Global Patterns of Synchronization in Human Communications

Social media are transforming global communication and coordination. The data derived from social media can reveal patterns of human behavior at all levels and scales of society. Using geolocated Twitter data, we have quantified collective behaviors across multiple scales, ranging from the commutes of individuals, to the daily pulse of 50 major urban areas and global patterns of human coordination. Human activity and mobility patterns manifest the synchrony required for contingency of actions between individuals. Urban areas show regular cycles of contraction and expansion that resembles heartbeats linked primarily to social rather than natural cycles. Business hours and circadian rhythms influence daily cycles of work, recreation, and sleep. Different urban areas have characteristic signatures of daily collective activities. The differences are consistent with a new emergent global synchrony that couples behavior in distant regions across the world. A globally synchronized peak that includes exchange of ideas and information across Europe, Africa, Asia and Australasia. We propose a dynamical model to explain the emergence of global synchrony in the context of increasing global communication and reproduce the observed behavior. The collective patterns we observe show how social interactions lead to interdependence of behavior manifest in the synchronization of communication. The creation and maintenance of temporally sensitive social relationships results in the emergence of complexity of the larger scale behavior of the social system.Comment: 20 pages, 12 figures. arXiv admin note: substantial text overlap with arXiv:1602.0621

IMF shape constraints from stellar populations and dynamics from CALIFA

M. Lyubenova et. al.In this paper, we describe how we use stellar dynamics information to constrain the shape of the stellar initial mass function (IMF) in a sample of 27 early-type galaxies from the CALIFA survey. We obtain dynamical and stellar mass-to-light ratios, ¿dyn and ¿*, over a homogenous aperture of 0.5 Re. We use the constraint ¿dyn¿¿* to test two IMF shapes within the framework of the extended MILES stellar population models. We rule out a single power-law IMF shape for 75 per cent of the galaxies in our sample. Conversely, we find that a double power-law IMF shape with a varying high-mass end slope is compatible (within 1¿) with 95 per cent of the galaxies. We also show that dynamical and stellar IMF mismatch factors give consistent results for the systematic variation of the IMF in these galaxies. © 2016, Published by Oxford University Press on behalf of the Royal Astronomical Society.This Paper is based on data obtained by the CALIFA survey, funded by the Spanish Ministry of Science under grant ICTS-2009-10, and the CAHA. IMN and JFB acknowledge funding from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO) and, together with and GvdV, from the FP7 Marie Curie Actions via the ITN DAGAL (grant 289313). CJW acknowledges support through the Marie Curie Career Integration Grant 303912. Support for LG is provided by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009 awarded to The Millennium Institute of Astrophysics (MAS), and CONICYT through FONDECYT grant 3140566. RGD acknowledges support from AyA2014-57490-P. JMA acknowledges support from the ERC Starting Grant (SEDmorph; P.I. V. Wild).Peer Reviewe

Influence of external driving on decays in the geometry of the LiCN isomerization

The framework of transition state theory relies on the determination of a geometric structure identifying reactivity. It replaces the laborious exercise of following many trajectories for a long time to provide chemical reaction rates and pathways. In this paper, recent advances in constructing this geometry even in time-dependent systems are applied to the LiCN $\rightleftharpoons$ LiNC isomerization reaction, driven by an external field. We obtain decay rates of the reactant population close to the transition state by exploiting local properties of the dynamics of trajectories in and close to it. We find that the external driving has a large influence on these decay rates when compared to the non-driven isomerization reaction. This, in turn, provides renewed evidence for the possibility of controlling chemical reactions, like this one, through external time-dependent fields.Comment: Main article has 11 pages, 6 figures. Supplemental material has 4 pages, 1 figur

Nueva medida y umbrales para la desigualdad y su relación con la conflictividad

This paper develops an alternative methodology to analyze income inequality and its structure. The proposed approach allows us, among other things, to classify individuals into income groups endogenously. This classification of income groups will be used to study the structure of inequality and to find a relation between inequality and conflict and social unrest. This approach is applied to Spanish income data from the Income and Living Conditions survey (SILC) conducted by the INE. We refer to the years 2005, 2007, 2009 and 2011 with the aim of evaluating the impact of the economic crisis. The empirical results show an increase in inequality and a decrease in the share of total income of households classified as poor, lower middle class and middle class. On the contrary, the households located at the right end of the income distribution scale have improved. This fact leads to a more unstable society and one prone to conflict.En este trabajo se desarrolla una metodología alternativa para analizar la desigualdad de la renta y su estructura. El procedimiento que se propone permite, entre otros, clasificar a los individuos en grupos de renta de forma endógena. Los grupos de renta resultantes facilitan el estudio de la estructura de la desigualdad y a su vez permiten relacionar la desigualdad con la posible generación de conflicto. El procedimiento desarrollado se aplica a datos de renta de los hogares españoles procedentes de la Encuesta de Condiciones de Vida (ECV) elaborada y publicada por el Instituto Nacional de Estadística. Se han utilizado datos correspondientes a los años 2005, 2007, 2009 y 2011 con el objeto de evaluar los efectos de la crisis en términos de distribución de renta. Los resultados ponen de manifiesto la creciente desigualdad de la renta y la disminución en la participación en el total de la renta de los hogares catalogados como pobres, clase media baja y clase media en beneficio de los hogares mejor posicionados. Esta situación conlleva a sociedades más inestables y propensas al conflicto

Growth under laboratory conditions of wild juvenile black-spot sea bream (Pagellus bogaraveo B.)

As an alternative to the culture of traditional fish, experiments have been started with black-spot sea bream (Pagellus bogaraveo) and are summarized here. Two groups of bream (B-1 and B-2) with 63 fish of mean weight 173 g and 67fish of mean weight 217 g, respectively, were captured on the NW coast of Spain between September and December 1991, transported to the laboratory, and maintained in 12 m tanks. After about 30 days acclimation, lengths and weights of all fish were measured. These measurements were repeated at 2 month intervals,for 14 months in the first group and 10 months in the second. The mean weights reached at the end of these periods were 462 g and 383 s. respectively. Fish were fed with laboratory prepared moist food. and the amount eaten daily was controlled. Survival rate at the end of the experiment was 90.5% in group B-1 and95.5% in group B-2. Temperature, measured daily, ranged from 12ºC to 20°C. This paper provides information on the capture, transport, acclimation and maintenance of the fish throughout the experiment.Versión del editor0,000

Spatially Resolved Star Formation Main Sequence of Galaxies in the Califa Survey

Cano-Díaz, M. et. al.The >main sequence of galaxies> - defined in terms of the total star formation rate ψ versus the total stellar mass M - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log(M yr Kpc) and the stellar mass surface density in units of log(M Kpc) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequence.Financial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA-100815 projects. Z.S.: EU Marie Curie Career Integration Grant >SteMaGE> PCIG12-GA-2012-326466. Y.A.: RyC-2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014-57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013-48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 3140566.Peer Reviewe

Cannabidiol reduces lipopolysaccharide-induced vascular changes and inflammation in the mouse brain: an intravital microscopy study

<p>Abstract</p> <p>Background</p> <p>The phytocannabinoid cannabidiol (CBD) exhibits antioxidant and antiinflammatory properties. The present study was designed to explore its effects in a mouse model of sepsis-related encephalitis by intravenous administration of lipopolysaccharide (LPS).</p> <p>Methods</p> <p>Vascular responses of pial vessels were analyzed by intravital microscopy and inflammatory parameters measured by qRT-PCR.</p> <p>Results</p> <p>CBD prevented LPS-induced arteriolar and venular vasodilation as well as leukocyte margination. In addition, CBD abolished LPS-induced increases in tumor necrosis factor-alpha and cyclooxygenase-2 expression as measured by quantitative real time PCR. The expression of the inducible-nitric oxide synthase was also reduced by CBD. Finally, preservation of Blood Brain Barrier integrity was also associated to the treatment with CBD.</p> <p>Conclusions</p> <p>These data highlight the antiinflammatory and vascular-stabilizing effects of CBD in endotoxic shock and suggest a possible beneficial effect of this natural cannabinoid.</p

Mean first-passage times for solvated LiCN isomerization at intermediate to high temperatures

The following article appeared in The Journal of Chemical Physics 156 (2022): 034103 and may be found at https://aip.scitation.org/doi/full/10.1063/5.0065090The behavior of a particle in a solvent has been framed using stochastic dynamics since the early theory of Kramers. A particle in a chemical reaction reacts slower in a diluted solvent because of the lack of energy transfer via collisions. The flux-over-population reaction rate constant rises with increasing density before falling again for very dense solvents. This Kramers turnover is observed in this paper at intermediate and high temperatures in the backward reaction of the LiNC ⇌ LiCN isomerization via Langevin dynamics and mean first-passage times (MFPTs). It is in good agreement with the Pollak-Grabert-Hänggi (PGH) reaction rates at lower temperatures. Furthermore, we find a square root behavior of the reaction rate at high temperatures and have made direct comparisons of the methods in the intermediate- and high-temperature regimes, all suggesting increased ranges in accuracy of both the PGH and MFPT approache

Nearby supernova host galaxies from the CALIFA survey: II. Supernova environmental metallicity

The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule the progenitor's fate. We present the second study of nearby supernova (SN) host galaxies (0.005 10 dex) by targeted searches. We neither found evidence that the metallicity at the SN location differs from the average metallicity at the galactocentric distance of the SNe. By extending our SN sample with published metallicities at the SN location, we are able to study the metallicity distributions for all SN subtypes split into SN discovered in targeted and untargeted searches. We confirm a bias toward higher host masses and metallicities in the targeted searches. By combining data from targeted and untargeted searches, we found a sequence from higher to lower local metallicity: SN Ia, Ic, and II show the highest metallicity, which is significantly higher than those of SN Ib, IIb, and Ic-BL. Our results support the scenario according to which SN Ib result from binary progenitors. Additionally, at least part of the SN Ic are the result of single massive stars that were stripped of their outer layers by metallicity-driven winds. We studied several proxies of the local metallicity that are frequently used in the literature and found that the total host metallicity allows estimating the metallicity at the SN location with an accuracy better than 0.08 dex and very small bias. In addition, weak AGNs that cannot be seen in the total spectrum may weakly bias (by 0.04 dex) the metallicity estimate that is derived from the galaxy-integrated spectrum. © ESO, 2016.This work was partly funded by FCT with the research grant PTDC/CTE-AST/112582/2009. Support for L.G. is partially provided by FCT, by CONICYT through FONDECYT grant 3140566, and from the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC12009, awarded to The Millennium Institute of Astrophysics (MAS). V.S. acknowledges financial support from Fundacao para a Ciencia e a Tecnologia (FCT) under program Ciencia 2008. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912.Peer Reviewe