Lehtori Irja Klemola 2/1 1963

Kirje 2.1.1963

Toimitusjohtaja Irja Ketonen 31/8 1972

Kirje 31.8.1972

Affidabilità dell'isolamento di spira di motori alimentati da convertitori di potenza: Valutazione dello stress e verifiche sperimentali

Il testo propone uno studio dell'affidabiltà dell'isolamento di spira per macchine elettriche rotanti, aventi sistema isolante di tipo II, alimentate mediante convertitori di potenza. In particolare vengono descritte le prove di vita accelerate svolte al variare del tempo di salita della tensione, le simulazione effettuate con il metodo degli elementi finiti ed un metodo analitico utilizzato per uniformare lo stress all'interno degli avvolgimenti di statore.

Die Verbindung der Prager Familien Oettingen-Spira (Wedeles) -Bondi

Tobias Jakobovits

Die Grabschriften der Familie Fränkel-Spira in Prag

Marcus Brann

Die Grabschriften der Familie Fränkel-Spira in Prag

Marcus Brann

Neue Beiträge zur Geschichte der Familie Fränkel-Spira

Ludwig Lazarus

Camilla Spira, Brustbild

Signatur des Originals: S 36/F06649

Irja' ila Nafsika: Suhraward's apperception of the self in light of Avicenna

Shihāb al-Dīn Suhrawardī (d.687/1191) proposed a theory of apperception that constitutes the core of his “illuminative” epistemology. His theory of apperception purports to account for the soul’s immediate, reflexive, and unmediated knowledge of its own essence. Apperception may be defined as the direct experience the soul has of its essence. A closer examination of the Avicennan tradition (Avicenna died in 420/1037) reveals the existence of a number of arguments for the demonstration of an apperception of the self/soul similar to the arguments Suhrawardī later proposes. Contrary to admitted views, Avicenna had tackled issues related to the soul’s apperception, a type of perception distinct from the soul’s intellection of its essence. Avicenna alluded to the existence of a mode of perception specific to the soul that would guarantee both the soul’s unity and its personal identity. This apperception is defined as an unmediated presence of the soul to itself. These elements recur in Suhrawardī’s theory of apperception and numerous versions of Avicenna’s arguments for the demonstration of the presential nature of apperception

The constancy of global regulation across a species: the concentrations of ppGpp and RpoS are strain-specific in Escherichia coli

Background: Sigma factors and the alarmone ppGpp control the allocation of RNA polymerase to promoters under stressful conditions. Both ppGpp and the sigma factor sigma(S) (RpoS) are potentially subject to variability across the species Escherichia coli. To find out the extent of strain variation we measured the level of RpoS and ppGpp using 31 E. coli strains from the ECOR collection and one reference K-12 strain. Results: Nine ECORs had highly deleterious mutations in rpoS, 12 had RpoS protein up to 7-fold above that of the reference strain MG1655 and the remainder had comparable or lower levels. Strain variation was also evident in ppGpp accumulation under carbon starvation and spoT mutations were present in several low-ppGpp strains. Three relationships between RpoS and ppGpp levels were found: isolates with zero RpoS but various ppGpp levels, strains where RpoS levels were proportional to ppGpp and a third unexpected class in which RpoS was present but not proportional to ppGpp concentration. High-RpoS and high-ppGpp strains accumulated rpoS mutations under nutrient limitation, providing a source of polymorphisms. Conclusions: The ppGpp and sigma(S) variance means that the expression of genes involved in translation, stress and other traits affected by ppGpp and/or RpoS are likely to be strain-specific and suggest that influential components of regulatory networks are frequently reset by microevolution. Different strains of E. coli have different relationships between ppGpp and RpoS levels and only some exhibit a proportionality between increasing ppGpp and RpoS levels as demonstrated for E. coli K-12.