A Role for Human Renal Tubular Epithelial Cells in Direct Allo-Recognition by CD4+ T-Cells and the Effect of Ischemia-Reperfusion

Direct allorecognition is the earliest and most potent immune response against a kidney allograft. Currently, it is thought that passenger donor professional antigen-presenting cells (APCs) are responsible. Further, many studies support that graft ischemia-reperfusion injury increases the probability of acute rejection. We evaluated the possible role of primary human proximal renal tubular epithelial cells (RPTECs) in direct allorecognition by CD4+ T-cells and the effect of anoxia-reoxygenation. In cell culture, we detected that RPTECs express all the required molecules for CD4+ T-cell activation (HLA-DR, CD80, and ICAM-1). Anoxia-reoxygenation decreased HLA-DR and CD80 but increased ICAM-1. Following this, RPTECs were co-cultured with alloreactive CD4+ T-cells. In T-cells, zeta chain phosphorylation and c-Myc increased, indicating activation of T-cell receptor and co-stimulation signal transduction pathways, respectively. T-cell proliferation assessed with bromodeoxyuridine assay and with the marker Ki-67 increased. Previous culture of RPTECs under anoxia raised all the above parameters in T-cells. FOXP3 remained unaffected in all cases, signifying that proliferating T-cells were not differentiated towards a regulatory phenotype. Our results support that direct allorecognition may be mediated by RPTECs even in the absence of donor-derived professional APCs. Also, ischemia-reperfusion injury of the graft may enhance the above capacity of RPTECs, increasing the possibility of acute rejection.     

Unsupervised Segmentation of Stereoscopic Video Objects: Constrained Segmentation Fusion Versus Greedy Active Contours

In this paper, we present a novel memory access reduction scheme (MARS) for two-dimension fast cosine transform (2-D FCT). It targets programmable DSPs with high memory-access latency. It reduces the number of memory accesses by: 1) reducing the number of weighting factors and 2) combining butterflies in vector-radix 2-D FCT pruning diagram from two stages to one stage with an efficient structure. Hardware platform based on general purpose processor is used to verify the effectiveness of the proposed method for vector-radix 2-D FCT pruning implementation. Experimental results validate the benefits of the proposed method with reduced memory access, less clock cycle and fewer memory space compared with the conventional implementation.     

Disparity field and depth map coding for multiview 3D image generation

In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods.     

A Scheduling Technique Wireless Personal for Bandwidth Communication Allocation in Networks

Future generation wireless personalcommunication networks (PCN) are expected to providemultimedia capable wireless extensions of fixedATM/B-ISDN. This paper presents a scheduling techniquefor PCN based on TDMA and the leaky bucket regulator, thewell known bandwidth enforcement mechanism for fixedATM. The main objective of the proposed technique is toensure fair and efficient treatment of various types oftraffic on the air interface, includingconstant-bit-rate (CBR) voice and variable-bit-rate(VBR) video. Two alternative priority mechanisms areintroduced and their performance is evaluated. Theperformance comparison of the alternatives reveals aninteresting tradeoff between fairness and quality ofservice (QoS).     

Microstructural changes accompanying repair welding in 5xxx aluminium alloys and their effect on the mechanical properties

At the shipyards, the aluminium alloy 5083 is welded with a multi-pass sequence using the metal inert gas technique. If, while checking the weld integrity either after welding or during service, defects are detected in the vicinity of the weldment, repairs are usually employed to extend the service life.

The repair method involves removal of the upper passes, depending on the thickness and re-welding under the same conditions.

Purpose of this paper is to examine the microstructural changes accompanying repair welding, define their effect on properties of primary importance and set, if possible, an upper limit as far as the number of repairs is concerned.     

Integrating mental health services within primary care. A Canadian program

The increasingly prominent role of the family physician in delivering mental health care can be enhanced if productive and collaborative relationships can be established with local mental health services. This paper describes a Canadian program that has achieved this by bringing mental health counselors and psychiatrists into the offices of 87 family physicians in 35 practices in a community in Southern Ontario. The paper describes the program, the activities of counselors and psychiatrists within the practices, and the administrative structures set up to coordinate these activities. Data is presented from the evaluation of the first year of the program's operation (13 practices and 45 family physicians) during which time 3085 referrals were received. The program made mental health care more available and accessible, increased continuity of care, provided additional support for the family physician, offered new opportunities for continuing education, and led to a reduced and more efficient use of other mental health services. The components of the program can be adapted to most communities.     

Dynamic response and safety assessment of a batch process on cooling breakdown

Cooling breakdown in highly exothermic reaction processes may lead to runaway. The sensitivity and the safety assessment of a batch process on cooling breakdown are studied. The dependence of the minimum cooling time and the maximum allowable time of cooling breakdown for safe operation on the process parameters is investigated.     

SQL extension for spatio-temporal data

An SQL extension is formalized for the management of spatio-temporal data, i.e. of spatial data that evolves with respect to time. The extension is dedicated to applications such as topography, cartography, and cadastral systems, hence it considers discrete changes both in space and in time. It is based on the rigid formalization of data types and of SQL constructs. Data types are defined in terms of time and spatial quanta. The SQL constructs are defined in terms of a kernel of few relational algebra operations, composed of the well-known operations of the 1NF model and of two more, Unfold and Fold. In conjunction with previous work, it enables the uniform management of 1NF structures that may contain not only spatio-temporal but also either purely temporal or purely spatial or conventional data. The syntax and semantics of the extension is fully consistent with the {SQL:2003} standard.     

Coherency strains in compositionally modulated systems and superlattices: spinodal decomposition and magnetoelasticity

Systems with a coherently modulated composition are considered with regard to their elastic properties. The (stress-free) coherency strains are considered in a new frame where the standard state is redefined on the basis of the property under study. These strains are used in the study of the thermodynamics of spinodal decomposition in solids with a (generally) anisotropic distortion into a cubic matrix. Finally, the influence of these strains is considered in the study of magnetostrictive effects in such modulated systems or strained-layer superlattices.