48 results on '"Mahdi Imani"'
Search Results
2. Graph-Based Bayesian Optimization for Large-Scale Objective-Based Experimental Design
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Seyede Fatemeh Ghoreishi and Mahdi Imani
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Hyperparameter ,Class (computer programming) ,Mathematical optimization ,Computer Networks and Communications ,Computer science ,Process (engineering) ,Bayesian optimization ,Bayes Theorem ,Computer Science Applications ,symbols.namesake ,Research Design ,Artificial Intelligence ,Scalability ,symbols ,Graph (abstract data type) ,Design process ,Computer Simulation ,Gene Regulatory Networks ,Neural Networks, Computer ,Gaussian process ,Software - Abstract
Design is an inseparable part of most scientific and engineering tasks, including real and simulation-based experimental design processes and parameter/hyperparameter tuning/optimization. Several model-based experimental design techniques have been developed for design in domains with partial available knowledge about the underlying process. This article focuses on a powerful class of model-based experimental design called the mean objective cost of uncertainty (MOCU). The MOCU-based techniques are objective-based, meaning that they take the main objective of the process into account during the experimental design process. However, the lack of scalability of MOCU-based techniques prevents their application to most practical problems, including large discrete or combinatorial spaces. To achieve a scalable objective-based experimental design, this article proposes a graph-based MOCU-based Bayesian optimization framework. The correlations among samples in the large design space are accounted for using a graph-based Gaussian process, and an efficient closed-form sequential selection is achieved through the well-known expected improvement policy. The proposed framework's performance is assessed through the structural intervention in gene regulatory networks, aiming to make the network away from the states associated with cancer.
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- 2022
3. Two-Stage Bayesian Optimization for Scalable Inference in State-Space Models
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Seyede Fatemeh Ghoreishi and Mahdi Imani
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Dynamical systems theory ,Computer Networks and Communications ,Computer science ,Bayesian optimization ,Computational Biology ,Inference ,Bayes Theorem ,Parameter space ,Computer Science Applications ,Artificial Intelligence ,A priori and a posteriori ,State space ,Neural Networks, Computer ,Linear combination ,Particle filter ,Algorithm ,Space Simulation ,Software ,Probability - Abstract
State-space models (SSMs) are a rich class of dynamical models with a wide range of applications in economics, healthcare, computational biology, robotics, and more. Proper analysis, control, learning, and decision-making in dynamical systems modeled by SSMs depend on the accuracy of the inferred/learned model. Most of the existing inference techniques for SSMs are capable of dealing with very small systems, unable to be applied to most of the large-scale practical problems. Toward this, this article introduces a two-stage Bayesian optimization (BO) framework for scalable and efficient inference in SSMs. The proposed framework maps the original large parameter space to a reduced space, containing a small linear combination of the original space. This reduced space, which captures the most variability in the inference function (e.g., log likelihood or log a posteriori), is obtained by eigenvalue decomposition of the covariance of gradients of the inference function approximated by a particle filtering scheme. Then, an exponential reduction in the search space of parameters during the inference process is achieved through the proposed two-stage BO policy, where the solution of the first-stage BO policy in the reduced space specifies the search space of the second-stage BO in the original space. The proposed framework's accuracy and speed are demonstrated through several experiments, including real metagenomics data from a gut microbial community.
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- 2022
4. Bayesian Optimization for Expensive Smooth-Varying Functions
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Mahdi Imani, Mohsen Imani, and Seyede Fatemeh Ghoreishi
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Artificial Intelligence ,Computer Networks and Communications - Published
- 2022
5. Modeling the Structural Relationships Between Trauma Experience with Substance Use Tendency, Depression Symptoms, and Suicidal Thoughts in Individuals with Earthquake Trauma Experience: The Mediatory Role of Peritraumatic Dissociation and Experiential Avoidance
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Farshad Ahmadi, Mohammad Ali Goodarzi, Mohammad Reza Taghavi, and Mahdi Imani
- Abstract
Background: A significant portion of studies are mainly focused on the formation of post-traumatic stress disorder (PTSD) after earthquake trauma. This is while earthquakes are associated with a wide range of psychological reactions. In addition, other factors play a critical role in the formation of a diverse range of mental problems - personal characteristics, the severity of exposure to earthquake, and post-earthquake psychological distress (e.g., dissociation and avoidance). Therefore, This study investigates the relationship between earthquake intensity experience with substance use tendency, depression, and suicidal thoughts with the mediating role of peritraumatic dissociation and experiential avoidance. Methods: The participants consist of 323 individuals who had experienced an earthquake disaster four years ago. A set of valid and reliable questionnaires was administered to the participants. The gathered data were analyzed using structural equation modeling in SPSS Ver. 24 and LISREL Ver. 24. Results: The results showed that the intensity of the trauma experience is directly and significantly associated with depression symptoms, peritraumatic dissociation, and experiential avoidance. The experience of trauma had a significant indirect effect on the tendency to use substance through experimental avoidance. This is while the severity of the trauma experience did not directly correlate with substance use and suicidal thoughts. In addition, peritraumatic dissociation did not mediate the relationship between the severity of trauma experience with substance use, depression, and suicidal thoughts. Conclusions: It seems that both the experience (severity) of earthquake trauma and some reactions by individuals after a trauma experience can contribute to the prediction of some psychological consequences. These findings indicate the significance of experiential avoidance in predicting substance use tendencies. Nonetheless, to draw a clearer picture of peritraumatic dissociation, future research should focus on measuring this component more precisely and the inclusion of constructs that are naturally dissociative.
- Published
- 2023
6. Impaired complex theory of mind and low emotional self-awareness in outpatients with borderline personality disorder compared to healthy controls: A cross-sectional study
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Mohammad Ali Goodarzi, Mahdi Imani, Parisa Pourmohammad, and Mahdi Reza Sarafraz
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Adult ,medicine.diagnostic_test ,Emotions ,Theory of Mind ,Wechsler Adult Intelligence Scale ,medicine.disease ,behavioral disciplines and activities ,Psychiatry and Mental health ,Toronto Alexithymia Scale ,Cross-Sectional Studies ,Alexithymia ,Borderline Personality Disorder ,Social cognition ,Theory of mind ,Outpatients ,mental disorders ,medicine ,Memory span ,Humans ,Faux pas ,Affective Symptoms ,Psychology ,Borderline personality disorder ,Biological Psychiatry ,Clinical psychology - Abstract
Studies on the theory of mind (TOM) and alexithymia in borderline personality disorder (BPD) have yielded inconsistent results. Also, the relationship between TOM abilities and alexithymia facets as two domains of social cognition has not been studied in BPD. This study aimed to fill this gap. Participants were 50 outpatients with BPD and 50 age and gender-matched healthy controls. Assessments performed using Reading the Mind in Eyes Task (RMET), Toronto Alexithymia Scale (TAS-20), Faux Pas Task (FPT), and Digit Span subtest of Wechsler Adult Intelligence Scale. Results showed that BPD patients scored lower on overall FPT (p .001) and its cognitive (p .001) and affective TOM (p .001) subtests but were comparable with healthy controls in emotion recognition ability assessed by RMET (p = .241). The BPD group also scored significantly lower in overall alexithymia (p .001) and subscales of difficulty identifying feelings (DIF; p .001) and difficulty describing emotions (DDF; p = .001). However, they performed similarly to the healthy control group in externally oriented thinking (EOT; p = .164). Correlation analysis revealed a significant negative correlation between EOT and RMET in the BPD group (r = -0.33, p .05). No association, however, was found between FPT and RMET. This study suggests that BPD patients are impaired in the complex TOM abilities and have lower self-awareness of emotions, but their recognition of others' emotions is intact. Also, the results demonstrate that a heightened level of EOT is associated with difficulties in facial emotion recognition in BPD patients.
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- 2021
7. Personal distress mediates the relationship between childhood trauma and interpersonal vulnerabilities in individuals with borderline personality disorder
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Parisa Pourmohammad, Mahdi Imani, and Mohammad Ali Goodarzi
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General Psychology - Published
- 2022
8. Heterogeneous Sensing and Bayesian Optimization for Smart Calibration in Additive Manufacturing Process
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Sean Rescsanski, Mahdi Imani, and Farhad Imani
- Abstract
Fused Filament Fabrication (FFF) is an extrusion-based additive manufacturing process that utilizes a filament material melted through a hot end extruder to generate a component. Despite the great potential of the process to drastically reduce time-to-produce, cost and material waste for the creation of geometrically complex components, the presence of diverse defects deteriorate the quality of the final build. Defects in FFF (e.g., voids, stringing, and varying track width) are primarily linked to improper calibration of parameters, including feed speed, extrusion speed, extruder temperature, and build plate temperature. Trial and error is the most common practice implemented to manually offset baseline parameters using an array of components generated with varying process parameters. However, fabrication with manual adjustment not only is time consuming, but also leads to a suboptimal solution that jeopardizes the strength and integrity of the generated components. We propose a novel Bayesian Optimization (BO) methodology in conjunction with heterogeneous sensing to determine optimal process parameters with a minimum number of experiments. BO consists of two steps: First, a Gaussian Process as a surrogate model that maps the relationship between controllable parameters (e.g., feed rate/flow rate ratio, extrusion temperature, and layer height) and build quality (i.e., the objective function that is derived from sensing data). Second, an acquisition function is defined from this surrogate to decide where to sample. We design build quality characterization model that formulated as an objective-scoring algorithm that returns the proportion of the effective specimen sensor measurements divided by the desired values. The experimental results on real-world case study shows that the proposed BO is capable of determining the values for parameters in just 7 steps with quality improvement of 0.036 from the best trial quality.
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- 2022
9. Validation of a Semiautomatic Image Analysis Software for the Quantification of Musculoskeletal Tissues
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Jane A. Cauley, Ebrahim Bani Hassan, Mahdi Imani, Aaron Samuel Tze Nor Ch'Ng, Sara Vogrin, Gustavo Duque, and Nancy E Lane
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Sarcopenia ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Clinical Sciences ,Osteoporosis ,Biomedical Engineering ,Fat infiltration ,Adipose tissue ,Bioengineering ,Human study ,Article ,Endocrinology & Metabolism ,Computer-Assisted ,Endocrinology ,Image processing ,Image Processing, Computer-Assisted ,Genetics ,medicine ,Animals ,Humans ,Orthopedics and Sports Medicine ,Femur ,Image analysis ,Observer Variation ,Semiautomatic segmentation ,business.industry ,Human Genome ,Reproducibility of Results ,Intramuscular fat ,X-Ray Microtomography ,medicine.disease ,Marrow adipose tissue ,Cross-Sectional Studies ,Musculoskeletal ,Osteosarcopenia ,Orthopedic surgery ,Biochemistry and Cell Biology ,Nuclear medicine ,business ,Software - Abstract
Background: Accurate quantification of bone, muscle, and their components is still an unmet need in the musculoskeletal field. Current methods to quantify tissue volumes in 3D images are expensive, labor-intensive, and time-consuming; thus, a reliable, valid, and quick application is highly needed.Methods: Tissue Compass is a standalone software for semiautomatic segmentation and automatic quantification of musculoskeletal organs. To validate the software, cross-sectional micro-CT scans images of rat femur (n=19), and CT images of hip and abdomen (n=100) from the Osteoporotic Fractures in Men (MrOS) Study were used to quantify bone, hematopoietic marrow (HBM), and marrow adipose tissue (MAT) using commercial manual software as a comparator. Also, abdominal CT scans (n=100) were used to quantify psoas muscle volumes and intermuscular adipose tissue (IMAT) using the same software. We calculated Pearson's correlation coefficients, individual intra-class correlation coefficients (ICC), and Bland-Altman limits of agreement together with Bland-Altman plots to show the inter- and intra-observer agreement between Tissue Compass and commercially available software.Results: In the animal study, the agreement between Tissue Compass and commercial software was r>0.93 and ICC>0.93 for rat femur measurements. Bland-Altman limits of agreement was -720.89 (-1.5e+04, 13074.00) for MAT, 4421.11 (-1.8e+04, 27149.73) for HBM and -6073.32 (-2.9e+04, 16388.37) for bone. The inter-observer agreement for QCT human study between two observers was r>0.99 and ICC>0.99. Bland-Altman limits of agreement was 0.01 (-0.07, 0.10) for MAT in hip, 0.02 (-0.08, 0.12) for HBM in hip, 0.05 (-0.15, 0.25) for bone in hip, 0.02 (-0.18, 0.22) for MAT in L1, 0.00 (-0.16, 0.16) for HBM in L1, 0.02 (-0.23, 0.27) for bone in L1. The intra-observer agreement for QCT human study between two applications was r>0.997 and ICC>0.99. Bland-Altman limits of agreement was 0.03 (-0.13, 0.20) for MAT in hip, 0.05 (-0.08, 0.18) for HBM in hip, 0.05 (-0.24, 0.34) for bone in hip, -0.02 (-0.34, 0.31) for MAT in L1, -0.14 (-0.44, 0.17) for HBM in L1, -0.29 (-0.62, 0.05) for bone in L1, 0.03 (-0.08, 0.15) for IMAT in psoas, and 0.02 (-0.35, 0.38) for muscle in psoas. Conclusion: Compared to a conventional application, Tissue Compass demonstrated high accuracy and non-inferiority while also facilitating easier analyses. Tissue Compass could become the tool of choice to diagnose tissue loss/gain syndromes in the future by requiring a small number of CT sections to detect tissue volumes and fat infiltration.
- Published
- 2021
10. BioHD
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Zhuowen Zou, Hanning Chen, Prathyush Poduval, Yeseong Kim, Mahdi Imani, Elaheh Sadredini, Rosario Cammarota, and Mohsen Imani
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- 2022
11. Optimal Bayesian Biomarker Selection for Gene Regulatory Networks under Regulatory Model Uncertainty
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Mahdi Imani, Mohsen Imani, and Seyede Fatemeh Ghoreishi
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- 2022
12. Optimal Finite-Horizon Perturbation Policy for Inference of Gene Regulatory Networks
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Mahdi Imani and Seyede Fatemeh Ghoreishi
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Mathematical optimization ,Computer Networks and Communications ,Computer science ,Systems biology ,Numerical analysis ,Gene regulatory network ,Intelligent decision support system ,Inference ,Perturbation (astronomy) ,02 engineering and technology ,Artificial Intelligence ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Observability ,Time point - Abstract
A major goal of systems biology is to model accurately the complex dynamical behavior of gene regulatory networks (GRNs). Despite several advancements that have been made in inference of GRNs, two main issues continue to make the problem challenging: 1) nonidentifiability of parameters and 2) limited amounts of data. Thus, it becomes necessary to experimentally perturb or excite the system into different states. This perturbation process disrupts the expression of genes from active to inactive, or vice versa, at each time point. Another issue is the partial observability of the gene states, which must be inferred indirectly from noisy gene expression measurements. In this article, this latter issue is accounted for by employing the partially observed Boolean dynamical system signal model for the data and applying optimal state estimation. Then, the optimal finite-horizon perturbation policy is derived to achieve the highest possible expected performance for the maximum a posteriori estimator under a small perturbation cost. Performance is assessed through numerical experiments using the well-known p53-MDM2 negative-feedback loop regulatory model and synthetic GRNs.
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- 2021
13. Contributors
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Kate Anderson, Rahul D. Barmanray, Alison Beauchamp, Dario Boschiero, Sharon L. Brennan-Olsen, Cathleen Colón-Emeric, Natanael Perez Cordero, Selma Cvijetic, Andrea L. Darling, Larry Dian, Rachel L. Duckham, Gustavo Duque, Joshua N. Farr, Jack Feehan, Sadanand Fulzele, Ali Ghasem-Zadeh, Jennifer C. Gilman, Ebrahim Bani Hassan, William D. Hill, Eisuke Hiruma, Yushu Huang, Jasminka Z. Ilich, Mahdi Imani, David Karasik, Japneet Kaur, Owen J. Kelly, Iryna Khrystoforova, Peter Lee, Sean X. Leng, Yukang Li, Ching-Ti Liu, Brian Alexander MacDonald, Fatemeh Malekipour, Hossein Mokhtarzadeh, Ahmed M. Negm, Jordan O’Connor, Alexandra Papaioannou, Naaz Parmar, Patricia V. Schoenlein, Kenneth Ladd Seldeen, Neema Sharda, Charikleia Stefanaki, Bruce Robert Troen, Debra L. Waters, and Christopher J. Yates
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- 2022
14. Diagnosis of osteosarcopenia—Imaging
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Ebrahim Bani Hassan, Mahdi Imani, and Ali Ghasem-Zadeh
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- 2022
15. Evaluation of Family Relations, Self-control and Alexithamia as the Predictors of Anorexia Nervosa
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milad sharafi zadegan, farzaneh ebrahimi, Mahdi Imani, and reihaneh moniri
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Family relations ,Anorexia nervosa (differential diagnoses) ,media_common.quotation_subject ,Self-control ,Psychology ,Clinical psychology ,media_common - Published
- 2020
16. Bone Marrow Adipose Tissue Quantification by Imaging
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David W. Wright, Gustavo Duque, Ebrahim Bani Hassan, Ali Ghasem-Zadeh, Tara Sepehrizadeh, Numan Kutaiba, and Mahdi Imani
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Anemia ,Endocrinology, Diabetes and Metabolism ,Adipose tissue ,030209 endocrinology & metabolism ,Inflammation ,Bone and Bones ,03 medical and health sciences ,Paracrine signalling ,0302 clinical medicine ,Insulin resistance ,Bone Marrow ,medicine ,Animals ,Humans ,Endocrine system ,business.industry ,Organ Size ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,medicine.anatomical_structure ,Adipose Tissue ,Lipotoxicity ,Bone marrow ,medicine.symptom ,Tomography, X-Ray Computed ,business - Abstract
The significance and roles of marrow adipose tissue (MAT) are increasingly known, and it is no more considered a passive fat storage but a tissue with significant paracrine and endocrine activities that can cause lipotoxicity and inflammation. Changes in the MAT volume and fatty acid composition appear to drive bone and hematopoietic marrow deterioration, and studying it may open new horizons to predict bone fragility and anemia development. MAT has the potential to negatively impact bone volume and strength through several mechanisms that are partially described by inflammaging and lipotoxicity terminology. Evidence indicates paramount importance of MAT in age-associated decline of bone and red marrow structure and function. Currently, MAT measurement is being tested and validated by several techniques. However, purpose-specific adaptation of existing imaging technologies and, more importantly, development of new modalities to quantitatively measure MAT are yet to be done.
- Published
- 2019
17. Intermittent fasting and continuous energy restriction result in similar changes in body composition and muscle strength when combined with a 12 week resistance training program
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Stephen J. Keenan, Matthew B. Cooke, Ebrahim Bani Hassan, Won Sun Chen, Josef Sullivan, Sam X. Wu, Doa El-Ansary, Mahdi Imani, and Regina Belski
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Nutrition and Dietetics ,Body Weight ,Body Composition ,Medicine (miscellaneous) ,Humans ,Resistance Training ,Fasting ,Muscle Strength - Abstract
Purpose The objective of this study was to compare the effects of 12 weeks of resistance training combined with either 5:2 intermittent fasting or continuous energy restriction on body composition, muscle size and quality, and upper and lower body strength. Methods Untrained individuals undertook 12 weeks of resistance training plus either continuous energy restriction [20% daily energy restriction (CERT)] or 5:2 intermittent fasting [~ 70% energy restriction 2 days/week, euenergetic consumption 5 days/week (IFT)], with both groups prescribed a mean of ≥ 1.4 g of protein per kilogram of body weight per day. Participants completed 2 supervised resistance and 1 unsupervised aerobic/resistance training combination session per week. Changes in lean body mass (LBM), thigh muscle size and quality, strength and dietary intake were assessed. Results Thirty-four participants completed the study (CERT = 17, IFT = 17). LBM was significantly increased (+ 3.7%, p p p Conclusion When combined with resistance training and moderate protein intake, continuous energy restriction and 5:2 intermittent fasting resulted in similar improvements in body composition, muscle quality, and strength. ACTRN: ACTRN12620000920998, September 2020, retrospectively registered.
- Published
- 2021
18. Adaptive Real-Time Filter for Partially-Observed Boolean Dynamical Systems
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Mahdi Imani and Seyede Fatemeh Ghoreishi
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Adaptive filter ,Nonlinear system ,Noise measurement ,Dynamical systems theory ,Computer science ,Estimation theory ,Adaptive system ,Kalman filter ,Filter (higher-order function) ,Algorithm - Abstract
Partially-Observed Boolean dynamical systems (POBDS) are a general class of nonlinear state-space models consisting of a hidden Boolean state process observed through an arbitrary noisy mapping to a measurement space. The huge uncertainty present in systems/processes, along with the time-limit constraints, necessitate real-time or online joint state and parameter estimation of POBDS. In this manuscript, we present a real-time joint state and parameter estimation framework for POBDS. The proposed framework relies on a complete-sufficient statistic of parameters, where a joint state and parameter estimation is achieved based on the combination of online expectation-maximization method and the optimal MMSE state estimator for POBDS, called Boolean Kalman filter. The proposed method’s performance is assessed through a POBDS model for Boolean gene regulatory networks observed through noisy measurements.
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- 2021
19. Partially-Observed Discrete Dynamical Systems
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Seyede Fatemeh Ghoreishi and Mahdi Imani
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State variable ,Dynamical systems theory ,Noise measurement ,Computer science ,Maximum a posteriori estimation ,Estimator ,Time series ,Hidden Markov model ,Algorithm ,Data modeling - Abstract
This paper introduces a new signal model called partially-observed discrete dynamical systems (PODDS). This signal model is a special case of the hidden Markov model (HMM), where the state is a vector containing the information of different components of the system, and each component takes its value from a finite real-valued set. This signal model is currently treated as a finite-state HMM, where maximum a posteriori (MAP) criterion is used for state estimator purpose. This paper takes advantage of the discrete structure of the state variables in PODDS and develops the optimal componentwise MAP (CMAP) state estimator, which yields the MAP solution in each state variable. A fully-recursive process is provided for computation of this optimal estimator, followed by introducing a specific instance of the PODDS model suitable for regulatory networks observed through noisy time series data. The high performance of the proposed estimator is demonstrated by numerical experiments with a PODDS model of random regulatory networks.
- Published
- 2021
20. MFBO-SSM: Multi-Fidelity Bayesian Optimization for Fast Inference in State-Space Models
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Ulisses Braga-Neto, Douglas Allaire, Mahdi Imani, and Seyede Fatemeh Ghoreishi
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Dynamical systems theory ,Computer science ,Estimation theory ,Bayesian optimization ,Inference ,Sampling (statistics) ,General Medicine ,Parameter space ,Statistics::Computation ,Nonlinear system ,State space ,Likelihood function ,Particle filter ,Algorithm - Abstract
Nonlinear state-space models are ubiquitous in modeling real-world dynamical systems. Sequential Monte Carlo (SMC) techniques, also known as particle methods, are a well-known class of parameter estimation methods for this general class of state-space models. Existing SMC-based techniques rely on excessive sampling of the parameter space, which makes their computation intractable for large systems or tall data sets. Bayesian optimization techniques have been used for fast inference in state-space models with intractable likelihoods. These techniques aim to find the maximum of the likelihood function by sequential sampling of the parameter space through a single SMC approximator. Various SMC approximators with different fidelities and computational costs are often available for sample-based likelihood approximation. In this paper, we propose a multi-fidelity Bayesian optimization algorithm for the inference of general nonlinear state-space models (MFBO-SSM), which enables simultaneous sequential selection of parameters and approximators. The accuracy and speed of the algorithm are demonstrated by numerical experiments using synthetic gene expression data from a gene regulatory network model and real data from the VIX stock price index.
- Published
- 2019
21. Control of Gene Regulatory Networks Using Bayesian Inverse Reinforcement Learning
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Ulisses Braga-Neto and Mahdi Imani
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Skin Neoplasms ,Computer science ,Bayesian probability ,Gene regulatory network ,Machine learning ,computer.software_genre ,Models, Biological ,Wnt-5a Protein ,Machine Learning ,Bayes' theorem ,Control theory ,Genetics ,Humans ,Gene Regulatory Networks ,Melanoma ,Sequence ,Models, Genetic ,business.industry ,Gene Expression Profiling ,Applied Mathematics ,Computational Biology ,Bayes Theorem ,Proto-Oncogene Proteins c-mdm2 ,Function (mathematics) ,Kalman filter ,Gene Expression Regulation, Neoplastic ,Boolean network ,Artificial intelligence ,Tumor Suppressor Protein p53 ,business ,computer ,Algorithms ,Software ,Biotechnology - Abstract
Control of gene regulatory networks (GRNs) to shift gene expression from undesirable states to desirable ones has received much attention in recent years. Most of the existing methods assume that the cost of intervention at each state and time point, referred to as the immediate cost function, is fully known. In this paper, we employ the Partially-Observed Boolean Dynamical System (POBDS) signal model for a time sequence of noisy expression measurement from a Boolean GRN and develop a Bayesian Inverse Reinforcement Learning (BIRL) approach to address the realistic case in which the only available knowledge regarding the immediate cost function is provided by the sequence of measurements and interventions recorded in an experimental setting by an expert. The Boolean Kalman Smoother (BKS) algorithm is used for optimally mapping the available gene-expression data into a sequence of Boolean states, and then the BIRL method is efficiently combined with the Q-learning algorithm for quantification of the immediate cost function. The performance of the proposed methodology is investigated by applying a state-feedback controller to two GRN models: a melanoma WNT5A Boolean network and a p53-MDM2 negative feedback loop Boolean network, when the cost of the undesirable states, and thus the identity of the undesirable genes, is learned using the proposed methodology.
- Published
- 2019
22. Prediction of internet-addiction based on perceived social support and father bonding in high school students of Shiraz
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Mahdi Imani and maryam amirinia
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Social support ,business.industry ,Addiction ,media_common.quotation_subject ,The Internet ,business ,Psychology ,Social psychology ,media_common - Published
- 2019
23. Elucidate Genetic Diversity and Population Structure of Bread Wheat (Triticum Aestivum L.) Cultivars Using IRAP and REMAP Markers
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Zoleikha Talebzadeh, Hossein Abbasi Holasou, Fatemeh Rahmani, Mahdi Imani, and Frough Rahmati
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0106 biological sciences ,Genetics ,Genetic diversity ,food and beverages ,Retrotransposon ,04 agricultural and veterinary sciences ,Plant Science ,Biology ,01 natural sciences ,Long terminal repeat ,Gene mapping ,DNA profiling ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Cultivar ,Genetic variability ,Primer (molecular biology) ,Agronomy and Crop Science ,010606 plant biology & botany ,Biotechnology - Abstract
Analysis of genetic diversity and population structure in bread wheat is an essential step in their conservation, utilization, and breeding. Retrotransposons are ubiquitous and abundant a throughout the plant genomes, therefore extensively used as ideal molecular markers for genetic variability, DNA fingerprinting and genetic mapping studies in plant species. In the current research, we used two retrotransposon-based marker systems, inter-retrotransposon amplified polymorphisms (IRAPs), and the retrotransposon-microsatellite amplified polymorphisms (REMAPs) markers to evaluate the genetic diversity and survey activity of long terminal repeat retrotransposon (LTR-retrotransposon) elements in a collection of 49 bread wheat (Triticum aestivum L.) cultivars that mainly bred in Iran. In general, 90 and 126 loci were amplified using 9 IRAP and 20 REMAP primers, respectively. Both techniques produced a satisfactory number of bands for cultivar analysis; however, the technique IRAP, particularly single primer Nikita generated a large number of bands, indicating the wide activity of Nikita family under various environmental conditions of bread wheat. The percentage of polymorphic loci (PPL) in the studied collection for IRAP and REMAP markers was 81.78 and 86.40%, respectively. A model-based Bayesian method, Principal coordinate analysis (PCoA) and cluster analysis using Minimum Evolution (ME) algorithm hinted of the existence of two groups. This grouping was in agreement with the growing season and conformed by the high within-group bootstrap value. These results demonstrated that these markers developed using transpositionally active retrotransposons (RTNs) are efficient and reliable markers in determining level of genetic diversity and population structure in bread wheat in breeding programs.
- Published
- 2019
24. Point-Based Methodology to Monitor and Control Gene Regulatory Networks via Noisy Measurements
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Ulisses Braga-Neto and Mahdi Imani
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0209 industrial biotechnology ,Noise measurement ,Computer science ,Computation ,0206 medical engineering ,Gene regulatory network ,02 engineering and technology ,Kalman filter ,computer.software_genre ,System dynamics ,020901 industrial engineering & automation ,Control and Systems Engineering ,Robustness (computer science) ,Backup ,Process control ,Data mining ,Electrical and Electronic Engineering ,computer ,020602 bioinformatics - Abstract
This paper proposes a methodology to monitor and control gene regulatory networks (GRNs) via noisy measurements in an infinite observation space. Toward this end, we employ the partially observed Boolean dynamical system (POBDS) signal model. The proposed methodology consists of offline and online steps. In the offline step, a family of point-based methods is applied to the POBDS model to gather the necessary control policy prior to the online (execution) step. This is accomplished by developing efficient backup and belief expansion processes to make the computation scale with the log of the number of states, as opposed to the complexity of existing point-based methods, which grows with the number of states. In the online step, simultaneous monitoring and control is achieved by a one-step look-ahead search procedure using the optimal state estimation algorithm for the POBDS model, known as the Boolean Kalman filter (BKF), as well as the information gathered in the offline step. The online one-step look-ahead process confers robustness to changes in system dynamics, possibility of starting the execution process before the completion of the offline step. The use of the BKF for simultaneous monitoring and control during the online stage can be key in assessing possible side effects of intervention. The performance of the proposed methodology is investigated through a comprehensive set of numerical experiments using synthetic gene expression data generated from a melanoma GRN.
- Published
- 2019
25. Bayesian Surrogate Learning for Uncertainty Analysis of Coupled Multidisciplinary Systems
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Seyede Fatemeh Ghoreishi and Mahdi Imani
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0209 industrial biotechnology ,Computer science ,business.industry ,Bayesian probability ,02 engineering and technology ,Machine learning ,computer.software_genre ,Computer Graphics and Computer-Aided Design ,Industrial and Manufacturing Engineering ,Computer Science Applications ,020901 industrial engineering & automation ,Multidisciplinary approach ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,computer ,Software ,Uncertainty analysis - Abstract
Engineering systems are often composed of many subsystems that interact with each other. These subsystems, referred to as disciplines, contain many types of uncertainty and in many cases are feedback-coupled with each other. In designing these complex systems, one needs to assess the stationary behavior of these systems for the sake of stability and reliability. This requires the system level uncertainty analysis of the multidisciplinary systems, which is often computationally intractable. To overcome this issue, techniques have been developed for capturing the stationary behavior of the coupled multidisciplinary systems through available data of individual disciplines. The accuracy and convergence of the existing techniques depend on a large amount of data from all disciplines, which are not available in many practical problems. Toward this, we have developed an adaptive methodology that adds the minimum possible number of samples from individual disciplines to achieve an accurate and reliable uncertainty propagation in coupled multidisciplinary systems. The proposed method models each discipline function via Gaussian process (GP) regression to derive a closed-form policy. This policy sequentially selects a new sample point that results in the highest uncertainty reduction over the distribution of the coupling design variables. The effectiveness of the proposed method is demonstrated in the uncertainty analysis of an aerostructural system and a coupled numerical example.
- Published
- 2021
26. Scalable Inverse Reinforcement Learning Through Multifidelity Bayesian Optimization
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Seyede Fatemeh Ghoreishi and Mahdi Imani
- Subjects
Computer Networks and Communications ,Computer science ,Process (engineering) ,media_common.quotation_subject ,Reliability (computer networking) ,Control (management) ,Context (language use) ,02 engineering and technology ,Machine learning ,computer.software_genre ,Artificial Intelligence ,0202 electrical engineering, electronic engineering, information engineering ,Learning ,Function (engineering) ,media_common ,business.industry ,Bayesian optimization ,Reproducibility of Results ,Bayes Theorem ,Computer Science Applications ,Range (mathematics) ,Scalability ,020201 artificial intelligence & image processing ,Artificial intelligence ,Neural Networks, Computer ,business ,computer ,Reinforcement, Psychology ,Software - Abstract
Data in many practical problems are acquired according to decisions or actions made by users or experts to achieve specific goals. For instance, policies in the mind of biologists during the intervention process in genomics and metagenomics are often reflected in available data in these domains, or data in cyber-physical systems are often acquired according to actions/decisions made by experts/engineers for purposes, such as control or stabilization. Quantification of experts' policies through available data, which is also known as reward function learning, has been discussed extensively in the literature in the context of inverse reinforcement learning (IRL). However, most of the available techniques come short to deal with practical problems due to the following main reasons: 1) lack of scalability: arising from incapability or poor performance of existing techniques in dealing with large systems and 2) lack of reliability: coming from the incapability of the existing techniques to properly learn the optimal reward function during the learning process. Toward this, in this brief, we propose a multifidelity Bayesian optimization (MFBO) framework that significantly scales the learning process of a wide range of existing IRL techniques. The proposed framework enables the incorporation of multiple approximators and efficiently takes their uncertainty and computational costs into account to balance exploration and exploitation during the learning process. The proposed framework's high performance is demonstrated through genomics, metagenomics, and sets of random simulated problems.
- Published
- 2021
27. Bayesian Optimization for Efficient Design of Uncertain Coupled Multidisciplinary Systems
- Author
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Seyede Fatemeh Ghoreishi and Mahdi Imani
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Computer science ,Bayesian optimization ,Complex system ,020206 networking & telecommunications ,02 engineering and technology ,Aerodynamics ,Critical infrastructure ,Set (abstract data type) ,symbols.namesake ,020901 industrial engineering & automation ,Multidisciplinary approach ,Scalability ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Gibbs sampling - Abstract
Stabilization of complex cyber-physical systems is extremely important in keeping the critical infrastructure and the environment safe. This is, in particular, critical in coupled multidisciplinary systems with several subsystems interacting with each other in an uncertain environment. The design of stabilized complex systems depends on a proper set of inputs to these subsystems, in such a way that the best stationary behavior of these systems is achieved. Despite several attempts for stabilizing the coupled multidisciplinary systems, the existing techniques still have their critical limitations and issues due to the unrealistic deterministic assumption in some cases as well as inability in handling large-scale systems. In this paper, we introduce a Bayesian framework using the combination of Bayesian optimization technique and Gibbs sampling method, which enables scalable, efficient and fast learning of the best input to achieve the best design of multidisciplinary systems. The accuracy and speed of the proposed framework will be demonstrated in numerical experiments using an aerodynamics- structures system and a mathematical example.
- Published
- 2020
28. Bayesian Optimization Objective-Based Experimental Design
- Author
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Seyede Fatemeh Ghoreishi and Mahdi Imani
- Subjects
Hyperparameter ,0209 industrial biotechnology ,Class (computer programming) ,Mathematical optimization ,Process (engineering) ,Computer science ,Reliability (computer networking) ,Bayesian optimization ,0211 other engineering and technologies ,02 engineering and technology ,Range (mathematics) ,020901 industrial engineering & automation ,Scalability ,Entropy (information theory) ,021106 design practice & management - Abstract
Design has become a salient part of most of the scientific and engineering tasks, embracing a wide range of domains including real experimental settings (e.g., material discovery or drug design), simulation-based design, and hyperparameter tuning. Model-based experimental design refers to a broad class of techniques, applicable to domains that a partial knowledge about the underlying process exists. Unlike entropy- based techniques which aim to reduce the whole uncertainty in the process, the mean objective cost of uncertainty (MOCU) is a rigorous statistically-oriented experimental design framework which takes the main objective into account during the decision making. However, the lack of scalability of this framework has restricted its application to domains with very small design spaces. This paper proposes a framework using the combination of Bayesian optimization and MOCU policy, which enables experimental design to much larger design spaces and systems. The reliability, scalability and efficiency of the proposed framework are investigated through experimental design for optimal structural intervention in gene regulatory networks.
- Published
- 2020
29. Finite-horizon LQR controller for partially-observed Boolean dynamical systems
- Author
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Mahdi Imani and Ulisses Braga-Neto
- Subjects
0209 industrial biotechnology ,Dynamical systems theory ,Computer science ,020206 networking & telecommunications ,02 engineering and technology ,Linear-quadratic regulator ,Space (mathematics) ,Regularization (mathematics) ,Nonlinear system ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Trajectory ,Observability ,Electrical and Electronic Engineering - Abstract
This paper proposes an approach for finite-horizon control of partially-observed Boolean dynamical systems (POBDS) with uncertain continuous control input and infinite observation space. To cope with the partial observability of states, the proposed method first maps the POBDS to an unnormalized belief space. The nonlinear dynamics in this continuous belief space are linearized over a nominal trajectory. Then, the optimal feedback controller is derived, based on the well-known linear quadratic regulator (LQR), to push the system to follow the nominal trajectory. This nominal trajectory is computed in a planning stage before starting execution, and updated efficiently during execution, whenever the system is found to deviate from the nominal trajectory. We prove that, under mild regularization conditions, the proposed controller approaches the cost of the nominal trajectory as the linearization error approaches zero. The performance of the proposed controller is demonstrated by numerical experiments with a Melanoma gene regulatory network observed through noisy gene expression measurements.
- Published
- 2018
30. Offline Fault Detection in Gene Regulatory Networks using Next-Generation Sequencing Data
- Author
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Seyede Fatemeh Ghoreishi and Mahdi Imani
- Subjects
0209 industrial biotechnology ,Computer science ,Kalman smoother ,0206 medical engineering ,Gene regulatory network ,02 engineering and technology ,Kalman filter ,computer.software_genre ,Fault detection and isolation ,Data set ,020901 industrial engineering & automation ,Boolean network ,Categorization ,Negative feedback ,Data mining ,computer ,020602 bioinformatics ,Change detection ,Statistical hypothesis testing - Abstract
In a previous contribution, a method was proposed for on-line fault detection in Boolean gene regulatory networks based on the Boolean Kalman Filter and hypothesis testing on next-generation sequencing (NGS) data. In this paper, we present a related methodology, which differs in two main points: (1) it uses the Boolean Kalman Smoother on the entire data set stored off-line; (2) it employs a maximum-likelihood approach for simultaneous change detection and categorization. The efficacy of the proposed methodology is assessed using a p53-MDM2 negative feedback loop Boolean network with stuck-at faults that model molecular events commonly found in cancer.
- Published
- 2019
31. Maximum-Likelihood Adaptive Filter for Partially Observed Boolean Dynamical Systems
- Author
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Mahdi Imani and Ulisses Braga-Neto
- Subjects
0301 basic medicine ,0209 industrial biotechnology ,Dynamical systems theory ,Noise measurement ,Estimation theory ,business.industry ,Quantitative Biology::Molecular Networks ,Estimator ,02 engineering and technology ,Kalman filter ,Machine learning ,computer.software_genre ,Adaptive filter ,03 medical and health sciences ,Extended Kalman filter ,030104 developmental biology ,020901 industrial engineering & automation ,Signal Processing ,Artificial intelligence ,Electrical and Electronic Engineering ,Time series ,business ,Algorithm ,computer ,Mathematics - Abstract
We present a framework for the simultaneous estimation of state and parameters of partially observed Boolean dynamical systems (POBDS). Simultaneous state and parameter estimation is achieved through the combined use of the Boolean Kalman filter and Boolean Kalman smoother, which provide the minimum mean-square error state estimators for the POBDS model, and maximum-likelihood (ML) parameter estimation; in the presence of continuous parameters, ML estimation is performed using the expectation–maximization algorithm. The performance of the proposed ML adaptive filter is demonstrated by numerical experiments with a POBDS model of gene regulatory networks observed through noisy next-generation sequencing (RNA-seq) time series data using the well-known p53-MDM2 negative-feedback loop gene regulatory model.
- Published
- 2017
32. Is Physical Frailty a Neuromuscular Condition?
- Author
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Ebrahim Bani Hassan, Gustavo Duque, and Mahdi Imani
- Subjects
medicine.medical_specialty ,Frailty ,medicine.diagnostic_test ,business.industry ,Frail Elderly ,Health Policy ,MEDLINE ,Geriatric assessment ,Physical examination ,General Medicine ,Physical therapy ,Humans ,Medicine ,Frail elderly ,Gray Matter ,Geriatrics and Gerontology ,business ,Geriatric Assessment ,Physical Examination ,General Nursing ,Aged - Published
- 2019
33. Boolean Kalman filter and smoother under model uncertainty
- Author
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Edward R. Dougherty, Ulisses Braga-Neto, and Mahdi Imani
- Subjects
0209 industrial biotechnology ,Dynamical systems theory ,Estimation theory ,Computer science ,020208 electrical & electronic engineering ,Estimator ,Markov chain Monte Carlo ,02 engineering and technology ,State (functional analysis) ,Kalman filter ,Parameter space ,Nonlinear system ,symbols.namesake ,020901 industrial engineering & automation ,Control and Systems Engineering ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Electrical and Electronic Engineering ,Algorithm - Abstract
Partially-observed Boolean dynamical systems (POBDS) are a general class of nonlinear state-space models that provide a rich framework for modeling many complex dynamical systems. The model consists of a hidden Boolean state process, observed through an arbitrary noisy mapping to a measurement space. The optimal minimum mean-square error (MMSE) POBDS state estimators are the Boolean Kalman Filter and Smoother. However, in many practical problems, the system parameters are not fully known and must be estimated. In this paper, for POBDS under model uncertainty, we derive an optimal Bayesian estimator for state and parameter estimation. The exact algorithms are derived for the case of discrete and finite parameter space, and for general parameter spaces, an approximate Markov-Chain Monte-Carlo (MCMC) implementation is introduced. We demonstrate the performance of the proposed methodology by means of numerical experiments with POBDS models of gene regulatory networks observed through noisy measurements.
- Published
- 2020
34. Morphological Changes Induced By Extremely Low-Frequency Electric Fields
- Author
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Reza Faraji-Dana, Mahdi Imani, Sepide Kazemi, Behnam Sadeghi, Leila Farahmand, and Mehrdad Saviz
- Subjects
Erythrocytes ,Physiology ,Biophysics ,02 engineering and technology ,Cell morphology ,Umbilical cord ,030218 nuclear medicine & medical imaging ,Cell Line ,Birds ,03 medical and health sciences ,0302 clinical medicine ,Electromagnetic Fields ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Animals ,Humans ,Radiology, Nuclear Medicine and imaging ,Bioelectromagnetics ,Chemistry ,Mesenchymal stem cell ,Temperature ,Nucleated Red Blood Cell ,020206 networking & telecommunications ,Cell Differentiation ,Mesenchymal Stem Cells ,General Medicine ,Hydrogen-Ion Concentration ,Fetal Blood ,Electric Stimulation ,Staining ,medicine.anatomical_structure ,Cytoplasm ,Hemoglobin - Abstract
In this paper, morphological effects of electric fields on avian erythrocytes (nucleated red blood cells) have been studied in detail. Morphological changes include rounding and cytoplasm transparency. It has been shown that the effect is non-thermal. Careful imaging and image analyses have been carried out to show that the degree of this effect is frequency-dependent, and has a higher conversion rate at higher temperatures. Furthermore, to better understand the mechanisms behind the morphological changes, we investigated the dedifferentiation hypothesis and performed a series of tests on avian erythrocytes including fluorescence spectroscopy for hemoglobin, and tests on human umbilical cord blood, mesenchymal stem cells, and bone marrow mesenchymal stem cells including flow-cytometry analysis for expression of certain markers and calcium staining. Bioelectromagnetics. 2019;40:375-390. © 2019 Bioelectromagnetics Society.
- Published
- 2018
35. Relationship Between Self-Compassion, Emotional Quotient and Maternal Styles with Well-Being in Shiraz School Students
- Author
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Mahdi Imani and Alireza Zareian
- Subjects
education ,Population ,compassion ,Personal life ,Developmental psychology ,symbols.namesake ,self ,being ,Subjective well-being ,well ,education.field_of_study ,maternal styles ,students ,lcsh:Public aspects of medicine ,Emotional intelligence ,satisfaction ,lcsh:RA1-1270 ,Mental health ,Pearson product-moment correlation coefficient ,Well-being ,symbols ,Psychology ,mental health ,Self-compassion ,emotional quotient - Abstract
Background: According to research, ones well-being is an important factor for mental health and satisfaction in one’s personal life and people with more well-being are more satisfied with their lives. Objectives: The purpose of this study is to find a relationship between self-compassion, emotional quotient, and maternal styles with the well-being in Shiraz school students. Methods: Elementary school students and high school students in the academic year of 2018 were the research population. A total of 510 students who were chosen by multistage sampling method consisted this study sample so that based on the number of schools in Shiraz, 24 primary and high schools were chosen. Two classes from each school were selected and 9 to 11 students from each class participate in study. The tools used were maternal style questionnaire, self-compassion scale (SCS), emotional quotient scale (TMMS), and subjective well being inventory (SWB). Pearson correlation coefficient and multiple regression were applied for analyzing data. Results: According to the analysis, authoritative maternal style, self-compassion, and emotional quotient were important predictors of ones well-being and they can predict 81% of well-being in this study (P = 0.003). In addition, significant correlations were found between authoritative maternal style and self-compassion (correlation coefficient = 0.88, P = 0.007), authoritative maternal style and emotional quotient (correlation coefficient = 0.86, P = 0.008), and authoritative maternal style and subjective well-being (correlation coefficient = 0.94, P = 0.005). Conclusions: According to this study, maternal style, emotional quotient, and self-compassion play an important role in the society and individuals mental health and well-being, therefore, these factors should be attended, especially the authoritative maternal style, which has the most correlation with well-being.
- Published
- 2018
36. Optimal Control of Gene Regulatory Networks with Unknown Cost Function
- Author
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Ulisses Braga-Neto and Mahdi Imani
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,020901 industrial engineering & automation ,Computer science ,Control (management) ,0202 electrical engineering, electronic engineering, information engineering ,Gene regulatory network ,020206 networking & telecommunications ,02 engineering and technology ,Function (mathematics) ,State (computer science) ,Dynamical system ,Optimal control - Abstract
Most of the existing methodologies for control of Gene Regulatory Networks (GRNs) assume that the immediate cost function at each state and time point is fully known. In this paper, we introduce an optimal control strategy for control of GRNs with unknown or partially-known immediate cost function. Toward this, we adopt a partially-observed Boolean dynamical system (POBDS) model for the GRN and propose an Inverse Reinforcement Learning (IRL) methodology for quantifying the imperfect behavior of experts, obtained via prior biological knowledge or experimental data. The constructed cost function then is used in finding the optimal infinite-horizon control strategy for the POBDS. The application of the proposed method using a single sequence of experimental data is investigated through numerical experiments using a melanoma gene regulatory network.
- Published
- 2018
37. Gene regulatory network state estimation from arbitrary correlated measurements
- Author
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Ulisses Braga-Neto and Mahdi Imani
- Subjects
0301 basic medicine ,0209 industrial biotechnology ,Computer science ,Gene regulatory network ,lcsh:TK7800-8360 ,02 engineering and technology ,Dynamical system ,lcsh:Telecommunication ,03 medical and health sciences ,Partially-observed Boolean dynamical system ,020901 industrial engineering & automation ,lcsh:TK5101-6720 ,Gene expression ,Minimum mean square error ,Quantitative Biology::Molecular Networks ,lcsh:Electronics ,Estimator ,Kalman filter ,Correlated measurement noise ,Tree (data structure) ,Complex dynamics ,Boolean Kalman Filter and Smoother ,030104 developmental biology ,Boolean network ,Anomaly detection ,Algorithm ,State estimation ,Smoothing - Abstract
Background Advancements in gene expression technology allow acquiring cheap and abundant data for analyzing cell behavior. However, these technologies produce noisy, and often correlated, measurements on the transcriptional states of genes. The Boolean network model has been shown to be effective in capturing the complex dynamics of gene regulatory networks (GRNs). It is important in many applications, such as anomaly detection and optimal intervention, to be able to track the evolution of the Boolean states of a gene regulatory network using noisy time-series transcriptional measurements, which may be correlated in time. Results We propose efficient estimators for the Boolean states of GRNs using correlated time-series transcriptional measurements, where the nature of the correlation and of the measurements themselves are entirely arbitrary. More specifically, we propose new algorithms based on a hypothesis tree to compute optimal minimum mean square error (MMSE) filtering and smoothing state estimators for a Partially-Observed Boolean Dynamical System (POBDS) with correlated measurements. The algorithms are exact but may be computationally expensive for large state spaces or long time horizons, in which case a process for pruning the hypothesis tree is employed to obtain an approximation of the optimal MMSE estimators, while keeping computation tractable. Performance is assessed through a comprehensive set of numerical experiments based on the p53-MDM2 negative-feedback loop Boolean regulatory network, where the standard Boolean Kalman Filter (BKF) and Boolean Kalman Smoother (BKS) for uncorrelated measurements are compared to the corresponding new estimators for correlated measurements, called BKF-CORR and BKS-CORR, respectively.
- Published
- 2018
38. Optimal finite-horizon sensor selection for Boolean Kalman Filter
- Author
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Mahdi Imani and Ulisses Braga-Neto
- Subjects
0209 industrial biotechnology ,Noise measurement ,Dynamical systems theory ,Noise (signal processing) ,Computer science ,Gene regulatory network ,Estimator ,020206 networking & telecommunications ,02 engineering and technology ,Kalman filter ,Loop (topology) ,Bernoulli's principle ,020901 industrial engineering & automation ,0202 electrical engineering, electronic engineering, information engineering ,Algorithm - Abstract
Partially-observed Boolean dynamical systems (POBDS) are large and complex dynamical systems capable of being monitored through various sensors. However, time, storage, and economical constraints may impede the use of all sensors for estimation purposes. Thus, developing a procedure for selecting a subset of sensors is essential. The optimal minimum mean-square error (MMSE) POBDS state estimator is the Boolean Kalman Filter (BKF) and Smoother (BKS). Naturally, the performance of these estimators strongly depends on the choice of sensors. Given a finite subsets of sensors, for a POBDS with a finite observation space, we introduce the optimal procedure to select the best subset which leads to the smallest expected mean-square error (MSE) of the BKF over a finite horizon. The performance of the proposed sensor selection methodology is demonstrated by numerical experiments with a p53-MDM2 negative-feedback loop gene regulatory network observed through Bernoulli noise.
- Published
- 2017
39. Nonstationary linear discriminant analysis
- Author
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Ulisses Braga-Neto, Shuilian Xie, Edward R. Dougherty, and Mahdi Imani
- Subjects
Independent and identically distributed random variables ,education.field_of_study ,021103 operations research ,State-space representation ,Population ,0211 other engineering and technologies ,020206 networking & telecommunications ,02 engineering and technology ,Kalman filter ,Linear discriminant analysis ,Set (abstract data type) ,Classification rule ,Statistical learning theory ,0202 electrical engineering, electronic engineering, information engineering ,education ,Algorithm - Abstract
Changes in population distributions over time are common in many applications. However, the vast majority of statistical learning theory takes place under the assumption that all points in the training data are identically distributed (and independent), that is, non-stationarity of the data is disregarded. In this paper, a version of the classic Linear Discriminant Analysis (LDA) classification rule is proposed for nonstationary data, using a linear-Gaussian state space model. This Nonstationary LDA (NSLDA) classification rule is based on the Kalman Smoother algorithm to estimate the evolving population parameters. In case the dynamics of the system are not fully known, a combination of the Expectation-Maximization (EM) algorithm and the Kalman Smoother is employed to simultaneously estimate population and statespace equation parameters. Performance is assessed in a set of numerical experiments using simulated data, where the average error rates obtained by NSLDA are compared to the error produced by a naive application of LDA to the pooled nonstationary data. Results demonstrate the promise of the proposed NSLDA classification rule.
- Published
- 2017
40. The Role of Job Burnout and Depression in Self-Destructive Behavior of Islamic Republic of Iran's Army Personnel
- Author
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Mohammad Reza Kazemia, Mahdi Imani, Khadijeh Shiralinia, and Arsia Taghva
- Subjects
medicine.medical_specialty ,Active duty ,Islamic republic ,Job burnout ,Burnout ,Mental health ,Psychiatry and Mental health ,Clinical Psychology ,Military personnel ,Self-destructive behavior ,medicine ,medicine.symptom ,Psychology ,Psychiatry ,Depression (differential diagnoses) ,Clinical psychology - Abstract
Aim of the studyThe aim of present study was to investigate the role of job burnout and depression in self-destructive behavior in army personnel of Islamic Republic of Iran. To this end up, a conceptual structural model was examined.Subject or material and methodsParticipants were 215 active duty personnel of the Islamic Republic of Iran Army (age mean=31.07 years; SD=4.71) which they completed Suicide Behavior Questionnaire-Revised (SBQ-R), Self-Harm Inventory (SHI), Beck Depression Inventory-Second Edition (BDI-II-Persian), Maslach Burnout Inventory (MBI).ResultsThe measurement model revealed that all indicators, except self-efficacy, had a significant factor weight on their latent variable, therefore the model revised by omitting it and the modified measurement model showed good fitness according to GFI, AGFI, CFI, IFI, and RMSEA. Structural model results showed burnout has a direct effect on self-destructive behavior (β=0.24), depression has a direct effect on self-destructive behavior (β=0.56); burnout influenced depression indirectly (β=0.56); burnout has indirect (β=0.35) and total effects (β=0.59) on self-destructive behavior. Finally the fitness indices of the structural model showed relatively good fitness.DiscussionBurnout and depression directly increase the tendency to self-destruction among militants. Moreover, findings revealed that job burnout influence self-destruction by intensifying depression.Conclusionssome intervention must be considered to prevent self-destruction among militants
- Published
- 2015
41. Multiple Model Adaptive controller for Partially-Observed Boolean Dynamical Systems
- Author
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Ulisses Braga-Neto and Mahdi Imani
- Subjects
0209 industrial biotechnology ,Dynamical systems theory ,0206 medical engineering ,02 engineering and technology ,Kalman filter ,Dynamical system ,020901 industrial engineering & automation ,Boolean network ,Control theory ,Adaptive system ,Process control ,Finite set ,020602 bioinformatics ,Mathematics - Abstract
This paper is concerned with developing an adaptive controller for Partially-Observed Boolean Dynamical Systems (POBDS). Assuming that partial knowledge about the system can be modeled by a finite number of candidate models, then simultaneous identification and control of a POBDS is achieved using the combination of a state-feedback controller and a Multiple-Model Adaptive Estimation (MMAE) technique. The proposed method contains two main steps: first, in the offline step, the stationary control policy for the underlying Boolean dynamical system is computed for each candidate model. Then, in the online step, an optimal Bayesian estimator is modeled using a bank of Boolean Kalman Filters (BKFs), each tuned to a candidate model. The result of the offline step along with the estimated state by the bank of BKFs specify the control input that should be applied at each time point. The performance of the proposed adaptive controller is investigated using a Boolean network model constructed from melanoma gene expression data observed through RNA-seq measurements.
- Published
- 2017
42. Boolean Kalman Filter with correlated observation noise
- Author
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Levi D. McClenny, Ulisses Braga-Neto, and Mahdi Imani
- Subjects
0301 basic medicine ,Noise measurement ,Optimal estimation ,Dynamical systems theory ,State (functional analysis) ,Kalman filter ,Filter (higher-order function) ,03 medical and health sciences ,Noise ,030104 developmental biology ,Control theory ,Hidden Markov model ,Algorithm ,Mathematics - Abstract
This paper is concerned with optimal estimation of the state of a Boolean dynamical systems observed through correlated noisy Boolean measurements. The optimal Minimum Mean-Square Error (MMSE) state estimator for general Partially-Observed Boolean Dynamical Systems (POBDS) can be computed via the Boolean Kalman Filter (BKF). However, thus far in the literature only the case of white observation noise has been considered. In this paper, we develop the optimal MMSE filter for a class of POBDS with correlated Boolean measurements. The performance of the proposed method is subsequently investigated using the p53-MDM2 negative feedback loop genetic network model.
- Published
- 2017
43. Control of Gene Regulatory Networks with Noisy Measurements and Uncertain Inputs
- Author
-
Mahdi Imani and Ulisses Braga-Neto
- Subjects
FOS: Computer and information sciences ,0209 industrial biotechnology ,Control and Optimization ,Computer Networks and Communications ,Computer science ,Molecular Networks (q-bio.MN) ,Gene regulatory network ,Machine Learning (stat.ML) ,02 engineering and technology ,Machine Learning (cs.LG) ,symbols.namesake ,020901 industrial engineering & automation ,Control theory ,Statistics - Machine Learning ,0202 electrical engineering, electronic engineering, information engineering ,Reinforcement learning ,Quantitative Biology - Molecular Networks ,Observability ,Gaussian process ,Stochastic control ,Quantitative Biology::Molecular Networks ,Function (mathematics) ,Computer Science - Learning ,Control and Systems Engineering ,Control system ,FOS: Biological sciences ,Signal Processing ,symbols ,020201 artificial intelligence & image processing ,Markov decision process ,Algorithm - Abstract
This paper is concerned with the problem of stochastic control of gene regulatory networks (GRNs) observed indirectly through noisy measurements and with uncertainty in the intervention inputs. The partial observability of the gene states and uncertainty in the intervention process are accounted for by modeling GRNs using the partially observed Boolean dynamical system (POBDS) signal model with noisy gene expression measurements. Obtaining the optimal infinite-horizon control strategy for this problem is not attainable in general, and we apply reinforcement learning and Gaussian process techniques to find a near-optimal solution. The POBDS is first transformed to a directly observed Markov decision process in a continuous belief space, and the Gaussian process is used for modeling the cost function over the belief and intervention spaces. Reinforcement learning then is used to learn the cost function from the available gene expression data. In addition, we employ sparsification, which enables the control of large partially observed GRNs. The performance of the resulting algorithm is studied through a comprehensive set of numerical experiments using synthetic gene expression data generated from a melanoma gene regulatory network.
- Published
- 2017
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44. Point-based value iteration for partially-observed Boolean dynamical systems with finite observation space
- Author
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Ulisses Braga-Neto and Mahdi Imani
- Subjects
Discrete mathematics ,Dynamical systems theory ,Boolean model ,Boolean circuit ,0206 medical engineering ,020206 networking & telecommunications ,02 engineering and technology ,Boolean network ,Maximum satisfiability problem ,0202 electrical engineering, electronic engineering, information engineering ,State space ,Applied mathematics ,Circuit minimization for Boolean functions ,020602 bioinformatics ,Standard Boolean model ,Mathematics - Abstract
This paper is concerned with obtaining the infinite-horizon control policy for partially-observed Boolean dynamical systems (POBDS) when measurements take place in a finite observation space, with application to Boolean gene regulatory networks. The goal of control is to reduce the steady-state mass of undesirable states, which might be associated with disease. The idea behind the proposed method is to transfer the partially-observed Boolean states into a continuous observed state space known as belief space, and then employ the well-known value iteration method based on Point-Based Value Iteration (PBVI). The performance of the method is investigated using a Boolean network model constructed from melanoma gene-expression data observed through Bernoulli noise.
- Published
- 2016
45. Adaptive Particle Filtering for Fault Detection in Partially-Observed Boolean Dynamical Systems
- Author
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Mahdi Imani, Arghavan Bahadorinejad, and Ulisses Braga-Neto
- Subjects
Stochastic Processes ,Models, Genetic ,Dynamical systems theory ,Computational complexity theory ,Stochastic process ,Computer science ,Applied Mathematics ,0206 medical engineering ,Computational Biology ,02 engineering and technology ,Kalman filter ,Fault detection and isolation ,Nonlinear system ,Saccharomycetales ,Expectation–maximization algorithm ,Genetics ,Gene Regulatory Networks ,RNA-Seq ,Particle filter ,Algorithm ,Algorithms ,020602 bioinformatics ,Biotechnology - Abstract
We propose a novel methodology for fault detection and diagnosis in partially-observed Boolean dynamical systems (POBDS). These are stochastic, highly nonlinear, and derivativeless systems, rendering difficult the application of classical fault detection and diagnosis methods. The methodology comprises two main approaches. The first addresses the case when the normal mode of operation is known but not the fault modes. It applies an innovations filter (IF) to detect deviations from the nominal normal mode of operation. The second approach is applicable when the set of possible fault models is finite and known, in which case we employ a multiple model adaptive estimation (MMAE) approach based on a likelihood-ratio (LR) statistic. Unknown system parameters are estimated by an adaptive expectation-maximization (EM) algorithm. Particle filtering techniques are used to reduce the computational complexity in the case of systems with large state-spaces. The efficacy of the proposed methodology is demonstrated by numerical experiments with a large gene regulatory network (GRN) with stuck-at faults observed through a single noisy time series of RNA-seq gene expression measurements.
- Published
- 2019
46. Evaluation of Testosterone and Alkaline Phosphatase Activity Changes in Epidydimis of Toxoplasma gondii Infected Rats
- Author
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Hossein H.Farhang, Sasan Najjari Asl, Amir Ezzatzadeh, Fatemeh Afshari, Amir Mahdi Imani, Nava Ainechi, and Khazar Ghasempour
- Subjects
medicine.medical_specialty ,biology ,business.industry ,Veterinary pathology ,Obstetrics and Gynecology ,Toxoplasma gondii ,Physiology ,Testosterone (patch) ,medicine.disease ,Malondialdehyde ,biology.organism_classification ,Epididymis ,Toxoplasmosis ,chemistry.chemical_compound ,medicine.anatomical_structure ,Reproductive Medicine ,chemistry ,parasitic diseases ,Immunology ,medicine ,Alkaline phosphatase ,Histopathology ,business - Abstract
Objective: Toxoplasma gondii is a widespread protozoan parasite that infects a broad range of warm blooded animals and humans. The present study was investigated to evaluate testosterone, alkaline phosphatase activity and malondialdehyde in male rats experimentally infected by Toxoplasma gondii, RH strain. Material & Methods: Male Wistar rats (n=20) were allocated into two groups, group one (n=10) that received 0.6 cc tachyzoites of T. gondii intraperitoneally (I.P.), and control group (n=10) that received nothing. Animals were kept in standard conditions. 30 days after inducing Toxoplasma infection, 5cc blood was collected for assessment of serum testosterone, alkaline phosphatase and malondialdehyde levels. Epididymis tissues of Rats in whole groups were removed and prepared for analysis. Results: Alkaline phosphatase, and Testosterone were significantly increased in group that was infected by T.gondii in comparison to control group (P 0.05). Epididymis weights in toxoplasmosis group was significantly decreased in comparison to control group (P
- Published
- 2013
47. State-feedback control of Partially-Observed Boolean Dynamical Systems using RNA-seq time series data
- Author
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Mahdi Imani and Ulisses Braga-Neto
- Subjects
0209 industrial biotechnology ,Observer (quantum physics) ,Dynamical systems theory ,Stochastic process ,Computer science ,020206 networking & telecommunications ,02 engineering and technology ,Kalman filter ,Observer (special relativity) ,Separation principle ,Quantitative Biology::Genomics ,020901 industrial engineering & automation ,Boolean network ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Process control ,Time series - Abstract
External control of a genetic regulatory network is used for the purpose of avoiding undesirable states, such as those associated with disease. This paper proposes a strategy for state-feedback infinite-horizon control of Partially-Observed Boolean Dynamical Systems (POBDS) using a single time series of Next-Generation Sequencing (NGS) RNA-seq data. A separation principle is assumed, whereby first the optimal stationary policy is obtained offline by solving Bellman's equation, and then an optimal MMSE observer, the Boolean Kalman Filter, is employed for online implementation of the policy using the RNA-seq observations of the evolving system. Performance is investigated using a Boolean network model of the mutated mammalian cell cycle and simulated RNA-seq observations.
- Published
- 2016
48. Optimal state estimation for boolean dynamical systems using a boolean Kalman smoother
- Author
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Ulisses Braga-Neto and Mahdi Imani
- Subjects
Mathematical optimization ,Boolean network ,Series (mathematics) ,Dynamical systems theory ,Quantitative Biology::Molecular Networks ,Gene regulatory network ,Kalman filter ,Dynamical system ,Hidden Markov model ,Algorithm ,Standard Boolean model ,Mathematics - Abstract
This paper is concerned with state estimation at a fixed time point in a given time series of observations of a Boolean dynamical system. Towards this end, we introduce the Boolean Kalman Smoother, which provides an efficient algorithm to compute the optimal MMSE state estimator for this problem. Performance is investigated using a Boolean network model of the p53-MDM2 negative feedback loop gene regulatory network observed through time series of Next-Generation Sequencing (NGS) data.
- Published
- 2015
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