76 research outputs found
Gondellied : Barcarolle. Boat-Song.
https://digitalcommons.library.umaine.edu/mmb-ps/1388/thumbnail.jp
A structure in the early Universe at z 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology
A Large Quasar Group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume^1/3) ~ 500 Mpc (proper size, present epoch), longest dimension ~ 1240 Mpc, membership of 73 quasars, and mean redshift = 1.27. In terms of both size and membership it is the most extreme LQG found in the DR7QSO catalogue for the redshift range 1.0 = 1.28, which is itself one of the more extreme examples. Their boundaries approach to within ~ 2 deg (~ 140 Mpc projected). This new, huge LQG appears to be the largest structure currently known in the early universe. Its size suggests incompatibility with the Yadav et al. scale of homogeneity for the concordance cosmology, and thus challenges the assumption of the cosmological principle
TAKE ME BACK TO MOVE ME FORWARD: RE-ENACTMENT OF THE FAMILY SYSTEM AS A PATHWAY TO BETTER QUALITY OF LIFE FOR ALEXITHYMIC PATIENTS IN GROUP THERAPY
Background: Despite much attention in the clinical literature, research on alexithymia in the treatment setting has only recently gained traction. While several reports indicate limited benefit from therapy amongst patients with high alexithymia, this seems to be less so in the context of group therapy. This study considers a specific aspect of the group therapy process - family re-enactment - in facilitating improvement in overall quality of life for patients with high levels of alexithymia.
Subjects and methods: Family re-enactment was examined as a potential mediator of the relationship between alexithymia and change in quality of life among 50 patients who completed treatment in an intensive, integrative group therapy programme. Patients completed three self-report measures: Toronto Alexithymia Scale-20 (baseline), Quality of Life Inventory (baseline, post-therapy), and Therapeutic Factors Inventory-Short Form (week 8). Regression with mediation analysis was employed using the change score for the QOLI as the dependent variable, alexithymia scores as the independent variable, and the family re-enactment score as the mediator; baseline quality of life was included in the model as a control variable.
Results: Family re-enactment emerged as a significant mediator of the relationship between alexithymia and treatment outcome, implicating it as a contributing mechanism of change for alexithymic patients who participate in group therapy.
Conclusion: Patients with higher levels of alexithymia (in particular, difficulty identifying and describing feelings) were more likely to positively endorse aspects of family re-enactment during group therapy, which in turn were significantly associated with greater improvement in patients’ overall quality of life
Triplets of Quasars at high redshift I: Photometric data
We have conducted an optical and infrared imaging in the neighbourhoods of 4
triplets of quasars. R, z', J and Ks images were obtained with MOSAIC II and
ISPI at Cerro Tololo Interamerican Observatory. Accurate relative photometry
and astrometry were obtained from these images for subsequent use in deriving
photometric redshifts. We analyzed the homogeneity and depth of the photometric
catalog by comparing with results coming from the literature. The good
agreement shows that our magnitudes are reliable to study large scale structure
reaching limiting magnitudes of R = 24.5, z' = 22.5, J = 20.5 and Ks = 19.0.
With this catalog we can study the neighbourhoods of the triplets of quasars
searching for galaxy overdensities such as groups and galaxy clusters.Comment: The paper contains 12 figures and 3 table
Catalogue of lichens (and some related fungi) of Navarino Island, Cape Horn Biosphere Reserve, Chile
The Cape Horn Biosphere Reserve, Chile, has been identified as a hotspot of bryophyte diversity and it has been suggested to be the same for lichens. However, in contrast to the extensive bryophyte studies, only preliminary lichen inventories had been conducted in this reserve. We conducted the first intensive study on the diversity of lichens on Navarino Island during the southern summers of 2005 and 2008. We explored the main habitat types of the island, including coastal areas, evergreen and deciduous forests, Magellanic tundra, and high Andean ('alpine') habitats on the mountain summits. The following substrates on which lichens grow were considered: bark, wood (incl. logs, stumps), soil, mosses, and rocks. We recorded a total of 416 taxa, although some of them not identified to species level. A main result is the finding of two species that are proposed as new: The lichen Candelariella magellanica, and the saprobic fungus Sclerococcum nothofagi that grows on the bark of trees of the genus Nothofagus. In addition, one species of lichenicolous fungus is recorded for the first time on Navarino Island: Tremella haematommatis. These results provide additional evidence about the great diversity of lichens that are conserved in the Cape Horn Biosphere Reserve
A QSO plus host system lensed into a 6" Einstein ring by a low redshift galaxy
We report the serendipitous discovery of an "Einstein Ring" in the optical
band from the Sloan Digital Sky Survey (SDSS) data and associated four images
of a background source. The lens galaxy appears to be a nearby dwarf spheroid
at a redshift of 0.03750.002. The lensed quasar is at a redshift of
0.68420.0014 and its multiple images are distributed almost 360
around the lens nearly along a ring of radius 6."0. Single component lens
models require a mass of the galaxy of almost 10 M within 6".0
from the lens center. With the available data we are unable to determine the
exact positions, orientations and fluxes of the quasar and the galaxy, though
there appears evidence for a double or multiple merging image of the quasar. We
have also detected strong radio and X-ray emissions from this system. It is
indicative that this ring system may be embedded in a group or cluster of
galaxies. This unique ring, by virtue of the closeness of the lens galaxy,
offers possible probe to some of the key issues like mass-to-light ratio of
intrinsically faint galaxies, existence of large scale magnetic fields in
elliptical galaxies etc.Comment: 20 pages, 8 figures, accepted for publication in Ap
The nature of proximate damped Lyman alpha systems
We present high resolution echelle spectra of 7 proximate damped Lyman alpha
(PDLA) systems whose relative velocity separation from the background quasar is
Delta V < 3000 km/s. Combining our sample with a further 9 PDLAs from the
literature we compare the chemical properties of the proximate systems with a
control sample of intervening DLAs. Taken at face value, the sample of 16 PDLAs
exhibits a wide range of metallicities, ranging from Z ~ 1/3 Z_sun down to Z ~
1/1000 Z_sun, including the DLA with the lowest N(SiII)/N(HI) yet reported in
the literature. We find several pieces of evidence that indicate enhanced
ionization and the presence of a hard ionizing spectrum in PDLAs which lead to
properties that contrast with the intervening DLAs, particularly when the N(HI)
is low. The abundances of Zn, Si and S in PDLAs with log N(HI) > 21, where
ionization corrections are minimized, are systematically higher than the
intervening population by a factor of around 3. We also find possible evidence
for a higher fraction of NV absorbers amongst the PDLAs, although the
statistics are still modest. 6/7 of our echelle sample show high ionization
species (SiIV, CIV, OVI or NV) offset by >100 km/s from the main low ion
absorption. We analyse fine-structure transitions of CII* and SiII* to
constrain the PDLA distance from the QSO. Lower limits range from tens of kpc
up to >160 kpc for the most stringent limit. We conclude that (at least some)
PDLAs do exhibit different characteristics relative to the intervening
population out to 3000 km/s (and possibly beyond). Nonetheless, the PDLAs
appear distinct from lower column density associated systems and the inferred
QSO-absorber separations mean they are unlikely to be associated with the QSO
host. We speculate that the PDLAs preferentially sample more massive galaxies
in more highly clustered regions of the high redshift universe.Comment: Accepted for publication in MNRAS. Abstract abridged
Knowledge and competency standards for specialized cognitive behavior therapy for adult obsessive-compulsive disorder
Obsessive-Compulsive Disorder (OCD) is a leading cause of disability world-wide (World Health Organization, 2008). Treatment of OCD is a specialized field whose aim is recovery from illness for as many patients as possible. The evidence-based psychotherapeutic treatment for OCD is specialized cognitive behavior therapy (CBT, NICE, 2005, Koran and Simpson, 2013). However, these treatments are not accessible to many sufferers around the world. Currently available guidelines for care are deemed to be essential but insufficient because of highly variable clinician knowledge and competencies specific to OCD. The phase two mandate of the 14 nation International OCD Accreditation Task Force (ATF) created by the Canadian Institute for Obsessive Compulsive Disorders is development of knowledge and competency standards for specialized treatments for OCD through the lifespan deemed by experts to be foundational to transformative change in this field. This paper presents knowledge and competency standards for specialized CBT for adult OCD developed to inform, advance, and offer a model for clinical practice and training for OCD. During upcoming ATF phases three and four criteria and processes for training in specialized treatments for OCD through the lifespan for certification (individuals) and accreditation (sites) will be developed based on the ATF standards
Optimistic Planning for Markov Decision Processes
International audienceThe reinforcement learning community has recently intensified its interest in online planning methods, due to their relative independence on the state space size. However, tight near-optimality guarantees are not yet available for the general case of stochastic Markov decision processes and closed-loop, state-dependent planning policies. We therefore consider an algorithm related to AO* that optimistically explores a tree representation of the space of closed-loop policies, and we analyze the near-optimality of the action it returns after n tree node expansions. While this optimistic planning requires a finite number of actions and possible next states for each transition, its asymptotic performance does not depend directly on these numbers, but only on the subset of nodes that significantly impact near-optimal policies. We characterize this set by introducing a novel measure of problem complexity, called the near-optimality exponent. Specializing the exponent and performance bound for some interesting classes of MDPs illustrates the algorithm works better when there are fewer near-optimal policies and less uniform transition probabilities
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