1,576 research outputs found
The CIV-MgII Kinematics Connection in <z>~0.7 Galaxies
We have examined Faint Object Spectrograph data from the Hubble Space
Telescope Archive for CIV 1548,1550 absorption associated with 40 MgII
2796,2803 absorption-selected galaxies at 0.4 < z < 1.4. We report a strong
correlation between MgII kinematics, measured in 6 km/s resolution HIRES/Keck
spectra, and W_r(1548); this implies a physical connection between the
processes that produce "outlying velocity" MgII clouds and high ionization
galactic/halo gas. We found no trend in ionization condition,
W_r(1548)/W_r(2796), with galaxy-QSO line-of-sight separation for 13 systems
with confirmed associated galaxies, suggesting no obvious ionization gradient
with galactocentric distance in these higher redshift galaxies. We find
tentative evidence (2-sigma) that W_r(1548)/W_r(2796) is anti-correlated with
galaxy color; if further data corroborate this trend, in view of the
strong CIV-MgII kinematics correlation, it could imply a connection between
stellar populations, star formation episodes, and the kinematics and ionization
conditions of halo gas at z~1.Comment: Accepted to Astrophysical Journal Letters; 4 pages; 3 figures;
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Postoperative complications are associated with long-term changes in the gut microbiota following colorectal cancer surgery
Changes in the gut microbiome have already been associated with postoperative complications in major abdominal surgery. However, it is still unclear whether these changes are transient or a long-lasting effect. Therefore, the aim of this prospective clinical pilot study was to examine long-term changes in the gut microbiota and to correlate these changes with the clinical course of the patient. Methods: In total, stool samples of 62 newly diagnosed colorectal cancer patients undergoing primary tumor resection were analyzed by 16S-rDNA next-generation sequencing. Stool samples were collected preoperatively in order to determine the gut microbiome at baseline as well as at 6, 12, and 24 months thereafter to observe longitudinal changes. Postoperatively, the study patients were separated into two groups-patients who suffered from postoperative complications
The Physical Conditions of the Intrinsic N V Narrow Absorption Line Systems of Three Quasars
We employ detailed photoionization models to infer the physical conditions of
intrinsic narrow absorption line systems found in high resolution spectra of
three quasars at z=2.6-3.0. We focus on a family of intrinsic absorbers
characterized by N V lines that are strong relative to the Ly-alpha lines. The
inferred physical conditions are similar for the three intrinsic N V absorbers,
with metallicities greater than 10 times the solar value (assuming a solar
abundance pattern), and with high ionization parameters (log U ~ 0). Thus, we
conclude that the unusual strength of the N V lines results from a combination
of partial coverage, a high ionization state, and high metallicity. We consider
whether dilution of the absorption lines by flux from the broad-emission line
region can lead us to overestimate the metallicities and we find that this is
an unlikely possibility. The high abundances that we infer are not surprising
in the context of scenarios in which metal enrichment takes place very early on
in massive galaxies. We estimate that the mass outflow rate in the absorbing
gas (which is likely to have a filamentary structure) is less than a few solar
masses per year under the most optimistic assumptions, although it may be
embedded in a much hotter, more massive outflow.Comment: To appear in the Astrophysical Journa
ESPEN guideline on nutritional support for polymorbid medical inpatients.
BACKGROUND
Disease-related malnutrition in polymorbid medical inpatients is a highly prevalent syndrome associated with significantly increased morbidity, disability, short- and long-term mortality, impaired recovery from illness, and cost of care.
AIM
As there are uncertainties in applying disease-specific guidelines to patients with multiple conditions, our aim was to provide evidence-based recommendations on nutritional support for the polymorbid patient population hospitalized in medical wards.
METHODS
This update adheres to the standard operating procedures for ESPEN guidelines. We did a systematic literature search for 15 clinical questions in three different databases (Medline, Embase and the Cochrane Library), as well as in secondary sources (e.g. published guidelines), until July 12th. Retrieved abstracts were screened to identify relevant studies that were used to develop recommendations (incl. SIGN grading), which was followed by submission to Delphi voting.
RESULTS
From a total of 3527 retrieved abstracts, 60 new relevant studies were analyzed and used to generate a guideline draft that proposed 32 recommendations (7x A, 11x B, 10x O and 4x GPP), which encompass different aspects of nutritional support including indication, route of feeding, energy and protein requirements, micronutrient requirements, disease-specific nutrients, timing, monitoring and procedure of intervention. The results of the first online voting showed a strong consensus (agreement of >90%) on 100% of the recommendations. Therefore, no final consensus conference was needed.
CONCLUSIONS
Recent high-quality trials have provided increasing evidence that nutritional support can reduce morbidity and other complications associated with malnutrition in polymorbid patients. The timely screening of patients for risk of malnutrition at hospital admission followed by individualized nutritional support interventions for at-risk patients should be part of routine clinical care and multimodal treatment in hospitals worldwide. Use of this updated guideline offers an evidence-based nutritional approach to the polymorbid medical inpatients and may improve their outcomes
Neural correlates of enhanced visual short-term memory for angry faces: An fMRI study
Copyright: © 2008 Jackson et al.Background: Fluid and effective social communication requires that both face identity and emotional expression information are encoded and maintained in visual short-term memory (VSTM) to enable a coherent, ongoing picture of the world and its players. This appears to be of particular evolutionary importance when confronted with potentially threatening displays of emotion - previous research has shown better VSTM for angry versus happy or neutral face identities.Methodology/Principal Findings: Using functional magnetic resonance imaging, here we investigated the neural correlates of this angry face benefit in VSTM. Participants were shown between one and four to-be-remembered angry, happy, or neutral faces, and after a short retention delay they stated whether a single probe face had been present or not in the previous display. All faces in any one display expressed the same emotion, and the task required memory for face identity. We find enhanced VSTM for angry face identities and describe the right hemisphere brain network underpinning this effect, which involves the globus pallidus, superior temporal sulcus, and frontal lobe. Increased activity in the globus pallidus was significantly correlated with the angry benefit in VSTM. Areas modulated by emotion were distinct from those modulated by memory load.Conclusions/Significance: Our results provide evidence for a key role of the basal ganglia as an interface between emotion and cognition, supported by a frontal, temporal, and occipital network.The authors were supported by a Wellcome Trust grant (grant number 077185/Z/05/Z) and by BBSRC (UK) grant BBS/B/16178
Low and High Ionization Absorption Properties of Mg II Absorption-Selected Galaxies at Intermediate Redshifts. I. General Properties
We present extensive metal-line absorption properties for 45 absorption
systems that were selected by their Mg II absorption at redshifts between 0.4
and 1.4. For each system the properties of several chemical species are
determined, including a wide range of ionization conditions. In the optical,
the absorption systems have been observed at ~6 km/s resolution with
HIRES/Keck, which covered Mg II, several Fe II transitions, Mg I, and in some
cases (depending upon redshift), Ca II, Ti II, Mn II, and Al III. Ultraviolet,
lower resolution (~230 km/s) Faint Object Spectrograph data (1600 - 3275 Ang)
were obtained from the Hubble Space Telescope archive. These spectra covered Al
II, Al III, Si II, Si III, Si IV, C II, C III, C IV, N V, O VI, and several
Lyman series transitions, with coverage dependent upon the absorption system
redshift. From these data, we infer that Mg II absorbing galaxies at
intermediate redshifts have multiphase gaseous structures.Comment: Accepted: The Astrophysical Journa
Low and High Ionization Absorption Properties of Mg II Absorption-Selected Galaxies at Intermediate Redshifts. II. Taxonomy, Kinematics, and Galaxies
[Abridged] We examine a sample of 45 Mg II absorption-selected systems over
the redshift range 0.4 to 1.4. Mg II and Fe II absorption profiles were
observed at a resolution of ~6 km/s with HIRES/Keck. Lyman-alpha and C IV data
were measured in archival FOS/HST spectra (~230 km/s). We perform a
multivariate analysis of W(MgII), W(FeII), W(CIV) and W(Lya) (rest-frame)
equivalent widths and the Mg II kinematic spread. We find five categories of Mg
II absorbers: "Classic", "C IV-deficient", "Single/Weak", "Double", and
"DLA/HI-Rich". There is a strong connection between low-ionization kinematics
and the location of an absorber on the W(CIV)-W(MgII) plane. In most absorbers
a significant fraction of the C IV arises in a phase separate from Mg II. Many
of the C IV profiles are resolved in the FOS spectra due to velocity
structure.. For 16 galaxies, we compare the available absorption-line
properties (taken from Churchill et al. 2000, Paper I) to the galaxy properties
but find no significant (greater than 3-sigma) correlations, although several
suggestive trends are apparent. We compare the locations of our intermediate
redshift absorbers on the W(CIV)-W(MgII) plane with those of lower and higher
redshift data taken from the literature and find evidence for evolution that is
connected with the Mg II kinematics. We discuss the potential of using the
above categorizations of absorbers to understand the evolution in the
underlying physical processes giving rise to the gas and governing its
ionization phases and kinematics.Comment: Accepted: The Astrophysical Journal; Work based upon data presented
in Paper I [astro-ph/0005585
Precision measurement of the Dalitz plot distribution with the KLOE detector
Using fb of data collected with
the KLOE detector at DANE, the Dalitz plot distribution for the decay is studied with the world's largest sample of events. The Dalitz plot density is parametrized as a polynomial
expansion up to cubic terms in the normalized dimensionless variables and
. The experiment is sensitive to all charge conjugation conserving terms of
the expansion, including a term. The statistical uncertainty of all
parameters is improved by a factor two with respect to earlier measurements.Comment: 11 pages, 9 figures, supplement: an ascii tabl
Can One Trust Quantum Simulators?
Various fundamental phenomena of strongly-correlated quantum systems such as
high- superconductivity, the fractional quantum-Hall effect, and quark
confinement are still awaiting a universally accepted explanation. The main
obstacle is the computational complexity of solving even the most simplified
theoretical models that are designed to capture the relevant quantum
correlations of the many-body system of interest. In his seminal 1982 paper
[Int. J. Theor. Phys. 21, 467], Richard Feynman suggested that such models
might be solved by "simulation" with a new type of computer whose constituent
parts are effectively governed by a desired quantum many-body dynamics.
Measurements on this engineered machine, now known as a "quantum simulator,"
would reveal some unknown or difficult to compute properties of a model of
interest. We argue that a useful quantum simulator must satisfy four
conditions: relevance, controllability, reliability, and efficiency. We review
the current state of the art of digital and analog quantum simulators. Whereas
so far the majority of the focus, both theoretically and experimentally, has
been on controllability of relevant models, we emphasize here the need for a
careful analysis of reliability and efficiency in the presence of
imperfections. We discuss how disorder and noise can impact these conditions,
and illustrate our concerns with novel numerical simulations of a paradigmatic
example: a disordered quantum spin chain governed by the Ising model in a
transverse magnetic field. We find that disorder can decrease the reliability
of an analog quantum simulator of this model, although large errors in local
observables are introduced only for strong levels of disorder. We conclude that
the answer to the question "Can we trust quantum simulators?" is... to some
extent.Comment: 20 pages. Minor changes with respect to version 2 (some additional
explanations, added references...
Service users' perceptions of the effective ingredients in supported employment
Background: The UK government is advocating the use of supported employment to help people on incapacity benefits back to work, with an emphasis on Individual Placement and Support (IPS) models. However there is little UK-based evidence on the key ingredients of effective support.
Aim: To ascertain service users' views of what they found helpful about supported employment.
Method: Interviews were carried out with 182 people with severe and enduring mental health problems who were actively engaged with one of the six supported employment agencies included in the study.
Results: Three themes emerged: emotional support, practical assistance and a client-centred approach.
Conclusion: The findings highlight the importance of the quality of support, particularly through interpersonal dynamics, which go beyond the organizational features emphasized in the IPS model
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