Search results for "mechanisms"
showing 10 items of 587 documents
Tiam1 as a Signaling Mediator of Nerve Growth Factor-Dependent Neurite Outgrowth
2010
Nerve Growth Factor (NGF)-induced neuronal differentiation requires the activation of members of the Rho family of small GTPases. However, the molecular mechanisms through which NGF regulates cytoskeletal changes and neurite outgrowth are not totally understood. In this work, we identify the Rac1-specific guanine exchange factor (GEF) Tiam1 as a novel mediator of NGF/TrkA-dependent neurite elongation. In particular, we report that knockdown of Tiam1 causes a significant reduction in Rac1 activity and neurite outgrowth induced by NGF. Physical interaction between Tiam1 and active Ras (Ras- GTP), but not tyrosine phosphorylation of Tiam1, plays a central role in Rac1 activation by NGF. In add…
Numerical treatment of radiation processes in the internal shocks of magnetized relativistic outflows
2017
Los blázares son un tipo de núcleo activo de galaxia (AGN, por sus siglas en inglés) que se encuentran entre los objetos astrofísicos más energéticos y violentos, a la par de los brotes de rayos gamma (GRB por sus siglas en inglés). Los procesos físicos y, en particular, el escenario del chorro relativista en el que se genera la radiación ultraenergética detectada por observatorios terrestres y en órbita, han conseguido atraer la atención e interés de los astrónomos y astrofísicos desde su descubrimiento. En la presente tesis investigamos el modelo de choques internos (IS) cuya hipótesis consta del choque de dos capas de plasma con geometría cilíndrica, formando dos ondas de choque que atra…
Affect self-regulation through music
2018
The present dissertation focused on musical affect regulation, i.e. on the use of music to self-regulate affective states such as emotions, moods, and energy levels. In publication I, relevant findings from previous research were extracted and the field’s conceptual clarity and precision was assessed. Besides identifying weaknesses in conceptualization and providing recommendations for future studies, publication I found that not all the elements of affect regulation through music have been equally explored by research. Given the gap observed on the study of musical mechanisms underlying affect regulation, publication II placed a special focus on this component and its association with regu…
Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana
2011
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild- collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify …
Data from: Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana
2012
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1-3 offspring of wild-collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana, that represent different phylogeographic clades which have been separate for ca. 0.5 MY, and which differ to some extent in both traits. Here we characterise the nature and identify the target…
Strategies and mechanisms in musical affect self-regulation: A new model
2017
This study aimed at investigating the associations between regulation strategies and musical mechanisms involved in musical affect self-regulation. A sample of 571 participants was collected and the data regarding the reported strategies and mechanisms were analysed using correspondence analysis (CA). Three bipolar dimensions – cognition, feelings, and body – were retained for interpretation, thus revealing six contrasting strategic uses of music: cognitive work, entertainment, affective work, distraction, revival, and focus on situation. Clear associations between strategies and mechanisms emerged from the CA, connecting cognitive, feelings-focused, and situational processing with individ…
The Impact of Adolescent Internet Addiction on Sexual Online Victimization: The Mediating Effects of Sexting and Body Self-Esteem
2021
Adolescents’ problematic use of the internet and the risk of sexual online victimization are an increasing concern among families, researchers, professionals and society. This study aimed to analyze the interplay between adolescents’ addiction to social networks and internet, body self-esteem and sexual–erotic risk behavior online: sexting, sextortion and grooming. While sexting refers to the voluntary engagement in texting sexual–erotic messages, sextortion and grooming are means of sexual–erotic victimization through the use of the internet. Participants were 1763 adolescents (51% girls), aged 12 to 16 years (M = 14.56
Predicted gamma-ray image of SN 1006 due to inverse Compton emission
2009
We propose a method to synthesize the inverse Compton (IC) gamma-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC gamma-ray images of SN 1006 show morphology in nice agreement with that reported by the H.E.S.S. collaboration. The good correlation found between the observed very-high energy gamma-ray and X-ray/radio appearance can be considered as an evidence that the gamma-ray emission of SN 1006 observed by H.E.S.S. is leptonic in origin, though the hadronic origin may not be excluded.
Endurance in excercise is associated with courtship call rate in decorated cricket, Gryllodes sigillatus
2009
Question: Is sexual signalling (courtship call rate) determined by physiological fitness (energy metabolism at rest), endurance during physically demanding activity, an aspect of immune defence (lytic activity) or body mass? Organism: Pedigree laboratory population of decorated crickets (Gryllodes sigillatus). Methods: Behavioural trial of male courtship call rate and measurements of males’ physiological performance. Covariance analysis exploring the determinants of courtship call rate. Results: We found that endurance was strongly positively associated with the courtship call rate. However, neither the lytic activity nor the resting metabolic rate correlated with courtship call rate. Toget…
Failing to Provide Public Goods: Why the Afghan Army Did Not Fight
2022
The theory of public goods is mainly about the difficulty in paying for them. Our question here is this: Why might public goods not be provided, even if funding is available? We use the Afghan Army as our case study. We explore this issue using a simple model of a public good that can be provided through collective action and peer pressure, by modeling the self-organization of a group (the Afghan Army) as a mechanism design problem. We consider two kinds of transfer subsidies from an external entity such as the U.S. government. One is a Pigouvian subsidy that simply pays the salaries, rewarding individuals who provide effort. The second is an output/resource multiplier (the provision of mil…