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排序方式: 共有1633条查询结果,搜索用时 31 毫秒
31.
The isolation of T cells, followed by differentiation into Regulatory T cells (Tregs), and re‐transplantation into the body has been proposed as a therapeutic option for inflammatory bowel disease. A key requirement for making this a viable therapeutic option is the generation of a large population of Tregs. However, cytokines in the local microenvironment can impact the yield of Tregs during differentiation. As such, experimental design is an essential part of evaluating the importance of different cytokine concentrations for Treg differentiation. However, currently only single, constant concentrations of the cytokines have been investigated. This work addresses this point by performing experimental design in silico which seeks to maximize the predicted induction of Tregs relative to Th17 cells, by selecting an optimal input function for the concentrations of TGF‐β, IL‐2, IL‐6, and IL‐23. While this approach sounds promising, the results show that only marginal improvements in the concentration of Tregs can be achieved for dynamic cytokine profiles as compared to optimal constant concentrations. Since constant concentrations are easier to implement in experiments, it is recommended for this particular system to keep the concentrations constant where IL‐6 should be kept low and high concentrations of TGF‐β, IL‐2, and IL‐23 should be used.Inspec keywords: patient treatment, molecular biophysics, proteins, cellular biophysics, diseasesOther keywords: Tregs relative, optimal input function, dynamic cytokine profiles, optimal constant concentrations, IL‐23, computational maximisation, regulatory T‐cell induction, inflammatory bowel disease, viable therapeutic option, local microenvironment, Treg differentiation, single concentrations, predicted induction, dynamic optimal experimental design, interleukin‐2, IL‐6, transforming growth factor‐β 相似文献
32.
Cuenca Angel García Pedro Albertos Pedro Salt Julián 《International Journal of Control, Automation and Systems》2011,9(6):1194-1202
International Journal of Control, Automation and Systems - This paper presents a Non-Uniform Predictor-Observer (NUPO) based control approach in order to deal with two of the main problems related... 相似文献
33.
This article proposes an optimization–simulation model for planning the transport of supplies to large public infrastructure
works located in congested urban areas. The purpose is to minimize their impact on the environment and on private transportation
users on the local road network. To achieve this goal, the authors propose and solve an optimization problem for minimizing
the total system cost made up of operating costs for various alternatives for taking supplies to the worksite and the costs
supported by private vehicle users as a result of increased congestion due to the movement of heavy goods vehicles transporting
material to the worksite. The proposed optimization problem is a bi-level Math Program model. The upper level defines the
total cost of the system, which is minimized taking into account environmental constraints on atmospheric and noise pollution.
The lower level defines the optimization problem representing the private transportation user behavior, assuming they choose
the route that minimizes their total individual journey costs. Given the special characteristics of the problem, a heuristic
algorithm is proposed for finding optimum solutions. Both the model developed and the specific solution algorithm are applied
to the real case of building a new port at Laredo (Northern Spain). A series of interesting conclusions are obtained from
the corresponding sensitivity analysis. 相似文献
34.
Santi CaballéAuthor Vitae Thanasis DaradoumisAuthor VitaeFatos XhafaAuthor Vitae Angel JuanAuthor Vitae 《Computers in human behavior》2011,27(4):1372-1381
Learning and knowledge building have become critical competences for people in the knowledge society era. In this paper, we propose a sociolinguistic dialogue model for understanding how learning evolves and how cognitive process is constructed in on-line discussions. The knowledge extracted from this model is used to assess participation behavior, knowledge building and performance. The ultimate purpose is to provide effective feedback, evaluation and monitoring to the discussion process. Seven hundred students from the Open University of Catalonia in Spain participated in this study. Results showed that learning and knowledge building may be greatly enhanced by presenting selected knowledge to learners as for their particular skills exhibited during interaction. In addition, this valuable provision of information is used as a meta cognitive tool for tutors and moderators for monitoring and evaluating the discussion process more conveniently. This contribution presents our conceptual model for interaction management as well as key design guidelines and evaluation results. Implications of this study are remarked and further research directions are proposed. 相似文献
35.
36.
Moreno R Garcia MA Puig D Pizarro L Burgeth B Weickert J 《IEEE transactions on pattern analysis and machine intelligence》2011,33(11):2215-2228
This paper proposes two alternative formulations to reduce the high computational complexity of tensor voting, a robust perceptual grouping technique used to extract salient information from noisy data. The first scheme consists of numerical approximations of the votes, which have been derived from an in-depth analysis of the plate and ball voting processes. The second scheme simplifies the formulation while keeping the same perceptual meaning of the original tensor voting: The stick tensor voting and the stick component of the plate tensor voting must reinforce surfaceness, the plate components of both the plate and ball tensor voting must boost curveness, whereas junctionness must be strengthened by the ball component of the ball tensor voting. Two new parameters have been proposed for the second formulation in order to control the potentially conflictive influence of the stick component of the plate vote and the ball component of the ball vote. Results show that the proposed formulations can be used in applications where efficiency is an issue since they have a complexity of order O(1). Moreover, the second proposed formulation has been shown to be more appropriate than the original tensor voting for estimating saliencies by appropriately setting the two new parameters. 相似文献
37.
Angel Rivas Casado Rafael Martinez‐Tomás Antonio Fernández‐Caballero 《Expert Systems》2011,28(5):488-501
This work presents a multi‐agent system for knowledge‐based high‐level event composition, which interprets activities, behaviour and situations semantically in a scenario with multi‐sensory monitoring. A perception agent (plurisensory agent and visual agent)‐based structure is presented. The agents process the sensor information and identify (agent decision system) significant changes in the monitored signals, which they send as simple events to the composition agent that searches for and identifies pre‐defined patterns as higher‐level semantic composed events. The structure has a methodology and a set of tools that facilitate its development and application to different fields without having to start from scratch. This creates an environment to develop knowledge‐based systems generally for event composition. The application task of our work is surveillance, and event composition/inference examples are shown which characterize an alarming situation in the scene and resolve identification and tracking problems of people in the scenario being monitored. 相似文献
38.
MA Bloomberg HS Jordan KO Angel MH Bailit KJ Goonan J Straus 《Canadian Metallurgical Quarterly》1993,19(12):586-595
This article describes a collaborative effort between a major health care purchaser, three area health maintenance organizations, and a state Medicaid agency to develop clinical indicators as the basis for a comparison database. Some of the difficulties in developing a "common yardstick" of quality and value are candidly discussed. 相似文献
39.
Adalberto Llarena Jesus Savage Angel Kuri Boris Escalante-Ramírez 《Journal of Intelligent and Robotic Systems》2012,66(1-2):75-109
This paper proposes an approach that solves the Robot Localization problem by using a conditional state-transition Hidden Markov Model (HMM). Through the use of Self Organized Maps (SOMs) a Tolerant Observation Model (TOM) is built, while odometer-dependent transition probabilities are used for building an Odometer-Dependent Motion Model (ODMM). By using the Viterbi Algorithm and establishing a trigger value when evaluating the state-transition updates, the presented approach can easily take care of Position Tracking (PT), Global Localization (GL) and Robot Kidnapping (RK) with an ease of implementation difficult to achieve in most of the state-of-the-art localization algorithms. Also, an optimization is presented to allow the algorithm to run in standard microprocessors in real time, without the need of huge probability gridmaps. 相似文献
40.
Jose de Jesus Rubio Martin Salazar Angel D. Gomez Raul Lugo 《Neural computing & applications》2012,21(7):1491-1500
The control of the relative humidity and the temperature is important for the birds to be born. It is not easy to control the relative humidity, but it is possible to obtain the measure of the relative humidity as a consequence of the control of the temperature in a bird incubator. In this article, (1) the mathematical model for the control of temperature in the bird incubator is presented, (2) a functional network to approximate the relative humidity behavior in the bird incubator is proposed, (3) a control for the temperature in the bird incubator is proposed, the error of the proportional control applied to the mathematical model of the temperature of the bird incubator is assured to be uniformly stable, (4) the comparison results of four classic control laws for the control of the temperature considering the proposed mathematical model of the temperature and the functional network to approximate the relative humidity behavior in the bird incubator are presented. 相似文献