Search results for "Erich"

Substanssi dualismi v. filosofinen behaviorismi

2017

Tämän tutkimuksen tarkoituksena on tarkastella tanskalaisen filosofin Erich Klawonnin argumentteja minä-substanssin puolesta ja englantilaisen filosofin Gilbert Rylen kritiikkiä kartesiolaiselle dualismille. Klawonn argumentoi, että ruumis ja mieli ovat kaksi erillistä substanssia, fyysinen ja aineeton minä-substanssi. Hänelle minä-substanssi edustaa sellaista, jolla on kattavat piirteet. Näitä piirteitä ovat mentaalisuus, yksilöllistäminen, ajan vaikuttamattomuus ja kuolemasta selviytyminen. Gilbert Rylen argumentit edustavat kriittistä näkemystä kartesiolaiselle dualismille. Hänen pohtii, ettei ole mitään aavemaista entiteettiä, joka hallitsisi ruumista. Näin ollen, ”aave koneessa dogmi” …

Verwaltungs-Bericht der Rigaschen Stadt-Cassa für das Jahr 1867

1868

Rapid evolutionary adaptation to elevated salt concentrations in pathogenic freshwater bacteria Serratia marcescens.

2014

Rapid evolutionary adaptions to new and previously detrimental environmental conditions can increase the risk of invasion by novel pathogens. We tested this hypothesis with a 133-day-long evolutionary experiment studying the evolution of the pathogenic Serratia marcescens bacterium at salinity niche boundary and in fluctuating conditions. We found that S. marcescens evolved at harsh (80 g/L) and extreme (100 g/L) salt conditions had clearly improved salt tolerance than those evolved in the other three treatments (ancestral conditions, nonsaline conditions, and fluctuating salt conditions). Evolutionary theories suggest that fastest evolutionary changes could be observed in intermediate sele…

Role of glycine-82 as a pivot point during the transition from the inactive to the active form of the yeast Ras2 protein

1991

AbstractRas proteins bind either GDP or GTP with high affinity. However, only the GTP-bound form of the yeast Ras2 protein is able to stimulate adenylyl cyclase. To identify amino acid residues that play a role in the conversion from the GDP-bound to the GTP-bound state of Ras proteins, we have searched for single amino acid substitutions that selectively affected the binding of one of the two nucleotides. We have found that the replacement of glycine-82 of the Ras2 protein by serine resulted in an increased rate of dissociation of Gpp(NH)p, a nonhydrolysable analog of GTP, while the GDP dissociation rate was not significantly modified. Glycine-82 resides in a region that is highly conserve…

Energetic aspects of intramolecular coupling between the nucleotide binding site and the distal switch II region of the yeast RAS2 protein

1994

AbstractWe have studied the interaction of the yeast RAS2 protein with guanine nucleotides using energetic parameters for the dissociation of RAS·nucleotide complexes. The results indicated that a Gly → Ser substitution at position 82 led to an altered interaction with GppNHp and, to a lesser extent, also with GDP. It was also possible to conclude that structural perturbation of Gly82 can stimulate nucleotide release by decreasing the energetic barrier for nucleotide dissociation. This, together with the observation that residues 80 and 81 are involved in the response of RAS to nucleotide exchange factors without affecting GDP binding per se, suggests a potential mechanism for exchange fact…

A natural A/T-rich sequence from the yeast FBP1 gene exists as a cruciform in Escherichia coli cells.

1993

Abstract Palindromic or semipalindromic sequences can adopt cruciform structures in DNA in vitro. It has been demonstrated in some cases that A/T-rich cruciforms exist also in vivo in Escherichia coli. The biological function of those structures is not understood although putative cruciforms have been found in interesting locations on replication origins, operators, or transcriptional termination regions. Here we show by means of the use of structure-dependent nucleases that the 3′ end of the yeast FBP1 gene contains a stable cruciform both in vitro and in E. coli cells and that in both cases, its extrusion depends on the DNA supercoiling state.

S. Typhimurium virulence changes caused by exposure to different non-thermal preservation treatments using C. elegans

2017

The aims of this research study were: (i) to postulate Caenorhabditis elegans (C. elegans) as a useful organism to describe infection by Salmonella enterica serovar Typhimurium (S. Typhimurium), and (ii) to evaluate changes in virulence of S. Typhimurium when subjected repetitively to different antimicrobial treatments. Specifically, cauliflower by-product infusion, High Hydrostatic Pressure (HHP), and Pulsed Electric Fields (PEF). This study was carried out by feeding C. elegans with different microbial populations: E. coli OP50 (optimal conditions), untreated S. Typhimurium, S. Typhimurium treated once and three times with cauliflower by-product infusion, S. Typhimurium treated once and f…

Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics.

2016

International audience; Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enteri…

Novel Penicillin-Type Analogues Bearing a Variable Substituted 2-Azetidinone Ring at Position 6: Synthesis and Biological Evaluation

2015

The synthesis and the biological activity of novel semi-synthetic β-lactam compounds containing an azetidinone moiety joined to the amino-nitrogen of the (+)-6-aminopenicillanic acid (6-APA) as new antibacterial agents is reported. The synthesized compounds were screened for their in vitro antimicrobial activity against a panel of Gram positive and Gram negative pathogens and environmental bacteria. Tested compounds displayed good antimicrobial activity against all tested Gram positive bacteria and for Staphylococcus aureus and Staphylococcus epidermidis antimicrobial activity resulted higher than that of the reference antibiotic. Additionally, in vitro cytotoxic screening was also carried …

Evaluation of the SOS/umu-test post-treatment assay for the detection of genotoxic activities of pure compounds and complex environmental mixtures.

2000

This study presents an evaluation of the SOS/umu-test after introducing an additional dilution and incubation in the post-treatment assay. This treatment reduces the influence of coloured test compounds that otherwise affect the colorimetric determination of the beta-galactosidase activity and the bacterial growth measurement during the testing of complex environmental samples. The post-treatment assay significantly increased the beta-galactosidase activity and consequently the enzyme induction ratios at higher doses of model genotoxins 4-nitroquinoline-N-oxide, N-methyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, benzo(a)pyrene with low or no effect on the sensitivity of the test itsel…