This paper asks a new question： how can we control the collective behavior of self-organized multi-agent systems？ We try to answer the question by proposing a new notion called ＇Soft Control＇ which keeps the local...This paper asks a new question： how can we control the collective behavior of self-organized multi-agent systems？ We try to answer the question by proposing a new notion called ＇Soft Control＇ which keeps the local rule of the existing agents in the system. We show the feasibility of soft control by a case study. Consider the simple but typical distributed multi-agent model proposed by Vicsek et al. for flocking of birds： each agent moves with the same speed but with different headings which are updated using a local rule based on the average of its own heading and the headings of its neighbors. Most studies of this model are about the self-organized collective behavior, such as synchronization of headings. We want to intervene in the collective behavior （headings） of the group by soft control. A specified method is to add a special agent, called a ＇Shill＇, which can be controlled by us but is treated as an ordinary agent by other agents. We construct a control law for the shill so that it can synchronize the whole group to an objective heading. This control law is proved to be effective analytically and numerieally. Note that soft control is different from the approach of distributed control. It is a natural way to intervene in the distributed systems. It may bring out many interesting issues and challenges on the control of complex systems.展开更多
At the cellular level, reduced kidney perfusion in atherosclerotic renal arthery disease (ARVD), induces hypoxia, activation of the renin-angiotensin-aldosterone system (RAAS) and cytokine activation. Impaired blood f...At the cellular level, reduced kidney perfusion in atherosclerotic renal arthery disease (ARVD), induces hypoxia, activation of the renin-angiotensin-aldosterone system (RAAS) and cytokine activation. Impaired blood flow in the kidneys creates a microenvironment triggering significant cytokine production, contributing to vascular damage and endothelial disfunction. Interactions between cytokines and endothelial, glomerular, and tubular cells often result in increased vessel permeability, and fibrosis, and contribute to the development of chronic kidney disease (CKD). Molecules such as endothelins, prostaglandins, and nitric oxide play a crucial role at the molecular level. The imbalance between vasoconstrictor and vasodilator factors contributes to vascular dysfunction. Oxidative stress and inflammatory processes at the cellular level contribute to endothelial damage and structural changes in blood vessels. Mineralocorticoid receptor antagonists (MRAs) therapy in the context of ARVD holds promise in reducing fibrosis, promoting angiogenesis and enhancing overall outcomes in patients with this pathology. Recent data also indicates the antioxidative, anti-inflammatory, and antifibrotic effects of SGLT2 inhibitors. They reduce oxidative stress caused by hypoxic conditions and enhance renal perfusion, contributing to the preservation of cellular function. Studies employing Blood Oxygen Level-Dependent (BOLD) imaging have identified adaptations to reduced blood flow, volume, and glomerular filtration rate in post-stenotic kidneys that preserve oxygenation in the medulla and cortex during medical therapy. Data from the literature indicate that despite the partial recovery of renal hypoxia and restoration of blood flow after revascularization, inflammatory cytokines and injury biomarkers remain elevated, and the glomerular filtration rate (GFR) does not recover in ARVD. Restoration of vascular patency alone has failed to reverse tubulointerstitial damage and partially explains the limited clinical benefit of renal stent展开更多
Human presence and activities have profoundly altered animals’habitats,exposing them to greater risks but also providing new opportunities and resources.The animals’capacity to effectively navigate and strike a bala...Human presence and activities have profoundly altered animals’habitats,exposing them to greater risks but also providing new opportunities and resources.The animals’capacity to effectively navigate and strike a balance between risks and benefts is crucial for their survival in the Anthropocene era.Red foxes(Vulpes vulpes),adept urban dwellers,exhibit behavioral plasticity in human-altered environments.We investigated variations in detection frequency on trail cameras and the behavioral responses(explorative,bold,and fearful)of wild red foxes living along an urbanization gradient when exposed to a metal bin initially presented clean and then flled with anthropogenic food.All fox populations displayed an increased interest and similar explorative behavioral responses toward the anthropogenic food source,irrespective of the urbanization gradient.Despite no impact on explorative behaviors,foxes in more urbanized areas initially showed heightened fear toward the empty bin,indicating increased apprehension toward novel objects.However,this fear diminished over time,and in the presence of food,urban foxes displayed slightly reduced fear compared with their less urban counterparts.Our results highlight foxes’potential for adaptability to human landscapes,additionally underscoring the nuanced interplay of fear and explorative behavioral response of populations living along the urbanization gradient.展开更多
Quantification of brain oxygenation and metabolism,both of which are indicators of the level of brain activity,plays a vital role in understanding the cerebral perfusion and the pathophysiology of brain disorders.Magn...Quantification of brain oxygenation and metabolism,both of which are indicators of the level of brain activity,plays a vital role in understanding the cerebral perfusion and the pathophysiology of brain disorders.Magnetic resonance imaging(MRI),a widely used clinical imaging technique,which is very sensitive to magnetic susceptibility,has the possibility of substitut-ing positron emission tomography(PET)in measuring oxygen metabolism.This review mainly focuses on the quantitative blood oxygenation level-dependent(qBOLD)method for the evaluation of oxygen extraction fraction(OEF)in the brain.Here,we review the theoretic basis of qBOLD,as well as existing acquisition and quantification methods.Some published clinical studies are also presented,and the pros and cons of qBOLD method are discussed as well.展开更多
Ink freehand brushwork is the soul and the highest level of artistic spirit in art categories such as painting and sculpture.Sculpture art and Chinese ink painting art have their own commonalities.I attempted to inves...Ink freehand brushwork is the soul and the highest level of artistic spirit in art categories such as painting and sculpture.Sculpture art and Chinese ink painting art have their own commonalities.I attempted to investigate the stone carvings of Huo Qubing’s tomb in the Western Han Dynasty,combined with Tang Dynasty tomb carvings,which greatly helped me in the creation of Chinese ink painting art.I drew inspiration and nutrients from it,and realized what is art.What is the spirit of art?You can find the answer from it.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.20336040.No.60574068.and No.60221301).
文摘This paper asks a new question： how can we control the collective behavior of self-organized multi-agent systems？ We try to answer the question by proposing a new notion called ＇Soft Control＇ which keeps the local rule of the existing agents in the system. We show the feasibility of soft control by a case study. Consider the simple but typical distributed multi-agent model proposed by Vicsek et al. for flocking of birds： each agent moves with the same speed but with different headings which are updated using a local rule based on the average of its own heading and the headings of its neighbors. Most studies of this model are about the self-organized collective behavior, such as synchronization of headings. We want to intervene in the collective behavior （headings） of the group by soft control. A specified method is to add a special agent, called a ＇Shill＇, which can be controlled by us but is treated as an ordinary agent by other agents. We construct a control law for the shill so that it can synchronize the whole group to an objective heading. This control law is proved to be effective analytically and numerieally. Note that soft control is different from the approach of distributed control. It is a natural way to intervene in the distributed systems. It may bring out many interesting issues and challenges on the control of complex systems.
文摘At the cellular level, reduced kidney perfusion in atherosclerotic renal arthery disease (ARVD), induces hypoxia, activation of the renin-angiotensin-aldosterone system (RAAS) and cytokine activation. Impaired blood flow in the kidneys creates a microenvironment triggering significant cytokine production, contributing to vascular damage and endothelial disfunction. Interactions between cytokines and endothelial, glomerular, and tubular cells often result in increased vessel permeability, and fibrosis, and contribute to the development of chronic kidney disease (CKD). Molecules such as endothelins, prostaglandins, and nitric oxide play a crucial role at the molecular level. The imbalance between vasoconstrictor and vasodilator factors contributes to vascular dysfunction. Oxidative stress and inflammatory processes at the cellular level contribute to endothelial damage and structural changes in blood vessels. Mineralocorticoid receptor antagonists (MRAs) therapy in the context of ARVD holds promise in reducing fibrosis, promoting angiogenesis and enhancing overall outcomes in patients with this pathology. Recent data also indicates the antioxidative, anti-inflammatory, and antifibrotic effects of SGLT2 inhibitors. They reduce oxidative stress caused by hypoxic conditions and enhance renal perfusion, contributing to the preservation of cellular function. Studies employing Blood Oxygen Level-Dependent (BOLD) imaging have identified adaptations to reduced blood flow, volume, and glomerular filtration rate in post-stenotic kidneys that preserve oxygenation in the medulla and cortex during medical therapy. Data from the literature indicate that despite the partial recovery of renal hypoxia and restoration of blood flow after revascularization, inflammatory cytokines and injury biomarkers remain elevated, and the glomerular filtration rate (GFR) does not recover in ARVD. Restoration of vascular patency alone has failed to reverse tubulointerstitial damage and partially explains the limited clinical benefit of renal stent
基金The study was funded by the Vienna Science and Technology Fund(WWTF)[10.47379/ESR20009]RB was partially financed by the WWTF and partially financed under the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.4 Call for tender No.3138 of 16 December 2021,rectified by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union Next Generation EU.MAwas financed by Fondo di Ateneo per la Ricerca 2020(University of Sassari).
文摘Human presence and activities have profoundly altered animals’habitats,exposing them to greater risks but also providing new opportunities and resources.The animals’capacity to effectively navigate and strike a balance between risks and benefts is crucial for their survival in the Anthropocene era.Red foxes(Vulpes vulpes),adept urban dwellers,exhibit behavioral plasticity in human-altered environments.We investigated variations in detection frequency on trail cameras and the behavioral responses(explorative,bold,and fearful)of wild red foxes living along an urbanization gradient when exposed to a metal bin initially presented clean and then flled with anthropogenic food.All fox populations displayed an increased interest and similar explorative behavioral responses toward the anthropogenic food source,irrespective of the urbanization gradient.Despite no impact on explorative behaviors,foxes in more urbanized areas initially showed heightened fear toward the empty bin,indicating increased apprehension toward novel objects.However,this fear diminished over time,and in the presence of food,urban foxes displayed slightly reduced fear compared with their less urban counterparts.Our results highlight foxes’potential for adaptability to human landscapes,additionally underscoring the nuanced interplay of fear and explorative behavioral response of populations living along the urbanization gradient.
基金supported by the National Natural Science Foundation of China(No.81971583)National Key R&D Program of China(No.2018YFC1312900)+1 种基金Shanghai Natural Science Foundation(No.20ZR1406400)Shanghai Municipal Science and Technology Major Project(No.2017SHZDZX01,No.2018SHZDZX01)and ZJLab.
文摘Quantification of brain oxygenation and metabolism,both of which are indicators of the level of brain activity,plays a vital role in understanding the cerebral perfusion and the pathophysiology of brain disorders.Magnetic resonance imaging(MRI),a widely used clinical imaging technique,which is very sensitive to magnetic susceptibility,has the possibility of substitut-ing positron emission tomography(PET)in measuring oxygen metabolism.This review mainly focuses on the quantitative blood oxygenation level-dependent(qBOLD)method for the evaluation of oxygen extraction fraction(OEF)in the brain.Here,we review the theoretic basis of qBOLD,as well as existing acquisition and quantification methods.Some published clinical studies are also presented,and the pros and cons of qBOLD method are discussed as well.
基金This article is part of the research results of the National Social Science Foundation’s major project in the field of art(Project number 21ZD12).
文摘Ink freehand brushwork is the soul and the highest level of artistic spirit in art categories such as painting and sculpture.Sculpture art and Chinese ink painting art have their own commonalities.I attempted to investigate the stone carvings of Huo Qubing’s tomb in the Western Han Dynasty,combined with Tang Dynasty tomb carvings,which greatly helped me in the creation of Chinese ink painting art.I drew inspiration and nutrients from it,and realized what is art.What is the spirit of art?You can find the answer from it.
