Cytokinesis terminates mitosis, resulting in separation of the two sister cells. Septins, a conserved family of GTP-binding cytoskeletal proteins, are an absolute requirement for cytokinesis in budding yeast. We demonstrate that septin-dependence of mammalian cytokinesis differs greatly between cell types: genetic loss of the pivotal septin subunit SEPT7 in vivo reveals that septins are indispensable for cytokinesis in fibroblasts, but expendable in cells of the hematopoietic system. SEPT7-deficient mouse embryos fail to gastrulate, and septin-deficient fibroblasts exhibit pleiotropic defects in the major cytokinetic machinery, including hyperacetylation/stabilization of microtubules and stalled midbody abscission, leading to constitutive multinucleation. We identified the microtubule depolymerizing protein stathmin as a key molecule aiding in septin-independent cytokinesis, demonstrated that stathmin supplementation is sufficient to override cytokinesis failure in SEPT7-null fibroblasts, and that knockdown of stathmin makes proliferation of a hematopoietic cell line sensitive to the septin inhibitor forchlorfenuron. Identification of septin-independent cytokinesis in the hematopoietic system could serve as a key to identify solid tumor-specific molecular targets for inhibition of cell proliferation.

Abstract-The intent of this paper is to explore the application of information obtained from fully polarimetric data for land cover classification. Various land cover classification techniques are available in the literature, but still uncertainty exists in labeling various clusters to their own classes without using any a priori information. Therefore, the present work is focused on analyzing useful intrinsic information extracted from SAR observables obtained by various decomposition techniques. The eigenvalue decomposition and Pauli decomposition have been carried out to separate classes on the basis of their scattering mechanisms. The various classification techniques (supervised: minimum distance, maximum likelihood, parallelepiped and unsupervised: Wishart) were applied in order to see possible differences among SAR observables in terms of information that they contain and their usefulness in classifying particular land cover type. Another important issue is labeling the clusters, and this work is carried out by decision tree classification that uses knowledge based approach. This classifier is implemented by scrupulous knowledge of data obtained by empirical evidence and their experimental validation. It has been demonstrated quantitatively that standard polarimetric parameters such as polarized backscatter coefficients (linear, circular 48Mishra, Singh, and Yamaguchi and linear 45 • ), co and cross-pol ratios for both linear and circular polarizations can be used as information bearing features for making decision boundaries. This forms the basis of discrimination between various classes in sequential format. The classification approach has been evaluated for fully polarimetric ALOS PALSAR L-band level 1.1 data. The classifier uses these data to classify individual pixel into one of the five categories: water, tall vegetation, short vegetation, urban and bare soil surface. The quantitative results shown by this classifier give classification accuracy of about 86%, which is better than other classification techniques.

Deficiency of transplant recipients for the chemokine receptor CCR7 was originally described to slightly increase the survival time of vascularized solid organ grafts, probably due to a reduced priming of alloreactive T cells. Using a model of allotolerance induction by donorspecific splenocyte transfusion (DST) in combination with anti-CD40L mAb-mediated costimulation blockade (CSB), we show here a striking failure of CCR7-deficient (CCR7 À/À ) recipients to tolerate cardiac allografts. Furthermore, in addition to the recently described lack of Treg, CCR7À/À mice were found to harbor significantly reduced numbers of plasmacytoid dendritic cells (pDCs) within peripheral as well as mesenteric lymph nodes (LNs), but not the bone marrow or spleen. pDCs had previously been suggested to function as tolerogenic APC during allograft transplantation, and a single transfer of syngeneic WT pDCs, but not conventional DCs, was indeed sufficient to rescue graft survival in DST1CSB-treated CCR7 À/À recipients in a dose-dependent manner. We therefore conclude that the nearly complete absence of pDCs within LNs of CCR7 À/À mice prevents the successful induction of DST1CSB-mediated allotolerance, leading to the observed acute rejection of cardiac allografts under tolerizing conditions.

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