Self-sustained spatiotemporal oscillations induced by membrane-bulk coupling

We propose a novel mechanism leading to spatiotemporal oscillations in extended systems that does not rely on local bulk instabilities. Instead, oscillations arise from the interaction of two subsystems of different spatial dimensionality. Specifically, we show that coupling a passive diffusive bulk of dimension d with an excitable membrane of dimension d-1 produces a self-sustained oscillatory behavior. An analytical explanation of the phenomenon is provided for d=1. Moreover, in-phase and anti-phase synchronization of oscillations are found numerically in one and two dimensions. This novel dynamic instability could be used by biological systems such as cells, where the dynamics on the cellular membrane is necessarily different from that of the cytoplasmic bulk.Comment: Accepted for publication in Physical Review Letter

Galaxy evolution across the optical emission-line diagnostic diagrams?

The discovery of the M-sigma relation, the local galaxy bimodality, and the link between black-hole and host-galaxy properties, have raised the question whether AGN play a role in galaxy evolution. Several theoretical models implement AGN feedback to explain the observed galaxy luminosity function, and possibly the color and morphological transformation of spiral galaxies into passive ellipticals. To understand the importance of AGN feedback, a study of the AGN populations in the radio-optical domain is crucial. A mass sequence linking star-forming galaxies and AGN has been already noted in previous works, and it is now investigated as possible evolutionary sequence. We observed a sample of 119 intermediate-redshift (0.04<z<0.4) SDSS-FIRST radio emitters with the Effelsberg 100-m telescope at 4.85 and 10.45 GHz and obtained spectral indices. We find indications of spectral index flattening in high-metallicity star-forming galaxies, composite galaxies, and Seyferts. This "flattening sequence" along the [NII]-based emission-line diagnostic diagram is consistent with the hardening of galaxy ionizing field, due to nuclear activity. After combining our data with FIRST measurements at 1.4 GHz, we find that the three-point radio spectra of Seyferts and LINERs show substantial differences, attributable to small radio core components and larger (arcsecond sized) jet/lobe components, respectively. A visual inspection of FIRST images seems to confirm this hypothesis. Galaxies along this sequence are hypothesized to be transitioning from the active star-forming galaxies (blue cloud) to the passive elliptical galaxies (red sequence). This supports the suggestion that AGN play a role in shutting down star-formation, and allow the transition from one galaxy class to the other.Comment: 20 pages, 19 figures, accepted for publication in A&

A low-luminosity type-1 QSO sample; III. Optical spectroscopic properties and activity classification

We report on the optical spectroscopic analysis of a sample of 99 low-luminosity quasi-stellar objects (LLQSOs) at $z\leq 0.06$ base the Hamburg/ESO QSO survey (HES). The LLQSOs presented here offer the possibility of studying the faint end of the QSO population at smaller cosmological distances and, therefore, in greater detail. A small number of our LLQSO present no broad component. Two sources show double broad components, whereas six comply with the classic NLS1 requirements. As expected in NLR of broad line AGNs, the [S{\sc{ii}}]$-$based electron density values range between 100 and 1000 N$_{e}$/cm$^{3}$. Using the optical characteristics of Populations A and B, we find that 50\% of our sources with H$\beta$ broad emission are consistent with the radio-quiet sources definition. The remaining sources could be interpreted as low-luminosity radio-loud quasar. The BPT-based classification renders an AGN/Seyfert activity between 50 to 60\%. For the remaining sources, the possible star burst contribution might control the LINER and HII classification. Finally, we discuss the aperture effect as responsible for the differences found between data sets, although variability in the BLR could play a significant role as well.Comment: 22 pages; 5 tables; 17 figures; in press with A&

Protocol: Triple Diamond method for problem solving and design thinking. Rubric validation

[EN] There is a set of tools that we can use to improve the results of each of the phases that continuous improvement projects must go through (8D, PDCA, DMAIC, Double diamond, etc.). These methods use divergent techniques, which help generate multiple alternatives, and convergent techniques that help analyze and filter the generated options. However, the tools used in all those frameworks are often very similar. Our goal, in this research, is to develop a comprehensive model that allows it to be used both for problem-solving and for taking advantage of opportunities. This protocol defines the main terms related to our research, makes a framework proposal, proposes a rubric that identifies observable milestones at each stage of the model and proposes the action plan to validate this rubric and the model in a given context. The action plan will be implemented in a future research.Marin-Garcia, JA.; Garcia-Sabater, JJ.; Garcia-Sabater, JP.; Maheut, J. (2020). Protocol: Triple Diamond method for problem solving and design thinking. Rubric validation. WPOM-Working Papers on Operations Management. 11(2):49-68. https://doi.org/10.4995/wpom.v11i2.14776OJS496811

Gamification of participatory modeling in the context of sustainable development: existing and new solutions

Serious games and gamification tools have gradually expanded their application in participatory settings, while already being widely used in the context of sustainable development in general. Their popularity is explained by their ability to create an engaging and experimental environment, which evokes critical thought, meaningful interaction between the participants and experience-based learning. Although game design principles and tools are, to a large extent, universal, their application differs from one field to another. The simulation modelling field has a long history of using game elements to make complicated models more user-friendly and understandable for wider audiences. Management flight simulators, microworlds, policy exercises and strategic simulations are among the most common examples. Meanwhile, the urban planning field often makes use of interactive 3D maps, including the most recent advancements in applying XR technologies to make the interaction with the system more tactile and collaborative in a multi- user setting. Serious games are used in participatory projects as a supplementary approach to provoking discussion among the stakeholders and stimulating critical thinking. Gamification in the participatory modeling field is commonly used at the initial and final stages of the process or by incorporating a role playing component into the process (e.g. in companion modeling and social simulations). Based on the existing research, we have two main observations: (1) in each of the above-mentioned fields there are traditional ways of using gamification and visualization instruments and there is a lack of ‘cross-pollination’ between various application fields in terms of choosing gamification tools, (2) gamification tools are commonly used at one or two stages of participatory modeling process but rarely over the entire process of participatory modeling. We suggest that by introducing more gamification elements throughout the whole PM process we can produce a more gameful or, at least, a more engaging experience for stakeholders. As a preliminary step towards wider use of gamification in the participatory modeling process, we first analyze how existing gaming solutions from various fields can be applied in the context of different stages of participatory modeling. In our research we critically reviewed the use of gamification from two perspectives: (1) to which extent it could help to mitigate the challenges of participatory modeling process (e.g. biases, groupthink, conflicts, etc.) and consequently contribute to better learning and communication between the participants, (2) how it could contribute to the creation of engaging experiences for the participants during participatory modeling process. As a result, we propose a framework for gamification of each stage of the participatory modeling process taking into consideration the already existing solutions, as well as the insights from the game design and behavioral science fields

How to reduce the number of rating scale items without predictability loss?

Rating scales are used to elicit data about qualitative entities (e.g., research collaboration). This study presents an innovative method for reducing the number of rating scale items without the predictability loss. The "area under the receiver operator curve method" (AUC ROC) is used. The presented method has reduced the number of rating scale items (variables) to 28.57\% (from 21 to 6) making over 70\% of collected data unnecessary. Results have been verified by two methods of analysis: Graded Response Model (GRM) and Confirmatory Factor Analysis (CFA). GRM revealed that the new method differentiates observations of high and middle scores. CFA proved that the reliability of the rating scale has not deteriorated by the scale item reduction. Both statistical analysis evidenced usefulness of the AUC ROC reduction method.Comment: 14 pages, 5 figure

Towards optimisation of surface enhanced photodynamic therapy of breast cancer cells using gold nanoparticle-photosensitiser conjugates

Gold nanoparticles (AuNPs; ca. 4 nm) were synthesised and functionalised with a mixed monolayer of polyethylene glycol (PEG) and one of two zinc phthalocyanines (ZnPcs), the difference between the two molecules was the length of the carbon chain that connects the Pc to the gold core. The chain was composed of either three (C3Pc) or eleven (C11Pc) carbon atoms. The C11Pc photosensitiser displayed higher fluorescence emission intensity than the C3Pc in solution. By contrast, the C3Pc photosensitiser exhibited higher fluorescence when bound to the surface of the AuNPs than the C11Pc, despite the shorter carbon chain which was expected to quench the fluorescence. In addition, the C3Pc nanoparticle conjugates exhibited an enhancement in the production of singlet oxygen (1O2). The metal-enhanced 1O2 production led to a remarkable photodynamic efficacy for the treatment of human breast cancer cells

The Galactic centre mini-spiral in the mm-regime

The mini-spiral is a feature of the interstellar medium in the central ~2 pc of the Galactic center. It is composed of several streamers of dust and ionised and atomic gas with temperatures between a few 100 K to 10^4 K. There is evidence that these streamers are related to the so-called circumnuclear disk of molecular gas and are ionized by photons from massive, hot stars in the central parsec. We attempt to constrain the emission mechanisms and physical properties of the ionized gas and dust of the mini-spiral region with the help of our multiwavelength data sets. Our observations were carried out at 1.3 mm and 3 mm with the mm interferometric array CARMA in California in March and April 2009, with the MIR instrument VISIR at ESO's VLT in June 2006, and the NIR Br-gamma with VLT NACO in August 2009. We present high resolution maps of the mini-spiral, and obtain a spectral index of 0.5 for Sgr A*, indicating an inverted synchrotron spectrum. We find electron densities within the range 0.8-1.5x10^4 cm-3 for the mini-spiral from the radio continuum maps, along with a dust mass contribution of ~0.25 solar masses from the MIR dust continuum, and extinctions ranging from 1.8-3 at 2.16 micron in the Br-gamma line. We observe a mixture of negative and positive spectral indices in our 1.3 mm and 3 mm observations of the extended emission of the mini-spiral, which we interpret as evidence that there are a range of contributions to the thermal free-free emission by the ionized gas emission and by dust at 1.3 mm.Comment: 9 pages, 11 figures, accepted to A&

Comparación del efecto de diferentes modosde agregar las calificaciones de evaluación continua en la nota final

[EN] We present the results of comparing various ways of calculating students' final grades from continuous assessment grades. Traditionally the weighted arithmetic mean has been used and we compare this method with other alternatives: arithmetic mean, geometric mean, harmonic mean and multiplication of the percentage of overcoming of each activi-ty. Our objective is to verify, if any of the alternative methods, agree with the student’s performance proposed by the teacher of the subject, further discriminating the grade be-tween high and low learning outcomes and reducing the number of approved opportunists.Este trabajo ha sido parcialmente financiado por la Universitat Politécnica de Valencia (PIME/2016/A/027/A) “La evaluación pareada como metodología para la evaluación del pensamiento crí- tico de los alumnos”.Marin-Garcia, JA.; Maheut, J.; Garcia Sabater, JJ. (2017). Comparison of different ways of computing grades in continuous assessment into the final grade. Working Papers on Operations Management. 8(SP):1-12. https://doi.org/10.4995/wpom.v8i0.72421128S