Latitudinal trends in human primary activities: characterizing the winter day as a synchronizer

This work analyzes time use surveys from 19 countries (17 European and 2 American) in the middle latitude range from 38{\deg} to 61{\deg} latitude accounting for 45% of world population in that range. Time marks for primary activities (sleeping, working and eating) are systematically contrasted against light/dark conditions related to latitude. The analysis reveals that winter sunrise is a synchronizer for labor start time below 54{\deg} where they occur within the winter civil twilight region. Winter sunset is a source of synchronization for labor end times. Winter terminator also punctuate meal times in Europe with dinner times occurring 3h after winter sunset time within a strip of 1h, which is 40% narrower than variability of dinner local times. The sleep-wake cycle of laborers in a weekday is shown to be related to winter sunrise whereas standard population's cycle appears to be irrespective of latitude. The significance of the winter terminator depends on two competing factors average daily labor time (some 7h30m) and winter daytime ---the shortest photoperiod---. Winter terminator gains significance when shortest photoperiod roughly matches to daily labor time plus a reasonable lunch break. That is within a latitude range from 38{\deg} to 54{\deg}. The significance of winter terminator as a source of synchronization is also related to contemporary year round time schedules: the shortest photoperiod represents the worst case scenario the society faces. Average daily sleep times show little trend with the shortest photoperiod slope 5min/h for a Pearson coefficient $r^2=0.242$. Average labor time may have a weak coupling with the shortest photoperiod: slope 29min/h for $r^2=0.338$.Comment: Changes: Descriptive statistics and bivariate correlations added. Introduction, Results and Discussion largely modified. RevTeX4-1 27 pages, 6 figures, 13 tables. Data from Time Use Surveys, Hetus and Eurosta

Isolation and social instigation in animal models of aggression: effects of an mGLU1 receptor antagonist administration

Isolate-induced aggression in male mice is a model widely used in psychoparmacology of aggression. Animals are usually isolated for 30 days and subsequently treated and confronted with an anosmic opponent in a neutral area. For 10 min, the complete agonistic repertoire exhibited by the experimental animals is examined, allowing a detailed analysis of aggressive behaviors and other exploratory and motor behaviors. We have recently investigated the role of glutamate metabotropic receptors (mGluR) in this experimental model. Glutamate is the major excitatory neurotransmitter in the brain and it acts both at ionotropic (NMDA, AMPA and kainate receptors) and mGluRs, which are members of the G-protein-coupled receptor family. Eight mGluRs have been characterized and grouped into three classes: group I (mGlu1 and 5), group II (mGlu2 and 3) and group III (mGlu4, 6, 7 and 8). We have tested selective ligands available for the subtypes of mGluRs. Group I antagonists were the most effective ones reducing aggression, being especially remarkable the antiaggressive action observed after the administration of JNJ16259685 (an mGlu1 selective antagonist; 0.125-8 mg/kg i.p.), that produced a strong reduction of offensive behaviors (threat and attack), without affecting immobility with all doses. In this context, we wonder whether this drug could also reduce forms of intensified-heightened aggression. In recent years there is an increasing interest in studying excessive-abnormal forms of aggression in rodents, with the aim of providing a higher translational value to the observed violence in humans, in which aggression becomes intense, disproportionate and dysfunctional. We select a social instigation model, where mice are exposed to a brief territory intrusion of an adult male mice physically inaccessible. After this social provocation mice are exposed to a second opponent which now is unprotected. Social instigation dramatically increases aggressive behaviors, which renders this model appropriate for investigating the neurobiological mechanisms of excessive aggressive behavior. Therefore, we implemented a social instigation procedure in the isolation-induced aggression model with a double objective: first, to examine whether “instigation” could increase the aggression obtained by social isolation; and second, to evaluate the antiaggressive effect of an mGlu1 antagonist in heightened aggression. For this purpose, an acute dose of JNJ16259685 (0.5 mg/kg) was administrated to socially instigated animals after isolation, as well as to animals only isolated. Our results revealed that social instigation reduced latency of attack and increased the frequency and duration of attacks against not instigated animals, without affecting motor behaviors. Likewise, JNJ16259685 (0.5 mg/kg) administration significantly reduced aggressive behaviors in both cases. Taken together, this study shows that social instigation is an useful experimental procedure that increases significantly the levels of aggression observed in an isolated-induced aggression model, also demonstrating the involvement of mGlu1 receptors in the modulation of normal and heightened aggression in male mice.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The genus Gertrudiella broth. (Pottiaceae, Bryophyta) in Paraguay

As part of a study of the bryophytes of South America, some samples collected in Paraguay were identified as Gertrudiella uncinicoma, a species of Pottiaceae characterized by the presence of a well-developed central strand and a thick-walled hyalodermis on the stem, lanceolate leaves, laminal cells ventrally mammillose, and several rows of guides cells at the transverse section of the costae. This work represents the first record of the genus from Paraguay. A complete description, ecological comments, illustrations in optical and scanning electron microscopy, and a distribution map are presented.Fil: Jimenez, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Suarez, Guillermo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán; Argentin

Non-thermal emission from stellar bow shocks

Since the detection of non-thermal radio emission from the bow shock of the massive runaway star BD +43$^{\circ}$3654 simple models have predicted high-energy emission, at X and gamma-rays, from these Galactic sources. Observational searches for this emission so far give no conclusive evidence but a few candidates at gamma rays. In this work we aim at developing a more sophisticated model for the non-thermal emission from massive runaway star bow shocks. The main goal is to establish whether these systems are efficient non-thermal emitters, even if they are not strong enough to be yet detected. For modeling the collision between the stellar wind and the interstellar medium we use 2D hydrodynamic simulations. We then adopt the flow profile of the wind and the ambient medium obtained with the simulation as the plasma state for solving the transport of energetic particles injected in the system, and the non-thermal emission they produce. For this purpose we solve a 3D (2 spatial + energy) advection-diffusion equation in the test-particle approximation. We find that a massive runaway star with a powerful wind converts 0.16-0.4% of the power injected in electrons into non-thermal emission, mostly produced by inverse Compton scattering of dust-emitted photons by relativistic electrons, and secondly by synchrotron radiation. This represents a fraction of $\sim$ $10^{-5}-10^{-4}$ of the wind kinetic power. Given the better sensibility of current instruments at radio wavelengths theses systems are more prone to be detected at radio through the synchrotron emission they produce rather than at gamma energies.Comment: 18 pages, 12 figures. Accepted for publication in Ap

What season suits you best? Seasonal light changes and cyanobacterial competition

Nearly all living organisms, including some bacterial species, exhibit biological processes with a period of about 24 h called circadian (from the Latin circa, about and dies, day) rhythms. These rhythms allow living organisms to anticipate the daily alternation of light and darkness. Experiments carried out in cyanobacteria have shown the adaptive value of circadian clocks. In theseexperiments, a wild type cyanobacterial strain (with a 24 h circadian rhythm) and a mutantstrain (with a longer or shorter period) grow in competition. In different experiments, the external light dark cycle was chosen to match the circadian period of the different strains, revealing that the strain whose circadian period matches the light-dark cycle has a larger fitness. As a consequence, the initial population of one strain grows while the other decays. These experiments were made under fixed light and dark intervals. In Nature, however, this relationship changes according to the season. Therefore, seasonalchanges in light could affect the results of the competition. Using a theoretical model, we analyze how modulation of light can change the survival of the different cyanobacterial strains. Our results show that there is a clear shift in the competition due to the modulation of light, which could be verified experimentally.Fil: Cascallares, Maria Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Gleiser, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin