4,606 research outputs found
The experience of female patients seeking elective rhinoplasty surgery: a narrative inquiry
The aim of this research is to understand what motivates patients to have an elective rhinoplasty, taking into consideration any societal, familial, cultural and intrapersonal influences. The research question explored how, if at all, surgery impacts women’s embodied sense of themselves and if there is a way of providing psychological support to this patient group. Four female patients were interviewed preoperatively and postoperatively using a narrative inquiry approach. The research offers a detailed qualitative contribution in a field that is predominantly quantitatively studied. The research explored the nuances of why female patients want to have rhinoplasty surgery.
The narratives of the patients showed that the motivation to have surgery is based on external and internal factors. The external factors revealed the following: society’s acceptance of cosmetic surgery, the influence of the media, the experience of the consultation and how risk is understood. The internal factors were influenced by the patients’ experience of the death of significant family members, a need to separate from patriarchal and matriarchal family members, feelings of body shame, a fear of negative evaluation from others, and objectification of their body in preparation for surgery. Following surgery, a psychological shift was discussed by each patient; this indicates that cosmetic surgery does indeed have a psychological impact.
The implication for practice is that clinicians need to have a better understanding of the motivation of this patient group to be able to offer the appropriate psychological support. Awareness also needs to be raised with surgeons, to help them better understand how the surgery they perform can have a psychological impact. This research showed that patients proceeding with cosmetic surgery could benefit from having specialised psychological support preoperatively and postoperatively. This would contribute to more realistic expectations for surgery and, hopefully, a better outcome for both patient and surgeon
Revisiting Visual Question Answering Baselines
Visual question answering (VQA) is an interesting learning setting for
evaluating the abilities and shortcomings of current systems for image
understanding. Many of the recently proposed VQA systems include attention or
memory mechanisms designed to support "reasoning". For multiple-choice VQA,
nearly all of these systems train a multi-class classifier on image and
question features to predict an answer. This paper questions the value of these
common practices and develops a simple alternative model based on binary
classification. Instead of treating answers as competing choices, our model
receives the answer as input and predicts whether or not an
image-question-answer triplet is correct. We evaluate our model on the Visual7W
Telling and the VQA Real Multiple Choice tasks, and find that even simple
versions of our model perform competitively. Our best model achieves
state-of-the-art performance on the Visual7W Telling task and compares
surprisingly well with the most complex systems proposed for the VQA Real
Multiple Choice task. We explore variants of the model and study its
transferability between both datasets. We also present an error analysis of our
model that suggests a key problem of current VQA systems lies in the lack of
visual grounding of concepts that occur in the questions and answers. Overall,
our results suggest that the performance of current VQA systems is not
significantly better than that of systems designed to exploit dataset biases.Comment: European Conference on Computer Visio
Phase Diagram of alpha-Helical and beta-Sheet Forming Peptides
The intrinsic property of proteins to form structural motifs such as
alpha-helices and beta-sheets leads to a complex phase behavior in which
proteins can assemble into various types of aggregates including crystals,
liquidlike phases of unfolded or natively folded proteins, and amyloid fibrils.
Here we use a coarse-grained protein model that enables us to perform Monte
Carlo simulations for determining the phase diagram of natively folded
alpha-helical and unfolded beta-sheet forming peptides. The simulations reveal
the existence of various metastable peptide phases. The liquidlike phases are
metastable with respect to the fibrillar phases, and there is a hierarchy of
metastability
Bandit Models of Human Behavior: Reward Processing in Mental Disorders
Drawing an inspiration from behavioral studies of human decision making, we
propose here a general parametric framework for multi-armed bandit problem,
which extends the standard Thompson Sampling approach to incorporate reward
processing biases associated with several neurological and psychiatric
conditions, including Parkinson's and Alzheimer's diseases,
attention-deficit/hyperactivity disorder (ADHD), addiction, and chronic pain.
We demonstrate empirically that the proposed parametric approach can often
outperform the baseline Thompson Sampling on a variety of datasets. Moreover,
from the behavioral modeling perspective, our parametric framework can be
viewed as a first step towards a unifying computational model capturing reward
processing abnormalities across multiple mental conditions.Comment: Conference on Artificial General Intelligence, AGI-1
Concurrent bandits and cognitive radio networks
We consider the problem of multiple users targeting the arms of a single
multi-armed stochastic bandit. The motivation for this problem comes from
cognitive radio networks, where selfish users need to coexist without any side
communication between them, implicit cooperation or common control. Even the
number of users may be unknown and can vary as users join or leave the network.
We propose an algorithm that combines an -greedy learning rule with a
collision avoidance mechanism. We analyze its regret with respect to the
system-wide optimum and show that sub-linear regret can be obtained in this
setting. Experiments show dramatic improvement compared to other algorithms for
this setting
Colloidal crystal growth at externally imposed nucleation clusters
We study the conditions under which and how an imposed cluster of fixed
colloidal particles at prescribed positions triggers crystal nucleation from a
metastable colloidal fluid. Dynamical density functional theory of freezing and
Brownian dynamics simulations are applied to a two-dimensional colloidal system
with dipolar interactions. The externally imposed nucleation clusters involve
colloidal particles either on a rhombic lattice or along two linear arrays
separated by a gap. Crystal growth occurs after the peaks of the nucleation
cluster have first relaxed to a cutout of the stable bulk crystal.Comment: 4 pages, accepted for publication in Phys. Rev. Let
W49A North - Global or Local or No Collapse?
We attempt to fit observations with 5" resolution of the J=2-1 transition of
CS in the directions of H II regions A, B, and G of W49A North as well as
observations with 20" resolution of the J=2-1, 3-2, 5-4, and 7-6 transitions in
the directions of H II regions A and G by using radiative transfer
calculations. These calculations predict the intensity profiles resulting from
several spherical clouds along the line of sight. We consider three models:
global collapse of a very large (5 pc radius) cloud, localized collapse from
smaller (1 pc) clouds around individual H II regions, and multiple, static
clouds. For all three models we can find combinations of parameters that
reproduce the CS profiles reasonably well provided that the component clouds
have a core-envelope structure with a temperature gradient. Cores with high
temperature and high molecular hydrogen density are needed to match the higher
transitions (e.g. J=7-6) observed towards A and G. The lower temperature, low
density gas needed to create the inverse P-Cygni profile seen in the CS J=2-1
line (with 5" beam) towards H II region G arises from different components in
the 3 models. The infalling envelope of cloud G plus cloud B creates the
absorption in global collapse, cloud B is responsible in local collapse, and a
separate cloud, G', is needed in the case of many static clouds. The exact
nature of the velocity field in the envelopes for the case of local collapse is
not important as long as it is in the range of 1 to 5 km/s for a turbulent
velocity of about 6 km/s. High resolution observations of the J=1-0 and 5-4
transitions of CS and C34S may distinguish between these three models. Modeling
existing observations of HCO+ and C18O does not allow one to distinguish
between the three models but does indicate the existence of a bipolar outflow.Comment: 42 pages, 27 figures, accepted for publication in the ApJS August
2004, v153 issu
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