We study the primary root growth of wild-type Medicago truncatula plants in heterogeneous environments using 3D time-lapse imaging. The growth medium is a transparent hydrogel consisting of a stiff lower layer and a compliant upper layer. We find that the roots deform into a helical shape just above the gel layer interface before penetrating into the lower layer. This geometry is interpreted as...

One fundamental issue in high-speed wireless local area networks (LANs) is to develop efficient medium access control (MAC) protocols. In this paper, we focus on the performance improvement in both MAC layer and transport layer by using a novel medium access control protocol for high-speed wireless LANs deploying carrier sense multiple access/collision avoidance (CSMA/CA). We first present a re...

numerous date palm orchards in south kerman, iran were investigated during 2001-2003. symptoms of leaf die-back appeared as light brown stripes which began at leaf tips and extended to leaf ends. infected tissues were surface sterilized with 0.05% sodium hypochlorite and, plated on pda medium. isolated fungi were purified using hyphal tip method. on pda medium, fungal colony was fluffy, first c...

lysine is nutritionally essential for humans and animals. it cannot be synthesized biologically in body. children and growing animals have a high requirement of lysine, since it is needed for bone formation. therefore, it must be added to food and feed supplement to improve the protein quality. in addition, lysine has some pharmaceutical applications in the formulation of diets with balanced am...

This paper presents an efficient algorithm for filtering multi-layer depth images (MDIs) in order to produce approximate penumbras. The filtering is performed on a MDI that represents the view from the light source. The algorithm is based upon both ray tracing and the z-buffer shadow algorithm, and is closely related to convolution methods. The method’s effectiveness is demonstrated on especial...

The most important standard in wireless local area networks is IEEE 802.11. This is why much of the research work for the enhancement of wireless network is usually based on the behavior of IEEE 802.11 protocol. However, some of the ways in which IEEE 802.11 medium access control layer behaves is still unreliable to guarantee quality of service. For instance, medium access control layer packet ...

Cultured skin fibroblasts were prepared from two unrelated adult patients with full expressions of Coffin-Lowry syndrome. Glycosaminoglycans (GAGs) were isolated either from the medium or from the cell layer of cultured skin fibroblasts. Two-dimensional electrophoresis of GAG preparations on cellulose acetate film revealed that hyaluronate was the major component both in the medium and in the c...

In this paper, the simulation studies of the radiation characteristics of modified dual segment rectangular dielectric resonator antenna (DSRDRA) in free space and in presence of bio-medium alongwith the absorbed power distribution in a homogenous bio-medium (muscle layer) in direct contact with the proposed antenna are reported at different WiMAX band frequencies. The specific absorption rate ...

The problem of an electromagnetic wave scattered from a random medium layer with rough boundaries is formulated using integral equations which involve two kinds of Green functions. The first one describes the wave scattered by the random medium and the rough boundaries, and the second one which corresponds to the unperturbed Green functions describes the scattering by an homogeneous layer with ...

A flat-layered active medium in which two types of layers with different refractive indices alternate is considered. The thickness of a layer is assumed to be random and large as compared to the wavelength of propagating radiation. A wave propagating along the normal to the layers in such a medium is exponentially enhanced over lengths of the order of many layer thicknesses. In contrast to the ...