135 research outputs found

    Multiscale expansion of the lattice potential KdV equation on functions of infinite slow-varyness order

    Full text link
    We present a discrete multiscale expansion of the lattice potential Korteweg-de Vries (lpKdV) equation on functions of infinite order of slow-varyness. To do so we introduce a formal expansion of the shift operator on many lattices holding at all orders. The lowest secularity condition from the expansion of the lpKdV equation gives a nonlinear lattice equation, depending on shifts of all orders, of the form of the nonlinear Schr\"odinger (NLS) equationComment: 9 pages, submitted to Journ. Phys.

    The SUPERMAN protein is an active repressor whose carboxy-terminal repression domain is required for the development of normal flowers

    Get PDF
    AbstractSUPERMAN was identified as a putative regulator of transcription that acts in floral development, but its function remains to be clarified. We demonstrate here that SUPERMAN is an active repressor whose repression domain is located in the carboxy-terminal region. Ectopic expression of SUPERMAN that lacked the repression domain resulted in a phenotype similar to that of superman mutants, demonstrating that the repression activity of SUPERMAN is essential for the development of normal flowers. Constitutive expression of SUPERMAN resulted in a severe dwarfism but did not affect cell size, indicating that SUPERMAN might regulate genes that are involved in cell division

    Complete maturation of the plastid protein translocation channel requires a type I signal peptidase

    Get PDF
    The protein translocation channel at the plastid outer envelope membrane, Toc75, is essential for the viability of plants from the embryonic stage. It is encoded in the nucleus and is synthesized with a bipartite transit peptide that is cleaved during maturation. Despite its important function, the molecular mechanism and the biological significance of the full maturation of Toc75 remain unclear. In this study, we show that a type I signal peptidase (SPase I) is responsible for this process. First, we demonstrate that a bacterial SPase I converted Toc75 precursor to its mature form in vitro. Next, we show that disruption of a gene encoding plastidic SPase I (Plsp1) resulted in the accumulation of immature forms of Toc75, severe reduction of plastid internal membrane development, and a seedling lethal phenotype. These phenotypes were rescued by the overexpression of Plsp1 complementary DNA. Plsp1 appeared to be targeted both to the envelope and to the thylakoidal membranes; thus, it may have multiple functions

    Association between Optic Nerve Head Microcirculation and Macular Ganglion Cell Complex Thickness in Eyes with Untreated Normal Tension Glaucoma and a Hemifield Defect

    Get PDF
    Purpose. We evaluated the association between optic nerve head (ONH) microcirculation and macular ganglion cell complex (mGCC) thickness in patients with untreated normal tension glaucoma (NTG) and a hemifield defect. Methods. The medical records of 47 patients with untreated NTG were retrospectively reviewed. Laser speckle flowgraphy was used to obtain mean blur rate (MBR), a relative measure of blood flow. Average total deviation (TD), mGCC, and the circumpapillary retinal nerve fiber layer (cpRNFL) thickness were also analyzed. Results. All parameters corresponding to the defective hemifield were significantly lower than those corresponding to the normal hemifield. In the defective hemifield, MBR was correlated with TD, mGCC, and cpRNFL thickness. In the normal hemifield, MBR was only correlated with mGCC thickness, and multiple regression analysis showed that mGCC thickness was a significant contributing factor of the MBR. Conclusion. MBR was well correlated with mGCC thickness in eyes with untreated NTG and a hemifield defect. In the normal hemifield, mGCC thickness was a contributing factor of the MBR indicating that ONH circulatory dysfunction may be associated with retinal structural changes in the early stages of glaucoma. A reduction in ONH microcirculation may be an early indicator of the presence and progression of glaucoma

    Adenosquamous Carcinoma of the Choledochus

    Get PDF
    The patient was an 86-year-old man who was admitted with obstructive jaundice. Computed tomography revealed a tumor in the hilar choledochus with peripheral hepatic duct dilatation. Endoscopic cholangiography (ERC) demonstrated the defect in the choledochus. Brushing cytology during ERC showed Orange-G-philic keratinized atypical cells, which led to a diagnosis of squamous cell carcinoma. Chemotherapy with tegafur-gimeracil-oteracil potassium was ineffective and was discontinued due to adverse effects. The patient died 5 months after the diagnosis and autopsy revealed tubular adenocarcinoma of the hilar bile duct with squamous cell carcinoma component. Progression of the disease might influence the distribution of adenosquamous carcinoma. The clinicopathological sequence of adenosquamous carcinoma of the choledochus was documented

    Characterization of autonomous Dart1 transposons belonging to the hAT superfamily in rice

    Get PDF
    An endogenous 0.6-kb rice DNA transposon, nDart1-0, was found as an active nonautonomous element in a mutable virescent line, pyl-v, displaying leaf variegations. Here, we demonstrated that the active autonomous element aDart in pyl-v corresponds to Dart1-27 on chromosome 6 in Nipponbare, which carries no active aDart elements, and that aDart and Dart1-27 are identical in their sequences and chromosomal locations, indicating that Dart1-27 is epigenetically silenced in Nipponbare. The identification of aDart in pyl-v was first performed by map-based cloning and by detection of the accumulated transposase transcripts. Subsequently, various transposition activities of the cloned Dart1-27 element from Nipponbare were demonstrated in Arabidopsis. Dart1-27 in Arabidopsis was able to excise nDart1-0 and Dart1-27 from cloned sites, generating footprints, and to integrate into new sites, generating 8-bp target site duplications. In addition to Dart1-27, Nipponbare contains 37 putative autonomous Dart1 elements because their putative transposase genes carry no apparent nonsense or frameshift mutations. Of these, at least four elements were shown to become active aDart elements in transgenic Arabidopsis plants, even though considerable sequence divergence arose among their transposases. Thus, these four Dart1 elements and Dart1-27 in Nipponbare must be potential autonomous elements silenced epigenetically. The regulatory and evolutionary implications of the autonomous Dart1 elements and the development of an efficient transposon-tagging system in rice are discussed

    Distribution of a Knockdown Resistance Mutation (L1014S) in Anopheles gambiae s.s. and Anopheles arabiensis in Western and Southern Kenya

    Get PDF
    In Kenya, insecticide-treated mosquito nets (ITNs) distributed to pregnant women and children under 5 years old through various programs have resulted in a significant reduction in malaria deaths. All of the World Health Organization-recommended insecticides for mosquito nets are pyrethroids, and vector mosquito resistance to these insecticides is one of the major obstacles to an effective malaria control program. Anopheles gambiae s.s. and Anopheles arabiensis are major malaria vectors that are widely distributed in Kenya. Two point mutations in the voltage-gated sodium channel (L1014F and L1014S) are associated with knockdown resistance (kdr) to DDT and pyrethroids in An. gambiae s.s. While the same point mutations have been reported to be rare in An. arabiensis, some evidence of metabolic resistance has been reported in this species. In order to determine the distribution of the point mutation L1014S in An. gambiae s.s. and An. arabiensis in southern and western Kenya, we collected larvae and screened for the mutation by DNA sequencing. We found high allelic and homozygous frequencies of the L1014S mutation in An. gambiae s.s. The L1014S mutation was also widely distributed in An. arabiensis, although the allelic frequency was lower than in An. gambiae s.s. The same intron sequence (length: 57 base) found in both species indicated that the mutation was introgressed by hybridization. The allelic frequency of L1014S was higher in both species in western regions, demonstrating the strong selection pressure imposed by long-lasting insecticide-treated nets (LLITN)/ITN on the An. gambiae s.s. and An. arabiensis populations in those areas. The present contribution of the L1014S mutation to pyrethroid resistance in An. arabiensis may be negligible. However, the homozygous frequency could increase with continuing selection pressure due to expanded LLITN coverage in the future
    • …
    corecore