| 1. |
- Jönsson, Henrik, et al.
(författare)
-
Modeling the organization of the WUSCHEL expression domain in the shoot apical meristem
- 2005
-
Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1460-2059. ; 21:Suppl 1, s. 232-240
-
Tidskriftsartikel (refereegranskat)abstract
- Motivation: The above-ground tissues of higher plants are generated from a small region of cells situated at the plant apex called the shoot apical meristem. An important genetic control circuit modulating the size of the Arabidopsis thaliana meristem is a feed-back network between the CLAVATA3 and WUSCHEL genes. Although the expression patterns for these genes do not overlap, WUSCHEL activity is both necessary and sufficient (when expressed ectopically) for the induction of CLAVATA3 expression. However, upregulation of CLAVATA3 in conjunction with the receptor kinase CLAVATA1 results in the downregulation of WUSCHEL. Despite much work, experimental data for this network are incomplete and additional hypotheses are needed to explain the spatial locations and dynamics of these expression domains. Predictive mathematical models describing the system should provide a useful tool for investigating and discriminating among possible hypotheses, by determining which hypotheses best explain observed gene expression dynamics. Results: We are developing a method using in vivo live confocal microscopy to capture quantitative gene expression data and create templates for computational models. We present two models accounting for the organization of the WUSCHEL expression domain. Our preferred model uses a reaction-diffusion mechanism in which an activator induces WUSCHEL expression. This model is able to organize the WUSCHEL expression domain. In addition, the model predicts the dynamical reorganization seen in experiments where cells, including the WUSCHEL domain, are ablated, and it also predicts the spatial expansion of the WUSCHEL domain resulting from removal of the CLAVATA3 signal.
|
|
| 2. |
- Chattopadhyay, G., et al.
(författare)
-
Decision on economical rail grinding interval for controlling rolling contact fatigue
- 2005
-
Ingår i: International Transactions in Operational Research. - : Wiley. - 0969-6016 .- 1475-3995. ; 12:6, s. 545-558
-
Tidskriftsartikel (refereegranskat)abstract
- Rail players around the world have been increasing axle loads to improve the productivity of freight and heavy haul operations. This has increased the risk of surface cracks at curves because of rolling contact fatigue. Rail grinding has been considered an effective process for controlling these cracks and reducing risks of rail breaks. The complexity of deciding the optimal rail grinding intervals for improving the reliability and safety of rails is because of insufficient understanding of the various factors involved in the crack initiation and propagation process. This paper focuses on identifying the factors influencing rail degradation, developing models for rail failures and analyzing the costs of various grinding intervals for economic decision making. Various costs involved in rail maintenance, such as rail grinding, downtime, inspection, rail failures and derailment, and replacement of worn-out rails, are incorporated into the total cost model developed in this paper. Field data from the rail industry have been used for illustration.
|
|
| 3. |
- Chattopadhyay, G., et al.
(författare)
-
Rail-wheel lubrication : A conceptual decision model
- 2005
-
Ingår i: International Conference on Operations Research Applications in Infrastructure Development in conjunction with the 2005 Annual Convention of Operational Research Society of India (ICORAID-2005-ORSI).
-
Konferensbidrag (refereegranskat)
|
|
| 4. |
|
|
| 5. |
|
|
