Search results for "wall"

An Overview of the Hypogene Caves of Sicily

2017

Karst in Sicily develops in both Messinian gypsum and Mesozoic or Tertiary limestone rocks. Caves are also found in the basalts of Mount Etna. Except for some rare cases, until recently most caves developed in limestone were considered to be of epigenetic origin. The discovery of gypsum in some of these caves, and especially detailed morphological studies, have allowed defining a hypogenic origin for a dozen of caves up to now. In some of these, the hypogenic evidences are very clear, while others remain in doubt because of the widespread presence of well-developed condensation-corrosion morphologies not necessarily related to hydrothermal fluids. This paper reports the present knowledge of…

Overexpression of a cell wall enzyme reduces xyloglucan depolymerization and softening of transgenic tomato fruits.

2010

Xyloglucan xyloglucosyltransferase/endohydrolase (XTHs: EC 2.4.1.207 and/or EC 3.2.1.151) has been proposed to have a dual role integrating newly secreted xyloglucan chains into an existing wall-bound xyloglucan and restructuring existing cell wall material by catalyzing transglucosylation between previously wall bound xyloglucan molecules. In this work we generated transgenic tomatoes with altered levels of an XTH gene. These transgenic fruits showed significant overexpression of the XTH proteins in comparison with the wild type. Specific XET activity was approximately 4.33 fold higher in the transgenic fruits compared with the wild type fruits, although in both cases the activity decrease…

Cloning and characterization of the phenylalanyl-tRNA synthetase β subunit gene fromCandida albicans

1998

A Candida albicans expression library was constructed from RNA isolated from regenerating protoplasts. A 1.4-kb cDNA clone was used to isolate a genomic fragment. Sequence analysis revealed an open reading frame of 593 amino acids with an overall identity of 63.6% with the phenylalanyl-tRNA synthetase beta subunit (FRS1) of Saccharomyces cerevisiae. We named it CaFRS1. It is located in a single copy in chromosome R, SfiI fragment M. Its expression showed a decrease during the cell wall regeneration process in protoplasts of both yeast and mycelial cells of C. albicans, suggesting its requirement thereof in initial steps of the cell wall synthesis.

Electrostatic Anchoring of Mn4 Single-Molecule Magnets onto Chemically Modified Multiwalled Carbon Nanotubes

2012

Two different routes that enable the electrostatic grafting of cationic single-molecule magnets (SMMs) onto the surface of chemically modified anionic multi-walled carbon nanotubes (MWNTs) are described. The chemical nature and physical properties of the resulting hybrids are discussed on the basis of a complete battery of experimental techniques. The data show that the chemical nature of the SMM unit remains intact, while its magnetic response is significantly affected by the grafting process, which is likely due to surface effects.

History of education and the struggle for intellectual liberation in post-Soviet Baltic space after the fall of the Berlin Wall

2014

This study on a “new” history of education is written from the perspective of a participant in the process of discarding Soviet intellectual and physical boundaries. The fall of the Berlin Wall has, over the past two decades, become a continuous process in post-Soviet societies, when the now liberated historians of education were faced with a new challenge, namely integration into the newly opened world. The only allowed theory, Marxism-Leninism, reduced historians of education to superficial methodology and its trivialisation. However, the collapse of the USSR did not immediately result in new theoretical concepts, because historians were busy discovering fresh facts in newly accessed arch…

Deine Sonia: A Reading from a Burned Letter by Reinhard Bölling, Translated by D. E. Rowe

2018

It was in January 1990. Finally, just two months after the Berlin Wall had fallen, I had the opportunity to spend a few days at the Mittag-Leffler Institute in Djursholm, a small town just northeast of Stockholm. The palatial villa that today houses the Institute is the former home of Gosta Mittag-Leffler (1846–1927), and on entering its doorway I felt as if I had taken a step back into the world in which he lived. For me, the Institute’s single greatest attraction lay in its archival holdings, and particularly the extensive correspondence that linked Mittag-Leffler with many of the era’s leading mathematicians. A former student of Karl Weierstrass (1815–1897), Mittag-Leffler sought to pres…

Single-Molecule Magnets: Electrostatic Anchoring of Mn4 Single-Molecule Magnets onto Chemically Modified Multiwalled Carbon Nanotubes (Adv. Funct. Ma…

2012

Possible functions of biomineralization of some Textulariid (Foraminifera) species of the Nw Iberian Margin

2016

The main goal of this work is to analyze the elemental composition of the test’s wall of some species/specimens of Textulariids (sub-class Subclass Textulariia), collected in surface sediments of the NW Iberian Margin. The elemental analyses was based on the Energy Dispersive Spectroscopy (EDS) on the Scanning Electron Microscope (SEM; Hitachi, S4100) of Textularia deltoidea, Textularia agglutinans, Sahulia conica, Karrerotextularia flintii, Siphotextularia heterostoma, Karreriella bradyi, Spiroplectammina sagittula and Arenoparrella mexicana . The elelemetal cocnentrations of the species wall were compared with the mineralogical composition (X-Ray diffraction) of the sediments of the stati…

Sedimentation properties of chitosomal chitin synthetase from the wild-type strain and the 'slime' variant of Neurospora crassa.

1989

Marked differences in the pattern of sedimentation of cellular structures were observed after isopycnic centrifugation of crude cell-free preparations from the Neurospora crassa wall-less 'slime' variant and mycelial wild-type strain. Kinetic studies of particle sedimentation showed that the various types of subcellular components, as revealed by turbidity, UV absorption, polypeptide patterns, and chitin synthetase activity determinations, sediment independently of one another. An important feature was the finding that chitin synthetase from 'slime' peaked at a median specific gravity of 1.1201 +/- 0.0036, whereas that from wild-type strain sedimented at a higher buoyant density (specific g…

TORC1 coordinates the conversion of Sic1 from a target to an inhibitor of cyclin-CDK-Cks1

2017

Eukaryotic cell cycle progression through G(1)-S is driven by hormonal and growth-related signals that are transmitted by the target of rapamycin complex 1 (TORC1) pathway. In yeast, inactivation of TORC1 restricts G(1)-S transition due to the rapid clearance of G(1) cyclins (Cln) and the stabilization of the B-type cyclin (Clb) cyclin-dependent kinase (CDK) inhibitor Sic1. The latter mechanism remains mysterious but requires the phosphorylation of Sic1-Thr(173) by Mpk1 and inactivation of the Sic1-pThr(173)-targeting phosphatase (PP2A(Cdc55)) through greatwall kinase-activated endosulfines. Here we show that the Sic1-pThr(173) residue serves as a specific docking site for the CDK phospho-a…