Search results for "Stone"
showing 10 items of 1137 documents
Metals distributions within black crusts sampled on the facade of an historical monument: The case study of the Cathedral of Monza (Milan, Italy)
2019
This research deals with the characterization of black crusts collected from Dome of Monza. Black crusts (BC) can be formed as a result of different chemical and physical reactions between the stone surface and environmental factors (such as gaseous pollutants, aerosol particulate matter and its specific chemical constituents-the carbonaceous fraction and the metals); therefore, they are considered as a passive sampler of pollutants. The specific focus of the current work is the study of the metals and their distribution within the samples. To characterize BC, several techniques were used such as: HRSEM-EDX, IC and LA-ICP/MS. This integrated approach allowed us to gain information about the…
Bird assemblages in isolated Ficus trees in Kenyan farmland
2006
Over the last few decades a rapid and extensive conversion of tropical forests to agricultural land has taken place resulting in mosaics of fragmented forest patches, pastures and farmland. While the effects of forest fragmentation on biodiversity have been intensively studied within the remaining forests, relatively little is known about the biodiversity in tropical farmland (Daily et al. 2001, Pimentel et al. 1992). Frugivorous birds are an important group of species in tropical farmland ecosystems. Frugivorous birds are significant seed dispersers and can play a prominent role in transporting seeds into disturbed areas and setting the stage for the regeneration of these systems. Isolated…
Cenomanian rudist-dominated shelf-margin limestones from the Panormide carbonate platform (Sicily, Italy): facies analysis and sequence stratigraphy
2000
Sedimentological, paleontological and sequence analyses of Cenomanian limestones in Sicily reveal thc facies architecture and dynamics of a Mid Cretaceous rudistdominated platform margin from Western Tethys. The studied deposits outcrop near Palermo, as part of a large structural unit of the Sicilian Maghrebids. They belong to the Panormide carbonate platform, a Mesocenozoic paleogeographic domain of the African margin. The lateral continuity of the beds along three nearly parallel E-W outcrop sections allowed the recording of cm/dm thick lithological and faunal variations. Nine main lithofacies associations have been recognised along about 200 m of subvertical strata. Their vertical and la…
Purification by affinity chromatography of H1 RNA-Binding Proteins from rat brain
2003
Post-transcriptional regulation of mRNA metabolism is involved in processes as different as cell fate specification in development and cell response to a large variety of environmental cues. Regulation of all steps of RNA metabolism depends on RNA-binding proteins (RBPs). By using a T1 RNase protection assay, we previously identified three H1° RNA-binding factors (p40, p70 and p110), highly expressed in the rat brain. Here we report enrichment of these factors from brain extracts, obtained by affinity chromatography of biotinylated H1° RNA-protein complexes on streptavidin-conjugated paramagnetic particles. The purified proteins maintain RNA-binding ability and preference for histone messag…
Carbocysteine reverses the effects of cigarette smoke and improves the effects of beclomethasone on the histone deacetylases in bronchial epithelial …
2015
Cigarette smoke exposure, increasing oxidative stress, may negatively affect histone deacetylase expression/activity. Histone deacetylase expression/activity and in particular HDAC2, HDAC3, and SIRT-1 may control inflammation, cell senescence and responses to corticosteroids. The effects of carbocysteine and of beclomethasone on the histone deacetylase expression/activity in human bronchial epithelial cells stimulated with cigarette smoke extracts (CSE) are largely unknown. This study was aimed to explore whether carbocysteine and beclomethasone, in a bronchial epithelial cell line (16-HBE) exposed to CSE, were able to modulate the expression/activity of HDAC2, HDAC3, and of SIRT-1. Methods…
The Histone Acetyl-Transferase MOZ Cooperates with the Histone Methyl-Transferase MLL to Regulate HOX Gene Expression in Human Hematopoietic Stem Cel…
2008
Abstract MOZ (MOnocytic leukaemia Zinc finger protein) (also called MYST3 or KAT6A) is a member of the MYST family of HATs which likely acetylate H4K16. The MLL (MixedLineageLeukemia) gene is a frequent target for recurrent chromosomal translocations found in AML and ALL. MLL (KMT2A) is a methyl-transferase targeting H3K4. It was shown that MOZ/CBP leukemia, as observed in MLL-rearranged leukemias, harbors abnormal levels of homeobox (HOX) genes expression. HOX transcription factors have a crucial function in hematopoiesis regulation. In addition, HOXA5, HOXA7, and HOXA9 are often considered to be pivotal HOX genes for MLL transformation, constituting downstream targets of MLL. In our study…
In vivo assembly of chromatin on pBR322 sequences cloned into yeast plasmids
1989
Abstract In order to study the in vivo assembly of chromatin on prokaryotic DNA templates, we have transformed yeast cells with plasmids pAJ50 and pRB58, which contain pBR322 sequences. In both cases nucleosomes are assembled in vivo on pBR322 DNA, although the nucleosomes are not homogeneous in size. To explore whether there is any preference for nucleosome assembly along pBR322 sequences, we have used an indirect end labeling method. The results indicate that most nucleosomes are placed at random on pBR322, although the probability for histone octamers to interact with some short regions is somewhat reduced. These regions coincide with sequences in which the frequency distribution of nucl…
Circulating Histones and Nucleosomes as Biomarkers in Sepsis and Septic Shock
2016
Sepsis, severe sepsis, and septic shock are among the leading causes of death worldwide and their incidence is constantly increasing. Despite early intervention in intensive care units (ICUs) mortality remains high. There is great interest in understanding the genetics and epigenetics of the host in response to infection because of two reasons: the peculiarities of each patient, and the unclear associations identified between genetic polymorphisms and susceptibility to sepsis. In addition, chromatin remodeling and epigenetic changes occur in crucial genes involved in the inflammatory response and also in the immunosuppression found in sepsis. The early and accurate diagnosis of sepsis is a …
En contexte ou hors contexte : lecture des matériaux et lecture du bâti
2020
Le choix des matériaux occupe une place importante dans l’élaboration du projet architectural, et détermine des orientations essentielles pour le chantier, dans la réalisation de celui-ci, son organisation, voire sa progression. Loin de se résumer à un simple descripteur ou accessoire de la stratigraphie du bâtiment, les matériaux de construction sont avant tout le reflet d’une réalité complexe du chantier à la fois matérielle et immatérielle : projet, exigences et capacité financière du commanditaire, réseaux d’échange, environnement sollicité. Leur prise en compte dans l’analyse du bâti transcende la logique stratigraphique, en épaulant celle-ci là où elle fait défaut et en replaçant la r…