1,027 research outputs found
Metacognitive self-reflectivity moderates the relationship between distress tolerance and empathy in schizophrenia
Deficits in empathy seen in schizophrenia are thought to play a major role in the social dysfunction seen in the disorder. However, little work has investigated potential determinants of empathic deficits. This study aimed to fill that gap by examining the effects of two variables on empathy – distress tolerance and metacognitive self-reflectivity. Fifty-four people with schizophrenia-spectrum disorders receiving services at an urban VA or community mental health center were assessed for empathy, metacognition, and distress tolerance. Bivariate correlations and moderation methods were used to ascertain associations amongst these variables and examine interactions. Results revealed that, against hypotheses, empathy was not related at the bivariate level to either distress tolerance or metacognitive self-reflectivity. However, consistent with hypotheses, moderation analyses revealed that participants with higher self-reflectivity showed no relationship between distress tolerance and empathy, while those with lower self-reflectivity showed a relationship such that reduced ability to tolerate distress predicted reduced empathy. Taken together, results of this study suggest that lack of distress tolerance can negatively affect empathy in people with schizophrenia with lesser capacity for metacognitive self-reflection; thus, fostering self-reflectivity may help overcome that negative impact. Future work is needed investigating the impact of metacognitively-tailored interventions on empathy in this population
Prospects for near-infrared characterisation of hot Jupiters with VSI
In this paper, we study the feasibility of obtaining near-infrared spectra of
bright extrasolar planets with the 2nd generation VLTI Spectro-Imager
instrument (VSI), which has the required angular resolution to resolve nearby
hot Extrasolar Giant Planets (EGPs) from their host stars. Taking into account
fundamental noises, we simulate closure phase measurements of several
extrasolar systems using four 8-m telescopes at the VLT and a low spectral
resolution (R = 100). Synthetic planetary spectra from T. Barman are used as an
input. Standard chi2-fitting methods are then used to reconstruct planetary
spectra from the simulated data. These simulations show that low-resolution
spectra in the H and K bands can be retrieved with a good fidelity for half a
dozen targets in a reasonable observing time (about 10 hours, spread over a few
nights). Such observations would strongly constrain the planetary temperature
and albedo, the energy redistribution mechanisms, as well as the chemical
composition of their atmospheres. Systematic errors, not included in our
simulations, could be a serious limitation to these performance estimations.
The use of integrated optics is however expected to provide the required
instrumental stability (around 10^-4 on the closure phase) to enable the first
thorough characterisation of extrasolar planetary emission spectra in the
near-infrared.Comment: 10 pages, 8 figures, Proc. SPIE conference 7013 "Optical and Infrared
Interferometry" (Marseille 2008
Metallicity of M dwarfs IV. A high-precision [Fe/H] and Teff technique from high-resolution optical spectra for M dwarfs
Aims. In this work we develop a technique to obtain high precision
determinations of both metallicity and effective temperature of M dwarfs in the
optical.
Methods. A new method is presented that makes use of the information of 4104
lines in the 530-690 nm spectral region. It consists in the measurement of
pseudo equivalent widths and their correlation with established scales of
[Fe/H] and .
Results. Our technique achieves a of 0.080.01 for [Fe/H],
9113 K for , and is valid in the (-0.85, 0.26 dex), (2800, 4100
K), and (M0.0, M5.0) intervals for [Fe/H], and spectral type
respectively. We also calculated the RMSE which estimates uncertainties
of the order of 0.12 dex for the metallicity and of 293 K for the effective
temperature. The technique has an activity limit and should only be used for
stars with . Our method is available
online at \url{http://www.astro.up.pt/resources/mcal}.Comment: Accepted in Astronomy and Astrophysics. Updated one important
reference in the introduction. Some typos correcte
Metallicity of M dwarfs III. Planet-metallicity and planet-stellar mass correlations of the HARPS GTO M dwarf sample
Aims. The aim of this work is the study of the planet-metallicity and the
planet-stellar mass correlations for M dwarfs from the HARPS GTO M dwarf
subsample
Methods. We use a new method that takes advantage of the HARPS
high-resolution spectra to increase the precision of metallicity, using
previous photometric calibrations of [Fe/H] and effective temperature as
starting values.
Results. In this work we use our new calibration (rms = 0.08 dex) to study
the planet-metallicity relation of our sample. The well-known correlation for
Giant planet FGKM hosts with metallicity is present. Regarding Neptunians and
smaller hosts no correlation is found but there is a hint that an
anti-correlation with [Fe/H] may exist. We combined our sample with the
California Planet Survey late-K and M-type dwarf sample to increase our
statistics but found no new trends. We fitted a power law to the frequency
histogram of the Jovian hosts for our sample and for the combined sample, f_p =
C10^\alpha[Fe/H], using two different approaches: a direct bin fitting and a
bayesian fitting procedure. We obtained a value for C between 0.02 and 0.04 and
for \alpha between 1.26 and 2.94.
Regarding stellar mass, an hypothetical correlation with planets was
discovered, but was found to be the result of a detection bias.Comment: Accepted for publication in A&A. 18 pages, 11 Figures, 12 Table
Hormone secreting tumors of the pancreas: Some insights into their clinical and fundamental interest
Metacognitive function and fragmentation in schizophrenia: Relationship to cognition, self-experience and developing treatments
Bleuler suggested that fragmentation of thought, emotion and volition were the unifying feature of the disorders he termed schizophrenia. In this paper we review research seeking to measure some of the aspects of fragmentation related to the experience of the self and others described by Bleuler. We focus on work which uses the concept of metacognition to characterize and quantify alterations or decrements in the processes by which fragments or pieces of information are integrated into a coherent sense of self and others. We describe the rationale and support for one method for quantifying metacognition and its potential to study the fragmentation of a person\u27s sense of themselves, others and the relative place of themselves and others in the larger human community. We summarize research using that method which suggests that deficits in metacognition commonly occur in schizophrenia and are related to basic neurobiological indices of brain functioning. We also present findings indicating that the capacity for metacognition in schizophrenia is positively related to a broad range of aspects of psychological and social functioning when measured concurrently and prospectively. Finally, we discuss the evolution and study of one therapy that targets metacognitive capacity, Metacognitive Reflection and Insight Therapy (MERIT) and its potential to treat fragmentation and promote recovery
The HARPS search for southern extra-solar planets XXXV. Super-Earths around the M-dwarf neighbors Gl433 and Gl667C
M dwarfs have been found to often have super-Earth planets with short orbital
periods. Such stars are thus preferential targets in searches for rocky or
ocean planets in the solar neighbourhood. In a recent paper (Bonfils et al.
2011), we announced the discovery of respectively 1 and 2 low mass planets
around the M1.5V stars Gl433 and Gl667C. We found those planets with the HARPS
spectrograph on the ESO~3.6-m telescope at La Silla Observatory, from
observations obtained during the Guaranteed Time Observing program of that
instrument. We have obtained additional HARPS observations of those two stars,
for a total of respectively 67 and 179 Radial Velocity measurements for Gl433
and Gl667C, and present here an orbital analysis of those extended data sets
and our main conclusion about both planetary systems. One of the three planets,
Gl667Cc, has a mass of only M2.sin(i)~4.25 M_earth and orbits in the central
habitable zone of its host star. It receives just 10% less stellar energy from
Gl667C than the Earth receives from the Sun. However planet evolution in
habitable zone can be very different if the host star is a M dwarf or a
solar-like star, without necessarily questioning the presence of water. The two
other planets, Gl433b and Gl667Cb, both have M2.sin(i) of ~5.5 M_earth and
periods of ~7 days. The Radial Velocity measurements of both stars contain
longer time scale signals, which we fit as longer period Keplerians. For Gl433
that signal probably originates in a Magnetic Cycle, while a longer time span
will be needed to conclude for Gl667C. The metallicity of Gl433 is close to
solar, while Gl667C is metal poor with [Fe/H] ~ -0.6. This reinforces the
recent conclusion that the occurence of Super-Earth planets does not strongly
correlate with stellar metallicity.Comment: 14 pages, 8 figures, submitted to A&
The HARPS search for southern extra-solar planets. VI. A Neptune-mass planet around the nearby M dwarf Gl 581
We report the discovery of a Neptune-mass planet around Gl 581 (M3V, M = 0.31
Msol), based on precise Doppler measurements with the HARPS spectrograph at La
Silla Observatory. The radial velocities reveal a circular orbit of period P =
5.366 days and semi-amplitude K1 = 13.2 m/s. The resulting minimum mass of the
planet (m2 sin i) is only 0.052 Mjup = 0.97 Mnep = 16.6 Mearth making Gl 581b
one of the lightest extra-solar planet known to date. The Gl 581 planetary
system is only the third centered on an M dwarf, joining the Gl 876
three-planet system and the lone planet around Gl 436. Its discovery reinforces
the emerging tendency of such planets to be of low mass, and found at short
orbital periods. The statistical properties of the planets orbiting M dwarfs do
not seem to match a simple mass scaling of their counterparts around solar-type
stars.Comment: letter submitted to A&
The HARPS search for southern extra-solar planets XIX. Characterization and dynamics of the GJ876 planetary system
Precise radial-velocity measurements for data acquired with the HARPS
spectrograph infer that three planets orbit the M4 dwarf star GJ876. In
particular, we confirm the existence of planet "d", which orbits every 1.93785
days. We find that its orbit may have significant eccentricity (e=0.14), and
deduce a more accurate estimate of its minimum mass of 6.3 Earth masses.
Dynamical modeling of the HARPS measurements combined with literature
velocities from the Keck Observatory strongly constrain the orbital
inclinations of the "b" and "c" planets. We find that i_b = 48.9 degrees and
i_c = 48.1 degrees, which infers the true planet masses of M_b = 2.64 Jupiter
masses and M_c = 0.83 Jupiter masses, respectively. Radial velocities alone, in
this favorable case, can therefore fully determine the orbital architecture of
a multi-planet system, without the input from astrometry or transits.
The orbits of the two giant planets are nearly coplanar, and their 2:1 mean
motion resonance ensures stability over at least 5 Gyr. The libration amplitude
is smaller than 2 degrees, suggesting that it was damped by some dissipative
process during planet formation. The system has space for a stable fourth
planet in a 4:1 mean motion resonance with planet "b", with a period around 15
days. The radial velocity measurements constrain the mass of this possible
additional planet to be at most that of the Earth.Comment: 10 pages, 10 figures, accepted for publication in Astronomy &
Astrophysic
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