The Jackiw-Pi model and its symmetries

The non-Abelian gauge model proposed by Jackiw and Pi, which generates an even-parity mass term in three space-time dimensions, is revisited in this letter. All the symmetries of the model are collected and established by means of BRS invariance and Slavnov-Taylor identity. The path for the perturbatively quantization of the Jackiw-Pi model, through the algebraic method of renormalization, is presented.Comment: 5 page

Colojejunal Fistula Resulting from a D-PEJ Feeding Tube

Numerous procedures have been developed to provide adequate enteral nutrition to patients with gastrointestinal disorders. Previously, operative placement of a feeding gastrostomy or jejunostomy tube was the accepted means of gaining chronic enteral access. However, improved technology and experience with endoscopic techniques have quickly replaced primary operative placement of enteral access. Direct percutaneous endoscopic jejunostomy (D-PEJ) is a procedure that was designed to deliver enteral feeding solutions for patients with proximal disease after unsatisfactory results from percutaneous endoscopic gastrostomy tubes with jejunal extensions (PEG-J). As with any procedure, it is associated with complications. We present the first reported case of a colojejunal fistula resulting from a D-PEJ placement. While D-PEJ has been shown to be relatively safe, complications related to the inherent limitations of the procedure need to be considered when the patient experiences unusual post-procedure symptoms and worked up appropriately

Assessment of crash fire hazard of LH sub 2 fueled aircraft

The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously

Scaling of transverse nuclear magnetic relaxation due to magnetic nanoparticle aggregation

The aggregation of superparamagnetic iron oxide (SPIO) nanoparticles decreases the transverse nuclear magnetic resonance (NMR) relaxation time T2 of adjacent water molecules measured by a Carr-Purcell-Meiboom-Gill (CPMG) pulse-echo sequence. This effect is commonly used to measure the concentrations of a variety of small molecules. We perform extensive Monte Carlo simulations of water diffusing around SPIO nanoparticle aggregates to determine the relationship between T2 and details of the aggregate. We find that in the motional averaging regime T2 scales as a power law with the number N of nanoparticles in an aggregate. The specific scaling is dependent on the fractal dimension d of the aggregates. We find T2 N^{-0.44} for aggregates with d=2.2, a value typical of diffusion limited aggregation. We also find that in two-nanoparticle systems, T2 is strongly dependent on the orientation of the two nanoparticles relative to the external magnetic field, which implies that it may be possible to sense the orientation of a two-nanoparticle aggregate. To optimize the sensitivity of SPIO nanoparticle sensors, we propose that it is best to have aggregates with few nanoparticles, close together, measured with long pulse-echo times.Comment: 20 pages, 3 figures, submitted to Journal of Magnetism and Magnetic Material

Self-Interest, Love, and Economic Justice: A Dialogue Between Classical Economic Liberalism and Catholic Social Teaching

This essay seeks to start a dialogue between two traditions that historically have interpreted the economy in opposing ways: the individualism of classic economic liberalism (CEL), represented by Adam Smith and Milton Friedman, and the communitarianism of Catholic social teaching (CST), interpreted primarily through the teachings of popes and secondarily the U.S. Catholic bishops. The present authors, an economist and a moral theologian who identify with one or the other of the two traditions, strive to clarify objectively their similarities and differences with the opposing perspective. Section one focuses on each position\u27s perspective of love of self and love of others. We find both CEL and CST saying that self-love, rightly understood, constitutes a moral good and that the love of others serves as an important principle in the political economy. We find less agreement in section two regarding justice and rights, but even here, we discover a few surprises. Both traditions uphold justice (giving to each party what is due) as essential to the political economy, and recognize some similarity in that type of justice called commutative. We note, however, substantial differences regarding a second type of justice that we call public justice. First, they differ over the extent to which government should be involved. Here the meaning of rights, especially that of individual freedom, arises. Secondly, the traditions diverge over whether benevolence as a motivator ought to serve as a partner for public justice. Thirdly, CEL in general opposes CST\u27s emphasis on social justice that calls upon institutions to be proactive in helping citizens and groups to become active participants in the economy. We conclude our essay by summarizing our discoveries and by suggesting areas for further dialogue

Redesenhar os mapas do encontro: trabalho de cuidado com os migrantes

L'articolo riprende un percorso di ricerca, che ha coinvolto diversi gruppi di professionisti e la scrivente in quanto pedagogista e ricercatrice, iniziato pi\ufa di dieci anni fa in un territorio del Nord dell'Italia, con l'obbiettivo di creare nuovi dispositivi nel lavoro in ambito sociale e psicopedagogico con i migranti. Grazie alla riflessione, all'ascolto dell'esperienza, alla formazione continua e alla rielaborazione durante il processo insieme a chi quotidianamente \ue8 impegnato nell'operativit\ue0, \ue8 stato possibile riconoscere lo sguardo con il quale si osservano gli altri e le altre che vengono da lontano e comprendere che le forme delle difficolt\ue0, che le famiglie, le donne e gli uomini che vengono da lontano presentano, riflettono inevitabilmente il modo di vederli, i sistemi di analisi e di attribuzione di senso e di significato delle istituzioni educative, sanitarie del paese di migrazione e dei loro professionisti. Ogni operatore, normalmente, pensa di essere preparato ad accogliere l'altro e forse per questo lo shock culturale ha sempre la caratteristica dell'imprevisto e di qualcosa che assomiglia ad uno scontro. Ma il disorientamento pu\uf2 essere um terreno fertile, se promove la necessit\ue0 e il Desiderio di fermarsi, tornare ad ascoltare, tornare a guardare i propri passi, riprendere i propri confini e le proprie interrogazioni