de Sitter symmetry of Neveu-Schwarz spinors

We study the relations between Dirac fields living on the 2-dimensional Lorentzian cylinder and the ones living on the double-covering of the 2-dimensional de Sitter manifold, here identified as a certain coset space of the group $SL(2,R)$. We show that there is an extended notion of de Sitter covariance only for Dirac fields having the Neveu-Schwarz anti-periodicity and construct the relevant cocycle. Finally, we show that the de Sitter symmetry is naturally inherited by the Neveu-Schwarz massless Dirac field on the cylinder.Comment: 24 page

Can the Chaplygin gas be a plausible model for dark energy?

In this note two cosmological models representing the flat Friedmann Universe filled with a Chaplygin fluid, with or without dust, are analyzed in terms of the recently proposed "statefinder" parameters. Trajectories of both models in the parameter plane are shown to be significantly different w.r.t. "quiessence" and "tracker" models. The generalized Chaplygin gas model with an equation of state of the form $p = -A/\rho^{\alpha}$ is also analyzed in terms of the statefinder parameters.Comment: 6 pages, 2 figure

Surgical Treatment of Extravasation Injuries

The authors present their experience of treating anti-cancer drug extravasation by means of a composite surgical technique that consists of infiltration with physiological solution and hyaluronidase and subsequent manual aspiration of solutes alternated with profuse irrigation of the infiltrated area. In the immediate post-op we carry out a medical therapy that consists of calciparine and topic antibiotic and/or steroid creams. Since the year 2000 this technique has been used on 25 patients. We have had neither complications nor scars. Copyright 2005 Wiley-Liss, IncSurgical treatment of extravasation injuries. Napoli P, Corradino B, Badalamenti G, Tripoli M, Vieni S, Furfaro MF, Cordova A, Moschella F. Source Chirurgia Plastica e Ricostruttiva, Dipartimento di Discipline Chirurgiche ed Oncologiche, Università degli Studi di Palermo, Italy. [email protected] Abstract The authors present their experience of treating anti-cancer drug extravasation by means of a composite surgical technique that consists of infiltration with physiological solution and hyaluronidase and subsequent manual aspiration of solutes alternated with profuse irrigation of the infiltrated area. In the immediate post-op we carry out a medical therapy that consists of calciparine and topic antibiotic and/or steroid creams. Since the year 2000 this technique has been used on 25 patients. We have had neither complications nor scars

Spherical `Top-Hat' Collapse in general Chaplygin gas dominated universes

We expand previous works on the spherical `top-hat' collapse (SC-TH) framework in generalized Chaplygin gas (gCg) dominated universes. Here we allow the collapse in all energetic components within the system. We analyze the non-linear stages of collapse for various choices of parameter \alpha of the gCg model introducing an exact formulation for the so-called effective sound speed, $c_{eff}^2$. We show that, within the SC-TH framework, the growth of the structure becomes faster with increasing values of \alpha.Comment: 17 pages, 5 figures, submitted to Phys. Rev. D. Changes: A new table (Table II) and a new paragraph (at the end of section III.B), were added; Fig. 5 was redrawn and split in two sub-plots, 5a and 5b. We have added a few comments, and a reference, in the introduction; Slight text modifications and typos correctio

Porcine model for deep superior epigastric artery perforator flap harvesting: Anatomy and technique

BACKGROUND Microsurgical training on rats before starting with clinical practice is a well-established routine. Animal model training is less widespread for perforator flaps, although these flaps represent a technical challenge. Unlike other flaps, they require specific technical skills that need to be adequately trained on a living model 1 : a cadaver is not enough because no bleeding, vessel damage, or vasospasm can be simulated. 2 The purpose of this study was to assess the suitability of the porcine abdomen as a training model for the deep inferior epigastric artery perforator (DIEAP) flap, commonly used in human breast reconstruction. METHODS A female swine (Sus scrofa domesticus, ssp; weight 25kg) was used. The procedure was performed with the pig under general anesthesia and in the supine position. A deep superior epigastric artery perforator (DSEAP) flap was harvested on the left side of the abdomen, including the 3 cranial nipples and stopping in the midline to spare the contralateral flap for another dissection (as in bilateral breast reconstructions in humans; Fig. 1). All steps of a DIEAP harvest were simulated: superficial vein harvest, suprafascial perforator dissection, intramuscular perforator harvest with preservation of the nerves, and flap isolation. Observation of capillary refill was used to confirm flap viability at the end of the dissection. The procedure was recorded by means of a GoPro camera and simultaneously with a head mounted (4 7 magnification) Loupecam system. Photographs were taken using 2 cameras during surgery at relevant time points. RESULTS At the end of the dissection, the flap was viable. The subcutaneous adipose tissue of the pig is less represented than in human and pigs have an additional muscular layer, the panniculus carnosus, which is the analogue of the human Scarpa's fascia. The rectus fascia is thinner. The perforators are lined in 2 rows: 1 lateral and 1 medial, as in the DIEAP, and the intercostal nerves cross the vessels, as happens in humans. The porcine rectus abdominis muscle is thinner than the human one, but vessels' branching faithfully reproduces the human model. 1 We identified 5 perforating vessels of more than 1mm in diameter (2 lateral and 3 medial). We isolated a lateral perforator first and a medial one last: the latter was eventually used to nourish the flap (Fig. 2). CONCLUSIONS The DSEAP flap allows one to closely reproduce all the steps of DIEAP flap harvesting and also to carry out the intramuscular dissection of 2 perforators for each side (up to 4 for each animal), confirming the adequacy of this pig model for microsurgical training. The deep superior epigastric artery is dominant in pigs. 3 Despite this anatomical difference, the DSEAP allows one to reproduce the main steps of DIEAP flap harvesting, providing an excellent training model. Moreover, the presence of double perforating rows allows simulating the dissection twice on each side

Porcine model for gluteal artery perforator flap: Anatomy and technique

Although flap anatomy is well studied on cadavers and microsurgical techniques are well practiced on rats, still there are few training models for learning the techniques of perforator flap harvesting. The cadaver has no bloodstream, so accuracy of dissection cannot be evaluated and flap viability cannot be verified. Training on humans carries a high risk of flap damage. A living model for perforator flap harvest is needed to learn the technique before starting with its clinical application

Different renal phenotypes in related adult males with Fabry disease with the same classic genotype

BACKGROUND: Fabry disease related patients with classical mutation usually exhibit similar severe phenotype especially concerning renal manifestation. METHODS: A dry blood spot screening (DBS) and the DNA analysis has been performed in a 48-year-old man (Patient 1) because of paresthesia. RESULTS: The DBS revealed absent leukocyte \u3b1-Gal A enzyme activity while DNA analysis identified the I354K mutation. Serum creatinine and e-GFR were in normal range and also albuminuria and proteinuria were absent. The brain MRI showed ischemic lesions and a diffuse focus of gliosis in the white matter, while the echocardiogram showed a left ventricular hypertrophy. The renal biopsy performed in the case index showed a massive deposition of zebra bodies. By a familiar investigation, it was recognized that his brother (Patient 2) died 2 years before from sudden death syndrome at the age of 49. He had suffered sporadic and undiagnosed pain at the extremities, a prior cataract, bilateral neurosensorial hearing loss and left ventricular hypertrophy on Echocardiogram. His previous laboratory examinations revealed a normal serum creatinine and the absence of proteinuria. Pedigree analysis of the brothers revealed a high disease burden among family members, with an affected cousin (Patient 3) who progressed early to end-stage renal disease (ESRD) that required renal transplantation. CONCLUSIONS: Here we describe the clinical history of three adult male members of the same family with the same genotype who manifested different presentation and progression of the disease, particularly concerning the renal involvement

On the Stability of the Einstein Static Universe

We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c_{s}^2>1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilise an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed.Comment: some additional comments and references; version to appear in Class. Quant. Gra

Nonlinear evolution of dark matter and dark energy in the Chaplygin-gas cosmology

The hypothesis that dark matter and dark energy are unified through the Chaplygin gas is reexamined. Using generalizations of the spherical model which incorporate effects of the acoustic horizon we show that an initially perturbative Chaplygin gas evolves into a mixed system containing cold dark matter-like gravitational condensate.Comment: 11 pages, 3 figures, substantial revision, title changed, content changed, added references, to appear in JCA

In the eye of the storm : the Italian economy and the eurozone crisis

The eurozone crisis had a more significant and longer-lasting impact on Italy than on virtually any other member state, with the effects still visible a decade after. The extent of the shock was surprising in view of progress Italy had apparently made in the 1990s in terms of enhancing its capacity to meet the demands of European Monetary Union. The explanation for this traumatic economic experience lies in Italy’s deep, long-term, structural tensions which were placed under severe pressure during the 1990s and which were cracked open by the 2011 sovereign debt crisis. These have had long-standing economic effects as well as political ramifications in terms of a significant change in the Italy–EU relationship