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Il saggio ricostruisce, e mette in relazione fra loro, le tesi e i paradigmi concettuali presenti nelle ricerche filosofiche sul problema della validità di norme raccolte nella quarta sezione (IV. Validità di norme) del volume., This essays offers a survey of (and draws possible connections among) the theses and the conceptual paradigms proposed in the philosophical researches on the question of the validity of norms that are recollected in the fourth section (IV: Validity of norms) of the book.

Il saggio ricostruisce, e mette in relazione fra loro, le tesi e i paradigmi concettuali presenti nelle ricerche sociologiche sulla raccolte nella quinta sezione (V. Filosofie sociologiche della norma) del volume, evidenziandone i contributi più significativi per l’indagine filosofica del modo in cui le norme operano e incidono sui comportamenti degli agenti. I contributi offerti da queste ricerche sono illuminati dall’autore attraverso l’introduzione dell’originale concetto di “operanza di norme” e dalla tesi secondo la quale in alcune di queste ricerche le norme appaiono come un mero epifenomeno della normatività sociale. Accanto al concetto di “operanza di norme”, l’autore introduce un secondo concetto inedito per l’indagine del modo in cui le norme operano e incidono sul comportamento degli agenti: il concetto di “agire nomotrofico”., This essays offers a survey of (and draws possible connections among) the theses and the conceptual paradigms proposed in the sociological researches on norms recollected in the fifth section (V. Sociological philosophies of norm) of the book, and it stresses the contributions that are most relevant for the philosophical investigation of the way norms do operate and have influence on behaviour. These contributions are enlightened by the author through the original introduction of the concept of “norm-operancy”, and through the thesis that in some of these researches norms appear as a mere epiphenomenon of social normativity. Besides the concept of “norm-operancy”, the author introduces a second new concept for the investigation of the way norms operate and have influence on behaviour: the concept of “nomotrophical acting”.

Il saggio ricostruisce il panorama delle ricerche filosofiche sulla norma nelle quali si inscrivono i saggi raccolti nel volume, evidenziandone i temi, le tesi, gli stili di ricerca e i paradigmi concettuali più rilevanti, e ripresenta, in maniera provocatoria, l'ipotesi che il termine 'norma' sia inadeguato per fare riferimento alla molteplicità di oggetti che le ricerche raccolte nel volume portano alla luce., This essay offers a survey of the philosophical researches on norms in which the essays recollected in this volume are inscribed. It stresses the most relevant themes, theses, research styles, and conceptual paradigms proposed by those essays, and it provocatively proposes the hypothesis that the term ‘norm’ be inadequate to make reference to the plurality of phenomena investigated in those essays.

A fluidic obstacle has been proposed as an alternative to conventional deflagration-to-detonation transition (DDT) enhancement devices for use in a Pulsed Detonation Engine (PDE). Experimental results have been obtained utilizing unsteady reacting and steady non-reacting flow to gain insight on the relative performance of a fluidic obstacle. Using stoichiometric premixed hydrogen-air, transition to detonation has been achieved using solely a fluidic obstacle with comparable DDT distances to that of a physical orifice plate. Flame acceleration is achieved due to the intense turbulent mixing characteristics inherent of a high-velocity jet and the blockage created by the virtual obstacle. Turbulence intensity (T.I.) measurements, taken downstream of both obstacles with hot-film anemometry during non-reacting steady flow, show a conservative trend that a fluidic obstacle produces approximately a 240% increase in turbulence intensity compared to that of a physical obstacle. Ignition times were reduced approximately 45%, attributable to the increase in upstream T.I. levels relative to the fluidic obstacle during the fill portion of the PDE's cycle. Transition to detonation was obtained for injection compositions of both premixed stoichiometric hydrogen-air and pure air., Presented at the AIAA Aerospace Sciences Meeting (49th) held in Orlando, FL on 4-7 Jan 2011.

Cis-trans isomerization of unsaturated fatty acids is a crucial adaptive reaction of Pseudomonas and Vibrio species to toxic organic compounds or other environmental stress factors. In order to test the long-term performance of this adaptive mechanism as well as to assess its application as biomarker for environmental contamination studies were performed in batch cultures and in continuously running sand columns, simulating long-term contamination with bisphenol A (BPA). In short-term grown batch cultures a high correlation between trans/cis ratio and added BPA concentration and toxicity was observed. In contrary, this did not occur in the case of long-term sand columns. An increase in trans/cis ratio of unsaturated fatty acids only appeared in a limited period of time. Afterwards the trans/cis ratio reached the values measured for non-stressed cultures. Cis-trans isomerization is only an urgent response mechanism that is later substituted by other adaptive mechanisms. Therefore, it can be concluded that the trans/cis ratio of unsaturated fatty acids was shown not to be an appropriate biomarker for durable stress in the environment.

A bacterium able to degrade bisphenol A (BPA) as sole carbon and energy source was isolated from a planted fixed bed reactor continuously running with BPA. The Gram-negative aerobic bacterium was identified as Cupriavidus (formerly Wautersia, Ralstonia) basilensis JF1 by using physiological characterization, BIOLOG and 16S rRNA-analysis. The detected cellular degradation intermediates revealed that the strain contains of a similar pathway for the metabolism of BPA as recently described for a Sphingomonas strain. Furthermore, C. basilensis JF1 is able to utilise phenol, 4-isopropylphenol, ethanol, methanol, acetone and several other aromatic and aliphatic compounds as sole carbon sources. By using phenol as biostimulant either in shake cultures or in continuously running sand columns, the BPA-degradation rate of the bacterium could be significantly enhanced.

The effect of different solvents and pollutants on the cellular fatty acid composition of three bacterial strains: Thauera aromatica, Geobacter sulfurreducens and Desulfococcus multivorans, representatives of diverse predominant anaerobic metabolisms was investigated. As the prevailing adaptive mechanism in cells of T. aromatica and G. sulfurreducens whose cellular fatty acids patterns were dominated by palmitic acid (C16:0) and palmitoleic acid (C16:1cis), the cells reacted by an increase in the degree of saturation of their membrane fatty acids when grown in the presence of sublethal concentrations of the chemicals. Next to palmitic acid C16:0, the fatty acid pattern of D. multivorans was dominated by anteiso-branched fatty acids which are characteristic for several sulfate-reducing bacteria. The cells responded to the solvents with an increase in the ratio of straight-chain saturated (C14:0, C16:0, C18:0) to anteiso-branched fatty acids (C15:0anteiso, C17:0anteiso, C17:1anteiso?9cis). The results show that anaerobic bacteria react with similar mechanisms like aerobic bacteria in order to adapt their membrane to toxic organic solvents. The observed adaptive modifications on the level of membrane fatty acid composition can only be carried out with de novo synthesis of the fatty acids which is strictly related to cell growth. As the growth rates of anaerobic bacteria are generally much lower than in the so far investigated aerobic bacteria, this adaptive response needs more time in anaerobic bacteria. This might be one explanation for the previously observed higher sensitivity of anaerobic bacteria when compared with aerobic ones.

Single-ejector, multi-tube pulsed detonation engine configurations are examined utilizing high speed Schlieren and coherent structural velocimetry. The mechanisms of ejector augmentation are evident in secondary air entrainment and induced flow across the ejector lip. An axisymmetric ejector with both a linear array and a more compact box array of detonation tubes was examined. Good secondary entrainment and subsequent ejector flow was observed, supporting previous results indicating off-axis effects are relatively insignificant to ejector thrust augmentation. A linear ejector with linear detonation tubes revealed limited secondary flow engagement with the ejector lip, likely due to structural ribs.

A laccase from the aquatic ascomycete Phoma sp. UHH 5-1-03 (DSM 22425) was purified upon hydrophobic interaction and size exclusion chromatography (SEC). Mass spectrometric analysis of the laccase monomer yielded a molecular mass of 75.6 kDa. The enzyme possesses an unusual alkaline isoelectric point above 8.3. The Phoma sp. laccase undergoes pH-dependent dimerisation, with the dimer ( approximately 150 kDa, as assessed by SEC) predominating in a pH range of 5.0 to 8.0. The enzyme oxidises common laccase substrates still at pH 7.0 and 8.0 and is remarkably stable at these pH values. The laccase is active at high concentrations of various organic solvents, all together indicating a considerable biotechnological potential. One laccase gene (lac1) identified at the genomic DNA level and transcribed in laccase-producing cultures was completely sequenced. The deduced molecular mass of the hypothetical protein and the predicted isoelectric point of 8.1 well agree with experimentally determined data. Tryptic peptides of electrophoretically separated laccase bands were analysed by nano-liquid chromatography-tandem mass spectrometry. By using the nucleotide sequence of lac1 as a template, eight different peptides were identified and yielded an overall sequence coverage of about 18%, thus confirming the link between lac1 and the expressed laccase protein.

A laccase from the aquatic ascomycete Phoma sp. UHH 5-1-03 (DSM 22425) was purified upon hydrophobic interaction and size exclusion chromatography (SEC). Mass spectrometric analysis of the laccase monomer yielded a molecular mass of 75.6 kDa. The enzyme possesses an unusual alkaline isoelectric point above 8.3. The Phoma sp. laccase undergoes pH-dependent dimerisation, with the dimer (~150 kDa, as assessed by SEC) predominating in a pH range of 5.0 to 8.0. The enzyme oxidises common laccase substrates still at pH 7.0 and 8.0 and is remarkably stable at these pH values. The laccase is active at high concentrations of various organic solvents, all together indicating a considerable biotechnological potential. One laccase gene (lac1) identified at the genomic DNA level and transcribed in laccase-producing cultures was completely sequenced. The deduced molecular mass of the hypothetical protein and the predicted isoelectric point of 8.1 well agree with experimentally determined data. Tryptic peptides of electrophoretically separated laccase bands were analysed by nano-liquid chromatography-tandem mass spectrometry. By using the nucleotide sequence of lac1 as a template, eight different peptides were identified and yielded an overall sequence coverage of about 18%, thus confirming the link between lac1 and the expressed laccase protein.

The effect of seven important pollutants and three representative organic solvents on growth of Thauera aromatica K172, as reference strain for nitrate-reducing anaerobic bacteria, was investigated. Toxicity in form of the effective concentrations (EC50) that led to 50% growth inhibition of potential organic pollutants such as BTEX (benzene, toluene, ethylbenzene, and xylene), chlorinated phenols and aliphatic alcohols on cells was tested under various anaerobic conditions. Similar results were obtained for Geobacter sulfurreducens and Desulfococcus multivorans as representative for Fe3+-reducing and sulphate-reducing bacteria, respectively, leading to a conclusion that anaerobic bacteria are far more sensitive to organic pollutants than aerobic ones. Like for previous studies for aerobic bacteria, yeast and animal cell cultures, a correlation between toxicity and hydrophobicity (log P values) of organic compounds for different anaerobic bacteria was ascertained. However, compared to aerobic bacteria, all three tested anaerobic bacteria were shown to be about three times more sensitive to the tested substances.

Based on the current literature, a risk/benefit analysis of the antimicrobial impregnation of surgical sutures with triclosan is performed, focussing on efficacy and indication, risk of resistance development, toxicological characteristics, and environmental tolerance. From a toxicological point of view, there are no restrictions for triclosan-impregnated suturing materials. Environmental tolerance is also acceptable for this application area, because the amounts of triclosan involved pose no problems in terms of degradability. The use of surgical suturing material coated with triclosan is seen especially in contaminated wounds or where the risk of infection is high. In order to meet this requirement, the antimicrobial properties of triclosan are particularly emphasized. Both in vitro and in vivo, triclosan is highly effective against Staphylococcus spp. , including MRSA, the pathogens most frequently involved in postoperative wound infections. Triclosan is not effective against Pseudomonas aeruginosa , Serratia marcescens and Alcaligenes spp. , due to their intrinsic resistance against this agent. As long as the inducible resistance in vitro against triclosan is not clinically relevant, it does not speak against triclosan use in suturing material, especially because pure triclosan is applied only to a specific, limited area for a short time. However, because triclosan can induce in vitro the development of cross-resistances to antibiotics, the implementation of this agent must be exclusively limited to medically founded indications., Auf der Grundlage des aktuellen Schrifttums wird die antimikrobielle Imprägnierung von chirurgischem Nahtmaterial mit Triclosan einer Nutzen-Risiko-Bewertung mit den Schwerpunkten Wirksamkeit und Indikation, Risiko der Resistenzentwicklung, toxikologische Charakteristik und Umweltverträglichkeit unterzogen.Aus toxikologischer Sicht gibt es keine Einschränkungen für mit Triclosan imprägniertes Nahtmaterial. Auch die Umweltverträglichkeit ist für diesen Einsatzbereich gegeben, weil die anfallenden Mengen von Triclosan kein Problem für die Abbaubarkeit darstellen. Der Einsatz von mit Triclosan beschichtetem chirurgischem Nahtmaterial wird allerdings speziell bei kontaminierten Wunden oder bei hohem Infektionsrisiko gesehen. Um dieser Anforderung gerecht zu werden, stehen daher die antimikrobiellen Eigenschaften von Triclosan besonders in Vordergrund.Triclosan ist in vitro und in vivo hoch wirksam gegen Staphylococcus spp . einschließlich MRSA und erfasst damit die häufigsten Erreger postoperativer Wundinfektionen. Gegen Pseudomonas aeruginosa , Serratia marcescens und Alcaligenes spp . ist auf Grund der intrinsischen Resistenz gegen Triclosan allerdings keine Wirksamkeit zu erwarten.Solange die in vitro induzierbare Resistenzentwicklung gegen Triclosan ohne klinische Relevanz ist, spricht diese nicht gegen den Einsatz von Triclosan in Nahtmaterial, zumal es sich hierbei um den punktuellen kurzfristigen Einsatz reinen Triclosans handelt. Da in vitro durch Triclosan eine Resistenzentwicklung mit Kreuzresistenz zu Antibiotika induzierbar ist, sollte der Einsatz dieses Wirkstoffs allerdings ausnahmslos auf medizinisch begründete Indikationen limitiert werden.

The effect of nozzles on the impulse obtained from a detonation tube of circular cross section has been the focus of many experimental and numerical studies. In these cases, the simplified detonation tube is closed at one end (forming the thrust surface) and open at the other end, enabling the attachment of an extension. A flowfield analysis of a detonation tube with an extension requires considering unsteady wave interactions making analytical and accurate numerical predictions difficult (especially in complicated extension geometries). To predict the impulse obtained from a detonation tube with an extension (considered a partially filled detonation tube), we utilize data from other researchers to generate a partial-fill correlation.

The strain Pseudomonas sp. strain ADP is able to degrade atrazine as a sole nitrogen source and therefore needs a single source for both carbon and energy for growth. In addition to the typical C source for Pseudomonas, Na2-succinate, the strain can also grow with phenol as a carbon source. Phenol is oxidized to catechol by a multicomponent phenol hydroxylase. Catechol is degraded via the ortho pathway using catechol 1,2-dioxygenase. It was possible to stimulate the strain in order to degrade very high concentrations of phenol (1,000 mg/liter) and atrazine (150 mg/liter) simultaneously. With cyanuric acid, the major intermediate of atrazine degradation, as an N source, both the growth rate and the phenol degradation rate were similar to those measured with ammonia as an N source. With atrazine as an N source, the growth rate and the phenol degradation rate were reduced to ∼35% of those obtained for cyanuric acid. This presents clear evidence that although the first three enzymes of the atrazine degradation pathway are constitutively present, either these enzymes or the uptake of atrazine is the bottleneck that diminishes the growth rate of Pseudomonas sp. strain ADP with atrazine as an N source. Whereas atrazine and cyanuric acid showed no significant toxic effect on the cells, phenol reduces growth and activates or induces typical membrane-adaptive responses known for the genus Pseudomonas. Therefore Pseudomonas sp. strain ADP is an ideal bacterium for the investigation of the regulatory interactions among several catabolic genes and stress response mechanisms during the simultaneous degradation of toxic phenolic compounds and a xenobiotic N source such as atrazine.