1,823 research outputs found
Emotional dysfunction in schizophrenia spectrum psychosis: the role of illness perceptions
Background. Assessing illness perceptions has been useful in a range of medical disorders. This study of people with a recent relapse of their psychosis examines the relationship between illness perception, their emotional responses and their attitudes to medication.Method. One hundred patients diagnosed with a non-affective psychotic disorder were assessed within 3 months of relapse. Measures included insight, self-reported. illness perceptions, medication adherence, depression, self-esteem and anxiety.Results. Illness perceptions about psychosis explained 46, 36 and 34% of the variance in depression, anxiety and self-esteem respectively. However, self-reported medication adherence was more strongly associated with a measure of insight.Conclusions. Negative illness perceptions in psychosis are clearly related to depression, anxiety and self-esteem. These in turn have been linked to symptom maintenance and recurrence. Clinical interventions that foster appraisals of recovery rather than of chronicity and severity may therefore improve emotional well-being in people with psychosis. It might be better to address adherence to medication through direct attempts at helping them understand their need for treatment
Transdiagnostic Extension of Delusions: Schizophrenia and Beyond
Delusion is central to the conceptualization, definition, and identification of schizophrenia. However, in current classifications, the presence of delusions is neither necessary nor sufficient for the diagnosis of schizophrenia, nor is it sufficient to exclude the diagnosis of some other psychiatric conditions. Partly as a consequence of these classification rules, it is possible for delusions to exist transdiagnostically. In this article, we evaluate the extent to which this happens, and in what ways the characteristics of delusions vary according to diagnostic context. We were able to examine their presence and form in delusional disorder, affective disorder, obsessive-compulsive disorder, borderline personality disorder, and dementia, in all of which they have an appreciable presence. There is some evidence that the mechanisms of delusion formation are, at least to an extent, shared across these disorders. This transdiagnostic extension of delusions is an argument for targeting them therapeutically in their own right. However there is a dearth of research to enable the rational transdiagnostic deployment of either pharmacological or psychological treatments
ON COMPUTING UPPER LIMITS TO SOURCE INTENSITIES
A common problem in astrophysics is determining how bright a source could be
and still not be detected. Despite the simplicity with which the problem can be
stated, the solution involves complex statistical issues that require careful
analysis. In contrast to the confidence bound, this concept has never been
formally analyzed, leading to a great variety of often ad hoc solutions. Here
we formulate and describe the problem in a self-consistent manner. Detection
significance is usually defined by the acceptable proportion of false positives
(the TypeI error), and we invoke the complementary concept of false negatives
(the TypeII error), based on the statistical power of a test, to compute an
upper limit to the detectable source intensity. To determine the minimum
intensity that a source must have for it to be detected, we first define a
detection threshold, and then compute the probabilities of detecting sources of
various intensities at the given threshold. The intensity that corresponds to
the specified TypeII error probability defines that minimum intensity, and is
identified as the upper limit. Thus, an upper limit is a characteristic of the
detection procedure rather than the strength of any particular source and
should not be confused with confidence intervals or other estimates of source
intensity. This is particularly important given the large number of catalogs
that are being generated from increasingly sensitive surveys. We discuss the
differences between these upper limits and confidence bounds. Both measures are
useful quantities that should be reported in order to extract the most science
from catalogs, though they answer different statistical questions: an upper
bound describes an inference range on the source intensity, while an upper
limit calibrates the detection process. We provide a recipe for computing upper
limits that applies to all detection algorithms.Comment: 30 pages, 12 figures, accepted in Ap
Scintigraphic assessment of bone status at one year following hip resurfacing : comparison of two surgical approaches using SPECT-CT scan
Objectives: To study the vascularity and bone metabolism of the femoral head/neck following hip resurfacing arthroplasty, and to use these results to compare the posterior and the trochanteric-flip approaches.
Methods: In our previous work, we reported changes to intra-operative blood flow during hip resurfacing arthroplasty comparing two surgical approaches. In this study, we report the vascularity and the metabolic bone function in the proximal femur in these same patients at one year after the surgery. Vascularity and bone function was assessed using scintigraphic techniques. Of the 13 patients who agreed to take part, eight had their arthroplasty through a posterior approach and five through a trochanteric-flip approach.
Results: One year after surgery, we found no difference in the vascularity (vascular phase) and metabolic bone function (delayed phase) at the junction of the femoral head/neck between the two groups of patients. Higher radiopharmaceutical uptake was found in the region of the greater trochanter in the trochanteric-flip group, related to the healing osteotomy.
Conclusions: Our findings using scintigraphic techniques suggest that the greater intra-operative reduction in blood flow to the junction of the femoral head/neck, which is seen with the posterior approach compared with trochanteric flip, does not result in any difference in vascularity or metabolic bone function one year after surgery
Polarization of coalitions in an agent-based model of political discourse
Political discourse is the verbal interaction between political actors in a policy domain. This article explains the formation of polarized advocacy or discourse coalitions in this complex phenomenon by presenting a dynamic, stochastic, and discrete agent-based model based on graph theory and local optimization. In a series of thought experiments, actors compute their utility of contributing a specific statement to the discourse by following ideological criteria, preferential attachment, agenda-setting strategies, governmental coherence, or other mechanisms. The evolving macro-level discourse is represented as a dynamic network and evaluated against arguments from the literature on the policy process. A simple combination of four theoretical mechanisms is already able to produce artificial policy debates with theoretically plausible properties. Any sufficiently realistic configuration must entail innovative and path-dependent elements as well as a blend of exogenous preferences and endogenous opinion formation mechanisms
The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
The assembly process of our Galaxy can be retrieved using the motions and
chemistry of individual stars. Chemo-dynamical studies of the nearby halo have
long hinted at the presence of multiple components such as streams, clumps,
duality and correlations between the stars' chemical abundances and orbital
parameters. More recently, the analysis of two large stellar surveys have
revealed the presence of a well-populated chemical elemental abundance
sequence, of two distinct sequences in the colour-magnitude diagram, and of a
prominent slightly retrograde kinematic structure all in the nearby halo, which
may trace an important accretion event experienced by the Galaxy. Here report
an analysis of the kinematics, chemistry, age and spatial distribution of stars
in a relatively large volume around the Sun that are mainly linked to two major
Galactic components, the thick disk and the stellar halo. We demonstrate that
the inner halo is dominated by debris from an object which at infall was
slightly more massive than the Small Magellanic Cloud, and which we refer to as
Gaia-Enceladus. The stars originating in Gaia-Enceladus cover nearly the full
sky, their motions reveal the presence of streams and slightly retrograde and
elongated trajectories. Hundreds of RR Lyrae stars and thirteen globular
clusters following a consistent age-metallicity relation can be associated to
Gaia-Enceladus on the basis of their orbits. With an estimated 4:1 mass-ratio,
the merger with Gaia-Enceladus must have led to the dynamical heating of the
precursor of the Galactic thick disk and therefore contributed to the formation
of this component approximately 10 Gyr ago. These findings are in line with
simulations of galaxy formation, which predict that the inner stellar halo
should be dominated by debris from just a few massive progenitors.Comment: 19 pages, 8 figures. Published in Nature in the issue of Nov. 1st,
2018. This is the authors' version before final edit
Tacit knowledg and the problem of computer modelling cognitive processes in science
Once one has said that there is a “tacit dimension” of some sort to communication or to some cognitive activity, it seems like an appropriate step to make it a topic for research. The difficulty with this suggestion is that it assumes that in fact we have some sort of unproblematic mode of access to our implicit understandings, to the “tacit dimension.” To be sure, sometimes portions of this “dimension” are revealed to us, as when we find that others don’t share some procedure we follow “naturally” or habitually, or when we find ourselves in circumstances where these procedures fail, and we are forced to, and can, find replacements for them. But these are perhaps exceptional cases, revealed for us through contingent and possibly rare circumstances. And if this is so, it follows that a project of revealing the tacit dimension would depend on some premises that would give one some assurances that one’s techniques indeed reveal the necessary parts of it. It is one thing to have a method of turning over rocks to see if there are salamanders under them; it is another to form a project of counting all the salamanders in a given area, for one doesn’t know that they are all assessable by the known means
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