to the primary brown dwarf, it is consistent with the statistical properties of binaries with higher primary mass. We then explore the possible formation mechanism for this object. We show that the standard planet formation mechanism of core accretion is far too slow to form this object within 10 Myr, the observed age of the system. On the other hand, the alternative mechanism of gravitational instability (proposed both in the context of planet and of binary formation) may, in principle, work and form a system with the observed properties.Comment: 5 pages, MNRAS in pres

Maximizing Beneficence and Autonomy: Ethical Support for the Use of Non-Pharmacological Methods for Managing Dental Anxiety

This article examines advantages associated with nonpharmacological behavioral management techniques and suggests that there are benefits to their use (such as achieving a more lasting solution to the problem of dental anxiety) that are not realized with medication-based interventions. Analyses that use Kantian and existential viewpoints for exploring the use of medication versus behavioral interventions for managing life problems yield parallel conclusions: there are advantages gained by using behavioral interventions that are not always associated with medicationbased interventions. These analyses, taken together with an understanding of the psychology of dental anxiety management, suggest that using nonpharmacological techniques for the management of dental anxiety can maximize adherence-to the ethical principles of beneficence and patient autonomy. The authors discuss the barriers that make nonpharmacological interventions for anxiety management difficult for dentists to routinely use, and suggest that additional training in these methods and increased collaboration with mental health professionals are needed for dentists

Integracija društveno odgovornog poslovanja u strategiju tehnološki intenzivnih poduzeća: poslovni slučaj

This paper presents a new perspective which calls for an integration of ethics and corporate social responsibility (CSR) into the company strategy as a source of competitive advantages. The research question we pose is how a company can successfully carry out this integration of CSR into its strategic management, for which a model that includes three stages – introduction, implementation and generalization of CSR – is presented. Based on an exploratory case study within a Spanish technology-intensive firm (Indra), we show the way this company has developed and implemented an explicit plan for the integration of ethical values and CSR initiatives into its corporate and business strategies. Although this company has established its own methodology in order to develop and implement CSR plans, it fits in essence to our three-stage model of CSR integration. In general, our analyses show a beneficial impact of the development and implementation of CSR plan for this technology-intensive company. In particular, it seems that the CSR plan enables companies to improve its’ internal and external (competitive) context through a better exploration and exploitation of knowledge, its stable relationships with stakeholders and the development and improvement of intangible resources such as reputation or social capital. It is also shown that there are important factors to consider in order this process can successfully carried out, such as organizational culture, human resource practices or knowledge management systems. Future research will need to engage in largerscale confirmatory as well as longitudinal studies of the impact of CSR implementation for company performance.U radu je predstavljena nova perspektiva koja integraciju etičkog i društveno odgovornog poslovanja u strategiju poduzeća smatra izvorom konkurentskih prednosti. Postavljeno je istraživačko pitanje koje nastoji utvrditi na koji način poduzeće može uspješno provesti integraciju društveno-odgovornog poslovanja u strateški menadžment i u tu svrhu predstavljen je model koji uključuje tri faze: uvod, implementaciju i generalizaciju društveno-odgovornog poslovanja. Na temelju eksplorativne analize slučaja procesa strateškog oblikovanja unutar tehnološko intenzivnog poduzeća u Španjolskoj (Indra), prikazan je eksplicitan plan integracije etičkih vrijednosti i inicijativa društveno odgovornog poslovanja u njegovu korporativnu i pripadajuće poslovne strategije. Iako je ovo poduzeće uspostavilo svoju metodologiju za provođenje i razvoj planova društveno odgovornog poslovanja, ono se u biti uklapa u naš model integracije u tri faze. Općenito, provedene analize prikazuju pozitivan utjecaj razvoja i implementacije plana društveno odgovornog poslovanja na promatrano tehnološko intenzivno poduzeće. Posebice, čini se kako plan društveno odgovornog poslovanja, kroz bolje istraživanje i iskorištavanje znanja te kroz postojanje stabilnih odnosa s interesno-utjecajnim skupinama, omogućava poduzećima unaprjeđenje njihovog unutarnjeg i vanjskog (konkurentskog) okruženja. Kako bi se to potvrdilo, u budućnosti su potrebna opsežnija konfirmativna, ali i longitudinalna istraživanja utjecaja implementacije društveno odgovornog poslovanja na uspješnost poduzeća

Learning Analytics in K-12 Spanish education: a systematic mapping study

Learning analytics processes have an increased relevance in the digitization and virtualization of learning and teaching due to COVID-19, this analytical practice may mean improvements in K-12 levels in Spain. The work aims to expose the principal scientific publications regarding Learning analytics at these educational levels through a systematic mapping study. The authors set the hypothesis that there is limited research in such an educational context. Results validate the hypothesis and foster to continue the work through a deeper systematic review

The dependence of the sub-stellar IMF on the initial conditions for star formation

Abridged: We have undertaken a series of hydrodynamical simulations of multiple star formation in small turbulent molecular clouds. Our goal is to determine the sensitivity of the properties of the resulting stars and brown dwarfs to variations in the initial conditions imposed. In this paper we report on the results obtained by applying two different initial turbulent velocity fields. The slope of the turbulent power-law spectrum alpha is set to -3 in half of the calculations and to -5 in the other half. We find that, whereas the stellar mass function seems to only be weakly dependent on the value of alpha, the sub-stellar mass function turns out to be more sensitive to the initial slope of the velocity field. We argue that, since the role of turbulence is to create substructure from which gravitational instabilities may grow, variations in other initial conditions that also determine the fragmentation process are likely to affect the shape of the sub-stellar mass function as well. The absence of many planetary mass `free-floaters' in our simulations, especially in the mass range 1-10 MJ, suggests that, if these objects are abundant, they are likely to form by similar mechanisms to those thought to operate in quiescent accretion discs, instead of via instabilities in gravitationally unstable discs. Finally, we find that multiple and single stars share comparable kinematical properties, both populations being able to attain velocities in the range 1-10 km/s. From these values we draw the conclusion that only low-mass star-forming regions such as Taurus-Auriga or Ophiuchus, where the escape speed is low, might have suffered some depletion of its single and binary stellar population.Comment: 13 pages, 6 figures, accepted by MNRA

The 0.03-10Mo mass function of young open clusters

We report the present day mass functions (PDMFs) of 3 young open clusters over a mass range from 30 Jupiter masses to 10~\msunn. The PDMFs of the 3 clusters are remarkably similar, suggesting little impact of specific conditions (stellar density, metallicity, early dynamical evolution) on the mass distribution. Functional forms are provided to allow quantitative comparison with MFs derived in other environments.Comment: 6 pages, to appear in "IMF@50", Corbelli, Palla, Zinnecker ed

Evaluation of Aloe Vera Coated Polylactic Acid Scaffolds for Bone Tissue Engineering

3D-printed polylactic acid (PLA) scaffolds have been demonstrated as being a promising tool for the development of tissue-engineered replacements of bone. However, this material lacks a suitable surface chemistry to efficiently interact with extracellular proteins and, consequently, to integrate into the surrounding tissue when implanted in vivo. In this study, aloe vera coatings have been proposed as a strategy to improve the bioaffinity of this type of structures. Aloe vera coatings were applied at three different values of pH (3, 4 and 5), after treating the surface of the PLA scaffolds with oxygen plasma. The surface modification of the material has been assessed through X-ray photoelectron spectroscopy (XPS) analysis and water contact angle measurements. In addition, the evaluation of the enzymatic degradation of the structures showed that the pH of the aloe vera extracts used as coating influences the degradation rate of the PLA-based scaffolds. Finally, the cell metabolic activity of an in vitro culture of human fetal osteoblastic cells on the samples revealed an improvement of this parameter on aloe vera coated samples, especially for those treated at pH 3. Hence, these structures showed potential for being applied for bone tissue regeneration

A Hubble Space Telescope ACS Search for Brown Dwarf Binaries in the Pleiades Open Cluster

We present the results of a high-resolution imaging survey for brown dwarf binaries in the Pleiades open cluster. The observations were carried out with the Advance Camera for Surveys onboard the Hubble Space Telescope. Our sample consists of 15 bona-fide brown dwarfs. We confirm 2 binaries and detect their orbital motion, but we did not resolve any new binary candidates in the separation range between 5.4AU and 1700AU and masses in the range 0.035--0.065~Msun. Together with the results of our previous study (Martin et al., 2003), we can derive a visual binary frequency of 13.3$^{+13.7}_{-4.3}$\% for separations greater than 7~AU masses between 0.055--0.065~M_{\sun} and mass ratios between 0.45--0.9$<q<$1.0. The other observed properties of Pleiades brown dwarf binaries (distributions of separation and mass ratio) appear to be similar to their older counterparts in the field.Comment: 29 pages, 7 figures, 6 tables, accepted for publication in Ap

Multiple protostellar systems. I. A deep near infrared survey of Taurus and Ophiuchus protostellar objects

(Abridged) We performed a deep infrared imaging survey of 63 embedded young stellar objects (YSOs) located in the Taurus and Ophiuchus clouds to search for companions. The sample includes Class I and flat infrared spectrum protostellar objects. We find 17 companions physically bound to 15 YSOs with angular separations in the range 0.8-10" (110-1400 AU) and derive a companion star fraction of 23+/-9 % and 29+/-7 % for embedded YSOs in Taurus and Ophiuchus, respectively. In spite of different properties of the clouds and especially of the prestellar cores, the fraction of wide companions, 27+/-6 % for the combined sample, is identical in the two star-forming regions. This suggests that the frequency and properties of wide multiple protostellar systems are not very sensitive to specific initial conditions. Comparing the companion star fraction of the youngest YSOs still surrounded by extended envelopes to that of more evolved YSOs, we find evidence for a possible evolution of the fraction of wide multiple systems, which seems to decrease by a factor of about 2 on a timescale of about 10^5 yr. Somewhat contrary to model predictions, we do not find evidence for a sub-clustering of embedded sources at this stage on a scale of a few 100 AU that could be related to the formation of small-N protostellar clusters. Possible interpretations for this discrepancy are discussed.Comment: Accepted for publication in Astronomy & Astrophysics; 16 pages, 3 embedded figures, 1 JPEG figur