The role of NCX in initiation and expansion of astroglial Ca2+ events in a distributed model

2020 ◽  
Author(s):  
Andrey Y. Verisokin ◽  
Darya V. Verveyko ◽  
Dmitry E. Postnov ◽  
Alexey R. Brazhe
Keyword(s):  
Distributed Model

scholarly journals Doctoral Students’ Academic Supervision: A Systematic Review of Approaches to Conceptualization and Empirical Analysis

2021 ◽  
Vol 25 (1) ◽  
pp. 49-61
Author(s):  
A. V. Grigoryeva ◽  
E. A. Terentev
Keyword(s):  
Systematic Review ◽  
Doctoral Students ◽  
Doctoral Student ◽  
Active Role ◽  
Educational Process ◽  
Distributed Model ◽  
Academic World ◽  
Student Centered ◽  
Key Points

The article presents a systematic review of theoretical and methodological approaches to the conceptualization and empirical study of doctoral students’ supervision. Three approaches (mentoring, doctoral student-centered, and environmental) are distinguished depending on the main responsibility for the result. The mentoring approach attributes the responsibility for the result to the supervisor. This approach is generally associated with the so-called «apprentice model», which understands the doctoral student as a «neophyte» introduced to the academic world by the supervisor. The doctoral student-centered approach is characterized by imposing the responsibility mainly on the doctoral student. This approach assumes a more active role of the doctoral student and goes back to the models of student-centered pedagogy. The environmental approach focuses on studying the role of the environment and on the issues related to the academic and social integration of doctoral students. All these approaches notably have a number of limitations due to their concentration on certain factors of the educational process and less attention to the dynamic and relative nature of various aspects of academic supervision and its relationship with the effectiveness of doctoral training. There is substantiated the importance of developing a relational approach, which would synthesize the key points of the three approaches considered, and assume a distributed model of responsibility within the academic supervision. As it understands «learning alliances» more broadly than pairs or teams of scientific supervisors and graduate students, this approach focuses not only on the activity of individual actors, but also on the system of relationships between them.

Role of adenosine in norepinephrine-induced coronary vasodilation

1997 ◽  
Vol 273 (2) ◽  
pp. H557-H565 ◽  
Author(s):  
R. Van Bibber ◽  
D. W. Stepp ◽  
K. Kroll ◽  
E. O. Feigl
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Coronary Blood Flow ◽  
Adenosine Receptor ◽  
Myocardial Oxygen Consumption ◽  
Temporal Correlation ◽  
Distributed Model ◽  
Receptor Blockade ◽  
Adenosine Concentration

Adenosine has been postulated to be the physiological transmitter coupling increases in coronary blood flow to increases in myocardial metabolism. The purpose of this experiment was to evaluate the role of adenosine in the coronary hyperemia due to norepinephrine. In 11 anesthetized, closed-chest canine preparations, the left main coronary artery was cannulated and perfused with blood at 100 mmHg. Coronary blood flow and myocardial oxygen consumption were measured, and interstitial adenosine concentration was estimated from arterial and coronary venous measurements using a distributed model. Adenosine receptor blockade with 8-phenyltheophylline (8-PT) was used to shift the adenosine dose-response curve 12-fold. During intracoronary norepinephrine infusion, coronary blood flow and myocardial oxygen consumption increased similarly before and after 8-PT, demonstrating a lack of an effect from the adenosine receptor blockade. Before 8-PT, estimated interstitial adenosine increased to a vasoactive concentration (220 nM); however, the temporal correlation with coronary blood flow was poor. After 8-PT, a similar increase in estimated interstitial adenosine was found, demonstrating that there was no augmentation in adenosine concentration to overcome the adenosine receptor blockade. Thus adenosine could not be responsible for the increase in coronary blood flow after adenosine receptor blockade and therefore is not required for norepinephrine-induced hyperemia.

Analytical upscaling of fill-and-spill hydrology

2020 ◽  
Author(s):  
James Craig ◽  
Mahkameh Taheri ◽  
Mark Ranjram
Keyword(s):  
Probability Distributions ◽  
Branching Ratio ◽  
Distributed Model ◽  
Rainfall Runoff ◽  
Heterogeneous Landscapes ◽  
Wetland Complex ◽  
Event Model ◽  
The Individual ◽  
Local Storage

<p>Fill-and-spill hydrology, where landscape storage features such as bogs, lakes, prairie sloughs, or surface depressions impound and then dynamically release water after a deficit is filled, has received increased attention in recent years. In systems dominated by fill-and-spill, the contributing runoff area is a function of both local storage deficit and the degree and nature of connectivity between storage features. Here, a closed-form analytical upscaled probabilistic event model of runoff response from thousands of bog cascades in a wetland complex is developed and demonstrated. The efficient mathematical model represents the individual wetland contributing area, runoff coefficient, and pre-event deficit of each bog as probability distributions that may be estimated via a combination of spatial analysis and field observation.</p><p>The model is here used to explore the impacts of cascade depth, network branching ratio, local contributing area, and deficit distribution on runoff response. The upscaling results provide insight into the critical runoff characteristics and emergent behaviour of watersheds typified by fill-and-spill hydrology and clarify the role of ‘gatekeeper’ storage features at large scales and for systems with shallow cascade depth. The mathematical solution is found to be a generalization of the well-known PDM (Probability Distributed Model) and Xinanxiang probabilistic runoff models for the specific case where network depth is one and contributing area of each storage feature is zero, and therefore can be readily generalized to support simulation of classical rainfall-runoff responses in heterogeneous landscapes. The results of the model enable exploration of scaling and distribution effects upon catchment runoff in basins influenced by fill-and-spill hydrology.</p>

scholarly journals Influence of snow surface processes on soil moisture dynamics and streamflow generation in alpine catchments

2017 ◽  
Author(s):  
Nander Wever ◽  
Francesco Comola ◽  
Mathias Bavay ◽  
Michael Lehning
Keyword(s):  
Soil Moisture ◽  
Snow Cover ◽  
Soil Freezing ◽  
Distributed Model ◽  
Stream Network ◽  
Model Framework ◽  
Soil Layers ◽  
Flood Risks ◽  
Moisture State

Abstract. The assessment of flood risks in alpine, snow covered catchments requires an understanding of the linkage between the snow cover, soil and discharge in the stream network. Here, we apply the comprehensive, distributed model Alpine3D to investigate the role of soil moisture in the predisposition of a catchment to high flows from rainfall and snow melt for the Dischma catchment in East Switzerland. The recently updated soil module of the physics based, multi-layer snow cover model SNOWPACK, which solves the surface energy and mass balance in Alpine3D, is verified against soil moisture measurements at seven sites and various depths inside and in close proximity of the Dischma catchment. Measurements and simulations in such terrain are difficult and consequently, soil moisture was simulated with varying degrees of success. Differences between simulated and measured soil moisture mainly arises from an overestimation of soil freezing and an absence of a ground water description in the model. Both were found to have an influence in the soil moisture measurements. Streamflow simulations performed with a spatially-explicit hydrological model using a travel time distribution approach coupled to Alpine3D provided a closer agreement with observed streamflow at the outlet of the Dischma catchment when including 30 cm of soil layers. Performance decreased when including 2 cm or 60 cm of soil layers. This demonstrates that the role of soil moisture is important to take into account when understanding the relationship between both snowpack runoff and rainfall and catchment discharge in high alpine terrain. Runoff coefficients (i.e., ratio of rainfall over discharge) based on measurements for high rainfall and snowmelt events were found to be dependent on the simulated initial soil moisture state at the onset of an event, further illustrating the important role of soil moisture for the hydrological processes in the catchment. The runoff coefficients using simulated discharge were found to reproduce this dependency and this shows that the Alpine3D model framework can be successfully applied to assess the predisposition of the catchment to flood risks from both snowmelt and rainfall events.

scholarly journals Evolving Collective Behavior in an Artificial Ecology

2001 ◽  
Vol 7 (2) ◽  
pp. 191-209 ◽  
Author(s):  
Christopher R. Ward ◽  
Fernand Gobet ◽  
Graham Kendall
Keyword(s):  
Neural Network ◽  
Collective Behavior ◽  
Fitness Function ◽  
Distributed Model ◽  
Artificial Evolution ◽  
Schooling Behavior ◽  
Group Motion ◽  
Rule Set ◽  
Artificial World

Collective behavior refers to coordinated group motion, common to many animals. The dynamics of a group can be seen as a distributed model, each “animal” applying the same rule set. This study investigates the use of evolved sensory controllers to produce schooling behavior. A set of artificial creatures “live” in an artificial world with hazards and food. Each creature has a simple artificial neural network brain that controls movement in different situations. A chromosome encodes the network structure and weights, which may be combined using artificial evolution with another chromosome, if a creature should choose to mate. Prey and predators coevolve without an explicit fitness function for schooling to produce sophisticated, nondeterministic, behavior. The work highlights the role of species' physiology in understanding behavior and the role of the environment in encouraging the development of sensory systems.

scholarly journals Role of the liver in small-solute transport during peritoneal dialysis.

1994 ◽  
Vol 5 (1) ◽  
pp. 116-120
Author(s):  
M F Flessner ◽  
R L Dedrick
Keyword(s):  
Mass Transfer ◽  
Peritoneal Dialysis ◽  
Surface Area ◽  
Peritoneal Cavity ◽  
Distributed Model ◽  
Blood Capillaries ◽  
Peritoneal Surface ◽  
Small Solute ◽  
Good Agreement

Peritoneal dialysis (PD) is dependent on the transport of water and solutes from the blood capillaries within the tissues that surround the peritoneal cavity. Because of their large blood supply and surface area, the viscera have been considered the most important tissues for PD transport. In animals, however, removal of the gastrointestinal tract decreases PD small-solute mass transfer by only 10 to 27%. To investigate the theoretical basis for these observations, a distributed model of peritoneal transport was extended to take into account the transport characteristics of four tissue groups that surround the cavity: the liver, the hollow viscera, the abdominal wall, and the diaphragm. The mass transfer-area coefficient (MTAC) of sucrose for each tissue was calculated from the following: MTAC = ([D(pa)]0.5)A, where D is the effective solute interstitial diffusivity, pa is the solute transcapillary permeability-area per unit tissue volume, and A is the apparent peritoneal surface area of the tissue. Our results for the adult human predict that the MTAC for the liver is comparable to that of all of the other viscera and makes up 43% of the total MTAC for the peritoneal cavity. The predicted MTAC is 4 cm3/min (plasma) or 6 cm3/min (blood), in good agreement with published values. It is concluded that the liver is responsible for a major portion of the small-solute MTAC. This also explains the earlier observations in eviscerated animals whose PD transport was likely preserved by intact livers.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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