293 research outputs found
Rare top decay and CP violation in THDM
We discuss the formalism of two Higgs doublet model type III with CP
violation from CP-even CP-odd mixing in the neutral Higgs bosons. The flavor
changing interactions among neutral Higgs bosons and fermions are presented at
tree level in this type of model. These assumptions allow the study rare top
decays mediated by neutral Higgs bosons, particularly we are interested in
. For this process we estimated upper bounds of the
branching ratios of the order of
for a neutral Higgs boson mass of 125 GeV and
, 1.5, 2, 2.5. For the case of the
number of possible events is estimated from 1 to 10 events which could be
observed in future experiments at LHC with a luminosity of 300
and 14 GeV for the energy of the center of mass. Also we
estimate that the number of events for the process in
different scenarios is of order of .Comment: 8 pages, 5 figure
Morphogen Transport in Epithelia
We present a general theoretical framework to discuss mechanisms of morphogen
transport and gradient formation in a cell layer. Trafficking events on the
cellular scale lead to transport on larger scales. We discuss in particular the
case of transcytosis where morphogens undergo repeated rounds of
internalization into cells and recycling. Based on a description on the
cellular scale, we derive effective nonlinear transport equations in one and
two dimensions which are valid on larger scales. We derive analytic expressions
for the concentration dependence of the effective diffusion coefficient and the
effective degradation rate. We discuss the effects of a directional bias on
morphogen transport and those of the coupling of the morphogen and receptor
kinetics. Furthermore, we discuss general properties of cellular transport
processes such as the robustness of gradients and relate our results to recent
experiments on the morphogen Decapentaplegic (Dpp) that acts in the fruit fly
Drosophila
Editorial: The adaptation and response of aquatic animals in the context of global climate change
Editorial on the Research Topic
The adaptation and response of aquatic animals in the context of global climate change
Anthropogenic climate change has brought on widespread changes in marine environments, including ocean warming, ocean acidification, the development and expansion of hypoxic zones. These environmental changes represent major threats to marine life, challenging the survival and adaptation of marine organisms. The adverse effects of these changes can interact in synergistic, additive or antagonistic ways (Huo et al., 2019a; Huo et al., 2019b; Small et al., 2020; Collins et al., 2021), evidencing different biological influence compared to their individual action (Huo et al., 2021a). Such influence can vary across populations and species as a consequence of differences in phenotypic plasticity and physiological tolerances shaped by their specific environmental and genetic backgrounds (Gaitán-Espitia et al., 2017a; Gaitán-Espitia et al., 2017b). These factors ultimately modulate the ecological response and evolutionary adaptation of marine organisms to climate change. From an ecological perspective, changes in the marine environment are likely to have significant negative phenotypic effects (e.g., physiology, behavior, gene/protein expression), across levels of biological organization (i.e., from individuals, populations, to species). These changes can alter the ingestion, digestion, respiration and growth of aquatic animals (Huo et al., 2018), potentially influencing demographic and genetic declines driven, for instance, by massive mortality (Huo et al., 2021b). From an adaptive evolution perspective, phenotypic plasticity appears to be a suitable strategy to cope with these changes, at least in the short-term, through behavioral, physiological, life-history and morphological adjustments (Gaitán-Espitia et al., 2017b). However, there are limits for plastic adjustments beyond which populations and species require genetic and cellular modifications to adapt to the unfavorable environmental conditions. These adaptive responses include microevolutionary changes of transcriptional, translational and post-translational mechanisms underpinning phenotypic responses (Huo et al., 2021b). Through the study of these mechanisms, we can gain better understanding of the costs and trade-offs of adaptive evolution in marine animals under climate change
Apocalipse: fé e resistência
The Apocalypse by John inherits a valuable literary and theological tradition which was originated in Israel and that, from the very beginning, aimed to provide a strong answer to the ruling political power without the need of using armed violence; on the contrary, its purpose was to encourage the readers to endure their oppressors. A study of the social and historical situation which surrounded the writing of the Apocalypse demands an analysis of the ideological strategies used by the Roman Empire as a means to penetrate the mind of their vassals and try to make of the population an obedient and controlled mass. The following paper, based on some of the modern techniques of political propaganda, reveals the means used by Rome to exercise an articulated and unified power, which was intended to be seen as ordered and beautiful; but that, actually, did not fear to execute those who were not obedient. Against that general background, the Apocalypse outlines a political theology of hope and resistance. Which follows is a serious proposal because it takes into account the victims and invites them to regard the slaughtered but standing lamb as the paradigm of the triumph of life.El Apocalipsis de Juan es heredero de una rica tradición literaria y teológica que nació en Israel y que, desde sus inicios, pretendió brindar una respuesta firme al poder político imperante, sin recurrir a la violencia armada, y, por el contrario, crear en los lectores una voluntad de resistencia ante los opresores. El estudio de la situación social e histórica que rodeó la composición del Apocalipsis exige analizar las estrategias ideológicas que empleó el imperio romano como medio para penetrar las conciencias de los súbditos e intentar hacer de la población una masa sumisa y controlada. Este estudio, apoyado en las técnicas modernas de la propaganda política, pone en evidencia las formas que empleó Roma para ejercer un poder articulado, unificado, que aparentaba orden y belleza, pero que, en realidad, no temía llegar hasta el asesinato contra los insumisos. En ese panorama, el Apocalipsis plantea una teología política de la esperanza y de la resistencia. Este es un planteamiento serio porque tiene en cuenta a las víctimas y las invita a contemplar al cordero degollado pero de pie como el paradigma del triunfo de la vida. O Apocalipse de João é herdeiro de uma rica tradição literária e teológica que nasceu em Israel e que, desde seus inícios, pretendeu oferecer uma resposta firme ao poder político imperante, sem valer-se da violência armada, mas, pelo contrário, permite criar nos leitores uma vontade de resistência ante os opressores. O estudo da situação social e histórica que rodeou a composição do Apocalipse exige analisar as estratégias ideológicas que empregou o Império Romano, como meio para penetrar as consciências dos súditos e tentar fazer da população uma massa submissa e controlada. Este estudo, apoiado nas técnicas modernas da propaganda política, põe em evidência as formas que empregou Roma para exercer um poder articulado, unificado, que aparentava ordem e beleza, mas que, na realidade, não temia chegar até o assassinato dos não submissos. Nesse panorama, o Apocalipse traça uma teologia política da esperança e da resistência. Este é um delineamento sério, porque considera as vítimas e as convida a contemplar o cordeiro degolado, mas de pé, como o paradigma do triunfo da vida
Molecular gas at supernova local environments unveiled by EDGE
CO observations allow estimations of the gas content of molecular clouds,
which trace the reservoir of cold gas fuelling star formation, as well as to
determine extinction via H column density, N(H). Here, we studied
millimetric and optical properties at 26 supernovae (SNe) locations of
different types in a sample of 23 nearby galaxies by combining molecular
CO (J = 1 0) resolved maps from the EDGE survey and
optical Integral Field Spectroscopy from the CALIFA survey. We found an even
clearer separation between type II and type Ibc SNe in terms of molecular gas
than what we found in the optical using H emission as a proxy for
current SF rate, which reinforces the fact that SNe Ibc are more associated
with SF-environments. While A at SN locations is similar for SNe II and SNe
Ibc, and higher compared to SNe Ia, N(H) is significantly higher for SNe
Ibc than for SNe II and SNe Ia. When compared to alternative extinction
estimations directly from SN photometry and spectroscopy, we find that our SNe
Ibc have also redder color excess but showed standard Na I D absorption
pseudo-equivalent widths (1 \AA). In some cases we find no extinction
when estimated from the environment, but high amounts of extinction when
measured from SN observations, which suggests that circumstellar material or
dust sublimation may be playing a role. This work serves as a benchmark for
future studies combining last generation millimeter and optical IFS instruments
to reveal the local environmental properties of extragalactic SNe.Comment: MNRAS accepted, 17 pages, 8 Figures, 4 Table
- …