13,255 research outputs found
The Kovacs effect in the one-dimensional Ising model: a linear response analysis
We analyze the so-called Kovacs effect in the one-dimensional Ising model
with Glauber dynamics. We consider small enough temperature jumps, for which a
linear response theory has been recently derived. Within this theory, the
Kovacs hump is directly related to the monotonic relaxation function of the
energy. The analytical results are compared with extensive Monte Carlo
simulations, and an excellent agreement is found. Remarkably, the position of
the maximum in the Kovacs hump depends on the fact that the true asymptotic
behavior of the relaxation function is different from the stretched exponential
describing the relevant part of the relaxation at low temperatures.Comment: accepted for publication in Phys. Rev.
Perfiles genéticos de poblaciones de gatos domésticos (Felis catus) de la provincia de Girona (Cataluña, NE España) y relaciones genéticas con otras poblaciones europeo-occidentales
RanBP2-Mediated SUMOylation Promotes Human DNA Polymerase Lambda Nuclear Localization and DNA Repair
Cellular DNA is under constant attack by a wide variety of agents, both endogenous and exogenous. To counteract DNA damage, human cells have a large collection of DNA repair factors. Among them, DNA polymerase lambda (Polλ) stands out for its versatility, as it participates in different DNA repair and damage tolerance pathways in which gap-filling DNA synthesis is required. In this work we show that human Polλ is conjugated with Small Ubiquitin-like MOdifier (SUMO) proteins both in vitro and in vivo, with Lys27 being the main target of this covalent modification. Polλ SUMOylation takes place in the nuclear pore complex and is mediated by the E3 ligase RanBP2. This post-translational modification promotes Polλ entry into the nucleus, which is required for its recruitment to DNA lesions and stimulated by DNA damage induction. Our work represents an advance in the knowledge of molecular pathways that regulate cellular localization of human Polλ, which are essential to be able to perform its functions during repair of nuclear DNA, and that might constitute an important point for the modulation of its activity in human cells
Kinematic study of planetary nebulae in NGC 6822
By measuring precise radial velocities of planetary nebulae (which belong to
the intermediate age population), H II regions, and A-type supergiant stars
(which are members of the young population) in NGC 6822, we aim to determine if
both types of population share the kinematics of the disk of H I found in this
galaxy.
Spectroscopic data for four planetary nebulae were obtained with the high
spectral resolution spectrograph Magellan Inamori Kyocera Echelle (MIKE) on the
Magellan telescope at Las Campanas Observatory. Data for other three PNe and
one H II region were obtained from the SPM Catalog of Extragalactic Planetary
Nebulae which employed the Manchester Echelle Spectrometer attached to the 2.1m
telescope at the Observatorio Astron\'omico Nacional, M\'exico. In the
wavelength calibrated spectra, the heliocentric radial velocities were measured
with a precision better than 5-6 km s. Data for three additional H II
regions and a couple of A-type supergiant stars were collected from the
literature. The heliocentric radial velocities of the different objects were
compared to the velocities of the H i disk at the same position.
From the analysis of radial velocities it is found that H II regions and
A-type supergiants do share the kinematics of the H I disk at the same
position, as expected for these young objects. On the contrary, planetary
nebula velocities differ significantly from that of the H I at the same
position. The kinematics of planetary nebulae is independent from the young
population kinematics and it is closer to the behavior shown by carbon stars,
which are intermediate-age members of the stellar spheroid existing in this
galaxy. Our results are confirming that there are at least two very different
kinematical systems in NGC 6822
Variability of primary production during the spring bloom in NW Iberia: what can we learn from a biophysical model?
A biogeochemical model for North and Northwest Iberia: some applications
The Coastal and Ocean modeling group at the Spanish Institute of Oceanography (IEO) has a broad experience in hydrodynamic modeling with ROMS in the area of West and North Iberia. Our main task consists of providing insight on the coastal and ocean dynamics in support to the intense IEO ecosystem and fisheries research in the area.
The NW coast of Iberia is characterized by high levels of primary production that result from relatively frequent and intense inputs of nutrients caused by upwelling, especially in spring and summer. Primary production sustains wealthy fisheries and aquaculture industries, which constitute a prime economic activity in the region.
As a first approach to understand the ecosystem variability in the area we focused on the spring bloom. A high resolution (~3 km) configuration of the ROMS physical model with atmospheric forcing coming from the regional agency Meteogalicia (http://www.meteogalicia.es), which has shown to represent the main features of the shelf and slope circulation in the area, was run coupled to the Fasham-type Fennel biogeochemical model (N2PZD2).
Any biogeochemical model aimed at providing a reliable representation of the dynamics of a certain area should be tuned according to its characteristics. In an upwelling system, the composition of phytoplankton varies from the beginning to the end of the bloom. When nutrients and irradiance are high, diatoms are the dominant group, whereas flagellates become more important when upwelling relaxes and, consequently, nutrients and light intensity decrease. In the NW Iberian coast, it has been found that Chaetoceros socialis is the dominant diatom species during the spring bloom (Bode et al, 1996, 1998). For this reason, we have decided to use parameters that are characteristic of plankton at the spring bloom. In particular, the parameters of Chaetoceros socialis have been considered for the unique phytoplankton class of the model.
We will show comparisons of the model results for 2006 and 2007 with observations at weekly and daily time scales (MODIS chlorophyll-a images, in situ observations from the âInstituto Español de OceanografĂaâ Pelacus cruises). The spring bloom is reasonably reproduced in the NW and N coasts in time, space and intensity. The variability between the primary production in 2006 and 2007 can be related to the oceanographic conditions thanks to the use of a numerical model. The results are promising and encourage us to move forward to increase the complexity of our models and broaden their range of application. We will show some examples of the use of the IEO models to get some insight on sardine recruitment variability and harmful algal bloom prediction
Modeling Iberian sardine Early Life Stages dynamics
The Iberian sardine (Sardina pilchardus) constitutes a traditional target species in western Iberia that
remains to be economically important in Portugal and, to a lesser extent, in Galicia (NW Spain). The
time series of recruitment shows ups and downs in the last decades. According to the ICES Advice
2013 for regions VIII and IXa,
the biomass of age 1 sardine and older has decreased since 2006 and
recruitment has been below the long term average since 2005. In order to understand these
fluctuations, a Lagrangian model to simulate sardine Early Life Stages (ELS), this is, egg and larvae
stages, has been set up. The results of a high resolution hydrodynamic model for North and Northwest
Iberia have been used as an input of the Lagrangian model Ichthyop (Lett et al., (2008)) to simulate ELS
advection and dispersion. Ichthyop has been adapted to sardine by including some biological
behavior. A biogeochemical model coupled to the hydrodynamic model was also used to get some
insight on recruitment for years 2006 2007
The IEO coastal observatory: understanding variability of coastal circulation and ecosystem response off North and North West Iberia
ATLANTOS; GAI
Cognitive Fusion Mediates the Relationship between Dispositional Mindfulness and Negative Affects: A Study in a Sample of Spanish Children and Adolescent School Students
Nowadays, mindfulness-based interventions (MBI) have experienced a remarkable
development of studies among childhood and adolescent interventions. For this reason, dispositional
mindfulness (DM) measures for children and adolescents have been developed to determine the
e ectiveness of MBI at this age stage. However, little is known about how key elements of
DM (for example, cognitive de/fusion or experiential avoidance that both confirm psychological
inflexibility) are involved in the mechanisms of the children and adolescentsâ mental health outcomes.
This research examined the mediating e ect of cognitive fusion between DM and anxiety and other
negative emotional states in a sample of 318 Spanish primary-school students (aged between 8 and 16
years, M = 11.24, SD = 2.19, 50.8% males). Participants completed the AFQ-Y (Avoidance and Fusion
Questionnaire for youth), which is a measure of psychological inflexibility that encompasses cognitive
defusion and experiential avoidance; CAMM (DM for children and adolescents), PANAS-N (positive
and negative a ect measure for children, Spanish version of PANASC), and STAIC (an anxiety
measure for children). The study accomplished ethical standards. As MBI relevant literature has
suggested, cognitive defusion was a significant mediator betweenDMand symptoms of both negative
emotions and anxiety in children and adolescents. However, experiential avoidance did not show
any significant mediating relationship. Probably, an improvement of the assessment of experiential
avoidance is needed. MBI programs for children and adolescents may include more activities for
reducing e ects of the cognitive defusion on their emotional distress
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