Pummerer-type Functionalization of Aryl and Alkenyl Selenoxides

Heteroatom-stabilized carbenium ions have been widely recognized as potential electrophilic reagents. However, in contrast with the extensive works on thionium ion series, the highly labile character of selenoxide functionalities has caused serious limitation in the synthetic use in spite of their wide potentiality as synthetic equivalents of electrophilic selonium ions. In this paper, novel generation of selonium ions and the synthetic uses of the species for Pummerer-type α-functionalization and for cycloaddition by using the novel dienophilic behavior of π-conjugated selonium cations.     

Thyrotrophin in the pars tuberalis triggers photoperiodic response

Molecular mechanisms regulating animal seasonal breeding in response to changing photoperiod are not well understood. Rapid induction of gene expression of thyroid-hormone-activating enzyme (type 2 deiodinase, DIO2) in the mediobasal hypothalamus (MBH) of the Japanese quail (Coturnix japonica) is the earliest event yet recorded in the photoperiodic signal transduction pathway. Here we show cascades of gene expression in the quail MBH associated with the initiation of photoinduced secretion of luteinizing hormone. We identified two waves of gene expression. The first was initiated about 14 h after dawn of the first long day and included increased thyrotrophin (TSH) beta-subunit expression in the pars tuberalis; the second occurred approximately 4 h later and included increased expression of DIO2. Intracerebroventricular (ICV) administration of TSH to short-day quail stimulated gonadal growth and expression of DIO2 which was shown to be mediated through a TSH receptor-cyclic AMP (cAMP) signalling pathway. Increased TSH in the pars tuberalis therefore seems to trigger long-day photoinduced seasonal breeding.     

Frequent pathway mutations of splicing machinery in myelodysplasia

Myelodysplastic syndromes and related disorders (myelodysplasia) are a heterogeneous group of myeloid neoplasms showing deregulated blood cell production with evidence of myeloid dysplasia and a predisposition to acute myeloid leukaemia, whose pathogenesis is only incompletely understood. Here we report whole-exome sequencing of 29 myelodysplasia specimens, which unexpectedly revealed novel pathway mutations involving multiple components of the RNA splicing machinery, including U2AF35, ZRSR2, SRSF2 and SF3B1. In a large series analysis, these splicing pathway mutations were frequent (～45 to ～85%) in, and highly specific to, myeloid neoplasms showing features of myelodysplasia. Conspicuously, most of the mutations, which occurred in a mutually exclusive manner, affected genes involved in the 3'-splice site recognition during pre-mRNA processing, inducing abnormal RNA splicing and compromised haematopoiesis. Our results provide the first evidence indicating that genetic alterations of the major splicing components could be involved in human pathogenesis, also implicating a novel therapeutic possibility for myelodysplasia.     

Cblb is a major susceptibility gene for rat type 1 diabetes mellitus

The autoimmune disease type 1 diabetes mellitus (insulin-dependent diabetes mellitus, IDDM) has a multifactorial etiology. So far, the major histocompatibility complex (MHC) is the only major susceptibility locus that has been identified for this disease and its animal models. The Komeda diabetes-prone (KDP) rat is a spontaneous animal model of human type 1 diabetes in which the major susceptibility locus Iddm/kdp1 accounts, in combination with MHC, for most of the genetic predisposition to diabetes. Here we report the positional cloning of Iddm/kdp1 and identify a nonsense mutation in Cblb, a member of the Cbl/Sli family of ubiquitin-protein ligases. Lymphocytes of the KDP rat infiltrate into pancreatic islets and several tissues including thyroid gland and kidney, indicating autoimmunity. Similar findings in Cblb-deficient mice are caused by enhanced T-cell activation. Transgenic complementation with wildtype Cblb significantly suppresses development of the KDP phenotype. Thus, Cblb functions as a negative regulator of autoimmunity and Cblb is a major susceptibility gene for type 1 diabetes in the rat. Impairment of the Cblb signaling pathway may contribute to human autoimmune diseases, including type 1 diabetes.     

Mobilization of a transposon in the rice genome

Rice (Oryza sativa L.) is an important crop worldwide and, with the availability of the draft sequence, a useful model for analysing the genome structure of grasses. To practice efficient rice breeding through genetic engineering techniques, it is important to identify the economically important genes in this crop. The use of mobile transposons as gene tags in intact plants is a powerful tool for functional analysis because transposon insertions often inactivate genes. Here we identify an active rice transposon named miniature Ping (mPing) through analysis of the mutability of a slender mutation of the glume-the seed structure that encloses and determines the shape of the grain. The mPing transposon is inserted in the slender glume (slg) mutant allele but not in the wild-type allele. Search of the O. sativa variety Nipponbare genome identified 34 sequences with high nucleotide similarity to mPing, indicating that mPing constitutes a family of transposon elements. Excision of mPing from slg plants results in reversion to a wild-type phenotype. The mobility of the transposon mPing in intact rice plants represents a useful alternative tool for the functional analysis of rice genes.     

Shadow free texture acquisition of a large scale scene for city modeling

Texture acquisition of a large scale scene is one of the critical research areas in computer vision and can be used in other application areas such as computer graphics (CG), the intelligent transportation system (ITS) and the 3D geographic information system (GIS). Moreover, to acquire texture without noise (e. g. , a shadow, an obstacle body) is vital for such work. Although obstacles can be removed by using 3D geometric data, shadow elimination is still a difficult problem and strongly required for the CG and ITS community, especially for city modeling and simulation purposes. In this paper, we propose an automatic multiple image fusion technique and an efficient and simple shadow removing technique to retrieve high quality texture images of an urban area. The image fusion can be efficiently achieved by epipolar plane image (EPI) analysis, and the shadow elimination can be successfully carried out by an illumination-independent color clustering technique. The strength of this algorithm is that we can successfully fuse multiple images and eliminate shadows from the fused single image, especially in low dynamic range images, which have proven difficult using previous techniques.     

Nearest neighbor search algorithm for GBD tree spatial data structure

This paper describes the nearest neighbor (NN) search algorithm on the GBD(generalized BD) tree. The GBD tree is a spatial data structure suitable for two-or three-dimensional data and has good performance characteristics with respect to the dynamic data environment. On GIS and CAD systems, the R-tree and its successors have been used. In addition, the NN search algorithm is also proposed in an attempt to obtain good performance from the R-tree. On the other hand, the GBD tree is superior to the R-tree with respect to exact match retrieval, because the GBD tree has auxiliary data that uniquely determines the position of the object in the structure. The proposed NN search algorithm depends on the property of the GBD tree described above. The NN search algorithm on the GBD tree was studied and the performance thereof was evaluated through experiments.