Evidence of chaotic modes in the analysis of four delta Scuti stars

Since CoRoT observations unveiled the very low amplitude modes that form a flat plateau in the power spectrum structure of delta Scuti stars, the nature of this phenomenon, including the possibility of spurious signals due to the light curve analysis, has been a matter of long-standing scientific debate. We contribute to this debate by finding the structural parameters of a sample of four delta Scuti stars, CID 546, CID 3619, CID 8669, and KIC 5892969, and looking for a possible relation between these stars' structural parameters and their power spectrum structure. For the purposes of characterization, we developed a method of studying and analysing the power spectrum with high precision and have applied it to both CoRoT and Kepler light curves. We obtain the best estimates to date of these stars' structural parameters. Moreover, we observe that the power spectrum structure depends on the inclination, oblateness, and convective efficiency of each star. Our results suggest that the power spectrum structure is real and is possibly formed by 2-period island modes and chaotic modes

Total Roman Domination Number of Rooted Product Graphs

[EN] Let G be a graph with no isolated vertex and f:V(G)->{0,1,2} a function. If f satisfies that every vertex in the set {v is an element of V(G):f(v)=0} is adjacent to at least one vertex in the set {v is an element of V(G):f(v)=2}, and if the subgraph induced by the set {v is an element of V(G):f(v)>= 1} has no isolated vertex, then we say that f is a total Roman dominating function on G. The minimum weight omega(f)= n-ary sumation v is an element of V(G)f(v) among all total Roman dominating functions f on G is the total Roman domination number of G. In this article we study this parameter for the rooted product graphs. Specifically, we obtain closed formulas and tight bounds for the total Roman domination number of rooted product graphs in terms of domination invariants of the factor graphs involved in this product.Cabrera Martinez, A.; Cabrera García, S.; Carrión García, A.; Hernandez Mira, FA. (2020). Total Roman Domination Number of Rooted Product Graphs. Mathematics. 8(10):1-13. https://doi.org/10.3390/math8101850S11381

Rubidium-Rich Asymptotic Giant Branch Stars

A long debated issue concerning the nucleosynthesis of neutron-rich elements in Asymptotic Giant Branch (AGB) stars is the identification of the neutron source. We report intermediate-mass (4 to 8 solar masses) AGB stars in our Galaxy that are rubidium-rich owing to overproduction of the long-lived radioactive isotope 87Rb, as predicted theoretically 40 years ago. This represents a direct observational evidence that the 22Ne(alpha,n)25Mg reaction must be the dominant neutron source in these stars. These stars then challenge our understanding of the late stages of the evolution of intermediate-mass stars and would promote a highly variable Rb/Sr environment in the early solar nebula

Leveraging the Power of Mutual Aid, Coalitions, Leadership, and Advocacy during COVID-19

The COVID-19 pandemic has shed light on the norms, patterns, and power structures in the United States that privilege certain groups of people over others. This manuscript describes COVID-19 as an unprecedented catalyst for social transformation that underscores the need for multi-level and cross-sectoral solutions to address systemic changes to improve health equity for all. The authors propose that the American Psychological Association and its membership can initiate systemic change, in part, by: (a) supporting mutual aid organizations that prioritize the needs of vulnerable communities; (b) leveraging the efforts and strides APA psychologists have already made within the association, in the profession, and in policymaking to attend to the health equity and the needs of marginalized communities; (c) building capacity for collaboration between a broad coalition of health associations, health experts, and policymakers to address the physio-psycho-socioeconomic needs of disadvantaged communities, and (d) increasing APA’s participation in the formulation and implementation of an advocacy agenda that prioritizes the physical and psychological health of the communities whose lives are most endangered by COVID-19. Public Significance Statement. Our article aims to emphasize the important role that social determinants of health play for marginalized communities. It has the potential to inform health professionals, including psychologists, about support and advocacy strategies that seek to improve health equity during and after the COVID-19 pandemic is contained

Lithium and zirconium abundances in massive Galactic O-rich AGB stars

Lithium and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which high resolution optical spectroscopy has been obtained (R=40,000-50,000). This is done by computing synthetic spectra based on classical hydrostatic model atmospheres for cool stars using extensive line lists. The results obtained are discussed in the framework of hot bottom burning (HBB) and nucleosynthesis models. The complete sample is studied attending to various observational properties such as the position of the stars in the IRAS two-colour diagram ([12]-[25] vs [25]-[60]), Galactic distribution, expansion velocity (derived from the OH maser emission) and period of variability (when available). We conclude that a considerable fraction of the sources observed are actually massive AGB stars (M > 3-4 solar masses) experiencing HBB, as deduced from the strong Li overabundances found. A comparison of our results with similar studies carried out in the past for the Magellanic Clouds (MCs) reveals that, in contrast to MC AGB stars, our Galactic sample does not show any indication of s-process element enrichment. The differences observed are explained as a consequence of metallicity effects. Finally, we discuss the results obtained in the framework of stellar evolution by comparing our results with the data available in the literature for Galactic post-AGB stars and PNe

The neglect of herself in the process of Infatuation–Love

La presente investigación, de corte cualitativo, tiene como objetivo describir la forma como se vive el proceso de Enamoramiento-Amor en una población de mujeres universitarias del Estado de México. Se desarrolló en dos momentos, primero mediante la técnica de Redes Semánticas se indagó sobre lo que conciben como amor, enamoramiento y manifestaciones de éstos. A partir de estos resultados, se eligió a las informantes clave; a quienes en un segundo momento se aplicó una entrevista semiestructurada, que profundiza en los conocimientos, comportamiento y el tipo de emociones que se viven en el proceso de Enamoramiento-Amor. Los hallazgos muestran que las mujeres universitarias en el proceso de Enamoramiento parten de la idealización del otro, no perciben sus defectos o bien se toleran; el comportamiento que se asume se encuentra ligado al deber ser del amor, donde todo es justificado y perdonado en nombre de este sentimiento. En la etapa de amor, se presentan conductas de protección y cuidado hacia el otro, dejando en último las propias necesidades. Las informantes señalan que en el amor se generan sentimientos ambivalentes de extrema felicidad y sufrimiento al tener que tolerar violencia física y psicológica por parte de la pareja, esto coincide con la concepción de Fromm acerca del amor como fundamental en el ser humano, donde se debe aprender y ejercitar poniendo en juego toda la personalidad, implica asumir una actitud positiva, una orientación de carácter, un acto de voluntad y compromiso hacía el otro; aunque en este caso no sea recíproco

Quantum Magnetic Deflagration in Mn12 Acetate

We report controlled ignition of magnetization reversal avalanches by surface acoustic waves in a single crystal of Mn12 acetate. Our data show that the speed of the avalanche exhibits maxima on the magnetic field at the tunneling resonances of Mn12. Combined with the evidence of magnetic deflagration in Mn12 acetate (Suzuki et al., cond-mat/0506569) this suggests a novel physical phenomenon: deflagration assisted by quantum tunneling.Comment: 4 figure

Low temperature microwave emission from molecular clusters

We investigate the experimental detection of the electromagnetic radiation generated in the fast magnetization reversal in Mn12-acetate at low temperatures. In our experiments we used large single crystals and assemblies of several small single crystals of Mn12-acetate placed inside a cylindrical stainless steel waveguide in which an InSb hot electron device was also placed to detect the radiation. All this was set inside a SQUID magnetometer that allowed to change the magnetic field and measure the magnetic moment and the temperature of the sample as the InSb detected simultaneously the radiation emitted from the molecular magnets. Our data show a sequential process in which the fast inversion of the magnetic moment first occurs, then the radiation is detected by the InSb device, and finally the temperature of the sample increases during 15 ms to subsequently recover its original value in several hundreds of milliseconds.Comment: changed conten

Experimental Evaluation of Transmitted Signal Distortion Caused by Power Allocation in Inter-Cell Interference Coordination Techniques for LTE/LTE-A and 5G Systems

Error vector magnitude (EVM) and out-of-band emissions are key metrics for evaluating in-band and out-band distortions introduced by all potential non-idealities in the transmitters of wireless systems. As EVM is a measure of the quality of the modulated signal/symbols, LTE/LTE-A and 5G systems specify mandatory EVM requirements in transmission for each modulation scheme. This paper analyzes the influence of the mandatory satisfaction of EVM requirements on the design of radio resource management strategies (RRM) (link adaptation, inter-cell interference coordination), specifically in the downlink (DL). EVM depends on the non-idealities of the transmitter implementations, on the allocated power variations between the subcarriers and on the selected modulations. In the DL of LTE, link adaptation is usually executed by adaptive modulation and coding (AMC) instead of power control, but some flexibility in power allocation remains being used. LTE specifies some limits in the power dynamic ranges depending on the allocated modulation, which ensures the satisfaction of EVM requirements. However, the required recommendations concerning the allowed power dynamic range when inter-cell interference coordination (ICIC) and enhanced ICIC (eICIC) mechanisms (through power coordination) are out of specification, even though the EVM performance should be known to obtain the maximum benefit of these strategies. We perform an experimental characterization of the EVM in the DL under real and widely known ICIC implementation schemes. These studies demonstrate that an accurate analysis of EVM is required. It allows a better adjustment of the design parameters of these strategies, and also allows the redefinition of the main criteria to be considered in the implementation of the scheduler/link adaptation concerning the allocable modulation coding scheme (MCS) in each resource block. © 2013 IEEE