Search results for "Computer Science Application"
showing 10 items of 3998 documents
A finite element-based machine learning approach for modeling the mechanical behavior of the breast tissues under compression in real-time
2017
[EN] This work presents a data-driven method to simulate, in real-time, the biomechanical behavior of the breast tissues in some image-guided interventions such as biopsies or radiotherapy dose delivery as well as to speed up multimodal registration algorithms. Ten real breasts were used for this work. Their deformation due to the displacement of two compression plates was simulated off-line using the finite element (FE) method. Three machine learning models were trained with the data from those simulations. Then, they were used to predict in real-time the deformation of the breast tissues during the compression. The models were a decision tree and two tree-based ensemble methods (extremely…
Knockdown of NANOG Reduces Cell Proliferation and Induces G0/G1 Cell Cycle Arrest in Human Adipose Stem Cells
2019
The core components of regenerative medicine are stem cells with high self-renewal and tissue regeneration potentials. Adult stem cells can be obtained from many organs and tissues. NANOG, SOX2 and OCT4 represent the core regulatory network that suppresses differentiation-associated genes, maintaining the pluripotency of mesenchymal stem cells. The roles of NANOG in maintaining self-renewal and undifferentiated status of adult stem cells are still not perfectly established. In this study we define the effects of downregulation of NANOG in maintaining self-renewal and undifferentiated state in mesenchymal stem cells (MSCs) derived from subcutaneous adipose tissue (hASCs). hASCs were expanded…
A semi-automatic approach for epicardial adipose tissue segmentation and quantification on cardiac CT scans
2019
Abstract Many studies have shown that epicardial fat is associated with a higher risk of heart diseases. Accurate epicardial adipose tissue quantification is still an open research issue. Considering that manual approaches are generally user-dependent and time-consuming, computer-assisted tools can considerably improve the result repeatability as well as reduce the time required for performing an accurate segmentation. Unfortunately, fully automatic strategies might not always identify the Region of Interest (ROI) correctly. Moreover, they could require user interaction for handling unexpected events. This paper proposes a semi-automatic method for Epicardial Fat Volume (EFV) segmentation a…
Is Cybervictimization Associated with Body Dissatisfaction, Depression, and Eating Disorder Psychopathology?
2018
Studies carried out in nonclinical samples have found an association between cyberbullying victimization and eating disorder (ED) psychopathology (negative emotions, low self-esteem, unhealthy eating behaviors, and body dissatisfaction); however, these previous studies were carried out with participants without an ED diagnosis. To extend the knowledge in this area of research, we aim to confirm these associations in two different samples: on the one hand, a sample composed of participants with ED diagnoses and, on the other hand, a sample composed of participants at high risk of ED. In study 1, the sample was composed of 80 participants diagnosed with EDs: 41.2 percent, n = 33, matched buli…
The Positive Side of Social Comparison on Social Network Sites: How Envy Can Drive Inspiration on Instagram
2018
A growing body of research finds social network sites (SNS) such as Instagram to facilitate social comparison and the emotional experience of envy in everyday life, with harmful effects for users' well-being. Yet, previous research has exclusively focused on the negative side of social comparison and envy on SNS. Thereby, it has neglected two important aspects: (a) comparison processes can also elicit a beneficial emotional reaction to other users' online self-presentations (i.e., benign envy) and, thus, (b) comparisons can be motivating, with positive outcomes for well-being. The present study aims at closing this research gap by investigating how social comparisons and envy on SNS are rel…
Prediction of the hemoglobin level in hemodialysis patients using machine learning techniques
2013
HighlightsDifferent prediction algorithms were used to predict Hb levels in CRF patients.Prediction errors in the validation cohorts of patients were around 0.6g/dl.Difficulty to obtain lower errors due to the measuring machine precision (0.2g/dl).Relevance analysis of features have been applied for each predictor. Patients who suffer from chronic renal failure (CRF) tend to suffer from an associated anemia as well. Therefore, it is essential to know the hemoglobin (Hb) levels in these patients. The aim of this paper is to predict the hemoglobin (Hb) value using a database of European hemodialysis patients provided by Fresenius Medical Care (FMC) for improving the treatment of this kind of …
Virtual reality treatment of flying phobia.
2002
Flying phobia (FP) might become a very incapacitating and disturbing problem in a person's social, working, and private areas. Psychological interventions based on exposure therapy have proved to be effective, but given the particular nature of this disorder they bear important limitations. Exposure therapy for FP might be excessively costly in terms of time, money, and efforts. Virtual reality (VR) overcomes these difficulties as different significant environments might be created, where the patient can interact with what he or she fears while in a totally safe and protected environment, the therapist's consulting room. This paper intends, on one hand, to show the different scenarios desig…
Biomechanical implications of excessive endograft protrusion into the aortic arch after thoracic endovascular repair
2015
Endografts placed in the aorta for thoracic endovascular aortic repair (TEVAR) may determine malappositioning to the lesser curvature of the aortic wall, thus resulting in a devastating complication known as endograft collapse. This premature device failure commonly occurs in young individuals after TEVAR for traumatic aortic injuries as a result of applications outside the physical conditions for which the endograft was designed. In this study, an experimentally-calibrated fluid-structure interaction (FSI) model was developed to assess the hemodynamic and stress/strain distributions acting on the excessive protrusion extension (PE) of endografts deployed in four young patients underwent TE…
Path Following in Non-Visual Conditions.
2018
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Suppression of the cardiac electric field artifact from the heart action evoked potential
2006
The study of heart action-related brain potentials is strongly disrupted by the presence of an inherent cardiac electric artifact. The hypothesis is presented that most of the electric current coupled to the cardiac field surrounds the skull and flows through the scalp tissue without crossing the cranial cavity. This pseudo two-dimensional conduction model contrasts with the volumetric conduction of the brain electrical activity, and this property is exploited to cancel the cardiac electric artifact. QRS loop vector-cardiographic projections on saggital planes were recorded in 11 healthy subjects in the head and neck areas. Comparative analysis of the projection eccentricities, estimated by…