9,285 research outputs found
A Bayesian Networks Approach to Operational Risk
A system for Operational Risk management based on the computational paradigm
of Bayesian Networks is presented. The algorithm allows the construction of a
Bayesian Network targeted for each bank using only internal loss data, and
takes into account in a simple and realistic way the correlations among
different processes of the bank. The internal losses are averaged over a
variable time horizon, so that the correlations at different times are removed,
while the correlations at the same time are kept: the averaged losses are thus
suitable to perform the learning of the network topology and parameters. The
algorithm has been validated on synthetic time series. It should be stressed
that the practical implementation of the proposed algorithm has a small impact
on the organizational structure of a bank and requires an investment in human
resources limited to the computational area
Touching moments: desire modulates the neural anticipation of active romantic caress
A romantic caress is a basic expression of affiliative behavior and a primary reinforcer. Given its inherent affective valence, its performance also would imply the prediction of reward values. For example, touching a person for whom one has strong passionate feelings likely is motivated by a strong desire for physical contact and associated with the anticipation of hedonic experiences. The present study aims at investigating how the anticipatory neural processes of active romantic caress are modulated by the intensity of the desire for affective contact as reflected by passionate feelings for the other. Functional magnetic resonance imaging scanning was performed in romantically involved partners using a paradigm that allowed to isolate the specific anticipatory representations of active romantic caress, compared with control caress, while testing for the relationship between neural activity and measures of feelings of passionate love for the other. The results demonstrated that right posterior insula activity in anticipation of romantic caress significantly co-varied with the intensity of desire for union with the other. This effect was independent of the sensory-affective properties of the performed touch, like its pleasantness. Furthermore, functional connectivity analysis showed that the same posterior insula cluster interacted with brain regions related to sensory-motor functions as well as to the processing and anticipation of reward. The findings provide insight on the neural substrate mediating between the desire for and the performance of romantic caress. In particular, we propose that anticipatory activity patterns in posterior insula may modulate subsequent sensory-affective processing of skin-to-skin contact
Targeting the DNA damage response to overcome cancer drug resistance in glioblastoma
Glioblastoma multiforme (GBM) is one of the most recalcitrant brain tumors characterized by a tumor microenvironment (TME) that strongly supports GBM growth, aggressiveness, invasiveness, and resistance to therapy. Importantly, a common feature of GBM is the aberrant activation of receptor tyrosine kinases (RTKs) and of their downstream signaling cascade, including the non-receptor tyrosine kinase SRC. SRC is a central downstream intermediate of many RTKs, which triggers the phosphorylation of many substrates, therefore, promoting the regulation of a wide range of different pathways involved in cell survival, adhesion, proliferation, motility, and angiogenesis. In addition to the aforementioned pathways, SRC constitutive activity promotes and sustains inflammation and metabolic reprogramming concurring with TME development, therefore, actively sustaining tumor growth. Here, we aim to provide an updated picture of the molecular pathways that link SRC to these events in GBM. In addition, SRC targeting strategies are discussed in order to highlight strengths and weaknesses of SRC inhibitors in GBM management, focusing our attention on their potentialities in combination with conventional therapeutic approaches (i.e., temozolomide) to ameliorate therapy effectiveness
Targeting the DNA damage response to overcome cancer drug resistance in glioblastoma
Glioblastoma multiforme (GBM) is one of the most recalcitrant brain tumors characterized by a tumor microenvironment (TME) that strongly supports GBM growth, aggressiveness, invasiveness, and resistance to therapy. Importantly, a common feature of GBM is the aberrant activation of receptor tyrosine kinases (RTKs) and of their downstream signaling cascade, including the non-receptor tyrosine kinase SRC. SRC is a central downstream intermediate of many RTKs, which triggers the phosphorylation of many substrates, therefore, promoting the regulation of a wide range of different pathways involved in cell survival, adhesion, proliferation, motility, and angiogenesis. In addition to the aforementioned pathways, SRC constitutive activity promotes and sustains inflammation and metabolic reprogramming concurring with TME development, therefore, actively sustaining tumor growth. Here, we aim to provide an updated picture of the molecular pathways that link SRC to these events in GBM. In addition, SRC targeting strategies are discussed in order to highlight strengths and weaknesses of SRC inhibitors in GBM management, focusing our attention on their potentialities in combination with conventional therapeutic approaches (i.e., temozolomide) to ameliorate therapy effectiveness
Simbol-X Background Minimization: Mirror Spacecraft Passive Shielding Trade-Off Study
The present work shows a quantitative trade-off analysis of the Simbol-X
Mirror Spacecraft (MSC) passive shielding, in the phase space of the various
parameters: mass budget, dimension, geometry, and composition. A simplified
physical (and geometrical) model of the sky screen, implemented by means of a
GEANT4 simulation, has been developed to perform a performance-driven mass
optimization and evaluate the residual background level on Simbol-X focal
plane.Comment: 3 pages, 6 figures, to appear in the proceedings of the second
Simbol-X International Symposium "Simbol-X - Focusing on the Hard X-ray
Universe", AIP Conf. Proc. Series, P. Ferrando and J. Rodriguez ed
Reach Out and Touch Someone: Anticipatory Sensorimotor Processes of Active Interpersonal Touch
Anticipating the sensorimotor consequences of an action for both self and other is fundamental for action coordination when individuals socially interact. Somatosensation constitutes an elementary component of social cognition and sensorimotor prediction, but its functions in active social behavior remain unclear. We hypothesized that the somatosensory system contributes to social haptic behavior as evidenced by specific anticipatory activation patterns when touching an animate target (human hand) compared with an inanimate target (fake hand). fMRI scanning was performed during a paradigm that allowed us to isolate the anticipatory representations of active interpersonal touch while controlling for nonsocial sensorimotor processes and possible confounds because of interpersonal relationships or socioemotional valence. Active interpersonal touch was studied both as skin-to-skin contact and as object-mediated touch. The results showed weaker deactivation in primary somatosensory cortex and medial pFC and stronger activation in cerebellum for the animate target, compared with the inanimate target, when intending to touch it with one's own hand. Differently, in anticipation of touching the human hand with an object, anterior inferior parietal lobule and lateral occipital-temporal cortex showed stronger activity. When actually touching a human hand with one's own hand, activation was stronger in medial pFC but weaker in primary somatosensory cortex. The findings provide new insight on the contribution of simulation and sensory prediction mechanisms to active social behavior. They also suggest that literally getting in touch with someone and touching someone by using an object might be approached by an agent as functionally distinct conditions
A novel trigger-based method for hydrothermal vents prospecting using an autonomous underwater robot
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Autonomous Robots 29 (2010): 67-83, doi:10.1007/s10514-010-9187-y.In this paper we address the problem of localizing active hydrothermal vents on the
seafloor using an Autonomous Underwater Vehicle (AUV). The plumes emitted by hydrothermal
vents are the result of thermal and chemical inputs from submarine hot spring systems into the
overlying ocean. The Woods Hole Oceanographic Institution's Autonomous Benthic Explorer
(ABE) AUV has successfully localized previously undiscovered hydrothermal vent fields in
several recent vent prospecting expeditions. These expeditions utilized the AUV for a three-stage,
nested survey strategy approach (German et al., 2008). Each stage consists of a survey flown at
successively deeper depths through easier to detect but spatially more constrained vent fluids.
Ideally this sequence of surveys culminates in photographic evidence of the vent fields themselves.
In this work we introduce a new adaptive strategy for an AUV's movement during the first,
highest-altitude survey: the AUV initially moves along pre-designed tracklines but certain
conditions can trigger an adaptive movement that is likely to acquire additional high value data for
vent localization. The trigger threshold is changed during the mission, adapting the method to the
different survey profiles the robot may find. The proposed algorithm is vetted on data from
previous ABE missions and measures of efficiency presented
Longitudinal coherence in thermal ghost imaging
We show theoretically and experimentally that lensless ghost imaging with thermal light is fully interpretable in terms of classical statistical optics. The disappearance of the ghost image when the object and the reference planes are located at different distances from the source is due to the fading out of the intensity-intensity cross correlation between the two planes. Thus the visibility and the resolution of the ghost image are determined by the longitudinal coherence of the speckle beam, and no quantum explanation is necessary.We show theoretically and experimentally that lensless ghost imaging with thermal light is fully interpretable in terms of classical statistical optics. The disappearance of the ghost image when the object and the reference planes are located at different distances from the source is due to the fading out of the intensity-intensity cross correlation between the two planes. Thus the visibility and the resolution of the ghost image are determined by the longitudinal coherence of the speckle beam, and no quantum explanation is necessary. \ua9 2008 American Institute of Physics
Estimation of intake and digestibility of kleingrass from in situ parameters measured in sheep
The voluntary intake and digestibility of kleingrass (Panicum coloratum cv. Verde) were measured in seven periods, comprising one full year. The forage was offered twice a day ad Iibitum to .seven rams, frtted with faces collection bags; each experimental period was composed of 8 days for adaptation and 8 days for collection of data. The dry matter (DM) Intake (DMI) varied from 36.1 to 64.9 glkg MO.75, the digestible dry-matter Intake (DDMI), from 17.4 to 41.9 glkg MO.75 and the in vivo dry matter apparent digestibility (DMD), from 0.471 to 0.667. Daily samples of offered forage were taken and pooled subsamples from each of the seven periods were incubated in nylon bags in the rumen of three Hereford steers. The data were fitted to the exponential equation: p= a + b (1-e~) to estimate p (the proportionate loss of DM at time t of incubation); effective degradability (ED) and lag time (L) were also estimated. The parameters obtained in situ were related to the in vivo results by simple and multiple regression. The correlation coefficients of the rate of degradation {9 and ED with DMI, DDMI and DMD were, respectively, 0.96 and 0.97; 0.97 and 0.96; 0.86 and 0.88. By including, Q, Q and k into a multiple regression analysis, the coefficients of determination (R2) were: DMI: 0.99; DDMI: 0.99 and DMD: 0.91. Within the conditions of this study, the parameters obtained in situ were reasonable estimators of voluntary intake and digestibility.Resúmenes de Trabajos presentados en otras publicaciones (por docentes de la UNLPam.) Publicado en Animal Science, 67: 535-540, 1998
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