Escherichia coli mar and acrAB Mutants Display No Tolerance to Simple Alcohols

The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g., phage display screening, are discussed

Proteomic profiling, transcription factor modeling, and genomics of evolved tolerant strains elucidate mechanisms of vanillin toxicity in Escherichia coli.

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is an economically important flavor compound that can be made in bacterial cell factories, but toxicity is a major problem for cells producing this aromatic aldehyde. Using (i) a global proteomic analysis supported by multiple physiological experiments, mutant analyses, and inferred transcription factor modeling and (ii) adaptive laboratory evolution (ALE) of vanillin tolerance combined with genome-wide analysis of the underlying mutations, mechanisms of vanillin toxicity in Escherichia coli have been elucidated. We identified 147 proteins that exhibited a significant change in abundance in response to vanillin, giving the first detailed insight into the cellular response to this aldehyde. Vanillin caused accumulation of reactive oxygen species invoking adaptations coordinated by a MarA, OxyR, and SoxS regulatory network and increased RpoS/DksA-dependent gene expression. Differential fumarase C upregulation was found to prevent oxidative damage to FumA and FumB during growth with vanillin. Surprisingly, vanillin-dependent reduction pf copper (II) to copper (I) led to upregulation of the copA gene and growth in the presence of vanillin was shown to be hypersensitive to inhibition by copper ions. AcrD and AaeAB were identified as potential vanillin efflux systems. Vanillin-tolerant strains isolated by ALE had distinct nonsynonymous single nucleotide polymorphisms (SNPs) in gltA that led to increased citrate synthase activity. Strain-specific mutations in cpdA, rob, and marC were also present. One strain had a large (∼10-kb) deletion that included the marRAB region. Our data provide new understanding of bacterial vanillin toxicity and identify novel gene targets for future engineering of vanillin-tolerant strains of E. coli

Revisionister och nyjakobiner : En historikerstrid inför tvåhundraårsminnet av 1789

Om den stora franska revolutionen har Francois Furet nyligen sagt, att den nu äntligen efter två sekel har blivit ett "kallt" objekt, som man kan studera utan politisk lidelse.- Redan hans egna arbeten visar emellertid, att liket fortfarande kan sprattla. Furet tillhör den inflytelserika grupp av anti-marxistiska "revisionister", som på sistone har levererat ett generalangrepp mot den etablerade bilden av revolutionen som en i första hand socialt betingad omvälvning, en borgerskapets triumf över den gamla ordningen. Den bilden var mycket riktigt Marx', men den har också sedan decennier ingått i våra elementäraste läroböcker och förmodligen också i det allmänna medvetandet långt ut på den svenska högerkanten. Med en viss förenkling kan man säga, att den i sin moderna, lite allmänt historiematerialistiska form härrör från Albert Mathiez, Georges Lefebvre och Albert Soboul, efter varandra innehavare av professuren i revolutionshistoria vid Sorbonne, Soboul tillika aktiv inom clet franska kommunistpartiet. Och det är alltså i harnesk mot dessa nyjakobiner, som motståndarna under de senaste decennierna har slutit sig samman och knutit an till den revisionistiske pionjären, engelsmannen Alfred Cobban.Tidskriften Kronos: historia i skola och samhälle gavs ut vid Linköpings univeristet mellan åren 1988-1991.</p

Escherichia coli mar and acrAB Mutants Display No Tolerance to Simple Alcohols

The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g.,phage display screening, are discussed

"Institutions", What Is In a Word? A Critique of the New Institutional Economics

This thesis is a critique of the New Institutional Economics (NIE) in economic history. The focus is on explanations to the origin and development of capitalist institutions within NIE. After a methodological discussion in chapter 1 the author investigates into how well NIE succeeds in explaining capitalist institutions. In chapters 2 and 3, a conceptual critique of the theoretical bases of evolution and competition, behavioural assumptions, property rights, and transaction costs in NIE is conducted. In chapters 4 and 5, some of the most influential theories of the firm within NIE are accounted for, analysed and criticised. In chapters 6 and 7, an account and criticism of the institutional economic history of Douglass North, the main example of economic history from the NIE perspective, is conducted. In the concluding chapter 8, the author points out what necessitates the institution concept in NIE, thereby finding a key to how one could avoid some of the problems associated with it. In the appendix the contribution of Karl Polanyi is analysed. The main results of the analysis are: (i) In the conceptualisation of the market, the logic of the economic system and the development of individuals, history does not matter to the validity of the model in NIE. NIE transfers the capitalist economic logic into every possible economic system. The economy remains an ahistorical, non-realist, purely theoretical construct. Hence, conceptually the capitalist economy cannot be given a history. (ii) In the explanations to economic development in NIE, production, markets, prices, etc. increasingly lose their explanatory power. Rather than seeing economic development as a causal factor to societal evolution, economic development becomes a consequence of non-economic institutions. To analytically achieve economic evolution and development in such a model it is necessary to first separate an institutional sphere from the economy, and then reunite it with the economic sphere again, thereby allowing for a historical development to the economy. Were the economy defined in a social manner – as a set of social relations and structures – at the outset, such a course would not be necessary. This suggests that the particular venture of NIE of introducing institutions to the model is a sign of the theoretical inadequacy and asocial, ahistorical conceptualisation of the economic theory at the outset, rather than anything else

Development of a mordern canopy swing.

Denna rapport är ett examensarbete inom maskinteknik på c-nivå (15hp). Då författaren ansåg att dagens hammockar inte utvecklats speciellt mycket sedan de blev populära i Sverige på 60-talet, valde han att ägna detta arbete åt att försöka ta fram en mer modern sådan. Projektet har huvudsakligen handlat om produktutveckling och design där mycket tid spenderats på att lösa alla de olika problem som de satta kraven på nya funktioner bidragit till. Arbetet startade med en omfattande förstudie. Därefter vidareutvecklades de olika idéer som framkom under förstudien ytterligare. Detta skedde först med hjälp av papper och penna, men överfördes senare till digital form. Det var oftast först då som en idé var möjlig att testa fullt ut. Resultatet är en hammock med en nutida design och flertalet nya funktioner, vilka i rapporten presenteras i form av bilder på den cad-modell som framställdes.This work is a thesis in mechanical engineering at c-level (15hp). The author decided that he wanted to dedicate this work to try to develop the canopy swings because he saw potential to do so. The reason for this was mainly the fact that they have hardly been developed at all since they became popular in the 1960s here in Sweden. The project has mainly been about product development and design, where a lot of time has been spent on trying to solve all the different problems that the set demands resulted in. The work started with an extensive feasibility study. Thereafter, the ideas that emerged during the preliminary study where developed further. This was first done by using paper and pencil, but was later transferred to digital form. It was most often only possible to fully test an idea when that was made. The result is a hammock with a modern design and several new features, which in the report are presented as images of the CAD model that was made

Educational relationships and their impact on students' academic achievement : A qualitative study of teachers' thoughts about teaching relationships

Examensarbetets syfte är att studera lärares beskrivningar av arbetet med och betydelsen av pedagogiska relationer.   Studien har tre frågeställningar: Vad anger lärare att de har för uppfattningar om pedagogiska relationer, hur beskriver de sitt arbete för att skapa pedagogiska relationer samt vad har dessa relationer för betydelse för elevernas studieprestationer enligt lärarna.   För att studera hur man som lärare kan arbeta för att skapa pedagogiska relationer och för att få reda på hur dessa relationer påverkar elevernas studieprestationer så används en kvalitativ forskningsmetod. Empirin består av intervjuer med fyra lärare från två olika skolor. För att få en djupare förståelse om ämnet och för att lättare kunna förstå resultatet så hämtas kunskap ur tidigare forskning och bidrag till tolkningen ur olika teorier. Informanterna beskriver pedagogiska relationer och dess innebörd olika. En del av lärarna anser att pedagogiska relationer har med elevernas kunskapsutveckling att göra och hur man som pedagog lär ut denna kunskap. Andra anser att pedagogiska relationer har med det personliga samsepelet mellan läraren och eleven att göra. Resultatet visar att man kan arbeta på olika sätt för att skapa pedagogiska relationer. Samtliga informanter anser att lärarens bemötande och förväntningar påverkar elevernas studieprestationer.The thesis aims to study teachers' descriptions of the work and the importance of pedagogical relationships.  The study has three questions: What does the teacher that they have for conceptions of pedagogical relationships , how do they describe their work to create educational relationships and what these relationships mean for students' academic performance according to the teachers. To study how teachers can work to create educational relationships and to find out how these relationships affect students' academic performance so used a qualitative research method. The empirical material consists of interviews with four teachers from two different schools. To gain a deeper understanding of the topic and to enhance our understanding of the result to retrieve knowledge from previous research and contributions to the interpretation of the various theories. The informants describe educational relationship and its meaning differently. Some of the teachers believe that pedagogic relationships with pupils' knowledge to do and how you as a teacher teach this knowledge. Others think that the educational relationship is with the personal samsepelet between the teacher and the student to do. The result shows that it can work in different ways to create educational relationship. All the informants believe that the teacher's attitude and expectations affect students' academic performance

If you’re happy and you know it clap your hands? : Applause as ritual during the classical concert.

Uppsatsens syfte är att bidra till en djupare förståelse för hur applåden fungerar som en ritual under den klassiska konserten samt hur praxis kring den traderas, då den klassiska konsertens ritualer och normer kan kännas underliga och avskräckande för den som aldrig närvarat vid en sådan. Med en kvalitativ intervjumetod har två informanter frågats om deras upplevelser och tankar kring applåder och den klassiska konserten. Det empiriska material som skapats används som grund för en analys med hjälp av Bourdieus sociologiska begrepp fält, habitus och kapital, Ronald L. Grimes tankar kring det rituella fältet, samt övergripande ritualteori för att bidra med en djupare förståelse kring applåden i samband med den klassiska konserten. Applåden som ritual skapar social mening, signalerar uppskattning för det som publiken upplevt och bildar även en känsla av grupptillhörighet och solidaritet. Applåden upplevs vara viktig för att de som deltagit under konserten ska få utlopp för sina känslor och kommunicera detta mellan publik och musiker, och även sinsemellan den sittande publiken, särskilt i en miljö som kan upplevas som disciplinerad och stram. Traderingen av applådens praxis sker delvis genom misstag då en individ prövar sig fram i konsertupplevelsen, samt genom observation av erfarna i publiken. Presentatörer och andra nyckelpersoner kan bidra med en förklaring av en konsert innan den börjar för att underlätta för deltagarna, och det rika material som finns på olika konserthus hemsidor bidrar med en chans att låta den nyfikna förbereda sig innan den tar klivet in i en ny miljö. Även om det kan applåderas fel under en konsert så kan detta under vissa förutsättningar leda till en delad positiv upplevelse som på sikt kan leda till en lättad syn på applåden under den klassiska konserten