A remark on Leclerc's Frobenius categories

Leclerc recently studied certain Frobenius categories in connection with cluster algebra structures on coordinate rings of intersections of opposite Schubert cells. We show that these categories admit a description as Gorenstein projective modules over an Iwanaga-Gorenstein ring of virtual dimension at most two. This is based on a Morita type result for Frobenius categories.Comment: 5 pages, extended abstract for a talk at the Workshop Homological Bonds between Commutative Algebra and Representation Theory at CRM Barcelona, February 2015, comments welcom

Actin-Related Protein Arp6 Influences H2A.Z-Dependent and -Independent Gene Expression and Links Ribosomal Protein Genes to Nuclear Pores

Actin-related proteins are ubiquitous components of chromatin remodelers and are conserved from yeast to man. We have examined the role of the budding yeast actin-related protein Arp6 in gene expression, both as a component of the SWR1 complex (SWR-C) and in its absence. We mapped Arp6 binding sites along four yeast chromosomes using chromatin immunoprecipitation from wild-type and swr1 deleted (swr1Δ) cells. We find that a majority of Arp6 binding sites coincide with binding sites of Swr1, the catalytic subunit of SWR-C, and with the histone H2A variant Htz1 (H2A.Z) deposited by SWR-C. However, Arp6 binding detected at centromeres, the promoters of ribosomal protein (RP) genes, and some telomeres is independent of Swr1 and Htz1 deposition. Given that RP genes and telomeres both show association with the nuclear periphery, we monitored the ability of Arp6 to mediate the localization of chromatin to nuclear pores. Arp6 binding is sufficient to shift a randomly positioned locus to nuclear periphery, even in a swr1Δ strain. Arp6 is also necessary for the pore association of its targeted RP promoters possibly through cell cycle-dependent factors. Loss of Arp6, but not Htz1, leads to an up-regulation of these RP genes. In contrast, the pore-association of GAL1 correlates with Htz1 deposition, and loss of Arp6 reduces both GAL1 activation and peripheral localization. We conclude that Arp6 functions both together with the nucleosome remodeler Swr1 and also without it, to mediate Htz1-dependent and Htz1-independent binding of chromatin domains to nuclear pores. This association is shown to have modulating effects on gene expression

Data for: Recent advances on the increased performances of methanol carbonylation into acetic acid.

Carbonylation reactions.Catalysis with noble metal

Data for: Recent advances on the increased performances of methanol carbonylation into acetic acid.

Carbonylation reactions.Catalysis with noble metalsTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Hydride route for the palladium-catalysed cyclocarbonylation of monoterpenes

This paper focuses on the mechanism by which a monoterpene undergoes a cyclocarbonylation reaction catalysed by a palladium complex. Evidence is provided, based on intermediate species observed under pressure or with various ligands, that the catalytic cycle follows a hydride route starting from [Pd(H)(SnCl3)L-2], The [Pd(H)(SnCl3)L-2] complexes (L = PPh3 or PCy3) have been observed for the first time by multinuclear NMR spectroscopy. Cationic hydride complexes or palladium(0) precursors show either no or poor reactivity. Studies related to model platinum complex chemistry have detected an acylplatinum species. Most of the observations have been done on the cyclocarbonylation of isopulegol, di-hydromyrcenol or isolimonene into the corresponding lactones or cyclopentanones. The use of dihydromyrcene allowed us to observe the acylplatinum complex and the corresponding elusive acylpalladium species. The co-catalytic role of SnCl2 is also demonstrated

Synergistic lethality between BRCA1 and H3K9me2 loss reflects satellite derepression.

has two histone H3 Lys9 methyltransferases, MET-2 (SETDB1 homolog) and SET-25 (G9a/SUV39H1 related). In worms, we found simple repeat sequences primarily marked by H3K9me2, while transposable elements and silent tissue-specific genes bear H3K9me3. RNA sequencing (RNA-seq) in histone methyltransferase (HMT) mutants shows that MET-2-mediated H3K9me2 is necessary for satellite repeat repression, while SET-25 silences a subset of transposable elements and tissue-specific genes through H3K9me3. A genome-wide synthetic lethality screen showed that RNA processing, nuclear RNA degradation, the BRCA1/BARD1 complex, and factors mediating replication stress survival are necessary for germline viability in worms lacking MET-2 but not SET-25. Unlike mutants, -null worms accumulated satellite repeat transcripts, which form RNA:DNA hybrids on repetitive sequences, additively with the loss of BRCA1 or BARD1. BRCA1/BARD1-mediated H2A ubiquitination and MET-2 deposited H3K9me2 on satellite repeats are partially interdependent, suggesting both that the loss of silencing generates BRCA-recruiting DNA damage and that BRCA1 recruitment by damage helps silence repeats. The artificial induction of MSAT1 transcripts can itself trigger damage-induced germline lethality in a wild-type background, arguing that the synthetic sterility upon BRCA1/BARD1 and H3K9me2 loss is directly linked to the DNA damage provoked by unscheduled satellite repeat transcription

OMCVD on Fluidized Divided Substrates : a Potential Method for the Preparation of Catalysts

The OMCVD method has been used to deposit highly pure metal particles on porous divided substrates in order to prepare metal supported catalysts. A fluidized bed reactor has been especially designed and the requirements of CVD and fluidization have been taken into account to select convenient experimental conditions. Three organometallic compounds of rhodium have been selected and their thermal decomposition under He and He/H2 mixtures studied by infrared spectroscopy and on-line mass spectrometry analyses. The deposition are carried out at a total pressure of 100 Torr and substrate temperatures as low as 100 °C. The solid deposits have been characterized by XPS, the size and dispersion of the particules have been determined by chemisorption methods or measured by TEM. These catalysts can be used without further treatment and their performances have been compared to those of conventionally prepared ones