Search results for "SUBSTANCES"
showing 10 items of 1122 documents
Effect of a Killer Toxin of Yeast on Eucaryotic Systems
1988
The Saccharomyces cerevisiae killer toxin KT 28, which inhibits sensitive yeasts, was shown to have no effect on several pathogenic fungi or on the protozoan Trichomonas vaginalis. At concentrations of about 0.1 mg/ml, a partial inhibition of the skin pathogenic fungi Trichophyton rubrum and Microsporum canis was observed at pH 6.5. No pharmacological activity was detected in various tests with several animal organs.
COVID‐19 and tourism: What can we learn from the past?
2020
Abstract The impact of the COVID‐19 crisis on tourism flows is without precedent in terms of speed and severity. In this paper, we try to infer a possible future scenario for the tourism sector, evaluating the medium‐term effects of past pandemics on tourist arrivals. We find that pandemics lead to a persistent decline in tourist arrivals, with the effects being larger in developing and emerging countries. Interestingly, the effects are heterogeneous across countries and episodes, and depend on several economic conditions such as the overall health system performance, the severity of the shock, and the uncertainty induced by the pandemic event.
On the severity of economic downturns: Lessons from cross-country evidence
2012
Abstract We measure the severity of recessions as a function of their amplitude and duration. Within a quantile regression framework, we assess what causes economic downturns to be more or less severe. We find that the most severe downturns have striking similarities regarding cumulated domestic credit and large current account deficits.
High-pressure electrical transport measurements on p-type GaSe and InSe
2006
We performed high-pressure Hall effect and resistivity measurements in p-type GaSe and InSe up to 12 GPa. The pressure behaviour of the transport parameters shows dramatic differences between both materials. In GaSe, the hole concentration and mobility increase moderately and continuously. In InSe, the hole mobility raises rapidly and the hole concentration increases abruptly near 0.8 GPa. The observed results are attributed to the different pressure evolution of the valence-band structure in each material. In InSe a carrier-type inversion is also detected near 4.5 GPa.
Dielectrophoretic trapping of DNA origami.
2008
In this thesis three-dimensional tube-shaped DNA-origamis were dielectrophoretically trapped within lithographically fabricated nanoelectrodes. The origamis had been premade while the electrodes were fabricated specifically for these experiments with two different gapsizes, 150 nm and 400 nm. The aim of the work was to capture individual nanotubes in the gap between the electrodes by utilizing the dielectrophoretic forces present in the structure when a solution containing the origamis was put onto the electrodes and a voltage was applied. It was observed during the experiments that the success of the dielectrophoretic trapping depended strongly on the trapping conditions. This caused the t…
A D-mannose-specific lectin from Gerardia savaglia that inhibits nucleocytoplasmic transport of mRNA.
1987
A new lectin has been isolated from the coral Gerardia savaglia by affinity chromatography, using locust gum as an absorbent, and D-mannose as eluant. Final purification was achieved by Bio-Gel P300 gel filtration. The agglutinin is a protein composed of two polypeptide chains with a Mr of 14800; the two subunits are not linked by disulfide bond(s). The isoelectric point is 4.8, the amino acid composition is rich in the acidic amino acids aspartic acid and glutamic acid. The absorption maximum for the protein was at 276 nm; with a molar absorption coefficient of 1.27 X 10(5) M-1 cm-1. The lectin precipitated erythrocytes from humans (A, B and O), sheep, rabbit and carp with a titer between …
Gene within gene configuration and expression of the Drosophila melanogaster genes lethal(2) neighbour of tid [l(2)not] and lethal(2) relative of tid…
1997
In this paper, we describe the structure and temporal expression pattern of the Drosophila melanogaster genes l(2)not and l(2)rot located at locus 59F5 vis a vis the tumor suppressor gene l(2)tid described previously and exhibiting a gene within gene configuration. The l(2)not protein coding region, 1530 nt, is divided into two exons by an intron, 2645 nt, harboring the genes l(2)rot, co-transcribed from the same DNA strand, and l(2)tid, co-transcribed from the opposite DNA strand, located vis a vis. To determine proteins encoded by the genes described in this study polyclonal rabbit antibodies (Ab), anti-Not and anti-Rot, were generated. Immunostaining of developmental Western blots with t…
An acid extract from dissociation medium of sea urchin embryos, induces mesenchyme differentiation
1992
Abstract When material extracted by 1 M acetic acid from the dissociation medium of sea urchin embryos is added at low concentrations to isolated primary mesenchyme cells, it induces skeletogenesis. The same material added to dissociated blastula cells, or to embryos at the blastula stage, stimulates skeleton formation and pigment cell differentiation. On dissociated cells, it also increases cell reaggregation, thymidine incorporation and survival. On embryos, it induces exogastrulation and appearence of extraembryonic pigment cells. The activity of the extract is resistant to raised temperatures and partially to tryptic digestion but is abolished by trypsin treatment followed by heating. T…
N-Glycosylation modification of proteins is an early marker of the enterocytic differentiation process of HT-29 cells
1990
International audience; The human colon cancer cell line HT-29 remains totally undifferentiated when glucose is present in the culture medium (HT-29 Glc+), while the same cells may undergo typical enterocytic differentiation after reaching confluence when grown in glucose-deprived medium (HT-29 Glc-). Recently, we demonstrated a deficiency in the overall N-glycan processing in confluent undifferentiated cells, whereas differentiated cells follow a classical pattern of N-glycosylation. The main changes in N-glycosylation observed in confluent undifferentiated cells may be summarised as follows: 1) the conversion of high mannose into complex glycopeptides is greatly decreased; 2) this decreas…
γ2-Adaptin, a Ubiquitin-interacting Adaptor, Is a Substrate to Coupled Ubiquitination by the Ubiquitin Ligase Nedd4 and Functions in the Endosomal Pa…
2008
gamma2-Adaptin is a putative member of the clathrin adaptor protein family with unknown physiological function. We previously reported that gamma2-adaptin acts as a ubiquitin receptor by virtue of its ubiquitin-interacting motif. Here we demonstrate that this motif mediates a specific physical interaction with the ubiquitin ligase Nedd4 and promotes ubiquitination of gamma2-adaptin. By mapping regions of Nedd4 involved in binding to gamma2-adaptin, we identified its C2 domain to be essential, whereas the WW and HECT domains are dispensable. Consistent with this, we uncovered that the C2 domain of Nedd4 is ubiquitinated itself and as such is recruited by the ubiquitin-interacting motif of ga…