2,240 research outputs found
Observing Grasping Actions Directed to Emotion-Laden Objects: Effects upon Corticospinal Excitability
The motor system is recruited whenever one executes an action as well as when one observes the same action being executed by others. Although it is well established that emotion modulates the motor system, the effect of observing other individuals acting in an emotional context is particularly elusive. The main aim of this study was to investigate the effect induced by the observation of grasping directed to emotion-laden objects upon corticospinal excitability (CSE). Participants classified video-clips depicting the right-hand of an actor grasping emotion-laden objects. Twenty video-clips differing in terms of valence but balanced in arousal level were selected. Motor evoked potentials (MEPs) were then recorded from the first dorsal interosseous using transcranial magnetic stimulation (TMS) while the participants observed the selected emotional video-clips. During the video-clip presentation, TMS pulses were randomly applied at one of two different time points of grasping: (1) maximum grip aperture, and (2) object contact time. CSE was higher during the observation of grasping directed to unpleasant objects compared to pleasant ones. These results indicate that when someone observes an action of grasping directed to emotion-laden objects, the effect of the object valence promotes a specific modulation over the motor system.Fil: Nogueira Campos, Anaelli A.. Universidade Federal de Juiz de Fora; BrasilFil: Saunier, Ghislain. Universidade Federal do ParĂĄ; BrasilFil: Della Maggiore, Valeria Monica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de FisiologĂa y BiofĂsica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de FisiologĂa y BiofĂsica Bernardo Houssay; ArgentinaFil: De Oliveira, Laura A. S.. Centro UniversitĂĄrio Augusto Motta; BrasilFil: Rodrigues, Erika C.. Centro UniversitĂĄrio Augusto Motta; BrasilFil: Vargas, Claudia D.. Universidade Federal do Rio de Janeiro; Brasi
Changes in physical activity and screen time related to psychological well-being in early adolescence: findings from longitudinal study ELANA.
BackgroundPsychological well-being influences health behaviours differently in adolescent boys and girls. We evaluated the role of psychological well-being in early adolescence in the onset and persistence of insufficient physical activity and exceeding recommended screen time, depending on gender.MethodsThis work derives from a cohort study called Longitudinal Study of Adolescent Nutritional Assessment conducted among elementary school students from two public and four private schools in Rio de Janeiro, Brazil from 2010-2013. We analysed data from 2010 and 2012 from 526 adolescents. Physical activity was evaluated using the International Physical Activity Questionnaire. Those who performed less than 60Â min per day of moderate to vigorous physical activity (MVPA) were classified as insufficiently active. Screen time was evaluated based on daily time spent in front of television, video games, and computers. Those who had 4Â h or more screen time per day were classified as exceeding the recommended time. Psychological well-being was assessed using the psychological domain of the KIDSCREEN 27 questionnaire. Linear regression was used to estimate coefficient (ÎČ) and r (2) values for continuous variables. Relative risks (RR) and confidence intervals (95Â % CI) for onset and persistence of insufficient activity and exceeding recommended screen time were estimated with Poisson regression models.ResultsAmong girls, linear regression analyses showed a significant inverse association between psychological well-being and screen minutes per day at T2 (r (2)â=â0.049/ÎČâ= -3.81 (95Â % CI -7.0, -0.9)), as well as an association between poor psychological well-being and onset of exceeding recommended screen time in categorical analyses (RR crude: 1.3; CI 95Â % 1.1, 1.7; RR adjusted: 1.3; CI 95Â % 1.0, 1.6). For boys, an association was found between psychological well-being and onset of insufficient activity 2Â years later (RR crude: 1.3; CI 95Â % 1.2, 1.4; RR adjusted: 1.2; CI 95Â % 1.1, 1.4).ConclusionAdolescence is crucial for the development of unhealthy behaviours related to psychological well-being status in the context of a middle-income country. Gender differences are important because poor psychological well-being seems to affect sedentary behaviour in girls more than in boys, and predicts insufficient activity among boys
On the massâtoâlight ratios of fossil groups. Are they simply dark clusters?
Defined as Xâray bright galaxy groups with large differences between the luminosities of their brightest and second brightest galaxies, âfossil groupsâ are believed to be some of the oldest galaxy systems in the Universe. They have therefore been the subject of much recent research. In this work we present a study of 10 fossil group candidates with an average of 33 spectroscopically confirmed members per group, making this the deepest study of its type to date. We also use these data to perform an analysis of the luminosity function of our sample of fossil groups. We confirm the high masses previously reported for many of fossil systems, finding values more similar to those of clusters than of groups. We also confirm the high dynamical massâtoâlight ratios reported in many previous studies. While our results are consistent with previous studies in many ways, our interpretation is not. This is because we show that, while the luminosities of the bright central galaxies (BCGs) in these systems are consistent with their high dynamical masses, their richnesses (total number of galaxies above some canonical value) are extremely low. This leads us to suggest a new interpretation of fossil systems in which the large differences between the luminosities of their brightest and second brightest galaxies are simply the result of the high BCG luminosities and low richnesses, while the high masses and low richnesses also explain the high massâtoâlight ratios. Our results therefore suggest that fossil systems can be characterized as clusterâlike in their masses and BCG luminosities, but possessing the richnesses and optical luminosities of relatively poor groups. These findings are not predicted by any of the current models for the formation of fossil groups. Therefore, if this picture is confirmed, current ideas about the formation and evolution of fossil systems will need to be reformulated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89559/1/j.1365-2966.2011.19625.x.pd
Globular Clusters around Galaxies in Groups
We have obtained deep photometry of NGC 1199 (in HCG 22) and NGC 6868 (in the
Telescopium group). Both galaxies are the optically brightest galaxies of their
groups. Our analysis of B and R images taken with the Keck II and the VLT/ESO
telescopes, detected a population of globular clusters around both galaxies,
with total specific frequencies S_N=1.7\pm0.6 for NGC 1199 and S_N = 1.3\pm0.6
for NGC 6868. The color distributions of the globular cluster systems shows
bimodal peaks centered at (B-R)_0 = 1.13\pm0.10 and 1.42\pm0.10 (NGC 1199) and
(B-R)_0=1.12\pm0.10 and 1.42\pm0.10 (NGC 6868).Comment: 3 pages, 1 figure. To appear in the proceedings of IAU Symp. 207,
"Extragalactic Star Clusters", eds. E. Grebel, D. Geisler, D. Minnit
The luminosity function of the fossil group RX J1552.2+2013
We determine the first fossil group luminosity function based on spectroscopy
of the member galaxies. The fossil group RX J1552.2+2013 has 36 confirmed
members, it is at a mean redshift of 0.136 and has a velocity dispersion of 623
km/s (or 797 km/s if four emission lines galaxies in the outskirts of the
velocity distribution are included). The luminosity function of RX
J1552.2+2013, measured within the inner region of the system ~1/3 R_vir), in
the range -23.5< M_i'<-17.5, is well fitted by a Schechter function with
M*i'=-21.3 +/- 0.4 and alpha = -0.6 +/- 0.3 or a Gaussian function centered on
M_i'= -20.0 +/- 0.4 and with sigma=1.29 +/- 0.24 i' mag. (H_0 = 70 km/s Mpc,
Omega_M=0.3, Omega_Lambda=0.7. The luminosity function obtained from a
photometric survey in g', r', i'-bands (and statistical background correction)
confirms the spectroscopically determined results. There is a significant dip
in the luminosity function at M_r'=-18 mag, as also observed for other
clusters. RX~J1552.2+2013 is a rich, strongly red-galaxy dominated system, with
at least 19 galaxies with magnitudes between m_3 and m_3 + 2, within a surveyed
circular area of radius 625 kpc centered on the peak of the x-ray emission. Its
mass, ~3.0 10^14 M_0, M/L of 507 M_sol/L_B_sol and L_X of 6.3 10^43 ergs/s
(bolometric) are more representative of a fossil cluster than of a fossil
group. The central object of RX J1552.2+2013 is a cD galaxy which may have
accreted the more luminous ~L* former members of the group. Although dynamical
friction and subsequent merging are probably the processes responsible for the
lack of bright galaxies in the system, for the fainter members, there must be
another mechanism in action (perhaps tidal disruption) to deplete the fossil
group from intermediate-luminosity galaxies M_r' ~ -18.Comment: 14 pages, 7 Figures. accepted by A
Effect of a single session of transcranial direct-current stimulation on balance and spatiotemporal gait variables in children with cerebral palsy: A randomized sham-controlled study
Background: Transcranial direct-current stimulation (tDCS) has been widely studied with the aim of enhancing local synaptic efficacy and modulating the electrical activity of the cortex in patients with neurological disorders. Objective: The purpose of the present study was to determine the effect of a single session of tDCS regarding immediate changes in spatiotemporal gait and oscillations of the center of pressure (30 seconds) in children with cerebral palsy (CP). Method: A randomized controlled trial with a blinded evaluator was conducted involving 20 children with CP between six and ten years of age. Gait and balance were evaluated three times: Evaluation 1 (before the stimulation), Evaluation 2 (immediately after stimulation), and Evaluation 3 (20 minutes after the stimulation). The protocol consisted of a 20-minute session of tDCS applied to the primary motor cortex at an intensity of 1 mA. The participants were randomly allocated to two groups: experimental group - anodal stimulation of the primary motor cortex; and control group - placebo transcranial stimulation. Results: Significant reductions were found in the experimental group regarding oscillations during standing in the anteroposterior and mediolateral directions with eyes open and eyes closed in comparison with the control group (p<0.05). In the intra-group analysis, the experimental group exhibited significant improvements in gait velocity, cadence, and oscillation in the center of pressure during standing (p<0.05). No significant differences were found in the control group among the different evaluations. Conclusion: A single session of tDCS applied to the primary motor cortex promotes positive changes in static balance and gait velocity in children with cerebral palsy
Velocity dispersion, mass and the luminosity function of the fossil cluster RX J1416.4+2315
We study the properties of the fossil cluster RX J1416.4+2315 through g' and
i'-band imaging and spectroscopy of 25 member galaxies. The system is at a mean
redshift of 0.137 and has a velocity dispersion of 584 km s^-1. Superimposed
onto one quadrant of the cluster field there is a group of five galaxies at a
mean redshift of 0.131, which, if included as part of the cluster, increases
the velocity dispersion to 846 km/s. The central object of RX J1416.4+2315 is a
normal elliptical galaxy, with no cD envelope. The luminosity function of the
system, estimated by the number counts, and statistical background correction,
in the range -22.6< M_g'< -16.6, is well fitted by a Schechter function with
M_g'^* = -21.2 +/- 0.8 and alpha = -1.2 +/- 0.2 (H_0 = 70 km s^-1 Mpc^-1,
Omega_M=0.3, Omega_Lambda=0.7). The luminosity function obtained from the
spectroscopically confirmed members in both g' and i' bands agrees with the
photometric results. The mass of the system, M 0.9 \times 10^14 h^-1_70 M_sun,
its M/L of 445 h_70 M_sun/L_B_sun and L_X of 11 10^43 h^-2_70 ergs s^-1
(bolometric) suggest that this system is the second example of known fossil
cluster, after RX J1552.2+2013, confirmed in the literature.Comment: Accepted by AJ - 14 pages, 6 figure
The K luminosity-metallicity relation for dwarf galaxies and the tidal dwarf galaxies in the tails of HCG 31
We determine a K-band luminosity-metallicity (K-Z) relation for dwarf
irregular galaxies, over a large range of magnitudes, -20.5 < M_K < -13.5,
using a combination of K photometry from either the 2-micron all sky survey
(2MASS) or the recent study of Vadivescu er al. (2005), and metallicities
derived mainly with the T_e method, from several different studies. We then use
this newly-derived relation, together with published K_s photometry and our new
spectra of objects in the field of HCG 31 to discuss the nature of the possible
tidal dwarf galaxies of this group. We catalogue a new member of HCG 31, namely
"R", situated ~40 kpc north of the group center, composed by a ring of H alpha
knots which coincides with a peak in HI. This object is a deviant point in the
K-Z relation (it has too high metallicity for its luminosity) and its projected
distance to the parent galaxy and large gas reservoir makes it one of the most
promising tidal dwarf galaxy candidates of HCG 31, together with object F. The
subsystems A1, E, F, H and R all have metallicities similar to that of the
galaxies A+C and B, result that is expected in a scenario where those were
formed from material expelled from the central galaxies of HCG 31. While
objects A1, E and H will most probably fall back onto their progenitors, F and
R may survive as tidal dwarf galaxies. We find that two galaxies of HCG 31, G
and Q, have A+em spectral signatures, and are probably evolving toward a
post-starburst phase.Comment: 32 pages, 4 figures - Submitted to AJ - A version of this paper with
full resolution figures can be found at
http://www.astro.iag.usp.br/~eduardo/HCG31-KZrelation.pd
Challenges and lessons from a primary care intervention in a Brazilian municipality
OBJECTIVE: To address the implementation of the Lab for Innovation in Chronic Conditions in Santo Antonio do Monte, indicating the main challenges and lessons of a new chronic condition model. METHODS: This is an observational study based on two sources of data: 1) two cross-sectional household surveys, 2013 (2012 as reference year) and 2015 (2014 as reference year), representative for the entire population and four target groups (pregnant women; children under two years old; individuals with hypertension and diabetes); medical records of individuals who self-reported having hypertension or diabetes in the household survey of 2013. A descriptive statistics analysis was performed. RESULTS: The main findings showed that the public health system is the main provider of health services, mainly primary care, in Santo Antonio do Monte. Besides, the implementation of Lab for Innovation in Chronic Conditions showed the importance of building a Primary Health Care network in small municipalities. CONCLUSIONS: Community health agents and health managers played a fundamental role in the Primary Health Care network. The case study of Santo Antonio do Monte poses some challenges and lessons that clarify future interventions on building a Primary Health Care network that is essential to provide an adequate and longitudinal care to chronic conditions
- âŠ