Search results for "Homology"
showing 10 items of 770 documents
Helicoid and Architectural application
2012
Questo articolo è un risultato parziale di una ricerca riguardante la rappresentazione di superfici complesse in geometria descrittiva. La padronanza e l’abilità nell’uso delle diverse tecniche di rappresentazione, consente di raggiungere risultati che altrimenti non sarebbero perseguibili. La Scuola di Disegno di Ingegneria, dell’Università di Palermo si è da sempre fatta promotrice della scienza della rappresentazione attraverso la sperimentazione di tecniche semplificative ed innovative della geometria descrittiva applicata all’architettura e all’ingegneria. In particolar modo, in questo lavoro, si riporta lo studio di una superficie complessa quale è l’elicoide che trova larga applicazi…
Iron Induces Proliferation and Morphogenesis in Primmorphs from the Marine SpongeSuberites domuncula
2002
Dissociated cells from marine demosponges retain their proliferation capacity if they are allowed to form special aggregates, the primmorphs. On the basis of incorporation studies and septin gene expression, we show that Fe3+ ions are required for the proliferation of cells in primmorphs from Suberites domuncula. In parallel, Fe3+ induced the expression of ferritin and strongly stimulated the synthesis of spicules. This result is supported by the finding that the enzymatic activity of silicatein, converting organosilicon to silicic acid, depends on Fe3+. Moreover, the expression of a scavenger receptor molecule, possibly involved in the morphology of spicules, depends on the presence of Fe3…
The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster
1998
Many of the O2-responsive gene regulators of bacteria are members of the fumarate nitrate reductase-cyclic AMP receptor protein family of transcriptional regulators (12, 13, 15, 17) with predicted structures similar to those of the cyclic AMP receptor protein (11). The Fnr (stands for fumarate nitrate reductase regulator) protein from Escherichia coli (FnrEc) controls the expression of a variety of genes, mainly of anaerobic respiration and metabolism (5, 13). It contains a N-terminal cluster of three essential cysteine residues which are supposed to bind together with Cys122 a [4Fe 4S]2+ cluster which is required for O2 sensing (4, 7, 8, 10, 16). A wide variety of gram-negative bacteria co…
La flessibilità dell’organizzazione biologica. Strutture e funzioni alla luce di un modello gerarchico e pluralista dell’omologia
2016
Ciò che si intende mettere in evidenza nel presente saggio è come l’assunzione di un paradigma gerarchico dell’organizzazione biologica consentirebbe di fornire una nuova formulazione del concetto di omologia e conseguentemente dell’unità dell’evoluzione. Si vedrà, infatti, come i concetti di omologia, analogia, omoplasia, convergenza e parallelismo possano essere considerati al di fuori delle opposizioni omologia vs. analogia, omogenia vs. omoplasia, parallelismo vs. convergenza. Piuttosto tali concetti si riferiscono a piani e livelli biologici che sono diversi, ma in relazione l’uno con l’altro nel mondo complesso dell’evoluzione, poichè il mondo biologico è esso stesso gerarchico, ossia…
Genome-Wide Inhibition of Pro-atherogenic Gene Expression by Multi-STAT Targeting Compounds as a Novel Treatment Strategy of CVDs.
2018
Cardiovascular diseases (CVDs), including atherosclerosis, are globally the leading cause of death. Key factors contributing to onset and progression of atherosclerosis include the pro-inflammatory cytokines Interferon (IFN)a and IFN? and the Pattern Recognition Receptor (PRR) Toll-like receptor 4 (TLR4). Together, they trigger activation of Signal Transducer and Activator of Transcription (STAT)s. Searches for compounds targeting the pTyr-SH2 interaction area of STAT3, yielded many small molecules, including STATTIC and STX-0119. However, many of these inhibitors do not seem STAT3-specific. We hypothesized that multi-STAT-inhibitors that simultaneously block STAT1, STAT2, and STAT3 activit…
Compositional Homology and Creative Thinking
2015
The concept of homology is the most solid theoretical basis elaborated by the morphological thinking during its history. The enucleation of some general criteria for the interpretation of homology is today a fundamental tool for life sciences, and for restoring their own opening to the question of qualitative innovation that arose so powerfully in the original Darwinian project. The aim of this paper is to verify the possible uses of the concept of compositional homology in order to provide of an adequate understanding of the dynamics of creative thinking.
Analogia e omologia: la questione della filogenesi delle emozioni
2013
Aim of this paper is to outline a new evolutionary interpretation of aesthetic emotions, in the light of the most recent developments in Evolutionary Biology, in particular the so-called “Extended Synthesis of Evolution” (Pigliucci-Müller 2010). Focussing on the biological concept of homology, the Author argues that, in order to effectively understand role and evolutionary value of aesthetic emotions, it should be asked not “what aesthetic emotions are for?”, rather “what kind of constraints and homologies influence the specific “shape” of human aesthetic emotions?”. In a few words, we should move from a functionalist approach to human aesthetic emotions towards a morphological one.
Voisinages tubulaires épointés et homotopie stable à l'infini
2022
We initiate a study of punctured tubular neighborhoods and homotopy theory at infinity in motivic settings. We use the six functors formalism to give an intrinsic definition of the stable motivic homotopy type at infinity of an algebraic variety. Our main computational tools include cdh-descent for normal crossing divisors, Euler classes, Gysin maps, and homotopy purity. Under-adic realization, the motive at infinity recovers a formula for vanishing cycles due to Rapoport-Zink; similar results hold for Steenbrink's limiting Hodge structures and Wildeshaus' boundary motives. Under the topological Betti realization, the stable motivic homotopy type at infinity of an algebraic variety recovers…
Molecular cloning and characterization of the complementary DNA coding for the B-chain of murine Clq
1989
AbstractcDNA clones coding for the B-chain of murine Clq were isolated from a mouse macrophage library. The characterized clones include the total coding region plus a leader sequence. High homology was found with human Clq B-chain in the coding region (81%). Northern blot analysis of total RNA from different tissues of Balb/c mice showed one band of approximately 1.2 kb. The highest signal was found in RNA preparations of thioglycolate-activated peritoneal macrophages. The probe also hybridized with mRNA from spleen, thymus and heart. Extremely weak signals were found in liver, kidney, lung and intestine tissues.
Differential VASP phosphorylation controls remodeling of the actin cytoskeleton
2009
Proteins of the Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) family link signal transduction pathways to actin cytoskeleton dynamics. VASP is substrate of cAMP-dependent, cGMP-dependent and AMP-activated protein kinases that primarily phosphorylate the sites S157, S239 and T278, respectively. Here, we systematically analyzed functions of VASP phosphorylation patterns for actin assembly and subcellular targeting in vivo and compared the phosphorylation effects of Ena/VASP family members. Methods used were the reconstitution of VASP-null cells with `locked' phosphomimetic VASP mutants, actin polymerization of VASP mutants in vitro and in living cells, site-specific kinase-mediated…