Significant recent progress toward understanding directional expansion in diffusely growing plant cells concerns actin. Tools for imaging actin, including both live-cell reporters and fixation protocols, have been improved. Proteins that interact with actin have been identified and their functions probed biochemically and genetically. Specifically, members of the actin-related protein2/3 (ARP2/...

The coordinated growth of epidermal cells in plant leaves creates the characteristic jigsaw puzzle appearance of the pavement cells. Now, Xu et al. (2010) report that AUXIN-BINDING PROTEIN 1 mediates auxin activation of two GTPase pathways that antagonistically control planar morphogenesis of leaf epidermal cells to create this distinctive pattern.

Deterioration models are important and essential part of any Pavement Management System (PMS). These models are used to predict future pavement situation based on existence condition, parameters causing deterioration and implications of various maintenance and rehabilitation policies on pavement. The majority of these models are based on roughness which is one of the most important indices in p...

Rubblization is one of the surface preparation techniques before placing a Hot Mix Asphalt (HMA) overlay that involves breaking the Portland Cement Concrete (PCC) pavement into pieces. This paper describes the structural assessment related to the long term performance of rubblized concrete pavements in Iowa. The structural performance of seven representative in-service rubblized concrete paveme...

in this study, an artificial neural network was developed in order to analyze flexible pavement structure anddetermine its critical responses under the influence of standard axle loading. in doing so, more than 10000four-layered flexible pavement sections composed of asphalt concrete layer, base layer, subbase layer, andsubgrade soil were analyzed under the impact of standard axle loading. pave...

The use of falling weight deflectometer—based backcalculation techniques to determine pavement layer moduli is a cost-effective and widely used method for the structural evaluation of an existing pavement. The nonlinear stress-sensitive response of pavement geomaterials has been well established, and mechanisticbased pavement design can be improved by inclusion of these nonlinear material prope...

To measure stiffness of the compacted pavement, practitioners use the Compaction Meter Value (CMV); a ratio between the amplitude for the first harmonic of the compactor’s acceleration and the amplitude corresponding to the vibration frequency. Numerous experiments show that CMV is highly correlated with the pavement stiffness, but as of now, there is no convincing theoretical explanation for t...

IN T R O D U C T IO N T he In d iana D epartm ent of Highways has em barked upon es­ tab lish ing a Pavem ent M anagem ent System (PMS). As a p a rt of this, the Jo in t H ighway R esearch Project has had an on-going research p ro ­ ject for the past several years dealing with m ethods of m easuring pave­ m ent condition in Ind iana . Research at P urdue on the use of roughness m easuring devic...

One of the main components of pavement management system (PMS) is pavement evaluation. Several indices have been defined for the evaluation of existing pavement. The Pavement Condition Index (PCI) is a common index used for pavement evaluation. In order to calculate PCI, a significant volume of condition data -based on distress surveying- is required. The objective of this research is to reduce...

ABSTRACT: Most pavement maintenance management systems tend to be either non-analytical databases or statistical correlation models. However, pavement maintenance is part of a complex system (comprising the road pavement, the environment, diverse users, the maintenance authority and Local/State/Federal Governments) that has significant feedbacks, making it a suitable field for system dynamics e...