Self-regulation mechanism of an ecosystem in a non-Gaussian fluctuation regime

1996 ◽  
Vol 54 (1) ◽  
pp. 706-716 ◽  
Author(s):  
S. Ciuchi ◽  
F. de Pasquale ◽  
B. Spagnolo
Keyword(s):  
Self Regulation ◽  
Regulation Mechanism ◽  
Non Gaussian

scholarly journals Study of the Seasonal Effect of Building Shadows on Urban Land Surface Temperatures Based on Remote Sensing Data

2019 ◽  
Vol 11 (5) ◽  
pp. 497 ◽  
Author(s):  
Ke Yu ◽  
Yunhao Chen ◽  
Dandan Wang ◽  
Zixuan Chen ◽  
Adu Gong ◽  
...  
Keyword(s):  
Land Surface ◽  
Self Regulation ◽  
Central Area ◽  
Urban Land ◽  
Cooling Effect ◽  
Sensor Data ◽  
Seasonal Effect ◽  
Landsat 8 ◽  
Regulation Mechanism ◽  
The Relationship

Building shadows (BSs) frequently occur in urban areas, and their area and distribution display strong seasonal variations that significantly influence the urban land surface temperature (LST). However, it remains unclear how BSs affect the LST at the city scale because it is difficult to extract the shaded area at the subpixel scale and to connect such areas with the LST at the pixel scale. In this study, we combined the sun angle, building height, building footprint and building occlusion to extract the seasonal spatial distribution of BSs in the central area of Beijing. The effect of BSs on the LST was analyzed using LST retrieved from Landsat-8 thermal infrared sensor data. First, the relationship between the LST patch fragmentation and proportion of BSs in the sample areas was modeled without vegetation. Then, we quantitatively studied the mitigated intensity of the LST in pure impervious surfaces (IS) and vegetation pixels covered by BSs; next, we analyzed the LST sensitivity of these pixels to BSs. The results showed that the existence of BSs influences the fragmentation of the low LST patches strongly from summer to winter. On the other hand, pure IS pixels totally covered by BSs experienced a greater cooling effect, with 3.16 K on 10 July, and the lowest cooling occurred between 14 and 25 December, with a mean of 1.24 K. Without considering the relationship in winter, the LST is nonlinearly correlated to the building shadows ratio (BSR) in pixels, and an approximate 10% increase in the BSR resulted in decreases in the LST of approximately 0.33 K (mean of 16 April and 10 May), 0.37 K (10 July) and 0.24 K (28 September) for pure IS pixels, and 0.18 K, 0.20 K and 0.15 K, respectively, for pure vegetation pixels. Further analysis indicates that the LST of pure IS pixels is more sensitive to BSs than that of vegetation because the self-regulation mechanism of vegetation reduces the cooling effect of BSs. These findings can help urban planners understand the cooling characteristics of BSs and design suitable urban forms to resist urban heat islands (UHIs).

The impact of capillary dilation on the distribution of red blood cells in artificial networks

2015 ◽  
Vol 308 (7) ◽  
pp. H733-H742 ◽  
Author(s):  
Franca Schmid ◽  
Johannes Reichold ◽  
Bruno Weber ◽  
Patrick Jenny
Keyword(s):  
Flow Rate ◽  
Self Regulation ◽  
Blood Flow Rate ◽  
Regulation Mechanism ◽  
Parent Vessel ◽  
Capillary Networks ◽  
Dilation Factor ◽  
Network Simulations ◽  
The Impact ◽  
Capillary Dilation

Recent studies suggest that pericytes around capillaries are contractile and able to alter the diameter of capillaries. To investigate the effects of capillary dilation on network dynamics, we performed simulations in artificial capillary networks of different sizes and complexities. The unequal partition of hematocrit at diverging bifurcations was modeled by assuming that each red blood cell (RBC) enters the branch with the faster instantaneous flow. Network simulations with and without RBCs were performed to investigate the effect of local dilations. The results showed that the increase in flow rate due to capillary dilation was less when the effects of RBCs are included. For bifurcations with sufficient RBCs in the parent vessel and nearly equal flows in the branches, the flow rate in the dilated branch did not increase. Instead, a self-regulation of flow was observed due to accumulation of RBCs in the dilated capillary. A parametric study was performed to examine the dependence on initial capillary diameter, dilation factor, and tube hematocrit. Furthermore, the conditions needed for an efficient self-regulation mechanism are discussed. The results support the hypothesis that RBCs play a significant role for the fluid dynamics in capillary networks and that it is crucial to consider the blood flow rate and the distribution of RBCs to understand the supply of oxygen in the vasculature. Furthermore, our results suggest that capillary dilation/constriction offers the potential of being an efficient mechanism to alter the distribution of RBCs locally and hence could be important for the local regulation of oxygen delivery.

Red blood cell distribution in simplified capillary networks

2010 ◽  
Vol 368 (1921) ◽  
pp. 2897-2918 ◽  
Author(s):  
Dominik Obrist ◽  
Bruno Weber ◽  
Alfred Buck ◽  
Patrick Jenny
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Discrete Model ◽  
Self Regulation ◽  
Capillary Network ◽  
Human Organism ◽  
Regulation Mechanism ◽  
Special Role ◽  
Detailed Model ◽  
Capillary Networks

A detailed model of red blood cell (RBC) transport in a capillary network is an indispensable element of a comprehensive model for the supply of the human organism with oxygen and nutrients. In this paper, we introduce a two-phase model for the perfusion of a capillary network. This model accounts for the special role of RBCs, which have a strong influence on network dynamics. Analytical results and numerical simulations with a discrete model and a generic network topology indicate that there exists a local self-regulation mechanism for the flow rates and a global de-mixing process that leads to an inhomogeneous haematocrit distribution. Based on the results from the discrete model, we formulate an efficient algorithm suitable for computing the pressure and flow field as well as a continuous haematocrit distribution in large capillary networks at steady state.

scholarly journals Self-Regulation Mechanism: A Principle for Continual Autonomous Learning in Open-Ended Environments

2011 ◽  
Vol 29 (1) ◽  
pp. 77-88
Author(s):  
Yukiko Hoshino ◽  
Kenta Kawamoto ◽  
Kuniaki Noda ◽  
Kohtaro Sabe
Keyword(s):  
Self Regulation ◽  
Autonomous Learning ◽  
Regulation Mechanism

scholarly journals Life positions in self-regulation of life activity of the youth

2021 ◽  
Vol 12 (3) ◽  
pp. 79-98
Author(s):  
Yulia A. Zubok ◽  
Vladimir I. Chuprov ◽  
Alexander S. Lyubutov ◽  
Oleg V. Sorokin
Keyword(s):  
Young People ◽  
Urban Space ◽  
Self Regulation ◽  
Social Activity ◽  
Semantic Content ◽  
Regulatory Function ◽  
Regulation Mechanism ◽  
Sociological Research ◽  
Life Meaning ◽  
Life Activity

Recently, the topic of the life positions of young people attracts more attention due to the activation of youth in the socio-political space of the society life: defending their right to participate in the formation of urban space, participation in volunteer and environmental movement, for the preservation of cultural heritage and values ​​of a various spectrum: from traditional to modern. The nature of these and other types of activity is regulated by a life position, reflecting the understanding by different groups of young people of themselves, the meaning of their life, their role in society. The article examines the essence of the life position of youth, the specifics of its formation within the existing semantic space of reality and the relationship with social activity. On the basis of the concept of socio-cultural self-regulation of life activity developed by the Center for Sociology of Youth of the Institute of Socio-Political Research FCTAS RAS and the data obtained in the course of the Center for Sociological Research, the author analyses the connection between the life position of young people and age, the level of material status and education, as well as with regional living conditions. The interconnection between the life positions of young people and their ideological attitudes towards individualism and collectivism, trust and distrust of others are described. By using structural and taxonomic modeling of the life process of young people, the interrelationships of their life positions with elements of the socio-cultural mechanism of self-regulation are considered. Thus, the author analyzes the connections between the core of the taxon of habitus of active and passive life positions of young people with archetypes, mental traits, modern features and life-meaning values, types of youth cultures. It has been established that the regulatory function of an active life position is realiszed through both traditional and modern elements of the self-regulation mechanism: by archetypes of glory and idealzation of the past, on the one hand, and rationalism, openness to everything foreign, attitude to the country as a place of residence, on the other. In turn, the regulatory function of a passive life position is predominantly formed under the influence of the conditions of the vital activities of the young people, and the role of youth types of culture and life-meaning values ​​is reduced to their awareness of the semantic content of the formed habitual attitude. The article also analyzes the indicators of the social activity of young people based on their connection with the worldview semantic attitudes.

scholarly journals Politik Media dalam Transisi Politik: Dari Kontrol Negara Menuju Self-Regulation Mechanism

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Hermin Indah Wahyuni
Keyword(s):  
New Media ◽  
Freedom Of Expression ◽  
Self Regulation ◽  
Regulation Mechanism ◽  
Political Transformation ◽  
New Era ◽  
The Public ◽  
Voluntary Regulation ◽  
Media System ◽  
Media Politics

Abstract: The political transformation in 1998 introduced a new era of Indonesian media which respects the public interest and implements a democratic model. The changing led to a new media-politics that have democratic character. This article will focus on the self regulation mechanism that becomes very popular in democratic mass media system. Those favouring self-regulation mechanism have usually justified it on the grounds that it is less damaging to freedom of expression than legal control. However this mechanism is not a panacea for all ills, because self-regulation can only work if certain pre-conditions are met. The analysis will be done by several conceptual frames, i.e: the concept of media in political transition, concept of media politics, self regulation mechanism, and statutory vs voluntary regulation.

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