104,232 research outputs found
Reduced level of the histone deacetylase Sir2 in mRNA decapping mutants leads to silencing defects and premature aging
No full textRNA metabolism directly or indirectly impacts various cellular pathways.
Mutations in factors involved in mRNA decapping result in phenotypic markers of apoptosis and lead to premature aging. These traits are accompanied by elevated histone mRNA levels persisting throughout the cell cycle and defects in S-phase progression.
Here we show that decapping mutants exhibit low levels of Sir2, which reduces silencing and leads to the elevated transcription of rDNA intergenic spacer regions.
We postulate that defects in decapping are associated with the derepression of silencing at heterochromatic-like regions. This, in turn, may affect histone modification and induce loss of silencing at specific loci, as well as recombination within rDNA repeats, both of which have been shown to regulate cellular lifespan.
References
[1] Mazzoni C, Falcone C. Biochem Soc Trans. (2011), 39(5):1461-5. Review.
[2] Mroczek S & Kufel J (2008).Nucleic Acids Res 36, 2874-2888.
[3]Mazzoni C, Herker E, Palermo V, Jungwirth H, Eisenberg T, Madeo F & Falcone C (2005).EMBO Rep 6, 1076-108.
[4]Palermo V, Cundari E, Mangiapelo E, Falcone C & Mazzoni C (2010).Cell Cycle 9, 3991-3996.
[5] Thompson DM & Parker R (2007).Mol Cell Biol 27, 92-101
Channel Estimation in the Presence of Timing Offsets for MC-CDMA Uplink Transmissions with Combined Equalization
No full textIn this paper we consider the uplink of a multi-carrier code-division multiple-access (MC-CDMA) system employing combined equalization and we address the problem of channel estimation in the presence of residual timing offsets. In particular, we propose a method based on the maximum-likelihood (ML) principle that jointly estimates the pre-equalized channel response and timing offset of each user. The resulting scheme operates in the frequency-domain and exploits some training blocks (carrying known symbols) placed at the beginning of the uplink time-slot. Numerical results are given to highlight the effectiveness of the proposed method and to make comparisons with other existing solutions
"Sogno", "La politica", "Canzonetta" di T. Michaylovskaya, in "Klub N, literaturnyj almanach", Centr poetičeskoj knigi (pri Russkom PEN-centre), Moskva: 2016.
No full textTraduzione di tre brevi racconti di T. G. Michajlovskaj
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
L-arginine metabolism in myeloid cells controls T-lymphocyte functions
No full textAlthough current attention has focused on regulatory T lymphocytes as suppressors of autoimmune responses, powerful immunosuppression is also mediated by a subset of myeloid cells that enter the lymphoid organs and peripheral tissues during times of immune stress. If these myeloid suppressor cells (MSCs) receive signals from activated T lymphocytes in the lymphoid organs, they block T-cell proliferation. MSCs use two enzymes involved in arginine metabolism to control T-cell responses: inducible nitric oxide synthase (NOS2), which generates nitric oxide (NO) and arginase 1 (Arg1), which depletes the milieu of arginine. Th1 cytokines induce NOS2, whereas Th2 cytokines upregulate Arg1. Induction of either enzyme alone results in a reversible block in T-cell proliferation. When both enzymes are induced together, peroxynitrites, generated by NOS2 under conditions of limiting arginine, cause activated T lymphocytes to undergo apoptosis. Thus, NOS2 and Arg1 might act separately or synergistically in vivo to control specific types of T-cell responses, and selective antagonists of these enzymes might prove beneficial in fighting diseases in which T-cell responses are inappropriately suppressed. This Opinion is the second in a series on the regulation of the immune system by metabolic pathways
Synthesis and antiviral activity of quinolone and oxazine derivatives
No full textA new class of synthetic quinonic compounds acting as antiproliferative agents”,. A. Bolognese, T. Di Meo, M. Manfra, G. Correale, O. Mazzoni, E. Novellino, G. Brunetti, L. Sanna, D. Del piano, P. La Colla
Abstract of XVIth International Symposium on Medicinal Chemistry
BOLOGNA
18-22 SETTEMBRE 200
Il rifiuto della sofistica nelle postille tassiane al Mazzoni
No full textIl saggio dà notizia del ritrovamento di un nuovo postillato di T. Tasso, un esemplare della "Difesa di Dante" di Jacopo Mazzoni della Bibl. Nazionale di Napoli; viene ricostruita la ricezione tassiana del volume e vengono infine pubblicate tutte le note accompagnate da un commento.The essay gives news of the discovery of a new annotated T. Rate, a copy of the "" Defense of Dante "" Jacopo Mazzoni's Bibl. Nazionale in Naples, is reconstructed receiving Tasso volume and are also published all the notes accompanied by a commentary
Cerebellum and semantic memory: A TMS study using the DRM paradigm
No full textTraditionally, the cerebellum has been linked to motor functions, but recent evidence suggest that it is also involved in a wide range of cognitive processes. Given the uniformity of cerebellar cortex microstructure, it has been proposed that the same computational process might underlie cerebellar involvement in both motor and cognitive functions. Within motor functions, the cerebellum it is involved in procedural memory and associative learning. Here, we hypothesized that the cerebellum may participate to semantic memory as well. To test whether the cerebellum is causally involved in semantic memory, we carried out two experiments in which participants performed the Deese-Roediger-McDermott paradigm (DRM) while online transcranial magnetic stimulation (TMS) was administered over the right cerebellum or over a control site. In Experiment 1, cerebellar TMS selectively affected participants' discriminability for critical lures without affecting participants’ discriminability for unrelated words and in Experiment 2 we found that the higher was the semantic association between new and studied words, the higher was the memory impairment caused by the TMS. These results indicate that the right cerebellum is causally involved in semantic memory and provide evidence consistent with theories that proposed the existence of a unified cerebellar function within motor and cognitive domains, as well with recent perspectives about cerebellar involvement in semantic memory and predictive functions
The sensory basis for vibrational behaviours: functional morphology and diversity of vibration receptor organs in insect
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