Optimal resurfacing decisions for road maintenance: A POMDP perspective

Zouch, Mariem; Yeung, Thomas; Castanier, Bruno

doi:10.1109/rams.2011.5754479

Cited by 4 publications

(4 citation statements)

References 18 publications

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“…Markov decision processes (MDPs) have commonly been leveraged for condition-based maintenance due to their ability to characterize multiple maintenance actions and multiple degradation states (Papakonstantinou & Shinozuka 2014b,c). In particular, POMDPs have been utilized in the optimal maintenance of numerous systems (eg., (Byon et al 2010, Ge et al 2007, Ghandali et al 2020, Papakonstantinou & Shinozuka 2014a, Zhang & Revie 2017, Zouch et al 2011). More recently, Morato et al (2022) proposed integrating Bayesian networks with POMDPs to provide a joint framework for inspection and maintenance planning.…”

Section: Literature Reviewmentioning

confidence: 99%

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

2022

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Background PAH is a devastating and incurable disease characterized by abnormal pulmonary vascular phenotypes and progressive right ventricular failure, but the underlying mechanisms are incompletely understood. There is an urgent need of new therapeutic approaches, and a better understanding of disease pathogenesis is essential in identifying novel pathways that can be therapeutically targeted. Stress granules (SGs) are small intracellular structures that form in response to stress and contain mRNA molecules and mRNA‐binding proteins. These granules allow cells to temporarily halt translation by “parking” or sequestering certain mRNAs in a protected zone (the stress granule) and this allows the cells to survive in conditions of stress. The role of SGs in abnormal vascular and cardiac homeostasis in PAH is not known. Hypotheses We hypothesized that increased SG formation may contribute to both abnormal vascular cellular phenotypes and cardiac failure in human and experimental PAH. Further, we examined whether treatment with the carbonic anhydrase Acetazolamide (ACTZ) which is known to ameliorate experimental PAH, would alter SG tissue abundance in the lungs and heart. Methods We used the adult rat (Sprague Dawley) sugen/hypoxia (Su/Hx) model of severe pulmonary hypertension and studied tissue sections from lungs, heart and skeletal muscle as well as isolated primary pulmonary artery smooth muscle cells (PASMCs). We also used PASMCs from patients with PAH. We applied a combination of immunofluorescence and protein expression studies as well as drug (ACTZ) treatment and in vitro induction of oxidative stress (arsenite) to assess SG formation and SG related markers in experimental PAH and the effect of ACTZ. Results We have discovered that PASMCs from patients with PAH have a higher number of stress granules in response to oxidative stress than cells from normal individuals. We also found that PASMCs from a preclinical model of PAH (Sugen/Hypoxia) have more stress granules and increased SG components in response to oxidative stress compared to normal animals. Further, we found that treatment of PASMCs with ACTZ resulted in lower number of stress granules after cell stress. In addition, we found increased G3BP1 (key component of SG assembly) puncta in alveoli and bronchi and sarcoplasmic G3BP1 puncta in cardiac and soleus muscles from the rat sugen/hypoxia (Su/Hx) model compared to controls and with ACTZ treatment. Conclusions We conclude that there is increased SG formation in PASMCs and tissues in experimental PAH and acetazolamide inhibits stress granule assembly in response to oxidative stress. Further studies are needed to define the role of SG in disease pathogenesis, and evaluate whether targeting stress granules may be effective in restoring normal cellular function and improving PAH.

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Section: Literature Reviewmentioning

confidence: 99%

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

2022

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“…Complete Incomplete State Derman, 1 Lam and Yeh, 2 Monahan, 7 Smallwood and Sondik, 8 Moustafa and Maksoud, 3 Grosfeld-Nir, 9 Ohnishi et al, 10 Lovejoy, 11 Douer and Yechiali, 4 Kurt and Kharoufeh, 5 Maillart, 12 Maehara and Suzuki, 13 Elwany et al 6 Jin et al, 14 Zouch et al 15…”

Section: Deterioration Factor Observationmentioning

confidence: 99%

“…for 0 4 t 1 \ t 2 4 t 2 1. Furthermore, the induction hypothesis given by condition or inequality (15) ensures that…”

Section: Corollary 2 Under Assumptions (A-1) and (A-3)mentioning

confidence: 99%

“…Maehara and Suzuki 13 studied a decision making problem for deteriorating systems with actions keep and replace, and several imperfect repairs. Zouch et al 15 formulated a maintenance problem for a road section using a POMDP for cases in which some deterioration and decision parameters are not observable and developed a maintenance policy that can be solved by a grid-based value iteration algorithm.…”

Section: Introductionmentioning

confidence: 99%

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Optimal control limit policy for age-dependent deteriorating systems under incomplete observations

Jin

Bayarsaikhan

Suzuki

2015

Proceedings of the Institution of Mechanical Engineers, Part O:

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The focus of this study is the optimal decision making problem for an age-dependent deteriorating system in which the deterioration unfolds as a non-stationary Markov process. The true deterioration state of the system cannot be known directly and is assumed to be observed incompletely by a monitor that provides information related to the true deterioration state stochastically. The optimal decision making problem is formulated as a partially observable Markov decision process. The optimal maintenance policy is investigated and the structural properties of the resulting optimal expected cost function are obtained. These structural properties establish the existence of an optimal control limit policy with respect to both the deterioration information vector and the age of the system under intuitively meaningful assumptions. The monotonic property of the control limits is also clarified.

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Planning structural inspection and maintenance policies via dynamic programming and Markov processes. Part II: POMDP implementation

Παπακωνσταντίνου

Shinozuka

2014

Reliability Engineering & System Safety

110

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Optimal resurfacing decisions for road maintenance: A POMDP perspective

Cited by 4 publications

References 18 publications

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Optimal control limit policy for age-dependent deteriorating systems under incomplete observations

Planning structural inspection and maintenance policies via dynamic programming and Markov processes. Part II: POMDP implementation

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Optimal resurfacing decisions for road maintenance: A POMDP perspective

Cited by 4 publications

References 18 publications

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas 1,2, Fotios Spyropoulos1,2,Helen Christou 1,21Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA 2Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas 1,2, Fotios Spyropoulos1,2,Helen Christou 1,21Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA 2Harvard Medical School, Boston, MA 02215, USA

Optimal control limit policy for age-dependent deteriorating systems under incomplete observations

Planning structural inspection and maintenance policies via dynamic programming and Markov processes. Part II: POMDP implementation

Contact Info

Product

Resources

About

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA

Role of Stress Granules in the Pathogenesis of Pulmonary Hypertension Kosmas Kosmas ^1,2, Fotios Spyropoulos^1,2,Helen Christou ^1,2¹Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA ²Harvard Medical School, Boston, MA 02215, USA