1,676 research outputs found
Facing the music or burying our heads in the sand?: Adaptive emotion regulation in mid- and late-life
Psychological defense theories postulate that keeping threatening information out of awareness brings short-term reduction of anxiety at the cost of longer-term dysfunction. By contrast, Socioemotional Selectivity Theory suggests that preference for positively-valenced information is a manifestation of adaptive emotion regulation in later life. Using six decades of longitudinal data on 61 men, we examined links between emotion regulation indices informed by these distinct conceptualizations: defense patterns in earlier adulthood and selective memory for positively-valenced images in late life. Men who used more avoidant defenses in midlife recognized fewer emotionally-valenced and neutral images in a memory test 35-40 years later. Late-life satisfaction was positively linked with mid-life engaging defenses but negatively linked at the trend level with concurrent positivity bias
Multi-view Face Detection Using Deep Convolutional Neural Networks
In this paper we consider the problem of multi-view face detection. While
there has been significant research on this problem, current state-of-the-art
approaches for this task require annotation of facial landmarks, e.g. TSM [25],
or annotation of face poses [28, 22]. They also require training dozens of
models to fully capture faces in all orientations, e.g. 22 models in HeadHunter
method [22]. In this paper we propose Deep Dense Face Detector (DDFD), a method
that does not require pose/landmark annotation and is able to detect faces in a
wide range of orientations using a single model based on deep convolutional
neural networks. The proposed method has minimal complexity; unlike other
recent deep learning object detection methods [9], it does not require
additional components such as segmentation, bounding-box regression, or SVM
classifiers. Furthermore, we analyzed scores of the proposed face detector for
faces in different orientations and found that 1) the proposed method is able
to detect faces from different angles and can handle occlusion to some extent,
2) there seems to be a correlation between dis- tribution of positive examples
in the training set and scores of the proposed face detector. The latter
suggests that the proposed methods performance can be further improved by using
better sampling strategies and more sophisticated data augmentation techniques.
Evaluations on popular face detection benchmark datasets show that our
single-model face detector algorithm has similar or better performance compared
to the previous methods, which are more complex and require annotations of
either different poses or facial landmarks.Comment: in International Conference on Multimedia Retrieval 2015 (ICMR
Gravitational and axial anomalies for generalized Euclidean Taub-NUT metrics
The gravitational anomalies are investigated for generalized Euclidean
Taub-NUT metrics which admit hidden symmetries analogous to the Runge-Lenz
vector of the Kepler-type problem. In order to evaluate the axial anomalies,
the index of the Dirac operator for these metrics with the APS boundary
condition is computed. The role of the Killing-Yano tensors is discussed for
these two types of quantum anomalies.Comment: 23 page
Steroid modulation of neurogenesis: Focus on radial glial cells in zebrafish
International audienc
Quantitative test of the barrier nucleosome model for statistical positioning of nucleosomes up- and downstream of transcription start sites
The positions of nucleosomes in eukaryotic genomes determine which parts of
the DNA sequence are readily accessible for regulatory proteins and which are
not. Genome-wide maps of nucleosome positions have revealed a salient pattern
around transcription start sites, involving a nucleosome-free region (NFR)
flanked by a pronounced periodic pattern in the average nucleosome density.
While the periodic pattern clearly reflects well-positioned nucleosomes, the
positioning mechanism is less clear. A recent experimental study by Mavrich et
al. argued that the pattern observed in S. cerevisiae is qualitatively
consistent with a `barrier nucleosome model', in which the oscillatory pattern
is created by the statistical positioning mechanism of Kornberg and Stryer. On
the other hand, there is clear evidence for intrinsic sequence preferences of
nucleosomes, and it is unclear to what extent these sequence preferences affect
the observed pattern. To test the barrier nucleosome model, we quantitatively
analyze yeast nucleosome positioning data both up- and downstream from NFRs.
Our analysis is based on the Tonks model of statistical physics which
quantifies the interplay between the excluded-volume interaction of nucleosomes
and their positional entropy. We find that although the typical patterns on the
two sides of the NFR are different, they are both quantitatively described by
the same physical model, with the same parameters, but different boundary
conditions. The inferred boundary conditions suggest that the first nucleosome
downstream from the NFR (the +1 nucleosome) is typically directly positioned
while the first nucleosome upstream is statistically positioned via a
nucleosome-repelling DNA region. These boundary conditions, which can be
locally encoded into the genome sequence, significantly shape the statistical
distribution of nucleosomes over a range of up to ~1000 bp to each side.Comment: includes supporting materia
Ego defense mechanisms in Pakistani medical students: a cross sectional analysis
Background: Ego defense mechanisms (or factors), defined by Freud as unconscious resources used by the ego to reduce conflict between the id and superego, are a reflection of how an individual deals with conflict and stress. This study assesses the prevalence of various ego defense mechanisms employed by medical students of Karachi, which is a group with higher stress levels than the general population. Methods: A questionnaire based cross-sectional study was conducted on 682 students from five major medical colleges of Karachi over 4 weeks in November 2006. Ego defense mechanisms were assessed using the Defense Style Questionnaire (DSQ-40) individually and as grouped under Mature, Immature, and Neurotic factors. Results: Lower mean scores of Immature defense mechanisms (4.78) were identified than those for Neurotic (5.62) and Mature (5.60) mechanisms among medical students of Karachi. Immature mechanisms were more commonly employed by males whereas females employed more Neurotic mechanisms than males. Neurotic and Immature defenses were significantly more prevalent in first and second year students. Mature mechanisms were significantly higher in students enrolled in Government colleges than Private institutions (p \u3c 0.05). Conclusions: Immature defense mechanisms were less commonly employed than Neurotic and Mature mechanisms among medical students of Karachi. The greater employment of Neurotic defenses may reflect greater stress levels than the general population. Employment of these mechanisms was associated with female gender, enrollment in a private medical college, and students enrolled in the first 2 years of medical school
Algoritmo para la identificación y cálculo de coeficientes del sistema de ecuaciones diferenciales que modela la polimerización de la hemoglobina S
En este trabajo, dado un modelo que simula el proceso de polimerización de la hemoglobina S, se realiza el cálculo e identificaÂción de los coeficientes óptimos en correspondencia con datos obtenidos experimentalmente, aplicando el método del gradiente.
 
Algoritmo para la identificación y cálculo de coeficientes del sistema de ecuaciones diferenciales que modela la polimerización de la hemoglobina S
En este trabajo, dado un modelo que simula el proceso de polimerización de la hemoglobina S, se realiza el cálculo e identificaÂción de los coeficientes óptimos en correspondencia con datos obtenidos experimentalmente, aplicando el método del gradiente.Â
Palabras y frases claves: Algoritmo, sistema de ecuaciones diferenciales, polimerización, hemoglobina, aplicación medic
Use of a porous membrane for gas bubble removal in microfluidic channels: physical mechanisms and design criteria
We demonstrate and explain a simple and efficient way to remove gas bubbles
from liquid-filled microchannels, by integrating a hydrophobic porous membrane
on top of the microchannel. A prototype chip is manufactured in hard,
transparent polymer with the ability to completely filter gas plugs out of a
segmented flow at rates up to 7.4 microliter/s per mm2 of membrane area. The
device involves a bubble generation section and a gas removal section. In the
bubble generation section, a T-junction is used to generate a train of gas
plugs into a water stream. These gas plugs are then transported towards the gas
removal section, where they slide along a hydrophobic membrane until complete
removal. The system has been successfully modeled and four necessary operating
criteria have been determined to achieve a complete separation of the gas from
the liquid. The first criterion is that the bubble length needs to be larger
than the channel diameter. The second criterion is that the gas plug should
stay on the membrane for a time sufficient to transport all the gas through the
membrane. The third criterion is that the gas plug travel speed should be lower
than a critical value: otherwise a stable liquid film between the bubble and
the membrane prevents mass transfer. The fourth criterion is that the pressure
difference across the membrane should not be larger than the Laplace pressure
to prevent water from leaking through the membrane
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