486 research outputs found
A comparison of Landau-Ginzburg models for odd-dimensional Quadrics
In [Rie08], the second author defined a Landau-Ginzburg model for homogeneous spaces G/P, as a regular function on an affine subvariety of the Langlands dual group. In this paper, we reformulate this LG model (X^, W_t) in the case of the odd-dimensional quadric, as a rational function on a Langlands dual projective space, in the spirit of work by R. Marsh and the second author for type A Grassmannians and by both authors for Lagrangian Grassmannians. We also compare this LG model with the one obtained independently by Gorbounov and Smirnov, and we use this comparison to deduce part of a conjecture of the second author for odd-dimensional quadrics
Kentaro Sasaki : Physical education teacher belonged to Kinan-Sakkyou : His joining in Kinan・Sakkyou
Kentaro Sasaki, the author of "Taiiku-no-ko" had made many famous P.E.practices as a teacher of junior high school and high school at Kinan district since the end of the World War2.The features of his practices are ; 1) using compositions as educational method, 2) combining with educational guidance, 3) starting from reality of children's bodies and minds, and so on. This study attempts to clarify the process of his joining in Kinan-Sakkyou and the way to use compositions to practices anal- yzing his articles and "Kinan Kyoiku" which were bulletins of Kinan-Sakkyou
Genecialist manifesto: overcoming the “class struggle” in medicine
Kentaro Iwata Division of Infectious Diseases, Kobe University Hospital, Kobe, Hyogo, Japan Abstract: Generalists and specialists are often considered two completely distinct species, which culminates in the establishment of a concept of dichotomy. However, these dichotomy can at times fuel tension and even erupt into open conflict. In order to resolve this issue, the author herein proposes the concept of a “genecialist.” The genecialist refers to a hybrid comprising elements inherent to both generalists and specialists. This potentially overcomes the multitude of issues associated with both generalists and specialists in the practical aspects of medicine. The coalescence of these two contrarieties may hold the key to improving the future of health care. Mediating and integrating both categories into one consolidated entity carries the potential to stem the tide of class warfare between generalists and specialists. Keywords: genecialist, aufheben, generalist, specialist, asymmetr
Ceramide Transport from the Endoplasmic Reticulum to the Trans Golgi Region at Organelle Membrane Contact Sites
Lipid transfer proteins rectify inter-organelle flux and accurately deliver lipids at membrane contact sites
Organelle contacts: Sub‐organelle zones to facilitate rapid and accurate inter‐organelle trafficking of lipids
Sphingolipid synthesis and scavenging in the intracellular apicomplexan parasite, Toxoplasma gondii
Sphingolipids are essential components of eukaryotic cell membranes, particularly the plasma membrane, and are involved in a diverse array of signal transduction pathways. Mammals produce sphingomyelin (SM) as the primary complex sphingolipid via the well characterised SM synthase. In contrast yeast, plants and some protozoa utilise an evolutionarily related inositol phosphorylceramide (IPC) synthase to synthesise IPC. This activity has no mammalian equivalent and IPC synthase has been proposed as a target for anti-fungals and anti-protozoals. However, detailed knowledge of the sphingolipid biosynthetic pathway of the apicomplexan protozoan parasites was lacking. In this study bioinformatic analyses indicated a single copy orthologue of the putative SM synthase from the apicomplexan Plasmodium falciparum (the causative agent of malaria) was a bona fide sphingolipid synthase in the related model parasite, Toxoplasma gondii (TgSLS). Subsequently, TgSLS was indicated, by complementation of a mutant cell line, to be a functional orthologue of the yeast IPC synthase (AUR1p), demonstrating resistance to the well characterised AUR1p inhibitor aureobasidin A. In vitro, recombinant TgSLS exhibited IPC synthase activity and, for the first time, the presence of IPC was demonstrated in T. gondii lipid extracts by mass spectrometry. Furthermore, host sphingolipid biosynthesis was indicated to influence, but be non-essential for, T. gondii proliferation, suggesting that whilst scavenging does take place de novo sphingolipid synthesis may be important for parasitism
Establishment of HeLa cell mutants deficient in sphingolipid-related genes using TALENs.
Sphingolipids are essential components in eukaryotes and have various cellular functions. Recent developments in genome-editing technologies have facilitated gene disruption in various organisms and cell lines. We here show the disruption of various sphingolipid metabolic genes in human cervical carcinoma HeLa cells by using transcription activator-like effector nucleases (TALENs). A TALEN pair targeting the human CERT gene (alternative name COL4A3BP) encoding a ceramide transport protein induced a loss-of-function phenotype in more than 60% of HeLa cells even though the cell line has a pseudo-triploid karyotype. We have isolated several loss-of-function mutant clones for CERT, UGCG (encoding glucosylceramide synthase), and B4GalT5 (encoding the major lactosylceramide synthase), and also a CERT/UGCG double-deficient clone. Characterization of these clones supported previous proposals that CERT primarily contributes to the synthesis of SM but not GlcCer, and that B4GalT5 is the major LacCer synthase. These newly established sphingolipid-deficient HeLa cell mutants together with our previously established stable transfectants provide a 'sphingolipid-modified HeLa cell panel,' which will be useful to elucidate the functions of various sphingolipid species against essentially the same genomic background
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